Supporting Student Presentations and Participation at Professional Conferences

ERIC Educational Resources Information Center

McGuire, Margaret A.; Simpson, Cynthia; Duke, Lindsay Nicole

2009-01-01

Mentoring early childhood education students who are preparing to attend and make presentations at a conference can be rewarding for all involved. Often, students present current research they have conducted or share specific expertise in areas such as lesson planning, learning materials, or fund-raising. Successful mentoring, leading to…

Quantitative Literacy for Undergraduate Business Students in the 21st Century

ERIC Educational Resources Information Center

McClure, Richard; Sircar, Sumit

2008-01-01

The current business environment is awash in vast amounts of data that ongoing transactions continually generate. Leading-edge corporations are using business analytics to achieve competitive advantage. However, educators are not adequately preparing business school students in quantitative methods to meet this challenge. For more than half a…

Learning While Leading: A Multiple Case Study of Principals' Ways of Knowing

ERIC Educational Resources Information Center

Cale, Marsha Caudill

2017-01-01

Excellent school leadership is undeniably linked to improved student achievement. Due to the impact administrators have on school and student success, it is critical that current and aspiring principals receive high-quality training and support. Superior principal preparation programs and ongoing training opportunities are fundamental to…

When does the future begin? Time metrics matter, connecting present and future selves.

PubMed

Lewis, Neil A; Oyserman, Daphna

2015-06-01

People assume they should attend to the present; their future self can handle the future. This seemingly plausible rule of thumb can lead people astray, in part because some future events require current action. In order for the future to energize and motivate current action, it must feel imminent. To create this sense of imminence, we manipulated time metric--the units (e.g., days, years) in which time is considered. People interpret accessible time metrics in two ways: If preparation for the future is under way (Studies 1 and 2), people interpret metrics as implying when a future event will occur. If preparation is not under way (Studies 3-5), they interpret metrics as implying when preparation should start (e.g., planning to start saving 4 times sooner for a retirement in 10,950 days instead of 30 years). Time metrics mattered not because they changed how distal or important future events felt (Study 6), but because they changed how connected and congruent their current and future selves felt (Study 7). © The Author(s) 2015.

Fabrication and characterization of lead-free BaTiO3 thin film for storage device applications

NASA Astrophysics Data System (ADS)

Sharma, Hakikat; Negi, N. S.

2018-05-01

The lead-free BaTiO3 (BT) thin film solution has been prepared by sol-gel method. The prepared solution spin coated on Pt/TiO2/SiO2/ Si substrate. The fabricated thin film was analyzed by XRD and Raman spectrometer for structural conformation. Uniformity of thin film was examined by Atomic force microscope (AFM). Thickness of the film was measured by cross sectional FESEM. Activation energies for both positive and negative biasing have been calculated from temperature dependent leakage current density as a function of electric field. For ferroelectric memory devices such as FRAM the hysteresis loop plays important role. Electric filed dependent polarization of BT thin film measured at different switching voltages. With increasing voltage maximum polarization increases.

An Introduction to the Standards for Preparation and Professional Development for Teachers of Engineering

ERIC Educational Resources Information Center

Reimers, Jackson E.; Farmer, Cheryl L.; Klein-Gardner, Stacy S.

2015-01-01

The past 30 years have yielded a mature body of research regarding effective professional development for teachers of science and mathematics, leading to a robust selection of professional development programs for these teachers. The current emphasis on connections among science, technology, engineering, and mathematics underscores the need for…

Meaningful Use of Simulation as an Educational Method in Nursing Programs

ERIC Educational Resources Information Center

Thompson, Teri L.

2011-01-01

The purpose of this descriptive study was to examine the use of simulation technology within nursing programs leading to licensure as registered nurses. In preparation for this study the Use of Simulation Technology Inventory (USTI) was developed and based in the structure, processes, outcomes model and the current literature on simulation. The…

Utilizing Theatre of the Oppressed within Teacher Education to Create Emancipatory Teachers

ERIC Educational Resources Information Center

Desai, Shiv R.

2017-01-01

A key focus of teacher preparation should be critical self-reflection, especially given the current context of market-driven school reform, which often leads to school closings, increases school segregation, and devastates local communities. The question, then, becomes how best to guide critical self-reflection for preservice teachers so that they…

Survey of the Royal Australasian College of Physicians examination candidates: preparation and impact on lifestyle.

PubMed

Perrin, K; Prasad, S; Robinson, G

2005-11-01

Candidates currently view the Royal Australasian College of Physicians' written examination as a major undertaking, knowing that approximately one-third fail on their first attempt. We anonymously surveyed New Zealand registrars who sat the written examination in 2004. We found that the majority of candidates spend long hours preparing over a several months, and that the examination had a detrimental impact on their personal lives. The results of this survey have important implications in the context of efforts to reduce the stress of doctors, and should lead to a change in either the examination itself or an increase in support provided to registrars preparing for it.

Lead-acid batteries with polymer-structured electrodes for electric-vehicle applications

NASA Astrophysics Data System (ADS)

Soria, M. L.; Fullea, J.; Sáez, F.; Trinidad, F.

Some years ago a consortium of enterprises and a university from different European countries and industrial sectors was established to work together in the development of lighter lead-acid batteries for electrical and conventional vehicles with new innovative materials and process techniques, with the final goal of increasing the energy density by means of a battery weight reduction. Its main idea was to substitute the heavy lead alloy grids (mechanical support of the active masses and collectors of the current produced during the charge and discharge reactions) by lightweight metallised polymeric network structures (PNS) with reduced mesh dimensions in comparison to conventional grids. The network was then coated with conductive materials and corrosion resistant layers to conduct the current flow. In this paper, the electrode characteristics and the design features of the batteries prepared in the project will be described and their electrical performance presented.

Auditing Inequity: Teaching Aspiring Administrators to Be Social Justice Leaders

ERIC Educational Resources Information Center

Hernandez, Frank; Marshall, Joanne

2017-01-01

While much has been written about preparing educational leaders to lead for social justice, much less has been written about how to do so. This study is one of the first to analyze the reflections and written assignments of aspiring administrators to determine what they are currently thinking about poverty, race/ethnicity, and social justice…

Teenage Suicide. Hearing before the Subcommittee on Juvenile Justice of the Committee on the Judiciary. United States Senate, Ninety-Eighth Congress, Second Session on Oversight on the Factors That May Lead to Teenage Suicide, and What May Be Done to Prevent That Tragedy (October 3, 1984).

ERIC Educational Resources Information Center

Congress of the U.S., Washington, DC. Senate Committee on the Judiciary.

This document contains transcripts of witness testimony and prepared statements from the Congressional hearing called to examine the issue of teenage suicide. Testimony is focused on the factors that may lead to teenage suicide, what might be done to prevent these deaths, what the federal government is currently doing in this area, and what action…

New route for hollow materials

NASA Astrophysics Data System (ADS)

Rivaldo-Gómez, C. M.; Ferreira, F. F.; Landi, G. T.; Souza, J. A.

2016-08-01

Hollow micro/nano structures form an important family of functional materials. We have used the thermal oxidation process combined with the passage of electric current during a structural phase transition to disclose a colossal mass diffusion transfer of Ti ions. This combination points to a new route for fabrication of hollow materials. A structural phase transition at high temperature prepares the stage by giving mobility to Ti ions and releasing vacancies to the system. The electric current then drives an inward delocalization of vacancies, condensing into voids, and finally turning into a big hollow. This strong physical phenomenon leading to a colossal mass transfer through ionic diffusion is suggested to be driven by a combination of phase transition and electrical current followed by chemical reaction. We show this phenomenon for Ti leading to TiO2 microtube formation, but we believe that it can be used to other metals undergoing structural phase transition at high temperatures.

Non-preserved 1% lidocaine solution has less antibacterial properties than currently available anaesthetic eye-drops.

PubMed

Labetoulle, Marc; Frau, Eric; Offret, Hervé; Nordmann, Patrice; Naas, Thierry

2002-08-01

Some anaesthetics inhibit bacterial growth, and thus may lead to low rates of positive cultures from bacterial keratitis. Antibacterial properties of lidocaine were compared with those of oxybuprocaine or tetracaine, either in current commercial eye lotions or in extemporaneous solutions. Forty-eight bacterial strains were used to determine the minimum inhibitory and bactericidal concentrations of four commercial eye lotions containing oxybuprocaine or tetracaine, of a non-ophthalmic 1% lidocaine commercial solution and of extemporaneously prepared solutions of oxybuprocaine, tetracaine, lidocaine and benzalkonium. Most strains had their growth inhibited by 0.2% oxybuprocaine or 0.4% tetracaine, which corresponds to a 1/2 dilution of the commercial eye-drops. Bacterial growth was still observed with a 1% lidocaine solution. Currently available anaesthetic eye-drops that are used before corneal specimen collection may lead to false-negative bacterial cultures. Conversely, a non-preserved 1% lidocaine solution might be more appropriate in corneal specimen collection.

Lead free CH{sub 3}NH{sub 3}SnI{sub 3} perovskite thin-film with p-type semiconducting nature and metal-like conductivity

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

Iefanova, Anastasiia; Adhikari, Nirmal; Dubey, Ashish

Lead free CH{sub 3}NH{sub 3}SnI{sub 3} perovskite thin film was prepared by low temperature solution processing and characterized using current sensing atomic force microscopy (CS-AFM). Analysis of electrical, optical, and optoelectrical properties reveals unique p-type semiconducting nature and metal like conductivity of this material. CH{sub 3}NH{sub 3}SnI{sub 3} film also showed a strong absorption in visible and near infrared spectrum with absorption onset of 1.3 eV. X-ray Diffraction analysis and scanning electron microscopy (SEM) confirmed a structure of this compound and uniform film formation. The morphology, film uniformity, light harvesting and electrical properties strongly depend on preparation method and precursormore » solution. CH{sub 3}NH{sub 3}SnI{sub 3} films prepared based on dimethylformamide (DMF) showed higher crystallinity and light harvesting capability compared to the film based on combination of dimethyl sulfoxide (DMSO) with gamma-butyrolactone (GBL). Local photocurrent mapping analysis showed that CH{sub 3}NH{sub 3}SnI{sub 3} can be used as an active layer and have a potential to fabricate lead free photovoltaic devices.« less

Improvements and Performance of the Fermilab Solenoid Test Facility

DOE PAGES

Orris, Darryl; Arnold, Don; Brandt, Jeffrey; ...

2017-06-01

Here, the Solenoid Test Facility at Fermilab was built using a large vacuum vessel for testing of conduction-cooled superconducting solenoid magnets, and was first used to determine the performance of the MICE Coupling Coil. The facility was modified recently to enable testing of solenoid magnets for the Mu2e experiment, which operate at much higher current than the Coupling Coil. One pair of low current conduction-cooled copper and NbTi leads was replaced with two pairs of 10 kA HTS leads cooled by heat exchange with liquid nitrogen and liquid helium. The new design, with additional control and monitoring capability, also providesmore » helium cooling of the superconducting magnet leads by conduction. A high current power supply with energy extraction was added, and several improvements to the quench protection and characterization system were made. Here we present details of these changes and report on performance results from a test of the Mu2e prototype Transport Solenoid (TS) module. Progress on additional improvements in preparation for production TS module testing will be presented.« less

Improvements and Performance of the Fermilab Solenoid Test Facility

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

Orris, Darryl; Arnold, Don; Brandt, Jeffrey

Here, the Solenoid Test Facility at Fermilab was built using a large vacuum vessel for testing of conduction-cooled superconducting solenoid magnets, and was first used to determine the performance of the MICE Coupling Coil. The facility was modified recently to enable testing of solenoid magnets for the Mu2e experiment, which operate at much higher current than the Coupling Coil. One pair of low current conduction-cooled copper and NbTi leads was replaced with two pairs of 10 kA HTS leads cooled by heat exchange with liquid nitrogen and liquid helium. The new design, with additional control and monitoring capability, also providesmore » helium cooling of the superconducting magnet leads by conduction. A high current power supply with energy extraction was added, and several improvements to the quench protection and characterization system were made. Here we present details of these changes and report on performance results from a test of the Mu2e prototype Transport Solenoid (TS) module. Progress on additional improvements in preparation for production TS module testing will be presented.« less

The Current State of Scientific Knowledge on Pre-Kindergarten Effects

ERIC Educational Resources Information Center

Center for Child and Family Policy, Duke University, 2017

2017-01-01

The question of how the U.S. will develop a citizenry with the skills necessary to meet the challenges of the 21st century has attracted the attention of legislators, scientists, and educators. Answering this question leads inevitably to its roots: how well are we preparing young children to enter kindergarten ready to learn? Educators in k-12…

Fellowship training at John Hopkins: programs leading to careers in librarianship and informatics as informaticians or informationists.

PubMed

Campbell, Jayne M; Roderer, Nancy K

2005-01-01

Preparing librarians to meet the information challenges faced in the current and future health care environments is critical. At Johns Hopkins University, three NLM-funded fellowship programs provide opportunities for librarians to utilize the rich environments of the Welch Medical Library and the Division of Health Sciences Informatics in support of life-long learning.

Proceedings of the biomagnetic effects workshop. [Lead abstract

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

Tenforde, T.S.

1978-01-01

Separate abstracts were prepared for six of the eight chapters contained in these proceedings. The other two chapters contain introductory material (Chapter 1) dealing with the rationale for the work shop, and a summary (Chapter 8) of the major objectives that were accomplished at the workshop relative to the current status of awareness in the field of biomagnetic effects. (ERB)

Standard Operating Procedure for the Preparation of Lead-Containing Paint Films and Lead-in-Paint Diagnostic Test Materials

EPA Science Inventory

This SOP describes the preparation of stand-alone, lead paint films, prepared according to the old paint recipes. Further, this SOP describes the use of these paint films for the preparation of simulated old paints on a variety of substrates. Substrates used included wood, stee...

Laser-based surface preparation of composite laminates leads to improved electrodes for electrical measurements

NASA Astrophysics Data System (ADS)

Almuhammadi, Khaled; Selvakumaran, Lakshmi; Alfano, Marco; Yang, Yang; Bera, Tushar Kanti; Lubineau, Gilles

2015-12-01

Electrical impedance tomography (EIT) is a low-cost, fast and effective structural health monitoring technique that can be used on carbon fiber reinforced polymers (CFRP). Electrodes are a key component of any EIT system and as such they should feature low resistivity as well as high robustness and reproducibility. Surface preparation is required prior to bonding of electrodes. Currently this task is mostly carried out by traditional sanding. However this is a time consuming procedure which can also induce damage to surface fibers and lead to spurious electrode properties. Here we propose an alternative processing technique based on the use of pulsed laser irradiation. The processing parameters that result in selective removal of the electrically insulating resin with minimum surface fiber damage are identified. A quantitative analysis of the electrical contact resistance is presented and the results are compared with those obtained using sanding.

Protective effects of vaccines against Bordetella parapertussis in a mouse intranasal challenge model.

PubMed

Komatsu, Eiji; Yamaguchi, Fuminori; Eguchi, Masahiro; Watanabe, Mineo

2010-06-17

Bordetella parapertussis causes typical whooping cough, as does Bordetella pertussis. However, current commercial vaccines are ineffective against B. parapertussis. In an effort to develop vaccines that are effective in protecting against both B. pertussis and B. parapertussis, we examined the protective effects of vaccines prepared from whole-cells and from recombinant proteins derived from B. parapertussis in a mouse intranasal challenge model. We confirmed current pertussis vaccines did not induce protective immunity against B. parapertussis in the mouse model. A whole-cell vaccine prepared from B. parapertussis induced protective immunity against B. parapertussis but not against B. pertussis, suggesting a combination of a current pertussis vaccine with a whole-cell parapertussis vaccine might prevent whooping cough caused by both species of Bordetella. We also found that filamentous hemagglutinin was a protective antigen of B. parapertussis. Our observations should lead to the development of new pertussis vaccines that can control the two prevalent forms of whooping cough.

Scientific Insights in the Preparation and Characterisation of a Lead-based Naga Bhasma.

PubMed

Nagarajan, S; Krishnaswamy, S; Pemiah, Brindha; Rajan, K S; Krishnan, Umamaheswari; Sethuraman, S

2014-01-01

Naga bhasma is one of the herbo-metallic preparations used in Ayurveda, a traditional Indian System of Medicine. The preparation of Naga bhasma involves thermal treatment of 'Naga' (metallic lead) in a series of quenching liquids, followed by reaction with realgar and herbal constituents, before calcination to prepare a fine product. We have analysed the intermediates obtained during different stages of preparation to understand the relevance and importance of different steps involved in the preparation. Our results show that 'Sodhana' (purification process) removes heavy metals other than lead, apart from making it soft and amenable for trituration. The use of powders of tamarind bark and peepal bark maintains the oxidation state of lead in Jarita Naga (lead oxide) as Pb(2+). The repeated calcination steps result in the formation of nano-crystalline lead sulphide, the main chemical species present in Naga bhasma.

Scientific Insights in the Preparation and Characterisation of a Lead-based Naga Bhasma

PubMed Central

Nagarajan, S.; Krishnaswamy, S.; Pemiah, Brindha; Rajan, K. S.; Krishnan, Umamaheswari; Sethuraman, S.

2014-01-01

Naga bhasma is one of the herbo-metallic preparations used in Ayurveda, a traditional Indian System of Medicine. The preparation of Naga bhasma involves thermal treatment of ‘Naga’ (metallic lead) in a series of quenching liquids, followed by reaction with realgar and herbal constituents, before calcination to prepare a fine product. We have analysed the intermediates obtained during different stages of preparation to understand the relevance and importance of different steps involved in the preparation. Our results show that ‘Sodhana’ (purification process) removes heavy metals other than lead, apart from making it soft and amenable for trituration. The use of powders of tamarind bark and peepal bark maintains the oxidation state of lead in Jarita Naga (lead oxide) as Pb2+. The repeated calcination steps result in the formation of nano-crystalline lead sulphide, the main chemical species present in Naga bhasma. PMID:24799737

Establishment of the first international standard for PEGylated granulocyte colony stimulating factor (PEG-G-CSF): Report of an international collaborative study

PubMed Central

Wadhwa, Meenu; Bird, Chris; Dougall, Thomas; Rigsby, Peter; Bristow, Adrian; Thorpe, Robin

2015-01-01

We assessed the feasibility of developing a suitable international reference standard for determination of in vitro biological activity of human sequence recombinant PEG-G-CSF products with a 20 kD linear PEG linked to the N-terminal methionyl residue of G-CSF (INN Filgrastim), produced using a conjugation process and coupling chemistry similar to that employed for the lead PEGfilgrastim product. Based on initial data which showed that the current WHO 2nd international standard, IS for G-CSF (09/136) or alternatively, a PEG-G-CSF standard with a unitage traceable to the G-CSF IS may potentially serve as the IS for PEG-G-CSF products, two candidate preparations of PEG-G-CSF were formulated and lyophilized at NIBSC. These preparations were tested by 23 laboratories using in vitro bioassays in a multi-centre collaborative study. Results indicated that on the basis of parallelism, the current WHO 2nd IS for G-CSF or any of the PEG-G-CSF samples could be used as the international standard for PEG-G-CSF preparations. However, because of the variability in potency estimates seen when PEG-G-CSF preparations were compared with the current WHO 2nd IS for G-CSF, a candidate PEG-G-CSF was suitable as the WHO IS. The preparation 12/188 was judged suitable to serve as the WHO IS based on in vitro biological activity data. Therefore, the preparation coded 12/188 was established by the WHO Expert Committee on Biological Standardization (ECBS) in 2013 as the WHO 1st IS for human PEGylated G-CSF with an assigned in vitro bioactivity of 10,000 IU per ampoule. PMID:25450254

Non-equilibrium transport in the quantum dot: quench dynamics and non-equilibrium steady state

NASA Astrophysics Data System (ADS)

Culver, Adrian; Andrei, Natan

We calculate the non-equilibrium current driven by a voltage drop across a quantum dot. The system is described by the two lead Anderson model at zero temperature with on-site Coulomb repulsion and non-interacting, linearized leads. We prepare the system in an initial state consisting of a free Fermi sea in each lead with the voltage drop given as the difference between the two Fermi levels. We quench the system by coupling the dot to the leads at t =0 and following the time evolution of the wavefunction. In the long time limit a new type of Bethe Ansatz wavefunction emerges, which satisfies the Lippmann-Schwinger equation with the two Fermi seas serving as the boundary conditions. The solution describes the non-equilibrium steady state of the system. We use this solution to compute the infinite time limit of the expectation value of the current operator at a given voltage, yielding the I-V characteristic. The calculation is non-perturbative and exact. Research supported by NSF Grant DMR 1410583.

Non-equilibrium transport in the quantum dot: quench dynamics and non-equilibrium steady state

NASA Astrophysics Data System (ADS)

Culver, Adrian; Andrei, Natan

We present an exact method of calculating the non-equilibrium current driven by a voltage drop across a quantum dot. The system is described by the two lead Anderson model at zero temperature with on-site Coulomb repulsion and non-interacting, linearized leads. We prepare the system in an initial state consisting of a free Fermi sea in each lead with the voltage drop given as the difference between the two Fermi levels. We quench the system by coupling the dot to the leads at t = 0 and following the time evolution of the wavefunction. In the long time limit a new type of Bethe Ansatz wavefunction emerges, which satisfies the Lippmann-Schwinger equation with the two Fermi seas serving as the boundary conditions. This exact, non-perturbative solution describes the non-equilibrium steady state of the system. We describe how to use this solution to compute the infinite time limit of the expectation value of the current operator at a given voltage, which would yield the I-V characteristic of the dot. Research supported by NSF Grant DMR 1410583.

Decreasing Your Student Loan Cohort Default Rate: Leading a College-Wide Change Initiative at Mohave Community College

ERIC Educational Resources Information Center

Charles, Kayla D.; Sheaff, Shannon; Woods, Jann; Downey, Lisa

2016-01-01

Burgeoning student debt and the ability of programs to adequately prepare students for jobs that will allow them to repay that debt comprise a topic of great interest in the current higher education policy environment. A key accountability measure used by the Department of Education for more than two decades has been the student loan cohort…

A METHOD OF PREPARING URANIUM DIOXIDE

DOEpatents

Scott, F.A.; Mudge, L.K.

1963-12-17

A process of purifying raw, in particular plutonium- and fission- products-containing, uranium dioxide is described. The uranium dioxide is dissolved in a molten chloride mixture containing potassium chloride plus sodium, lithium, magnesium, or lead chloride under anhydrous conditions; an electric current and a chlorinating gas are passed through the mixture whereby pure uranium dioxide is deposited on and at the same time partially redissolved from the cathode. (AEC)

Small High Schools on a Larger Scale: The First Three Years of the Chicago High School Redesign Initiative. Research Report

ERIC Educational Resources Information Center

Kahne, Joseph E.; Sporte, Susan E.; de la Torre, Marisa

2006-01-01

Increasingly, researchers, policymakers, school leaders, and concerned citizens are recognizing that high schools in the United States are in need of major reform. Current research shows that high schools are not preparing students for college, work, or life, and that they are leading to increased alienation among students. In a much-noted speech…

Pre-registration children's and young people's nurse preparation. A SWOT analysis.

PubMed

Richardson, Jim; McEwing, Gillian; Glasper, Edward Alan

2006-12-01

An investigation was undertaken into the views of nurse educators on current approaches to preparing children's and young people's nurses in the UK. A convenience sample of lead academics in 17 child health nursing departments of British universities was contacted by email and invited to liaise with colleagues to generate lists of the strengths, weaknesses, opportunities and threats (SWOT) of the educational system. Thirteen departments provided data that were analysed and themed. Major themes included the common foundation programme, clinical skills learning, clinical placements and employment. More detailed evaluative work should be undertaken before wholesale changes are made to a relatively new curriculum.

Acid anhydrides: a simple route to highly pure organometallic solutions for superconducting films

NASA Astrophysics Data System (ADS)

Roma, N.; Morlens, S.; Ricart, S.; Zalamova, K.; Moreto, J. M.; Pomar, A.; Puig, T.; Obradors, X.

2006-06-01

The presence of impurities in the precursor metal carboxylate solutions for the preparation of epitaxial thin films by metal organic decomposition (MOD) is substantially avoided by the use of acid anhydrides. In particular, trifluoroacetic anhydride (TFAA) was used for the synthesis of the starting Y, Ba and Cu trifluoroacetates used in YBa2Cu3O7-x (YBCO) preparation by the MOD process. In this way, highly stable organometallic precursors and a short pyrolysis process could be used leading to YBCO films with high critical currents (Jc >=2-4 MA cm-2 at 77 K). Furthermore, the reproducibility of the results has been ascertained.

Preparation of porous lead from shape-controlled PbO bulk by in situ electrochemical reduction in ChCl-EG deep eutectic solvent

NASA Astrophysics Data System (ADS)

Ru, Juanjian; Hua, Yixin; Xu, Cunying; Li, Jian; Li, Yan; Wang, Ding; Zhou, Zhongren; Gong, Kai

2015-12-01

Porous lead with different shapes was firstly prepared from controlled geometries of solid PbO bulk by in situ electrochemical reduction in choline chloride-ethylene glycol deep eutectic solvents at cell voltage 2.5 V and 353 K. The electrochemical behavior of PbO powders on cavity microelectrode was investigated by cyclic voltammetry. It is indicated that solid PbO can be directly reduced to metal in the solvent and a nucleation loop is apparent. Constant voltage electrolysis demonstrates that PbO pellet can be completely converted to metal for 13 h, and the current efficiency and specific energy consumption are about 87.79% and 736.82 kWh t-1, respectively. With the electro-deoxidation progress on the pellet surface, the reduction rate reaches the fastest and decreases along the distance from surface to inner center. The morphologies of metallic products are porous and mainly consisted of uniform particles which connect with each other by finer strip-shaped grains to remain the geometry and macro size constant perfectly. In addition, an empirical model of the electro-deoxidation process from spherical PbO bulk to porous lead is also proposed. These findings provide a novel and simple route for the preparation of porous metals from oxide precursors in deep eutectic solvents at room temperature.

Poly(vinyl Alcohol) Borate Gel Polymer Electrolytes Prepared by Electrodeposition and Their Application in Electrochemical Supercapacitors.

PubMed

Jiang, Mengjin; Zhu, Jiadeng; Chen, Chen; Lu, Yao; Ge, Yeqian; Zhang, Xiangwu

2016-02-10

Gel polymer electrolytes (GPEs) have been studied for preparing flexible and compact electrochemical energy storage devices. However, the preparation and use of GPEs are complex, and most GPEs prepared through traditional methods do not have good wettability with the electrodes, which retard them from achieving their performance potential. In this study, these problems are addressed by conceiving and implementing a simple, but effective, method of electrodepositing poly(vinyl alcohol) potassium borate (PVAPB) GPEs directly onto the surfaces of active carbon electrodes for electrochemical supercapacitors. PVAPB GPEs serve as both the electrolyte and the separator in the assembled supercapacitors, and their scale and shape are determined solely by the geometry of the electrodes. PVAPB GPEs have good bonding to the active electrode materials, leading to excellent and stable electrochemical performance of the supercapacitors. The electrochemical performance of PVAPB GPEs and supercapacitors can be manipulated simply by adjusting the concentration of KCl salt used during the electrodeposition process. With a 0.9 M KCl concentration, the as-prepared supercapacitors deliver a specific capacitance of 65.9 F g(-1) at a current density of 0.1 A g(-1) and retain more than 95% capacitance after 2000 charge/discharge cycles at a current density of 1 A g(-1). These supercapacitors also exhibit intelligent high voltage self-protection function due to the electrolysis-induced cross-linking effect of PVAPB GPEs.

Preparation of Lead Compounds: An Exercise in Applied Chemistry.

ERIC Educational Resources Information Center

Laing, Michael; And Others

1987-01-01

Describes an exercise developed at the University of Natal (South Africa) in which students visit a plant which manufactures a variety of lead compounds. Outlines the procedures for the laboratory preparation of lead compounds that students prepare with samples they collected at the plant. (TW)

Analysis and comparison of focused ion beam milling and vibratory polishing sample surface preparation methods for porosity study of U-Mo plate fuel for research and test reactors.

PubMed

Westman, Bjorn; Miller, Brandon; Jue, Jan-Fong; Aitkaliyeva, Assel; Keiser, Dennis; Madden, James; Tucker, Julie D

2018-07-01

Uranium-Molybdenum (U-Mo) low enriched uranium (LEU) fuels are a promising candidate for the replacement of high enriched uranium (HEU) fuels currently in use in a high power research and test reactors around the world. Contemporary U-Mo fuel sample preparation uses focused ion beam (FIB) methods for analysis of fission gas porosity. However, FIB possess several drawbacks, including reduced area of analysis, curtaining effects, and increased FIB operation time and cost. Vibratory polishing is a well understood method for preparing large sample surfaces with very high surface quality. In this research, fission gas porosity image analysis results are compared between samples prepared using vibratory polishing and FIB milling to assess the effectiveness of vibratory polishing for irradiated fuel sample preparation. Scanning electron microscopy (SEM) imaging was performed on sections of irradiated U-Mo fuel plates and the micrographs were analyzed using a fission gas pore identification and measurement script written in MatLab. Results showed that the vibratory polishing method is preferentially removing material around the edges of the pores, causing the pores to become larger and more rounded, leading to overestimation of the fission gas porosity size. Whereas, FIB preparation tends to underestimate due to poor micrograph quality and surface damage leading to inaccurate segmentations. Despite the aforementioned drawbacks, vibratory polishing remains a valid method for porosity analysis sample preparation, however, improvements should be made to reduce the preferential removal of material surrounding pores in order to minimize the error in the porosity measurements. Copyright © 2018 Elsevier Ltd. All rights reserved.

Kinetics of oil saponification by lead salts in ancient preparations of pharmaceutical lead plasters and painting lead mediums.

PubMed

Cotte, M; Checroun, E; Susini, J; Dumas, P; Tchoreloff, P; Besnard, M; Walter, Ph

2006-12-15

Lead soaps can be found in archaeological cosmetics as well as in oil paintings, as product of interactions of lead salts with oil. In this context, a better understanding of the formation of lead soaps allows a follow-up of the historical evolution of preparation recipes and provides new insights into conservation conditions. First, ancient recipes of both pharmaceutical lead plasters and painting lead mediums, mixtures of oil and lead salts, were reconstructed. The ester saponification by lead salts is determined by the preparation parameters which were quantified by FT-IR spectrometry. In particular, ATR/FT-IR spectrometer was calibrated by the standard addition method to quantitatively follow the kinetics of this reaction. The influence of different parameters such as temperature, presence of water and choice of lead salts was assessed: the saponification is clearly accelerated by water and heating. This analysis provides chemical explanations to the historical evolution of cosmetic and painting preparation recipes.

Preparing ultrafine PbS powders from the scrap lead-acid battery by sulfurization and inert gas condensation

NASA Astrophysics Data System (ADS)

Xia, Huipeng; Zhan, Lu; Xie, Bing

2017-02-01

A novel method for preparing ultrafine PbS powders involving sulfurization combined with inert gas condensation is developed in this paper, which is applicable to recycle Pb from lead paste of spent lead-acid batteries. Initially, the effects of the evaporation and condensation temperature, the inert gas pressure, the condensation distance and substrate on the morphology of as-obtained PbS ultrafine particles are intensively investigated using sulfur powders and lead particles as reagents. Highly dispersed and homogeneous PbS nanoparticles can be prepared under the optimized conditions which are 1223 K heating temperature, 573 K condensation temperature, 100 Pa inert gas pressure and 60 cm condensation distance. Furthermore, this method is successfully applied to recycle Pb from the lead paste of spent lead acid battery to prepare PbS ultrafine powders. This work does not only provide the theoretical fundamental for PbS preparation, but also provides a novel and efficient method for recycling spent lead-acid battery with high added-value products.

Efficient methylammonium lead iodide perovskite solar cells with active layers from 300 to 900 nm

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

Momblona, C.; Malinkiewicz, O.; Soriano, A.

2014-08-01

Efficient methylammonium lead iodide perovskite-based solar cells have been prepared in which the perovskite layer is sandwiched in between two organic charge transporting layers that block holes and electrons, respectively. This configuration leads to stable and reproducible devices that do not suffer from strong hysteresis effects and when optimized lead to efficiencies close to 15%. The perovskite layer is formed by using a dual-source thermal evaporation method, whereas the organic layers are processed from solution. The dual-source thermal evaporation method leads to smooth films and allows for high precision thickness variations. Devices were prepared with perovskite layer thicknesses ranging frommore » 160 to 900 nm. The short-circuit current observed for these devices increased with increasing perovskite layer thickness. The main parameter that decreases with increasing perovskite layer thickness is the fill factor and as a result optimum device performance is obtained for perovskite layer thickness around 300 nm. However, here we demonstrate that with a slightly oxidized electron blocking layer the fill factor for the solar cells with a perovskite layer thickness of 900 nm increases to the same values as for the devices with thin perovskite layers. As a result the power conversion efficiencies for the cells with 300 and 900 nm are very similar, 12.7% and 12%, respectively.« less

Fetal endocrinology

PubMed Central

Kota, Sunil Kumar; Gayatri, Kotni; Jammula, Sruti; Meher, Lalit Kumar; Kota, Siva Krishna; Krishna, S. V. S.; Modi, Kirtikumar D.

2013-01-01

Successful outcome of pregnancy depends upon genetic, cellular, and hormonal interactions, which lead to implantation, placentation, embryonic, and fetal development, parturition and fetal adaptation to extrauterine life. The fetal endocrine system commences development early in gestation and plays a modulating role on the various physiological organ systems and prepares the fetus for life after birth. Our current article provides an overview of the current knowledge of several aspects of this vast field of fetal endocrinology and the role of endocrine system on transition to extrauterine life. We also provide an insight into fetal endocrine adaptations pertinent to various clinically important situations like placental insufficiency and maternal malnutrition. PMID:23961471

Green Aspects of Techniques for the Determination of Currently Used Pesticides in Environmental Samples

PubMed Central

Stocka, Jolanta; Tankiewicz, Maciej; Biziuk, Marek; Namieśnik, Jacek

2011-01-01

Pesticides are among the most dangerous environmental pollutants because of their stability, mobility and long-term effects on living organisms. Their presence in the environment is a particular danger. It is therefore crucial to monitor pesticide residues using all available analytical methods. The analysis of environmental samples for the presence of pesticides is very difficult: the processes involved in sample preparation are labor-intensive and time-consuming. To date, it has been standard practice to use large quantities of organic solvents in the sample preparation process; but as these solvents are themselves hazardous, solvent-less and solvent-minimized techniques are becoming popular. The application of Green Chemistry principles to sample preparation is primarily leading to the miniaturization of procedures and the use of solvent-less techniques, and these are discussed in the paper. PMID:22174632

PLE in the analysis of plant compounds. Part I. The application of PLE for HPLC analysis of caffeine in green tea leaves.

PubMed

Dawidowicz, Andrzej L; Wianowska, Dorota

2005-04-29

A broad spectrum of sample preparation methods is currently used for the isolation of pharmacologically active compounds from plant and herbal materials. The paper compares the effectiveness of infusion, microwave assisted solvent extraction (MASE), matrix solid-phase dispersion (MSPD) and pressurised liquid extraction (PLE) as sample preparation methods for the isolation of caffeine from green tea leaves. The effect of PLE variables, such as extraction temperature, pressure and time, on the yield of caffeine from the investigated matrix is discussed. The obtained results revealed that PLE, in comparison with other sample preparation methods applied, has significantly lower efficacy for caffeine isolation from green tea leaves. The evaluation of PLE conditions leads to the conclusion that elevated pressure applied in the PLE process is the factor hindering the extraction.

Glazed clay pottery and lead exposure in Mexico: Current experimental evidence.

PubMed

Diaz-Ruiz, Araceli; Tristán-López, Luis Antonio; Medrano-Gómez, Karen Itzel; Torres-Domínguez, Juan Alejandro; Ríos, Camilo; Montes, Sergio

2017-11-01

Lead exposure remains a significant environmental problem; lead is neurotoxic, especially in developing humans. In Mexico, lead in human blood is still a concern. Historically, much of the lead exposure is attributed to the use of handcrafted clay pottery for cooking, storing and serving food. However, experimental cause-and-effect demonstration is lacking. The present study explores this issue with a prospective experimental approach. We used handcrafted clay containers to prepare and store lemonade, which was supplied as drinking water to pregnant rats throughout the gestational period. We found that clay pots, jars, and mugs leached on average 200 µg/l lead, and exposure to the lemonade resulted in 2.5 µg/dl of lead in the pregnant rats' blood. Neonates also showed increased lead content in the hippocampus and cerebellum. Caspase-3 activity was found to be statistically increased in the hippocampus in prenatally exposed neonates, suggesting increased apoptosis in that brain region. Glazed ceramics are still an important source of lead exposure in Mexico, and our results confirm that pregnancy is a vulnerable period for brain development.

Cryogenic experiences during W7-X HTS-current lead tests

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

Richter, Thomas; Lietzow, Ralph

2014-01-29

The Karlsruhe Institute of Technology (KIT) was responsible for design, production and test of the High Temperature Superconductor (HTS) current leads (CL) for the stellerator Wendelstein 7-X (W7-X). 16 current leads were delivered. Detailed prototype tests as well as the final acceptance tests were performed at KIT, using a dedicated test cryostat assembled beside and connected to the main vacuum vessel of the TOSKA facility. A unique feature is the upside down orientation of the current leads due to the location of the power supplies in the basement of the experimental area of W7-X. The HTS-CL consists of three mainmore » parts: the cold end for the connection to the bus bar at 4.5 K, the HTS part operating in the temperature range from 4.5 K to 65 K and a copper heat exchanger (HEX) in the temperature range from 65 K to room temperature, which is cooled with 50 K helium. Therefore in TOSKA it is possible to cool test specimens simultaneously with helium at two different temperature levels. The current lead tests included different scenarios with currents up to 18.2 kA. In total, 10 cryogenic test campaigns with a total time of about 24 weeks were performed till beginning of 2013. The test facility as well as the 2 kW cryogenic plant of ITEP showed a very good reliability. However, during such a long and complex experimental campaign, one has to deal with failures, technical difficulties and incidents. The paper gives a summary of the test performance comprising the test preparation and operation. This includes the performance and reliability of the refrigerator and the test facility with reference to the process measuring and control system, the data acquisition system, as well as the building infrastructure.« less

Charge Transport between Coupling Colloidal Perovskite Quantum Dots Assisted by Functional Conjugated Ligands.

PubMed

Dai, Jinfei; Xi, Jun; Li, Lu; Zhao, JingFeng; Shi, Yifei; Zhang, Wenwen; Ran, Chenxin; Jiao, Bo; Hou, Xun; Duan, Xinhua; Wu, Zhaoxin

2018-05-14

Long alkyl-chain capping ligands are indispensable for preparing stable colloidal quantum dots. However, its insulating feature blocks efficient carrier transport among QDs, leading to inferior performance in light-emitting diodes (LEDs). The trade-off between conductivity and colloidal stability of QDs has now been overcome. Methylamine lead bromide (MAPbBr 3 ) QDs with a conjugated alkyl-amine, 3-phenyl-2-propen-1-amine (PPA), as ligands were prepared. Owing to electron cloud overlapping and the delocalization effect of conjugated molecules, the conductivity and carrier mobility of PPA-QDs films increased almost 22 times over that of OA-QD films without compromising colloidal stability and photoluminescence. PPA-QDs LEDs exhibit a maximum current efficiency of 9.08 cd A -1 , which is 8 times of that of OA-QDs LEDs (1.14 cd A -1 ). This work provides critical solution for the poor conductivity of QDs in applications of energy-related devices. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Preparation of polyaniline/PbS core-shell nano/microcomposite and its application for photocatalytic H2 electrogeneration from H2O.

PubMed

Rabia, Mohamed; Mohamed, H S H; Shaban, Mohamed; Taha, S

2018-01-18

Lead sulfide (PbS) and polyaniline (PANI) nano/microparticles were prepared. Then, PANI/PbS core-shell nano/microcomposites (I, II, and III) were prepared by oxidative polymerization of different aniline concentrations (0.01, 0.03, and 0.05 M), respectively, in the presence of 0.05 M PbS. FT-IR, XRD, SEM, HR-TEM, and UV-Vis analyses were carried out to characterize the samples. From the FT-IR data, there are redshifts in PbS and PANI nano/microparticles bands in comparison with PANI/PbS nano/microcomposites. The average crystallite sizes of PANI/PbS core-shell nano/microcomposites (I, II, and III) from XRD analyses were 46.5, 55, and 42.16 nm, respectively. From the optical analyses, nano/microcomposite (II) has the optimum optical properties with two band gaps values of 1.41 and 2.79 eV. Then, the nano/microcomposite (II) membrane electrode supported on ITO glass was prepared and applied on the photoelectrochemical (PEC) H 2 generation from H 2 O. The characteristics current-voltage and current-time behaviors were measured at different wavelengths from 390 to 636 nm. Also, the incident photon-to-current conversion efficiency (IPCE) under monochromatic illumination condition was calculated. The optimum values for IPCE were 36.5 and 35.2% at 390 and 405 nm, respectively. Finally, a simple mechanism for PEC H 2 generation from H 2 O using the nano/microcomposite (II) membrane electrode was mentioned.

The upcycling of post-industrial PP/PET waste streams through in-situ microfibrillar preparation

NASA Astrophysics Data System (ADS)

Delva, Laurens; Ragaert, Kim; Cardon, Ludwig

2015-12-01

Post-industrial plastic waste streams can be re-used as secondary material streams for polymer processing by extrusion or injection moulding. One of the major commercially available waste stream contains polypropylene (PP) contaminated with polyesters (mostly polyethylene tereftalate - PET). An important practical hurdle for the direct implementation of this waste stream is the immiscibility of PP and PET in the melt, which leads to segregation within the polymer structure and adversely affects the reproducibility and mechanical properties of the manufactured parts. It has been indicated in literature that the creation of PET microfibrils in the PP matrix could undo these drawbacks and upcycle the PP/PET combination. Within the current research, a commercially available virgin PP/PET was evaluated for the microfibrillar preparation. The mechanical (tensile and impact) properties, thermal properties and morphology of the composites were characterized at different stages of the microfibrillar preparation.

Challenges in making a seismic hazard map for Alaska and the Aleutians

USGS Publications Warehouse

Wesson, R.L.; Boyd, O.S.; Mueller, C.S.; Frankel, A.D.; Freymueller, J.T.

2008-01-01

We present a summary of the data and analyses leading to the revision of the time-independent probabilistic seismic hazard maps of Alaska and the Aleutians. These maps represent a revision of existing maps based on newly obtained data, and reflect best current judgments about methodology and approach. They have been prepared following the procedures and assumptions made in the preparation of the 2002 National Seismic Hazard Maps for the lower 48 States, and will be proposed for adoption in future revisions to the International Building Code. We present example maps for peak ground acceleration, 0.2 s spectral amplitude (SA), and 1.0 s SA at a probability level of 2% in 50 years (annual probability of 0.000404). In this summary, we emphasize issues encountered in preparation of the maps that motivate or require future investigation and research.

40 CFR 1508.16 - Lead agency.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 34 2012-07-01 2012-07-01 false Lead agency. 1508.16 Section 1508.16 Protection of Environment COUNCIL ON ENVIRONMENTAL QUALITY TERMINOLOGY AND INDEX § 1508.16 Lead agency. Lead agency means the agency or agencies preparing or having taken primary responsibility for preparing the...

40 CFR 1508.16 - Lead agency.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 33 2011-07-01 2011-07-01 false Lead agency. 1508.16 Section 1508.16 Protection of Environment COUNCIL ON ENVIRONMENTAL QUALITY TERMINOLOGY AND INDEX § 1508.16 Lead agency. Lead agency means the agency or agencies preparing or having taken primary responsibility for preparing the...

40 CFR 1508.16 - Lead agency.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 33 2014-07-01 2014-07-01 false Lead agency. 1508.16 Section 1508.16 Protection of Environment COUNCIL ON ENVIRONMENTAL QUALITY TERMINOLOGY AND INDEX § 1508.16 Lead agency. Lead agency means the agency or agencies preparing or having taken primary responsibility for preparing the...

40 CFR 1508.16 - Lead agency.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 34 2013-07-01 2013-07-01 false Lead agency. 1508.16 Section 1508.16 Protection of Environment COUNCIL ON ENVIRONMENTAL QUALITY TERMINOLOGY AND INDEX § 1508.16 Lead agency. Lead agency means the agency or agencies preparing or having taken primary responsibility for preparing the...

40 CFR 1508.16 - Lead agency.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Lead agency. 1508.16 Section 1508.16 Protection of Environment COUNCIL ON ENVIRONMENTAL QUALITY TERMINOLOGY AND INDEX § 1508.16 Lead agency. Lead agency means the agency or agencies preparing or having taken primary responsibility for preparing the...

Electrochemical behavior of negative electrode of lead-acid cells based on reticulated vitreous carbon carrier

NASA Astrophysics Data System (ADS)

Czerwiński, A.; Obrębowski, S.; Kotowski, J.; Rogulski, Z.; Skowroński, J. M.; Krawczyk, P.; Rozmanowski, T.; Bajsert, M.; Przystałowski, M.; Buczkowska-Biniecka, M.; Jankowska, E.; Baraniak, M.

Reticulated vitreous carbon (RVC ®) and RVC ® plated with lead were investigated as carriers for the negative electrode of lead-acid cell. The RVC ® and Pb/RVC ® carriers were pasted with active paste (received from JENOX Ltd., Polish producer of lead-acid batteries) and prepared to be used in lead-acid cell. Comparative study of electrodes based on RVC ® and Pb/RVC ® has been done using constant-current charging/discharging, constant-potential discharging and cycling voltammetry measurements. Scanning electron microscopy (SEM) was employed to determine the morphology of the lead layer deposited on the RVC surface. Hybrid flooded single lead-acid cells containing one negative electrode, based on new type of carrier (RVC ® or Pb/RVC ®), sandwiched between two positive electrodes, based on the Pb-Ca grids, were assembled and subjected to electrochemical tests. It has been found that both materials, RVC ® and Pb/RVC ®, can be used as carriers of negative electrode, but the latter seems to have better influence on the discharge performance.

Preparation of PCDTBT nanofibers with a diameter of 20 nm and their application to air-processed organic solar cells.

PubMed

Kim, Taehoon; Yang, Seung Jae; Kim, Sung Kyun; Choi, Hong Soo; Park, Chong Rae

2014-03-07

A strategy for fabricating organic photovoltaic (OPV) devices based on PCDTBT nanofibers and PC70BM is described. Electrospinning techniques are used to prepare PCDTBT nanofibers and OPV devices in ambient air. The diameters of the PCDTBT nanofibers are approximately twice the exciton diffusion length, 20 nm. The active layer exhibits 100% photoluminescence quenching due to the small nanofiber diameter, indicating that the excitons are efficiently dissociated. The electrospun PCDTBT nanofibers absorb more photons at longer wavelengths, leading to improved photon harvesting. OPV devices composed of PCDTBT nanofibers show a high short circuit current of 11.54 mA cm(-2) and a high power conversion efficiency of 5.82%. The increase in the short circuit current is attributed to enhanced photon harvesting and charge transport. This method may be applied to the fabrication, in ambient air, of large-area active layers composed of other new conjugated polymers to yield high-performance OPV devices.

Chemical modification of birch allergen extract leads to a reduction in allergenicity as well as immunogenicity.

PubMed

Würtzen, Peter Adler; Lund, Lise; Lund, Gitte; Holm, Jens; Millner, Anders; Henmar, Helene

2007-01-01

In Europe, specific immunotherapy is currently conducted with vaccines containing allergen preparations based on intact extracts. In addition to this, chemically modified allergen extracts (allergoids) are used for specific allergy treatment. Reduced allergenicity and thereby reduced risk of side effects in combination with retained ability to activate T cells and induce protective allergen-specific antibody responses has been claimed for allergoids. In the current study, we compared intact allergen extracts and allergoids with respect to allergenicity and immunogenicity. The immunological response to birch allergen extract, alum-adsorbed extract, birch allergoid and alum-adsorbed allergoid was investigated in vitro in human basophil histamine release assay and by stimulation of human allergen-specific T cell lines. In vivo, Bet v 1-specific IgG titers in mice were determined after repetitive immunizations. In all patients tested (n = 8), allergoid stimulations led to reduced histamine release compared to the intact allergen extract. However, the allergoid preparations were not recognized by Bet v 1-specific T cell lines (n = 7), which responded strongly to the intact allergen extract. Mouse immunizations showed a clearly reduced IgG induction by allergoids and a strongly potentiating effect of the alum adjuvant. Optimal IgG titers were obtained after 3 immunizations with intact allergen extracts, while 5 immunizations were needed to obtain maximal response to the allergoid. The reduced histamine release observed for allergoid preparations may be at the expense of immunological efficacy because the chemical modifications lead to a clear reduction in T cell activation and the ability to induce allergen-specific IgG antibody responses. Copyright 2007 S. Karger AG, Basel.

Influence of residual elements in lead on oxygen- and hydrogen-gassing rates of lead-acid batteries

NASA Astrophysics Data System (ADS)

Lam, L. T.; Ceylan, H.; Haigh, N. P.; Lwin, T.; Rand, D. A. J.

Raw lead materials contain many residual elements. With respect to setting 'safe' levels for these elements, each country has its own standard, but the majority of the present specifications for the lead used to prepare battery oxide apply to flooded batteries that employ antimonial grids. In these batteries, the antimony in the positive and negative grids dominates gassing characteristics so that the influence of residual elements is of little importance. This is, however, not the case for valve-regulated lead-acid (VRLA) batteries, which use antimony-free grids and less sulfuric acid solution. Thus, it is necessary to specify 'acceptable' levels of residual elements for the production of VRLA batteries. In this study, 17 elements are examined, namely: antimony, arsenic, bismuth, cadmium, chromium, cobalt, copper, germanium, iron, manganese, nickel, selenium, silver, tellurium, thallium, tin, and zinc. The following strategy has been formulated to determine the acceptable levels: (i) selection of a control oxide; (ii) determination of critical float, hydrogen and oxygen currents; (iii) establishment of a screening plan for the elements; (iv) development of a statistical method for analysis of the experimental results. The critical values of the float, hydrogen and oxygen currents are calculated from a field survey of battery failure data. The values serve as a base-line for comparison with the corresponding measured currents from cells using positive and negative plates produced either from the control oxide or from oxide doped with different levels of the 17 elements in combination. The latter levels are determined by means of a screening plan which is based on the Plackett-Burman experimental design. Following this systematic and thorough exercise, two specifications are proposed for the purity of the lead to be used in oxide production for VRLA technology.

Buried structure for increasing fabrication performance of micromaterial by electromigration

NASA Astrophysics Data System (ADS)

Kimura, Yasuhiro; Saka, Masumi

2016-06-01

The electromigration (EM) technique is a physical synthetic growth method for micro/nanomaterials. EM causes atomic diffusion in a metal line by high-density electron flows. The intentional control of accumulation and relaxation of atoms by EM can lead to the fabrication of a micro/nanomaterial. TiN passivation has been utilized as a component of sample in the EM technique. Although TiN passivation can simplify the cumbersome processes for preparing the sample, the leakage of current naturally occurs because of the conductivity of TiN as a side effect and decreases the performance of micro/nanomaterial fabrication. In the present work, we propose a buried structure, which contributes to significantly decreasing the current for fabricating an Al micromaterial by confining the current flow in the EM technique. The fabrication performance was evaluated based on the threshold current for fabricating an Al micromaterial using the buried structure and the previous structure with the leakage of current.

Developing the skills required for evidence-based practice.

PubMed

French, B

1998-01-01

The current health care environment requires practitioners with the skills to find and apply the best currently available evidence for effective health care, to contribute to the development of evidence-based practice protocols, and to evaluate the impact of utilizing validated research findings in practice. Current approaches to teaching research are based mainly on gaining skills by participation in the research process. Emphasis on the requirement for rigour in the process of creating new knowledge is assumed to lead to skill in the process of using research information created by others. This article reflects upon the requirements for evidence-based practice, and the degree to which current approaches to teaching research prepare practitioners who are able to find, evaluate and best use currently available research information. The potential for using the principles of systematic review as a teaching and learning strategy for research is explored, and some of the possible strengths and weakness of this approach are highlighted.

Debridement and wound bed preparation.

PubMed

Falabella, Anna F

2006-01-01

Debridement can play a vital role in wound bed preparation and the removal of barriers that impair wound healing. In accordance with the TIME principles, debridement can help remove nonviable tissue, control inflammation or infection, decrease excess moisture, and stimulate a nonadvancing wound edge. There are many types of debridement, each with a set of advantages and disadvantages that must be clearly understood by the healthcare team. Failure to use the correct debridement method for a given type of wound may lead to further delays in healing, increase patient suffering, and unnecessarily increase the cost of care. This review article discusses the various methods of debridement, describes currently available debriding agents, evaluates the clinical data regarding their efficacy and safety, and describes strategies for the management of problematic nonhealing wounds.

The state of cell block variation and satisfaction in the era of molecular diagnostics and personalized medicine

PubMed Central

Crapanzano, John P.; Heymann, Jonas J.; Monaco, Sara; Nassar, Aziza; Saqi, Anjali

2014-01-01

Background: In the recent past, algorithms and recommendations to standardize the morphological, immunohistochemical and molecular classification of lung cancers on cytology specimens have been proposed, and several organizations have recommended cell blocks (CBs) as the preferred modality for molecular testing. Based on the literature, there are several different techniques available for CB preparation-suggesting that there is no standard. The aim of this study was to conduct a survey of CB preparation techniques utilized in various practice settings and analyze current issues, if any. Materials and Methods: A single E-mail with a link to an electronic survey was distributed to members of the American Society of Cytopathology and other pathologists. Questions pertaining to the participants’ practice setting and CBs-volume, method, quality and satisfaction-were included. Results: Of 95 respondents, 90/95 (94%) completed the survey and comprise the study group. Most participants practice in a community hospital/private practice (44%) or academic center (41%). On average, 14 CBs (range 0-50; median 10) are prepared by a laboratory daily. Over 10 methods are utilized: Plasma thrombin (33%), HistoGel (27%), Cellient automated cell block system (8%) and others (31%) respectively. Forty of 90 (44%) respondents are either unsatisfied or sometimes satisfied with their CB quality, with low-cellular yield being the leading cause of dissatisfaction. There was no statistical significance between the three most common CB preparation methods and satisfaction with quality. Discussion: Many are dissatisfied with their current method of CB preparation, and there is no consistent method to prepare CBs. In today's era of personalized medicine with an increasing array of molecular tests being applied to cytological specimens, there is a need for a standardized protocol for CB optimization to enhance cellularity. PMID:24799951

The state of cell block variation and satisfaction in the era of molecular diagnostics and personalized medicine.

PubMed

Crapanzano, John P; Heymann, Jonas J; Monaco, Sara; Nassar, Aziza; Saqi, Anjali

2014-01-01

In the recent past, algorithms and recommendations to standardize the morphological, immunohistochemical and molecular classification of lung cancers on cytology specimens have been proposed, and several organizations have recommended cell blocks (CBs) as the preferred modality for molecular testing. Based on the literature, there are several different techniques available for CB preparation-suggesting that there is no standard. The aim of this study was to conduct a survey of CB preparation techniques utilized in various practice settings and analyze current issues, if any. A single E-mail with a link to an electronic survey was distributed to members of the American Society of Cytopathology and other pathologists. Questions pertaining to the participants' practice setting and CBs-volume, method, quality and satisfaction-were included. Of 95 respondents, 90/95 (94%) completed the survey and comprise the study group. Most participants practice in a community hospital/private practice (44%) or academic center (41%). On average, 14 CBs (range 0-50; median 10) are prepared by a laboratory daily. Over 10 methods are utilized: Plasma thrombin (33%), HistoGel (27%), Cellient automated cell block system (8%) and others (31%) respectively. Forty of 90 (44%) respondents are either unsatisfied or sometimes satisfied with their CB quality, with low-cellular yield being the leading cause of dissatisfaction. There was no statistical significance between the three most common CB preparation methods and satisfaction with quality. Many are dissatisfied with their current method of CB preparation, and there is no consistent method to prepare CBs. In today's era of personalized medicine with an increasing array of molecular tests being applied to cytological specimens, there is a need for a standardized protocol for CB optimization to enhance cellularity.

The Effect of Telling Lies on Belief in the Truth

PubMed Central

Polage, Danielle

2017-01-01

The current study looks at the effect of telling lies, in contrast to simply planning lies, on participants’ belief in the truth. Participants planned and told a lie, planned to tell a lie but didn’t tell it, told an unplanned lie, or neither planned nor told a lie (control) about events that did not actually happen to them. Participants attempted to convince researchers that all of the stories told were true. Results show that telling a lie plays a more important role in inflating belief scores than simply preparing the script of a lie. Cognitive dissonance may lead to motivated forgetting of information that does not align with the lie. This research suggests that telling lies may lead to confusion as to the veracity of the lie leading to inflated belief scores. PMID:29358979

Preparation and Elastic Moduli of Germanate Glass Containing Lead and Bismuth

PubMed Central

Sidek, Hj A. A.; Bahari, Hamid R.; Halimah, Mohamed K.; Yunus, Wan M. M.

2012-01-01

This paper reports the rapid melt quenching technique preparation for the new family of bismuth-lead germanate glass (BPG) systems in the form of (GeO2)60–(PbO)40−x–(½Bi2O3)x where x = 0 to 40 mol%. Their densities with respect of Bi2O3 concentration were determined using Archimedes’ method with acetone as a floatation medium. The current experimental data are compared with those of bismuth lead borate (B2O3)20–(PbO)80−x–(Bi2O3)x. The elastic properties of BPG were studied using the ultrasonic pulse-echo technique where both longitudinal and transverse sound wave velocities have been measured in each glass samples at a frequency of 15 MHz and at room temperature. Experimental data shows that all the physical parameters of BPG including density and molar volume, both longitudinal and transverse velocities increase linearly with increasing of Bi2O3 content in the germanate glass network. Their elastic moduli such as longitudinal, shear and Young’s also increase linearly with addition of Bi2O3 but the bulk modulus did not. The Poisson’s ratio and fractal dimensionality are also found to vary linearly with the Bi2O3 concentration. PMID:22606000

Preparation and elastic moduli of germanate glass containing lead and bismuth.

