A Research Needs Assessment for waste plastics recycling: Volume 1, Executive summary. Final report

Energy Technology Data Exchange (ETDEWEB)

NONE

1994-12-01

This first volume provides a summary of the entire project. The study utilized the talents of a large number of participants, including a significant number of peer reviewers from industrial companies, government agencies, and research institutes. in addition, an extensive analysis of relevant literature was carried out. In considering the attractiveness of recycling technologies that are alternatives to waste-to-energy combustion units, a systems approach was utilized. Collection of waste streams containing plastics, sortation, and reclamation of plastics and plastic mixtures, reprocessing or chemical conversion of the reclaimed polymers, and the applicability of the products to specific market segments have been analyzed in the study.

Cortical and Subcortical Structural Plasticity Associated with the Glioma Volumes in Patients with Cerebral Gliomas Revealed by Surface-Based Morphometry

Directory of Open Access Journals (Sweden)

Jinping Xu

2017-06-01

Full Text Available Postlesional plasticity has been identified in patients with cerebral gliomas by inducing a large functional reshaping of brain networks. Although numerous non-invasive functional neuroimaging methods have extensively investigated the mechanisms of this functional redistribution in patients with cerebral gliomas, little effort has been made to investigate the structural plasticity of cortical and subcortical structures associated with the glioma volume. In this study, we aimed to investigate whether the contralateral cortical and subcortical structures are able to actively reorganize by themselves in these patients. The compensation mechanism following contralateral cortical and subcortical structural plasticity is considered. We adopted the surface-based morphometry to investigate the difference of cortical and subcortical gray matter (GM volumes in a cohort of 14 healthy controls and 13 patients with left-hemisphere cerebral gliomas [including 1 patients with World Health Organization (WHO I, 8 WHO II, and 4 WHO III]. The glioma volume ranges from 5.1633 to 208.165 cm2. Compared to healthy controls, we found significantly increased GM volume of the right cuneus and the left thalamus, as well as a trend toward enlargement in the right globus pallidus in patients with cerebral gliomas. Moreover, the GM volumes of these regions were positively correlated with the glioma volumes of the patients. These results provide evidence of cortical and subcortical enlargement, suggesting the usefulness of surface-based morphometry to investigate the structural plasticity. Moreover, the structural plasticity might be acted as the compensation mechanism to better fulfill its functions in patients with cerebral gliomas as the gliomas get larger.

Finite element analysis of cylindrical indentation for determining plastic properties of materials in small volumes

International Nuclear Information System (INIS)

Lu, Y Charles; Kurapati, Siva N V R K; Yang Fuqian

2008-01-01

The cylindrical indentation is analysed, using the finite element method, for determining the plastic properties of elastic-plastic materials and the effect of strain hardening. The results are compared with those obtained from spherical indentation, the commonly used technique for measuring plastic properties of materials in small volumes. The analysis shows that the deformation under a cylindrical indenter quickly reaches a fully plastic state and that the size (diameter) of the plastic zone remains constant during further indentation. The indentation load is proportional to the indentation depth at large indentation depth, from which the indentation pressure P m at the onset of yielding can be readily extrapolated. The analysis of cylindrical indentation suggests that it does not need parameters such as impression radius (a) and contact stiffness (S) for determining the plastic behaviour of materials. Thus, the cylindrical indentation can suppress the uncertainties in measuring material properties

ALE finite volume method for free-surface Bingham plastic fluids with general curvilinear coordinates

International Nuclear Information System (INIS)

Nagai, Katsuaki; Ushijima, Satoru

2010-01-01

A numerical prediction method has been proposed to predict Bingham plastic fluids with free-surface in a two-dimensional container. Since the linear relationships between stress tensors and strain rate tensors are not assumed for non-Newtonian fluids, the liquid motions are described with Cauchy momentum equations rather than Navier-Stokes equations. The profile of a liquid surface is represented with the two-dimensional curvilinear coordinates which are represented in each computational step on the basis of the arbitrary Lagrangian-Eulerian (ALE) method. Since the volumes of the fluid cells are transiently changed in the physical space, the geometric conservation law is applied to the finite volume discretizations. As a result, it has been shown that the present method enables us to predict reasonably the Bingham plastic fluids with free-surface in a container.

ALE finite volume method for free-surface Bingham plastic fluids with general curvilinear coordinates

Science.gov (United States)

Nagai, Katsuaki; Ushijima, Satoru

2010-06-01

A numerical prediction method has been proposed to predict Bingham plastic fluids with free-surface in a two-dimensional container. Since the linear relationships between stress tensors and strain rate tensors are not assumed for non-Newtonian fluids, the liquid motions are described with Cauchy momentum equations rather than Navier-Stokes equations. The profile of a liquid surface is represented with the two-dimensional curvilinear coordinates which are represented in each computational step on the basis of the arbitrary Lagrangian-Eulerian (ALE) method. Since the volumes of the fluid cells are transiently changed in the physical space, the geometric conservation law is applied to the finite volume discretizations. As a result, it has been shown that the present method enables us to predict reasonably the Bingham plastic fluids with free-surface in a container.

XVIII Mendeleev congress on general and applied chemistry. Summaries of reports in five volumes. Volume 5. IV Russian-French symposium Supramolecular systems in chemistry and biology. II Russian-Indian symposium on organic chemistry. International symposium on present-day radiochemistry Radiochemistry: progress and prospects. International symposium Green chemistry, stable evolution and social responsibility of chemists. Symposium Nucleophilic hydrogen substitution in aromatic systems and related reactions

International Nuclear Information System (INIS)

2007-01-01

The 5 volume of the XVIII Mendeleev congress on general and applied chemistry includes summaries of reports on the subjects of sypramolecular systems in chemistry and biology, organic chemistry, modern radiochemistry, green chemistry - development and social responsibility of chemists, nucleophilic hydrogen substitution in aromatic systems and related chemical reactions [ru

The economics of plastic surgery practices: trends in income, procedure mix, and volume.

Science.gov (United States)

Krieger, Lloyd M; Lee, Gordon K

2004-07-01

Anecdotally, plastic surgeons have complained of working harder for the same or less income in recent years. They also complain of falling fees for reconstructive surgery and increasing competition for cosmetic surgery. This study examined these notions using the best available data. To gain a better understanding of the current plastic surgery market, plastic surgeon incomes, fees, volume, and relative mix of cosmetic and reconstructive surgery were analyzed between the years 1992 and 2002. To gain a broader perspective, plastic surgeon income trends were then compared with those of other medical specialties and of nonmedical professions. The data show that in real dollars, plastic surgeon incomes have remained essentially steady in recent years, despite plastic surgeons increasing their surgery load by an average of 41 percent over the past 10 years. The overall income trend is similar to that of members of other medical specialties and other nonmedical professionals. The average practice percentage of cosmetic surgery was calculated and found to have increased from 27 percent in 1992 to 58 percent in 2002. This most likely can be explained by the findings that real dollar fees collected for cosmetic surgery have decreased very slightly, whereas those for reconstructive procedures have experienced sharp declines. This study demonstrates that plastic surgeons have adjusted their practice profiles in recent years. They have increased their case loads and shifted their practices toward cosmetic surgery, most likely with the goal of maintaining their incomes. The strategy appears to have been successful in the short term. However, with increasing competition and falling prices for cosmetic surgery, it may represent a temporary bulwark for plastic surgeon incomes unless other steps are taken.

Development of metallic molds for the large volume plastic scintillator fabrication

International Nuclear Information System (INIS)

Calvo, Wilson A.P.; Vieira, Jose M.; Rela, Paulo R.; Bruzinga, Wilson A.; Araujo, Eduardo P.; Costa Junior, Nelson P.; Hamada, Margarida M.

1997-01-01

The plastic scintillators are radiation detectors made of organic fluorescent compounds dissolved in a solidified polymer matrix. The manufacturing process of large volume detectors (55 liters) at low cost, by polymerization of the styrene monomer plus PPO and POPOP scintillators, was studied in this paper. Metallic molds of ASTM 1200 aluminum and AISI 304 stainless steel were produced by TIG welding process since the polymerization reaction is very exothermic. The measurements of transmittance, luminescence, X-ray fluorescence and light output were carried out in the plastic scintillators made using different metallic molds. The characterization results of the detectors produced in an open system using ASTM 1200 aluminum mold show that there is not quality change in the scintillator, even with aluminum being considered as unstable for styrene monomer. Therefore, the ASTM 1200 aluminum was found to be the best alternative to produce the detector by an open system polymerization. (author). 11 refs., 8 figs., 1 tab

Theoretical chemistry periodicities in chemistry and biology

CERN Document Server

Eyring, Henry

1978-01-01

Theoretical Chemistry: Periodicities in Chemistry and Biology, Volume 4 covers the aspects of theoretical chemistry. The book discusses the stably rotating patterns of reaction and diffusion; the chemistry of inorganic systems exhibiting nonmonotonic behavior; and population cycles. The text also describes the mathematical modeling of excitable media in neurobiology and chemistry; oscillating enzyme reactions; and oscillatory properties and excitability of the heart cell membrane. Selected topics from the theory of physico-chemical instabilities are also encompassed. Chemists, mechanical engin

Highly ordered nanowire arrays on plastic substrates for ultrasensitive flexible chemical sensors.

Science.gov (United States)

McAlpine, Michael C; Ahmad, Habib; Wang, Dunwei; Heath, James R

2007-05-01

The development of a robust method for integrating high-performance semiconductors on flexible plastics could enable exciting avenues in fundamental research and novel applications. One area of vital relevance is chemical and biological sensing, which if implemented on biocompatible substrates, could yield breakthroughs in implantable or wearable monitoring systems. Semiconducting nanowires (and nanotubes) are particularly sensitive chemical sensors because of their high surface-to-volume ratios. Here, we present a scalable and parallel process for transferring hundreds of pre-aligned silicon nanowires onto plastic to yield highly ordered films for low-power sensor chips. The nanowires are excellent field-effect transistors, and, as sensors, exhibit parts-per-billion sensitivity to NO2, a hazardous pollutant. We also use SiO2 surface chemistries to construct a 'nano-electronic nose' library, which can distinguish acetone and hexane vapours via distributed responses. The excellent sensing performance coupled with bendable plastic could open up opportunities in portable, wearable or even implantable sensors.

Highly ordered nanowire arrays on plastic substrates for ultrasensitive flexible chemical sensors

Science.gov (United States)

McAlpine, Michael C.; Ahmad, Habib; Wang, Dunwei; Heath, James R.

2007-05-01

The development of a robust method for integrating high-performance semiconductors on flexible plastics could enable exciting avenues in fundamental research and novel applications. One area of vital relevance is chemical and biological sensing, which if implemented on biocompatible substrates, could yield breakthroughs in implantable or wearable monitoring systems. Semiconducting nanowires (and nanotubes) are particularly sensitive chemical sensors because of their high surface-to-volume ratios. Here, we present a scalable and parallel process for transferring hundreds of pre-aligned silicon nanowires onto plastic to yield highly ordered films for low-power sensor chips. The nanowires are excellent field-effect transistors, and, as sensors, exhibit parts-per-billion sensitivity to NO2, a hazardous pollutant. We also use SiO2 surface chemistries to construct a `nano-electronic nose' library, which can distinguish acetone and hexane vapours via distributed responses. The excellent sensing performance coupled with bendable plastic could open up opportunities in portable, wearable or even implantable sensors.

Solution of the square lid-driven cavity flow of a Bingham plastic using the finite volume method

OpenAIRE

Syrakos, Alexandros; Georgiou, Georgios C.; Alexandrou, Andreas N.

2016-01-01

We investigate the performance of the finite volume method in solving viscoplastic flows. The creeping square lid-driven cavity flow of a Bingham plastic is chosen as the test case and the constitutive equation is regularised as proposed by Papanastasiou [J. Rheol. 31 (1987) 385-404]. It is shown that the convergence rate of the standard SIMPLE pressure-correction algorithm, which is used to solve the algebraic equation system that is produced by the finite volume discretisation, severely det...

The plasticity of extracellular fluid homeostasis in insects.

Science.gov (United States)

Beyenbach, Klaus W

2016-09-01

In chemistry, the ratio of all dissolved solutes to the solution's volume yields the osmotic concentration. The present Review uses this chemical perspective to examine how insects deal with challenges to extracellular fluid (ECF) volume, solute content and osmotic concentration (pressure). Solute/volume plots of the ECF (hemolymph) reveal that insects tolerate large changes in all three of these ECF variables. Challenges beyond those tolerances may be 'corrected' or 'compensated'. While a correction simply reverses the challenge, compensation accommodates the challenge with changes in the other two variables. Most insects osmoregulate by keeping ECF volume and osmotic concentration within a wide range of tolerance. Other insects osmoconform, allowing the ECF osmotic concentration to match the ambient osmotic concentration. Aphids are unique in handling solute and volume loads largely outside the ECF, in the lumen of the gut. This strategy may be related to the apparent absence of Malpighian tubules in aphids. Other insects can suspend ECF homeostasis altogether in order to survive extreme temperatures. Thus, ECF homeostasis in insects is highly dynamic and plastic, which may partly explain why insects remain the most successful class of animals in terms of both species number and biomass. © 2016. Published by The Company of Biologists Ltd.

Progress report on nuclear science and technology in China (Vol.3). Proceedings of academic annual meeting of China Nuclear Society in 2013, No.4--Nuclear chemistry and radiation chemistry sub-volume

International Nuclear Information System (INIS)

2014-05-01

Progress report on nuclear science and technology in China (Vol. 3) includes 24 articles which are communicated on the third national academic annual meeting of China Nuclear Society. There are 10 books totally. This is the fourth one, the content is about Nuclear chemistry and radiation chemistry sub-volume

Theoretical chemistry in Belgium a topical collection from theoretical chemistry accounts

CERN Document Server

Champagne, Benoît; De Proft, Frank; Leyssens, Tom

2014-01-01

Readers of this volume can take a tour around the research locations in Belgium which are active in theoretical and computational chemistry. Selected researchers from Belgium present research highlights of their work. Originally published in the journal Theoretical Chemistry Accounts, these outstanding contributions are now available in a hardcover print format. This volume will be of benefit in particular to those research groups and libraries that have chosen to have only electronic access to the journal. It also provides valuable content for all researchers in theoretical chemistry.

Plastics, the environment and human health: current consensus and future trends.

Science.gov (United States)

Thompson, Richard C; Moore, Charles J; vom Saal, Frederick S; Swan, Shanna H

2009-07-27

Plastics have transformed everyday life; usage is increasing and annual production is likely to exceed 300 million tonnes by 2010. In this concluding paper to the Theme Issue on Plastics, the Environment and Human Health, we synthesize current understanding of the benefits and concerns surrounding the use of plastics and look to future priorities, challenges and opportunities. It is evident that plastics bring many societal benefits and offer future technological and medical advances. However, concerns about usage and disposal are diverse and include accumulation of waste in landfills and in natural habitats, physical problems for wildlife resulting from ingestion or entanglement in plastic, the leaching of chemicals from plastic products and the potential for plastics to transfer chemicals to wildlife and humans. However, perhaps the most important overriding concern, which is implicit throughout this volume, is that our current usage is not sustainable. Around 4 per cent of world oil production is used as a feedstock to make plastics and a similar amount is used as energy in the process. Yet over a third of current production is used to make items of packaging, which are then rapidly discarded. Given our declining reserves of fossil fuels, and finite capacity for disposal of waste to landfill, this linear use of hydrocarbons, via packaging and other short-lived applications of plastic, is simply not sustainable. There are solutions, including material reduction, design for end-of-life recyclability, increased recycling capacity, development of bio-based feedstocks, strategies to reduce littering, the application of green chemistry life-cycle analyses and revised risk assessment approaches. Such measures will be most effective through the combined actions of the public, industry, scientists and policymakers. There is some urgency, as the quantity of plastics produced in the first 10 years of the current century is likely to approach the quantity produced in the

Plastics, the environment and human health: current consensus and future trends

Science.gov (United States)

Thompson, Richard C.; Moore, Charles J.; vom Saal, Frederick S.; Swan, Shanna H.

2009-01-01

Plastics have transformed everyday life; usage is increasing and annual production is likely to exceed 300 million tonnes by 2010. In this concluding paper to the Theme Issue on Plastics, the Environment and Human Health, we synthesize current understanding of the benefits and concerns surrounding the use of plastics and look to future priorities, challenges and opportunities. It is evident that plastics bring many societal benefits and offer future technological and medical advances. However, concerns about usage and disposal are diverse and include accumulation of waste in landfills and in natural habitats, physical problems for wildlife resulting from ingestion or entanglement in plastic, the leaching of chemicals from plastic products and the potential for plastics to transfer chemicals to wildlife and humans. However, perhaps the most important overriding concern, which is implicit throughout this volume, is that our current usage is not sustainable. Around 4 per cent of world oil production is used as a feedstock to make plastics and a similar amount is used as energy in the process. Yet over a third of current production is used to make items of packaging, which are then rapidly discarded. Given our declining reserves of fossil fuels, and finite capacity for disposal of waste to landfill, this linear use of hydrocarbons, via packaging and other short-lived applications of plastic, is simply not sustainable. There are solutions, including material reduction, design for end-of-life recyclability, increased recycling capacity, development of bio-based feedstocks, strategies to reduce littering, the application of green chemistry life-cycle analyses and revised risk assessment approaches. Such measures will be most effective through the combined actions of the public, industry, scientists and policymakers. There is some urgency, as the quantity of plastics produced in the first 10 years of the current century is likely to approach the quantity produced in the

Safety in Academic Chemistry Laboratories: Volume 2. Accident Prevention for Faculty and Administrators, 7th Edition.

Science.gov (United States)

American Chemical Society, Washington, DC.

This book contains volume 2 of 2 and describes safety guidelines for academic chemistry laboratories to prevent accidents for college and university students. Contents include: (1) "Organizing for Accident Prevention"; (2) "Personal Protective Equipment"; (3) "Labeling"; (4) "Material Safety Data Sheets (MSDSs)"; (5) "Preparing for Medical…

Onco plastic volume replacement with latissimus dorsi myocutaneous flap in patients with large ptotic breasts. Is it feasible?

International Nuclear Information System (INIS)

El-Marakby, H.H.; Kotb, M.H.

2011-01-01

Onco plastic breast conservative surgery has evolved as a safe alternative to the standard mastectomy in the treatment of early breast cancer. The procedure involves tumour resection with an adequate safety margin and either breast reshaping with volume displacement procedures (large or pt otic breasts) or volume replacement with latissimus dorsi myocutaneous flap (LDF) (small to medium sized non-ptotic breasts). A contra lateral mastopexy procedure is usually necessary with the volume displacement Onco plastic surgery, a procedure that is often rejected by a significant number of patients. This limits the choice of the reconstruction of breast defects in such patients to autologous tissues i.e. LDF. Aim: Aim is to evaluate the feasibility of volume replacement onco plastic breast conservative surgery with lemmatise dorsi myocutaneous flaps for patients with large ptotic breasts. This involves testing the oncologic safety in terms of adequate safety margin, the complications rate and the final cosmetic outcome. The loco regional recurrence rate will be recorded and compared with oncoplastic volume displacement for similar sized breast defects. Patients and methods: A group of 50 female patients with early breast cancers (T2) who presented to the department of surgery at the National Cancer Institute, Cairo, Egypt in the period between carried out in all patient groups and was used to annually follow up the patients. All patients were detected with T2 NO breast cancer by both clinical and radiological examinations. All patients underwent partial mastectomy was and reconstruction with LDFs. Results: The average age at presentation was 46.5 ± 9 years and the range was 26-65 years. Most of the patients were subjected to partial mastectomy in 30 patients (60%), excision of a single quadrant from the four major quadrants was carried out in 15 patients (30%) where skin sparing wide local excision was carried out in only five patients (10%). The safety margin ranged from

The appearance of plasticity on the blocks surfaces in geological media

Energy Technology Data Exchange (ETDEWEB)

Sibiryakov, Boris P., E-mail: sibiryakovbp@ipgg.sbras.ru [Trofimuk Institute of Oil and Gas Geology and Geophysics SB RAS, Novosibirsk, 630090, Russia and Novosibirsk State University, Novosibirsk, 630090 (Russian Federation)

2014-11-14

In present the elasticity and plasticity are absolutely different models of solids, which are not relate to each other. The experimental observations show, that the plasticity arrives and localizes on the surfaces of structures, which contain solid samples. The transition in special state, where a small part of solid volume is in plastic state, while the main part of volume is in elastic state not be describe by classical continuum Cauchy and Poisson model. This classical model requires two alternative states. Either is elastic state in the all volume or plastic one for all elementary volume too. However, the structured model of space gives us a possibility to describe this complicate state. In this paper shown that the sliding surfaces divided to each other by distances equal to the average sizes of microstructures, in the contrary of classical plasticity, where they have not characteristic distance. The energy of plastic transition is very small, because the main part of volume is elastic body. This description means the smooth transition from elasticity to plasticity in vicinity of sliding surfaces.

The chemistry of the actinide elements. Volume I

International Nuclear Information System (INIS)

Katz, J.J.; Seaborg, G.T.; Morss, L.R.

1986-01-01

The Chemistry of the Actinide Elements is a comprehensive, contemporary and authoritative exposition of the chemistry and related properties of the 5f series of elements: actinium, thorium, protactinium, uranium and the first eleven. This second edition has been completely restructured and rewritten to incorporate current research in all areas of actinide chemistry and chemical physics. The descriptions of each element include accounts of their history, separation, metallurgy, solid-state chemistry, solution chemistry, thermo-dynamics and kinetics. Additionally, separate chapters on spectroscopy, magnetochemistry, thermodynamics, solids, the metallic state, complex ions and organometallic compounds emphasize the comparative chemistry and unique properties of the actinide series of elements. Comprehensive lists of properties of all actinide compounds and ions in solution are given, and there are special sections on such topics as biochemistry, superconductivity, radioisotope safety, and waste management, as well as discussion of the transactinides and future elements

Chemistry of the actinide elements. Second edition

International Nuclear Information System (INIS)

Katz, J.J.; Seaborg, G.T.; Morss, L.R.

1987-01-01

This is an exhaustive, updated discourse on the chemistry of Actinides, Volume 1 contains a systematic coverage of the elements Ac, Th, Pa, U, Np, and Pu, which constitutes Part 1 of the work. The characterization of each element is discussed in terms of its nuclear properties, occurrence, preparation, atomic and metallic properties, chemistry of specific compounds, and solution chemistry. The first part of Volume 2 follows the same format as Volume 1 but is confined to the elements Am, Cm, Bk, Cf, and Es, plus a more condensed coverage of the Transeinsteinium elements (Fm, Md, No, Lw, and 104-109). Part 2 of this volume is devoted to a discussion of the actinide elements in general, with a specific focus on electronic spectra, thermodynamic and magnetic properties, the metallic state, structural chemistry, solution kinetics, organometallic chemistry for σ- and π-bonded compounds, and some concluding remarks on the superheavy elements

EPRI BWR Water Chemistry Guidelines Revision

International Nuclear Information System (INIS)

Garcia, Susan E.; Giannelli, Joseph F.

2014-01-01

BWRVIP-190: BWR Water Chemistry Guidelines – 2008 Revision has been revised. The revision committee consisted of U.S. and non-U.S. utilities (members of the BWR Vessel and Internals Protection (BWRVIP) Mitigation Committee), reactor system manufacturers, fuel suppliers, and EPRI and industry experts. The revised document, BWRVIP-190 Revision 1, was completely reformatted into two volumes, with a simplified presentation of water chemistry control, diagnostic and good practice parameters in Volume 1 and the technical bases in Volume 2, to facilitate use. The revision was developed in parallel and in coordination with preparation of the Fuel Reliability Guidelines Revision 1: BWR Fuel Cladding Crud and Corrosion. Guidance is included for plants operating under normal water chemistry (NWC), moderate hydrogen water chemistry (HWC-M), and noble metal application (GE-Hitachi NobleChem™) plus hydrogen injection. Volume 1 includes significant changes to BWR feedwater and reactor water chemistry control parameters to provide increased assurance of intergranular stress corrosion cracking (IGSCC) mitigation of reactor materials and fuel reliability during all plant conditions, including cold shutdown (≤200°F (93°C)), startup/hot standby (>200°F (93°C) and ≤ 10%) and power operation (>10% power). Action Level values for chloride and sulfate have been tightened to minimize environmentally assisted cracking (EAC) of all wetted surfaces, including those not protected by hydrogen injection, with or without noble metals. Chemistry control guidance has been enhanced to minimize shutdown radiation fields by clarifying targets for depleted zinc oxide (DZO) injection while meeting requirements for fuel reliability. Improved tabular presentations of parameter values explicitly indicate levels at which actions are to be taken and required sampling frequencies. Volume 2 provides the technical bases for BWR water chemistry control for control of EAC, flow accelerated corrosion

Safety in Academic Chemistry Laboratories: Volume 1. Accident Prevention for College and University Students, 7th Edition.

Science.gov (United States)

American Chemical Society, Washington, DC.

This book contains volume 1 of 2 and describes safety guidelines for academic chemistry laboratories to prevent accidents for college and university students. Contents include: (1) "Your Responsibility for Accident Prevention"; (2) "Guide to Chemical Hazards"; (3) "Recommended Laboratory Techniques"; and (4) "Safety Equipment and Emergency…

Effect of volume change of coal during plastic and resolidifying phase on the internal gas pressure in coke ovens; Sekitan nanka saikoka katei ni okeru taiseki henka ga cokes ro no nanka yoyu sonai gas atsu ni oyobosu eikyo

Energy Technology Data Exchange (ETDEWEB)

Nomura, S; Arima, T [Nippon Steel Corp., Tokyo (Japan)

2000-08-01

The coking pressure in coke oven, which is caused by the internal gas pressure in the coal plastic layer, is determined by the gas permeability of the layer. The gas permeability of the plastic layer depends on its density as well as the physical property of the plastic coal itself The plastic layer is between the coke layer and the coal layer and the effect of the volume change of these outer layers, i.e. contraction and compression, on the density and the internal gas pressure of the plastic layer was studied. Sandwich carbonization test, where different coals were charged in the test coke oven, showed that the internal gas pressure in the plastic layer depends not only on the one kind of coal in plastic phase but also on the other kind of coal in resolidifying phase near the oven walls. The relative volume of coke transformed from the unit volume of coal was measured using X-ray CT scanner and it varied greatly across the coke oven width depending on the kinds of coals. The volume change of coal during plastic and resolidifying phase affects the density and the internal gas pressure of the plastic layer The relative volume of semicoke and coke transformed from the unit volume of coal near the oven walls is higher for a high coking pressure coal than that for a low coking pressure coal. This leads to the high density of the plastic layer and the generation of dangerously high internal gas pressure in the oven centre. (author)

Environment friendly solutions of plastics waste management

International Nuclear Information System (INIS)

Pirzada, F.N.; Riffat, T.; Pirzada, M.D.S.

1997-01-01

The use of plastics is growing worldwide. Consequently, the volume of plastic waste is also increasing. Presently, more than 100 million tons per year of plastic is being produced globally. In U.S. alone more than 10 million tons of plastic is being dumped in landfills as waste, where it can persist for decades. This has resulted in exhausting old landfills. Public awareness on environment is also making it difficult to find new sites for landfills. This has led to increased emphasis on treatment and recycling of plastic wastes. Volume reduction of plastic waste has some unique problems. They arise from the intrinsic chemical inertness of polymeric materials and toxic nature of their degradation byproducts. The paper reviews the present state of plastic waste management including land filling, incineration and recycling technologies. The technical problems associated with each of these processes have been discussed. There is also brief description of ongoing R and D for finding improved methods of plastic waste handling with their promises and problems. The role of tougher legislation in developing better recycling methods and degradable plastics has also been evaluated. The claims made by the proponents of degradable polymers have also been critically reviewed. (authors)

Condensate and feedwater systems, pumps, and water chemistry. Volume seven

International Nuclear Information System (INIS)

Anon.

1986-01-01

Subject matter includes condensate and feedwater systems (general features of condensate and feedwater systems, condenser hotwell level control, condensate flow, feedwater flow), pumps (principles of fluid flow, types of pumps, centrifugal pumps, positive displacement pumps, jet pumps, pump operating characteristics) and water chemistry (water chemistry fundamentals, corrosion, scaling, radiochemistry, water chemistry control processes, water pretreatment, PWR water chemistry, BWR water chemistry, condenser circulating water chemistry

Americium behaviour in plastic vessels

Energy Technology Data Exchange (ETDEWEB)

Legarda, F.; Herranz, M. [Departamento de Ingenieria Nuclear y Mecanica de Fluidos, Escuela Tecnica Superior de Ingenieria de Bilbao, Universidad del Pais Vasco (UPV/EHU), Alameda de Urquijo s/n, 48013 Bilbao (Spain); Idoeta, R., E-mail: raquel.idoeta@ehu.e [Departamento de Ingenieria Nuclear y Mecanica de Fluidos, Escuela Tecnica Superior de Ingenieria de Bilbao, Universidad del Pais Vasco (UPV/EHU), Alameda de Urquijo s/n, 48013 Bilbao (Spain); Abelairas, A. [Departamento de Ingenieria Nuclear y Mecanica de Fluidos, Escuela Tecnica Superior de Ingenieria de Bilbao, Universidad del Pais Vasco (UPV/EHU), Alameda de Urquijo s/n, 48013 Bilbao (Spain)

2010-07-15

The adsorption of {sup 241}Am dissolved in water in different plastic storage vessels was determined. Three different plastics were investigated with natural and distilled waters and the retention of {sup 241}Am by these plastics was studied. The same was done by varying vessel agitation time, vessel agitation speed, surface/volume ratio of water in the vessels and water pH. Adsorptions were measured to be between 0% and 70%. The adsorption of {sup 241}Am is minimized with no water agitation, with PET or PVC plastics, and by water acidification.

Americium behaviour in plastic vessels

International Nuclear Information System (INIS)

Legarda, F.; Herranz, M.; Idoeta, R.; Abelairas, A.

2010-01-01

The adsorption of 241 Am dissolved in water in different plastic storage vessels was determined. Three different plastics were investigated with natural and distilled waters and the retention of 241 Am by these plastics was studied. The same was done by varying vessel agitation time, vessel agitation speed, surface/volume ratio of water in the vessels and water pH. Adsorptions were measured to be between 0% and 70%. The adsorption of 241 Am is minimized with no water agitation, with PET or PVC plastics, and by water acidification.

Utilization of water soluble plastics for radiological control within nuclear power plants

International Nuclear Information System (INIS)

Smith, R.J.; Deltete, C.P.; Homyk, W.A.; Kasprzak, L.; Robinson, P.J.

1989-01-01

The utilization of plastic products for radioactive contamination control within nuclear power facilities currently results in relatively large volumes of waste requiring disposal as low-level radioactive waste. The utilization of a polymer resin product that possesses comparable physical attributes to currently utilized plastic materials, but which is water soluble, has significant potential to reduce the volume of plastic waste requiring disposal as radwaste. Such a volume reduction will reduce overall plant )ampersand M costs, reduce the overall waste volume allocation utilization, and improve the regulatory perception of any plant realizing a volume reduction through plastic source minimization. This potential reduction in waste volume (and associated availability of the Low-level Waste Policy Amendments Act disposal allocation for other purposes), combined with potential economic benefits summarized above, has led to the undertaking of a detailed evaluation, presented in this paper

Electrostatics in Chemistry

Indian Academy of Sciences (India)

Home; Journals; Resonance – Journal of Science Education; Volume 4; Issue 7. Electrostatics in Chemistry - Molecular Electrostatic Potential: Visualization and Topography. Shridhar R Gadre Pravin K Bhadane. Series Article Volume 4 Issue 7 July 1999 pp 14-23 ...

Electroanalytical chemistry. Volume 14

International Nuclear Information System (INIS)

Bard, A.J.

1986-01-01

This volume is part of a series aimed at authoritative reviews of electroanalytical techniques and related areas of investigation. Volume 14 clearly maintains the high standards and proven usefulness of the series. Topics covered include conformation change and isomerization associated with electrode reactions, infrared vibrational spectroscopy of the electrode-solution interface, and precision in linear sweep and cyclic voltametry. A short history of electrochemical techniques which include the term square wave is provided

Consumer Exposure to Bisphenol A from Plastic Bottles

Science.gov (United States)

Bidabadi, Fatemeh

2013-01-01

Bisphenol A (BPA) is a plastic monomer and plasticizer and is a chemical that has one of the highest volume production worldwide, with more than six billion pounds each year. Its primary use is the production of polycarbonate plastics, epoxy resins used to line metal cans in a host of plastic consumer products such as toys, water pipes, drinking…

Electrostatics in Chemistry

Indian Academy of Sciences (India)

Home; Journals; Resonance – Journal of Science Education; Volume 4; Issue 2. Electrostatics in Chemistry - Basic Principles. Shridhar R Gadre Pravin K Bhadane. Series Article Volume 4 Issue 2 February 1999 pp 8-19. Fulltext. Click here to view fulltext PDF. Permanent link:

Industrial applications of radiation chemistry

International Nuclear Information System (INIS)

Puig, Jean Rene

1959-01-01

The status of industrial applications of radiation chemistry as it stands 6 months after the second Geneva international conference is described. The main features of the interaction of ionizing radiations with matter are briefly stated and a review is made of the best studied and the more promising systems of radiation chemistry. The fields of organics, plastics, heterogeneous catalysis are emphasized. Economies of radiation production and utilization are discussed. Reprint of a paper published in Industries atomiques - no. 5-6, 1959

Art and Plastic Surgery.

Science.gov (United States)

Fernandes, Julio Wilson; Metka, Susanne

2016-04-01

The roots of science and art of plastic surgery are very antique. Anatomy, drawing, painting, and sculpting have been very important to the surgery and medicine development over the centuries. Artistic skills besides shape, volume, and lines perception can be a practical aid to the plastic surgeons' daily work. An overview about the interactions between art and plastic surgery is presented, with a few applications to rhinoplasty, cleft lip, and other reconstructive plastic surgeries. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Americium behaviour in plastic vessels.

Science.gov (United States)

Legarda, F; Herranz, M; Idoeta, R; Abelairas, A

2010-01-01

The adsorption of (241)Am dissolved in water in different plastic storage vessels was determined. Three different plastics were investigated with natural and distilled waters and the retention of (241)Am by these plastics was studied. The same was done by varying vessel agitation time, vessel agitation speed, surface/volume ratio of water in the vessels and water pH. Adsorptions were measured to be between 0% and 70%. The adsorption of (241)Am is minimized with no water agitation, with PET or PVC plastics, and by water acidification. Copyright 2009 Elsevier Ltd. All rights reserved.

Presidential Green Chemistry Challenge: 2005 Small Business Award

Science.gov (United States)

Presidential Green Chemistry Challenge 2005 award winner, Metabolix, used biotechnology to develop microorganisms that produce polyhydroxyalkanoates: natural, biodegradable plastics with a range of environmental benefits.

DOE fundamentals handbook: Chemistry

International Nuclear Information System (INIS)

1993-01-01

This handbook was developed to assist nuclear facility operating contractors in providing operators, maintenance personnel, and the technical staff with the necessary fundamentals training to ensure a basic understanding of chemistry. This volume contains the following modules: reactor water chemistry (effects of radiation on water chemistry, chemistry parameters), principles of water treatment (purpose; treatment processes [ion exchange]; dissolved gases, suspended solids, and pH control; water purity), and hazards of chemicals and gases (corrosives [acids, alkalies], toxic compounds, compressed gases, flammable/combustible liquids)

Applications and societal benefits of plastics.

Science.gov (United States)

Andrady, Anthony L; Neal, Mike A

2009-07-27

This article explains the history, from 1600 BC to 2008, of materials that are today termed 'plastics'. It includes production volumes and current consumption patterns of five main commodity plastics: polypropylene, polyethylene, polyvinyl chloride, polystyrene and polyethylene terephthalate. The use of additives to modify the properties of these plastics and any associated safety, in use, issues for the resulting polymeric materials are described. A comparison is made with the thermal and barrier properties of other materials to demonstrate the versatility of plastics. Societal benefits for health, safety, energy saving and material conservation are described, and the particular advantages of plastics in society are outlined. Concerns relating to littering and trends in recycling of plastics are also described. Finally, we give predictions for some of the potential applications of plastic over the next 20 years.

Advances in quantum chemistry

CERN Document Server

Sabin, John R

2013-01-01

Advances in Quantum Chemistry presents surveys of current topics in this rapidly developing field that has emerged at the cross section of the historically established areas of mathematics, physics, chemistry, and biology. It features detailed reviews written by leading international researchers. This volume focuses on the theory of heavy ion physics in medicine.Advances in Quantum Chemistry presents surveys of current topics in this rapidly developing field that has emerged at the cross section of the historically established areas of mathematics, physics, chemistry, and biology. It features

Fundamentals of nuclear chemistry

International Nuclear Information System (INIS)

Matel, L.; Dulanska, S.

2013-01-01

This text-book is an introductory text in nuclear chemistry and radiochemistry, aimed on university undergraduate students in chemistry and related disciplines (physics, nuclear engineering). It covers the key aspects of modern nuclear chemistry. The text begins with basic theories in contemporary physics. It relates nuclear phenomena to key divisions of chemistry such as atomic structure, spectroscopy, equilibria and kinetics. It also gives an introduction to sources of ionizing radiation, detection of ionizing radiation, nuclear power industry and accident on nuclear installations as well as basic knowledge's of radiobiology. This book is essential reading for those taking a first course in nuclear chemistry and is a useful companion to other volumes in physical and analytical chemistry. It will also be of use to those new to working in nuclear chemistry or radiochemistry.

Recycling of plastic waste: Presence of phthalates in plastics from households and industry.

Science.gov (United States)

Pivnenko, K; Eriksen, M K; Martín-Fernández, J A; Eriksson, E; Astrup, T F

2016-08-01

Plastics recycling has the potential to substitute virgin plastics partially as a source of raw materials in plastic product manufacturing. Plastic as a material may contain a variety of chemicals, some potentially hazardous. Phthalates, for instance, are a group of chemicals produced in large volumes and are commonly used as plasticisers in plastics manufacturing. Potential impacts on human health require restricted use in selected applications and a need for the closer monitoring of potential sources of human exposure. Although the presence of phthalates in a variety of plastics has been recognised, the influence of plastic recycling on phthalate content has been hypothesised but not well documented. In the present work we analysed selected phthalates (DMP, DEP, DPP, DiBP, DBP, BBzP, DEHP, DCHP and DnOP) in samples of waste plastics as well as recycled and virgin plastics. DBP, DiBP and DEHP had the highest frequency of detection in the samples analysed, with 360μg/g, 460μg/g and 2700μg/g as the maximum measured concentrations, respectively. Among other, statistical analysis of the analytical results suggested that phthalates were potentially added in the later stages of plastic product manufacturing (labelling, gluing, etc.) and were not removed following recycling of household waste plastics. Furthermore, DEHP was identified as a potential indicator for phthalate contamination of plastics. Close monitoring of plastics intended for phthalates-sensitive applications is recommended if recycled plastics are to be used as raw material in production. Copyright © 2016 Elsevier Ltd. All rights reserved.

Presidential Green Chemistry Challenge: 2002 Greener Reaction Conditions Award

Science.gov (United States)

Presidential Green Chemistry Challenge 2002 award winner, Cargill Dow, developed the NatureWorks process to make biobased, compostable, and recyclable polylactic acid polymers for fibers and plastic packaging.

Analytical chemistry

International Nuclear Information System (INIS)

Choi, Jae Seong

1993-02-01

This book is comprised of nineteen chapters, which describes introduction of analytical chemistry, experimental error and statistics, chemistry equilibrium and solubility, gravimetric analysis with mechanism of precipitation, range and calculation of the result, volume analysis on general principle, sedimentation method on types and titration curve, acid base balance, acid base titration curve, complex and firing reaction, introduction of chemical electro analysis, acid-base titration curve, electrode and potentiometry, electrolysis and conductometry, voltammetry and polarographic spectrophotometry, atomic spectrometry, solvent extraction, chromatograph and experiments.

Analytical chemistry

Energy Technology Data Exchange (ETDEWEB)

Choi, Jae Seong

1993-02-15

This book is comprised of nineteen chapters, which describes introduction of analytical chemistry, experimental error and statistics, chemistry equilibrium and solubility, gravimetric analysis with mechanism of precipitation, range and calculation of the result, volume analysis on general principle, sedimentation method on types and titration curve, acid base balance, acid base titration curve, complex and firing reaction, introduction of chemical electro analysis, acid-base titration curve, electrode and potentiometry, electrolysis and conductometry, voltammetry and polarographic spectrophotometry, atomic spectrometry, solvent extraction, chromatograph and experiments.

Chemistry Today and Tomorrow-The Central, Useful, and Creative ...

Indian Academy of Sciences (India)

Home; Journals; Resonance – Journal of Science Education; Volume 2; Issue 5. Chemistry Today and Tomorrow – The Central, Useful and Creative Science. Uday Maitra. Book Review Volume 2 ... Author Affiliations. Uday Maitra1. Department of Organic Chemistry, Indian Institute of Science, Bangalore 560 012, India.

Nobel Prize in Chemistry-1997

Indian Academy of Sciences (India)

Home; Journals; Resonance – Journal of Science Education; Volume 3; Issue 2. Nobel Prize in Chemistry – 1997 The Story of Two Extra-ordinary Enzymes. Subramania Ranganathan. General Article Volume 3 Issue 2 February 1998 pp 45-52 ...

Chemistry with Inexpensive Materials: Spray Bottles and Plastic Bags.

Science.gov (United States)

Zoltewicz, Susan

1993-01-01

Presents eight chemistry activities that are interesting and involve simple, easily available materials. Topics include mystery writing, valentine hearts, flame tests, evaporation race, buoyancy versus mass, determination of relative masses of gases, mole sample container, and cold and hot packs. (DDR)

Plastic strain caused by contraction of pores in polycrystalline graphites

International Nuclear Information System (INIS)

Ioka, Ikuo; Yoda, Shinichi; Konishi, Takashi.

1989-01-01

The effects of porosity on mechanical properties and deformation behavior of four isotropic polycrystalline graphites were studied. The pore size distributions of the graphites were measured using a conventional mercury penetration technique. The average pore radius of ISO-88 graphite was about one-tenth of that of ISEM-1, IG-11 or IG-15 graphites. Young's modulus of the graphites decreased with increasing porosity. The stress-strain curve of each graphite was measured in its lateral and axial directions. Young's modulus of graphite decreased with increasing load. The plastic strain at a given compressive load was calculated from the stress-strain curve and the initial gradient of the unloading curve at the load. The ratio of lateral plastic strain to axial plastic strain for the graphites was less than 0.5, indicating that the volume of the graphites decreased during compressive loading. By assuming that the volume change was caused by contraction of pores, plastic strain associated with contraction of pores was calculated from the axial plastic strain and lateral plastic strain by slips along the basal planes. The plastic strain increased with increasing axial plastic strain and porosity of graphite. (author)

Presidential Green Chemistry Challenge: 2016 Designing Greener Chemicals and Specific Environmental Benefit: Climate Change Awards

Science.gov (United States)

Presidential Green Chemistry Challenge 2016 award winner, Newlight Technologies, developed a net carbon negative plastic made from methane-based GHG. It is cheaper than petroleum-based plastic; used to make cell phone cases, furniture, and other products.

Gas phase ion chemistry

CERN Document Server

Bowers, Michael T

1979-01-01

Gas Phase Ion Chemistry, Volume 1 covers papers on the advances of gas phase ion chemistry. The book discusses the advances in flow tubes and the measurement of ion-molecule rate coefficients and product distributions; the ion chemistry of the earth's atmosphere; and the classical ion-molecule collision theory. The text also describes statistical methods in reaction dynamics; the state selection by photoion-photoelectron coincidence; and the effects of temperature and pressure in the kinetics of ion-molecule reactions. The energy distribution in the unimolecular decomposition of ions, as well

A METHOD OF RAPID CULTIVATION OF RADISH SEED PLANTS IN PLASTIC POTS OF SMALL-VOLUME

Directory of Open Access Journals (Sweden)

V. A. Stepanov

2017-01-01

Full Text Available The development of cheap and rapid breeding methods to breed  the lines used for  hybrid  F1  production  is a very actual task. The study was carried out with a use of radish varieties originated at VNIISSOK and breeding lines obtained by crossing components of different origin with male  sterility  in  winter  glass  greenhouse.  The  mother plants were grown  on the trays Plantec 64, while seedplants were grown in plastic pots of 1 liter capacity. The some morphobiological features such as the small habitus of see-plant; smaller number of secondary branching and absence of following branches; and consequently, the low yield of seeds were revealed in seed-plants of radish being grown in plastic pots. The period of ontogenesis in radish at first winter-spring rotation with this cultivation approach was reduced to 92 days. At the second summer-autumn rotation with additional lighting the duration of period of ontogenesis was essentially shorter than in the first rotation.  The utilization of  small-volume capacities in winter glass greenhouse to grow the radish seed-plants has permitted to produce two generations a year.

Learning Organic Chemistry Through Natural Products

Indian Academy of Sciences (India)

Home; Journals; Resonance – Journal of Science Education; Volume 16; Issue 12. Learning Organic Chemistry Through Natural Products - Architectural Designs in Molecular Constructions. N R Krishnaswamy. Volume 16 Issue 12 December 2011 pp 1287-1293 ...

Commissioning of a continuous melt densification system for plastic waste. Contributed Paper PE-05

International Nuclear Information System (INIS)

Anji Reddy, D.; Chennakeshavalu, G.; Ramesh Babu, B.; Subba Rao, V.; Coelho, G.J.M.; Rao, S.V.S.; Paul, Biplob

2014-01-01

Volume reduction of radioactive solid wastes is carried out with an aim to maximize the utilization of disposal space. Cellulosic combustible solid wastes like cotton, paper etc. are treated by incineration and the plastic wastes are volume reduced by baling. Compaction of plastic wastes gives volume reduction factors in the range of 3 to 5. With a view to achieve higher volume reduction factors, a melt-densification process was developed indigenously at CWMF for reducing the volume of plastic wastes before disposal. Based on laboratory results, a pilot plant scale batch Melt Densification Unit was designed and operated. 120 M 3 of Category-I polythene waste was melted and the Volume Reduction Factors (VRF) obtained were up to 20. To meet the future needs and increasing the throughput, a continues-feed, PLC controlled, advanced Melt Densification System was commissioned recently. (author)

Modern plastic solar cells : materials, mechanisms and modeling

NARCIS (Netherlands)

Chiechi, Ryan C.; Havenith, Remco W.A.; Hummelen, Jan C.; Koster, L. Jan Anton; Loi, Maria A.

2013-01-01

We provide a short review of modern 'plastic' solar cells, a broad topic that spans materials science, physics, and chemistry. The aim of this review is to provide a primer for non-experts or researchers in related fields who are curious about this rapidly growing field of interdisciplinary

New plastic recycling technology

Science.gov (United States)

Greater than 60% of the total plastic content of municipal solid waste is comprised of polyolefins (high-density, low-density, and linear polyethylene and polypropylene. Polyethylene (PE) is the largest-volume component but presents a challenge due to the absence of low-energy de...

Learning Organic Chemistry Through Natural Products

Indian Academy of Sciences (India)

Home; Journals; Resonance – Journal of Science Education; Volume 1; Issue 2. Learning Organic Chemistry Through Natural Products Determination of Absolute Stereochemistry. N R Krishnaswamy. Series Article Volume 1 Issue 2 February 1996 pp 40-46 ...

Presidential Green Chemistry Challenge: 2012 Academic Award (Waymouth and Hedrick)

Science.gov (United States)

Presidential Green Chemistry Challenge 2012 award winners, Professor Robert M. Waymouth and Dr. James L. Hedrick, developed a broad class of highly active, environmentally benign, metal-free catalysts for synthesizing plastics.

Learning Organic Chemistry Through Natural Products

Indian Academy of Sciences (India)

Home; Journals; Resonance – Journal of Science Education; Volume 1; Issue 10. Learning Organic Chemistry Through Natural Products Architectural Designs in Molecular Constructions. N R Krishnaswamy. Series Article Volume 1 Issue 10 October 1996 pp 37-43 ...

Learning Organic Chemistry Through Natural Products

Indian Academy of Sciences (India)

Home; Journals; Resonance – Journal of Science Education; Volume 1; Issue 7. Learning Organic Chemistry Through Natural engine Products - Structure and Biological Functions. N R Krishnaswamy. Series Article Volume 1 Issue 7 July 1996 pp 23-30 ...

Fundamentals of the theory of plasticity

CERN Document Server

Kachanov, L M

2004-01-01

Intended for use by advanced engineering students and professionals, this volume focuses on plastic deformation of metals at normal temperatures, as applied to strength of machines and structures. 1971 edition.

Learning Organic Chemistry Through Natural Products

Indian Academy of Sciences (India)

Home; Journals; Resonance – Journal of Science Education; Volume 1; Issue 5. Learning Organic Chemistry Through Natural Products From Molecular and Electronic Structures to Reactivity. N R Krishnaswamy. Series Article Volume 1 Issue 5 May 1996 pp 12-18 ...

Advances in electron transfer chemistry

CERN Document Server

Mariano, Patrick S

1993-01-01

Advances in Electron Transfer Chemistry, Volume 3 presents studies that discuss findings in the various aspects of electron chemistry. The book is comprised of four chapters; each chapter reviews a work that tackles an issue in electron transfer chemistry. Chapter 1 discusses the photoinduced electron transfer in flexible biaryl donor-acceptor molecules. Chapter 2 tackles light-induced electron transfer in inorganic systems in homogeneous and heterogeneous phases. The book also covers internal geometry relaxation effects on electron transfer rates of amino-centered systems. The sequential elec

The radiation chemistry of macromolecules

CERN Document Server

1973-01-01

The Radiation Chemistry of Macromolecules, Volume II is a collection of papers that discusses radiation chemistry of specific systems. Part 1 deals with radiation chemistry of substituted vinyl polymers, particularly polypropylene (PP) as its structure is intermediate between polyethylene and polyisobutylene. This part also discusses polypropylene oxide (PPOx) for it can be prepared in the atactic, isotactic, and optically active forms. One paper focuses on the fundamental chemical processes and the changes in physical properties that give rise to many different applications of polystyrene. An

Fines Classification Based on Sensitivity to Pore-Fluid Chemistry

KAUST Repository

Jang, Junbong

2015-12-28

The 75-μm particle size is used to discriminate between fine and coarse grains. Further analysis of fine grains is typically based on the plasticity chart. Whereas pore-fluid-chemistry-dependent soil response is a salient and distinguishing characteristic of fine grains, pore-fluid chemistry is not addressed in current classification systems. Liquid limits obtained with electrically contrasting pore fluids (deionized water, 2-M NaCl brine, and kerosene) are combined to define the soil "electrical sensitivity." Liquid limit and electrical sensitivity can be effectively used to classify fine grains according to their fluid-soil response into no-, low-, intermediate-, or high-plasticity fine grains of low, intermediate, or high electrical sensitivity. The proposed methodology benefits from the accumulated experience with liquid limit in the field and addresses the needs of a broader range of geotechnical engineering problems. © ASCE.

Fines classification based on sensitivity to pore-fluid chemistry

Science.gov (United States)

Jang, Junbong; Santamarina, J. Carlos

2016-01-01

The 75-μm particle size is used to discriminate between fine and coarse grains. Further analysis of fine grains is typically based on the plasticity chart. Whereas pore-fluid-chemistry-dependent soil response is a salient and distinguishing characteristic of fine grains, pore-fluid chemistry is not addressed in current classification systems. Liquid limits obtained with electrically contrasting pore fluids (deionized water, 2-M NaCl brine, and kerosene) are combined to define the soil “electrical sensitivity.” Liquid limit and electrical sensitivity can be effectively used to classify fine grains according to their fluid-soil response into no-, low-, intermediate-, or high-plasticity fine grains of low, intermediate, or high electrical sensitivity. The proposed methodology benefits from the accumulated experience with liquid limit in the field and addresses the needs of a broader range of geotechnical engineering problems.

