Water transfer properties and shrinkage in lime-based rendering mortars

NASA Astrophysics Data System (ADS)

Arizzi, A.; Cultrone, G.

2012-04-01

Rendering is the practice of covering a wall or a building façade with one or more layers of mortar, with the main aim to protect the masonry structure against weathering. The render applied must show high flexibility, good adhesion and compatibility with the support (i.e. stone, brick) and, overall, it should be characterised by low water absorption and high water vapour permeability. Water (in the solid, liquid and vapour state) is one of the main factors that drive construction materials to deterioration. Therefore, to evaluate the quality and durability of a rendering mortar, thus ensuring its protective function in the masonry structure, it is fundamental to assess the behaviour of this mortar towards water. Mortars were elaborated with a calcitic dry hydrated lime, a calcareous aggregate, a pozzolan, a lightweight aggregate, a water-retaining agent and a plasticiser. Four types of lime mortars were prepared, in which the binder-to-aggregate ratios were 1:3, 1:4, 1:6 and 1:9 by weight, whilst the pozzolan was kept at 10% of the lime (by mass) and the total admixtures proportion was less than 2% of the total mass. The influence of the characteristics of mortars pore system on the amount of water absorbed and the kinetics of absorption was investigated by means of: free water absorption and drying; capillary uptake; water permeability; water vapour permeability. Interesting deductions can be made from the values of water and water vapour permeability found for mortars: the former increases exponentially with the sand volume of the mortar, whilst the latter increases almost exponentially with the initial water content added to the mortar mixes during their elaboration. However, the relationship obtained between porosity of mortars and permeability values is not really clear. This finding suggests that the permeability of a material cannot be estimated on the basis of its porosity as it can be made for the capillary uptake and free water absorption. Another

Porosity estimation of aged mortar using a micromechanical model.

PubMed

Hernández, M G; Anaya, J J; Sanchez, T; Segura, I

2006-12-22

Degradation of concrete structures located in high humidity atmospheres or under flowing water is a very important problem. In this study, a method for ultrasonic non-destructive characterization in aged mortar is presented. The proposed method makes a prediction of the behaviour of aged mortar accomplished with a three phase micromechanical model using ultrasonic measurements. Aging mortar was accelerated by immersing the probes in ammonium nitrate solution. Both destructive and non-destructive characterization of mortar was performed. Destructive tests of porosity were performed using a vacuum saturation method and non-destructive characterization was carried out using ultrasonic velocities. Aging experiments show that mortar degradation not only involves a porosity increase, but also microstructural changes in the cement matrix. Experimental results show that the estimated porosity using the proposed non-destructive methodology had a comparable performance to classical destructive techniques.

Reuse of ground waste glass as aggregate for mortars.

PubMed

Corinaldesi, V; Gnappi, G; Moriconi, G; Montenero, A

2005-01-01

This work was aimed at studying the possibility of reusing waste glass from crushed containers and building demolition as aggregate for preparing mortars and concrete. At present, this kind of reuse is still not common due to the risk of alkali-silica reaction between the alkalis of cement and silica of the waste glass. This expansive reaction can cause great problems of cracking and, consequently, it can be extremely deleterious for the durability of mortar and concrete. However, data reported in the literature show that if the waste glass is finely ground, under 75mum, this effect does not occur and mortar durability is guaranteed. Therefore, in this work the possible reactivity of waste glass with the cement paste in mortars was verified, by varying the particle size of the finely ground waste glass. No reaction has been detected with particle size up to 100mum thus indicating the feasibility of the waste glass reuse as fine aggregate in mortars and concrete. In addition, waste glass seems to positively contribute to the mortar micro-structural properties resulting in an evident improvement of its mechanical performance.

Antimicrobial mortar surfaces for the improvement of hygienic conditions.

PubMed

De Muynck, W; De Belie, N; Verstraete, W

2010-01-01

To evaluate the effectiveness of various antimicrobial mortar formulations in inhibiting the growth of a selection of pathogens of environmental and hygienic concern. Mortar prisms containing triclosan-incorporated fibres or different concentrations of silver copper zeolites were incubated with Escherichia coli, Listeria monocytogenes, Salmonella enterica or Staphylococcus aureus at 4 or 20 degrees C for 24 h. From plate counting, a substantial bactericidal effect (>4 log units) could only be observed for the mortar specimens containing more than 3% zeolites on cement weight base, the effect being more pronounced at 20 degrees C compared to 4 degrees C. No inhibitory effect could be observed for mortar specimens containing antimicrobial fibres. Adenosinetriphosphate (ATP) measurements allowed for a rapid indication of the occurrence of antimicrobial activity. In order to obtain a bactericidal effect on mortar surfaces, concentrations of silver copper zeolites of more then 3% are required. To our knowledge, this is the first study in which the effectiveness of various antimicrobial mortar mixtures towards the inhibition of pathogens has been evaluated in a quantitative way. Antimicrobial concrete mixtures can be used for the improvement of the hygienic conditions in a variety of environments.

Drying Shrinkage of Mortar Incorporating High Volume Oil Palm Biomass Waste

NASA Astrophysics Data System (ADS)

Shukor Lim, Nor Hasanah Abdul; Samadi, Mostafa; Rahman Mohd. Sam, Abdul; Khalid, Nur Hafizah Abd; Nabilah Sarbini, Noor; Farhayu Ariffin, Nur; Warid Hussin, Mohd; Ismail, Mohammed A.

2018-03-01

This paper studies the drying shrinkage of mortar incorporating oil palm biomass waste including Palm Oil Fuel Ash, Oil Palm Kernel Shell and Oil Palm Fibre. Nano size of palm oil fuel ash was used up to 80 % as cement replacement by weight. The ash has been treated to improve the physical and chemical properties of mortar. The mass ratio of sand to blended ashes was 3:1. The test was carried out using 25 × 25 × 160 mm prism for drying shrinkage tests and 70 × 70 ×70 mm for compressive strength test. The results show that the shrinkage value of biomass mortar is reduced by 31% compared with OPC mortar thus, showing better performance in restraining deformation of the mortar while the compressive strength increased by 24% compared with OPC mortar at later age. The study gives a better understanding of how the biomass waste affect on mortar compressive strength and drying shrinkage behaviour. Overall, the oil palm biomass waste can be used to produce a better performance mortar at later age in terms of compressive strength and drying shrinkage.

Effect of Graphene Oxide on Mechanical Properties of Recycled Mortar

NASA Astrophysics Data System (ADS)

Fang, Changle; Long, Wujian; Wei, Jingjie; Xiao, Bingxu; Yan, Chen

2017-12-01

The use of recycled aggregate as replacement of natural aggregate has increased in recent years in order to reduce the high consumption of natural resources in construction industry. This paper presents an experimental investigation on the effect of graphene oxide (GO) on the mechanical properties of recycled mortar. It is showed that the recycled mortar with GO has a better mechanical properties than the recycled mortar without GO. Microstructural analysis of the recycled mortar with GO showed to have much denser and better crystallization of hydration product.

46. DETAIL VIEW OF THE MORTAR BOXES, STAMP BATTERIES AND ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

46. DETAIL VIEW OF THE MORTAR BOXES, STAMP BATTERIES AND AMALGAMATION TABLES. NOTE FULTON IRON WORKS, SAM FRANCISCO 1908 STAMPED INTO THE MORTAR BOX. ALSO NOTE THE DIES RESTING ON THE OUTSIDE OF THE MORTAR BOX BY THE SECOND STAMP BATTERY FROM THE CAMERA POSITION. - Standard Gold Mill, East of Bodie Creek, Northeast of Bodie, Bodie, Mono County, CA

Use of rubble from building demolition in mortars.

PubMed

Corinaldesi, V; Giuggiolini, M; Moriconi, G

2002-01-01

Because of increasing waste production and public concerns about the environment, it is desirable to recycle materials from building demolition. If suitably selected, ground, cleaned and sieved in appropriate industrial crushing plants, these materials can be profitably used in concrete. Nevertheless, the presence of masonry instead of concrete rubble is particularly detrimental to the mechanical performance and durability of recycled-aggregate concrete and the same negative effect is detectable when natural sand is replaced by fine recycled aggregate fraction. An alternative use of both masonry rubble and fine recycled material fraction could be in mortars. These could contain either recycled instead of natural sand or powder obtained by bricks crushing as partial cement substitution. In particular, attention is focused on the modification that takes place when either polypropylene or stainless steel fibers are added to these mortars. Polypropylene fibers are added in order to reduce shrinkage of mortars, stainless steel fibers for improving their flexural strength. The combined use of polypropylene fibers and fine recycled material from building demolition could allow the preparation of mortars showing good performance, in particular when coupled with bricks. Furthermore, the combined use of stainless steel fibers and mortars containing brick powder seems to be an effective way to guarantee a high flexural strength.

Properties of Cement Mortar Produced from Mixed Waste Materials with Pozzolanic Characteristics.

PubMed

Yen, Chi-Liang; Tseng, Dyi-Hwa; Wu, Yue-Ze

2012-07-01

Waste materials with pozzolanic characteristics, such as sewage sludge ash (SSA), coal combustion fly ash (FA), and granulated blast furnace slag (GBS), were reused as partial cement replacements for making cement mortar in this study. Experimental results revealed that with dual replacement of cement by SSA and GBS and triple replacement by SSA, FA, and GBS at 50% of total cement replacement, the compressive strength (Sc) of the blended cement mortars at 56 days was 93.7% and 92.9% of the control cement mortar, respectively. GBS had the highest strength activity index value and could produce large amounts of CaO to enhance the pozzolanic activity of SSA/FA and form calcium silicate hydrate gels to fill the capillary pores of the cement mortar. Consequently, the Sc development of cement mortar with GBS replacement was better than that without GBS, and the total pore volume of blended cement mortars with GBS/SSA replacement was less than that with FA/SSA replacement. In the cement mortar with modified SSA and GBS at 70% of total cement replacement, the Sc at 56 days was 92.4% of the control mortar. Modifying the content of calcium in SSA also increased its pozzolanic reaction. CaCl(2) accelerated the pozzolanic activity of SSA better than lime did. Moreover, blending cement mortars with GBS/SSA replacement could generate more monosulfoaluminate to fill capillary pores.

A Study of Array Direction HDPE Fiber Reinforced Mortar

NASA Astrophysics Data System (ADS)

Kamsuwan, Trithos

2018-02-01

This paper presents the effect of array direction HDPE fiber using as the reinforced material in cement mortar. The experimental data were created reference to the efficiency of using HDPE fiber reinforced on the tensile properties of cement mortar with different high drawn ratio of HDPE fibers. The fiber with the different drawn ratio 25x (d25 with E xx), and 35x (d35 with E xx) fiber volume fraction (0%, 1.0%, 1.5%) and fiber length 20 mm. were used to compare between random direction and array direction of HDPE fibers and the stress - strain displacement relationship behavior of HDPE short fiber reinforced cement mortar were investigated. It was found that the array direction with HDPE fibers show more improved in tensile strength and toughness when reinforced in cement mortar.

New System of Shrinkage Measurement through Cement Mortars Drying

PubMed Central

Morón, Carlos; Saiz, Pablo; Ferrández, Daniel; García-Fuentevilla, Luisa

2017-01-01

Cement mortar is used as a conglomerate in the majority of construction work. There are multiple variants of cement according to the type of aggregate used in its fabrication. One of the major problems that occurs while working with this type of material is the excessive loss of moisture during cement hydration (setting and hardening), known as shrinkage, which provokes a great number of construction pathologies that are difficult to repair. In this way, the design of a new sensor able to measure the moisture loss of mortars at different age levels is useful to establish long-term predictions concerning mortar mass volume loss. The purpose of this research is the design and fabrication of a new capacitive sensor able to measure the moisture of mortars and to relate it with the shrinkage. PMID:28272297

Study of sticky rice-lime mortar technology for the restoration of historical masonry construction.

PubMed

Yang, Fuwei; Zhang, Bingjian; Ma, Qinglin

2010-06-15

Replacing or repairing masonry mortar is usually necessary in the restoration of historical constructions, but the selection of a proper mortar is often problematic. An inappropriate choice can lead to failure of the restoration work, and perhaps even further damage. Thus, a thorough understanding of the original mortar technology and the fabrication of appropriate replacement materials are important research goals. Many kinds of materials have been used over the years in masonry mortars, and the technology has gradually evolved from the single-component mortar of ancient times to hybrid versions containing several ingredients. Beginning in 2450 BCE, lime was used as masonry mortar in Europe. In the Roman era, ground volcanic ash, brick powder, and ceramic chip were added to lime mortar, greatly improving performance. Because of its superior properties, the use of this hydraulic (that is, capable of setting underwater) mortar spread, and it was adopted throughout Europe and western Asia. Perhaps because of the absence of natural materials such as volcanic ash, hydraulic mortar technology was not developed in ancient China. However, a special inorganic-organic composite building material, sticky rice-lime mortar, was developed. This technology was extensively used in important buildings, such as tombs, in urban constructions, and even in water conservancy facilities. It may be the first widespread inorganic-organic composite mortar technology in China, or even in the world. In this Account, we discuss the origins, analysis, performance, and utility in historic preservation of sticky rice-lime mortar. Mortar samples from ancient constructions were analyzed by both chemical methods (including the iodine starch test and the acid attack experiment) and instrumental methods (including thermogravimetric differential scanning calorimetry, X-ray diffraction, Fourier transform infrared, and scanning electron microscopy). These analytical results show that the ancient masonry

Luminescence quartz dating of lime mortars. A first research approach.

PubMed

Zacharias, N; Mauz, B; Michael, C T

2002-01-01

Lime mortars mixed with sand are well suited for connecting structural materials, like stones and bricks, due to the mechanical properties this material exhibits. Their extensive use in architectural and decorative works during the last 4000 years motivated the introduction of the 'Luminescence clock' for age determination of mortars. The same principles as for quartz optically stimulated luminescence (OSL) dating of sediments were applied for age estimation of a mortar fragment removed from a Byzantine church monument dated by archaeological means to 1050-1100 years ago (the first half of the 10th century). The OSL from the quartz was monitored under blue light stimulation and UV detection, using a single-aliquot-regenerative-dose protocol. The quartz-OSL dating of the mortar resulted in 870 +/- 230 a. TL polymineral fine grain dating was also performed on a brick fragment which was connected to the mortar, resulting in a TL age of 1095 +/- 190 a.

NMR relaxometry study of plaster mortar with polymer additives

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

Jumate, E.; Manea, D.; Moldovan, D.

2013-11-13

The cement mixed with water forms a plastic paste or slurry which stiffness in time and finally hardens into a resistant stone. The addition of sand aggregates, polymers (Walocel) and/or calcium carbonate will modify dramatically the final mortar mechanic and thermal properties. The hydration processes can be observed using the 1D NMR measurements of transverse T{sub 2} relaxation times distributions analysed by a Laplace inversion algorithm. These distributions were obtained for mortar pasta measured at 2 hours after preparation then at 3, 7 and 28 days after preparation. Multiple components are identified in the T{sub 2} distributions. These can bemore » associated with the proton bounded chemical or physical to the mortar minerals characterized by a short T{sub 2} relaxation time and to water protons in pores with three different pore sizes as observed from SEM images. The evaporation process is faster in the first hours after preparation, while the mortar hydration (bonding of water molecules to mortar minerals) can be still observed after days or months from preparation. Finally, the mechanic resistance was correlated with the transverse T{sub 2} relaxation rates corresponding to the bound water.« less

NMR relaxometry study of plaster mortar with polymer additives

NASA Astrophysics Data System (ADS)

Jumate, E.; Moldovan, D.; Fechete, R.; Manea, D.

2013-11-01

The cement mixed with water forms a plastic paste or slurry which stiffness in time and finally hardens into a resistant stone. The addition of sand aggregates, polymers (Walocel) and/or calcium carbonate will modify dramatically the final mortar mechanic and thermal properties. The hydration processes can be observed using the 1D NMR measurements of transverse T2 relaxation times distributions analysed by a Laplace inversion algorithm. These distributions were obtained for mortar pasta measured at 2 hours after preparation then at 3, 7 and 28 days after preparation. Multiple components are identified in the T2 distributions. These can be associated with the proton bounded chemical or physical to the mortar minerals characterized by a short T2 relaxation time and to water protons in pores with three different pore sizes as observed from SEM images. The evaporation process is faster in the first hours after preparation, while the mortar hydration (bonding of water molecules to mortar minerals) can be still observed after days or months from preparation. Finally, the mechanic resistance was correlated with the transverse T2 relaxation rates corresponding to the bound water.

Properties of Cement Mortar Produced from Mixed Waste Materials with Pozzolanic Characteristics

PubMed Central

Yen, Chi-Liang; Tseng, Dyi-Hwa; Wu, Yue-Ze

2012-01-01

Abstract Waste materials with pozzolanic characteristics, such as sewage sludge ash (SSA), coal combustion fly ash (FA), and granulated blast furnace slag (GBS), were reused as partial cement replacements for making cement mortar in this study. Experimental results revealed that with dual replacement of cement by SSA and GBS and triple replacement by SSA, FA, and GBS at 50% of total cement replacement, the compressive strength (Sc) of the blended cement mortars at 56 days was 93.7% and 92.9% of the control cement mortar, respectively. GBS had the highest strength activity index value and could produce large amounts of CaO to enhance the pozzolanic activity of SSA/FA and form calcium silicate hydrate gels to fill the capillary pores of the cement mortar. Consequently, the Sc development of cement mortar with GBS replacement was better than that without GBS, and the total pore volume of blended cement mortars with GBS/SSA replacement was less than that with FA/SSA replacement. In the cement mortar with modified SSA and GBS at 70% of total cement replacement, the Sc at 56 days was 92.4% of the control mortar. Modifying the content of calcium in SSA also increased its pozzolanic reaction. CaCl2 accelerated the pozzolanic activity of SSA better than lime did. Moreover, blending cement mortars with GBS/SSA replacement could generate more monosulfoaluminate to fill capillary pores. PMID:22783062

Effect of nylon fiber on mechanical properties of cement based mortar

NASA Astrophysics Data System (ADS)

Hanif, I. M.; Syuhaili, M. R. Noor; Hasmori, M. F.; Shahmi, S. M.

2017-11-01

An investigation has been carried out to study the effect of nylon fiber on the mechanical properties of cement based mortar after receiving large quantities of nylon waste. Subsequently, this research was conducted to compare the compressive, tensile and flexural strength of normal cement based mortar with nylon fiber cement based mortar. All samples using constant water-cement ratio of 0.63 and three different percentages of nylon fiber were added in the mixture during the samples preparation period which consists of 0.5%, 1.5% and 2.5% by total weight of cement based mortar. The results obtained with different nylon percentage marked an increases in compressive strength (up to 17%), tensile strength (up to 21%) and flexural strength (up to 13%) when compared with control cement based mortar samples. Therefore, the results obtained from this study shows that by using nylon fiber as additive material can improve the mechanical properties of the cement based mortar and at the same time produce a good sustainable product that can protects and conserve the marine environment.

Effect of chitosan ethers on fresh state properties of lime mortars

NASA Astrophysics Data System (ADS)

Vyšvařil, M.; Žižlavský, T.

2017-10-01

The fresh state properties of mortars are eminently important since determine the material workability and also have a great influence on its hardened state characteristics. In this paper, the behaviour of fresh lime mortars modified by etherified derivatives of chitosan (hydroxypropylchitosan (HPCH) and carboxymethylchitosan (CMCH)) is assessed with the purpose of exploring a new application of such derivatives as lime mortar admixtures. The rheological parameters (relative yield stress, consistency coefficient and fluidity index) and viscoelastic properties were correlated with flow table tests, relative density measurements, water retention abilities of mortars and air content in mortars. Results were seen to be strongly dependent on substituents of the chitosan. Non-ionic derivative (HPCH) had a plasticizing influence on the mortars; the ionic CMCH showed the thickening effect. The effect of chitosan ethers was found to be dosage-dependent. CMCH had low impact on water retention, while HPCH displayed high water retention capability. It was concluded, that the ionic derivative (CMCH) is very similar by its viscosity enhancing effect to starch ether.

Chloride Ion Adsorption Capacity of Anion Exchange Resin in Cement Mortar

PubMed Central

Lee, Hanseung; Jung, Dohyun; Chen, Zhengxin

2018-01-01

This paper presents the effect of anion exchange resin (AER) on the adsorption of chloride ions in cement mortar. The kinetic and equilibrium behaviors of AER were investigated in distilled water and Ca(OH)2 saturated solutions, and then the adsorption of chloride ions by the AER in the mortar specimen was determined. The AER was used as a partial replacement for sand in the mortar specimen. The mortar specimen was coated with epoxy, except for an exposed surface, and then immersed in a NaCl solution for 140 days. The chloride content in the mortar specimen was characterized by energy dispersive X-ray fluorescence analysis and electron probe microanalysis. The results showed that the AER could adsorb the chloride ions from the solution rapidly but had a relatively low performance when the pH of its surrounding environment increased. When the AER was mixed in the cement mortar, its chloride content was higher than that of the cement matrix around it, which confirms the chloride ion adsorption capacity of the AER. PMID:29621188

Chloride Ion Adsorption Capacity of Anion Exchange Resin in Cement Mortar.

PubMed

Lee, Yunsu; Lee, Hanseung; Jung, Dohyun; Chen, Zhengxin; Lim, Seungmin

2018-04-05

This paper presents the effect of anion exchange resin (AER) on the adsorption of chloride ions in cement mortar. The kinetic and equilibrium behaviors of AER were investigated in distilled water and Ca(OH)₂ saturated solutions, and then the adsorption of chloride ions by the AER in the mortar specimen was determined. The AER was used as a partial replacement for sand in the mortar specimen. The mortar specimen was coated with epoxy, except for an exposed surface, and then immersed in a NaCl solution for 140 days. The chloride content in the mortar specimen was characterized by energy dispersive X-ray fluorescence analysis and electron probe microanalysis. The results showed that the AER could adsorb the chloride ions from the solution rapidly but had a relatively low performance when the pH of its surrounding environment increased. When the AER was mixed in the cement mortar, its chloride content was higher than that of the cement matrix around it, which confirms the chloride ion adsorption capacity of the AER.

Effect of Graphene Oxide on the Damping Capability of Recycled Mortar

NASA Astrophysics Data System (ADS)

Wei, Jing-Jie; Long, Wu-Jian; Fang, Chang-Le; Li, Hao-Dao; Guo, Yue-Gui

2018-03-01

The use of recycled aggregate as replacement of natural aggregate has increased in recent years in order to reduce the high consumption of natural resources in construction industry. This paper presents an experimental investigation on the effect of graphene oxide (GO) on the damping capability of recycled mortar. The effect of GO on damping capability was examined by using dynamic mechanical analyzer (DMA), It is showed that the recycled mortar with GO has a better damping capability than the recycled mortar without GO. Microstructural analysis of the recycled mortar with GO showed to have much denser and better crystallization of hydration products.

Improvements of nano-SiO2 on sludge/fly ash mortar.

PubMed

Lin, D F; Lin, K L; Chang, W C; Luo, H L; Cai, M Q

2008-01-01

Sewage sludge ash has been widely applied to cementitious materials. In this study, in order to determine effects of nano-SiO(2) additives on properties of sludge/fly ash mortar, different amounts of nano-SiO(2) were added to sludge/fly ash mortar specimens to investigate their physical properties and micro-structures. A water-binding ratio of 0.7 was assigned to the mix. Substitution amounts of 0%, 10%, 20%, and 30% of sludge/fly ash (1:1 ratio) were proposed. Moreover, 0%, 1%, 2%, and 3% of nano-SiO(2) was added to the mix. Tests, including SEM and compressive strength, were carried out on mortar specimens cured at 3, 7, and 28 days. Results showed that sludge/fly ash can make the crystals of cement hydration product finer. Moreover, crystals increased after nano-SiO(2) was added. Hence, nano-SiO(2) can improve the effects of sludge/fly ash on the hydration of mortar. Further, due to the low pozzolanic reaction active index of sludge ash, early compressive strengths of sludge/fly ash mortar were decreased. Yet, nano-SiO(2) could help produce hydration crystals, which implies that the addition of nano-SiO(2) to mortar can improve the influence of sludge/fly ash on the development of the early strength of the mortar.

Mortar radiocarbon dating: preliminary accuracy evaluation of a novel methodology.

PubMed

Marzaioli, Fabio; Lubritto, Carmine; Nonni, Sara; Passariello, Isabella; Capano, Manuela; Terrasi, Filippo

2011-03-15

Mortars represent a class of building and art materials that are widespread at archeological sites from the Neolithic period on. After about 50 years of experimentation, the possibility to evaluate their absolute chronology by means of radiocarbon ((14)C) remains still uncertain. With the use of a simplified mortar production process in the laboratory environment, this study shows the overall feasibility of a novel physical pretreatment for the isolation of the atmospheric (14)CO(2) (i.e., binder) signal absorbed by the mortars during their setting. This methodology is based on the assumption that an ultrasonic attack in liquid phase isolates a suspension of binder carbonates from bulk mortars. Isotopic ((13)C and (14)C), % C, X-ray diffractometry (XRD), and scanning electron microscopy (SEM) analyses were performed to characterize the proposed methodology. The applied protocol allows suppression of the fossil carbon (C) contamination originating from the incomplete burning of the limestone during the quick lime production, providing unbiased dating for "laboratory" mortars produced operating at historically adopted burning temperatures.

Influence of aggregate type and chemical admixtures on frost resistance of lightweight mortars

NASA Astrophysics Data System (ADS)

Klimek, Beata; Widomski, Marcin K.; Barnat-Hunek, Danuta

2017-07-01

The aim of studies presented in this paper covered analyses of type of lightweight aggregate as well as aeration and hydrophobic admixtures influence on absorbability and frost resistance of heat-insulating mortars applied in the energy-efficient construction. In the presented research, expanded perlite (EP) and expanded clay aggregate (ceramsite) were used as lightweight aggregates. The measurements of the basic mechanical and physical characteristics of tested mortars were performed, including, inter alia, compressive and flexural tensile strength, density, effective (open) and total porosity, absorbability, thermal conductivity as well as frost resistance after 25 cycles of freezing and thawing. Substitution of some part of sand fraction by the lightweight aggregates, expanded clay aggregate or perlite, resulted in changes in physical properties of the tested mortars. The observed decrease in density (specific weight), coefficient of heat transport and strength parameters were simultaneously accompanied by the increase in absorbability. Researches concerning frost resistance of mortars containing ceramsite and perlite showed the improved frost resistance of mortar utilizing perlite. Most of the tested mortars shoved satisfactory frost resistance, only samples of mortar containing ceramsite and aeration admixture were destroyed. The significant influence of aerating admixture on frost resistance of mortars was determined. Hydrophobic siloxanes addition failed to adequately protect the mortars against frost erosion, regardless the type of applied aggregate.

Properties of wastepaper sludge in geopolymer mortars for masonry applications.

PubMed

Yan, Shiqin; Sagoe-Crentsil, Kwesi

2012-12-15

This paper presents the results of an investigation into the use of wastepaper sludge in geopolymer mortar systems for manufacturing construction products. The investigation was driven by the increasing demand for reuse options in paper-recycling industry. Both fresh and hardened geopolymer mortar properties are evaluated for samples incorporating dry wastepaper sludge, and the results indicate potential end-use benefits in building product manufacture. Addition of wastepaper sludge to geopolymer mortar reduces flow properties, primarily due to dry sludge absorbing water from the binder mix. The average 91-day compressive strength of mortar samples incorporating 2.5 wt% and 10 wt% wastepaper sludge respectively retained 92% and 52% of the reference mortar strength. However, contrary to the normal trend of increasing drying shrinkage with increasing paper sludge addition to Portland cement matrices, the corresponding geopolymer drying shrinkage decreased by 34% and 64%. Equally important, the water absorption of hardened geopolymer mortar decreased with increasing paper sludge content at ambient temperatures, providing good prospects of overall potential for wastepaper sludge incorporation in the production of building and masonry elements. The results indicate that, despite its high moisture absorbance due to the organic matter and residual cellulose fibre content, wastepaper sludge appears compatible with geopolymer chemistry, and hence serves as a potential supplementary additive to geopolymer cementitious masonry products. Copyright © 2012 Elsevier Ltd. All rights reserved.

Modification of Lime Mortars with Synthesized Aluminosilicates

NASA Astrophysics Data System (ADS)

Loganina, Valentina I.; Sadovnikova, Marija E.; Jezierski, Walery; Małaszkiewicz, Dorota

2017-10-01

The increasing attention for restoration of buildings of historical and architectural importance has increased the interest for lime-based binders, which could be applied for manufacturing repair mortars and plasters compatible with historical heritage. Different additives, admixtures or fibers may be incorporated to improve mechanical and thermal features of such materials. In this study synthesized aluminosilicates (SA) were applied as an additive for lime mortar. The technology of synthesis consisted in the deposition of aluminosilicates from a sodium liquid glass by the aluminum sulphate Al2(SO4)3. The goal of this investigation was developing a new method of aluminosilicates synthesis from a sodium liquid glass and using this new material as a component for a lime mortar. Aluminosilicates were precipitated from the solution of aluminum sulphate Al2(SO)3 and sodium silicate. SA were then used as an additive to calcareous compositions and their influence was tested. Mortars were prepared with commercial air lime and siliceous river sand. Air lime binder was replaced by 5 and 10 wt.% of SA. Calcareous composition specimens were formed at water/lime ratio 1.0. The following analyses were made: grain size distribution of SA, X-ray diffraction analysis (XRD), sorption properties, plastic strength and compressive strength of lime mortars. XRD pattern of the SA shows the presence of thenardite, gibbsite and amorphous phase represented by aggregate of nano-size cristobalite-like crystallites. Application of SA leads to increase of compressive strength after 90 days of hardening by 28% and 53% at SA content 5 and 10% respectively comparing to specimens without this additive. Contents of chemically bound lime in the reference specimens after 28 days of hardening in air-dry conditions was 46.5%, while in specimens modified with SA contained 50.0-55.3% of bound lime depending on filtrate pH. This testifies to high activity of calcareous composition. The new blended lime

Experimental Investigation of Multi-mode Fiber Laser Cutting of Cement Mortar.

PubMed

Lee, Dongkyoung; Pyo, Sukhoon

2018-02-10

This study successfully applied multi-mode laser cutting with the variation of the laser cutting speed to cement mortar for the first time. The effects of the amount of silica sand in the cement mortar on laser cutting are tested and analyzed. The kerf width and penetration depth of the specimens after laser cutting are investigated. As the laser cutting speed increases, the penetration depth decreases for both cement paste and cement mortar, whereas the kerf width becomes saturated and increases, respectively, for cement paste and cement mortar. Cross sections of the specimens are compared with illustrations. Top-view images of the cement mortar with indicators of the physical characteristics, such as re-solidification, burning, and cracks are examined, and the possible causes of these characteristics are explained. The optical absorption rates of cement-based materials are quantified at wide ranges of wavelength to compare the absorption rates in accordance with the materials compositions. The chemical composition variation before and after laser cutting is also compared by EDX (Energy Dispersive X-Ray) analysis. In addition to these observations, material removal mechanisms for cement mortar are proposed.

Experimental Investigation of Multi-mode Fiber Laser Cutting of Cement Mortar

PubMed Central

2018-01-01

This study successfully applied multi-mode laser cutting with the variation of the laser cutting speed to cement mortar for the first time. The effects of the amount of silica sand in the cement mortar on laser cutting are tested and analyzed. The kerf width and penetration depth of the specimens after laser cutting are investigated. As the laser cutting speed increases, the penetration depth decreases for both cement paste and cement mortar, whereas the kerf width becomes saturated and increases, respectively, for cement paste and cement mortar. Cross sections of the specimens are compared with illustrations. Top-view images of the cement mortar with indicators of the physical characteristics, such as re-solidification, burning, and cracks are examined, and the possible causes of these characteristics are explained. The optical absorption rates of cement-based materials are quantified at wide ranges of wavelength to compare the absorption rates in accordance with the materials compositions. The chemical composition variation before and after laser cutting is also compared by EDX (Energy Dispersive X-Ray) analysis. In addition to these observations, material removal mechanisms for cement mortar are proposed. PMID:29439431

Continuous monitoring of setting and hardening of mortar using FBG sensors

NASA Astrophysics Data System (ADS)

Lima, H.; Ribeiro, R.; Nogueira, R.; Silva, L.; Abe, I.; Pinto, J. L.

2007-05-01

The use of fibre Bragg grating sensors to study mortars' dimensional variations during the setting process is reported. When determining a mortar's potential to fissure, it's important to know its total retraction. This means it is necessary to know not only the mortar's retraction after hardened, but also to know how much it retracts during the plastic phase. This work presents a technique which allows to measure dimensional variations, either expansion or retraction, during the whole setting process. Temperature and strain evolution during both plastic and hardened phase of the mortar were obtained, allowing the determination of dimensional variations and setting times. Due to its high-speed, ease of implementation and low operation costs, this technique will allow to get a deeper knowledge of the effects of several additives on the mortar's behaviour, allowing to improve its mechanical properties through the determination of the proper chemical composition.

A chemometric approach to the characterisation of historical mortars

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

Rampazzi, L.; Pozzi, A.; Sansonetti, A.

2006-06-15

The compositional knowledge of historical mortars is of great concern in case of provenance and dating investigations and of conservation works since the nature of the raw materials suggests the most compatible conservation products. The classic characterisation usually goes through various analytical determinations, while conservation laboratories call for simple and quick analyses able to enlighten the nature of mortars, usually in terms of the binder fraction. A chemometric approach to the matter is here undertaken. Specimens of mortars were prepared with calcitic and dolomitic binders and analysed by Atomic Spectroscopy. Principal Components Analysis (PCA) was used to investigate the featuresmore » of specimens and samples. A Partial Least Square (PLS1) regression was done in order to predict the binder/aggregate ratio. The model was applied to historical mortars from the churches of St. Lorenzo (Milan) and St. Abbondio (Como). The accordance between the predictive model and the real samples is discussed.« less

Low Carbon Footprint mortar from Pozzolanic Waste Material

NASA Astrophysics Data System (ADS)

Mehmannavaz, Taha; Mehman navaz, Hossein Ali; Moayed Zefreh, Fereshteh; Aboata, Zahra

2017-04-01

Nowadays, Portland cement clinker leads to emission of CO2 into the atmosphere and therefore causes greenhouse effect. Incorporating of Palm Oil Fuel Ash (POFA) and Pulverized Fuel Ash (PFA) as partial cement replacement materials into mix of low carbon mortar decreases the amount of cement use and reduces high dependence on cements compared to ordinary mortar. The result of this research supported use of the new concept in preparing low carbon mortar for industrial constructions. Strength of low carbon mortar with POFA and PFA replacement in cement was affected and changed by replacing percent finesse, physical and chemical properties and pozzolanic activity of these wastes. Waste material replacement instead of Ordinary Portland Cement (OPC) was used in this study. This in turn was useful for promoting better quality of construction and innovative systems in construction industry, especially in Malaysia. This study was surely a step forward to achieving quality products which were affordable, durable and environmentally friendly. Disposing ash contributes to shortage of landfill space in Malaysia. Besides, hazard of ash might be another serious issue for human health. The ash disposal area also might create a new problem, which is the area's sedimentation and erosion.

Ancient mortars from Cape Verde: mineralogical and physical characterization

NASA Astrophysics Data System (ADS)

Rocha, Fernando; Costa, Cristiana; Velosa, Ana; Quintela, Ana; Terroso, Denise; Marques, Vera

2014-05-01

Times and locations of different building constructions means different knowledge, habits, different construction methods and materials. The study and safeguarding of the architectural heritage takes nowadays a progressive importance as a vehicle for transmission of cultures and history of nations. The coatings are of great importance in the durability of a building due to the protective role of the masonry. The compatibility between the materials with which they are executed (masonry, mortar and grout settlement) promotes the proper functioning of the wall and a consequent increase in durability. Therefore, it becomes important to study and characterize the mortar coating of buildings to know its characteristics and to use compatible materials in the rehabilitation and maintenance of buildings. This study aims to characterize the chemical, physical, mechanical and mineralogical mortar samples collected in buildings in three islands of Cape Verde, for the conservation, rehabilitation and preservation of them. The collected samples belong to buildings constructed in the end of XIX century and in the beginning of XX century. In order to characterize the mortar samples some tests was made, such as X-Ray Diffraction, X- Ray Fluorescence, acid attack and mechanical strength. The samples were divided into three groups depending on origin; so we have a first group collected on the island of Santiago, the second on the island of Saint Vincent and the third on the island of Santo Antao. The samples are all carbonated, but Santiago samples have a lower carbonates content. In terms of insoluble residue (from the acid attack) it was concluded that the samples have similar value ranging from 9 to 26%. The compressive strength of the mortars have a range between 1.36 and 4.55 MPa, which is related to the presence of more binder in samples with higher resistance. The chemical and mineralogical analyzes showed that these consist of lime mortars (binder), natural pozzolan and

Flight qualification of mortar-actuated parachute deployment systems

NASA Technical Reports Server (NTRS)

Pleasants, J. E.

1975-01-01

A brief discussion outlines background of mortar use in parachute deployment systems. A description of the system operation is presented. Effects of the environment on performance are discussed as well as the instrumentation needed to assess this performance. Power unit qualification and lot qualification for shear pins and cartridges is delineated. Functional mortar system tests are described. Finally, bridle deployment and parachute deployment are discussed.

Modeling of Carbon Mortar Color Expression Using Artificial Neural Network.

PubMed

Jang, Hong-Seok; Kim, Ju-Hee; Shuli, Xing; So, Seung-Young

2018-09-01

Colored concrete uses pigments and white Portland cement (WPC) to perform decorative functions together with structural function. Pigments are used in permanent coloring of concrete with colors different from the natural color of the cement or the aggregates with mixing WPC. In this study, an artificial neural networks study was carried out to predict the color evaluation of black mortar using pigment and carbon black. A data set of a laboratory work, in which a total of 9 mortars were produced, was utilized in the Artificial Neural Networks (ANNs) study. The mortar mixture parameters were nine different pigment and carbon black ratios. Each mortar was measured at ten locations on the surface and averaged. Color can be evaluated by measurements of tristimulus values L* , a* and b* , represented in the chromatic space CIELAB. The L* value is a measure of luminosity (0 darkness), from completely opaque (0) to completely transparent (100); a* is a measure of redness (-a* greenness) and b* of yellowness (-b* blueness). ANN model is constructed, trained and tested using these data. The data used in the ANN model are arranged in a format of three input parameters that cover the pigment, carbon black and WPC and, an output parameter which is the color parameters of the black colored mortar. The results showed that ANN can be an alternative approach for the predicting the color parameters using mortar ingredients as input parameters.

Artillery/mortar type classification based on detected acoustic transients

NASA Astrophysics Data System (ADS)

Morcos, Amir; Grasing, David; Desai, Sachi

2008-04-01

Feature extraction methods based on the statistical analysis of the change in event pressure levels over a period and the level of ambient pressure excitation facilitate the development of a robust classification algorithm. The features reliably discriminates mortar and artillery variants via acoustic signals produced during the launch events. Utilizing acoustic sensors to exploit the sound waveform generated from the blast for the identification of mortar and artillery variants as type A, etcetera through analysis of the waveform. Distinct characteristics arise within the different mortar/artillery variants because varying HE mortar payloads and related charges emphasize varying size events at launch. The waveform holds various harmonic properties distinct to a given mortar/artillery variant that through advanced signal processing and data mining techniques can employed to classify a given type. The skewness and other statistical processing techniques are used to extract the predominant components from the acoustic signatures at ranges exceeding 3000m. Exploiting these techniques will help develop a feature set highly independent of range, providing discrimination based on acoustic elements of the blast wave. Highly reliable discrimination will be achieved with a feed-forward neural network classifier trained on a feature space derived from the distribution of statistical coefficients, frequency spectrum, and higher frequency details found within different energy bands. The processes that are described herein extend current technologies, which emphasis acoustic sensor systems to provide such situational awareness.

Utilization of ground waste seashells in cement mortars for masonry and plastering.

PubMed

Lertwattanaruk, Pusit; Makul, Natt; Siripattarapravat, Chalothorn

2012-11-30

In this research, four types of waste seashells, including short-necked clam, green mussel, oyster, and cockle, were investigated experimentally to develop a cement product for masonry and plastering. The parameters studied included water demand, setting time, compressive strength, drying shrinkage and thermal conductivity of the mortars. These properties were compared with those of a control mortar that was made of a conventional Portland cement. The main parameter of this study was the proportion of ground seashells used as cement replacement (5%, 10%, 15%, or 20% by weight). Incorporation of ground seashells resulted in reduced water demand and extended setting times of the mortars, which are advantages for rendering and plastering in hot climates. All mortars containing ground seashells yielded adequate strength, less shrinkage with drying and lower thermal conductivity compared to the conventional cement. The results indicate that ground seashells can be applied as a cement replacement in mortar mixes and may improve the workability of rendering and plastering mortar. Copyright © 2012 Elsevier Ltd. All rights reserved.

Reuse of de-inking sludge from wastepaper recycling in cement mortar products.

PubMed

Yan, Shiqin; Sagoe-Crentsil, Kwesi; Shapiro, Gretta

2011-08-01

This paper presents results of an investigation into the use of de-inking sludge from a paper recycling mill as feedstock material in the manufacture of cement mortar products, including masonry blocks and mortar renders. Both physical and mechanical properties of mortar specimens containing various amounts of de-inking sludge were investigated. It was observed that the addition of de-inking sludge to cement mortar at a fixed water-to-cement ratio significantly reduced flow properties and increased setting time. Water absorption and volume of permeable voids of cement mortar increased with increased dosage of de-inking sludge, with a corresponding reduction of bulk density. The 91-day compressive strength of mortar samples with 2.5 wt% and 20 wt% de-inking sludge loadings retained 83% and 62% respectively of the reference mortar strength. The corresponding drying shrinkage increased by up to 160% compared to reference samples. However, a de-inking sludge loading of up to 2.5 wt% did not significantly alter measured physical and mechanical properties. The results demonstrate that despite the high moisture absorbance of de-inking sludge due to its organic matter and residual cellulose fibre content, it serves as a potential supplementary additive and its cellulosic content proving to be an active set retardant to cementitious masonry products. Copyright © 2011 Elsevier Ltd. All rights reserved.

Effect of some biotic factors on microbially-induced calcite precipitation in cement mortar.

PubMed

Al-Salloum, Yousef; Abbas, H; Sheikh, Q I; Hadi, S; Alsayed, Saleh; Almusallam, Tarek

2017-02-01

Sporosarcina pasteurii , a common soil bacterium has been tested for microbial treatment of cement mortar. The present study also seeks to investigate the effects of growth medium, bacterial concentration and different buffers concerning the preparation of bacterial suspensions on the compressive strength of cement mortar. Two growth media, six different suspensions and two bacterial concentrations were used in the study. The influence of growth medium on calcification efficiency of S. pasteurii was insignificant. Significant improvement in the compressive as well as the tensile strength of cement mortar was observed. Microbial mineral precipitation visualized by Scanning Electron Microscopy (SEM) shows fibrous material that increased the strength of cement mortar. Formation of thin strands of fillers observed through SEM micrographs improves the pore structure, impermeability and thus the compressive as well as the tensile strengths of the cement mortar. The type of substrate and its molarity have a significant influence on the strength of cement mortar.

The dynamic behavior of mortar under impact-loading

NASA Astrophysics Data System (ADS)

Kawai, Nobuaki; Inoue, Kenji; Misawa, Satoshi; Tanaka, Kyoji; Hayashi, Shizuo; Kondo, Ken-Ichi; Riedel, Werner

2007-06-01

Concrete and mortar are the most fundamental structural material. Therefore, considerable interest in characterizing the dynamic behavior of them under impact-loading exists. In this study, plate impact experiments have been performed to determine the dynamic behavior of mortar. Longitudinal and lateral stresses have been directly measured by means of embedded polyvinylidene fluoride (PVDF) gauges up to 1 GPa. A 200 mm-cal. powder gun enable us to measure longitudinal and lateral stresses at several point from the impact surface, simultaneously. The shear strength under impact-loading has been obtained from measured longitudinal and lateral stresses. The longitudinal stress profile shows a two-wave structure. It is indicated that this structure is associated with the onset of pore compaction and failure of mortar by comparing with hydrocode simulations using an elastic-plastic damage model for concrete.

Concretes and mortars with waste paper industry: Biomass ash and dregs.

PubMed

Martínez-Lage, Isabel; Velay-Lizancos, Miriam; Vázquez-Burgo, Pablo; Rivas-Fernández, Marcos; Vázquez-Herrero, Cristina; Ramírez-Rodríguez, Antonio; Martín-Cano, Miguel

2016-10-01

This article describes a study on the viability of using waste from the paper industry: biomass boiler ash and green liquor dregs to fabricate mortars and concretes. Both types of ash were characterized by obtaining their chemical and mineralogical composition, their organic matter content, granulometry, adsorption and other common tests for construction materials. Seven different mortars were fabricated, one for reference made up of cement, sand, and water, three in which 10, 20, or 30% of the cement was replaced by biomass ash, and three others in which 10, 20, or 30% of the cement was replaced with dregs. Test specimens were fabricated with these mortars to conduct flexural and compression tests. Flexural strength is reduced for all the mortars studied. Compressive strength increases for the mortars fabricated with biomass ash and decreases for the mortar with dregs. Finally, 5 concretes were made, one of them as a reference (neither biomass ash nor dregs added), two of them with replacements of 10 and 20% of biomass ash instead of cement and another two with replacements of 10 and 20% of dregs instead of cement. The compressive and tensile splitting strength increase when a 10% of ash is replaced and decrease in all the other cases. The modulus of elasticity always decreases. Copyright © 2016 Elsevier Ltd. All rights reserved.

Comparison of analytical tools appropriate for identification of proteinaceous additives in historical mortars.

PubMed

Krizova, Iva; Schultz, Julia; Nemec, Ivan; Cabala, Radomir; Hynek, Radovan; Kuckova, Stepanka

2018-01-01

Natural organic additives such as eggs, lard, resins, and oils have been added to mortars since ancient times, because the ancient builders knew of their positive effect on the mortar quality. The tradition of adding organic materials to mortars was commonly handed down only verbally for thousands years. However, this practice disappeared in the nineteenth century, when the usage of modern materials started. Today, one of the most recent topics in the industry of building materials is the reusing of natural organic materials and searching for the forgotten ancient recipes. The research of the old technological approaches involves currently the most advanced analytical techniques and methods. This paper is focussed on testing the possibility of identification of proteinaceous additives in historical mortars and model mortar samples containing blood, bone glue, curd, eggs and gelatine, by Fourier transform infrared (FTIR) and Raman spectroscopy, gas chromatography - mass spectrometry (GC-MS), matrix-assisted laser desorption/ionisation-time of flight mass spectrometry (MALDI-TOF MS), liquid chromatography-electrospray ionisation-quadrupole-time of flight mass spectrometry (LC-ESI-Q-TOF MS) and enzyme-linked immunosorbent assay (ELISA). All these methods were applied to the mortar sample taken from the interior of the medieval (sixteenth century) castle in Namest nad Oslavou in the Czech Republic and their comparison contributed to the rough estimation of the protein additive content in the mortar. The obtained results demonstrate that only LC-ESI-Q-TOF MS, MALDI-TOF MS and ELISA have the sufficiently low detection limits that enable the reliable identification of collagens in historical mortars. Graphical abstract Proteomics analyses of historical mortars.

Influence of Chloride-Ion Adsorption Agent on Chloride Ions in Concrete and Mortar.

PubMed

Peng, Gai-Fei; Feng, Nai-Qian; Song, Qi-Ming

2014-04-30

The influence of a chloride-ion adsorption agent (Cl agent in short), composed of zeolite, calcium aluminate hydrate and calcium nitrite, on the ingress of chloride ions into concrete and mortar has been experimentally studied. The permeability of concrete was measured, and the chloride ion content in mortar was tested. The experimental results reveal that the Cl agent could adsorb chloride ions effectively, which had penetrated into concrete and mortar. When the Cl agent was used at a dosage of 6% by mass of cementitious materials in mortar, the resistance to the penetration of chloride ions could be improved greatly, which was more pronounced when a combination of the Cl agent and fly ash or slag was employed. Such an effect is not the result of the low permeability of the mortar, but might be a result of the interaction between the Cl agent and the chloride ions penetrated into the mortar. There are two possible mechanisms for the interaction between the Cl agent and chloride ion ingress. One is the reaction between calcium aluminate hydrate in the Cl agent and chloride ions to form Friedel's salt, and the other one is that calcium aluminate hydrate reacts with calcium nitrite to form AFm during the early-age hydration of mortar and later the NO₂ - in AFm is replaced by chloride ions, which then penetrate into the mortar, also forming Friedel's salt. More research is needed to confirm the mechanisms.

Influence of Chloride-Ion Adsorption Agent on Chloride Ions in Concrete and Mortar

PubMed Central

Peng, Gai-Fei; Feng, Nai-Qian; Song, Qi-Ming

2014-01-01

The influence of a chloride-ion adsorption agent (Cl agent in short), composed of zeolite, calcium aluminate hydrate and calcium nitrite, on the ingress of chloride ions into concrete and mortar has been experimentally studied. The permeability of concrete was measured, and the chloride ion content in mortar was tested. The experimental results reveal that the Cl agent could adsorb chloride ions effectively, which had penetrated into concrete and mortar. When the Cl agent was used at a dosage of 6% by mass of cementitious materials in mortar, the resistance to the penetration of chloride ions could be improved greatly, which was more pronounced when a combination of the Cl agent and fly ash or slag was employed. Such an effect is not the result of the low permeability of the mortar, but might be a result of the interaction between the Cl agent and the chloride ions penetrated into the mortar. There are two possible mechanisms for the interaction between the Cl agent and chloride ion ingress. One is the reaction between calcium aluminate hydrate in the Cl agent and chloride ions to form Friedel’s salt, and the other one is that calcium aluminate hydrate reacts with calcium nitrite to form AFm during the early-age hydration of mortar and later the NO2− in AFm is replaced by chloride ions, which then penetrate into the mortar, also forming Friedel’s salt. More research is needed to confirm the mechanisms. PMID:28788625

Corrosion Sensor for Monitoring the Service Condition of Chloride-Contaminated Cement Mortar

PubMed Central

Lu, Shuang; Ba, Heng-Jing

2010-01-01

A corrosion sensor for monitoring the corrosion state of cover mortar was developed. The sensor was tested in cement mortar, with and without the addition of chloride to simulate the adverse effects of chloride-contaminated environmental conditions on concrete structures. In brief, a linear polarization resistance method combined with an embeddable reference electrode was utilized to measure the polarization resistance (Rp) using built-in sensor electrodes. Subsequently, electrochemical impedance spectroscopy in the frequency range of 1 kHz to 50 kHz was used to obtain the cement mortar resistance (Rs). The results show that the polarization resistance is related to the chloride content and Rs; ln (Rp) is linearly related to the Rs values in mortar without added chloride. The relationships observed between the Rp of the steel anodes and the resistance of the surrounding cement mortar measured by the corrosion sensor confirms that Rs can indicate the corrosion state of concrete structures. PMID:22319347

Corrosion sensor for monitoring the service condition of chloride-contaminated cement mortar.

PubMed

Lu, Shuang; Ba, Heng-Jing

2010-01-01

A corrosion sensor for monitoring the corrosion state of cover mortar was developed. The sensor was tested in cement mortar, with and without the addition of chloride to simulate the adverse effects of chloride-contaminated environmental conditions on concrete structures. In brief, a linear polarization resistance method combined with an embeddable reference electrode was utilized to measure the polarization resistance (Rp) using built-in sensor electrodes. Subsequently, electrochemical impedance spectroscopy in the frequency range of 1 kHz to 50 kHz was used to obtain the cement mortar resistance (Rs). The results show that the polarization resistance is related to the chloride content and Rs; ln (Rp) is linearly related to the Rs values in mortar without added chloride. The relationships observed between the Rp of the steel anodes and the resistance of the surrounding cement mortar measured by the corrosion sensor confirms that Rs can indicate the corrosion state of concrete structures.

Recycling red mud from the production of aluminium as a red cement-based mortar.

PubMed

Yang, Xiaojie; Zhao, Jianfeng; Li, Haoxin; Zhao, Piqi; Chen, Qin

2017-05-01

Current management for red mud is insufficient and a new method is needed. A series of experiments have been carried out to develop a new approach for effective management of red mud. Mortars without or with 3%, 6% and 9% red mud were prepared and their fresh and hardened properties were measured to access the possibility of recycling the red mud in the production of red cement-based mortar. The mechanisms corresponding to their mechanical performance variations were explored by X-ray powder diffraction and scanning electron microscopy. The results show that the fresh mortars with red mud present an increase of viscosity as compared with the control. However, little difference is found when the content of red mud is altered. It also can be seen that red mud increases flow time and reduces the slump flow of the mortar. Meanwhile, it is found that mortar with red mud is provided with higher air content. Red mud is eligible to adjust the decorative mortar colour. Compressive strength of mortar is improved when less than 6% red mud is added. However, overall it has a slightly negative effect on tensile bond strength. It decreases the Ca(OH) 2 content and densifies the microstructure of hardened paste. The heavy metal concentrations in leachates of mortars with red mud are much lower than the values required in the standard, and it will not do harm to people's health and the environment. These results are important to recycle and effectively manage red mud via the production of red cement-based mortar.

Lime-pozzolana mortars in Roman catacombs: composition, structures and restoration

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

Sanchez-Moral, Sergio; Luque, Luis; Canaveras, Juan-Carlos

Analyses of microsamples collected from Roman catacombs and samples of lime-pozzolana mortars hardened in the laboratory display higher contents in carbonated binder than other subaerial Roman monuments. The measured environmental data inside the Saint Callistus and Domitilla catacombs show a constant temperature of 15-17 deg C, a high CO{sub 2} content (1700 to 3500 ppm) and a relative humidity close to 100%. These conditions and particularly the high CO{sub 2} concentration speed-up the lime calcitization roughly by 500% and reduce the cationic diffusion to form hydrous calcium aluminosilicates. The structure of Roman catacomb mortars shows (i) coarser aggregates and thickermore » beds on the inside, (ii) thin, smoothed, light and fine-grained external surfaces with low content of aggregates and (iii) paintings and frescoes on the outside. The observed high porosity of the mortars can be attributed to cracking after drying linked with the high binder content. Hardened lime lumps inside the binder denote low water/mortar ratios for slaking. The aggregate tephra pyroclasts rich in aluminosilicate phases with accessorial amounts of Ba, Sr, Rb, Cu and Pb were analysed through X-ray diffraction (XRD), electron microprobe analysis (EMPA) and also by environmental scanning electron microscopy (ESEM) to identify the size and distribution of porosity. Results support procedures using local materials, special mortars and classic techniques for restoration purposes in hypogeal backgrounds.« less

Artillery/mortar round type classification to increase system situational awareness

NASA Astrophysics Data System (ADS)

Desai, Sachi; Grasing, David; Morcos, Amir; Hohil, Myron

2008-04-01

Feature extraction methods based on the statistical analysis of the change in event pressure levels over a period and the level of ambient pressure excitation facilitate the development of a robust classification algorithm. The features reliably discriminates mortar and artillery variants via acoustic signals produced during the launch events. Utilizing acoustic sensors to exploit the sound waveform generated from the blast for the identification of mortar and artillery variants as type A, etcetera through analysis of the waveform. Distinct characteristics arise within the different mortar/artillery variants because varying HE mortar payloads and related charges emphasize varying size events at launch. The waveform holds various harmonic properties distinct to a given mortar/artillery variant that through advanced signal processing and data mining techniques can employed to classify a given type. The skewness and other statistical processing techniques are used to extract the predominant components from the acoustic signatures at ranges exceeding 3000m. Exploiting these techniques will help develop a feature set highly independent of range, providing discrimination based on acoustic elements of the blast wave. Highly reliable discrimination will be achieved with a feedforward neural network classifier trained on a feature space derived from the distribution of statistical coefficients, frequency spectrum, and higher frequency details found within different energy bands. The processes that are described herein extend current technologies, which emphasis acoustic sensor systems to provide such situational awareness.

Durability of Waste Glass Flax Fiber Reinforced Mortar

NASA Astrophysics Data System (ADS)

Aly, M.; Hashmi, M. S. J.; Olabi, A. G.; Messeiry, M.

2011-01-01

The main concern for natural fibre reinforced mortar composites is the durability of the fibres in the alkaline environment of cement. The composites may undergo a reduction in strength as a result of weakening of the fibres by a combination of alkali attack and fibre mineralisation. In order to enhance the durability of natural fiber reinforced cement composites several approaches have been studied including fiber impregnation, sealing of the matrix pore system and reduction of matrix alkalinity through the use of pozzolanic materials. In this study waste glass powder was used as a pozzolanic additive to improve the durability performance of flax fiber reinforced mortar (FFRM). The durability of the FFRM was studied by determining the effects of ageing in water and exposure to wetting and drying cycles; on the microstructures and flexural behaviour of the composites. The mortar tests demonstrated that the waste glass powder has significant effect on improving the durability of FFRM.

Durability of waste glass flax fiber reinforced mortar

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

Aly, M.; Hashmi, M. S. J.; Olabi, A. G.

2011-01-17

The main concern for natural fibre reinforced mortar composites is the durability of the fibres in the alkaline environment of cement. The composites may undergo a reduction in strength as a result of weakening of the fibres by a combination of alkali attack and fibre mineralisation. In order to enhance the durability of natural fiber reinforced cement composites several approaches have been studied including fiber impregnation, sealing of the matrix pore system and reduction of matrix alkalinity through the use of pozzolanic materials. In this study waste glass powder was used as a pozzolanic additive to improve the durability performancemore » of flax fiber reinforced mortar (FFRM). The durability of the FFRM was studied by determining the effects of ageing in water and exposure to wetting and drying cycles; on the microstructures and flexural behaviour of the composites. The mortar tests demonstrated that the waste glass powder has significant effect on improving the durability of FFRM.« less

Use of waste brick as a partial replacement of cement in mortar.

PubMed

Naceri, Abdelghani; Hamina, Makhloufi Chikouche

2009-08-01

The aim of this study is to investigate the use of waste brick as a partial replacement for cement in the production of cement mortar. Clinker was replaced by waste brick in different proportions (0%, 5%, 10%, 15% and 20%) by weight for cement. The physico-chemical properties of cement at anhydrous state and the hydrated state, thus the mechanical strengths (flexural and compressive strengths after 7, 28 and 90 days) for the mortar were studied. The microstructure of the mortar was investigated using scanning electron microscopy (SEM), the mineralogical composition (mineral phases) of the artificial pozzolan was investigated by the X-ray diffraction (XRD) and the particle size distributions was obtained from laser granulometry (LG) of cements powders used in this study. The results obtained show that the addition of artificial pozzolan improves the grinding time and setting times of the cement, thus the mechanical characteristics of mortar. A substitution of cement by 10% of waste brick increased mechanical strengths of mortar. The results of the investigation confirmed the potential use of this waste material to produce pozzolanic cement.

Amination of black liquor and the application in the ready-mixed wet mortar.

PubMed

Zheng, Dafeng; Zheng, Tao; Chen, Ran; Li, Xiaokang; Qiu, Xueqing

2018-01-01

In order to extend the application of black liquor (BL), amino group was introduced in lignin through Mannich reaction. The structure of the aminated black liquor (ABL) was characterized with FT-IR, elemental analysis, the zeta potential and the inherent viscosity. The foam generated by ABL was more stable, for the surface tension was lower. The results of the mortar test indicated that the water-retention rate of the fresh mortar incorporated with 0.3 wt% ABL was 89.1%; the consistency loss was about 39.7% after 4 h. When the dosage was less than 0.3 wt%, ABL could increase the bond strength of the hardened mortars. The results showed that ABL could be used as an effective ready-mixed wet mortar admixture. This study not only provided a new method to develop new mortar admixture, but also alleviated the pollution of BL.

Influence of recycled fine aggregates on the resistance of mortars to magnesium sulfate attack

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

Lee, Seung-Tae

2009-08-15

The influence of recycled fine aggregates, which had been reclaimed from field-demolished concretes, on the resistance of mortar specimens to magnesium sulfate attack was investigated. Mortar specimens were prepared with recycled fine aggregates at different replacement levels (0%, 25%, 50%, 75% and 100% of natural fine aggregate by mass). The mortar specimens were exposed to 4.24% magnesium sulfate solution for about 1 year at ambient temperature, and regularly monitored for visual appearance, compressive strength loss and expansion. Additionally, in order to identify products of magnesium sulfate attack, mortar samples incorporating 0%, 25% and 100% replacement levels of the recycled finemore » aggregates were examined by X-ray diffraction (XRD) technique. Experimental results confirmed that the use of recycled fine aggregates up to a maximum 50% replacement level is effective under severe magnesium sulfate environment, irrespective of type of recycled fine aggregates. However, the worse performance was observed in mortar specimens incorporating 100% replacement level. It was found that the water absorption of recycled fine aggregates affected deterioration of mortar specimens, especially at a higher replacement level. XRD results indicated that the main cause of deterioration of the mortar specimens was primarily due to the formation of gypsum and thaumasite by magnesium sulfate attack. In addition, it appeared that the conversion of C-S-H into M-S-H by the attack probably influenced mechanical deterioration of mortar specimens with recycled fine aggregates.« less

Combined Effects of Non-Conforming Fly Ash and Recycled Masonry Aggregates on Mortar Properties

PubMed Central

Torres-Gómez, Ana Isabel; Ledesma, Enrique F.; Otero, Rocio; Fernández, José Maria; Jiménez, José Ramón; de Brito, Jorge

2016-01-01

This work evaluates the effects of using non-conforming fly ash (Nc-FA) generated in a thermoelectric power plant as filler material for mortars made with natural sand (NA) and recycled sand from masonry waste (FRMA). The incorporation of powdered recycled masonry filler (R-MF) is also tested as an alternative to siliceous filler (Si-F). Three families of mortars were designed to study: the effect of replacing Si-F with Nc-FA on mortars made with NA; the effect of replacing Si-F with Nc-FA on mortars made with 50% of NA and 50% of FRMA; and the effect of replacing Si-F with R-MF on mortars made with NA and FRMA. Replacing Si-F with Nc-FA is a viable alternative that increases the mechanical strength, the workability and durability properties and decreases the shrinkage. The use of FRMA and Nc-FA improved the mechanical strength of mortars, and it slightly increased the shrinkage. The replacement of Si-F with R-MF on mortars made with FRMA is not a good alternative, because it has a negative impact on all of the properties tested. This work can help both to reduce cement and natural resources’ consumption and to increase the recycling rate of Nc-FA and FRMA. PMID:28773849

Combined Effects of Non-Conforming Fly Ash and Recycled Masonry Aggregates on Mortar Properties.

