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Sample records for identify minimum polymer

  1. High-density polymer microarrays: identifying synthetic polymers that control human embryonic stem cell growth.

    Science.gov (United States)

    Hansen, Anne; Mjoseng, Heidi K; Zhang, Rong; Kalloudis, Michail; Koutsos, Vasileios; de Sousa, Paul A; Bradley, Mark

    2014-06-01

    The fabrication of high-density polymer microarray is described, allowing the simultaneous and efficient evaluation of more than 7000 different polymers in a single-cellular-based screen. These high-density polymer arrays are applied in the search for synthetic substrates for hESCs culture. Up-scaling of the identified hit polymers enables long-term cellular cultivation and promoted successful stem-cell maintenance. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Medium Effects on Minimum Inhibitory Concentrations of Nylon-3 Polymers against E. coli

    Science.gov (United States)

    Choi, Heejun; Chakraborty, Saswata; Liu, Runhui; Gellman, Samuel H.; Weisshaar, James C.

    2014-01-01

    Minimum inhibitory concentrations (MICs) against E. coli were measured for three nylon-3 polymers using Luria-Bertani broth (LB), brain-heart infusion broth (BHI), and a chemically defined complete medium (EZRDM). The polymers differ in the ratio of hydrophobic to cationic subunits. The cationic homopolymer is inert against E. coli in BHI and LB, but becomes highly potent in EZRDM. A mixed hydrophobic/cationic polymer with a hydrophobic t-butylbenzoyl group at its N-terminus is effective in BHI, but becomes more effective in EZRDM. Supplementation of EZRDM with the tryptic digest of casein (often found in LB) recapitulates the LB and BHI behavior. Additional evidence suggests that polyanionic peptides present in LB and BHI may form electrostatic complexes with cationic polymers, decreasing activity by diminishing binding to the anionic lipopolysaccharide layer of E. coli. In contrast, two natural antimicrobial peptides show no medium effects. Thus, the use of a chemically defined medium helps to reveal factors that influence antimicrobial potency of cationic polymers and functional differences between these polymers and evolved antimicrobial peptides. PMID:25153714

  3. Minimum free-energy paths for the self-organization of polymer brushes.

    Science.gov (United States)

    Gleria, Ignacio; Mocskos, Esteban; Tagliazucchi, Mario

    2017-03-22

    A methodology to calculate minimum free-energy paths based on the combination of a molecular theory and the improved string method is introduced and applied to study the self-organization of polymer brushes under poor solvent conditions. Polymer brushes in a poor solvent cannot undergo macroscopic phase separation due to the physical constraint imposed by the grafting points; therefore, they microphase separate forming aggregates. Under some conditions, the theory predicts that the homogeneous brush and the aggregates can exist as two different minima of the free energy. The theoretical methodology introduced in this work allows us to predict the minimum free-energy path connecting these two minima as well as the morphology of the system along the path. It is shown that the transition between the homogeneous brush and the aggregates may involve a free-energy barrier or be barrierless depending on the relative stability of the two morphologies and the chain length and grafting density of the polymer. In the case where a free-energy barrier exists, one of the morphologies is a metastable structure and, therefore, the properties of the brush as the quality of the solvent is cycled are expected to display hysteresis. The theory is also applied to study the adhesion/deadhesion transition between two opposing surfaces modified by identical polymer brushes and it is shown that this process may also require surpassing a free-energy barrier.

  4. Simple Organics and Biomonomers Identified in HCN Polymers: An Overview

    Directory of Open Access Journals (Sweden)

    Susana Osuna-Esteban

    2013-07-01

    Full Text Available Hydrogen cyanide (HCN is a ubiquitous molecule in the Universe. It is a compound that is easily produced in significant yields in prebiotic simulation experiments using a reducing atmosphere. HCN can spontaneously polymerise under a wide set of experimental conditions. It has even been proposed that HCN polymers could be present in objects such as asteroids, moons, planets and, in particular, comets. Moreover, it has been suggested that these polymers could play an important role in the origin of life. In this review, the simple organics and biomonomers that have been detected in HCN polymers, the analytical techniques and procedures that have been used to detect and characterise these molecules and an exhaustive classification of the experimental/environmental conditions that favour the formation of HCN polymers are summarised. Nucleobases, amino acids, carboxylic acids, cofactor derivatives and other compounds have been identified in HCN polymers. The great molecular diversity found in HCN polymers encourages their placement at the central core of a plausible protobiological system.

  5. Identifying the primitive path mesh in entangled polymer liquids

    International Nuclear Information System (INIS)

    Sukumaran, Sathish K.; Kremer, Kurt; Grest, Gary Stephen; Everaers, Ralf

    2004-01-01

    Similar to entangled ropes, polymer chains cannot slide through each other. These topological constraints, the so-called entanglements, dominate the viscoelastic behavior of high-molecular-weight polymeric liquids. Tube models of polymer dynamics and rheology are based on the idea that entanglements confine a chain to small fluctuations around a primitive path which follows the coarse-grained chain contour. To establish the microscopic foundation for these highly successful phenomenological models, we have recently introduced a method for identifying the primitive path mesh that characterizes the microscopic topological state of computer-generated conformations of long-chain polymer melts and solutions. Here we give a more detailed account of the algorithm and discuss several key aspects of the analysis that are pertinent for its successful use in analyzing the topology of the polymer configurations. We also present a slight modification of the algorithm that preserves the previously neglected self-entanglements and allows us to distinguish between local self-knots and entanglements between distant sections of the same chain. Our results indicate that the latter make a negligible contribution to the tube and that the contour length between local self-knots, N 1k is significantly larger than the entanglement length N e

  6. Integrating the nursing management minimum data set into the logical observation identifier names and codes system.

    Science.gov (United States)

    Subramanian, Amarnath; Westra, Bonnie; Matney, Susan; Wilson, Patricia S; Delaney, Connie W; Huff, Stan; Huff, Stanley M; Huber, Diane

    2008-11-06

    This poster describes the process used to integrate the Nursing Management Minimum Data Set (NMMDS), an instrument to measure the nursing context of care, into the Logical Observation Identifier Names and Codes (LOINC) system to facilitate contextualization of quality measures. Integration of the first three of 18 elements resulted in 48 new codes including five panels. The LOINC Clinical Committee has approved the presented mapping for their next release.

  7. Solution of the problem of the identified minimum for the tri-variate ...

    Indian Academy of Sciences (India)

    tified minimum is considered below has zero means, and distinct variances. The solution ... and a non-singular covariance matrix , where ij = ρij σi σj for i ...... (i) through (iv) above, we can use (4.29) to identify a2. 21. , a2. 31. , a2. 12. , a2. 32 uniquely. Now we consider (4.28). In this case, there are two possibilities: (A2. 1, B2.

  8. Preparing for the data revolution: identifying minimum health information competencies among the health workforce.

    Science.gov (United States)

    Whittaker, Maxine; Hodge, Nicola; Mares, Renata E; Rodney, Anna

    2015-04-01

    Health information is required for a variety of purposes at all levels of a health system, and a workforce skilled in collecting, analysing, presenting, and disseminating such information is essential to fulfil these demands. While it is established that low- and middle-income countries (LMICs) are facing shortages in human resources for health (HRH), there has been little systematic attention focussed on non-clinical competencies. In response, we developed a framework that defines the minimum health information competencies required by health workers at various levels of a health system. Using the Delphi method, we consulted with leading global health information system (HIS) experts. An initial list of competencies and draft framework were developed based on results of a systematic literature review. During the second half of 2012, we sampled 38 experts with broad-based HIS knowledge and extensive development experience. Two rounds of consultation were carried out with the same group to establish validity of the framework and gain feedback on the draft competencies. Responses from consultations were analysed using Qualtrics® software and content analysis. In round one, 17 experts agreed to participate in the consultation and 11 (65%) completed the survey. In the second round, 11 experts agreed to participate and eight (73%) completed the survey. Overall, respondents agreed that there is a need for all health workers to have basic HIS competencies and that the concept of a minimum HIS competency framework is valid. Consensus was reached around the inclusion of 68 competencies across four levels of a health system. This consultation is one of the first to identify the HIS competencies required among general health workers, as opposed to specialist HIS roles. It is also one of the first attempts to develop a framework on minimum HIS competencies needed in LMICs, highlighting the skills needed at each level of the system, and identifying potential gaps in current

  9. A comparison of approaches for finding minimum identifying codes on graphs

    Science.gov (United States)

    Horan, Victoria; Adachi, Steve; Bak, Stanley

    2016-05-01

    In order to formulate mathematical conjectures likely to be true, a number of base cases must be determined. However, many combinatorial problems are NP-hard and the computational complexity makes this research approach difficult using a standard brute force approach on a typical computer. One sample problem explored is that of finding a minimum identifying code. To work around the computational issues, a variety of methods are explored and consist of a parallel computing approach using MATLAB, an adiabatic quantum optimization approach using a D-Wave quantum annealing processor, and lastly using satisfiability modulo theory (SMT) and corresponding SMT solvers. Each of these methods requires the problem to be formulated in a unique manner. In this paper, we address the challenges of computing solutions to this NP-hard problem with respect to each of these methods.

  10. Optimal temperature profiles for minimum residual stress in the cure process of polymer composites

    CSIR Research Space (South Africa)

    Gopal, AK

    2000-01-01

    Full Text Available include the minimum residual stresses, minimum cure cycle lime and full degree of cure. The development of residual stresses during the cure cycle is one of the most important problems as they affect the strength and the mechanical properties of the final...

  11. Identifying the Minimum Model Features to Replicate Historic Morphodynamics of a Juvenile Delta

    Science.gov (United States)

    Czapiga, M. J.; Parker, G.

    2017-12-01

    We introduce a quasi-2D morphodynamic delta model that improves on past models that require many simplifying assumptions, e.g. a single channel representative of a channel network, fixed channel width, and spatially uniform deposition. Our model is useful for studying long-term progradation rates of any generic micro-tidal delta system with specification of: characteristic grain size, input water and sediment discharges and basin morphology. In particular, we relax the assumption of a single, implicit channel sweeping across the delta topset in favor of an implicit channel network. This network, coupled with recent research on channel-forming Shields number, quantitative assessments of the lateral depositional length of sand (corresponding loosely to levees) and length between bifurcations create a spatial web of deposition within the receiving basin. The depositional web includes spatial boundaries for areas infilling with sands carried as bed material load, as well as those filling via passive deposition of washload mud. Our main goal is to identify the minimum features necessary to accurately model the morphodynamics of channel number, width, depth, and overall delta progradation rate in a juvenile delta. We use the Wax Lake Delta in Louisiana as a test site due to its rapid growth in the last 40 years. Field data including topset/island bathymetry, channel bathymetry, topset/island width, channel width, number of channels, and radial topset length are compiled from US Army Corps of Engineers data for 1989, 1998, and 2006. Additional data is extracted from a DEM from 2015. These data are used as benchmarks for the hindcast model runs. The morphology of Wax Lake Delta is also strongly affected by a pre-delta substrate that acts as a lower "bedrock" boundary. Therefore, we also include closures for a bedrock-alluvial transition and an excess shear rate-law incision model to estimate bedrock incision. The model's framework is generic, but inclusion of individual

  12. Hazardous industrial gases identified using a novel polymer/MWNT composite resistance sensor array

    International Nuclear Information System (INIS)

    Yuana, C.L.; Chang, C.P.; Song, Y.

    2011-01-01

    Highlights: → In this work, a silicon wafer microelectrode substrate for a resistance sensor was fabricated using the semiconductor manufacturing process. → This work developed polymer-functionalized MWNT sensor plat forms for the detection of vapors from chemical agents at different temperatures. → Applied PCA to determine the performance of as-fabricated films for exposure to three chemical agents. - Abstract: Hazardous industrial chemical gases pose a significant threat to the environment and human life. Therefore, there is an urgent need to develop a reliable sensor for identifying these hazardous gases. In this work, a silicon wafer microelectrode substrate for a resistance sensor was fabricated using the semiconductor manufacturing process. Conductive carbon nanotubes were then mixed with six different polymers with different chemical adsorption properties to produce a composite thin film for the fabrication of a chemical sensor array. This array was then utilized to identify three hazardous gases at different temperatures. Experimental results for six polymers for chemical gases, such as tetrahydrofuran (THF), chloroform (CHCl 3 ) and methanol (MeOH) at different temperatures, indicate that the variation in sensitivity resistance increased when the sensing temperature increased. The poly(ethylene adipate)/MWNT sensing film had high sensitivity, excellent selectivity, and good reproducibility in detecting all chemical agent vapors. Additionally, this study utilized a bar chart and statistical methods in principal component analysis to identify gases with the polymer/MWNT sensor.

  13. Detecting and identifying damage in sandwich polymer composite by using acoustic emission

    Energy Technology Data Exchange (ETDEWEB)

    McGugan, M.; Soerensen, Bent F.; Oestergaard, R.; Bech, T.

    2006-12-15

    Acoustic emission is a useful monitoring tool for extracting extra information during mechanical testing of polymer composite sandwich materials. The study of fracture mechanics within test specimens extracted from wind turbine blade material is presented. The contribution of the acoustic emission monitoring technique in defining different failure modes identified during the testing is discussed. The development of in-situ structural monitoring and control systems is considered. (au)

  14. Identifying the optimal HVOF spray parameters to attain minimum porosity and maximum hardness in iron based amorphous metallic coatings

    Directory of Open Access Journals (Sweden)

    S. Vignesh

    2017-04-01

    Full Text Available Flow based Erosion – corrosion problems are very common in fluid handling equipments such as propellers, impellers, pumps in warships, submarine. Though there are many coating materials available to combat erosion–corrosion damage in the above components, iron based amorphous coatings are considered to be more effective to combat erosion–corrosion problems. High velocity oxy-fuel (HVOF spray process is considered to be a better process to coat the iron based amorphous powders. In this investigation, iron based amorphous metallic coating was developed on 316 stainless steel substrate using HVOF spray technique. Empirical relationships were developed to predict the porosity and micro hardness of iron based amorphous coating incorporating HVOF spray parameters such as oxygen flow rate, fuel flow rate, powder feed rate, carrier gas flow rate, and spray distance. Response surface methodology (RSM was used to identify the optimal HVOF spray parameters to attain coating with minimum porosity and maximum hardness.

  15. Improving Adsorption Deinking by Identifying the Optimum Balance between Polymer Beads and Deinking Chemistry

    Directory of Open Access Journals (Sweden)

    Krithika Ravi

    2016-01-01

    Full Text Available Ink removal from recovered paper is a very important process in paper and board recycling. The current deinking processes have made obvious contributions to the use of raw materials for the paper and board industries. In contrast to the flotation deinking process, in which small air bubbles are used to remove ink from the pulp, the novel and more energy-efficient method of adsorption deinking technique depends on the attachment and adsorption of ink particles on small polymer beads. The energy savings of adsorption deinking results from the fact that the process is efficient at greater stock consistencies, thus providing water conservation and savings. The present study was carried out to improve the adsorption deinking method by identifying the optimum balance between the deinking chemistry and the polymer beads. Different types of deinking solutions and polymer beads were used for this study with newsprints and mixture of newsprints and magazines. It was found that EGA 3000 solution and polyethylene terephthalate beads worked well with newspaper pulp.

  16. Resident and Facility Factors Associated With the Incidence of Urinary Tract Infections Identified in the Nursing Home Minimum Data Set.

    Science.gov (United States)

    Castle, Nicholas; Engberg, John B; Wagner, Laura M; Handler, Steven

    2017-02-01

    This research examined resident and facility-specific factors associated with a diagnosis of a urinary tract infection (UTI) in the nursing home setting. Minimum Data Set and Online Survey, Certification and Reporting system data were used to identify all nursing home residents in the United States on April 1, 2006, who did not have a UTI ( n = 1,138,418). Residents were followed until they contracted a UTI (9.5%), died (8.3%), left the nursing home (33.2%), or the year ended (49.0%). A Cox proportional hazards model was estimated, controlling for resident and facility characteristics and for the state of residence. The presence of an indwelling catheter was the primary predictor of whether a resident contracted a UTI (adjusted incidence ratio = 3.35, p factors such as percentage of Medicaid residents, for-profit, and chain status was less significant. Estimates regarding staffing levels indicate that increased contact hours with more highly educated nursing staff are associated with less catheter use. Several facility-specific risk factors are of significance. Of significance, UTIs may be reduced by modifying factors such as staffing levels.

  17. The minimum coronary artery diameter in which coronary spasm can be identified by synchrotron radiation coronary angiography

    International Nuclear Information System (INIS)

    Matsushita, Shonosuke; Hyodo, Kazuyuki; Imazuru, Tomohiro; Tokunaga, Chiho; Sato, Fujio; Enomoto, Yoshiharu; Hiramatsu, Yuji; Sakakibara, Yuzuru

    2008-01-01

    Background: Coronary vasospasm is defined as a temporary, intense narrowing of the coronary conduit artery. It brings about ischemic chest pain and becomes one of the causes of myocardial infarction. Coronary spasms are divided into two categories. One is the coronary spasm of the conduit artery and the other is the coronary microvascular spasm. Although coronary spasms are diagnosed with the images of coronary angiography, microvascular spasms cannot be diagnosed because of the limitations of conventional angiographic systems. However, synchrotron radiation coronary angiography (SRCA) can identify coronary arteries down to 100 μm in diameter in the beating heart and 50 μm in arrested heart. Aim: The purpose of this study was to confirm whether microvascular spasms could be identified or not using SRCA, and then down that size identification was possible. Methods: The Langendorff perfusion system with isolated rat hearts was employed. Krebs-Henseleit solution (KH solution) was used as a perfusate. 10 mM of 4-aminopyridine (4-AP: a voltage-gated potassium channel blocker; spasm inducer) was added to the KH solution and maintained for 5 min. SRCA was performed at pre-, during and 10 min after cessation of the KH solution with 4-AP. Coronary spasms were defined as a temporal 75% reduction of coronary arterial diameter. Results and conclusion: Multiple sizes of coronary arteries showed coronary spasms. The minimum stenosed coronary artery size was 100 μm. Since coronary microvascular spasms are seen in the arterioles (50-400 μm), coronary microvascular spasms may be diagnosed with the use of synchrotron radiation coronary angiography

  18. Minimum Description Length Block Finder, a Method to Identify Haplotype Blocks and to Compare the Strength of Block Boundaries

    OpenAIRE

    Mannila, H.; Koivisto, M.; Perola, M.; Varilo, T.; Hennah, W.; Ekelund, J.; Lukk, M.; Peltonen, L.; Ukkonen, E.

    2003-01-01

    We describe a new probabilistic method for finding haplotype blocks that is based on the use of the minimum description length (MDL) principle. We give a rigorous definition of the quality of a segmentation of a genomic region into blocks and describe a dynamic programming algorithm for finding the optimal segmentation with respect to this measure. We also describe a method for finding the probability of a block boundary for each pair of adjacent markers: this gives a tool for evaluating the ...

  19. Minimum description length block finder, a method to identify haplotype blocks and to compare the strength of block boundaries.

    Science.gov (United States)

    Mannila, H; Koivisto, M; Perola, M; Varilo, T; Hennah, W; Ekelund, J; Lukk, M; Peltonen, L; Ukkonen, E

    2003-07-01

    We describe a new probabilistic method for finding haplotype blocks that is based on the use of the minimum description length (MDL) principle. We give a rigorous definition of the quality of a segmentation of a genomic region into blocks and describe a dynamic programming algorithm for finding the optimal segmentation with respect to this measure. We also describe a method for finding the probability of a block boundary for each pair of adjacent markers: this gives a tool for evaluating the significance of each block boundary. We have applied the method to the published data of Daly and colleagues. The results expose some problems that exist in the current methods for the evaluation of the significance of predicted block boundaries. Our method, MDL block finder, can be used to compare block borders in different sample sets, and we demonstrate this by applying the MDL-based method to define the block structure in chromosomes from population isolates.

  20. Validation of ATR FT-IR to identify polymers of plastic marine debris, including those ingested by marine organisms

    Science.gov (United States)

    Jung, Melissa R.; Horgen, F. David; Orski, Sara V.; Rodriguez, Viviana; Beers, Kathryn L.; Balazs, George H.; Jones, T. Todd; Work, Thierry M.; Brignac, Kayla C.; Royer, Sarah-Jeanne; Hyrenbach, David K.; Jensen, Brenda A.; Lynch, Jennifer M.

    2018-01-01

    Polymer identification of plastic marine debris can help identify its sources, degradation, and fate. We optimized and validated a fast, simple, and accessible technique, attenuated total reflectance Fourier transform infrared spectroscopy (ATR FT-IR), to identify polymers contained in plastic ingested by sea turtles. Spectra of consumer good items with known resin identification codes #1–6 and several #7 plastics were compared to standard and raw manufactured polymers. High temperature size exclusion chromatography measurements confirmed ATR FT-IR could differentiate these polymers. High-density (HDPE) and low-density polyethylene (LDPE) discrimination is challenging but a clear step-by-step guide is provided that identified 78% of ingested PE samples. The optimal cleaning methods consisted of wiping ingested pieces with water or cutting. Of 828 ingested plastics pieces from 50 Pacific sea turtles, 96% were identified by ATR FT-IR as HDPE, LDPE, unknown PE, polypropylene (PP), PE and PP mixtures, polystyrene, polyvinyl chloride, and nylon.

  1. System and method employing a minimum distance and a load feature database to identify electric load types of different electric loads

    Science.gov (United States)

    Lu, Bin; Yang, Yi; Sharma, Santosh K; Zambare, Prachi; Madane, Mayura A

    2014-12-23

    A method identifies electric load types of a plurality of different electric loads. The method includes providing a load feature database of a plurality of different electric load types, each of the different electric load types including a first load feature vector having at least four different load features; sensing a voltage signal and a current signal for each of the different electric loads; determining a second load feature vector comprising at least four different load features from the sensed voltage signal and the sensed current signal for a corresponding one of the different electric loads; and identifying by a processor one of the different electric load types by determining a minimum distance of the second load feature vector to the first load feature vector of the different electric load types of the load feature database.

  2. Effect of culture medium on polymer production and temperature on recovery of polymer produced from newly identified Rhyzopus oryzae ST29

    Directory of Open Access Journals (Sweden)

    Tipparat Hongpattarakere

    2008-04-01

    Full Text Available Thermotolerant fungal isolate ST29 was identified by observing on cell morphology and molecular technique based on internal transcribed spacer (ITS gene to be Rhizopus oryzae. Among four culture media tested, the strain exhibited the highest growth in yeast malt extract (YM medium (4.87 g/l, followed by Sabouraud dextrose broth (SDB (4.25 g/l, potato dextrose broth (PDB (4.10 g/l and palm oil mill effluent (POME (3.29 g/l, respectively, after 4 days cultivation at 45oC. However, the strain was found to produce polymer only in POME medium at 45oC, but not in the three synthetic media tested. Effect of temperature on separation of the biopolymer produced by this fungal strain was studied by incubating the culture broth in water bath with temperatures in the range of room temperature to 70oC. The biopolymer was recovered by filtration, centrifugation, and precipitation by adding 4 volumes of 95% ethanol, then freeze-drying. These temperatures therefore had no influence on the biopolymer yields (5.58-5.78 g/l or on biomass yields (2.90-3.29 g/l.

  3. Intense volume reduction of mixed and low-level waste, solidification in sulphur polymer concrete, and excellent disposal at minimum cost

    International Nuclear Information System (INIS)

    Darnell, G.R.

    1990-01-01

    Progressive changes in regulations governing the disposal of the nation's radioactive and hazardous wastes demand the development of more advanced treatment and disposal systems. The U.S. Department of Energy's Radioactive Waste Technology Support Program (formerly the Defense Low-Level Waste Management Program) was given the task of demonstrating the degree of excellence that could be achieved at reasonable cost using existing technology. The resulting concept is a Waste Treatment and Disposal Complex that will fully treat contact-handled mixed and low-level radioactive waste to a disposable product that is totally liquid-free and approximately 98% inorganic. An excellent volume reduction factor is achieved through sorting, sizing, incineration, vitrification, and final grouting. Inorganic waste items larger than 1/4 in. will be placed in inexpensive, uniform-sized, smooth-sided, thin-walled steel boxes. The smaller particles will be mixed with sulfur polymer concrete and pumped into the boxes, filling most voids. The appendage-free boxes measuring 1 by 1 by 1 m will be stacked tightly in an abovegrade, earth-mounded, concrete disposal vault where a temporary roof will protect them from rain and snow. A concrete roof poured directly on top of the dense, essentially voidless waste stack will be topped by an engineered, water-shedding earthen cover. Total cost for design, construction, testing, 30 years of treatment and disposal, administration, decontamination and decommissioning, site closure, and postclosure monitoring and maintenance will cost less per cubic foot than is currently expended for subsurface disposal. A radiological performance assessment shows this concept will exceed the nation's existing disposal systems and governmental performance objectives for the protection of the general public by a factor of 30,000

  4. A Space Experiment to Measure the Atomic Oxygen Erosion of Polymers and Demonstrate a Technique to Identify Sources of Silicone Contamination

    Science.gov (United States)

    Banks, Bruce A.; deGroh, Kim K.; Baney-Barton, Elyse; Sechkar, Edward A.; Hunt, Patricia K.; Willoughby, Alan; Bemer, Meagan; Hope, Stephanie; Koo, Julie; Kaminski, Carolyn; hide

    1999-01-01

    A low Earth orbital space experiment entitled, "Polymers Erosion And Contamination Experiment", (PEACE) has been designed as a Get-Away Special (GAS Can) experiment to be accommodated as a Shuttle in-bay environmental exposure experiment. The first objective is to measure the atomic oxygen erosion yields of approximately 40 different polymeric materials by mass loss and erosion measurements using atomic force microscopy. The second objective is to evaluate the capability of identifying sources of silicone contamination through the use of a pin-hole contamination camera which utilizes environmental atomic oxygen to produce a contaminant source image on an optical substrate.

  5. Polymer films

    Science.gov (United States)

    Granick, Steve; Sukhishvili, Svetlana A.

    2004-05-25

    A film contains a first polymer having a plurality of hydrogen bond donating moieties, and a second polymer having a plurality of hydrogen bond accepting moieties. The second polymer is hydrogen bonded to the first polymer.

  6. Minimum Wages and Poverty

    OpenAIRE

    Fields, Gary S.; Kanbur, Ravi

    2005-01-01

    Textbook analysis tells us that in a competitive labor market, the introduction of a minimum wage above the competitive equilibrium wage will cause unemployment. This paper makes two contributions to the basic theory of the minimum wage. First, we analyze the effects of a higher minimum wage in terms of poverty rather than in terms of unemployment. Second, we extend the standard textbook model to allow for incomesharing between the employed and the unemployed. We find that there are situation...

  7. Development of a novel test-setup for identifying the frictional characteristics of carbon fibre reinforced polymer composites at high surface pressure

    Science.gov (United States)

    Saxena, Prateek; Schinzel, Marie; Andrich, Manuela; Modler, Niels

    2016-09-01

    Carbon fibre reinforced polymer composites are extensively used in industrial applications. They are light in weight and have excellent load bearing properties. To understand this material's behaviour when carrying loads at high pressure, a tensile-friction test device was developed that can apply a contact surface pressure between composite and counterpart of 50-300 MPa. A tribological investigation of carbon fibre reinforced epoxy composites was carried out, in which the influence of the surface morphology was investigated by using grinding and sandblasting techniques. The friction coefficient of the polymer composite was measured at 100 MPa surface pressure against uncoated and Diamond-Like Carbon coated stainless steel counterparts.

  8. 21 CFR 172.770 - Ethylene oxide polymer.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethylene oxide polymer. 172.770 Section 172.770... CONSUMPTION Other Specific Usage Additives § 172.770 Ethylene oxide polymer. The polymer of ethylene oxide may... conditions. (a) It is the polymer of ethylene oxide having a minimum viscosity of 1,500 centipoises in a 1...

  9. Minimum critical mass systems

    International Nuclear Information System (INIS)

    Dam, H. van; Leege, P.F.A. de

    1987-01-01

    An analysis is presented of thermal systems with minimum critical mass, based on the use of materials with optimum neutron moderating and reflecting properties. The optimum fissile material distributions in the systems are obtained by calculations with standard computer codes, extended with a routine for flat fuel importance search. It is shown that in the minimum critical mass configuration a considerable part of the fuel is positioned in the reflector region. For 239 Pu a minimum critical mass of 87 g is found, which is the lowest value reported hitherto. (author)

  10. Minimum entropy production principle

    Czech Academy of Sciences Publication Activity Database

    Maes, C.; Netočný, Karel

    2013-01-01

    Roč. 8, č. 7 (2013), s. 9664-9677 ISSN 1941-6016 Institutional support: RVO:68378271 Keywords : MINEP Subject RIV: BE - Theoretical Physics http://www.scholarpedia.org/article/Minimum_entropy_production_principle

  11. Biodegradable Polymers

    OpenAIRE

    Vroman, Isabelle; Tighzert, Lan

    2009-01-01

    Biodegradable materials are used in packaging, agriculture, medicine and other areas. In recent years there has been an increase in interest in biodegradable polymers. Two classes of biodegradable polymers can be distinguished: synthetic or natural polymers. There are polymers produced from feedstocks derived either from petroleum resources (non renewable resources) or from biological resources (renewable resources). In general natural polymers offer fewer advantages than synthetic polymers. ...

  12. Polymer compound

    NARCIS (Netherlands)

    1995-01-01

    A Polymer compound comprising a polymer (a) that contains cyclic imidesgroups and a polymer (b) that contains monomer groups with a 2,4-diamino-1,3,5-triazine side group. According to the formula (see formula) whereby themole percentage ratio of the cyclic imides groups in the polymer compoundwith

  13. Polymer electronics

    CERN Document Server

    Hsin-Fei, Meng

    2013-01-01

    Polymer semiconductor is the only semiconductor that can be processed in solution. Electronics made by these flexible materials have many advantages such as large-area solution process, low cost, and high performance. Researchers and companies are increasingly dedicating time and money in polymer electronics. This book focuses on the fundamental materials and device physics of polymer electronics. It describes polymer light-emitting diodes, polymer field-effect transistors, organic vertical transistors, polymer solar cells, and many applications based on polymer electronics. The book also disc

  14. Rising above the Minimum Wage.

    Science.gov (United States)

    Even, William; Macpherson, David

    An in-depth analysis was made of how quickly most people move up the wage scale from minimum wage, what factors influence their progress, and how minimum wage increases affect wage growth above the minimum. Very few workers remain at the minimum wage over the long run, according to this study of data drawn from the 1977-78 May Current Population…

  15. PHOTOREFRACTIVE POLYMERS

    NARCIS (Netherlands)

    Morichere, D; Malliaras, G.G; Krasnikov, V.V.; Bolink, H.J; Hadziioannou, G

    The use of polymers as photorefractive materials offers many advantages : flexibility in synthesis, doping, processing and low cost. The required functionalities responsible for photorefractivity, namely charge generation, transport, trapping and linear electrooptic effect are given in the polymer

  16. Photorefractive polymers

    NARCIS (Netherlands)

    Bolink, Hendrik Jan; Hadziioannou, G

    1997-01-01

    This thesis describes the synthesis and properties of photorefractive polymers. Photorefractive polymers are materials in which the refractive index can be varied by the interaction with light. Unlike in numerous other photosensitive materials, in photorefractive materials this occurs via

  17. Minimum Error Entropy Classification

    CERN Document Server

    Marques de Sá, Joaquim P; Santos, Jorge M F; Alexandre, Luís A

    2013-01-01

    This book explains the minimum error entropy (MEE) concept applied to data classification machines. Theoretical results on the inner workings of the MEE concept, in its application to solving a variety of classification problems, are presented in the wider realm of risk functionals. Researchers and practitioners also find in the book a detailed presentation of practical data classifiers using MEE. These include multi‐layer perceptrons, recurrent neural networks, complexvalued neural networks, modular neural networks, and decision trees. A clustering algorithm using a MEE‐like concept is also presented. Examples, tests, evaluation experiments and comparison with similar machines using classic approaches, complement the descriptions.

  18. Polymer Brushes

    NARCIS (Netherlands)

    Vos, de W.M.; Kleijn, J.M.; Keizer, de A.; Cosgrove, T.; Cohen Stuart, M.A.

    2010-01-01

    A polymer brush can be defined as a dense array of polymers end-attached to an interface that stretch out into the surrounding medium. Polymer brushes have been investigated for the past 30 years and have shown to be an extremely useful tool to control interfacial properties. This review is intended

  19. Do Minimum Wages Fight Poverty?

    OpenAIRE

    David Neumark; William Wascher

    1997-01-01

    The primary goal of a national minimum wage floor is to raise the incomes of poor or near-poor families with members in the work force. However, estimates of employment effects of minimum wages tell us little about whether minimum wages are can achieve this goal; even if the disemployment effects of minimum wages are modest, minimum wage increases could result in net income losses for poor families. We present evidence on the effects of minimum wages on family incomes from matched March CPS s...

  20. Employment effects of minimum wages

    OpenAIRE

    Neumark, David

    2014-01-01

    The potential benefits of higher minimum wages come from the higher wages for affected workers, some of whom are in low-income families. The potential downside is that a higher minimum wage may discourage employers from using the low-wage, low-skill workers that minimum wages are intended to help. Research findings are not unanimous, but evidence from many countries suggests that minimum wages reduce the jobs available to low-skill workers.

  1. 75 FR 6151 - Minimum Capital

    Science.gov (United States)

    2010-02-08

    ... capital and reserve requirements to be issued by order or regulation with respect to a product or activity... minimum capital requirements. Section 1362(a) establishes a minimum capital level for the Enterprises... entities required under this section.\\6\\ \\3\\ The Bank Act's current minimum capital requirements apply to...

  2. Rapid Polymer Sequencer

    Science.gov (United States)

    Stolc, Viktor (Inventor); Brock, Matthew W (Inventor)

    2013-01-01

    Method and system for rapid and accurate determination of each of a sequence of unknown polymer components, such as nucleic acid components. A self-assembling monolayer of a selected substance is optionally provided on an interior surface of a pipette tip, and the interior surface is immersed in a selected liquid. A selected electrical field is impressed in a longitudinal direction, or in a transverse direction, in the tip region, a polymer sequence is passed through the tip region, and a change in an electrical current signal is measured as each polymer component passes through the tip region. Each of the measured changes in electrical current signals is compared with a database of reference electrical change signals, with each reference signal corresponding to an identified polymer component, to identify the unknown polymer component with a reference polymer component. The nanopore preferably has a pore inner diameter of no more than about 40 nm and is prepared by heating and pulling a very small section of a glass tubing.

  3. Polymer Electrolytes

    Science.gov (United States)

    Hallinan, Daniel T.; Balsara, Nitash P.

    2013-07-01

    This review article covers applications in which polymer electrolytes are used: lithium batteries, fuel cells, and water desalination. The ideas of electrochemical potential, salt activity, and ion transport are presented in the context of these applications. Potential is defined, and we show how a cell potential measurement can be used to ascertain salt activity. The transport parameters needed to fully specify a binary electrolyte (salt + solvent) are presented. We define five fundamentally different types of homogeneous electrolytes: type I (classical liquid electrolytes), type II (gel electrolytes), type III (dry polymer electrolytes), type IV (dry single-ion-conducting polymer electrolytes), and type V (solvated single-ion-conducting polymer electrolytes). Typical values of transport parameters are provided for all types of electrolytes. Comparison among the values provides insight into the transport mechanisms occurring in polymer electrolytes. It is desirable to decouple the mechanical properties of polymer electrolyte membranes from the ionic conductivity. One way to accomplish this is through the development of microphase-separated polymers, wherein one of the microphases conducts ions while the other enhances the mechanical rigidity of the heterogeneous polymer electrolyte. We cover all three types of conducting polymer electrolyte phases (types III, IV, and V). We present a simple framework that relates the transport parameters of heterogeneous electrolytes to homogeneous analogs. We conclude by discussing electrochemical stability of electrolytes and the effects of water contamination because of their relevance to applications such as lithium ion batteries.

  4. Star Polymers.

    Science.gov (United States)

    Ren, Jing M; McKenzie, Thomas G; Fu, Qiang; Wong, Edgar H H; Xu, Jiangtao; An, Zesheng; Shanmugam, Sivaprakash; Davis, Thomas P; Boyer, Cyrille; Qiao, Greg G

    2016-06-22

    Recent advances in controlled/living polymerization techniques and highly efficient coupling chemistries have enabled the facile synthesis of complex polymer architectures with controlled dimensions and functionality. As an example, star polymers consist of many linear polymers fused at a central point with a large number of chain end functionalities. Owing to this exclusive structure, star polymers exhibit some remarkable characteristics and properties unattainable by simple linear polymers. Hence, they constitute a unique class of technologically important nanomaterials that have been utilized or are currently under audition for many applications in life sciences and nanotechnologies. This article first provides a comprehensive summary of synthetic strategies towards star polymers, then reviews the latest developments in the synthesis and characterization methods of star macromolecules, and lastly outlines emerging applications and current commercial use of star-shaped polymers. The aim of this work is to promote star polymer research, generate new avenues of scientific investigation, and provide contemporary perspectives on chemical innovation that may expedite the commercialization of new star nanomaterials. We envision in the not-too-distant future star polymers will play an increasingly important role in materials science and nanotechnology in both academic and industrial settings.

  5. Polymer chemistry (revised edition)

    International Nuclear Information System (INIS)

    Kim, Jae Mum

    1987-02-01

    This book deals with polymer chemistry, which is divided into fourteen chapters. The contents of this book are development of polymer chemistry, conception of polymer, measurement of polymer chemistry, conception of polymer, measurement of polymer, molecule structure of polymer, thermal prosperities of solid polymer, basic theory of polymerization, radical polymerization, ion polymerization, radical polymerization, copolymerization, polymerization by step-reaction, polymer reaction, crown polymer and inorganic polymer on classification and process of creation such as polymeric sulfur and carbon fiber.

  6. 40 CFR 721.8090 - Polyurethane polymer.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Polyurethane polymer. 721.8090 Section... Substances § 721.8090 Polyurethane polymer. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a polyurethane polymer (P-94-47) is subject...

  7. The Minimum Wage, Restaurant Prices, and Labor Market Structure

    Science.gov (United States)

    Aaronson, Daniel; French, Eric; MacDonald, James

    2008-01-01

    Using store-level and aggregated Consumer Price Index data, we show that restaurant prices rise in response to minimum wage increases under several sources of identifying variation. We introduce a general model of employment determination that implies minimum wage hikes cause prices to rise in competitive labor markets but potentially fall in…

  8. Polymer Nanocomposites

    Indian Academy of Sciences (India)

    methods for the synthesis of polymer nanocomposites. In this article we .... ers, raw materials recovery, drug delivery and anticorrosion .... region giving rise to dose-packed absorption bands called an IR ... using quaternary ammonium salts.