The elasto plastic fracture mechanics in ductile metal sheets

International Nuclear Information System (INIS)

Khan, M.A.; Malik, M.N.; Naeem, A.; Haq, A.U.; Atkins, A.G.

1999-01-01

The crack initiation of propagation in ductile metal sheets are caused by various micro and macro changes taking place due to material properties, applied loads, shape of the indenter (tool geometry) and the environmental conditions. These microstructural failures are directly related to the atomic bonding, crystal lattices, grain boundary status, material flaws in matrix, inhomogeneities and anisotropy in the metal sheets. The Elasto-Plastic related energy based equations are applied to these Rigid Plastic materials to determine the onset of fracture in metal forming. The combined stress and strain criterion of a critical plastic work per unit volume is no more considered as a universal ductile fracture criterion, rather a critical plastic work per unit volume dependence on all sort of stresses (hydrostatic) are the required features for the sheet metal failure (fracture). In this present study, crack initiation and propagation are related empirically with fracture toughness and the application of the theory in industry to save energy. (author)

Fines Classification Based on Sensitivity to Pore-Fluid Chemistry

KAUST Repository

Jang, Junbong; Santamarina, Carlos

2015-01-01

The 75-μm particle size is used to discriminate between fine and coarse grains. Further analysis of fine grains is typically based on the plasticity chart. Whereas pore-fluid-chemistry-dependent soil response is a salient and distinguishing

Applications of supramolecular chemistry

CERN Document Server

Schneider, Hans-Jörg

2012-01-01

""The time is ripe for the present volume, which gathers thorough presentations of the numerous actually realized or potentially accessible applications of supramolecular chemistry by a number of the leading figures in the field. The variety of topics covered is witness to the diversity of the approaches and the areas of implementation…a broad and timely panorama of the field assembling an eminent roster of contributors.""-Jean-Marie Lehn, 1987 Noble Prize Winner in Chemistry

Physical chemistry and the environment

International Nuclear Information System (INIS)

Dunning, T.H. Jr.; Garrett, B.C.; Kolb, C.E. Jr.; Shaw, R.W.; Choppin, G.R.; Wagner, A.F.

1994-08-01

From the ozone hole and the greenhouse effect to plastics recycling and hazardous waste disposal, society faces a number of issues, the solutions to which require an unprecedented understanding of the properties of molecules. We are coming to realize that the environment is a coupled set of chemical systems, its dynamics determining the welfare of the biosphere and of humans in particular. These chemical systems are governed by fundamental molecular interactions, and they present chemists with an unparalleled challenge. The application of current concepts of molecular behavior and of up-to-date experimental and computational techniques can provide us with insights into the environment that are needed to mitigate past damage, to anticipate the impact of current human activity, and to avoid future insults to the environment. Environmental chemistry encompasses a number of separate, yet interlocking, areas of research. In all of these areas progress is limited by an inadequate understanding of the underlying chemical processes involved. Participation of all chemical approaches -- experimental, theoretical and computational -- and of all disciplines of chemistry -- organic, inorganic, physical, analytical and biochemistry -- will be required to provide the necessary fundamental understanding. The Symposium on ''Physical Chemistry and the Environment'' was designed to bring the many exciting and challenging physical chemistry problems involved in environmental chemistry to the attention of a larger segment of the physical chemistry community

Spins in chemistry

CERN Document Server

McWeeny, Roy

2004-01-01

Originally delivered as a series of lectures, this volume systematically traces the evolution of the ""spin"" concept from its role in quantum mechanics to its assimilation into the field of chemistry. Author Roy McWeeny presents an in-depth illustration of the deductive methods of quantum theory and their application to spins in chemistry, following the path from the earliest concepts to the sophisticated physical methods employed in the investigation of molecular structure and properties. Starting with the origin and development of the spin concept, the text advances to an examination of sp

Modeling plasticity by non-continuous deformation

Science.gov (United States)

Ben-Shmuel, Yaron; Altus, Eli

2017-10-01

Plasticity and failure theories are still subjects of intense research. Engineering constitutive models on the macroscale which are based on micro characteristics are very much in need. This study is motivated by the observation that continuum assumptions in plasticity in which neighbour material elements are inseparable at all-time are physically impossible, since local detachments, slips and neighbour switching must operate, i.e. non-continuous deformation. Material microstructure is modelled herein by a set of point elements (particles) interacting with their neighbours. Each particle can detach from and/or attach with its neighbours during deformation. Simulations on two- dimensional configurations subjected to uniaxial compression cycle are conducted. Stochastic heterogeneity is controlled by a single "disorder" parameter. It was found that (a) macro response resembles typical elasto-plastic behaviour; (b) plastic energy is proportional to the number of detachments; (c) residual plastic strain is proportional to the number of attachments, and (d) volume is preserved, which is consistent with macro plastic deformation. Rigid body displacements of local groups of elements are also observed. Higher disorder decreases the macro elastic moduli and increases plastic energy. Evolution of anisotropic effects is obtained with no additional parameters.

Physico-chemical modifications of plastics by ionization

International Nuclear Information System (INIS)

Rouif, S.

2002-01-01

The industrial use of ionizing radiations (beta and gamma), initially for the sterilization of medico-surgical instruments and for the preservation of food products, has led to the development of the chemistry of polymers under radiations. Ionizing radiations can initiate chemical reactions (chain cutting, poly-additions, polymerization etc..) thanks to the formation of free radicals. The main applications concerns the degradation of plastics, the reticulation of plastics and of woods impregnated with resin, and the grafting of polymers. The processing of plastic materials was initially performed with low energy electron accelerators (0.1 to 3 MeV), allowing only surface treatments, while recent high energy accelerators (10 MeV) and gamma facilities allow the treatment in depth of materials (from few cm to 1 m). This article describes the industrial treatments performed with such high energy facilities: 1 - action of ionizing radiations on plastic materials: different types of ionizing radiations, action of beta and gamma radiations, chemical changes induced by beta and gamma radiations; 2 - reticulation of plastic materials submitted to beta and gamma radiations: radio-'reticulable' polymers and reticulation co-agents, modification of the properties of reticulated plastic materials under beta and gamma radiations; 3 - industrial aspects of reticulation under beta and gamma radiation: industrial irradiation facilities, dosimetry and radio-reticulation control, applications; 4 - conclusion. (J.S.)

An Appreciation of Free Radical Chemistry

Indian Academy of Sciences (India)

... Lecture Workshops · Refresher Courses · Symposia · Live Streaming. Home; Journals; Resonance – Journal of Science Education; Volume 10; Issue 9. An Appreciation of Free Radical Chemistry - 6. Experiments Involving Free Radicals. G Nagendrappa. Classroom Volume 10 Issue 9 September 2005 pp 79-84 ...

New trends in analytical chemistry. Volume 2

International Nuclear Information System (INIS)

Zyka, J.

1984-01-01

The book consists of 8 chapters and describes modern methods of analytical chemistry. The chapters Moessbauer spectroscopy, Neutron activation analysis, and Analytical uses of particle-induced characteristic X radiation (PIXE) describe the principles of these methods, the used experimental equip=-ment, methods of evaluation, modification of methods and examples of practical uses. (M.D.)

Chemistry of high temperature superconductors

CERN Document Server

1991-01-01

This review volume contains the most up-to-date articles on the chemical aspects of high temperature oxide superconductors. These articles are written by some of the leading scientists in the field and includes a comprehensive list of references. This is an essential volume for researchers working in the fields of ceramics, materials science and chemistry.

Activation volume of martensitic ODS steel

Energy Technology Data Exchange (ETDEWEB)

Kim, D. W.; Noh, S.; Kim, T. K. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2016-10-15

Apparent activation volume as a function of temperature is 86b{sup 3}-42b{sup 3}. Activation volume decreases with increasing temperature. Activation volume changes scarcely with decreasing strain rate. Strain rate sensitivity increases with increasing temperature and decreasing strain rate. Nano-sized oxide dispersion strengthened (ODS) martensitic steel has a high strength, low thermal expansion coefficient, high thermal conductivity, and a good swelling resistance. Martensitic ODS steel is a candidate material for fuel cladding of sodium cooled fast breeder reactor (SFR). The plastic flow stress is determined through the interaction of dislocations with the obstacles encountered inside lattice. Dislocation movement through the lattice or past an obstacle requires surmounting of the energy barrier by a combination of applied stress and thermal activation. The plastic deformation of materials is a thermally activated process dependent upon time, temperature, and strain rate. Characterization of the rate controlling mechanism for plastic deformation due to dislocation motion in crystalline materials is done by the assessment of activation volume based on thermal activation analysis.

Analytical spectroscopy. Analytical Chemistry Symposia Series, Volume 19

International Nuclear Information System (INIS)

Lyon, W.S.

1984-01-01

This book contains papers covering several fields in analytical chemistry including lasers, mass spectrometry, inductively coupled plasma, activation analysis and emission spectroscopy. Separate abstracting and indexing was done for 64 papers in this book

Symposium on high temperature and materials chemistry

International Nuclear Information System (INIS)

1989-10-01

This volume contains the written proceedings of the Symposium on High Temperature and Materials Chemistry held in Berkeley, California on October 24--25, 1989. The Symposium was sponsored by the Materials and Chemical Sciences Division of Lawrence Berkeley Laboratory and by the College of Chemistry of the University of California at Berkeley to discuss directions, trends, and accomplishments in the field of high temperature and materials chemistry. Its purpose was to provide a snapshot of high temperature and materials chemistry and, in so doing, to define status and directions

Symposium on high temperature and materials chemistry

Energy Technology Data Exchange (ETDEWEB)

1989-10-01

This volume contains the written proceedings of the Symposium on High Temperature and Materials Chemistry held in Berkeley, California on October 24--25, 1989. The Symposium was sponsored by the Materials and Chemical Sciences Division of Lawrence Berkeley Laboratory and by the College of Chemistry of the University of California at Berkeley to discuss directions, trends, and accomplishments in the field of high temperature and materials chemistry. Its purpose was to provide a snapshot of high temperature and materials chemistry and, in so doing, to define status and directions.

Gas phase ion chemistry

CERN Document Server

Bowers, Michael T

1979-01-01

Gas Phase Ion Chemistry, Volume 2 covers the advances in gas phase ion chemistry. The book discusses the stabilities of positive ions from equilibrium gas-phase basicity measurements; the experimental methods used to determine molecular electron affinities, specifically photoelectron spectroscopy, photodetachment spectroscopy, charge transfer, and collisional ionization; and the gas-phase acidity scale. The text also describes the basis of the technique of chemical ionization mass spectrometry; the energetics and mechanisms of unimolecular reactions of positive ions; and the photodissociation

Valorization of post-consumer waste plastic in cementitious concrete composites

International Nuclear Information System (INIS)

Marzouk, O. Yazoghli; Dheilly, R.M.; Queneudec, M.

2007-01-01

The sheer amount of disposable bottles being produced nowadays makes it imperative to identify alternative procedures for recycling them since they are non-biodegradable. This paper describes an innovative use of consumed plastic bottle waste as sand-substitution aggregate within composite materials for building application. Particularly, bottles made of polyethylene terephthalate (PET) have been used as partial and complete substitutes for sand in concrete composites. Various volume fractions of sand varying from 2% to 100% were substituted by the same volume of granulated plastic, and various sizes of PET aggregates were used. The bulk density and mechanical characteristics of the composites produced were evaluated. To study the relationship between mechanical properties and composite microstructure, scanning electron microscopy technique was employed. The results presented show that substituting sand at a level below 50% by volume with granulated PET, whose upper granular limit equals 5 mm, affects neither the compressive strength nor the flexural strength of composites. This study demonstrates that plastic bottles shredded into small PET particles may be used successfully as sand-substitution aggregates in cementitious concrete composites. These new composites would appear to offer an attractive low-cost material with consistent properties; moreover, they would help in resolving some of the solid waste problems created by plastics production and in saving energy

20th intersociety energy conversion engineering conference. Volume 2

International Nuclear Information System (INIS)

Anon.

1985-01-01

This volume contains information on the mission and status of the DOE's battery energy storage program, the development of an advanced battery electric energy storage system for electric utility load leveling, and the aluminum-air power cell. Plastic-bonded, nonsintered nickel-cadmium batteries for submarines and the cycle life chemistry of ambient-temperature secondary lithium cells are also discussed. The development of zinc-bromine batteries for stationary energy storage, the development of a zinc-chloride battery for 10-kw electric energy storage, and sodium sulfur cells with high conductivity glass electrolytes are discussed. The recovery of lead/acid batteries from abusive deep discharge, and high rate lithium batteries safety testing for U.L. component recognition are reviewed. Enhanced energy recovery, geothermal power, and heat engine cycles are discussed. Hydrogen energy, magnetohydrodynamics and nuclear fission are examined

The chemistry of silicon

CERN Document Server

Rochow, E G; Emeléus, H J; Nyholm, Ronald

1975-01-01

Pergamon Texts in Organic Chemistry, Volume 9: The Chemistry of Silicon presents information essential in understanding the chemical properties of silicon. The book first covers the fundamental aspects of silicon, such as its nuclear, physical, and chemical properties. The text also details the history of silicon, its occurrence and distribution, and applications. Next, the selection enumerates the compounds and complexes of silicon, along with organosilicon compounds. The text will be of great interest to chemists and chemical engineers. Other researchers working on research study involving s

Use of macroporous plastics in extraction chromatography

International Nuclear Information System (INIS)

Braun, T.; Farac, A.B.

1978-01-01

Possibilities are analysed which the use of porous plastics (polyvinyl chloride, siloxane rubber, polyurethane, polystyrene and etc.) as carriers presents in extraction chromatography. Short characteristics of chemical and physical properties of macroporous carriers is given. The importance of correct chromatographic column packing is noted to obtain columns with good hydrodynamic characteristics and operational properties. Examples of using columns with macroporous carriers in radiochemistry and inorganic chemistry for element separation are given

Advances in high temperature chemistry 1

CERN Document Server

Eyring, Leroy

2013-01-01

Advances in High Temperature Chemistry, Volume 1 describes the complexities and special and changing characteristics of high temperature chemistry. After providing a brief definition of high temperature chemistry, this nine-chapter book goes on describing the experiments and calculations of diatomic transition metal molecules, as well as the advances in applied wave mechanics that may contribute to an understanding of the bonding, structure, and spectra of the molecules of high temperature interest. The next chapter provides a summary of gaseous ternary compounds of the alkali metals used in

Plasticity size effects in voided crystals

DEFF Research Database (Denmark)

Hussein, M. I.; Borg, Ulrik; Niordson, Christian Frithiof

singularities in an elastic material. The lattice resistance to dislocation motion, dislocation nucleation, dislocation interaction with obstacles and annihilation are incorporated through a set of constitutive rules. Over the range of length scales investigated, both the discrete dislocation and strain......The shear and equi-biaxial straining responses of periodic voided single crystals are analysed using discrete dislocation plasticity and a continuum strain gradient crystal plasticity theory. In the discrete dislocation formulation the dislocations are all of edge character and are modelled as line...... predictions of the two formulations for all crystal types and void volume fractions considered when the material length scale in the non-local plasticity model chosen to be $0.325\\mu m$ (around ten times the slip plane spacing in the discrete dislocation models)....

Plasticity size effects in voided crystals

DEFF Research Database (Denmark)

Hussein, M.I.; Borg, Ulrik; Niordson, Christian Frithiof

2008-01-01

as line singularities in an elastic material. The lattice resistance to dislocation motion, dislocation nucleation, dislocation interaction with obstacles and annihilation are incorporated through a set of constitutive rules. Over the range of length scales investigated, both the discrete dislocation......The shear and equi-biaxial straining responses of periodic voided single crystals are analysed using discrete dislocation plasticity and a continuum strain gradient crystal plasticity theory. In the discrete dislocation formulation, the dislocations are all of edge character and are modelled...... between predictions of the two formulations for all crystal types and void volume fractions considered when the material length scale in the non-local plasticity model is chosen to be 0.325 mu m (about 10 times the slip plane spacing in the discrete dislocation models)....

Extended Excluded Volume: Its Origin and Consequences

Czech Academy of Sciences Publication Activity Database

Nezbeda, Ivo; Rouha, M.

2013-01-01

Roč. 85, č. 1 (2013), s. 201-210 ISSN 0033-4545. [International Conference on Solution Chemistry (ICSC-32) /32./. La Grande Motte, 28.08.2011-02.09.2011] R&D Projects: GA AV ČR IAA400720802 Institutional support: RVO:67985858 Keywords : excluded volume * partial molar volume * primitive models Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.112, year: 2013

Correlation between crystallization behaviour and interfacial interactions in plasticized PLA/POSS nanocomposites

Energy Technology Data Exchange (ETDEWEB)

Kodal, Mehmet, E-mail: mehmet.kodal@kocaeli.edu.tr; Şirin, Hümeyra; Özkoç, Güralp, E-mail: guralp.ozkoc@kocaeli.edu.tr [Department of Chemical Engineering, Kocaeli University, 41380, Kocaeli Turkey (Turkey)

2016-03-09

In this study, the correlation between crystallization behavior and surface chemistry of polyhedral oligomeric silsesquioxanes (POSS) for plasticized poly(lactic acid) (PLA)/POSS nanocomposites was investigated. Four different kinds of POSS particles having different chemical structures were used. Poly(ethylene glycol) (PEG, 8000 g/mol) was utilized as the plasticiser. The nanocomposites were melt-compounded in an Xplore Instruments 15 cc twin screw microcompounder at 180°C barrel temperature and 100 rpm screw speed. Non-isothermal crystallization behaviour of PLA/PEG/POSS nanocomposites were evaluated from common kinetic models such as Avrami and Avrami-Ozawa and Kissinger by using the thermal data obtained from differantial scanning calorimetry (DSC). A polarized optical microscope (POM) equipped with a hot-stage was used to examine the morphology during the crystal growth. In order to investigate the interfacial interactions between POSS particles and plasticized PLA, thermodynamic work of adhesion approach was adopted using the experimentally determined surface energies. A strong correlation was obtained between interfacial chemistry and the nucleation rate in plasticized PLA/POSS nanocomposites. It was found that the polar interactions were the dominating factor which determines the nucleation activity of the POSS particles.

Correlation between crystallization behaviour and interfacial interactions in plasticized PLA/POSS nanocomposites

International Nuclear Information System (INIS)

Kodal, Mehmet; Şirin, Hümeyra; Özkoç, Güralp

2016-01-01

In this study, the correlation between crystallization behavior and surface chemistry of polyhedral oligomeric silsesquioxanes (POSS) for plasticized poly(lactic acid) (PLA)/POSS nanocomposites was investigated. Four different kinds of POSS particles having different chemical structures were used. Poly(ethylene glycol) (PEG, 8000 g/mol) was utilized as the plasticiser. The nanocomposites were melt-compounded in an Xplore Instruments 15 cc twin screw microcompounder at 180°C barrel temperature and 100 rpm screw speed. Non-isothermal crystallization behaviour of PLA/PEG/POSS nanocomposites were evaluated from common kinetic models such as Avrami and Avrami-Ozawa and Kissinger by using the thermal data obtained from differantial scanning calorimetry (DSC). A polarized optical microscope (POM) equipped with a hot-stage was used to examine the morphology during the crystal growth. In order to investigate the interfacial interactions between POSS particles and plasticized PLA, thermodynamic work of adhesion approach was adopted using the experimentally determined surface energies. A strong correlation was obtained between interfacial chemistry and the nucleation rate in plasticized PLA/POSS nanocomposites. It was found that the polar interactions were the dominating factor which determines the nucleation activity of the POSS particles.

Computational chemistry reviews of current trends v.4

CERN Document Server

1999-01-01

This volume presents a balanced blend of methodological and applied contributions. It supplements well the first three volumes of the series, revealing results of current research in computational chemistry. It also reviews the topographical features of several molecular scalar fields. A brief discussion of topographical concepts is followed by examples of their application to several branches of chemistry.The size of a basis set applied in a calculation determines the amount of computer resources necessary for a particular task. The details of a common strategy - the ab initio model potential

Technetium Chemistry in HLW

International Nuclear Information System (INIS)

Hess, Nancy J.; Felmy, Andrew R.; Rosso, Kevin M.; Xia Yuanxian

2005-01-01

Tc contamination is found within the DOE complex at those sites whose mission involved extraction of plutonium from irradiated uranium fuel or isotopic enrichment of uranium. At the Hanford Site, chemical separations and extraction processes generated large amounts of high level and transuranic wastes that are currently stored in underground tanks. The waste from these extraction processes is currently stored in underground High Level Waste (HLW) tanks. However, the chemistry of the HLW in any given tank is greatly complicated by repeated efforts to reduce volume and recover isotopes. These processes ultimately resulted in mixing of waste streams from different processes. As a result, the chemistry and the fate of Tc in HLW tanks are not well understood. This lack of understanding has been made evident in the failed efforts to leach Tc from sludge and to remove Tc from supernatants prior to immobilization. Although recent interest in Tc chemistry has shifted from pretreatment chemistry to waste residuals, both needs are served by a fundamental understanding of Tc chemistry

Progress in physical chemistry

CERN Document Server

Hempelmann, Rolf

2008-01-01

Progress in Physical Chemistry is a collection of recent ""Review Articles"" published in the ""Zeitschrift für Physikalische Chemie"". The second volume of Progress in Physical Chemistry is a collection of thematically closely related minireview articles written by the members of the Collaborative Research Centre (SFB) 277 of the German Research Foundation (DFG). These articles are based on twelve years of intense coordinated research efforts. Central topics are the synthesis and the characterization of interface-dominated, i.e. nanostructured materials, mainly in the solid state but also as

Chemistry. Focus on Excellence, Volume 3, Number 2.

Science.gov (United States)

Penick, John E., Ed.; Krajcik, Joseph, Ed.

Eight examples of innovative and outstanding chemistry programs are described. These programs were selected using state criteria and at least four independent reviewers. While Project Synthesis offered a desired state, these examples of excellence provided views of what is already a reality. Included are the goals of an exemplary science program…

a study of the physico-chemistry and mineralogy of agbaja clay for ...

African Journals Online (AJOL)

MBI

characterized for particle size distribution, plasticity index, chemical ... m = mass of sample after ignition (g). pH determination. .... the clay must have been of a secondary origin formed from .... The Chemistry and Physics of. Clay and Allied ...

Radiation chemistry and its applications

International Nuclear Information System (INIS)

1968-01-01

In recent years considerable progress has been made in understanding the fundamental chemical reactions that occur when materials are irradiated. This has followed from the development of new techniques for studying these reactions. The International Atomic Energy Agency held a Panel on Radiation Chemistry in Vienna on 17-21 April 1967, to review the current status of various sources, new techniques in radiation chemistry, and their applications. The main sources mentioned by the Panel were isotope sources, electron accelerators, and chemonuclear reactors. Among the basic techniques discussed were pulsed radiolysis, flash photolysis, fast ESR methods, irradiation at liquid helium temperatures, electric discharge methods and far ultra-violet methods. Interesting industrial applications were discussed, such as the development of wood-plastic combinations, and a paper was given on the curing of paints and thin films Refs, figs and tabs

Physico-chemical properties of excavated plastic from landfill mining and current recycling routes

OpenAIRE

Canopoli, Luisa; Fidalgo, Beatriz; Coulon, Frederic; Wagland, Stuart T.

2018-01-01

In Europe over 5.25 billion tonnes of waste has been landfilled between 1995 and 2015. Among this large amount of waste, plastic represents typically 5–25 wt% which is significant and has the potential to be recycled and reintroduced into the circular economy. To date there is still however little information available of the opportunities and challenges in recovering plastics from landfill sites. In this review, the impacts of landfill chemistry on the degradation and/or contamination of exc...

NREL Senior Research Fellow Honored by The Journal of Physical Chemistry |

Science.gov (United States)

News | NREL 7 » NREL Senior Research Fellow Honored by The Journal of Physical Chemistry News Release: NREL Senior Research Fellow Honored by The Journal of Physical Chemistry January 10, 2007 The Journal of Physical Chemistry B. The Dec. 21 issue was titled The Arthur J. Nozik Festschrift (Volume 110

Learning Organic Chemistry Through Natural Products A Practical ...

Indian Academy of Sciences (India)

Home; Journals; Resonance – Journal of Science Education; Volume 1; Issue 9. Learning Organic Chemistry Through Natural Products A Practical Approach. N R Krishnaswamy. Series Article Volume 1 Issue 9 September 1996 pp 25-33. Fulltext. Click here to view fulltext PDF. Permanent link:

Variable Operative Experience in Hand Surgery for Plastic Surgery Residents.

Science.gov (United States)

Silvestre, Jason; Lin, Ines C; Levin, Lawrence Scott; Chang, Benjamin

Efforts to standardize hand surgery training during plastic surgery residency remain challenging. We analyze the variability of operative hand experience at U.S. plastic surgery residency programs. Operative case logs of chief residents in accredited U.S. plastic surgery residency programs were analyzed (2011-2015). Trends in fold differences of hand surgery case volume between the 10th and 90th percentiles of residents were assessed graphically. Percentile data were used to calculate the number of residents achieving case minimums in hand surgery for 2015. Case logs from 818 plastic surgery residents were analyzed of which a minority were from integrated (35.7%) versus independent/combined (64.3%) residents. Trend analysis of fold differences in case volume demonstrated decreasing variability among procedure categories over time. By 2015, fold differences for hand reconstruction, tendon cases, nerve cases, arthroplasty/arthrodesis, amputation, arterial repair, Dupuytren release, and neoplasm cases were below 10-fold. Congenital deformity cases among independent/combined residents was the sole category that exceeded 10-fold by 2015. Percentile data suggested that approximately 10% of independent/combined residents did not meet case minimums for arterial repair and congenital deformity in 2015. Variable operative experience during plastic surgery residency may limit adequate exposure to hand surgery for certain residents. Future studies should establish empiric case minimums for plastic surgery residents to ensure hand surgery competency upon graduation. Copyright © 2017 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

Transformation plasticity and hot pressing

International Nuclear Information System (INIS)

Chaklader, A.C.D.

1975-01-01

The transformation plasticity during the phase transition of quartz to cristobalite, monoclinic reversible tetragonal of zirconia, metakaolin to a spinel phase, and brucite to periclase was investigated by studying their compaction characteristics. Viscous flow was found to be the predominant mechanism of mass transport (after an initial particle rearrangement stage) in the case of quartz to cristobalite phase change where the transformation was associated with the formation of an intermediate amorphous silica phase. The results on the monoclinic reversible tetragonal transformation of zirconia indicated that it is most likely controlled by internal strain induced by the stress associated with the volume change (ΔV/V) and the flow stress of the weaker phase. Particle movement and deformation of the weaker phase (possibly tetragonal) may be the manifestation of this plasticity. The plasticity in the case of metakaolin to a spinel phase appeared to start before the exothermic reaction (generally encountered in a dta plot) and may be diffusion controlled. The plasticity encountered during brucite to periclase transformation may be the combined effect of disintegration of precursor particles, vapor-phase lubrication and some deformability of freshly formed very fine MgO particles

Theoretical chemistry advances and perspectives

CERN Document Server

Eyring, Henry

1980-01-01

Theoretical Chemistry: Advances and Perspectives, Volume 5 covers articles concerning all aspects of theoretical chemistry. The book discusses the mean spherical approximation for simple electrolyte solutions; the representation of lattice sums as Mellin-transformed products of theta functions; and the evaluation of two-dimensional lattice sums by number theoretic means. The text also describes an application of contour integration; a lattice model of quantum fluid; as well as the computational aspects of chemical equilibrium in complex systems. Chemists and physicists will find the book usef

Plastic Strain Induced Damage Evolution and Martensitic Transformation in Ductile Materials at Cryogenic Temperatures

CERN Document Server

Garion, C

2002-01-01

The Fe-Cr-Ni stainless steels are well known for their ductile behaviour at cryogenic temperatures. This implies development and evolution of plastic strain fields in the stainless steel components subjected to thermo-mechanical loads at low temperatures. The evolution of plastic strain fields is usually associated with two phenomena: ductile damage and strain induced martensitic transformation. Ductile damage is described by the kinetic law of damage evolution. Here, the assumption of isotropic distribution of damage (microcracks and microvoids) in the Representative Volume Element (RVE) is made. Formation of the plastic strain induced martensite (irreversible process) leads to the presence of quasi-rigid inclusions of martensite in the austenitic matrix. The amount of martensite platelets in the RVE depends on the intensity of the plastic strain fields and on the temperature. The evolution of the volume fraction of martensite is governed by a kinetic law based on the accumulated plastic strain. Both of thes...

Airborne chemistry: acoustic levitation in chemical analysis.

Science.gov (United States)

Santesson, Sabina; Nilsson, Staffan

2004-04-01

This review with 60 references describes a unique path to miniaturisation, that is, the use of acoustic levitation in analytical and bioanalytical chemistry applications. Levitation of small volumes of sample by means of a levitation technique can be used as a way to avoid solid walls around the sample, thus circumventing the main problem of miniaturisation, the unfavourable surface-to-volume ratio. Different techniques for sample levitation have been developed and improved. Of the levitation techniques described, acoustic or ultrasonic levitation fulfils all requirements for analytical chemistry applications. This technique has previously been used to study properties of molten materials and the equilibrium shape()and stability of liquid drops. Temperature and mass transfer in levitated drops have also been described, as have crystallisation and microgravity applications. The airborne analytical system described here is equipped with different and exchangeable remote detection systems. The levitated drops are normally in the 100 nL-2 microL volume range and additions to the levitated drop can be made in the pL-volume range. The use of levitated drops in analytical and bioanalytical chemistry offers several benefits. Several remote detection systems are compatible with acoustic levitation, including fluorescence imaging detection, right angle light scattering, Raman spectroscopy, and X-ray diffraction. Applications include liquid/liquid extractions, solvent exchange, analyte enrichment, single-cell analysis, cell-cell communication studies, precipitation screening of proteins to establish nucleation conditions, and crystallisation of proteins and pharmaceuticals.

Pyrolysis of plastic packaging waste: A comparison of plastic residuals from material recovery facilities with simulated plastic waste

International Nuclear Information System (INIS)

Adrados, A.; Marco, I. de; Caballero, B.M.; López, A.; Laresgoiti, M.F.; Torres, A.

2012-01-01

Highlights: ► Pyrolysis of plastic waste. ► Comparison of different samples: real waste, simulated and real waste + catalyst. ► Study of the effects of inorganic components in the pyrolysis products. - Abstract: Pyrolysis may be an alternative for the reclamation of rejected streams of waste from sorting plants where packing and packaging plastic waste is separated and classified. These rejected streams consist of many different materials (e.g., polyethylene (PE), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), polyethylene terephthalate (PET), acrylonitrile butadiene styrene (ABS), aluminum, tetra-brik, and film) for which an attempt at complete separation is not technically possible or economically viable, and they are typically sent to landfills or incinerators. For this study, a simulated plastic mixture and a real waste sample from a sorting plant were pyrolyzed using a non-stirred semi-batch reactor. Red mud, a byproduct of the aluminum industry, was used as a catalyst. Despite the fact that the samples had a similar volume of material, there were noteworthy differences in the pyrolysis yields. The real waste sample resulted, after pyrolysis, in higher gas and solid yields and consequently produced less liquid. There were also significant differences noted in the compositions of the compared pyrolysis products.

Teaching Chemistry Students How To Use Patent Databases and Glean Patent Information

Science.gov (United States)

MacMillan, Margy; Shaw, Lawton

2008-07-01

Patent literature is an important source of chemical information that is often neglected by chemical educators. This paper describes an effort to teach chemistry students how to use patent databases to search for information on applied chemical technology related to the manufacture of industrial and specialty chemicals. Students in a second-year-level organic chemistry class were shown how to search patent literature as part of a group research paper assignment that involved determining the feasibility of starting an industrial chemical operation to manufacture a given industrial chemical. Students who were assigned high value or specialty chemicals were most likely to cite patent literature in their final papers. Students who were assigned plastics or bulk commodity chemicals were less likely to cite patents. It is suggested that students made choices about the usefulness of patent literature and that patents were most useful when current patents existed and provided the patent owner a competitive advantage. For plastics or commodity chemicals, manufacturing technologies tend to be mature and are well described by more accessible information sources. Suggestions are made for effective introduction of patent literature instruction into upper-level chemistry courses.

Use of autologous and microsurgical breast reconstruction by U.S. plastic surgeons.

Science.gov (United States)

Kulkarni, Anita R; Sears, Erika Davis; Atisha, Dunya M; Alderman, Amy K

2013-09-01

Concern exists that plastic surgeons are performing fewer autologous and microsurgical breast reconstructions, despite superior long-term outcomes. The authors describe the proportion of U.S. plastic surgeons performing these procedures and evaluate motivating factors and perceived barriers. A random national sample of American Society of Plastic Surgeons members was surveyed (n = 325; response rate, 76 percent). Surgeon and practice characteristics were assessed, and two multiple logistic regression models were created to evaluate factors associated with (1) high-volume autologous providers and (2) microsurgical providers. Qualitative assessments of motivating factors and barriers to microsurgery were also performed. Fewer than one-fifth of plastic surgeons perform autologous procedures for more than 50 percent of their breast cancer patients, and only one-quarter perform any microsurgical breast reconstruction. Independent predictors of a high-volume autologous practice include involvement with resident education (odds ratio, 2.57; 95 percent CI, 1.26 to 5.24) and a microsurgical fellowship (odds ratio, 2.09; 95 percent CI, 1.04 to 4.27). Predictors of microsurgical breast reconstruction include involvement with resident education (odds ratio, 6.8; 95 percent CI, 3.32 to 13.91), microsurgical fellowship (odds ratio, 2.4; 95 percent CI, 1.16 to 4.95), and high breast reconstruction volume (odds ratio, 6.68; 95 percent CI, 1.76 to 25.27). The primary motivator for microsurgery is superior outcomes, and the primary deterrents are time and reimbursement. The proportion of U.S. plastic surgeons with a high-volume autologous or microsurgical breast reconstruction practice is low. Involvement with resident education appears to facilitate both, whereas time constraints and reimbursement are primary deterrents. Future efforts should focus on improving the feasibility and accessibility of all types of breast reconstruction.

Industrial applications of radiation chemistry; Perspectives industrielles de la chimie sous rayonnement

Energy Technology Data Exchange (ETDEWEB)

Puig, Jean Rene [Commissariat a l' energie atomique et aux energies alternatives - CEA, Service de chimie-physique, CEN de Saclay (France)

1959-07-01

The status of industrial applications of radiation chemistry as it stands 6 months after the second Geneva international conference is described. The main features of the interaction of ionizing radiations with matter are briefly stated and a review is made of the best studied and the more promising systems of radiation chemistry. The fields of organics, plastics, heterogeneous catalysis are emphasized. Economies of radiation production and utilization are discussed. Reprint of a paper published in Industries atomiques - no. 5-6, 1959.

Proceedings of the 3rd international symposium on material chemistry in nuclear environment (MATERIAL CHEMISTRY '02)

International Nuclear Information System (INIS)

2003-03-01

The volume contains all presented papers during the 3rd International Symposium on Material Chemistry in Nuclear Environment: MATERIAL CHEMISTRY 02 (MC'02), held March 13-15, 2002. The purpose of this symposium is to provide an international forum for the discussion of recent progress in the field of materials chemistry in nuclear environments. This symposium intends to build on the success of the previous symposiums held in Tsukuba in 1992 and 1996. The topics discussed in the symposium MC'02 are Chemical Reaction and Thermodynamics, Degradation Phenomena, New Characterization Technology, Fabrication and New Materials, Composite Materials, Surface Modification, and Computational Science. The 61 of the presented papers are indexed individually. (J.P.N.)

Plastic solidification system for radioactive waste

International Nuclear Information System (INIS)

Kani, Jiro; Irie, Hiromitsu; Obu, Etsuji; Nakayama, Yasuyuki; Matsuura, Hiroyuki.

1979-01-01

The establishment of a new solidification system is an important theme for recent radioactive-waste disposal systems. The conditions required of new systems are: (1) the volume of the solidified product to be reduced, and (2) the property of the solidified product to be superior to the conventional ones. In the plastic solidification system developed by Toshiba, the waste is first dried and then solidified with thermosetting resin. It has been confirmed that the property of the plastic solidified product is superior to that of the cement-or bitumen-solidified product. Investigation from various phases is being carried on for the application of this method to commercial plants. (author)

Gregory S. Ezra a festschrift from theoretical chemistry accounts

CERN Document Server

Keshavamurthy, Srihari

2015-01-01

In this Festschrift dedicated to the 60th birthday of Gregory S. Ezra, selected researchers in theoretical chemistry present research highlights on major developments in the field. Originally published in the journal Theoretical Chemistry Accounts, these outstanding contributions are now available in a hardcover print format, as well as a special electronic edition. This volume provides valuable content for all researchers in theoretical chemistry and will especially benefit those research groups and libraries with limited access to the journal.

Radiation processing of plastics for decorative purposes

International Nuclear Information System (INIS)

Knizhnik, R.I.; Onisko, A.D.

1982-01-01

Methods are reviewed for the radiation processing of polymeric films, sheets, plates and panels to form patterns, drawings, images and decorative finishing which have been recently developed in various countries. Methods of beam and radiation processing of transparent plastics are described for making a decorative article with a pattern inside the volume; advantages and shortcomings of the methods are shown. The method of radiation processing of transparent dielectric plastics by electron beam of a Microtron is considered in detail. It provides an economical method of fabrication of large-size highly artistic decorative articles with an original pattern inside the volume. Radiation processing operations are presented which are aimed at creation and visualization of regions of extended thermalized electron space charges stored by irradiation of dielectric. Examples are presented of large-size highly artistic decorative articles of polymethylmethacrylate which were used in interior of buildings and demonstrated at home and international exhibitions. (author)

Use of plastics in blast furnace processes: A contribution to ecologically and economically acceptable recycling of plastic waste; Kunststoffverwertung im Hochofen - ein Beitrag zum oekologischen und oekonomischen Recycling von Altkunststoffen

Energy Technology Data Exchange (ETDEWEB)

Janz, J [Stahlwerke Bremen GmbH (Germany)

1997-12-31

The use of plastics in blast furnace processes has a number of advantages. For one thing, existing facilities can be used with only slight reconstruction measures. Next, the blast furnace process does not necessarily require plastics and therefore is independent of the available plastics volume. Further, it has a high utilisation potential. For example, the Bremen blast furnace No. II has only 8 nozzles out of 32 which are suited for plastics, but it can utilize 70,000 t/a, which is more than 13 percent of the total plastics volume collected by DSD. Indepenent eco-balances have shown that there is no better technology on the market at the moment. (orig) [Deutsch] Mit der Kunststoffverwertung im Hochofen steht ein Verfahren zur Verfuegung, das sich gleich in mehrfacher Hinsicht vor der Konkurrenz auszeichnet. Im Gegensatz zu anderen Verwertungen wird eine bereits vorhandene Anlage genutzt, an der lediglich zusatzeinrichtungen benoetigt werden. Gleichzeitig wird abfallpolitische Flexibilitaet dadurch erreicht, dass der Hochofen nicht auf das Reduktionsmittel Kunststoff angewiesen ist. Von wesentlicher Bedeutung ist auch die hohe Verwertungskapazitaet eines Hochofens. Unabhaengige Oekobilanzen und eigene Messungen haben zweifelsfrei gezeigt, dass ein besseres Verfahren zur Zeit nicht auf dem Markt ist. (orig)

Use of plastics in blast furnace processes: A contribution to ecologically and economically acceptable recycling of plastic waste; Kunststoffverwertung im Hochofen - ein Beitrag zum oekologischen und oekonomischen Recycling von Altkunststoffen

Energy Technology Data Exchange (ETDEWEB)

Janz, J. [Stahlwerke Bremen GmbH (Germany)

1996-12-31

The use of plastics in blast furnace processes has a number of advantages. For one thing, existing facilities can be used with only slight reconstruction measures. Next, the blast furnace process does not necessarily require plastics and therefore is independent of the available plastics volume. Further, it has a high utilisation potential. For example, the Bremen blast furnace No. II has only 8 nozzles out of 32 which are suited for plastics, but it can utilize 70,000 t/a, which is more than 13 percent of the total plastics volume collected by DSD. Indepenent eco-balances have shown that there is no better technology on the market at the moment. (orig) [Deutsch] Mit der Kunststoffverwertung im Hochofen steht ein Verfahren zur Verfuegung, das sich gleich in mehrfacher Hinsicht vor der Konkurrenz auszeichnet. Im Gegensatz zu anderen Verwertungen wird eine bereits vorhandene Anlage genutzt, an der lediglich zusatzeinrichtungen benoetigt werden. Gleichzeitig wird abfallpolitische Flexibilitaet dadurch erreicht, dass der Hochofen nicht auf das Reduktionsmittel Kunststoff angewiesen ist. Von wesentlicher Bedeutung ist auch die hohe Verwertungskapazitaet eines Hochofens. Unabhaengige Oekobilanzen und eigene Messungen haben zweifelsfrei gezeigt, dass ein besseres Verfahren zur Zeit nicht auf dem Markt ist. (orig)

GREEN PLASTIC: A NEW PLASTIC FOR PACKAGING

OpenAIRE

Mr. Pankaj Kumar*, Sonia

2016-01-01

This paper gives a brief idea about a new type of plastic called as bio-plastic or green plastic. Plastic is used as a packaging material for various products, but this plastic is made up of non renewable raw materials. There are various disadvantages of using conventional plastic like littering, CO2 production, non-degradable in nature etc. To overcome these problems a new type of plastic is discovered called bio-plastic or green plastic. Bio-plastic is made from renewable resources and also...

Plastic in the Thames: a river runs through it.

Science.gov (United States)

Morritt, David; Stefanoudis, Paris V; Pearce, Dave; Crimmen, Oliver A; Clark, Paul F

2014-01-15

Although contamination of the marine ecosystems by plastics is becoming recognised as a serious pollution problem, there are few studies that demonstrate the contribution made by freshwater catchments. Over a three month period from September to December 2012, at seven localities in the upper Thames estuary, 8490 submerged plastic items were intercepted in eel fyke nets anchored to the river bed. Whilst there were significant differences in the numbers of items at these locations, the majority were some type of plastic. Additionally in excess of 20% of the litter items were components of sanitary products. The most contaminated sites were in the vicinity of sewage treatment works. While floating litter is visible, this study also demonstrates that a large unseen volume of submerged plastic is flowing into the marine environment. It is therefore important that this sub-surface component is considered when assessing plastic pollution input into the sea. Copyright © 2013 Elsevier Ltd. All rights reserved.

Genetic influences on individual differences in longitudinal changes in global and subcortical brain volumes: Results of the ENIGMA plasticity working group.

Science.gov (United States)

Brouwer, Rachel M; Panizzon, Matthew S; Glahn, David C; Hibar, Derrek P; Hua, Xue; Jahanshad, Neda; Abramovic, Lucija; de Zubicaray, Greig I; Franz, Carol E; Hansell, Narelle K; Hickie, Ian B; Koenis, Marinka M G; Martin, Nicholas G; Mather, Karen A; McMahon, Katie L; Schnack, Hugo G; Strike, Lachlan T; Swagerman, Suzanne C; Thalamuthu, Anbupalam; Wen, Wei; Gilmore, John H; Gogtay, Nitin; Kahn, René S; Sachdev, Perminder S; Wright, Margaret J; Boomsma, Dorret I; Kremen, William S; Thompson, Paul M; Hulshoff Pol, Hilleke E

2017-09-01

Structural brain changes that occur during development and ageing are related to mental health and general cognitive functioning. Individuals differ in the extent to which their brain volumes change over time, but whether these differences can be attributed to differences in their genotypes has not been widely studied. Here we estimate heritability (h 2 ) of changes in global and subcortical brain volumes in five longitudinal twin cohorts from across the world and in different stages of the lifespan (N = 861). Heritability estimates of brain changes were significant and ranged from 16% (caudate) to 42% (cerebellar gray matter) for all global and most subcortical volumes (with the exception of thalamus and pallidum). Heritability estimates of change rates were generally higher in adults than in children suggesting an increasing influence of genetic factors explaining individual differences in brain structural changes with age. In children, environmental influences in part explained individual differences in developmental changes in brain structure. Multivariate genetic modeling showed that genetic influences of change rates and baseline volume significantly overlapped for many structures. The genetic influences explaining individual differences in the change rate for cerebellum, cerebellar gray matter and lateral ventricles were independent of the genetic influences explaining differences in their baseline volumes. These results imply the existence of genetic variants that are specific for brain plasticity, rather than brain volume itself. Identifying these genes may increase our understanding of brain development and ageing and possibly have implications for diseases that are characterized by deviant developmental trajectories of brain structure. Hum Brain Mapp 38:4444-4458, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

An efficient method of material recycling of municipal plastic waste

Czech Academy of Sciences Publication Activity Database

Fortelný, Ivan; Michálková, Danuše; Kruliš, Zdeněk

2004-01-01

Roč. 85, č. 9 (2004), s. 975-979 ISSN 0141-3910. [IUPAC Microsymposium on Degradation, Stabilisation and Recycling of Polymers /42./. Prague, 14.07.2003-17.07.2003] R&D Projects: GA AV ČR(CZ) IBS4050008 Institutional research plan: CEZ:AV0Z4050913 Keywords : recycling * municipal plastic waste * compatibilisation Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.685, year: 2004

Development of volume reduction treatment techniques for low level radioactive wastes

International Nuclear Information System (INIS)

Nabatame, Yasuzi

1984-01-01

The solid wastes packed in drums are preserved in the stores of nuclear establishments in Japan, and the quantity of preservation has already reached about 60 % of the capacity. It has become an important subject to reduce the quantity of generation of radioactive wastes and how to reduce the volume of generated wastes. As the result of the research aiming at the development of the solidified bodies which are excellent in the effect of volume reduction and physical properties, it was confirmed that the plastic solidified bodies using thermosetting resin were superior to conventional cement or asphalt solidification. The plastic solidifying system can treat various radioactive wastes. After radioactive wastes are dried and powdered, they are solidified with plastics, therefore, the effect of volume reduction is excellent. The specific gravity, strength and the resistance to water, fire and radiation were confirmed to be satisfacotory. The plastic solidifying system comprises three subsystems, that is, drying system, powder storing and supplying system and plastic solidifying system. Also the granulation technique after drying and powdering, acid decomposition technique, the microwave melting and solidifying technique for incineration ash, plasma melting process and electrolytic polishing decontamination are described. (Kako, I.)

Quantification of air plasma chemistry for surface disinfection

International Nuclear Information System (INIS)

Pavlovich, Matthew J; Clark, Douglas S; Graves, David B

2014-01-01

Atmospheric-pressure air plasmas, created by a variety of discharges, are promising sources of reactive species for the emerging field of plasma biotechnology because of their convenience and ability to operate at ambient conditions. One biological application of ambient-air plasma is microbial disinfection, and the ability of air plasmas to decontaminate both solid surfaces and liquid volumes has been thoroughly established in the literature. However, the mechanism of disinfection and which reactive species most strongly correlate with antimicrobial effects are still not well understood. We describe quantitative gas-phase measurements of plasma chemistry via infrared spectroscopy in confined volumes, focusing on air plasma generated via surface micro-discharge (SMD). Previously, it has been shown that gaseous chemistry is highly sensitive to operating conditions, and the measurements we describe here extend those findings. We quantify the gaseous concentrations of ozone (O 3 ) and nitrogen oxides (NO and NO 2 , or NO x ) throughout the established ‘regimes’ for SMD air plasma chemistry: the low-power, ozone-dominated mode; the high-power, nitrogen oxides-dominated mode; and the intermediate, unstable transition region. The results presented here are in good agreement with previously published experimental studies of aqueous chemistry and parameterized models of gaseous chemistry. The principal finding of the present study is the correlation of bacterial inactivation on dry surfaces with gaseous chemistry across these time and power regimes. Bacterial decontamination is most effective in ‘NO x mode’ and less effective in ‘ozone mode’, with the weakest antibacterial effects in the transition region. Our results underscore the dynamic nature of air plasma chemistry and the importance of careful chemical characterization of plasma devices intended for biological applications. (paper)

Quantification of air plasma chemistry for surface disinfection

Science.gov (United States)

Pavlovich, Matthew J.; Clark, Douglas S.; Graves, David B.

2014-12-01

Atmospheric-pressure air plasmas, created by a variety of discharges, are promising sources of reactive species for the emerging field of plasma biotechnology because of their convenience and ability to operate at ambient conditions. One biological application of ambient-air plasma is microbial disinfection, and the ability of air plasmas to decontaminate both solid surfaces and liquid volumes has been thoroughly established in the literature. However, the mechanism of disinfection and which reactive species most strongly correlate with antimicrobial effects are still not well understood. We describe quantitative gas-phase measurements of plasma chemistry via infrared spectroscopy in confined volumes, focusing on air plasma generated via surface micro-discharge (SMD). Previously, it has been shown that gaseous chemistry is highly sensitive to operating conditions, and the measurements we describe here extend those findings. We quantify the gaseous concentrations of ozone (O3) and nitrogen oxides (NO and NO2, or NOx) throughout the established ‘regimes’ for SMD air plasma chemistry: the low-power, ozone-dominated mode; the high-power, nitrogen oxides-dominated mode; and the intermediate, unstable transition region. The results presented here are in good agreement with previously published experimental studies of aqueous chemistry and parameterized models of gaseous chemistry. The principal finding of the present study is the correlation of bacterial inactivation on dry surfaces with gaseous chemistry across these time and power regimes. Bacterial decontamination is most effective in ‘NOx mode’ and less effective in ‘ozone mode’, with the weakest antibacterial effects in the transition region. Our results underscore the dynamic nature of air plasma chemistry and the importance of careful chemical characterization of plasma devices intended for biological applications.

Advances in electron transfer chemistry

CERN Document Server

Mariano, Patrick S

1995-01-01

Advances in Electron Transfer Chemistry, Volume 4 presents the reaction mechanisms involving the movement of single electrons. This book discusses the electron transfer reactions in organic, biochemical, organometallic, and excited state systems. Organized into four chapters, this volume begins with an overview of the photochemical behavior of two classes of sulfonium salt derivatives. This text then examines the parameters that control the efficiencies for radical ion pair formation. Other chapters consider the progress in the development of parameters that control the dynamics and reaction p

Effects of Toxic Leachate from Commercial Plastics on Larval Survival and Settlement of the Barnacle Amphibalanus amphitrite.

Science.gov (United States)

Li, Heng-Xiang; Getzinger, Gordon J; Ferguson, P Lee; Orihuela, Beatriz; Zhu, Mei; Rittschof, Daniel

2016-01-19

Plastic pollution represents a major and growing global problem. It is well-known that plastics are a source of chemical contaminants to the aquatic environment and provide novel habitats for marine organisms. The present study quantified the impacts of plastic leachates from the seven categories of recyclable plastics on larval survival and settlement of barnacle Amphibalanus (=Balanus) amphitrite. Leachates from plastics significantly increased barnacle nauplii mortality at the highest tested concentrations (0.10 and 0.50 m(2)/L). Hydrophobicity (measured as surface energy) was positively correlated with mortality indicating that plastic surface chemistry may be an important factor in the effects of plastics on sessile organisms. Plastic leachates significantly inhibited barnacle cyprids settlement on glass at all tested concentrations. Settlement on plastic surfaces was significantly inhibited after 24 and 48 h, but settlement was not significantly inhibited compared to the controls for some plastics after 72-96 h. In 24 h exposure to seawater, we found larval toxicity and inhibition of settlement with all seven categories of recyclable commercial plastics. Chemical analysis revealed a complex mixture of substances released in plastic leachates. Leaching of toxic compounds from all plastics should be considered when assessing the risks of plastic pollution.

