extract material properties: Topics by Science.gov

Sample records for extract material properties

Are extracted materials truly representative of original samples? Impact of C18 extraction on CDOM optical and chemical properties

NASA Astrophysics Data System (ADS)

Andrew, Andrea; Del Vecchio, Rossana; Zhang, Yi; Subramaniam, Ajit; Blough, Neil

2016-02-01

Some properties of dissolved organic matter (DOM) and chromophoric dissolved organic matter (CDOM) can be easily measured directly on whole waters, while others require sample concentration and removal of natural salts. To increase CDOM content and eliminate salts, solid phase extraction is often employed. Biases following extraction and elution are inevitable, thus raising the question of how truly representative the extracted material is of the original. In this context, we investigated the wavelength dependence of extraction efficiency for C18 cartridges with respect to CDOM optical properties using samples obtained from the Middle Atlantic Bight (MAB) and the Equatorial Atlantic Ocean (EAO). Further, we compared the optical changes of C18 extracts and the corresponding whole water following chemical reduction with sodium borohydride (NaBH4). C18 cartridges preferentially extracted long-wavelength absorbing/emitting material for samples impacted by riverine input. Extraction efficiency overall decreased with offshore distance away from riverine input. Spectral slopes of C18-OM samples were also almost always lower than those of their corresponding CDOM samples supporting the preferential extraction of higher molecular weight absorbing material. The wavelength dependence of the optical properties (absorption, fluorescence emission and quantum yield) of the original water samples and their corresponding extracted material were very similar. C18 extracts and corresponding water samples further exhibited comparable optical changes following NaBH4 reduction, thus suggesting a similarity in nature (structure) of the optically active extracted material, independent of geographical locale. Altogether, these data suggested a strong similarity between C18 extracts and corresponding whole waters, thus indicating that extracts are representative of the CDOM content of original waters.
Are Extracted Materials Truly Representative of Original Samples? Impact of C18 Extraction on CDOM Optical and Chemical Properties

PubMed Central

Andrew, Andrea A.; Del Vecchio, Rossana; Zhang, Yi; Subramaniam, Ajit; Blough, Neil V.

2016-01-01

Some properties of dissolved organic matter (DOM) and chromophoric dissolved organic matter (CDOM) can be easily measured directly on whole waters, while others require sample concentration and removal of natural salts. To increase CDOM content and eliminate salts, solid phase extraction (SPE) is often employed. Biases following extraction and elution are inevitable, thus raising the question of how truly representative the extracted material is of the original. In this context, we investigated the wavelength dependence of extraction efficiency for C18 cartridges with respect to CDOM optical properties using samples obtained from the Middle Atlantic Bight (MAB) and the Equatorial Atlantic Ocean (EAO). Further, we compared the optical changes of C18 extracts and the corresponding whole water following chemical reduction with sodium borohydride (NaBH4). C18 cartridges preferentially extracted long-wavelength absorbing/emitting material for samples impacted by riverine input. Extraction efficiency overall decreased with offshore distance away from riverine input. Spectral slopes of C18-OM samples were also almost always lower than those of their corresponding CDOM samples supporting the preferential extraction of higher molecular weight absorbing material. The wavelength dependence of the optical properties (absorption, fluorescence emission, and quantum yield) of the original water samples and their corresponding extracted material were very similar. C18 extracts and corresponding water samples further exhibited comparable optical changes following NaBH4 reduction, thus suggesting a similarity in nature (structure) of the optically active extracted material, independent of geographical locale. Altogether, these data suggested a strong similarity between C18 extracts and corresponding whole waters, thus indicating that extracts are representative of the CDOM content of original waters. PMID:26904536
Are Extracted Materials Truly Representative of Original Samples? Impact of C18 Extraction on CDOM Optical and Chemical Properties.

PubMed

Andrew, Andrea A; Del Vecchio, Rossana; Zhang, Yi; Subramaniam, Ajit; Blough, Neil V

2016-01-01

Some properties of dissolved organic matter (DOM) and chromophoric dissolved organic matter (CDOM) can be easily measured directly on whole waters, while others require sample concentration and removal of natural salts. To increase CDOM content and eliminate salts, solid phase extraction (SPE) is often employed. Biases following extraction and elution are inevitable, thus raising the question of how truly representative the extracted material is of the original. In this context, we investigated the wavelength dependence of extraction efficiency for C18 cartridges with respect to CDOM optical properties using samples obtained from the Middle Atlantic Bight (MAB) and the Equatorial Atlantic Ocean (EAO). Further, we compared the optical changes of C18 extracts and the corresponding whole water following chemical reduction with sodium borohydride (NaBH4). C18 cartridges preferentially extracted long-wavelength absorbing/emitting material for samples impacted by riverine input. Extraction efficiency overall decreased with offshore distance away from riverine input. Spectral slopes of C18-OM samples were also almost always lower than those of their corresponding CDOM samples supporting the preferential extraction of higher molecular weight absorbing material. The wavelength dependence of the optical properties (absorption, fluorescence emission, and quantum yield) of the original water samples and their corresponding extracted material were very similar. C18 extracts and corresponding water samples further exhibited comparable optical changes following NaBH4 reduction, thus suggesting a similarity in nature (structure) of the optically active extracted material, independent of geographical locale. Altogether, these data suggested a strong similarity between C18 extracts and corresponding whole waters, thus indicating that extracts are representative of the CDOM content of original waters.
Understanding the bond-energy, hardness, and adhesive force from the phase diagram via the electron work function

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lu, Hao; Huang, Xiaochen; Li, Dongyang, E-mail: dongyang.li@ualberta.ca

2014-11-07

Properties of metallic materials are intrinsically determined by their electron behavior. However, relevant theoretical treatment involving quantum mechanics is complicated and difficult to be applied in materials design. Electron work function (EWF) has been demonstrated to be a simple but fundamental parameter which well correlates properties of materials with their electron behavior and could thus be used to predict material properties from the aspect of electron activities in a relatively easy manner. In this article, we propose a method to extract the electron work functions of binary solid solutions or alloys from their phase diagrams and use this simple approachmore » to predict their mechanical strength and surface properties, such as adhesion. Two alloys, Fe-Ni and Cu-Zn, are used as samples for the study. EWFs extracted from phase diagrams show same trends as experimentally observed ones, based on which hardness and surface adhesive force of the alloys are predicted. This new methodology provides an alternative approach to predict material properties based on the work function, which is extractable from the phase diagram. This work may also help maximize the power of phase diagram for materials design and development.« less
[Comparison of the antioxidant properties of selected parts of raspberry (Rubus idaeus) and blackberry (Rubus fruticosus)

PubMed

Zielonka-Brzezicka, Joanna; Nowak, Anna; Zielińska, Magdalena; Klimowicz, Adam

Antioxidants contained in plant raw materials prevent oxidative stress, and reduce the degenerative effects of free radical reactions and damage caused by UV radiation. Antioxidant activity is exhibited, for example, in raspberry (Rubus idaeus), and blackberry (Rubus fruticosus), which have a high content of tannins, flavonoids, phenolic acids, vitamins and minerals. The raw plant material consisted of fresh and dried leaves and fruits of raspberries and blackberries harvested in 2014. This material was extracted using a Soxhlet apparatus and by an ultrasound-assisted technique. To evaluate antioxidant activity DPPH and FRAP methods were used in the first year and DPPH and ABTS methods in the second year of the study. The highest antioxidant activity, evaluated by the DPPH method in 2015, was demonstrated by both raspberry and blackberry fresh leaf extracts, whereas the highest reductive ability, assessed by FRAP, was demonstrated in fresh and dried blackberry leaves. In the next year of the study (2016), the activity of samples evaluated using the DPPH method did not differ significantly, with the exception of fresh raspberry leaf. In this year, the highest antioxidant properties, assessed using the ABTS method, were shown by extracts made of fresh blackberry leaves and fruits, and dried blackberry leaves. All the studied material, both ethanolic leaves and fruit extracts of raspberry and blackberry, reduced free radicals, which was examined using three methods of evaluation of the antioxidative properties (DPPH, FRAP and ABTS). The storage of ethanolic extracts at ambient temperature had no significant impact on the activity reduction of the evaluated plant material. The antioxidant activity of most examined extracts remained consistently high, which may be reflected in the use of the studied materials as sources of antioxidants in the cosmetics and pharmaceuticals industries.
Synthesis of Two-Dimensional Materials by Selective Extraction

DOE PAGES

Naguib, Michael; Gogotsi, Yury

2014-12-09

Two-dimensional (2D) materials have attracted much attention in the past decade. They offer high specific surface area, as well as electronic structure and properties that differ from their bulk counterparts due to the low dimensionality. Graphene is the best known and the most studied 2D material, but metal oxides and hydroxides (including clays), dichalcogenides, boron nitride (BN), and other materials that are one or several atoms thick are receiving increasing attention. They may deliver a combination of properties that cannot be provided by other materials. The most common synthesis approach in general is by reacting different elements or compounds tomore » form a new compound. However, this approach does not necessarily work well for low-dimensional structures, since it favors formation of energetically preferred 3D (bulk) solids. Many 2D materials are produced by exfoliation of van der Waals solids, such as graphite or MoS2, breaking large particles into 2D layers. However, these approaches are not universal; for example, 2D transition metal carbides cannot be produced by any of them. An alternative but less studied way of material synthesis is the selective extraction process, which is based on the difference in reactivity and stability between the different components (elements or structural units) of the original material. It can be achieved using thermal, chemical, or electrochemical processes. Many 2D materials have been synthesized using selective extraction, such as graphene from SiC, transition metal oxides (TMO) from layered 3D salts, and transition metal carbides or carbonitrides (MXenes) from MAX phases. Selective extraction synthesis is critically important when the bonds between the building blocks of the material are too strong (e.g., in carbides) to be broken mechanically in order to form nanostructures. Unlike extractive metallurgy, where the extracted metal is the goal of the process, selective extraction of one or more elements from the precursor materials releases 2D structures. In this Account, in addition to graphene and TMO, we focused on MXenes as an example for the use of selective extraction synthesis to produce novel 2D materials. About 10 new carbides and carbonitrides of transition metals have been produced by this method in the past 3 years. They offer an unusual combination of metallic conductivity and hydrophilicity and show very attractive electrochemical properties. We hope that this Account will encourage researchers to extend the use of selective extraction to other layered material systems that in turn will result in expanding the world of nanomaterials in general and 2D materials in particular, generating new materials that cannot be produced by other means.« less
Synthesis of two-dimensional materials by selective extraction.

PubMed

Naguib, Michael; Gogotsi, Yury

2015-01-20

CONSPECTUS: Two-dimensional (2D) materials have attracted much attention in the past decade. They offer high specific surface area, as well as electronic structure and properties that differ from their bulk counterparts due to the low dimensionality. Graphene is the best known and the most studied 2D material, but metal oxides and hydroxides (including clays), dichalcogenides, boron nitride (BN), and other materials that are one or several atoms thick are receiving increasing attention. They may deliver a combination of properties that cannot be provided by other materials. The most common synthesis approach in general is by reacting different elements or compounds to form a new compound. However, this approach does not necessarily work well for low-dimensional structures, since it favors formation of energetically preferred 3D (bulk) solids. Many 2D materials are produced by exfoliation of van der Waals solids, such as graphite or MoS2, breaking large particles into 2D layers. However, these approaches are not universal; for example, 2D transition metal carbides cannot be produced by any of them. An alternative but less studied way of material synthesis is the selective extraction process, which is based on the difference in reactivity and stability between the different components (elements or structural units) of the original material. It can be achieved using thermal, chemical, or electrochemical processes. Many 2D materials have been synthesized using selective extraction, such as graphene from SiC, transition metal oxides (TMO) from layered 3D salts, and transition metal carbides or carbonitrides (MXenes) from MAX phases. Selective extraction synthesis is critically important when the bonds between the building blocks of the material are too strong (e.g., in carbides) to be broken mechanically in order to form nanostructures. Unlike extractive metallurgy, where the extracted metal is the goal of the process, selective extraction of one or more elements from the precursor materials releases 2D structures. In this Account, in addition to graphene and TMO, we focused on MXenes as an example for the use of selective extraction synthesis to produce novel 2D materials. About 10 new carbides and carbonitrides of transition metals have been produced by this method in the past 3 years. They offer an unusual combination of metallic conductivity and hydrophilicity and show very attractive electrochemical properties. We hope that this Account will encourage researchers to extend the use of selective extraction to other layered material systems that in turn will result in expanding the world of nanomaterials in general and 2D materials in particular, generating new materials that cannot be produced by other means.
Synthesis of Two-Dimensional Materials by Selective Extraction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Naguib, Michael; Gogotsi, Yury

Two-dimensional (2D) materials have attracted much attention in the past decade. They offer high specific surface area, as well as electronic structure and properties that differ from their bulk counterparts due to the low dimensionality. Graphene is the best known and the most studied 2D material, but metal oxides and hydroxides (including clays), dichalcogenides, boron nitride (BN), and other materials that are one or several atoms thick are receiving increasing attention. They may deliver a combination of properties that cannot be provided by other materials. The most common synthesis approach in general is by reacting different elements or compounds tomore » form a new compound. However, this approach does not necessarily work well for low-dimensional structures, since it favors formation of energetically preferred 3D (bulk) solids. Many 2D materials are produced by exfoliation of van der Waals solids, such as graphite or MoS2, breaking large particles into 2D layers. However, these approaches are not universal; for example, 2D transition metal carbides cannot be produced by any of them. An alternative but less studied way of material synthesis is the selective extraction process, which is based on the difference in reactivity and stability between the different components (elements or structural units) of the original material. It can be achieved using thermal, chemical, or electrochemical processes. Many 2D materials have been synthesized using selective extraction, such as graphene from SiC, transition metal oxides (TMO) from layered 3D salts, and transition metal carbides or carbonitrides (MXenes) from MAX phases. Selective extraction synthesis is critically important when the bonds between the building blocks of the material are too strong (e.g., in carbides) to be broken mechanically in order to form nanostructures. Unlike extractive metallurgy, where the extracted metal is the goal of the process, selective extraction of one or more elements from the precursor materials releases 2D structures. In this Account, in addition to graphene and TMO, we focused on MXenes as an example for the use of selective extraction synthesis to produce novel 2D materials. About 10 new carbides and carbonitrides of transition metals have been produced by this method in the past 3 years. They offer an unusual combination of metallic conductivity and hydrophilicity and show very attractive electrochemical properties. We hope that this Account will encourage researchers to extend the use of selective extraction to other layered material systems that in turn will result in expanding the world of nanomaterials in general and 2D materials in particular, generating new materials that cannot be produced by other means.« less
MMKG: An approach to generate metallic materials knowledge graph based on DBpedia and Wikipedia

NASA Astrophysics Data System (ADS)

Zhang, Xiaoming; Liu, Xin; Li, Xin; Pan, Dongyu

2017-02-01

The research and development of metallic materials are playing an important role in today's society, and in the meanwhile lots of metallic materials knowledge is generated and available on the Web (e.g., Wikipedia) for materials experts. However, due to the diversity and complexity of metallic materials knowledge, the knowledge utilization may encounter much inconvenience. The idea of knowledge graph (e.g., DBpedia) provides a good way to organize the knowledge into a comprehensive entity network. Therefore, the motivation of our work is to generate a metallic materials knowledge graph (MMKG) using available knowledge on the Web. In this paper, an approach is proposed to build MMKG based on DBpedia and Wikipedia. First, we use an algorithm based on directly linked sub-graph semantic distance (DLSSD) to preliminarily extract metallic materials entities from DBpedia according to some predefined seed entities; then based on the results of the preliminary extraction, we use an algorithm, which considers both semantic distance and string similarity (SDSS), to achieve the further extraction. Second, due to the absence of materials properties in DBpedia, we use an ontology-based method to extract properties knowledge from the HTML tables of corresponding Wikipedia Web pages for enriching MMKG. Materials ontology is used to locate materials properties tables as well as to identify the structure of the tables. The proposed approach is evaluated by precision, recall, F1 and time performance, and meanwhile the appropriate thresholds for the algorithms in our approach are determined through experiments. The experimental results show that our approach returns expected performance. A tool prototype is also designed to facilitate the process of building the MMKG as well as to demonstrate the effectiveness of our approach.
Application for managing model-based material properties for simulation-based engineering

DOEpatents

Hoffman, Edward L [Alameda, CA

2009-03-03

An application for generating a property set associated with a constitutive model of a material includes a first program module adapted to receive test data associated with the material and to extract loading conditions from the test data. A material model driver is adapted to receive the loading conditions and a property set and operable in response to the loading conditions and the property set to generate a model response for the material. A numerical optimization module is adapted to receive the test data and the model response and operable in response to the test data and the model response to generate the property set.
Complex rheological properties of a water-soluble extract from the fronds of the black tree fern, Cyathea medullaris.

PubMed

Goh, Kelvin K T; Matia-Merino, Lara; Hall, Christopher E; Moughan, Paul J; Singh, Harjinder

2007-11-01

A water-soluble extract was obtained from the fronds of a New Zealand native black tree fern (Cyathea medullaris or Mamaku in Māori). The extract exhibited complex rheological behavior. Newtonian, shear-thinning, shear-thickening, thixotropic, antithixotropic, and viscoelastic behaviors were observed depending on polymer concentration, shear rate, and shear history. The extract also displayed rod-climbing and self-siphoning properties typical of viscoelastic fluids. Such complex rheological properties have been reported in synthetic or chemically modified polymers but are less frequent in unmodified biopolymers. Although Mamaku extract obtained from the pith of the fern has been traditionally used by the Māori in New Zealand for treating wounds and diarrhea among other ailments, this material has never been characterized before. This study reports on the chemical composition of the extract and on its viscoelastic properties through rotational and oscillatory rheological measurements. Explanations of the mechanism behind the rheological properties were based on transient network models for associating polymers.
Properties of Residue from Olive Oil Extraction as a Raw Material for Sustainable Construction Materials. Part I: Physical Properties

PubMed Central

Díaz-García, Almudena; Martínez-García, Carmen; Cotes-Palomino, Teresa

2017-01-01

Action on climate, the environment, and the efficient use of raw materials and resources are important challenges facing our society. Against this backdrop, the construction industry must adapt to new trends and environmentally sustainable construction systems, thus requiring lines of research aimed at keeping energy consumption in new buildings as low as possible. One of the main goals of this research is to efficiently contribute to reducing the amount of residue from olive oil extraction using a two-phase method. This can be achieved by producing alternative structural materials to be used in the construction industry by means of a circular economy. The technical feasibility of adding said residue to ceramic paste was proven by analyzing the changes produced in the physical properties of the paste, which were then compared to the properties of the reference materials manufactured with clay without residue. Results obtained show that the heating value of wet pomace can contribute to the thermal needs of the sintering process, contributing 30% of energy in pieces containing 3% of said material. Likewise, adding larger amounts of wet pomace to the clay body causes a significant decrease in bulk density values. PMID:28772461
Extraction study on uranyl nitrate for energy applications

NASA Astrophysics Data System (ADS)

Giri, R.; Nath, G.

2017-07-01

Due to the ever-growing demand of energy nuclear reactor materials and the nuclear energy are now considered to be the most critical materials and source of energy for future era. Deposition of nuclear wastes in different industry, nuclear power sector are very much toxic in open environment which are hazardous to living being. There are different methods for extraction and reprocessing of these materials which are cost effective and tedious process. Ultrasonic assisted solvent extraction process is a most efficient and economical way for extraction of such type materials. The presence of third phase in mixing of extractants-diluent pair with aqueous phase imposes the problems in extraction of nuclear reactor materials. The appropriate solvent mixture in proper concentration is an important step in the solvent extraction process. Study of thermo-physical properties helps in selecting an optimum blend for extraction process. In the present work, the extraction of uranium with the binary mixture of Methyl Ethyl Ketone (MEK) and Kerosene was investigated and discussed with the variation of ultrasonic frequency for different temperatures. The result shows that the low frequency and low temperature is suitable environment for extraction. The extraction of uranium by this method is found to be a better result for extraction study in laboratory scale as well as industrial sector.
Data analytics and parallel-coordinate materials property charts

NASA Astrophysics Data System (ADS)

Rickman, Jeffrey M.

2018-01-01

It is often advantageous to display material properties relationships in the form of charts that highlight important correlations and thereby enhance our understanding of materials behavior and facilitate materials selection. Unfortunately, in many cases, these correlations are highly multidimensional in nature, and one typically employs low-dimensional cross-sections of the property space to convey some aspects of these relationships. To overcome some of these difficulties, in this work we employ methods of data analytics in conjunction with a visualization strategy, known as parallel coordinates, to represent better multidimensional materials data and to extract useful relationships among properties. We illustrate the utility of this approach by the construction and systematic analysis of multidimensional materials properties charts for metallic and ceramic systems. These charts simplify the description of high-dimensional geometry, enable dimensional reduction and the identification of significant property correlations and underline distinctions among different materials classes.
Nopal Cactus (Opuntia Ficus-Indica) as a Holographic Material

PubMed Central

Olivares-Pérez, Arturo; Toxqui-López, Santa; Padilla-Velasco, Ana L.

2012-01-01

The nopal cactus (Opuntia ficus-indica) releases a substance through its mucilage, which comes from the degradation of pectic substances and chlorophyll. Combined in a polyvinyl alcohol matrix, this substance can be used as a recording medium. The resulting extract material has excellent photosensitizer properties, is easy to handle, has a low cost, and low toxicity. This material has the property of self-developing, and it can be used in holographic applications. The polyvinyl alcohol and extract from the nopal cactus was deposited by a gravity technique on a glass substrate, which dried to form a photosensitive emulsion. We show experimental results on a holographic grating using this material, written by a He-Cd laser (442 nm). We obtained diffraction gratings by transmission with a diffraction efficiency of approximately 32.3% to first order.
Antimicrobial, Optical and Mechanical Properties of Chitosan-Starch Films with Natural Extracts.

PubMed

Lozano-Navarro, Jessica I; Díaz-Zavala, Nancy P; Velasco-Santos, Carlos; Martínez-Hernández, Ana L; Tijerina-Ramos, Beatriz I; García-Hernández, Margarita; Rivera-Armenta, José L; Páramo-García, Ulises; Reyes-de la Torre, Adriana I

2017-05-05

Natural extracts possess several kinds of antioxidants (anthocyanins, betalains, thymol, carvacrol, and resveratrol) that have also demonstrated antimicrobial properties. In order to study these properties, extracts from cranberry, blueberry, beetroot, pomegranate, oregano, pitaya, and resveratrol (from grapes) were obtained. Growth inhibition tests of mesophilic aerobes, coliforms, and fungi were conducted in films prepared from the extracts in accordance with Mexican Official Norms (NOM). Optical properties such as transparency and opacity, mechanical properties, and pH were also analyzed in these materials. The films with beetroot, cranberry, and blueberry extracts demonstrated the best antimicrobial activity against various bacteria and fungi in comparison with unmodified chitosan-starch film. This study shows that the addition of antioxidants improved the antimicrobial performance of these films. It was also found that antimicrobial properties are inherent to the films. These polymers combined with the extracts effectively inhibit or reduce microorganism growth from human and environmental contact; therefore, previous sterilization could be unnecessary in comparison with traditional plastics. The presence of extracts decreased transmittance percentages at 280 and 400 nm, as well as the transparency values, while increasing their opacity values, providing better UV-VIS light barrier properties. Despite diminished glass transition temperatures ( T g), the values obtained are still adequate for food packaging applications.
Antimicrobial, Optical and Mechanical Properties of Chitosan–Starch Films with Natural Extracts

PubMed Central

Lozano-Navarro, Jessica I.; Díaz-Zavala, Nancy P.; Velasco-Santos, Carlos; Martínez-Hernández, Ana L.; Tijerina-Ramos, Beatriz I.; García-Hernández, Margarita; Rivera-Armenta, José L.; Páramo-García, Ulises; Reyes-de la Torre, Adriana I.

2017-01-01

Natural extracts possess several kinds of antioxidants (anthocyanins, betalains, thymol, carvacrol, and resveratrol) that have also demonstrated antimicrobial properties. In order to study these properties, extracts from cranberry, blueberry, beetroot, pomegranate, oregano, pitaya, and resveratrol (from grapes) were obtained. Growth inhibition tests of mesophilic aerobes, coliforms, and fungi were conducted in films prepared from the extracts in accordance with Mexican Official Norms (NOM). Optical properties such as transparency and opacity, mechanical properties, and pH were also analyzed in these materials. The films with beetroot, cranberry, and blueberry extracts demonstrated the best antimicrobial activity against various bacteria and fungi in comparison with unmodified chitosan–starch film. This study shows that the addition of antioxidants improved the antimicrobial performance of these films. It was also found that antimicrobial properties are inherent to the films. These polymers combined with the extracts effectively inhibit or reduce microorganism growth from human and environmental contact; therefore, previous sterilization could be unnecessary in comparison with traditional plastics. The presence of extracts decreased transmittance percentages at 280 and 400 nm, as well as the transparency values, while increasing their opacity values, providing better UV–VIS light barrier properties. Despite diminished glass transition temperatures (Tg), the values obtained are still adequate for food packaging applications. PMID:28475151
Measurement of elastic and thermal properties of composite materials using digital speckle pattern interferometry

NASA Astrophysics Data System (ADS)

Kumar, Manoj; Khan, Gufran S.; Shakher, Chandra

2015-08-01

In the present work, application of digital speckle pattern interferometry (DSPI) was applied for the measurement of mechanical/elastic and thermal properties of fibre reinforced plastics (FRP). Digital speckle pattern interferometric technique was used to characterize the material constants (Poisson's ratio and Young's modulus) of the composite material. Poisson ratio based on plate bending and Young's modulus based on plate vibration of material are measured by using DSPI. In addition to this, the coefficient of thermal expansion of composite material is also measured. To study the thermal strain analysis, a single DSPI fringe pattern is used to extract the phase information by using Riesz transform and the monogenic signal. The phase extraction from a single DSPI fringe pattern by using Riesz transform does not require a phase-shifting system or spatial carrier. The elastic and thermal parameters obtained from DSPI are in close agreement with the theoretical predictions available in literature.
Comparative study of the swabbing properties of seven commercially available swab materials for cleaning verification.

PubMed

Corrigan, Damion K; Piletsky, Sergey; McCrossen, Sean

2009-01-01

This article compares the technical performances of several different commercially available swabbing materials for the purpose of cleaning verification. A steel surface was soiled with solutions of acetaminophen, nicotinic acid, diclofenac, and benzamidine and wiped with each swabbing material. The compounds were extracted with water or ethanol (depending on polarity of analyte) and their concentration in extract was quantified spectrophotometrically. The study also investigated swab debris on the wiped surface. The swab performances were compared and the best swab material was identified.
Comparison of the Solubilization Properties of Polysorbate 80 and Isopropanol/Water Solvent Systems for Organic Compounds Extracted from Three Pharmaceutical Packaging Configurations.

PubMed

Zdravkovic, Steven A

2016-10-10

It has been reported that the presence of polysorbate 80 in a pharmaceutical product's formulation may increase the number and/or amount of impurities leached from materials used during its manufacture, storage, and/or administration. However, it is uncertain if/how the solubilization properties of this surfactant compare to non-surfactant solvent systems. The goal of this study is to provide insight into this area of uncertainty by comparing the solubilization properties of polysorbate 80 to those of isopropanol/water solutions while in contact with a plasticized polyvinylchloride parenteral delivery bag, a single-use type manufacturing bag, and a polypropylene bottle. These properties were determined via a binding experiment, in which a set of model compounds was introduced into the solutions, and via an extraction experiment, in which compounds were extracted from the packaging material by the solutions. In both experiments, the amount of each compound present at equilibrium was assayed to determine the extent they were solubilized by the solution from the packaging material. Results from these experiments illustrate differences in the magnitude of solubilization obtained from solutions containing polysorbate 80 as compared to those composed of isopropanol/water. However, it was also demonstrated that their solubilization properties can be linked via a mathematical model. Copyright © 2016 Elsevier B.V. All rights reserved.

Green and Efficient Processing of Cinnamomum cassia Bark by Using Ionic Liquids: Extraction of Essential Oil and Construction of UV-Resistant Composite Films from Residual Biomass.

PubMed

Mehta, Mohit J; Kumar, Arvind

2017-12-14

There is significant interest in the development of a sustainable and integrated process for the extraction of essential oils and separation of biopolymers by using novel and efficient solvent systems. Herein, cassia essential oil enriched in coumarin is extracted from Cinnamomum cassia bark by using a protic ionic liquid (IL), ethylammonium nitrate (EAN), through dissolution and the creation of a biphasic system with the help of diethyl ether. The process has been perfected, in terms of higher biomass dissolution ability and essential oil yield through the addition of aprotic ILs (based on the 1-butyl-3-methylimidazolium (C 4 mim) cation and chloride or acetate anions) to EAN. After extraction of oil, cellulose-rich material and free lignin were regenerated from biomass-IL solutions by using a 1:1 mixture of acetone-water. The purity of the extracted essential oil and biopolymers were ascertained by means of FTIR spectroscopy, NMR spectroscopy, and GC-MS techniques. Because lignin contains UV-blocking chromophores, the oil-free residual lignocellulosic material has been directly utilized to construct UV-light-resistant composite materials in conjunction with the biopolymer chitosan. Composite material thus obtained was processed to form biodegradable films, which were characterized for mechanical and optical properties. The films showed excellent UV-light resistance and mechanical properties, thereby making it a material suitable for packaging and light-sensitive applications. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
Identification of functional groups of Opuntia ficus-indica involved in coagulation process after its active part extraction.

PubMed

Bouaouine, Omar; Bourven, Isabelle; Khalil, Fouad; Baudu, Michel

2018-04-01

Opuntia ficus-indica that belongs to the Cactaceae family and is a member of Opuntia kind has received increasing research interest for wastewater treatment by flocculation. The objectives of this study were (i) to provide more information regarding the active constituents of Opuntia spp. and (ii) to improve the extracting and using conditions of the flocculant molecules for water treatment. A classic approach by jar test experiments was used with raw and extracted material by solubilization and precipitation. The surface properties of solid material were characterized by FTIR, SEM, zeta potential measurement, and surface titration. The splitting based on the solubility of the material with pH and the titration of functional groups completed the method. The optimal pH value for a coagulation-flocculation process using cactus solid material (CSM) was 10.0 and a processing rate of 35 mg L -1 . The alkaline pH of flocculation suggests an adsorption mechanism with bridging effect between particles by water-soluble extracted molecules. To validate this mechanism, an extraction water was carried out at pH = 10 (optimum of flocculation) and the solution was acidified (pH = 7) to allow precipitation of so considered active flocculant molecules. The strong flocculant property of this extract was verified, and titration of this solution showed at least one specific pKa of 9.0 ± 0.6. This pKa corresponds to phenol groups, which could be assigned to lignin and tannin.
Magnetic graphene oxide modified by imidazole-based ionic liquids for the magnetic-based solid-phase extraction of polysaccharides from brown alga.

PubMed

Wang, Xiaoqin; Li, Guizhen; Row, Kyung Ho

2017-08-01

Magnetic graphene oxide was modified by four imidazole-based ionic liquids to synthesize materials for the extraction of polysaccharides by magnetic solid-phase extraction. Fucoidan and laminarin were chosen as the representative polysaccharides owing to their excellent pharmaceutical value and availability. Fourier transform infrared spectroscopy, field-emission scanning electron microscopy, and thermogravimetric analysis were applied to characterize the synthesized materials. Single-factor experiments showed that the extraction efficiency of polysaccharides was affected by the amount of ionic liquids for modification, solid-liquid ratio of brown alga and ethanol, the stirring time of brown alga and ionic liquid-modified magnetic graphene oxide materials, and amount of 1-(3-aminopropyl)imidazole chloride modified magnetic graphene oxide materials added to the brown alga sample solution. The results indicated that 1-(3-aminopropyl)imidazole chloride modified magnetic graphene oxide possessed better extraction ability than graphene oxide, magnetic graphene oxide, and other three ionic-liquid-modified magnetic graphene oxide materials. The highest extraction recoveries of fucoidan and laminarin extracted by 1-(3-aminopropyl)imidazole chloride modified magnetic graphene oxide were 93.3 and 87.2%, respectively. In addition, solid materials could be separated and reused easily owing to their magnetic properties. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Effect of Additional Suji Leaves and Turmeric Extract on Physicochemical Characteristic and Antioxidant Activity of Arenga-Canna Noodle

NASA Astrophysics Data System (ADS)

Miftakhussolikhah; Ariani, D.; Herawati, ERN; Nastiti, A.; Angwar, M.; Pranoto, Y.

2017-12-01

Canna can be used as raw material for noodle but need a substitute material such as arenga starch. Arenga-canna noodle has dark appearance. Addition coloring agents from suji leaves and turmeric extract was done to improve product appearance and its functional characteristics. In this study, noodle was made with five variations of suji leaves and turmeric extract. Physical and chemical properties of noodle were analyzed. The results showed addition suji leaves extract and turmeric extract 0.4 g suji leaf/ml water and 0.06 g turmeric/ml water respectively, produce the best arenga-canna noodle quality. The addition of natural coloring agents increased antioxidant activity.
Comparison of Enzymatic and Ultrasonic Extraction of Albumin from Defatted Pumpkin (Cucurbita pepo) Seed Powder

PubMed Central

Tu, Gia Loi; Bui, Thi Hoang Nga; Tran, Thi Thu Tra; Ton, Nu Minh Nguyet

2015-01-01

Summary In this study, ultrasound- and enzyme-assisted extractions of albumin (water-soluble protein group) from defatted pumpkin (Cucurbita pepo) seed powder were compared. Both advanced extraction techniques strongly increased the albumin yield in comparison with conventional extraction. The extraction rate was two times faster in the ultrasonic extraction than in the enzymatic extraction. However, the maximum albumin yield was 16% higher when using enzymatic extraction. Functional properties of the pumpkin seed albumin concentrates obtained using the enzymatic, ultrasonic and conventional methods were then evaluated. Use of hydrolase for degradation of cell wall of the plant material did not change the functional properties of the albumin concentrate in comparison with the conventional extraction. The ultrasonic extraction enhanced water-holding, oil-holding and emulsifying capacities of the pumpkin seed albumin concentrate, but slightly reduced the foaming capacity, and emulsion and foam stability. PMID:27904383
Comparison of Enzymatic and Ultrasonic Extraction of Albumin from Defatted Pumpkin (Cucurbita pepo) Seed Powder.

PubMed

Tu, Gia Loi; Bui, Thi Hoang Nga; Tran, Thi Thu Tra; Ton, Nu Minh Nguyet; Man Le, Van Viet

2015-12-01

In this study, ultrasound- and enzyme-assisted extractions of albumin (water-soluble protein group) from defatted pumpkin ( Cucurbita pepo ) seed powder were compared. Both advanced extraction techniques strongly increased the albumin yield in comparison with conventional extraction. The extraction rate was two times faster in the ultrasonic extraction than in the enzymatic extraction. However, the maximum albumin yield was 16% higher when using enzymatic extraction. Functional properties of the pumpkin seed albumin concentrates obtained using the enzymatic, ultrasonic and conventional methods were then evaluated. Use of hydrolase for degradation of cell wall of the plant material did not change the functional properties of the albumin concentrate in comparison with the conventional extraction. The ultrasonic extraction enhanced water-holding, oil-holding and emulsifying capacities of the pumpkin seed albumin concentrate, but slightly reduced the foaming capacity, and emulsion and foam stability.
Simulation-based Extraction of Key Material Parameters from Atomic Force Microscopy

NASA Astrophysics Data System (ADS)

Alsafi, Huseen; Peninngton, Gray

Models for the atomic force microscopy (AFM) tip and sample interaction contain numerous material parameters that are often poorly known. This is especially true when dealing with novel material systems or when imaging samples that are exposed to complicated interactions with the local environment. In this work we use Monte Carlo methods to extract sample material parameters from the experimental AFM analysis of a test sample. The parameterized theoretical model that we use is based on the Virtual Environment for Dynamic AFM (VEDA) [1]. The extracted material parameters are then compared with the accepted values for our test sample. Using this procedure, we suggest a method that can be used to successfully determine unknown material properties in novel and complicated material systems. We acknowledge Fisher Endowment Grant support from the Jess and Mildred Fisher College of Science and Mathematics,Towson University.
Spatially resolved quantitative mapping of thermomechanical properties and phase transition temperatures using scanning probe microscopy

DOEpatents

Jesse, Stephen; Kalinin, Sergei V; Nikiforov, Maxim P

2013-07-09

An approach for the thermomechanical characterization of phase transitions in polymeric materials (polyethyleneterephthalate) by band excitation acoustic force microscopy is developed. This methodology allows the independent measurement of resonance frequency, Q factor, and oscillation amplitude of a tip-surface contact area as a function of tip temperature, from which the thermal evolution of tip-surface spring constant and mechanical dissipation can be extracted. A heating protocol maintained a constant tip-surface contact area and constant contact force, thereby allowing for reproducible measurements and quantitative extraction of material properties including temperature dependence of indentation-based elastic and loss moduli.
Ceramic composites: A review of toughening mechanisms and demonstration of micropillar compression for interface property extraction

DOE PAGES

Kabel, Joey; Hosemann, Peter; Zayachuk, Yevhen; ...

2018-01-24

We present that ceramic fiber–matrix composites (CFMCs) are exciting materials for engineering applications in extreme environments. By integrating ceramic fibers within a ceramic matrix, CFMCs allow an intrinsically brittle material to exhibit sufficient structural toughness for use in gas turbines and nuclear reactors. Chemical stability under high temperature and irradiation coupled with high specific strength make these materials unique and increasingly popular in extreme settings. This paper first offers a review of the importance and growing body of research on fiber–matrix interfaces as they relate to composite toughening mechanisms. Second, micropillar compression is explored experimentally as a high-fidelity method formore » extracting interface properties compared with traditional fiber push-out testing. Three significant interface properties that govern composite toughening were extracted. For a 50-nm-pyrolytic carbon interface, the following were observed: a fracture energy release rate of ~2.5 J/m 2, an internal friction coefficient of 0.25 ± 0.04, and a debond shear strength of 266 ± 24 MPa. Lastly, this research supports micromechanical evaluations as a unique bridge between theoretical physics models for microcrack propagation and empirically driven finite element models for bulk CFMCs.« less
Ceramic composites: A review of toughening mechanisms and demonstration of micropillar compression for interface property extraction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kabel, Joey; Hosemann, Peter; Zayachuk, Yevhen

We present that ceramic fiber–matrix composites (CFMCs) are exciting materials for engineering applications in extreme environments. By integrating ceramic fibers within a ceramic matrix, CFMCs allow an intrinsically brittle material to exhibit sufficient structural toughness for use in gas turbines and nuclear reactors. Chemical stability under high temperature and irradiation coupled with high specific strength make these materials unique and increasingly popular in extreme settings. This paper first offers a review of the importance and growing body of research on fiber–matrix interfaces as they relate to composite toughening mechanisms. Second, micropillar compression is explored experimentally as a high-fidelity method formore » extracting interface properties compared with traditional fiber push-out testing. Three significant interface properties that govern composite toughening were extracted. For a 50-nm-pyrolytic carbon interface, the following were observed: a fracture energy release rate of ~2.5 J/m 2, an internal friction coefficient of 0.25 ± 0.04, and a debond shear strength of 266 ± 24 MPa. Lastly, this research supports micromechanical evaluations as a unique bridge between theoretical physics models for microcrack propagation and empirically driven finite element models for bulk CFMCs.« less
Application of ionic liquid for extraction and separation of bioactive compounds from plants.

PubMed

Tang, Baokun; Bi, Wentao; Tian, Minglei; Row, Kyung Ho

2012-09-01

In recent years, ionic liquids (ILs), as green and designer solvents, have accelerated research in analytical chemistry. This review highlights some of the unique properties of ILs and provides an overview of the preparation and application of IL or IL-based materials to extract bioactive compounds in plants. IL or IL-based materials in conjunction with liquid-liquid extraction (LLE), ultrasonic-assisted extraction (UAE), microwave-assisted extraction (MAE), high performance liquid chromatography (HPLC) and solid-phase extraction (SPE) analytical technologies etc., have been applied successfully to the extraction or separation of bioactive compounds from plants. This paper reviews the available data and references to examine the advantages of IL and IL-based materials in these applications. In addition, the main target compounds reviewed in this paper are bioactive compounds with multiple therapeutic effects and pharmacological activities. Based on the importance of the targets, this paper reviews the applications of ILs, IL-based materials or co-working with analytical technologies. The exploitation of new applications of ILs on the extraction of bioactive compounds from plant samples is expected to increase. Copyright © 2012 Elsevier B.V. All rights reserved.
Dehomogenized Elastic Properties of Heterogeneous Layered Materials in AFM Indentation Experiments.

PubMed

Lee, Jia-Jye; Rao, Satish; Kaushik, Gaurav; Azeloglu, Evren U; Costa, Kevin D

2018-06-05

Atomic force microscopy (AFM) is used to study mechanical properties of biological materials at submicron length scales. However, such samples are often structurally heterogeneous even at the local level, with different regions having distinct mechanical properties. Physical or chemical disruption can isolate individual structural elements but may alter the properties being measured. Therefore, to determine the micromechanical properties of intact heterogeneous multilayered samples indented by AFM, we propose the Hybrid Eshelby Decomposition (HED) analysis, which combines a modified homogenization theory and finite element modeling to extract layer-specific elastic moduli of composite structures from single indentations, utilizing knowledge of the component distribution to achieve solution uniqueness. Using finite element model-simulated indentation of layered samples with micron-scale thickness dimensions, biologically relevant elastic properties for incompressible soft tissues, and layer-specific heterogeneity of an order of magnitude or less, HED analysis recovered the prescribed modulus values typically within 10% error. Experimental validation using bilayer spin-coated polydimethylsiloxane samples also yielded self-consistent layer-specific modulus values whether arranged as stiff layer on soft substrate or soft layer on stiff substrate. We further examined a biophysical application by characterizing layer-specific microelastic properties of full-thickness mouse aortic wall tissue, demonstrating that the HED-extracted modulus of the tunica media was more than fivefold stiffer than the intima and not significantly different from direct indentation of exposed media tissue. Our results show that the elastic properties of surface and subsurface layers of microscale synthetic and biological samples can be simultaneously extracted from the composite material response to AFM indentation. HED analysis offers a robust approach to studying regional micromechanics of heterogeneous multilayered samples without destructively separating individual components before testing. Copyright © 2018 Biophysical Society. Published by Elsevier Inc. All rights reserved.
Pressurized solvent extraction of pure food grade starch

USDA-ARS?s Scientific Manuscript database

A commercial pressurized solvent extractor was used to remove lipid and non-lipid material from cornstarch using n-propanol/water and ethanol/water mixtures. Yields and chemical composition of the extract fractions were determined. Cornstarch samples were characterized using pasting properties and...
Green synthesis of silver nanoparticles using Stevia leaves extracts

NASA Astrophysics Data System (ADS)

Laguta, Iryna; Stavinskaya, Oksana; Kazakova, Olga; Fesenko, Tetiana; Brychka, Sergey

2018-02-01

Three extracts of Stevia rebaudiana (Bertoni) were prepared using different types of raw materials: leaves of plants grown ex situ, leaves of plants grown in vitro, callus culture formed on damaged leaves. Composition of the extracts was studied by means of high-performance liquid chromatography and laser desorption/ionization mass spectrometry; total phenol content was estimated using Folin-Ciocalteau method. Flavonoids and hydroxycinnamic acids were found to be the main groups of phenol antioxidants available in the Stevia leaves, with the amount of these compounds in the extract being dependent on the type of raw material. The reducing properties of phenol compounds identified in the extracts were characterized using quantum chemical method; flavonoids and hydroxycinnamic acids were found to have similar redox parameters. Silver nanoparticles (AgNPs) colloids were synthesized using three Stevia extracts; AgNPs size distribution were characterized by means of scanning electron microscopy. All the extracts revealed significant activity in AgNPs synthesis; the nanoparticles of predominantly spherical shape with the average sizes of 16-25 nm were formed. The reducing properties of the extracts were found to correlate with total phenol content; the activity of extracts from the leaves of plants grown ex situ and from callus culture in Ag+ ions reduction was similar to each other and exceeded the activity of extract from the leaves of plants grown in vitro.
Crossmodal association of auditory and visual material properties in infants.

PubMed

Ujiie, Yuta; Yamashita, Wakayo; Fujisaki, Waka; Kanazawa, So; Yamaguchi, Masami K

2018-06-18

The human perceptual system enables us to extract visual properties of an object's material from auditory information. In monkeys, the neural basis underlying such multisensory association develops through experience of exposure to a material; material information could be processed in the posterior inferior temporal cortex, progressively from the high-order visual areas. In humans, however, the development of this neural representation remains poorly understood. Here, we demonstrated for the first time the presence of a mapping of the auditory material property with visual material ("Metal" and "Wood") in the right temporal region in preverbal 4- to 8-month-old infants, using near-infrared spectroscopy (NIRS). Furthermore, we found that infants acquired the audio-visual mapping for a property of the "Metal" material later than for the "Wood" material, since infants form the visual property of "Metal" material after approximately 6 months of age. These findings indicate that multisensory processing of material information induces the activation of brain areas related to sound symbolism. Our findings also indicate that the material's familiarity might facilitate the development of multisensory processing during the first year of life.
Black Phosphorus Quantum Dots for Hole Extraction of Typical Planar Hybrid Perovskite Solar Cells.

PubMed

Chen, Wei; Li, Kaiwen; Wang, Yao; Feng, Xiyuan; Liao, Zhenwu; Su, Qicong; Lin, Xinnan; He, Zhubing

2017-02-02

Black phosphorus, famous as two-dimensional (2D) materials, shows such excellent properties for optoelectronic devices such as tunable direct band gap, extremely high hole mobility (300-1000 cm 2 /(V s)), and so forth. In this Letter, facile processed black phosphorus quantum dots (BPQDs) were successfully applied to enhance hole extraction at the anode side of the typical p-i-n planar hybrid perovskite solar cells, which remarkably improved the performance of devices with photon conversion efficiency ramping up from 14.10 to 16.69%. Moreover, more detailed investigations by c-AFM, SKPM, SEM, hole-only devices, and photon physics measurements discover further the hole extraction effect and work mechanism of the BPQDs, such as nucleation assistance for the growth of large grain size perovskite crystals, fast hole extraction, more efficient hole transfer, and suppression of energy-loss recombination at the anode interface. This work definitely paves the way for discovering more and more 2D materials with high electronic properties to be used in photovoltaics and optoelectronics.
Antimicrobial and Antiradical Activity of Extracts Obtained from Leaves of Five Species of the Genus Bergenia: Identification of Antimicrobial Compounds.

PubMed

Żbikowska, Beata; Franiczek, Roman; Sowa, Alina; Połukord, Grażyna; Krzyżanowska, Barbara; Sroka, Zbigniew

2017-09-01

An important focus of modern medicine is the search for new substances and strategies to combat infectious diseases, which present an increasing threat due to the growth of bacterial resistance to antibiotics. Another problem concerns free radicals, which in excess can cause several serious diseases. An alternative to chemical synthesis of antimicrobial and antiradical compounds is to find active substances in plant raw materials. We prepared extracts from leaves of five species of the genus Bergenia: B. purpurascens, B. cordifolia, B. ligulata, B. crassifolia, and B. ciliata. Antimicrobial and antiradical features of extracts and raw materials were assessed, and the quantities of phenolic compounds were determined. We also evaluated, using high-performance liquid chromatography, the amounts of arbutin and hydroquinone, compounds related to antimicrobial activity of these raw materials. The strongest antiradical properties were shown by leaves of B. crassifolia and B. cordifolia, the lowest by leaves of B. ciliata. The antiradical activity of extracts showed a strong positive correlation with the amount of phenols. All raw materials have significant antimicrobial properties. Among them, the ethyl acetate extracts were the most active. Antimicrobial activity very weakly correlated with the amount of arbutin, but correlated very strongly with the contents of both hydroquinone and phenolic compounds. Additional experiments using artificially prepared mixtures of phenolic compounds and hydroquinone allowed us to conclude that the most active antimicrobial substance is hydroquinone.
A direct comparison of the performance of ground, beaded and silica-grafted MIPs in HPLC and turbulent flow chromatography applications.

PubMed

Fairhurst, Robert E; Chassaing, Christophe; Venn, Richard F; Mayes, Andrew G

2004-12-15

Spherical molecularly imprinted polymers (MIPs) specific to the beta-blocker propranolol have been synthesised using two different approaches and compared to traditional ground monolithic MIPs in HPLC and TFC applications. TFC is a LC technique used for rapid extraction of compounds directly from complex matrices. It can be easily coupled to HPLC and MS for automation of an extraction/analysis procedure. Spherical MIP beads were produced using a suspension polymerisation technique and silica/MIP composite beads by grafting MIP to spherical silica particles using a surface-bound initiator species. Synthesis of both beaded and silica-grafted MIPs was more practical than using the traditional grinding method and yields of spherical particles of the required size between 80 and 100% were routinely achieved. Under HPLC conditions, beaded and ground MIP materials showed a degree of chiral separation for all of the nine beta-blockers tested. The beaded MIP, however, showed much better flow properties and peak shape than the ground material. Silica-grafted MIP showed some separation in five of the drugs and a large improvement in peak shape and analysis times compared with both ground and beaded MIPs. The materials prepared were also used in extraction columns for Turbulent Flow Chromatography (TFC). Although no imprinting effect was observed under typical TFC conditions, beaded polymer materials showed promise for use as TFC extraction columns due to the good flow properties and clean extracts obtained.
Crystal Graph Convolutional Neural Networks for an Accurate and Interpretable Prediction of Material Properties

NASA Astrophysics Data System (ADS)

Xie, Tian; Grossman, Jeffrey C.

2018-04-01

The use of machine learning methods for accelerating the design of crystalline materials usually requires manually constructed feature vectors or complex transformation of atom coordinates to input the crystal structure, which either constrains the model to certain crystal types or makes it difficult to provide chemical insights. Here, we develop a crystal graph convolutional neural networks framework to directly learn material properties from the connection of atoms in the crystal, providing a universal and interpretable representation of crystalline materials. Our method provides a highly accurate prediction of density functional theory calculated properties for eight different properties of crystals with various structure types and compositions after being trained with 1 04 data points. Further, our framework is interpretable because one can extract the contributions from local chemical environments to global properties. Using an example of perovskites, we show how this information can be utilized to discover empirical rules for materials design.
Interstitial and Interlayer Ion Diffusion Geometry Extraction in Graphitic Nanosphere Battery Materials.

PubMed

Gyulassy, Attila; Knoll, Aaron; Lau, Kah Chun; Wang, Bei; Bremer, Peer-Timo; Papka, Michael E; Curtiss, Larry A; Pascucci, Valerio

2016-01-01

Large-scale molecular dynamics (MD) simulations are commonly used for simulating the synthesis and ion diffusion of battery materials. A good battery anode material is determined by its capacity to store ion or other diffusers. However, modeling of ion diffusion dynamics and transport properties at large length and long time scales would be impossible with current MD codes. To analyze the fundamental properties of these materials, therefore, we turn to geometric and topological analysis of their structure. In this paper, we apply a novel technique inspired by discrete Morse theory to the Delaunay triangulation of the simulated geometry of a thermally annealed carbon nanosphere. We utilize our computed structures to drive further geometric analysis to extract the interstitial diffusion structure as a single mesh. Our results provide a new approach to analyze the geometry of the simulated carbon nanosphere, and new insights into the role of carbon defect size and distribution in determining the charge capacity and charge dynamics of these carbon based battery materials.

Interstitial and Interlayer Ion Diffusion Geometry Extraction in Graphitic Nanosphere Battery Materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gyulassy, Attila; Knoll, Aaron; Lau, Kah Chun

2016-01-01

Large-scale molecular dynamics (MD) simulations are commonly used for simulating the synthesis and ion diffusion of battery materials. A good battery anode material is determined by its capacity to store ion or other diffusers. However, modeling of ion diffusion dynamics and transport properties at large length and long time scales would be impossible with current MD codes. To analyze the fundamental properties of these materials, therefore, we turn to geometric and topological analysis of their structure. In this paper, we apply a novel technique inspired by discrete Morse theory to the Delaunay triangulation of the simulated geometry of a thermallymore » annealed carbon nanosphere. We utilize our computed structures to drive further geometric analysis to extract the interstitial diffusion structure as a single mesh. Our results provide a new approach to analyze the geometry of the simulated carbon nanosphere, and new insights into the role of carbon defect size and distribution in determining the charge capacity and charge dynamics of these carbon based battery materials.« less
Interstitial and interlayer ion diffusion geometry extraction in graphitic nanosphere battery materials

DOE PAGES

Gyulassy, Attila; Knoll, Aaron; Lau, Kah Chun; ...

2016-01-31

Large-scale molecular dynamics (MD) simulations are commonly used for simulating the synthesis and ion diffusion of battery materials. A good battery anode material is determined by its capacity to store ion or other diffusers. However, modeling of ion diffusion dynamics and transport properties at large length and long time scales would be impossible with current MD codes. To analyze the fundamental properties of these materials, therefore, we turn to geometric and topological analysis of their structure. In this paper, we apply a novel technique inspired by discrete Morse theory to the Delaunay triangulation of the simulated geometry of a thermallymore » annealed carbon nanosphere. We utilize our computed structures to drive further geometric analysis to extract the interstitial diffusion structure as a single mesh. Lastly, our results provide a new approach to analyze the geometry of the simulated carbon nanosphere, and new insights into the role of carbon defect size and distribution in determining the charge capacity and charge dynamics of these carbon based battery materials.« less
Comparison of physicochemical and functional properties of flour and starch extract in different methods from Africa locust bean (Parkia biglobosa) seeds.

PubMed

Sankhon, Abdoulaye; Amadou, Issoufou; Yao, Wei-Rong; Wang, Heya; Qian, He; Sangare, Moustapha

2014-01-01

African locust bean tree is an important food tree for both human and livestock such as husks and pods. It plays a very vital role in the rural areas. The aim of this study was to evaluate some physicochemical, mineral characteristics and functional properties of flour and starch extract produced from Parkia biglobosa seeds, using different methods. Three different methods were used for starch extraction in other to get the Starch yield (%),composition analysis for; moisture, protein, fat, ash and fiber contents of flour and starch extracts from Parkia biglobosa were determined on dry basis (db), by AACC method, color and PH value measurements was carried out using color flex spectrocolorimeter, and the official method of AOAC respectively. Pasting properties was determined and X-ray powder starch diffraction was used to examine the crystalline property of flour and starch extract. Gelatinization characteristics and in vitro starch digestibility were also determined, test results were processed using one-way analysis of variance (ANOVA). Flour showed higher (P < 0.05), moisture content, fat, carbohydrate, amylopectine, and protein content than starch, while amylose content of this starch was higher (P<0.05). Phosphorus, sodium, magnesium, and potassium minerals content were higher in flour than starch. Pasting properties, gelatinisation, color, pH values, water and oil absorption capacity content of the flour were found to be higher than that of starch. The pasting characteristics showed a decrease of viscosity, final viscosity, set back value, breakdown, and pasting temperature of flour when compared to that of starch. From our results, we speculate that flour from native Parkia biglobosa grown in Guinea under controlled environmental conditions could be considered as an ideal RS material, whereas the extract Parkia starch could be an ideal SDS material. Therefore, these may offer an interesting alternative for food developers, depending on their characteristics and functional properties.
Extracting material response from simple mechanical tests on hardening-softening-hardening viscoplastic solids

NASA Astrophysics Data System (ADS)

Mohan, Nisha

Compliant foams are usually characterized by a wide range of desirable mechanical properties. These properties include viscoelasticity at different temperatures, energy absorption, recoverability under cyclic loading, impact resistance, and thermal, electrical, acoustic and radiation-resistance. Some foams contain nano-sized features and are used in small-scale devices. This implies that the characteristic dimensions of foams span multiple length scales, rendering modeling their mechanical properties difficult. Continuum mechanics-based models capture some salient experimental features like the linear elastic regime, followed by non-linear plateau stress regime. However, they lack mesostructural physical details. This makes them incapable of accurately predicting local peaks in stress and strain distributions, which significantly affect the deformation paths. Atomistic methods are capable of capturing the physical origins of deformation at smaller scales, but suffer from impractical computational intensity. Capturing deformation at the so-called meso-scale, which is capable of describing the phenomenon at a continuum level, but with some physical insights, requires developing new theoretical approaches. A fundamental question that motivates the modeling of foams is `how to extract the intrinsic material response from simple mechanical test data, such as stress vs. strain response?' A 3D model was developed to simulate the mechanical response of foam-type materials. The novelty of this model includes unique features such as the hardening-softening-hardening material response, strain rate-dependence, and plastically compressible solids with plastic non-normality. Suggestive links from atomistic simulations of foams were borrowed to formulate a physically informed hardening material input function. Motivated by a model that qualitatively captured the response of foam-type vertically aligned carbon nanotube (VACNT) pillars under uniaxial compression [2011,"Analysis of Uniaxial Compression of Vertically Aligned Carbon Nanotubes," J. Mech.Phys. Solids, 59, pp. 2227--2237, Erratum 60, 1753-1756 (2012)], the property space exploration was advanced to three types of simple mechanical tests: 1) uniaxial compression, 2) uniaxial tension, and 3) nanoindentation with a conical and a flat-punch tip. The simulations attempt to explain some of the salient features in experimental data, like 1) The initial linear elastic response. 2) One or more nonlinear instabilities, yielding, and hardening. The model-inherent relationships between the material properties and the overall stress-strain behavior were validated against the available experimental data. The material properties include the gradient in stiffness along the height, plastic and elastic compressibility, and hardening. Each of these tests was evaluated in terms of their efficiency in extracting material properties. The uniaxial simulation results proved to be a combination of structural and material influences. Out of all deformation paths, flat-punch indentation proved to be superior since it is the most sensitive in capturing the material properties.
Characterization and imaging of nanostructured materials using tabletop extreme ultraviolet light sources

NASA Astrophysics Data System (ADS)

Karl, Robert; Knobloch, Joshua; Frazer, Travis; Tanksalvala, Michael; Porter, Christina; Bevis, Charles; Chao, Weilun; Abad Mayor, Begoña.; Adams, Daniel; Mancini, Giulia F.; Hernandez-Charpak, Jorge N.; Kapteyn, Henry; Murnane, Margaret

2018-03-01

Using a tabletop coherent extreme ultraviolet source, we extend current nanoscale metrology capabilities with applications spanning from new models of nanoscale transport and materials, to nanoscale device fabrication. We measure the ultrafast dynamics of acoustic waves in materials; by analyzing the material's response, we can extract elastic properties of films as thin as 11nm. We extend this capability to a spatially resolved imaging modality by using coherent diffractive imaging to image the acoustic waves in nanostructures as they propagate. This will allow for spatially resolved characterization of the elastic properties of non-isotropic materials.
Biomaterial based sulphur di oxide gas sensor

NASA Astrophysics Data System (ADS)

Ghosh, P. K.; Sarkar, A.

2013-06-01

Biomaterials are getting importance in the present research field of sensors. In this present paper performance of biomaterial based gas sensor made of gum Arabica and garlic extract had been studied. Extract of garlic clove with multiple medicinal and chemical utility can be proved to be useful in sensing Sulphur di Oxide gas. On exposure to Sulphur di Oxide gas the material under observation suffers some temporary structural change, which can be observed in form of amplified potentiometric change through simple electronic circuitry. Exploiting this very property a potentiometric gas sensor of faster response and recovery time can be designed. In this work sensing property of the said material has been studied through DC conductance, FTIR spectrum etc.
Effective media properties of hyperuniform disordered composite materials

PubMed Central

Sheng, Xin-Qing

2017-01-01

The design challenge of new functional composite materials consisting of multiphase materials has attracted an increasing interest in recent years. In particular, understanding the role of distributions of ordered and disordered particles in a host media is scientifically and technologically important for designing novel materials and devices with superior spectral and angular properties. In this work, the effective medium property of disordered composite materials consisting of hyperuniformly distributed hard particles at different filling fractions is investigated. To accurately extract effective permittivity of a disordered composite material, a full-wave finite element method and the transmission line theory are used. Numerical results show that the theory of hyperuniformity can be conveniently used to design disordered composite materials with good accuracy compared with those materials with randomly dispersed particles. Furthermore, we demonstrate that a Luneburg lens based on the proposed hyperuniform media has superior radiation properties in comparison with previously reported metamaterial designs and it may open up a new avenue in electromagnetic materials-by-design. PMID:28982118
Antioxidant, antinociceptive and anti-inflammatory properties of the aqueous and ethanolic leaf extracts of Andrographis paniculata in some laboratory animals.

PubMed

Adedapo, Adeolu Alex; Adeoye, Bisi Olajumoke; Sofidiya, Margaret Oluwatoyin; Oyagbemi, Ademola Adetokunbo

2015-07-01

The study was designed to evaluate the anti-inflammatory, analgesic and antioxidant properties of Andrographis paniculata leaf extracts in laboratory animals. The dried and powdered leaves of the plant were subjected to phytochemical and proximate analyses. Its mineral content was also determined. Acute toxicity experiments were first performed to determine a safe dose level. The plant material was extracted using water and ethanol as solvents. These extracts were then used to test for the anti-inflammatory, analgesic and antioxidant properties of the plant. The anti-inflammatory tests included carrageenan-induced and histamine-induced paw oedema. The analgesic tests conducted were formalin paw lick test and acetic acid writhing test. The antioxidant activities of the extracts of A. paniculata were determined by 1,1-diphenyl-2-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP), total polyphenol (TP) and 2,2'-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) using ascorbic acid as standard for both DPPH and FRAP, and gallic acid as a standard for both TP and ABTS. The acute toxicity experiment demonstrated that the plant is safe at high doses even at 1600 mg/kg. It was observed that the ethanolic extract of A. paniculata had higher antioxidant activity than the aqueous extract. The experiments using both extracts may suggest that the extracts of A. paniculata leaves possess anti-inflammatory, analgesic and antioxidant properties, although the ethanolic extract seemed to have higher biological properties than the aqueous extract. The results from this study may have justified the plant's folkloric use for medicinal purpose.
Optimized Extraction, Preliminary Characterization, and In Vitro Antioxidant Activity of Polysaccharides from Glycyrrhiza Uralensis Fisch

PubMed Central

Chen, Jie; Li, Wan-chen; Gu, Xin-li

2017-01-01

Background This study performed optimized extraction, preliminary characterization, and in vitro antioxidant activities of polysaccharides from Glycyrrhiza uralensis Fisch. Material/Methods Three parameters (extraction temperature, ratio of water to raw material, and extraction time) were optimized for yields of G. uralensis polysaccharides (GUP) using response surface methodology with Box-Behnken design (BBD). The GUP was purified using DEAE cellulose 32-column chromatography. The main fraction obtained from G. uralensis Fisch was GUP-II, which was composed of rhamnose, arabinose, galactose, and glucose monosaccharide, was screened for antioxidant properties using DP Hand hydroxyl radical scavenging assays. In addition, immunological activity of GUP-II was determined by nitric oxide and lymphocyte proliferation assays. Results Optimization revealed maximum GUP yields with an extraction temperature of 99°C, water: raw material ratio of 15: 1, and extraction duration of 2 h. GUP-II purified from G. uralensis Fisch had good in vitro DPPH and hydroxyl radical scavenging abilities. Immunologically, GUP-II significantly stimulated NO production in RAW 264.7 macrophages, and significantly enhanced LPS-induced lymphocyte proliferation. Conclusions Extraction of GUP from G. uralensis Fisch can be optimized with respect to temperature, extraction period, and ratio of water to material, using response surface methodology. The purified product (GUP-II) possesses excellent antioxidant and immunological activities. PMID:28404983
Wood properties affecting finish service life

Treesearch

R. Sam Williams; Charles Jourdain; George I. Daisey; Robert W. Springate

2000-01-01

Wood is a biological material that has widely different properties depending on species, geographic area where the tree grew, the growth conditions, size of the tree at harvest, sawing, and other manufacturing processes. Some of the more important wood properties as they relate to wood finishing are discussed, e.g., growth rate, density, knots, extractives, juvenile...
Abundance and characteristics of lignin liquid intermediates in wood (Pinus ponderosa Dougl. ex Laws.) during hot water extraction

Treesearch

Manuel Raul Pelaez-Samaniego; Vikram Yadama; Manuel Garcia-Perez; Eini Lowell

2015-01-01

The objective of this research was to investigate the effects of the conditions of hot water extraction (HWE) on abundance, properties, and structure of lignin depolymerization products. HWE of extracted softwood (ponderosa pine) was conducted using temperatures from 140 to 320°C for 90 min. HWE materials were then subjected to a soxhlet...
TOPOTACTIC LITHIUM INSERTION/EXTRACTION PROPERTIES OF A NEW POLYANION MATERIAL LiXCo2(MoO4)3 [0 ≤ X < 3] FOR RECHARGEABLE LITHIUM BATTERIES

NASA Astrophysics Data System (ADS)

Begam, K. M.; Michael, M. S.; Prabaharan, S. R. S.

An open framework type new material LixCo2(MoO4)3 [0 ≤ x < 3] possessing NASICON structure was identified as positive electrode material for use in 3V class lithium batteries. The new material was synthesized in its non-lithiated phase employing a metal/organic precursor method using a soft-combustion approach. We report here on the structural and electrochemical Li+ insertion/extraction properties of the resultant product. XRD revealed a single phase Co2(MoO4)3 powders and the annealed powders were found to contain ultrafine spherical grains. The redox behavior of the new material was demonstrated in lithium containing cells using the conventional wet cell configuration under Li+ aprotic organic electrolyte environment. The material offered a discharge capacity of 110 mAh/g between 3.5V and 1.5V during the first cycle and 50% of the initial capacity was retained at the end of 20th cycle.
Gamma irradiation induced effects of butyl rubber based damping material

NASA Astrophysics Data System (ADS)

Chen, Hong-Bing; Wang, Pu-Cheng; Liu, Bo; Zhang, Feng-Shun; Ao, Yin-Yong

2018-04-01

The effects of gamma irradiation on the butyl rubber based damping material (BRP) at various doses in nitrogen were investigated in this study. The results show that irradiation leads to radiolysis of BRP, with extractives increasing from 14.9 ± 0.8% of control to 37.2 ± 1.2% of sample irradiated at 350 kGy, while the swelling ratio increasing from 294 ± 3% to 766 ± 4%. The further investigation of the extractives with FTIR shows that the newly generated extractives are organic compounds containing C-H and C˭C bonds, with molecular weight ranging from 26,500 to 46,300. SEM characterization shows smoother surface with holes disappearing with increasing absorbed doses, consistent with "softer" material because of radiolysis. Dynamic mechanical study of BRP show that tan δ first slightly then obviously increases with increasing absorbed dose, while storage modulus slightly decreases. The tensile testing shows that the tensile strength decreases while the elongation at break increases with increasing dose. The positron annihilation lifetime spectroscopy show no obvious relations between free volume parameters and the damping properties, indicating the complicated influencing factors of damping properties.
PDMS Network Structure-Property Relationships: Influence of Molecular Architecture on Mechanical and Wetting Properties

NASA Astrophysics Data System (ADS)

Melillo, Matthew Joseph

Poly(dimethylsiloxane) (PDMS) is one of the most common elastomers, with applications ranging from sealants and marine-antifouling coatings to medical devices and absorbents for water treatment. Fundamental understanding of how liquids spread on the surface of and absorb into and leach out of PDMS networks is of critical importance for the design and use in another application - microfluidic devices. The growing use of PDMS in microfluidic devices raises the concern that some researchers may use this material without fully understanding all of its advantages, drawbacks, and intricacies. The primary goal of this Ph.D. dissertation is to elucidate PDMS network molecular structure to macroscopic property relationships and to demonstrate how molecular architecture can alter dynamic mechanical and wetting characteristics. We prepare PDMS materials by using vinyl/ tetrakis(dimethylsiloxy)silane (TDSS) and silanol/ tetraethylorthosilicate (TEOS) combinations of PDMS end-groups and crosslinkers as two model systems. Under constant curing conditions, we systematically study the effects of polymer molecular weight, loading of crosslinker, and end-group chemical functionality on the extent of gelation and the dynamic mechanical and water wetting properties of end-linked PDMS networks. The extent of the gelation reaction is determined using the Soxhlet extraction to quantify the amount of material that did and did not participate in the crosslinking reactions, termed the gel and sol fractions, respectively. We use the Miller-Macosko model in conjunction with the gel fraction and precise chemical composition (i.e., stoichiometric ratio and molecular weight) to determine the fractions of elastic and pendant material, the molecular weight between chemical crosslinks, and the average effective functionality of the crosslinker molecule. Based on dynamic mechanical testing, we find that the maximum storage moduli are achieved at optimal stoichiometric conditions in the vinyl/TDSS and commercial PDMS-based Sylgard 184 composite, but only keep improving with additional crosslinker in the silanol/TEOS systems due to in situ TEOS aggregation. We relate molecular network topology to mechanical properties using outputs from the Miller-Macosko model in the vinyl/TDSS system. The elastic fraction and storage modulus correlate well, as do the pendant fraction and the loss tangent, demonstrating the importance of each fraction in bulk mechanical properties. By studying the dynamic behavior of water droplets wetting PDMS substrates, we observe non-linear wetting behaviors that are markedly different from linear behaviors seen on glassy polymer substrates. The non-linear behavior is only observed prior to extraction, while after extraction, both systems demonstrate behavior similar to glassy polymers. This reveals the dramatic role small amounts of uncrosslinked materials present in the sol fraction play in the surface wetting dynamics of PDMS materials. We further demonstrate the role of uncrosslinked material by adding silicone oils into otherwise fully crosslinked PDMS networks and study their wetting properties. Through careful formulation and preparation of PDMS materials, compared to simply mixing two formulations present in Sylgard 184, one can apply polymer network models to glean useful information about network topology. The benefits of doing so outweigh the costs. We stress the importance of performing Soxhlet extraction to remove unreacted components from PDMS materials, even when using optimal stoichiometry. These mobile molecules that remain after crosslinking can alter significantly wetting behavior and readily leach into liquid environments. However, it is equally important to stress that Soxhlet extraction will not remove all unreacted material. Some will always remain in PDMS, which is often the practice in preparing microfluidic devices. While Sylgard 184 is very well suited for some applications, the results presented in this dissertation demonstrate to researchers that the material does have its limitations and that other options are available. These findings will aid in the design and implementation of reliable microfluidic devices and other PDMS-based materials that encounter liquid interfaces.
Selective Extraction of Flavonoids from Sophora flavescens Ait. by Mechanochemistry.

PubMed

Zhang, Qihong; Yu, Jingbo; Wang, Yingyao; Su, Weike

2016-07-29

Flavonoids from Sophora flavescens were selectively extracted by mechanochemical-promoted extraction technology (MPET) after using response surface methodology to determine the optimal extraction parameters. The highest yield of 35.17 mg/g was achieved by grinding the roots with Na₂CO₃ (15%) at 440 rpm/min for 17.0 min and water was used as the sole solvent with a ratio of solvent to solid material of 25 mL/g. Flavonoids prepared by MPET demonstrated relatively higher antioxidant activities in subsequent DPPH and hydroxyl radical scavenging assays. Main constituents in the extracts, including kurarinol, kushenol I/N and kurarinone, were characterized by HPLC-MS/MS, indicating good selective extraction by MPET. Physicochemical property changes of powder during mechanochemical milling were identified by scanning electron microscopy, X-ray powder diffraction, and UV-Vis diffuse-reflectance spectroscopy. Compared with traditional extraction methods, MPET possesses notable advantages of higher selectivity, lower extraction temperature, shorter extraction time, and organic solvent free properties.
Polysaccharide-derived mesoporous materials (Starbon®) for sustainable separation of complex mixtures.

PubMed

Zuin, Vânia G; Budarin, Vitaliy L; De Bruyn, Mario; Shuttleworth, Peter S; Hunt, Andrew J; Pluciennik, Camille; Borisova, Aleksandra; Dodson, Jennifer; Parker, Helen L; Clark, James H

2017-09-21

The recovery and separation of high value and low volume extractives are a considerable challenge for the commercial realisation of zero-waste biorefineries. Using solid-phase extractions (SPE) based on sustainable sorbents is a promising method to enable efficient, green and selective separation of these complex extractive mixtures. Mesoporous carbonaceous solids derived from renewable polysaccharides are ideal stationary phases due to their tuneable functionality and surface structure. In this study, the structure-separation relationships of thirteen polysaccharide-derived mesoporous materials and two modified types as sorbents for ten naturally-occurring bioactive phenolic compounds were investigated. For the first time, a comprehensive statistical analysis of the key molecular and surface properties influencing the recovery of these species was carried out. The obtained results show the possibility of developing tailored materials for purification, separation or extraction, depending on the molecular composition of the analyte. The wide versatility and application span of these polysaccharide-derived mesoporous materials offer new sustainable and inexpensive alternatives to traditional silica-based stationary phases.
Influence of Codium tomentosum Extract in the Properties of Alginate and Chitosan Edible Films

PubMed Central

Dias, Juliana R.; Alves, Nuno M.; Pedrosa, Rui; Silva, Susana F. J.

2018-01-01

The growing search for natural alternatives to synthetic food packaging materials and additives has increased, and seaweed extracts’ bioactivity has made them suitable candidates for incorporation in novel edible films. This study aims to investigate the effect of Codium tomentosum seaweed extract (SE) incorporation in alginate and chitosan edible films. Alginate- and chitosan-based films with and without the incorporation of 0.5% SE were characterized according to their physical, optical, mechanical, and thermal properties. Seaweed extract incorporation in chitosan films resulted in an increase of film solubility (50%), elasticity (18%), and decrease of puncture strength (27%) and energy at break (39%). In alginate films, the extract incorporation significantly decreased film solubility (6%), water vapour permeability (46%), and elasticity (24%), and had no effect on thermal properties. Depending on the type of application, the addition of SE in edible films can bring advantages for food conservation. PMID:29614782
Method of printed circuits and semiconductor substrates material parameters extraction using wideband reflection measurements

NASA Astrophysics Data System (ADS)

Savin, A. A.; Guba, V. G.; Ladur, A. A.; Bykova, O. N.

2018-05-01

This paper is dedicated to a new method of high frequency circuits material properties extraction based on the reflection measurements of a line shorted two or more times along its length. The line should be fabricated on the material under test. To achieve more precise calculation results, the proposed method uses processing in the time domain. The experimental results section shows obtained assessments for relative permittivity and dielectric loss tangent of the RO4350B hydrocarbon ceramic laminate. Measurements have been conducted over the frequency range up to 20 GHz.
Eco-sustainable systems based on poly(lactic acid), diatomite and coffee grounds extract for food packaging.

PubMed

Cacciotti, Ilaria; Mori, Stefano; Cherubini, Valeria; Nanni, Francesca

2018-06-01

In the food packaging sector many efforts have been (and are) devoted to the development of new materials in order to reply to an urgent market demand for green and eco-sustainable products. Particularly a lot of attention is currently devoted both to the use of compostable and biobased polymers as innovative and promising alternative to the currently used petrochemical derived polymers, and to the re-use of waste materials coming from agriculture and food industry. In this work, multifunctional eco-sustainable systems, based on poly(lactic acid) (PLA) as biopolymeric matrix, diatomaceous earth as reinforcing filler and spent coffee grounds extract as oxygen scavenger, were produced for the first time, in order to provide a simultaneous improvement of mechanical and gas barrier properties. The influence of the diatomite and the spent coffee grounds extract on the microstructural, mechanical and oxygen barrier properties of the produced films was deeply investigated by means of X-Ray diffraction (XRD), infrared spectroscopy (FT-IR, ATR), scanning electron microscopy (SEM), uniaxial tensile tests, O 2 permeabilimetry measurements. An improvement of both mechanical and oxygen barrier properties was recorded for systems characterised by the co-presence of diatomite and coffee grounds extract, suggesting a possible synergic effect of the two additives. Copyright © 2018 Elsevier B.V. All rights reserved.
Carbon Nanotubes Application in the Extraction Techniques of Pesticides: A Review.

PubMed

Jakubus, Aleksandra; Paszkiewicz, Monika; Stepnowski, Piotr

2017-01-02

Carbon nanotubes (CNTs) are currently one of the most promising groups of materials with some interesting properties, such as lightness, rigidity, high surface area, high mechanical strength in tension, good thermal conductivity or resistance to mechanical damage. These unique properties make CNTs a competitive alternative to conventional sorbents used in analytical chemistry, especially in extraction techniques. The amount of work that discusses the usefulness of CNTs as a sorbent in a variety of extraction techniques has increased significantly in recent years. In this review article, the most important feature and different applications of solid-phase extraction (SPE), including, classical SPE and dispersive SPE using CNTs for pesticides isolation from different matrices, are summarized. Because of high number of articles concerning the applicability of carbon materials to extraction of pesticides, the main aim of proposed publication is to provide updated review of the latest uses of CNTs by covering the period 2006-2015. Moreover, in this review, the recent papers and this one, which are covered in previous reviews, will be addressed and particular attention has been paid on the division of publications in terms of classes of pesticides, in order to systematize the available literature reports.

The effect of calcination conditions on the graphitizability of novel synthetic and coal-derived cokes

NASA Astrophysics Data System (ADS)

Bennett, Barbara Ellen

The effects of calcination heating rate and ultimate calcination temperature upon calcined coke and subsequent graphitic material microstructures were studied for materials prepared from three different precursors. The pitch precursors used were Mitsubishi AR pitch (a synthetic, 100% mesophase pitch), the NMP-extracted portion of a raw coal, and the NMP-extracted fraction of a coal liquefaction residue obtained from an HTI pilot plant. These materials were all green-coked under identical conditions. Optical microscopy confirmed that the Mitsubishi coke was very anisotropic and the HTI coke was nearly as anisotropic. The coke produced from the direct coal extract was very isotropic. Crystalline development during calcination heating was verified by high-temperature x-ray diffraction. Experiments were performed to ascertain the effects of varying calcination heating rate and ultimate temperature. It was determined that calcined coke crystallite size increased with increasing temperature for all three materials but was found to be independent of heating rate. The graphene interplanar spacing decreased with increasing temperature for the isotropic NMP-extract material but increased with increasing temperature for the anisotropic materials---Mitsubishi and HTI cokes. Graphene interplanar spacing was also found to be independent of heating rate. Calcined coke real densities were, likewise, found to be independent of heating rate. The anisotropic cokes (Mitsubishi and HTI) exhibited increasing real density with increasing calcination temperature. The NMP-extract coke increased in density up to 1050°C and then suffered a dramatic reduction in real density when heated to 1250°C. This is indicative of puffing. Since there was no corresponding disruption in the crystalline structure, the puffing phenomena was determined to be intercrystalline rather than intracrystalline. After the calcined cokes were graphitized (under identical conditions), the microstructures were re-evaluated. The crystalline properties of the graphitic materials appeared to be independent of calcination conditions---both heating rate and final temperature---for all samples prepared from any given precursor. The calcination step did not influence the microstructure or graphitizability of any of the three materials. The crystallinity of a graphitic material appears to be dictated by the properties of the green coke and cannot be altered by manipulating calcination conditions.
Tunable dynamic response of magnetic gels: Impact of structural properties and magnetic fields

NASA Astrophysics Data System (ADS)

Tarama, Mitsusuke; Cremer, Peet; Borin, Dmitry Y.; Odenbach, Stefan; Löwen, Hartmut; Menzel, Andreas M.

2014-10-01

Ferrogels and magnetic elastomers feature mechanical properties that can be reversibly tuned from outside through magnetic fields. Here we concentrate on the question of how their dynamic response can be adjusted. The influence of three factors on the dynamic behavior is demonstrated using appropriate minimal models: first, the orientational memory imprinted into one class of the materials during their synthesis; second, the structural arrangement of the magnetic particles in the materials; and third, the strength of an external magnetic field. To illustrate the latter point, structural data are extracted from a real experimental sample and analyzed. Understanding how internal structural properties and external influences impact the dominant dynamical properties helps to design materials that optimize the requested behavior.
Characterization of Meta-Materials Using Computational Electromagnetic Methods

NASA Technical Reports Server (NTRS)

Deshpande, Manohar; Shin, Joon

2005-01-01

An efficient and powerful computational method is presented to synthesize a meta-material to specified electromagnetic properties. Using the periodicity of meta-materials, the Finite Element Methodology (FEM) is developed to estimate the reflection and transmission through the meta-material structure for a normal plane wave incidence. For efficient computations of the reflection and transmission over a wide band frequency range through a meta-material a Finite Difference Time Domain (FDTD) approach is also developed. Using the Nicholson-Ross method and the Genetic Algorithms, a robust procedure to extract electromagnetic properties of meta-material from the knowledge of its reflection and transmission coefficients is described. Few numerical examples are also presented to validate the present approach.
3 CFR 13617 - Executive Order 13617 of June 25, 2012. Blocking Property of the Government of the Russian...

Code of Federal Regulations, 2013 CFR

2013-01-01

... Extracted From Nuclear Weapons 13617 Order 13617 Presidential Documents Executive Orders Executive Order... to the Disposition of Highly Enriched Uranium Extracted From Nuclear Weapons By the authority vested... accumulation of a large volume of weapons-usable fissile material in the territory of the Russian Federation...
Advances in organic-inorganic hybrid sorbents for the extraction of organic and inorganic pollutants in different types of food and environmental samples.

PubMed

Ng, Nyuk-Ting; Kamaruddin, Amirah Farhan; Wan Ibrahim, Wan Aini; Sanagi, Mohd Marsin; Abdul Keyon, Aemi S

2018-01-01

The efficiency of the extraction and removal of pollutants from food and the environment has been an important issue in analytical science. By incorporating inorganic species into an organic matrix, a new material known as an organic-inorganic hybrid material is formed. As it possesses high selectivity, permeability, and mechanical and chemical stabilities, organic-inorganic hybrid materials constitute an emerging research field and have become popular to serve as sorbents in various separaton science methods. Here, we review recent significant advances in analytical solid-phase extraction employing organic-inorganic composite/nanocomposite sorbents for the extraction of organic and inorganic pollutants from various types of food and environmental matrices. The physicochemical characteristics, extraction properties, and analytical performances of sorbents are discussed; including morphology and surface characteristics, types of functional groups, interaction mechanism, selectivity and sensitivity, accuracy, and regeneration abilities. Organic-inorganic hybrid sorbents combined with extraction techniques are highly promising for sample preparation of various food and environmental matrixes with analytes at trace levels. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
[The influence of stinging nettle (Urtica dioica L.) extracts on the activity of catalase in THP1 monocytes/macrophages].