PubMed

Sidek, Hj A A; Bahari, Hamid R; Halimah, Mohamed K; Yunus, Wan M M

2012-01-01

This paper reports the rapid melt quenching technique preparation for the new family of bismuth-lead germanate glass (BPG) systems in the form of (GeO(2))(60)-(PbO)(40-) (x)-(½Bi(2)O(3))(x) where x = 0 to 40 mol%. Their densities with respect of Bi(2)O(3) concentration were determined using Archimedes' method with acetone as a floatation medium. The current experimental data are compared with those of bismuth lead borate (B(2)O(3))(20)-(PbO)(80-) (x)-(Bi(2)O(3))(x). The elastic properties of BPG were studied using the ultrasonic pulse-echo technique where both longitudinal and transverse sound wave velocities have been measured in each glass samples at a frequency of 15 MHz and at room temperature. Experimental data shows that all the physical parameters of BPG including density and molar volume, both longitudinal and transverse velocities increase linearly with increasing of Bi(2)O(3) content in the germanate glass network. Their elastic moduli such as longitudinal, shear and Young's also increase linearly with addition of Bi(2)O(3) but the bulk modulus did not. The Poisson's ratio and fractal dimensionality are also found to vary linearly with the Bi(2)O(3) concentration.

A Course To Prepare Peer Leaders To Implement a Student-Assisted Learning Method

NASA Astrophysics Data System (ADS)

Tien, Lydia T.; Roth, Vicki; Kampmeier, J. A.

2004-09-01

This article reports our efforts to develop a two-credit course to train undergraduate students to implement a new pedagogical model, Peer-Led Team Learning (PLTL). The leader training course is a collaborative effort of faculty and educational specialists to join pedagogy and chemistry. The syllabus is grounded in the research literature and situated in the context of the specific course in which the peer leaders will work, leading a weekly Workshop. Since the peer leaders take the training course while they are working as leaders, the pedagogical ideas find immediate application. We have taught the course since 1995 to more than 250 undergraduate and graduate students. In practice, our training course is the central mechanism to transform students from Workshop participants to skilled Workshop leaders. In turn, these carefully prepared peer leaders are essential forces for curricular change. In addition to the immediate practical benefits, the training course leads to new working relationships among students, faculty, and educational specialists. As a result, the training course becomes a mechanism to introduce current faculty to a new research literature and to encourage the development of future faculty.

Leader-Member Exchange Relationships in Health Information Management

PubMed Central

Hunt, T.J.

2014-01-01

This article seeks to raise awareness of the leader-member exchange (LMX) theory of leadership and its potential benefit to the health information management (HIM) profession. A literature review that was conducted identified a leadership challenge for HIM practitioners. The review also provides examples of leadership definitions, and potential benefits of LMX to HIM professionals in leading people and influencing leaders in their organizations. The LMX concept may be an avenue to investigate in preparing future and current HIM professionals for leadership. PMID:24808805

Leader-member exchange relationships in health information management.

PubMed

Hunt, T J

2014-01-01

This article seeks to raise awareness of the leader-member exchange (LMX) theory of leadership and its potential benefit to the health information management (HIM) profession. A literature review that was conducted identified a leadership challenge for HIM practitioners. The review also provides examples of leadership definitions, and potential benefits of LMX to HIM professionals in leading people and influencing leaders in their organizations. The LMX concept may be an avenue to investigate in preparing future and current HIM professionals for leadership.

Rapid immunocytochemistry based on alternating current electric field using squash smear preparation of central nervous system tumors.

PubMed

Moriya, Jun; Tanino, Mishie Ann; Takenami, Tomoko; Endoh, Tomoko; Urushido, Masana; Kato, Yasutaka; Wang, Lei; Kimura, Taichi; Tsuda, Masumi; Nishihara, Hiroshi; Tanaka, Shinya

2016-01-01

The role of intraoperative pathological diagnosis for central nervous system (CNS) tumors is crucial for neurosurgery when determining the surgical procedure. Especially, treatment of carmustine (BCNU) wafers requires a conclusive diagnosis of high-grade glioma proven by intraoperative diagnosis. Recently, we demonstrated the usefulness of rapid immunohistochemistry (R-IHC) that facilitates antigen-antibody reaction under alternative current (AC) electric field in the intraoperative diagnosis of CNS tumors; however, a higher proportion of water and lipid in the brain parenchyma sometimes leads to freezing artifacts, resulting in poor quality of frozen sections. On the other hand, squash smear preparation of CNS tumors for cytology does not affect the frozen artifacts, and the importance of smear preparation is now being re-recognized as being better than that of the tissue sections. In this study, we established the rapid immunocytochemistry (R-ICC) protocol for squash smears of CNS tumors using AC electric field that takes only 22 min, and demonstrated its usefulness for semi-quantitative Ki-67/MIB-1 labeling index and CD 20 by R-ICC for intraoperative diagnosis. R-ICC by AC electric field may become a substantial tool for compensating R-IHC and will be applied for broad antibodies in the future.

Teaching, Learning, and Leading with Schools and Communities: Preparing Sophisticated and Resilient Elementary STEM Educators

ERIC Educational Resources Information Center

Smetana, Lara K.; Coleman, Elizabeth R.; Ryan, Ann Marie; Tocci, Charles

2013-01-01

Loyola University Chicago's Teaching, Learning, and Leading With Schools and Communities (TLLSC) program is an ambitious break from traditional university-based teacher preparation models. This clinically based initial teacher preparation program, fully embedded in local schools and community organizations, takes an ecological perspective on the…

Medical management of heavy menstrual bleeding

PubMed Central

Maybin, Jacqueline A; Critchley, Hilary OD

2016-01-01

Women with benign heavy menstrual bleeding have the choice of a number of medical treatment options to reduce their blood loss and improve quality of life. The role of the clinician is to provide information to facilitate women in making an appropriate choice. Unfortunately, many options can be associated with hormonal side effects, prevention of fertility and lack of efficacy, leading to discontinuation and progression to surgical interventions. Herein, we discuss the various options currently available to women, including antifibrinolytics, nonsteroidal anti-inflammatory preparations, oral contraceptive pills and oral, injectable and intrauterine progestogens. In addition, we describe the more novel option of selective progesterone receptor modulators and their current benefits and limitations. PMID:26695687

Quality control evaluation of Keshamasi, Keshanjana and Keshamasi eye ointment.

PubMed

Dhiman, Kartar Singh; Shukla, Vinay J; Bhalodia, Nayan R; Sharma, Vinay R

2014-01-01

Keshanjana (collyrium) is a well known Ayurvedic preparation prepared out of Keshamasi (ash prepared by scalp hairs) mixed with Goghrita (cow's ghee). This medicine is indicated for the treatment of Shushkakshipaka (dry eye syndrome) in the classical literature of Ayurveda; hence, it was under taken for standardization and clinical evaluation in an extra-mural research project from Central Council for Research in Ayurvedic Sciences, Department of AYUSH, New Delhi. To develop standard quality parameters for the Keshamasi, Keshanjana and Keshamasi ointment. Scalp hairs of male and females collected from saloons were converted to classical Masi Kalpana and mixed with cow ghee and petrolatum in the ratio of 1:5 to prepare the Keshanjana and Keshamasi ointment respectively. Standard Operation Procedure (SOP) were adopted and recorded accordingly. The raw material, furnished products and plain Goghrita were subjected for quality control parameters i.e., physico-chemical evaluation, anti-microbial study, particle size analysis, heavy metal analysis through inductive couple plasma spectroscopy with high performance thin layer liquid chromatography fingerprints. Rancidity was negative in all the samples, indicating that the physico-chemical parameters are in acceptable range. Lead and zinc were present in most of the samples; while all samples are were free from microbial contamination. As no standards are available to compare the results of the current study, the observations cannot be compared. Thus the profile generated in the current study can be considered as standard to refer in future studies.

Quality control evaluation of Keshamasi, Keshanjana and Keshamasi eye ointment

PubMed Central

Dhiman, Kartar Singh; Shukla, Vinay J.; Bhalodia, Nayan R.; Sharma, Vinay R.

2014-01-01

Background: Keshanjana (collyrium) is a well known Ayurvedic preparation prepared out of Keshamasi (ash prepared by scalp hairs) mixed with Goghrita (cow's ghee). This medicine is indicated for the treatment of Shushkakshipaka (dry eye syndrome) in the classical literature of Ayurveda; hence, it was under taken for standardization and clinical evaluation in an extra-mural research project from Central Council for Research in Ayurvedic Sciences, Department of AYUSH, New Delhi. Aim: To develop standard quality parameters for the Keshamasi, Keshanjana and Keshamasi ointment. Materials and Methods: Scalp hairs of male and females collected from saloons were converted to classical Masi Kalpana and mixed with cow ghee and petrolatum in the ratio of 1:5 to prepare the Keshanjana and Keshamasi ointment respectively. Standard Operation Procedure (SOP) were adopted and recorded accordingly. The raw material, furnished products and plain Goghrita were subjected for quality control parameters i.e., physico-chemical evaluation, anti-microbial study, particle size analysis, heavy metal analysis through inductive couple plasma spectroscopy with high performance thin layer liquid chromatography fingerprints. Results: Rancidity was negative in all the samples, indicating that the physico-chemical parameters are in acceptable range. Lead and zinc were present in most of the samples; while all samples are were free from microbial contamination. Conclusion: As no standards are available to compare the results of the current study, the observations cannot be compared. Thus the profile generated in the current study can be considered as standard to refer in future studies. PMID:25364202

Current projects in Pre-analytics: where to go?

PubMed

Sapino, Anna; Annaratone, Laura; Marchiò, Caterina

2015-01-01

The current clinical practice of tissue handling and sample preparation is multifaceted and lacks strict standardisation: this scenario leads to significant variability in the quality of clinical samples. Poor tissue preservation has a detrimental effect thus leading to morphological artefacts, hampering the reproducibility of immunocytochemical and molecular diagnostic results (protein expression, DNA gene mutations, RNA gene expression) and affecting the research outcomes with irreproducible gene expression and post-transcriptional data. Altogether, this limits the opportunity to share and pool national databases into European common databases. At the European level, standardization of pre-analytical steps is just at the beginning and issues regarding bio-specimen collection and management are still debated. A joint (public-private) project entitled on standardization of tissue handling in pre-analytical procedures has been recently funded in Italy with the aim of proposing novel approaches to the neglected issue of pre-analytical procedures. In this chapter, we will show how investing in pre-analytics may impact both public health problems and practical innovation in solid tumour processing.

Herbal Medicines: challenges in the modern world. Part 5. status and current directions of complementary and alternative herbal medicine worldwide.

PubMed

Enioutina, Elena Yu; Salis, Emma R; Job, Kathleen M; Gubarev, Michael I; Krepkova, Lubov V; Sherwin, Catherine M T

2017-03-01

Herbal medicine (HM) use is growing worldwide. Single herb preparations, ethnic and modern HM formulations are widely used as adjunct therapies or to improve consumer wellbeing. Areas covered: This final part in the publication series summarizes common tendencies in HM use as adjunct or alternative medicine, education of healthcare professionals and consumers, current and proposed guidelines regulating of production. We discuss potential HM-HM and HM-drug interactions that could lead to severe adverse events in situations where HMs are taken without proper medical professional oversight. Expert commentary: A number of serious problems have arisen with the steady global increase in HM use. HM interaction with conventional drugs (CD) may result in inadequate dosing of CD or adverse reactions; HM-HM interaction within herbal supplements could lead to toxicity of formulations. Inadequate education of clinicians and patients regarding medicinal properties of HMs must be addressed regionally and globally to ensure consumer safety.

Comparative study of chitosan and chitosan-gelatin scaffold for tissue engineering

NASA Astrophysics Data System (ADS)

Kumar, Pawan; Dehiya, Brijnandan S.; Sindhu, Anil

2017-12-01

A number of orthopedic disorders and bone defect issues are solved by scaffold-based therapy in tissue engineering. The biocompatibility of chitosan (polysaccharide) and its similarity with glycosaminoglycan makes it a bone-grafting material. The current work focus on the synthesis of chitosan and chitosan-gelatin scaffold for hard tissue engineering. The chitosan and chitosan-gelatin scaffold have shown improved specific surface area, density, porosity, mechanical properties, biodegradability and absorption. These scaffolds can lead to the development or artificial fabrication of hard tissue alternates. The porous scaffold samples were prepared by freeze-drying method. The microstructure, mechanical and degradable properties of chitosan and chitosan-gelatin scaffolds were analyzed and results revealed that the scaffolds prepared from chitosan-gelatin can be utilized as a useful matrix for tissue engineering.

Synthesis and characterization of lead-free tin silver nanosolders and their application to halogen free nanosolder pastes

NASA Astrophysics Data System (ADS)

Wernicki, Evan

Solder paste is a key material used in attaching electronic components to printed circuit boards (PCBs). Commonly used lead-based solders, such as eutectic Sn/37Pb, are currently being replaced by lead-free alloy materials due to health and environmental concerns associated with lead. Many solder pastes, both lead-containing and lead-free, contain halogens which act as activators to remove surface oxide and enhance surface wetting, posing further environmental concern from the halogen species. Difficulties in obtaining reliable joints can occur since lead-free solder material candidates have higher melting temperatures (30-50 °C) than that of lead-based solders. Differences in material properties between the numerous materials used in assembly and packaging processes can lead to component damage during manufacturing. Furthermore, designs that include more electrical interconnects in smaller areas give rise for the need for new materials to allow this trend to continue. A surfactant-assisted chemical reduction method was used to synthesize Sn/Ag alloy nanoparticles with a target composition range of 3.5-5 wt% Ag that served as the lead-free solder material within a nanosolder paste. Structure and size characterization via SEM and TEM showed Sn-Ag nanosolders size average approximately 19 nm. Differential scanning calorimetry (DSC) measurements of the nanosolder samples containing 4.5 wt% Ag showed an endothermic peak at 222.5 °C and an onset of 219.2 °C, indicating up to 17.5 °C melting temperature depression when compared to the bulk liquidus value of 240 °C. Composition of the nanosolder material was confirmed using energy dispersive x-ray spectroscopy (EDS) and structures formed were analyzed via x-ray diffraction (XRD). Both halogen-free and halogen-containing flux materials were combined with the nanosolder material, respectively, with varying preparation parameters to form a design of experiments (DoE) for nanosolder paste preparation. Solder pastes prepared with 55, 70, and 85 wt% nanosolder material have been successfully printed and reflowed on Cu substrates to imitate current manufacturing process. Different peak reflow temperatures of 245 °C and 265 °C were used to observe the effect on solder paste spreading and wetting angle of reflowed solder features. Two different flux chemistries, halogen-free and halogen-based, were also studied. Statistical analysis indicated nanosolder loading had a strong impact on both the wetting angle and paste spreading after the reflow process. The wetting angles of the samples, from the highest to lowest weight percentage, resulted in values of 69.7°, 26.2°, and 0°. A 55 wt% nanosolder paste formed multiple reflowed solder bumps, compared to the single bumps obtained with 70 and 85 wt% nanosolders. The highest loading sample was found to spread the least. This can be attributed to a combination of factors such as higher paste viscosity and lower solder-solder surface tension interactions. A larger peak temperature resulted in larger paste spreading values proving to be significant, however it was not found to affect the resulting wetting angle significantly. Flux chemistry was found to statistically have no profound impact on either the wetting angle or the solder spread. Therefore, it was found that the halogen-free solder paste can act as a suitable replacement for the tested halogen-containing nanosolder paste samples. KEYWORDS : solder paste, nanoparticles, paste printing, lead-free, reflow.

McNutt to Be Nominated to Lead U.S. Geological Survey

NASA Astrophysics Data System (ADS)

Showstack, Randy

2009-07-01

U.S. President Barack Obama announced on 9 July his intention to nominate Marcia McNutt as director of the U.S. Geological Survey (USGS) and science advisor to the Secretary of the Interior. McNutt, who served as AGU president from 2000 to 2002, currently is president and chief executive officer of the Monterey Bay Aquarium Research Institute, in Moss Landing, Calif. “Scientific information from the U.S. Geological Survey is crucial to solving the most important problems facing society—finding sufficient supplies of fresh water and clean energy and providing accurate information that allows citizens to prepare intelligently for climate change. I look forward to leading such a respected institution at this critical time,” McNutt said.

M-type K+ currents in rat cultured thoracolumbar sympathetic neurones and their role in uracil nucleotide-evoked noradrenaline release

PubMed Central

Nörenberg, W; von Kügelgen, I; Meyer, A; Illes, P; Starke, K

2000-01-01

Cultured sympathetic neurones are depolarized and release noradrenaline in response to extracellular ATP, UDP and UTP. We examined the possibility that, in neurones cultured from rat thoracolumbar sympathetic ganglia, inhibition of the M-type potassium current might underlie the effects of UDP and UTP. Reverse transcriptase-polymerase chain reaction indicated that the cultured cells contained mRNA for P2Y2-, P2Y4- and P2Y6-receptors as well as for the KCNQ2- and KCNQ3-subunits which have been suggested to assemble into M-channels. In cultures of neurones taken from newborn as well as from 10 day-old rats, oxotremorine, the M-channel blocker Ba2+ and UDP all released previously stored [3H]-noradrenaline. The neurones possessed M-currents, the kinetic properties of which were similar in neurones from newborn and 9–12 day-old rats. UDP, UTP and ATP had no effect on M-currents in neurones prepared from newborn rats. Oxotremorine and Ba2+ substantially inhibited the current. ATP also had no effect on the M-current in neurones prepared from 9–12 day-old rats. Oxotremorine and Ba2+ again caused marked inhibition. In contrast to cultures from newborn animals, UDP and UTP attenuated the M-current in neurones from 9–12 day-old rats; however, the maximal inhibition was less than 30%. The results indicate that inhibition of the M-current is not involved in uracil nucleotide-induced transmitter release from rat cultured sympathetic neurones during early development. M-current inhibition may contribute to release at later stages, but only to a minor extent. The mechanism leading to noradrenaline release by UDP and UTP remains unknown. PMID:10683196

Enhanced electrocaloric analysis and energy-storage performance of lanthanum modified lead titanate ceramics for potential solid-state refrigeration applications.

PubMed

Zhang, Tian-Fu; Huang, Xian-Xiong; Tang, Xin-Gui; Jiang, Yan-Ping; Liu, Qiu-Xiang; Lu, Biao; Lu, Sheng-Guo

2018-01-10

The unique properties and great variety of relaxer ferroelectrics make them highly attractive in energy-storage and solid-state refrigeration technologies. In this work, lanthanum modified lead titanate ceramics are prepared and studied. The giant electrocaloric effect in lanthanum modified lead titanate ceramics is revealed for the first time. Large refrigeration efficiency (27.4) and high adiabatic temperature change (1.67 K) are achieved by indirect analysis. Direct measurements of electrocaloric effect show that reversible adiabatic temperature change is also about 1.67 K, which exceeds many electrocaloric effect values in current direct measured electrocaloric studies. Both theoretical calculated and direct measured electrocaloric effects are in good agreements in high temperatures. Temperature and electric field related energy storage properties are also analyzed, maximum energy-storage density and energy-storage efficiency are about 0.31 J/cm 3 and 91.2%, respectively.

The Doctoral Degree in Dental Hygiene: Creating New Oral Healthcare Paradigms.

PubMed

Gurenlian, JoAnn R; Rogo, Ellen J; Spolarich, Ann Eshenaur

2016-06-01

Doctoral dental hygiene education would prepare scholars and leaders to improve population health through changes in oral health policy and delivery. Discussions about doctoral education in dental hygiene have centered on the need to create a cadre of dental hygiene researchers and scholars who will expand the body of knowledge for the profession. It has been proposed that scholars are needed to lead the development of theory and disseminate knowledge unique to the discipline of dental hygiene. Transformation to doctoral education is not a new trend as many other health care disciplines have already implemented curricular models, establishing the doctoral degree for entry level into practice. The Institute of Medicine has called for the exploration of new models for care delivery. Dental hygienists need to be prepared with leadership skills enabling them to participate and lead interprofessional teams and develop policies designed to improve the delivery of oral health care services to enhance population health. Current educational models do not adequately prepare dental hygienists to serve in this capacity. The purpose of this article is to present 2 models of doctoral education for dental hygiene that will illustrate how dental hygienists can be better prepared as scholars and leaders for the profession. These proposed models of doctoral education in dental hygiene present a paradigm shift in dental hygiene education. As with other disciplines that have evolved, both academically and professionally, dental hygiene will be positioned to achieve the hallmark of professional status with this terminal degree. Copyright © 2016 Elsevier Inc. All rights reserved.

FY 1987 current fiscal year work plan

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

Not Available

This Current Year Work Plan presents a detailed description of the activities to be performed by the Joint Integration Office during FY87. It breaks down the activities into two major work areas: Program Management and Program Analysis. Program Management is performed by the JIO by providing technical planning and guidance for the development of advanced TRU waste management capabilities. This includes equipment/facility design, engineering, construction, and operations. These functions are integrated to allow transition from interim storage to final disposition. JIO tasks include program requirements identification, long-range technical planning, budget development, program planning document preparation, task guidance, task monitoring, informationmore » gathering and task reporting to DOE, interfacing with other agencies and DOE lead programs, integrating public involvement with program efforts, and preparation of program status reports for DOE. Program Analysis is performed by the JIO to support identification and assessment of alternatives, and development of long-term TRU waste program capabilities. This work plan includes: system analyses, requirements analyses, interim and procedure development, legislative and regulatory analyses, dispatch and traffic analyses, and data bases.« less

From Kratom to mitragynine and its derivatives: physiological and behavioural effects related to use, abuse, and addiction.

PubMed

Hassan, Zurina; Muzaimi, Mustapha; Navaratnam, Visweswaran; Yusoff, Nurul H M; Suhaimi, Farah W; Vadivelu, Rajakumar; Vicknasingam, Balasingam K; Amato, Davide; von Hörsten, Stephan; Ismail, Nurul I W; Jayabalan, Nanthini; Hazim, Ammar I; Mansor, Sharif M; Müller, Christian P

2013-02-01

Kratom (or Ketum) is a psychoactive plant preparation used in Southeast Asia. It is derived from the plant Mitragyna speciosa Korth. Kratom as well as its main alkaloid, mitragynine, currently spreads around the world. Thus, addiction potential and adverse health consequences are becoming an important issue for health authorities. Here we reviewed the available evidence and identified future research needs. It was found that mitragynine and M. speciosa preparations are systematically consumed with rather well defined instrumentalization goals, e.g. to enhance tolerance for hard work or as a substitute in the self-treatment of opiate addiction. There is also evidence from experimental animal models supporting analgesic, muscle relaxant, anti-inflammatory as well as strong anorectic effects. In humans, regular consumption may escalate, lead to tolerance and may yield aversive withdrawal effects. Mitragynine and its derivatives actions in the central nervous system involve μ-opioid receptors, neuronal Ca²⁺ channels and descending monoaminergic projections. Altogether, available data currently suggest both, a therapeutic as well as an abuse potential. Copyright © 2012 Elsevier Ltd. All rights reserved.

Synthesis, characterization and histopathological study of a lead-based Indian traditional drug: naga bhasma.

PubMed

Singh, S K; Gautam, D N S; Kumar, M; Rai, S B

2010-01-01

The aim of the present study is to prepare and characterize Naga bhasma on structural and elemental basis to address the role of the raw materials used during the preparation, compound form of the lead bhasma, nature (crystalline/amorphous) and crystallite/particle size of the drug. The study also covers the toxicological effect of the drug on albino rats. It was found that drug contains lead in nano-crystalline (~60 nm) lead sulfide form (Pb(2+)) associated with the organic contents and different nutrient elements coming from the herbs used during the preparation. Naga bhasma prepared was found to be totally safe in histopathology study on rats at a dose of 6 mg/100 g/day. The different characterization techniques used present a role model for the quality control and standardization of such kinds of herbo-metallic medicines.

LaAlO{sub 3}/Si capacitors: Comparison of different molecular beam deposition conditions and their impact on electrical properties

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

Pelloquin, Sylvain; Baboux, Nicolas; Albertini, David

2013-01-21

A study of the structural and electrical properties of amorphous LaAlO{sub 3} (LAO)/Si thin films fabricated by molecular beam deposition (MBD) is presented. Two substrate preparation procedures have been explored namely a high temperature substrate preparation technique-leading to a step and terraces surface morphology-and a chemical HF-based surface cleaning. The LAO deposition conditions were improved by introducing atomic plasma-prepared oxygen instead of classical molecular O{sub 2} in the chamber. An Au/Ni stack was used as the top electrode for its electrical characteristics. The physico-chemical properties (surface topography, thickness homogeneity, LAO/Si interface quality) and electrical performance (capacitance and current versus voltagemore » and TunA current topography) of the samples were systematically evaluated. Deposition conditions (substrate temperature of 550 Degree-Sign C, oxygen partial pressure settled at 10{sup -6} Torr, and 550 W of power applied to the O{sub 2} plasma) and post-depositions treatments were investigated to optimize the dielectric constant ({kappa}) and leakage currents density (J{sub Gate} at Double-Vertical-Line V{sub Gate} Double-Vertical-Line = Double-Vertical-Line V{sub FB}- 1 Double-Vertical-Line ). In the best reproducible conditions, we obtained a LAO/Si layer with a dielectric constant of 16, an equivalent oxide thickness of 8.7 A, and J{sub Gate} Almost-Equal-To 10{sup -2}A/cm{sup 2}. This confirms the importance of LaAlO{sub 3} as an alternative high-{kappa} for ITRS sub-22 nm technology node.« less

Pin-Hole Free Perovskite Film for Solar Cells Application Prepared by Controlled Two-Step Spin-Coating Method

NASA Astrophysics Data System (ADS)

Bahtiar, A.; Rahmanita, S.; Inayatie, Y. D.

2017-05-01

Morphology of perovskite film is a key important for achieving high performance perovskite solar cells. Perovskite films are commonly prepared by two-step spin-coating method. However, pin-holes are frequently formed in perovskite films due to incomplete conversion of lead-iodide (PbI2) into perovskite CH3NH3PbI3. Pin-holes in perovskite film cause large hysteresis in current-voltage curve of solar cells due to large series resistance between perovskite layer-hole transport material. Moreover, crystal structure and grain size of perovskite crystal are also other important parameters for achieving high performance solar cells, which are significantly affected by preparation of perovskite film. We studied the effect of preparation of perovskite film using controlled spin-coating parameters on crystal structure and morphological properties of perovskite film. We used two-step spin-coating method for preparation of perovskite film with varied spinning speed, spinning time and temperature of spin-coating process to control growth of perovskite crystal aimed to produce high quality perovskite crystal with pin-hole free and large grain size. All experiment was performed in air with high humidity (larger than 80%). The best crystal structure, pin-hole free with large grain crystal size of perovskite film was obtained from film prepared at room temperature with spinning speed 1000 rpm for 20 seconds and annealed at 100°C for 300 seconds.

Being Prepared to Lead: The Management Preparation of Academic Leaders from a Private Career College

ERIC Educational Resources Information Center

Freeman, Abby L.

2011-01-01

The purpose of this research was to determine whether academic leaders from a private career college are prepared to lead. The objective was to determine if leaders in a private career college felt they have the skills necessary to fulfill the needs of the students, faculty, employment sector, and public. This research study is a replication of a…

Patient Selection and Procedural Considerations for Coronary Orbital Atherectomy System

PubMed Central

Sotomi, Yohei; Shlofmitz, Richard A; Colombo, Antonio; Serruys, Patrick W

2016-01-01

Despite advances in technology, percutaneous coronary intervention (PCI) of severely calcified coronary lesions remains challenging. Rotational atherectomy is one of the current therapeutic options to manage calcified lesions, but has a limited role in facilitating the dilation or stenting of lesions that cannot be crossed or expanded with other PCI techniques due to unfavourable clinical outcome in long-term follow-up. However the results of orbital atherectomy presented in the ORBIT I and ORBIT II trials were encouraging. In addition to these encouraging data, necessity for sufficient lesion preparation before implantation of bioresorbable scaffolds lead to resurgence in the use of atherectomy. This article summarises currently available publications on orbital atherectomy (Cardiovascular Systems Inc.) and compares them with rotational atherectomy. PMID:29588702

Funding research in the twenty-first century: current opinions and future directions.

PubMed

Squitieri, Lee; Chung, Kevin C

2014-08-01

For all academic biomedical researchers, the process of submitting grants and securing research funding is a critical part of advancing one's career. In the current era of decreasing new grant awards and renewals leading to significantly worse success rates, it is hard for young aspiring physician-scientists to remain optimistic regarding their future in academic medicine. It is important that today's young surgeon-scientists prepare for and adapt to the inevitably changing climate of research funding. This article provides a primer on developing a successful career as a funded surgeon-scientist and pathways for building a robust research platform worthy of extramural National Institutes of Health funding in the twenty-first century. Copyright © 2014 Elsevier Inc. All rights reserved.

Convective polymer assembly for the deposition of nanostructures and polymer thin films on immobilized particles.

PubMed

Richardson, Joseph J; Björnmalm, Mattias; Gunawan, Sylvia T; Guo, Junling; Liang, Kang; Tardy, Blaise; Sekiguchi, Shota; Noi, Ka Fung; Cui, Jiwei; Ejima, Hirotaka; Caruso, Frank

2014-11-21

We report the preparation of polymer particles via convective polymer assembly (CPA). Convection is used to move polymer solutions and cargo through an agarose gel that contains immobilized template particles. This method both coats and washes the particles in a process that is amenable to automation, and does not depend on passive diffusion or electrical currents, thus facilitating incorporation of fragile and nanoscale objects, such as liposomes and gold nanoparticles, into the thin polymer films. Template dissolution leads to the formation of stable polymer particles and capsules.

DSCOVR Spacecraft Arrival, Offload, & Unpacking

NASA Image and Video Library

2014-11-20

Preparations are underway to remove a protective shipping container from around NOAA’s Deep Space Climate Observatory spacecraft, or DSCOVR, at the Astrotech payload processing facility in Titusville, Florida, near Kennedy Space Center. DSCOVR is a partnership between NOAA, NASA and the U.S. Air Force. DSCOVR will maintain the nation's real-time solar wind monitoring capabilities which are critical to the accuracy and lead time of NOAA's space weather alerts and forecasts. Launch is currently scheduled for January 2015 aboard a SpaceX Falcon 9 v 1.1 launch vehicle from Cape Canaveral Air Force Station, Florida.

Recycling isotachophoresis - A novel approach to preparative protein fractionation

NASA Technical Reports Server (NTRS)

Sloan, Jeffrey E.; Thormann, Wolfgang; Bier, Milan; Twitty, Garland E.; Mosher, Richard A.

1986-01-01

The concept of automated recycling isotachophoresis (RITP) as a purification methodology is discussed, in addition to a description of the apparatus. In the present automated RITP, the computer system follows the achievement of steady state using arrays of universal and specific sensors, monitors the position of the front edge of the zone structure, activates the counterflow if the leading boundary passes a specified position along the separation axis, or changes the applied current, accordingly. The system demonstrates high resolution, in addition to higher processing rates than are possible in zone electrophoresis or isoelectric focusing.

Experiments and scaling laws for catastrophic collisions. [of asteroids

NASA Technical Reports Server (NTRS)

Fujiwara, A.; Cerroni, P.; Davis, D.; Ryan, E.; Di Martino, M.

1989-01-01

The existing data on shattering impacts are reviewed using natural silicate, ice, and cement-mortar targets. A comprehensive data base containing the most important parameters describing these experiments was prepared. The collisional energy needed to shatter consolidated homogeneous targets and the ensuing fragment size distributions have been well studied experimentally. However, major gaps exist in the data on fragment velocity and rotational distributions, as well as collisional energy partitioning for these targets. Current scaling laws lead to predicted outcomes of asteroid collisions that are inconsistent with interpretations of astronomical data.

Integrated circuit package with lead structure and method of preparing the same

NASA Technical Reports Server (NTRS)

Kennedy, B. W. (Inventor)

1973-01-01

A beam-lead integrated circuit package assembly including a beam-lead integrated circuit chip, a lead frame array bonded to projecting fingers of the chip, a rubber potting compound disposed around the chip, and an encapsulating molded plastic is described. The lead frame array is prepared by photographically printing a lead pattern on a base metal sheet, selectively etching to remove metal between leads, and plating with gold. Joining of the chip to the lead frame array is carried out by thermocompression bonding of mating goldplated surfaces. A small amount of silicone rubber is then applied to cover the chip and bonded joints, and the package is encapsulated with epoxy resin, applied by molding.

Thin film transistor performance of amorphous indium–zinc oxide semiconductor thin film prepared by ultraviolet photoassisted sol–gel processing

NASA Astrophysics Data System (ADS)

Kodzasa, Takehito; Nobeshima, Taiki; Kuribara, Kazunori; Yoshida, Manabu

2018-05-01

We have fabricated an amorphous indium–zinc oxide (IZO, In/Zn = 3/1) semiconductor thin-film transistor (AOS-TFT) by the sol–gel technique using ultraviolet (UV) photoirradiation and post-treatment in high-pressure O2 at 200 °C. The obtained TFT showed a hole carrier mobility of 0.02 cm2 V‑1 s‑1 and an on/off current ratio of 106. UV photoirradiation leads to the decomposition of the organic agents and hydroxide group in the IZO gel film. Furthermore, the post-treatment annealing at a high O2 pressure of more than 0.6 MPa leads to the filling of the oxygen vacancies in a poor metal–oxygen network in the IZO film.

Hydrogenated TiO2 Thin Film for Accelerating Electron Transport in Highly Efficient Planar Perovskite Solar Cells.

PubMed

Yao, Xin; Liang, Junhui; Li, Yuelong; Luo, Jingshan; Shi, Biao; Wei, Changchun; Zhang, Dekun; Li, Baozhang; Ding, Yi; Zhao, Ying; Zhang, Xiaodan

2017-10-01

Intensive studies on low-temperature deposited electron transport materials have been performed to improve the efficiency of n-i-p type planar perovskite solar cells to extend their application on plastic and multijunction device architectures. Here, a TiO 2 film with enhanced conductivity and tailored band edge is prepared by magnetron sputtering at room temperature by hydrogen doping (HTO), which accelerates the electron extraction from perovskite photoabsorber and reduces charge transfer resistance, resulting in an improved short circuit current density and fill factor. The HTO film with upward shifted Fermi level guarantees a smaller loss on V OC and facilitates the growth of high-quality absorber with much larger grains and more uniform size, leading to devices with negligible hysteresis. In comparison with the pristine TiO 2 prepared without hydrogen doping, the HTO-based device exhibits a substantial performance enhancement leading to an efficiency of 19.30% and more stabilized photovoltaic performance maintaining 93% of its initial value after 300 min continuous illumination in the glove box. These properties permit the room-temperature magnetron sputtered HTO film as a promising electron transport material for flexible and tandem perovskite solar cell in the future.

[Estimation of maximum acceptable concentration of lead and cadmium in plants and their medicinal preparations].

PubMed

Zitkevicius, Virgilijus; Savickiene, Nijole; Abdrachmanovas, Olegas; Ryselis, Stanislovas; Masteiková, Rūta; Chalupova, Zuzana; Dagilyte, Audrone; Baranauskas, Algirdas

2003-01-01

Heavy metals (lead, cadmium) are possible dashes which quantity is defined by the limiting acceptable contents. Different drugs preparations: infusions, decoctions, tinctures, extracts, etc. are produced using medicinal plants. The objective of this research was to study the impurities of heavy metals (lead, cadmium) in medicinal plants and some drug preparations. We investigated liquid extracts of fruits Crataegus monogyna Jacq. and herbs of Echinacea purpurea Moench., tinctures--of herbs Leonurus cardiaca L. The raw materials were imported from Poland. Investigations were carried out in cooperation with the Laboratory of Antropogenic Factors of the Institute for Biomedical Research. Amounts of lead and cadmium were established after "dry" mineralisation using "Perkin-Elmer Zeeman/3030" model electrothermic atomic absorption spectrophotometer (ETG AAS/Zeeman). It was established that lead is absorbed most efficiently after estimation of absorption capacity of cellular fibers. About 10.73% of lead crosses tinctures and extracts, better cadmium--49.63%. Herbs of Leonurus cardiaca L. are the best in holding back lead and cadmium. About 14.5% of lead and cadmium crosses the tincture of herbs Leonurus cardiaca L. We estimated the factors of heavy metals (lead, cadmium) in the liquid extracts of Crataegus monogyna Jacq. and Echinacea purpurea Moench., tincture of Leonurus cardiaca L. after investigations of heavy metals (lead, cadmium) in drugs and preparations of it. The amounts of heavy metals (lead, cadmium) don't exceed the allowable norms in fruits of Crataegus monogyna Jacq., herbs of Leonurus cardiaca L. and Echinacea purpurea Moench. after estimation of lead and cadmium extraction factors, the maximum of acceptable daily intake and the quantity of drugs consumption in day.

Composite-Nanoparticles Thermal History Sensors

DTIC Science & Technology

2014-05-01

al. Lead Telluride and Selenide Nanostructures Under Different Hydrothermal Synthesis Conditions Fig. 5. SEM image of PbTe solid nano- and micro-cubes...Lead Telluride and Selenide Nanostructures Under Different Hydrothermal Synthesis Conditions For the preparation of PbSe microflowers, a similar pro...R C H A R TIC LE Poudel et al. Lead Telluride and Selenide Nanostructures Under Different Hydrothermal Synthesis Conditions For the preparation of

High-efficiency perovskite solar cells prepared by using a sandwich structure MAI-PbI2-MAI precursor film.

PubMed

Zhang, Xuhui; Ye, Jiajiu; Zhu, Liangzheng; Zheng, Haiying; Liu, Guozhen; Liu, Xuepeng; Duan, Bin; Pan, Xu; Dai, Songyuan

2017-04-06

Two-step deposition has been widely used in the perovskite layer preparation for perovskite solar cells due to its attractive morphology controllability. However, the limited diffusivity of CH 3 NH 3 I (MAI) might cause some PbI 2 to remain in the perovskite film. The residual PbI 2 in the perovskite film would lead to inferior performance of devices, such as, low power conversion efficiency (PCE), poor reproducibility and weak air stability. In this work, we developed a sandwich structure MAI-PbI 2 -MAI precursor film to prepare a PbI 2 -free CH 3 NH 3 PbI 3 perovskite film. In comparison to the two-step approach, the MAI-PbI 2 -MAI precursor film with a typical sandwich structure formed a uniform and pinhole-free perovskite film without any PbI 2 residue, which could significantly improve the performance of the devices. Moreover, the bottom MAI layer of the MAI-PbI 2 -MAI precursor film could improve the interfacial contact of the porous TiO 2 layer, leading to the promotion of the charge transfer and reduction of the recombination rate. Therefore, the devices fabricated from the sandwich structure MAI-PbI 2 -MAI precursor films showed dramatic improvements of open-circuit voltage (V oc ), short-circuit current density (J sc ), fill factor (FF) and PCE. As a result, a promising PCE of 17.8% with good long-term air stability was achieved for the MAI-PbI 2 -MAI precursor film based PSC, which is better than that prepared by a two-step approach.

Interconnecting Carbon Fibers with the In-situ Electrochemically Exfoliated Graphene as Advanced Binder-free Electrode Materials for Flexible Supercapacitor.

PubMed

Zou, Yuqin; Wang, Shuangyin

2015-07-07

Flexible energy storage devices are highly demanded for various applications. Carbon cloth (CC) woven by carbon fibers (CFs) is typically used as electrode or current collector for flexible devices. The low surface area of CC and the presence of big gaps (ca. micro-size) between individual CFs lead to poor performance. Herein, we interconnect individual CFs through the in-situ exfoliated graphene with high surface area by the electrochemical intercalation method. The interconnected CFs are used as both current collector and electrode materials for flexible supercapacitors, in which the in-situ exfoliated graphene act as active materials and conductive "binders". The in-situ electrochemical intercalation technique ensures the low contact resistance between electrode (graphene) and current collector (carbon cloth) with enhanced conductivity. The as-prepared electrode materials show significantly improved performance for flexible supercapacitors.

The Effectiveness of LEAD Program Elements.

ERIC Educational Resources Information Center

Carver, Fred D.

This paper describes the Leadership Enhancement and Development (LEAD) preparation program implemented in Gwinnett County School District, Georgia, and designed to prepare participants for assistant principalships in the school district. Those selected for the program completed year-long coursework and a 12-week internship. This report presents…

Non-aqueous electrochemical deposition of lead zirconate titanate films for flexible sensor applications

NASA Astrophysics Data System (ADS)

Joseph, Sherin; Kumar, A. V. Ramesh; John, Reji

2017-11-01

Lead zirconate titanate (PZT) is one of the most important piezoelectric materials widely used for underwater sensors. However, PZTs are hard and non-compliant and hence there is an overwhelming attention devoted toward making it flexible by preparing films on flexible substrates by different routes. In this work, the electrochemical deposition of composition controlled PZT films over flexible stainless steel (SS) foil substrates using non-aqueous electrolyte dimethyl sulphoxide (DMSO) was carried out. Effects of various key parameters involved in electrochemical deposition process such as current density and time of deposition were studied. It was found that a current density of 25 mA/cm2 for 5 min gave a good film. The morphology and topography evaluation of the films was carried out by scanning electron microscopy (SEM) and atomic force microscopy (AFM), respectively, which showed a uniform morphology with a surface roughness of 2 nm. The PZT phase formation was studied using X-ray diffraction (XRD) and corroborated with Raman spectroscopic studies. The dielectric constant, dielectric loss, hysteresis and I-V characteristics of the film was evaluated.

Chemistry and Spectroscopy of Frozen Chloride Salts on Icy Bodies

NASA Astrophysics Data System (ADS)

Johnson, P. V.; Thomas, E. C.; Hodyss, R. P.; Vu, T. H.; Choukroun, M.

2016-12-01

Understanding the habitability of Europa's ocean is of great interest to astrobiology and is the focus of missions currently being considered to explore Europa. Currently, our best means of constraining the subsurface ocean composition and its subsequent habitability is by further study of Europa's surface chemical composition. Analysis of existing (and future) remote sensing data is limited by the availability of spectral libraries of candidate materials under relevant conditions (temperature, thermal/radiation history, etc.). Geochemical predictions of Europa's ocean composition suggest that chloride salts are likely to exist on the surface of Europa as well as other ocean worlds. We have conducted a study of frozen chloride-salt brines prepared at temperatures, pressures and radiation conditions (UV) in order to simulate conditions on the surface of Europa and other airless bodies. Hydration states of various chloride salts as a function of temperature were determined using Raman spectroscopy. Near IR reflectance spectra of identically prepared samples were measured to provide reference spectra of the identified hydrated salts. We find that the freezing of NaCl at temperatures ranging from 80 K to 233 K forms hydrohalite. In contrast, KCl hydrates are not formed from the freezing of KCl brines. In addition, a stable hexahydrate forms from the freezing of MgCl2 solutions, while a hexahydrate, a tetrahydrate, and a dihydrate, form upon freezing of CaCl2 solutions. Salts were observed to dehydrated with increasing temperatures, leading to a succession of hydration states in the case of CaCl2. Irradiation with vacuum ultraviolet light was observed to lead to dehydration as well.

Stabilization of high Tc phase in bismuth cuprate superconductor by lead doping

NASA Technical Reports Server (NTRS)

Gupta, Ram. P.; Pachauri, J. P.; Khokle, W. S.; Nagpal, K. C.; Date, S. K.

1991-01-01

It has been widely ascertained that doping of lead in Bi-Sr-Ca-Cu-O systems promotes the growth of high T sub c (110 K) phase, improves critical current density, and lowers processing temperature. A systematic study was undertaken to determine optimum lead content and processing conditions to achieve these properties. A large number of samples with cationic compositions of Bi(2-x)Pb(x)Sr2Ca2Cu3 (x = 0.2 to 2.0) were prepared by conventional solid state reaction technique. Samples of all compositions were annealed together at a temperature and characterized through resistance temperature (R-T) measurements and x ray diffraction to determine the zero resistance temperature, T sub c(0) and to identify presence of phases, respectively. The annealing temperature was varied between 790 and 880 C to optimize processing parameters. Results are given. In brief, an optimum process is reported along with composition of leaded bismuth cuprate superconductor which yields nearly a high T sub c single phase with highly stable superconducting properties.

Stabilization of high T(sub c) phase in bismuth cuprate superconductor by lead doping

NASA Technical Reports Server (NTRS)

Gupta, Ram. P.; Pachauri, J. P.; Khokle, W. S.; Nagpal, K. C.; Date, S. K.

1990-01-01

It has widely been ascertained that doping of lead in Bi:Sr:Ca:Cu:O systems promotes the growth of high T(sub c) (110 K) phase, improves critical current density, and lowers processing temperature. A systematic investigation is undertaken to determine optimum lead content and processing conditions to achieve these. A large number of samples with cationic compositions of Bi(2-x)Pb(x)Sr2Ca2Cu3 (x = 0.2 to 2.0) were prepared by conventional solid state reaction technique. Samples of all compositions were annealed together at a temperature and characterized through resistance-temperature (R-T) measurements and x ray diffraction (XRD) to determine the zero resistance temperature, T(sub c)(0) and to identify presence of phases, respectively. The annealing temperature was varied between 790 C to optimize processing parameters. Results are given. In brief, an optimum process is reported along with composition of leaded bismuth cuprate superconductor which yields nearly a high T(sub c) single phase with highly stable superconducting properties.

The Prevention of Surgical Site Infection in Elective Colon Surgery

PubMed Central

Fry, Donald E.

2013-01-01

Infections at the surgical site continue to occur in as many as 20% of elective colon resection cases. Methods to reduce these infections are inconsistently applied. Surgical site infection (SSI) is the result of multiple interactive variables including the inoculum of bacteria that contaminate the site, the virulence of the contaminating microbes, and the local environment at the surgical site. These variables that promote infection are potentially offset by the effectiveness of the host defense. Reduction in the inoculum of bacteria is achieved by appropriate surgical site preparation, systemic preventive antibiotics, and use of mechanical bowel preparation in conjunction with the oral antibiotic bowel preparation. Intraoperative reduction of hematoma, necrotic tissue, foreign bodies, and tissue dead space will reduce infections. Enhancement of the host may be achieved by perioperative supplemental oxygenation, maintenance of normothermia, and glycemic control. These methods require additional research to identify optimum application. Uniform application of currently understood methods and continued research into new methods to reduce microbial contamination and enhancement of host responsiveness can lead to better outcomes. PMID:24455434

Recent progress on RE2O3-Mo/W emission materials.

PubMed

Wang, Jinshu; Zhang, Xizhu; Liu, Wei; Cui, Yuntao; Wang, Yiman; Zhou, Meiling

2012-08-01

RE2O3-Mo/W cathodes were prepared by powder metallurgy method. La2O3-Y2O3-Mo cermet cathodes prepared by traditional sintering method and spark plasma sintering (SPS) exhibit different secondary emission properties. The La2O3-Y2O3-Mo cermet cathode prepared by SPS method has smaller grain size and exhibits better secondary emission performance. Monte carlo calculation results indicate that the secondary electron emission way of the cathode correlates with the grain size. Decreasing the grain size can decrease the positive charging effect of RE2O3 and thus is favorable for the escaping of secondary electrons to vacuum. The Scandia doped tungsten matrix dispenser cathode with a sub-micrometer microstructure of matrix with uniformly distributed nanometer-particles of Scandia has good thermionic emission property. Over 100 A/cm2 full space charge limited current density can be obtained at 950Cb. The cathode surface is covered by a Ba-Sc-O active surface layer with nano-particles distributing mainly on growth steps of W grains, leads to the conspicuous emission property of the cathode.

Pharmacological differences and clinical implications of various botulinum toxin preparations: a critical appraisal

PubMed Central

Ferrari, Adriano; Manca, Mario; Tugnoli, Valeria

2018-01-01

Summary Three different type A botulinum neurotoxins (BoNTAs) — onabotulinumtoxinA, abobotulinumtoxinA and incobotulinumtoxinA) — are currently marketed in Europe to treat several conditions. Differences between BoNTA preparations, which depend on their specific biotypes and manufacturing processes, lead to clinically relevant pharmacotherapeutic dissimilarities. All three available products are separately recognized and reviewed in American Academy of Neurology guidelines. The neurotoxin load/100U is likewise different among the different BoNTAs, with the result that the specific potency of the 150kD BoNTA neurotoxin is calculated as 137 units/ng for onabotulinumtoxinA, 154 units/ng for abobotulinumtoxinA, and 227 units/ng for incobotulinumtoxinA. It is important for clinicians to have all three BoNTAs available in order to choose the most suitable preparation for the specific indication in the single patient. Commercially available BoNTAs must be recognized as different from one another, and therefore as non-interchangeable. The essential experience of the clinician is of the utmost importance in choosing the most appropriate treatment. PMID:29633692

Effects of Thickness, Pulse Duration, and Size of Strip Electrode on Ferroelectric Electron Emission of Lead Zirconate Titanate Films

NASA Astrophysics Data System (ADS)

Yaseen, Muhammad; Ren, Wei; Chen, Xiaofeng; Feng, Yujun; Shi, Peng; Wu, Xiaoqing

2018-02-01

Sol-gel-derived lead zirconate titanate (PZT) thin-film emitters with thickness up to 9.8 μm have been prepared on Pt/TiO2/SiO2/Si wafer via chemical solution deposition with/without polyvinylpyrrolidone (PVP) modification, and the relationship between the film thickness and electron emission investigated. Notable electron emission was observed on application of a trigger voltage of 120 V for PZT film with thickness of 1.1 μm. Increasing the film thickness decreased the threshold field to initiate electron emission for non-PVP-modified films. In contrast, the electron emission behavior of PVP-modified films did not show significant dependence on film thickness, probably due to their porous structure. The emission current increased with decreasing strip width and space between strips. Furthermore, it was observed that increasing the duration of the applied pulse increased the magnitude of the emission current. The stray field on the PZT film thickness was also calculated and found to increase with increasing ferroelectric sample thickness. The PZT emitters were found to be fatigue free up to 105 emission cycles. Saturated emission current of around 25 mA to 30 mA was achieved for the electrode pattern used in this work.

The aging work force in Korea.

PubMed

Hong, Jungyeon; Lee, Kangsook

2012-04-01

Korea has the fastest aging population and least fertile population of all Organization Economic Cooperation and Development countries, and it is undertaking significant preparations for an aging society. So, we want to review the present status of Elderly workers' occupational disorders and preparations, which is performed by governmental, social parties. We examine the current status of Korea's aging work force, focusing on occupational disorders (injuries and diseases), and retirements, and the associated health effects. Despite the efforts and concern about Korea's aging society since the issue was first identified, Korea's limited experience in operating a national public pension system, and a mature social security system shows that the needs of Korea's aging society cannot be fully satisfied. This problem has already resulted in increasing labor employment rates and delays in retirement from the labor market. We suggest a policy for elderly workers considering various determinants that can lead to successful employment, retirement, and health promotion for the aging work force.

Long acting injectable hormonal contraceptives.

PubMed

Fraser, I S

1982-03-01

Injectable hormonal preparations can be highly effective and satisfactory contraceptives. The two main preparations available today are depot medroxy progesterone acetate (DMPA) and norethisterone oenanthate (NET-OEN), but several other approaches are currently under clinical trial. Injectable contraceptives have some unique advantages which give them justifiably wide appeal amongst many groups of women. However, they do have a number of disadvantages including invariable menstrual disturbance and a delay in the return of fertility. One formulation of DMPA, Depo-Provera, is probably the most extensively investigated single hormonal contraceptive ever made. These studies indicate that it is remarkably safe and does not face any more unresolved issues than the combined pill, intrauterine device or tubal sterilization. However, for a number of disparate emotional and political reasons it has attracted the attention of several consumer and feminist groups, who have waged a prolonged and quite unjustified campaign against it. It is to be hoped that future debate will be conducted on a more informed, rational and less emotional basis. Injectable contraceptives should have an important place in the family planning armamentarium of all countries, and current developments should lead to a decrease in concerns about presently available agents. This should further increase the widespread acceptability of this approach to contraception.

Enhancing Earth Science And IT Literacy Through Environmental Science Information Technology Activities

NASA Astrophysics Data System (ADS)

Cuff, K. E.; Molinaro, M.

2004-12-01

The Environmental Science Information Technology Activities (ESITA) program provides grades 9 and 10 students with under-represented minority backgrounds in the East San Francisco Bay Area with real-world opportunities to learn about and apply information technologies through a series of project-based activities related to environmental science. Supported by the NSF Information Technology Experiences for Students and Teachers (ITEST) program, ESITA activities engage students in the use of newly acquired information technology (IT) skills and understandings while performing air and water quality research investigations. One project that ESITA students have become involved in relates to the currently relevant issue of elevated levels of lead found in drinking waters in Washington, D.C. Students based in the Bay Area have initiated and maintained E-mail correspondence with children who attend elementary schools in the D.C. area. After receiving a thorough explanation of required sampling procedures devised by the Bay Area students, the elementary school children have sent 500 ml water samples from their homes and schools to Berkeley along with information about the locations from which the water samples were collected. These samples were then prepared for lead analysis at Lawrence Hall of Science by ESITA students, who used resulting data to perform a preliminary assessment of the geospatial distribution of lead trouble spots throughout Washington, DC. Later, ESITA student scientists will work with students from the UC Berkeley School of Public Health to develop surveys and questionnaires that generate high quality information useful with regard to assessing the impact of the current lead crisis on younger children in the Washington, D.C. area. Through the application of new understandings to current, real-world environmental problems and issues such as that related to lead, positive changes in students' attitudes towards IT and science have occurred, which accompany increases in their content learning and skills acquisition abilities.

[Patients are not prepared to choose: another example of a failing market?].

PubMed

Levi, Marcel; Bos, Wouter

2015-01-01

The Netherlands has a demand-driven health care system based on market mechanisms. However, the system is a hybrid between two potential situations: one in which healthcare insurance companies have a leading role, with consumers and patients choosing for the company that most suits them, and one in which patients have a leading role and select their favourite caregiver, whereby the insurance company has to follow. Current research concludes that the vast majority of patients are not able or even willing to choose, but instead place their trust in referring physicians and local hospitals. Additionally, many patients feel that they are not capable of making informed choices. If patients cannot or do not want to choose their healthcare providers, then one of the mainstays of a market-based health care system should perhaps be seriously re-evaluated.

Interpretation of standard leaching test BS EN 12457-2: is your sample hazardous or inert?

PubMed

Zandi, Mohammad; Russell, Nigel V; Edyvean, Robert G J; Hand, Russell J; Ward, Philip

2007-12-01

A slag sample from a lead refiner has been obtained and given to two analytical laboratories to determine the release of trace elements from the sample according to BS EN 12457-2. Samples analysed by one laboratory passed waste acceptance criteria, leading it to be classified as an inert material; samples of the same material analysed by the other laboratory failed waste acceptance criteria and were classified as hazardous. It was found that the sample preparation procedure is the critical step in the leaching analysis and that the effects of particle size on leachability should be taken into account when using this standard. The purpose of this paper is to open a debate on designing a better defined standard leaching test and making current waste acceptance criteria more flexible.

Lead contamination in Eugenia dyeriana herbal preparations from different commercial sources in Malaysia.

PubMed

Ang, H H

2008-06-01

The Drug Control Authority (DCA) of Malaysia implemented the phase three registration of traditional medicines on 1 January, 1992. A total of 100 products in various pharmaceutical dosage forms of a herbal preparation, containing Eugenia dyeriana, either single or combined preparations (more than one medicinal plant), were analyzed for the presence of lead contamination, using atomic absorption spectrophotometry. These samples were bought from different commercial sources in the Malaysian market, after performing a simple random sampling. Results showed that 22% of the above products failed to comply with the quality requirement for traditional medicines in Malaysia. Although this study showed that 78% of the products fully complied with the quality requirement for traditional medicines in Malaysia pertaining to lead, however, they cannot be assumed safe from lead contamination because of batch-to-batch inconsistency.

Improvement of Intestinal Absorption of Forsythoside A and Chlorogenic Acid by Different Carboxymethyl Chitosan and Chito-oligosaccharide, Application to Flos Lonicerae - Fructus Forsythiae Herb Couple Preparations

PubMed Central

Zhou, Wei; Wang, Haidan; Zhu, Xuanxuan; Shan, Jinjun; Yin, Ailing; Cai, Baochang; Di, Liuqing

2013-01-01

The current study aims to investigate the effect of chitosan derivatives on the intestinal absorption and bioavailabilities of forsythoside A (FTA) and Chlorogenic acid (CHA), the major active components in Flos Lonicerae - Fructus Forsythiae herb couple. Biopharmaceutics and pharmacokinetics properties of the two compounds have been characterized in vitro, in situ as well as in rats. Based on the identified biopharmaceutics characteristics of the two compounds, the effect of chitosan derivatives as an absorption enhancer on the intestinal absorption and pharmacokinetics of FTA and CHA in pure compound form as well as extract form were investigated in vitro, in situ and in vivo. Both FTA and CHA demonstrated very limited intestinal permeabilities, leading to oral bioavailabilities being only 0.50% and 0.13% in rats, respectively. Results from both in vitro, in situ as well as in vivo studies consistently indicated that Chito-oligosaccharide (COS) at dosage of 25 mg/kg could enhance intestinal permeabilities significantly as well as the in vivo bioavailabilities of both FTA and CHA than CMCs in Flos Lonicerae - Fructus Forsythiae herb couple preparations, and was safe for gastrointestine from morphological observation. Besides, treatment with Flos Lonicerae - Fructus Forsythiae herb couple preparations with COS at the dosage of 25 mg/kg prevented MDCK damage after influenza virus propagation, which was significantly better than control. The current findings not only identified the usefulness of COS for the improved delivery of Flos Lonicerae - Fructus Forsythiae preparations but also demonstrated the importance of biopharmaceutical characterization in the dosage form development of traditional Chinese medicine. PMID:23675483

DSCOVR Spacecraft Arrival, Offload, & Unpacking

NASA Image and Video Library

2014-11-20

Preparations are underway to lift NOAA’s Deep Space Climate Observatory spacecraft, or DSCOVR, wrapped in plastic, from its transportation pallet at the Astrotech payload processing facility in Titusville, Florida, near Kennedy Space Center. DSCOVR is a partnership between NOAA, NASA and the U.S. Air Force. DSCOVR will maintain the nation's real-time solar wind monitoring capabilities which are critical to the accuracy and lead time of NOAA's space weather alerts and forecasts. Launch is currently scheduled for January 2015 aboard a SpaceX Falcon 9 v 1.1 launch vehicle from Cape Canaveral Air Force Station, Florida.

Catalytic, Enantioselective Synthesis of Stilbene cis-Diamines: A Concise Preparation of (–)-Nutlin-3, a Potent p53/MDM2 Inhibitor

PubMed Central

Davis, Tyler A.

2012-01-01

The first highly diastereo- and enantioselective additions of aryl nitromethane pronucleophiles to aryl aldimines are described. Identification of an electron rich chiral Bis(Amidine) catalyst for this aza-Henry variant was key to this development, leading ultimately to differentially protected cis-stilbene diamines in two steps. This method then became the lynchpin for an enantioselective synthesis of (–)-Nutlin-3 (Hoffmann-LaRoche), a potent cis-imidazoline small molecule inhibitor of p53-MDM2 used extensively as a probe of cell biology and currently in drug development. PMID:22708054

Removal of Heavy Metal Ions with Acid Activated Carbons Derived from Oil Palm and Coconut Shells

PubMed Central

Rahman, Mokhlesur M.; Adil, Mohd; Yusof, Alias M.; Kamaruzzaman, Yunus B.; Ansary, Rezaul H.