Proceedings of the 37. Brazilian Congress on Chemistry. Abstracts

International Nuclear Information System (INIS)

1997-01-01

This volume contains the summaries of the papers presented at the 37. Brazilian Congress on Chemistry. The topics include subjects about new technologies in the field of relevance for nuclear interest and energy field, involving environmental aspects, analytical chemistry and electrochemistry. The chemistry of elements of nuclear interest has been presented, and dissertations about rare earth elements were discussed. Studies about fuels, mainly petroleum, their products and biomass fuels, including their production, physical-chemical properties, structure studies and feasibility studies has also been comprehended

The aqueous chemistry of oxides

CERN Document Server

Bunker, Bruce C

2016-01-01

The Aqueous Chemistry of Oxides is a comprehensive reference volume and special topics textbook that explores all of the major chemical reactions that take place between oxides and aqueous solutions. The book highlights the enormous impact that oxide-water reactions have in advanced technologies, materials science, geochemistry, and environmental science.

Technetium Chemistry in High-Level Waste

International Nuclear Information System (INIS)

Hess, Nancy J.

2006-01-01

Tc contamination is found within the DOE complex at those sites whose mission involved extraction of plutonium from irradiated uranium fuel or isotopic enrichment of uranium. At the Hanford Site, chemical separations and extraction processes generated large amounts of high level and transuranic wastes that are currently stored in underground tanks. The waste from these extraction processes is currently stored in underground High Level Waste (HLW) tanks. However, the chemistry of the HLW in any given tank is greatly complicated by repeated efforts to reduce volume and recover isotopes. These processes ultimately resulted in mixing of waste streams from different processes. As a result, the chemistry and the fate of Tc in HLW tanks are not well understood. This lack of understanding has been made evident in the failed efforts to leach Tc from sludge and to remove Tc from supernatants prior to immobilization. Although recent interest in Tc chemistry has shifted from pretreatment chemistry to waste residuals, both needs are served by a fundamental understanding of Tc chemistry

Plastic strain induced damage evolution and martensitic transformation in ductile materials at cryogenic temperatures

International Nuclear Information System (INIS)

Garion, C.; Skoczen, B.T.

2002-01-01

The Fe-Cr-Ni stainless steels are well known for their ductile behavior at cryogenic temperatures. This implies development and evolution of plastic strain fields in the stainless steel components subjected to thermo-mechanical loads at low temperatures. The evolution of plastic strain fields is usually associated with two phenomena: ductile damage and strain induced martensitic transformation. Ductile damage is described by the kinetic law of damage evolution. Here, the assumption of isotropic distribution of damage (microcracks and microvoids) in the Representative Volume Element (RVE) is made. Formation of the plastic strain induced martensite (irreversible process) leads to the presence of quasi-rigid inclusions of martensite in the austenitic matrix. The amount of martensite platelets in the RVE depends on the intensity of the plastic strain fields and on the temperature. The evolution of the volume fraction of martensite is governed by a kinetic law based on the accumulated plastic strain. Both of these irreversible phenomena, associated with the dissipation of plastic power, are included into the constitutive model of stainless steels at cryogenic temperatures. The model is tested on the thin-walled corrugated shells (known as bellows expansion joints) used in the interconnections of the Large Hadron Collider, the new proton storage ring being constructed at present at CERN

Pyrolysis of plastic packaging waste: A comparison of plastic residuals from material recovery facilities with simulated plastic waste.

Science.gov (United States)

Adrados, A; de Marco, I; Caballero, B M; López, A; Laresgoiti, M F; Torres, A

2012-05-01

Pyrolysis may be an alternative for the reclamation of rejected streams of waste from sorting plants where packing and packaging plastic waste is separated and classified. These rejected streams consist of many different materials (e.g., polyethylene (PE), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), polyethylene terephthalate (PET), acrylonitrile butadiene styrene (ABS), aluminum, tetra-brik, and film) for which an attempt at complete separation is not technically possible or economically viable, and they are typically sent to landfills or incinerators. For this study, a simulated plastic mixture and a real waste sample from a sorting plant were pyrolyzed using a non-stirred semi-batch reactor. Red mud, a byproduct of the aluminum industry, was used as a catalyst. Despite the fact that the samples had a similar volume of material, there were noteworthy differences in the pyrolysis yields. The real waste sample resulted, after pyrolysis, in higher gas and solid yields and consequently produced less liquid. There were also significant differences noted in the compositions of the compared pyrolysis products. Copyright © 2011 Elsevier Ltd. All rights reserved.

Liquid phase solvent bonding of plastic microfluidic devices assisted by retention grooves.

Science.gov (United States)

Wan, Alwin M D; Sadri, Amir; Young, Edmond W K

2015-01-01

We report a novel method for achieving consistent liquid phase solvent bonding of plastic microfluidic devices via the use of retention grooves at the bonding interface. The grooves are patterned during the regular microfabrication process, and can be placed at the periphery of a device, or surrounding microfluidic features with open ports, where they effectively mitigate solvent evaporation, and thus substantially reduce poor bond coverage. This method is broadly applicable to a variety of plastics and solvents, and produces devices with high bond quality (i.e., coverage, strength, and microfeature fidelity) that are suitable for studies in physics, chemistry, and cell biology at the microscale.

Preparation of plastic scintillation detectors and characterization of physico-chemical parameters

International Nuclear Information System (INIS)

Hamada, M.M.; Mesquita, C.H. de

1988-01-01

The development of plastic scintillators for using in the nuclear radiation detection is described. The detectors were fabricated by the polymerization of styrene with organic fluors. The organic fluors used were PPO (1,4 difenil-oxazol) and POPOP 1,4-di-2-(5-fenil-oxazolil) benzene in proportions of 0,5 and 0,05% respectively. Physical-chemistry parameters related to the quality of this detector are investigated at this laboratory. The evaluation of its fluorescency characteristics, density, melting softening, refractive index, molecular weight, gama and alfa espectrometry characteristics and finally the comparative pulse height analysis indicate that the plastic scintillator produced at this laboratory is comparable with others already described. (author) [pt

Basic radiation physics and chemistry of composites

International Nuclear Information System (INIS)

Przybytniak, G.; Zagorski, Z.P.

2006-01-01

Composites are increasingly more important in the applied and fundamental polymer science, and the participation of radiation processing of these systems increase. In presented paper the newest achievements of radiation physics and chemistry of composites are reviewed. It is stressed, that although main experimental effort is directed towards the development of composites as such, and investigation of their specific properties, mechanical, physicochemical and physical, the radiation processing will enter the field on the wider scale, especially as concerns specialized plastics

Electron Transfer in Chemistry and Biology – The Primary Events

Indian Academy of Sciences (India)

Home; Journals; Resonance – Journal of Science Education; Volume 2; Issue 12. Electron Transfer in Chemistry and Biology – The Primary Events in Photosynthesis. V Krishnan. General Article Volume 2 Issue 12 December 1997 pp 77-86. Fulltext. Click here to view fulltext PDF. Permanent link:

Marco Antonio Chaer Nascimento a festschrift from theoretical chemistry accounts

CERN Document Server

Ornellas, Fernando R

2014-01-01

In this Festschrift dedicated to the 65th birthday of Marco Antonio Chaer Nascimento, selected researchers in theoretical chemistry present research highlights on major developments in the field. Originally published in the journal Theoretical Chemistry Accounts, these outstanding contributions are now available in a hardcover print format. This volume will be of benefit in particular to those research groups and libraries that have chosen to have only electronic access to the journal. It also provides valuable content for all researchers in theoretical chemistry.

Plastic debris retention and exportation by a mangrove forest patch

International Nuclear Information System (INIS)

Ivar do Sul, Juliana A.; Costa, Monica F.; Silva-Cavalcanti, Jacqueline S.; Araújo, Maria Christina B.

2014-01-01

Highlights: • Estuaries and mangrove forests are rarely studied for marine plastic debris loads. • Types of plastic items and mangrove forest habitats determine the potential of debris retention. • Mangrove habitats are temporary sinks of plastic debris from river and marine origins. • Plastics rapidly accumulate in mangrove forest, but are exported slowly. • Fauna and fishers using mangrove forest habitats are at risk of interaction with plastic debris. -- Abstract: An experiment observed the behavior of selected tagged plastic items deliberately released in different habitats of a tropical mangrove forest in NE Brazil in late rainy (September) and late dry (March) seasons. Significant differences were not reported among seasons. However, marine debris retention varied among habitats, according to characteristics such as hydrodynamic (i.e., flow rates and volume transported) and relative vegetation (Rhizophora mangle) height and density. The highest grounds retained significantly more items when compared to the borders of the river and the tidal creek. Among the used tagged items, PET bottles were more observed and margarine tubs were less observed, being easily transported to adjacent habitats. Plastic bags were the items most retained near the releasing site. The balance between items retained and items lost was positive, demonstrating that mangrove forests tend to retain plastic marine debris for long periods (months-years)

Resident operative experience in general surgery, plastic surgery, and urology 5 years after implementation of the ACGME duty hour policy.

Science.gov (United States)

Simien, Christopher; Holt, Kathleen D; Richter, Thomas H; Whalen, Thomas V; Coburn, Michael; Havlik, Robert J; Miller, Rebecca S

2010-08-01

Resident duty hour restrictions were implemented in 2002-2003. This study examines changes in resident surgical experience since these restrictions were put into place. Operative log data for 3 specialties were examined: general surgery, urology, and plastic surgery. The academic year immediately preceding the duty hour restrictions, 2002-2003, was used as a baseline for comparison to subsequent academic years. Operative log data for graduating residents through 2007-2008 were the primary focus of the analysis. Examination of associated variables that may moderate the relationship between fewer duty hours and surgical volume was also included. Plastic surgery showed no changes in operative volume following duty hour restrictions. Operative volume increased in urology programs. General surgery showed a decrease in volume in some operative categories but an increase in others. Specifically the procedures in vascular, plastic, and thoracic areas showed a consistent decrease. There was no increase in the percentage of programs' graduates falling below minimum requirements. Procedures in pancreas, endocrine, and laparoscopic areas demonstrated an increase in volume. Graduates in larger surgical programs performed fewer procedures than graduates in smaller programs; this was not the case for urology or plastic surgery programs. The reduction of duty hours has not resulted in an across the board decrease in operative volume. Factors other than duty hour reforms may be responsible for some of the observed findings.

Catalytic Pyrolysis of Waste Plastic Mixture

Science.gov (United States)

Sembiring, Ferdianta; Wahyu Purnomo, Chandra; Purwono, Suryo

2018-03-01

Inorganic waste especially plastics still become a major problem in many places. Low biodegradability of this materials causes the effort in recycling become very difficult. Most of the municipal solid waste (MSW) recycling facilities in developing country only use composting method to recover the organic fraction of the waste, while the inorganic fraction is still untreated. By pyrolysis, plastic waste can be treated to produce liquid fuels, flammable gas and chars. Reduction in volume and utilization of the liquid and gas as fuel are the major benefits of the process. By heat integration actually this process can become a self-sufficient system in terms of energy demand. However, the drawback of this process is usually due to the diverse type of plastic in the MSW creating low grade of liquid fuel and harmful gases. In this study, the mixture of plastics i.e. polypropylene (PP) and polyethylene terephthalate (PET) is treated using pyrolysis with catalyst in several operating temperature. PET is problematic to be treated using pyrolysis due to wax-like byproduct in liquid which may cause pipe clogging. The catalyst is the mixture of natural zeolite and bentonite which is able to handle PP and PET mixture feed to produce high grade liquid fuels in terms of calorific value and other fuel properties.

A plastic micropump constructed with conventional techniques and materials

NARCIS (Netherlands)

Bohm, S.; Olthuis, Wouter; Bergveld, Piet

1999-01-01

A plastic micropump which can be produced using conventional production techniques and materials is presented. By applying well-known techniques and materials, economic fabrication of micropumps for various applications is feasible even at low production volumes. The micropump is capable of pumping

Alpha spectrometry without chemistry

International Nuclear Information System (INIS)

Murray, A.S.; Heaton, B.

1983-01-01

A gridded cylindrical pulse ionization chamber is considered for the simultaneous analysis of natural alpha emitters. Solid sources of up to 0.3 g are deposited after wet grinding as a thin layer on 1.1 m 2 of aluminized plastic film, which acts as the cathode. No chemistry is involved, and thus there is little chance of nuclide fractionation. With a ''weightless'' source the resolution is about 55 keV; 110 keV has been easily achieved at 4.2 MeV with real sources. We conclude that significant information about isotope activities in the natural series is available with only a fraction of the work involved in conventional techniques. (author)

Mechanism of Notch Pathway Activation and Its Role in the Regulation of Olfactory Plasticity in Drosophila melanogaster.

Directory of Open Access Journals (Sweden)

Simon Kidd

Full Text Available The neural plasticity of sensory systems is being increasingly recognized as playing a role in learning and memory. We have previously shown that Notch, part of an evolutionarily conserved intercellular signaling pathway, is required in adult Drosophila melanogaster olfactory receptor neurons (ORNs for the structural and functional plasticity of olfactory glomeruli that is induced by chronic odor exposure. In this paper we address how long-term exposure to odor activates Notch and how Notch in conjunction with chronic odor mediates olfactory plasticity. We show that upon chronic odor exposure a non-canonical Notch pathway mediates an increase in the volume of glomeruli by a mechanism that is autonomous to ORNs. In addition to activating a pathway that is autonomous to ORNs, chronic odor exposure also activates the Notch ligand Delta in second order projection neurons (PNs, but this does not appear to require acetylcholine receptor activation in PNs. Delta on PNs then feeds back to activate canonical Notch signaling in ORNs, which restricts the extent of the odor induced increase in glomerular volume. Surprisingly, even though the pathway that mediates the increase in glomerular volume is autonomous to ORNs, nonproductive transsynaptic Delta/Notch interactions that do not activate the canonical pathway can block the increase in volume. In conjunction with chronic odor, the canonical Notch pathway also enhances cholinergic activation of PNs. We present evidence suggesting that this is due to increased acetylcholine release from ORNs. In regulating physiological plasticity, Notch functions solely by the canonical pathway, suggesting that there is no direct connection between morphological and physiological plasticity.

Proceedings of DAE-BRNS third international symposium on materials chemistry

International Nuclear Information System (INIS)

Tyagi, Deepak; Banerjee, Atindra Mohan; Nigam, Sandeep; Varma, Salil; Tripathi, Arvind Kumar; Bharadwaj, Shyamala Rajkumar; Das, Dasarathi

2010-12-01

The present volume consists of the proceedings of the DAE-BRNS Third International Symposium on Materials Chemistry. In order to keep pace with the advancements made in the area of materials chemistry, new topics like materials for energy conversion, biomaterials, carbon based materials, soft condensed materials, thin films, surface chemistry, polymer based materials, organic and organometallics, magnetic materials and high purity materials have been included in this symposium while topics like nuclear materials, nanomaterials and clusters, catalysis, chemical sensors, fuel cell materials and computational research in materials chemistry have been continued as important features of the symposium. Papers relevant to INIS are indexed separately

Microscale Experiments in Chemistry-The Need of the New Millennium

Indian Academy of Sciences (India)

Home; Journals; Resonance – Journal of Science Education; Volume 5; Issue 10. Microscale Experiments in Chemistry – The Need of the New Millennium-Newer Ways of Teaching Laboratory Courses with New Apparatus. Shriniwas L Kelkar Dilip D Dhavale. Series Article Volume 5 Issue 10 October 2000 pp 24-31 ...

Compatibility Assessment of Fuel System Infrastructure Plastics with Bio-oil and Diesel Fuel

Energy Technology Data Exchange (ETDEWEB)

Kass, Michael D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Fuels, Engines and Emissions Research Center; Janke, Christopher James [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Fuels, Engines and Emissions Research Center; Connatser, Raynella M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Fuels, Engines and Emissions Research Center; Lewis, Samuel Arthur [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Fuels, Engines and Emissions Research Center; Keiser, James R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Fuels, Engines and Emissions Research Center; Gaston, Katherine [National Renewable Energy Lab. (NREL), Golden, CO (United States). National Bioenergy Center

2017-12-05

We report that bio-oil derived via fast pyrolysis is being developed as a renewable fuel option for petroleum distillates. The compatibility of neat bio-oil with 18 plastic types was evaluated using neat diesel fuel as the baseline. The plastic materials included polyphenylene sulfide (PPS), polyethylene terephthalate (PET), polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), polyoxymethylene (POM), POM copolymer, high density polyethylene (HDPE), polybutylene terephthalate (PBT), polypropylene (PP), polyethylene terephthalate glycol (PETG), polythiourea (PTU), four nylon grades, and four thermosetting resins. Specimens of each material were immersed in the test fuels for a period of 16 weeks to achieve full saturation. Except for PP and HDPE, the plastic materials underwent higher volume expansion in bio-oil than in the baseline diesel (which was negligible in most cases). This volume increase corresponds to the higher polarity of the bio-oil. PPS, PET, and PTFE were unaffected by bio-oil exposure, but modest swelling (between 2 and 5%) occurred for the two acetals (POM and POM copolymer), Nylon-12, PBT, PETG, and the four resin grades. More moderate swelling (8–15%) was noted for Nylon-6, Nylon-6/6, and Nylon-11, and excessive swell (>40%) occurred for PTU. The nonpolar nature of PP and HDPE matches that of diesel, leading to higher solubility (swell) in this fuel type. Finally, the relatively low volume expansion following exposure indicates that many of the existing infrastructure plastics (excluding PTU) should be suitable for use with bio-oil.

ANALYSIS OF STRUCTURAL PLASTICITY IN THE HONEY BEE BRAIN USING THE CAVALIERI ESTIMATOR OF VOLUME AND THE DISECTOR METHOD

Directory of Open Access Journals (Sweden)

Sheena M Brown

2011-05-01

Full Text Available The antennal lobe of the worker honey bee has been used as a model system to address the origins of structural plasticity in the central nervous system. A combination of light and electron microscopy was used to determine total synapse number within an easily identifiable sub-unit of the antennal lobe neuropil, the T4-2(1 glomerulus. The Cavalieri method was applied at the light microscope level to determine a reference volume (Vref of this glomerulus. Using transmission electron microscopy, the physical disector was used to determine synaptic density (Nv within the T4-2(1 glomerulus. An estimate of the total synapse number N(syn was determined by; N(syn = V(ref Nv. Newly emerged, 4-day old,10-day old and forager-aged bees were analysed. Results showed that despite a significant increase in T4-2(1 volume with age, the total number of synapses in this glomerulus did not show a corresponding increase. Disturbingly, it is possible that huge variances within age groups, due to one or two outlying data points, could be masking the true trend of synapse number. This variance, the heterogeneous distribution of synapses within this glomerulus and the problems associated with reproducibility of synapse counts are discussed.

Physico-chemical properties of excavated plastic from landfill mining and current recycling routes.

Science.gov (United States)

Canopoli, L; Fidalgo, B; Coulon, F; Wagland, S T

2018-06-01

In Europe over 5.25 billion tonnes of waste has been landfilled between 1995 and 2015. Among this large amount of waste, plastic represents typically 5-25 wt% which is significant and has the potential to be recycled and reintroduced into the circular economy. To date there is still however little information available of the opportunities and challenges in recovering plastics from landfill sites. In this review, the impacts of landfill chemistry on the degradation and/or contamination of excavated plastic waste are analysed. The feasibility of using excavated plastic waste as feedstock for upcycling to valuable chemicals or liquid fuels through thermochemical conversion is also critically discussed. The limited degradation that is experienced by many plastics in landfills (>20 years) which guarantee that large amount is still available is largely due to thermooxidative degradation and the anaerobic conditions. However, excavated plastic waste cannot be conventionally recycled due to high level of ash, impurities and heavy metals. Recent studies demonstrated that pyrolysis offers a cost effective alternative option to conventional recycling. The produced pyrolysis oil is expected to have similar characteristics to petroleum diesel oil. The production of valuable product from excavated plastic waste will also increase the feasibility of enhanced landfill mining projects. However, further studies are needed to investigate the uncertainties about the contamination level and degradation of excavated plastic waste and address their viability for being processed through pyrolysis. Copyright © 2018 Elsevier Ltd. All rights reserved.

4 π physics with the plastic ball

International Nuclear Information System (INIS)

Gutbrod, H.H.; Loehner, H.; Poskanzer, A.M.; Renner, T.; Riedesel, H.; Ritter, H.G.; Warwick, A.; Weik, F.; Wieman, H.

1982-10-01

4 π data taken with the Plastic Ball show that cluster production in relativistic nuclear collisions depends on both the size of the participant volume and the finite size of the cluster. The measurement of the degree of thermalization and the search for collective flow will permit the study of the applicability of macroscopic concepts such as temperature and density

Radiation chemistry of plastic crystals. Annual progress report, November 1, 1975--October 31, 1976

International Nuclear Information System (INIS)

Klingen, T.J.

1976-01-01

Results of research on synthesis and plastic crystallinity of adamantane derivatives are presented. Results of electo-optical studies are included along with results of 1-phenyl-o-carborane radiolysis, co-polymerization of o-carborane, and 1-vinyl-o-carborane

Presidential Green Chemistry Challenge: 1998 Greener Synthetic Pathways Award

Science.gov (United States)

Presidential Green Chemistry Challenge 1998 award winner, Flexsys America, developed nucleophilic aromatic substitution for hydrogen to eliminate waste from a common reaction and to produce 4-ADPA, a high-volume chemical.

Assessment of the breast volume by a new simple formula

Directory of Open Access Journals (Sweden)

El-Oteify Mahmoud

2006-01-01

Full Text Available Background: With the recent introduction of improved techniques for plastic surgery of the breast and increased public awareness toward these procedures, plastic surgeons are continuously trying to improve their methods and results to reach perfection. Assessment of the breast volume is an important issue prior to the use of breast implants in any aesthetic or reconstructive breast surgery. Previous methods to measure breast volume have included use of a simple bra and breast cup size, cumbersome fluid displacement, appliances and approximate visual estimation. Objectives: In this work we have tried to develop an easy method for assessment of the breast volume for both the patient and the the surgeon through a simple mathematical formula. Materials and Methods: Fifty two volunteers were included in this study. For every one, general parameters including age, weight and height were recorded. Local breast measurements and water volume displacement were also recorded. Results: The collected data were statistically correlated. Using the analyzed data, the breast volume was calculated through a simple and direct formula on the basis of the breast circumference. Conclusion: Our method has, as its principle, the use of an accurate and simple formula, which is based only on one measurement. This is easy for both the patient and the plastic surgeon. This equation is not only a significant technical advantage for the surgeon, but also provides a universal standardization of the breast volume.

A facile route for irreversible bonding of plastic-PDMS hybrid microdevices at room temperature.

Science.gov (United States)

Tang, Linzhi; Lee, Nae Yoon

2010-05-21

Plastic materials do not generally form irreversible bonds with poly(dimethylsiloxane) (PDMS) regardless of oxygen plasma treatment and a subsequent thermal process. In this paper, we perform plastic-PDMS bonding at room temperature, mediated by the formation of a chemically robust amine-epoxy bond at the interfaces. Various plastic materials, such as poly(methylmethacrylate) (PMMA), polycarbonate (PC), polyimide (PI), and poly(ethylene terephthalate) (PET) were adopted as choices for plastic materials. Irrespective of the plastic materials used, the surfaces were successfully modified with amine and epoxy functionalities, confirmed by the surface characterizations such as water contact angle measurements and X-ray photoelectron spectroscopy (XPS), and chemically robust and irreversible bonding was successfully achieved within 1 h at room temperature. The bonding strengths of PDMS with PMMA and PC sheets were measured to be 180 and 178 kPa, respectively, and their assemblies containing microchannel structures endured up to 74 and 84 psi (510 and 579 kPa) of introduced compressed air, respectively, without destroying the microdevices, representing a robust and highly stable interfacial bonding. In addition to microchannel-molded PDMS bonded with flat plastic substrates, microchannel-embossed plastics were also bonded with a flat PDMS sheet, and both types of bonded assemblies displayed sufficiently robust bonding, tolerating an intense influx of liquid whose per-minute injection volume was nearly 1000 to 2000 times higher than the total internal volume of the microchannel used. In addition to observing the bonding performance, we also investigated the potential of surface amine and epoxy functionalities as durable chemical adhesives by observing their storage-time-dependent bonding performances.

Gammastic: towards a pseudo-gamma spectrometry in plastic scintillators

International Nuclear Information System (INIS)

Hamel, Matthieu; Dehe-Pittance, Chrystele; Coulon, Romain; Carrel, Frederick; Pillot, Philippe; Barat, Eric; Dautremer, Thomas; Montagu, Thierry; Normand, Stephane

2013-06-01

War against CBRN-E threats needs to continuously develop sensors with improved detection efficiency. More particularly, this topic concerns the NR controls for homeland security. A first analysis requires indeed a fast gamma spectrometry so as to detect potential special nuclear materials (SNM). To this aim, plastic scintillators could represent the best alternative for the production of large-scale, low-cost radiation portal monitors to be deployed on boarders, tolls, etc. Although they are known to be highly sensitive to gamma rays, due to their poor resolution, information relative to the nature of the SNM is tricky. Thus, only the Compton edge is obtained after interaction, and no information of the photoelectric peak is observed. This project concerns new developments on a possible pseudo-gamma spectrometry performed with plastic scintillators. This project is articulated on a combination of two developments: - The design of new materials most suitable for recovering the photoelectric peak after gamma interaction with the scintillator. This work concerns mainly plastic scintillators loading with heavy elements, such as lead or bismuth. - The analysis of the resulting signal with smart algorithms. This work is thus a pluri-disciplinary work performed at CEA LIST and embeds 4 main disciplines: MCNPX simulations (simulated spectra), chemistry of materials (preparation of various plastic scintillators with different properties), instrumentation (lab experiments) and smart algorithms. Really impressive results were obtained with the unfolding of simulated spectra at various energies (from 241 Am to 60 Co) and an innovative approach was proposed to counter-balance the quenching effect of luminescence by heavy elements in plastic scintillators. (authors)

Biobased chemicals: the convergence of green chemistry with industrial biotechnology.

Science.gov (United States)

Philp, Jim C; Ritchie, Rachael J; Allan, Jacqueline E M

2013-04-01

Policy issues around biobased chemicals are similar to those for biobased plastics. However, there are significant differences that arise from differences in production volumes and the more specific applications of most chemicals. The drivers for biobased chemicals production are similar to those for biobased plastics, particularly the environmental drivers. However, in Europe, biobased chemical production is further driven by the need to improve the competitiveness of the chemicals industry. Copyright © 2013 Elsevier Ltd. All rights reserved.

Ocean acidification challenges copepod phenotypic plasticity

Science.gov (United States)

Vehmaa, Anu; Almén, Anna-Karin; Brutemark, Andreas; Paul, Allanah; Riebesell, Ulf; Furuhagen, Sara; Engström-Öst, Jonna

2016-11-01

Ocean acidification is challenging phenotypic plasticity of individuals and populations. Calanoid copepods (zooplankton) are shown to be fairly plastic against altered pH conditions, and laboratory studies indicate that transgenerational effects are one mechanism behind this plasticity. We studied phenotypic plasticity of the copepod Acartia sp. in the course of a pelagic, large-volume mesocosm study that was conducted to investigate ecosystem and biogeochemical responses to ocean acidification. We measured copepod egg production rate, egg-hatching success, adult female size and adult female antioxidant capacity (ORAC) as a function of acidification (fCO2 ˜ 365-1231 µatm) and as a function of quantity and quality of their diet. We used an egg transplant experiment to reveal whether transgenerational effects can alleviate the possible negative effects of ocean acidification on offspring development. We found significant negative effects of ocean acidification on adult female size. In addition, we found signs of a possible threshold at high fCO2, above which adaptive maternal effects cannot alleviate the negative effects of acidification on egg-hatching and nauplii development. We did not find support for the hypothesis that insufficient food quantity (total particulate carbon < 55 µm) or quality (C : N) weakens the transgenerational effects. However, females with high-ORAC-produced eggs with high hatching success. Overall, these results indicate that Acartia sp. could be affected by projected near-future CO2 levels.

Methacrylate based cross-linkers for improved thermomechanical properties and retention of radiation detection response in plastic scintillators

Science.gov (United States)

Mahl, Adam; Lim, Allison; Latta, Joseph; Yemam, Henok A.; Greife, Uwe; Sellinger, Alan

2018-03-01

Pulse shape discrimination (PSD) is an important method that can efficiently sort and separate neutron and gamma radiation signals. PSD is currently achieved in plastic scintillators by over-doping poly(vinyl toluene) (PVT) matrices with fluorescent molecules. Meaningful separation of the signals requires addition of >20 wt% 2,5-diphenyloxazole (PPO) fluor in PVT. At these concentrations PPO acts as a plasticizer, negatively affecting the physical properties of the final plastic such as hardness, machinability, and thermomechanical stability. This work addresses these issues by implementing a cost-effective solution using cross-linking chemistry via commercially available bisphenol A dimethacrylate (BPA-DM), and a synthesized fluorinated analogue. Both improve the physical properties of over-doped PPO based plastic scintillators without degrading the measured light yield or PSD and Figure of Merit (FoM). In addition, the fluorinated analogue appears to enhance the hydrophobicity of the surface of the plastic scintillators, which may improve the scintillators' resistance to water diffusion and subsequent radiation response degradation. The new formulations improve the feasibility of widely deploying long lifetime PSD capable plastic scintillators in large area coverage assemblies.

Psychedelics Promote Structural and Functional Neural Plasticity

Directory of Open Access Journals (Sweden)

Calvin Ly

2018-06-01

Full Text Available Summary: Atrophy of neurons in the prefrontal cortex (PFC plays a key role in the pathophysiology of depression and related disorders. The ability to promote both structural and functional plasticity in the PFC has been hypothesized to underlie the fast-acting antidepressant properties of the dissociative anesthetic ketamine. Here, we report that, like ketamine, serotonergic psychedelics are capable of robustly increasing neuritogenesis and/or spinogenesis both in vitro and in vivo. These changes in neuronal structure are accompanied by increased synapse number and function, as measured by fluorescence microscopy and electrophysiology. The structural changes induced by psychedelics appear to result from stimulation of the TrkB, mTOR, and 5-HT2A signaling pathways and could possibly explain the clinical effectiveness of these compounds. Our results underscore the therapeutic potential of psychedelics and, importantly, identify several lead scaffolds for medicinal chemistry efforts focused on developing plasticity-promoting compounds as safe, effective, and fast-acting treatments for depression and related disorders. : Ly et al. demonstrate that psychedelic compounds such as LSD, DMT, and DOI increase dendritic arbor complexity, promote dendritic spine growth, and stimulate synapse formation. These cellular effects are similar to those produced by the fast-acting antidepressant ketamine and highlight the potential of psychedelics for treating depression and related disorders. Keywords: neural plasticity, psychedelic, spinogenesis, synaptogenesis, depression, LSD, DMT, ketamine, noribogaine, MDMA

Psychedelics Promote Structural and Functional Neural Plasticity.

Science.gov (United States)

Ly, Calvin; Greb, Alexandra C; Cameron, Lindsay P; Wong, Jonathan M; Barragan, Eden V; Wilson, Paige C; Burbach, Kyle F; Soltanzadeh Zarandi, Sina; Sood, Alexander; Paddy, Michael R; Duim, Whitney C; Dennis, Megan Y; McAllister, A Kimberley; Ori-McKenney, Kassandra M; Gray, John A; Olson, David E

2018-06-12

Atrophy of neurons in the prefrontal cortex (PFC) plays a key role in the pathophysiology of depression and related disorders. The ability to promote both structural and functional plasticity in the PFC has been hypothesized to underlie the fast-acting antidepressant properties of the dissociative anesthetic ketamine. Here, we report that, like ketamine, serotonergic psychedelics are capable of robustly increasing neuritogenesis and/or spinogenesis both in vitro and in vivo. These changes in neuronal structure are accompanied by increased synapse number and function, as measured by fluorescence microscopy and electrophysiology. The structural changes induced by psychedelics appear to result from stimulation of the TrkB, mTOR, and 5-HT2A signaling pathways and could possibly explain the clinical effectiveness of these compounds. Our results underscore the therapeutic potential of psychedelics and, importantly, identify several lead scaffolds for medicinal chemistry efforts focused on developing plasticity-promoting compounds as safe, effective, and fast-acting treatments for depression and related disorders. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

Radioanalytical chemistry. Vol. 2

International Nuclear Information System (INIS)

Toelgyessy, J.; Kyrs, M.

1989-01-01

This volume of the monograph covers the following topics: activation analysis, non-activation interaction analysis (elastic scattering of charged particles, absorption and backscattering of beta radiation and photons, radionuclide X-ray fluorescence analysis, thermalization, scattering and absorption of neutrons, use of ionization caused by nuclear radiation, use of ionization by alpha or beta radiation for the measurement of pressure, density and flow rate of gases), and automation in radioanalytical chemistry. (P.A.)

Biofouling on buoyant marine plastics: An experimental study into the effect of size on surface longevity

International Nuclear Information System (INIS)

Fazey, Francesca M.C.; Ryan, Peter G.

2016-01-01

Recent estimates suggest that roughly 100 times more plastic litter enters the sea than is found floating at the sea surface, despite the buoyancy and durability of many plastic polymers. Biofouling by marine biota is one possible mechanism responsible for this discrepancy. Microplastics (<5 mm in diameter) are more scarce than larger size classes, which makes sense because fouling is a function of surface area whereas buoyancy is a function of volume; the smaller an object, the greater its relative surface area. We tested whether plastic items with high surface area to volume ratios sank more rapidly by submerging 15 different sizes of polyethylene samples in False Bay, South Africa, for 12 weeks to determine the time required for samples to sink. All samples became sufficiently fouled to sink within the study period, but small samples lost buoyancy much faster than larger ones. There was a direct relationship between sample volume (buoyancy) and the time to attain a 50% probability of sinking, which ranged from 17 to 66 days of exposure. Our results provide the first estimates of the longevity of different sizes of plastic debris at the ocean surface. Further research is required to determine how fouling rates differ on free floating debris in different regions and in different types of marine environments. Such estimates could be used to improve model predictions of the distribution and abundance of floating plastic debris globally. - Highlights: • We tested how fragment size affects the rate of buoyancy loss at sea due to biofouling for two low-density plastic polymers. • We found a strong direct relationship between fragment size and surface longevity. • Our longevity estimates ranged from 17 days for the thinnest microplastics to 66 days for thicker macroplastics. • Our results provide the first estimates of the longevity of different sizes of plastic debris at the ocean surface. • The results could be used to improve model predictions of the

Recrystallization kinetics of nanostructured copper processed by dynamic plastic deformation

DEFF Research Database (Denmark)

Lin, Fengxiang; Zhang, Yubin; Pantleon, Wolfgang

2012-01-01

The recrystallization kinetics of nanostructured copper samples processed by dynamic plastic deformation was investigated by electron backscatter diffraction. It was found that the evolution of the recrystallized volume fraction as a function of annealing time has a very low slope (n=0.37) when...

Radwaste volume reduction and solidification by General Electric

International Nuclear Information System (INIS)

Green, T.A.; Weech, M.E.; Miller, G.P.; Eberle, J.W.

1982-01-01

Since 1978 General Electric has been actively engaged in developing a volume reduction and solidifcation system or treatment of radwaste generated in commercial nuclear power plants. The studies have been aimed at defining an integrated system that would be directly responsive to the rapid evolving needs of the industry for the volume reduction and solidification of low-level radwaste. The resulting General Electric Volume Reduction System (GEVRS) is an integrated system based on two processes: the first uses azeotropic distillation technology and is called AZTECH, and the second is controlled-air incineration...called INCA. The AZTECH process serves to remove water from concentrated salt solutions, ion exchange resins and filter sludge slurries and then encapsulates the dried solids into a dense plastic product. The INCA unit serves to reduce combustible wastes to ashes suitable for encapsulation into the same plastic product produced by AZTECH

Effect of steel fibers on plastic shrinkage cracking of normal and high strength concretes

Directory of Open Access Journals (Sweden)

Özgür Eren

2010-06-01

Full Text Available Naturally concrete shrinks when it is subjected to a drying environment. If this shrinkage is restrained, tensile stresses develop and concrete may crack. Plastic shrinkage cracks are especially harmful on slabs. One of the methods to reduce the adverse effects of shrinkage cracking of concrete is by reinforcing concrete with short randomly distributed fibers. The main objective of this study was to investigate the effect of fiber volume and aspect ratio of hooked steel fibers on plastic shrinkage cracking behavior together with some other properties of concrete. In this research two different compressive strength levels namely 56 and 73 MPa were studied. Concretes were produced by adding steel fibers of 3 different volumes of 3 different aspect ratios. From this research study, it is observed that steel fibers can significantly reduce plastic shrinkage cracking behavior of concretes. On the other hand, it was observed that these steel fibers can adversely affect some other properties of concrete during fresh and hardened states.

Effect of plastic strain on the evolution of crystallographic texture in Zircaloy-2

Energy Technology Data Exchange (ETDEWEB)

Ballinger, R.G. (Massachusetts Inst. of Tech., Cambridge (USA)); Lucas, G.E. (California Univ., Santa Barbara (USA)); Pelloux, R.M. (Massachusetts Inst. of Tech., Cambridge (USA). Dept. of Materials Science and Engineering)

1984-09-01

The evolution of crystallographic texture during plastic deformation was investigated in Zircaloy-2 using X-ray and metallographic techniques. Inverse pole figures, the resolved fraction of basal poles, and the volume fraction of twinned material, were determined as a function of plastic strain for several strain paths and initial textures at 298 K and 623 K. Incremental transverse platic strain ratios (R) were measured as a function of plastic strain. Texture rotation occurs early in the deformation process, after as little as 1.5% plastic strain. For compressive plastic strains, the resolved fraction of basal poles increases in the direction parallel to the strain axis. For tensile plastic strains, the resolved fraction of basal poles decreases in the direction parallel to the strain axis. The rate of change of the resolved fraction of basal poles with plastic strain is a function of the initial resolved fraction of basal poles. The texture rotation can be explained by considering the operating of the principal tensile twinning systems, (10anti 12), .

Plasticity theory

CERN Document Server

Lubliner, Jacob

2008-01-01

The aim of Plasticity Theory is to provide a comprehensive introduction to the contemporary state of knowledge in basic plasticity theory and to its applications. It treats several areas not commonly found between the covers of a single book: the physics of plasticity, constitutive theory, dynamic plasticity, large-deformation plasticity, and numerical methods, in addition to a representative survey of problems treated by classical methods, such as elastic-plastic problems, plane plastic flow, and limit analysis; the problem discussed come from areas of interest to mechanical, structural, and

Technetium in chemistry and nuclear medicine

International Nuclear Information System (INIS)

Deutsch, E.; Nicolini, M.; Wagner, H.N.

1983-01-01

This volume explores the potential of technetium radiopharmaceuticals in clinical nuclear medicine. The authors examine the capabilities of synthetic inorganic chemists to synthesize technetium radiopharmaceuticals and the specific requirements of the nuclear medicine practitioner. Sections cover the chemistry of technetium, the production of radiopharmaceuticals labeled with technetium, and the use of technetium radiopharmaceuticals in nuclear medicine

Microbial colonization and degradation of polyethylene and biodegradable plastic bags in temperate fine-grained organic-rich marine sediments.

Science.gov (United States)

Nauendorf, Alice; Krause, Stefan; Bigalke, Nikolaus K; Gorb, Elena V; Gorb, Stanislav N; Haeckel, Matthias; Wahl, Martin; Treude, Tina

2016-02-15

To date, the longevity of plastic litter at the sea floor is poorly constrained. The present study compares colonization and biodegradation of plastic bags by aerobic and anaerobic benthic microbes in temperate fine-grained organic-rich marine sediments. Samples of polyethylene and biodegradable plastic carrier bags were incubated in natural oxic and anoxic sediments from Eckernförde Bay (Western Baltic Sea) for 98 days. Analyses included (1) microbial colonization rates on the bags, (2) examination of the surface structure, wettability, and chemistry, and (3) mass loss of the samples during incubation. On average, biodegradable plastic bags were colonized five times higher by aerobic and eight times higher by anaerobic microbes than polyethylene bags. Both types of bags showed no sign of biodegradation during this study. Therefore, marine sediment in temperate coastal zones may represent a long-term sink for plastic litter and also supposedly compostable material. Copyright © 2016 Elsevier Ltd. All rights reserved.

Regioregular narrow-bandgap-conjugated polymers for plastic electronics

Science.gov (United States)

Ying, Lei; Huang, Fei; Bazan, Guillermo C.

2017-03-01

Progress in the molecular design and processing protocols of semiconducting polymers has opened significant opportunities for the fabrication of low-cost plastic electronic devices. Recent studies indicate that field-effect transistors and organic solar cells fabricated using narrow-bandgap regioregular polymers with translational symmetries in the direction of the backbone vector often outperform those containing analogous regiorandom polymers. This review addresses the cutting edge of regioregularity chemistry, in particular how to control the spatial distribution in the molecular structures and how this order translates to more ordered bulk morphologies. The effect of regioregularity on charge transport and photovoltaic properties is also outlined.

Chemical Remediation of Nickel(II) Waste: A Laboratory Experiment for General Chemistry Students

Science.gov (United States)

Corcoran, K. Blake; Rood, Brian E.; Trogden, Bridget G.

2011-01-01

This project involved developing a method to remediate large quantities of aqueous waste from a general chemistry laboratory experiment. Aqueous Ni(II) waste from a general chemistry laboratory experiment was converted into solid nickel hydroxide hydrate with a substantial decrease in waste volume. The remediation method was developed for a…

Numerical studies of temperature effect on the extrusion fracture and swell of plastic micro-pipe

Science.gov (United States)

Ren, Zhong; Huang, Xingyuan; Xiong, Zhihua

2018-03-01

Temperature is a key factor that impacts extrusion forming quality of plastic micro-pipe. In this study, the effect of temperature on extrusion fracture and swell of plastic micro-pipe was investigated by numerical method. Under a certain of the melt’s flow volume, the extrusion pattern, extrusion swelling ratio of melt are obtained under different temperatures. Results show that the extrusion swelling ratio of plastic micro-pipe decreases with increasing of temperature. In order to study the reason of temperature effect, the physical distributions of plastic micro-pipe are gotten. Numerical results show that the viscosity, pressure, stress value of melt are all decreased with the increasing of temperature, which leads to decrease the extrusion swell and fracture phenomenon for the plastic micro-pipe.

Structure vs chemistry: friction and wear of Pt-based metallic surfaces.

Science.gov (United States)

Caron, A; Louzguine-Luzguin, D V; Bennewitz, R

2013-11-13

In comparison of a Pt57.5Cu14.7Ni5.3P22.5 metallic glass with a Pt(111) single crystal we find that wearless friction is determined by chemistry through bond formation alloying, while wear is determined by structure through plasticity mechanisms. In the wearless regime, friction is affected by the chemical composition of the counter body and involves the formation of a liquid-like neck and interfacial alloying. The wear behavior of Pt-based metallic surfaces is determined by their structural properties and corresponding mechanisms for plastic deformation. In the case of Pt(111) wear occurs by dislocation-mediated homogeneous plastic deformation. In contrast the wear of Pt57.5Cu14.7Ni5.3P22.5 metallic glass occurs through localized plastic deformation in shear bands that merge together in a single shear zone above a critical load and corresponds to the shear softening of metallic glasses. These results open a new route in the control of friction and wear of metals and are relevant for the development of self-lubricated and wear-resistant mechanical devices.

Large Volume, Behaviorally-relevant Illumination for Optogenetics in Non-human Primates.

Science.gov (United States)

Acker, Leah C; Pino, Erica N; Boyden, Edward S; Desimone, Robert

2017-10-03

This protocol describes a large-volume illuminator, which was developed for optogenetic manipulations in the non-human primate brain. The illuminator is a modified plastic optical fiber with etched tip, such that the light emitting surface area is > 100x that of a conventional fiber. In addition to describing the construction of the large-volume illuminator, this protocol details the quality-control calibration used to ensure even light distribution. Further, this protocol describes techniques for inserting and removing the large volume illuminator. Both superficial and deep structures may be illuminated. This large volume illuminator does not need to be physically coupled to an electrode, and because the illuminator is made of plastic, not glass, it will simply bend in circumstances when traditional optical fibers would shatter. Because this illuminator delivers light over behaviorally-relevant tissue volumes (≈ 10 mm 3 ) with no greater penetration damage than a conventional optical fiber, it facilitates behavioral studies using optogenetics in non-human primates.

Structural Chemistry of Human RNA Methyltransferases.

Science.gov (United States)

Schapira, Matthieu

2016-03-18

RNA methyltransferases (RNMTs) play important roles in RNA stability, splicing, and epigenetic mechanisms. They constitute a promising target class that is underexplored by the medicinal chemistry community. Information of relevance to drug design can be extracted from the rich structural coverage of human RNMTs. In this work, the structural chemistry of this protein family is analyzed in depth. Unlike most methyltransferases, RNMTs generally feature a substrate-binding site that is largely open on the cofactor-binding pocket, favoring the design of bisubstrate inhibitors. Substrate purine or pyrimidines are often sandwiched between hydrophobic walls that can accommodate planar ring systems. When the substrate base is laying on a shallow surface, a 5' flanking base is sometimes anchored in a druggable cavity. The cofactor-binding site is structurally more diverse than in protein methyltransferases and more druggable in SPOUT than in Rossman-fold enzymes. Finally, conformational plasticity observed both at the substrate and cofactor binding sites may be a challenge for structure-based drug design. The landscape drawn here may inform ongoing efforts toward the discovery of the first human RNMT inhibitors.

New plastic recycling technology | Science Inventory | US EPA

Science.gov (United States)

Greater than 60% of the total plastic content of municipal solid waste is comprised of polyolefins (high-density, low-density, and linear polyethylene and polypropylene. Polyethylene (PE) is the largest-volume component but presents a challenge due to the absence of low-energy degradation processes. This news column provides a digest of recent technical reports relating to clean technology and environmental policy,

Oil sorbents from plastic wastes and polymers: A review.

Science.gov (United States)

Saleem, Junaid; Adil Riaz, Muhammad; Gordon, McKay

2018-01-05

A large volume of the waste produced across the world is composed of polymers from plastic wastes such as polyethylene (HDPE or LDPE), polypropylene (PP), and polyethylene terephthalate (PET) amongst others. For years, environmentalists have been looking for various ways to overcome the problems of such large quantities of plastic wastes being disposed of into landfill sites. On the other hand, the usage of synthetic polymers as oil sorbents in particular, polyolefins, including polypropylene (PP) and polyethylene (PE) have been reported. In recent years, the idea of using plastic wastes as the feed for the production of oil sorbents has gained momentum. However, the studies undertaking such feasibility are rather scattered. This review paper is the first of its kind reporting, compiling and reviewing these various processes. The production of an oil sorbent from plastic wastes is being seen to be satisfactorily achievable through a variety of methods Nevertheless, much work needs to be done regarding further investigation of the numerous parameters influencing production yields and sorbent qualities. For example, differences in results are seen due to varying operating conditions, experimental setups, and virgin or waste plastics being used as feeds. The field of producing oil sorbents from plastic wastes is still very open for further research, and seems to be a promising route for both waste reduction, and the synthesis of value-added products such as oil sorbents. In this review, the research related to the production of various oil sorbents based on plastics (plastic waste and virgin polymer) has been discussed. Further oil sorbent efficiency in terms of oil sorption capacity has been described. Copyright © 2017 Elsevier B.V. All rights reserved.

Ocean acidification challenges copepod phenotypic plasticity

Directory of Open Access Journals (Sweden)

A. Vehmaa

2016-11-01

Full Text Available Ocean acidification is challenging phenotypic plasticity of individuals and populations. Calanoid copepods (zooplankton are shown to be fairly plastic against altered pH conditions, and laboratory studies indicate that transgenerational effects are one mechanism behind this plasticity. We studied phenotypic plasticity of the copepod Acartia sp. in the course of a pelagic, large-volume mesocosm study that was conducted to investigate ecosystem and biogeochemical responses to ocean acidification. We measured copepod egg production rate, egg-hatching success, adult female size and adult female antioxidant capacity (ORAC as a function of acidification (fCO2  ∼  365–1231 µatm and as a function of quantity and quality of their diet. We used an egg transplant experiment to reveal whether transgenerational effects can alleviate the possible negative effects of ocean acidification on offspring development. We found significant negative effects of ocean acidification on adult female size. In addition, we found signs of a possible threshold at high fCO2, above which adaptive maternal effects cannot alleviate the negative effects of acidification on egg-hatching and nauplii development. We did not find support for the hypothesis that insufficient food quantity (total particulate carbon < 55 µm or quality (C : N weakens the transgenerational effects. However, females with high-ORAC-produced eggs with high hatching success. Overall, these results indicate that Acartia sp. could be affected by projected near-future CO2 levels.

Ocean acidification challenges copepod reproductive plasticity

Science.gov (United States)

Vehmaa, A.; Almén, A.-K.; Brutemark, A.; Paul, A.; Riebesell, U.; Furuhagen, S.; Engström-Öst, J.

2015-11-01

Ocean acidification is challenging phenotypic plasticity of individuals and populations. Calanoid copepods (zooplankton) are shown to be fairly plastic against altered pH conditions, and laboratory studies indicate that transgenerational effects are one mechanism behind this plasticity. We studied phenotypic plasticity of the copepod Acartia bifilosa in the course of a pelagic, large-volume mesocosm study that was conducted to investigate ecosystem and biogeochemical responses to ocean acidification. We measured copepod egg production rate, egg hatching success, adult female size and adult female antioxidant capacity (ORAC) as a function of acidification (fCO2 ~ 365-1231 μatm), and as a function of quantity and quality of their diet. We used an egg transplant experiment to reveal if transgenerational effects can alleviate the possible negative effects of ocean acidification on offspring development. We found significant negative effects of ocean acidification on adult female copepod size and egg hatching success. In addition, we found a threshold of fCO2 concentration (~ 1000 μatm), above which adaptive maternal effects cannot alleviate the negative effects of acidification on egg hatching and nauplii development. We did not find support for the hypothesis that insufficient food quantity (total particulate carbon ~ 55 μm) or quality (C : N) weakens the transgenerational effects. However, females with high ORAC produced eggs with high hatching success. Overall, these results indicate that A. bifilosa could be affected by projected near future CO2 levels.

Magical Engineering Plastic

Energy Technology Data Exchange (ETDEWEB)

Kim, Gwang Ung

1988-01-15

This book introduces engineering plastic about advantage of engineering plastic, plastic material from processing method, plastic shock, plastic until now, background of making of engineering plastic, wonderful engineering plastic science such as a high molecule and molecule, classification of high molecule, difference between metal and high molecule, heat and high molecule materials, and property of surface, engineering plastic of dream like from linseed oil to aramid, small dictionary of engineering plastic.

Magical Engineering Plastic

International Nuclear Information System (INIS)

Kim, Gwang Ung

1988-01-01

This book introduces engineering plastic about advantage of engineering plastic, plastic material from processing method, plastic shock, plastic until now, background of making of engineering plastic, wonderful engineering plastic science such as a high molecule and molecule, classification of high molecule, difference between metal and high molecule, heat and high molecule materials, and property of surface, engineering plastic of dream like from linseed oil to aramid, small dictionary of engineering plastic.