PubMed

Wolska, Jolanta; Janda, Katarzyna; Szkyrpan, Sylwia; Gutowska, Izabela

2015-01-01

Stinging nettle (Urtica dioicd L.) is one of the most valuable plants used in phytotherapy. The herbal raw material is a herb (Urticae herba), leaves (Urticae folium), roots (Urticae radix) and seeds (Urticae semina). This plant is a good source of vitamins, minerals, fibre, protein and biologically active compounds with antioxidant properties. The literature provides limited information about the chemical composition and properties of the seed heads. No papers are available on the effect of extracts of this plant on catalase activity in human cells. The aim of this study was to investigate the impact of stinging nettle (Urtica dioica L.) extracts on the antioxidant activity of catalase in THP1 macrophages. Two types of extracts: water and alcohol, at two different concentrations, were used in experiments. Nettle was collected in September and October in 2012 in the area of Szczecin. The collected plant material was frozen and lyophilized. After those procedures water and alcohol extracts of nettle were prepared and then added to THP1 cells. The antioxidant activity of catalase was established with the spectrophotometric method. The study showed that both extracts (water and alcohol) significantly increased the antioxidant activity of catalase in THP1 cells. The increase in catalase was directly proportional to the concentration of the added alcohol extract.
Molecularly imprinted polymer/cryogel composites for solid-phase extraction of bisphenol A from river water and wine.

PubMed

Baggiani, Claudio; Baravalle, Patrizia; Giovannoli, Cristina; Anfossi, Laura; Giraudi, Gianfranco

2010-05-01

Superporous monolithic hydrogels (cryogel monoliths) are elastic, sponge-like materials that can be prepared in an aqueous medium through a cryotropic gelation technique. These monoliths show interesting properties for the development of high-throughput solid-phase extraction supports to treat large volumes of aqueous samples. In this work, a cryogel-supported molecularly imprinted solid-phase extraction approach for the endocrine disruptor bisphenol A (BPA) from river water and wine samples is presented. An imprinted polymer with molecular recognition properties for BPA was prepared in acetonitrile by thermal polymerization of a mixture of 4,4'-dihydroxy-2,2-diphenyl-1,1,1,3,3,3-trifluoropropane as a mimic template of BPA, 4-vinylpyridine and trimethylolpropane trimethacrylate in a molar ratio of 1 + 6 + 6. Fine imprinted particles (<10 microm) were embedded in a poly-acrylamide-co-N,N'-methylenbisacrylamide cryogel obtained by ammonium persulfate-induced cryopolymerization at -18 degrees C. The resulting monolithic gel was evaluated for its use as a sorbent support in an off-line solid-phase extraction approach to recover BPA from dilute aqueous samples with minimum pre-loading work-up. The optimized extraction protocol resulted in a reliable MISPE method suitable to selectively extract and preconcentrate BPA from river water and red wine samples, demonstrating the practical feasibility of cryogel-trapped imprinted polymers as solid-phase extraction materials.
Comparison of UV Protection Properties of Cotton Fabrics Treated with Aqueous and Methanolic Extracts of Achyranthes aspera and Alhagi maurorum Plants.

PubMed

Nazir, Ahsan; Saleem, Muhammad Asad; Nazir, Faiza; Hussain, Tanveer; Faizan, Muhammad Qasim; Usman, Muhammad

2016-03-01

UV radiations are high-energy radiations present in sunlight that can damage human skin. Protection against these radiations becomes vital especially in those areas of the globe where UV index is quite high that makes the inhabitants more prone to dangerous effects of UV radiations. Clothing materials are good blockers of UV radiations, particularly when the fabric cover factor is high and/or the fabrics contain suitable UV-blocking finishes. In this study, effect of application of aqueous and methanolic extracts of two different plants, i.e., Achyranthes aspera and Alhagi maurorum on UV protection properties of cotton fabric was investigated. The results showed that the fabric samples treated with extracts of both the plants have excellent UV protection properties as indicated by their ultraviolet protection factor. It was concluded that both the aqueous and methanolic plant extracts are very effective in blocking UVA and UVB radiations, when applied on cotton fabrics. The UV protection performance of Achyranthes aspera extracts was much better as compared to that of Alhagi maurorum, and methanolic extracts of both the plants outperformed the aqueous extracts in terms of UV protection. © 2016 The American Society of Photobiology.
PHYTOCHEMICAL SCREENING, ANTI-INFLAMMATORY AND ANALGESIC PROPERTIES OF PENTANISIA PRUNELLOIDES FROM THE EASTERN CAPE PROVINCE, SOUTH AFRICA

PubMed Central

Mathews, Miya Gugulethu; Ajayi, Oyemitan Idris; Opeoluwa, Oyedeji Oyehan; Oluwatobi, Oluwafemi Samuel; Benedicta N, Nkeh-Chungag; Phindile, Songca Sandile; Oyedeji; Omowumi, Adebola

2016-01-01

Background: Pentanisia prunelloides is a medicinal plant widely used to remedy various ailments including infections, fever and rheumatism in Eastern Cape Province of South Africa. There is scanty report on the phytochemical and biological properties of the plant; hence various solvent extracts of the dried plant materials were phytochemically screened, and its aqueous extract evaluated for acute toxicity effect, analgesic and antiinflammatory properties in rodents. Methods and Materials: Different extracts of both leaf and rhizome were obtained separately with ethanol, methanol and water. Portions of the filtrate were used for qualitative screening of secondary metabolites and remaining portions were concentrated and dried. Dried grounded leaf and rhizome of the plant were also used for quantitative screening for some major components. The aqueous extract of the leaf and rhizome were used for acute toxicity (LD50) test, antiinflammatory and analgesic activities in rodents. Results: The qualitative phytochemical screening showed the presence of several phytoconstituents with saponins, flavonoids and alkaloids constituting highest constituents in the leaf and rhizome. The LD50: of the aqueous extracts (from leaf or rhizome) was found to be ≥5000 mg/kg orally. The leaf and rhizome aqueous extract (250-500 mg/kg) significantly (p<0.01) reduced egg albumin-induced paw oedema and paw licking in mice induced by formalin, signifying antinociceptive and antiinflammatory activities respectively. Conclusion: It is concluded that the leaf and rhizome of P. prunelloides are rich in various phytochemicals which could be associated with their medicinal uses. The aqueous leaf and rhizome extracts are similarly non-toxic orally, showed antiinflammatory and analgesic potentials thus rationalizing its use in folkloric medicine. PMID:28480377
Computational discovery of extremal microstructure families

PubMed Central

Chen, Desai; Skouras, Mélina; Zhu, Bo; Matusik, Wojciech

2018-01-01

Modern fabrication techniques, such as additive manufacturing, can be used to create materials with complex custom internal structures. These engineered materials exhibit a much broader range of bulk properties than their base materials and are typically referred to as metamaterials or microstructures. Although metamaterials with extraordinary properties have many applications, designing them is very difficult and is generally done by hand. We propose a computational approach to discover families of microstructures with extremal macroscale properties automatically. Using efficient simulation and sampling techniques, we compute the space of mechanical properties covered by physically realizable microstructures. Our system then clusters microstructures with common topologies into families. Parameterized templates are eventually extracted from families to generate new microstructure designs. We demonstrate these capabilities on the computational design of mechanical metamaterials and present five auxetic microstructure families with extremal elastic material properties. Our study opens the way for the completely automated discovery of extremal microstructures across multiple domains of physics, including applications reliant on thermal, electrical, and magnetic properties. PMID:29376124
Combination of sorption properties of polydimethylsiloxane and solid-phase extraction sorbents in a single composite material for the passive sampling of polar and apolar pesticides in water.

PubMed

Martin, Alexis; Margoum, Christelle; Coquery, Marina; Randon, Jérôme

2016-10-01

Passive sampling techniques have been developed as an alternative method for in situ integrative monitoring of trace levels of neutral pesticides in environmental waters. The objective of this work was to develop a new receiving phase for pesticides with a wide range of polarities in a single step. We describe the development of three new composite silicone rubbers, combining polydimethylsiloxane mechanical and sorption properties with solid-phase extraction sorbents, prepared as a receiving phase for passive sampling. A composite silicone rubber composed of polydimethylsiloxane/poly(divinylbenzene-co-N-vinylpyrrolidone) was selected by batch experiments for its high sorption properties for pesticides with octanol-water partition coefficients ranging from 2.3 to 5.5. We named this composite material "Polar/Apolar Composite Silicone Rubber". A structural study by scanning electron microscopy confirmed the homogeneous dispersion of the sorbent particles and the encapsulation of particles within the polydimethylsiloxane matrix. We also demonstrate that this composite material is resistant to common solvents used for the back-extraction of analytes and has a maximal resistance temperature of 350°C. Therefore, the characteristics of the "Polar/Apolar Composite Silicone Rubber" meet most of the criteria for use as a receiving phase for the passive sampling of pesticides. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Spectral reflectance properties of carbon-bearing materials

NASA Technical Reports Server (NTRS)

Cloutis, Edward A.; Gaffey, Michael J.; Moslow, Thomas F.

1994-01-01

The 0.3-2.6 micrometers spectral reflectance properties of carbon polymorphs (graphite, carbon black, diamond), carbides (silicon carbide, cementite), and macromolecular organic-bearing materials (coal, coal tar extract, oil sand, oil shale) are found to vary from sample to sample and among groups. The carbon polymorphs are readily distinguishable on the basis of their visible-near infrared spectral slopes and shapes. The spectra of macromolecular organic-bearing materials show increases in reflectance toward longer wavelengths, exceeding the reflectance rise of more carbon-rich materials. Reflectance spectra of carbonaceous materials are affected by the crystal structure, composition, and degree of order/disorder of the samples. The characteristic spectral properties can potentially be exploited to identify individual carbonaceous grains in meteorites (as separates or in situ) or to conduct remote sensing geothermometry and identification of carbonaceous phases on asteroids.
The investigation of some bioactive compounds and antioxidant properties of hawthorn (Crataegus monogyna subsp. monogyna Jacq)

PubMed Central

Keser, Serhat; Celik, Sait; Turkoglu, Semra; Yilmaz, Ökkes; Turkoglu, Ismail

2014-01-01

Aim: The antioxidant and pharmacological effects of hawthorn have mainly been attributed to the polyphenolic contents. The aim of this research is to determine some bioactive compounds and antioxidant properties of hawthorn aqueous and ethanol extracts of leaves, flowers, and ripened fruits. Materials and Methods: For this purpose, antioxidant activities of extracts were assessed on DPPH•, ABTS•+, superoxide scavenging, reducing power and ferrous metal chelating activity assays and phenolic content of extracts was determined by Folin—Cioacalteu’s reagent. Results: The flavonoids including rutin, apigenin, myricetin, quercetin, naringenin and kaempferol, were identified by high-performance liquid chromatography in the hawthorn extract. Conclusion: It was observed the aqueous and ethanol extracts of Crataegus monogyna subsp. monogyna fruits showed the highest activity in reducing power and metal chelating activity assays. In addition, it was determined that the aqueous flower extract showed higher flavonoid content than aqueous leaves extract. The antioxidant and pharmacological effects of hawthorn have mainly been attributed to the polyphenolic contents. PMID:26401347
A general-purpose machine learning framework for predicting properties of inorganic materials

DOE PAGES

Ward, Logan; Agrawal, Ankit; Choudhary, Alok; ...

2016-08-26

A very active area of materials research is to devise methods that use machine learning to automatically extract predictive models from existing materials data. While prior examples have demonstrated successful models for some applications, many more applications exist where machine learning can make a strong impact. To enable faster development of machine-learning-based models for such applications, we have created a framework capable of being applied to a broad range of materials data. Our method works by using a chemically diverse list of attributes, which we demonstrate are suitable for describing a wide variety of properties, and a novel method formore » partitioning the data set into groups of similar materials to boost the predictive accuracy. In this manuscript, we demonstrate how this new method can be used to predict diverse properties of crystalline and amorphous materials, such as band gap energy and glass-forming ability.« less
A general-purpose machine learning framework for predicting properties of inorganic materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ward, Logan; Agrawal, Ankit; Choudhary, Alok

A very active area of materials research is to devise methods that use machine learning to automatically extract predictive models from existing materials data. While prior examples have demonstrated successful models for some applications, many more applications exist where machine learning can make a strong impact. To enable faster development of machine-learning-based models for such applications, we have created a framework capable of being applied to a broad range of materials data. Our method works by using a chemically diverse list of attributes, which we demonstrate are suitable for describing a wide variety of properties, and a novel method formore » partitioning the data set into groups of similar materials to boost the predictive accuracy. In this manuscript, we demonstrate how this new method can be used to predict diverse properties of crystalline and amorphous materials, such as band gap energy and glass-forming ability.« less
77 FR 38457 - Blocking Property of the Government of the Russian Federation Relating to the Disposition of...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-27

... Extracted From Nuclear Weapons #0; #0; #0; Presidential Documents #0; #0; #0;#0;Federal Register / Vol. 77... Federation Relating to the Disposition of Highly Enriched Uranium Extracted From Nuclear Weapons By the... the accumulation of a large volume of weapons-usable fissile material in the territory of the Russian...
A Direct Method to Extract Transient Sub-Gap Density of State (DOS) Based on Dual Gate Pulse Spectroscopy

NASA Astrophysics Data System (ADS)

Dai, Mingzhi; Khan, Karim; Zhang, Shengnan; Jiang, Kemin; Zhang, Xingye; Wang, Weiliang; Liang, Lingyan; Cao, Hongtao; Wang, Pengjun; Wang, Peng; Miao, Lijing; Qin, Haiming; Jiang, Jun; Xue, Lixin; Chu, Junhao

2016-06-01

Sub-gap density of states (DOS) is a key parameter to impact the electrical characteristics of semiconductor materials-based transistors in integrated circuits. Previously, spectroscopy methodologies for DOS extractions include the static methods, temperature dependent spectroscopy and photonic spectroscopy. However, they might involve lots of assumptions, calculations, temperature or optical impacts into the intrinsic distribution of DOS along the bandgap of the materials. A direct and simpler method is developed to extract the DOS distribution from amorphous oxide-based thin-film transistors (TFTs) based on Dual gate pulse spectroscopy (GPS), introducing less extrinsic factors such as temperature and laborious numerical mathematical analysis than conventional methods. From this direct measurement, the sub-gap DOS distribution shows a peak value on the band-gap edge and in the order of 1017-1021/(cm3·eV), which is consistent with the previous results. The results could be described with the model involving both Gaussian and exponential components. This tool is useful as a diagnostics for the electrical properties of oxide materials and this study will benefit their modeling and improvement of the electrical properties and thus broaden their applications.
Development of tea extracts and chitosan composite films for active packaging materials.

PubMed

Peng, Yong; Wu, Yan; Li, Yunfei

2013-08-01

The effects of 0.5%, 1% and 2% green tea extracts (GTE) and black tea extracts (BTE) on the physical, structural and antioxidant properties of chitosan films were investigated. Results showed that the addition of tea extracts significantly decreased water vapour permeability and increased the antioxidant ability of films. The DPPH radical scavenging ability of GTE films was stronger than that of BTE films in all food simulants (0%, 20%, 75% and 95% ethanol). The equilibration time in different food simulants decreased with the increased ethanol concentration. DSC and FTIR spectra analysis indicated that there was strong interaction in film matrix, which could be reflected by the physical and mechanical properties of composite films. This study revealed that an active chitosan film could be obtained by incorporation of tea extracts, which may provide new formulation options for developing an antioxidant active packaging. Copyright © 2013 Elsevier B.V. All rights reserved.
Graphene-based materials: fabrication and application for adsorption in analytical chemistry.

PubMed

Wang, Xin; Liu, Bo; Lu, Qipeng; Qu, Qishu

2014-10-03

Graphene, a single layer of carbon atoms densely packed into a honeycomb crystal lattice with unique electronic, chemical, and mechanical properties, is the 2D allotrope of carbon. Owing to the remarkable properties, graphene and graphene-based materials are likely to find potential applications as a sorbent in analytical chemistry. The current review focuses predominantly on the recent development of graphene-based materials and demonstrates their enhanced performance in adsorption of organic compounds, metal ions, and solid phase extraction as well as in separation science since mostly 2012. Copyright © 2014 Elsevier B.V. All rights reserved.
Design of impact-resistant boron/aluminum large fan blade

NASA Technical Reports Server (NTRS)

Salemme, C. T.; Yokel, S. A.

1978-01-01

The technical program was comprised of two technical tasks. Task 1 encompassed the preliminary boron/aluminum fan blade design effort. Two preliminary designs were evolved. An initial design consisted of 32 blades per stage and was based on material properties extracted from manufactured blades. A final design of 36 blades per stage was based on rule-of-mixture material properties. In Task 2, the selected preliminary blade design was refined via more sophisticated analytical tools. Detailed finite element stress analysis and aero performance analysis were carried out to determine blade material frequencies and directional stresses.

Characterization and antimicrobial properties of food packaging methylcellulose films containing stem extract of Ginja cherry.

PubMed

Campos, Débora; Piccirillo, Clara; Pullar, Robert C; Castro, Paula Ml; Pintado, Maria M E

2014-08-01

Food contamination and spoilage is a problem causing growing concern. To avoid it, the use of food packaging with appropriate characteristics is essential; ideally, the packaging should protect food from external contamination and exhibit antibacterial properties. With this aim, methylcellulose (MC) films containing natural extracts from the stems of Ginja cherry, an agricultural by-product, were developed and characterized. The antibacterial activity of films was screened by the disc diffusion method and quantified using the viable cell count assay. The films inhibited the growth of both Gram-positive and Gram-negative strains (Listeria innocua, methicillin-sensitive Staphylococcus aureus, methicillin-resistant S. aureus, Salmonella Enteritidis, Escherichia coli). For the films with lower extract content, effectiveness against the microorganisms depended on the inoculum concentration. Scanning electron microscope images of the films showed that those containing the extracts had a smooth and continuous structure. UV-visible spectroscopy showed that these materials do not transmit light in the UV. This study shows that MC films containing agricultural by-products, in this case Ginja cherry stem extract, could be used to prevent food contamination by relevant bacterial strains and degradation by UV light. Using such materials in food packaging, the shelf life of food products could be extended while utilizing an otherwise wasted by-product. © 2013 Society of Chemical Industry.
Step-wise supercritical extraction of carbonaceous residua

DOEpatents

Warzinski, Robert P.

1987-01-01

A method of fractionating a mixture containing high boiling carbonaceous material and normally solid mineral matter includes processing with a plurality of different supercritical solvents. The mixture is treated with a first solvent of high critical temperature and solvent capacity to extract a large fraction as solute. The solute is released as liquid from solvent and successively treated with other supercritical solvents of different critical values to extract fractions of differing properties. Fractionation can be supplemented by solute reflux over a temperature gradient, pressure let down in steps and extractions at varying temperature and pressure values.
Bamboo–Polylactic Acid (PLA) Composite Material for Structural Applications

PubMed Central

Pozo Morales, Angel; Güemes, Alfredo; Fernandez-Lopez, Antonio; Carcelen Valero, Veronica; De La Rosa Llano, Sonia

2017-01-01

Developing an eco-friendly industry based on green materials, sustainable technologies, and optimum processes with low environmental impact is a general societal goal, but this remains a considerable challenge to achieve. Despite the large number of research on green structural composites, limited investigation into the most appropriate manufacturing methodology to develop a structural material at industrial level has taken place. Laboratory panels have been manufactured with different natural fibers but the methodologies and values obtained could not be extrapolated at industrial level. Bamboo industry panels have increased in the secondary structural sector such as building application, flooring and sport device, because it is one of the cheapest raw materials. At industrial level, the panels are manufactured with only the inner and intermediate region of the bamboo culm. However, it has been found that the mechanical properties of the external shells of bamboo culm are much better than the average cross-sectional properties. Thin strips of bamboo (1.5 mm thick and 1500 mm long) were machined and arranged with the desired lay-up and shape to obtain laminates with specific properties better than those of conventional E-Glass/Epoxy laminates in terms of both strength and stiffness. The strips of bamboo were bonded together by a natural thermoplastic polylactic acid (PLA) matrix to meet biodegradability requirements. The innovative mechanical extraction process developed in this study can extract natural strip reinforcements with high performance, low cost, and high rate, with no negative environmental impact, as no chemical treatments are used. The process can be performed at the industrial level. Furthermore, in order to validate the structural applications of the composite, the mechanical properties were analyzed under ageing conditions. This material could satisfy the requirements for adequate mechanical properties and life cycle costs at industrial sectors such as energy or automotive. PMID:29120398
Bamboo-Polylactic Acid (PLA) Composite Material for Structural Applications.

PubMed

Pozo Morales, Angel; Güemes, Alfredo; Fernandez-Lopez, Antonio; Carcelen Valero, Veronica; De La Rosa Llano, Sonia

2017-11-09

Developing an eco-friendly industry based on green materials, sustainable technologies, and optimum processes with low environmental impact is a general societal goal, but this remains a considerable challenge to achieve. Despite the large number of research on green structural composites, limited investigation into the most appropriate manufacturing methodology to develop a structural material at industrial level has taken place. Laboratory panels have been manufactured with different natural fibers but the methodologies and values obtained could not be extrapolated at industrial level. Bamboo industry panels have increased in the secondary structural sector such as building application, flooring and sport device, because it is one of the cheapest raw materials. At industrial level, the panels are manufactured with only the inner and intermediate region of the bamboo culm. However, it has been found that the mechanical properties of the external shells of bamboo culm are much better than the average cross-sectional properties. Thin strips of bamboo (1.5 mm thick and 1500 mm long) were machined and arranged with the desired lay-up and shape to obtain laminates with specific properties better than those of conventional E-Glass/Epoxy laminates in terms of both strength and stiffness. The strips of bamboo were bonded together by a natural thermoplastic polylactic acid (PLA) matrix to meet biodegradability requirements. The innovative mechanical extraction process developed in this study can extract natural strip reinforcements with high performance, low cost, and high rate, with no negative environmental impact, as no chemical treatments are used. The process can be performed at the industrial level. Furthermore, in order to validate the structural applications of the composite, the mechanical properties were analyzed under ageing conditions. This material could satisfy the requirements for adequate mechanical properties and life cycle costs at industrial sectors such as energy or automotive.
Hydrophilic Dogwood Extracts as Materials for Reducing the Skin Irritation Potential of Body Wash Cosmetics.

PubMed

Nizioł-Łukaszewska, Zofia; Osika, Paweł; Wasilewski, Tomasz; Bujak, Tomasz

2017-02-19

A significant problem related to the use of surfactants in body wash cosmetics is their propensity to trigger skin irritations. Only scarce literature exists on the effect of plant extracts on the skin irritation potential. The present study is an attempt to determine the effect of hydrophilic dogwood extracts on the irritant potential of body wash gels. Extractants used in the study were water and mixtures of water with glycerine, water with trimethylglycine (betaine), and water with plant-derived glycol (propanediol). The basic biochemical properties, i.e., the ability to neutralize free radicals, and the content of polyphenols, anthocyanins and flavonoids, were determined. An attempt was undertaken to analyze the impact of the extract added to natural body wash gel formulations on product properties. The skin irritation potential was assessed by determining the zein number and the increase in the pH level of the bovine serum albumin (BSA) solution. The viscosity and foaming ability of the resulting products were evaluated. The studies revealed that an addition of dogwood extract contributes to an improvement in the properties of body wash gels and significantly increases the safety of product use through reducing the skin irritation effect.
Valeriana officinalis Dry Plant Extract for Direct Compression: Preparation and Characterization.

PubMed

Gallo, Loreana; Ramírez-Rigo, María Veronica; Piña, Juliana; Palma, Santiago; Allemandi, Daniel; Bucalá, Verónica

2012-01-01

Valeriana officinalis L. (Valerianaceae) is one of the most widely used plants for the treatment of anxiety and insomnia. Usually dry plant extracts, including V. officinalis, are hygroscopic materials with poor physico-mechanical properties that can be directly compressed.A V. officinalis dry extract with moderate hygroscocity is suitable for direct compression, and was obtained by using a simple and economical technique. The V. officinalis fluid extract was oven-dried with colloidal silicon dioxide as a drying adjuvant. The addition of colloidal silicon dioxide resulted in a dry plant extract with good physico-mechanical properties for direct compression and lower hygroscopicity than the dry extract without the carrier. The dry plant extract glass transition temperature was considerably above room temperature (about 72 °C). The colloidal silicon dioxide also produced an antiplasticizing effect, improving the powder's physical stability.The pharmaceutical performance of the prepared V. officinalis dry extract was studied through the design of tablets. The manufactured tablets showed good compactability, friability, hardness, and disintegration time. Those containing a disintegrant (Avicel PH 101) exhibited the best pharmaceutical performance, having the lowest disintegration time of around 40 seconds.
Synthesis, Characterization and Application of 1-Butyl-3 Methylimidazolium Chloride as Green Material for Extractive Desulfurization of Liquid Fuel

PubMed Central

Dharaskar, Swapnil A.; Varma, Mahesh N.; Shende, Diwakar Z.; Yoo, Chang Kyoo; Wasewar, Kailas L.

2013-01-01

The possible application of imidazolium ionic liquids as energy-efficient green material for extractive deep desulfurization of liquid fuel has been investigated. 1-Butyl-3-methylimidazolium chloride [BMIM]Cl was synthesized by nucleophilic substitution reaction of n-methylimidazolium and 1-chlorobutane. Molecular structures of the ILs were confirmed by FTIR, 1H-NMR, and 13C-NMR. The thermal properties, conductivity, solubility, water content and viscosity analysis of [BMIM]Cl were carried out. The effects of reaction time, reaction temperature, sulfur compounds, and recycling of IL without regeneration on dibenzothiophene removal of liquid fuel were presented. In the extractive desulfurization process, the removal of dibenzothiophene in n-dodecane using [BMIM]Cl was 81% with mass ratio of 1 : 1, in 30 min at 30°C under the mild reaction conditions. Also, desulfurization of real fuels with IL and multistage extraction were studied. The results of this work might offer significant insights in the perceptive use of imidazoled ILs as energy-efficient green material for extractive deep desulfurization of liquid fuels as it can be reused without regeneration with considerable extraction efficiency. PMID:24307868
A comprehensive review on vanilla flavor: extraction, isolation and quantification of vanillin and others constituents.

PubMed

Sinha, Arun K; Sharma, Upendra K; Sharma, Nandini

2008-06-01

Vanilla, being the world's most popular flavoring materials, finds extensive applications in food, beverages, perfumery and pharmaceutical industry. With the high demand and limited supply of vanilla pods and the continuing increase in their cost, numerous efforts of blending and adulteration in natural vanilla extracts have been reported. Thus, to ensure the quality of vanilla extracts and vanilla-containing products, it is important to develop techniques to verify their authenticity. Quantitatively, vanillin is the major compound present in the vanilla pods and the determination of vanillin is a vital consideration in natural vanilla extracts. This paper provides a comprehensive account of different extraction processes and chromatographic techniques applied for the separation, identification and determination of chemical constituents of vanilla. The review also provides an account of different methods applied for the quantification and the authentification of chemical constituents of vanilla extract. As the various properties of vanilla are attributed to its main constituent vanillin, its physico-chemical and bioactive properties have also been outlined.
Sempervivum davisii: phytochemical composition, antioxidant and lipase-inhibitory activities.

PubMed

Uzun, Yusuf; Dalar, Abdullah; Konczak, Izabela

2017-12-01

Sempervivum davisii Muirhead (Crassulaceae) is a traditional medicinal herb from Eastern Anatolia. To date the composition of phytochemicals and physiological properties of this herb were not subjected to any research. This study identifies compounds in S. davisii hydrophilic extracts and evaluates their potential biological properties. Ethanol-based lyophilized extracts were obtained from aerial parts of plant (10 g of ground dry plant material in 200 mL of acidified aqueous ethanol, shaken for 2 h at 22 °C with supernatant collected and freeze-dried under vacuum). Phytochemical composition was investigated by liquid chromatography mass spectrometry (LC-MS/MS, phenolics) and gas chromatography mass spectrometry (GC-MS, volatiles). Phenolic compounds were quantified by high-performance liquid chromatography (HPLC) and the Folin-Ciocalteu assay. Subsequently, antioxidant capacity [ferric reducing antioxidant power (FRAP), oxygen radical absorbance capacity (ORAC) assays] and enzyme inhibitory properties (isolated porcine pancreatic lipase) of the extracts were determined. Polyphenolic compounds were the main constituents of lyophilized extracts, among which kaempferol glycosides and quercetin hexoside dominated. The extracts exhibited potent antioxidant (FRAP values of 1925.2-5973.3 μM Fe 2+ /g DW; ORAC values of 1858.5-4208.7 μM Trolox Eq./g DW) and moderate lipase inhibitory (IC 50 : 11.6-2.96 mg/mL) activities. Volatile compounds (nonanal, dehydroxylinalool oxide isomers, 2-decenal, 2-undecenal, 2,6-di-tetr-butylphenol) were also found. Phenolic compounds with the dominating kaempferol and quercetin derivatives are the sources of potent antioxidant properties of S. davisii hydrophilic extracts. The extracts exhibit moderate inhibitory properties towards isolated pancreatic lipase.
Synthesis and characterization of biosheet impregnated with Macrotyloma uniflorum extract for burn/wound dressings.

PubMed

Muthukumar, Thangavelu; Senthil, Rethinam; Sastry, Thotapalli Parvathaleswara

2013-02-01

Developing biomaterials having wound healing properties within the search of a common man is the need of hour, particularly in developing and third world countries. Keeping this objective in view we have developed a wound dressing material, in sheet form, containing fish scale collagen (FSC) and physiologically clotted fibrin (PCF), both are by products of aqua food and meat industries respectively. To impart antimicrobial properties to the composite sheet, it was incorporated with Macrotyloma uniflorum plant extract (MPE). SEM pictures have shown that FSC:PCF:MPE composite has fibrous and porous surface which helps in transportation of oxygen as well as absorbing wound fluids and their evaporation. The biomaterials have shown 100% biocompatibility and the percentage cell viability was found to be above 89%. The FSC:PCF:MPE biocomposite film with required mechanical strength, biocompatibility and antimicrobial properties can be tried as a burn/wound dressing material. Copyright © 2012 Elsevier B.V. All rights reserved.
Supercritical fluid extraction of plant flavors and fragrances.

PubMed

Capuzzo, Andrea; Maffei, Massimo E; Occhipinti, Andrea

2013-06-19

Supercritical fluid extraction (SFE) of plant material with solvents like CO₂, propane, butane, or ethylene is a topic of growing interest. SFE allows the processing of plant material at low temperatures, hence limiting thermal degradation, and avoids the use of toxic solvents. Although today SFE is mainly used for decaffeination of coffee and tea as well as production of hop extracts on a large scale, there is also a growing interest in this extraction method for other industrial applications operating at different scales. In this review we update the literature data on SFE technology, with particular reference to flavors and fragrance, by comparing traditional extraction techniques of some industrial medicinal and aromatic crops with SFE. Moreover, we describe the biological activity of SFE extracts by describing their insecticidal, acaricidal, antimycotic, antimicrobial, cytotoxic and antioxidant properties. Finally, we discuss the process modelling, mass-transfer mechanisms, kinetics parameters and thermodynamic by giving an overview of SFE potential in the flavors and fragrances arena.
Method for extracting relevant electrical parameters from graphene field-effect transistors using a physical model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boscá, A., E-mail: alberto.bosca@upm.es; Dpto. de Ingeniería Electrónica, E.T.S.I. de Telecomunicación, Universidad Politécnica de Madrid, Madrid 28040; Pedrós, J.

2015-01-28

Due to its intrinsic high mobility, graphene has proved to be a suitable material for high-speed electronics, where graphene field-effect transistor (GFET) has shown excellent properties. In this work, we present a method for extracting relevant electrical parameters from GFET devices using a simple electrical characterization and a model fitting. With experimental data from the device output characteristics, the method allows to calculate parameters such as the mobility, the contact resistance, and the fixed charge. Differentiated electron and hole mobilities and direct connection with intrinsic material properties are some of the key aspects of this method. Moreover, the method outputmore » values can be correlated with several issues during key fabrication steps such as the graphene growth and transfer, the lithographic steps, or the metalization processes, providing a flexible tool for quality control in GFET fabrication, as well as a valuable feedback for improving the material-growth process.« less
Properties of gelatin film from horse mackerel (Trachurus japonicus) scale.

PubMed

Le, Thuy; Maki, Hiroki; Takahashi, Kigen; Okazaki, Emiko; Osako, Kazufumi

2015-04-01

Optimal conditions for extracting gelatin and preparing gelatin film from horse mackerel scale, such as extraction temperature and time, as well as the protein concentration of film-forming solutions were investigated. Yields of extracted gelatin at 70 °C, 80 °C, and 90 °C for 15 min to 3 h were 1.08% to 3.45%, depending on the extraction conditions. Among the various extraction times and temperatures, the film from gelatin extracted at 70 °C for 1 h showed the highest tensile strength and elongation at break. Horse mackerel scale gelatin film showed the greatly low water vapor permeability (WVP) compared with mammalian or fish gelatin films, maybe due to its containing a slightly higher level of hydrophobic amino acids (total 653 residues per 1000 residues) than that of mammalian, cold-water fish and warm-water fish gelatins. Gelatin films from different preparation conditions showed excellent UV barrier properties at wavelength of 200 nm, although the films were transparent at visible wavelength. As a consequence, it can be suggested that gelatin film from horse mackerel scale extracted at 70 °C for 1 h can be applied to food packaging material due to its lowest WVP value and excellent UV barrier properties. © 2015 Institute of Food Technologists®
Effect of Extrusion on the Mechanical and Rheological Properties of a Reinforced Poly(Lactic Acid): Reprocessing and Recycling of Biobased Materials.

PubMed

Peinado, Víctor; Castell, Pere; García, Lidia; Fernández, Ángel

2015-10-19

The aim of this research paper is to study the behaviour of a common used biopolymer (Poly(Lactic Acid) (PLA)) after several reprocesses and how two different types of additives (a melt strength enhancer and a nanoadditive) affect its mechanical and rheological properties. Systematic extraction of extrudate samples from a twin-screw compounder was done in order to study the effect in the properties of the reprocessed material. Detailed rheological tests on a capillary rheometer as well as mechanical studies on a universal tensile machine after preparation of injected specimens were carried out. Results evidenced that PLA and reinforced PLA materials can be reprocessed and recycled without a remarkable loss in their mechanical properties. Several processing restrictions and specific phenomena were identified and are explained in the present manuscript.
Chemical composition and antibacterial activities of lupin seeds extracts.

PubMed

Lampart-Szczapa, Eleonora; Siger, Aleksander; Trojanowska, Krystyna; Nogala-Kalucka, Małgorzata; Malecka, Maria; Pacholek, Bogdan

2003-10-01

Determination of influence of lupin natural phenolic compounds on antibacterial properties of its seeds was carried out. Raw material were seeds of Lupinus albus, L. luteus, and L. angustifolius. The methods included the determination of the content of proteins, total phenolic compounds, free phenolic acids, and tannins as well as antibacterial properties with ethanol extracts. The content of total phenolic compounds was smaller in testas than in cotyledons and the highest levels are observed in bitter cultivars of Lupinus albus cv. Bac and L. angustifolius cv. Mirela. Lupin tannins mainly occurred in cotyledons of the white lupin, predominantly in the bitter cultivar Bac. Free phenolic acids were mainly found in testas. Only extracts from the testas displayed antibacterial properties, which excludes the possibility of alkaloid influence on the results. The results suggest that inhibition of test bacteria growth depended mainly upon the content of the total phenolic compounds.
Electronic structure and optical properties of some anthocyanins extracted from grapes

NASA Astrophysics Data System (ADS)

Iosub, Ion; Kajzar, Francois; Makowska-Janusik, Malgorzata; Meghea, Aurelia; Tane, Alexandrina; Rau, Ileana

2012-08-01

The pallet of applications of natural dyes and pigments is continuously extending as a stringent need to meet the challenges arisen from sustainable development, particularly related to replacing synthetic chemicals by eco-friendly renewable raw materials. In this respect, the well known nutritive and therapeutic properties demonstrated by anthocyanin compounds present in selective plant extracts of numerous fruits, vegetables and flowers could be largely complemented by their characteristics as chromophores and fluorophores with high potential in promising applications in bio-imaging for diagnostic and therapy, but also in electronic and photonic devices, solar cells, etc. In this context, this paper proposes an improved protocol for extraction and HPLC detection of anthocyanins from black grapes. Moreover, in order to exploit their potential to be applied as chromatic and fluorescence molecular probes, the electronic properties have been studied by correlating spectral characteristics with trichromatic parameters, combined with quantum chemistry computation.
Valorisation of softwood bark through extraction of utilizable chemicals. A review.

PubMed

Jablonsky, M; Nosalova, J; Sladkova, A; Haz, A; Kreps, F; Valka, J; Miertus, S; Frecer, V; Ondrejovic, M; Sima, J; Surina, I

2017-11-01

Softwood bark is an important source for producing chemicals and materials as well as bioenergy. Extraction is regarded as a key technology for obtaining chemicals in general, and valorizing bark as a source of such chemicals in particular. In this paper, properties of 237 compounds identified in various studies dealing with extraction of softwood bark were described. Finally, some challenges and perspectives on the production of chemicals from bark are discussed. Copyright © 2017 Elsevier Inc. All rights reserved.
Activation analysis of admixtures in certain semiconductive materials

NASA Technical Reports Server (NTRS)

Artyukhin, P. I.; Gilbert, E. P.; Pronin, V. A.

1978-01-01

The use of extractions and chromatographic operations to separate macrobases, and to divide elements into groups convenient for gamma-spectrometric analysis is discussed. Methods are described for the activation detection of some impurities in silicon, arsenic, thallium, and trichloromethylsilane, on the basis of the extraction properties of bis(2-chlorethyl ether) and dimethylbenzylalkylammonium chloride. A schematic diagram of the extraction separation of elements-admixture is presented showing the aqueous and organic phases. The content percentage of the various elements are given in tables.
Effect of natural extracts pH on morphological characteristics of hybrid materials based on gold nanoparticles

NASA Astrophysics Data System (ADS)

Olenic, L.; Vulcu, A.; Chiorean, I.; Crisan, M.; Berghian-Grosan, C.; Dreve, S.; David, L.; Tudoran, L. B.; Kacso, I.; Bratu, I.; Neamtu, C.; Voica, C.

2013-11-01

In the present paper we have investigated the pH influence on the morphology of some new hybrid materials based on gold nanoparticles and natural extracts from fruits of Romanian native plants of Adoxaceae family (Viburnum opulus L. and Sambucus nigra L.). It is well known that the natural plants extracts are beneficial for humans thanks to their antioxidant, anti-inflammatory and immunomodulatory effects. The biological activity of these berries is mainly due to their high content of anthocyanins and other polyphenols. The nanoparticles facilitate the penetration of substances in skin, enhancing their antimitotic, anti-inflammatory and antibiotic properties. We have chosen the optimal method to get these materials in which gold nanoparticles of 10-80 nm were obtained. We characterized them by UV-Vis and FT-IR spectroscopy, by TEM and DSC. Creams prepared with the hybrid materials have been tested on psoriatic lesions and the medical results emphasized a remarkable improvement in this diseases.
Cytotoxicity of some edible mushrooms extracts over liver hepatocellular carcinoma cells in conjunction with their antioxidant and antibacterial properties

PubMed Central

Sadi, Gökhan; Emsen, Buğrahan; Kaya, Abdullah; Kocabaş, Aytaç; Çınar, Seval; Kartal, Deniz İrtem

2015-01-01

Background: Mushrooms have been valued for their nutritive content and as traditional medicines; several important medicinal properties of mushrooms have been recognized worldwide. Objective: The purpose of this study was to elucidate the cell growth inhibitory potential of four edible mushrooms; Coprinus comatus (O.F. Mull.) Pers. (Agaricaceae), Tricholoma fracticum (Britzelm.) Kreisel (Tricholomataceae), Rhizopogon luteolus Fr. and Nordholm (Rhizopogonaceae), Lentinus tigrinus (Bull.) Fr. (Polyporaceae) on hepatocellular carcinoma (HepG2) cells in conjunction with their antioxidant and antibacterial capacities. Materials and Methods: Five different extracts of edible mushrooms were obtained using water, methanol, acetone, n-hexane and chloroform as solvent systems for cytotoxic, antioxidant and antibacterial properties. Results: C. comatus showed substantial in vitro cytotoxic activity against HepG2 cell lines with all extracts especially with chloroform 50% inhibition (IC50 value of 0.086 mg/ml) and acetone (IC50 value of 0.420 mg/ml). Chloroform extract of C. comatus had maximum amount of β-carotene (25.94 μg/mg), total phenolic content (76.32 μg/mg) and lycopene (12.00 μg/mg), and n-hexane extract of L. tigrinus had maximum amount of flavonoid (3.67 μg/mg). While chloroform extract of C. comatus showed the highest 2, 2-diphenyl-1-picrylhydrazyl (DPPH) capturing activity (1.579 mg/ml), the best result for metal chelating activity was obtained from methanolic extract (0.842 mg/ml). Moreover, all tested mushrooms demonstrated antibacterial activity and n-hexane extract of L. tigrinus and acetone extracts of T. fracticum were the most active against tested microorganism. Conclusion: These results indicate that different extracts of investigated mushroom have considerable cytotoxic, antioxidant and antibacterial properties and may be utilized as a promising source of therapeutics. PMID:26109775

Determination of orthotropic material properties by modal analysis

NASA Astrophysics Data System (ADS)

Lai, Junpeng

The methodology for determination of orthotropic material properties in plane stress condition will be presented. It is applied to orthotropic laminated plates like printed wiring boards. The first part of the thesis will focus on theories and methodologies. The static beam model and vibratory plate model is presented. The methods are validated by operating a series of test on aluminum. In the static tests, deflection and two directions of strain are measured, thus four of the properties will be identified: Ex, Ey, nuxy, nuyx. Moving on to dynamic test, the first ten modes' resonance frequencies are obtained. The technique of modal analysis is adopted. The measured data is processed by FFT and analyzed by curve fitting to extract natural frequencies and mode shapes. With the last material property to be determined, a finite element method using ANSYS is applied. Along with the identified material properties in static tests, and proper initial guess of the unknown shear modulus, an iterative process creates finite element model and conducts modal analysis with the updating model. When the modal analysis result produced by ANSYS matches the natural frequencies acquired by dynamic test, the process will halt. Then we obtained the last material property in plane stress condition.
Ionic liquid-modified materials for solid-phase extraction and separation: a review.

PubMed

Vidal, Lorena; Riekkola, Marja-Liisa; Canals, Antonio

2012-02-17

In recent years, materials science has propelled to the research forefront. Ionic liquids with unique and fascinating properties have also left their footprints to the developments of materials science during the last years. In this review we highlight some of their recent advances and provide an overview at the current status of ionic liquid-modified materials applied in solid-phase extraction, liquid and gas chromatography and capillary electrochromatography with reference to recent applications. In addition, the potential of ionic liquids in the modification of capillary inner wall in capillary electrophoresis is demonstrated. The main target material modified with ionic liquids is silica, but polymers and monoliths have recently joined the studies. Although imidazolium is still clearly the most commonly used ionic liquid for the covalently modification of materials, the exploitation of pyridinium and phosphonium will most probably increase in the future. Copyright © 2011 Elsevier B.V. All rights reserved.
On the uniqueness of measuring elastoplastic properties from indentation: The indistinguishable mystical materials

NASA Astrophysics Data System (ADS)

Chen, Xi; Ogasawara, Nagahisa; Zhao, Manhong; Chiba, Norimasa

2007-08-01

Indentation is widely used to extract material elastoplastic properties from the measured force-displacement curves. One of the most well-established indentation techniques utilizes dual (or plural) sharp indenters (which have different apex angles) to deduce key parameters such as the elastic modulus, yield stress, and work-hardening exponent for materials that obey the power-law constitutive relationship. However, the uniqueness of such analysis is not yet systematically studied or challenged. Here we show the existence of "mystical materials", which have distinct elastoplastic properties yet they yield almost identical indentation behaviors, even when the indenter angle is varied in a large range. These mystical materials are, therefore, indistinguishable by many existing indentation analyses unless extreme (and often impractical) indenter angles are used. Explicit procedures of deriving these mystical materials are established, and the general characteristics of the mystical materials are discussed. In many cases, for a given indenter angle range, a material would have infinite numbers of mystical siblings, and the existence maps of the mystical materials are also obtained. Furthermore, we propose two alternative techniques to effectively distinguish these mystical materials. The study in this paper addresses the important question of the uniqueness of indentation test, as well as providing useful guidelines to properly use the indentation technique to measure material elastoplastic properties.
[Analytic study of juices obtained by pressure, by cold extraction and warm extraction (the DDS system) of marc from apples of the Golden Delicious variety].

PubMed

Tanner, H

1978-01-01

The cold water extraction of apple press residues to increase the juice yield has found much interest in recent years. Such a process has been developed by a Swiss company, but the food legislation does not permit it yet. Juice yield is increased up to 91 p. 100 (w.). Therefore we investigated the chemical and sensorical properties of pressed juice, cold water extract of press residues and warm water extract (System DDS) of identical raw material. The water extract differs from the pressed juice mainly by an increased amount of non-sugar extract and changes of the pigment and polyphenole content. The cold water extract had more and the better aroma than the warm extract.
The Molecular Design of High-Performance Carbon Materials

DTIC Science & Technology

2008-06-30

Thies MC. Control of mesophase pitch properties by supercritical fluid extraction. Carbon 1998; 36(7-8):953-61. 7] Zhuang M, Gast K, Thies MC...pitch with supercritical toluene. J Supercrit Fluids 1991; 4(1):7-14. 16] Herod AA, Bartle KD, Kandiyoti R. Characterization of heavy...MALDI, mass spectrometry, mesophase, extraction, supercritical , fractionation. 16. SECURITY CLASSIFICATION OF: a. REPORT u b. ABSTRACT u c. THIS
Zero-valent iron/iron oxide-oxyhydroxide/graphene as a magnetic sorbent for the enrichment of polychlorinated biphenyls, polyaromatic hydrocarbons and phthalates prior to gas chromatography-mass spectrometry.

PubMed

Karamani, Anna A; Douvalis, Alexios P; Stalikas, Constantine D

2013-01-04

A composite magnetic material consisting of zero-valent iron, iron oxide-oxyhydroxide and graphene was synthesized and used successfully as a sorbent for the micro solid-phase extraction of PAHs, PCBs and phthalic acid esters. The components endow the composite with multiple characteristics such as adsorption capability and facile removal due to its magnetic properties. Due to the π-π electrostatic stacking property of graphene, the high specific surface area and the adsorption capability of both components, the resulting black flaky Fe(0)/iron oxide-oxyhydroxide/graphene composite showed high extraction efficiency for the target analytes from water samples. Compared with the neat graphene, the composite material has improved properties in terms of microextraction capabilities as both the hydrophobic graphene and zero-valent iron participate in the adsorption of the hydrophobic molecules. The precision from the extraction of all three groups of compounds was lower than 7% and the recoveries were from 90 to 93% from a spiked lake water sample. The high recoveries in relation to the low final volume of the desorption solvent ensure high preconcentration efficiency and a promising sorbent for analytical applications. Copyright © 2012 Elsevier B.V. All rights reserved.
An approach to biomimetics: the natural CAD/CAM restoration: a clinical report.

PubMed

Schlichting, Luís Henrique; Schlichting, Kathryn Klemz; Stanley, Kyle; Magne, Michel; Magne, Pascal

2014-02-01

Those in the dental field have always pursued the perfect dental material for the treatment of compromised teeth. Gold, amalgam, composite resin, glass ionomer, and porcelain have been used. Tooth-like restorative materials (composite resin and porcelain) combined with an effective hard tissue bond have met the growing demand for esthetic or metal-free restorations in the past 15 to 20 years. However, none of those materials can fully mimic the unique properties of dentin (compliance and crack-stopping behavior) and enamel (wear resistance, function). The aim of this article is to report the restoration of an extensively damaged tooth with a natural restoration obtained by milling an extracted third molar tooth with a computer-aided design and computer-aided manufacturing (CAD/CAM) system. The main benefit of this novel technique is the replacement of lost tissues by actual enamel and dentin, with the potential to recover mechanical, esthetic, and biologic properties. The indication for extracting third molars and premolars because of impaction or for orthodontic reasons makes these posterior teeth readily available. The innovation of the method presented here is the optimal use of the extracted tooth substrate thanks to its positioning technique in the CAD/CAM milling chamber. Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.
Phyto-mediated metallic nano-architectures via Melissa officinalis L.: synthesis, characterization and biological properties.

PubMed

Fierascu, Irina; Georgiev, Milen I; Ortan, Alina; Fierascu, Radu Claudiu; Avramescu, Sorin Marius; Ionescu, Daniela; Sutan, Anca; Brinzan, Alexandru; Ditu, Lia Mara

2017-09-29

The development of methods for obtaining new materials with antimicrobial properties, based on green chemistry principles has been a target of research over the past few years. The present paper describes the phyto-mediated synthesis of metallic nano-architectures (gold and silver) via an ethanolic extract of Melissa officinalis L. (obtained by accelerated solvent extraction). Different analytic methods were applied for the evaluation of the extract composition, as well as for the characterization of the phyto-synthesized materials. The cytogenotoxicity of the synthesized materials was evaluated by Allium cepa assay, while the antimicrobial activity was examined by applying both qualitative and quantitative methods. The results demonstrate the synthesis of silver nanoparticles (average diameter 13 nm) and gold nanoparticles (diameter of ca. 10 nm); the bi-metallic nanoparticles proved to have a core-shell flower-like structure, composed of smaller particles (ca. 8 nm). The Ag nanoparticles were found not active on nuclear DNA damage. The Au nanoparticles appeared nucleoprotective, but were aggressive in generating clastogenic aberrations in A. cepa root meristematic cells. Results of the antimicrobial assays show that silver nanoparticles were active against most of the tested strains, as the lowest MIC value being obtained against B. cereus (approx. 0.0015 mM).
Phyto-synthesis and antibacterial studies of bio-based silver nanoparticles using Sesbania grandiflora (Avisa) leaf tea extract

NASA Astrophysics Data System (ADS)

Mallikarjuna, K.; Balasubramanyam, K.; Narasimha, G.; Kim, Haekyoung

2018-01-01

Green nanobiotechnology using plants, micro-organisms, and their extracts has improved the utilization of natural resources. More efficient and eco-friendly routes are being developed for the creation of benign, biodegradable materials that have medical applicability. We developed silver nanoparticles encapsulated with Sesbania grandiflora (Avisa) leaf extract, which served as a reducing and capping material. The structure and functionalization of the synthesized nanoparticles were investigated using UV-vis, XRD, FE-TEM, SAED, and FTIR analyses. The nanoparticles were found to be isotropic and spherical, with a core of Ag wrapped in phytochemicals. The presence of phytochemicals stabilized the nanoparticles during production by preventing agglomeration. Antibacterial properties against both gram-positive and gram-negative bacteria were also tested. The phytochemical-wrapped silver nanoparticles were more effective antibiotics than were bare silver nanoparticles. The phytochemicals were likely responsible for both direct and indirect improvements in the bactericidal properties of the Ag particles. Additionally, the developed nanoparticles showed higher antibacterial activity towards gram-negative bacteria than towards gram-positive bacteria, with the cell wall playing an important role in adsorption and absorption of Ag+.
Comparative study of spasmolytic properties, antioxidant activity and phenolic content of Arbutus unedo from Montenegro and Greece.

PubMed

Pavlović, Dragana R; Branković, Suzana; Kovačević, Nada; Kitić, Dušanka; Veljković, Slavimir

2011-05-01

Arbutus unedo leaf is used traditionally for gastrointestinal complaints. Ethanol extracts from Arbutus unedo collected in both Montenegro (AuM) and Greece (AuG) were found to decrease the ileal basal tonus, with AuG producing a significantly higher (p < 0.05) reduction in contractile response to acetylcholine. AuM and AuG relaxed 80 mM K(+) induced contractions and shifted the Ca(++) concentration-response curves to the right, similar to that caused by verapamil, suggesting that the spasmolytic effect was induced through calcium channel inhibition. The antioxidant activity of AuM and AuG and the phenolic content of the extracts and dry plant material were studied, and both extracts were found to possess considerable antioxidant properties. AuG showed a stronger in vitro antioxidative activity in the DPPH assay and in the TBA test. Polyphenol, tannin and flavonoid levels were higher in AuG, supporting the more potent spasmolytic and antioxidative effects, whereas the arbutin content was higher in dry plant material collected in Montenegro. Copyright © 2011 John Wiley & Sons, Ltd.
Supercritical CO2 impregnation of PLA/PCL films with natural substances for bacterial growth control in food packaging.

PubMed

Milovanovic, Stoja; Hollermann, Gesa; Errenst, Cornelia; Pajnik, Jelena; Frerich, Sulamith; Kroll, Stephen; Rezwan, Kurosch; Ivanovic, Jasna

2018-05-01

Biodegradable polymers with antibacterial properties are highly desirable materials for active food packaging applications. Thymol, a dietary monoterpene phenol with a strong antibacterial activity is abundant in plants belonging to the genus Thymus. This study presents two approaches for supercritical CO 2 impregnation of poly(lactic acid)(PLA)/poly(ε-caprolactone)(PCL) blended films to induce antibacterial properties of the material: (i) a batch impregnation process for loading pure thymol, and (ii) an integrated supercritical extraction-impregnation process for isolation of thyme extract and its incorporation into the films, operated in both batch or semi-continuous modes with supercritical solution circulation. The PCL content in films, impregnation time and CO 2 flow regime were varied to maximize loading of the films with thymol or thyme extract with preserving films' structure and thermal stability. Representative film samples impregnated with thymol and thyme extract were tested against Gram (-) (Escherichia coli) and Gram(+) (Bacillus subtilis) model strains, by measuring their metabolic activity and re-cultivation after exposure to the films. The film containing thymol (35.8 wt%) showed a strong antibacterial activity leading to a total reduction of bacterial cell viability. Proposed processes enable fast, controlled and organic solvent-free fabrication of the PLA/PCL films containing natural antibacterial substances at moderately low temperature, with a compact structure and a good thermal stability, for potential use as active food packaging materials. Copyright © 2018 Elsevier Ltd. All rights reserved.
SAW parameters on Y-cut langasite structured materials.

PubMed

Puccio, Derek; Malocha, Donald C; Saldanha, Nancy; da Cunha, Mauricio Pereira

2007-09-01

This paper presents results and investigations of several new, man-made piezoelectric single crystal, Czochralski-grown substrate materials for surface acoustic waves (SAW) applications. These materials, langanite (LGN), langatate (LGT), Sr3TaGa3Si2O14 (STGS), Sr3NbGa3Si2O14 (SNGS), Ca3TaGa3Si2O14 (CTGS), and Ca3NbGa3Si2O14 (CNGS), have the same structure as langasite (LGS) and are of the same crystal class as quartz. These compounds are denser than quartz, resulting in lower phase velocities. They also have higher coupling. Unlike quartz and lithium niobate, there is no degradation of material properties below the material melting points resulting in the possibility of extreme high-temperature operation (> 1000 degrees C). This paper gives a summary of extracted SAW material parameters for various propagation angles on Y-cut substrates of the six materials. Parameters included are electromechanical coupling, phase velocity, transducer capacitance, metal strip reflectivity, and temperature coefficient of frequency. Using previously published fundamental material constants, extracted parameters are compared with predictions for LGT and LGN. In addition, power flow angle and fractional frequency curvature data are reported for propagation angles on CTGS and CNGS Y-cut substrates that exhibit temperature compensation near room temperature. Detailed descriptions of the SAW parameter extraction techniques are given. A discussion of the results is provided, including a comparison of extracted parameters and an overview of possible SAW applications.
Scratching as a Fracture Process: From Butter to Steel

NASA Astrophysics Data System (ADS)

Akono, A.-T.; Reis, P. M.; Ulm, F.-J.

2011-05-01

We present results of a hybrid experimental and theoretical investigation of the fracture scaling in scratch tests and show that scratching is a fracture dominated process. Validated for paraffin wax, cement paste, Jurassic limestone and steel, we derive a model that provides a quantitative means to relate quantities measured in scratch tests to fracture properties of materials at multiple scales. The scalability of scratching for different probes and depths opens new venues towards miniaturization of our technique, to extract fracture properties of materials at even smaller length scales.
Fused Deposition Modeling Enables the Low-Cost Fabrication of Porous, Customized-Shape Sorbents for Small-Molecule Extraction.

PubMed

Belka, Mariusz; Ulenberg, Szymon; Bączek, Tomasz

2017-04-18

Fused deposition modeling, one of the most common techniques in three-dimensional printing and additive manufacturing, has many practical applications in the fields of chemistry and pharmacy. We demonstrate that a thermoplastic elastomer-poly(vinyl alcohol) (PVA) composite material (LAY-FOMM 60), which presents porous properties after PVA removal, is useful for the extraction of small-molecule drug-like compounds from water samples. The usefulness of the proposed approach is demonstrated by the extraction of glimepiride from a water sample, followed by LC-MS analysis. The recovery was 82.24%, with a relative standard deviation of less than 5%. The proposed approach can change the way of thinking about extraction and sample preparation due to a shift to the use of sorbents with customizable size, shape, and chemical properties that do not rely on commercial suppliers.
Supercritical Carbon Dioxide Extraction of Carotenoids from Pumpkin (Cucurbita spp.): A Review

PubMed Central

Durante, Miriana; Lenucci, Marcello Salvatore; Mita, Giovanni

2014-01-01

Carotenoids are well known for their nutritional properties and health promoting effects representing attractive ingredients to develop innovative functional foods, nutraceutical and pharmaceutical preparations. Pumpkin (Cucurbita spp.) flesh has an intense yellow/orange color owing to the high level of carotenoids, mainly α-carotene, β-carotene, β-cryptoxanthin, lutein and zeaxanthin. There is considerable interest in extracting carotenoids and other bioactives from pumpkin flesh. Extraction procedures able to preserve nutritional and pharmacological properties of carotenoids are essential. Conventional extraction methods, such as organic solvent extraction (CSE), have been used to extract carotenoids from plant material for a long time. In recent years, supercritical carbon dioxide (SC-CO2) extraction has received a great deal of attention because it is a green technology suitable for the extraction of lipophylic molecules and is able to give extracts of high quality and totally free from potentially toxic chemical solvents. Here, we review the results obtained so far on SC-CO2 extraction efficiency and quali-quantitative composition of carotenoids from pumpkin flesh. In particular, we consider the effects of (1) dehydration pre-treatments; (2) extraction parameters (temperature and pressure); the use of water, ethanol and olive oil singularly or in combination as entrainers or pumpkin seeds as co-matrix. PMID:24756094
Supercritical carbon dioxide extraction of carotenoids from pumpkin (Cucurbita spp.): a review.

PubMed

Durante, Miriana; Lenucci, Marcello Salvatore; Mita, Giovanni

2014-04-21

Carotenoids are well known for their nutritional properties and health promoting effects representing attractive ingredients to develop innovative functional foods, nutraceutical and pharmaceutical preparations. Pumpkin (Cucurbita spp.) flesh has an intense yellow/orange color owing to the high level of carotenoids, mainly α-carotene, β-carotene, β-cryptoxanthin, lutein and zeaxanthin. There is considerable interest in extracting carotenoids and other bioactives from pumpkin flesh. Extraction procedures able to preserve nutritional and pharmacological properties of carotenoids are essential. Conventional extraction methods, such as organic solvent extraction (CSE), have been used to extract carotenoids from plant material for a long time. In recent years, supercritical carbon dioxide (SC-CO2) extraction has received a great deal of attention because it is a green technology suitable for the extraction of lipophylic molecules and is able to give extracts of high quality and totally free from potentially toxic chemical solvents. Here, we review the results obtained so far on SC-CO2 extraction efficiency and quali-quantitative composition of carotenoids from pumpkin flesh. In particular, we consider the effects of (1) dehydration pre-treatments; (2) extraction parameters (temperature and pressure); the use of water, ethanol and olive oil singularly or in combination as entrainers or pumpkin seeds as co-matrix.
Unique antitumor property of the Mg-Ca-Sr alloys with addition of Zn

PubMed Central

Wu, Yuanhao; He, Guanping; Zhang, Yu; Liu, Yang; Li, Mei; Wang, Xiaolan; Li, Nan; Li, Kang; Zheng, Guan; Zheng, Yufeng; Yin, Qingshui

2016-01-01

In clinical practice, tumor recurrence and metastasis after orthopedic prosthesis implantation is an intensely troublesome matter. Therefore, to develop implant materials with antitumor property is extremely necessary and meaningful. Magnesium (Mg) alloys possess superb biocompatibility, mechanical property and biodegradability in orthopedic applications. However, whether they possess antitumor property had seldom been reported. In recent years, it showed that zinc (Zn) not only promote the osteogenic activity but also exhibit good antitumor property. In our present study, Zn was selected as an alloying element for the Mg-1Ca-0.5Sr alloy to develop a multifunctional material with antitumor property. We investigated the influence of the Mg-1Ca-0.5Sr-xZn (x = 0, 2, 4, 6 wt%) alloys extracts on the proliferation rate, cell apoptosis, migration and invasion of the U2OS cell line. Our results show that Zn containing Mg alloys extracts inhibit the cell proliferation by alteration the cell cycle and inducing cell apoptosis via the activation of the mitochondria pathway. The cell migration and invasion property were also suppressed by the activation of MAPK (mitogen-activated protein kinase) pathway. Our work suggests that the Mg-1Ca-0.5Sr-6Zn alloy is expected to be a promising orthopedic implant in osteosarcoma limb-salvage surgery for avoiding tumor recurrence and metastasis. PMID:26907515
Examination of lignocellulosic fibers for chemical, thermal, and separations properties: Addressing thermo-chemical stability issues

NASA Astrophysics Data System (ADS)

Johnson, Carter David

Natural fiber-plastic composites incorporate thermoplastic resins with fibrous plant-based materials, sometimes referred to as biomass. Pine wood mill waste has been the traditional source of natural fibrous feedstock. In anticipation of a waste wood shortage other fibrous biomass materials are being investigated as potential supplements or replacements. Perennial grasses, agricultural wastes, and woody biomass are among the potential source materials. As these feedstocks share the basic chemical building blocks; cellulose, hemicellulose, and lignin, they are collectively called lignocellulosics. Initial investigation of a number of lignocellulosic materials, applied to fiber-plastic composite processing and material testing, resulted in varied results, particularly response to processing conditions. Less thermally stable lignocellulosic filler materials were physically changed in observable ways: darkened color and odor. The effect of biomass materials' chemical composition on thermal stability was investigated an experiment involving determination of the chemical composition of seven lignocellulosics: corn hull, corn stover, fescue, pine, soy hull, soy stover, and switchgrass. These materials were also evaluated for thermal stability by thermogravimetric analysis. The results of these determinations indicated that both chemical composition and pretreatment of lignocellulosic materials can have an effect on their thermal stability. A second study was performed to investigate what effect different pretreatment systems have on hybrid poplar, pine, and switchgrass. These materials were treated with hot water, ethanol, and a 2:1 benzene/ethanol mixture for extraction times of: 1, 3, 6, 12, and 24 hours. This factorial experiment demonstrated that both extraction time and medium have an effect on the weight percent of extractives removed from all three material types. The extracted materials generated in the above study were then subjected to an evaluation of thermal stability by thermogravimetric analysis in a subsequent experiment. Overlay plots, combining individual weight loss curves, demonstrate that the experimental factors, solvent system and extraction time, produce effects on the thermal stability of the treated biomass samples. These data also indicated that the individual lignocellulosic materials had unique responses to the type of solvent used for pretreatment. Increasing extraction time had either no correlation with or a positive effect on thermal stability of the biomass samples.
A method for the solvent extraction of low-boiling-point plant volatiles.

PubMed

Xu, Ning; Gruber, Margaret; Westcott, Neil; Soroka, Julie; Parkin, Isobel; Hegedus, Dwayne

2005-01-01

A new method has been developed for the extraction of volatiles from plant materials and tested on seedling tissue and mature leaves of Arabidopsis thaliana, pine needles and commercial mixtures of plant volatiles. Volatiles were extracted with n-pentane and then subjected to quick distillation at a moderate temperature. Under these conditions, compounds such as pigments, waxes and non-volatile compounds remained undistilled, while short-chain volatile compounds were distilled into a receiving flask using a high-efficiency condenser. Removal of the n-pentane and concentration of the volatiles in the receiving flask was carried out using a Vigreux column condenser prior to GC-MS. The method is ideal for the rapid extraction of low-boiling-point volatiles from small amounts of plant material, such as is required when conducting metabolic profiling or defining biological properties of volatile components from large numbers of mutant lines.
Development of deep eutectic solvents applied in extraction and separation.

PubMed

Li, Xiaoxia; Row, Kyung Ho

2016-09-01

Deep eutectic solvents, as an alternative to ionic liquids, have greener credentials than ionic liquids, and have attracted considerable attention in related chemical research. Deep eutectic solvents have attracted increasing attention in chemistry for the extraction and separation of various target compounds from natural products. This review highlights the preparation of deep eutectic solvents, unique properties of deep eutectic solvents, and synthesis of deep-eutectic-solvent-based materials. On the other hand, application in the extraction and separation of deep eutectic solvents is also included in this report. In this paper, the available data and references in this field are reviewed to summarize the applications and developments of deep eutectic solvents. Based on the development of deep eutectic solvents, an exploitation of new deep eutectic solvents and deep eutectic solvents-based materials is expected to diversify into extraction and separation. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Structural characteristics of pumpkin pectin extracted by microwave heating.

PubMed

Yoo, Sang-Ho; Lee, Byeong-Hoo; Lee, Heungsook; Lee, Suyong; Bae, In Young; Lee, Hyeon Gyu; Fishman, Marshall L; Chau, Hoa K; Savary, Brett J; Hotchkiss, Arland T

2012-11-01

To improve extraction yield of pumpkin pectin, microwave heating was adopted in this study. Using hot acid extraction, pumpkin pectin yield decreased from 5.7% to 1.0% as pH increased from pH 1.0 to 2.0. At pH 2.5, no pectin was recovered from pumpkin flesh powder. After a pretreatment at pH 1.0 and 25 °C for 1 h, pumpkin powder was microwave-extracted at 120 °C for 3 min resulting in 10.5% of pectin yield. However, premicrowave treatment at 60 °C for 20 min did not improve extraction yield. When microwave heating at 80 °C for 10 min was applied after premicrowave treatment, final pectin yield increased to 11.3%. When pH was adjusted to 2.0, the yield dropped to 7.7% under the same extraction conditions. Molecular shape and properties as well as chemical composition of pumpkin pectin were significantly affected depending on extraction methods. Galacturonic acid content (51% to 58%) of pumpkin pectin was lower than that detected in commercial acid-extracted citrus pectin, while higher content of neutral sugars and acetyl esters existed in pumpkin pectin structure. Molecular weight (M(w) ) and intrinsic viscosity (η(w) ) determined for microwave-extracted pumpkin pectins were substantially lower than acid-extracted pectin, whereas polydispersity was greater. However, microwave-extracted pectin at pH 2.0 had more than 5 times greater M(w) than did the pectin extracted at pH 1.0. The η(w) of microwave-extracted pectin produced at pH 2.0 was almost twice that of other microwave-extracted pectins, which were comparable to that of acid-extracted pectin. These results indicate that extraction yield of pumpkin pectin would be improved by microwave extraction and different pectin structure and properties can be obtained compared to acid extraction. Pumpkin is a promising alternative source for pectin material. Pumpkin pectin has a unique chemical structure and physical properties, presumably providing different functional properties compared to conventional commercial pectin sources. Depending on the conditions to produce pumpkin pectin, diverse molecular structures can be obtained and utilized in various food applications. © 2012 Institute of Food Technologists®
Effect of Extrusion on the Mechanical and Rheological Properties of a Reinforced Poly(Lactic Acid): Reprocessing and Recycling of Biobased Materials

PubMed Central

Peinado, Víctor; Castell, Pere; García, Lidia; Fernández, Ángel

2015-01-01

The aim of this research paper is to study the behaviour of a common used biopolymer (Poly(Lactic Acid) (PLA)) after several reprocesses and how two different types of additives (a melt strength enhancer and a nanoadditive) affect its mechanical and rheological properties. Systematic extraction of extrudate samples from a twin-screw compounder was done in order to study the effect in the properties of the reprocessed material. Detailed rheological tests on a capillary rheometer as well as mechanical studies on a universal tensile machine after preparation of injected specimens were carried out. Results evidenced that PLA and reinforced PLA materials can be reprocessed and recycled without a remarkable loss in their mechanical properties. Several processing restrictions and specific phenomena were identified and are explained in the present manuscript. PMID:28793622
Low-Temperature Properties of Silver

PubMed Central

Smith, David R.; Fickett, F. R.

1995-01-01

Pure silver is used extensively in the preparation of high-temperature superconductor wires, tapes, films, and other configurations in which the silver not only shields the superconducting material from the surrounding materials, but also provides a degree of flexibility and strain relief, as well as stabilization and low-resistance electrical contact. Silver is relatively expensive, but at this stage of superconductor development, its unique combination of properties seems to offer the only reasonable means of achieving usable lengths of conductor. In this role, the low-temperature physical (electrical, thermal, magnetic, optical) and mechanical properties of the silver all become important. Here we present a collection of properties data extracted from the cryogenic literature and, to the extent possible, selected for reliability. PMID:29151733
Biology Notes.

ERIC Educational Resources Information Center

School Science Review, 1982

1982-01-01

Describes laboratory procedures, demonstrations, and classroom materials, including "diet poker" (nutrition game); an experiment on enzyme characteristics; demonstrations of yeast anaerobic respiration and color preference in Calliphora larvae; method to extract eugenol from clove oil to show antibiotic properties; and Benedict's test.…
Valeriana officinalis Dry Plant Extract for Direct Compression: Preparation and Characterization

PubMed Central

Gallo, Loreana; Ramírez-Rigo, María Veronica; Piña, Juliana; Palma, Santiago; Allemandi, Daniel; Bucalá, Verónica

2012-01-01

Valeriana officinalis L. (Valerianaceae) is one of the most widely used plants for the treatment of anxiety and insomnia. Usually dry plant extracts, including V. officinalis, are hygroscopic materials with poor physico-mechanical properties that can be directly compressed. A V. officinalis dry extract with moderate hygroscocity is suitable for direct compression, and was obtained by using a simple and economical technique. The V. officinalis fluid extract was oven-dried with colloidal silicon dioxide as a drying adjuvant. The addition of colloidal silicon dioxide resulted in a dry plant extract with good physico-mechanical properties for direct compression and lower hygroscopicity than the dry extract without the carrier. The dry plant extract glass transition temperature was considerably above room temperature (about 72 °C). The colloidal silicon dioxide also produced an antiplasticizing effect, improving the powder’s physical stability. The pharmaceutical performance of the prepared V. officinalis dry extract was studied through the design of tablets. The manufactured tablets showed good compactability, friability, hardness, and disintegration time. Those containing a disintegrant (Avicel PH 101) exhibited the best pharmaceutical performance, having the lowest disintegration time of around 40 seconds. PMID:23264947
Perspective: Materials Informatics and Big Data: Realization of the Fourth Paradigm of Science in Materials Science

DTIC Science & Technology

2016-08-17

thereby opening up new avenues for accelerated materials discovery and design . The need for such data analytics has also been emphasized by the...and design . The construction of inverse models is typically formulated as an optimiza- tion problem wherein a property or performance metric of...discovery and design . extraction, feature selection, etc. Such data preprocessing can either be supervised or unsupervised, based on whether the
Extraction and Characterization of Boswellia Serrata Gum as Pharmaceutical Excipient.

PubMed

Panta, Sumedha; Malviya, Rishabha; Sharma, Pramod

2015-01-01

This manuscript deals with the purification and characterization of Boswellia serrata gum as a suspending agent. The Boswellia serrata gum was purchased as crude material, purified and further characterized in terms of organoleptic properties and further micromeritic studies were carried out to characterize the polymer as a pharmaceutical excipient. The suspending properties of the polymer were also evaluated. The results showed that the extracted gum possesses optimum organoleptic as well as micromeritic and suspending properties. To characterize Boswellia serrata gum as a natural excipient. Boswellia serrata gum, paracetamol, distilled water. The results showed that the extracted gum possesses optimum organoleptic as well as micromeritic and suspending properties. It is concluded from the research work that the gum extracted from Boswellia serrata shows the presence of carbohydrates after chemical tests. All the organoleptic properties evaluated were found to be acceptable. The pH was found to be slightly acidic. Swelling Index reveals that the gum swells well in water. Total ash value was within the limits. The values of angle of repose and Carr's Index of powdered gum powder showed that the flow property was good. IR spectra confirmed the presence of alcohol, amines, ketones, anhydrides and aromatic rings. The suspending properties of Boswellia serrata gum were found to be higher as compared to gum acacia while the flow rate of Boswellia serrata gum (1% suspension) was less than gum acacia (1% suspension). The viscosity measurement of both Boswellia serrata gum suspension and gum acacia suspension showed approximately similar results.
Possible artifacts in inferring seismic properties from X-ray data

NASA Astrophysics Data System (ADS)

Bosak, A.; Krisch, M.; Chumakov, A.; Abrikosov, I. A.; Dubrovinsky, L.

2016-11-01

We consider the experimental and computational artifacts relevant for the extraction of aggregate elastic properties of polycrystalline materials with particular emphasis on the derivation of seismic velocities. We use the case of iron as an example, and show that the improper use of definitions and neglecting the crystalline anisotropy can result in unexpectedly large errors up to a few percent.
Utilization of tartary buckwheat bran as a source of rutin and its effect on the rheological and antioxidant properties of wheat-based products

USDA-ARS?s Scientific Manuscript database

Tartary buckwheat bran, a by-product of buckwheat flour production was utilized as a source of rutin, and the extracted rutin-enriched material (REM) was used to fortify wheat-based foods of which rheological and antioxidant properties were characterized. REM contained a high content of rutin (29.6 ...
Using Microwaves for Extracting Water from the Moon

NASA Technical Reports Server (NTRS)

Ethridge, Edwin C.

2009-01-01

Twenty years ago, the Lunar Prospector remote sensing satellite provided evidence of relatively large hydrogen concentrations at the lunar poles and in particular concentrated in permanently shadowed craters. The scientific hypothesis is that the hydrogen is in the form of cryo-trapped water just under the surface of the soil. If true this would mean that an average of about 2% water ice is mixed with the lunar soil existing in the form of ice at cryogenic temperatures. For 5 years we have been investigating the use of microwaves for the processing of lunar soil. One of the early uses could be to use microwave energy to extract volatiles and in particular water from the lunar permafrost. Prototype experiments have shown that microwave energy at 2.45 GHz, as in consumer microwave ovens, will couple with and heat cryogenically cooled lunar soil permafrost simulant, resulting in the rapid sublimation of water vapor into the vacuum chamber. The water vapor has been collected on a cryogenic cold trap with high efficiency. The primary advantage of microwave processing is that the volatiles can be extracted in situ. Excavation would not be required. Microwave frequency dielectric property measurements are being made of different lunar soil simulants and plans are to measure Apollo lunar soil at different frequencies and over a range of temperatures. The materials properties are being used to evaluate the heating of lunar soil and develop COMSOL models that can be used to evaluate different microwave extraction scenarios. With COMSOL the heating from cryogenic temperatures can be calculated and COMSOL will permit temperature dependent materials properties to be used during the heating process. Calculations at different microwave frequencies will allow the evaluation of the type of hardware that would be needed to most efficiently extract the water and other volatiles.
Ultrasonic extraction of pectin from Opuntia ficus indica cladodes after mucilage removal: Optimization of experimental conditions and evaluation of chemical and functional properties.

PubMed

Bayar, Nadia; Bouallegue, Tahani; Achour, Mabrouka; Kriaa, Mouna; Bougatef, Ali; Kammoun, Radhouane

2017-11-15

Ultrasonic assisted extraction (UAE) of pectin from Opuntia ficus indica (OFI) cladodes after mucilage removal was attempted using the response surface methodology. The process variables were optimized by the isovariant central composite design in order to improve the pectin extraction yield. The optimum condition obtained was: sonication time 70min, temperature 70°C, pH 1.5 and the water-material ratio 30ml/g. This condition was validated and the performance of experimental extraction was 18.14%±1.41%, which was closely linked to the predicted value (19.06%). Thus, UAE present a promising alternative to conventional extraction process thanks to its high efficiency which was achieved in less time and at lower temperatures. The pectin extracted by UAE from OFI cladodes (UAEPC) has a low degree of esterification, high uronic acid content, important functional properties and good anti-radical activity. These results are in favor of the use of UAEPC as potential additive in food industry. Copyright © 2017. Published by Elsevier Ltd.
Biological Properties of Fucoxanthin in Oil Recovered from Two Brown Seaweeds Using Supercritical CO2 Extraction

PubMed Central

Periaswamy Sivagnanam, Saravana; Yin, Shipeng; Choi, Jae Hyung; Park, Yong Beom; Woo, Hee Chul; Chun, Byung Soo

2015-01-01

The bioactive materials in brown seaweeds hold great interest for developing new drugs and healthy foods. The oil content in brown seaweeds (Saccharina japonica and Sargassum horneri) was extracted by using environmentally friendly supercritical CO2 (SC-CO2) with ethanol as a co-solvent in a semi-batch flow extraction process and compared the results with a conventional extraction process using hexane, ethanol, and acetone mixed with methanol (1:1, v/v). The SC-CO2 method was used at a temperature of 45 °C and pressure of 250 bar. The flow rate of CO2 (27 g/min) was constant for the entire extraction period of 2 h. The obtained oil from the brown seaweeds was analyzed to determine their valuable compounds such as fatty acids, phenolic compounds, fucoxanthin and biological properties including antioxidant, antimicrobial, and antihypertension effects. The amounts of fucoxanthin extracted from the SC-CO2 oils of S. japonica and S. horneri were 0.41 ± 0.05 and 0.77 ± 0.07 mg/g, respectively. High antihypertensive activity was detected when using mixed acetone and methanol, whereas the phenolic content and antioxidant property were higher in the oil extracted by SC-CO2. The acetone–methanol mix extracts exhibited better antimicrobial activities than those obtained by other means. Thus, the SC-CO2 extraction process appears to be a good method for obtaining valuable compounds from both brown seaweeds, and showed stronger biological activity than that obtained by the conventional extraction process. PMID:26035021
Biological Properties of Fucoxanthin in Oil Recovered from Two Brown Seaweeds Using Supercritical CO2 Extraction.

PubMed

Sivagnanam, Saravana Periaswamy; Yin, Shipeng; Choi, Jae Hyung; Park, Yong Beom; Woo, Hee Chul; Chun, Byung Soo

2015-05-29

The bioactive materials in brown seaweeds hold great interest for developing new drugs and healthy foods. The oil content in brown seaweeds (Saccharina japonica and Sargassum horneri) was extracted by using environmentally friendly supercritical CO2 (SC-CO2) with ethanol as a co-solvent in a semi-batch flow extraction process and compared the results with a conventional extraction process using hexane, ethanol, and acetone mixed with methanol (1:1, v/v). The SC-CO2 method was used at a temperature of 45 °C and pressure of 250 bar. The flow rate of CO2 (27 g/min) was constant for the entire extraction period of 2 h. The obtained oil from the brown seaweeds was analyzed to determine their valuable compounds such as fatty acids, phenolic compounds, fucoxanthin and biological properties including antioxidant, antimicrobial, and antihypertension effects. The amounts of fucoxanthin extracted from the SC-CO2 oils of S. japonica and S. horneri were 0.41 ± 0.05 and 0.77 ± 0.07 mg/g, respectively. High antihypertensive activity was detected when using mixed acetone and methanol, whereas the phenolic content and antioxidant property were higher in the oil extracted by SC-CO2. The acetone-methanol mix extracts exhibited better antimicrobial activities than those obtained by other means. Thus, the SC-CO2 extraction process appears to be a good method for obtaining valuable compounds from both brown seaweeds, and showed stronger biological activity than that obtained by the conventional extraction process.
Volume imaging NDE and serial sectioning of carbon fiber composites

NASA Astrophysics Data System (ADS)

Hakim, Issa; Schumacher, David; Sundar, Veeraraghavan; Donaldson, Steven; Creuz, Aline; Schneider, Rainer; Keller, Juergen; Browning, Charles; May, Daniel; Ras, Mohamad Abo; Meyendorf, Norbert

2018-04-01

A composite material is a combination of two or more materials with very different mechanical, thermal and electrical properties. The various forms of composite materials, due to their high material properties, are widely used as structural materials in the aviation, space, marine, automobile, and sports industries. However, some defects like voids, delamination, or inhomogeneous fiber distribution that form during the fabricating processes of composites can seriously affect the mechanical properties of the composite material. In this study, several imaging NDE techniques such as: thermography, high frequency eddy current, ultrasonic, x-ray radiography, x-ray laminography, and high resolution x-ray CT were conducted to characterize the microstructure of carbon fiber composites. Then, a 3D analysis was implemented by the destructive technique of serial sectioning for the same sample tested by the NDE methods. To better analyze the results of this work and extract a clear volume image for all features and defects contained in the composite material, an intensive comparison was conducted among hundreds of 3D-NDE and multi serial sections' scan images showing the microstructure variation.
Leaching kinetics of cobalt from the scraps of spent aerospace magnetic materials.