PubMed

Torres-Gómez, Ana Isabel; Ledesma, Enrique F; Otero, Rocio; Fernández, José Maria; Jiménez, José Ramón; de Brito, Jorge

2016-08-25

This work evaluates the effects of using non-conforming fly ash (Nc-FA) generated in a thermoelectric power plant as filler material for mortars made with natural sand (NA) and recycled sand from masonry waste (FRMA). The incorporation of powdered recycled masonry filler (R-MF) is also tested as an alternative to siliceous filler (Si-F). Three families of mortars were designed to study: the effect of replacing Si-F with Nc-FA on mortars made with NA; the effect of replacing Si-F with Nc-FA on mortars made with 50% of NA and 50% of FRMA; and the effect of replacing Si-F with R-MF on mortars made with NA and FRMA. Replacing Si-F with Nc-FA is a viable alternative that increases the mechanical strength, the workability and durability properties and decreases the shrinkage. The use of FRMA and Nc-FA improved the mechanical strength of mortars, and it slightly increased the shrinkage. The replacement of Si-F with R-MF on mortars made with FRMA is not a good alternative, because it has a negative impact on all of the properties tested. This work can help both to reduce cement and natural resources' consumption and to increase the recycling rate of Nc-FA and FRMA.

Biopolymers to improve physical properties and leaching characteristics of mortar and concrete: A review

NASA Astrophysics Data System (ADS)

Olivia, M.; Jingga, H.; Toni, N.; Wibisono, G.

2018-04-01

The invention of environmentally friendly, high performance, and green material such as biopolymers marked an emerging trend for sustainable construction over the past decades. Biopolymer comprises of natural monomers and synthesized by plants or other organisms. The sustainable, biodegradable, and renewable biopolymers were used in concrete mixes to improve their physical and mechanical properties and durability. The aim of this paper is to provide a brief an overview of the impact of biopolymer addition into concrete and mortar mixes. Many studies on the influence of biopolymer on the properties of concrete and mortar by adding biopolymers at a certain proportion (usually less than one wt.%) to the concrete or mortar mixes, and the heavy metal leaching, rheological, and mechanical properties of the mixes were conducted. Biopolymers included in this review are chitosan (CH), xanthan gum (XG), guar gum (GG), lignosulphonate (LS), and cellulose ethers (CE). Data from previous studies showed that the addition of certain types of biopolymer into concrete and mortar mixes improve workability, water retention, and compressive strength by up to 30 percent. Chitosan strengthens heavy metal encapsulation in the mortar and neutralizes the negative impact of heavy metal on the mortar properties and environment. To sum up, the use of biopolymers improve physical properties and leaching characteristics of mortar and concrete.

Characterization of Incorporation the Glass Waste in Adhesive Mortar

NASA Astrophysics Data System (ADS)

Santos, D. P.; Azevedo, A. R. G.; Hespanhol, R. L.; Alexandre, J.

Ehe search for reuse generated waste in urban centers, intending to preserve natural resources, has remained fairly constant, both in context of preventing exploitation of resources as the emplacement of waste on the environment. Glass waste glass created a serious environmental problem, mainly because of inconsistency of its flows. Ehe use of this product as a mineral additive, finely ground, cement replacement and aggregate is a promising direction for recycling. This work aims to study the influence of glass waste from cutting process in adhesive mortar, replacing part of cement. Ehe glass powder is used replacing Portland cement at 10, 15 and 20% by mass. Ehe produced mortars will be evaluated its performance in fresh and hardened states through tests performed in laboratory. Ehe selected feature is indicated by producers of additive and researchers to present good results when used as adhesive mortar.

Effects of surfactants on the properties of mortar containing styrene/methacrylate superplasticizer.

PubMed

Negim, El-Sayed; Kozhamzharova, Latipa; Khatib, Jamal; Bekbayeva, Lyazzat; Williams, Craig

2014-01-01

The physical and mechanical properties of mortar containing synthetic cosurfactants as air entraining agent are investigated. The cosurfactants consist of a combination of 2% dodecyl benzene sodium sulfonate (DBSS) and either 1.5% polyvinyl alcohol (PVA) or 1.5% polyoxyethylene glycol monomethyl ether (POE). Also these cosurfactants were used to prepare copolymers latex: styrene/butyl methacrylate (St/BuMA), styrene/methyl methacrylate (St/MMA), and styrene/glycidyl methacrylate (St/GMA), in order to study their effects on the properties of mortar. The properties of mortar examined included flow table, W/C ratio, setting time, water absorption, compressive strength, and combined water. The results indicate that the latex causes improvement in mortar properties compared with cosurfactants. Also polymer latex containing DBSS/POE is more effective than that containing DBSS/PVA.

Effects of Surfactants on the Properties of Mortar Containing Styrene/Methacrylate Superplasticizer

PubMed Central

Negim, El-Sayed; Kozhamzharova, Latipa; Khatib, Jamal; Bekbayeva, Lyazzat; Williams, Craig

2014-01-01

The physical and mechanical properties of mortar containing synthetic cosurfactants as air entraining agent are investigated. The cosurfactants consist of a combination of 2% dodecyl benzene sodium sulfonate (DBSS) and either 1.5% polyvinyl alcohol (PVA) or 1.5% polyoxyethylene glycol monomethyl ether (POE). Also these cosurfactants were used to prepare copolymers latex: styrene/butyl methacrylate (St/BuMA), styrene/methyl methacrylate (St/MMA), and styrene/glycidyl methacrylate (St/GMA), in order to study their effects on the properties of mortar. The properties of mortar examined included flow table, W/C ratio, setting time, water absorption, compressive strength, and combined water. The results indicate that the latex causes improvement in mortar properties compared with cosurfactants. Also polymer latex containing DBSS/POE is more effective than that containing DBSS/PVA. PMID:24955426

Tracing formation and durability of calcite in a Punic-Roman cistern mortar (Pantelleria Island, Italy).

PubMed

Dietzel, Martin; Schön, Frerich; Heinrichs, Jens; Deditius, Artur P; Leis, Albrecht

2016-01-01

Ancient hydraulic lime mortar preserves chemical and isotopic signatures that provide important information about historical processing and its durability. The distribution and isotopic composition of calcite in a mortar of a well-preserved Punic-Roman cistern at Pantelleria Island (Italy) was used to trace the formation conditions, durability, and individual processing periods of the cistern mortar. The analyses of stable carbon and oxygen isotopes of calcite revealed four individual horizons, D, E, B-1 and B-2, of mortar from the top to the bottom of the cistern floor. Volcanic and ceramic aggregates were used for the production of the mortar of horizons E/D and B-1/B-2, respectively. All horizons comprise hydraulic lime mortar characterized by a mean cementation index of 1.5 ± 1, and a constant binder to aggregate ratio of 0.31 ± 0.01. This suggests standardized and highly effective processing of the cistern. The high durability of calcite formed during carbonation of slaked lime within the matrix of the ancient mortar, and thus the excellent resistance of the hydraulic lime mortar against water, was documented by (i) a distinct positive correlation of δ(18)Ocalcite and δ(13)Ccalcite; typical for carbonation through a mortar horizon, (ii) a characteristic evolution of δ(18)Ocalcite and δ(13)Ccalcite through each of the four mortar horizons; lighter follow heavier isotopic values from upper to lower part of the cistern floor, and (iii) δ(18)Ocalcite varying from -10 to -5 ‰ Vienna Pee Dee belemnite (VPDB). The range of δ(18)Ocalcite values rule out recrystallization and/or neoformation of calcite through chemical attack of water stored in cistern. The combined studies of the chemical composition of the binder and the isotopic composition of the calcite in an ancient mortar provide powerful tools for elucidating the ancient techniques and processing periods. This approach helps to evaluate the durability of primary calcite and demonstrates the

Metal Patch Antenna

NASA Technical Reports Server (NTRS)

Chamberlain, Neil F. (Inventor); Zawadzki, Mark S. (Inventor); Hodges, Richard E. (Inventor)

2012-01-01

Disclosed herein is a patch antenna comprises a planar conductive patch attached to a ground plane by a support member, and a probe connector in electrical communication with the conductive patch arranged to conduct electromagnetic energy to or from the conductive patch, wherein the conductive patch is disposed essentially parallel to the ground plane and is separated from the ground plane by a spacing distance; wherein the support member comprises a plurality of sides disposed about a central axis oriented perpendicular to the conductive patch and the ground plane; wherein the conductive patch is solely supported above the ground plane by the support member; and wherein the support member provides electrical communication between the planer conductive patch and the ground plane.

Properties of mortars made by uncalcined FGD gypsum-fly ash-ground granulated blast furnace slag composite binder

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

Zhong Shiyun, E-mail: tjzhongshiyun@163.com; Ni Kun; Li Jinmei

2012-07-15

Highlights: Black-Right-Pointing-Pointer The mortar with uncalcined FGD gypsum has suitable workability. Black-Right-Pointing-Pointer The strength of mortar with uncalcined FGD gypsum is higher than that of mortar without uncalcined FGD gypsum. Black-Right-Pointing-Pointer The dry shrinkage of mortar with uncalcined FGD gypsum is lower than that of mortar without uncalcined FGD gypsum. Black-Right-Pointing-Pointer The leaching of sulfate ion of mortar is studied. - Abstract: A series of novel mortars were developed from composite binder of uncalcined FGD gypsum, fly ash (FA) and ground granulated blast furnace slag (GGBFS) for the good utilization of flue gas desulphurization (FGD) gypsum. At a fixed ratiomore » (20%) of GGBFS to the composite binder, keeping consistency of the mortar between 9.5 and 10.0 cm, the properties of the composite mortar were studied. The results show that higher water/binder (W/B) is required to keep the consistency when increasing the percentage of FGD gypsum. No obvious influences of the W/B and content of FGD gypsum on the bleeding of paste were observed which keeps lower than 2% under all experimental conditions tried. The highest compressive and flexural strengths (ratio is 20% FGD gypsum, 20% GGBFS and 60% FA) are 22.6 and 4.3 MPa at 28 days, respectively. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) results indicate that massive ettringite crystals and C-S-H gels exist in the hydration products. At 90 days the mortars with FGD gypsum is dramatically smaller drying shrinkage (563-938 micro strain) than that without FGD gypsum (about 2250 micro strain). The release of the SO{sub 4}{sup 2-} from the mortar was analyzed, indicating that the dissolution of sulfate increases with FGD gypsum. The concentration of SO{sub 4}{sup 2-} releasing from the mortar with 10% FGD gypsum is almost equal to that obtained from the mortar without FGD gypsum. The release of SO{sub 4}{sup 2-} from the mortar with 20% FGD gypsum is

Analysis of main parameters affecting substrate/mortar contact area through tridimensional laser scanner.

PubMed

Stolz, Carina M; Masuero, Angela B

2015-10-01

This study assesses the influence of the granulometric composition of sand, application energy and the superficial tension of substrates on the contact area of rendering mortars. Three substrates with distinct wetting behaviors were selected and mortars were prepared with different sand compositions. Characterization tests were performed on fresh and hardened mortars, as well as the rheological characterization. Mortars were applied to substrates with two different energies. The interfacial area was then digitized with 3D scanner. Results show that variables are all of influence on the interfacial contact in the development area. Furthermore, 3D laser scanning proved to be a good method to contact area measurement. Copyright © 2015 Elsevier Inc. All rights reserved.

Influence of pore structure on compressive strength of cement mortar.

PubMed

Zhao, Haitao; Xiao, Qi; Huang, Donghui; Zhang, Shiping

2014-01-01

This paper describes an experimental investigation into the pore structure of cement mortar using mercury porosimeter. Ordinary Portland cement, manufactured sand, and natural sand were used. The porosity of the manufactured sand mortar is higher than that of natural sand at the same mix proportion; on the contrary, the probable pore size and threshold radius of manufactured sand mortar are finer. Besides, the probable pore size and threshold radius increased with increasing water to cement ratio and sand to cement ratio. In addition, the existing models of pore size distribution of cement-based materials have been reviewed and compared with test results in this paper. Finally, the extended Bhattacharjee model was built to examine the relationship between compressive strength and pore structure.

Influence of Pore Structure on Compressive Strength of Cement Mortar

PubMed Central

Zhao, Haitao; Xiao, Qi; Huang, Donghui

2014-01-01

This paper describes an experimental investigation into the pore structure of cement mortar using mercury porosimeter. Ordinary Portland cement, manufactured sand, and natural sand were used. The porosity of the manufactured sand mortar is higher than that of natural sand at the same mix proportion; on the contrary, the probable pore size and threshold radius of manufactured sand mortar are finer. Besides, the probable pore size and threshold radius increased with increasing water to cement ratio and sand to cement ratio. In addition, the existing models of pore size distribution of cement-based materials have been reviewed and compared with test results in this paper. Finally, the extended Bhattacharjee model was built to examine the relationship between compressive strength and pore structure. PMID:24757414

Alternative design of pipe sleeve for liquid removal mechanism in mortar slab layer

NASA Astrophysics Data System (ADS)

Nazri, W. M. H. Wan; Anting, N.; Lim, A. J. M. S.; Prasetijo, J.; Shahidan, S.; Din, M. F. Md; Anuar, M. A. Mohd

2017-11-01

Porosity is one of the mortar’s characteristics that can cause problems, especially in the room space that used high amount of water, such as bathrooms. Waterproofing is one of the technology that normally used to minimize this problem which is preventing deep penetration of liquid water or moisture into underlying concrete layers. However, without the proper mechanism to remove liquid water and moisture from mortar system, waterproofing layer tends to be damaged after a long period of time by the static formation of liquid water and moisture at mortar layer. Thus, a solution has been proposed to drain out water that penetrated into the mortar layer. This paper introduces a new solution using a Modified Pipe Sleeve (MPS) that installed at the mortar layer. The MPS has been designed considering the percentage surface area of the pipe sleeve that having contact with mortar layer (2%, 4%, 6%, 8% and 10%) with angle of holes of 60°. Infiltration test and flow rate test have been conducted to identify the effectiveness of the MPS in order to drain out liquid water or moisture from the mortar layer. In this study shows that, MPS surface area 10%, angled 60°, function effectively as a water removal compared to other design.

Immobilization in cement mortar of chromium removed from water using titania nanoparticles.

PubMed

Husnain, Ahmed; Qazi, Ishtiaq Ahmed; Khaliq, Wasim; Arshad, Muhammad

2016-05-01

Because of the high toxicity of chromium, particularly as Cr (VI), it is removed from industrial effluents before their discharge into water bodies by a variety of techniques, including adsorption. Ultimate disposal of the sludge or the adsorbate, however, is a serious problem. While titania, in nanoparticle form, serves as a very good adsorbent for chromium, as an additive, it also helps to increase the compressive strength of mortar and concrete. Combining these two properties of the material, titania nanoparticles were used to adsorb chromium and then added to mortar up to a concentration of 20% by weight. The compressive strength of the resulting mortar specimens that replaced 15% of cement with chromium laden titania showed an improved strength than that without titania, thus confirming that this material had positive effect on the mortar strength. Leachate tests using the Toxicity Characteristics Leaching Procedure (TCLP) confirmed that the mortar sample chromium leachate was well within the permissible limits. The proposed technique thus offers a safe and viable method for the ultimate disposal of toxic metal wastes, in general, and those laden waste chromium, in particular. Copyright © 2016 Elsevier Ltd. All rights reserved.

Mechanical Properties of Epoxy Resin Mortar with Sand Washing Waste as Filler.

PubMed

Yemam, Dinberu Molla; Kim, Baek-Joong; Moon, Ji-Yeon; Yi, Chongku

2017-02-28

The objective of this study was to investigate the potential use of sand washing waste as filler for epoxy resin mortar. The mechanical properties of four series of mortars containing epoxy binder at 10, 15, 20, and 25 wt. % mixed with sand blended with sand washing waste filler in the range of 0-20 wt. % were examined. The compressive and flexural strength increased with the increase in epoxy and filler content; however, above epoxy 20 wt. %, slight change was seen in strength due to increase in epoxy and filler content. Modulus of elasticity also linearly increased with the increase in filler content, but the use of epoxy content beyond 20 wt. % decreased the modulus of elasticity of the mortar. For epoxy content at 10 wt. %, poor bond strength lower than 0.8 MPa was observed, and adding filler at 20 wt. % adversely affected the bond strength, in contrast to the mortars containing epoxy at 15, 20, 25 wt. %. The results indicate that the sand washing waste can be used as potential filler for epoxy resin mortar to obtain better mechanical properties by adding the optimum level of sand washing waste filler.

Use of waste brick as a partial replacement of cement in mortar

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

Naceri, Abdelghani; Hamina, Makhloufi Chikouche

2009-08-15

The aim of this study is to investigate the use of waste brick as a partial replacement for cement in the production of cement mortar. Clinker was replaced by waste brick in different proportions (0%, 5%, 10%, 15% and 20%) by weight for cement. The physico-chemical properties of cement at anhydrous state and the hydrated state, thus the mechanical strengths (flexural and compressive strengths after 7, 28 and 90 days) for the mortar were studied. The microstructure of the mortar was investigated using scanning electron microscopy (SEM), the mineralogical composition (mineral phases) of the artificial pozzolan was investigated by themore » X-ray diffraction (XRD) and the particle size distributions was obtained from laser granulometry (LG) of cements powders used in this study. The results obtained show that the addition of artificial pozzolan improves the grinding time and setting times of the cement, thus the mechanical characteristics of mortar. A substitution of cement by 10% of waste brick increased mechanical strengths of mortar. The results of the investigation confirmed the potential use of this waste material to produce pozzolanic cement.« less

Mechanical Properties of Epoxy Resin Mortar with Sand Washing Waste as Filler

PubMed Central

Yemam, Dinberu Molla; Kim, Baek-Joong; Moon, Ji-Yeon; Yi, Chongku

2017-01-01

The objective of this study was to investigate the potential use of sand washing waste as filler for epoxy resin mortar. The mechanical properties of four series of mortars containing epoxy binder at 10, 15, 20, and 25 wt. % mixed with sand blended with sand washing waste filler in the range of 0–20 wt. % were examined. The compressive and flexural strength increased with the increase in epoxy and filler content; however, above epoxy 20 wt. %, slight change was seen in strength due to increase in epoxy and filler content. Modulus of elasticity also linearly increased with the increase in filler content, but the use of epoxy content beyond 20 wt. % decreased the modulus of elasticity of the mortar. For epoxy content at 10 wt. %, poor bond strength lower than 0.8 MPa was observed, and adding filler at 20 wt. % adversely affected the bond strength, in contrast to the mortars containing epoxy at 15, 20, 25 wt. %. The results indicate that the sand washing waste can be used as potential filler for epoxy resin mortar to obtain better mechanical properties by adding the optimum level of sand washing waste filler. PMID:28772603

A mortar formulation including viscoelastic layers for vibration analysis

NASA Astrophysics Data System (ADS)

Paolini, Alexander; Kollmannsberger, Stefan; Rank, Ernst; Horger, Thomas; Wohlmuth, Barbara

2018-05-01

In order to reduce the transfer of sound and vibrations in structures such as timber buildings, thin elastomer layers can be embedded between their components. The influence of these elastomers on the response of the structures in the low frequency range can be determined accurately by using conforming hexahedral finite elements. Three-dimensional mesh generation, however, is yet a non-trivial task and mesh refinements which may be necessary at the junctions can cause a high computational effort. One remedy is to mesh the components independently from each other and to couple them using the mortar method. Further, the hexahedral mesh for the thin elastomer layer itself can be avoided by integrating its elastic behavior into the mortar formulation. The present paper extends this mortar formulation to take damping into account such that frequency response analyses can be performed more accurately. Finally, the proposed method is verified by numerical examples.

Resistance of biofilm-covered mortars to microbiologically influenced deterioration simulated by sulfuric acid exposure

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

Soleimani, Sahar, E-mail: ssoleima@connect.carleton.ca; Isgor, O. Burkan, E-mail: burkan_isgor@carleton.ca; Ormeci, Banu, E-mail: banu_ormeci@carleton.ca

2013-11-15

Following the reported success of biofilm applications on metal surfaces to inhibit microbiologically influenced corrosion, effectiveness and sustainability of E. coli DH5α biofilm on mortar surface to prevent microbiologically influenced concrete deterioration (MICD) are investigated. Experiments simulating microbial attack were carried out by exposing incrementally biofilm-covered mortar specimens to sulfuric acid solutions with pH ranging from 3 to 6. Results showed that calcium concentration in control reactors without biofilm was 23–47% higher than the reactors with biofilm-covered mortar. Formation of amorphous silica gel as an indication of early stages of acid attack was observed only on the control mortar specimensmore » without biofilm. During acidification, the biofilm continued to grow and its thickness almost doubled from ∼ 30 μm before acidification to ∼ 60 μm after acidification. These results demonstrated that E. coli DH5α biofilm was able to provide a protective and sustainable barrier on mortar surfaces against medium to strong sulfuric acid attack. -- Highlights: •Effectiveness of E.coli DH5α biofilm to prevent MICD was studied. •Conditions that lead to MICD were simulated by chemical acidification. •Biofilm-covered mortar specimens were exposed to sulfuric acid solutions. •The presence of biofilm helped reduce the chemically-induced mortar deterioration. •Biofilm remained alive and continued to grow during the acidification process.« less

Plastic shrinkage of mortars with shrinkage reducing admixture and lightweight aggregates studied by neutron tomography

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

Wyrzykowski, Mateusz, E-mail: mateusz.wyrzykowski@empa.ch; Lodz University of Technology, Department of Building Physics and Building Materials, Lodz; Trtik, Pavel

2015-07-15

Water transport in fresh, highly permeable concrete and rapid water evaporation from the concrete surface during the first few hours after placement are the key parameters influencing plastic shrinkage cracking. In this work, neutron tomography was used to determine both the water loss from the concrete surface due to evaporation and the redistribution of fluid that occurs in fresh mortars exposed to external drying. In addition to the reference mortar with a water to cement ratio (w/c) of 0.30, a mortar with the addition of pre-wetted lightweight aggregates (LWA) and a mortar with a shrinkage reducing admixture (SRA) were tested.more » The addition of SRA reduced the evaporation rate from the mortar at the initial stages of drying and reduced the total water loss. The pre-wetted LWA released a large part of the absorbed water as a consequence of capillary pressure developing in the fresh mortar due to evaporation.« less

The potential use of silica sand as nanomaterials for mortar

NASA Astrophysics Data System (ADS)

Setiati, N. Retno

2017-11-01

The development of nanotechnology is currently experiencing rapid growth. The use of the term nanotechnology is widely applied in areas such as healthcare, industrial, pharmaceutical, informatics, or construction. By the nanotechnology in the field of concrete construction, especially the mechanical properties of concrete are expected to be better than conventional concrete. This study aims to determine the effect of the potential of silica sand as a nanomaterial that is added into the concrete mix The methodology used consist of nanomaterial synthesis process of silica sand using Liquid Polishing Milling Technology (PLMT). The XRF and XRD testing were conducted to determine the composition of silica contained in the silica sand and the level of reactivity of the compound when added into the concrete mix. To determine the effect of nano silica on mortar, then made the specimen with size 50 mm x 50 mm x 50 mm. The composition of mortar is made in two variations, ie by the addition of 3% nano silica and without the addition of nanosilica. To know the mechanical properties of mortar, it is done testing of mortar compressive strength at the age of 28 days. Based on the analysis and evaluation, it is shown that compounds of silica sand in Indonesia, especially Papua reached more than 99% SiO2 and so that the amorphous character of silica sand can be used as a nanomaterial for concrete construction. The results of mechanical tests show that there is an increase of 12% compressive strength of mortar that is added with 3% nano silica.

Properties of Cement Mortar by Use of Hot-Melt Polyamides as Substitute for Fine Aggregate

PubMed Central

Yuan, Xiongzhou; Xu, Weiting; Sun, Wei; Xing, Feng; Wang, Weilun

2015-01-01

This paper presents an experimental study on use of hot-melt polyamide (HMP) to prepare mortar specimens with improved crack healing and engineering properties. The role of HMP in the crack repairing of cement mortar subjected to several rounds of heat treatment was investigated. Compatibility between HMP and hydraulic cement was investigated through X-ray diffraction (XRD) and Fourier transform infrared spectra (FTIR) technology. Mortar specimens were prepared using standard cement mortar mixes with HMP at 1%, 3% and 5% (by volume) for fine aggregate substitute. After curing for 28 days, HMP specimens were subjected to heating at temperature of 160 °C for one, two, and three days and then natural cooling down to ambient temperature. Mechanical and durability properties of the heated HMP mortars were evaluated and compared with those of the corresponding mortars without heating. The microscopic observation of the interfacial transition zone (ITZ) of HMP mortar was conducted through environmental scanning electron microscopy (ESEM). Results reveal that incorporation of HMP improves the workability of the HMP/cement binder while leading to decrease in compressive strength and durability. The heated HMP mortars after exposure to heating for one, two, and three days exhibit no obvious change in compressive strength while presenting notable increase in flexural strength and durability compared with the corresponding mortars without heating. The XRD, FTIR and ESEM analyses indicate that no obvious chemical reaction occurs between HMP and hydraulic cement, and thus the self-repairing for interfacial micro-crack in HMP/cement composite system is ascribed to the physical adhesion of HMP to cement matrix rather than the chemical bonding between them.

Mineralogical and microstructural studies of mortars from the bath complex of the Roman villa rustica near Mosnje (Slovenia)

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

Kramar, Sabina, E-mail: sabina.kramar@rescen.si; Zalar, Vesna; Urosevic, Maja

This study deals with the characterization of mortars collected from bath complex of the Roman villa rustica from an archeological site near Mosnje (Slovenia). The mortar layers of the mosaics, wall paintings and mortar floors were investigated. A special aggregate consisting of brick fragments was present in the mortars studied. The mineralogical and petrographic compositions of the mortars were determined by means of optical microscopy, X-ray powder diffraction and FTIR spectroscopy. Analysis of aggregate-binder interfaces using SEM-EDS revealed various types of reactivity rims. In order to assess the hydraulic characteristics of the mortars, the acid-soluble fractions were determined by ICP-OES.more » Furthermore, the results of Hg-porosimetry and gas sorption isotherms showed that mortars with a higher content of brick fragments particles exhibited a higher porosity and a greater BET surface area but a lower average pore diameter compared to mortars lacking this special aggregate. - Highlights: {yields} Mineral and microstructural characterizations of brick-lime mortars. {yields} Hydraulic character of mortars in Roman baths complex. {yields} Reaction rims were observed around brick fragments and dolomitic grains. {yields} Higher content of brick particles yielded a higher BET surface area. {yields} Addition of brick particles increased porosity and diminished pore size diameter.« less

Mechanical Properties and Microstructure of Class C Fly Ash-Based Geopolymer Paste and Mortar.

PubMed

Li, Xueying; Ma, Xinwei; Zhang, Shoujie; Zheng, Enzu

2013-04-09

This paper presents workability, compressive strength and microstructure for geopolymer pastes and mortars made of class C fly ash at mass ratios of water-to-fly ash from 0.30 to 0.35. Fluidity was in the range of 145-173 mm for pastes and 131-136 mm for mortars. The highest strengths of paste and mortar were 58 MPa and 85 MPa when they were cured at 70 °C for 24 h. In XRD patterns, unreacted quartz and some reacted product were observed. SEM examination indicated that reacted product has formed and covered the unreacted particles in the paste and mortar that were consistent with their high strength.

Acoustic Behavior of Subfloor Lightweight Mortars Containing Micronized Poly (Ethylene Vinyl Acetate) (EVA)

PubMed Central

Brancher, Luiza R.; Nunes, Maria Fernanda de O.; Grisa, Ana Maria C.; Pagnussat, Daniel T.; Zeni, Mára

2016-01-01

This paper aims to contribute to acoustical comfort in buildings by presenting a study about the polymer waste micronized poly (ethylene vinyl acetate) (EVA) to be used in mortars for impact sound insulation in subfloor systems. The evaluation method included physical, mechanical and morphological properties of the mortar developed with three distinct thicknesses designs (3, 5, and 7 cm) with replacement percentage of the natural aggregate by 10%, 25%, and 50% EVA. Microscopy analysis showed the surface deposition of cement on EVA, with preservation of polymer porosity. The compressive creep test estimated long-term deformation, where the 10% EVA sample with a 7 cm thick mortar showed the lowest percentage deformation of its height. The impact noise test was performed with 50% EVA samples, reaching an impact sound insulation of 23 dB when the uncovered slab was compared with the 7 cm thick subfloor mortar. Polymer waste addition decreased the mortar compressive strength, and EVA displayed characteristics of an influential material to intensify other features of the composite. PMID:28787851

Acoustic Behavior of Subfloor Lightweight Mortars Containing Micronized Poly (Ethylene Vinyl Acetate) (EVA).

PubMed

Brancher, Luiza R; Nunes, Maria Fernanda de O; Grisa, Ana Maria C; Pagnussat, Daniel T; Zeni, Mára

2016-01-15

This paper aims to contribute to acoustical comfort in buildings by presenting a study about the polymer waste micronized poly (ethylene vinyl acetate) (EVA) to be used in mortars for impact sound insulation in subfloor systems. The evaluation method included physical, mechanical and morphological properties of the mortar developed with three distinct thicknesses designs (3, 5, and 7 cm) with replacement percentage of the natural aggregate by 10%, 25%, and 50% EVA. Microscopy analysis showed the surface deposition of cement on EVA, with preservation of polymer porosity. The compressive creep test estimated long-term deformation, where the 10% EVA sample with a 7 cm thick mortar showed the lowest percentage deformation of its height. The impact noise test was performed with 50% EVA samples, reaching an impact sound insulation of 23 dB when the uncovered slab was compared with the 7 cm thick subfloor mortar. Polymer waste addition decreased the mortar compressive strength, and EVA displayed characteristics of an influential material to intensify other features of the composite.

Pore size distribution of OPC and SRPC mortars in presence of chlorides

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

Suryavanshi, A.K.; Scantlebury, J.D.; Lyon, S.B.

1995-07-01

The pore structure of chloride-free ordinary portland cement (OPC) and sulphate resistant portland cement (SRPC) mortars are compared with the corresponding mortars with NaCl and CaCl{sub 2} added during mixing. In both OPC and SRPC mortars the addition of chlorides reduced the total accessible pore volumes compared to the corresponding chloride-free mortars. Also, in the presence of chlorides, the number of coarse pores were increased. These changes in the pore structure are believed to be due to dense calcium silicate hydrate (C-S-H) gel morphology formed in the presence of chlorides. The SRPC showed greater changes in pore structures than themore » OPC with equivalent amounts of chlorides added. This may be due to the lower chloride binding capacity of the SRPC and hence the higher availability of free chlorides to modify the gel morphology.« less

Calcite-forming bacteria for compressive strength improvement in mortar.

PubMed

Park, Sung-Jin; Park, Yu-Mi; Chun, Woo-Young; Kim, Wha-Jung; Ghim, Sa-Youl

2010-04-01

Microbiological calcium carbonate precipitation (MCP) has been investigated for its ability to improve the compressive strength of concrete mortar. However, very few studies have been conducted on the use of calcite-forming bacteria (CFB) to improve compressive strength. In this study, we discovered new bacterial genera that are capable of improving the compressive strength of concrete mortar. We isolated 4 CFB from 7 environmental concrete structures. Using sequence analysis of the 16S rRNA genes, the CFB could be partially identified as Sporosarcina soli KNUC401, Bacillus massiliensis KNUC402, Arthrobacter crystallopoietes KNUC403, and Lysinibacillus fusiformis KNUC404. Crystal aggregates were apparent in the bacterial colonies grown on an agar medium. Stereomicroscopy, scanning electron microscopy, and x-ray diffraction analyses illustrated both the crystal growth and the crystalline structure of the CaCO3 crystals. We used the isolates to improve the compressive strength of concrete mortar cubes and found that KNUC403 offered the best improvement in compressive strength.

LabPatch, an acquisition and analysis program for patch-clamp electrophysiology.

PubMed

Robinson, T; Thomsen, L; Huizinga, J D

2000-05-01

An acquisition and analysis program, "LabPatch," has been developed for use in patch-clamp research. LabPatch controls any patch-clamp amplifier, acquires and records data, runs voltage protocols, plots and analyzes data, and connects to spreadsheet and database programs. Controls within LabPatch are grouped by function on one screen, much like an oscilloscope front panel. The software is mouse driven, so that the user need only point and click. Finally, the ability to copy data to other programs running in Windows 95/98, and the ability to keep track of experiments using a database, make LabPatch extremely versatile. The system requirements include Windows 95/98, at least a 100-MHz processor and 16 MB RAM, a data acquisition card, digital-to-analog converter, and a patch-clamp amplifier. LabPatch is available free of charge at http://www.fhs.mcmaster.ca/huizinga/.

Comparing the use of sewage sludge ash and glass powder in cement mortars.

PubMed

Chen, Zhen; Poon, Chi Sun

2017-06-01

This study explored the suitability of using sewage sludge ash (SSA) and mixed-colored glass powder (MGP) as construction materials in cement mortars. Positive findings from this study may help promote the recycling of waste SSA and MGP in construction works. The results indicated that the SSA decreased while MGP improved the mortar workability. The SSA exhibited very low pozzolanic activity, but the cement mortar prepared with 20% SSA yielded strength values slightly superior to those of the glass mortars due to its water absorption ability. MGP can serve as a pozzolan and when 20% of cement was replaced by MGP, apparent compressive strength gains were found at later curing ages. The SSA could be used to mitigate ASR expansion while the MGP was superior in resisting drying shrinkage.

Compressive and bonding strength of fly ash based geopolymer mortar

NASA Astrophysics Data System (ADS)

Zailani, Warid Wazien Ahmad; Abdullah, Mohd Mustafa Al Bakri; Zainol, Mohd Remy Rozainy Mohd Arif; Razak, Rafiza Abd.; Tahir, Muhammad Faheem Mohd

2017-09-01

Geopolymer which is produced by synthesizing aluminosilicate source materials with an alkaline activator solution promotes sustainable and excellent properties of binder. The purpose of this paper is to determine the optimum binder to sand ratio of geopolymer mortars based on mechanical properties. In order to optimize the formulation of geopolymer mortar, various binder to sand ratios (0.25, 0.33, 0.5, 1.0, 2.0, 3.0, and 4.0) are prepared. The investigation on the effect of sand inclusion to the compressive and bonding strength of geopolymer mortar is approached. The experimental results show that the bonding strength performance of geopolymer is also depends on the various binder to sand ratio, where the optimum ratio 0.5 gives a highest strength of 12.73 MPa followed by 12.35 MPa, which corresponds the ratio 1.0 for geopolymer, while the compared value of OPC bonding strength is given by 9.3 MPa. The morphological structure at the interface zone is determined by Scanning Electron Microscope (SEM) and the homogenous bonding between geopolymer and substrate can be observed. Fly ash based geopolymers reveal a new category of mortar which has high potential to be used in the field of concrete repair and rehabilitation.

Mechanical Properties and Microstructure of Class C Fly Ash-Based Geopolymer Paste and Mortar

PubMed Central

Li, Xueying; Ma, Xinwei; Zhang, Shoujie; Zheng, Enzu

2013-01-01

This paper presents workability, compressive strength and microstructure for geopolymer pastes and mortars made of class C fly ash at mass ratios of water-to-fly ash from 0.30 to 0.35. Fluidity was in the range of 145–173 mm for pastes and 131–136 mm for mortars. The highest strengths of paste and mortar were 58 MPa and 85 MPa when they were cured at 70 °C for 24 h. In XRD patterns, unreacted quartz and some reacted product were observed. SEM examination indicated that reacted product has formed and covered the unreacted particles in the paste and mortar that were consistent with their high strength. PMID:28809222

Application of micromechanics to the characterization of mortar by ultrasound.

PubMed

Hernández, M G; Anaya, J J; Izquierdo, M A G; Ullate, L G

2002-05-01

Mechanical properties of concrete and mortar structures can be estimated by ultrasonic non-destructive testing. When the ultrasonic velocity is known, there are standardized methods based on considering the concrete a homogeneous material. Cement composites, however, are heterogeneous and porous, and have a negative effect on the mechanical properties of structures. This work studies the impact of porosity on mechanical properties by considering concrete a multiphase material. A micromechanical model is applied in which the material is considered to consist of two phases: a solid matrix and pores. From this method, a set of expressions is obtained that relates the acoustic velocity and Young's modulus of mortar. Experimental work is based on non-destructive and destructive procedures over mortar samples whose porosity is varied. A comparison is drawn between micromechanical and standard methods, showing positive results for the method here proposed.

Applying a biodeposition layer to increase the bond of a repair mortar on a mortar substrate.

PubMed

Snoeck, D; Wang, J; Bentz, D P; De Belie, N

2018-02-01

One of the major concerns in infrastructure repair is a sufficient bond between the substrate and the repair material, especially for the long-term performance and durability of the repaired structure. In this study, the bond of the repair material on the mortar substrate is promoted via the biodeposition of a calcium carbonate layer by a ureolytic bacterium. X-ray diffraction and scanning electron microscopy were used to examine the interfaces between the repair material and the substrate, as well as the polymorph of the deposited calcium carbonate. The approximately 50 μm thick biodeposition film on the mortar surface mostly consisted of calcite and vaterite. Both the repair material and the substrate tended to show a good adherence to that layer. The bond, as assessed by slant shear specimen testing, was improved by the presence of the biodeposition layer. A further increase was found when engineering the substrate surface using a structured pattern layer of biodeposition.

Effect of copolymer latexes on physicomechanical properties of mortar containing high volume fly ash as a replacement material of cement.

PubMed

Negim, El-Sayed; Kozhamzharova, Latipa; Gulzhakhan, Yeligbayeva; Khatib, Jamal; Bekbayeva, Lyazzat; Williams, Craig

2014-01-01

This paper investigates the physicomechanical properties of mortar containing high volume of fly ash (FA) as partial replacement of cement in presence of copolymer latexes. Portland cement (PC) was partially replaced with 0, 10, 20, 30 50, and 60% FA. Copolymer latexes were used based on 2-hydroxyethyl acrylate (2-HEA) and 2-hydroxymethylacrylate (2-HEMA). Testing included workability, setting time, absorption, chemically combined water content, compressive strength, and scanning electron microscopy (SEM). The addition of FA to mortar as replacement of PC affected the physicomechanical properties of mortar. As the content of FA in the concrete increased, the setting times (initial and final) were elongated. The results obtained at 28 days of curing indicate that the maximum properties of mortar occur at around 30% FA. Beyond 30% FA the properties of mortar reduce and at 60% FA the properties of mortar are lower than those of the reference mortar without FA. However, the addition of polymer latexes into mortar containing FA improved most of the physicomechanical properties of mortar at all curing times. Compressive strength, combined water, and workability of mortar containing FA premixed with latexes are higher than those of mortar containing FA without latexes.

Effect of Copolymer Latexes on Physicomechanical Properties of Mortar Containing High Volume Fly Ash as a Replacement Material of Cement

PubMed Central

Kozhamzharova, Latipa; Gulzhakhan, Yeligbayeva; Bekbayeva, Lyazzat; Williams, Craig

2014-01-01

This paper investigates the physicomechanical properties of mortar containing high volume of fly ash (FA) as partial replacement of cement in presence of copolymer latexes. Portland cement (PC) was partially replaced with 0, 10, 20, 30 50, and 60% FA. Copolymer latexes were used based on 2-hydroxyethyl acrylate (2-HEA) and 2-hydroxymethylacrylate (2-HEMA). Testing included workability, setting time, absorption, chemically combined water content, compressive strength, and scanning electron microscopy (SEM). The addition of FA to mortar as replacement of PC affected the physicomechanical properties of mortar. As the content of FA in the concrete increased, the setting times (initial and final) were elongated. The results obtained at 28 days of curing indicate that the maximum properties of mortar occur at around 30% FA. Beyond 30% FA the properties of mortar reduce and at 60% FA the properties of mortar are lower than those of the reference mortar without FA. However, the addition of polymer latexes into mortar containing FA improved most of the physicomechanical properties of mortar at all curing times. Compressive strength, combined water, and workability of mortar containing FA premixed with latexes are higher than those of mortar containing FA without latexes. PMID:25254256

Biomineralization in metakaolin modified cement mortar to improve its strength with lowered cement content.

PubMed

Li, Mengmeng; Zhu, Xuejiao; Mukherjee, Abhijit; Huang, Minsheng; Achal, Varenyam

2017-05-05

The role of industrial byproduct as supplementary cementitious material to partially replace cement has greatly contributed to sustainable environment. Metakaolin (MK), one of such byproduct, is widely used to partial replacement of cement; however, during cement replacement at high percentage, it may not be a good choice to improve the strength of concrete. Thus, in the present study, biocement, a product of microbially induced carbonate precipitation is utilized in MK-modified cement mortars to improve its compressive strength. Despite of cement replacement with MK as high as 50%, the presented technology improved compressive strength of mortars by 27%, which was still comparable to those mortars with 100% cement. The results proved that biomineralization could be effectively used in reducing cement content without compromising compressive strength of mortars. Biocementation also reduced the porosity of mortars at all ages. The process was characterized by SEM-EDS to observe bacterially-induced carbonate crystals and FTIR spectroscopy to predict responsible bonding in the formation of calcium carbonate. Further, XRD analysis identified bio/minerals formed in the MK-modified mortars. The study also encourages combining biological role in construction engineering to solve hazardous nature of cement and at same time solve the disposal problem of industrial waste for sustainable environment. Copyright © 2017 Elsevier B.V. All rights reserved.

[Study on the traditional lime mortar from the memorial archway in the southern Anhui province].

PubMed

Wei, Guo-Feng; Sun, Sheng; Wang, Cheng-Xing; Zhang, Bing-Jian; Chen, Xi-Min

2013-07-01

The traditional lime mortar was investigated by means of scanning electron microscope (SEM), X-ray diffractometry and Fourier transform infrared spectrometry (FTIR). The results show that the mortar from the memorial archway in the southern Anhui province was the organic-inorganic composite materials composed of lime with tung oil or sticky rice. It was found that the excellent performance of the tung oil-lime mortar can be explained by the compact lamellar organic-inorganic composite structure that was produced by carbonization reaction of lime, cross-linking reactions of tung oil and oxygen and complexing reaction of Ca2+ and -COO-. The compact micro-structure of sticky rice-lime mortar, which was produced due to carbonation process of lime controlled by amylopectin, should be the cause of the good performance of this kind of organic-inorganic mortar.

Compressive and flexural strength of expanded perlite aggregate mortar subjected to high temperatures

NASA Astrophysics Data System (ADS)

Zulkifeli, Muhamad Faqrul Hisham bin Mohd; Saman@Hj Mohamed, Hamidah binti Mohd

2017-08-01

Work on thermal resistant of outer structures of buildings is one of the solution to reduce death, damages and properties loss in fire cases. Structures protected with thermal resistant materials can delay or avoid failure and collapse during fire. Hence, establishment of skin cladding with advance materials to protect the structure of buildings is a necessary action. Expanded perlite is a good insulation material which can be used as aggregate replacement in mortar. This study is to study on mortar mechanical properties of flexural and compressive strength subjected to elevated temperatures using expanded perlite aggregate (EPA). This study involved experimental work which was developing mortar with sand replacement by volume of 0%, 10%, 20%, 30% and 40% of EPA and cured for 56 days. The mortars then exposed to 200°C, 400 °C, 700 °C and 1000 °C. Flexural and compressive strength of the mortar were tested. The tests showed that there were increased of flexural and compressive strength at 200°C, and constantly decreased when subjected to 400°C, 700°C and 1000 °C. There were also variation of strengths at different percentages of EPA replacement. Highest compressive strength and flexural strength recorded were both at 200 °C with 65.52 MPa and 21.34 MPa respectively. The study conclude that by using EPA as aggregate replacement was ineffective below elevated temperatures but increased the performance of the mortar at elevated temperatures.

Mortar and artillery variants classification by exploiting characteristics of the acoustic signature

NASA Astrophysics Data System (ADS)

Hohil, Myron E.; Grasing, David; Desai, Sachi; Morcos, Amir

2007-10-01

Feature extraction methods based on the discrete wavelet transform and multiresolution analysis facilitate the development of a robust classification algorithm that reliably discriminates mortar and artillery variants via acoustic signals produced during the launch/impact events. Utilizing acoustic sensors to exploit the sound waveform generated from the blast for the identification of mortar and artillery variants. Distinct characteristics arise within the different mortar variants because varying HE mortar payloads and related charges emphasize concussive and shrapnel effects upon impact employing varying magnitude explosions. The different mortar variants are characterized by variations in the resulting waveform of the event. The waveform holds various harmonic properties distinct to a given mortar/artillery variant that through advanced signal processing techniques can employed to classify a given set. The DWT and other readily available signal processing techniques will be used to extract the predominant components of these characteristics from the acoustic signatures at ranges exceeding 2km. Exploiting these techniques will help develop a feature set highly independent of range, providing discrimination based on acoustic elements of the blast wave. Highly reliable discrimination will be achieved with a feed-forward neural network classifier trained on a feature space derived from the distribution of wavelet coefficients, frequency spectrum, and higher frequency details found within different levels of the multiresolution decomposition. The process that will be described herein extends current technologies, which emphasis multi modal sensor fusion suites to provide such situational awareness. A two fold problem of energy consumption and line of sight arise with the multi modal sensor suites. The process described within will exploit the acoustic properties of the event to provide variant classification as added situational awareness to the solider.

Study on basalt fiber parameters affecting fiber-reinforced mortar

NASA Astrophysics Data System (ADS)

Orlov, A. A.; Chernykh, T. N.; Sashina, A. V.; Bogusevich, D. V.

2015-01-01

This article considers the effect of different dosages and diameters of basalt fibers on tensile strength increase during bending of fiberboard-reinforced mortar samples. The optimal dosages of fiber, providing maximum strength in bending are revealed. The durability of basalt fiber in an environment of cement, by means of microscopic analysis of samples of fibers and fiberboard-reinforced mortar long-term tests is examined. The article also compares the behavior of basalt fiber in the cement stone environment to a glass one and reveals that the basalt fiber is not subject to destruction.

Effect of water curing duration on strength behaviour of portland composite cement (PCC) mortar

NASA Astrophysics Data System (ADS)

Caronge, M. A.; Tjaronge, M. W.; Hamada, H.; Irmawaty, R.

2017-11-01

Cement manufacturing of Indonesia has been introduced Portland Composite Cement (PCC) to minimize the rising production cost of cement which contains 80% clinker and 20% mineral admixture. A proper curing is very important when the cement contains mineral admixture materials. This paper reports the results of an experimental study conducted to evaluate the effect of water curing duration on strength behaviour of PCC mortar. Mortar specimens with water to cement ratio of (W/C) 0.5 were casted. Compressive strength, flexural strength and concrete resistance were tested at 7, 28 and 91 days cured water. The results indicated that water curing duration is essential to continue the pozzolanic reaction in mortar which contributes to the development of strength of mortar made with PCC.

Application of natural seaweed modified mortar for sustainable concrete production

NASA Astrophysics Data System (ADS)

Siddique, M. N. I.; Zularisam, A. W.

2018-04-01

The effect of seaweed such as Eucheuma Cottonii (gel) and Gracilaria Sp. modified mortar on the properties of sustainable concrete was investigated. Pre-experiment and main-experiment was conducted to carry out this study. Pre-experiment was conducted to study the compressive strength of the sustainable concrete. The main-experiment studied the compressive and splitting strength. Results showed that seaweed modified mortar yielded satisfactory compressive and splitting strength of 30 MPa and 5 MPa at 28 days.

Scopolamine Transdermal Patch

MedlinePlus

... the adhesive surface of the patch, the clear plastic protective strip should be peeled off and discarded. ... needed, remove the patch and dispose of it. Wrap the patch in tissue or paper to avoid ...

Diclofenac Transdermal Patch

MedlinePlus

... will be applying the patch. Cut open the envelope containing the patches, cutting on the dotted line ... it. Pull apart the zipper seal on the envelope and remove one patch. Reseal the envelope by ...

Modeling and numerical simulation of interior ballistic processes in a 120mm mortar system

NASA Astrophysics Data System (ADS)

Acharya, Ragini

Numerical Simulation of interior ballistic processes in gun and mortar systems is a very difficult and interesting problem. The mathematical model for the physical processes in the mortar systems consists of a system of non-linear coupled partial differential equations, which also contain non-homogeneity in form of the source terms. This work includes the development of a three-dimensional mortar interior ballistic (3D-MIB) code for a 120mm mortar system and its stage-wise validation with multiple sets of experimental data. The 120mm mortar system consists of a flash tube contained within an ignition cartridge, tail-boom, fin region, charge increments containing granular propellants, and a projectile payload. The ignition cartridge discharges hot gas-phase products and unburned granular propellants into the mortar tube through vent-holes on its surface. In view of the complexity of interior ballistic processes in the mortar propulsion system, the overall problem was solved in a modular fashion, i.e., simulating each physical component of the mortar propulsion system separately. These modules were coupled together with appropriate initial and boundary conditions. The ignition cartridge and mortar tube contain nitrocellulose-based ball propellants. Therefore, the gas dynamical processes in the 120mm mortar system are two-phase, which were simulated by considering both phases as an interpenetrating continuum. Mass and energy fluxes from the flash tube into the granular bed of ignition cartridge were determined from a semi-empirical technique. For the tail-boom section, a transient one-dimensional two-phase compressible flow solver based on method of characteristics was developed. The mathematical model for the interior ballistic processes in the mortar tube posed an initial value problem with discontinuous initial conditions with the characteristics of the Riemann problem due to the discontinuity of the initial conditions. Therefore, the mortar tube model was solved

Studies on the reuse of waste printed circuit board as an additive for cement mortar.

PubMed

Ban, Bong-Chan; Song, Jong-Yoon; Lim, Joong-Yeon; Wang, Soo-Kyoon; An, Kwang-Guk; Kim, Dong-Su

2005-01-01

The recent development in electronic industries has generated a drastic increase in production of printed circuit boards (PCB). Accordingly, the amount of waste PCB from electronic productions and waste electronics and its environmental impact such as soil and groundwater contamination have become a great concern. This study aims to propose a method for reuse of waste PCB as an additive for cement mortar. Although the expansibility of waste PCB powder finer than 0.08 mm in water was observed to be greater than 2.0%, the maximum expansion rates in water for 0.08 to approximately 0.15 and 0.15 to approximately 0.30 mm sized PCB powders were less than 2.0%, which satisfied the necessary condition as an alternative additive for cement mortar in place of sand. The difference in the compressive strength of standard mortar and waste PCB added mortar was observed to be less than 10% and their difference was expected to be smaller after prolonged aging. The durability of waste PCB added cement mortar was also examined through dry/wet conditioning cyclic tests and acidic/alkaline conditioning tests. From the tests, both weight and compressive strength of cement mortar were observed to be recovered with aging. The leaching test for heavy metals from waste PCB added mortar showed that no heavy metal ions such as copper, lead, or cadmium were detected in the leachate, which resulted from fixation effect of the cement hydrates.

A Study on the Properties of Carbon Black Mortar Using Granulated Blast Furnace Slag and Polymer.

PubMed

Jang, Hong-Seok; Jeon, Ui-Hyeon; So, Seung-Young

2015-11-01

White Portland Cement (WPC) and inorganic pigment have been used in colored concrete, but there are some physical problems such as increases in efflorescence, and poor workability and low economics. The aim of this study was to investigate the effects of GBFS and polymer (methyl cellulose) on the physical properties of carbon black mortar. For this purpose, a flow test, compressive strength test and color evaluation and was carried out on cement mortar mixed with polymer by changing the proportion of cement and ratio of GBFS. The results show that the addition of polymer influences significantly the color value efficiency in colored mortar. This is due to the reduction of overall amount of micro pore. This polymer films prevent the transport of soluble calcium towards the surface, and decreases efflorescence. And the flow of colored mortar was increased in proportion to the addition rate of the GBFS. In addition the strength of colored mortars with GBFS at the long-term aged (after 28 days) was higher than that of the general WPC mortar, although its strength was developed slowly at the early ages.

Influence of Titanium Dioxide Nanoparticles on the Sulfate Attack upon Ordinary Portland Cement and Slag-Blended Mortars

PubMed Central

Atta-ur-Rehman; Qudoos, Abdul; Kim, Hong Gi

2018-01-01

In this study, the effects of titanium dioxide (TiO2) nanoparticles on the sulfate attack resistance of ordinary Portland cement (OPC) and slag-blended mortars were investigated. OPC and slag-blended mortars (OPC:Slag = 50:50) were made with water to binder ratio of 0.4 and a binder to sand ratio of 1:3. TiO2 was added as an admixture as 0%, 3%, 6%, 9% and 12% of the binder weight. Mortar specimens were exposed to an accelerated sulfate attack environment. Expansion, changes in mass and surface microhardness were measured. Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), X-ray Diffraction (XRD), Thermogravimetry Analysis (TGA) and Differential Scanning Calorimetry (DSC) tests were conducted. The formation of ettringite and gypsum crystals after the sulfate attack were detected. Both these products had caused crystallization pressure in the microstructure of mortars and deteriorated the mortars. Our results show that the addition of nano-TiO2 accelerated expansion, variation in mass, loss of surface microhardness and widened cracks in OPC and slag-blended mortars. Nano-TiO2 containing slag-blended mortars were more resistant to sulfate attack than nano-TiO2 containing OPC mortars. Because nano-TiO2 reduced the size of coarse pores, so it increased crystallization pressure due to the formation of ettringite and gypsum thus led to more damage under sulfate attack. PMID:29495616

Coevolution of patch-type dependent emigration and patch-type dependent immigration.

PubMed

Weigang, Helene C

2017-08-07

The three phases of dispersal - emigration, transfer and immigration - are affecting each other and the former and latter decisions may depend on patch types. Despite the inevitable fact of the complexity of the dispersal process, patch-type dependencies of dispersal decisions modelled as emigration and immigration are usually missing in theoretical dispersal models. Here, I investigate the coevolution of patch-type dependent emigration and patch-type dependent immigration in an extended Hamilton-May model. The dispersing population inhabits a landscape structured into many patches of two types and disperses during a continuous-time season. The trait under consideration is a four dimensional vector consisting of two values for emigration probability from the patches and two values for immigration probability into the patches of each type. Using the adaptive dynamics approach I show that four qualitatively different dispersal strategies may evolve in different parameter regions, including a counterintuitive strategy, where patches of one type are fully dispersed from (emigration probability is one) but individuals nevertheless always immigrate into them during the dispersal season (immigration probability is one). I present examples of evolutionary branching in a wide parameter range, when the patches with high local death rate during the dispersal season guarantee a high expected disperser output. I find that two dispersal strategies can coexist after evolutionary branching: a strategy with full immigration only into the patches with high expected disperser output coexists with a strategy that immigrates into any patch. Stochastic simulations agree with the numerical predictions. Since evolutionary branching is also found when immigration evolves alone, the present study is adding coevolutionary constraints on the emigration traits and hence finds that the coevolution of a higher dimensional trait sometimes hinders evolutionary diversification. Copyright © 2017

Microscopic characterisation of old mortars from the Santa Maria Church in Evora

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

Adriano, P., E-mail: padriano@lnec.pt; Santos Silva, A., E-mail: ssilva@lnec.pt; Veiga, R., E-mail: rveiga@lnec.pt

2009-07-15

Evora Cathedral (one of the most emblematic monuments of Evora - Portugal) has suffered several conservation and restoration interventions through the ages, without, however, any type of previous knowledge about mortars and materials used. This work was carried out in order to identify the mortar's composition in different locations, which were attributed to different construction or conservation periods. The characterisation methodology involved a multidisciplinary set of chemical, physical, microstructural and mechanical techniques, and gave special attention to the use of microstructural characterisation techniques, particularly petrographical analysis and scanning electron microscopy for the identification of the mortar's constituents as well asmore » in the evaluation of the state of conservation. The test results showed that two types of aerial binders were used, dolomitic and calcitic limes, the former being predominant. The aggregates used have a siliceous nature and are similar in composition to the granodiorites of the region around Evora. The mortars differ in the aggregate contents and, in some cases, crushed bricks were used as an additive.« less

Nonconforming mortar element methods: Application to spectral discretizations

NASA Technical Reports Server (NTRS)

Maday, Yvon; Mavriplis, Cathy; Patera, Anthony

1988-01-01

Spectral element methods are p-type weighted residual techniques for partial differential equations that combine the generality of finite element methods with the accuracy of spectral methods. Presented here is a new nonconforming discretization which greatly improves the flexibility of the spectral element approach as regards automatic mesh generation and non-propagating local mesh refinement. The method is based on the introduction of an auxiliary mortar trace space, and constitutes a new approach to discretization-driven domain decomposition characterized by a clean decoupling of the local, structure-preserving residual evaluations and the transmission of boundary and continuity conditions. The flexibility of the mortar method is illustrated by several nonconforming adaptive Navier-Stokes calculations in complex geometry.

Pretreatment of pericardial patches with antibiotics does not alter patch healing in vivo.

PubMed

Bai, Hualong; Kuwahara, Go; Wang, Mo; Brownson, Kirstyn E; Foster, Trenton R; Yamamoto, Kota; Xing, Ying; Dardik, Alan

2016-04-01

Pretreatment with antibiotics is commonly performed before surgical implantation of prosthetic materials. We previously showed that pericardial patches are infiltrated by macrophages and arterial stem cells after implantation into an artery. We hypothesized that antibiotic pretreatment would diminish the number of cells infiltrating into the patch, potentially affecting early neointimal formation. Bovine pericardial patches were pretreated with saline, bacitracin (500 U/mL), or cephalexin (10 mg/mL) for 30 minutes before implantation into the Wistar rat infrarenal aorta. Patches were retrieved on day 7 or day 30 and analyzed for histology and cell infiltration. Markers of proliferation, apoptosis, vascular cell identity, and M1 and M2 macrophage subtypes were examined using immunofluorescence and immunohistochemistry. Extracted proteins were analyzed by Western blot. At day 7, pericardial patches pretreated with bacitracin or cephalexin showed similar amounts of neointimal thickening (P = .55) and cellular infiltration (P = .42) compared with control patches. Patches pretreated with antibiotics showed similar proliferation (P = .09) and apoptosis (P = .84) as control patches. The cell composition of the neointima in pretreated patches was similar to control patches, with a thin endothelial layer overlying a thin layer of smooth muscle cells (P = .45), and containing similar numbers of CD34-positive (P = .26) and vascular endothelial growth factor receptor 2-positive (P = .31) cells. Interestingly, within the body of the patch, there were fewer macrophages (P = .0003) and a trend towards fewer endothelial progenitor cells (P = .051). No M1 macrophages were found in or around any of the patches. M2 macrophages were present around the patches, and there was no difference in numbers of M2 macrophages surrounding control patches and patches pretreated with antibiotics (P = .24). There was no difference in neointimal thickness at day 30 between control

Preparation and Characterization of New Geopolymer-Epoxy Resin Hybrid Mortars

PubMed Central

Colangelo, Francesco; Roviello, Giuseppina; Ricciotti, Laura; Ferone, Claudio; Cioffi, Raffaele

2013-01-01

The preparation and characterization of metakaolin-based geopolymer mortars containing an organic epoxy resin are presented here for the first time. The specimens have been prepared by means of an innovative in situ co-reticulation process, in mild conditions, of commercial epoxy based organic resins and geopolymeric slurry. In this way, geopolymer based hybrid mortars characterized by a different content of normalized sand (up to 66% in weight) and by a homogeneous dispersion of the organic resin have been obtained. Once hardened, these new materials show improved compressive strength and toughness in respect to both the neat geopolymer and the hybrid pastes since the organic polymer provides a more cohesive microstructure, with a reduced amount of microcracks. The microstructural characterization allows to point out the presence of an Interfacial Transition Zone similar to that observed in cement based mortars and concretes. A correlation between microstructural features and mechanical properties has been studied too. PMID:28811418

Granisetron Transdermal Patch

MedlinePlus

... patch. Each patch is stuck onto a thin plastic liner and a separate rigid plastic film. Do not open the pouch in advance, ... cut the patch into pieces. Peel the thin plastic liner off of the printed side of the ...

Lidocaine Transdermal Patch

MedlinePlus

... It works by stopping nerves from sending pain signals. ... time and the length of time you may wear the patches. Never apply more than three patches at one time, and never wear patches for more than 12 hours per day. ...

A hydrogel pericardial patch.

PubMed

Allder, M A; Guilbeau, E J; Brandon, T A; Walker, A S; Koeneman, J B; Fisk, R L

1990-01-01

Patients undergoing repeat cardiac operations are higher operative risks than those undergoing an initial cardiac procedure because adhesion formation can occur if the native pericardium is not closed. A unique composite patch that may be used to augment the pericardial tissue when primary closure is not possible has been developed. The patch is made of a hydrogel, poly (2-hydroxyethyl methacrylate), reinforced with an ethylene tetrafluoroethylene (ETFE) mesh. The mesh provides the needed mechanical properties, whereas the patch's surface properties are comparable to the hydrogel. Two types of patches were fabricated: one with the mesh weave at a perpendicular orientation and one at 45 degrees to the principle loading direction. The patches were mechanically tested and compared with canine pericardium. Ultimate tensile strength of the patches is not significantly different from canine pericardium (p less than 0.05), are the patch suture strength is nearly twice that of canine pericardium. The perpendicular patch is stiffer than canine pericardium, whereas the 45 degree patch is not (p less than 0.05). The 45 degree patch shows considerable promise as a pericardial substitute because it closely matches the properties native canine pericardium.

Verification of chloride adsorption effect of mortar with salt adsorbent

NASA Astrophysics Data System (ADS)

Hoshina, T.; Nakajima, N.; Sudo, H.; Date, S.

2017-11-01

In order to investigate the chloride adsorption effect of mortar mixed with chloride adsorbent, electrophoresis test using mortar specimen and immersion dry repeated test were conducted to evaluate chloride adsorption effect. As a result, it was confirmed that soluble salt content that causes corrosion of rebar in the specimen was reduced by the chloride adsorbent and corrosion inhibiting effect of the rebar was also obtained. It was also confirmed that by increasing dosage of the chloride adsorbent, the chloride adsorbing effect becomes larger as well..