Proceedings of the Scientific Meeting on Application of Isotopes and Radiation: Book 2. Chemistry, Environment, Radiation Process, And Industry

Energy Technology Data Exchange (ETDEWEB)

Suhadi, F; Sisworo, E L; Maha, M; Ismachin, M; Hilmy, N; Sumatra, M; Mugiono,; Wandowo,; Soebianto, Y S [Center for Application of Isotopes and Radiation, National Atomic Energy Agency, Jakarta (Indonesia)

1998-07-01

The aim of the 10th Meeting of the Isotope and Radiation Application is to disseminate the result of research on application of nuclear techniques on agriculture, animal, biology, chemistry, environment, radiation process and industry. The meeting was held in Jakarta, 18-19 February 1998, and there were 6 invited papers and 52 papers indexed individually. This proceeding is divided by two volumes. Volume I and volume II consists of agriculture, animal, biology and chemistry, environment, radiation process and industry, respectively.(ID)

Proceedings of the Scientific Meeting on Application of Isotopes and Radiation: Book 2. Chemistry, Environment, Radiation Process, And Industry

International Nuclear Information System (INIS)

Suhadi, F.; Sisworo, E.L.; Maha, M.; Ismachin, M.; Hilmy, N.; Sumatra, M.; Mugiono; Wandowo; Soebianto, Y.S.

1998-01-01

The aim of the 10th Meeting of the Isotope and Radiation Application is to disseminate the result of research on application of nuclear techniques on agriculture, animal, biology, chemistry, environment, radiation process and industry. The meeting was held in Jakarta, 18-19 February 1998, and there were 6 invited papers and 52 papers indexed individually. This proceeding is divided by two volumes. Volume I and volume II consists of agriculture, animal, biology and chemistry, environment, radiation process and industry, respectively.(ID)

Remarks on theoretical hot-atom chemistry

International Nuclear Information System (INIS)

Inokuti, Mitio

1993-01-01

The publication of the 'Handbook of Hot Atom Chemistry', following the earlier volume 'Recent Trend and Application', was a major milestone in physical chemistry. Theoretical treatments of hot atom chemistry must address two classes of problems. The first class concerns the individual collisions of hot atoms with other atoms or molecules. The second class concerns the description of the consequences of the many collisions of hot atoms and their chemical environment. Most of the remarks pertain to the problems of the first class. The central issue is the adiabaticity of nuclear motions versus electronic motions. To be precise, any atomic core motion should be mentioned rather than pure nuclear motion, because tightly bound core electrons are largely irrelevant to the chemistry. When nuclear motions are sufficiently slow, or for other reasons that can be regarded as adiabatic, the collision problem is basically straightforward, therefore, interatomic and intermolecular forces can be assumed, and their consequences for nuclear motions are calculable in principle. In the case of non-adiabaticity being important, much more difficult problems arise, and it is briefly discussed, and the work by Phelps is cited. (K.I.)

International policies to reduce plastic marine pollution from single-use plastics (plastic bags and microbeads): A review.

Science.gov (United States)

Xanthos, Dirk; Walker, Tony R

2017-05-15

Marine plastic pollution has been a growing concern for decades. Single-use plastics (plastic bags and microbeads) are a significant source of this pollution. Although research outlining environmental, social, and economic impacts of marine plastic pollution is growing, few studies have examined policy and legislative tools to reduce plastic pollution, particularly single-use plastics (plastic bags and microbeads). This paper reviews current international market-based strategies and policies to reduce plastic bags and microbeads. While policies to reduce microbeads began in 2014, interventions for plastic bags began much earlier in 1991. However, few studies have documented or measured the effectiveness of these reduction strategies. Recommendations to further reduce single-use plastic marine pollution include: (i) research to evaluate effectiveness of bans and levies to ensure policies are having positive impacts on marine environments; and (ii) education and outreach to reduce consumption of plastic bags and microbeads at source. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of Microstructure Evolution on the Overall Response of Porous-Plastic Solids

Directory of Open Access Journals (Sweden)

Stefano Mariani

2010-02-01

Full Text Available Ductile fracture is the macroscopic result of a micromechanical process consisting in void nucleation and growth to coalescence. While growing in size, voids also evolve in shape because of the non-uniform deformation field in the surrounding material; this shape evolution is either disregarded or approximately accounted for by constitutive laws for porous-plastic solids. To assess the effect of void distortion on the overall properties of a porous-plastic material prior to any coalescence-dominated event, we here present a micromechanical study in which the void-containing material is treated as a two-phase (matrix and inclusion composite. A cylindrical representative volume element (RVE, featuring elliptic cross-section and containing a coaxial and confocal elliptic cylindrical cavity, is considered. In case of a matrix obeying J2 flow theory of plasticity, the overall yield domain and the evolution laws for the volume fraction and aspect ratio of the void are obtained. Under assigned strain histories, these theoretical findings are then compared to finite element unit-cell simulations, in order to assess the capability of the proposed results to track microstructure evolution. The improvements with respect to the customarily adopted Gurson’s model are also discussed.

Development of thermo-plastic heating and compaction facility

International Nuclear Information System (INIS)

Ko, Dae Hak; Lim, Suk Nam

1998-01-01

Low- and intermediate-level radioactive wastes consist of spent resin, spent filter, concentrated waste and dry active waste(DAW) and they are solidified or packaged into drums or high integrated containers(HICs). DAWs occupy 50 percent of all low- and intermediate-level radioactive wastes generated from nuclear power plants in Korea. Incinerable wastes in the DAWs are about 60 percent. Therefore, it is very important for us to reduce the volume of incinerable wastes in DAWs. Experience of supercompaction turned out that thermo-plastic wastes have a swelling effect after supercompaction process due to their repulsive power. And the thermo-plastic heating and compaction facility has been developed by KEPCO. In conclusion, heating and compaction facility can reduce the volume of DAWs as well as upgrade the quality of treated wastes, because the swelling effect by repulsive power after compaction is removed, final wastes form the shape of block and they have no free-standing water in the wastes. Plan for practical use is that this facility will be installed in other nuclear power plants in Korea in 1999. (Cho, G. S.). 1 tab., 2 figs

Promise and Limitations of Big Data Research in Plastic Surgery.

Science.gov (United States)

Zhu, Victor Zhang; Tuggle, Charles Thompson; Au, Alexander Francis

2016-04-01

The use of "Big Data" in plastic surgery outcomes research has increased dramatically in the last 5 years. This article addresses some of the benefits and limitations of such research. This is a narrative review of large database studies in plastic surgery. There are several benefits to database research as compared with traditional forms of research, such as randomized controlled studies and cohort studies. These include the ease in patient recruitment, reduction in selection bias, and increased generalizability. As such, the types of outcomes research that are particularly suited for database studies include determination of geographic variations in practice, volume outcome analysis, evaluation of how sociodemographic factors affect access to health care, and trend analyses over time. The limitations of database research include data which are limited only to what was captured in the database, high power which can cause clinically insignificant differences to achieve statistical significance, and fishing which can lead to increased type I errors. The National Surgical Quality Improvement Project is an important general surgery database that may be useful for plastic surgeons because it is validated and has a large number of patients after over a decade of collecting data. The Tracking Operations and Outcomes for Plastic Surgeons Program is a newer database specific to plastic surgery. Databases are a powerful tool for plastic surgery outcomes research. It is critically important to understand their benefits and limitations when designing research projects or interpreting studies whose data have been drawn from them. For plastic surgeons, National Surgical Quality Improvement Project has a greater number of publications, but Tracking Operations and Outcomes for Plastic Surgeons Program is the most applicable database for plastic surgery research.

Plastics disassembly versus bulk recycling: engineering design for end-of-life electronics resource recovery.

Science.gov (United States)

Rios, Pedro; Stuart, Julie Ann; Grant, Ed

2003-12-01

Annual plastic flows through the business and consumer electronics manufacturing supply chain include nearly 3 billion lb of high-value engineering plastics derived from petroleum. The recovery of resource value from this stream presents critical challenges in areas of materials identification and recycling process design that demand new green engineering technologies applied together with life cycle assessment and ecological supply chain analysis to create viable plastics-to-plastics supply cycles. The sustainable recovery of potentially high-value engineering plastics streams requires that recyclers either avoid mixing plastic parts or purify later by separating smaller plastic pieces created in volume reduction (shredding) steps. Identification and separation constitute significant barriers in the plastics-to-plastics recycling value proposition. In the present work, we develop a model that accepts randomly arriving electronic products to study scenarios by which a recycler might identify and separate high-value engineering plastics as well as metals. Using discrete eventsimulation,we compare current mixed plastics recovery with spectrochemical plastic resin identification and subsequent sorting. Our results show that limited disassembly with whole-part identification can produce substantial yields in separated streams of recovered engineering thermoplastics. We find that disassembly with identification does not constitute a bottleneck, but rather, with relatively few workers, can be configured to pull the process and thus decrease maximum staging space requirements.

Characterization of the surface physico-chemistry of plasticized PVC used in blood bag and infusion tubing.

Science.gov (United States)

Al Salloum, H; Saunier, J; Dazzi, A; Vigneron, J; Etcheberry, A; Marlière, C; Aymes-Chodur, C; Herry, J M; Bernard, M; Jubeli, E; Yagoubi, N

2017-06-01

Commercial infusion tubing and blood storage devices (tubing, blood and platelets bags) made of plasticized PVC were analyzed by spectroscopic, chromatographic and microscopic techniques in order to identify and quantify the additives added to the polymer (lubricants, thermal stabilizers, plasticizers) and to put into evidence their blooming onto the surface of the devices. For all the samples, deposits were observed on the surface but with different kinds of morphologies. Ethylene bis amide lubricant and metallic stearate stabilizers were implicated in the formation of these layers. In contact with aqueous media, these insoluble deposits were damaged, suggesting a possible particulate contamination of the infused solutions. Copyright © 2017 Elsevier B.V. All rights reserved.

Separation properties of aluminium-plastic laminates in post-consumer Tetra Pak with mixed organic solvent.

Science.gov (United States)

Zhang, S F; Zhang, L L; Luo, K; Sun, Z X; Mei, X X

2014-04-01

The separation properties of the aluminium-plastic laminates in postconsumer Tetra Pak structure were studied in this present work. The organic solvent blend of benzene-ethyl alcohol-water was used as the separation reagent. Then triangle coordinate figure analysis was taken to optimize the volume proportion of various components in the separating agent and separation process. And the separation temperature of aluminium-plastic laminates was determined by the separation time, efficiency, and total mass loss of products. The results show that cost-efficient separations perform best with low usage of solvents at certain temperatures, for certain times, and within a certain range of volume proportions of the three components in the solvent agent. It is also found that similar solubility parameters of solvents and polyethylene adhesives (range 26.06-34.85) are a key factor for the separation of the aluminium-plastic laminates. Such multisolvent processes based on the combined-system concept will be vital to applications in the recycling industry.

Plastic solidification system at Hamaoka Nuclear Power Station

International Nuclear Information System (INIS)

Okajima, Hiroyuki; Iokibe, Hiroyuki; Tsukiyama, Shigeru; Suzuki, Michio; Yamaguchi, Masato

1987-01-01

In Unit 1 and 2 of the Hamaoka Nuclear Power Station, radioactive waste was previously solidified in cement. By this method, the quantity of waste thus treated is relatively small, resulting in large number of the solidified drums. In order to solve this problem, the solidification facility using a thermosetting resin was employed, which is in operation since January 1986 for Unit 1, 2 and 3. As compared with the cement solidification, the solidified volume of concentrated liquid is about 1/12 and of spent-resin slurry is about 1/4 in plastic solidification. The following are described: course leading to the employment, the plastic solidification facility, features of the facility, operation results so far with the facility, etc. (Mori, K.)

The effect of plastic strain on the evolution of crystallographic texture in Zircaloy-2

International Nuclear Information System (INIS)

Ballinger, R.G.; Lucas, G.E.; Pelloux, R.M.

1984-01-01

The evolution of crystallographic texture during plastic deformation was investigated in Zircaloy-2 using X-ray and metallographic techniques. Inverse pole figures, the resolved fraction of basal poles, and the volume fraction of twinned material, were determined as a function of plastic strain for several strain paths and initial textures at 298 K and 623 K. Incremental transverse platic strain ratios (R) were measured as a function of plastic strain. Texture rotation occurs early in the deformation process, after as little as 1.5% plastic strain. For compressive plastic strains, the resolved fraction of basal poles increases in the direction parallel to the strain axis. For tensile plastic strains, the resolved fraction of basal poles decreases in the direction parallel to the strain axis. The rate of change of the resolved fraction of basal poles with plastic strain is a function of the initial resolved fraction of basal poles. The texture rotation can be explained by considering the operating of the principal tensile twinning systems, [10anti 12], . (orig.)

The effect of plastic strain on the evolution of crystallographic texture in Zircaloy-2

Science.gov (United States)

Ballinger, R. G.; Lucas, G. E.; Pelloux, R. M.

1984-09-01

The evolution of crystallographic texture during plastic deformation was investigated in Zircaloy-2 using X-ray and metallographic techniques. Inverse pole figures, the resolved fraction of basal poles, and the volume fraction of twinned material, were determined as a function of plastic strain for several strain paths and initial textures at 298 K and 623 K. Incremental transverse platic strain ratios ( R) were mesured as a function of plastic strain. Texture rotation occurs early in the deformation process, after as little as 1.5% plastic strain. For compressive plastic strains, the resolved fraction of basal poles increases in the direction parallel to the strain axis. For tensile plastic strains, the resolved fraction of basal poles decreases in the direction parallel to the strain axis. The rate of change of the resolved fraction of basal poles with plastic strain is a function of the initial resolved fraction of basal poles. The texture rotation can be explained by considering the operation of the principal tensile twinning systems, {101¯2}.

The Plastic Surgery Hand Curriculum.

Science.gov (United States)

Silvestre, Jason; Levin, L Scott; Serletti, Joseph M; Chang, Benjamin

2015-12-01

Designing an effective hand rotation for plastic surgery residents is difficult. The authors address this limitation by elucidating the critical components of the hand curriculum during plastic surgery residency. Hand questions on the Plastic Surgery In-Service Training Exam for six consecutive years (2008 to 2013) were characterized by presence of imaging, vignette setting, question taxonomy, answer domain, anatomy, and topic. Answer references were quantified by source and year of publication. Two hundred sixty-six questions were related to hand surgery (22.7 percent of all questions; 44.3 per year) and 61 were accompanied by an image (22.9 percent). Vignettes tended to be clinic- (50.0 percent) and emergency room-based (35.3 percent) (p < 0.001). Questions required decision-making (60.5 percent) over interpretation (25.9 percent) and recall skills (13.5 percent) (p < 0.001). Answers focused on interventions (57.5 percent) over anatomy/pathology (25.2 percent) and diagnoses (17.3 percent) (p < 0.001). Nearly half of the questions focused on the digits. The highest yield topics were trauma (35.3 percent), reconstruction (24.4 percent), and aesthetic and functional problems (14.2 percent). The Journal of Hand Surgery (American volume) (20.5 percent) and Plastic and Reconstructive Surgery (18.0 percent) were the most-cited journals, and the median publication lag was 7 years. Green's Operative Hand Surgery was the most-referenced textbook (41.8 percent). These results will enable trainees to study hand surgery topics with greater efficiency. Faculty can use these results to ensure that tested topics are covered during residency training. Thus, a benchmark is established to improve didactic, clinical, and operative experiences in hand surgery.

Analysis of References on the Plastic Surgery In-Service Training Exam.

Science.gov (United States)

Silvestre, Jason; Zhang, Alicia; Lin, Samuel J

2016-06-01

The Plastic Surgery In-Service Training Exam is a knowledge assessment tool widely used during plastic surgery training in the United States. This study analyzed literature supporting correct answer choices to determine highest yield sources, journal publication lag, and journal impact factors. Digital syllabi of 10 consecutive Plastic Surgery In-Service Training Exam administrations (2006 to 2015) were reviewed. The most-referenced articles, journals, and textbooks were determined. Mean journal impact factor and publication lag were calculated and differences were elucidated by section. Two thousand questions and 5386 references were analyzed. From 2006 to 2015, the percentage of journal citations increased, whereas textbook references decreased (p < 0.001). Plastic and Reconstructive Surgery was cited with greatest frequency (38.5 percent), followed by Clinics in Plastic Surgery (5.6 percent), Journal of Hand Surgery (American volume) (5.1 percent), and Annals of Plastic Surgery (3.8 percent). There was a trend toward less publication lag over the study period (p = 0.05), with a mean publication lag of 9.1 ± 9.0 years for all journal articles. Mean journal impact factor was 2.3 ± 4.3 and lowest for the hand and lower extremity section (1.7 ± 2.8; p < 0.001). The highest yield textbooks were elucidated by section. Plastic surgery faculty and residents may use these data to facilitate knowledge acquisition during residency.

Development of Process for Disposal of Plastic Waste Using Plasma Pyrolysis Technology and Option for Energy Recovery

Czech Academy of Sciences Publication Activity Database

Punčochář, Miroslav; Ruj, B.; Chatterj, P.K.

2012-01-01

Roč. 42, SI (2012), s. 420-430 E-ISSN 1877-7058. [International Congress of Chemical and Process Engineering CHISA 2012 and 15th Conference PRES 2012 /20./. Prague, 25.08.2012-29.08.2012] Institutional support: RVO:67985858 Keywords : plastic waste * plasma pyrolysis * syngas Subject RIV: CI - Industrial Chemistry, Chemical Engineering

Environmental status of the Lake Michigan region. Volume 3. Chemistry of Lake Michigan

Energy Technology Data Exchange (ETDEWEB)

Torrey, M S

1976-05-01

The report is a synoptic review of data collected over the past twenty years on the chemistry of Lake Michigan. Changes in water quality and sediment chemistry, attributable to cultural and natural influences, are considered in relation to interacting processes and factors controlling the distribution and concentration of chemical substances within the Lake. Temperature, light, and mixing processes are among the important natural influences that affect nutrient cycling, dispersal of pollutants, and fate of materials entering the Lake. Characterization of inshore-offshore and longitudinal differences in chemical concentrations and sediment chemistry for the main body of the Lake is supplemented by discussion of specific areas such as Green Bay and Grand Traverse Bay. Residues, specific conductance, dissolved oxygen, major and trace nutrients, and contaminants are described in the following context: biological essentiality and/or toxicity, sources to the Lake, concentrations in the water column and sediments, chemical forms, seasonal variations and variation with depth. A summary of existing water quality standards, statutes, and criteria applicable to Lake Michigan is appended.

The J-integral concept for elastic-plastic material behavior

International Nuclear Information System (INIS)

Schmitt, W.; Kienzler, R.

1987-03-01

A simple analytical extension of the J integral has been presented which extends the J concept to apply for materials described by an incremental theory of plasticity. The stress work density replacing the strain energy density is load-history dependent. The J integral may be made path independent by virtue of an additional volume integral and may be understood as work dissipation rate. The discussion of the consequences for the applicability of the J concept to describe fracture processes showed that validity criteria proposed in the standards are not sufficient to yield configuration-independent J-resistance curves. However, a possibility is sketched to assess those structure-dependent resistance curves based on plastic-collapse considerations. With 6 figs., 33 refs

Handbook on the physics and chemistry of rare earths: Volume 17

International Nuclear Information System (INIS)

Gschneidner, K.A. Jr; Eyring, L.; Choppin, G.R.; Lander, G.H.

1993-10-01

This volume of the handbook is the first of a three volume set of reviews devoted to the interrelationships, similarities, differences and contrasts of the lanthanide and actinide series of elements. The volume contains eight chapters (numbered 110-117) concerned with some of the physical aspects of lanthanide and actinide series. The first three chapters are theoretical in nature and the last five are more heavily oriented towards experimental studies

Mathematical model of a current of two plastic environments in the forming channel extruders at coextrusion

Directory of Open Access Journals (Sweden)

V. N. Vasilenko

2012-01-01

Full Text Available On the basis of the classical equations of an isothermal pressure head current of two rheology the various not mixing up viscou- plastic environments in the cylindrical channel, Ostvald-de-Vil submitting to the law, the model of a current of two viscous-plastic environments in the moulding channel extruder is synthesised at co-extrusion on which basis the technique of a choice of diameter of a dosing out branch pipe on the demanded value of the ratio of volume expenditures of two viscous-plastic environments (extrudat and stuffings is offered.

BIODEGRADABLE PLASTICS FROM A MIXTURE OF LOW DENSITY POLYETHYLENE (LDPE AND CASSAVA STARCH WITH THE ADDITION OF ACRYLIC ACID

Directory of Open Access Journals (Sweden)

Susilawati Susilawati

2013-05-01

Full Text Available A research of preparation biodegradable plastics, from LDPE and cassava starch mixture with the addition of acrylic acid, had been conducted. This research purpose to  studied compatibility properties of the material and percent weight loss during the biodegradation test. Optimum weight loss (59,26% was showed after 60 days witches LDPE and starch composition ratio 6 : 4 (w/w  while tensile strength  equal to 0,38 Kgf/mm2.  SEM characterization showed that biodegradation has occurred by  formation of hole in the biodegradable plastic surface. DTA test gave Tg = 130 °C, Tm = 230 °C and Td = 370-450 °C while FT-IR analysis showed that the biodegradable plastics have a chemistry interaction.

Micro-thermomechanical constitutive model of transformation induced plasticity and its application on armour steel

Energy Technology Data Exchange (ETDEWEB)

Sun, C.Y. [School of Mechanical Engineering, University of Science and Technology Beijing, Beijing 100083 (China)], E-mail: suncy@me.ustb.edu.cn; Fang, G.; Lei, L.P.; Zeng, P. [Key Laboratory of Advanced Materials Processing Technology, Ministry of Education, Department of Mechanical Engineering, Tsinghua University, Beijing 100084 (China)

2009-01-15

Based on the crystallographic theory of martensitic transformation and internal variable constitutive theory, a micromechanical constitutive model of martensitic transformation induced plasticity was developed. Plastic strains of product and parent phases as well as the volume fraction of each martensitic variant were considered as internal variables describing the microstructure evolution. The plasticity flow both in austenite and martensitic variants domain is described by J{sub 2} flow theory. The thermodynamic driving force acting on these internal variables was obtained through the determination of the intrinsic dissipation due to plastic flow and the growth of martensitic domains. The evolution laws of the internal variables are derived, furthermore macroscopic response due to the change of internal variables is obtained. Thermomechanical behavior of armour steel under uniaxial loading was tested which showed a good agreement with experimental results.

Micro-thermomechanical constitutive model of transformation induced plasticity and its application on armour steel

International Nuclear Information System (INIS)

Sun, C.Y.; Fang, G.; Lei, L.P.; Zeng, P.

2009-01-01

Based on the crystallographic theory of martensitic transformation and internal variable constitutive theory, a micromechanical constitutive model of martensitic transformation induced plasticity was developed. Plastic strains of product and parent phases as well as the volume fraction of each martensitic variant were considered as internal variables describing the microstructure evolution. The plasticity flow both in austenite and martensitic variants domain is described by J 2 flow theory. The thermodynamic driving force acting on these internal variables was obtained through the determination of the intrinsic dissipation due to plastic flow and the growth of martensitic domains. The evolution laws of the internal variables are derived, furthermore macroscopic response due to the change of internal variables is obtained. Thermomechanical behavior of armour steel under uniaxial loading was tested which showed a good agreement with experimental results

Quantification of the free volume in Zr45.0Cu39.3Al7.0Ag8.7 bulk metallic glasses subjected to plastic deformation by calorimetric and dilatometric measurements

International Nuclear Information System (INIS)

Zhang Yue; Hahn, Horst

2009-01-01

Zr 45.0 Cu 39.3 Al 7.0 Ag 8.7 bulk metallic glasses (BMGs) were prepared using suction casting technique. Plastic deformations were carried out by cold rolling and high-pressure torsion (HPT). The absolute contents of free volume in the as-cast, preheated and deformed samples were determined by differential scanning calorimetry (DSC) and dilatometry using the free volume model (FVM). The parameters required in the FVM are experimentally determined to be b = 0.107, β = 642.1 kJ/mol, D * = 10.3 and T 0 = 496.9 K, respectively. The equilibrium free volume determined by these parameters is in good agreement with that calculated from previous enthalpy relaxation experiments, showing the reliability of the values of the parameters. It is found that the content of free volume in the as-cast sample is 0.533% with respect to the atomic volume of the BMG. The free volume in the HPT deformed sample is determined to be 0.672%, which is the largest among all the samples. The excess free volume introduced by cold rolling is found to increase with the deformation strain and show weak strain rate dependent behavior. Finally, attempts are made to simulate the experimental DSC curve using a bimolecular kinetics in the flow defect model. However, the result shows that the kinetics of free volume may be more complicated than as described as a bimolecular process.

Investigating the pore-water chemistry effects on the volume change behaviour of Boom clay

Science.gov (United States)

Deng, Y. F.; Cui, Y. J.; Tang, A. M.; Nguyen, X. P.; Li, X. L.; Van Geet, M.

The Essen site has been chosen as an alternative site for nuclear waste disposal in Belgium. The soil formation involved at this site is the same as at Mol site: Boom clay. However, owing to its geographical situation closer to the sea, Boom clay at Essen presents a pore water salinity 4-5 times higher than Boom clay at Mol. This study aims at studying the effects of pore water salinity on the hydro-mechanical behaviour of Boom clay. Specific oedometer cells were used allowing “flushing” the pore water in soil specimen by synthetic pore water or distilled water. The synthetic pore water used was prepared with the chemistry as that for the site water: 5.037 g/L for core Ess83 and 5.578 g/L for core Ess96. Mechanical loading was then carried out on the soil specimen after flushing. The results show that water salinity effect on the liquid limit is negligible. The saturation or pore water replacement under the in situ effective stress of 2.4 MPa does not induce significant volume change. For Ess83, hydro-mechanical behaviour was found to be slightly influenced by the water salinity; on the contrary, no obvious effect was identified on the hydro-mechanical behaviour of Ess96. This can be attributed to the higher smectite content in Ess83 than in Ess96.

Study of mortars with industrial residual plastic scales

OpenAIRE

Magariños, O. E.; Alderete, C. E.; Arias, L. E.; Lucca, M. E.

1998-01-01

This work proposes the utilization of industrial residues of PET (Polyethylene Terephtalate) as a partial substitute of arids (sand) in mortar making for construction components. Therefore, the environmental impact of large volumes of plastic of urban residues could be decreased. When PET scales were added to mortars in partial replacement of sand, lower unitary weight, acceptable absorption and resistances according to international specifications were achieved. Mortars with 66% of sand...

Microfluidics and nanofluidics handbook chemistry, physics, and life science principles

CERN Document Server

Mitra, Sushanta K

2011-01-01

The Microfluidics and Nanofluidics Handbook: Two-Volume Set comprehensively captures the cross-disciplinary breadth of the fields of micro- and nanofluidics, which encompass the biological sciences, chemistry, physics and engineering applications. To fill the knowledge gap between engineering and the basic sciences, the editors pulled together key individuals, well known in their respective areas, to author chapters that help graduate students, scientists, and practicing engineers understand the overall area of microfluidics and nanofluidics. Topics covered include Cell Lysis Techniques in Lab-on-a-Chip Technology Electrodics in Electrochemical Energy Conversion Systems: Microstructure and Pore-Scale Transport Microscale Gas Flow Dynamics and Molecular Models for Gas Flow and Heat Transfer Microscopic Hemorheology and Hemodynamics Covering physics and transport phenomena along with life sciences and related applications, Volume One: Chemistry, Physics, and Life Science Principles provides readers with the fun...

Safe Disposal of Medical and Plastic Waste and Energy Recovery Possibilities using Plasma Pyrolysis Technology

International Nuclear Information System (INIS)

Nema, S.K.; Mukherjee, S.

2010-01-01

Plasma pyrolysis and plasma gasification are emerging technologies that can provide complete solution to organic solid waste disposal. In these technologies plasma torch is used as a workhorse to convert electrical energy into heat energy. These technologies dispose the organic waste in an environment friendly manner. Thermal plasma provides extremely high temperature in oxygen free or controlled air environment which is required for pyrolysis or gasification reactions. Plasma based medical waste treatment is an extremely complex technology since it has to contend with extreme temperatures and corrosion-prone environment, complex pyro-chemistry resulting in toxic and dangerous products, if not controlled. In addition, one has to take care of complete combustion of pyrolyzed gases followed by efficient scrubbing to meet the emission standards set by US EPA and Central Pollution Control Board, India. In medical waste, high volume and low packing density waste with nonstandard composition consisting of a variety of plastics, organic material and liquids used to be present. The present paper describes the work carried out at Institute for Plasma Research, India, on plasma pyrolysis of (i) medical waste disposal and the results of emission measurement done at various locations in the system and (ii) energy recovery from cotton and plastic waste. The process and system development has been done in multiple steps. Different plasma pyrolysis models were made and each subsequent model was improved upon to meet stringent emission norms and to make the system energy efficient and user friendly. FCIPT, has successfully demonstrated up to 50 kg/ hr plasma pyrolysis systems and have installed plasma pyrolysis facilities at various locations in India . Plastic Waste disposal along with energy recovery in 15 kg/ hr model has also been developed and demonstrated at FCIPT. In future, this technology has great potential to dispose safely different waste streams such as biomass

Hydrogen-Induced Plastic Deformation in ZnO

Science.gov (United States)

Lukáč, F.; Čížek, J.; Vlček, M.; Procházka, I.; Anwand, W.; Brauer, G.; Traeger, F.; Rogalla, D.; Becker, H.-W.

In the present work hydrothermally grown ZnO single crystals covered with Pd over-layer were electrochemically loaded with hydrogen and the influence of hydrogen on ZnO micro structure was investigated by positron annihilation spectroscopy (PAS). Nuclear reaction analysis (NRA) was employed for determination of depth profile of hydrogen concentration in the sample. NRA measurements confirmed that a substantial amount of hydrogen was introduced into ZnO by electrochemical charging. The bulk hydrogen concentration in ZnO determined by NRA agrees well with the concentration estimated from the transported charge using the Faraday's law. Moreover, a subsurface region with enhanced hydrogen concentration was found in the loaded crystals. Slow positron implantation spectroscopy (SPIS) investigations of hydrogen-loaded crystal revealed enhanced concentration of defects in the subsurface region. This testifies hydrogen-induced plastic deformation of the loaded crystal. Absorbed hydrogen causes a significant lattice expansion. At low hydrogen concentrations this expansion is accommodated by elastic straining, but at higher concentrations hydrogen-induced stress exceeds the yield stress in ZnO and plastic deformation of the loaded crystal takes place. Enhanced hydrogen concentration detected in the subsurface region by NRA is, therefore, due to excess hydrogen trapped at open volume defects introduced by plastic deformation. Moreover, it was found that hydrogen-induced plastic deformation in the subsurface layer leads to typical surface modification: formation of hexagonal shape pyramids on the surface due to hydrogen-induced slip in the [0001] direction.

Experimental study of stress-induced localized transformation plastic zones in tetragonal zirconia polycrystalline ceramics

International Nuclear Information System (INIS)

Sun, Q.; Zhao, Z.; Chen, W.; Qing, X.; Xu, X.; Dai, F.

1994-01-01

Stress-induced martensitic transformation plastic zones in ceria-stabilized tetragonal zirconia polycrystalline ceramics (Ce-TZP), under loading conditions of uniaxial tension, compression, and three-point bending, are studied by experiments. The transformed monoclinic phase volume fraction distribution and the corresponding plastic strain distribution and the surface morphology (surface uplift) are measured by means of moire interferometry, Raman microprobe spectroscopy, and the surface measurement system. The experimental results from the above three kinds of specimens and methods consistently show that the stress-induced transformation at room temperature of the above specimen is not uniform within the transformation zone and that the plastic deformation is concentrated in some narrow band; i.e., macroscopic plastic flow localization proceeds during the initial stage of plastic deformation. Flow localization phenomena are all observed in uniaxial tension, compression, and three-point bending specimens. Some implications of the flow localization to the constitutive modeling and toughening of transforming thermoelastic polycrystalline ceramics are explored

Healing behavior of preexisting hydrogen micropores in aluminum alloys during plastic deformation

International Nuclear Information System (INIS)

Toda, H.; Minami, K.; Koyama, K.; Ichitani, K.; Kobayashi, M.; Uesugi, K.; Suzuki, Y.

2009-01-01

Synchrotron X-ray microtomography was used to observe the shrinkage and annihilation behaviors of hydrogen micropores in three dimensions during hot and cold plastic deformation of an Al-Mg alloy. Whether complete healing of micropores is achieved after plastic deformation was examined by exposing the material to a high temperature after plastic deformation. Although micropores generally show a pattern of shrinking and closing, closer inspection of a single specimen revealed a variety of geometrically variable behaviors. It is noteworthy that some of the micropores are reinitiated in positions identical to those before their annihilation, even after an 8-22% macroscopic strain has been further applied after annihilation. We attribute local variations such as these to significant local strain variation, which we measured in a series of tomographic volumes by tracking the microstructural features.

Identifying Structure-Property Relationships Through DREAM.3D Representative Volume Elements and DAMASK Crystal Plasticity Simulations: An Integrated Computational Materials Engineering Approach

Science.gov (United States)

Diehl, Martin; Groeber, Michael; Haase, Christian; Molodov, Dmitri A.; Roters, Franz; Raabe, Dierk

2017-05-01

Predicting, understanding, and controlling the mechanical behavior is the most important task when designing structural materials. Modern alloy systems—in which multiple deformation mechanisms, phases, and defects are introduced to overcome the inverse strength-ductility relationship—give raise to multiple possibilities for modifying the deformation behavior, rendering traditional, exclusively experimentally-based alloy development workflows inappropriate. For fast and efficient alloy design, it is therefore desirable to predict the mechanical performance of candidate alloys by simulation studies to replace time- and resource-consuming mechanical tests. Simulation tools suitable for this task need to correctly predict the mechanical behavior in dependence of alloy composition, microstructure, texture, phase fractions, and processing history. Here, an integrated computational materials engineering approach based on the open source software packages DREAM.3D and DAMASK (Düsseldorf Advanced Materials Simulation Kit) that enables such virtual material development is presented. More specific, our approach consists of the following three steps: (1) acquire statistical quantities that describe a microstructure, (2) build a representative volume element based on these quantities employing DREAM.3D, and (3) evaluate the representative volume using a predictive crystal plasticity material model provided by DAMASK. Exemplarily, these steps are here conducted for a high-manganese steel.

Plastic Surgery

Science.gov (United States)

... Staying Safe Videos for Educators Search English Español Plastic Surgery KidsHealth / For Teens / Plastic Surgery What's in ... her forehead lightened with a laser? What Is Plastic Surgery? Just because the name includes the word " ...

Plastic dosimeter

International Nuclear Information System (INIS)

Nagai, Shiro; Matsuda, Kohji.

1988-01-01

The report outlines major features and applications of plastic dosimeters. Some plastic dosimeters, including the CTA and PVC types, detect the response of the plastic material itself to radiations while others, such as pigment-added plastic dosimeters, contain additives as radiation detecting material. Most of these dosimeters make use of color centers produced in the dosimeter by radiations. The PMMA dosimeter is widely used in the field of radiation sterilization of food, feed and medical apparatus. The blue cellophane dosimeter is easy to handle if calibrated appropriately. The rad-color dosimeter serves to determine whether products have been irradiated appropriately. The CTA dosimeter has better damp proofing properties than the blue cellophane type. The pigment-added plastic dosimeter consists of a resin such as nylon, CTA or PVC that contains a dye. Some other plastic dosimeters are also described briefly. Though having many advantages, these plastic dosimeter have disadvantages as well. Some of their major disadvantages, including fading as well as large dependence on dose, temperature, humidity and anviroment, are discussed. (Nogami, K.)

Delivery, Effect on Cell Viability, and Plasticity of Modified Aptamer Constructs

DEFF Research Database (Denmark)

Gissberg, Olof; Zaghloul, Eman M; Lundin, Karin E

2016-01-01

AS1411 is a g-quadruplex-forming aptamer capable of selectively entering cancer cells by nucleolin receptor-mediated uptake. In this study, we investigated the cell internalization properties and plasticity of AS1411 carrying different locked nucleic acid-containing cargo oligonucleotides (ONs......) for delivery into A549 and U2OS cells. We found that internalization efficiency is highly governed by ON cargo chemistry and composition since the inherent antitumor properties of AS1411 were lost when attached to a nontoxic ON, noTox. However, a toxic ON, Tox, demonstrated potent cytotoxicity after aptamer...

Plastic debris retention and exportation by a mangrove forest patch.

Science.gov (United States)

Ivar do Sul, Juliana A; Costa, Monica F; Silva-Cavalcanti, Jacqueline S; Araújo, Maria Christina B

2014-01-15

An experiment observed the behavior of selected tagged plastic items deliberately released in different habitats of a tropical mangrove forest in NE Brazil in late rainy (September) and late dry (March) seasons. Significant differences were not reported among seasons. However, marine debris retention varied among habitats, according to characteristics such as hydrodynamic (i.e., flow rates and volume transported) and relative vegetation (Rhizophora mangle) height and density. The highest grounds retained significantly more items when compared to the borders of the river and the tidal creek. Among the used tagged items, PET bottles were more observed and margarine tubs were less observed, being easily transported to adjacent habitats. Plastic bags were the items most retained near the releasing site. The balance between items retained and items lost was positive, demonstrating that mangrove forests tend to retain plastic marine debris for long periods (months-years). Copyright © 2013 Elsevier Ltd. All rights reserved.

Study of plastic solidification process on solid radioactive waste treatment

International Nuclear Information System (INIS)

Jing Weiguan; Zhang Yinsheng; Qian Wenju

1994-01-01

Comparisons between the plastic solidification conditions of incinerated ash and waste cation resin by using thermosetting plastic polyvinyl chloride (PVC), polystyrene (PS) and polyethylene (PE), and identified physico-chemical properties and irradiation resistance of solidified products were presented. These solidified products have passed through different tests as compression strength, leachability, durability, stability, permeability and irradiation resistance (10 6 Gy) etc. The result showed that the solidified products possessed stable properties and met the storage requirement. The waste tube of radioimmunoassay, being used as solidification medium to contain incinerated ash, had good mechanical properties and satisfactory volume reduction. This process may develop a new way for disposal solid radioactive waste by means of re-using waste

Institute of Bioinorganic and Radiopharmaceutical Chemistry. Annual report 1992

International Nuclear Information System (INIS)

Johannsen, B.

1993-04-01

The Institute of Bioinorganic and Radiopharmaceutical Chemistry of the Rossendorf Research Center (FZR) presents its 1992 anual report in order to in form on research activities in the first year of its existence. This volume contains 27 individual reports devoted to various aspects of radiotracers for nuclear medicine. (BBR)

Analytical Chemistry Laboratory. Progress report for FY 1996

Energy Technology Data Exchange (ETDEWEB)

Green, D.W.; Boparai, A.S.; Bowers, D.L.

1996-12-01

The purpose of this report is to summarize the activities of the Analytical Chemistry Laboratory (ACL) at Argonne National Laboratory (ANL) for Fiscal Year (FY) 1996. This annual report is the thirteenth for the ACL. It describes effort on continuing and new projects and contributions of the ACL staff to various programs at ANL. The ACL operates in the ANL system as a full-cost-recovery service center, but has a mission that includes a complementary research and development component: The Analytical Chemistry Laboratory will provide high-quality, cost-effective chemical analysis and related technical support to solve research problems of our clients -- Argonne National Laboratory, the Department of Energy, and others -- and will conduct world-class research and development in analytical chemistry and its applications. Because of the diversity of research and development work at ANL, the ACL handles a wide range of analytical chemistry problems. Some routine or standard analyses are done, but the ACL usually works with commercial laboratories if our clients require high-volume, production-type analyses. It is common for ANL programs to generate unique problems that require significant development of methods and adaption of techniques to obtain useful analytical data. Thus, much of the support work done by the ACL is very similar to our applied analytical chemistry research.

Sustainable technological development in chemistry. Improving the quality of life through chemistry and agriculture

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-08-01

The importance of agricultural products, their potential conversion to energy sources and their applications for fibre-reinforced construction materials is emphasized. Another potentially important technology is the conversion of sunlight into electricity such as occurs in the leaves of plants. Parallels with nature exist, even though conversions with inorganic materials have, until now, been promising. The ability to control chemical reactions is the subject throughout all the following chapters. The goal is to achieve high reaction efficiencies and to use fewer basic materials, both of which will lead to a reduction in environmental stress. Sustainable developments in chemistry can be described by two approaches: (1) Improvements in society, with challenges for chemistry; and (2) Improvement in the chemical sector itself. Both approaches are dealt with in this report. Five areas for development have been chosen in the discussions for `DTO-Chemie`: Integrated plant conversion (IPC), in particular Valorisation of plant parts for raw materials and energy; Biomass conversion (C1 Chemistry), in particular Technologies for (among others) C1-based chemicals and energy carriers; Photovoltaic cells (PSC), in particular Technologies for the conversion of solar light into electricity; Process Technology in Fine chemistry (PFC), in particular Methodology of manufacturing processes for Fine chemicals; and Sustainable Construction Materials (FRC); in particular Techniques for using fibre-reinforced composites in construction applications. These areas can be viewed as clusters of technologies, with a strong chemistry and agricultural component, which are necessary for achieving a sustainable future. Furthermore, it is important to recognise that technology requires a progressive development (technology lifecycle). The five areas of technology development are tested against a number of criteria: (1) Sustainability / leap / volume; (2) Horizon 2050; (3) Commitment from industry

New developments in ophthalmic coatings on plastic lenses

Science.gov (United States)

Eigenmann, H. P.; Lobsiger, W.; Suter, R.

1998-02-01

The origin of vision aids such as eyeglasses, magnifying glasses, telescopes and so forth lies in the distant past and cannot be dated with precision. However, such aids certainly came into use at different times in different cultures. Early portraits and other pictures prove to a certainty, however, that remarkable well-made spectacles were in use by the end of the Middle Ages. Glass was employed for optical lenses from the very beginning, and quality improved continuously with advances in glassmaking and polishing techniques. Starting around 1970, this continuing development received new impetus from the introduction of plastics as a new material for ophthalmic lenses. Rapid progress in plastics chemistry had epoch-making effects on lens technology, and today a wide variety of materials such as CR39, PMMA and polycarbonates, with refractive indices ranging from 1.52 to 1.65, are used for this purpose. Eyeglasses have long been important on other grounds than vision correction; people wear them as adornment, because they are fashionable, to express their personality, and for other reasons. This dramatic history shows no signs of coming to an end, and more innovations are definitely ahead.

plastic waste recycling

African Journals Online (AJOL)

Dr Ahmed

incinerators is increasing around the world. Discarded plastic products ... Agency (EPA) estimated that the amount of plastics throw away is. 50 % greater in the ... The waste plastics were identified using the Society of the Plastic. Industry (SPI) ...

Effect of hydrostatic pressure on the deformation behavior of maraging and HY-80 steels and its implications for plasticity theory

International Nuclear Information System (INIS)

Spitzig, W.A.; Sober, R.J.; Richmond, O.

1976-01-01

Earlier results showed that the difference between the tensile and compressive strengths of tempered martensites is primarily a manifestation of the general pressure dependence of flow stress in these materials. However, the same results also showed that the volume expansion after deformation was much smaller than that predicted by the normality flow rule of plasticity theory for materials with such pressure dependence. Additional results now obtained on maraging and HY-80 steels support these conclusions. The results for all these materials exhibit a strong, but not perfect, correlation between pressure dependence, yield stress, and volume expansion. The volume expansion, however, which is believed to result primarily from the generation of new dislocations, is very small and does not appear to be essential to the pressure dependence. Most of the pressure dependence, the portion responsible for the discrepancy with the normality flow rule, may be an effect on dislocation motion. The results suggest that an appropriate plasticity model would be one in which the octahedral shear yield stress is linearly dependent on the mean pressure, but the volume change is negligible in violation of the normality flow rule. Such a model has been proposed previously for the plastic deformation of soils. However, unlike that model, the present theory includes strain hardening. 17 fig

Advances in electron transfer chemistry, v.6

CERN Document Server

Mariano, PS

1999-01-01

It is clear that electron transfer chemisty is now one of the most active areas of chemical study. Advances in Electron Transfer Chemistry has been designed to allow scientists who are developing new knowledge in this rapidly expanding area to describe their most recent research findings. This volume will serve those interested in learning about current breakthroughs in this rapidly expanding area of chemical research.

Mixing subattolitre volumes in a quantitative and highly parallel manner with soft matter nanofluidics

DEFF Research Database (Denmark)

Christensen, Sune M.; Bolinger, Pierre-Yves; Hatzakis, Nikos

2012-01-01

Handling and mixing ultrasmall volumes of reactants in parallel can increase the throughput and complexity of screening assays while simultaneously reducing reagent consumption. Microfabricated silicon and plastic can provide reliable fluidic devices, but cannot typically handle total volumes sma...

Third Chemistry Conference on Recent Trends in Chemistry

International Nuclear Information System (INIS)

Saeed, M.M.; Wheed, S.

2011-01-01

The third chemistry conference 2011 on recent trends in chemistry was held from October 17-19, 2001 at Islamabad, Pakistan. More than 65 papers and oral presentation. The scope of the conference was wide open and provides and opportunity for participation of broad spectrum of chemists. This forum provided a platform for the dissemination of the latest research followed by discussion pertaining to new trends in chemistry. This con fence covered different aspects of subjects including analytical chemistry, environmental chemistry, polymer chemistry, industrial chemistry, biochemistry and nano chemistry etc. (A.B.)

Cell plasticity and heterogeneity in cancer.

Science.gov (United States)

Marjanovic, Nemanja D; Weinberg, Robert A; Chaffer, Christine L

2013-01-01

Heterogeneity within a given cancer arises from diverse cell types recruited to the tumor and from genetic and/or epigenetic differences amongst the cancer cells themselves. These factors conspire to create a disease with various phenotypes. There are 2 established models of cancer development and progression to metastatic disease. These are the clonal evolution and cancer stem cell models. The clonal evolution theory suggests that successive mutations accumulating in a given cell generate clonal outgrowths that thrive in response to microenvironmental selection pressures, dictating the phenotype of the tumor. The alternative cancer stem cell (CSC) model suggests that cancer cells with similar genetic backgrounds can be hierarchically organized according to their tumorigenic potential. Accordingly, CSCs reside at the apex of the hierarchy and are thought to possess the majority of a cancer's tumor-initiating and metastatic ability. A defining feature of this model is its apparent unidirectional nature, whereby CSCs undergo symmetric division to replenish the CSC pool and irreversible asymmetric division to generate daughter cells (non-CSCs) with low tumorigenic potential. However, evolving evidence supports a new model of tumorigenicity, in which considerable plasticity exists between the non-CSC and CSC compartments, such that non-CSCs can reacquire a CSC phenotype. These findings suggest that some tumors may adhere to a plastic CSC model, in which bidirectional conversions are common and essential components of tumorigenicity. Accumulating evidence surrounding the plasticity of cancer cells, in particular, suggests that aggressive CSCs can be created de novo within a tumor. Given the current focus on therapeutic targeting of CSCs, we discuss the implications of non-CSC-to-CSC conversions on the development of future therapies. © 2012 American Association for Clinical Chemistry

Direct liquefaction of plastics and coprocessing of coal with plastics

Energy Technology Data Exchange (ETDEWEB)

Huffman, G.P.; Feng, Z.; Mahajan, V. [Univ. of Kentucky, Lexington, KY (United States)

1995-12-31

The objectives of this work were to optimize reaction conditions for the direct liquefaction of waste plastics and the coprocessing of coal with waste plastics. In previous work, the direct liquefaction of medium and high density polyethylene (PE), polypropylene (PPE), poly(ethylene terephthalate) (PET), and a mixed plastic waste, and the coliquefaction of these plastics with coals of three different ranks was studied. The results established that a solid acid catalyst (HZSM-5 zeolite) was highly active for the liquefaction of the plastics alone, typically giving oil yields of 80-95% and total conversions of 90-100% at temperatures of 430-450 {degrees}C. In the coliquefaction experiments, 50:50 mixtures of plastic and coal were used with a tetralin solvent (tetralin:solid = 3:2). Using approximately 1% of the HZSM-5 catalyst and a nanoscale iron catalyst, oil yields of 50-70% and total conversion of 80-90% were typical. In the current year, further investigations were conducted of the liquefaction of PE, PPE, and a commingled waste plastic obtained from the American Plastics Council (APC), and the coprocessing of PE, PPE and the APC plastic with Black Thunder subbituminous coal. Several different catalysts were used in these studies.

Experimental investigation on the properties of concrete containing post-consumer plastic waste as coarse aggregate replacement

Directory of Open Access Journals (Sweden)

Zasiah TAFHEEM

2018-03-01

Full Text Available The consumption of various forms of plastic has been increased in recent days due to the boost in industrialization and other human activities. Most of the plastic wastes are abandoned and require large landfill area for storage. More importantly, the low biodegradability of plastic poses a serious threat to environment protection issue. Various methods have been followed for the disposal of plastic in an attempt to reduce the negative impact of the plastic on the environment. Recently, various types of plastic have been incorporated in concrete to minimize the exposure of plastic to the environment. The aim of this study is to investigate the properties of concrete containing polyethylene terephthalate (PET, and high density polyethylene (HDPE plastic that were used as partial replacement of coarse aggregate (CA. In this study, four compositions of stone aggregate(S: plastic waste ratios have been used by volume basis: 100% S: 0% Plastic (control concrete, 90% S: 10% PET, 90% S: 10% HDPE, and 90% S: 5% PET+5% HDPE. The effects of waste plastic addition on the mechanical properties of concrete are presented in this paper. Test results reveal that minimum reduction in compressive strength has been found 35% in case of 10% PET plastic replaced concrete whereas splitting tensile strength for 10% PET replaced concrete has been increased by 21% while compared to control concrete. In addition, fresh unit weight of concrete containing plastic waste has been decreased by 4% in comparison to control concrete.

Pore-water chemistry effects on the compressibility behaviour of Boom Clay

International Nuclear Information System (INIS)

Deng, Y.F.; Cui, Y.J.; Tang, A.M.; Nguyen, X.P.; Li, X.L.; Maarten, V.G.

2010-01-01

%) and the soil can be classified as plastic clay. In order to study the effects of pore-water chemistry on soil compressibility, oedometer tests were performed following a specific procedure. After installation of the soil specimen (50 mm in diameter and 20 mm high) in the oedometer cell between two dry porous stones, the vertical stress was increased in steps from 0.05 MPa to 2.4 MPa, which corresponds to the in-situ effective vertical stress of the soil cores (before flushing the pore stone). After stabilisation of the soil deformation, a back-pressure of 1 MPa was applied from the lower base of the odometer cell using a volume/pressure controller. For each soil core, one test was performed using the synthetic pore-water solution and another one using distilled water. The soil volume change during the back-pressure application was monitored, Meanwhile, the volume of liquid (synthetic pore-water solution or distilled water) passing though the soil specimen was also recorded. Each test lasted about one month and it was stopped when the volume of liquid flow through the specimen was twice the pore volume of the soil specimen. This duration is believed to be long enough to determine the hydraulic conductivity under a constant head conditions (under a pressure gradient of 1 MPa). It is noted that for the test using distilled water, the important volume of liquid flow through the soil specimen allows all the in-situ pore-water to be flushed out from the specimen. At the end of this 'flushing' stage, the back-pressure was decreased to zero and loading and unloading were performed in steps with the vertical stress ranging from 0.05 to 3.2 MPa. This test allows determination of the soil compressibility and also the hydraulic conductivity at various void ratios, in the range of relatively low stresses (up to 3.2 MPa). The result shows that the hydraulic conductivity is almost independent of the pore-water used. By contrast, the soil compressibility clearly changes

Constitutional dynamic chemistry: bridge from supramolecular chemistry to adaptive chemistry.