2014-01-01

In this work, batch adsorption experiments were carried out to investigate the suitability of prepared acid activated carbons in removing heavy metal ions such as nickel(II), lead(II) and chromium(VI). Acid activated carbons were obtained from oil palm and coconut shells using phosphoric acid under similar activation process while the differences lie either in impregnation condition or in both pretreatment and impregnation conditions. Prepared activated carbons were modified by dispersing hydrated iron oxide. The adsorption equilibrium data for nickel(II) and lead(II) were obtained from adsorption by the prepared and commercial activated carbons. Langmuir and Freundlich models fit the data well. Prepared activated carbons showed higher adsorption capacity for nickel(II) and lead(II). The removal of chromium(VI) was studied by the prepared acid activated, modified and commercial activated carbons at different pH. The isotherms studies reveal that the prepared activated carbon performs better in low concentration region while the commercial ones in the high concentration region. Thus, a complete adsorption is expected in low concentration by the prepared activated carbon. The kinetics data for Ni(II), Pb(II) and Cr(VI) by the best selected activated carbon fitted very well to the pseudo-second-order kinetic model. PMID:28788640

Laser Ablation Surface Preparation of Ti-6A1-4V for Adhesive Bonding

NASA Technical Reports Server (NTRS)

Palmieri, Frank L.; Watson, Kent A.; Morales, Guillermo; Williams, Thomas; Hicks, Robert; Wohl, Christopher J.; Hopkins, John W.; Connell, John W.

2012-01-01

Adhesive bonding offers many advantages over mechanical fastening, but requires certification before it can be incorporated in primary structures for commercial aviation without disbond-arrestment features or redundant load paths. Surface preparation is widely recognized as the key step to producing robust and predictable bonds. Laser ablation imparts both topographical and chemical changes to a surface which can lead to increased bond durability. A laser based process provides an alternative to chemical-dip, manual abrasion and grit blast treatments which are expensive, hazardous, polluting, and less precise. This report documents preliminary testing of a surface preparation technique using laser ablation as a replacement for the chemical etch and abrasive processes currently applied to Ti-6Al-4V alloy adherends. Failure mode, surface roughness, and chemical makeup were analyzed using fluorescence enhanced visualization, microscopy, and X-ray photoelectron spectroscopy, respectively. Single lap shear tests were conducted on bonded and aged specimens to observe bond strength retention and failure mode. Some promising results showed increasing strength and durability of lap shear specimens as laser ablation coverage area and beam intensity increased. Chemical analyses showed trends for surface chemical species which correlated with improved bond strength and durability. Combined, these results suggest that laser ablation is a viable process for inclusion with or/and replacement of one or more currently used titanium surface treatments. On-going work will focus on additional mechanical tests to further demonstrate improved bond durability.

Toxics Release Inventory Expansion Rule Phase 3 (TRI-P3)

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

Evans, R.A.; Saunders, A.D.; Worley, G.G.

1998-09-01

The ORR [East Tennessee Technology Park (ETTP), Y-12 Plant, and Oak Ridge National Laboratory (ORNL)] is considered a single facility for reporting by the DOE prime contractors. The processing, manufacturing, or "otherwise use" Section313 chemicals are combined to determine TRI reportability. Such is the case with lead metal, which is one of two chemicals for which reportin~ forms were prepared in this pilot study (Task 2;1. The lead shop at ORNL exceeded the reporting threshold, causing a lead activity at a Y-1 2 machine shop and lead in waste at ETTP to be reportable. TRI-P3 report preparation time for leadmore » totaled 36.5 hours. The second chemical investigated and reported (chromium) also required nearly a man-week for report preparation and documentation by experienced TRI personnel. The ORR TRI report typically includes about six chemicals, so an estimate of the TRI-P3 incremental reporting burden for ORR would be six weeks for experienced personnel axI d two/three man-months for first-time ORR preparers.« less

Oxygen Measurements in Liposome Encapsulated Hemoglobin

NASA Astrophysics Data System (ADS)

Phiri, Joshua Benjamin

Liposome encapsulated hemoglobins (LEH's) are of current interest as blood substitutes. An analytical methodology for rapid non-invasive measurements of oxygen in artificial oxygen carriers is examined. High resolution optical absorption spectra are calculated by means of a one dimensional diffusion approximation. The encapsulated hemoglobin is prepared from fresh defibrinated bovine blood. Liposomes are prepared from hydrogenated soy phosphatidylcholine (HSPC), cholesterol and dicetylphosphate using a bath sonication method. An integrating sphere spectrophotometer is employed for diffuse optics measurements. Data is collected using an automated data acquisition system employing lock-in -amplifiers. The concentrations of hemoglobin derivatives are evaluated from the corresponding extinction coefficients using a numerical technique of singular value decomposition, and verification of the results is done using Monte Carlo simulations. In situ measurements are required for the determination of hemoglobin derivatives because most encapsulation methods invariably lead to the formation of methemoglobin, a nonfunctional form of hemoglobin. The methods employed in this work lead to high resolution absorption spectra of oxyhemoglobin and other derivatives in red blood cells and liposome encapsulated hemoglobin (LEH). The analysis using singular value decomposition method offers a quantitative means of calculating the fractions of oxyhemoglobin and other hemoglobin derivatives in LEH samples. The analytical methods developed in this work will become even more useful when production of LEH as a blood substitute is scaled up to large volumes.

Screen printed Y and Bi-based superconductors

NASA Technical Reports Server (NTRS)

Haertling, Gene H.; Hsi, Chi-Shiung

1992-01-01

High T(sub c) superconducting thick film was prepared by screen printing process. Y-based (YBa2Cu3O(7 - x)) superconducting thick films were printed on 211/Al2O3, SNT/Al2O3, and YSZ substrates. Because of poor adhesion of the superconducting thick films to 211/Al2O3 and SNT/Al2O3 substrates, relatively low T(sub c) and J(sub c) values were obtained from the films printed on these substrates. Critical temperatures of YBa2Cu3O(7 - x) thick films deposited on 211/Al2O3 and SNT/Al2O3 substrates were about 80 K. The critical current densities of these films were less than 2 A/cm(exp 2). Higher T(sub c) and J(sub c) films were printed on the YSZ substrates; T(sub c) = 86.4 K and J(sub c) = 50.4 A/cm(exp 2). Multiple lead samples were also prepared on the YSZ substrates. These showed lower T(sub c) and J(sub c) values than plain samples. The heat treatment conditions of the multiple lead samples are still under investigation. Bi-based superconductor thick films have been obtained so far. Improving the superconducting properties of the BSCCO screen printed thick films will be emphasized in future work.

Design and Solidification of Fast-Releasing Clofazimine Nanoparticles for Treatment of Cryptosporidiosis

PubMed Central

2017-01-01

Clofazimine, a lipophilic (log P = 7.66) riminophenazine antibiotic approved by the US Food and Drug Administration (FDA) with a good safety record, was recently identified as a lead hit for cryptosporidiosis through a high-throughput phenotypic screen. Cryptosporidiosis requires fast-acting treatment as it leads to severe symptoms which, if untreated, result in morbidity for infants and small children. Consequently, a fast-releasing oral formulation of clofazimine in a water-dispersible form for pediatric administration is highly desirable. In this work, clofazimine nanoparticles were prepared with three surface stabilizers, hypromellose acetate succinate (HPMCAS), lecithin, and zein, using the flash nanoprecipitation (FNP) process. Drug encapsulation efficiencies of over 92% were achieved. Lyophilization and spray-drying were applied and optimized to produce redispersible nanoparticle powders. The release kinetics of these clofazimine nanoparticle powders in biorelevant media were measured and compared with those of crystalline clofazimine and the currently marketed formulation Lamprene. Remarkably improved dissolution rates and clofazimine supersaturation levels up to 90 times equilibrium solubility were observed with all clofazimine nanoparticles tested. Differential scanning calorimetry indicated a reduction of crystallinity of clofazimine in nanoparticles. These results strongly suggest that the new clofazimine nanoparticles prepared with affordable materials in this low-cost nanoparticle formulation process can be used as viable cryptosporidiosis therapeutics. PMID:28929769

To Study Capping or Lamination Tendency of Tablets Through Evaluation of Powder Rheological Properties and Tablet Mechanical Properties of Directly Compressible Blends.

PubMed

Dudhat, Siddhi M; Kettler, Charles N; Dave, Rutesh H

2017-05-01

Air entrapment efficiency of the powders is one of the main factors leading to occurrence of capping or lamination tendency of tablets manufactured from the directly compressible powder blends. The purpose of the current research was to study this underlying cause leading to occurrence of capping or lamination of tablets through evaluation of powder rheological properties. Powder blends were prepared by addition of 0% w/w to 100% w/w of individual active pharmaceutical ingredient (API) [two model API: acetaminophen (APAP) and ibuprofen (IBU)] with microcrystalline cellulose without and with 0.5% w/w Magnesium Stearate as lubricant. Powder rheological properties were analyzed using FT4 Powder Rheometer for dynamic, bulk, and shear properties. Tablet mechanical properties of the respective blends were studied by determining the ability of the material to form tablet of specific strength under applied compaction pressure through tabletability profile. The results showed that powder rheometer distinguished the powder blends based on their ability to relieve entrapped air along with the distinctive flow characteristics. Powder blend prepared with increasing addition of APAP displayed low powder permeability as compared to IBU blends with better powder permeability, compressibility and flow characteristics. Also, lubrication of the APAP blends did not ease their ability to relieve air. Tabletability profiles revealed the potential occurrence of capping or lamination in tablets prepared from the powder blends with high APAP content. This study can help scientist to understand tableting performance at the early-developmental stages and can avoid occurrence capping and lamination of tablets.

Determination of lead in Smilax myosotiflora herbal preparations obtained in Malaysia.

PubMed

Ang, H H; Lee, K L; Kiyoshi, M

2004-08-01

The DCA (Drug Control Authority), Malaysia implemented the phase 3 registration of traditional medicines on 1 January 1992 with special emphasis on the quality, efficacy and safety (including the presence of heavy metals) in all pharmaceutical dosage forms of traditional medicinal preparations. As such, a total of 100 traditional medicinal preparations, containing Smilax myosotiflora, in various pharmaceutical dosage forms, which were bought in the Malaysian market, were analysed for lead content using atomic absorption spectrophotometry. Results showed that 15% of the products analysed possessed 10.23-23.05 ppm of lead, and therefore, do not comply with the quality requirement for traditional medicines in Malaysia. The quality requirement for traditional medicines in Malaysia is that they should not exceed 10 ppm of lead. Out of these 15 products, five products exhibited 10.23-23.05 ppm of lead, in fact they have already been registered with the DCA Malaysia. However, the rest of the products, which possessed 12.24-20.72 ppm of lead, have still not been registered with the DCA Malaysia. Although this study successfully showed that only 85% of the products complied with the quality requirement for traditional medicines in Malaysia pertaining to lead, they cannot, however, be assumed to be safe from lead contamination because of batch-to-batch inconsistency.

Piezoelectric and Electrostrictive Materials for Transducer Applications. Volume 3.

DTIC Science & Technology

1988-03-01

the preparation and characterization of these required compositions. High-purity lead acetate, titanium isopropoxide , and zirconium n-propoxide were...method was similar to the procedure used in Reference 4 to prepare PbTiO 3. High-purity lead acetate [Pb(C2 H3 0 2 )2 -3H-2Oj, titanium isopropoxide [Ti(OC...dielectric constant as shown in Figure 14(A). P.𔃿 8 IV. CONCLUSION High-purity lead acetate, titanium isopropoxide and zirconium n-propoxide were used as

Sol-gel preparation of lead magnesium niobate (PMN) powders and thin films

DOEpatents

Boyle, T.J.

1999-01-12

A method of preparing a lead magnesium niobium oxide (PMN), Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}, precursor solution by a solvent method wherein a liquid solution of a lead-complex PMN precursor is combined with a liquid solution of a niobium-complex PMN precursor, the combined lead- and niobium-complex liquid solutions are reacted with a magnesium-alkyl solution, forming a PMN precursor solution and a lead-based precipitate, and the precipitate is separated from the reacted liquid PMN precursor solution to form a precipitate-free PMN precursor solution. This precursor solution can be processed to form both ferroelectric powders and thin films. 3 figs.

Sol-Gel Preparation Of Lead Magnesium Ni Obate (Pmn) Powdersand Thin Films

DOEpatents

Boyle, Timothy J.

1999-01-12

A method of preparing a lead magnesium niobium oxide (PMN), Pb(Mg.sub.1/3 Nb.sub.2/3)O.sub.3, precursor solution by a solvent method wherein a liquid solution of a lead-complex PMN precursor is combined with a liquid solution of a niobium-complex PMN precursor, the combined lead- and niobium-complex liquid solutions are reacted with a magnesium-alkyl solution, forming a PMN precursor solution and a lead-based precipitate, and the precipitate is separated from the reacted liquid PMN precursor solution to form a precipitate-free PMN precursor solution. This precursor solution can be processed to form both ferroelectric powders and thin films.

Children's multiple vitamins: overuse leads to overdose

PubMed Central

Issenman, Robert M.; Slack, Roberta; MacDonald, Lorry; Taylor, Wayne

1985-01-01

A suburban Ontario community hospital encountered 21 ± 1 overdoses of children's multiple vitamins yearly between 1978 and 1981. Of these, 35% involved one particular cartoon character preparation. Parents were surveyed to determine whether this particular preparation resulted in a disproportionate number of accidental overdoses. However, the use of vitamins with a cartoon character format did not lead to a greater risk of overdose than did conventional preparations. Of the 1051 families who had given multiple vitamins to their children 34 (3%) had experienced an overdose. The number of vitamin preparations used by each family was the most powerful determinant of overdose (p < 0.001). The risk of accidental overdose increased from 1.5% with one multiple-vitamin preparation to 8% with four or more preparations. Among all the variables examined, exposure was the most important element in the risk of multiple-vitamin overdose. PMID:3978499

Correlation between the structure and the piezoelectric properties of lead-free (K,Na,Li)(Nb,Ta,Sb)O3 ceramics studied by XRD and Raman spectroscopy.

PubMed

Rubio-Marcos, Fernando; Marchet, Pascal; Romero, Juan José; Fernández, Jose F

2011-09-01

This article reviews on the use of Raman spectroscopy for the study of (K,Na,Li)(Nb,Ta,Sb)O(3) lead-free piezoceramics. Currently, this material appears to be one of the most interesting and promising alternatives to the well-known PZT piezoelectric materials. In this work, we prepare piezoceramics with different stoichiometries and study their structural, ferroelectric, and piezoelectric properties. By using both Raman spectroscopy and X-ray diffraction, we establish a direct correlation between the structure and the properties. The results demonstrate that the wavenumber of the A(1g) vibration is proportional to the tetragonality, the remnant polarization, and the piezoelectric coefficients of these materials. Thus, Raman spectroscopy appears as a very useful technique for a fast evaluation of the crystalline structure and the ferroelectric/ piezoelectric properties.

Biodegradable packing materials from hydrolysates of collagen waste proteins.

PubMed

Langmaier, F; Mokrejs, P; Kolomaznik, K; Mladek, M

2008-01-01

Enzymatic hydrolysates of waste collagen proteins (H), from current industrial manufacture (leather, edible meat product casings, etc.) of mean molecular mass 20-30 kDa by a reaction with dialdehyde starch (DAS), produces hydrogels applicable as biodegradable (or even edible) packaging materials for food, cosmetic and pharmaceutical products. Thermo-reversibility of prepared hydrogels is given by concentrations of H and DAS in a reaction mixture. At concentrations of H 25-30% (w/w) and that of DAS 15-20% (related to weight of hydrolysate), thermo-reversible hydrogels arise, which can be processed into packaging materials by a technique similar to that of soft gelatin capsules (SGC). Exceeding the limit of 20% DAS leads to hydrogels that are thermo-reversible only in part, a further increase in DAS concentration then leads to thermo-irreversible gels whose processing into biodegradable packaging materials necessitates employment of other procedures.

Optimization of cathodic arc deposition and pulsed plasma melting techniques for growing smooth superconducting Pb photoemissive films for SRF injectors

NASA Astrophysics Data System (ADS)

Nietubyć, Robert; Lorkiewicz, Jerzy; Sekutowicz, Jacek; Smedley, John; Kosińska, Anna

2018-05-01

Superconducting photoinjectors have a potential to be the optimal solution for moderate and high current cw operating free electron lasers. For this application, a superconducting lead (Pb) cathode has been proposed to simplify the cathode integration into a 1.3 GHz, TESLA-type, 1.6-cell long purely superconducting gun cavity. In the proposed design, a lead film several micrometres thick is deposited onto a niobium plug attached to the cavity back wall. Traditional lead deposition techniques usually produce very non-uniform emission surfaces and often result in a poor adhesion of the layer. A pulsed plasma melting procedure reducing the non-uniformity of the lead photocathodes is presented. In order to determine the parameters optimal for this procedure, heat transfer from plasma to the film was first modelled to evaluate melting front penetration range and liquid state duration. The obtained results were verified by surface inspection of witness samples. The optimal procedure was used to prepare a photocathode plug, which was then tested in an electron gun. The quantum efficiency and the value of cavity quality factor have been found to satisfy the requirements for an injector of the European-XFEL facility.

Cesium lead halide perovskite quantum dot-based warm white light-emitting diodes with high color rendering index

NASA Astrophysics Data System (ADS)

Bi, Ke; Wang, Dan; Wang, Peng; Duan, Bin; Zhang, Tieqiang; Wang, Yinghui; Zhang, Hanzhuang; Zhang, Yu

2017-05-01

White light-emitting diodes (WLEDs) were fabricated by employing a combination of a commercial yellow emission Ce3+-doped Y3Al5O12 (YAG:Ce)-based phosphor and all-inorganic perovskite quantum dots pumped with blue LED chip. Perovskite quantum dot solution was used as the color conversion layer with liquid-type structure. Red-emitting materials based on cesium lead halide (CsPb(X)3) perovskite quantum dots were introduced to generate WLEDs with high efficacy and high color rendering index through compensating the red emission of the YAG:Ce phosphor-based commercialized WLEDs. The experimental results suggested that the luminous efficiency and color rendering index of the as-prepared WLED device could reach up to 84.7 lm/W and 89, respectively. The characteristics of those devices including correlated color temperature (CCT), color rendering index (CRI), and color coordinates were observed under different forward currents. The as-fabricated warm WLEDs showed excellent color stability against the increasing current, while the color coordinates shifted slightly from (0.3837, 0.3635) at 20 mA to (0.3772, 0.3592) at 120 mA and color temperature tuned from 3803 to 3953 K.

Solvothermal synthesis of α-PbO from lead dioxide and its electrochemical performance as a positive electrode material

NASA Astrophysics Data System (ADS)

Gao, Pengran; Liu, Yi; Bu, Xianfu; Hu, Meng; Dai, Yuan; Gao, Xiaorui; Lei, Lixu

2013-11-01

Lead acid batteries have been widely used and have dominated the global secondary battery market. It is very important to recycle the spent batteries efficiently to eliminate possible pollution and to ensure sustainable production. In this paper, we report our investigation on the solvothermal treatment of PbO2, which is one of the model compounds for the positive active mixture, in methanol and the subsequent calcination of its product. The results show that the solvothermal treatment of PbO2 in pure methanol at 140 °C can produce a mixture of PbO and lead oxide carbonate, which can be calcined at a temperature below 500 °C to produce α-PbO. The as-prepared PbO powders are rod-like particles of about 0.5 micrometer in diameter and several micrometers in length, which can achieve a high discharge capacity of 165 mAh g-1 at the discharge current density of 5 mA g-1, and more than 90 mAh g-1 at 200 mA g-1 with excellent cycle stability. This study demonstrates a new way for the reuse of lead dioxide in spent lead acid batteries to produce highly active PbO.

Unleashing the Full Sustainable Potential of Thick Films of Lead-Free Potassium Sodium Niobate (K0.5Na0.5NbO3) by Aqueous Electrophoretic Deposition.

PubMed

Mahajan, Amit; Pinho, Rui; Dolhen, Morgane; Costa, M Elisabete; Vilarinho, Paula M

2016-05-31

A current challenge for the fabrication of functional oxide-based devices is related with the need of environmental and sustainable materials and processes. By considering both lead-free ferroelectrics of potassium sodium niobate (K0.5Na0.5NbO3, KNN) and aqueous-based electrophoretic deposition here we demonstrate that an eco-friendly aqueous solution-based process can be used to produce KNN thick coatings with improved electromechanical performance. KNN thick films on platinum substrates with thickness varying between 10 and 15 μm have a dielectric permittivity of 495, dielectric losses of 0.08 at 1 MHz, and a piezoelectric coefficient d33 of ∼70 pC/N. At TC these films display a relative permittivity of 2166 and loss tangent of 0.11 at 1 MHz. A comparison of the physical properties between these films and their bulk ceramics counterparts demonstrates the impact of the aqueous-based electrophoretic deposition (EPD) technique for the preparation of lead-free ferroelectric thick films. This opens the door to the possible development of high-performance, lead-free piezoelectric thick films by a sustainable low-cost process, expanding the applicability of lead-free piezoelectrics.

Lead Coolant Test Facility Systems Design, Thermal Hydraulic Analysis and Cost Estimate

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

Soli Khericha; Edwin Harvego; John Svoboda

2012-01-01

The Idaho National Laboratory prepared a preliminary technical and functional requirements (T&FR), thermal hydraulic design and cost estimate for a lead coolant test facility. The purpose of this small scale facility is to simulate lead coolant fast reactor (LFR) coolant flow in an open lattice geometry core using seven electrical rods and liquid lead or lead-bismuth eutectic coolant. Based on review of current world lead or lead-bismuth test facilities and research needs listed in the Generation IV Roadmap, five broad areas of requirements were identified as listed: (1) Develop and Demonstrate Feasibility of Submerged Heat Exchanger; (2) Develop and Demonstratemore » Open-lattice Flow in Electrically Heated Core; (3) Develop and Demonstrate Chemistry Control; (4) Demonstrate Safe Operation; and (5) Provision for Future Testing. This paper discusses the preliminary design of systems, thermal hydraulic analysis, and simplified cost estimate. The facility thermal hydraulic design is based on the maximum simulated core power using seven electrical heater rods of 420 kW; average linear heat generation rate of 300 W/cm. The core inlet temperature for liquid lead or Pb/Bi eutectic is 4200 C. The design includes approximately seventy-five data measurements such as pressure, temperature, and flow rates. The preliminary estimated cost of construction of the facility is $3.7M (in 2006 $). It is also estimated that the facility will require two years to be constructed and ready for operation.« less

Oxygen-permeable microwell device maintains islet mass and integrity during shipping

PubMed Central

Rojas-Canales, Darling M; Waibel, Michaela; Forget, Aurelien; Penko, Daniella; Nitschke, Jodie; Harding, Fran J; Delalat, Bahman; Blencowe, Anton; Loudovaris, Thomas; Grey, Shane T; Thomas, Helen E; Kay, Thomas W H; Drogemuller, Chris J; Voelcker, Nicolas H; Coates, Patrick T

2018-01-01

Islet transplantation is currently the only minimally invasive therapy available for patients with type 1 diabetes that can lead to insulin independence; however, it is limited to only a small number of patients. Although clinical procedures have improved in the isolation and culture of islets, a large number of islets are still lost in the pre-transplant period, limiting the success of this treatment. Moreover, current practice includes islets being prepared at specialized centers, which are sometimes remote to the transplant location. Thus, a critical point of intervention to maintain the quality and quantity of isolated islets is during transportation between isolation centers and the transplanting hospitals, during which 20–40% of functional islets can be lost. The current study investigated the use of an oxygen-permeable PDMS microwell device for long-distance transportation of isolated islets. We demonstrate that the microwell device protected islets from aggregation during transport, maintaining viability and average islet size during shipping. PMID:29483160

Oxygen-permeable microwell device maintains islet mass and integrity during shipping.

PubMed

Rojas-Canales, Darling M; Waibel, Michaela; Forget, Aurelien; Penko, Daniella; Nitschke, Jodie; Harding, Fran J; Delalat, Bahman; Blencowe, Anton; Loudovaris, Thomas; Grey, Shane T; Thomas, Helen E; Kay, Thomas W H; Drogemuller, Chris J; Voelcker, Nicolas H; Coates, Patrick T

2018-03-01

Islet transplantation is currently the only minimally invasive therapy available for patients with type 1 diabetes that can lead to insulin independence; however, it is limited to only a small number of patients. Although clinical procedures have improved in the isolation and culture of islets, a large number of islets are still lost in the pre-transplant period, limiting the success of this treatment. Moreover, current practice includes islets being prepared at specialized centers, which are sometimes remote to the transplant location. Thus, a critical point of intervention to maintain the quality and quantity of isolated islets is during transportation between isolation centers and the transplanting hospitals, during which 20-40% of functional islets can be lost. The current study investigated the use of an oxygen-permeable PDMS microwell device for long-distance transportation of isolated islets. We demonstrate that the microwell device protected islets from aggregation during transport, maintaining viability and average islet size during shipping. © 2018 The authors.

75 FR 13131 - Notice of Intent To Prepare an Environmental Impact Statement (EIS) for the Sale of Plum Island, NY

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-18

..., GSA, as the operational Joint Lead Agency, announces its Notice of Intent (NOI) to prepare an EIS for... York. The US Department of Homeland Security (DHS) will act as a Joint Lead Agency in ongoing...-Action Alternative''). The Action Alternative will be further refined into a series of reasonably...

Ontario School Principals and Diversity: Are They Prepared to Lead for Equity?

ERIC Educational Resources Information Center

Tuters, Stephanie; Portelli, John

2017-01-01

Purpose: Ontario is the most ethnically diverse province in Canada. School educators cannot disregard the reality of diversity in all its senses. The question that directs the focus of this paper is: to what extent are leaders in Ontario formally prepared to lead schools that support the students of today? The paper aims to discuss this issue.…

Strengthening Leadership Preparation to Meet the Challenge of Leading for Learning in the Digital Age: Recommendations from Alumni

ERIC Educational Resources Information Center

Hayashi, Christine A.; Fisher-Adams, Grace

2015-01-01

This study surveys graduates of a west-coast university regarding their perception of how well their graduate degree programs prepared them to meet the challenge of leading for learning in the digital age, particularly in the areas of visionary leadership, student learning, organizational management, working with diverse families, ethics, and the…

Lead zirconate titanate (PZT)-based thin film capacitors for embedded passive applications

NASA Astrophysics Data System (ADS)

Kim, Taeyun

Investigations on the key processing parameters and properties relationship for lead zirconate titanate (PZT, 52/48) based thin film capacitors for embedded passive capacitor application were performed using electroless Ni coated Cu foils as substrates. Undoped and Ca-doped PZT (52/48) thin film capacitors were prepared on electroless Ni coated Cu foil by chemical solution deposition. For PZT (52/48) thin film capacitors on electroless Ni coated Cu foil, voltage independent (zero tunability) capacitance behavior was observed. Dielectric constant reduced to more than half of the identical capacitor processed on Pt/SiO2/Si. Dielectric properties of the capacitors were mostly dependent on the crystallization temperature. Capacitance densities of almost 350 nF/cm2 and 0.02˜0.03 of loss tangent were routinely measured for capacitors crystallized at 575˜600°C. Leakage current showed dependence on film thickness and crystallization temperature. From a two-capacitor model, the existence of a low permittivity interface layer (permittivity ˜30) was suggested. For Ca-doped PZT (52/48) thin film capacitors prepared on Pt, typical ferroelectric and dielectric properties were measured up to 5 mol% Ca doping. When Ca-doped PZT (52/48) thin film capacitors were prepared on electroless Ni coated Cu foil, phase stability was influenced by Ca doping and phosphorous content. Dielectric properties showed dependence on the crystallization temperature and phosphorous content. Capacitance density of ˜400 nF/cm2 was achieved, which is an improvement by more than 30% compared to undoped composition. Ca doping also reduced the temperature coefficient of capacitance (TCC) less than 10%, all of them were consistent in satisfying the requirements of embedded passive capacitor. Leakage current density was not affected significantly by doping. To tailor the dielectric and reliability properties, ZrO2 was selected as buffer layer between PZT and electroless Ni. Only RF magnetron sputtering process could yield stable ZrO2 layers on electroless Ni coated Cu foil. Other processes resulted in secondary phase formation, which supports the reaction between PZT capacitor and electroless Ni might be dominated by phosphorous component. (Abstract shortened by UMI.)

A Preparation Mystery: Why Some Succeed and Others Fail

ERIC Educational Resources Information Center

Hoyle, John R.

2007-01-01

If leadership education programs are improving, then why do some American graduates fail in leading schools and districts even as others succeed? As one way to answer this question, this study explores the preparation, careers, and success or failure of two superintendents prepared in top tier university leadership preparation doctoral programs.…

Teacher Residencies: Redefining Preparation through Partnerships

ERIC Educational Resources Information Center

Coffman, Ann Nutter; Patterson, Richelle

2014-01-01

Teacher preparation plays a critical role in ensuring that teachers are prepared to lead and impact student learning from the first day they are responsible for student learning. The best way to ensure that every teacher is "profession-ready" from their first day as a teacher-of-record is for preparation programs to incorporate teacher…

An assessment of contemporary atomic spectroscopic techniques for the determination of lead in blood and urine matrices

NASA Astrophysics Data System (ADS)

Parsons, Patrick J.; Geraghty, Ciaran; Verostek, Mary Frances

2001-09-01

The preparation and validation of a number of clinical reference materials for the determination of lead in blood and urine is described. Four candidate blood lead reference materials (Lots, 047-050), and four candidate urine lead reference materials (Lots, 034, 035, 037 and 038), containing physiologically-bound lead at clinically relevant concentrations, were circulated to up to 21 selected laboratories specializing in this analysis. Results from two interlaboratory studies were used to establish certified values and uncertainty estimates for these reference materials. These data also provided an assessment of current laboratory techniques for the measurement of lead in blood and urine. For the blood lead measurements, four laboratories used electrothermal atomization AAS, three used anodic stripping voltammetry and one used both ETAAS and ICP-MS. For the urine lead measurements, 11 laboratories used ETAAS (most with Zeeman background correction) and 10 used ICP-MS. Certified blood lead concentrations, ±S.D., ranged from 5.9±0.4 μg/dl (0.28±0.02 μmol/l) to 76.0±2.2 μg/dl (3.67±0.11 μmol/l) and urine lead concentrations ranged from 98±5 μg/l (0.47±0.02 μmol/l) to 641±36 μg/l (3.09±0.17 μmol/l). The highest concentration blood lead material was subjected to multiple analyses using ETAAS over an extended time period. The data indicate that more stringent internal quality control practices are necessary to improve long-term precision. While the certification of blood lead materials was accomplished in a manner consistent with established practices, the urine lead materials proved more troublesome, particularly at concentrations above 600 μg/l (2.90 μmol/l).

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

Wang, Lingyan, E-mail: l.y.wang@mail.xjtu.edu.cn, E-mail: wren@mail.xjtu.edu.cn; Ren, Wei, E-mail: l.y.wang@mail.xjtu.edu.cn, E-mail: wren@mail.xjtu.edu.cn; Shi, Peng

Lead-free ferroelectric un-doped and doped K{sub 0.5}Na{sub 0.5}NbO{sub 3} (KNN) films with different amounts of manganese (Mn) were prepared by a chemical solution deposition method. The thicknesses of all films are about 1.6 μm. Their phase, microstructure, leakage current behavior, and electrical properties were investigated. With increasing the amounts of Mn, the crystallinity became worse. Fortunately, the electrical properties were improved due to the decreased leakage current density after Mn-doping. The study on leakage behaviors shows that the dominant conduction mechanism at low electric field in the un-doped KNN film is ohmic mode and that at high electric field is space-charge-limitedmore » and Pool-Frenkel emission. After Mn doping, the dominant conduction mechanism at high electric field of KNN films changed single space-charge-limited. However, the introduction of higher amount of Mn into the KNN film would lead to a changed conduction mechanism from space-charge-limited to ohmic mode. Consequently, there exists an optimal amount of Mn doping of 2.0 mol. %. The 2.0 mol. % Mn doped KNN film shows the lowest leakage current density and the best electrical properties. With the secondary ion mass spectroscopies and x-ray photoelectron spectroscopy analyses, the homogeneous distribution in the KNN films and entrance of Mn element in the lattice of KNN perovskite structure were also confirmed.« less

Human resource development for nuclear generation - from the perspective of a utility company

NASA Astrophysics Data System (ADS)

Kahar, Wan Shakirah Wan Abdul; Mostafa, Nor Azlan; Salim, Mohd Faiz

2017-01-01

Malaysia is currently in the planning phase of its nuclear power program, with the first unit targeted to be operational in 2030. Training of nuclear power plant (NPP) staffs are usually long and rigorous due to the complexity and safety aspects of nuclear power. As the sole electricity utility in the country, it is therefore essential that Tenaga Nasional Berhad (TNB) prepares early in developing its human resource and nuclear expertise as a potential NPP owner-operator. A utility also has to be prudent in managing its work force efficiently and effectively, while ensuring that adequate preparations are being made to acquire the necessary nuclear knowledge with sufficient training lead time. There are several approaches to training that can be taken by a utility company with no experience in nuclear power. These include conducting feasibility studies and benchmarking exercises, preparing long term human resource development, increasing the exposure on nuclear power technology to both the top management and general staff, and employing the assistance of relevant agencies locally and abroad. This paper discusses the activities done and steps taken by TNB in its human resource development for Malaysia's nuclear power program.

Electric and ferroelectric properties of PZT/BLT multilayer films prepared by photochemical metal-organic deposition

NASA Astrophysics Data System (ADS)

Park, Hyeong-Ho; Lee, Hong-Sub; Park, Hyung-Ho; Hill, Ross H.; Hwang, Yun Taek

2009-01-01

The electric and ferroelectric properties of lead zirconate titanate (PZT) and lanthanum-substituted bismuth titanate (BLT) multilayer films prepared using photosensitive precursors were characterized. The electric and ferroelectric properties were investigated by studying the effect of the stacking order of four ferroelectric layers of PZT or BLT in 4-PZT, PZT/2-BLT/PZT, BLT/2-PZT/BLT, and 4-BLT multilayer films. The remnant polarization values of the 4-BLT and BLT/2-PZT/BLT multilayer films were 12 and 17 μC/cm 2, respectively. Improved ferroelectric properties of the PZT/BLT multilayer films were obtained by using a PZT intermediate layer. The films which contained a BLT layer on the Pt substrate had improved leakage currents of approximately two orders of magnitude and enhanced fatigue resistances compared to the films with a PZT layer on the Pt substrate. These improvements are due to the reduced number of defects and space charges near the Pt electrodes. The PZT/BLT multilayer films prepared by photochemical metal-organic deposition (PMOD) possessed enhanced electric and ferroelectric properties, and allow direct patterning to fabricate micro-patterned systems without dry etching.

Leading Leadership Preparation: 21st Century Designs

ERIC Educational Resources Information Center

Farmer, Tod Allen

2010-01-01

As political accountability and economic reality increasingly influence higher education, many leadership preparation programs are seeking cost effective instructional delivery systems that yield highly effective results. Simultaneously, large numbers of graduate students are seeking quality leadership preparation programs that provide both…

Answering Public Health Concerns Over Japanese Nuclear Disaster | ORAU

ScienceCinema

Allen, Leeanna; Vasconez, Rachel

2018-05-11

When the Fukushima Daiichi Nuclear Power Plant became crippled following Japan's March 2011 earthquake and tsunami, some U.S. citizens became concerned about whether radiation would disperse across the Pacific Ocean. As the Centers for Disease Control and Prevention prepared to assist in the U.S. response effort, ORAU provided the CDC with onsite, staff support at its Joint Information Center. ORAU also had a lead role in the development and execution of the CDC's first-ever Bridging the Gaps: Public Health and Radiation Emergency Preparedness conference, which took place 10 days after the earthquake and served as a forum for discussing the current state of radiation emergency preparedness.

Flexible foils formed by a prolonged electron beam irradiation in scanning electron microscope

NASA Astrophysics Data System (ADS)

Čechal, Jan; Šikola, Tomáš

2017-11-01

The ubiquitous presence of hydrocarbon contamination on solid surfaces alters their inherent physical properties and complicates the surface analyses. An irradiation of sample surface with electron beam can lead to the chemical transformation of the hydrocarbon layer to carbon films, which are flexible and capable of acting as a barrier for chemical etching of an underlying material. The growth of these foils is limited by supply of hydrocarbons to the writing beam position rather than the electron dose or electron beam current. The prepared films can find their applications in fabrication of surface nanostructures without a need of an electron sensitive resist material.

Spray-painted binder-free SnSe electrodes for high-performance energy-storage devices.

PubMed

Wang, Xianfu; Liu, Bin; Xiang, Qingyi; Wang, Qiufan; Hou, Xiaojuan; Chen, Di; Shen, Guozhen

2014-01-01

SnSe nanocrystal electrodes on three-dimensional (3D) carbon fabric and Au-coated polyethylene terephthalate (PET) wafer have been prepared by a simple spray-painting process and were further investigated as binder-free active-electrodes for Lithium-ion batteries (LIBs) and flexible stacked all-solid-state supercapacitors. The as-painted SnSe nanocrystals/carbon fabric electrodes exhibit an outstanding capacity of 676 mAh g(-1) after 80 cycles at a current density of 200 mA g(-1) and a considerable high-rate capability in lithium storage because of the excellent ion transport from the electrolyte to the active materials and the efficient charge transport between current collector and electrode materials. The binder-free electrodes also provide a larger electrochemical active surface compared with electrodes containing binders, which leads to the enhanced capacities of energy-storage devices. A flexible stacked all-solid-state supercapacitor based on the SnSe nanocrystals on Au-coated PET wafers shows high capacitance reversibility with little performance degradation at different current densities after 2200 charge-discharge cycles and even when bent. This allows for many potential applications in facile, cost-effective, spray-paintable, and flexible energy-storage devices. The results indicate that the fabrication of binder-free electrodes by a spray painting process is an interesting direction for the preparation of high-performance energy-storage devices. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Significantly enhanced critical current density in nano-MgB2 grains rapidly formed at low temperature with homogeneous carbon doping

NASA Astrophysics Data System (ADS)

Liu, Yongchang; Lan, Feng; Ma, Zongqing; Chen, Ning; Li, Huijun; Barua, Shaon; Patel, Dipak; Shahriar, M.; Hossain, Al; Acar, S.; Kim, Jung Ho; Xue Dou, Shi

2015-05-01

High performance MgB2 bulks using carbon-coated amorphous boron as a boron precursor were fabricated by Cu-activated sintering at low temperature (600 °C, below the Mg melting point). Dense nano-MgB2 grains with a high level of homogeneous carbon doping were formed in these MgB2 samples. This type of microstructure can provide a stronger flux pinning force, together with depressed volatility and oxidation of Mg owing to the low-temperature Cu-activated sintering, leading to a significant improvement of critical current density (Jc) in the as-prepared samples. In particular, the value of Jc for the carbon-coated (Mg1.1B2)Cu0.05 sample prepared here is even above 1 × 105 A cm-2 at 20 K, 2 T. The results herein suggest that the combination of low-temperature Cu-activated sintering and employment of carbon-coated amorphous boron as a precursor could be a promising technique for the industrial production of practical MgB2 bulks or wires with excellent Jc, as the carbon-coated amorphous boron powder can be produced commercially at low cost, while the addition of Cu is very convenient and inexpensive.

Enzyme-catalyzed crosslinkable hydrogels: emerging strategies for tissue engineering.

PubMed

Teixeira, Liliana S Moreira; Feijen, Jan; van Blitterswijk, Clemens A; Dijkstra, Pieter J; Karperien, Marcel

2012-02-01

State-of-the-art bioactive hydrogels can easily and efficiently be formed by enzyme-catalyzed mild-crosslinking reactions in situ. Yet this cell-friendly and substrate-specific method remains under explored. Hydrogels prepared by using enzyme systems like tyrosinases, transferases and lysyl oxidases show interesting characteristics as dynamic scaffolds and as systems for controlled release. Increased attention is currently paid to hydrogels obtained via crosslinking of precursors by transferases or peroxidases as catalysts. Enzyme-mediated crosslinking has proven its efficiency and attention has now shifted to the development of enzymatically crosslinked hydrogels with higher degrees of complexity, mimicking extracellular matrices. Moreover, bottom-up approaches combining biocatalysts and self-assembly are being explored for the development of complex nano-scale architectures. In this review, the use of enzymatic crosslinking for the preparation of hydrogels as an innovative alternative to other crosslinking methods, such as the commonly used UV-mediated photo-crosslinking or physical crosslinking, will be discussed. Photo-initiator-based crosslinking may induce cytotoxicity in the formed gels, whereas physical crosslinking may lead to gels which do not have sufficient mechanical strength and stability. These limitations can be overcome using enzymes to form covalently crosslinked hydrogels. Herewith, we report the mechanisms involved and current applications, focusing on emerging strategies for tissue engineering and regenerative medicine. Copyright © 2011 Elsevier Ltd. All rights reserved.

Preparing for the future: challenges and opportunities for management and leadership skills.

PubMed

Morison, S; McMullan, C

2013-01-01

The aim of the study was to explore dental leaders' perceptions of the current position of leadership in the dental profession. A qualitative, key informant, exploratory research study was used with semi-structured interviews as the means of data collection. Participants were invited based on their role in dental services in the UK and their ability to act as a key informant. Thirteen participants were secured and interviewed either at their workplace or in a University setting. Each interview lasted between 45 and 60 minutes. The findings show that while recognising that a lack of focus on leadership skills has caused problems in the past, current dental leaders are prepared to lead the profession forward. The participants viewed education at all levels as vital to this process and education for leadership at undergraduate level was perceived as an important way forward. The development of effective leaders is essential for all healthcare professions and increasingly is becoming a key focus for the UK dental profession. There is comparatively little research about dental leadership in a UK context and this paper should begin to help to redress the balance and to highlight areas for future consideration. Three broad emergent themes are described and discussed - characteristics and behaviours of dental leaders; challenges for dental leaders; education and training for dental leadership.

DIII-D Upgrade to Prepare the Basis for Steady-State Burning Plasmas

NASA Astrophysics Data System (ADS)

Buttery, R. J.; Guo, H. Y.; Taylor, T. S.; Wade, M. R.; Hill, D. N.

2014-10-01

Future steady-state burning plasma facilities will access new physics regimes and modes of plasma behavior. It is vital to prepare for this both experimentally using existing facilities, and theoretically in order to develop the tools to project to and optimize these devices. An upgrade to DIII-D is proposed to address the three critical aspects where research must go beyond what we can do now: (i) torque free electron heating to address the energy, particle and momentum transport mechanisms of burning plasmas using electron cyclotron (EC) heating and full power balanced neutral beams; (ii) off-axis heating and current drive to develop the path to true fusion steady state by reorienting neutral beams and deploying EC and helicon current drive; (iii) a new divertor with hot walls and reactor relevant materials to develop the basis for benign detached divertor operation compatible with wall materials and a high performance fusion core. These elements with modest incremental cost and enacted as a user facility for the whole US program will enable the US to lead on ITER and take a decision to proceed with a Fusion Nuclear Science Facility. Work supported by the US Department of Energy under DE-FC02-04ER54698 and DE-AC52-07NA27344.

CURRENT STATUS OF ADVACATE PROCESS FOR FLUE GAS DESULFURIZATION

EPA Science Inventory

The following report discusses current bench- and pilot-plant advances in preparation of ADVAnced siliCATE (ADVACATE) calcium silicate sorbentsfor flue gas desulfurization. It also discusses current bench- and pilot-plant advances in sorbent preparation. Fly ash was ground in a l...

Combining Theory, Model, and Experiment to Explain How Intrinsic Theta Rhythms Are Generated in an In Vitro Whole Hippocampus Preparation without Oscillatory Inputs

PubMed Central

Ferguson, Katie A.

2017-01-01

Abstract Scientists have observed local field potential theta rhythms (3–12 Hz) in the hippocampus for decades, but understanding the mechanisms underlying their generation is complicated by their diversity in pharmacological and frequency profiles. In addition, interactions with other brain structures and oscillatory drives to the hippocampus during distinct brain states has made it difficult to identify hippocampus-specific properties directly involved in theta generation. To overcome this, we develop cellular-based network models using a whole hippocampus in vitro preparation that spontaneously generates theta rhythms. Building on theoretical and computational analyses, we find that spike frequency adaptation and postinhibitory rebound constitute a basis for theta generation in large, minimally connected CA1 pyramidal (PYR) cell network models with fast-firing parvalbumin-positive (PV+) inhibitory cells. Sparse firing of PYR cells and large excitatory currents onto PV+ cells are present as in experiments. The particular theta frequency is more controlled by PYR-to-PV+ cell interactions rather than PV+-to-PYR cell interactions. We identify two scenarios by which theta rhythms can emerge, and they can be differentiated by the ratio of excitatory to inhibitory currents to PV+ cells, but not to PYR cells. Only one of the scenarios is consistent with data from the whole hippocampus preparation, which leads to the prediction that the connection probability from PV+ to PYR cells needs to be larger than from PYR to PV+ cells. Our models can serve as a platform on which to build and develop an understanding of in vivo theta generation. PMID:28791333

Lead paste recycling based on conversion into battery grade oxides. Electrochemical tests and industrial production of new batteries

NASA Astrophysics Data System (ADS)

Fusillo, G.; Rosestolato, D.; Scura, F.; Cattarin, S.; Mattarozzi, L.; Guerriero, P.; Gambirasi, A.; Brianese, N.; Staiti, P.; Guerriero, R.; La Sala, G.

2018-03-01

We present the preparation and characterization of pure lead monoxide obtained through recycling of the lead paste recovered from exhausted lead acid batteries. The recycling is based on a hydrometallurgical procedure reported in a STC Patent, that includes simple chemical operations (desulphurisation, leaching, precipitation, filtration) and a final thermal conversion. Materials obtained by treatment at 600 °C consist predominantly of β-PbO. The electrochemical behaviour of Positive Active Mass (PAM) prepared from different materials (or mixtures) is then investigated and compared. An optimized oxide material, obtained by prolonged (8 h) thermal treatment at 600 °C, consists of pure β-PbO and appears suitable for preparation of battery elements, alone or in mixture with a small fraction (10%-30%) of traditional industrial leady oxide. The resulting battery performances are similar to those obtained from pure leady oxide. In comparison with traditional recycling processes, the proposed method guarantees lower energy consumption, limited environmental impact and reduced operating risk for industry workers.

Technology and techniques for parity experiments at Mainz: Past, Present and Future

NASA Astrophysics Data System (ADS)

Diefenbach, Juergen

2016-03-01

For almost 20 years the Mainz accelerator facility MAMI delivered polarized electron beam to the parity violation experiment A4 that measured the contributions of strange sea quarks to the proton electromagnetic factors. Parity violation asymmetries were of the order of A ~5 ppm. Currently the A1 collaboration carries out single spin asymmetry measurements at MAMI (A ~20 ppm) to prepare for a measurement of neutron skin depth on lead (A ~1 ppm). For such high precision experiments active stabilization and precise determination of beam parameters like current, energy, position, and angle are essential requirements in addition to precision electron beam polarimetry. For the future P2 experiment at the planned superconducting accelerator MESA in Mainz the requirements for beam quality will be even higher. P2 will measure the weak mixing angle with 0.15 percent total uncertainty and, in addition, the neutron skin depth of lead as well as parity violation in electron scattering off 12C. A tiny asymmetry of only -0.03 ppm creates the needs to combine digital feedback with feedforward stabilizations along with new polarimetry developments like a hydro-Moller and a double-Mott polarimeter to meet the goals for systematic uncertainty. This talk gives an overview of our experience with polarimetry, analog feedbacks and compensation techniques for apparative asymmetries at the A4 experiment. It finally leads to the requirements and new techniques for the pioneering P2 experiment at MESA. First results from beam tests currently carried out at the existing MAMI accelerator, employing high speed analog/digital conversion and FPGAs for control of beam parameters, will be presented. Supported by the cluster of excellence PRISMA and the Deutsche Forschungsgemeinschaft in the framework of the SFB1044.

Preparation of pancreatic β-cells from human iPS cells with small molecules

PubMed Central

2012-01-01

Human induced pluripotent stem (iPS) cells obtained from patients are expected to be a useful source for cell transplantation therapy, because many patients (including those with type 1 diabetes and severe type 2 diabetes) are on waiting lists for transplantation for a long time due to the shortage of donors. At present, many concerns related to clinical application of human iPS cells have been raised, but rapid development of methods for the establishment, culture, and standardization of iPS cells will lead autologous cell therapy to be realistic sooner or later. However, establishment of a method for preparing some of desired cell types is still challenging. Regarding pancreatic β-cells, there have been many reports about differentiation of these cells from human embryonic stem (ES)/iPS cells, but a protocol for clinical application has still not been established. Since there is clear proof that cell transplantation therapy is effective for diabetes based on the results of clinical islet transplantation, pancreatic β-cells prepared from human iPS cells are considered likely to be effective for reducing the burden on patients. In this article, the current status of procedures for preparing pancreatic β-cells from human ES/iPS cells, including effective use of small molecules, is summarized, and some of the problems that still need to be overcome are discussed. PMID:22722666

Further Investigation Into the Use of Laser Surface Preparation of Ti-6Al-4V Alloy for Adhesive Bonding

NASA Technical Reports Server (NTRS)

Palmieri, Frank L.; Crow, Allison; Zetterberg, Anna; Hopkins, John; Wohl, Christopher J.; Connell, John W.; Belcher, Tony; Blohowiak, Kay Y.

2014-01-01

Adhesive bonding offers many advantages over mechanical fastening, but requires robust materials and processing methodologies before it can be incorporated in primary structures for aerospace applications. Surface preparation is widely recognized as one of the key steps to producing robust and predictable bonds. This report documents an ongoing investigation of a surface preparation technique based on Nd:YAG laser ablation as a replacement for the chemical etch and/or abrasive processes currently applied to Ti-6Al-4V alloys. Laser ablation imparts both topographical and chemical changes to a surface that can lead to increased bond durability. A laser based process provides an alternative to chemical-immersion, manual abrasion, and grit blast process steps which are expensive, hazardous, environmentally unfriendly, and less precise. In addition, laser ablation is amenable to process automation, which can improve reproducibility to meet quality standards for surface preparation. An update on work involving adhesive property testing, surface characterization, surface stability, and the effect of laser surface treatment on fatigue behavior is presented. Based on the tests conducted, laser surface treatment is a viable replacement for the immersion chemical surface treatment processes. Testing also showed that the fatigue behavior of the Ti-6Al-4V alloy is comparable for surfaces treated with either laser ablation or chemical surface treatment.

Silane surface modification effects on the electromagnetic properties of phosphatized iron-based SMCs

NASA Astrophysics Data System (ADS)

Fan, Liang-Fang; Hsiang, Hsing-I.; Hung, Jia-Jing

2018-03-01

It is difficult to achieve homogeneous phosphatized iron powder dispersion in organic resins during the preparation of soft magnetic composites (SMCs). Inhomogeneous iron powder mixing in organic resins generally leads to the formation of micro-structural defects in SMCs and hence causes the magnetic properties to become worse. Phosphatized iron powder dispersion in organic resins can be improved by coating the phosphatized iron powder surfaces with a coupling agent. This study investigated the (3-aminopropyl) triethoxysilane (APTES) surface modification effects on the electromagnetic properties of phosphatized iron-based soft magnetic composites (SMCs). The results showed that the phosphatized iron powder surface can be modified using APTES to improve the phosphatized iron powder and epoxy resin compatibility and hence enhance phosphate iron powder epoxy mixing. The tensile strength, initial permeability, rated current under DC-bias superposition and magnetic loss in SMCs prepared using phosphatized iron powders can be effectively improved using APTES surface modification, which provides a promising candidate for power chip inductor applications.

Band gap grading and photovoltaic performance of solution-processed Cu(In,Ga)S2 thin-film solar cells.

PubMed

Sohn, So Hyeong; Han, Noh Soo; Park, Yong Jin; Park, Seung Min; An, Hee Sang; Kim, Dong-Wook; Min, Byoung Koun; Song, Jae Kyu

2014-12-28

The photophysical properties of CuInxGa1-xS2 (CIGS) thin films, prepared by solution-based coating methods, are investigated to understand the correlation between the optical properties of these films and the electrical characteristics of solar cells fabricated using these films. Photophysical properties, such as the depth-dependent band gap and carrier lifetime, turn out to be at play in determining the energy conversion efficiency of solar cells. A double grading of the band gap in CIGS films enhances solar cell efficiency, even when defect states disturb carrier collection by non-radiative decay. The combinational stacking of different density films leads to improved solar cell performance as well as efficient fabrication because a graded band gap and reduced shunt current increase carrier collection efficiency. The photodynamics of minority-carriers suggests that the suppression of defect states is a primary area of improvement in CIGS thin films prepared by solution-based methods.

Chlorine doped graphene quantum dots: Preparation, properties, and photovoltaic detectors

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

Zhao, Jianhong; Xiang, Jinzhong, E-mail: jzhxiang@ynu.edu.cn; Tang, Libin, E-mail: scitang@163.com

Graphene quantum dots (GQDs) are becoming one of the hottest advanced functional materials because of the opening of the bandgap due to quantum confinement effect, which shows unique optical and electrical properties. The chlorine doped GQDs (Cl-GQDs) have been fabricated by chemical exfoliation of HCl treated carbon fibers (CFs), which were prepared from degreasing cotton through an annealing process at 1000 °C for 30 min. Raman study shows that both G and 2D peaks of GQDs may be redshifted (softened) by chlorine doping, leading to an n-type doping. The first vertical (Cl)-GQDs based photovoltaic detectors have been demonstrated, both the light absorbingmore » and electron-accepting roles for (Cl)-GQDs in photodetection have been found, resulting in an exceptionally big ratio of photocurrent to dark current as high as ∼10{sup 5} at room temperature using a 405 nm laser irradiation under the reverse bias voltage. The study expands the application of (Cl)-GQDs to the important optoelectronic detection devices.« less

Hydrophobic benzyl amines as supports for liquid-phase C-terminal amidated peptide synthesis: application to the preparation of ABT-510.

PubMed

Matsumoto, Emiko; Fujita, Yuko; Okada, Yohei; Kauppinen, Esko I; Kamiya, Hidehiro; Chiba, Kazuhiro

2015-09-01

C-terminal amidation is one of the most common modification of peptides and frequently found in bioactive peptides. However, the C-terminal modification must be creative, because current chemical synthetic techniques of peptides are dominated by the use of C-terminal protecting supports. Therefore, it must be carried out after the removal of such supports, complicating reaction work-up and product isolation. In this context, hydrophobic benzyl amines were successfully added to the growing toolbox of soluble tag-assisted liquid-phase peptide synthesis as supports, leading to the total synthesis of ABT-510 (2). Although an ethyl amide-forming type was used in the present work, different types of hydrophobic benzyl amines could also be simply designed and prepared through versatile reductive aminations in one step. The standard acidic treatment used in the final deprotection step for peptide synthesis gave the desired C-terminal secondary amidated peptide with no epimerization. Copyright © 2015 European Peptide Society and John Wiley & Sons, Ltd.

Influence of Sm2O3 microalloying and Yb contamination on Y211 particles coarsening and superconducting properties of IG YBCO bulk superconductors

NASA Astrophysics Data System (ADS)

Vojtkova, L.; Diko, P.; Kovac, J.; Vojtko, M.

2018-06-01

Single grain YBa2Cu3O7‑x (YBCO or Y123) bulk superconductors were produced by an infiltration growth process. The solid phase precursor was prepared by solid state synthesis from Y2O3 + BaCuO2 powders. The influence of the addition of Sm2O3 and YB contamination from the substrate on the microstructure and superconducting properties was analyzed. The dependences of Yb concentration on the distance from the bottom of the samples measured by energy dispersive spectroscopy microanalysis used in conjunction with scanning electron microscopy confirmed the contamination of the samples during the melting stage of the sample preparation. It is shown that the addition of Sm in low concentration and its combination with Yb from the substrate modify the coarsening of the Y211 particles as well as lead to the appearance of a secondary peak effect in the field dependences of the critical current density.

[Study on Content Determination of Lead and Arsenic in Four Traditional Tibetan Medicine Prescription Preparations by Wet Digestion Flow Injection-Hydride Generation-Atomic Absorption Spectrometry].

PubMed

Zheng, Zhi-yuan; Du, Yu-zhi; Zhang, Ming; Yu, Ming-jie; Li, Cen; Yang, Hong-xia; Zhao, Jing; Xia, Zheng-hua; Wei, Li-xin

2015-04-01

Four common traditional tibetan medicine prescription preparations "Anzhijinghuasan, Dangzuo, Renqingchangjue and Rannasangpei" in tibetan areas were selected as study objects in the present study. The purpose was to try to establish a kind of wet digestion and flow injection-hydride generation-atomic absorption spectrometry (FI-HAAS) associated analysis method for the content determinations of lead and arsenic in traditional tibetan medicine under optimized digestion and measurement conditions and determine their contents accurately. Under these optimum operating conditions, experimental results were as follows. The detection limits for lead and arsenic were 0.067 and 0.012 µg · mL(-1) respectively. The quantification limits for lead and arsenic were 0.22 and 0.041 µg · mL(-1) respectively. The linear ranges for lead and arsenic were 25-1,600 ng · mL(-1) (r = 0.9995) and 12.5-800 ng · mL(-1) (r = 0.9994) respectively. The degrees of precision(RSD) for lead and arsenic were 2.0% and 3.2% respectively. The recovery rates for lead and arsenic were 98.00%-99.98% and 96.67%-99.87% respectively. The content determination results of lead and arsenic in four traditional tibetan medicine prescription preparations were as fol- lows. The contents of lead and arsenic in Anzhijinghuasan are 0.63-0.67 µg · g(-1) and 0.32-0.33 µg · g(-1) in Anzhijinghua- san, 42.92-43.36 µg · g(-1) and 24.67-25.87 µg · g(-1) in Dangzuo, 1,611. 39-1,631.36 µg · g(-1) and 926.76-956.52 µg- g(-1) in Renqing Changjue, and 1,102.28-1,119.127 µg-g(-1) and 509.96-516.87 µg · g(-1) in Rannasangpei, respectively. This study established a method for content determination of lead and arsenic in traditional tibetan medicine, and determined the content levels of lead and arsenic in four tibetan medicine-prescription preparations accurately. In addition, these results also provide the basis for the safe and effective use of those medicines in clinic.