Assessing the effects of UVA photocatalysis on soot-coated TiO2-containing mortars.

PubMed

De la Rosa, José M; Miller, Ana Z; Pozo-Antonio, J Santiago; González-Pérez, José A; Jiménez-Morillo, Nicasio T; Dionisio, Amelia

2017-12-15

The deposition of soot on building surfaces darkens their colour and leads to undesirable black crusts, which are one of the most serious problems on the conservation of built cultural heritage. As a preventive strategy, self-cleaning systems based on the use of titanium dioxide (TiO 2 ) coatings have been employed on building materials for degrading organic compounds deposited on building surfaces, improving their durability and performance. In this study, the self-cleaning effect of TiO 2 -containing mortars coated with diesel soot has been appraised under laboratory conditions. The mortar samples were manufactured using lime putty and two different doses of TiO 2 (2.5% and 5%). The lime mortars were then coated with diesel engine soot and irradiated with ultraviolet A (UVA) illumination for 30days. The photocatalytic efficiency was evaluated by visual inspection, field emission scanning electron microscopy (FESEM) and colour spectrophotometry. Changes in the chemical composition of the soot particles (including persistent organic pollutants) were assessed by analytical pyrolysis (Py-GC/MS) and solid state 13 C NMR spectroscopy. The FESEM and colour spectrophotometry revealed that the soot-coated TiO 2 -containing mortars promoted a self-cleaning effect after UVA irradiation. The combination of analytical pyrolysis and 13 C solid state NMR showed that the UVA irradiation caused the cracking of polycyclic aromatic structures and n-alkyl compounds of the diesel soot and its transformation into methyl polymers. Our findings also revealed that the inclusion of TiO 2 in the lime mortar formulations catalysed these transformations promoting the self-cleaning of the soot-stained mortars. The combined action of TiO 2 and UVA irradiation is a promising proxy to clean lime mortars affected by soot deposition. Copyright © 2017 Elsevier B.V. All rights reserved.

Birth Control Patch

MedlinePlus

... Safe Videos for Educators Search English Español Birth Control Patch KidsHealth / For Teens / Birth Control Patch What's in this article? What Is It? ... It Cost? Print What Is It? The birth control patch is a thin, beige, 1¾-inch (4½- ...

Influence of viscosity modifying admixtures on the rheological behavior of cement and mortar pastes

NASA Astrophysics Data System (ADS)

Bouras, R.; Kaci, A.; Chaouche, M.

2012-03-01

The influence of Viscosity-modifying admixtures (VMA) dosage rate on the steady state rheological properties, including the yield stress, fluid consistency index and flow behaviour index, of cementitious materials is considered experimentally. The investigation is undertaken both at cement paste and mortar scales. It is found that the rheological behaviour of the material is in general dependent upon shear-rate interval considered. At sufficiently low shear-rates the materials exhibit shear-thinning. This behaviour is attributed to flow-induced defloculation of the solid particles and VMA polymer disentanglement and alignment. At relatively high shear-rates the pastes becomes shear-thickening, due to repulsive interactions among the solid particles. There is a qualitative difference between the influence of VMA dosage at cement and mortar scales: at cement scale we obtain a monotonic increase of the yield stress, while at mortar scale there exists an optimum VMA dosage for which the yield stress is a minimum. The flow behaviour index exhibit a maximum in the case of cement pastes and monotonically decreases in the case of mortars. On the other hand, the fluid consistency index presents a minimum for both cement pastes and mortars.

Field and laboratory determination of a poly(vinyl/vinylidene chloride) additive in brick mortar.

PubMed

Law, S L; Newman, J H; Ptak, F L

1990-02-01

A polymerized vinyl/vinylidene chloride additive, used in brick mortar during the 60s and 70s, is detected at the building site by the field method, which employs a commercially available chloride test strip. The field test results can then be verified by the laboratory methods. In one method, total chlorine in the mortar is determined by an oxygen-bomb method and the additive chloride is determined by difference after water-soluble chlorides have been determined on a separate sample. In the second method, the polymerized additive is extracted directly from the mortar with tetrahydrofuran (THF). The difference in weight before and after extraction of the additive gives the weight of additive in the mortar. Evaporation of the THF from the extract leaves a thin film of the polymer, which gives an infrared "fingerprint" spectrum characteristic of the additive polymer.

Numerical Simulation of the Freeze-Thaw Behavior of Mortar Containing Deicing Salt Solution

PubMed Central

Esmaeeli, Hadi S.; Farnam, Yaghoob; Bentz, Dale P.; Zavattieri, Pablo D.; Weiss, Jason

2016-01-01

This paper presents a one-dimensional finite difference model that is developed to describe the freeze-thaw behavior of an air-entrained mortar containing deicing salt solution. A phenomenological model is used to predict the temperature and the heat flow for mortar specimens during cooling and heating. Phase transformations associated with the freezing/melting of water/ice or transition of the eutectic solution from liquid to solid are included in this phenomenological model. The lever rule is used to calculate the quantity of solution that undergoes the phase transformation, thereby simulating the energy released/absorbed during phase transformation. Undercooling and pore size effects are considered in the numerical model. To investigate the effect of pore size distribution, this distribution is considered using the Gibbs-Thomson equation in a saturated mortar specimen. For an air-entrained mortar, the impact of considering pore size (and curvature) on freezing was relatively insignificant; however the impact of pore size is much more significant during melting. The fluid inside pores smaller than 5 nm (i.e., gel pores) has a relatively small contribution in the macroscopic freeze-thaw behavior of mortar specimens within the temperature range used in this study (i.e., +24 °C to −35 °C), and can therefore be neglected for the macroscopic freeze-thaw simulations. A heat sink term is utilized to simulate the heat dissipation during phase transformations. Data from experiments performed using a low-temperature longitudinal guarded comparative calorimeter (LGCC) on mortar specimens fully saturated with various concentration NaCl solutions or partially saturated with water is compared to the numerical results and a promising agreement is generally obtained. PMID:28082830

Numerical Simulation of the Freeze-Thaw Behavior of Mortar Containing Deicing Salt Solution.

PubMed

Esmaeeli, Hadi S; Farnam, Yaghoob; Bentz, Dale P; Zavattieri, Pablo D; Weiss, Jason

2017-02-01

This paper presents a one-dimensional finite difference model that is developed to describe the freeze-thaw behavior of an air-entrained mortar containing deicing salt solution. A phenomenological model is used to predict the temperature and the heat flow for mortar specimens during cooling and heating. Phase transformations associated with the freezing/melting of water/ice or transition of the eutectic solution from liquid to solid are included in this phenomenological model. The lever rule is used to calculate the quantity of solution that undergoes the phase transformation, thereby simulating the energy released/absorbed during phase transformation. Undercooling and pore size effects are considered in the numerical model. To investigate the effect of pore size distribution, this distribution is considered using the Gibbs-Thomson equation in a saturated mortar specimen. For an air-entrained mortar, the impact of considering pore size (and curvature) on freezing was relatively insignificant; however the impact of pore size is much more significant during melting. The fluid inside pores smaller than 5 nm (i.e., gel pores) has a relatively small contribution in the macroscopic freeze-thaw behavior of mortar specimens within the temperature range used in this study (i.e., +24 °C to -35 °C), and can therefore be neglected for the macroscopic freeze-thaw simulations. A heat sink term is utilized to simulate the heat dissipation during phase transformations. Data from experiments performed using a low-temperature longitudinal guarded comparative calorimeter (LGCC) on mortar specimens fully saturated with various concentration NaCl solutions or partially saturated with water is compared to the numerical results and a promising agreement is generally obtained.

Changes in water absorptivity of slag based cement mortars exposed to sulphur-oxidising A. thiooxidans bacteria

NASA Astrophysics Data System (ADS)

Estokova, A.; Smolakova, M.; Luptakova, A.; Strigac, J.

2017-10-01

Water absorptivity is heavily influenced by the volume and connectivity of pores in the pore network of cement composites and has been used as an important parameter for quantifying their durability. To improve the durability and permeability of mortars, various mineral admixtures such as furnace slag, silica fume or fly ash are added into the mortar and concrete mixtures. These admixtures provide numerous important advantages such as corrosion control, improvement of mechanical and physical properties and better workability. This study investigated the changes in absorptivity of cement mortars with different amounts of mineral admixture, represented by granulated blast furnace slag, under aggressive bacterial influence. The water absorptivity of mortars specimens exposed to sulphur-oxidising bacteria A. thiooxidans for the period of 3 and 6 months has changed due to bio-corrosion-based degradation process. The differences in water absorptivity in dependence on the mortars composition have been observed.

Strengthening and repair of RC beams with sugarcane bagasse fiber reinforced cement mortar

NASA Astrophysics Data System (ADS)

Syamir Senin, Mohamad; Shahidan, Shahiron; Maarof, M. Z. Md; Syazani Leman, Alif; Zuki, S. S. Mohd; Azmi, M. A. Mohammad

2017-11-01

The use of a jacket made of fiber reinforced cement mortar with tensile hardening behaviour for strengthening RC beams was investigated in this study. A full-scale test was conducted on beams measuring 1000mm in length. A 25mm jacket was directly applied to the surface of the beams to test its ability to repair and strengthen the beams. The beams were initially damaged and eventually repaired. Three types of beams which included unrepaired beams, beams repaired with normal mortar jacket and beams repaired with 10% sugarcane bagasse fiber mortar jacket were studied. The jacket containing 10% of sugarcane bagasse fiber enhanced the flexural strength of the beams.

Neutron attenuation characteristics of polyethylene, polyvinyl chloride, and heavy aggregate concrete and mortars.

PubMed

Abdul-Majid, S; Othman, F

1994-03-01

Polyethylene and polyvinyl chloride pellets were introduced into concrete to improve its neutron attenuation characteristics while several types of heavy coarse aggregates were used to improve its gamma ray attenuation properties. Neutron and gamma ray attenuation were studied in concrete samples containing coarse aggregates of barite, pyrite, basalt, hematite, and marble as well as polyethylene and polyvinyl chloride pellets in narrow-beam geometry. The highest neutron attenuation was shown by polyethylene mortar, followed by polyvinyl chloride mortar; barite and pyrite concrete showed higher gamma ray attenuation than ordinary concrete. Broad-beam and continuous (infinite) medium geometries were used to study the neutron attenuation of samples containing polymers at different concentrations with and without heavy aggregates, the fitting equations were established, and from these the neutron removal coefficients were deduced. In a radiation field of neutrons and gamma rays, the appropriate concentration of polymer and heavy aggregate can be selected to give the optimum total dose attenuation depending on the relative intensities of each type of radiation. This would give much better design flexibility over ordinary concrete. The compressive strength tests performed on mortar and concrete samples showed that their value, in general, decreases as polymer concentration increases and that the polyvinyl chloride mortar showed higher values than the polyethylene mortar. For general construction purposes, the compression strength was considered acceptable in these samples.

Alkali activated slag mortars provide high resistance to chloride-induced corrosion of steel

NASA Astrophysics Data System (ADS)

Criado, Maria; Provis, John L.

2018-06-01

The pore solutions of alkali-activated slag cements and Portland-based cements are very different in terms of their chemical and redox characteristics, particularly due to the high alkalinity and high sulfide content of alkali-activated slag cement. Therefore, differences in corrosion mechanisms of steel elements embedded in these cements could be expected, with important implications for the durability of reinforced concrete elements. This study assesses the corrosion behaviour of steel embedded in alkali-activated blast furnace slag (BFS) mortars exposed to alkaline solution, alkaline chloride-rich solution, water, and standard laboratory conditions, using electrochemical techniques. White Portland cement (WPC) mortars and blended cement mortars (white Portland cement and blast furnace slag) were also tested for comparative purposes. The steel elements embedded in immersed alkali-activated slag mortars presented very negative redox potentials and high apparent corrosion current values; the presence of sulfide reduced the redox potential, and the oxidation of the reduced sulfur-containing species within the cement itself gave an electrochemical signal that classical electrochemical tests for reinforced concrete durability would interpret as being due to steel corrosion processes. However, the actual observed resistance to chloride-induced corrosion was very high, as measured by extraction and characterisation of the steel at the end of a 9-month exposure period, whereas the steel embedded in white Portland cement mortars was significantly damaged under the same conditions.

Study on compressive strength of self compacting mortar cubes under normal & electric oven curing methods

NASA Astrophysics Data System (ADS)

Prasanna Venkatesh, G. J.; Vivek, S. S.; Dhinakaran, G.

2017-07-01

In the majority of civil engineering applications, the basic building blocks were the masonry units. Those masonry units were developed as a monolithic structure by plastering process with the help of binding agents namely mud, lime, cement and their combinations. In recent advancements, the mortar study plays an important role in crack repairs, structural rehabilitation, retrofitting, pointing and plastering operations. The rheology of mortar includes flowable, passing and filling properties which were analogous with the behaviour of self compacting concrete. In self compacting (SC) mortar cubes, the cement was replaced by mineral admixtures namely silica fume (SF) from 5% to 20% (with an increment of 5%), metakaolin (MK) from 10% to 30% (with an increment of 10%) and ground granulated blast furnace slag (GGBS) from 25% to 75% (with an increment of 25%). The ratio between cement and fine aggregate was kept constant as 1: 2 for all normal and self compacting mortar mixes. The accelerated curing namely electric oven curing with the differential temperature of 128°C for the period of 4 hours was adopted. It was found that the compressive strength obtained from the normal and electric oven method of curing was higher for self compacting mortar cubes than normal mortar cube. The cement replacement by 15% SF, 20% MK and 25%GGBS obtained higher strength under both curing conditions.

Effects of Blended-Cement Paste Chemical Composition Changes on Some Strength Gains of Blended-Mortars

PubMed Central

Kirgiz, Mehmet Serkan

2014-01-01

Effects of chemical compositions changes of blended-cement pastes (BCPCCC) on some strength gains of blended cement mortars (BCMSG) were monitored in order to gain a better understanding for developments of hydration and strength of blended cements. Blended cements (BC) were prepared by blending of 5% gypsum and 6%, 20%, 21%, and 35% marble powder (MP) or 6%, 20%, 21%, and 35% brick powder (BP) for CEMI42.5N cement clinker and grinding these portions in ball mill at 30 (min). Pastes and mortars, containing the MP-BC and the BP-BC and the reference cement (RC) and tap water and standard mortar sand, were also mixed and they were cured within water until testing. Experiments included chemical compositions of pastes and compressive strengths (CS) and flexural strengths (FS) of mortars were determined at 7th-day, 28th-day, and 90th-day according to TS EN 196-2 and TS EN 196-1 present standards. Experimental results indicated that ups and downs of silica oxide (SiO2), sodium oxide (Na2O), and alkali at MP-BCPCC and continuously rising movement of silica oxide (SiO2) at BP-BCPCC positively influenced CS and FS of blended cement mortars (BCM) in comparison with reference mortars (RM) at whole cure days as MP up to 6% or BP up to 35% was blended for cement. PMID:24587737

The Effect of Mechanical Performance on PP Fiber to Polymer Mortar

NASA Astrophysics Data System (ADS)

Xie, Xinying; Kang, Xinnan; Jin, Yujie; Cai, Jingwei

2018-03-01

It introduces the purpose of of adding Polypropylene fiber. The paper The production process and test method of epoxy resin mortar with PP fiber are developed. The influence of PP fiber on mechanical properties of polymer mortar was studied in this paper, including the influence of PP fiber content on flexural strength, the ratio of flexural and compressive strength and so on. The experimental results are compared and analyzed. The reason is found, the conclusion of research is acquired.

Sulfate and acid resistant concrete and mortar

DOEpatents

Liskowitz, John W.; Wecharatana, Methi; Jaturapitakkul, Chai; Cerkanowicz, deceased, Anthony E.

1998-01-01

The present invention relates to concrete, mortar and other hardenable mixtures comprising cement and fly ash for use in construction and other applications, which hardenable mixtures demonstrate significant levels of acid and sulfate resistance while maintaining acceptable compressive strength properties. The acid and sulfate hardenable mixtures of the invention containing fly ash comprise cementitious materials and a fine aggregate. The cementitous materials may comprise fly ash as well as cement. The fine aggregate may comprise fly ash as well as sand. The total amount of fly ash in the hardenable mixture ranges from about 60% to about 120% of the total amount of cement, by weight, whether the fly ash is included as a cementious material, fine aggregate, or an additive, or any combination of the foregoing. In specific examples, mortar containing 50% fly ash and 50% cement in cementitious materials demonstrated superior properties of corrosion resistance.

Sulfate and acid resistant concrete and mortar

DOEpatents

Liskowitz, J.W.; Wecharatana, M.; Jaturapitakkul, C.; Cerkanowicz, A.E.

1998-06-30

The present invention relates to concrete, mortar and other hardenable mixtures comprising cement and fly ash for use in construction and other applications, which hardenable mixtures demonstrate significant levels of acid and sulfate resistance while maintaining acceptable compressive strength properties. The acid and sulfate hardenable mixtures of the invention containing fly ash comprise cementitious materials and a fine aggregate. The cementitous materials may comprise fly ash as well as cement. The fine aggregate may comprise fly ash as well as sand. The total amount of fly ash in the hardenable mixture ranges from about 60% to about 120% of the total amount of cement, by weight, whether the fly ash is included as a cementious material, fine aggregate, or an additive, or any combination of the foregoing. In specific examples, mortar containing 50% fly ash and 50% cement in cementitious materials demonstrated superior properties of corrosion resistance. 6 figs.

Effects of nano-SiO(2) and different ash particle sizes on sludge ash-cement mortar.

PubMed

Lin, K L; Chang, W C; Lin, D F; Luo, H L; Tsai, M C

2008-09-01

The effects of nano-SiO(2) on three ash particle sizes in mortar were studied by replacing a portion of the cement with incinerated sewage sludge ash. Results indicate that the amount of water needed at standard consistency increased as more nano-SiO(2) was added. Moreover, a reduction in setting time became noticeable for smaller ash particle sizes. The compressive strength of the ash-cement mortar increased as more nano-SiO(2) was added. Additionally, with 2% nano-SiO(2) added and a cure length of 7 days, the compressive strength of the ash-cement mortar with 1 microm ash particle size was about 1.5 times better that of 75microm particle size. Further, nano-SiO(2) functioned to fill pores for ash-cement mortar with different ash particle sizes. However, the effects of this pore-filling varied with ash particle size. Higher amounts of nano-SiO(2) better influenced the ash-cement mortar with larger ash particle sizes.

Use of Artificial Neural Network for the Simulation of Radon Emission Concentration of Granulated Blast Furnace Slag Mortar.

PubMed

Jang, Hong-Seok; Xing, Shuli; Lee, Malrey; Lee, Young-Keun; So, Seung-Young

2016-05-01

In this study, an artificial neural networks study was carried out to predict the quantity of radon of Granulated Blast Furnace Slag (GBFS) cement mortar. A data set of a laboratory work, in which a total of 3 mortars were produced, was utilized in the Artificial Neural Networks (ANNs) study. The mortar mixture parameters were three different GBFS ratios (0%, 20%, 40%). Measurement radon of moist cured specimens was measured at 3, 10, 30, 100, 365 days by sensing technology for continuous monitoring of indoor air quality (IAQ). ANN model is constructed, trained and tested using these data. The data used in the ANN model are arranged in a format of two input parameters that cover the cement, GBFS and age of samples and, an output parameter which is concentrations of radon emission of mortar. The results showed that ANN can be an alternative approach for the predicting the radon concentration of GBFS mortar using mortar ingredients as input parameters.

Mineralogical characterization of rendering mortars from decorative details of a baroque building in Kozuchow (SW Poland)

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

Bartz, W., E-mail: wojciech.bartz@ing.uni.wroc.pl; Filar, T.

Optical microscopic observations, scanning electron microscopy and microprobe with energy dispersive X-ray analysis, X-ray diffraction and differential thermal/thermogravimetric analysis allowed detailed characterization of rendering mortars from decorative details (figures of Saints) of a baroque building in Kozuchow (Lubuskie Voivodship, Western Poland). Two separate coats of rendering mortars have been distinguished, differing in composition of their filler. The under coat mortar has filler composed of coarse-grained siliceous sand, whereas the finishing one has much finer grained filler, dominated by a mixture of charcoal and Fe-smelting slag, with minor amounts of quartz grains. Both mortars have air-hardening binder composed of gypsum andmore » micritic calcite, exhibiting microcrystalline structure.« less

[Study on the mechanism of liesegang pattern development during carbonating of traditional sticky rice-lime mortar].

PubMed

Wei, Guo-feng; Fang, Shi-qiang; Zhang, Bing-jian; Wang, Xiao-qi; Li, Zu-guang

2012-08-01

Liesegang patterns in traditional sticky rice-lime mortar undergoing carbonation were investigated by means of FTIR, XRD and SEM. Results indicate that well-developed Liesegang patterns only occur in the mortar prepared with aged lime and sticky rice. The smaller Ca(OH)2 particle size in aged lime and the control of the sticky rice for the crystallization of calcium carbonate lead to the small pores in this mortar. These small pores can make Ca2+ and CO3(2-) highly supersaturated, which explains the reason why Liesegang pattern developed in the sticky rice-aged lime mortar. The formed metastable aragonite proves that Liesegang pattern could be explained based on the post-nucleation theory.

Formulation and characterization of date palm fibers mortar by addition of silica fume

NASA Astrophysics Data System (ADS)

Mokhtari, A.; Kriker, A.; Ouaggad, H.; Merad, N.

2018-05-01

This paper presents the results of experimental investigations of the formulated and characterization of date palm fibers mortar by addition of silica fume. The use of addition mineral is widely used in the production of cements through the world. The objective of this work is to bring our contribution to the recovery of local resources in the occurrence vegetable fibers of date palm to weak cost and from renewable source and integrate it in the filled of building. Date palm fiber are from Ouargla town in south of Algeria. Different mortar mixtures were prepared in which the cement was substitute by 10% of silica fume. The mechanical characteristics (compressive and flexural strength) of date palm fibers mortar by treatment of the matrix by the adding of silica fume were examined. The results obtained have shown that the mortar workability as well as the compressive and flexural strength decreases with increasing the silica fume replacement. The results showed that the use of silica fume enabled to evaluate the flexural strength. However, another treatment of fibers and matrix will be recommended for Improved the characteristics.

Quantitative sensing of corroded steel rebar embedded in cement mortar specimens using ultrasonic testing

NASA Astrophysics Data System (ADS)

Owusu Twumasi, Jones; Le, Viet; Tang, Qixiang; Yu, Tzuyang

2016-04-01

Corrosion of steel reinforcing bars (rebars) is the primary cause for the deterioration of reinforced concrete structures. Traditional corrosion monitoring methods such as half-cell potential and linear polarization resistance can only detect the presence of corrosion but cannot quantify it. This study presents an experimental investigation of quantifying degree of corrosion of steel rebar inside cement mortar specimens using ultrasonic testing (UT). A UT device with two 54 kHz transducers was used to measure ultrasonic pulse velocity (UPV) of cement mortar, uncorroded and corroded reinforced cement mortar specimens, utilizing the direct transmission method. The results obtained from the study show that UPV decreases linearly with increase in degree of corrosion and corrosion-induced cracks (surface cracks). With respect to quantifying the degree of corrosion, a model was developed by simultaneously fitting UPV and surface crack width measurements to a two-parameter linear model. The proposed model can be used for predicting the degree of corrosion of steel rebar embedded in cement mortar under similar conditions used in this study up to 3.03%. Furthermore, the modeling approach can be applied to corroded reinforced concrete specimens with additional modification. The findings from this study show that UT has the potential of quantifying the degree of corrosion inside reinforced cement mortar specimens.

The effects of different types of nano-silicon dioxide additives on the properties of sludge ash mortar.

PubMed

Luo, Huan-Lin; Chang, Wei-Che; Lin, Deng-Fong

2009-04-01

To improve the drawbacks caused by the sludge ash replacement in mortar, the previous studies have shown that the early strength and durability of sludge ash/cement mortar are improved by adding nano-silicon dioxide (nano-SiO2) to mortar. In this article, three types of nano-SiO2--SS, HS, and SP (manufacturer code names)--were applied to sludge ash/cement mixture to make paste or mortar specimens. The object is to further extend the recycle of the sludge ash by determining the better type of nano-SiO2 additive to improve properties of sludge ash/ cement paste or mortar. The cement was replaced by 0, 10, 20, and 30% of sludge ash, and 0 and 2% of nano-SiO2 additives were added to the sludge ash paste or mortar specimens. Tests such as setting time, compressive strength, scanning electron microscopy, X-ray diffraction, nuclear magnetic resonance, and thermogravimetric analysis/differential thermal analysis were performed in this study. Test results show that nano-SiO2 additives can not only effectively increase the hydration product (calcium silicate hydrate [C-S-H] gel), but also make the crystal structure denser. Among the three types of nano-SiO2 additive, the SS type can best improve the properties of sludge ash/cement paste or mortar, followed by the SP and HS types.

Utilization of recycled cathode ray tubes glass in cement mortar for X-ray radiation-shielding applications.

PubMed

Ling, Tung-Chai; Poon, Chi-Sun; Lam, Wai-Shung; Chan, Tai-Po; Fung, Karl Ka-Lok

2012-01-15

Recycled glass derived from cathode ray tubes (CRT) glass with a specific gravity of approximately 3.0 g/cm(3) can be potentially suitable to be used as fine aggregate for preparing cement mortars for X-ray radiation-shielding applications. In this work, the effects of using crushed glass derived from crushed CRT funnel glass (both acid washed and unwashed) and crushed ordinary beverage container glass at different replacement levels (0%, 25%, 50%, 75% and 100% by volume) of sand on the mechanical properties (strength and density) and radiation-shielding performance of the cement-sand mortars were studied. The results show that all the prepared mortars had compressive strength values greater than 30 MPa which are suitable for most building applications based on ASTM C 270. The density and shielding performance of the mortar prepared with ordinary crushed (lead-free) glass was similar to the control mortar. However, a significant enhancement of radiation-shielding was achieved when the CRT glasses were used due to the presence of lead in the glass. In addition, the radiation shielding contribution of CRT glasses was more pronounced when the mortar was subject to a higher level of X-ray energy. Copyright © 2011 Elsevier B.V. All rights reserved.

Self-leveling mortar as a possible cause of symptoms associated with "sick building syndrome".

PubMed

Lundholm, M; Lavrell, G; Mathiasson, L

1990-01-01

In newly constructed houses and buildings in which self-leveling mortar containing casein has been used, residents and office employees have noted a bad odor and have complained of headache, eye and throat irritation, and tiredness. These problems were suspected to result from the degradation products emitted from the mortar. Samples obtained from dry mortar powder and from mortar in buildings where casein was used and from control buildings were found to contain microorganisms (mean of 10(2) culture forming units/g). Environmental species were predominantly found, e.g., Bacillus, Clostridium, Micrococcus, and Propionibacterium. Fungi were found occasionally; no evidence of bacterial degradation was found. Headspace and gas chromatographic-mass spectrometric analysis of air from the newly constructed houses and from hydroxide-degraded casein revealed the presence of amines in the 0.003-0.013 ppm range and the presence of ammonia and sulfhydryl compounds, all of which in low concentrations can cause the symptoms observed. These substances, however, were not detected in control buildings.

Brick-and-Mortar Self-Assembly Approach to Graphitic Mesoporous Carbon Nanocomposites

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

Dai, Sheng; Fulvio, Pasquale F; Mayes, Richard T

2011-01-01

Mesoporous carbon materials do not have sufficient ordering at the atomic scale to exhibit good electronic conductivity. To date, mesoporous carbons having uniform mesopores and high surface areas have been prepared from partially-graphitizable precursors in the presence of templates. High temperature thermal treatments above 2000 C, which are usually required to increase conductivity, result in a partial or total collapse of the mesoporous structures and reduced surface areas induced by growth of graphitic domains, limiting their applications in electric double layer capacitors and lithium-ion batteries. In this work, we successfully implemented a 'brick-and-mortar' approach to obtain ordered graphitic mesoporous carbonmore » nanocomposites with tunable mesopore sizes below 850 C without using graphitization catalysts or high temperature thermal treatments. Phenolic resin-based mesoporous carbons act as mortar to highly conductive carbon blacks and carbon onions (bricks). The capacitance and resistivity of final materials can be tailored by changing the mortar to brick ratios.« less

Experimental Study of the Possibility to Make a Mortar with Ternary Sand (Natural and Artificial Fine Aggregates)

NASA Astrophysics Data System (ADS)

Baali, L.; Naceri, A.; Rahmouni, Z.; Mehidi, M. W. Noui

This experimental study investigates the possibility to make a mortar with a ternary sand (natural and artificial fine aggregates). This method is utilized to correct the particle size distribution of various sands used in mortar. For this investigation, three sands have been used: a dune sand (DS), a slag sand (SS), and brick sand (BS) at different proportions in mortar. After crushing, the artificial fine aggregate (blast furnace slag and waste brick fine aggregate) was sifted in order to use it as fine aggregate. The effect of the quality and grain size distribution of natural fine aggregate (i.e., DS) and artificial fine aggregates (i.e., SS and BS) on the physical properties of ternary sand confected (density, porosity, fineness modulus, equivalent sand, particle size distribution, water absorption) and properties of fresh and hardened mortar were analysed. In the same way for this study, the physical properties and chemical compositions of DS, SS, BS and cement were investigated. The results obtained show that the mechanical strength on mortar depends of the nature and particle size distribution of sand studied. The reuse of this recycled material (slag blast furnace and waste brick) in the industry would contribute to the protection of the environment. This study shows the potential of this method to make mortar with ternary sand (natural and artificial fine aggreagates) in order to improve the physical properties of sand. Utilising natural and artificial fine aggregates to produce quality mortar should yield significant environmental benefits.

Utilization of recycled glass derived from cathode ray tube glass as fine aggregate in cement mortar.

PubMed

Ling, Tung-Chai; Poon, Chi-Sun

2011-08-30

Rapid advances in the electronic industry led to an excessive amount of early disposal of older electronic devices such as computer monitors and old televisions (TV) before the end of their useful life. The management of cathode ray tubes (CRT), which have been a key component in computer monitors and TV sets, has become a major environmental problem worldwide. Therefore, there is a pressing need to develop sustainable alternative methods to manage hazardous CRT glass waste. This study assesses the feasibility of utilizing CRT glass as a substitute for natural aggregates in cement mortar. The CRT glass investigated was an acid-washed funnel glass of dismantled CRT from computer monitors and old TV sets. The mechanical properties of mortar mixes containing 0%, 25%, 50%, 75% and 100% of CRT glass were investigated. The potential of the alkali-silica reaction (ASR) and leachability of lead were also evaluated. The results confirmed that the properties of the mortar mixes prepared with CRT glass was similar to that of the control mortar using sand as fine aggregate, and displayed innocuous behaviour in the ASR expansion test. Incorporating CRT glass in cement mortar successfully prevented the leaching of lead. We conclude that it is feasible to utilize CRT glass in cement mortar production. Copyright © 2011 Elsevier B.V. All rights reserved.

Classifiers utilized to enhance acoustic based sensors to identify round types of artillery/mortar

NASA Astrophysics Data System (ADS)

Grasing, David; Desai, Sachi; Morcos, Amir

2008-04-01

Feature extraction methods based on the statistical analysis of the change in event pressure levels over a period and the level of ambient pressure excitation facilitate the development of a robust classification algorithm. The features reliably discriminates mortar and artillery variants via acoustic signals produced during the launch events. Utilizing acoustic sensors to exploit the sound waveform generated from the blast for the identification of mortar and artillery variants as type A, etcetera through analysis of the waveform. Distinct characteristics arise within the different mortar/artillery variants because varying HE mortar payloads and related charges emphasize varying size events at launch. The waveform holds various harmonic properties distinct to a given mortar/artillery variant that through advanced signal processing and data mining techniques can employed to classify a given type. The skewness and other statistical processing techniques are used to extract the predominant components from the acoustic signatures at ranges exceeding 3000m. Exploiting these techniques will help develop a feature set highly independent of range, providing discrimination based on acoustic elements of the blast wave. Highly reliable discrimination will be achieved with a feedforward neural network classifier trained on a feature space derived from the distribution of statistical coefficients, frequency spectrum, and higher frequency details found within different energy bands. The processes that are described herein extend current technologies, which emphasis acoustic sensor systems to provide such situational awareness.

Strength Performance of Blended Ash Based Geopolymer Mortar

NASA Astrophysics Data System (ADS)

Zahib, Zaidahtulakmal M.; Kamaruddin, Kartini; Saman, Hamidah M.

2018-03-01

Geopolymer is a based on inorganic alumino-silicate binder system. Geopolymeric materials are formed using materials that containing silica and aluminium such as fly ash and rice husk ash, which activated by alkaline solution. This paper presents the study on the effect of replacement of SSA in RHA based geopolymer, types of curing and different molarity of NaOH used on the strength of Sewage Sludge Ash (SSA) and Rice Husk Ash (RHA) based geopolymer mortar incorporating with three (3) different mix proportions. Based geopolymer mortar was synthesized from treated sewage sludge and rice husk undergoing incineration process in producing ashes, activated with sodium silicate and sodium hydroxide solution by ratio of 2.5:1 and solution to ash ratio of 1:1. Molarity of 8M and 10M NaOH were used. The percentages of SSA replacement were 0%, 10% and 20% by weight. Compressive strength was conducted at age 7, 14 and 28 days to see the development of strength with two curing regimes, which are air curing and oven curing (60°C for 24 hours). From the research conducted, the ultimate compressive strength (6.28MPa) was obtained at zero replacement of SSA taken at 28 days of oven curing with 10M of NaOH. This shows that RHA, which is rich in silica content is enough to enhance the strength of geopolymer mortar especially with high molarity of NaOH.

The comparison of properties and cost of material use of natural rubber and sand in manufacturing cement mortar for construction sub-base layer

NASA Astrophysics Data System (ADS)

Rahman, R.; Nemmang, M. S.; Hazurina, Nor; Shahidan, S.; Khairul Tajuddin Jemain, Raden; Abdullah, M. E.; Hassan, M. F.

2017-11-01

The main issue related to this research was to examine the feasibility of natural rubber SMR 20 in the manufacturing of cement mortar for sub-base layer construction. Subbase layers have certain functions that need to be fulfilled in order to assure strong and adequate permeability of pavement performance. In a pavement structure, sub-base is below the base and serves as the foundation for the overall pavement structure, transmitting traffic loads to the sub-grade and providing drainage. Based on this research, the natural rubber, SMR 20 was with the percentages of 0%, 5%, 10% and 15% to mix with sand in the manufacture of the cement mortar. This research describes some of the properties and cost of the materials for the natural rubber and sand in cement mortar manufacturing by laboratory testing. Effects of the natural rubber replacement on mechanical properties of mortar were investigated by laboratory testing such as compressive strength test and density. This study obtained the 5% of natural rubber replaced in sand can achieved the strength of normal mortar after 7 days and 28 days. The strength of cement mortar depends on the density of cement mortar. According to the cost of both materials, sand shows the lower cost in material for the cement mortar manufacturing than the uses of natural rubber. Thus, the convectional cement mortar which used sand need lower cost than the modified rubber cement mortar and the most economical to apply in industrial. As conclusion, the percentage of 5% natural rubber in the cement mortar would have the same with normal cement mortar in terms of the strength. However, in terms of the cost of the construction, it will increase higher than cost of normal cement mortar production. So that, this modified cement mortar is not economical for the road sub-base construction.

The Market Gate of Miletus: damages, material characteristics and the development of a compatible mortar for restoration

NASA Astrophysics Data System (ADS)

Siegesmund, Siegfried; Middendorf, Bernhard

2008-12-01

The indoor exhibit of the Market Gate of Miletus is unique for an archaeological monument. The reconstruction of the gate was done in such a way that most marble fragments were removed leaving cored marble columns 3-4 cm in thickness. These cored columns were mounted on a steel construction and filled with different mortars or filled with specially shaped blocks of brick combined with mortar. All the missing marble elements were replaced by copies made of a Portland cement based concrete, which is compositionally similar to the original building materials. During the Second World War the monument was heavily damaged by aerial bombardment. For 2 years the Market Gate of Miletus was exposed to weathering, because a brick wall protecting the gate was also destroyed. The deterioration phenomena observed are microcracks, macroscopic fractures, flaking, sugaring, greying, salt efflorescence, calcitic-sinter layers and iron oxide formation etc. The rapid deterioration seems to be due to indoor atmospheric effects, and also by a combination of incompatible materials (e.g. marble, steel, mortar, concrete, bricks etc.). Compatible building materials like mortars or stone replacing materials have to be developed for the planned restoration. The requirements for restoration mortars are chemical-mineralogical and physical-mechanical compatibilities with the existing building materials. In detail this means that the mortar should ensure good bonding properties, adapted strength development and not stain the marble when in direct contact. The favoured mortar was developed with a hydraulic binder based on iron-free white cement and pozzolana based on activated clay. A special limestone and quartz sand mixture was used as an aggregate. The cement was adjusted using chemical additives. Specially designed tests were applied extensively to prove whether the developed mortar is suitable for the restoration of this precious monument.

Scaling of strength and ductility in bioinspired brick and mortar composites

NASA Astrophysics Data System (ADS)

Wilbrink, David V.; Utz, Marcel; Ritchie, Robert O.; Begley, Matthew R.

2010-11-01

This paper provides scaling relationships between constituent properties and the uniaxial tensile response of synthetic "brick and mortar" composite materials inspired by nacre. The macroscopic strength and ductility (work of fracture) are predicted in terms of the brick properties (size, strength, and layout) and interface cohesive properties (e.g., maximum shear and normal stresses and separations). The results illustrate the trade-off between increasing strength and decreasing ductility with the increasing aspect ratio of the bricks. The models can be used to identify optimum mortar properties that maximize toughness for a given brick strength.

Effect of various superplasticizers on rheological properties of cement paste and mortars

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

Masood, I.; Agarwal, S.K.

The effect of eight commercial superplasticizers including one developed from Cashew Nut Shell Liquid (CNSL) at CBRI on the rheological properties viz. viscosity and flow of cement paste and mortars have been investigated. The viscosity measurements have been made at various shear rates (5--100 rpm). It is found that at higher rates (100 rpm) even with the low concentration of superplasticizers (0.1), the viscosity of the cement paste is more or less the same as that obtained with 0.6 % dosages of SPs at lesser shear rates. The effect of split addition (delayed addition) of superplasticizers on viscosity of cementmore » paste and 1:3 cement sand mortar have also been studied. A decrease in viscosity due to split addition has been observed in the cement paste and there is an increase of 15--20 % in flow of mortars.« less

Advanced mortar coatings for cultural heritage protection. Durability towards prolonged UV and outdoor exposure.

PubMed

Pino, F; Fermo, P; La Russa, M; Ruffolo, S; Comite, V; Baghdachi, J; Pecchioni, E; Fratini, F; Cappelletti, G

2017-05-01

In the present work, two kinds of hybrid polymeric-inorganic coatings containing TiO 2 or SiO 2 particles and prepared starting from two commercial resins (Alpha®SI30 and Bluesil®BP9710) were developed and applied to two kinds of mortars (an air-hardening calcic lime mortar [ALM] and a natural hydraulic lime mortar [HLM]) to achieve better performances in terms of water repellence and consequently damage resistance. The two pure commercial resins were also applied for comparison purposes. Properties of the coated materials and their performance were studied using different techniques such as contact angle measurements, capillary absorption test, mercury intrusion porosimetry, surface free energy, colorimetric measurements and water vapour permeability tests. Tests were also performed to determine the weathering effects on both the commercial and the hybrid coatings in order to study their durability. Thus, exposures to UV radiation, to UV radiation/condensed water cycles and to a real polluted atmospheric environment have been performed. The effectiveness of the hybrid SiO 2 based coating was demonstrated, especially in the case of the HLM mortar.

[Based on Curing Age of Calcined Coal Gangue Fine Aggregate Mortar of X-Ray Diffraction and Scanning Electron Microscopy Analysis].

PubMed

Dong, Zuo-chao; Xia, Jun-wu; Duan, Xiao-mu; Cao, Ji-chang

2016-03-01

By using X-ray diffraction (XRD) and environmental scanning electron microscope (SEM) analysis method, we stud- ied the activity of coal gangue fine aggregate under different calcination temperature. In view of the activity of the highest-700 degrees C high temperature calcined coal gangue fine aggregate mortar of hydration products, microstructure and strength were discussed in this paper, and the change laws of mortar strength with curing age (3, 7, 14, 28, 60 and 90 d) growth were analyzed. Test results showed that coal gangue fine aggregate with the increase of calcination temperature, the active gradually increases. When the calcination temperature reaches 700 degrees C, the activity of coal gangue fine aggregate is the highest. When calcining temperature continues to rise, activity falls. After 700 degrees C high temperature calcined coal gangue fine aggregate has obvious ash activity, the active components of SiO2 and Al2 O3 can be with cement hydration products in a certain degree of secondary hydration reaction. Through on the top of the activity of different curing age 700 degrees C high temperature calcined coal gangue fine aggregate mortar, XRD and SEM analysis showed that with the increase of curing age, secondary hydration reaction will be more fully, and the amount of hydration products also gradually increases. Compared with the early ages of the cement mortar, the products are more stable hydration products filling in mortar microscopic pore, which can further improve the microstructure of mortar, strengthen the interface performance of the mortar. The mortar internal structure is more uniform, calcined coal gangue fine aggregate and cement mortar are more of a strong continuous whole, which increase the later strength of hardened cement mortar, 700 degrees C high temperature calcined coal gangue fine aggregate pozzolanic effect is obvious.

Fentanyl patches: preventable overdose.

PubMed

2010-02-01

Fentanyl is a potent opioid analgesic marketed for the treatment of stable intense chronic pain, particularly in the form of a transdermal patch. These delivery devices carry the same risk of adverse effects and drug interactions as conventional formulations of opioids. The patches carry an added risk of fentanyl overdose because they contain very high doses, both before and after use. High-risk situations for overdose were identified by examining the results of pharmacovigilance studies and medication error prevention programmes, as well as an observational study, case reports, and a French legal action. The main situations exposing patients to a risk of overdose are: confusion between two dose strengths, forgetting to remove the patch; accidental transfer of the patch to another person, application of more than one patch, cutting the patches, self-medication, and ingestion. Increased skin temperature facilitates fentanyl absorption and thus increases the risk of overdose; high-risk situations include fever, electric blankets, and intense physical exercise. In practice, the precautions for treatment and patch disposal must be followed exactly if this delivery system is to serve as a valid alternative to morphine for selected patients with stable intense chronic pain.

Coupled Effect of Elevated Temperature and Cooling Conditions on the Properties of Ground Clay Brick Mortars

NASA Astrophysics Data System (ADS)

Ali Abd El Aziz, Magdy; Abdelaleem, Salh; Heikal, Mohamed

2013-12-01

When a concrete structure is exposed to fire and cooling, some deterioration in its chemical resistivity and mechanical properties takes place. This deterioration can reach a level at which the structure may have to be thoroughly renovated or completely replaced. In this investigation, four types of cement mortars, ground clay bricks (GCB)/sand namely 0/3, 1/2, 2/1 and 3/0, were used. Three different cement contents were used: 350, 400 and 450 kg/m3. All the mortars were prepared and cured in tap water for 3 months and then kept in laboratory atmospheric conditions up to 6 months. The specimens were subjected to elevated temperatures up to 700°C for 3h and then cooled by three different conditions: water, furnace, and air cooling. The results show that all the mortars subjected to fire, irrespective of cooling mode, suffered a significant reduction in compressive strength. However, the mortars cooled in air exhibited a relativity higher reduction in compressive strength rather than those water or furnace cooled. The mortars containing GCB/sand (3/0) and GCB/sand (1/2) exhibited a relatively higher thermal stability than the others.

Laboratory investigation of air-void systems produced by air-entraining admixtures in fresh and hardened mortar.

DOT National Transportation Integrated Search

2006-01-01

The air-void systems produced by two commercially available air-entraining admixtures (AEA), one a vinsol resin formulation and the other a tall oil formulation, were studied in mortars. Mortars were composed of four different portland cements and tw...

PATCH image processor user's manual

NASA Technical Reports Server (NTRS)

Nieves, M. J. (Principal Investigator)

1980-01-01

The patch image processor extracts patches in various size (32 x 32, 64 x 64, 128 x 128, and 256 x 256 pixels) from full frame LANDSAT imagery data. With the patches that are extracted, a patch image mosaic is created in the image processing system, IMDACS, format.

Performance Characteristics of Waste Glass Powder Substituting Portland Cement in Mortar Mixtures

NASA Astrophysics Data System (ADS)

Kara, P.; Csetényi, L. J.; Borosnyói, A.

2016-04-01

In the present work, soda-lime glass cullet (flint, amber, green) and special glass cullet (soda-alkaline earth-silicate glass coming from low pressure mercury-discharge lamp cullet and incandescent light bulb borosilicate glass waste cullet) were ground into fine powders in a laboratory planetary ball mill for 30 minutes. CEM I 42.5N Portland cement was applied in mortar mixtures, substituted with waste glass powder at levels of 20% and 30%. Characterisation and testing of waste glass powders included fineness by laser diffraction particle size analysis, specific surface area by nitrogen adsorption technique, particle density by pycnometry and chemical analysis by X-ray fluorescence spectrophotometry. Compressive strength, early age shrinkage cracking and drying shrinkage tests, heat of hydration of mortars, temperature of hydration, X-ray diffraction analysis and volume stability tests were performed to observe the influence of waste glass powder substitution for Portland cement on physical and engineering properties of mortar mixtures.

Comparative Effect of Bio-waste Ashes on Strength Properties of Cement Mortar

NASA Astrophysics Data System (ADS)

Ajay, Goyal; Hattori, Kunio; Ogata, Hidehiko; Ashraf, Muhammad; Ahmed, Mohamed Anwar

Biomass fuels produce about 400 million tonnes of ashes as waste material. This paper discusses the pozzolanic character of bio-waste ashes obtained from dry tree leaves (AML), Korai grass (KRI) and Tifton grass (TFT). Ashes were obtained by control incineration of the wastes at 600°C for 5 hours and mortar specimens were prepared by substituting cement with 10, 20 and 30% ash. Strength development of ash-blended mortar specimens was evaluated by conducting destructive tests as well as non-destructive tests till 91 days. X-ray diffraction, scanning electron microscopic and thermo-gravimetric techniques were used to analyze the influence of ash substitution on strength properties of blended-mortar. Pozzolanic reactivity of AML- and KRI-ash was confirmed, but TFT-ash did not show enough reactivity. Overall results confirmed that up to 20% substitution of cement can be made with AML- or KRI-ash with strength approaching 90% of that of control.

Optimization of superplasticizer in portland pozzolana cement mortar and concrete

NASA Astrophysics Data System (ADS)

Sathyan, Dhanya; Anand, K. B.; Mini, K. M.; Aparna, S.

2018-02-01

Chemical Admixtures are added to concrete at the time of mixing of its constituents to impart workability. The requirement of right workability is the essence of good concrete. It has been found that the use of optimum use of admixtures is very important since low dosage may result in loss of fluidity and over dosage could lead to segregation, bleeding, excessive air entrainment etc in concrete. Hence it is essential to find optimum dosage of superplasticizer for getting good strength and workability. But large number of trial tests are required in the field to find the saturation dosage of superplasticizer in concrete which requires more materials and consume more time. The paper deals with developing a co-relation between the quantity requirements of superplasticiser in mortar to that of cement concrete to get good workability. In this work for preparing mortar and concrete 4 brands of locally available Portland pozzolana cement (PPC) and superplasticizer (SP) belonging to 4 different families namely Polycarboxylate Ether (PCE), Lignosulphate (LS), Sulfonated Naphthalene Formaldehyde (SNF) and Sulfonated Melamine Formaldehyde (SMF) are used. Two different brands of SP’s are taken from each family. Workability study on the superplasticized mortar with cement to sand ratio 1:1.5 and water cement ratio of 0.4 was performed using marsh cone and flow table test and workability study on the concrete with same cement/sand ratio and water cement ratio was done using slump cone and flow table test. Saturation dosage of superplasticizer in mortar and concrete determined experimentally was compared to study the correlation between two. Compressive strength study on concrete cubes were done on concrete mixes with a superplasticizer dosage corresponding to the saturation dosage and a comparative study were done to analyse the improvement in the compressive strength with addition of superplasticizer from different family.

Estradiol Transdermal Patch

MedlinePlus

Most brands of estradiol transdermal patches are used to treat hot flushes (hot flashes; sudden strong feelings of heat ... different medication that does not contain estrogen. Most brands of estradiol transdermal patches are also sometimes used ...

Ethinyl Estradiol and Norelgestromin Transdermal Patch

MedlinePlus

... the skin. One patch is applied once a week for 3 weeks, followed by a patch-free week. Follow the directions on your prescription label carefully, ... new patch on the same day of the week (the Patch Change Day). Apply a new patch ...

The Study on Development of Light-Weight Foamed Mortar for Tunnel Backfill

NASA Astrophysics Data System (ADS)

Ma, Sang-Joon; Kang, Eun-Gu; Kim, Dong-Min

This study was intended to develop the Light-Weight Foamed Mortar which is used for NATM Composite lining backfill. In the wake of the study, the mixing method which satisfies the requirements for compressive strength, permeability coefficient, fluidity, specific gravity and settlement was developed and moreover field applicability was verified through the model test. Thus the mixing of Light-Weight Foamed Mortar developed in this study is expected to be applicable to NATM Composite lining, thereby making commitment to improving the stability and drainage performance of lining.

Sperm Patch-Clamp

PubMed Central

Lishko, Polina; Clapham, David E.; Navarro, Betsy; Kirichok, Yuriy

2014-01-01

Sperm intracellular pH and calcium concentration ([Ca2+]i) are two central factors that control sperm activity within the female reproductive tract. As such, the ion channels of the sperm plasma membrane that alter intracellular sperm [Ca2+] and pH play important roles in sperm physiology and the process of fertilization. Indeed, sperm ion channels regulate sperm motility, control sperm chemotaxis toward the egg in some species, and may trigger the acrosome reaction. Until recently, our understanding of these important molecules was rudimentary due to the inability to patch-clamp spermatozoa and directly record the activity of these ion channels under voltage clamp. Recently, we overcame this technical barrier and developed a method for reproducible application of the patch-clamp technique to mouse and human spermatozoa. This chapter covers important aspects of application of the patch-clamp technique to spermatozoa, such as selection of the electrophysiological equipment, isolation of spermatozoa for patch-clamp experiments, formation of the gigaohm seal with spermatozoa, and transition into the whole-cell mode of recording. We also discuss potential pitfalls in application of the patch-clamp technique to flagellar ion channels. PMID:23522465

Fatigue behaviour analysis for the durability prequalification of strengthening mortars

NASA Astrophysics Data System (ADS)

Bocca, P.; Grazzini, A.; Masera, D.

2011-07-01

An innovative laboratory procedure used as a preliminary design stage for the pre-qualification of strengthening mortars applied to historical masonry buildings is described. In the analysis of the behaviour of masonry structures and their constituent materials, increasing importance has been assumed by the study of the long-term evolution of deformation and mechanical characteristics, which may be affected by both loading and environmental conditions. Through static and fatigue tests on mixed specimens historical brick-reinforced mortar it has been possible to investigate the durability of strengthening materials, in order to select, from a range of alternatives, the most suitable for the historical masonry. Cyclic fatigue stress has been applied to accelerate the static creep and to forecast the corresponding creep behaviour of the historical brick-strengthening mortar system under static long-time loading. This methodology has proved useful in avoiding the errors associated with materials that are not mechanically compatible and guarantees the durability of strengthening work. The experimental procedure has been used effectively in the biggest restoration building site in Europe, the Royal Palace of Venaria, and it is in progress of carrying out at the Special Natural Reserve of the Sacro Monte di Varallo, in Piedmont (Italy).

Isotopic analysis for degradation diagnosis of calcite matrix in mortar.

PubMed

Dotsika, E; Psomiadis, D; Poutoukis, D; Raco, B; Gamaletsos, P

2009-12-01

Mortar that was used in building as well as in conservation and restoration works of wall paintings have been analysed isotopically (delta(13)C and delta(18)O) in order to evaluate the setting environments and secondary processes, to distinguish the structural components used and to determine the exact causes that incurred the degradation phenomena. The material undergoes weathering and decay on a large proportion of its surface and in depth, due to the infiltration of water through the structural blocks. Mineralogical analysis indicated signs of sulphation and dissolution/recrystallisation processes taking place on the material, whereas stable isotopes provided information relative to the origin of the CO(2) and water during calcite formation and degradation processes. Isotopic change of the initial delta(13)C and delta(18)O in carbonate matrix was caused by alteration of the primary source of CO(2) and H(2)O in mortar over time, particularly by recrystallisation of calcite with porewater, evaporated or re-condensed water, and CO(2) from various sources of atmospheric and biogenic origin. Human influence (surface treatment) and biological growth (e.g. fungus) are major exogenic processes which may alter delta(18)O and delta(13)C in lime mortar.

PlenoPatch: Patch-Based Plenoptic Image Manipulation.

PubMed

Zhang, Fang-Lue; Wang, Jue; Shechtman, Eli; Zhou, Zi-Ye; Shi, Jia-Xin; Hu, Shi-Min

2017-05-01

Patch-based image synthesis methods have been successfully applied for various editing tasks on still images, videos and stereo pairs. In this work we extend patch-based synthesis to plenoptic images captured by consumer-level lenselet-based devices for interactive, efficient light field editing. In our method the light field is represented as a set of images captured from different viewpoints. We decompose the central view into different depth layers, and present it to the user for specifying the editing goals. Given an editing task, our method performs patch-based image synthesis on all affected layers of the central view, and then propagates the edits to all other views. Interaction is done through a conventional 2D image editing user interface that is familiar to novice users. Our method correctly handles object boundary occlusion with semi-transparency, thus can generate more realistic results than previous methods. We demonstrate compelling results on a wide range of applications such as hole-filling, object reshuffling and resizing, changing object depth, light field upscaling and parallax magnification.

An Experimental Study of Mortars with Recycled Ceramic Aggregates: Deduction and Prediction of the Stress-Strain.

PubMed

Cabrera-Covarrubias, Francisca Guadalupe; Gómez-Soberón, José Manuel; Almaral-Sánchez, Jorge Luis; Arredondo-Rea, Susana Paola; Gómez-Soberón, María Consolación; Corral-Higuera, Ramón

2016-12-21

The difficult current environmental situation, caused by construction industry residues containing ceramic materials, could be improved by using these materials as recycled aggregates in mortars, with their processing causing a reduction in their use in landfill, contributing to recycling and also minimizing the consumption of virgin materials. Although some research is currently being carried out into recycled mortars, little is known about their stress-strain (σ-ε); therefore, this work will provide the experimental results obtained from recycled mortars with recycled ceramic aggregates (with contents of 0%, 10%, 20%, 30%, 50% and 100%), such as the density and compression strength, as well as the σ-ε curves representative of their behavior. The values obtained from the analytical process of the results in order to finally obtain, through numerical analysis, the equations to predict their behavior (related to their recycled content) are those of: σ (elastic ranges and failure maximum), ε (elastic ranges and failure maximum), and Resilience and Toughness. At the end of the investigation, it is established that mortars with recycled ceramic aggregate contents of up to 20% could be assimilated just like mortars with the usual aggregates, and the obtained prediction equations could be used in cases of similar applications.

An Experimental Study of Mortars with Recycled Ceramic Aggregates: Deduction and Prediction of the Stress-Strain

PubMed Central

Cabrera-Covarrubias, Francisca Guadalupe; Gómez-Soberón, José Manuel; Almaral-Sánchez, Jorge Luis; Arredondo-Rea, Susana Paola; Gómez-Soberón, María Consolación; Corral-Higuera, Ramón

2016-01-01

The difficult current environmental situation, caused by construction industry residues containing ceramic materials, could be improved by using these materials as recycled aggregates in mortars, with their processing causing a reduction in their use in landfill, contributing to recycling and also minimizing the consumption of virgin materials. Although some research is currently being carried out into recycled mortars, little is known about their stress-strain (σ-ε); therefore, this work will provide the experimental results obtained from recycled mortars with recycled ceramic aggregates (with contents of 0%, 10%, 20%, 30%, 50% and 100%), such as the density and compression strength, as well as the σ-ε curves representative of their behavior. The values obtained from the analytical process of the results in order to finally obtain, through numerical analysis, the equations to predict their behavior (related to their recycled content) are those of: σ (elastic ranges and failure maximum), ε (elastic ranges and failure maximum), and Resilience and Toughness. At the end of the investigation, it is established that mortars with recycled ceramic aggregate contents of up to 20% could be assimilated just like mortars with the usual aggregates, and the obtained prediction equations could be used in cases of similar applications. PMID:28774151

The Rejuvenating Effect in Hot Asphalt Recycling by Mortar Transfer Ratio and Image Analysis

PubMed Central

Wang, Fusong; Wang, Zipeng; Li, Chao; Xiao, Yue; Wu, Shaopeng; Pan, Pan

2017-01-01

Using a rejuvenator to improve the performance of asphalt pavement is an effective and economic way of hot asphalt recycling. This research analyzes the rejuvenating effect on aged asphalt by means of a Mortar Transfer Ratio (MTR) test, which concerns the ratio of asphalt mortar that moves from recycled aggregates (RAP aggregates) to fresh added aggregates when aged asphalt is treated with a regenerating agent and comes into contact with fresh aggregates. The proposed MTR test analyzes the regeneration in terms of the softening degree on aged asphalt when the rejuvenator is applied. The covered area ratio is studied with an image analyzing tool to understand the possibility of mortar transferring from RAP aggregates to fresh aggregates. Additionally, a micro-crack closure test is conducted and observed through a microscope. The repairing ability and diffusion characteristics of micro-cracks can therefore be analyzed. The test results demonstrate that the proposed mortar transfer ratio is a feasible way to evaluate rejuvenator diffusion during hot recycling. The mortar transfer ratio and uncovered area ratio on fresh aggregates are compatible, and can be used to quantify the contribution of the rejuvenator. Within a certain temperature range, the diffusing effect of the rejuvenator is better when the diffusing temperature is higher. The diffusion time of the rejuvenator is optimum when diffusion occurs for 4–8 h. When the rejuvenator is properly applied, the rough and cracking surface can be repaired, resulting in better covered aggregates. The micro-closure analysis visually indicates that rejuvenators can be used to repair the RAP aggregates during hot recycling. PMID:28772935

The Rejuvenating Effect in Hot Asphalt Recycling by Mortar Transfer Ratio and Image Analysis.

PubMed

Wang, Fusong; Wang, Zipeng; Li, Chao; Xiao, Yue; Wu, Shaopeng; Pan, Pan

2017-05-24

Using a rejuvenator to improve the performance of asphalt pavement is an effective and economic way of hot asphalt recycling. This research analyzes the rejuvenating effect on aged asphalt by means of a Mortar Transfer Ratio (MTR) test, which concerns the ratio of asphalt mortar that moves from recycled aggregates (RAP aggregates) to fresh added aggregates when aged asphalt is treated with a regenerating agent and comes into contact with fresh aggregates. The proposed MTR test analyzes the regeneration in terms of the softening degree on aged asphalt when the rejuvenator is applied. The covered area ratio is studied with an image analyzing tool to understand the possibility of mortar transferring from RAP aggregates to fresh aggregates. Additionally, a micro-crack closure test is conducted and observed through a microscope. The repairing ability and diffusion characteristics of micro-cracks can therefore be analyzed. The test results demonstrate that the proposed mortar transfer ratio is a feasible way to evaluate rejuvenator diffusion during hot recycling. The mortar transfer ratio and uncovered area ratio on fresh aggregates are compatible, and can be used to quantify the contribution of the rejuvenator. Within a certain temperature range, the diffusing effect of the rejuvenator is better when the diffusing temperature is higher. The diffusion time of the rejuvenator is optimum when diffusion occurs for 4-8 h. When the rejuvenator is properly applied, the rough and cracking surface can be repaired, resulting in better covered aggregates. The micro-closure analysis visually indicates that rejuvenators can be used to repair the RAP aggregates during hot recycling.

Improved Gain Microstrip Patch Antenna

DTIC Science & Technology

2015-08-06

08-2015 Publication Improved Gain Microstrip Patch Antenna David A. Tonn Naval Under Warfare Center Division, Newport 1176 Howell St., Code 00L...GAIN MICROSTRIP PATCH ANTENNA STATEMENT OF GOVERNMENT INTEREST [0001] The invention described herein may be manufactured and used by or for the...patch antenna having increased gain, and an apparatus for increasing the gain and bandwidth of an existing microstrip patch antenna . (2) Description

Impact of Different Binders on the Roughness, Adhesion Strength, and Other Properties of Mortars with Expanded Cork.

PubMed

Barnat-Hunek, Danuta; Widomski, Marcin K; Szafraniec, Małgorzata; Łagód, Grzegorz

2018-03-01

The aim of the research that is presented in this paper was to evaluate the physical and mechanical properties of heat-insulating mortars with expanded cork aggregates and different binders. In this work, the measurements of surface roughness and adhesion strength, supported by determination of basic mechanical and physical parameters, such as density, bulk density, open porosity, total porosity, absorbability, thermal conductivity coefficient, compressive strength, flexural strength, and frost resistance of mortars containing expanded oak cork, were performed. The scanning electron microscope (SEM) investigations demonstrated the microstructure, contact zone, and distribution of pores in the heat-insulating mortars containing expanded cork. The results indicated that the addition of expanded cork and different binders in heat-insulating mortars triggers changes in their roughness and adhesion strength. The SEM research confirmed the very good adhesion of the paste to the cork aggregate.