Science.gov (United States)

Lehn, Jean-Marie

2012-01-01

Supramolecular chemistry aims at implementing highly complex chemical systems from molecular components held together by non-covalent intermolecular forces and effecting molecular recognition, catalysis and transport processes. A further step consists in the investigation of chemical systems undergoing self-organization, i.e. systems capable of spontaneously generating well-defined functional supramolecular architectures by self-assembly from their components, thus behaving as programmed chemical systems. Supramolecular chemistry is intrinsically a dynamic chemistry in view of the lability of the interactions connecting the molecular components of a supramolecular entity and the resulting ability of supramolecular species to exchange their constituents. The same holds for molecular chemistry when the molecular entity contains covalent bonds that may form and break reversibility, so as to allow a continuous change in constitution by reorganization and exchange of building blocks. These features define a Constitutional Dynamic Chemistry (CDC) on both the molecular and supramolecular levels.CDC introduces a paradigm shift with respect to constitutionally static chemistry. The latter relies on design for the generation of a target entity, whereas CDC takes advantage of dynamic diversity to allow variation and selection. The implementation of selection in chemistry introduces a fundamental change in outlook. Whereas self-organization by design strives to achieve full control over the output molecular or supramolecular entity by explicit programming, self-organization with selection operates on dynamic constitutional diversity in response to either internal or external factors to achieve adaptation.The merging of the features: -information and programmability, -dynamics and reversibility, -constitution and structural diversity, points to the emergence of adaptive and evolutive chemistry, towards a chemistry of complex matter.

Recycling potential of post-consumer plastic packaging waste in Finland.

Science.gov (United States)

Dahlbo, Helena; Poliakova, Valeria; Mylläri, Ville; Sahimaa, Olli; Anderson, Reetta

2018-01-01

Recycling of plastics is urged by the need for closing material loops to maintain our natural resources when striving towards circular economy, but also by the concern raced by observations of plastic scrap in oceans and lakes. Packaging industry is the sector using the largest share of plastics, hence packaging dominates in the plastic waste flow. The aim of this paper was to sum up the recycling potential of post-consumer plastic packaging waste in Finland. This potential was evaluated based on the quantity, composition and mechanical quality of the plastic packaging waste generated by consumers and collected as a source-separated fraction, within the mixed municipal solid waste (MSW) or within energy waste. Based on the assessment 86,000-117,000 tons (18 kg/person/a) of post-consumer plastic packaging waste was generated in Finland in 2014. The majority, 84% of the waste was in the mixed MSW flow in 2014. Due to the launching of new sorting facilities and separate collections for post-consumer plastic packaging in 2016, almost 40% of the post-consumer plastic packaging could become available for recycling. However, a 50% recycling rate for post-consumer plastic packaging (other than PET bottles) would be needed to increase the overall MSW recycling rate from the current 41% by around two percentage points. The share of monotype plastics in the overall MSW plastics fraction was 80%, hence by volume the recycling potential of MSW plastics is high. Polypropylene (PP) and low density polyethylene (LDPE) were the most common plastic types present in mixed MSW, followed by polyethylene terephthalate (PET), polystyrene (PS) and high density polyethylene (HDPE). If all the Finnish plastic packaging waste collected through the three collection types would be available for recycling, then 19,000-25,000 tons of recycled PP and 6000-8000 tons of recycled HDPE would be available on the local market. However, this assessment includes uncertainties due to performing the

Advances in high temperature chemistry

CERN Document Server

Eyring, Leroy

1969-01-01

Advances in High Temperature Chemistry, Volume 2 covers the advances in the knowledge of the high temperature behavior of materials and the complex and unfamiliar characteristics of matter at high temperature. The book discusses the dissociation energies and free energy functions of gaseous monoxides; the matrix-isolation technique applied to high temperature molecules; and the main features, the techniques for the production, detection, and diagnosis, and the applications of molecular beams in high temperatures. The text also describes the chemical research in streaming thermal plasmas, as w

Recycling of Plastic

DEFF Research Database (Denmark)

Christensen, Thomas Højlund; Fruergaard, Thilde

2011-01-01

Plastic is produced from fossil oil. Plastic is used for many different products. Some plastic products like, for example, wrapping foil, bags and disposable containers for food and beverage have very short lifetimes and thus constitute a major fraction of most waste. Other plastic products like...

Physics and Chemistry of Earth Materials

Science.gov (United States)

Navrotsky, Alexandra

1994-11-01

Stressing the fundamental solid state behavior of minerals, and emphasizing both theory and experiment, this text surveys the physics and chemistry of earth materials. The author begins with a systematic tour of crystal chemistry of both simple and complex structures (with completely new structural drawings) and discusses how to obtain structural and thermodynamic information experimentally. Dr. Navrotsky also reviews the quantitative concepts of chemical bonding--band theory, molecular orbit and ionic models. She then covers physical properties and relates microscopic features to macroscopic thermodynamic behavior and treats high pressure phase transitions, amorphous materials and solid state reactions. The author concludes with a look at the interface between mineral physics and materials science. Highly illustrated throughout, this book fills the gap between undergraduate texts and specialized review volumes and is appropriate for students and researchers in earth science and materials science.

Radiation chemistry

International Nuclear Information System (INIS)

Rodgers, F.; Rodgers, M.A.

1987-01-01

The contents of this book include: Interaction of ionizing radiation with matter; Primary products in radiation chemistry; Theoretical aspects of radiation chemistry; Theories of the solvated electron; The radiation chemistry of gases; Radiation chemistry of colloidal aggregates; Radiation chemistry of the alkali halides; Radiation chemistry of polymers; Radiation chemistry of biopolymers; Radiation processing and sterilization; and Compound index

Manhattan Project Technical Series: The Chemistry of Uranium (I)

International Nuclear Information System (INIS)

Rabinowitch, E. I.; Katz, J. J.

1947-01-01

This constitutes Chapters 11 through 16, inclusive, of the Survey Volume on Uranium Chemistry prepared for the Manhattan Project Technical Series. Chapters are titled: Uranium Oxides, Sulfides, Selenides, and Tellurides; The Non-Volatile Fluorides of Uranium; Uranium Hexafluoride; Uranium-Chlorine Compounds; Bromides, Iodides, and Pseudo-Halides of Uranium; and Oxyhalides of Uranium.

Manhattan Project Technical Series: The Chemistry of Uranium (I)

Energy Technology Data Exchange (ETDEWEB)

Rabinowitch, E. I. [Argonne National Lab. (ANL), Argonne, IL (United States); Katz, J. J. [Argonne National Lab. (ANL), Argonne, IL (United States)

1947-03-10

This constitutes Chapters 11 through 16, inclusive, of the Survey Volume on Uranium Chemistry prepared for the Manhattan Project Technical Series. Chapters are titled: Uranium Oxides, Sulfides, Selenides, and Tellurides; The Non-Volatile Fluorides of Uranium; Uranium Hexafluoride; Uranium-Chlorine Compounds; Bromides, Iodides, and Pseudo-Halides of Uranium; and Oxyhalides of Uranium.

The influence of temperature on the formation of liquid fuel from Polypropylene plastic wastes

Science.gov (United States)

Martynis, M.; Mulyazmi; Praputri, E.; Witri, R.; Putri, N.

2018-03-01

The current trend of municipal waste management in urban areas is caused by rapid changes in social, economic, political and cultural life. As a non-biodegradable polymers that have become essential materials, plastic wastes have created a very serious environmental challenge because of the huge quantities and their disposal problems. Recycling of plastics is seen as one method for reducing environmental and resource depletion. The most attractive technique of plastics recycling is pyrolysis involving the degradation of the polymeric materials by heating in the absence of oxygen. This study investigated the characteristics of pyrolysis liquid fuel (PLF) produced from polypropylene plastic wastes with temperature variations. Pyrolisis was carried out on 200 grams of polypropylene waste plastics at the operating temperature of 200°C, 250°C, 300 °C and 350 °C for 45 minutes. The liquid products were found to have carbon chain length in the range of C8-C9, similar with gasoline. The maximum density, volume and calorific value of the oil obtained were 0.8 g/cm3, 61 ml and 1307 cal/gr, respectively.

Understanding thermally activated plastic deformation behavior of Zircaloy-4

Science.gov (United States)

Kumar, N.; Alomari, A.; Murty, K. L.

2018-06-01

Understanding micromechanics of plastic deformation of existing materials is essential for improving their properties further and/or developing advanced materials for much more severe load bearing applications. The objective of the present work was to understand micromechanics of plastic deformation of Zircaloy-4, a zirconium-based alloy used as fuel cladding and channel (in BWRs) material in nuclear reactors. The Zircaloy-4 in recrystallized (at 973 K for 4 h) condition was subjected to uniaxial tensile testing at a constant cross-head velocity at temperatures in the range 293 K-1073 K and repeated stress relaxation tests at 293 K, 573 K, and 773 K. The minimum in the total elongation was indicative of dynamic strain aging phenomenon in this alloy in the intermediate temperature regime. The yield stress of the alloy was separated into effective and athermal components and the transition from thermally activated dislocation glide to athermal regime took place at around 673 K with the athermal stress estimated to be 115 MPa. The activation volume was found to be in the range of 40 b3 to 160 b3. The activation volume values and the data analyses using the solid-solution models in literature indicated dislocation-solute interaction to be a potential deformation mechanism in thermally activated regime. The activation energy calculated at 573 K was very close to that found for diffusivity of oxygen in α-Zr that was suggestive of dislocations-oxygen interaction during plastic deformation. This type of information may be helpful in alloy design in selecting different elements to control the deformation behavior of the material and impart desired mechanical properties in those materials for specific applications.

Low temperature surface chemistry and nanostructures

Science.gov (United States)

Sergeev, G. B.; Shabatina, T. I.

2002-03-01

The new scientific field of low temperature surface chemistry, which combines the low temperature chemistry (cryochemistry) and surface chemistry approaches, is reviewed in this paper. One of the most exciting achievements in this field of science is the development of methods to create highly ordered hybrid nanosized structures on different organic and inorganic surfaces and to encapsulate nanosized metal particles in organic and polymer matrices. We consider physical and chemical behaviour for the systems obtained by co-condensation of the components vapours on the surfaces cooled down to 4-10 and 70-100 K. In particular the size effect of both types, the number of atoms in the reactive species structure and the thickness of growing co-condensate film, on the chemical activity of the system is analysed in detail. The effect of the internal mechanical stresses on the growing interfacial co-condensate film formation and on the generation of fast (explosive) spontaneous reactions at low temperatures is discussed. The examples of unusual chemical interactions of metal atoms, clusters and nanosized particles, obtained in co-condensate films on the cooled surfaces under different conditions, are presented. The examples of highly ordered surface and volume hybrid nanostructures formation are analysed.

Semantic modeling of plastic deformation of polycrystalline rock

Science.gov (United States)

Babaie, Hassan A.; Davarpanah, Armita

2018-02-01

We have developed the first iteration of the Plastic Rock Deformation (PRD) ontology by modeling the semantics of a selected set of deformational processes and mechanisms that produce, reconfigure, displace, and/or consume the material components of inhomogeneous polycrystalline rocks. The PRD knowledge model also classifies and formalizes the properties (relations) that hold between instances of the dynamic physical and chemical processes and the rock components, the complex physio-chemical, mathematical, and informational concepts of the plastic rock deformation system, the measured or calculated laboratory testing conditions, experimental procedures and protocols, the state and system variables, and the empirical flow laws that define the inter-relationships among the variables. The ontology reuses classes and properties from several existing ontologies that are built for physics, chemistry, biology, and mathematics. With its flexible design, the PRD ontology is well positioned to incrementally develop into a model that more fully represents the knowledge of plastic deformation of polycrystalline rocks in the future. The domain ontology will be used to consistently annotate varied data and information related to the microstructures and the physical and chemical processes that produce them at different spatial and temporal scales in the laboratory and in the solid Earth. The PRDKB knowledge base, when built based on the ontology, will help the community of experimental structural geologists and metamorphic petrologists to coherently and uniformly distribute, discover, access, share, and use their data through automated reasoning and integration and query of heterogeneous experimental deformation data that originate from autonomous rock testing laboratories.

Plasma diagnostics discharge parameters and chemistry

CERN Document Server

Auciello, Orlando

1989-01-01

Plasma Diagnostics, Volume 1: Discharge Parameters and Chemistry covers seven chapters on the important diagnostic techniques for plasmas and details their use in particular applications. The book discusses optical diagnostic techniques for low pressure plasmas and plasma processing; plasma diagnostics for electrical discharge light sources; as well as Langmuir probes. The text also describes the mass spectroscopy of plasmas, microwave diagnostics, paramagnetic resonance diagnostics, and diagnostics in thermal plasma processing. Electrical engineers, nuclear engineers, microwave engineers, che

Evidence of multisensory plasticity: Asymmetrical medial geniculate body in people with one eye

Directory of Open Access Journals (Sweden)

Stefania S. Moro

2015-01-01

Conclusions: volume asymmetry in the MGB in people with one eye may represent increased interactions between the left MGB and primary auditory cortex. This interaction could contribute to increased auditory and other left hemisphere-dominant processing, including language, as compensation for the loss of one half of visual inputs early in life. The positive correlation between MGB and LGN volume is not due to space constraints but rather indicates increased plasticity in both auditory and visual sensory systems following early eye enucleation.

Cosmetic surgery volume and its correlation with the major US stock market indices.

Science.gov (United States)

Gordon, Chad R; Pryor, Landon; Afifi, Ahmed M; Benedetto, Paul X; Langevin, C J; Papay, Francis; Yetman, Randall; Zins, James E

2010-01-01

As a consumer-driven industry, cosmetic plastic surgery is subject to ebbs and flows as the economy changes. There have been many predictions about the short, intermediate, and long-term impact on cosmetic plastic surgery as a result of difficulties in the current economic climate, but no studies published in the literature have quantified a direct correlation. The authors investigate a possible correlation between cosmetic surgery volume and the economic trends of the three major US stock market indices. A volume analysis for the time period from January 1992 to October 2008 was performed (n = 7360 patients, n = 8205 procedures). Four cosmetic procedures-forehead lift (FL), rhytidectomy (Rh), breast augmentation (BA), and liposuction (Li)-were chosen; breast reduction (BRd), breast reconstruction (BRc), and carpal tunnel release (CTR) were selected for comparison. Case volumes for each procedure and fiscal quarter were compared to the trends of the S&P 500, Dow Jones (DOW), and NASDAQ (NASD) indices. Pearson correlation statistics were used to evaluate a relationship between the market index trends and surgical volume. P values indices. FL (n =312) only correlated to the NASD (P = .021) and did not reach significance with the S&P 500 (P = .077) or DOW (P = .14). BRd and BRc demonstrated a direct correlation to two of the three stock market indices, whereas CTR showed an inverse (ie, negative) correlation to two of the three indices. This study, to our knowledge, is the first to suggest a direct correlation of four cosmetic and two reconstructive plastic surgery procedures to the three major US stock market indices and further emphasizes the importance of a broad-based plastic surgery practice in times of economic recession.

Revision of the concept of registration threshold in plastic track detectors

International Nuclear Information System (INIS)

Somogyi, G.; Grabisch, K.; Scherzer, R.; Enge, W.

1976-01-01

Response curves (V identical Vsub(T)/Vsub(B) versus REL) of various plastic track detectors (CN, CA, PC, PET) were determined in the region of relatively low etching rate ratios V. Comparative investigations made it clear thay the registration threshold concept needs revision. It was found that for most of the commercial plastics the V(REL) curves can be well described by the relation V = 1 + αRELsup(β), where the power index is about 3 within a limit +- 10% for pure materials. With CN the situation proved to be more complex in the presence of a relatively large amount of camphor in the matrix of the detector. For the interpretation of the observed shape of the V(REL) curves, a theoretical model similar to the one that is used to describe the survival curves of irradiated biological objects, was proposed. Experiments performed for a better understanding of the nature of the radiation-damage in plastics yielded a simple relation REL = const x √D between the REL value of nuclei and the volume dose D deposited by accelerated electron beams, which produced equivalent chemical etchability in the irradiated plastics. (orig./ORU) [de

Accelerated age hardening by plastic deformation in Al-Cu with minor additions of Si and Ge

International Nuclear Information System (INIS)

Victoria Castro Riglos, M.; Taquire de la Cruz, M.; Tolley, Alfredo

2011-01-01

An extremely fast hardening response with no reduction in peak hardness was obtained in Al-Cu with minor additions of Si and Ge by 8% plastic deformation before artificial aging. The mechanism for the accelerated hardening was determined by detailed characterization with transmission electron microscopy. Plastic deformation was found to enhance the nucleation rate of Si-Ge precipitates, resulting in a higher volume density. Such precipitates catalyzed the formation of θ' precipitates that are responsible for hardening.

Structural conditions of maximal plasticity of two-phase metal materials

International Nuclear Information System (INIS)

Movchan, B.A.

1975-01-01

Analysis is given of experimental values of the strength and plasticity of iron- and tungsten-based two-phase materials with the regulated amount of the second phase and the grain size. Specimens in the form of a 120 mm x 200 mm sheet with a thickness of 0.8-1.2 mm are prepared by means of the electron beam evaporation technique and subsequent condensation of the materials on a preheated support. The variable content of the second phase along the sheet in the range 0.5 volume per cent and more than a 10-fold change in the grain size of the metallic matrix are attained by a simultaneous evaporation of pure metal (99.98 per cent) and nonlmetallic material-niobium carbide or zirconium dioxide ZrO 2 -from two separate sources. The content of arbitrarily distributed spherical particles of the second phase corresponding to a maximum of the plasticity depends only on the structural parameter - the d/D ratio. The absolute falue of the plasticity and its dependence on the temperature is a complex function of many variables - mechanical properties of particles and the matrix, peculiarities of interphase interaction on the boundary particle - matrix, the size of particles, the rate of plastic deformation and relaxation processes

Finite rate chemistry for USA-series codes - rormulation and applications

International Nuclear Information System (INIS)

Palaniswamy, S.; Chakravarthy, S.R.; Ota, D.K.

1989-01-01

The USA-series of CFD codes are based on unified solution algorithms including explicit and implicit formulations, factorization and relaxation approaches, time marching and space marching methodologies, etc., in order to be able to solve a very wide class of CFD problems using a single framework. Euler or Navier-Stokes equations are solved using a finite-volume treatment with upwind Total Variation Diminishing discretization for the inviscid terms. Recently, these codes have been enlarged to also unify different aerothermodynamic options (perfect gas, real gas including equilibrium and nonequlibrium chemistry). This paper describes aspects of the finite-rate-chemistry capability. 27 references

ANALYSIS OF DEPENDENCE OF THE FLOW TEMPERATURE OF THE PLASTICIZED POLYMER ON THE CHEMICAL STRUCTURE AND CONCENTRATION OF THE POLYMER AND THE PLASTICIZER

Directory of Open Access Journals (Sweden)

Askadskiy Andrey Aleksandrovich

2012-10-01

Full Text Available Polymeric materials are widely used in construction. The properties of polymeric construction materials vary to a substantial extent; their durability, thermal stability, frost resistance, waterproof and dielectric properties are particularly pronounced. Their properties serve as the drivers of the high market demand for these products. These materials are applied as finishing materials, molded sanitary engineering products and effective thermal insulation and water proofing materials. The authors analyze the influence of the chemical structure and structural features of polymers on their properties. The authors consider flow and vitrification temperatures of polymers. These temperatures determine the parameters of polymeric products, including those important for the construction process. The analysis of influence of concentration of the plasticizer on the vitrification temperature is based on the two basic theories. In accordance with the first one, reduction of the vitrification temperature is proportionate to the molar fraction of the injected plasticizer. According to the second concept, reduction of the vitrification temperature is proportionate to the volume fraction of the injected solvent. Dependencies of the flow temperature on the molecular weight and the molar fraction of the plasticizer are derived for PVC. As an example, two plasticizers were considered, including dibutyl sebacate and dioctylftalatalate. The basic parameters of all mixtures were calculated through the employment of "Cascade" software programme (A.N. Nesmeyanov Institute of Organoelemental Connections, Russian Academy of Sciences.

Progress in coating and radiation curing of metal and plastic objects

International Nuclear Information System (INIS)

Mayenknecht, H.

1983-01-01

The manyfold problems with one or multi-layered coatings on metal and plastic surfaces as adhesion and coat compound are the reasons for a rather slow progress of industrial applications of both radiation curing technologies (UV and EBC). Important reasons for this seemed to result from the fact that the manyfold offers of radiation sources were not optimum adapted to the chemistry of the coating materials. It was pointed out that tensions due to film contraction during polymerization process are the main reasons for insufficient adhesion. This presentation is an attempt to clarify both points of view

Investigation of plastic debris ingestion by four species of sea turtles collected as bycatch in pelagic Pacific longline fisheries.

Science.gov (United States)

Clukey, Katharine E; Lepczyk, Christopher A; Balazs, George H; Work, Thierry M; Lynch, Jennifer M

2017-07-15

Ingestion of marine debris is an established threat to sea turtles. The amount, type, color and location of ingested plastics in the gastrointestinal tracts of 55 sea turtles from Pacific longline fisheries from 2012 to 2016 were quantified, and compared across species, turtle length, body condition, sex, capture location, season and year. Six approaches for quantifying amounts of ingested plastic strongly correlated with one another and included: number of pieces, mass, volume and surface area of plastics, ratio of plastic mass to body mass, and percentage of the mass of gut contents consisting of plastic. All olive ridley (n=37), 90% of green (n=10), 80% of loggerhead (n=5) and 0% of leatherback (n=3) turtles had ingested plastic; green turtles ingested significantly more than olive ridleys. Most debris was in the large intestines. No adverse health impacts (intestinal lesions, blockage, or poor body condition) due directly to plastic ingestion were noted. Copyright © 2017. Published by Elsevier Ltd.

Platelet-rich fibrin matrix for facial plastic surgery.

Science.gov (United States)

Sclafani, Anthony P; Saman, Masoud

2012-05-01

Platelets are known primarily for their role in hemostasis, but there is increasing interest in the effect of platelets on wound healing. Platelet isolates such as platelet-rich plasma have been advocated to enhance and accelerate wound healing. This article describes the use of a novel preparation, platelet-rich fibrin matrix (PRFM), for facial plastic surgery applications such as volume augmentation, fat transfer supplementation, and as an adjunct to open surgical procedures. Copyright © 2012 Elsevier Inc. All rights reserved.

A hidden variable in shear transformation zone volume versus Poisson's ratio relation in metallic glasses

Science.gov (United States)

Kim, S. Y.; Oh, H. S.; Park, E. S.

2017-10-01

Herein, we elucidate a hidden variable in a shear transformation zone (STZ) volume (Ω) versus Poisson's ratio (ν) relation and clarify the correlation between STZ characteristics and the plasticity of metallic glasses (MGs). On the basis of cooperative shear model and atomic stress theories, we carefully formulate Ω as a function of molar volume (Vm) and ν. The twofold trend in Ω and ν is attributed to a relatively large variation of Vm as compared to that of ν as well as an inverse relation between Vm and ν. Indeed, the derived equation reveals that the number of atoms in an STZ instead of Ω is a microstructural characteristic which has a close relationship with plasticity since it reflects the preference of atomistic behaviors between cooperative shearing and the generation of volume strain fluctuation under stress. The results would deepen our understanding of the correlation between microscopic behaviors (STZ activation) and macroscopic properties (plasticity) in MGs and enable a quantitative approach in associating various STZ-related macroscopic behaviors with intrinsic properties of MGs.

Plastic value chains

DEFF Research Database (Denmark)

Baxter, John; Wahlstrom, Margareta; Zu Castell-Rüdenhausen, Malin

2014-01-01

Optimizing plastic value chains is regarded as an important measure in order to increase recycling of plastics in an efficient way. This can also lead to improved awareness of the hazardous substances contained in plastic waste, and how to avoid that these substances are recycled. As an example......, plastics from WEEE is chosen as a Nordic case study. The project aims to propose a number of improvements for this value chain together with representatives from Nordic stakeholders. Based on the experiences made, a guide for other plastic value chains shall be developed....

Our plastic age.

Science.gov (United States)

Thompson, Richard C; Swan, Shanna H; Moore, Charles J; vom Saal, Frederick S

2009-07-27

Within the last few decades, plastics have revolutionized our daily lives. Globally we use in excess of 260 million tonnes of plastic per annum, accounting for approximately 8 per cent of world oil production. In this Theme Issue of Philosophical Transactions of the Royal Society, we describe current and future trends in usage, together with the many benefits that plastics bring to society. At the same time, we examine the environmental consequences resulting from the accumulation of waste plastic, the effects of plastic debris on wildlife and concerns for human health that arise from the production, usage and disposal of plastics. Finally, we consider some possible solutions to these problems together with the research and policy priorities necessary for their implementation.

Our plastic age

Science.gov (United States)

Thompson, Richard C.; Swan, Shanna H.; Moore, Charles J.; vom Saal, Frederick S.

2009-01-01

Within the last few decades, plastics have revolutionized our daily lives. Globally we use in excess of 260 million tonnes of plastic per annum, accounting for approximately 8 per cent of world oil production. In this Theme Issue of Philosophical Transactions of the Royal Society, we describe current and future trends in usage, together with the many benefits that plastics bring to society. At the same time, we examine the environmental consequences resulting from the accumulation of waste plastic, the effects of plastic debris on wildlife and concerns for human health that arise from the production, usage and disposal of plastics. Finally, we consider some possible solutions to these problems together with the research and policy priorities necessary for their implementation. PMID:19528049

Determinants of recycling common types of plastic product waste in environmental horticulture industry: The case of Georgia.

Science.gov (United States)

Meng, Ting; Klepacka, Anna M; Florkowski, Wojciech J; Braman, Kristine

2016-02-01

Environmental horticulture firms provide a variety of commercial/residential landscape products and services encompassing ornamental plant production, design, installation, and maintenance. The companies generate tons of waste including plastic containers, trays, and greenhouse/field covers, creating the need to reduce and utilize plastic waste. Based on survey data collected in Georgia in 2013, this paper investigates determinants of the environmental horticulture firms' recycling decision (plastic containers, flats, and greenhouse poly). Our findings indicate that the decision to discard vs. recycle plastic containers, flats, and greenhouse poly is significantly influenced by firm scope, size, location, and partnership with recycling providers, as well as whether recycling providers offer additional waste pickup services. Insights from this study are of use to local governments and environmental organizations interested in increasing horticultural firm participation in recycling programs and lowering the volume of plastic destined for landfills. Copyright © 2015 Elsevier Ltd. All rights reserved.

Complex chemistry

International Nuclear Information System (INIS)

Kim, Bong Gon; Kim, Jae Sang; Kim, Jin Eun; Lee, Boo Yeon

2006-06-01

This book introduces complex chemistry with ten chapters, which include development of complex chemistry on history coordination theory and Warner's coordination theory and new development of complex chemistry, nomenclature on complex with conception and define, chemical formula on coordination compound, symbol of stereochemistry, stereo structure and isomerism, electron structure and bond theory on complex, structure of complex like NMR and XAFS, balance and reaction on solution, an organo-metallic chemistry, biology inorganic chemistry, material chemistry of complex, design of complex and calculation chemistry.

Plastic scintillation dosimetry: Optimal selection of scintillating fibers and scintillators

International Nuclear Information System (INIS)

Archambault, Louis; Arsenault, Jean; Gingras, Luc; Sam Beddar, A.; Roy, Rene; Beaulieu, Luc

2005-01-01

Scintillation dosimetry is a promising avenue for evaluating dose patterns delivered by intensity-modulated radiation therapy plans or for the small fields involved in stereotactic radiosurgery. However, the increase in signal has been the goal for many authors. In this paper, a comparison is made between plastic scintillating fibers and plastic scintillator. The collection of scintillation light was measured experimentally for four commercial models of scintillating fibers (BCF-12, BCF-60, SCSF-78, SCSF-3HF) and two models of plastic scintillators (BC-400, BC-408). The emission spectra of all six scintillators were obtained by using an optical spectrum analyzer and they were compared with theoretical behavior. For scintillation in the blue region, the signal intensity of a singly clad scintillating fiber (BCF-12) was 120% of that of the plastic scintillator (BC-400). For the multiclad fiber (SCSF-78), the signal reached 144% of that of the plastic scintillator. The intensity of the green scintillating fibers was lower than that of the plastic scintillator: 47% for the singly clad fiber (BCF-60) and 77% for the multiclad fiber (SCSF-3HF). The collected light was studied as a function of the scintillator length and radius for a cylindrical probe. We found that symmetric detectors with nearly the same spatial resolution in each direction (2 mm in diameter by 3 mm in length) could be made with a signal equivalent to those of the more commonly used asymmetric scintillators. With augmentation of the signal-to-noise ratio in consideration, this paper presents a series of comparisons that should provide insight into selection of a scintillator type and volume for development of a medical dosimeter

A finite difference method for off-fault plasticity throughout the earthquake cycle

Science.gov (United States)

Erickson, Brittany A.; Dunham, Eric M.; Khosravifar, Arash

2017-12-01

We have developed an efficient computational framework for simulating multiple earthquake cycles with off-fault plasticity. The method is developed for the classical antiplane problem of a vertical strike-slip fault governed by rate-and-state friction, with inertial effects captured through the radiation-damping approximation. Both rate-independent plasticity and viscoplasticity are considered, where stresses are constrained by a Drucker-Prager yield condition. The off-fault volume is discretized using finite differences and tectonic loading is imposed by displacing the remote side boundaries at a constant rate. Time-stepping combines an adaptive Runge-Kutta method with an incremental solution process which makes use of an elastoplastic tangent stiffness tensor and the return-mapping algorithm. Solutions are verified by convergence tests and comparison to a finite element solution. We quantify how viscosity, isotropic hardening, and cohesion affect the magnitude and off-fault extent of plastic strain that develops over many ruptures. If hardening is included, plastic strain saturates after the first event and the response during subsequent ruptures is effectively elastic. For viscoplasticity without hardening, however, successive ruptures continue to generate additional plastic strain. In all cases, coseismic slip in the shallow sub-surface is diminished compared to slip accumulated at depth during interseismic loading. The evolution of this slip deficit with each subsequent event, however, is dictated by the plasticity model. Integration of the off-fault plastic strain from the viscoplastic model reveals that a significant amount of tectonic offset is accommodated by inelastic deformation ( ∼ 0.1 m per rupture, or ∼ 10% of the tectonic deformation budget).

Low temperature conversion of plastic waste into light hydrocarbons

International Nuclear Information System (INIS)

Shah, Sajid Hussain; Khan, Zahid Mahmood; Raja, Iftikhar Ahmad; Mahmood, Qaisar; Bhatti, Zulfiqar Ahmad; Khan, Jamil; Farooq, Ather; Rashid, Naim; Wu, Donglei

2010-01-01

Advance recycling through pyrolytic technology has the potential of being applied to the management of plastic waste (PW). For this purpose 1 l volume, energy efficient batch reactor was manufactured locally and tested for pyrolysis of waste plastic. The feedstock for reactor was 50 g waste polyethylene. The average yield of the pyrolytic oil, wax, pyrogas and char from pyrolysis of PW were 48.6, 40.7, 10.1 and 0.6%, respectively, at 275 deg. C with non-catalytic process. Using catalyst the average yields of pyrolytic oil, pyrogas, wax and residue (char) of 50 g of PW was 47.98, 35.43, 16.09 and 0.50%, respectively, at operating temperature of 250 deg. C. The designed reactor could work at low temperature in the absence of a catalyst to obtain similar products as for a catalytic process.

Use of wall-less 18F-doped gelatin phantoms for improved volume delineation and quantification in PET/CT

International Nuclear Information System (INIS)

Sydoff, Marie; Andersson, Martin; Mattsson, Sören; Leide-Svegborn, Sigrid

2014-01-01

Positron emission tomography (PET) with 18 F-FDG is a valuable tool for staging, planning treatment, and evaluating the treatment response for many different types of tumours. The correct volume estimation is of utmost importance in these situations. To date, the most common types of phantoms used in volume quantification in PET utilize fillable, hollow spheres placed in a circular or elliptical cylinder made of polymethyl methacrylate. However, the presence of a non-radioactive sphere wall between the hotspot and the background activity in images of this type of phantom could cause inaccuracies. To investigate the influence of the non-active walls, we developed a phantom without non-active sphere walls for volume delineation and quantification in PET. Three sizes of gelatin hotspots were moulded and placed in a Jaszczak phantom together with hollow plastic spheres of the same sizes containing the same activity concentration. 18 F PET measurements were made with zero background activity and with tumour-to-background ratios of 12.5, 10, 7.5, and 5. The background-corrected volume reproducing threshold, T vol , was calculated for both the gelatin and the plastic spheres. It was experimentally verified that the apparent background dependence of T vol , i.e., a decreasing T vol  with increasing background fraction, was not present for wall-less spheres; the opposite results were seen in plastic, hollow spheres in commercially-available phantoms. For the types of phantoms commonly used in activity quantification, the estimation of T vol  using fillable, hollow, plastic spheres with non-active walls would lead to an overestimate of the tumour volume, especially for small volumes in a high activity background. (paper)

Use of wall-less 18F-doped gelatin phantoms for improved volume delineation and quantification in PET/CT

Science.gov (United States)

Sydoff, Marie; Andersson, Martin; Mattsson, Sören; Leide-Svegborn, Sigrid

2014-03-01

Positron emission tomography (PET) with 18F-FDG is a valuable tool for staging, planning treatment, and evaluating the treatment response for many different types of tumours. The correct volume estimation is of utmost importance in these situations. To date, the most common types of phantoms used in volume quantification in PET utilize fillable, hollow spheres placed in a circular or elliptical cylinder made of polymethyl methacrylate. However, the presence of a non-radioactive sphere wall between the hotspot and the background activity in images of this type of phantom could cause inaccuracies. To investigate the influence of the non-active walls, we developed a phantom without non-active sphere walls for volume delineation and quantification in PET. Three sizes of gelatin hotspots were moulded and placed in a Jaszczak phantom together with hollow plastic spheres of the same sizes containing the same activity concentration. 18F PET measurements were made with zero background activity and with tumour-to-background ratios of 12.5, 10, 7.5, and 5. The background-corrected volume reproducing threshold, Tvol, was calculated for both the gelatin and the plastic spheres. It was experimentally verified that the apparent background dependence of Tvol, i.e., a decreasing Tvol with increasing background fraction, was not present for wall-less spheres; the opposite results were seen in plastic, hollow spheres in commercially-available phantoms. For the types of phantoms commonly used in activity quantification, the estimation of Tvol using fillable, hollow, plastic spheres with non-active walls would lead to an overestimate of the tumour volume, especially for small volumes in a high activity background.

Production low cost plastic scintillator by using commercial polystyrene

International Nuclear Information System (INIS)

2011-01-01

were produced with those determined parameters in 12 June 2008. Plastic blocks prepared were optically and mechanically tested and its response against various radioactive sources was measured. The results regarding the optical, mechanical and detection properties of blocks produced in 10x5x40 cm dimension were compared with commercial LODLUM Scintillator (main component PVT) produced by US in 13x8x120 cm dimensions. It was found that optical and mechanical properties of blocks produced in SANAEM are similar to or better than that of LODLUM. Plastic scintillator produced in SANAEM has shown the same response and counting characteristics that obtained by LODLUM, but proportional to its area and/or volume specifications. This study has shown that plastic scintillators imported can be produced in SANAEM domestically and be used for detection of radioactive materials within the country or border gates.

Impact of Bio-Based Plastics on Current Recycling of Plastics

Directory of Open Access Journals (Sweden)

Luc Alaerts

2018-05-01

Full Text Available Bio-based plastics are increasingly appearing in a range of consumption products, and after use they often end up in technical recycling chains. Bio-based plastics are different from fossil-based ones and could disturb the current recycling of plastics and hence inhibit the closure of plastic cycles, which is undesirable given the current focus on a transition towards a circular economy. In this paper, this risk has been assessed via three elaborated case studies using data and information retrieved through an extended literature search. No overall risks were revealed for bio-based plastics as a group; rather, every bio-based plastic is to be considered as a potential separate source of contamination in current recycling practices. For PLA (polylactic acid, a severe incompatibility with PET (polyethylene terephthalate recycling is known; hence, future risks are assessed by measuring amounts of PLA ending up in PET waste streams. For PHA (polyhydroxy alkanoate there is no risk currently, but it will be crucial to monitor future application development. For PEF (polyethylene furanoate, a particular approach for contamination-related issues has been included in the upcoming market introduction. With respect to developing policy, it is important that any introduction of novel plastics is well guided from a system perspective and with a particular eye on incompatibilities with current and upcoming practices in the recycling of plastics.

A Microscale Approach to Chemical Kinetics in the General Chemistry Laboratory: The Potassium Iodide Hydrogen Peroxide Iodine-Clock Reaction

Science.gov (United States)

Sattsangi, Prem D.

2011-01-01

A microscale laboratory for teaching chemical kinetics utilizing the iodine clock reaction is described. Plastic pipets, 3 mL volume, are used to store and deliver precise drops of reagents and the reaction is run in a 24 well plastic tray using a total 60 drops of reagents. With this procedure, students determine the rate of reaction and the…

Plastic condoms.

Science.gov (United States)

1968-01-01

Only simple equipment, simple technology and low initial capital investment are needed in their manufacture. The condoms can be made by people who were previously unskilled or only semi-skilled workers. Plastic condoms differ from those made of latex rubber in that the nature of the plastic film allows unlimited shelf-life. Also, the plastic has a higher degree of lubricity than latex rubber; if there is a demand for extra lubrication in a particular market, this can be provided. Because the plastic is inert, these condoms need not be packaged in hermetically sealed containers. All these attributes make it possible to put these condoms on the distributors' shelves in developing countries competitively with rubber condoms. The shape of the plastic condom is based on that of the lamb caecum, which has long been used as luxury-type condom. The plastic condom is made from plastic film (ethylene ethyl acrilate) of 0.001 inch (0.0254 mm.) thickness. In addition, a rubber ring is provided and sealed into the base of the condom for retention during coitus. The advantage of the plastic condom design and the equipment on which it is made is that production can be carried out either in labour-intensive economy or with varying degrees of mechanization and automation. The uniform, finished condom if made using previously untrained workers. Training of workers can be done in a matter of hours on the two machines which are needed to produce and test the condoms. The plastic film is provided on a double wound roll, and condom blanks are prepared by means of a heat-sealing die on the stamping machine. The rubber rings are united to the condom blanks on an assembly machine, which consists of a mandrel and heat-sealing equipment to seal the rubber ring to the base of the condom. Built into the assembly machine is a simple air-testing apparatus that can detect the smallest pinhole flaw in a condom. The manufacturing process is completed by unravelling the condom from the assembly

Stereological quantification of tumor volume, mean nuclear volume and total number of melanoma cells correlated with morbidity and mortality

DEFF Research Database (Denmark)

Bønnelykke-Behrndtz, Marie Louise; Sørensen, Flemming Brandt; Damsgaard, Tine Engberg

2008-01-01

potential indicators of prognosis. Sixty patients who underwent surgery at the Department of Plastic Surgery, Aarhus University Hospital, from 1991 to 1994 were included in the study. Total tumor volume was estimated by the Cavalieri technique, total number of tumor cells by the optical dissector principle...... showed a significant impact on both disease-free survival (p=0.001) and mortality (p=0.009). In conclusion, tumor volume and total number of cancer cells were highly reproducible but did not add additional, independent prognostic information regarding the study population.......Stereological quantification of tumor volume, total number of tumor cells and mean nuclear volume provides unbiased data, regardless of the three-dimensional shape of the melanocytic lesion. The aim of the present study was to investigate whether these variables are reproducible and may represent...

On a phase field approach for martensitic transformations in a crystal plastic material at a loaded surface

Science.gov (United States)

Schmitt, Regina; Kuhn, Charlotte; Müller, Ralf

2017-07-01

A continuum phase field model for martensitic transformations is introduced, including crystal plasticity with different slip systems for the different phases. In a 2D setting, the transformation-induced eigenstrain is taken into account for two martensitic orientation variants. With aid of the model, the phase transition and its dependence on the volume change, crystal plastic material behavior, and the inheritance of plastic deformations from austenite to martensite are studied in detail. The numerical setup is motivated by the process of cryogenic turning. The resulting microstructure qualitatively coincides with an experimentally obtained martensite structure. For the numerical calculations, finite elements together with global and local implicit time integration scheme are employed.

Biodegradability of plastics.

Science.gov (United States)

Tokiwa, Yutaka; Calabia, Buenaventurada P; Ugwu, Charles U; Aiba, Seiichi

2009-08-26

Plastic is a broad name given to different polymers with high molecular weight, which can be degraded by various processes. However, considering their abundance in the environment and their specificity in attacking plastics, biodegradation of plastics by microorganisms and enzymes seems to be the most effective process. When plastics are used as substrates for microorganisms, evaluation of their biodegradability should not only be based on their chemical structure, but also on their physical properties (melting point, glass transition temperature, crystallinity, storage modulus etc.). In this review, microbial and enzymatic biodegradation of plastics and some factors that affect their biodegradability are discussed.

Thermal volume changes in clays and clay-stones

International Nuclear Information System (INIS)

Delage, P.; Sulem, J.; Mohajerani, M.; Tang, A.M.; Monfared, M.

2012-01-01

Document available in extended abstract form only. The disposal of high activity exothermic radioactive waste at great depth in clay host rocks will induce a temperature elevation that has been investigated in various underground research laboratories in Belgium, France and Switzerland through in-situ tests. Thermal effects are better known in clays (in particular Boom clay) than in clay-stone (e.g. Opalinus clay and Callovo-Oxfordian clay-stone). In terms of volume changes, Figure 1 confirms the findings of Hueckel and Baldi (1990) that volume changes depend on the over-consolidation ratio (OCR) of the clay. In drained conditions, normally consolidated clays exhibit plastic contraction when heated, whereas over-consolidated clay exhibit elastic dilation. The nature of thermal volume changes in heated clays obviously has a significant effect on thermally induced pore pressures, when drainage is not instantaneous like what occurs in-situ. Compared to clays, the thermal volume change behaviour of clay-stones is less well known than that of clays. clay-stone are a priori suspected to behave like over-consolidated clays. In this paper, a comparison of recent results obtained in the laboratory on the drained thermal volume changes of clay-stones is presented and discussed. It is difficult to run drained mechanical tests in clay-stones like the Opalinus clay and the Callovo-Oxfordian clay-stone because of their quite low permeability (10 -12 - 10 -13 m/s). This also holds true for thermal tests. Due to the significant difference in thermal expansion coefficient between minerals and water, it is necessary to adopt very slow heating rate (0.5 - 1 C/h) to avoid any thermal pressurization. To do so, a new hollow cylinder apparatus (100 mm external diameter, 60 mm internal diameter) with lateral drainages reducing the drainage length to half the sample thickness (10 mm) has been developed (Monfared et al. 2011). The results of a drained cyclic thermal test carried out on

The chemistry of nonaqueous solvents v.4 solution phenomena and aprotic solvents

CERN Document Server

Lagowski, J J

1976-01-01

The Chemistry of Nonaqueous Solvents, Volume IV: Solution Phenomena and Aprotic Solvents focuses on the chemistry of nonaqueous solvents, with emphasis on solution phenomena and aprotic solvents such as tetramethylurea, inorganic acid chlorides, cyclic carbonates, and sulfolane. This book is organized into seven chapters and begins with an overview of the theory of electrical conductivity and elementary experimental considerations, along with some of the interesting research on nonaqueous solvents. It then turns to a discussion on hydrogen bonding phenomena in nonaqueous systems as probed

Vehicle routing for the eco-efficient collection of household plastic waste.

Science.gov (United States)

Bing, Xiaoyun; de Keizer, Marlies; Bloemhof-Ruwaard, Jacqueline M; van der Vorst, Jack G A J

2014-04-01

Plastic waste is a special category of municipal solid waste. Plastic waste collection is featured with various alternatives of collection methods (curbside/drop-off) and separation methods (source-/post-separation). In the Netherlands, the collection routes of plastic waste are the same as those of other waste, although plastic is different than other waste in terms of volume to weight ratio. This paper aims for redesigning the collection routes and compares the collection options of plastic waste using eco-efficiency as performance indicator. Eco-efficiency concerns the trade-off between environmental impacts, social issues and costs. The collection problem is modeled as a vehicle routing problem. A tabu search heuristic is used to improve the routes. Collection alternatives are compared by a scenario study approach. Real distances between locations are calculated with MapPoint. The scenario study is conducted based on real case data of the Dutch municipality Wageningen. Scenarios are designed according to the collection alternatives with different assumptions in collection method, vehicle type, collection frequency and collection points, etc. Results show that the current collection routes can be improved in terms of eco-efficiency performance by using our method. The source-separation drop-off collection scenario has the best performance for plastic collection assuming householders take the waste to the drop-off points in a sustainable manner. The model also shows to be an efficient decision support tool to investigate the impacts of future changes such as alternative vehicle type and different response rates. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

Development of a Plastic Melt Waste Compactor for Space Missions Experiments and Prototype Design

Science.gov (United States)

Pace, Gregory; Wignarajah, Kanapathipillai; Pisharody, Suresh; Fisher, John

2004-01-01

This paper describes development at NASA Ames Research Center of a heat melt compactor that can be used on both near term and far term missions. Experiments have been performed to characterize the behavior of composite wastes that are representative of the types of wastes produced on current and previous space missions such as International Space Station, Space Shuttle, MIR and Skylab. Experiments were conducted to characterize the volume reduction, bonding, encapsulation and biological stability of the waste composite and also to investigate other key design issues such as plastic extrusion, noxious off-gassing and removal of the of the plastic waste product from the processor. The experiments provided the data needed to design a prototype plastic melt waste processor, a description of which is included in the paper.

Measurements of the electron dose distribution near inhomogeneities using a plastic scintillation detector

International Nuclear Information System (INIS)

Wells, C.M.M.; Mackie, T.R.; Podgorsak, M.B.; Holmes, M.A.; Papanikolaou, N.; Reckwerdt, P.J.; Cygler, J.; Rogers, D.W.O.; Bielajew, A.F.; Schmidt, D.G.

1994-01-01

Accurate measurement of the electron dose distribution near an inhomogeneity is difficult with traditional dosimeters which themselves perturb the electron field. The authors tested the performance of a new high resolution, water-equivalent plastic scintillation detector which has ideal properties for this application. A plastic scintillation detector with a 1 mm diameter, 3 mm long cylindrical sensitive volume was used to measure the dose distributions behind standard benchmark inhomogeneities in water phantoms. The plastic scintillator material is more water equivalent than polystyrene in terms of its mass collision stopping power and mass scattering power. Measurements were performed for beams of electrons having initial energies of 6 and 18 MeV at depths from 0.2-4.2 cm behind the inhomogeneities. The detector reveals hot and cold spots behind heterogeneities at resolutions equivalent to typical film digitizer spot sizes. Plots of the dose distributions behind air, aluminum, lead, and formulations for cortical and inner bone-equivalent materials are presented. The plastic scintillation detector is suited for measuring the electron dose distribution near an inhomogeneity. 14 refs., 9 figs

Characterization of plastic blends made from mixed plastics waste of different sources.

Science.gov (United States)

Turku, Irina; Kärki, Timo; Rinne, Kimmo; Puurtinen, Ari

2017-02-01

This paper studies the recyclability of construction and household plastic waste collected from local landfills. Samples were processed from mixed plastic waste by injection moulding. In addition, blends of pure plastics, polypropylene and polyethylene were processed as a reference set. Reference samples with known plastic ratio were used as the calibration set for quantitative analysis of plastic fractions in recycled blends. The samples were tested for the tensile properties; scanning electron microscope-energy-dispersive X-ray spectroscopy was used for elemental analysis of the blend surfaces and Fourier transform infrared (FTIR) analysis was used for the quantification of plastics contents.

The Prevalence of Cosmetic Facial Plastic Procedures among Facial Plastic Surgeons.

Science.gov (United States)

Moayer, Roxana; Sand, Jordan P; Han, Albert; Nabili, Vishad; Keller, Gregory S

2018-04-01

This is the first study to report on the prevalence of cosmetic facial plastic surgery use among facial plastic surgeons. The aim of this study is to determine the frequency with which facial plastic surgeons have cosmetic procedures themselves. A secondary aim is to determine whether trends in usage of cosmetic facial procedures among facial plastic surgeons are similar to that of nonsurgeons. The study design was an anonymous, five-question, Internet survey distributed via email set in a single academic institution. Board-certified members of the American Academy of Facial Plastic and Reconstructive Surgery (AAFPRS) were included in this study. Self-reported history of cosmetic facial plastic surgery or minimally invasive procedures were recorded. The survey also queried participants for demographic data. A total of 216 members of the AAFPRS responded to the questionnaire. Ninety percent of respondents were male ( n  = 192) and 10.3% were female ( n  = 22). Thirty-three percent of respondents were aged 31 to 40 years ( n  = 70), 25% were aged 41 to 50 years ( n  = 53), 21.4% were aged 51 to 60 years ( n  = 46), and 20.5% were older than 60 years ( n  = 44). Thirty-six percent of respondents had a surgical cosmetic facial procedure and 75% has at least one minimally invasive cosmetic facial procedure. Facial plastic surgeons are frequent users of cosmetic facial plastic surgery. This finding may be due to access, knowledge base, values, or attitudes. By better understanding surgeon attitudes toward facial plastic surgery, we can improve communication with patients and delivery of care. This study is a first step in understanding use of facial plastic procedures among facial plastic surgeons. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Computational upscaling of Drucker-Prager plasticity from micro-CT images of synthetic porous rock

Science.gov (United States)

Liu, Jie; Sarout, Joel; Zhang, Minchao; Dautriat, Jeremie; Veveakis, Emmanouil; Regenauer-Lieb, Klaus

2018-01-01

Quantifying rock physical properties is essential for the mining and petroleum industry. Microtomography provides a new way to quantify the relationship between the microstructure and the mechanical and transport properties of a rock. Studies reporting the use microtomographic images to derive permeability and elastic moduli of rocks are common; only rare studies were devoted to yield and failure parameters using this technique. In this study, we simulate the macroscale plastic properties of a synthetic sandstone sample made of calcite-cemented quartz grains using the microscale information obtained from microtomography. The computations rely on the concept of representative volume elements (RVEs). The mechanical RVE is determined using the upper and lower bounds of finite-element computations for elasticity. We present computational upscaling methods from microphysical processes to extract the plasticity parameters of the RVE and compare results to experimental data. The yield stress, cohesion and internal friction angle of the matrix (solid part) of the rock were obtained with reasonable accuracy. Computations of plasticity of a series of models of different volume-sizes showed almost overlapping stress-strain curves, suggesting that the mechanical RVE determined by elastic computations is also valid for plastic yielding. Furthermore, a series of models were created by self-similarly inflating/deflating the porous models, that is keeping a similar structure while achieving different porosity values. The analysis of these models showed that yield stress, cohesion and internal friction angle linearly decrease with increasing porosity in the porosity range between 8 and 28 per cent. The internal friction angle decreases the most significantly, while cohesion remains stable.

Chemical sensitive interfacial free volume studies of nanophase Al-rich alloys

International Nuclear Information System (INIS)

Lechner, W.; Puff, W.; Wuerschum, R.; Wilde, G.

2006-01-01

Full text: Al-based nanocrystalline alloys have attracted substantial interest due to their outstanding mechanical properties. These alloys can be obtained by crystallization of melt-spun amorphous precursors or by grain refinement upon repeated cold-rolling of elemental layers. For both synthesis routes, the nanocrystallization process is sensitively affected by interfacial chemistry and free volumes. In order to contribute to an atomistic understanding of the interfacial structure and processes during nanocrystallization, the present work deals with studies of interfacial free volumes by means of positron-annihilation-spectroscopy. In addition to positron lifetime spectroscopy which yields information on the size of free volumes, coincident Doppler broadening of the positron-electron annihilation photons is applied as novel technique for studying the chemistry of interfaces in nanophase materials on an atomistic scale. Al-rich alloys of the above mentioned synthesis routes were studied in this work. (author)

Recycling of plastic waste: Presence of phthalates in plastics from households and industry

DEFF Research Database (Denmark)

Pivnenko, Kostyantyn; Eriksen, Marie Kampmann; Martín-Fernández, J. A.