A Call for Reformation of Teacher Preparation Programs in the United States

ERIC Educational Resources Information Center

Dann, Ashley Ireland

2014-01-01

Although current research, educational theorists, and international comparison prove a need for reform, the United States' teacher preparation programs are failing. The following paper will call for the reform of teacher preparation programs in three distinct areas. Examination of current data, application of educational theorists'…

An optimized velocity selective arterial spin labeling module with reduced eddy current sensitivity for improved perfusion quantification.

PubMed

Meakin, James A; Jezzard, Peter

2013-03-01

Velocity-selective (VS) arterial spin labeling is a promising method for measuring perfusion in areas of slow or collateral flow by eliminating the bolus arrival delay associated with other spin labeling techniques. However, B(0) and B(1) inhomogeneities and eddy currents during the VS preparation hinder accurate quantification of perfusion with VS arterial spin labeling. In this study, it is demonstrated through simulations and experiments in healthy volunteers that eddy currents cause erroneous tagging of static tissue. Consequently, mean gray matter perfusion is overestimated by up to a factor of 2, depending on the VS preparation used. A novel eight-segment B(1) insensitive rotation VS preparation is proposed to reduce eddy current effects while maintaining the B(0) and B(1) insensitivity of previous preparations. Compared to two previous VS preparations, the eight-segment B(1) insensitive rotation is the most robust to eddy currents and should improve the quality and reliability of VS arterial spin labeling measurements in future studies. Copyright © 2012 Wiley Periodicals, Inc.

Perpendicular magnetic anisotropy in Mn2CoAl thin film

NASA Astrophysics Data System (ADS)

Sun, N. Y.; Zhang, Y. Q.; Fu, H. R.; Che, W. R.; You, C. Y.; Shan, R.

2016-01-01

Heusler compound Mn2CoAl (MCA) is attracting more attentions due to many novel properties, such as high resistance, semiconducting behavior and suggestion as a spin-gapless material with a low magnetic moment. In this work, Mn2CoAl epitaxial thin film was prepared on MgO(100) substrate by magnetron sputtering. The transport property of the film exhibits a semiconducting-like behavior. Moreover, our research reveals that perpendicular magnetic anisotropy (PMA) can be induced in very thin Mn2CoAl films resulting from Mn-O and Co-O bonding at Mn2CoAl/MgO interface, which coincides with a recent theoretical prediction. PMA and low saturation magnetic moment could lead to large spin-transfer torque with low current density in principle, and thus our work may bring some unanticipated Heusler compounds into spintronics topics such as the domain wall motion and the current-induced magnetization reversal.

4D Printed Actuators with Soft-Robotic Functions.

PubMed

López-Valdeolivas, María; Liu, Danqing; Broer, Dick Jan; Sánchez-Somolinos, Carlos

2018-03-01

Soft matter elements undergoing programed, reversible shape change can contribute to fundamental advance in areas such as optics, medicine, microfluidics, and robotics. Crosslinked liquid crystalline polymers have demonstrated huge potential to implement soft responsive elements; however, the complexity and size of the actuators are limited by the current dominant thin-film geometry processing toolbox. Using 3D printing, stimuli-responsive liquid crystalline elastomeric structures are created here. The printing process prescribes a reversible shape-morphing behavior, offering a new paradigm for active polymer system preparation. The additive character of this technology also leads to unprecedented geometries, complex functions, and sizes beyond those of typical thin-films. The fundamental concepts and devices presented therefore overcome the current limitations of actuation energy available from thin-films, thereby narrowing the gap between materials and practical applications. © 2017 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Multidirectional Efficacy of Biologically Active Nitro Compounds Included in Medicines.

PubMed

Olender, Dorota; Żwawiak, Justyna; Zaprutko, Lucjusz

2018-05-29

The current concept in searching for new bioactive products, including mainly original active substances with potential application in pharmacy and medicine, is based on compounds with a previously determined structure, well-known properties, and biological activity profile. Nowadays, many commonly used drugs originated from natural sources. Moreover, some natural materials have become the source of leading structures for processing further chemical modifications. Many organic compounds with great therapeutic significance have the nitro group in their structure. Very often, nitro compounds are active substances in many well-known preparations belonging to different groups of medicines that are classified according to their pharmacological potencies. Moreover, the nitro group is part of the chemical structure of veterinary drugs. In this review, we describe many bioactive substances with the nitro group, divided into ten categories, including substances with exciting activity and that are currently undergoing clinical trials.

24 CFR 35.1345 - Occupant protection and worksite preparation.

Code of Federal Regulations, 2011 CFR

2011-04-01

... Housing and Urban Development LEAD-BASED PAINT POISONING PREVENTION IN CERTAIN RESIDENTIAL STRUCTURES Methods and Standards for Lead-Paint Hazard Evaluation and Hazard Reduction Activities § 35.1345 Occupant... occupants and the environment from contamination from lead-contaminated or lead-containing materials during...

24 CFR 35.1345 - Occupant protection and worksite preparation.

Code of Federal Regulations, 2012 CFR

2012-04-01

... Housing and Urban Development LEAD-BASED PAINT POISONING PREVENTION IN CERTAIN RESIDENTIAL STRUCTURES Methods and Standards for Lead-Paint Hazard Evaluation and Hazard Reduction Activities § 35.1345 Occupant... occupants and the environment from contamination from lead-contaminated or lead-containing materials during...

24 CFR 35.1345 - Occupant protection and worksite preparation.

Code of Federal Regulations, 2013 CFR

2013-04-01

... Housing and Urban Development LEAD-BASED PAINT POISONING PREVENTION IN CERTAIN RESIDENTIAL STRUCTURES Methods and Standards for Lead-Paint Hazard Evaluation and Hazard Reduction Activities § 35.1345 Occupant... occupants and the environment from contamination from lead-contaminated or lead-containing materials during...

24 CFR 35.1345 - Occupant protection and worksite preparation.

Code of Federal Regulations, 2010 CFR

2010-04-01

... Housing and Urban Development LEAD-BASED PAINT POISONING PREVENTION IN CERTAIN RESIDENTIAL STRUCTURES Methods and Standards for Lead-Paint Hazard Evaluation and Hazard Reduction Activities § 35.1345 Occupant... occupants and the environment from contamination from lead-contaminated or lead-containing materials during...

24 CFR 35.1345 - Occupant protection and worksite preparation.

Code of Federal Regulations, 2014 CFR

2014-04-01

... Housing and Urban Development LEAD-BASED PAINT POISONING PREVENTION IN CERTAIN RESIDENTIAL STRUCTURES Methods and Standards for Lead-Paint Hazard Evaluation and Hazard Reduction Activities § 35.1345 Occupant... occupants and the environment from contamination from lead-contaminated or lead-containing materials during...

Thickness dependence of the poling and current-voltage characteristics of paint films made up of lead zirconate titanate ceramic powder and epoxy resin

NASA Astrophysics Data System (ADS)

Egusa, Shigenori; Iwasawa, Naozumi

1995-11-01

A specially prepared paint made up of lead zirconate titanate (PZT) ceramic powder and epoxy resin was coated on an aluminum plate and was cured at room temperature, thus forming the paint film of 25-300 μm thickness with a PZT volume fraction of 53%. The paint film was then poled at room temperature, and the poling behavior was determined by measuring the piezoelectric activity as a function of poling field. The poling behavior shows that the piezoelectric activity obtained at a given poling field increases with an increase in the film thickness from 25 to 300 μm. The current-voltage characteristic of the paint film, on the other hand, shows that the increase in the film thickness leads not only to an increase in the magnitude of the current density at a given electric field but also to an increase in the critical electric field at which the transition from the ohmic to space-charge-limited conduction takes place. This fact indicates that the amount of the space charge of electrons injected into the paint film decreases as the film thickness increases. Furthermore, comparison of the current-voltage characteristic of the paint film with that of a pure epoxy film reveals that the space charge is accumulated largely at the interface between the PZT and epoxy phases in the paint film. On the basis of this finding, a model is developed for the poling behavior of the paint film by taking into account a possible effect of the space-charge accumulation and a broad distribution of the electric field in the PZT phase. This model is shown to give an excellent fit to the experimental data of the piezoelectric activity obtained here as a function of poling field and film thickness.

Micro and macro approaches to tough polymers for composites

NASA Technical Reports Server (NTRS)

Yee, Albert F.; Parker, Douglas S.; Mcgrady, Katherine A. W.; Jho, Jae

1987-01-01

The progress to date on the development of techniques to toughen continuous thermoplastic composites is summarized. The work, using the approach of toughening the polycarbonate composite matrix with rubber particles, has focused on determining the differences between Double Cantilever Beam (DCB) samples molded inhouse and those molded by NASA. Specifically, an effort was made to account for the differences in fracture toughness observed between the various specimens. In addition, preliminary results of tensile dilatometry tests are described; these tests suggest that processes leading to increased volume and enhanced shear banding are occurring within the rubber toughened system. The results of the effort using another approach, the preparation of random block copolycarbonates, are presented. The synthetic route to these species was modified so that higher molecular weights of these materials can be obtained. In addition, an attempt is being made to determine the exact block length or the number of functional groups in the oligomers since this procedure also should lead to high molecular weight materials. Dynamic mechanical analysis of the copolymer prepared so far indicates that the scale of cooperative molecular motion of the PBA polycarbonate at sub-Tg temperatures is larger than five monomer units. Efforts to find a suitable rubber-toughener for a thermoset system (bismaleimides) is also discussed. Included is a description of the various tougheners intended for use or currently being used.

A Solution-Based Approach for Mo-99 Production: Considerations for Nitrate versus Sulfate Media

DOE PAGES

Youker, Amanda J.; Chemerisov, Sergey D.; Kalensky, Michael; ...

2013-01-01

Molybdenum-99 is the parent of Technetium-99m, which is used in nearly 80% of all nuclear medicine procedures. The medical community has been plagued by Mo-99 shortages due to aging reactors, such as the NRU (National Research Universal) reactor in Canada. There are currently no US producers of Mo-99, and NRU is scheduled for shutdown in 2016, which means that another Mo-99 shortage is imminent unless a potential domestic Mo-99 producer fills the void. Argonne National Laboratory is assisting two potential domestic suppliers of Mo-99 by examining the effects of a uranyl nitrate versus a uranyl sulfate target solution configuration onmore » Mo-99 production. Uranyl nitrate solutions are easier to prepare and do not generate detectable amounts of peroxide upon irradiation, but a high radiation field can lead to a large increase in pH, which can lead to the precipitation of fission products and uranyl hydroxides. Uranyl sulfate solutions are more difficult to prepare, and enough peroxide is generated during irradiation to cause precipitation of uranyl peroxide, but this can be prevented by adding a catalyst to the solution. A titania sorbent can be used to recover Mo-99 from a highly concentrated uranyl nitrate or uranyl sulfate solution; however, different approaches must be taken to prevent precipitation during Mo-99 production.« less

21 CFR 25.44 - Lead and cooperating agencies.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Lead and cooperating agencies. 25.44 Section 25.44... ENVIRONMENTAL IMPACT CONSIDERATIONS Preparation of Environmental Documents § 25.44 Lead and cooperating agencies... which will be the lead agency and which will be the cooperating agencies. The responsibilities of lead...

21 CFR 25.44 - Lead and cooperating agencies.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Lead and cooperating agencies. 25.44 Section 25.44... ENVIRONMENTAL IMPACT CONSIDERATIONS Preparation of Environmental Documents § 25.44 Lead and cooperating agencies... which will be the lead agency and which will be the cooperating agencies. The responsibilities of lead...

21 CFR 25.44 - Lead and cooperating agencies.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 1 2012-04-01 2012-04-01 false Lead and cooperating agencies. 25.44 Section 25.44... ENVIRONMENTAL IMPACT CONSIDERATIONS Preparation of Environmental Documents § 25.44 Lead and cooperating agencies... which will be the lead agency and which will be the cooperating agencies. The responsibilities of lead...

21 CFR 25.44 - Lead and cooperating agencies.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 1 2014-04-01 2014-04-01 false Lead and cooperating agencies. 25.44 Section 25.44... ENVIRONMENTAL IMPACT CONSIDERATIONS Preparation of Environmental Documents § 25.44 Lead and cooperating agencies... which will be the lead agency and which will be the cooperating agencies. The responsibilities of lead...

Green primaries: Environmentally friendly energetic complexes

PubMed Central

Huynh, My Hang V.; Hiskey, Michael A.; Meyer, Thomas J.; Wetzler, Modi

2006-01-01

Primary explosives are used in small quantities to generate a detonation wave when subjected to a flame, heat, impact, electric spark, or friction. Detonation of the primary explosive initiates the secondary booster or main-charge explosive or propellant. Long-term use of lead azide and lead styphnate as primary explosives has resulted in lead contamination at artillery and firing ranges and become a major health hazard and environmental problem for both military and civilian personnel. Devices using lead primary explosives are manufactured by the tens of millions every year in the United States from primers for bullets to detonators for mining. Although substantial synthetic efforts have long been focused on the search for greener primary explosives, this unresolved problem has become a “holy grail” of energetic materials research. Existing candidates suffer from instability or excessive sensitivity, or they possess toxic metals or perchlorate. We report here four previously undescribed green primary explosives based on complex metal dianions and environmentally benign cations, (cat)2[MII(NT)4(H2O)2] (where cat is NH4+ or Na+, M is Fe2+ or Cu2+, and NT− is 5-nitrotetrazolato-N2). They are safer to prepare, handle, and transport than lead compounds, have comparable initiation efficiencies to lead azide, and offer rapid reliable detonation comparable with lead styphnate. Remarkably, they possess all current requirements for green primary explosives and are suitable to replace lead primary explosives in detonators. More importantly, they can be synthesized more safely, do not pose health risks to personnel, and cause much less pollution to the environment. PMID:16567623

Student-Prepared Games as a Teaching Strategy

ERIC Educational Resources Information Center

Brisk, William J.

1974-01-01

A course on game preparation attended by students from different disciplines involved an exposure to various types of games, leading up to individual and group development of games. Two of the games developed, Senate and Disarmament, described in the article, exemplify the benefit in hard deductive reasoning required by game preparation. (JH)

40 CFR 1501.5 - Lead agencies.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 33 2011-07-01 2011-07-01 false Lead agencies. 1501.5 Section 1501.5 Protection of Environment COUNCIL ON ENVIRONMENTAL QUALITY NEPA AND AGENCY PLANNING § 1501.5 Lead agencies. (a) A lead agency shall supervise the preparation of an environmental impact statement if more than...

40 CFR 1501.5 - Lead agencies.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Lead agencies. 1501.5 Section 1501.5 Protection of Environment COUNCIL ON ENVIRONMENTAL QUALITY NEPA AND AGENCY PLANNING § 1501.5 Lead agencies. (a) A lead agency shall supervise the preparation of an environmental impact statement if more than...

40 CFR 1501.5 - Lead agencies.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 34 2012-07-01 2012-07-01 false Lead agencies. 1501.5 Section 1501.5 Protection of Environment COUNCIL ON ENVIRONMENTAL QUALITY NEPA AND AGENCY PLANNING § 1501.5 Lead agencies. (a) A lead agency shall supervise the preparation of an environmental impact statement if more than...

40 CFR 1501.5 - Lead agencies.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 34 2013-07-01 2013-07-01 false Lead agencies. 1501.5 Section 1501.5 Protection of Environment COUNCIL ON ENVIRONMENTAL QUALITY NEPA AND AGENCY PLANNING § 1501.5 Lead agencies. (a) A lead agency shall supervise the preparation of an environmental impact statement if more than...

40 CFR 1501.5 - Lead agencies.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 33 2014-07-01 2014-07-01 false Lead agencies. 1501.5 Section 1501.5 Protection of Environment COUNCIL ON ENVIRONMENTAL QUALITY NEPA AND AGENCY PLANNING § 1501.5 Lead agencies. (a) A lead agency shall supervise the preparation of an environmental impact statement if more than...

Preparation and optical characteristics of layered perovskite-type lead-bromide-incorporated azobenzene chromophores

NASA Astrophysics Data System (ADS)

Sasai, Ryo; Shinomura, Hisashi

2013-02-01

Lead bromide-based layered perovskite powders with azobenzene derivatives were prepared by a homogeneous precipitation method. From the diffuse reflectance (DR) and photoluminescence (PL) spectra of the hybrid powder materials, the present hybrids exhibited sharp absorption and PL peaks originating from excitons produced in the PbBr42- layer. When the present hybrid powder was irradiated with UV light at 350 nm, the absorption band from the trans-azobenzene chromophore, observed around 350 nm, decreased, while the absorption band from the cis-azobenzene chromophore, observed around 450 nm, increased. These results indicate that azobenzene chromophores in the present hybrid materials exhibit reversible photoisomerization. Moreover, it was found that the PL intensity from the exciton also varied due to photoisomerization of the azobenzene chromophores in the present hybrid. Thus, for the first time we succeeded in preparing the azobenzene derivative lead-bromide-based layered perovskite with photochromism before and after UV light irradiation.

[Enterobiasis in pediatric subjects in north-western Italy: a study of home remedies].

PubMed

Dutto, M; Montù, D; Raineri, G

2012-01-01

The present study examines the most common home remedies in the Piedmont region of northwest Italy currently used in the treatment of pediatric enterobiasis, commonly known as pinworm infection. The remedies in question, typically based on popular beliefs and as such are nearly useless, were noted through interviews with subjects who had come to the local Hygiene and Public Health Services offices for information about pinworm prevention and treatment. Analysis of replies by the subjects clearly indicates that local families are ill-prepared to recognize the symptoms this parasitic infection; often it is confused with pediatric ketosis, therefore leading to inappropriate treatment which at times may be potentially harmful to the patient.

Decentralizing the Team Station: Simulation before Reality as a Best-Practice Approach.

PubMed

Charko, Jackie; Geertsen, Alice; O'Brien, Patrick; Rouse, Wendy; Shahid, Ammarah; Hardenne, Denise

2016-01-01

The purpose of this article is to share the logistical planning requirements and simulation experience of one Canadian hospital as it prepared its staff for the change from a centralized inpatient unit model to the decentralized design planned for its new community hospital. With the commitment and support of senior leadership, project management resources and clinical leads worked collaboratively to design a decentralized prototype in the form of a pod-style environment in the hospital's current setting. Critical success factors included engaging the right stakeholders, providing an opportunity to test new workflows and technology, creating a strong communication plan and building on lessons learned as subsequent pod prototypes are launched.

Answering Public Health Concerns Over Japanese Nuclear Disaster | ORAU

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

Allen, Leeanna; Vasconez, Rachel

When the Fukushima Daiichi Nuclear Power Plant became crippled following Japan's March 2011 earthquake and tsunami, some U.S. citizens became concerned about whether radiation would disperse across the Pacific Ocean. As the Centers for Disease Control and Prevention prepared to assist in the U.S. response effort, ORAU provided the CDC with onsite, staff support at its Joint Information Center. ORAU also had a lead role in the development and execution of the CDC's first-ever Bridging the Gaps: Public Health and Radiation Emergency Preparedness conference, which took place 10 days after the earthquake and served as a forum for discussing themore » current state of radiation emergency preparedness.« less

Oestrogen and progesterone action on endometrium: a translational approach to understanding endometrial receptivity

PubMed Central

Young, Steven L.

2013-01-01

Embryo attachment and implantation is critical to successful reproduction of all eutherian mammals, including humans; a better understanding of these processes could lead to improved infertility treatments and novel contraceptive methods. Experience with assisted reproduction, especially oocyte donation cycles, has established that despite the diverse set of hormones produced by the ovary in a cycle-dependent fashion, the sequential actions of only two of them, oestrogen and progesterone, are sufficient to prepare a highly receptive endometrium in humans. Further investigation on the endometrial actions of these two hormones is currently providing significant insight into the implantation process in women, strongly suggesting that an abnormal response to progesterone underlies infertility in some patients. PMID:23933037

Digital barcodes of suspension array using laser induced breakdown spectroscopy

PubMed Central

He, Qinghua; Liu, Yixi; He, Yonghong; Zhu, Liang; Zhang, Yilong; Shen, Zhiyuan

2016-01-01

We show a coding method of suspension array based on the laser induced breakdown spectroscopy (LIBS), which promotes the barcodes from analog to digital. As the foundation of digital optical barcodes, nanocrystals encoded microspheres are prepared with self-assembly encapsulation method. We confirm that digital multiplexing of LIBS-based coding method becomes feasible since the microsphere can be coded with direct read-out data of wavelengths, and the method can avoid fluorescence signal crosstalk between barcodes and analyte tags, which lead to overall advantages in accuracy and stability to current fluorescent multicolor coding method. This demonstration increases the capability of multiplexed detection and accurate filtrating, expanding more extensive applications of suspension array in life science. PMID:27808270

Pediatric drug formulation of sodium benzoate extended-release granules.

PubMed

Combescot, E; Morat, G; de Lonlay, P; Boudy, V

2016-01-01

Urea cycle disorders are a group of inherited orphan diseases leading to hyperammonemia. Current therapeutic strategy includes high doses of sodium benzoate leading to three or four oral intakes per day. As this drug is currently available in capsules or in solution, children are either unable to swallow the capsule or reluctant to take the drug due to its strong bitter taste. The objective of the present study was to develop solid, multiparticulate formulations of sodium benzoate, which are suitable for pediatric patients (i.e. flavor-masked, easy to swallow and with a dosing system). Drug layering and coating in a fluidized bed were applied for preparing sustained-release granules. Two types of inert cores (GalenIQ® and Suglets®) and three different polymers (Kollicoat®, Aquacoat® and Eudragit®) were tested in order to select the most appropriate polymer and starter core for our purpose. Physical characteristics and drug release profiles of the pellets were evaluated. A Suglets® core associated with a Kollicoat® coating seems to be the best combination for an extended release of sodium benzoate. A curing period of 8 h was necessary to complete film formation and the resulting drug release pattern was found to be dependent of the acidity of the release medium.

Facile Synthesis of Layer Structured GeP3/C with Stable Chemical Bonding for Enhanced Lithium-Ion Storage

NASA Astrophysics Data System (ADS)

Qi, Wen; Zhao, Haihua; Wu, Ying; Zeng, Hong; Tao, Tao; Chen, Chao; Kuang, Chunjiang; Zhou, Shaoxiong; Huang, Yunhui

2017-02-01

Recently, metal phosphides have been investigated as potential anode materials because of higher specific capacity compared with those of carbonaceous materials. However, the rapid capacity fade upon cycling leads to poor durability and short cycle life, which cannot meet the need of lithium-ion batteries with high energy density. Herein, we report a layer-structured GeP3/C nanocomposite anode material with high performance prepared by a facial and large-scale ball milling method via in-situ mechanical reaction. The P-O-C bonds are formed in the composite, leading to close contact between GeP3 and carbon. As a result, the GeP3/C anode displays excellent lithium storage performance with a high reversible capacity up to 1109 mA h g-1 after 130 cycles at a current density of 0.1 A g-1. Even at high current densities of 2 and 5 A g-1, the reversible capacities are still as high as 590 and 425 mA h g-1, respectively. This suggests that the GeP3/C composite is promising to achieve high-energy lithium-ion batteries and the mechanical milling is an efficient method to fabricate such composite electrode materials especially for large-scale application.

Applying Value Stream Mapping Technique for Production Improvement in a Manufacturing Company: A Case Study

NASA Astrophysics Data System (ADS)

Jeyaraj, K. L.; Muralidharan, C.; Mahalingam, R.; Deshmukh, S. G.

2013-01-01

The purpose of this paper is to explain how value stream mapping (VSM) is helpful in lean implementation and to develop the road map to tackle improvement areas to bridge the gap between the existing state and the proposed state of a manufacturing firm. Through this case study, the existing stage of manufacturing is mapped with the help of VSM process symbols and the biggest improvement areas like excessive TAKT time, production, and lead time are identified. Some modifications in current state map are suggested and with these modifications future state map is prepared. Further TAKT time is calculated to set the pace of production processes. This paper compares the current state and future state of a manufacturing firm and witnessed 20 % reduction in TAKT time, 22.5 % reduction in processing time, 4.8 % reduction in lead time, 20 % improvement in production, 9 % improvement in machine utilization, 7 % improvement in man power utilization, objective improvement in workers skill level, and no change in the product and semi finished product inventory level. The findings are limited due to the focused nature of the case study. This case study shows that VSM is a powerful tool for lean implementation and allows the industry to understand and continuously improve towards lean manufacturing.

Evaluation of the Fretting Resistance of the High Voltage Insulation on the ITER Magnet Feeder Busbars

NASA Astrophysics Data System (ADS)

Clayton, N.; Crouchen, M.; Evans, D.; Gung, C.-Y.; Su, M.; Devred, A.; Piccin, R.

2017-12-01

The high voltage (HV) insulation on the ITER magnet feeder superconducting busbars and current leads will be prepared from S-glass fabric, pre-impregnated with an epoxy resin, which is interleaved with polyimide film and wrapped onto the components and cured during feeder manufacture. The insulation architecture consists of nine half-lapped layers of glass/Kapton, which is then enveloped in a ground-screen, and two further half-lapped layers of glass pre-preg for mechanical protection. The integrity of the HV insulation is critical in order to inhibit electrical arcs within the feeders. The insulation over the entire length of the HV components (bus bar, current leads and joints) must provide a level of voltage isolation of 30 kV. In operation, the insulation on ITER busbars will be subjected to high mechanical loads, arising from Lorentz forces, and in addition will be subjected to fretting erosion against stainless steel clamps, as the pulsed nature of some magnets results in longitudinal movement of the busbar. This work was aimed at assessing the wear on, and the changes in, the electrical properties of the insulation when subjected to typical ITER operating conditions. High voltage tests demonstrated that the electrical isolation of the insulation was intact after the fretting test.

Career Preparation: A Longitudinal, Process-Oriented Examination

PubMed Central

Stringer, Kate; Kerpelman, Jennifer; Skorikov, Vladimir

2011-01-01

Preparing for an adult career through careful planning, choosing a career, and gaining confidence to achieve career goals is a primary task during adolescence and early adulthood. The current study bridged identity process literature and career construction theory (Savickas, 2005) by examining the commitment component of career adaptability, career preparation (i.e., career planning, career decision-making, and career confidence), from an identity process perspective (Luyckx, Goossens, & Soenens, 2006). Research has suggested that career preparation dimensions are interrelated during adolescence and early adulthood; however, what remains to be known is how each dimension changes over time and the interrelationships among the dimensions during the transition from high school. Drawing parallels between career preparation and identity development dimensions, the current study addressed these questions by examining the patterns of change in each career preparation dimension and parallel process models that tested associations among the slopes and intercepts of the career preparation dimensions. Results showed that the career preparation dimensions were not developing similarly over time, although each dimension was associated cross-sectionally and longitudinally with the other dimensions. Results also suggested that career planning and decision-making precede career confidence. The results of the current study supported career construction theory and showed similarities between the processes of career preparation and identity development. PMID:21804641

Career Preparation: A Longitudinal, Process-Oriented Examination.

PubMed

Stringer, Kate; Kerpelman, Jennifer; Skorikov, Vladimir

2011-08-01

Preparing for an adult career through careful planning, choosing a career, and gaining confidence to achieve career goals is a primary task during adolescence and early adulthood. The current study bridged identity process literature and career construction theory (Savickas, 2005) by examining the commitment component of career adaptability, career preparation (i.e., career planning, career decision-making, and career confidence), from an identity process perspective (Luyckx, Goossens, & Soenens, 2006). Research has suggested that career preparation dimensions are interrelated during adolescence and early adulthood; however, what remains to be known is how each dimension changes over time and the interrelationships among the dimensions during the transition from high school. Drawing parallels between career preparation and identity development dimensions, the current study addressed these questions by examining the patterns of change in each career preparation dimension and parallel process models that tested associations among the slopes and intercepts of the career preparation dimensions. Results showed that the career preparation dimensions were not developing similarly over time, although each dimension was associated cross-sectionally and longitudinally with the other dimensions. Results also suggested that career planning and decision-making precede career confidence. The results of the current study supported career construction theory and showed similarities between the processes of career preparation and identity development.

Toward Achievement in the "Knowledge Economy" of the 21st Century: Preparing Students through T-STEM Academies

ERIC Educational Resources Information Center

Gonzales, Alberto

2010-01-01

Schools are constantly engaged in implementing reform strategies to prepare students for post-secondary education leading to their career choices. Challenges here involve education initiatives addressing programs not strategically planned, educators not prepared for transition, and no follow-up support beyond initial implementation stages. This…

Toward Achievement in the "Knowledge Economy" of the 21st Century: Preparing Students through T-STEM Academies

ERIC Educational Resources Information Center

Gonzales, Alberto; Jones, Don; Ruiz, Alberto

2014-01-01

Schools are constantly engaged in implementing reform strategies to prepare students for postsecondary education leading to their career choices. Challenges here involve education initiatives addressing programs not strategically planned, educators not prepared for transition, and no follow-up support beyond initial implementation stages. This…

Pilocarpine-Induced Status Epilepticus Increases the Sensitivity of P2X7 and P2Y1 Receptors to Nucleotides at Neural Progenitor Cells of the Juvenile Rodent Hippocampus.

PubMed

Rozmer, Katalin; Gao, Po; Araújo, Michelle G L; Khan, Muhammad Tahir; Liu, Juan; Rong, Weifang; Tang, Yong; Franke, Heike; Krügel, Ute; Fernandes, Maria José S; Illes, Peter

2017-07-01

Patch-clamp recordings indicated the presence of P2X7 receptors at neural progenitor cells (NPCs) in the subgranular zone of the dentate gyrus in hippocampal brain slices prepared from transgenic nestin reporter mice. The activation of these receptors caused inward current near the resting membrane potential of the NPCs, while P2Y1 receptor activation initiated outward current near the reversal potential of the P2X7 receptor current. Both receptors were identified by biophysical/pharmacological methods. When the brain slices were prepared from mice which underwent a pilocarpine-induced status epilepticus or when brain slices were incubated in pilocarpine-containing external medium, the sensitivity of P2X7 and P2Y1 receptors was invariably increased. Confocal microscopy confirmed the localization of P2X7 and P2Y1 receptor-immunopositivity at nestin-positive NPCs. A one-time status epilepticus in rats caused after a latency of about 5 days recurrent epileptic fits. The blockade of central P2X7 receptors increased the number of seizures and their severity. It is hypothesized that P2Y1 receptors after a status epilepticus may increase the ATP-induced proliferation/ectopic migration of NPCs; the P2X7 receptor-mediated necrosis/apoptosis might counteract these effects, which would otherwise lead to a chronic manifestation of recurrent epileptic fits. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Hybrid zinc oxide/graphene electrodes for depleted heterojunction colloidal quantum-dot solar cells.

PubMed

Tavakoli, Mohammad Mahdi; Aashuri, Hossein; Simchi, Abdolreza; Fan, Zhiyong

2015-10-07

Recently, hybrid nanocomposites consisting of graphene/nanomaterial heterostructures have emerged as promising candidates for the fabrication of optoelectronic devices. In this work, we have employed a facile and in situ solution-based process to prepare zinc oxide/graphene quantum dots (ZnO/G QDs) in a hybrid structure. The prepared hybrid dots are composed of a ZnO core, with an average size of 5 nm, warped with graphene nanosheets. Spectroscopic studies show that the graphene shell quenches the photoluminescence intensity of the ZnO nanocrystals by about 72%, primarily due to charge transfer reactions and static quenching. A red shift in the absorption peak is also observed. Raman spectroscopy determines G-band splitting of the graphene shell into two separated sub-bands (G(+), G(-)) caused by the strain induced symmetry breaking. It is shown that the hybrid ZnO/G QDs can be used as a counter-electrode for heterojunction colloidal quantum-dot solar cells for efficient charge-carrier collection, as evidenced by the external quantum efficiency measurement. Under the solar simulated spectrum (AM 1.5G), we report enhanced power conversion efficiency (35%) with higher short current circuit (80%) for lead sulfide-based solar cells as compared to devices prepared by pristine ZnO nanocrystals.

Identification of an exposure risk to heavy metals from pharmaceutical-grade rubber stoppers.

PubMed

Li, Xianghui; Qian, Pingping

2017-07-01

Exposure to low concentrations of heavy metals and metalloids represents a well-documented risk to animal and human health. However, current standards (European Pharmacopeia [EP], United States Pharmacopoeia [USP], International Organization for Standardization [ISO], YBB concerned with rubber closures) only require testing for Zn in pharmaceutical-grade rubber stoppers and then using only pure water as a solvent. We extracted and quantified heavy metals and trace elements from pharmaceutical-grade rubber stoppers under conditions that might occur during the preparation of drugs. Pure water, saline, 10% glucose, 3% acetic acid (w/v), 0.1 mol/L hydrochloric acid, and diethylenetriaminepentaacetic acid (4 mg/mL, 0.4 mg/mL, and 0.04 mg/mL) were used as extraction agents. We quantified the extracted arsenic, lead, antimony, iron, magnesium, aluminum, and zinc using inductively coupled plasma mass spectrometry. The concentration of extracted metals varied depending on the different extraction solutions used and between the different rubber stopper manufacturers. Rubber stoppers are ubiquitously used in the pharmaceutical industry for the storage and preparation of drugs. Extraction of heavy metals during the manufacturing and preparation of drugs represents a significant risk, suggesting a need for industry standards to focus on heavy metal migration from rubber stoppers. Copyright © 2016. Published by Elsevier B.V.

The Successful Diagnosis and Typing of Systemic Amyloidosis Using A Microwave-Assisted Filter-Aided Fast Sample Preparation Method and LC/MS/MS Analysis

PubMed Central

Zou, Lili; Shen, Kaini; Zhong, Dingrong; Zhou, Daobin; Sun, Wei; Li, Jian

2015-01-01

Laser microdissection followed by mass spectrometry has been successfully used for amyloid typing. However, sample contamination can interfere with proteomic analysis, and overnight digestion limits the analytical throughput. Moreover, current quantitative analysis methods are based on the spectrum count, which ignores differences in protein length and may lead to misdiagnoses. Here, we developed a microwave-assisted filter-aided sample preparation (maFASP) method that can efficiently remove contaminants with a 10-kDa cutoff ultrafiltration unit and can accelerate the digestion process with the assistance of a microwave. Additionally, two parameters (P- and D-scores) based on the exponentially modified protein abundance index were developed to define the existence of amyloid deposits and those causative proteins with the greatest abundance. Using our protocol, twenty cases of systemic amyloidosis that were well-typed according to clinical diagnostic standards (training group) and another twenty-four cases without subtype diagnoses (validation group) were analyzed. Using this approach, sample preparation could be completed within four hours. We successfully subtyped 100% of the cases in the training group, and the diagnostic success rate in the validation group was 91.7%. This maFASP-aided proteomic protocol represents an efficient approach for amyloid diagnosis and subtyping, particularly for serum-contaminated samples. PMID:25984759

Food safety labelling of chicken to prevent campylobacteriosis: consumer expectations and current practices.

PubMed

Allan, Philip D; Palmer, Chloe; Chan, Fiona; Lyons, Rebecca; Nicholson, Olivia; Rose, Mitchell; Hales, Simon; Baker, Michael G

2018-03-27

Campylobacter is the leading cause of bacterial gastroenteritis worldwide, and contaminated chicken is a significant vehicle for spread of the disease. This study aimed to assess consumers' knowledge of safe chicken handling practices and whether their expectations for food safety labelling of chicken are met, as a strategy to prevent campylobacteriosis. We conducted a cross-sectional survey of 401 shoppers at supermarkets and butcheries in Wellington, New Zealand, and a systematic assessment of content and display features of chicken labels. While 89% of participants bought, prepared or cooked chicken, only 15% knew that most (60-90%) fresh chicken in New Zealand is contaminated by Campylobacter. Safety and correct preparation information on chicken labels, was rated 'very necessary' or 'essential' by the majority of respondents. Supermarket chicken labels scored poorly for the quality of their food safety information with an average of 1.7/5 (95% CI, 1.4-2.1) for content and 1.8/5 (95% CI, 1.6-2.0) for display. Most consumers are unaware of the level of Campylobacter contamination on fresh chicken and there is a significant but unmet consumer demand for information on safe chicken preparation on labels. Labels on fresh chicken products are a potentially valuable but underused tool for campylobacteriosis prevention in New Zealand.

A novel sputtered Pd mesh architecture as an advanced electrocatalyst for highly efficient hydrogen production

NASA Astrophysics Data System (ADS)

de Lucas-Consuegra, Antonio; de la Osa, Ana R.; Calcerrada, Ana B.; Linares, José J.; Horwat, David

2016-07-01

This study reports the preparation, characterization and testing of a sputtered Pd mesh-like anode as an advanced electrocatalyst for H2 production from alkaline ethanol solutions in an Alkaline Membrane Electrolyzer (AEM). Pd anodic catalyst is prepared by magnetron sputtering technique onto a microfiber carbon paper support. Scanning Electron Microscopy images reveal that the used preparation technique enables to cover the surface of the carbon microfibers exposed to the Pd target, leading to a continuous network that also maintains part of the original carbon paper macroporosity. Such novel anodic architecture (organic binder free) presents an excellent electro-chemical performance, with a maximum current density of 700 mA cm-2 at 1.3 V, and, concomitantly, a large H2 production rate with low energy requirement compared to water electrolysis. Potassium hydroxide emerges as the best electrolyte, whereas temperature exerts the expected promotional effect up to 90 °C. On the other hand, a 1 mol L-1 ethanol solution is enough to guarantee an efficient fuel supply without any mass transfer limitation. The proposed system also demonstrates to remain stable over 150 h of operation along five consecutives cycles, producing highly pure H2 (99.999%) at the cathode and potassium acetate as the main anodic product.

A Universal Strategy To Prepare Sulfur-Containing Polymer Composites with Desired Morphologies for Lithium-Sulfur Batteries.

PubMed

Zeng, Shao-Zhong; Zeng, Xierong; Tu, Wenxuan; Huang, Haitao; Yu, Liang; Yao, Yuechao; Jin, Nengzhi; Zhang, Qi; Zou, Jizhao

2018-06-19

Lithium-sulfur (Li-S) batteries are probably the most promising candidates for the next-generation batteries owing to their high energy density. However, Li-S batteries face severe technical problems where the dissolution of intermediate polysulfides is the biggest problem because it leads to the degradation of the cathode and the lithium anode, and finally the fast capacity decay. Compared with the composites of elemental sulfur and other matrices, sulfur-containing polymers (SCPs) have strong chemical bonds to sulfur and therefore show low dissolution of polysulfides. Unfortunately, most SCPs have very low electron conductivity and their morphologies can hardly be controlled, which undoubtedly depress the battery performances of SCPs. To overcome these two weaknesses of SCPs, a new strategy was developed for preparing SCP composites with enhanced conductivity and desired morphologies. With this strategy, macroporous SCP composites were successfully prepared from hierarchical porous carbon. The composites displayed discharge/charge capacities up to 1218/1139, 949/922, and 796/785 mA h g -1 at the current rates of 5, 10, and 15 C, respectively. Considering the universality of this strategy and the numerous morphologies of carbon materials, this strategy opens many opportunities for making carbon/SCP composites with novel morphologies.

PdNi- and Pd-coated electrodes prepared by electrodeposition from ionic liquid for nonenzymatic electrochemical determination of ethanol and glucose in alkaline media.

PubMed

Huang, Hsin-Yi; Chen, Po-Yu

2010-12-15

Nonenzymatic electrochemical determination of ethanol and glucose was respectively achieved using PdNi- and Pd-coated electrodes prepared by electrodeposition from the novel metal-free ionic liquid (IL); N-butyl-N-methylpyrrolidinium dicyanamide (BMP-DCA). BMP-DCA provided an excellent environment and wide cathodic limit for electrodeposition of metals and alloys because many metal chlorides could dissolve in this IL where the reduction potentials of Pd(II) and Ni(II) indeed overlapped, leading to the convenience of potentiostatic codeposition. In aqueous solutions, the reduction potentials of Pd(II) and Ni(II) are considerably separated. The bimetallic PdNi coatings with atomic ratios of ∼ 80/20 showed the highest current for ethanol oxidation reaction (EOR). Ethanol was detected by either cyclic voltammetry (CV) or hydrodynamic amperometry (HA). Using CV, the dependence of EOR peak current on concentration was linear from 4.92 to 962 μM with a detection limit of 2.26 μM (σ=3), and a linearity was observed from 4.92 to 988 μM using HA (detection limit 0.83 μM (σ=3)). The Pd-coated electrodes prepared by electrodeposition from BMP-DCA showed electrocatalytic activity to glucose oxidation and CV, HA, and square-wave voltammetry (SWV) were employed to determine glucose. SWV showed the best sensitivity and linearity was observed from 2.86 μM to 107 μM, and from 2.99 mM to 10.88 mM with detection limits of 0.78 μM and 25.9 μM (σ=3), respectively. For glucose detection, the interference produced from ascorbic acid, uric acid, and acetaminophen was significantly suppressed, compared with a regular Pt disk electrode. Copyright © 2010 Elsevier B.V. All rights reserved.

Vapor cooled current lead for cryogenic electrical equipment

DOEpatents

Vansant, James H.

1983-01-01

Apparatus and method are provided for conducting electric current to cryogenic electrical equipment devices. A combination of inner and outer tubes together form a plurality of hollow composite tubes housed in a sheath. Top and bottom block mounting means are fitted to hold the composite tubes and are affixed to the ends of the sheath. This combination forms a current lead. The current lead is attached to a cryogenic device housing a fluid coolant which moves through the current lead, cooling the current lead as the fluid travels.

Method development and subsequent survey analysis of biological tissues for platinum, lead, and manganese content.

PubMed Central

Yoakum, A M; Stewart, P L; Sterrett, J E

1975-01-01

An emission spectrochemical method is described for the determination of trace quantities of platinum, lead, and manganese in biological tissues. Total energy burns in an argon-oxygen atmosphere are employed. Sample preparation, conditions of analysis, and preparation of standards are discussed. The precision of the method is consistently better than +/- 15%, and comparative analyses indicate comparable accuracies. Data obtained for experimental rat tissues and for selected autopsy tissues are presented. PMID:1157798

23 CFR 771.123 - Draft environmental impact statements.

Code of Federal Regulations, 2011 CFR

2011-04-01

... Notice of Intent, the lead agencies, in cooperation with the applicant (if not a lead agency), will begin... at the local level. (c) The draft EIS shall be prepared by the lead agencies, in cooperation with the applicant (if not a lead agency). The draft EIS shall evaluate all reasonable alternatives to the action and...

23 CFR 771.123 - Draft environmental impact statements.

Code of Federal Regulations, 2010 CFR

2010-04-01

... Notice of Intent, the lead agencies, in cooperation with the applicant (if not a lead agency), will begin... at the local level. (c) The draft EIS shall be prepared by the lead agencies, in cooperation with the applicant (if not a lead agency). The draft EIS shall evaluate all reasonable alternatives to the action and...

A cognitive behavioral course for at-risk senior nursing students preparing to take the NCLEX.

PubMed

Poorman, Susan G; Mastorovich, Melissa L; Liberto, Terri L; Gerwick, Michele

2010-01-01

For some nursing students, the stress of preparing for and taking the NCLEX can lead to maladaptive behaviors such as poor test performance and inadequate preparation. A different approach to NCLEX preparation for at-risk seniors is described. A 3-credit course that combines cognitive behavioral techniques, metacognitive strategies, test-taking strategies, and simulated NCLEX experience with practice questions is presented. Students also develop an individualized plan of preparation from graduation until they take the NCLEX.

Characterization of perovskite solar cells: Towards a reliable measurement protocol

NASA Astrophysics Data System (ADS)

Zimmermann, Eugen; Wong, Ka Kan; Müller, Michael; Hu, Hao; Ehrenreich, Philipp; Kohlstädt, Markus; Würfel, Uli; Mastroianni, Simone; Mathiazhagan, Gayathri; Hinsch, Andreas; Gujar, Tanaji P.; Thelakkat, Mukundan; Pfadler, Thomas; Schmidt-Mende, Lukas

2016-09-01

Lead halide perovskite solar cells have shown a tremendous rise in power conversion efficiency with reported record efficiencies of over 20% making this material very promising as a low cost alternative to conventional inorganic solar cells. However, due to a differently severe "hysteretic" behaviour during current density-voltage measurements, which strongly depends on scan rate, device and measurement history, preparation method, device architecture, etc., commonly used solar cell measurements do not give reliable or even reproducible results. For the aspect of commercialization and the possibility to compare results of different devices among different laboratories, it is necessary to establish a measurement protocol which gives reproducible results. Therefore, we compare device characteristics derived from standard current density-voltage measurements with stabilized values obtained from an adaptive tracking of the maximum power point and the open circuit voltage as well as characteristics extracted from time resolved current density-voltage measurements. Our results provide insight into the challenges of a correct determination of device performance and propose a measurement protocol for a reliable characterisation which is easy to implement and has been tested on varying perovskite solar cells fabricated in different laboratories.

Microfluidic approaches to malaria detection

PubMed Central

Gascoyne, Peter; Satayavivad, Jutamaad; Ruchirawat, Mathuros

2009-01-01

Microfluidic systems are under development to address a variety of medical problems. Key advantages of micrototal analysis systems based on microfluidic technology are the promise of small size and the integration of sample handling and measurement functions within a single, automated device having low mass-production costs. Here, we review the spectrum of methods currently used to detect malaria, consider their advantages and disadvantages, and discuss their adaptability towards integration into small, automated micro total analysis systems. Molecular amplification methods emerge as leading candidates for chip-based systems because they offer extremely high sensitivity, the ability to recognize malaria species and strain, and they will be adaptable to the detection of new genotypic signatures that will emerge from current genomic-based research of the disease. Current approaches to the development of chip-based molecular amplification are considered with special emphasis on flow-through PCR, and we present for the first time the method of malaria specimen preparation by dielectrophoretic field-flow-fractionation. Although many challenges must be addressed to realize a micrototal analysis system for malaria diagnosis, it is concluded that the potential benefits of the approach are well worth pursuing. PMID:14744562

Could a revision of the current guidelines for cancer drug use improve the quality of cancer treatment?

PubMed

Lippert, Theodor H; Ruoff, Hans-Jörg; Volm, Manfred

2014-01-01

Clinical practice guidelines are indispensable for such a variable disease as malignant solid tumors, with the complex possibilities of drug treatment. The current guidelines may be criticized on several points, however. First, there is a lack of information on the outcome of treatment, such as the expected success and failure rates. Treating not only drug responders but also nonresponders, that is, patients with drug resistance, must result in failures. There is no mention of the possibility of excluding the drug nonresponders, identifiable by special laboratory tests and no consideration is given to the different side effects of the recommended drug regimens. Nor are there any instructions concerning tumor cases for which anticancer drug treatment is futile. In such cases, early palliative care may lead to significant improvements in both life quality and life expectancy. Not least, there is no transparency concerning the preparation of the guidelines: persons cannot be identified who could give a statement of conflicts of interest, and responsibility is assumed only by anonymous medical associations. A revision of the current guidelines could considerably improve cancer treatment.

Effect of corona discharge on cadmium sulphide and lead sulphide films

NASA Astrophysics Data System (ADS)

Koul Chaku, Anemone; Singh, Pramod K.; Bhattacharya, Bhaskar

2018-03-01

This paper describes the effect of corona discharge on cadmium sulphide (CdS) and lead sulphide (PbS) films prepared using the chemical route. The property of films before and after exposure to corona has been described in detail. The electronic properties of the CdS and PbS films have been studied by current-voltage (I-V), capacitance-voltage (C-V) measurements. The structural properties and surface morphology were studied by using X-ray diffraction and scanning electron microscopy before and after exposing to Corona discharge. The films displayed the change in surface morphology after exposure to the corona discharge. It has been found that the films showed an increase in resistivity after exposure. This change in property has been attributed to modification in surface states. Time-dependent recovery indicated that room temperature annealing is sufficient to regain the normal resistivity of the films. The experiment was carried with the aim of studying the effect of the interaction of corona discharge on the semiconductor films and its subsequent effects.

Strengthening Moral Courage Among Nurse Leaders.

PubMed

Edmonson, Cole

2015-02-17

Moral distress among practicing nurses is frequently discussed in the nursing literature, along with well-developed recommendations for increasing moral courage in practicing nurses. Implementing these recommendations depends on nurse leaders being morally fit to lead and to create an environment in which moral courage actions can emerge. The literature is lacking pertaining to nurse leaders' preparation to lead in a morally courageous and transformational manner in our current corporate environments and hierarchies of healthcare. In this article, the author reviews the literature addressing moral distress and moral courage among direct care nurses; describes the development of an intervention to strengthen the moral courage of nurse leaders; reports a study that involved implementing this intervention; presents the findings of this study; evaluates the effectiveness of the intervention; and discusses the findings in terms of lessons learned and future directions. He concludes with a call for healthcare leaders to demonstrate moral courage and create environments that promote morally courageous acts that enable nurses to remain centered on the patients, families, and communities we serve.

Inhibition of HIV-1 Replication by Secondary Metabolites From Endophytic Fungi of Desert Plants

PubMed Central

Wellensiek, Brian P.; Ramakrishnan, Rajesh; Bashyal, Bharat P.; Eason, Yvette; Gunatilaka, A. A. Leslie; Ahmad, Nafees

2013-01-01

Most antiretroviral drugs currently in use to treat an HIV-1 infection are chemically synthesized and lead to the development of viral resistance, as well as cause severe toxicities. However, a largely unexplored source for HIV-1 drug discovery is endophytic fungi that live in a symbiotic relationship with plants. These fungi produce biologically active secondary metabolites, which are natural products that are beneficial to the host. We prepared several hundred extracts from endophytic fungi of desert plants and evaluated the inhibitory effects on HIV-1 replication of those extracts that showed less than 30% cytotoxicity in T-lymphocytes. Those extracts that inhibited viral replication were fractionated in order to isolate the compounds responsible for activity. Multiple rounds of fractionation and antiviral evaluation lead to the identification of four compounds, which almost completely impede HIV-1 replication. These studies demonstrate that metabolites from endophytic fungi of desert plants can serve as a viable source for identifying potent inhibitors of HIV-1 replication. PMID:23961302

FY 1986 current fiscal year work plan

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

Not Available

This Current Year Work Plan presents in detail a description of the activities to be performed by the Joint Integration Office/RI during FY86. It breaks down the activities into two major work areas: Program Management and Program Analysis. Program Management is performed by the JIO/RI by providing technical planning and guidance for the development of advanced TRU waste management capabilities. This includes equipment/facility design, engineering, construction, and operations. These functions are integrated to allow transition from interim storage to final disposition. JIO/RI tasks include program requirements identification, long-range technical planning, budget development, program planning document preparation, task guidance development, taskmore » monitoring, task progress information gathering and reporting to DOE, interfacing with other agencies and DOE lead programs, integrating public involvement with program efforts, and preparation of reports for DOE detailing program status. Program Analysis is performed by the JIO/RI to support identification and assessment of alternatives, and development of long-term TRU waste program capabilities. These analyses include short term analyses in response to DOE information requests, along with performing an RH Cost/Schedule Optimization report. System models will be developed, updated, and upgraded as needed to enhance JIO/RI's capability to evaluate the adequacy of program efforts in various fields. A TRU program data base will be maintained and updated to provide DOE with timely responses to inventory related questions.« less

One-step fabrication of an organ-on-a-chip with spatial heterogeneity using a 3D bioprinting technology.

PubMed

Lee, Hyungseok; Cho, Dong-Woo

2016-07-05

Although various types of organs-on-chips have been introduced recently as tools for drug discovery, the current studies are limited in terms of fabrication methods. The fabrication methods currently available not only need a secondary cell-seeding process and result in severe protein absorption due to the material used, but also have difficulties in providing various cell types and extracellular matrix (ECM) environments for spatial heterogeneity in the organs-on-chips. Therefore, in this research, we introduce a novel 3D bioprinting method for organ-on-a-chip applications. With our novel 3D bioprinting method, it was possible to prepare an organ-on-a-chip in a simple one-step fabrication process. Furthermore, protein absorption on the printed platform was very low, which will lead to accurate measurement of metabolism and drug sensitivity. Moreover, heterotypic cell types and biomaterials were successfully used and positioned at the desired position for various organ-on-a-chip applications, which will promote full mimicry of the natural conditions of the organs. The liver organ was selected for the evaluation of the developed method, and liver function was shown to be significantly enhanced on the liver-on-a-chip, which was prepared by 3D bioprinting. Consequently, the results demonstrate that the suggested 3D bioprinting method is easier and more versatile for production of organs-on-chips.

Effects of calcination temperature for rate capability of triple-shelled ZnFe2O4 hollow microspheres for lithium ion battery anodes

NASA Astrophysics Data System (ADS)

Hwang, Hojin; Shin, Haeun; Lee, Wan-Jin

2017-04-01

Triple-shelled ZnFe2O4 hollow microspheres (ZFO) as anode materials for lithium ion battery are prepared through a one-pot hydrothermal reaction using the composite solution consisting of sucrose in water and metal ions in ethylene glycol (EG), followed by different calcination processes. The architectures of ZFO micro spheres are differently synthesized through a mutual cooperation of inward and outward ripening with three different calcination temperatures. Thin triple-shelled ZnFe2O4 hollow microspheres calcined at 450 °C (ZFO-450) delivers a high reversible capacity of 932 mA h g-1 at a current density of 2 A g-1 even at the 200th cycle without obvious decay. Furthermore, ZFO-450 delivers 1235, 1005, 865, 834, and 845 mA h g-1 at high current densities of 0.5, 2, 5, 10, and 20 A g-1 after 100 cycles. Thin triple-shelled hollow microsphere prepared at an optimum calcination temperature provides exceptional rate capability and outstanding rate retention due to (i) the formation of nanoparticles leading to thin shell with morphological integrity, (ii) the facile mass transfer by thin shell with mesoporous structure, and (iii) the void space with macroporous structure alleviating volume change occurring during cycling.

Effects of calcination temperature for rate capability of triple-shelled ZnFe2O4 hollow microspheres for lithium ion battery anodes

PubMed Central

Hwang, Hojin; Shin, Haeun; Lee, Wan-Jin

2017-01-01

Triple-shelled ZnFe2O4 hollow microspheres (ZFO) as anode materials for lithium ion battery are prepared through a one-pot hydrothermal reaction using the composite solution consisting of sucrose in water and metal ions in ethylene glycol (EG), followed by different calcination processes. The architectures of ZFO micro spheres are differently synthesized through a mutual cooperation of inward and outward ripening with three different calcination temperatures. Thin triple-shelled ZnFe2O4 hollow microspheres calcined at 450 °C (ZFO-450) delivers a high reversible capacity of 932 mA h g−1 at a current density of 2 A g−1 even at the 200th cycle without obvious decay. Furthermore, ZFO-450 delivers 1235, 1005, 865, 834, and 845 mA h g−1 at high current densities of 0.5, 2, 5, 10, and 20 A g−1 after 100 cycles. Thin triple-shelled hollow microsphere prepared at an optimum calcination temperature provides exceptional rate capability and outstanding rate retention due to (i) the formation of nanoparticles leading to thin shell with morphological integrity, (ii) the facile mass transfer by thin shell with mesoporous structure, and (iii) the void space with macroporous structure alleviating volume change occurring during cycling. PMID:28418001

Preparation and Characterization of Niobium Doped Lead-Telluride Glass Ceramics

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

Sathish, M.; Eraiah, B.; Anavekar, R. V.

2011-07-15

Niobium-lead-telluride glass ceramics of composition xNb{sub 2}O{sub 5}-(20-x) pbO-80TeO{sub 2}(where x = 0.1 mol% to 0.5 mol%) were prepared by using conventional melt quenching method. The prepared glass samples were initially amorphous in nature after annealed at 400 deg. c all samples were crystallized. This was confined by X-ray diffraction and scanning electron microscopy. The particle size of these glass ceramics have been calculated by using Debye-Scherer formula and the particle size is in the order of 15 nm to 60 nm. The scanning electron microscopy (SEM) photograph shows the presence of needle-like crystals in these samples.

Transcriptional Profiling of Metabolic Transitions during Development and Diapause Preparation in the Copepod Calanus finmarchicus.

PubMed

Tarrant, Ann M; Baumgartner, Mark F; Lysiak, Nadine S J; Altin, Dag; Størseth, Trond R; Hansen, Bjørn Henrik

2016-12-01

Calanus finmarchicus, like many other copepods in the family Calanidae, can enter into a facultative diapause during the last juvenile phase (fifth copepodid, C5) to enable survival during unfavorable periods. Diapause is essential to the persistence of Calanus populations and profoundly impacts energy flow within oceanic ecosystems, yet regulation of diapause is not understood in these animals. Transcriptional profiling has begun to provide insight into metabolic changes occurring as C. finmarchicus prepares for and enters into diapause or skips diapause to prepare for the terminal molt. In particular, components of the glycolysis, pentose phosphate and lipid synthesis pathways are upregulated early in the C5 stage when lipid stores are low. Currently, our ability to identify metabolic patterns is limited by the incomplete functional annotation of the C. finmarchicus transcriptome. Such limitations are widespread among studies of non-model organisms and addressing them should be a priority for future research. In addition, integrating the results across multiple emerging complementary transcriptomic studies will provide a more complete picture of copepod physiology than isolated studies. Ultimately, identifying molecular markers of copepod physiology could enable robust identification of animals preparing to enter into diapause and ultimately lead to a greatly improved understanding of diapause regulation. © The Author 2016. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

Quantitation of next generation sequencing library preparation protocol efficiencies using droplet digital PCR assays - a systematic comparison of DNA library preparation kits for Illumina sequencing.

PubMed

Aigrain, Louise; Gu, Yong; Quail, Michael A

2016-06-13

The emergence of next-generation sequencing (NGS) technologies in the past decade has allowed the democratization of DNA sequencing both in terms of price per sequenced bases and ease to produce DNA libraries. When it comes to preparing DNA sequencing libraries for Illumina, the current market leader, a plethora of kits are available and it can be difficult for the users to determine which kit is the most appropriate and efficient for their applications; the main concerns being not only cost but also minimal bias, yield and time efficiency. We compared 9 commercially available library preparation kits in a systematic manner using the same DNA sample by probing the amount of DNA remaining after each protocol steps using a new droplet digital PCR (ddPCR) assay. This method allows the precise quantification of fragments bearing either adaptors or P5/P7 sequences on both ends just after ligation or PCR enrichment. We also investigated the potential influence of DNA input and DNA fragment size on the final library preparation efficiency. The overall library preparations efficiencies of the libraries show important variations between the different kits with the ones combining several steps into a single one exhibiting some final yields 4 to 7 times higher than the other kits. Detailed ddPCR data also reveal that the adaptor ligation yield itself varies by more than a factor of 10 between kits, certain ligation efficiencies being so low that it could impair the original library complexity and impoverish the sequencing results. When a PCR enrichment step is necessary, lower adaptor-ligated DNA inputs leads to greater amplification yields, hiding the latent disparity between kits. We describe a ddPCR assay that allows us to probe the efficiency of the most critical step in the library preparation, ligation, and to draw conclusion on which kits is more likely to preserve the sample heterogeneity and reduce the need of amplification.