Impact of Different Binders on the Roughness, Adhesion Strength, and Other Properties of Mortars with Expanded Cork

PubMed Central

Barnat-Hunek, Danuta; Widomski, Marcin K.; Szafraniec, Małgorzata; Łagód, Grzegorz

2018-01-01

The aim of the research that is presented in this paper was to evaluate the physical and mechanical properties of heat-insulating mortars with expanded cork aggregates and different binders. In this work, the measurements of surface roughness and adhesion strength, supported by determination of basic mechanical and physical parameters, such as density, bulk density, open porosity, total porosity, absorbability, thermal conductivity coefficient, compressive strength, flexural strength, and frost resistance of mortars containing expanded oak cork, were performed. The scanning electron microscope (SEM) investigations demonstrated the microstructure, contact zone, and distribution of pores in the heat-insulating mortars containing expanded cork. The results indicated that the addition of expanded cork and different binders in heat-insulating mortars triggers changes in their roughness and adhesion strength. The SEM research confirmed the very good adhesion of the paste to the cork aggregate. PMID:29494525

Assessment and prediction of drying shrinkage cracking in bonded mortar overlays

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

Beushausen, Hans, E-mail: hans.beushausen@uct.ac.za; Chilwesa, Masuzyo

2013-11-15

Restrained drying shrinkage cracking was investigated on composite beams consisting of substrate concrete and bonded mortar overlays, and compared to the performance of the same mortars when subjected to the ring test. Stress development and cracking in the composite specimens were analytically modeled and predicted based on the measurement of relevant time-dependent material properties such as drying shrinkage, elastic modulus, tensile relaxation and tensile strength. Overlay cracking in the composite beams could be very well predicted with the analytical model. The ring test provided a useful qualitative comparison of the cracking performance of the mortars. The duration of curing wasmore » found to only have a minor influence on crack development. This was ascribed to the fact that prolonged curing has a beneficial effect on tensile strength at the onset of stress development, but is in the same time not beneficial to the values of tensile relaxation and elastic modulus. -- Highlights: •Parameter study on material characteristics influencing overlay cracking. •Analytical model gives good quantitative indication of overlay cracking. •Ring test presents good qualitative indication of overlay cracking. •Curing duration has little effect on overlay cracking.« less

Binder characterisation of mortars used at different ages in the San Lorenzo church in Milan

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

Bertolini, Luca, E-mail: luca.bertolini@polimi.it; Carsana, Maddalena, E-mail: maddalena.carsana@polimi.it; Gastaldi, Matteo, E-mail: matteo.gastaldi@polimi.it

The paper describes a study on the mortars of the basilica of San Lorenzo in Milan, which was carried out to support an archaeological study aimed at dating and documenting the construction techniques used throughout the centuries. The church, which was founded between the 4th and 5th century, at the end of the period when Milan was the capital of the Roman Empire, was subjected in time to extensions, collapses and reconstructions that lasted until the Renaissance period and even later on. Thanks to the good state of conservation, San Lorenzo church is a collection of materials and construction techniquesmore » throughout a period of more than a millennium. Mortars were investigated in order to compare the binders used for structural elements built in different historical ages. From an archaeological study, samples of mortars attributed to the late Roman period, the Middle Ages and the Renaissance were available. The binder of each sample was separated by the aggregates and it was characterised on the basis of X-ray diffraction analysis, thermogravimetric analysis and scanning electron microscopy. Constituents of the binder were identified and their origin is discussed in order to investigate if they could be attributed to the original composition of the binder or to possible alteration in time due to atmospheric pollution. Results show that, even though the binder is mainly based on magnesian lime, there are significant differences in the microstructure of the binding matrix used in mortars ascribed to the different historical periods. In the Roman period, in correspondence of the structural elements that required higher strength, also hydraulic cocciopesto mortars were detected. Gypsum was found in most samples, which was maybe added intentionally. - Highlights: • Binders of mortars of San Lorenzo church in Milan were investigated. • Roman, Middle Ages and Renaissance samples were studied by XRD, TG and SEM. • Magnesian-lime binders containing silico

Compressive strength of concrete and mortar containing fly ash

DOEpatents

Liskowitz, J.W.; Wecharatana, M.; Jaturapitakkul, C.; Cerkanowicz, A.E.

1997-04-29

The present invention relates to concrete, mortar and other hardenable mixtures comprising cement and fly ash for use in construction. The invention includes a method for predicting the compressive strength of such a hardenable mixture, which is very important for planning a project. The invention also relates to hardenable mixtures comprising cement and fly ash which can achieve greater compressive strength than hardenable mixtures containing only concrete over the time period relevant for construction. In a specific embodiment, a formula is provided that accurately predicts compressive strength of concrete containing fly ash out to 180 days. In other specific examples, concrete and mortar containing about 15% to 25% fly ash as a replacement for cement, which are capable of meeting design specifications required for building and highway construction, are provided. Such materials can thus significantly reduce construction costs. 33 figs.

Compressive strength of concrete and mortar containing fly ash

DOEpatents

Liskowitz, J.W.; Wecharatana, M.; Jaturapitakkul, C.; Cerkanowicz, A.E.

1998-12-29

The present invention relates to concrete, mortar and other hardenable mixtures comprising cement and fly ash for use in construction. The invention includes a method for predicting the compressive strength of such a hardenable mixture, which is very important for planning a project. The invention also relates to hardenable mixtures comprising cement and fly ash which can achieve greater compressive strength than hardenable mixtures containing only concrete over the time period relevant for construction. In a specific embodiment, a formula is provided that accurately predicts compressive strength of concrete containing fly ash out to 180 days. In other specific examples, concrete and mortar containing about 15% to 25% fly ash as a replacement for cement, which are capable of meeting design specification required for building and highway construction, are provided. Such materials can thus significantly reduce construction costs. 33 figs.

Finite cover method with mortar elements for elastoplasticity problems

NASA Astrophysics Data System (ADS)

Kurumatani, M.; Terada, K.

2005-06-01

Finite cover method (FCM) is extended to elastoplasticity problems. The FCM, which was originally developed under the name of manifold method, has recently been recognized as one of the generalized versions of finite element methods (FEM). Since the mesh for the FCM can be regular and squared regardless of the geometry of structures to be analyzed, structural analysts are released from a burdensome task of generating meshes conforming to physical boundaries. Numerical experiments are carried out to assess the performance of the FCM with such discretization in elastoplasticity problems. Particularly to achieve this accurately, the so-called mortar elements are introduced to impose displacement boundary conditions on the essential boundaries, and displacement compatibility conditions on material interfaces of two-phase materials or on joint surfaces between mutually incompatible meshes. The validity of the mortar approximation is also demonstrated in the elastic-plastic FCM.

Compressive strength of concrete and mortar containing fly ash

DOEpatents

Liskowitz, John W.; Wecharatana, Methi; Jaturapitakkul, Chai; Cerkanowicz, deceased, Anthony E.

1997-01-01

The present invention relates to concrete, mortar and other hardenable mixtures comprising cement and fly ash for use in construction. The invention includes a method for predicting the compressive strength of such a hardenable mixture, which is very important for planning a project. The invention also relates to hardenable mixtures comprising cement and fly ash which can achieve greater compressive strength than hardenable mixtures containing only concrete over the time period relevant for construction. In a specific embodiment, a formula is provided that accurately predicts compressive strength of concrete containing fly ash out to 180 days. In other specific examples, concrete and mortar containing about 15% to 25% fly ash as a replacement for cement, which are capable of meeting design specifications required for building and highway construction, are provided. Such materials can thus significantly reduce construction costs.

Compressive strength of concrete and mortar containing fly ash

DOEpatents

Liskowitz, John W.; Wecharatana, Methi; Jaturapitakkul, Chai; Cerkanowicz, deceased, Anthony E.

1998-01-01

The present invention relates to concrete, mortar and other hardenable mixtures comprising cement and fly ash for use in construction. The invention includes a method for predicting the compressive strength of such a hardenable mixture, which is very important for planning a project. The invention also relates to hardenable mixtures comprising cement and fly ash which can achieve greater compressive strength than hardenable mixtures containing only concrete over the time period relevant for construction. In a specific embodiment, a formula is provided that accurately predicts compressive strength of concrete containing fly ash out to 180 days. In other specific examples, concrete and mortar containing about 15% to 25% fly ash as a replacement for cement, which are capable of meeting design specification required for building and highway construction, are provided. Such materials can thus significantly reduce construction costs.

Patch Test Negative Generalized Dermatitis.

PubMed

Spiker, Alison; Mowad, Christen

2016-01-01

Allergic contact dermatitis is a common condition in dermatology. Patch testing is the criterion standard for diagnosis. However, dermatitis is not always caused by an allergen, and patch testing does not identify a culprit in every patient. Generalized dermatitis, defined as eczematous dermatitis affecting greater than 3 body sites, is often encountered in dermatology practice, especially patch test referral centers. Management for patients with generalized dermatitis who are patch test negative is challenging. The purpose of this article is to outline an approach to this challenging scenario and summarize the paucity of existing literature on patch test negative generalized dermatitis.

63. BUILDING NO. 1301, ORDNANCE FACILITY (MORTAR POWDER BUILDING), INTERIOR, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

63. BUILDING NO. 1301, ORDNANCE FACILITY (MORTAR POWDER BUILDING), INTERIOR, LOOKING SOUTHEAST DOWN SCREENED WALKWAY ON NORTHWEST SIDE. - Picatinny Arsenal, State Route 15 near I-80, Dover, Morris County, NJ

Application of AMDS mortar as a treatment agent for arsenic in subsurface environment

NASA Astrophysics Data System (ADS)

Choi, J.; Lee, H.; Choi, U. K.; Yang, I. J.

2014-12-01

Among the treatment technologies available for As in soil and groundwater, adsorption or precipitation using acid mine drainage (AMD) sludge has become a promised technique because of high efficiency, inexpensiveness and simple to handling. The adsorbents were prepared by addition of Cement, Joomoonjin sand, fly ash, and Ca(OH)2 to air dry AMD sludge. In this work, the adsorption of As (III) and As (V) on AMDS mortar has been studied as a function of kinetic, pH, and initial arsenic concentration. Results of batch study showed that 75-90% of both As (III) and As (V) were removed at pH 7. Arsenic adsorption capacities were the highest at neutral pH condition and the adsorption equilibrium time reached in 7 days using AMDS mortar. Additionally, the adsorption kinetic process is expressed well by pseudo-second-order model. The adsorption capacities of AMDS mortar for As(III) and As(V) were found 19.04 and 30.75 mg g-1, respectively. The results of As (III) adsorption isotherms were fitted well to the Freundlich model. Moreover, As (V) adsorption isotherms were fitted well to the Langmuir model rather than Freundlich model. Based on experimental results in this study, we could conclude that AMDS mortar can be effectively used for arsenic removal agent from subsurface environment.

On the role of hydrophobic Si-based protective coatings in limiting mortar deterioration.

PubMed

Cappelletti, G; Fermo, P; Pino, F; Pargoletti, E; Pecchioni, E; Fratini, F; Ruffolo, S A; La Russa, M F

2015-11-01

In order to avoid both natural and artificial stone decay, mainly due to the interaction with atmospheric pollutants (both gases such as NOx and SO2 and particulate matter), polymeric materials have been widely studied as protective coatings enable to limit the penetration of fluids into the bulk material. In the current work, an air hardening calcic lime mortar (ALM) and a natural hydraulic lime mortar (HLM) were used as substrates, and commercially available Si-based resins (Alpha®SI30 and Silres®BS16) were adopted as protective agents to give hydrophobicity features to the artificial stones. Surface properties of coatings and their performance as hydrophobic agents were studied using different techniques such as contact angle measurements, capillary absorption test, mercury intrusion porosimetry, surface free energy, colorimetric measurements and water vapour permeability tests. Finally, some exposure tests to UV radiation and to real polluted atmospheric environments (a city centre and an urban background site) were carried out during a wintertime period (when the concentrations of the main atmospheric pollutants are higher) in order to study the durability of the coating systems applied. The effectiveness of the two commercial resins in reducing salt formation (sulphate and nitrate), induced by the interaction of the mortars with the atmospheric pollutants, was demonstrated in the case of the HLM mortar. Graphical Abstract ᅟ.

A Peridynamic Approach for Nanoscratch Simulation of the Cement Mortar

NASA Astrophysics Data System (ADS)

Zhao, Jingjing; Zhang, Qing; Lu, Guangda; Chen, Depeng

2018-03-01

The present study develops a peridynamic approach for simulating the nanoscratch procedure on the cement mortar interface. In this approach, the cement and sand are considered as discrete particles with certain mechanical properties on the nanoscale. Besides, the interaction force functions for different components in the interface are represented by combining the van der Waals force and the peridynamic force. The nanoscratch procedures with the indenter moving along certain direction either parallel or perpendicular to the interface are simulated in this paper. The simulation results show the damage evolution processes and the final damage distributions of the cement mortar under different scratching speed and depth of the indenter, indicating that the interface between cement and sand is a weak area.

VIEW OF MORTARED ROCK AND CONCRETE INLET TO COUCH LATERAL ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

VIEW OF MORTARED ROCK AND CONCRETE INLET TO COUCH LATERAL CANAL, UPSTREAM OF COLLINS ROAD. LOOKING NORTH/NORTHEAST - Tumalo Irrigation District, Tumalo Project, West of Deschutes River, Tumalo, Deschutes County, OR

Finite Element Analysis of Crack-Path Selection in a Brick and Mortar Structure

NASA Astrophysics Data System (ADS)

Sarrafi-Nour, Reza; Manoharan, Mohan; Johnson, Curtis A.

Many natural composite materials rely on organized architectures that span several length scales. The structures of natural shells such as nacre (mother-of-pearl) and conch are prominent examples of such organizations where the calcium carbonate platelets, the main constituent of natural shells, are held together in an organized fashion within an organic matrix. At one or multiple length scales, these organized arrangements often resemble a brick-and-mortar structure, with calcium carbonate platelets acting as bricks connected through the organic mortar phase.

Tamping Mortars with Stabilizing and Plasticizing Admixtures

NASA Astrophysics Data System (ADS)

Terlyha, Volodymir; Sobol, Khrystyna

2012-06-01

Boreholes cementing operations at the depth of several kilometers requires the best technology as well as the best materials. To produce the materials satisfying all the requirements concerning the tamping works is possible using the technology of dry building mixes (DBM) prepared at the factories by thorough mixing of accurately dosed components. Using of chemical admixtures allows improving some properties of these mixes. In this work the influence of mineral fillers and chemical admixtures on the properties of the fresh mixture and hardened tamping mortar was investigated. It is established that introduction of the admixture with complex action on the basis of stabilizer Walocel 15-01 and plasticizer Melflux 2651 allows obtaining the fresh mixture with high spreadability. At the same time the value of dehydration approaches to zero which favorably effects on stabilization of fresh mixture and not allows the sedimentation processes to take place. By the X-ray analysis, the positive influence of modification admixtures on the hydration processes in the tamping mortars by activating them was identified. In the result of this, the formation of hydrate phases is accelerated; these phases tightly mud the pore area of tamping stone increasing by this its strength.

9. DETAIL OF DECORATIVE MORTAR AND COBBLESTONE WORK ON TYPICAL ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

9. DETAIL OF DECORATIVE MORTAR AND COBBLESTONE WORK ON TYPICAL POST ON UPSTREAM PARAPET WALL OF UPPER EMBANKMENT. VIEW TO SOUTH. - Boise Project, Deer Flat Embankments, Lake Lowell, Nampa, Canyon County, ID

Application of biochar from food and wood waste as green admixture for cement mortar.

PubMed

Gupta, Souradeep; Kua, Harn Wei; Koh, Hui Jun

2018-04-01

Landfilling of food waste due to its low recycling rate is raising serious concerns because of associated soil and water contamination, and emission of methane and other greenhouse gases during the degradation process. This paper explores feasibility of using biochar derived from mixed food waste (FWBC), rice waste (RWBC) and wood waste (mixed wood saw dust, MWBC) as carbon sequestering additive in mortar. RWBC is prepared from boiled plain rice, while FWBC is prepared from combination of rice, meat, and vegetables in fixed proportion. Carbon content in FWBC, RWBC and MWBC were found to be 71%, 66% and 87% by weight respectively. Results show that addition of 1-2wt% of FWBC and RWBC in mortar results in similar mechanical strength as control mix (without biochar). 1wt% of FWBC led to 40% and 35% reduction in water penetration and sorptivity respectively, indicating higher impermeability of mortar. Biochar from mixed wood saw dust performed better in terms of mechanical and permeability properties. Increase in compressive strength and tensile strength by up to 20% was recorded, while depth of water penetration and sorptivity was reduced by about 60% and 38% respectively compared to control. Both FWBC and MWBC were found to act as reinforcement to mortar paste, which resulted in higher ductility than control at failure under flexure. This study suggests that biochar from food waste and mixed wood saw dust has the potential to be successfully deployed as additive in cement mortar, which would also promote waste recycling, and sequester high volume carbon in civil infrastructure. Copyright © 2017 Elsevier B.V. All rights reserved.

Influence of bicarbonate ions on the deterioration of mortar bars in sulfate solutions

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

Kunther, W., E-mail: Wolfgang.Kunther@empa.ch; Lothenbach, B.; Scrivener, K.

2013-02-15

This work investigates the influence of bicarbonate ions on the deterioration of cementitious material exposed to sulfate ions. Mortars based on a CEM I and on a CEM III/B cement were investigated. Experimental investigations were compared to thermodynamic modeling and phase characterization to understand the differences in deterioration. The presence of bicarbonate ions significantly reduced the expansion of the CEM I mortars. Thermodynamic modeling showed that at high concentrations of bicarbonate ettringite and gypsum become unstable. Microstructural characterization combined with information from thermodynamic modeling suggests that conditions of high supersaturation with respect to ettringite are unlikely in the samples exposedmore » in solutions containing bicarbonate. Consequently, expansive forces are not generated by the crystallization pressure of ettringite. There was little expansion of the CEM III/B sample even in the sodium sulfate solution. In the bicarbonate solution this mortar showed a highly leached zone at the surface in which calcite was observed.« less

The Effects of Different Fine Recycled Concrete Aggregates on the Properties of Mortar

PubMed Central

Fan, Cheng-Chih; Huang, Ran; Hwang, Howard; Chao, Sao-Jeng

2015-01-01

The practical use of recycled concrete aggregate produced by crushing concrete waste reduces the consumption of natural aggregate and the amount of concrete waste that ends up in landfills. This study investigated two methods used in the production of fine recycled concrete aggregate: (1) a method that produces fine as well as coarse aggregate, and (2) a method that produces only fine aggregate. Mortar specimens were tested using a variety of mix proportions to determine how the characteristics of fine recycled concrete aggregate affect the physical and mechanical properties of the resulting mortars. Our results demonstrate the superiority of mortar produced using aggregate produced using the second of the two methods. Nonetheless, far more energy is required to render concrete into fine aggregate than is required to produce coarse as well as fine aggregate simultaneously. Thus, the performance benefits of using only fine recycled concrete aggregate must be balanced against the increased impact on the environment.

Stability Analysis of a mortar cover ejected at various Mach numbers and angles of attack

NASA Astrophysics Data System (ADS)

Schwab, Jane; Carnasciali, Maria-Isabel; Andrejczyk, Joe; Kandis, Mike

2011-11-01

This study utilized CFD software to predict the aerodynamic coefficient of a wedge-shaped mortar cover which is ejected from a spacecraft upon deployment of its Parachute Recovery System (PRS). Concern over recontact or collision between the mortar cover and spacecraft served as the impetus for this study in which drag and moment coefficients were determined at Mach numbers from 0.3 to 1.6 at 30-degree increments. These CFD predictions were then used as inputs to a two-dimensional, multi-body, three-DoF trajectory model to calculate the relative motion of the mortar cover and spacecraft. Based upon those simulations, the study concluded a minimal/zero risk of collision with either the spacecraft or PRS. Sponsored by Pioneer Aerospace.

Oracle Applications Patch Administration Tool (PAT) Beta Version

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

2002-01-04

PAT is a Patch Administration Tool that provides analysis, tracking, and management of Oracle Application patches. This includes capabilities as outlined below: Patch Analysis & Management Tool Outline of capabilities: Administration Patch Data Maintenance -- track Oracle Application patches applied to what database instance & machine Patch Analysis capture text files (readme.txt and driver files) form comparison detail report comparison detail PL/SQL package comparison detail SQL scripts detail JSP module comparison detail Parse and load the current applptch.txt (10.7) or load patch data from Oracle Application database patch tables (11i) Display Analysis -- Compare patch to be applied with currentmore » Oracle Application installed Appl_top code versions Patch Detail Module comparison detail Analyze and display one Oracle Application module patch. Patch Management -- automatic queue and execution of patches Administration Parameter maintenance -- setting for directory structure of Oracle Application appl_top Validation data maintenance -- machine names and instances to patch Operation Patch Data Maintenance Schedule a patch (queue for later execution) Run a patch (queue for immediate execution) Review the patch logs Patch Management Reports« less

Monitoring uniform and localized corrosion in reinforced mortar using high-frequency guided longitudinal wages

NASA Astrophysics Data System (ADS)

Ervin, Benjamin L.; Reis, Henrique; Bernhard, Jennifer T.; Kuchma, Daniel A.

2008-03-01

High-frequency guided longitudinal waves have been used in a through-transmission arrangement to monitor reinforced mortar specimens undergoing both accelerated uniform and localized corrosion. High-frequency guided longitudinal waves were chosen because they have the fastest propagation velocity and lowest theoretical attenuation for the rebar/mortar system. This makes the modes easily discernible and gives them the ability to travel over long distances. The energy of the high-frequency longitudinal waves is located primarily in the center of the rebar, leading to less leakage into the surrounding mortar. The results indicate that the guided mechanical waves are sensitive to both forms of corrosion attack in the form of attenuation, with less sensitivity at higher frequencies. Also promising is the ability to discern uniform corrosion from localized corrosion in a through-transmission arrangement by examination of the frequency domain.

VIEW OF MORTARED ROCK FOOTING THAT ONCE SUPPORTED THE TWIN ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

VIEW OF MORTARED ROCK FOOTING THAT ONCE SUPPORTED THE TWIN FLUME'S OUTLET TO TUMALO FEED CANAL, WITH BRIDGE. LOOKING NORTHWEST - Tumalo Irrigation District, Tumalo Project, West of Deschutes River, Tumalo, Deschutes County, OR

8. VIEW TO NORTH OF INTERIOR OF STAMPMILLING LEVEL; MORTAR ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

8. VIEW TO NORTH OF INTERIOR OF STAMPMILLING LEVEL; MORTAR MOUNT FOR MILL IS IMMEDIATELY BELOW AND TO LEFT OF ORE-HOPPER (UPPER-CENTER). - Steamboat Stampmill, Brush Creek Canyon, Jacksonville, Jackson County, OR

Environmental Factors Affecting the Strength Characteristics of Modified Resin Mortars

NASA Astrophysics Data System (ADS)

Debska, Bernardeta; Licholai, Lech

2017-12-01

Resin concretes are composites in which a cement binder has been completely replaced by a synthetic resin. These materials are a good choice for the construction industry, especially in solutions requiring high strength, fast curing and durability. Polymer mortars are mainly used for the manufacture of industrial floors and prefabricated products such as tanks for aggressive chemicals, sewage pipes, or road and bridge drainage systems, as well as for the repair of damaged concrete structures. In all these applications, the strength and high chemical resistance of the applied material solutions are of key importance. It is particularly crucial to obtain information on how resin composites behave when exposed to aggressive agents over extended periods of time. It is also very important to use waste materials in order to obtain resin composites, as these activities are very well inscribed in the idea of environmental protection and meet the criteria of sustainable construction. The mortars described in this article meet the above principles. The article presents how the compressive strength of glycolyzate-modified epoxy mortars, obtained with the use of poly(ethylene terephthalate), changes after they are immersed in 10% sodium chloride solution. Sodium chloride solution was chosen due to the prospective applicability of the tested composites as repair materials used for e.g. bridges or overpasses that are exposed to this salt solution in wintertime. Changes in the properties of the composite samples were monitored over the period of one year. Statistical analysis of the test results was carried out with the use of Statistica programme. The module available in the mentioned program called Nonparametric Statistics - Comparing multiple independent samples made it possible to check the monitoring times during which the compressive strength values differed significantly. The obtained results allowed for determining the equation of the function approximating the course of

Characterization of Mechanical and Bactericidal Properties of Cement Mortars Containing Waste Glass Aggregate and Nanomaterials

PubMed Central

Sikora, Pawel; Augustyniak, Adrian; Cendrowski, Krzysztof; Horszczaruk, Elzbieta; Rucinska, Teresa; Nawrotek, Pawel; Mijowska, Ewa

2016-01-01

The recycling of waste glass is a major problem for municipalities worldwide. The problem concerns especially colored waste glass which, due to its low recycling rate as result of high level of impurity, has mostly been dumped into landfills. In recent years, a new use was found for it: instead of creating waste, it can be recycled as an additive in building materials. The aim of the study was to evaluate the possibility of manufacturing sustainable and self-cleaning cement mortars with use of commercially available nanomaterials and brown soda-lime waste glass. Mechanical and bactericidal properties of cement mortars containing brown soda-lime waste glass and commercially available nanomaterials (amorphous nanosilica and cement containing nanocrystalline titanium dioxide) were analyzed in terms of waste glass content and the effectiveness of nanomaterials. Quartz sand is replaced with brown waste glass at ratios of 25%, 50%, 75% and 100% by weight. Study has shown that waste glass can act as a successful replacement for sand (up to 100%) to produce cement mortars while nanosilica is incorporated. Additionally, a positive effect of waste glass aggregate for bactericidal properties of cement mortars was observed. PMID:28773823

Modeling Heat and Moisture Transport in Steam-Cured Mortar: Application to Aashto Type Vi Beams.

PubMed

Hernández-Bautista, E; Sandoval-Torres, S; de J Cano-Barrita, P F; Bentz, D P

2017-10-01

During steam curing of concrete, temperature and moisture gradients are developed, which are difficult to measure experimentally and can adversely affect the durability of concrete. In this research, a model of cement hydration coupled to moisture and heat transport was used to simulate the process of steam curing of mortars with water-to-cement ( w/c ) ratios by mass of 0.30 and 0.45, considering natural convection boundary conditions in mortar and concrete specimens of AASHTO Type VI beams. The primary variables of the model were moisture content, temperature, and degree of hydration. Moisture content profiles of mortar specimens (40 mm in diameter and 50 mm in height) were measured by magnetic resonance imaging. The degree of hydration was obtained by mass-based measurements of loss on ignition to 1000 °C. The results indicate that the model correctly simulates the moisture distribution and degree of hydration in mortar specimens. Application of the model to the steam curing of an AASHTO Type VI beam indicates temperature differences (between the surface and the center) higher than 20 °C during the cooling stage, and internal temperatures higher than 70 °C that may compromise the durability of the concrete.

Characterization of Mechanical and Bactericidal Properties of Cement Mortars Containing Waste Glass Aggregate and Nanomaterials.

PubMed

Sikora, Pawel; Augustyniak, Adrian; Cendrowski, Krzysztof; Horszczaruk, Elzbieta; Rucinska, Teresa; Nawrotek, Pawel; Mijowska, Ewa

2016-08-18

The recycling of waste glass is a major problem for municipalities worldwide. The problem concerns especially colored waste glass which, due to its low recycling rate as result of high level of impurity, has mostly been dumped into landfills. In recent years, a new use was found for it: instead of creating waste, it can be recycled as an additive in building materials. The aim of the study was to evaluate the possibility of manufacturing sustainable and self-cleaning cement mortars with use of commercially available nanomaterials and brown soda-lime waste glass. Mechanical and bactericidal properties of cement mortars containing brown soda-lime waste glass and commercially available nanomaterials (amorphous nanosilica and cement containing nanocrystalline titanium dioxide) were analyzed in terms of waste glass content and the effectiveness of nanomaterials. Quartz sand is replaced with brown waste glass at ratios of 25%, 50%, 75% and 100% by weight. Study has shown that waste glass can act as a successful replacement for sand (up to 100%) to produce cement mortars while nanosilica is incorporated. Additionally, a positive effect of waste glass aggregate for bactericidal properties of cement mortars was observed.

Adsorption of cesium on cement mortar from aqueous solutions.

PubMed

Volchek, Konstantin; Miah, Muhammed Yusuf; Kuang, Wenxing; DeMaleki, Zack; Tezel, F Handan

2011-10-30

The adsorption of cesium on cement mortar from aqueous solutions was studied in series of bench-scale tests. The effects of cesium concentration, temperature and contact time on process kinetics and equilibrium were evaluated. Experiments were carried out in a range of initial cesium concentrations from 0.0103 to 10.88 mg L(-1) and temperatures from 278 to 313 K using coupons of cement mortar immersed in the solutions. Non-radioactive cesium chloride was used as a surrogate of the radioactive (137)Cs. Solution samples were taken after set periods of time and analyzed by inductively coupled plasma mass spectroscopy. Depending on the initial cesium concentration, its equilibrium concentration in solution ranged from 0.0069 to 8.837 mg L(-1) while the respective surface concentration on coupons varied from 0.0395 to 22.34 μg cm(-2). Equilibrium test results correlated well with the Freundlich isotherm model for the entire test duration. Test results revealed that an increase in temperature resulted in an increase in adsorption rate and a decrease in equilibrium cesium surface concentration. Among several kinetic models considered, the pseudo-second order reaction model was found to be the best to describe the kinetic test results in the studied range of concentrations. The adsorption activation energy determined from Arrhenius equation was found to be approximately 55.9 kJ mol(-1) suggesting that chemisorption was the prevalent mechanism of interaction between cesium ions and cement mortar. Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.

Single-layer dual frequency patch antenna

NASA Astrophysics Data System (ADS)

Maci, S.; Gentili, G. B.; Avitabile, G.

1993-08-01

A configuration for a slotted patch antenna is introduced which allows two separate operating frequencies. Both of these frequencies are associated with a radiating mode almost identical to that of a standard patch. The two resonances are related to the patch width and the slot/patch length, respectively.

Patch-augmented rotator cuff repair: influence of the patch fixation technique on primary biomechanical stability.

PubMed

Jung, Christian; Spreiter, Gregor; Audigé, Laurent; Ferguson, Stephen J; Flury, Matthias

2016-05-01

There is an ongoing debate about the potential of patch augmentation to improve biomechanical stability and healing associated with rotator cuff repair. The biomechanical properties of three different patch-augmented rotator cuff repair techniques were assessed in vitro and compared with a standard repair. Dermal collagen patch augmentation may increase the primary stability and strength of the repaired tendon in vitro, depending on the technique used for patch application. Forty cadaveric sheep shoulders with dissected infraspinatus tendons were randomized into four groups (n = 10/group) for tendon repair using a knotless double-row suture anchor technique. A xenologous dermal extracellular matrix patch was used for augmentation in the three test groups using an "integrated", "cover", or "hybrid" technique. Tendons were preconditioned, cyclically loaded from 10 to 30 N at 1 Hz, and then loaded monotonically to failure. Biomechanical properties and the mode of failure were evaluated. Patch augmentation significantly increased the maximum load at failure by 61 % in the "cover" technique test group (225.8 N) and 51 % in the "hybrid" technique test group (211.4 N) compared with the non-augmented control group (140.2 N) (P ≤ 0.015). For the test group with "integrated" patch augmentation, the load at failure was 28 % lower (101.6 N) compared with the control group (P = 0.043). There was no significant difference in initial and linear stiffness among the four experimental groups. The most common mode of failure was tendon pullout. No anchor dislocation, patch disruption or knot breakage was observed. Additional patch augmentation with a collagen patch influences the biomechanical properties of a rotator cuff repair in a cadaveric sheep model. Primary repair stability can be significantly improved depending on the augmentation technique.

Do Schools Still Need Brick-and-Mortar Libraries?

ERIC Educational Resources Information Center

Johnson, Doug; Mastrion, Keith

2009-01-01

Do all schools need brick-and-mortar libraries? In this article, Johnson and Mastrion share their contradictory thoughts to the question. Johnson says some schools don't need library facilities or programs or librarians. These schools' teachers and administrators: (1) feel no need for a collaborative learning space; (2) feel the ability to process…

The use of Papuan iron sand and river sand for fine aggregate in mortar for nuclear radiation shield application

NASA Astrophysics Data System (ADS)

Dahlan, K.; Haryati, E.; Aninam, Y. S.

2018-03-01

This study explores the effect of fine aggregate on mortar properties and its application as a nuclear shield. This study was based on a hypothesis that the types of aggregate applied as radiation shield determined the level of its effectiveness on preventing nuclear radiation. There are two types and sources of fine aggregate that was used as main ingredients for mortar production in this research, namely iron sand and river sand. Both types of sand were derived from the respective regions of Sarmi and Jayapura, Papua. The results showed that the mortar materials that were produced with the iron sand provided better results in dispelling radiation than that of river sand. The compressive strength of fine aggregate from the iron sand was 21.62 MPa, while the compressive strength of the river sand was 16.8 MPa. Measuring the attenuation coefficient of material, we found that the largest aggregated value of mortar with fine iron sand reached 0.0863 / cm. On the other hand, the smallest HVT (Half Value Thickness) was obtained from the iron sand mortar, at 8.03 cm.

Patch Finder Plus (PFplus): a web server for extracting and displaying positive electrostatic patches on protein surfaces.

PubMed

Shazman, Shula; Celniker, Gershon; Haber, Omer; Glaser, Fabian; Mandel-Gutfreund, Yael

2007-07-01

Positively charged electrostatic patches on protein surfaces are usually indicative of nucleic acid binding interfaces. Interestingly, many proteins which are not involved in nucleic acid binding possess large positive patches on their surface as well. In some cases, the positive patches on the protein are related to other functional properties of the protein family. PatchFinderPlus (PFplus) http://pfp.technion.ac.il is a web-based tool for extracting and displaying continuous electrostatic positive patches on protein surfaces. The input required for PFplus is either a four letter PDB code or a protein coordinate file in PDB format, provided by the user. PFplus computes the continuum electrostatics potential and extracts the largest positive patch for each protein chain in the PDB file. The server provides an output file in PDB format including a list of the patch residues. In addition, the largest positive patch is displayed on the server by a graphical viewer (Jmol), using a simple color coding.

Patch Finder Plus (PFplus): A web server for extracting and displaying positive electrostatic patches on protein surfaces

PubMed Central

Shazman, Shula; Celniker, Gershon; Haber, Omer; Glaser, Fabian; Mandel-Gutfreund, Yael

2007-01-01

Positively charged electrostatic patches on protein surfaces are usually indicative of nucleic acid binding interfaces. Interestingly, many proteins which are not involved in nucleic acid binding possess large positive patches on their surface as well. In some cases, the positive patches on the protein are related to other functional properties of the protein family. PatchFinderPlus (PFplus) http://pfp.technion.ac.il is a web-based tool for extracting and displaying continuous electrostatic positive patches on protein surfaces. The input required for PFplus is either a four letter PDB code or a protein coordinate file in PDB format, provided by the user. PFplus computes the continuum electrostatics potential and extracts the largest positive patch for each protein chain in the PDB file. The server provides an output file in PDB format including a list of the patch residues. In addition, the largest positive patch is displayed on the server by a graphical viewer (Jmol), using a simple color coding. PMID:17537808

Investigating the Influence of Waste Basalt Powder on Selected Properties of Cement Paste and Mortar

NASA Astrophysics Data System (ADS)

Dobiszewska, Magdalena; Beycioğlu, Ahmet

2017-10-01

Concrete is the most widely used man-made construction material in civil engineering applications. The consumption of cement and thus concrete, increases day by day along with the growth of urbanization and industrialization and due to new developments in construction technologies, population growing, increasing of living standard. Concrete production consumes much energy and large amounts of natural resources. It causes environmental, energy and economic losses. The most important material in concrete production is cement. Cement industry contributes to production of about 7% of all CO2 generated in the world. Every ton of cement production releases nearly one ton of CO2 to atmosphere. Thus the concrete and cement industry changes the environment appearance and influences it very much. Therefore, it has become very important for construction industry to focus on minimizing the environmental impact, reducing energy consumption and limiting CO2 emission. The need to meet these challenges has spurred an interest in the development of a blended Portland cement in which the amount of clinker is reduced and partially replaced with mineral additives - supplementary cementitious materials (SCMs). Many researchers have studied the possibility of using another mineral powder in mortar and concrete production. The addition of marble dust, basalt powder, granite or limestone powder positively affects some properties of cement mortar and concrete. This paper presents an experimental study on the properties of cement paste and mortar containing basalt powder. The basalt powder is a waste emerged from the preparation of aggregate used in asphalt mixture production. Previous studies have shown that analysed waste used as a fine aggregate replacement, has a beneficial effect on some properties of mortar and concrete, i.e. compressive strength, flexural strength and freeze resistance also. The present study shows the results of the research concerning the modification of cement

Mechanical properties of the rust layer induced by impressed current method in reinforced mortar

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

Care, S.; Nguyen, Q.T.; L'Hostis, V.

This paper describes the mechanical effects of rust layer formed in reinforced mortar through accelerated tests of corrosion. The morphological and physico-chemical properties (composition, structures) of the corrosion system were characterized at different stages by using optical microscope and scanning electron microscope coupled with energy dispersive spectroscopy. The corrosion pattern was mainly characterized by a rust layer confined at the interface between the steel and the mortar. Expansion coefficient of rust products was determined from the rust thickness and the Faraday's law. Furthermore, in order to understand the mechanical effects of corrosion on the damage of mortar, displacement field measurementsmore » were obtained by using digital image correlation. An analytical model (hollow cylinder subjected to inner and outer pressures) was used with a set of experimental data to deduce the time of cracking and the order of magnitude of the mechanical properties of the rust layer.« less

7. Detail, beaded mortar joint, stepped wingwall coping at the ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

7. Detail, beaded mortar joint, stepped wingwall coping at the east portal of Tunnel 18, 135mm lens with electronic flash fill. - Southern Pacific Railroad Natron Cutoff, Tunnel No. 18, Milepost 410, Dorris, Siskiyou County, CA

Industrializing electrophysiology: HT automated patch clamp on SyncroPatch® 96 using instant frozen cells.

PubMed

Polonchuk, Liudmila

2014-01-01

Patch-clamping is a powerful technique for investigating the ion channel function and regulation. However, its low throughput hampered profiling of large compound series in early drug development. Fortunately, automation has revolutionized the area of experimental electrophysiology over the past decade. Whereas the first automated patch-clamp instruments using the planar patch-clamp technology demonstrated rather a moderate throughput, few second-generation automated platforms recently launched by various companies have significantly increased ability to form a high number of high-resistance seals. Among them is SyncroPatch(®) 96 (Nanion Technologies GmbH, Munich, Germany), a fully automated giga-seal patch-clamp system with the highest throughput on the market. By recording from up to 96 cells simultaneously, the SyncroPatch(®) 96 allows to substantially increase throughput without compromising data quality. This chapter describes features of the innovative automated electrophysiology system and protocols used for a successful transfer of the established hERG assay to this high-throughput automated platform.

Transdermal patches: history, development and pharmacology

PubMed Central

Pastore, Michael N; Kalia, Yogeshvar N; Horstmann, Michael; Roberts, Michael S

2015-01-01

Transdermal patches are now widely used as cosmetic, topical and transdermal delivery systems. These patches represent a key outcome from the growth in skin science, technology and expertise developed through trial and error, clinical observation and evidence-based studies that date back to the first existing human records. This review begins with the earliest topical therapies and traces topical delivery to the present-day transdermal patches, describing along the way the initial trials, devices and drug delivery systems that underpin current transdermal patches and their actives. This is followed by consideration of the evolution in the various patch designs and their limitations as well as requirements for actives to be used for transdermal delivery. The properties of and issues associated with the use of currently marketed products, such as variability, safety and regulatory aspects, are then described. The review concludes by examining future prospects for transdermal patches and drug delivery systems, such as the combination of active delivery systems with patches, minimally invasive microneedle patches and cutaneous solutions, including metered-dose systems. PMID:25560046

Transdermal patches: history, development and pharmacology.

PubMed

Pastore, Michael N; Kalia, Yogeshvar N; Horstmann, Michael; Roberts, Michael S

2015-05-01

Transdermal patches are now widely used as cosmetic, topical and transdermal delivery systems. These patches represent a key outcome from the growth in skin science, technology and expertise developed through trial and error, clinical observation and evidence-based studies that date back to the first existing human records. This review begins with the earliest topical therapies and traces topical delivery to the present-day transdermal patches, describing along the way the initial trials, devices and drug delivery systems that underpin current transdermal patches and their actives. This is followed by consideration of the evolution in the various patch designs and their limitations as well as requirements for actives to be used for transdermal delivery. The properties of and issues associated with the use of currently marketed products, such as variability, safety and regulatory aspects, are then described. The review concludes by examining future prospects for transdermal patches and drug delivery systems, such as the combination of active delivery systems with patches, minimally invasive microneedle patches and cutaneous solutions, including metered-dose systems. © 2015 The British Pharmacological Society.

Large-scale binding ligand prediction by improved patch-based method Patch-Surfer2.0

PubMed Central

Zhu, Xiaolei; Xiong, Yi; Kihara, Daisuke

2015-01-01

Motivation: Ligand binding is a key aspect of the function of many proteins. Thus, binding ligand prediction provides important insight in understanding the biological function of proteins. Binding ligand prediction is also useful for drug design and examining potential drug side effects. Results: We present a computational method named Patch-Surfer2.0, which predicts binding ligands for a protein pocket. By representing and comparing pockets at the level of small local surface patches that characterize physicochemical properties of the local regions, the method can identify binding pockets of the same ligand even if they do not share globally similar shapes. Properties of local patches are represented by an efficient mathematical representation, 3D Zernike Descriptor. Patch-Surfer2.0 has significant technical improvements over our previous prototype, which includes a new feature that captures approximate patch position with a geodesic distance histogram. Moreover, we constructed a large comprehensive database of ligand binding pockets that will be searched against by a query. The benchmark shows better performance of Patch-Surfer2.0 over existing methods. Availability and implementation: http://kiharalab.org/patchsurfer2.0/ Contact: dkihara@purdue.edu Supplementary information: Supplementary data are available at Bioinformatics online. PMID:25359888

Pozzolanic Activity Assessment of LUSI (LUmpur SIdoarjo) Mud in Semi High Volume Pozzolanic Mortar

PubMed Central

Hardjito, Djwantoro; Antoni; Wibowo, Gunadi M.; Christianto, Danny

2012-01-01

LUSI mud obtained from the mud volcano in Sidoarjo, Indonesia, is a viable aluminosilicate material to be utilized as pozzolanic material. LUSI is an abbreviation of the local name of the mud, i.e., Lumpur Sidoarjo, meaning Sidoarjo mud. This paper reports the results of an investigation to assess the pozzolanic activity of LUSI mud, especially in semi high volume pozzolanic mortar. In this case, the amount of mud incorporated is between 30% to 40% of total cementitious material, by mass. The content of SiO2 in the mud is about 30%, whilst the total content of SiO2, Fe2O3 and Al2O3 is more than 70%. Particle size and degree of partial cement replacement by treated LUSI mud affect the compressive strength, the strength activity index (SAI), the rate of pozzolanic activity development, and the workability of mortar incorporating LUSI mud. Manufacturing semi high volume LUSI mud mortar, up to at least 40% cement replacement, is a possibility, especially with a smaller particle size of LUSI mud, less than 63 μm. The use of a larger percentage of cement replacement by LUSI mud does not show any adverse effect on the water demand, as the flow of the fresh mortar increased with the increase of percentage of LUSI mud usage.

NEUTRON RADIOGRAPHY MEASUREMENT OF SALT SOLUTION ABSORPTION IN MORTAR

PubMed Central

Lucero, Catherine L.; Spragg, Robert P.; Bentz, Dale P.; Hussey, Daniel S.; Jacobson, David L.; Weiss, W. Jason

2017-01-01

Some concrete pavements in the US have recently exhibited premature joint deterioration. It is hypothesized that one component of this damage can be attributed to a reaction that occurs when salt-laden water is absorbed in the concrete and reacts with the matrix. This study examines the absorption of CaCl2 solution in mortar via neutron imaging. Mortar specimens were prepared with water to cement ratios, (w/c), of 0.36, 0.42 and 0.50 by mass and exposed to chloride solutions with concentrations ranging from 0 % to 29.8 % by mass. Depth of fluid penetration and moisture content along the specimen length were determined for 96 h after exposure. At high salt concentration (29.8 %), the sorption rate decreased by over 80 % in all samples. Along with changes in surface tension and viscosity, CaCl2 reacts with the cement paste to produce products (Friedel’s salt, Kuzel’s salt, or calcium oxychloride) that block pores and reduce absorption. PMID:28626299

NEUTRON RADIOGRAPHY MEASUREMENT OF SALT SOLUTION ABSORPTION IN MORTAR.

PubMed

Lucero, Catherine L; Spragg, Robert P; Bentz, Dale P; Hussey, Daniel S; Jacobson, David L; Weiss, W Jason

2017-01-01

Some concrete pavements in the US have recently exhibited premature joint deterioration. It is hypothesized that one component of this damage can be attributed to a reaction that occurs when salt-laden water is absorbed in the concrete and reacts with the matrix. This study examines the absorption of CaCl 2 solution in mortar via neutron imaging. Mortar specimens were prepared with water to cement ratios, ( w/c ), of 0.36, 0.42 and 0.50 by mass and exposed to chloride solutions with concentrations ranging from 0 % to 29.8 % by mass. Depth of fluid penetration and moisture content along the specimen length were determined for 96 h after exposure. At high salt concentration (29.8 %), the sorption rate decreased by over 80 % in all samples. Along with changes in surface tension and viscosity, CaCl 2 reacts with the cement paste to produce products (Friedel's salt, Kuzel's salt, or calcium oxychloride) that block pores and reduce absorption.

Study on the Carbonation Behavior of Cement Mortar by Electrochemical Impedance Spectroscopy

PubMed Central

Dong, Biqin; Qiu, Qiwen; Xiang, Jiaqi; Huang, Canjie; Xing, Feng; Han, Ningxu

2014-01-01

A new electrochemical model has been carefully established to explain the carbonation behavior of cement mortar, and the model has been validated by the experimental results. In fact, it is shown by this study that the electrochemical impedance behavior of mortars varies in the process of carbonation. With the cement/sand ratio reduced, the carbonation rate reveals more remarkable. The carbonation process can be quantitatively accessed by a parameter, which can be obtained by means of the electrochemical impedance spectroscopy (EIS)-based electrochemical model. It has been found that the parameter is a function of carbonation depth and of carbonation time. Thereby, prediction of carbonation depth can be achieved. PMID:28788452

Study on the Carbonation Behavior of Cement Mortar by Electrochemical Impedance Spectroscopy.

PubMed

Dong, Biqin; Qiu, Qiwen; Xiang, Jiaqi; Huang, Canjie; Xing, Feng; Han, Ningxu

2014-01-03

A new electrochemical model has been carefully established to explain the carbonation behavior of cement mortar, and the model has been validated by the experimental results. In fact, it is shown by this study that the electrochemical impedance behavior of mortars varies in the process of carbonation. With the cement/sand ratio reduced, the carbonation rate reveals more remarkable. The carbonation process can be quantitatively accessed by a parameter, which can be obtained by means of the electrochemical impedance spectroscopy (EIS)-based electrochemical model. It has been found that the parameter is a function of carbonation depth and of carbonation time. Thereby, prediction of carbonation depth can be achieved.

A chemical rationalization of the processing and application of the mortar coatings: Structural, thermodynamic, and fluorescence properties

NASA Astrophysics Data System (ADS)

Lima, Nathan B.; Rogerio, V. A.; Belarmino, Marcia K. D. L.; Silva, Anderson I. S.; Ioras, Renan U. F.; Oliveira, Romilde A.; Lima, Nathalia B. D.

2018-07-01

A chemical rationalization of the processing and application of the roughcast and plaster mortar coatings was advanced. The results revealed that the structural and thermodynamic nature of the hydrogen-bonded complexes between the inorganic precursors and water molecules are associated with the physical properties of both coatings. In this sense, the workability and curing time of the roughcast and the plaster mortars studied, seemingly, are related to the nature of the water solvation in the main components of these materials: calcium hydroxide and silicon dioxide. In addition, PM7 and PM7/COSMO results indicate that the enthalpy of solvation of water by hydrogen bonds in calcium hydroxide is stronger when compared with silicon dioxide systems. Therefore, the presence of free hydrated lime (calcium hydroxide) in the precursor mixture of plaster mortar leads to the large workability and elapsed curing time of this material. On the other hand, the absence of free hydrated lime in the precursor mixture of the roughcast mortar leads to its poor workability and faster elapsed curing time. Further, fluorescence microscopy experiments revealed that the inorganic compounds present in the cement precursor were transformed into different materials, that exhibit red and blue fluorescence. Finally, mechanical tests showed a tensile strength average 0.67 MPa for the plaster mortar material, whereas for the roughcast material is 0.53 MPa.

18. Detail, typical quarryfaced ashlar blocks, convextooled mortar joints, on ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

18. Detail, typical quarry-faced ashlar blocks, convex-tooled mortar joints, on pillars in former porte porte cochere area, view to southeast, 135mm lens. - Southern Pacific Depot, 559 El Camino Real, San Carlos, San Mateo County, CA

9. VIEW OF SOUTHERN ROCKFACED DRESSED AND MORTARED STONE ABUTMENT, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

9. VIEW OF SOUTHERN ROCKFACED DRESSED AND MORTARED STONE ABUTMENT, SHOWING STEEL CROSSBEAMS, TORSIONAL DIAGONAL STRUTS, AND WOODEN STRINGERS. FACING SOUTHWEST. - Coverts Crossing Bridge, Spanning Mahoning River along Township Route 372 (Covert Road), New Castle, Lawrence County, PA

DyninstAPI Patches

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

LeGendre, M.

2012-04-01

We are seeking a code review of patches against DyninstAPI 8.0. DyninstAPI is an open source binary instrumentation library from the University of Wisconsin and University of Maryland. Our patches port DyninstAPI to the BlueGene/P and BlueGene/Q systems, as well as fix DyninstAPI bugs and implement minor new features in DyninstAPI.

Dynamic tensile fracture of mortar at ultra-high strain-rates

NASA Astrophysics Data System (ADS)

Erzar, B.; Buzaud, E.; Chanal, P.-Y.

2013-12-01

During the lifetime of a structure, concrete and mortar may be exposed to highly dynamic loadings, such as impact or explosion. The dynamic fracture at high loading rates needs to be well understood to allow an accurate modeling of this kind of event. In this work, a pulsed-power generator has been employed to conduct spalling tests on mortar samples at strain-rates ranging from 2 × 104 to 4 × 104 s-1. The ramp loading allowed identifying the strain-rate anytime during the test. A power law has been proposed to fit properly the rate-sensitivity of tensile strength of this cementitious material over a wide range of strain-rate. Moreover, a specimen has been recovered damaged but unbroken. Micro-computed tomography has been employed to study the characteristics of the damage pattern provoked by the dynamic tensile loading.

Patch size has no effect on insect visitation rate per unit area in garden-scale flower patches

NASA Astrophysics Data System (ADS)

Garbuzov, Mihail; Madsen, Andy; Ratnieks, Francis L. W.

2015-01-01

Previous studies investigating the effect of flower patch size on insect flower visitation rate have compared relatively large patches (10-1000s m2) and have generally found a negative relationship per unit area or per flower. Here, we investigate the effects of patch size on insect visitation in patches of smaller area (range c. 0.1-3.1 m2), which are of particular relevance to ornamental flower beds in parks and gardens. We studied two common garden plant species in full bloom with 6 patch sizes each: borage (Borago officinalis) and lavender (Lavandula × intermedia 'Grosso'). We quantified flower visitation by insects by making repeated counts of the insects foraging at each patch. On borage, all insects were honey bees (Apis mellifera, n = 5506 counts). On lavender, insects (n = 737 counts) were bumble bees (Bombus spp., 76.9%), flies (Diptera, 22.4%), and butterflies (Lepidoptera, 0.7%). On both plant species we found positive linear effects of patch size on insect numbers. However, there was no effect of patch size on the number of insects per unit area or per flower and, on lavender, for all insects combined or only bumble bees. The results show that it is possible to make unbiased comparisons of the attractiveness of plant species or varieties to flower-visiting insects using patches of different size within the small scale range studied and make possible projects aimed at comparing ornamental plant varieties using existing garden flower patches of variable area.

8. SIDE VIEW OF NORTHEASTERN ROCKFACED DRESSED AND MORTARED STONE ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

8. SIDE VIEW OF NORTHEASTERN ROCKFACED DRESSED AND MORTARED STONE BRIDGE ABUTMENT (LEFT) AND DRESSED, DRY-LAID RETAINING WALL (RIGHT). FACING WEST. - Coverts Crossing Bridge, Spanning Mahoning River along Township Route 372 (Covert Road), New Castle, Lawrence County, PA

10. SIDE VIEW OF SOUTHEASTERN ROCKFACED DRESSED AND MORTARED STONE ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

10. SIDE VIEW OF SOUTHEASTERN ROCKFACED DRESSED AND MORTARED STONE BRIDGE ABUTMENT (RIGHT) AND DRESSED, DRY-LAID RETAINING WALL (LEFT). FACING NORTHWEST. - Coverts Crossing Bridge, Spanning Mahoning River along Township Route 372 (Covert Road), New Castle, Lawrence County, PA

Study of ancient mortars from the Roman Villa of Pollio Felice in Sorrento (Naples)

NASA Astrophysics Data System (ADS)

Benedetti, D.; Valetti, S.; Bontempi, E.; Piccioli, C.; Depero, L. E.

The study of ancient mortars is an important aspect of building conservation: the choice of the materials has varied according to historical period, regional habits, and their specific function in the structure. Ancient mortars are composites, comprising hydraulic or aerial binding materials, and aggregates, passive or active, which may react with binding material. Moreover, they were modified during setting, hardening, and aging, according to processes not yet well known. In this paper, we present a study of ancient mortars from the Villa of Pollio Felice of Sorrento (Naples). The analysis has been performed by conventional techniques (grain-size distribution, lime-percentage analysis, optical and electron microscopy, and X-ray diffraction) and by means of a laboratory X-ray microdiffractometer equipped with an image plate detector. This system, applied for the first time to archaeological studies, can reach a spatial resolution of a few tenths of microns and it allows us to obtain separate phase identification of binder and filler particles.

Use of polypropylene fibers coated with nano-silica particles into a cementitious mortar

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

Coppola, B., E-mail: bcoppola@unisa.it; Di Maio, L.; Scarfato, P.

Fiber reinforced cementitious composite (FRCC) materials have been widely used during last decades in order to overcome some of traditional cementitious materials issues: brittle behaviour, fire resistance, cover spalling, impact strength. For composite materials, fiber/matrix bond plays an important role because by increasing fiber/matrix interactions is possible to increase the behaviour of the entire material. In this study, in order to improve fiber to matrix adhesion, two chemical treatments of polypropylene fibers were investigated: alkaline hydrolysis and nano-silica sol-gel particles deposition. Treatmtents effect on fibers morphology and mechanical properties was investigated by scanning electron microscopy (SEM) and tensile tests. SEMmore » investigations report the presence of spherical nano-silica particles on fiber surface, in the case of sol-gel process, while alkaline hydrolysis leads to an increase of fibers roughness. Both treatments have negligible influence on fibers mechanical properties confirming the possibility of their use in a cementitious mortar. Pullout tests were carried out considering three embedded length of fibers in mortar samples (10, 20 and 30 mm, respectively) showing an increase of pullout energy for treated fibers. The influence on fiber reinforced mortar mechanical properties was investigated by three-point flexural tests on prismatic specimens considering two fibers length (15 and 30 mm) and two fibers volume fractions (0.50 and 1.00 %). A general increase of flexural strength over the reference mix was achieved and an overall better behaviour is recognizable for mortars containing treated fibers.« less

Comparison of Glass Powder and Fly Ash Effect on the Fresh Properties of Self-Compacting Mortars

NASA Astrophysics Data System (ADS)

Öznur Öz, Hatice; Erhan Yücel, Hasan; Güneş, Muhammet

2017-10-01

This study is aimed to determine effects of glass powder on fresh properties of self-compacting mortars. Self-compacting mortars incorporating glass powder (SCMGPs) were designed with a water/binder ratio of 0.40 and a total binder content of 550 kg/m3. At first, the control mixture was produced with 20% fly ash and % 80 cement of the total binder content without using the glass powder. Then, glass powder was used in the proportions 5%, 10%, 15% and 20% instead of fly ash in the mortars. Mini-slump flow and mini-v funnel tests experimentally investigated on SCMGPs to compare the effect of fly ash and glass powder. With increasing the amount of glass powder used in SCMGPs increased the amount of superplasticizer used to obtain the desired mini-slump flow diameter. So, the use of glass powder reduced the flow ability of SCMGPs in comparison to fly ash. Additionally, the compressive strength and flexural strength of the mortar mixtures were determined at the 28th day. The test results indicated that the mechanical characteristics of SCMGPs improved when the fly ash was replaced with glass powder in SCMGPs.

Large-scale binding ligand prediction by improved patch-based method Patch-Surfer2.0.

PubMed

Zhu, Xiaolei; Xiong, Yi; Kihara, Daisuke

2015-03-01

Ligand binding is a key aspect of the function of many proteins. Thus, binding ligand prediction provides important insight in understanding the biological function of proteins. Binding ligand prediction is also useful for drug design and examining potential drug side effects. We present a computational method named Patch-Surfer2.0, which predicts binding ligands for a protein pocket. By representing and comparing pockets at the level of small local surface patches that characterize physicochemical properties of the local regions, the method can identify binding pockets of the same ligand even if they do not share globally similar shapes. Properties of local patches are represented by an efficient mathematical representation, 3D Zernike Descriptor. Patch-Surfer2.0 has significant technical improvements over our previous prototype, which includes a new feature that captures approximate patch position with a geodesic distance histogram. Moreover, we constructed a large comprehensive database of ligand binding pockets that will be searched against by a query. The benchmark shows better performance of Patch-Surfer2.0 over existing methods. http://kiharalab.org/patchsurfer2.0/ CONTACT: dkihara@purdue.edu Supplementary data are available at Bioinformatics online. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Application of antifungal CFB to increase the durability of cement mortar.

PubMed

Park, Jong-Myong; Park, Sung-Jin; Kim, Wha-Jung; Ghim, Sa-Youl

2012-07-01

Antifungal cement mortar or microbiological calcium carbonate precipitation on cement surface has been investigated as functional concrete research. However, these research concepts have never been fused with each other. In this study, we introduced the antifungal calciteforming bacteria (CFB) Bacillus aryabhattai KNUC205, isolated from an urban tunnel (Daegu, South Korea). The major fungal deteriogens in urban tunnel, Cladosporium sphaerospermum KNUC253, was used as a sensitive fungal strain. B. aryabhattai KNUC205 showed CaCO3 precipitation on B4 medium. Cracked cement mortar pastes were made and neutralized by modified methods. Subsequently, the mixture of B. aryabhattai KNUC205, conidiospore of C. sphaerospermum KNUC253, and B4 agar was applied to cement cracks and incubated at 18 degrees C for 16 days. B. aryabhattai KNUC205 showed fungal growth inhibition against C. sphaerospermum. Furthermore, B. aryabhattai KNUC205 showed crack remediation ability and water permeability reduction of cement mortar pastes. Taken together, these results suggest that the CaCO3 precipitation and antifungal properties of B. aryabhattai KNUC205 could be used as an effective sealing or coating material that can also prevent deteriorative fungal growth. This study is the first application and evaluation research that incorporates calcite formation with antifungal capabilities of microorganisms for an environment-friendly and more effective protection of cement materials. In this research, the conception of microbial construction materials was expanded.

Aortic valve repair with autologous pericardial patch.

PubMed

Lausberg, Henning F; Aicher, Diana; Langer, Frank; Schäfers, Hans-Joachim

2006-08-01

Isolated aortic valve repair (AVR) has been gaining increasing interest in recent times. Results of isolated aortic valve repair have been reported to be variable. Various techniques have been utilized. We analyzed our experience with isolated valve repair using autologous pericardial patch plasty and compared the results to an age-matched collective with aortic valve repair without the use of additional material. Between January 1997 and June 2005, pericardial patch plasty of the aortic valve was performed in 42 patients (PATCH). During the same period, 42 patients after AVR without the use of additional material were age matched (NO-PATCH). Mean age in both groups was 52 years with a majority of male patients (PATCH ratio, 3.7:1; NO-PATCH ratio, 5:1). Valve anatomy was similar in both groups. All patients were followed by echocardiography for a cumulative follow-up of 2341 patient months (mean 28+/-23 months). No patient died in the hospital in neither group. The average systolic gradient was 5.9+/-2.2 mmHg in PATCH and 4.8+/-2.1 mmHg in NO-PATCH; p=0.17). Freedom from aortic regurgitation > or = II degrees was 87.8% in PATCH and 95.0% in NO-PATCH after 5 years (p=0.21). Freedom from reoperation was 97.6% in PATCH and 97.4% in NO-PATCH (p=0.96). Aortic regurgitation can be treated effectively by aortic valve repair using pericardial patch plasty. The functional results are satisfactory. With the application of this technique also more complex pathologies of the aortic valve can be addressed adequately thus extending the concept of valve preservation in patients with aortic regurgitation.

Keratin film ablation for the fabrication of brick and mortar skin structure using femtosecond laser pulses

NASA Astrophysics Data System (ADS)

Haq, Bibi Safia; Khan, Hidayat Ullah; Dou, Yuehua; Alam, Khan; Attaullah, Shehnaz; Zari, Islam

2015-09-01

The patterning of thin keratin films has been explored to manufacture model skin surfaces based on the "bricks and mortar" view of the relationship between keratin and lipids. It has been demonstrated that laser light is capable of preparing keratin-based "bricks and mortar" wall structure as in epidermis, the outermost layer of the human skin. "Bricks and mortar" pattern in keratin films has been fabricated using an ArF excimer laser (193 nm wavelength) and femtosecond laser (800 and 400 nm wavelength). Due to the very low ablation threshold of keratin, femtosecond laser systems are practical for laser processing of proteins. These model skin structures are fabricated for the first time that will help to produce potentially effective moisturizing products for the protection of skin from dryness, diseases and wrinkles.