PubMed

Zhou, Xuejiao; Chen, Yongli; Yin, Jianguo; Xia, Wentang; Yuan, Xiaoli; Xiang, Xiaoyan

2018-06-01

Based on physicochemical properties of the scraps of spent aerospace magnetic materials, a roasting - magnetic separation followed by sulfuric acid leaching process was proposed to extract cobalt. Roasting was performed at 500 °C to remove organic impurity. Non-magnetic impurities were reduced by magnetic separation and then the raw material was sieved into desired particle sizes. Acid leaching was carried out to extract cobalt from the scraps and experimental parameters included agitation speed, particle size, initial concentration of sulfuric acid and temperature. Agitation speed higher than 300 r/min had a relatively small impact on the cobalt extraction. As the particle size reduced, the content of cobalt in the raw material decreases and the extraction of cobalt by acid leaching increased at first and decreased afterwards. Raising the initial concentration of sulfuric acid and temperature contributed to improve the cobalt extraction and the influence of temperature was more remarkable. SEM image revealed that the spent aerospace magnetic materials mainly existed in the sliced strip flake with a loose surface and porous structure. Under the experimental condition, the leaching rate of cobalt from the scraps in sulfuric acid solution could be expressed as ln(-ln(1 - α)) = lnk + nlnt. The apparent activation energy was found to be 38.33 kJ/mol and it was mainly controlled by the surface chemical reaction. Copyright © 2018 Elsevier Ltd. All rights reserved.
Polyphenol content and antioxidant properties of colored soybean seeds from central Europe.

PubMed

Malenčić, Djordje; Cvejić, Jelena; Miladinović, Jegor

2012-01-01

The antioxidant activity and contents of various polyphenol classes in the seeds of seven soybean varieties of different seed color and one yellow seed cultivar, representing a reference genotype, were evaluated. Total polyphenols and tannins were determined after extraction of plant material with 70% aqueous acetone, and total flavonoids were extracted with methanol and acetic acid, whereas anthocyanins were extracted with 20% aqueous ethanol. In addition, isoflavone content and composition were determined using high-performance liquid chromatography analysis. Antioxidant activity of seed extracts was evaluated by the 2,2-diphenyl-1-picrylhydrazyl free radical scavenging activity assay. A positive linear correlation between antioxidant activity and contents of total polyphenols and anthocyanins was established. The highest antioxidant activity was observed in the extracts of black and brown varieties, which also showed high levels of all polyphenol classes examined. Yellow seed had the highest total isoflavone content (3.62 mg/g of dry material). The highest concentration of total daidzein was determined in black seeds (>2.0 mg/g of dry material), and the highest total glycitein and genistein contents occurred in the yellow cultivar (0.53 and 1.49 mg/g of dry material, respectively). According to our results, varieties of black and brown seeds could be of special interest not only for their large content of total polyphenols, ranging from 4.94 to 6.22 mg of gallic acid equivalents/g of dry material, but also for their high content of natural antioxidants such as anthocyanins.
Evaluation of Antioxidant Activity and Growth Control Properties of Nonoscale Structure Produced from Aloe vera var. littoralis Extract on Clinical Isolates of Salmonella.

PubMed

Ranjbar, Reza; Arjomandzadegan, Mohammad; Hosseiny, Hossein

2017-07-31

The aim of the study was to examine antibacterial properties of microemulsion structure produced from Aloe vera var. littoralis extract as a new tool of nanoscale drug-like materials. Aloe vera var. littoralis ( A. littoralis ) extract was prepared by distillation method. A nonocarrier structure in the microemulsion system was prepared from the extract. Serial concentrations were prepared from 8 mg/mL extract and the nonocarrier containing 0.1 mg/mL pure extract and were evaluated by a disk diffusion method for 35 Salmonella clinical isolates. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined by microbroth dilution assay using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) method by an enzyme-linked immunosorbent assay(ELISA) Microplate Reader apparatus. Antioxidant activity of the extract was determined by measuring the ferric reducing ability of plasma (FRAP) assay. From 35 clinical isolates of Salmonella , 17 isolates-including resistant isolates of S.E.1103 and S.E.49-had a zone of inhibition (ZI) of 7 to 32 mm in 0.007 mg/mL of the extract. S.E.76 isolate exposed to 30 µg/mL ceftazidime disk had a ZI of 12 mm but had 10 mm in 7µg/mL of A. littoralis extract. The inhibitory effect of a nanocarrier at a concentration of 25 µg/mL by 20 mm ZI was comparable by the ceftazidime (30 µg/mL) effect. MIC 50 was 0.25 mg/mL and MBC 50 was 0.5 mg/mL by MTT method for the extract. It was shown that A.littoralis extract had antioxidant activity of 31.67 µM/mg that could be increased based on concentration. It was concluded that the nanocarrier had a significant effect on the studied isolates in comparison with ordinary antibiotics and had potential for use as a natural antioxidant and antimicrobial material in complementary medicine.
On the mechanical properties of tooth enamel under spherical indentation.

PubMed

Chai, Herzl

2014-11-01

The mechanical properties of tooth enamel generally exhibit large variations, which reflect its structural and material complexity. Some key properties were evaluated under localized contact, simulating actual functioning conditions. Prominent cusps of extracted human molar teeth were polished down ~0.7 mm below the cusp tip and indented by tungsten carbide balls. The internal damage was assessed after unloading from longitudinal or transverse sections. The ultimate tensile stress (UTS) was determined using a novel bilayer specimen. The damage is characterized by penny-like radial cracks driven by hoop stresses and cylindrical cracks driven along protein-rich interrod materials by shear stresses. Shallow cone cracks typical of homogeneous materials which may cause rapid tooth wear under repeat contact are thus avoided. The mean stress vs. indentation strain curve is highly nonlinear, attributable to plastic shearing of protein between and within enamel rods. This curve is also affected by damage, especially radial cracks, the onset of which depends on ball radius. Several material properties were extracted from the tests, including shear strain at the onset of ring cracks γ(F) (=0.14), UTS (=119 MPa), toughness K(C) (=0.94 MPa m(1/2)), a crack propagation law and a constitutive response determined by trial and error with the aid of a finite-element analysis. These quantities, which are only slightly sensitive to anatomical location within the enamel region tested, facilitate a quantitative assessment of crown failure. Causes for variations in published UTS and K(C) values are discussed. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
Enhancement of white light OLED efficiency by combining both internal and external light extraction structures

NASA Astrophysics Data System (ADS)

Kao, I.-Ling; Ku, Chun-Neng; Chen, Yi-Ping; Lin, Ding-Zheng

2012-09-01

We proposed an internal nanostructure with a high reflective index planarization layer to solve the optical loss due to the reflective index mismatch between ITO and glass substrate. In our experiments, we found the electrical property of OLED device was significantly influenced by the internal nanostructures without planarization layer. Moreover, the internal extraction structure (IES) is not necessarily beneficial for light extraction. Therefore, we proposed a new substrate combine both internal and external extraction structure (EES) to extract trapping light. We successfully developed a high refractive index (N 1.7) planarization material with flat surface (RMS roughness < 2 nm), and improved about 70% device efficiency compared to traditional glass substrate.
Extraction Optimization, Purification and Physicochemical Properties of Polysaccharides from Gynura medica.

PubMed

Li, Fengwei; Gao, Jian; Xue, Feng; Yu, Xiaohong; Shao, Tao

2016-03-23

Extraction of polysaccharides from Gynura medica (GMPs) was optimized by response surface methodology (RSM). A central composition design including three parameters, namely extraction temperature (X₁), ratio of water to raw material (X₂) and extraction time (X₃), was used. The best conditions were extraction temperature of 91.7 °C, extraction time of 4.06 h and ratio of water to raw material of 29.1 mL/g. Under the optimized conditions, the yield of GMPs was 5.56%, which was similar to the predicted polysaccharides yield of 5.66%. A fraction named GMP-1 was obtained after isolation and purification by DEAE-52 and Sephadex G-100 gel chromatography, respectively. GMP-1, with a molecular weight of 401 kDa, mainly consisted of galacturonic acid (GalA), xylose (Xyl), glucose (Glu). Infrared spectroscopy was used to characterize the major functional groups of GMP-1 and the results indicated that it was an acidic polysaccharide. The antioxidant and α-glucosidase inhibitory activities of GMPs and GMP-1 were determined in vitro. The results indicated that GMPs and GMP-1 show potential for use in functional foods or medicines.

Pyrochars and hydrochars differently alter the sorption of the herbicide isoproturon in an agricultural soil.

PubMed

Eibisch, Nina; Schroll, Reiner; Fuß, Roland; Mikutta, Robert; Helfrich, Mirjam; Flessa, Heinz

2015-01-01

Carbonaceous material from pyrolysis (pyrochars) and hydrothermal carbonization (hydrochars) are applied to soil to improve soil fertility and carbon sequestration. As a positive side effect, the mobility of pesticides and the risk of groundwater contamination can be minimized. However, the impact of various raw materials on the sorption capacity of different pyrochars and hydrochars is poorly understood. Thus, sorption experiments were performed with (14)C-labeled isoproturon (IPU, 0.75 kg ha(-1)) in a loamy sand soil amended with either pyrochar or hydrochar (0.5% and 5% dry weight, respectively). Carbonaceous materials were produced from three different raw materials: corn digestate, miscanthus, woodchips of willow and poplar. After 72 h of incubation, a sequential extraction procedure was conducted to quantify in situ IPU bioavailability, total amount of extractable IPU, and non-extractable pesticide residues (NER). Added char amount, carbonization type, and raw materials had statistically significant effects on the sorption of IPU. The amount of in situ available IPU was reduced by a factor of 10-2283 in treatments with pyrochar and by a factor of 3-13 in hydrochar treatments. The surface area of the charred material was the most predictive variable of IPU sorption to char amended soil. Some physical and chemical char properties tend to correlate with pore water-, methanol- or non-extractable IPU amounts. Due to a low micro-porosity and ash content, high water extractable carbon contents and O-functional groups of hydrochars, the proportion of NER in hydrochar amended soils was considerably lower than in soil amended with pyrochars. Copyright © 2014 Elsevier Ltd. All rights reserved.
Evaluation, prediction and optimization the ultrasound-assisted extraction method using response surface methodology: antioxidant and biological properties of Stachys parviflora L.

PubMed Central

Bashi, Davoud Salar; Dowom, Samaneh Attaran; Bazzaz, Bibi Sedigheh Fazly; Khanzadeh, Farhad; Soheili, Vahid; Mohammadpour, Ali

2016-01-01

Objective(s): To optimize the extraction method using response surface methodology, extract the phenolic compounds, and identify the antioxidant and biological properties of Stachys parviflora L. extracts. Materials and Methods: Maceration and ultrasound-assisted extraction (UAE) (4, 7, 10 min treatment time, 40, 70, 100 % high-intensity and 60, 80, 100 % (v v-1) methanol purity) were applied to obtain the extracts. SEM was conducted to provide the microstructure of the extracted plant. MICs (colorimetric assay), MFCs (colony diameter), total phenolic content, total flavonoid content, radical scavenging capacity and extraction efficiency were determined. HPLC analysis was applied to measure the existent phenolic compounds. Results: A quadratic model (4 min treatment time, 74.5 % high-intensity and 74.2 % solvent purity) was suggested as the best (TPC: 20.89 mg GAE g-1 d.m., TFC: 6.22 mg QEs g-1 d.m., DPPH IC50: 21.86 µg ml-1 and EE: 113.65 mg g-1 d.m.) UAE extraction model. The optimized UAE extract was generally more effective against Gram-positive microorganisms (MIC: 10-20; MBC: 10-40 (mg ml-1)) than Gram-negative ones (MIC: 40; MBC: >40 (mg ml-1)). Moreover, it (MGI: 2.32-100 %) revealed more anti-mold activity than maceration (MGI: <28.77 %). Explosive disruption of the cell walls, therefore, enhanced extraction yield by acoustic cavitation, was elucidated using SEM. Caffeic acid, tannic acid, quercetin, trans ferulic acid and rosmarinic acid were determined as the phenolic compounds in the optimized extract. Conclusion: RSM optimization was successfully applied for UAE from S. parviflora. The considerable antioxidant and biological properties were attributed to the phenolic compounds. PMID:27403260
The properties of chitosan and gelatin films incorporated with ethanolic red grape seed extract and Ziziphora clinopodioides essential oil as biodegradable materials for active food packaging.

PubMed

Shahbazi, Yasser

2017-06-01

The aim of this study was to improve different characteristics including antibacterial, antioxidant, physical and mechanical properties of chitosan (Ch) and gelatin (Ge) films by incorporating Ziziphora clinopodioides essential oil (ZEO; 0 and 1% v/w) and ethanolic grape seed extract (GSE; 0 and 1% v/w). The main compounds of the ZEO were carvacrol (65.22%) and thymol (19.51%). According to our findings, addition of aforementioned materials could improve total phenolic content, antibacterial and antioxidant activities, thickness and also water vapor barrier property. ZEO and GSE reduces swelling index, tensile strength, puncture force and puncture deformation of Ch and Ge films. Pure Ch and Ge films had slightly yellow and white appearances, respectively, while films incorporated with GSE in combination with ZEO had grey appearances. This study indicated the some benefits of addition of ZEO and GSE into Ch and Ge films and their potentials for application as biodegradable active packaging. Copyright © 2017 Elsevier B.V. All rights reserved.
Supercritical Nitrogen Processing for the Purification of Reactive Porous Materials

PubMed Central

Stadie, Nicholas P.; Callini, Elsa; Mauron, Philippe; Borgschulte, Andreas; Züttel, Andreas

2015-01-01

Supercritical fluid extraction and drying methods are well established in numerous applications for the synthesis and processing of porous materials. Herein, nitrogen is presented as a novel supercritical drying fluid for specialized applications such as in the processing of reactive porous materials, where carbon dioxide and other fluids are not appropriate due to their higher chemical reactivity. Nitrogen exhibits similar physical properties in the near-critical region of its phase diagram as compared to carbon dioxide: a widely tunable density up to ~1 g ml-1, modest critical pressure (3.4 MPa), and small molecular diameter of ~3.6 Å. The key to achieving a high solvation power of nitrogen is to apply a processing temperature in the range of 80-150 K, where the density of nitrogen is an order of magnitude higher than at similar pressures near ambient temperature. The detailed solvation properties of nitrogen, and especially its selectivity, across a wide range of common target species of extraction still require further investigation. Herein we describe a protocol for the supercritical nitrogen processing of porous magnesium borohydride. PMID:26066492
The Novelty in Fabrication of Poly Vinyl Alcohol/κ-Carrageenan Hydrogel with Lactobacillus bulgaricus Extract as Anti-inflammatory Wound Dressing Agent.

PubMed

El-Fawal, Gomaa F; Yassin, Abdelrahman M; El-Deeb, Nehal M

2017-07-01

Material barrier properties to microbes are an important issue in many pharmaceutical applications like wound dressings. A wide range of biomaterials has been used to manage the chronic inflamed wounds. Eight hydrogel membranes of poly vinyl alcohol (PVA) with κ-carrageenan (KC) and Lactobacillus bulgaricus extract (LAB) have been prepared by using freeze-thawing technique. To evaluate the membranes efficiency as wound dressing agents, various tests have been done like gel fraction, swelling behavior, mechanical properties, etc. The antibacterial activities of the prepared membranes were tested against the antibiotic-resistant bacterial isolates. In addition, the safety usage of the prepared hydrogel was checked on human dermal fibroblast cells. The anti-inflammatory properties of the prepared hydrogel on LPS-PBMC cell inflammatory model were quantified using enzyme-linked immunosorbent assay (ELISA) and real-time polymerase chain reaction (RT-qPCR). The analysis data of TGA, SEM, gel fraction, and swelling behavior showed changes in properties of prepared PVA\\KC\\LAB hydrogel membrane than pure PVA hydrogel membrane. The antibacterial activities of the prepared membranes augmented in LAB extract-prepared membranes. Out of the eight used hydrogel membranes, the PVAKC4 hydrogel membrane is the safest one on fibroblast cellular proliferation with a maximum proliferation percentage 97.3%. Also, all the used hydrogel membrane showed abilities to reduce the concentration of IL-2 and IL-8 compared with both negative and positive control. In addition, almost all the prepared hydrogel membrane showed variable abilities to downregulate the expression of TNF-α gene with superior effect of hydrogel membrane KC1. PVA/KC/LAB extract hydrogel membrane may be a promising material for wound dressing application and could accelerate the healing process of the chronic wound because of its antimicrobial and anti-inflammatory properties.
Strain Rate and Anisotropic Microstructure Dependent Mechanical Behaviors of Silkworm Cocoon Shells

PubMed Central

Xu, Jun; Zhang, Wen; Gao, Xiang; Meng, Wanlin; Guan, Juan

2016-01-01

Silkworm cocoons are multi-layered composite structures comprised of high strength silk fiber and sericin, and their mechanical properties have been naturally selected to protect pupas during metamorphosis from various types of external attacks. The present study attempts to gain a comprehensive understanding of the mechanical properties of cocoon shell materials from wild silkworm species Antheraea pernyi under dynamic loading rates. Five dynamic strain rates from 0.00625 s-1 to 12.5 s-1 are tested to show the strain rate sensitivity of the cocoon shell material. In the meantime, the anisotropy of the cocoon shell is considered and the cocoon shell specimens are cut along 0°, 45° and 90° orientation to the short axis of cocoons. Typical mechanical properties including Young’s modulus, yield strength, ultimate strength and ultimate strain are extracted and analyzed from the stress-strain curves. Furthermore, the fracture morphologies of the cocoon shell specimens are observed under scanning electron microscopy to help understand the relationship between the mechanical properties and the microstructures of the cocoon material. A discussion on the dynamic strain rate effect on the mechanical properties of cocoon shell material is followed by fitting our experimental results to two previous models, and the effect could be well explained. We also compare natural and dried cocoon materials for the dynamic strain rate effect and interestingly the dried cocoon shells show better overall mechanical properties. This study provides a different perspective on the mechanical properties of cocoon material as a composite material, and provides some insight for bio-inspired engineering materials. PMID:26939063
Polyphenolic content, antiradical activity, stability and microbiological quality of elderberry (Sambucus nigra L.) extracts.

PubMed

Pliszka, Barbara

2017-01-01

The pharmaceutical and food industries expect detailed knowledge on the physicochemical properties of elderberry fruit extracts, their stability and microbiological quality, as well as the polyphenol content in elderberry cultivars. The characteristics of the extracts might be additionally modified by citric acid, which improves the stability of anthocyanins and protects processed fruits and syrups from pathogenic microorganisms. The choice of the method with citric acid was a consequence of the physicochemical charac teristics of elderberry pigments, which are not stable under the effect of light in alcoholic solutions. The aim of study was to analyze the properties of elderberry fruit extracts regarding polyphenol content and antiradical activity, as well as their stability and microbiological quality. The plant material consisted of fruit from four cultivars (Alleso, Korsor, Sampo, Samyl) of black elderberry (Sambucus nigra L.). The following were determined in fruit extracts: polyphe- nolic content (HPLC), antiradical activity (ABTS and DPPH) and stability and microbiological quality. The HPLC analysis of polyphenols demonstrated that the extracts from fruits collected from cv. Samyl had the highest 3-sambubioside cyanidin content and those from cv. Korsor contained the highest quantity of 3-glucoside cyanidin. The extracts from cv. Sampo fruit had a dominant 3-sambubioside-5-gluco- side cyanidin and 3,5-diglucoside cyanidin content. The highest quercetin (5.92 mg 100 mg-1 of extract) and caffeic acid (1.21 mg 100 mg-1 of extract) content was found in fruit extracts from cv. Alleso. The cultivars Samyl and Korsor had a higher level of anthocyanins and higher antiradical activity (ABTS) in fruit extracts than cv. Alleso and Sampo. The antiradical activity (DPPH) of fruit extracts from elderberry cultivars as- sessed in this research was similar. The degradation index for all fruit extracts was similar (DI = 1.035). The microbiological species detected in extracts were classified as moulds (Penicillum sp., Aspergillus sp.) and yeasts (Rhodotorula sp., Torulopsis sp., Trichosporon sp., Saccharomyces sp.). The research findings may support the selection of certain cultivars for industrial applications. The high stability of anthocyanins and low level of microbiological impurities in elderberry extracts ensure the high quality of such a raw material in food and pharmaceutical processing.
A novel high-strength and highly corrosive biodegradable Fe-Pd alloy: Structural, mechanical and in vitro corrosion and cytotoxicity study.

PubMed

Čapek, Jaroslav; Msallamová, Šárka; Jablonská, Eva; Lipov, Jan; Vojtěch, Dalibor

2017-10-01

Recently, iron-based materials have been considered as candidates for the fabrication of biodegradable load-bearing implants. Alloying with palladium has been found to be a suitable approach to enhance the insufficient corrosion rate of iron-based alloys. In this work, we have extensively compared the microstructure, the mechanical and corrosion properties, and the cytotoxicity of an FePd2 (wt%) alloy prepared by three different routes - casting, mechanical alloying and spark plasma sintering (SPS), and mechanical alloying and the space holder technique (SHT). The properties of the FePd2 (wt%) were compared with pure Fe prepared in the same processes. The preparation route significantly influenced the material properties. Materials prepared by SPS possessed the highest values of mechanical properties (CYS~750-850MPa) and higher corrosion rates than the casted materials. Materials prepared by SHT contained approximately 60% porosity; therefore, their mechanical properties reached the lowest values, and they had the highest corrosion rates, approximately 0.7-1.2mm/a. Highly porous FePd2 was tested in vitro according to the ISO 10993-5 standard using L929 cells, and two-fold diluted extracts showed acceptable cytocompatibility. In general, alloying with Pd enhanced both mechanical properties and corrosion rates and did not decrease the cytocompatibility of the studied materials. Copyright © 2017 Elsevier B.V. All rights reserved.
Turning the volume down on heavy metals using tuned diatomite. A review of diatomite and modified diatomite for the extraction of heavy metals from water.

PubMed

Danil de Namor, Angela F; El Gamouz, Abdelaziz; Frangie, Sofia; Martinez, Vanina; Valiente, Liliana; Webb, Oliver A

2012-11-30

Contamination of water by heavy metals is a global problem, to which an inexpensive and simple solution is required. Within this context the unique properties of diatomite and its abundance in many regions of the world have led to the current widespread interest in this material for water purification purposes. Defined sections on articles published on the use of raw and modified diatomite for the removal of heavy metal pollutants from water are critically reviewed. The capability of the materials as extracting agents for individual species and mixtures of heavy metals are considered in terms of the kinetics, the thermodynamics and the recyclability for both, the pollutant and the extracting material. The concept of 'selectivity' for the enrichment of naturally occurring materials such as diatomite through the introduction of suitable functionalities in their structure to target a given pollutant is emphasised. Suggestions for further research in this area are given. Copyright © 2012 Elsevier B.V. All rights reserved.
Micelle-mediated extraction of elderberry blossom by whey protein and naturally derived surfactants.

PubMed

Śliwa, Karolina; Tomaszkiewicz-Potępa, Anna; Sikora, Elżbieta; Ogonowski, Jan

2013-01-01

Classical methods of the extraction of active ingredients from the plant material are expensive, complicated and often environmentally unfriendly. The micelle-mediated extraction method (MME) seems to be a good alternative. In this work, extractions of elderberry blossoms (Flos Sambuci) were performed using MME methods. Several popular surfactants and whey protein concentrate (WPC) was applied in the process. The obtained results were compared with those obtained in extraction by means of water. Antioxidant properties of the extracts were analyzed by using two different methods: reaction with di(phenyl)-(2,4,6-trinitrophenyl)iminoazanium (DPPH) reagent and Follin's method. Furthermore, the flavonoid content in the extracts was determined. The results confirmed that the MME method with using whey protein might be an alternative method for obtaining, rich in natural antioxidants, plant extracts.
Obtaining a Dry Extract from the Mikania laevigata Leaves with Potential for Antiulcer Activity

PubMed Central

Pinto, Mariana Viana; Oliveira, Ezequiane Machado; Martins, Jose Luiz Rodrigues; de Paula, Jose Realino; Costa, Elson Alves; da Conceição, Edemilson Cardoso; Bara, Maria Teresa Freitas

2017-01-01

Background: Mikania laevigata leaves are commonly used in Brazil as a medicinal plant. Objective: To obtain hydroalcoholic dried extract by nebulization and evaluate its antiulcerogenic potential. Materials and Methods: Plant material and hydroalcoholic extract were processed and analyzed for their physicochemical characteristics. A method using HPLC was validated to quantify coumarin and o-coumaric acid. Hydroalcoholic extract was spray dried and the powder obtained was characterized in terms of its physicochemical parameters and potential for antiulcerogenic activity. Results: The analytical method proved to be selective, linear, precise, accurate, sensitive, and robust. M. laevigata spray dried extract was obtained using colloidal silicon dioxide as adjuvant and was shown to possess 1.83 ± 0.004% coumarin and 0.80 ± 0.012% o-coumaric acid. It showed significant antiulcer activity in a model of an indomethacin-induced gastric lesion in mice and also produced a gastroprotective effect. Conclusion: This dried extract from M. laevigata could be a promising intermediate phytopharmaceutical product. SUMMARY Research and development of standardized dried extract of Mikania laevigata leaves obtained through spray drying and the production process was monitored by the chemical profile, physicochemical properties and potential for anti-ulcerogenic activity. Abbreviations used: DE: M. laevigata spray dried extract, HE: hydroalcoholic extract. PMID:28216886
Measurements of Acoustic Properties of Porous and Granular Materials and Application to Vibration Control

NASA Technical Reports Server (NTRS)

Park, Junhong; Palumbo, Daniel L.

2004-01-01

For application of porous and granular materials to vibro-acoustic controls, a finite dynamic strength of the solid component (frame) is an important design factor. The primary goal of this study was to investigate structural vibration damping through this frame wave propagation for various poroelastic materials. A measurement method to investigate the vibration characteristics of the frame was proposed. The measured properties were found to follow closely the characteristics of the viscoelastic materials - the dynamic modulus increased with frequency and the degree of the frequency dependence was determined by its loss factor. The dynamic stiffness of hollow cylindrical beams containing porous and granular materials as damping treatment was measured also. The data were used to extract the damping materials characteristics using the Rayleigh-Ritz method. The results suggested that the acoustic structure interaction between the frame and the structure enhances the dissipation of the vibration energy significantly.
Cellulose extraction from orange peel using sulfite digestion reagents.

PubMed

Bicu, Ioan; Mustata, Fanica

2011-11-01

Orange peel (OP) was used as raw material for cellulose extraction. Two different pulping reagents were used, sodium sulfite and sodium metabisulfite. The effect of the main process parameters, sulfite agent dosage and reaction duration, on cellulose yield was investigated. A central composite rotatable design involving two variables at five levels and response surface methodology were used for the optimization of cellulose recovery. Other two invariable parameters were reaction temperature and hydromodulus. The optimum yields, referred to the weight of double extracted OP, were 40.4% and 45.2% for sodium sulfite and sodium metabisulfite digestions, respectively. The crude celluloses were bleached with hypochlorite and oxygen. The physicochemical characterization data of these cellulose materials indicate good levels of purity, low crystallinities, good whitenesses, good water retention and moderate molecular weights. According to these specific properties the recovered celluloses could be used as fillers, water absorbents, or as raw materials for cellulose derivatives. Copyright © 2011 Elsevier Ltd. All rights reserved.
Advanced biomaterials from renewable resources: An investigation on cellulose nanocrystal composites and carbon dioxide extraction of rendered materials

NASA Astrophysics Data System (ADS)

Orellana, Jose Luis

The annual global consumption of petroleum-based plastics is approximately 280 million tons and is impacting the sustainability of our planet and prosperity of future generations. One solution is the development of bio-based polymer materials with advanced properties for commercial applications. Therefore, the ultimate goal of this dissertation is to investigate the properties of new bio-based materials for broader applications. This dissertation includes two research areas: cellulose nanocomposites, and CO2 extractions of rendered fat. In the first half, cellulose nanocrystals (CNCs), which exhibit excellent mechanical and optical properties, were investigated for the reinforcement of a biodegradable polymer. The properties of these nanocomposites were studied to intellectually contribute to the understanding of the reinforcement mechanisms of CNC nanocomposites. In the second half, a more efficient and greener extraction of fat from rendered materials (RMs) was explored to broaden their potential applications, which include protein-based polymers and biofuels. Since CNCs are hydrophilic, surface modification with various surfactants was first accomplished in this research, increasing the dispersion stability in non-polar solvents by at least a month. Only 1 wt.% of surfactant with respect to CNCs was needed to afford a significant increase in the CNC stability, representing a much lower percentage than the values reported in the literature. Moreover, these CNCs showed the ability to selfassemble into local liquid crystal structures, a potential advantage for polymer reinforcement. CNCs were subsequently investigated as an additive for polylactic acid (PLA), which is the most widely used synthetic biopolymer in the market. CNC addition yielded a 61% increase in toughness at 1 wt.% CNC load. The tensile strength and modulus were not affected by the CNC addition, addressing one of the most frequent issues in the toughening of polymers. In addition, polarized microscopy revealed selfassembly formation of the enhanced composites indicating that the reinforcement was influenced by the CNC nanoscale structure on the matrix. These structures were found to be distributed in different directions along the extrusion line, suggesting that an angled CNC orientation favored a higher toughness as observed in natural cellulose fibers. PLA was also modified by grafting polyacrylic acid (PAA), which provided a stiffer and more hydrophilic surface for the addition of unmodified CNCs. In this case, the toughness of the PLA copolymer decreased with CNC concentration, while the tensile modulus increased. This effect was attributed to an increase of polymer crystallinity upon addition of CNCs, probably due to an enhanced compatibility provided by the PAA chains. For the purpose of obtaining a more efficient separation of proteins and fats from RMs, liquid and supercritical CO2 (LCO2 and SCCO2) were explored as solvents for the extraction, demonstrating the ability to extract up to 97% of the fat in the RMs. Higher fat solubilities in LCO2 were obtained compared to SCCO2, a result attributed to a retrograde phenomenon. These results are advantageous for the separation of rendered fats at relatively low temperatures and pressures, obtaining higher yields than screw pressing currently used in the industry. However, this extraction requires high amounts of CO2 due to low fat solubilities. This issue was addressed using CO2-assisted mechanical extraction, resulting in yields up to 81%, representing a 98% increase compared to conventional extraction, and significantly reducing the amount of CO2 for the extraction.
A rapid method to extract Seebeck coefficient under a large temperature difference

NASA Astrophysics Data System (ADS)

Zhu, Qing; Kim, Hee Seok; Ren, Zhifeng

2017-09-01

The Seebeck coefficient is one of the three important properties in thermoelectric materials. Since thermoelectric materials usually work under large temperature difference in real applications, we propose a quasi-steady state method to accurately measure the Seebeck coefficient under large temperature gradient. Compared to other methods, this method is not only highly accurate but also less time consuming. It can measure the Seebeck coefficient in both the temperature heating up and cooling down processes. In this work, a Zintl material (Mg3.15Nb0.05Sb1.5Bi0.49Te0.01) was tested to extract the Seebeck coefficient from room temperature to 573 K. Compared with a commercialized Seebeck coefficient measurement device (ZEM-3), there is ±5% difference between those from ZEM-3 and this method.
Highly sensitive determination of polycyclic aromatic hydrocarbons in ambient air dust by gas chromatography-mass spectrometry after molecularly imprinted polymer extraction.

PubMed

Krupadam, Reddithota J; Bhagat, Bhagyashree; Khan, Muntazir S

2010-08-01

A method based on solid--phase extraction with a molecularly imprinted polymer (MIP) has been developed to determine five probable human carcinogenic polycyclic aromatic hydrocarbons (PAHs) in ambient air dust by gas chromatography-mass spectrometry (GC-MS). Molecularly imprinted poly(vinylpyridine-co-ethylene glycol dimethacrylate) was chosen as solid-phase extraction (SPE) material for PAHs. The conditions affecting extraction efficiency, for example surface properties, concentration of PAHs, and equilibration times were evaluated and optimized. Under optimum conditions, pre-concentration factors for MIP-SPE ranged between 80 and 93 for 10 mL ambient air dust leachate. PAHs recoveries from MIP-SPE after extraction from air dust were between 85% and 97% and calibration graphs of the PAHs showed a good linearity between 10 and 1000 ng L(-1) (r = 0.99). The extraction efficiency of MIP for PAHs was compared with that of commercially available SPE materials--powdered activated carbon (PAC) and polystyrene-divinylbenzene resin (XAD)--and it was shown that the extraction capacity of the MIP was better than that of the other two SPE materials. Organic matter in air dust had no effect on MIP extraction, which produced a clean extract for GC-MS analysis. The detection limit of the method proposed in this article is 0.15 ng L(-1) for benzo[a]pyrene, which is a marker molecule of air pollution. The method has been applied to the determination of probable carcinogenic PAHs in air dust of industrial zones and satisfactory results were obtained.
Physical-chemical properties of dental composites and adhesives containing silane-modified SBA-15.

PubMed

Martim, Gedalias Custódio; Kupfer, Vicente Lira; Moisés, Murilo Pereira; Dos Santos, Andressa; Buzzetti, Paulo Henrique Maciel; Rinaldi, Andrelson Wellington; Rubira, Adley Forti; Girotto, Emerson Marcelo

2018-04-01

The aim of this study was to synthesize and characterize mesoporous materials SBA-15 and SBA-15 modified with 3-(methacryloxy)-propyl-trimethoxysilane (MPS) to be used as inorganic filler in restorative dental composites and adhesives, and evaluate the main physical-chemical properties of the resulting material. The SBA-15 and SBA-15/MPS were characterized by FTIR, BET and X-Ray and combined with TEGDMA, bis-GMA and commercial spherical silica to produce dental composites. Afterwards, the mesoporous materials were combined with TEGDMA, bis-GMA and HEMA to make adhesives. To compare the results, composites and adhesives containing only commercial spherical silica were investigated. Some physical-chemical properties such as degree of conversion (DC), flexural strength (FS) and modulus (FM), water sorption and solubility (W sp and W sl ), specific area (BET), and the leachable components were evaluated. The SBA-15/MPS can be used to prepare dental restorative materials, with some foreseeable advantages compared with pure SBA-15 dental materials and with improved properties compared with commercial spherical silica dental materials. An important improvement was that the dental materials based on modified SBA-15 presented a reduction of approximately 60% in leaching of unreacted monomers extracted by solvent compared to the control group. Copyright © 2018 Elsevier Ltd. All rights reserved.
Effect of Different Extrusion Parameters on Dietary Fiber in Wheat Bran and Rye Bran.

PubMed

Andersson, Annica A M; Andersson, R; Jonsäll, Anette; Andersson, Jörgen; Fredriksson, Helena

2017-06-01

Wheat bran and rye bran are mostly used as animal feed today, but their high content of dietary fiber and bioactive components are beneficial to human health. Increased use of bran as food raw material could therefore be desirable. However, bran mainly contains unextractable dietary fiber and deteriorates the sensory properties of products. Processing by extrusion could increase the extractability of dietary fiber and increase the sensory qualities of bran products. Wheat bran and rye bran were therefore extruded at different levels of moisture content, screw speed and temperature, in order to find the optimal setting for increased extractability of dietary fiber and positive sensory properties. A water content of 24% for wheat bran and 30% for rye bran, a screw speed of 400 rpm, and a temperature of 130 °C resulted in the highest extractability of total dietary fiber and arabinoxylan. Arabinoxylan extractability increased from 5.8% in wheat bran to 9.0% in extruded wheat bran at those settings, and from 14.6% to 19.2% for rye bran. Total contents of dietary fiber and arabinoxylan were not affected by extrusion. Content of β-glucan was also maintained during extrusion, while its molecular weight decreased slightly and extractability increased slightly. Extrusion at these settings is therefore a suitable process for increasing the use of wheat bran and rye bran as a food raw material. © 2017 Institute of Food Technologists®.
Influence of extrahent on antioxidant capacity of Aesculus hippocastanum seeds.

PubMed

Kukula-Koch, Wirginia; Kędzierski, Bartosz; Głowniak, Kazimierz

2015-01-01

In this study, the optimisation of horse chestnut seed extraction was performed to determine the best extraction solvent in the recovery of pharmacologically active escin from raw material. All extracts were obtained by accelerated solvent extraction and were analysed for their antioxidant potential (DPPH test), phenolic content (Folin-Ciocalteu (FC) assay) and escin content (ESI-TOF-MS extracts profiling). Methanol was found to recover the highest amount of escin from the plant matrix as well as to produce the most active antiradical solutions rich in polyphenols. Radical scavenging properties of methanol extracts were calculated as 2 GAE in DPPH test and 23 GAE (mg/g) in FC assay. Quantitative analysis of extracts performed by ESI-TOF-MS measurements in ion-positive mode confirmed the presence of four major escin isomers in the extracts and showed that the high antioxidant potential of methanolic extracts went hand in hand with the highest content of escin (8.92%).
Biological properties of mud extracts derived from various spa resorts.

PubMed

Spilioti, Eliana; Vargiami, Margarita; Letsiou, Sophia; Gardikis, Konstantinos; Sygouni, Varvara; Koutsoukos, Petros; Chinou, Ioanna; Kassi, Eva; Moutsatsou, Paraskevi

2017-08-01

Spa resorts are known for thousands of years for their healing properties and have been empirically used for the treatment of many inflammatory conditions. Mud is one of the most often used natural materials for preventive, healing and cosmetic reasons and although it has been used since the antiquity, little light has been shed on its physical, chemical and biological properties. In this study we examined the effect of mud extracts on the expression of adhesion molecules (CAMs) by endothelial cells as well as their effects on monocyte adhesion to activated endothelial cells. Most of mud extracts inhibited the expression of VCAM-1 by endothelial cells and reduced monocyte adhesion to activated endothelial cells, indicating a potent anti-inflammatory activity. Furthermore, the mud extracts were tested for their antimicrobial activity; however, most of them appeared inactive against S. aureus and S. epidermidis. One of the mud extracts (showing the best stabilization features) increased significantly the expression of genes involved in cell protection, longevity and hydration of human keratinocytes, such as, collagen 6A1, forkhead box O3, sirtuin-1, superoxide dismutase 1 and aquaporin-3. The present study reveals that mud exerts important beneficial effects including anti-inflammatory and anti-aging activity as well as moisturizing effects, implicating important cosmeceutical applications.

Preparation of poly(vinyl alcohol)/chitosan/starch blends and studies on thermal and surface properties

NASA Astrophysics Data System (ADS)

Nasalapure, Anand V.; Chalannavar, Raju K.; Malabadi, Ravindra B.

2018-05-01

Biopolymers are abundantly available from its natural sources of extraction. Chitosan(CH) is one of the widely used natural polymer which is perspective natural polysaccharide. Natural polymer blend with synthetic polymer enhances property of the material such as polyvinyl alcohol (PVA). PVA is nontoxic degradable synthetic polymer and very good film forming polymer. In this study prepared hybrid based film by adding starch into Chitosan/PVA which slighlty increased the surface and thermal property of ternary blend film.
Versatile and efficient pore network extraction method using marker-based watershed segmentation

NASA Astrophysics Data System (ADS)

Gostick, Jeff T.

2017-08-01

Obtaining structural information from tomographic images of porous materials is a critical component of porous media research. Extracting pore networks is particularly valuable since it enables pore network modeling simulations which can be useful for a host of tasks from predicting transport properties to simulating performance of entire devices. This work reports an efficient algorithm for extracting networks using only standard image analysis techniques. The algorithm was applied to several standard porous materials ranging from sandstone to fibrous mats, and in all cases agreed very well with established or known values for pore and throat sizes, capillary pressure curves, and permeability. In the case of sandstone, the present algorithm was compared to the network obtained using the current state-of-the-art algorithm, and very good agreement was achieved. Most importantly, the network extracted from an image of fibrous media correctly predicted the anisotropic permeability tensor, demonstrating the critical ability to detect key structural features. The highly efficient algorithm allows extraction on fairly large images of 5003 voxels in just over 200 s. The ability for one algorithm to match materials as varied as sandstone with 20% porosity and fibrous media with 75% porosity is a significant advancement. The source code for this algorithm is provided.
Optimization of solvent extraction of shea butter (Vitellaria paradoxa) using response surface methodology and its characterization.

PubMed

Ajala, E O; Aberuagba, F; Olaniyan, A M; Onifade, K R

2016-01-01

Shea butter (SB) was extracted from its kernel by using n-hexane as solvent in an optimization study. This was to determine the optima operating variables that would give optimum yield of SB and to study the effect of solvent on the physico-chemical properties and chemical composition of SB extracted using n-hexane. A Box-behnken response surface methodology (RSM) was used for the optimization study while statistical analysis using ANOVA was used to test the significance of the variables for the process. The variables considered for this study were: sample weight (g), solvent volume (ml) and extraction time (min). The physico-chemical properties of SB extracted were determined using standard methods and Fourier Transform Infrared Spectroscopy (FTIR) for the chemical composition. The results of RSM analysis showed that the three variables investigated have significant effect (p < 0.05) on the %yield of SB, with R(2) - 0.8989 which showed good fitness of a second-order model. Based on this model, optima operating variables for the extraction process were established as: sample weight of 30.04 g, solvent volume of 346.04 ml and extraction time of 40 min, which gave 66.90 % yield of SB. Furthermore, the result of the physico-chemical properties obtained for the shea butter extracted using traditional method (SBT) showed that it is a more suitable raw material for food, biodiesel production, cosmetics, medicinal and pharmaceutical purposes than shea butter extracted using solvent extraction method (SBS). Fourier Transform Infrared Spectroscopy (FTIR) results obtained for the two samples were similar to what was obtainable from other vegetable oil.
Properties and antioxidant action of actives cassava starch films incorporated with green tea and palm oil extracts.

PubMed

Perazzo, Kátya Karine Nery Carneiro Lins; Conceição, Anderson Carlos de Vasconcelos; dos Santos, Juliana Caribé Pires; Assis, Denilson de Jesus; Souza, Carolina Oliveira; Druzian, Janice Izabel

2014-01-01

There is an interest in the development of an antioxidant packaging fully biodegradable to increase the shelf life of food products. An active film from cassava starch bio-based, incorporated with aqueous green tea extract and oil palm colorant was developed packaging. The effects of additives on the film properties were determined by measuring mechanical, barrier and thermal properties using a response surface methodology design experiment. The bio-based films were used to pack butter (maintained for 45 days) under accelerated oxidation conditions. The antioxidant action of the active films was evaluated by analyzing the peroxide index, total carotenoids, and total polyphenol. The same analysis also evaluated unpacked butter, packed in films without additives and butter packed in LDPE films, as controls. The results suggested that incorporation of the antioxidants extracts tensile strength and water vapor barrier properties (15 times lower) compared to control without additives. A lower peroxide index (231.57%), which was significantly different from that of the control (p<0.05), was detected in products packed in film formulations containing average concentration of green tea extracts and high concentration of colorant. However, it was found that the high content of polyphenols in green tea extract can be acted as a pro-oxidant agent, which suggests that the use of high concentration should be avoided as additives for films. These results support the applicability of a green tea extract and oil palm carotenoics colorant in starch films totally biodegradable and the use of these materials in active packaging of the fatty products.
Properties and Antioxidant Action of Actives Cassava Starch Films Incorporated with Green Tea and Palm Oil Extracts

PubMed Central

Perazzo, Kátya Karine Nery Carneiro Lins; Conceição, Anderson Carlos de Vasconcelos; dos Santos, Juliana Caribé Pires; Assis, Denilson de Jesus; Souza, Carolina Oliveira; Druzian, Janice Izabel

2014-01-01

There is an interest in the development of an antioxidant packaging fully biodegradable to increase the shelf life of food products. An active film from cassava starch bio-based, incorporated with aqueous green tea extract and oil palm colorant was developed packaging. The effects of additives on the film properties were determined by measuring mechanical, barrier and thermal properties using a response surface methodology design experiment. The bio-based films were used to pack butter (maintained for 45 days) under accelerated oxidation conditions. The antioxidant action of the active films was evaluated by analyzing the peroxide index, total carotenoids, and total polyphenol. The same analysis also evaluated unpacked butter, packed in films without additives and butter packed in LDPE films, as controls. The results suggested that incorporation of the antioxidants extracts tensile strength and water vapor barrier properties (15 times lower) compared to control without additives. A lower peroxide index (231.57%), which was significantly different from that of the control (p<0.05), was detected in products packed in film formulations containing average concentration of green tea extracts and high concentration of colorant. However, it was found that the high content of polyphenols in green tea extract can be acted as a pro-oxidant agent, which suggests that the use of high concentration should be avoided as additives for films. These results support the applicability of a green tea extract and oil palm carotenoics colorant in starch films totally biodegradable and the use of these materials in active packaging of the fatty products. PMID:25251437
A comparative analysis of modified binders : original asphalts and materials extracted from existing pavements : tech summary.

DOT National Transportation Integrated Search

2010-01-01

During oxidative aging, polar and aromatic molecules interact through attractive forces to form molecular associations resulting : in signifi cant changes in the physical properties of asphalts. One consequence is that these associations have eff ect...
A comparative analysis of modified binders : original asphalts and materials extracted from existing pavements : tech summary.

DOT National Transportation Integrated Search

2010-01-01

During oxidative aging, polar and aromatic molecules interact through attractive forces to form molecular associations resulting in signifi cant changes in the physical properties of asphalts. One consequence is that these associations have eff ectiv...
Influence of material uncertainties on the RLC parameters of wound inductors modeled using the finite element method

NASA Astrophysics Data System (ADS)

Lossa, Geoffrey; Deblecker, Olivier; Grève, Zacharie De

2018-05-01

In this work, we highlight the influence of the material uncertainties (magnetic permeability, electric conductivity of a Mn-Zn ferrite core, and electric permittivity of wire insulation) on the RLC parameters of a wound inductor extracted from the finite element method. To that end, the finite element method is embedded in a Monte Carlo simulation. We show that considering mentioned different material properties as real random variables, leads to significant variations in the distributions of the RLC parameters.
Deciphering chemical order/disorder and material properties at the single-atom level.

PubMed

Yang, Yongsoo; Chen, Chien-Chun; Scott, M C; Ophus, Colin; Xu, Rui; Pryor, Alan; Wu, Li; Sun, Fan; Theis, Wolfgang; Zhou, Jihan; Eisenbach, Markus; Kent, Paul R C; Sabirianov, Renat F; Zeng, Hao; Ercius, Peter; Miao, Jianwei

2017-02-01

Perfect crystals are rare in nature. Real materials often contain crystal defects and chemical order/disorder such as grain boundaries, dislocations, interfaces, surface reconstructions and point defects. Such disruption in periodicity strongly affects material properties and functionality. Despite rapid development of quantitative material characterization methods, correlating three-dimensional (3D) atomic arrangements of chemical order/disorder and crystal defects with material properties remains a challenge. On a parallel front, quantum mechanics calculations such as density functional theory (DFT) have progressed from the modelling of ideal bulk systems to modelling 'real' materials with dopants, dislocations, grain boundaries and interfaces; but these calculations rely heavily on average atomic models extracted from crystallography. To improve the predictive power of first-principles calculations, there is a pressing need to use atomic coordinates of real systems beyond average crystallographic measurements. Here we determine the 3D coordinates of 6,569 iron and 16,627 platinum atoms in an iron-platinum nanoparticle, and correlate chemical order/disorder and crystal defects with material properties at the single-atom level. We identify rich structural variety with unprecedented 3D detail including atomic composition, grain boundaries, anti-phase boundaries, anti-site point defects and swap defects. We show that the experimentally measured coordinates and chemical species with 22 picometre precision can be used as direct input for DFT calculations of material properties such as atomic spin and orbital magnetic moments and local magnetocrystalline anisotropy. This work combines 3D atomic structure determination of crystal defects with DFT calculations, which is expected to advance our understanding of structure-property relationships at the fundamental level.
Progress Toward an Integration of Process-Structure-Property-Performance Models for "Three-Dimensional (3-D) Printing" of Titanium Alloys

NASA Astrophysics Data System (ADS)

Collins, P. C.; Haden, C. V.; Ghamarian, I.; Hayes, B. J.; Ales, T.; Penso, G.; Dixit, V.; Harlow, G.

2014-07-01

Electron beam direct manufacturing, synonymously known as electron beam additive manufacturing, along with other additive "3-D printing" manufacturing processes, are receiving widespread attention as a means of producing net-shape (or near-net-shape) components, owing to potential manufacturing benefits. Yet, materials scientists know that differences in manufacturing processes often significantly influence the microstructure of even widely accepted materials and, thus, impact the properties and performance of a material in service. It is important to accelerate the understanding of the processing-structure-property relationship of materials being produced via these novel approaches in a framework that considers the performance in a statistically rigorous way. This article describes the development of a process model, the assessment of key microstructural features to be incorporated into a microstructure simulation model, a novel approach to extract a constitutive equation to predict tensile properties in Ti-6Al-4V (Ti-64), and a probabilistic approach to measure the fidelity of the property model against real data. This integrated approach will provide designers a tool to vary process parameters and understand the influence on performance, enabling design and optimization for these highly visible manufacturing approaches.
Inflated Sporopollenin Exine Capsules Obtained from Thin-Walled Pollen

NASA Astrophysics Data System (ADS)

Park, Jae Hyeon; Seo, Jeongeun; Jackman, Joshua A.; Cho, Nam-Joon

2016-06-01

Sporopollenin is a physically robust and chemically resilient biopolymer that comprises the outermost layer of pollen walls and is the first line of defense against harsh environmental conditions. The unique physicochemical properties of sporopollenin increasingly motivate the extraction of sporopollenin exine capsules (SECs) from pollen walls as a renewable source of organic microcapsules for encapsulation applications. Despite the wide range of different pollen species with varying sizes and wall thicknesses, faithful extraction of pollen-mimetic SECs has been limited to thick-walled pollen capsules with rigid mechanical properties. There is an unmet need to develop methods for producing SECs from thin-walled pollen capsules which constitute a large fraction of all pollen species and have attractive materials properties such as greater aerosol dispersion. Herein, we report the first successful extraction of inflated SEC microcapsules from a thin-walled pollen species (Zea mays), thereby overcoming traditional challenges with mechanical stability and loss of microstructure. Morphological and compositional characterization of the SECs obtained by the newly developed extraction protocol confirms successful protein removal along with preservation of nanoscale architectural features. Looking forward, there is excellent potential to apply similar strategies across a wide range of unexplored thin-walled pollen species.
Inflated Sporopollenin Exine Capsules Obtained from Thin-Walled Pollen

PubMed Central

Park, Jae Hyeon; Seo, Jeongeun; Jackman, Joshua A.; Cho, Nam-Joon

2016-01-01

Sporopollenin is a physically robust and chemically resilient biopolymer that comprises the outermost layer of pollen walls and is the first line of defense against harsh environmental conditions. The unique physicochemical properties of sporopollenin increasingly motivate the extraction of sporopollenin exine capsules (SECs) from pollen walls as a renewable source of organic microcapsules for encapsulation applications. Despite the wide range of different pollen species with varying sizes and wall thicknesses, faithful extraction of pollen-mimetic SECs has been limited to thick-walled pollen capsules with rigid mechanical properties. There is an unmet need to develop methods for producing SECs from thin-walled pollen capsules which constitute a large fraction of all pollen species and have attractive materials properties such as greater aerosol dispersion. Herein, we report the first successful extraction of inflated SEC microcapsules from a thin-walled pollen species (Zea mays), thereby overcoming traditional challenges with mechanical stability and loss of microstructure. Morphological and compositional characterization of the SECs obtained by the newly developed extraction protocol confirms successful protein removal along with preservation of nanoscale architectural features. Looking forward, there is excellent potential to apply similar strategies across a wide range of unexplored thin-walled pollen species. PMID:27302853
Polyphenol Content and Antioxidant Properties of Colored Soybean Seeds from Central Europe

PubMed Central

Cvejić, Jelena; Miladinović, Jegor

2012-01-01

Abstract The antioxidant activity and contents of various polyphenol classes in the seeds of seven soybean varieties of different seed color and one yellow seed cultivar, representing a reference genotype, were evaluated. Total polyphenols and tannins were determined after extraction of plant material with 70% aqueous acetone, and total flavonoids were extracted with methanol and acetic acid, whereas anthocyanins were extracted with 20% aqueous ethanol. In addition, isoflavone content and composition were determined using high-performance liquid chromatography analysis. Antioxidant activity of seed extracts was evaluated by the 2,2-diphenyl-1-picrylhydrazyl free radical scavenging activity assay. A positive linear correlation between antioxidant activity and contents of total polyphenols and anthocyanins was established. The highest antioxidant activity was observed in the extracts of black and brown varieties, which also showed high levels of all polyphenol classes examined. Yellow seed had the highest total isoflavone content (3.62 mg/g of dry material). The highest concentration of total daidzein was determined in black seeds (>2.0 mg/g of dry material), and the highest total glycitein and genistein contents occurred in the yellow cultivar (0.53 and 1.49 mg/g of dry material, respectively). According to our results, varieties of black and brown seeds could be of special interest not only for their large content of total polyphenols, ranging from 4.94 to 6.22 mg of gallic acid equivalents/g of dry material, but also for their high content of natural antioxidants such as anthocyanins. PMID:21861721
Ultrasound-Assisted Extraction and Identification of Natural Antioxidants from the Fruit of Melastoma sanguineum Sims.

PubMed

Zhou, Tong; Xu, Dong-Ping; Lin, Sheng-Jun; Li, Ya; Zheng, Jie; Zhou, Yue; Zhang, Jiao-Jiao; Li, Hua-Bin

2017-02-18

The fruit of Melastoma sanguineum Sims is an edible and sweet wild fruit. In our previous study, the fruit was found to have a strong antioxidant property. In this study, an ultrasound-assisted extraction (UAE) method was developed to extract natural antioxidants from the fruit of Melastoma sanguineum Sims, and a response surface methodology was used to optimize the conditions of UAE to maximize the extraction efficiency. The influence of five independent extraction parameters (ethanol concentration, solvent/material ratio, extracting time, temperature, and ultrasound power) on the extraction efficiency were investigated using a single factor experiment, and then a central composite rotatable design was used to investigate the interaction of three key parameters. The results showed that the optimal extraction conditions were 42.98% ethanol, 28.29 mL/g solvent/material ratio, 34.29 min extracting time, 60 °C temperature, and 600 W ultrasound power. Under these conditions, the Trolox equivalent antioxidant capacity (TEAC) value of the extracts was 1074.61 ± 32.56 μmol Trolox/g dry weight (DW). Compared with conventional maceration (723.27 ± 11.61 μmol Trolox/g DW) and Soxhlet extraction methods (518.37 ± 23.23 μmol Trolox/g DW), the UAE method improved the extraction efficiency, in a shorter period of time. In addition, epicatechin gallate, epicatechin, rutin, epigallocatechin, protocatechuic acid, chlorogenic acid, and quercetin, were identified and quantified in the fruit extracts of Melastoma sanguineum Sims by UPLC-MS/MS.
Biogenic porous silica and silicon sourced from Mexican Giant Horsetail (Equisetum myriochaetum) and their application as supports for enzyme immobilization.

PubMed

Sola-Rabada, Anna; Sahare, Padma; Hickman, Graham J; Vasquez, Marco; Canham, Leigh T; Perry, Carole C; Agarwal, Vivechana

2018-06-01

Porous silica-based materials are attractive for biomedical applications due to their biocompatibility and biodegradable character. In addition, inorganic supports such as porous silicon are being developed due to integrated circuit chip compatibility and tunable properties leading to a wide range of multidisciplinary applications. In this contribution, biosilica extracted from a rarely studied plant material (Equisetum Myriochaetum), its conversion to silicon and the potential for both materials to be used as supports for enzyme immobilization are investigated. E. myriochaetum was subject to conventional acid digestion to extract biogenic silica with a% yield remarkably higher (up to 3 times) than for other Equisetum sp. (i.e. E. Arvense). The surface area of the isolated silica was ∼400 m 2 /g, suitable for biotechnological applications. Biogenic silicon was obtained by magnesiothermic reduction. The materials were characterized by SEM-EDX, XRD, FT-IR, ICP-OES, TGA and BET analysis and did not contain significant levels of class 1 heavy elements (such as Pb, Cd, Hg and As). Two commercial peroxidases, horseradish peroxidase (HRP) and Coprinus cinereus peroxidase (CiP) were immobilized onto the biogenic materials using three different functionalization routes: (A) carbodiimide, (B) amine + glutaraldehyde and (C) amine + carbodiimide. Although both biogenic silica and porous silicon could be used as supports differences in behaviour were observed for the two enzymes. For HRP, loading onto biogenic silica via the glutaraldehyde immobilization technique (route B) was most effective. The loading of CiP showed a much higher peroxidase activity onto porous silicon than silica functionalized by the carbodiimide method (route A). From the properties of the extracted materials obtained from Equisetum Myriochaetum and the immobilization results observed, these materials appear to be promising for industrial and biomedical applications. Copyright © 2018 Elsevier B.V. All rights reserved.
Physical and biological properties of a novel anti-adhesion material made of thermally cross-linked gelatin film: Investigation of the usefulness as anti-adhesion material.

PubMed

Horii, Tsunehito; Tsujimoto, Hiroyuki; Miyamoto, Hiroe; Yamanaka, Koki; Tanaka, Shota; Torii, Hiroko; Ozamoto, Yuki; Takamori, Hideki; Nakamachi, Eiji; Ikada, Yoshito; Hagiwara, Akeo

2018-02-01

To create more useful, effective and safer anti-adhesion materials, we developed a thermally cross-linked gelatin film. In this study, we examined the physical properties of the film such as the physical strength and the adhesiveness to reveal the handling properties and biological properties, such as the anti-adhesion effect, the influence on cell proliferation, and the cytotoxicity to reveal the anti-adhesion mechanism, especially in comparison with the conventional hyaluronic acid and carboxymethylcellulose film (the conventional film). A tensile test under dry and wet conditions and shearing stress test showed that the gelatin film has significant higher maximum tensile stress and fracture strain than the conventional film. In the study using a rat model of cecum adhesion, the anti-adhesion effect of the gelatin film was significantly superior to that of the conventional film. In the cell proliferation test, the number of fibroblast cells on the gelatin film increased at each time point, while no cell proliferation was observed on the conventional film. Furthermore, in the cytotoxicity test using a colony assay and Live/Dead assay, the extract of the gelatin film had no cytotoxicity, while the extract of the conventional film had cytotoxicity considerably. These results suggest that the gelatin film provides better handling than the conventional film, due to better physical strength and ductility of the film. In addition, the gelatin film has a significantly greater anti-adhesion effect than the conventional film without any cytotoxicity. Therefore, the gelatin film is quite favorable as an anti-adhesion material. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 689-696, 2018. © 2017 Wiley Periodicals, Inc.
Extraction and Determination of Quercetin from Ginkgo biloba by DESs-Based Polymer Monolithic Cartridge.

PubMed

Wang, Xiaoqin; Li, Guizhen; Ho Row, Kyung

2017-09-01

Deep eutectic solvents (DES) were formed from choline chloride (ChCl). DES-modified polymer monolithic (DES-M), template molecular polymer monolithic and non-DES-M without a molecular template were synthesized in identical process. These polymer materials were characterized by field emission scanning electron microscopy and Fourier transform infrared spectroscopy. The significant selective adsorption properties of the polymers were assessed by an absorption capacity experiment and solid-phase extraction (SPE). The optimized extraction procedure was as follows: ultrasonic time (30 min), optimal solvent (ethanol) and liquid to material ratio (20 mL g-1). Under this condition, the amount of quercetin extracted from Ginkgo biloba was 290.8 mg g-1. The purification of G. biloba was achieved by the SPE process. Based on the results, DESs-based monolithic cartridges can be used for simple and efficient extraction and as a pre-concentration technique for the purification of bioactive compounds or drugs in aqueous environments with high affinity and selectivity. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
Novel characterization method for fibrous materials using non-contact acoustics: material properties revealed by ultrasonic perturbations.

PubMed

Periyaswamy, Thamizhisai; Balasubramanian, Karthikeyan; Pastore, Christopher

2015-02-01

Fibrous materials are unique hierarchical complex structures exhibiting a range of mechanical, thermal, optical and electrical properties. The inherent discontinuity at micro and macro levels, heterogeneity and multi-scale porosity differentiates fibrous materials from other engineering materials that are typically continuum in nature. These structural complexities greatly influence the techniques and modalities that can be applied to characterize fibrous materials. Typically, the material response to an applied external force is measured and used as a characteristic number of the specimen. In general, a range of equipment is in use to obtain these numbers to signify the material properties. Nevertheless, obtaining these numbers for materials like fiber ensembles is often time consuming, destructive, and requires multiple modalities. It is hypothesized that the material response to an applied acoustic frequency would provide a robust alternative characterization mode for rapid and non-destructive material analysis. This research proposes applying air-coupled ultrasonic acoustics to characterize fibrous materials. Ultrasonic frequency waves transmitted through fibrous assemblies were feature extracted to understand the correlation between the applied frequency and the material properties. Mechanical and thermal characteristics were analyzed using ultrasonic features such as time of flight, signal velocity, power and the rate of attenuation of signal amplitude. Subsequently, these temporal and spectral characteristics were mapped with the standard low-stress mechanical and thermal properties via an empirical artificial intelligence engine. A high correlation of >0.92 (S.D. 0.06) was observed between the ultrasonic features and the standard measurements. The proposed ultrasonic technique can be used toward rapid characterization of dynamic behavior of flexible fibrous assemblies. Copyright © 2014 Elsevier B.V. All rights reserved.
[Monitoring method of extraction process for Schisandrae Chinensis Fructus based on near infrared spectroscopy and multivariate statistical process control].

PubMed

Xu, Min; Zhang, Lei; Yue, Hong-Shui; Pang, Hong-Wei; Ye, Zheng-Liang; Ding, Li

2017-10-01

To establish an on-line monitoring method for extraction process of Schisandrae Chinensis Fructus, the formula medicinal material of Yiqi Fumai lyophilized injection by combining near infrared spectroscopy with multi-variable data analysis technology. The multivariate statistical process control (MSPC) model was established based on 5 normal batches in production and 2 test batches were monitored by PC scores, DModX and Hotelling T2 control charts. The results showed that MSPC model had a good monitoring ability for the extraction process. The application of the MSPC model to actual production process could effectively achieve on-line monitoring for extraction process of Schisandrae Chinensis Fructus, and can reflect the change of material properties in the production process in real time. This established process monitoring method could provide reference for the application of process analysis technology in the process quality control of traditional Chinese medicine injections. Copyright© by the Chinese Pharmaceutical Association.
Materials Fabrication from Bombyx mori Silk Fibroin

PubMed Central

Rockwood, Danielle N.; Preda, Rucsanda C.; Yücel, Tuna; Wang, Xiaoqin; Lovett, Michael L.; Kaplan, David L.

2013-01-01

Silk fibroin, derived from Bombyx mori cocoons, is a widely used and studied protein polymer for biomaterial applications. Silk fibroin has remarkable mechanical properties when formed into different materials, demonstrates biocompatibility, has controllable degradation rates from hours to years, and it can be chemically modified to alter surface properties or to immobilize growth factors. A variety of aqueous or organic solvent processing methods can be used to generate silk biomaterials for a range of applications. In this protocol we include methods to extract silk from B. mori cocoons in order to fabricate hydrogels, tubes, sponges, composites, fibers, microspheres and thin films. These materials can be used directly as biomaterials for implants, as scaffolding in tissue engineering and in vitro disease models, and for drug delivery. PMID:21959241

Finite amplitude effects on drop levitation for material properties measurement

NASA Astrophysics Data System (ADS)

Ansari Hosseinzadeh, Vahideh; Holt, R. Glynn

2017-05-01

The method of exciting shape oscillation of drops to extract material properties has a long history, which is most often coupled with the technique of acoustic levitation to achieve non-contact manipulation of the drop sample. We revisit this method with application to the inference of bulk shear viscosity and surface tension. The literature is replete with references to a "10% oscillation amplitude" as a sufficient condition for the application of Lamb's analytical expressions for the shape oscillations of viscous liquids. Our results show that even a 10% oscillation amplitude leads to dynamic effects which render Lamb's results inapplicable. By comparison with samples of known viscosity and surface tension, we illustrate the complicating finite-amplitude effects (mode-splitting and excess dissipation associated with vorticity) that can occur and then show that sufficiently small oscillations allow us to recover the correct material properties using Lamb's formula.
Cellulose nanocrystals, nanofibers, and their composites as renewable smart materials

NASA Astrophysics Data System (ADS)

Kim, Jaehwan; Zhai, Lindong; Mun, Seongcheol; Ko, Hyun-U.; Yun, Young-Min

2015-04-01

Cellulose is one of abundant renewable biomaterials in the world. Over 1.5 trillion tons of cellulose is produced per year in nature by biosynthesis, forming microfibrils which in turn aggregate to form cellulose fibers. Using new effective methods these microfibrils can be disintegrated from the fibers to nanosized materials, so called cellulose nanocrystal (CNC) and cellulose nanofiber (CNF). The CNC and CNF have extremely good strength properties, dimensional stability, thermal stability and good optical properties on top of their renewable behavior, which can be a building block of new materials. This paper represents recent advancement of cellulose nanocrystals and cellulose nanofibers, followed by their possibility for smart materials. Natural behaviors, extraction, modification of cellulose nanocrystals and fibers are explained and their synthesis with nanomaterials is introduced, which is necessary to meet the technological requirements for smart materials. Also, its challenges are addressed.
Dynamic characterization of high damping viscoelastic materials from vibration test data

NASA Astrophysics Data System (ADS)

Martinez-Agirre, Manex; Elejabarrieta, María Jesús

2011-08-01

The numerical analysis and design of structural systems involving viscoelastic damping materials require knowledge of material properties and proper mathematical models. A new inverse method for the dynamic characterization of high damping and strong frequency-dependent viscoelastic materials from vibration test data measured by forced vibration tests with resonance is presented. Classical material parameter extraction methods are reviewed; their accuracy for characterizing high damping materials is discussed; and the bases of the new analysis method are detailed. The proposed inverse method minimizes the residue between the experimental and theoretical dynamic response at certain discrete frequencies selected by the user in order to identify the parameters of the material constitutive model. Thus, the material properties are identified in the whole bandwidth under study and not just at resonances. Moreover, the use of control frequencies makes the method insensitive to experimental noise and the efficiency is notably enhanced. Therefore, the number of tests required is drastically reduced and the overall process is carried out faster and more accurately. The effectiveness of the proposed method is demonstrated with the characterization of a CLD (constrained layer damping) cantilever beam. First, the elastic properties of the constraining layers are identified from the dynamic response of a metallic cantilever beam. Then, the viscoelastic properties of the core, represented by a four-parameter fractional derivative model, are identified from the dynamic response of a CLD cantilever beam.
Complex investigation of extraction techniques applied for cyclitols and sugars isolation from different species of Solidago genus.

PubMed

Ratiu, Ileana-Andreea; Al-Suod, Hossam; Ligor, Magdalena; Ligor, Tomasz; Railean-Plugaru, Viorica; Buszewski, Bogusław

2018-03-15

Cyclitols are phytochemicals naturally occurring in plant material, which attracted an increasing interest due to multiple medicinal attributes, among which the most important are the antidiabetic, antioxidant, and anticancer properties. Due to their valuable properties, sugars are used in the food industry as sweeteners, preservatives, texture modifiers, fermentation substrates, and flavoring and coloring agents. In this study, we report for the first time the quantitative analysis of sugars and cyclitols isolated from Solidago virgaurea L., which was used for the selection of the optimal solvent and extraction technique that can provide the best possible yield. Moreover, the quantities of sugars and cyclitols extracted from two other species, Solidago canadensis and Solidago gigantea, were investigated using the best extraction method and the most appropriate solvent. Comparative analysis of natural plant extracts obtained using five different techniques-maceration, Soxhlet extraction, pressurized liquid extraction, ultrasound-assisted extraction, and supercritical fluid extraction-was performed in order to decide the most suitable, efficient, and economically convenient extraction method. Three different solvents were used. Analysis of samples has been performed by solid-phase extraction for purification and pre-concentration, followed by derivation and GC-MS analysis. Highest efficiency for the total amount of obtained compounds has been reached by PLE, when water was used as a solvent. d-pinitol amount was almost similar for every solvent and for all the extraction techniques involved. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
STEAM: a software tool based on empirical analysis for micro electro mechanical systems

NASA Astrophysics Data System (ADS)

Devasia, Archana; Pasupuleti, Ajay; Sahin, Ferat

2006-03-01

In this research a generalized software framework that enables accurate computer aided design of MEMS devices is developed. The proposed simulation engine utilizes a novel material property estimation technique that generates effective material properties at the microscopic level. The material property models were developed based on empirical analysis and the behavior extraction of standard test structures. A literature review is provided on the physical phenomena that govern the mechanical behavior of thin films materials. This survey indicates that the present day models operate under a wide range of assumptions that may not be applicable to the micro-world. Thus, this methodology is foreseen to be an essential tool for MEMS designers as it would develop empirical models that relate the loading parameters, material properties, and the geometry of the microstructures with its performance characteristics. This process involves learning the relationship between the above parameters using non-parametric learning algorithms such as radial basis function networks and genetic algorithms. The proposed simulation engine has a graphical user interface (GUI) which is very adaptable, flexible, and transparent. The GUI is able to encompass all parameters associated with the determination of the desired material property so as to create models that provide an accurate estimation of the desired property. This technique was verified by fabricating and simulating bilayer cantilevers consisting of aluminum and glass (TEOS oxide) in our previous work. The results obtained were found to be very encouraging.
Fish scale collagen sponge incorporated with Macrotyloma uniflorum plant extract as a possible wound/burn dressing material.

PubMed

Muthukumar, Thangavelu; Prabu, P; Ghosh, Kausik; Sastry, Thotapalli Parvathaleswara

2014-01-01

Application of plant extracts for the burn/wound treatment is followed over the decades as a common practice and it is an important aspect in clinical management. In this study porous collagen sponges (CS) were prepared using fish scales and were incorporated with mupirocin (CSM) and extracts of Macrotyloma uniflorum (CSPE) separately to impart antimicrobial activity to the sponges. The results showed that the addition of plant extract increased the tensile strength of CSPE and stability against collagenase enzyme. FTIR studies have shown the incorporation of plant extract in CSPE, SEM studies have revealed the porous nature of the sponges and XRD patterns have shown the retention of collagen triple helical structure even after the addition of plant extract. CSPE and CSM have exhibited antimicrobial properties. The sponges prepared were analysed for their in vitro biocompatibility studies using fibroblasts and keratinocyte cell lines and the results have shown their biocompatible nature. Based on the results obtained, CS, CSM and CSPE may be tried as a burn/wound dressing materials, initially, in small animals in vivo. Copyright © 2013 Elsevier B.V. All rights reserved.
Inhibition of LDL oxidation and oxidized LDL-induced foam cell formation in RAW 264.7 cells show anti-atherogenic properties of a foliar methanol extract of Scoparia dulcis

PubMed Central

Nambiar, Sinjitha S.; Shetty, Nandini Prasad; Bhatt, Praveena; Neelwarne, Bhagyalakshmi

2014-01-01

Background: Oxidation of low density lipoproteins and their further uptake by macrophages is known to result in the formation of foam cells, which are critical in the initiation of atherosclerosis through activation of inflammatory signalling cascades. Thus, powerful dietary antioxidants are receiving attention for the reversal of such pathological states. Materials and Methods: Extracts of Scoparia dulcis have been used as tea and health drinks with various health promoting effects. In the present study, we examined the reactive oxygen scavenging potential as well as anti-inflammatory and anti-atherogenic efficacies, using leaf extracts obtained after successive extraction with various solvents. Results: A methanol extract showed potent antioxidant activity with an IC50 value of 570 μg/ml, caused hydrogen peroxide scavenging (28.9 µg/ml) and anti-inflammatory effects by improving human erythrocyte membrane stabilisation (about 86%). The methanol extract also efficiently inhibited lipid peroxidation and oxidation of low density lipoproteins, thus preventing foam cell formation in cultured RAW 264.7 cells. Furthermore, phytochemical screening of the extracts showed high accumulation of flavonoids. Conclusions: The foliar methanol extract of Scoparia dulcis has a strong anti-atherogenic potential and this property could be attributed maybe due to presence of flavonoids since HPLC analysis showed high concentrations of myricetin and rutin in the methanol extract. PMID:24991098
A solution-processed binary cathode interfacial layer facilitates electron extraction for inverted polymer solar cells.

PubMed

Zhang, Xinyuan; Li, Zhiqi; Liu, Chunyu; Guo, Jiaxin; Shen, Liang; Guo, Wenbin

2018-03-15

The charge transfer and separation are significantly affected by the electron properties of the interface between the electron-donor layer and the carrier-transporting layer in polymer solar cells (PSCs). In this study, we investigate the electron extraction mechanism of PSCs with a low temperature solution-processed ZnO/PEI as electron transport layer. The incorporation of PEI layer can decrease the work function of ZnO and reduce interfacial barrier, which facilitates electron extraction and suppresses bimolecular recombination, leading to a significant performance enhancement. Furthermore, PEI layer can induce phase separation and passivite inorganic surface trap states as well as shift the interfacial energy offset between metal oxide and organic materials. This work offers a simple and effective way to improve the charge transporting property of organic photovoltaic devices. Copyright © 2017 Elsevier Inc. All rights reserved.
Essential oils: extraction, bioactivities, and their uses for food preservation.

PubMed

Tongnuanchan, Phakawat; Benjakul, Soottawat

2014-07-01

Essential oils are concentrated liquids of complex mixtures of volatile compounds and can be extracted from several plant organs. Essential oils are a good source of several bioactive compounds, which possess antioxidative and antimicrobial properties. In addition, some essential oils have been used as medicine. Furthermore, the uses of essential oils have received increasing attention as the natural additives for the shelf-life extension of food products, due to the risk in using synthetic preservatives. Essential oils can be incorporated into packaging, in which they can provide multifunctions termed "active or smart packaging." Those essential oils are able to modify the matrix of packaging materials, thereby rendering the improved properties. This review covers up-to-date literatures on essential oils including sources, chemical composition, extraction methods, bioactivities, and their applications, particularly with the emphasis on preservation and the shelf-life extension of food products. © 2014 Institute of Food Technologists®
Pulsed Laser Techniques to Determine Lattice and Radiative Thermal Conductivity of Deep Planetary Materials at Extreme Pressure-Temperature Conditions

NASA Astrophysics Data System (ADS)

Lobanov, S.; Goncharov, A. F.; Holtgrewe, N.; Konopkova, Z.; McWilliams, R. S.

2017-12-01

Thermal conductivity of deep planetary materials determines the planetary heat transport mode and properties (e.g. magnetic field) and can be used to decipher the planetary thermal history. Due to the lack of direct measurements of the lattice and radiative conductivity of the relevant materials at the planetary conditions, the current geodynamical models use theoretical calculations and extrapolations of the available experimental data. Here we describe our pulsed laser techniques that enable direct measurements of the lattice and radiative lattice conductivity of the Earth's mantle and core materials and also of noble gases and simple molecules present in the interiors of giant planets (e.g. hydrogen). Flash heating laser techniques working in a pump-probe mode that include time resolved two-side radiative and thermoreflection temperature probes employ various laser and photo-detector configurations, which provide a measure of the thermal fluxes propagating through the samples confined in the diamond anvil cell cavity. A supercontinuum ultra-bright broadband laser source empower accurate measurements of the optical properties of planetary materials used to extract the radiative conductivity. Finite element calculations serve to extract the temperature and pressure dependent thermal conductivity and temperature gradients across the sample. We report thermal conductivity measurements of the Earth's minerals (postperovskite, bridgmanite, ferropericlase) and their assemblies (pyrolite) and core materials (Fe and alloys with Si and O) at the realistic deep Earth's pressure temperature conditions. We thank J.-F.Lin, M. Murakami, J. Badro for contributing to this work.
Measuring nanoscale viscoelastic parameters of cells directly from AFM force-displacement curves.

PubMed

Efremov, Yuri M; Wang, Wen-Horng; Hardy, Shana D; Geahlen, Robert L; Raman, Arvind

2017-05-08

Force-displacement (F-Z) curves are the most commonly used Atomic Force Microscopy (AFM) mode to measure the local, nanoscale elastic properties of soft materials like living cells. Yet a theoretical framework has been lacking that allows the post-processing of F-Z data to extract their viscoelastic constitutive parameters. Here, we propose a new method to extract nanoscale viscoelastic properties of soft samples like living cells and hydrogels directly from conventional AFM F-Z experiments, thereby creating a common platform for the analysis of cell elastic and viscoelastic properties with arbitrary linear constitutive relations. The method based on the elastic-viscoelastic correspondence principle was validated using finite element (FE) simulations and by comparison with the existed AFM techniques on living cells and hydrogels. The method also allows a discrimination of which viscoelastic relaxation model, for example, standard linear solid (SLS) or power-law rheology (PLR), best suits the experimental data. The method was used to extract the viscoelastic properties of benign and cancerous cell lines (NIH 3T3 fibroblasts, NMuMG epithelial, MDA-MB-231 and MCF-7 breast cancer cells). Finally, we studied the changes in viscoelastic properties related to tumorigenesis including TGF-β induced epithelial-to-mesenchymal transition on NMuMG cells and Syk expression induced phenotype changes in MDA-MB-231 cells.
Influence of the type of oxidant on anion exchange properties of fibrous Cladophora cellulose/polypyrrole composites.

PubMed

Razaq, Aamir; Mihranyan, Albert; Welch, Ken; Nyholm, Leif; Strømme, Maria

2009-01-15

The electrochemically controlled anion absorption properties of a novel large surface area composite paper material composed of polypyrrole (PPy) and cellulose derived from Cladophora sp. algae, synthesized with two oxidizing agents, iron(III) chloride and phosphomolybdic acid (PMo), were analyzed in four different electrolytes containing anions (i.e., chloride, aspartate, glutamate, and p-toluenesulfonate) of varying size.The composites were characterized with scanning and transmission electron microscopy, N2 gas adsorption,and conductivity measurements. The potential-controlled ion exchange properties of the materials were studied by cyclic voltammetry and chronoamperometry at varying potentials. The surface area and conductivity of the iron(III) chloride synthesized sample were 58.8 m2/g and 0.65 S/cm, respectively, while the corresponding values for the PMo synthesized sample were 31.3 m2/g and 0.12 S/cm. The number of absorbed ions per sample mass was found to be larger for the iron(III) chloride synthesized sample than for the PMo synthesized one in all four electrolytes. Although the largest extraction yields were obtained in the presence of the smallest anion (i.e., chloride) for both samples, the relative degree of extraction for the largest ions (i.e., glutamate and p-toluenesulfonate) was higher for the PMo sample. This clearly shows that it is possible to increase the extraction yield of large anions by carrying out the PPy polymerization in the presence of large anions. The results likewise show that high ion exchange capacities, as well as extraction and desorption rates, can be obtained for large anions with high surface area composites coated with relatively thin layers of PPy.
Characterisation and antimicrobial activity of active polypropylene films containing oregano essential oil and Allium extract to be used in packaging for meat products.

PubMed

Llana-Ruiz-Cabello, María; Pichardo, Silvia; Bermudez, José María; Baños, Alberto; Ariza, Juan José; Guillamón, Enrique; Aucejo, Susana; Cameán, Ana M

2018-04-01

Cooked ham is more prone to spoilage than other meat products, making preservation a key step in its commercialisation. One of the most promising preservation strategies is the use of active packaging. Oregano essential oil (OEO) and Proallium® (an Allium extract) have previously been shown to be useful in polylactic acid (PLA)-active films for ready-to-eat salads. The present work aims to study the suitability of polypropylene (PP) films containing OEO and Proallium® in the preservation of cooked ham. Concerning the technological features of the studied material, no significant changes in the mechanical or optical properties of PP films containing the active substances were recorded in comparison to the PP film without extracts. However, films containing both active substances were more flexible than the control film and less strong, highlighting the plasticisation effect of the natural extracts. Moreover, physical properties changed when active substances were added to the film. Incorporation of 4% Proallium® affected the transparency of the film to a higher extent compared to 8% OEO, undergoing decreases in transparency of 40% and 45%, respectively. Moreover, only the film containing the highest amount of OEO (8%) significantly decreased the thickness. Both active substances showed antibacterial properties; however, Proallium®-active films seemed to be more effective against Brochothrix thermosphacta than PP films containing OEO, with all percentages of Proallium® killing the bacterial population present in the ham after 60 days. In addition, materials containing the lowest Proallium® content exhibited higher acceptability by consumers in the sensory analyses with 63-100% willing to purchase, better even than the control package (56-89%). In fact, 2% of Proallium® obtained the best results in the odour study performed by the panellists.
Bio-insecticidal activities of halophytic plant extracts against Tribolium confusum (Coleoptera, Tenebrionidae).

PubMed

Saïdana, D; Ben Halima-Kamel, M; Ben Tiba, B; Haouas, D; Mahjoub, M A; Mighri, Z; Helal, A N

2005-01-01

Salt marsh plants were tested for their insecticidal activities against larvae of the confused flour beetle Tribolium confusum (Tenebrionidae). 16 aerial part extracts were obtained using organic solvents of increasing polarity and tested for their anti-feedant and toxicity effects. Responses varied with plant material and extract type. Ethyl acetate extracts of F. laevis, S. echioides and. T. boveana and petroleum ether extract of F. laevis presented, anti-feedant property. However, S. fructicosa seemed to be attractive to the tested flour beetle. Mortalities of 97, 87, 97 and 80% were observed by using respectively ethyl acetate extracts of F. laevis, S. echioides and T. boveana and petroleum ether extract of F. laevis, when applied at a dose of 1%, mixed with the insect diet. This preliminary study showed that F. laevis, S. echioides and T. boveana presented potential bio-insecticidal activity with ethyl acetate extracts, similar result was found with petroleum ether extract of F. laevis. More complementary studies are needed for the use of these extracts to control T. confusum.
Evaluation of Antioxidant Activity and Growth Control Properties of Nonoscale Structure Produced from Aloe vera var. littoralis Extract on Clinical Isolates of Salmonella

PubMed Central

Hosseiny, Hossein

2017-01-01

The aim of the study was to examine antibacterial properties of microemulsion structure produced from Aloe vera var. littoralis extract as a new tool of nanoscale drug-like materials. Aloe vera var. littoralis (A. littoralis) extract was prepared by distillation method. A nonocarrier structure in the microemulsion system was prepared from the extract. Serial concentrations were prepared from 8 mg/mL extract and the nonocarrier containing 0.1 mg/mL pure extract and were evaluated by a disk diffusion method for 35 Salmonella clinical isolates. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined by microbroth dilution assay using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) method by an enzyme-linked immunosorbent assay(ELISA) Microplate Reader apparatus. Antioxidant activity of the extract was determined by measuring the ferric reducing ability of plasma (FRAP) assay. From 35 clinical isolates of Salmonella, 17 isolates—including resistant isolates of S.E.1103 and S.E.49—had a zone of inhibition (ZI) of 7 to 32 mm in 0.007 mg/mL of the extract. S.E.76 isolate exposed to 30 µg/mL ceftazidime disk had a ZI of 12 mm but had 10 mm in 7µg/mL of A. littoralis extract. The inhibitory effect of a nanocarrier at a concentration of 25 µg/mL by 20 mm ZI was comparable by the ceftazidime (30 µg/mL) effect. MIC50 was 0.25 mg/mL and MBC50 was 0.5 mg/mL by MTT method for the extract. It was shown that A.littoralis extract had antioxidant activity of 31.67 µM/mg that could be increased based on concentration. It was concluded that the nanocarrier had a significant effect on the studied isolates in comparison with ordinary antibiotics and had potential for use as a natural antioxidant and antimicrobial material in complementary medicine. PMID:28758958
Choice of solvent extraction technique affects fatty acid composition of pistachio (Pistacia vera L.) oil.