  9. Se of polymers to control clay swelling

    Energy Technology Data Exchange (ETDEWEB)

    Slobod, R L; Beiswanger, J P.G.

    1968-01-01

    The injection of water to displace oil is one of the main methods used to increase oil recovery. High injection rates are generally desired, and in some cases the flood will not be economic unless high rates are maintained. The presence of clays which swell in the presence of water offers a complication to the problem of maintaining adequate injectivity. In the course of this study it was observed that certain polymers, when present in dilute concentrations in the water, had the ability to reduce the response of these clays to fresh water. Two polymers, one an anionic and the other nonionic, were found to be very effective in controlling the clays present in Berea cores. Successful control of clay swelling was obtained by use of solutions containing as little as 1.0 ppM of polymer, but at this low concentration appreciable volumes of treating solution were required. These results suggest that some minimum amount of polymer must be adsorbed to prevent clay swelling. In Berea sandstone this minimum amount appeared to be of the order of 0.03 mg per cc of pore space. A series of tests made using 10.0 ppM polymer showed that the polymer could be made through the porous system in which 0.066 per mg of polymer was adsorbed per cc of pore space.

  10. Polymer nanocomposites: polymer and particle dynamics

    KAUST Repository

    Kim, Daniel; Srivastava, Samanvaya; Narayanan, Suresh; Archer, Lynden A.

    2012-01-01

    Polymer nanocomposites containing nanoparticles smaller than the random coil size of their host polymer chains are known to exhibit unique properties, such as lower viscosity and glass transition temperature relative to the neat polymer melt. It has

  11. Antimocrobial Polymer

    Science.gov (United States)

    McDonald, William F.; Huang, Zhi-Heng; Wright, Stacy C.

    2005-09-06

    A polymeric composition having antimicrobial properties and a process for rendering the surface of a substrate antimicrobial are disclosed. The composition comprises a crosslinked chemical combination of (i) a polymer having amino group-containing side chains along a backbone forming the polymer, (ii) an antimicrobial agent selected from quaternary ammonium compounds, gentian violet compounds, substituted or unsubstituted phenols, biguanide compounds, iodine compounds, and mixtures thereof, and (iii) a crosslinking agent containing functional groups capable of reacting with the amino groups. In one embodiment, the polymer is a polyamide formed from a maleic anhydride or maleic acid ester monomer and alkylamines thereby producing a polyamide having amino substituted alkyl chains on one side of the polyamide backbone; the crosslinking agent is a phosphine having the general formula (A)3P wherein A is hydroxyalkyl; and the antimicrobial agent is chlorhexidine, dimethylchlorophenol, cetyl pyridinium chloride, gentian violet, triclosan, thymol, iodine, and mixtures thereof.

  12. Polymer electronics

    CERN Document Server

    Geoghegan, Mark

    2013-01-01

    Polymer electronics is the science behind many important new developments in technology, such as the flexible electronic display (e-ink) and many new developments in transistor technology. Solar cells, light-emitting diodes, and transistors are all areas where plastic electronics is likely to, or is already having, a serious impact on our daily lives. With polymer transistors and light-emitting diodes now being commercialised, there is a clear need for a pedagogic text thatdiscusses the subject in a clear and concise fashion suitable for senior undergraduate and graduate students. The content

  13. Comments on the 'minimum flux corona' concept

    International Nuclear Information System (INIS)

    Antiochos, S.K.; Underwood, J.H.

    1978-01-01

    Hearn's (1975) models of the energy balance and mass loss of stellar coronae, based on a 'minimum flux corona' concept, are critically examined. First, it is shown that the neglect of the relevant length scales for coronal temperature variation leads to an inconsistent computation of the total energy flux F. The stability arguments upon which the minimum flux concept is based are shown to be fallacious. Errors in the computation of the stellar wind contribution to the energy budget are identified. Finally we criticize Hearn's (1977) suggestion that the model, with a value of the thermal conductivity modified by the magnetic field, can explain the difference between solar coronal holes and quiet coronal regions. (orig.) 891 WL [de

  14. Minimum Q Electrically Small Antennas

    DEFF Research Database (Denmark)

    Kim, O. S.

    2012-01-01

    Theoretically, the minimum radiation quality factor Q of an isolated resonance can be achieved in a spherical electrically small antenna by combining TM1m and TE1m spherical modes, provided that the stored energy in the antenna spherical volume is totally suppressed. Using closed-form expressions...... for a multiarm spherical helix antenna confirm the theoretical predictions. For example, a 4-arm spherical helix antenna with a magnetic-coated perfectly electrically conducting core (ka=0.254) exhibits the Q of 0.66 times the Chu lower bound, or 1.25 times the minimum Q....

  15. Polymer physics

    CERN Document Server

    Gedde, Ulf W

    1999-01-01

    This book is the result of my teaching efforts during the last ten years at the Royal Institute of Technology. The purpose is to present the subject of polymer physics for undergraduate and graduate students, to focus the fundamental aspects of the subject and to show the link between experiments and theory. The intention is not to present a compilation of the currently available literature on the subject. Very few reference citations have thus been made. Each chapter has essentially the same structure: starling with an introduction, continuing with the actual subject, summarizing the chapter in 30D-500 words, and finally presenting problems and a list of relevant references for the reader. The solutions to the problems presented in Chapters 1-12 are given in Chapter 13. The theme of the book is essentially polymer science, with the exclusion of that part dealing directly with chemical reactions. The fundamentals in polymer science, including some basic polymer chemistry, are presented as an introduction in t...

  16. Antimicrobial polymers.

    Science.gov (United States)

    Jain, Anjali; Duvvuri, L Sailaja; Farah, Shady; Beyth, Nurit; Domb, Abraham J; Khan, Wahid

    2014-12-01

    Better health is basic requirement of human being, but the rapid growth of harmful pathogens and their serious health effects pose a significant challenge to modern science. Infections by pathogenic microorganisms are of great concern in many fields such as medical devices, drugs, hospital surfaces/furniture, dental restoration, surgery equipment, health care products, and hygienic applications (e.g., water purification systems, textiles, food packaging and storage, major or domestic appliances etc.) Antimicrobial polymers are the materials having the capability to kill/inhibit the growth of microbes on their surface or surrounding environment. Recently, they gained considerable interest for both academic research and industry and were found to be better than their small molecular counterparts in terms of enhanced efficacy, reduced toxicity, minimized environmental problems, resistance, and prolonged lifetime. Hence, efforts have focused on the development of antimicrobial polymers with all desired characters for optimum activity. In this Review, an overview of different antimicrobial polymers, their mechanism of action, factors affecting antimicrobial activity, and application in various fields are given. Recent advances and the current clinical status of these polymers are also discussed. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Fermat and the Minimum Principle

    Indian Academy of Sciences (India)

    Arguably, least action and minimum principles were offered or applied much earlier. This (or these) principle(s) is/are among the fundamental, basic, unifying or organizing ones used to describe a variety of natural phenomena. It considers the amount of energy expended in performing a given action to be the least required ...

  18. Coupling between minimum scattering antennas

    DEFF Research Database (Denmark)

    Andersen, J.; Lessow, H; Schjær-Jacobsen, Hans

    1974-01-01

    Coupling between minimum scattering antennas (MSA's) is investigated by the coupling theory developed by Wasylkiwskyj and Kahn. Only rotationally symmetric power patterns are considered, and graphs of relative mutual impedance are presented as a function of distance and pattern parameters. Crossed...

  19. Design for minimum energy in interstellar communication

    Science.gov (United States)

    Messerschmitt, David G.

    2015-02-01

    Microwave digital communication at interstellar distances is the foundation of extraterrestrial civilization (SETI and METI) communication of information-bearing signals. Large distances demand large transmitted power and/or large antennas, while the propagation is transparent over a wide bandwidth. Recognizing a fundamental tradeoff, reduced energy delivered to the receiver at the expense of wide bandwidth (the opposite of terrestrial objectives) is advantageous. Wide bandwidth also results in simpler design and implementation, allowing circumvention of dispersion and scattering arising in the interstellar medium and motion effects and obviating any related processing. The minimum energy delivered to the receiver per bit of information is determined by cosmic microwave background alone. By mapping a single bit onto a carrier burst, the Morse code invented for the telegraph in 1836 comes closer to this minimum energy than approaches used in modern terrestrial radio. Rather than the terrestrial approach of adding phases and amplitudes increases information capacity while minimizing bandwidth, adding multiple time-frequency locations for carrier bursts increases capacity while minimizing energy per information bit. The resulting location code is simple and yet can approach the minimum energy as bandwidth is expanded. It is consistent with easy discovery, since carrier bursts are energetic and straightforward modifications to post-detection pattern recognition can identify burst patterns. Time and frequency coherence constraints leading to simple signal discovery are addressed, and observations of the interstellar medium by transmitter and receiver constrain the burst parameters and limit the search scope.

  20. State cigarette minimum price laws - United States, 2009.

    Science.gov (United States)

    2010-04-09

    Cigarette price increases reduce the demand for cigarettes and thereby reduce smoking prevalence, cigarette consumption, and youth initiation of smoking. Excise tax increases are the most effective government intervention to increase the price of cigarettes, but cigarette manufacturers use trade discounts, coupons, and other promotions to counteract the effects of these tax increases and appeal to price-sensitive smokers. State cigarette minimum price laws, initiated by states in the 1940s and 1950s to protect tobacco retailers from predatory business practices, typically require a minimum percentage markup to be added to the wholesale and/or retail price. If a statute prohibits trade discounts from the minimum price calculation, these laws have the potential to counteract discounting by cigarette manufacturers. To assess the status of cigarette minimum price laws in the United States, CDC surveyed state statutes and identified those states with minimum price laws in effect as of December 31, 2009. This report summarizes the results of that survey, which determined that 25 states had minimum price laws for cigarettes (median wholesale markup: 4.00%; median retail markup: 8.00%), and seven of those states also expressly prohibited the use of trade discounts in the minimum retail price calculation. Minimum price laws can help prevent trade discounting from eroding the positive effects of state excise tax increases and higher cigarette prices on public health.

  1. Minimum airflow reset of single-duct VAV terminal boxes

    Science.gov (United States)

    Cho, Young-Hum

    Single duct Variable Air Volume (VAV) systems are currently the most widely used type of HVAC system in the United States. When installing such a system, it is critical to determine the minimum airflow set point of the terminal box, as an optimally selected set point will improve the level of thermal comfort and indoor air quality (IAQ) while at the same time lower overall energy costs. In principle, this minimum rate should be calculated according to the minimum ventilation requirement based on ASHRAE standard 62.1 and maximum heating load of the zone. Several factors must be carefully considered when calculating this minimum rate. Terminal boxes with conventional control sequences may result in occupant discomfort and energy waste. If the minimum rate of airflow is set too high, the AHUs will consume excess fan power, and the terminal boxes may cause significant simultaneous room heating and cooling. At the same time, a rate that is too low will result in poor air circulation and indoor air quality in the air-conditioned space. Currently, many scholars are investigating how to change the algorithm of the advanced VAV terminal box controller without retrofitting. Some of these controllers have been found to effectively improve thermal comfort, indoor air quality, and energy efficiency. However, minimum airflow set points have not yet been identified, nor has controller performance been verified in confirmed studies. In this study, control algorithms were developed that automatically identify and reset terminal box minimum airflow set points, thereby improving indoor air quality and thermal comfort levels, and reducing the overall rate of energy consumption. A theoretical analysis of the optimal minimum airflow and discharge air temperature was performed to identify the potential energy benefits of resetting the terminal box minimum airflow set points. Applicable control algorithms for calculating the ideal values for the minimum airflow reset were developed and

  2. Polymer blends

    Energy Technology Data Exchange (ETDEWEB)

    Allen, Scott D.; Naik, Sanjeev

    2017-08-22

    The present invention provides, among other things, extruded blends of aliphatic polycarbonates and polyolefins. In one aspect, provided blends comprise aliphatic polycarbonates such as poly(propylene carbonate) and a lesser amount of a crystalline or semicrystalline polymer. In certain embodiments, provided blends are characterized in that they exhibit unexpected improvements in their elongation properties. In another aspect, the invention provides methods of making such materials and applications of the materials in applications such as the manufacture of consumer packaging materials.

  3. Pay equity, minimum wage and equality at work

    OpenAIRE

    Rubery, Jill

    2003-01-01

    Reviews the underlying causes of pay discrimination embedded within the organization of the labour market and structures of pay and reward. Discusses the need to focus on pay equity as part of a general strategy of promoting equity and decent work and examines the case for using minimum wage policies in comparison to more targeted equal pay policies to reduce gender pay equity. Identifies potential obstacles to or support for such policies and describes experiences of the use of minimum wages...

  4. Quantum mechanics the theoretical minimum

    CERN Document Server

    Susskind, Leonard

    2014-01-01

    From the bestselling author of The Theoretical Minimum, an accessible introduction to the math and science of quantum mechanicsQuantum Mechanics is a (second) book for anyone who wants to learn how to think like a physicist. In this follow-up to the bestselling The Theoretical Minimum, physicist Leonard Susskind and data engineer Art Friedman offer a first course in the theory and associated mathematics of the strange world of quantum mechanics. Quantum Mechanics presents Susskind and Friedman’s crystal-clear explanations of the principles of quantum states, uncertainty and time dependence, entanglement, and particle and wave states, among other topics. An accessible but rigorous introduction to a famously difficult topic, Quantum Mechanics provides a tool kit for amateur scientists to learn physics at their own pace.

  5. Minimum resolvable power contrast model

    Science.gov (United States)

    Qian, Shuai; Wang, Xia; Zhou, Jingjing

    2018-01-01

    Signal-to-noise ratio and MTF are important indexs to evaluate the performance of optical systems. However,whether they are used alone or joint assessment cannot intuitively describe the overall performance of the system. Therefore, an index is proposed to reflect the comprehensive system performance-Minimum Resolvable Radiation Performance Contrast (MRP) model. MRP is an evaluation model without human eyes. It starts from the radiance of the target and the background, transforms the target and background into the equivalent strips,and considers attenuation of the atmosphere, the optical imaging system, and the detector. Combining with the signal-to-noise ratio and the MTF, the Minimum Resolvable Radiation Performance Contrast is obtained. Finally the detection probability model of MRP is given.

  6. Polymers for hydrogen infrastructure and vehicle fuel systems :

    Energy Technology Data Exchange (ETDEWEB)

    Barth, Rachel Reina; Simmons, Kevin L.; San Marchi, Christopher W.

    2013-10-01

    This document addresses polymer materials for use in hydrogen service. Section 1 summarizes the applications of polymers in hydrogen infrastructure and vehicle fuel systems and identifies polymers used in these applications. Section 2 reviews the properties of polymer materials exposed to hydrogen and/or high-pressure environments, using information obtained from published, peer-reviewed literature. The effect of high pressure on physical and mechanical properties of polymers is emphasized in this section along with a summary of hydrogen transport through polymers. Section 3 identifies areas in which fuller characterization is needed in order to assess material suitability for hydrogen service.

  7. Understanding the Minimum Wage: Issues and Answers.

    Science.gov (United States)

    Employment Policies Inst. Foundation, Washington, DC.

    This booklet, which is designed to clarify facts regarding the minimum wage's impact on marketplace economics, contains a total of 31 questions and answers pertaining to the following topics: relationship between minimum wages and poverty; impacts of changes in the minimum wage on welfare reform; and possible effects of changes in the minimum wage…

  8. 5 CFR 551.301 - Minimum wage.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Minimum wage. 551.301 Section 551.301... FAIR LABOR STANDARDS ACT Minimum Wage Provisions Basic Provision § 551.301 Minimum wage. (a)(1) Except... employees wages at rates not less than the minimum wage specified in section 6(a)(1) of the Act for all...

  9. Electrical conductivity of polyaniline doped PVC–PMMA polymer ...

    Indian Academy of Sciences (India)

    which has now become one of the hot topics of research. (Radhakrishnan 2001). ... and sensitive methods for studying the polymer structure. (Ferraro and Walkar ... acceptor mixed polymers doped with polyaniline, was measured to identify ...

  10. Subgap Absorption in Conjugated Polymers

    Science.gov (United States)

    Sinclair, M.; Seager, C. H.; McBranch, D.; Heeger, A. J; Baker, G. L.

    1991-01-01

    Along with X{sup (3)}, the magnitude of the optical absorption in the transparent window below the principal absorption edge is an important parameter which will ultimately determine the utility of conjugated polymers in active integrated optical devices. With an absorptance sensitivity of materials. We have used PDS to measure the optical absorption spectra of the conjugated polymers poly(1,4-phenylene-vinylene) (and derivitives) and polydiacetylene-4BCMU in the spectral region from 0.55 eV to 3 eV. Our spectra show that the shape of the absorption edge varies considerably from polymer to polymer, with polydiacetylene-4BCMU having the steepest absorption edge. The minimum absorption coefficients measured varied somewhat with sample age and quality, but were typically in the range 1 cm{sup {minus}1} to 10 cm{sup {minus}1}. In the region below 1 eV, overtones of C-H stretching modes were observed, indicating that further improvements in transparency in this spectral region might be achieved via deuteration of fluorination.

  11. Subgap absorption in conjugated polymers

    Energy Technology Data Exchange (ETDEWEB)

    Sinclair, M.; Seager, C.H. (Sandia National Labs., Albuquerque, NM (USA)); McBranch, D.; Heeger, A.J. (California Univ., Santa Barbara, CA (USA)); Baker, G.L. (Bell Communications Research, Inc., Red Bank, NJ (USA))

    1991-01-01

    Along with X{sup (3)}, the magnitude of the optical absorption in the transparent window below the principal absorption edge is an important parameter which will ultimately determine the utility of conjugated polymers in active integrated optical devices. With an absorptance sensitivity of < 10{sup {minus}5}, Photothermal Deflection Spectroscopy (PDS) is ideal for determining the absorption coefficients of thin films of transparent'' materials. We have used PDS to measure the optical absorption spectra of the conjugated polymers poly(1,4-phenylene-vinylene) (and derivitives) and polydiacetylene-4BCMU in the spectral region from 0.55 eV to 3 eV. Our spectra show that the shape of the absorption edge varies considerably from polymer to polymer, with polydiacetylene-4BCMU having the steepest absorption edge. The minimum absorption coefficients measured varied somewhat with sample age and quality, but were typically in the range 1 cm{sup {minus}1} to 10 cm{sup {minus}1}. In the region below 1 eV, overtones of C-H stretching modes were observed, indicating that further improvements in transparency in this spectral region might be achieved via deuteration of fluorination. 11 refs., 4 figs.

  12. Natural polymers: an overview

    CSIR Research Space (South Africa)

    John, MJ

    2012-08-01

    Full Text Available The scarcity of natural polymers during the world war years led to the development of synthetic polymers like nylon, acrylic, neoprene, styrene-butadiene rubber (SBR) and polyethylene. The increasing popularity of synthetic polymers is partly due...

  13. The minimum yield in channeling

    International Nuclear Information System (INIS)

    Uguzzoni, A.; Gaertner, K.; Lulli, G.; Andersen, J.U.

    2000-01-01

    A first estimate of the minimum yield was obtained from Lindhard's theory, with the assumption of a statistical equilibrium in the transverse phase-space of channeled particles guided by a continuum axial potential. However, computer simulations have shown that this estimate should be corrected by a fairly large factor, C (approximately equal to 2.5), called the Barrett factor. We have shown earlier that the concept of a statistical equilibrium can be applied to understand this result, with the introduction of a constraint in phase-space due to planar channeling of axially channeled particles. Here we present an extended test of these ideas on the basis of computer simulation of the trajectories of 2 MeV α particles in Si. In particular, the gradual trend towards a full statistical equilibrium is studied. We also discuss the introduction of this modification of standard channeling theory into descriptions of the multiple scattering of channeled particles (dechanneling) by a master equation and show that the calculated minimum yields are in very good agreement with the results of a full computer simulation

  14. Minimum Bias Trigger in ATLAS

    International Nuclear Information System (INIS)

    Kwee, Regina

    2010-01-01

    Since the restart of the LHC in November 2009, ATLAS has collected inelastic pp collisions to perform first measurements on charged particle densities. These measurements will help to constrain various models describing phenomenologically soft parton interactions. Understanding the trigger efficiencies for different event types are therefore crucial to minimize any possible bias in the event selection. ATLAS uses two main minimum bias triggers, featuring complementary detector components and trigger levels. While a hardware based first trigger level situated in the forward regions with 2.2 < |η| < 3.8 has been proven to select pp-collisions very efficiently, the Inner Detector based minimum bias trigger uses a random seed on filled bunches and central tracking detectors for the event selection. Both triggers were essential for the analysis of kinematic spectra of charged particles. Their performance and trigger efficiency measurements as well as studies on possible bias sources will be presented. We also highlight the advantage of these triggers for particle correlation analyses. (author)

  15. Polymer dynamics from synthetic polymers to proteins

    Indian Academy of Sciences (India)

    Keywords. Polymer dynamics; reptation; domain dynamics biomolecules. Abstract. Starting from the standard model of polymer motion - the Rouse model - we briefly present some key experimental results on the mesoscopic dynamics of polymer systems. We touch the role of topological confinement as expressed in the ...

  16. Minimum Delay Moving Object Detection

    KAUST Repository

    Lao, Dong

    2017-11-09

    We present a general framework and method for detection of an object in a video based on apparent motion. The object moves relative to background motion at some unknown time in the video, and the goal is to detect and segment the object as soon it moves in an online manner. Due to unreliability of motion between frames, more than two frames are needed to reliably detect the object. Our method is designed to detect the object(s) with minimum delay, i.e., frames after the object moves, constraining the false alarms. Experiments on a new extensive dataset for moving object detection show that our method achieves less delay for all false alarm constraints than existing state-of-the-art.

  17. Approximating the minimum cycle mean

    Directory of Open Access Journals (Sweden)

    Krishnendu Chatterjee

    2013-07-01

    Full Text Available We consider directed graphs where each edge is labeled with an integer weight and study the fundamental algorithmic question of computing the value of a cycle with minimum mean weight. Our contributions are twofold: (1 First we show that the algorithmic question is reducible in O(n^2 time to the problem of a logarithmic number of min-plus matrix multiplications of n-by-n matrices, where n is the number of vertices of the graph. (2 Second, when the weights are nonnegative, we present the first (1 + ε-approximation algorithm for the problem and the running time of our algorithm is ilde(O(n^ω log^3(nW/ε / ε, where O(n^ω is the time required for the classic n-by-n matrix multiplication and W is the maximum value of the weights.

  18. Minimum Delay Moving Object Detection

    KAUST Repository

    Lao, Dong

    2017-01-08

    We present a general framework and method for detection of an object in a video based on apparent motion. The object moves relative to background motion at some unknown time in the video, and the goal is to detect and segment the object as soon it moves in an online manner. Due to unreliability of motion between frames, more than two frames are needed to reliably detect the object. Our method is designed to detect the object(s) with minimum delay, i.e., frames after the object moves, constraining the false alarms. Experiments on a new extensive dataset for moving object detection show that our method achieves less delay for all false alarm constraints than existing state-of-the-art.

  19. Minimum Delay Moving Object Detection

    KAUST Repository

    Lao, Dong; Sundaramoorthi, Ganesh

    2017-01-01

    We present a general framework and method for detection of an object in a video based on apparent motion. The object moves relative to background motion at some unknown time in the video, and the goal is to detect and segment the object as soon it moves in an online manner. Due to unreliability of motion between frames, more than two frames are needed to reliably detect the object. Our method is designed to detect the object(s) with minimum delay, i.e., frames after the object moves, constraining the false alarms. Experiments on a new extensive dataset for moving object detection show that our method achieves less delay for all false alarm constraints than existing state-of-the-art.

  20. Youth minimum wages and youth employment

    NARCIS (Netherlands)

    Marimpi, Maria; Koning, Pierre

    2018-01-01

    This paper performs a cross-country level analysis on the impact of the level of specific youth minimum wages on the labor market performance of young individuals. We use information on the use and level of youth minimum wages, as compared to the level of adult minimum wages as well as to the median

  1. Do Some Workers Have Minimum Wage Careers?

    Science.gov (United States)

    Carrington, William J.; Fallick, Bruce C.

    2001-01-01

    Most workers who begin their careers in minimum-wage jobs eventually gain more experience and move on to higher paying jobs. However, more than 8% of workers spend at least half of their first 10 working years in minimum wage jobs. Those more likely to have minimum wage careers are less educated, minorities, women with young children, and those…

  2. Does the Minimum Wage Affect Welfare Caseloads?

    Science.gov (United States)

    Page, Marianne E.; Spetz, Joanne; Millar, Jane

    2005-01-01

    Although minimum wages are advocated as a policy that will help the poor, few studies have examined their effect on poor families. This paper uses variation in minimum wages across states and over time to estimate the impact of minimum wage legislation on welfare caseloads. We find that the elasticity of the welfare caseload with respect to the…

  3. Minimum income protection in the Netherlands

    NARCIS (Netherlands)

    van Peijpe, T.

    2009-01-01

    This article offers an overview of the Dutch legal system of minimum income protection through collective bargaining, social security, and statutory minimum wages. In addition to collective agreements, the Dutch statutory minimum wage offers income protection to a small number of workers. Its

  4. 21 CFR 177.2210 - Ethylene polymer, chloro-sulfonated.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethylene polymer, chloro-sulfonated. 177.2210... as Components of Articles Intended for Repeated Use § 177.2210 Ethylene polymer, chloro-sulfonated. Ethylene polymer, chlorosulfonated as identified in this section may be safely used as an article or...

  5. 40 CFR 721.9959 - Polyurethane polymer (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Polyurethane polymer (generic). 721... Substances § 721.9959 Polyurethane polymer (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a polyurethane polymer (PMN P-01...

  6. 40 CFR 721.324 - Alkoxylated acrylate polymer (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkoxylated acrylate polymer (generic... Substances § 721.324 Alkoxylated acrylate polymer (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as alkoxylated acrylate polymer...

  7. Shape memory polymers

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, Thomas S.; Bearinger, Jane P.

    2017-08-29

    New shape memory polymer compositions, methods for synthesizing new shape memory polymers, and apparatus comprising an actuator and a shape memory polymer wherein the shape memory polymer comprises at least a portion of the actuator. A shape memory polymer comprising a polymer composition which physically forms a network structure wherein the polymer composition has shape-memory behavior and can be formed into a permanent primary shape, re-formed into a stable secondary shape, and controllably actuated to recover the permanent primary shape. Polymers have optimal aliphatic network structures due to minimization of dangling chains by using monomers that are symmetrical and that have matching amine and hydroxl groups providing polymers and polymer foams with clarity, tight (narrow temperature range) single transitions, and high shape recovery and recovery force that are especially useful for implanting in the human body.

  8. Shape memory polymers

    Science.gov (United States)

    Wilson, Thomas S.; Bearinger, Jane P.

    2015-06-09

    New shape memory polymer compositions, methods for synthesizing new shape memory polymers, and apparatus comprising an actuator and a shape memory polymer wherein the shape memory polymer comprises at least a portion of the actuator. A shape memory polymer comprising a polymer composition which physically forms a network structure wherein the polymer composition has shape-memory behavior and can be formed into a permanent primary shape, re-formed into a stable secondary shape, and controllably actuated to recover the permanent primary shape. Polymers have optimal aliphatic network structures due to minimization of dangling chains by using monomers that are symmetrical and that have matching amine and hydroxyl groups providing polymers and polymer foams with clarity, tight (narrow temperature range) single transitions, and high shape recovery and recovery force that are especially useful for implanting in the human body.

  9. Minimum wage development in the Russian Federation

    OpenAIRE

    Bolsheva, Anna

    2012-01-01

    The aim of this paper is to analyze the effectiveness of the minimum wage policy at the national level in Russia and its impact on living standards in the country. The analysis showed that the national minimum wage in Russia does not serve its original purpose of protecting the lowest wage earners and has no substantial effect on poverty reduction. The national subsistence minimum is too low and cannot be considered an adequate criterion for the setting of the minimum wage. The minimum wage d...

  10. Phase transitions in polymer monolayers

    NARCIS (Netherlands)

    Deschênes, Louise; Lyklema, J.; Danis, Claude; Saint-Germain, François

    2015-01-01

    In this paper we investigate the application of the two-dimensional Clapeyron law to polymer monolayers. This is a largely unexplored area of research. The main problems are (1) establishing if equilibrium is reached and (2) if so, identifying and defining phases as functions of the temperature.

  11. Polymer nanocomposites: polymer and particle dynamics

    KAUST Repository

    Kim, Daniel

    2012-01-01

    Polymer nanocomposites containing nanoparticles smaller than the random coil size of their host polymer chains are known to exhibit unique properties, such as lower viscosity and glass transition temperature relative to the neat polymer melt. It has been hypothesized that these unusual properties result from fast diffusion of the nanostructures in the host polymer, which facilitates polymer chain relaxation by constraint release and other processes. In this study, the effects of addition of sterically stabilized inorganic nanoparticles to entangled cis-1,4-polyisoprene and polydimethylsiloxane on the overall rheology of nanocomposites are discussed. In addition, insights about the relaxation of the host polymer chains and transport properties of nanoparticles in entangled polymer nanocomposites are presented. The nanoparticles are found to act as effective plasticizers for their entangled linear hosts, and below a critical, chemistry and molecular-weight dependent particle volume fraction, lead to reduced viscosity, glass transition temperature, number of entanglements, and polymer relaxation time. We also find that the particle motions in the polymer host are hyperdiffusive and at the nanoparticle length scale, the polymer host acts like a simple, ideal fluid and the composites\\' viscosity rises with increasing particle concentration. © 2012 The Royal Society of Chemistry.

  12. Minimum Delay Moving Object Detection

    KAUST Repository

    Lao, Dong

    2017-05-14

    This thesis presents a general framework and method for detection of an object in a video based on apparent motion. The object moves, at some unknown time, differently than the “background” motion, which can be induced from camera motion. The goal of proposed method is to detect and segment the object as soon it moves in an online manner. Since motion estimation can be unreliable between frames, more than two frames are needed to reliably detect the object. Observing more frames before declaring a detection may lead to a more accurate detection and segmentation, since more motion may be observed leading to a stronger motion cue. However, this leads to greater delay. The proposed method is designed to detect the object(s) with minimum delay, i.e., frames after the object moves, constraining the false alarms, defined as declarations of detection before the object moves or incorrect or inaccurate segmentation at the detection time. Experiments on a new extensive dataset for moving object detection show that our method achieves less delay for all false alarm constraints than existing state-of-the-art.

  13. Characteristics of porous polymer composite columns prepared by radiation cast-polymerization

    International Nuclear Information System (INIS)

    Kumakura, Minoru; Kaetsu, Isao; Asami, Kazuhiro; Suzuki, Shuichi

    1989-01-01

    Porous polymer composite columns having porous structure were prepared by radiation cast-polymerization of hydrophilic monomers at low temperature and their characteristics were studied. The porosity of the polymer increased with decreasing monomer concentration. The elution time of water in the polymer column increased with increasing monomer concentration and with decreasing irradiation temperature. The elution time was dependent on the degree of hydration of the polymer. The polymer with a degree of hydration of 0.2 to 0.4 gave the minimum elution time. The elution time decreased with the addition of porous inorganic substances. (author)

  14. The Minimum Core for Numeracy Audit and Test

    CERN Document Server

    Patmore, Mark

    2008-01-01

    This book supports trainee teachers in the Lifelong Learning Sector in the assessment of their numeracy knowledge. A self-audit section is included to help trainees understand their level of competence and confidence in numeracy and will help them identify any gaps in their knowledge and skills. This is followed by exercises and activities to support and enhance learning. The book covers all the content of the LLUK standards for the minimum core for numeracy. Coverage and assessment of the minimum core have to be embedded in all Certificate and Diploma courses leading to QTLS and ATLS status.

  15. The Minimum Core for Language and Literacy Audit and Test

    CERN Document Server

    Machin, Lynn

    2007-01-01

    This book supports trainee teachers in the Lifelong Learning Sector in the assessment of their literacy knowledge. A self-audit section is included to help trainees understand their level of competence and confidence in literacy and will help them identify any gaps in their knowledge and skills. This is followed by exercises and activities to support and enhance learning. The book covers all the content of the LLUK standards for the minimum core for literacy. Coverage and assessment of the minimum core have to be embedded in all Certificate and Diploma courses leading to QTLS and ATLS status.

  16. Minimum Additive Waste Stabilization (MAWS)

    International Nuclear Information System (INIS)

    1994-02-01

    In the Minimum Additive Waste Stabilization(MAWS) concept, actual waste streams are utilized as additive resources for vitrification, which may contain the basic components (glass formers and fluxes) for making a suitable glass or glassy slag. If too much glass former is present, then the melt viscosity or temperature will be too high for processing; while if there is too much flux, then the durability may suffer. Therefore, there are optimum combinations of these two important classes of constituents depending on the criteria required. The challenge is to combine these resources in such a way that minimizes the use of non-waste additives yet yields a processable and durable final waste form for disposal. The benefit to this approach is that the volume of the final waste form is minimized (waste loading maximized) since little or no additives are used and vitrification itself results in volume reduction through evaporation of water, combustion of organics, and compaction of the solids into a non-porous glass. This implies a significant reduction in disposal costs due to volume reduction alone, and minimizes future risks/costs due to the long term durability and leach resistance of glass. This is accomplished by using integrated systems that are both cost-effective and produce an environmentally sound waste form for disposal. individual component technologies may include: vitrification; thermal destruction; soil washing; gas scrubbing/filtration; and, ion-exchange wastewater treatment. The particular combination of technologies will depend on the waste streams to be treated. At the heart of MAWS is vitrification technology, which incorporates all primary and secondary waste streams into a final, long-term, stabilized glass wasteform. The integrated technology approach, and view of waste streams as resources, is innovative yet practical to cost effectively treat a broad range of DOE mixed and low-level wastes

  17. Strong Selective Adsorption of Polymers.

    Science.gov (United States)

    Ge, Ting; Rubinstein, Michael

    2015-06-09

    A scaling theory is developed for selective adsorption of polymers induced by the strong binding between specific monomers and complementary surface adsorption sites. By "selective" we mean specific attraction between a subset of all monomers, called "sticky", and a subset of surface sites, called "adsorption sites". We demonstrate that, in addition to the expected dependence on the polymer volume fraction ϕ bulk in the bulk solution, selective adsorption strongly depends on the ratio between two characteristic length scales, the root-mean-square distance l between neighboring sticky monomers along the polymer, and the average distance d between neighboring surface adsorption sites. The role of the ratio l / d arises from the fact that a polymer needs to deform to enable the spatial commensurability between its sticky monomers and the surface adsorption sites for selective adsorption. We study strong selective adsorption of both telechelic polymers with two end monomers being sticky and multisticker polymers with many sticky monomers between sticky ends. For telechelic polymers, we identify four adsorption regimes at l / d 1, we expect that the adsorption layer at exponentially low ϕ bulk consists of separated unstretched loops, while as ϕ bulk increases the layer crosses over to a brush of extended loops with a second layer of weakly overlapping tails. For multisticker chains, in the limit of exponentially low ϕ bulk , adsorbed polymers are well separated from each other. As l / d increases, the conformation of an individual polymer changes from a single-end-adsorbed "mushroom" to a random walk of loops. For high ϕ bulk , adsorbed polymers at small l / d are mushrooms that cover all the adsorption sites. At sufficiently large l / d , adsorbed multisticker polymers strongly overlap. We anticipate the formation of a self-similar carpet and with increasing l / d a two-layer structure with a brush of loops covered by a self-similar carpet. As l / d exceeds the

  18. Minimum emittance of three-bend achromats

    International Nuclear Information System (INIS)

    Li Xiaoyu; Xu Gang

    2012-01-01

    The calculation of the minimum emittance of three-bend achromats (TBAs) made by Mathematical software can ignore the actual magnets lattice in the matching condition of dispersion function in phase space. The minimum scaling factors of two kinds of widely used TBA lattices are obtained. Then the relationship between the lengths and the radii of the three dipoles in TBA is obtained and so is the minimum scaling factor, when the TBA lattice achieves its minimum emittance. The procedure of analysis and the results can be widely used in achromats lattices, because the calculation is not restricted by the actual lattice. (authors)

  19. A Pareto-Improving Minimum Wage

    OpenAIRE

    Eliav Danziger; Leif Danziger

    2014-01-01

    This paper shows that a graduated minimum wage, in contrast to a constant minimum wage, can provide a strict Pareto improvement over what can be achieved with an optimal income tax. The reason is that a graduated minimum wage requires high-productivity workers to work more to earn the same income as low-productivity workers, which makes it more difficult for the former to mimic the latter. In effect, a graduated minimum wage allows the low-productivity workers to benefit from second-degree pr...

  20. The minimum wage in the Czech enterprises

    OpenAIRE

    Eva Lajtkepová

    2010-01-01

    Although the statutory minimum wage is not a new category, in the Czech Republic we encounter the definition and regulation of a minimum wage for the first time in the 1990 amendment to Act No. 65/1965 Coll., the Labour Code. The specific amount of the minimum wage and the conditions of its operation were then subsequently determined by government regulation in February 1991. Since that time, the value of minimum wage has been adjusted fifteenth times (the last increase was in January 2007). ...

  1. Microgel polymer composite fibres

    OpenAIRE

    Kehren, Dominic

    2014-01-01

    In this thesis some novel ideas and advancements in the field of polymer composite fibres, specifically microgel-based polymer composite fibres have been achieved. The main task was to investigate and understand the electrospinning process of microgels and polymers and the interplay of parameter influences, in order to fabricate reproducible and continuously homogenous composite fibres. The main aim was to fabricate a composite material which combines the special properties of polymer fibres ...