Lead acetate trihydrate precursor route to synthesize novel ultrafine lead oxide from spent lead acid battery pastes

NASA Astrophysics Data System (ADS)

Sun, Xiaojuan; Yang, Jiakuan; Zhang, Wei; Zhu, Xinfeng; Hu, Yuchen; Yang, Danni; Yuan, Xiqing; Yu, Wenhao; Dong, Jinxin; Wang, Haifeng; Li, Lei; Vasant Kumar, R.; Liang, Sha

2014-12-01

A novel green recycling process is investigated to prepare lead acetate trihydrate precursors and novel ultrafine lead oxide from spent lead acid battery pastes. The route contains the following four processes. (1) The spent lead pastes are desulphurized by (NH4)2CO3. (2) The desulphurized pastes are converted into lead acetate solution by leaching with acetic acid solution and H2O2; (3) The Pb(CH3COO)2·3H2O precursor is crystallized and purified from the lead acetate solution with the addition of glacial acetic acid; (4) The novel ultrafine lead oxide is prepared by the calcination of lead acetate trihydrate precursor in N2 or air at 320-400 °C. Both the lead acetate trihydrate and lead oxide products are characterized by TG-DTA, XRD, and SEM techniques. The calcination products are mainly α-PbO, β-PbO, and a small amount of metallic Pb. The particle size of the calcination products in air is significantly larger than that in N2. Cyclic voltammetry measurements of the novel ultrafine lead oxide products show good reversibility and cycle stability. The assembled batteries using the lead oxide products as cathode active materials show a good cyclic stability in 80 charge/discharge cycles with the depth of discharge (DOD) of 100%.

Technical Preparation: Preparing Students for Success. A Position Paper Presented by the Wisconsin Association of Secondary Vocational Administrators 1991-1992.

ERIC Educational Resources Information Center

Peterson, Charlene; And Others

Technical Preparation (Tech Prep) programs include basic skills and competencies to improve students' school-to-work transition. The following elements characterize Tech Prep: designed for grades 9-14, leading to an technical associate degree; parallels college preparatory program; offers technical program of study in business enterprise,…

75 FR 27053 - Environmental Impact Statement: Multiple Counties, New York, and New Jersey

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-13

... additional data in preparation for Tier II analyses and preliminary design. Tier I of the EIS will result in... providing economic benefits. The FHWA and PANYNJ are serving as joint-lead agencies for the preparation of... for the preparation of the EIS. The EIS analyses will be conducted using ``tiering,'' as described in...

Ultra-Low Heat-Leak, High-Temperature Superconducting Current Leads for Space Applications

NASA Technical Reports Server (NTRS)

Rey, Christopher M.

2013-01-01

NASA Goddard Space Flight Center has a need for current leads used in an adiabatic demagnetization refrigerator (ADR) for space applications. These leads must comply with stringent requirements such as a heat leak of approximately 100 W or less while conducting up to 10 A of electric current, from more than 90 K down to 10 K. Additionally, a length constraint of < 300 mm length and < 50 mm diameter is to be maintained. The need for these current leads was addressed by developing a superconducting hybrid lead. This hybrid lead comprises two different high-temperature superconducting (HTS) conductors bonded together at a thermally and electrically determined optimum point along the length of the current lead. By taking advantage of material properties of each conductor type, employing advanced fabrication techniques, and taking advantage of novel insulation materials, the company was able to develop and fabricate the lightweight, low heat-leak leads currently to NASA's specs.

Technicians prepare to close hatches on Gemini 12 spacecraft

NASA Technical Reports Server (NTRS)

1966-01-01

Technicians prepare to close the hatches of the Gemini 12 spacecraft in the White Room atop Pad 19 after insertion of Astronauts James A. Lovell Jr. (leading), command pilot, and Edwin E. Aldrin Jr., pilot.

Primary prevention of pediatric lead exposure requires new approaches to transfusion screening.

PubMed

Gehrie, Eric; Keiser, Amaris; Dawling, Sheila; Travis, James; Strathmann, Frederick G; Booth, Garrett S

2013-09-01

To facilitate further assessment of transfusion-associated lead exposure by designing a procedure to test packed red blood cells (pRBCs) prepared for transfusion. The relationship between pRBCs and whole blood lead concentration was investigated in 27 samples using a modified clinical assay. Lead concentrations were measured in 100 pRBC units. Our sample preparation method demonstrated a correlation between whole blood lead and pRBC lead concentrations (R(2) = 0.82). In addition, all 100 pRBC units tested had detectable lead levels. The median pRBC lead concentration was 0.8 μg/dL, with an SD of 0.8 μg/dL and a range of 0.2-4.1 μg/dL. In addition, after only a few days of storage, approximately 25% of whole blood lead was found in the supernatant plasma. Transfusion of pRBCs is a source of lead exposure. Here we report the quantification of lead concentration in pRBCs. We found a >20-fold range of lead concentrations in the samples tested. Pretransfusion testing of pRBC units according to our proposed approach or donor screening of whole blood lead and selection of below-average units for transfusion to children would diminish an easily overlooked source of pediatric lead exposure. Copyright © 2013 Mosby, Inc. All rights reserved.

SOURCES OF VARIABILITY IN COLLECTION AND PREPARATION OF PAINT AND LEAD-COATING SAMPLES

EPA Science Inventory

Chronic exposure of children to lead can result in permanent physiologic impairment. Since surfaces coated with lead-containing paints and varnishes are potential sources of exposure, it is extremely important that reliable methods for sampling and analysis be available. The so...

Template-guided vs. non-guided drilling in site preparation of dental implants.

PubMed

Scherer, Uta; Stoetzer, Marcus; Ruecker, Martin; Gellrich, Nils-Claudius; von See, Constantin

2015-07-01

Clinical success of oral implants is related to primary stability and osseointegration. These parameters are associated with delicate surgical techniques. We herein studied whether template-guided drilling has a significant influence on drillholes diameter and accuracy in an in vitro model. Fresh cadaveric porcine mandibles were used for drilling experiments of four experimental groups. Each group consisted of three operators, comparing guide templates for drilling with free-handed procedure. Operators without surgical knowledge were grouped together, contrasting highly experienced oral surgeons in other groups. A total of 180 drilling actions were performed, and diameters were recorded at multiple depth levels, with a precision measuring instrument. Template-guided drilling procedure improved accuracy on a very significant level in comparison with free-handed drilling operation (p ≤ 0.001). Inaccuracy of free-handed drilling became more significant in relation to measurement depth. High homogenic uniformity of template-guided drillholes was significantly stronger than unguided drilling operations by highly experienced oral surgeons (p ≤ 0.001). Template-guided drilling procedure leads to significantly enhanced accuracy. Significant results compared to free-handed drilling actions were achieved, irrespective of the clinical experience level of the operator. Template-guided drilling procedures lead to a more predictable clinical diameter. It shows that any set of instruments has to be carefully chosen to match the specific implant system. The current in vitro study is implicating an improvement of implant bed preparation but needs to be confirmed in clinical studies.

OPTIMIZATION OF FUROSEMIDE LIQUISOLID TABLETS PREPARATION PROCESS LEADING TO THEIR MASS AND SIZE REDUCTION.

PubMed

Kurek, Mateusz; Woyna-Orlewicz, Krzysztof; Khalid, Mohammad Hassan; Jachowicz, Renata

2016-09-01

The great number of drug substances currently used in solid oral dosage forms is characterized by poor water solubility. Therefore, various methods of dissolution rate enhancement are an important topic of research interest in modem drug technology. The purpose of this study was to enhance the furosemide dissolution rate from liquisolid tablets while maintaining an acceptable size and mass. Two types of dibasic calcium phosphate (Fujicalin®/Emcompress®) and microcrystalline cellulose (Vivapur® 102/Vivapur® 12) were used as carriers and magnesium aluminometasilicate (Neusilin® US2) was used as a coating material. The flowable liquid retention potential for those excipients was tested by measuring the angle of slide. To evaluate the impact of used excipients on tablet properties fourteen tablet formulations were prepared. It was found that LS2 tablets containing spherically granulated dibasic calcium phosphate and magnesium aluminometasilicate exhibit the best dissolution profile and mechanical properties while tablets composed only with Neusilin® US2 was characterized by the smallest size and mass with preserved good mechanical properties and furosemide dissolution.

Automation in biological crystallization.

PubMed

Stewart, Patrick Shaw; Mueller-Dieckmann, Jochen

2014-06-01

Crystallization remains the bottleneck in the crystallographic process leading from a gene to a three-dimensional model of the encoded protein or RNA. Automation of the individual steps of a crystallization experiment, from the preparation of crystallization cocktails for initial or optimization screens to the imaging of the experiments, has been the response to address this issue. Today, large high-throughput crystallization facilities, many of them open to the general user community, are capable of setting up thousands of crystallization trials per day. It is thus possible to test multiple constructs of each target for their ability to form crystals on a production-line basis. This has improved success rates and made crystallization much more convenient. High-throughput crystallization, however, cannot relieve users of the task of producing samples of high quality. Moreover, the time gained from eliminating manual preparations must now be invested in the careful evaluation of the increased number of experiments. The latter requires a sophisticated data and laboratory information-management system. A review of the current state of automation at the individual steps of crystallization with specific attention to the automation of optimization is given.

Automation in biological crystallization

PubMed Central

Shaw Stewart, Patrick; Mueller-Dieckmann, Jochen

2014-01-01

Crystallization remains the bottleneck in the crystallographic process leading from a gene to a three-dimensional model of the encoded protein or RNA. Automation of the individual steps of a crystallization experiment, from the preparation of crystallization cocktails for initial or optimization screens to the imaging of the experiments, has been the response to address this issue. Today, large high-throughput crystallization facilities, many of them open to the general user community, are capable of setting up thousands of crystallization trials per day. It is thus possible to test multiple constructs of each target for their ability to form crystals on a production-line basis. This has improved success rates and made crystallization much more convenient. High-throughput crystallization, however, cannot relieve users of the task of producing samples of high quality. Moreover, the time gained from eliminating manual preparations must now be invested in the careful evaluation of the increased number of experiments. The latter requires a sophisticated data and laboratory information-management system. A review of the current state of automation at the individual steps of crystallization with specific attention to the automation of optimization is given. PMID:24915074

The Molecular Structure of Human Red Blood Cell Membranes from Highly Oriented, Solid Supported Multi-Lamellar Membranes

PubMed Central

Himbert, Sebastian; Alsop, Richard J.; Rose, Markus; Hertz, Laura; Dhaliwal, Alexander; Moran-Mirabal, Jose M.; Verschoor, Chris P.; Bowdish, Dawn M. E.; Kaestner, Lars; Wagner, Christian; Rheinstädter, Maikel C.

2017-01-01

We prepared highly oriented, multi-lamellar stacks of human red blood cell (RBC) membranes applied on silicon wafers. RBC ghosts were prepared by hemolysis and applied onto functionalized silicon chips and annealed into multi-lamellar RBC membranes. High resolution X-ray diffraction was used to determine the molecular structure of the stacked membranes. We present direct experimental evidence that these RBC membranes consist of nanometer sized domains of integral coiled-coil peptides, as well as liquid ordered (lo) and liquid disordered (ld) lipids. Lamellar spacings, membrane and hydration water layer thicknesses, areas per lipid tail and domain sizes were determined. The common drug aspirin was added to the RBC membranes and found to interact with RBC membranes and preferably partition in the head group region of the lo domain leading to a fluidification of the membranes, i.e., a thinning of the bilayers and an increase in lipid tail spacing. Our results further support current models of RBC membranes as patchy structures and provide unprecedented structural details of the molecular organization in the different domains. PMID:28045119

Developing DIII-D To Prepare For ITER And The Path To Fusion Energy

NASA Astrophysics Data System (ADS)

Buttery, Richard; Hill, David; Solomon, Wayne; Guo, Houyang; DIII-D Team

2017-10-01

DIII-D pursues the advancement of fusion energy through scientific understanding and discovery of solutions. Research targets two key goals. First, to prepare for ITER we must resolve how to use its flexible control tools to rapidly reach Q =10, and develop the scientific basis to interpret results from ITER for fusion projection. Second, we must determine how to sustain a high performance fusion core in steady state conditions, with minimal actuators and a plasma exhaust solution. DIII-D will target these missions with: (i) increased electron heating and balanced torque neutral beams to simulate burning plasma conditions (ii) new 3D coil arrays to resolve control of transients (iii) off axis current drive to study physics in steady state regimes (iv) divertors configurations to promote detachment with low upstream density (v) a reactor relevant wall to qualify materials and resolve physics in reactor-like conditions. With new diagnostics and leading edge simulation, this will position the US for success in ITER and a unique knowledge to accelerate the approach to fusion energy. Supported by the US DOE under DE-FC02-04ER54698.

Dielectric behaviour of montmorillonite/cyanoethylated cellulose nanocomposites.

PubMed

Madusanka, Nadeesh; Shivareddy, Sai G; Eddleston, Mark D; Hiralal, Pritesh; Oliver, Rachel A; Amaratunga, Gehan A J

2017-09-15

A dielectric nanocomposite based oncyanoethylatedcellulose (CRS) and MMT nanoclay was successfully prepared with different weight percentages (5%, 10% and 15%) of MMT. MMT nanoplatets obtained via sonication of MMT nanoclay in acetone for a prolonged period was used in the preparation of CRS-MMT nanocomposites. CRS-MMT thin films on SiO 2 /Si wafers are used to form metal-insulator-metal (MIM) type capacitors. At 1kHz CRS-MMT nanocomposites exhibited high dielectric constants (ε r ) of 71, 55 and 42 with low leakage current densities (10 -6 -10 -7 A/cm 2 ) for nanocomposites with 5%, 10% and 15% weight of MMT respectively, higher than values of pure CRS (21), Na-MMT(10). Reduction of ε r with higher MMT loading can be attributed to a network formation as evidenced via strong bonding interactions between CRS and MMT leading to a lower molecular mobility. The leakage is studied using conductive atomic force microscopy (C-AFM) indicates that leakage pathways are associated with MMT nanoplatelets embedded in the CRS polymer matrix. Copyright © 2017. Published by Elsevier Ltd.

Green synthesis of in situ electrodeposited rGO/MnO2 nanocomposite for high energy density supercapacitors.

PubMed

Rusi; Majid, S R

2015-11-05

This paper presents the preparation of in situ electrodeposited rGO/MnO2 nanocomposite as a binder-free electrode for supercapacitor application. The work describes and evaluates the performance of prepared electrode via green and facile electrodeposition technique of in situ rGO/MnO2-glucose carbon nanocomposites. The carbon content in the composite electrode increased after GO and D (+) glucose solution has been added in the deposition electrolyte. This study found that a suitable concentration of D (+) glucose in the deposition electrolyte can slow down the nucleation process of MnO2 particles and lead to uniform and ultrathin nanoflakes structure. The optimize electrode exhibited low transfer resistance and resulted on excellent electrochemical performance in three electrolyte systems viz. Na2SO4, KOH and KOH/K3Fe(CN)6 redox electrolytes. The optimum energy density and power density were 1851 Whkg(-1) and 68 kWkg(-1) at current density of 20 Ag(-1) in mixed KOH/K3Fe(CN)6 electrolyte.

Green synthesis of in situ electrodeposited rGO/MnO2 nanocomposite for high energy density supercapacitors

NASA Astrophysics Data System (ADS)

Rusi; Majid, S. R.

2015-11-01

This paper presents the preparation of in situ electrodeposited rGO/MnO2 nanocomposite as a binder-free electrode for supercapacitor application. The work describes and evaluates the performance of prepared electrode via green and facile electrodeposition technique of in situ rGO/MnO2-glucose carbon nanocomposites. The carbon content in the composite electrode increased after GO and D (+) glucose solution has been added in the deposition electrolyte. This study found that a suitable concentration of D (+) glucose in the deposition electrolyte can slow down the nucleation process of MnO2 particles and lead to uniform and ultrathin nanoflakes structure. The optimize electrode exhibited low transfer resistance and resulted on excellent electrochemical performance in three electrolyte systems viz. Na2SO4, KOH and KOH/K3Fe(CN)6 redox electrolytes. The optimum energy density and power density were 1851 Whkg-1 and 68 kWkg-1 at current density of 20 Ag-1 in mixed KOH/K3Fe(CN)6 electrolyte.

Fast fabrication of NiO@graphene composites for supercapacitor electrodes: Combination of reduction and deposition.

PubMed

Hui, Xu; Qian, Luming; Harris, Gary; Wang, Tongxin; Che, Jianfei

2016-11-05

Graphene-based inorganic composites have been attracting more and more attention since the attachment of inorganic nanoparticles instead of conducting polymeric materials to graphene sheets turns out higher capacitances and good capacity retention. Here we report a fast fabrication method to prepare NiO@graphene composite modified electrodes for supercapacitors. By this method, preparation of electrochemical active materials of NiO/graphene and modification of the electrode can be simultaneously performed, which is achieved separately by traditional method. Moreover, the problem of poor adhesion of active materials on the surface of the electrode can be well solved. The NiO particles introduced to the films exhibit pseudocapacitive behavior arising from the reversible Faradaic transitions of Ni(II)/Ni(III) and greatly improve the capacitance of the electrodes. With the increase in NiO content, highly reduced graphene can be obtained during cyclic voltammetry sweeping, leading to the increase in the electrode capacitance. The highest specific capacitance of the constructed electrodes can reach 1258 F/g at a current density of 5 A/g.

Iron oxide shell coating on nano silicon prepared from the sand for lithium-ion battery application

NASA Astrophysics Data System (ADS)

Furquan, Mohammad; Vijayalakshmi, S.; Mitra, Sagar

2018-05-01

Elemental silicon, due to its high specific capacity (4200 mAh g-1) and non-toxicity is expected to be an attractive anode material for Li-ion battery. But its huge expansion volume (> 300 %) during charging of battery, leads to pulverization and cracking in the silicon particles and causes sudden failure of the Li-ion battery. In this work, we have designed yolk-shell type morphology of silicon, prepared from carbon coated silicon nanoparticles soaked in aqueous solution of ferric nitrate and potassium hydroxide. The soaked silicon particles were dried and finally calcined at 800 °C for 30 minutes. The product obtained is deprived of carbon and has a kind of yolk-shell morphology of nano silicon with iron oxide coating (Si@Iron oxide). This material has been tested for half-cell lithium-ion battery configuration. The discharge capacity is found to be ≈ 600 mAh g-1 at a current rate of 1.0 A g-1 for 200 cycles. It has shown a stable performance as anode for Li-ion battery application.

Green synthesis of in situ electrodeposited rGO/MnO2 nanocomposite for high energy density supercapacitors

PubMed Central

Rusi; Majid, S. R.

2015-01-01

This paper presents the preparation of in situ electrodeposited rGO/MnO2 nanocomposite as a binder-free electrode for supercapacitor application. The work describes and evaluates the performance of prepared electrode via green and facile electrodeposition technique of in situ rGO/MnO2-glucose carbon nanocomposites. The carbon content in the composite electrode increased after GO and D (+) glucose solution has been added in the deposition electrolyte. This study found that a suitable concentration of D (+) glucose in the deposition electrolyte can slow down the nucleation process of MnO2 particles and lead to uniform and ultrathin nanoflakes structure. The optimize electrode exhibited low transfer resistance and resulted on excellent electrochemical performance in three electrolyte systems viz. Na2SO4, KOH and KOH/K3Fe(CN)6 redox electrolytes. The optimum energy density and power density were 1851 Whkg−1 and 68 kWkg−1 at current density of 20 Ag−1 in mixed KOH/K3Fe(CN)6 electrolyte. PMID:26537363

Electrochemical investigation of MoTe2/rGO composite materials for sodium-ion battery application

NASA Astrophysics Data System (ADS)

Panda, Manas Ranjan; Anish Raj, K.; Sarkar, Ananta; Bao, Qiaoliang; Mitra, Sagar

2018-05-01

2D layered materials are found to be promising anode materials for renewable energy storage devices like sodium and Li-ion batteries and have become attractive options due to their high specific capacity, abundance and low cost. In this work, we synthesized 2D MoTe2 layers embedded in reduced graphene oxide (rGO) anode material for sodium-ion battery applications. 2D MoTe2 was prepared by a solid-state reaction in vacuum at a temperature of 800 °C. The prepared composite material MoTe2/rGO showed excellent electrochemical performance against the sodium metal. The discharge capacity of MoTe2/rGO was observed to be 280 mAh g-1 at a current rate of 1.0 A g-1 for 100 cycles. rGO plays an important role in embedding the MoTe2 structure, thus improving the electrical and mechanical properties, leading to a superior cycling stability and excellent electrochemical performances of MoTe2 for sodium-ion battery applications.

The Molecular Structure of Human Red Blood Cell Membranes from Highly Oriented, Solid Supported Multi-Lamellar Membranes

NASA Astrophysics Data System (ADS)

Himbert, Sebastian; Alsop, Richard J.; Rose, Markus; Hertz, Laura; Dhaliwal, Alexander; Moran-Mirabal, Jose M.; Verschoor, Chris P.; Bowdish, Dawn M. E.; Kaestner, Lars; Wagner, Christian; Rheinstädter, Maikel C.

2017-01-01

We prepared highly oriented, multi-lamellar stacks of human red blood cell (RBC) membranes applied on silicon wafers. RBC ghosts were prepared by hemolysis and applied onto functionalized silicon chips and annealed into multi-lamellar RBC membranes. High resolution X-ray diffraction was used to determine the molecular structure of the stacked membranes. We present direct experimental evidence that these RBC membranes consist of nanometer sized domains of integral coiled-coil peptides, as well as liquid ordered (lo) and liquid disordered (ld) lipids. Lamellar spacings, membrane and hydration water layer thicknesses, areas per lipid tail and domain sizes were determined. The common drug aspirin was added to the RBC membranes and found to interact with RBC membranes and preferably partition in the head group region of the lo domain leading to a fluidification of the membranes, i.e., a thinning of the bilayers and an increase in lipid tail spacing. Our results further support current models of RBC membranes as patchy structures and provide unprecedented structural details of the molecular organization in the different domains.

Structural and Immunological Analysis of Anthrax Recombinant Protective Antigen Adsorbed to Aluminum Hydroxide Adjuvant

PubMed Central

Wagner, Leslie; Verma, Anita; Meade, Bruce D.; Reiter, Karine; Narum, David L.; Brady, Rebecca A.; Little, Stephen F.

2012-01-01

New anthrax vaccines currently under development are based on recombinant protective antigen (rPA) and formulated with aluminum adjuvant. Because long-term stability is a desired characteristic of these vaccines, an understanding of the effects of adsorption to aluminum adjuvants on the structure of rPA is important. Using both biophysical and immunological techniques, we compared the structure and immunogenicity of freshly prepared rPA-Alhydrogel formulations to that of formulations stored for 3 weeks at either room temperature or 37°C in order to assess the changes in rPA structure that might occur upon long-term storage on aluminum adjuvant. Intrinsic fluorescence emission spectra of tryptophan residues indicated that some tertiary structure alterations of rPA occurred during storage on Alhydrogel. Using anti-PA monoclonal antibodies to probe specific regions of the adsorbed rPA molecule, we found that two monoclonal antibodies that recognize epitopes located in domain 1 of PA exhibited greater reactivity to the stored formulations than to freshly prepared formulations. Immunogenicity of rPA-Alhydrogel formulations in mice was assessed by measuring the induction of toxin-neutralizing antibodies, as well as antibodies reactive to 12-mer peptides spanning the length of PA. Mice immunized with freshly prepared formulations developed significantly higher toxin-neutralizing antibody titers than mice immunized with the stored preparations. In contrast, sera from mice immunized with stored preparations exhibited increased reactivity to nine 12-mer peptides corresponding to sequences located throughout the rPA molecule. These results demonstrate that storage of rPA-Alhydrogel formulations can lead to structural alteration of the protein and loss of the ability to elicit toxin-neutralizing antibodies. PMID:22815152

Optimizing Illumina next-generation sequencing library preparation for extremely AT-biased genomes.

PubMed

Oyola, Samuel O; Otto, Thomas D; Gu, Yong; Maslen, Gareth; Manske, Magnus; Campino, Susana; Turner, Daniel J; Macinnis, Bronwyn; Kwiatkowski, Dominic P; Swerdlow, Harold P; Quail, Michael A

2012-01-03

Massively parallel sequencing technology is revolutionizing approaches to genomic and genetic research. Since its advent, the scale and efficiency of Next-Generation Sequencing (NGS) has rapidly improved. In spite of this success, sequencing genomes or genomic regions with extremely biased base composition is still a great challenge to the currently available NGS platforms. The genomes of some important pathogenic organisms like Plasmodium falciparum (high AT content) and Mycobacterium tuberculosis (high GC content) display extremes of base composition. The standard library preparation procedures that employ PCR amplification have been shown to cause uneven read coverage particularly across AT and GC rich regions, leading to problems in genome assembly and variation analyses. Alternative library-preparation approaches that omit PCR amplification require large quantities of starting material and hence are not suitable for small amounts of DNA/RNA such as those from clinical isolates. We have developed and optimized library-preparation procedures suitable for low quantity starting material and tolerant to extremely high AT content sequences. We have used our optimized conditions in parallel with standard methods to prepare Illumina sequencing libraries from a non-clinical and a clinical isolate (containing ~53% host contamination). By analyzing and comparing the quality of sequence data generated, we show that our optimized conditions that involve a PCR additive (TMAC), produces amplified libraries with improved coverage of extremely AT-rich regions and reduced bias toward GC neutral templates. We have developed a robust and optimized Next-Generation Sequencing library amplification method suitable for extremely AT-rich genomes. The new amplification conditions significantly reduce bias and retain the complexity of either extremes of base composition. This development will greatly benefit sequencing clinical samples that often require amplification due to low mass of DNA starting material.

Preparing university students to lead K-12 engineering outreach programmes: a design experiment

NASA Astrophysics Data System (ADS)

Anthony, Anika B.; Greene, Howard; Post, Paul E.; Parkhurst, Andrew; Zhan, Xi

2016-11-01

This paper describes an engineering outreach programme designed to increase the interest of under-represented youth in engineering and to disseminate pre-engineering design challenge materials to K-12 educators and volunteers. Given university students' critical role as facilitators of the outreach programme, researchers conducted a two-year design experiment to examine the programme's effectiveness at preparing university students to lead pre-engineering activities. Pre- and post-surveys incorporated items from the Student Engagement sub-scale of the Teacher Sense of Efficacy Scale. Surveys were analysed using paired-samples t-test. Interview and open-ended survey data were analysed using discourse analysis and the constant comparative method. As a result of participation in the programme, university students reported a gain in efficacy to lead pre-engineering activities. The paper discusses programme features that supported efficacy gains and concludes with a set of design principles for developing learning environments that effectively prepare university students to facilitate pre-engineering outreach programmes.

Preparation of PbS Nanoparticles by Phase-Transfer Method and Application to Pb2+-Selective Electrode Based on PVC Membrane

PubMed Central

Song, Weihong; Wu, Chunhui; Yin, Hongzong; Liu, Xiaoyan; Sa, Panpan; Hu, Jinyang

2008-01-01

A novel approach to prepare homogeneous PbS nanoparticles by phase-transfer method was developed. The preparatory conditions were studied in detail, and the nanoparticles were characterized by transmission electron microscopy (TEM) and UV-vis spectroscopy. Then a novel lead ion-selective electrode of polyvinyl chloride (PVC) membrane based on these lead sulfide nanoparticles was prepared, and the optimum ratio of components in the membrane was determined. The results indicated that the sensor exhibited a wide concentration range of 1.0×10−5 to 1.0×10−2 mol.L−1. The response time of the electrode was about 10 s, and the optimal pH in which the electrode could be used was from 3.0 to 7.0. Selectivity coefficients indicated that the electrode was selective to the primary ion over the interfering ion. The electrode can be used for at least 3 months without any divergence in potential. It was successfully applied to directly determine lead ions in solution and used as an indicator electrode in potentiometric titration of lead ions with EDTA. PMID:19112518

Teacher Preparation Practices in Kenya and the 21st Century Learning: A Moral Obligation

ERIC Educational Resources Information Center

Kafwa, Nabwire Opata; Gaudience, Obondo; Kisaka, Sella Terrie

2015-01-01

Teacher preparation practices are indices used to measure quality teacher besides other variables. Whereas the current teacher preparation is test scores based inclining to cognitive knowledge, a good teacher preparation practices is a holistic development in nature oriented towards character, skills and knowledge. To embed teacher preparation in…

Lead Free Electric Primer

DTIC Science & Technology

2011-10-06

composites were prepared with varying metal to oxidizer (M/O) ratios ranging from 0.782 to 3.165 (see Table 7). The performance was measured by the...and the Army was expecting to begin their processing efforts in the near future. The Army purchased primer metal parts and was prepared to perform...43 Table 19 – Samples Prepared Using Different Mix Times and Amplitudes

Looked after or Left Behind: The Effectiveness of Principal Preparation Programs as Perceived by Generation Y Principals

ERIC Educational Resources Information Center

Sledge, Chandra

2013-01-01

This research study intended to discover the perceptions of 10 Illinois Generation Y novice high school principals pertaining to the effectiveness of their principal preparation programs in terms of how well it prepared them to lead in the first three years of their principalship, and what subsequent professional development they deemed necessary…

Preparation and adsorption characteristics for heavy metals of active silicon adsorbent from leaching residue of lead-zinc tailings.

PubMed

Lei, Chang; Yan, Bo; Chen, Tao; Xiao, Xian-Ming

2018-05-19

To comprehensively reuse the leaching residue obtained from lead-zinc tailings, an active silicon adsorbent (ASA) was prepared from leaching residue and studied as an adsorbent for copper(II), lead(II), zinc(II), and cadmium(II) in this paper. The ASA was prepared by roasting the leaching residue with either a Na 2 CO 3 /residue ratio of 0.6:1 at 700 °C for 1 h or a CaCO 3 /residue ratio of 0.8:1 at 800 °C for 1 h. Under these conditions, the available SiO 2 content of the ASA was more than 20%. The adsorption behaviors of the metal ions onto the ASA were investigated and the Langmuir, Freundlich, and Dubinin-Radushkevich isotherm models were used to analyze the adsorption isotherm. The result showed that the maximum adsorption capacities of copper(II), lead(II), cadmium(II), and zinc(II) calculated by the Langmuir model were 3.40, 2.83, 0.66, and 0.62 mmol g -1 , respectively. The FT-IR spectra of the ASA and the mean free adsorption energies indicated that ion exchange was the mechanism of copper(II), lead(II), and cadmium(II) adsorption and that chemical reaction was the mechanism of zinc(II) adsorption. These results provide a method for reusing the leaching residue obtained from lead-zinc tailings and show that the ASA is an effective adsorbent for heavy metal pollution remediation.

21 CFR 25.44 - Lead and cooperating agencies.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Lead and cooperating agencies. 25.44 Section 25.44 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ENVIRONMENTAL IMPACT CONSIDERATIONS Preparation of Environmental Documents § 25.44 Lead and cooperating agencies...

Preparation and optical characteristics of layered perovskite-type lead-bromide-incorporated azobenzene chromophores

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

Sasai, Ryo, E-mail: rsasai@riko.shimane-u.ac.jp; Shinomura, Hisashi

Lead bromide-based layered perovskite powders with azobenzene derivatives were prepared by a homogeneous precipitation method. From the diffuse reflectance (DR) and photoluminescence (PL) spectra of the hybrid powder materials, the present hybrids exhibited sharp absorption and PL peaks originating from excitons produced in the PbBr{sub 4}{sup 2-} layer. When the present hybrid powder was irradiated with UV light at 350 nm, the absorption band from the trans-azobenzene chromophore, observed around 350 nm, decreased, while the absorption band from the cis-azobenzene chromophore, observed around 450 nm, increased. These results indicate that azobenzene chromophores in the present hybrid materials exhibit reversible photoisomerization.more » Moreover, it was found that the PL intensity from the exciton also varied due to photoisomerization of the azobenzene chromophores in the present hybrid. Thus, for the first time we succeeded in preparing the azobenzene derivative lead-bromide-based layered perovskite with photochromism before and after UV light irradiation. - Graphical abstract: For the first time, we succeeded in preparing the azobenzene derivative lead-bromide-based layered perovskite with photochromism before and after UV light irradiation. Highlights: Black-Right-Pointing-Pointer PbBr-based layered perovskite with azobenezene derivatives could be synthesized by a homogeneous precipitation method. Black-Right-Pointing-Pointer Azobenzene derivatives incorporated the present hybrid that exhibited reversible photoisomerization under UV and/or visible light irradiation. Black-Right-Pointing-Pointer PL property of the present hybrid could also be varied by photoisomerization.« less

Potential artifacts associated with historical preparation of joint compound samples and reported airborne asbestos concentrations.

PubMed

Brorby, G P; Sheehan, P J; Berman, D W; Bogen, K T; Holm, S E

2011-05-01

Airborne samples collected in the 1970s for drywall workers using asbestos-containing joint compounds were likely prepared and analyzed according to National Institute of Occupational Safety and Health Method P&CAM 239, the historical precursor to current Method 7400. Experimentation with a re-created, chrysotile-containing, carbonate-based joint compound suggested that analysis following sample preparation by the historical vs. current method produces different fiber counts, likely because of an interaction between the different clearing and mounting chemicals used and the carbonate-based joint compound matrix. Differences were also observed during analysis using Method 7402, depending on whether acetic acid/dimethylformamide or acetone was used during preparation to collapse the filter. Specifically, air samples of sanded chrysotile-containing joint compound prepared by the historical method yielded fiber counts significantly greater (average of 1.7-fold, 95% confidence interval: 1.5- to 2.0-fold) than those obtained by the current method. In addition, air samples prepared by Method 7402 using acetic acid/dimethylformamide yielded fiber counts that were greater (2.8-fold, 95% confidence interval: 2.5- to 3.2-fold) than those prepared by this method using acetone. These results indicated (1) there is an interaction between Method P&CAM 239 preparation chemicals and the carbonate-based joint compound matrix that reveals fibers that were previously bound in the matrix, and (2) the same appeared to be true for Method 7402 preparation chemicals acetic acid/dimethylformamide. This difference in fiber counts is the opposite of what has been reported historically for samples of relatively pure chrysotile dusts prepared using the same chemicals. This preparation artifact should be considered when interpreting historical air samples for drywall workers prepared by Method P&CAM 239. Copyright © 2011 JOEH, LLC

Hybrid Lead Halide Layered Perovskites with Silsesquioxane Interlayers.

PubMed

Kataoka, Sho; Kaburagi, Wako; Mochizuki, Hiroyuki; Kamimura, Yoshihiro; Sato, Kazuhiko; Endo, Akira

2018-01-01

Hybrid organic-lead halide perovskites exhibit remarkable properties as semiconductors and light absorbers. Here, we report the formation of silsesquioxane-lead halide hybrid layered perovskites. We prepared silsesquioxane with a cubic cage-like structure and fabricated hybrid silsesquioxane-lead halide layered perovskites in a self-assembled manner. It is demonstrated that the silsesquioxane maintain their cage-like structure between lead halide perovskite layers. The silsesquioxane-lead halide perovskites also show excitonic absorption and emission in the visible light region similar to typical lead halide layered perovskites.

Critical current densities in superconducting Y-Ba-Cu-O prepared by chelating method

NASA Astrophysics Data System (ADS)

Fujisawa, Tadashi; Okuyama, Katsuro; Ohshima, Shigetoshi; Takagi, Akira

1990-10-01

The IDA, NTA, HEDTA, EDTA, TTHA, and DTPA chelating agents have been used to prepare the Y-Ba-Cu-O compounds whose critical current is presently investigated. It is noted that the precursor YBCO prepared from large stability-constant metal complexes (HEDTA, EDTA, DTPA, and TTHA) exhibited very fine and homogeneous particles. The critical current density of a 1 x 4 x 15 mm block of YBCO sintered at 880-910 C for 24 h and subsequently annealed at 500 C in an O2 flow was approximately 500 A/sq cm at 77 K, in zero magnetic field.

Analytical electron microscopy in the study of biological systems.

PubMed

Johnson, D E

1986-01-01

The AEM is a powerful tool in biological research, capable of providing information simply not available by other means. The use of a field emission STEM for this application can lead to a significant improvement in spatial resolution in most cases now allowed by the quality of the specimen preparation but perhaps ultimately limited by the effects of radiation damage. Increased elemental sensitivity is at least possible in selected cases with electron energy-loss spectrometry, but fundamental aspects of ELS will probably confine its role to that of a limited complement to EDS. The considerable margin for improvement in sensitivity of the basic analytical technique means that the search for technological improvement will continue. Fortunately, however, current technology can also continue to answer important biological questions.

Magnetic nanoparticle drug delivery systems for targeting tumor

NASA Astrophysics Data System (ADS)

Mody, Vicky V.; Cox, Arthur; Shah, Samit; Singh, Ajay; Bevins, Wesley; Parihar, Harish

2014-04-01

Tumor hypoxia, or low oxygen concentration, is a result of disordered vasculature that lead to distinctive hypoxic microenvironments not found in normal tissues. Many traditional anti-cancer agents are not able to penetrate into these hypoxic zones, whereas, conventional cancer therapies that work by blocking cell division are not effective to treat tumors within hypoxic zones. Under these circumstances the use of magnetic nanoparticles as a drug delivering agent system under the influence of external magnetic field has received much attention, based on their simplicity, ease of preparation, and ability to tailor their properties for specific biological applications. Hence in this review article we have reviewed current magnetic drug delivery systems, along with their application and clinical status in the field of magnetic drug delivery.

Thermal Molding of Organic Thin-Film Transistor Arrays on Curved Surfaces.

PubMed

Sakai, Masatoshi; Watanabe, Kento; Ishimine, Hiroto; Okada, Yugo; Yamauchi, Hiroshi; Sadamitsu, Yuichi; Kudo, Kazuhiro

2017-12-01

In this work, a thermal molding technique is proposed for the fabrication of plastic electronics on curved surfaces, enabling the preparation of plastic films with freely designed shapes. The induced strain distribution observed in poly(ethylene naphthalate) films when planar sheets were deformed into hemispherical surfaces clearly indicated that natural thermal contraction played an important role in the formation of the curved surface. A fingertip-shaped organic thin-film transistor array molded from a real human finger was fabricated, and slight deformation induced by touching an object was detected from the drain current response. This type of device will lead to the development of robot fingers equipped with a sensitive tactile sense for precision work such as palpation or surgery.

Public Health Intelligence: Learning From the Ebola Crisis

PubMed Central

Weber, David Jay

2015-01-01

Today’s public health crises, as exemplified by the Ebola outbreak, lead to dramatic calls to action that typically include improved electronic monitoring systems to better prepare for, and respond to, similar occurrences in the future. Even a preliminary public health informatics evaluation of the current Ebola crisis exposes the need for enhanced coordination and sharing of trustworthy public health intelligence. We call for a consumer-centric model of public health intelligence and the formation of a national center to guide public health intelligence gathering and synthesis. Sharing accurate and actionable information with government agencies, health care practitioners, policymakers, and, critically, the general public, will mark a shift from doing public health surveillance on people to doing public health surveillance for people. PMID:26180978

Enviromental sanitation in urban and rural areas: its importance in the control of enteric infections.

PubMed

Wolman, A

1975-01-01

In Central and South America, enteric infections constitute one of the leading causes of disease and death. The terrible toll is exacted by a host of different microorganisms, virtually all of which are transmitted via contact with human excreta. To change this picture we need many more water supply and sewerage systems, better food preparation and handling, and public comprehension of how elementary good hygiene promotes good health. Attaining these objectives will be difficult, but less costly than one might suppose, and there is little to be gained by delay. The basic enviromental causes of enteric disease are clear, current conditions have been aggravated by rapid population growth and urbanization, and basic corrective measures have already been postponed long enough.

Gamification for Measuring Cyber Security Situational Awareness

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

Fink, Glenn A.; Best, Daniel M.; Manz, David O.

Cyber defense competitions arising from U.S. service academy exercises, offer a platform for collecting data that can inform research that ranges from characterizing the ideal cyber warrior to describing behaviors during certain challenging cyber defense situations. This knowledge could lead to better preparation of cyber defenders in both military and civilian settings. This paper describes how one regional competition, the PRCCDC, a participant in the national CCDC program, conducted proof of concept experimentation to collect data during the annual competition for later analysis. The intent is to create an ongoing research agenda that expands on this current work and incorporatesmore » augmented cognition and gamification methods for measuring cybersecurity situational awareness under the stress of cyber attack.« less

Research of the photovoltaic properties of anodized films of Sn

NASA Astrophysics Data System (ADS)

Afanasyev, D. A.; Ibrayev, N. Kh; Omarova, G. S.; Smagulov, Zh K.

2015-04-01

The results of studies of photovoltaic properties of solar cells based on porous tin oxide films, sensitized with an organic dye are presented. Porous films were prepared by electrochemical anodization of tin in alkaline electrolytes based on aqueous solution of NaOH and aqueous ammonia NH4OH. It was found that the time of anodizing of the Sn films affects on conversion efficiency of light energy into electrical energy. Increasing of the sorption time leads to an increase of the number of molecules on the surface of the porous film. For the solar cell based on tin oxide there is a strong dark current, which significantly reduces the efficiency of conversion of light energy into electrical energy.

Thermal Molding of Organic Thin-Film Transistor Arrays on Curved Surfaces

NASA Astrophysics Data System (ADS)

Sakai, Masatoshi; Watanabe, Kento; Ishimine, Hiroto; Okada, Yugo; Yamauchi, Hiroshi; Sadamitsu, Yuichi; Kudo, Kazuhiro

2017-05-01

In this work, a thermal molding technique is proposed for the fabrication of plastic electronics on curved surfaces, enabling the preparation of plastic films with freely designed shapes. The induced strain distribution observed in poly(ethylene naphthalate) films when planar sheets were deformed into hemispherical surfaces clearly indicated that natural thermal contraction played an important role in the formation of the curved surface. A fingertip-shaped organic thin-film transistor array molded from a real human finger was fabricated, and slight deformation induced by touching an object was detected from the drain current response. This type of device will lead to the development of robot fingers equipped with a sensitive tactile sense for precision work such as palpation or surgery.

Skype Me! Astronomers, Students, and Cutting-Edge Research

NASA Astrophysics Data System (ADS)

Hickox, Ryan C.; Gauthier, Adrienne J.

2014-06-01

A primary goal of many university science courses is to promote understanding of the process of contemporary scientific inquiry. One powerful way to achieve this is for students to explore current research and then interact directly with the leading scientist, the feasibility of which has recently increased dramatically due to free online video communication tools. We report on a program implemented at Dartmouth College in which students connect with a guest astronomer through Skype (video chat). The Skype session is wrapped in a larger activity where students explore current research articles, interact with the astronomer, and then reflect on the experience. The in-class Skype discussions require a small time commitment from scientists (20-30 minutes, with little or no need for preparation) while providing students direct access to researchers at the cutting edge of modern astronomy. We outline the procedures used to implement these discussions, and present qualitative assessments of student's understanding of the process of research, as well as feedback from the guest astronomers.

Vapor phase polymerization deposition of conducting polymer/graphene nanocomposites as high performance electrode materials.

PubMed

Yang, Yajie; Li, Shibin; Zhang, Luning; Xu, Jianhua; Yang, Wenyao; Jiang, Yadong

2013-05-22

In this paper, we report chemical vapor phase polymerization (VPP) deposition of novel poly(3,4-ethylenedioxythiophene) (PEDOT)/graphene nanocomposites as solid tantalum electrolyte capacitor cathode films. The PEDOT/graphene films were successfully prepared on porous tantalum pentoxide surface as cathode films through the VPP procedure. The results indicated that the high conductivity nature of PEDOT/graphene leads to the decrease of cathode films resistance and contact resistance between PEDOT/graphene and carbon paste. This nanocomposite cathode film based capacitor showed ultralow equivalent series resistance (ESR) ca. 12 mΩ and exhibited better capacitance-frequency performance than the PEDOT based capacitor. The leakage current investigation revealed that the device encapsulation process does not influence capacitor leakage current, indicating the excellent mechanical strength of PEDOT-graphene films. The graphene showed a distinct protection effect on the dielectric layer from possible mechanical damage. This high conductivity and mechanical strength graphene based conducting polymer nanocomposites indicated a promising application future for organic electrode materials.

Is It the Intervention or the Students? Using Linear Regression to Control for Student Characteristics in Undergraduate STEM Education Research

PubMed Central

Theobald, Roddy; Freeman, Scott

2014-01-01

Although researchers in undergraduate science, technology, engineering, and mathematics education are currently using several methods to analyze learning gains from pre- and posttest data, the most commonly used approaches have significant shortcomings. Chief among these is the inability to distinguish whether differences in learning gains are due to the effect of an instructional intervention or to differences in student characteristics when students cannot be assigned to control and treatment groups at random. Using pre- and posttest scores from an introductory biology course, we illustrate how the methods currently in wide use can lead to erroneous conclusions, and how multiple linear regression offers an effective framework for distinguishing the impact of an instructional intervention from the impact of student characteristics on test score gains. In general, we recommend that researchers always use student-level regression models that control for possible differences in student ability and preparation to estimate the effect of any nonrandomized instructional intervention on student performance. PMID:24591502

Current practices of Asia-Pacific cardiologists in the utilization of bioresorbable scaffolds.

PubMed

Chanana, B B; Chandra, Praveen; Cheng, Jack Jun; Dick, Ron; Gwon, Hyeon-Cheol; Hiremath, M S; Huan, Do Quang; Jeamanukoolkit, Anuruck; Jiang, Tiemin; Kwok, On-Hing; Lim, Michael C L; Low, Adrian F; Mathew, Rony; Mathew, Samuel K; McClean, Dougal; Nakamura, Sunao; Nguyen, Michael; Qiao, Shubin; Santoso, Teguh; Saxena, Sudheer; Schultz, Carl; Sengottuvelu, G; Seth, Ashok; Simonton, Charles A; Soo, Chee Siong; Sudhir, Krishnankutty; Tsai, Cheng-Ting; Wasan, Udayachalerm; Whelan, Alan; Wong, Chris; Yap, Yee Guan

2016-11-01

Although Absorb Bioresorbable Vascular Scaffolds (A-BVS) are routinely used in the Asia-Pacific, there is little information on patient selection or deployment technique here. This document investigates the experiences of leading interventional cardiologists from the Asia-Pacific region with a focus on patient characteristics, deployment techniques and management. A detailed questionnaire was distributed to 28 highly-experienced interventional cardiologists ('Authors') from 13 Asia-Pacific countries. The results were discussed at a meeting on patient selection, technical consideration, deployment practices and patient management. Potential patient benefits of Absorb compared to metallic DES, the learning curve for patient selection and preparation, device deployment, and subsequent patient management approaches are presented. Current practices are derived from guidelines optimized for European patients. Differences in approach exist in the Asia-Pacific context, including limited access to imaging and frequency of occurrence of complex lesions. Nevertheless, the use of the Absorb BVS ('Absorb') in certain Asia-Pacific countries has flourished and practices here are continuing to mature. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Is it the intervention or the students? using linear regression to control for student characteristics in undergraduate STEM education research.

PubMed

Theobald, Roddy; Freeman, Scott

2014-01-01

Although researchers in undergraduate science, technology, engineering, and mathematics education are currently using several methods to analyze learning gains from pre- and posttest data, the most commonly used approaches have significant shortcomings. Chief among these is the inability to distinguish whether differences in learning gains are due to the effect of an instructional intervention or to differences in student characteristics when students cannot be assigned to control and treatment groups at random. Using pre- and posttest scores from an introductory biology course, we illustrate how the methods currently in wide use can lead to erroneous conclusions, and how multiple linear regression offers an effective framework for distinguishing the impact of an instructional intervention from the impact of student characteristics on test score gains. In general, we recommend that researchers always use student-level regression models that control for possible differences in student ability and preparation to estimate the effect of any nonrandomized instructional intervention on student performance.

Hypnosis

MedlinePlus

... or dizziness Anxiety or distress Creation of false memories Use special caution before using hypnosis for age regression to help you relive earlier ... your memories or lead to creation of false memories. How you prepare You ... preparation to undergo hypnosis. But it's a good idea to wear comfortable ...

Fabrication of Semiconducting Methylammonium Lead Halide Perovskite Particles by Spray Technology

NASA Astrophysics Data System (ADS)

Ahmadian-Yazdi, Mohammad-Reza; Eslamian, Morteza

2018-01-01

In this "nano idea" paper, three concepts for the preparation of methylammonium lead halide perovskite particles are proposed, discussed, and tested. The first idea is based on the wet chemistry preparation of the perovskite particles, through the addition of the perovskite precursor solution to an anti-solvent to facilitate the precipitation of the perovskite particles in the solution. The second idea is based on the milling of a blend of the perovskite precursors in the dry form, in order to allow for the conversion of the precursors to the perovskite particles. The third idea is based on the atomization of the perovskite solution by a spray nozzle, introducing the spray droplets into a hot wall reactor, so as to prepare perovskite particles, using the droplet-to-particle spray approach (spray pyrolysis). Preliminary results show that the spray technology is the most successful method for the preparation of impurity-free perovskite particles and perovskite paste to deposit perovskite thin films. As a proof of concept, a perovskite solar cell with the paste prepared by the sprayed perovskite powder was successfully fabricated.

Fabrication of Semiconducting Methylammonium Lead Halide Perovskite Particles by Spray Technology.

PubMed

Ahmadian-Yazdi, Mohammad-Reza; Eslamian, Morteza

2018-01-10

In this "nano idea" paper, three concepts for the preparation of methylammonium lead halide perovskite particles are proposed, discussed, and tested. The first idea is based on the wet chemistry preparation of the perovskite particles, through the addition of the perovskite precursor solution to an anti-solvent to facilitate the precipitation of the perovskite particles in the solution. The second idea is based on the milling of a blend of the perovskite precursors in the dry form, in order to allow for the conversion of the precursors to the perovskite particles. The third idea is based on the atomization of the perovskite solution by a spray nozzle, introducing the spray droplets into a hot wall reactor, so as to prepare perovskite particles, using the droplet-to-particle spray approach (spray pyrolysis). Preliminary results show that the spray technology is the most successful method for the preparation of impurity-free perovskite particles and perovskite paste to deposit perovskite thin films. As a proof of concept, a perovskite solar cell with the paste prepared by the sprayed perovskite powder was successfully fabricated.

North rear, east part. Ramp leads to basement utility rooms ...

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

North rear, east part. Ramp leads to basement utility rooms and specimen preparation rooms. - San Bernardino Valley College, Life Science Building, 701 South Mount Vernon Avenue, San Bernardino, San Bernardino County, CA

Preparing Elementary Prospective Teachers to Teach Early Algebra

ERIC Educational Resources Information Center

Hohensee, Charles

2017-01-01

Researchers have argued that integrating early algebra into elementary grades will better prepare students for algebra. However, currently little research exists to guide teacher preparation programs on how to prepare prospective elementary teachers to teach early algebra. This study examines the insights and challenges that prospective teachers…

Engaging Local Communities in the Preparation of Teachers

ERIC Educational Resources Information Center

Zeichner, Ken

2015-01-01

The author critiques both major camps in the current debates about teacher education for their lack of attention to the role of local communities in preparing teachers. The current work at the University of Washington, Seattle, to engage local community members as mentors of teacher candidates is highlighted.

Preparing Preservice Teachers to Address Bullying through Cartoon Lessons

ERIC Educational Resources Information Center

Rule, Audrey C.; Logan, Stephanie R.; Kohler, Frank W.

2013-01-01

Students who qualify for special education services are at risk for being bullied because of their cognitive, emotional, behavioral, or physical differences. Currently, teachers are not effective enough in reducing bullying; better preservice teacher preparation in this area may help to alleviate the problem. The current study explored the effects…

Isotope dilution inductively coupled plasma mass spectrometry (ID ICP-MS) for the certification of lead and cadmium in environmental standard reference materials.

PubMed

Murphy, K E; Beary, E S; Rearick, M S; Vocke, R D

2000-10-01

Lead (Pb) and cadmium (Cd) have been determined in six new environmental standard reference materials (SRMs) using isotope dilution inductively coupled plasma mass spectrometry (ID ICP-MS). The SRMs are the following: SRM 1944, New York-New Jersey Waterway Sediment, SRMs 2583 and 2584, Trace Elements in Indoor Dust, Nominal 90 mg/kg and 10,000 mg/kg Lead, respectively, SRMs 2586 and 2587, Trace Elements in Soil Containing Lead from Paint, Nominal 500 mg/kg and 3,000 mg/kg Lead, respectively, and SRM 2782, Industrial Sludge. The capabilities of ID ICP-MS for the certification of Pb and Cd in these materials are assessed. Sample preparation and ratio measurement uncertainties have been evaluated. Reproducibility and accuracy of the established procedures are demonstrated by determination of gravimetrically prepared primary standard solutions and by comparison with isotope dilution thermal ionization mass spectrometry (ID TIMS). Material heterogeneity was readily demonstrated to be the dominant source of uncertainty in the certified values.

Dynamic filtration and static adsorption of lead ions in aqueous solution by use of blended polysulfone membranes with nano size MCM-41 particles coated by polyaniline.

PubMed

Toosi, Mohammad Reza; Emami, Mohammad Reza Sarmasti; Hajian, Sudeh

2018-05-11

MCM-41 mesopore was prepared by hydrothermal method and used for synthesis of polyaniline/MCM-41 nanocomposite via in situ polymerization. The nanocomposite was blended with polysulfone to prepare mixed matrix membrane in different content of nanocomposite by phase inversion method. Structural and surface properties of the samples were characterized by SEM, XRD, FTIR, AFM, TGA, BET, and zeta potential measurements. Effect of the nanocomposite content on the hydrophilicity, porosity, and permeability of the membrane was determined. Membrane performance was evaluated for removal of lead ions in dynamic filtration and static adsorption. The membranes were found as effective adsorptive filters for removal of lead ions via interactions between active sites of nanocomposite in membrane structure and lead ions during filtration. Results of batch experiments proved adsorptive mechanism of membranes for removal of lead ions with the maximum adsorption capacity of 19.6 mg/g.

34 CFR 668.8 - Eligible program.

Code of Federal Regulations, 2014 CFR

2014-07-01

... least a one-academic-year training program that leads to a certificate, or other nondegree recognized... quarter hours; (iii) Must provide undergraduate training that prepares a student for gainful employment in...) Provide undergraduate training that prepares a student for gainful employment in a recognized occupation...

34 CFR 668.8 - Eligible program.

Code of Federal Regulations, 2012 CFR

2012-07-01

... least a one-academic-year training program that leads to a certificate, or other nondegree recognized... quarter hours; (iii) Must provide undergraduate training that prepares a student for gainful employment in...) Provide undergraduate training that prepares a student for gainful employment in a recognized occupation...

34 CFR 668.8 - Eligible program.

Code of Federal Regulations, 2013 CFR

2013-07-01

... least a one-academic-year training program that leads to a certificate, or other nondegree recognized... quarter hours; (iii) Must provide undergraduate training that prepares a student for gainful employment in...) Provide undergraduate training that prepares a student for gainful employment in a recognized occupation...

Acid production potentials of massive sulfide minerals and lead-zinc mine tailings: a medium-term study.

PubMed

Çelebi, Emin Ender; Öncel, Mehmet Salim; Kobya, Mehmet

2018-01-01

Weathering of sulfide minerals is a principal source of acid generation. To determine acid-forming potentials of sulfide-bearing materials, two basic approaches named static and kinetic tests are available. Static tests are short-term, and easily undertaken within a few days and in a laboratory. In contrast, kinetic tests are long-term procedures and mostly carried out on site. In this study, experiments were conducted over a medium-term period of 2 months, not as short as static tests and also not as long as kinetic tests. As a result, pH and electrical conductivity oscillations as a function of time, acid-forming potentials and elemental contents of synthetically prepared rainwater leachates of massive sulfides and sulfide-bearing lead-zinc tailings from abandoned and currently used deposition areas have been determined. Although the lowest final pH of 2.70 was obtained in massive pyrite leachate, massive chalcopyrite leachate showed the highest titrable acidity of 1.764 g H 2 SO 4 /L. On the other hand, a composite of currently deposited mine tailings showed no acidic characteristic with a final pH of 7.77. The composite abandoned mine tailing leachate had a final pH of 6.70, close to the final pH of massive galena and sphalerite leachates, and produced a slight titrable acidity of 0.130 g H 2 SO 4 /L.

Measuring Lead Exposure in Infants, Children, and Other Sensitive Populations.

ERIC Educational Resources Information Center

National Academy of Sciences - National Research Council, Washington, DC.

Adverse health effects from exposure to lead are now recognized to be among industrialized society's most important health problems. This report, prepared by the National Research Council's Committee on Measuring Lead Exposure in Critical Populations, concurs with new findings issued by the Centers for Disease Control which state that lead…

Leading Organizational Change Is Like Climbing a Mountain

ERIC Educational Resources Information Center

Zimmerman, Judith

2004-01-01

Leading organizational change is like climbing a mountain. Transformational leaders must prepare to lead change, understand the process and nature of change, and provide the essential gear so that those involved can be successful. The author draws on the literature and personal experiences as a hiker and change leader to provide a guide for…

Perceptions of preparedness of LBS I teachers in the state of Illinois and graduates of Illinois State University's LBS I program to collaborate in teaching grade 7--12 math, science, and social science

NASA Astrophysics Data System (ADS)

Caldwell, Janet E.

The expectations for no child to be left behind are leading to increased emphasis on teaching math, science, and social science effectively to students with disabilities. This study utilized information collected from online surveys to examine how current LBS I teachers and individuals graduating from the Illinois State University teacher certification program in LBS I perceive their preparedness to teach these subjects. Participants provided information about coursework and life experiences, and they made suggestions about teacher preparation and professional development programs. Six key items forming the composite variable focused on level of preparation in (a) best practices, (b) selecting materials, (c) selecting objectives, (d) adapting instructional strategies, (e) planning lessons, and (f) and evaluating outcomes. Only 30 LBS I teachers of the 282 contacted by e-mail completed surveys. Of 115 graduates contacted, 71 participated in the original survey and 23 participated in a follow-up survey. Data were analyzed to learn more about the teachers' self-perceptions regarding preparedness to teach math, science, or social science. There was a correlation between perceived level of knowledge and the composite preparation variable for all subjects, but no correlation with length of teaching. Both groups indicated high school content courses were important in preparation to teach. Teachers also indicated collaboration and graduates indicated grade school learning. The most frequent recommendation for both teacher preparation and professional development was additional methods courses. A survey distributed to math, science, and social science teachers of Grades 7--12 asked about their perceptions of the preparedness of LBS I teachers to teach their area of content. Few surveys were completed for each subject so they were examined qualitatively. There was variability among participants, but generally the content area teachers rated themselves as more prepared than the LBS I teachers.