PubMed

Abdolshahi, Anna; Majd, Mojtaba Heydari; Rad, Javad Sharifi; Taheri, Mehrdad; Shabani, Aliakbar; Teixeira da Silva, Jaime A

2015-04-01

Pistachio (Pistacia vera L.) oil has important nutritional and therapeutic properties because of its high concentration of essential fatty acids. The extraction method used to obtain natural compounds from raw material is critical for product quality, in particular to protect nutritional value. This study compared the fatty acid composition of pistachio oil extracted by two conventional procedures, Soxhlet extraction and maceration, analyzed by a gas chromatography-flame ionization detector (GC-FID). Four solvents with different polarities were tested: n-hexane (Hx), dichloromethane (DCM), ethyl acetate (EtAc) and ethanol (EtOH). The highest unsaturated fatty acid content (88.493 %) was obtained by Soxhlet extraction with EtAc. The Soxhlet method extracted the most oleic and linolenic acids (51.99 % and 0.385 %, respectively) although a higher concentration (36.32 %) of linoleic acid was extracted by maceration.
Allergenic Properties of Enzymatically Hydrolyzed Peanut Flour Extracts

USDA-ARS?s Scientific Manuscript database

Peanut flour is a high protein, low oil, powdered material prepared from roasted 21 peanut seed. In addition to being a well-established food ingredient, peanut flour is also the 22 active ingredient in peanut oral immunotherapy trials. Enzymatic hydrolysis was evaluated as a 23 processing strategy ...
Compression and Associated Properties of Boron Carbide

DTIC Science & Technology

2008-12-01

of Brookhaven National Laboratory ( BNL ) with the light extracted from the x-ray source in a method previously described (Liu et al., 2002).. A...are sharper and more intense relative to as received material. ACKNOWLEDGMENTS Thanks are due to Dr. Jingzhu Hu and Dr. Zhenxian Liu of BNL
Observation of Enhanced Hole Extraction in Br Concentration Gradient Perovskite Materials.

PubMed

Kim, Min-Cheol; Kim, Byeong Jo; Son, Dae-Yong; Park, Nam-Gyu; Jung, Hyun Suk; Choi, Mansoo

2016-09-14

Enhancing hole extraction inside the perovskite layer is the key factor for boosting photovoltaic performance. Realization of halide concentration gradient perovskite materials has been expected to exhibit rapid hole extraction due to the precise bandgap tuning. Moreover, a formation of Br-rich region on the tri-iodide perovskite layer is expected to enhance moisture stability without a loss of current density. However, conventional synthetic techniques of perovskite materials such as the solution process have not achieved the realization of halide concentration gradient perovskite materials. In this report, we demonstrate the fabrication of Br concentration gradient mixed halide perovskite materials using a novel and facile halide conversion method based on vaporized hydrobromic acid. Accelerated hole extraction and enhanced lifetime due to Br gradient was verified by observing photoluminescence properties. Through the combination of secondary ion mass spectroscopy and transmission electron microscopy with energy-dispersive X-ray spectroscopy analysis, the diffusion behavior of Br ions in perovskite materials was investigated. The Br-gradient was found to be eventually converted into a homogeneous mixed halide layer after undergoing an intermixing process. Br-substituted perovskite solar cells exhibited a power conversion efficiency of 18.94% due to an increase in open circuit voltage from 1.08 to 1.11 V and an advance in fill-factor from 0.71 to 0.74. Long-term stability was also dramatically enhanced after the conversion process, i.e., the power conversion efficiency of the post-treated device has remained over 97% of the initial value under high humid conditions (40-90%) without any encapsulation for 4 weeks.
Using Microwaves for Extracting Water from the Moon

NASA Technical Reports Server (NTRS)

Ethridge, Edwin C.; Kaukler, William; Hepburn, Frank

2009-01-01

This disk contains 2 videos that accompanies the talk. Twenty years ago, the Lunar Prospector remote sensing satellite provided evidence of relatively large hydrogen concentrations at the lunar poles and in particular concentrated in permanently shadowed craters. The scientific hypothesis is that the hydrogen is in the form of cryo-trapped water just under the surface of the soil. If true this would mean that an average of about 2% water ice is mixed with the lunar soil existing in the form of ice at cryogenic temperatures. For 5 years we have been investigating the use of microwaves for the processing of lunar soil. One of the early uses could be to use microwave energy to extract volatiles and in particular water from the lunar permafrost. Prototype experiments have shown that microwave energy at 2.45 GHz, as in consumer microwave ovens, will couple with and heat cryogenically cooled lunar soil permafrost simulant, resulting in the rapid sublimation of water vapor into the vacuum chamber. The water vapor has been collected on a cryogenic cold trap with high efficiency. The primary advantage of microwave processing is that the volatiles can be extracted in situ. Excavation would not be required. Microwave frequency dielectric property measurements are being made of different lunar soil simulants and plans are to measure Apollo lunar soil at different frequencies and over a range of temperatures. The materials properties are being used to evaluate the heating of lunar soil and develop COMSOL models that can be used to evaluate different microwave extraction scenarios. With COMSOL the heating from cryogenic temperatures can be calculated and COMSOL will permit temperature dependent materials properties to be used during the heating process. Calculations at different microwave frequencies will allow the evaluation of the type of hardware that would be needed to most efficiently extract the water and other volatiles. The 1st video shows the results of the COMSOL models. The second video shows brief views of the lunar surface.

Using Microwaves for Extracting Water from the Moon

NASA Technical Reports Server (NTRS)

Ethridge, Edwin C.; Kaukler, William; Hepburn, Frank

2009-01-01

This disk contains a video that accompanies the talk. Twenty years ago, the Lunar Prospector remote sensing satellite provided evidence of relatively large hydrogen concentrations at the lunar poles and in particular concentrated in permanently shadowed craters. The scientific hypothesis is that the hydrogen is in the form of cryo-trapped water just under the surface of the soil. If true this would mean that an average of about 2% water ice is mixed with the lunar soil existing in the form of ice at cryogenic temperatures. For 5 years we have been investigating the use of microwaves for the processing of lunar soil. One of the early uses could be to use microwave energy to extract volatiles and in particular water from the lunar permafrost. Prototype experiments have shown that microwave energy at 2.45 GHz, as in consumer microwave ovens, will couple with and heat cryogenically cooled lunar soil permafrost simulant, resulting in the rapid sublimation of water vapor into the vacuum chamber. The water vapor has been collected on a cryogenic cold trap with high efficiency. The primary advantage of microwave processing is that the volatiles can be extracted in situ. Excavation would not be required. Microwave frequency dielectric property measurements are being made of different lunar soil simulants and plans are to measure Apollo lunar soil at different frequencies and over a range of temperatures. The materials properties are being used to evaluate the heating of lunar soil and develop COMSOL models that can be used to evaluate different microwave extraction scenarios. With COMSOL the heating from cryogenic temperatures can be calculated and COMSOL will permit temperature dependent materials properties to be used during the heating process. Calculations at different microwave frequencies will allow the evaluation of the type of hardware that would be needed to most efficiently extract the water and other volatiles. The video shows the partial results of the COMSOL modeling.
Deciphering chemical order/disorder and material properties at the single-atom level

DOE PAGES

Yang, Yongsoo; Chen, Chien-Chun; Scott, M. C.; ...

2017-02-01

Perfect crystals are rare in nature. Real materials often contain crystal defects and chemical order/disorder such as grain boundaries, dislocations, interfaces, surface reconstructions and point defects. Such disruption in periodicity strongly affects material properties and functionality. Despite rapid development of quantitative material characterization methods, correlating three-dimensional (3D) atomic arrangements of chemical order/disorder and crystal defects with material properties remains a challenge. On a parallel front, quantum mechanics calculations such as density functional theory (DFT) have progressed from the modelling of ideal bulk systems to modelling ‘real’ materials with dopants, dislocations, grain boundaries and interfaces; but these calculations rely heavily onmore » average atomic models extracted from crystallography. To improve the predictive power of first-principles calculations, there is a pressing need to use atomic coordinates of real systems beyond average crystallographic measurements. Here we determine the 3D coordinates of 6,569 iron and 16,627 platinum atoms in an iron-platinum nanoparticle, and correlate chemical order/disorder and crystal defects with material properties at the single-atom level. We identify rich structural variety with unprecedented 3D detail including atomic composition, grain boundaries, anti-phase boundaries, anti-site point defects and swap defects. We show that the experimentally measured coordinates and chemical species with 22 picometre precision can be used as direct input for DFT calculations of material properties such as atomic spin and orbital magnetic moments and local magnetocrystalline anisotropy. The work presented here combines 3D atomic structure determination of crystal defects with DFT calculations, which is expected to advance our understanding of structure–property relationships at the fundamental level.« less
PHYTOCHEMICAL SCREENING, ANTI-INFLAMMATORY AND ANALGESIC PROPERTIES OF PENTANISIA PRUNELLOIDES FROM THE EASTERN CAPE PROVINCE, SOUTH AFRICA.

PubMed

Mathews, Miya Gugulethu; Ajayi, Oyemitan Idris; Opeoluwa, Oyedeji Oyehan; Oluwatobi, Oluwafemi Samuel; Benedicta N, Nkeh-Chungag; Phindile, Songca Sandile; Oyedeji; Omowumi, Adebola

2016-01-01

Pentanisia prunelloides is a medicinal plant widely used to remedy various ailments including infections, fever and rheumatism in Eastern Cape Province of South Africa. There is scanty report on the phytochemical and biological properties of the plant; hence various solvent extracts of the dried plant materials were phytochemically screened, and its aqueous extract evaluated for acute toxicity effect, analgesic and antiinflammatory properties in rodents. Different extracts of both leaf and rhizome were obtained separately with ethanol, methanol and water. Portions of the filtrate were used for qualitative screening of secondary metabolites and remaining portions were concentrated and dried. Dried grounded leaf and rhizome of the plant were also used for quantitative screening for some major components. The aqueous extract of the leaf and rhizome were used for acute toxicity (LD 50 ) test, antiinflammatory and analgesic activities in rodents. The qualitative phytochemical screening showed the presence of several phytoconstituents with saponins, flavonoids and alkaloids constituting highest constituents in the leaf and rhizome. The LD50: of the aqueous extracts (from leaf or rhizome) was found to be ≥5000 mg/kg orally. The leaf and rhizome aqueous extract (250-500 mg/kg) significantly (p<0.01) reduced egg albumin-induced paw oedema and paw licking in mice induced by formalin, signifying antinociceptive and antiinflammatory activities respectively. It is concluded that the leaf and rhizome of P. prunelloides are rich in various phytochemicals which could be associated with their medicinal uses. The aqueous leaf and rhizome extracts are similarly non-toxic orally, showed antiinflammatory and analgesic potentials thus rationalizing its use in folkloric medicine.
Identification of the full anisotropic flow resistivity tensor for multiple glass wool and melamine foam samples.

PubMed

Van der Kelen, Christophe; Göransson, Peter

2013-12-01

The flow resistivity tensor, which is the inverse of the viscous permeability tensor, is one of the most important material properties for the acoustic performance of porous materials used in acoustic treatments. Due to the manufacturing processes involved, these porous materials are most often geometrically anisotropic on a microscopic scale, and for demanding applications, there is a need for improved characterization methods. This paper discusses recent refinements of a method for the identification of the anisotropic flow resistivity tensor. The inverse estimation is verified for three fictitious materials with different degrees of anisotropy. Measurements are performed on nine glass wool samples and seven melamine foam samples, and the anisotropic flow resistivity tensors obtained are validated by comparison to measurements performed on uni-directional cylindrical samples, extracted from the same, previously measured cubic samples. The variability of flow resistivity in the batch of material from which the glass wool is extracted is discussed. The results for the melamine foam suggest that there is a relation between the direction of highest flow resistivity, and the rise direction of the material.
Mechanical Behavior Optimization of Chitosan Extracted from Shrimp Shells as a Sustainable Material for Shopping Bags.

PubMed

D'Angelo, Giacomo; Elhussieny, Amal; Faisal, Marwa; Fahim, I S; Everitt, Nicola M

2018-05-22

The use of biodegradable materials for shopping bag production, and other products made from plastics, has recently been an object of intense research-with the aim of reducing the environmental burdens given by conventional materials. Chitosan is a potential material because of its biocompatibility, degradability, and non-toxicity. It is a semi-natural biopolymeric material produced by the deacetylation of chitin, which is the second most abundant natural biopolymer (after cellulose). Chitin is found in the exoskeleton of insects, marine crustaceans, and the cell walls of certain fungi and algae. The raw materials most abundantly available are the shells of crab, shrimp, and prawn. Hence, in this study chitosan was selected as one of the main components of biodegradable materials used for shopping bag production. Firstly, chitin was extracted from shrimp shell waste and then converted to chitosan. The chitosan was next ground to a powder. Although, currently, polyethylene bags are prepared by blown extrusion, in this preliminary research the chitosan powder was dissolved in a solvent and the films were cast. Composite films with several fillers were used as a reinforcement at different dosages to optimize mechanical properties, which have been assessed using tensile tests. These results were compared with those of conventional polyethylene bags used in Egypt. Overall, the chitosan films were found to have a lower ductility but appeared to be strong enough to fulfill shopping bag functions. The addition of fillers, such as chitin whiskers and rice straw, enhanced the mechanical properties of chitosan films, while the addition of chitin worsened overall mechanical behavior.
Rubber-like materials derived from biosourced phenolic resins

NASA Astrophysics Data System (ADS)

Amaral-Labat, G.; Grishechko, L. I.; Silva, G. F. B. Lenz e.; Kuznetsov, B. N.; Fierro, V.; Pizzi, A.; Celzard, A.

2017-07-01

The present work describes new gels derived from cheap, abundant and non-toxic wood bark extracts of phenolic nature, behaving like elastomers. Especially, we show that these materials might be used as rubber springs. Such amazing properties were obtained by a quite simple synthesis based on the autocondensation of flavonoid tannins in water at low pH in the presence of a plasticizer. After gelation and drying, the materials presented elastic properties that could be tuned from hard and brittle to quite soft and deformable, depending on the amount of plasticizer in the starting formulation. Not only the materials containing the relevant amount of plasticizer had stress-strain characteristics in quasi-static and cyclic compression similar to most commercial rubber springs, but they presented outstanding fire retardance, surviving 5 min in a flame at 1000°C in air. Neither flame propagation nor drips were noticed during the fire test, and the materials were auto-extinguishable. These excellent features make these materials potential substitutes to usual organic elastomers.
DNA-based nonlinear photonic materials

NASA Astrophysics Data System (ADS)

Heckman, Emily M.; Grote, James G.; Yaney, Perry P.; Hopkins, F. K.

2004-10-01

Deoxyribonucleic acid (DNA), extracted from salmon sperm through an enzyme isolation process, is a by-product of Japan"s fishing industry. To make DNA a suitable material for nonlinear optic (NLO) applications, it is precipitated with a surfactant complex, hexadecyltrimethlammonium chloride (CTMA). Preliminary characterization studies suggest DNA-CTMA may be a suitable host material for guest-host NLO polymer based electro-optic (EO) waveguide devices. The optical and electromagnetic properties of DNA-CTMA, as well as the development and EO measurement of a disperse red 1 (DR1) guest / DNA/CTMA host NLO material, are reported. Comparisons to a DR1 guest / poly(methyl methacrylate) (PMMA) host NLO material are made.
Modeling the mechanical properties of ultra-thin polymer films [Structural modeling of films of atomic scale thickness

DOE PAGES

Espinosa-Loza, Francisco; Stadermann, Michael; Aracne-Ruddle, Chantel; ...

2017-11-16

A modeling method to extract the mechanical properties of ultra-thin films (10–100 nm thick) from experimental data generated by indentation of freestanding circular films using a spherical indenter is presented. The relationship between the mechanical properties of the film and experimental parameters including load, and deflection are discussed in the context of a constitutive material model, test variables, and analytical approaches. As a result, elastic and plastic regimes are identified by comparison of finite element simulation and experimental data.
Modeling the mechanical properties of ultra-thin polymer films [Structural modeling of films of atomic scale thickness

DOE Office of Scientific and Technical Information (OSTI.GOV)

Espinosa-Loza, Francisco; Stadermann, Michael; Aracne-Ruddle, Chantel

A modeling method to extract the mechanical properties of ultra-thin films (10–100 nm thick) from experimental data generated by indentation of freestanding circular films using a spherical indenter is presented. The relationship between the mechanical properties of the film and experimental parameters including load, and deflection are discussed in the context of a constitutive material model, test variables, and analytical approaches. As a result, elastic and plastic regimes are identified by comparison of finite element simulation and experimental data.
Sol-gel-graphene-based fabric-phase sorptive extraction for cow and human breast milk sample cleanup for screening bisphenol A and residual dental restorative material before analysis by HPLC with diode array detection.

PubMed

Samanidou, Victoria; Filippou, Olga; Marinou, Eirini; Kabir, Abuzar; Furton, Kenneth G

2017-06-01

Fabric-phase sorptive extraction has already been recognized as a simple and green alternative to the conventional sorbent-based sorptive microextraction techniques, using hybrid organic-inorganic sorbent coatings chemically bonded to a flexible fabric surface. Herein, we have investigated the synergistic combination of the advanced material properties offered by sol-gel graphene sorbent and the simplicity of Fabric phase sorptive extraction approach in selectively extracting bisphenol A and residual monomers including bisphenol A glycerolatedimethacrylate, urethane dimethacrylate, and triethylene glycol dimethacrylate derived dental restorative materials from cow and human breast milk samples. Different coatings were evaluated. Final method development employed sol-gel graphene coated media. The main experimental parameters influencing extraction of the compounds, such as sorbent chemistry used, sample loading conditions, elution solvent, sorption stirring time, elution time, impact of protein precipitation, amount of sample, and matrix effect, were investigated and optimized. Absolute recovery values from standard solutions were 50% for bisphenol A, 78% for T triethylene glycol dimethacrylate, 110% for urethane dimethacrylate, and 103% for bisphenol A glycerolatedimethacrylate, while respective absolute recovery values from milk were 30, 52, 104, and 42%. Method validation was performed according to European Decision 657/2002/EC in terms of selectivity, sensitivity, linearity, accuracy, and precision. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Encapsulation of fluorescence vegetable extracts within a templated sol-gel matrix

NASA Astrophysics Data System (ADS)

Lacatusu, Ioana; Badea, Nicoleta; Nita, Rodica; Murariu, Alina; Miculescu, Florin; Iosub, Ion; Meghea, Aurelia

2010-04-01

The sol-gel encapsulation of labile substances with specific properties and recognition functions within robust polymer matrices remains a challenging task, despite the considerable research that has been focused on this field. Numerous studies have been reported in the field of sol-gel processes regarding different physical and chemical packing of sensitive biomolecules encapsulated in silica matrix. In this paper the classical sol-gel synthesis has been used under mild conditions in order to minimize denaturizing effects on encapsulated active vegetable extracts from flavones class. The silica templated matrix was obtained by using two types of surfactants with different alkyl chain (didodecyldimethyl-ammonium bromide and trioctadecylmetilammonium bromide) as structure-directing agents for the silicon oxide framework. An organic precursor of silicic acid (triethoxymethylsilane) has been used and it was processed by competitive hydrolysis and polycondensation reactions under controlled directions assured by the presence of oriented template. Silica materials thus obtained are used for encapsulation of two flavonoid samples containing as active principles two sources: rutin and a vegetable extract from Begonia plant. The synthesis of encapsulated nanocompounds has been achieved taking into consideration the specific interaction between the colloidal gel precursors and molecular structures of selected biomolecules. The main objective was to improve the encapsulation conditions for specific biomolecules, searching for the highest stability and functionality without loosing the quality of the flavonoid properties, particularly optical properties like fluorescence. The structural properties of the encapsulated samples have been studied by FT-IR and UV-VIS spectroscopy, thermal analysis and SEM/EDX analysis. The fluorescence experiments showed that, in the case of all four encapsulated samples, the fluorescence spectra manifest a significant increase in intensity signals, with more than 10 times for individual flavonoid and 50 times for Begonia extract. This behaviour are mainly assigned to the physical interaction of flavonoid molecules with the residual hydroxyl groups of silica, excellent synergistic properties of silica and the favourable conformation arrangement of organic molecules inside the silica network. The size distribution of synthesised polymeric silica materials have been investigated by dynamic light scattering (DLS) and optical microscopy.
Mid-Infrared Spectroscopic Properties of Humic Acid and Fulvic Acid-Soil Mixtures

USDA-ARS?s Scientific Manuscript database

The detection of humic materials in soils is essential in order to determine organic matter (SOM) stability and C sequestration on agricultural land. Mid-Infrared (MidIR) spectroscopy has been used to characterize SOM quality [1], study extracted soil humic acids [2], develop calibrations for quanti...
Mid-Infrared Spectroscopic Properties of Humic Acid and Fulvic Acid-Soil Mixtures.

USDA-ARS?s Scientific Manuscript database

The detection of humic materials in soils is essential in order to determine organic matter (SOM) stability and C sequestration on agricultural land. Mid-Infrared (MidIR) spectroscopy has been used to characterize SOM quality [1], study extracted soil humic acids [2], develop calibrations for quanti...
Preparation and properties of water and glycerol-plasticized sugar beet pulp plastics

USDA-ARS?s Scientific Manuscript database

Sugar beet pulp (SBP), the residue from sugar extraction, was compounded and turned into thermoplastic composite materials. The compounding was performed using a common twin screw compounding extruder and water and glycerol were used as plasticizers. The plasticization of SBP utilized the water-solu...
Evaluation of Antiulcer Properties of Ethanolic and Hot Aqueous Stem Extracts of Synclisia scabrida on Experimentally Induced Ulcer Models in Albino Mice

PubMed Central

Onwudiwe, TC; Ughachukwu, PO; Unekwe, PC; Ogamba, JO

2012-01-01

Background: The treatment of peptic ulcer disease poses therapeutic challenges to both patients and physicians alike because of the tendency of ulcers to relapse. Drugs used in the treatment of this disease are either costly or are associated with high incidence of adverse effects. Synclisia scabrida is a plant used in ethnomedicine for the treatment of various forms of stomach disorders and menstrual pains. The medicinal properties of the plants are claimed to reside in the roots, stems, and the leaves. Aim: This study, therefore, is to verify this claim and elucidate the probable mechanism of action by using crude stem extracts of this plant on drug- and stress-induced ulcer models in albino mice. Materials and Methods: Crude ethanol and hot water extracts, EE and HWE respectively, of the stem were prepared. These extracts were fractionated and separated by chromatographic methods and the fractions pooled together as fractions (PF-1, PF-2, PF-3 respectively) based on their chromatographic mobility and color reactions. Phytochemical analysis was done on the extracts. Ulcer models were induced in albino mice by means of indomethacin, histamine, and stress after prior cytoprotection with orally administered crude extracts and control (cimetidine). Results: Phytochemical analysis of the crude extracts and their fractions revealed the presence of cardiac glycosides (+++), tannins (+++), saponins (+), flavonoids (++), carbohydrates (++) and alkaloids (+++). Acute toxicity study on the crude extracts and their fractions revealed relative safety at the dose of 5000 mg/kg. The crude extracts (EE and HWE) and their fractions (PF-1, PF-2, PF-3) significantly (P = 0.001) protected against indomethacin-, histamine- and stress-induced ulcers. The decrease in GIT motility produced by these extracts was comparable to that produced by atropine sulfate. Conclusion: The findings suggest that these extracts of Synclisia scabrida possess antiulcer and antispasmodic properties, which justify the claims for its use in the treatment of various forms of stomach disorders. PMID:23440331
Marine Origin Polysaccharides in Drug Delivery Systems

PubMed Central

Cardoso, Matias J.; Costa, Rui R.; Mano, João F.

2016-01-01

Oceans are a vast source of natural substances. In them, we find various compounds with wide biotechnological and biomedical applicabilities. The exploitation of the sea as a renewable source of biocompounds can have a positive impact on the development of new systems and devices for biomedical applications. Marine polysaccharides are among the most abundant materials in the seas, which contributes to a decrease of the extraction costs, besides their solubility behavior in aqueous solvents and extraction media, and their interaction with other biocompounds. Polysaccharides such as alginate, carrageenan and fucoidan can be extracted from algae, whereas chitosan and hyaluronan can be obtained from animal sources. Most marine polysaccharides have important biological properties such as biocompatibility, biodegradability, and anti-inflammatory activity, as well as adhesive and antimicrobial actions. Moreover, they can be modified in order to allow processing them into various shapes and sizes and may exhibit response dependence to external stimuli, such as pH and temperature. Due to these properties, these biomaterials have been studied as raw material for the construction of carrier devices for drugs, including particles, capsules and hydrogels. The devices are designed to achieve a controlled release of therapeutic agents in an attempt to fight against serious diseases, and to be used in advanced therapies, such as gene delivery or regenerative medicine. PMID:26861358
Marine Origin Polysaccharides in Drug Delivery Systems.

PubMed

Cardoso, Matias J; Costa, Rui R; Mano, João F

2016-02-05

Oceans are a vast source of natural substances. In them, we find various compounds with wide biotechnological and biomedical applicabilities. The exploitation of the sea as a renewable source of biocompounds can have a positive impact on the development of new systems and devices for biomedical applications. Marine polysaccharides are among the most abundant materials in the seas, which contributes to a decrease of the extraction costs, besides their solubility behavior in aqueous solvents and extraction media, and their interaction with other biocompounds. Polysaccharides such as alginate, carrageenan and fucoidan can be extracted from algae, whereas chitosan and hyaluronan can be obtained from animal sources. Most marine polysaccharides have important biological properties such as biocompatibility, biodegradability, and anti-inflammatory activity, as well as adhesive and antimicrobial actions. Moreover, they can be modified in order to allow processing them into various shapes and sizes and may exhibit response dependence to external stimuli, such as pH and temperature. Due to these properties, these biomaterials have been studied as raw material for the construction of carrier devices for drugs, including particles, capsules and hydrogels. The devices are designed to achieve a controlled release of therapeutic agents in an attempt to fight against serious diseases, and to be used in advanced therapies, such as gene delivery or regenerative medicine.
Optimization of ultrasonic circulating extraction of samara oil from Acer saccharum using combination of Plackett-Burman design and Box-Behnken design.

PubMed

Chen, Fengli; Zhang, Qiang; Fei, Shimin; Gu, Huiyan; Yang, Lei

2017-03-01

In this study, ultrasonic circulating extraction (UCE) technique was firstly and successfully applied for extraction of samara oil from Acer saccharum. The extraction kinetics were fitted and described, and the extraction mechanism was discussed. Through comparison, n-hexane was selected as the extraction solvent, the influence of solvent type on the responses was detailedly interpreted based on the influence of their properties on the occurrence and intensity of cavitation. Seven parameters potentially influencing the extraction yield of samara oil and content of nervonic acid, including ultrasound irradiation time, ultrasound irradiation power, ultrasound temperature, liquid-solid ratio, soaking time, particle size and stirring rate, were screened through Plackett-Burman design to determine the significant variables. Then, three parameters performed statistically significant, including liquid-solid ratio, ultrasound irradiation time and ultrasound irradiation power, were further optimized using Box-Behnken design to predict optimum extraction conditions. Satisfactory yield of samara oil (11.72±0.38%) and content of nervonic acid (5.28±0.18%) were achieved using the optimal conditions. 1% proportion of ethanol in extraction solvent, 120°C of drying temperature and 6.4% moisture were selected and applied for effective extraction. There were no distinct differences in the physicochemical properties of samara oil obtained by UCE and Soxhlet extraction, and the samara oil obtained by UCE exhibited better antioxidant activities. Therefore, UCE method has enormous potential for efficient extraction of edible oil with high quality from plant materials. Copyright Â© 2016 Elsevier B.V. All rights reserved.
Development of polylactic acid nanocomposite films reinforced with cellulose nanocrystals derived from coffee silverskin.

PubMed

Sung, Soo Hyun; Chang, Yoonjee; Han, Jaejoon

2017-08-01

Bio-nanocomposite films based on polylactic acid (PLA) matrix reinforced with cellulose nanocrystals (CNCs) were developed using a twin-screw extruder. The CNCs were extracted from coffee silverskin (CS), which is a by-product of the coffee roasting process. They were extracted by alkali treatment followed by sulfuric acid hydrolysis. They were used as reinforcing agents to obtain PLA/CNC nanocomposites by addition at different concentrations (1%, 3%, and 5% CNCs). Morphological, tensile, and barrier properties of the bio-nanocomposites were analyzed. The tensile strength and Young's modulus increased with both 1% and 3% CNCs. The water vapor permeability decreased gradually with increasing addition of CNCs up to 3% and good oxygen barrier properties were found for all nanocomposites. These results suggest that CNCs from CS can improve the physical properties of PLA-based biopolymer film. The developed PLA/CNC bio-nanocomposite films can potentially be used for biopolymer materials with enhanced barrier and mechanical properties. Copyright © 2017 Elsevier Ltd. All rights reserved.
Combining the AFLOW GIBBS and elastic libraries to efficiently and robustly screen thermomechanical properties of solids

NASA Astrophysics Data System (ADS)

Toher, Cormac; Oses, Corey; Plata, Jose J.; Hicks, David; Rose, Frisco; Levy, Ohad; de Jong, Maarten; Asta, Mark; Fornari, Marco; Buongiorno Nardelli, Marco; Curtarolo, Stefano

2017-06-01

Thorough characterization of the thermomechanical properties of materials requires difficult and time-consuming experiments. This severely limits the availability of data and is one of the main obstacles for the development of effective accelerated materials design strategies. The rapid screening of new potential materials requires highly integrated, sophisticated, and robust computational approaches. We tackled the challenge by developing an automated, integrated workflow with robust error-correction within the AFLOW framework which combines the newly developed "Automatic Elasticity Library" with the previously implemented GIBBS method. The first extracts the mechanical properties from automatic self-consistent stress-strain calculations, while the latter employs those mechanical properties to evaluate the thermodynamics within the Debye model. This new thermoelastic workflow is benchmarked against a set of 74 experimentally characterized systems to pinpoint a robust computational methodology for the evaluation of bulk and shear moduli, Poisson ratios, Debye temperatures, Grüneisen parameters, and thermal conductivities of a wide variety of materials. The effect of different choices of equations of state and exchange-correlation functionals is examined and the optimum combination of properties for the Leibfried-Schlömann prediction of thermal conductivity is identified, leading to improved agreement with experimental results than the GIBBS-only approach. The framework has been applied to the AFLOW.org data repositories to compute the thermoelastic properties of over 3500 unique materials. The results are now available online by using an expanded version of the REST-API described in the Appendix.

Biodegradable packaging materials conception based on starch and polylactic acid (PLA) reinforced with cellulose.

PubMed

Masmoudi, Fatma; Bessadok, Atef; Dammak, Mohamed; Jaziri, Mohamed; Ammar, Emna

2016-10-01

The plastic materials used for packaging are increasing leading to a considerable amount of undegradable solid wastes. This work deals with the reduction of conventional plastics waste and the natural resources preservation by using cellulosic polymers from renewable resources (alfa and luffa). Plasticized starch films syntheses were achieved at a laboratory scale. These natural films showed some very attractive mechanical properties at relatively low plasticizers levels (12 to 17 % by weight). Furthermore, mixtures including polylactic acid polymer (PLA) and cellulose fibers extracted from alfa and luffa were investigated by melt extrusion technique. When used at a rate of 10 %, these fibers improved the mixture mechanical properties. Both developed materials were biodegradable, but the plasticized starch exhibited a faster biodegradation kinetic compared to the PLA/cellulose fibers. These new materials would contribute to a sustainable development and a waste reduction.
Physical, chemical and antimicrobial characterization of copper-bearing material

NASA Astrophysics Data System (ADS)

Li, Bowen; Hwang, Jiann-Yang; Drelich, Jaroslaw; Popko, Domenic; Bagley, Susan

2010-12-01

Arsenic, cadmium, copper, mercury, silver, and zinc are elements with strong antimicrobial properties. Among them, copper is more environmentally friendly and has both good antibacterial and antifungal properties. It has been shown that copper can even be effective against new viruses such as avian influenza (H5N1). Development of copper-bearing materials for various applications, therefore, is receiving increased attention. The Keweenaw Peninsula of Michigan was the largest native copper mining regions of North America at the turn of the 20th century. Copper was extracted by mining the copper-rich basaltic rock, and steamdriven stamp mills were used to process a great volume of low-grade ores, resulting in huge amounts of crushed waste ore called stamp sands. Approximately 500 million tons of stamp sand were discarded. This material is investigated in this study as an example for the development of antimicrobial materials.
Micromechanical Modeling of Storage Particles in Lithium Ion Batteries

NASA Astrophysics Data System (ADS)

Purkayastha, Rajlakshmi Tarun

The effect of stress on storage particles within a lithium ion battery, while acknowledged, is not understood very well. In this work three non-dimensional parameters were identified which govern the stress response within a spherical storage particle. These parameters are developed using material properties such as the diffusion coefficient, particle radius, partial molar volume and Young's modulus. Stress maps are then generated for various values of these parameters for fixed rates of insertion, applying boundary conditions similar to those found in a battery. Stress and concentration profiles for various values of these parameters show the coupling between stress and concentration is magnified depending on the values of the parameters. These maps can be used for different materials, depending on the value of the dimensionless parameters. The value of maximum stress generated is calculated for extraction as well as insertion of lithium into the particle. The model was then used to study to ellipsoidal particles in order to ascertain the effect of geometry on the maximum stress within the particle. By performing a parameter study, we can identify those materials for which particular aspect ratios of ellipsoids are more beneficial, in terms of reducing stress. We find that the stress peaks at certain aspect ratios, mostly at 2 and 1/ 2 . A parameter study was also performed on cubic particle. The values of maximum stresses for both insertion and extraction of lithium were plotted as contour plots. It was seen that the material parameters influenced the location of the maximum stress, with the maximum stress occurring either at the center of the edge between two faces or the point at the center of a face. Newer materials such as silicon are being touted as new lithium storage materials for batteries due to their higher capacity. Their tendency to rapidly loose capacity in a short period of time has led to a variety designs such are the use of carbon nanotubes or the use of coatings in order to mitigate the large expansion and stresses, which leads to spalling off of the material. We therefore extended the results for spherical storage particles to include the presence of an additional layer of material surrounding the storage particle. We perform a parameter study to see at which material properties are most beneficial in reducing stresses within the particle, and the results were tabulated. It was seen that thicker layers can lead to mitigation in the value of maximum stresses. A simple fracture analysis was carried out and the material parameters which would most likely cause crack growth to occur were identified. Finally an integrated 2-D model of a lithium ion battery was developed to study the mechanical stress in storage particles as a function of material properties. The effect of morphology on the stress and lithium concentration is studied for the case of extraction of lithium in terms of the previously developed non-dimensional parameters. Both, particles functioning in isolation were studied, as well as in closely-packed systems. The results show that the particle distance from the separator, in combination with the material properties of the particle, is critical in predicting the stress generated within the particle.
Isolation and Characterization of Adhesive Secretion from Cuvierian Tubules of Sea Cucumber Holothuria forskåli (Echinodermata: Holothuroidea)

PubMed Central

Baranowska, Malgorzata; Schloßmacher, Ute; McKenzie, J. Douglas; Müller, Werner E. G.; Schröder, Heinz C.

2011-01-01

The sea cucumber Holothuria forskåli possesses a specialized system called Cuvierian tubules. During mechanical stimulation white filaments (tubules) are expelled and become sticky upon contact with any object. We isolated a protein with adhesive properties from protein extracts of Cuvierian tubules from H. forskåli. This protein was identified by antibodies against recombinant precollagen D which is located in the byssal threads of the mussel Mytilus galloprovincialis. To find out the optimal procedure for extraction and purification, the identified protein was isolated by several methods, including electroelution, binding to glass beads, immunoprecipitation, and gel filtration. Antibodies raised against the isolated protein were used for localization of the adhesive protein in Cuvierian tubules. Immunostaining and immunogold electron microscopical studies revealed the strongest immunoreactivity in the mesothelium; this tissue layer is involved in adhesion. Adhesion of Cuvierian tubule extracts was measured on the surface of various materials. The extracted protein showed the strongest adhesion to Teflon surface. Increased adhesion was observed in the presence of potassium and EDTA, while cadmium caused a decrease in adhesion. Addition of antibodies and trypsin abolished the adhesive properties of the extract. PMID:22013488
Development of new composite biosorbents from olive pomace wastes

NASA Astrophysics Data System (ADS)

Pagnanelli, Francesca; Viggi, Carolina Cruz; Toro, Luigi

2010-06-01

In this study olive pomace was used as a source of binding substances for the development of composite biosorbents to be used in heavy metal removal from aqueous solutions. The aim was to obtain biosorbent material with an increased concentration of binding sites. The effects of two different extraction procedures (one using only methanol and the other one hexane followed by methanol) on the binding properties of olive pomace were tested by potentiometric titrations and batch biosorption tests for copper and cadmium removal. Titration modelling evidenced that both kinds of extractions generated a solid with a reduced amount of protonatable sites. Biosorption tests were organized according to full factorial designs. Analysis of variance denoted that both kinds of extractions determined a statistically significant negative effect on metal biosorption. In the case of cadmium extractions also determined a significant decrease of selectivity with respect to olive pomace. When the acid-base and binding properties of the substances extracted were determined, they were adsorbed onto a synthetic resin (octadecylsilane) and calcium alginate beads. In this way two kinds of composite biosorbents have been obtained both having an increased concentration of binding substances with respect to native olive pomace, also working more efficiently in metal removal.
Optimization of microwave-assisted extraction of polyphenols from Myrtus communis L. leaves.

PubMed

Dahmoune, Farid; Nayak, Balunkeswar; Moussi, Kamal; Remini, Hocine; Madani, Khodir

2015-01-01

Phytochemicals, such as phenolic compounds, are of great interest due to their health-benefitting antioxidant properties and possible protection against inflammation, cardiovascular diseases and certain types of cancer. Maximum retention of these phytochemicals during extraction requires optimised process parameter conditions. A microwave-assisted extraction (MAE) method was investigated for extraction of total phenolics from Myrtus communis leaves. The total phenolic capacity (TPC) of leaf extracts at optimised MAE conditions was compared with ultrasound-assisted extraction (UAE) and conventional solvent extraction (CSE). The influence of extraction parameters including ethanol concentration, microwave power, irradiation time and solvent-to-solid ratio on the extraction of TPC was modeled by using a second-order regression equation. The optimal MAE conditions were 42% ethanol concentration, 500 W microwave power, 62 s irradiation time and 32 mL/g solvent to material ratio. Ethanol concentration and liquid-to-solid ratio were the significant parameters for the extraction process (p<0.01). Under the MAE optimised conditions, the recovery of TPC was 162.49 ± 16.95 mg gallic acidequivalent/gdry weight(DW), approximating the predicted content (166.13 mg GAE/g DW). When bioactive phytochemicals extracted from Myrtus leaves using MAE compared with UAE and CSE, it was also observed that tannins (32.65 ± 0.01 mg/g), total flavonoids (5.02 ± 0.05 mg QE/g) and antioxidant activities (38.20 ± 1.08 μg GAE/mL) in MAE extracts were higher than the other two extracts. These findings further illustrate that extraction of bioactive phytochemicals from plant materials using MAE method consumes less extraction solvent and saves time. Copyright © 2014 Elsevier Ltd. All rights reserved.
Neural network approach for characterizing structural transformations by X-ray absorption fine structure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Timoshenko, Janis; Frenkel, Anatoly I.; Cintins, Arturs

The knowledge of coordination environment around various atomic species in many functional materials provides a key for explaining their properties and working mechanisms. Many structural motifs and their transformations are difficult to detect and quantify in the process of work (operando conditions), due to their local nature, small changes, low dimensionality of the material, and/or extreme conditions. Here we use artificial neural network approach to extract the information on the local structure and its in-situ changes directly from the X-ray absorption fine structure spectra. We illustrate this capability by extracting the radial distribution function (RDF) of atoms in ferritic andmore » austenitic phases of bulk iron across the temperature-induced transition. Integration of RDFs allows us to quantify the changes in the iron coordination and material density, and to observe the transition from body-centered to face-centered cubic arrangement of iron atoms. Furthermore, this method is attractive for a broad range of materials and experimental conditions« less
Neural network approach for characterizing structural transformations by X-ray absorption fine structure

DOE PAGES

Timoshenko, Janis; Frenkel, Anatoly I.; Cintins, Arturs; ...

2018-05-25

The knowledge of coordination environment around various atomic species in many functional materials provides a key for explaining their properties and working mechanisms. Many structural motifs and their transformations are difficult to detect and quantify in the process of work (operando conditions), due to their local nature, small changes, low dimensionality of the material, and/or extreme conditions. Here we use artificial neural network approach to extract the information on the local structure and its in-situ changes directly from the X-ray absorption fine structure spectra. We illustrate this capability by extracting the radial distribution function (RDF) of atoms in ferritic andmore » austenitic phases of bulk iron across the temperature-induced transition. Integration of RDFs allows us to quantify the changes in the iron coordination and material density, and to observe the transition from body-centered to face-centered cubic arrangement of iron atoms. Furthermore, this method is attractive for a broad range of materials and experimental conditions« less
Neural Network Approach for Characterizing Structural Transformations by X-Ray Absorption Fine Structure Spectroscopy

NASA Astrophysics Data System (ADS)

Timoshenko, Janis; Anspoks, Andris; Cintins, Arturs; Kuzmin, Alexei; Purans, Juris; Frenkel, Anatoly I.

2018-06-01

The knowledge of the coordination environment around various atomic species in many functional materials provides a key for explaining their properties and working mechanisms. Many structural motifs and their transformations are difficult to detect and quantify in the process of work (operando conditions), due to their local nature, small changes, low dimensionality of the material, and/or extreme conditions. Here we use an artificial neural network approach to extract the information on the local structure and its in situ changes directly from the x-ray absorption fine structure spectra. We illustrate this capability by extracting the radial distribution function (RDF) of atoms in ferritic and austenitic phases of bulk iron across the temperature-induced transition. Integration of RDFs allows us to quantify the changes in the iron coordination and material density, and to observe the transition from a body-centered to a face-centered cubic arrangement of iron atoms. This method is attractive for a broad range of materials and experimental conditions.
An elegant route to overcome fundamentally-limited light extraction in AlGaN deep-ultraviolet light-emitting diodes: Preferential outcoupling of strong in-plane emission

PubMed Central

Lee, Jong Won; Kim, Dong Yeong; Park, Jun Hyuk; Schubert, E. Fred; Kim, Jungsub; Lee, Jinsub; Kim, Yong-Il; Park, Youngsoo; Kim, Jong Kyu

2016-01-01

While there is an urgent need for semiconductor-based efficient deep ultraviolet (DUV) sources, the efficiency of AlGaN DUV light-emitting diodes (LEDs) remains very low because the extraction of DUV photons is significantly limited by intrinsic material properties of AlGaN. Here, we present an elegant approach based on a DUV LED having multiple mesa stripes whose inclined sidewalls are covered by a MgF2/Al omni-directional mirror to take advantage of the strongly anisotropic transverse-magnetic polarized emission pattern of AlGaN quantum wells. The sidewall-emission-enhanced DUV LED breaks through the fundamental limitations caused by the intrinsic properties of AlGaN, thus shows a remarkable improvement in light extraction as well as operating voltage. Furthermore, an analytic model is developed to understand and precisely estimate the extraction of DUV photons from AlGaN DUV LEDs, and hence to provide promising routes for maximizing the power conversion efficiency. PMID:26935402
An elegant route to overcome fundamentally-limited light extraction in AlGaN deep-ultraviolet light-emitting diodes: Preferential outcoupling of strong in-plane emission

NASA Astrophysics Data System (ADS)

Lee, Jong Won; Kim, Dong Yeong; Park, Jun Hyuk; Schubert, E. Fred; Kim, Jungsub; Lee, Jinsub; Kim, Yong-Il; Park, Youngsoo; Kim, Jong Kyu

2016-03-01

While there is an urgent need for semiconductor-based efficient deep ultraviolet (DUV) sources, the efficiency of AlGaN DUV light-emitting diodes (LEDs) remains very low because the extraction of DUV photons is significantly limited by intrinsic material properties of AlGaN. Here, we present an elegant approach based on a DUV LED having multiple mesa stripes whose inclined sidewalls are covered by a MgF2/Al omni-directional mirror to take advantage of the strongly anisotropic transverse-magnetic polarized emission pattern of AlGaN quantum wells. The sidewall-emission-enhanced DUV LED breaks through the fundamental limitations caused by the intrinsic properties of AlGaN, thus shows a remarkable improvement in light extraction as well as operating voltage. Furthermore, an analytic model is developed to understand and precisely estimate the extraction of DUV photons from AlGaN DUV LEDs, and hence to provide promising routes for maximizing the power conversion efficiency.
Identification of material properties of orthotropic composite plate using experimental frequency response function data

NASA Astrophysics Data System (ADS)

Tam, Jun Hui; Ong, Zhi Chao; Ismail, Zubaidah; Ang, Bee Chin; Khoo, Shin Yee

2018-05-01

The demand for composite materials is increasing due to their great superiority in material properties, e.g., lightweight, high strength and high corrosion resistance. As a result, the invention of composite materials of diverse properties is becoming prevalent, and thus, leading to the development of material identification methods for composite materials. Conventional identification methods are destructive, time-consuming and costly. Therefore, an accurate identification approach is proposed to circumvent these drawbacks, involving the use of Frequency Response Function (FRF) error function defined by the correlation discrepancy between experimental and Finite-Element generated FRFs. A square E-glass epoxy composite plate is investigated under several different configurations of boundary conditions. It is notable that the experimental FRFs are used as the correlation reference, such that, during computation, the predicted FRFs are continuously updated with reference to the experimental FRFs until achieving a solution. The final identified elastic properties, namely in-plane elastic moduli, Ex and Ey, in-plane shear modulus, Gxy, and major Poisson's ratio, vxy of the composite plate are subsequently compared to the benchmark parameters as well as with those obtained using modal-based approach. As compared to the modal-based approach, the proposed method is found to have yielded relatively better results. This can be explained by the direct employment of raw data in the proposed method that avoids errors that might incur during the stage of modal extraction.
On the Materials Science of Nature's Arms Race.

PubMed

Liu, Zengqian; Zhang, Zhefeng; Ritchie, Robert O

2018-06-05

Biological material systems have evolved unique combinations of mechanical properties to fulfill their specific function through a series of ingenious designs. Seeking lessons from Nature by replicating the underlying principles of such biological materials offers new promise for creating unique combinations of properties in man-made systems. One case in point is Nature's means of attack and defense. During the long-term evolutionary "arms race," naturally evolved weapons have achieved exceptional mechanical efficiency with a synergy of effective offense and persistence-two characteristics that often tend to be mutually exclusive in many synthetic systems-which may present a notable source of new materials science knowledge and inspiration. This review categorizes Nature's weapons into ten distinct groups, and discusses the unique structural and mechanical designs of each group by taking representative systems as examples. The approach described is to extract the common principles underlying such designs that could be translated into man-made materials. Further, recent advances in replicating the design principles of natural weapons at differing lengthscales in artificial materials, devices and tools to tackle practical problems are revisited, and the challenges associated with biological and bioinspired materials research in terms of both processing and properties are discussed. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Multifunctional (Nano)Composite Materials for Energy Storage: Towards Flexible Load-Bearing Batteries and Supercapacitors

DTIC Science & Technology

2012-08-01

e.g. large volume changes during insertion/extraction of ions and/or low electrical and ionic conductivity)  Rational design of carbon -containing...to ~ 200 mAh/g, particularly for high power cells • If graphite is replaced with Carbon fibers or CNTs, the mechanical properties of the CNT will...rigid spherical granules Annealed carbon black (CB) 100 nm Si Magasinski, A. et. al, Nature Materials, 2010, 9, 353 • Uniformity of the
DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Yongsoo; Chen, Chien-Chun; Scott, M. C.

Perfect crystals are rare in nature. Real materials often contain crystal defects and chemical order/disorder such as grain boundaries, dislocations, interfaces, surface reconstructions and point defects. Such disruption in periodicity strongly affects material properties and functionality. Despite rapid development of quantitative material characterization methods, correlating three-dimensional (3D) atomic arrangements of chemical order/disorder and crystal defects with material properties remains a challenge. On a parallel front, quantum mechanics calculations such as density functional theory (DFT) have progressed from the modelling of ideal bulk systems to modelling ‘real’ materials with dopants, dislocations, grain boundaries and interfaces; but these calculations rely heavily onmore » average atomic models extracted from crystallography. To improve the predictive power of first-principles calculations, there is a pressing need to use atomic coordinates of real systems beyond average crystallographic measurements. Here we determine the 3D coordinates of 6,569 iron and 16,627 platinum atoms in an iron-platinum nanoparticle, and correlate chemical order/disorder and crystal defects with material properties at the single-atom level. We identify rich structural variety with unprecedented 3D detail including atomic composition, grain boundaries, anti-phase boundaries, anti-site point defects and swap defects. We show that the experimentally measured coordinates and chemical species with 22 picometre precision can be used as direct input for DFT calculations of material properties such as atomic spin and orbital magnetic moments and local magnetocrystalline anisotropy. The work presented here combines 3D atomic structure determination of crystal defects with DFT calculations, which is expected to advance our understanding of structure–property relationships at the fundamental level.« less
Evaluation of subcutaneous and alveolar implantation surgical sites in the study of the biological properties of root-end filling endodontic materials

PubMed Central

CINTRA, Luciano Tavares Angelo; BERNABÉ, Pedro Felício Estrada; de MORAES, Ivaldo Gomes; GOMES-FILHO, João Eduardo; OKAMOTO, Tetuo; CONSOLARO, Alberto; PINHEIRO, Tiago Novaes

2010-01-01

Objective The aim of this study was to compare two methodologies used in the evaluation of tissue response to root-end filling materials in rats. Material and Methods Forty rats were divided into 4 groups: in Groups I and II (control groups), empty polyethylene tubes were implanted in the extraction site and in the subcutaneous tissue, respectively; in Groups III and IV, polyethylene tubes filled with ProRoot MTA were implanted in the extraction site and in the subcutaneous tissue, respectively. The animals were killed 7 and 30 days after tube implantation, and the hemi-maxillas and the capsular subcutaneous tissue, both with the tubes, were removed. Specimens were processed and evaluated histomorphologicaly under light microscopy. The scores obtained were analyzed statistically by the Kruskal-Wallis test (p<0.05). Results There were no statistically significant differences between the implantation methods (p=0.78033, p=0.72039). It was observed that the 30-day groups presented a more mature healing process due to smaller number of inflammatory cells. Conclusion The present study showed no differences in tissue responses as far as the implantation site and the studied period were concerned. Alveolar socket implantation methodology represents an interesting method in the study of the biological properties of root-end filling endodontic materials due to the opportunity to evaluate bone tissue response. PMID:20379685
Isolation, Separation, and Preconcentration of Biologically Active Compounds from Plant Matrices by Extraction Techniques.

PubMed

Raks, Victoria; Al-Suod, Hossam; Buszewski, Bogusław

2018-01-01

Development of efficient methods for isolation and separation of biologically active compounds remains an important challenge for researchers. Designing systems such as organomineral composite materials that allow extraction of a wide range of biologically active compounds, acting as broad-utility solid-phase extraction agents, remains an important and necessary task. Selective sorbents can be easily used for highly selective and reliable extraction of specific components present in complex matrices. Herein, state-of-the-art approaches for selective isolation, preconcentration, and separation of biologically active compounds from a range of matrices are discussed. Primary focus is given to novel extraction methods for some biologically active compounds including cyclic polyols, flavonoids, and oligosaccharides from plants. In addition, application of silica-, carbon-, and polymer-based solid-phase extraction adsorbents and membrane extraction for selective separation of these compounds is discussed. Potential separation process interactions are recommended; their understanding is of utmost importance for the creation of optimal conditions to extract biologically active compounds including those with estrogenic properties.
Active and smart biodegradable packaging based on starch and natural extracts.

PubMed

Medina-Jaramillo, Carolina; Ochoa-Yepes, Oswaldo; Bernal, Celina; Famá, Lucía

2017-11-15

Active and smart biodegradable films from cassava starch and glycerol with 5wt.% of different natural extracts such as green tea and basil were obtained by casting. Their functional capacity as antioxidants and their physicochemical properties achieved from the incorporation of these types of extracts were evaluated. The content of phenolic compounds in the extracts led to films with significant antioxidant activity, being greater in the case of the system containing green tea extract. Color changes in both materials after immersion in different media (acid and basic) due to the presence of chlorophyll and carotenoids in the extracts were observed, but the film with basil extract reacted most notably to the different pH. These films degraded in soil under two weeks and were thermal stable up to 240°C. Finally, the incorporation of extracts of green tea and basil led to thermoplastic starch films with lower water vapor permeability retaining their flexibility. Copyright © 2017 Elsevier Ltd. All rights reserved.
Optimization extraction of polysaccharide from Tunisian Zizyphus lotus fruit by response surface methodology: Composition and antioxidant activity.

PubMed

Mkadmini Hammi, Khaoula; Hammami, Majdi; Rihouey, Christophe; Le Cerf, Didier; Ksouri, Riadh; Majdoub, Hatem

2016-12-01

Response surface methodology using a Box-Behnken design was employed to optimize extraction temperature, extraction time and ratio of water to material to obtain a maximum polysaccharide yield with high uronic acid content and antioxidant property from edible Zizyphus lotus fruit. The optimal conditions were: extraction time of 3h 15min, extraction temperature of 91.2°C and water to solid ratio of 39mL/g. Under these conditions, the experimental extraction yield, uronic acid content and 2,2-diphenyl-1-picrylhydrazyl scavenging ability (IC50) were 18.88%, 41.89 and 0.518mg/mL, respectively. Chemical analysis revealed that the extract was composed of 97.92% carbohydrate of which 41.89% is uronic acid. The extracted polysaccharides, with an average molecular weight of 2720kDa, are composed of arabinose, rhamnose, glucose, fructose, galactose and xylose. Moreover, the polysaccharides exhibited a significant reducing power and anti-lipid peroxidation activities. Copyright © 2016 Elsevier Ltd. All rights reserved.
Mechanical property characterization of bilayered tablets using nondestructive air-coupled acoustics.

PubMed

Akseli, Ilgaz; Dey, Dipankar; Cetinkaya, Cetin

2010-03-01

A noncontact/nondestructive air-coupled acoustic technique to be potentially used in mechanical property determination of bilayer tablets is presented. In the reported experiments, a bilayer tablet is vibrated via an acoustic field of an air-coupled transducer in a frequency range sufficiently high to excite several vibrational modes (harmonics) of the tablet. The tablet vibrational transient responses at a number of measurement points on the tablet are acquired by a laser vibrometer in a noncontact manner. An iterative computational procedure based on the finite element method is utilized to extract the Young's modulus, the Poisson's ratio, and the mass density values of each layer material of a bilayer tablet from a subset of the measured resonance frequencies. For verification purposes, a contact ultrasonic technique based on the time-of-flight data of the longitudinal (pressure) and transverse (shear) acoustic waves in each layer of a bilayer tablet is also utilized. The extracted mechanical properties from the air-coupled acoustic data agree well with those determined from the contact ultrasonic measurements. The mechanical properties of solid oral dosage forms have been shown to impact its mechanical integrity, disintegration profile and the release rate of the drug in the digestive tract, thus potentially affecting its therapeutic response. The presented nondestructive technique provides greater insight into the mechanical properties of the bilayer tablets and has the potential to identify quality and performance problems related to the mechanical properties of the bilayer tablets early on the production process and, consequently, reduce associated cost and material waste.

Ulcer healing activity of Mumijo aqueous extract against acetic acid induced gastric ulcer in rats

PubMed Central

Shahrokhi, Nader; Keshavarzi, Zakieh; Khaksari, Mohammad

2015-01-01

Objective: Gastric ulcer is an important clinical problem, chiefly due to extensive use of some drugs. The aim was to assess the activity of Mumijo extract (which is used in traditional medicine) against acetic acid induced gastric ulcer in rats. Materials and Methods: The aqueous extract of Mumijo was prepared. Animals were randomly (n = 10) divided into four groups: Control, sham-operated group (received 0.2 ml of acetic acid to induce gastric ulcer), Mumijo (100 mg/kg/daily) were given for 4 days postacetic acid administration, and ranitidine group (20 mg/kg). The assessed parameters were pH and pepsin levels (by Anson method) of gastric contents and gastric histopathology. Ranitidine was used as reference anti-ulcer drug. Results: The extract (100 mg/kg/daily, p.o.) inhibited acid acetic-induced gastric ulceration by elevating its pH versus sham group (P < 0.01) and decreasing the pepsin levels compared to standard drug, ranitidine (P < 0.05). The histopathology data showed that the treatment with Mumijo extract had a significant protection against all mucosal damages. Conclusion: Mumijo extract has potent antiulcer activity. Its anti-ulcer property probably acts via a reduction in gastric acid secretion and pepsin levels. The obtained results support the use of this herbal material in folk medicine. PMID:25709338
Nutritional Composition and Phytochemical, Antioxidative, and Antifungal Activities of Pergularia tomentosa L.

PubMed Central

Belghith, Hafedh; Ben Abdallah, Ferjani; Belghith, Karima

2017-01-01

Crude extracts from a medicinal Tunisian plant, Pergularia tomentosa L., were the investigated natural material. Butanolic extract of roots analyzed with IR spectra revealed the presence of hydroxyl, alcoholic, and carboxylic groups and sugars units. Analysis of some secondary metabolites, total phenolic, flavonoids, flavonols, and procyanidins, was performed using different solvents following the increased gradient of polarity. Fruits and leaves contained the highest amounts of all these compounds. Antioxidant properties were evaluated by the determination of free radical scavenging activity and the reducing power of methanolic extracts. Fruits and leaf extracts were the most powerful antioxidants for the two-assay in vitro system. Stems and fruits extracts exhibit an antifungal activity against Fusarium oxysporum f. sp. lycopersici which could become an alternative to synthetic fungicide to control Solanum species fungal diseases. PMID:28409159
Ag-protein plasmonic architectures for surface plasmon-coupled emission enhancements and Fabry-Perot mode-coupled directional fluorescence emission

NASA Astrophysics Data System (ADS)

Badiya, Pradeep Kumar; Patnaik, Sai Gourang; Srinivasan, Venkatesh; Reddy, Narendra; Manohar, Chelli Sai; Vedarajan, Raman; Mastumi, Noriyoshi; Belliraj, Siva Kumar; Ramamurthy, Sai Sathish

2017-10-01

We report the use of silver decorated plant proteins as spacer material for augmented surface plasmon-coupled emission (120-fold enhancement) and plasmon-enhanced Raman scattering. We extracted several proteins from different plant sources [Triticum aestivum (TA), Aegle marmelos (AM), Ricinus communis (RC), Jatropha curcas (JC) and Simarouba glauca (SG)] followed by evaluation of their optical properties and simulations to rationalize observed surface plasmon resonance. Since the properties exhibited by protein thin films is currently gaining research interest, we have also carried out simulation studies with Ag-protein biocomposites as spacer materials in metal-dielectric-metal planar microcavity architecture for guided emission of Fabry-Perot mode-coupled fluorescence.
Inverse finite element methods for extracting elastic-poroviscoelastic properties of cartilage and other soft tissues from indentation

NASA Astrophysics Data System (ADS)

Namani, Ravi

Mechanical properties are essential for understanding diseases that afflict various soft tissues, such as osteoarthritic cartilage and hypertension which alters cardiovascular arteries. Although the linear elastic modulus is routinely measured for hard materials, standard methods are not available for extracting the nonlinear elastic, linear elastic and time-dependent properties of soft tissues. Consequently, the focus of this work is to develop indentation methods for soft biological tissues; since analytical solutions are not available for the general context, finite element simulations are used. First, parametric studies of finite indentation of hyperelastic layers are performed to examine if indentation has the potential to identify nonlinear elastic behavior. To answer this, spherical, flat-ended conical and cylindrical tips are examined and the influence of thickness is exploited. Also the influence of the specimen/substrate boundary condition (slip or non-slip) is clarified. Second, a new inverse method---the hyperelastic extraction algorithm (HPE)---was developed to extract two nonlinear elastic parameters from the indentation force-depth data, which is the basic measurement in an indentation test. The accuracy of the extracted parameters and the influence of noise in measurements on this accuracy were obtained. This showed that the standard Berkovitch tip could only extract one parameter with sufficient accuracy, since the indentation force-depth curve has limited sensitivity to both nonlinear elastic parameters. Third, indentation methods for testing tissues from small animals were explored. New methods for flat-ended conical tips are derived. These account for practical test issues like the difficulty in locating the surface or soft specimens. Also, finite element simulations are explored to elucidate the influence of specimen curvature on the indentation force-depth curve. Fourth, the influence of inhomogeneity and material anisotropy on the extracted "average" linear elastic modulus was studied. The focus here is on murine tibial cartilage, since recent experiments have shown that the modulus measured by a 15 mum tip is considerably larger than that obtained from a 90 mum tip. It is shown that a depth-dependent modulus could give rise to such a size effect. Lastly, parametric studies were performed within the small strain setting to understand the influence of permeability and viscoelastic properties on the indentation stress-relaxation response. The focus here is on cartilage, and specific test protocols (single-step vs. multi-step stress relaxation) are explored. An inverse algorithm was developed to extract the poroviscoelastic parameters. A sensitivity study using this algorithm shows that the instantaneous elastic modulus (which is a measure of the viscous relaxation) can be extracted with very good accuracy, but the permeability and long-time relaxation constant cannot be extracted with good accuracy. The thesis concludes with implications of these studies. The potential and limitations of indentation tests for studying cartilage and other soft tissues is discussed.
Evaluation of Antioxidant, Antimicrobial, and Antiurolithiatic Potential of Different Solvent Extracts of Aerva lanata Linn Flowers

PubMed Central

Behera, Padma Charan; Ghosh, Manik

2018-01-01

Introduction: Aerva lanata (Linn) of family Amaranthaceae is an important and commonly used plant for its medicinal and pharmacological properties and proving the traditional uses of flowers of A. lanata Linn. Objective: All extracts of A. lanata were further evaluated for antioxidant, antimicrobial, and antiurolithiatic potential to scientifically prove the traditional uses. Materials and Methods: In the present investigation, different solvent extracts of flowers were obtained using a Soxhlet extractor. Microorganisms were obtained from IMTECH, Chandigarh. Antiurolithiatic study was carried out in Albino Research and Training Centre, Hyderabad. Results: Regardless of the antioxidant studied, the methanolic extract presented the highest antioxidant activity and the aqueous extracts offered the lowest, following the order: methanolic extract > ethyl acetate > chloroform > aqueous. The results of this antimicrobial study indicate that methanolic extract of A. lanata could be used as antimicrobial agents. Overall, the methanolic flower extract of A. lanata (Linn) was significantly more promising as antiurolithiatic spectrum. This result also suggested the potential usefulness of the methanolic extract as an antiurolithiatic agent. Conclusion: Henceforward, this research can be acknowledged as a prime new report that focuses on the application of A. lanata (Linn) as an antioxidant, antimicrobial, and antiurolithiatic agent. SUMMARY Overall, methanolic flower extract of Aerva lanata Linn showed promising antioxidant activityAdditionally, methanolic flower extract of A. lanata Linn exhibited remarkable antimicrobial and antiurolithiatic potential. Abbreviations used: IMTECH Chandigarh: Institute of Microbial Technology, Chandigarh; IMMT: Institute of Mineral and Material Technology; CSIR: Council of Scientific & Industrial Research; DPPH: 1,1-diphenyl-2-picrylhydrazyl; MTCC: Microbial Type Culture Collection; BHT: Butylated Hydroxyl Toluene. PMID:29576701
Effective conductivity of wire mesh reflectors for space deployable antenna systems

NASA Technical Reports Server (NTRS)

Davis, William A.

1994-01-01

This report summarizes efforts to characterize the measurement of conductive mesh and smooth surfaces using proximity measurements for a dielectric resonator. The resonator operates in the HEM11 mode and is shown to have an evanescent field behavior in the vicinity of the sample surface, raising some question to the validity of measurements requiring near normal incidence on the material. In addition, the slow radial field decay outside of the dielectric resonator validates the sensitivity to the planar supporting structure and potential radiation effects. Though these concerns become apparent along with the sensitivity to the gap between the dielectric and the material surface, the basic concept of the material measurement using dielectric resonators has been verified for useful comparison of material surface properties. The properties, particularly loss, may be obtained by monitoring the resonant frequency along with the resonator quality factor (Q), 3 dB bandwidth, or the midband transmission amplitude. Comparison must be made to known materials to extract the desired data.
Therapeutic Significance of Loligo vulgaris (Lamarck, 1798) ink Extract: A Biomedical Approach

PubMed Central

Nadarajah, Sri Kumaran; Vijayaraj, Radha; Mani, Jayaprakashvel

2017-01-01

Background: The squid ink extract is well known for its biomedical properties. Objective: In this study, squid Loligo vulgaris was collected from Tuticorin costal water, Bay of Bengal, India. Materials and Methods: Proximate composition of the crude squid ink was studied and found to have protein as the major component over lipid and carbohydrates. Further, bioactive fractions of squid ink were extracted with ethanol, and therapeutic applications such as hemolytic, antioxidant, antimicrobial, and in vitro anti-inflammatory properties were analyzed using standard methods. Results: In hemolytic assay, the squid ink extract exhibited a maximum hemolytic activity of 128 hemolytic unit against tested erythrocytes. In DPPH assay, the ethanolic extract of squid ink has exhibited an antioxidant activity of 83.5%. The squid ink was found to be potent antibacterial agent against the pathogens tested. 200 μL of L. vulgaris ink extract showed remarkable antibacterial activity as zone of inhibition against Escherichia coli (28 mm), Klebsiella pneumoniae (22 mm), Pseudomonas aeruginosa (21 mm), and Staphylococcus aureus (24 mm). The 68.9% inhibition of protein denaturation by the squid ink extract indicated that it has very good in vitro anti-inflammatory properties. The Fourier transform infrared spectroscopy analysis of the ethanolic extracts of the squid ink indicated the presence of functional groups such as 1° and 2° amines, amides, alkynes (terminal), alkenes, aldehydes, nitriles, alkanes, aliphatic amines, carboxylic acids, and alkyl halides, which complements the biochemical background of therapeutic applications. Conclusion: Hence, results of this study concluded that the ethanolic extract of L. vulgaris has many therapeutic applications such as antimicrobial, antioxidant, and anti-inflammatory activities. SUMMARY Squid ink is very high in a number of important nutrients. It’s particularly high in antioxidants for instance, which as well all know help to protect the cells and the heart against damage from free radicals. In the present study, the squid ink have antioxidant, anti-inflammatory and cytotoxic properties and can be considered as promising the developing the drugs. Abbreviations Used: DPPH: 2,2-diphenyl-1-picrylhydrazyl, FTIR: Fourier-transform infrared spectroscopy, BSA: Bovine Serum Albumin PMID:29333051
Parameter estimation of a nonlinear Burger's model using nanoindentation and finite element-based inverse analysis

NASA Astrophysics Data System (ADS)

Hamim, Salah Uddin Ahmed

Nanoindentation involves probing a hard diamond tip into a material, where the load and the displacement experienced by the tip is recorded continuously. This load-displacement data is a direct function of material's innate stress-strain behavior. Thus, theoretically it is possible to extract mechanical properties of a material through nanoindentation. However, due to various nonlinearities associated with nanoindentation the process of interpreting load-displacement data into material properties is difficult. Although, simple elastic behavior can be characterized easily, a method to characterize complicated material behavior such as nonlinear viscoelasticity is still lacking. In this study, a nanoindentation-based material characterization technique is developed to characterize soft materials exhibiting nonlinear viscoelasticity. Nanoindentation experiment was modeled in finite element analysis software (ABAQUS), where a nonlinear viscoelastic behavior was incorporated using user-defined subroutine (UMAT). The model parameters were calibrated using a process called inverse analysis. In this study, a surrogate model-based approach was used for the inverse analysis. The different factors affecting the surrogate model performance are analyzed in order to optimize the performance with respect to the computational cost.
Keratin: dissolution, extraction and biomedical application.

PubMed

Shavandi, Amin; Silva, Tiago H; Bekhit, Adnan A; Bekhit, Alaa El-Din A

2017-08-22

Keratinous materials such as wool, feathers and hooves are tough unique biological co-products that usually have high sulfur and protein contents. A high cystine content (7-13%) differentiates keratins from other structural proteins, such as collagen and elastin. Dissolution and extraction of keratin is a difficult process compared to other natural polymers, such as chitosan, starch, collagen, and a large-scale use of keratin depends on employing a relatively fast, cost-effective and time efficient extraction method. Keratin has some inherent ability to facilitate cell adhesion, proliferation, and regeneration of the tissue, therefore keratin biomaterials can provide a biocompatible matrix for regrowth and regeneration of the defective tissue. Additionally, due to its amino acid constituents, keratin can be tailored and finely tuned to meet the exact requirement of degradation, drug release or incorporation of different hydrophobic or hydrophilic tails. This review discusses the various methods available for the dissolution and extraction of keratin with emphasis on their advantages and limitations. The impacts of various methods and chemicals used on the structure and the properties of keratin are discussed with the aim of highlighting options available toward commercial keratin production. This review also reports the properties of various keratin-based biomaterials and critically examines how these materials are influenced by the keratin extraction procedure, discussing the features that make them effective as biomedical applications, as well as some of the mechanisms of action and physiological roles of keratin. Particular attention is given to the practical application of keratin biomaterials, namely addressing the advantages and limitations on the use of keratin films, 3D composite scaffolds and keratin hydrogels for tissue engineering, wound healing, hemostatic and controlled drug release.
Better Modeling of Electrostatic Discharge in an Insulator

NASA Technical Reports Server (NTRS)

Pekov, Mihail

2010-01-01

An improved mathematical model has been developed of the time dependence of buildup or decay of electric charge in a high-resistivity (nominally insulating) material. The model is intended primarily for use in extracting the DC electrical resistivity of such a material from voltage -vs.- current measurements performed repeatedly on a sample of the material over a time comparable to the longest characteristic times (typically of the order of months) that govern the evolution of relevant properties of the material. This model is an alternative to a prior simplistic macroscopic model that yields results differing from the results of the time-dependent measurements by two to three orders of magnitude.
Metathesis depolymerizable surfactants

DOEpatents

Jamison, Gregory M [Albuquerque, NM; Wheeler, David R [Albuquerque, NM; Loy, Douglas A [Tucson, AZ; Simmons, Blake A [San Francisco, CA; Long, Timothy M [Evanston, IL; McElhanon, James R [Manteca, CA; Rahimian, Kamyar [Albuquerque, NM; Staiger, Chad L [Albuquerque, NM

2008-04-15

A class of surfactant molecules whose structure includes regularly spaced unsaturation in the tail group and thus, can be readily decomposed by ring-closing metathesis, and particularly by the action of a transition metal catalyst, to form small molecule products. These small molecules are designed to have increased volatility and/or enhanced solubility as compared to the original surfactant molecule and are thus easily removed by solvent extraction or vacuum extraction at low temperature. By producing easily removable decomposition products, the surfactant molecules become particularly desirable as template structures for preparing meso- and microstructural materials with tailored properties.
Silver Nanoparticles Synthesized Using Mint Extract and their Application in Chitosan/Gelatin Composite Packaging Film

NASA Astrophysics Data System (ADS)

Bhoir, Shraddha A.; Chawla, S. P.

The present study reports synthesis of silver nanoparticles (AgNPs) using mint extract (ME) in the presence of polyvinyl alcohol (PVA) as capping material. PVA, ME and silver nitrate at concentration of 1%, 0.01% and 0.02%, respectively were found to be optimum for the synthesis of nanoparticles. The formation of AgNPs was confirmed by measuring surface plasmon resonance (SPR) peak. The intensity of SPR peak remained unaltered thus suggesting stability of colloid without aggregation during storage. The nanoparticles inhibited the growth of food borne bacteria namely Escherichia coli, Pseudomonas aeruginosa and Bacillus cereus. The incorporation of these nanoparticles in chitosan and gelatin blend resulted in homogenous films. Mechanical properties and water vapor transmission rate of chitosan-gelatin films improved due to addition of AgNPs, whereas optical (opacity and UV light transmittance) and oxygen permeability properties remained unchanged. These films had the ability to inhibit growth of 5 log CFU of the above test organisms. These findings suggest that the AgNPs obtained by reduction of silver by ME can be effectively utilized to prepare antibacterial eco-friendly food packaging material.
Quantification of the predominant monomeric catechins in baking chocolate standard reference material by LC/APCI-MS.

PubMed

Nelson, Bryant C; Sharpless, Katherine E

2003-01-29

Catechins are polyphenolic plant compounds (flavonoids) that may offer significant health benefits to humans. These benefits stem largely from their anticarcinogenic, antioxidant, and antimutagenic properties. Recent epidemiological studies suggest that the consumption of flavonoid-containing foods is associated with reduced risk of cardiovascular disease. Chocolate is a natural cocoa bean-based product that reportedly contains high levels of monomeric, oligomeric, and polymeric catechins. We have applied solid-liquid extraction and liquid chromatography coupled with atmospheric pressure chemical ionization-mass spectrometry to the identification and determination of the predominant monomeric catechins, (+)-catechin and (-)-epicatechin, in a baking chocolate Standard Reference Material (NIST Standard Reference Material 2384). (+)-Catechin and (-)-epicatechin are detected and quantified in chocolate extracts on the basis of selected-ion monitoring of their protonated [M + H](+) molecular ions. Tryptophan methyl ester is used as an internal standard. The developed method has the capacity to accurately quantify as little as 0.1 microg/mL (0.01 mg of catechin/g of chocolate) of either catechin in chocolate extracts, and the method has additionally been used to certify (+)-catechin and (-)-epicatechin levels in the baking chocolate Standard Reference Material. This is the first reported use of liquid chromatography/mass spectrometry for the quantitative determination of monomeric catechins in chocolate and the only report certifying monomeric catechin levels in a food-based Standard Reference Material.
Quantification of appetite suppressing steroid glycosides from Hoodia gordonii in dried plant material, purified extracts and food products using HPLC-UV and HPLC-MS methods.

PubMed

Janssen, Hans-Gerd; Swindells, Chris; Gunning, Philip; Wang, Weijun; Grün, Christian; Mahabir, Krishna; Maharaj, Vinesh J; Apps, Peter J

2008-06-09

High-performance liquid chromatography (HPLC)-UV and HPLC-Mass Spectrometry (MS) methods were developed for the quantitative analysis of the family of Hoodia gordonii steroid glycosides with appetite suppressing properties in dried plant material, in purified and enriched extracts and in various prototype food-products fortified with H. gordonii extracts. For solid materials, e.g. dried plants or for non-fatty foods, extraction of the steroid glycosides is performed using methanol. For products where the steroid glycosides are present in an oil matrix, direct injection of the oil after dilution in tetrahydrofuran is applied. The HPLC separation is performed on an octyl-modified reversed-phase column in the gradient mode with UV detection at lambda = 220 nm. Quantification is performed against an external calibration line prepared using either one of the pure steroid glycosides or geranyl-tiglate. Short- and long-term repeatabilities of the methods are better than 3 and 6%, respectively. Recoveries are better than 85%, even in the analysis of the least abundant steroid glycosides in a complex yoghurt drink. Linearity is better than 3-4 orders of magnitude and the detection limits are below approximately 2 microg g(-1) for the individual steroid glycosides in dried plant material and food products. HPLC-MS is used to confirm that the steroid glycosides contain the characteristic steroid core, the carbohydrate chain and the tigloyl group.
Blended polymer materials extractable with supercritical carbon dioxide

NASA Astrophysics Data System (ADS)

Cai, Mei

Supercritical carbon dioxide is drawing more and more attention because of its unique solvent properties along with being environmentally friendly. Historically most of the commercial interests of supercritical carbon dioxide extraction are in the food industry, pharmaceutical industry, environmental preservation and polymer processing. Recently attention has shifted from the extraction of relatively simple molecules to more complex systems with a much broader range of physical and chemical transformations. However the available data show that a lot of commercially valuable substances are not soluble in supercritical carbon dioxide due to their polar structures. This fact really limits the application of SCF extraction technology to much broader industrial applications. Therefore, the study of a polymer's solubility in a given supercritical fluid and its thermodynamic behavior becomes one of the most important research topics. The major objective of this dissertation is to develop a convenient and economic way to enhance the polymer's solubility in supercritical carbon dioxide. Further objective is to innovate a new process of making metal casting parts with blended polymer materials developed in this study. The key technique developed in this study to change a polymer's solubility in SCF CO2 is to thermally blend a commercially available and CO2 non-soluble polymer material with a low molecular weight CO2 soluble organic chemical that acts as a co-solute. The mixture yields a plastic material that can be completely solubilized in SCF CO2 over a range of temperatures and pressures. It also exhibits a variety of physical properties (strength, hardness, viscosity, etc.) depending on variations in the mixture ratio. The three organic chemicals investigated as CO2 soluble materials are diphenyl carbonate, naphthalene, and benzophenone. Two commercial polymers, polyethylene glycol and polystyrene, have been investigated as CO2 non-soluble materials. The chemical, physical, thermal, and phase behavior of the blended polymers studied in this dissertation includes solubility in SCF CO2, the melt viscosity, the melting temperature depression, and phase equilibrium under SCF conditions. Several hypotheses are investigated to determine which mechanism plays the major role in the extraction. Finally a novel metal casting process is discussed with the materials developed in this study. This new method utilizes an adhesive or binder film composition for the purpose of building up a casting pattern of resin-bonded aggregate particles. The pattern is then encased in a conventional rigid shell mold that is not susceptible to degradation by SCF CO2. The pattern is then disintegrated within an unaffected mold by exposure to SCF CO 2. This is an efficient and low cost method of making patterns and molds, especially for the casting of a relatively low number of parts such as in prototype evaluations.
Nanostructured lipid systems modified with waste material of propolis for wound healing: Design, in vitro and in vivo evaluation.

PubMed

Rosseto, Hélen Cássia; Toledo, Lucas de Alcântara Sica de; Francisco, Lizziane Maria Belloto de; Esposito, Elisabetta; Lim, Yunsook; Valacchi, Giuseppe; Cortesi, Rita; Bruschi, Marcos Luciano

2017-10-01

Propolis, a natural compound that can accelerate the wound healing process, is mainly used as ethanolic extract. The extractive solution may also be obtained from the propolis by-product (BP), transforming this waste material into a pharmaceutical active ingredient. Even if propolis does not show toxicity, when used as an extract over harmed skin or mucosa, the present ethanol content may be harmful to the tissue recovering, besides hindering the drug release. This study describes the development of solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC) as topical propolis delivery systems and the investigation of their in vitro and in vivo activities. The extracts were evaluated to guarantee their quality, and the lipid dispersions were characterized with respect to morphology (cryo-TEM), size and diffractometry (X-ray) properties. The occlusive capacity of formulations was also evaluated by an in vitro technique, which determines the occlusion factor. The drug entrapment efficiency (EE), as well as the in vitro drug release profile from the nanoparticulate systems was investigated as well. The size analysis performed through 90days was favorable to a topical administration and the polydispersity index, though not ideal in all cases due to the high content of resins and gums from the extracts, were relatively stable for the SLN. The propolis extract contributes to the occlusive potential of the formulations. The human immortalized keratinocytes presented good cell viability when tested with both extracts (propolis and BP) freely or entrapped in the systems. SLN modified with propolis material provided an acceleration of the in vivo wound healing process. Copyright © 2017 Elsevier B.V. All rights reserved.
A review on development of solid phase microextraction fibers by sol-gel methods and their applications.

PubMed

Kumar, Ashwini; Gaurav; Malik, Ashok Kumar; Tewary, Dhananjay Kumar; Singh, Baldev

2008-03-03

Solid phase microextraction (SPME) is an innovative, solvent free technology that is fast, economical and versatile. SPME is a fiber coated with a liquid (polymer), a solid (sorbent) or a combination of both. The fiber coating takes up the compounds from the sample by absorption in the case of liquid coatings or adsorption in the case of solid coatings. The SPME fiber is then transferred with the help of a syringe like device into the analytical instrument for desorption and analysis of the target analytes. The sol-gel process provides a versatile method to prepare size, shape and charge selective materials of high purity and homogeneity by means of preparation techniques different from the traditional ones, for the chemical analysis. This review is on the current state of the art and future trends in the developments of solid phase microextraction (SPME) fibers using sol-gel method. To achieve more selective determination of different compound classes, the variety of different coating material for SPME fibers has increased. Further developments in SPME as a highly efficient extraction technique, will greatly depend on new breakthroughs in the area of new coating material developments for the SPME fibers. In sol-gel approach, appropriate sol-gel precursors and other building blocks can be selected to create a stationary phase with desired structural and surface properties. This approach is efficient in integrating the advantageous properties of organic and inorganic material systems and thereby increasing and improving the extraction selectivity of the produced amalgam organic-inorganic stationary phases. This review is mainly focused on recent advanced developments in the design, synthesis, characterisation, properties and application of sol-gel in preparation of coatings for the SPME fibers.
Analytical chemistry of PCBs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Erickson, M.D.