2016-01-01

Plastics recycling has the potential to substitute virgin plastics partially as a source of raw materials in plastic product manufacturing. Plastic as a material may contain a variety of chemicals, some potentially hazardous. Phthalates, for instance, are a group of chemicals produced in large...... recognised, the influence of plastic recycling on phthalate content has been hypothesised but not well documented. In the present work we analysed selected phthalates (DMP, DEP, DPP, DiBP, DBP, BBzP, DEHP, DCHP and DnOP) in samples of waste plastics as well as recycled and virgin plastics. DBP, DiBP and DEHP...

Biodegradability of Plastics

Directory of Open Access Journals (Sweden)

Yutaka Tokiwa

2009-08-01

Full Text Available Plastic is a broad name given to different polymers with high molecular weight, which can be degraded by various processes. However, considering their abundance in the environment and their specificity in attacking plastics, biodegradation of plastics by microorganisms and enzymes seems to be the most effective process. When plastics are used as substrates for microorganisms, evaluation of their biodegradability should not only be based on their chemical structure, but also on their physical properties (melting point, glass transition temperature, crystallinity, storage modulus etc.. In this review, microbial and enzymatic biodegradation of plastics and some factors that affect their biodegradability are discussed.

Length of Acupuncture Training and Structural Plastic Brain Changes in Professional Acupuncturists.

Directory of Open Access Journals (Sweden)

Minghao Dong

Full Text Available The research on brain plasticity has fascinated researchers for decades. Use/training serves as an instrumental factor to influence brain neuroplasticity. Parallel to acquisition of behavioral expertise, extensive use/training is concomitant with substantial changes of cortical structure. Acupuncturists, serving as a model par excellence to study tactile-motor and emotional regulation plasticity, receive intensive training in national medical schools following standardized training protocol. Moreover, their behavioral expertise is corroborated during long-term clinical practice. Although our previous study reported functional plastic brain changes in the acupuncturists, whether or not structural plastic changes occurred in acupuncturists is yet elusive.Cohorts of acupuncturists (N = 22 and non-acupuncturists (N = 22 were recruited. Behavioral tests were delivered to assess the acupuncturists' behavioral expertise. The results confirmed acupuncturists' tactile-motor skills and emotion regulation proficiency compared to non-acupuncturists. Using the voxel-based morphometry technique, we revealed larger grey matter volumes in acupuncturists in the hand representation of the contralateral primary somatosensory cortex (SI, the right lobule V/VI and the bilateral ventral anterior cingulate cortex/ventral medial prefrontal cortex. Grey matter volumes of the SI and Lobule V/VI positively correlated with the duration of acupuncture practice.To our best knowledge, this study provides first evidence for the anatomical alterations in acupuncturists, which would possibly be the neural correlates underlying acupuncturists' exceptional skills. On one hand, we suggest our findings may have ramifications for tactile-motor rehabilitation. On the other hand, our results in emotion regulation domain may serve as a target for our future studies, from which we can understand how modulations of aversive emotions elicited by empathic pain develop in the context

Elastic-plastic behaviour of thick-walled containers considering plastic compressibility

International Nuclear Information System (INIS)

Betten, J.; Frosch, H.G.

1983-01-01

In this paper the elastic-plastic behaviour of thick-walled pressure vessels with internal and external pressure is studied. To describe the mechanical behaviour of isotropic, plastic compressible materials we use a plastic potential which is a single-valued function of the principle stresses. For cylinders and spheres an analytic expression for the computation of stresses and residual stresses is specified. Afterwards the strains are calculated by using the finite difference method. Some examples will high-light the influence of the plastic compressibility on the behaviour of pressure vessels. (orig.) [de

Helium-hydrogen microplasma device (MPD) on postage-stamp-size plastic-quartz chips.

Science.gov (United States)

Weagant, Scott; Karanassios, Vassili

2009-10-01

A new design of a miniaturized, atmospheric-pressure, low-power (e.g., battery-operated), self-igniting, planar-geometry microplasma device (MPD) for use with liquid microsamples is described. The inexpensive MPD was a hybrid, three-substrate quartz-plastic-plastic structure and it was formed on chips with area the size of a small postage stamp. The substrates were chosen for rapid prototyping and for speedy device-geometry testing and evaluation. The approximately 700-microm (diameter) and 7-mm (long) He-H(2) (3% H(2)) microplasma was formed by applying high-voltage ac between two needle electrodes. Operating conditions were found to be critical in sustaining stable microplasma on plastic substrates. Spectral interference from the electrode materials was not observed. A small-size, electrothermal vaporization system was used for introduction of microliter volumes of liquids into the MPD. The microplasma was operated from an inexpensive power supply. And, operation from a 14.4-V battery has been demonstrated. Microplasma background emission in the spectral range between 200 and 850 nm obtained using a portable, fiber-optic spectrometer is reported. Analyte emission from microliter volumes of dilute single-element standard solutions of Cd, Cu, K, Li, Mg, Mn, Na, Pb, and Zn is documented. Element-dependent precision was between 10-25% (the average was 15%) and detection limits ranged between 1.5 and 350 ng. The system was used for the determination of Na in diluted bottled-water samples.

LOGICAL REASONING ABILITY AND STUDENT PERFORMANCE IN GENERAL CHEMISTRY.

Science.gov (United States)

Bird, Lillian

2010-03-01

Logical reasoning skills of students enrolled in General Chemistry at the University of Puerto Rico in Río Piedras were measured using the Group Assessment of Logical Thinking (GALT) test. The results were used to determine the students' cognitive level (concrete, transitional, formal) as well as their level of performance by logical reasoning mode (mass/volume conservation, proportional reasoning, correlational reasoning, experimental variable control, probabilistic reasoning and combinatorial reasoning). This information was used to identify particular deficiencies and gender effects, and to determine which logical reasoning modes were the best predictors of student performance in the general chemistry course. Statistical tests to analyze the relation between (a) operational level and final grade in both semesters of the course; (b) GALT test results and performance in the ACS General Chemistry Examination; and (c) operational level and student approach (algorithmic or conceptual) towards a test question that may be answered correctly using either strategy, were also performed.

Some applications of radiation chemistry to biochemistry and radiobiology

International Nuclear Information System (INIS)

Wardman, P.

1987-01-01

In this chapter illustrate the use of radiation chemistry as a tool in investigating biologically important radical reactions, and also outline some studies of models for radiobiological damage. Because aqueous solutions usually offer the most important matrix, an appreciation of the main features of water radiolysis will be essential. Most of the illustrations involve pulse radiolysis, and some familiarity with chemical kinetics is assumed. In addition to these and other chapters in this book, readers find the proceedings of a recent NATO Advanced Study Institute most useful. The authors shall not try to review here all the applications of radiation chemistry to biochemistry and biology, but they will illustrate, using selected examples, the main principles and practical advantages and problems. Another recent volume covers the main contributions of flash photolysis and pulse radiolysis to the chemistry of biology and medicine, complementing earlier reviews. Papers from symposia on radical processes in radiobiology and carcinogenesis, and on super-oxide dismutases, and proceedings of recent international congresses of radiation research, together with the other publications referred to above will enable the reader to gain a comprehensive overview of the role of radicals in biological processes and the contributions of radiation chemistry

Applicative chemistry of tanning metallic heterocomplexes

CERN Document Server

Gaidau, Carmen

2013-01-01

The chemistry of heterocomplex compounds is a fascinating field for experts in chemical synthesis and structural analysis, and for technologists specializing in leather processing. This volume describes the vast theoretical and practical possibilities of exploiting the action synergism of metals with different collagen cross-linking capacity. The possibility of reducing chromium content from leather tanning agents by replacing it with other tanning metals has significant environmental implications and minimum changes in terms of quality and production costs of natural leather, and is a viable

The Compositional Variation of Microindentation Induced Densified and Plastic Deformation Volumes in Simple Silicate Glasses

DEFF Research Database (Denmark)

Hermansen, Christian; Matsuoka, Jun; Yoshida, Satoshi

2012-01-01

The densification and plastic deformation occurring in glass subjected to microindentation are established as two independent deformation mechanisms, and thought to be intimately linked to the concept of hardness and crack nucleation (quantified by the load at which radial cracks nucleate at half...

Mechanically equivalent elastic-plastic deformations and the problem of plastic spin

Directory of Open Access Journals (Sweden)

Steigmann David J.

2011-01-01

Full Text Available The problem of plastic spin is phrased in terms of a notion of mechanical equivalence among local intermediate configurations of an elastic/ plastic crystalline solid. This idea is used to show that, without further qualification, the plastic spin may be suppressed at the constitutive level. However, the spin is closely tied to an underlying undistorted crystal lattice which, once specified, eliminates the freedom afforded by mechanical equivalence. As a practical matter a constitutive specification of plastic spin is therefore required. Suppression of plastic spin thus emerges as merely one such specification among many. Restrictions on these are derived in the case of rate-independent response.

Polímeros biodegradáveis - uma solução parcial para diminuir a quantidade dos resíduos plásticos Biodegradable polymers - a partial way for decreasing the amount of plastic waste

Directory of Open Access Journals (Sweden)

Sandra Mara Martins Franchetti

2006-07-01

Full Text Available The large use of plastics has generated a waste deposit problem. Today plastic wastes represent 20% in volume of the total waste in the municipal landfills. To solve the disposal problem of plastics methods have been employed such as incineration, recycling, landfill disposal, biodegradation and the use of biodegradable polymers. Incineration of plastic wastes provokes pollution due to the production of poisonous gases. Recycling is important to reduce final costs of plastic materials, but is not enough in face of the amount of discarded plastic. In landfills plastic wastes remain undegraded for a long time, causing space and pollution problems. Biodegradation is a feasible method to treat some plastics, but intensive research is necessary to find conditions for the action of microorganisms. All of these methods are important and the practical application of each one depends on the type and amount of the plastic wastes and the environmental conditions. Therefore, a great deal of research has focused on developing biodegradable plastics and its application because it is an important way for minimizing the effect of the large volume of plastic waste discarded in the world.

Plastics and health risks.

Science.gov (United States)

Halden, Rolf U

2010-01-01

By 2010, the worldwide annual production of plastics will surpass 300 million tons. Plastics are indispensable materials in modern society, and many products manufactured from plastics are a boon to public health (e.g., disposable syringes, intravenous bags). However, plastics also pose health risks. Of principal concern are endocrine-disrupting properties, as triggered for example by bisphenol A and di-(2-ethylhexyl) phthalate (DEHP). Opinions on the safety of plastics vary widely, and despite more than five decades of research, scientific consensus on product safety is still elusive. This literature review summarizes information from more than 120 peer-reviewed publications on health effects of plastics and plasticizers in lab animals and humans. It examines problematic exposures of susceptible populations and also briefly summarizes adverse environmental impacts from plastic pollution. Ongoing efforts to steer human society toward resource conservation and sustainable consumption are discussed, including the concept of the 5 Rs--i.e., reduce, reuse, recycle, rethink, restrain--for minimizing pre- and postnatal exposures to potentially harmful components of plastics.

Recycling of plastic waste: Presence of phthalates in plastics from households and industry

DEFF Research Database (Denmark)

Pivnenko, Kostyantyn; Eriksen, Marie Kampmann; Martín-Fernández, J. A.

2016-01-01

recognised, the influence of plastic recycling on phthalate content has been hypothesised but not well documented. In the present work we analysed selected phthalates (DMP, DEP, DPP, DiBP, DBP, BBzP, DEHP, DCHP and DnOP) in samples of waste plastics as well as recycled and virgin plastics. DBP, DiBP and DEHP...... product manufacturing (labelling, gluing, etc.) and were not removed following recycling of household waste plastics. Furthermore, DEHP was identified as a potential indicator for phthalate contamination of plastics. Close monitoring of plastics intended for phthalates-sensitive applications...

Antiplasticization and plasticization of Matrimid® asymmetric hollow fiber membranes. Part B. Modeling

KAUST Repository

Lee, Jong Suk; Madden, William; Koros, William J.

2010-01-01

A previous paper characterized effects of exposure of Matrimid® asymmetric fibers to either toluene or n-heptane or a combination of both contaminants during permeation. In all cases, reductions in the carbon dioxide permeance and the carbon dioxide/methane selectivity were observed for both annealed and non-annealed samples. In this paper, the respective potential impacts of competitive sorption, fiber compaction, and antiplasticization/plasticization on membrane performance during contaminant exposure are quantified and analyzed. The combined impact of competitive sorption and antiplasticization/plasticization are shown to account for the loss in membrane performance observed during exposure to highly sorbing feed stream contaminants. The dual mode transport model for penetrant mixtures was used to explain reduction in CO2 permeance due to competitive sorption effects, while free volume-based modeling explained decrease in CO2 permeance due to antiplasticization. Finally, the impact on CO2 permeance during exposure of the annealed Matrimid® fibers to contaminants is analyzed. The analysis is based on reduction in segmental mobility expected due to reduction of residual unrelaxed volume as compared to unanealed sample. © 2010.

Antiplasticization and plasticization of Matrimid® asymmetric hollow fiber membranes. Part B. Modeling

KAUST Repository

Lee, Jong Suk

2010-03-15

A previous paper characterized effects of exposure of Matrimid® asymmetric fibers to either toluene or n-heptane or a combination of both contaminants during permeation. In all cases, reductions in the carbon dioxide permeance and the carbon dioxide/methane selectivity were observed for both annealed and non-annealed samples. In this paper, the respective potential impacts of competitive sorption, fiber compaction, and antiplasticization/plasticization on membrane performance during contaminant exposure are quantified and analyzed. The combined impact of competitive sorption and antiplasticization/plasticization are shown to account for the loss in membrane performance observed during exposure to highly sorbing feed stream contaminants. The dual mode transport model for penetrant mixtures was used to explain reduction in CO2 permeance due to competitive sorption effects, while free volume-based modeling explained decrease in CO2 permeance due to antiplasticization. Finally, the impact on CO2 permeance during exposure of the annealed Matrimid® fibers to contaminants is analyzed. The analysis is based on reduction in segmental mobility expected due to reduction of residual unrelaxed volume as compared to unanealed sample. © 2010.

Chemistry and physics

International Nuclear Information System (INIS)

Broerse, J.J.; Barendsen, G.W.; Kal, H.B.; Kogel, A.J. van der

1983-01-01

This book contains the extended abstracts of the contributions of the poster workshop sessions on chemistry and physics of the 7th international congress of radiation research. They cover the following main topics: primary processes in radiation physics and chemistry, general chemistry in radiation chemistry, DNA and model systems in radiation chemistry, molecules of biological interest in radiation chemistry, techniques in radiation chemistry, hot atom chemistry. refs.; figs.; tabs

Fiscal 1999 survey report. Part 2. Research study on restraint of carbon dioxide generation by green chemistry; 1999 nendo green chemistry ni yoru CO{sub 2} hassei yokusei ni kakawaru chosa kenkyu. 2

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-01

In connection with green chemistry, a concept of bringing paradigm shift to chemical technologies as something that makes reduction in environmental load compatible with economic activities; surveys were made this year on the developments of fine chemicals from renewable resources such as cellulose among the cases of developing chemical substances/products to be called 'green chemicals' reducing environmental load; developments of surfactants produced by certain microorganism, plastic additives with reduced pollutant loads, particularly fire retardants and environmentally benign reactant solvents; concept of green chemistry in the development of chlorofluorocarbon-alternatives; and up-to-date technological level concerning a design method of chemical materials and an estimation method for chemical safety using quantum chemistry calculation. In regard to the chemical materials and products intrinsically containing a certain level of risk, R and D should be reinforced and accelerated in the future on the alternative materials/products reducing their toxicity. In this case, along with the importance of discussing compatibility of technological possibility with economical adaptability, sociological study seems to be necessary in incorporating environmental load reduction into economic evaluation. (NEDO)

Size effects in olivine control strength in low-temperature plasticity regime

Science.gov (United States)

Kumamoto, K. M.; Thom, C.; Wallis, D.; Hansen, L. N.; Armstrong, D. E. J.; Goldsby, D. L.; Warren, J. M.; Wilkinson, A. J.

2017-12-01

The strength of the lithospheric mantle during deformation by low-temperature plasticity controls a range of geological phenomena, including lithospheric-scale strain localization, the evolution of friction on deep seismogenic faults, and the flexure of tectonic plates. However, constraints on the strength of olivine in this deformation regime are difficult to obtain from conventional rock-deformation experiments, and previous results vary considerably. We demonstrate via nanoindentation that the strength of olivine in the low-temperature plasticity regime is dependent on the length-scale of the test, with experiments on smaller volumes of material exhibiting larger yield stresses. This "size effect" has previously been explained in engineering materials as a result of the role of strain gradients and associated geometrically necessary dislocations in modifying plastic behavior. The Hall-Petch effect, in which a material with a small grain size exhibits a higher strength than one with a large grain size, is thought to arise from the same mechanism. The presence of a size effect resolves discrepancies among previous experimental measurements of olivine, which were either conducted using indentation methods or were conducted on polycrystalline samples with small grain sizes. An analysis of different low-temperature plasticity flow laws extrapolated to room temperature reveals a power-law relationship between length-scale (grain size for polycrystalline deformation and contact radius for indentation tests) and yield strength. This suggests that data from samples with large inherent length scales best represent the plastic strength of the coarse-grained lithospheric mantle. Additionally, the plastic deformation of nanometer- to micrometer-sized asperities on fault surfaces may control the evolution of fault roughness due to their size-dependent strength.

Challenges in plastics recycling

DEFF Research Database (Denmark)

Pivnenko, Kostyantyn; Jakobsen, L. G.; Eriksen, Marie Kampmann

2015-01-01

Recycling of waste plastics still remains a challenging area in the waste management sector. The current and potential goals proposed on EU or regional levels are difficult to achieve, and even to partially fullfil them the improvements in collection and sorting should be considerable. A study...... was undertaken to investigate the factors affecting quality in plastics recycling. The preliminary results showed factors primarily influencing quality of plastics recycling to be polymer cross contamination, presence of additives, non-polymer impurities, and polymer degradation. Deprivation of plastics quality......, with respect to recycling, has been shown to happen throughout the plastics value chain, but steps where improvements may happen have been preliminary identified. Example of Cr in plastic samples analysed showed potential spreading and accumulation of chemicals ending up in the waste plastics. In order...

The effect of high school chemistry instruction on students' academic self-concept

Science.gov (United States)

Morgan, Peter Wallace

The purpose of this study was to investigate the effect of extended instruction in high school chemistry on the academic self-concept of students and determine what parts of the learning experience need to be addressed to make the interaction a more positive one. Fifty-seven students from three metropolitan public schools, who were enrolled in college preparatory chemistry classes, were asked to complete a written instrument, before and after extended chemistry instruction, that measures academic self-concept. Twenty-one of the students who took part in the written task volunteered to answer some in-depth interview questions concerning their academic self-concept and its relationship to chemistry instruction. Student responses, instrument scores, and student chemistry grades were analyzed for a variety of chemistry learning--academic self-concept connections and interactions. Results showed that there was a positive interaction for less than half of the students involved in the interview sessions. The results from the written instrument showed similar findings. Comparing chemistry grades and academic self-concept revealed an uncertain connection between the two, especially for students with strong academic self-concepts. Students felt that the laboratory experience was often disconnected from the remainder of chemistry instruction and recommended that the laboratory experience be integrated with classroom work. Students also expressed concerns regarding the volume of algorithmic mathematical calculations associated with college preparatory chemistry instruction. Results of this study suggest that secondary chemistry instruction must become more aware of the affective domain of learning and develop a mindful awareness of its connection to the cognitive domain if chemistry teaching and learning is going to better facilitate the intellectual growth of secondary students.

Individual differences in behavioural plasticities.

Science.gov (United States)

Stamps, Judy A

2016-05-01

Interest in individual differences in animal behavioural plasticities has surged in recent years, but research in this area has been hampered by semantic confusion as different investigators use the same terms (e.g. plasticity, flexibility, responsiveness) to refer to different phenomena. The first goal of this review is to suggest a framework for categorizing the many different types of behavioural plasticities, describe examples of each, and indicate why using reversibility as a criterion for categorizing behavioural plasticities is problematic. This framework is then used to address a number of timely questions about individual differences in behavioural plasticities. One set of questions concerns the experimental designs that can be used to study individual differences in various types of behavioural plasticities. Although within-individual designs are the default option for empirical studies of many types of behavioural plasticities, in some situations (e.g. when experience at an early age affects the behaviour expressed at subsequent ages), 'replicate individual' designs can provide useful insights into individual differences in behavioural plasticities. To date, researchers using within-individual and replicate individual designs have documented individual differences in all of the major categories of behavioural plasticities described herein. Another important question is whether and how different types of behavioural plasticities are related to one another. Currently there is empirical evidence that many behavioural plasticities [e.g. contextual plasticity, learning rates, IIV (intra-individual variability), endogenous plasticities, ontogenetic plasticities) can themselves vary as a function of experiences earlier in life, that is, many types of behavioural plasticity are themselves developmentally plastic. These findings support the assumption that differences among individuals in prior experiences may contribute to individual differences in behavioural

Nanotechnology and regenerative therapeutics in plastic surgery: The next frontier.

Science.gov (United States)

Tan, Aaron; Chawla, Reema; G, Natasha; Mahdibeiraghdar, Sara; Jeyaraj, Rebecca; Rajadas, Jayakumar; Hamblin, Michael R; Seifalian, Alexander M

2016-01-01

The rapid ascent of nanotechnology and regenerative therapeutics as applied to medicine and surgery has seen an exponential rise in the scale of research generated in this field. This is evidenced not only by the sheer volume of papers dedicated to nanotechnology but also in a large number of new journals dedicated to nanotechnology and regenerative therapeutics specifically to medicine and surgery. Aspects of nanotechnology that have already brought benefits to these areas include advanced drug delivery platforms, molecular imaging and materials engineering for surgical implants. Particular areas of interest include nerve regeneration, burns and wound care, artificial skin with nanoelectronic sensors and head and neck surgery. This study presents a review of nanotechnology and regenerative therapeutics, with focus on its applications and implications in plastic surgery. Copyright © 2015 British Association of Plastic, Reconstructive and Aesthetic Surgeons. All rights reserved.

Durability of wood plastic composites manufactured from recycled plastic

Directory of Open Access Journals (Sweden)

Irina Turku

2018-03-01

Full Text Available The influence of accelerated weathering, xenon-arc light and freeze-thaw cycling on wood plastic composites extruded from a recycled plastic was studied. The results showed that, in general, weathering had a stronger impact on samples made from plastic waste compared to a sample made from virgin material. After weathering, the mechanical properties, tensile and flexural, were reduced by 2–30%, depending on the plastic source. Wettability of the samples was shown to play a significant role in their stability. Chemical analysis with infrared spectroscopy and surface observation with a scan electron microscope confirmed the mechanical test results. Incorporation of carbon black retained the properties during weathering, reducing the wettability of the sample, diminishing the change of mechanical properties, and improving color stability. Keywords: Environmental science, Mechanical engineering, Materials science

Phenotypic plasticity, costs of phenotypes, and costs of plasticity

DEFF Research Database (Denmark)

Callahan, Hilary S; Maughan, Heather; Steiner, Uli

2008-01-01

Why are some traits constitutive and others inducible? The term costs often appears in work addressing this issue but may be ambiguously defined. This review distinguishes two conceptually distinct types of costs: phenotypic costs and plasticity costs. Phenotypic costs are assessed from patterns...... of covariation, typically between a focal trait and a separate trait relevant to fitness. Plasticity costs, separable from phenotypic costs, are gauged by comparing the fitness of genotypes with equivalent phenotypes within two environments but differing in plasticity and fitness. Subtleties associated with both...... types of costs are illustrated by a body of work addressing predator-induced plasticity. Such subtleties, and potential interplay between the two types of costs, have also been addressed, often in studies involving genetic model organisms. In some instances, investigators have pinpointed the mechanistic...

Plastic waste as a resource. Strategies for reduction and utilization of plastic waste

OpenAIRE

Pasqual i Camprubí, Gemma

2010-01-01

Plastic materials have experienced a spectacular rate of growth in recent decades, consequently, production of plastics, and likewise their consumption, has increased markedly since 1950. Moreover, they are lightweight and durable, as well as can be moulded into a variety of products that can be manufactured in many different types of plastic and in a wide range of applications. Inevitably, continually increasing amounts of used plastic are originating daily, resulting in a plastic waste prob...

Plasticity of an Amorphous Assembly of Elastic Gel Beads

Science.gov (United States)

Grosshans, D.; Knaebel, A.; Lequeux, F.

1995-01-01

We have studied the rheological properties of an assembly of swollen gel beads in a lack of solvent. The system is an amorphous assembly of packed soft spheres in a given volume. We have studied the plastic behavior of the system, and interpreted it in terms of bead rearrangements within the assembly. Nous avons étudié les propriétés rhéologiques d'un assemblage de billes de gel gonflées en défaut de solvant. Le système est donc une assemblée amorphe de sphères molles écrasées à volume total constant. Nous avons étudié divers aspects du comportement plastique et nous l'avons interprété en termes de réorganisations de billes dans l'assemblage.

Thermal degradation and plasticizing mechanism of poly(vinyl chloride) plasticized with a novel cardanol derived plasticizer

Science.gov (United States)

Chen, J.; Nie, X. A.; Jiang, J. C.; Zhou, Y. H.

2018-01-01

A natural plasticizer cardanol derivatives glycidyl ether (CGE) was synthesized and employed as a plasticizer for the poly(vinyl chloride). The effect of CGE on thermal degradation of PVC films and its plasticizing mechanism were firstly reported. The molecular structure of CGE was characterized with Fourier transform infrared spectroscopy (FTIR). Thermal properties, degradation properties and compatibility of the PVC films were investigated by Differential scanning calorimeter analysis (DSC), Thermogravimetric analysis (TGA) and FTIR, respectively. Compared with the commercial plasticizers dioctylphthalate (DOP), CGE can endow PVC film with a decrease of 4.31 °C in glass transition temperature (Tg), an increase of 24.01 °C and 25.53 °C in 10% weight loss (T 10) and 50% weight loss (T 50) respectively, and a higher activetion energy of thermal degradation (Ea ).

From hot atom chemistry to epithermal chemistry

International Nuclear Information System (INIS)

Roessler, K.

2004-01-01

The rise and fall of hot atom chemistry (HAC) over the years from 1934 to 2004 is reviewed. Several applications are discussed, in particular to astrophysics and the interaction of energetic ions and atoms in space. Epithermal chemistry (ETC) is proposed to substitute the old name, since it better fits the energy range as well as the non-thermal and non-equilibrium character of the reactions. ETC also avoids the strong connexion of HAC to nuclear chemistry and stands for the opening of the field to physical chemistry and astrophysics. (orig.)

Mathematical Chemistry

OpenAIRE

Trinajstić, Nenad; Gutman, Ivan

2002-01-01

A brief description is given of the historical development of mathematics and chemistry. A path leading to the meeting of these two sciences is described. An attempt is made to define mathematical chemistry, and journals containing the term mathematical chemistry in their titles are noted. In conclusion, the statement is made that although chemistry is an experimental science aimed at preparing new compounds and materials, mathematics is very useful in chemistry, among other things, to produc...

The Hugoniot and chemistry of ablator plastic below 100 GPa

Energy Technology Data Exchange (ETDEWEB)

Akin, M. C., E-mail: akin1@llnl.gov; Fratanduono, D. E.; Chau, R. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

2016-01-28

The equation of state of glow discharge polymer (GDP) was measured to high precision using the two-stage light gas gun at Lawrence Livermore National Laboratory at pressures up to 70 GPa. Both absolute measurements and impedance matching techniques were used to determine the principal and secondary Hugoniots. GDP likely reacts at about 30 GPa, demonstrated by specific emission at 450 nm coupled with changes to the Hugoniot and reshock points. As a result of these reactions, the shock pressure in GDP evolves in time, leading to a possible decrease in pressure as compression increases, or negative compressibility, and causing complex pressure profiles within the plastic. Velocity wave profile variation was observed as a function of position on each shot, suggesting some internal variation of GDP may be present, which would be consistent with previous observations. The complex temporal and possibly structural evolution of GDP under shock compression suggests that calculations of compression and pressure based upon bulk or mean measurements may lead to artificially low pressures and high compressions. Evidence for this includes a large shift in calculating reshock pressures based on the reflected Hugoniot. These changes also suggest other degradation mechanisms for inertial confinement fusion implosions.

Mixed plastics recycling technology

CERN Document Server

Hegberg, Bruce

1995-01-01

Presents an overview of mixed plastics recycling technology. In addition, it characterizes mixed plastics wastes and describes collection methods, costs, and markets for reprocessed plastics products.

Basketball training increases striatum volume.

Science.gov (United States)

Park, In Sung; Lee, Kea Joo; Han, Jong Woo; Lee, Nam Joon; Lee, Won Teak; Park, Kyung Ah; Rhyu, Im Joo

2011-02-01

The striatum is associated with the learning and retention of motor skills. Several studies have shown that motor learning induces neuronal changes in the striatum. We investigated whether macroscopic change in striatum volume occurs in a segment of the human population who learned basketball-related motor skills and practiced them throughout their entire athletic life. Three-dimensional magnetic resonance imaging volumetry was performed in basketball players and healthy controls, and striatum volumes were compared based on basketball proficiency, region and side. We identified morphological enlargement in the striatum of basketball players in comparison with controls. Our results suggest that continued practice and repetitive performance of basketball-related motor skills may induce plastic structural changes in the human striatum. Copyright © 2010 Elsevier B.V. All rights reserved.

Sub-nanosecond plastic scintillators

International Nuclear Information System (INIS)

Lyons, P.B.; Caldwell, S.E.; Hocker, L.P.; Crandall, D.G.; Zagarino, P.A.; Cheng, J.; Tirsell, G.; Hurlbut, C.R.

1977-01-01

Quenched plastic scintillators have been developed that yield much faster short decay components and greatly reduced long decay components compared to conventional plastic scintillators. The plastics are produced through the addition of selected quench agents to NE111 plastic scintillator that result in reduced total light output. Eight different agents have been studied. Benzophenone and piperidine are two of the most effective quench agents. Data are presented both for short and long decay components. The plastics are expected to make significant contributions in areas of plasma diagnostics

Sub-nanosecond plastic scintillators

International Nuclear Information System (INIS)

Lyons, P.B.; Caldwell, S.E.; Hocker, L.P.; Crandall, D.G.; Zagarino, P.A.; Cheng, J.; Tirsell, G.; Hurlbut, C.R.

1976-01-01

Quenched plastic scintillators have been developed that yield much faster short decay components and greatly reduced long decay components compared to conventional plastic scintillators. The plastics are produced through the addition of selected quench agents to NE111 plastic scintillator that result in reduced total light output. Eight different agents have been studied. Benzophenone and piperidine are two of the most effective quench agents. Data are presented both for short and long decay components. The plastics are expected to make significant contributions in areas of plasma diagnostics

DMS cyclone separation processes for optimization of plastic wastes recycling and their implications.

Science.gov (United States)

Gent, Malcolm Richard; Menendez, Mario; Toraño, Javier; Torno, Susana

2011-06-01

It is demonstrated that substantial reductions in plastics presently disposed of in landfills can be achieved by cyclone density media separation (DMS). In comparison with the size fraction of plastics presently processed by industrial density separations (generally 6.4 to 9.5 mm), cyclone DMS methods are demonstrated to effectively process a substantially greater range of particle sizes (from 0.5 up to 120 mm). The purities of plastic products and recoveries obtained with a single stage separation using a cylindrical cyclone are shown to attain virtually 100% purity and recoveries >99% for high-density fractions and >98% purity and recoveries were obtained for low-density products. Four alternative schemas of multi-stage separations are presented and analyzed as proposed methods to obtain total low- and high-density plastics fraction recoveries while maintaining near 100% purities. The results of preliminary tests of two of these show that the potential for processing product purities and recoveries >99.98% of both density fractions are indicated. A preliminary economic comparison of capital costs of DMS systems suggests cyclone DMS methods to be comparable with other DMS processes even if the high volume capacity for recycling operations of these is not optimized.

Ocean Literacy from kindergarten to secondary school: a vertically articulated curriculum on marine micro-plastics

Science.gov (United States)

Realdon, Giulia; Candussio, Giuliana; Manià, Marinella; Palamin, Serenella

2017-04-01

Marine micro-plastics are a relatively recent issue in research (Thompson et al. 2004), in the media and in education and, due to novelty and relevance, they are a suitable topic for addressing Ocean Literacy within science teaching to different age groups. In fact marine micro-plastics can be used to introduce Ocean Literacy and environmental science, but also traditional science subjects like biology, chemistry and Earth science, with a system approach focused on "understanding the Ocean's influence on humans and human influence on the Ocean". Inspired by the growing public interest for marine micro-plastics and by the lack of specific teaching activities in our country (Italy), we developed a vertically articulated curriculum on micro-plastics for students aged 5-15 years. Our proposal is based on a number of practical activities realized with different language and communication styles to be suitable for different age groups. For younger students (age 5-7) we use drama to address micro-plastics bioaccumulation in marine food chains: children act as fish of different trophic levels who pretend to "eat" micro-plastics models (built from plastic bottles) until the biggest fish is captured and ends up as a "meal" shared by other pupils. Teachers guide the performance and stimulate observations and remarks about the origin of micro-plastics and the correct management of plastic objects. The performance has been documented in a video and presented in a national teacher workshop (3 Giorni per la Scuola, Napoli 2015). For students aged 8-13 we propose observation and manipulation of common household plastic objects, followed by physical/chemical testing of different polymers to understand plastics characteristics that make these materials valuable but troublesome at the same time. Students then observe sand samples, taken from a local beach, containing natural components and man-made fragments (including micro-plastics), so they can directly experience the fate of

Crystal and defect chemistry influences on band gap trends in alkaline earth perovskites

International Nuclear Information System (INIS)

Lee, Soonil; Woodford, William H.; Randall, Clive A.

2008-01-01

A number of perovskites with A-site alkaline earth chemistries being Ca, Sr, and Ba, and tetravalent cations including Ce, Zr, and Ti are measured for optical band gap and found to vary systematically with tolerance factor and lattice volume within limits defined by the chemistry of the octahedral site. This paper also focuses on the BaTiO 3 system, considering equilibrated nonstoichiometries, and determines the changes in band gap with respect to Ba/Ti ratios. It was found that the optical band gap changes in the solid solution regime and is invariant in the second phase regions, as would be expected. In the cases of Ba/Ti 1.0 stoichiometries, there is a distinct Urbach tail and the trend with lattice volume no longer holds. It is inferred that the V Ti q prime-2V O partial Schottky complex controls the band gap trend with Ba-rich nonstoichiometries

Using foreground/background analysis to determine leaf and canopy chemistry

Science.gov (United States)

Pinzon, J. E.; Ustin, S. L.; Hart, Q. J.; Jacquemoud, S.; Smith, M. O.

1995-01-01

Spectral Mixture Analysis (SMA) has become a well established procedure for analyzing imaging spectrometry data, however, the technique is relatively insensitive to minor sources of spectral variation (e.g., discriminating stressed from unstressed vegetation and variations in canopy chemistry). Other statistical approaches have been tried e.g., stepwise multiple linear regression analysis to predict canopy chemistry. Grossman et al. reported that SMLR is sensitive to measurement error and that the prediction of minor chemical components are not independent of patterns observed in more dominant spectral components like water. Further, they observed that the relationships were strongly dependent on the mode of expressing reflectance (R, -log R) and whether chemistry was expressed on a weight (g/g) or are basis (g/sq m). Thus, alternative multivariate techniques need to be examined. Smith et al. reported a revised SMA that they termed Foreground/Background Analysis (FBA) that permits directing the analysis along any axis of variance by identifying vectors through the n-dimensional spectral volume orthonormal to each other. Here, we report an application of the FBA technique for the detection of canopy chemistry using a modified form of the analysis.

A molecular dynamics approach for predicting the glass transition temperature and plasticization effect in amorphous pharmaceuticals.

Science.gov (United States)

Gupta, Jasmine; Nunes, Cletus; Jonnalagadda, Sriramakamal

2013-11-04

The objectives of this study were as follows: (i) To develop an in silico technique, based on molecular dynamics (MD) simulations, to predict glass transition temperatures (Tg) of amorphous pharmaceuticals. (ii) To computationally study the effect of plasticizer on Tg. (iii) To investigate the intermolecular interactions using radial distribution function (RDF). Amorphous sucrose and water were selected as the model compound and plasticizer, respectively. MD simulations were performed using COMPASS force field and isothermal-isobaric ensembles. The specific volumes of amorphous cells were computed in the temperature range of 440-265 K. The characteristic "kink" observed in volume-temperature curves, in conjunction with regression analysis, defined the Tg. The MD computed Tg values were 367 K, 352 K and 343 K for amorphous sucrose containing 0%, 3% and 5% w/w water, respectively. The MD technique thus effectively simulated the plasticization effect of water; and the corresponding Tg values were in reasonable agreement with theoretical models and literature reports. The RDF measurements revealed strong hydrogen bond interactions between sucrose hydroxyl oxygens and water oxygen. Steric effects led to weak interactions between sucrose acetal oxygens and water oxygen. MD is thus a powerful predictive tool for probing temperature and water effects on the stability of amorphous systems during drug development.

Time between plastic displacements of elasto-plastic oscillators subject to Gaussian white noise

DEFF Research Database (Denmark)

Tarp-Johansen, Niels Jacob; Ditlevsen, Ove Dalager

2001-01-01

A one degree of freedom elasto-plastic oscillator subject to stationary Gaussian white noise has a plastic displacement response process of intermittent character. During shorter or longer time intervals the oscillator vibrates within the elastic domain without undergoing any plastic displacements...... between the clumps of plastic displacements. This is needed for a complete description of the plastic displacement process. A quite accurate fast simulation procedure is presented based on an amplitude model to determine the short waiting times in the transient regime of the elastic vibrations existing...

Mechanical Properties of High Performance Concrete Containing Waste Plastic as Aggregate

Directory of Open Access Journals (Sweden)

Abdulkader Ismail Al-Hadithi

2015-08-01

Full Text Available The world's population growth and the increasing demand for new infrastructure facilities and buildings , present us with the vision of a higher resources consumption, specially in the form of more durable concrete such as High Performance Concrete (HPC . Moreover , the growth of the world pollution by plastic waste has been tremendous. The aim of this research is to investigate the change in mechanical properties of HPC with added waste plastics in concrete. For this purpose 2.5%, 5% and 7.5% in volume of natural fine aggregate in the HPC mixes were replaced by an equal volume of Polyethylene Terephthalate (PET waste , got by shredded PET bottles. The mechanical properties (compressive, splitting tensile, and flexural strength evaluated at the ages of (7 ,28, 56 and 91 days while the static modulus of elasticity tested at (28 and 91 days . The results indicated that HPC containing PET-aggregate presented lower compressive strength and static elasticity . The splitting strength displayed an arising trend at the initial stages, however, they have a tendency to decrease after a while. On the other hand, flexural strength results gave better modulus of rapture at all ages of curing , as compared with reference concrete specimens.

[Application of biodegradable plastic film to reduce plastic film residual pollution in Chinese agriculture].

Science.gov (United States)

Yan, Changrong; He, Wenqing; Xue, Yinghao; Liu, Enke; Liu, Qin

2016-06-25

Plastic film has become an important agriculture production material in recent years. Over the past three decades, the amount and application area of plastic film have increased steadily, and in 2014, which are 1.4 million tons and more than 180 million hm² respectively. It plays a key role for ensuring the supply of agricultural goods in China. Meanwhile, plastic film residual pollution becomes more and more serious, and in some regions, the amount of plastic film residues has reached over 250 kg/hm². In part of the Northwest region, soil structure of farmland has been destroyed by plastic film residues and then crop growth and farming operations were suppressed. It is recognized as a good choice to replace plastic film with biodegradable plastic film, an effective measure to solve the plastic film residue pollution. Now, it is in a critical stage of study and assessment of biodegradable plastic film in China and fortunately some biodegradable plastic films show effects in the production of potatoes, peanuts and tobacco. Overall, a series of challenges has still been faced by the biodegradable plastic film, mainly including improving the quality of biodegradable plastic products, such as tensile strength, flexibility, improving the controllability of rupture and degradation, enhancing the ability of increasing soil temperature and preserving soil moisture, and to satisfy the demand of crops production with mulching. In addition, it is essential to reduce the cost of the biodegradable film and promote the application of biodegradable film on large-scale. With the development of biodegradable plastic technology and agricultural production environment, the application of the biodegradable film will have a good future.

Industrial chemistry engineering

International Nuclear Information System (INIS)

1993-01-01

This book on industrial chemistry engineering is divided in two parts. The first part deals with industrial chemistry, inorganic industrial chemistry, organic industrial chemistry, analytical chemistry and practical questions. The last parts explain the chemical industry, a unit parts and thermodynamics in chemical industry and reference. It reveals the test subjects for the industrial chemistry engineering with a written examination and practical skill.

Advanced chemistry management system to optimize BWR chemistry control

International Nuclear Information System (INIS)

Maeda, K.; Nagasawa, K.

2002-01-01

BWR plant chemistry control has close relationships among nuclear safety, component reliability, radiation field management and fuel integrity. Advanced technology is required to improve chemistry control [1,3,6,7,10,11]. Toshiba has developed TACMAN (Toshiba Advanced Chemistry Management system) to support BWR chemistry control. The TACMAN has been developed as response to utilities' years of requirements to keep plant operation safety, reliability and cost benefit. The advanced technology built into the TACMAN allows utilities to make efficient chemistry control and to keep cost benefit. TACMAN is currently being used in response to the needs for tools those plant chemists and engineers could use to optimize and identify plant chemistry conditions continuously. If an incipient condition or anomaly is detected at early stage, root causes evaluation and immediate countermeasures can be provided. Especially, the expert system brings numerous and competitive advantages not only to improve plant chemistry reliability but also to standardize and systematize know-how, empirical knowledge and technologies in BWR chemistry This paper shows detail functions of TACMAN and practical results to evaluate actual plant. (authors)

Plastic fish

CERN Multimedia

Antonella Del Rosso

2015-01-01

In terms of weight, the plastic pollution in the world’s oceans is estimated to be around 300,000 tonnes. This plastic comes from both land-based and ocean-based sources. A lecture at CERN by chemist Wolfgang Trettnak addressed this issue and highlighted the role of art in raising people’s awareness.   Artwork by Wolfgang Trettnak. Packaging materials, consumer goods (shoes, kids’ toys, etc.), leftovers from fishing and aquaculture activities… our oceans and beaches are full of plastic litter. Most of the debris from beaches is plastic bottles. “PET bottles have high durability and stability,” explains Wolfgang Trettnak, a chemist by education and artist from Austria, who gave a lecture on this topic organised by the Staff Association at CERN on 26 May. “PET degrades very slowly and the estimated lifetime of a bottle is 450 years.” In addition to the beach litter accumulated from human use, rivers bring several ki...

Plastics in the Marine Environment.

Science.gov (United States)

Law, Kara Lavender

2017-01-03

Plastics contamination in the marine environment was first reported nearly 50 years ago, less than two decades after the rise of commercial plastics production, when less than 50 million metric tons were produced per year. In 2014, global plastics production surpassed 300 million metric tons per year. Plastic debris has been detected worldwide in all major marine habitats, in sizes from microns to meters. In response, concerns about risks to marine wildlife upon exposure to the varied forms of plastic debris have increased, stimulating new research into the extent and consequences of plastics contamination in the marine environment. Here, I present a framework to evaluate the current understanding of the sources, distribution, fate, and impacts of marine plastics. Despite remaining knowledge gaps in mass budgeting and challenges in investigating ecological impacts, the increasing evidence of the ubiquity of plastics contamination in the marine environment, the continued rapid growth in plastics production, and the evidence-albeit limited-of demonstrated impacts to marine wildlife support immediate implementation of source-reducing measures to decrease the potential risks of plastics in the marine ecosystem.

Plastics in the Marine Environment

Science.gov (United States)

Law, Kara Lavender

2017-01-01

Plastics contamination in the marine environment was first reported nearly 50 years ago, less than two decades after the rise of commercial plastics production, when less than 50 million metric tons were produced per year. In 2014, global plastics production surpassed 300 million metric tons per year. Plastic debris has been detected worldwide in all major marine habitats, in sizes from microns to meters. In response, concerns about risks to marine wildlife upon exposure to the varied forms of plastic debris have increased, stimulating new research into the extent and consequences of plastics contamination in the marine environment. Here, I present a framework to evaluate the current understanding of the sources, distribution, fate, and impacts of marine plastics. Despite remaining knowledge gaps in mass budgeting and challenges in investigating ecological impacts, the increasing evidence of the ubiquity of plastics contamination in the marine environment, the continued rapid growth in plastics production, and the evidence—albeit limited—of demonstrated impacts to marine wildlife support immediate implementation of source-reducing measures to decrease the potential risks of plastics in the marine ecosystem.

Selection of polychlorinated plastics in plastic waste by X-ray fluorescence method

International Nuclear Information System (INIS)

Kumasaki, H.; Shinozaki, Y.

1979-01-01

The X-ray fluorescence method using a small source of 55 Fe was examined and found to be applicable for the selection of polychlorinated plastics from plastic waste in model areas in Tokyo designated for investigating their content in the waste. The weight ratios of soft and hard polychlorinated plastics to the total plastic waste estimated by this method were found to be 15.6% and 0.29% respectively. These values agree well with the results obtained with the Beilstein method. (author)

Error identification in a high-volume clinical chemistry laboratory: Five-year experience.

Science.gov (United States)

Jafri, Lena; Khan, Aysha Habib; Ghani, Farooq; Shakeel, Shahid; Raheem, Ahmed; Siddiqui, Imran

2015-07-01

Quality indicators for assessing the performance of a laboratory require a systematic and continuous approach in collecting and analyzing data. The aim of this study was to determine the frequency of errors utilizing the quality indicators in a clinical chemistry laboratory and to convert errors to the Sigma scale. Five-year quality indicator data of a clinical chemistry laboratory was evaluated to describe the frequency of errors. An 'error' was defined as a defect during the entire testing process from the time requisition was raised and phlebotomy was done until the result dispatch. An indicator with a Sigma value of 4 was considered good but a process for which the Sigma value was 5 (i.e. 99.977% error-free) was considered well controlled. In the five-year period, a total of 6,792,020 specimens were received in the laboratory. Among a total of 17,631,834 analyses, 15.5% were from within hospital. Total error rate was 0.45% and of all the quality indicators used in this study the average Sigma level was 5.2. Three indicators - visible hemolysis, failure of proficiency testing and delay in stat tests - were below 5 on the Sigma scale and highlight the need to rigorously monitor these processes. Using Six Sigma metrics quality in a clinical laboratory can be monitored more effectively and it can set benchmarks for improving efficiency.

Toxicological Threats of Plastic

Science.gov (United States)

Plastics pose both physical (e.g., entanglement, gastrointestinal blockage, reef destruction) and chemical threats (e.g., bioaccumulation of the chemical ingredients of plastic or toxic chemicals sorbed to plastics) to wildlife and the marine ecosystem.

Antioxidant-Conjugated Onto Gamma-Generated Chitosan Nanoparticle for Radiation Sterilized Medical Plastic

Energy Technology Data Exchange (ETDEWEB)

Pasaphan, W. [Department of Applied Radiation and Isotopes, Faculty of Science Kasetsart University, Bangkok (Thailand)

2009-07-01

The Department of Applied Radiation and Isotopes, Faculty of Science, Kasetsart University, Bangkok, Thailand, mainly gives the course of study in the field of radiation and nuclear science and technology. The research actitivies relevant to the department are about nuclear instrument and analytical technique by nuclear methodology, radiation chemistry and processing technology, and radiation biology and agriculture. My work going on in the department is separated into two main responsibilities, i.e. (i) teaching courses and (ii) research activity. For (i), in the present time, there are 5 courses (i.e., radiation detection technique, radiation health protection, nuclear method of analysis, radioistope tracer techniques in biology and seminar) for bachelor degree and 4 courses (radiation chemistry and processing, radiation detection and dosimetry, nuclear facilities and utilization, research method in applied radiation and isotope) for master degree. In the case of (ii), my research interests head on the radiation chemistry and processing applicable to material and nanomaterial development for industrial applications, e.g. nanofilter and metal absorbent material; for medical applications, e.g. bio-additive for medical material, nanoparticle for drug delivery system, radiosensitizer for radiotherapy; for agricultural applications, e.g. pest controlled compound and plastic. The researches are also attended to biopolymer especially chitin-chiosan including functional polymer. The material for radiation dosimeter based on EPR is furthermore interesting to look for.

Antioxidant-Conjugated Onto Gamma-Generated Chitosan Nanoparticle for Radiation Sterilized Medical Plastic

International Nuclear Information System (INIS)

Pasaphan, W.

2009-01-01

The Department of Applied Radiation and Isotopes, Faculty of Science, Kasetsart University, Bangkok, Thailand, mainly gives the course of study in the field of radiation and nuclear science and technology. The research actitivies relevant to the department are about nuclear instrument and analytical technique by nuclear methodology, radiation chemistry and processing technology, and radiation biology and agriculture. My work going on in the department is separated into two main responsibilities, i.e. (i) teaching courses and (ii) research activity. For (i), in the present time, there are 5 courses (i.e., radiation detection technique, radiation health protection, nuclear method of analysis, radioistope tracer techniques in biology and seminar) for bachelor degree and 4 courses (radiation chemistry and processing, radiation detection and dosimetry, nuclear facilities and utilization, research method in applied radiation and isotope) for master degree. In the case of (ii), my research interests head on the radiation chemistry and processing applicable to material and nanomaterial development for industrial applications, e.g. nanofilter and metal absorbent material; for medical applications, e.g. bio-additive for medical material, nanoparticle for drug delivery system, radiosensitizer for radiotherapy; for agricultural applications, e.g. pest controlled compound and plastic. The researches are also attended to biopolymer especially chitin-chiosan including functional polymer. The material for radiation dosimeter based on EPR is furthermore interesting to look for

Current organic chemistry

National Research Council Canada - National Science Library

1997-01-01

Provides in depth reviews on current progress in the fields of asymmetric synthesis, organometallic chemistry, bioorganic chemistry, heterocyclic chemistry, natural product chemistry, and analytical...

Plasticity and beyond microstructures, crystal-plasticity and phase transitions

CERN Document Server

Hackl, Klaus

2014-01-01

The book presents the latest findings in experimental plasticity, crystal plasticity, phase transitions, advanced mathematical modeling of finite plasticity and multi-scale modeling. The associated algorithmic treatment is mainly based on finite element formulations for standard (local approach) as well as for non-standard (non-local approach) continua and for pure macroscopic as well as for directly coupled two-scale boundary value problems. Applications in the area of material design/processing are covered, ranging from grain boundary effects in polycrystals and phase transitions to deep-drawing of multiphase steels by directly taking into account random microstructures.

Vegetative and reproductive evaluation of hot peppers under different plastic mulches in poly/plastic tunnel

International Nuclear Information System (INIS)

Iqbal, Q.; Amjad, M.; Ahmad, R.