From the solution processing of hydrophilic molecules to polymer-phthalocyanine hybrid materials for ammonia sensing in high humidity atmospheres.

PubMed

Gaudillat, Pierre; Jurin, Florian; Lakard, Boris; Buron, Cédric; Suisse, Jean-Moïse; Bouvet, Marcel

2014-07-24

We have prepared different hybrid polymer-phthalocyanine materials by solution processing, starting from two sulfonated phthalocyanines, s-CoPc and CuTsPc, and polyvinylpyrrolidone (PVP), polyethylene glycol (PEG), poly(acrylic acid-co-acrylamide) (PAA-AM), poly(diallyldimethylammonium chloride) (PDDA) and polyaniline (PANI) as polymers. We also studied the response to ammonia (NH3) of resistors prepared from these sensing materials. The solvent casted films, prepared from s-CoPc and PVP, PEG and PAA-AM, were highly insulating and very sensitive to the relative humidity (RH) variation. The incorporation of s-CoPc in PDDA by means of layer-by-layer (LBL) technique allowed to stabilize the film, but was too insulating to be interesting. We also prepared PANI-CuTsPc hybrid films by LBL technique. It allowed a regular deposition as evidenced by the linear increase of the absorbance at 688 nm as a function of the number of bilayers. The sensitivity to ammonia (NH3) of PANi-CuTsPc resistors was very high compared to that of individual materials, giving up to 80% of current decrease when exposed to 30 ppm NH3. Contrarily to what happens with neutral polymers, in PANI, CuTsPc was stabilized by strong electrostatic interactions, leading to a stable response to NH3, whatever the relative humidity in the range 10%-70%. Thus, the synergy of PANI with ionic macrocycles used as counteranions combined with their simple aqueous solution processing opens the way to the development of new gas sensors capable of operating in real world conditions.

The Optimized Fabrication of Nanobubbles as Ultrasound Contrast Agents for Tumor Imaging.

PubMed

Cai, Wen Bin; Yang, Heng Li; Zhang, Jian; Yin, Ji Kai; Yang, Yi Lin; Yuan, Li Jun; Zhang, Li; Duan, Yun You

2015-09-03

Nanobubbles, which have the potential for ultrasonic targeted imaging and treatment in tumors, have been a research focus in recent years. With the current methods, however, the prepared uniformly sized nanobubbles either undergo post-formulation manipulation, such as centrifugation, after the mixture of microbubbles and nanobubbles, or require the addition of amphiphilic surfactants. These processes influence the nanobubble stability, possibly create material waste, and complicate the preparation process. In the present work, we directly prepared uniformly sized nanobubbles by modulating the thickness of a phospholipid film without the purification processes or the addition of amphiphilic surfactants. The fabricated nanobubbles from the optimal phospholipid film thickness exhibited optimal physical characteristics, such as uniform bubble size, good stability, and low toxicity. We also evaluated the enhanced imaging ability of the nanobubbles both in vitro and in vivo. The in vivo enhancement intensity in the tumor was stronger than that of SonoVue after injection (UCA; 2 min: 162.47 ± 8.94 dB vs. 132.11 ± 5.16 dB, P < 0.01; 5 min: 128.38.47 ± 5.06 dB vs. 68.24 ± 2.07 dB, P < 0.01). Thus, the optimal phospholipid film thickness can lead to nanobubbles that are effective for tumor imaging.

The Optimized Fabrication of Nanobubbles as Ultrasound Contrast Agents for Tumor Imaging

PubMed Central

Cai, Wen Bin; Yang, Heng Li; Zhang, Jian; Yin, Ji Kai; Yang, Yi Lin; Yuan, Li Jun; Zhang, Li; Duan, Yun You

2015-01-01

Nanobubbles, which have the potential for ultrasonic targeted imaging and treatment in tumors, have been a research focus in recent years. With the current methods, however, the prepared uniformly sized nanobubbles either undergo post-formulation manipulation, such as centrifugation, after the mixture of microbubbles and nanobubbles, or require the addition of amphiphilic surfactants. These processes influence the nanobubble stability, possibly create material waste, and complicate the preparation process. In the present work, we directly prepared uniformly sized nanobubbles by modulating the thickness of a phospholipid film without the purification processes or the addition of amphiphilic surfactants. The fabricated nanobubbles from the optimal phospholipid film thickness exhibited optimal physical characteristics, such as uniform bubble size, good stability, and low toxicity. We also evaluated the enhanced imaging ability of the nanobubbles both in vitro and in vivo. The in vivo enhancement intensity in the tumor was stronger than that of SonoVue after injection (UCA; 2 min: 162.47 ± 8.94 dB vs. 132.11 ± 5.16 dB, P < 0.01; 5 min: 128.38.47 ± 5.06 dB vs. 68.24 ± 2.07 dB, P < 0.01). Thus, the optimal phospholipid film thickness can lead to nanobubbles that are effective for tumor imaging. PMID:26333917

Measurement by ICP-MS of lead in plasma and whole blood of lead workers and controls.

PubMed Central

Schütz, A; Bergdahl, I A; Ekholm, A; Skerfving, S

1996-01-01

OBJECTIVES: To test a simple procedure for preparing samples for measurement of lead in blood plasma (P-Pb) and whole blood (B-Pb) by inductively coupled plasma mass spectrometry (ICP-MS), to measure P-Pb and B-Pb in lead workers and controls, and to evaluate any differences in the relation between B-Pb and P-Pb between people. METHODS: P-Pb and B-Pb were measured by ICP-MS in 43 male lead smelter workers and seven controls without occupational exposure to lead. For analysis, plasma and whole blood were diluted 1 in 4 and 1 in 9, respectively, with a diluted ammonia solution containing Triton-X 100 and EDTA. The samples were handled under routine laboratory conditions, without clean room facilities. RESULTS: P-Pb was measured with good precision (CV = 5%) even at concentrations present in the controls. Freeze storage of the samples had no effect on the results. The detection limit was 0.015 microgram/l. The P-Pb was 0.15 (range 0.1-0.3) microgram/l in controls and 1.2 (0.3-3.6) micrograms/l in lead workers, although the corresponding B-Pbs were 40 (24-59) micrograms/l and 281 (60-530) micrograms/l (1 microgram Pb/I = 4.8 nmol/l). B-Pb was closely associated with P-Pb (r = 0.90). The association was evidently non-linear; the ratio B-Pb/P-Pb decreased with increasing P-Pb. CONCLUSIONS: By means of ICP-MS and a simple dilution procedure, P-Pb may be measured accurately and with good precision down to concentrations present in controls. Contamination of blood at sampling and analysis is no major problem. With increasing P-Pb, the percentage of lead in plasma increases. In studies of lead toxicity, P-Pb should be considered as a complement to current indicators of lead exposure and risk. PMID:9038796

New graduate nurses' preparation for recognition and prevention of failure to rescue: A qualitative study.

PubMed

Herron, Elizabeth K

2018-01-01

To explore new graduate nurses' experiences with recognition and prevention of failure to rescue. Failure to rescue is recognised as a quality-of-care indicator, a core measure of nursing care in hospitals, and a determinant for staffing in acute care facilities. Clinical reasoning is an essential component in preventing failure to rescue and should be emphasised in nursing education and new graduate orientation. Many nurses graduate without the ability to use clinical reasoning in providing patient care which can lead to adverse patient outcomes. A descriptive phenomenological design was used. A purposive sample of 14 new graduate nurses from a nursing programme in the south-eastern USA, in practice for no more than eighteen months, was recruited. Individual one-on-one interviews were conducted from January-June 2016 and audio-recorded for accuracy. Data were evaluated using the consolidated criteria for reporting qualitative research (COREQ) guidelines. Recordings were professionally transcribed and reviewed. Using Giorgi's methods for data analysis, five main themes were discerned in the data: clinical preparation in school; experience with emergent situations; development of clinical reasoning; low confidence as a new graduate; and responding to emergencies. Within each theme, subthemes emerged. The words of the participants provided rich detail into the preparation of new graduate nurses and how nurse educators, managers and preceptors can better focus learning opportunities to prepare them for practice. Experiential learning combined with collaboration among education stakeholders will lead to a better prepared and more confident nursing work force. Better preparation and continued support of new graduate nurses lead to positive patient outcomes and more satisfaction with their choice of nursing as a profession. © 2017 John Wiley & Sons Ltd.

Magneto-acousto-electrical tomography: a potential method for imaging current density and electrical impedance.

PubMed

Haider, S; Hrbek, A; Xu, Y

2008-06-01

Primarily this report outlines our investigation on utilizing magneto-acousto-electrical-tomography (MAET) to image the lead field current density in volume conductors. A lead field current density distribution is obtained when a current/voltage source is applied to a sample via a pair of electrodes. This is the first time a high-spatial-resolution image of current density is presented using MAET. We also compare an experimental image of current density in a sample with its corresponding numerical simulation. To image the lead field current density, rather than applying a current/voltage source directly to the sample, we place the sample in a static magnetic field and focus an ultrasonic pulse on the sample to simulate a point-like current dipole source at the focal point. Then by using electrodes we measure the voltage/current signal which, based on the reciprocity theorem, is proportional to a component of the lead field current density. In the theory section, we derive the equation relating the measured voltage to the lead field current density and the displacement velocity caused by ultrasound. The experimental data include the MAET signal and an image of the lead field current density for a thin sample. In addition, we discuss the potential improvements for MAET especially to overcome the limitation created by the observation that no signal was detected from the interior of a region having a uniform conductivity. As an auxiliary we offer a mathematical formula whereby the lead field current density may be utilized to reconstruct the distribution of the electrical impedance in a piecewise smooth object.

The effect of an imposed current on the creep of tin silver copper interconnects

NASA Astrophysics Data System (ADS)

Kinney, Christopher Charles

There has been substantial work done on the properties of solder interconnects due to the global transition to lead free electronics. These interconnects create an electrical connection, which current will pass through for much of the interconnects' lifespan. As such, it is imperative in the testing of any solder alloy to examine the mechanical, thermal, and microstructural behavior of the interconnect while it is under an imposed current. The imposed current drives several internal effects that may impact the behavior of the interconnect; creating a complicated state within the interconnect. This thesis is the first study of the couple between current and mechanical properties of these interconnects. Idealized SnAgCu interconnects were made consisting of double-shear specimens that contained paired solder joints, 400x400mum in cross-section, 200mum in thickness on a Cu substrate. Different representative microstructures were prepared by pre-treating the interconnects via electromigration and isothermal aging. Samples were tested with and without an imposed current, and at a variety of temperatures. These tests consistently yielded two unexpected results. First, the relative increase in creep rate, for a given imposed current, is nearly the same over a range of temperatures and starting microstructures. Second, when tests are done at equivalent temperatures (to compensate for Joule heating) the creep rate is lower when under an imposed current than under isothermal conditions. To explain this phenomena, internal gradients within the interconnects were investigated. The temperature profile was shown to be constant at a given current density. Given constant temperature, and a microstructure that includes interfacial voids, the effect of the imposed current on the vacancy concentration was examined. It was found that the current depletes the joint of vacancies, lowering the average creep rate, and introducing observable heterogeneities in the creep pattern. This result was also found to be dependant on the specific locations of the voids, which act as vacancy sources or sinks. The usual Dom equation then provides a very useful basis for evaluating the change of creep rate with current. Actual microelectronic devices were also examined under an imposed current. Due to the complex geometry and composition of the samples, lower current densities were necessitated. As such, current induced effects were lessened, yet comparisons show similar behavior to the idealized interconnects. Our idealized model was applied to these devices, and yielded activation energies consistent with previous data. Finally, lifetime reliability projections were made for use in the future design of lead free microelectronic devices.

Upgrade of the gas flow control system of the resistive current leads of the LHC inner triplet magnets: Simulation and experimental validation

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

Perin, A.; Casas-Cubillos, J.; Pezzetti, M.

2014-01-29

The 600 A and 120 A circuits of the inner triplet magnets of the Large Hadron Collider are powered by resistive gas cooled current leads. The current solution for controlling the gas flow of these leads has shown severe operability limitations. In order to allow a more precise and more reliable control of the cooling gas flow, new flowmeters will be installed during the first long shutdown of the LHC. Because of the high level of radiation in the area next to the current leads, the flowmeters will be installed in shielded areas located up to 50 m away frommore » the current leads. The control valves being located next to the current leads, this configuration leads to long piping between the valves and the flowmeters. In order to determine its dynamic behaviour, the proposed system was simulated with a numerical model and validated with experimental measurements performed on a dedicated test bench.« less

IGF-I abuse in sport.

PubMed

Guha, Nishan; Dashwood, Alexander; Thomas, Nicholas J; Skingle, Alexander J; Sönksen, Peter H; Holt, Richard I G

2009-09-01

It is widely believed that growth hormone (GH) is abused by athletes for its anabolic and lipolytic effects. Many of the physiological effects of GH are mediated by the production of insulin-like growth factor-I (IGF-I). Both GH and IGF-I appear on the World Anti-Doping Agency list of prohibited substances. Little is known, however, about the prevalence of abuse with exogenous IGF-I. IGF-I has effects on carbohydrate, lipid and protein metabolism and some of these actions could prove beneficial to competitive athletes. No studies have demonstrated a positive effect of IGF-I on physical performance in healthy individuals but this has not yet been studied in appropriately designed trials. Two pharmaceutical preparations of IGF-I have recently become available for the treatment of growth disorders in children. This availability is likely to increase the prevalence of IGF-I abuse. Combining IGF-I with its binding protein IGFBP-3 in one preparation has the potential to reduce the side-effect profile but the adverse effects of long term IGF-I abuse are currently unknown. Detection of abuse with IGF-I is a major challenge for anti-doping authorities. It is extremely difficult to distinguish the exogenous recombinant form of the hormone from endogenously-produced IGF-I. One approach currently being investigated is based on measuring markers of GH and IGF-I action. This has already proved successful in the fight against GH abuse and, it is hoped, will subsequently lead to a similar test for detection of IGF-I abuse.

24 CFR 91.110 - Consultation; states.

Code of Federal Regulations, 2011 CFR

2011-04-01

... families, and homeless persons) during preparation of the consolidated plan. When preparing the portion of... with state or local health and child welfare agencies and examine existing data related to lead-based paint hazards and poisonings, including health department data on the addresses of housing units in...

Educational Leadership in an Online World: Connecting Students to Technology Responsibly, Safely, and Ethically

ERIC Educational Resources Information Center

Ribble, Mike; Miller, Teresa Northern

2013-01-01

The current gap in technology knowledge and lack of leadership preparation related to digital literacy for school environments can cause serious problems, as school leaders, parents, and broader social communities are currently realizing. The authors describe strategies for educational leaders to prepare their stakeholder groups for a digital…

Metallic CoS2 nanowire electrodes for high cycling performance supercapacitors

NASA Astrophysics Data System (ADS)

Ren, Ren; Faber, Matthew S.; Dziedzic, Rafal; Wen, Zhenhai; Jin, Song; Mao, Shun; Chen, Junhong

2015-12-01

We report metallic cobalt pyrite (CoS2) nanowires (NWs) prepared directly on current collecting electrodes, e.g., carbon cloth or graphite disc, for high-performance supercapacitors. These CoS2 NWs have a variety of advantages for supercapacitor applications. Because the metallic CoS2 NWs are synthesized directly on the current collector, the good electrical connection enables efficient charge transfer between the active CoS2 materials and the current collector. In addition, the open spaces between the sea urchin structure NWs lead to a large accessible surface area and afford rapid mass transport. Moreover, the robust CoS2 NW structure results in high stability of the active materials during long-term operation. Electrochemical characterization reveals that the CoS2 NWs enable large specific capacitance (828.2 F g-1 at a scan rate of 0.01 V s-1) and excellent long term cycling stability (0-2.5% capacity loss after 4250 cycles at 5 A g-1) for pseudocapacitors. This example of metallic CoS2 NWs for supercapacitor applications expands the opportunities for transition metal sulfide-based nanostructures in emerging energy storage applications.

Metallic CoS₂ nanowire electrodes for high cycling performance supercapacitors.

PubMed

Ren, Ren; Faber, Matthew S; Dziedzic, Rafal; Wen, Zhenhai; Jin, Song; Mao, Shun; Chen, Junhong

2015-12-11

We report metallic cobalt pyrite (CoS2) nanowires (NWs) prepared directly on current collecting electrodes, e.g., carbon cloth or graphite disc, for high-performance supercapacitors. These CoS2 NWs have a variety of advantages for supercapacitor applications. Because the metallic CoS2 NWs are synthesized directly on the current collector, the good electrical connection enables efficient charge transfer between the active CoS2 materials and the current collector. In addition, the open spaces between the sea urchin structure NWs lead to a large accessible surface area and afford rapid mass transport. Moreover, the robust CoS2 NW structure results in high stability of the active materials during long-term operation. Electrochemical characterization reveals that the CoS2 NWs enable large specific capacitance (828.2 F g(-1) at a scan rate of 0.01 V s(-1)) and excellent long term cycling stability (0-2.5% capacity loss after 4250 cycles at 5 A g(-1)) for pseudocapacitors. This example of metallic CoS2 NWs for supercapacitor applications expands the opportunities for transition metal sulfide-based nanostructures in emerging energy storage applications.

Intrinsic pinning and the critical current scaling of clean epitaxial Fe(Se,Te) thin films

NASA Astrophysics Data System (ADS)

Iida, Kazumasa; Hänisch, Jens; Reich, Elke; Kurth, Fritz; Hühne, Ruben; Schultz, Ludwig; Holzapfel, Bernhard; Ichinose, Ataru; Hanawa, Masafumi; Tsukada, Ichiro; Schulze, Michael; Aswartham, Saicharan; Wurmehl, Sabine; Büchner, Bernd

2013-03-01

We report on the transport properties of clean, epitaxial Fe(Se,Te) thin films prepared on Fe-buffered MgO (001) single crystalline substrates by pulsed laser deposition. Near Tc a steep slope of the upper critical field for H||ab was observed (74.1 T/K), leading to a very short out-of-plane coherence length, ξc(0), of 0.2 nm, yielding 2ξc(0)≈0.4nm. This value is shorter than the interlayer distance (0.605 nm) between the Fe-Se(Te) planes, indicative of modulation of the superconducting order parameter along the c axis. An inverse correlation between the power law exponent N of the electric field-current density(E-J) curve and the critical current density Jc has been observed at 4 K, when the orientation of H was close to the ab plane. These results prove the presence of intrinsic pinning in Fe(Se,Te). A successful scaling of the angular dependent Jc and the corresponding exponent N can be realized by the anisotropic Ginzburg Landau approach with appropriate Γ values 2˜3.5. The temperature dependence of Γ behaves almost identically to that of the penetration depth anisotropy.

Total Arsenic, Cadmium, and Lead Determination in Brazilian Rice Samples Using ICP-MS

PubMed Central

Buzzo, Márcia Liane; de Arauz, Luciana Juncioni; Carvalho, Maria de Fátima Henriques; Arakaki, Edna Emy Kumagai; Matsuzaki, Richard; Tiglea, Paulo

2016-01-01

This study is aimed at investigating a suitable method for rice sample preparation as well as validating and applying the method for monitoring the concentration of total arsenic, cadmium, and lead in rice by using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Various rice sample preparation procedures were evaluated. The analytical method was validated by measuring several parameters including limit of detection (LOD), limit of quantification (LOQ), linearity, relative bias, and repeatability. Regarding the sample preparation, recoveries of spiked samples were within the acceptable range from 89.3 to 98.2% for muffle furnace, 94.2 to 103.3% for heating block, 81.0 to 115.0% for hot plate, and 92.8 to 108.2% for microwave. Validation parameters showed that the method fits for its purpose, being the total arsenic, cadmium, and lead within the Brazilian Legislation limits. The method was applied for analyzing 37 rice samples (including polished, brown, and parboiled), consumed by the Brazilian population. The total arsenic, cadmium, and lead contents were lower than the established legislative values, except for total arsenic in one brown rice sample. This study indicated the need to establish monitoring programs for emphasizing the study on this type of cereal, aiming at promoting the Public Health. PMID:27766178

Optimization of cathodic arc deposition and pulsed plasma melting techniques for growing smooth superconducting Pb photoemissive films for SRF injectors

DOE PAGES

Nietubyc, Robert; Lorkiewicz, Jerzy; Sekutowicz, Jacek; ...

2018-02-14

Superconducting photoinjectors have a potential to be the optimal solution for moderate and high current cw operating free electron lasers. For this application, a superconducting lead (Pb) cathode has been proposed to simplify the cathode integration into a 1.3 GHz, TESLA-type, 1.6-cell long purely superconducting gun cavity. In the proposed design, a lead film several micrometres thick is deposited onto a niobium plug attached to the cavity back wall. Traditional lead deposition techniques usually produce very non-uniform emission surfaces and often result in a poor adhesion of the layer. A pulsed plasma melting procedure reducing the non-uniformity of the leadmore » photocathodes is presented. In order to determine the parameters optimal for this procedure, heat transfer from plasma to the film was first modelled to evaluate melting front penetration range and liquid state duration. The obtained results were verified by surface inspection of witness samples. The optimal procedure was used to prepare a photocathode plug, which was then tested in an electron gun. In conclusion, the quantum efficiency and the value of cavity quality factor have been found to satisfy the requirements for an injector of the European-XFEL facility.« less

Optimization of cathodic arc deposition and pulsed plasma melting techniques for growing smooth superconducting Pb photoemissive films for SRF injectors

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

Nietubyc, Robert; Lorkiewicz, Jerzy; Sekutowicz, Jacek

Superconducting photoinjectors have a potential to be the optimal solution for moderate and high current cw operating free electron lasers. For this application, a superconducting lead (Pb) cathode has been proposed to simplify the cathode integration into a 1.3 GHz, TESLA-type, 1.6-cell long purely superconducting gun cavity. In the proposed design, a lead film several micrometres thick is deposited onto a niobium plug attached to the cavity back wall. Traditional lead deposition techniques usually produce very non-uniform emission surfaces and often result in a poor adhesion of the layer. A pulsed plasma melting procedure reducing the non-uniformity of the leadmore » photocathodes is presented. In order to determine the parameters optimal for this procedure, heat transfer from plasma to the film was first modelled to evaluate melting front penetration range and liquid state duration. The obtained results were verified by surface inspection of witness samples. The optimal procedure was used to prepare a photocathode plug, which was then tested in an electron gun. In conclusion, the quantum efficiency and the value of cavity quality factor have been found to satisfy the requirements for an injector of the European-XFEL facility.« less

Teaching Food Preparation with Video Flash Cards

ERIC Educational Resources Information Center

Scholl, Jan F.; Cason, Katherine; Cherry, Tom

2004-01-01

Food preparation skills are needed to prepare low-cost, nutritious meals that meet current dietary recommendations. Research indicates that many youth and adults can read a recipe for ingredients, but they often do not know basic food preparation techniques such as how to broil, fold, dredge, baste and other cooking methods. To address the need to…

Report of the Committee To Study Preparation of the Workforce. Item #7.

ERIC Educational Resources Information Center

Illinois State Board of Higher Education, Springfield.

This report examines workforce preparation in the state of Illinois within the following general areas: (1) the current and future workforce preparation needs of business; (2) higher education's role in relation to the roles of secondary education, business, labor, and government in providing workforce preparation programs; and (3) the…

Social Justice Means Just Us White People: The Diversity Paradox in Teacher Education

ERIC Educational Resources Information Center

Juarez, Brenda G.; Smith, Darron T.; Hayes, Cleveland

2008-01-01

The paradox of the nation's teacher preparation programs is that "everything" is about diversity and social justice in the preparation of teachers and, simultaneously, "nothing" is about diversity and social justice in the preparation of teachers. Across teacher education, there is wide consensus that preparing current and prospective teachers to…

Which Field Experiences Best Prepare Future School Leaders? An Analysis of Kentucky's Principal Preparation Program

ERIC Educational Resources Information Center

Dodson, Richard L.

2014-01-01

This paper examines the effectiveness of field experiences in preparing school principals for the exigencies of the job. Current school principals throughout Kentucky were surveyed regarding their perceptions of the utility and comparative effectiveness of field experiences in the principal preparation program (PPP) each attended. Surveys were…

Response of Primary Explosives to Gaseous Discharges in an Improved Approaching-Electrode Electrostatic Sensitivity Apparatus

DTIC Science & Technology

1976-10-01

and Identify by block number) This report describes an improved, approaching-needle electrostatic sensitivity apparatus as well as the...category. Thus, basic lead styphnate, RD1333 lead azide, dextrinated lead azide and tetracene all ignited. But, as expected, tetryl, PETN, superfine PETN... dextrinated lead azide obtained using the same apparatus and procedure and conducted at the same time. Sample Preparation, Electrode Replacement, and

Preparative separation of grape skin polyphenols by high-speed counter-current chromatography.

PubMed

Luo, Lanxin; Cui, Yan; Zhang, Shuting; Li, Lingxi; Li, Yuanyuan; Zhou, Peiyu; Sun, Baoshan

2016-12-01

To develop an efficient method for large preparation of various individual polyphenols from white grape skins (Fernão Pires; Vitis vinifera) by preparative high-speed counter-current chromatography (HSCCC) and preparative-HPLC, an optimized preparative HSCCC condition with two-phase solvent system composed of Hex-EtOAc-H2O (1:50:50, v/v) was used to separate grape skin polyphenols into various fractions. Both the tail-head and head-tail elution modes were used with a flow rate of 3.0ml/min and a rotary speed of 950rpm. Afterwards, a preparative-HPLC separation was applied to isolate individual polyphenols in each of the fractions from HSCCC. Total of 7 fractions (Fraction A to G) were obtained from grape skin extract by HSCCC. After preparative-HPLC isolation, fifteen individual compounds were obtained, most of which presented high yields and purity (all over 90%). The HSCCC method followed with preparative-HPLC appeared to be convenient and economical, constituting an efficient strategy for the isolation of grape skin polyphenols. Copyright © 2016 Elsevier Ltd. All rights reserved.

Experience of 12 kA / 16 V SMPS during the HTS Current Leads Test

NASA Astrophysics Data System (ADS)

Panchal, P.; Christian, D.; Panchal, R.; Sonara, D.; Purwar, G.; Garg, A.; Nimavat, H.; Singh, G.; Patel, J.; Tanna, V.; Pradhan, S.

2017-04-01

As a part of up gradation plans in SST-1 Tokamak, one pair of 3.3 kA rated prototype hybrid current leads were developed using Di-BSCCO as High Temperature Superconductors (HTS) and the copper heat exchanger. In order to validate the manufacturing procedure prior to go for series production of such current leads, it was recommended to test these current leads using dedicated and very reliable DC switch mode power supply (SMPS). As part of test facility, 12 kA, 16 VDC programmable SMPS was successfully installed, commissioned and tested. This power supply has special features such as modularity, N+1 redundancy, very low ripple voltage, precise current measurements with Direct Current Current Transformer, CC/CV modes with auto-crossover and auto-sequence programming. As a part of acceptance of this converter, A 5.8 mΩ water-cooled resistive dummy load and PLC based SCADA system is designed, developed for commissioning of power supply. The same power supply was used for the testing of the prototype HTS current leads. The paper describes the salient features and experience of state-of-art of power supply and results obtained from this converter during the HTS current leads test.

Monitoring and seasonal forecasting of meteorological droughts

NASA Astrophysics Data System (ADS)

Dutra, Emanuel; Pozzi, Will; Wetterhall, Fredrik; Di Giuseppe, Francesca; Magnusson, Linus; Naumann, Gustavo; Barbosa, Paulo; Vogt, Jurgen; Pappenberger, Florian

2015-04-01

Near-real time drought monitoring can provide decision makers valuable information for use in several areas, such as water resources management, or international aid. Unfortunately, a major constraint in current drought outlooks is the lack of reliable monitoring capability for observed precipitation globally in near-real time. Furthermore, drought monitoring systems requires a long record of past observations to provide mean climatological conditions. We address these constraints by developing a novel drought monitoring approach in which monthly mean precipitation is derived from short-range using ECMWF probabilistic forecasts and then merged with the long term precipitation climatology of the Global Precipitation Climatology Centre (GPCC) dataset. Merging the two makes available a real-time global precipitation product out of which the Standardized Precipitation Index (SPI) can be estimated and used for global or regional drought monitoring work. This approach provides stability in that by-passes problems of latency (lags) in having local rain-gauge measurements available in real time or lags in satellite precipitation products. Seasonal drought forecasts can also be prepared using the common methodology and based upon two data sources used to provide initial conditions (GPCC and the ECMWF ERA-Interim reanalysis (ERAI) combined with either the current ECMWF seasonal forecast or a climatology based upon ensemble forecasts. Verification of the forecasts as a function of lead time revealed a reduced impact on skill for: (i) long lead times using different initial conditions, and (ii) short lead times using different precipitation forecasts. The memory effect of initial conditions was found to be 1 month lead time for the SPI-3, 3 to 4 months for the SPI-6 and 5 months for the SPI-12. Results show that dynamical forecasts of precipitation provide added value, a skill similar to or better than climatological forecasts. In some cases, particularly for long SPI time scales, it is very difficult to improve on the use of climatological forecasts. However, results presented regionally and globally pinpoint several regions in the world where drought onset forecasting is feasible and skilful.

Leadership skills for the California electric utility industry: A qualitative study

NASA Astrophysics Data System (ADS)

Hubbell, Michael

The purpose of this qualitative study was to determine the skills and knowledge necessary for leaders in the California electric utility industry in 2020. With rapid industry changes, skills to effectively lead and stay competitive are undetermined. Leaders must manage an increasingly hostile social and political environment, incorporate new technology, and deal with an aging workforce and infrastructure. Methodology. This study utilized a qualitative case study design to determine the factors that influence the skills leaders will require in 2020. It incorporated the perspectives of current electric utility leaders while looking with a future lens. Findings. Interviews were conducted with transmission and distribution (T&D) directors at 3 investor-owned public electric utilities headquartered in California. The questions followed an open-ended format to gather responses as perceived by electric utility leaders for each research question category: overall skills, aging workforce, regulation, technology, and leading younger generations. The research resulted in 18 major themes: 5 for overall skills, 3 for aging workforce, 4 for regulation, 3 for technology, and 3 for leading younger generations. Conclusions. The study identified leadership skills including the ability to embrace, leverage, and stay current with technology; understand and provide a clear vision for the future; increase creativity; manage the next set of workers; motivate during a time of great change; prepare for knowledge transfer and change in workforce culture; manage regulatory expectations; expand potential utility opportunities; leverage "big data"; allow worker collaboration; and understand what drives younger generations. Recommendations. California-based electric utility leaders can remain effective by implementing key strategies identified herein. Further research could examine perspectives of additional utility leaders who lead in organizational units outside of T&D, expand the research to include additional states, and/or demonstrate how to acquire the identified skills. It is also recommended that a replication of this study be undertaken to include a perspective and analysis of union or "field" workers.

Environmentally Compliant Disposal Method for Heavy Metal Containing Propellants

NASA Technical Reports Server (NTRS)

Decker, M. W.; Erickson, E. D.; Byrd, E. R.; Crispin, K. W. R.; Ferguson, B. W.

2000-01-01

ABSTRACT An environmentally friendly, cost effective technology has been developed and demonstrated by a team of Naval Air Warfare Center and Lockheed Martin personnel to dispose of Shillelagh solid rocket motor propellants. The Shillelagh is a surface to surface anti-tank weapon approaching the end of its service life. The current demilitarization process employs open detonation, but the presence of lead stearate in the N5 propellant grain motivated the need for the development of an environmentally friendly disposal method. Contained burning of the propellant followed by propellant exhaust processing was chosen as the disposal methodology. The developmental test bed, completed in February 1998, is inexpensive and transportable. Contained burning of Shillelagh propellants posed two technical hurdles: 1) removal of the sub micron lead and cadmium particulate generated during combustion, and 2) secondary combustion of the significant quantifies of carbon monoxide and hydrogen. A firing chamber with a stepped nozzle, air injection, and active ignition was developed to combust the carbon monoxide and hydrogen in real time. The hot gases and particulates from the combustion process are completely contained within a gas holder. The gases are subsequently cooled and routed through a treatment facility to remove the heavy metal particulate. Results indicate that the lead and cadmium particulates are removed below their respective detection limits (2 micro-g/cu m & 0.2 micro-g/cu m) of the analytical procedures employed and that the carbon monoxide and hydrogen levels have been reduced well below the lower flammability limits. Organic concentrations, principally benzene, are I ppm or less. A semi-automated machine has been developed which can rapidly prepare Shillelagh missiles for the contained burn facility. This machine allows the contained burn technology to be more competitive with current open bum open detonation disposal rates.

Lead Selenide Colloidal Quantum Dot Solar Cells Achieving High Open-Circuit Voltage with One-Step Deposition Strategy.

PubMed

Zhang, Yaohong; Wu, Guohua; Ding, Chao; Liu, Feng; Yao, Yingfang; Zhou, Yong; Wu, Congping; Nakazawa, Naoki; Huang, Qingxun; Toyoda, Taro; Wang, Ruixiang; Hayase, Shuzi; Zou, Zhigang; Shen, Qing

2018-06-18

Lead selenide (PbSe) colloidal quantum dots (CQDs) are considered to be a strong candidate for high-efficiency colloidal quantum dot solar cells (CQDSCs) due to its efficient multiple exciton generation. However, currently, even the best PbSe CQDSCs can only display open-circuit voltage ( V oc ) about 0.530 V. Here, we introduce a solution-phase ligand exchange method to prepare PbI 2 -capped PbSe (PbSe-PbI 2 ) CQD inks, and for the first time, the absorber layer of PbSe CQDSCs was deposited in one step by using this PbSe-PbI 2 CQD inks. One-step-deposited PbSe CQDs absorber layer exhibits fast charge transfer rate, reduced energy funneling, and low trap assisted recombination. The champion large-area (active area is 0.35 cm 2 ) PbSe CQDSCs fabricated with one-step PbSe CQDs achieve a power conversion efficiency (PCE) of 6.0% and a V oc of 0.616 V, which is the highest V oc among PbSe CQDSCs reported to date.

Graphene-Silver-Induced Self-Polarized PVDF-Based Flexible Plasmonic Nanogenerator Toward the Realization for New Class of Self Powered Optical Sensor.

PubMed

Sinha, Tridib Kumar; Ghosh, Sujoy Kumar; Maiti, Rishi; Jana, Santanu; Adhikari, Basudam; Mandal, Dipankar; Ray, Samit K

2016-06-22

Plasmonic characteristics of graphene-silver (GAg) nanocomposite coupled with piezoelectric property of Poly(vinylidene fluoride) (PVDF) have been utilized to realize a new class of self-powered flexible plasmonic nanogenerator (PNG). A few layer graphene has been prepared in a facile and cost-effective method and GAg doped PVDF hybrid nanocomposite (PVGAg) is synthesized in a one-pot method. The PNG exhibits superior piezoelectric energy conversion efficiency (∼15%) under the dark condition. The plasmonic behavior of GAg nanocomposite makes the PNG highly responsive to the visible light illumination that leads to ∼50% change in piezo-voltage and ∼70% change in piezo-current, leading to enhanced energy conversion efficiency up to ∼46.6%. The piezoelectric throughput of PNG (e.g., capacitor charging performance) has been monitored during the detection of the different wavelengths of visible light illumination and showed maximum selectivity to the green light. The simultaneous mechanical energy harvesting and visible-light detection capabilities of the PNG are attractive for futuristic self-powered optoelectronic smart sensors and devices.

Insulin Management Strategies for Exercise in Diabetes.

PubMed

Zaharieva, Dessi P; Riddell, Michael C

2017-10-01

There is no question that regular exercise can be beneficial and lead to improvements in overall cardiovascular health. However, for patients with diabetes, exercise can also lead to challenges in maintaining blood glucose balance, particularly if patients are prescribed insulin or certain oral hypoglycemic agents. Hypoglycemia is the most common adverse event associated with exercise and insulin therapy, and the fear of hypoglycemia is also the greatest barrier to exercise for many patients. With the appropriate insulin dose adjustments and, in some cases, carbohydrate supplementation, blood glucose levels can be better managed during exercise and in recovery. In general, insulin strategies that help facilitate weight loss with regular exercise and recommendations around exercise adjustments to prevent hypoglycemia and hyperglycemia are often not discussed with patients because the recommendations can be complex and may differ from one individual to the next. This is a review of the current published literature on insulin dose adjustments and starting-point strategies for patients with diabetes in preparation for safe exercise. Copyright © 2017 Diabetes Canada. Published by Elsevier Inc. All rights reserved.

Electrical and optical properties of sol-gel derived La modified PbTiO 3 thin films

NASA Astrophysics Data System (ADS)

Chopra, Sonalee; Sharma, Seema; Goel, T. C.; Mendiratta, R. G.

2004-09-01

Lanthanum modified lead titanate (Pb 1- xLa xTi 1- x/4 O 3) PLT x ( x=0.08 i.e. PLT8) sol-gel derived thin films have been prepared on indium tin oxide (ITO) coated glass and quartz substrates using lead acetate trihydrate, lanthanum acetate hydrate and titanium isopropoxide as precursors along with 2-methoxyethanol as solvent and acetic acid as catalyst by spin coating method. The microstructure and surface morphology of the films annealed at 650 °C have been studied by X-ray diffraction technique and atomic force microscope (AFM). XRD has shown a single phase with tetragonal structure and AFM images have confirmed a smooth and crack-free surface with low surface roughness. The dependence of leakage current on applied voltage show ohmic behavior at low field region with a space charge conduction mechanism at high fields. The wavelength dispersion curve of thin films obtained from the transmission spectrum of thin films show that the films have high optical transparency in the visible region.

Optimizing the performance of catalytic traps for hydrocarbon abatement during the cold-start of a gasoline engine.

PubMed

Puértolas, B; Navlani-García, M; García, T; Navarro, M V; Lozano-Castelló, D; Cazorla-Amorós, D

2014-08-30

A key target to reduce current hydrocarbon emissions from vehicular exhaust is to improve their abatement under cold-start conditions. Herein, we demonstrate the potential of factorial analysis to design a highly efficient catalytic trap. The impact of the synthesis conditions on the preparation of copper-loaded ZSM-5 is clearly revealed by XRD, N2 sorption, FTIR, NH3-TPD, SEM and TEM. A high concentration of copper nitrate precursor in the synthesis improves the removal of hydrocarbons, providing both strong adsorption sites for hydrocarbon retention at low temperature and copper oxide nanoparticles for full hydrocarbon catalytic combustion at high temperature. The use of copper acetate precursor leads to a more homogeneous dispersion of copper oxide nanoparticles also providing enough catalytic sites for the total oxidation of hydrocarbons released from the adsorption sites, although lower copper loadings are achieved. Thus, synthesis conditions leading to high copper loadings jointly with highly dispersed copper oxide nanoparticles would result in an exceptional catalytic trap able to reach superior hydrocarbon abatement under highly demanding operational conditions. Copyright © 2014 Elsevier B.V. All rights reserved.

Test results of 12/18 kA ReBCO coated conductor current leads

NASA Astrophysics Data System (ADS)

Kovalev, I. A.; Surin, M. I.; Naumov, A. V.; Novikov, M. S.; Novikov, S. I.; Ilin, A. A.; Polyakov, A. V.; Scherbakov, V. I.; Shutova, D. I.

2017-07-01

A pair of hybrid current leads (brass + stacked & soldered ReBCO tapes) rated for 12 kA in steady state and for up to 18 kA at pulsed over current conditions was designed, developed and tested at NRC ;Kurchatov Institute; (NRC ;KI;). During the experiment at LN2 temperature, the current leads (CLs) were successfully charged with 18 kA at 100 A/s ramp rate. To date, as far as we know, this is the highest current capacity achieved for 2G HTS current leads. The feasibility of ;stack-and-soldering technique; for 10 kA+ class coated conductor CLs for accelerators and fusion was demonstrated. This paper gives an overview of the leads design and presents the preliminary test results. Detailed studies of magnetic properties and current sharing process for the stacked and staggered HTS joints are also reported.

Preparative high-speed counter-current chromatography for purification of shikonin from the Chinese medicinal plant Lithospermum erythrorhizon.

PubMed

Lu, Hai-Tao; Jiang, Yue; Chen, Feng

2004-01-09

The bioactive compound shikonin was successfully isolated and purified from the crude extract of the traditional Chinese medicinal plant Lithospermum erythrorhizon Sieb. et Zucc. by preparative high-speed counter-current chromatography (HSCCC). The preparative HSCCC was performed using a two-phase solvent system composed of n-hexane-ethylacetate-ethanol-water (16:14:14:5 (v/v)). A total amount of 19.6 mg of shikonin at 98.9% purity was obtained from 52 mg of the crude extract (containing 38.9% shikonin) with 96.9% recovery. The preparative isolation and purification of shikonin by HSCCC was completed in 200 min in a one-step separation.

A Thermal Stability Test for Primary Explosive Stab Sensitizers: Study of the Thermal and Hydrolytic Stability of 2-Picryl-5-Nitrotetrazole,

DTIC Science & Technology

1984-02-01

have been described previously (2]. The actual batch used was designated Batch D and was identical to that referred to as Batch C in Reference [2...Tetrazene was type RD1357 prepared at Materials Research Laboratories. The batch used was designated Batch 10/83(A). Lead Azide was type RD1343 and was...Preparation of Experimental Detonators Eperimental detonators were prepared in mild steel tubes, 6 mm o.d., 3.2 mm i.d., length 6 mm, prepared from

Quantitative aspects of microchip isotachophoresis for high precision determination of main components in pharmaceuticals.

PubMed

Hradski, Jasna; Chorváthová, Mária Drusková; Bodor, Róbert; Sabo, Martin; Matejčík, Štefan; Masár, Marián

2016-12-01

Although microchip electrophoresis (MCE) is intended to provide reliable quantitative data, so far there is only limited attention paid to these important aspects. This study gives a general overview of key aspects to be followed to reach high-precise determination using isotachophoresis (ITP) on the microchip with conductivity detection. From the application point of view, the procedure for the determination of acetate, a main component in the pharmaceutical preparation buserelin acetate, was developed. Our results document that run-to-run fluctuations in the sample injection volume limit the reproducibility of quantitation based on the external calibration. The use of a suitable internal standard (succinate in this study) improved the repeatability of the precision of acetate determination from six to eight times. The robustness of the procedure was studied in terms of impact of fluctuations in various experimental parameters (driving current, concentration of the leading ions, pH of the leading electrolyte and buffer impurities) on the precision of the ITP determination. The use of computer simulation programs provided means to assess the ITP experiments using well-defined theoretical models. A long-term validity of the calibration curves on two microchips and two MCE equipments was verified. This favors ITP over other microchip electrophoresis techniques, when chip-to-chip or equipment-to-equipment transfer of the analytical method is required. The recovery values in the range of 98-101 % indicate very accurate determination of acetate in buserelin acetate, which is used in the treatment of hormone-dependent tumors. This study showed that microchip ITP is suitable for reliable determination of main components in pharmaceutical preparations.

Extended release of hyaluronic acid from hydrogel contact lenses for dry eye syndrome.

PubMed

Maulvi, Furqan A; Soni, Tejal G; Shah, Dinesh O

2015-01-01

Current dry eye treatment includes delivering comfort enhancing agents to the eye via eye drops, but low residence time of eye drops leads to low bioavailability. Frequent administration leads to incompliance in patients, so there is a great need for medical device such as contact lenses to treat dry eye. Studies in the past have demonstrated the efficacy of hyaluronic acid (HA) in the treatment of dry eyes using eye drops. In this paper, we present two methods to load HA in hydrogel contact lenses, soaking method and direct entrapment. The contact lenses were characterized by studying their optical and physical properties to determine their suitability as extended wear contact lenses. HA-laden hydrogel contact lenses prepared by soaking method showed release up to 48 h with acceptable physical and optical properties. Hydrogel contact lenses prepared by direct entrapment method showed significant sustained release in comparison to soaking method. HA entrapped in hydrogels resulted in reduction in % transmittance, sodium ion permeability and surface contact angle, while increase in % swelling. The impact on each of these properties was proportional to HA loading. The batch with 200-μg HA loading showed all acceptable values (parameters) for contact lens use. Results of cytotoxicity study indicated the safety of hydrogel contact lenses. In vivo pharmacokinetics studies in rabbit tear fluid showed dramatic increase in HA mean residence time and area under the curve with lenses in comparison to eye drop treatment. The study demonstrates the promising potential of delivering HA through contact lenses for the treatment of dry eye syndrome.

The Intercostal NMJ Assay: a new alternative to the conventional LD50 assay for the determination of the therapeutic potency of botulinum toxin preparations.

PubMed

Huber, Alexander; France, Richard M; Riccalton-Banks, Lisa; McLaren, Jane; Cox, Helen; Quirk, Robin A; Shakesheff, Kevin M; Thompson, David; Panjwani, Naveed; Shipley, Sarah; Pickett, Andy

2008-05-01

Therapeutic botulinum neurotoxin type A preparations have found an increasing number of clinical uses for a large variety of neuromuscular disorders and dermatological conditions. The accurate determination of potency in the clinical application of botulinum toxins is critical to ensuring clinical efficacy and safety, and is currently achieved by using a lethal dose (LD50) assay in mice. Ethical concerns and operational constraints associated with this assay have prompted the development of alternative assay systems that could potentially lead to its replacement. As one such alternative, we describe the development and evaluation of a novel ex vivo assay (the Intercostal Neuromuscular Junction [NMJ] Assay), which uses substantially fewer animals and addresses ethical concerns associated with the LD50 assay. The assay records the decay of force from electrically-stimulated muscle tissue sections in response to the toxin, and thus combines the important mechanisms of receptor binding, translocation, and the enzymatic action of the toxin molecule. Toxin application leads to a time-related and dose-related reduction in contractile force. A regression model describing the relationship between the applied dose and force decay was determined statistically, and was successfully tested as able to correctly predict the potency of an unknown sample. The tissue sections used were found to be highly reproducible, as determined through the innervation pattern and the localisation of NMJs in situ. Furthermore, the efficacy of the assay protocol to successfully deliver the test sample to the cellular target sites, was critically assessed by using molecular tracer molecules.

Development of Hydrogen Education Programs for Government Officials

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

Baxter, Shannon; Keller, Russ

1. Subcontractor/Technical Subject Matter Expert (Tasks 1-3) 2. Technical lead for LFG cleanup and hydrogen production systems Support for Feasibility Study 3. Technical Lead for Feasibility Study Coordination of site preparation activities for all project equipment 4. Host site

Preparing Healthy Young Children for Hospitalization: A Rationale and Proposal.

ERIC Educational Resources Information Center

Poster, Elizabeth C.

1984-01-01

Proposes a precrisis curriculum for nursery and elementary schools to prepare healthy young children for hospitalization as an alternative to current preadmission preparation programs. Key elements include such stress-immunization techniques as systematic desensitization, modeling, and rehearsal. (AS)

Negotiations: Try a Pragmatic Approach.

ERIC Educational Resources Information Center

Prenn, Kathryn J.; Coughlin, John T.

1986-01-01

With adequate preparation, effort, and commitment, the school system's collective bargaining process can become an opportunity for management and employee organizations to resolve significant concerns. This paper recommends nine steps for a pragmatic approach to negotiations. (1) Prepare: Preparation includes reviewing the current collective…

Synthesis of Lead Sulfide Nanoparticles by Chemical Precipitation Method

NASA Astrophysics Data System (ADS)

Chongad, L. S.; Sharma, A.; Banerjee, M.; Jain, A.

2016-10-01

Lead sulfide (PbS) nanoparticles were prepared by chemical precipitation method (CPM) with the assistance of H2S gas. The microstructure and morphology of the synthesized nanoparticles have been investigated using X-ray diffraction (XRD) and transmission electron microscopy (TEM). The XRD patterns of the PbS nanoparticles reveal formation of cubic phase. To investigate the quality of prepared nanoparticles, the particles size, lattice constant, strain, dislocation density etc. have been determined using XRD. TEM images reveal formation of cubic nanoparticles and the particle size determined from TEM images agree well with those from XRD.

Effect of Polymer Matrix on the Structure and Electric Properties of Piezoelectric Lead Zirconatetitanate/Polymer Composites

PubMed Central

Li, Rui; Zhou, Jun; Liu, Hujun; Pei, Jianzhong

2017-01-01

Piezoelectric lead zirconatetitanate (PZT)/polymer composites were prepared by two typical polymer matrixes using the hot-press method. The micromorphology, microstructure, dielectric properties, and piezoelectric properties of the PZT/polymer composites were characterized and investigated. The results showed that when the condition of frequency is 103 Hz, the dielectric and piezoelectric properties of PZT/poly(vinylidene fluoride) were both better than that of PZT/polyvinyl chloride (PVC). When the volume fraction of PZT was 50%, PZT/PVDF prepared by the hot-press method had better comprehensive electric property. PMID:28805730

Preparing Teachers for Diversity: A Literature Review and Implications from Community-Based Teacher Education

ERIC Educational Resources Information Center

Yuan, Huanshu

2018-01-01

This study reviewed current issues in preparing qualified teachers for increasing diverse student populations in the U.S. and in other multicultural and multiethnic countries. Based on the framework of community-based and multicultural teacher education, this literature review paper analyzed issues and problems existed in the current curriculum,…

Emerging Research Leaders' Preparation and Practices

ERIC Educational Resources Information Center

Rohwer, Debbie

2015-01-01

There is a need for a study to provide in-depth information about emerging researcher leaders in terms of how they prepared for their career and how they utilize time and resources in their current positions in order to have continued research success. The purpose of the current study was to describe emerging research leaders' graduate school…

Lead poisoning from metallic teapots traditionally used by North African populations

NASA Astrophysics Data System (ADS)

Petit, D.; Claeys, F.; Sykes, C.; Noefnet, Y.

2003-05-01

When children are found in Brussels with high blood lead level (PbB), over 200 μg/l, the LICB conducts an environmental study to determine the source of lead responsible for the intoxication. The study consists in filling a risk questionnaire, followed by a family interview and an investigation of the housing. Standard samples of lead sources are collected (dust, paint chips and water). If this first investigation is negative, further investigations are carried out. In one particular case of lead intoxication, which concerned in a family of Moroccan origin, no standard source could be identified. Our case study finally concluded that tea infusions prepared in a traditional North-African metallic teapot had caused lead poisoning. This investigation began with a single intoxication case of a young child (age 18 months, PbB 495 μg/l). However, it quickly appeared that 18 other members of his family had also been contaminated (PbB 3 ranged from 155 to 455 μg/l). Faced with this relative unknown lead hazard, the LICB decided to collect and analyse the leachability and content in lead of this kind of vessel (8 teapots from different origin were tested). The lead contents measured in the metallic teapots ranged from 3.2% to 84%. The lead concentrations found in brewed tea varied from 230 to 5070 μg/l in function of the lead teapot content and of number of daily preparation.

Crystal Growth and Other Materials Physical Researches in Space Environment

NASA Astrophysics Data System (ADS)

Pan, Mingxiang

Material science researches in space environment are based on reducing the effects of buoyancy driven transport, the effects of atomic oxygen, radiation, extremes of heat and cold and the ultrahigh vacuum, so as to unveil the underlying fundamental phenomena, lead maybe to new potential materials or new industrial processes and develop space techniques. Currently, research program on materials sciences in Chinese Manned Space Engineering (CMSE) is going on. More than ten projects related to crystal growth and materials processes are selected as candidates to be executed in Shenzhou spacecraft, Tiangong Space Laboratory and Chinese Space Station. In this talk, we will present some examples of the projects, which are being prepared and executed in the near future flight tasks. They are both basic and applied research, from discovery to technology.

Photodynamic characterization and optimization using multifunctional nanoparticles for brain cancer treatment

NASA Astrophysics Data System (ADS)

Herrmann, Kristen; Lee Koo, Yong-Eun; Orringer, Daniel A.; Sagher, Oren; Philbert, Martin; Kopelman, Raoul

2013-03-01

Photosensitizer-conjugated polyacrylamide nanoparticles were prepared for in vivo characterization of the minimally invasive and localized treatment of photodynamic therapy (PDT) on brain tumors. By incorporating a variety of nanoparticle matrixes, choosing methylene blue as a photosensitizer, and targeting the nanoparticle by the use of F3 peptide we have made nanoparticle-based PDT improvements to current PDT efficiency. Quantitative growth patterns were determined through visual observation of the tumorigenic response to various treatments by the use of an animal cranial window model. PDT treatments with methylene blue-polyacrylamide (MB-PAA) nanoparticles produced significant adjournment of tumor growth over control groups, clearly demonstrating the advantages of nanoparticle-based PDT agents for the eradication of local tumors, leading to the potential palliation of the advancing disease.

Gravity survey of groundwater characterization at Labuan Basin

NASA Astrophysics Data System (ADS)

Handayani, L.; Wardhana, D. D.; Hartanto, P.; Delinom, R.; Sudaryanto; Bakti, H.; Lubis, RF

2018-02-01

Labuan groundwater basin currently has an abundance of water. As a deltaic area of Lada Bay, groundwater supply comes from local precipitation and also from recharge region in mountain ranges surrounding. However, Labuan has been experiencing a fast economic development with high population and tourism industry growth. Such progress would lead to the increase of water consumption. A comprehensive groundwater management should be prepared for possible future problems. Therefore, a groundwater investigation is a necessary step towards that purpose. Gravity method was applied to identify the regional condition of the basement. The assessment of deep buried basin and basement relationship using gravity data is a challenge in groundwater investigation, but previous studies had indicated the efficiency of the method to obtain basic information and can be used as a foundation for more advanced studies.

Tour Guide Robots: An Integrated Research and Design Platform to Prepare Engineering and Technology Students

ERIC Educational Resources Information Center

Yelamarthi, Kumar

2016-01-01

Many interesting research and design questions occur at the intersections of traditional disciplines, yet most coursework and research programs for undergraduate engineering students are focused on one discipline. This leads to underutilization of the potential in better preparing students through multidisciplinary projects. Identifying this…

Preparation for Transnationalism: Changes in China's Top Secondary Schools

ERIC Educational Resources Information Center

Gordon, June A.; Liu, Xiangyan

2014-01-01

This article argues that new international programs within public secondary schools in China represent a vigorous and legitimatized approach to meeting the demands of newly affluent Chinese families for pre-collegiate education that equals the best international standards and constitutes preparation for higher education at the leading universities…

How Prepared Are Psychiatry Residents for Treating Nicotine Dependence?

ERIC Educational Resources Information Center

Prochaska, Judith J.; Fromont, Sebastien C.; Hall, Sharon M.

2005-01-01

Objective: Nicotine dependence is the most prevalent substance abuse disorder among adult psychiatric patients and a leading cause of death and disability. The authors examined the extent to which psychiatry residents are prepared to treat nicotine dependence in clinical practice. Methods: Residents from five psychiatry residency programs in…

Principal Preparedness for Leading in Demographically Changing Schools: Where Is the Social Justice Training?

ERIC Educational Resources Information Center

Miller, Catherine M.; Martin, Barbara N.

2015-01-01

This multi-case study sought to construct meaning using a cultural capital lens in relation to educational leadership preparation programs building the capacities of social justice leaders in demographically changing schools. Data revealed principals' perceptions about preparation, expectations and general beliefs and assumptions related to…

Values and Context: Taiwan Principal Preparation and Practice from an American Perspective

ERIC Educational Resources Information Center

Vogel, Linda R.

2015-01-01

This qualitative study explores the preparation and practice of school leaders in Taiwan based on indepth interviews and observations with six Taiwan school directors serving geographically diverse student populations. The journey leading to school leadership and the challenges that this representative group of educational leaders face are…

Developing the Instructional Specification. Monograph Number 12.

ERIC Educational Resources Information Center

Gerlach, Vernon S.; And Others

Analysis of a film script that makes the learner identify and distinguish between statements of observation and statements of inference leads an instructor (or other program writer) step by step through the processes of preparing an instructional specification--a blue-print for preparing powerful self-instructional materials. There are four parts…

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

Tani, Yasuo; Shikoh, Eiji, E-mail: shikoh@elec.eng.osaka-cu.ac.jp; Teki, Yoshio

We report the spin-pump-induced spin transport properties of a pentacene film prepared by thermal evaporation. In a palladium(Pd)/pentacene/Ni{sub 80}Fe{sub 20} tri-layer sample, a pure spin-current is generated in the pentacene layer by the spin-pumping of Ni{sub 80}Fe{sub 20}, which is independent of the conductance mismatch problem in spin injection. The spin current is absorbed into the Pd layer, converted into a charge current with the inverse spin-Hall effect in Pd, and detected as an electromotive force. This is clear evidence for the pure spin current at room temperature in pentacene films prepared by thermal evaporation.

Development of a compact HTS lead unit for the SC correction coils of the SuperKEKB final focusing magnet system

NASA Astrophysics Data System (ADS)

Zong, Zhanguo; Ohuchi, Norihito; Tsuchiya, Kiyosumi; Arimoto, Yasushi

2016-09-01

Forty-three superconducting (SC) correction coils with maximum currents of about 60 A are installed in the SuperKEKB final focusing magnet system. Current leads to energize the SC correction coils should have an affordable heat load and fit the spatial constraints in the service cryostat where the current leads are installed. To address the requirements, design optimization of individual lead was performed with vapor cooled current lead made of a brass material, and a compact unit was designed to accommodate eight current leads together in order to be installed with one port in the service cryostat. The 2nd generation high temperature SC (HTS) tape was adopted and soldered at the cold end of the brass current lead to form a hybrid HTS lead structure. A prototype of the compact lead unit with HTS tape was constructed and tested with liquid helium (LHe) environment. This paper presents a cryogenic measurement system to simulate the real operation conditions in the service cryostat, and analysis of the experimental results. The measured results showed excellent agreement with the theoretical analysis and numerical simulation. In total, 11 sets of the compact HTS lead units were constructed for the 43 SC correction coils at KEK. One set from the mass production was tested in cryogenic conditions, and exhibited the same performance as the prototype. The compact HTS lead unit can feed currents to four SC correction coils simultaneously with the simple requirement of controlling and monitoring helium vapor flow, and has a heat load of about 0.762 L/h in terms of LHe consumption.

Managing acute pain in patients who report lactose intolerance: the safety of an old excipient re-examined.