  2. Diketopyrrolopyrrole Polymers for Organic Solar Cells.

    Science.gov (United States)

    Li, Weiwei; Hendriks, Koen H; Wienk, Martijn M; Janssen, René A J

    2016-01-19

    Conjugated polymers have been extensively studied for application in organic solar cells. In designing new polymers, particular attention has been given to tuning the absorption spectrum, molecular energy levels, crystallinity, and charge carrier mobility to enhance performance. As a result, the power conversion efficiencies (PCEs) of solar cells based on conjugated polymers as electron donor and fullerene derivatives as electron acceptor have exceeded 10% in single-junction and 11% in multijunction devices. Despite these efforts, it is notoriously difficult to establish thorough structure-property relationships that will be required to further optimize existing high-performance polymers to their intrinsic limits. In this Account, we highlight progress on the development and our understanding of diketopyrrolopyrrole (DPP) based conjugated polymers for polymer solar cells. The DPP moiety is strongly electron withdrawing and its polar nature enhances the tendency of DPP-based polymers to crystallize. As a result, DPP-based conjugated polymers often exhibit an advantageously broad and tunable optical absorption, up to 1000 nm, and high mobilities for holes and electrons, which can result in high photocurrents and good fill factors in solar cells. Here we focus on the structural modifications applied to DPP polymers and rationalize and explain the relationships between chemical structure and organic photovoltaic performance. The DPP polymers can be tuned via their aromatic substituents, their alkyl side chains, and the nature of the π-conjugated segment linking the units along the polymer chain. We show that these building blocks work together in determining the molecular conformation, the optical properties, the charge carrier mobility, and the solubility of the polymer. We identify the latter as a decisive parameter for DPP-based organic solar cells because it regulates the diameter of the semicrystalline DPP polymer fibers that form in the photovoltaic blends with

  3. The effects of gamma-irradiation on additives in food-contact polymers

    Science.gov (United States)

    Smith, Christine

    A range of antioxidants (BHT, Irganox 1010, 1076, 1330 and Irgafos 168) were incorporated into polymers (polyethylene, polypropylene, polystyrene and polyvinyl chloride) and subjected to increasing doses of gamma-irradiation (1,5,10,20,25,35 and 50 kGy) from a cobalt-60 source.The amount of extractable antioxidant from the stabilised polymers was determined chromatographically and a gradual diminution in the total extractable levels of each antioxidant was observed as irradiation progressed, the extent depending on the nature of both the antioxidant and the polymer 2,6-Di-t-butyl-1,4-benzoquinone was shown to be an extractable degradation product, arising from the effects of gamma-irradiation on the phenolic antioxidants. The extractable degradation product arising from the phosphite antioxidant, Irgafos 168, was identified as tris(2,4-di-t-butylphenyl)phosphate. It was demonstrated using 14C-labelled Irganox 1076 that degradation products formed during gamma-irradiation are becoming covalently bound to the polymer, as a result of radical coupling processes. There is a pronounced increase in the extent of covalent binding from 0.4% before irradiation to a minimum of 12.4% after an exposure to 50 kGy. Evidence has also been presented of covalent binding of the degradation product of Irgafos 168 to the polypropylene matrix, via polymeric radicals formed during irradiation. Finally, the effects of gamma-irradiation on the extent of migration of antioxidants from polyolefins into food simulants was studied. It was found that irradiation leads to a decrease in the extent to which hindered phenolic antioxidants migrate from polyolefins into fatty media, consistent with the reduction in extractable antioxidant levels and the increase in the extent of antioxidant-polymer binding.

  4. Initial Drug Dissolution from Amorphous Solid Dispersions Controlled by Polymer Dissolution and Drug-Polymer Interaction.

    Science.gov (United States)

    Chen, Yuejie; Wang, Shujing; Wang, Shan; Liu, Chengyu; Su, Ching; Hageman, Michael; Hussain, Munir; Haskell, Roy; Stefanski, Kevin; Qian, Feng

    2016-10-01

    To identify the key formulation factors controlling the initial drug and polymer dissolution rates from an amorphous solid dispersion (ASD). Ketoconazole (KTZ) ASDs using PVP, PVP-VA, HMPC, or HPMC-AS as polymeric matrix were prepared. For each drug-polymer system, two types of formulations with the same composition were prepared: 1. Spray dried dispersion (SDD) that is homogenous at molecular level, 2. Physical blend of SDD (80% drug loading) and pure polymer (SDD-PB) that is homogenous only at powder level. Flory-Huggins interaction parameters (χ) between KTZ and the four polymers were obtained by Flory-Huggins model fitting. Solution (13)C NMR and FT-IR were conducted to investigate the specific drug-polymer interaction in the solution and solid state, respectively. Intrinsic dissolution of both the drug and the polymer from ASDs were studied using a Higuchi style intrinsic dissolution apparatus. PXRD and confocal Raman microscopy were used to confirm the absence of drug crystallinity on the tablet surface before and after dissolution study. In solid state, KTZ is completely miscible with PVP, PVP-VA, or HPMC-AS, demonstrated by the negative χ values of -0.36, -0.46, -1.68, respectively; while is poorly miscible with HPMC shown by a positive χ value of 0.23. According to solution (13)C NMR and FT-IR studies, KTZ interacts with HPMC-AS strongly through H-bonding and dipole induced interaction; with PVPs and PVP-VA moderately through dipole-induced interactions; and with HPMC weakly without detectable attractive interaction. Furthermore, the "apparent" strength of drug-polymer interaction, measured by the extent of peak shift on NMR or FT-IR spectra, increases with the increasing number of interacting drug-polymer pairs. For ASDs with the presence of considerable drug-polymer interactions, such as KTZ/PVPs, KTZ/PVP-VA, or KTZ /HPMC-AS systems, drug released at the same rate as the polymer when intimate drug-polymer mixing was ensured (i.e., the SDD systems

  5. Stochastic variational approach to minimum uncertainty states

    Energy Technology Data Exchange (ETDEWEB)

    Illuminati, F.; Viola, L. [Dipartimento di Fisica, Padova Univ. (Italy)

    1995-05-21

    We introduce a new variational characterization of Gaussian diffusion processes as minimum uncertainty states. We then define a variational method constrained by kinematics of diffusions and Schroedinger dynamics to seek states of local minimum uncertainty for general non-harmonic potentials. (author)

  6. Zero forcing parameters and minimum rank problems

    NARCIS (Netherlands)

    Barioli, F.; Barrett, W.; Fallat, S.M.; Hall, H.T.; Hogben, L.; Shader, B.L.; Driessche, van den P.; Holst, van der H.

    2010-01-01

    The zero forcing number Z(G), which is the minimum number of vertices in a zero forcing set of a graph G, is used to study the maximum nullity/minimum rank of the family of symmetric matrices described by G. It is shown that for a connected graph of order at least two, no vertex is in every zero

  7. 30 CFR 281.30 - Minimum royalty.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Minimum royalty. 281.30 Section 281.30 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR OFFSHORE LEASING OF MINERALS OTHER THAN OIL, GAS, AND SULPHUR IN THE OUTER CONTINENTAL SHELF Financial Considerations § 281.30 Minimum royalty...

  8. New Minimum Wage Research: A Symposium.

    Science.gov (United States)

    Ehrenberg, Ronald G.; And Others

    1992-01-01

    Includes "Introduction" (Ehrenberg); "Effect of the Minimum Wage [MW] on the Fast-Food Industry" (Katz, Krueger); "Using Regional Variation in Wages to Measure Effects of the Federal MW" (Card); "Do MWs Reduce Employment?" (Card); "Employment Effects of Minimum and Subminimum Wages" (Neumark,…

  9. Minimum Wage Effects in the Longer Run

    Science.gov (United States)

    Neumark, David; Nizalova, Olena

    2007-01-01

    Exposure to minimum wages at young ages could lead to adverse longer-run effects via decreased labor market experience and tenure, and diminished education and training, while beneficial longer-run effects could arise if minimum wages increase skill acquisition. Evidence suggests that as individuals reach their late 20s, they earn less the longer…

  10. Thermosetting Phthalocyanine Polymers

    Science.gov (United States)

    Fohlen, G.; Parker, J.; Achar, B.

    1985-01-01

    Group of phthalocyanine polymers resist thermal degradation. Polymers expected semiconducting. Principal applications probably in molded or laminated parts that have to withstand high temperatures. Polymers made from either of two classes of monomer: Bisphthalonitriles with imide linkages or Bisphthalonitriles with ester-imide linkages.

  11. based gel polymer electrolytes

    Indian Academy of Sciences (India)

    (PVdF) as a host polymer, lithium perchlorate (LiClO4), lithium triflate ... TG/DTA studies showed the thermal stability of the polymer electrolytes. .... are observed while comparing pure XRD spectra with .... batteries as its operating temperature is normally in the .... chain ion movements and the conductivity of the polymer.

  12. Aerogel / Polymer Composite Materials

    Science.gov (United States)

    Williams, Martha K. (Inventor); Smith, Trent M. (Inventor); Fesmire, James E. (Inventor); Roberson, Luke B. (Inventor); Clayton, LaNetra M. (Inventor)

    2017-01-01

    The invention provides new composite materials containing aerogels blended with thermoplastic polymer materials at a weight ratio of aerogel to thermoplastic polymer of less than 20:100. The composite materials have improved thermal insulation ability. The composite materials also have better flexibility and less brittleness at low temperatures than the parent thermoplastic polymer materials.

  13. Miscibility Evaluation Of The Next Generation Solvent With Polymers Currently Used At DWPF, MCU, And Saltstone

    Energy Technology Data Exchange (ETDEWEB)

    Fondeur, F. F.

    2013-04-17

    The Office of Waste Processing, within the Office of Technology Innovation and Development, funded the development of an enhanced Caustic-Side Solvent Extraction (CSSX) solvent for deployment at the Savannah River Site for removal of cesium from High Level Waste. This effort lead to the development of the Next Generation Solvent (NGS) with Tris (3,7-dimethyl octyl) guanidine (TiDG). The first deployment target for the NGS solvent is within the Modular CSSX Unit (MCU). Deployment of a new chemical within an existing facility requires verification that the new chemical components are compatible with the installed equipment. In the instance of a new organic solvent, the primary focus is on compatibility of the solvent with organic polymers used in the affected facility. This report provides the calculated data from exposing these polymers to the Next Generation Solvent. An assessment of the dimensional stability of polymers known to be used or present in the MCU, Defense Waste Processing Facility (DWPF), and Saltstone facilities that will be exposed to the NGS showed that TiDG could selectively affect the elastomers and some thermoplastics to varying extents, but the typical use of these polymers in a confined geometry will likely prevent the NGS from impacting component performance. The polymers identified as of primary concern include Grafoil® (flexible graphite), Tefzel®, Isolast®, ethylene-propylene-diene monomer (EPDM) rubber, nitrile-butadiene rubber (NBR), styrene-butadiene rubber (SBR), ultra high molecular weight polyethylene (UHMWPE), and fluorocarbon rubber (FKM). Certain polymers like NBR and EPDM were found to interact mildly with NGS but their calculated swelling and the confined geometry will impede interaction with NGS. In addition, it was found that Vellumoid (cellulose fibers-reinforced glycerin and protein) may leach protein and Polyvinyl Chloride (PVC) may leach plasticizer (such as Bis-Ethylhexyl-Phthalates) into the NGS solvent. Either case

  14. Polymers in nuclear environment - long term behaviour

    International Nuclear Information System (INIS)

    Audouin, Laurent; Colin, Xavier; Fayolle, Bruno; Richaud, Emmanuel

    2012-01-01

    This bibliographical note presents a book which addresses original theoretical tools which are required for the prediction of polymer life time in a nuclear environment, and notably the kinetic modelling of low dose rate radiation-induced oxidation and the consequences of irradiation on thermo-mechanical properties. The authors discuss the anaerobic radiochemical ageing, the general aspects of radio-oxidation, the radio-thermo-oxidation, and the effects of radiochemical ageing on mechanical properties of industrial polymers. They identify research fields for the radiochemical ageing of polymers

  15. Flexible ITO-Free Polymer Solar Cells

    DEFF Research Database (Denmark)

    Angmo, Dechan; Krebs, Frederik C

    2013-01-01

    Indium tin oxide (ITO) is the material-of-choice for transparent conductors in any optoelectronic application. However, scarce resources of indium and high market demand of ITO have created large price fluctuations and future supply concerns. In polymer solar cells (PSCs), ITO is the single......-cost alternatives to ITO suitable for use in PSCs. These alternatives belong to four material groups: polymers; metal and polymer composites; metal nanowires and ultra-thin metal films; and carbon nanotubes and graphene. We further present the progress of employing these alternatives in PSCs and identify future...

  16. Electroluminescence of Multicomponent Conjugated Polymers. 1. Roles of Polymer/Polymer Interfaces in Emission Enhancement and Voltage-Tunable Multicolor Emission in Semiconducting Polymer/Polymer Heterojunctions

    National Research Council Canada - National Science Library

    Zhang, Xuejun, Ph.D

    1999-01-01

    Effects of the electronic structure of polymer/polymer interfaces on the electroluminescence efficiency and tunable multicolor emission of polymer heterojunction light-emitting diodes were explored...

  17. Nanoporous polymer electrolyte

    Science.gov (United States)

    Elliott, Brian [Wheat Ridge, CO; Nguyen, Vinh [Wheat Ridge, CO

    2012-04-24

    A nanoporous polymer electrolyte and methods for making the polymer electrolyte are disclosed. The polymer electrolyte comprises a crosslinked self-assembly of a polymerizable salt surfactant, wherein the crosslinked self-assembly includes nanopores and wherein the crosslinked self-assembly has a conductivity of at least 1.0.times.10.sup.-6 S/cm at 25.degree. C. The method of making a polymer electrolyte comprises providing a polymerizable salt surfactant. The method further comprises crosslinking the polymerizable salt surfactant to form a nanoporous polymer electrolyte.

  18. Polymer friction Molecular Dynamics

    DEFF Research Database (Denmark)

    Sivebæk, Ion Marius; Samoilov, Vladimir N.; Persson, Bo N. J.

    We present molecular dynamics friction calculations for confined hydrocarbon solids with molecular lengths from 20 to 1400 carbon atoms. Two cases are considered: a) polymer sliding against a hard substrate, and b) polymer sliding on polymer. In the first setup the shear stresses are relatively...... independent of molecular length. For polymer sliding on polymer the friction is significantly larger, and dependent on the molecular chain length. In both cases, the shear stresses are proportional to the squeezing pressure and finite at zero load, indicating an adhesional contribution to the friction force....

  19. Biostable glucose permeable polymer

    DEFF Research Database (Denmark)

    2017-01-01

    A new biostable glucose permeable polymer has been developed which is useful, for example, in implantable glucose sensors. This biostable glucose permeable polymer has a number of advantageous characteristics and, for example, does not undergo hydrolytic cleavage and degradation, thereby providing...... a composition that facilitates long term sensor stability in vivo. The versatile characteristics of this polymer allow it to be used in a variety of contexts, for example to form the body of an implantable glucose sensor. The invention includes the polymer composition, sensor systems formed from this polymer...

  20. Fluorination of polymers

    International Nuclear Information System (INIS)

    Du Toit, F.J.

    1991-01-01

    Polyethylene and polypropylene were reacted with elemental fluorine under carefully controlled conditions to produce fluorocarbon polymers. Fluorination of polymer films resulted in fluorination of only the outer surfaces of the films, while the reaction of elemental fluorine with powdered hydrocarbon polymers produced perfluorocarbon polymers. Existing and newly developed techniques were used to characterize the fluorinated polymers. It was shown that the degree of fluorination was influenced by the surface area of the hydrocarbon material, the concentration, of the fluorine gas, and the time and temperature of fluorination. A fluidized-bed reactor used for the fluorination of polymer powders effectively increased the reaction rate. The surface tension and the oxygen permeability of the fluorinated polymers were studied. The surface tension of hydrocarbon polymers was not influenced by different solvents, but the surface tension of fluorinated polymers was affected by the type of solvent that was used. There were indications that the surface tension was affected by oxygen introduced into the polymer surface during fluorination. Fluorination lowered the permeability of oxygen through hydrocarbon polymers. 55 refs., 51 figs., 26 tabs

  1. Advanced polymers in medicine

    CERN Document Server

    Puoci, Francesco

    2014-01-01

    The book provides an up-to-date overview of the diverse medical applications of advanced polymers. The book opens by presenting important background information on polymer chemistry and physicochemical characterization of polymers. This serves as essential scientific support for the subsequent chapters, each of which is devoted to the applications of polymers in a particular medical specialty. The coverage is broad, encompassing orthopedics, ophthalmology, tissue engineering, surgery, dentistry, oncology, drug delivery, nephrology, wound dressing and healing, and cardiology. The development of polymers that enhance the biocompatibility of blood-contacting medical devices and the incorporation of polymers within biosensors are also addressed. This book is an excellent guide to the recent advances in polymeric biomaterials and bridges the gap between the research literature and standard textbooks on the applications of polymers in medicine.

  2. Antiviral Polymer Therapeutics

    DEFF Research Database (Denmark)

    Smith, Anton Allen Abbotsford

    2014-01-01

    polymerized in a controlled manner with carrier monomers of historically proven biocompatible polymers. The carrier polymers, the loading of ribavirin as well as the size of the polymer were varied systematically with the aid of an automated synthesis platform. These polymers were tested in a cellular assay...... of reversible-addition-fragmentation chain transfer polymerization, which not only controls the size of polymer, but also allows the introduction of a terminal amine on the polymer which can be used for further conjugation. This has allowed for not only fluorescent labeling of the polymer, but also protein...... is mediated through specific transporters, it is thought that the accumulation can be alleviated through the attachment of ribavirin to a macromolecule. To this end, ribavirin was enzymatically modified into a monomer compatible with controlled polymerization techniques. The ribavirin monomers were...

  3. Molecular dynamics modeling of polymer flammability

    International Nuclear Information System (INIS)

    Nyden, M.R.; Brown, J.E.; Lomakin, S.M.

    1992-01-01

    Molecular dynamic simulations were used to identify factors which promote char formation during the thermal degradation of polymers. Computer movies based on these simulations, indicate that cross-linked model polymers tend to undergo further cross-linking when burned, eventually forming a high molecular weight, thermally stable char. This paper reports that the prediction was confirmed by char yield measurements made on γ and e - -irradiated polyethylene and chemically cross-linked poly(methyl methacrylate)

  4. Experimental Polymer Mechanochemistry and its Interpretational Frameworks.

    Science.gov (United States)

    Akbulatov, Sergey; Boulatov, Roman

    2017-06-02

    Polymer mechanochemistry is an emerging field at the interface of chemistry, materials science, physics and engineering. It aims at understanding and exploiting unique reactivities of polymer chains confined to highly non-equilibrium stretched geometries by interactions with their surroundings. Macromolecular chains or their segments become stretched in bulk polymers under mechanical loads or when polymer solutions are sonicated or flow rapidly through abrupt contractions. An increasing amount of empirical data suggests that mechanochemical phenomena are widespread wherever polymers are used. In the past decade, empirical mechanochemistry has progressed enormously, from studying fragmentations of commodity polymers by simple backbone homolysis to demonstrations of self-strengthening and stress-reporting materials and mechanochemical cascades using purposefully designed monomers. This progress has not yet been matched by the development of conceptual frameworks within which to rationalize, systematize and generalize empirical mechanochemical observations. As a result, mechanistic and/or quantitative understanding of mechanochemical phenomena remains, with few exceptions, tentative. In this review we aim at systematizing reported macroscopic manifestations of polymer mechanochemistry, and critically assessing the interpretational framework that underlies their molecular rationalizations from a physical chemist's perspective. We propose a hierarchy of mechanochemical phenomena which may guide the development of multiscale models of mechanochemical reactivity to match the breadth and utility of the Eyring equation of chemical kinetics. We discuss the limitations of the approaches to quantifying and validating mechanochemical reactivity, with particular focus on sonicated polymer solutions, in order to identify outstanding questions that need to be solved for polymer mechanochemistry to become a rigorous, quantitative field. We conclude by proposing 7 problems whose

  5. Polymer reaction engineering, an integrated approach

    NARCIS (Netherlands)

    Meyer, T.; Keurentjes, J.T.F.; Meyer, T.; Keurentjes, J.T.F.

    2005-01-01

    Summary This chapter contains sections titled: Polymer Materials A Short History of Polymer Reaction Engineering The Position of Polymer Reaction Engineering Toward Integrated Polymer Reaction Engineering The Disciplines in Polymer Reaction Engineering The Future: Product-inspired Polymer Reaction

  6. Interaction of energetic particles with polymer surfaces: surface morphology development and sputtered polymer-fragment ion analysis

    International Nuclear Information System (INIS)

    Michael, R.S.

    1987-01-01

    The core of this thesis is based on a series of papers that have been published or will soon be published in which the various processes taking place in the energetic particle-polymer surface interaction scene is investigated. Results presented show different developments on polymer surfaces when compared to the vast experimental data on energetic particle-metal surface interactions. The surface morphology development depends on the physical characteristics of the polymer. Sputtering yields of fluoropolymers were several orders higher than the sputtering yields of aliphatic and aromatic polymers. Depending on the chemical nature of the polymer, the surface morphology development was dependent upon the extent of radiation-damage accumulation. Fast Atom Bombardment Mass Spectrometry at low and high resolution was applied to the characterization of sputtered polymer fragment ions. Fragment ions and their intensities were used to identify polymer samples, observe radiation damage accumulation and probe polymer-polymer interface of a polymer-polymer sandwich structure. A model was proposed which attempts to explain the nature of processes involved in the energetic particle-polymer surface interaction region

  7. Operating pumps on minimum flow

    International Nuclear Information System (INIS)

    Casada, D.A.; Li, Y.C.

    1992-01-01

    The Nuclear Regulatory Commission (NRC) staff issued Information Notice (IN) 87-59 to alert all licensees to two miniflow design concerns identified by Westinghouse. The first potential problem discussed in this IN involves parallel pump operation. If the head/capacity curve of one of the parallel pumps is greater than the other, the weaker pump may be dead-headed when the pumps are operating at low-flow conditions. The other problem related to potential pump damage as a result of hydraulic instability during low-flow operation. In NRC Bulletin 88-04, dated May 5, 1988, the staff requested all licensees to investigate and correct, as applicable, the two miniflow design concerns. The staff also developed a Temporary Instruction, Tl 2515/105, dated January 29, 1990 to inspect for the adequacy of licensee response and follow-up actions to NRC Bulletin 88-04. Oak Ridge National Laboratory has reviewed utility responses to Bulletin 88-04 under auspices of the NRC's Nuclear Plant Aging Research Program, and participated in several NRC inspections. Examples of actions that have been taken, an assessment of the overall industry response, and resultant conclusions and recommendations are presented

  8. ``Smart'' Surfaces of Polymer Brushes

    Science.gov (United States)

    Wang, Qiang; Meng, Dong

    2009-03-01

    ``Smart'' surfaces, also known as stimuli-responsive surfaces, can change their properties (e.g., wettability, adhesion, friction, elasticity, and biocompatibility) in response to external stimuli (e.g., temperature, pressure, light, solvent selectivity, ionic strength, type of salt, pH, applied electric field, etc.). In this work, we use numerical self-consistent field calculations to study in detail the structure and stimuli- responses of various polymer brushes, including (1) the thermo- response of PNIPAM brushes in water, (2) solvent-response of uncharged diblock copolymer brushes, and (3) the stimuli- response of charged two-component polymer brushes (including both the binary A/B brushes and diblock copolymer A-B brushes) to ionic strength, pH, and applied electric field. Among the many design parameters (e.g., chain lengths, grafting densities, A-B incompatibility, degree of ionization of charged polymers, etc.) we identify those that strongly affect the surface switchability. Such knowledge is useful to the experimental design of these smart polymer brushes for their applications.

  9. Minimum emittance in TBA and MBA lattices

    Science.gov (United States)

    Xu, Gang; Peng, Yue-Mei

    2015-03-01

    For reaching a small emittance in a modern light source, triple bend achromats (TBA), theoretical minimum emittance (TME) and even multiple bend achromats (MBA) have been considered. This paper derived the necessary condition for achieving minimum emittance in TBA and MBA theoretically, where the bending angle of inner dipoles has a factor of 31/3 bigger than that of the outer dipoles. Here, we also calculated the conditions attaining the minimum emittance of TBA related to phase advance in some special cases with a pure mathematics method. These results may give some directions on lattice design.

  10. Minimum emittance in TBA and MBA lattices

    International Nuclear Information System (INIS)

    Xu Gang; Peng Yuemei

    2015-01-01

    For reaching a small emittance in a modern light source, triple bend achromats (TBA), theoretical minimum emittance (TME) and even multiple bend achromats (MBA) have been considered. This paper derived the necessary condition for achieving minimum emittance in TBA and MBA theoretically, where the bending angle of inner dipoles has a factor of 3 1/3 bigger than that of the outer dipoles. Here, we also calculated the conditions attaining the minimum emittance of TBA related to phase advance in some special cases with a pure mathematics method. These results may give some directions on lattice design. (authors)

  11. Who Benefits from a Minimum Wage Increase?

    OpenAIRE

    John W. Lopresti; Kevin J. Mumford

    2015-01-01

    This paper addresses the question of how a minimum wage increase affects the wages of low-wage workers. Most studies assume that there is a simple mechanical increase in the wage for workers earning a wage between the old and the new minimum wage, with some studies allowing for spillovers to workers with wages just above this range. Rather than assume that the wages of these workers would have remained constant, this paper estimates how a minimum wage increase impacts a low-wage worker's wage...

  12. Wage inequality, minimum wage effects and spillovers

    OpenAIRE

    Stewart, Mark B.

    2011-01-01

    This paper investigates possible spillover effects of the UK minimum wage. The halt in the growth in inequality in the lower half of the wage distribution (as measured by the 50:10 percentile ratio) since the mid-1990s, in contrast to the continued inequality growth in the upper half of the distribution, suggests the possibility of a minimum wage effect and spillover effects on wages above the minimum. This paper analyses individual wage changes, using both a difference-in-differences estimat...

  13. Star-Branched Polymers (Star Polymers)

    KAUST Repository

    Hirao, Akira; Hayashi, Mayumi; Ito, Shotaro; Goseki, Raita; Higashihara, Tomoya; Hadjichristidis, Nikolaos

    2015-01-01

    The synthesis of well-defined regular and asymmetric mixed arm (hereinafter miktoarm) star-branched polymers by the living anionic polymerization is reviewed in this chapter. In particular, much attention is being devoted to the synthetic

  14. Polymer dynamics from synthetic polymers to proteins

    Indian Academy of Sciences (India)

    Abstract. Starting from the standard model of polymer motion – the Rouse model – .... reptation and the escape processes (creep motion) from the tube. .... scattering curves from an arrangement of small mesoscopic spheres also allows a.

  15. How unprecedented a solar minimum was it?

    Science.gov (United States)

    Russell, C T; Jian, L K; Luhmann, J G

    2013-05-01

    The end of the last solar cycle was at least 3 years late, and to date, the new solar cycle has seen mainly weaker activity since the onset of the rising phase toward the new solar maximum. The newspapers now even report when auroras are seen in Norway. This paper is an update of our review paper written during the deepest part of the last solar minimum [1]. We update the records of solar activity and its consequent effects on the interplanetary fields and solar wind density. The arrival of solar minimum allows us to use two techniques that predict sunspot maximum from readings obtained at solar minimum. It is clear that the Sun is still behaving strangely compared to the last few solar minima even though we are well beyond the minimum phase of the cycle 23-24 transition.

  16. Impact of the Minimum Wage on Compression.

    Science.gov (United States)

    Wolfe, Michael N.; Candland, Charles W.

    1979-01-01

    Assesses the impact of increases in the minimum wage on salary schedules, provides guidelines for creating a philosophy to deal with the impact, and outlines options and presents recommendations. (IRT)

  17. Quantitative Research on the Minimum Wage

    Science.gov (United States)

    Goldfarb, Robert S.

    1975-01-01

    The article reviews recent research examining the impact of minimum wage requirements on the size and distribution of teenage employment and earnings. The studies measure income distribution, employment levels and effect on unemployment. (MW)

  18. Determining minimum lubrication film for machine parts

    Science.gov (United States)

    Hamrock, B. J.; Dowson, D.

    1978-01-01

    Formula predicts minimum film thickness required for fully-flooded ball bearings, gears, and cams. Formula is result of study to determine complete theoretical solution of isothermal elasto-hydrodynamic lubrication of fully-flooded elliptical contacts.

  19. Long Term Care Minimum Data Set (MDS)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Long-Term Care Minimum Data Set (MDS) is a standardized, primary screening and assessment tool of health status that forms the foundation of the comprehensive...

  20. The SME gauge sector with minimum length

    Energy Technology Data Exchange (ETDEWEB)

    Belich, H.; Louzada, H.L.C. [Universidade Federal do Espirito Santo, Departamento de Fisica e Quimica, Vitoria, ES (Brazil)

    2017-12-15

    We study the gauge sector of the Standard Model Extension (SME) with the Lorentz covariant deformed Heisenberg algebra associated to the minimum length. In order to find and estimate corrections, we clarify whether the violation of Lorentz symmetry and the existence of a minimum length are independent phenomena or are, in some way, related. With this goal, we analyze the dispersion relations of this theory. (orig.)

  1. The SME gauge sector with minimum length

    Science.gov (United States)

    Belich, H.; Louzada, H. L. C.

    2017-12-01

    We study the gauge sector of the Standard Model Extension (SME) with the Lorentz covariant deformed Heisenberg algebra associated to the minimum length. In order to find and estimate corrections, we clarify whether the violation of Lorentz symmetry and the existence of a minimum length are independent phenomena or are, in some way, related. With this goal, we analyze the dispersion relations of this theory.

  2. Star-Branched Polymers (Star Polymers)

    KAUST Repository

    Hirao, Akira

    2015-09-01

    The synthesis of well-defined regular and asymmetric mixed arm (hereinafter miktoarm) star-branched polymers by the living anionic polymerization is reviewed in this chapter. In particular, much attention is being devoted to the synthetic development of miktoarm star polymers since 2000. At the present time, the almost all types of multiarmed and multicomponent miktoarm star polymers have become feasible by using recently developed iterative strategy. For example, the following well-defined stars have been successfully synthesized: 3-arm ABC, 4-arm ABCD, 5-arm ABCDE, 6-arm ABCDEF, 7-arm ABCDEFG, 6-arm ABC, 9-arm ABC, 12-arm ABC, 13-arm ABCD, 9-arm AB, 17-arm AB, 33-arm AB, 7-arm ABC, 15-arm ABCD, and 31-arm ABCDE miktoarm star polymers, most of which are quite new and difficult to synthesize by the end of the 1990s. Several new specialty functional star polymers composed of vinyl polymer segments and rigid rodlike poly(acetylene) arms, helical polypeptide, or helical poly(hexyl isocyanate) arms are introduced.

  3. Physico-chemistry characterization of sulfonated polyacrylamide polymers for use in polymer flooding

    Energy Technology Data Exchange (ETDEWEB)

    Rashidi, Masoud

    2010-07-01

    Hydrolyzed polyacrylamide polymer (HPAM) as a feasible and effective viscosifier has been fully studied and used for polymer flooding processes in several oil field, e.g. Daqing oil field. It has been shown that Hydrolyzed polyacrylamide polymers (HPAM) may be a good choice for high temperature condition with no oxygen and no divalent ions presence. At high temperature and high salinity conditions, polymer may precipitates and loss their viscosyfing properties. Also adsorption and retention of polymer in porous medium may change rheological properties of polymers. Thus, the viscosyfing property of polymers is influenced by several important parameters, e.g. salinity, hardness, temperature, adsorption, retention, polymer structure, and etc. By replacing some of carboxylate group of HPAM with another monomer, e.g. sodium salt of acrylic acid and 2-acrylamido-2-methylpropane sulfonic acid (AMPS), effect of high salinity/hardness and temperature seems to be reduced specially for the samples with higher percentage of AMPS co-monomer. The ultimate aim of this work is to develop an understanding of the sulfonated polyacrylamide copolymers with a range of different sulfonation and molecular weight at high salinity and high temperature conditions. Most of the work in this thesis deals with viscosity and adsorption/retention measurements of the sulfonated copolymers and HPAM. The factors which may affect the viscosity of the polymers and have been identified in this work as most likely influencing also adsorption and retention of the polymers are shear rate, polymer concentration, sulfonation degree, molecular weight, NaCl concentration, divalent ion concentration, and temperature. (Author)

  4. Artificially Engineered Protein Polymers.

    Science.gov (United States)

    Yang, Yun Jung; Holmberg, Angela L; Olsen, Bradley D

    2017-06-07

    Modern polymer science increasingly requires precise control over macromolecular structure and properties for engineering advanced materials and biomedical systems. The application of biological processes to design and synthesize artificial protein polymers offers a means for furthering macromolecular tunability, enabling polymers with dispersities of ∼1.0 and monomer-level sequence control. Taking inspiration from materials evolved in nature, scientists have created modular building blocks with simplified monomer sequences that replicate the function of natural systems. The corresponding protein engineering toolbox has enabled the systematic development of complex functional polymeric materials across areas as diverse as adhesives, responsive polymers, and medical materials. This review discusses the natural proteins that have inspired the development of key building blocks for protein polymer engineering and the function of these elements in material design. The prospects and progress for scalable commercialization of protein polymers are reviewed, discussing both technology needs and opportunities.

  5. Bounds for the minimum step number of knots confined to slabs in the simple cubic lattice

    International Nuclear Information System (INIS)

    Ishihara, K; Shimokawa, K; Scharein, R; Arsuaga, J; Vazquez, M; Diao, Y

    2012-01-01

    Volume confinement is a key determinant of the topology and geometry of a polymer. However, the direct relationship between the two is not fully understood. For instance, recent experimental studies have constructed P4 cosmids, i.e. P4 bacteriophages whose genome sequence and length have been artificially engineered and have shown that upon extraction their DNA knot distribution differs from that of wild-type bacteriophage P4. In particular, it was observed that the complexity of the knots decreases sharply with the length of the packed genome. This problem is the motivation of this paper. Here, a polymer is modeled as a self-avoiding polygon on the simple cubic lattice and the confining condition is such that the polygon is bounded between two parallel planes (i.e. bounded within a slab). We estimate the minimum length required for such a polygon to realize a knot type. Our numerical simulations show that in order to realize a prime knot (with up to ten crossings) in a 1-slab (i.e. a slab of height 1), one needs a polygon of length strictly longer than the minimum length needed to realize the same knot when there is no confining condition. In the case of the trefoil knot, we can in fact establish this result analytically by proving that the minimum length required to tie a trefoil in the 1-slab is 26, which is greater than 24, the known minimum length required to tie a trefoil without a confinement condition. Additionally, we find that in the 1-slab not all geometrical realizations of a given knot type are equivalent under BFACF moves. This suggests that in certain confined volumes, knowing the topology of a polymer is not enough to describe all its states. (paper)

  6. Internally plasticised cellulose polymers

    International Nuclear Information System (INIS)

    Burnup, M.; Hayes, G.F.; Fydelor, P.J.

    1981-01-01

    Plasticised cellulose polymers comprise base polymer having a chain of β-anhydroglucose units joined by ether linkages, with at least one of said units carrying at least one chemically unreactive side chain derived from an allylic monomer or a vinyl substituted derivative of ferrocene. The side chains are normally formed by radiation grafting. These internally plasticised celluloses are useful in particular as inhibitor coatings for rocket motor propellants and in general wherever cellulose polymers are employed. (author)

  7. Characterisation of polymers, 1

    CERN Document Server

    Crompton, Roy

    2008-01-01

    This essential guide to Polymer Characterisation is a complete compendium of methodologies that have evolved for the determination of the chemical composition of polymers. This 478-page book gives an up-to-date and thorough exposition of the state-of-the-art theories and availability of instrumentation needed to effect chemical and physical analysis of polymers. This is supported by approximately 1200 references. Volume 1 covers the methodology used for the determination of metals, non-metals and organic functional groups in polymers, and for the determination of the ratio in which different m

  8. The minimum wage in the Czech enterprises

    Directory of Open Access Journals (Sweden)

    Eva Lajtkepová

    2010-01-01

    Full Text Available Although the statutory minimum wage is not a new category, in the Czech Republic we encounter the definition and regulation of a minimum wage for the first time in the 1990 amendment to Act No. 65/1965 Coll., the Labour Code. The specific amount of the minimum wage and the conditions of its operation were then subsequently determined by government regulation in February 1991. Since that time, the value of minimum wage has been adjusted fifteenth times (the last increase was in January 2007. The aim of this article is to present selected results of two researches of acceptance of the statutory minimum wage by Czech enterprises. The first research makes use of the data collected by questionnaire research in 83 small and medium-sized enterprises in the South Moravia Region in 2005, the second one the data of 116 enterprises in the entire Czech Republic (in 2007. The data have been processed by means of the standard methods of descriptive statistics and of the appropriate methods of the statistical analyses (Spearman correlation coefficient of sequential correlation, Kendall coefficient, χ2 - independence test, Kruskal-Wallis test, and others.

  9. Binary Polymer Brushes of Strongly Immiscible Polymers.

    Science.gov (United States)

    Chu, Elza; Babar, Tashnia; Bruist, Michael F; Sidorenko, Alexander

    2015-06-17

    The phenomenon of microphase separation is an example of self-assembly in soft matter and has been observed in block copolymers (BCPs) and similar materials (i.e., supramolecular assemblies (SMAs) and homo/block copolymer blends (HBCs)). In this study, we use microphase separation to construct responsive polymer brushes that collapse to generate periodic surfaces. This is achieved by a chemical reaction between the minor block (10%, poly(4-vinylpyridine)) of the block copolymer and a substrate. The major block of polystyrene (PS) forms mosaic-like arrays of grafted patches that are 10-20 nm in size. Depending on the nature of the assembly (SMA, HBC, or neat BCP) and annealing method (exposure to vapors of different solvents or heating above the glass transition temperature), a range of "mosaic" brushes with different parameters can be obtained. Successive grafting of a secondary polymer (polyacrylamide, PAAm) results in the fabrication of binary polymer brushes (BPBs). Upon being exposed to specific selective solvents, BPBs may adopt different conformations. The surface tension and adhesion of the binary brush are governed by the polymer occupying the top stratum. The "mosaic" brush approach allows for a combination of strongly immiscible polymers in one brush. This facilitates substantial contrast in the surface properties upon switching, previously only possible for substrates composed of predetermined nanostructures. We also demonstrate a possible application of such PS/PAAm brushes in a tunable bioadhesion-bioadhesive (PS on top) or nonbioadhesive (PAAm on top) surface as revealed by Escherichia coli bacterial seeding.

  10. EDITORIAL: Electroactive polymer materials

    Science.gov (United States)

    Bar-Cohen, Yoseph; Kim, Kwang J.; Ryeol Choi, Hyouk; Madden, John D. W.

    2007-04-01

    years, a series of new materials have emerged that exhibit large displacement in response to electrical stimulation. This capability is making them highly attractive as actuators for their operational similarity to biological muscles, particularly their resilience, quiet operation, damage tolerance and ability to induce large actuation strains (stretching, contracting or bending). The application of these materials as actuators involves multi-disciplines including materials, electromechanics, chemistry, computers and electronics. Even though the force of actuation of existing EAP materials and their robustness requires further improvement, there has already been a series of reported successes in the development of EAP-actuated mechanisms. Using EAP to replace existing actuators may be a difficult challenge and therefore it is highly desirable to identify a niche application where EAP materials would not need to compete with existing technologies. EAP materials can be divided into two major groups based on their activation mechanism: ionic or electronic. Electronic EAPs, such as electrostrictive, electrostatic, piezoelectric and ferroelectric, are driven by Coulomb forces. These types of EAP material can be made to hold the induced displacement while activated under a DC voltage, allowing them to be considered for robotic applications. These materials have high mechanical energy density and they can be operated in air with no major constraints. However, electronic EAPs require high activation fields (>10 V/μm) that are close to the breakdown level. In contrast to electronic EAPs, ionic EAPs are materials that involve the transport of ions and they consist of two electrodes and an electrolyte. The activation of ionic EAPs can be achieved by voltages as low as 1-2 volts. Examples of ionic EAPs include gels, polymer-metal composites, conducting polymers and carbon nanotubes. Their disadvantages are a need to maintain wetness and their low electromechanical coupling

  11. Risk control and the minimum significant risk

    International Nuclear Information System (INIS)

    Seiler, F.A.; Alvarez, J.L.