Analytical Chemistry of PCBs offers a review of physical, chemical, commercial, environmental and biological properties of PCBs. It also defines and discusses six discrete steps of analysis: sampling, extraction, cleanup, determination, data reduction, and quality assurance. The final chapter provides a discussion on collaborative testing - the ultimate step in method evaluation. Dr. Erickson also provides a bibliography of over 1200 references, critical reviews of primary literature, and five appendices which present ancillary material on PCB nomen-clature, physical properties, composition of commercial mixtures, mass spectra characteristics, and PGC/ECD chromatograms.
Depressed scattering across grain boundaries in single crystal graphene

NASA Astrophysics Data System (ADS)

Chen, Jiao; Jin, Zhi; Ma, Peng; Wang, Hong; Wang, Haomin; Shi, Jingyuan; Peng, Songang; Liu, Xinyu; Ye, Tianchun

2012-10-01

We investigated the electrical and quantum properties of single-crystal graphene (SCG) synthesized by chemical vapor deposition (CVD). Quantum Hall effect and Shubnikov de Hass oscillation, a distinguishing feature of a 2-dimensional electronic material system, were observed during the low temperature transport measurements. Decreased scattering from grain boundaries in SCG was proven through extracting information from weak localization theory. Our results facilitate understanding the electrical properties of SCG grown by CVD and its applications in high speed transistor and quantum devices.
Response surface modeling and optimization of ultrasound-assisted extraction of three flavonoids from tartary buckwheat (Fagopyrum tataricum)

PubMed Central

Peng, Lian-Xin; Zou, Liang; Zhao, Jiang-Lin; Xiang, Da-Bing; Zhu, Peng; Zhao, Gang

2013-01-01

Background: Buckwheat (Fagopyrum spp., Polygonaceae) is a widely planted food crop. Flavonoids, including quercetin, rutin, and kaempferol, are the main bioactive components in tartary buckwheat (Fagopyrum tataricum (L.) Gaertn). From the nutriological and pharmacological perspectives, flavonoids have great value in controlling blood glucose and blood pressure levels, and they also have antioxidant properties. Objective: To optimize the conditions for extraction of quercetin, rutin, and kaempferol from F. tataricum. Materials and Methods: A combination of ultrasound-assisted extraction (UAE) and response surface methodology (RSM) was used for flavonoid extraction and yield assessment. The RSM was based on a three-level, three-variable Box-Behnken design. Results: Flavonoids were optimally extracted from F. tataricum by using 72% methanol, at 60°C, for 21 minutes. Under these conditions, the obtained extraction yield of the total flavonoids was 3.94%. Conclusion: The results indicated that the UAE method was effective for extraction of flavonoids from tartary buckwheat. PMID:23930003

In vitro antioxidant potential of selected aphrodisiac medicinal plants.

PubMed

Riaz, M; Shahid, M; Jamil, A; Saqib, M

2017-01-01

The present study aimed to evaluate the antioxidant activity of six selected aphrodisiac medicinal plants. Useful parts of the selected medicinal plants were collected and extracted in methanolic solvent. The antioxidant activity of selected plant extract was determined through different antioxidant assays, namely DPPH radical scavenging assay and ferric reducing antioxidant assay. Moreover, antioxidant compounds, like total phenolics and total flavonoids contents, were also determined. Results showed that Mucuna pruriens seed extract displayed high contents of phenolic compounds with total phenolic content of 683.15±4.28 mg GAE/g dry plant material while the least phenolic content was observed in Asparagus racemosus (195.5±3.02 mg GAE/g dry plant material). Highest total flavonoids content was found in Anacyclus pyrethrum roots (156.58±4.01 μg CE/g) and the least content was found in Asparagus racemosus roots. Among the studied plant extracts, the highest radical scavenging activity was shown by Mucuna pruriens seed extract (82.05±0.55%) and the least percent scavenging activity was observed in Tribulus terrestris extract (36.40±2.01%). Vitamin C was used as positive control for antioxidant assays showing 93.54±0.9% radical scavenging activity. The plant extract also exhibited a strong reducing potential against free radicals. Therefore, the present study concluded that all the studied medicinal plants possess varying concentrations of secondary active metabolites responsible for the antioxidant properties of the tested plant extracts.
Antiproliferative effects of fresh and thermal processed green and red cultivars of curly kale (Brassica oleracea L. convar. acephala var. sabellica).

PubMed

Olsen, Helle; Grimmer, Stine; Aaby, Kjersti; Saha, Shikha; Borge, Grethe Iren A

2012-08-01

Brassica vegetables contain a diverse range of phytochemicals with biological properties such as antioxidant and anticancer activity. However, knowledge about how biological activities are affected by processing is lacking. A green cultivar and a red cultivar of curly kale were evaluated for water/methanol-soluble phytochemicals before and after processing involving blanching, freeze storage, and boil-in-bag heat treatment. In both kale cultivars, processing resulted in a significant decrease of total phenolics, antioxidant capacity, and content and distribution of flavonols, anthocyanins, hydroxycinnamic acids, glucosinolates, and vitamin C. Interestingly, the red curly kale cultivar had a higher capacity to withstand thermal loss of phytochemicals. The extracts of both green and red curly kale inhibited the cell proliferation of three human colon cancer cell lines (Caco-2, HT-29, and HCT 116). However, extracts from fresh plant material had a significantly stronger antiproliferative effect than extracts from processed plant material.
Antioxidant films based on cross-linked methyl cellulose and native Chilean berry for food packaging applications.

PubMed

López de Dicastillo, Carol; Rodríguez, Francisco; Guarda, Abel; Galotto, Maria José

2016-01-20

Development of antioxidant and antimicrobial active food packaging materials based on biodegradable polymer and natural plant extracts has numerous advantages as reduction of synthetic additives into the food, reduction of plastic waste, and food protection against microorganisms and oxidation reactions. In this way, active films based on methylcellulose (MC) and maqui (Aristotelia chilensis) berry fruit extract, as a source of antioxidants agents, were studied. On the other hand, due to the high water affinity of MC, this polymer was firstly cross-linked with glutaraldehyde (GA) at different concentrations. The results showed that the addition of GA decreased water solubility, swelling, water vapor permeability of MC films, and the release of antioxidant substances from the active materials increased with the concentration of GA. Natural extract and active cross-linked films were characterized in order to obtain the optimal formulation with the highest antioxidant activity and the best physical properties for latter active food packaging application. Copyright © 2015 Elsevier Ltd. All rights reserved.
Optical properties of humic substances and CDOM: relation to structure.

PubMed

Boyle, Erin S; Guerriero, Nicolas; Thiallet, Anthony; Del Vecchio, Rossana; Blough, Neil V

2009-04-01

The spectral dependencies of absorption and fluorescence emission (emission maxima (lamdamax), quantum yields (phi), and mean lifetimes (taum)) were acquired for a commercial lignin, Suwannee River humic (SRHA) and fulvic (SRFA) acids, and a series solid phase extracts (C18) from the Middle Atlantic Bight (MAB extracts). These parameters were compared with the relative average size and total lignin phenol content (TLP). TLP was strongly correlated with absorption at 280 and 355 nm for the MAB extracts, SRHA, and SRFA. The spectral dependence of lamdamax, phi), and taum was very similar for all samples, suggesting a common photophysical and thus structural basis. A strong decrease of phi and taum with increasing average size indicates that intramolecular interactions must be important. When combined with previous work, the results lead us to conclude that the optical properties commonly associated with terrestrial humic substances and chromophoric dissolved organic matter arise primarily from an ensemble of partially oxidized lignins derived from vascular plant sources. Theyfurther provide additional support for an electronic interaction model in which intramolecular energy transfer, excited-state electron transfer, as well as charge transfer likely play important roles in producing the observed optical and photochemical properties of these materials.
Application of manufactured products

NASA Technical Reports Server (NTRS)

Sastri, Sankar; Duke, Michael B.

1992-01-01

A wide range of products can be manufactured from the following materials: (1) lunar regolith or basalt; (2) regolith or rock beneficiated to concentrate plagioclase or other minerals; (3) iron, extracted from lunar soil or rocks by various means; (4) naturally occurring or easily obtained materials that have cementitious properties; and (5) byproducts of the above materials. Among the products that can be produced from these materials are the following: beams; plates and sheets; transparent plates (windows); bricks and blocks; pipes and tubes; low-density materials (foams); fiber, wire, and cables; foils and reflective coatings; hermetic seals (coatings); and formed objects. In addition to oxygen, which can be obtained by several processes, either from unbeneficiated regolith or by reduction of concentrated ilmenite, these materials make the simplest requirements of the lunar resource extraction system. A thorough analysis of the impact of these simplest products on the economics of space operations is not possible at this point. Research is necessary both to define optimum techniques and adapt them to space and to determine the probable market for the products so that the priority of various processes can be assessed. Discussions of the following products are presented: aerobraking heat shields; pressurized habitats; lunar photovoltaic farms; and agricultural systems.
Evaluation of Anthelmintic Activity and Composition of Pumpkin (Cucurbita pepo L.) Seed Extracts-In Vitro and in Vivo Studies.

PubMed

Grzybek, Maciej; Kukula-Koch, Wirginia; Strachecka, Aneta; Jaworska, Aleksandra; Phiri, Andrew M; Paleolog, Jerzy; Tomczuk, Krzysztof

2016-09-01

A significant number of studies report growing resistance in nematodes thriving in both humans and livestock. This study was conducted to evaluate the in vitro and in vivo anthelmintic efficiency of Curcubita pepo (C. pepo) L. hot water extract (HWE), cold water extract (CWE) or ethanol extract (ETE) on two model nematodes: Caenorhabditis elegans (C. elegans) and Heligmosoides bakeri (H. bakeri). Raman, IR and LC-MS spectroscopy analyses were performed on the studied plant material to deliver qualitative and quantitative data on the composition of the obtained extracts: ETE, HWE and CWE. The in vitro activity evaluation showed an impact of C. pepo extracts on C. elegans and different developmental stages of H. bakeri. The following in vivo experiments on mice infected with H. bakeri confirmed inhibitory properties of the most active pumpkin extract selected by the in vitro study. All of the extracts were found to contain cucurbitine, aminoacids, fatty acids, and-for the first time-berberine and palmatine were identified. All C. pepo seed extracts exhibited a nematidicidal potential in vitro, affecting the survival of L1 and L2 H. bakeri larvae. The ETE was the strongest and demonstrated a positive effect on H. bakeri eggs hatching and marked inhibitory properties against worm motility, compared to a PBS control. No significant effects of pumpkin seed extracts on C. elegans integrity or motility were found. The EtOH extract in the in vivo studies showed anthelmintic properties against both H. bakeri fecal egg counts and adult worm burdens. The highest egg counts reduction was observed for the 8 g/kg dose (IC50 against H. bakeri = 2.43; 95% Cl = 2.01-2.94). A decrease in faecal egg counts (FEC) was accompanied by a significant reduction in worm burden of the treated mice compared to the control group. Pumpkin seed extracts may be used to control of Gastrointestinal (G.I.) nematode infections. This relatively inexpensive alternative to the currently available chemotherapeutic should be considered as a novel drug candidate in the nearest future.
Clinical and laboratory evaluation of microstructural changes in the physical, mechanical and chemical properties of dental filling materials under the influence of an electromagnetic field.

PubMed

Moiseeva, Natalia S; Kunin, Anatoly A

2018-03-01

Restorative filling materials used for dental caries prevention and treatment consist of various components including monomers or oligomers, which play a significant role in forming the main structure of these materials, as well as in characterising their physical, mechanical and chemical properties. The necessity for the development and improvement of structural characteristics of polymeric dental filling materials intended for caries prevention and their life duration increase served as the initiating factor of our research. According to the research purpose and challenges, we studied the changes in the physical, mechanical and chemical properties of composite filling materials with and without electromagnetic field influence. The investigations in vivo include the study of microstructural features of polymeric filling materials by scanning electron microscopy (SEM) and the investigations in vitro include the study of sealed and extracted human teeth chips by using X-ray spectral analysis. We also evaluated the changes in the strength characteristics of dental filling materials with and without electromagnetic field influence. The analysis of the obtained data indicates the presence of structural changes in polymeric dental filling materials, including the material microstructure condensation confirmed by the SEM results, an increase in the strength and adhesion characteristics and certain regularities of the chemical elemental composition concentration change in the area of hard tooth tissue and dental filling material. These scientific data will provide tooth caries prevention and promote the increase of treatment quality.
An Alginate/Cyclodextrin Spray Drying Matrix to Improve Shelf Life and Antioxidant Efficiency of a Blood Orange By-Product Extract Rich in Polyphenols: MMPs Inhibition and Antiglycation Activity in Dysmetabolic Diseases.

PubMed

Lauro, Maria Rosaria; Crascì, Lucia; Giannone, Virgilio; Ballistreri, Gabriele; Fabroni, Simona; Sansone, Francesca; Rapisarda, Paolo; Panico, Anna Maria; Puglisi, Giovanni

2017-01-01

Alginate and β -cyclodextrin were used to produce easily dosable and spray-dried microsystems of a dried blood orange extract with antidysmetabolic properties, obtained from a by-product fluid extract. The spray-dried applied conditions were able to obtain a concentrate dried extract without the loss of AOA and with TPC and TMA values of 35-40% higher than that of the starting material. They were also effective in producing microparticles with 80-100% of encapsulation efficiency. The 2% sodium alginate was capable of improving the extract shelf life , while the beta-cyclodextrin (1 : 1 molar ratio with dried extract) prolonged the extract antioxidant efficiency by 6 hours. The good inhibition effect of the dried extract on the AGE formation and the MMP-2 and MMP-9 activity is presumably due to a synergic effect exerted by both anthocyanin and bioflavonoid extract compounds and was improved by the use of alginate and cyclodextrin.
An Alginate/Cyclodextrin Spray Drying Matrix to Improve Shelf Life and Antioxidant Efficiency of a Blood Orange By-Product Extract Rich in Polyphenols: MMPs Inhibition and Antiglycation Activity in Dysmetabolic Diseases

PubMed Central

Giannone, Virgilio; Ballistreri, Gabriele; Fabroni, Simona; Rapisarda, Paolo; Panico, Anna Maria; Puglisi, Giovanni

2017-01-01

Alginate and β-cyclodextrin were used to produce easily dosable and spray-dried microsystems of a dried blood orange extract with antidysmetabolic properties, obtained from a by-product fluid extract. The spray-dried applied conditions were able to obtain a concentrate dried extract without the loss of AOA and with TPC and TMA values of 35–40% higher than that of the starting material. They were also effective in producing microparticles with 80–100% of encapsulation efficiency. The 2% sodium alginate was capable of improving the extract shelf life, while the beta-cyclodextrin (1 : 1 molar ratio with dried extract) prolonged the extract antioxidant efficiency by 6 hours. The good inhibition effect of the dried extract on the AGE formation and the MMP-2 and MMP-9 activity is presumably due to a synergic effect exerted by both anthocyanin and bioflavonoid extract compounds and was improved by the use of alginate and cyclodextrin. PMID:29230268
Sample preparation for an optimized extraction of localized metabolites in lichens: Application to Pseudevernia furfuracea.

PubMed

Komaty, Sarah; Letertre, Marine; Dang, Huyen Duong; Jungnickel, Harald; Laux, Peter; Luch, Andreas; Carrié, Daniel; Merdrignac-Conanec, Odile; Bazureau, Jean-Pierre; Gauffre, Fabienne; Tomasi, Sophie; Paquin, Ludovic

2016-04-01

Lichens are symbiotic organisms known for producing unique secondary metabolites with attractive cosmetic and pharmacological properties. In this paper, we investigated three standard methods of preparation of Pseudevernia furfuracea (blender grinding, ball milling, pestle and mortar). The materials obtained were characterized by electronic microscopy, nitrogen adsorption and compared from the point of view of extraction. Their microscopic structure is related to extraction efficiency. In addition, it is shown using thalline reactions and mass spectrometry mapping (TOF-SIMS) that these metabolites are not evenly distributed throughout the organism. Particularly, atranorin (a secondary metabolite of interest) is mainly present in the cortex of P. furfuracea. Finally, using microwave assisted extraction (MAE) we obtained evidence that an appropriate preparation can increase the extraction efficiency of atranorin by a factor of five. Copyright © 2016 Elsevier B.V. All rights reserved.
Application of supercritical fluid carbon dioxide to the extraction and analysis of lipids.

PubMed

Lee, Jae Won; Fukusaki, Eiichiro; Bamba, Takeshi

2012-10-01

Supercritical carbon dioxide (SCCO(2)) is an ecofriendly supercritical fluid that is chemically inert, nontoxic, noninflammable and nonpolluting. As a green material, SCCO(2) has desirable properties such as high density, low viscosity and high diffusivity that make it suitable for use as a solvent in supercritical fluid extraction, an effective and environment-friendly analytical method, and as a mobile phase for supercritical fluid chromatography, which facilitates high-throughput, high-resolution analysis. Furthermore, the low polarity of SCCO(2) is suitable for the extraction and analysis of hydrophobic compounds. The growing concern surrounding environmental pollution has triggered the development of green analysis methods based on the use of SCCO(2) in various laboratories and industries. SCCO(2) is becoming an effective alternative to conventional organic solvents. In this review, the usefulness of SCCO(2) in supercritical fluid extraction and supercritical fluid chromatography for the extraction and analysis of lipids is described.
Near infrared spectroscopy based monitoring of extraction processes of raw material with the help of dynamic predictive modeling

NASA Astrophysics Data System (ADS)

Wang, Haixia; Suo, Tongchuan; Wu, Xiaolin; Zhang, Yue; Wang, Chunhua; Yu, Heshui; Li, Zheng

2018-03-01

The control of batch-to-batch quality variations remains a challenging task for pharmaceutical industries, e.g., traditional Chinese medicine (TCM) manufacturing. One difficult problem is to produce pharmaceutical products with consistent quality from raw material of large quality variations. In this paper, an integrated methodology combining the near infrared spectroscopy (NIRS) and dynamic predictive modeling is developed for the monitoring and control of the batch extraction process of licorice. With the spectra data in hand, the initial state of the process is firstly estimated with a state-space model to construct a process monitoring strategy for the early detection of variations induced by the initial process inputs such as raw materials. Secondly, the quality property of the end product is predicted at the mid-course during the extraction process with a partial least squares (PLS) model. The batch-end-time (BET) is then adjusted accordingly to minimize the quality variations. In conclusion, our study shows that with the help of the dynamic predictive modeling, NIRS can offer the past and future information of the process, which enables more accurate monitoring and control of process performance and product quality.
Nanomechanical investigation of ion implanted single crystals - Challenges, possibilities and pitfall traps related to nanoindentation

NASA Astrophysics Data System (ADS)

Kurpaska, Lukasz

2017-10-01

Nanoindentation technique have developed considerably over last thirty years. Nowadays, commercially available systems offer very precise measurement in nano- and microscale, environmental noise cancelling (or at least noise suppressing), in situ high temperature indentation in controlled atmosphere and vacuum conditions and different additional options, among them dedicated indentation is one of the most popular. Due to its high precision, and ability to measure mechanical properties from very small depths (tens of nm), this technique become quite popular in the nuclear society. It is known that ion implantation (to some extent) can simulate the influence of neutron flux. However, depth of the material damage is very limited resulting in creation of thin layer of modified material over unmodified bulk. Therefore, only very precise technique, offering possibility to control depth of the measurement can be used to study functional properties of the material. For this reason, nanoindentation technique seems to be a perfect tool to investigate mechanical properties of ion implanted specimens. However, conducting correct nanomechanical experiment and extracting valuable mechanical parameters is not an easy task. In this paper a discussion about the nanoindentation tests performed on ion irradiated YSZ single crystal is presented. The goal of this paper is to discuss possible traps when studying mechanical properties of such materials and thin coatings.
Single-layer MoS2 electronics.

PubMed

Lembke, Dominik; Bertolazzi, Simone; Kis, Andras

2015-01-20

CONSPECTUS: Atomic crystals of two-dimensional materials consisting of single sheets extracted from layered materials are gaining increasing attention. The most well-known material from this group is graphene, a single layer of graphite that can be extracted from the bulk material or grown on a suitable substrate. Its discovery has given rise to intense research effort culminating in the 2010 Nobel Prize in physics awarded to Andre Geim and Konstantin Novoselov. Graphene however represents only the proverbial tip of the iceberg, and increasing attention of researchers is now turning towards the veritable zoo of so-called "other 2D materials". They have properties complementary to graphene, which in its pristine form lacks a bandgap: MoS2, for example, is a semiconductor, while NbSe2 is a superconductor. They could hold the key to important practical applications and new scientific discoveries in the two-dimensional limit. This family of materials has been studied since the 1960s, but most of the research focused on their tribological applications: MoS2 is best known today as a high-performance dry lubricant for ultrahigh-vacuum applications and in car engines. The realization that single layers of MoS2 and related materials could also be used in functional electronic devices where they could offer advantages compared with silicon or graphene created a renewed interest in these materials. MoS2 is currently gaining the most attention because the material is easily available in the form of a mineral, molybdenite, but other 2D transition metal dichalcogenide (TMD) semiconductors are expected to have qualitatively similar properties. In this Account, we describe recent progress in the area of single-layer MoS2-based devices for electronic circuits. We will start with MoS2 transistors, which showed for the first time that devices based on MoS2 and related TMDs could have electrical properties on the same level as other, more established semiconducting materials. This allowed rapid progress in this area and was followed by demonstrations of basic digital circuits and transistors operating in the technologically relevant gigahertz range of frequencies, showing that the mobility of MoS2 and TMD materials is sufficiently high to allow device operation at such high frequencies. Monolayer MoS2 and other TMDs are also direct band gap semiconductors making them interesting for realizing optoelectronic devices. These range from simple phototransistors showing high sensitivity and low noise, to light emitting diodes and solar cells. All the electronic and optoelectronic properties of MoS2 and TMDs are accompanied by interesting mechanical properties with monolayer MoS2 being as stiff as steel and 30× stronger. This makes it especially interesting in the context of flexible electronics where it could combine the high degree of mechanical flexibility commonly associated with organic semiconductors with high levels of electrical performance. All these results show that MoS2 and TMDs are promising materials for electronic and optoelectronic applications.
Studies on optical and electrical properties of green synthesized TiO2@Ag core-shell nanocomposite material

NASA Astrophysics Data System (ADS)

Ganapathy, M.; Senthilkumar, N.; Vimalan, M.; Jeysekaran, R.; Vetha Potheher, I.

2018-04-01

Newly adopted green approach has been used to synthesize pure titanium dioxide (TiO2) nanoparticles (NPs) and silver deposited titanium dioxide (TiO2@Ag) core–shell nanocomposite (CSNC) from Nigella Sativa (black cumin) seed extract for the first time. The phytochemicals available in Nigella Sativa (NS) seed extract acts as reducing agent in the formation of nanoparticles as well as nanocomposite. The morphology, crystal structure, particle size and phase composition of green synthesized TiO2 NPs and TiO2@Ag CSNC are investigated by High Resolution Transmission Electron Microscopy (HRTEM), Field Emission Scanning Electron Microscopy (FESEM), Powder x-ray diffraction (PXRD), FT–Raman and Fourier Transform Infrared spectroscopy (FT-IR). The red shift in (from 333 nm to 342 nm) UV–Vis spectrum confirmed the deposition of Ag on TiO2. The reduced intensity peaks of Photoluminescence spectra (PL) also indicate the deposition of Ag on TiO2. Further the electrical properties of pure TiO2 and TiO2@Ag CSNC have studied by dielectric studies and ac conductivity measurements. The dielectric constant and the dielectric loss of TiO2@Ag CSNC are better than pure TiO2. From these improved results, the green synthesized TiO2@Ag CSNC from NS seed extract is may be a suitable material for device fabrication in the visible region.
In vitro fabrication of dental filling nanopowder by green route and its antibacterial activity against dental pathogens.

PubMed

Lee, Jeong-Ho; Velmurugan, Palanivel; Park, Jung-Hee; Lee, Kui-Jae; Jin, Jong-Sik; Park, Yool-Jin; Bang, Keuk-Soo; Oh, Byung-Taek

2016-06-01

The aim of this study was to introduce novel Sn, Cu, Hg, and Ag nanopowders (NPs) and a composite nanopowder (NP) synthesized using Salvia miltiorrhiza Bunge (SM) root extract as a reducing and capping agent to improve the antibacterial property of dental filling materials. All of the NPs obtained were characterized using a scanning transmission electron microscope (STEM), and energy dispersive X-ray (EDX) spectrum imaging was performed to map the elemental distributions of the NP composite. Fourier transform infrared (FTIR) spectroscopy was performed to identify the role of various functional groups in all of the obtained NPs and the phyto-compound responsible for the reduction of various metal ions. The X-ray diffraction (XRD) patterns clearly illustrated the crystalline phase of the synthesized NP. The antibacterial properties of the synthesized Sn, Cu, Hg, Ag, composite NP, SM root extract, and commercial amalgam powder were evaluated. The Cu, composite NP, SM root extract and Ag NP displayed excellent antibacterial activity against dental bacteria Streptococcus mutans and Lactobacillus acidophilus. The results of this study require further evaluation for signs of metal toxicity in appropriate animal models. However, the results are encouraging for the application of metal NPs as suitable alternatives for antibiotics and disinfectants, especially in dental filling materials. Copyright © 2016 Elsevier B.V. All rights reserved.
Evaluation and Comparison of the Antibacterial Activity against Streptococcus mutans of Grape Seed Extract at Different Concentrations with Chlorhexidine Gluconate: An in vitro Study

PubMed Central

Dave, Bhavna; Vyas, Soham M; Shah, Nupur

2016-01-01

Introduction Streptococcus mutans has been implicated as primary microorganisms which cause dental caries in humans. There has been an increased interest in the therapeutic properties of some medicinal plants and natural compounds which have demonstrated antibacterial activities. Grape is one of the plants of this group which contains tannin and polyphenolic compound. Aim To evaluate and compare antibacterial activity of grape seed extract at different concentrations with chlorhexidine gluconate against S. mutans. Materials and methods Grape seeds were extracted with ethanol/water ratio of 70:30 volume/volume. The extracts were filtered through Whatman No. 1 filter paper until it becomes colorless. Streptococcus mutans strains were taken. To check the antimicrobial properties of grape seed extract at different concentration and chlorhexidine gluconate, they were added to S. mutans strain and incubated for 48 hours than colony-forming units/mL were checked. Results Grape seed extract at higher concentration were found to be more potent against S. mutans. Chlorhexidine gluconate was found to have most potent antibacterial action compared to all different concentrations of grape seed extract. Conclusion Grape seed extract as a natural antimicrobial compound has inhibitory effect against S. mutans. How to cite this article Swadas M, Dave B, Vyas SM, Shah N. Evaluation and Comparison of the Antibacterial Activity against Streptococcus mutans of Grape Seed Extract at Different Concentrations with Chlorhexidine Gluconate: An in vitro Study. Int J Clin Pediatr Dent 2016;9(3):181-185. PMID:27843246
Fe-C interactions and soil organic matter stability in two tropical soils of contrasting parent materials

NASA Astrophysics Data System (ADS)

Coward, E.; Thompson, A.; Plante, A. F.

2014-12-01

The long residence time of soil organic matter (SOM) is a dynamic property, reflecting the diversity of stabilization mechanisms active within the soil matrix. Climate and ecosystem properties act at the broadest scale, while biochemical recalcitrance, physical occlusion and mineral association drive stability at the microscale. Increasing evidence suggests that the stability of SOM is dominated by organo-mineral interactions. However, the 2:1 clays that provide much of the stabilization capacity in temperate soils are typically absent in tropical soils due to weathering. In contrast, these soils may contain an abundance of iron and aluminium oxides and oxyhydroxides, known as short-range-order (SRO) minerals. These SRO minerals are capable of SOM stabilization through adsorption or co-precipitation, a faculty largely enabled by their high specific surface area (SSA). As such, despite their relatively small mass, SRO minerals may contribute substantially to the SOM stabilization capacity of tropical soils. The objective of this work is to characterize and quantify these Fe-C interactions. Surface (0-20 cm) soil samples were taken from 20 quantitative soil pits dug within the Luquillo Critical Zone Observatory in northeast Puerto Rico. Soils were stratified across granodiorite and volcaniclastic parent materials. Four extraction procedures were used to isolate three different forms of Fe-C interactions: sodium pyrophosphate to isolate organo-metallic complexes, hydroxylamine and oxalate to isolate SRO Fe- and Al-hydroxides, and dithionite to isolate crystalline Fe-oxyhydroxides. Extracts were analysed for DOC and Fe and Al concentrations to estimate the amount of SOM associated with each mineral type. Soils were subjected to SSA and solid-phase C analyses before and after extraction to determine the contribution of the various Fe mineral types to soil SSA, and therefore to potential stabilization capacity through organo-mineral complexation. Preliminary results suggest that extracts from granodiorite parent material contain on average twice the Fe than those from volcaniclastic parent material. The removal of SRO minerals reduced SSA in both soil types, and appear to contribute substantially to SOM stabilization compared to the bulk mineral matrix.
Effects of Fuel Components and Combustion Particle Physicochemical Properties on Toxicological Responses of Lung Cells

PubMed Central

Jaramillo, Isabel C.; Sturrock, Anne; Ghiassi, Hossein; Woller, Diana J.; Deering-Rice, Cassandra E.; Lighty, JoAnn S.; Paine, Robert; Reilly, Christopher; Kelly, Kerry E.

2017-01-01

The physicochemical properties of combustion particles that promote lung toxicity are not fully understood, hindered by the fact that combustion particles vary based on the fuel and combustion conditions. Real-world combustion-particle properties also continually change as new fuels are implemented, engines age, and engine technologies evolve. This work used laboratory-generated particles produced under controlled combustion conditions in an effort to understand the relationship between different particle properties and the activation of established toxicological outcomes in human lung cells (H441 and THP-1). Particles were generated from controlled combustion of two simple biofuel/diesel surrogates (methyl decanoate and dodecane/BD, and butanol and dodecane/AD) and compared to a widely studied reference diesel particle (NIST SRM2975/RD). BD, AD, and RD particles exhibited differences in size, surface area, extractable chemical mass, and the content of individual polycyclic aromatic hydrocarbons (PAHs). Some of these differences were directly associated with different effects on biological responses. BD particles had the greatest surface area, amount of extractable material and oxidizing potential. These particles and extracts induced cytochrome P450 1A1 and 1B1 enzyme mRNA in lung cells. AD particles and extracts had the greatest total PAH content and also caused CYP1A1 and 1B1 mRNA induction. The RD extract contained the highest relative concentration of 2-ring PAHs and stimulated the greatest level of interleukin-8 (IL-8) and tumor necrosis factor-alpha (TNFα) cytokine secretion. Finally, AD and RD were more potent activators of TRPA1 than BD, and while neither the TRPA1 antagonist HC-030031 nor the antioxidant N-acetylcysteine (NAC) affected CYP1A1 or 1B1 mRNA induction, both inhibitors reduced IL-8 secretion and mRNA induction. These results highlight that differences in fuel and combustion conditions affect the physicochemical properties of particles, and these differences, in turn, affect commonly studied biological/toxicological responses. PMID:29227181
THE BIOLOGICAL ACTIVITIES OF MOLTKIA AUREA BOISS., AN ENDEMIC SPECIES TO TURKEY

PubMed Central

Balpinar, Neslihan; Okmen, Gulten

2017-01-01

Background: Staphylococcus aureus is the direct reason of mastitis. Mastitis is a disease characterized by pathological changes in mammary glands as well as physical, chemical, bacteriological changes in milk. This disease causes loses in milk yield and quality. In recent years, it is reported that mastitis pathogens have developed a resistance to antibiotics as a natural consequence of widespread use of it. Today’s researches are focused on discovering and using new antibiotics against bacteria. The aim of this paper is to examine the antibacterial properties of Moltkia aurea Boiss.][o] (an endemic species to Turkey), and its other biological activities. Materials and Methods: All of the extracts were tested by disc diffusion assay in order to screen antibacterial activity. MIC values were evaluated as antibacterial activities of plant extracts. The non-enzymatic antioxidative activities including DPPH radical scavenging effects were studied in vitro. Results and Conclusions: Results shown that the extracts had strong antibacterial effects on three bacteria (S. aureus- 17, S. aureus-18 and CNS-37) and the range of inhibition zone was 4-6mm. This three bacteria screened the lowest sensitivity to 65000 μg /mL concentration. Besides, the extracts were tested for non-enzymatic antioxidant activities. As a result, the methanol extract of the flower displayed a strong antioxidant activity. The various extracts of Moltkia aurea have different antibacterial and antioxidant properties. PMID:28573222

Methodologies in determining mechanical properties of thin films using nanoindentation

NASA Astrophysics Data System (ADS)

Han, Seung Min Jane

Thin films are critical components of microelectronic and MEMS devices, and evaluating their mechanical properties is of current interest. As the dimensions of the devices become smaller and smaller, however, understanding the mechanical properties of materials at sub-micron length scales becomes more challenging. The conventional methods for evaluating strengths of materials in bulk form cannot be applied, and new methodologies are required for accurately evaluating mechanical properties of thin films. In this work, development of methodologies using the nanoindenter was pursued in three parts: (1) creation of a new method for extracting thin film hardness, (2) use of combinatorial methods for determining compositions with desired mechanical properties, and (3) use of microcompression testing of sub-micron sized pillars to understand plasticity in Al-Sc multilayers. The existing nanoindentation hardness model by Oliver & Pharr is unable to accurately determine the hardness of thin films on substrates with an elastic mismatch. Thus, a new method of analysis for extracting thin film hardness from film/substrate systems, that eliminates the effect of elastic mismatch of the underlying substrate, surface roughness, and also pile-up/sink-in, is needed. Such a method was developed in the first part of this study. The feasibility of using the nanoindentation hardness together with combinatorial methods to efficiently scan through mechanical properties of Ti-Al metallic alloys was examined in the second part of this study. The combinatorial approach provides an efficient method that can be used to determine alloy compositions that might merit further exploration and development as bulk materials. Finally, the mechanical properties of Al-Al3Sc multilayers with bilayer periods ranging from 6-100 nm were examined using microcompression. The sub-micron sized pillars were prepared using the focused ion beam (FIB) and compression tested with the flat tip of the nanoindenter. The measured yield strengths show the trend of increasing strength with decreasing bilayer period, and agree with the nanoindentation hardness results using the suitable Tabor correction factor. Strain softening was observed at large strains, and a new model for the true stress and true strain was developed to account for the inhomogeneous deformation geometry.
Thermal and Mechanical Properties of Natural Rubber Composites Reinforced with Cellulose Nanocrystals from Southern Pine

Treesearch

Chunmei Zhang; Yi Dan; Jun Peng; Lih-Sheng Turng; Ronald Sabo; Craig Clemons

2014-01-01

There is currently a considerable interest in developing bio-based and green nanocomposites in industrial and technological areas owing to their biodegradability, biocompatibility, and environmental friendliness. In this study, a bio-based nanosized material, cellulose nanocrystals (CNC), extracted from southern pine pulp was employed as a reinforcing agent in a...
The reaction of boric acid with wood in a polystyrene matrix

Treesearch

Yanxin Wang; John Simonsen; Carlos Pascoal Neto; Joao Rocha; Timothy G. Rials; Eric Hart

1996-01-01

The reaction of boric acid with wood fibers in a polymer melt was examined using 13C-nuclear magnetic resonance (NMR), 11B-NMR. differential scanning calorimetry, dynamic mechanical analysis, and component extraction and by the determination of material properties. Samples were blended at 350 and 380Â°F in a roll mill. The...
Functional properties and dietary fiber characterization of mango processing by-products (Mangifera indica L., cv Ataulfo and Tommy Atkins).

PubMed

García-Magaña, María de Lourdes; García, Hugo S; Bello-Pérez, Luis A; Sáyago-Ayerdi, Sonia G; de Oca, Miguel Mata-Montes

2013-09-01

Several reports have focused on utilization of post-harvest residues of crops, while neglecting those residues produced by mango processing. These residues represent a waste of nutrients and a source of environmental contaminants. Such by-products could be valuable sources of dietary fiber (DF), antioxidant compounds, and single carbohydrates. The aim of this study was to evaluate some functional properties (FP), and the content of DF and polyphenols (PP) of the peel and coarse material obtained from residues during the industrial processing of Ataulfo and Tommy Atkins mangoes. The total dietary fiber (TDF) content was about 225 mg/g and 387 mg/g (dry weight) for the coarse material and the peel, respectively, from which soluble dietary fiber represented 23 and 42%, respectively. The main neutral sugar identified was rhamnose, especially in peels; the klason lignin (KL) content was 92 mg/g, which highlights the Ataulfo peel (Ataulfo-P) and the Tommy Atkins peel (Tommy Atkins-P). The extractable PP content in Ataulfo-P was higher than in Tommy-Atkins-P, and interesting data for non-extractable PP were obtained in the residues. FP as swelling, water holding, oil holding, and glucose absorption in the residues was studied, obtaining better functional properties when compared to cellulose fiber. The results show that mango industrial by-products, mainly from the Ataulfo-P variety, could be used as ingredients in food products because of their functional properties as well as their DF and PP content.
Computer-aided screening system for cervical precancerous cells based on field emission scanning electron microscopy and energy dispersive x-ray images and spectra

NASA Astrophysics Data System (ADS)

Jusman, Yessi; Ng, Siew-Cheok; Hasikin, Khairunnisa; Kurnia, Rahmadi; Osman, Noor Azuan Bin Abu; Teoh, Kean Hooi

2016-10-01

The capability of field emission scanning electron microscopy and energy dispersive x-ray spectroscopy (FE-SEM/EDX) to scan material structures at the microlevel and characterize the material with its elemental properties has inspired this research, which has developed an FE-SEM/EDX-based cervical cancer screening system. The developed computer-aided screening system consisted of two parts, which were the automatic features of extraction and classification. For the automatic features extraction algorithm, the image and spectra of cervical cells features extraction algorithm for extracting the discriminant features of FE-SEM/EDX data was introduced. The system automatically extracted two types of features based on FE-SEM/EDX images and FE-SEM/EDX spectra. Textural features were extracted from the FE-SEM/EDX image using a gray level co-occurrence matrix technique, while the FE-SEM/EDX spectra features were calculated based on peak heights and corrected area under the peaks using an algorithm. A discriminant analysis technique was employed to predict the cervical precancerous stage into three classes: normal, low-grade intraepithelial squamous lesion (LSIL), and high-grade intraepithelial squamous lesion (HSIL). The capability of the developed screening system was tested using 700 FE-SEM/EDX spectra (300 normal, 200 LSIL, and 200 HSIL cases). The accuracy, sensitivity, and specificity performances were 98.2%, 99.0%, and 98.0%, respectively.
Effect of acid- and alkaline-aided extractions on functional and rheological properties of proteins recovered from mechanically separated turkey meat (MSTM).

PubMed

Hrynets, Yuliya; Omana, Dileep A; Xu, Yan; Betti, Mirko

2010-09-01

Functional and rheological characteristics of acid- and alkali-extracted proteins from mechanically separated turkey meat (MSTM) have been investigated. Extractions were carried out at 4 pH values (2.5, 3.5, 10.5, and 11.5). The study demonstrated that alkali and acid extractions resulted in significant (P < 0.0001) decreases of cooking and water loss compared to raw MSTM; however, the cooking loss was found to be similar (P = 0.5699) among the different protein isolates. Proteins extracted at pH 10.5 showed the lowest (P = 0.0249) water loss. Emulsion and foaming properties were found to be slightly higher in alkali-extracted proteins compared to those for acid extractions. The myofibrillar protein fraction showed better ability to form and stabilize emulsions compared to sarcoplasmic proteins. Myofibrillar proteins also showed better foam expansion; however, foam volume stability was similar for both myofibrillar and sarcoplasmic protein fractions. Textural characteristics (hardness, chewiness, springiness, and cohesiveness) of recovered proteins were found to be unaffected (P > 0.05) by different extraction pH. The protein extracted at pH 3.5 formed a highly viscoelastic gel network as evidenced by storage modulus (G') values, whereas the gel formed from proteins extracted at pH 10.5 was found to be the weakest. The work also revealed that acid treatments were more effective for removal of total heme pigments from MSTM. Color characteristics of protein isolates were markedly improved compared to the initial material and tended to be better when subjected to acid extractions. Mechanically separated meat is one of the cheapest sources of protein obtained by grinding meat and bones together and forcing the mixture through a perforated drum. The use of mechanically separated turkey meat (MSTM) for the production of further processed poultry products is limited due to its undesirable color and textural properties. Recovery of proteins from MSTM using pH shifting process will help the poultry processors to get better returns and also create opportunity to produce functional food ingredients.
In vitro erythrocyte membrane stabilization properties of Carica papaya L. leaf extracts

PubMed Central

Ranasinghe, Priyanga; Ranasinghe, Pathmasiri; Abeysekera, W. P. Kaushalya M.; Premakumara, G. A. Sirimal; Perera, Yashasvi S.; Gurugama, Padmalal; Gunatilake, Saman B.

2012-01-01

Background: Carica papaya L. fruit juice and leaf extracts are known to have many beneficial medical properties. Recent reports have claimed possible beneficial effects of C. papaya L. leaf juice in treating patients with dengue viral infections. This study aims to evaluate the membrane stabilization potential of C. papaya L. leaf extracts using an in vitro hemolytic assay. Materials and Methods: The study was conducted in between June and August 2010. Two milliliters of blood from healthy volunteers and patients with serologically confirmed current dengue infection were freshly collected and used in the assays. Fresh papaya leaves at three different maturity stages (immature, partly matured, and matured) were cleaned with distilled water, crushed, and the juice was extracted with 10 ml of cold distilled water. Freshly prepared cold water extracts of papaya leaves (1 ml containing 30 μl of papaya leaf extracts, 20 μl from 40% erythrocytes suspension, and 950 μl of phosphate buffered saline) were used in the heat-induced and hypotonic-induced hemolytic assays. In dose response experiments, six different concentrations (9.375, 18.75, 37.5, 75, 150, and 300 μg/ml) of freeze dried extracts of the partly matured leaves were used. Membrane stabilization properties were investigated with heat-induced and hypotonicity-induced hemolysis assays. Results: Extracts of papaya leaves of all three maturity levels showed a significant reduction in heat-induced hemolysis compared to controls (P < 0.05). Papaya leaf extracts of all three maturity levels showed more than 25% inhibition at a concentration of 37.5 μg/ml. The highest inhibition of heat-induced hemolysis was observed at 37.5 μg/ml. Inhibition activity of different maturity levels was not significantly (P < 0.05) different from one another. Heat-induced hemolysis inhibition activity did not demonstrate a linear dose response relationship. At 37.5 μg/ml concentration of the extract, a marked inhibition of hypotonicity-induced hemolysis was observed. Conclusion: C. papaya L. leaf extracts showed a significant inhibition of hemolysis in vitro and could have a potential therapeutic effect on disease processes causing destabilization of biological membranes. PMID:23225962
Evaluation of Anthelmintic Activity and Composition of Pumpkin (Cucurbita pepo L.) Seed Extracts—In Vitro and in Vivo Studies

PubMed Central

Grzybek, Maciej; Kukula-Koch, Wirginia; Strachecka, Aneta; Jaworska, Aleksandra; Phiri, Andrew M.; Paleolog, Jerzy; Tomczuk, Krzysztof

2016-01-01

A significant number of studies report growing resistance in nematodes thriving in both humans and livestock. This study was conducted to evaluate the in vitro and in vivo anthelmintic efficiency of Curcubita pepo (C. pepo) L. hot water extract (HWE), cold water extract (CWE) or ethanol extract (ETE) on two model nematodes: Caenorhabditis elegans (C. elegans) and Heligmosoides bakeri (H. bakeri). Methods: Raman, IR and LC-MS spectroscopy analyses were performed on the studied plant material to deliver qualitative and quantitative data on the composition of the obtained extracts: ETE, HWE and CWE. The in vitro activity evaluation showed an impact of C. pepo extracts on C. elegans and different developmental stages of H. bakeri. The following in vivo experiments on mice infected with H. bakeri confirmed inhibitory properties of the most active pumpkin extract selected by the in vitro study. All of the extracts were found to contain cucurbitine, aminoacids, fatty acids, and-for the first time-berberine and palmatine were identified. All C. pepo seed extracts exhibited a nematidicidal potential in vitro, affecting the survival of L1 and L2 H. bakeri larvae. The ETE was the strongest and demonstrated a positive effect on H. bakeri eggs hatching and marked inhibitory properties against worm motility, compared to a PBS control. No significant effects of pumpkin seed extracts on C. elegans integrity or motility were found. The EtOH extract in the in vivo studies showed anthelmintic properties against both H. bakeri fecal egg counts and adult worm burdens. The highest egg counts reduction was observed for the 8 g/kg dose (IC50 against H. bakeri = 2.43; 95% Cl = 2.01–2.94). A decrease in faecal egg counts (FEC) was accompanied by a significant reduction in worm burden of the treated mice compared to the control group. Conclusions: Pumpkin seed extracts may be used to control of Gastrointestinal (G.I.) nematode infections. This relatively inexpensive alternative to the currently available chemotherapeutic should be considered as a novel drug candidate in the nearest future. PMID:27598135
Creating a Holistic Extractables and Leachables (E&L) Program for Biotechnology Products.

PubMed

Li, Kim; Rogers, Gary; Nashed-Samuel, Yasser; Lee, Hans; Mire-Sluis, Anthony; Cherney, Barry; Forster, Ronald; Yeh, Ping; Markovic, Ingrid

2015-01-01

The risk mitigation of extractables and leachables presents significant challenges to regulators and drug manufacturers with respect to the development, as well as the lifecycle management, of drug products. A holistic program is proposed, using a science- and risk-based strategy for testing extractables and leachables from primary containers, drug delivery devices, and single-use systems for the manufacture of biotechnology products. The strategy adopts the principles and concepts from ICH Q9 and ICH Q8(R2). The strategy is phase-appropriate, progressing from extractables testing for material screening/selection/qualification through leachables testing of final products. The strategy is designed primarily to ensure patient safety and product quality of biotechnology products. The holistic program requires robust extraction studies using model solvents, with careful consideration of solvation effect, pH, ionic strength, temperature, and product-contact surface and duration. From a wide variety of process- and product-contact materials, such extraction studies have identified and quantified over 200 organic extractable compounds. The most commonly observed compounds were siloxanes, fatty acid amides, and methacrylates. Toxicology assessments were conducted on these compounds using risk-based decision analysis. Parenteral permitted daily exposure limits were derived, as appropriate, for the majority of these compounds. Analysis of the derived parenteral permitted daily exposure limits helped to establish action thresholds to target high-risk leachables in drug products on stability until expiry. Action thresholds serve to trigger quality investigations to determine potential product impact. The holistic program also evaluates the potential risk for immunogenicity. This approach for primary drug containers and delivery devices is also applicable to single-use systems when justified with a historical knowledge base and understanding of the manufacturing processes of biotechnology products. In the development of a drug product, careful consideration is given to impurities that may originate from manufacturing equipment, process components, and packaging materials. The majority of such impurities are common chemical additives used to improve the physicochemical properties of a wide range of plastic materials. Suppliers and drug manufacturers conduct studies to extract chemical additives from the plastic materials in order to screen and predict those that may leach into a drug product. In this context, the term extractables refers to a profile of extracted compounds observed in studies under harsh conditions. In contrast, the term leachables refers to those impurities that leach from the materials under real-use conditions and may be present in final drug products. The purpose of this article is to present a holistic approach that effectively minimizes the risk of leachables to patient safety and product quality. © PDA, Inc. 2015.
Photovoltaic Performance of Inverted Polymer Solar Cells Using Hybrid Carbon Quantum Dots and Absorption Polymer Materials

NASA Astrophysics Data System (ADS)

Lim, Hwain; Lee, Kyu Seung; Liu, Yang; Kim, Hak Yong; Son, Dong Ick

2018-05-01

We report the synthesis and characterization of the carbon quantum dots (C-dots) easily obtained from citric acid and ethanediamine, and also investigated structural, optical and electrical properties. The C-dots have extraordinary optical and electrical features such as absorption of ultraviolet range and effective interface for charge separation and transport in active layer, which make them attractive materials for applications in photovoltaic devices (PV). The C-dots play important roles in charge extraction in the PV structures, they can be synthesized by a simple method and used to insert in active layer of polymer solar cells. In this study, we demonstrate that improve charge transport properties of inverted polymer solar cells (iPSCs) with C-dots and structural, optical and electrical properties of C-dots. As a result, iPSCs with C-dots showed enhancement of more than 30% compared with that of the contrast device in power conversion efficiency.
Coal conversion systems design and process modeling. Volume 1: Application of MPPR and Aspen computer models

NASA Technical Reports Server (NTRS)

1981-01-01

The development of a coal gasification system design and mass and energy balance simulation program for the TVA and other similar facilities is described. The materials-process-product model (MPPM) and the advanced system for process engineering (ASPEN) computer program were selected from available steady state and dynamic models. The MPPM was selected to serve as the basis for development of system level design model structure because it provided the capability for process block material and energy balance and high-level systems sizing and costing. The ASPEN simulation serves as the basis for assessing detailed component models for the system design modeling program. The ASPEN components were analyzed to identify particular process blocks and data packages (physical properties) which could be extracted and used in the system design modeling program. While ASPEN physical properties calculation routines are capable of generating physical properties required for process simulation, not all required physical property data are available, and must be user-entered.
3D composites based on the blends of chitosan and collagen with the addition of hyaluronic acid.

PubMed

Sionkowska, Alina; Kaczmarek, Beata; Lewandowska, Katarzyna; Grabska, Sylwia; Pokrywczyńska, Marta; Kloskowski, Tomasz; Drewa, Tomasz

2016-08-01

3D porous composites based on blends of chitosan, collagen and hyaluronic acid were obtained through the lyophilization process. Mechanical properties, swelling behavior and thermal stability of the blends were studied. Moreover, SEM images were taken and the structure of the blends was studied. Biological properties of the materials obtained were investigated by analyzing of proliferation rate of fibroblast cells incubated with biomaterial extract using MTT assay (3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide). The results showed that the properties of 3D composites based on the blends of chitosan and collagen were altered after the addition 1%, 2% and 5% of hyaluronic acid. Mechanical properties and thermal stability of chitosan/collagen blends were improved in the presence of hyaluronic acid in the composite. New 3D materials based on the blends of chitosan, collagen and hyaluronic acid were non-toxic and did not significantly affect cell morphology. Copyright © 2016 Elsevier B.V. All rights reserved.
Extrusion of xylans extracted from corn cobs into biodegradable polymeric materials.

PubMed

Bahcegul, Erinc; Akinalan, Busra; Toraman, Hilal E; Erdemir, Duygu; Ozkan, Necati; Bakir, Ufuk

2013-12-01

Solvent casting technique, which comprises multiple energy demanding steps including the dissolution of a polymer in a solvent followed by the evaporation of the solvent from the polymer solution, is currently the main technique for the production of xylan based polymeric materials. The present study shows that sufficient water content renders arabinoglucuronoxylan (AGX) polymers extrudable, enabling the production of AGX based polymeric materials in a single step via extrusion, which is economically advantageous to solvent casting process for mass production. AGX polymers with water content of 27% were found to yield extrudates at an extrusion temperature of 90°C. The extruded strips showed very good mechanical properties with an ultimate tensile strength of 76 ± 6 MPa and elongation at break value of 35 ± 8%, which were superior to the mechanical properties of the strips obtained from polylactic acid. Copyright © 2013 Elsevier Ltd. All rights reserved.
DOE Office of Scientific and Technical Information (OSTI.GOV)

Kuharik, J.; Madrak, R.; Makarov, A.

A second harmonic tunable RF cavity is being devel-oped for the Fermilab Booster. This device, which prom-ises reduction of the particle beam loss at the injection, transition, and extraction stages, employs perpendicularly biased garnet material for frequency tuning. The required range of the tuning is significantly wider than in previously built and tested tunable RF devices. As a result, the mag-netic field in the garnet comes fairly close to the gyromag-netic resonance line at the lower end of the frequency range. The chosen design concept of a tuner for the cavity cannot ensure uniform magnetic field in the garnet mate-rial;more » thus, it is important to know the static magnetic prop-erties of the material to avoid significant increase in the lo-cal RF loss power density. This report summarizes studies performed at Fermilab to understand variations in the mag-netic properties of the AL800 garnet material used to build the tuner of the cavity.« less
Material Concerns: Evaluating Sulfur Concrete for use in the Lunar Environment

NASA Technical Reports Server (NTRS)

Grugel, Richard N.; Toutanji, Houssam

2006-01-01

On Earth sulfur "concrete" is an established construction material that has good mechanical properties, generally better than Portland cement, and can be used in corrosive environments. Troilite (FeS) has been found on the moon and raises the question of using extracted sulfur as a lunar construction material, an attractive alternative to conventional concrete as it does not require water. Troilite reduction to elemental sulfur and using it to make concrete in a lunar setting has been previously discussed. However, little has been experimentally done to evaluate its performance in the extreme lunar environment. This study subjected sets of sulfur concrete samples, prepared using JSC-1 lunar simulant, to I ) extended periods of high vacuum and 2) extreme temperature cycles. Here an overview of sulfur concrete and experimentally assessed properties, put in context of the lunar environment, is presented and discussed.
Full extraction methods to retrieve effective refractive index and parameters of a bianisotropic metamaterial based on material dispersion models

NASA Astrophysics Data System (ADS)

Hsieh, Feng-Ju; Wang, Wei-Chih

2012-09-01

This paper discusses two improved methods in retrieving effective refractive indices, impedances, and material properties, such as permittivity (ɛ) and permeability (μ), of metamaterials. The first method modified from Kong's retrieval method allows effective constitutive parameters over all frequencies including the anti-resonant band, where imaginary parts of ɛ or μ are negative, to be solved. The second method is based on genetic algorithms and optimization of properly defined goal functions to retrieve parameters of the Drude and Lorentz dispersion models. Equations of effective refractive index and impedance at any reference planes are derived. Split ring resonator-rod based metamaterials operating in terahertz frequencies are designed and investigated with proposed methods. Retrieved material properties and parameters are used to regenerate S-parameters and compared with simulation results generated by cst microwave studio software.
Computational Challenges in the Analysis of Petrophysics Using Microtomography and Upscaling

NASA Astrophysics Data System (ADS)

Liu, J.; Pereira, G.; Freij-Ayoub, R.; Regenauer-Lieb, K.

2014-12-01

Microtomography provides detailed 3D internal structures of rocks in micro- to tens of nano-meter resolution and is quickly turning into a new technology for studying petrophysical properties of materials. An important step is the upscaling of these properties as micron or sub-micron resolution can only be done on the sample-scale of millimeters or even less than a millimeter. We present here a recently developed computational workflow for the analysis of microstructures including the upscaling of material properties. Computations of properties are first performed using conventional material science simulations at micro to nano-scale. The subsequent upscaling of these properties is done by a novel renormalization procedure based on percolation theory. We have tested the workflow using different rock samples, biological and food science materials. We have also applied the technique on high-resolution time-lapse synchrotron CT scans. In this contribution we focus on the computational challenges that arise from the big data problem of analyzing petrophysical properties and its subsequent upscaling. We discuss the following challenges: 1) Characterization of microtomography for extremely large data sets - our current capability. 2) Computational fluid dynamics simulations at pore-scale for permeability estimation - methods, computing cost and accuracy. 3) Solid mechanical computations at pore-scale for estimating elasto-plastic properties - computational stability, cost, and efficiency. 4) Extracting critical exponents from derivative models for scaling laws - models, finite element meshing, and accuracy. Significant progress in each of these challenges is necessary to transform microtomography from the current research problem into a robust computational big data tool for multi-scale scientific and engineering problems.
Effects of Increased Loading on In Vivo Tendon Properties: A Systematic Review

PubMed Central

WIESINGER, HANS-PETER; KÖSTERS, ALEXANDER; MÜLLER, ERICH; SEYNNES, OLIVIER R.

2015-01-01

ABSTRACT Introduction In vivo measurements have been used in the past two decades to investigate the effects of increased loading on tendon properties, yet the current understanding of tendon macroscopic changes to training is rather fragmented, limited to reports of tendon stiffening, supported by changes in material properties and/or tendon hypertrophy. The main aim of this review was to analyze the existing literature to gain further insights into tendon adaptations by extracting patterns of dose-response and time-course. Methods PubMed/Medline, SPORTDiscus, and Google Scholar databases were searched for studies examining the effect of training on material, mechanical, and morphological properties via longitudinal or cross-sectional designs. Results Thirty-five of 6440 peer-reviewed articles met the inclusion criteria. The key findings were i) the confirmation of a nearly systematic adaptation of tendon tissue to training, ii) the important variability in the observed changes in tendon properties between and within studies, and iii) the absence of a consistent incremental pattern regarding the dose-response or the time-course relation of tendon adaptation within the first months of training. However, long-term (years) training was associated with a larger tendon cross-sectional area, without any evidence of differences in material properties. Our analysis also highlighted several gaps in the existing literature, which may be addressed in future research. Conclusions In line with some cross-species observations about tendon design, tendon cross-sectional area allegedly constitutes the ultimate adjusting parameter to increased loading. We propose here a theoretical model placing tendon hypertrophy and adjustments in material properties as parts of the same adaptive continuum. PMID:25563908
Physiochemical and antioxidant properties of roselle-mango juice blends; effects of packaging material, storage temperature and time

PubMed Central

Mgaya-Kilima, Beatrice; Remberg, Siv Fagertun; Chove, Bernard Elias; Wicklund, Trude

2015-01-01

A study was conducted to determine the effects of packaging materials, seasonality, storage temperature and time on physiochemical and antioxidant properties of roselle-mango juice blends. Roselle extract (20%, 40%, 60%, and 80%) was mixed with mango juice and stored in glass and plastic bottles at 4°C and 28°C. Total soluble solids, pH, titratable acidity, reducing sugar, color, vitamin C, total monomeric anthocyanins, total phenols, and antioxidant activity (FRAP) were evaluated in freshly prepared juice, and after, 2, 4, and 6 months of storage. The results showed that total soluble solids, reducing sugars, and pH increased with storage times under different storage time, irrespective of packaging materials. The acidity, color, total monomeric anthocyanin, vitamin C, total phenols, and antioxidant activity decreased during storage irrespective of storage temperature and packaging material. Loss of anthocyanins, total phenols, and vitamin C content were higher in blends stored at 28°C than 4°C. PMID:25838888
From bacteria to mollusks: the principles underlying the biomineralization of iron oxide materials.

PubMed

Faivre, Damien; Godec, Tina Ukmar

2015-04-13

Various organisms possess a genetic program that enables the controlled formation of a mineral, a process termed biomineralization. The variety of biological material architectures is mind-boggling and arises from the ability of organisms to exert control over crystal nucleation and growth. The structure and composition of biominerals equip biomineralizing organisms with properties and functionalities that abiotically formed materials, made of the same mineral, usually lack. Therefore, elucidating the mechanisms underlying biomineralization and morphogenesis is of interdisciplinary interest to extract design principles that will enable the biomimetic formation of functional materials with similar capabilities. Herein, we summarize what is known about iron oxides formed by bacteria and mollusks for their magnetic and mechanical properties. We describe the chemical and biological machineries that are involved in controlling mineral precipitation and organization and show how these organisms are able to form highly complex structures under physiological conditions. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Biomaterials in search of a meniscus substitute.

PubMed

Rongen, Jan J; van Tienen, Tony G; van Bochove, Bas; Grijpma, Dirk W; Buma, Pieter

2014-04-01

The menisci fulfill key biomechanical functions in the tibiofemoral (knee) joint. Unfortunately meniscal injuries are quite common and most often treated by (partial) meniscectomy. However, some patients experience enduring symptoms, and, more importantly, it leads to an increased risk for symptomatic osteoarthritis. Over the past decades, researchers have put effort in developing a meniscal substitute able to prevent osteoarthritis and treat enduring clinical symptoms. Grossly, two categories of substitutes are observed: First, a resorbable scaffold mimicking biomechanical function which slowly degrades while tissue regeneration and organization is promoted. Second, a non resorbable, permanent implant which mimics the biomechanical function of the native meniscus. Numerous biomaterials with different (material) properties have been used in order to provide such a substitute. Nevertheless, a clinically applicable cartilage protecting material is not yet emerged. In the current review we provide an overview, and discuss, these different materials and extract recommendations regarding material properties for future developmental research. Copyright © 2014 Elsevier Ltd. All rights reserved.
Design, formulation, and evaluation of ginger medicated chewing gum

PubMed Central

Aslani, Abolfazl; Ghannadi, Alireza; Rostami, Farnaz

2016-01-01

Background: Various ginger compounds improve gastrointestinal problems and motion sickness. The main effects of ginger allocate to some phenolics such as gingerols and shogaols that act as their active agents. Chewing gums are among convenient dosage forms which patients prefer due to their advantages. Hence, this study tried to design, formulate, and evaluate ginger chewing gum of favorable taste and texture to avoid motion sickness and have gastro-protective and anti-oxidant effect. Materials and Methods: Dried ginger rhizomes were percolated to extract ginger compounds. Total phenolics were measured in 70% hydro-alcoholic extract of ginger by gallic and tannic acid standards using Folin–Ciocalteu’s reagent. Chewing gums containing 50 mg of concentrated extract were prepared. Content uniformity, weight variation, release pattern, organoleptic, and mechanical properties were evaluated. Results: Phenolic content was measured 61.50 ± 5.27 mg/g and 76.75 ± 5.45 mg/g of concentrated extract as gallic acid and tannic acid equivalents, respectively. Release pattern of formulations with different gum bases and sweeteners demonstrated almost 100% release of drug. Evaluation of organoleptic properties was on 10 healthy volunteers and later prepared formulations exhibited better characteristics. Formulations without any flavorants have higher acceptability. Evaluation of mechanical properties showed higher stiffness of F15. Conclusion: Ginger chewing gum comprises admissible properties to be used as a modern drug delivery system due to its advantageous results in motion sickness. It passed all the specified tests for an acceptable chewing gum. Thus, it may be successfully produced to help GI problems. PMID:27563640
Antioxidant activities of distiller dried grains with solubles as protein films containing tea extracts and their application in the packaging of pork meat.

PubMed

Yang, Hyun-Ju; Lee, Ji-Hyeon; Won, Misun; Song, Kyung Bin

2016-04-01

Distiller dried grains with solubles (DDGS) as protein (DP) films were prepared. Additionally, to prepare anti-oxidant films, green tea extract (GTE), oolong tea extract (OTE), and black tea extract (BTE) were incorporated into the DP films. Consequently, the incorporation of the tea extracts did not alter the physical properties of the films much, whereas the antioxidant activities, such as ABTS and DPPH radical scavenging activities were observed. To apply the DP films containing tea extracts to food packaging, pork meat was wrapped with the films and stored at 4 °C for 10 d. During storage, the pork meat wrapped with the DP films containing GTE, OTE, and BTE had less lipid oxidation than did the control. Among the tea extracts, the DP film containing GTE had the greatest antioxidant activity. These results indicate that the DP films containing green tea extracts can be utilized as an anti-oxidative packaging material for pork meat. Copyright © 2015 Elsevier Ltd. All rights reserved.
Complex Permittivity of Planar Building Materials Measured With an Ultra-Wideband Free-Field Antenna Measurement System.

PubMed

Davis, Ben; Grosvenor, Chriss; Johnk, Robert; Novotny, David; Baker-Jarvis, James; Janezic, Michael

2007-01-01

Building materials are often incorporated into complex, multilayer macrostructures that are simply not amenable to measurements using coax or waveguide sample holders. In response to this, we developed an ultra-wideband (UWB) free-field measurement system. This measurement system uses a ground-plane-based system and two TEM half-horn antennas to transmit and receive the RF signal. The material samples are placed between the antennas, and reflection and transmission measurements made. Digital signal processing techniques are then applied to minimize environmental and systematic effects. The processed data are compared to a plane-wave model to extract the material properties with optimization software based on genetic algorithms.
Precision measurements of linear scattering density using muon tomography

NASA Astrophysics Data System (ADS)

Åström, E.; Bonomi, G.; Calliari, I.; Calvini, P.; Checchia, P.; Donzella, A.; Faraci, E.; Forsberg, F.; Gonella, F.; Hu, X.; Klinger, J.; Sundqvist Ökvist, L.; Pagano, D.; Rigoni, A.; Ramous, E.; Urbani, M.; Vanini, S.; Zenoni, A.; Zumerle, G.

2016-07-01

We demonstrate that muon tomography can be used to precisely measure the properties of various materials. The materials which have been considered have been extracted from an experimental blast furnace, including carbon (coke) and iron oxides, for which measurements of the linear scattering density relative to the mass density have been performed with an absolute precision of 10%. We report the procedures that are used in order to obtain such precision, and a discussion is presented to address the expected performance of the technique when applied to heavier materials. The results we obtain do not depend on the specific type of material considered and therefore they can be extended to any application.
Starch extraction process coupled to protein recovery from leguminous tuberous roots (Pachyrhizus ahipa).

PubMed

Díaz, Andrea; Dini, Cecilia; Viña, Sonia Z; García, María A

2016-11-05

The objective of this work was to fit together the starch extraction from Pachyrhizus ahipa roots and the recovery of the proteins present in these storage organs, making an improved use of this novel raw material. The replacement of water by buffer PO4(-3)/NaCl as solvent in the first extraction steps improved protein extraction without lowering the starch yield. The starches obtained from the traditional and the proposed methods exhibited some differences in appearance and technological and thermal properties, which were endorsed to the adjustment in the methodology of extraction rather than to the use of buffer as solvent. Thus, P. ahipa starch obtaining procedure could be coupled to protein extraction with a minimum change in the methodology. This innovation did not significantly shift the characteristics of the starch obtained and allowed to obtain a protein yield of 135.7mg BSA equivalent protein/100g of fresh roots. Copyright © 2016 Elsevier Ltd. All rights reserved.
Anti-cobra venom activity of plant Andrographis paniculata and its comparison with polyvalent anti-snake venom

PubMed Central

Premendran, S. Jhon; Salwe, Kartik J.; Pathak, Swanand; Brahmane, Ranjana; Manimekalai, K.

2011-01-01

Background: To investigate the anti-cobra venom effect of alcoholic extract of Andrographis paniculata. Materials and Methods: After calculating the LD99 of snake venom, the venom-neutralizing ability of plant extract at the dose 1 g/kg and 2 g/kg was determined using in vitro and in vivo methods. The alleviation in the mean survival time of the animals were used to infer the antivenom property of the drug after challenging with LD99 of snake venom. Results: The ethanolic extract of plant A. paniculata significantly increases mean survival time and the protection fold, but could not protect animals from death when used alone. The higher dose, i.e., 2 g/kg was found better than that of the lower. ASV was found more effective than the plant extract. When ASV was given along with plant extract, it potentiates its effect. Conclusion: The observation demonstrates the anti-cobra venom activity of ethanolic extract of A. paniculata which is comparable with ASV. PMID:22346236
Determining the Gaussian Modulus and Edge Properties of 2D Materials: From Graphene to Lipid Bilayers

NASA Astrophysics Data System (ADS)

Zelisko, Matthew; Ahmadpoor, Fatemeh; Gao, Huajian; Sharma, Pradeep

2017-08-01

The dominant deformation behavior of two-dimensional materials (bending) is primarily governed by just two parameters: bending rigidity and the Gaussian modulus. These properties also set the energy scale for various important physical and biological processes such as pore formation, cell fission and generally, any event accompanied by a topological change. Unlike the bending rigidity, the Gaussian modulus is, however, notoriously difficult to evaluate via either experiments or atomistic simulations. In this Letter, recognizing that the Gaussian modulus and edge tension play a nontrivial role in the fluctuations of a 2D material edge, we derive closed-form expressions for edge fluctuations. Combined with atomistic simulations, we use the developed approach to extract the Gaussian modulus and edge tension at finite temperatures for both graphene and various types of lipid bilayers. Our results possibly provide the first reliable estimate of this elusive property at finite temperatures and appear to suggest that earlier estimates must be revised. In particular, we show that, if previously estimated properties are employed, the graphene-free edge will exhibit unstable behavior at room temperature. Remarkably, in the case of graphene, we show that the Gaussian modulus and edge tension even change sign at finite temperatures.
Taiwanese native plants inhibit matrix metalloproteinase-9 activity after ultraviolet B irradiation.

PubMed

Lee, Yueh-Lun; Lee, Mei-Hsien; Chang, Hsiu-Ju; Huang, Po-Yuan; Huang, I-Jen; Cheng, Kur-Ta; Leu, Sy-Jye

2009-03-06

Medicinal plants have long been used as a source of therapeutic agents. They are thought to be important anti-aging ingredients in prophylactic medicines. The aim of this study was to screen extracts from Taiwanese plant materials for phenolic contents and measure the corresponding matrix metalloproteinase-9 (MMP-9) activity. We extracted biological ingredients from eight plants native to Taiwan (Alnus formosana, Diospyros discolor, Eriobotrya deflex, Machilus japonica, Pyrrosia polydactylis, Pyrus taiwanensis, Vitis adstricta, Vitis thunbergii). Total phenolic content was measured using the Folin-Ciocalteu method. MMP-9 activities were measured by gelatin zymography. The extracted yields of plants ranged from 3.7 % to 16.9 %. The total phenolic contents ranged from 25.4 to 36.8 mg GAE/g dry material. All of these extracts (except Vitis adstricta Hance) were shown to inhibit MMP-9 activity of WS-1 cell after ultraviolet B irradiation. These findings suggest that total phenolic content may influence MMP-9 activity and that some of the plants with higher phenolic content exhibited various biological activities that could serve as potent inhibitors of the ageing process in the skin. This property might be useful in the production of cosmetics.
Systematic comparison of static and dynamic headspace sampling techniques for gas chromatography.

PubMed

Kremser, Andreas; Jochmann, Maik A; Schmidt, Torsten C

2016-09-01

Six automated, headspace-based sample preparation techniques were used to extract volatile analytes from water with the goal of establishing a systematic comparison between commonly available instrumental alternatives. To that end, these six techniques were used in conjunction with the same gas chromatography instrument for analysis of a common set of volatile organic carbon (VOC) analytes. The methods were thereby divided into three classes: static sampling (by syringe or loop), static enrichment (SPME and PAL SPME Arrow), and dynamic enrichment (ITEX and trap sampling). For PAL SPME Arrow, different sorption phase materials were also included in the evaluation. To enable an effective comparison, method detection limits (MDLs), relative standard deviations (RSDs), and extraction yields were determined and are discussed for all techniques. While static sampling techniques exhibited sufficient extraction yields (approx. 10-20 %) to be reliably used down to approx. 100 ng L(-1), enrichment techniques displayed extraction yields of up to 80 %, resulting in MDLs down to the picogram per liter range. RSDs for all techniques were below 27 %. The choice on one of the different instrumental modes of operation (aforementioned classes) was thereby the most influential parameter in terms of extraction yields and MDLs. Individual methods inside each class showed smaller deviations, and the least influences were observed when evaluating different sorption phase materials for the individual enrichment techniques. The option of selecting specialized sorption phase materials may, however, be more important when analyzing analytes with different properties such as high polarity or the capability of specific molecular interactions. Graphical Abstract PAL SPME Arrow during the extraction of volatile analytes from the headspace of an aqueous sample.
Evaluation of antimicrobial properties of cork.

PubMed

Gonçalves, Filipa; Correia, Patrícia; Silva, Susana P; Almeida-Aguiar, Cristina

2016-02-01

Cork presents a range of diverse and versatile properties making this material suitable for several and extremely diverse industrial applications. Despite the wide uses of cork, its antimicrobial properties and potential applications have deserved little attention from industry and the scientific community. Thus, the main purpose of this work was the evaluation of the antibacterial properties of cork, by comparison with commercially available antimicrobial materials (Ethylene-Vinyl Acetate copolymer and a currently used antimicrobial commercial additive (ACA)), following the previous development and optimization of a method for such antimicrobial assay. The AATCC 100-2004 standard method, a quantitative procedure developed for the assessment of antimicrobial properties in textile materials, was used as reference and optimized to assess cork antibacterial activity. Cork displayed high antibacterial activity against Staphylococcus aureus, with a bacterial reduction of almost 100% (96.93%) after 90 minutes of incubation, similar to the one obtained with ACA. A more reduced but time-constant antibacterial action was observed against Escherichia coli (36% reduction of the initial number of bacterial colonies). To complement this study, antibacterial activity was further evaluated for a water extract of cork and an MIC of 6 mg mL(-1) was obtained against the reference strain S. aureus. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
Formulation and characterization of Turkish oregano microcapsules prepared by spray-drying technology.

PubMed

Baranauskaite, Juste; Ivanauskas, Liudas; Masteikova, Ruta; Kopustinskiene, Dalia; Baranauskas, Algirdas; Bernatoniene, Jurga

2017-09-01

The aim of this study was optimization of spray-drying process conditions for microencapsulation of Turkish oregano extract. Different concentrations of maltodextrin and gum arabic as encapsulating agents (wall material) as well as influence of selected processing variables were evaluated. The optimal conditions were maintained on the basis of the load of main bioactive compounds - ursolic, rosmarinic acids and carvacrol - in prepared microparticles after comparison of all significant response variables using desirability function. Physicomechanical properties of powders such as flowability, wettability, solubility, moisture content as well as product yield, encapsulation efficiency (EE), density, morphology and size distribution of prepared microparticles have been determined. The results demonstrated that the optimal conditions for spray-drying mixture consisted of two parts of wall material solution and one part of ethanolic oregano extract when the feed flow rate was 40 mL/min and air inlet temperature -170 °C. Optimal concentration of wall materials in solution was 20% while the ratio of maltodextrin and gum arabic was 8.74:1.26.
Preparation of C₁₈-functionalized magnetic polydopamine microspheres for the enrichment and analysis of alkylphenols in water samples.

PubMed

Wang, Xianying; Deng, Chunhui

2016-02-01

In this work, C18-functionalized magnetic polydopamine microspheres (Fe3O4@PDA@C18) were successfully synthesized and applied to the analysis of alkylphenols in water samples. The magnetic Fe3O4 particles coated with hydrophilic surface were synthesized via a solvothermal reaction and the self-polymerization of dopamine. And then the C18 groups were fabricated by a silylanization method. Benefit from the merits of Fe3O4 particles, polydopamine coating and C18 groups, the Fe3O4@PDA@C18 material possessed several properties of super magnetic responsiviness, good water dispersibility, π-electron system and hydrophobic C18 groups. Thus, the materials had great potential to be developed as the adsorbent for the magnetic solid-phase extraction (MSPE) technique. Here, we selected three kinds of alkylphenols (4-tert-octylphenol, 4-n-nonylphenol, 4-n-octylphenol) to be the target analyst for evaluating the performance of the prepared material. In this study, various extraction parameters were investigated and optimized, such as pH values of water sample solution, amount of adsorbents, adsorption and desorption time, the species of desorption solution. Meanwhile, the method validations were studied, including linearity, limit of detection and method precision. From the results, Fe3O4@PDA@C18 composites were successfully applied as the adsorbents for the extraction of alkylphenols in water samples. The proposed material provided an approach for a simple, rapid magnetic solid-phase extraction for hydrophobic compounds in environmental samples. Copyright © 2015 Elsevier B.V. All rights reserved.
Physical-Mechanical characterization of cosmetic formulations and correlation between instrumental measurements and sensorial properties.

PubMed

Calixto, L S; Maia Campos, P M B G

2017-10-01

The correct choice of raw materials in the development of cosmetic formulations is essential for obtaining stable and pleasant skin care products. Therefore, rheological, texture and sensory analyses are important to understand the behaviour and stability of the formulations. In this context, the aim of this study was to develop cosmetic formulations containing or not (vehicle) UV filters and chicory root extract, to evaluate their stability as well as to characterize their physical and texture properties and correlate them with the sensory attributes. Four formulations containing organic UV filters and chicory extract, each alone or in combination, were developed and evaluated for 180 days with a cone and plate rheometer, a texture analyzer and consumer's sensorial analysis. Thus, the data obtained were correlated to observe the different influences. The developed formulations remained stable after 180 days regarding macroscopic aspects, organoleptic characteristics and pH values. The addition of the UV filters alone and in combination with the active substance resulted in significant increases in rheology properties, viscosity and consistency. The formulation with the active ingredient showed significant decreases in the texture parameters after 180 days, mainly due to its polysaccharide inulin. All formulations obtained high scores in sensorial parameters. A strong correlation was mainly found between spreadability and work of shear, and between the texture parameters. The raw materials strongly influenced the physical, texture and sensorial parameters. Finally, the UV filters showed a greater influence on the results of the formulations than the chicory root extract. In conclusion, the association of the mentioned methods allows the correct choice of ingredients and their combinations. © 2017 Society of Cosmetic Scientists and the Société Française de Cosmétologie.
Materials Data Science: Current Status and Future Outlook

NASA Astrophysics Data System (ADS)

Kalidindi, Surya R.; De Graef, Marc

2015-07-01

The field of materials science and engineering is on the cusp of a digital data revolution. After reviewing the nature of data science and Big Data, we discuss the features of materials data that distinguish them from data in other fields. We introduce the concept of process-structure-property (PSP) linkages and illustrate how the determination of PSPs is one of the main objectives of materials data science. Then we review a selection of materials databases, as well as important aspects of materials data management, such as storage hardware, archiving strategies, and data access strategies. We introduce the emerging field of materials data analytics, which focuses on data-driven approaches to extract and curate materials knowledge from available data sets. The critical need for materials e-collaboration platforms is highlighted, and we conclude the article with a number of suggestions regarding the near-term future of the materials data science field.
EVALUATION OF THE CHELATING EFFECT OF METHANOLIC EXTRACT OF CORIANDRUM SATIVUM AND ITS FRACTIONS ON WISTAR RATS POISONED WITH LEAD ACETATE

PubMed Central

Téllez-López, Miguel Ángel; Mora-Tovar, Gabriela; Ceniceros-Méndez, Iromi Marlen; García-Lujan, Concepción; Puente-Valenzuela, Cristo Omar; Vega-Menchaca, María del Carmen; Serrano-Gallardo, Luis Benjamín; Garza, Rubén García; Morán-Martínez, Javier

2017-01-01

Background: The rate of lead poisoning has decreased in recent years due to increased health control in industries that use this metal. However, it is still a public health problem worldwide. The use of various plants with chelating properties has been a topic of research today. In traditional medicine, it is said that Coriandrum sativum has chelating properties, but there is no scientific evidence to support this fact. The purpose of this research is to evaluate the chelating effect of methanol extract of coriander and its fractions on Wistar rats intoxicated with lead. Materials and Methods: In this research, male Wistar rats were poisoned with 50 mg/kg of lead acetate and treated with 50 mg/kg of methanol extract and its fractions. The extract and its fractions were administered to four treatment groups. Positive and negative controls were established. Hemoglobin, hematocrit and lead concentrations were analyzed; liver was evaluated histologically in control and treatment groups. Results: The methanol extract of coriander presented a LD50 >1000 mg/dL. The group administered with the methanol extract showed significant difference in the levels of hemoglobin and hematocrit compared to the negative control group. Lead concentration in treatment groups showed a decrease compared to the positive control. Histological evaluation of tissue showed less damage in groups administered with methanolic extract and its fractions compared to the positive control which presented structural alterations. Conclusion: Coriander extracts protect liver and lower lead concentration in rats intoxicated with lead in contrast to the positive control group. PMID:28573226
Model based defect characterization in composites

NASA Astrophysics Data System (ADS)

Roberts, R.; Holland, S.

2017-02-01

Work is reported on model-based defect characterization in CFRP composites. The work utilizes computational models of the interaction of NDE probing energy fields (ultrasound and thermography), to determine 1) the measured signal dependence on material and defect properties (forward problem), and 2) an assessment of performance-critical defect properties from analysis of measured NDE signals (inverse problem). Work is reported on model implementation for inspection of CFRP laminates containing multi-ply impact-induced delamination, with application in this paper focusing on ultrasound. A companion paper in these proceedings summarizes corresponding activity in thermography. Inversion of ultrasound data is demonstrated showing the quantitative extraction of damage properties.
Ethanolic extract of propolis for biodegradable films packaging enhanced with chitosan

NASA Astrophysics Data System (ADS)

Ismail, M. I.; Roslan, A.; Saari, N. S.; Hashim, K. H.; Kalamullah, M. R.

2017-09-01

The use of industrial organic waste which are chitosan and propolis as materials for the development of biodegradable and active packaging is economical and environmentally appealing. Processing of propolis-chitosan film can minimize waste, and produce low-cost added value biopolymer packaging films for targeted applications. This aims of this research is to develop and characterize a biodegradable films by incorporating chitosan with propolis extract to enhance the functional properties for potential use as active food packaging. The film's moisture content, solubility and antimicrobial activity increase due to increasing volume of propolis extract which are 0 ml, 1.2 ml and 2.4 ml of propolis extract. Propolis-chitosan film with 2.4 ml of propolis extract is more soluble in water compared to propolis-chitosan film with 0 ml of propolis extract and 1.2 ml of propolis extract. The higher the volume of the propolis extract used, the higher the solubility of film in the water. The moisture content also will increase when higher volume of propolis extract used. Characterization of moisture content, solubility and antimicrobial activities revealed the benefits of adding propolis extract into chitosan films and the potential of using the developed film as active food packaging.
Technique for measurement of characteristic impedance and propagation constant for porous materials

NASA Astrophysics Data System (ADS)

Jung, Ki Won; Atchley, Anthony A.