PubMed

Mill, Deanna; Dawson, Jessica; Johnson, Jacinta Lee

2018-05-01

Lactose intolerance is exceedingly common, reportedly affecting up to 70% of the world's population, leading to both abdominal and systemic symptoms. Current treatment focuses predominantly on restricting dietary consumption of lactose. Given lactose is one of the most commonly used excipients in the pharmaceutical industry, consideration must be given to the lactose content and therefore safety of pharmaceutical preparations prescribed for patients with lactose intolerance. This article summarizes the current literature examining the likelihood of inducing adverse effects through the administration of lactose-containing pharmaceutical preparations in patients reporting lactose intolerance, describes how to assess this risk on an individual patient basis and reviews suitable analgesic options for this population. A case study is presented detailing a patient reporting lactose intolerance who insists on treatment with the lactose-free product codeine/ibuprofen (Nurofen Plus) rather than other codeine-free analgesics. It is important to assess the likelihood of lactose as an excipient inducing symptoms in this scenario, as reluctance to cease codeine could suggest codeine dependence, an issue that is becoming increasingly common in countries such as Australia and Canada. Given codeine dependence is associated with serious sequelae including hospitalization and death, the patient must either be reassured the lactose component in their prescribed analgesics will not induce symptoms or an alternative treatment strategy must be confirmed. General recommendations applying theory from the literature to the management of acute pain in lactose-intolerant patients are discussed and specific treatment options are outlined. Although large inter-individual variability is reported, most lactose-intolerant patients can tolerate the small quantities of lactose found in pharmaceutical preparations. Cumulative lactose exposure can be assessed in patients taking multiple medications while also consuming lactose in the diet. In those sensitive to small quantities of lactose, lactase supplements can be trailed. Additionally, for the analgesic drug classes employed for the management of acute pain, lactose-free formulations, including most oral liquids and dispersible tablets and some oral tablets and capsules, are available.

Corrosive microenvironments at lead solder surfaces arising from galvanic corrosion with copper pipe.

PubMed

Nguyen, Caroline K; Stone, Kendall R; Dudi, Abhijeet; Edwards, Marc A

2010-09-15

As stagnant water contacts copper pipe and lead solder (simulated soldered joints), a corrosion cell is formed between the metals in solder (Pb, Sn) and the copper. If the resulting galvanic current exceeds about 2 μA/cm(2), a highly corrosive microenvironment can form at the solder surface, with pH < 2.5 and chloride concentrations at least 11 times higher than bulk water levels. Waters with relatively high chloride tend to sustain high galvanic currents, preventing passivation of the solder surface, and contributing to lead contamination of potable water supplies. The total mass of lead corroded was consistent with predictions based on the galvanic current, and lead leaching to water was correlated with galvanic current. If the concentration of sulfate in the water increased relative to chloride, galvanic currents and associated lead contamination could be greatly reduced, and solder surfaces were readily passivated.

Current status of integrating information technologies into the clinical research enterprise within US academic health centers: strategic value and opportunities for investment.

PubMed

Turisco, Fran; Keogh, Diane; Stubbs, Connie; Glaser, John; Crowley, William F

2005-12-01

Little information exists about the incorporation of information technologies (ITs) into clinical research processes within US academic health centers (AHCs). Therefore, we queried a group of 37 leading AHCs regarding their current status and future plans in clinical research IT. The survey specifically inquired about the presence or absence of basic infrastructure and IT support requirements; individual applications needed to support study preparation, study conduct, and its administrative support; and integration of data from basic research, clinical trials, and the clinical information systems increasingly used in health care delivery. Of the 37 AHCs, 78% responded. All strongly agreed that a "state-of-the-art" clinical research IT program would be ideal today and will be essential tomorrow. Nonetheless, no AHC currently has an IT solution that even approached this ideal. No AHC reported having all of the essential management foundations (ie, a coherent vision, an overall strategy, a governance structure, and a dedicated budget) necessary to launch and sustain a truly successful implementation of a cohesive clinical research IT platform. Many had achieved breakthroughs in individual aspects of clinical research IT, for example, adverse event reporting systems or consent form templates. However, overall implementation of IT to support clinical research is uneven and insufficient. These data document a substantial gap in clinical research IT investments in leading US AHCs. Linking the clinical research IT enterprise with its clinical operations in a meaningful fashion remains a crucial strategic goal of AHCs. If they are to continue to serve as the "translational research engines" that our society expects, AHCs must recognize this gap and allocate substantial resource deployment to remedying this situation.

Dielectric Dispersion, Diffuse Phase Transition, and Electrical Properties of BCT-BZT Ceramics Sintered at a Low-Temperature

NASA Astrophysics Data System (ADS)

Tian, Yongshang; Gong, Yansheng; Meng, Dawei; Li, Yuanjian; Kuang, Boya

2015-08-01

Lead-free ceramics 0.50Ba0.9Ca0.1TiO3-0.50BaTi1- x Zr x O3 (BCT-BZT) were prepared via sintering BCT and BZT nanoparticles, which were synthesized using a modified Pechini polymeric precursor method, at a low temperature of 1260°C. The relative densities of the ceramics prepared with different zirconium contents ( x) were all above 95.3%, reaching a maximum of 97% when x = 0.08. X-ray diffraction results confirmed the onset of phase transformation from orthorhombic to rhombohedral symmetry with increasing zirconium contents, and the polymorphic phase transition was observed at x = 0.10. The dielectric dispersion, diffuse phase transition (DPT), and relaxor-like ferroelectric characteristics as a function of zirconium content were thoroughly studied. Optimum physical properties, remnant polarization ( P r) = 16.4 μC/cm2, piezoelectric constant ( d 33) = ~240 pC/N, and electromechanical coupling factor ( k p) = 0.22, were obtained at x = 0.10. The findings of the current DPT behavior study of BCT-BZT ceramics are believed to be insightful to the development of ferroelectric materials.

Superhard self-lubricating AlMgB14 films for microelectromechanical devices

NASA Astrophysics Data System (ADS)

Tian, Y.; Bastawros, A. F.; Lo, C. C. H.; Constant, A. P.; Russell, A. M.; Cook, B. A.

2003-10-01

Performance and reliability of microelectromechanical system (MEMS) components can be enhanced dramatically through the incorporation of protective thin-film coatings. Current-generation MEMS devices prepared by the lithographie-galvanoformung-abformung (LIGA) technique employ transition metals such as Ni, Cu, Fe, or alloys thereof, and hence lack stability in oxidizing, corrosive, and/or high-temperature environments. Fabrication of a superhard self-lubricating coating based on a ternary boride compound AlMgB14 described in this letter has great potential in protective coating technology for LIGA microdevices. Nanoindentation tests show that the hardness of AlMgB14 films prepared by pulsed laser deposition ranges from 45 GPa to 51 GPa, when deposited at room temperature and 573 K, respectively. Extremely low friction coefficients of 0.04-0.05, which are thought to result from a self-lubricating effect, have also been confirmed by nanoscratch tests on the AlMgB14 films. Transmission electron microscopy studies show that the as-deposited films are amorphous, regardless of substrate temperature; however, analysis of Fourier transform infrared spectra suggests that the higher substrate temperature facilitates the formation of the B12 icosahedral framework, therefore leading to the higher hardness.

Si@void@C Nanofibers Fabricated Using a Self-Powered Electrospinning System for Lithium-Ion Batteries.

PubMed

Han, Yu; Zou, Jingdian; Li, Zhen; Wang, Wenqiang; Jie, Yang; Ma, Jinming; Tang, Bin; Zhang, Qi; Cao, Xia; Xu, Shengming; Wang, Zhong Lin

2018-05-22

In recent years, research in lithium-ion batteries (LIBs) has been focused on improving their performance in various ways, such as density, capacity, and lifetime, but little attention has been paid to the energy consumption cost in the manufacturing process. Herein, we report an energy-efficient preparation method of anode materials for LIBs based on a self-powered electrospinning system without an external power source, which consists of a rotatory triboelectric nanogenerator (r-TENG), a power management circuit, and an electrospinning unit. By harvesting kinetic energy from a handle rotation, the r-TENG is able to fully power the electrospinning system to fabricate nanofibers for LIBs. The as-obtained Si@void@C nanofibers present outstanding cyclic performance with a discharge capacity of 1045.2 mA h g -1 after 100 cycles and 88% capacity retention, along with an excellent high rate capacity of 400 mA h g -1 at a current density of 5 A g -1 , which are completely comparable with those made by commercial electrospinning equipment. Our study demonstrates an innovative and distinct approach toward an extremely low-cost preparation procedure of electrode materials, leading to a great breakthrough for the LIB production industry.

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

Glosser, D.; Kutchko, B.; Benge, G.

Foamed cement is a critical component for wellbore stability. The mechanical performance of a foamed cement depends on its microstructure, which in turn depends on the preparation method and attendant operational variables. Determination of cement stability for field use is based on laboratory testing protocols governed by API Recommended Practice 10B-4 (API RP 10B-4, 2015). However, laboratory and field operational variables contrast considerably in terms of scale, as well as slurry mixing and foaming processes. Here in this paper, laboratory and field operational processes are characterized within a physics-based framework. It is shown that the “atomization energy” imparted by themore » high pressure injection of nitrogen gas into the field mixed foamed cement slurry is – by a significant margin – the highest energy process, and has a major impact on the void system in the cement slurry. There is no analog for this high energy exchange in current laboratory cement preparation and testing protocols. Quantifying the energy exchanges across the laboratory and field processes provides a basis for understanding relative impacts of these variables on cement structure, and can ultimately lead to the development of practices to improve cement testing and performance.« less

Soft tissue-preserving computer-aided impression: a novel concept using ultrasonic 3D-scanning.

PubMed

Vollborn, Thorsten; Habor, Daniel; Pekam, Fabrice Chuembou; Heger, Stefan; Marotti, Juliana; Reich, Sven; Wolfart, Stefan; Tinschert, Joachim; Radermacher, Klaus

2014-01-01

Subgingival preparations are often affected by blood and saliva during impression taking, regardless of whether one is using compound impression techniques or intraoral digital scanning methods. The latter are currently based on optical principles and therefore also need clean and dry surfaces. In contrast, ultrasonic waves are able to non-invasively penetrate gingiva, saliva, and blood, leading to decisive advantages, as cleaning and drying of the oral cavity becomes unnecessary. In addition, the application of ultrasound may facilitate the detection of subgingival structures without invasive manipulation, thereby reducing the risk of secondary infection and treatment time, and increasing patient comfort. Ultrasound devices commonly available for medical application and for the testing of materials are only suitable to a limited extent, as their resolution, precision, and design do not fulfill the requirements for intraoral scanning. The aim of this article is to describe the development of a novel ultrasound technology that enables soft tissue-preserving digital impressions of preparations for the CAD/CAM-based production of dental prostheses. The concept and development of the high-resolution ultrasound technique and the corresponding intraoral scanning system, as well as the integration into the CAD/CAM process chain, is presented.

Development of Imiquimod-Loaded Mucoadhesive Films for Oral Dysplasia

PubMed Central

Ramineni, S.K.; Cunningham, L.L.; Dziubla, T.D.; Puleo, D.A.

2013-01-01

Oral squamous dysplasia, which can usually be readily visualized as leukoplakia during an oral examination and confirmed by histology, is often considered a premalignant condition. Current treatments, however, focus on the final stages of disease, and treatments such as surgery can lead to postoperative disabilities. Hence, this study was designed to develop a noninvasive, mucoadhesive drug delivery system loaded with an immune response modifier, imiquimod, as treatment for precancerous dysplastic lesions. Blends of polyvinylpyrrolidone and carboxymethylcellulose were used to prepare mucoadhesive films that were backed with poly(ethylene-co-vinyl acetate). Because of the hydrophobic nature of imiquimod, four methods of loading (sonication, linoleic acid, 2-hydroxypropyl-β-cyclodextrin, and acetate buffer) were compared. The formation of imiquimod-cyclodextrin complexes and their solubility was studied by differential scanning calorimetry and phase solubility studies. All films achieved sustained release of drug for three hours except for those prepared by linoleic acid. The high solubility of imiquimod in acetate buffer facilitated high loading capability and greater release (68%) of drug than did the other formulations (approximately 40%). In summary, a noninvasive and local approach with the potential to treat precancerous lesions may be achieved by this described mucoadhesive drug delivery system. PMID:23192692

End-preparation assessments and tests for compounded sterile preparations.

PubMed

McElhiney, Linda F

2013-01-01

Outsourcing has become a necessity to obtain sterile products that are currently on backorder. Because of the expense of outsourcing sterile compounding, pharmacy leadership in health systems are now considering the option of insourcing and batch preparing compounded sterile preparations, which can be a viable option for a health system. It can significantly decrease drug-spending costs, and the pharmacy has a complete record of the compounding process. The key to preparing high-quality, safe, sterile preparations and meeting United States Pharmacopeia standards is end-preparation assessments and tests.

Pure hydroxyapatite phantoms for the calibration of in vivo X-ray fluorescence systems of bone lead and strontium quantification.

PubMed

Da Silva, Eric; Kirkham, Brian; Heyd, Darrick V; Pejović-Milić, Ana

2013-10-01

Plaster of Paris [poP, CaSO4·(1)/(2) H2O] is the standard phantom material used for the calibration of in vivo X-ray fluorescence (IVXRF)-based systems of bone metal quantification (i.e bone strontium and lead). Calibration of IVXRF systems of bone metal quantification employs the use of a coherent normalization procedure which requires the application of a coherent correction factor (CCF) to the data, calculated as the ratio of the relativistic form factors of the phantom material and bone mineral. Various issues have been raised as to the suitability of poP for the calibration of IVXRF systems of bone metal quantification which include its chemical purity and its chemical difference from bone mineral (a calcium phosphate). This work describes the preparation of a chemically pure hydroxyapatite phantom material, of known composition and stoichiometry, proposed for the purpose of calibrating IVXRF systems of bone strontium and lead quantification as a replacement for poP. The issue with contamination by the analyte was resolved by preparing pure Ca(OH)2 by hydroxide precipitation, which was found to bring strontium and lead levels to <0.7 and <0.3 μg/g Ca, respectively. HAp phantoms were prepared from known quantities of chemically pure Ca(OH)2, CaHPO4·2H2O prepared from pure Ca(OH)2, the analyte, and a HPO4(2-) containing setting solution. The final crystal structure of the material was found to be similar to that of the bone mineral component of NIST SRM 1486 (bone meal), as determined by powder X-ray diffraction spectrometry.

Formation of Intermetallic Phases in Al-Sc Alloys Prepared by Molten Salt Electrolysis at Elevated Temperatures

NASA Astrophysics Data System (ADS)

Wang, Zengjie; Guan, Chunyang; Liu, Qiaochu; Xue, Jilai

Molten salts electrolysis method to prepare Al-RE alloys has attracted increasing attention recently. CaCl2 and Na3AlF6 were the most often used melts for this purpose. In this work, Al-Sc alloys prepared by electrolytic deposition process in both CaCl2 and Na3AlF6 melts were investigated, respectively. It was found that Sc distributes almost uniformly and Sc contents increase with increasing current intensity in both melts. Current efficiency was measured for comparison among various current densities applied. The alloy products were analyzed using XRD and SEM, where the formation behaviors of Al-Sc intermetallics were investigated in details. The experimental and theoretical results demonstrate that Al3Sc and Al0.968Sc0.032 are the major precipitates in the Al-Sc alloys prepared by molten electrolysis. The results are useful for selection and optimization of the molten salts compositions and the parameters of electrolysis operation.

Lead iron phosphate glass as a containment medium for disposal of high-level nuclear waste

DOEpatents

Boatner, Lynn A.; Sales, Brian C.

1989-01-01

Lead-iron phosphate glasses containing a high level of Fe.sub.2 O.sub.3 for use as a storage medium for high-level radioactive nuclear waste. By combining lead-iron phosphate glass with various types of simulated high-level nuclear waste, a highly corrosion resistant, homogeneous, easily processed glass can be formed. For corroding solutions at 90.degree. C., with solution pH values in the range between 5 and 9, the corrosion rate of the lead-iron phosphate nuclear waste glass is at least 10.sup.2 to 10.sup.3 times lower than the corrosion rate of a comparable borosilicate nuclear waste glass. The presence of Fe.sub.2 O.sub.3 in forming the lead-iron phosphate glass is critical. Lead-iron phosphate nuclear waste glass can be prepared at temperatures as low as 800.degree. C., since they exhibit very low melt viscosities in the 800.degree. to 1050.degree. C. temperature range. These waste-loaded glasses do not readily devitrify at temperatures as high as 550.degree. C. and are not adversely affected by large doses of gamma radiation in H.sub.2 O at 135.degree. C. The lead-iron phosphate waste glasses can be prepared with minimal modification of the technology developed for processing borosilicate glass nuclear wasteforms.

Birth-Kindergarten Licensure Graduates' Perceptions of Their Current Practices and Pre-Service Preparation Relative to Individualization Strategies for Young Children

ERIC Educational Resources Information Center

Gillis, Margaret C.

2011-01-01

The purpose of this study was to examine the current practices and pre-service preparation of recent graduates of North Carolina Birth-Kindergarten (B-K) teacher licensure programs related to individualizing curriculum and instruction for children. Participants were 142 individuals who graduated from B-K licensure programs in four-year…

Facile preparation of MnO2 nanorods and evaluation of their supercapacitive characteristics

NASA Astrophysics Data System (ADS)

Aghazadeh, Mustafa; Asadi, Maryam; Maragheh, Mohammad Ghannadi; Ganjali, Mohammad Reza; Norouzi, Parviz; Faridbod, Farnoush

2016-02-01

The first time pulsed base (OH-) electrogeneration to the cathodic electrodeposition of MnO2 in nitrate bath was applied and MnO2 nanorods were obtained. The deposition experiments were performed under a pulse current mode with typical on-times and off-times (ton = 10 ms and toff = 50 ms) and a peak current density of 2 mA cm-2 (Ia = 2 mA cm-2). The structural characterization with XRD and FTIR revealed that the prepared MnO2 is composed of both α and γ phases. Morphological evaluations through SEM and TEM revealed that the prepared MnO2 contains nanorods of relative uniform structures (with an average diameter of 50 nm). The electrochemical measurements through cyclic voltammetry and charge-discharge techniques revealed that the prepared MnO2 nanostructures reveal an excellent capacitive behavior with specific capacitance values of 242, 167 and 98 F g-1 under the applied current densities of 2, 5 and 10 A g-1, respectively. Also, excellent long-term cycling stabilities of 94.8%, 89.1%, and 76.5% were observed after 1000 charge-discharge cycles at the current densities of 2, 5 and 10 A g-1.

[Sample preparation and bioanalysis in mass spectrometry].

PubMed

Bourgogne, Emmanuel; Wagner, Michel

2015-01-01

The quantitative analysis of compounds of clinical interest of low molecular weight (<1000 Da) in biological fluids is currently in most cases performed by liquid chromatography-mass spectrometry (LC-MS). Analysis of these compounds in biological fluids (plasma, urine, saliva, hair...) is a difficult task requiring a sample preparation. Sample preparation is a crucial part of chemical/biological analysis and in a sense is considered the bottleneck of the whole analytical process. The main objectives of sample preparation are the removal of potential interferences, analyte preconcentration, and converting (if needed) the analyte into a more suitable form for detection or separation. Without chromatographic separation, endogenous compounds, co-eluted products may affect a quantitative method in mass spectrometry performance. This work focuses on three distinct parts. First, quantitative bioanalysis will be defined, different matrices and sample preparation techniques currently used in bioanalysis by mass spectrometry of/for small molecules of clinical interest in biological fluids. In a second step the goals of sample preparation will be described. Finally, in a third step, sample preparation strategies will be made either directly ("dilute and shoot") or after precipitation.

Phosphate glasses for radioactive, hazardous and mixed waste immobilization

DOEpatents

Cao, H.; Adams, J.W.; Kalb, P.D.

1998-11-24

Lead-free phosphate glass compositions are provided which can be used to immobilize low level and/or high level radioactive wastes in monolithic waste forms. The glass composition may also be used without waste contained therein. Lead-free phosphate glass compositions prepared at about 900 C include mixtures from about 1--6 mole % iron (III) oxide, from about 1--6 mole % aluminum oxide, from about 15--20 mole % sodium oxide or potassium oxide, and from about 30--60 mole % phosphate. The invention also provides phosphate, lead-free glass ceramic glass compositions which are prepared from about 400 C to about 450 C and which includes from about 3--6 mole % sodium oxide, from about 20--50 mole % tin oxide, from about 30--70 mole % phosphate, from about 3--6 mole % aluminum oxide, from about 3--8 mole % silicon oxide, from about 0.5--2 mole % iron (III) oxide and from about 3--6 mole % potassium oxide. Method of making lead-free phosphate glasses are also provided. 8 figs.

High-temperature superconducting current leads

NASA Astrophysics Data System (ADS)

Hull, J. R.

1992-07-01

The use of high-temperature superconductors (HTSs) for current leads to deliver power to devices at liquid helium temperature is near commercial realization. The use of HTSs in this application has the potential to reduce refrigeration requirements and helium boiloff to values significantly lower than the theoretical best achievable with conventional leads. Considerable advantage is achieved by operating these leads with an intermediate temperature heat sink. The HTS part of the lead can be made from pressed and sintered powder. Powder-in-tube fabrication is also possible, however, the normal metal part of the lead acts as a thermal short and cannot provide much stabilization without increasing the refrigeration required. Lead stability favors designs with low current density. Such leads can be manufactured with today's technology, and lower refrigeration results from the same allowable burnout time. Higher current densities result in lower boiloff for the same lead length, but bumout times can be very short. In comparing experiment to theory, the density of helium vapor needs to be accounted for in calculating the expected boiloff. For very low-loss leads, two-dimensional heat transfer and the state of the dewar near the leads may play a dominant role in lead performance.

Tailoring magnetic PLGA nanoparticles suitable for doxorubicin delivery

NASA Astrophysics Data System (ADS)

Tansık, Gülistan; Yakar, Arzu; Gündüz, Ufuk

2014-01-01

One of the main problems of current cancer chemotherapy is the lack of selectivity of anti-cancer drugs to tumor cells, which leads to systemic toxicity and adverse side effects. In order to overcome these limitations, researches on controlled drug delivery systems have gained much attention. Nanoscale-based drug delivery systems provide tumor targeting. Among many types of nanocarriers, superparamagnetic nanoparticles with their biocompatible polymer coatings can be targeted to an intented site by an external magnetic field. Thus, the drug can be carried to the targeted site safely. The aim of this study is to prepare poly( dl-lactic- co-glycolic acid) (PLGA)-coated magnetic nanoparticles and load anti-cancer drug, doxorubicin to them. For this purpose, magnetite (Fe3O4) iron oxide nanoparticles were synthesized as a magnetic core material (MNP) and then coated with oleic acid. Oleic acid-coated MNP (OA-MNP) was encapsulated into PLGA. Effects of different OA-MNP/PLGA ratios on magnetite entrapment efficiency were investigated. Doxorubicin-loaded magnetic polymeric nanoparticles (DOX-PLGA-MNP) were prepared. After the characterization of prepared nanoparticles, their cytotoxic effects on MCF-7 cell line were studied. PLGA-coated magnetic nanoparticles (PLGA-MNP) had a proper size and superparamagnetic character. The highest magnetite entrapment efficiency of PLGA-MNP was estimated as 63 % at 1:8 ratio. Cytotoxicity studies of PLGA-MNP did not indicate any notable cell death between the concentration ranges of 2 and 125 μg/ml. Drug loading efficiency was estimated as 32 %, and it was observed that DOX-PLGA-MNP showed significant cytotoxicity on MCF-7 cells compared to PLGA-MNP. The results showed that prepared nanoparticles have desired size and superparamagnetic characteristics without serious toxic effects on cells. These nanoparticles may be suitable for targeted drug delivery applications.

Nanoencapsulation of water-soluble drug, lamivudine, using a double emulsion spray-drying technique for improving HIV treatment

NASA Astrophysics Data System (ADS)

Tshweu, Lesego; Katata, Lebogang; Kalombo, Lonji; Swai, Hulda

2013-11-01

Current treatments available for human immunodeficiency virus, namely antiretrovirals, do not completely eradicate the virus from the body, leading to life-time commitment. Many antiretrovirals suffer drawbacks from toxicity and unpleasant side effects, causing patience non-compliance. To minimize challenges associated with the antiretrovirals, biodegradable nanoparticles used as drug delivery systems hold tremendous potential to enhance patience compliance. The main objective of this work was to load lamivudine (LAM) into poly(epsilon-caprolactone) (PCL) nanoparticles. LAM is a hydrophilic drug with low plasma half-life of 5-7 h and several unpleasant side effects. LAM was nanoencapsulated into PCL polymer via the double emulsion spray-drying method. Formulation parameters such as the effect of solvent, excipient and drug concentration were optimized for the synthesis of the nanoparticles. Spherical nanoparticles with an average size of 215 ± 3 nm and polydispersity index (PDI) of 0.227 ± 0.01 were obtained, when ethyl acetate and lactose were used in the preparation. However, dichloromethane presented sizes larger than 454 ± 11 nm with PDI of more than 0.4 ± 0.05, irrespective of whether lactose or trehalose was used in the preparation. Some of the nanoparticles prepared with trehalose resulted in crystal formation. UV spectroscopy showed encapsulation efficiency ranging from 68 ± 4 to 78 ± 4 % for LAM depending on the starting drug concentration. Fourier transform infrared spectroscopy and X-ray diffraction confirmed the possibility of preparing amorphous PCL nanoparticles containing LAM. Drug release extended for 4 days in pH 1.3, pH 4.5 and pH 6.8. These results indicated that LAM-loaded PCL nanoparticles show promise for controlled delivery.

From the Solution Processing of Hydrophilic Molecules to Polymer-Phthalocyanine Hybrid Materials for Ammonia Sensing in High Humidity Atmospheres

PubMed Central

Gaudillat, Pierre; Jurin, Florian; Lakard, Boris; Buron, Cédric; Suisse, Jean-Moïse; Bouvet, Marcel

2014-01-01

We have prepared different hybrid polymer-phthalocyanine materials by solution processing, starting from two sulfonated phthalocyanines, s-CoPc and CuTsPc, and polyvinylpyrrolidone (PVP), polyethylene glycol (PEG), poly(acrylic acid-co-acrylamide) (PAA-AM), poly(diallyldimethylammonium chloride) (PDDA) and polyaniline (PANI) as polymers. We also studied the response to ammonia (NH3) of resistors prepared from these sensing materials. The solvent casted films, prepared from s-CoPc and PVP, PEG and PAA-AM, were highly insulating and very sensitive to the relative humidity (RH) variation. The incorporation of s-CoPc in PDDA by means of layer-by-layer (LBL) technique allowed to stabilize the film, but was too insulating to be interesting. We also prepared PANI-CuTsPc hybrid films by LBL technique. It allowed a regular deposition as evidenced by the linear increase of the absorbance at 688 nm as a function of the number of bilayers. The sensitivity to ammonia (NH3) of PANi-CuTsPc resistors was very high compared to that of individual materials, giving up to 80% of current decrease when exposed to 30 ppm NH3. Contrarily to what happens with neutral polymers, in PANI, CuTsPc was stabilized by strong electrostatic interactions, leading to a stable response to NH3, whatever the relative humidity in the range 10%–70%. Thus, the synergy of PANI with ionic macrocycles used as counteranions combined with their simple aqueous solution processing opens the way to the development of new gas sensors capable of operating in real world conditions. PMID:25061841

Tobacco BY-2 cell-free lysate: an alternative and highly-productive plant-based in vitro translation system.

PubMed

Buntru, Matthias; Vogel, Simon; Spiegel, Holger; Schillberg, Stefan

2014-05-03

Cell-free protein synthesis is a rapid and efficient method for the production of recombinant proteins. Usage of prokaryotic cell-free extracts often leads to non-functional proteins. Eukaryotic counterparts such as wheat germ extract (WGE) and rabbit reticulocyte lysate (RLL) may improve solubility and promote the correct folding of eukaryotic multi-domain proteins that are difficult to express in bacteria. However, the preparation of WGEs is complex and time-consuming, whereas RLLs suffer from low yields. Here we report the development of a novel cell-free system based on tobacco Bright Yellow 2 (BY-2) cells harvested in the exponential growth phase. The highly-productive BY-2 lysate (BYL) can be prepared quickly within 4-5 h, compared to 4-5 d for WGE. The efficiency of the BYL was tested using three model proteins: enhanced yellow fluorescent protein (eYFP) and two versions of luciferase. The added mRNA was optimized by testing different 5' and 3' untranslated regions (UTRs). The protein yield in batch and dialysis reactions using BYL was much higher than that of a commercial Promega WGE preparation, achieving a maximum yield of 80 μg/mL of eYFP and 100 μg/mL of luciferase, compared to only 45 μg/mL of eYFP and 35 μg/mL of luciferase in WGEs. In dialysis reactions, the BYL yielded about 400 μg/mL eYFP, representing up to 50% more of the target protein than the Promega WGE, and equivalent to the amount using 5Prime WGE system. Due to the high yield and the short preparation time the BYL represents a remarkable improvement over current eukaryotic cell-free systems.

A novel assay method for the trace determination of Th and U in copper and lead using inductively coupled plasma mass spectrometry

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

LaFerriere, Brian D.; Maiti, Tapas C.; Arnquist, Isaac J.

2015-03-01

This study describes a novel sample preparation and assay method developed in support of the MAJORANA DEMONSTRATOR experiment for the determination of thorium and uranium levels in copper and lead shielding components. Meticulously clean sample preparation methods combined with novel anion exchange separations for analyte pre-concentration and matrix removal were developed. Quantification was performed by inductively coupled plasma mass spectrometry. Detection limits of 0.0084 pg 232Th/g and 0.0106 pg 238U/g were determined for copper, while detection limits of 0.23 pg 232Th/g and 0.46 pg 238U/g were achieved for lead. These methods allow the Majorana Collaboration to accurately assay detector componentsmore » and ensure that the experiment’s stringent radiopurity requirements are met.« less

University Strategic Planning: A Process for Change in a Principal Preparation Program

ERIC Educational Resources Information Center

Guerra, Federico R.; Zamora, Roberto; Hernandez, Rosalinda; Menchaca, Velma

2017-01-01

This study describes a strategic planning process used for developing an educational leadership program that prepares principals for leading 21st century schools. The plan is based on recommendations received from the External reviewers representing Southern Association of Colleges and Schools, the Texas Education Agency, survey responses received…

Giving Feedback: Preparing Students for Peer Review and Self-Evaluation

ERIC Educational Resources Information Center

Philippakos, Zoi A.

2017-01-01

Revision is an important aspect of the writing process but is often challenging for students. Peer review can be helpful, but training is needed for it to work effectively. This article suggests an approach to preparing students for peer review by teaching specific evaluation criteria and leading collaborative practice in reviewing papers written…

Aspen's Global 100: Beyond Grey Pinstripes 2009-2010--Preparing MBAs for Social and Environmental Stewardship

ERIC Educational Resources Information Center

Aspen Institute, 2009

2009-01-01

Beyond Grey Pinstripes is a research survey and alternative ranking of business schools that spotlights innovative full-time MBA programs leading the way in integrating social and environmental stewardship into their curriculum and scholarly research. These schools are preparing today's students--tomorrow's leaders--for future market realities by…

Principal's Preparation Program: Managing the Learning Environment Using ELCC Standards

ERIC Educational Resources Information Center

Tubbs, J. Eric; Heard, Michael S.; Epps, Adrian

2011-01-01

School principals need to be well prepared to manage school facilities assigned to their care. Educational leadership programs can make best use of the Educational Leadership Constituent Council (ELCC) Standards to develop a course of study to address school facility management issues. Every standard has its facility implications that lead to…

Literature review and desk scan : task 2 of preparing a possible Oregon road map for connected vehicle/cooperative systems deployment scenarios.

DOT National Transportation Integrated Search

2016-04-01

The goal of this project was to lay the groundwork for Oregon to be prepared to lead in the : implementation of a connected vehicle/cooperative systems transportation portfolio, and/or to avoid being caught by : surprise as developments in this area ...

75 FR 58370 - Notice of Intent To Prepare a Legislative Environmental Impact Statement for the Proposed...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-24

... DEPARTMENT OF DEFENSE Department of the Navy Notice of Intent To Prepare a Legislative... Withdrawal Lead Agency: Department of the Navy, DoD. Cooperating Agency: Bureau of Land Management... Code of Federal Regulations [CFR] Parts 1500- 1508), the Department of the Navy (DoN) and the United...

Increasing Accountability for Teacher Preparation Programs. Challenge to Lead

ERIC Educational Resources Information Center

Jackson, Jenny, Comp.

2006-01-01

Southern Regional Education Board (SREB) states face new challenges as they adapt to the requirements of the federal No Child Left Behind Act of 2001. This report reviews SREB states' progress in strengthening their accountability systems to ensure that their teacher preparation programs are producing quality teachers. This report identifies what…

Preparing Tomorrow's Leaders: Integrating Leadership Development in Journalism and Mass Communication Education

ERIC Educational Resources Information Center

Bronstein, Carolyn; Fitzpatrick, Kathy R.

2015-01-01

New journalism and mass communication curricula must prepare students to lead the media revolutions of the twenty-first century. Journalism, public relations, and advertising are being transformed by new media platforms and entrepreneurship, and these fields are now defined by rapid, radical change. Yet, the corresponding--and urgent--need to…

Next in Line: Preparing Assistant Principals for the Principalship

ERIC Educational Resources Information Center

Johnson-Taylor, Cindy; Martin, Mary B.

2007-01-01

Grooming an assistant principal to lead a school is a privilege for any principal and enables him or her to leave a larger mark on the field. Although assistant principals are ultimately responsible for their own professional growth, principals must not underestimate their responsibility to help train aspiring principals. Preparing assistant…

Technical Report of: Assessing Teacher Preparation Program Effectiveness--A Pilot Examination of Value Added Approaches

ERIC Educational Resources Information Center

Noell, George H.

2005-01-01

Analyses were conducted replicating pilot work examining the feasibility of using the Louisiana's educational assessment data in concert with the Louisiana Educational Assessment Data System (LEADS) database and other associated databases to assess teacher preparation programs. The degree of matching across years and the degree of matching between…

Making Space for Preservice Teacher Agency through Connected Learning in Preservice Educational Technology Courses

ERIC Educational Resources Information Center

Lohnes Watulak, Sarah

2018-01-01

Preparing future teachers to integrate technology into their teaching in ways that support transformative student learning is a priority for teacher preparation programs in the United States. However, technology instruction often focuses on functional technology skills, leading to ineffective future technology integration. This study examined two…

Preparing Global Leaders: A Theoretical Model for Understanding the Development of Intercultural Competency

ERIC Educational Resources Information Center

Martinez, Cynthia Ann

2012-01-01

As globalization increases, organizations are seeking individuals that have developed intercultural competency (ICC) and are prepared to lead for the 21st century. Although there are competing definitions among scholars as to what characteristics (ability, attitude, awareness, behaviors, knowledge, skills, or values) make up ICC (Ang & Van…

Preparation of High Purity, High Molecular-Weight Chitin from Ionic Liquids for Use as an Adsorbate for the Extraction of Uranium from Seawater

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

Rogers, Robin

Ensuring a domestic supply of uranium is a key issue facing the wider implementation of nuclear power. Uranium is mostly mined in Kazakhstan, Australia, and Canada, and there are few high-grade uranium reserves left worldwide. Therefore, one of the most appealing potential sources of uranium is the vast quantity dissolved in the oceans (estimated to be 4.4 billion tons worldwide). There have been research efforts centered on finding a means to extract uranium from seawater for decades, but so far none have resulted in an economically viable product, due in part to the fact that the materials that have beenmore » successfully demonstrated to date are too costly (in terms of money and energy) to produce on the necessary scale. Ionic Liquids (salts which melt below 100{degrees}C) can completely dissolve raw crustacean shells, leading to recovery of a high purity, high molecular weight chitin powder and to fibers and films which can be spun directly from the extract solution suggesting that continuous processing might be feasible. The work proposed here will utilize the unprecedented control this makes possible over the chitin fiber a) to prepare electrospun nanofibers of very high surface area and in specific architectures, b) to modify the fiber surfaces chemically with selective extractant capacity, and c) to demonstrate their utility in the direct extraction and recovery of uranium from seawater. This approach will 1) provide direct extraction of chitin from shellfish waste thus saving energy over the current industrial process for obtaining chitin; 2) allow continuous processing of nanofibers for very high surface area fibers in an economical operation; 3) provide a unique high molecular weight chitin not available from the current industrial process, leading to stronger, more durable fibers; and 4) allow easy chemical modification of the large surface areas of the fibers for appending uranyl selective functionality providing selectivity and ease of stripping. The resulting sorbent should prove economically feasible, as well as providing an overall net energy gain.« less

Laser patterning of transparent polymers assisted by plasmon excitation.

PubMed

Elashnikov, R; Trelin, A; Otta, J; Fitl, P; Mares, D; Jerabek, V; Svorcik, V; Lyutakov, O

2018-06-13

Plasmon-assisted lithography of thin transparent polymer films, based on polymer mass-redistribution under plasmon excitation, is presented. The plasmon-supported structures were prepared by thermal annealing of thin Ag films sputtered on glass or glass/graphene substrates. Thin films of polymethylmethacrylate, polystyrene and polylactic acid were then spin-coated on the created plasmon-supported structures. Subsequent laser beam writing, at the wavelength corresponding to the position of plasmon absorption, leads to mass redistribution and patterning of the thin polymer films. The prepared structures were characterized using UV-Vis spectroscopy and confocal and AFM microscopy. The shape of the prepared structures was found to be strongly dependent on the substrate type. The mechanism leading to polymer patterning was examined and attributed to the plasmon-heating. The proposed method makes it possible to create different patterns in polymer films without the need for wet technological stages, powerful light sources or a change in the polymer optical properties.

Preparing Educators to Partner with Families

ERIC Educational Resources Information Center

Miller, Gloria E.; Lines, Cathy; Sullivan, Erin; Hermanutz, Kirsten

2013-01-01

The present study focuses on current efforts underway in one western US state to prepare educators' for meaningful participation with families. Directors and faculty from 43 accredited Institutions of Higher Education (IHEs) preparing pre-service teachers, administrators, and student support personnel were asked to complete an online survey…

75 FR 72858 - Agency Information Collection Activities; Revision of a Currently-Approved Information Collection...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-26

... Safety Assistance Programs (MCSAP).'' The information required consists of grant application preparation, quarterly reports and electronic data documenting the results of driver/vehicle inspections performed by the... Time per Response: Grant application preparation: 79.5 hours each; quarterly report preparation: 8...

Principal Perceptions of the Effectiveness of University Educational Leadership Preparation and Professional Learning

ERIC Educational Resources Information Center

Johnson, Arvin D.

2016-01-01

Principals and assistant principals currently serving in Florida and Georgia school districts were surveyed about their perceptions of university educational leadership preparation and professional learning. The results revealed that many principals and assistant principals agreed that university educational leadership preparation programs…

Hybrid lead-acid battery with reticulated vitreous carbon as a carrier- and current-collector of negative plate

NASA Astrophysics Data System (ADS)

Czerwiński, A.; Obrębowski, S.; Kotowski, J.; Rogulski, Z.; Skowroński, J.; Bajsert, M.; Przystałowski, M.; Buczkowska-Biniecka, M.; Jankowska, E.; Baraniak, M.; Rotnicki, J.; Kopczyk, M.

Bare reticulated vitreous carbon (RVC) plated electrochemically with thin layer of lead was investigated as a negative plate carrier- and current-collector material for lead-acid batteries. Hybrid flooded single cell lead-acid batteries containing one negative plate based on a new type (RVC or Pb/RVC) of carrier/current-collector and two positive plates based on Pb-Ca grid collectors were assembled and subjected to charge/discharge tests (at 20-h and 1-h discharge rates) and Peukert's dependences determination. The promising results show that application of RVC as carrier- and current-collector in negative plate will significantly increase the specific capacity of lead-acid battery.

Emerging therapeutic potential of graviola and its constituents in cancers.

PubMed

Qazi, Asif Khurshid; Siddiqui, Jawed A; Jahan, Rahat; Chaudhary, Sanjib; Walker, Larry A; Sayed, Zafar; Jones, Dwight T; Batra, Surinder K; Macha, Muzafar A

2018-04-05

Cancer remains a leading cause of death in the USA and around the world. Although the current synthetic inhibitors used in targeted therapies have improved patient prognosis, toxicity and development of resistance to these agents remain a challenge. Plant-derived natural products and their derivatives have historically been used to treat various diseases, including cancer. Several leading chemotherapeutic agents are directly or indirectly based on botanical natural products. Beyond these important drugs, however, a number of crude herbal or botanical preparations have also shown promising utility for cancer and other disorders. One such natural resource is derived from certain plants of the family Annonaceae, which are widely distributed in tropical and subtropical regions. Among the best known of these is Annona muricata, also known as soursop, graviola or guanabana. Extracts from the fruit, bark, seeds, roots and leaves of graviola, along with several other Annonaceous species, have been extensively investigated for anticancer, anti-inflammatory and antioxidant properties. Phytochemical studies have identified the acetogenins, a class of bioactive polyketide-derived constituents, from the extracts of Annonaceous species, and dozens of these compounds are present in different parts of graviola. This review summarizes current literature on the therapeutic potential and molecular mechanism of these constituents from A.muricata against cancer and many non-malignant diseases. Based on available data, there is good evidence that these long-used plants could have both chemopreventive and therapeutic potential. Appropriate attention to safety studies will be important to assess their effectiveness on various diseases caused or promoted by inflammation.

The impact of system of care support in adherence to wraparound principles in Child and Family Teams in child welfare in North Carolina.

PubMed

Snyder, Elizabeth H; Lawrence, C Nicole; Dodge, Kenneth A

2012-04-01

North Carolina is one of a growing number of states to implement family meeting models in child welfare as a way to engage families, while simultaneously addressing complex familial needs and child safety issues. However, much is still unknown regarding how family meetings actually operate in child welfare, underscoring a clear need for further evaluation of this process. Utilizing direct observational data of Child and Family Team (CFT) meetings, collected as part of two separate evaluations of the North Carolina Division of Social Service's Multiple Response System (MRS) and System of Care (SOC) initiatives, the purpose of the current study was to examine whether the support provided by SOC improved fidelity to the CFT model in child welfare. The observations were conducted using the Team Observation Measure consisting of 78 indicators that measure adherence to ten domains associated with high quality family team meetings (e.g., collaborative, individualized, natural supports, outcomes based, strengths-based). Findings indicate that receiving SOC support in child welfare leads to a more collaborative and individualized decision-making process with families. Meeting facilitators in SOC counties were better prepared for CFTs, and had greater ability to lead a more robust and creative brainstorming process to develop a family-driven case plan. The current study also provides a much needed description of the CFT meeting process within child welfare using a direct observational measure.

The Physics of Shot Towers

ERIC Educational Resources Information Center

Lipscombe, Trevor C.; Mungan, Carl E.

2012-01-01

In the late 18th and throughout the 19th century, lead shot for muskets was prepared by use of a shot tower. Molten lead was poured from the top of a tower and, during its fall, the drops became spherical under the action of surface tension. In this article, we ask and answer the question: "How does the size of the lead shot depend on the height…

Highly Efficient and Uniform 1 cm2 Perovskite Solar Cells with an Electrochemically Deposited NiOx Hole-Extraction Layer.

PubMed

Park, Ik Jae; Kang, Gyeongho; Park, Min Ah; Kim, Ju Seong; Seo, Se Won; Kim, Dong Hoe; Zhu, Kai; Park, Taiho; Kim, Jin Young

2017-06-22

Given that the highest certified conversion efficiency of the organic-inorganic perovskite solar cell (PSC) already exceeds 22 %, which is even higher than that of the polycrystalline silicon solar cell, the significance of new scalable processes that can be utilized for preparing large-area devices and their commercialization is rapidly increasing. From this perspective, the electrodeposition method is one of the most suitable processes for preparing large-area devices because it is an already commercialized process with proven controllability and scalability. Here, a highly uniform NiO x layer prepared by electrochemical deposition is reported as an efficient hole-extraction layer of a p-i-n-type planar PSC with a large active area of >1 cm 2 . It is demonstrated that the increased surface roughness of the NiO x layer, achieved by controlling the deposition current density, facilitates the hole extraction at the interface between perovskite and NiO x , and thus increases the fill factor and the conversion efficiency. The electrochemically deposited NiO x layer also exhibits extremely uniform thickness and morphology, leading to highly efficient and uniform large-area PSCs. As a result, the p-i-n-type planar PSC with an area of 1.084 cm 2 exhibits a stable conversion efficiency of 17.0 % (19.2 % for 0.1 cm 2 ) without showing hysteresis effects. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Highly Efficient and Uniform 1 cm 2 Perovskite Solar Cells with an Electrochemically Deposited NiO x Hole-Extraction Layer

DOE PAGES

Park, Ik Jae; Kang, Gyeongho; Park, Min Ah; ...

2017-05-10

Here, given that the highest certified conversion efficiency of the organic-inorganic perovskite solar cell (PSC) already exceeds 22%, which is even higher than that of the polycrystalline silicon solar cell, the significance of new scalable processes that can be utilized for preparing large-area devices and their commercialization is rapidly increasing. From this perspective, the electrodeposition method is one of the most suitable processes for preparing large-area devices because it is an already commercialized process with proven controllability and scalability. Here, a highly uniform NiO x layer prepared by electrochemical deposition is reported as an efficient hole-extraction layer of a p-i-n-typemore » planar PSC with a large active area of >1 cm 2. It is demonstrated that the increased surface roughness of the NiO x layer, achieved by controlling the deposition current density, facilitates the hole extraction at the interface between perovskite and NiO x, and thus increases the fill factor and the conversion efficiency. The electrochemically deposited NiO x layer also exhibits extremely uniform thickness and morphology, leading to highly efficient and uniform large-area PSCs. As a result, the p-i-n-type planar PSC with an area of 1.084 cm 2 exhibits a stable conversion efficiency of 17.0% (19.2% for 0.1 cm 2) without showing hysteresis effects.« less

Partners in projects: preparing for public involvement in health and social care research.

PubMed

Parkes, Jacqueline H; Pyer, Michelle; Wray, Paula; Taylor, Jane

2014-09-01

In recent years, several UK and, international funders of health and social care related research have adopted the policy of requiring explicit evidence of the 'public' voice in all aspects of project design. For many academic researchers engaged within research, evaluations or audit projects, this formal requirement to actively engage members of the public will present them with both benefits and challenges to securing knowledgeable, skilled, and confident lay representation onto project teams. This could potentially lead to the exploitation of those individuals who are available, appropriately informed, and adequately prepared for such activities. Currently, much of the preparation of patients or members of the public for research involvement tends to be aligned to specific projects; however, with the call for greater active and meaningful involvement of lay representatives in future national and international funding applications, there is clearly a growing need to 'train' sufficient numbers of confident and competent representatives to meet this growing demand. This paper describes the development of a specifically designed research awareness training programme and underpinning theoretical model, which has been specifically designed to support active and meaningful lay involvement in research, evaluations and audit projects. Developed over a four year period, the course is a culmination of learning extracted from a series of four completed research projects, which have incorporated an element of public and patient involvement (PPI) training in their overall design. Crown Copyright © 2014. Published by Elsevier Ireland Ltd. All rights reserved.

Iron oxide nanozyme catalyzed synthesis of fluorescent polydopamine for light-up Zn2+ detection

NASA Astrophysics Data System (ADS)

Liu, Biwu; Han, Xiao; Liu, Juewen

2016-07-01

Fluorescent polydopamine (FPD) is an interesting material with excellent biocompatibility. However, its preparation is currently a lengthy and potentially dangerous process. We herein employ magnetic iron oxide (Fe3O4) nanoparticles as a peroxidase-mimicking nanozyme to produce FPD under mild conditions. Different from previous protocols using multiple steps with up to 6% (~2 M) H2O2, this preparation takes place in a single step with just 5 mM H2O2 at room temperature. The oxidized product shows excitation-wavelength-dependent emission peaks, similar to previous reports. The reaction kinetics, pH, temperature, and ionic strength are individually optimized. Among a diverse range of other nanomaterials tested, including Fe2O3, CeO2, CoO, Co3O4, NiO, TiO2, gold nanoparticles, and graphene oxide, Fe2O3 and graphene oxide yielded relatively weak emission, while the rest of the materials failed to produce FPD. The Fe3O4 nanoparticles retained ~90% catalytic activity even after ten cycles of synthesis. Finally, Zn2+ can enhance the fluorescence of FPD under 360 nm excitation but not under 480 nm excitation, leading to a sensitive light-up sensor with a detection limit of 60 nM Zn2+. Therefore, this work has demonstrated not only a novel use of nanozymes, but also an interesting application of FPD.Fluorescent polydopamine (FPD) is an interesting material with excellent biocompatibility. However, its preparation is currently a lengthy and potentially dangerous process. We herein employ magnetic iron oxide (Fe3O4) nanoparticles as a peroxidase-mimicking nanozyme to produce FPD under mild conditions. Different from previous protocols using multiple steps with up to 6% (~2 M) H2O2, this preparation takes place in a single step with just 5 mM H2O2 at room temperature. The oxidized product shows excitation-wavelength-dependent emission peaks, similar to previous reports. The reaction kinetics, pH, temperature, and ionic strength are individually optimized. Among a diverse range of other nanomaterials tested, including Fe2O3, CeO2, CoO, Co3O4, NiO, TiO2, gold nanoparticles, and graphene oxide, Fe2O3 and graphene oxide yielded relatively weak emission, while the rest of the materials failed to produce FPD. The Fe3O4 nanoparticles retained ~90% catalytic activity even after ten cycles of synthesis. Finally, Zn2+ can enhance the fluorescence of FPD under 360 nm excitation but not under 480 nm excitation, leading to a sensitive light-up sensor with a detection limit of 60 nM Zn2+. Therefore, this work has demonstrated not only a novel use of nanozymes, but also an interesting application of FPD. Electronic supplementary information (ESI) available: Methods, TEM, ζ-potential, and original fluorescence spectra. See DOI: 10.1039/c6nr02584f

Quality specifications in postgraduate medical e-learning: an integrative literature review leading to a postgraduate medical e-learning model.

PubMed

De Leeuw, R A; Westerman, Michiel; Nelson, E; Ket, J C F; Scheele, F

2016-07-08

E-learning is driving major shifts in medical education. Prioritizing learning theories and quality models improves the success of e-learning programs. Although many e-learning quality standards are available, few are focused on postgraduate medical education. We conducted an integrative review of the current postgraduate medical e-learning literature to identify quality specifications. The literature was thematically organized into a working model. Unique quality specifications (n = 72) were consolidated and re-organized into a six-domain model that we called the Postgraduate Medical E-learning Model (Postgraduate ME Model). This model was partially based on the ISO-19796 standard, and drew on cognitive load multimedia principles. The domains of the model are preparation, software design and system specifications, communication, content, assessment, and maintenance. This review clarified the current state of postgraduate medical e-learning standards and specifications. It also synthesized these specifications into a single working model. To validate our findings, the next-steps include testing the Postgraduate ME Model in controlled e-learning settings.

Shaping NASA's Earth Science Enterprise Workforce Development Initiative to Address Industry Needs

NASA Technical Reports Server (NTRS)

Rosage, David; Meeson, Blanche W. (Technical Monitor)

2001-01-01

It has been well recognized that the commercial remote sensing industry will expand in new directions, resulting in new applications, thus requiring a larger, more skilled workforce to fill the new positions. In preparation for this change, NASA has initiated a Remote Sensing Professional Development Program to address the workforce needs of this emerging industry by partnering with the private sector, academia, relevant professional societies, and other R&D organizations. Workforce needs will in part include understanding current industry concerns, personnel competencies, current and future skills, growth rates, geographical distributions, certifications, and sources of pre-service and in-service personnel. Dave Rosage of the NASA Goddard Space Flight Center and a panel of MAPPS members will lead a discussion to help NASA specifically address private firms' near and long-term personnel needs to be included in NASA's Remote Sensing Professional Development Program. In addition, Dave Rosage will present perspectives on how remote sensing technologies are evolving, new NASA instruments being developed, and what future workforce skills are expected to support these new developments.

Study of Solid-State Diffusion of Bi in Polycrystalline Sn Using Electron Probe Microanalysis

NASA Astrophysics Data System (ADS)

Delhaise, André M.; Perovic, Doug D.

2018-03-01

Current lead-free solders such as SAC305 exhibit degradation in microstructure, properties, and reliability. Current third-generation alloys containing bismuth (Bi) demonstrate preservation of strength after aging; this is accompanied by homogenization of the Bi precipitates in the tin (Sn) matrix, driven via solid-state diffusion. This study quantifies the diffusion of Bi in Sn. Diffusion couples were prepared by mating together polished samples of pure Sn and Bi. Couples were annealed at one of three temperatures, viz. 85°C for 7 days, 100°C for 2 days, or 125°C for 1 day. After cross-sectioning the couples to examine the diffusion microstructure and grain size, elemental analysis was performed using electron probe microanalysis. For this study, it was assumed that the diffusivity of Bi in Sn is concentration dependent, therefore inverse methods were used to solve Fick's non-steady-state diffusion equation. In addition, Darken analysis was used to extract the impurity diffusivity of Bi in Sn at each temperature, allowing estimation of the Arrhenius parameters D 0 and k A.

Extending WS-Agreement with Multi-round Negotiation Capability

NASA Astrophysics Data System (ADS)

Rumpl, Angela; Wäldrich, Oliver; Ziegler, Wolfgang

The WS-Agreement specification of the Open Grid Forum defines a language and a protocol for advertising the capabilities of service providers and creating agreements based on templates, and for monitoring agreement compliance at runtime. While the specification, which currently is in the process of transition from a proposed recommendation of the Open Grid Forum to a full recommendation, has been widely used after the initial publication in May 2007, it became obvious that the missing possibility to negotiate an agreement rather than just accepting an offer is limiting or inhibiting the use of WS-Agreement for a number of use-cases. Therefore, the Grid Resource Allocation Agreement Working Group of the Open Grid Forum started in 2008 to prepare an extension of WS-Agreement that adds negotiation capabilities without changing the current specification in a way, which leads to an incompatible new version of WS-Agreement. In this paper we present the results of this process with an updated version of the specification in mind and the first implementation in the European project SmartLM.

Lead-free/rare earth-free Green-light-emitting crystal based on organic-inorganic hybrid [(C10H16N)2][MnBr4] with high emissive quantum yields and large crystal size

NASA Astrophysics Data System (ADS)

Cai, Xing-Wei; Zhao, Yu-Yuan; Li, Hong; Huang, Cui-Ping; Zhou, Zhen

2018-06-01

With the flourishing development of emitting materials, tremendous technological progress has been accomplished. However, they still face great challenges in convenient economical environmental-friendly large-scale commercial production. Herein we designed this organic-inorganic hybrid lead-free compound, an emerging class of high-efficiency emitting materials, [(C10H16N)2][MnBr4] (1), which emits intense greenish photoluminescence with a high emissive quantum yields of 72.26%, was prepared through the convenient economical solution method. What's more, compared with rare earth fluorescent materials (especially green-emitting Tb), Mn material is rich in natural resources and low commercial cost, which would possess an increasingly predominant advantage in the preparation of luminescent materials. Additionally, the exceptional thermal stability as well as the low-cost/convenient preparation process makes crystal 1 with the large size of more than 1 cm to be an ideal technologically important green-emitting material and it would open up a new route towards the commercialization process of lead-free/rare earth-free hybrid emitting materials in display and sensing.

Probes for investigating the effect of magnetic field, field orientation, temperature and strain on the critical current density of anisotropic high-temperature superconducting tapes in a split-pair 15 T horizontal magnet.

PubMed

Sunwong, P; Higgins, J S; Hampshire, D P

2014-06-01

We present the designs of probes for making critical current density (Jc) measurements on anisotropic high-temperature superconducting tapes as a function of field, field orientation, temperature and strain in our 40 mm bore, split-pair 15 T horizontal magnet. Emphasis is placed on the design of three components: the vapour-cooled current leads, the variable temperature enclosure, and the springboard-shaped bending beam sample holder. The vapour-cooled brass critical-current leads used superconducting tapes and in operation ran hot with a duty cycle (D) of ~0.2. This work provides formulae for optimising cryogenic consumption and calculating cryogenic boil-off, associated with current leads used to make J(c) measurements, made by uniformly ramping the current up to a maximum current (I(max)) and then reducing the current very quickly to zero. They include consideration of the effects of duty cycle, static helium boil-off from the magnet and Dewar (b'), and the maximum safe temperature for the critical-current leads (T(max)). Our optimized critical-current leads have a boil-off that is about 30% less than leads optimized for magnet operation at the same maximum current. Numerical calculations show that the optimum cross-sectional area (A) for each current lead can be parameterized by LI(max)/A = [1.46D(-0.18)L(0.4)(T(max) - 300)(0.25D(-0.09)) + 750(b'/I(max))D(10(-3)I(max)-2.87b') × 10⁶ A m⁻¹ where L is the current lead's length and the current lead is operated in liquid helium. An optimum A of 132 mm(2) is obtained when I(max) = 1000 A, T(max) = 400 K, D = 0.2, b' = 0.3 l h(-1) and L = 1.0 m. The optimized helium consumption was found to be 0.7 l h(-1). When the static boil-off is small, optimized leads have a boil-off that can be roughly parameterized by: b/I(max)  ≈ (1.35 × 10(-3))D(0.41) l h(‑1) A(-1). A split-current-lead design is employed to minimize the rotation of the probes during the high current measurements in our high-field horizontal magnet. The variable-temperature system is based on the use of an inverted insulating cup that operates above 4.2 K in liquid helium and above 77.4 K in liquid nitrogen, with a stability of ±80 mK to ±150 mK. Uniaxial strains of -1.4% to 1.0% can be applied to the sample, with a total uncertainty of better than ±0.02%, using a modified bending beam apparatus which includes a copper beryllium springboard-shaped sample holder.

Rabbit ventricular myocardium undergoing simulated ischemia and reperfusion in a double compartment tissue bath: a model to investigate both antiarrhythmic and arrhythmogenic likelihood.

PubMed

Alexandre, Joachim; Schiariti, Michele; Rouet, René; Puddu, Paolo Emilio

2013-01-01

An ischemia/reperfusion-simulating model in rabbit tissue should be right oriented and clinically relevant to provide a non expensive approach for manipulations of currents involved in the repolarization process. Standard right ventricular guinea-pig (N=18) and newly investigated rabbit (N=12) myocardial strips were placed in a special perfusion chamber allowing partition into two segments independently superfused with oxygenated Tyrode's solution or a modified Tyrode's solution mimicking ischemia by: 1) increased extracellular potassium concentration (12 mmol/L), 2) decreased HCO3 (-) concentration (9 mmol/L), leading to a decrease in pH (6.90 ± 0.05), 3) decreased pO2 by replacement of 95% O2 and 5% CO2 by 95% N2 and 5% CO2 gas mixture, and 4) complete withdrawal of glucose. There were significant differences in rabbit as compared to guinea-pig preparations in baseline (p<0.02) and post-ischemic-like (p<0.01) APA and RMP with lower values in the formers, and lower post-ischemic Vmax in rabbit preparations (25±15 versus 97±83 V/s, p<0.01) but neither baseline nor post-ischemic-like or absolute changes in APD50, APD90 were different. In ischemia- and reperfusion-like phases, there were high proportions of single spontaneous repetitive responses, both in guinea-pig (respectively 50 and 89%) and rabbit preparations (respectively 67 and 92%). Guinea-pig preparations showed higher incidence of severe spontaneous repetitive responses (61 versus 17%, p<0.02). This rabbit model is proposed to investigate both anti- and pro-arrhythmic effects of drugs acting at various levels electrophysiologically, which may be obtained with great power and relatively few (around 10 per group) preparations. This model should now be tested pharmacologically.