    1996-01-01

    Risk management implies that the risk manager can, by his actions, exercise at least a modicum of control over the risk in question. In the terminology of control theory, a management action is a control signal imposed as feedback on the system to bring about a desired change in the state of the system. In the terminology of risk management, an action is taken to bring a predicted risk to lower values. Even if it is assumed that the management action taken is 100% effective and that the projected risk reduction is infinitely well known, there is a lower limit to the desired effects that can be achieved. It is based on the fact that all risks, such as the incidence of cancer, exhibit a degree of variability due to a number of extraneous factors such as age at exposure, sex, location, and some lifestyle parameters such as smoking or the consumption of alcohol. If the control signal is much smaller than the variability of the risk, the signal is lost in the noise and control is lost. This defines a minimum controllable risk based on the variability of the risk over the population considered. This quantity is the counterpart of the minimum significant risk which is defined by the uncertainties of the risk model. Both the minimum controllable risk and the minimum significant risk are evaluated for radiation carcinogenesis and are shown to be of the same order of magnitude. For a realistic management action, the assumptions of perfectly effective action and perfect model prediction made above have to be dropped, resulting in an effective minimum controllable risk which is determined by both risk limits. Any action below that effective limit is futile, but it is also unethical due to the ethical requirement of doing more good than harm. Finally, some implications of the effective minimum controllable risk on the use of the ALARA principle and on the evaluation of remedial action goals are presented

  12. Polymer gels and networks

    National Research Council Canada - National Science Library

    Osada, Yoshihito; Khokhlov, A. R

    2002-01-01

    ... or magnetic field, etc.). It was realized that not only can polymer gels absorb and hold a considerable volume of liquids, but they can also be forced to expel the absorbed liquid in a controlled manner. Of particular interest are hydrogels, i.e., polymer gels, which swell extensively in water. The most common hydrogels are polyelectrolyte gels: ...

  13. SANS studies of polymers

    International Nuclear Information System (INIS)

    Wignall, G.D.

    1985-01-01

    Some information provided by the application of small-angle neutron scattering concerning polymer structure is reviewed herein. Information about the polymer structure as examined in H 2 O/D 2 O mixtures is also provided. Examples of results of experiments performed at the National Center for Small-Angle Scattering Research are included

  14. Polymer based tunneling sensor

    Science.gov (United States)

    Cui, Tianhong (Inventor); Wang, Jing (Inventor); Zhao, Yongjun (Inventor)

    2006-01-01

    A process for fabricating a polymer based circuit by the following steps. A mold of a design is formed through a lithography process. The design is transferred to a polymer substrate through a hot embossing process. A metal layer is then deposited over at least part of said design and at least one electrical lead is connected to said metal layer.

  15. Polymers for Combating Biocorrosion

    Directory of Open Access Journals (Sweden)

    Jing Guo

    2018-03-01

    Full Text Available Biocorrosion has been considered as big trouble in many industries and marine environments due to causing of great economic loss. The main disadvantages of present approaches to prevent corrosion include being limited by environmental factors, being expensive, inapplicable to field, and sometimes inefficient. Studies show that polymer coatings with anticorrosion and antimicrobial properties have been widely accepted as a novel and effective approach to prevent biocorrosion. The main purpose of this review is to summarize up the progressive status of polymer coatings used for combating microbial corrosion. Polymers used to synthesize protective coatings are generally divided into three categories: (i traditional polymers incorporated with biocides, (ii antibacterial polymers containing quaternary ammonium compounds, and (iii conductive polymers. The strategies to synthesize polymer coatings resort mainly to grafting antibacterial polymers from the metal substrate surface using novel surface-functionalization approaches, such as free radical polymerization, chemically oxidative polymerization, and surface-initiated atom transfer radical polymerization, as opposed to the traditional approaches of dip coating or spin coating.

  16. Polymer light emitting diodes

    International Nuclear Information System (INIS)

    Gautier-Thianche, Emmmanuelle

    1998-01-01

    We study sandwich type semiconducting polymer light emitting diodes; anode/polymer/cathode. ITO is selected as anode, this polymer is a blend of a commercially available polymer with a high hole transport ability: polyvinyl-carbazole and a laser dye: coumarin-515. Magnesium covered with silver is chosen for the anode. We study the influence of polymer thickness and coumarin doping ratio on electroluminescence spectrum, electric characteristics and quantum efficiency. An important drawback is that diodes lifetime remains low. In the second part of our study we determine degradations causes with X-Ray reflectivity experiments. It may be due to ITO very high roughness. We realize a new type of planar electroluminescent device: a channel type electroluminescent device in which polymer layer is inserted into an aluminium channel. Such a device is by far more stable than using classical sandwich structures with the same polymer composition: indeed, charges are generated by internal-field ionization and there is no injection from the electrode to the polymer. This avoids electrochemical reactions at electrodes, thus reducing degradations routes. (author) [fr

  17. Polymers targeting habitual diseases

    Science.gov (United States)

    The use of polymeric drug conjugates mainly for the treatment for cancer therapy has been addressed, but these polymers also find their way in treatment of various lifestyle disorders like diabetes, hypertension, cardiovascular diseases etc. The focus is being laid to develop biodegradable polymer ...

  18. Stiff quantum polymers

    OpenAIRE

    Kleinert, H.

    2009-01-01

    At ultralow temperatures, polymers exhibit quantum behavior, which is calculated here for the second and fourth moments of the end-to-end distribution in the large-stiffness regime. The result should be measurable for polymers in wide optical traps.

  19. Conducting polymer hydrogels

    Czech Academy of Sciences Publication Activity Database

    Stejskal, Jaroslav

    2017-01-01

    Roč. 71, č. 2 (2017), s. 269-291 ISSN 0366-6352 R&D Projects: GA ČR(CZ) GA16-02787S Institutional support: RVO:61389013 Keywords : aerogel * conducting polymers * conductivity Subject RIV: CD - Macromolecular Chemistry OBOR OECD: Polymer science Impact factor: 1.258, year: 2016

  20. Minimum qualifications for nuclear criticality safety professionals

    International Nuclear Information System (INIS)

    Ketzlach, N.

    1990-01-01

    A Nuclear Criticality Technology and Safety Training Committee has been established within the U.S. Department of Energy (DOE) Nuclear Criticality Safety and Technology Project to review and, if necessary, develop standards for the training of personnel involved in nuclear criticality safety (NCS). The committee is exploring the need for developing a standard or other mechanism for establishing minimum qualifications for NCS professionals. The development of standards and regulatory guides for nuclear power plant personnel may serve as a guide in developing the minimum qualifications for NCS professionals

  1. A minimum achievable PV electrical generating cost

    International Nuclear Information System (INIS)

    Sabisky, E.S.

    1996-01-01

    The role and share of photovoltaic (PV) generated electricity in our nation's future energy arsenal is primarily dependent on its future production cost. This paper provides a framework for obtaining a minimum achievable electrical generating cost (a lower bound) for fixed, flat-plate photovoltaic systems. A cost of 2.8 $cent/kWh (1990$) was derived for a plant located in Southwestern USA sunshine using a cost of money of 8%. In addition, a value of 22 $cent/Wp (1990$) was estimated as a minimum module manufacturing cost/price

  2. Theory of polymer blends

    International Nuclear Information System (INIS)

    Curro, J.G.; Schweizer, K.S.

    1989-01-01

    We have recently developed a new theoretical approach to the study of polymer liquids. The theory is based on the ''reference interaction site model'' (RISM theory) of Chandler and Andersen, which has been successful in describing the structure of small molecule liquids. We have recently extended our polymer RISM theory to the case of polymer blends. In the present investigation we have applied this theory to two special binary blends: (1) the athermal mixture where we isolate structural effects, and (2) the isotopic mixture in which structurally identical polymer chains interact with dissimilar attractive interactions. By studying these two special cases we are able to obtain insights into the molecular factors which control the miscibility in polymer mixtures. 18 refs., 2 figs

  3. Ion Implantation of Polymers

    DEFF Research Database (Denmark)

    Popok, Vladimir

    2012-01-01

    The current paper presents a state-of-the-art review in the field of ion implantation of polymers. Numerous published studies of polymers modified by ion beams are analysed. General aspects of ion stopping, latent track formation and changes of structure and composition of organic materials...... are discussed. Related to that, the effects of radiothermolysis, degassing and carbonisation are considered. Specificity of depth distributions of implanted into polymers impurities is analysed and the case of high-fluence implantation is emphasised. Within rather broad topic of ion bombardment, the focus...... is put on the low-energy implantation of metal ions causing the nucleation and growth of nanoparticles in the shallow polymer layers. Electrical, optical and magnetic properties of metal/polymer composites are under the discussion and the approaches towards practical applications are overviewed....

  4. All Polymer Micropump

    DEFF Research Database (Denmark)

    Hansen, Thomas Steen

    2008-01-01

    In this thesis an all polymer micropump, and the fabrication method required to fabricate this, are examined. Polymer microfluidic. devices are of major scientific interest because they can combine complicated chemical and biological analys~s in cheap and disposable devices. The electrode system...... in the micropump is based on the conducting polymer poly(3,4 ethylenedioxythiophene) (PEDOT). The majority of the work conducted was therefore aimed at developing methods for patterning and processing PEDOT. First a method was developed, where the conducting polymer PEDOT can be integrated into non...... of the substrate, the PEDOT is integrated into the non-conductive polymer. The result is a material that retains the good conductivity of PEDOT, but gains the mechanical stability of the substrate. The best results were obtained for PEDOTjPMMA. The new mechanically stable PEDOTjPMMA was micro-patterned using clean...

  5. Polymer wear evaluation

    DEFF Research Database (Denmark)

    Lagerbon, Mikkel; Sivebæk, Ion Marius

    2012-01-01

    Polymer wear plays an increasing role in manufacturing of machine parts for e.g. medical devices. Some of these have an expected lifetime of five to eight years during which very little wear of the components is acceptable. Too much wear compromises the dosage accuracy of the device and thereby...... the safety of the patients. Prediction of the wear of polymers is complicated by the low thermal conductivity of this kind of material. It implies that any acceleration of testing conditions by increased contact pressure and/or sliding velocity will make the polymer fail due to exaggerated heat buildup....... This is not the kind of wear observed in medical devices. In the present work a method was developed capable of evaluating the wear progression in polymer-polymer contacts. The configuration of the setup is injection moulded specimens consisting of an upper part having a toroid shape and a lower flat part. The sliding...

  6. Discretization of space and time: determining the values of minimum length and minimum time

    OpenAIRE

    Roatta , Luca

    2017-01-01

    Assuming that space and time can only have discrete values, we obtain the expression of the minimum length and the minimum time interval. These values are found to be exactly coincident with the Planck's length and the Planck's time but for the presence of h instead of ħ .

  7. Positron beam analysis of polymer/metal interfaces under stress

    NARCIS (Netherlands)

    Escobar Galindo, R.; van Veen, A.; Garcia, A.A.; Schut, H.; de Hosson, J.T.M.; Triftshauser, W; Kogel, G; Sperr, P

    2001-01-01

    The polymers Epoxy and Poly(Methyl MethAcrylate) spin coated on Interstitial Free (IF) steel were subjected to external stresses and studied using the Delft Variable Energy Positron (VEP) beam facility. The polymer/metal interface was identified using an S-W map. After tensile experiments vacancy

  8. Revisiting the role of durable polymers in cardiovascular devices.

    Science.gov (United States)

    Mori, Hiroyoshi; Otsuka, Fumiyuki; Gupta, Anuj; Jinnouchi, Hiroyuki; Torii, Sho; Harari, Emanuel; Virmani, Renu; Finn, Aloke V

    2017-11-01

    Polymers are an essential component of drug-eluting stents (DES) used to control drug release but remain the most controversial component of DES technology. There are two types of polymers employed in DES: durable polymer based DES (DP-DES) and biodegradable polymer DES (BP-DES). First-generation DES were exclusively composed of DP and demonstrated increased rates of late stent failure due in part to poor polymer biocompatibility. Newer generations DES use more biocompatible durable polymers or biodegradable polymers. Areas covered: We will cover issues identified with 1st-generation DP-DES, areas of success and failure in 2nd-generation DP-DES and examine the promise and shortcomings of BP-DES. Briefly, fluorinated polymers used in 2nd-generation DP-DES have excellent anti-thrombogenicity and better biocompatibility than 1st-generation DES polymers. However, these devices lead to persistent drug exposure to the endothelium which impairs endothelial function and predisposes towards neoatherosclerosis. Meanwhile, BP-DES has shortened the duration of drug exposure which might be beneficial for endothelial functional recovery leading to less neoatherosclerosis. However, it remains uncertain whether the long-term biocompatibility of bare metal surfaces is better than that of polymer-coated metals. Expert commentary: Each technology has distinct advantages, which can be optimized depending upon the particular characteristics of the patient being treated.

  9. Polymers in the gut compress the colonic mucus hydrogel.

    Science.gov (United States)

    Datta, Sujit S; Preska Steinberg, Asher; Ismagilov, Rustem F

    2016-06-28

    Colonic mucus is a key biological hydrogel that protects the gut from infection and physical damage and mediates host-microbe interactions and drug delivery. However, little is known about how its structure is influenced by materials it comes into contact with regularly. For example, the gut abounds in polymers such as dietary fibers or administered therapeutics, yet whether such polymers interact with the mucus hydrogel, and if so, how, remains unclear. Although several biological processes have been identified as potential regulators of mucus structure, the polymeric composition of the gut environment has been ignored. Here, we demonstrate that gut polymers do in fact regulate mucus hydrogel structure, and that polymer-mucus interactions can be described using a thermodynamic model based on Flory-Huggins solution theory. We found that both dietary and therapeutic polymers dramatically compressed murine colonic mucus ex vivo and in vivo. This behavior depended strongly on both polymer concentration and molecular weight, in agreement with the predictions of our thermodynamic model. Moreover, exposure to polymer-rich luminal fluid from germ-free mice strongly compressed the mucus hydrogel, whereas exposure to luminal fluid from specific-pathogen-free mice-whose microbiota degrade gut polymers-did not; this suggests that gut microbes modulate mucus structure by degrading polymers. These findings highlight the role of mucus as a responsive biomaterial, and reveal a mechanism of mucus restructuring that must be integrated into the design and interpretation of studies involving therapeutic polymers, dietary fibers, and fiber-degrading gut microbes.

  10. Electroactive polymers for healthcare and biomedical applications

    Science.gov (United States)

    Bauer, Siegfried

    2017-04-01

    Electroactivity was noticed early in biological substances, including proteins, polynucleotides and enzymes, even piezoand pyroelectricity were found in wool, hair, wood, bone and tendon. Recently, ferroelectricity has been identified in a surprisingly large number of biologically relevant materials, including hydroxyapatite, aortic walls and elastin. Inspired by the variety of natural electroactive materials, a wealth of new elastomers and polymers were designed recently, including an all organic elastomer electret and self-healing dielectric elastomers. Let's further draw inspiration from nature and widen the utilization of electroactive polymers towards (mobile) healthcare and biomedical applications. Ferroelectrets, internally charged polymer foams with a strong piezoelectric thickness coefficient are employed in biomedical sensing, for example as blood pressure and pulse sensor, as vital signs monitor or for the detection of tonicclonic seizures. Piezo- and pyroelectric polymers are booming in printed electronics research. They provide electronic skin the ability to "feel" pressure and temperature changes, or to generate electrical energy from vibrations and motions, even from contractile and relaxation motions of the heart and lung. Dielectric elastomers are pioneered by StretchSense as wearable motion capture sensors, monitoring pressure, stretch, bend and shear, quantifying comfort in sports and healthcare. On the cellular level, electroactive polymer arrays are used to study mechanotransduction of individual cells. Ionic electroactive polymers show potential to be used in implantable electroactive biomedical devices. Already with the currently available science and technology, we are at the verge of witnessing the demonstration of truly complex bionic systems.

  11. Development of polymer concrete radioactive waste management containers

    Energy Technology Data Exchange (ETDEWEB)

    Chung, H.; Lee, M. S.; Ahn, D. H.; Won, H. J.; Kang, H. S.; Lee, H. S.; Lim, S.P.; Kim, Y. E.; Lee, B. O.; Lee, K. P.; Min, B. Y.; Lee, J.K.; Jang, W. S.; Sim, W. B.; Lee, J. C.; Park, M. J.; Choi, Y. J.; Shin, H. E.; Park, H. Y.; Kim, C. Y

    1999-11-01

    A high-integrity radioactive waste container has been developed to immobilize the spent resin wastes from nuclear power plants, protect possible future, inadvertent intruders from damaging radiation. The polymer concrete container is designed to ensure safe and reliable disposal of the radioactive waste for a minimum period of 300 years. A built-in vent system for each container will permit the release of gas. An experimental evaluation of the mechanical, chemical, and biological tests of the container was carried out. The tests showed that the polymer concrete container is adequate for safe disposal of the radioactive wastes. (author)

  12. A polymer driveshaft for use in orbital and rotational atherectomy

    Science.gov (United States)

    Grothe, Preston Lee

    Driveshafts used in atherectomy medical devices are often comprised of coiled or braided metal wires. These constructions are designed to tolerate delivery through tortuous vessels and can endure high speed rotation used during activation of the atherectomy treatment. This research investigated polymer driveshaft designs, which were comprised of polymer inner and outer layers, and coiled or braided stainless steel wires. The polymer driveshaft materials included polyimide, nylon 12, and polytetrafluoroethylene (PTFE). Mechanical testing of polymer driveshafts was conducted to determine material response in bending, tension, compression, and torsion. The polymer driveshaft test results were then compared with current coiled metal wire driveshaft constructions. The investigation identified polymer driveshaft options that could feasibly work in an atherectomy application.

  13. MINIMUM AREAS FOR ELEMENTARY SCHOOL BUILDING FACILITIES.

    Science.gov (United States)

    Pennsylvania State Dept. of Public Instruction, Harrisburg.

    MINIMUM AREA SPACE REQUIREMENTS IN SQUARE FOOTAGE FOR ELEMENTARY SCHOOL BUILDING FACILITIES ARE PRESENTED, INCLUDING FACILITIES FOR INSTRUCTIONAL USE, GENERAL USE, AND SERVICE USE. LIBRARY, CAFETERIA, KITCHEN, STORAGE, AND MULTIPURPOSE ROOMS SHOULD BE SIZED FOR THE PROJECTED ENROLLMENT OF THE BUILDING IN ACCORDANCE WITH THE PROJECTION UNDER THE…

  14. Dirac's minimum degree condition restricted to claws

    NARCIS (Netherlands)

    Broersma, Haitze J.; Ryjacek, Z.; Schiermeyer, I.

    1997-01-01

    Let G be a graph on n 3 vertices. Dirac's minimum degree condition is the condition that all vertices of G have degree at least . This is a well-known sufficient condition for the existence of a Hamilton cycle in G. We give related sufficiency conditions for the existence of a Hamilton cycle or a

  15. 7 CFR 33.10 - Minimum requirements.

    Science.gov (United States)

    2010-01-01

    ... Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... ISSUED UNDER AUTHORITY OF THE EXPORT APPLE ACT Regulations § 33.10 Minimum requirements. No person shall... shipment of apples to any foreign destination unless: (a) Apples grade at least U.S. No. 1 or U.S. No. 1...

  16. Minimum Risk Pesticide: Definition and Product Confirmation

    Science.gov (United States)

    Minimum risk pesticides pose little to no risk to human health or the environment and therefore are not subject to regulation under FIFRA. EPA does not do any pre-market review for such products or labels, but violative products are subject to enforcement.

  17. The Minimum Distance of Graph Codes

    DEFF Research Database (Denmark)

    Høholdt, Tom; Justesen, Jørn

    2011-01-01

    We study codes constructed from graphs where the code symbols are associated with the edges and the symbols connected to a given vertex are restricted to be codewords in a component code. In particular we treat such codes from bipartite expander graphs coming from Euclidean planes and other...... geometries. We give results on the minimum distances of the codes....

  18. Minimum maintenance solar pump | Assefa | Zede Journal

    African Journals Online (AJOL)

    A minimum maintenance solar pump (MMSP), Fig 1, has been simulated for Addis Ababa, taking solar meteorological data of global radiation, diffuse radiation and ambient air temperature as input to a computer program that has been developed. To increase the performance of the solar pump, by trapping the long-wave ...

  19. Context quantization by minimum adaptive code length

    DEFF Research Database (Denmark)

    Forchhammer, Søren; Wu, Xiaolin

    2007-01-01

    Context quantization is a technique to deal with the issue of context dilution in high-order conditional entropy coding. We investigate the problem of context quantizer design under the criterion of minimum adaptive code length. A property of such context quantizers is derived for binary symbols....

  20. 7 CFR 35.13 - Minimum quantity.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Minimum quantity. 35.13 Section 35.13 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... part, transport or receive for transportation to any foreign destination, a shipment of 25 packages or...

  1. Minimum impact house prototype for sustainable building

    NARCIS (Netherlands)

    Götz, E.; Klenner, K.; Lantelme, M.; Mohn, A.; Sauter, S.; Thöne, J.; Zellmann, E.; Drexler, H.; Jauslin, D.

    2010-01-01

    The Minihouse is a prototupe for a sustainable townhouse. On a site of only 29 sqm it offers 154 sqm of urban life. The project 'Minimum Impact House' adresses two important questions: How do we provide living space in the cities without distroying the landscape? How to improve sustainably the

  2. 49 CFR 639.27 - Minimum criteria.

    Science.gov (United States)

    2010-10-01

    ... dollar value to any non-financial factors that are considered by using performance-based specifications..., DEPARTMENT OF TRANSPORTATION CAPITAL LEASES Cost-Effectiveness § 639.27 Minimum criteria. In making the... used where possible and appropriate: (a) Operation costs; (b) Reliability of service; (c) Maintenance...

  3. Computing nonsimple polygons of minimum perimeter

    NARCIS (Netherlands)

    Fekete, S.P.; Haas, A.; Hemmer, M.; Hoffmann, M.; Kostitsyna, I.; Krupke, D.; Maurer, F.; Mitchell, J.S.B.; Schmidt, A.; Schmidt, C.; Troegel, J.

    2018-01-01

    We consider the Minimum Perimeter Polygon Problem (MP3): for a given set V of points in the plane, find a polygon P with holes that has vertex set V , such that the total boundary length is smallest possible. The MP3 can be considered a natural geometric generalization of the Traveling Salesman

  4. Minimum-B mirrors plus EBT principles

    International Nuclear Information System (INIS)

    Yoshikawa, S.

    1983-01-01

    Electrons are heated at the minimum B location(s) created by the multipole field and the toroidal field. Resulting hot electrons can assist plasma confinement by (1) providing mirror, (2) creating azimuthally symmetric toroidal confinement, or (3) creating modified bumpy torus

  5. Completeness properties of the minimum uncertainty states

    Science.gov (United States)

    Trifonov, D. A.

    1993-01-01

    The completeness properties of the Schrodinger minimum uncertainty states (SMUS) and of some of their subsets are considered. The invariant measures and the resolution unity measures for the set of SMUS are constructed and the representation of squeezing and correlating operators and SMUS as superpositions of Glauber coherent states on the real line is elucidated.

  6. Minimum Description Length Shape and Appearance Models

    DEFF Research Database (Denmark)

    Thodberg, Hans Henrik

    2003-01-01

    The Minimum Description Length (MDL) approach to shape modelling is reviewed. It solves the point correspondence problem of selecting points on shapes defined as curves so that the points correspond across a data set. An efficient numerical implementation is presented and made available as open s...

  7. Faster Fully-Dynamic minimum spanning forest

    DEFF Research Database (Denmark)

    Holm, Jacob; Rotenberg, Eva; Wulff-Nilsen, Christian

    2015-01-01

    We give a new data structure for the fully-dynamic minimum spanning forest problem in simple graphs. Edge updates are supported in O(log4 n/log logn) expected amortized time per operation, improving the O(log4 n) amortized bound of Holm et al. (STOC’98, JACM’01).We also provide a deterministic data...

  8. Minimum Wage Effects throughout the Wage Distribution

    Science.gov (United States)

    Neumark, David; Schweitzer, Mark; Wascher, William

    2004-01-01

    This paper provides evidence on a wide set of margins along which labor markets can adjust in response to increases in the minimum wage, including wages, hours, employment, and ultimately labor income. Not surprisingly, the evidence indicates that low-wage workers are most strongly affected, while higher-wage workers are little affected. Workers…

  9. Asymptotics for the minimum covariance determinant estimator

    NARCIS (Netherlands)

    Butler, R.W.; Davies, P.L.; Jhun, M.

    1993-01-01

    Consistency is shown for the minimum covariance determinant (MCD) estimators of multivariate location and scale and asymptotic normality is shown for the former. The proofs are made possible by showing a separating ellipsoid property for the MCD subset of observations. An analogous property is shown

  10. Chemical Markup, XML and the World-Wide Web. 8. Polymer Markup Language.

    Science.gov (United States)

    Adams, Nico; Winter, Jerry; Murray-Rust, Peter; Rzepa, Henry S

    2008-11-01

    Polymers are among the most important classes of materials but are only inadequately supported by modern informatics. The paper discusses the reasons why polymer informatics is considerably more challenging than small molecule informatics and develops a vision for the computer-aided design of polymers, based on modern semantic web technologies. The paper then discusses the development of Polymer Markup Language (PML). PML is an extensible language, designed to support the (structural) representation of polymers and polymer-related information. PML closely interoperates with Chemical Markup Language (CML) and overcomes a number of the previously identified challenges.

  11. Planetary tides during the Maunder sunspot minimum

    International Nuclear Information System (INIS)

    Smythe, C.M.; Eddy, J.A.

    1977-01-01

    Sun-centered planetary conjunctions and tidal potentials are here constructed for the AD1645 to 1715 period of sunspot absence, referred to as the 'Maunder Minimum'. These are found to be effectively indistinguishable from patterns of conjunctions and power spectra of tidal potential in the present era of a well established 11 year sunspot cycle. This places a new and difficult restraint on any tidal theory of sunspot formation. Problems arise in any direct gravitational theory due to the apparently insufficient forces and tidal heights involved. Proponents of the tidal hypothesis usually revert to trigger mechanisms, which are difficult to criticise or test by observation. Any tidal theory rests on the evidence of continued sunspot periodicity and the substantiation of a prolonged period of solar anomaly in the historical past. The 'Maunder Minimum' was the most drastic change in the behaviour of solar activity in the last 300 years; sunspots virtually disappeared for a 70 year period and the 11 year cycle was probably absent. During that time, however, the nine planets were all in their orbits, and planetary conjunctions and tidal potentials were indistinguishable from those of the present era, in which the 11 year cycle is well established. This provides good evidence against the tidal theory. The pattern of planetary tidal forces during the Maunder Minimum was reconstructed to investigate the possibility that the multiple planet forces somehow fortuitously cancelled at the time, that is that the positions of the slower moving planets in the 17th and early 18th centuries were such that conjunctions and tidal potentials were at the time reduced in number and force. There was no striking dissimilarity between the time of the Maunder Minimum and any period investigated. The failure of planetary conjunction patterns to reflect the drastic drop in sunspots during the Maunder Minimum casts doubt on the tidal theory of solar activity, but a more quantitative test

  12. Experimental investigation of the factors influencing the polymer-polymer bond strength during two component injection moulding

    DEFF Research Database (Denmark)

    Islam, Mohammad Aminul; Hansen, Hans Nørgaard; Tang, Peter Torben

    2007-01-01

    Two component injection moulding is a commercially important manufacturing process and a key technology for Moulded Interconnect Devices (MIDs). Many fascinating applications of two component or multi component polymer parts are restricted due to the weak interfacial adhesion of the polymers...... effectively control the adhesion between two polymers. The effects of environmental conditions on the bond strength after moulding are also investigated. The material selections and environmental conditions were chosen based on the suitability of MID production, but the results and discussion presented....... A thorough understanding of the factors that influence the bond strength of polymers is necessary for multi component polymer processing. This paper investigates the effects of the process and material parameters on the bond strength of two component polymer parts and identifies the factors which can...

  13. Experimental investigation of the factors influencing the polymer-polymer bond strength during two-component injection moulding

    DEFF Research Database (Denmark)

    Islam, Aminul; Hansen, Hans Nørgaard; Bondo, Martin

    2010-01-01

    Two-component injection moulding is a commercially important manufacturing process and a key technology for combining different material properties in a single plastic product. It is also one of most industrially adaptive process chain for manufacturing so-called moulded interconnect devices (MIDs......). Many fascinating applications of two-component or multi-component polymer parts are restricted due to the weak interfacial adhesion of the polymers. A thorough understanding of the factors that influence the bond strength of polymers is necessary for multi-component polymer processing. This paper...... investigates the effects of the process conditions and geometrical factors on the bond strength of two-component polymer parts and identifies the factors which can effectively control the adhesion between two polymers. The effects of environmental conditions on the bond strength are also investigated...

  14. Photoluminescence in conjugated polymers

    International Nuclear Information System (INIS)

    Furst, J.E.; Laugesen, R.; Dastoor, P.; McNeill, C.

    2002-01-01

    Full text: Conjugated polymers combine the electronic and optical properties of semiconductors with the processability of polymers. They contain a sequence of alternate single and double carbon bonds so that the overlap of unhybridised p z orbitals creates a delocalised ρ system which gives semiconducting properties with p-bonding (valence) and p* -antibonding (conduction) bands. Photoluminesence (PL) in conjugated polymers results from the radiative decay of singlet excitons confined to a single chain. The present work is the first in a series of studies in our laboratory that will characterize the optical properties of conjugated polymers. The experiment involves the illumination of thin films of conjugated polymer with UV light (I=360 nm) and observing the subsequent fluorescence using a custom-built, fluorescence spectrometer. Photoluminesence spectra provide basic information about the structure of the polymer film. A typical spectrum is shown in the accompanying figure. The position of the first peak is related to the polymer chain length and resolved multiple vibronic peaks are an indication of film structure and morphology. We will also present results related to the optical degradation of these materials when exposed to air and UV light

  15. Detailed spectroscopy in the superdeformed second minimum of 240Pu

    International Nuclear Information System (INIS)

    Thirolf, P.G.; Gassmann, D.; Habs, D.; Chromik, M.J.; Eisermann, Y.; Graw, G.; Hertenberger, R.; Maier, H.J.; Metz, A.; Reiter, P.

    2000-01-01

    Complete text of publication follows. Superdeformed prolate nuclei, having an axis ratio of about 2:1, have first been discovered in fission isomers in the actinide region almost 40 years ago by Polikanov et al.. Their interpretation of being the result of microscopic shell corrections on top of the macroscopic liquid drop potential leading to a second minimum in the nuclear potential energy surface is well established. 240 Pu with its 3.7 ns fission isomer may be regarded as the prototype nucleus for spectroscopic studies of superdeformed actinide nuclei since the identification of the ground state rotational band in conversion electron measurements [1]. Though from the knowledge on excited states in the first minimum and previous measurements in the second minimum low-lying collective excitations in the second minimum low-lying collective excitations in the second well of 240 Pu can be expected, none of them has been experimentally identified so far. Quite surprisingly, no low-lying collective quadrupole excitations could be observed in a recent detailed high-resolution and high-efficiency γ-spectroscopy experiment [2]. Complementary information could be obtained in conversion electron measurements in coincidence with isomeric fission performed at the Garching Accelerator Laboratory, resulting in the first identification of the lowest β-vibrational band [3]. In a combined analysis of the γ-spectroscopic and conversion electron data conversion coefficients α K or limits on α K could be deduced, thus allowing to determine the multipolarities of the transitions. A predominant population of negative parity states in the second well could be observed that can be explained by the filtering function of the inner and outer fission barrier. Complementary transmission resonance measurements have been performed, yielding new information on the fine structure of (β-)vibrational multi-phonon states. A new method could be established to determine the excitation energy of

  16. 40 CFR 721.9492 - Polymers of styrene, cyclohexyl methacrylate and substituted methacrylate.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Polymers of styrene, cyclohexyl... Significant New Uses for Specific Chemical Substances § 721.9492 Polymers of styrene, cyclohexyl methacrylate...) The chemical substances identified generically as polymers of styrene, cyclohexyl methacrylate and...

  17. 40 CFR 721.3810 - Formaldehyde, polymers with substituted phenols (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Formaldehyde, polymers with... New Uses for Specific Chemical Substances § 721.3810 Formaldehyde, polymers with substituted phenols... identified generically as Formaldehyde, polymers with substituted phenols (PMN P-99-0558) is subject to...

  18. 40 CFR 721.10017 - Amine terminated bisphenol A diglycidyl ether polymer (generic).

    Science.gov (United States)

    2010-07-01

    ... diglycidyl ether polymer (generic). 721.10017 Section 721.10017 Protection of Environment ENVIRONMENTAL... ether polymer (generic). (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substances identified generically as amine terminated bisphenol A diglycidyl ether polymer (PMNs P...

  19. 21 CFR 178.3790 - Polymer modifiers in semirigid and rigid vinyl chloride plastics.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polymer modifiers in semirigid and rigid vinyl...: ADJUVANTS, PRODUCTION AIDS, AND SANITIZERS Certain Adjuvants and Production Aids § 178.3790 Polymer modifiers in semirigid and rigid vinyl chloride plastics. The polymers identified in paragraph (a) of this...

  20. 40 CFR 721.7220 - Polymer of substituted phenol, formaldehyde, epichlorohydrin, and disubstituted benzene.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Polymer of substituted phenol... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.7220 Polymer of substituted phenol... subject to reporting. (1) The chemical substance identified generically as polymer of substituted phenol...

  1. 21 CFR 177.1020 - Acrylonitrile/butadiene/sty-rene co-polymer.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acrylonitrile/butadiene/sty-rene co-polymer. 177... SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances.../butadiene/sty-rene co-polymer. Acrylonitrile/butadiene/styrene copolymer identified in this section may be...

  2. 40 CFR 721.7000 - Polymer of disodium maleate, allyl ether, and ethylene oxide.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Polymer of disodium maleate, allyl... New Uses for Specific Chemical Substances § 721.7000 Polymer of disodium maleate, allyl ether, and... substance identified generically as a polymer of disodium maleate, allyl ether, and ethylene oxide (P-91...

  3. Biomedical applications of polymers

    CERN Document Server

    Gebelein, C G

    1991-01-01

    The biomedical applications of polymers span an extremely wide spectrum of uses, including artificial organs, skin and soft tissue replacements, orthopaedic applications, dental applications, and controlled release of medications. No single, short review can possibly cover all these items in detail, and dozens of books andhundreds of reviews exist on biomedical polymers. Only a few relatively recent examples will be cited here;additional reviews are listed under most of the major topics in this book. We will consider each of the majorclassifications of biomedical polymers to some extent, inclu

  4. SANS studies of polymers

    International Nuclear Information System (INIS)

    Wignall, G.D.

    1984-10-01

    Before small-angle neutron scattering (SANS), chain conformation studies were limited to light and small angle x-ray scattering techniques, usually in dilute solution. SANS from blends of normal and labeled molecules could give direct information on chain conformation in bulk polymers. Water-soluble polymers may be examined in H 2 O/D 2 O mixtures using contrast variation methods to provide further information on polymer structure. This paper reviews some of the information provided by this technique using examples of experiments performed at the National Center for Small-Angle Scattering Research (NCSASR)

  5. Development of Silicate Polymers

    DEFF Research Database (Denmark)

    Søgaard, Erik Gydesen; Simonsen, Morten Enggrob

      The development of inorganic polymers is a new promising technology that may be used in many applications. The syntheses of inorganic polymers are normally carried out either by mixing an amorphous material for example silicium dioxide with a mineral base or dissolving metal oxids or metal...... hydroxide in acid and increase pH to saturation of the metal hydroxide. It is assumed that the syntheses of the inorganic polymer are carried out through polymerisation of oligomers (dimer, trimer) which provide the actual unit structures of the three dimensional macromolecular structure. In this work...

  6. Soluble porphyrin polymers

    Science.gov (United States)

    Gust, Jr., John Devens; Liddell, Paul Anthony

    2015-07-07

    Porphyrin polymers of Structure 1, where n is an integer (e.g., 1, 2, 3, 4, 5, or greater) ##STR00001## are synthesized by the method shown in FIGS. 2A and 2B. The porphyrin polymers of Structure 1 are soluble in organic solvents such as 2-MeTHF and the like, and can be synthesized in bulk (i.e., in processes other than electropolymerization). These porphyrin polymers have long excited state lifetimes, making the material suitable as an organic semiconductor for organic electronic devices including transistors and memories, as well as solar cells, sensors, light-emitting devices, and other opto-electronic devices.

  7. Radiation chemistry of biologically compatible polymers

    International Nuclear Information System (INIS)

    Hill, D.J. T.; Pomery, P.J.; Saadat, G.; Whittaker, A.K.

    1996-01-01

    Full text: Poly (2-hydroxy ethyl methacrylate) [PHEMA] and poly (2-ethoxy ethyl methacrylate) [PEEMA] are of biomedical and industrial interest due to their biocompatibility with living tissue. In this paper the effect of high energy radiation on these polymers is reported. PHEMA and PEEMA have similar molecular structures to poly (methyl methacrylate)[PMMA], and the γ irradiation of this polymer is well understood. Hence the radiation chemistry of PMMA is used as model system for the the analysis of the radiation chemistry of these polymers. The mechanism of the radiation induced chemistry of the polymers has been investigated using a range of techniques including electron spin resonance spectroscopy (ESR) to establish free radical pathways, GC to identify small molecule volatile products, NMR to identify small molecule radiation products and Gel Permeation Chromatography (GPC) to determine molecular weight changes. Whilst much of the major part of the radiation chemistry can be attributed to similar reactions which can be observed in PMMA, there are a number of new radicals which are present as a result of the influence of the side chain interactions which reduces the mobility of the polymer chain

  8. Statistical properties of curved polymer

    Indian Academy of Sciences (India)

    respective ground states decide the conformational statistics of the polymer. For semiflexible polymers, the relevant non-dimensional quantity is lp/L, where lp is the persistence length (which is proportional to the bending modulus k) and L is the contour length of the polymer. In the limit, lp/L ≪ 1, the polymer behaves as.

  9. Nowcasting daily minimum air and grass temperature

    Science.gov (United States)

    Savage, M. J.