Analysis of Bending Strength of Resin Mortars That Are at Risk of Long-Term Exposure to Environmental Corrosives

NASA Astrophysics Data System (ADS)

Debska, Bernardeta; Licholai, Lech

2017-12-01

The results of the article are part of an extensive research on new building materials including cement-free polymer composites where the binder is epoxy resin modified with glycolyzates obtained from poly (ethylene terephthalate) waste (PET). The investigation conducted con-firmed that there is a possibility of using waste materials in the production of mortar. Since they have always been an environmental problem, their utilization will help to apply the principles of sustainable development in the processes of obtaining new materials. The article discusses the results of a study of flexural strength of polymer mortars. Mortar specimens modified with propylene glycol and PET waste based glycolyzate were exposed to a 10% NaCl solution and their strength parameters were then examined after one month, six months and twelve months of immersion in this aggressive medium. The same characteristics were also determined for specimens that were not exposed to the NaCl solution. The results were presented as the trend function. The sections of the curve corresponding to the particular periods of exposure in aggressive medium vary in shape. Due to this, an attempt was made to adjust the spline function to the experimental data. The composites obtained show a deterioration in their strength properties which grows with the extension of their exposure to a corrosive medium. However, the chemical corrosion resistance of the mortars under investigation can be considered very good as it is still much higher than that of conventional cement mortars. Even after a year exposure to a corrosive substance, the mortars obtained still show high mean flexural strength values which equal about 30 MPa.

Material Performance and Animal Clinical Studies on Performance-Optimized Hwangtoh Mixed Mortar and Concrete to Evaluate Their Mechanical Properties and Health Benefits.

PubMed

Koo, Bon-Min; Kim, Jang-Ho Jay; Kim, Tae-Kyun; Kim, Byung-Yun

2015-09-17

In this study, the amount of cement used in a concrete mix is minimized to reduce the toxic effects on users by adjusting the concrete mixture contents. The reduction of cement is achieved by using various admixtures (ground granulated blast-furnace slag, flyash, ordinary Portland cement, and activated Hwangtoh powder). To apply the mix to construction, material property tests such as compressive strength, slump, and pH are performed. Preliminary experimental results showed that the Hwangtoh concrete could be used as a healthy construction material. Also, the health issues and effects of Hwangtoh mortar are quantitatively evaluated through an animal clinical test. Mice are placed in Hwangtoh mortar and cement mortar cages to record their activity. For the test, five cages are made with Hwangtoh and ordinary Portland cement mortar floors, using Hwangtoh powder replacement ratios of 20%, 40%, 60%, and 80% of the normal cement mortar mixing ratio, and two cages are made with Hwangtoh mortar living quarters. The activity parameter measurements included weight, food intake, water intake, residential space selection, breeding activity, and aggression. The study results can be used to evaluate the benefits of using Hwangtoh as a cement replacing admixture for lifestyle, health and sustainability.

Edge of polar cap patches

NASA Astrophysics Data System (ADS)

Hosokawa, K.; Taguchi, S.; Ogawa, Y.

2016-04-01

On the night of 4 December 2013, a sequence of polar cap patches was captured by an all-sky airglow imager (ASI) in Longyearbyen, Norway (78.1°N, 15.5°E). The 630.0 nm airglow images from the ASI of 4 second exposure time, oversampled the emission of natural lifetime (with quenching) of at least ˜30 sec, introduce no observational blurring effects. By using such high-quality ASI images, we succeeded in visualizing an asymmetry in the gradients between the leading/trailing edges of the patches in a 2-D fashion. The gradient in the leading edge was found to be 2-3 times steeper than that in the trailing edge. We also identified fingerlike structures, appearing only along the trailing edge of the patches, whose horizontal scale size ranged from 55 to 210 km. These fingers are considered to be manifestations of plasma structuring through the gradient-drift instability (GDI), which is known to occur only along the trailing edge of patches. That is, the current 2-D observations visualized, for the first time, how GDI stirs the patch plasma and such a mixing process makes the trailing edge more gradual. This result strongly implies a close connection between the GDI-driven plasma stirring and the asymmetry in the large-scale shape of patches and then suggests that the fingerlike structures can be used as markers to estimate the fine-scale structure in the plasma flow within patches.

The Impact of Involvement in Mortar Board Senior Honor Society on Lifelong Views of Civic Engagement and Leadership

ERIC Educational Resources Information Center

Turner, Daniel James

2012-01-01

This study examines the impact that involvement in Mortar Board National Senior Honor Society has on lifelong views of civic engagement and leadership. Mortar Board Senior Honor Society is a collegiate honor society established in 1918 that recognizes students for their outstanding contributions to their college or university community in the…

Strength and Durability Performance of Alkali-Activated Rice Husk Ash Geopolymer Mortar

PubMed Central

Kim, Yun Yong; Lee, Byung-Jae; Saraswathy, Velu

2014-01-01

This paper describes the experimental investigation carried out to develop the geopolymer concrete based on alkali-activated rice husk ash (RHA) by sodium hydroxide with sodium silicate. Effect on method of curing and concentration of NaOH on compressive strength as well as the optimum mix proportion of geopolymer mortar was investigated. It is possible to achieve compressive strengths of 31 N/mm2 and 45 N/mm2, respectively for the 10 M alkali-activated geopolymer mortar after 7 and 28 days of casting when cured for 24 hours at 60°C. Results indicated that the increase in curing period and concentration of alkali activator increased the compressive strength. Durability studies were carried out in acid and sulfate media such as H2SO4, HCl, Na2SO4, and MgSO4 environments and found that geopolymer concrete showed very less weight loss when compared to steam-cured mortar specimens. In addition, fluorescent optical microscopy and X-ray diffraction (XRD) studies have shown the formation of new peaks and enhanced the polymerization reaction which is responsible for strength development and hence RHA has great potential as a substitute for ordinary Portland cement concrete. PMID:25506063

Strength and durability performance of alkali-activated rice husk ash geopolymer mortar.

PubMed

Kim, Yun Yong; Lee, Byung-Jae; Saraswathy, Velu; Kwon, Seung-Jun

2014-01-01

This paper describes the experimental investigation carried out to develop the geopolymer concrete based on alkali-activated rice husk ash (RHA) by sodium hydroxide with sodium silicate. Effect on method of curing and concentration of NaOH on compressive strength as well as the optimum mix proportion of geopolymer mortar was investigated. It is possible to achieve compressive strengths of 31 N/mm(2) and 45 N/mm(2), respectively for the 10 M alkali-activated geopolymer mortar after 7 and 28 days of casting when cured for 24 hours at 60°C. Results indicated that the increase in curing period and concentration of alkali activator increased the compressive strength. Durability studies were carried out in acid and sulfate media such as H2SO4, HCl, Na2SO4, and MgSO4 environments and found that geopolymer concrete showed very less weight loss when compared to steam-cured mortar specimens. In addition, fluorescent optical microscopy and X-ray diffraction (XRD) studies have shown the formation of new peaks and enhanced the polymerization reaction which is responsible for strength development and hence RHA has great potential as a substitute for ordinary Portland cement concrete.

Aging and Curing Temperature Effects on Compressive Strength of Mortar Containing Lime Stone Quarry Dust and Industrial Granite Sludge.

PubMed

Amin, Muhammad Nasir; Khan, Kaffayatullah; Saleem, Muhammad Umair; Khurram, Nauman; Niazi, Muhammad Umar Khan

2017-06-11

In this study, the researchers investigated the potential use of locally available waste materials from the lime stone quarry and the granite industry as a partial replacement of cement. Quarry sites and granite industry in the eastern province of Saudi Arabia produces tons of powder wastes in the form of quarry dust (QD) and granite sludge (GS), respectively, causing serious environmental problems along with frequent dust storms in the area. According to ASTM C109, identical 50-mm3 specimens were cast throughout this study to evaluate the compressive strength development of mortars (7, 28 and 91 days) containing these waste materials. Experimental variables included different percentage replacement of cement with waste materials (GS, QD), fineness of GS, various curing temperatures (20, 40 and 60 °C as local normal and hot environmental temperatures) and curing moisture (continuously moist and partially moist followed by air curing). Finally, the results of mortar containing waste materials were compared to corresponding results of control mortar (CM) and mortar containing fly ash (FA). The test results indicated that under normal curing (20 °C, moist cured), the compressive strength of mortar containing the different percentage of waste materials (QD, GS, FA and their combinations) remained lower than that of CM at all ages. However, the compressive strength of mortar containing waste materials slightly increased with increased fineness of GS and significantly increased under high curing temperatures. It was recommended that more fineness of GS be achieved to use its high percentage replacement with cement (30% or more) incorporating local environmental conditions.

Aging and Curing Temperature Effects on Compressive Strength of Mortar Containing Lime Stone Quarry Dust and Industrial Granite Sludge

PubMed Central

Amin, Muhammad Nasir; Khan, Kaffayatullah; Saleem, Muhammad Umair; Khurram, Nauman; Niazi, Muhammad Umar Khan

2017-01-01

In this study, the researchers investigated the potential use of locally available waste materials from the lime stone quarry and the granite industry as a partial replacement of cement. Quarry sites and granite industry in the eastern province of Saudi Arabia produces tons of powder wastes in the form of quarry dust (QD) and granite sludge (GS), respectively, causing serious environmental problems along with frequent dust storms in the area. According to ASTM C109, identical 50-mm3 specimens were cast throughout this study to evaluate the compressive strength development of mortars (7, 28 and 91 days) containing these waste materials. Experimental variables included different percentage replacement of cement with waste materials (GS, QD), fineness of GS, various curing temperatures (20, 40 and 60 °C as local normal and hot environmental temperatures) and curing moisture (continuously moist and partially moist followed by air curing). Finally, the results of mortar containing waste materials were compared to corresponding results of control mortar (CM) and mortar containing fly ash (FA). The test results indicated that under normal curing (20 °C, moist cured), the compressive strength of mortar containing the different percentage of waste materials (QD, GS, FA and their combinations) remained lower than that of CM at all ages. However, the compressive strength of mortar containing waste materials slightly increased with increased fineness of GS and significantly increased under high curing temperatures. It was recommended that more fineness of GS be achieved to use its high percentage replacement with cement (30% or more) incorporating local environmental conditions. PMID:28772999

Experimental study of the mechanical stabilization of electric arc furnace dust using fluid cement mortars.

PubMed

Ledesma, E F; Jiménez, J R; Ayuso, J; Fernández, J M; Brito, J de

2017-03-15

This article shows the results of an experimental study carried out in order to determine the maximum amount of electric arc furnace dust (EAFD) that can be incorporated into fluid cement-based mortars to produce mechanically stable monolithic blocks. The leaching performance of all mixes was studied in order to classify them according to the EU Council Decision 2003/33/EC. Two mortars were used as reference and three levels of EAFD incorporation were tested in each of the reference mortars. As the incorporation ratio of EAFD/cement increases, the mechanical strength decreases. This is due to the greater EAFD/cement and water/cement ratios, besides the presence of a double-hydrated hydroxide of Ca and Zn (CaZn 2 (OH) 6 ·2H 2 O) instead of the portlandite phase (Ca(OH) 2 ) in the mixes made with EAFD, as well as non-hydrated tricalcium silicate. A mass ratio of 2:1 (EAFD: cement-based mortar) can be added maintaining a stable mechanical strength. The mechanical stabilization process also reduced the leaching of metals, although it was not able to reduce the Pb concentration below the limit for hazardous waste. The high amount of EAFD mechanically stabilized in this experimental study can be useful to reduce the storage volume required in hazardous waste landfills. Copyright © 2016 Elsevier B.V. All rights reserved.

Determination of Chlorinated Solvent Sorption by Porous Material-Application to Trichloroethene Vapor on Cement Mortar.

PubMed

Musielak, Marion; Brusseau, Mark L; Marcoux, Manuel; Morrison, Candice; Quintard, Michel

2014-08-01

Experiments have been performed to investigate the sorption of trichloroethene (TCE) vapor by concrete material or, more specifically, the cement mortar component. Gas-flow experiments were conducted using columns packed with small pieces of cement mortar obtained from the grinding of typical concrete material. Transport and retardation of TCE at high vapor concentrations (500 mg L -1 ) was compared to that of a non-reactive gas tracer (Sulfur Hexafluoride, SF6). The results show a large magnitude of retardation (retardation factor = 23) and sorption (sorption coefficient = 10.6 cm 3 g -1 ) for TCE, compared to negligible sorption for SF6. This magnitude of sorption obtained with pollutant vapor is much bigger than the one obtained for aqueous-flow experiments conducted for water-saturated systems. The considerable sorption exhibited for TCE under vapor-flow conditions is attributed to some combination of accumulation at the air-water interface and vapor-phase adsorption, both of which are anticipated to be significant for this system given the large surface area associated with the cement mortar. Transport of both SF6 and TCE was simulated successfully with a two-region physical non-equilibrium model, consistent with the dual-medium structure of the crushed cement mortar. This work emphasizes the importance of taking into account sorption phenomena when modeling transport of volatile organic compounds through concrete material, especially in regard to assessing vapor intrusion.

Patching. Restitching business portfolios in dynamic markets.

PubMed

Eisenhardt, K M; Brown, S L

1999-01-01

In turbulent markets, businesses and opportunities are constantly falling out of alignment. New technologies and emerging markets create fresh opportunities. Converging markets produce more. And of course, some markets fade. In this landscape of continuous flux, it's more important to build corporate-level strategic processes that enable dynamic repositioning than it is to build any particular defensible position. That's why smart corporate strategists use patching, a process of mapping and remapping business units to create a shifting mix of highly focused, tightly aligned businesses that can respond to changing market opportunities. Patching is not just another name for reorganizing; patchers have a distinctive mindset. Traditional managers see structure as stable; patching managers believe structure is inherently temporary. Traditional managers set corporate strategy first, but patching managers keep the organization focused on the right set of business opportunities and let strategy emerge from individual businesses. Although the focus of patching is flexibility, the process itself follows a pattern. Patching changes are usually small in scale and made frequently. Patching should be done quickly; the emphasis is on getting the patch about right and fixing problems later. Patches should have a test drive before they're formalized but then be tightly scripted after they've been announced. And patching won't work without the right infrastructure: modular business units, fine-grained and complete unit-level metrics, and companywide compensation parity. The authors illustrate how patching works and point out some common stumbling blocks.

The Properties of Mortar Mixtures Blended with Natural, Crushed, and Recycled Fine Aggregates for Building Construction Materials

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

Yu, Myoung-Youl; Lee, Jae-Yong; Chung, Chul-Woo

2012-01-12

In this research, the possible applicability of fine aggregates blended with natural, crushed, and recycled fine aggregate are discussed. The fresh and hardened properties of mortar using blended fine aggregates are monitored depending on various blending ratio of fine aggregates. Newly developed ternary diagram was also utilized for better interpretation of the data. It was found that air content increased and unit weight decreased as recycled fine aggregate content increased. With moisture type processing of recycled fine aggregate, the mortar flow was not negatively affected by increase in the recycled fine aggregate content. The ternary diagram is found to bemore » an effective graphical presentation tool that can be used for the quality evaluation of mortar using blended fine aggregate.« less

SEM Analysis of the Interfacial Transition Zone between Cement-Glass Powder Paste and Aggregate of Mortar under Microwave Curing

PubMed Central

Kong, Yaning; Wang, Peiming; Liu, Shuhua; Zhao, Guorong; Peng, Yu

2016-01-01

In order to investigate the effects of microwave curing on the microstructure of the interfacial transition zone of mortar prepared with a composite binder containing glass powder and to explain the mechanism of microwave curing on the improvement of compressive strength, in this study, the compressive strength of mortar under microwave curing was compared against mortar cured using (a) normal curing at 20 ± 1 °C with relative humidity (RH) > 90%; (b) steam curing at 40 °C for 10 h; and (c) steam curing at 80 °C for 4 h. The microstructure of the interfacial transition zone of mortar under the four curing regimes was analyzed by Scanning electron microscopy (SEM). The results showed that the improvement of the compressive strength of mortar under microwave curing can be attributed to the amelioration of the microstructure of the interfacial transition zone. The hydration degree of cement is accelerated by the thermal effect of microwave curing and Na+ partially dissolved from the fine glass powder to form more reticular calcium silicate hydrate, which connects the aggregate, calcium hydroxide, and non-hydrated cement and glass powder into a denser integral structure. In addition, a more stable triangular structure of calcium hydroxide contributes to the improvement of compressive strength. PMID:28773854

SEM Analysis of the Interfacial Transition Zone between Cement-Glass Powder Paste and Aggregate of Mortar under Microwave Curing.

PubMed

Kong, Yaning; Wang, Peiming; Liu, Shuhua; Zhao, Guorong; Peng, Yu

2016-08-27

In order to investigate the effects of microwave curing on the microstructure of the interfacial transition zone of mortar prepared with a composite binder containing glass powder and to explain the mechanism of microwave curing on the improvement of compressive strength, in this study, the compressive strength of mortar under microwave curing was compared against mortar cured using (a) normal curing at 20 ± 1 °C with relative humidity (RH) > 90%; (b) steam curing at 40 °C for 10 h; and (c) steam curing at 80 °C for 4 h. The microstructure of the interfacial transition zone of mortar under the four curing regimes was analyzed by Scanning electron microscopy (SEM). The results showed that the improvement of the compressive strength of mortar under microwave curing can be attributed to the amelioration of the microstructure of the interfacial transition zone. The hydration degree of cement is accelerated by the thermal effect of microwave curing and Na⁺ partially dissolved from the fine glass powder to form more reticular calcium silicate hydrate, which connects the aggregate, calcium hydroxide, and non-hydrated cement and glass powder into a denser integral structure. In addition, a more stable triangular structure of calcium hydroxide contributes to the improvement of compressive strength.

Influence of habitat quality, population size, patch size, and connectivity on patch-occupancy dynamics of the middle spotted woodpecker.

PubMed

Robles, Hugo; Ciudad, Carlos

2012-04-01

Despite extensive research on the effects of habitat fragmentation, the ecological mechanisms underlying colonization and extinction processes are poorly known, but knowledge of these mechanisms is essential to understanding the distribution and persistence of populations in fragmented habitats. We examined these mechanisms through multiseason occupancy models that elucidated patch-occupancy dynamics of Middle Spotted Woodpeckers (Dendrocopos medius) in northwestern Spain. The number of occupied patches was relatively stable from 2000 to 2010 (15-24% of 101 patches occupied every year) because extinction was balanced by recolonization. Larger and higher quality patches (i.e., higher density of oaks >37 cm dbh [diameter at breast height]) were more likely to be occupied. Habitat quality (i.e., density of large oaks) explained more variation in patch colonization and extinction than did patch size and connectivity, which were both weakly associated with probabilities of turnover. Patches of higher quality were more likely to be colonized than patches of lower quality. Populations in high-quality patches were less likely to become extinct. In addition, extinction in a patch was strongly associated with local population size but not with patch size, which means the latter may not be a good surrogate of population size in assessments of extinction probability. Our results suggest that habitat quality may be a primary driver of patch-occupancy dynamics and may increase the accuracy of models of population survival. We encourage comparisons of competing models that assess occupancy, colonization, and extinction probabilities in a single analytical framework (e.g., dynamic occupancy models) so as to shed light on the association of habitat quality and patch geometry with colonization and extinction processes in different settings and species. ©2012 Society for Conservation Biology.

FuncPatch: a web server for the fast Bayesian inference of conserved functional patches in protein 3D structures.

PubMed

Huang, Yi-Fei; Golding, G Brian

2015-02-15

A number of statistical phylogenetic methods have been developed to infer conserved functional sites or regions in proteins. Many methods, e.g. Rate4Site, apply the standard phylogenetic models to infer site-specific substitution rates and totally ignore the spatial correlation of substitution rates in protein tertiary structures, which may reduce their power to identify conserved functional patches in protein tertiary structures when the sequences used in the analysis are highly similar. The 3D sliding window method has been proposed to infer conserved functional patches in protein tertiary structures, but the window size, which reflects the strength of the spatial correlation, must be predefined and is not inferred from data. We recently developed GP4Rate to solve these problems under the Bayesian framework. Unfortunately, GP4Rate is computationally slow. Here, we present an intuitive web server, FuncPatch, to perform a fast approximate Bayesian inference of conserved functional patches in protein tertiary structures. Both simulations and four case studies based on empirical data suggest that FuncPatch is a good approximation to GP4Rate. However, FuncPatch is orders of magnitudes faster than GP4Rate. In addition, simulations suggest that FuncPatch is potentially a useful tool complementary to Rate4Site, but the 3D sliding window method is less powerful than FuncPatch and Rate4Site. The functional patches predicted by FuncPatch in the four case studies are supported by experimental evidence, which corroborates the usefulness of FuncPatch. The software FuncPatch is freely available at the web site, http://info.mcmaster.ca/yifei/FuncPatch golding@mcmaster.ca Supplementary data are available at Bioinformatics online. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

PATIENTS' KNOWLEDGE OF MEDICAL PATCHES IN HUNGARY.

PubMed

Somogyi, Orsolya; Zelko, Romana

2016-11-01

Transdermal therapy with medical patches is a simple possibility in home medication. As the correct use of patches has a decisive impact from the point of its modulator effect.A questionnaire survey was developed to explore level of patients' knowledge of the correct use of transdermal patches. A survey was administered in thirteen Hungarian community pharmacies from October of 2012 to May of 2015. Most of the participants, men and women over 18 years of age (n = 233), used major analgesic patches (fentanyl); the remainder were given nitroglycerin, NSAID analgesics patches during the survey. For the hypothesis testing it was assumed that men were more likely to use a razor for skin depilation before patch application than women as their denser pelage hinders patch adhesion. The hypothesis testing showed no significant gender difference in razor use (X² = 0.201; p = 0.654). Pharmacists should direct patients to avoid using soap for skin cleansing before patch application because only 22 percent of the participants always avoided its use. Since only 9 tests were flawless from 233 completed questionnaires. Many patients do not understand how to correctly apply a transdermal dosage patch. Pharmacists should teach their correct application based on results.

Sand/cement ratio evaluation on mortar using neural networks and ultrasonic transmission inspection.

PubMed

Molero, M; Segura, I; Izquierdo, M A G; Fuente, J V; Anaya, J J

2009-02-01

The quality and degradation state of building materials can be determined by nondestructive testing (NDT). These materials are composed of a cementitious matrix and particles or fragments of aggregates. Sand/cement ratio (s/c) provides the final material quality; however, the sand content can mask the matrix properties in a nondestructive measurement. Therefore, s/c ratio estimation is needed in nondestructive characterization of cementitious materials. In this study, a methodology to classify the sand content in mortar is presented. The methodology is based on ultrasonic transmission inspection, data reduction, and features extraction by principal components analysis (PCA), and neural network classification. This evaluation is carried out with several mortar samples, which were made while taking into account different cement types and s/c ratios. The estimated s/c ratio is determined by ultrasonic spectral attenuation with three different broadband transducers (0.5, 1, and 2 MHz). Statistical PCA to reduce the dimension of the captured traces has been applied. Feed-forward neural networks (NNs) are trained using principal components (PCs) and their outputs are used to display the estimated s/c ratios in false color images, showing the s/c ratio distribution of the mortar samples.

Patch-clamp amplifiers on a chip

PubMed Central

Weerakoon, Pujitha; Culurciello, Eugenio; Yang, Youshan; Santos-Sacchi, Joseph; Kindlmann, Peter J.; Sigworth, Fred J.

2010-01-01

We present the first, fully-integrated, two-channel implementation of a patch-clamp measurement system. With this “PatchChip” two simultaneous whole-cell recordings can be obtained with rms noise of 8 pA in a 10 kHz bandwidth. The capacitance and series-resistance of the electrode can be compensated up to 10 pF and 100 MΩ respectively under computer control. Recordings of hERG and Nav 1.7 currents demonstrate the system's capabilities, which are on par with large, commercial patch-clamp instrumentation. By reducing patch-clamp amplifiers to a millimeter size micro-chip, this work paves the way to the realization of massively-parallel, high-throughput patch-clamp systems for drug screening and ion-channel research. The PatchChip is implemented in a 0.5 μm silicon-on-sapphire process; its size is 3 × 3 mm2 and the power consumption is 5 mW per channel with a 3.3 V power supply. PMID:20637803

Wastes as Aggregates, Binders or Additions in Mortars: Selecting Their Role Based on Characterization.

PubMed

Farinha, Catarina Brazão; de Brito, Jorge; Veiga, Rosário; Fernández, J M; Jiménez, J R; Esquinas, A R

2018-03-20

The production of waste has increased over the years and, lacking a recycle or recovery solution, it is forwarded to landfill. The incorporation of wastes in cement-based materials is a solution to reduce waste deposition. In this regard, some researchers have been studying the incorporation of wastes with different functions: aggregate, binder and addition. The incorporation of wastes should take advantage of their characteristics. It requires a judicious analysis of their particles. This research involves the analysis of seven industrial wastes: biomass ashes, glass fibre, reinforced polymer dust, sanitary ware, fluid catalytic cracking, acrylic fibre, textile fibre and glass fibre. The main characteristics and advantages of each waste are enunciated and the best type of introduction in mortars is discussed. The characterization of the wastes as particles is necessary to identify the most suitable incorporation in mortars. In this research, some wastes are studied with a view to their re-use or recycling in mortars. Thus, this research focuses on the chemical, physical and mechanical characterization of industrial wastes and identification of the potentially most advantageous type of incorporation.

Sustainability, Eco-Point and Engineering Performance of Different Workability OPC Fly-Ash Mortar Mixes.

PubMed

Razi, Putri Zulaiha; Abdul Razak, Hashim; Khalid, Nur Hafizah A

2016-05-06

This study investigates the engineering performance and CO₂ footprint of mortar mixers by replacing Portland cement with 10%, 20%, 40% and 60% fly ash, a common industrial waste material. Samples of self-compacting mortar (SCM) were prepared with four different water/binder ratios and varying dosages of superplasticizer to give three ranges of workability, i.e. , normal, high and self-compacting mortar mix. The engineering performance was assessed in term of compressive strength after designated curing periods for all mixes. CO₂ footprint was the environmental impact indicator of each production stage. The optimum mix obtained was at 10% replacement rate for all mixes. Total production emission reduced by 56% when the fly ash replacement rate increased from 0% to 60% (maximum). This is translated to a reduction of 80% in eco-points (assuming that the energy consumption rate of production with 0% fly ash is at 100%). Such re-utilization is encouraged since it is able to reduce possible soil toxicity due to sulfur leaching by 5% to 27% and landfill area by 15% to 91% on average.

Wastes as Aggregates, Binders or Additions in Mortars: Selecting Their Role Based on Characterization

PubMed Central

de Brito, Jorge; Veiga, Rosário

2018-01-01

The production of waste has increased over the years and, lacking a recycle or recovery solution, it is forwarded to landfill. The incorporation of wastes in cement-based materials is a solution to reduce waste deposition. In this regard, some researchers have been studying the incorporation of wastes with different functions: aggregate, binder and addition. The incorporation of wastes should take advantage of their characteristics. It requires a judicious analysis of their particles. This research involves the analysis of seven industrial wastes: biomass ashes, glass fibre, reinforced polymer dust, sanitary ware, fluid catalytic cracking, acrylic fibre, textile fibre and glass fibre. The main characteristics and advantages of each waste are enunciated and the best type of introduction in mortars is discussed. The characterization of the wastes as particles is necessary to identify the most suitable incorporation in mortars. In this research, some wastes are studied with a view to their re-use or recycling in mortars. Thus, this research focuses on the chemical, physical and mechanical characterization of industrial wastes and identification of the potentially most advantageous type of incorporation. PMID:29558418

Sustainability, Eco-Point and Engineering Performance of Different Workability OPC Fly-Ash Mortar Mixes

PubMed Central

Razi, Putri Zulaiha; Abdul Razak, Hashim; Khalid, Nur Hafizah A.

2016-01-01

This study investigates the engineering performance and CO2 footprint of mortar mixers by replacing Portland cement with 10%, 20%, 40% and 60% fly ash, a common industrial waste material. Samples of self-compacting mortar (SCM) were prepared with four different water/binder ratios and varying dosages of superplasticizer to give three ranges of workability, i.e., normal, high and self-compacting mortar mix. The engineering performance was assessed in term of compressive strength after designated curing periods for all mixes. CO2 footprint was the environmental impact indicator of each production stage. The optimum mix obtained was at 10% replacement rate for all mixes. Total production emission reduced by 56% when the fly ash replacement rate increased from 0% to 60% (maximum). This is translated to a reduction of 80% in eco-points (assuming that the energy consumption rate of production with 0% fly ash is at 100%). Such re-utilization is encouraged since it is able to reduce possible soil toxicity due to sulfur leaching by 5% to 27% and landfill area by 15% to 91% on average. PMID:28773465

The effects of bauxite, metakaolin, and porosity on the thermal properties of prepared Iraqi clays refractory mortars

NASA Astrophysics Data System (ADS)

Zaidan, Shihab A.; Omar, Mustafa H.

2018-05-01

One of the most important requirements for the manufacture of refractory mortars, especially those used in the construction of thermal systems (building or plastering), is the balance between thermal insulation properties and porosity. Where, increasing porosity of mortar to a large amount may be always undesirable, because the absorption of liquid and gases emitted from industrial system is decline the bonded with bricks and structural properties of mortars. Refractory mortars prepared from either fired bauxite or metakaolin clays with different percentages of kaolin (10, 20, 30, and 40 wt%). Bauxite rocks were fired at 1200 °C and metakaolin was obtained by firing kaolin up to 700 °C then crushed and grinded. Grog was added to mixture to reduce the shrinkage. Cylindrical specimens are prepared and then sintered at 1200 °C. All mixtures maintained a low thermal conductivity within the limits of thermal insulation material (less than 0.5 W/m K); it was done by controlling the porosity which reached a maximum value approximately 25%. The volumetric heat capacity and thermal diffusivity was ranged between (1-10 MJ/m3 K), (0.06-0.2 mm2/s), respectively.

Assessment of Pb-slag, MSWI bottom ash and boiler and fly ash for using as a fine aggregate in cement mortar.

PubMed

Saikia, Nabajyoti; Cornelis, Geert; Mertens, Gilles; Elsen, Jan; Van Balen, Koenraad; Van Gerven, Tom; Vandecasteele, Carlo

2008-06-15

Three types of wastes, metallurgical slag from Pb production (SLG), the sand-sized (0.1-2 mm) fraction of MSWI bottom ash from a grate furnace (SF), and boiler and fly ash from a fluidised bed incinerator (BFA), were characterized and used to replace the fine aggregate during preparation of cement mortar. The chemical and mineralogical behaviour of these wastes along with the reactivities of the wastes with lime and the hydration behaviour of ordinary Portland cement paste with and without these wastes added were evaluated by various chemical and instrumental techniques. The compressive strengths of the cement mortars containing waste as a partial substitution of fine aggregates were also assessed. Finally, leaching studies of the wastes and waste containing cement mortars were conducted. SLG addition does not show any adverse affect during the hydration of cement, or on the compressive strengths behaviours of mortars. Formation of expansive products like ettringite, aluminium hydroxide and H2 gas due to the reaction of some constituents of BFA and SF with alkali creates some cracks in the paste as well as in the cement mortars, which lower the compressive strength of the cement mortars. However, utilization of all materials in cement-based application significantly improves the leaching behaviour of the majority of the toxic elements compared to the waste as such.

2. VIEW, LOOKING FROM THE NORTHEAST. THESE THREE CONCRETE MORTAR ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

2. VIEW, LOOKING FROM THE NORTHEAST. THESE THREE CONCRETE MORTAR BLOCKS WERE FOR THE MILL'S 3-STAMP BATTERIES ERECTED IN 1903, NORTH OF THE TWO 1901 BATTERIES WHICH WERE MOUNTED ON WOODEN TIMBERS - Wilbur-Womble Mill, Southern Edge Of Salt Spring Valley, Copperopolis, Calaveras County, CA

Quasi-static and dynamic experimental studies on the tensile strength and failure pattern of concrete and mortar discs.

PubMed

Jin, Xiaochao; Hou, Cheng; Fan, Xueling; Lu, Chunsheng; Yang, Huawei; Shu, Xuefeng; Wang, Zhihua

2017-11-10

As concrete and mortar materials widely used in structural engineering may suffer dynamic loadings, studies on their mechanical properties under different strain rates are of great importance. In this paper, based on splitting tests of Brazilian discs, the tensile strength and failure pattern of concrete and mortar were investigated under quasi-static and dynamic loadings with a strain rate of 1-200 s -1 . It is shown that the quasi-static tensile strength of mortar is higher than that of concrete since coarse aggregates weaken the interface bonding strength of the latter. Numerical results confirmed that the plane stress hypothesis lead to a lower value tensile strength for the cylindrical specimens. With the increase of strain rates, dynamic tensile strengths of concrete and mortar significantly increase, and their failure patterns change form a single crack to multiple cracks and even fragment. Furthermore, a relationship between the dynamic increase factor and strain rate was established by using a linear fitting algorithm, which can be conveniently used to calculate the dynamic increase factor of concrete-like materials in engineering applications.

Comparison between over-glasses patching and adhesive patching for children with moderate amblyopia: a prospective randomized clinical trial.

PubMed

Kim, Su Jin; Jeon, Hyeshin; Jung, Jae Ho; Lee, Kwang Min; Choi, Hee Young

2018-02-01

To investigate efficacy of over-glasses patching treatment for amblyopic children using visual function improvement and Amblyopia Treatment Index (ATI) changes. In a randomized multi-center controlled clinical trial, 107 children aged 3-7 years with moderate amblyopia (visual acuity in the range of 20/40 to 20/100) were included to receive treatment with either an adhesive skin patch or a fabric over-glasses patch. The patients were prescribed 2 h of patching per day for the sound eye. Best-corrected visual acuity (BCVA) was investigated and ATI questionnaires were collected from parents at 5 weeks and 17 weeks after the initiation of treatment. ATI identifies barriers and problems associated with amblyopia treatment. We compared the changes of visual acuity of amblyopic eyes and ATI scores in two groups. At 17 weeks, the mean visual acuity of the amblyopic eye using Snellen chart improved 3.2 lines in the adhesive patching group and 2.7 lines for an over-glasses patching method that fit over eyeglasses (p = 0.345). A similar proportion of subjects in each group had improvement of ≥ 2 lines (adhesive patching group 67% vs over-glasses patching group 67%, p = 0.372). There was also no difference in treatment burden in each group as measured with the Amblyopia Treatment Index. The only item to demonstrate a significant difference between groups was that related to "Treatment makes the eye or eyelids red" (mean 4.0 ± 1.1 vs 3.0 ± 1.0 at 17 weeks, p = 0.001, for adhesive vs over-glasses patch). Over-glasses patching treatment is a useful option for amblyopia treatment when the patients suffer from adverse effects of using adhesive skin patching.

Dynamic tensile fracture of mortar at ultra-high strain-rates

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

Erzar, B., E-mail: benjamin.erzar@cea.fr; Buzaud, E.; Chanal, P.-Y.

2013-12-28

During the lifetime of a structure, concrete and mortar may be exposed to highly dynamic loadings, such as impact or explosion. The dynamic fracture at high loading rates needs to be well understood to allow an accurate modeling of this kind of event. In this work, a pulsed-power generator has been employed to conduct spalling tests on mortar samples at strain-rates ranging from 2 × 10{sup 4} to 4 × 10{sup 4} s{sup −1}. The ramp loading allowed identifying the strain-rate anytime during the test. A power law has been proposed to fit properly the rate-sensitivity of tensile strength of thismore » cementitious material over a wide range of strain-rate. Moreover, a specimen has been recovered damaged but unbroken. Micro-computed tomography has been employed to study the characteristics of the damage pattern provoked by the dynamic tensile loading.« less

Material Performance and Animal Clinical Studies on Performance-Optimized Hwangtoh Mixed Mortar and Concrete to Evaluate Their Mechanical Properties and Health Benefits

PubMed Central

Koo, Bon-Min; Kim, Jang-Ho Jay; Kim, Tae-Kyun; Kim, Byung-Yun

2015-01-01

In this study, the amount of cement used in a concrete mix is minimized to reduce the toxic effects on users by adjusting the concrete mixture contents. The reduction of cement is achieved by using various admixtures (ground granulated blast-furnace slag, flyash, ordinary Portland cement, and activated Hwangtoh powder). To apply the mix to construction, material property tests such as compressive strength, slump, and pH are performed. Preliminary experimental results showed that the Hwangtoh concrete could be used as a healthy construction material. Also, the health issues and effects of Hwangtoh mortar are quantitatively evaluated through an animal clinical test. Mice are placed in Hwangtoh mortar and cement mortar cages to record their activity. For the test, five cages are made with Hwangtoh and ordinary Portland cement mortar floors, using Hwangtoh powder replacement ratios of 20%, 40%, 60%, and 80% of the normal cement mortar mixing ratio, and two cages are made with Hwangtoh mortar living quarters. The activity parameter measurements included weight, food intake, water intake, residential space selection, breeding activity, and aggression. The study results can be used to evaluate the benefits of using Hwangtoh as a cement replacing admixture for lifestyle, health and sustainability. PMID:28793563

Investigation of Hydraulic Binding Characteristics of Lime Based Mortars Used in Historical Masonry Structures

NASA Astrophysics Data System (ADS)

Binal, Adil

2017-10-01

In the historic masonry structures, hard and large rock fragments were used as the construction materials. The hydraulic binder material prepared to keep this used material in its entirety is a different material than the cement used today. Khorasan mortar made by using aggregate and lime exhibits a more flexible structure than the concrete. This feature allows the historic building to be more durable. There is also a significant industrial value because of the use of Khorasan mortar in the restoration of historic masonry structures. Therefore, the calculation of the ideal mixture of Khorasan mortar and the determination of its mechanical and physical properties are of great importance regarding preserving historic buildings. In this study, the mixtures of different lime and brick fractions were prepared. It was determined that Khorasan mortar shows the highest compressive strength in mixtures with water/lime ratio of 0.55 and lime/aggregate ratio of 0.66. By keeping the mixing ratio constant, it was observed that the strengths of the samples kept in the humidity chamber for different curing times increased day by day. The early strength values of samples with the high lime/aggregate ratio (l/a: 0.83) were higher than those with the low lime/aggregate ratio (l/a: 0.5). For the samples with low lime/aggregate ratio, there was an increase in the strength values depending on the curing period. As the cure duration increases, a chemical reaction takes place between the lime and the brick fracture, and as a result of this reaction, the strength values are increased.

Patch forest: a hybrid framework of random forest and patch-based segmentation

NASA Astrophysics Data System (ADS)

Xie, Zhongliu; Gillies, Duncan

2016-03-01

The development of an accurate, robust and fast segmentation algorithm has long been a research focus in medical computer vision. State-of-the-art practices often involve non-rigidly registering a target image with a set of training atlases for label propagation over the target space to perform segmentation, a.k.a. multi-atlas label propagation (MALP). In recent years, the patch-based segmentation (PBS) framework has gained wide attention due to its advantage of relaxing the strict voxel-to-voxel correspondence to a series of pair-wise patch comparisons for contextual pattern matching. Despite a high accuracy reported in many scenarios, computational efficiency has consistently been a major obstacle for both approaches. Inspired by recent work on random forest, in this paper we propose a patch forest approach, which by equipping the conventional PBS with a fast patch search engine, is able to boost segmentation speed significantly while retaining an equal level of accuracy. In addition, a fast forest training mechanism is also proposed, with the use of a dynamic grid framework to efficiently approximate data compactness computation and a 3D integral image technique for fast box feature retrieval.

Unusual fentanyl patch administration.

PubMed

Thomas, Sandra; Winecker, Ruth; Pestaner, Joseph P

2008-06-01

Fentanyl is an extremely potent narcotic analgesic that is becoming more popular as a drug of abuse. Because of the unique way in which the drug is packaged and delivered, the potential for unusual methods of abuse exists. We report the first case of true fentanyl patch ingestion in the medical literature. Initially, though unusual, cases of fentanyl ingestion were thought to have been reported, but further investigation of the literature revealed that in other case reports the patches had been held in the mouth and chewed. Because no reports of swallowing the patch had been published, suicide was initially a strong consideration in this case; however, further investigation showed that the decedent and his brother enjoyed swallowing the patches for quick "highs." Cases such as these serve to remind medical examiners and law enforcement officials of the value of performing thorough death investigations by performing complete autopsies with toxicological testing and correlating with investigation information to form an opinion with regard to the cause and manner of death.

Response to rivastigmine transdermal patch or memantine plus rivastigmine patch is affected by apolipoprotein E genotype in Alzheimer patients.

PubMed

Han, Hyun Jeong; Kim, Byeong C; Lee, Jun-Young; Ryu, Seung-Ho; Na, Hae Ri; Yoon, Soo Jin; Park, Hyun Young; Shin, Joon Hyun; Cho, Soo-Jin; Yi, Hyon-Ah; Choi, Mun Seong; Heo, Jae-Hyeok; Park, Kyung Won; Kim, Kwang K; Choi, Seong Hye

2012-01-01

The apolipoprotein E (APOE) genotype in response to pharmacological treatments in patients with Alzheimer's disease (AD) remains a matter of controversy. This analysis investigated the effect of the APOE genotype on the clinical response to rivastigmine transdermal patch monotherapy or memantine plus rivastigmine patch in patients with mild to moderate AD. Two hundred and six (n = 206) patients with probable AD and Mini-Mental State Examination (MMSE) scores of 10-20 were randomized to rivastigmine patch monotherapy or memantine plus rivastigmine patch for 24 weeks. Of the 206 patients with probable AD, 146 patients who consented to genetic testing for APOE were included and assessed for this subgroup study. There were no significant differences on MMSE, NPI, ADAS-cog, ADCS-ADL, CDR-SB, NPI and FAB between rivastigmine patch monotherapy and memantine plus rivastigmine patch according to the APOE genotype. However, patients with moderately severe AD (MMSE ≤15) who were APOE ε4 carriers showed higher responder rates on ADCS-ADL with memantine plus rivastigmine patch compared to rivastigmine patch monotherapy. Moderately severe AD patients with the APOE ε4 allele may respond more favorably to memantine plus rivastigmine patch than ε4 noncarriers. Copyright © 2012 S. Karger AG, Basel.

Mechanical resilience and cementitious processes in Imperial Roman architectural mortar.

PubMed

Jackson, Marie D; Landis, Eric N; Brune, Philip F; Vitti, Massimo; Chen, Heng; Li, Qinfei; Kunz, Martin; Wenk, Hans-Rudolf; Monteiro, Paulo J M; Ingraffea, Anthony R

2014-12-30

The pyroclastic aggregate concrete of Trajan's Markets (110 CE), now Museo Fori Imperiali in Rome, has absorbed energy from seismic ground shaking and long-term foundation settlement for nearly two millenia while remaining largely intact at the structural scale. The scientific basis of this exceptional service record is explored through computed tomography of fracture surfaces and synchroton X-ray microdiffraction analyses of a reproduction of the standardized hydrated lime-volcanic ash mortar that binds decimeter-sized tuff and brick aggregate in the conglomeratic concrete. The mortar reproduction gains fracture toughness over 180 d through progressive coalescence of calcium-aluminum-silicate-hydrate (C-A-S-H) cementing binder with Ca/(Si+Al) ≈ 0.8-0.9 and crystallization of strätlingite and siliceous hydrogarnet (katoite) at ≥ 90 d, after pozzolanic consumption of hydrated lime was complete. Platey strätlingite crystals toughen interfacial zones along scoria perimeters and impede macroscale propagation of crack segments. In the 1,900-y-old mortar, C-A-S-H has low Ca/(Si+Al) ≈ 0.45-0.75. Dense clusters of 2- to 30-µm strätlingite plates further reinforce interfacial zones, the weakest link of modern cement-based concrete, and the cementitious matrix. These crystals formed during long-term autogeneous reaction of dissolved calcite from lime and the alkali-rich scoriae groundmass, clay mineral (halloysite), and zeolite (phillipsite and chabazite) surface textures from the Pozzolane Rosse pyroclastic flow, erupted from the nearby Alban Hills volcano. The clast-supported conglomeratic fabric of the concrete presents further resistance to fracture propagation at the structural scale.

Mechanical resilience and cementitious processes in Imperial Roman architectural mortar

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

Jackson, Marie D.; Landis, Eric N.; Brune, Philip F.

The pyroclastic aggregate concrete of Trajan’s Markets (110 CE), now Museo Fori Imperiali in Rome, has absorbed energy from seismic ground shaking and long-term foundation settlement for nearly two millenia while remaining largely intact at the structural scale. The scientific basis of this exceptional service record is explored through computed tomography of fracture surfaces and synchroton X-ray microdiffraction analyses of a reproduction of the standardized hydrated lime–volcanic ash mortar that binds decimeter-sized tuff and brick aggregate in the conglomeratic concrete. The mortar reproduction gains fracture toughness over 180 d through progressive coalescence of calcium–aluminum-silicate–hydrate (C-A-S-H) cementing binder with Ca/(Si+Al) ≈more » 0.8–0.9 and crystallization of strätlingite and siliceous hydrogarnet (katoite) at ≥90 d, after pozzolanic consumption of hydrated lime was complete. Platey strätlingite crystals toughen interfacial zones along scoria perimeters and impede macroscale propagation of crack segments. In the 1,900 year old mortar, C-A-S-H has low Ca/(Si+Al) ≈ 0.45–0.75. Dense clusters of 2- to 30-µm strätlingite plates further reinforce interfacial zones, the weakest link of modern cement-based concrete, and the cementitious matrix. These crystals formed during long-term autogeneous reaction of dissolved calcite from lime and the alkali-rich scoriae groundmass, clay mineral (halloysite), and zeolite (phillipsite and chabazite) surface textures from the Pozzolane Rosse pyroclastic flow, erupted from the nearby Alban Hills volcano. The clast-supported conglomeratic fabric of the concrete presents further resistance to fracture propagation at the structural scale.« less

Mechanical resilience and cementitious processes in Imperial Roman architectural mortar

DOE PAGES

Jackson, Marie D.; Landis, Eric N.; Brune, Philip F.; ...

2014-12-15

The pyroclastic aggregate concrete of Trajan’s Markets (110 CE), now Museo Fori Imperiali in Rome, has absorbed energy from seismic ground shaking and long-term foundation settlement for nearly two millenia while remaining largely intact at the structural scale. The scientific basis of this exceptional service record is explored through computed tomography of fracture surfaces and synchroton X-ray microdiffraction analyses of a reproduction of the standardized hydrated lime–volcanic ash mortar that binds decimeter-sized tuff and brick aggregate in the conglomeratic concrete. The mortar reproduction gains fracture toughness over 180 d through progressive coalescence of calcium–aluminum-silicate–hydrate (C-A-S-H) cementing binder with Ca/(Si+Al) ≈more » 0.8–0.9 and crystallization of strätlingite and siliceous hydrogarnet (katoite) at ≥90 d, after pozzolanic consumption of hydrated lime was complete. Platey strätlingite crystals toughen interfacial zones along scoria perimeters and impede macroscale propagation of crack segments. In the 1,900 year old mortar, C-A-S-H has low Ca/(Si+Al) ≈ 0.45–0.75. Dense clusters of 2- to 30-µm strätlingite plates further reinforce interfacial zones, the weakest link of modern cement-based concrete, and the cementitious matrix. These crystals formed during long-term autogeneous reaction of dissolved calcite from lime and the alkali-rich scoriae groundmass, clay mineral (halloysite), and zeolite (phillipsite and chabazite) surface textures from the Pozzolane Rosse pyroclastic flow, erupted from the nearby Alban Hills volcano. The clast-supported conglomeratic fabric of the concrete presents further resistance to fracture propagation at the structural scale.« less

Mechanical resilience and cementitious processes in Imperial Roman architectural mortar

PubMed Central

Landis, Eric N.; Brune, Philip F.; Vitti, Massimo; Chen, Heng; Li, Qinfei; Kunz, Martin; Wenk, Hans-Rudolf; Monteiro, Paulo J. M.; Ingraffea, Anthony R.

2014-01-01

The pyroclastic aggregate concrete of Trajan’s Markets (110 CE), now Museo Fori Imperiali in Rome, has absorbed energy from seismic ground shaking and long-term foundation settlement for nearly two millenia while remaining largely intact at the structural scale. The scientific basis of this exceptional service record is explored through computed tomography of fracture surfaces and synchroton X-ray microdiffraction analyses of a reproduction of the standardized hydrated lime–volcanic ash mortar that binds decimeter-sized tuff and brick aggregate in the conglomeratic concrete. The mortar reproduction gains fracture toughness over 180 d through progressive coalescence of calcium–aluminum-silicate–hydrate (C-A-S-H) cementing binder with Ca/(Si+Al) ≈ 0.8–0.9 and crystallization of strätlingite and siliceous hydrogarnet (katoite) at ≥90 d, after pozzolanic consumption of hydrated lime was complete. Platey strätlingite crystals toughen interfacial zones along scoria perimeters and impede macroscale propagation of crack segments. In the 1,900-y-old mortar, C-A-S-H has low Ca/(Si+Al) ≈ 0.45–0.75. Dense clusters of 2- to 30-µm strätlingite plates further reinforce interfacial zones, the weakest link of modern cement-based concrete, and the cementitious matrix. These crystals formed during long-term autogeneous reaction of dissolved calcite from lime and the alkali-rich scoriae groundmass, clay mineral (halloysite), and zeolite (phillipsite and chabazite) surface textures from the Pozzolane Rosse pyroclastic flow, erupted from the nearby Alban Hills volcano. The clast-supported conglomeratic fabric of the concrete presents further resistance to fracture propagation at the structural scale. PMID:25512521

Mathematical Model Relating Uniaxial Compressive Behavior of Manufactured Sand Mortar to MIP-Derived Pore Structure Parameters

PubMed Central

Tian, Zhenghong; Bu, Jingwu

2014-01-01

The uniaxial compression response of manufactured sand mortars proportioned using different water-cement ratio and sand-cement ratio is examined. Pore structure parameters such as porosity, threshold diameter, mean diameter, and total amounts of macropores, as well as shape and size of micropores are quantified by using mercury intrusion porosimetry (MIP) technique. Test results indicate that strains at peak stress and compressive strength decreased with the increasing sand-cement ratio due to insufficient binders to wrap up entire sand. A compression stress-strain model of normal concrete extending to predict the stress-strain relationships of manufactured sand mortar is verified and agreed well with experimental data. Furthermore, the stress-strain model constant is found to be influenced by threshold diameter, mean diameter, shape, and size of micropores. A mathematical model relating stress-strain model constants to the relevant pore structure parameters of manufactured sand mortar is developed. PMID:25133257

Mathematical model relating uniaxial compressive behavior of manufactured sand mortar to MIP-derived pore structure parameters.

PubMed

Tian, Zhenghong; Bu, Jingwu

2014-01-01

The uniaxial compression response of manufactured sand mortars proportioned using different water-cement ratio and sand-cement ratio is examined. Pore structure parameters such as porosity, threshold diameter, mean diameter, and total amounts of macropores, as well as shape and size of micropores are quantified by using mercury intrusion porosimetry (MIP) technique. Test results indicate that strains at peak stress and compressive strength decreased with the increasing sand-cement ratio due to insufficient binders to wrap up entire sand. A compression stress-strain model of normal concrete extending to predict the stress-strain relationships of manufactured sand mortar is verified and agreed well with experimental data. Furthermore, the stress-strain model constant is found to be influenced by threshold diameter, mean diameter, shape, and size of micropores. A mathematical model relating stress-strain model constants to the relevant pore structure parameters of manufactured sand mortar is developed.

Bonding agents for portland cement concrete and mortar.

DOT National Transportation Integrated Search

1983-01-01

Structural repairs of bridge piers and abutements require patching concrete : used depends upon the depth of the patch to be made. In some instances, the : use of a liquid bonding agent has been specified in the mixes as well as in a : grout scrubbed...

The Effect of Graphene Oxide on Cement Mortar

NASA Astrophysics Data System (ADS)

Kjaernsmo, Henrik; Kakay, Samdar; Fossa, Kjell T.; Gronli, John

2018-05-01

This paper investigates the effect of water dispersed- and powder Graphene oxide (GO) nanoparticle on fresh cement mortar, microstructure and mechanical strength after 3,7, and 28 days of curing. These properties were studied by treating the cement mortar with 0.03 wt%, 0.05 wt%, and 0.2 wt% GO of the cement weight combined with 0.8wt % polycarboxylate superplasticizer. The results show that the workability decreases as increasing the content of water dispersed GO. The heat of hydration is increased for both types of GO systems. The percent air content in 0.03 wt% and 0.05 wt% GO is almost constant, but increased from 3.2 % to 4.9 % in 0.2 wt% water dispersed GO. The increased air content has effect on poor compaction and workability. GO has the potential of accelerating the hydration process and enhance the early mechanical strength (3 and 7 days), but the workability seems to diminish the mechanical strength after 28 days of curing, particularly for the highest content of water dispersed GO. No distinct influence of GO on the microstructure. The overall results showed that the impact of water dispersed GO was found out to be higher than the powder GO.

Rapid establishment of a regular distribution of adult tropical Drosophila parasitoids in a multi-patch environment by patch defence behaviour.

PubMed

de Jong, Peter W; Hemerik, Lia; Gort, Gerrit; van Alphen, Jacques J M

2011-01-01

Females of the larval parasitoid of Drosophila, Asobara citri, from sub-Saharan Africa, defend patches with hosts by fighting and chasing conspecific females upon encounter. Females of the closely related, palearctic species Asobara tabida do not defend patches and often search simultaneously in the same patch. The effect of patch defence by A. citri females on their distribution in a multi-patch environment was investigated, and their distributions were compared with those of A. tabida. For both species 20 females were released from two release-points in replicate experiments. Females of A. citri quickly reached a regular distribution across 16 patches, with a small variance/mean ratio per patch. Conversely, A. tabida females initially showed a clumped distribution, and after gradual dispersion, a more Poisson-like distribution across patches resulted (variance/mean ratio was closer to 1 and higher than for A. citri). The dispersion of A. tabida was most probably an effect of exploitation: these parasitoids increasingly made shorter visits to already exploited patches. We briefly discuss hypotheses on the adaptive significance of patch defence behaviour or its absence in the light of differences in the natural history of both parasitoid species, notably the spatial distribution of their hosts.

Brick mortar exposure and chronic lymphocytic leukemia.

PubMed

Markovic-Denic, L; Jankovic, S; Marinkovic, J; Radovanovic, Z

1995-01-01

A case-control study of 130 patients with chronic lymphocytic leukemia (CLL) and 130 controls matched with respect to sex, age (2 years), type of residence (urban-rural) and area of residence (according to the national per capita income) was carried out. Conditional logistic regression analysis showed that, apart of four risk factors already described in the literature (work in a hazardous industry, hair dye use, family history of leukemia and exposure to electromagnetic radiation), brick mortar exposure was also significantly related to CLL.

Physico-chemical characterization of mortars as a tool in studying specific hydraulic components: application to the study of ancient Naxos aqueduct

NASA Astrophysics Data System (ADS)

Maravelaki-Kalaitzaki, P.; Galanos, A.; Doganis, I.; Kallithrakas-Kontos, N.

2011-07-01

Mortars and plasters from the ancient aqueduct on the island of Naxos, Greece, were studied with regard to mineralogical and chemical composition, grain size distribution, raw materials and hydraulic properties, in order to assess their characteristics and design compatible repair mortars. The authentic materials contained lime, crushed-brick, siliceous and calcitic aggregates, in different proportions according to mortar type. Crushed-bricks fired at low temperatures and lightweight volcanic aggregates contained amorphous phases, which upon reaction with lime yielded hydraulic components capable of protecting the construction from the continuous presence of water. Hydraulic calcium silicate/aluminate hydrates, the proportions and the perfect packing of the raw materials, along with the diligent application justify the longevity and durability of the studied samples. The hydraulic properties of samples were pointed out through (a) the well-established CO2/H2O ratio derived from the thermogravimetric analysis and (b) by introducing two powerful indices issued from the chemical analysis, namely CaOhydr and soluble SiO2 hydr. These indices improved the clustering of hydraulic mortars and provided better correlation between mortars, plasters and their binders. By comparing grain size distribution and hydraulicity indices it was possible to distinguish among the construction phases. Based on this study, repair mortars were formulated by hydraulic lime, siliceous sand, calcareous and crushed-brick aggregates, with the optimal water content, ensuring optimum workability and compatible appearance with the authentic ones.

Monitoring corrosion of rebar embedded in mortar using guided ultrasonic waves

NASA Astrophysics Data System (ADS)

Ervin, Benjamin Lee

This thesis investigates the use of guided mechanical waves for monitoring uniform and localized corrosion in steel reinforcing bars embedded in concrete. The main forms of structural deterioration from uniform corrosion in reinforced concrete are the destruction of the bond between steel and concrete, the loss of steel cross-sectional area, and the loss of concrete cross-sectional area from cracking and spalling. Localized corrosion, or pitting, leads to severe loss of steel cross-sectional area, creating a high risk of bar tensile failure and unintended transfer of loads to the surrounding concrete. Reinforcing bars were used to guide the waves, rather than bulk concrete, allowing for longer inspection distances due to lower material absorption, scattering, and divergence. Guided mechanical waves in low frequency ranges (50-200 kHz) and higher frequency ranges (2-8 MHz) were monitored in reinforced mortar specimens undergoing accelerated uniform corrosion. The frequency ranges chosen contain wave modes with varying amounts of interaction, i.e. displacement profile, at the material interface. Lower frequency modes were shown to be sensitive to the accumulation of corrosion product and the level of bond between the surrounding mortar and rebar. This allows for the onset of corrosion and bond deterioration to be monitored. Higher frequency modes were shown to be sensitive to changes in the bar profile surface, allowing for the loss of cross-sectional area to be monitored. Guided mechanical waves in the higher frequency range were also used to monitor reinforced mortar specimens undergoing accelerated localized corrosion. The high frequency modes were sensitive to the localized attack. Also promising was the unique frequency spectrum response for both uniform and localized corrosion, allowing the two corrosion types to be differentiated from through-transmission evaluation. The isolated effects of the reinforcing ribs, simulated debonding, simulated pitting, water

Plastering mortar with antibacterial and antifungal properties studied by 1H NMR relaxometry

NASA Astrophysics Data System (ADS)

Jumate, E.; Aciu, C.; Manea, D. L.; Moldovan, D.; Chelcea, R.; Fechete, R.

2017-12-01

The Plastering mortars, with good antibacterial (in particular Escherichia coli, Staphylococcus aureus, Enterococcus faecalis, Pseudomonas aeruginosa) and antifungal (Aspergillus niger and Penicillium chrysogenum) properties, were studied by 1D NMR relaxometry and internal humidity measurements. Three recipes based on plastering mortar with variable content (0, 5 and 10 %) of Ag/ZnO nanopowders and with adequate physical characteristics regarding the mechanical strengths (CS IV), good adhesion to the substrate and low water absorption by capillarity (W2) were considered. The distributions of transverse relaxation times T2 were measured at 2 h after preparation (for mortar pasta) and then for the same samples at 2, 7, and 28 days during the hydration of mineralogical components. The T2 distributions are characterized by four components associated with hydration water and water in three types of pores of different dimension. The dimension of pores formed during hydration process are strongly dependent on the Ag/ZnO nanopowders content but finally at 28 days the pores distributions, as resulted from the T2 distributions, looks similar. Finally, the transverse relaxation ratio was linearly correlated to the compressive strength and the hydration behaviour during 132 days measured with a dedicated humidity sensor embedded inside sampled was discussed.

Concrete patching guide : final report.

DOT National Transportation Integrated Search

2003-09-01

Maintenance personnel often select a material for patching concrete based on what they have used in the past. However, each patching job has particular demands, which may be different from what was required in past applications. Also, the list of ava...

Research notes : concrete patching guide.

DOT National Transportation Integrated Search

2004-05-01

Maintenance personnel often select a material for patching concrete based on what they have used in the past. However, each patching job has particular demands, which may be different from what was required in past applications. Also, the list of ava...

Comparative study on strength properties of cement mortar by partial replacement of cement with ceramic powder and silica fume

NASA Astrophysics Data System (ADS)

Himabindu, Ch.; Geethasri, Ch.; Hari, N.

2018-05-01

Cement mortar is a mixture of cement and sand. Usage of high amount of cement increases the consumption of natural resources and electric power. To overcome this problem we need to replace cement with some other material. Cement is replaced with many other materials like ceramic powder, silica fume, fly ash, granulated blast furnace slag, metakaolin etc.. In this research cement is replaced with ceramic powder and silica fume. Different combinations of ceramic powder and silica fume in cement were replaced. Cement mortar cubes of 1:3 grade were prepared. These cubes were cured under normal water for 7 days, 14days and 28 days. Compressive strength test was conducted for all mixes of cement mortar cubes.

Updated WORF patch

NASA Image and Video Library

2012-08-16

This patch represents the essential elements associated with pressurized Earth science research aboard the International Space Station. At the top of the patch Klingon script spells out the acronym WORF making reference to the famed Star Trek character of the same name. In doing so it attests to the foresight, honor, integrity, and persistence of all those who made the WORF possible. To the right of the Klingon script is a single four pointed star in the form of a cross to honor the late Dr. Jack Estes and Dr. Dave Amsbury, the individuals most responsible for seeing to it that an optical quality, Earth science research window was added to the United States laboratory module, Destiny. The "flying eyeball" represents the ability of the ISS to allow scientists and astronauts to make and record continuous observations of natural and manmade processes on the surface of the Earth. The Destiny laboratory is depicted on the right of the patch above the Flag of the United States of America and highlights the position of the nadir looking, optical quality, science window in the module. The light emanating from the window from the lighted interior of the module appropriately illuminates the National Ensign for display during both day and night time. In the center of the patch, below the flying eyeball is a graphic representation of the WORF rack. A science instrument is mounted on the WORF payload shelf and is recording data of the Earth's surface through the nadir looking, science window over which the WORF rack is mounted. An astronaut represented by Mario Runco Jr., a designer, developer, and manager of the WORF and depicted as Star Trek's Mr. Spock, is to the left of the WORF rack and is shown in his flight suit with his STS-44 mission patch operating an imaging instrument, emphasizing the importance of astronaut participation to achieve the maximum scientific return from orbital research.

Comparing reliabilities of strip and conventional patch testing.