2005-09-01

Knowledge of acoustic properties such as characteristic impedance and complex propagation constant is useful to characterize the acoustic behaviors of porous materials. Song and Bolton's four-microphone method [J. Acoust. Soc. Am. 107, 1131-1152 (2000)] is one of the most widely employed techniques. In this method two microphones are used to determine the complex pressure amplitudes for each side of a sample. Muehleisen and Beamer [J. Acoust. Soc. Am. 117, 536-544 (2005)] improved upon a four-microphone method by interchanging microphones to reduce errors due to uncertainties in microphone response. In this paper, a multiple microphone technique is investigated to reconstruct the pressure field inside an impedance tube. Measurements of the acoustic properties of a material having square cross-section pores is used to check the validity of the technique. The values of characteristic impedance and complex propagation constant extracted from the reconstruction agree well with predicted values. Furthermore, this technique is used in investigating the acoustic properties of reticulated vitreous carbon (RVC) in the range of 250-1100 Hz.
Modification of fish skin collagen film and absorption property of tannic acid.

PubMed

Liu, Haiying; Zhao, Lu; Guo, Shidong; Xia, Yu; Zhou, Peng

2014-06-01

Fish collagen is a biomacromolecule material and is usually used as a clarifying agent. However, fish collagen is not recyclable, and sedimentation usually occurs in the clarification process using fish collagen so that the filtration process is inevitable. This work aimed to provide a recyclable modified fish skin collagen film (MFCF) for adsorption of tannic acids. The collagen from channel catfish skin was extracted and used for preparation of the fish skin collagen film (FCF) and MFCF. The result indicated that the mechanical properties of MFCF were improved by addition of 2 ml/L glycerol, 6 ml/L polyvinyl alcohol (PVA) and 2 ml/L glutaraldehyde in 15 g/L collagen solution. As the most important property of adsorption material, the hydroscopicity of MFCF was only 54%, significantly lower than that of FCF (295%). Therefore, MFCF would not collapse in water. The infrared and thermal properties of MFCF were also investigated in this work. Results indicated that, in comparison to FCF, the physical and chemical properties of MFCF had been improved significantly. MFCF had higher shrink temperature (79.3 °C) and it did not collapse in distilled water at normal temperature. Furthermore, absorption and desorption properties of tannic acid were studied. MFCF showed good capability of absorption and desorption of tannic acid, which leaded to the suggestion that MFCF could have potential applications in adsorption material.

Electron Dynamics in Nanostructures in Strong Laser Fields

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kling, Matthias

2014-09-11

The goal of our research was to gain deeper insight into the collective electron dynamics in nanosystems in strong, ultrashort laser fields. The laser field strengths will be strong enough to extract and accelerate electrons from the nanoparticles and to transiently modify the materials electronic properties. We aimed to observe, with sub-cycle resolution reaching the attosecond time domain, how collective electronic excitations in nanoparticles are formed, how the strong field influences the optical and electrical properties of the nanomaterial, and how the excitations in the presence of strong fields decay.
An insect-inspired bionic sensor for tactile localization and material classification with state-dependent modulation

PubMed Central

Patanè, Luca; Hellbach, Sven; Krause, André F.; Arena, Paolo; Dürr, Volker

2012-01-01

Insects carry a pair of antennae on their head: multimodal sensory organs that serve a wide range of sensory-guided behaviors. During locomotion, antennae are involved in near-range orientation, for example in detecting, localizing, probing, and negotiating obstacles. Here we present a bionic, active tactile sensing system inspired by insect antennae. It comprises an actuated elastic rod equipped with a terminal acceleration sensor. The measurement principle is based on the analysis of damped harmonic oscillations registered upon contact with an object. The dominant frequency of the oscillation is extracted to determine the distance of the contact point along the probe and basal angular encoders allow tactile localization in a polar coordinate system. Finally, the damping behavior of the registered signal is exploited to determine the most likely material. The tactile sensor is tested in four approaches with increasing neural plausibility: first, we show that peak extraction from the Fourier spectrum is sufficient for tactile localization with position errors below 1%. Also, the damping property of the extracted frequency is used for material classification. Second, we show that the Fourier spectrum can be analysed by an Artificial Neural Network (ANN) which can be trained to decode contact distance and to classify contact materials. Thirdly, we show how efficiency can be improved by band-pass filtering the Fourier spectrum by application of non-negative matrix factorization. This reduces the input dimension by 95% while reducing classification performance by 8% only. Finally, we replace the FFT by an array of spiking neurons with gradually differing resonance properties, such that their spike rate is a function of the input frequency. We show that this network can be applied to detect tactile contact events of a wheeled robot, and how detrimental effects of robot velocity on antennal dynamics can be suppressed by state-dependent modulation of the input signals. PMID:23055967
A comparative study of sludges from Athabasca and northern Holland

DOE Office of Scientific and Technical Information (OSTI.GOV)

Muszalski, P.; Hornof, V.; Kotlyar, L.

1995-12-31

The tailings produced during bitumen separation from Athabasca oil sands have a high water holdings capacity. While chemical treatment will increase the rate of settling of these tailings it has little effect on the final degree of solids consolidation. These characteristics have been attributed to the presence of ultra fine (< 0.2 {mu}m), aluminosilicate clays. Ultra fines readily flocculate to form gels within which both fine and coarse particles may be embedded. In this work a comparison has been made between the properties of fine tailings from a bitumen extraction plant with those of {open_quotes}difficult{close_quotes} sludges from other extractive industries.more » The {open_quotes}difficult{close_quotes} sludges, from plants in northern Holland, were supplied, courtesy of Suncor Inc. There was a similarity between the amount and size distribution of solids in all the samples tested. However, as evidenced by a greater degree of stability to mechanical stress, the structure of the Dutch sludges was stronger than that observed for the Suncor material. This property has been attributed to the presence of natural organic matter (NOM) or humic material, which is noted for its aggregation and binding properties. In the presence of such organic matter specific chemical interactions between colloidal particles and organic molecules, rather than DLVO interactions, are of primary importance.« less
In vitro caries-inhibitory properties of a silver cermet.

PubMed

Swift, E J

1989-06-01

Recurrent caries is one of the primary causes of failure of dental restorations. One method for reducing the frequency and severity of this problem is the use of fluoride-releasing restorative materials. The glass-ionomer cements are a type of fluoride-releasing material. They have been used extensively in recent years for a variety of clinical applications. However, in comparison with other restorative materials such as amalgam and composite resins, glass ionomers have relatively poor physical properties. Sintering of silver particles to glass-ionomer powder is a means of improving these physical properties. The sintered material is called a silver-glass ionomer or silver cermet. This study examined the in vitro caries-inhibitory potential of a silver cement by means of two methods. First, long-term fluoride release was measured. Second, an artificial caries system was used for evaluation of caries inhibition by cerment restorations in extracted teeth. In comparison with a standard glass-ionomer restorative material, fluoride release from the cermet material was significantly less throughout a 12-month period. The results from the artificial caries system indicated that this decreased fluoride release corresponded with a lesser degree of caries inhibition. Lesions around cermet restorations in both enamel and root surfaces were significantly more severe than those around conventional glass-ionomer restorations. However, in comparison with amalgam and composite resin restorations, the cermet did have some cariostatic activity.
Antioxidant, Anti-inflammatory, Analgesic Properties, and Phytochemical Characterization of Stem Bark Extract and Fractions of Anthocleista nobilis

PubMed Central

Ngwoke, Kenneth Gerald; Akwagbulam, Amaka Godsaveus; Erhirhie, Ernest Oghenesuvwe; Ajaghaku, Daniel Lotanna; Okoye, Festus Basden Chiedu; Esimone, Charles Okechukwu

2018-01-01

Background: Anthocleista nobilis (Loganiaceae) is used by Mbano people of Imo State, Nigeria, for the treatment of various ailments Objective: The aim of this study is to evaluate the antioxidant, anti-inflammatory, and analgesic properties of the methanol extract, fractions, and subfractions of A. nobilis. Materials and Methods: The powdered stem bark was extracted with methanol and sequentially fractionated into n-hexane, ethyl acetate, and butanol fractions. The constituents of the fractions were analyzed using high-pressure liquid chromatography (HPLC), and the components were identified by dereplication. Antioxidant potential of the extracts and fractions was investigated using 2,2-diphenyl-1-picrylhydrazyl free-radical scavenging method. Anti-inflammatory and analgesic activities of the extract and fractions were also investigated using xylene-induced inflammation and acetic acid-induced writhing models, respectively. Results: A total of five compounds isovitexin (Rt = 18.77 min), isovitexin-2''-O-xyl (Rt = 19.68 min), p-Hydroxybenzoic acid (Rt = 11.88 min), Sarasinoside L (Rt = 19.64 min), isovitexin (Rt = 18.77), and apigenin monoglycoside (Rt = 19.64 min) were identified by HPLC analysis and dereplication. The ethyl acetate fraction and subfraction elicited the best anti-inflammatory activity. The ethyl acetate subfraction also inhibited acetic acid-induced pain by 79% and 85.0% at the doses of 100 mg/kg and 200 mg/kg, respectively, which was better than 71.1% and 81.3% observed for diclofenac at similar doses. Conclusion: A. nobilis could be a potential source of anti-inflammatory and analgesic lead compounds. SUMMARY The extract, fractions and subfractions of Anthocleista nobilis were screened or antioxidant, anti-inflammatory and Analgesic properties in vitro and in mice models. Some of the components were identified by dereplication after HPLC analysis. The results demonstrated potent anti-inflammatory and analgesic property of the extracts and fractions. The dereplication analysis also identified vitexin and related compounds. Abbreviation used: HPLC: High performance Liquid Chromatography; VLC: Vacuum Liquid Chromatography; DPPH: 2,2-Diphenyl-1-pycrylhydrazine; SPSS: Statistical Package for the Social Sciences; ROS: Reactive Oxygen Species PMID:29568192
Evaluation of the field-effect carrier mobility in single-grain (and polycrystalline) organic semconductors

NASA Astrophysics Data System (ADS)

Kwok, H. L.

2005-08-01

Mobility in single-grain and polycrystalline organic field-effect transistors (OFETs) is of interest because it affects the performance of these devices. While reasonable values of the hole mobility has been measured in pentacene OFETs, relatively speaking, our understanding of the detailed transport mechanisms is somewhat weak and there is a lack of precise knowledge on the effects of the materials parameters such as the site spacing, the localization length, the rms width of the density of states (DOS), the escape frequency, etc. This work attempts to analyze the materials parameters of pentacene OFETs extracted from data reported in the literature. In this work, we developed a model for the mobility parameter from first principle and extracted the relevant materials parameters. According to our analyses, the transport mechanisms in the OFETs are fairly complex and the electrical properties are dominated by the properties of the trap states. As observed, the single-grain OFETs having smaller values of the rms widths of the DOS (in comparison with the polycrystalline OFETs) also had higher hole mobilities. Our results showed that increasing the gate bias could have a similar but smaller effect. Potentially, increasing the escape frequency is a more effective way to raise the hole mobility and this parameter appears to be affected by changes in the molecular structure and in the degree of "disorder".
Compression and Reswelling of Microgel Particles after an Osmotic Shock

NASA Astrophysics Data System (ADS)

Sleeboom, Jelle J. F.; Voudouris, Panayiotis; Punter, Melle T. J. J. M.; Aangenendt, Frank J.; Florea, Daniel; van der Schoot, Paul; Wyss, Hans M.

2017-09-01

We use dedicated microfluidic devices to expose soft hydrogel particles to a rapid change in the externally applied osmotic pressure and observe a surprising, nonmonotonic response: After an initial rapid compression, the particle slowly reswells to approximately its original size. We theoretically account for this behavior, enabling us to extract important material properties from a single microfluidic experiment, including the compressive modulus, the gel permeability, and the diffusivity of the osmolyte inside the gel. We expect our approach to be relevant to applications such as controlled release, chromatography, and responsive materials.
An Undergraduate Laboratory Experiment that Utilizes a Glass Fiber Filter Assay to Determine the Steroid Specificity and Equilibrium Binding Properties of Glucocorticoid Receptors.

ERIC Educational Resources Information Center

John, Nancy J.; Firestone, Gary L.

1987-01-01

Describes two complementary laboratory exercises that use the glass fiber assay to assess receptor specificity and hormone binding affinity in rat liver cytoplasmic extracts. Details the methods, materials and protocol of the experiments. Discusses the basic concepts illustrated and the feasibility of using the experiments at the undergraduate…
Preparation of hollow mesoporous carbon spheres and their performances for electrochemical applications

NASA Astrophysics Data System (ADS)

Ariyanto, T.; Zhang, G. R.; Kern, A.; Etzold, B. J. M.

2018-03-01

Hollow carbon materials have received intensive attention for energy storage/conversion applications due to their attractive properties of high conductivity, high surface area, large void and short diffusion pathway. In this work, a novel hollow mesoporous material based on carbide-derived carbon (CDC) is presented. CDC is a new class of carbon material synthesized by the selective extraction of metals from metal carbides. With a two-stage extraction procedure of carbides with chlorine, firstly hybrid core-shell carbon particles were synthesized, i.e. mesoporous/graphitic carbon shells covering microporous/amorphous carbon cores. The amorphous cores were then selectively removed from particles by a careful oxidative treatment utilizing its low thermal characters while the more stable carbon shells remained, thus resulting hollow particles. The characterization methods (e.g. N2 sorption, Raman spectroscopy, temperature-programmed oxidation and SEM) proved the successful synthesis of the aspired material. In electric double-layer capacitor (EDLC) testing, this novel hollow core material showed a remarkable enhancement of EDLC’s rate handling ability (75% at a high scan rate) with respect to an entirely solid-mesoporous material. Furthermore, as a fuel cell catalyst support the material showed higher Pt mass activity (a factor of 1.8) compared to a conventional carbon support for methanol oxidation without noticeably decreasing activity in a long-term testing. Therefore, this carbon nanostructure shows great promises as efficient electrode materials for energy storage and conversion systems.
Interrogation of ethnomedicinal plants for synthetic lethality effects in combination with deficiency in the DNA repair endonuclease RAD1 using a yeast cell-based assay.

PubMed

Aung, Hsu Mon; Huangteerakul, Chananya; Panvongsa, Wittaya; Jensen, Amornrat N; Chairoungdua, Arthit; Sukrong, Suchada; Jensen, Laran T

2018-09-15

Plant materials used in this study were selected based on the ethnobotanical literature. Plants have either been utilized by Thai practitioners as alternative treatments for cancer or identified to exhibit anti-cancer properties. To screen ethnomedicinal plants using a yeast cell-based assay for synthetic lethal interactions with cells deleted for RAD1, the yeast homologue of human ERCC4 (XPF) MATERIALS AND METHODS: Ethanolic extracts from thirty-two species of medicinal plants utilized in Thai traditional medicine were screened for synthetic lethal/sick interactions using a yeast cell-based assay. Cell growth was compared between the parental strain and rad1∆ yeast following exposure to select for specific toxicity of plant extracts. Candidate extracts were further examined for the mode of action using genetic and biochemical approaches. Screening a library of ethanolic extracts from medicinal plants identified Bacopa monnieri and Colubrina asiatica as having synthetic lethal effects in the rad1∆ cells but not the parental strain. Synthetic lethal effects for B. monneiri extracts were more apparent and this plant was examined further. Genetic analysis indicates that pro-oxidant activities and defective excision repair pathways do not significantly contribute to enhanced sensitivity to B. monneiri extracts. Exposure to B. monneiri extracts resulted in nuclear fragmentation and elevated levels of ethidium bromide staining in rad1∆ yeast suggesting promotion of an apoptosis-like event. Growth inhibition also observed in the human Caco-2 cell line suggesting the effects of B. monnieri extracts on both yeast and human cells may be similar. B. monneiri extracts may have utility in treatment of colorectal cancers that exhibit deficiency in ERCC4 (XPF). Copyright © 2018 Elsevier B.V. All rights reserved.
Effect of degumming time on silkworm silk fibre for biodegradable polymer composites

NASA Astrophysics Data System (ADS)

Ho, Mei-po; Wang, Hao; Lau, Kin-tak

2012-02-01

Recently, many studies have been conducted on exploitation of natural materials for modern product development and bioengineering applications. Apart from plant-based materials (such as sisal, hemp, jute, bamboo and palm fibre), animal-based fibre is a kind of sustainable natural materials for making novel composites. Silkworm silk fibre extracted from cocoon has been well recognized as a promising material for bio-medical engineering applications because of its superior mechanical and bioresorbable properties. However, when producing silk fibre reinforced biodegradable/bioresorbable polymer composites, hydrophilic sericin has been found to cause poor interfacial bonding with most polymers and thus, it results in affecting the resultant properties of the composites. Besides, sericin layers on fibroin surface may also cause an adverse effect towards biocompatibility and hypersensitivity to silk for implant applications. Therefore, a proper pre-treatment should be done for sericin removal. Degumming is a surface modification process which allows a wide control of the silk fibre's properties, making the silk fibre possible to be used for the development and production of novel bio-composites with unique/specific mechanical and biodegradable properties. In this paper, a cleaner and environmentally friendly surface modification technique for tussah silk in polymer based composites is proposed. The effectiveness of different degumming parameters including degumming time and temperature on tussah silk is discussed through the analyses of their mechanical and morphological properties. Based on results obtained, it was found that the mechanical properties of tussah silk are affected by the degumming time due to the change of the fibre structure and fibroin alignment.
Do Aloe vera and Ageratum conyzoides enhance the anti-microbial activity of traditional medicinal soft soaps (Osedudu)?

PubMed

Moody, J O; Adebiyi, O A; Adeniyi, B A

2004-05-01

The Nigerian traditional soft soaps prepared using varied locally sourced raw materials such as cocoa pod ash (Theobroma cacao) palm kernel shaft ash (Elaies guineensis) have been evaluated for their physico-chemical properties and anti-microbial activities using standard pharmacopoeia protocols and an in-vitro agar diffusion bioassay method. The anti-microbial evaluation was done with and without incorporation of Aloe vera and Ageratum conyzoides extractives into the soap samples. Results showed that the physico-chemical properties of the soaps are dependent on the raw materials utilised. The incorporated medicinal plants used in this study, however, did not show any significant effect on the anti-microbial activities exhibited by the various soaps against the bacterial and fungal test organisms. Copyright 2004 Elsevier Ireland Ltd.
A Study of the Surface Structure of Polymorphic Graphene and Other Two-Dimensional Materials for Use in Novel Electronics and Organic Photovoltaics

NASA Astrophysics Data System (ADS)

Grady, Maxwell

For some time there has been interest in the fundamental physical properties of low- dimensional material systems. The discovery of graphene as a stable two-dimensional form of solid carbon lead to an exponential increase in research in two-dimensional and other re- duced dimensional systems. It is now known that there is a wide range of materials which are stable in two-dimensional form. These materials span a large configuration space of struc- tural, mechanical, and electronic properties, which results in the potential to create novel electronic devices from nano-scale heterostructures with exactly tailored device properties. Understanding the material properties at the nanoscale level requires specialized tools to probe materials with atomic precision. Here I present the growth and analysis of a novel graphene-ruthenium system which exhibits unique polymorphism in its surface structure, hereby referred to as polymorphic graphene. Scanning Tunneling Microscopy (STM) investigations of the polymorphic graphene surface reveal a periodically rippled structure with a vast array of domains, each exhibiting xvia unique moire period. The majority of moire domains found in this polymorphic graphene system are previously unreported in past studies of the structure of graphene on ruthenium. To better understand many of the structural properties of this system, characterization methods beyond those available at the UNH surface science lab are employed. Further investigation using Low Energy Electron Microscopy (LEEM) has been carried out at Sandia National Laboratory's Center for Integrated Nanotechnology and the Brookhaven National Laboratory Center for Functional Nanomaterials. To aid in analysis of the LEEM data, I have developed an open source software package to automate extraction of electron reflectivity curves from real space and reciprocal space data sets. This software has been used in the study of numerous other two-dimensional materials beyond graphene. When combined with computational modeling, the analysis of electron I(V) curves presents a method to quantify structural parameters in a material with angstrom level precision. While many materials studied in this thesis offer unique electronic properties, my work focuses primarily on their structural aspects, as well as the instrumentation required to characterize the structure with ultra high resolution.
Effect of incorporation of antioxidants on the chemical, rheological, and sensory properties of probiotic petit suisse cheese.

PubMed

Pereira, E P R; Cavalcanti, R N; Esmerino, E A; Silva, R; Guerreiro, L R M; Cunha, R L; Bolini, H M A; Meireles, M A; Faria, J A F; Cruz, A G

2016-03-01

This work investigated the effect of the addition of different antioxidants (ascorbic acid, glucose oxidase, cysteine, and jabuticaba extract) on the rheological and sensorial properties of the probiotic petit suisse cheese. Absence of influence of the antioxidants at the physico-chemical characteristics of the petit suisse cheese was observed. Overall, the petit suisse cheeses presented weak gel characteristics and behaved as pseudoplastic material, except for control. All treatments exhibited a thixotropic non-Newtonian behavior; however, higher hysteresis area was obtained for control sample, which indicates that antioxidants incorporated to petit suisse had a protective effect on the typical thixotropic behavior of the Quark gel. The commercial sample presented higher scores for all aspects by consumers, whereas the probiotic petit suisse samples presented opposite behavior. Projective mapping was able to generate a vocabulary where the sample containing jabuticaba skin extract obtained by supercritical extraction was characterized by the panelists as presenting grape flavor and purple color. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.
Novel mathematic models for quantitative transitivity of quality-markers in extraction process of the Buyanghuanwu decoction.

PubMed

Zhang, Yu-Tian; Xiao, Mei-Feng; Deng, Kai-Wen; Yang, Yan-Tao; Zhou, Yi-Qun; Zhou, Jin; He, Fu-Yuan; Liu, Wen-Long

2018-06-01

Nowadays, to research and formulate an efficiency extraction system for Chinese herbal medicine, scientists have always been facing a great challenge for quality management, so that the transitivity of Q-markers in quantitative analysis of TCM was proposed by Prof. Liu recently. In order to improve the quality of extraction from raw medicinal materials for clinical preparations, a series of integrated mathematic models for transitivity of Q-markers in quantitative analysis of TCM were established. Buyanghuanwu decoction (BYHWD) was a commonly TCMs prescription, which was used to prevent and treat the ischemic heart and brain diseases. In this paper, we selected BYHWD as an extraction experimental subject to study the quantitative transitivity of TCM. Based on theory of Fick's Rule and Noyes-Whitney equation, novel kinetic models were established for extraction of active components. Meanwhile, fitting out kinetic equations of extracted models and then calculating the inherent parameters in material piece and Q-marker quantitative transfer coefficients, which were considered as indexes to evaluate transitivity of Q-markers in quantitative analysis of the extraction process of BYHWD. HPLC was applied to screen and analyze the potential Q-markers in the extraction process. Fick's Rule and Noyes-Whitney equation were adopted for mathematically modeling extraction process. Kinetic parameters were fitted and calculated by the Statistical Program for Social Sciences 20.0 software. The transferable efficiency was described and evaluated by potential Q-markers transfer trajectory via transitivity availability AUC, extraction ratio P, and decomposition ratio D respectively. The Q-marker was identified with AUC, P, D. Astragaloside IV, laetrile, paeoniflorin, and ferulic acid were studied as potential Q-markers from BYHWD. The relative technologic parameters were presented by mathematic models, which could adequately illustrate the inherent properties of raw materials preparation and affection of Q-markers transitivity in equilibrium processing. AUC, P, D for potential Q-markers of AST-IV, laetrile, paeoniflorin, and FA were obtained, with the results of 289.9 mAu s, 46.24%, 22.35%; 1730 mAu s, 84.48%, 1.963%; 5600 mAu s, 70.22%, 0.4752%; 7810 mAu s, 24.29%, 4.235%, respectively. The results showed that the suitable Q-markers were laetrile and paeoniflorin in our study, which exhibited acceptable traceability and transitivity in the extraction process of TCMs. Therefore, these novel mathematic models might be developed as a new standard to control TCMs quality process from raw medicinal materials to product manufacturing. Copyright © 2018 Elsevier GmbH. All rights reserved.
Single fibre strength of cellulosic fibre extracted from "Belatlan roots" plant

NASA Astrophysics Data System (ADS)

M. Hanis. A., H.; Majid, M. S. Abdul; Ridzuan, M. J. M.; Fahmi, I.

2017-12-01

The tensile strength of a fibre extracted from "Belatlan Root" plant was investigated as potential reinforcement material in polymeric composites. Following retting process, the fibres were manually extracted from "Belatlan" root's plant. The fibres were treated with 5 % 10 %, 15 %, and 20 % sodium hydroxide (NaOH) wt. % concentration for 24 h. The single fibre tests were then performed in accordance with ASTM D3822-07 standard. The surfaces of the fibres prior and after the treatment were observed with a metallurgical Microscope MT8100 and the physical properties were recorded. Physically, in the post treatment, the fibre showed a decrease in diameter with increase in NaOH concentration The results from the mechanical testing indicates that samples subjected to 5 % NaOH treatment yielded the highest tensile strength and elastic modulus at 89.05 MPa ± 2.75 and 3.81 GPa ± 0.09 respectively compared to untreated fibres. This represents an increase of almost 72 % in tensile strength and 42 % for elastic modulus. The findings support the preliminary information for incorporating the "Belatlan Root" as possible reinforcing materials in composite structures.
Development of a pericardial acellular matrix biomaterial: biochemical and mechanical effects of cell extraction.

PubMed

Courtman, D W; Pereira, C A; Kashef, V; McComb, D; Lee, J M; Wilson, G J

1994-06-01

There is evidence to suggest that the cellular components of homografts and bioprosthetic xenografts may contribute to calcification or immunogenic reactions. A four-step detergent and enzymatic extraction process has been developed to remove cellular components from bovine pericardial tissue. The process results in an acellular matrix material consisting primarily of elastin, insoluble collagen, and tightly bound glycosaminoglycans. Light and electron microscopy confirmed that nearly all cellular constituents are removed without ultrastructural evidence of damage to fibrous components. Collagen denaturation temperatures remained unaltered. Biochemical analysis confirmed the retention of collagen and elastin and some differential extraction of glycosaminoglycans. Low strain rate fracture testing and high strain rate viscoelastic characterization showed that, with the exception of slightly increased stress relaxation, the mechanical properties of the fresh tissue were preserved in the pericardial acellular matrix. Crosslinking of the material in glutaraldehyde or poly(glycidyl ether) produced mechanical changes consistent with the same treatments of fresh tissue. The pericardial acellular matrix is a promising approach to the production of biomaterials for heart valve or cardiovascular patching applications.
Materials Knowledge Systems in Python - A Data Science Framework for Accelerated Development of Hierarchical Materials.

PubMed

Brough, David B; Wheeler, Daniel; Kalidindi, Surya R

2017-03-01

There is a critical need for customized analytics that take into account the stochastic nature of the internal structure of materials at multiple length scales in order to extract relevant and transferable knowledge. Data driven Process-Structure-Property (PSP) linkages provide systemic, modular and hierarchical framework for community driven curation of materials knowledge, and its transference to design and manufacturing experts. The Materials Knowledge Systems in Python project (PyMKS) is the first open source materials data science framework that can be used to create high value PSP linkages for hierarchical materials that can be leveraged by experts in materials science and engineering, manufacturing, machine learning and data science communities. This paper describes the main functions available from this repository, along with illustrations of how these can be accessed, utilized, and potentially further refined by the broader community of researchers.
Materials Knowledge Systems in Python - A Data Science Framework for Accelerated Development of Hierarchical Materials

PubMed Central

Brough, David B; Wheeler, Daniel; Kalidindi, Surya R.

2017-01-01

There is a critical need for customized analytics that take into account the stochastic nature of the internal structure of materials at multiple length scales in order to extract relevant and transferable knowledge. Data driven Process-Structure-Property (PSP) linkages provide systemic, modular and hierarchical framework for community driven curation of materials knowledge, and its transference to design and manufacturing experts. The Materials Knowledge Systems in Python project (PyMKS) is the first open source materials data science framework that can be used to create high value PSP linkages for hierarchical materials that can be leveraged by experts in materials science and engineering, manufacturing, machine learning and data science communities. This paper describes the main functions available from this repository, along with illustrations of how these can be accessed, utilized, and potentially further refined by the broader community of researchers. PMID:28690971
Method 1664, Revision A: n-hexane extractable material (HEM; oil and grease) and silica gel treated n-hexane extractable material (SGT-HEM; non-polar material) by extraction and gravimetry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

This method is for determination of n-hexane extractable material (HEM; oil and grease) and n-hexane extractable material that is not adsorbed by silica gel (SGT-HEM; non-polar material) in surface and saline waters and industrial and domestic aqueous wastes. Extractable materials that may be determined are relatively non-volatile hydrocarbons, vegetable oils, animal fats, waxes, soaps, greases, and related materials. This method is capable of measuring HEM and SGT-HEM in the range of 5 to 1000 mg/L, and may be extended to higher levels by analysis of a smaller sample volume collected separately.

Linking groundwater dissolved organic matter to sedimentary organic matter from a fluvio-lacustrine aquifer at Jianghan Plain, China by EEM-PARAFAC and hydrochemical analyses.

PubMed

Huang, Shuang-bing; Wang, Yan-xin; Ma, Teng; Tong, Lei; Wang, Yan-yan; Liu, Chang-rong; Zhao, Long

2015-10-01

The sources of dissolved organic matter (DOM) in groundwater are important to groundwater chemistry and quality. This study examined similarities in the nature of DOM and investigated the link between groundwater DOM (GDOM) and sedimentary organic matter (SOM) from a lacustrine-alluvial aquifer at Jianghan Plain. Sediment, groundwater and surface water samples were employed for SOM extraction, optical and/or chemical characterization, and subsequent fluorescence excitation-emission matrix (EEM) and parallel factor analyses (PARAFAC). Spectroscopic properties of bulk DOM pools showed that indices indicative of GDOM (e.g., biological source properties, humification level, aromaticity and molecule mobility) varied within the ranges of those of two extracted end-members of SOM: humic-like materials and microbe-associated materials. The coexistence of PARAFAC compositions and the sustaining internal relationship between GDOM and extracted SOM indicate a similar source. The results from principal component analyses with selected spectroscopic indices showed that GDOM exhibited a transition trend regarding its nature: from refractory high-humification DOM to intermediate humification DOM and then to microbe-associated DOM, with decreasing molecular weight. Correlations of spectroscopic indices with physicochemical parameters of the groundwater suggested that GDOM was released from SOM and was modified by microbial diagenetic processes. The current study demonstrated the associations of GDOM with SOM from a spectroscopic viewpoint and provided new evidence supporting SOM as the source of GDOM. Copyright © 2015 Elsevier B.V. All rights reserved.
Aging Wire Insulation Assessment by Phase Spectrum Examination of Ultrasonic Guided Waves

NASA Technical Reports Server (NTRS)

Anastasi, Robert F.; Madaras, Eric I.

2003-01-01

Wire integrity has become an area of concern to the aerospace community including DoD, NASA, FAA, and Industry. Over time and changing environmental conditions, wire insulation can become brittle and crack. The cracks expose the wire conductor and can be a source of equipment failure, short circuits, smoke, and fire. The technique of using the ultrasonic phase spectrum to extract material properties of the insulation is being examined. Ultrasonic guided waves will propagate in both the wire conductor and insulation. Assuming the condition of the conductor remains constant then the stiffness of the insulator can be determined by measuring the ultrasonic guided wave velocity. In the phase spectrum method the guided wave velocity is obtained by transforming the time base waveform to the frequency domain and taking the phase difference between two waveforms. The result can then be correlated with a database, derived by numerical model calculations, to extract material properties of the wire insulator. Initial laboratory tests were performed on a simple model consisting of a solid cylinder and then a solid cylinder with a polymer coating. For each sample the flexural mode waveform was identified. That waveform was then transformed to the frequency domain and a phase spectrum was calculated from a pair of waveforms. Experimental results on the simple model compared well to numerical calculations. Further tests were conducted on aircraft or mil-spec wire samples, to see if changes in wire insulation stiffness can be extracted using the phase spectrum technique.
Analysis of variability in additive manufactured open cell porous structures.

PubMed

Evans, Sam; Jones, Eric; Fox, Pete; Sutcliffe, Chris

2017-06-01

In this article, a novel method of analysing build consistency of additively manufactured open cell porous structures is presented. Conventionally, methods such as micro computed tomography or scanning electron microscopy imaging have been applied to the measurement of geometric properties of porous material; however, high costs and low speeds make them unsuitable for analysing high volumes of components. Recent advances in the image-based analysis of open cell structures have opened up the possibility of qualifying variation in manufacturing of porous material. Here, a photogrammetric method of measurement, employing image analysis to extract values for geometric properties, is used to investigate the variation between identically designed porous samples measuring changes in material thickness and pore size, both intra- and inter-build. Following the measurement of 125 samples, intra-build material thickness showed variation of ±12%, and pore size ±4% of the mean measured values across five builds. Inter-build material thickness and pore size showed mean ranges higher than those of intra-build, ±16% and ±6% of the mean material thickness and pore size, respectively. Acquired measurements created baseline variation values and demonstrated techniques suitable for tracking build deviation and inspecting additively manufactured porous structures to indicate unwanted process fluctuations.
Apparatus for hydrocarbon extraction

DOEpatents

Bohnert, George W.; Verhulst, Galen G.

2013-03-19

Systems and methods for hydrocarbon extraction from hydrocarbon-containing material. Such systems and methods relate to extracting hydrocarbon from hydrocarbon-containing material employing a non-aqueous extractant. Additionally, such systems and methods relate to recovering and reusing non-aqueous extractant employed for extracting hydrocarbon from hydrocarbon-containing material.
Evaluating belinjau (Gnetum gnemon L.) seed flour quality as a base for development of novel food products and food formulations.

PubMed

Bhat, Rajeev; binti Yahya, Nabilah

2014-08-01

Belinjau (Gnetum gnemon L.) seed flour was evaluated for nutritional composition, antioxidant activity and functional properties. Seed flour was found to be rich in protein (19.0g/100g), crude fibre (8.66g/100g), carbohydrates (64.1%), total dietary fibre (14.5%) and encompassed adequate amounts of essential amino acids, fatty acids and minerals. Antioxidant compounds such as total phenols (15.1 and 12.6mgGAE/100g), tannins (35.6 and 16.1mgCE/100g) and flavonoids (709 and 81.6mgCEQ/100g) were higher in ethanolic extracts over aqueous extracts, respectively. Inhibition of DPPH was high in ethanol extracts (48.9%) compared to aqueous extracts (19.7%), whereas aqueous extracts showed a higher FRAP value compared to ethanol extracts (0.98 and 0.61mmolFe(II)/100g, respectively). Results on functional properties revealed acceptable water and oil absorption capacities (5.51 and 1.98g/g, respectively), emulsion capacity and stability (15.3% and 6.90%, respectively), and foaming capacity (5.78%). FTIR spectral analysis showed seed flour to encompass major functional groups such as: amines, amides, amino acids, polysaccharides, carboxylic acids, esters and lipids. As belinjau seed flour possesses a rich nutraceutical value, it has high potential to be used as a basic raw material to develop new low cost nutritious functional foods. Copyright © 2014 Elsevier Ltd. All rights reserved.
Screening Togolese medicinal plants for few pharmacological properties

PubMed Central

Karou, Simplice D.; Tchacondo, Tchadjobo; Tchibozo, Micheline Agassounon Djikpo; Anani, Kokou; Ouattara, Lassina; Simpore, Jacques; de Souza, Comlan

2012-01-01

Background: Terminalia macroptera Guill. et Perr. (Combretaceae), Sida alba L. (Malvaceae), Prosopis africana Guill et Perr. Taub. (Mimosaceae), Bridelia ferruginea Benth. (Euphorbiaceae), and Vetiveria nigritana Stapf. (Asteraceae) are traditionally used in Togolese folk medicine to treat several diseases including microbial infections. Objective: This study aimed to investigate the antimicrobial, antioxidant, and hemolytic properties of the crude extracts of the above-mentioned plants. Materials and Methods: The antimicrobial and the antioxidant activities were assayed using the NCCLS microdilution method and the DPPH free radical scavenging, respectively. Human A+ red blood cells were used to perform the hemolytic assay. Phenolics were further quantified in the extracts using spectrophotometric methods. Results: Minimal inhibitory concentrations in the range of 230-1800 μg/ml were recorded in the NCCLS broth microdilution for both bacterial and fungal strains with methanol extracts. The DPPH radical scavenging assay yielded interesting antioxidant activities of the extracts of P. africana and T. macroptera (IC50 values of 0.003 ± 0.00 μg/ml and 0.05 ± 0.03 μg/ml, respectively). These activities were positively correlated with the total phenolic contents and negatively correlated with the proanthocyanidin content of the extracts. The hemolytic assay revealed that great hemolysis occurred with the methanol extracts of T. macroptera, S. longepedunculata, and B. ferruginea. Conclusion: These results support in part the use of the selected plants in the treatment of microbial infections. In addition, the plant showed an interesting antioxidant activity that could be useful in the management of oxidative stress. PMID:22518084
Concepts and Benefits of Lunar Core Drilling

NASA Technical Reports Server (NTRS)

McNamara, K. M.; Bogard, D. D.; Derkowski, B. J.; George, J. A.; Askew, R. S.; Lindsay, J. F.

2007-01-01

Understanding lunar material at depth is critical to nearly every aspect of NASA s Vision and Strategic Plan. As we consider sending human s back to the Moon for brief and extended periods, we will need to utilize lunar materials in construction, for resource extraction, and for radiation shielding and protection. In each case, we will be working with materials at some depth beneath the surface. Understanding the properties of that material is critical, thus the need for Lunar core drilling capability. Of course, the science benefit from returning core samples and operating down-hole autonomous experiments is a key element of Lunar missions as defined by NASA s Exploration Systems Architecture Study. Lunar missions will be targeted to answer specific questions concerning lunar science and re-sources.
Learning structure-property relationship in crystalline materials: A study of lanthanide-transition metal alloys

NASA Astrophysics Data System (ADS)

Pham, Tien-Lam; Nguyen, Nguyen-Duong; Nguyen, Van-Doan; Kino, Hiori; Miyake, Takashi; Dam, Hieu-Chi

2018-05-01

We have developed a descriptor named Orbital Field Matrix (OFM) for representing material structures in datasets of multi-element materials. The descriptor is based on the information regarding atomic valence shell electrons and their coordination. In this work, we develop an extension of OFM called OFM1. We have shown that these descriptors are highly applicable in predicting the physical properties of materials and in providing insights on the materials space by mapping into a low embedded dimensional space. Our experiments with transition metal/lanthanide metal alloys show that the local magnetic moments and formation energies can be accurately reproduced using simple nearest-neighbor regression, thus confirming the relevance of our descriptors. Using kernel ridge regressions, we could accurately reproduce formation energies and local magnetic moments calculated based on first-principles, with mean absolute errors of 0.03 μB and 0.10 eV/atom, respectively. We show that meaningful low-dimensional representations can be extracted from the original descriptor using descriptive learning algorithms. Intuitive prehension on the materials space, qualitative evaluation on the similarities in local structures or crystalline materials, and inference in the designing of new materials by element substitution can be performed effectively based on these low-dimensional representations.
Nanoscale determination of the mass enhancement factor in the lightly doped bulk insulator lead selenide.

PubMed

Zeljkovic, Ilija; Scipioni, Kane L; Walkup, Daniel; Okada, Yoshinori; Zhou, Wenwen; Sankar, R; Chang, Guoqing; Wang, Yung Jui; Lin, Hsin; Bansil, Arun; Chou, Fangcheng; Wang, Ziqiang; Madhavan, Vidya

2015-03-27

Bismuth chalcogenides and lead telluride/selenide alloys exhibit exceptional thermoelectric properties that could be harnessed for power generation and device applications. Since phonons play a significant role in achieving these desired properties, quantifying the interaction between phonons and electrons, which is encoded in the Eliashberg function of a material, is of immense importance. However, its precise extraction has in part been limited due to the lack of local experimental probes. Here we construct a method to directly extract the Eliashberg function using Landau level spectroscopy, and demonstrate its applicability to lightly doped thermoelectric bulk insulator PbSe. In addition to its high energy resolution only limited by thermal broadening, this novel experimental method could be used to detect variations in mass enhancement factor at the nanoscale level. This opens up a new pathway for investigating the local effects of doping and strain on the mass enhancement factor.
The physico-chemical properties of pangas catfish (Pangasius pangasius) skin gelatin

NASA Astrophysics Data System (ADS)

Pradarameswari, K. A.; Zaelani, K.; Waluyo, E.; Nurdiani, R.

2018-04-01

Gelatin can be used as emulsifier and stabilizer in food products. Until now, the most widely used raw materials for the production of gelatin industry are cow bone, cow skin and pig skin. Fish gelatin has been highlighted as a better alternative to replace mammals gelatin based on ethical and religious perspective. Fish gelatin was extracted from Pangas catfish skin to determine its physico-chemical properties. Different temperatures (45 °C, 50 °C, 55 °C) were employed during gelatin extraction. Higher temperature increased the yield and fat contents of Pangas catfish skin gelatin. In contrary, higher water, protein, ash contents were observed during lower temperature. Temperature significantly (p < 0.05) affected the gel strength, viscosity, melting point, and gelling point of fish skin gelatin. Based on the FTIR spectrum catfish skin gelatin functional groups can be identified as N-H, O-H, C = H, C-O and C-H.
Apparatus and methods for hydrocarbon extraction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bohnert, George W.; Verhulst, Galen G.

Systems and methods for hydrocarbon extraction from hydrocarbon-containing material. Such systems and methods relate to extracting hydrocarbon from hydrocarbon-containing material employing a non-aqueous extractant. Additionally, such systems and methods relate to recovering and reusing non-aqueous extractant employed for extracting hydrocarbon from hydrocarbon-containing material.
The Pharmacological Activity of Extracts of Cotton Dust

PubMed Central

Davenport, Anne; Paton, W. D. M.

1962-01-01

Aqueous extracts prepared from dust collected in the card-rooms of several cotton mills have been prepared and found to contain activity which contracts the smooth muscle of guinea-pig ileum, guinea-pig trachea, rat stomach strip, and rat duodenum. The extracts contained an unknown contractor substance which was dialysable, resistant to boiling for one hour, and not destroyed by the action of proteolytic enzymes. They also contained a small amount of 5-hydroxytryptamine. One of the dust samples also contained histamine, but it could not be detected in the other samples, one of which was known to possess bronchoconstrictor properties in man. The particulate material, even after repeated washing, was found to have some stimulant action on guinea-pig ileum. There was no evidence for the release of histamine by the extracts in either cats or guinea-pigs, although a very small amount was released in rats. Jute dust is much less active than cotton dust, and the activity differs qualitatively. Cotton dust extracts were found to have pyrogenic activity but it is unlikely that pyrogens were responsible for the smooth-muscle contractor properties. Experiments with whole animals suggest that although smooth-muscle contracting substances were present in the extracts, it is possible that the symptoms of byssinosis are caused by the release of some other active bronchoconstrictor substance in the tissues. The mechanism of the release is not known; it may be caused by a soluble principle in the extract or due to the presence of particulate matter in the dust. Images PMID:13883719
Potential High-Temperature Shape-Memory-Alloy Actuator Material Identified

NASA Technical Reports Server (NTRS)

Noebe, Ronald D.; Gaydosh, Darrell J.; Biles, Tiffany A.; Garg, Anita

2005-01-01

Shape-memory alloys are unique "smart materials" that can be used in a wide variety of adaptive or "intelligent" components. Because of a martensitic solid-state phase transformation in these materials, they can display rather unusual mechanical properties including shape-memory behavior. This phenomenon occurs when the material is deformed at low temperatures (below the martensite finish temperature, Mf) and then heated through the martensite-to-austenite phase transformation. As the material is heated to the austenite finish temperature Af, it is able to recover its predeformed shape. If a bias is applied to the material as it tries to recover its original shape, work can be extracted from the shape-memory alloy as it transforms. Therefore, shape-memory alloys are being considered for compact solid-state actuation devices to replace hydraulic, pneumatic, or motor-driven systems.
IR and Raman studies of oil and seedcake extracts from natural and genetically modified flax seeds

NASA Astrophysics Data System (ADS)

Żuk, M.; Dymińska, L.; Kulma, A.; Boba, A.; Prescha, A.; Szopa, J.; Mączka, M.; Zając, A.; Szołtysek, K.; Hanuza, J.

2011-03-01

Flax plant of the third generation (F3) overexpressing key genes of flavonoid pathway cultivated in field in 2008 season was used as the plant material throughout this study. The biochemical properties of seed, oil and seedcake extracts from natural and transgenic flax plants were compared. Overproduction of flavonoids (kaempferol), phenolic acids (coumaric, ferulic/synapic) and lignan-secoisolariciresinol diglucoside (SDG) in oil and extracts from transgenic seeds has been revealed providing a valuable source of these compounds for biotechnological application. The changes in fatty acids composition and increase in their stability against oxidation along three plant generations were also detected. The analysis of oil and seedcake extracts was performed using Raman and IR spectroscopy. The wavenumbers and integral intensities of Raman and IR bands were used to identify the components of phenylpropanoid pathway in oil and seedcake extracts from control and transgenic flax seeds. The spectroscopic data were compared to those obtained from biochemical analysis.
Synthesis of molecularly imprinted polymers using acrylamide-β-cyclodextrin as a cofunctional monomer for the specific capture of tea saponins from the defatted cake extract of Camellia oleifera.

PubMed

Guo, Huiqin; Xiong, Jingjing; Ma, Wentian; Wu, Minghuo; Yan, Liushui; Li, Kexin; Liu, Yu

2016-11-01

Molecularly imprinted polymers were synthesized using mixed tea saponins as a template and acrylamide-β-cyclodextrin as a cofunctional monomer for the specific binding and purification of tea saponins from the defatted cake extract of Camellia oleifera. The adsorption properties of the prepared polymers were systematically evaluated including adsorption kinetics, adsorption isotherms, and selective recognition characteristics. It showed that the adsorption kinetics followed the pseudo first-order kinetic model (R 2 = 0.995) with an equilibrium time of 3 h, adsorption isotherm data fitted well with the Langmuir-Freundlich model (R 2 = 0.984) with an adsorption capacity of 14.23 mg/g. The relative selectivity coefficient (k´) in the presence of the analogues glycyrrhizic acid and glycyrrhetinic acid were 1.16 and 17.21, respectively. The performance of the molecularly imprinted polymers as solid-phase extraction materials was investigated and the results indicated that using acrylamide-β-cyclodextrin as a cofunctional monomer improved both the adsorption capacity and active sites stability of the imprinted polymers. The solid-phase extraction using the polymers as packing materials was subsequently applied for the separation of tea saponins in raw C. oleifera press extract, and targets were obtained with a purity reaching 89%. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Deep Eutectic Solvents Modified Molecular Imprinted Polymers for Optimized Purification of Chlorogenic Acid from Honeysuckle.

PubMed

Li, Guizhen; Wang, Wei; Wang, Qian; Zhu, Tao

2016-02-01

Deep eutectic solvents (DES) were synthesized with choline chloride (ChCl), and DES modified molecular imprinted polymers (DES-MIPs), DES modified non-imprinted polymers (DES-NIPs, without template), MIPs and NIPs were prepared in an identical procedure. Fourier transform infrared spectrometer (FT-IR) and field emission scanning electron microscopy (FE-SEM) were used to characterize the obtained polymers. Rebinding experiment and solid-phase extraction (SPE) were used to prove the high selectivity adsorption properties of the polymers. Box-Behnken design (BBD) with three factors was used to optimize the extraction condition of chlorogenic acid (CA) from honeysuckles. The optimum extraction conditions were found to be ultrasonic time optimized (20 min), the volume fraction of ethanol (60%) and ratio of liquid to material (15 mL g(-1)). Under these conditions, the mean extraction yield of CA was 12.57 mg g(-1), which was in good agreement with the predicted BBD model value. Purification of hawthorn extract was achieved by SPE process, and SPE recoveries of CA were 72.56, 64.79, 69.34 and 60.08% by DES-MIPs, DES-NIPs, MIPs and NIPs, respectively. The results showed DES-MIPs had potential for promising functional adsorption material for the purification of bioactive compounds. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
[Determination of estrogen residues in drinking water by on-line solid phase extraction based on sol-gel technique coupled with high performance liquid chromatography].

PubMed

Li, Longfei; Su, Min; Shi, Xiaolei; Wang, Yana; Wang, Minmin; He, Jinxing

2014-02-01

A method for the determination of diethylstilbestrol (DES), hexestrol (HEX) and dienestrol (DS) residues in drinking water was established by on-line solid phase extraction (SPE) coupled with high performance liquid chromatography (HPLC). The material synthesized on the base of sol-gel technology was employed as adsorbent. This material was prepared using 3-aminopropyltriethoxysilane (APTES) as the functional monomer, tetraethoxysilane (TEOS) as the crosslinking agent, and acetic acid as the initiator. The synthesized adsorbent showed outstanding property for the estrogen extraction. The estrogen can be caught effectively from water samples and the extraction can be achieved rapidly. Some important parameters, such as pH of sample solution, eluent solvents, loading flow rate, which might influence extraction efficiency, were optimized. The results indicated that the limit of detection (S/N = 3) of the developed method could reach 0.07-0.13 microg/L under the conditions of pH 7.0 of sample solution, methanol and 1% (v/v) acetic acid aqueous solution as the eluent solvent and the loading flow rate of 2 mL/min. The recoveries of the three estrogens from the water samples at three spiked levels ranged from 82.31% to 99.43% with RSD of 1.61%-7.15%. The method was simple, rapid, and suitable to detect the trace residues of estrogens in drinking water.
Palmyra palm (Borassus aethiopum Mart.) fruits: novel raw materials for the pectin industry.

PubMed

Assoi, Sylvie; Konan, Koffi; Agbo, Georges N; Dodo, Hortense; Holser, Ron; Wicker, Louise

2017-05-01

Preventing post-harvest waste of Palmyra palm (Borassus aethiopum Mart.) fruits is possible by recovery of pectin as a value-added ingredient. Extraction conditions on yield and functionality of Palmyra palm pectin was determined at different temperatures and pH values with 30 min extraction time. Palmyra palm fruits contain more than 650 g kg -1 galacturonic acid and produce soft gels with sucrose in acidic media despite a high degree of acetylation (∼5%). Mechanical deformation of pectin gel was similar when extracted at pH 2.5 and 70 °C or under natural pH at room temperature or 70 °C. Pectins isolated at pH 7 exhibited comparable gel softness (G'/G″) with commercial pectin. Palm pectins also showed emulsifying activity greater than 50%, attributed to high protein content of 8 g 100 g -1 . For pectins extracted at pH near 5.2-5.5, molar mass ranged from 3.00 to 3.38 × 10 5 g mol -1 ; intrinsic viscosity ranged from 218 to 297 mL g -1 ; arabinose was the main neutral sugar; ζ-potential ranged from -23 to -25 mV. Palm fruit offers an inexpensive raw material to extract pectin in environmentally friendly and economical way and yield a pectin with unique gelling, viscosifying and emulsifying properties. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.
Biochemical characterization and anti-inflammatory properties of an isothiocyanate-enriched moringa (Moringa oleifera) seed extract.

PubMed

Jaja-Chimedza, Asha; Graf, Brittany L; Simmler, Charlotte; Kim, Youjin; Kuhn, Peter; Pauli, Guido F; Raskin, Ilya

2017-01-01

Moringa oleifera Lam. is a tropical plant, used for centuries as food and traditional medicine. The aim of this study was to develop, validate and biochemically characterize an isothiocyanate-enriched moringa seed extract (MSE), and to compare the anti-inflammatory effects of MSE-containing moringa isothiocyanate-1 (MIC-1) with a curcuminoid-enriched turmeric extract (CTE), and a material further enriched in its primary phytochemical, curcumin (curcumin-enriched material; CEM). MSE was prepared by incubating ground moringa seeds with water to allow myrosinase-catalyzed enzymatic formation of bioactive MIC-1, the predominant isothiocyanate in moringa seeds. Optimization of the extraction process yielded an extract of 38.9% MIC-1. Phytochemical analysis of MSE revealed the presence of acetylated isothiocyanates, phenolic glycosides unique to moringa, flavonoids, fats and fatty acids, proteins and carbohydrates. MSE showed a reduction in the carrageenan-induced rat paw edema (33% at 500 mg/kg MIC-1) comparable to aspirin (27% at 300 mg/kg), whereas CTE did not have any significant effect. In vitro, MIC-1 at 1 μM significantly reduced the production of nitric oxide (NO) and at 5 μM, the gene expression of LPS-inducible nitric oxide synthase (iNOS) and interleukins 1β and 6 (IL-1β and IL-6), whereas CEM did not show any significant activity at all concentrations tested. MIC-1 (10μM) was also more effective at upregulating the nuclear factor (erythroid-derived 2)-like 2 (Nrf2) target genes NAD(P)H:quinone oxidoreductase 1 (NQO1), glutathione S-transferase pi 1 (GSTP1), and heme oxygenase 1 (HO1) than the CEM. Thus, in contrast to CTE and CEM, MSE and its major isothiocyanate MIC-1 displayed strong anti-inflammatory and antioxidant properties in vivo and in vitro, making them promising botanical leads for the mitigation of inflammatory-mediated chronic disorders.
Biochemical characterization and anti-inflammatory properties of an isothiocyanate-enriched moringa (Moringa oleifera) seed extract

PubMed Central

Simmler, Charlotte; Kim, Youjin; Kuhn, Peter; Pauli, Guido F.; Raskin, Ilya

2017-01-01

Moringa oleifera Lam. is a tropical plant, used for centuries as food and traditional medicine. The aim of this study was to develop, validate and biochemically characterize an isothiocyanate-enriched moringa seed extract (MSE), and to compare the anti-inflammatory effects of MSE-containing moringa isothiocyanate-1 (MIC-1) with a curcuminoid-enriched turmeric extract (CTE), and a material further enriched in its primary phytochemical, curcumin (curcumin-enriched material; CEM). MSE was prepared by incubating ground moringa seeds with water to allow myrosinase-catalyzed enzymatic formation of bioactive MIC-1, the predominant isothiocyanate in moringa seeds. Optimization of the extraction process yielded an extract of 38.9% MIC-1. Phytochemical analysis of MSE revealed the presence of acetylated isothiocyanates, phenolic glycosides unique to moringa, flavonoids, fats and fatty acids, proteins and carbohydrates. MSE showed a reduction in the carrageenan-induced rat paw edema (33% at 500 mg/kg MIC-1) comparable to aspirin (27% at 300 mg/kg), whereas CTE did not have any significant effect. In vitro, MIC-1 at 1 μM significantly reduced the production of nitric oxide (NO) and at 5 μM, the gene expression of LPS-inducible nitric oxide synthase (iNOS) and interleukins 1β and 6 (IL-1β and IL-6), whereas CEM did not show any significant activity at all concentrations tested. MIC-1 (10μM) was also more effective at upregulating the nuclear factor (erythroid-derived 2)-like 2 (Nrf2) target genes NAD(P)H:quinone oxidoreductase 1 (NQO1), glutathione S-transferase pi 1 (GSTP1), and heme oxygenase 1 (HO1) than the CEM. Thus, in contrast to CTE and CEM, MSE and its major isothiocyanate MIC-1 displayed strong anti-inflammatory and antioxidant properties in vivo and in vitro, making them promising botanical leads for the mitigation of inflammatory-mediated chronic disorders. PMID:28792522

Local X-ray Computed Tomography Imaging for Mineralogical and Pore Characterization

NASA Astrophysics Data System (ADS)

Mills, G.; Willson, C. S.

2015-12-01

Sample size, material properties and image resolution are all tradeoffs that must be considered when imaging porous media samples with X-ray computed tomography. In many natural and engineered samples, pore and throat sizes span several orders of magnitude and are often correlated with the material composition. Local tomography is a nondestructive technique that images a subvolume, within a larger specimen, at high resolution and uses low-resolution tomography data from the larger specimen to reduce reconstruction error. The high-resolution, subvolume data can be used to extract important fine-scale properties but, due to the additional noise associated with the truncated dataset, it makes segmentation of different materials and mineral phases a challenge. The low-resolution data of a larger specimen is typically of much higher-quality making material characterization much easier. In addition, the imaging of a larger domain, allows for mm-scale bulk properties and heterogeneities to be determined. In this research, a 7 mm diameter and ~15 mm in length sandstone core was scanned twice. The first scan was performed to cover the entire diameter and length of the specimen at an image voxel resolution of 4.1 μm. The second scan was performed on a subvolume, ~1.3 mm in length and ~2.1 mm in diameter, at an image voxel resolution of 1.08 μm. After image processing and segmentation, the pore network structure and mineralogical features were extracted from the low-resolution dataset. Due to the noise in the truncated high-resolution dataset, several image processing approaches were applied prior to image segmentation and extraction of the pore network structure and mineralogy. Results from the different truncated tomography segmented data sets are compared to each other to evaluate the potential of each approach in identifying the different solid phases from the original 16 bit data set. The truncated tomography segmented data sets were also compared to the whole-core tomography segmented data set in two ways: (1) assessment of the porosity and pore size distribution at different scales; and (2) comparison of the mineralogical composition and distribution. Finally, registration of the two datasets will be used to show how the pore structure and mineralogy details at the two scales can be used to supplement each other.
Chitosan-based microcapsules containing grapefruit seed extract grafted onto cellulose fibers by a non-toxic procedure.

PubMed

Alonso, Diana; Gimeno, Miquel; Sepúlveda-Sánchez, José D; Shirai, Keiko

2010-04-19

A novel non-toxic procedure is described for the grafting of chitosan-based microcapsules containing grapefruit seed oil extract onto cellulose. The cellulose was previously UV-irradiated and then functionalized from an aqueous emulsion of the chitosan with the essential oil. The novel materials are readily attained with durable fragrance and enhanced antimicrobial properties. The incorporation of chitosan as determined from the elemental analyses data was 16.08+/-0.29 mg/g of sample. Scanning electron microscopy (SEM) and gas chromatography-mass spectroscopy (GC-MS) provided further evidence for the successful attachment of chitosan microcapsules containing the essential oil to the treated cellulose fibers. The materials thus produced displayed 100% inhibition of Escherichia coli and Staphylococcus epidermidis up to 48 h of incubation. Inhibition of bacteria by the essential oil was also evaluated at several concentrations. Copyright (c) 2010 Elsevier Ltd. All rights reserved.
An inorganic boronate affinity in-needle monolithic device for specific capture of cis-diol containing compounds.

PubMed

Jin, Shanxia; Zhang, Wei; Yang, Qin; Dai, Lili; Zhou, Ping

2018-02-01

In this work, inorganic boronate affinity monolith was prepared by in situ synthesis in 0.33mm i.d. stainless steel needle through sol-gel process using tetraethoxysilane and tetrabutyl orthotitanate as the co-precursors. The morphology, structure and composition of the monolith were characterized. In contrast to conventional boronate affinity materials, inorganic boric acid was used as affinity ligand. Different compounds were used for the evaluation of the boronate affinity of this inorganic monolithic material. The monolith exhibited good selectivity towards cis-diol containing compounds. Recovery of greater than 90% was achieved for in-needle extraction of catechol under neutral conditions. Owing to the hydrophilic property of the monolith, the procedure of affinity chromatography could be performed in aqueous solution. This monolithic in-needle device will be useful for boronate affinity extraction of small-volume samples. Copyright © 2017 Elsevier B.V. All rights reserved.
Modelling and simulation of a moving interface problem: freeze drying of black tea extract

NASA Astrophysics Data System (ADS)

Aydin, Ebubekir Sıddık; Yucel, Ozgun; Sadikoglu, Hasan

2017-06-01

The moving interface separates the material that is subjected to the freeze drying process as dried and frozen. Therefore, the accurate modeling the moving interface reduces the process time and energy consumption by improving the heat and mass transfer predictions during the process. To describe the dynamic behavior of the drying stages of the freeze-drying, a case study of brewed black tea extract in storage trays including moving interface was modeled that the heat and mass transfer equations were solved using orthogonal collocation method based on Jacobian polynomial approximation. Transport parameters and physical properties describing the freeze drying of black tea extract were evaluated by fitting the experimental data using Levenberg-Marquardt algorithm. Experimental results showed good agreement with the theoretical predictions.
Algorithm based on regional separation for automatic grain boundary extraction using improved mean shift method

NASA Astrophysics Data System (ADS)

Zhenying, Xu; Jiandong, Zhu; Qi, Zhang; Yamba, Philip

2018-06-01

Metallographic microscopy shows that the vast majority of metal materials are composed of many small grains; the grain size of a metal is important for determining the tensile strength, toughness, plasticity, and other mechanical properties. In order to quantitatively evaluate grain size in metals, grain boundaries must be identified in metallographic images. Based on the phenomenon of grain boundary blurring or disconnection in metallographic images, this study develops an algorithm based on regional separation for automatically extracting grain boundaries by an improved mean shift method. Experimental observation shows that the grain boundaries obtained by the proposed algorithm are highly complete and accurate. This research has practical value because the proposed algorithm is suitable for grain boundary extraction from most metallographic images.
An X-band waveguide measurement technique for the accurate characterization of materials with low dielectric loss permittivity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Allen, Kenneth W., E-mail: kenneth.allen@gtri.gatech.edu; Scott, Mark M.; Reid, David R.

In this work, we present a new X-band waveguide (WR90) measurement method that permits the broadband characterization of the complex permittivity for low dielectric loss tangent material specimens with improved accuracy. An electrically long polypropylene specimen that partially fills the cross-section is inserted into the waveguide and the transmitted scattering parameter (S{sub 21}) is measured. The extraction method relies on computational electromagnetic simulations, coupled with a genetic algorithm, to match the experimental S{sub 21} measurement. The sensitivity of the technique to sample length was explored by simulating specimen lengths from 2.54 to 15.24 cm, in 2.54 cm increments. Analysis ofmore » our simulated data predicts the technique will have the sensitivity to measure loss tangent values on the order of 10{sup −3} for materials such as polymers with relatively low real permittivity values. The ability to accurately characterize low-loss dielectric material specimens of polypropylene is demonstrated experimentally. The method was validated by excellent agreement with a free-space focused-beam system measurement of a polypropylene sheet. This technique provides the material measurement community with the ability to accurately extract material properties of low-loss material specimen over the entire X-band range. This technique could easily be extended to other frequency bands.« less
The efficiency of solvent extraction of mutagenic compounds in particulates exhausted from a small diesel engine.

PubMed

Tahara, I; Kinouchi, T; Kataoka, K; Ohnishi, Y

1994-06-01

Organic materials were extracted from particulates exhausted from a small diesel engine (displacement 269 ml) by the ultrasonic extraction method with three different solvent systems, methanol, dichloromethane and a 4:1 (v:v) mixture of benzene and ethanol. These solvent-extracted materials were tested for mutagenic activity by the Ames Salmonella/microsome assay system using Salmonella typhimurium strains TA98, TA100, TA98NR and TA98/1,8-DNP6. The concentrations of 1-nitropyrene (1-NP) and 1,6-dinitropyrene (1,6-diNP) in these extracted materials were also measured after nitroreduction by high pressure liquid chromatography. The methanol-extracted and benzene-ethanol-extracted materials showed the lowest and the highest mutagenic activity, respectively. The methanol-extracted, dichloromethane-extracted and benzene-ethanol-extracted materials induced 260, 1,570 and 3,240 His+ revertants per plate per mg of extracted materials, respectively, from strain TA98 in the absence of S9 mix. These materials showed decreased mutagenicity for strains TA98NR and TA98/1,8-DNP6, indicating that the particulates in the diesel engine exhaust contained 1-NP and diNPs. Actually, the amount of 1-NP and 1,6-diNP in the methanol-extracted, dichloromethane-extracted and benzene-ethanol-extracted materials were 17.0 and 0.03 ng, 37.5 and 0.97 ng, and 71.3 and 1.03 ng per mg of extracted materials, respectively, accounting for 11.9 and 3.2%, 4.4 and 17.3%, and 4.0 and 8.9%, respectively, of the total mutagenicity of the extracted materials. From these results it is concluded that a mixture of benzene-ethanol (4:1, v/v) is the most suitable solvent for extraction of organic matter containing nitrated polycyclic aromatic hydrocarbons such as NPs from particulates in diesel engine exhaust.
Extractables characterization for five materials of construction representative of packaging systems used for parenteral and ophthalmic drug products.

PubMed

Jenke, Dennis; Castner, James; Egert, Thomas; Feinberg, Tom; Hendricker, Alan; Houston, Christopher; Hunt, Desmond G; Lynch, Michael; Shaw, Arthur; Nicholas, Kumudini; Norwood, Daniel L; Paskiet, Diane; Ruberto, Michael; Smith, Edward J; Holcomb, Frank

2013-01-01

Polymeric and elastomeric materials are commonly encountered in medical devices and packaging systems used to manufacture, store, deliver, and/or administer drug products. Characterizing extractables from such materials is a necessary step in establishing their suitability for use in these applications. In this study, five individual materials representative of polymers and elastomers commonly used in packaging systems and devices were extracted under conditions and with solvents that are relevant to parenteral and ophthalmic drug products (PODPs). Extraction methods included elevated temperature sealed vessel extraction, sonication, refluxing, and Soxhlet extraction. Extraction solvents included a low-pH (pH = 2.5) salt mixture, a high-pH (pH = 9.5) phosphate buffer, a 1/1 isopropanol/water mixture, isopropanol, and hexane. The resulting extracts were chemically characterized via spectroscopic and chromatographic means to establish the metal/trace element and organic extractables profiles. Additionally, the test articles themselves were tested for volatile organic substances. The results of this testing established the extractables profiles of the test articles, which are reported herein. Trends in the extractables, and their estimated concentrations, as a function of the extraction and testing methodologies are considered in the context of the use of the test article in medical applications and with respect to establishing best demonstrated practices for extractables profiling of materials used in PODP-related packaging systems and devices. Plastic and rubber materials are commonly encountered in medical devices and packaging/delivery systems for drug products. Characterizing the extractables from these materials is an important part of determining that they are suitable for use. In this study, five materials representative of plastics and rubbers used in packaging and medical devices were extracted by several means, and the extracts were analytically characterized to establish each material's profile of extracted organic compounds and trace element/metals. This information was utilized to make generalizations about the appropriateness of the test methods and the appropriate use of the test materials.
Extraction of Peace River bitumen using supercritical ethane

NASA Astrophysics Data System (ADS)

Rose, Jeffrey Lawrence

2000-10-01

As the supply of conventional crude oil continues to decline, petroleum companies are looking for alternative hydrocarbon sources. The vast reserves of heavy oil and bitumen located in northern Alberta are among the alternatives. The challenge facing engineers is to develop a process for recovering this oil which is economic, efficient and environmentally acceptable. Supercritical fluid extraction is one method being investigated which could potentially meet all of these criteria. In this study, Peace River bitumen was extracted using supercritical ethane. The bitumen was mixed with sand and packed into a semi-batch extractor. Ethane contacted the bitumen/sand mixture and the fraction of the bitumen soluble in the ethane was removed and subsequently collected in a two phase separator. The flow of ethane was such that the experiments were governed by equilibrium and not mass transfer. Experimental temperatures and pressures were varied in order to observe the effect of these parameters on the mass and composition of the extracted material. The extraction yields increased as the temperature decreased and pressure increased. Samples were collected at various time intervals to measure changes in the properties of the extracted bitumen over the duration of the process. As the extraction proceeded, the samples became heavier and more viscous. The bitumen feed was characterised and the experimental data was then modelled using the Peng-Robinson equation of state. The characterisation process involved the distillation of the bitumen into five fractions. The distillation curve and density of each fraction was measured and this data was used in conjunction with correlations to determine the critical properties of the bitumen. Interaction parameters in the equation of state were then optimised until the predicted composition of extracted bitumen matched the experimental results.
Anti-microbial Efficacy of Soursop Leaf Extract (Annona muricata) on Oral Pathogens: An In-vitro Study

PubMed Central

Rajesh, Gururagavendra; Shenoy, Ramya; Rao, Ashwini

2016-01-01

Introduction Annona muricata also called as Soursop is a, flowering evergreen tree native to Mexico, Cuba, Central America and parts of India. The miracle tree as it is widely known as a natural cancer killer that is 10,000 times stronger than chemotherapy. Based on these miraculous claims, the leaves of these plants were used as an extract at varying concentrations as an antibacterial agent against oral pathogens. Aim The aim of the study was to assess antimicrobial efficacy of Soursop leaf extarct (Annona muricata) on Streptococcus mutans, Streptococcus mitis, Porphyromonas gingivalis, Prevotella intermedia and Candida albicans using disc diffusion method. Materials and Methods Extracts of Annona muricata leaves of concentrations of 1%, 5%, 10%, 15% and 20% were prepared. The anti-microbial efficacy was evaluated using disc diffusion method against Streptococcus mutans, Streptococcus mitis, Porphyromonas gingivalis, Prevotella intermedia and Candida albicans on agar plates. Results All concentrations of extracts were effective on the microbiota except for the P. Intermedia. The Soursop extract was highly effective on Candida species, with all concentrations exhibiting bactericidal and fungicidal property. The extracts at different concentration were effective when compared to the gold standard controls and the effect was statistically significant (p<0.05). Data obtained was analysed using one way analysis of variance (ANOVA) and Tukey’s post-hoc test. Conclusion The Soursop extracts were efficient for all test organisms expect P. intermedia. The present study demonstrated the in-vitro efficacy of Soursop was highest against S. mutans followed by C. albicans and least on P. intermedia. Hence, this study proves to an extent that the Soursop extract when used against oral microbiota has sufficient anti-microbial and fungicidal property. PMID:28050493
Development of an active food packaging system with antioxidant properties based on green tea extract.

PubMed

Carrizo, Daniel; Gullo, Giuseppe; Bosetti, Osvaldo; Nerín, Cristina

2014-01-01

A formula including green tea extract (GTE) was developed as an active food packaging material. This formula was moulded to obtain an independent component/device with antioxidant properties that could be easily coupled to industrial degassing valves for food packaging in special cases. GTE components (i.e., gallic acid, catechins and caffeine) were identified and quantified by HPLC-UV and UPLC-MS and migration/diffusion studies were carried out. Antioxidant properties of the formula alone and formula-valve were measured with static and dynamic methods. The results showed that the antioxidant capacity (scavenging of free radicals) of the new GTE formula was 40% higher than the non-active system (blank). This antioxidant activity increased in parallel with the GTE concentration. The functional properties of the industrial target valve (e.g., flexibility) were studied for different mixtures of GTE, and good results were found with 17% (w/w) of GTE. This new active formula can be an important addition for active packaging applications in the food packaging industry, with oxidative species-scavenging capacity, thus improving the safety and quality for the consumer and extending the shelf-life of the packaged food.
Extraction, composition, and functional properties of dried alfalfa (Medicago sativa L.) leaf protein.

PubMed

Hojilla-Evangelista, Mila P; Selling, Gordon W; Hatfield, Ronald; Digman, Matthew

2017-02-01

Alfalfa is considered a potential feedstock for biofuels; co-products with value-added uses would enhance process viability. This work evaluated dried alfalfa leaves for protein production and describes the functional properties of the protein. Dried alfalfa leaves contained 260 g kg -1 dry basis (DB) crude protein, with albumins being the major fraction (260 g kg -1 of total protein). Alkali solubilization for 2 h at 50 °C, acid precipitation, dialysis, and freeze-drying produced a protein concentrate (600 g kg -1 DB crude protein). Alfalfa leaf protein concentrate showed moderate solubility (maximum 500 g kg -1 soluble protein from pH 5.5 to 10), excellent emulsifying properties (activity 158-219 m 2 g -1 protein, stability 17-49 min) and minimal loss of solubility during heating at pH ≥ 7.0. It is technically feasible to extract protein with desirable emulsifying and heat stability properties from dried alfalfa leaves; however, the dried form may not be a practical starting material for protein production, given the difficulty of achieving high yields and high-purity protein product. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.
The surface reactivity of chalk (biogenic calcite) with hydrophilic and hydrophobic functional groups

NASA Astrophysics Data System (ADS)

Okhrimenko, D. V.; Dalby, K. N.; Skovbjerg, L. L.; Bovet, N.; Christensen, J. H.; Stipp, S. L. S.

2014-03-01

The surface properties of calcium carbonate minerals play an important role in a number of industrial and biological processes. Properties such as wettability and adsorption control liquid-solid interface behaviour and thus have a strong influence on processes such as biomineralisation, remediation of aquifers and oil recovery. We investigated how two model molecules of different polarity, namely water and ethanol, interact with reservoir and outcrop chalk samples and we compared their behaviour with that of pure, inorganically precipitated calcite. Thermodynamic quantities, such as the work of wetting, surface energy and isosteric adsorption enthalpy, were determined from vapour adsorption isotherms. The chalks were studied fresh and after extraction of organic residues that were originally present in these samples. The work of wetting correlates with the amount of organic matter present in the chalk samples but we observed a fundamental difference between the adsorption properties of chalk and pure, inorganically precipitated calcite toward the less polar, ethanol molecule. Further analysis of the chemical composition of the organic matter extracted from the chalk samples was made by gas chromatography (GC-MS). Monitoring surface composition by X-ray photoelectron spectroscopy (XPS) before and after extraction of the organic material, and with atomic force microscopy (AFM), showed that nanometer sized clay crystals observed on the chalk particle surfaces could be an important part of the reason for the differences. Removal of the extractable portion of the hydrocarbons liberates adsorption sites that have different wetting properties than the rest of the chalk and these have an energy distribution that is similar to clays. Thus, the results exemplify the complexity of biogenic calcite adsorption behaviour and demonstrate that chalk wetting in drinking water aquifers as well as oil reservoirs is controlled partly by the nanoparticles of clay that have grown on the chalk surfaces and partly by adsorbed organic material. GS < GS after extraction < WS < WS after extraction < Ålborg after extraction ⩽ Ålborg. The increase of spreading work for WS chalk for ethanol is 21 mN/m and for water is 26 mN/m, a ratio of 21/26 = 0.81. The increase of spreading work for GS chalk for ethanol and water are 36 and 42 mN/m, a ratio of 36/42 = 0.86. The similarity between these ratios leads us to conclude, that the surface that was produced by extraction of the organic material is quite similar for these two samples.The total surface energy increase, after the extraction of organics, for GS and WS was 67 and 49 mJ/m2. Further separation of surface energy into polar and dispersive parts showed that, for both samples, removing organic matter by extraction preferably increases the dispersive component of the surface energy. The contribution from dispersive surface energy to the increase in total surface energy was 87% for GS and 73% for WS chalk. A high relative proportion of dispersive component in the total surface energy is also typical for clay minerals (Chassin et al., 1986; Jouany and Chassin, 1987; Kádár et al., 2006).This demonstrates that the additional adsorption sites that are exposed by the extraction procedure are less polar than the sites originally exposed. Based on these results, we can conclude that chalk particles have surface sites of different polarity and that organic compounds preferentially adsorb at the less polar sites. These additional sites have quite similar surface properties for both North Sea chalk samples with an energy distribution that is similar to clays, that are described in the literature (Chassin et al., 1986; Jouany and Chassin, 1987; Kádár et al., 2006).The Ålborg chalk initially has minimal adsorbed organic material and the work of wetting changes very little after the treatment for extracting organic material. Considering the lower reproducibility of the results on Ålborg chalk, the differences in surface energies before and after extraction are considered insignificant and we conclude that the sample is not affected by the extraction procedure.The absolute values for the dispersive component of surface energy for North Sea chalks determined here are consistent with data obtained earlier by inverse gas chromatography (IGC) (Skovbjerg et al., 2013). Skovbjerg and colleagues reported values of γd for GS and WS chalk equal to 36.3 and 47.0 mJ/m2. The values reported for the polar components of the surface energy are, however, much lower. This difference is probably associated with the differences in the theoretical background for the two techniques. IGC measures surface interaction with vapours at close to zero coverage, using the Good-van Oss approach (van Oss et al., 1988), whereas the results obtained here are for surfaces fully covered by several layers of adsorbate and use the Owens-Wendt approach (Owens and Wendt, 1969). Our probe molecules (water and ethanol) are also more polar than the probe molecules used for the IGC experiments (dichloromethane and ethyl acetate), which probably leads to overestimation of values for the polar component of the surface energy.The total surface energy of the calcite samples that we obtained is close to reports for marble (Janczuk et al., 1983) and calcite (Goujon and Mutaftschiev, 1976; Okayama et al., 1997). There are, however, considerable differences in the values reported by different groups and in one case (Douillard et al., 1995), values reported are three times higher than our observations. We propose that the history of the samples, thus what is adsorbed on the surfaces, has a great deal to do with the surface tension measured.
A new green chemistry method based on plant extracts to synthesize gold nanoparticles

NASA Astrophysics Data System (ADS)

Montes Castillo, Milka Odemariz

Extraordinary chemical and physical properties exhibited by nanomaterials, as compared to their bulk counterparts, have made the area of nanotechnology a growing realm in the past three decades. It is the nanoscale size (from 1 to 100 nm) and the morphologies of nanomaterials that provide several properties and applications not possible for the same material in the bulk. Magnetic and optical properties, as well as surface reactivity are highly dependent on the size and morphology of the nanomaterial. Diverse nanomaterials are being widely used in molecular diagnostics as well as in medicine, electronic and optical devices. Among the most studied nanomaterials, gold nanoparticles are of special interest due to their multifunctional capabilities. For instance, spherical gold nanoparticles measuring 15-20 nm in diameter have been studied due to their insulin binding properties. Also, thiol functionalized gold nanoparticles between 5 and 30 nm are used in the detection of DNA. Thus, harnessing the shape and size of gold nanoparticles plays an important role in science and technology. The synthesis of gold nanoparticles via the reduction of gold salts, using citrate or other reducing agents, has been widely studied. In recent years, algae, fungi, bacteria, and living plants have been used to reduce trivalent gold (Au3+) to its zero oxidation state (Au 0) forming gold nanoparticles of different sizes and shapes. In addition, plant biomasses have also been studied for their gold-reducing power and nanoparticle formation. Although there is information about the synthesis of the gold nanoparticles by biologically based materials; to our knowledge, the study of the use of alfalfa extracts has not been reported. This innovation represents a significant improvement; that is an environmentally friendly method that does not use toxic chemicals. Also, the problem of extracting the formed gold nanoparticles from biomaterials is addressed in this research but still remains to be solved. In this work, secondary metabolites were extracted from alfalfa biomass in liquid phase by hot water, isopropanol, and methanol, and used to reduce tetrachloroaurate ion (AuCl4-) for the synthesis of gold nanoparticles. Biosyntheses of gold nanoparticles were performed by mixing 0.75, 1.5 and 3.0 mM Au3+ solutions with each one of the extracts at a ratio of 3:1 respectively, and shaken at room temperature for 1h. Resulting gold colloids were characterized by UV-Vis spectrophotometry and electron microscopy techniques, showing size and morphology dependency on the reaction conditions. Isopropanol alfalfa extracts reacted with Au 3+ produced gold nanoparticles with a size range of 15-60 nm. The most abundant were from 40-50 nm, and the morphologies found were polygons, decahedra and icosahedra. Methanol alfalfa extracts produced monodisperse 50 nm decahedral and icosahedral gold nanoparticles. Lastly, water alfalfa extracts reacted with Au3+ produced triangular, truncated triangular and hexagonal nanoplates with diameters ranging from 500 nm to 4 mum and thicknesses of ˜15-40 nm. The production of gold nanoplates by alfalfa extracts has never been reported before. In order to extract the formed gold nanoparticles from the biomass, physical and chemical extractions were used. For the chemical extraction, NaCl, dilute H2SO4, Triton X and DI water were tested. In these cases, the best results were obtained with DI water, followed by NaCl. The extracted nanoparticles had an absorption band at about 539 nm. For the physical extractions, alfalfa biomass containing gold nanoparticles were exposed to 400°C, 500°C, 550°C and 600°C to recover the gold nanoparticles. X-ray diffractograms taken after pyrolysis of the biomass showed that the recovered nanoparticles kept their crystal structure.
Site-specific transition metal occupation in multicomponent pyrophosphate for improved electrochemical and thermal properties in lithium battery cathodes: a combined experimental and theoretical study.

PubMed

Shakoor, Rana A; Kim, Heejin; Cho, Woosuk; Lim, Soo Yeon; Song, Hannah; Lee, Jung Woo; Kang, Jeung Ku; Kim, Yong-Tae; Jung, Yousung; Choi, Jang Wook

2012-07-18

As an attempt to develop lithium ion batteries with excellent performance, which is desirable for a variety of applications including mobile electronics, electrical vehicles, and utility grids, the battery community has continuously pursued cathode materials that function at higher potentials with efficient kinetics for lithium insertion and extraction. By employing both experimental and theoretical tools, herein we report multicomponent pyrophosphate (Li(2)MP(2)O(7), M = Fe(1/3)Mn(1/3)Co(1/3)) cathode materials with novel and advantageous properties as compared to the single-component analogues and other multicomponent polyanions. Li(2)Fe(1/3)Mn(1/3)Co(1/3)P(2)O(7) is formed on the basis of a solid solution among the three individual transition-metal-based pyrophosphates. The unique crystal structure of pyrophosphate and the first principles calculations show that different transition metals have a tendency to preferentially occupy either octahedral or pyramidal sites, and this site-specific transition metal occupation leads to significant improvements in various battery properties: a single-phase mode for Li insertion/extraction, improved cell potentials for Fe(2+)/Fe(3+) (raised by 0.18 eV) and Co(2+)/Co(3+) (lowered by 0.26 eV), and increased activity for Mn(2+)/Mn(3+) with significantly reduced overpotential. We reveal that the favorable energy of transition metal mixing and the sequential redox reaction for each TM element with a sufficient redox gap is the underlying physical reason for the preferential single-phase mode of Li intercalation/deintercalation reaction in pyrophosphate, a general concept that can be applied to other multicomponent systems. Furthermore, an extremely small volume change of ~0.7% between the fully charged and discharged states and the significantly enhanced thermal stability are observed for the present material, the effects unseen in previous multicomponent battery materials.
Micromagnetic measurement for characterization of ferromagnetic materials' microstructural properties

NASA Astrophysics Data System (ADS)

Zhang, Shuo; Shi, Xiaodong; Udpa, Lalita; Deng, Yiming

2018-05-01

Magnetic Barkhausen noise (MBN) is measured in low carbon steels and the relationship between carbon content and parameter extracted from MBN signal has been investigated. The parameter is extracted experimentally by fitting the original profiles with two Gaussian curves. The gap between two peaks (ΔG) of fitted Gaussian curves shows a better linear relationship with carbon contents of samples in the experiment. The result has been validated with simulation by Monte Carlo method. To ensure the sensitivity of measurement, advanced multi-objective optimization algorithm Non-dominant sorting genetic algorithm III (NSGA III) has been used to fulfill the optimization of the magnetic core of sensor.
Investigation of Primary Causes of Load-Related Cracking in Asphalt Concrete Pavement in North Carolina

NASA Astrophysics Data System (ADS)

Park, Hong Joon

This dissertation presents causes of cracking in asphalt concrete pavement in North Carolina through field investigation and laboratory experiments with field extracted material. North Carolina is experiencing higher than anticipated rates of fatigue cracking compared to other state. These higher than expected rates could be reflective of the national trends in mix design practice or could be caused by structural pavement failures. The problems associated with premature cracking in North Carolina pavements point to the need to evaluate the North Carolina Department of Transportation (NCDOT) mixes, processes, and measures to ensure that these factors properly balance the goals of preventing cracking and minimizing permanent deformation. Without solid data from in-service pavements, any conclusions regarding the causes of these failures might be pure conjecture. Accordingly, this research examines material properties through laboratory experiments using field-extracted materials and investigates in situ pavements and pavement structure. In order to assess condition of existing pavement, alligator cracking index (ACI) was developed. The asphalt content in the top layer that exhibits top-down cracking or bottom-up cracking has a proportional relationship to ACI values. The air void content in a bottom layer that exhibits top-down cracking or bottom-up cracking shows an inverse proportional relationship to ACI values. These observations reflect reasonable results. A comparison between ACI and asphalt film thickness values does not produce noteworthy findings, but somewhat reasonable results are evident once the range of comparison is narrowed down. Thicker film thicknesses show higher ACI values. From field core visual observations, road widening is identified as a major cause of longitudinal cracking. Regions with observed layer interface separation tend to have low ACI values. Through tensile strain simulation based on actual field conditions, it is observed that sites with observed bottom-up cracking have higher tensile strain levels at the bottom of the asphalt layer than sites with observed top-down cracking. Extracted binder fatigue test results indicate that binder properties between good and poor sections of a given site are not the result of differences in the binder properties. Hence, other mixture design factors are at work in controlling the site variability in terms of fatigue resistance.
High-temperature material characterization for multispectral window

NASA Astrophysics Data System (ADS)

Park, James; Arida, Marvin-Ray; Ku, Zahyun; Jang, Woo-Yong; Urbas, Augustine M.