    2016-02-01

    Site-specific and accurate prediction of daily minimum air and grass temperatures, made available online several hours before their occurrence, would be of significant benefit to several economic sectors and for planning human activities. Site-specific and reasonably accurate nowcasts of daily minimum temperature several hours before its occurrence, using measured sub-hourly temperatures hours earlier in the morning as model inputs, was investigated. Various temperature models were tested for their ability to accurately nowcast daily minimum temperatures 2 or 4 h before sunrise. Temperature datasets used for the model nowcasts included sub-hourly grass and grass-surface (infrared) temperatures from one location in South Africa and air temperature from four subtropical sites varying in altitude (USA and South Africa) and from one site in central sub-Saharan Africa. Nowcast models used employed either exponential or square root functions to describe the rate of nighttime temperature decrease but inverted so as to determine the minimum temperature. The models were also applied in near real-time using an open web-based system to display the nowcasts. Extrapolation algorithms for the site-specific nowcasts were also implemented in a datalogger in an innovative and mathematically consistent manner. Comparison of model 1 (exponential) nowcasts vs measured daily minima air temperatures yielded root mean square errors (RMSEs) <1 °C for the 2-h ahead nowcasts. Model 2 (also exponential), for which a constant model coefficient ( b = 2.2) was used, was usually slightly less accurate but still with RMSEs <1 °C. Use of model 3 (square root) yielded increased RMSEs for the 2-h ahead comparisons between nowcasted and measured daily minima air temperature, increasing to 1.4 °C for some sites. For all sites for all models, the comparisons for the 4-h ahead air temperature nowcasts generally yielded increased RMSEs, <2.1 °C. Comparisons for all model nowcasts of the daily grass

  10. Study of Hydrophobic and Ionizable Hydrophilic Copolymers at Polymer/Solid and Polymer/Liquid Interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Perahia, Dvora

    2011-11-01

    Joint experimental-computational efforts were set to characterize the interfacial effects on the structure and dynamics of polymers consisting of highly rigid hydrophilic-ionizable and hydrophobic sub-units within one polymeric chain casted into thin films of several molecular dimensions. Focusing on the ultra thin film region we separate out the interfacial effects from bulk characteristics. Specifically, the study sought to: identify the parameters that control the formation of a stable polymer-solid interface. The study consists of two components, experimental investigations and computational efforts. The experimental component was designed to derive empirical trends that can be used to correlate the set of coupled polymer molecular parameters with the interfacial characteristics of these polymers, and their response to presence of solvents. The computational study was designed to provide molecular insight into the ensemble averages provided by the experimental efforts on multiple length scales from molecular dimensions, to the nanometer lengths to a macroscopic understanding of solvent interactions with structured polymers. With the ultimate goal of correlating molecular parameters to structure, dynamics and properties of ionic polymers, the first stage of the research began with the study of two systems, one which allowed tailoring the flexibility of the backbone without the presence of ionic groups, but with a potential to sulfonate groups at a later stage, and a polymer whose backbone is rigid and the density of the ionic group can be varied. The combined experimental and computational studies significantly extended the understanding of polymers at interfaces from model systems to polydispersed copolymers with blocks of varying nature and complexity. This new insight directly affects the design of polymers for sustainable energy applications from batteries and fuel cells to solar energy.

  11. Application of dimensional regularization to single chain polymer static properties: Conformational space renormalization of polymers. III

    International Nuclear Information System (INIS)

    Oono, Y.; Ohta, T.; Freed, K.F.

    1981-01-01

    A dimensional regularization approach to the renormalization group treatment of polymer excluded volume is formulated in chain conformation space where monomers are specified by their spatial positions and their positions along the chain and the polymers may be taken to be monodisperse. The method utilizes basic scale invariance considerations. First, it is recognized that long wavelength macroscopic descriptions must be well defined in the limit that the minimum atomic or molecular scale L is set to zero. Secondly, the microscopic theory is independent of the conveniently chosen macroscopic scale of length k. The freedom of choice of k is exploited along with the assumed renormalizability of the theory to provide the renormalization group equations which directly imply the universal scaling laws for macroscopic properties. The renormalizability of the model implies the existence of the general relations between the basic macroparameters, such as chain length, excluded volume, etc., and their microscopic counterparts in the microscopic model for the system. These macro--micro relations are defined through the condition that macroscopic quantities be well defined for polymer chains for any spatial dimensionality. The method is illustrated by calculating the end vector distribution function for all values of end vectors R. The evaluation of this distribution function currently requires the use of expansions in e = 4-d. In this case our distribution reduces to known limits for R→0 or infinity. Subsequent papers will present calculations of the polymer coherent scattering function, the monomer spatial distribution function, and concentration dependent properties

  12. Measurement of Minimum Bias Observables with ATLAS

    CERN Document Server

    Kvita, Jiri; The ATLAS collaboration

    2017-01-01

    The modelling of Minimum Bias (MB) is a crucial ingredient to learn about the description of soft QCD processes. It has also a significant relevance for the simulation of the environment at the LHC with many concurrent pp interactions (“pileup”). The ATLAS collaboration has provided new measurements of the inclusive charged particle multiplicity and its dependence on transverse momentum and pseudorapidity in special data sets with low LHC beam currents, recorded at center of mass energies of 8 TeV and 13 TeV. The measurements cover a wide spectrum using charged particle selections with minimum transverse momentum of both 100 MeV and 500 MeV and in various phase space regions of low and high charged particle multiplicities.

  13. Minimum wakefield achievable by waveguide damped cavity

    International Nuclear Information System (INIS)

    Lin, X.E.; Kroll, N.M.

    1995-01-01

    The authors use an equivalent circuit to model a waveguide damped cavity. Both exponentially damped and persistent (decay t -3/2 ) components of the wakefield are derived from this model. The result shows that for a cavity with resonant frequency a fixed interval above waveguide cutoff, the persistent wakefield amplitude is inversely proportional to the external Q value of the damped mode. The competition of the two terms results in an optimal Q value, which gives a minimum wakefield as a function of the distance behind the source particle. The minimum wakefield increases when the resonant frequency approaches the waveguide cutoff. The results agree very well with computer simulation on a real cavity-waveguide system

  14. Protocol for the verification of minimum criteria

    International Nuclear Information System (INIS)

    Gaggiano, M.; Spiccia, P.; Gaetano Arnetta, P.

    2014-01-01

    This Protocol has been prepared with reference to the provisions of article 8 of the Legislative Decree of May 26, 2000 No. 187. Quality controls of radiological equipment fit within the larger 'quality assurance Program' and are intended to ensure the correct operation of the same and the maintenance of that State. The pursuit of this objective guarantees that the radiological equipment subjected to those controls also meets the minimum criteria of acceptability set out in annex V of the aforementioned legislative decree establishing the conditions necessary to allow the functions to which each radiological equipment was designed, built and for which it is used. The Protocol is established for the purpose of quality control of radiological equipment of Cone Beam Computer Tomography type and reference document, in the sense that compliance with stated tolerances also ensures the subsistence minimum acceptability requirements, where applicable.

  15. Low Streamflow Forcasting using Minimum Relative Entropy

    Science.gov (United States)

    Cui, H.; Singh, V. P.

    2013-12-01

    Minimum relative entropy spectral analysis is derived in this study, and applied to forecast streamflow time series. Proposed method extends the autocorrelation in the manner that the relative entropy of underlying process is minimized so that time series data can be forecasted. Different prior estimation, such as uniform, exponential and Gaussian assumption, is taken to estimate the spectral density depending on the autocorrelation structure. Seasonal and nonseasonal low streamflow series obtained from Colorado River (Texas) under draught condition is successfully forecasted using proposed method. Minimum relative entropy determines spectral of low streamflow series with higher resolution than conventional method. Forecasted streamflow is compared to the prediction using Burg's maximum entropy spectral analysis (MESA) and Configurational entropy. The advantage and disadvantage of each method in forecasting low streamflow is discussed.

  16. Electroactive polymers for sensing

    Science.gov (United States)

    2016-01-01

    Electromechanical coupling in electroactive polymers (EAPs) has been widely applied for actuation and is also being increasingly investigated for sensing chemical and mechanical stimuli. EAPs are a unique class of materials, with low-moduli high-strain capabilities and the ability to conform to surfaces of different shapes. These features make them attractive for applications such as wearable sensors and interfacing with soft tissues. Here, we review the major types of EAPs and their sensing mechanisms. These are divided into two classes depending on the main type of charge carrier: ionic EAPs (such as conducting polymers and ionic polymer–metal composites) and electronic EAPs (such as dielectric elastomers, liquid-crystal polymers and piezoelectric polymers). This review is intended to serve as an introduction to the mechanisms of these materials and as a first step in material selection for both researchers and designers of flexible/bendable devices, biocompatible sensors or even robotic tactile sensing units. PMID:27499846

  17. Superabsorbent polymer; Kokyushusei porima

    Energy Technology Data Exchange (ETDEWEB)

    Fujita, M. [Sanyo Kasei Kogyo K.K., Tokyo (Japan)

    1996-07-20

    Superabsorbent polymer (SAP) which has the absorbing ability from several hundreds to thousand times of the dead weight possesses many other functions in addition to the absorbing function, and studies on its application to various fields have been carried on very actively. Particularly, about 90% of the demand is for the application to body fluid absorber in the fields of sanitary materials. Basic water absorption mechanism, kinds, production methods, special features and applied cases of superabsorbent polymer are introduced. SAP is structured by loosely bridged water soluble polymer, particularly polymer electrolyte, to provide water unsoluble and water swelling properties. The kinds and production methods of SAP are described. SAP has respiration property in addition to the high water absorbing power and water holding ability. It has carboxyl ions, and has ammonia absorption ability and polyvalent metal ion adsorption ability. Paper diapers, water holding materials for soil, and cold reserving materials are discussed as examples of SAP application. 3 refs., 2 figs., 1 tab.

  18. Rheology of Supramolecular Polymers

    DEFF Research Database (Denmark)

    Shabbir, Aamir

    Supramolecular polymers are a broad class of materials that include all polymerscapable of associating via secondary interactions. These materials represent an emerging class of systems with superior versatility compared to classical polymers with applications in food stuff, coatings, cost...... efficient processes or biomedical areas. Design and development of supramolecular polymers using ionic, hydrogen bonding or transition metal complexes with tailored properties requires deep understanding of dynamics both in linear and non-linear deformations. While linear rheology is important to understand...... the dynamics under equilibrium conditions, extensional rheology is relevant during the processing or in the usage of polymers utilizing supramolecular associations for example, acrylic based pressure sensitive adhesives are subjected to extensional deformations during the peeling where strain hardening...

  19. Piezoelectricity in polymers

    International Nuclear Information System (INIS)

    Kepler, R.G.; Anderson, R.A.

    1980-01-01

    Piezoelectricity and related properties of polymers are reviewed. After presenting a historical overview of the field, the mathematical basis of piezo- and pyroelectricity is summarized. We show how the experimentally measured quantities are related to the changes in polarization and point out the serious inequlity between direct and converse piezoelectric coefficients in polymers. Theoretical models of the various origins of piezo- and pyroelectricity, which include piezoelectricity due to inhomogeneous material properties and strains, are reviewed. Relaxational effects are also considered. Experimental techniques are examined and the results for different materials are presented. Because of the considerable work in recent years polyimylidene fluoride, this polymer receives the majority of the attention. The numerous applications of piezo-and pyroelectric polymers are mentioned. This article concludes with a discussion of the possible role of piezo- and pyroelectricity in biological system

  20. Conjugated Polymer Solar Cells

    National Research Council Canada - National Science Library

    Paraschuk, Dmitry Y

    2006-01-01

    This report results from a contract tasking Moscow State University as follows: Conjugated polymers are promising materials for many photonics applications, in particular, for photovoltaic and solar cell devices...

  1. Polymers for Protein Conjugation

    Directory of Open Access Journals (Sweden)

    Gianfranco Pasut

    2014-01-01

    Full Text Available Polyethylene glycol (PEG at the moment is considered the leading polymer for protein conjugation in view of its unique properties, as well as to its low toxicity in humans, qualities which have been confirmed by its extensive use in clinical practice. Other polymers that are safe, biodegradable and custom-designed have, nevertheless, also been investigated as potential candidates for protein conjugation. This review will focus on natural polymers and synthetic linear polymers that have been used for protein delivery and the results associated with their use. Genetic fusion approaches for the preparation of protein-polypeptide conjugates will be also reviewed and compared with the best known chemical conjugation ones.

  2. Reactive polymer fused deposition manufacturing

    Science.gov (United States)

    Kunc, Vlastimil; Rios, Orlando; Love, Lonnie J.; Duty, Chad E.; Johs, Alexander

    2017-05-16

    Methods and compositions for additive manufacturing that include reactive or thermosetting polymers, such as urethanes and epoxies. The polymers are melted, partially cross-linked prior to the depositing, deposited to form a component object, solidified, and fully cross-linked. These polymers form networks of chemical bonds that span the deposited layers. Application of a directional electromagnetic field can be applied to aromatic polymers after deposition to align the polymers for improved bonding between the deposited layers.

  3. Minimum Wage Laws and the Distribution of Employment.

    Science.gov (United States)

    Lang, Kevin

    The desirability of raising the minimum wage long revolved around just one question: the effect of higher minimum wages on the overall level of employment. An even more critical effect of the minimum wage rests on the composition of employment--who gets the minimum wage job. An examination of employment in eating and drinking establishments…

  4. Minimum intervention dentistry: periodontics and implant dentistry.

    Science.gov (United States)

    Darby, I B; Ngo, L

    2013-06-01

    This article will look at the role of minimum intervention dentistry in the management of periodontal disease. It will discuss the role of appropriate assessment, treatment and risk factors/indicators. In addition, the role of the patient and early intervention in the continuing care of dental implants will be discussed as well as the management of peri-implant disease. © 2013 Australian Dental Association.

  5. Minimum quality standards and international trade

    DEFF Research Database (Denmark)

    Baltzer, Kenneth Thomas

    2011-01-01

    This paper investigates the impact of a non-discriminating minimum quality standard (MQS) on trade and welfare when the market is characterized by imperfect competition and asymmetric information. A simple partial equilibrium model of an international Cournot duopoly is presented in which a domes...... prefer different levels of regulation. As a result, international trade disputes are likely to arise even when regulation is non-discriminating....

  6. ''Reduced'' magnetohydrodynamics and minimum dissipation rates

    International Nuclear Information System (INIS)

    Montgomery, D.

    1992-01-01

    It is demonstrated that all solutions of the equations of ''reduced'' magnetohydrodynamics approach a uniform-current, zero-flow state for long times, given a constant wall electric field, uniform scalar viscosity and resistivity, and uniform mass density. This state is the state of minimum energy dissipation rate for these boundary conditions. No steady-state turbulence is possible. The result contrasts sharply with results for full three-dimensional magnetohydrodynamics before the reduction occurs

  7. Minimum K_2,3-saturated Graphs

    OpenAIRE

    Chen, Ya-Chen

    2010-01-01

    A graph is K_{2,3}-saturated if it has no subgraph isomorphic to K_{2,3}, but does contain a K_{2,3} after the addition of any new edge. We prove that the minimum number of edges in a K_{2,3}-saturated graph on n >= 5 vertices is sat(n, K_{2,3}) = 2n - 3.

  8. Minimum degree and density of binary sequences

    DEFF Research Database (Denmark)

    Brandt, Stephan; Müttel, J.; Rautenbach, D.

    2010-01-01

    For d,k∈N with k ≤ 2d, let g(d,k) denote the infimum density of binary sequences (x)∈{0,1} which satisfy the minimum degree condition σ(x+) ≥ k for all i∈Z with xi=1. We reduce the problem of computing g(d,k) to a combinatorial problem related to the generalized k-girth of a graph G which...

  9. Radiation treated propylene polymers

    International Nuclear Information System (INIS)

    Hoffman, W.A. III; Baum, G.A.

    1982-01-01

    A method is provided for imparting improved strength and discoloration resistance to a stabilized propylene polymer that is to be exposed to a sterilizing dose of radiation. From 200 to 400 ppm of a phenolic antioxidant containing an isocyanurate group in its molecular structure, and a thiosynergist in an amount at least 6 times the weight of the antioxidant, are incorporated into the polymer before irradiation

  10. Interfaced conducting polymers

    Czech Academy of Sciences Publication Activity Database

    Stejskal, Jaroslav; Bober, Patrycja; Trchová, Miroslava; Nuzhnyy, Dmitry; Bovtun, Viktor; Savinov, Maxim; Petzelt, Jan; Prokeš, J.

    2017-01-01

    Roč. 224, February (2017), s. 109-115 ISSN 0379-6779 R&D Projects: GA ČR(CZ) GA16-02787S Institutional support: RVO:61389013 ; RVO:68378271 Keywords : polyaniline * polypyrrole * poly(p-phenylenediamine) Subject RIV: CD - Macromolecular Chemistry; CD - Macromolecular Chemistry (FZU-D) OBOR OECD: Polymer science; Polymer science (FZU-D) Impact factor: 2.435, year: 2016

  11. Sulfur polymer cement concrete

    International Nuclear Information System (INIS)

    Weber, H.H.; McBee, W.C.

    1990-01-01

    Sulfur-based composite materials formulated using sulfur polymer cement (SPC) and mineral aggregates are described and compared with conventional portland cement based materials. Materials characteristics presented include mechanical strength, chemical resistance, impact resistance, moisture permeation, and linear shrinkage during placement and curing. Examples of preparation and placement of sulfur polymer cement concrete (SC) are described using commercial scale equipment. SC applications presented are focused into hostile chemical environments where severe portland cement concrete (PCC) failure has occurred

  12. Radiation chemistry of polymers

    International Nuclear Information System (INIS)

    Charlesby, A.

    1987-01-01

    There are several and quite distinct major fields of interest discussed in this paper. The first deals with the modification of existing polymers either by main-chain scission or by cross-linking; the theories of these patterns of behavior are summarized here, and typical examples of polymers that show these alternative reactions are given. These are not comprehensive to avoid this presentation becoming a catalog of similar patterns of behavior

  13. Conjugated Polymers and Oligomers: Structural and Soft Matter Aspects

    DEFF Research Database (Denmark)

    This book identifies modern topics and current trends of structural and soft matter aspects of conjugated polymers and oligomers. Each chapter recognizes an active research line where structural perspective dominates research and therefore the book covers fundamental aspects of persistent...

  14. Plasticisation and complexation of certain polymers in supercritical CO2

    CSIR Research Space (South Africa)

    Labuschagne, Philip W

    2004-09-01

    Full Text Available A polymer system (polyvinylpyrrolidone + polyvinyl acetate-co-crotonic acid) was successfully identified for use as encapsulation material for sensitive actives using supercritical CO2 as plasticisation medium, having the following properties: 1...

  15. Preparing for the data revolution: identifying minimum health information competencies among the health workforce

    OpenAIRE

    Whittaker, Maxine; Hodge, Nicola; Mares, Renata E; Rodney, Anna

    2015-01-01

    Background Health information is required for a variety of purposes at all levels of a health system, and a workforce skilled in collecting, analysing, presenting, and disseminating such information is essential to fulfil these demands. While it is established that low- and middle-income countries (LMICs) are facing shortages in human resources for health (HRH), there has been little systematic attention focussed on non-clinical competencies. In response, we developed a framework that defines...

  16. Do minimum wages improve early life health? Evidence from developing countries.

    Science.gov (United States)

    Majid, Muhammad Farhan; Mendoza Rodríguez, José M; Harper, Sam; Frank, John; Nandi, Arijit

    2016-06-01

    The impact of legislated minimum wages on the early-life health of children living in low and middle-income countries has not been examined. For our analyses, we used data from the Demographic and Household Surveys (DHS) from 57 countries conducted between 1999 and 2013. Our analyses focus on height-for-age z scores (HAZ) for children under 5 years of age who were surveyed as part of the DHS. To identify the causal effect of minimum wages, we utilized plausibly exogenous variation in the legislated minimum wages during each child's year of birth, the identifying assumption being that mothers do not time their births around changes in the minimum wage. As a sensitivity exercise, we also made within family comparisons (mother fixed effect models). Our final analysis on 49 countries reveal that a 1% increase in minimum wages was associated with 0.1% (95% CI = -0.2, 0) decrease in HAZ scores. Adverse effects of an increase in the minimum wage were observed among girls and for children of fathers who were less than 35 years old, mothers aged 20-29, parents who were married, parents who were less educated, and parents involved in manual work. We also explored heterogeneity by region and GDP per capita at baseline (1999). Adverse effects were concentrated in lower-income countries and were most pronounced in South Asia. By contrast, increases in the minimum wage improved children's HAZ in Latin America, and among children of parents working in a skilled sector. Our findings are inconsistent with the hypothesis that increases in the minimum wage unconditionally improve child health in lower-income countries, and highlight heterogeneity in the impact of minimum wages around the globe. Future work should involve country and occupation specific studies which can explore not only different outcomes such as infant mortality rates, but also explore the role of parental investments in shaping these effects. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Performance Modification of Asphalt Binders using Thermoplastic Polymers

    Directory of Open Access Journals (Sweden)

    H. I. Al-Abdul Wahhab

    2004-12-01

    Full Text Available There is a need to improve the performance of asphalt binders to minimize stress cracking that occurs at low temperatures and plastic deformation at high temperatures. Importation of used asphalt-polymers from abroad, leads to an increase in the total construction cost as compared to the cost if the used polymers were of local origin. The main objective of this research was to modify locally produced asphalt. Ten polymers were identified as potential asphalt modifiers based on their physical properties and chemical composition. After preliminary laboratory evaluation for the melting point of these polymers, five polymers were selected for local asphalt modification. In the initial stage, required mixing time was decided based on the relation between shear loss modulus and mixing time .The optimum polymer content was selected based on Superpave binder performance grade specifications.The suitability of improvement was verified through the evaluation of permanent deformation and fatigue behavior of laboratory prepared asphalt concrete mixes. The results indicated that the rheological properties of the modified binders improved significantly with sufficient polymer content (3%. The aging properties of the modified binders were found to be dependent on the type of polymer.The fatigue life and resistance to permanent deformation were significantly improved due to enhanced binder rheological properties.  Thus, local asphalts can be modified using thermoplastic polymers.

  18. Precursor polymer compositions comprising polybenzimidazole

    Science.gov (United States)

    Klaehn, John R.; Peterson, Eric S.; Orme, Christopher J.

    2015-07-14

    Stable, high performance polymer compositions including polybenzimidazole (PBI) and a melamine-formaldehyde polymer, such as methylated, poly(melamine-co-formaldehyde), for forming structures such as films, fibers and bulky structures. The polymer compositions may be formed by combining polybenzimidazole with the melamine-formaldehyde polymer to form a precursor. The polybenzimidazole may be reacted and/or intertwined with the melamine-formaldehyde polymer to form the polymer composition. For example, a stable, free-standing film having a thickness of, for example, between about 5 .mu.m and about 30 .mu.m may be formed from the polymer composition. Such films may be used as gas separation membranes and may be submerged into water for extended periods without crazing and cracking. The polymer composition may also be used as a coating on substrates, such as metal and ceramics, or may be used for spinning fibers. Precursors for forming such polymer compositions are also disclosed.

  19. Hierarchical Fiber Structures Made by Electrospinning Polymers

    Science.gov (United States)

    Reneker, Darrell H.

    2009-03-01

    A filter for water purification that is very thin, with small interstices and high surface area per unit mass, can be made with nanofibers. The mechanical strength of a very thin sheet of nanofibers is not great enough to withstand the pressure drop of the fluid flowing through. If the sheet of nanofibers is made thicker, the strength will increase, but the flow will be reduced to an impractical level. An optimized filter can be made with nanometer scale structures supported on micron scale structures, which are in turn supported on millimeter scale structures. This leads to a durable hierarchical structure to optimize the filtration efficiency with a minimum amount of material. Buckling coils,ootnotetextTao Han, Darrell H Reneker, Alexander L. Yarin, Polymer, Volume 48, issue 20 (September 21, 2007), p. 6064-6076. electrical bending coilsootnotetextDarrell H. Reneker and Alexander L. Yarin, Polymer, Volume 49, Issue 10 (2008) Pages 2387-2425, DOI:10.1016/j.polymer.2008.02.002. Feature Article. and pendulum coilsootnotetextT. Han, D.H. Reneker, A.L. Yarin, Polymer, Volume 49, (2008) Pages 2160-2169, doi:10.1016/jpolymer.2008.01.0487878. spanning dimensions from a few microns to a few centimeters can be collected from a single jet by controlling the position and motion of a collector. Attractive routes to the design and construction of hierarchical structures for filtration are based on nanofibers supported on small coils that are in turn supported on larger coils, which are supported on even larger overlapping coils. ``Such top-down'' hierarchical structures are easy to make by electrospinning. In one example, a thin hierarchical structure was made, with a high surface area and small interstices, having an open area of over 50%, with the thinnest fibers supported at least every 15 microns.

  20. Decentralized Pricing in Minimum Cost Spanning Trees

    DEFF Research Database (Denmark)

    Hougaard, Jens Leth; Moulin, Hervé; Østerdal, Lars Peter

    In the minimum cost spanning tree model we consider decentralized pricing rules, i.e. rules that cover at least the ecient cost while the price charged to each user only depends upon his own connection costs. We de ne a canonical pricing rule and provide two axiomatic characterizations. First......, the canonical pricing rule is the smallest among those that improve upon the Stand Alone bound, and are either superadditive or piece-wise linear in connection costs. Our second, direct characterization relies on two simple properties highlighting the special role of the source cost....

  1. The Risk Management of Minimum Return Guarantees

    Directory of Open Access Journals (Sweden)

    Antje Mahayni

    2008-05-01

    Full Text Available Contracts paying a guaranteed minimum rate of return and a fraction of a positive excess rate, which is specified relative to a benchmark portfolio, are closely related to unit-linked life-insurance products and can be considered as alternatives to direct investment in the underlying benchmark. They contain an embedded power option, and the key issue is the tractable and realistic hedging of this option, in order to rigorously justify valuation by arbitrage arguments and prevent the guarantees from becoming uncontrollable liabilities to the issuer. We show how to determine the contract parameters conservatively and implement robust risk-management strategies.

  2. Iterative Regularization with Minimum-Residual Methods

    DEFF Research Database (Denmark)

    Jensen, Toke Koldborg; Hansen, Per Christian

    2007-01-01

    subspaces. We provide a combination of theory and numerical examples, and our analysis confirms the experience that MINRES and MR-II can work as general regularization methods. We also demonstrate theoretically and experimentally that the same is not true, in general, for GMRES and RRGMRES their success......We study the regularization properties of iterative minimum-residual methods applied to discrete ill-posed problems. In these methods, the projection onto the underlying Krylov subspace acts as a regularizer, and the emphasis of this work is on the role played by the basis vectors of these Krylov...... as regularization methods is highly problem dependent....

  3. Iterative regularization with minimum-residual methods

    DEFF Research Database (Denmark)

    Jensen, Toke Koldborg; Hansen, Per Christian

    2006-01-01

    subspaces. We provide a combination of theory and numerical examples, and our analysis confirms the experience that MINRES and MR-II can work as general regularization methods. We also demonstrate theoretically and experimentally that the same is not true, in general, for GMRES and RRGMRES - their success......We study the regularization properties of iterative minimum-residual methods applied to discrete ill-posed problems. In these methods, the projection onto the underlying Krylov subspace acts as a regularizer, and the emphasis of this work is on the role played by the basis vectors of these Krylov...... as regularization methods is highly problem dependent....

  4. Polymer gel dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Baldock, C [Institute of Medical Physics, School of Physics, University of Sydney (Australia); De Deene, Y [Radiotherapy and Nuclear Medicine, Ghent University Hospital (Belgium); Doran, S [CRUK Clinical Magnetic Resonance Research Group, Institute of Cancer Research, Surrey (United Kingdom); Ibbott, G [Radiation Physics, UT M D Anderson Cancer Center, Houston, TX (United States); Jirasek, A [Department of Physics and Astronomy, University of Victoria, Victoria, BC (Canada); Lepage, M [Centre d' imagerie moleculaire de Sherbrooke, Departement de medecine nucleaire et de radiobiologie, Universite de Sherbrooke, Sherbrooke, QC (Canada); McAuley, K B [Department of Chemical Engineering, Queen' s University, Kingston, ON (Canada); Oldham, M [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States); Schreiner, L J [Cancer Centre of South Eastern Ontario, Kingston, ON (Canada)], E-mail: c.baldock@physics.usyd.edu.au, E-mail: yves.dedeene@ugent.be

    2010-03-07

    Polymer gel dosimeters are fabricated from radiation sensitive chemicals which, upon irradiation, polymerize as a function of the absorbed radiation dose. These gel dosimeters, with the capacity to uniquely record the radiation dose distribution in three-dimensions (3D), have specific advantages when compared to one-dimensional dosimeters, such as ion chambers, and two-dimensional dosimeters, such as film. These advantages are particularly significant in dosimetry situations where steep dose gradients exist such as in intensity-modulated radiation therapy (IMRT) and stereotactic radiosurgery. Polymer gel dosimeters also have specific advantages for brachytherapy dosimetry. Potential dosimetry applications include those for low-energy x-rays, high-linear energy transfer (LET) and proton therapy, radionuclide and boron capture neutron therapy dosimetries. These 3D dosimeters are radiologically soft-tissue equivalent with properties that may be modified depending on the application. The 3D radiation dose distribution in polymer gel dosimeters may be imaged using magnetic resonance imaging (MRI), optical-computerized tomography (optical-CT), x-ray CT or ultrasound. The fundamental science underpinning polymer gel dosimetry is reviewed along with the various evaluation techniques. Clinical dosimetry applications of polymer gel dosimetry are also presented. (topical review)

  5. Polymer Directed Protein Assemblies

    Directory of Open Access Journals (Sweden)

    Patrick van Rijn

    2013-05-01

    Full Text Available Protein aggregation and protein self-assembly is an important occurrence in natural systems, and is in some form or other dictated by biopolymers. Very obvious influences of biopolymers on protein assemblies are, e.g., virus particles. Viruses are a multi-protein assembly of which the morphology is dictated by poly-nucleotides namely RNA or DNA. This “biopolymer” directs the proteins and imposes limitations on the structure like the length or diameter of the particle. Not only do these bionanoparticles use polymer-directed self-assembly, also processes like amyloid formation are in a way a result of directed protein assembly by partial unfolded/misfolded biopolymers namely, polypeptides. The combination of proteins and synthetic polymers, inspired by the natural processes, are therefore regarded as a highly promising area of research. Directed protein assembly is versatile with respect to the possible interactions which brings together the protein and polymer, e.g., electrostatic, v.d. Waals forces or covalent conjugation, and possible combinations are numerous due to the large amounts of different polymers and proteins available. The protein-polymer interacting behavior and overall morphology is envisioned to aid in clarifying protein-protein interactions and are thought to entail some interesting new functions and properties which will ultimately lead to novel bio-hybrid materials.

  6. Supercritical transitiometry of polymers.

    Science.gov (United States)

    Randzio, S L; Grolier, J P

    1998-06-01

    Employing supercritical fluids (SCFs) during polymers processing allows the unusual properties of SCFs to be exploited for making polymer products that cannot be obtained by other means. A new supercritical transitiometer has been constructed to permit study of the interactions of SCFs with polymers during processing under well-defined conditions of temperature and pressure. The supercritical transitiometer allows pressure to be exerted by either a supercritical fluid or a neutral medium and enables simultaneous determination of four basic parameters of a transition, i.e., p, T, Δ(tr)H and Δ(tr)V. This permits determination of the SCF effect on modification of the polymer structure at a given pressure and temperature and defines conditions to allow reproducible preparation of new polymer structures. Study of a semicrystalline polyethylene by this method has defined conditions for preparation of new microfoamed phases with good mechanical properties. The low densities and microporous structures of the new materials may make them useful for applications in medicine, pharmacy, or the food industry, for example.

  7. Multifunctional Polymer Nanocomposites

    Science.gov (United States)

    Galaska, Alexandra Maria; Song, Haixiang; Guo, Zhanhu

    With more awareness of energy conversion/storage and saving, different strategies have been developed to utilize the sustainable and renewable energy. Introducing nanoscale fillers can make inert polymer matrix possess unique properties to satisfy certain functions. For example, alumina nanoparticles have strengthened the weak thermosetting polymers. A combined mixture of carbon nanofibers and magnetite nanoparticles have made the inert epoxy sensitive for magnetic field for sensing applications. Introducing silica nanoparticles into conductive polymers such as polyaniline has enhanced the giant magnetoresistance behaviors. The introduced nanoparticles have made the transparent polymer have the electromagnetic interference (EMI) shielding function while reduce the density significantly. With the desired miniaturization, the materials combining different functionalities have become importantly interesting. In this talk, methodologies to prepare nanocomposites and their effects on the produced nanocomposites will be discussed. A variety of advanced polymer nanocomposites will be introduced. Unique properties including mechanical, electrical, magnetoresistance etc. and the applications for environmental remediation, energy storage/saving, fire retardancy, electromagnetic interference shielding, and electronic devices will be presented.

  8. Laser Welding Analysis for 3D Printed Thermoplastic and Poly-acetate Polymers

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Hae Woon; Yun, Sung Chul [Keimyung University, Daegu (Korea, Republic of)

    2015-07-15

    In this study, experimental and computer simulation results are compared and analyzed. Three-dimensional (3D) fabricated matrices from an MJM 3D printer were joined with poly-acetate thermoplastic polymers using a diode laser. A power range of 5-7 W was used to irradiate the boundary of two polymers. The heated polymers flowed into the matrices of the 3D fabricated structure, and reliable mechanical joining was achieved. Computer simulation showed the temperature distribution in the polymers, and flow direction was estimated based on the flux and temperature information. It was found that the more than the minimum energy threshold was required to effectively join the polymers and that two scans at low-speed were more effective than four scans at high speed.

  9. Laser Welding Analysis for 3D Printed Thermoplastic and Poly-acetate Polymers

    International Nuclear Information System (INIS)

    Choi, Hae Woon; Yun, Sung Chul

    2015-01-01

    In this study, experimental and computer simulation results are compared and analyzed. Three-dimensional (3D) fabricated matrices from an MJM 3D printer were joined with poly-acetate thermoplastic polymers using a diode laser. A power range of 5-7 W was used to irradiate the boundary of two polymers. The heated polymers flowed into the matrices of the 3D fabricated structure, and reliable mechanical joining was achieved. Computer simulation showed the temperature distribution in the polymers, and flow direction was estimated based on the flux and temperature information. It was found that the more than the minimum energy threshold was required to effectively join the polymers and that two scans at low-speed were more effective than four scans at high speed

  10. Business, market and intellectual property analysis of polymer solar cells

    DEFF Research Database (Denmark)

    Damgaard Nielsen, Torben; Cruickshank, C.; Foged, S.

    2010-01-01

    and manufacturing cost leaves little room for competition on the thin film photovoltaic market. However, polymer solar cells do enable the competitive manufacture of low cost niche products and is viewed as financially viable in its currently available form in a large volume approximation. Finally, it is found......The business potential of polymer solar cells is reviewed and the market opportunities analyzed on the basis of the currently reported and projected performance and manufacturing cost of polymer solar cells. Possible new market areas are identified and described. An overview of the present patent...... and intellectual property situation is also given and a patent map of polymer solar cells is drawn in a European context. It is found that the business potential of polymer solar cells is large when taking the projections for future performance into account while the currently available performance...

  11. Feedback brake distribution control for minimum pitch

    Science.gov (United States)

    Tavernini, Davide; Velenis, Efstathios; Longo, Stefano

    2017-06-01

    The distribution of brake forces between front and rear axles of a vehicle is typically specified such that the same level of brake force coefficient is imposed at both front and rear wheels. This condition is known as 'ideal' distribution and it is required to deliver the maximum vehicle deceleration and minimum braking distance. For subcritical braking conditions, the deceleration demand may be delivered by different distributions between front and rear braking forces. In this research we show how to obtain the optimal distribution which minimises the pitch angle of a vehicle and hence enhances driver subjective feel during braking. A vehicle model including suspension geometry features is adopted. The problem of the minimum pitch brake distribution for a varying deceleration level demand is solved by means of a model predictive control (MPC) technique. To address the problem of the undesirable pitch rebound caused by a full-stop of the vehicle, a second controller is designed and implemented independently from the braking distribution in use. An extended Kalman filter is designed for state estimation and implemented in a high fidelity environment together with the MPC strategy. The proposed solution is compared with the reference 'ideal' distribution as well as another previous feed-forward solution.

  12. Flame spraying of polymers

    International Nuclear Information System (INIS)

    Varacalle, D.J. Jr.; Zeek, D.P.; Couch, K.W.; Benson, D.M.; Kirk, S.M.

    1997-01-01

    Statistical design-of-experiment studies of the thermal spraying of polymer powders are presented. Studies of the subsonic combustion (i.e., Flame) process were conducted in order to determine the quality and economics of polyester and urethane coatings. Thermally sprayed polymer coatings are of interest to several industries for anticorrosion applications, including the chemical, automotive, and aircraft industries. In this study, the coating design has been optimized for a site-specific application using Taguchi-type fractional-factorial experiments. Optimized coating designs are presented for the two powder systems. A substantial range of thermal processing conditions and their effect on the resultant polymer coatings is presented. The coatings were characterized by optical metallography, hardness testing, tensile testing, and compositional analysis. Characterization of the coatings yielded the thickness, bond strength, Knoop microhardness, roughness, deposition efficiency, and porosity. Confirmation testing was accomplished to verify the coating designs

  13. Nanostructured silicate polymer concrete

    Directory of Open Access Journals (Sweden)

    Figovskiy Oleg L'vovich

    2014-03-01

    Full Text Available It has been known that acid-resistant concretes on the liquid glass basis have high porosity (up to 18~20 %, low strength and insufficient water resistance. Significant increasing of silicate matrix strength and density was carried out by incorporation of special liquid organic alkali-soluble silicate additives, which block superficial pores and reduce concrete shrinkage deformation. It was demonstrated that introduction of tetrafurfuryloxisilane additive sharply increases strength, durability and shock resistance of silicate polymer concrete in aggressive media. The experiments showed, that the strength and density of silicate polymer concrete increase in case of decreasing liquid glass content. The authors obtained optimal content of silicate polymer concrete, which possesses increased strength, durability, density and crack-resistance. Diffusive permeability of concrete and its chemical resistance has been investigated in various corroding media.

  14. Semi-metallic polymers

    DEFF Research Database (Denmark)

    Bubnova, Olga; Khan, Zia Ullah; Wang, Hui

    2014-01-01

    Polymers are lightweight, flexible, solution-processable materials that are promising for low-cost printed electronics as well as for mass-produced and large-area applications. Previous studies demonstrated that they can possess insulating, semiconducting or metallic properties; here we report...... that polymers can also be semi-metallic. Semi-metals, exemplified by bismuth, graphite and telluride alloys, have no energy bandgap and a very low density of states at the Fermi level. Furthermore, they typically have a higher Seebeck coefficient and lower thermal conductivities compared with metals, thus being...... a Fermi glass to a semi-metal. The high Seebeck value, the metallic conductivity at room temperature and the absence of unpaired electron spins makes polymer semi-metals attractive for thermoelectrics and spintronics....