PubMed

Dickel, Heinrich; Geier, Johannes; Kreft, Burkhard; Pfützner, Wolfgang; Kuss, Oliver

2017-06-01

The standardized protocol for performing the strip patch test has proven to be valid, but evidence on its reliability is still missing. To estimate the parallel-test reliability of the strip patch test as compared with the conventional patch test. In this multicentre, prospective, randomized, investigator-blinded reliability study, 132 subjects were enrolled. Simultaneous duplicate strip and conventional patch tests were performed with the Finn Chambers ® on Scanpor ® tape test system and the patch test preparations nickel sulfate 5% pet., potassium dichromate 0.5% pet., and lanolin alcohol 30% pet. Reliability was estimated by the use of Cohen's kappa coefficient. Parallel-test reliability values of the three standard patch test preparations turned out to be acceptable, with slight advantages for the strip patch test. The differences in reliability were 9% (95%CI: -8% to 26%) for nickel sulfate and 23% (95%CI: -16% to 63%) for potassium dichromate, both favouring the strip patch test. The standardized strip patch test method for the detection of allergic contact sensitization in patients with suspected allergic contact dermatitis is reliable. Its application in routine clinical practice can be recommended, especially if the conventional patch test result is presumably false negative. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Cell-Detection Technique for Automated Patch Clamping

NASA Technical Reports Server (NTRS)

McDowell, Mark; Gray, Elizabeth

2008-01-01

A unique and customizable machinevision and image-data-processing technique has been developed for use in automated identification of cells that are optimal for patch clamping. [Patch clamping (in which patch electrodes are pressed against cell membranes) is an electrophysiological technique widely applied for the study of ion channels, and of membrane proteins that regulate the flow of ions across the membranes. Patch clamping is used in many biological research fields such as neurobiology, pharmacology, and molecular biology.] While there exist several hardware techniques for automated patch clamping of cells, very few of those techniques incorporate machine vision for locating cells that are ideal subjects for patch clamping. In contrast, the present technique is embodied in a machine-vision algorithm that, in practical application, enables the user to identify good and bad cells for patch clamping in an image captured by a charge-coupled-device (CCD) camera attached to a microscope, within a processing time of one second. Hence, the present technique can save time, thereby increasing efficiency and reducing cost. The present technique involves the utilization of cell-feature metrics to accurately make decisions on the degree to which individual cells are "good" or "bad" candidates for patch clamping. These metrics include position coordinates (x,y) in the image plane, major-axis length, minor-axis length, area, elongation, roundness, smoothness, angle of orientation, and degree of inclusion in the field of view. The present technique does not require any special hardware beyond commercially available, off-the-shelf patch-clamping hardware: A standard patchclamping microscope system with an attached CCD camera, a personal computer with an imagedata- processing board, and some experience in utilizing imagedata- processing software are all that are needed. A cell image is first captured by the microscope CCD camera and image-data-processing board, then the image

62. BUILDING NO. 1301, ORDNANCE FACILITY (MORTAR POWDER BUILDING), LOOKING ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

62. BUILDING NO. 1301, ORDNANCE FACILITY (MORTAR POWDER BUILDING), LOOKING AT NORTHWEST FACADE. ACCESS TO ROOF ALLOWS MAINTENANCE OF VENTILATION EQUIPMENT WHICH IS PLACED OUTSIDE BUILDING TO MINIMIZE EXPLOSION HAZARD. NO. 2 VISIBLE ON WALL OF BUILDING STANDS FOR EXPLOSION HAZARD WITH FRAGMENTATION. - Picatinny Arsenal, State Route 15 near I-80, Dover, Morris County, NJ

Global Patch Matching

NASA Astrophysics Data System (ADS)

Huang, X.; Hu, K.; Ling, X.; Zhang, Y.; Lu, Z.; Zhou, G.

2017-09-01

This paper introduces a novel global patch matching method that focuses on how to remove fronto-parallel bias and obtain continuous smooth surfaces with assuming that the scenes covered by stereos are piecewise continuous. Firstly, simple linear iterative cluster method (SLIC) is used to segment the base image into a series of patches. Then, a global energy function, which consists of a data term and a smoothness term, is built on the patches. The data term is the second-order Taylor expansion of correlation coefficients, and the smoothness term is built by combing connectivity constraints and the coplanarity constraints are combined to construct the smoothness term. Finally, the global energy function can be built by combining the data term and the smoothness term. We rewrite the global energy function in a quadratic matrix function, and use least square methods to obtain the optimal solution. Experiments on Adirondack stereo and Motorcycle stereo of Middlebury benchmark show that the proposed method can remove fronto-parallel bias effectively, and produce continuous smooth surfaces.

"Bricks and mortar" self-assembly approach to graphitic mesoporous carbon nanocomposites

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

Fulvio, P. F.; Mayes, R.; Wang, X. Q.

2011-04-20

Mesoporous carbon materials do not have sufficient ordering at the atomic scale to exhibit good electronic conductivity. To date, mesoporous carbons having uniform mesopores and high surface areas have been prepared from partially-graphitizable precursors in the presence of templates. High temperature thermal treatments above 2000 °C, which are usually required to increase conductivity, result in a partial or total collapse of the mesoporous structures and reduced surface areas induced by growth of graphitic domains, limiting their applications in electric double layer capacitors and lithium-ion batteries. In this work, we successfully implemented a “brick-and-mortar” approach to obtain ordered graphitic mesoporous carbonmore » nanocomposites with tunable mesopore sizes below 850 °C without using graphitization catalysts or high temperature thermal treatments. Phenolic resin-based mesoporous carbons act as mortar to highly conductive carbon blacks and carbon onions (bricks). The capacitance and resistivity of final materials can be tailored by changing the mortar to brick ratios.« less

Study on cement mortar and concrete made with sewage sludge ash.

PubMed

Chang, F C; Lin, J D; Tsai, C C; Wang, K S

2010-01-01

This study investigated the feasibility of reusing wastewater sludge ash in construction materials to replace partial materials. Wastewater sludge sampled from thermal power plant was burned into sludge ash at 800°C in the laboratory. The sludge incineration ash has low heavy metal including Pb, Cd, Cr and Cu, so it belongs to general enterprise waste. The chemical composition of sludge incineration ash was summed up in SiO₂, CaO, Fe₂O₃ and MgO. Then the wastewater sludge ash is also found to be a porous material with irregular surface. When the sludge ash was used to replace mortar or concrete cement, its water-adsorption capability will result in the reduction of mortar workability and compressive strength. Cement is being substituted for sludge ash, and 10 percent of sludge ash is more appropriate. Sludge ash is reused to take the place of construction materials and satisfies the requests of standard specification except for higher water absorption.

Experimental analysis of compaction of concrete and mortar

NASA Astrophysics Data System (ADS)

Burlion, Nicolas; Pijaudier-Cabot, Gilles; Dahan, Noël

2001-12-01

Compaction of concrete is physically a collapse of the material porous microstructure. It produces plastic strains in the material and, at the same time, an increase of its bulk modulus. This paper presents two experimental techniques aimed at obtaining the hydrostatic response of concrete and mortar. The first one is a uniaxial confined compression test which is quite simple to implement and allows to reach hydrostatic pressures of about 600 MPa. The specimen size is large enough so that concrete with aggregate sizes up to 16 mm can be tested. The second one is a true hydrostatic test performed on smaller (mortar) specimens. Test results show that the hydrostatic response of the material is elasto-plastic with a stiffening effect on both the tangent and unloading bulk moduli. The magnitude of the irreversible volumetric strains depends on the initial porosity of the material. This porosity can be related in a first approximation to the water/cement ratio. A comparison of the hydrostatic responses obtained from the two testing techniques on the same material show that the hydrostatic response of cementitious materials cannot be uncoupled from the deviatoric response, as opposed to the standard assumption in constitutive relations for metal alloys. This feature should be taken into account in the development of constitutive relations for concrete subjected to high confinement pressures which are needed in the modelling of impact problems.

Micromachined patch-clamp apparatus

DOEpatents

Okandan, Murat

2012-12-04

A micromachined patch-clamp apparatus is disclosed for holding one or more cells and providing electrical, chemical, or mechanical stimulation to the cells during analysis with the patch-clamp technique for studying ion channels in cell membranes. The apparatus formed on a silicon substrate utilizes a lower chamber formed from silicon nitride using surface micromachining and an upper chamber formed from a molded polymer material. An opening in a common wall between the chambers is used to trap and hold a cell for analysis using the patch-clamp technique with sensing electrodes on each side of the cell. Some embodiments of the present invention utilize one or more electrostatic actuators formed on the substrate to provide mechanical stimulation to the cell being analyzed, or to provide information about mechanical movement of the cell in response to electrical or chemical stimulation.

Radioactively contaminated electric arc furnace dust as an addition to the immobilization mortar in low- and medium-activity repositories.

PubMed

Castellote, Marta; Menéndez, Esperanza; Andrade, Carmen; Zuloaga, Pablo; Navarro, Mariano; Ordóñez, Manuel

2004-05-15

Electric arc furnace dust (EAFD), generated by the steel-making industry, is in itself an intrinsic hazardous waste; however, the case may also be that scrap used in the process is accidentally contaminated by radioactive elements such as cesium. In this case the resulting EAFD is to be handled as radioactive waste, being duly confined in low- and medium-activity repositories (LMAR). What this paper studies is the reliability of using this radioactive EAFD as an addition in the immobilization mortar of the containers of the LMAR, that is, from the point of view of the durability. Different mixes of mortar containing different percentages of EAFD have been subjected to flexural and compressive strength, initial and final setting time, XRD study, total porosity and pore size distribution, determination of the chloride diffusion coefficient, dimensional stability tests, hydration heat, workability of the fresh mix, and leaching behavior. What is deduced from the results is that for the conditions used in this research, (cement + sand) can be replaced by EAFD upto a ratio [EAFD/(cement + EAFD)] of 46% in the immobilization mortar of LMAR, apparently without any loss in the long-term durability properties of the mortar.

The central tower of the cathedral of Schleswig - New investigations to understand the alcali-silica reaction of historical mortars

NASA Astrophysics Data System (ADS)

Wedekind, Wanja; Protz, Andreas

2016-04-01

The damaging alcali-silica reaction leads to crack-formation and structural destruction at noumerous, constructed with cement mortar, buildings worldwide. The ASR-reaction causes the expansion of altered aggregates by the formation of a swelling gel. This gel consists of calcium silicate hydrate (C-S-H) that increases in volume with water, which exerts an expansive pressure inside the material. The cathedral of Schleswig is one of the oldest in northern Germany. The first church was built in 985-965. The Romanesque building part was erected around 1180 and the Gothic nave at the end of the 13th century. The central tower was constructed between 1888 and 1894 with brick and cement mortar. With 112 meters, the tower is the second-largest church spire of the country of Schleswig-Holstein in northern Germany. Due to the formation of cracks and damages from 1953 to 1956 first restoration works took place. Further developments of cracks are making restoration necessary again today. For developing a suitable conservation strategy, different investigations were done. The investigation included the determination of the pore space properties, the hygric and thermal dilatation and mercury porosimetry measurements. Furthermore, the application of cathodoluminescence microscopy may give information about the alteration process and microstructures present and reveal the differences between unaltered and altered mortars. An obvious relation between the porosity and the swelling intensity could be detected. Furthermore it becomes apparent, that a clear zonation of the mortar took place. The mortar near the surface is denser with a lower porosity and has a significantly lower swelling or dilatation.

Evaluation of Toluene Adsorption Performance of Mortar Adhesives Using Porous Carbon Material as Adsorbent.

PubMed

Wi, Seunghwan; Chang, Seong Jin; Jeong, Su-Gwang; Lee, Jongki; Kim, Taeyeon; Park, Kyung-Won; Lee, Dong Ryeol; Kim, Sumin

2017-07-26

Porous carbon materials are advantageous in adsorbing pollutants due to their wide range of specific surface areas, pore diameter, and pore volume. Among the porous carbon materials in the current study, expanded graphite, xGnP, xGnP C-300, xGnP C-500, and xGnP C-750 were prepared as adsorbent materials. Brunauer-Emmett-Teller (BET) analysis was conducted to select the adsorbent material through the analysis of the specific surface area, pore size, and pore volume of the prepared porous carbon materials. Morphological analysis using SEM was also performed. The xGnP C-500 as adsorbent material was applied to a mortar adhesive that is widely used in the installation of interior building materials. The toluene adsorption performances of the specimens were evaluated using 20 L small chamber. Furthermore, the performance of the mortar adhesive, as indicated by the shear bond strength, length change rate, and water retention rate, was analyzed according to the required test method specified in the Korean standards. It was confirmed that for the mortar adhesives prepared using the xGnP C-500 as adsorbent material, the toluene adsorption performance was excellent and satisfied the required physical properties.

Evaluation of Toluene Adsorption Performance of Mortar Adhesives Using Porous Carbon Material as Adsorbent

PubMed Central

Chang, Seong Jin; Jeong, Su-Gwang; Lee, Jongki; Kim, Taeyeon; Park, Kyung-Won; Lee, Dong Ryeol; Kim, Sumin

2017-01-01

Porous carbon materials are advantageous in adsorbing pollutants due to their wide range of specific surface areas, pore diameter, and pore volume. Among the porous carbon materials in the current study, expanded graphite, xGnP, xGnP C-300, xGnP C-500, and xGnP C-750 were prepared as adsorbent materials. Brunauer–Emmett–Teller (BET) analysis was conducted to select the adsorbent material through the analysis of the specific surface area, pore size, and pore volume of the prepared porous carbon materials. Morphological analysis using SEM was also performed. The xGnP C-500 as adsorbent material was applied to a mortar adhesive that is widely used in the installation of interior building materials. The toluene adsorption performances of the specimens were evaluated using 20 L small chamber. Furthermore, the performance of the mortar adhesive, as indicated by the shear bond strength, length change rate, and water retention rate, was analyzed according to the required test method specified in the Korean standards. It was confirmed that for the mortar adhesives prepared using the xGnP C-500 as adsorbent material, the toluene adsorption performance was excellent and satisfied the required physical properties. PMID:28773214

Application of Nano-SiO₂ and Nano-Fe₂O₃ for Protection of Steel Rebar in Chloride Contaminated Concrete: Epoxy Nanocomposite Coatings and Nano-Modified Mortars.

PubMed

Nguyen, Tuan Anh; Nguyen, The Huyen; Pham, Thi Lua; Dinh, Thi Mai Thanh Dinh; Thai, Hoang; Shi, Xianming

2017-01-01

The effect of incorporating nanoparticles on the corrosion resistance of epoxy-coated steel in salt contaminated mortars was investigated using potentiodynamic polarization and electrochemical impedance spectroscopy. Researchers conducted electrochemical monitoring of the coated steel embedded in mortar over 100 days of immersion in 0.1 M NaOH solutions. The chloride permeability and microstructure of Portland cement mortar with admixed nano-materials (at 1% by weight of cement) were examined using an electromigration test and field emission scanning electron microscopy (FESEM). Electrochemical monitoring showed that nano Fe₂O₃ improved the corrosion resistance of the coated rebar. The incorporation of a small amount of nano Fe₂O₃ (1% by total weight of resin and hardener) into the epoxy coating reduced the corrosion current of the epoxy-coated steel in chloride-contaminated mortar (0.3% chloride by weight of cement). After 100 days of immersion, the nanoparticles reduced the corrosion current of epoxy-coated steel by a factor of 6. The FESEM test revealed that admixing of nano-materials not only led to denser cement mortar but also changed the morphology of cement hydration products. The test results of compressive strength showed that nanoparticles increased the strength of cement mortar. The electromigration test showed that the incorporation of nanoparticles improved the chloride penetration resistance of the mortar, as indicated by the reduced apparent diffusion coefficients of the chloride anion. When nano-SiO₂ and nano-Fe₂O₃ were admixed into fresh cement mortar at 1% by weight of cement, the value of D(Cl−) was decreased by 83%, from 7.35×10(−11) m²/s (control specimen) to 1.21×10(−11) m²/s and 1.36×10(−11) m²/s, respectively.

Application of nanoindentation testing to study of the interfacial transition zone in steel fiber reinforced mortar

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

Wang Xiaohui; Jacobsen, Stefan; He Jianying

2009-08-15

The characteristics of the profiles of elastic modulus and hardness of the steel fiber-matrix and fiber-matrix-aggregate interfacial zones in steel fiber reinforced mortars have been investigated by using nanoindentation and Scanning Electron Microscopy (SEM), where two sets of parameters, i.e. water/binder ratio and content of silica fume were considered. Different interfacial bond conditions in the interfacial transition zones (ITZ) are discussed. For sample without silica fume, efficient interfacial bonds across the steel fiber-matrix and fiber-matrix-aggregate interfaces are shown in low water/binder ratio mortar; while in high water/binder ratio mortar, due to the discontinuous bleeding voids underneath the fiber, the fiber-matrixmore » bond is not very good. On the other hand, for sample with silica fume, the addition of 10% silica fume leads to no distinct presence of weak ITZ in the steel fiber-matrix interface; but the effect of the silica fume on the steel fiber-matrix-aggregate interfacial zone is not obvious due to voids in the vicinity of steel fiber.« less

Effect of amorphous silica ash used as a partial replacement for cement on the compressive and flexural strengths cement mortar.

NASA Astrophysics Data System (ADS)

Usman, Aliyu; Ibrahim, Muhammad B.; Bala, Nura

2018-04-01

This research is aimed at investigating the effect of using amorphous silica ash (ASA) obtained from rice husk as a partial replacement of ordinary Portland cement (OPC) on the compressive and flexural strength of mortar. ASA was used in partial replacement of ordinary Portland cement in the following percentages 2.5 percent, 5 percent, 7.5 percent and 10 percent. These partial replacements were used to produce Cement-ASA mortar. ASA was found to contain all major chemical compounds found in cement with the exception of alumina, which are SiO2 (91.5%), CaO (2.84%), Fe2O3 (1.96%), and loss on ignition (LOI) was found to be 9.18%. It also contains other minor oxides found in cement. The test on hardened mortar were destructive in nature which include flexural strength test on prismatic beam (40mm x 40mm x 160mm) and compressive strength test on the cube size (40mm x 40mm, by using the auxiliary steel plates) at 2,7,14 and 28 days curing. The Cement-ASA mortar flexural and compressive strengths were found to be increasing with curing time and decreases with cement replacement by ASA. It was observed that 5 percent replacement of cement with ASA attained the highest strength for all the curing ages and all the percentage replacements attained the targeted compressive strength of 6N/mm2 for 28 days for the cement mortar

A search theory model of patch-to-patch forager movement with application to pollinator-mediated gene flow.

PubMed

Hoyle, Martin; Cresswell, James E

2007-09-07

We present a spatially implicit analytical model of forager movement, designed to address a simple scenario common in nature. We assume minimal depression of patch resources, and discrete foraging bouts, during which foragers fill to capacity. The model is particularly suitable for foragers that search systematically, foragers that deplete resources in a patch only incrementally, and for sit-and-wait foragers, where harvesting does not affect the rate of arrival of forage. Drawing on the theory of job search from microeconomics, we estimate the expected number of patches visited as a function of just two variables: the coefficient of variation of the rate of energy gain among patches, and the ratio of the expected time exploiting a randomly chosen patch and the expected time travelling between patches. We then consider the forager as a pollinator and apply our model to estimate gene flow. Under model assumptions, an upper bound for animal-mediated gene flow between natural plant populations is approximately proportional to the probability that the animal rejects a plant population. In addition, an upper bound for animal-mediated gene flow in any animal-pollinated agricultural crop from a genetically modified (GM) to a non-GM field is approximately proportional to the proportion of fields that are GM and the probability that the animal rejects a field.

Mapped Plot Patch Size Estimates

Treesearch

Paul C. Van Deusen

2005-01-01

This paper demonstrates that the mapped plot design is relatively easy to analyze and describes existing formulas for mean and variance estimators. New methods are developed for using mapped plots to estimate average patch size of condition classes. The patch size estimators require assumptions about the shape of the condition class, limiting their utility. They may...

Catch and Patch: A Pipette-Based Approach for Automating Patch Clamp That Enables Cell Selection and Fast Compound Application.

PubMed

Danker, Timm; Braun, Franziska; Silbernagl, Nikole; Guenther, Elke

2016-03-01

Manual patch clamp, the gold standard of electrophysiology, represents a powerful and versatile toolbox to stimulate, modulate, and record ion channel activity from membrane fragments and whole cells. The electrophysiological readout can be combined with fluorescent or optogenetic methods and allows for ultrafast solution exchanges using specialized microfluidic tools. A hallmark of manual patch clamp is the intentional selection of individual cells for recording, often an essential prerequisite to generate meaningful data. So far, available automation solutions rely on random cell usage in the closed environment of a chip and thus sacrifice much of this versatility by design. To parallelize and automate the traditional patch clamp technique while perpetuating the full versatility of the method, we developed an approach to automation, which is based on active cell handling and targeted electrode placement rather than on random processes. This is achieved through an automated pipette positioning system, which guides the tips of recording pipettes with micrometer precision to a microfluidic cell handling device. Using a patch pipette array mounted on a conventional micromanipulator, our automated patch clamp process mimics the original manual patch clamp as closely as possible, yet achieving a configuration where recordings are obtained from many patch electrodes in parallel. In addition, our implementation is extensible by design to allow the easy integration of specialized equipment such as ultrafast compound application tools. The resulting system offers fully automated patch clamp on purposely selected cells and combines high-quality gigaseal recordings with solution switching in the millisecond timescale.

Light transmission and preference of eye patches for occlusion treatment.

PubMed

Heo, Hwan; Park, Jung Won; Park, Sang Woo

2013-01-01

To investigate light transmission and preference for six eye patches for occlusion therapy. Six patches were examined, including; Ortopad Fun Pack, Ortopad Flesh, Kawamoto A-1, Kawamoto A-2, 3M Opticlude, and Everade Eye Guard. The size and the presence of a light blocking pad of patches were investigated. The amount of light transmitted through the patches was evaluated, using a digital light meter and a model eye, in three different environments; indoors with fluorescent light, outdoors on a sunny day, and strong light from illuminator. After patching the normal eye, the flash visual evoked potential (VEP) was measured. Thirty patients with amblyopia or horizontal strabismus, who received occlusion therapy as initial treatment, were included. After using all six patches, patients completed a 7-item questionnaire regarding the patch preference for size, color and shape, adhesive power, pain with removal, skin irritation after removing patch, parent's preference and overall opinion. All patches had a light-blocking pad, except the 3M Nexcare. Ortopad had the strongest light blocking power in the three environments, and the 3M Nexcare had the weakest power. In flash VEP, Ortopad and Kawamoto patches showed flat, but 3M Nexcare and Everade Eye Guard showed normal response. There were significant preferential differences among the patches in all the items of the questionnaire (P<0.05). In comparison between the patches respectively, 3M Nexcare received the lowest satisfaction in pain when removing a patch and skin irritation after removing a patch. Kawamoto A-2 received the lowest score in the overall satisfaction. We found differences in the light-blocking power and in the preference of the various patches for the occlusion treatment. This is a pilot study regarding only characteristics and preferences of patches. Further clinical studies regarding the relationship between characteristics or preferences of patches and outcomes of occlusion treatment are needed.

Multi-objective design optimization of antenna structures using sequential domain patching with automated patch size determination

NASA Astrophysics Data System (ADS)

Koziel, Slawomir; Bekasiewicz, Adrian

2018-02-01

In this article, a simple yet efficient and reliable technique for fully automated multi-objective design optimization of antenna structures using sequential domain patching (SDP) is discussed. The optimization procedure according to SDP is a two-step process: (i) obtaining the initial set of Pareto-optimal designs representing the best possible trade-offs between considered conflicting objectives, and (ii) Pareto set refinement for yielding the optimal designs at the high-fidelity electromagnetic (EM) simulation model level. For the sake of computational efficiency, the first step is realized at the level of a low-fidelity (coarse-discretization) EM model by sequential construction and relocation of small design space segments (patches) in order to create a path connecting the extreme Pareto front designs obtained beforehand. The second stage involves response correction techniques and local response surface approximation models constructed by reusing EM simulation data acquired in the first step. A major contribution of this work is an automated procedure for determining the patch dimensions. It allows for appropriate selection of the number of patches for each geometry variable so as to ensure reliability of the optimization process while maintaining its low cost. The importance of this procedure is demonstrated by comparing it with uniform patch dimensions.

Pharmacokinetic Evaluation of Two Nicotine Patches in Smokers.

PubMed

Rasmussen, Scott; Horkan, Kathleen Halabuk; Kotler, Mitchell

2018-02-02

Smoking continues to be a major preventable cause of early mortality worldwide, and nicotine replacement therapy has been demonstrated to increase rates of abstinence among smokers attempting to quit. Nicotine transdermal systems (also known as nicotine patches) attach to the skin via an adhesive layer composed of a mixture of different-molecular-weight polyisobutylenes (PIBs) in a specific ratio. This randomized, single-dose, 2-treatment, crossover pharmacokinetic (PK) trial assessed the bioequivalence of nicotine patches including a replacement PIB adhesive (test) compared with the PIB adhesive historically used on marketed patches (reference). The test and reference patches were bioequivalent, as determined by the PK parameters of C max and AUC 0-t . In addition, the parameters T max and t 1/2 did not significantly differ between the 2 patches, supporting the bioequivalence finding from the primary analysis. The tolerability profiles of the patches containing the replacement and previously used PIB adhesives were similar; application-site adverse events did not significantly differ between test and reference patches. Overall, these data establish the bioequivalence of the nicotine patch with the replacement PIB adhesive formulation and the previously utilized PIB adhesive formulation. © 2018 The Authors. Clinical Pharmacology in Drug Development published by Wiley Periodicals, Inc. on behalf of The American College of Clinical Pharmacology.

The patch distributed producer-scrounger game.

PubMed

Ohtsuka, Yasunori; Toquenaga, Yukihiko

2009-09-21

Grouping in animals is ubiquitous and thought to provide group members antipredatory advantages and foraging efficiency. However, parasitic foraging strategy often emerges in a group. The optimal parasitic policy has given rise to the producer-scrounger (PS) game model, in which producers search for food patches, and scroungers parasitize the discovered patches. The N-persons PS game model constructed by Vickery et al. (1991. Producers, scroungers, and group foraging. American Naturalist 137, 847-863) predicts the evolutionarily stable strategy (ESS) of frequency of producers (q;) that depends on the advantage of producers and the number of foragers in a group. However, the model assumes that the number of discovered patches in one time unit never exceeds one. In reality, multiple patches could be found in one time unit. In the present study, we relax this assumption and assumed that the number of discovered patches depends on the producers' variable encounter rate with patches (lambda). We show that q; strongly depends on lambda within a feasible range, although it still depends on the advantage of producer and the number of foragers in a group. The basic idea of PS game is the same as the information sharing (parasitism), because scroungers are also thought to parasitize informations of locations of food patches. Horn (1968) indicated the role of information-parasitism in animal aggregation (Horn, H.S., 1968. The adaptive significance of colonial nesting in the Brewer's blackbird (euphagus cyanocephalus). Ecology 49, 682-646). Our modified PS game model shows the same prediction as the Horn's graphical animal aggregation model; the proportion of scroungers will increase or animals should adopt colonial foraging when resource is spatiotemporally clumped, but scroungers will decrease or animals should adopt territorial foraging if the resource is evenly distributed.

Evaluation of concrete pavement patching techniques.

DOT National Transportation Integrated Search

1989-01-01

This final report presents the results of a study undertaken to improve in concrete pavement patching techniques. Activities included an evaluation of the suitability of the impact hammer and maturity calculations for determining when a patch is read...

Habitat quality and geometry affect patch occupancy of two Orthopteran species.

PubMed

Pasinelli, Gilberto; Meichtry-Stier, Kim; Birrer, Simon; Baur, Bruno; Duss, Martin

2013-01-01

Impacts of habitat loss and fragmentation on distribution and population size of many taxa are well established. In contrast, less is known about the role of within-patch habitat quality for the spatial dynamics of species, even though within-patch habitat quality may substantially influence the dynamics of population networks. We studied occurrence patterns of two Orthopteran species in relation to size, isolation and quality of habitat patches in an intensively managed agricultural landscape (16.65 km(2)) in the Swiss lowland. Occurrence of field crickets (Gryllus campestris) was positively related to patch size and negatively to the distance to the nearest occupied patch, two measures of patch geometry. Moreover, field crickets were more likely to occur in extensively managed meadows, meadows used at low intensity and meadows dominated by Poa pratensis, three measures of patch quality. Occurrence of the large gold grasshopper (Chrysochraon dispar) was negatively related to two measures of patch geometry, distance to the nearest occupied patch and perimeter index (ratio of perimeter length to patch area). Further, large gold grasshoppers were more likely to occupy patches close to water and patches with vegetation left uncut over winter, two measures of patch quality. Finally, examination of patch occupancy dynamics of field crickets revealed that patches colonized in 2009 and patches occupied in both 2005 and 2009 were larger, better connected and of other quality than patches remaining unoccupied and patches from which the species disappeared. The strong relationships between Orthopteran occurrence and aspects of patch geometry found in this study support the "area-and-isolation paradigm". Additionally, our study reveals the importance of patch quality for occurrence patterns of both species, and for patch occupancy dynamics in the field cricket. An increased understanding of patch occupancy patterns may be gained if inference is based on variables related to

The Effect of Sodium Hydroxide Molarity on Strength Development of Non-Cement Class C Fly Ash Geopolymer Mortar

NASA Astrophysics Data System (ADS)

Wardhono, A.

2018-01-01

The use of fly ash as cement replacement material can overcome the environmental issues, especially the global warming problem caused by the greenhouse effect. This is attributed to the CO2 gas produced during the cement manufacturing process, which 1 ton of cement is equivalent to 1 ton CO2. However, the major problem of fly ash is the requirement of activators to activate the polymer reactions. The most common activator used in non-cement or geopolymer material is the combination of sodium hydroxide (NaOH) and sodium silicate. This study aims to identify the effect of NaOH molarity as activator on strength development of non-cement class C fly ash geopolymer mortar. The molarity variations of NaOH were 6 Molar (M), 8M, 10M, 12M, 14M and 15M. The compressive strength test was performed at the age of 3, 7 and 28 days in accordance with ASTM standard, and the specimens were cured at room temperature. The results show that the highest compressive strength was achieved by geopolymer mortar with a molarity of 12M. It exhibits a higher strength to that normal mortar at 28 days. However, the use of NaOH molarity more than 12M tends to decrease the strength of non-cement geopolymer mortar specimens.

Macronutrient balancing affects patch departure by guerezas (Colobus guereza).

PubMed

Johnson, Caley A; Raubenheimer, David; Chapman, Colin A; Tombak, Kaia J; Reid, Andrea J; Rothman, Jessica M

2017-04-01

Foraging strategies are central in shaping social structure and grouping patterns in primates. We address Colobus guereza foraging strategies by investigating their patch departure decisions in relation to diet composition and nutrition. We examine whether guerezas are constrained in their intake of food in patches and thereby forage according to a fixed amount strategy that dictates patch departure. Additionally, we assess whether guereza employ a fixed time strategy or attempt to balance nutrients when foraging. We measured food patch occupancy time, intake rates, and analyzed foods for macronutrients, fiber, and condensed tannins. We determined that guerezas do not employ a fixed time foraging strategy; patch residence time varied widely between 1 and 290 min. They also did not depart patches or stop eating when they reached a specific intake of dry mass, macronutrients, or condensed tannins. However, guerezas maintained a macronutrient balance when feeding across patches, and the balance of protein to non-protein energy (fats and carbohydrates) in patches is the best indicator of time adult guerezas spent feeding in patches. Previous studies have shown that the protein-to-fiber ratio is important in predicting food selection for folivores and their biomass; however, we found that guerezas did not maximize protein and minimize fiber intake while foraging in patches, nor did they stay longer in patches with the highest ratio of protein to fiber concentrations. This study raises questions about the nutritional and social implications of patch depletion as a foraging strategy in folivorous monkeys where food limitation predicts competitive and social regimes. Am. J. Primatol. 79:e22495, 2017. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

Compressive and flexural strength of high strength phase change mortar

NASA Astrophysics Data System (ADS)

Qiao, Qingyao; Fang, Changle

2018-04-01

High-strength cement produces a lot of hydration heat when hydrated, it will usually lead to thermal cracks. Phase change materials (PCM) are very potential thermal storage materials. Utilize PCM can help reduce the hydration heat. Research shows that apply suitable amount of PCM has a significant effect on improving the compressive strength of cement mortar, and can also improve the flexural strength to some extent.

Transparent, Ultrahigh-Gas-Barrier Films with a Brick-Mortar-Sand Structure.

PubMed

Dou, Yibo; Pan, Ting; Xu, Simin; Yan, Hong; Han, Jingbin; Wei, Min; Evans, David G; Duan, Xue

2015-08-10

Transparent and flexible gas-barrier materials have shown broad applications in electronics, food, and pharmaceutical preservation. Herein, we report ultrahigh-gas-barrier films with a brick-mortar-sand structure fabricated by layer-by-layer (LBL) assembly of XAl-layered double hydroxide (LDH, X=Mg, Ni, Zn, Co) nanoplatelets and polyacrylic acid (PAA) followed by CO2 infilling, denoted as (XAl-LDH/PAA)n-CO2. The near-perfectly parallel orientation of the LDH "brick" creates a long diffusion length to hinder the transmission of gas molecules in the PAA "mortar". Most significantly, both the experimental studies and theoretical simulations reveal that the chemically adsorbed CO2 acts like "sand" to fill the free volume at the organic-inorganic interface, which further depresses the diffusion of permeating gas. The strategy presented here provides a new insight into the perception of barrier mechanism, and the (XAl-LDH/PAA)n-CO2 film is among the best gas barrier films ever reported. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Solid state NMR and LVSEM studies on the hardening of latex modified tile mortar systems

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

Rottstegge, J.; Arnold, M.; Herschke, L.

Construction mortars contain a broad variety of both inorganic and organic additives beside the cement powder. Here we present a study of tile mortar systems based on portland cement, quartz, methyl cellulose and different latex additives. As known, the methyl cellulose stabilizes the freshly prepared cement paste, the latex additive enhances final hydrophobicity, flexibility and adhesion. Measurements were performed by solid state nuclear magnetic resonance (NMR) and low voltage scanning electron microscopy (LVSEM) to probe the influence of the latex additives on the hydration, hardening and the final tile mortar properties. While solid state NMR enables monitoring of the bulkmore » composition, scanning electron microscopy affords visualization of particles and textures with respect to their shape and the distribution of the different phases. Within the alkaline cement paste, the poly(vinyl acetate) (VAc)-based latex dispersions stabilized by poly(vinyl alcohol) (PVA) were found to be relatively stable against hydrolysis. The influence of the combined organic additives methyl cellulose, poly(vinyl alcohol) and latexes stabilized by poly(vinyl alcohol) on the final silicate structure of the cement hydration products is small. But even small amounts of additives result in an increased ratio of ettringite to monosulfate within the final hydrated tile mortar as monitored by {sup 27}Al NMR. The latex was found to be adsorbed to the inorganic surfaces, acting as glue to the inorganic components. For similar latex water interfaces built up by poly(vinyl alcohol), a variation in the latex polymer composition results in modified organic textures. In addition to the networks of the inorganic cement and of the latex, there is a weak network build up by thin polymer fibers, most probably originating from poly(vinyl alcohol). Besides the weak network, polymer fibers form well-ordered textures covering inorganic crystals such as portlandite.« less

Application of a semi-empirical model for the evaluation of transmission properties of barite mortar.

PubMed

Santos, Josilene C; Tomal, Alessandra; Mariano, Leandro; Costa, Paulo R

2015-06-01

The aim of this study was to estimate barite mortar attenuation curves using X-ray spectra weighted by a workload distribution. A semi-empirical model was used for the evaluation of transmission properties of this material. Since ambient dose equivalent, H(⁎)(10), is the radiation quantity adopted by IAEA for dose assessment, the variation of the H(⁎)(10) as a function of barite mortar thickness was calculated using primary experimental spectra. A CdTe detector was used for the measurement of these spectra. The resulting spectra were adopted for estimating the optimized thickness of protective barrier needed for shielding an area in an X-ray imaging facility. Copyright © 2015 Elsevier Ltd. All rights reserved.

The effect of altitude, patch size and disturbance on species richness and density of lianas in montane forest patches

NASA Astrophysics Data System (ADS)

Mohandass, Dharmalingam; Campbell, Mason J.; Hughes, Alice C.; Mammides, Christos; Davidar, Priya

2017-08-01

The species richness and density of lianas (woody vines) in tropical forests is determined by various abiotic and biotic factors. Factors such as altitude, forest patch size and the degree of forest disturbance are known to exert strong influences on liana species richness and density. We investigated how liana species richness and density were concurrently influenced by altitude (1700-2360 m), forest patch size, forest patch location (edge or interior) and disturbance intensity in the tropical montane evergreen forests, of the Nilgiri and Palni hills, Western Ghats, southern India. All woody lianas (≥1 cm dbh) were enumerated in plots of 30 × 30 m in small, medium and large forest patches, which were located along an altitudinal gradient ranging from 1700 to 2360 m. A total of 1980 individual lianas were recorded, belonging to 45 species, 32 genera and 21 families, from a total sampling area of 13.86 ha (across 154 plots). Liana species richness and density decreased significantly with increasing altitude and increased with increasing forest patch size. Within forest patches, the proportion of forest edge or interior habitat influenced liana distribution and succession especially when compared across the patch size categories. Liana species richness and density also varied along the altitudinal gradient when examined using eco-physiological guilds (i.e. shade tolerance, dispersal mode and climbing mechanism). The species richness and density of lianas within these ecological guilds responded negatively to increasing altitude and positively to increasing patch size and additionally displayed differing sensitivities to forest disturbance. Importantly, the degree of forest disturbance significantly altered the relationship between liana species richness and density to increasing altitude and patches size, and as such is likely the primary influence on liana response to montane forest succession. Our findings suggest that managing forest disturbance in the examined

Broadband Circularly Polarized Patch Antenna and Method

DTIC Science & Technology

2016-09-16

300152 1 of 14 BROADBAND CIRCULARLY POLARIZED PATCH ANTENNA AND METHOD STATEMENT OF GOVERNMENT INTEREST [0001] The invention described herein may...present invention provides a method and apparatus for a broadband circularly polarized patch antenna . (2) Description of the Prior Art [0004] A...patch antenna , also referred to as a microstrip antenna , is a type of radio antenna with a low profile that can be mounted on a flat surface. The

Compliance and patching and atropine amblyopia treatments.

PubMed

Wang, Jingyun

2015-09-01

In the past 20 years, there has been a great advancement in knowledge pertaining to compliance with amblyopia treatments. The occlusion dose monitor introduced quantitative monitoring methods in patching, which sparked our initial understanding of the dose-response relationship for patching amblyopia treatment. This review focuses on current compliance knowledge and the impact it has on patching and atropine amblyopia treatment. Copyright © 2015 Elsevier Ltd. All rights reserved.

Recycled Glass Fiber Reinforced Polymer Composites Incorporated in Mortar for Improved Mechanical Performance

DOT National Transportation Integrated Search

2017-12-11

Glass fiber reinforced polymer (GFRP) recycled from retired wind turbines was implemented in mortar as a volumetric replacement of sand during the two phases of this study. In Phase I, the mechanically refined GFRP particle sizes were sieved for four...

Scattering from arbitrarily shaped microstrip patch antennas

NASA Technical Reports Server (NTRS)

Shively, David G.; Deshpande, Manohar D.; Cockrell, Capers R.

1992-01-01

The scattering properties of arbitrarily shaped microstrip patch antennas are examined. The electric field integral equation for a current element on a grounded dielectric slab is developed for a rectangular geometry based on Galerkin's technique with subdomain rooftop basis functions. A shape function is introduced that allows a rectangular grid approximation to the arbitrarily shaped patch. The incident field on the patch is expressed as a function of incidence angle theta(i), phi(i). The resulting system of equations is then solved for the unknown current modes on the patch, and the electromagnetic scattering is calculated for a given angle. Comparisons are made with other calculated results as well as with measurements.

Transdermal nicotine patches for eosinophilic pustular folliculitis.

PubMed

Yoshifuku, Asuka; Higashi, Yuko; Matsushita, Shigeto; Kawai, Kazuhiro; Kanekura, Takuro

2013-09-01

We previously reported the clinical effectiveness of transdermal nicotine patches for the treatment of skin disorders with eosinophilic infiltration such as Kimura's disease, erythema nodosum and eosinophilic pustular folliculitis (EPF). We assessed the efficacy and safety of transdermal nicotine patches for EPF. We treated eight patients with EPF with transdermal nicotine patches and evaluated the treatment response by performing overall lesional assessment. Excellent 77and good responses were obtained in five and one patient(s), respectively. In the other two patients, the lesions remained unchanged. No severe adverse effects were observed. Our results suggest that transdermal nicotine patches may be useful and safe in the treatment of EPF. © 2013 Japanese Dermatological Association.

Research on Performance and Microstructure of Sewage Pipe Mortar Strengthened with Different Anti-Corrosion Technologies

NASA Astrophysics Data System (ADS)

Mu, Song; Zhou, Huaxin; Shi, Liang; Liu, Jianzhong; Cai, Jingshun; Wang, Feng

2017-10-01

Mostly urban underground sewage is the acidic corrosion environment with a high concentration of aggressive ions and microbe, which resulted in performance deterioration and service-life decrease of sewage concrete pipe. In order to effectively protect durability of the concrete pipe, the present paper briefly analysed the main degradation mechanism of concrete pipe attacked by urban underground sewage, and proposed that using penetrating and strengthening surface sealer based on inorganic chemistry. In addition, using index of compressive strength, weight loss and appearance level to investigate the influence of the sealer on corrosion resistance of mortar samples after different dry-wet cycles. Besides, comparative research on effect of the sealer, aluminate cement and admixture of corrosion resistance was also addressed. At last, the SEM technology was used to reveal the improvement mechanism of different technologies of corrosion resistance. The results indicated that the sealer and aluminate cement can significantly improve corrosion resistance of mortar. Besides, the improvement effect can be described as the descending order: the penetrating and strengthening surface sealer > aluminate cement > admixture of corrosion resistance. The mortar sample treated with the sealer displayed the condensed and sound microstructure which proved that the sealer can improve the corrosion resistance to urban underground sewage.

Immunoisolation Patch System for Cellular Transplantation

NASA Technical Reports Server (NTRS)

Wang, Taylor G. (Inventor)

2014-01-01

An immunoisolation patch system, and particularly a patch system comprising multiple immunoisolation microcapsules, each encapsulating biological material such as cells for transplantation, which can be used in the prophylactic and therapeutic treatment of disease in large animals and humans without the need for immunosuppression.

Social Familiarity Governs Prey Patch-Exploitation, - Leaving and Inter-Patch Distribution of the Group-Living Predatory Mite Phytoseiulus persimilis

PubMed Central

Zach, Gernot J.; Peneder, Stefan; Strodl, Markus A.; Schausberger, Peter

2012-01-01

Background In group-living animals, social interactions and their effects on other life activities such as foraging are commonly determined by discrimination among group members. Accordingly, many group-living species evolved sophisticated social recognition abilities such as the ability to recognize familiar individuals, i.e. individuals encountered before. Social familiarity may affect within-group interactions and between-group movements. In environments with patchily distributed prey, group-living predators must repeatedly decide whether to stay with the group in a given prey patch or to leave and search for new prey patches and groups. Methodology/Principal Findings Based on the assumption that in group-living animals social familiarity allows to optimize the performance in other tasks, as for example predicted by limited attention theory, we assessed the influence of social familiarity on prey patch exploitation, patch-leaving, and inter-patch distribution of the group-living, plant-inhabiting predatory mite Phytoseiulus persimilis. P. persimilis is highly specialized on herbivorous spider mite prey such as the two-spotted spider mite Tetranychus urticae, which is patchily distributed on its host plants. We conducted two experiments with (1) groups of juvenile P. persimilis under limited food on interconnected detached leaflets, and (2) groups of adult P. persimilis females under limited food on whole plants. Familiar individuals of both juvenile and adult predator groups were more exploratory and dispersed earlier from a given spider mite patch, occupied more leaves and depleted prey more quickly than individuals of unfamiliar groups. Moreover, familiar juvenile predators had higher survival chances than unfamiliar juveniles. Conclusions/Significance We argue that patch-exploitation and -leaving, and inter-patch dispersion were more favorably coordinated in groups of familiar than unfamiliar predators, alleviating intraspecific competition and improving prey

Social familiarity governs prey patch-exploitation, -leaving and inter-patch distribution of the group-living predatory mite Phytoseiulus persimilis.

PubMed

Zach, Gernot J; Peneder, Stefan; Strodl, Markus A; Schausberger, Peter

2012-01-01

In group-living animals, social interactions and their effects on other life activities such as foraging are commonly determined by discrimination among group members. Accordingly, many group-living species evolved sophisticated social recognition abilities such as the ability to recognize familiar individuals, i.e. individuals encountered before. Social familiarity may affect within-group interactions and between-group movements. In environments with patchily distributed prey, group-living predators must repeatedly decide whether to stay with the group in a given prey patch or to leave and search for new prey patches and groups. Based on the assumption that in group-living animals social familiarity allows to optimize the performance in other tasks, as for example predicted by limited attention theory, we assessed the influence of social familiarity on prey patch exploitation, patch-leaving, and inter-patch distribution of the group-living, plant-inhabiting predatory mite Phytoseiulus persimilis. P. persimilis is highly specialized on herbivorous spider mite prey such as the two-spotted spider mite Tetranychus urticae, which is patchily distributed on its host plants. We conducted two experiments with (1) groups of juvenile P. persimilis under limited food on interconnected detached leaflets, and (2) groups of adult P. persimilis females under limited food on whole plants. Familiar individuals of both juvenile and adult predator groups were more exploratory and dispersed earlier from a given spider mite patch, occupied more leaves and depleted prey more quickly than individuals of unfamiliar groups. Moreover, familiar juvenile predators had higher survival chances than unfamiliar juveniles. We argue that patch-exploitation and -leaving, and inter-patch dispersion were more favorably coordinated in groups of familiar than unfamiliar predators, alleviating intraspecific competition and improving prey utilization and suppression.

Perturbation analysis for patch occupancy dynamics

USGS Publications Warehouse

Martin, Julien; Nichols, James D.; McIntyre, Carol L.; Ferraz, Goncalo; Hines, James E.

2009-01-01

Perturbation analysis is a powerful tool to study population and community dynamics. This article describes expressions for sensitivity metrics reflecting changes in equilibrium occupancy resulting from small changes in the vital rates of patch occupancy dynamics (i.e., probabilities of local patch colonization and extinction). We illustrate our approach with a case study of occupancy dynamics of Golden Eagle (Aquila chrysaetos) nesting territories. Examination of the hypothesis of system equilibrium suggests that the system satisfies equilibrium conditions. Estimates of vital rates obtained using patch occupancy models are used to estimate equilibrium patch occupancy of eagles. We then compute estimates of sensitivity metrics and discuss their implications for eagle population ecology and management. Finally, we discuss the intuition underlying our sensitivity metrics and then provide examples of ecological questions that can be addressed using perturbation analyses. For instance, the sensitivity metrics lead to predictions about the relative importance of local colonization and local extinction probabilities in influencing equilibrium occupancy for rare and common species.

Characterization of solidified radioactive waste due to the incorporation of high- and low-density polyethylene granules and titanium dioxide in mortar matrices

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

Peric, A.

1997-12-31

The rutile form of titanium dioxide and granules of high density polyethylene (PEHD) and low density polyethylene (PELD) were used to prepare mortar matrices for immobilization of radioactive waste materials containing {sup 137}Cs. PELD, PEHD and TiO{sub 2} were added to mortar matrix preparations with the objective of improving physico-chemical characteristics of the radwaste-mortar matrix mixtures, in particular the leach-rate of the immobilized radionuclide. One type of PELD and two types of PEHD were used to replace 50 wt.% of stone granules normally used in the matrix, in order to decrease the porosity and density of the mortar matrix andmore » to avoid segregation of the stone particles at the bottom of the immobilized radioactive waste cylindrical form. TiO{sub 2} was also added to the mortar formulation, replacing 5 and 8 wt.% of the total cement weight. Cured samples were investigated under temperature stress conditions, where the temperature extremes were: T{sub min} = {minus}20 C, T{sub max} = +70 C. Samples were periodically immersed in distilled water at the ambient room temperature, after each freezing and heating treatment. Results of accelerated leaching experiments for these samples and samples prepared exclusively with polyethylenes replacing 100% of the stone granules and TiO{sub 2}, treated in nonaccelerated leaching experiments, were compared. Even using an accelerated ageing leach test that overestimates {sup 137}Cs leach rates, it can be deduced, that radionuclide leach rates from the radioactive waste mortar mixture forms were improved. Leach rates decreased from 5%, for the material prepared with stone aggregate, to 3.1 to 4.0%, for the materials prepared solely with PEHD, PELD or TiO{sub 2}, and to about 3% for all six types of the TiO{sub 2}-PEHD and TiO{sub 2}-PELD mixtures tested.« less

Adolescents' experiences using the contraceptive patch versus pills.

PubMed

Sucato, Gina S; Land, Stephanie R; Murray, Pamela J; Cecchini, Reena; Gold, Melanie A

2011-08-01

To compare use of the weekly transdermal contraceptive patch (patch) with daily combined hormonal contraceptive pills (pills) in adolescents. Prospective longitudinal study of adolescents' self-selected (non-randomized) use of the patch or pills. Urban, university hospital-affiliated, adolescent outpatient clinic. 13-22-year-old female adolescents seeking hormonal contraception, 40 who chose the patch and 40 who chose pills. Data were collected via self-report on paper questionnaires at three-cycle intervals for a total of up to nine cycles. Method continuation, perfect use, method satisfaction, quality of life, and side effects, including menstrual changes and perceived mood changes. After nine cycles, 38% of patch users and 60% of pill users were still using the method they had chosen at enrollment. There were no significant differences between the groups in self-reported perfect use. No differences were found in quality of life or side effects. Both patch and pill users noted menses became lighter and more predictable and reported decreased depression prior to their menses; only the pill group reported improvement in premenstrual anger. Method satisfaction was similar in both groups except patch users were more likely to report that their contraceptive method improved normal daily activities. Despite apparent advantages of the patch over the pill, adolescents using both methods continue to face challenges achieving perfect and sustained contraceptive use. 2011 North American Society for Pediatric and Adolescent Gynecology. Published by Elsevier Inc. All rights reserved.

Behavior of fiber reinforced mortar joints in masonry walls subjected to in-plane shear and out-of-plane bending

NASA Astrophysics Data System (ADS)

Armwood, Catherine K.

In this project, 26 fiber-reinforced mortar (FRM) mixtures are evaluated for their workability and strength characteristics. The specimens tested include two control mixtures and 24 FRMs. The mixtures were made of two types of binders; Type N Portland cement lime (Type N-PCL) and Natural Hydrated Lime 5 (NHL5); and 6 fiber types (5 synthetic fibers and one organic). When tested in flexure, the results indicate that majority of the synthetic fiber mixtures enhanced the performance of the mortar and the nano-nylon and horse hair fibers were the least effective in improving the mortar's modulus of rupture, ductility, and energy absorption. Four FRMs that improved the mortar's mechanical properties most during the flexural strength test were then used to conduct additional experiments. The FRM's compressive strength, as well as flexural and shear bond strength with clay and concrete masonry units were determined. Those four mixtures included Type N-PCL as the binder and 4 synthetic fibers. They were evaluated at a standard laboratory flow rate of 110% +/- 5% and a practical field flow rate of 130% +/- 5%. Results indicate that the use of fibers decreases the compressive strength of the mortar most of the time. However, the bond strength test results were promising: 81% of the FRM mixtures increased the flexural bond strength of the prism. The mixtures at 110 +/- 5% flow rate bonded better with concrete bricks and those ate 130+/-5% flow rate bonded better with clay bricks. The results of the shear bond strength show 50% of the FRM mixtures improved the shear bond strength. The FRM mixtures at 110+/-5% flow rate bonded with clay units provided the most improvement in shear bond strength compared to control specimen results. Along with detailed discussions and derived conclusions of these experiments, this dissertation includes recommendations for the most feasible FRM for different applications.

Boolean Operations with Prism Algebraic Patches

PubMed Central

Bajaj, Chandrajit; Paoluzzi, Alberto; Portuesi, Simone; Lei, Na; Zhao, Wenqi

2009-01-01

In this paper we discuss a symbolic-numeric algorithm for Boolean operations, closed in the algebra of curved polyhedra whose boundary is triangulated with algebraic patches (A-patches). This approach uses a linear polyhedron as a first approximation of both the arguments and the result. On each triangle of a boundary representation of such linear approximation, a piecewise cubic algebraic interpolant is built, using a C1-continuous prism algebraic patch (prism A-patch) that interpolates the three triangle vertices, with given normal vectors. The boundary representation only stores the vertices of the initial triangulation and their external vertex normals. In order to represent also flat and/or sharp local features, the corresponding normal-per-face and/or normal-per-edge may be also given, respectively. The topology is described by storing, for each curved triangle, the two triples of pointers to incident vertices and to adjacent triangles. For each triangle, a scaffolding prism is built, produced by its extreme vertices and normals, which provides a containment volume for the curved interpolating A-patch. When looking for the result of a regularized Boolean operation, the 0-set of a tri-variate polynomial within each such prism is generated, and intersected with the analogous 0-sets of the other curved polyhedron, when two prisms have non-empty intersection. The intersection curves of the boundaries are traced and used to decompose each boundary into the 3 standard classes of subpatches, denoted in, out and on. While tracing the intersection curves, the locally refined triangulation of intersecting patches is produced, and added to the boundary representation. PMID:21516262

Smart patch piezoceramic actuator issues

NASA Technical Reports Server (NTRS)

Griffin, Steven F.; Denoyer, Keith K.; Yost, Brad

1993-01-01

The Phillips Laboratory is undertaking the challenge of finding new and innovative ways to integrate sensing, actuation, and the supporting control and power electronics into a compact self-contained unit to provide vibration suppression for a host structure. This self-contained unit is commonly referred to as a smart patch. The interfaces to the smart patch will be limited to standard spacecraft power and possibly a communications line. The effort to develop a smart patch involves both contractual and inhouse programs which are currently focused on miniaturization of the electronics associated with vibrational control using piezoceramic sensors and actuators. This paper is comprised of two distinct parts. The first part examines issues associated with bonding piezoceramic actuators to a host structure. Experimental data from several specimens with varying flexural stiffness are compared to predictions from two piezoelectric/substructure coupling models, the Blocked Force Model and the Uniform Strain Model with Perfect Bonding. The second part of the paper highlights a demonstration article smart patch created using the insights gained from inhouse efforts at the Phillips Laboratory. This demonstration article has self contained electronics on the same order of size as the actuator powered by a voltage differential of approximately 32 volts. This voltage is provided by four rechargeable 8 volt batteries.

A pliable electroporation patch (ep-Patch) for efficient delivery of nucleic acid molecules into animal tissues with irregular surface shapes.

PubMed

Wei, Zewen; Huang, Yuanyu; Zhao, Deyao; Hu, Zhiyuan; Li, Zhihong; Liang, Zicai

2015-01-05

Delivery of nucleic acids into animal tissues by electroporation is an appealing approach for various types of gene therapy, but efficiency of existing methodsis not satisfactory. Here we present the validation of novel electroporation patch (ep-Patch) for efficient delivery of DNA and siRNA into mouse tissues. Using micromachining technology, closely spaced gold electrodes were made on the pliable parylene substrate to form a patch-like electroporation metrics. It enabled large coverage of the target tissues and close surface contact between the tissues and electrodes, thus providing a uniform electric field to deliver nucleic acids into tissues, even beneath intact skin. Using this ep-Patch for efficiently delivery of both DNA and siRNA, non-invasive electroporation of healthy mouse muscle tissue was successfully achieved. Delivery of these nucleic acids was performed to intact tumors with satisfactory results. Silencing of tumor genes using the ep-Patch was also demonstrated on mice. This pliable electroporation patch method constitutes a novel way of in vivo delivery of siRNA and DNA to certain tissues or organs to circumvent the disadvantages of existing methodologies for in vivo delivery of nucleic acid molecules.

Fentanyl Transdermal Patch

MedlinePlus

Fentanyl patches are used to relieve severe pain in people who are expected to need pain medication ... and who cannot be treated with other medications. Fentanyl is in a class of medications called opiate ( ...

Selegiline Transdermal Patch

MedlinePlus

... patch from direct heat such as heating pads, electric blankets, heat lamps, saunas, hot tubs, and heated ... may make you drowsy. Do not drive a car or operate machinery until you know how this ...

Nicotine Transdermal Patch

MedlinePlus

... patches are used to help people stop smoking cigarettes. They provide a source of nicotine that reduces ... cause harm to the fetus.do not smoke cigarettes or use other nicotine products while using nicotine ...

Testosterone Transdermal Patch

MedlinePlus

... one else can use it accidentally or on purpose. Keep track of how many patches are left ... to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in ...

Nitroglycerin Transdermal Patch

MedlinePlus

... vasodilators. It works by relaxing the blood vessels so that the heart does not need to work ... patches may be applied in slightly different ways, so be sure to follow the directions included with ...

Current usage and future directions for the bovine pericardial patch.

PubMed

Li, Xin; Guo, Yuanyuan; Ziegler, Kenneth R; Model, Lynn S; Eghbalieh, Sammy D D; Brenes, Robert A; Kim, Susun T; Shu, Chang; Dardik, Alan

2011-05-01

Bovine pericardium (BP) is widely used in surgery and is commonly used as a patch after arteriotomy in cardiovascular surgery. BP patches have several advantages compared with prosthetic patches, including superior biocompatability, easy handling, less suture line bleeding, and possibly reduced rates of infection. These advantages of BP have led to its common use during carotid endarterectomy (CEA). However, long-term clinical results reported after CEA have suggested several issues that may be related to the patch, including restenosis, pseudoaneurysm formation, infection, fibrosis, calcification, and thrombosis. These complications may diminish the long-term efficacy of CEA and suggest potential areas for improvement of surgical patches. Understanding the mechanisms by which BP heals after patch angioplasty may lead to next generation tissue-engineered patches. Published by Elsevier Inc.

Fentanyl Patch Can Be Deadly to Children

MedlinePlus

... Products For Consumers Home For Consumers Consumer Updates Fentanyl Patch Can Be Deadly to Children Share Tweet ... from accidental exposure to a skin patch containing fentanyl, a powerful pain reliever. As a result of ...

On the Persistent Shape and Coherence of Pulsating Auroral Patches

NASA Astrophysics Data System (ADS)

Humberset, B. K.; Gjerloev, J. W.; Mann, I. R.; Michell, R. G.; Samara, M.

2018-05-01

The pulsating aurora covers a broad range of fluctuating shapes that are poorly characterized. The purpose of this paper is therefore to provide objective and quantitative measures of the extent to which pulsating auroral patches maintain their shape, drift and fluctuate in a coherent fashion. We present results from a careful analysis of pulsating auroral patches using all-sky cameras. We have identified four well-defined individual patches that we follow in the patch frame of reference. In this way we avoid the space-time ambiguity which complicates rocket and satellite measurements. We find that the shape of the patches is remarkably persistent with 85-100% of the patch being repeated for 4.5-8.5 min. Each of the three largest patches has a temporal correlation with a negative dependence on distance, and thus does not fluctuate in a coherent fashion. A time-delayed response within the patches indicates that the so-called streaming mode might explain the incoherency. The patches appear to drift differently from the SuperDARN-determined E→×B→ convection velocity. However, in a nonrotating reference frame the patches drift with 230-287 m/s in a north eastward direction, which is what typically could be expected for the convection return flow.

Lipid-glass adhesion in giga-sealed patch-clamped membranes.

PubMed

Opsahl, L R; Webb, W W

1994-01-01

Adhesion between patch-clamped lipid membranes and glass micropipettes is measured by high contrast video imaging of the mechanical response to the application of suction pressure across the patch. The free patch of membrane reversibly alters both its contact angle and radius of curvature on pressure changes. The assumption that an adhesive force between the membrane and the pipette can sustain normal tension up to a maximum Ta at the edge of the free patch accounts for the observed mechanical responses. When the normal component of the pressure-induced membrane tension exceeds Ta membrane at the contact point between the free patch and the lipid-glass interface is pulled away from the pipette wall, resulting in a decreased radius of curvature for the patch and an increased contact angle. Measurements of the membrane radius of curvature as a function of the suction pressure and pipette radius determine line adhesion tensions Ta which range from 0.5 to 4.0 dyn/cm. Similar behavior of patch-clamped cell membranes implies similar adhesion mechanics.

Strengthening of Existing Bridge Structures for Shear and Bending with Carbon Textile-Reinforced Mortar.

PubMed

Herbrand, Martin; Adam, Viviane; Classen, Martin; Kueres, Dominik; Hegger, Josef

2017-09-19

Increasing traffic loads and changes in code provisions lead to deficits in shear and flexural capacity of many existing highway bridges. Therefore, a large number of structures are expected to require refurbishment and strengthening in the future. This projection is based on the current condition of many older road bridges. Different strengthening methods for bridges exist to extend their service life, all having specific advantages and disadvantages. By applying a thin layer of carbon textile-reinforced mortar (CTRM) to bridge deck slabs and the webs of pre-stressed concrete bridges, the fatigue and ultimate strength of these members can be increased significantly. The CTRM layer is a combination of a corrosion resistant carbon fiber reinforced polymer (CFRP) fabric and an efficient mortar. In this paper, the strengthening method and the experimental results obtained at RWTH Aachen University are presented.