2009-01-01

Since the beginning of civilization, the man has developed technologies to increase the efficiency of food production. The use of plastic mulch in commercial vegetable production is one of these traditional techniques that have been used for centuries. Studies were conducted to assess the efficacy of plastic mulch on growth and yield of two hot pepper hybrids, viz. Sky Red and Maha in poly/plastic tunnel. The treatments were black plastic mulch, clear plastic mulch and bare soil as control. Both hot pepper hybrids mulched with black plastic showed significantly better vegetative growth (plant height, leaf area etc) and fruit yield. Clear plastic mulch significantly increased soil temperature and reduced the number of days to first flower than black plastic mulch and bare soil. However, fruit yield was higher by 39.56 and 36.49% respectively in both hybrids when they were grown on black and clear plastic mulch as compared to bare soil. Overall results indicated that the use of plastic mulch is an ideal option to maximize hot pepper productivity as well as to extend their production season in poly/plastic tunnels. (author)

Aquatic Chemistry

International Nuclear Information System (INIS)

Kim, Dong Yeun; Kim, Oh Sik; Kim, Chang Guk; Park, Cheong Gil; Lee, Gwi Hyeon; Lee, Cheol Hui

1987-07-01

This book deals aquatic chemistry, which treats water and environment, chemical kinetics, chemical balance like dynamical characteristic, and thermodynamics, acid-base chemistry such as summary, definition, kinetics, and PH design for mixture of acid-base chemistry, complex chemistry with definition, and kinetics, precipitation and dissolution on summary, kinetics of precipitation and dissolution, and balance design oxidation and resolution with summary, balance of oxidation and resolution.

Combinatorial chemistry

DEFF Research Database (Denmark)

Nielsen, John

1994-01-01

An overview of combinatorial chemistry is presented. Combinatorial chemistry, sometimes referred to as `irrational drug design,' involves the generation of molecular diversity. The resulting chemical library is then screened for biologically active compounds.......An overview of combinatorial chemistry is presented. Combinatorial chemistry, sometimes referred to as `irrational drug design,' involves the generation of molecular diversity. The resulting chemical library is then screened for biologically active compounds....

Forensic Chemistry

Science.gov (United States)

Bell, Suzanne

2009-07-01

Forensic chemistry is unique among chemical sciences in that its research, practice, and presentation must meet the needs of both the scientific and the legal communities. As such, forensic chemistry research is applied and derivative by nature and design, and it emphasizes metrology (the science of measurement) and validation. Forensic chemistry has moved away from its analytical roots and is incorporating a broader spectrum of chemical sciences. Existing forensic practices are being revisited as the purview of forensic chemistry extends outward from drug analysis and toxicology into such diverse areas as combustion chemistry, materials science, and pattern evidence.

Chemistry-nuclear chemistry division. Progress report, October 1979-September 1980

International Nuclear Information System (INIS)

Ryan, R.R.

1981-05-01

This report presents the research and development programs pursued by the Chemistry-Nuclear Chemistry Division of the Los Alamos National Laboratory. Topics covered include advanced analytical methods, atmospheric chemistry and transport, biochemistry, biomedical research, element migration and fixation, inorganic chemistry, isotope separation and analysis, atomic and molecular collisions, molecular spectroscopy, muonic x rays, nuclear cosmochemistry, nuclear structure and reactions, radiochemical separations, theoretical chemistry, and unclassified weapons research

Chemistry-nuclear chemistry division. Progress report, October 1979-September 1980

Energy Technology Data Exchange (ETDEWEB)

Ryan, R.R. (comp.)

1981-05-01

This report presents the research and development programs pursued by the Chemistry-Nuclear Chemistry Division of the Los Alamos National Laboratory. Topics covered include advanced analytical methods, atmospheric chemistry and transport, biochemistry, biomedical research, element migration and fixation, inorganic chemistry, isotope separation and analysis, atomic and molecular collisions, molecular spectroscopy, muonic x rays, nuclear cosmochemistry, nuclear structure and reactions, radiochemical separations, theoretical chemistry, and unclassified weapons research.

Interaction between vegetable oil based plasticizer molecules and polyvinyl chloride, and their plasticization effect

Science.gov (United States)

Haryono, Agus; Triwulandari, Evi; Jiang, Pingping

2017-01-01

Plasticizer molecules are low molecular weight compounds that are widely used in polymer industries especially in polyvinyl chloride (PVC) resin. As an additive in PVC resin, the important role of plasticizer molecules is to improve the flexibility and processability of PVC by lowering the glass transition temperature (Tg). However, the commercial plasticizer like di(2-ethylhexyl)phthalate (DEHP) is known to cause liver cancer, at least in laboratory rats. DEHP can leach out from PVC into blood, certain drug solutions and fatty foods, which has been detected in the bloodstream of patients undergoing transfusion. Vegetable oil based plasticizers have some attractive properties such as non-toxic, bio-degradable, good heat and light stability, renewable resources, and environmentally friendly. Here we discussed the main results and development of vegetable oil based plasticizer, and especially palm oil based plasticizer. The interaction between plasticizer and polymer was discussed from the properties of the plasticized polymeric material.

Black hole chemistry: thermodynamics with Lambda

International Nuclear Information System (INIS)

Kubizňák, David; Mann, Robert B; Teo, Mae

2017-01-01

We review recent developments on the thermodynamics of black holes in extended phase space, where the cosmological constant is interpreted as thermodynamic pressure and treated as a thermodynamic variable in its own right. In this approach, the mass of the black hole is no longer regarded as internal energy, rather it is identified with the chemical enthalpy. This leads to an extended dictionary for black hole thermodynamic quantities; in particular a notion of thermodynamic volume emerges for a given black hole spacetime. This volume is conjectured to satisfy the reverse isoperimetric inequality—an inequality imposing a bound on the amount of entropy black hole can carry for a fixed thermodynamic volume. New thermodynamic phase transitions naturally emerge from these identifications. Namely, we show that black holes can be understood from the viewpoint of chemistry, in terms of concepts such as Van der Waals fluids, reentrant phase transitions, and triple points. We also review the recent attempts at extending the AdS/CFT dictionary in this setting, discuss the connections with horizon thermodynamics, applications to Lifshitz spacetimes, and outline possible future directions in this field. (topical review)

Free radicals in biology. Volume II

International Nuclear Information System (INIS)

Pryor, W.A.

1976-01-01

This volume continues the treatment of topics in free radical biology and free radical pathology from Volume I. In the first chapter, pyridinyl radicals, radicals which are models for those derived from NAD, are discussed. Pyridinyl radicals can be synthesized and isolated and directly studied in a number of chemical systems. The next chapter treats the role of glutathione in the cell. It is becoming even more apparent that this vital thiol controls a large number of important cellular functions. The GSH/GSSG balance has recently been implicated as a control for cellular development; this balance also may be important in relaying the effects of oxidants from one site to another in the body. The next chapter outlines the reactions of singlet oxygen; some of these involve free radicals and some do not. This reactive intermediate appears to be important both in photochemical smog and in cellular chemistry where singlet oxygen is produced by nonphotochemical processes. The production of free radicals from dry tissues, a controversial area with conflicting claims is reviewed. The next chapter outlines the current status of the studies of photochemical smog. The next two chapters treat specific reactive materials which are present in smog. The first discusses the chemistry of nitrogen oxides and ozone. The second chapter treats the chemistry of the peroxyacyl nitrites. These compounds, although present in only small concentration, are among the most toxic components of smog. The last two chapters treat radiation damage to proteins and radiation protection and radical reactions produced by radiation in nucleic acids

Outline of investigation on restraint of carbon dioxide generation by green chemistry. 1999.1-1999.3; 1998 nendo green chemistry ni yoru CO2 hassei yokusei ni kakawaru chosa kenkyu chosa hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-03-01

Investigations were conducted into the above in some leading OECD (Organization for Economic Cooperation and Development) member states. Green chemistry is a new concept in which clean technology, environment-friendly chemistry, and the like are combined, and is a chemical solution for reducing or stopping the use or generation of materials, products, by-products, solvents, reagents, etc., which are dangerous to health and environments, throughout the whole life cycle of chemicals covering the processes of their designing, manufacturing, dumping, and recycling. In this fiscal year, the actual state of the generation of biomass, regarded as representative of reproducible materials, and its feasibility as chemical resources were investigated. In an effort at finding out chemical reactions safer to health and causing less environmental impact, investigations were also conducted into the recent trends of catalysts, novel reactions for organic syntheses, use of supercritical fluids, photocatalysts, biomimetic processes, etc. The development of substitutes for plastic additives was also studied. Since acceptance by the citizenry is quite important for green chemistry to take effect, educating and enlightening activities in the U.S., Britain, France, and Germany were inquired into. (NEDO)

The Brazilian medicinal chemistry from 1998 to 2008 in the Journal of Medicinal Chemistry, Bioorganic and Medicinal Chemistry, Bioorganic and Medicinal Chemistry Letters and European Journal of Medicinal Chemistry [A química medicinal brasileira de 1998 a 2008 nos periódicos Journal of Medicinal Chemistry, Bioorganic and Medicinal Chemistry, Bioorganic and Medicinal Chemistry Letters e European Journal of Medicinal Chemistry

OpenAIRE

Bárbara Vasconcellos da Silva; Renato Saldanha Bastos; Angelo da Cunha Pinto

2009-01-01

In this article we present the Brazilian publications, the research groups involved, the contributions per states and the main diseases studied from 1998 to 2008 in the following periodicals: Journal of Medicinal Chemistry, Bioorganic and Medicinal Chemistry, Bioorganic and Medicinal Chemistry Letters and European Journal of Medicinal Chemistry.

Evaluation of the BD BACTEC FX blood volume monitoring system as a continuous quality improvement measure.

Science.gov (United States)

Coorevits, L; Van den Abeele, A-M

2015-07-01

The yield of blood cultures is proportional to the volume of blood cultured. We evaluated an automatic blood volume monitoring system, recently developed by Becton Dickinson within its BACTEC EpiCenter module, that calculates mean volumes of negative aerobic bottles and generates boxplots and histograms. First, we evaluated the filling degree of 339 aerobic glass blood cultures by calculating the weight-based volume for each bottle. A substantial amount of the bottles (48.3%) were inadequately filled. Evaluation of the accuracy of the monitoring system showed a mean bias of -1.4 mL (-15.4%). Additional evaluation, using the amended software on 287 aerobic blood culture bottles, resulted in an acceptable mean deviation of -0.3 mL (-3.3%). The new software version was also tested on 200 of the recently introduced plastic bottles, which will replace the glass bottles in the near future, showing a mean deviation of +2.8 mL (+26.7%). In conclusion, the mean calculated volumes can be used for the training of a single phlebotomist. However, filling problems appear to be masked when using them for phlebotomist groups or on wards. Here, visual interpretation of boxplots and histograms can serve as a useful tool to observe the spread of the filling degrees and to develop a continuous improvement program. Re-adjustment of the software has proven to be necessary for use with plastic bottles. Due to our findings, BD has developed further adjustments to the software for validated use with plastic bottles, which will be released soon.

Handbook of Plastic Welding

DEFF Research Database (Denmark)

Islam, Aminul

The purpose of this document is to summarize the information about the laser welding of plastic. Laser welding is a matured process nevertheless laser welding of micro dimensional plastic parts is still a big challenge. This report collects the latest information about the laser welding of plastic...... materials and provides an extensive knowhow on the industrial plastic welding process. The objectives of the report include: - Provide the general knowhow of laser welding for the beginners - Summarize the state-of-the-art information on the laser welding of plastics - Find the technological limits in terms...... of design, materials and process - Find the best technology, process and machines adaptive to Sonion’s components - Provide the skills to Sonion’s Design Engineers for successful design of the of the plastic components suitable for the laser welding The ultimate goal of this report is to serve...

Abiotic degradation of plastic films

Science.gov (United States)

Ángeles-López, Y. G.; Gutiérrez-Mayen, A. M.; Velasco-Pérez, M.; Beltrán-Villavicencio, M.; Vázquez-Morillas, A.; Cano-Blanco, M.

2017-01-01

Degradable plastics have been promoted as an option to mitigate the environmental impacts of plastic waste. However, there is no certainty about its degradability under different environmental conditions. The effect of accelerated weathering (AW), natural weathering (NW) and thermal oxidation (TO) on different plastics (high density polyethylene, HDPE; oxodegradable high density polyethylene, HDPE-oxo; compostable plastic, Ecovio ® metalized polypropylene, PP; and oxodegradable metalized polypropylene, PP-oxo) was studied. Plastics films were exposed to AW per 110 hours; to NW per 90 days; and to TO per 30 days. Plastic films exposed to AW and NW showed a general loss on mechanical properties. The highest reduction in elongation at break on AW occurred to HDPE-oxo (from 400.4% to 20.9%) and was higher than 90% for HDPE, HDPE-oxo, Ecovio ® and PP-oxo in NW. No substantial evidence of degradation was found on plastics exposed to TO. Oxo-plastics showed higher degradation rates than their conventional counterparts, and the compostable plastic was resistant to degradation in the studied abiotic conditions. This study shows that degradation of plastics in real life conditions will vary depending in both, their composition and the environment.

Plasticity characteristic obtained by indentation

International Nuclear Information System (INIS)

Mil'man, Yu.V.; Chugunova, S.I.; Goncharova, I.V.

2011-01-01

Methods for determination plasticity characteristic δH in the measurement of hardness and nanohardness are considered. Parameter δH characterizes the plasticity of a material by the part of plastic deformation in the total elastic-plastic deformation. The value of δH is defined for metals with different types of crystal lattice, covalent and partially covalent crystals, intermetallics, metallic glasses and quasicrystals. It is discussed the dependence of the plasticity characteristic δH on structural factors and temperature. Parameter δH allows to analyze and compare the plasticity of materials which are brittle at standard mechanical tests. The combination of hardness H, as the strength characteristic, and the plasticity characteristic δH makes possible the better characterization of mechanical behavior of materials than only the hardness H. The examples of plasticity characteristic δH application are represented.

Lunar Science Conference, 4th, Houston, Tex., March 5-8, 1973, Proceedings. Volume 1 - Mineralogy and petrology. Volume 2 - Chemical and isotope analyses. Organic chemistry. Volume 3 - Physical properties

Science.gov (United States)

Gose, W. A.

1973-01-01

The mineralogy, petrology, chemistry, isotopic composition, and physical properties of lunar materials are described in papers detailing methods, results, and implications of research on samples returned from eight lunar landing sites: Apollo 11, 12, 14, 15, 16, 17, and Luna 16 and 20. The results of experiments conducted or set up on the lunar surface by the astronauts are also described along with observations taken from Command Modules and subsatellites. Major topics include general geology, soil and breccia studies, petrologic studies, mineralogic analyses, elemental compositions, radiometric age determinations, rare gas chemistry, radionuclides, organogenic compounds, particle track records, thermal properties, seismic studies, resonance studies, orbital mapping, lunar atmosphere, magnetic studies, electrical studies, optical properties, and microcratering. Individual items are announced in this issue.

Bad chemistry

OpenAIRE

Petsko, Gregory A

2004-01-01

General chemistry courses haven't changed significantly in forty years. Because most basic chemistry students are premedical students, medical schools have enormous influence and could help us start all over again to create undergraduate chemistry education that works.

Experiments with elasto-plastic oscillator

DEFF Research Database (Denmark)

Randrup-thomsen, Søren; Ditlevsen, Ove Dalager

1996-01-01

Plastic displacements of a Gaussian white noise excited three degrees of freedom non-ideal elasto-plastic oscillator are measured in laboratory experiments and the plastic displacements are compared to computer simulated results for the corresponding ideal elasto-plastic oscillator. The comparative...

Experiments with elasto-plastic oscillator

DEFF Research Database (Denmark)

Randrup-Thomsen, S.; Ditlevsen, Ove Dalager

1999-01-01

Plastic displacements of a Gaussian white noise excited three degrees of freedom non-ideal elasto-plastic oscillator are measured in laboratory experiments and the plastic displacements are compared to computer simulated results for the corresponding ideal elasto-plastic oscillator. The comparative...

Handbook on the physics and chemistry of rare earths

International Nuclear Information System (INIS)

Gschneidner, K.A. Jr.; Eyring, L.

1982-01-01

This handbook is a six-volume work which covers the entire rare earth field in an integrated manner. Each chapter is a comprehensive, up-to-date, critical review of a particular segment of the field. The first volume is devoted to the rare earth metals, the second to rare earth alloys and intermetallics, and the third and fourth volumes to the non-metallic rare earth materials, including solutions, complexes and bioinorganic substances, in addition to solid inorganic compounds. The electronic structure of these unique elements is the primary basis of understanding their physical, metallurgical and chemical natures. The interrelationship of the 4f and valence electrons and the observed optical, electrical, magnetic, crystallographic, elastic, thermal, mechanical, chemical, geochemical and biological behaviors is brought forth time and again throughout the chapters. Also discussed are the preparative, separation and solution chemistry of the elements and their compounds and the various chemical and physical analytical methods for determining the rare earths in various materials and impurities in a rare earth matrix. Vol. 5 is a update complement of the previous volumes. Volume 6 is concerned with ternary and higher order materials. (Auth.)

Analysis of plastic residues in maple sap and syrup collected from tubing systems sanitized with isopropyl alcohol

Directory of Open Access Journals (Sweden)

Luc Lagacé

2017-05-01

Full Text Available A plastic tubing system operated under vacuum is usually used to collect sap from maple trees during spring time to produce maple syrup. This system is commonly sanitized with isopropyl alcohol (IPA to remove microbial contamination colonizing the system during the sugar season. Questions have been raised whether IPA would contribute to the leaching of plastic residues in maple sap and syrup coming from sanitized systems. First, an extraction experiment was performed in the lab on commercial plastic tubing materials that were submitted to IPA under harsh conditions. The results of the GC-MS analysis revealed the presence of many compounds that served has target for further tests. Secondly, tests were done on early and mid-season maple sap and syrup coming from many sugarbushes using IPA or not to determine potential concentrations of plastic residues. Results obtained from sap and syrup samples showed that no quantifiable (< 1–75 μg/L concentration of any plastic molecules tested was determined in all samples coming from IPA treated or not treated systems. However, some samples of first sap run used as a rinse solution to be discarded before the season start and that were coming from non sanitized or IPA sanitized systems, showed quantifiable concentrations of chemical residue such as ultraviolet protector (octabenzone. These results show that IPA can be safely used to sanitize maple sap collection system in regards to the leaching of plastic residues in maple sap and syrup and reinforced the need to thoroughly rinse the tubing system at the beginning of the season for both sanitized and non sanitized systems. Keywords: Food science, Food safety, Materials chemistry

ENVIRONMENTAL ISSUE-PLASTIC

OpenAIRE

Sunita Shakle

2017-01-01

Polythene is the most common plastic, the annual global production is approximately 60 million tones, and its primary use is in packing. Plastic bags pollute soil and waters and kill thousands of marine generalize plastic bags are not biodegradable they clog water ways, spoil the land scape and end up in landfills. Where they may take 1000 year or more to break down into ever smaller particals that continue to pollution the soil and water.

Positronium chemistry

CERN Document Server

Green, James

1964-01-01

Positronium Chemistry focuses on the methodologies, reactions, processes, and transformations involved in positronium chemistry. The publication first offers information on positrons and positronium and experimental methods, including mesonic atoms, angular correlation measurements, annihilation spectra, and statistical errors in delayed coincidence measurements. The text then ponders on positrons in gases and solids. The manuscript takes a look at the theoretical chemistry of positronium and positronium chemistry in gases. Topics include quenching, annihilation spectrum, delayed coincidence

The Sensitivity of Arctic Ozone Loss to Polar Stratospheric Cloud Volume and Chlorine and Bromine Loading in a Chemistry and Transport Model

Science.gov (United States)

Douglass, A. R.; Stolarski, R. S.; Strahan, S. E.; Polansky, B. C.

2006-01-01

The sensitivity of Arctic ozone loss to polar stratospheric cloud volume (V(sub PSC)) and chlorine and bromine loading is explored using chemistry and transport models (CTMs). A simulation using multi-decadal output from a general circulation model (GCM) in the Goddard Space Flight Center (GSFC) CTM complements one recycling a single year s GCM output in the Global Modeling Initiative (GMI) CTM. Winter polar ozone loss in the GSFC CTM depends on equivalent effective stratospheric chlorine (EESC) and polar vortex characteristics (temperatures, descent, isolation, polar stratospheric cloud amount). Polar ozone loss in the GMI CTM depends only on changes in EESC as the dynamics repeat annually. The GSFC CTM simulation reproduces a linear relationship between ozone loss and Vpsc derived from observations for 1992 - 2003 which holds for EESC within approx.85% of its maximum (approx.1990 - 2020). The GMI simulation shows that ozone loss varies linearly with EESC for constant, high V(sub PSC).

Formation and Dimerization of NO2 A General Chemistry Experiment

Science.gov (United States)

Hennis, April D.; Highberger, C. Scott; Schreiner, Serge

1997-11-01

We have developed a general chemistry experiment which illustrates Gay-Lussac's law of combining volumes. Students are able to determine the partial pressures and equilibrium constant for the formation and dimerization of NO2. The experiment can be carried out in about 45 minutes with students working in groups of two. The experiment readily provides students with data that can be manipulated with a common spreadsheet.

Nano-Ceramic Coated Plastics

Science.gov (United States)

Cho, Junghyun

2013-01-01

Plastic products, due to their durability, safety, and low manufacturing cost, are now rapidly replacing cookware items traditionally made of glass and ceramics. Despite this trend, some still prefer relatively expensive and more fragile ceramic/glassware because plastics can deteriorate over time after exposure to foods, which can generate odors, bad appearance, and/or color change. Nano-ceramic coatings can eliminate these drawbacks while still retaining the advantages of the plastic, since the coating only alters the surface of the plastic. The surface coating adds functionality to the plastics such as self-cleaning and disinfectant capabilities that result from a photocatalytic effect of certain ceramic systems. These ceramic coatings can also provide non-stick surfaces and higher temperature capabilities for the base plastics without resorting to ceramic or glass materials. Titanium dioxide (TiO2) and zinc oxide (ZnO) are the candidates for a nano-ceramic coating to deposit on the plastics or plastic films used in cookware and kitchenware. Both are wide-bandgap semiconductors (3.0 to 3.2 eV for TiO2 and 3.2 to 3.3 eV for ZnO), so they exhibit a photocatalytic property under ultraviolet (UV) light. This will lead to decomposition of organic compounds. Decomposed products can be easily washed off by water, so the use of detergents will be minimal. High-crystalline film with large surface area for the reaction is essential to guarantee good photocatalytic performance of these oxides. Low-temperature processing (nano-ceramic coatings (TiO2, ZnO) on plastic materials (silicone, Teflon, PET, etc.) that can possess both photocatalytic oxide properties and flexible plastic properties. Processing cost is low and it does not require any expensive equipment investment. Processing can be scalable to current manufacturing infrastructure.

FTIR Spectroscopic and DC Ionic conductivity Studies of PVDF-HFP: LiBF4: EC Plasticized Polymer Electrolyte Membrane

Science.gov (United States)

Sangeetha, M.; Mallikarjun, A.; Jaipal Reddy, M.; Siva Kumar, J.

2017-08-01

In the present paper; the FTIR and Temperature dependent DC Ionic conductivity studies of polymer (80 Wt% PVDF-HFP) with inorganic lithium tetra fluoroborate salt (20 Wt% LiBF4) as ionic charge carrier and plasticized with various weight ratios of Ethylene carbonate plasticizer (10 Wt% to 70 Wt% EC) as gel polymer electrolytes. Solution casting method is used for the preparation of plasticized polymer-salt electrolyte films. FTIR analysis shows the good complexation between PVDF-HFP: LiBF4 and the presence of functional groups in the plasticized polymer-salt electrolyte membrane. Also the analysis and results show that the highest DC ionic conductivity of 1.66 × 10-3 SCm -1 was found at 373 K for a particular concentration of 80 Wt% PVDF-HFP: 20 Wt% LiBF4: 40 Wt% EC porous gel type polymer-salt plasticized porous membrane. Increase of temperature results expansion and segmental motion of polymer chain that generates free volume in turn promotes hopping of the lithium ions satisfying Vogel-Tammann-Fulcher equation.

Non-thermally activated chemistry

International Nuclear Information System (INIS)

Stiller, W.

1987-01-01

The subject is covered under the following headings: state-of-the art of non-thermally activated chemical processes; basic phenomena in non-thermal chemistry including mechanochemistry, photochemistry, laser chemistry, electrochemistry, photo-electro chemistry, high-field chemistry, magneto chemistry, plasma chemistry, radiation chemistry, hot-atom chemistry, and positronium and muonium chemistry; elementary processes in non-thermal chemistry including nuclear chemistry, interactions of electromagnetic radiations, electrons and heavy particles with matter, ionic elementary processes, elementary processes with excited species, radicalic elementary processes, and energy-induced elementary processes on surfaces and interfaces; and comparative considerations. An appendix with historical data and a subject index is given. 44 figs., 41 tabs., and 544 refs

Effect of Exhaust Gas Recirculation on Performance of a Diesel Engine Fueled with Waste Plastic Oil / Diesel Blends

Directory of Open Access Journals (Sweden)

Punitharani K.

2017-11-01

Full Text Available NOx emission is one of the major sources for health issues, acid rain and global warming. Diesel engine vehicles are the major sources for NOx emissions. Hence there is a need to reduce the emissions from the engines by identifying suitable techniques or by means of alternate fuels. The present investigation deals with the effect of Exhaust Gas Recirculation (EGR on 4S, single cylinder, DI diesel engine using plastic oil/Diesel blends P10 (10% plastic oil & 90% diesel in volume, P20 and P30 at various EGR rates. Plastic oil blends were able to operate in diesel engines without any modifications and the results showed that P20 blend had the least NOx emission quantity.

Elastic-plastic analysis of AS4/PEEK composite laminate using a one-parameter plasticity model

Science.gov (United States)

Sun, C. T.; Yoon, K. J.

1992-01-01

A one-parameter plasticity model was shown to adequately describe the plastic deformation of AS4/PEEK (APC-2) unidirectional thermoplastic composite. This model was verified further for unidirectional and laminated composite panels with and without a hole. The elastic-plastic stress-strain relations of coupon specimens were measured and compared with those predicted by the finite element analysis using the one-parameter plasticity model. The results show that the one-parameter plasticity model is suitable for the analysis of elastic-plastic deformation of AS4/PEEK composite laminates.

Pulmonary functions in plastic factory workers: a preliminary study.

Science.gov (United States)

Khaliq, Farah; Singh, Pawan; Chandra, Prakash; Gupta, Keshav; Vaney, Neelam

2011-01-01

Exposure to long term air pollution in the work environment may result in decreased lung functions and various other health problems. A significant occupational hazard to lung functions is experienced by plastic factory workers. The present study is planned to assess the pulmonary functions of workers in the plastic factory where recycling of pastic material was done. These workers were constantly exposed to fumes of various chemicals throughout the day. Thirty one workers of plastic factory were assessed for their pulmonary functions. Parameters were compared with 31 age and sex matched controls not exposed to the same environment. The pulmonary function tests were done using Sibelmed Datospir 120 B portable spirometer. A significant decrease in most of the flow rates (MEF 25%, MEF 50%, MEF 75% and FEF 25-75%) and most of the lung volumes and capacities (FVC, FEV1, VC, TV, ERV, MVV) were observed in the workers. Smoking and duration of exposure were not affecting the lung functions as the non smokers also showed a similar decrement in pulmonary functions. Similarly the workers working for less than 5 years also had decrement in pulmonary functions indicating that their lungs are being affected even if they have worked for one year. Exposure to the organic dust in the work environment should be controlled by adequate engineering measures, complemented by effective personal respiratory protection.

Performance of molded plastic scintillators

International Nuclear Information System (INIS)

Gen, N.S.; Leman, V.E.; Solomonov, V.M.

1989-01-01

The performance of molded plastic scintillators is studied. The plastic scintillators studied were formed by transfer molding and intrusion from a scintillation composition consisting of polystyrene and a standard system of luminescent additives: 2 mass % of paraterphenyl + 0.06 mass % 1,4-di-/2-[5-phenyloxazoyly]/benzene and a plasticizer. The combined effect of mechanical load and temperature was studied. The effect of radiation on molded plastic scintillators was studied using gamma radiation from a 60 Co source. The studies show that the main operating characteristics of molded plastic scintillators are on a par with those of polymerized plastic scintillators. At the same time, molded plastic scintillators are superior in thermal stability at temperatures below the glass transition temperature and with respect to their working temperature range

Plastic food packaging and health

Directory of Open Access Journals (Sweden)

Raika Durusoy

2011-02-01

Full Text Available Plastics have a wide usage in our daily lives. One of their uses is for food packaging and food containers. The aim of this review is to introduce different types of chemicals that can leach from food packaging plastics into foods and cause human exposure and to mention their effects on health. The types of plastics were reviewed under the 13 headings in Turkish Codex Alimentarius and plastics recycling symbols were provided to enable the recognition of the type of plastic when applicable. Chemicals used during the production and that can cause health risks are investigated under the heading of the relevant type of plastic. The most important chemicals from plastic food packaging that can cause toxicity are styrene, 1,3-butadiene, melamine, formaldehyde, acrylamide, di-2-ethylhexyl phthalate, di-2-ethylhexyl adipate, vinyl chloride and bisphenol A. These chemicals have endocrine disrupting, carcinogenic and/or development disrupting effects. These chemicals may leach into foods depending on the chemical properties of the plastic or food, temperature during packaging, processing and storage, exposure to UV and duration of storage. Contact with fatty/oily or acidic foods, heating of the food inside the container, or drinking hot drinks from plastic cups, use of old and scratched plastics and some detergents increase the risk of leaching. The use of plastic containers and packaging for food and beveradges should be avoided whenever possible and when necessary, less harmful types of plastic should be preferred. [TAF Prev Med Bull 2011; 10(1.000: 87-96

Our plastic age

OpenAIRE

Thompson, Richard C.; Swan, Shanna H.; Moore, Charles J.; vom Saal, Frederick S.

2009-01-01

Within the last few decades, plastics have revolutionized our daily lives. Globally we use in excess of 260 million tonnes of plastic per annum, accounting for approximately 8 per cent of world oil production. In this Theme Issue of Philosophical Transactions of the Royal Society, we describe current and future trends in usage, together with the many benefits that plastics bring to society. At the same time, we examine the environmental consequences resulting from the accumulation of waste pl...

Liquefied natural gas as a transportation fuel for heavy-duty trucks: Volume I

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-12-01

This document contains Volume 1 of a three-volume manual designed for use with a 2- to 3-day liquefied natural gas (LNG) training course. Transportation and off-road agricultural, mining, construction, and industrial applications are discussed. This volume provides a brief introduction to the physics and chemistry of LNG; an overview of several ongoing LNG projects, economic considerations, LNG fuel station technology, LNG vehicles, and a summary of federal government programs that encourage conversion to LNG.

A Conservative Formulation for Plasticity

Science.gov (United States)

1992-01-01

concepts that apply to a broad class of macroscopic models: plastic deformation and plastic flow rule. CONSERVATIVE PLASTICITY 469 3a. Plastic Defrrnation...temperature. We illustrate these concepts with a model that has been used to describe high strain-rate plastic flow in metals [11, 31, 32]. In the case...JOURDREN, AND P. VEYSSEYRE. Un Modele ttyperelastique- Plastique Euldrien Applicable aux Grandes Dtformations: Que/ques R~sultats 1-D. preprint, 1991. 2. P

Green chemistry: A tool in Pharmaceutical Chemistry

OpenAIRE

Smita Talaviya; Falguni Majumdar

2012-01-01

Green chemistry expresses an area of research developing from scientific discoveries about pollution awareness and it utilizes a set of principles that reduces or eliminates the use or generation of hazardous substances in all steps of particular synthesis or process. Chemists and medicinal scientists can greatly reduce the risk to human health and the environment by following all the valuable principles of green chemistry. The most simple and direct way to apply green chemistry in pharmaceut...

Wood-plastic combination

International Nuclear Information System (INIS)

Schaudy, R.

1978-02-01

A review on wood-plastic combinations is given including the production (wood and plastic component, radiation hardening, curing), the obtained properties, present applications and prospects for the future of these materials. (author)

The Aesthetic Surgery Literature: Do Plastic Surgeons Remain at the Cutting Edge?

Science.gov (United States)

Dolan, Roisin T; Zins, James E; Morrison, Colin M

2016-07-01

The aesthetic surgery arena has become a competitive marketplace. Recognition as an authority in aesthetic surgery remains a powerful marketing tool for plastic surgeons, but have significant inroads been made by other specialties? The aims of this study were to analyze publication trends relating to the top five most commonly performed aesthetic surgical procedures, and to assess the origins (i.e., source specialty, authorship, institutions, and countries) of published aesthetic surgical research. Based on the seventeenth annual multispecialty data set provided by the American Society for Aesthetic Plastic Surgery, the top five most commonly performed aesthetic surgical procedures were selected. A temporal analysis of publication and citation rates, source institution and country, publishing journal, funding agency trends, and level of evidence was undertaken from 1970 to 2013. Using the search criteria, 7762 articles were identified. There was an 8.8-fold increase in publication volume when the first decade (n = 375) was compared with the last decade (n = 3326). Over the past four decades, 52.2 percent of publications (n = 4053 of 7762) originated from plastic surgery research institutions, with varying contributions from other specialties. Competition was greatest in relation to authorship of blepharoplasty- and rhinoplasty-related publications. Although plastic surgeons continue to maintain a center-stage presence in terms of authorship of aesthetic surgical literature, significant contributions are now made by other specialties. Plastic surgeons must continue to foster high-quality, peer-reviewed research and innovations to maintain their visibility as leaders in the aesthetic surgery literature and sustain a competitive advantage in aesthetic surgery practice.

Plastic deformation and contact area of an elastic-plastic contact of ellipsoid bodies after unloading

NARCIS (Netherlands)

Jamari, Jamari; Schipper, Dirk J.

2007-01-01

This paper presents theoretical and experimental results of the residual or plastic deformation and the plastic contact area of an elastic–plastic contact of ellipsoid bodies after unloading. There are three regime responses of the deformation and contact area: elastic, elastic–plastic and fully

An ideal teaching program of nuclear chemistry in the undergraduate chemistry curriculum

International Nuclear Information System (INIS)

Uenak, T.

2009-01-01

It is well known that several reports on the common educational problems of nuclear chemistry have been prepared by certain groups of experts from time to time. According to very important statements in these reports, nuclear chemistry and related courses generally do not take sufficient importance in undergraduate chemistry curricula and it was generally proposed that nuclear chemistry and related courses should be introduced into undergraduate chemistry curricula at universities worldwide. Starting from these statements, an ideal program in an undergraduate chemistry curriculum was proposed to be introduced into the undergraduate chemistry program at the Department of Chemistry, Ege University, in Izmir, Turkey during the regular updating of the chemistry curriculum. Thus, it has been believed that this Department of Chemistry has recently gained an ideal teaching program in the field of nuclear chemistry and its applications in scientific, industrial, and medical sectors. In this contribution, the details of this program will be discussed. (author)

Dense-body aggregates as plastic structures supporting tension in smooth muscle cells.

Science.gov (United States)

Zhang, Jie; Herrera, Ana M; Paré, Peter D; Seow, Chun Y

2010-11-01

The wall of hollow organs of vertebrates is a unique structure able to generate active tension and maintain a nearly constant passive stiffness over a large volume range. These properties are predominantly attributable to the smooth muscle cells that line the organ wall. Although smooth muscle is known to possess plasticity (i.e., the ability to adapt to large changes in cell length through structural remodeling of contractile apparatus and cytoskeleton), the detailed structural basis for the plasticity is largely unknown. Dense bodies, one of the most prominent structures in smooth muscle cells, have been regarded as the anchoring sites for actin filaments, similar to the Z-disks in striated muscle. Here, we show that the dense bodies and intermediate filaments formed cable-like structures inside airway smooth muscle cells and were able to adjust the cable length according to cell length and tension. Stretching the muscle cell bundle in the relaxed state caused the cables to straighten, indicating that these intracellular structures were connected to the extracellular matrix and could support passive tension. These plastic structures may be responsible for the ability of smooth muscle to maintain a nearly constant tensile stiffness over a large length range. The finding suggests that the structural plasticity of hollow organs may originate from the dense-body cables within the smooth muscle cells.

Laboratory and exterior decay of wood plastic composite boards: voids analysis and computed tomography

Science.gov (United States)

Grace Sun; Rebecca E. Ibach; Meghan Faillace; Marek Gnatowski; Jessie A. Glaeser; John Haight

2016-01-01

After exposure in the field and laboratory soil block culture testing, the void content of wood–plastic composite (WPC) decking boards was compared to unexposed samples. A void volume analysis was conducted based on calculations of sample density and from micro-computed tomography (microCT) data. It was found that reference WPC contains voids of different sizes from...

BWR Water Chemistry Guidelines: 1993 Revision, Normal and hydrogen water chemistry

International Nuclear Information System (INIS)

Karlberg, G.; Goddard, C.; Fitzpatrick, S.

1994-02-01

The goal of water chemistry control is to extend the operating life of the reactor and rector coolant system, balance-of-plant components, and turbines while simultaneously controlling costs to safeguard the continued economic viability of the nuclear power generation investment. To further this goal an industry committee of chemistry personnel prepared guidelines to identify the benefits, risks, and costs associated with water chemistry in BWRs and to provide a template for an optimized water chemistry program. This document replaces the BWR Normal Water Chemistry Guidelines - 1986 Revision and the BWR Hydrogen Water Chemistry Guidelines -- 1987 Revision. It expands on the previous guidelines documents by covering the economic implications of BWR water chemistry control

Precise micropatterning of silver nanoparticles on plastic substrates

International Nuclear Information System (INIS)

Ammosova, Lena; Jiang, Yu; Suvanto, Mika; Pakkanen, Tapani A.

2017-01-01

Highlights: • Silver ink has been deposited on plastic substrate and silver nanoparticles have been produced. • 3D control allows both ink superimposing and deposition on complicated surfaces. • Polyol method ensures the formation of metallic mircopatterns with high uniformity. • Substrate wettability, ink volume, and sintering temperature influences deposited patterns. - Abstract: Conventional fabrication methods to obtain metal patterns on polymer substrates are restricted by high operating temperature and complex preparation steps. The present study demonstrates a simple yet versatile method for preparation of silver nanoparticle micropatterns on polymer substrates with various surface geometry. With the microworking robot technique, we were able not only to directly structure the surface, but also precisely deposit silver nanoparticle ink on the desired surface location with the minimum usage of ink material. The prepared silver nanoparticle ink, containing silver cations and polyethylene glycol (PEG) as a reducing agent, yields silver nanoparticle micropatterns on plastic substrates at low sintering temperature without any contamination. The influence of the ink behaviour was studied, such as substrate wettability, ink volume, and sintering temperature. The ultraviolet visible (UV–vis), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) measurements revealed the formation of micropatterns with uniformly distributed silver nanoparticles. The prepared patterns are expected to have a broad range of applications in optics, medicine, and sensor devices owing to the unique properties of silver. Furthermore, the deposition of a chemical compound, which is different from the substrate material, not only adds a fourth dimension to the prestructured three-dimensional (3D) surfaces, but also opens new application areas to the conventional surface structures.

Precise micropatterning of silver nanoparticles on plastic substrates

Energy Technology Data Exchange (ETDEWEB)

Ammosova, Lena; Jiang, Yu; Suvanto, Mika; Pakkanen, Tapani A., E-mail: tapani.pakkanen@uef.fi

2017-04-15

Highlights: • Silver ink has been deposited on plastic substrate and silver nanoparticles have been produced. • 3D control allows both ink superimposing and deposition on complicated surfaces. • Polyol method ensures the formation of metallic mircopatterns with high uniformity. • Substrate wettability, ink volume, and sintering temperature influences deposited patterns. - Abstract: Conventional fabrication methods to obtain metal patterns on polymer substrates are restricted by high operating temperature and complex preparation steps. The present study demonstrates a simple yet versatile method for preparation of silver nanoparticle micropatterns on polymer substrates with various surface geometry. With the microworking robot technique, we were able not only to directly structure the surface, but also precisely deposit silver nanoparticle ink on the desired surface location with the minimum usage of ink material. The prepared silver nanoparticle ink, containing silver cations and polyethylene glycol (PEG) as a reducing agent, yields silver nanoparticle micropatterns on plastic substrates at low sintering temperature without any contamination. The influence of the ink behaviour was studied, such as substrate wettability, ink volume, and sintering temperature. The ultraviolet visible (UV–vis), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) measurements revealed the formation of micropatterns with uniformly distributed silver nanoparticles. The prepared patterns are expected to have a broad range of applications in optics, medicine, and sensor devices owing to the unique properties of silver. Furthermore, the deposition of a chemical compound, which is different from the substrate material, not only adds a fourth dimension to the prestructured three-dimensional (3D) surfaces, but also opens new application areas to the conventional surface structures.

Chemistry-Nuclear Chemistry Division. Progress report, October 1980-September 1981

International Nuclear Information System (INIS)

Ryan, R.R.

1982-05-01

This report describes major progress in the research and development programs pursued by the Chemistry-Nuclear Chemistry Division of the Los Alamos National Laboratory during FY 1981. Topics covered include advanced analytical methods, atmospheric chemistry and transport, biochemistry, biomedical research, medical radioisotopes research, element migration and fixation, nuclear waste isolation research, inorganic and structural chemistry, isotope separation, analysis and applications, the newly established Nuclear Magnetic Resonance Center, atomic and molecular collisions, molecular spectroscopy, nuclear cosmochemistry, nuclear structure and reactions, pion charge exchange, radiochemical separations, theoretical chemistry, and unclassified weapons research

Chemistry-Nuclear Chemistry Division. Progress report, October 1980-September 1981

Energy Technology Data Exchange (ETDEWEB)

Ryan, R.R. (comp.)

1982-05-01

This report describes major progress in the research and development programs pursued by the Chemistry-Nuclear Chemistry Division of the Los Alamos National Laboratory during FY 1981. Topics covered include advanced analytical methods, atmospheric chemistry and transport, biochemistry, biomedical research, medical radioisotopes research, element migration and fixation, nuclear waste isolation research, inorganic and structural chemistry, isotope separation, analysis and applications, the newly established Nuclear Magnetic Resonance Center, atomic and molecular collisions, molecular spectroscopy, nuclear cosmochemistry, nuclear structure and reactions, pion charge exchange, radiochemical separations, theoretical chemistry, and unclassified weapons research.

Synaptic Plasticity and Nociception

Institute of Scientific and Technical Information of China (English)

ChenJianguo

2004-01-01

Synaptic plasticity is one of the fields that progresses rapidly and has a lot of success in neuroscience. The two major types of synaptie plasticity: long-term potentiation ( LTP and long-term depression (LTD are thought to be the cellular mochanisms of learning and memory. Recently, accumulating evidence suggests that, besides serving as a cellular model for learning and memory, the synaptic plasticity involves in other physiological or pathophysiological processes, such as the perception of pain and the regulation of cardiovascular system. This minireview will focus on the relationship between synaptic plasticity and nociception.

System Chemistry to Control Potential Environmental and Safety Hazards of Recycled Concrete Aggregate With Lead-Based Paint

Science.gov (United States)

2010-01-01

will usually buffer the TCLP test so it would not be classified as a hazardous waste. Acidification of soil does change the chemistry and mobility...crushed concrete product from around the stockpile at Fort Jackson (Figure 8). Each sample of a few kilograms was placed in a plastic “zip-lock...Jackson, rainfall quantity and pH for Columbia, SC first had to be determined. 5.2 Columbia rain data A review of data from National Oceanic and

Japan. Wood-Plastic Composites [Status and technology of polymer-containing fibrous materials in the Eastern Hemisphere

Energy Technology Data Exchange (ETDEWEB)

Hirayama, T. [Central Research Laboratory, Showa Denko K.K., Ota-Ku, Tokyo (Japan)

1968-10-15

Radiation chemistry research has made rapid progress in Japan over the last ten years, and many encouraging results have been obtained with radiation polymerization and graft-polymerization as well as in other fields. Several papers on wood-plastic composites (WPC) have been published in Japanese journals, but very little work on actual applications has been reported. This general review of basic studies and studies of the application of WPC in Japan is divided into three parts: radiation methods, chemical methods (catalyst-heat treatment) and the scope of future research and development.

Progress in organic and physical chemistry structures and mechanisms

CERN Document Server

Zaikov, Gennady E; Lobanov, Anton V

2013-01-01

Progress in Organic and Physical Chemistry: Structures and Mechanisms provides a collection of new research in the field of organic and physical properties, including new research on: The physical principles of the conductivity of electrical conducting polymer compounds The dependence on constants of electromagnetic interactions upon electron spacial-energy characteristics Effects of chitosan molecultural weight on rehological behavior of chitosan modified nanoclay at hight hydrated state Bio-structural energy criteria of functional states in normal and pathological conditions Potentiometric study on the international between devalent cations and sodium carboxylates in aqueous solutions Structural characteristic changes in erythrocyte membranes of mice bearing Alzheimer's-like disease caused by the olfactory bulbetomy This volume is intended to provide an overview of new studies and research for engineers, faculty, researchers, and upper-level students in the field of organic and physical chemistry.

Monitoring of WEEE plastics in regards to brominated flame retardants using handheld XRF

Energy Technology Data Exchange (ETDEWEB)

Aldrian, Alexia, E-mail: alexia.aldrian@unileoben.ac.at [Chair of Waste Processing Technology and Waste Management, Montanuniversitaet Leoben, Franz-Josef-Straße 18, 8700 Leoben (Austria); Ledersteger, Alfred, E-mail: a.ledersteger@saubermacher.at [Saubermacher Dienstleistungs AG, Hans-Roth-Straße 1, 8073 Feldkirchen bei Graz (Austria); Pomberger, Roland, E-mail: roland.pomberger@unileoben.ac.at [Chair of Waste Processing Technology and Waste Management, Montanuniversitaet Leoben, Franz-Josef-Straße 18, 8700 Leoben (Austria)

2015-02-15

Highlights: • Specification of an empirical factor for conversion from bromine to PBB and PBDE. • The handheld XRF device was validated for this particular application. • A very large number of over 4600 pieces of monitor housings was analysed. • The recyclable fraction mounts up to 85% for TV but only 53% of PC waste plastics. • A high percentage of pieces with bromine contents of over 50,000 ppm was obtained. - Abstract: This contribution is focused on the on-site determination of the bromine content in waste electrical and electronic equipment (WEEE), in particular waste plastics from television sets (TV) and personal computer monitors (PC) using a handheld X-ray fluorescence (XRF) device. The described approach allows the examination of samples in regards to the compliance with legal specifications for polybrominated biphenyls (PBBs) and polybrominated diphenyl ethers (PBDEs) directly after disassembling and facilitates the sorting out of plastics with high contents of brominated flame retardants (BFRs). In all, over 3000 pieces of black (TV) and 1600 pieces of grey (PC) plastic waste were analysed with handheld XRF technique for this study. Especially noticeable was the high percentage of pieces with a bromine content of over 50,000 ppm for TV (7%) and PC (39%) waste plastics. The applied method was validated by comparing the data of handheld XRF with results obtained by GC–MS. The results showed the expected and sufficiently accurate correlation between these two methods. It is shown that handheld XRF technique is an effective tool for fast monitoring of large volumes of WEEE plastics in regards to BFRs for on-site measurements.

[Isolation and purification of BMScs of GFP transgenic mouse using the method of adhering to cuture plastic in different time].

Science.gov (United States)

Li, Fu-Qiang; Zhou, Hong-Ying; Yang, Hui-Lun; Xiang, Tao; Mei, Yan; Hu, Huo-Zhen; Wang, Ting-Hua

2006-03-01

To adopt the method of adhering to culture plastic in different time for cultivating and purifying BMSCs of green fluorescent protein (GFP) transgenic mice. Bone marrow cells isolated from GFP transgenic mice are directly planted in culture flask and an exchange of the total volume medium is made at different time. Then the cells adhering to culture plastic are differently counted according to the cell types and are examined by immunohistochemistry using the antibodies of CD44, CD45 and CD54 in three days. Moreover, the cells after the exchange of the total volume medium in 4 hours, 8 hours and 24 hours are selected and successively subcultured down to the fifth passage. Then the result of amplification is calculated and the cells are examined by immunohistochemistry using the antibodies of CD44, CD45 and CD54. With the extending of the time for the first exchange of medium, the density of cells adhering to culture plastic increased accordingly, but the BMSCs proportion decreased. The cells after first exchange of medium in 4 hours had high BMSCs proportion but low BMSCs density, and the cells in 24 hours had high BMSCs density and low BMSCs proportion. However, the cells in 8-10 hours had high BMSCs density and also high BMSCs proportion. The subcultured BMSCs could stably express GFP. The method of adhering to culture plastic in different time for cultivating and purifying BMSCs of GFP transgenic mice is effective. It is suitable to make the first exchange of total volume medium in 8-10 hours. The subcultured cell has the capacity for amplification and will probably be a seed cell for the research of tissue engineering and gene therapy.

Fundamentals of nuclear chemistry

International Nuclear Information System (INIS)

Majer, V.

1982-01-01

The author of the book has had 25 years of experience at the Nuclear Chemistry of Prague Technical University. In consequence, the book is intended as a basic textbook for students of this field. Its main objectives are an easily understandable presentation of the complex subject and in spite of the uncertainty which still characterizes the definition and subjects of nuclear chemistry - a systematic classification and logical structure. Contents: 1. Introduction (history and definition); 2. General nuclear chemistry (physical fundamentals, hot atom chemistry, interaction of nuclear radiation with matter, radioactive elements, isotope effects, isotope exchange, chemistry of radioactive trace elements); 3. Methods of nuclear chemistry of nuclear chemistry (radiochemical methods, activation, separation and enrichment chemistry); 4. Preparative nuclear chemistry (isotope production, labelled compounds); 5. Analytival nuclear chemistry; 6. Applied nuclear chemistry (isotope applications in general physical and analytical chemistry). The book is supplemented by an annex with tables, a name catalogue and a subject index which will facilitate access to important information. (RB) [de

Scientific Information Analysis of Chemistry Dissertations Using Thesaurus of Chemistry

Directory of Open Access Journals (Sweden)

Taghi Rajabi

2017-09-01

Full Text Available : Concept maps of chemistry can be obtained from thesaurus of chemistry. Analysis of information in the field of chemistry is done at graduate level, based on comparing and analyzing chemistry dissertations by using these maps. Therefore, the use of thesaurus for analyzing scientific information is recommended. Major advantage of using this method, is that it is possible to obtain a detailed map of all academic researches across all branches of science. The researches analysis results in chemical science can play a key role in developing strategic research policies, educational programming, linking universities to industries and postgraduate educational programming. This paper will first introduce the concept maps of chemistry. Then, emerging patterns from the concept maps of chemistry will be used to analyze the trend in the academic dissertations in chemistry, using the data collected and stored in our database at Iranian Research Institute for Information Science and Technology (IranDoc over the past 10 years (1998-2009.

Hot Chemistry Laboratory decommissioning activities at IPEN/CNEN-SP, Brazil

International Nuclear Information System (INIS)

Camilo, Ruth L.; Lainetti, Paulo E.O.