  15. 'Stuffed' conducting polymers

    DEFF Research Database (Denmark)

    Winther-Jensen, Bjørn; Chen, Jun; West, Keld

    2005-01-01

    Conducting polymers (CP) obtained by oxidative polymerization using iron(III) salts shrink when Fe(II) and the excess counter ions are washed out after polymerization. This phenomenon can be used to incorporate active molecules into the CP matrix via their addition to the wash liquid. In the pres......Conducting polymers (CP) obtained by oxidative polymerization using iron(III) salts shrink when Fe(II) and the excess counter ions are washed out after polymerization. This phenomenon can be used to incorporate active molecules into the CP matrix via their addition to the wash liquid....... In the present work we demonstrate this principle on three different CP's: polypyrrole (PPy), poly-terthiophene (PTTh) and poly(3,4-ethylenedioxy thiophene) (PEDT), using ferrocene as a model molecule to be trapped in the polymer films. (c) 2005 Elsevier Ltd. All rights reserved....

  16. Electric field induced dewetting at polymer/polymer interfaces

    NARCIS (Netherlands)

    Lin, Z.Q.; Kerle, T.; Russell, T.P.; Schäffer, E.; Steiner, U

    2002-01-01

    External electric fields were used to amplify interfacial fluctuations in the air/polymer/polymer system where one polymer dewets the other. Two different hydrodynamic regimes were found as a function of electric field strength. If heterogeneous nucleation leads to the formation of holes before the

  17. Polymer containing functional end groups is base for new polymers

    Science.gov (United States)

    Hirshfield, S. M.

    1971-01-01

    Butadiene is polymerized with lithium-p-lithiophenoxide to produce linear polymer containing oxy-lithium group at one end and active carbon-lithium group at other end. Living polymers represent new approach to preparation of difunctional polymers in which structural features, molecular weight, type and number of end groups are controlled.

  18. Raw and renewable polymers

    CSIR Research Space (South Africa)

    Joseph, S

    2010-01-01

    Full Text Available in the permeability of the membrane and HO H3C H3C H2C H2C HO OH NH NH OH O OC C n O O O O Fig. 4 Structure of Chitin Raw and Renewable Polymers promoting internal osmotic imbalances. This results in leaching of electrolytes and proteins. 2... is often lost. In most cases this denaturation is not reversible. R-CH-COOH NH2 w Amino acid H2N COOHR a Amino acid Fig. 5 Structure of amino acid Raw and Renewable Polymers The solubilities of proteins vary considerably based on compositions...

  19. Delocalization in polymer models

    CERN Document Server

    Jitomirskaya, S Yu; Stolz, G

    2003-01-01

    A polymer model is a one-dimensional Schroedinger operator composed of two finite building blocks. If the two associated transfer matrices commute, the corresponding energy is called critical. Such critical energies appear in physical models, an example being the widely studied random dimer model. Although the random models are known to have pure-point spectrum with exponentially localized eigenstates for almost every configuration of the polymers, the spreading of an initially localized wave packet is here proven to be at least diffusive for every configuration.

  20. Nanoparticles from Renewable Polymers

    Directory of Open Access Journals (Sweden)

    Frederik Roman Wurm

    2014-07-01

    Full Text Available The use of polymers from natural resources can bring many benefits for novel polymeric nanoparticle systems. Such polymers have a variety of beneficial properties such as biodegradability and biocompatibility, they are readily available on large scale and at low cost. As the amount of fossil fuels decrease, their application becomes more interesting even if characterization is in many cases more challenging due to structural complexity, either by broad distribution of their molecular weights polysaccharides, polyesters, lignin or by complex structure (proteins, lignin. This review summarizes different sources and methods for the preparation of biopolymer-based nanoparticle systems for various applications.

  1. Polymers at cryogenic temperatures

    CERN Document Server

    Fu, Shao-Yun

    2013-01-01

    Kalia and Fu's novel monograph covers cryogenic treatment, properties and applications of cryo-treated polymer materials. Written by numerous international experts, the twelve chapters in this book offer the reader a comprehensive picture of the latest findings and developments, as well as an outlook on the field. Cryogenic technology has seen remarkable progress in the past few years and especially cryogenic properties of polymers are attracting attention through new breakthroughs in space, superconducting, magnetic and electronic techniques. This book is a valuable resource for researchers, educators, engineers and graduate students in the field and at technical institutions.

  2. Polymers and colloids

    International Nuclear Information System (INIS)

    Schurtenberger, P.

    1996-01-01

    A wealth of structural information from colloid and polymer solutions on a large range of length scales can be obtained using small angle neutron scattering (SANS) experiments. After a general introduction to the field of soft condensed matter, I shall give a few selected examples on how SANS combined with suitable contrast variation schemes can be used to extract information on the size and conformation of polymer coils in solution and in the melt, and on the local structure and flexibility of polymerlike micelles and microemulsions. (author) 8 figs., tabs., 44 refs

  3. Polymers and colloids

    Energy Technology Data Exchange (ETDEWEB)

    Schurtenberger, P [ETH Zurich, Inst. fuer Polymere, Zurich (Switzerland)

    1996-11-01

    A wealth of structural information from colloid and polymer solutions on a large range of length scales can be obtained using small angle neutron scattering (SANS) experiments. After a general introduction to the field of soft condensed matter, I shall give a few selected examples on how SANS combined with suitable contrast variation schemes can be used to extract information on the size and conformation of polymer coils in solution and in the melt, and on the local structure and flexibility of polymerlike micelles and microemulsions. (author) 8 figs., tabs., 44 refs.

  4. Ballistic nanoindentation of polymers

    Science.gov (United States)

    Gotsmann, B.; Rothuizen, H.; Duerig, U.

    2008-09-01

    Indentation of a sharp (20 nm) cantilevered silicon tip into a polymer (SU8) surface is analyzed experimentally and through finite-element simulations. A rate effect on the microsecond scale that eases indentation is found, in contrast to the commonly observed hardening at high strain rates. The observed rate effect is discussed in terms of adiabatic heating and inertial force overshoot. The estimated magnitude of adiabatic heating is marginal, but the force overshoot itself is large enough to explain the data. The data imply that topographic patterning of a polymer at megahertz rates is feasible.

  5. Mechanically Invisible Polymer Coatings

    DEFF Research Database (Denmark)

    2014-01-01

    phase comprises particles, said particles comprising a filler material and an encapsulating coating of a second polymeric material, wherein the backbones of the first and second polymeric materials are the same. The composition may be used in electroactive polymers (EAPs) in order to obtain mechanically......The present invention relates to a composition comprising encapsulated particles in a polymeric material. The composition comprises a continuous phase and a discontinuous phase incorporated therein, wherein the continuous phase comprises a first polymeric material and wherein the discontinuous...... invisible polymer coatings....

  6. Antibacterial polymer coatings.

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, Mollye C.; Allen, Ashley N.; Barnhart, Meghan; Tucker, Mark David; Hibbs, Michael R.

    2009-09-01

    A series of poly(sulfone)s with quaternary ammonium groups and another series with aldehyde groups are synthesized and tested for biocidal activity against vegetative bacteria and spores, respectively. The polymers are sprayed onto substrates as coatings which are then exposed to aqueous suspensions of organisms. The coatings are inherently biocidal and do not release any agents into the environment. The coatings adhere well to both glass and CARC-coated coupons and they exhibit significant biotoxicity. The most effective quaternary ammonium polymers kills 99.9% of both gram negative and gram positive bacteria and the best aldehyde coating kills 81% of the spores on its surface.

  7. Polymer architecture and drug delivery.

    Science.gov (United States)

    Qiu, Li Yan; Bae, You Han

    2006-01-01

    Polymers occupy a major portion of materials used for controlled release formulations and drug-targeting systems because this class of materials presents seemingly endless diversity in topology and chemistry. This is a crucial advantage over other classes of materials to meet the ever-increasing requirements of new designs of drug delivery formulations. The polymer architecture (topology) describes the shape of a single polymer molecule. Every natural, seminatural, and synthetic polymer falls into one of categorized architectures: linear, graft, branched, cross-linked, block, star-shaped, and dendron/dendrimer topology. Although this topic spans a truly broad area in polymer science, this review introduces polymer architectures along with brief synthetic approaches for pharmaceutical scientists who are not familiar with polymer science, summarizes the characteristic properties of each architecture useful for drug delivery applications, and covers recent advances in drug delivery relevant to polymer architecture.

  8. Phylogenetic Applications of the Minimum Contradiction Approach on Continuous Characters

    Directory of Open Access Journals (Sweden)

    Marc Thuillard

    2009-01-01

    Full Text Available We describe the conditions under which a set of continuous variables or characters can be described as an X-tree or a split network. A distance matrix corresponds exactly to a split network or a valued X-tree if, after ordering of the taxa, the variables values can be embedded into a function with at most a local maximum and a local minimum, and crossing any horizontal line at most twice. In real applications, the order of the taxa best satisfying the above conditions can be obtained using the Minimum Contradiction method. This approach is applied to 2 sets of continuous characters. The first set corresponds to craniofacial landmarks in Hominids. The contradiction matrix is used to identify possible tree structures and some alternatives when they exist. We explain how to discover the main structuring characters in a tree. The second set consists of a sample of 100 galaxies. In that second example one shows how to discretize the continuous variables describing physical properties of the galaxies without disrupting the underlying tree structure.

  9. A proposal of comparative Maunder minimum cosmogenic isotope measurements

    International Nuclear Information System (INIS)

    Attolini, M.R.; Nanni, T.; Galli, M.; Povinec, P.

    1989-01-01

    There are at present contraddictory conclusions about solar activity and cosmogenic isotope production variation during Maunder Minimum. The interaction of solar wind with galactic cosmic rays, the dynamic behaviour of the Sun either as a system having an internal clock, and/or as a forced non linear system, are important aspects that can shed new light on solar physics, the Earth-Sun relationship and the climatic variation. An essential progress in the matter might be made by clarifying the cosmogenic isotope production during the mentioned interval. As it seems that during Maunder Minimum the Be10 production oscillates of about a factor of two, the authors have also to expect short scale enhanced variations in tree rings radiocarbon concentrations for the same interval. It is therefore highly desirable that for the same interval, that the authors would identify with 1640-1720 AD, detailed concentration measurements both of Be10 (in dated polar ice in addition to those of Beer et al.) and of tree ring radiocarbon, be made with cross-checking, in samples of different latitudes, longitudes and within short and large distance of the sea. The samples could be taken, as for example in samples from the central Mediterranean region, in the Baltic region and in other sites from central Europe and Asia

  10. Minimum thickness blanket-shield for fusion reactors

    International Nuclear Information System (INIS)

    Karni, Y.; Greenspan, E.

    1989-01-01

    A lower bound on the minimum thickness fusion reactor blankets can be designed to have, if they are to breed 1.267 tritons per fusion neutron, is identified by performing a systematic nucleonic optimization of over a dozen different blanket concepts which use either Be, Li 17 Pb 83 , W or Zr for neutron multiplication. It is found that Be offers minimum thickness blankets; that the blanket and shield (B/S) thickness of Li 17 Pb 83 based blankets which are supplemented by Li 2 O and/or TiH 2 are comparable to the thickness of Be based B/S; that of the Be based blankets, the aqueous self-cooled one offers one of the most compact B/S; and that a number of blanket concepts might enable the design of B/S which is approximately 12 cm and 39 cm thinner than the B/S thickness of, respectively, conventional self-cooled Li 17 Pb 83 and Li blankets. Aqueous self-cooled tungsten blankets could be useful for experimental fusion devices provided they are designed to be heterogeneous. (orig.)

  11. Shear Strength of Stabilized Kaolin Soil Using Liquid Polymer

    Science.gov (United States)

    Azhar, A. T. S.; Fazlina, M. I. S.; Nizam, Z. M.; Fairus, Y. M.; Hakimi, M. N. A.; Riduan, Y.; Faizal, P.

    2017-08-01

    The purpose of this research is to investigate the suitability of polymer in soil stabilization by examining its strength to withstand compressive strength. Throughout this research study, manufactured polymer was used as a chemical liquid soil stabilizer. The liquid polymer was diluted using a proposed dilution factor of 1 : 3 (1 part polymer: 3 parts distilled water) to preserve the workability of the polymer in kaolin mixture. A mold with a diameter of 50 mm and a height of 100 mm was prepared. Kaolin soil was mixed with different percentages of polymer from 10%, 15%, 20%, 25%, 30% and 35% of the mass of the kaolin clay sample. Kaolin mixtures were tested after a curing period of 3 days, 7 days, 14 days and 28 days respectively. The physical properties were determined by conducting a moisture content test and Atterberg limit test which comprise of liquid limit, plastic limit and shrinkage limit. Meanwhile, the mechanical properties of the soil shear strength were identified through an unconfined compressive strength (UCS) test. Stabilized kaolin soil showed the highest compressive strength value when it was mixed with 35% of polymer compared to other percentages that marked an increment in strength which are 45.72% (3 days), 67.57% (7 days), 81.73% (14 days) and 77.84% (28 days). Hence, the most effective percentage of liquid polymer which should be used to increase the strength of kaolin soil is 35%.

  12. Conducting polymer 3D microelectrodes

    DEFF Research Database (Denmark)

    Sasso, Luigi; Vazquez, Patricia; Vedarethinam, Indumathi

    2010-01-01

    Conducting polymer 3D microelectrodes have been fabricated for possible future neurological applications. A combination of micro-fabrication techniques and chemical polymerization methods has been used to create pillar electrodes in polyaniline and polypyrrole. The thin polymer films obtained...... showed uniformity and good adhesion to both horizontal and vertical surfaces. Electrodes in combination with metal/conducting polymer materials have been characterized by cyclic voltammetry and the presence of the conducting polymer film has shown to increase the electrochemical activity when compared...

  13. Shape memory polymer medical device

    Science.gov (United States)

    Maitland, Duncan [Pleasant Hill, CA; Benett, William J [Livermore, CA; Bearinger, Jane P [Livermore, CA; Wilson, Thomas S [San Leandro, CA; Small, IV, Ward; Schumann, Daniel L [Concord, CA; Jensen, Wayne A [Livermore, CA; Ortega, Jason M [Pacifica, CA; Marion, III, John E.; Loge, Jeffrey M [Stockton, CA

    2010-06-29

    A system for removing matter from a conduit. The system includes the steps of passing a transport vehicle and a shape memory polymer material through the conduit, transmitting energy to the shape memory polymer material for moving the shape memory polymer material from a first shape to a second and different shape, and withdrawing the transport vehicle and the shape memory polymer material through the conduit carrying the matter.

  14. Do minimum wages reduce poverty? Evidence from Central America ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2010-12-16

    Dec 16, 2010 ... Raising minimum wages has traditionally been considered a way to protect poor ... However, the effect of raising minimum wages remains an empirical question ... ​More than 70 of Vietnamese entrepreneurs choose to start a ...

  15. Frictional properties of confined polymers

    DEFF Research Database (Denmark)

    Sivebæk, Ion Marius; Samoilov, Vladimir N; Persson, Bo N J

    2008-01-01

    We present molecular dynamics friction calculations for confined hydrocarbon solids with molecular lengths from 20 to 1400 carbon atoms. Two cases are considered: a) polymer sliding against a hard substrate, and b) polymer sliding on polymer. In the first setup the shear stresses are relatively i...

  16. New polymers for phase partitioning

    Science.gov (United States)

    Harris, J. M.

    1981-01-01

    The synthesizing of several polyethylene glycols having crown ethers attached is reported. This work led to the identification of three new polymer types which promise to be more effective at selectively binding specific cell types. Work was completed on identification of chemical properties of the new polymer crowns and on development of new techniques for determination of polymer-phase composition.

  17. Nonlinear microstructured polymer optical fibres

    DEFF Research Database (Denmark)

    Frosz, Michael Henoch

    is potentially the case for microstructured polymer optical fibres (mPOFs). Another advantage is that polymer materials have a higher biocompatibility than silica, meaning that it is easier to bond certain types of biosensor materials to a polymer surface than to silica. As with silica PCFs, it is difficult...

  18. Reversible networks in supramolecular polymers

    NARCIS (Netherlands)

    Havermans - van Beek, D.J.M.

    2007-01-01

    Non–covalent interactions between low molecular weight polymers form the basis of supramolecular polymers. The material properties of such polymers are determined by the strength and lifetime of the non–covalent reversible interactions. Due to the reversibility of the interactions between the low

  19. Fullerene solubility-current density relationship in polymer solar cells

    International Nuclear Information System (INIS)

    Renz, Joachim A.; Gobsch, Gerhard; Hoppe, Harald; Troshin, Pavel A.; Razumov, V.F.

    2008-01-01

    During the last decade polymer solar cells have undergone a steady increase in overall device efficiency. To date, essential efficiency improvements of polymer-fullerene solar cells require the development of new materials. Whilst most research efforts aim at an improved or spectrally extended absorption of the donor polymer, not so much attention has been paid to the fullerene properties themselves. We have investigated a number of structurally related fullerenes, in order to study the relationship between chemical structure and resulting polymer-fullerene bulk heterojunction photovoltaic properties. Our study reveals a clear connection between the fullerene solubility as material property on one hand and the solar cells short circuit photocurrent on the other hand. The tendency of the less soluble fullerene derivates to aggregate was accounted for smaller current densities in the respective solar cells. Once a minimum solubility of approx. 25 mg/ml in chlorobenzene was overcome by the fullerene derivative, the short circuit current density reached a plateau, of about 8-10 mA/cm 2 . Thus the solubility of the fullerene derivative directly influences the blend morphology and displays an important parameter for efficient polymer-fullerene bulk heterojunction solar cell operation. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (Abstract Copyright [2008], Wiley Periodicals, Inc.)

  20. 30 CFR 56.19021 - Minimum rope strength.

    Science.gov (United States)

    2010-07-01

    ... feet: Minimum Value=Static Load×(7.0-0.001L) For rope lengths 3,000 feet or greater: Minimum Value=Static Load×4.0 (b) Friction drum ropes. For rope lengths less than 4,000 feet: Minimum Value=Static Load×(7.0-0.0005L) For rope lengths 4,000 feet or greater: Minimum Value=Static Load×5.0 (c) Tail ropes...

  1. Does increasing the minimum wage reduce poverty in developing countries?

    OpenAIRE

    Gindling, T. H.

    2014-01-01

    Do minimum wage policies reduce poverty in developing countries? It depends. Raising the minimum wage could increase or decrease poverty, depending on labor market characteristics. Minimum wages target formal sector workers—a minority of workers in most developing countries—many of whom do not live in poor households. Whether raising minimum wages reduces poverty depends not only on whether formal sector workers lose jobs as a result, but also on whether low-wage workers live in poor househol...

  2. White polymer light-emitting diode based on polymer blending

    International Nuclear Information System (INIS)

    Lee, Yong Kyun; Kwon, Soon Kab; Kim, Jun Young; Park, Tae Jin; Song, Dae Ho; Kwon, Jang Hyuk; Choo, Dong Jun; Jang, Jin; Jin, Jae Kyu; You, Hong

    2006-01-01

    A series of white polymer light emitting devices have been fabricated by using a polymer blending system of polyfluorene-based blue and MEH-PPV red polymers. A device structure of ITO/PEDOT:PSS/polymer/LiF/Al was employed. The white polymer device exhibited a current efficiency of 4.33 cd/A (4,816 cd/m 2 , Q.E. = 1.9 %) and a maximum luminance of 21,430 cd/m 2 at 9.2 V. The CIE coordinates were (0.35, 0.37) at 5 V and (0.29, 0.30) at 9 V.

  3. On a Minimum Problem in Smectic Elastomers

    International Nuclear Information System (INIS)

    Buonsanti, Michele; Giovine, Pasquale

    2008-01-01

    Smectic elastomers are layered materials exhibiting a solid-like elastic response along the layer normal and a rubbery one in the plane. Balance equations for smectic elastomers are derived from the general theory of continua with constrained microstructure. In this work we investigate a very simple minimum problem based on multi-well potentials where the microstructure is taken into account. The set of polymeric strains minimizing the elastic energy contains a one-parameter family of simple strain associated with a micro-variation of the degree of freedom. We develop the energy functional through two terms, the first one nematic and the second one considering the tilting phenomenon; after, by developing in the rubber elasticity framework, we minimize over the tilt rotation angle and extract the engineering stress

  4. Minimum DNBR Prediction Using Artificial Intelligence

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong Su; Kim, Ju Hyun; Na, Man Gyun [Chosun University, Gwangju (Korea, Republic of)

    2011-05-15

    The minimum DNBR (MDNBR) for prevention of the boiling crisis and the fuel clad melting is very important factor that should be consistently monitored in safety aspects. Artificial intelligence methods have been extensively and successfully applied to nonlinear function approximation such as the problem in question for predicting DNBR values. In this paper, support vector regression (SVR) model and fuzzy neural network (FNN) model are developed to predict the MDNBR using a number of measured signals from the reactor coolant system. Also, two models are trained using a training data set and verified against test data set, which does not include training data. The proposed MDNBR estimation algorithms were verified by using nuclear and thermal data acquired from many numerical simulations of the Yonggwang Nuclear Power Plant Unit 3 (YGN-3)

  5. Image Segmentation Using Minimum Spanning Tree

    Science.gov (United States)

    Dewi, M. P.; Armiati, A.; Alvini, S.

    2018-04-01

    This research aim to segmented the digital image. The process of segmentation is to separate the object from the background. So the main object can be processed for the other purposes. Along with the development of technology in digital image processing application, the segmentation process becomes increasingly necessary. The segmented image which is the result of the segmentation process should accurate due to the next process need the interpretation of the information on the image. This article discussed the application of minimum spanning tree on graph in segmentation process of digital image. This method is able to separate an object from the background and the image will change to be the binary images. In this case, the object that being the focus is set in white, while the background is black or otherwise.

  6. Statistical physics when the minimum temperature is not absolute zero

    Science.gov (United States)

    Chung, Won Sang; Hassanabadi, Hassan

    2018-04-01

    In this paper, the nonzero minimum temperature is considered based on the third law of thermodynamics and existence of the minimal momentum. From the assumption of nonzero positive minimum temperature in nature, we deform the definitions of some thermodynamical quantities and investigate nonzero minimum temperature correction to the well-known thermodynamical problems.

  7. 12 CFR 564.4 - Minimum appraisal standards.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 5 2010-01-01 2010-01-01 false Minimum appraisal standards. 564.4 Section 564.4 Banks and Banking OFFICE OF THRIFT SUPERVISION, DEPARTMENT OF THE TREASURY APPRAISALS § 564.4 Minimum appraisal standards. For federally related transactions, all appraisals shall, at a minimum: (a...

  8. 29 CFR 505.3 - Prevailing minimum compensation.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Prevailing minimum compensation. 505.3 Section 505.3 Labor... HUMANITIES § 505.3 Prevailing minimum compensation. (a)(1) In the absence of an alternative determination...)(2) of this section, the prevailing minimum compensation required to be paid under the Act to the...

  9. An Empirical Analysis of the Relationship between Minimum Wage ...

    African Journals Online (AJOL)

    An Empirical Analysis of the Relationship between Minimum Wage, Investment and Economic Growth in Ghana. ... In addition, the ratio of public investment to tax revenue must increase as minimum wage increases since such complementary changes are more likely to lead to economic growth. Keywords: minimum wage ...

  10. Minimum Covers of Fixed Cardinality in Weighted Graphs.

    Science.gov (United States)

    White, Lee J.

    Reported is the result of research on combinatorial and algorithmic techniques for information processing. A method is discussed for obtaining minimum covers of specified cardinality from a given weighted graph. By the indicated method, it is shown that the family of minimum covers of varying cardinality is related to the minimum spanning tree of…

  11. Minimum Price Guarantees In a Consumer Search Model

    NARCIS (Netherlands)

    M.C.W. Janssen (Maarten); A. Parakhonyak (Alexei)

    2009-01-01

    textabstractThis paper is the first to examine the effect of minimum price guarantees in a sequential search model. Minimum price guarantees are not advertised and only known to consumers when they come to the shop. We show that in such an environment, minimum price guarantees increase the value of

  12. Employment Effects of Minimum and Subminimum Wages. Recent Evidence.

    Science.gov (United States)

    Neumark, David

    Using a specially constructed panel data set on state minimum wage laws and labor market conditions, Neumark and Wascher (1992) presented evidence that countered the claim that minimum wages could be raised with no cost to employment. They concluded that estimates indicating that minimum wages reduced employment on the order of 1-2 percent for a…

  13. Minimum Wages and Skill Acquisition: Another Look at Schooling Effects.

    Science.gov (United States)

    Neumark, David; Wascher, William

    2003-01-01

    Examines the effects of minimum wage on schooling, seeking to reconcile some of the contradictory results in recent research using Current Population Survey data from the late 1970s through the 1980s. Findings point to negative effects of minimum wages on school enrollment, bolstering the findings of negative effects of minimum wages on enrollment…

  14. Minimum Wage Effects on Educational Enrollments in New Zealand

    Science.gov (United States)

    Pacheco, Gail A.; Cruickshank, Amy A.

    2007-01-01

    This paper empirically examines the impact of minimum wages on educational enrollments in New Zealand. A significant reform to the youth minimum wage since 2000 has resulted in some age groups undergoing a 91% rise in their real minimum wage over the last 10 years. Three panel least squares multivariate models are estimated from a national sample…

  15. 41 CFR 50-201.1101 - Minimum wages.

    Science.gov (United States)

    2010-07-01

    ... 41 Public Contracts and Property Management 1 2010-07-01 2010-07-01 true Minimum wages. 50-201... Contracts PUBLIC CONTRACTS, DEPARTMENT OF LABOR 201-GENERAL REGULATIONS § 50-201.1101 Minimum wages. Determinations of prevailing minimum wages or changes therein will be published in the Federal Register by the...

  16. 29 CFR 4.159 - General minimum wage.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 1 2010-07-01 2010-07-01 true General minimum wage. 4.159 Section 4.159 Labor Office of... General minimum wage. The Act, in section 2(b)(1), provides generally that no contractor or subcontractor... a contract less than the minimum wage specified under section 6(a)(1) of the Fair Labor Standards...

  17. 29 CFR 783.43 - Computation of seaman's minimum wage.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Computation of seaman's minimum wage. 783.43 Section 783.43...'s minimum wage. Section 6(b) requires, under paragraph (2) of the subsection, that an employee...'s minimum wage requirements by reason of the 1961 Amendments (see §§ 783.23 and 783.26). Although...

  18. 24 CFR 891.145 - Owner deposit (Minimum Capital Investment).

    Science.gov (United States)

    2010-04-01

    ... General Program Requirements § 891.145 Owner deposit (Minimum Capital Investment). As a Minimum Capital... Investment shall be one-half of one percent (0.5%) of the HUD-approved capital advance, not to exceed $25,000. ... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Owner deposit (Minimum Capital...

  19. 12 CFR 931.3 - Minimum investment in capital stock.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Minimum investment in capital stock. 931.3... CAPITAL STANDARDS FEDERAL HOME LOAN BANK CAPITAL STOCK § 931.3 Minimum investment in capital stock. (a) A Bank shall require each member to maintain a minimum investment in the capital stock of the Bank, both...

  20. 9 CFR 147.51 - Authorized laboratory minimum requirements.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Authorized laboratory minimum requirements. 147.51 Section 147.51 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE... Authorized Laboratories and Approved Tests § 147.51 Authorized laboratory minimum requirements. These minimum...

  1. Polymers of phenylenediamines

    Czech Academy of Sciences Publication Activity Database

    Stejskal, Jaroslav

    2015-01-01

    Roč. 41, February (2015), s. 1-31 ISSN 0079-6700 R&D Projects: GA ČR(CZ) GA13-00270S Institutional support: RVO:61389013 Keywords : polyphenylenediamine * phenylenediamine * conducting polymers Subject RIV: CD - Macromolecular Chemistry Impact factor: 27.184, year: 2015

  2. Nanoporous thermosetting polymers.

    Science.gov (United States)

    Raman, Vijay I; Palmese, Giuseppe R

    2005-02-15

    Potential applications of nanoporous thermosetting polymers include polyelectrolytes in fuel cells, separation membranes, adsorption media, and sensors. Design of nanoporous polymers for such applications entails controlling permeability by tailoring pore size, structure, and interface chemistry. Nanoporous thermosetting polymers are often synthesized via free radical mechanisms using solvents that phase separate during polymerization. In this work, a novel technique for the synthesis of nanoporous thermosets is presented that is based on the reactive encapsulation of an inert solvent using step-growth cross-linking polymerization without micro/macroscopic phase separation. The criteria for selecting such a monomer-polymer-solvent system are discussed based on FTIR analysis, observed micro/macroscopic phase separation, and thermodynamics of swelling. Investigation of resulting network pore structures by scanning electron microscopy (SEM) and small-angle X-ray scattering following extraction and supercritical drying using carbon dioxide showed that nanoporous polymeric materials with pore sizes ranging from 1 to 50 nm can be synthesized by varying the solvent content. The differences in the porous morphology of these materials compared to more common free radically polymerized analogues that exhibit phase separation were evident from SEM imaging. Furthermore, it was demonstrated that the chemical activity of the nanoporous materials obtained by our method could be tailored by grafting appropriate functional groups at the pore interface.

  3. Characterization of healable polymers

    Science.gov (United States)

    Nielsen, C.; Weizman, Or; Nemat-Nasser, Sia

    2010-04-01

    Materials with an internal mechanism for damage repair would be valuable in isolated environments where access is difficult or impossible. Current work is focused on characterizing neat polymers with reformable cross-linking bonds. These bonds are thermally reversible, the result of a Diels-Alder cycloaddition between furan and maleimide monomers. Candidate polymers are examined using modulated differential scanning calorimetry (DSC) to confirm the presence of reversible bonding. One polymer, 2MEP3FT, was expected to have these bonds, but none were observed. A second polymer, 2MEP4FS, with a modified furan monomer does exhibit reversible bonding. Further DSC testing and dynamic mechanical thermal analyses (DMA) are conducted to determine material properties such as glass transition temperature, storage modulus and quality of the polymerization. Healing efficiency is established using the double cleavage drilled compression (DCDC) fracture test. A column of material with a central hole is subjected to axial compression, driving cracks up and down the sample. After unloading, the cracks are healed, and the sample is retested. Comparing the results gives a quantitative evaluation of healing.

  4. Knots in polymers

    Indian Academy of Sciences (India)

    Abstract. Knots and topological entanglements play an important role in the statistical mechanics of polymers. While topological entanglement is a global property, it is possible to study the size of a knotted region both numerically and analytically. It can be shown that long-range repulsive interactions, as well as entropy ...

  5. Polyester polymer concrete overlay.

    Science.gov (United States)

    2013-01-01

    Polyester polymer concrete (PPC) was used in a trial application on a section of pavement that suffers from extensive studded tire wear. The purpose of the trial section is to determine if PPC is a possible repair strategy for this type of pavement d...

  6. Conductive polymer composition

    NARCIS (Netherlands)

    2010-01-01

    The present invention relates to a process for the preparation of a conductive polymer composition comprising graphene and the articles obtained by this process. The process comprises the following steps: A) contacting graphite oxide in an aqueous medium with a water-soluble or dispersible

  7. Porous polymer coatings on metal microneedles for enhanced drug delivery

    Science.gov (United States)

    Ullah, Asad; Kim, Chul Min; Kim, Gyu Man

    2018-04-01

    We present a simple method to coat microneedles (MNs) uniformly with a porous polymer (PLGA) that can deliver drugs at high rates. Stainless steel (SS) MNs of high mechanical strength were coated with a thin porous polymer layer to enhance their delivery rates. Additionally, to improve the interfacial adhesion between the polymer and MNs, the MN surface was modified by plasma treatment followed by dip coating with polyethyleneimine, a polymer with repeating amine units. The average failure load (the minimum force sufficient for detaching the polymer layer from the surface of SS) recorded for the modified surface coating was 25 N, whereas it was 2.2 N for the non-modified surface. Calcein dye was successfully delivered into porcine skin to a depth of 750 µm by the porous polymer-coated MNs, demonstrating that the developed MNs can pierce skin easily without deformation of MNs; additional skin penetration tests confirmed this finding. For visual comparison, rhodamine B dye was delivered using porous-coated and non-coated MNs in gelatin gel which showed that delivery with porous-coated MNs penetrate deeper when compared with non-coated MNs. Finally, lidocaine and rhodamine B dye were delivered in phosphate-buffered saline (PBS) medium by porous polymer-coated and non-coated MNs. For rhodamine B, drug delivery with the porous-coated MNs was five times higher than that with the non-coated MNs, whereas 25 times more lidocaine was delivered by the porous-coated MNs compared with the non-coated MNs.

  8. BEAM applications to polymer materials

    International Nuclear Information System (INIS)

    Tagawa, Seiichi

    1994-01-01

    Recently papers about beam applications to polymers have been increasing rapidly both in the fundamental and applied fields. Fairly large number of papers have been published in the fundamental aspects of radiation effects of beam applications to polymers such as pulse radiolysis and high density electronic excitation effects. A number of papers have been published in the more applied aspects of beam applications to polymers such as radiation processing and curing. The present paper describes recent beam applications to polymers. 1. Radiation Effects on Polymers; Radiation effects on polymers have been studied for more than 40 years. Most of work on radiation effects on polymers has been carried out by using high energy photon (gamma-ray) and electron beams, since polymers are sensitive to any kinds of ionizing radiation. Even non-ionizing radiation such as ultraviolet and visible light excites electronic excited states of polymers and then photo-chemical reactions of polymers are induced from the electronic excited states. Studies on radiation effects of other ionizing radiation on polymers have not been so popular for a long time. Recently application of new radiation such as ion beams to polymers have been worthy of remark in fields of advanced science and technology, since new radiation beams induce different radiation effects from those induced by high energy gamma-rays and electrons. 2. Beam Applications of Polymers; Recent progress in beam applications to polymers such as radiation processing and curing, x-ray and electron beam microlithography, and applications of new beams such as ion beams to polymers has been reviewed. (author)

  9. Efficient tunable luminescence of SiGe alloy sheet polymers

    International Nuclear Information System (INIS)

    Vogg, G.; Meyer, A. J.-P.; Miesner, C.; Brandt, M. S.; Stutzmann, M.

    2001-01-01

    Crystalline SiGe alloy sheet polymers were topotactically prepared from epitaxially grown calcium germanosilicide Ca(Si 1-x Ge x ) 2 precursor films in the whole composition range. These polygermanosilynes are found to be a well-defined mixture of the known siloxene and polygermyne sheet polymers with the OH groups exclusively bonded to silicon. The optical properties determined by photoluminescence and optical reflection measurements identify the mixed SiGe sheet polymers as direct semiconductors with efficient luminescence tunable in the energy range between 2.4 and 1.3 eV. [copyright] 2001 American Institute of Physics

  10. New Solid Polymer Electrolytes for Improved Lithium Batteries

    Science.gov (United States)

    Hehemann, David G.

    2002-01-01

    The objective of this work was to identify, synthesize and incorporate into a working prototype, next-generation solid polymer electrolytes, that allow our pre-existing solid-state lithium battery to function better under extreme conditions. We have synthesized polymer electrolytes in which emphasis was placed on the temperature-dependent performance of these candidate electrolytes. This project was designed to produce and integrate novel polymer electrolytes into a lightweight thin-film battery that could easily be scaled up for mass production and adapted to different applications.

  11. Advanced Functional Polymers for Increasing the Stability of Organic Photovoltaics

    DEFF Research Database (Denmark)

    Bundgaard, Eva; Helgesen, Martin; Carlé, Jon Eggert

    2013-01-01

    The development of new advanced polymers for improving the stability of OPV is reviewed. Two main degradation pathways for the OPV active layer are identified: photochemically initiated reactions primarily starting in the side chains and morphological changes that degrade the important nanostruct......The development of new advanced polymers for improving the stability of OPV is reviewed. Two main degradation pathways for the OPV active layer are identified: photochemically initiated reactions primarily starting in the side chains and morphological changes that degrade the important...... nanostructure. Chemical units can be introduced that impart an increased stability. Similarly, the morphological degradation of the optimal nanostructure can be reduced. Active polymers and blends with acceptor material are used to create nanoparticle links with controlled size. Most of these advanced polymers...

  12. gamma. -relaxation process in crystallizable polymers

    Energy Technology Data Exchange (ETDEWEB)

    Mindiyarov, Kh G; Zelenev, Yu V; Bartenev, G M [Birskij Gosudarstvennyj Pedagogicheskij Inst. (USSR)

    1975-07-01

    In the present paper, with the aid of radiothermoluminescence technique ..gamma..-relaxation processes are investigated, which are conditioned by molecular mobility and are associated with defects in the crystalline structure of polymers PEh, PP, and elastomers PIB, NK, SKD, SKI exposed to ..gamma..-rays of Co/sup 60/ at a dose rate of 1 Mrad. The shape of the thermoluminescence curve, i.e. the luminescence intensity in the ..cap alpha.. - ..gamma..-maxima, their relationship, position with respect to temperature are strongly dependent on the degree of crystallinity, on the thermal and mechanical prehistory. In highly crystalline samples of PEh and PP ..cap alpha..-maximum may be absent. Dependence has been studied of the luminescence intensity in the ..cap alpha..- and ..gamma..-maxima (Isub(..cap alpha..)/Isub(..gamma..)) on the crystallization temperature; the curve passes through the minimum when the crystallization rate is maximum. The relationship Isub(..gamma..)re of crystallinity degree.

  13. Conducting Polymers for Neutron Detection

    International Nuclear Information System (INIS)

    Clare Kimblin; Kirk Miller; Bob Vogel; Bill Quam; Harry McHugh; Glen Anthony; Steve Jones; Mike Grover

    2007-01-01

    Conjugated polymers have emerged as an attractive technology for large-area electronic applications. As organic semiconductors, they can be used to make large-area arrays of diodes or transistors using fabrication techniques developed for polymer coatings, such as spraying and screen-printing. We have demonstrated both neutron and alpha detection using diodes made from conjugated polymers and have done preliminary work to integrate a boron carbide layer into the conventional polymer device structure to capture thermal neutrons. The polymer devices appear to be insensitive to gamma rays, due to their small physical thickness and low atomic number

  14. Gel polymer electrolytes for batteries

    Science.gov (United States)

    Balsara, Nitash Pervez; Eitouni, Hany Basam; Gur, Ilan; Singh, Mohit; Hudson, William

    2014-11-18

    Nanostructured gel polymer electrolytes that have both high ionic conductivity and high mechanical strength are disclosed. The electrolytes have at least two domains--one domain contains an ionically-conductive gel polymer and the other domain contains a rigid polymer that provides structure for the electrolyte. The domains are formed by block copolymers. The first block provides a polymer matrix that may or may not be conductive on by itself, but that can soak up a liquid electrolyte, thereby making a gel. An exemplary nanostructured gel polymer electrolyte has an ionic conductivity of at least 1.times.10.sup.-4 S cm.sup.-1 at 25.degree. C.