2017-05-01

A microwave cylindrical cavity combined with a laser has been investigated to characterize the temperature dependence of widow materials in the Air Force Research Laboratory (AFRL). This paper discusses the requirements of high temperature RF material characterizations for transparent ceramic materials, such as ALON, that can potentially be used for multispectral windows. The RF cylindrical resonator was designed and the numerical model was studied to characterize the dielectric constant of materials. The dielectric constant can be extracted from the resonant frequency shift based on the cavity perturbation method (CPM), which is sensitive to the sample size and shape. Laser heating was applied to the material under test (MUT), which could easily be heated above 1000°C by the laser irradiation, in order to conduct CPM at high temperature. The temperature distribution in a material was also analyzed to investigate the impact of the thermal properties and the sample shape.
Silk Fibroin Degradation Related to Rheological and Mechanical Properties.

PubMed

Partlow, Benjamin P; Tabatabai, A Pasha; Leisk, Gary G; Cebe, Peggy; Blair, Daniel L; Kaplan, David L

2016-05-01

Regenerated silk fibroin has been proposed as a material substrate for biomedical, optical, and electronic applications. Preparation of the silk fibroin solution requires extraction (degumming) to remove contaminants, but results in the degradation of the fibroin protein. Here, a mechanism of fibroin degradation is proposed and the molecular weight and polydispersity is characterized as a function of extraction time. Rheological analysis reveals significant changes in the viscosity of samples while mechanical characterization of cast and drawn films shows increased moduli, extensibility, and strength upon drawing. Fifteen minutes extraction time results in degraded fibroin that generates the strongest films. Structural analysis by wide angle X-ray scattering (WAXS) and Fourier transform infrared spectroscopy (FTIR) indicates molecular alignment in the drawn films and shows that the drawing process converts amorphous films into the crystalline, β-sheet, secondary structure. Most interesting, by using selected extraction times, films with near-native crystallinity, alignment, and molecular weight can be achieved; yet maximal mechanical properties for the films from regenerated silk fibroin solutions are found with solutions subjected to some degree of degradation. These results suggest that the regenerated solutions and the film casting and drawing processes introduce more complexity than native spinning processes. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Thermo-responsive polymer tethered metal-organic framework core-shell magnetic microspheres for magnetic solid-phase extraction of alkylphenols from environmental water samples.

PubMed

Jia, Yuqian; Su, Hao; Wong, Y-L Elaine; Chen, Xiangfeng; Dominic Chan, T-W

2016-07-22

In this work, the thermo-responsive polymer PNIPAM tethered to Fe3O4@SiO2@MOF core-shell magnetic microspheres was first synthesized by a surface-selective post-synthetic strategy and underwent highly efficient magnetic solid-phase extraction (MSPE) of alkylphenols from aqueous samples. Alkylphenols, including 4-tert-octylphenol (OP) and 4-n-nonylphenol (NP), were selected as target compounds. The sample quantification was carried out using LC-MS/MS in multiple reaction monitor (MRM) mode. Under optimal working conditions, the developed method showed good linearity in the range of 5-1000ngL(-1), a low limit of detection (1.5ngL(-1)), and good repeatability (relative standard deviation, <8%, n=5) for NP and OP. Owning to the hydrophilic/hydrophobic switchable properties of the nanocomposite, high recoveries (78.7-104.3%) of alkylphenols were obtained under different extraction conditions. The levels of OP and NP in environmental samples collected from local river, lake and pond waters were analyzed using the developed method. It was believed that the synthesized material with the thermo-responsive coating, large surface areas and magnetic properties should have great potential in the extraction and removal of alkylphenols from environmental samples. Copyright © 2016 Elsevier B.V. All rights reserved.

Synthesis of hydrophilic and hydrophobic carbon quantum dots from waste of wine fermentation

NASA Astrophysics Data System (ADS)

Varisco, Massimo; Zufferey, Denis; Ruggi, Albert; Zhang, Yucheng; Erni, Rolf; Mamula, Olimpia

2017-12-01

Wine lees are one of the main residues formed in vast quantities during the fermentation of wine. While toxic when applied to plants and wetlands, it is a biodegradable material, and several alternatives have been proposed for its valorization as: dietary supplement in animal feed, source for various yeast extracts and bioconversion feedstock. The implementation of stricter environment protection regulations resulted in increasing costs for wineries as their treatment process constitutes an unavoidable and expensive step in wine production. We propose here an alternative method to reduce waste and add value to wine production by exploiting this rich carbon source and use it as a raw material for producing carbon quantum dots (CQDs). A complete synthetic pathway is discussed, comprising the carbonization of the starting material, the screening of the most suitable solvent for the extraction of CQDs from the carbonized mass and their hydrophobic or hydrophilic functionalization. CQDs synthesized with the reported procedure show a bright blue emission (λmax = 433 ± 13 nm) when irradiated at 366 nm, which is strongly shifted when the wavelength is increased (e.g. emission at around 515 nm when excited at 460 nm). Yields and luminescent properties of CQDs, obtained with two different methods, namely microwave and ultrasound-based extraction, are discussed and compared. This study shows how easy a residue can be converted into an added-value material, thus not only reducing waste and saving costs for the wine-manufacturing industry but also providing a reliable, affordable and sustainable source for valuable materials.
Synthesis of hydrophilic and hydrophobic carbon quantum dots from waste of wine fermentation

PubMed Central

Varisco, Massimo; Zufferey, Denis; Ruggi, Albert; Zhang, Yucheng; Erni, Rolf

2017-01-01

Wine lees are one of the main residues formed in vast quantities during the fermentation of wine. While toxic when applied to plants and wetlands, it is a biodegradable material, and several alternatives have been proposed for its valorization as: dietary supplement in animal feed, source for various yeast extracts and bioconversion feedstock. The implementation of stricter environment protection regulations resulted in increasing costs for wineries as their treatment process constitutes an unavoidable and expensive step in wine production. We propose here an alternative method to reduce waste and add value to wine production by exploiting this rich carbon source and use it as a raw material for producing carbon quantum dots (CQDs). A complete synthetic pathway is discussed, comprising the carbonization of the starting material, the screening of the most suitable solvent for the extraction of CQDs from the carbonized mass and their hydrophobic or hydrophilic functionalization. CQDs synthesized with the reported procedure show a bright blue emission (λmax = 433 ± 13 nm) when irradiated at 366 nm, which is strongly shifted when the wavelength is increased (e.g. emission at around 515 nm when excited at 460 nm). Yields and luminescent properties of CQDs, obtained with two different methods, namely microwave and ultrasound-based extraction, are discussed and compared. This study shows how easy a residue can be converted into an added-value material, thus not only reducing waste and saving costs for the wine-manufacturing industry but also providing a reliable, affordable and sustainable source for valuable materials. PMID:29308232
Application of cavitation system to accelerate aqueous enzymatic extraction of seed oil from Cucurbita pepo L. and evaluation of hypoglycemic effect.

PubMed

Li, Xiao-Juan; Li, Zhu-Gang; Wang, Xun; Han, Jun-Yan; Zhang, Bo; Fu, Yu-Jie; Zhao, Chun-Jian

2016-12-01

Cavitation-accelerated aqueous enzymatic extraction (CAEE) of seed oil from Cucurbita pepo was performed. An enzyme cocktail comprised of cellulose, pectinase and proteinase can work synergistically in releasing the oil. The CAEE extraction conditions were optimized by a Plackett-Burman design followed by a central composite methodology. A maximal extraction yield of 58.06% was achieved under optimal conditions of vacuum degree -0.07, enzyme amount 1.05% and extraction time 69min. As compared to soxhlet extraction (SE)-derived oil, CAEE-derived oil exhibited similar physical properties and better oxidation stability. In addition, chemical composition analyzing showed that the content of linoleic acid obtained by CAEE (47.67%) was higher than that of SE (44.51%). Moreover, the IC50 of oil obtained by CAEE and SE, as measured by α-amylase inhibition assay, were 40.68μg/mL and 45.46μg/mL. All results suggest that CAEE represents an excellent alternative protocol for production of oil from oil-bearing materials. Copyright © 2016 Elsevier Ltd. All rights reserved.
Recent advances of mesoporous materials in sample preparation.

PubMed

Zhao, Liang; Qin, Hongqiang; Wu, Ren'an; Zou, Hanfa

2012-03-09

Sample preparation has been playing an important role in the analysis of complex samples. Mesoporous materials as the promising adsorbents have gained increasing research interest in sample preparation due to their desirable characteristics of high surface area, large pore volume, tunable mesoporous channels with well defined pore-size distribution, controllable wall composition, as well as modifiable surface properties. The aim of this paper is to review the recent advances of mesoporous materials in sample preparation with emphases on extraction of metal ions, adsorption of organic compounds, size selective enrichment of peptides/proteins, specific capture of post-translational peptides/proteins and enzymatic reactor for protein digestion. Copyright Â© 2011 Elsevier B.V. All rights reserved.
Boron nitride as desalting material in combination with phosphopeptide enrichment in shotgun proteomics.

PubMed

Furuhashi, Takeshi; Nukarinen, Ella; Ota, Shigenori; Weckwerth, Wolfram

2014-05-01

Hydrophilic peptides in shotgun proteomics have been shown to be problematic in conventional chromatography. Typically, C18 solid phase extraction or peptide traps are used for desalting the sample prior to mass spectrometry analysis, but the capacity to retain hydrophilic peptides is not very high, causing a bias toward more hydrophobic peptides. This is particularly problematic in phosphoproteomic studies. We tested the compatibility of commercially available boron nitride as a novel material for peptide desalting. Boron nitride can be used to recover a wide range of peptides with different physicochemical properties comparable to combined C18 and graphite carbon material. Copyright © 2014. Published by Elsevier Inc.
Ultrasound assisted extraction of polysaccharides from hazelnut skin.

PubMed

Yılmaz, Tuncay; Tavman, Şebnem

2016-03-01

In this study ultrasound assisted extraction (UAE) of polysaccharides from hazelnut skin has been studied. Optimum sonication time has been evaluated depending on responses such as amount of carbohydrate and dried sample and thermogravimetric analysis. Chemical and structural properties of extracted material have been determined by Fourier transform spectroscopy attenuated-total reflectance (FTIR-ATR) spectroscopy. Pretreated hazelnut skin powders were extracted in distilled water. Mixture was sonicated by ultrasonic processor probe for 15, 30, 45, 60, 90, and 120 min. The results of UAE showed that maximum ethanol insoluble extracts in 60 min and the highest dry matter content could be obtained in 120 min extraction. Although total carbohydrate content of ethanol insoluble dry extract decreased with time, total carbohydrate in ethanol soluble fraction increased. Polysaccharides extracted from hazelnut skin were assumed to be pectic polysaccharide according to the literature survey of FTIR analysis result. Application time of UAE has an important effect on extraction of polysaccharide from hazelnut skin. This affect could be summarized by enhancing extraction yield up to critical level. Decrease of the yield in ethanol insoluble part could be explained by polymer decomposition. Most suitable model was hyperbolic model by having the lowest root mean square error and the highest R(2) values. © The Author(s) 2015.
Effects of fuel components and combustion particle physicochemical properties on toxicological responses of lung cells.

PubMed

Jaramillo, Isabel C; Sturrock, Anne; Ghiassi, Hossein; Woller, Diana J; Deering-Rice, Cassandra E; Lighty, JoAnn S; Paine, Robert; Reilly, Christopher; Kelly, Kerry E

2018-03-21

The physicochemical properties of combustion particles that promote lung toxicity are not fully understood, hindered by the fact that combustion particles vary based on the fuel and combustion conditions. Real-world combustion-particle properties also continually change as new fuels are implemented, engines age, and engine technologies evolve. This work used laboratory-generated particles produced under controlled combustion conditions in an effort to understand the relationship between different particle properties and the activation of established toxicological outcomes in human lung cells (H441 and THP-1). Particles were generated from controlled combustion of two simple biofuel/diesel surrogates (methyl decanoate and dodecane/biofuel-blended diesel (BD), and butanol and dodecane/alcohol-blended diesel (AD)) and compared to a widely studied reference diesel (RD) particle (NIST SRM2975/RD). BD, AD, and RD particles exhibited differences in size, surface area, extractable chemical mass, and the content of individual polycyclic aromatic hydrocarbons (PAHs). Some of these differences were directly associated with different effects on biological responses. BD particles had the greatest surface area, amount of extractable material, and oxidizing potential. These particles and extracts induced cytochrome P450 1A1 and 1B1 enzyme mRNA in lung cells. AD particles and extracts had the greatest total PAH content and also caused CYP1A1 and 1B1 mRNA induction. The RD extract contained the highest relative concentration of 2-ring PAHs and stimulated the greatest level of interleukin-8 (IL-8) and tumor necrosis factor-alpha (TNFα) cytokine secretion. Finally, AD and RD were more potent activators of TRPA1 than BD, and while neither the TRPA1 antagonist HC-030031 nor the antioxidant N-acetylcysteine (NAC) affected CYP1A1 or 1B1 mRNA induction, both inhibitors reduced IL-8 secretion and mRNA induction. These results highlight that differences in fuel and combustion conditions affect the physicochemical properties of particles, and these differences, in turn, affect commonly studied biological/toxicological responses.
Spectroscopic Ellipsometry Studies of Ag and ZnO Thin Films and Their Interfaces for Thin Film Photovoltaics

NASA Astrophysics Data System (ADS)

Sainju, Deepak

Many modern optical and electronic devices, including photovoltaic devices, consist of multilayered thin film structures. Spectroscopic ellipsometry (SE) is a critically important characterization technique for such multilayers. SE can be applied to measure key parameters related to the structural, optical, and electrical properties of the components of multilayers with high accuracy and precision. One of the key advantages of this non-destructive technique is its capability of monitoring the growth dynamics of thin films in-situ and in real time with monolayer level precision. In this dissertation, the techniques of SE have been applied to study the component layer materials and structures used as back-reflectors and as the transparent contact layers in thin film photovoltaic technologies, including hydrogenated silicon (Si:H), copper indium-gallium diselenide (CIGS), and cadmium telluride (CdTe). The component layer materials, including silver and both intrinsic and doped zinc oxide, are fabricated on crystalline silicon and glass substrates using magnetron sputtering techniques. These thin films are measured in-situ and in real time as well as ex-situ by spectroscopic ellipsometry in order to extract parameters related to the structural properties, such as bulk layer thickness and surface roughness layer thickness and their time evolution, the latter information specific to real time measurements. The index of refraction and extinction coefficient or complex dielectric function of a single unknown layer can also be obtained from the measurement versus photon energy. Applying analytical expressions for these optical properties versus photon energy, parameters that describe electronic transport, such as electrical resistivity and electron scattering time, can be extracted. The SE technique is also performed as the sample is heated in order to derive the effects of annealing on the optical properties and derived electrical transport parameters, as well as the intrinsic temperature dependence of these properties and parameters. One of the major achievements of this dissertation research is the characterization of the thickness and optical properties of the interface layer formed between the silver and zinc oxide layers in a back-reflector structure used in thin film photovoltaics. An understanding of the impact of these thin film material properties on solar cell device performance has been complemented by applying reflectance and transmittance spectroscopy as well as simulations of cell performance.
Test to Extract Soil Properties Using the Seismic HammerTM Active Seismic Source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Rebekah F.; Abbott, Robert E.

Geologic material properties are necessary parameters for ground motion modeling and are difficult and expensive to obtain via traditional methods. Alternative methods to estimate soil properties require a measurement of the ground's response to a force. A possible method of obtaining these measurements is active-source seismic surveys, but measurements of the ground response at the source must also be available. The potential of seismic sources to obtain soil properties is limited, however, by the repeatability of the source. Explosives, and hammer surveys are not repeatable because of variable ground coupling or swing strength. On the other hand, the Seismic Hammermore » TM (SH) is consistent in the amount of energy it inputs into the ground. In addition, it leaves large physical depressions as a result of ground compaction. The volume of ground compaction varies by location. Here, we hypothesize that physical depressions left in the earth by the SH correlate to energy recorded by nearby geophones, and therefore are a measurement of soil physical properties. Using measurements of the volume of shot holes, we compare the spatial distribution of the volume of ground compacted between the different shot locations. We then examine energy recorded by the nearest 50 geophones and compare the change in amplitude across hits at the same location. Finally, we use the percent difference between the energy recorded by the first and later hits at a location to test for a correlation to the volume of the shot depressions. We find that: * Ground compaction at the shot-depression does cluster geographically, but does not correlate to known surface features. * Energy recorded by nearby geophones reflects ground refusal after several hits. * There is no correlation to shot volume and changes in energy at particular shot locations. Deeper material properties (i.e. below the depth of surface compaction) may be contributing to the changes in energy propagation. * Without further processing of the data, shot-depression volumes are insufficient to understanding ground response to the SH. Without an accurate understanding of the ground response, we cannot extract material properties in conjunction with the SH survey. Additional processing including picking direct arrivals and static corrections may yield positive results.« less
Simultaneous Measurement of Thermal Conductivity and Specific Heat in a Single TDTR Experiment

NASA Astrophysics Data System (ADS)

Sun, Fangyuan; Wang, Xinwei; Yang, Ming; Chen, Zhe; Zhang, Hang; Tang, Dawei

2018-01-01

Time-domain thermoreflectance (TDTR) technique is a powerful thermal property measurement method, especially for nano-structures and material interfaces. Thermal properties can be obtained by fitting TDTR experimental data with a proper thermal transport model. In a single TDTR experiment, thermal properties with different sensitivity trends can be extracted simultaneously. However, thermal conductivity and volumetric heat capacity usually have similar trends in sensitivity for most materials; it is difficult to measure them simultaneously. In this work, we present a two-step data fitting method to measure the thermal conductivity and volumetric heat capacity simultaneously from a set of TDTR experimental data at single modulation frequency. This method takes full advantage of the information carried by both amplitude and phase signals; it is a more convenient and effective solution compared with the frequency-domain thermoreflectance method. The relative error is lower than 5 % for most cases. A silicon wafer sample was measured by TDTR method to verify the two-step fitting method.
Grid indentation analysis of mechanical properties of composite electrodes in Li-ion batteries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vasconcelos, Luize Scalco de; Xu, Rong; Li, Jianlin

We report that electrodes in commercial rechargeable batteries are microscopically heterogeneous materials. The constituent components, including active materials, polymeric binders, and porous conductive matrix, often have large variation in their mechanical properties, making the mechanical characterization of composite electrodes a challenging task. In a model system of LiNi 0.5Mn 0.3Co 0.2O 2 cathode, we employ the instrumented grid indentation to determine the elastic modulus and hardness of the constituent phases. The approach relies on a large array of nanoindentation experiments and statistical analysis of the resulting data provided that the maximum indentation depth is carefully chosen. The statistically extracted propertiesmore » of the active particles and the surrounding medium are in good agreement with the tests of targeted indentation at selected sites. Lastly, the combinatory technique of grid indentation and statistical deconvolution represents a fast and reliable route to quantify the mechanical properties of composite electrodes that feed the parametric input for the mechanics models.« less
Grid indentation analysis of mechanical properties of composite electrodes in Li-ion batteries

DOE PAGES

Vasconcelos, Luize Scalco de; Xu, Rong; Li, Jianlin; ...

2016-03-09

We report that electrodes in commercial rechargeable batteries are microscopically heterogeneous materials. The constituent components, including active materials, polymeric binders, and porous conductive matrix, often have large variation in their mechanical properties, making the mechanical characterization of composite electrodes a challenging task. In a model system of LiNi 0.5Mn 0.3Co 0.2O 2 cathode, we employ the instrumented grid indentation to determine the elastic modulus and hardness of the constituent phases. The approach relies on a large array of nanoindentation experiments and statistical analysis of the resulting data provided that the maximum indentation depth is carefully chosen. The statistically extracted propertiesmore » of the active particles and the surrounding medium are in good agreement with the tests of targeted indentation at selected sites. Lastly, the combinatory technique of grid indentation and statistical deconvolution represents a fast and reliable route to quantify the mechanical properties of composite electrodes that feed the parametric input for the mechanics models.« less
Antioxidant capacity and fatty acid composition of different parts of Adenocarpus complicatus (Fabaceae) from Turkey.

PubMed

Berber, Adnan; Zengin, Gokhan; Aktumsek, Abdurrahman; Sanda, Murad Aydin; Uysal, Tuna

2014-03-01

Adenocarpus complicatus is distributed throughout the Anatolian peninsula and is widely used for human and animal nutrition. The purpose of this work was to study the antioxidant properties and fatty acid composition of different parts of this plant (fruits and mixed materials). The species was collected from Golyuzu village of the Seydisehir district near Konya province, Turkey. Fruit and mixed parts obtained from this species were ground and a 15g sample was used to prepare methanolic extracts. Powdered plant samples were extracted with 100mL methanol in a mechanical shaker. The obtained extracts were filtered and concentrated to dryness under reduced pressure and were subsequently stored at -20 degrees C. Antioxidant components, namely total phenolic and flavonoid content, were detected for each extract using spectrophotometric methods. Antioxidant capacity was evaluated by various assays including phosphomolybdenum, DPPH free radical scavenging capacity, metal chelating activity, and ferric and cupric ion reducing power. The fatty acid profiles of plant parts were also determined by using gas chromatography. The total phenolic content of fruit (36.21mgGAE/g) was higher than that of mixed materials (13.79mgGAE/g). The methanolic extract of mixed material had higher amounts of flavonoid than fruit extract. The free radical scavenging activity of extracts was expressed as IC50 value (microg/mL) (amount required to inhibit DPPH radical formation by 50%). The lower IC50 value reflects better free radical scavenging action. The radical scavenging activity of the samples was compared with BHT, it showed the mixed material to be almost two times more potent than the fruit extract. However, BHT is an excellent free radical scavenger with an IC50 of 34.061 microg/mL. The ferric and cupric reducing power potentials of the extracts were expressed as EC50 value (the effective concentration at which the absorbance was 0.5). Fruit extract exhibited strong ferric reducing power with an EC50 of 871.25 microg/mL. The metal chelating activity of the extracts increased with concentration. Chelating effect was 83.60% for fruit extract at 1mg/mL concentration. Oil content of fruit and mixed parts were detected as 6.71 and 6.14%, respectively. A total of 32 fatty acids were found in the oil. Essential fatty acids (linoleic and a-linolenic acid) were identified as the most abundant fatty acids in the oil. These results demonstrated that this plant species can be considered as an alternative to synthetic antioxidants. Likewise, the oil obtained from the plant can be used as a source of essential fatty acids for food and pharmacological applications.
The optical properties of regenerated silk fibroin films obtained from different sources

NASA Astrophysics Data System (ADS)

Perotto, Giovanni; Zhang, Yuji; Naskar, Deboki; Patel, Nereus; Kaplan, David L.; Kundu, Subhas C.; Omenetto, Fiorenzo G.

2017-09-01

Silk fibroin possesses unique properties for bio-functional optical interfaces and has been attracting increasing interest as an optical material. Here, we report on the refractive index and absorption coefficient of silk fibroin extracted from Bombyx mori, Antheraea mylitta, Samia ricini, and Antheraea assamensis. The influence of protein molecular weight, residual water content, and crystallinity on refractive index was investigated. The parameters for the Cauchy dispersion law and Urbach absorption were determined for each of the silk fibroins. By exploiting the differences in refractive index between the different fibroins, an all-protein slab waveguide was fabricated.
Foaming and emulsifying properties of pectin isolated from different plant materials

NASA Astrophysics Data System (ADS)

Yancheva, Nikoleta; Markova, Daniela; Murdzheva, Dilyana; Vasileva, Ivelina; Slavov, Anton

2016-03-01

The foaming and emulsifying properties of pectins obtained from waste rose petals, citrus pressings, grapefruit peels and celery were studied. It was found that the highest foaming capacity showed pectin derived from celery. The effect of pectin concentration on the foaming capacity of pectin solutions was investigated. For all the investigated pectins increasing the concentration led to increase of the foaming capacity. Emulsifying activity and emulsion stability of model emulsion systems (50 % oil phase) with 0.6 % pectic solutions were determined. The highest emulsifying activity and stability showed pectin isolated by dilute acid extraction from waste rose petals.
Valorization of spent coffee grounds recycling as a potential alternative fuel resource in Turkey: An experimental study.

PubMed

Atabani, A E; Mercimek, S M; Arvindnarayan, Sundaram; Shobana, Sutha; Kumar, Gopalakrishnan; Cadir, Mehmet; Al-Muhatseb, Ala'a H

2018-03-01

In this study, recycling of spent coffee grounds (SCG) as a potential feedstock for alternative fuel production and compounds of added value in Turkey was assessed. The average oil content was found (≈ 13% w/w). All samples (before and after extraction) were tested for scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), X-ray diffraction (XRD), calorific value, surface analysis and porosity, Fourier transform infrared (FT-IR), and elemental analysis to assess their potential towards fuel properties. Elemental analysis indicated that carbon represents the highest percentages (49.59% and 46.42%, respectively), followed by nitrogen (16.7% and 15.5%), hydrogen (6.74% and 6.04%), and sulfur (0.851% and 0.561%). These results indicate that SCG can be utilized as compost, as it is rich in nitrogen. Properties of the extracted oil were examined, followed by biodiesel production. The quality of biodiesel was compared with American Society for Testing and Materials (ASTM) D6751 standards, and all the properties complied with standard specifications. The fatty acid compositions were analyzed by gas chromatography. It was observed that coffee waste methyl ester (CWME) is mainly composed of palmitic (35.8%) and arachidic (44.6%) acids, which are saturated fatty acids. The low degree of unsaturation provides an excellent oxidation stability (10.4 hr). CWME has also excellent cetane number, higher heating value, and iodine value with poor cold flow properties. The studies also investigated blending of biodiesel with Euro diesel and butanol. Following this, a remarkable improvement in cloud and pour points of biodiesel was obtained. Spent coffee grounds after oil extraction is an ideal material for garden fertilizer, feedstock for ethanol, biogas production, and as fuel pellets. The outcome of such research work produces valuable insights on the recycling importance of SCG in Turkey. Coffee is a huge industry, and coffee has been widely used due to its refreshing properties. This industry generates large quantities of waste. Therefore, recycling of spent coffee grounds for producing alternative fuels and compounds of added value is crucial. Elemental analysis indicated that coffee waste can be utilized as compost, as it is rich in nitrogen. Coffee waste after oil extraction is an ideal feedstock for ethanol and biogas production, garden fertilizer, and as fuel pellets. The low degree of unsaturation provides excellent oxidation stability. Its biodiesel has also excellent cetane number, higher heating value, and lower iodine value.
Recent Advances in Food-Packing, Pharmaceutical and Biomedical Applications of Zein and Zein-Based Materials

PubMed Central

Corradini, Elisângela; Curti, Priscila S.; Meniqueti, Adriano B.; Martins, Alessandro F.; Rubira, Adley F.; Muniz, Edvani Curti

2014-01-01

Zein is a biodegradable and biocompatible material extracted from renewable resources; it comprises almost 80% of the whole protein content in corn. This review highlights and describes some zein and zein-based materials, focusing on biomedical applications. It was demonstrated in this review that the biodegradation and biocompatibility of zein are key parameters for its uses in the food-packing, biomedical and pharmaceutical fields. Furthermore, it was pointed out that the presence of hydrophilic-hydrophobic groups in zein chains is a very important aspect for obtaining material with different hydrophobicities by mixing with other moieties (polymeric or not), but also for obtaining derivatives with different properties. The physical and chemical characteristics and special structure (at the molecular, nano and micro scales) make zein molecules inherently superior to many other polymers from natural sources and synthetic ones. The film-forming property of zein and zein-based materials is important for several applications. The good electrospinnability of zein is important for producing zein and zein-based nanofibers for applications in tissue engineering and drug delivery. The use of zein’s hydrolysate peptides for reducing blood pressure is another important issue related to the application of derivatives of zein in the biomedical field. It is pointed out that the biodegradability and biocompatibility of zein and other inherent properties associated with zein’s structure allow a myriad of applications of such materials with great potential in the near future. PMID:25486057
Recent advances in food-packing, pharmaceutical and biomedical applications of zein and zein-based materials.

PubMed

Corradini, Elisângela; Curti, Priscila S; Meniqueti, Adriano B; Martins, Alessandro F; Rubira, Adley F; Muniz, Edvani Curti

2014-12-04

Zein is a biodegradable and biocompatible material extracted from renewable resources; it comprises almost 80% of the whole protein content in corn. This review highlights and describes some zein and zein-based materials, focusing on biomedical applications. It was demonstrated in this review that the biodegradation and biocompatibility of zein are key parameters for its uses in the food-packing, biomedical and pharmaceutical fields. Furthermore, it was pointed out that the presence of hydrophilic-hydrophobic groups in zein chains is a very important aspect for obtaining material with different hydrophobicities by mixing with other moieties (polymeric or not), but also for obtaining derivatives with different properties. The physical and chemical characteristics and special structure (at the molecular, nano and micro scales) make zein molecules inherently superior to many other polymers from natural sources and synthetic ones. The film-forming property of zein and zein-based materials is important for several applications. The good electrospinnability of zein is important for producing zein and zein-based nanofibers for applications in tissue engineering and drug delivery. The use of zein's hydrolysate peptides for reducing blood pressure is another important issue related to the application of derivatives of zein in the biomedical field. It is pointed out that the biodegradability and biocompatibility of zein and other inherent properties associated with zein's structure allow a myriad of applications of such materials with great potential in the near future.
Testing of the permanent magnet material Mn-Al-C for potential use in propulsion motors for electric vehicles

NASA Technical Reports Server (NTRS)

Abdelnour, Z. A.; Mildrum, H. F.; Strnat, K. J.

1980-01-01

The development of Mn-Al-C permanent magnets is reviewed. The general properties of the material are discussed and put into perspective relative to alnicos and ferrites. The commercial material now available is described by the manufacturer's data. The traction motor designer's demands of a permanent magnet for potential use in electric vehicle drives are reviewed. From this, a list of the needed specific information is extracted. A plan for experimental work is made which would generate this information, or verify data supplied by the producer. The results of these measurements are presented in the form of tables and graphs. The tests determined magnetic design data and some mechanical strength properties. Easy axis hysteresis and demagnetization curves, recoil loops and other minor loop fields were measured over a temperature range from -50 C to +150 C. Hysteresis loops were also measured for three orthogonal directions (the easy and 2 hard axes of magnetization).
Temperature-dependent microindentation data of an epoxy composition in the glassy region

NASA Astrophysics Data System (ADS)

Minster, Jiří; Králík, Vlastimil

2015-02-01

The short-term instrumented microindentation technique was applied for assessing the influence of temperature in the glassy region on the time-dependent mechanical properties of an average epoxy resin mix near to its native state. Linear viscoelasticity theory with the assumption of time-independent Poisson ratio value forms the basis for processing the experimental results. The sharp standard Berkovich indenter was used to measure the local mechanical properties at temperatures 20, 24, 28, and 35 °C. The short-term viscoelastic compliance histories were defined by the Kohlrausch-Williams-Watts double exponential function. The findings suggest that depth-sensing indentation data of thermorheologically simple materials influenced by different temperatures in the glassy region can also be used, through the time-temperature superposition, to extract viscoelastic response functions accurately. This statement is supported by the comparison of the viscoelastic compliance master curve of the tested material with data derived from standard macro creep measurements under pressure on the material in a conformable state.

High-throughput determination of structural phase diagram and constituent phases using GRENDEL

NASA Astrophysics Data System (ADS)

Kusne, A. G.; Keller, D.; Anderson, A.; Zaban, A.; Takeuchi, I.

2015-11-01

Advances in high-throughput materials fabrication and characterization techniques have resulted in faster rates of data collection and rapidly growing volumes of experimental data. To convert this mass of information into actionable knowledge of material process-structure-property relationships requires high-throughput data analysis techniques. This work explores the use of the Graph-based endmember extraction and labeling (GRENDEL) algorithm as a high-throughput method for analyzing structural data from combinatorial libraries, specifically, to determine phase diagrams and constituent phases from both x-ray diffraction and Raman spectral data. The GRENDEL algorithm utilizes a set of physical constraints to optimize results and provides a framework by which additional physics-based constraints can be easily incorporated. GRENDEL also permits the integration of database data as shown by the use of critically evaluated data from the Inorganic Crystal Structure Database in the x-ray diffraction data analysis. Also the Sunburst radial tree map is demonstrated as a tool to visualize material structure-property relationships found through graph based analysis.
Experimental and theoretical description of the optical properties of Myrcia sylvatica essential oil.

PubMed

Silva Prado, Andriele da; Leal, Luciano Almeida; de Brito, Patrick Pascoal; de Almeida Fonseca, Antonio Luciano; Blawid, Stefan; Ceschin, Artemis Marti; Veras Mourão, Rosa Helena; da Silva Júnior, Antônio Quaresma; Antonio da Silva Filho, Demétrio; Ribeiro Junior, Luiz Antonio; Ferreira da Cunha, Wiliam

2017-07-01

We present an extensive study of the optical properties of Myrcia sylvatica essential oil with the goal of investigating the suitability of its material system for uses in organic photovoltaics. The methods of extraction, experimental analysis, and theoretical modeling are described in detail. The precise composition of the oil in our samples is determined via gas chromatography, mass spectrometry, and X-ray scattering techniques. The measurements indicate that, indeed, the material system of Myrcia sylvatica essential oil may be successfully employed for the design of organic photovoltaic devices. The optical absorption of the molecules that compose the oil are calculated using time-dependent density functional theory and used to explain the measured UV-Vis spectra of the oil. We show that it is sufficient to consider the α-bisabolol/cadalene pair, two of the main constituents of the oil, to obtain the main features of the UV-Vis spectra. This finding is of importance for future works that aim to use Myrcia sylvatica essential oil as a photovoltaic material.
Optimization of hydrothermal pretreatment and membrane filtration processes of various feedstocks to isolate hemicelluloses for biopolymer applications

NASA Astrophysics Data System (ADS)

Sukhbaatar, Badamkhand

Hemicelluloses (HC) are the second most abundant plant polysaccharides after cellulose, constituting 25-30% of plant materials. In spite of their abundance, HC are not effectively utilized. Recently, considerable interest has been directed to HC-based biomaterials because of their high oxygen barrier properties, which has potential in food packaging applications. In this study, HC were extracted from sugarcane bagasse and southern yellow pine using a hydrothermal technique which utilizes hot compressed water without catalyst. The parameters affecting the yield of extracted HC such as temperature, time and pressure, were tested and optimized. Eighty four percent of xylose was extracted from sugarcane bagasse at the optimum condition, 180 °C 30 min and 1 MPa pressure. In the case of southern yellow pine, 79% of the mannose was extracted at 190 °C for 10 min and 2 MPa pressure. Concentration and isolation of HC from bagasse and southern yellow pine HC extract were performed by membrane filtration and freeze drying systems. Isolated HC were characterized by FT-IR and 13C NMR techniques and used as a starting material for film preparation. Films were prepared in 0/100, 50/50, 60/40, 70/30 and 80/20% ratios of HC and sodium carboxymethylcellulose (CMC). Thirty five percent of sorbitol (w/w of HC and CMC weight) was also added as a plasticizer. Films were evaluated by measuring water absorption, water vapor permeability (WVP), tensile property and oxygen barrier capability. At 55% relative humidity (RH) and 25 °C the water absorption of both sugarcane bagasse and southern yellow pine HC-based films tended to increase as HC content increased. The lowest WVP of sugarcane bagasse (3.84e-12 g/Pa h m) and southern yellow pine HC films (2.18e-12 g/Pa h m) were determined in 60/40 HC/CMC films. Tensile test results showed that as HC content increases the Young's modulus decreases, deflection at maximum load and percentage of strain at break increase. It implies that the film properties are changing from stiff to elastic. The oxygen permeability for 60/40 bagasse HC/CMC film was 0.005265 cc μm / (m2 day kPa) and for 70/30 pine HC/CMC film was 0.007570 cc μm / (m2 day kPa).
Measurement and Modeling of Dispersive Pulse Propagation in Drawn Wire Waveguides

NASA Technical Reports Server (NTRS)

Madaras, Eric I.; Kohl, Thomas W.; Rogers, Wayne P.

1995-01-01

An analytical model of dispersive pulse propagation in semi-infinite cylinders due to transient axially symmetric end conditions has been experimentally investigated. Specifically, the dispersive propagation of the first axially symmetric longitudinal mode in thin wire waveguides, which have ends in butt contact with longitudinal piezoelectric ultrasonic transducers, is examined. The method allows for prediction of a propagated waveform given a measured source waveform, together with the material properties of the cylinder. Alternatively, the source waveform can be extracted from measurement of the propagated waveform. The material properties required for implementation of the pulse propagation model are determined using guided wave phase velocity measurements. Hard tempered aluminum 1100 and 304 stainless steel wires, with 127, 305, and 406 micron diam., were examined. In general, the drawn wires were found to behave as transversely isotropic media.
Measurement and modeling of dispersive pulse propagation in draw wire waveguides

NASA Technical Reports Server (NTRS)

Madaras, Eric I.; Kohl, Thomas W.; Rogers, Wayne P.

1995-01-01

An analytical model of dispersive pulse propagation in semi-infinite cylinders due to transient axially symmetric end conditions has been experimentally investigated. Specifically, the dispersive propagation of the first axially symmetric longitudinal mode in thin wire waveguides, which have ends in butt contact with longitudinal piezoelectric ultrasonic transducers, is examined. The method allows for prediction of a propagated waveform given a measured source waveform, together with the material properties of the cylinder. Alternatively, the source waveform can be extracted from measurement of the propagated waveform. The material properties required for implementation of the pulse propagation model are determined using guided wave phase velocity measurements. Hard tempered aluminum 1100 and 304 stainless steel wires, with 127, 305, and 406 micron diam., were examined. In general, the drawn wires were found to behave as transversely isotropic media.
DOE Office of Scientific and Technical Information (OSTI.GOV)

E.N. Stepanov; I.I. Mel'nikov; V.P. Gridasov

In active production at OAO Magnitogorskii Metallurgicheskii Kombinat (MMK), samples of melt materials were taken during shutdown and during planned repairs at furnaces 1 and 8. In particular, coke was taken from the tuyere zone at different distances from the tuyere tip. The mass of the point samples was 2-15 kg, depending on the sampling zone. The material extracted from each zone underwent magnetic separation and screening by size class. The resulting coke sample was averaged out and divided into parts: one for determining the granulometric composition and mechanical strength; and the other for technical analysis and determination of themore » physicochemical properties of the coke.« less
Biologically-inspired data decorrelation for hyper-spectral imaging

NASA Astrophysics Data System (ADS)

Picon, Artzai; Ghita, Ovidiu; Rodriguez-Vaamonde, Sergio; Iriondo, Pedro Ma; Whelan, Paul F.

2011-12-01

Hyper-spectral data allows the construction of more robust statistical models to sample the material properties than the standard tri-chromatic color representation. However, because of the large dimensionality and complexity of the hyper-spectral data, the extraction of robust features (image descriptors) is not a trivial issue. Thus, to facilitate efficient feature extraction, decorrelation techniques are commonly applied to reduce the dimensionality of the hyper-spectral data with the aim of generating compact and highly discriminative image descriptors. Current methodologies for data decorrelation such as principal component analysis (PCA), linear discriminant analysis (LDA), wavelet decomposition (WD), or band selection methods require complex and subjective training procedures and in addition the compressed spectral information is not directly related to the physical (spectral) characteristics associated with the analyzed materials. The major objective of this article is to introduce and evaluate a new data decorrelation methodology using an approach that closely emulates the human vision. The proposed data decorrelation scheme has been employed to optimally minimize the amount of redundant information contained in the highly correlated hyper-spectral bands and has been comprehensively evaluated in the context of non-ferrous material classification
Development of a pepper-pot emittance meter for diagnostics of low-energy multiply charged heavy ion beams extracted from an ECR ion source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nagatomo, T., E-mail: nagatomo@riken.jp; Kase, M.; Kamigaito, O.

2016-02-15

Several fluorescent materials were tested for use in the imaging screen of a pepper-pot emittance meter that is suitable for investigating the beam dynamics of multiply charged heavy ions extracted from an ECR ion source. SiO{sub 2} (quartz), KBr, Eu-doped CaF{sub 2}, and Tl-doped CsI crystals were first irradiated with 6.52-keV protons to determine the effects of radiation damage on their fluorescence emission properties. For such a low-energy proton beam, only the quartz was found to be a suitable fluorescent material, since the other materials suffered a decay in fluorescence intensity with irradiation time. Subsequently, quartz was irradiated with heavymore » {sup 12}C{sup 4+}, {sup 16}O{sup 4+}, and {sup 40}Ar{sup 11+} ions, but it was found that the fluorescence intensity decreased too rapidly to measure the emittance of these heavy-ion beams. These results suggest that a different energy loss mechanism occurs for heavier ions and for protons.« less
Optimization of Process Parameters and Kinetic Model of Enzymatic Extraction of Polyphenols from Lonicerae Flos

PubMed Central

Kong, Fansheng; Yu, Shujuan; Bi, Yongguang; Huang, Xiaojun; Huang, Mengqian

2016-01-01

Objective: To optimize and verify the cellulase extraction of polyphenols from honeysuckle and provide a reference for enzymatic extracting polyphenols from honeysuckle. Materials and Methods: The uniform design was used According to Fick's first law and kinetic model, fitting analysis of the dynamic process of enzymatic extracting polyphenols was conducted. Results: The optimum enzymatic extraction parameters for polyphenols from honeysuckle are found to be 80% (v/v) of alcohol, 35:1 (mL/g) of liquid-solid ratio, 80°C of extraction temperature, 8.5 of pH, 6.0 mg of enzyme levels, and 130 min of extraction time. Under the optimal conditions, the extraction rate of polyphenols was 3.03%. The kinetic experiments indicated kinetic equation had a good linear relationship with t even under the conditions of different levels of enzyme and temperature, which means fitting curve tallies well with the experimental values. Conclusion: The results of quantification showed that the results provide a reference for enzymatic extracting polyphenols from honeysuckle. SUMMARY Lonicerae flos (Lonicera japonica Thunb.) is a material of traditional Chinese medicine and healthy drinks, of which active compounds mainly is polyphenols. At present, plant polyphenols are the hotspots centents of food, cosmetic and medicine, because it has strong bioactivity. Several traditional methods are available for the extraction of plant polyphenols including impregnation, solvent extraction, ultrasonic extraction, hot-water extraction, alkaline dilute alcohol or alkaline water extraction, microwave extraction and Supercritical CO2 extraction. But now, an increasing number of research on using cellulase to extract active ingredients from plants. Enzymatic method is widely used for enzyme have excellent properties of high reaction efficiency and specificity, moderate reaction conditions, shorter extraction time and easier to control, less damage to the active ingredient. At present, the enzymatic extraction of polyphenols from honeysuckle and dynamic had not been reported. In this study, using cellulase to extract polyphenols from honeysuckle is first applied. Moreover, uniform design was used to optimize process and kinetic model of extraction was established to analyze the characteristics of enzymatic extraction, in order to improve the yield of polyphenols from honeysuckle and make maximum use of Lonicerae flos, which provide references for industrial production. PMID:27018039
Transition metal oxides for organic electronics: energetics, device physics and applications.

PubMed

Meyer, Jens; Hamwi, Sami; Kröger, Michael; Kowalsky, Wolfgang; Riedl, Thomas; Kahn, Antoine

2012-10-23

During the last few years, transition metal oxides (TMO) such as molybdenum tri-oxide (MoO(3) ), vanadium pent-oxide (V(2) O(5) ) or tungsten tri-oxide (WO(3) ) have been extensively studied because of their exceptional electronic properties for charge injection and extraction in organic electronic devices. These unique properties have led to the performance enhancement of several types of devices and to a variety of novel applications. TMOs have been used to realize efficient and long-term stable p-type doping of wide band gap organic materials, charge-generation junctions for stacked organic light emitting diodes (OLED), sputtering buffer layers for semi-transparent devices, and organic photovoltaic (OPV) cells with improved charge extraction, enhanced power conversion efficiency and substantially improved long term stability. Energetics in general play a key role in advancing device structure and performance in organic electronics; however, the literature provides a very inconsistent picture of the electronic structure of TMOs and the resulting interpretation of their role as functional constituents in organic electronics. With this review we intend to clarify some of the existing misconceptions. An overview of TMO-based device architectures ranging from transparent OLEDs to tandem OPV cells is also given. Various TMO film deposition methods are reviewed, addressing vacuum evaporation and recent approaches for solution-based processing. The specific properties of the resulting materials and their role as functional layers in organic devices are discussed. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Differently Environment Stable Bio-Silver Nanoparticles: Study on Their Optical Enhancing and Antibacterial Properties

PubMed Central

Balachandran, Yekkuni L.; Girija, Shanmugam; Selvakumar, Rajendran; Tongpim, Saowanit; Gutleb, Arno C.; Suriyanarayanan, Sarvajeyakesavalu

2013-01-01

Generally, limited research is extended in studying stability and applicational properties of silver nanoparticles (Ag NPs) synthesized by adopting ‘green chemistry’ protocol. In this work, we report on the synthesis of stable Ag NPs using plant-derived materials such as leaf extract of Neem (Azadirachta indica) and biopolymer pectin from apple peel. In addition, the applicational properties of Ag NPs such as surface-enhanced Raman scattering (SERS) and antibacterial efficiencies were also investigated. As-synthesized nanoparticles (NPs) were characterized using various instrumentation techniques. Both the plant materials (leaf extract and biopolymer) favored the synthesis of well-defined NPs capped with biomaterials. The NPs were spherical in shape with an average particle size between 14-27 nm. These bio-NPs exhibited colloidal stability in most of the suspended solutions such as water, electrolyte solutions (NaCl; NaNO3), biological solution (bovine serum albumin), and in different pH solutions (pH 7; 9) for a reasonable time period of 120 hrs. Both the bio-NPs were observed to be SERS active through displaying intrinsic SERS signals of the Raman probe molecule (Nile blue A). The NPs were effective against the Escherichia coli bacterium when tested in nutrient broth and agar medium. Scanning and high-resolution transmission electron microscopy (SEM and HRTEM) images confirmed cellular membrane damage of nanoparticle treated E. coli cells. These environmental friendly template Ag NPs can be used as an antimicrobial agent and also for SERS based analytical applications. PMID:24130832
Statistical and sampling issues when using multiple particle tracking

NASA Astrophysics Data System (ADS)

Savin, Thierry; Doyle, Patrick S.

2007-08-01

Video microscopy can be used to simultaneously track several microparticles embedded in a complex material. The trajectories are used to extract a sample of displacements at random locations in the material. From this sample, averaged quantities characterizing the dynamics of the probes are calculated to evaluate structural and/or mechanical properties of the assessed material. However, the sampling of measured displacements in heterogeneous systems is singular because the volume of observation with video microscopy is finite. By carefully characterizing the sampling design in the experimental output of the multiple particle tracking technique, we derive estimators for the mean and variance of the probes’ dynamics that are independent of the peculiar statistical characteristics. We expose stringent tests of these estimators using simulated and experimental complex systems with a known heterogeneous structure. Up to a certain fundamental limitation, which we characterize through a material degree of sampling by the embedded probe tracking, these estimators can be applied to quantify the heterogeneity of a material, providing an original and intelligible kind of information on complex fluid properties. More generally, we show that the precise assessment of the statistics in the multiple particle tracking output sample of observations is essential in order to provide accurate unbiased measurements.
PET and PVC separation with hyperspectral imagery.

PubMed

Moroni, Monica; Mei, Alessandro; Leonardi, Alessandra; Lupo, Emanuela; Marca, Floriana La

2015-01-20

Traditional plants for plastic separation in homogeneous products employ material physical properties (for instance density). Due to the small intervals of variability of different polymer properties, the output quality may not be adequate. Sensing technologies based on hyperspectral imaging have been introduced in order to classify materials and to increase the quality of recycled products, which have to comply with specific standards determined by industrial applications. This paper presents the results of the characterization of two different plastic polymers--polyethylene terephthalate (PET) and polyvinyl chloride (PVC)--in different phases of their life cycle (primary raw materials, urban and urban-assimilated waste and secondary raw materials) to show the contribution of hyperspectral sensors in the field of material recycling. This is accomplished via near-infrared (900-1700 nm) reflectance spectra extracted from hyperspectral images acquired with a two-linear-spectrometer apparatus. Results have shown that a rapid and reliable identification of PET and PVC can be achieved by using a simple two near-infrared wavelength operator coupled to an analysis of reflectance spectra. This resulted in 100% classification accuracy. A sensor based on this identification method appears suitable and inexpensive to build and provides the necessary speed and performance required by the recycling industry.
PET and PVC Separation with Hyperspectral Imagery

PubMed Central

Moroni, Monica; Mei, Alessandro; Leonardi, Alessandra; Lupo, Emanuela; La Marca, Floriana

2015-01-01

Traditional plants for plastic separation in homogeneous products employ material physical properties (for instance density). Due to the small intervals of variability of different polymer properties, the output quality may not be adequate. Sensing technologies based on hyperspectral imaging have been introduced in order to classify materials and to increase the quality of recycled products, which have to comply with specific standards determined by industrial applications. This paper presents the results of the characterization of two different plastic polymers—polyethylene terephthalate (PET) and polyvinyl chloride (PVC)—in different phases of their life cycle (primary raw materials, urban and urban-assimilated waste and secondary raw materials) to show the contribution of hyperspectral sensors in the field of material recycling. This is accomplished via near-infrared (900–1700 nm) reflectance spectra extracted from hyperspectral images acquired with a two-linear-spectrometer apparatus. Results have shown that a rapid and reliable identification of PET and PVC can be achieved by using a simple two near-infrared wavelength operator coupled to an analysis of reflectance spectra. This resulted in 100% classification accuracy. A sensor based on this identification method appears suitable and inexpensive to build and provides the necessary speed and performance required by the recycling industry. PMID:25609050
Performance characterization of active fiber-composite actuators for helicopter rotor blade applications

NASA Astrophysics Data System (ADS)

Wickramasinghe, Viresh K.; Hagood, Nesbitt W.

2002-07-01

The primary objective of this work was to characterize the performance of the Active Fiber Composite (AFC) actuator material system for the Boeing Active Material Rotor (AMR) blade application. The AFCs were a new structural actuator system consisting of piezoceramic fibers embedded in an epoxy matrix and sandwiched between interdigitated electrodes to orient the driving electric field in the fiber direction to use the primary piezoelectric effect. These actuators were integrated directly into the blade spar laminate as active plies within the composite structure to perform structural actuation for vibration control in helicopters. Therefore, it was necessary to conduct extensive electromechanical material characterization to evaluate AFCs both as actuators and as structural components of the rotor blade. The characterization tests designed to extract important electromechanical properties under simulated blade operating conditions included stress-strain tests, free strain tests and actuation under tensile load tests. This paper presents the test results as well as the comprehensive testing process developed to evaluate the relevant AFC material properties. The results from this comprehensive performance characterization of the AFC material system supported the design and operation of the Boeing AMR blade scheduled for hover and forward flight wind tunnel tests.
The time dependence of rock healing as a universal relaxation process, a tutorial

NASA Astrophysics Data System (ADS)

Snieder, Roel; Sens-Schönfelder, Christoph; Wu, Renjie

2017-01-01

The material properties of earth materials often change after the material has been perturbed (slow dynamics). For example, the seismic velocity of subsurface materials changes after earthquakes, and granular materials compact after being shaken. Such relaxation processes are associated by observables that change logarithmically with time. Since the logarithm diverges for short and long times, the relaxation can, strictly speaking, not have a log-time dependence. We present a self-contained description of a relaxation function that consists of a superposition of decaying exponentials that has log-time behaviour for intermediate times, but converges to zero for long times, and is finite for t = 0. The relaxation function depends on two parameters, the minimum and maximum relaxation time. These parameters can, in principle, be extracted from the observed relaxation. As an example, we present a crude model of a fracture that is closing under an external stress. Although the fracture model violates some of the assumptions on which the relaxation function is based, it follows the relaxation function well. We provide qualitative arguments that the relaxation process, just like the Gutenberg-Richter law, is applicable to a wide range of systems and has universal properties.
Time And Temperature Dependent Micromechanical Properties Of Solder Joints For 3D-Package Integration

NASA Astrophysics Data System (ADS)

Roellig, Mike; Meier, Karsten; Metasch, Rene

2010-11-01

The recent development of 3D-integrated electronic packages is characterized by the need to increase the diversity of functions and to miniaturize. Currently many 3D-integration concepts are being developed and all of them demand new materials, new designs and new processing technologies. The combination of simulation and experimental investigation becomes increasingly accepted since simulations help to shorten the R&D cycle time and reduce costs. Numerical calculations like the Finite-Element-Method are strong tools to calculate stress conditions in electronic packages resulting from thermal strains due to the manufacturing process and environmental loads. It is essential for the application of numerical calculations that the material data is accurate and describes sufficiently the physical behaviour. The developed machine allows the measurement of time and temperature dependent micromechanical properties of solder joints. Solder joints, which are used to mechanically and electrically connect different packages, are physically measured as they leave the process. This allows accounting for process influences, which may change material properties. Additionally, joint sizes and metallurgical interactions between solder and under bump metallization can be respected by this particular measurement. The measurement allows the determination of material properties within a temperature range of 20° C-200° C. Further, the time dependent creep deformation can be measured within a strain-rate range of 10-31/s-10-81/s. Solder alloys based on Sn-Ag/Sn-Ag-Cu with additionally impurities and joint sizes down to O/ 200 μm were investigated. To finish the material characterization process the material model coefficient were extracted by FEM-Simulation to increase the accuracy of data.
Mechanical Characteristics, In Vitro Degradation, Cytotoxicity, and Antibacterial Evaluation of Zn-4.0Ag Alloy as a Biodegradable Material

PubMed Central

Li, Ping; Schille, Christine; Schweizer, Ernst; Rupp, Frank; Heiss, Alexander; Legner, Claudia; Klotz, Ulrich E.; Geis-Gerstorfer, Jürgen

2018-01-01

Zn-based biodegradable metallic materials have been regarded as new potential biomaterials for use as biodegradable implants, mainly because of the ideal degradation rate compared with those of Mg-based alloys and Fe-based alloys. In this study, we developed and investigated a novel Zn-4 wt % Ag alloy as a potential biodegradable metal. A thermomechanical treatment was applied to refine the microstructure and, consequently, to improve the mechanical properties, compared to pure Zn. The yield strength (YS), ultimate tensile strength (UTS) and elongation of the Zn-4Ag alloy are 157 MPa, 261 MPa, and 37%, respectively. The corrosion rate of Zn-4Ag calculated from released Zn ions in DMEM extracts is approximately 0.75 ± 0.16 μg cm–2 day–1, which is higher than that of pure Zn. In vitro cytotoxicity tests showed that the Zn-4Ag alloy exhibits acceptable toxicity to L929 and Saos-2 cells, and could effectively inhibit initial bacteria adhesion. This study shows that the Zn-4Ag exhibits excellent mechanical properties, predictable degradation behavior, acceptable biocompatibility, and effective antibacterial properties, which make it a candidate biodegradable material. PMID:29518938
Cubesat in-situ degradation detector (CIDD)

NASA Astrophysics Data System (ADS)

Rievers, Benny; Milke, Alexander; Salden, Daniel

2015-07-01

The design of the thermal control and management system (TCS) is a central task in satellite design. In order to evaluate and dimensionize the properties of the TCS, material parameters specifying the conductive and radiative properties of the different TCS components have to be known including their respective variations within the mission lifetime. In particular the thermo-optical properties of the outer surfaces including critical TCS components such as radiators and thermal insulation are subject to degradation caused by interaction with the space environment. The evaluation of these material parameters by means of ground testing is a time-consuming and expensive endeavor. Long-term in-situ measurements on board the ISS or large satellites not only realize a better implementation of the influence of the space environment but also imply high costs. Motivated by this we propose the utilization of low-cost nano-satellite systems to realize material tests within space at a considerably reduced cost. We present a nanosat-scale degradation sensor concept which realizes low power consumption and data rates compatible with nanosat boundaries at UHF radio. By means of a predefined measurement and messaging cycle temperature curves are measured and evaluated on ground to extract the change of absorptivity and emissivity over mission lifetime.
In vitro degradation and biocompatibility of Fe-Pd and Fe-Pt composites fabricated by spark plasma sintering.

PubMed

Huang, T; Cheng, J; Zheng, Y F

2014-02-01

In order to obtain biodegradable Fe-based materials with similar mechanical properties as 316L stainless steel and faster degradation rate than pure iron, Fe-5 wt.%Pd and Fe-5 wt.%Pt composites were prepared by spark plasma sintering with powders of pure Fe and Pd/Pt, respectively. The grain size of Fe-5 wt.%Pd and Fe-5 wt.%Pt composites was much smaller than that of as-cast pure iron. The metallic elements Pd and Pt were uniformly distributed in the matrix and the mechanical properties of these materials were improved. Uniform corrosion of Fe-Pd and Fe-Pt composites was observed in both electrochemical tests and immersion tests, and the degradation rates of Fe-Pd and Fe-Pt composites were much faster than that of pure iron. It was found that viabilities of mouse fibroblast L-929 cells and human umbilical vein endothelial cells (ECV304) cultured in extraction mediums of Fe-Pd and Fe-Pt composites were close to that of pure iron. After 4 days' culture, the viabilities of L-929 and ECV304 cells in extraction medium of experimental materials were about 80%. The result of direct contact cytotoxicity also indicated that experimental materials exhibited no inhibition on vascular endothelial process. Meanwhile, iron ions released from experimental materials could inhibit proliferation of vascular smooth muscle cells (VSMC), which may be beneficial for hindering vascular restenosis. Furthermore, compared with that of as-cast pure iron, the hemolysis rates of Fe-Pd and Fe-Pt composites were slightly higher, but still within the range of 5%, which is the criteria for good blood compatibility. The numbers of platelet adhered on the surface of Fe-Pd and Fe-Pt composites were lower than that of pure iron, and the morphology of platelets kept spherical. To sum up, the Fe-5 wt.%Pd and Fe-5 wt.%Pt composites exhibited good mechanical properties and degradation behavior, closely approaching the requirements for biodegradable metallic stents. © 2013.

Effect of solvent polarity on the extraction of components of pharmaceutical plastic containers.

PubMed

Ahmad, Iqbal; Sabah, Arif; Anwar, Zubair; Arif, Aysha; Arsalan, Adeel; Qadeer, Kiran

2017-01-01

A study of the extraction of polymeric material and dyes from the pharmaceutical plastic containers using various organic solvents was conducted to evaluate the effect of polarity on the extraction process. The plastic containers used included semi-opaque, opaque, transparent and amber colored and the solvent used were acetonitrile, methanol, ethanol, acetone, dichloroethane, chloroform and water. The determination of extractable material was carried out by gravimetric and spectrometric methods. The yield of extractable materials from containers in 60 h was 0.10-1.29% (w/w) and the first-order rate constant (kobs) for the extraction of polymeric material ranged from 0.52-1.50 × 10-3 min -1 and for the dyes 6.43- 6.74 x10-3min-1. The values of (k obs ) were found to be an inverse function of solvent dielectric constant and decreased linearly with the solvent acceptor number. The extractable polymeric materials exhibited absorption in the 200-400 nm region and the dyes in the 300-500nm region. The rates of extraction of polymeric material and dyes from plastic containers were dependent on the solvent dielectric constant. The solvents of low polarity were more effective in the extraction of material indicating that the extracted material were of low polarity or have non-polar character. The dyes were soluble in acetone and chloroform. No plastic material was found to be extracted from the containers in aqueous solution.
Comparative study on anti-oxidant and anti-inflammatory activities of Caesalpinia crista and Centella asiatica leaf extracts

PubMed Central

Ramesh, B. N.; Girish, T. K.; Raghavendra, R. H.; Naidu, K. Akhilender; Rao, U. J. S. Prasada; Rao, K. S.

2014-01-01

Background: Amyloidosis, oxidative stress and inflammation have been strongly implicated in neurodegenerative disorders like Alzheimer's disease. Traditionally, Caesalpinia crista and Centella asiatica leaf extracts are used to treat brain related diseases in India. C. crista is used as a mental relaxant drink as well as to treat inflammatory diseases, whereas C. asiatica is reported to be used to enhance memory and to treat dementia. Objective: The present study is aimed to understand the anti-oxidant and anti-inflammatory potential of C. asiatica and C. crista leaf extracts. Materials and Methods: Phenolic acid composition of the aqueous extracts of C. crista and C. asiatica were separated on a reverse phase C18 column (4.6 x 250 mm) using HPLC system. Antioxidant properties of the leaf extracts were determined by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay and the reducing potential assay. The anti-inflammatory activities of aqueous extracts of C. crista and C. asiatica were studied using 5-lipoxygenase assay. Polymorphonuclear leukocytes (PMNLs) were isolated from blood by Ficoll-Histopaque density gradient followed by hypotonic lysis of erythrocytes. Results: Gallic, protocatechuic, gentisic, chlorogenic, caffeic, p-coumaric and ferulic acids were the phenolic acids identified in C. crista and C. asiatica leaf aqueous extracts. However, gallic acid and ferulic acid contents were much higher in C. crista compared to C. asiatica. Leaf extracts of C. asiatica and C. crista exhibited antioxidant properties and inhibited 5-lipoxygenase (anti-inflammatory) in a dose dependent manner. However, leaf extracts of C. crista had better antioxidant and anti-inflammatory activity compared to that of C. asiatica. The better activity of C. crista is attributed to high gallic acid and ferulic acid compared to C. asiatica. Conclusions: Thus, the leaf extract of C. crista can be a potential therapeutic role for Alzheimer's disease. PMID:24741275
In-vitro investigation of anti-acne properties of Mangifera indica L. kernel extract and its mechanism of action against Propionibacterium acnes.

PubMed

Poomanee, Worrapan; Chaiyana, Wantida; Mueller, Monika; Viernstein, Helmut; Khunkitti, Watcharee; Leelapornpisid, Pimporn

2018-05-17

Propionibacterium acnes has been recognized as a main target for medical treatment of acne since this bacterium promotes acne inflammation by inducing upregulation of pro-inflammatory cytokines production, resulting in an accumulation of neutrophils and oxygen-free radicals produced by neutrophils within acne lesion. The aims of this study were to evaluate the biological activities of Mangifera indica kernel extracts grown in Northern Thailand (Kaew-Moragot cultivar), related to anti-acne properties including antimicrobial effect against acne-inducing bacteria together with the first elucidation of the mechanism of action against Propionibacterium acnes, anti-oxidation, and anti-inflammation. The kernels of M. indica, obtained from raw and ripe fruits, were macerated using various solvents. Agar diffusion and broth microdilution methods were performed to investigate the antibacterial activities of the extracts against P. acnes, Staphylococcus aureus, and Staphylococcus epidermidis. The ethanolic fractions exhibited the strongest antimicrobial effect against P. acnes with minimum inhibitory concentration and minimum bactericidal concentration of 1.56 mg/mL and 12.50 mg/mL, respectively. Bactericidal effect against P. acnes of these extracts could be observed after 3 h of incubation from time-kill curve. The chromatograms of high-performance liquid chromatography showed that the extracts existed gallic acid with high total phenolic content. These extracts additionally showed strong free radical scavenging properties on 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) as well as a notable inhibitory effect on linoleic acid peroxidation, which highly correlated to their antimicrobial effect, total phenolic, and gallic acid contents. The images, studied through using transmission electron microscopy, revealed that the extract certainly disrupted P. acnes cell membrane after exposure for 1 h as well as induced the consequent leakage of cytoplasmic materials. The inhibitory effects of the extracts on IL-8 secretion from LPS-inducing RAW 264.7 cells were also presented. In conclusion, the kernel extracts of raw M. indica fruit were effective against aerobic and anaerobic acne-inducing bacteria particularly P. acnes and exerted antioxidant along with anti-inflammatory activities. Therefore, the extracts might be potential agents for inflammatory acne treatment. However, clinical study is needed for further investigation. Copyright © 2018 Elsevier Ltd. All rights reserved.
Effects of different extraction methods on total phenolic content and antioxidant activity in soybean cultivars

NASA Astrophysics Data System (ADS)

Yusnawan, E.

2018-01-01

Soybean secondary metabolites particularly phenolic compounds act as chemical defence against biotic stress such as pathogen infection. Functional properties of these compounds have also been investigated. This study aimed to determine the effects of particle size and extraction methods on total flavonoid, phenolic contents as well as antioxidant activity in soybean seeds. This study also investigated the total phenolic contents and antioxidant activity of Indonesian soybean cultivars using the optimized extraction method. Soybean flour of ≤ 177 μm as many as 0.5 g was selected for extraction with 50% acetone for estimation of total phenolic and flavonoid contents and with 80% ethanol for antioxidant activity. Treatments of twice extraction either shaking followed by maceration or ultrasound-assisted extraction followed by maceration could be used to extract the secondary metabolite contents in soybean seeds. Flavonoid, phenolic contents and antioxidant activity of twenty soybean cultivars ranged from 0.23 to 0.44 mg CE/g, from 3.70 to 5.22 mg GAE/g, and from 4.97 to 9.04 µmol TE/g, respectively. A simple extraction with small amount of soybean flour such as investigated in this present study is effective to extract secondary metabolites especially when the availability of samples is limited such as breeding materials or soybean germplasm.
Microscale Characterization of the Viscoelastic Properties of Hydrogel Biomaterials using Dual-Mode Ultrasound Elastography

PubMed Central

Hong, Xiaowei; Stegemann, Jan P.; Deng, Cheri X.

2016-01-01

Characterization of the microscale mechanical properties of biomaterials is a key challenge in the field of mechanobiology. Dual-mode ultrasound elastography (DUE) uses high frequency focused ultrasound to induce compression in a sample, combined with interleaved ultrasound imaging to measure the resulting deformation. This technique can be used to non-invasively perform creep testing on hydrogel biomaterials to characterize their viscoelastic properties. DUE was applied to a range of hydrogel constructs consisting of either hydroxyapatite (HA)-doped agarose, HA-collagen, HA-fibrin, or preosteoblast-seeded collagen constructs. DUE provided spatial and temporal mapping of local and bulk displacements and strains at high resolution. Hydrogel materials exhibited characteristic creep behavior, and the maximum strain and residual strain were both material- and concentration-dependent. Burger’s viscoelastic model was used to extract characteristic parameters describing material behavior. Increased protein concentration resulted in greater stiffness and viscosity, but did not affect the viscoelastic time constant of acellular constructs. Collagen constructs exhibited significantly higher modulus and viscosity than fibrin constructs. Cell-seeded collagen constructs became stiffer with altered mechanical behavior as they developed over time. Importantly, DUE also provides insight into the spatial variation of viscoelastic properties at sub-millimeter resolution, allowing interrogation of the interior of constructs. DUE presents a novel technique for non-invasively characterizing hydrogel materials at the microscale, and therefore may have unique utility in the study of mechanobiology and the characterization of hydrogel biomaterials. PMID:26928595
Microscale characterization of the viscoelastic properties of hydrogel biomaterials using dual-mode ultrasound elastography.

PubMed

Hong, Xiaowei; Stegemann, Jan P; Deng, Cheri X

2016-05-01

Characterization of the microscale mechanical properties of biomaterials is a key challenge in the field of mechanobiology. Dual-mode ultrasound elastography (DUE) uses high frequency focused ultrasound to induce compression in a sample, combined with interleaved ultrasound imaging to measure the resulting deformation. This technique can be used to non-invasively perform creep testing on hydrogel biomaterials to characterize their viscoelastic properties. DUE was applied to a range of hydrogel constructs consisting of either hydroxyapatite (HA)-doped agarose, HA-collagen, HA-fibrin, or preosteoblast-seeded collagen constructs. DUE provided spatial and temporal mapping of local and bulk displacements and strains at high resolution. Hydrogel materials exhibited characteristic creep behavior, and the maximum strain and residual strain were both material- and concentration-dependent. Burger's viscoelastic model was used to extract characteristic parameters describing material behavior. Increased protein concentration resulted in greater stiffness and viscosity, but did not affect the viscoelastic time constant of acellular constructs. Collagen constructs exhibited significantly higher modulus and viscosity than fibrin constructs. Cell-seeded collagen constructs became stiffer with altered mechanical behavior as they developed over time. Importantly, DUE also provides insight into the spatial variation of viscoelastic properties at sub-millimeter resolution, allowing interrogation of the interior of constructs. DUE presents a novel technique for non-invasively characterizing hydrogel materials at the microscale, and therefore may have unique utility in the study of mechanobiology and the characterization of hydrogel biomaterials. Copyright © 2016 Elsevier Ltd. All rights reserved.
Structural and Chemical Properties of the Nitrogen-Rich Energetic Material Triaminoguanidinium 1-methyl-5-nitriminotetrazolate under Pressure

DTIC Science & Technology

2012-08-01

Source (NSLS) of Brookhaven National Laboratory ( BNL ). The syn- chrotron light is extracted from the VUV storage ring in a 40 × 40 mrad solid angle and...Contract No. DE-AC02-06CH11357. Infrared mea- surements were performed at the U2A beamline at the NSLS of BNL (DOE Contract No. DE-AC02-98CH10886). The
Dataset demonstrating effects of momentum transfer on sizing of current collector for lithium-ion batteries during laser cutting.

PubMed

Lee, Dongkyoung; Mazumder, Jyotirmoy

2018-04-01

Material properties of copper and aluminum required for the numerical simulation are presented. Electrodes used for the (paper) are depicted. This study describes the procedures of how penetration depth, width, and absorptivity are obtained from the simulation. In addition, a file format extracted from the simulation to visualize 3D distribution of temperature, velocity, and melt pool geometry is presented.
Ultrasonic real-time in-die monitoring of the tablet compaction process-a proof of concept study.

PubMed

Stephens, James D; Kowalczyk, Brian R; Hancock, Bruno C; Kaul, Goldi; Cetinkaya, Cetin

2013-02-14

The mechanical properties of a drug tablet can affect its performance (e.g., dissolution profile and its physical robustness. An ultrasonic system for real-time in-die tablet mechanical property monitoring during compaction has been demonstrated. The reported set-up is a proof of concept compaction monitoring system which includes an ultrasonic transducer mounted inside the upper punch of the compaction apparatus. This upper punch is utilized to acquire ultrasonic pressure wave phase velocity waveforms and extract the time-of-flight of pressure waves travelling within the compact at a number of compaction force levels during compaction. The reflection coefficients for the waves reflecting from punch tip-powder bed interface are extracted from the acquired waveforms. The reflection coefficient decreases with an increase in compaction force, indicating solidification. The data acquisition methods give an average apparent Young's moduli in the range of 8-20 GPa extracted during the compaction and release/decompression phases in real-time. A monitoring system employing such methods is capable of determining material properties and the integrity of the tablet during compaction. As compared to the millisecond time-scale dwell time of a typical commercial compaction press, the micro-second pulse duration and ToF of an acoustic pulse are sufficiently fast for real-time monitoring. Copyright © 2012 Elsevier B.V. All rights reserved.
Characterisation of metals in the electronic waste of complex mixtures of end-of-life ICT products for development of cleaner recovery technology.

PubMed

Sun, Z H I; Xiao, Y; Sietsma, J; Agterhuis, H; Visser, G; Yang, Y

2015-01-01

Recycling of valuable metals from electronic waste, especially complex mixtures of end-of-life information and communication technology (ICT) products, is of great difficulty due to their complexity and heterogeneity. One of the important reasons is the lack of comprehensive characterisation on such materials, i.e. accurate compositions, physical/chemical properties. In the present research, we focus on developing methodologies for the characterisation of metals in an industrially processed ICT waste. The morphology, particle size distribution, compositional distribution, occurrence, liberation as well as the thermo-chemical properties of the ICT waste were investigated with various characterisation techniques, including X-ray Fluorescence Spectrometry (XRF), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM) with energy dispersed spectroscopy (EDS). Due to the high heterogeneity of the material, special sample preparation procedures were introduced to minimise the discrepancies during compositional analyses. As a result, a clearer overview of the ICT waste has been reached. This research provides better understanding of the extractability of each metal and improves the awareness of potential obstacles for extraction. It will lead to smarter decisions during further development of a clean and effective recovery process. Copyright © 2014 Elsevier Ltd. All rights reserved.
Antidiabetic, hypolipidemic and hepatoprotective effects of Arctium lappa root’s hydro-alcoholic extract on nicotinamide-streptozotocin induced type 2 model of diabetes in male mice

PubMed Central

Ahangarpour, Akram; Heidari, Hamid; Oroojan, Ali Akbar; Mirzavandi, Farhang; Nasr Esfehani, Khalil; Dehghan Mohammadi, Zeinab

2017-01-01

Objective: Arctium lappa (burdock), (A. lappa) root has hypoglycemic and antioxidative effects, and has been used for treatment of diabetes in tradition medicine. This study was conducted to evaluate the antidiabetic and hypolipidemic properties of A. lappa root extract on nicotinamide-streptozotocin (NA-STZ)-induced type2 diabetes in mice. Materials and Methods: In this investigation, 70 adult male NMRI mice (30-35g) randomly divided into 7 groups (n=10) as follow: 1-control, 2-type 2 diabetic mice, 3-diabetic mice that received glibenclamide (0.25 mg/kg) as an anti-diabetic drug, 4, 5, 6 and 7- diabetic and normal animals that were pre-treated with 200 and 300 mg/kg A. lappa root extract, respectively, for 28 days. Diabetes has been induced by intraperitoneal injection of NA and STZ. Finally, the blood sample was taken and insulin, glucose, SGOT, SGPT, alkaline phosphatase, leptin and lipid levels was evaluated. Results: Induction of diabetes decreased the level of insulin, leptin and high density lipoprotein (HDL) and increased the level of other lipids, glucose, and hepatic enzymes significantly (p<0.05). Administration of both doses of the extract significantly decreased the level of triglyceride, very low density lipoprotein, glucose and alkaline phosphatase in diabetic mice (p<0.05). Insulin levels increased in animals treated with 200 mg/kg (p<0.05) and HDL and leptin levels increased in animals treated with 300 mg/kg of the extract (p<0.01). Conclusion: The results showed that A. lappa root extract, at specific doses, has an anti-diabetic effect through its hypolipidemic and insulinotropic properties. Hence, this plant extract may be beneficial in the treatment of diabetes. PMID:28348972
Blending Education and Polymer Science: Semi Automated Creation of a Thermodynamic Property Database.

PubMed

Tchoua, Roselyne B; Qin, Jian; Audus, Debra J; Chard, Kyle; Foster, Ian T; de Pablo, Juan

2016-09-13

Structured databases of chemical and physical properties play a central role in the everyday research activities of scientists and engineers. In materials science, researchers and engineers turn to these databases to quickly query, compare, and aggregate various properties, thereby allowing for the development or application of new materials. The vast majority of these databases have been generated manually, through decades of labor-intensive harvesting of information from the literature; yet, while there are many examples of commonly used databases, a significant number of important properties remain locked within the tables, figures, and text of publications. The question addressed in our work is whether, and to what extent, the process of data collection can be automated. Students of the physical sciences and engineering are often confronted with the challenge of finding and applying property data from the literature, and a central aspect of their education is to develop the critical skills needed to identify such data and discern their meaning or validity. To address shortcomings associated with automated information extraction, while simultaneously preparing the next generation of scientists for their future endeavors, we developed a novel course-based approach in which students develop skills in polymer chemistry and physics and apply their knowledge by assisting with the semi-automated creation of a thermodynamic property database.
Blending Education and Polymer Science: Semiautomated Creation of a Thermodynamic Property Database

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tchoua, Roselyne B.; Qin, Jian; Audus, Debra J.

Structured databases of chemical and physical properties play a central role in the everyday research activities of scientists and engineers. In materials science, researchers and engineers turn to these databases to quickly query, compare, and aggregate various properties, thereby allowing for the development or application of new materials. The vast majority of these databases have been generated manually, through decades of labor-intensive harvesting of information from the literature, yet while there are many examples of commonly used databases, a significant number of important properties remain locked within the tables, figures, and text of publications. The question addressed in our workmore » is whether and to what extent the process of data collection can be automated. Students of the physical sciences and engineering are often confronted with the challenge of finding and applying property data from the literature, and a central aspect of their education is to develop the critical skills needed to identify such data and discern their meaning or validity. To address shortcomings associated with automated information extraction while simultaneously preparing the next generation of scientists for their future endeavors, we developed a novel course-based approach in which students develop skills in polymer chemistry and physics and apply their knowledge by assisting with the semiautomated creation of a thermodynamic property database.« less
Antibacterial, mechanical, and barrier properties of sago starch film incorporated with Betel leaves extract.

PubMed

Nouri, Leila; Mohammadi Nafchi, Abdorreza

2014-05-01

The antimicrobial, mechanical and barrier properties and light transmission of sago starch film incorporated with different percentage of Betel leaf extract (5%, 10%, 20%, and 30%) were evaluated. With regard to mechanical properties, tensile strength decreased when the percentage of extract increased. Elongation at break (%) and seal strength (N/m) increased with increasing percentage of extract from 5% to 20%, while decreased for films containing 30% extract due to heterogeneity of films in this percentage. With regard to barrier properties, water vapour and oxygen barrier properties decreased in all samples when percentage of the extract increased. Antimicrobial activity of all the films increased against both Gram positive and Gram negative bacteria as percentage of Betel leaf extract increased, except for Psuedomonas aeruginosa, which was not susceptible at any percentage of the extract. Copyright © 2014 Elsevier B.V. All rights reserved.
Isolation of atropine and scopolamine from plant material using liquid-liquid extraction and EXtrelut® columns.

PubMed

Śramska, Paula; Maciejka, Artur; Topolewska, Anna; Stepnowski, Piotr; Haliński, Łukasz P

2017-02-01

Tropane alkaloids are toxic secondary metabolites produced by Solanaceae plants. Among them, plants from Datura genus produce significant amounts of scopolamine and hyoscyamine; the latter undergoes racemization to atropine during isolation. Because of their biological importance, toxic properties and commonly reported food and animal feed contamination by different Datura sp. organs, there is a constant need for reliable methods for the analysis of tropane alkaloids in many matrices. In the current study, three extraction and sample-clean up procedures for the determination of scopolamine and atropine in plant material were compared in terms of their effectiveness and repeatability. Standard liquid-liquid extraction (LLE) and EXtrelut ® NT 3 columns were used for the sample clean-up. Combined ultrasound-assisted extraction and 24h static extraction using ethyl acetate, followed by multiple LLE steps was found the most effective separation method among tested. However, absolute extraction recovery was relatively low and reached 45-67% for atropine and 52-73% for scopolamine, depending on the compound concentration. The same method was also the most effective one for the isolation of target compounds from Datura stramonium leaves. EXtrelut ® columns, on the other hand, displayed relatively low effectiveness in isolating atropine and scopolamine from such a complex matrix and hence could not be recommended. The most effective method was also applied to the extraction of alkaloids from roots and stems of D. stramonium. Quantitative analyses were performed using validated method based on gas chromatography with flame ionization detector (GC-FID). Based on the results, the importance of the proper selection of internal standards in the analysis of tropane alkaloids was stressed out. Copyright © 2016 Elsevier B.V. All rights reserved.
The effect of Artemisia annua on broiler performance, on intestinal microbiota and on the course of a Clostridium perfringens infection applying a necrotic enteritis disease model.