Strengthening of Existing Bridge Structures for Shear and Bending with Carbon Textile-Reinforced Mortar

PubMed Central

Herbrand, Martin; Classen, Martin; Kueres, Dominik; Hegger, Josef

2017-01-01

Increasing traffic loads and changes in code provisions lead to deficits in shear and flexural capacity of many existing highway bridges. Therefore, a large number of structures are expected to require refurbishment and strengthening in the future. This projection is based on the current condition of many older road bridges. Different strengthening methods for bridges exist to extend their service life, all having specific advantages and disadvantages. By applying a thin layer of carbon textile-reinforced mortar (CTRM) to bridge deck slabs and the webs of pre-stressed concrete bridges, the fatigue and ultimate strength of these members can be increased significantly. The CTRM layer is a combination of a corrosion resistant carbon fiber reinforced polymer (CFRP) fabric and an efficient mortar. In this paper, the strengthening method and the experimental results obtained at RWTH Aachen University are presented. PMID:28925962

Current usage and future directions for the bovine pericardial patch

PubMed Central

Li, Xin; Guo, Yuanyuan; Ziegler, Kenneth; Model, Lynn; Eghbalieh, Sammy D. D.; Brenes, Robert; Kim, Susun; Shu, Chang; Dardik, Alan

2010-01-01

Bovine pericardium is widely used in surgery and is commonly used for a patch after arteriotomy during cardiovascular surgery. Bovine pericardial patches have several advantages compared to prosthetic patches, including superior biocompatability, easy handling, less suture line bleeding and possibly reduced rates of infection. These advantages of bovine pericardium have led to its common use during carotid endarterectomy. However, long-term clinical results reported after carotid endarterectomy have suggested several issues that may be related to the patch including restenosis, pseudoaneurysm formation, infection, fibrosis, calcification and thrombosis. These complications may diminish the long-term efficacy of carotid endarterectomy and suggest potential areas for improvement of surgical patches. Understanding the mechanisms by which bovine pericardium heals after patch angioplasty may lead to next generation tissue engineered patches. PMID:21276709

Prestressing effect of cold-drawn short NiTi SMA fibres in steel reinforced mortar beams

NASA Astrophysics Data System (ADS)

Choi, Eunsoo; Kim, Dong Joo; Hwang, Jin-Ha; Kim, Woo Jin

2016-08-01

This study investigated the prestressing effect of cold-drawn short NiTi shape memory alloy (SMA) fibres in steel reinforced mortar beams. The SMA fibres were mixed with 1.5% volume content in a mortar matrix with the compressive strength of 50 MPa. The SMA fibres had an average length of 34 mm, and they were manufactured with a dog-bone shape: the diameters of the end- and middle-parts were 1.024 and 1.0 mm, respectively. Twenty mortar beams with the dimensions of 40 mm × 40 mm × 160 mm (B × H × L) were prepared. Two types of tests were conducted. One was to investigate the prestressing effect of the SMA fibres, and the beams with the SMA fibres were heated at the bottom. The other was to assess the bending behaviour of the beams prestressed by the SMA fibres. The SMA fibres induced upward deflection and cracking at the top surface by heating at the bottom; thus, they achieved an obvious prestressing effect. The beams that were prestressed by the SMA fibres did not show a significant difference in bending behaviour from that of the SMA fibre reinforced beams that were not subjected to heating. Stress analysis of the beams indicated that the prestressing effect decreased in relation to the cooling temperature.

Experimental Barley Flour Production in 12,500-Year-Old Rock-Cut Mortars in Southwestern Asia.

PubMed

Eitam, David; Kislev, Mordechai; Karty, Adiel; Bar-Yosef, Ofer

2015-01-01

Experimental archaeology at a Natufian site in the Southern Levant documents for the first time the use of 12,500-year-old rock-cut mortars for producing wild barley flour, some 2,000 to 3,000 years before cereal cultivation. Our reconstruction involved processing wild barley on the prehistoric threshing floor, followed by use of the conical mortars (a common feature in Natufian sites), thereby demonstrating the efficient peeling and milling of hulled grains. This discovery complements nearly 80 years of investigations suggesting that the Natufians regularly harvested almost-ripe wild cereals using sickles hafted with flint blades. Sickles had been replicated in the past and tested in the field for harvesting cereals, thusly obtaining the characteristic sheen along the edge of the hafted flint blades as found in Natufian remnants. Here we report that Natufian wide and narrow conical mortars enabled the processing of wild barley for making the groats and fine flour that provided considerable quantities of nourishment. Dishes in the Early Natufian (15,000-13,500 CalBP) were groat meals and porridge and subsequently, in the Late Natufian (13,500-11,700 CalBP), we suggest that unleavened bread made from fine flour was added. These food preparing techniques widened the dietary breadth of the sedentary Natufian hunter-gatherers, paving the way to the emergence of farming communities, the hallmark of the Neolithic Revolution.

The effects of the sequential addition of synthesis parameters on the performance of alkali activated fly ash mortar

NASA Astrophysics Data System (ADS)

Dassekpo, Jean-Baptiste Mawulé; Zha, Xiaoxiong; Zhan, Jiapeng; Ning, Jiaqian

Geopolymer is an energy efficient and sustainable material that is currently used in construction industry as an alternative for Portland cement. As a new material, specific mix design method is essential and efforts have been made to develop a mix design procedure with the main focus on achieving better compressive strength and economy. In this paper, a sequential addition of synthesis parameters such as fly ash-sand, alkaline liquids, plasticizer and additional water at well-defined time intervals was investigated. A total of 4 mix procedures were used to study the compressive performance on fly ash-based geopolymer mortar and the results of each method were analyzed and discussed. Experimental results show that the sequential addition of sodium hydroxide (NaOH), sodium silicate (Na2SiO3), plasticizer (PL), followed by adding water (WA) increases considerably the compressive strengths of the geopolymer-based mortar. These results clearly demonstrate the high significant influence of sequential addition of synthesis parameters on geopolymer materials compressive properties, and also provide a new mixing method for the preparation of geopolymer paste, mortar and concrete.

Lidocaine patches reduce pain in trauma patients with rib fractures.

PubMed

Zink, Karen A; Mayberry, John C; Peck, Ellen G; Schreiber, Martin A

2011-04-01

Rib fracture pain is notoriously difficult to manage. The lidocaine patch is effective in other pain scenarios with an excellent safety profile. This study assesses the efficacy of lidocaine patches for treating rib fracture pain. A prospectively gathered cohort of patients with rib fracture was retrospectively analyzed for use of lidocaine patches. Patients treated with lidocaine patches were matched to control subjects treated without patches. Subjective pain reports and narcotic use before and after patch placement, or equivalent time points for control subjects, were gathered from the chart. All patients underwent long-term follow-up, including a McGill Pain Questionnaire (MPQ). Twenty-nine patients with lidocaine patches (LP) and 29 matched control subjects (C) were analyzed. During the 24 hours before patch placement, pain scores and narcotic use were similar (LP 5.3, C 4.6, P = 0.19 and LP 51, C 32 mg morphine, P = 0.17). In the 24 hours after patch placement, LP patients had a greater decrease in pain scores (LP 1.2, C 0.0, P = 0.01) with no change in narcotic use (LP -8.4, C 0.5-mg change in morphine, P = 0.25). At 60 days, LP patients had a lower MPQ pain score (LP 7.7, C 12.2, P < 0.01), although only one patient was still using a patch. There was no difference in time to return to baseline activity (LP 73, C 105 days, P = 0.16) and no adverse events. Lidocaine patches are a safe, effective adjunct for rib fracture pain. Lidocaine patches resulted in a sustained reduction in pain, outlasting the duration of therapy.

Micro-Laser-Induced Breakdown Spectroscopy (Micro-LIBS) Study on Ancient Roman Mortars.

PubMed

Pagnotta, Stefano; Lezzerini, Marco; Ripoll-Seguer, Laura; Hidalgo, Montserrat; Grifoni, Emanuela; Legnaioli, Stefano; Lorenzetti, Giulia; Poggialini, Francesco; Palleschi, Vincenzo

2017-04-01

The laser-induced breakdown spectroscopy (LIBS) technique was used for analyzing the composition of an ancient Roman mortar (5th century A.D.), exploiting an experimental setup which allows the determination of the compositions of binder and aggregate in few minutes, without the need for sample treatment. Four thousand LIBS spectra were acquired from an area of 10 mm 2 , with a 50 µm lateral resolution. The elements of interest in the mortar sample (H, C, O, Na, Mg, Al, Si, K, Ca, Ti, Mn, Fe) were detected and mapped. The collected data graphically shown as compositional images were interpreted using different statistical approaches for the determination of the chemical composition of the binder and aggregate fraction. The methods of false color imaging, blind separation, and self-organizing maps were applied and their results are discussed in this paper. In particular, the method based on the use of self-organizing maps gives well interpretable results in very short times, without any reduction in the dimensionality of the system.

Influence of Curing on the Strength Development of Calcium-Containing Geopolymer Mortar

PubMed Central

Li, Xueying; Wang, Zheng; Jiao, Zhenzhen

2013-01-01

This paper investigated the curing effects on the mechanical properties of calcium-containing geopolymer mortar. Three precursors are used: Class C fly ash, Class F fly ash plus calcium hydroxide and Class F fly ash plus slag. Curing conditions included: (1) standard curing at 20 ± 3 °C and RH 95% (C); (2) steam curing at 60 °C for 24 h (S); (3) steam curing at 60 °C for 6 h (S6); and (4) oven curing at 60 °C for 24 h (O), then the latter three followed by the standard curing. Under the standard conditions, the flexural strength and compressive strength of Class C fly ash geopolymer mortars developed quickly until the age of 7 days, followed by a gradual increase. Specimens with Class F fly ash plus Ca(OH)2 showed slow increase till the age of 28 days. Under these non-standard conditions (2–4), all specimens showed higher 3-day strength, while later strengths were either higher or lower than those in standard conditions, depending on the type of the precursor. PMID:28788377

Influence of Curing on the Strength Development of Calcium-Containing Geopolymer Mortar.

PubMed

Li, Xueying; Wang, Zheng; Jiao, Zhenzhen

2013-11-07

This paper investigated the curing effects on the mechanical properties of calcium-containing geopolymer mortar. Three precursors are used: Class C fly ash, Class F fly ash plus calcium hydroxide and Class F fly ash plus slag. Curing conditions included: (1) standard curing at 20 ± 3 °C and RH 95% (C); (2) steam curing at 60 °C for 24 h (S); (3) steam curing at 60 °C for 6 h (S6); and (4) oven curing at 60 °C for 24 h (O), then the latter three followed by the standard curing. Under the standard conditions, the flexural strength and compressive strength of Class C fly ash geopolymer mortars developed quickly until the age of 7 days, followed by a gradual increase. Specimens with Class F fly ash plus Ca(OH)₂ showed slow increase till the age of 28 days. Under these non-standard conditions (2-4), all specimens showed higher 3-day strength, while later strengths were either higher or lower than those in standard conditions, depending on the type of the precursor.

Monitoring the self-healing process of biomimetic mortar using coda wave interferometry method

NASA Astrophysics Data System (ADS)

Liu, Shukui; Basaran, Zeynep; Zhu, Jinying; Ferron, Raissa

2014-02-01

Internal stresses might induce microscopic cracks in concrete, which can provide pathways for ingress of harmful chemicals and can lead to loss of strength. Recent research in concrete materials suggests that it might be possible to develop a smart cement-based material that is capable of self-healing by leveraging the metabolic activity of microorganisms to provide biomineralization. Limited research on biomineralization in cement-based systems has shown promising results that healing of cracks can occur on the surface of concrete and reduce permeability. This paper presents the results from an investigation regarding the potential for a cement-based material to repair itself internally through biomineralization. Compressive strength test and coda wave interferometry (CWI) analyses were conducted on mortar samples that were loaded to 70% of their compressive strength and cured in different conditions. Experimental results indicate that the damaged mortar samples with microorganisms showed significantly higher strength development and higher increase of ultrasonic wave velocity compared to samples without microorganisms at 7 and 28 days.

An extended patch-dynamic framework for food chains in fragmented landscapes

PubMed Central

Liao, Jinbao; Chen, Jiehong; Ying, Zhixia; Hiebeler, David E.; Nijs, Ivan

2016-01-01

Habitat destruction, a key determinant of species loss, can be characterized by two components, patch loss and patch fragmentation, where the former refers to the reduction in patch availability, and the latter to the division of the remaining patches. Classical metacommunity models have recently explored how food web dynamics respond to patch loss, but the effects of patch fragmentation have largely been overlooked. Here we develop an extended patch-dynamic model that tracks the patch occupancy of the various trophic links subject to colonization-extinction-predation dynamics by incorporating species dispersal with patch connectivity. We found that, in a simple food chain, species at higher trophic level become extinct sooner with increasing patch loss and fragmentation due to the constraint in resource availability, confirming the trophic rank hypothesis. Yet, effects of fragmentation on species occupancy are largely determined by patch loss, with maximal fragmentation effects occurring at intermediate patch loss. Compared to the spatially explicit simulations that we also performed, the current model with pair approximation generates similar community patterns especially in spatially clustered landscapes. Overall, our extended framework can be applied to model more complex food webs in fragmented landscapes, broadening the scope of existing metacommunity theory. PMID:27608823

Arbitrarily shaped dual-stacked patch antennas: A hybrid FEM simulation

NASA Technical Reports Server (NTRS)

Gong, Jian; Volakis, John L.

1995-01-01

A dual-stacked patch antenna is analyzed using a hybrid finite element - boundary integral (FE-BI) method. The metallic patches of the antenna are modeled as perfectly electric conducting (PEC) plates stacked on top of two different dielectric layers. The antenna patches may be of any shape and the lower patch is fed by a coaxial cable from underneath the ground plane or by an aperture coupled microstrip line. The ability of the hybrid FEM technique for the stacked patch antenna characterization will be stressed, and the EM coupling mechanism is also discussed with the aid of the computed near field patterns around the patches.

Microscale nutrient patches produced by zooplankton

PubMed Central

Lehman, John T.; Scavia, Donald

1982-01-01

Both track autoradiography and grain-density autoradiography show that individual zooplankton create miniature patches of dissolved nutrients and that algae exploit those regions to absorb phosphate. The patches are short lived and can be dispersed artificially by small-scale turbulence. Our data support a simple model of encounters between algae and nutrient plumes produced by swimming zooplankton. PMID:16593218

Hydrogel patches containing triclosan for acne treatment.

PubMed

Lee, Tae Wan; Kim, Jin Chul; Hwang, Sung Joo

2003-11-01

Adhesive hydrogel patches containing Triclosan (TS) were prepared as an anti-acne dosage form. Sodium polyacrylate and carboxymethylcellulose (sodium salt) were used as matrix polymers, and Al(3+), produced by the reaction of dihydroxy aluminum aminoacetate and L(+)-tartaric acid, was employed as a crosslinking agent for the negatively charged polymers. The crosslinking reactions were done at 25, 40 and 50 degrees C for predetermined time intervals. The semi-solid gels were obtained only when the reaction period was more than 12 h, but the polymer gels were fluidic with a shorter reaction. The swelling ratios increased as the reaction period was prolonged and the reaction temperature increased, indicating that the degree of the crosslinking is proportional to the reaction period and the temperature. On a scanning electron microphotograph, the crosslinked gel exhibited a honeycomb-like structure having pores of a few micrometers. The adhesive force of a patch, which could be easily attached to and peeled off facial skin, was 45.5 gmf and it increased by adding poly acrylic acid into the patch formulations. Propionibacterium acnes (ATCC 6919) growth inhibition area around the patch was not significant on an agar plate when TS content was 0.01 wt.%, but the antibacterial activity was apparent when the content was 0.05 wt.%. In vitro permeation revealed that up to 5 wt.% of Transcutol (TC) content in patch, TC, a permeation enhancer, significantly increased the amount of TS transported into hairless mouse skins but it did not substantially accelerate TS transportation into the receptors of Franz diffusion cells. Since our patches for the treatment of acne was aimed to localize TS into skins, TC content of 5 wt.% seems to be adequate for the dermal delivery of TS. The model patches in this study would be applicable to facial skins for the treatment of acne.

Petrographic microscope investigation of mortar and ceramic technologies for the conservation of the built heritage

NASA Astrophysics Data System (ADS)

Pavia, S.; Caro, S.

2007-07-01

Polarised-light (or petrographic) microscopy has been widely applied to heritage materials to assess composition and diagnose damage. However, instead, this paper focuses on the petrographic investigation of brick and mortar technologies for the production of quality repair materials compatible with their adjacent fabrics. Furthermore, the paper relates production technologies to the physical properties of the materials fabricated, and thus their final quality and durability. According to Cesare Brandi´s theory of compatibility (the 20th century architect on whose work modern conservation theory and practice are largely based) existing historic materials should be replaced with their equivalent. This paper demonstrates that polarised-light microscopy provides data on the origin and nature of raw materials, and processing parameters such as blending, mixing, firing, calcination and slaking, and how these relate to the quality of the final product. In addition, this paper highlights the importance of production technologies as these directly impact the physical properties of the materials fabricated and thus determine their final quality and durability. In this context, the paper investigates mortar calcination and slaking, two important operations in the manufacture of building limes that govern the reactivity, shrinkage and water retention of a lime binder which will impact mortar's properties such as workability, plasticity and carbonation speed, and these in turn will determine the ease of execution, durability and strength of a lime mortar. Petrographic analysis also provides evidence of ceramic technology including identification of local or foreign production and processing parameters such as sieving, blending, mixing and firing. A petrographic study of the ceramic matrix coupled to the diagnosis of mineral phases formed during firing allows to quantify sintering and vitrification and thus determine firing temperatures. Finally, certain features of the raw

Mating success of males with and without wing patch in Drosophila biarmipes.

PubMed

Hegde, S N; Chethan, B K; Krishna, M S

2005-10-01

Some males of D. biarmipes--synonym of D. rajasekari and D. raychaudhuri have a black patch on the wing. The patch extends from the apical margin of wing to the third longitudinal vein. Field and laboratory studies have been carried out in D. biarmipes to study role of male's wing patch in mating success. The field study shows that nature favors D. biarmipes males with patch. Although males without patch mated, males with patch have higher mating success suggesting the role of wing patch during courtship. Further, among mating males, males with patch had longer wings than males without patch. During courtship, males with patch oriented and mated faster; performed courtship acts such as tapping, scissoring, vibration, licking and twist dance more times than males without patch in both competitive and non-competitive situations. The results indicate that there is a casual relationship between the presence of wing patch, mating speed and success. Also there is a correlation between presence of wing patch, size of the flies and mating success.

A disposable adhesive patch for stress urinary incontinence.

PubMed

North, B B

1998-04-01

Stress urinary incontinence (SUI) affects 5 million women in the United States. Current surgical and pharmacological management options are often unsuccessful, forcing many sufferers to rely on bulky and uncomfortable sanitary protection. This study evaluated the safety, efficacy, and acceptability of a small, disposable adhesive patch designed to seal the urethral opening and prevent urine leakage. Thirty-seven women with mild-to-moderate SUI were recruited from a suburban community. Each volunteer participated in a 21-week protocol that included a 1-week qualifying period, 4-week (pretest) control period, 12-week patch-use period, and 4-week (posttest) control period. Patch efficacy was evaluated with quantitative (leakage into sanitary napkin) and qualitative (voiding diary) measures of urine leakage. Symptom questionnaires were also completed. Overall leakage was reduced by 60%, from 1.1 +/- .3 standard error of the mean (SEM) to .44 +/- .11 (SEM) grams of urine per hour. Perception of dryness, measured by voiding diaries, improved 67%, from 13.3 +/- 1.9 (SEM) to 4.3 +/- 0.9 (SEM) leakage episodes per week. Safety evaluation included peri-urethral cytology, urinalysis and urine culture, and vaginal cultures. All measures were unaffected by 3 months of patch use. Acceptability was assessed with questionnaires that measured the impact of patch use on activities of daily living and overall quality of life. Women reported a significant improvement in both measures. All but one volunteer found that the patch was comfortable and were able to place it correctly between the inner labia with written instructions only. The disposable patch significantly reduced urine leakage resulting from SUI in community-based women. Dryness improved significantly, both by measurement of actual leakage and by the subject's perception of dryness. The maturation index of the vestibular tissues showed an increase in the number of superficial cells during patch use. Otherwise, there were

Implementation for wideband applications using UWB fractal patch antenna

NASA Astrophysics Data System (ADS)

Kumar, D. Naresh

2018-04-01

This paper defines in detail about the diverse fractal patch antenna. Microstrip patch antennas has evolved in the field of research and development extending its impact across wide range of applications. A combination of patch antenna with fractal patterns has become a tryout to outspread it further. Because of its low profile nature patch antennas have added to a lot of prominence. Apart from have this property it can also be renovated further for wide bandwidth (2929 MHz) applications, as it exhibits self-analogous property. This antenna is premeditated on a patch using Sierpinski(4.040 GHz, 6.566 GHz) and Koch fractal geometries respectively. The antenna is designed using HFSS software.

Design and basic properties of ternary gypsum-based mortars

NASA Astrophysics Data System (ADS)

Doleželová, M.; Vimmrová, A.

2017-10-01

Ternary mortars, prepared from gypsum, hydrated lime and three types of pozzolan were designed and tested. As a pozzolan admixture crushed ceramic, silica fume and granulated blast slag were used. The amount of pozzolans in the mixtures was determined according to molar weight of amorphous SiO2 in the material. The samples were stored under the water. The basic physical properties and mechanical properties were measured. The properties were compared with the properties of material without pozzolan. The best results in the water environment were achieved by the samples with silica fume.

Germinant-enhanced decontamination of Bacillus spores adhered to iron and cement-mortar drinking water infrastructures.

PubMed

Szabo, Jeffrey G; Muhammad, Nur; Heckman, Lee; Rice, Eugene W; Hall, John

2012-04-01

Germination was evaluated as an enhancement to decontamination methods for removing Bacillus spores from drinking water infrastructure. Germinating spores before chlorinating cement mortar or flushing corroded iron was more effective than chlorinating or flushing alone.

Nanowired three-dimensional cardiac patches

NASA Astrophysics Data System (ADS)

Dvir, Tal; Timko, Brian P.; Brigham, Mark D.; Naik, Shreesh R.; Karajanagi, Sandeep S.; Levy, Oren; Jin, Hongwei; Parker, Kevin K.; Langer, Robert; Kohane, Daniel S.

2011-11-01

Engineered cardiac patches for treating damaged heart tissues after a heart attack are normally produced by seeding heart cells within three-dimensional porous biomaterial scaffolds. These biomaterials, which are usually made of either biological polymers such as alginate or synthetic polymers such as poly(lactic acid) (PLA), help cells organize into functioning tissues, but poor conductivity of these materials limits the ability of the patch to contract strongly as a unit. Here, we show that incorporating gold nanowires within alginate scaffolds can bridge the electrically resistant pore walls of alginate and improve electrical communication between adjacent cardiac cells. Tissues grown on these composite matrices were thicker and better aligned than those grown on pristine alginate and when electrically stimulated, the cells in these tissues contracted synchronously. Furthermore, higher levels of the proteins involved in muscle contraction and electrical coupling are detected in the composite matrices. It is expected that the integration of conducting nanowires within three-dimensional scaffolds may improve the therapeutic value of current cardiac patches.

Correlation of open cell-attached and excised patch clamp techniques.

PubMed

Filipovic, D; Hayslett, J P

1995-11-01

The excised patch clamp configuration provides a unique technique for some types of single channel analyses, but maintenance of stable, long-lasting preparations may be confounded by rundown and/or rapid loss of seal. Studies were performed on the amiloride-sensitive Na+ channel, located on the apical surface of A6 cells, to determine whether the nystatin-induced open cell-attached patch could serve as an alternative configuration. Compared to excised inside-out patches, stable preparations were achieved more readily with the open cell-attached patch (9% vs. 56% of attempts). In both preparations, the current voltage (I-V) relation was linear, current amplitudes were equal at opposite equivalent clamped voltages, and Erev was zero in symmetrical Na+ solutions, indicating similar Na+ activities on the cytosolic and external surfaces of the patch. Moreover, there was no evidence that nystatin altered channel activity in the patch because slope conductance (3-4pS) and Erev (75 mV), when the bath was perfused with a high K:low Na solution (ENa = 80 mV), were nearly equal in both patch configurations. Our results therefore indicate that the nystatin-induced open cell-attached patch can serve as an alternative approach to the excised inside-out patch when experiments require modulation of univalent ions in the cytosol.

Field evaluation of an engineering control for respirable crystalline silica exposures during mortar removal.

PubMed

Collingwood, Scott; Heitbrink, William A

2007-11-01

During mortar removal with a right angle grinder, a building renovation process known as "tuck pointing," worker exposures to respirable crystalline silica can be as high as 5 mg/m(3), 100 times the recommended exposure limit developed by the National Institute for Occupational Safety and Health. To reduce the risk of silicosis among these workers, a vacuum cleaner can be used to exhaust 80 ft(3)/min (2.26 m(3)/min) from a hood mounted on the grinder. Field trials examined the ability of vacuum cleaners to maintain adequate exhaust ventilation rates and measure exposure outcomes when using this engineering control. These field trials involved task-based exposure measurement of respirable dust and crystalline silica exposures during mortar removal. These measurements were compared with published exposure data. Vacuum cleaner airflows were obtained by measuring and digitally logging vacuum cleaner static pressure at the inlet to the vacuum cleaner motor. Static pressures were converted to airflows based on experimentally determined fan curves. In two cases, video exposure monitoring was conducted to study the relationship between worker activities and dust exposure. Worker activities were video taped concurrent with aerosol photometer measurement of dust exposure and vacuum cleaner static pressure as a measure of airflow. During these field trials, respirable crystalline silica exposures for 22 samples had a geometric mean of 0.06 mg/m(3) and a range of less than 0.01 to 0.86 mg/m(3). For three other studies, respirable crystalline silica exposures during mortar removal have a geometric means of 1.1 to 0.35. Although this field study documented noticeably less exposure to crystalline silica, video exposure monitoring found that the local exhaust ventilation provided incomplete dust control due to low exhaust flow rates, certain work practices, and missing mortar. Vacuum cleaner airflow decrease had a range of 3 to 0.4 ft(3)/min (0.08 to 0.01 m(3)/sec(2)) over a range

Properties of microcement mortar with nano particles

NASA Astrophysics Data System (ADS)

Alimeneti, Narasimha Reddy

Carbon nanotubes (CNT) and Carbon nanofibers (CNF) are one of the toughest and stiffest materials in the world presently with extreme properties yet to be discovered in terms of elastic modulus and tensile strength. Due to the advanced properties of these materials they are being used in almost all fields of science at nanolevel and are being used in construction industry recently for improvement of material properties. Microcement is fine ground cement which as half the particle size of ordinary Portland cement. In this research the behavior of cement mortar of micro cement with the addition of nanoparticles is studied. Due to high aspect ratio and strong van der Waal forces between the particles of CNT and CNF, they agglomerate and form bundles when mixed with water, sonication method is used to mix nanoparticles with few drops of surfactant and super plasticizer. Mechanical properties such as compressive strength and flexural strength with CNT and CNF composites are examined and compared with control samples. 0.1% and 0.05 % of nanoparticles (both CNT and CNF) by the weight of cement are used in this research and 0.8% of super plasticizer by weight of cement was also used along with 0.4, 0.45 and 0.50 water cement ratios for making specimens for compression test. The compressive strength results are not satisfactory as there was no constant increase in strength with all the composites, however strength of few nanocomposites increased by a good percentage. 0.5 water cement ratio cement mortar had compressive strength of 7.15 ksi (49.3 MPa), whereas sample with 0.1% CNT showed 8.38 ksi (57.8 MPa) with 17% increase in strength after 28 days. Same trend was followed by 0.4 water cement ratio as the compressive strength of control sample was 8.89 ksi (61.3 MPa), with 0.05% of CNT strength increased to 10.90 ksi (75.2 MPa) with 23% increase in strength. 0.4 water cement ratio was used for flexural tests including 0.1%, 0.05% of CNT and 0.1%, 0.05% of CNF with 0

Patch Time Allocation and Oviposition Behavior in Response to Patch Quality and the Presence of a Generalist Predator in Meteorus pulchricornis (Hymenoptera: Braconidae)

PubMed Central

Sheng, Sheng; Ling, Meng; Fu-an, Wu; Baoping, Li

2015-01-01

Foraging parasitoids often must estimate local risk of predation just as they must estimate local patch value. Here, we investigate the effects a generalist predator Chlaenius bioculatus (Coleoptera: Carabidae), has on the oviposition behavior and the patch residence decisions of a solitary parasitoid Meteorus pulchricornis (Hymenoptera: Braconidae) in response to the varying host quality of Spodoptera litura (Lepidoptera: Noctuidae) larvae (L2 and L4). M. pulchricornis attacked more L4 than on L2 hosts, with the difference in attack rate varying depending on predation treatments, greater in the presence (either actively feeding or not) of the predator than in the absence of it. The parasitoid attacked fewer L2 and L4 hosts when the predator was actively feeding than when it was not feeding or not present in the patch. M. pulchricornis decreased the patch leaving tendency with increasing rejections of hosts, but increased the tendency in response to the presence of the predator as compared with the absence of it, and furthermore, increased the patch leaving tendency when the predator was actively feeding as compared with when it was not. Our study suggests that M. pulchricornis can exploit high quality patches while minimizing predation risk, by attacking more hosts in high quality patches while reducing total patch time in response to risk of predation. PMID:25943317

Effect of a micro-copolymer addition on the thermal conductivity of fly ash mortars.

PubMed

Durán-Herrera, A; Campos-Dimas, J K; Valdez-Tamez, P L; Bentz, D P

2016-07-01

In this study, a copolymer composed of hollow spherical particles with an average particle size of 90 µm was evaluated as a lightweight aggregate in Portland cement-fly ash mortars to improve the thermal conductivity ( k ) of the composite. Mortars were produced for three different water/binder ratios by mass ( w/b ), 0.4, 0.5 and 0.6. Optimized proportions were obtained for a minimum target compressive strength of 35 kg f /cm 2 (3.4 MPa) according to the requirements of Mexican standards for non-structural masonry units. Thermal conductivity was determined for dry and saturated samples through the transient plane technique with average results of 0.16 W/(m·K) and 0.31 W/(m·K), respectively. These values represent an increment of 23 % and a reduction of 33 %, respectively, in comparison to an efficient Portland cement-based commercially available thermal insulator.

Effect of a micro-copolymer addition on the thermal conductivity of fly ash mortars

PubMed Central

Durán-Herrera, A.; Campos-Dimas, J. K.; Valdez-Tamez, P.L.; Bentz, D. P.

2015-01-01

In this study, a copolymer composed of hollow spherical particles with an average particle size of 90 µm was evaluated as a lightweight aggregate in Portland cement-fly ash mortars to improve the thermal conductivity (k) of the composite. Mortars were produced for three different water/binder ratios by mass (w/b), 0.4, 0.5 and 0.6. Optimized proportions were obtained for a minimum target compressive strength of 35 kgf/cm2 (3.4 MPa) according to the requirements of Mexican standards for non-structural masonry units. Thermal conductivity was determined for dry and saturated samples through the transient plane technique with average results of 0.16 W/(m·K) and 0.31 W/(m·K), respectively. These values represent an increment of 23 % and a reduction of 33 %, respectively, in comparison to an efficient Portland cement-based commercially available thermal insulator. PMID:27453717

Characterization of methacrylated polysaccharides in combination with amine-based monomers for application in mortar.

PubMed

Mignon, Arn; Devisscher, Dries; Vermeulen, Jolien; Vagenende, Maxime; Martins, José; Dubruel, Peter; De Belie, Nele; Van Vlierberghe, Sandra

2017-07-15

Smart pH-responsive superabsorbent polymers (SAPs) could be useful for self-healing of cracks in mortar. They will swell minimally during the alkaline conditions of mixing, leading to only small macro-pores but will swell stronger with a lower pH when water enters the cracks. As such, polysaccharides (alginate, chitosan and agarose) were methacrylated and cross-linked with amine-based monomers (dimethylaminoethyl methacrylate and dimethylaminopropyl methacrylamide) to induce a varying pH-sensitivity. These materials showed a strong cross-linking efficiency and induced moisture uptake capacities up to 122% at 95% relative humidity with a negligible hysteresis. Additionally, interesting pH-responsive swelling capacities were obtained, especially for SAPs based on chitosan and agarose with values up to 110gwater/gSAP. Most of these materials showed limited hydrolysis in cement filtrate solutions, making them very promising for use in mortar. Copyright © 2017 Elsevier Ltd. All rights reserved.

Force-controlled patch clamp of beating cardiac cells.

PubMed

Ossola, Dario; Amarouch, Mohamed-Yassine; Behr, Pascal; Vörös, János; Abriel, Hugues; Zambelli, Tomaso

2015-03-11

From its invention in the 1970s, the patch clamp technique is the gold standard in electrophysiology research and drug screening because it is the only tool enabling accurate investigation of voltage-gated ion channels, which are responsible for action potentials. Because of its key role in drug screening, innovation efforts are being made to reduce its complexity toward more automated systems. While some of these new approaches are being adopted in pharmaceutical companies, conventional patch-clamp remains unmatched in fundamental research due to its versatility. Here, we merged the patch clamp and atomic force microscope (AFM) techniques, thus equipping the patch-clamp with the sensitive AFM force control. This was possible using the FluidFM, a force-controlled nanopipette based on microchanneled AFM cantilevers. First, the compatibility of the system with patch-clamp electronics and its ability to record the activity of voltage-gated ion channels in whole-cell configuration was demonstrated with sodium (NaV1.5) channels. Second, we showed the feasibility of simultaneous recording of membrane current and force development during contraction of isolated cardiomyocytes. Force feedback allowed for a gentle and stable contact between AFM tip and cell membrane enabling serial patch clamping and injection without apparent cell damage.

Living cardiac patch: the elixir for cardiac regeneration.

PubMed

Lakshmanan, Rajesh; Krishnan, Uma Maheswari; Sethuraman, Swaminathan

2012-12-01

A thorough understanding of the cellular and muscle fiber orientation in left ventricular cardiac tissue is of paramount importance for the generation of artificial cardiac patches to treat the ischemic myocardium. The major challenge faced during cardiac patch engineering is to choose a perfect combination of three entities; cells, scaffolds and signaling molecules comprising the tissue engineering triad for repair and regeneration. This review provides an overview of various scaffold materials, their mechanical properties and fabrication methods utilized in cardiac patch engineering. Stem cell therapies in clinical trials and the commercially available cardiac patch materials were summarized in an attempt to provide a recent perspective in the treatment of heart failure. Various tissue engineering strategies employed thus far to construct viable thick cardiac patches is schematically illustrated. Though many strategies have been proposed for fabrication of various cardiac scaffold materials, the stage and severity of the disease condition demands the incorporation of additional cues in a suitable scaffold material. The scaffold may be nanofibrous patch, hydrogel or custom designed films. Integration of stem cells and biomolecular cues along with the scaffold may provide the right microenvironment for the repair of unhealthy left ventricular tissue as well as promote its regeneration.

Methods of Making and Using Shape Memory Polymer Composite Patches

NASA Technical Reports Server (NTRS)

Hood, Patrick J.

2011-01-01

A method of repairing a composite component having a damaged area including: laying a composite patch over the damaged area: activating the shape memory polymer resin to easily and quickly mold said patch to said damaged area; deactivating said shape memory polymer so that said composite patch retains the molded shape; and bonding said composite patch to said damaged part.

Runoff and erosion in a pinon-juniper woodland: Influence of vegetation patches

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

Reid, K.D.; Wilcox, B.P.; Breshears, D.D.

1999-12-01

In many semiarid regions, runoff and erosion differ according to vegetation patch type. These differences, although hypothesized to fundamentally affect ecological processes, have been poorly quantified. In a semiarid pinion-juniper woodland [Pinus edulis Engelm. and Juniperus monosperma (Engelm) Sarg.] in northern New Mexico, the authors measured runoff and erosion from the three patch types that compose these woodlands: Canopy patches (those beneath woody plants), vegetated patched in intercanopy areas, and bare patches in intercanopy areas. The bare intercanopy patches exhibited the highest rates, followed by vegetated intercanopy patches and then by canopy patches. Large convective summer storms, though relatively infrequent,more » generated much of the runoff and most of the sediment; prolonged frontal storms were capable of generating considerable runoff but little sediment. A portion of the runoff and most of the sediment generated from bare intercanopy patches was redistributed down-slope, probably to adjacent vegetated intercanopy patches, demonstrating connectivity between these two patch types. Their results indicate that there are significant and important differences in runoff and sediment production from the three patch types; that bare intercanopy patches act as sources of both water and sediment for the vegetated intercanopy patches; and that the transfer of water and sediment at small scales is both frequent enough and substantial enough to be considered ecologically significant.« less

Germinant-Enhanced Decontamination of Bacillus Spores Adhered to Iron and Cement-Mortar Drinking Water Infrastructures

PubMed Central

Muhammad, Nur; Heckman, Lee; Rice, Eugene W.; Hall, John

2012-01-01

Germination was evaluated as an enhancement to decontamination methods for removing Bacillus spores from drinking water infrastructure. Germinating spores before chlorinating cement mortar or flushing corroded iron was more effective than chlorinating or flushing alone. PMID:22267659

Patch dynamics of a foraging assemblage of bees.

PubMed

Wright, David Hamilton

1985-03-01

The composition and dynamics of foraging assemblages of bees were examined from the standpoint of species-level arrival and departure processes in patches of flowers. Experiments with bees visiting 4 different species of flowers in subalpine meadows in Colorado gave the following results: 1) In enriched patches the rates of departure of bees were reduced, resulting in increases in both the number of bees per species and the average number of species present. 2) The reduction in bee departure rates from enriched patches was due to mechanical factors-increased flower handling time, and to behavioral factors-an increase in the number of flowers visited per inflorescence and in the number of inflorescences visited per patch. Bees foraging in enriched patches could collect nectar 30-45% faster than those foraging in control patches. 3) The quantitative changes in foraging assemblages due to enrichment, in terms of means and variances of species population sizes, fraction of time a species was present in a patch, and in mean and variance of the number of species present, were in reasonable agreement with predictions drawn from queuing theory and studies in island biogeography. 4) Experiments performed with 2 species of flowers with different corolla tube lengths demonstrated that manipulation of resources of differing availability had unequal effects on particular subsets of the larger foraging community. The arrival-departure process of bees on flowers and the immigration-extinction process of species on islands are contrasted, and the value of the stochastic, species-level approach to community composition is briefly discussed.

sts-130patch-design-finalthreads

NASA Image and Video Library

2009-09-18

STS130-S-001 (September 2009) --- The STS-130 patch was designed by the crew to reflect both the objectives of the mission and its place in the history of human spaceflight. The main goal of the mission is to deliver Node 3 and the Cupola to the International Space Station (ISS). Node 3, named ?Tranquility,? will contain life support systems enabling continued human presence in orbit aboard the ISS. The shape of the patch represents the Cupola, which is the windowed robotics viewing station, from which astronauts will have the opportunity not only to monitor a variety of ISS operations, but also to study our home planet. The image of Earth depicted in the patch is the first photograph of Earth taken from the moon by Lunar Orbiter I on Aug. 23, 1966. As both a past and a future destination for explorers from planet Earth, the moon is thus represented symbolically in the STS-130 patch. The space shuttle Endeavour is pictured approaching the ISS, symbolizing the space shuttle's role as the prime construction vehicle for the ISS. The NASA insignia design for space shuttle flights is reserved for use by the astronauts and for other official use as the NASA Administrator may authorize. Public availability has been approved only in the forms of illustrations by the various news media. When and if there is any change in this policy, which is not anticipated, the change will be publicly announced. Photo credit: NASA

Single-Layer, All-Metal Patch Antenna Element with Wide Bandwidth

NASA Technical Reports Server (NTRS)

Chamberlain, Neil F.; Hodges, Richard E.; Zawardzki, Mark S.

2012-01-01

It is known that the impedance at the center of a patch antenna element is a short circuit, implying that a wire or post can be connected from the patch to the groundplane at this point without impacting radiation performance. In principle, this central post can be used to support the patch element, thus eliminating the need for dielectric. In spaceborne applications, this approach is problematic because a patch element supported by a single, thin post is highly susceptible to acoustic loads during launch. The technology reported here uses a large-diameter center post as its supporting structure. The supporting structure allows for the fabrication of a sufficiently rigid antenna element that can survive launch loads. The post may be either hollow or solid, depending on fabrication approach and/or mass constraints. The patch antenna element and support post are envisioned as being fabricated (milled) from a single piece of aluminum or other metal. Alternately, the patch plate and support column can be fabricated separately and then joined using fasteners, adhesive, or welding. Casting and electroforming are also viable techniques for manufacturing the metal patch part(s). The patch structure is then either bonded or fastened to the supporting groundplane. Arrays of patch elements can be fabricated by attaching several structures to a common groundplane/support structure.

Laparoscopic repair of perforated peptic ulcer: patch versus simple closure.

PubMed

Abd Ellatif, M E; Salama, A F; Elezaby, A F; El-Kaffas, H F; Hassan, A; Magdy, A; Abdallah, E; El-Morsy, G

2013-01-01

Laparoscopic correction of perforated peptic ulcer (PPU) has become an accepted way of management. Patch omentoplasty stayed for decades the main method of repair. The goal of the present study was to evaluate whether laparoscopic simple repair of PPU is as safe as patch omentoplasty. Since June 2005, 179 consecutive patients of PPU were treated by laparoscopic repair at our centers. We conducted a retrospective chart review in December 2012. Group I (patch group) included patients who were treated with standard patch omentoplasty. Group II (non-patch group) included patients who received simple repair without patch. From June 2007 to Dec. 2012, 179 consecutive patients of PPU who were treated by laparoscopic repair at our centers were enrolled in this multi-center retrospective study. 108 patients belong to patch group. While 71 patients were treated with laparoscopic simple repair. Operative time was significantly shorter in group II (non patch) (p = 0.01). No patient was converted to laparotomy. There was no difference in age, gender, ASA score, surgical risk (Boey's) score, and incidence of co-morbidities. Both groups were comparable in terms of hospital stay, time to resume oral intake, postoperative complications and surgical outcomes. Laparoscopic simple repair of PPU is a safe procedure compared with the traditional patch omentoplasty in presence of certain selection criteria. Copyright © 2013 Surgical Associates Ltd. Published by Elsevier Ltd. All rights reserved.

Reconfigurable Wideband Circularly Polarized Stacked Square Patch Antenna for Cognitive Radios

NASA Technical Reports Server (NTRS)

Barbosa Kortright, Miguel A.; Waldstein, Seth W.; Simons, Rainee N.

2017-01-01

An almost square patch, a square patch and a stacked square patch with corner truncation for circular polarization (CP) are researched and developed at X-band for cognitive radios. Experimental results indicate, first, that the impedance bandwidth of a CP almost square patch fed from the edge by a 50 ohm line is 1.70 percent and second, that of a CP square patch fed from the ground plane side by a surface launch connector is 1.87 percent. Third, the impedance bandwidth of a CP stacked square patch fed by a surface launch connector is 2.22 percent. The measured center frequency for the CP square patch fed by a surface launch connector without and with an identical stacked patch is 8.45 and 8.1017 GHz, respectively. By stacking a patch, separated by a fixed air gap of 0.254 mm, the center frequency is observed to shift by as much as 348.3 MHz. The shift in the center frequency can be exploited to reconfigure the operating frequency by mechanically increasing the air gap. The results indicate that a tuning bandwidth of about 100 MHz can be achieved when the distance of separation between the driven patch and the stacked patch is increased from its initial setting of 0.254 to 1.016 mm.

Temporal Characteristics and Energy Deposition of Pulsating Auroral Patches

NASA Technical Reports Server (NTRS)

Humberset, B. K.; Gjerloev, J. W.; Samara, M.; Michell, R. G.; Mann, I. R.

2016-01-01

We present a careful statistical analysis of pulsating aurora (PA) using all-sky green line (557.7 nm) images obtained at 3.3 Hz. Six well-defined individual PA patches are identified and extracted using a contouring technique. Quantitative parameters such as the patch duration (on-time and off-time), peak intensity, and integrated intensity are determined for each patch and each pulsation. The resulting characteristics serve as strict observational constraints that any of the many competing theories attempting to explain PA must predict. The purpose of this paper is to determine the characteristics of PA patches in order to provide better observational constraints on the suggested mechanisms. All aspects of the temporal behavior of the individual patches appear to be erratic. Historically, PA has been defined very loosely and we argue that the use of the term pulsating is inappropriate since our findings and other published results are not regularly periodic and thus a more appropriate term may be fluctuating aurora. Further, we find that the observational constraints do not fit well with the flow cyclotron maser theory, which in particular is suggested to create PA patches. There is no clear candidate of the suggested mechanisms and drivers to explain the observational constraints set by the PA patches in a satisfactory manner.

Patch time allocation and oviposition behavior in response to patch quality and the presence of a generalist predator in Meteorus pulchricornis (Hymenoptera: Braconidae).

PubMed

Sheng, Sheng; Ling, Meng; Fu-An, Wu; Baoping, Li

2015-01-01

Foraging parasitoids often must estimate local risk of predation just as they must estimate local patch value. Here, we investigate the effects a generalist predator Chlaenius bioculatus (Coleoptera: Carabidae), has on the oviposition behavior and the patch residence decisions of a solitary parasitoid Meteorus pulchricornis (Hymenoptera: Braconidae) in response to the varying host quality of Spodoptera litura (Lepidoptera: Noctuidae) larvae (L2 and L4). M. pulchricornis attacked more L4 than on L2 hosts, with the difference in attack rate varying depending on predation treatments, greater in the presence (either actively feeding or not) of the predator than in the absence of it. The parasitoid attacked fewer L2 and L4 hosts when the predator was actively feeding than when it was not feeding or not present in the patch. M. pulchricornis decreased the patch leaving tendency with increasing rejections of hosts, but increased the tendency in response to the presence of the predator as compared with the absence of it, and furthermore, increased the patch leaving tendency when the predator was actively feeding as compared with when it was not. Our study suggests that M. pulchricornis can exploit high quality patches while minimizing predation risk, by attacking more hosts in high quality patches while reducing total patch time in response to risk of predation. © The Author 2015. Published by Oxford University Press on behalf of the Entomological Society of America.

Experimental Barley Flour Production in 12,500-Year-Old Rock-Cut Mortars in Southwestern Asia

PubMed Central

Eitam, David; Kislev, Mordechai; Karty, Adiel; Bar-Yosef, Ofer

2015-01-01

Experimental archaeology at a Natufian site in the Southern Levant documents for the first time the use of 12,500-year-old rock-cut mortars for producing wild barley flour, some 2,000 to 3,000 years before cereal cultivation. Our reconstruction involved processing wild barley on the prehistoric threshing floor, followed by use of the conical mortars (a common feature in Natufian sites), thereby demonstrating the efficient peeling and milling of hulled grains. This discovery complements nearly 80 years of investigations suggesting that the Natufians regularly harvested almost-ripe wild cereals using sickles hafted with flint blades. Sickles had been replicated in the past and tested in the field for harvesting cereals, thusly obtaining the characteristic sheen along the edge of the hafted flint blades as found in Natufian remnants. Here we report that Natufian wide and narrow conical mortars enabled the processing of wild barley for making the groats and fine flour that provided considerable quantities of nourishment. Dishes in the Early Natufian (15,000–13,500 CalBP) were groat meals and porridge and subsequently, in the Late Natufian (13,500–11,700 CalBP), we suggest that unleavened bread made from fine flour was added. These food preparing techniques widened the dietary breadth of the sedentary Natufian hunter-gatherers, paving the way to the emergence of farming communities, the hallmark of the Neolithic Revolution. PMID:26230092

Properties of Roman bricks and mortars used in Serapis temple in the city of Pergamon

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

Ozkaya, Ozlem Aslan; Boeke, Hasan, E-mail: hasanboke@iyte.edu.tr

Serapis temple, which was constructed in the Roman period in the city of Pergamon (Bergama/Turkey), is one of the most important monuments of the world heritage. In this study, the characteristics of bricks and mortars used in the temple have been determined in order to define the necessary characteristics of the intervention materials, which will be used in the conservation works of the temple. Several analyses were carried out to determine their basic physical properties, raw material compositions, mineralogical and microstructural properties using X-ray diffraction, Scanning Electron Microscope and a Thermo Gravimetric Analyzer. Analysis results indicated that the mortars aremore » stiff, compact and hydraulic due to the use of natural pozzolanic aggregates. The Roman bricks are of low density, high porosity and were produced from raw materials containing calcium poor clays fired at low temperatures.« less

Application of Bacillus subtilis 168 as a multifunctional agent for improvement of the durability of cement mortar.

PubMed

Park, Sung-Jin; Park, Jong-Myong; Kim, Wha-Jung; Ghim, Sa-Youl

2012-11-01

Microbiological calcium carbonate precipitation (MCCP) has been investigated for its ability to improve the durability of cement mortar. However, very few strains have been applied to crack remediation and strengthening of cementitious materials. In this study, we report the biodeposition of Bacillus subtilis 168 and its ability to enhance the durability of cement material. B. subtilis 168 was applied to the surface of cement specimens. The results showed a new layer of deposited organic-inorganic composites on the surface of the cement paste. In addition, the water permeability of the cement paste treated with B. subtilis 168 was lower than that of non-treated specimens. Furthermore, artificial cracks in the cement paste were completely remediated by the biodeposition of B. subtilis 168. The compressive strength of cement mortar treated with B. subtilis 168 increased by about 19.5% when compared with samples completed with only B4 medium. Taken together, these findings suggest that the biodeposition of B. subtilis 168 could be used as a sealing and coating agent to improve the strength and water resistance of concrete. This is the first paper to report the application of Bacillus subtilis 168 for its ability to improve the durability of cement mortar through calcium carbonate precipitation.

Tolerability, usability and acceptability of dissolving microneedle patch administration in human subjects

PubMed Central

Arya, Jaya; Henry, Sebastien; Kalluri, Haripriya; McAllister, Devin V.; Pewin, Winston P.; Prausnitz, Mark R.

2017-01-01

To support translation of microneedle patches from pre-clinical development into clinical trials, this study examined the effect of microneedle patch application on local skin reactions, reliability of use and acceptability to patients. Placebo patches containing dissolving microneedles were administered to fifteen human participants. Microneedle patches were well tolerated in the skin with no pain or swelling and only mild erythema localized to the site of patch administration that resolved fully within seven days. Microneedle patches could be administered by hand without the need of an applicator and delivery efficiencies were similar for investigator-administration and self-administration. Microneedle patch administration was not considered painful and the large majority of subjects were somewhat or fully confident that they self-administered patches correctly. Microneedle patches were overwhelmingly preferred over conventional needle and syringe injection. Altogether, these results demonstrate that dissolving microneedle patches were well tolerated, easily usable and strongly accepted by human subjects, which will facilitate further clinical translation of this technology. PMID:28285193

Pathogen transmission at stage-structured infectious patches: Killers and vaccinators.

PubMed

Caraco, Thomas; Turner, Wendy C

2018-01-07

Spatial localization of an obligate-killing, free-living pathogen generates a landscape of patches where new infections occur. As an infectious patch ages, both pathogen exposure at the patch and the probability of lethal infection following exposure can decline. We model stage-structured infectious patches, where non-lethal exposure can naturally "vaccinate" susceptible hosts. We let the between-stage difference in pathogen transmission, and then the between-stage difference in patch virulence, increase independently of other parameters. Effects of increasing either between-stage difference (about a fixed mean) depend on the probability a patch transitions from the first to second stage, i.e., the chance that a killer patch becomes a vaccinator. For slower stage transition, greater between-stage differences decreased susceptibles, and increased both resistant-host and killer patch numbers. But our examples reveal that each effect can be reversed when between-stage transition occurs more rapidly. For sufficiently rapid stage transition, increased between-stage virulence differences can lead to pathogen extinction, and leave the host at disease-free equilibrium. The model's general significance lies in demonstrating how epidemiological variation among sites of environmentally transmitted disease can strongly govern host-parasite dynamics. Copyright © 2017 Elsevier Ltd. All rights reserved.

Comparative experimental study of dynamic compressive strength of mortar with glass and basalt fibres

NASA Astrophysics Data System (ADS)

Kruszka, Leopold; Moćko, Wojciech; Fenu, Luigi; Cadoni, Ezio

2015-09-01

Specimen reinforced with glass and basalt fibers were prepared using Standard Portland cement (CEM I, 52.5 R as prescribed by EN 197-1) and standard sand, in accordance with EN 196-1. From this cementitious mixture, a reference cement mortar without fibers was first prepared. Compressive strength, modulus of elasticity, and mod of fracture were determined for all specimens. Static and dynamic properties were investigated using Instron testing machine and split Hopkinson pressure bar, respectively. Content of the glass fibers in the mortar does not influence the fracture stress at static loading conditions in a clearly observed way. Moreover at dynamic range 5% content of the fiber results in a significant drop of fracture stress. Analysis of the basalt fibers influence on the fracture stress shows that optimal content of this reinforcement is equal to 3% for both static and dynamic loading conditions. Further increase of the fiber share gives the opposite effect, i.e. drop of the fracture stress.

A novel method for a multi-level hierarchical composite with brick-and-mortar structure

PubMed Central

Brandt, Kristina; Wolff, Michael F. H.; Salikov, Vitalij; Heinrich, Stefan; Schneider, Gerold A.

2013-01-01

The fascination for hierarchically structured hard tissues such as enamel or nacre arises from their unique structure-properties-relationship. During the last decades this numerously motivated the synthesis of composites, mimicking the brick-and-mortar structure of nacre. However, there is still a lack in synthetic engineering materials displaying a true hierarchical structure. Here, we present a novel multi-step processing route for anisotropic 2-level hierarchical composites by combining different coating techniques on different length scales. It comprises polymer-encapsulated ceramic particles as building blocks for the first level, followed by spouted bed spray granulation for a second level, and finally directional hot pressing to anisotropically consolidate the composite. The microstructure achieved reveals a brick-and-mortar hierarchical structure with distinct, however not yet optimized mechanical properties on each level. It opens up a completely new processing route for the synthesis of multi-level hierarchically structured composites, giving prospects to multi-functional structure-properties relationships. PMID:23900554

A novel method for a multi-level hierarchical composite with brick-and-mortar structure.

PubMed

Brandt, Kristina; Wolff, Michael F H; Salikov, Vitalij; Heinrich, Stefan; Schneider, Gerold A

2013-01-01

The fascination for hierarchically structured hard tissues such as enamel or nacre arises from their unique structure-properties-relationship. During the last decades this numerously motivated the synthesis of composites, mimicking the brick-and-mortar structure of nacre. However, there is still a lack in synthetic engineering materials displaying a true hierarchical structure. Here, we present a novel multi-step processing route for anisotropic 2-level hierarchical composites by combining different coating techniques on different length scales. It comprises polymer-encapsulated ceramic particles as building blocks for the first level, followed by spouted bed spray granulation for a second level, and finally directional hot pressing to anisotropically consolidate the composite. The microstructure achieved reveals a brick-and-mortar hierarchical structure with distinct, however not yet optimized mechanical properties on each level. It opens up a completely new processing route for the synthesis of multi-level hierarchically structured composites, giving prospects to multi-functional structure-properties relationships.

A novel method for a multi-level hierarchical composite with brick-and-mortar structure

NASA Astrophysics Data System (ADS)

Brandt, Kristina; Wolff, Michael F. H.; Salikov, Vitalij; Heinrich, Stefan; Schneider, Gerold A.

2013-07-01

The fascination for hierarchically structured hard tissues such as enamel or nacre arises from their unique structure-properties-relationship. During the last decades this numerously motivated the synthesis of composites, mimicking the brick-and-mortar structure of nacre. However, there is still a lack in synthetic engineering materials displaying a true hierarchical structure. Here, we present a novel multi-step processing route for anisotropic 2-level hierarchical composites by combining different coating techniques on different length scales. It comprises polymer-encapsulated ceramic particles as building blocks for the first level, followed by spouted bed spray granulation for a second level, and finally directional hot pressing to anisotropically consolidate the composite. The microstructure achieved reveals a brick-and-mortar hierarchical structure with distinct, however not yet optimized mechanical properties on each level. It opens up a completely new processing route for the synthesis of multi-level hierarchically structured composites, giving prospects to multi-functional structure-properties relationships.

Hydration products and thermokinetic properties of cement-bentonite and cement-chalk mortars

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

Klyusov, A.A.

1988-08-20

Bentonite and chalk are the most popular auxiliary additives to portland cement for borehole cementation. The authors studied by physicochemical analysis methods (x-ray phase, derivatographic, and scanning and electron microscopy in combination with microdiffraction) the newly formed solid-phase composition of cement-bentonite and cement-chalk mortars (binder-additive ratio 9:1) prepared from portland cement for cold boreholes and 8% calcium chloride solution at a water-mixing ratio of 0.9. The mechanism of the influence of Ca-bentonite and chalk additives on the portland cement hydration rate was ascertained from the heat evolution rate curves. It was found that the phase compositions of the hydration productsmore » are represented in the studied systems by newly formed substances typical for portland cement. It has been noted that Ca-bentonite interacts with the calcium hydroxide of hydrated cement with the formation of hexagonal and cubic calcium hydroaluminates. Unlike Ca-bentonite, chalk does not react with portland cement at normal and reduced temperatures, does not block hydrated cement particles, which, in turn, ensures all other conditions remaining equal, a higher initial rate of hydration of cement-chalk mortar.« less

Integrated multiple patch-clamp array chip via lateral cell trapping junctions

NASA Astrophysics Data System (ADS)

Seo, J.; Ionescu-Zanetti, C.; Diamond, J.; Lal, R.; Lee, L. P.

2004-03-01

We present an integrated multiple patch-clamp array chip by utilizing lateral cell trapping junctions. The intersectional design of a microfluidic network provides multiple cell addressing and manipulation sites for efficient electrophysiological measurements at a number of patch sites. The patch pores consist of openings in the sidewall of a main fluidic channel, and a membrane patch is drawn into a smaller horizontal channel. This device geometry not only minimizes capacitive coupling between the cell reservoir and the patch channel, but also allows simultaneous optical and electrical measurements of ion channel proteins. Evidence of the hydrodynamic placement of mammalian cells at the patch sites as well as measurements of patch sealing resistance is presented. Device fabrication is based on micromolding of polydimethylsiloxane, thus allowing inexpensive mass production of disposable high-throughput biochips.

Orbital implant exposure treatment with porcine dermal collagen patching.

PubMed

Alwitry, A; Burns, S J; Abercrombie, L C

2006-09-01

To present a small case series of orbital implant exposures treated with porcine dermal collagen (Permacol, Tissue Science Laboratories PLC, Aldershot, Hants, UK) patching. A retrospective chart review of three cases of orbital implant exposure treated with Permacol patching. Three cases were identified. There were 4 operative episodes of Permacol patching (one socket had two attempts at permacol patching). In all 4 cases the patch rapidly failed and melted away leaving behind the orbital implant exposure. All 3 patients required implant removal. Orbital implant exposure remains a major long-term complication of evisceration and enucleation procedures. On the basis of our experience, we would not recommend using Permacol as a non-autologous material for covering exposed Medpor (Medpor, Porex Surgical, Atlanta, Georgia, USA) orbital implants. Further study is required to fully assess the safety and efficacy profile of Permacol in socket surgery.

Micro- and meso-scale pore structure in mortar in relation to aggregate content

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

Gao, Yun, E-mail: yun.gao@ugent.be; De Schutter, Geert; Ye, Guang

2013-10-15

Mortar is often viewed as a three-phase composite consisting of aggregate, bulk paste, and an interfacial transition zone (ITZ). However, this description is inconsistent with experimental findings because of the basic assumption that larger pores are only present within the ITZ. In this paper, we use backscattered electron (BSE) imaging to investigate the micro- and meso-scale structure of mortar with varying aggregate content. The results indicate that larger pores are present not only within the ITZ but also within areas far from aggregates. This phenomenon is discussed in detail based on a series of analytical calculations, such as the effectivemore » water binder ratio and the inter-aggregate spacing. We developed a modified computer model that includes a two-phase structure for bulk paste. This model interprets previous mercury intrusion porosimetry data very well. -- Highlights: •Based on BSE, we examine the HCSS model. •We develop the HCSS-DBLB model. •We use the modified model to interpret the MIP data.« less

Patch-based Convolutional Neural Network for Whole Slide Tissue Image Classification

PubMed Central

Hou, Le; Samaras, Dimitris; Kurc, Tahsin M.; Gao, Yi; Davis, James E.; Saltz, Joel H.

2016-01-01

Convolutional Neural Networks (CNN) are state-of-the-art models for many image classification tasks. However, to recognize cancer subtypes automatically, training a CNN on gigapixel resolution Whole Slide Tissue Images (WSI) is currently computationally impossible. The differentiation of cancer subtypes is based on cellular-level visual features observed on image patch scale. Therefore, we argue that in this situation, training a patch-level classifier on image patches will perform better than or similar to an image-level classifier. The challenge becomes how to intelligently combine patch-level classification results and model the fact that not all patches will be discriminative. We propose to train a decision fusion model to aggregate patch-level predictions given by patch-level CNNs, which to the best of our knowledge has not been shown before. Furthermore, we formulate a novel Expectation-Maximization (EM) based method that automatically locates discriminative patches robustly by utilizing the spatial relationships of patches. We apply our method to the classification of glioma and non-small-cell lung carcinoma cases into subtypes. The classification accuracy of our method is similar to the inter-observer agreement between pathologists. Although it is impossible to train CNNs on WSIs, we experimentally demonstrate using a comparable non-cancer dataset of smaller images that a patch-based CNN can outperform an image-based CNN. PMID:27795661

Nature and origin of white efflorescence on bricks, artificial stones, and joint mortars of modern houses evaluated by portable Raman spectroscopy and laboratory analyses

NASA Astrophysics Data System (ADS)

Morillas, Héctor; Maguregui, Maite; Trebolazabala, Josu; Madariaga, Juan Manuel

2015-02-01

Bricks and mortar currently constitute one of the most important building materials used in the construction of most modern facades. The deterioration of these materials is caused primarily by the impact of numerous external stressors, while poor manufacturing quality, particularly of mortars, can also contribute to this process. In this work, the non-invasive Raman spectroscopy technique was used to identify the recently formed deterioration compounds (primarily sulfates and nitrates) in bricks, artificial stones, and joint mortars from detached houses in the Bilbao metropolitan area (Basque Country, North of Spain), as well as to investigate the deterioration processes taking place in these materials. Additionally, to confirm and in some cases complement the results obtained with Raman spectroscopy, SEM-EDS and XRD measurements were also carried out.