  15. Minimum Energy Requirements in Complex Distillation Arrangements

    Energy Technology Data Exchange (ETDEWEB)

    Halvorsen, Ivar J.

    2001-07-01

    Distillation is the most widely used industrial separation technology and distillation units are responsible for a significant part of the total heat consumption in the world's process industry. In this work we focus on directly (fully thermally) coupled column arrangements for separation of multicomponent mixtures. These systems are also denoted Petlyuk arrangements, where a particular implementation is the dividing wall column. Energy savings in the range of 20-40% have been reported with ternary feed mixtures. In addition to energy savings, such integrated units have also a potential for reduced capital cost, making them extra attractive. However, the industrial use has been limited, and difficulties in design and control have been reported as the main reasons. Minimum energy results have only been available for ternary feed mixtures and sharp product splits. This motivates further research in this area, and this thesis will hopefully give some contributions to better understanding of complex column systems. In the first part we derive the general analytic solution for minimum energy consumption in directly coupled columns for a multicomponent feed and any number of products. To our knowledge, this is a new contribution in the field. The basic assumptions are constant relative volatility, constant pressure and constant molar flows and the derivation is based on Underwood's classical methods. An important conclusion is that the minimum energy consumption in a complex directly integrated multi-product arrangement is the same as for the most difficult split between any pair of the specified products when we consider the performance of a conventional two-product column. We also present the Vmin-diagram, which is a simple graphical tool for visualisation of minimum energy related to feed distribution. The Vmin-diagram provides a simple mean to assess the detailed flow requirements for all parts of a complex directly coupled arrangement. The main purpose in

  16. Minimum Energy Requirements in Complex Distillation Arrangements

    Energy Technology Data Exchange (ETDEWEB)

    Halvorsen, Ivar J

    2001-07-01

    Distillation is the most widely used industrial separation technology and distillation units are responsible for a significant part of the total heat consumption in the world's process industry. In this work we focus on directly (fully thermally) coupled column arrangements for separation of multicomponent mixtures. These systems are also denoted Petlyuk arrangements, where a particular implementation is the dividing wall column. Energy savings in the range of 20-40% have been reported with ternary feed mixtures. In addition to energy savings, such integrated units have also a potential for reduced capital cost, making them extra attractive. However, the industrial use has been limited, and difficulties in design and control have been reported as the main reasons. Minimum energy results have only been available for ternary feed mixtures and sharp product splits. This motivates further research in this area, and this thesis will hopefully give some contributions to better understanding of complex column systems. In the first part we derive the general analytic solution for minimum energy consumption in directly coupled columns for a multicomponent feed and any number of products. To our knowledge, this is a new contribution in the field. The basic assumptions are constant relative volatility, constant pressure and constant molar flows and the derivation is based on Underwood's classical methods. An important conclusion is that the minimum energy consumption in a complex directly integrated multi-product arrangement is the same as for the most difficult split between any pair of the specified products when we consider the performance of a conventional two-product column. We also present the Vmin-diagram, which is a simple graphical tool for visualisation of minimum energy related to feed distribution. The Vmin-diagram provides a simple mean to assess the detailed flow requirements for all parts of a complex directly coupled arrangement. The main purpose in the first

  17. 40 CFR 721.7260 - Polymer of poly-ethylene-polyamine and alkanediol di-gly-cidyl ether.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Polymer of poly-ethylene-polyamine and... New Uses for Specific Chemical Substances § 721.7260 Polymer of poly-ethylene-polyamine and alkanediol... chemical substance identified generically as polymer of polyethylenepolyamine and alkanediol diglycidyl...

  18. POLYMER ELECTROLYTE MEMBRANE FUEL CELLS

    DEFF Research Database (Denmark)

    2001-01-01

    A method for preparing polybenzimidazole or polybenzimidazole blend membranes and fabricating gas diffusion electrodes and membrane-electrode assemblies is provided for a high temperature polymer electrolyte membrane fuel cell. Blend polymer electrolyte membranes based on PBI and various...... thermoplastic polymers for high temperature polymer electrolyte fuel cells have also been developed. Miscible blends are used for solution casting of polymer membranes (solid electrolytes). High conductivity and enhanced mechanical strength were obtained for the blend polymer solid electrolytes....... With the thermally resistant polymer, e.g., polybenzimidazole or a mixture of polybenzimidazole and other thermoplastics as binder, the carbon-supported noble metal catalyst is tape-cast onto a hydrophobic supporting substrate. When doped with an acid mixture, electrodes are assembled with an acid doped solid...

  19. Investigating accidents involving aircraft manufactured from polymer composite materials

    OpenAIRE

    Dunn, Leigh

    2013-01-01

    This thesis looks into the examination of polymer composite wreckage from the perspective of the aircraft accident investigator. It develops an understanding of the process of wreckage examination as well as identifying the potential for visual and macroscopic interpretation of polymer composite aircraft wreckage. The in-field examination of aircraft wreckage, and subsequent interpretations of material failures, can be a significant part of an aircraft accident investigation. ...

  20. Minimum relative entropy, Bayes and Kapur

    Science.gov (United States)

    Woodbury, Allan D.

    2011-04-01

    The focus of this paper is to illustrate important philosophies on inversion and the similarly and differences between Bayesian and minimum relative entropy (MRE) methods. The development of each approach is illustrated through the general-discrete linear inverse. MRE differs from both Bayes and classical statistical methods in that knowledge of moments are used as ‘data’ rather than sample values. MRE like Bayes, presumes knowledge of a prior probability distribution and produces the posterior pdf itself. MRE attempts to produce this pdf based on the information provided by new moments. It will use moments of the prior distribution only if new data on these moments is not available. It is important to note that MRE makes a strong statement that the imposed constraints are exact and complete. In this way, MRE is maximally uncommitted with respect to unknown information. In general, since input data are known only to within a certain accuracy, it is important that any inversion method should allow for errors in the measured data. The MRE approach can accommodate such uncertainty and in new work described here, previous results are modified to include a Gaussian prior. A variety of MRE solutions are reproduced under a number of assumed moments and these include second-order central moments. Various solutions of Jacobs & van der Geest were repeated and clarified. Menke's weighted minimum length solution was shown to have a basis in information theory, and the classic least-squares estimate is shown as a solution to MRE under the conditions of more data than unknowns and where we utilize the observed data and their associated noise. An example inverse problem involving a gravity survey over a layered and faulted zone is shown. In all cases the inverse results match quite closely the actual density profile, at least in the upper portions of the profile. The similar results to Bayes presented in are a reflection of the fact that the MRE posterior pdf, and its mean

  1. Accelerated Testing Of Photothermal Degradation Of Polymers

    Science.gov (United States)

    Kim, Soon Sam; Liang, Ranty Hing; Tsay, Fun-Dow

    1989-01-01

    Electron-spin-resonance (ESR) spectroscopy and Arrhenius plots used to determine maximum safe temperature for accelerated testing of photothermal degradation of polymers. Aging accelerated by increasing illumination, temperature, or both. Results of aging tests at temperatures higher than those encountered in normal use valid as long as mechanism of degradation same throughout range of temperatures. Transition between different mechanisms at some temperature identified via transition between activation energies, manifesting itself as change in slope of Arrhenius plot at that temperature.

  2. Adsorption and flocculation by polymers and polymer mixtures.

    Science.gov (United States)

    Gregory, John; Barany, Sandor

    2011-11-14

    Polymers of various types are in widespread use as flocculants in several industries. In most cases, polymer adsorption is an essential prerequisite for flocculation and kinetic aspects are very important. The rates of polymer adsorption and of re-conformation (relaxation) of adsorbed chains are key factors that influence the performance of flocculants and their mode of action. Polyelectrolytes often tend to adopt a rather flat adsorbed configuration and in this state their action is mainly through charge effects, including 'electrostatic patch' attraction. When the relaxation rate is quite low, particle collisions may occur while the adsorbed chains are still in an extended state and flocculation by polymer bridging may occur. These effects are now well understood and supported by much experimental evidence. In recent years there has been considerable interest in the use of multi-component flocculants, especially dual-polymer systems. In the latter case, there can be significant advantages over the use of single polymers. Despite some complications, there is a broad understanding of the action of dual polymer systems. In many cases the sequence of addition of the polymers is important and the pre-adsorbed polymer can have two important effects: providing adsorption sites for the second polymer or causing a more extended adsorbed conformation as a result of 'site blocking'. Copyright © 2011 Elsevier B.V. All rights reserved.

  3. Structure and Dynamics of Polymer/Polymer grafted nanoparticle composite

    Science.gov (United States)

    Archer, Lynden

    Addition of nanoparticles to polymers is a well-practiced methodology for augmenting various properties of the polymer host, including mechanical strength, thermal stability, barrier properties, dimensional stability and wear resistance. Many of these property changes are known to arise from nanoparticle-induced modification of polymer structure and chain dynamics, which are strong functions of the dispersion state of the nanoparticles' and on their relative size (D) to polymer chain dimensions (e.g. Random coil radius Rg or entanglement mesh size a) . This talk will discuss polymer nanocomposites (PNCs) comprised of Polyethylene Glycol (PEG) tethered silica nanoparticles (SiO2-PEG) dispersed in polymers as model systems for investigating phase stability and dynamics of PNCs. On the basis of small-angle X-ray Scattering, it will be shown that favorable enthalpic interactions between particle-tethered chains and a polymer host provides an important mechanism for creating PNCs in which particle aggregation is avoided. The talk will report on polymer and particle scale dynamics in these materials and will show that grafted nanoparticles well dispersed in a polymer host strongly influence the host polymer relaxation dynamics on all timescales and the polymers in turn produce dramatic changes in the nature (from diffusive to hyperdiffusive) and speed of nano particle decorrelation dynamics at the polymer entanglement threshold. A local viscosity model capable of explaining these observations is discussed and the results compared with scaling theories for NP motions in polymers This material is based on work supported by the National Science Foundation Award Nos. DMR-1609125 and CBET-1512297.

  4. Boiling characteristics of dilute polymer solutions and implications for the suppression of vapor explosions

    Energy Technology Data Exchange (ETDEWEB)

    Bang, K.H.; Kim, M.H. [Univ. of Science and Technology, Pohang (Korea, Republic of)

    1995-09-01

    Quenching experiments of hot solid spheres in dilute aqueous solutions of polyethylene oxide polymer have been conducted for the purpose of investigating the physical mechanisms of the suppression of vapor explosions in this polymer solutions. Two spheres of 22.2mm and 9.5mm-diameter were tested in the polymer solutions of various concentrations at 30{degrees}C. Minimum film boiling temperature ({Delta}T{sub MFB}) in this highly-subcooled liquid rapidly decreased from over 700{degrees}c for pure water to about 150{degrees}C as the polymer concentration was increased up to 300ppm for 22.2mm sphere, and it decreased to 350{degrees}C for 9.5mm sphere. This rapid reduction of minimum film boiling temperature in the PEO aqueous solutions can explain its ability of the suppression of spontaneous vapor explosions. The ability of suppression of vapor explosions by dilute polyethylene oxide solutions against an external trigger pressure was tested by dropping molten tin into the polymer solutions at 25{degrees}C. It was observed that in 50ppm solutions more mass fragmented than in pure water, but produced weaker explosion pressures. The explosion was completely suppressed in 300ppm solutions with the external trigger. The debris size distributions of fine fragments smaller than 0.7mm were shown almost identical regardless of the polymer concentrations.

  5. Sedimentation across the central California oxygen minimum zone: an alternative coastal upwelling sequence.

    Science.gov (United States)

    Vercoutere, T.L.; Mullins, H.T.; McDougall, K.; Thompson, J.B.

    1987-01-01

    Distribution, abundance, and diversity of terrigenous, authigenous, and biogenous material provide evidence of the effect of bottom currents and oxygen minimum zone (OMZ) on continental slope sedimentation offshore central California. Three major OMZ facies are identified, along the upper and lower edges of OMZ and one at its core.-from Authors

  6. Minimum Bias Measurements at the LHC

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00022031; The ATLAS collaboration

    2016-01-01

    Inclusive charged particle measurements at hadron colliders probe the low-energy nonperturbative region of QCD. Pseudorapidity distributions of charged-particles produced in pp collisions at 13 TeV have been measured by the CMS experiment. The ATLAS collaboration has measured the inclusive charged particle multiplicity and its dependence on transverse momentum and pseudorapidity in special data sets with low LHC beam current, recorded at a center-of-mass energy of 13 TeV. The measurements present the first detailed studies in inclusive phase spaces with a minimum transverse momentum of 100 MeV and 500 MeV. The distribution of electromagnetic and hadronic energy in the very forward phase-space has been measured with the CASTOR calorimeters located at a pseudorapidity of -5.2 to -6.6 in the very forward region of CMS. The energy distributions are very powerful benchmarks to study the performance of MPI in hadronic interactions models at 13 TeV collision energy. All measurements are compared with predictions of ...

  7. Topside measurements at Jicamarca during solar minimum

    Directory of Open Access Journals (Sweden)

    D. L. Hysell

    2009-01-01

    Full Text Available Long-pulse topside radar data acquired at Jicamarca and processed using full-profile analysis are compared to data processed using more conventional, range-gated approaches and with analytic and computational models. The salient features of the topside observations include a dramatic increase in the Te/Ti temperature ratio above the F peak at dawn and a local minimum in the topside plasma temperature in the afternoon. The hydrogen ion fraction was found to exhibit hyperbolic tangent-shaped profiles that become shallow (gradually changing above the O+-H+ transition height during the day. The profile shapes are generally consistent with diffusive equilibrium, although shallowing to the point of changes in inflection can only be accounted for by taking the effects of E×B drifts and meridional winds into account. The SAMI2 model demonstrates this as well as the substantial effect that drifts and winds can have on topside temperatures. Significant quiet-time variability in the topside composition and temperatures may be due to variability in the mechanical forcing. Correlations between topside measurements and magnetometer data at Jicamarca support this hypothesis.

  8. Topside measurements at Jicamarca during solar minimum

    Directory of Open Access Journals (Sweden)

    D. L. Hysell

    2009-01-01

    Full Text Available Long-pulse topside radar data acquired at Jicamarca and processed using full-profile analysis are compared to data processed using more conventional, range-gated approaches and with analytic and computational models. The salient features of the topside observations include a dramatic increase in the Te/Ti temperature ratio above the F peak at dawn and a local minimum in the topside plasma temperature in the afternoon. The hydrogen ion fraction was found to exhibit hyperbolic tangent-shaped profiles that become shallow (gradually changing above the O+-H+ transition height during the day. The profile shapes are generally consistent with diffusive equilibrium, although shallowing to the point of changes in inflection can only be accounted for by taking the effects of E×B drifts and meridional winds into account. The SAMI2 model demonstrates this as well as the substantial effect that drifts and winds can have on topside temperatures. Significant quiet-time variability in the topside composition and temperatures may be due to variability in the mechanical forcing. Correlations between topside measurements and magnetometer data at Jicamarca support this hypothesis.

  9. Designing from minimum to optimum functionality

    Science.gov (United States)

    Bannova, Olga; Bell, Larry

    2011-04-01

    This paper discusses a multifaceted strategy to link NASA Minimal Functionality Habitable Element (MFHE) requirements to a compatible growth plan; leading forward to evolutionary, deployable habitats including outpost development stages. The discussion begins by reviewing fundamental geometric features inherent in small scale, vertical and horizontal, pressurized module configuration options to characterize applicability to meet stringent MFHE constraints. A proposed scenario to incorporate a vertical core MFHE concept into an expanded architecture to provide continuity of structural form and a logical path from "minimum" to "optimum" design of a habitable module. The paper describes how habitation and logistics accommodations could be pre-integrated into a common Hab/Log Module that serves both habitation and logistics functions. This is offered as a means to reduce unnecessary redundant development costs and to avoid EVA-intensive on-site adaptation and retrofitting requirements for augmented crew capacity. An evolutionary version of the hard shell Hab/Log design would have an expandable middle section to afford larger living and working accommodations. In conclusion, the paper illustrates that a number of cargo missions referenced for NASA's 4.0.0 Lunar Campaign Scenario could be eliminated altogether to expedite progress and reduce budgets. The plan concludes with a vertical growth geometry that provides versatile and efficient site development opportunities using a combination of hard Hab/Log modules and a hybrid expandable "CLAM" (Crew Lunar Accommodations Module) element.

  10. Minimum nonuniform graph partitioning with unrelated weights

    Science.gov (United States)

    Makarychev, K. S.; Makarychev, Yu S.

    2017-12-01

    We give a bi-criteria approximation algorithm for the Minimum Nonuniform Graph Partitioning problem, recently introduced by Krauthgamer, Naor, Schwartz and Talwar. In this problem, we are given a graph G=(V,E) and k numbers ρ_1,\\dots, ρ_k. The goal is to partition V into k disjoint sets (bins) P_1,\\dots, P_k satisfying \\vert P_i\\vert≤ ρi \\vert V\\vert for all i, so as to minimize the number of edges cut by the partition. Our bi-criteria algorithm gives an O(\\sqrt{log \\vert V\\vert log k}) approximation for the objective function in general graphs and an O(1) approximation in graphs excluding a fixed minor. The approximate solution satisfies the relaxed capacity constraints \\vert P_i\\vert ≤ (5+ \\varepsilon)ρi \\vert V\\vert. This algorithm is an improvement upon the O(log \\vert V\\vert)-approximation algorithm by Krauthgamer, Naor, Schwartz and Talwar. We extend our results to the case of 'unrelated weights' and to the case of 'unrelated d-dimensional weights'. A preliminary version of this work was presented at the 41st International Colloquium on Automata, Languages and Programming (ICALP 2014). Bibliography: 7 titles.

  11. Isoflurane minimum alveolar concentration reduction by fentanyl.

    Science.gov (United States)

    McEwan, A I; Smith, C; Dyar, O; Goodman, D; Smith, L R; Glass, P S

    1993-05-01

    Isoflurane is commonly combined with fentanyl during anesthesia. Because of hysteresis between plasma and effect site, bolus administration of fentanyl does not accurately describe the interaction between these drugs. The purpose of this study was to determine the MAC reduction of isoflurane by fentanyl when both drugs had reached steady biophase concentrations. Seventy-seven patients were randomly allocated to receive either no fentanyl or fentanyl at several predetermined plasma concentrations. Fentanyl was administered using a computer-assisted continuous infusion device. Patients were also randomly allocated to receive a predetermined steady state end-tidal concentration of isoflurane. Blood samples for fentanyl concentration were taken at 10 min after initiation of the infusion and before and immediately after skin incision. A minimum of 20 min was allowed between the start of the fentanyl infusion and skin incision. The reduction in the MAC of isoflurane by the measured fentanyl concentration was calculated using a maximum likelihood solution to a logistic regression model. There was an initial steep reduction in the MAC of isoflurane by fentanyl, with 3 ng/ml resulting in a 63% MAC reduction. A ceiling effect was observed with 10 ng/ml providing only a further 19% reduction in MAC. A 50% decrease in MAC was produced by a fentanyl concentration of 1.67 ng/ml. Defining the MAC reduction of isoflurane by all the opioids allows their more rational administration with inhalational anesthetics and provides a comparison of their relative anesthetic potencies.

  12. A preliminary assessment of the effects of radiation on polymer properties

    International Nuclear Information System (INIS)

    Dickson, L.W.

    1988-01-01

    The literature on the effects of radiation on the properties of various polymers and composites has been briefly reviewed for the purpose of identifying polymeric materials that could be irradiated to improve their performance. Radiation treatment of polymers may lead to cross-linking or chain scission reactions, depending on the chemical nature of the polymer. Cross-linking generally leads to an improvement in the mechanical properties of the polymer. Chain scission leads to deterioration in mechanical properties. The properties of irradiated polymers also depend on the degree of polymer crystallinity and the irradiation conditions, including dose rate and the presence of oxygen, cross-linking agents and other additives. A 30% increase in the tensile strength of many polymers may be obtained by radiation cross-linking under appropriate conditions. 40 refs

  13. Computer-aided polymer design using group contribution plus property models

    DEFF Research Database (Denmark)

    Satyanarayana, Kavitha Chelakara; Abildskov, Jens; Gani, Rafiqul

    2009-01-01

    . Polymer repeat unit property prediction models are required to calculate the properties of the generated repeat units. A systematic framework incorporating recently developed group contribution plus (GC(+)) models and an extended CAMD technique to include design of polymer repeat units is highlighted...... in this paper. The advantage of a GC(+) model in CAMD applications is that a very large number of polymer structures can be considered even though some of the group parameters may not be available. A number of case studies involving different polymer design problems have been solved through the developed......The preliminary step for polymer product design is to identify the basic repeat unit structure of the polymer that matches the target properties. Computer-aided molecular design (CAMD) approaches can be applied for generating the polymer repeat unit structures that match the required constraints...

  14. A Phosphate Minimum in the Oxygen Minimum Zone (OMZ) off Peru

    Science.gov (United States)

    Paulmier, A.; Giraud, M.; Sudre, J.; Jonca, J.; Leon, V.; Moron, O.; Dewitte, B.; Lavik, G.; Grasse, P.; Frank, M.; Stramma, L.; Garcon, V.

    2016-02-01

    The Oxygen Minimum Zone (OMZ) off Peru is known to be associated with the advection of Equatorial SubSurface Waters (ESSW), rich in nutrients and poor in oxygen, through the Peru-Chile UnderCurrent (PCUC), but this circulation remains to be refined within the OMZ. During the Pelágico cruise in November-December 2010, measurements of phosphate revealed the presence of a phosphate minimum (Pmin) in various hydrographic stations, which could not be explained so far and could be associated with a specific water mass. This Pmin, localized at a relatively constant layer ( 20minimum with a mean vertical phosphate decrease of 0.6 µM but highly variable between 0.1 and 2.2 µM. In average, these Pmin are associated with a predominant mixing of SubTropical Under- and Surface Waters (STUW and STSW: 20 and 40%, respectively) within ESSW ( 25%), complemented evenly by overlying (ESW, TSW: 8%) and underlying waters (AAIW, SPDW: 7%). The hypotheses and mechanisms leading to the Pmin formation in the OMZ are further explored and discussed, considering the physical regional contribution associated with various circulation pathways ventilating the OMZ and the local biogeochemical contribution including the potential diazotrophic activity.

  15. How do polymers degrade?

    Science.gov (United States)

    Lyu, Suping

    2011-03-01

    Materials derived from agricultural products such as cellulose, starch, polylactide, etc. are more sustainable and environmentally benign than those derived from petroleum. However, applications of these polymers are limited by their processing properties, chemical and thermal stabilities. For example, polyethylene terephthalate fabrics last for many years under normal use conditions, but polylactide fabrics cannot due to chemical degradation. There are two primary mechanisms through which these polymers degrade: via hydrolysis and via oxidation. Both of these two mechanisms are related to combined factors such as monomer chemistry, chain configuration, chain mobility, crystallinity, and permeation to water and oxygen, and product geometry. In this talk, we will discuss how these materials degrade and how the degradation depends on these factors under application conditions. Both experimental studies and mathematical modeling will be presented.

  16. Dielectric Actuation of Polymers

    Science.gov (United States)

    Niu, Xiaofan

    Dielectric polymers are widely used in a plurality of applications, such as electrical insulation, dielectric capacitors, and electromechanical actuators. Dielectric polymers with large strain deformations under an electric field are named dielectric elastomers (DE), because of their relative low modulus, high elongation at break, and outstanding resilience. Dielectric elastomer actuators (DEA) are superior to traditional transducers as a muscle-like technology: large strains, high energy densities, high coupling efficiency, quiet operation, and light weight. One focus of this dissertation is on the design of DE materials with high performance and easy processing. UV radiation curing of reactive species is studied as a generic synthesis methodology to provide a platform for material scientists to customize their own DE materials. Oligomers/monomers, crosslinkers, and other additives are mixed and cured at appropriate ratios to control the stress-strain response, suppress electromechanical instability of the resulting polymers, and provide stable actuation strains larger than 100% and energy densities higher than 1 J/g. The processing is largely simplified in the new material system by removal of the prestretching step. Multilayer stack actuators with 11% linear strain are demonstrated in a procedure fully compatible with industrial production. A multifunctional DE derivative material, bistable electroactive polymer (BSEP), is invented enabling repeatable rigid-to-rigid deformation without bulky external structures. Bistable actuation allows the polymer actuator to have two distinct states that can support external load without device failure. Plasticizers are used to lower the glass transition temperature to 45 °C. Interpenetrating polymer network structure is established inside the BSEP to suppress electromechanical instability, providing a breakdown field of 194 MV/m and a stable bistable strain as large as 228% with a 97% strain fixity. The application of BSEP

  17. Polymer Physics Prize Talk

    Science.gov (United States)

    Olvera de La Cruz, Monica

    Polymer electrolytes have been particularly difficult to describe theoretically given the large number of disparate length scales involved in determining their physical properties. The Debye length, the Bjerrum length, the ion size, the chain length, and the distance between the charges along their backbones determine their structure and their response to external fields. We have developed an approach that uses multi-scale calculations with the capability of demonstrating the phase behavior of polymer electrolytes and of providing a conceptual understanding of how charge dictates nano-scale structure formation. Moreover, our molecular dynamics simulations have provided an understanding of the coupling of their conformation to their dynamics, which is crucial to design self-assembling materials, as well as to explore the dynamics of complex electrolytes for energy storage and conversion applications.

  18. White Polymer Light-Emitting Diodes Based on Exciplex Electroluminescence from Polymer Blends and a Single Polymer.

    Science.gov (United States)

    Liang, Junfei; Zhao, Sen; Jiang, Xiao-Fang; Guo, Ting; Yip, Hin-Lap; Ying, Lei; Huang, Fei; Yang, Wei; Cao, Yong

    2016-03-09

    In this Article, we designed and synthesized a series of polyfluorene derivatives, which consist of the electron-rich 4,4'-(9-alkyl-carbazole-3,6-diyl)bis(N,N-diphenylaniline) (TPA-Cz) in the side chain and the electron-deficient dibenzothiophene-5,5-dioxide (SO) unit in the main chain. The resulting copolymer PF-T25 that did not comprise the SO unit exhibited blue light-emission with the Commission Internationale de L'Eclairage coordinates of (0.16, 0.10). However, by physically blending PF-T25 with a blue light-emitting SO-based oligomer, a novel low-energy emission correlated to exciplex emerged due to the appropriate energy level alignment of TPA-Cz and the SO-based oligomers, which showed extended exciton lifetime as confirmed by time-resolved photoluminescent spectroscopy. The low-energy emission was also identified in copolymers consisting of SO unit in the main chain, which can effectively compensate for the high-energy emission to produce binary white light-emission. Polymer light-emitting diodes based on the exciplex-type single greenish-white polymer exhibit the peak luminous efficiency of 2.34 cd A(-1) and the maximum brightness of 12 410 cd m(-2), with Commission Internationale de L'Eclairage color coordinates (0.27, 0.39). The device based on such polymer showed much better electroluminescent stability than those based on blending films. These observations indicated that developing a single polymer with the generated exciplex emission can be a novel and effective molecular design strategy toward highly stable and efficient white polymer light-emitting diodes.

  19. Conjugated polymer nanoparticles, methods of using, and methods of making

    KAUST Repository

    Habuchi, Satoshi

    2017-03-16

    Embodiments of the present disclosure provide for conjugated polymer nanoparticle, method of making conjugated polymer nanoparticles, method of using conjugated polymer nanoparticle, polymers, and the like.

  20. Conjugated polymer nanoparticles, methods of using, and methods of making

    KAUST Repository

    Habuchi, Satoshi; Piwonski, Hubert Marek; Michinobu, Tsuyoshi

    2017-01-01

    Embodiments of the present disclosure provide for conjugated polymer nanoparticle, method of making conjugated polymer nanoparticles, method of using conjugated polymer nanoparticle, polymers, and the like.

  1. Solid polymer electrolytes

    Science.gov (United States)

    Abraham, Kuzhikalail M.; Alamgir, Mohamed; Choe, Hyoun S.

    1995-01-01

    This invention relates to Li ion (Li.sup.+) conductive solid polymer electrolytes composed of poly(vinyl sulfone) and lithium salts, and their use in all-solid-state rechargeable lithium ion batteries. The lithium salts comprise low lattice energy lithium salts such as LiN(CF.sub.3 SO.sub.2).sub.2, LiAsF.sub.6, and LiClO.sub.4.

  2. CLASSIFICATION OF BIODEGRADABLE POLYMERS

    Directory of Open Access Journals (Sweden)

    I. I. Karpunin

    2015-01-01

    Full Text Available The executed investigations have made it possible to ascertain that a morphological structure of starch granules mainly determine technological peculiarities of starch isolation from raw material, its modification and its later use. Morphological structure of starch granules primarily depends on type of plant starch-containing raw material which has been used for its isolation. Class of raw material exerts a strong impact on the shape and size of the granules. Linear “light” amylose chains and “heavy” amylopectin branch chains form a starch granule ultrastructure. X-ray research has proved that starch granules are characterized by presence of interlacing amorphous and crystalline regions. In this case polymer orientation using stretching of the obtained end product influences on its physical and mechanical  indices which are increasing due to polymer orientation. For the purpose of packaging orientation of polymer films can solve such important problems as significant improvement of operational properties, creation of  thermosetting film materials, improvement of qualitative indices of the recycled film.Results of the conducted research have proved the fact that it is necessary to make changes in technology in order to increase biological degradability of the recycled packaging made from polymers and improve physical and mechanical indices. In this regard film production technology presupposes usage of such substances as stark and others which are characterized by rather large presence of branch chains of molecules and interlacing amorphous and crystalline regions. Such approach makes it possible to obtain after-use package which is strong and quickly degradable by micro-organisms.

  3. Dynamics of polymers

    Energy Technology Data Exchange (ETDEWEB)

    Buchenau, U [Forschungszentrum Juelich GmbH (Germany). Inst. fuer Energieverfahrenstechnik

    1996-11-01

    Neutron scattering from amorphous polymers allows to switch from incoherent to coherent scattering in the same substance. The power of the tool for the study of the picosecond dynamics of disordered matter is illustrated for polybutadiene, polycarbonate and polystyrene. The results suggest a mixture of sound waves and localized modes, strongly interacting with each other, in the picosecond range. (author) 8 figs., tabs., 39 refs.

  4. Conjugated Polymer Solar Cells

    Science.gov (United States)

    2006-05-01

    thermal gravimetry analysis (TGA)............... 12 2.6 Photoluminescence (PL) spectroscopy... gravimetry analysis (TGA) Thermal analysis of polymer films has been accomplished by TGA and DSC methods with the aid of Perkin-Elmer Series 7 Analysers...The MEH-PPV/acceptor films were prepared by spin-casting of the resulting mixture (with or without precipitate ) on glass substrates of diameter 23 mm

  5. Absorbable and biodegradable polymers

    CERN Document Server

    Shalaby, Shalaby W

    2003-01-01

    INTRODUCTION NOTES: Absorbable/Biodegradable Polymers: Technology Evolution. DEVELOPMENT AND APPLICATIONOF NEW SYSTEMS: Segmented Copolyesters with Prolonged Strength Retention Profiles. Polyaxial Crystalline Fiber-Forming Copolyester. Polyethylene Glycol-Based Copolyesters. Cyanoacrylate-Based Systems as Tissue Adhesives. Chitosan-Based Systems. Hyaluronic Acid-Based Systems. DEVELOPMENTS IN PREPARATIVE, PROCESSING, AND EVALUATION METHODS: New Approaches to the Synthesis of Crystalline. Fiber-Forming Aliphatic Copolyesters. Advances in Morphological Development to Tailor the Performance of Me

  6. Luminescent lanthanide coordination polymers

    Energy Technology Data Exchange (ETDEWEB)

    Ma, L.; Evans, O.R.; Foxman, B.M.; Lin, W.

    1999-12-13

    One-dimensional lanthanide coordination polymers with the formula Ln(isonicotinate){sub 3}(H{sub 2}O){sub 2} (Ln = Ce, Pr, Nd, Sm, Eu, Tb; 1a-f) were synthesized by treating nitrate or perchlorate salts of Ln(III) with 4-pyridinecarboxaldehyde under hydro(solvo)thermal conditions. Single-crystal and powder X-ray diffraction studies indicate that these lanthanide coordination polymers adopt two different structures. While Ce(III), Pr(III), and Nd(III) complexes adopt a chain structure with alternating Ln-(carboxylate){sub 2}-Ln and Ln-(carboxylate){sub 4}-Ln linkages, Sm(III), Eu(III), and Tb(III) complexes have a doubly carboxylate-bridged infinite-chain structure with one chelating carboxylate group on each metal center. In both structures, the lanthanide centers also bind to two water molecules to yield an eight-coordinate, square antiprismatic geometry. The pyridine nitrogen atoms of the isonicotinate groups do not coordinate to the metal centers in these lanthanide(III) complexes; instead, they direct the formation of Ln(III) coordination polymers via hydrogen bonding with coordinated water molecules. Photoluminescence measurements show that Tb(isonicotinate){sub 3}(H{sub 2}O){sub 2} is highly emissive at room temperature with a quantum yield of {approximately}90%. These results indicate that highly luminescent lanthanide coordination polymers can be assembled using a combination of coordination and hydrogen bonds. Crystal data for 1a: monoclinic space group P2{sub 1}/c, a = 9.712(2) {angstrom}, b = 19.833(4) {angstrom}, c = 11.616(2) {angstrom}, {beta} = 111.89(3){degree}, Z = 4. Crystal data for 1f: monoclinic space group C2/c, a = 20.253(4) {angstrom}, b = 11.584(2) {angstrom}, c = 9.839(2) {angstrom}, {beta} = 115.64(3){degree}, Z = 8.

  7. Mechanoresponsive Healing Polymers

    Science.gov (United States)

    Gordon, Keith L. (Inventor); Siochi, Emilie J. (Inventor)

    2018-01-01

    Methods are provided to produce new mechanoresponsive healing systems. Additionally, various embodiments provide a two tier self-healing material system concept that provides a non-intrusive method to mitigate impact damage in a structure ranging from low velocity impact damage (e.g., crack damage) to high velocity impact damage (e.g., ballistic damage.) The various embodiments provide the mechanophore linked polymer PBG-BCB-PBG. The various embodiments provide methods for synthesizing PBG-BCB-PBG.

  8. Electrochemical polymer electrolyte membranes

    CERN Document Server

    Fang, Jianhua; Wilkinson, David P

    2015-01-01

    Electrochemical Polymer Electrolyte Membranes covers PEMs from fundamentals to applications, describing their structure, properties, characterization, synthesis, and use in electrochemical energy storage and solar energy conversion technologies. Featuring chapters authored by leading experts from academia and industry, this authoritative text: Discusses cutting-edge methodologies in PEM material selection and fabricationPoints out important challenges in developing PEMs and recommends mitigation strategies to improve PEM performanceAnalyzes the cur

  9. BioArtificial polymers

    Science.gov (United States)

    Szałata, Kamila; Gumi, Tania

    2017-07-01

    Nowadays, the polymer science has impact in practically all life areas. Countless benefits coming from the usage of materials with high mechanical and chemical resistance, variety of functionalities and potentiality of modification drive to the development of new application fields. Novel approaches of combining these synthetic substances with biomolecules lead to obtain multifunctional hybrid conjugates which merge the bioactivity of natural component with outstanding properties of artificial polymer. Over the decades, an immense progress in bioartificial composites domain allowed to reach a high level of knowledge in terms of natural-like systems engineering, leading to diverse strategies of biomolecule immobilization. Together with different available options, including covalent and noncovalent attachment, come various challenges, related mainly with maintaining the biological activity of fixed molecules. Even though the amount of applications that achieve commercial status is still not substantial, and is expanding continuously in the disciplines like "smart materials," biosensors, delivery systems, nanoreactors and many others. A huge number of remarkable developments reported in the literature present a potential of bioartificial conjugates as a fabrics with highly controllable structure and multiple functionalities, serving as a powerful nanotechnological tool. This novel approach brings closer biologists, chemists and engineers, who sharing their effort and complementing the knowledge can revolutionize the field of bioartificial polymer science.

  10. Business, market and intellectual property analysis of polymer solar cells

    International Nuclear Information System (INIS)

    Nielsen, Torben D.; Krebs, Frederik C.; Cruickshank, Craig; Foged, Soeren; Thorsen, Jesper

    2010-01-01

    The business potential of polymer solar cells is reviewed and the market opportunities analyzed on the basis of the currently reported and projected performance and manufacturing cost of polymer solar cells. Possible new market areas are identified and described. An overview of the present patent and intellectual property situation is also given and a patent map of polymer solar cells is drawn in a European context. It is found that the business potential of polymer solar cells is large when taking the projections for future performance into account while the currently available performance and manufacturing cost leaves little room for competition on the thin film photovoltaic market. However, polymer solar cells do enable the competitive manufacture of low cost niche products and is viewed as financially viable in its currently available form in a large volume approximation. Finally, it is found that the polymer solar cell technology is very poorly protected in Europe with the central patents being valid in only France, Germany, the Netherlands and the United Kingdom. Several countries with a large potential for PV such as Portugal and Greece are completely open and have apparently no relevant patents. This is viewed as a great advantage for the possible commercialization of polymer solar cells in a European setting as the competition for the market will be based on the manufacturing performance rather than domination by a few patent stakeholders. (author)

  11. RCoronae Borealis at the 2003 light minimum

    Science.gov (United States)

    Kameswara Rao, N.; Lambert, David L.; Shetrone, Matthew D.

    2006-08-01

    A set of five high-resolution optical spectra of R CrB obtained in 2003 March is discussed. At the time of the first spectrum (March 8), the star was at V = 12.6, a decline of more than six magnitudes. By March 31, the date of the last observation, the star at V = 9.3 was on the recovery to maximum light (V = 6). The 2003 spectra are compared with the extensive collection of spectra from the 1995-1996 minimum presented previously. Spectroscopic features common to the two minima include the familiar ones also seen in spectra of other R Coronae Borealis stars (RCBs) in decline: sharp emission lines of neutral and singly ionized atoms, broad emission lines including HeI, [NII] 6583 Å, Na D and CaII H & K lines, and blueshifted absorption lines of Na D, and KI resonance lines. Prominent differences between the 2003 and 1995-1996 spectra are seen. The broad Na D and Ca H & K lines in 2003 and 1995-1996 are centred approximately on the mean stellar velocity. The 2003 profiles are fit by a single Gaussian, but in 1995-1996 two Gaussians separated by about 200 km s-1 were required. However, the HeI broad emission lines are fit by a single Gaussian at all times; the emitting He and Na-Ca atoms are probably not colocated. The C2 Phillips 2-0 lines were detected as sharp absorption lines and the C2 Swan band lines as sharp emission lines in 2003, but in 1995-1996 the Swan band emission lines were broad and the Phillips lines were undetected. The 2003 spectra show CI sharp emission lines at minimum light with a velocity changing in 5 d by about 20 km s-1 when the velocity of `metal' sharp lines is unchanged; the CI emission may arise from shock-heated gas. Reexamination of spectra obtained at maximum light in 1995 shows extended blue wings to strong lines with the extension dependent on a line's lower excitation potential; this is the signature of a stellar wind, also revealed by published observations of the HeI 10830 Å line at maximum light. Changes in the cores of the

  12. A 34 ampere-hour nickel-cadmium minimum trickle charge testing

    Science.gov (United States)

    Timmerman, P. J.