2009-01-01

IPEN's fuel cycle activities were accomplished in laboratory and pilot plant scale and most facilities were built in the 70-80 years. Nevertheless, radical changes of the Brazilian nuclear policy in the beginning of 90's determined the interruption of several fuel cycle activities and facilities shutdown. Since then, IPEN has faced the problem of the pilot plants decommissioning considering that there was no experience/expertise in this field at all. In spite of this, some laboratory and pilot plant decommissioning activities have been performed in IPEN in the last years, even without previous experience and training support. One of the first decommissioning activities accomplished in IPEN involved the Hot Chemistry Laboratory. This facility was built in the beginning of the 80's with the proposal of supporting research and development in the nuclear chemistry area. It was decided to settle a new laboratory in the place where the Hot Chemistry Laboratory was installed, being necessary its total releasing from the radioactive contamination point of view. The previous work in the laboratory involved the manipulation of samples of irradiated nuclear fuel, besides plutonium-239 and uranium-233 standard solutions. There were 5 glove-boxes in the facility but only 3 were used with radioactive material. The glove-boxes contained several devices and materials, besides the radioactive compounds, such as: electric and electronic equipment, metallic and plastic pieces, chemical reagents, liquid and solid radioactive wastes, etc. The laboratory's decommissioning process was divided in 12 steps. This paper describes the procedures, problems faced and results related to the Hot Chemistry Laboratory decommissioning operations and its reintegration as a new laboratory of the Chemical and Environmental Technology Center (CQMA) - IPEN-CNEN/SP. (author)

DNA functionalization by dynamic chemistry

Directory of Open Access Journals (Sweden)

Zeynep Kanlidere

2016-10-01

Full Text Available Dynamic combinatorial chemistry (DCC is an attractive method to efficiently generate libraries of molecules from simpler building blocks by reversible reactions under thermodynamic control. Here we focus on the chemical modification of DNA oligonucleotides with acyclic diol linkers and demonstrate their potential for the deoxyribonucleic acid functionalization and generation of libraries of reversibly interconverting building blocks. The syntheses of phosphoramidite building blocks derived from D-threoninol are presented in two variants with protected amino or thiol groups. The threoninol building blocks were successfully incorporated via automated solid-phase synthesis into 13mer oligonucleotides. The amino group containing phosphoramidite was used together with complementary single-strand DNA templates that influenced the Watson–Crick base-pairing equilibrium in the mixture with a set of aldehyde modified nucleobases. A significant fraction of all possible base-pair mismatches was obtained, whereas, the highest selectivity (over 80% was found for the guanine aldehyde templated by the complementary cytosine containing DNA. The elevated occurrence of mismatches can be explained by increased backbone plasticity derived from the linear threoninol building block as a cyclic deoxyribose analogue.

Temperature dependent mechanical properties and thermal activation plasticity of nanocrystalline and coarse grained Ni-18.75 at.% Fe alloy

International Nuclear Information System (INIS)

Tabachnikova, E D; Podolskiy, A V; Smirnov, S N; Psaruk, I A; Liao, P K

2014-01-01

Mechanical properties of Ni-18.75 at.% Fe in coarse grained (average grain size 15 gm) and nanocrystalline (average grain size 22 nm) states were studied in uniaxial compression in the temperature range 4.2-350 K. Temperature dependences of the flow stress, strain rate sensitivity and activation volume of plastic deformation were measured. The thermal activation analysis of the experimental data has been fulfilled for the the plastic deformation value of 2 %. It was shown that plastic deformation in temperature range from 35 to 350 K in both studied structural states has the thermally activated type. Comparative analysis of low temperature thermal activation plastic deformation was carried out for the alloy in coarse grained and nanocrystalline states. Empirical estimates of parameters of the dislocation interaction with local barriers and internal stress value estimates were obtained for the both studied structural states. Analysis of the results indicates that different mechanisms control the thermal activation plasticity of the Ni-18.75 at.% Fe alloy in coarse grained and nanocrystalline states. Possible mechanisms, which control plactisity of the studied states, are disscussed

One-step surface modification for irreversible bonding of various plastics with a poly(dimethylsiloxane) elastomer at room temperature.

Science.gov (United States)

Wu, Jing; Lee, Nae Yoon

2014-05-07

Here, we introduce a simple and facile method for bonding poly(dimethylsiloxane) (PDMS) to various plastics irreversibly via a one-step chemical treatment at room temperature. This was mediated by poly[dimethylsiloxane-co-(3-aminopropyl)methylsiloxane] (amine-PDMS linker), a chemical composed of a PDMS backbone incorporating an amine side group. Room temperature anchoring of the linker was achieved via a reaction between the amine functionality of the linker and the carbon backbone of the plastics, thereby producing urethane bonds. This resulted in the PDMS functionality being exposed on the plastic surface, mimicking the surface properties of bulk PDMS. Following corona treatment of the PDMS-modified plastic and a sheet of PDMS, the two surfaces were placed in contact with each other and heated at 80 °C for 1 h. This resulted in permanent bonding between PDMS and the plastic. To examine the effectiveness of the amine-PDMS linker coating procedure, the surfaces were characterized by measuring water contact angles and by employing X-ray photoelectron spectroscopy (XPS). Polycarbonate (PC), poly(ethylene terephthalate) (PET), poly(vinylchloride) (PVC), and polyimide (PI) were bonded successfully to PDMS using this method, with bond strengths of PC, PET, and PVC with PDMS measured to be approximately 428.5 ± 17.9, 361.7 ± 31.2, and 430.0 ± 14.9 kPa, respectively. The bond strength of a PC-PC homogeneous assembly, also realized using the proposed method, was measured to be approximately 343.9 ± 7.4 kPa. Delamination tests revealed that the PC-PC assembly was able to withstand intense introduction of a liquid whose per-minute injection volume was approximately 278 times greater than the total internal volume of the microchannel fabricated in PC. This demonstrated the robustness of the seal formed using the proposed technique.

Synthesis of biodegradable plastic from tapioca with N-Isopropylacrylamid and chitosan using glycerol as plasticizer

Science.gov (United States)

Syaubari; Safwani, S.; Riza, M.

2018-04-01

One of natural polymers that can be used as raw material in the manufacture of biodegradable plastic is tapioca and chitosan. The addition of other compounds such as glycerol as plasticizer is to improve the characteristics of the plastic that already produced. N- Isopropylacrylamid (NIPAm) is an organic compound that can be synthesized into a polymer or polymer grafting which also biodegradable too. This research aims tostudy the synthesis of biodegradable plastics from tapioca with the addition of chitosan, NIPAm, poly(NIPAm) and analyze the characteristics of biodegradable plastics that already produced. This research was done in three stages, there are (1) polymerization NIPAm, (2) the grafting of chitosan-poly NIPAm and (3) the synthesis of biodegradable plastics from starch mixture with variation of addition chitosan, NIPAm, poly(NIPAm), chitosan-graft-poly(NIPAm) and also variations of glycerol as plasticizer. The results of this research is a thin sheet of plastic which is will get analyzed for the characteristics of functional groups, mechanical, morphological and its biodegradability. FTIR spectra showed the grafting process with the new group formation of CO single-bond at 850 cm-1. Plastic with the addition of NIPAm and 1 ml glycerol has the highest tensile strength value about 31.1 MPa. Plastic with poly(NIPAm) and 4 ml glycerol produces the highest elongation value about 153.72%. Plastic with Chitosan-graft-poly(NIPAm) with 1 ml glycerol has the longest biodegradation because of the small mass-loss for six weeks which is about 6.6%.

New perspectives in plastic biodegradation.

Science.gov (United States)

Sivan, Alex

2011-06-01

During the past 50 years new plastic materials, in various applications, have gradually replaced the traditional metal, wood, leather materials. Ironically, the most preferred property of plastics--durability--exerts also the major environmental threat. Recycling has practically failed to provide a safe solution for disposal of plastic waste (only 5% out of 1 trillion plastic bags, annually produced in the US alone, are being recycled). Since the most utilized plastic is polyethylene (PE; ca. 140 million tons/year), any reduction in the accumulation of PE waste alone would have a major impact on the overall reduction of the plastic waste in the environment. Since PE is considered to be practically inert, efforts were made to isolate unique microorganisms capable of utilizing synthetic polymers. Recent data showed that biodegradation of plastic waste with selected microbial strains became a viable solution. Copyright © 2011 Elsevier Ltd. All rights reserved.

An Insight into Flotation Chemistry of Pyrite with Isomeric Xanthates: A Combined Experimental and Computational Study

Directory of Open Access Journals (Sweden)

Guihong Han

2018-04-01

Full Text Available The flotation chemistry between pyrite and isomeric xanthates (butyl xanthate and isobutyl xanthate was investigated by means of adsorption experiments, surface tension tests, and molecular dynamic simulations in this work. The flotation chemical results were confirmed and further interpreted by quantum chemical calculations. The experiment results demonstrated that the isobutyl xanthate exhibited superior adsorption capacity and surface activity than those of butyl xanthate in flotation chemistry. In addition, molecular dynamic simulations were simultaneously performed in constant number, constant volume and temperature (NVT, and constant number, constant volume, and pressure (NPT ensemble, indicating that the NPT ensemble was more suitable to the flotation system and the isobutyl xanthate was easier to be adsorbed on pyrite surface compared with butyl xanthate during an appropriate range of concentrations. Furthermore, the quantum chemical calculations elucidated that the isobutyl xanthate presented higher reactivity than that of the corresponding butyl xanthate based on the frontier molecular orbital theory of chemical reactivity, which was consistent with experimental and simulation results obtained. This work can provide theoretical guidance for an in-depth study of the flotation chemistry of pyrite with isomeric xanthates.

Evaluation of plasma chemistry and haematological studies on chickens infected with Eimeria tenella and E acervulina.

Science.gov (United States)

Fukata, T; Komba, Y; Sasai, K; Baba, E; Arakawa, A

1997-07-12

Plasma chemistry and haematological studies were conducted on chickens with coccidiosis. Male White Leghorn chickens, of two weeks old, were inoculated with 5 x 10(4) Eimeria tenella sporulated oocysts or with 1 x 10(6) E acervulina sporulated oocysts. Blood samples were taken four, seven and 11 days after inoculation. A wet chemistry system was applied to measure the plasma activities of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, gamma glutamyltransferase, creatine kinase, amylase and lactate dehydrogenase and the concentrations of creatine, total bilirubin, urate, total cholesterol, total protein, albumin, glucose and triglycerides. A dry chemistry system was applied to measure sodium, potassium, chloride and calcium. The number of red blood cells and packed cell volume were determined by a micro cell counter and blood pH was measured with a blood gas analyser. The erythrocyte count, packed cell volume, sodium and chloride levels in the chickens infected with E tenella were significantly (P < 0.05) lower than those of the uninfected controls. The significant decrease in blood pH of the chickens infected with E acervulina suggests malabsorption associated with duodenal lesions induced by the infection.

Avalanches and plastic flow in crystal plasticity: an overview

Science.gov (United States)

Papanikolaou, Stefanos; Cui, Yinan; Ghoniem, Nasr

2018-01-01

Crystal plasticity is mediated through dislocations, which form knotted configurations in a complex energy landscape. Once they disentangle and move, they may also be impeded by permanent obstacles with finite energy barriers or frustrating long-range interactions. The outcome of such complexity is the emergence of dislocation avalanches as the basic mechanism of plastic flow in solids at the nanoscale. While the deformation behavior of bulk materials appears smooth, a predictive model should clearly be based upon the character of these dislocation avalanches and their associated strain bursts. We provide here a comprehensive overview of experimental observations, theoretical models and computational approaches that have been developed to unravel the multiple aspects of dislocation avalanche physics and the phenomena leading to strain bursts in crystal plasticity.

Mechanical properties of concrete reinforced with recycled HDPE plastic fibres\\ud

OpenAIRE

Pešić, Ninoslav; Živanović, Stana; Garcia, Reyes; Papastergiou, Panos

2016-01-01

This work investigates potential engineering benefits of the pioneering application of simply extruded recycled high-density polyethylene (HDPE) plastic fibres in structural concrete. Mechanical and serviceability properties of concrete are studied through the testing of seven series of specimens: one made of the plain concrete and, for each of the two fibre diameters View the MathML source and View the MathML source, three series with 0.40%, 0.75% and 1.25% volume fraction of fibres. While t...

25th anniversary article: progress in chemistry and applications of functional indigos for organic electronics.

Science.gov (United States)

Głowacki, Eric Daniel; Voss, Gundula; Sariciftci, Niyazi Serdar

2013-12-17

Indigo and its derivatives are dyes and pigments with a long and distinguished history in organic chemistry. Recently, applications of this 'old' structure as a functional organic building block for organic electronics applications have renewed interest in these molecules and their remarkable chemical and physical properties. Natural-origin indigos have been processed in fully bio-compatible field effect transistors, operating with ambipolar mobilities up to 0.5 cm(2) /Vs and air-stability. The synthetic derivative isoindigo has emerged as one of the most successful building-blocks for semiconducting polymers for plastic solar cells with efficiencies > 5%. Another isomer of indigo, epindolidione, has also been shown to be one of the best reported organic transistor materials in terms of mobility (∼2 cm(2) /Vs) and stability. This progress report aims to review very recent applications of indigoids in organic electronics, but especially to logically bridge together the hereto independent research directions on indigo, isoindigo, and other materials inspired by historical dye chemistry: a field which was the root of the development of modern chemistry in the first place. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Melting the Plastic Ceiling: Overcoming Obstacles to Foster Leadership in Women Plastic Surgeons.

Science.gov (United States)

Silva, Amanda K; Preminger, Aviva; Slezak, Sheri; Phillips, Linda G; Johnson, Debra J

2016-09-01

The underrepresentation of women leaders in plastic surgery echoes a phenomenon throughout society. The importance of female leadership is presented, and barriers to gender equality in plastic surgery, both intrinsic and extrinsic, are discussed. Strategies for fostering women in leadership on an individual level and for the specialty of plastic surgery are presented.

Radiation damage studies on the optical and mechanical properties of plastic scintillators

International Nuclear Information System (INIS)

Mizue Hamada, Margarida; Roberto Rela, Paulo; Eduardo da Costa, Fabio; Henrique de Mesquita, Carlos

1999-01-01

This paper describes the radiation damage studies on a large volume plastic scintillator based in polystyrene doped with PPO and POPOP. The consequences on their mechanical and scintillation properties were evaluated before and after irradiation with different dose rates of 60 Co gamma radiation, in several doses. The optical results show a significant difference in the radiation susceptibility, when the plastic scintillator is irradiated at low rate (0.1 kGy/h) with that irradiated at high dose rate (85 kGy/h). The losses in the optical and mechanical properties increase as the irradiation dose is increased. The damage evaluated by the transmittance, emission intensity, pulse height and tensile strength was normalized as a damage fraction and fitted by a bi-exponential function. It was observed that the damage for irradiation is not permanent and it obeys a bi-exponential function

Some Limitations in the Use of Plastic and Dyed Plastic Dosimeters

DEFF Research Database (Denmark)

Miller, Arne; Bjergbakke, Erling; McLaughlin, W. L.

1975-01-01

Several practical plastic and dyed plastic dosimeters were examined under irradiation conditions similar to those used for radiation processing of materials. Cellulose triacetate, polymethyl methacrylate, polyvinyl chloride, dyed polymethyl methacrylate, dyed Cellophane and dyed Nylon were given...

HMSRP Hawaiian Monk Seal Blood Values (Establishing hematology and serum chemistry reference ranges for wild Hawaiian Monk Seals)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Hematology and serum chemistry evaluations are essential to a patients comprehensive health exam by providing measures of organ function, blood cell volume and...

An experimental study on thermo-catalytic pyrolysis of plastic waste using a continuous pyrolyser.

Science.gov (United States)

Auxilio, Anthony R; Choo, Wei-Lit; Kohli, Isha; Chakravartula Srivatsa, Srikanth; Bhattacharya, Sankar

2017-09-01

A bench scale, two-stage, thermo-catalytic reactor equipped with a continuous feeding system was used to pyrolyse pure and waste plastics. Experiments using five zeolitic and clay-based catalysts of different forms (pellet and powders) and different plastic feedstocks - virgin HDPE, HDPE w1aste and mixed plastic waste (MPW) were compared to the control experiments - pyrolysis without catalyst. Results indicated that the two pelletized catalysts were the most promising for the conditions employed. Of these two, one with higher acidity and surface area was highly selective for the gasoline fraction (C 5 -C 11 ) giving 80% from the total medium distillate conversion using virgin HDPE as feedstock. It also produced the least amount of olefins (17% for virgin HDPE, 4% for HDPE waste and 2% for MPW) and coke (HDPE, 3% for HDPE waste and 5% for MPW), and the highest aromatics content (22% for virgin HDPE from un-distilled medium distillate, 5% for HDPE and 13% for MPW both from distilled medium distillate). The second pelletized catalyst exhibited high selectivity for the diesel fraction (C 12 -C 25 ) giving 63% from the total medium distillate conversion using virgin HDPE as feedstock. The amount of coke deposited on the catalyst surface depended mainly on the mesopore volume, with less coke deposited as the mesopore volume increased. The variation in catalyst selectivity with acidity strength due to Lewis sites on the catalyst surface controls selectivity towards carbon chain length. Copyright © 2017 Elsevier Ltd. All rights reserved.

Exploration of fluorine chemistry at the multidisciplinary interface of chemistry and biology.

Science.gov (United States)

Ojima, Iwao

2013-07-05

Over the last three decades, my engagement in "fluorine chemistry" has evolved substantially because of the multidisciplinary nature of the research programs. I began my research career as a synthetic chemist in organometallic chemistry and homogeneous catalysis directed toward organic synthesis. Then, I was brought into a very unique world of "fluorine chemistry" in the end of 1970s. I started exploring the interface of fluorine chemistry and transition metal homogeneous catalysis first, which was followed by amino acids, peptides, and peptidomimetics for medicinal chemistry. Since then, I have been exploring the interfaces of fluorine chemistry and multidisciplinary fields of research involving medicinal chemistry, chemical biology, cancer biology, and molecular imaging. This perspective intends to cover my fruitful endeavor in the exploration of fluorine chemistry at the multidisciplinary interface of chemistry and biology in a chronological order to show the evolution of my research interest and strategy.

Nuclear chemistry

International Nuclear Information System (INIS)

Vertes, A.; Kiss, I.

1987-01-01

This book is an introduction to the application of nuclear science in modern chemistry. The first group of chapters discuss the basic phenomena and concepts of nuclear physics with emphasis on their relation to chemical problems, including the main properties and the composition of atomic nuclei, nuclear reactions, radioactive decay and interactions of radiation with matter. These chapters provide the basis for understanding the following chapters which encompass the wide scope of nuclear chemistry. The methods of the investigation of chemical structure based on the interaction of nuclear radiation with matter including positronium chemistry and other exotic atoms is elaborated in particular detail. Separate chapters are devoted to the use of radioactive tracers, the chemical consequences of nuclear processes (i.e. hot atom chemistry), radiation chemistry, isotope effects and their applications, and the operation of nuclear reactors

Nuclear chemistry

International Nuclear Information System (INIS)

Vertes, A.; Kiss, I.

1987-01-01

This book is an introduction to the application of nuclear science in modern chemistry. The first group of chapters discuss the basic phenomena and concepts of nuclear physics with emphasis on their relation to chemical problems, including the main properties and the composition of atomic nuclei, nuclear reactions, radioactive decay and interactions of radiation with matter. These chapters provide the basis for understanding the following chapters which encompass the wide scope of nuclear chemistry. The methods of the investigation of chemical structure based on the interaction of nuclear radiation with matter including positronium chemistry and other exotic atoms is elaborated in particular detail. Separate chapters are devoted to the use of radioactive tracers, the chemical consequences of nuclear processes (i.e. hot atom chemistry), radiation chemistry, isotope effects and their applications, and the operation of nuclear reactors. (Auth.)

Quantum chemistry literature data base

International Nuclear Information System (INIS)

Ohno, Kimio; Morokuma, Keiji

1982-01-01

Ab initio computations of atomic and molecular electronic structure now appear in so many journals that it is very difficult for interested scientistics to locate proper and comprehensive references. This book is designed to help them and contains more than 2500 references to the literature published in the years 1978-1980. These have been gathered from nineteen well-known international core journals by quantum chemists themselves and the result is a thorough bibliography. Each entry is a full reference consisting of the following items: (1) authors, (2) journal name, volume, page and year, (3) compounds, (4) methods of calculation, (5) basis sets, (6) calculated properties, and (7) comments. For easy access to the references, the reader can consult the compound and author indexes. A short article on the reliability of ab initio calculations is included as an appendix; this gives a rough idea about the accuracy of the calculated results reported. As the book has been complied using the resources of a computer data base of quantum chemistry literature, it is particularly up to date and the authors will be able to provide supplements regularly. This bibliography will be an asset to large departments of chemistry and all university libraries. (orig.)

Plastic Fishes

CERN Multimedia

Trettnak, Wolfgang

2015-01-01

In terms of weight, the plastic pollution in the world’s oceans is estimated to be around 300,000 tonnes. This plastic comes from both land-based and ocean-based sources. A lecture at CERN by chemist Wolfgang Trettnak addressed this issue and highlighted the role of art in raising people’s awareness. The slideshow below gives you a taste of the artworks by Wolfgang Trettnak and Margarita Cimadevila.

From Modeling of Plasticity in Single-Crystal Superalloys to High-Resolution X-rays Three-Crystal Diffractometer Peaks Simulation

Science.gov (United States)

Jacques, Alain

2016-12-01

The dislocation-based modeling of the high-temperature creep of two-phased single-crystal superalloys requires input data beyond strain vs time curves. This may be obtained by use of in situ experiments combining high-temperature creep tests with high-resolution synchrotron three-crystal diffractometry. Such tests give access to changes in phase volume fractions and to the average components of the stress tensor in each phase as well as the plastic strain of each phase. Further progress may be obtained by a new method making intensive use of the Fast Fourier Transform, and first modeling the behavior of a representative volume of material (stress fields, plastic strain, dislocation densities…), then simulating directly the corresponding diffraction peaks, taking into account the displacement field within the material, chemical variations, and beam coherence. Initial tests indicate that the simulated peak shapes are close to the experimental ones and are quite sensitive to the details of the microstructure and to dislocation densities at interfaces and within the soft γ phase.

Plasticity resembling spike-timing dependent synaptic plasticity: the evidence in human cortex

Directory of Open Access Journals (Sweden)

Florian Müller-Dahlhaus

2010-07-01

Full Text Available Spike-timing dependent plasticity (STDP has been studied extensively in a variety of animal models during the past decade but whether it can be studied at the systems level of the human cortex has been a matter of debate. Only recently newly developed non-invasive brain stimulation techniques such as transcranial magnetic stimulation (TMS have made it possible to induce and assess timing dependent plasticity in conscious human subjects. This review will present a critical synopsis of these experiments, which suggest that several of the principal characteristics and molecular mechanisms of TMS-induced plasticity correspond to those of STDP as studied at a cellular level. TMS combined with a second phasic stimulation modality can induce bidirectional long-lasting changes in the excitability of the stimulated cortex, whose polarity depends on the order of the associated stimulus-evoked events within a critical time window of tens of milliseconds. Pharmacological evidence suggests an NMDA receptor mediated form of synaptic plasticity. Studies in human motor cortex demonstrated that motor learning significantly modulates TMS-induced timing dependent plasticity, and, conversely, may be modulated bidirectionally by prior TMS-induced plasticity, providing circumstantial evidence that long-term potentiation-like mechanisms may be involved in motor learning. In summary, convergent evidence is being accumulated for the contention that it is now possible to induce STDP-like changes in the intact human central nervous system by means of TMS to study and interfere with synaptic plasticity in neural circuits in the context of behaviour such as learning and memory.

Analytical Chemistry as Methodology in Modern Pure and Applied Chemistry

OpenAIRE

Honjo, Takaharu

2001-01-01

Analytical chemistry is an indispensable methodology in pure and applied chemistry, which is often compared to a foundation stone of architecture. In the home page of jsac, it is said that analytical chemistry is a learning of basic science, which treats the development of method in order to get usefull chemical information of materials by means of detection, separation, and characterization. Analytical chemistry has recently developed into analytical sciences, which treats not only analysis ...

Chain Gang-The Chemistry of Polymers (edited by Mickey Sarquis)

Science.gov (United States)

Collard, David M.

1999-01-01

Science in Our World, Vol. 5. Mickey Sarquis, series editor. Terrific Science Press: Middletown, OH, 1995. xiv + 149 pp. ISBN 1-883822-13-0. Spiral-bound, $13.95. Our familiarity with plastics makes polymers ideal examples of chemicals for discussion in K-12 science classes. Most importantly, polymers can be used as examples of chemicals that are safe to handle and of obvious use to society. The structures of polymers are easily represented by a number of models. These simple models go a long way in explaining the familiar physical properties of plastics. However, the introduction of polymers in the classroom relies on the availability of teaching material, experiments, and demonstrations that illustrate concepts in the current science curriculum. Chain Gang-The Chemistry of Polymers, one of the Science in Our World series published by the Center for Chemical Education at Miami University-Middletown (Ohio), will serve as a great resource for teachers interested in providing their students with a series of activities that can be related to their everyday experiences with these ubiquitous chemicals. After a brief introduction to some basic concepts, the book presents a series of 23 experiments. The collection of experiments presented here spans illustrations of chemistry, physical properties, analysis, and processing. Each experiment is recommended as either a hands-on activity or demonstration for various grade levels. A guide for the teacher suggests how the experiment can be used to illustrate topics in the science curriculum. The materials required for each activity are listed in detail, with quantities and sources (all materials are available from Flinn Scientific or hardware stores). There are detailed instructions for preparation of each experiment and how to introduce the experiment to students, and step-by-step instructions for activity. Very importantly, safety and disposal issues are clearly presented. Suggestions for cross-curriculum integration are also

Fundamentals of nuclear chemistry

International Nuclear Information System (INIS)

Majer, K.

1982-01-01

The textbook is a Czech-to-German translation of the second revised edition and covers the subject under the headings: general nuclear chemistry, methods of nuclear chemistry, preparative nuclear chemistry, analytical nuclear chemistry, and applied chemistry. The book is especially directed to students

HMI Department of Radiation Chemistry: Results of scientific activities in 1984

International Nuclear Information System (INIS)

1985-01-01

In the radiation chemistry department of the Hahn-Meitner-Institute in Berlin, 4 subjects are treated largely the progress of which made in 1984 is herein reported: 1) Interface processes and energy conversion (reaction pathways of photoinduced charge carriers and their in energy conversion mechanisms); 2) Pulse radiolysis (generation and investigation of shortlived chemically quick-reacting particles); 3) Kinematics (reciprocal action with ion, atom and molecule collisions; clarification of the dynamics of chemical reactions; 4) Insulators and plastics/physical and chemical primary processes when these materials are subjected to high-energy radiation, light or UV light). A list of publications and lectures is added to complement the description of results gained from R and D work. (BR) [de

Surface chemistry essentials

CERN Document Server

Birdi, K S

2013-01-01

Surface chemistry plays an important role in everyday life, as the basis for many phenomena as well as technological applications. Common examples range from soap bubbles, foam, and raindrops to cosmetics, paint, adhesives, and pharmaceuticals. Additional areas that rely on surface chemistry include modern nanotechnology, medical diagnostics, and drug delivery. There is extensive literature on this subject, but most chemistry books only devote one or two chapters to it. Surface Chemistry Essentials fills a need for a reference that brings together the fundamental aspects of surface chemistry w

Hydraulic separation of plastic wastes: Analysis of liquid-solid interaction.

Science.gov (United States)

Moroni, Monica; Lupo, Emanuela; La Marca, Floriana

2017-08-01

The separation of plastic wastes in mechanical recycling plants is the process that ensures high-quality secondary raw materials. An innovative device employing a wet technology for particle separation is presented in this work. Due to the combination of the characteristic flow pattern developing within the apparatus and density, shape and size differences among two or more polymers, it allows their separation into two products, one collected within the instrument and the other one expelled through its outlet ducts. The kinematic investigation of the fluid flowing within the apparatus seeded with a passive tracer was conducted via image analysis for different hydraulic configurations. The two-dimensional turbulent kinetic energy results strictly connected to the apparatus separation efficacy. Image analysis was also employed to study the behaviour of mixtures of passive tracer and plastic particles with different physical characteristics in order to understand the coupling regime between fluid and solid phases. The two-dimensional turbulent kinetic energy analysis turned out to be fundamental to this aim. For the tested operating conditions, two-way coupling takes place, i.e., the fluid exerts an influence on the plastic particle and the opposite occurs too. Image analysis confirms the outcomes from the investigation of the two-phase flow via non-dimensional numbers (particle Reynolds number, Stokes number and solid phase volume fraction). Copyright © 2017 Elsevier Ltd. All rights reserved.

Plastic and Non-plastic Debris Ingestion in Three Gull Species Feeding in an Urban Landfill Environment.

Science.gov (United States)

Seif, S; Provencher, J F; Avery-Gomm, S; Daoust, P-Y; Mallory, M L; Smith, P A

2018-04-01

Plastic debris is recognized as a widespread, common and problematic environmental pollutant. An important consequence of this pollution is the ingestion of plastic debris by wildlife. Assessing the degree to which different species ingest plastics, and the potential effects of these plastics on their health are important research needs for understanding the impacts of plastic pollution. We examined debris (plastic and other types) ingestion in three sympatric overwintering gull species (Herring gulls Larus smithsonianus, Great Black-backed Gulls Larus marinus, and Iceland Gulls Larus glaucoides) to understand how debris ingestion differs among species, age classes and sexes in gulls. We also assessed how plastic burdens were associated with body condition to investigate how gulls may be affected by debris ingestion. There were no differences among the species, age classes or sexes in the incidence of debris ingestion (plastic or otherwise), the mass or number of debris pieces ingested. We found no correlation between ingested plastics burdens and individual condition. Gulls ingested plastic debris, but also showed high levels of other debris types as well, including metal, glass and building materials, including a metal piece of debris found within an abscess in the stomach. Thus, when the health effects of debris ingestion on gulls, and other species that ingest debris, is of interest, either from a physical or chemical perspective, it may be necessary to consider all debris types and not just plastic burdens as is often currently done for seabirds.

Partial Molar Volume of Methanol in Water: Effect of Polarizability

Czech Academy of Sciences Publication Activity Database

Moučka, F.; Nezbeda, Ivo

2009-01-01

Roč. 74, č. 4 (2009), s. 559-563 ISSN 0010-0765 R&D Projects: GA AV ČR IAA400720802 Institutional research plan: CEZ:AV0Z40720504 Keywords : water–methanol mixtures * partial molar volume * polarizability Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 0.856, year: 2009

Education on the Business of Plastic Surgery During Training: A Survey of Plastic Surgery Residents.

Science.gov (United States)

Ovadia, Steven A; Gishen, Kriya; Desai, Urmen; Garcia, Alejandro M; Thaller, Seth R

2018-06-01

Entrepreneurial skills are important for physicians, especially plastic surgeons. Nevertheless, these skills are not typically emphasized during residency training. Evaluate the extent of business training at plastic surgery residency programs as well as means of enhancing business training. A 6-question online survey was sent to plastic surgery program directors for distribution to plastic surgery residents. Responses from residents at the PGY2 level and above were included for analysis. Tables were prepared to present survey results. Hundred and sixty-six residents including 147 PGY2 and above residents responded to our survey. Only 43.5% reported inclusion of business training in their plastic surgery residency. A majority of residents reported they do not expect on graduation to be prepared for the business aspects of plastic surgery. Additionally, a majority of residents feel establishment of a formal lecture series on the business of plastic surgery would be beneficial. Results from our survey indicate limited training at plastic surgery programs in necessary business skills. Plastic surgery residency programs should consider incorporating or enhancing elements of business training in their curriculum. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

The effects of plastic waves on the numerical convergence of the viscous-plastic and elastic-viscous-plastic sea-ice models

Science.gov (United States)

Williams, James; Tremblay, L. Bruno; Lemieux, Jean-François

2017-07-01

The plastic wave speed is derived from the linearized 1-D version of the widely used viscous-plastic (VP) and elastic-viscous-plastic (EVP) sea-ice models. Courant-Friedrichs-Lewy (CFL) conditions are derived using the propagation speed of the wave. 1-D numerical experiments of the VP, EVP and EVP* models successfully recreate a reference solution when the CFL conditions are satisfied, in agreement with the theory presented. The IMplicit-EXplicit (IMEX) method is shown to effectively alleviate the plastic wave CFL constraint on the timestep in the implicitly solved VP model in both 1-D and 2-D. In 2-D, the EVP and EVP* models show first order error in the simulated velocity field when the plastic wave is not resolved. EVP simulations are performed with various advective timestep, number of subcycles, and elastic-wave damping timescales. It is found that increasing the number of subcycles beyond that needed to resolve the elastic wave does not improve the quality of the solution. It is found that reducing the elastic wave damping timescale reduces the spatial extent of first order errors cause by the unresolved plastic wave. Reducing the advective timestep so that the plastic wave is resolved also reduces the velocity error in terms of magnitude and spatial extent. However, the parameter set required for convergence to within the error bars of satellite (RGPS) deformation fields is impractical for use in climate model simulations. The behavior of the EVP* method is analogous to that of the EVP method except that it is not possible to reduce the damping timescale with α = β.

The New Color of Chemistry: Green Chemistry

Directory of Open Access Journals (Sweden)

Zuhal GERÇEK

2012-01-01

Full Text Available Green chemistry which is the new application of chemistry rules provides solutions to problems that mankind is faced with climate changes, sustainable agriculture, energy, toxics, depletion of natural sources e.g. designing new chemicals and processes that production and utilization of hazardous matters. So, it is the indispensible tool for sustainable development. Current and future chemists should consider the human health and ecological issues in their professional life. In order to provide a solution for this requirement, green chemistry rules and under standings should be primarily taken in the university curriculum and at all educational levels.

Coliquefaction of coal, tar sand bitumen and plastic (interaction among coal, bitumen and plastic); Sekitan/tar sand bitumen/plastic no kyoekika ni okeru kyozon busshitsu no eikyo

Energy Technology Data Exchange (ETDEWEB)

Yamaguchi, H.; Okuyama, Y.; Matsubara, K. [NKK Corp., Tokyo (Japan); Kamo, T.; Sato, Y. [National Institute for Resources and Environment, Tsukuba (Japan)

1996-10-28

For the improvement of economy, coliquefaction of coal, tar sand bitumen and plastic was performed under low hydrogen pressure, to investigate the influence of interaction among these on the liquefaction characteristics. For comparison, coliquefaction was also performed under the hydrogen pressure same as the NEDOL process. In addition, for clarifying its reaction mechanism, coliquefaction of dibenzyl and plastic was performed as a model experiment, to illustrate the distribution of products and composition of oil, and to discuss the interaction between dibenzyl and various plastics, and between various plastics. Under direct coal liquefaction conditions, coprocessing of Tanito Harum coal, Athabasca tar sand and plastic was carried out under low hydrogen pressure with an autoclave. The observed value of oil yield was higher than the calculated value based on the values from separate liquefaction of coal and plastic, which suggested the interaction between coal and the mixed plastic. The results of coliquefaction of coal, tar sand bitumen and plastic could be explained from the obtained oil yield and its composition by the coliquefaction of dibenzyl and plastic. 2 refs., 3 tabs.

Technetium chemistry

International Nuclear Information System (INIS)

Burns, C.; Bryan, J.; Cotton, F.; Ott, K.; Kubas, G.; Haefner, S.; Barrera, J.; Hall, K.; Burrell, A.

1996-01-01

Technetium chemistry is a young and developing field. Despite the limited knowledge of its chemistry, technetium is the workhorse for nuclear medicine. Technetium is also a significant environmental concern because it is formed as a byproduct of nuclear weapons production and fission-power generators. Development of new technetium radio-pharmaceuticals and effective environmental control depends strongly upon knowledge of basic technetium chemistry. The authors performed research into the basic coordination and organometallic chemistry of technetium and used this knowledge to address nuclear medicine and environmental applications. This is the final report of a three-year Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL)

Chemistry of Technetium

International Nuclear Information System (INIS)

Omori, Takashi

2001-01-01

Since the late 1970's the coordination chemistry of technetium has been developed remarkably. The background of the development is obviously related to the use of technetium radiopharmaceuticals for diagnosis in nuclear medicine. Much attention has also been denoted to the chemical behavior of environmental 99 Tc released from reprocessing plants. This review covers the several aspects of technetium chemistry, including production of radioisotopes, analytical chemistry and coordination chemistry. In the analytical chemistry, separation of technetium, emphasizing chromatography and solvent extraction, is described together with spectrophotometric determination of technetium. In the coordination chemistry of technetium, a characteristic feature of the chemistry of Tc(V) complexes is referred from the view point of the formation of a wide variety of highly stable complexes containing the Tc=O or Tc≡N bond. Kinetic studies of the preparation of Tc(III) complexes using hexakis (thiourea) technetium(III) ion as a starting material are summarized, together with the base hydrolysis reactions of Tc(III), Tc(IV) and Tc(V) complexes. (author)

A review of plastic waste biodegradation.

Science.gov (United States)

Zheng, Ying; Yanful, Ernest K; Bassi, Amarjeet S

2005-01-01

With more and more plastics being employed in human lives and increasing pressure being placed on capacities available for plastic waste disposal, the need for biodegradable plastics and biodegradation of plastic wastes has assumed increasing importance in the last few years. This review looks at the technological advancement made in the development of more easily biodegradable plastics and the biodegradation of conventional plastics by microorganisms. Additives, such as pro-oxidants and starch, are applied in synthetic materials to modify and make plastics biodegradable. Recent research has shown that thermoplastics derived from polyolefins, traditionally considered resistant to biodegradation in ambient environment, are biodegraded following photo-degradation and chemical degradation. Thermoset plastics, such as aliphatic polyester and polyester polyurethane, are easily attacked by microorganisms directly because of the potential hydrolytic cleavage of ester or urethane bonds in their structures. Some microorganisms have been isolated to utilize polyurethane as a sole source of carbon and nitrogen source. Aliphatic-aromatic copolyesters have active commercial applications because of their good mechanical properties and biodegradability. Reviewing published and ongoing studies on plastic biodegradation, this paper attempts to make conclusions on potentially viable methods to reduce impacts of plastic waste on the environment.

Plasticizer Effect on Rheological Behaviour of Screen Printing Pastes Based on Barium Titanate Nanopowder

International Nuclear Information System (INIS)

Dulina, I; Umerova, S; Ragulya, A

2015-01-01

The dependence of rheological behaviour of pastes based on BaTiO 3 nanopowder vs. plasticizer content has been investigated. All pastes prepared for research can be divided into groups by structure types and viscosity. Such a grouping has been explained by different interaction between nanoparticles and binder in the pastes. Particles with molecules of binder form clusters – the representative units in the volume of paste where particles are uniformly distributed. Plasticizer adding effects on binder molecule conformation and change clusters size. Bond strength between clusters can be specified with rheopexy in the area of low shear stress and low strain rates. Rheopexy degree increasing authenticates interaction intensification between clusters. Rheopexy structure destruction leads to separate clusters formation and initiation of the pseudoplastic flow stage. The end of pseudoplastic flow corresponds to structure with clusters assembled into separated layers. Further shear stress increasing leads to inter-clusters bonds appear which can be deformed elastically and the temporary local linkage is possible. Such a phenomenon fully discloses the features of thixotropic structure destruction in plasticized pastes. (paper)

Recycling of plastics

Energy Technology Data Exchange (ETDEWEB)

Kaminsky, W; Menzel, J; Sinn, H

1976-01-01

Considering the shortage of raw materials and environmental pollution, the recycling of plastic waste is a very important topic. Pilot plants for research in Funabashi Japan, Franklin (Ohio) U.S.A., and the R 80-process of Krauss Maffei, W. Germany, have demonstrated the possibility of reclaiming plastics from refuse. Old tires and waste from the plastic producing and manufacturing industries are readily available. The pyrolysis of plastic yields gaseous and liquid products, and the exploitation of this cracking reaction has been demonstrated by pilot plants in Japan and Great Britain. Further laboratory scale experiments are taking place in W. Germany. In continuous fluidized beds and in molten salts, polyethylene, polypropylene, polyvinylchloride, polystyrene and rubber are pyrolysed and better than 98 percent conversion is obtained. Up to 40 percent of the feed can be obtained as aromatic compounds, and a pilot plant is under construction. As a first step PVC-containing material can be almost quantitatively dehydrochlorinated.

Plastics and environment

International Nuclear Information System (INIS)

Avenas, P.

1996-01-01

Synthetic organic polymers, such as plastics, PVC, polyamides etc are considered less ecological than natural materials such as wood. Other artificial materials such as metals, glass or biodegradable plastics have also a better image than petroleum products. This short paper demonstrates that the manufacturing or the transport of every material uses energy and that the complete energy balance sheet of a plastic bottle, for instance, is more favourable than the one of a glass bottle. Plastic materials are also easily valorized and recycled and part of the energy spent during manufacturing can be recovered during incineration for district heating. During the life-cycle of such a synthetic material, the same petroleum quantity can be used twice which leads to less negative effects on the environment. Finally, the paper focusses on the problem of biodegradable materials which are not degradable when buried under several meters of wastes and which are a nuisance to recycling. (J.S.)

Stem cell plasticity.

Science.gov (United States)

Lakshmipathy, Uma; Verfaillie, Catherine

2005-01-01

The central dogma in stem cell biology has been that cells isolated from a particular tissue can renew and differentiate into lineages of the tissue it resides in. Several studies have challenged this idea by demonstrating that tissue specific cell have considerable plasticity and can cross-lineage restriction boundary and give rise to cell types of other lineages. However, the lack of a clear definition for plasticity has led to confusion with several reports failing to demonstrate that a single cell can indeed differentiate into multiple lineages at significant levels. Further, differences between results obtained in different labs has cast doubt on some results and several studies still await independent confirmation. In this review, we critically evaluate studies that report stem cell plasticity using three rigid criteria to define stem cell plasticity; differentiation of a single cell into multiple cell lineages, functionality of differentiated cells in vitro and in vivo, robust and persistent engraft of transplanted cells.

OSA Trends in Optics and Photonics Series, Volume 14 Spatial Light Modulators

Science.gov (United States)

1998-05-26

controlled optical diffraction by volume holograms in electrooptic crystals," Sov. Tech. Phys. Lett. v. 3, pp. 36-38, 1977. 9. A. J. Agranat and M. Silberg ...the BCB layer using CF4 + 02 (average etch rate 0.21 fim per minute) or SF6 + 02 gas chemistries (0.25 [im per minute). For a 2 /im patterned via...5,000 angstroms of pure aluminum is then deposited as the upper mirror layer. The aluminum is dry etched in a chlorine-based gas chemistry . The

First all-union symposium on shock pressures, October 24-26, 1973, Moscow. Volume 2

International Nuclear Information System (INIS)

Batsanov, S.S.

Twenty-two papers on the chemistry of impulsive pressures are contained in this volume. The papers deal primarily with shock wave propagation in various materials (particularly oxides) and explosive forming and sintering

AN APPLICATION OF THE LOGISTIC REGRESSION MODEL IN THE EXPERIMENTAL PHYSICAL CHEMISTRY

Directory of Open Access Journals (Sweden)

Elpidio Corral-López

2015-06-01

Full Text Available The calculation of intensive properties molar volumes of ethanol-water mixtures by experimental densities and tangent method in the Physical Chemistry Laboratory presents the problem of making manually the molar volume curve versus mole fraction and the trace of the tangent line trace. The advantage of using a statistical model the Logistic Regression on a Texas VOYAGE graphing calculator allowed trace the curve and the tangents in situ, and also evaluate the students work during the experimental session. The error percentage between the molar volumes calculated using literature data and those obtained with statistical method is minimal, which validates the model. It is advantageous use the calculator with this application as a teaching support tool, reducing the evaluation time of 3 weeks to 3 hours.

Cross-Linked Amylose Bio-Plastic: A Transgenic-Based Compostable Plastic Alternative

Directory of Open Access Journals (Sweden)

Domenico Sagnelli

2017-09-01

Full Text Available Bio-plastics and bio-materials are composed of natural or biomass derived polymers, offering solutions to solve immediate environmental issues. Polysaccharide-based bio-plastics represent important alternatives to conventional plastic because of their intrinsic biodegradable nature. Amylose-only (AO, an engineered barley starch with 99% amylose, was tested to produce cross-linked all-natural bioplastic using normal barley starch as a control. Glycerol was used as plasticizer and citrate cross-linking was used to improve the mechanical properties of cross-linked AO starch extrudates. Extrusion converted the control starch from A-type to Vh- and B-type crystals, showing a complete melting of the starch crystals in the raw starch granules. The cross-linked AO and control starch specimens displayed an additional wide-angle diffraction reflection. Phospholipids complexed with Vh-type single helices constituted an integrated part of the AO starch specimens. Gas permeability tests of selected starch-based prototypes demonstrated properties comparable to that of commercial Mater-Bi© plastic. The cross-linked AO prototypes had composting characteristics not different from the control, indicating that the modified starch behaves the same as normal starch. The data shows the feasibility of producing all-natural bioplastic using designer starch as raw material.

Cross-Linked Amylose Bio-Plastic: A Transgenic-Based Compostable Plastic Alternative

Science.gov (United States)

Sagnelli, Domenico; Kemmer, Gerdi Christine; Holse, Mette; Hebelstrup, Kim H.; Bao, Jinsong; Stelte, Wolfgang; Bjerre, Anne-Belinda; Blennow, Andreas

2017-01-01

Bio-plastics and bio-materials are composed of natural or biomass derived polymers, offering solutions to solve immediate environmental issues. Polysaccharide-based bio-plastics represent important alternatives to conventional plastic because of their intrinsic biodegradable nature. Amylose-only (AO), an engineered barley starch with 99% amylose, was tested to produce cross-linked all-natural bioplastic using normal barley starch as a control. Glycerol was used as plasticizer and citrate cross-linking was used to improve the mechanical properties of cross-linked AO starch extrudates. Extrusion converted the control starch from A-type to Vh- and B-type crystals, showing a complete melting of the starch crystals in the raw starch granules. The cross-linked AO and control starch specimens displayed an additional wide-angle diffraction reflection. Phospholipids complexed with Vh-type single helices constituted an integrated part of the AO starch specimens. Gas permeability tests of selected starch-based prototypes demonstrated properties comparable to that of commercial Mater-Bi© plastic. The cross-linked AO prototypes had composting characteristics not different from the control, indicating that the modified starch behaves the same as normal starch. The data shows the feasibility of producing all-natural bioplastic using designer starch as raw material. PMID:28973963

Cross-Linked Amylose Bio-Plastic: A Transgenic-Based Compostable Plastic Alternative.

Science.gov (United States)

Sagnelli, Domenico; Hooshmand, Kourosh; Kemmer, Gerdi Christine; Kirkensgaard, Jacob J K; Mortensen, Kell; Giosafatto, Concetta Valeria L; Holse, Mette; Hebelstrup, Kim H; Bao, Jinsong; Stelte, Wolfgang; Bjerre, Anne-Belinda; Blennow, Andreas

2017-09-30

Bio-plastics and bio-materials are composed of natural or biomass derived polymers, offering solutions to solve immediate environmental issues. Polysaccharide-based bio-plastics represent important alternatives to conventional plastic because of their intrinsic biodegradable nature. Amylose-only (AO), an engineered barley starch with 99% amylose, was tested to produce cross-linked all-natural bioplastic using normal barley starch as a control. Glycerol was used as plasticizer and citrate cross-linking was used to improve the mechanical properties of cross-linked AO starch extrudates. Extrusion converted the control starch from A-type to Vh- and B-type crystals, showing a complete melting of the starch crystals in the raw starch granules. The cross-linked AO and control starch specimens displayed an additional wide-angle diffraction reflection. Phospholipids complexed with Vh-type single helices constituted an integrated part of the AO starch specimens. Gas permeability tests of selected starch-based prototypes demonstrated properties comparable to that of commercial Mater-Bi © plastic. The cross-linked AO prototypes had composting characteristics not different from the control, indicating that the modified starch behaves the same as normal starch. The data shows the feasibility of producing all-natural bioplastic using designer starch as raw material.

The crystallography of carbide-free bainites in thermo-mechanically processed low Si transformation-induced plasticity steels

Energy Technology Data Exchange (ETDEWEB)

Pereloma, Elena V. [School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong, New South Wales 2522 (Australia); Electron Microscopy Centre, University of Wollongong, New South Wales 2500 (Australia); Al-Harbi, Fayez [School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong, New South Wales 2522 (Australia); Gazder, Azdiar A., E-mail: azdiar@uow.edu.au [Electron Microscopy Centre, University of Wollongong, New South Wales 2500 (Australia)

2014-12-05

Highlights: • First EBSD study comparing ferrite in granular bainite and bainitic laths in two TRIP steels. • Both TRIP steels (base and with Nb–Ti additions) subjected to the same TMP schedule. • Crystallography of the ferrite in the 2 bainites studied using the K–S orientation relationship. • Variants in GB associated with self-accommodation. • BF variant selection linked to RA plastic accommodation and limited volume. - Abstract: Carbide-free bainites are important microstructural constituents in bainitic, nanobainitic and transformation-induced plasticity (TRIP) steels. A comparison of the crystallography of ferrite in granular bainite and bainitic ferrite lath morphologies, both of which were simultaneously present in a base and a Nb–Ti containing TRIP steel, has been carried out using electron back-scattering diffraction. Ferrite in granular bainite was characterised by the realisation of nearly all 24 variants of the Kurdjumov–Sachs orientation relationship; which in turn was associated with the self-accommodation of the transformation strain. On the other hand, bainitic ferrite comprised a mostly parallel lath structure between thick interlayers of retained austenite and exhibited variant selection such that one or more crystallographic packets are not realised and sometimes only 1–2 variants formed in a crystallographic packet. The variant selection in bainitic ferrite laths was associated with: (i) the plastic accommodation of transformation strain by retained austenite and, (ii) the limited available volume for its formation.

The crystallography of carbide-free bainites in thermo-mechanically processed low Si transformation-induced plasticity steels

International Nuclear Information System (INIS)

Pereloma, Elena V.; Al-Harbi, Fayez; Gazder, Azdiar A.

2014-01-01

Highlights: • First EBSD study comparing ferrite in granular bainite and bainitic laths in two TRIP steels. • Both TRIP steels (base and with Nb–Ti additions) subjected to the same TMP schedule. • Crystallography of the ferrite in the 2 bainites studied using the K–S orientation relationship. • Variants in GB associated with self-accommodation. • BF variant selection linked to RA plastic accommodation and limited volume. - Abstract: Carbide-free bainites are important microstructural constituents in bainitic, nanobainitic and transformation-induced plasticity (TRIP) steels. A comparison of the crystallography of ferrite in granular bainite and bainitic ferrite lath morphologies, both of which were simultaneously present in a base and a Nb–Ti containing TRIP steel, has been carried out using electron back-scattering diffraction. Ferrite in granular bainite was characterised by the realisation of nearly all 24 variants of the Kurdjumov–Sachs orientation relationship; which in turn was associated with the self-accommodation of the transformation strain. On the other hand, bainitic ferrite comprised a mostly parallel lath structure between thick interlayers of retained austenite and exhibited variant selection such that one or more crystallographic packets are not realised and sometimes only 1–2 variants formed in a crystallographic packet. The variant selection in bainitic ferrite laths was associated with: (i) the plastic accommodation of transformation strain by retained austenite and, (ii) the limited available volume for its formation

Physical Chemistry '98: Fourth International Conference on Fundamental and Applied Aspects of Physical Chemistry - Papers

International Nuclear Information System (INIS)

Ribnikar, S.; Anic, S.

1998-01-01

The proceedings has following chapters: Plenary lectures; Chemical Thermodynamics; Spectroscopy, Molecular Structures, Physical Chemistry of Plasma; Kinetics, Catalysis, Nonlinear Dynamics; Electrochemistry; Biophysical Chemistry, Photochemistry, Radiation Chemistry; Radiochemistry, Nuclear Chemistry; Solid State Physical Chemistry, Material Science; Macromolecular Physical Chemistry; Environmental Protection; Phase Boundaries; Complex Compounds; General Physical Chemistry. A separated abstract was prepared for each of the 20 papers selected from the three chapters: Biophysical Chemistry, Photochemistry, Radiation Chemistry; Radiochemistry, Nuclear Chemistry. and Environmental Protection. Refs and figs

Polymer-Derived Boron Nitride: A Review on the Chemistry, Shaping and Ceramic Conversion of Borazine Derivatives.