PubMed

Engberg, Ricarda Margarete; Grevsen, Kai; Ivarsen, Elise; Fretté, Xavier; Christensen, Lars Porskjær; Højberg, Ole; Jensen, Bent Borg; Canibe, Nuria

2012-01-01

The aerial parts of the plant Artemisia annua contain essential oils having antimicrobial properties against Clostridium perfringens Type A, the causal agent for necrotic enteritis in broilers. In two experiments, the influence of increasing dietary concentrations of dried A. annua leaves (0, 5, 10 and 20 g/kg) and n-hexane extract from fresh A. annua leaves (0, 125, 250 and 500 mg/kg) on broiler performance was investigated. Dried plant material decreased feed intake and body weight in a dose-dependent manner, and 10 and 20 g/kg diet tended to improve the feed conversion ratio. The n-hexane extract also reduced feed intake, but broiler weight tended to decrease only at the highest dietary concentration. The feed conversion ratio tended to improve when birds received 250 and 500 mg/kg n-hexane extract. In a third experiment, a necrotic enteritis disease model was applied to investigate the effect of the dietary addition of dried A. annua leaves (10 g/kg on top) or n-hexane extract of A. annua (250 mg/kg) on the severity of the disease in broilers. The addition of n-hexane extract reduced the intestinal C. perfringens numbers and the severity of the disease-related small intestinal lesions. Over the infection period from day 17 to day 27, birds supplemented with the n-hexane extract gained more weight than both the challenged control birds and birds receiving dried plant material. The results indicate that n-hexane extracts derived from A. annua can modulate the course of necrotic enteritis and compensate to a certain extent for the disease-associated weight losses.
Antimicrobial activity of Anonna mucosa (Jacq.) grown in vivo and obtained by in vitroculture.

PubMed

Barboza, Thiago José de Souza; Ferreira, Andréa Fonseca; Ignacio, Ana Claudia de Paula Rosa; Albarello, Norma

2015-01-01

Brazilian flora includes numerous species of medicinal importance that can be used to develop new drugs. Plant tissue culture offers strategies for conservation and use of these species allowing continuous production of plants and bioactive substances. Annona mucosa has produced substances such as acetogenins and alkaloids that exhibit antimicrobial activities. The widespread use of antibiotics has led to an increase in multidrug-resistant bacteria, which represents a serious risk of infection. In view of this problem, the aim of this work was to evaluate the antibacterial potential of extracts of A. mucosa obtained by in vitro techniques and also cultured under in vivo conditions. Segments from seedlings were inoculated onto different culture media containing the auxin picloram and the cytokinin kinetin at different concentrations. The calluses obtained were used to produce cell suspension cultures. The materials were subjected to methanol extraction and subsequent fractionation in hexane and dichloromethane. The antimicrobial activity against 20 strains of clinical relevance was evaluated by the macrodilution method at minimum inhibitory and minimum bactericidal concentrations. The extracts showed selective antimicrobial activity, inhibiting the growth of Streptococcus pyogenes and Bacillus thuringiensis at different concentrations. The plant tissue culture methods produced plant materials with antibacterial properties, as well as in vivo grown plants. The antibacterial activity of material obtained through biotechnological procedures of A. mucosa is reported here for the first time.
Antimicrobial activity of Anonna mucosa (Jacq.) grown in vivo and obtained by in vitroculture

PubMed Central

de Souza Barboza, Thiago José; Ferreira, Andréa Fonseca; de Paula Rosa Ignacio, Ana Claudia; Albarello, Norma

2015-01-01

Brazilian flora includes numerous species of medicinal importance that can be used to develop new drugs. Plant tissue culture offers strategies for conservation and use of these species allowing continuous production of plants and bioactive substances. Annona mucosa has produced substances such as acetogenins and alkaloids that exhibit antimicrobial activities. The widespread use of antibiotics has led to an increase in multidrug-resistant bacteria, which represents a serious risk of infection. In view of this problem, the aim of this work was to evaluate the antibacterial potential of extracts of A. mucosa obtained by in vitro techniques and also cultured under in vivo conditions. Segments from seedlings were inoculated onto different culture media containing the auxin picloram and the cytokinin kinetin at different concentrations. The calluses obtained were used to produce cell suspension cultures. The materials were subjected to methanol extraction and subsequent fractionation in hexane and dichloromethane. The antimicrobial activity against 20 strains of clinical relevance was evaluated by the macrodilution method at minimum inhibitory and minimum bactericidal concentrations. The extracts showed selective antimicrobial activity, inhibiting the growth of Streptococcus pyogenes and Bacillus thuringiensis at different concentrations. The plant tissue culture methods produced plant materials with antibacterial properties, as well as in vivo grown plants. The antibacterial activity of material obtained through biotechnological procedures of A. mucosa is reported here for the first time. PMID:26413061
Industrially synthesized single-walled carbon nanotubes: compositional data for users, environmental risk assessments, and source apportionment

NASA Astrophysics Data System (ADS)

Plata, D. L.; Gschwend, P. M.; Reddy, C. M.

2008-05-01

Commercially available single-walled carbon nanotubes (SWCNTs) contain large percentages of metal and carbonaceous impurities. These fractions influence the SWCNT physical properties and performance, yet their chemical compositions are not well defined. This lack of information also precludes accurate environmental risk assessments for specific SWCNT stocks, which emerging local legislation requires of nanomaterial manufacturers. To address these needs, we measured the elemental, molecular, and stable carbon isotope compositions of commercially available SWCNTs. As expected, catalytic metals occurred at per cent levels (1.3-29%), but purified materials also contained unexpected metals (e.g., Cu, Pb at 0.1-0.3 ppt). Nitrogen contents (up to 0.48%) were typically greater in arc-produced SWCNTs than in those derived from chemical vapor deposition. Toluene-extractable materials contributed less than 5% of the total mass of the SWCNTs. Internal standard losses during dichloromethane extractions suggested that metals are available for reductive dehalogenation reactions, ultimately resulting in the degradation of aromatic internal standards. The carbon isotope content of the extracted material suggested that SWCNTs acquired much of their carbonaceous contamination from their storage environment. Some of the SWCNTs, themselves, were highly depleted in 13C relative to petroleum-derived chemicals. The distinct carbon isotopic signatures and unique metal 'fingerprints' may be useful as environmental tracers allowing assessment of SWCNT sources to the environment.
Analyzing the impacts of three types of biochar on soil carbon fractions and physiochemical properties in a corn-soybean rotation.

PubMed

Sandhu, Saroop S; Ussiri, David A N; Kumar, Sandeep; Chintala, Rajesh; Papiernik, Sharon K; Malo, Douglas D; Schumacher, Thomas E

2017-10-01

Biochar is a solid material obtained when biomass is thermochemically converted in an oxygen-limited environment. In most previous studies, the impacts of biochar on soil properties and organic carbon (C) were investigated under controlled conditions, mainly laboratory incubation or greenhouse studies. This 2-year field study was conducted to evaluate the influence of biochar on selected soil physical and chemical properties and carbon and nitrogen fractions for two selected soil types (clay loam and a sandy loam soil) under a corn (Zea mays L.)-soybean (Glycine max L.) rotation. The three plant based biochar materials used for this study were corn stover (CS), ponderosa pine (Pinus ponderosa Lawson and C. Lawson) wood residue (PW), and switchgrass (Panicum virgatum L.) (SG). Data showed that CS and SG significantly increased the pH of acidic soil at the eroded landscape position but produced no significant change in soil pH at the depositional landscape position. The effects of biochar treatments on cold water extractable C (WSC) and nitrogen (WSN) fractions for the 0-7.5 cm depth were depended on biochar and soil type. Results suggested that alkaline biochars applied at 10 Mg ha -1 can increase the pH and WSC fraction of acidic sandy loam soil, but the 10 Mg ha -1 rate might be low to substantially improve physical properties and hot water extractable C and N fractions of soil. Application of higher rates of biochar and long-term monitoring is needed to quantify the benefits of biochar under field conditions on soils in different environmental conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Material characterization of active fiber composites for integral twist-actuated rotor blade application

NASA Astrophysics Data System (ADS)

Wickramasinghe, Viresh K.; Hagood, Nesbitt W.

2004-10-01

The primary objective of this work was to perform material characterization of the active fiber composite (AFC) actuator system for the Boeing active material rotor (AMR) blade application. The purpose of the AMR was to demonstrate active vibration control in helicopters through integral twist-actuation of the blade. The AFCs were a new structural actuator system consisting of piezoceramic fibers embedded in an epoxy matrix and sandwiched between interdigitated electrodes to enhance actuation performance. These conformable actuators were integrated directly into the blade spar laminate as active plies within the composite structure to perform structural control. Therefore, extensive electromechanical material characterization was required to evaluate AFCs both as actuators and as structural components of the blade. The characterization tests designed to extract important electromechanical properties under simulated blade operating conditions included nominal actuation tests, stress-strain tests and actuation under tensile load tests. This paper presents the test results as well as the comprehensive testing procedure developed to evaluate the relevant properties of the AFCs for structural application. The material characterization tests provided an invaluable insight into the behavior of the AFCs under various electromechanical conditions. The results from this comprehensive material characterization of the AFC actuator system supported the design and operation of the AMR blades scheduled for wind tunnel tests.
Antidiabetic activities of aqueous ethanol and n-butanol fraction of Moringa stenopetala leaves in streptozotocin-induced diabetic rats.

PubMed

Toma, Alemayehu; Makonnen, Eyasu; Mekonnen, Yelamtsehay; Debella, Asfaw; Adisakwattana, Sirichai

2015-07-18

Moringa stenopetala has been used in traditional health systems to treat diabetes mellitus. The aim of this study was to investigate the antidiabetic activity of aqueous ethanol and n-butanol fraction of Moringa stenopetala leaves in streptozotocin (STZ) induced diabetic rats. The aqueous ethanol extract and n-butanol fraction of Moringa stenopetala leaves hydroalcoholic (500 mg/kg body weight) and metformin (150 mg/kg body weight) were administered to diabetic rats. Blood glucose, lipid profiles, liver and kidney function were examined after 14 days of experiment. Histopathological profile of the pancreas was also observed in diabetic rats at the end of study. An oral sucrose challenge test was also carried out to assess the post prandial effect of the extract. Oral administration of the aqueous ethanol and n-butanol extracts of Moringa stenopetala leaves (500 mg/kg body weight) and metformin (150 mg/kg) significantly reduced blood glucose level (P<0.05), improved serum lipid profiles, liver enzymes and kidney functions in diabetic rats after 14 days. The extracts also improved damage of islet of Langerhan's in diabetic rats. The plant material reduced the post-prandial glucose level (P<0.001) at the dose of 750 mg/kg. These findings revealed that both the aqueous ethanol and n-butanol extracts of Moringa stenopetala leaves possess antihyperglycemic and antihyperlipidemic properties, and alleviate STZ-induced pancreatic damage in diabetic rats. The beneficial effects of plant material in inhibition of diabetes-induced complications are being investigated.
Rapid determination of 54 pharmaceutical and personal care products in fish samples using microwave-assisted extraction-Hollow fiber-Liquid/solid phase microextraction.

PubMed

Zhang, Yi; Guo, Wen; Yue, Zhenfeng; Lin, Li; Zhao, Fengjuan; Chen, Peijin; Wu, Weidong; Zhu, Hong; Yang, Bo; Kuang, Yanyun; Wang, Jiong

2017-04-15

In this paper, a simple, rapid, solvent-less and environmental friendliness microextraction method, microwave-assisted extraction-hollow fiber-liquid/solid phase microextraction (MAE-HF-L/SME), was developed for simultaneous extraction and enrichment of 54 trace hydrophilic/lipophilic pharmaceutical and personal care products (PPCPs) from fish samples. A solid-phase extraction material, solid-phase microextraction (SPME) fiber, was synthesized. The SPME fiber had a homogeneous, loose structure and good mechanical properties, and they exhibited a good adsorption capacity for most PPCPs selected. The material formed the basis for the method of MAE-HF-L/SME. A method of liquid chromatography-high resolution mass spectroscopy (LC-HRMS) for analysis of 54 PPCPs. Under optimal synthesis and extraction conditions, the limits of detection (LODs, n=3) and the limits of quantitation (LOQs, n=10) for the 54 PPCPs were between 0.01-0.50μg·kg -1 and 0.052.00μg·kg -1 , respectively. Percent recoveries and the relative standard deviations (RSDs) in spiked fish samples (n=6) were between 56.3%-119.9% and 0.3%-17.1%, respectively. The microextraction process of 54 PPCPs in MAE-HF-L/SME took approximately 12min. The method has a low matrix interference and high enrichment factor and may be applicable for determination of 54 different PPCPs in fish samples. Copyright © 2017 Elsevier B.V. All rights reserved.
An in silico framework to analyze the anisotropic shear wave mechanics in cardiac shear wave elastography

NASA Astrophysics Data System (ADS)

Caenen, Annette; Pernot, Mathieu; Peirlinck, Mathias; Mertens, Luc; Swillens, Abigail; Segers, Patrick

2018-04-01

Shear wave elastography (SWE) is a potential tool to non-invasively assess cardiac muscle stiffness. This study focused on the effect of the orthotropic material properties and mechanical loading on the performance of cardiac SWE, as it is known that these factors contribute to complex 3D anisotropic shear wave propagation. To investigate the specific impact of these complexities, we constructed a finite element model with an orthotropic material law subjected to different uniaxial stretches to simulate SWE in the stressed cardiac wall. Group and phase speed were analyzed in function of tissue thickness and virtual probe rotation angle. Tissue stretching increased the group and phase speed of the simulated shear wave, especially in the direction of the muscle fiber. As the model provided access to the true fiber orientation and material properties, we assessed the accuracy of two fiber orientation extraction methods based on SWE. We found a higher accuracy (but lower robustness) when extracting fiber orientations based on the location of maximal shear wave speed instead of the angle of the major axis of the ellipsoidal group speed surface. Both methods had a comparable performance for the center region of the cardiac wall, and performed less well towards the edges. Lastly, we also assessed the (theoretical) impact of pathology on shear wave physics and characterization in the model. It was found that SWE was able to detect changes in fiber orientation and material characteristics, potentially associated with cardiac pathologies such as myocardial fibrosis. Furthermore, the model showed clearly altered shear wave patterns for the fibrotic myocardium compared to the healthy myocardium, which forms an initial but promising outcome of this modeling study.
Comparison of the milk-clotting properties of three plant extracts.

PubMed

Mazorra-Manzano, Miguel A; Perea-Gutiérrez, Teresa C; Lugo-Sánchez, María E; Ramirez-Suarez, Juan C; Torres-Llanez, María J; González-Córdova, Aarón F; Vallejo-Cordoba, Belinda

2013-12-01

Several proteases from plant sources have been proposed as milk coagulants, however, limited research has been done on their milk-clotting properties. The effect of temperature on the milk-clotting activity of kiwi fruit, melon and ginger extracts was evaluated, as well as the effects of the different extracts on curd properties. Melon extracts showed high milk-clotting activity over a broad temperature range (45-75 °C) while kiwi fruit and ginger extracts showed high activity over a narrower temperature range, with a maximum at 40 and 63 °C, respectively. Curds produced using kiwi extracts had textural properties comparable with those obtained using commercial rennet, while melon extracts produced a fragile gel and low curd yield. The milk-clotting behavior of the three plant extracts was related to the protease specificity present in these extracts. The kiwi proteases displayed chymosin-like properties and thus hold the best potential for use as a milk coagulant in cheese production. Copyright © 2013 Elsevier Ltd. All rights reserved.
Bio-Oil Hydrotreatment for Enhancing Solubility in Biodiesel and the Oxydation Stability of Resulting Blends.

PubMed

Botella, Lucía; Stankovikj, Filip; Sánchez, José L; Gonzalo, Alberto; Arauzo, Jesús; Garcia-Pérez, Manuel

2018-01-01

The major challenge for the pyrolytic conversion of lignocellulosic materials into crude bio-oil is the poor quality of the final product. Several strategies (addition of solvents, production of emulsions, and extraction with biodiesel) have been studied to improve its fuel properties. The extraction with biodiesel is an interesting solution because it allows direct utilization of some bio-oil fractions as fuels. However, fraction extracted with biodiesel is typically between 10 and 18 wt. %. In this paper we studied mild hydrotreatment of pyrolysis oil to enhance its solubility in biodiesel. The study was conducted with BTG and Amaron oils hydrotreated at temperatures between 200 and 325°C in the presence of Ru/C catalyst. Hydrotreated oils generated three phases: top oil (light hydrocarbons), middle aqueous phase and bottom heavy oil phase. Each of the phases was characterized and the content of acetic acid, phenols, aromatic compounds, and linear alkane hydrocarbons quantified. The upgraded bio-oils were more soluble in biodiesel than the crude bio-oils, obtaining blends with up to 48 and 38 wt. % for the BTG and Amaron bio-oil, respectively. Some of the fuel properties of the resulting blends are also reported here.
Bio-oil Hydrotreatment for Enhancing Solubility in Biodiesel and the Oxydation Stability of Resulting Blends

NASA Astrophysics Data System (ADS)

Botella, Lucía; Stankovikj, Filip; Sánchez, José L.; Gonzalo, Alberto; Arauzo, Jesús; Garcia-Pérez, Manuel

2018-04-01

The major challenge for the pyrolytic conversion of lignocellulosic materials into crude bio-oil is the poor quality of the final product. Several strategies (addition of solvents, production of emulsions, and extraction with biodiesel) have been studied to improve its fuel properties. The extraction with biodiesel is an interesting solution because it allows direct utilization of some bio-oil fractions as fuels. However, fraction extracted with biodiesel is typically between 10 and 18 wt. %. In this paper we studied mild hydrotreatment of pyrolysis oil to enhance its solubility in biodiesel. The study was conducted with BTG and Amaron oils hydrotreated at temperatures between 200 and 325 °C in the presence of Ru/C catalyst. Hydrotreated oils generated three phases: top oil (light hydrocarbons), middle aqueous phase and bottom heavy oil phase. Each of the phases was characterized and the content of acetic acid, phenols, aromatic compounds and linear alkane hydrocarbons quantified. The upgraded bio-oils were more soluble in biodiesel than the crude bio-oils, obtaining blends with up to 48 and 38 wt. % for the BTG and Amaron bio-oil, respectively. Some of the fuel properties of the resulting blends are also reported here.
The chemical phenol extraction of intermetallic particles from casting AlSi5Cu1Mg alloy.

PubMed

Mrówka-Nowotnik, G; Sieniawski, J; Nowotnik, A

2010-03-01

This paper presents a chemical extraction technique for determination of intermetallic phases formed in the casting AlSi5Cu1Mg aluminium alloy. Commercial aluminium alloys contain a wide range of intermetallic particles that are formed during casting, homogenization and thermomechanical processing. During solidification, particles of intermetallics are dispersed in interdendritic spaces as fine primary phases. Coarse intermetallic compounds that are formed in this aluminium alloy are characterized by unique atomic arrangement (crystallographic structure), morphology, stability, physical and mechanical properties. The volume fraction, chemistry and morphology of the intermetallics significantly affect properties and material behaviour during thermomechanical processing. Therefore, accurate determination of intermetallics is essential to understand and control microstructural evolution in Al alloys. Thus, in this paper it is shown that chemical phenol extraction method can be applied for precise qualitative evaluation. The results of optical light microscopy LOM, scanning electron microscopy SEM and X-ray diffraction XRD analysis reveal that as-cast AlSi5Cu1Mg alloy contains a wide range of intermetallic phases such as Al(4)Fe, gamma- Al(3)FeSi, alpha-Al(8)Fe(2)Si, beta-Al(5)FeSi, Al(12)FeMnSi.
Marine Origin Collagens and Its Potential Applications

PubMed Central

Silva, Tiago H.; Moreira-Silva, Joana; Marques, Ana L. P.; Domingues, Alberta; Bayon, Yves; Reis, Rui L.

2014-01-01

Collagens are the most abundant high molecular weight proteins in both invertebrate and vertebrate organisms, including mammals, and possess mainly a structural role, existing different types according with their specific organization in distinct tissues. From this, they have been elected as one of the key biological materials in tissue regeneration approaches. Also, industry is constantly searching for new natural sources of collagen and upgraded methodologies for their production. The most common sources are from bovine and porcine origin, but other ways are making their route, such as recombinant production, but also extraction from marine organisms like fish. Different organisms have been proposed and explored for collagen extraction, allowing the sustainable production of different types of collagens, with properties depending on the kind of organism (and their natural environment) and extraction methodology. Such variety of collagen properties has been further investigated in different ways to render a wide range of applications. The present review aims to shed some light on the contribution of marine collagens for the scientific and technological development of this sector, stressing the opportunities and challenges that they are and most probably will be facing to assume a role as an alternative source for industrial exploitation. PMID:25490254
Bio-Oil Hydrotreatment for Enhancing Solubility in Biodiesel and the Oxydation Stability of Resulting Blends

PubMed Central

Botella, Lucía; Stankovikj, Filip; Sánchez, José L.; Gonzalo, Alberto; Arauzo, Jesús; Garcia-Pérez, Manuel

2018-01-01

The major challenge for the pyrolytic conversion of lignocellulosic materials into crude bio-oil is the poor quality of the final product. Several strategies (addition of solvents, production of emulsions, and extraction with biodiesel) have been studied to improve its fuel properties. The extraction with biodiesel is an interesting solution because it allows direct utilization of some bio-oil fractions as fuels. However, fraction extracted with biodiesel is typically between 10 and 18 wt. %. In this paper we studied mild hydrotreatment of pyrolysis oil to enhance its solubility in biodiesel. The study was conducted with BTG and Amaron oils hydrotreated at temperatures between 200 and 325°C in the presence of Ru/C catalyst. Hydrotreated oils generated three phases: top oil (light hydrocarbons), middle aqueous phase and bottom heavy oil phase. Each of the phases was characterized and the content of acetic acid, phenols, aromatic compounds, and linear alkane hydrocarbons quantified. The upgraded bio-oils were more soluble in biodiesel than the crude bio-oils, obtaining blends with up to 48 and 38 wt. % for the BTG and Amaron bio-oil, respectively. Some of the fuel properties of the resulting blends are also reported here. PMID:29675406
Optimization and antioxidant properties of phytosynthesized silver nanoparticles using Dianthus caryophyllus L. (carnation)

NASA Astrophysics Data System (ADS)

Rachna, Saharan, Baljeet Singh; Yadav, M. S.; Sharma, Nisha

2016-05-01

In the recent years, silver nanoparticles have been the focus of Nanobiotechnology due to their unique interdisciplinary applications in the field of biomedicals, material diagnostics, optics and chemistry. A wide set of physical and chemical methods have been devised for providing the effective and efficient synthesis procedure of silver nanoparticles (AgNPs) but are somehow expensive and involve toxic substances. There is a critical need to develop reliable and eco-friendly process for synthesizing silver nanoparticles. In the present investigation, a simple and cost-effective green approach has been utilized for the production of stable silver nanoparticles by employing Dianthus caryophyllus flower extract. Different optimization conditions were checked for extract capped AgNPs and characterized by UV-Visible spectrophotometer. The optimum 0.02 dilution of extract found efficient to reduce 4 mM silver ions in the ratio 60:40 at pH 9. The antioxidant potential of the resultant AgNPs was observed using Hydrogen peroxide assay. There was an increasing trend of antioxidant property with increasing concentration. This potential of these photosynthesized AgNPs makes them reliable for good cause of society, mainly in therapeutic and biomedical applications.
Albumin profile of snakehead fish (Channastriata) from East Kalimantan, Indonesia

NASA Astrophysics Data System (ADS)

Asikin, A. N.; Kusumaningrum, I.

2018-04-01

This study aimed to determine the properties of albumin of snakehead fish (Channastrata) by various method extraction. The extraction of snakehead fish albumin was done using water (W), NaCl 0,9% (N), HCl 0.1 M (H). This research used three groups weight of snakehead that were 300-600 g (small; S), 600-900 g (medium; M) and 900-1200 g (large; L). Raw materials (snakehead fish) obtained from Middle Mahakam area, East Kalimantan, Indonesia. The parameters of this research were yield, proximate, albumin, and colour. The data were analyzed by using completely randomized design which consist two factors of treatments (solvent and weight of snakehead) and three replications.
Improvement of light extraction for a target wavelength in InGaN/GaN LEDs with an indium tin oxide dual layer by oblique angle deposition

NASA Astrophysics Data System (ADS)

Seo, Dong-Ju; Lee, Dong-Seon

2016-08-01

GaN-based blue LEDs were fabricated and studied with porous, dense, and dual-layer indium tin oxide (ITO) structures as transparent top electrodes to enhance light extraction. The electroluminescence intensity of the LED with a thickness-optimized and refractive-index-tuned ITO dual layer at I = 20 mA was higher by 19.7% than that of the conventional LED with a 200 nm planar ITO. This study confirmed that an ITO dual layer can be made with a single material by optimizing the thickness and tuning the refractive index, which improves the power output without any electrical property degradation.
Hybrid capacitive deionization with anion-exchange membranes for lithium extraction

NASA Astrophysics Data System (ADS)

Siekierka, Anna; Bryjak, Marek

2017-11-01

Lithium is considered to be a critical material for various industrial fields. We present our studies on extraction lithium from diluted aqueous solution by novel hybrid system based on a membrane capacitive deionization and batteries desalination. Hybrid CDI is comprised by a lithium selective adsorbent, activated carbon electrode and anion-exchange membranes. Here, we demonstrated implication of various type of anion-exchange membranes and influence their properties on effective capacity and energy requirements in charge/discharge steps. We described a configuration with anion-exchange membrane characterized by adsorption capacity of 35 mg/g of Li+ with 0.08Wh/g and removal efficiency of 60 % of lithium ions, using novel selective desalination technique.
Pharmacognostical studies of the plant drug Mimosae tenuiflorae cortex.

PubMed

Rivera-Arce, E; Gattuso, M; Alvarado, R; Zárate, E; Agüero, J; Feria, I; Lozoya, X

2007-09-25

The bark of the Mimosa tenuiflora (Willd.) Poiret (Leguminoseae) tree, known as tepescohuite in Mexico, is commonly used in this country and in Central America to elaborate different products for the treatment of skin burns and lesions. The cicatrizing properties of extracts obtained from this bark have been scientifically studied, attributing the main biological activity to its tannin and saponin content. Studies include clinical trials of phytodrugs based on Mimosae tenuiflora bark extracts for treatment of venous leg ulcerations. Recent commercialization of the plant drug Mimosae tenuiflorae cortex requires pharmacognostical information to develop quality-control methods for raw materials and extracts produced with this plant drug. The present paper reports a group of ethnobotanical, morphological, chemical, and molecular studies performed with Mimosae tenuiflora materials obtained by collection in the southeastern Mexican state of Chiapas. Macro- and micro-morphological parameters were established to authenticate the genuine drug that allowed detection of adulterants usually found in commercial samples of this plant material. These morphological characteristics can be used for rapid identification of the drug and are particularly useful in the case of powdered materials. The chemical studies performed demonstrated that tannins represent the major component group in the bark. Its content in genuine tepescohuite is 16% and is mainly composed of proanthocyanidins, a condition permitting a tannin-based chemical-control method for fingerprinting the plant drug. Contrariwise, the saponin concentration in Mimosae tenuiflora bark is extremely low, and its isolation and content evaluation represent a complex procedure that is unsuitable for routine control purposes. Finally, random amplified DNA (RAPD) analysis results a useful tool for obtaining DNA specific markers of Mimosae tenuiflora species which should be useful in future studies involving raw material authentication by molecular methods.
The role of lignin and lignin-like materials during wood hydrolysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zaher, F.A.

1981-01-01

The nature of the material precipitating from the acid prehydrolysates and hydrolysates of wood upon storage has been investigated. This material was analyzed for its sugar content, ultraviolet spectra, elemental composition, molecular weight distribution, and thermogravimetric behavior. All the results indicate that this material has the same properties as lignin. The results suggest also that this material is neither a resinification product from sugar decomposition nor extraneous materials of wood (resins, tannins, etc.). It is suggested, too, that the extraction of this material along with sugar during hydrolysis and prehydrolysis causes a considerable error in the results of wood analysismore » using standard methods based on weight loss. The actual percentages of lignin in the wood samples tested appear to vary from two to four times their values measured by standard methods. Consequently, the actual cellulose content of these materials may be far lower than has been reported. This has serious implications for schemes based on biomass conversion.« less
Geochemical variability of soils and biogeochemical variability of plants in the Piceance Basin, Colorado

USGS Publications Warehouse

Tuttle, M.L.; Severson, R.C.; Dean, W.E.; Klusman, R.W.

1986-01-01

Geochemical baselines for native soils and biogeochemical baselines for plants in the Piceance basin provide data that can be used to assess geochemical and biogeochemical effects of oil-shale development, monitor changes in the geochemical and biogeochemical environment during development, and assess the degree of success of rehabilitation of native materials after development. Baseline values for 52 properties in native soils, 15 properties in big sagebrush, and 13 properties in western wheatgrass were established. Our Study revealed statistically significant regional variations of the following properties across the basin: in soil&-aluminum, cobalt, copper, iron, manganese, sodium, nickel, phosphorus, lead, scandium, titanium, vanadium, zinc, organic and total carbon, pH, clay, dolomite, sodium feldspar, and DTPA-extractable calcium, cadmium, iron, potassium, manganese, nickel, phosphorus, yttrium, and zinc; in big sagebrush-barium, calcium, copper, magnesium, molybdenum, sodium, strontium, zinc, and ash; and in western wheatgrass-boron, barium, calcium, magnesium, manganese, molybdenum, strontium, zinc, and ash. These variations show up as north-south trends across the basin, or they reflect differences in elevation, hydrology, and soil parent material. Baseline values for properties that do not have statistically significant regional variations can be represented by geometric means and deviations calculated from all values within the basin. Chemical and mineralogical analyses of soil and chemical analyses of western wheatgrass samples from Colorado State University's experimental revegetation plot at Anvil Points provide data useful in assessing potential effects on soil and plant properties when largescale revegetation operations begin. The concentrations of certain properties are related to the presence of topsoil over spent shale in the lysimeters. In soils, calcium, fluorine, lithium, magnesium, sodium, phosphorus, strontium, carbonate and total carbon, and DTPA-extractable boron, copper, iron, magnesium, and nickel have lower concentrations in topsoil than in the spent oil shale; whereas, silicon, titanium, ytterbium, clay, quartz, and DTPA-extractable potassium have greater concentrations in the topsoil than in the spent oil shale. In western wheatgrass, molybdenum has a lower concentration in grasses growing on the topsoil than in grasses on the spent oil shale; whereas, barium, calcium, manganese, strontium, zinc, and ash have greater concentrations in grasses growing on the topsoil than on the spent oil shale. When compared to baseline values, soils in the revegetation plot are significantly higher in concentrations of lead, zinc, organic and total carbon, and DTP A-extractable cadmium, iron, manganese, nickel, phosphorus, and zinc. Whereas, western wheatgrass grown within the revegetation plot has concentrations which fall within the baseline values established in the regional study. The equations used in predicting concentrations of elements in plants from native and altered sites are cumbersome because of the large number of variables required to adequately predict expected concentrations and are of limited use because many explained only a small proportion of the total variation.
Wound Healing Activity of Extracts and Formulations of Aloe vera, Henna, Adiantum capillus-veneris, and Myrrh on Mouse Dermal Fibroblast Cells.

PubMed

Negahdari, Samira; Galehdari, Hamid; Kesmati, Mahnaz; Rezaie, Anahita; Shariati, Gholamreza

2017-01-01

Among the most important factors in wound healing pathways are transforming growth factor beta1 and vascular endothelial growth factor. Fibroblasts are the main cell in all phases wound closure. In this study, the extracts of plant materials such as Adiantum capillus-veneris , Commiphora molmol , Aloe vera , and henna and one mixture of them were used to treatment of normal mouse skin fibroblasts. Cytotoxic effects of each extract and their mixture were assessed on mouse skin fibroblasts cells using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. We performed migration assays to assess migration properties of mouse skin fibroblasts cells in response to the extracts. Changes in the gene expression of the Tgf β1 and Vegf-A genes were monitored by real-time polymerase chain reaction. A. capillus-veneris , C. molmol and henna extract improved the expression of Tgfβ1 gene. All used extracts upregulated the expression of Vegf-A gene and promoted the migration of mouse fibroblast cells in vitro . The present study demonstrated that the mentioned herbal extracts might be effective in wound healing, through the improvement in the migration of fibroblast cells and regulating the gene expression of Tgfβ1 and Vegf-A genes in fibroblast cells treated with extracts.
Continuous extraction of phenolic compounds from pomegranate peel using high voltage electrical discharge.

PubMed

Xi, Jun; He, Lang; Yan, Liang-Gong

2017-09-01

Pomegranate peel, a waste generated from fruit processing industry, is a potential source of phenolic compounds that are known for their anti-oxidative properties. In this study, a continuous high voltage electrical discharge (HVED) extraction system was for the first time designed and optimized for phenolic compounds from pomegranate peel. The optimal conditions for HVED were: flow rate of materials 12mL/min, electrodes gap distance 3.1mm (corresponding to 29kV/cm of electric field intensity) and liquid to solid ratio 35mL/g. Under these conditions, the experimental yield of phenolic compounds was 196.7±6.4mg/g, which closely agreed with the predicted value (199.83mg/g). Compared with the warm water maceration, HVED method possessed higher efficiency for the extraction of phenolic compounds. The results demonstrated that HVED technique could be a very effective method for continuous extraction of natural compounds. Copyright © 2017 Elsevier Ltd. All rights reserved.
Jellyfish skin polysaccharides: extraction and inhibitory activity on macrophage-derived foam cell formation.

PubMed

Zhang, Hai-Lin; Cui, Shao-Hua; Zha, Xue-Qiang; Bansal, Vibha; Xue, Lei; Li, Xiao-Long; Hao, Ran; Pan, Li-Hua; Luo, Jian-Ping

2014-06-15

In this work, response surface methodology was used to determine optimum conditions for extraction of polysaccharides from jellyfish skin (JSP). The optimum parameters were found to be raw material to water ratio 1:7.5 (w/v), extraction temperature 100°C and extraction time 4h. Under these conditions, the JSP yield reached 1.007 mg/g. Papain (15 U/mL) in combination with Sevag reagent was beneficial in removing proteins from JSP. After precipitation with ethanol at final concentration of 40%, 60% and 80% in turn, three polysaccharide fractions of JSP1, JSP2 and JSP3 were obtained from JSP, respectively. The three fractions exhibited different physicochemical properties with respect to molecular weight distribution, monosaccharide composition, infrared absorption spectra, and glycosyl bond composition. In addition, JSP3 showed strong inhibitory effects on oxidized low-density lipoprotein (oxLDL) induced conversion of macrophages into foam cells, which possibly attributed to the down-regulation of some atherogenesis-related gene expressions. Copyright © 2014 Elsevier Ltd. All rights reserved.

Experimental laboratory measurement of thermophysical properties of selected coal types

NASA Technical Reports Server (NTRS)

Lloyd, W. G.

1979-01-01

A number of bituminous coals of moderate to high plasticity were examined, along with portions of their extrudates from the JPL 1.5-inch 850 F screw extruder. Portions of the condensed pyrolysis liquids released during extrusion, and of the gaseous products formed during extrusion were also analyzed. In addition to the traditional determinations, the coals and extrudates were examined in terms of microstructure (especially extractable fractions), thermal analysis (especially that associated with the plastic state), and reactivity towards thermal and catalyzed hydroliquefaction. The process of extrusion increases the fixed carbon content of coals by about 5% and tends to increase the surface area. Coals contaning 25% or more DMF-extractable material show an increase in extractables as a result of extrusion; those initially containing less than 20% extractables show a decrease as a result of extrusion. Both the raw and extruded samples of Kentucky #9 coal are highly reactive towards hydroliquefaction, undergoing conversions of 75 to 80% in 15 min and 85-94% in 60 min in a stirred clave.
On the hydrophilicity of electrodes for capacitive energy extraction

NASA Astrophysics Data System (ADS)

Lian, Cheng; Kong, Xian; Liu, Honglai; Wu, Jianzhong

2016-11-01

The so-called Capmix technique for energy extraction is based on the cyclic expansion of electrical double layers to harvest dissipative energy arising from the salinity difference between freshwater and seawater. Its optimal performance requires a careful selection of the electrical potentials for the charging and discharging processes, which must be matched with the pore characteristics of the electrode materials. While a number of recent studies have examined the effects of the electrode pore size and geometry on the capacitive energy extraction processes, there is little knowledge on how the surface properties of the electrodes affect the thermodynamic efficiency. In this work, we investigate the Capmix processes using the classical density functional theory for a realistic model of electrolyte solutions. The theoretical predictions allow us to identify optimal operation parameters for capacitive energy extraction with porous electrodes of different surface hydrophobicity. In agreement with recent experiments, we find that the thermodynamic efficiency can be much improved by using most hydrophilic electrodes.
Antidiabetic and hypolipidemic effects of Dorema aucheri hydroalcoholic leave extract in streptozotocin-nicotinamide induced type 2 diabetes in male rats

PubMed Central

Ahangarpour, Akram; Zamaneh, Hossein Teymuri; Jabari, Ayob; Nia, Hamid Malekshahi; Heidari, Hamid

2014-01-01

Objective(s): The present study investigated the antidiabetic and hypolipidemic properties of Dorema aucheri leave hydroalcoholic extract in nicotinamide-streptozotocin induced type 2 diabetic rats. Materials and Methods: nicotinamide/streptozotocin-induced diabetic rats were supplemented orally with three different doses of D. aucheri (100, 200 and 400 mg/kg BW) or glibenclamide (0.25 mg/kg) for 4 weeks. Ultimately, blood of animals has taken and glucose, insulin, lipid profiles, SGPT, alkaline phosphatase, SGOT, leptin levels were assayed. Results: D. aucheri has highly significant blood glucose lowering effect. Administration of the extract to diabetic rats resulted in a remarkable change in serum lipid profiles, insulin and leptin levels relative to diabetic group. Also the extract reversed back the serum levels of SGPT, alkaline phosphatase and SGOT to near normal in treated diabetic rats. Conclusion: D. aucheri could be useful in treatment of diabetes. Moderate dose of D. aucheri (200 mg/kg) was more effective than the others. PMID:25729552
On the hydrophilicity of electrodes for capacitive energy extraction

DOE PAGES

Lian, Cheng; East China Univ. of Science and Technology, Shanghai; Kong, Xian; ...

2016-09-14

The so-called Capmix technique for energy extraction is based on the cyclic expansion of electrical double layers to harvest dissipative energy arising from the salinity difference between freshwater and seawater. Its optimal performance requires a careful selection of the electrical potentials for the charging and discharging processes, which must be matched with the pore characteristics of the electrode materials. While a number of recent studies have examined the effects of the electrode pore size and geometry on the capacitive energy extraction processes, there is little knowledge on how the surface properties of the electrodes affect the thermodynamic efficiency. In thismore » paper, we investigate the Capmix processes using the classical density functional theory for a realistic model of electrolyte solutions. The theoretical predictions allow us to identify optimal operation parameters for capacitive energy extraction with porous electrodes of different surface hydrophobicity. Finally, in agreement with recent experiments, we find that the thermodynamic efficiency can be much improved by using most hydrophilic electrodes.« less
Molecularly imprinted solid-phase extraction sorbent for the clean-up of chlorinated phenoxyacids from aqueous samples.

PubMed

Baggiani, C; Giovannoli, C; Anfossi, L; Tozzi, C

2001-12-14

A molecularly imprinted polymer (MIP) was synthesized using the herbicide 2,4,5-trichlorophenoxyacetic acid as a template, 4-vinylpyridine as an interacting monomer, ethylendimethacrylate as a cross-linker and a methanol-water mixture as a porogen. The binding properties and the selectivity of the polymer towards the template were investigated by frontal and zonal liquid chromatography. The polymer was used as a solid-phase extraction material for the clean-up of the template molecule and some related herbicides (2,4-dichlorophenoxyacetic acid, fenoprop, dichlorprop) from river water samples at a concentration level of ng/ml with quantitative recoveries comparable with those obtained with a traditional C18 reversed-phase column when analyzed by capillary electrophoresis. The results obtained show that the MIP-based approach to the solid-phase extraction is comparable with the more traditional solid-phase extraction with C18 reversed-phase columns in terms of recovery, but it is superior in terms of sample clean-up.
Seaweed Hydrocolloid Production: An Update on Enzyme Assisted Extraction and Modification Technologies

PubMed Central

Rhein-Knudsen, Nanna; Ale, Marcel Tutor; Meyer, Anne S.

2015-01-01

Agar, alginate, and carrageenans are high-value seaweed hydrocolloids, which are used as gelation and thickening agents in different food, pharmaceutical, and biotechnological applications. The annual global production of these hydrocolloids has recently reached 100,000 tons with a gross market value just above US$ 1.1 billion. The techno-functional properties of the seaweed polysaccharides depend strictly on their unique structural make-up, notably degree and position of sulfation and presence of anhydro-bridges. Classical extraction techniques include hot alkali treatments, but recent research has shown promising results with enzymes. Current methods mainly involve use of commercially available enzyme mixtures developed for terrestrial plant material processing. Application of seaweed polysaccharide targeted enzymes allows for selective extraction at mild conditions as well as tailor-made modifications of the hydrocolloids to obtain specific functionalities. This review provides an update of the detailed structural features of κ-, ι-, λ-carrageenans, agars, and alginate, and a thorough discussion of enzyme assisted extraction and processing techniques for these hydrocolloids. PMID:26023840
Seaweed hydrocolloid production: an update on enzyme assisted extraction and modification technologies.

PubMed

Rhein-Knudsen, Nanna; Ale, Marcel Tutor; Meyer, Anne S

2015-05-27

Agar, alginate, and carrageenans are high-value seaweed hydrocolloids, which are used as gelation and thickening agents in different food, pharmaceutical, and biotechnological applications. The annual global production of these hydrocolloids has recently reached 100,000 tons with a gross market value just above US$ 1.1 billion. The techno-functional properties of the seaweed polysaccharides depend strictly on their unique structural make-up, notably degree and position of sulfation and presence of anhydro-bridges. Classical extraction techniques include hot alkali treatments, but recent research has shown promising results with enzymes. Current methods mainly involve use of commercially available enzyme mixtures developed for terrestrial plant material processing. Application of seaweed polysaccharide targeted enzymes allows for selective extraction at mild conditions as well as tailor-made modifications of the hydrocolloids to obtain specific functionalities. This review provides an update of the detailed structural features of κ-, ι-, λ-carrageenans, agars, and alginate, and a thorough discussion of enzyme assisted extraction and processing techniques for these hydrocolloids.
Functionalization of yogurts with Agaricus bisporus extracts encapsulated in spray-dried maltodextrin crosslinked with citric acid.

PubMed

Francisco, Cristhian R L; Heleno, Sandrina A; Fernandes, Isabel P M; Barreira, João C M; Calhelha, Ricardo C; Barros, Lillian; Gonçalves, Odinei Hess; Ferreira, Isabel C F R; Barreiro, Maria Filomena

2018-04-15

Mushroom extracts contain bioactive compounds potentially useful to functionalize foodstuffs. Herein, alcoholic extracts of Agaricus bisporus were studied for their bioactivity and viability as functional ingredients in a food product with high water content (yogurt). Extracts were microencapsulated (to improve their stability and hydrophilicity) by spray-drying, using maltodextrin crosslinked with citric acid as encapsulating material. The effect of thermal treatment (after atomization) on crosslinking and bioactivity of microspheres was tested. The incorporation of free and thermally untreated forms resulted in yogurts with higher initial antioxidant activity (EC 50 values: 214 and 272 mg.mL -1 ) that decreased after 7 days (EC 50 values: 248 and 314 mg.mL -1 ). Contrarily, thermally treated microencapsulated extracts showed higher antioxidant activity after the same period (EC 50 values, 0 days: 106 mg.mL -1 ; 7 days: 48.7 mg.mL -1 ), in result of an effective protection provided by microencapsulation with crosslinked maltodextrin and citric acid. Functionalized yogurts showed an overall maintenance of nutritional properties. Copyright © 2017 Elsevier Ltd. All rights reserved.
Spray Dried Extract of Phormidium valderianum as a Promising Source of Natural Antioxidant

PubMed Central

Bhattacharjee, Paramita; Satpati, Gour Gopal; Pal, Ruma

2014-01-01

Microencapsulation of antioxidant-rich fraction obtained by supercritical carbon dioxide extraction (at 50°C, 500 bar with extraction time of 90 min, and flow rate of CO2 at 2 L/min) of lyophilized biomass of Phormidium valderianum was carried out in a spray dryer using maltodextrin and gum arabic. Microencapsulation conditions that provided the best combination of phytochemical properties such as antioxidant activity, phenolic content, and reducing power with reasonable powder yield were an inlet temperature of 130°C and wall material composition as maltodextrin: gum arabic = 70 : 30. Toxicological study reported that the Anatoxin-a content of this encapsulated powder was below the limit of detection of HPLC. Storage study established that encapsulation of this antioxidant-rich algal extract resulted in eight times enhancement of half-life (T 1/2) values. The release profile of microencapsulated antioxidant-rich fraction from the encapsulated powder was found to follow first order anomalous transport kinetics. Therefore, this microencapsulated algal extract with minimum toxicity is a source of natural antioxidant and could have promising use as novel dietary supplement. PMID:26904654
Characterisation of Redlen high-flux CdZnTe

NASA Astrophysics Data System (ADS)

Thomas, B.; Veale, M. C.; Wilson, M. D.; Seller, P.; Schneider, A.; Iniewski, K.

2017-12-01

CdZnTe is a promising material for the current generation of free electron laser light sources and future laser-driven γ-ray sources which require detectors capable of high flux imaging at X-ray and γ-ray energies (> 10 keV) . However, at high fluxes CdZnTe has been shown to polarise due to hole trapping, leading to poor performance. Novel Redlen CdZnTe material with improved hole transport properties has been designed for high flux applications. Small pixel CdZnTe detectors were fabricated by Redlen Technologies and flip-chip bonded to PIXIE ASICs. An XIA Digital Gamma Finder PIXIE-16 system was used to digitise each of the nine analogue signals with a timing resolution of 10 ns. Pulse shape analysis was used to extract the rise times and amplitude of signals. These were measured as a function of applied bias voltage and used to calculate the mobility (μ) and mobility-lifetime (μτ) of electrons and holes in the material for three identical detectors. The measured values of the transport properties of electrons in the high-flux-capable material was lower than previously reported for Redlen CdZnTe material (μeτe ~ 1 × 10-3 cm2V-1 and μe ~ 1000 cm2V-1s-1) while the hole transport properties were found to have improved (μhτh ~ 3 × 10-4 cm2V-1 and μh ~ 100 cm2V-1s-1).
LaRC TPI 1500 series polymers

NASA Technical Reports Server (NTRS)

Hou, Tan-Hung; Bai, Jia-Mo

1990-01-01

The crystallization behavior and the melt flow properties of two batches of 1500 series LaRC-TPI polymers from Mitsui Toatsu Chemicals (MTC) were investigated. The characterization methods include Differential Scanning Calorimetry, the x ray diffractography and the melt rheology. The as-received materials possess initial crystalline melting peak temperatures of 295 and 305 C, respectively. These materials are less readily recrystallizable at elevated temperatures when compared to other semicrystalline thermoplastics. For the samples annealed at temperatures below 330 C, a semicrystalline polymer can be obtained. On the other hand, a purely amorphous structure is realized in the samples annealed at temperatures above 330 C. Isothermal crystallization kinetics were studied by means of the simple Avrami equation. The viscoelastic properties at elevated temperatures below and above glass transition temperature of the polymers were measured. Information with regard to the molecule sizes and distributions in these polymers were also extracted from melt rheology.
Advances in imaging and quantification of electrical properties at the nanoscale using Scanning Microwave Impedance Microscopy (sMIM)

NASA Astrophysics Data System (ADS)

Friedman, Stuart; Stanke, Fred; Yang, Yongliang; Amster, Oskar

Scanning Microwave Impedance Microscopy (sMIM) is a mode for Atomic Force Microscopy (AFM) enabling imaging of unique contrast mechanisms and measurement of local permittivity and conductivity at the 10's of nm length scale. sMIM has been applied to a variety of systems including nanotubes, nanowires, 2D materials, photovoltaics and semiconductor devices. Early results were largely semi-quantitative. This talk will focus on techniques for extracting quantitative physical parameters such as permittivity, conductivity, doping concentrations and thin film properties from sMIM data. Particular attention will be paid to non-linear materials where sMIM has been used to acquire nano-scale capacitance-voltage curves. These curves can be used to identify the dopant type (n vs p) and doping level in doped semiconductors, both bulk samples and devices. Supported in part by DOE-SBIR DE-SC0009856.
Viscoelastic material properties' identification using high speed full field measurements on vibrating plates

NASA Astrophysics Data System (ADS)

Giraudeau, A.; Pierron, F.

2010-06-01

The paper presents an experimental application of a method leading to the identification of the elastic and damping material properties of isotropic vibrating plates. The theory assumes that the searched parameters can be extracted from curvature and deflection fields measured on the whole surface of the plate at two particular instants of the vibrating motion. The experimental application consists in an original excitation fixture, a particular adaptation of an optical full-field measurement technique, a data preprocessing giving the curvature and deflection fields and finally in the identification process using the Virtual Fields Method (VFM). The principle of the deflectometry technique used for the measurements is presented. First results of identification on an acrylic plate are presented and compared to reference values. Details about a new experimental arrangement, currently in progress, is presented. It uses a high speed digital camera to over sample the full-field measurements.
Green synthesis of silver nanoparticles using cranberry powder aqueous extract: characterization and antimicrobial properties

PubMed Central

Ashour, Asmaa A; Raafat, Dina; El-Gowelli, Hanan M; El-Kamel, Amal H

2015-01-01

Background The growing threat of microbial resistance against traditional antibiotics has prompted the development of several antimicrobial nanoparticles (NPs), including silver NPs (AgNPs). In this article, a simple and eco-friendly method for the synthesis of AgNPs using the cranberry powder aqueous extract is reported. Materials and methods Cranberry powder aqueous extracts (0.2%, 0.5%, and 0.8% w/v) were allowed to interact for 24 hours with a silver nitrate solution (10 mM) at 30°C at a ratio of 1:10. The formation of AgNPs was confirmed by ultraviolet-visible spectroscopy and their concentrations were determined using atomic absorption spectroscopy. The prepared NPs were evaluated by transmission electron microscopy, measurement of ζ-potential, and Fourier-transform infrared spectroscopy. The in vitro antimicrobial properties of AgNPs were then investigated against several microbial strains. Finally, in vivo appraisal of both wound-healing and antimicrobial properties of either plain AgNPs (prepared using 0.2% extract) or AgNP-Pluronic F-127 gel was conducted in a rat model after induction of a Staphylococcus aureus ATCC 6538P wound infection. Results The formation of AgNPs was confirmed by ultraviolet-visible spectroscopy, where a surface-plasmon resonance absorption peak was observed between 432 and 438 nm. Both size and concentration of the formed AgNPs increased with increasing concentration of the extracts. The developed NPs were stable, almost spherical, and polydisperse, with a size range of 1.4–8.6 nm. The negative ζ-potential values, as well as Fourier-transform infrared spectroscopy analysis, indicated the presence of a capping agent adsorbed onto the surface of the particles. In vitro antimicrobial evaluation revealed a size-dependent activity of the AgNPs against the tested organisms. Finally, AgNPs prepared using 0.2% extract exhibited a substantial in vivo healing potential for full-thickness excision wounds in rats. Conclusion AgNPs were successfully synthesized from a silver nitrate solution through a simple green route, using cranberry powder aqueous extract as a reducing as well as capping agent. PMID:26664112
Bioefficacy of larvicdial and pupicidal properties of Carica papaya (Caricaceae) leaf extract and bacterial insecticide, spinosad, against chikungunya vector, Aedes aegypti (Diptera: Culicidae).

PubMed

Kovendan, Kalimuthu; Murugan, Kadarkarai; Naresh Kumar, Arjunan; Vincent, Savariar; Hwang, Jiang-Shiou

2012-02-01

The present study was carried out to establish the properties of Carica papaya leaf extract and bacterial insecticide, spinosad on larvicidal and pupicidal activity against the chikungunya vector, Aedes aegypti. The medicinal plants were collected from the area around Bharathiar University, Coimbatore, India. C. papaya leaf was washed with tap water and shade-dried at room temperature. An electrical blender powdered the dried plant materials (leaves). The powder (500 g) of the leaf was extracted with 1.5 l of organic solvents of methanol for 8 h using a Soxhlet apparatus and then filtered. The crude leaf extracts were evaporated to dryness in a rotary vacuum evaporator. The plant extract showed larvicidal and pupicidal effects after 24 h of exposure; however, the highest larval and pupal mortality was found in the leaf extract of methanol C. papaya against the first- to fourth-instar larvae and pupae of values LC(50) = I instar was 51.76 ppm, II instar was 61.87 ppm, III instar was 74.07 ppm, and IV instar was 82.18 ppm, and pupae was 440.65 ppm, respectively, and bacterial insecticide, spinosad against the first to fourth instar larvae and pupae of values LC(50) = I instar was 51.76 ppm, II instar was 61.87 ppm, III instar was 74.07 ppm, and IV instar was 82.18 ppm, and pupae was 93.44 ppm, respectively. Moreover, combined treatment of values of LC(50) = I instar was 55.77 ppm, II instar was 65.77 ppm, III instar was 76.36 ppm, and IV instar was 92.78 ppm, and pupae was 107.62 ppm, respectively. No mortality was observed in the control. The results that the leaves extract of C. papaya and bacterial insecticide, Spinosad is promising as good larvicidal and pupicidal properties of against chikungunya vector, A. aegypti. This is an ideal eco-friendly approach for the control of chikungunya vector, A. aegypti as target species of vector control programs.
Physical properties of root cementum: Part I. A new method for 3-dimensional evaluation.

PubMed

Malek, S; Darendeliler, M A; Swain, M V

2001-08-01

Cementum is a nonuniform connective tissue that covers the roots of human teeth. Investigation of the physical properties of cementum may help in understanding or evaluating any possible connection to root resorption. A variety of engineering tests are available to investigate these properties. However, the thickness of the cementum layer varies, and this limits the applicability of these techniques in determining the physical properties of cementum. Hardness testing with Knoop and Vickers indentations overcame some of these limitations, but they prohibited the retrieval and retesting of the sample and therefore the testing was restricted to one area or section of the tooth. Another limiting factor with the existing techniques was the risk of artifacts related to the embedding material such as acrylic. A new method to investigate the physical properties of human premolar cementum was developed to obtain a 3-dimensional map of these properties with the Ultra Micro Indentation System (UMIS-2000; Commonwealth Scientific and Industrial Research Organization, Campbell, Australia). UMIS-2000 is a nano-indentation instrument for investigation of the properties of the near-surface region of materials. Premolars were harvested from orthodontic patients requiring extractions and then mounted on a newly designed surveyor that allowed sample retrieval and 3-dimensional rotation. This novel method enabled the quantitative testing of root surface cementum, on all 4 root surfaces, extending from the apex to the cementoenamel junction at 60 different sites.
Wound healing activity of Argyreia nervosa leaves extract

PubMed Central

Singhal, AK; Gupta, H; Bhati, VS

2011-01-01

Background: Argyreia nervosa (Convolvulaceae) plant is an example of hallucinogenic plant. The antiseptic, anti-inflammatory, antispasmodic, antibacterial, antiviral, antifungal, anticonvulsant, nootropic, antifertility and aphrodisiac properties have already been reported for this plant. Aim: The aim of present work was to evaluate the wound healing property in normal and diabetic animals by oral and topical administration of ethanolic extract of leaves. Materials and Methods: Phytochemical investigations showed the presence of various biochemicals (alkaloids, flavonoids, carbohydrates, triterpenoids, proteins, saponins, steroids, tannins). A single injection of alloxan monohydrate (120 mg/kg, i.p.) prepared in citrate buffer (0.1 M, pH 4.5) was administered to produce diabetes in rats and mice, after overnight fasting. Excision wounds (sized 300 mm2 and of 2 mm depth) were used for the study of rate of contraction of wound and epithelization. The means of wound area measurement between groups at different time intervalswere compared using one-way analysis of variance (ANOVA), followed by Dunnet's test. Results: Extracts of A. nervosa showed significant wound healing effect in normal (topically treated) and diabetic (both topically and orally treated) rats. In diabetic rats, the topically treated group showed more significant effect than the orally treated groups. Conclusion: The present study demonstrates that A. nervosa leaves extract applied topically promotes healing of wounds more significantly as compared to oral application, in both normal rats and alloxan induced diabetic rats, where healing is otherwise delayed. PMID:23776770
Characterization of low-temperature properties of plant-produced rap mixtures in the Northeast

NASA Astrophysics Data System (ADS)

Medeiros, Marcelo S., Junior

The dissertation outlined herein results from a Federal Highway Administration sponsored project intended to investigate the impacts of high percentages of RAP material in the performance of pavements under cold climate conditions. It is comprised of two main sections that were incorporated into the body of this dissertation as Part I and Part II. In Part I a reduced testing framework for analysis of HMA mixes was proposed to replace the IDT creep compliance and strength testing by dynamic modulus and fatigue tests performed on an AMPT device. A continuum damage model that incorporates the nonlinear constitutive behavior of the HMA mixtures was also successfully implemented and validated. Mixtures with varying percentages of reclaimed material (RAP) ranging from 0 to 40% were used in this research effort in order to verify the applicability of the proposed methodology to RAP mixtures. Part II is concerned with evaluating the effects of various binder grades on the properties of plant-produced mixtures with various percentages of RAP. The effects of RAP on mechanical and rheological properties of mixtures and extracted binders were studied in order to identify some of the deficiencies in the current production methodologies. The results of this dissertation will help practitioners to identify optimal RAP usage from a material property perspective. It also establishes some guidelines and best practices for the use of higher RAP percentages in HMA.
Towards sustainable processing of columbite group minerals: elucidating the relation between dielectric properties and physico-chemical transformations in the mineral phase.

PubMed

Sanchez-Segado, Sergio; Monti, Tamara; Katrib, Juliano; Kingman, Samuel; Dodds, Chris; Jha, Animesh

2017-12-21

Current methodologies for the extraction of tantalum and niobium pose a serious threat to human beings and the environment due to the use of hydrofluoric acid (HF). Niobium and tantalum metal powders and pentoxides are widely used for energy efficient devices and components. However, the current processing methods for niobium and tantalum metals and oxides are energy inefficient. This dichotomy between materials use for energy applications and their inefficient processing is the main motivation for exploring a new methodology for the extraction of these two oxides, investigating the microwave absorption properties of the reaction products formed during the alkali roasting of niobium-tantalum bearing minerals with sodium bicarbonate. The experimental findings from dielectric measurement at elevated temperatures demonstrate an exponential increase in the values of the dielectric properties as a result of the formation of NaNbO 3 -NaTaO 3 solid solutions at temperatures above 700 °C. The investigation of the evolution of the dielectric properties during the roasting reaction is a key feature in underpinning the mechanism for designing a new microwave assisted high-temperature process for the selective separation of niobium and tantalum oxides from the remainder mineral crystalline lattice.
[Phenolic foam prepared by lignin from a steam-explosion derived biorefinery of corn stalk].

PubMed

Wang, Guanhua; Chen, Hongzhang

2014-06-01

To increase the integral economic effectiveness, biorefineries of lignocellulosic materials should not only utilize carbohydrates hydrolyzed from cellulose and hemicellulose but also use lignin. We used steam-exploded corn stalk as raw materials and optimized the temperature and alkali concentration in the lignin extraction process to obtain lignin liquor with higher yield and purity. Then the concentrated lignin liquor was used directly to substitute phenol for phenolic foam preparation and the performances of phenolic foam were characterized by microscopic structure analysis, FTIR, compression strength and thermal conductivity detection. The results indicated that, when steam-exploded corn stalk was extracted at 120 degrees C for 2 h by 1% NaOH with a solid to liquid ratio of 1:10, the extraction yield of lignin was 79.67%. The phenolic foam prepared from the concentrated lignin liquor showed higher apparent density and compression strength with the increasing substitution rate of lignin liquor. However, there were not significant differences of thermal conductivity and flame retardant properties by the addition of lignin, which meant that the phenolic foam substituted by lignin liquor was approved for commercial application. This study, which uses alkali-extracted lignin liquor directly for phenolic foam preparation, provides a relatively simple way for utilization of lignin and finally increases the overall commercial operability ofa lignocellulosic biorefinery derived by steam explosion.

Recovery of Palm Oil and Valuable Material from Oil Palm Empty Fruit Bunch by Sub-critical Water.

PubMed

Ahmad Kurnin, Nor Azrin; Shah Ismail, Mohd Halim; Yoshida, Hiroyuki; Izhar, Shamsul

2016-01-01

Oil palm empty fruit bunch (EFB) is one of the solid wastes produced in huge volume by palm oil mill. Whilst it still contains valuable oil, approximately 22.6 million tons is generated annually and treated as solid waste. In this work, sub-critical water (sub-cw) was used to extract oil, sugar and tar from spikelet of EFB. The spikelet was treated with sub-cw between 180-280°C and a reaction time of 2 and 5 minutes. The highest yield of oil was 0.075 g-oil/g-dry EFB, obtained at 240°C and reaction time of 5 minutes. Astonishingly, oil that was extracted through this method was 84.5% of that obtained through Soxhlet method using hexane. Yield of oil extracted was strongly affected by the reaction temperature and time. Higher reaction temperature induces the dielectric constant of water towards the non-polar properties of solvent; thus increases the oil extraction capability. Meanwhile, the highest yield of sugar was 0.20 g-sugar/g-dry EFB obtained at 220°C. At this temperature, the ion product of water is high enough to enable maximum sub-critical water hydrolysis reaction. This study showed that oil and other valuable material can be recovered using water at sub-critical condition, and most attractive without the use of harmful organic solvent.
Magnetic resonance studies of dissolving particulate solids.

PubMed

Johns, M L; Gladden, L F

2003-01-01

Magnetic resonance methods have been used to elucidate the internal pore structure of particulate solids, in particular detergent tablets. Such information is essential to a comprehensive understanding of the dissolution characteristics of these materials and how this property is related to processing conditions during tablet formation. In particular 3-D images of porosity are produced and 2-D self-diffusion maps are acquired as a function of observation time, which enables pore size to be quantified as a function of position via the extracted surface-to-volume ratio of the pore space. These properties are determined as a function of processing parameters, in particular the compression force used in tablet formation.
Dynamic tuning by hydrostatic pressure of magnetocaloric properties to Ericsson like cycles

NASA Astrophysics Data System (ADS)

Gaztañaga, P.; Sacanell, J.; Leyva, A. G.; Quintero, M.

2018-03-01

A method to increase the relative cooling power to be used in Ericsson like refrigeration cycles is presented. The technique is based in the modification of the magnetic properties by the application of hydrostatic pressure on magnetic samples. The main advantage is to reach larger values of the magnetic entropy change in a wider temperature region (the so-called "table like" behavior). The study was carried out in a manganite belonging to the family of La0.625-yNdyCa0.375MnO3, and some conclusions were compared with the expected behavior in other materials extracted from literature.
Elastic cavitation and fracture via injection.

PubMed

Hutchens, Shelby B; Fakhouri, Sami; Crosby, Alfred J

2016-03-07

The cavitation rheology technique extracts soft materials mechanical properties through pressure-monitored fluid injection. Properties are calculated from the system's response at a critical pressure that is governed by either elasticity or fracture (or both); however previous elementary analysis has not been capable of accurately determining which mechanism is dominant. We combine analyses of both mechanisms in order to determine how the full system thermodynamics, including far-field compliance, dictate whether a bubble in an elastomeric solid will grow through either reversible or irreversible deformations. Applying these analyses to experimental data, we demonstrate the sensitivity of cavitation rheology to microstructural variation via a co-dependence between modulus and fracture energy.
Nanoscale determination of the mass enhancement factor in the lightly doped bulk insulator lead selenide

DOE PAGES

Zeljkovic, Ilija; Scipioni, Kane L.; Walkup, Daniel; ...

2015-03-27

Bismuth chalcogenides and lead telluride/selenide alloys exhibit exceptional thermoelectric properties that could be harnessed for power generation and device applications. Since phonons play a significant role in achieving these desired properties, quantifying the interaction between phonons and electrons, which is encoded in the Eliashberg function of a material, is of immense importance. However, its precise extraction has in part been limited due to the lack of local experimental probes. Here we construct a method to directly extract the Eliashberg function using Landau level spectroscopy, and demonstrate its applicability to lightly doped thermoelectric bulk insulator PbSe. In addition to its highmore » energy resolution only limited by thermal broadening, this novel experimental method could be used to detect variations in mass enhancement factor at the nanoscale level. Finally, this opens up a new pathway for investigating the local effects of doping and strain on the mass enhancement factor.« less
H. R. 1376: A bill to amend titles II, V, and VII of the Surface Mining Control and Reclamation Act of 1977 to make the mining of coal without a permit a criminal offense, and for other purposes. Introduced in the House of Representatives, One Hundredth First Congress, First Session, March 13, 1989

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1989-01-01

This bill amends the 250 ton limit listed in section I. to read 25 ton limit. It would make it a criminal offense to knowingly remove, transport, sell, or purchase coal from a surface mining operation without a permit required by State or Federal governments. A person convicted under this law would be prohibited from obtaining permits for the extraction or processing of coal. Property of the convicted person subject to forfeiture would be all coal involved; all moneys or securities used in the exchange; and all materials, products, implements, machinery, conveyance, equipment, and property of any kind used ormore » intended for use in extracting, conveying, storing, or delivering coal mined in violation of this law.« less
An explicit asymptotic model for the surface wave in a viscoelastic half-space based on applying Rabotnov's fractional exponential integral operators

NASA Astrophysics Data System (ADS)

Wilde, M. V.; Sergeeva, N. V.

2018-05-01

An explicit asymptotic model extracting the contribution of a surface wave to the dynamic response of a viscoelastic half-space is derived. Fractional exponential Rabotnov's integral operators are used for describing of material properties. The model is derived by extracting the principal part of the poles corresponding to the surface waves after applying Laplace and Fourier transforms. The simplified equations for the originals are written by using power series expansions. Padè approximation is constructed to unite short-time and long-time models. The form of this approximation allows to formulate the explicit model using a fractional exponential Rabotnov's integral operator with parameters depending on the properties of surface wave. The applicability of derived models is studied by comparing with the exact solutions of a model problem. It is revealed that the model based on Padè approximation is highly effective for all the possible time domains.
In vitro biomechanical and biocompatible evaluation of natural hydroxyapatite/chitosan composite for bone repair.

PubMed

Lü, Xiaoying; Zheng, Buzhong; Tang, Xiaojun; Zhao, Lifeng; Lu, Jieyan; Zhang, Zhiwei; Zhang, Jizhong; Cui, Wei

2011-01-01

To evaluate the biomechanical properties and biocompatibility of natural hydroxyapatite/chitosan (HA/CS) composites. The natural HA/CS composites with a different proportion of HA and CS were prepared by the cross-linking method, and then the compressive strength, microstructure and pH values of extracts from these composites were measured by SEM and pH meter, respectively. Subsequently, the biocompatibility of the composites was evaluated by means of a series of biological tests, including MTT, acute systemic toxicity, heat source, and hemolysis tests in vitro. The chitosan content in the composites had significantly influenced the mechanical properties and microstructure of the composites. The pH value of the composite extract was approximately 7.0, which was very close to that of human plasma. Furthermore, the natural HA/CS composites showed no cytotoxicity, irritation, teratogenicity, carcinogenicity and special pyrogen. These results indicated that the natural HA/CS composite may be a potential bone repair material.
Preparation of Silica Aerogel from TEOS

PubMed

Tamon; Kitamura; Okazaki

1998-01-15

Silica alcogels were synthesized by the sol-gel polymerization of tetraethylorthosilicate (TEOS). In the synthesis, HCl and NH3 were used as hydrolysis and condensation catalysts. The gelation time became short and the visible light transmittance increased with increasing the amount of HCl or lengthening the hydrolysis time. The alcogels were dried under supercritical conditions with carbon dioxide, and silica aerogels were obtained. As a result of characterization by visible light transmission and N2 adsorption, the aerogels are mesoporous materials with high surface areas. The experimental results suggest that the aerogel properties are not influenced by the drying conditions such as extraction temperature, extraction time, depressurizing temperature, and depressurizing rate. On the other hand, the properties are changed under the conditions of sol-gel polymerization. In the preparation of highly transparent aerogels with high surface areas and large pore volumes, it is necessary to synthesize highly transparent alcogels. It is found that the visible light transmittance of alcogels is an index for preparing aerogels from TEOS. Copyright 1998 Academic Press. Copyright 1998Academic Press
Hibiscus rosa- sinensis leaf extract as coagulant aid in leachate treatment

NASA Astrophysics Data System (ADS)

Awang, Nik Azimatolakma; Aziz, Hamidi Abdul

2012-12-01

Hibiscus rosa- sinensis is a biodegradable material that has remained untested for flocculating properties. The objective of this study is to examine the efficiency of coagulation-flocculation processes for the removal of color, iron (Fe3+), suspended solids, turbidity and ammonia nitrogen(NH3-N), from landfill leachate using 4,000 mg/L alum in conjunction with H. rosa- sinensis leaf extract (HBaqs). Hydroxyl (O-H) and (carboxyl) C=O functional groups along the HBaqs chain help to indulge flocculating efficiency of HBaqs via bridging. The experiments confirm the positive coagulation properties of HBaqs. The Fe3+ removal rate using 4,000 mg/L alum as sole coagulant was approximately 60 %, and increased to 100 % when 4,000 mg/L alum was mixed with 500 mg/L HBaqs. By mixing, 4,000 mg/L alum with 100-500 mg/L HBaqs, 72 % of SS was removed as compared with only 45 % reduction using 4,000 mg/L alum as sole coagulant.
A universal route for the simultaneous extraction and functionalization of cellulose nanocrystals from industrial and agricultural celluloses

NASA Astrophysics Data System (ADS)

Chen, Guo-Yin; Yu, Hou-Yong; Zhang, Cai-Hong; Zhou, Ying; Yao, Ju-Ming

2016-02-01

A simple route was designed to extract the cellulose nanocrystals (CNCs) with formate groups from industrial and agricultural celluloses like microcrystalline cellulose (MCC), viscose fiber, ginger fiber, and bamboo fiber. The effect of reaction time on the microstructure and properties of the CNCs was investigated in detail, while microstructure and properties of different CNCs were compared. The rod-like CNCs (MCC) with hundreds of nanometers in length and about 10 nm in width, nanofibrillated CNCs (ginger fiber bamboo fiber) with average width of 30 nm and the length of 1 μm, and spherical CNCs (viscose fiber) with the width of 56 nm were obtained by one-step HCOOH/HCl hydrolysis. The CNCs with improved thermal stability showed the maximum degradation temperature ( T max) of 368.9-388.2 °C due to the introduction of formate groups (reducibility) and the increased crystallinity. Such CNCs may be used as an effective template for the synthesis of nanohybrids or reinforcing material for high-performance nanocomposites.
Soil hydraulic material properties and layered architecture from time-lapse GPR

NASA Astrophysics Data System (ADS)

Jaumann, Stefan; Roth, Kurt

2018-04-01

Quantitative knowledge of the subsurface material distribution and its effective soil hydraulic material properties is essential to predict soil water movement. Ground-penetrating radar (GPR) is a noninvasive and nondestructive geophysical measurement method that is suitable to monitor hydraulic processes. Previous studies showed that the GPR signal from a fluctuating groundwater table is sensitive to the soil water characteristic and the hydraulic conductivity function. In this work, we show that the GPR signal originating from both the subsurface architecture and the fluctuating groundwater table is suitable to estimate the position of layers within the subsurface architecture together with the associated effective soil hydraulic material properties with inversion methods. To that end, we parameterize the subsurface architecture, solve the Richards equation, convert the resulting water content to relative permittivity with the complex refractive index model (CRIM), and solve Maxwell's equations numerically. In order to analyze the GPR signal, we implemented a new heuristic algorithm that detects relevant signals in the radargram (events) and extracts the corresponding signal travel time and amplitude. This algorithm is applied to simulated as well as measured radargrams and the detected events are associated automatically. Using events instead of the full wave regularizes the inversion focussing on the relevant measurement signal. For optimization, we use a global-local approach with preconditioning. Starting from an ensemble of initial parameter sets drawn with a Latin hypercube algorithm, we sequentially couple a simulated annealing algorithm with a Levenberg-Marquardt algorithm. The method is applied to synthetic as well as measured data from the ASSESS test site. We show that the method yields reasonable estimates for the position of the layers as well as for the soil hydraulic material properties by comparing the results to references derived from ground truth data as well as from time domain reflectometry (TDR).
Engineered Materials for Cesium and Strontium Storage Final Technical Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sean M. McDeavitt

2010-04-14

Closing the nuclear fuel cycle requires reprocessing spent fuel to recover the long-lived components that still have useful energy content while immobilizing the remnant waste fission products in stable forms. At the genesis of this project, next generation spent fuel reprocessing methods were being developed as part of the U.S. Department of Energy's Advanced Fuel Cycle Initiative. One of these processes was focused on solvent extraction schemes to isolate cesium (Cs) and strontium (Sr) from spent nuclear fuel. Isolating these isotopes for short-term decay storage eases the design requirements for long-term repository disposal; a significant amount of the radiation andmore » decay heat in fission product waste comes from Cs-137 and Sr-90. For the purposes of this project, the Fission Product Extraction (FPEX) process is being considered to be the baseline extraction method. The objective of this project was to evaluate the nature and behavior of candidate materials for cesium and strontium immobilization; this will include assessments with minor additions of yttrium, barium, and rubidium in these materials. More specifically, the proposed research achieved the following objectives (as stated in the original proposal): (1) Synthesize simulated storage ceramics for Cs and Sr using an existing labscale steam reformer at Purdue University. The simulated storage materials will include aluminosilicates, zirconates and other stable ceramics with the potential for high Cs and Sr loading. (2) Characterize the immobilization performance, phase structure, thermal properties and stability of the simulated storage ceramics. The ceramic products will be stable oxide powders and will be characterized to quantify their leach resistance, phase structure, and thermophysical properties. The research progressed in two stages. First, a steam reforming process was used to generate candidate Cs/Sr storage materials for characterization. This portion of the research was carried out at Purdue University and is detailed in Appendix A. Steam reforming proved to be too rigorous for efficient The second stage of this project was carried out at Texas A&M University and is Detailed in Appendix B. In this stage, a gentler ceramic synthesis process using Cs and Sr loaded kaolinite and bentonite clays was developed in collaboration with Dr. M. Kaminski at Argonne National Laboratory.« less
Study of pharmacological activities of methanol extract of Jatropha gossypifolia fruits

PubMed Central

Apu, Apurba Sarker; Hossain, Faruq; Rizwan, Farhana; Bhuyan, Shakhawat Hossan; Matin, Maima; Jamaluddin, A.T.M

2012-01-01

Objective: The present study was carried out to investigate the possible in vivo analgesic, neuropharmacological and anti-diarrheal activities of the methanol extract of Jatropha gossypifolia fruits. Materials and Methods: The analgesic activity was measured by acetic acid induced writhing inhibition test. The neuropharmacological activities were evaluated by hole cross, hole-board, and elevated plus-maze (EPM) tests and the anti-diarrheal activity was assessed by castor oil induced diarrhea inhibition method. Findings: The extract showed highly significant (P < 0.001) analgesic activity with % inhibitions of writhing response at doses 200 and 400 mg/kg body weight were 77.86% and 71.25%, respectively. The extract at both doses showed significant (P < 0.05) sedative effect in-hole cross test. In-hole board test, the extract showed highly significant (P < 0.001) anxiolytic activity at lower dose whereas this activity was observed at higher dose in EPM test. The extract also showed highly significant (P < 0.001) anti-diarrheal activity. Conclusion: The findings of the study clearly indicate the presence of significant analgesic, neuropharmacological and anti-diarrheal properties of the plant, which demands further investigation including, compound isolation. PMID:24808665
Mineral and Phytochemical Profiles and Antioxidant Activity of Herbal Material from Two Temperate Astragalus Species

PubMed Central

Dagilytė, Audronė; Lemežienė, Nijolė

2018-01-01

Only a few species of the large Astragalus genus, widely used for medicinal purposes, have been thoroughly studied for phytochemical composition. The aim of our research was to investigate the rarely studied species A. glycyphyllos L. and A. cicer L. for the distribution of mineral elements and phytochemicals in whole plants at two growth stages and in morphological fractions. We also investigated the capacity of the plant extracts to scavenge 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals and to chelate ferrous ions. Chemical composition and antioxidant properties depended on species, maturity, and plant part. Herbal material of A. glycyphyllos was richer in Fe, total phenolics, and flavonoids, whereas extracts of A. cicer showed a higher antioxidant activity. Young plants had more isoflavones, showed greater quenching of DPPH radicals, and exhibited better mineral profiles than flowering plants. Among plant parts, leaves were the most valuable plant material according to most characteristics investigated. Isoflavone concentration in flowers was lower than in leaves and stems. None of the Astragalus samples contained detectable amounts of the alkaloid swainsonine. The study demonstrates the potential of plant material from two Astragalus species as a valuable source of iron, phenolic substances including isoflavones, free-radical scavengers, and Fe2+ chelators for pharmaceutical use. PMID:29581980
Investigation of Transport Properties of a New Biomaterials - GUM Mangosteen

NASA Astrophysics Data System (ADS)

Pradhan, Sourav S.; Sarkar, A.

2006-06-01

Biomaterial has occupied leading position in material science for various scientific and technological applications. This present work is carried out over a natural gum extracted from raw fruit of Mangosteen, an east Indian tree (Gercinia Mangostana) following extraction and purification process. Solid specimen of the said gum is developed following sol-gel like process. AC and DC electrical analysis on the dried solid specimen of the gum were carried out and showed high electrical conduction with σ ~ 1 E-03 S/cm, of which ionic and electronic contributions are 70% and 30% respectively. Analysis shows that origin of high electrical conductivity is due to presence of substantial amount of organic acid unit in its polysaccharide background. In fact the observed σ is about 1000 times of that observed in gum Arabica. Optical absorption of this new bio- materials are also studied using UV-VIS analysis. The results show its high absorption co-efficient in UV and blue part of analysed range. A complete electrical characterization of the material have been made. It has also been observed that the electronic conduction can be enhanced to 70% of the total electrical conductivity by forming complex with Iodine and organic (Citric) acid from Lemon fruit. This high potential material is being studied for development of electronic device application.
Quantitative analysis of the local phase transitions induced by the laser heating

DOE PAGES

Levlev, Anton V.; Susner, Michael A.; McGuire, Michael A.; ...

2015-11-04

Functional imaging enabled by scanning probe microscopy (SPM) allows investigations of nanoscale material properties under a wide range of external conditions, including temperature. However, a number of shortcomings preclude the use of the most common material heating techniques, thereby limiting precise temperature measurements. Here we discuss an approach to local laser heating on the micron scale and its applicability for SPM. We applied local heating coupled with piezoresponse force microscopy and confocal Raman spectroscopy for nanoscale investigations of a ferroelectric-paraelectric phase transition in the copper indium thiophosphate layered ferroelectric. Bayesian linear unmixing applied to experimental results allowed extraction of themore » Raman spectra of different material phases and enabled temperature calibration in the heated region. Lastly, the obtained results enable a systematic approach for studying temperature-dependent material functionalities in heretofore unavailable temperature regimes.« less
Soybean protein-based microparticles for oral delivery of probiotics with improved stability during storage and gut resistance.

PubMed

González-Ferrero, C; Irache, J M; González-Navarro, C J

2018-01-15

The present work describes the encapsulation of probiotics using a by-product as wall material and a process feasible to be scaled-up: coacervation of soybean protein concentrate (SPC) by using calcium salts and spray-drying. SPC was extracted from soybean flour, produced during the processing of soybean milk, by alkaline extraction following isoelectric precipitation. Two probiotic strains were selected for encapsulation (Lactobacillus plantarum CECT 220 and Lactobacillus casei CECT 475) in order to evaluate the ability of SPC to encapsulate and protect bacteria from stress conditions. The viability of these encapsulated strains under in vitro gastrointestinal conditions and shelf-life during storage were compared with the most common forms commercialized nowadays. Results show that SPC is a feasible material for the development of probiotic microparticles with adequate physicochemical properties and enhanced significantly both probiotic viability and tolerance against simulated gastrointestinal fluids when compared to current available commercial forms. Copyright © 2017 Elsevier Ltd. All rights reserved.
Advances in the analysis of biological samples using ionic liquids.

PubMed

Clark, Kevin D; Trujillo-Rodríguez, María J; Anderson, Jared L

2018-02-12

Ionic liquids are a class of solvents and materials that hold great promise in bioanalytical chemistry. Task-specific ionic liquids have recently been designed for the selective extraction, separation, and detection of proteins, peptides, nucleic acids, and other physiologically relevant analytes from complex biological samples. To facilitate rapid bioanalysis, ionic liquids have been integrated in miniaturized and automated procedures. Bioanalytical separations have also benefited from the modification of nonspecific magnetic materials with ionic liquids or the implementation of ionic liquids with inherent magnetic properties. Furthermore, the direct detection of the extracted molecules in the analytical instrument has been demonstrated with structurally tuned ionic liquids and magnetic ionic liquids, providing a significant advantage in the analysis of low-abundance analytes. This article gives an overview of these advances that involve the application of ionic liquids and derivatives in bioanalysis. Graphical abstract Ionic liquids, magnetic ionic liquids, and ionic liquid-based sorbents are increasing the speed, selectivity, and sensitivity in the analysis of biological samples.
Testing the stability of magnetic iron oxides/kaolinite nanocomposite under various pH conditions

NASA Astrophysics Data System (ADS)

Tokarčíková, Michaela; Tokarský, Jonáš; Kutláková, Kateřina Mamulová; Seidlerová, Jana

2017-09-01

Magnetically modified clays containing iron oxides nanoparticles (FexOy NPs) are low-cost and environmentally harmless materials suitable for sorption of pollutants from wastewaters. Stability of this smart material was evaluated both experimentally and theoretically using molecular modelling. Original kaolinite and prepared FexOy/kaolinite nanocomposite were characterized using X-ray fluorescence spectroscopy, X-ray powder diffraction, infrared spectroscopy, and transmission electron microscopy, and the stability was studied using leaching tests performed according to the European technical standard EN 12457-2 in deionized water and extraction agents with varying pH (2, 4, 9, and 11). The influence of pH on amount of FexOy NPs released from the composite and amount of the basic elements released from the kaolinite structure was studied using inductively coupled plasma atomic emission spectroscopy. All experiments proved that the magnetic properties of the nanocomposite will not change even after leaching in extraction agents with various pH.

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