Effect of Nano-CuO on Engineering and Microstructure Properties of Fibre-Reinforced Mortars Incorporating Metakaolin: Experimental and Numerical Studies

PubMed Central

Ghanei, Amir; Jafari, Faezeh; Mehrinejad Khotbehsara, Mojdeh; Mohseni, Ehsan; Cui, Hongzhi

2017-01-01

In this study, the effects of nano-CuO (NC) on engineering properties of fibre-reinforced mortars incorporating metakaolin (MK) were investigated. The effects of polypropylene fibre (PP) were also examined. A total of twenty-six mixtures were prepared. The experimental results were compared with numerical results obtained by adaptive neuro-fuzzy inference system (ANFIS) and Primal Estimated sub-GrAdient Solver for SVM (Pegasos) algorithm. Scanning Electron Microscope (SEM) was also employed to investigate the microstructure of the cement matrix. The mechanical test results showed that both compressive and flexural strengths of cement mortars decreased with the increase of MK content, however the strength values increased significantly with increasing NC content in the mixture. The water absorption of samples decreased remarkably with increasing NC particles in the mixture. When PP fibres were added, the strengths of cement mortars were further enhanced accompanied with lower water absorption values. The addition of 2 wt % and 3 wt % nanoparticles in cement mortar led to a positive contribution to strength and resistance to water absorption. Mixture of PP-MK10NC3 indicated the best results for both compressive and flexural strengths at 28 and 90 days. SEM images illustrated that the morphology of cement matrix became more porous with increasing MK content, but the porosity reduced with the inclusion of NC. In addition, it is evident from the SEM images that more cement hydration products adhered onto the surface of fibres, which would improve the fibre–matrix interface. The numerical results obtained by ANFIS and Pegasos were close to the experimental results. The value of R2 obtained for each data set (validate, test and train) was higher than 0.90 and the values of mean absolute percentage error (MAPE) and the relative root mean squared error (PRMSE) were near zero. The ANFIS and Pegasos models can be used to predict the mechanical properties and water

Dye-enhanced protein solders and patches in laser-assisted tissue welding.

PubMed

Small, W; Heredia, N J; Maitland, D J; Da Silva, L B; Matthews, D L

1997-01-01

This study examines the use of dye-enhanced protein bonding agents in 805 nm diode laser-assisted tissue welding. A comparison of an albumin liquid solder and collagen solid-matrix patches used to repair arteriotomies in an in vitro porcine model is presented. Extrinsic bonding media in the form of solders and patches have been used to enhance the practice of laser tissue welding. Preferential absorption of the laser wavelength has been achieved by the incorporation of chromophores. Both the solder and the patch included indocyanine green dye (ICG) to absorb the 805 nm continuous-wave diode laser light used to perform the welds. Solder-mediated welds were divided into two groups (high power/short exposure and low power/long exposure), and the patches were divided into three thickness groups ranging from 0.1 to 1.3 mm. The power used to activate the patches was constant, but the exposure time was increased with patch thickness. Burst pressure results indicated that solder-mediated and patched welds yielded similar average burst strengths in most cases, but the patches provided a higher success rate (i.e., more often exceeded 150 mmHg) and were more consistent (i.e., smaller standard deviation) than the solder. The strongest welds were obtained using 1.0-1.3 mm thick patches, while the high power/short exposure solder group was the weakest. Though the solder and patches yielded similar acute weld strengths, the solid-matrix patches facilitated the welding process and provided consistently strong welds. The material properties of the extrinsic agents influenced their performance.

Estimation of local stresses and elastic properties of a mortar sample by FFT computation of fields on a 3D image

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

Escoda, J.; Departement Materiaux et Mecanique des Composants, Electricite de France, Moret-sur-Loing; Willot, F., E-mail: francois.willot@ensmp.f

2011-05-15

This study concerns the prediction of the elastic properties of a 3D mortar image, obtained by micro-tomography, using a combined image segmentation and numerical homogenization approach. The microstructure is obtained by segmentation of the 3D image into aggregates, voids and cement paste. Full-fields computations of the elastic response of mortar are undertaken using the Fast Fourier Transform method. Emphasis is made on highly-contrasted properties between aggregates and matrix, to anticipate needs for creep or damage computation. The representative volume element, i.e. the volume size necessary to compute the effective properties with a prescribed accuracy, is given. Overall, the volumes usedmore » in this work were sufficient to estimate the effective response of mortar with a precision of 5%, 6% and 10% for contrast ratios of 100, 1000 and 10,000, resp. Finally, a statistical and local characterization of the component of the stress field parallel to the applied loading is carried out.« less

SEM/EDX and vis spectrophotometry study of the stability of resin-bound mortars used for casting replicas and filling missing parts of historic stone fountains.

PubMed

Roig-Salom, José-Luis; Doménech-Carbó, María-Teresa; de la Cruz-Cañizares, Juana; Bolívar-Galiano, Fernando; Pelufo-Carbonell, María-José; Peraza-Zurita, Yaiza

2003-04-01

A study by SEM/EDX and spectrophotometry in the visible region attempting to assess the stability of new resin-bound mortars used for casting replicas of marble historic fountains is presented in this paper. Different accelerating tests such as thermal ageing, UV light ageing, ageing in an SO(2) pollutant chamber, freezing cycles ageing, salt crystallisation ageing, natural ageing and biological attack have been applied to a series of test specimens prepared with polyester-, epoxy- and gel-coat-bound mortars. Examination of morphology, measurement of chemical composition and chromatic coordinates before and after ageing treatments establish the higher stability and resistance properties of these resin-bound mortars by comparison to those from the natural marbles.

Monocular Patching May Induce Ipsilateral “Where” Spatial Bias

PubMed Central

Chen, Peii; Erdahl, Lillian; Barrett, Anna M.

2009-01-01

Spatial bias is an asymmetry of perception and/or representation of spatial information —“where” bias —, or of spatially directed actions — “aiming” bias. A monocular patch may induce contralateral “where” spatial bias (the Sprague effect; Sprague (1966) Science, 153, 1544–1547). However, an ipsilateral patch-induced spatial bias may be observed if visual occlusion results in top-down, compensatory re-allocation of spatial perceptual or representational resources toward the region of visual deprivation. Tactile distraction from a monocular patch may also contribute to an ipsilateral bias. To examine these hypotheses, neurologically normal adults bisected horizontal lines at baseline without a patch, while wearing a monocular patch, and while wearing tactile-only and visual-only monocular occlusion. We fractionated “where” and “aiming” spatial bias components using a video apparatus to reverse visual feedback for half of the test trials. The results support monocular patch-induced ipsilateral “where” spatial errors, which are not consistent with the Sprague effect. Further, the present findings suggested that the induced ipsilateral bias may be primarily induced by visual deprivation, consistent with compensatory “where” resource re-allocation. PMID:19100274

Exp 36 Patch Final

NASA Image and Video Library

2012-08-10

ISS036-S-001 (January 2012) --- The dynamic design of the Expedition 36 patch portrays the International Space Station?s (ISS) iconic solar arrays. The slanted angles denote a kinetic energy leading from the Earth in the lower right to the upper left tip of the triangular shape of the patch, representing the infinite scientific research, education, and long-duration spaceflight capabilities the ISS provides with each mission, as well as our goal for future exploration beyond the Space Station. The numbers 3 and 6 harmoniously intertwine to form expedition number 36 and its gray coloration signifies the unity and neutrality among all of the international partners of the ISS. The blue and gold color scheme of the patch represents the subtle way the central gold orbit wraps around the number 36 to form a trident at its lower right tip. The trident also symbolizes the sea, air, and land, all of which make up the Earth from where the trident originates in the design. The NASA insignia design for shuttle and space station flights is reserved for use by the astronauts and for other official use as the NASA Administrator may authorize. Public availability has been approved only in the form of illustrations by the various news media. When and if there is any change in this policy, which is not anticipated, it will be publicly announced. Photo credit: NASA

Habitat patch size and nesting success of yellow-breasted chats

Treesearch

Dick E. Burhans; Frank R. Thompson III

1999-01-01

We measured vegetation at shrub patches used for nesting by Yellow-breasted Chats (Icteria virens) to evaluate the importance of nesting habitat patch features on nest predation, cowbird parasitism, and nest site selection. Logistic regression models indicated that nests in small patches (average diameter

Results of patch testing in 10 patients with peristomal dermatitis.

PubMed

Landis, Megan N; Keeling, James H; Yiannias, James A; Richardson, Donna M; Nordberg Linehan, Diane L; Davis, Mark D P

2012-09-01

Peristomal dermatitis is a common problem in patients with ostomies that is a source of considerable morbidity. Irritant contact dermatitis is most common, but allergic contact dermatitis can also occur. Because of the lack of published reports on patch testing for this indication, we undertook a retrospective study of patch testing results in patients with suspected peristomal allergic contact dermatitis. We sought to describe our patch testing experience with patients referred with peristomal dermatitis. This was a retrospective review of medical records of patients with ostomies and peristomal dermatitis who underwent patch testing in the Mayo Clinic Departments of Dermatology in Jacksonville, FL; Rochester, MN; and Scottsdale, AZ, during a 10-year period (2000-2010). Ten patients with peristomal dermatitis were referred for patch testing (6 in Minnesota, 2 in Florida, and 2 in Arizona). Patients were patch tested to the materials used in their stoma devices, to the standard series, and in some cases to supplemental series. All 10 had at least one allergic patch test reaction, most commonly to stoma paste (3 of 10 patients). Retrospective nature of study via chart review is a limitation. Patch testing is a useful tool for identification of allergens in patients with peristomal dermatitis. Copyright © 2011 American Academy of Dermatology, Inc. Published by Mosby, Inc. All rights reserved.

Patch-test reactions to plastic and glue allergens.

PubMed

Kanerva, L; Jolanki, R; Alanko, K; Estlander, T

1999-07-01

Plastics and glues are common causes of occupational dermatoses, but only few reports have dealt with patch-test reactions caused by plastic and glue allergens. Patients exposed to plastics and remitted to an occupational dermatology clinic, were patch-tested with 50-53 plastic and glue allergens during a 6-year period. Conventional patch-test techniques were used. The most common causes of allergic patch-test reactions in 360 patients were novolac epoxy resin (5.1%), phenol formaldehyde resin (3.1%), 4-tert-butylcatechol (2.6%), phenyl glycidyl ether (2.6%), diaminodiphenyl methane (2.2%), benzoyl peroxide (2.2%), hexamethylene tetramine (2.0%) and o-cresyl glycidyl ether (1.6%). The allergens that most often elicited irritant patch-test reactions were: benzoyl peroxide (9.5%), abitol alcohol (3.6%), hydroquinone (3.1%), acid-catalyzed phenol formaldehyde resin (2.5%) and toluene diisocyanate (1.9%). Twenty-six out of 53 chemicals caused no allergic reaction during the 6-year period. Plastic allergens in the standard series provoked allergic reactions with formaldehyde (5.8%), diglycidyl ether of bisphenol A (3.2%), 4-tert-butylphenol-formaldehyde-resin (1.1%), toluene sulphonamide formaldehyde-resin (1.1%) and triethylenglycol diacrylate (0.4%). Although half of the plastic chemicals gave no allergic patch-test reactions during a 6-year period, with unusual allergens this low yield needs to be accepted, because otherwise rare allergies will not be detected. Also a negative reaction has diagnostic value.

Periodic creation of polar cap patches from auroral transients in the cusp

NASA Astrophysics Data System (ADS)

Hosokawa, K.; Taguchi, S.; Ogawa, Y.

2016-06-01

On 24 November 2012, an interval of polar cap patches was identified by an all-sky airglow imager located near the dayside cusp. During the interval, the successive appearance of poleward moving auroral forms (PMAFs) was detected, which are known to represent ionospheric manifestations of pulsed magnetic reconnections at the dayside magnetopause. All of the patches observed during the interval appeared from these transient auroral features (i.e., there was a one-to-one correspondence between PMAFs and newly created baby patches). This fact strongly suggests that patches can be directly and seamlessly created from a series of PMAFs. The optical intensities of the baby patches were 100-150 R, which is slightly lower than typical patch luminosity on the nightside and may imply that PMAF-induced patches are generally low density. The generation of such patches could be explained by impact ionization due to soft particle precipitation into PMAFs traces. In spite of the faint signature of the baby patches, two coherent HF radars of the SuperDARN network observed backscatter echoes in the central polar cap, which represented signatures of plasma irregularities associated with the baby patches. These indicate that patches created from PMAFs have the potential to affect the satellite communications environment in the central polar cap region.

Effect of novel mucoadhesive buccal patches of carvedilol on isoprenaline-induced tachycardia

PubMed Central

Verma, Navneet; Chattopadhyay, Pronobesh

2014-01-01

The main aim of the study was designed to develop bioadhesive buccal patches of carvedilol (CR) and evaluate for isoprenaline-induced tachycardia. Buccal patches of carvedilol were prepared by using chitosan (CH), sodium salt of carboxy methyl cellulose (NaCMC), and polyvinyl alcohol (PVA) as mucoadhesive polymers. The solvent evaporation method was used for the preparation of buccal patches. The patches were evaluated for their physical characteristics like patch thickness, weight variation, content uniformity, folding endurance, surface pH, residence time, in vitro drug release, and in vivo pharmacodynamic study. The swelling index of the patches was found to be proportional to the polymer concentration, whereas surface pH of all the formulated bioadhesive patches was found to lie between neutral ranges. In-vitro release study shows that 94.75% drug was release in 8 hours from the patch, which containing 2% w/v chitosan. The folding endurance result shows good elasticity in all the patches. Application of buccal patches on buccal mucosa of rabbit shows a significant result in % inhibition of isoprenaline-induced tachycardia. Prepared buccal patches of chitosan, NaCMC, and PVA containing Carvedilol meet the ideal requirement for the delivery of cardiovascular drugs and inhibit the isoprenaline tachycardia. PMID:24959419

Effect of novel mucoadhesive buccal patches of carvedilol on isoprenaline-induced tachycardia.

PubMed

Verma, Navneet; Chattopadhyay, Pronobesh

2014-04-01

The main aim of the study was designed to develop bioadhesive buccal patches of carvedilol (CR) and evaluate for isoprenaline-induced tachycardia. Buccal patches of carvedilol were prepared by using chitosan (CH), sodium salt of carboxy methyl cellulose (NaCMC), and polyvinyl alcohol (PVA) as mucoadhesive polymers. The solvent evaporation method was used for the preparation of buccal patches. The patches were evaluated for their physical characteristics like patch thickness, weight variation, content uniformity, folding endurance, surface pH, residence time, in vitro drug release, and in vivo pharmacodynamic study. The swelling index of the patches was found to be proportional to the polymer concentration, whereas surface pH of all the formulated bioadhesive patches was found to lie between neutral ranges. In-vitro release study shows that 94.75% drug was release in 8 hours from the patch, which containing 2% w/v chitosan. The folding endurance result shows good elasticity in all the patches. Application of buccal patches on buccal mucosa of rabbit shows a significant result in % inhibition of isoprenaline-induced tachycardia. Prepared buccal patches of chitosan, NaCMC, and PVA containing Carvedilol meet the ideal requirement for the delivery of cardiovascular drugs and inhibit the isoprenaline tachycardia.

Reproducible, high performance patch antenna array apparatus and method of fabrication

DOEpatents

Strassner, II, Bernd H.

2007-01-23

A reproducible, high-performance patch antenna array apparatus includes a patch antenna array provided on a unitary dielectric substrate, and a feed network provided on the same unitary substrate and proximity coupled to the patch antenna array. The reproducibility is enhanced by using photolithographic patterning and etching to produce both the patch antenna array and the feed network.

Reconfigurable Wideband Circularly Polarized Stacked Square Patch Antenna for Cognitive Radios

NASA Technical Reports Server (NTRS)

Barbosa Kortright, Miguel A.; Waldstein, Seth W.; Simons, Rainee N.

2017-01-01

An almost square patch, a square patch and a stacked square patch with corner truncation for circular polarization (CP) are researched and developed at X-band for cognitive radios. Experimental results indicate, first, that the impedance bandwidth of a CP almost square patch fed from the edge by a 50 ohm line is 1.70% and second, that of a CP square patch fed from the ground plane side by a surface launch connector is 1.87%. Third, the impedance bandwidth of a CP stacked square patch fed by a surface launch connector is 2.22%. The measured center frequency for the CP square patch fed by a surface launch connector without and with an identical stacked patch is 8.45 and 8.1017 GHz, respectively. By stacking a patch, separated by a fixed air gap of 0.254 mm, the center frequency is observed to shift by as much as 348.3 MHz. The shift in center frequency, brought about by the reconfiguring of the physical layer antenna, can be exploited in a cognitive system since it expands the usable frequency spectrum for software reconfiguration in the presence of interference. In addition, varying the fixed air gap in the stacked antenna geometry by increments of 0.254 mm further expands the usable frequency spectrum.

The effects of facilitation and competition on group foraging in patches

PubMed Central

Laguë, Marysa; Tania, Nessy; Heath, Joel; Edelstein-Keshet, Leah

2012-01-01

Significant progress has been made towards understanding the social behaviour of animal groups, but the patch model, a foundation of foraging theory, has received little attention in a social context. The effect of competition on the optimal time to leave a foraging patch was considered as early as the original formulation of the marginal value theorem, but surprisingly, the role of facilitation (where foraging in groups decreases the time to find food in patches), has not been incorporated. Here we adapt the classic patch model to consider how the trade-off between facilitation and competition influence optimal group size. Using simple assumptions about the effect of group size on the food-finding time and the sharing of resources, we find conditions for existence of optima in patch residence time and in group size. When patches are close together (low travel times), larger group sizes are optimal. Groups are predicted to exploit patches differently than individual foragers and the degree of patch depletion at departure depends on the details of the trade-off between competition and facilitation. A variety of currencies and group-size effects are also considered and compared. Using our simple formulation, we also study the effects of social foraging on patch exploitation which to date have received little empirical study. PMID:22743132

Biophysics and Structure of the Patch and the Gigaseal

PubMed Central

Suchyna, Thomas M.; Markin, Vladislav S.; Sachs, Frederick

2009-01-01

Abstract Interpreting channel behavior in patches requires an understanding of patch structure and dynamics, especially in studies of mechanosensitive channels. High resolution optical studies show that patch formation occurs via blebbing that disrupts normal membrane structure and redistributes in situ components including ion channels. There is a 1–2 μm region of the seal below the patch where proteins are excluded and this may consist of extracted lipids that form the gigaseal. Patch domes often have complex geometries with inhomogeneous stresses due to the membrane-glass adhesion energy (Ea), cytoskeletal forces, and possible lipid subdomains. The resting tension in the patch dome ranges from 1–4 mN/m, a significant fraction of the lytic tension of a bilayer (∼10 mN/m). Thus, all patch experiments are conducted under substantial, and uneven, resting tension that may alter the kinetics of many channels. Ea seems dominated by van der Waals attraction overlaid with a normally repulsive Coulombic force. High ionic strength pipette saline increased Ea and, surprisingly, increased cytoskeletal rigidity in cell-attached patches. Low pH pipette saline also increased Ea and reduced the seal selectivity for cations, presumably by neutralizing the membrane surface charge. The seal is a negatively charged, cation selective, space with a resistance of ∼7 gigohm/μm in 100 mM KCl, and the high resistivity of the space may result from the presence of high viscosity glycoproteins. Patches creep up the pipette over time with voltage independent and voltage dependent components. Voltage-independent creep is expected from the capillary attraction of Ea and the flow of fresh lipids from the cell. Voltage-dependent creep seems to arise from electroosmosis in the seal. Neutralization of negative charges on the seal membrane with low pH decreased the creep rate and reversed the direction of creep at positive pipette potentials. PMID:19651032

Grassland Fire and Cattle Grazing Regulate Reptile and Amphibian Assembly Among Patches

NASA Astrophysics Data System (ADS)

Larson, Danelle M.

2014-12-01

Fire and grazing are common management schemes of grasslands globally and are potential drivers of reptilian and amphibian (herpetofauna) metacommunity dynamics. Few studies have assessed the impacts of fire and cattle grazing on herpetofauna assemblages in grasslands. A patch-burn grazing study at Osage Prairie, MO, USA in 2011-2012 created landscape patches with treatments of grazing, fire, and such legacies. Response variables were measured before and after the application of treatments, and I used robust-design occupancy modeling to estimate patch occupancy and detection rate within patches, and recolonization and extinction (i.e., dispersal) across patches. I conducted redundancy analysis and a permuted multivariate analysis of variance to determine if patch type and the associated environmental factors explained herpetofauna assemblage. Estimates for reptiles indicate that occupancy was seasonally constant in Control patches ( ψ ~ 0.5), but declined to ψ ~ 0.15 in patches following the applications of fire and grazing. Local extinctions for reptiles were higher in patches with fire or light grazing ( ɛ ~ 0.7) compared to the controls. For the riparian herpetofaunal community, patch type and grass height were important predictors of abundance; further, the turtles, lizards, snakes, and adult amphibians used different patch types. The aquatic amphibian community was predicted by watershed and in-stream characteristics, irrespective of fire or grazing. The varying responses from taxonomic groups demonstrate habitat partitioning across multiple patch types undergoing fire, cattle grazing, and legacy effects. Prairies will need an array of patch types to accommodate multiple herpetofauna species.

Skin patch and vaginal ring versus combined oral contraceptives for contraception.

PubMed

Lopez, Laureen M; Grimes, David A; Gallo, Maria F; Stockton, Laurie L; Schulz, Kenneth F

2013-04-30

The delivery of combination contraceptive steroids from a transdermal contraceptive patch or a contraceptive vaginal ring offers potential advantages over the traditional oral route. The transdermal patch and vaginal ring could require a lower dose due to increased bioavailability and improved user compliance. To compare the contraceptive effectiveness, cycle control, compliance (adherence), and safety of the contraceptive patch or the vaginal ring versus combination oral contraceptives (COCs). Through February 2013, we searched MEDLINE, POPLINE, CENTRAL, LILACS, ClinicalTrials.gov, and ICTRP for trials of the contraceptive patch or the vaginal ring. Earlier searches also included EMBASE. For the initial review, we contacted known researchers and manufacturers to identify other trials. We considered randomized controlled trials comparing a transdermal contraceptive patch or a contraceptive vaginal ring with a COC. Data were abstracted by two authors and entered into RevMan. For dichotomous variables, the Peto odds ratio (OR) with 95% confidence intervals (CI) was calculated. For continuous variables, the mean difference was computed. We also assessed the quality of evidence for this review. We found 18 trials that met our inclusion criteria. Of six patch studies, five examined the marketed patch containing norelgestromin plus ethinyl estradiol (EE); one studied a patch in development that contains levonorgestrel (LNG) plus EE. Of 12 vaginal ring trials, 11 examined the same marketing ring containing etonogestrel plus EE; one studied a ring being developed that contains nesterone plus EE.Contraceptive effectiveness was not significantly different for the patch or ring versus the comparison COC. Compliance data were limited. Patch users showed better compliance than COC users in three trials. For the norelgestromin plus EE patch, ORs were 2.05 (95% CI 1.83 to 2.29) and 2.76 (95% CI 2.35 to 3.24). In the levonorgestrel plus EE patch report, patch users were less

The modeling of piezoceramic patch interactions with shells, plates and beams

NASA Technical Reports Server (NTRS)

Banks, H. T.; Smith, R. C.

1992-01-01

General models describing the interactions between a pair of piezoceramic patches and elastic substructures consisting of a cylindrical shell, plate and beam are presented. In each case, the manner in which the patch loads enter both the strong and weak forms of the time-dependent structural equations of motion is described. Through force and moment balancing, these loads are then determined in terms of material properties of the patch and substructure (thickness, elastic properties, Poisson ratios), the geometry of the patch placement, and the voltages into the patches. In the case of the shell, the coupling between banding and inplane deformations, which is due to the curvature, is retained. These models are sufficiently general to allow for potentially different patch voltages which implies that they can be suitably employed when using piezoceramic patches for controlling system dynamics when both extensional and bending vibrations are present.

Cost effectiveness of the Oregon quitline "free patch initiative".

PubMed

Fellows, Jeffrey L; Bush, Terry; McAfee, Tim; Dickerson, John

2007-12-01

We estimated the cost effectiveness of the Oregon tobacco quitline's "free patch initiative" compared to the pre-initiative programme. Using quitline utilisation and cost data from the state, intervention providers and patients, we estimated annual programme use and costs for media promotions and intervention services. We also estimated annual quitline registration calls and the number of quitters and life years saved for the pre-initiative and free patch initiative programmes. Service utilisation and 30-day abstinence at six months were obtained from 959 quitline callers. We compared the cost effectiveness of the free patch initiative (media and intervention costs) to the pre-initiative service offered to insured and uninsured callers. We conducted sensitivity analyses on key programme costs and outcomes by estimating a best case and worst case scenario for each intervention strategy. Compared to the pre-intervention programme, the free patch initiative doubled registered calls, increased quitting fourfold and reduced total costs per quit by $2688. We estimated annual paid media costs were $215 per registered tobacco user for the pre-initiative programme and less than $4 per caller during the free patch initiative. Compared to the pre-initiative programme, incremental quitline promotion and intervention costs for the free patch initiative were $86 (range $22-$353) per life year saved. Compared to the pre-initiative programme, the free patch initiative was a highly cost effective strategy for increasing quitting in the population.

The art and science of mission patches and their origins in society

NASA Astrophysics Data System (ADS)

Brumfitt, A.; Thompson, L. A.; Raitt, D.

2008-06-01

Space exploration utilizes some of the latest and highest technology available to human kind; synonymous with space exploration is the mission patch. This specialized art form popularizes the exploration of space with millions of mission patches sold around the world. Space tourism and education centres like the Kennedy Space Centre rely heavily on each space shuttle launch to support their merchandising of mission patches, from the traditional sew on badge to T shirts. Do mission patches tell a story? Are they Art? What is the origin and role of this art form in society? The art form of space mission patches combines the 21st century relevance with heraldic origins predating the ninth century. The space mission patch is designed by the astronauts themselves if it is a manned mission. As an education tool teachers and educators use the space mission patch to engage their students in the excitement of space exploration, the mission patch design is utilized as an education tool in literature, science and art. The space mission patch is a particularly powerful message medium. This paper looks at the origins of the space mission patch, its relevance to art and its impact on society.

Experimental patch testing with chromium-coated materials.

PubMed

Bregnbak, David; Thyssen, Jacob P; Jellesen, Morten S; Zachariae, Claus; Johansen, Jeanne D

2017-06-01

Chromium coatings on metal alloys can be decorative, and prevent corrosion and metal ion release. We recently showed that handling of a chromium-containing disc resulted in chromium deposition on the skin. To examine patch test reactivity to chromium-coated discs. We included 15 patients: 10 chromium-allergic patients, and 5 patients without chromium allergy. All were patch tested with potassium dichromate, cobalt chloride, nickel sulfate, and nine different metallic discs. The chromium-allergic patients were also patch tested with serial dilutions of potassium dichromate. Positive/weaker reactions were observed to disc B (1 of 10), disc C (1 of 10), and disc D, disc E, and disc I (4 of 10 each). As no controls reacted to any of the discs, the weak reactions indicate allergic reactions. Positive patch test reactions to 1770 ppm chromium(VI) in the serial dilutions of potassium dichromate were observed in 7 of 10 patients. When the case group was narrowed down to include only the patients with a current positive patch test reaction to potassium dichromate, elicitation of dermatitis by both chromium(III) and chromium(VI) discs was observed in 4 of 7 of patients. Many of the patients reacted to both chromium(III) and chromium(VI) surfaces. Our results indicate that both chromium(VI) and chromium(III) pose a risk to chromium-allergic patients. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Surface patterning of nanoparticles with polymer patches

NASA Astrophysics Data System (ADS)

Choueiri, Rachelle M.; Galati, Elizabeth; Thérien-Aubin, Héloïse; Klinkova, Anna; Larin, Egor M.; Querejeta-Fernández, Ana; Han, Lili; Xin, Huolin L.; Gang, Oleg; Zhulina, Ekaterina B.; Rubinstein, Michael; Kumacheva, Eugenia

2016-10-01

Patterning of colloidal particles with chemically or topographically distinct surface domains (patches) has attracted intense research interest. Surface-patterned particles act as colloidal analogues of atoms and molecules, serve as model systems in studies of phase transitions in liquid systems, behave as ‘colloidal surfactants’ and function as templates for the synthesis of hybrid particles. The generation of micrometre- and submicrometre-sized patchy colloids is now efficient, but surface patterning of inorganic colloidal nanoparticles with dimensions of the order of tens of nanometres is uncommon. Such nanoparticles exhibit size- and shape-dependent optical, electronic and magnetic properties, and their assemblies show new collective properties. At present, nanoparticle patterning is limited to the generation of two-patch nanoparticles, and nanoparticles with surface ripples or a ‘raspberry’ surface morphology. Here we demonstrate nanoparticle surface patterning, which utilizes thermodynamically driven segregation of polymer ligands from a uniform polymer brush into surface-pinned micelles following a change in solvent quality. Patch formation is reversible but can be permanently preserved using a photocrosslinking step. The methodology offers the ability to control the dimensions of patches, their spatial distribution and the number of patches per nanoparticle, in agreement with a theoretical model. The versatility of the strategy is demonstrated by patterning nanoparticles with different dimensions, shapes and compositions, tethered with various types of polymers and subjected to different external stimuli. These patchy nanocolloids have potential applications in fundamental research, the self-assembly of nanomaterials, diagnostics, sensing and colloidal stabilization.

Impedance Spectroscopy Study of the Effect of Environmental Conditions on the Microstructure Development of Sustainable Fly Ash Cement Mortars.

PubMed

Ortega, José Marcos; Sánchez, Isidro; Climent, Miguel Ángel

2017-09-25

Today, the characterisation of the microstructure of cement-based materials using non-destructive techniques has become an important topic of study, and among them, the impedance spectroscopy has recently experienced great progress. In this research, mortars with two different contents of fly ash were exposed to four different constant temperature and relative humidity environments during a 180-day period. The evolution of their microstructure was studied using impedance spectroscopy, whose results were contrasted with mercury intrusion porosimetry. The hardening environment has an influence on the microstructure of fly ash cement mortars. On one hand, the impedance resistances R₁ and R₂ are more influenced by the drying of the materials than by microstructure development, so they are not suitable for following the evolution of the porous network under non-optimum conditions. On the other hand, the impedance spectroscopy capacitances C₁ and C₂ allow studying the microstructure development of fly ash cement mortars exposed to those conditions, and their results are in accordance with mercury intrusion porosimetry ones. Finally, it has been observed that the combined analysis of the abovementioned capacitances could be very useful for studying shrinkage processes in cement-based materials kept in low relative humidity environments.

An Electronic Patch for wearable health monitoring by reflectance pulse oximetry.

PubMed

Haahr, Rasmus G; Duun, Sune B; Toft, Mette H; Belhage, Bo; Larsen, Jan; Birkelund, Karen; Thomsen, Erik V

2012-02-01

We report the development of an Electronic Patch for wearable health monitoring. The Electronic Patch is a new health monitoring system incorporating biomedical sensors, microelectronics, radio frequency (RF) communication, and a battery embedded in a 3-dimensional hydrocolloid polymer. In this paper the Electronic Patch is demonstrated with a new optical biomedical sensor for reflectance pulse oximetry so that the Electronic Patch in this case can measure the pulse and the oxygen saturation. The reflectance pulse oximetry solution is based on a recently developed annular backside silicon photodiode to enable low power consumption by the light emitting components. The Electronic Patch has a disposable part of soft adhesive hydrocolloid polymer and a reusable part of hard polylaurinlactam. The disposable part contains the battery. The reusable part contains the reflectance pulse oximetry sensor and microelectronics. The reusable part is 'clicked' into the disposable part when the patch is prepared for use. The patch has a size of 88 mm by 60 mm and a thickness of 5 mm.

Nature and origin of white efflorescence on bricks, artificial stones, and joint mortars of modern houses evaluated by portable Raman spectroscopy and laboratory analyses.

PubMed

Morillas, Héctor; Maguregui, Maite; Trebolazabala, Josu; Madariaga, Juan Manuel

2015-02-05

Bricks and mortar currently constitute one of the most important building materials used in the construction of most modern facades. The deterioration of these materials is caused primarily by the impact of numerous external stressors, while poor manufacturing quality, particularly of mortars, can also contribute to this process. In this work, the non-invasive Raman spectroscopy technique was used to identify the recently formed deterioration compounds (primarily sulfates and nitrates) in bricks, artificial stones, and joint mortars from detached houses in the Bilbao metropolitan area (Basque Country, North of Spain), as well as to investigate the deterioration processes taking place in these materials. Additionally, to confirm and in some cases complement the results obtained with Raman spectroscopy, SEM-EDS and XRD measurements were also carried out. Copyright © 2014 Elsevier B.V. All rights reserved.

Scale-dependent feedbacks between patch size and plant reproduction in desert grassland

USGS Publications Warehouse

Svejcar, Lauren N.; Bestelmeyer, Brandon T.; Duniway, Michael C.; James, Darren K.

2015-01-01

Theoretical models suggest that scale-dependent feedbacks between plant reproductive success and plant patch size govern transitions from highly to sparsely vegetated states in drylands, yet there is scant empirical evidence for these mechanisms. Scale-dependent feedback models suggest that an optimal patch size exists for growth and reproduction of plants and that a threshold patch organization exists below which positive feedbacks between vegetation and resources can break down, leading to critical transitions. We examined the relationship between patch size and plant reproduction using an experiment in a Chihuahuan Desert grassland. We tested the hypothesis that reproductive effort and success of a dominant grass (Bouteloua eriopoda) would vary predictably with patch size. We found that focal plants in medium-sized patches featured higher rates of grass reproductive success than when plants occupied either large patch interiors or small patches. These patterns support the existence of scale-dependent feedbacks in Chihuahuan Desert grasslands and indicate an optimal patch size for reproductive effort and success in B. eriopoda. We discuss the implications of these results for detecting ecological thresholds in desert grasslands.

The effects of facilitation and competition on group foraging in patches.

PubMed

Laguë, Marysa; Tania, Nessy; Heath, Joel; Edelstein-Keshet, Leah

2012-10-07

Significant progress has been made towards understanding the social behaviour of animal groups, but the patch model, a foundation of foraging theory, has received little attention in a social context. The effect of competition on the optimal time to leave a foraging patch was considered as early as the original formulation of the marginal value theorem, but surprisingly, the role of facilitation (where foraging in groups decreases the time to find food in patches), has not been incorporated. Here we adapt the classic patch model to consider how the trade-off between facilitation and competition influences optimal group size. Using simple assumptions about the effect of group size on the food-finding time and the sharing of resources, we find conditions for existence of optima in patch residence time and in group size. When patches are close together (low travel times), larger group sizes are optimal. Groups are predicted to exploit patches differently than individual foragers and the degree of patch depletion at departure depends on the details of the trade-off between competition and facilitation. A variety of currencies and group-size effects are also considered and compared. Using our simple formulation, we also study the effects of social foraging on patch exploitation which to date have received little empirical study. Copyright © 2012 Elsevier Ltd. All rights reserved.

A fatal outcome after unintentional overdosing of rivastigmine patches.

PubMed

Lövborg, Henrik; Jönsson, Anna K; Hägg, Staffan

2012-02-01

Rivastigmine is an acetylcholine esterase inhibitor used in the treatment of dementia. Patches with rivastigmine for transdermal delivery have been used to increase compliance and to reduce side effects. We describe an 87-year old male with dementia treated with multiple rivastigmine patches (Exelon 9,5 mg/24 h) who developed nausea, vomiting and renal failure with disturbed electrolytes resulting in death. The symptoms occurred after six rivastigmine patches had concomitantly been erroneously applied by health care personnel on two consecutive days. The terminal cause of death was considered to be uremia from an acute tubular necrosis that was assessed as a result of dehydration through vomiting. The rivastigmine intoxication was assessed as having caused or contributed to the dehydrated condition. The medication error occurred at least partly due to ambiguous labeling. The clinical signs were not initially recognized as adverse effects of rivastigmine. The presented case is a description of a rivastigmine overdose due to a medication error involving patches. This case indicates the importance of clear and unambiguous instructions to avoid administration errors with patches and to be vigilant to adverse drug reactions for early detection and correction of drug administration errors. In particular, instructions clearly indicating that only one patch should be applied at a time are important.

[Continued Use of Rotigotine Transdermal Patches for Parkinson Disease].

PubMed

Yasutaka, Yuki; Fujioka, Shinsuke; Shibaguchi, Hirotomo; Imakyure, Osamu; Washiyama, Atsushi; Tsuboi, Yoshio; Futagami, Koujiro

2016-06-01

Transdermal patches containing rotigotine, a dopamine agonist (DA) for treatment of Parkinson disease, continuously exert stable effects when applied once daily. Therefore, they are expected to reduce the patient burdens due to complications such as wearing-off and dysphagia. However, dosing is occasionally reduced or discontinued after application because of several reasons such as skin reactions or unsatisfactory efficacy. To identify the risk factors involved in the reduced or discontinued use of rotigotine patches, a retrospective study was conducted with reference to the medical records of patients with Parkinson disease who received rotigotine patches in our hospital. 85 patients were involved in this study. Dosing of rotigotine was reduced or discontinued in 53 patients during the study period. The factors associated with charges in treatment included combination therapy with clonazepam and oral administration of another DA before the application of rotigotine. The reduction or discontinuation rate of rotigotine patches in patients who reduced the equivalent dose of DA on the introduction of rotigotine patches was 94.7%, showing a significantly higher rate compared with 61.3% in the increased dose group. To improve adherence to rotigotine patch therapy, physicians need to carefully consider concomitant drugs and total dose of DAs. (Received December 7, 2015; Accepted February 22, 2016; Published June 1, 2016).

Effect of boron waste on the properties of mortar and concrete.

PubMed

Topçu, Iker Bekir; Boga, Ahmet Raif

2010-07-01

Utilization of by-products or waste materials in concrete production are important subjects for sustainable development and industrial ecology concepts. The usages as mineral admixtures or fine aggregates improve the durability properties of concrete and thus increase the economic and environmental advantages for the concrete industry. The effect of clay waste (CW) containing boron on the mechanical properties of concrete was investigated. CW was added in different proportions as cement additive in concrete. The effect of CW on workability and strength of concrete were analysed by fresh and hardened concrete tests. The results obtained were compared with control concrete properties and Turkish standard values. The results showed that the addition of CW had a small effect upon the workability of the concrete but an important effect on the reduction of its strength. It was observed that strength values were quite near to that of control concrete when not more than 10% CW was used in place of cement. In addition to concrete specimens, replacing cement with CW produced mortar specimens, which were investigated for their strength and durability properties. The tests of SO( 4) (2-) and Cl(-) effect as well as freeze-thaw behaviour related to the durability of mortar were performed. Consequently, it can be said that some improvements were obtained in durability properties even if mechanical properties had decreased with increasing CW content.

Effects of patch quality and network structure on patch occupancy dynamics of a yellow-bellied marmot metapopulation.

PubMed

Ozgul, Arpat; Armitage, Kenneth B; Blumstein, Daniel T; Vanvuren, Dirk H; Oli, Madan K

2006-01-01

1. The presence/absence of a species at a particular site is the simplest form of data that can be collected during ecological field studies. We used 13 years (1990-2002) of survey data to parameterize a stochastic patch occupancy model for a metapopulation of the yellow-bellied marmot in Colorado, and investigated the significance of particular patches and the influence of site quality, network characteristics and regional stochasticity on the metapopulation persistence. 2. Persistence of the yellow-bellied marmot metapopulation was strongly dependent on the high quality colony sites, and persistence probability was highly sensitive to small changes in the quality of these sites. 3. A relatively small number of colony sites was ultimately responsible for the regional persistence. However, lower quality satellite sites also made a significant contribution to long-term metapopulation persistence, especially when regional stochasticity was high. 4. The northern network of the marmot metapopulation was more stable compared to the southern network, and the persistence of the southern network depended heavily on the northern network. 5. Although complex models of metapopulation dynamics may provide a more accurate description of metapopulation dynamics, such models are data-intensive. Our study, one of the very few applications of stochastic patch occupancy models to a mammalian species, suggests that stochastic patch occupancy models can provide important insights into metapopulation dynamics using data that are easy to collect.

Embedding of Cortical Representations by the Superficial Patch System

PubMed Central

Da Costa, Nuno M. A.; Girardin, Cyrille C.; Naaman, Shmuel; Omer, David B.; Ruesch, Elisha; Grinvald, Amiram; Douglas, Rodney J.

2011-01-01

Pyramidal cells in layers 2 and 3 of the neocortex of many species collectively form a clustered system of lateral axonal projections (the superficial patch system—Lund JS, Angelucci A, Bressloff PC. 2003. Anatomical substrates for functional columns in macaque monkey primary visual cortex. Cereb Cortex. 13:15–24. or daisy architecture—Douglas RJ, Martin KAC. 2004. Neuronal circuits of the neocortex. Annu Rev Neurosci. 27:419–451.), but the function performed by this general feature of the cortical architecture remains obscure. By comparing the spatial configuration of labeled patches with the configuration of responses to drifting grating stimuli, we found the spatial organizations both of the patch system and of the cortical response to be highly conserved between cat and monkey primary visual cortex. More importantly, the configuration of the superficial patch system is directly reflected in the arrangement of function across monkey primary visual cortex. Our results indicate a close relationship between the structure of the superficial patch system and cortical responses encoding a single value across the surface of visual cortex (self-consistent states). This relationship is consistent with the spontaneous emergence of orientation response–like activity patterns during ongoing cortical activity (Kenet T, Bibitchkov D, Tsodyks M, Grinvald A, Arieli A. 2003. Spontaneously emerging cortical representations of visual attributes. Nature. 425:954–956.). We conclude that the superficial patch system is the physical encoding of self-consistent cortical states, and that a set of concurrently labeled patches participate in a network of mutually consistent representations of cortical input. PMID:21383233

Suspended Patch Antenna Array With Electromagnetically Coupled Inverted Microstrip Feed

NASA Technical Reports Server (NTRS)

Simons, Rainee N.

2000-01-01

The paper demonstrates a four-element suspended patch antenna array, with a parasitic patch layer and an electromagnetically coupled inverted microstrip feed, for linear polarization at K-Band frequencies. This antenna has the following advantages over conventional microstrip antennas: First, the inverted microstrip has lower attenuation than conventional microstrip; hence, conductor loss associated with the antenna corporate feed is lower resulting in higher gain and efficiency. Second, conventional proximity coupled patch antennas require a substrate for the feed and a superstrate for the patch. However, the inverted microstrip fed patch antenna makes use of a single substrate, and hence, is lightweight and low cost. Third, electromagnetic coupling results in wider bandwidth. Details regarding the design and fabrication will be presented as well as measured results including return loss, radiation patterns and cross-polarization levels.

Adaptive Identification and Characterization of Polar Ionization Patches

NASA Technical Reports Server (NTRS)

Coley, W. R.; Heelis, R. A.

1995-01-01

Dynamics Explorer 2 (DE 2) spacecraft data are used to detect and characterize polar cap 'ionization patches' loosely defined as large-scale (greater than 100 km) regions where the F region plasma density is significantly enhanced (approx greater than 100%) above the background level. These patches are generally believed to develop in or equatorward of the dayside cusp region and then drift in an antisunward direction over the polar cap. We have developed a flexible algorithm for the identification and characterization of these structures, as a function of scale-size and density enhancement, using data from the retarding potential analyzer, the ion drift meter, and the langmuir probe on board the DE 2 satellite. This algorithm was used to study the structure and evolution of ionization patches as they cross the polar cap. The results indicate that in the altitude region from 240 to 950 km ion density enhancements greater than a factor of 3 above the background level are relatively rare. Further, the ionization patches show a preferred horizontal scale size of 300-400 km. There exists a clear seasonal and universal time dependence to the occurrence frequency of patches with a northern hemisphere maximum centered on the winter solstice and the 1200-2000 UT interval.

Using an index of habitat patch proximity for landscape design

Treesearch

Eric J. Gustafson; George R. Parker

1994-01-01

A proximity index (PX) inspired by island biogeography theory is described which quantifies the spatial context of a habitat patch in relation to its neighbors. The index distinguishes sparse distributions of small habitat patches from clusters of large patches. An evaluation of the relationship between PX and variation in the spatial characteristics of clusters of...

Robust Face Recognition via Multi-Scale Patch-Based Matrix Regression.

PubMed

Gao, Guangwei; Yang, Jian; Jing, Xiaoyuan; Huang, Pu; Hua, Juliang; Yue, Dong

2016-01-01

In many real-world applications such as smart card solutions, law enforcement, surveillance and access control, the limited training sample size is the most fundamental problem. By making use of the low-rank structural information of the reconstructed error image, the so-called nuclear norm-based matrix regression has been demonstrated to be effective for robust face recognition with continuous occlusions. However, the recognition performance of nuclear norm-based matrix regression degrades greatly in the face of the small sample size problem. An alternative solution to tackle this problem is performing matrix regression on each patch and then integrating the outputs from all patches. However, it is difficult to set an optimal patch size across different databases. To fully utilize the complementary information from different patch scales for the final decision, we propose a multi-scale patch-based matrix regression scheme based on which the ensemble of multi-scale outputs can be achieved optimally. Extensive experiments on benchmark face databases validate the effectiveness and robustness of our method, which outperforms several state-of-the-art patch-based face recognition algorithms.

Williams with Mission Patches in the A/L

NASA Image and Video Library

2016-08-14

Commander Jeff Williams poses for a photo in the Quest Airlock (A/L) with all of his mission patches. The patches are, from left, STS-101, Soyuz TMA-8, Expedition 13, Soyuz TMA-16, Expedition 21, Expedition 22, Soyuz TMA-20M, Expedition 47, and Expedition 48.

Surface patterning of nanoparticles with polymer patches

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

Choueiri, Rachelle M.; Galati, Elizabeth; Thérien-Aubin, Héloïse

Patterning of colloidal particles with chemically or topographically distinct surface domains (patches) has attracted intense research interest. Surface-patterned particles act as colloidal analogues of atoms and molecules serve as model systems in studies of phase transitions in liquid systems, behave as ‘colloidal surfactants’ and function as templates for the synthesis of hybrid particles. The generation of micrometre- and submicrometre-sized patchy colloids is now efficient but surface patterning of inorganic colloidal nanoparticles with dimensions of the order of tens of nanometres is uncommon. Such nanoparticles exhibit size- and shape-dependent optical, electronic and magnetic properties, and their assemblies show new collective properties.more » At present, nanoparticle patterning is limited to the generation of two-patch nanoparticles and nanoparticles with surface ripples or a ‘raspberry’ surface morphology. We demonstrate nanoparticle surface patterning, which utilizes thermodynamically driven segregation of polymer ligands from a uniform polymer brush into surface-pinned micelles following a change in solvent quality. Patch formation is reversible but can be permanently preserved using a photocrosslinking step. The methodology offers the ability to control the dimensions of patches, their spatial distribution and the number of patches per nanoparticle, in agreement with a theoretical model. The versatility of the strategy is demonstrated by patterning nanoparticles with different dimensions, shapes and compositions, tethered with various types of polymers and subjected to different external stimuli. Furthermore, these patchy nanocolloids have potential applications in fundamental research, the self-assembly of nanomaterials, diagnostics, sensing and colloidal stabilization.« less

Surface patterning of nanoparticles with polymer patches

DOE PAGES

Choueiri, Rachelle M.; Galati, Elizabeth; Thérien-Aubin, Héloïse; ...

2016-08-24

Patterning of colloidal particles with chemically or topographically distinct surface domains (patches) has attracted intense research interest. Surface-patterned particles act as colloidal analogues of atoms and molecules serve as model systems in studies of phase transitions in liquid systems, behave as ‘colloidal surfactants’ and function as templates for the synthesis of hybrid particles. The generation of micrometre- and submicrometre-sized patchy colloids is now efficient but surface patterning of inorganic colloidal nanoparticles with dimensions of the order of tens of nanometres is uncommon. Such nanoparticles exhibit size- and shape-dependent optical, electronic and magnetic properties, and their assemblies show new collective properties.more » At present, nanoparticle patterning is limited to the generation of two-patch nanoparticles and nanoparticles with surface ripples or a ‘raspberry’ surface morphology. We demonstrate nanoparticle surface patterning, which utilizes thermodynamically driven segregation of polymer ligands from a uniform polymer brush into surface-pinned micelles following a change in solvent quality. Patch formation is reversible but can be permanently preserved using a photocrosslinking step. The methodology offers the ability to control the dimensions of patches, their spatial distribution and the number of patches per nanoparticle, in agreement with a theoretical model. The versatility of the strategy is demonstrated by patterning nanoparticles with different dimensions, shapes and compositions, tethered with various types of polymers and subjected to different external stimuli. Furthermore, these patchy nanocolloids have potential applications in fundamental research, the self-assembly of nanomaterials, diagnostics, sensing and colloidal stabilization.« less

Volatility of fragrance chemicals: patch testing implications.

PubMed

Gilpin, Sarah J; Hui, Xiaoying; Maibach, Howard I

2009-01-01

Diagnostic and predictive patch testing to determine contact allergy due to fragrance materials requires applying a fixed dose of material to the skin. This dose can be affected by the volatile nature of fragrances; little data exist on how the loss of fragrance dose due to volatility affects patch testing. (1) To evaluate pH dependence and evaporation rates of two fragrance chemicals, geraniol, citronellol, and a common fragrance solvent, diethyl phthalate (DEP) and (2) Assess implications for predictive patch-testing methods for fragrances. pH analysis of each material at 1% for three values (4.0, 5.0, 7.0) was done over 40 hours. Volatility experiments for each material, nonradiolabeled and radiolabeled, were conducted over a 24-hour period, taking readings at six time points (5 minutes, 15 minutes, 40 minutes, 1 hour, 3 hours, and 24 hours). Evaporation rates were not sensitive to pH shifts from 4.0 to 7.0. Evaporation rates for nonradiolabeled materials were low: after 24 hours, geraniol lost 8.9%, citronellol 27.0% and DEP 14.5%. The volatility data for radiolabeled materials demonstrated that geraniol loses up to 39% of its dose, citronellol loses up to 26%, and DEP up to 14% within 40 minutes. The tendency of fragrance materials to evaporate can impact the dose being applied to the patch and therefore the result of the patch and ultimately the decision-making process regarding that fragrance material's safety. These data, developed with DEP, utilized in a predictive sensitization assay cannot be generalized.

When is it safe to stop patching?

PubMed

Oster, J G; Simon, J W; Jenkins, P

1990-12-01

Prior reports indicate that about half of amblyopia patients successfully treated with occlusion subsequently require maintenance patching. This retrospective study was designed to discover what clinical characteristics might be associated with a stable outcome following primary occlusion. Included were 188 patients who: (1) had amblyopia related to strabismus, anisometropia or media opacity; and (2) were followed up for at least one year after successful primary occlusion. Patients who did not comply with treatment or who did not achieve equal vision were excluded. Their ages ranged from 2 to 119 months (mean 29 months). Eighty-eight patients (47%) who required no further occlusion were designated the clinically stable group (CSG). The remaining 100 (53%), who subsequently needed patching because of unequal acuities, constituted the maintenance patching group (MPG). CSG patients were older at the beginning (mean 33 months) and at the end (mean 40 months) of primary occlusion than were MPG patients (means 26 and 31 months). Primary occlusion was more likely to have been discontinued because of equal recognition acuities in CSG patients, while equal fixation behaviour or preferential looking was more likely in MPG patients. Distribution of diagnoses, severity of amblyopia at presentation, and length of follow-up were similar in the two groups. Visual outcomes at last follow-up were slightly better in the CSG (p = 0.002). We conclude that, in general, patching can be safely discontinued after the third birthday. Although follow-up after primary occlusion is important to ensure stable results in all patients, preverbal children are more likely to require maintenance patching.

Multilayer Patch Antenna Surrounded by a Metallic Wall

NASA Technical Reports Server (NTRS)

Zawadzki, Mark; Huang, John

2003-01-01

A multilayer patch antenna, similar to a Yagi antenna, surrounded by a metallic wall has been devised to satisfy requirements to fit within a specified size and shape and to generate a beam with a half-power angular width of <=40 deg. This antenna provides a gain of about 14 dB; in contrast, the gain of a typical single-patch antenna lies between 5 and 6 dB. This antenna can be considered an alternative to a two-dimensional array of patch antenna elements, or to a horn or helical antenna. Unlike a two-dimensional array of patches, this antenna can function without need for a power-division network (unless circular polarization is needed). The profile of this antenna is lower than that of a horn or a helical antenna designed for the same frequency. The primary disadvantage of this antenna, relative to a horn or a helical antenna, is that its footprint is slightly larger.

Covalent modification of pericardial patches for sustained rapamycin delivery inhibits venous neointimal hyperplasia

PubMed Central

Bai, Hualong; Lee, Jung Seok; Chen, Elizabeth; Wang, Mo; Xing, Ying; Fahmy, Tarek M.; Dardik, Alan

2017-01-01

Prosthetic grafts and patches are commonly used in cardiovascular surgery, however neointimal hyperplasia remains a significant concern, especially under low flow conditions. We hypothesized that delivery of rapamycin from nanoparticles (NP) covalently attached to patches allows sustained site-specific delivery of therapeutic agents targeted to inhibit localized neointimal hyperplasia. NP were covalently linked to pericardial patches using EDC/NHS chemistry and could deliver at least 360 ng rapamycin per patch without detectable rapamycin in serum; nanoparticles were detectable in the liver, kidney and spleen but no other sites within 24 hours. In a rat venous patch angioplasty model, control patches developed robust neointimal hyperplasia on the patch luminal surface characterized by Eph-B4-positive endothelium and underlying SMC and infiltrating cells such as macrophages and leukocytes. Patches delivering rapamycin developed less neointimal hyperplasia, less smooth muscle cell proliferation, and had fewer infiltrating cells but retained endothelialization. NP covalently linked to pericardial patches are a novel composite delivery system that allows sustained site-specific delivery of therapeutics; NP delivering rapamycin inhibit patch neointimal hyperplasia. NP linked to patches may represent a next generation of tissue engineered cardiovascular implants. PMID:28071663

Covalent modification of pericardial patches for sustained rapamycin delivery inhibits venous neointimal hyperplasia

NASA Astrophysics Data System (ADS)

Bai, Hualong; Lee, Jung Seok; Chen, Elizabeth; Wang, Mo; Xing, Ying; Fahmy, Tarek M.; Dardik, Alan

2017-01-01

Prosthetic grafts and patches are commonly used in cardiovascular surgery, however neointimal hyperplasia remains a significant concern, especially under low flow conditions. We hypothesized that delivery of rapamycin from nanoparticles (NP) covalently attached to patches allows sustained site-specific delivery of therapeutic agents targeted to inhibit localized neointimal hyperplasia. NP were covalently linked to pericardial patches using EDC/NHS chemistry and could deliver at least 360 ng rapamycin per patch without detectable rapamycin in serum; nanoparticles were detectable in the liver, kidney and spleen but no other sites within 24 hours. In a rat venous patch angioplasty model, control patches developed robust neointimal hyperplasia on the patch luminal surface characterized by Eph-B4-positive endothelium and underlying SMC and infiltrating cells such as macrophages and leukocytes. Patches delivering rapamycin developed less neointimal hyperplasia, less smooth muscle cell proliferation, and had fewer infiltrating cells but retained endothelialization. NP covalently linked to pericardial patches are a novel composite delivery system that allows sustained site-specific delivery of therapeutics; NP delivering rapamycin inhibit patch neointimal hyperplasia. NP linked to patches may represent a next generation of tissue engineered cardiovascular implants.

A clinical study of transdermal contraceptive patch in Thai adolescence women.

PubMed

Piyasirisilp, Rachatapon; Taneepanichskul, Surasak

2008-02-01

To study cycle control, compliance and safety of a transdermal contraceptive patch in adolescent Thai women. Fifty-eight healthy women were assigned to receive 3 cycles of contraceptive patch (ethinyl estradiol 20 microg and norelgestromin 150 microg/day). All participants aged 16-20 years were invited to participate from the family planning clinic at King Chulalongkorn Memorial Hospital. Data were collected on adverse effects, perceived advantages and disadvantages, body weight, blood pressure, patch detachments and compliance. Data were analyzed using mean, percentage and student's t-test. The participants' average age was 19.4 years, height 158.8 cm, weight 51.8 kg, BMI 20.8 Kg/m2. The most location of patch application was the abdomen and the most adverse event was breast tenderness (31.0%) followed by application site reaction, nausea vomiting and headache respectively. The breast symptom was mild in severity. The participants reported decrease in dysmenorrhea and shorter duration of bleeding. There were no significant changes in body weight and blood pressure. The improvement of their facial acne was reported. There were no pregnancies during use and the adhesion of the contraceptive patch is excellent. Partial patch detachment was reported in only 6.9%. No completed patch detachment was found. The present study found an overall positive impression of a new transdermal contraceptive patch. The good compliance and few side effects were demonstrated. The adhesive patch contraceptive was excellent.

Isolation and functional characteristics of adherent phagocytic cells from mouse Peyer's patches.

PubMed Central

MacDonald, T T; Carter, P B

1982-01-01

Attempts were made to isolate adherent phagocytic cells (macrophages) from mouse Peyer's patch cell suspensions. Cell suspensions prepared by teasing apart the Peyer's patches contained no adherent phagocytic cells. However, if Peyer's patch fragments were treated with collagenase to disrupt the tissue matrix, cells prepared in this way contained a subpopulation of adherent phagocytic cells. These cells comprised only 0.1-0.2% of the total nucleated cell population of the Peyer's patch. Similar cells could also be isolated from the Peyer's patches of germ-free mice, but as judged by their ability to ingest opsonized erythrocytes, these cells were less activated than cells from the Peyer's patches of normal mice. Adherent cells from the Peyer's patches of normal mice could present antigen (ovalbumin) to T cells, and Peyer's patches cell suspensions containing adherent cells could be stimulated in vitro to produce an anti-sheep red blood cell plaque-forming cell response in the absence of 2-mercaptoethanol. These studies show that although the frequency of phagocytic adherent cells is extremely low in Peyer's patches, these cells have functions consistent with that of adherent cells in other lymphoid tissues. PMID:7068173

Effects of Sediment Patches on Sediment Transport Predictions in Steep Mountain Channels

NASA Astrophysics Data System (ADS)

Monsalve Sepulveda, A.; Yager, E.

2013-12-01

Bed surface patches occur in most gravel-bedded rivers and in steep streams can be divided between relatively immobile boulders and more mobile patches of cobbles and gravel. This spatial variability in grain size, roughness and sorting impact bed load transport by altering the relative local mobility of different grain sizes and creating complex local flow fields. Large boulders also bear a significant part of the total shear stress and we hypothesize that the remaining shear stress on a given mobile patch is a distribution of values that depend on the local topography, patch type and location relative to the large roughness elements and thalweg. Current sediment transport equations do not account for the variation in roughness, local flow and grain size distributions on and between patches and often use an area-weighted approach to obtain a representative grain size distribution and reach-averaged shear stress. Such equations also do not distinguish between active (patches where at least one grain size is in motion) and inactive patches or include the difference in mobility between patch classes as result of spatial shear stress distributions. To understand the effects of sediment patches on sediment transport in steep channels, we calculated the shear stress distributions over a range of patch classes in a 10% gradient step-pool stream. We surveyed the bed with a high density resolution (every 5 cm in horizontal and vertical directions over a 40 m long reach) using a total station and terrestrial LiDAR, mapped and classified patches by their grain size distributions, and measured water surface elevations and mean velocities for low to moderate flow events. Using these data we calibrated a quasi-three dimensional model (FaSTMECH) to obtain shear stress distributions over each patch for a range of flow discharges. We modified Parker's (1990) equations to use the calculated shear stress distribution, measured grain sizes, and a specific hiding function for each

Front-Side Microstrip Line Feeding a Raised Antenna Patch

NASA Technical Reports Server (NTRS)

Hodges, Richard; Hoppe, Daniel

2005-01-01

An improved design concept for a printed-circuit patch antenna and the transmission line that feeds the patch calls for (1) a microstrip transmission line on the front (radiative) side of a printed-circuit board based on a thin, high-permittivity dielectric substrate; (2) using the conductor covering the back side of the circuit board as a common ground plane for both the microstrip line and the antenna patch; (3) supporting the antenna patch in front of the circuit board on a much thicker, lower-permittivity dielectric spacer layer; and (4) connecting the microstrip transmission line to the patch by use of a thin wire or narrow ribbon that extends through the thickness of the spacer and is oriented perpendicularly to the circuit-board plane. The thickness of the substrate is typically chosen so that a microstrip transmission line of practical width has an impedance between 50 and 100 ohms. The advantages of this design concept are best understood in the context of the disadvantages of prior design concepts, as explained

Reconfigurable Wideband Circularly Polarized Stacked Square Patch Antenna for Cognitive Radios

NASA Technical Reports Server (NTRS)

Barbosa Kortright, Miguel A.; Waldstein, Seth W.; Simons, Rainee N.

2017-01-01

An almost square patch and a square patch with corner truncation for circularly polarized (CP) and a stacked CP square patch are researched and developed at X-band for cognitive devices. A draft set of presentation charts are attached.

Dissolving polymer microneedle patches for influenza vaccination.

PubMed

Sullivan, Sean P; Koutsonanos, Dimitrios G; Del Pilar Martin, Maria; Lee, Jeong Woo; Zarnitsyn, Vladimir; Choi, Seong-O; Murthy, Niren; Compans, Richard W; Skountzou, Ioanna; Prausnitz, Mark R

2010-08-01

Influenza prophylaxis would benefit from a vaccination method enabling simplified logistics and improved immunogenicity without the dangers posed by hypodermic needles. Here we introduce dissolving microneedle patches for influenza vaccination using a simple patch-based system that targets delivery to skin's antigen-presenting cells. Microneedles were fabricated using a biocompatible polymer encapsulating inactivated influenza virus vaccine for insertion and dissolution in the skin within minutes. Microneedle vaccination generated robust antibody and cellular immune responses in mice that provided complete protection against lethal challenge. Compared to conventional intramuscular injection, microneedle vaccination resulted in more efficient lung virus clearance and enhanced cellular recall responses after challenge. These results suggest that dissolving microneedle patches can provide a new technology for simpler and safer vaccination with improved immunogenicity that could facilitate increased vaccination coverage.

Patch tests with fragrance materials and preservatives.

PubMed

de Groot, A C; Liem, D H; Nater, J P; van Ketel, W G

1985-02-01

179 patients suspected of cosmetic allergy were patch tested with a series of 16 fragrance materials and 9 preservatives. In 67 patients (37.4%), 1 or more of these substances gave positive reactions. In the group of fragrance materials, the largest numbers of positive patch test reactions were seen to isoeugenol, oak moss, geraniol, alpha-amylcinnamic alcohol, and a mixture of alpha-amylcinnamic aldehyde and alpha-hexylcinnamic aldehyde. The fragrance mix in the ICDRG standard series detected nearly 80% of cases of contact allergy to fragrance materials other than its constituents. In the group of preservatives, Kathon CG and quaternium-15 scored the highest number of positive reactions. It is argued that the commonly used patch test concentrations of 2% for oak moss and geraniol may be too low to detect all cases of sensitization.