The pathways of high school science teachers and policy efforts to alter the pipeline

NASA Astrophysics Data System (ADS)

Sass, Tim

2012-03-01

There is currently much interest in improving the quality of science education in K-12 schools and encouraging more students, particularly minorities and women, to pursue careers in STEM fields. Two interrelated issues are at the forefront: the quality of science teachers and the supply of science teachers. Education research in general finds that the single most important school-based factor affecting student achievement is teacher quality. While there is little evidence that teacher credentials matter for student achievement in the lower grades, there is at least some evidence that content knowledge is an important determinant of teacher quality in middle and secondary schools. However, little is known about the pre-service preparation of high school science teachers and how the training of science teachers affects their performance in the classroom. While there are many efforts underway to increase the supply of science teachers, little is known about the supply of science teachers from different pathways and the factors that lead science teachers to leave the profession. In this presentation I discuss recent work on the supply of teachers from alternative pathways, focusing on high school science teachers. I also summarize the literature on teacher quality and attrition, emphasizing the current state of knowledge on secondary school teachers. Finally, I present current policy initiatives and discuss the likelihood of their success given current research findings.

In Situ Monitoring of Pb2+ Leaching from the Galvanic Joint Surface in a Prepared Chlorinated Drinking Water.

PubMed

Ma, Xiangmeng; Armas, Stephanie M; Soliman, Mikhael; Lytle, Darren A; Chumbimuni-Torres, Karin; Tetard, Laurene; Lee, Woo Hyoung

2018-02-20

A novel method using a micro-ion-selective electrode (micro-ISE) technique was developed for in situ lead monitoring at the water-metal interface of a brass-leaded solder galvanic joint in a prepared chlorinated drinking water environment. The developed lead micro-ISE (100 μm tip diameter) showed excellent performance toward soluble lead (Pb 2+ ) with sensitivity of 22.2 ± 0.5 mV decade -1 and limit of detection (LOD) of 1.22 × 10 -6 M (0.25 mg L -1 ). The response time was less than 10 s with a working pH range of 2.0-7.0. Using the lead micro-ISE, lead concentration microprofiles were measured from the bulk to the metal surface (within 50 μm) over time. Combined with two-dimensional (2D) pH mapping, this work clearly demonstrated that Pb 2+ ions build-up across the lead anode surface was substantial, nonuniform, and dependent on local surface pH. A large pH gradient (ΔpH = 6.0) developed across the brass and leaded-tin solder joint coupon. Local pH decreases were observed above the leaded solder to a pH as low as 4.0, indicating it was anodic relative to the brass. The low pH above the leaded solder supported elevated lead levels where even small local pH differences of 0.6 units (ΔpH = 0.6) resulted in about four times higher surface lead concentrations (42.9 vs 11.6 mg L -1 ) and 5 times higher fluxes (18.5 × 10 -6 vs 3.5 × 10 -6 mg cm -2 s -1 ). Continuous surface lead leaching monitoring was also conducted for 16 h.

Facile synthesis of a platinum-lead oxide nanocomposite catalyst with high activity and durability for ethanol electrooxidation.

PubMed

Yang, Wei-Hua; Wang, Hong-Hui; Chen, De-Hao; Zhou, Zhi-You; Sun, Shi-Gang

2012-12-21

Aimed at searching for highly active and stable nano-scale Pt-based catalysts that can improve significantly the energy conversion efficiency of direct ethanol fuel cells (DEFCs), a novel Pt-PbO(x) nanocomposite (Pt-PbO(x) NC) catalyst with a mean size of 3.23 nm was synthesized through a simple wet chemistry method without using a surfactant, organometallic precursors and high temperature. Electrocatalytic tests demonstrated that the as-prepared Pt-PbO(x) NC catalyst possesses a much higher catalytic activity and a longer durability than Pt nanoparticles (nm-Pt) and commercial Pt black catalysts for ethanol electrooxidation. For instance, Pt-PbO(x) NC showed an onset potential that was 30 mV and 44 mV less positive, together with a peak current density 1.7 and 2.6 times higher than those observed for nm-Pt and Pt black catalysts in the cyclic voltammogram tests. The ratio of current densities per unit Pt mass on Pt-PbO(x) NC, nm-Pt and Pt black catalysts is 27.3 : 3.4 : 1 for the long-term (2 hours) chronoamperometric experiments measured at -0.4 V (vs. SCE). In situ FTIR spectroscopic studies revealed that the activity of breaking C-C bonds of ethanol of the Pt-PbO(x) NC is as high as 5.17 times that of the nm-Pt, which illustrates a high efficiency of ethanol oxidation to CO(2) on the as-prepared Pt-PbO(x) NC catalyst.

Developing Multicultural Competence for Preparing Student Affairs Professionals through a Study Away Program

ERIC Educational Resources Information Center

Mitchell, Donald, Jr.; Westbrook, Dmitri C.

2016-01-01

Higher education in the United States is becoming more racially, ethnically, and culturally diverse. Given this increasing diversity, developing multicultural competence for current and preparing student affairs professionals (PSAPs) must become more intentional and clearly articulated within graduate preparation programs and further supported by…

Enabling Substantive Reform in the Preparation of School Leaders.

ERIC Educational Resources Information Center

Young, Michelle D.; Petersen, George J.

2002-01-01

Explores some of the challenges facing educational leadership from the position of university educational-leadership preparation programs. Examines the current and future context of leadership preparation through the metaphor of the sports league, in which each franchise is not independent, but interdependent. (Contains 1 figure and 55…

Preparation and Professional Development of Teacher Educators in Tanzania: Current Practices and Prospects

ERIC Educational Resources Information Center

Namamba, Adam; Rao, Congman

2017-01-01

Teacher educators play a key role in teacher education and education in general. Worldwide, little is known about preparation and professional development of teacher educators. This paper critically examined teacher educators' preparation and professional development in the context of educational reforms and mushrooming of teacher education…

Preparative isolation and purification of astaxanthin from the microalga Chlorococcum sp. by high-speed counter-current chromatography.

PubMed

Li, H B; Chen, F

2001-08-03

High-speed counter-current chromatography was applied to the isolation and purification of astaxanthin from microalgae. The crude astaxanthin was obtained by extraction with organic solvents after the astaxanthin esters were saponified. Preparative high-speed counter-current chromatography with a two-phase solvent system composed of n-hexane-ethyl acetate-ethanol-water (5:5:6.5:3, v/v) was successfully performed yielding astaxanthin at 97% purity from 250 mg of the crude extract in a one-step separation.

Preparation in and Use of the Nemeth Braille Code for Mathematics by Teachers of Students with Visual Impairments

ERIC Educational Resources Information Center

Rosenblum, L. Penny; Amato, Sheila

2004-01-01

This study examined the preparation in and use of the Nemeth braille code by 135 teachers of students with visual impairments. Almost all the teachers had taken at least one course in the Nemeth code as part of their university preparation. In their current jobs, they prepared a variety of materials, primarily basic operations, word problems,…

Conversion and Retrievability of Hard Copy and Digital Documents on Optical Disks

DTIC Science & Technology

1992-03-01

53 B. CURRENT THESIS PREPARATION TOOLS . ....... 54 1. Thesis Preparation using G-Thesis ..... 55 2. Thesis Preparation using Framemaker ...School mainframe. • Computer Science department students can use a software package called Framemaker , available on Sun work stations in their...by most thesis typists and students. For this reason, the discussion of thesis preparation tools will be limited to; G-thesis, Framemaker and

Bias current dependence of resistivity in Co0.4Fe0.4B0.2 ultrathin film prepared by RF magnetron sputtering

NASA Astrophysics Data System (ADS)

Mandal, Snehal; Mazumdar, Dipak; Das, I.

2018-04-01

Ultrathin film of Co0.4Fe0.4B0.2 was prepared on p-type Si (100) substrate by RF magnetron sputtering. X-Ray Reflectivity and Atomic Force Microscopy measurements were performed to estimate the thickness and surface roughness of the film. Electrical transport measurements were performed by four-probe method in a current-in-plane (CIP) geometry. Presence of non-linearity in the current-voltage (I-V) characteristics was observed at higher current range. The electrical resistivity was found to change by several orders of magnitude (105) by changing the bias current from nano-ampere (nA) to milli-ampere (mA) range. This bias current dependence of the resistivity has been explained by different transport mechanisms.

Evolution of mechanical properties of ultrafine grained 1050 alloy annealing with electric current

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

Cao, Yiheng; He, Lizi, E-mail: helizi@epm.neu.edu.cn; Zhang, Lin

2016-03-15

The tensile properties and microstructures of 1050 aluminum alloy prepared by equal channel angular pressing at cryogenic temperature (cryoECAP) after electric current annealing at 90–210 °C for 3 h were investigated by tensile test, electron back scattering diffraction (EBSD) and transmission electron microscopy (TEM). An unexpected annealing-induced strengthening phenomenon occurs at 90–210 °C, due to a significant decrease in the density of mobile dislocations after annealing, and thus a higher yield stress is required to nucleate alternative dislocation sources during tensile test. The electric current can enhance the motion of dislocations, lead to a lower dislocation density at 90–150 °C,more » and thus shift the peak annealing temperature from 150 °C to 120 °C. Moreover, the electric current can promote the migration of grain boundaries at 150–210 °C, result in a larger grain size at 150 °C and 210 °C, and thus causes a lower yield stress. The sample annealed with electric current has a lower uniform elongation at 90–120 °C, and the deviation in the uniform elongation between samples annealed without and with electric current becomes smaller at 150–210 °C. - Highlights: • An unexpected annealing-induced strengthening phenomenon occurs at 90–210 °C. • The d. c. current can enhance the motion of dislocations at 90–150 °C, and thus shift the peak annealing temperature from 150 °C to 120 °C. • The d. c. current can promote the grain growth at 150–210 °C, and thus cause a lower yield stress. • The DC annealed sample has a lower uniform elongation at 90–120 °C.« less

Synthesis and Microstructure of Highly Oriented PbTiO3 Thin Films Prepared by a Sol-Gel Method

DTIC Science & Technology

1989-06-01

lead acetate with titanium isopropoxide * in 2-methoxyethanol,* in a method similar to that reported by Gurkovitch and Blum." The resulting yellow-gold...orientation by a sol-gel processing method. EXPERIMENTAL Precursor Solution Preparation Stock solutions of complex Pb-Ti alkoxide were prepared by reacting... solution had an equivalent PbTiO 3 concentration of approximately 66 wt%. The alkoxide solutions were handled as moisture-sensitive reagents and, as

Microstructure and properties of ceramic coatings prepared by micro-arc oxidation on 7075 aluminum alloy

NASA Astrophysics Data System (ADS)

Cao, G. P.; Song, R. G.

2018-02-01

Micro-arc oxidation (MAO) ceramic coatings were prepared in silicate-based electrolyte on 7075 aluminum alloy. The effects of current density on microstructure and properties of the MAO coatings were studied by scanning electron microscopy (SEM), stereoscopic microscopy, x-ray diffraction (XRD), electrochemical tests as well as tribological and wear tests. The results showed that the current density plays an important role in affecting the quality of the MAO coatings. XRD results showed that the α-Al2O3 phase first increased then decreased with increasing the current density, which matched well with the micro-hardness test and the wearing test results. On the other hand, the coalescent strength measurements revealed that the coating prepared at the current density of 12 A dm-2 is of the highest adhesion force. The potentiodynamic polarization test proved that the coating obtained under 10 A dm-2 exhibits the best corrosion resistance, which is directly related to the morphology of coating.

Secondary-Level Preservice Teachers Leading Whole-Class Discussions: A Qualitative Case Study

ERIC Educational Resources Information Center

Norland, Gretchen

2017-01-01

Leading a whole-class discussion is a complex and critical skill, and pivotal to learning and achievement. Classroom teachers have been challenged to engage students in meaningful dialogue, and successfully meet educational standards and requirements. Teacher education programs are responsible for preparing future candidates--preservice…

Leading the Charge in Changing Times: 21st Century Learning and Leading

ERIC Educational Resources Information Center

Jones, Amanda Criswell

2016-01-01

Throughout history educational practices have typically been modeled after economic work practices. During the agrarian-age, educational practices modeled agrarian practices. Likewise, in the industrial-age, education became standardized and was modeled after industrial practices to prepare students for work in factories and industrial settings.…

Leadership Excellence through Advancement and Determination Program: A Qualitative Case Study

ERIC Educational Resources Information Center

Perrell, Wendy M.

2012-01-01

Alaska Native leadership development programs are often used to prepare participants and to enhance their leadership potential. The cultural appropriateness of developing Alaska Native leaders through the Western-structured LEAD program was the focal point of this study. Understanding how the LEAD participants adapted to Native and Western…

Big Business Invests in Catholic Education.

ERIC Educational Resources Information Center

Rivera, Richard

2003-01-01

Recognizes the unused potential of inner city kids and describes how The Institute for Leadership, Excellence and Academic Development (I-Lead) program has helped prepare these students for admittance to universities and colleges. I-Lead offers four core courses: (1) test prep class; (2) constitutional law class; (3) writing class; and (4)…

76 FR 26284 - Draft Integrated Science Assessment for Lead (Pb)

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-06

... ENVIRONMENTAL PROTECTION AGENCY [FRL-9302-5; Docket ID No. EPA-HQ-ORD-2011-0051] Draft Integrated... the availability of a document titled, ``First External Review Draft Integrated Science Assessment for Lead'' (EPA/600/R-10/075A). This draft document was prepared by the National Center for Environmental...

Practice Characteristics that Lead to 21st Century Learning Outcomes.

ERIC Educational Resources Information Center

Law, Nancy; Lee, Y.; Chow, A.

2002-01-01

Describes a study in Hong Kong elementary and secondary schools that investigated whether innovative teaching practices that used ICT (information and communication technology) would lead to learning outcomes needed for today's knowledge society. Suggests that affective and socio-cognitive learning outcomes are more important as preparation for…

The Leadership Assignment: Creating Change.

ERIC Educational Resources Information Center

Calabrese, Raymond L.

This book provides change-motivated leaders with an understanding of the change process and the tools to drive change. Eight change principles guide change agents in creating and sustaining change: prepare to lead change; knowledge is power; create empowering mental models; overcome resistance to change; lead change; accelerate the change process;…

Current noise generated by spin imbalance in presence of spin relaxation

NASA Astrophysics Data System (ADS)

Khrapai, V. S.; Nagaev, K. E.

2017-01-01

We calculate current (shot) noise in a metallic diffusive conductor generated by spin imbalance in the absence of a net electric current. This situation is modeled in an idealized three-terminal setup with two biased ferromagnetic leads (F-leads) and one normal lead (N-lead). Parallel magnetization of the F-leads gives rise to spin-imbalance and finite shot noise at the N-lead. Finite spin relaxation results in an increase in the shot noise, which depends on the ratio of the length of the conductor ( L) and the spin relaxation length ( l s). For L >> l s the shot noise increases by a factor of two and coincides with the case of the antiparallel magnetization of the F-leads.

The Principalship: Preparation Programs and the Self-Efficacy of Principals

ERIC Educational Resources Information Center

Hughes, Lesley L.

2010-01-01

In today's society, principals are asked to lead in a new world marked by unprecedented responsibilities. The principal's knowledge and mindset play a critical role in the success of students. Principal shortages and turnover rates are at an all-time high. Faced with this knowledge, it is imperative that principals feel prepared for the roles they…

Preparing to Lead: A Leadership Philosophy Exercise for Business Students

ERIC Educational Resources Information Center

Tyran, Kristi Lewis

2017-01-01

This article introduces a leadership philosophy exercise where students reflect on their values and prepare a statement of what they intend to do as a leader in their careers. This exercise has the potential to add value to leadership classes or seminars where personal leadership is the focus. By using the leadership philosophy exercise, I argue…

A standardized method for preparation of potatoes and analysis of their resistant starch content: Variation by cooking method and service temperature

USDA-ARS?s Scientific Manuscript database

Consumption of resistant starch (RS) may lead to reduced glycemia, improved satiety, and beneficial changes in gut microbiota due to its unique digestive and absorptive properties. We developed a standardized protocol for preparation of potatoes in order to assess their RS content and modified a com...

Lessons Learned from Implementing an Intercultural Communication Training Program for Pre-Departure Expatriates

ERIC Educational Resources Information Center

Velten, Justin C.

2015-01-01

Expatriate preparation is an ever growing area of interest in a globalized economy sharing a globalized workforce. For decades, scholars have sought methods for best preparing expatriates for host culture experiences. Research has revealed an array of factors leading to intercultural readiness success which has led to the creation of various…

Preparing School Leaders to Serve as Agents for Social Transformation

ERIC Educational Resources Information Center

Brown, Kathleen M.

2010-01-01

The major priorities that should guide leadership education in preparing leaders for their work of leading schools in a democratic society are: (1) Teaching leaders to understand the inequities of society; (2) Teaching leaders to serve as agents for social transformation; and (3) Teaching leaders to help each and every student learn and succeed.…

Inventory of connected vehicle applications as part of preparing a possible Oregon road map for connected vehicle/cooperative systems deployment scenarios : task 3 report.

DOT National Transportation Integrated Search

2016-05-01

The goal of this project was to lay the groundwork for Oregon to be prepared to lead in the : implementation of a connected vehicle/cooperative systems transportation portfolio, and/or to avoid being : caught by surprise as developments in this area ...

The Role of Nursing History in Preparing Nursing for the Future.

ERIC Educational Resources Information Center

Keeling, Arlene W.; Ramos, Mary Carol

1995-01-01

The development of curricula for nursing education has been a concern of nurse scholars since the genesis of the Standard Curriculum in 1917. The challenge is to build on this knowledge using traditional and nontraditional methods. If doctorally prepared nurses are to lead their profession, nursing history cannot be merely an elective. (Author/JOW)

Recruiting & Preparing Diverse Urban Teachers: One Urban-Focused Teacher Education Program Breaks New Ground

ERIC Educational Resources Information Center

Waddell, Jennifer; Ukpokodu, Omiunota N.

2012-01-01

This article explores a university's Urban Teacher Education Program (UTEP) and its success not just in recruiting, preparing, retaining, and graduating its students, but in likewise leading to employment and retention as teachers in urban schools. It focuses on critical aspects of the program, including recruitment of diverse candidates,…

Inspiring Confidence and Professional Growth in Leadership: Student Perspectives on University- District Partnership Master's Academies

ERIC Educational Resources Information Center

Mejía, Pilar; Devin, Samrie; Calvert, Heather

2016-01-01

School leadership matters when discussing teacher effectiveness and student performance, and preparation programs need to graduate principals with the skills necessary to lead schools for tomorrow. The traditional approach to preparing educational leaders is no longer getting the job done. In this article, Meija, Devin and Calvert, students who…

National Athletic Trainers' Association Position Statement: Anabolic-Androgenic Steroids

PubMed Central

Kersey, Robert D.; Elliot, Diane L.; Goldberg, Linn; Kanayama, Gen; Leone, James E.; Pavlovich, Mike; Pope, Harrison G.

2012-01-01

This NATA position statement was developed by the NATA Research & Education Foundation. Objective This manuscript summarizes the best available scholarly evidence related to anabolic-androgenic steroids (AAS) as a reference for health care professionals, including athletic trainers, educators, and interested others. Background Health care professionals associated with sports or exercise should understand and be prepared to educate others about AAS. These synthetic, testosterone-based derivatives are widely abused by athletes and nonathletes to gain athletic performance advantages, develop their physiques, and improve their body image. Although AAS can be ergogenic, their abuse may lead to numerous negative health effects. Recommendations Abusers of AAS often rely on questionable information sources. Sports medicine professionals can therefore serve an important role by providing accurate, reliable information. The recommendations provide health care professionals with a current and accurate synopsis of the AAS-related research. PMID:23068595

Semisolid Metal Processing Techniques for Nondendritic Feedstock Production

PubMed Central

Mohammed, M. N.; Omar, M. Z.; Salleh, M. S.; Alhawari, K. S.; Kapranos, P.

2013-01-01

Semisolid metal (SSM) processing or thixoforming is widely known as a technology that involves the formation of metal alloys between solidus and liquidus temperatures. For the procedure to operate successfully, the microstructure of the starting material must consist of solid near-globular grains surrounded by a liquid matrix and a wide solidus-to-liquidus transition area. Currently, this process is industrially successful, generating a variety of products with high quality parts in various industrial sectors. Throughout the years since its inception, a number of technologies to produce the appropriate globular microstructure have been developed and applied worldwide. The main aim of this paper is to classify the presently available SSM technologies and present a comprehensive review of the potential mechanisms that lead to microstructural alterations during the preparation of feedstock materials for SSM processing. PMID:24194689

Dirac cone and pseudogapped density of states in the topological half-Heusler compound YPtBi

NASA Astrophysics Data System (ADS)

Kronenberg, A.; Braun, J.; Minár, J.; Elmers, H.-J.; Kutnyakhov, D.; Zaporozhchenko, A. V.; Wallauer, R.; Chernov, S.; Medjanik, K.; Schönhense, G.; Kläui, M.; Chadov, S.; Ebert, H.; Jourdan, M.

2016-10-01

Topological insulators (TIs) are exciting materials, which exhibit unprecedented properties, such as helical spin-momentum locking, which leads to large torques for magnetic switching and highly efficient spin current detection. Here we explore the compound YPtBi, an example from the class of half-Heusler materials, for which the typical band inversion of topological insulators was predicted. We prepared this material as thin films by conventional cosputtering from elementary targets. By in situ time-of-flight momentum microscopy, a Dirac conelike surface state with a Dirac point ≃300 meV below the Fermi energy was observed, in agreement with electronic structure-photoemission calculations. Only little additional spectral weight due to other states was observed at EF, which corroborates the identification of the topologically protected surface state and is highly relevant for spintronics applications.

Durable electrooptic devices comprising ionic liquids

DOEpatents

Burrell, Anthony K [Los Alamos, NM; Agrawal, Anoop [Tucson, AZ; Cronin,; John, P [Tucson, AZ; Tonazzi, Juan C. L. [Tucson, AZ; Warner, Benjamin P [Los Alamos, NM; McCleskey, T Mark [Los Alamos, NM

2009-12-15

Electrolyte solutions for electrochromic devices such as rear view mirrors and displays with low leakage currents are prepared using inexpensive, low conductivity conductors. Preferred electrolytes include bifunctional redox dyes and molten salt solvents with enhanced stability toward ultraviolet radiation. The solvents include lithium or quaternary ammonium cations, and perfluorinated sulfonylimide anions selected from trifluoromethylsulfonate (CF.sub.3SO.sub.3.sup.-), bis(trifluoromethylsulfonyl)imide ((CF.sub.3SO.sub.2).sub.2N.sup.-), bis(perfluoroethylsulfonyl)imide ((CF.sub.3CF.sub.2SO.sub.2).sub.2N.sup.-) and tris(trifluoromethylsulfonyl)methide ((CF.sub.3SO.sub.2).sub.3C.sup.-). Electroluminescent, electrochromic and photoelectrochromic devices with nanostructured electrodes include ionic liquids with bifunctional redox dyes. Some of the electrolyte solutions color to red when devices employing the solutions are powered, leading to red or neutral electrooptic devices.

Preparing the “Soil”: The Premetastatic Niche

PubMed Central

Kaplan, Rosandra N.; Rafii, Shahin; Lyden, David

2010-01-01

Current focus on cancer metastasis has centered on the intrinsic factors regulating the cell autonomous homing of the tumor cells to the metastatic site. Specific up-regulation of fibronectin and clustering of bone marrow–derived cellular infiltrates coexpressing matrix metalloproteinases in distant tissue sites before tumor cell arrival are proving to be indispensable for the initial stages of metastasis. These bone marrow–derived hematopoietic progenitors that express vascular endothelial growth factor receptor 1 mobilize in response to the unique array of growth factors produced by the primary tumor. Their arrival in distant sites represents early changes in the local microenvironment, termed the “premetastatic niche,” which dictate the pattern of metastatic spread. Focus on the early cellular and molecular events in cancer dissemination and selectivity will likely lead to new approaches to detect and prevent metastasis at its earliest inception. PMID:17145848

Neural and Cellular Mechanisms of Fear and Extinction Memory Formation

PubMed Central

Orsini, Caitlin A.; Maren, Stephen

2012-01-01

Over the course of natural history, countless animal species have evolved adaptive behavioral systems to cope with dangerous situations and promote survival. Emotional memories are central to these defense systems because they are rapidly acquired and prepare organisms for future threat. Unfortunately, the persistence and intrusion of memories of fearful experiences are quite common and can lead to pathogenic conditions, such as anxiety and phobias. Over the course of the last thirty years, neuroscientists and psychologists alike have attempted to understand the mechanisms by which the brain encodes and maintains these aversive memories. Of equal interest, though, is the neurobiology of extinction memory formation as this may shape current therapeutic techniques. Here we review the extant literature on the neurobiology of fear and extinction memory formation, with a strong focus on the cellular and molecular mechanisms underlying these processes. PMID:22230704

High-speed growth of TiO2 nanotube arrays with gradient pore diameter and ultrathin tube wall under high-field anodization

NASA Astrophysics Data System (ADS)

Yuan, Xiaoliang; Zheng, Maojun; Ma, Li; Shen, Wenzhong

2010-10-01

Highly ordered TiO2 nanotubular arrays have been prepared by two-step anodization under high field. The high anodizing current densities lead to a high-speed film growth (0.40-1.00 µm min - 1), which is nearly 16 times faster than traditional fabrication of TiO2 at low field. It was found that an annealing process of Ti foil is an effective approach to get a monodisperse and double-pass TiO2 nanotubular layer with a gradient pore diameter and ultrathin tube wall (nearly 10 nm). A higher anodic voltage and longer anodization time are beneficial to the formation of ultrathin tube walls. This approach is simple and cost-effective in fabricating high-quality ordered TiO2 nanotubular arrays for practical applications.

High-speed growth of TiO2 nanotube arrays with gradient pore diameter and ultrathin tube wall under high-field anodization.

PubMed

Yuan, Xiaoliang; Zheng, Maojun; Ma, Li; Shen, Wenzhong

2010-10-08

Highly ordered TiO(2) nanotubular arrays have been prepared by two-step anodization under high field. The high anodizing current densities lead to a high-speed film growth (0.40-1.00 microm min(-1)), which is nearly 16 times faster than traditional fabrication of TiO(2) at low field. It was found that an annealing process of Ti foil is an effective approach to get a monodisperse and double-pass TiO(2) nanotubular layer with a gradient pore diameter and ultrathin tube wall (nearly 10 nm). A higher anodic voltage and longer anodization time are beneficial to the formation of ultrathin tube walls. This approach is simple and cost-effective in fabricating high-quality ordered TiO(2) nanotubular arrays for practical applications.

Crystallization Methods for Preparation of Nanocrystals for Drug Delivery System.

PubMed

Gao, Yuan; Wang, Jingkang; Wang, Yongli; Yin, Qiuxiang; Glennon, Brian; Zhong, Jian; Ouyang, Jinbo; Huang, Xin; Hao, Hongxun

2015-01-01

Low water solubility of drug products causes delivery problems such as low bioavailability. The reduced particle size and increased surface area of nanocrystals lead to the increasing of the dissolution rate. The formulation of drug nanocrystals is a robust approach and has been widely applied to drug delivery system (DDS) due to the significant development of nanoscience and nanotechnology. It can be used to improve drug efficacy, provide targeted delivery and minimize side-effects. Crystallization is the main and efficient unit operation to produce nanocrystals. Both traditional crystallization methods such as reactive crystallization, anti-solvent crystallization and new crystallization methods such as supercritical fluid crystallization, high-gravity controlled precipitation can be used to produce nanocrystals. The current mini-review outlines the main crystallization methods addressed in literature. The advantages and disadvantages of each method were summarized and compared.

Durable Electrooptic Devices Comprising Ionic Liquids

DOEpatents

Burrell, Anthony K.; Agrawal, Anoop; Cronin, John P.; Tonazzi, Juan C. L.; Warner, Benjamin P.; McCleskey, T. Mark

2008-11-11

Electrolyte solutions for electrochromic devices such as rear view mirrors and displays with low leakage currents are prepared using inexpensive, low conductivity conductors. Preferred electrolytes include bifunctional redox dyes and molten salt solvents with enhanced stability toward ultraviolet radiation. The solvents include lithium or quaternary ammonium cations, and perfluorinated sulfonylimide anions selected from trifluoromethylsulfonate (CF.sub.3SO.sub.3.sup.-), bis(trifluoromethylsulfonyl)imide ((CF.sub.3SO.sub.2).sub.2N.sup.-), bis(perfluoroethylsulfonyl)imide ((CF.sub.3CF.sub.2SO.sub.2).sub.2N.sup.-) and tris(trifluoromethylsulfonyl)methide ((CF.sub.3SO.sub.2).sub.3C.sup.-). Electroluminescent, electrochromic and photoelectrochromic devices with nanostructured electrodes include ionic liquids with bifunctional redox dyes. Some of the electrolyte solutions color to red when devices employing the solutions are powered, leading to red or neutral electrooptic devices.

Low resistance splices for HTS devices and applications

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

Lalitha, S. L.

This paper discusses the preparation methodology and performance evaluation of low resistance splices made of the second generation (2G) high-temperature superconductor (HTS). These splices are required in a broad spectrum of HTS devices including a large aperture, high-field solenoid built in the laboratory to demonstrate a superconducting magnetic energy storage (SMES) device. Several pancake coils are assembled in the form of a nested solenoid, and each coil requires a hundred meters or more of 2G (RE)BCO tape. However, commercial availability of this superconductor with a very uniform physical properties is currently limited to shorter piece lengths. This necessitates us havingmore » splices to inter-connect the tape pieces within a pancake coil, between adjacent pancake coils, and to attach HTS current leads to the magnet assembly. As a part of the optimization and qualification of splicing process, a systematic study was undertaken to analyze the electrical performance of splices in two different configurations suitable for this magnet assembly: lap joint and spiral joint. The electrical performance is quantified in terms of the resistance of splices estimated from the current-voltage characteristics. Finally, It has been demonstrated that a careful application of this splicing technique can generate lap joints with resistance less than 1 nΩ at 77 K.« less

Low resistance splices for HTS devices and applications

DOE PAGES

Lalitha, S. L.

2017-06-30

This paper discusses the preparation methodology and performance evaluation of low resistance splices made of the second generation (2G) high-temperature superconductor (HTS). These splices are required in a broad spectrum of HTS devices including a large aperture, high-field solenoid built in the laboratory to demonstrate a superconducting magnetic energy storage (SMES) device. Several pancake coils are assembled in the form of a nested solenoid, and each coil requires a hundred meters or more of 2G (RE)BCO tape. However, commercial availability of this superconductor with a very uniform physical properties is currently limited to shorter piece lengths. This necessitates us havingmore » splices to inter-connect the tape pieces within a pancake coil, between adjacent pancake coils, and to attach HTS current leads to the magnet assembly. As a part of the optimization and qualification of splicing process, a systematic study was undertaken to analyze the electrical performance of splices in two different configurations suitable for this magnet assembly: lap joint and spiral joint. The electrical performance is quantified in terms of the resistance of splices estimated from the current-voltage characteristics. Finally, It has been demonstrated that a careful application of this splicing technique can generate lap joints with resistance less than 1 nΩ at 77 K.« less

Tunneling Characteristics Depending on Schottky Barriers and Diffusion Current in SiOC.

PubMed

Oh, Teresa; Kim, Chy Hyung

2016-02-01

To obtain a diffusion current in SiOC, the aluminum doped zinc oxide films were deposited on SiOC/Si wafer by a RF magnetron sputtering. All the X-ray patterns of the SiOC films showed amorphous phases. The level of binding energy of Si atoms will lead to an additional potential modulation by long range Coulombic and covalent interactions with oxygen ions. The growth of the AZO film was affected by the characteristics of SiOC, resulting in similar trends in XPS spectra and a shift to higher AZO lattice d values than the original AZO d values in XRD analyses. The charges trapped by the defects at the interlayer between AZO and SiOC films induced the decreased mobility of carriers. In the absence of trap charges, AZO grown on SiOC film such as the sample prepared at O2 = 25 or 30 sccm, which has low charge carrier concentration and high mobility, showed high mobility in an ambipolar characteristic of oxide semiconductor due to the tunneling effect and diffusion current. The structural matching of an interface between AZO and amorphous SiOC enhanced the height of Schottky Barrier (SB), and then the mobility was increased by the tunneling effect from band to band through the high SB.

Mechanisms of the palmitoylcarnitine-induced response in vascular endothelial cells.

PubMed

Taki, H; Muraki, K; Imaizumi, Y; Watanabe, M

1999-09-01

The mechanisms of Ca2+ mobilization induced by palmitoylcarnitine (Palcar) in rabbit aortic endothelial cells (ETCs) were examined using electrophysiological techniques. The results obtained were compared with those induced by acetylcholine (ACh). When a rabbit aortic muscle preparation with an intact endothelium was treated with 10 microM Palcar, the ACh-induced relaxation was markedly attenuated, whereas endothelium-independent relaxation caused by sodium nitroprusside was not affected. Under perforated-patch whole-cell-clamp conditions, the application of Palcar over the concentration range 0.3 and 10 microM elicited a slowly activating outward current (IPalcar-out), whereas ACh induced a rapidly activating outward current (IACh). A potassium channel blocker, 4-aminopyridine, significantly inhibited both IPalcar-out and IACh. Removal of external Ca2+ almost abolished IPalcar-out. Under the same conditions, however, IACh remained transient. Addition of cation channel blockers SK&F96365 and La3+ inhibited IPalcar-out more effectively than IACh. Application of staurosporine, an inhibitor of protein kinase C, affected neither IACh nor IPalcar-out. In contrast, treatment of ETCs with pertussis toxin (PTX) reduced IACh and almost abolished IPalcar-out. These findings demonstrate that, in ETCs, Palcar induces Ca2+ influx via the activation of PTX-sensitive GTP-binding protein, leading to the activation of Ca(2+)-dependent K+ current and hyperpolarization of the cell.

Low resistance splices for HTS devices and applications

NASA Astrophysics Data System (ADS)

Lalitha, S. L.

2017-09-01

This paper discusses the preparation methodology and performance evaluation of low resistance splices made of the second generation (2G) high-temperature superconductor (HTS). These splices are required in a broad spectrum of HTS devices including a large aperture, high-field solenoid built in the laboratory to demonstrate a superconducting magnetic energy storage (SMES) device. Several pancake coils are assembled in the form of a nested solenoid, and each coil requires a hundred meters or more of 2G (RE)BCO tape. However, commercial availability of this superconductor with a very uniform physical properties is currently limited to shorter piece lengths. This necessitates us having splices to inter-connect the tape pieces within a pancake coil, between adjacent pancake coils, and to attach HTS current leads to the magnet assembly. As a part of the optimization and qualification of splicing process, a systematic study was undertaken to analyze the electrical performance of splices in two different configurations suitable for this magnet assembly: lap joint and spiral joint. The electrical performance is quantified in terms of the resistance of splices estimated from the current-voltage characteristics. It has been demonstrated that a careful application of this splicing technique can generate lap joints with resistance less than 1 nΩ at 77 K.

Healthier side dishes at restaurants: an analysis of children's perspectives, menu content, and energy impacts.

PubMed

Anzman-Frasca, Stephanie; Dawes, Franciel; Sliwa, Sarah; Dolan, Peter R; Nelson, Miriam E; Washburn, Kyle; Economos, Christina D

2014-07-04

Children consume restaurant-prepared foods at high rates, suggesting that interventions and policies targeting consumption of these foods have the potential to improve diet quality and attenuate excess energy intake. One approach to encouraging healthier dietary intake in restaurants is to offer fruits and vegetables (FV) as side dishes, as opposed to traditional, energy-dense accompaniments like French fries. The aims of the current study were to examine: children's views about healthier side dishes at restaurants; current side dish offerings on children's menus at leading restaurants; and potential energy reductions when substituting FV side dishes in place of French fries. To investigate children's attitudes, a survey was administered to a nationally representative sample of U.S. 8- to 18-year-olds (n = 1178). To examine current side dish offerings, children's menus from leading quick service (QSR; n = 10) and full service restaurant chains (FSR; n = 10) were analyzed. Energy reductions that could result from substituting commonly-offered FV side dishes for French fries were estimated using nutrition information corresponding to the children's menu items. Two-thirds of children reported that they would not feel negatively about receiving FV sides instead of French fries with kids' meals. Liking/taste was the most common reason that children gave to explain their attitudes about FV side dishes. Nearly all restaurants offered at least 1 FV side dish option, but at most restaurants (60% of QSR; 70% of FSR), FV sides were never served by default. Substituting FV side dishes for French fries yielded an average estimated energy reduction of at least 170 calories. Results highlight some healthy trends in the restaurant context, including the majority of children reporting non-negative attitudes about FV side dishes and the consistent availability of FV side dish options at leading QSR and FSR. Yet the minority of restaurants offer these FV sides by default. Promoting creative, appealing FV side dishes can result in healthier, less energy-dense meals for children. Substituting or displacing energy-dense default side dishes with such FV dishes show promise as part of continued, comprehensive efforts to increase the healthfulness of meals consumed by children in restaurant settings.

Chitosan Microspheres in Novel Drug Delivery Systems

PubMed Central

Mitra, Analava; Dey, Baishakhi

2011-01-01

The main aim in the drug therapy of any disease is to attain the desired therapeutic concentration of the drug in plasma or at the site of action and maintain it for the entire duration of treatment. A drug on being used in conventional dosage forms leads to unavoidable fluctuations in the drug concentration leading to under medication or overmedication and increased frequency of dose administration as well as poor patient compliance. To minimize drug degradation and loss, to prevent harmful side effects and to increase drug bioavailability various drug delivery and drug targeting systems are currently under development. Handling the treatment of severe disease conditions has necessitated the development of innovative ideas to modify drug delivery techniques. Drug targeting means delivery of the drug-loaded system to the site of interest. Drug carrier systems include polymers, micelles, microcapsules, liposomes and lipoproteins to name some. Different polymer carriers exert different effects on drug delivery. Synthetic polymers are usually non-biocompatible, non-biodegradable and expensive. Natural polymers such as chitin and chitosan are devoid of such problems. Chitosan comes from the deacetylation of chitin, a natural biopolymer originating from crustacean shells. Chitosan is a biocompatible, biodegradable, and nontoxic natural polymer with excellent film-forming ability. Being of cationic character, chitosan is able to react with polyanions giving rise to polyelectrolyte complexes. Hence chitosan has become a promising natural polymer for the preparation of microspheres/nanospheres and microcapsules. The techniques employed to microencapsulate with chitosan include ionotropic gelation, spray drying, emulsion phase separation, simple and complex coacervation. This review focuses on the preparation, characterization of chitosan microspheres and their role in novel drug delivery systems. PMID:22707817

How to write an article: Preparing a publishable manuscript!

PubMed Central

Shidham, Vinod B.; Pitman, Martha B.; DeMay, Richard M.

2012-01-01

Most of the scientific work presented as abstracts (platforms and posters) at various conferences have the potential to be published as articles in peer-reviewed journals. This DIY (Do It Yourself) article on how to achieve that goal is an extension of the symposium presented at the 36th European Congress of Cytology, Istanbul, Turkey (presentation available on net at http://alturl.com/q6bfp). The criteria for manuscript authorship should be based on the ICMJE (International Committee of Medical Journal Editors) Uniform Requirements for Manuscripts. The next step is to choose the appropriate journal to submit the manuscript and review the ‘Instructions to the authors’ for that journal. Although initially it may appear to be an insurmountable task, diligent organizational discipline with a little patience and perseverance with input from mentors should lead to the preparation of a nearly perfect publishable manuscript even by a novice. Ultimately, the published article is an excellent track record of academic productivity with contribution to the general public good by encouraging the exchange of experience and innovation. It is a highly rewarding conduit to the personal success and growth leading to the collective achievement of continued scientific progress. Recent emergences of journals and publishers offering the platform and opportunity to publish under an open access charter provides the opportunity for authors to protect their copyright from being lost to conventional publishers. Publishing your work on this open platform is the most rewarding mission and is the recommended option in the current modern era. [This open access article can be linked (copy-paste link from HTML version of this article) or reproduced FREELY if original reference details are prominently identifiable]. PMID:22363390

Designing and synthesis of a polymer matrix piezoelectric composite for energy harvesting

NASA Astrophysics Data System (ADS)

Biswal, Asutya Kumar; Das, Satyabati; Roy, Amritendu

2017-02-01

Now a day, a large variety of electronic and network devices require small yet steady power supply for operation. Traditionally, these devices are battery operated and the batteries are periodically charged for continuous operation. Often, the devices are so located that supply of power to recharge the batteries becomes challenging. Electrical energy harvesting by means of principle of piezoelectricity could be a viable solution to the above problem by means of providing a permanent power source. In this regard, piezoelectric lead zirconium titanate (PZT) was found to be a potential material. However, poor mechanical properties (brittleness) of bulk ceramic materials have been a concern for energy harvesting by means of mechanical motion (footsteps). In the present work, Pb(Zr 0.52 Ti 0.48)1-x NbxO 3 at x=0.05 was prepared by conventional solid state synthesis route. XRD and SEM analyses were performed for structural characterization. PZT powders were found to be in single phase with tetragonal symmetry without any trace of a second phase. To render the required mechanical properties (flexibility), in the present work, we designed a polymer matrix ceramic composite without much compromising the piezoelectric properties. We prepared composite thick films of lead zirconium titanate (PZT) ceramic in poly vinylidene fluoride (PVDF) polymer matrix with varied composition of PZT from 10-50 vol %. The study of surface morphology by scanning electron microscope (SEM) shows good degree of dispersion of PZT in PVDF matrix. Ferroelectric characteristics of the composite films were studied by measuring the polarization-electric field hysteresis loops. Generated output voltage and current from the composite films are found to be approximately 0.35 volt and 4 nA, respectively.

KSC-04pd1507

NASA Image and Video Library

2004-07-11

KENNEDY SPACE CENTER, FLA. - Ready for another dive to the NOAA undersea station Aquarius, offshore from Key Largo, the site of the NASA Extreme Environment Mission Operations 6 (NEEMO-6), are (left to right) Monike Schultz, CB Office lead; Bill Todd, project lead; Marc Reagan, mission lead; and Michele Lucas, OPS planner. Todd and Lucas are also the underwater videographer and still photographer, respectively, for the mission. The NEEMO-6 team comprises John Herrington, commander, Tara Ruttley, a biomedical engineer, and astronauts Nick Patrick and Doug Wheelock. The NEEMO-6 mission involves exposing an astronaut/scientist crew to a real mission experience in an extreme environment - Aquarius - to prepare for future space flight. Spacewalk-like diving excursions and field-tests on a variety of biomedical equipment are designed to help astronauts living aboard the International Space Station. To prepare for their 10-day stay, the team had dive training twice a day at the Life Support Buoy, anchored above Aquarius.

Development of advanced polymer nanocomposite capacitors

NASA Astrophysics Data System (ADS)

Mendoza, Miguel

The current development of modern electronics has driven the need for new series of energy storage devices with higher energy density and faster charge/discharge rate. Batteries and capacitors are two of the most widely used energy storage devices. Compared with batteries, capacitors have higher power density and significant higher charge/discharge rate. Therefore, high energy density capacitors play a significant role in modern electronic devices, power applications, space flight technologies, hybrid electric vehicles, portable defibrillators, and pulse power applications. Dielectric film capacitors represent an exceptional alternative for developing high energy density capacitors due to their high dielectric constants, outstanding breakdown voltages, and flexibility. The implementation of high aspect ratio dielectric inclusions such as nanowires into polymer capacitors could lead to further enhancement of its energy density. Therefore, this research effort is focused on the development of a new series of dielectric capacitors composed of nanowire reinforced polymer matrix composites. This concept of nanocomposite capacitors combines the extraordinary physical and chemical properties of the one-dimension (1D) nanoceramics and high dielectric strength of polymer matrices, leading to a capacitor with improved dielectric properties and energy density. Lead-free sodium niobate (NaNbO3) and lead-containing lead magnesium niobate-lead titanate (0.65PMN-0.35PT) nanowires were synthesized following hydrothermal and sol-gel approaches, respectively. The as-prepared nanowires were mixed with a polyvinylidene fluoride (PVDF) matrix using solution-casting method for nanocomposites fabrication. The dielectric constants and breakdown voltages of the NaNbO3/PVDF and 0.65PMN-0.35PT/PVDF nanocomposites were measured under different frequency ranges and temperatures in order to determine their maximum energy (J/cm3) and specific (J/g) densities. The electrical properties of the synthesized nanoceramics were compared with commercially available barium titanate (BaTiO3) and lead zirconate titanate Pb(ZrxTi1-x)O3 powders embedded into a PVDF matrix. The resulting dielectric film capacitors represent an excellent alternative energy storage device for future high energy density applications.

Robonaut 2 - Preparing for Intra-Vehicular Mobility on the International Space Station

NASA Technical Reports Server (NTRS)

Badger, Julia; Diftler, Myron; Hulse, Aaron; Taylor, Ross

2013-01-01

Robonaut 2 (R2) has been undergoing experimental trials on board the International Space Station (ISS) for more than a year. This upper-body anthropomorphic robotic system shown in Figure 1 has been making steady progress after completing its initial checkout. R2 demonstrated free space motion, physically interacted with its human crew mates, manipulated interfaces on its task board and has even used its first tool. This steady growth in capability will lead R2 to its next watershed milestone. Developers are currently testing prototype robotic climbing appendages and a battery backpack in preparation of sending flight versions of both subsystems to the ISS in late 2013. Upon integration of its new components, R2 will be able to go mobile inside the space station with a twofold agenda. First, R2 will learn to maneuver in microgravity in the best possible laboratory for such a task. Second, it will start providing early payback to the ISS program by helping with intra-vehicular (IVA) maintenance tasks. The experience gained inside the ISS will be invaluable in reducing risk when R2 moves to its next stage and is deployed as an extra-vehicular (EVA) tool. Even on its current fixed base stanchion, R2 has already shown its capability of performing several maintenance tasks on the ISS. It has measured the air flow through one of the stations vents and provided previously unavailable real time flow data to ground operators. R2 has cleaned its first handrail, exciting some crew members that perhaps Saturday morning housekeeping on the station may someday become a task they can hand off to their robotic colleague. Other tasks, including using radio frequency identification (RFID) tools for inventory tasks or vacuuming air filters, have also been suggested and will be explored. Once mobile, R2 will take on these tasks and more to free up crew time for more important science and exploration pursuits. In addition to task exploration, research and testing is happening on orbit to prepare for R2 mobility operations. The current vision system in R2 s head is being used to identify and localize IVA handrails throughout the US Lab and ground control software is being updated and integrated in advance of supporting mobility operations.

Preparing Students in Online Debates with Worked Examples

ERIC Educational Resources Information Center

Tollison, Scott; Xie, Kui

2012-01-01

The current study investigates the effects of preparing students for an online debate through a worked example in terms of student perception, participation, and level of cognitive skills. The study found that students prepared for online debate through a worked example participated more frequently, wrote more words or phrases that encouraged the…

Inclusion of Students with Disabilities: Preparation and Practices of Music Educators

ERIC Educational Resources Information Center

Hahn, Kathryn R.

2010-01-01

The purpose of this study was to examine the current professional preparation and practices of music educators in relation to teaching students with formally identified disabilities. Specifically, I created a survey to investigate the preparation of music educators to work with students with disabilities and their use of inclusionary practices in…

The Current State of Middle Management Preparation, Training, and Development in Academic Libraries

ERIC Educational Resources Information Center

Rooney, Michael P.

2010-01-01

This study examined the management experience, preparation, and training possessed by middle managers in academic libraries through the analysis of survey results. The analysis showed both advances in middle management preparation over recent decades and room for improvement in several aspects of management development and training within the…

Initial and Ongoing Teacher Preparation and Support: Current Problems and Possible Solutions

ERIC Educational Resources Information Center

Johnson, Harold A.

2013-01-01

The effective initial preparation and ongoing support of teachers of students who are deaf and hard of hearing has always been a difficult and controversial task. Changes in student demographic characteristics and educational settings, combined with the rapidly diminishing number and diversity of deaf education teacher preparation (DETP) programs,…

Preparing Young Adolescents for a Bright Future--Right Now!

ERIC Educational Resources Information Center

Deering, Paul D.; Martin, Kathryn L.; Buelow, Stephanie M.; Hoffman, Jennifer T.; Cameli, Sandy; Martin, Matt; Walker, Robert E.; O'Neill, Tara B.

2016-01-01

We must prepare young adolescents for a bright future by examining all of our educational practices in terms of their current and future relevance. The education we provide our students must prepare them to address enormously complex issues involving demographics and international relations, environmental and human health, and the development and…

Staying the Course: A Model Leadership Preparation Program that Goes the Distance

ERIC Educational Resources Information Center

Griffin, Leslie L.; Taylor, Thomas R.; Varner, Lynn W.; White, Carole L.

2012-01-01

The Educational Leadership Master's Cohort Program at Delta State University was redesigned in 2011 to reflect current industry standards and streamline the program. Since its inception in the mid-1990s, the program has provided a nationally acclaimed model for principal preparation. The recent redesign focused on preparing school principals to…

Dialogic Praxis in Teacher Preparation: A Discourse Analysis of Mentoring Talk

ERIC Educational Resources Information Center

Bieler, Deborah

2010-01-01

This study examined the complexities of mentoring discourse and agentive teacher preparation. I argue that such an examination is necessary to better prepare student teachers to engage agentively with the powerful status quo in schools. I begin by discussing the intersections of current thinking about mentoring and dialogue, and I describe how…

Preparation of ore blocks for mine leaching by reagent explosion injection

NASA Astrophysics Data System (ADS)

Shevchenko, YuS

2017-02-01

The current drilling-and-blasting operations fail to prepare intact ore body underlying a production horizon for subsequent mining and leaching. It is found that the required preparation quality is possible by means of advanced implementation of ore body discontinuity and filling of the resultant system of joints with active leaching solutions.

Going against the Grain of Accountability Policy: Leadership Preparation for Using Data to Promote Socially Just Outcomes

ERIC Educational Resources Information Center

Mackey, Hollie J.

2015-01-01

Leadership preparation programs are in transition as scholars seek to determine more sophisticated approaches in developing leaders for the increasing demands of accountability policy. This critical conceptual analysis focuses on leadership preparation for the socialization of school leaders. It is intended to reframe current perspectives about…

75 FR 54943 - Notice of Request To Revise a Currently-Approved Information Collection Request: Motor Carrier...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-09

... required consists of grant application preparation, quarterly reports and electronic data documenting the...: 52. Estimated Time per Response: Grant application preparation: 79.5 hours each; quarterly report preparation: 8 hours each; and inspection and data upload: 1 minute each. Expiration Date: February 28, 2011...

Teacher Preparation for Early Childhood: Special Education in Taiwan

ERIC Educational Resources Information Center

Ho, Hua-Kuo

2014-01-01

The purpose of this paper is intended to present the current model of teacher preparation for early childhood special education in Taiwan. Documentary analysis was conducted in the study to collect and analyze the obtained data. The main features of teacher preparation policies for early childhood special education in Taiwan could be summarized…

Taiwanese Model of Teacher Preparation for Early Childhood Education

ERIC Educational Resources Information Center

Ho, Hua-Kuo

2012-01-01

The purpose of this paper is intended to present the current model of teacher preparation for early childhood education in Taiwan. Documentary analysis was employed in the study to collect and analyze the obtained data. The main features of teacher preparation policies for early childhood education in Taiwan could be summarized as: (1) The…

The Importance of Comparative Research in Psychological Preparation of Children.

ERIC Educational Resources Information Center

Peterson, Lizette

Current research indicates that hospitalized children may profit best from preparation for surgery that is individually suited to their particular way of responding to hospitalization. It is likely, however, that preparation treatments will be provided for children in groups. Therefore, an attempt has been made to design and test information and…

Quantum interference effect in electron tunneling through a quantum-dot-ring spin valve

PubMed Central

2011-01-01

Spin-dependent transport through a quantum-dot (QD) ring coupled to ferromagnetic leads with noncollinear magnetizations is studied theoretically. Tunneling current, current spin polarization and tunnel magnetoresistance (TMR) as functions of the bias voltage and the direct coupling strength between the two leads are analyzed by the nonequilibrium Green's function technique. It is shown that the magnitudes of these quantities are sensitive to the relative angle between the leads' magnetic moments and the quantum interference effect originated from the inter-lead coupling. We pay particular attention on the Coulomb blockade regime and find the relative current magnitudes of different magnetization angles can be reversed by tuning the inter-lead coupling strength, resulting in sign change of the TMR. For large enough inter-lead coupling strength, the current spin polarizations for parallel and antiparallel magnetic configurations will approach to unit and zero, respectively. PACS numbers: PMID:21711779

Role of lead in electrochemical reaction of alloy 600, alloy 690, Ni, Cr, and Fe in water

NASA Astrophysics Data System (ADS)

Hwang, Seong Sik; Kim, Joung Soo; Kim, Ju Yup

2003-08-01

It has been reported that lead causes stress corrosion cracking (SCC) in the secondary side of steam generators (SG) in pressurized water reactors (PWR). The materials of SG tubings are alloy 600, alloy 690, or alloy 800, among which the main alloying elements are Ni, Cr, and Fe. The effect of lead on the electrochemical behaviors of alloy 600 and alloy 690 using an anodic polarization technique was evaluated. We also obtained polarization curves of pure Ni, Cr, and Fe in water containing lead. As the amount of lead in the solution increased, critical current densities and passive current densities of alloy 600 and alloy 690 increased, while the breakdown potential of the alloys decreased. Lead increased critical current density and the passive current of Cr in pH 4 and pH 10. The instability of passive film of steam generator tubings in water containing lead might arise from the instability of Cr passivity.

New synthetic possibilities for the preparation of liquid crystalline dicyclohexyl derivatives

NASA Astrophysics Data System (ADS)

Sasnouski, Genadz; Bezborodov, Vladimir; Dabrowski, Roman S.; Dziaduszek, Jerzy

2000-05-01

A new synthetic approach for the preparation of two- and three ring liquid crystalline compounds possessing trans,trans-dicyclohexyl moiety is proposed and realized. Recently discovered reaction of Grignard reagents with esters leading to 1-substituted cyclopropanoles in the presence of tetraisopropoxytitanium was used as a key stage. Starting from ethyl trans-4-alkylcyclohexancarboxylates the corresponding 6-(4-alkylcyclohexyl)-3-alkyl (or aryl) cyclohex-2-en-1-ones have been prepared. Their catalytic hydrogenation in the base media gave mainly saturated trans, trans-ketones which are liquid crystalline and have been used also as a promising intermediate products for the preparation of different kinds of other LC compounds.

Towards a 20 kA high temperature superconductor current lead module using REBCO tapes

NASA Astrophysics Data System (ADS)

Heller, R.; Bagrets, N.; Fietz, W. H.; Gröner, F.; Kienzler, A.; Lange, C.; Wolf, M. J.

2018-01-01

Most of the large fusion devices presently under construction or in operation consisting of superconducting magnets like EAST, Wendelstein 7-X (W7-X), JT-60SA, and ITER, use high temperature superconductor (HTS) current leads (CL) to reduce the cryogenic load and operational cost. In all cases, the 1st generation HTS material Bi-2223 is used which is embedded in a low-conductivity matrix of AgAu. In the meantime, industry worldwide concentrates on the production of the 2nd generation HTS REBCO material because of the better field performance in particular at higher temperature. As the new material can only be produced in a multilayer thin-film structure rather than as a multi-filamentary tape, the technology developed for Bi-2223-based current leads cannot be transferred directly to REBCO. Therefore, several laboratories are presently investigating the design of high current HTS current leads made of REBCO. Karlsruhe Institute of Technology is developing a 20 kA HTS current lead using brass-stabilized REBCO tapes—as a further development to the Bi-2223 design used in the JT-60SA current leads. The same copper heat exchanger module as in the 20 kA JT-60SA current lead will be used for simplicity, which will allow a comparison of the newly developed REBCO CL with the earlier produced and investigated CL for JT-60SA. The present paper discusses the design and accompanying test of single tape and stack REBCO mock-ups. Finally, the fabrication of the HTS module using REBCO stacks is described.

Histochemical detection of lead and zinc in plant tissues

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

Tung, G.; Temple, P.J.

1975-01-01

Histochemical studies on uptake and localization of lead and zinc in plant tissues were carried out. A histochemical stain technique was developed to differentiate zinc from lead. Lead was detected in plant tissues by soaking fresh plant materials in freshly prepared sodium rhodizonate stain (0.2% Na rhodizonate acidified to pH3 with glacial acetic acid). Samples were evacuated 5 min and soaked for 30 min before embedding in the congealed stain, then sectioned with a cryostat and examined under a light microscope. Lead particles in plant tissues were stained scarlet-red. Gelatinous, proteinaceous or saccharic embedding materials normally used to prepare plantmore » sampled for sectioning in the cryostat interfered with the color reaction. Sectioning plant samples without staining whole tissues resulted in a weakened response to the stain. Color of stained sample materials were retained for several months if stored in a frozen condition. This technique was used to detect lead both inside and on the surface of plant samples collected in the vicinity of highway and industrial lead sources and to trace the pathways of lead uptake from the air or from contaminated soils. A sodium rhodizonate technique was also developed to be specific for zinc in plant tissues. Plant samples were soaked in a neutral Na-rhodizonate in phosphate buffer at pH 7.5 for observation. The color of zinc developed to produce a purplish or reddish-brown color.« less

Valley dependent transport in graphene L junction

NASA Astrophysics Data System (ADS)

Chan, K. S.

2018-05-01

We studied the valley dependent transport in graphene L junctions connecting an armchair lead and a zigzag lead. The junction can be used in valleytronic devices and circuits. Electrons injected from the armchair lead into the junction is not valley polarized, but they can become valley polarized in the zigzag lead. There are Fermi energies, where the current in the zigzag lead is highly valley polarized and the junction is an efficient generator of valley polarized current. The features of the valley polarized current depend sensitively on the widths of the two leads, as well as the number of dimers in the armchair lead, because this number has a sensitive effect on the band structure of the armchair lead. When an external potential is applied to the junction, the energy range with high valley polarization is enlarged enhancing its function as a generator of highly valley polarized current. The scaling behavior found in other graphene devices is also found in L junctions, which means that the results presented here can be extended to junctions with larger dimensions after appropriate scaling of the energy.