    1985-01-01

    The current rates used for trickle charging batteries are critical in maintaining a full charge and in preventing an overcharge condition. The importance of the trickle charge rate comes from the design, maintenance and operational requirements of an electrical power system. The results of minimum trickle charge testing performed on six 34 ampere-hour, nickel-cadmium cells manufactured by General Electric are described. The purpose of the testing was to identify the minimum trickle charge rates at temperatures of 15 C and 30 C.

  13. Polymer crowding and shape distributions in polymer-nanoparticle mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Wei Kang; Denton, Alan R., E-mail: alan.denton@ndsu.edu [Department of Physics, North Dakota State University, Fargo, North Dakota 58108-6050 (United States)

    2014-09-21

    Macromolecular crowding can influence polymer shapes, which is important for understanding the thermodynamic stability of polymer solutions and the structure and function of biopolymers (proteins, RNA, DNA) under confinement. We explore the influence of nanoparticle crowding on polymer shapes via Monte Carlo simulations and free-volume theory of a coarse-grained model of polymer-nanoparticle mixtures. Exploiting the geometry of random walks, we model polymer coils as effective penetrable ellipsoids, whose shapes fluctuate according to the probability distributions of the eigenvalues of the gyration tensor. Accounting for the entropic cost of a nanoparticle penetrating a larger polymer coil, we compute the crowding-induced shift in the shape distributions, radius of gyration, and asphericity of ideal polymers in a theta solvent. With increased nanoparticle crowding, we find that polymers become more compact (smaller, more spherical), in agreement with predictions of free-volume theory. Our approach can be easily extended to nonideal polymers in good solvents and used to model conformations of biopolymers in crowded environments.

  14. Polymer crowding and shape distributions in polymer-nanoparticle mixtures

    International Nuclear Information System (INIS)

    Lim, Wei Kang; Denton, Alan R.

    2014-01-01

    Macromolecular crowding can influence polymer shapes, which is important for understanding the thermodynamic stability of polymer solutions and the structure and function of biopolymers (proteins, RNA, DNA) under confinement. We explore the influence of nanoparticle crowding on polymer shapes via Monte Carlo simulations and free-volume theory of a coarse-grained model of polymer-nanoparticle mixtures. Exploiting the geometry of random walks, we model polymer coils as effective penetrable ellipsoids, whose shapes fluctuate according to the probability distributions of the eigenvalues of the gyration tensor. Accounting for the entropic cost of a nanoparticle penetrating a larger polymer coil, we compute the crowding-induced shift in the shape distributions, radius of gyration, and asphericity of ideal polymers in a theta solvent. With increased nanoparticle crowding, we find that polymers become more compact (smaller, more spherical), in agreement with predictions of free-volume theory. Our approach can be easily extended to nonideal polymers in good solvents and used to model conformations of biopolymers in crowded environments

  15. Synthetic approaches to uniform polymers.

    Science.gov (United States)

    Ali, Monzur; Brocchini, Steve

    2006-12-30

    Uniform polymers are characterised by a narrow molecular weight distribution (MWD). Uniformity is also defined by chemical structure in respect of (1) monomer orientation, sequence and stereo-regularity, (2) polymer shape and morphology and (3) chemical functionality. The function of natural polymers such as polypeptides and polynucleotides is related to their conformational structure (e.g. folded tertiary structure). This is only possible because of their high degree of uniformity. While completely uniform synthetic polymers are rare, polymers with broad structure and MWD are widely used in medicine and the biomedical sciences. They are integral components in final dosage forms, drug delivery systems (DDS) and in implantable devices. Increasingly uniform polymers are being used to develop more complex medicines (e.g. delivery of biopharmaceuticals, enhanced formulations or DDS's for existing actives). In addition to the function imparted by any new polymer it will be required to meet stringent specifications in terms of cost containment, scalability, biocompatibility and performance. Synthetic polymers with therapeutic activity are also being developed to exploit their polyvalent properties, which is not possible with low molecular weight molecules. There is need to utilise uniform polymers for applications where the polymer may interact with the systemic circulation, tissues or cellular environment. There are also potential applications (e.g. stimuli responsive coatings) where uniform polymers may be used for their more defined property profile. While it is not yet practical to prepare synthetic polymers to the same high degree of uniformity as proteins, nature also effectively utilises many polymers with lower degrees of uniformity (e.g. polysaccharides, poly(amino acids), polyhydroxyalkanoates). In recent years it has become possible to prepare with practical experimental protocols sufficient quantities of polymers that display many aspects of uniformity. This

  16. Biomolecule-functionalized polymer brushes.

    Science.gov (United States)

    Jiang, Hui; Xu, Fu-Jian

    2013-04-21

    Functional polymer brushes have been utilized extensively for the immobilization of biomolecules, which is of crucial importance for the development of biosensors and biotechnology. Recent progress in polymerization methods, in particular surface-initiated atom transfer radical polymerization (ATRP), has provided a unique means for the design and synthesis of new biomolecule-functionalized polymer brushes. This current review summarizes such recent research activities. The different preparation strategies for biomolecule immobilization through polymer brush spacers are described in detail. The functional groups of the polymer brushes used for biomolecule immobilization include epoxide, carboxylic acid, hydroxyl, aldehyde, and amine groups. The recent research activities indicate that functional polymer brushes become versatile and powerful spacers for immobilization of various biomolecules to maximize their functionalities. This review also demonstrates that surface-initiated ATRP is used more frequently than other polymerization methods in the designs of new biomolecule-functionalized polymer brushes.

  17. Claisen thermally rearranged (CTR) polymers

    Science.gov (United States)

    Tena, Alberto; Rangou, Sofia; Shishatskiy, Sergey; Filiz, Volkan; Abetz, Volker

    2016-01-01

    Thermally rearranged (TR) polymers, which are considered the next-generation of membrane materials because of their excellent transport properties and high thermal and chemical stability, are proven to have significant drawbacks because of the high temperature required for the rearrangement and low degree of conversion during this process. We demonstrate that using a [3,3]-sigmatropic rearrangement, the temperature required for the rearrangement of a solid glassy polymer was reduced by 200°C. Conversions of functionalized polyimide to polybenzoxazole of more than 97% were achieved. These highly mechanically stable polymers were almost five times more permeable and had more than two times higher degrees of conversion than the reference polymer treated under the same conditions. Properties of these second-generation TR polymers provide the possibility of preparing efficient polymer membranes in a form of, for example, thin-film composite membranes for various gas and liquid membrane separation applications. PMID:27482538

  18. Electrohydrodynamics in nanochannels coated by mixed polymer brushes: effects of electric field strength and solvent quality

    Science.gov (United States)

    Cao, Qianqian; Tian, Xiu; You, Hao

    2018-04-01

    We examine the electrohydrodynamics in mixed polymer brush-coated nanochannels and the conformational dynamics of grafted polymers using molecular dynamics simulations. Charged (A) and neutral polymers (B) are alternately grafted on the channel surfaces. The effects of the electric field strength and solvent quality are addressed in detail. The dependence of electroosmotic flow characteristics and polymer conformational behavior on the solvent quality is influenced due to the change of the electric field strength. The enhanced electric field induces a collapse of the neutral polymer chains which adopt a highly extended conformation along the flow direction. However, the thickness of the charged polymer layer is affected weakly by the electric field, and even a slight swelling is identified for the A-B attraction case, implying the conformational coupling between two polymer species. Furthermore, the charged polymer chains incline entirely towards the electric field direction oppositely to the flow direction. More importantly, unlike the neutral polymer chains, the shape factor of the charged polymer chains, which is used to describe the overall shape of polymer chains, is reduced significantly with increasing the electric field strength, corresponding to a more coiled structure.

  19. Terminology of Polymers Containing Ionizable or Ionic Groups and of Polymers Containing Ions, VII.3

    Directory of Open Access Journals (Sweden)

    Jarm, V.

    2009-10-01

    Full Text Available The class of ionic polymers has widespread application in many areas of everyday life, in industrial production, and in the processes of living matter. The properties of ionic polymers depend on the polymer structure, and the nature, content, and location of the ionic groups. To clear differences among various ionic polymers, the IUPAC recommendations present 34 definitionsfor the ionomer, polyacid, polybase, polyampholytic polymer, ion-exchange polymer, polybetaine, polyelectrolyte, intrinsically conducting polymer, solid polymer electrolyte, etc

  20. Bank supervision using the Threshold-Minimum Dominating Set

    Science.gov (United States)

    Gogas, Periklis; Papadimitriou, Theophilos; Matthaiou, Maria-Artemis

    2016-06-01

    An optimized, healthy and stable banking system resilient to financial crises is a prerequisite for sustainable growth. Minimization of (a) the associated systemic risk and (b) the propagation of contagion in the case of a banking crisis are necessary conditions to achieve this goal. Central Banks are in charge of this significant undertaking via a close and detailed monitoring of the banking network. In this paper, we propose the use of an auxiliary supervision/monitoring system that is both efficient with respect to the required resources and can promptly identify a set of banks that are in distress so that immediate and appropriate action can be taken by the supervising authority. We use the network defined by the interrelations between banking institutions employing tools from Complex Networks theory for an efficient management of the entire banking network. In doing so, we introduce the Threshold Minimum Dominating Set (T-MDS). The T-MDS is used to identify the smallest and most efficient subset of banks that can be used as (a) sensors of distress of a manifesting banking crisis and (b) provide a path of possible contagion. We propose the use of this method as a supplementary monitoring tool in the arsenal of a Central Bank. Our dataset includes the 122 largest American banks in terms of their interbank loans. The empirical results show that when the T-MDS methodology is applied, we can have an efficient supervision of the whole banking network, by monitoring just a subset of 47 banks.

  1. Verification of Minimum Detectable Activity for Radiological Threat Source Search

    Science.gov (United States)

    Gardiner, Hannah; Myjak, Mitchell; Baciak, James; Detwiler, Rebecca; Seifert, Carolyn

    2015-10-01

    The Department of Homeland Security's Domestic Nuclear Detection Office is working to develop advanced technologies that will improve the ability to detect, localize, and identify radiological and nuclear sources from airborne platforms. The Airborne Radiological Enhanced-sensor System (ARES) program is developing advanced data fusion algorithms for analyzing data from a helicopter-mounted radiation detector. This detector platform provides a rapid, wide-area assessment of radiological conditions at ground level. The NSCRAD (Nuisance-rejection Spectral Comparison Ratios for Anomaly Detection) algorithm was developed to distinguish low-count sources of interest from benign naturally occurring radiation and irrelevant nuisance sources. It uses a number of broad, overlapping regions of interest to statistically compare each newly measured spectrum with the current estimate for the background to identify anomalies. We recently developed a method to estimate the minimum detectable activity (MDA) of NSCRAD in real time. We present this method here and report on the MDA verification using both laboratory measurements and simulated injects on measured backgrounds at or near the detection limits. This work is supported by the US Department of Homeland Security, Domestic Nuclear Detection Office, under competitively awarded contract/IAA HSHQDC-12-X-00376. This support does not constitute an express or implied endorsement on the part of the Gov't.

  2. Solid polymer electrolyte lithium batteries

    Science.gov (United States)

    Alamgir, Mohamed; Abraham, Kuzhikalail M.

    1993-01-01

    This invention pertains to Lithium batteries using Li ion (Li.sup.+) conductive solid polymer electrolytes composed of solvates of Li salts immobilized in a solid organic polymer matrix. In particular, this invention relates to Li batteries using solid polymer electrolytes derived by immobilizing solvates formed between a Li salt and an aprotic organic solvent (or mixture of such solvents) in poly(vinyl chloride).

  3. Vacuum ultraviolet photochemistry of polymers

    International Nuclear Information System (INIS)

    Skurat, Vladimir

    2003-01-01

    The interaction of vacuum UV radiation (wavelength range from 1 to 200 nm) with polymers is interesting for fundamental and applied sciences. This interest is stimulated by various reasons: - Wide applications of polymeric materials in semiconductor technology, where they are used as photoresist materials in combination with VUV light sources (lasers, excimer lamps, synchrotron radiation and others). - Polymers are widely used as spacecraft materials in the last 20 years. On near-Earth orbits, the polymeric materials of spacecraft surfaces are destroyed by solar radiation. - VUV radiation is one of the components of gas discharge plasmas, which are used for treatment of polymer, with the aim of modifying their surface properties. The main features of interaction of VUV radiation with polymers are discussed. The spectra of intrinsic absorption of saturated polymers (polyethylene, polypropylene, polytetrafluoroethylene and others) are situated mainly in the VUV region. The photochemistry of polymers in the VUV region is very different from their photochemistry at wavelengths longer than 200 nm, where the absorption spectra belong to impurities and polymer defects. The polymer photochemistry in the VUV region is wavelength-dependent. At wavelengths longer than about 140 nm, the main role is played by transformations of primary-formed singlet excited molecules. At shorter wavelengths the role of photoionization increases progressively and the main features of VUV photolysis become similar to the picture of radiolysis, with significant contributions of charge pairs and triplet excited molecules. Very important features of VUV light absorption in polymers are high absorption coefficients. Because of this, the surface layers absorb large doses of energy. This leads to very profound transformation of material on the polymer surface. In particular for polymers which are considered destroyed by radiation (for example, perfluoropolymers), this leads to VUV-induced erosion

  4. Planar-Processed Polymer Transistors.

    Science.gov (United States)

    Xu, Yong; Sun, Huabin; Shin, Eul-Yong; Lin, Yen-Fu; Li, Wenwu; Noh, Yong-Young

    2016-10-01

    Planar-processed polymer transistors are proposed where the effective charge injection and the split unipolar charge transport are all on the top surface of the polymer film, showing ideal device characteristics with unparalleled performance. This technique provides a great solution to the problem of fabrication limitations, the ambiguous operating principle, and the performance improvements in practical applications of conjugated-polymer transistors. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. The Distribution of the Sample Minimum-Variance Frontier

    OpenAIRE

    Raymond Kan; Daniel R. Smith

    2008-01-01

    In this paper, we present a finite sample analysis of the sample minimum-variance frontier under the assumption that the returns are independent and multivariate normally distributed. We show that the sample minimum-variance frontier is a highly biased estimator of the population frontier, and we propose an improved estimator of the population frontier. In addition, we provide the exact distribution of the out-of-sample mean and variance of sample minimum-variance portfolios. This allows us t...

  6. Minimum Wages and Teen Employment: A Spatial Panel Approach

    OpenAIRE

    Charlene Kalenkoski; Donald Lacombe

    2011-01-01

    The authors employ spatial econometrics techniques and Annual Averages data from the U.S. Bureau of Labor Statistics for 1990-2004 to examine how changes in the minimum wage affect teen employment. Spatial econometrics techniques account for the fact that employment is correlated across states. Such correlation may exist if a change in the minimum wage in a state affects employment not only in its own state but also in other, neighboring states. The authors show that state minimum wages negat...

  7. 30 CFR 75.1431 - Minimum rope strength.

    Science.gov (United States)

    2010-07-01

    ..., including rotation resistant). For rope lengths less than 3,000 feet: Minimum Value=Static Load×(7.0−0.001L) For rope lengths 3,000 feet or greater: Minimum Value=Static Load×4.0 (b) Friction drum ropes. For rope lengths less than 4,000 feet: Minimum Value=Static Load×(7.0−0.0005L) For rope lengths 4,000 feet...

  8. Minimum Wages and the Distribution of Family Incomes

    OpenAIRE

    Dube, Arindrajit

    2017-01-01

    Using the March Current Population Survey data from 1984 to 2013, I provide a comprehensive evaluation of how minimum wage policies influence the distribution of family incomes. I find robust evidence that higher minimum wages shift down the cumulative distribution of family incomes at the bottom, reducing the share of non-elderly individuals with incomes below 50, 75, 100, and 125 percent of the federal poverty threshold. The long run (3 or more years) minimum wage elasticity of the non-elde...

  9. Resolving Properties of Polymers and Nanoparticle Assembly through Coarse-Grained Computational Studies.

    Energy Technology Data Exchange (ETDEWEB)

    Grest, Gary S. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-09-01

    Coupled length and time scales determine the dynamic behavior of polymers and polymer nanocomposites and underlie their unique properties. To resolve the properties over large time and length scales it is imperative to develop coarse grained models which retain the atomistic specificity. Here we probe the degree of coarse graining required to simultaneously retain significant atomistic details a nd access large length and time scales. The degree of coarse graining in turn sets the minimum length scale instrumental in defining polymer properties and dynamics. Using polyethylene as a model system, we probe how the coarse - graining scale affects the measured dynamics with different number methylene group s per coarse - grained beads. Using these models we simulate polyethylene melts for times over 500 ms to study the viscoelastic properties of well - entangled polymer melts and large nanoparticle assembly as the nanoparticles are driven close enough to form nanostructures.

  10. Minimum Map of Social Institutional Network: a multidimensional strategy for research in Nursing

    Directory of Open Access Journals (Sweden)

    Diene Monique Carlos

    2016-06-01

    Full Text Available Objective To analyze the use of methodological strategies in qualitative research - Minimum Maps of Social Institutional Network, as proposed to understand the phenomena in the multidimensional perspective. Method Methodological theoretical essay in which we aimed to reflect on the use of innovative methodological strategies in nursing research, supported in Complex Paradigm fundamentals. Results The minimum map of Social Institutional External Network aims to identify institutional linkages and gaps for the intervention work of the surveyed institutions. The use of these maps provided important advances in know-how qualitative research in Health and Nursing. Conclusions In this perspective, the use of minimum Social Intitutional Network maps can be stimulated and enhanced to meet the current demands of the contemporary world, particularly for its flexibility in adapting to various research subjects; breadth and depth of discussion; and possibilities with health services.

  11. Parameters Tuning of Model Free Adaptive Control Based on Minimum Entropy

    Institute of Scientific and Technical Information of China (English)

    Chao Ji; Jing Wang; Liulin Cao; Qibing Jin

    2014-01-01

    Dynamic linearization based model free adaptive control(MFAC) algorithm has been widely used in practical systems, in which some parameters should be tuned before it is successfully applied to process industries. Considering the random noise existing in real processes, a parameter tuning method based on minimum entropy optimization is proposed,and the feature of entropy is used to accurately describe the system uncertainty. For cases of Gaussian stochastic noise and non-Gaussian stochastic noise, an entropy recursive optimization algorithm is derived based on approximate model or identified model. The extensive simulation results show the effectiveness of the minimum entropy optimization for the partial form dynamic linearization based MFAC. The parameters tuned by the minimum entropy optimization index shows stronger stability and more robustness than these tuned by other traditional index,such as integral of the squared error(ISE) or integral of timeweighted absolute error(ITAE), when the system stochastic noise exists.

  12. The Need for Higher Minimum Staffing Standards in U.S. Nursing Homes

    Science.gov (United States)

    Harrington, Charlene; Schnelle, John F.; McGregor, Margaret; Simmons, Sandra F.

    2016-01-01

    Many U.S. nursing homes have serious quality problems, in part, because of inadequate levels of nurse staffing. This commentary focuses on two issues. First, there is a need for higher minimum nurse staffing standards for U.S. nursing homes based on multiple research studies showing a positive relationship between nursing home quality and staffing and the benefits of implementing higher minimum staffing standards. Studies have identified the minimum staffing levels necessary to provide care consistent with the federal regulations, but many U.S. facilities have dangerously low staffing. Second, the barriers to staffing reform are discussed. These include economic concerns about costs and a focus on financial incentives. The enforcement of existing staffing standards has been weak, and strong nursing home industry political opposition has limited efforts to establish higher standards. Researchers should study the ways to improve staffing standards and new payment, regulatory, and political strategies to improve nursing home staffing and quality. PMID:27103819

  13. Bistable collective behavior of polymers tethered in a nanopore

    Science.gov (United States)

    Osmanovic, Dino; Bailey, Joe; Harker, Anthony H.; Fassati, Ariberto; Hoogenboom, Bart W.; Ford, Ian J.

    2012-06-01

    Polymer-coated pores play a crucial role in nucleo-cytoplasmic transport and in a number of biomimetic and nanotechnological applications. Here we present Monte Carlo and Density Functional Theory approaches to identify different collective phases of end-grafted polymers in a nanopore and to study their relative stability as a function of intermolecular interactions. Over a range of system parameters that is relevant for nuclear pore complexes, we observe two distinct phases: one with the bulk of the polymers condensed at the wall of the pore, and the other with the polymers condensed along its central axis. The relative stability of these two phases depends on the interpolymer interactions. The existence the two phases suggests a mechanism in which marginal changes in these interactions, possibly induced by nuclear transport receptors, cause the pore to transform between open and closed configurations, which will influence transport through the pore.

  14. Investigating potential physicochemical errors in polymer gel dosimeters

    International Nuclear Information System (INIS)

    Sedaghat, Mahbod; Lepage, Martin; Bujold, Rachel

    2011-01-01

    Measurement errors in polymer gel dosimetry can originate either during irradiation or scanning. One concern related to the exothermic nature of polymerization reaction was that the heat released in polymer gel dosimeters during irradiation modifies their dose response. In this paper, the effect of heat released from the exothermal polymerization reaction on the dose response of a number of dosimeters was studied. In addition, we investigated whether heat-generated geometric distortion existed in newly proposed gel dosimeters that contain highly thermoresponsive polymers. Our results suggest that despite a significant internal temperature increase in some gel compositions, their dose responses are not affected when oxygen is well expelled mechanically from the gel mixture. We also report on significant pre-irradiation instability in some recently developed polymer gel dosimeters but that geometric distortions were not observed. Data obtained by a set of small calibration vials are compared to those obtained from larger phantoms, and potential physicochemical causes of deviations between them are identified.

  15. Investigating potential physicochemical errors in polymer gel dosimeters

    Energy Technology Data Exchange (ETDEWEB)

    Sedaghat, Mahbod; Lepage, Martin [Centre d' imagerie moleculaire de Sherbrooke, Departement de medecine nucleaire et radiobiologie, Universite de Sherbrooke, Sherbrooke, QC (Canada); Bujold, Rachel, E-mail: martin.lepage@usherbrooke.ca [Service de radio-oncologie, Centre hospitalier universitaire de Sherbrooke, Sherbrooke, QC (Canada)

    2011-09-21

    Measurement errors in polymer gel dosimetry can originate either during irradiation or scanning. One concern related to the exothermic nature of polymerization reaction was that the heat released in polymer gel dosimeters during irradiation modifies their dose response. In this paper, the effect of heat released from the exothermal polymerization reaction on the dose response of a number of dosimeters was studied. In addition, we investigated whether heat-generated geometric distortion existed in newly proposed gel dosimeters that contain highly thermoresponsive polymers. Our results suggest that despite a significant internal temperature increase in some gel compositions, their dose responses are not affected when oxygen is well expelled mechanically from the gel mixture. We also report on significant pre-irradiation instability in some recently developed polymer gel dosimeters but that geometric distortions were not observed. Data obtained by a set of small calibration vials are compared to those obtained from larger phantoms, and potential physicochemical causes of deviations between them are identified.

  16. Further investigations of the properties of polymer modified cements

    International Nuclear Information System (INIS)

    Johnson, D.I.

    1988-05-01

    This report concludes the work done on behalf of the Department of the Environment on polymer modified cement composites. Topics covered include: the influence of cure schedule on flexural properties, observation of the onset and cracking during flexural testing, measurement of water permeability and caesium diffusion rates, and the use of Back Scattered Electron Imaging to identify the polymer phase. The properties of epoxide resin modified cements in the previous report were disappointing. Air entrainment of the mixing stage was a likely cause of the poor performance of these products and procedures to overcome this problem were devised. The range of polymer additives investigated was broadened by the inclusion of modified acrylic latexes and a polymensable acrylate resin additive. Properties for OPC and 9 BFS: 1 OPC cements are compared and the modification of properties achieved by polymer additions to both cement systems is discussed. (author)

  17. Life-cycle analysis of product integrated polymer solar cells

    DEFF Research Database (Denmark)

    Espinosa Martinez, Nieves; García-Valverde, Rafael; Krebs, Frederik C

    2011-01-01

    A life cycle analysis (LCA) on a product integrated polymer solar module is carried out in this study. These assessments are well-known to be useful in developmental stages of a product in order to identify the bottlenecks for the up-scaling in its production phase for several aspects spanning from...... economics through design to functionality. An LCA study was performed to quantify the energy use and greenhouse gas (GHG) emissions from electricity use in the manufacture of a light-weight lamp based on a plastic foil, a lithium-polymer battery, a polymer solar cell, printed circuitry, blocking diode......, switch and a white light emitting semiconductor diode. The polymer solar cell employed in this prototype presents a power conversion efficiency in the range of 2 to 3% yielding energy payback times (EPBT) in the range of 1.3–2 years. Based on this it is worthwhile to undertake a life-cycle study...

  18. Chemical modification and blending of polymers in an extruder reactor

    International Nuclear Information System (INIS)

    Prut, Eduard V; Zelenetskii, Alexandr N

    2001-01-01

    Chemical modification and blending of polymers in an extruder reactor are discussed. Relationships between the parameters affecting the reaction kinetics, viz., mixing time, duration of a chemical reaction and the residence time of the system in the extruder reactor, and the structure of the materials produced are analysed. The mechanisms of (i) grafting of low-molecular-mass compounds onto polymers; (ii) reactions between terminal groups of different polymers and (iii) transesterification and interchange reactions are considered. The factors affecting the mechanism of dynamic vulcanisation and the properties of thermoplastic elastomers are identified. Solid-phase reactions of polysaccharides in an extruder are discussed. The priority aspects of studies on the chemical modification and blending of polymers are noted. The bibliography includes 90 references.

  19. Minimum Distance Estimation on Time Series Analysis With Little Data

    National Research Council Canada - National Science Library

    Tekin, Hakan

    2001-01-01

    .... Minimum distance estimation has been demonstrated better standard approaches, including maximum likelihood estimators and least squares, in estimating statistical distribution parameters with very small data sets...

  20. 30 CFR 57.19021 - Minimum rope strength.

    Science.gov (United States)

    2010-07-01

    ... feet: Minimum Value=Static Load×(7.0−0.001L) For rope lengths 3,000 feet or greater: Minimum Value=Static Load×4.0. (b) Friction drum ropes. For rope lengths less than 4,000 feet: Minimum Value=Static Load×(7.0−0.0005L) For rope lengths 4,000 feet or greater: Minimum Value=Static Load×5.0. (c) Tail...

  1. 30 CFR 77.1431 - Minimum rope strength.

    Science.gov (United States)

    2010-07-01

    ... feet: Minimum Value=Static Load×(7.0−0.001L) For rope lengths 3,000 feet or greater: Minimum Value=Static Load×4.0 (b) Friction drum ropes. For rope lengths less than 4,000 feet: Minimum Value=Static Load×(7.0−0.0005L) For rope lengths 4,000 feet or greater: Minimum Value=Static Load×5.0 (c) Tail ropes...

  2. Decision trees with minimum average depth for sorting eight elements

    KAUST Repository

    AbouEisha, Hassan M.

    2015-11-19

    We prove that the minimum average depth of a decision tree for sorting 8 pairwise different elements is equal to 620160/8!. We show also that each decision tree for sorting 8 elements, which has minimum average depth (the number of such trees is approximately equal to 8.548×10^326365), has also minimum depth. Both problems were considered by Knuth (1998). To obtain these results, we use tools based on extensions of dynamic programming which allow us to make sequential optimization of decision trees relative to depth and average depth, and to count the number of decision trees with minimum average depth.

  3. Conjugated Polymers for Energy Production

    DEFF Research Database (Denmark)

    Livi, Francesco

    This dissertation is aimed at developing materials for flexible, large area, ITO-free polymer solar cells (PSCs) fully printed under ambient conditions. A large screening of conjugated polymers, both novel and well-known materials, has been carried out in order to find suitable candidates...... polymerization method for industrial production of polymers. Several DArP protocols have been employed for the synthesis of PPDTBT leading to polymers with high structural regularity and photovoltaic performances comparable with the same materials synthesized via Stille cross-coupling polymerization...

  4. Multifunctional Polymer/Inorganic Nanocomposites

    National Research Council Canada - National Science Library

    Manias, E

    2003-01-01

    ... in multifunctional nanocomposite materials. Understanding the structure/property relations in polymer/clay nanocomposites is of great importance in designing materials with desired sets of properties...

  5. Wear of polymers and composites

    CERN Document Server

    Abdelbary, Ahmed

    2015-01-01

    In the field of tribology, the wear behaviour of polymers and composite materials is considered a highly non-linear phenomenon. Wear of Polymers and Composites introduces fundamentals of polymers and composites tribology. The book suggests a new approach to explore the effect of applied load and surface defects on the fatigue wear behaviour of polymers, using a new tribometer and thorough experiments. It discusses effects of surface cracks, under different static and cyclic loading parameters on wear, and presents an intelligent algorithm, in the form of a neural network, to map the relations

  6. Application of Composite Polymer Electrolytes

    National Research Council Canada - National Science Library

    Scrosati, Bruno

    2001-01-01

    ...)PEO-based composite polymer electrolytes, by a series of specifically addressed electrochemical tests which included the determination of the conductivity and of the lithium transference number...

  7. Sustainable polymers from renewable resources.

    Science.gov (United States)

    Zhu, Yunqing; Romain, Charles; Williams, Charlotte K

    2016-12-14

    Renewable resources are used increasingly in the production of polymers. In particular, monomers such as carbon dioxide, terpenes, vegetable oils and carbohydrates can be used as feedstocks for the manufacture of a variety of sustainable materials and products, including elastomers, plastics, hydrogels, flexible electronics, resins, engineering polymers and composites. Efficient catalysis is required to produce monomers, to facilitate selective polymerizations and to enable recycling or upcycling of waste materials. There are opportunities to use such sustainable polymers in both high-value areas and in basic applications such as packaging. Life-cycle assessment can be used to quantify the environmental benefits of sustainable polymers.

  8. Phenomenology of polymer solution dynamics

    National Research Council Canada - National Science Library

    Phillies, George D. J

    2011-01-01

    ... solutions, not dilute solutions or polymer melts. From centrifugation and solvent dynamics to viscosity and diffusion, experimental measurements and their quantitative representations are the core of the discussion...

  9. Small angle scattering and polymers

    International Nuclear Information System (INIS)

    Cotton, J.P.

    1996-01-01

    The determination of polymer structure is a problem of interest for both statistical physics and industrial applications. The average polymer structure is defined. Then, it is shown why small angle scattering, associated with isotopic substitution, is very well suited to the measurement of the chain conformation. The corresponding example is the old, but pedagogic, measurement of the chain form factor in the polymer melt. The powerful contrast variation method is illustrated by a recent determination of the concentration profile of a polymer interface. (author) 12 figs., 48 refs

  10. Polymer Processing and Characterization Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The purpose is to process and evaluate polymers for use in nonlinear optical, conductive and structural Air Force applications. Primary capabilities are extrusion of...

  11. Control of polymer network topology in semi-batch systems

    Science.gov (United States)

    Wang, Rui; Olsen, Bradley; Johnson, Jeremiah

    Polymer networks invariably possess topological defects: loops of different orders. Since small loops (primary loops and secondary loops) both lower the modulus of network and lead to stress concentration that causes material failure at low deformation, it is desirable to greatly reduce the loop fraction. We have shown that achieving loop fraction close to zero is extremely difficult in the batch process due to the slow decay of loop fraction with the polymer concentration and chain length. Here, we develop a modified kinetic graph theory that can model network formation reactions in semi-batch systems. We demonstrate that the loop fraction is not sensitive to the feeding policy if the reaction volume maintains constant during the network formation. However, if we initially put concentrated solution of small junction molecules in the reactor and continuously adding polymer solutions, the fractions of both primary loop and higher-order loops will be significantly reduced. There is a limiting value (nonzero) of loop fraction that can be achieved in the semi-batch system in condition of extremely slow feeding rate. This minimum loop fraction only depends on a single dimensionless variable, the product of concentration and with single chain pervaded volume, and defines an operating zone in which the loop fraction of polymer networks can be controlled through adjusting the feeding rate of the semi-batch process.

  12. Radiation cross-linking of PTC conductive polymers

    International Nuclear Information System (INIS)

    Doljack, F.A.; Jacobs, S.M.; Taylor, J.M.; McTavish, M.S.

    1982-01-01

    An electrical device comprising a PTC conductive polymer is irradiated so that it is very highly cross-linked. A dosage of at least 50 Mrads, preferably at least 80 Mrads, especially at least 120 Mrads is used except that where the device includes planar electrodes which are present during irradiation the minimum dose is 120 Mrads. In this way, for example, it is possible to make a circuit protection device which will continue to provide effective protection even after repeated exposure to a voltage of 200 volts. A PTC protection device may be produced by moulding carbon loaded polymer round three electrodes the centre one of which is then removed to leave an aperture between the other two electrodes. (author)

  13. Impact of cigarette minimum price laws on the retail price of cigarettes in the USA.

    Science.gov (United States)

    Tynan, Michael A; Ribisl, Kurt M; Loomis, Brett R

    2013-05-01

    Cigarette price increases prevent youth initiation, reduce cigarette consumption and increase the number of smokers who quit. Cigarette minimum price laws (MPLs), which typically require cigarette wholesalers and retailers to charge a minimum percentage mark-up for cigarette sales, have been identified as an intervention that can potentially increase cigarette prices. 24 states and the District of Columbia have cigarette MPLs. Using data extracted from SCANTRACK retail scanner data from the Nielsen company, average cigarette prices were calculated for designated market areas in states with and without MPLs in three retail channels: grocery stores, drug stores and convenience stores. Regression models were estimated using the average cigarette pack price in each designated market area and calendar quarter in 2009 as the outcome variable. The average difference in cigarette pack prices are 46 cents in the grocery channel, 29 cents in the drug channel and 13 cents in the convenience channel, with prices being lower in states with MPLs for all three channels. The findings that MPLs do not raise cigarette prices could be the result of a lack of compliance and enforcement by the state or could be attributed to the minimum state mark-up being lower than the free-market mark-up for cigarettes. Rather than require a minimum mark-up, which can be nullified by promotional incentives and discounts, states and countries could strengthen MPLs by setting a simple 'floor price' that is the true minimum price for all cigarettes or could prohibit discounts to consumers and retailers.

  14. Training and minimum wages: first evidence from the introduction of the minimum wage in Germany

    Directory of Open Access Journals (Sweden)

    Lutz Bellmann

    2017-06-01

    Full Text Available Abstract We analyze the short-run impact of the introduction of the new statutory minimum wage in Germany on further training at the workplace level. Applying difference-in-difference methods to data from the IAB Establishment Panel, we do not find a reduction in the training incidence but a slight reduction in the intensity of training at treated establishments. Effect heterogeneities reveal that the negative impact is mostly driven by employer-financed training. On the worker level, we observe a reduction of training for medium- and high-skilled employees but no significant effects on the training of low-skilled employees.

  15. Minimum weight protection - Gradient method; Protection de poids minimum - Methode du gradient

    Energy Technology Data Exchange (ETDEWEB)

    Danon, R.

    1958-12-15

    After having recalled that, when considering a mobile installation, total weight has a crucial importance, and that, in the case of a nuclear reactor, a non neglectable part of weight is that of protection, this note presents an iterative method which results, for a given protection, to a configuration with a minimum weight. After a description of the problem, the author presents the theoretical formulation of the gradient method as it is applied to the concerned case. This application is then discussed, as well as its validity in terms of convergence and uniqueness. Its actual application is then reported, and possibilities of practical applications are evoked.

  16. Topology of polymer chains under nanoscale confinement.

    Science.gov (United States)

    Satarifard, Vahid; Heidari, Maziar; Mashaghi, Samaneh; Tans, Sander J; Ejtehadi, Mohammad Reza; Mashaghi, Alireza

    2017-08-24

    Spatial confinement limits the conformational space accessible to biomolecules but the implications for bimolecular topology are not yet known. Folded linear biopolymers can be seen as molecular circuits formed by intramolecular contacts. The pairwise arrangement of intra-chain contacts can be categorized as parallel, series or cross, and has been identified as a topological property. Using molecular dynamics simulations, we determine the contact order distributions and topological circuits of short semi-flexible linear and ring polymer chains with a persistence length of l p under a spherical confinement of radius R c . At low values of l p /R c , the entropy of the linear chain leads to the formation of independent contacts along the chain and accordingly, increases the fraction of series topology with respect to other topologies. However, at high l p /R c , the fraction of cross and parallel topologies are enhanced in the chain topological circuits with cross becoming predominant. At an intermediate confining regime, we identify a critical value of l p /R c , at which all topological states have equal probability. Confinement thus equalizes the probability of more complex cross and parallel topologies to the level of the more simple, non-cooperative series topology. Moreover, our topology analysis reveals distinct behaviours for ring- and linear polymers under weak confinement; however, we find no difference between ring- and linear polymers under strong confinement. Under weak confinement, ring polymers adopt parallel and series topologies with equal likelihood, while linear polymers show a higher tendency for series arrangement. The radial distribution analysis of the topology reveals a non-uniform effect of confinement on the topology of polymer chains, thereby imposing more pronounced effects on the core region than on the confinement surface. Additionally, our results reveal that over a wide range of confining radii, loops arranged in parallel and cross

  17. Use of Atomic Oxygen for Increased Water Contact Angles of Various Polymers for Biomedical Applications

    Science.gov (United States)

    deGroh, Kim; Berger, Lauren; Roberts, Lily

    2009-01-01

    The purpose of this study was to determine the effect of atomic oxygen (AO) exposure on the hydrophilicity of nine different polymers for biomedical applications. Atomic oxygen treatment can alter the chemistry and morphology of polymer surfaces, which may increase the adhesion and spreading of cells on Petri dishes and enhance implant growth. Therefore, nine different polymers were exposed to atomic oxygen and water-contact angle, or hydrophilicity, was measured after exposure. To determine whether hydrophilicity remains static after initial atomic oxygen exposure, or changes with higher fluence exposures, the contact angles between the polymer and water droplet placed on the polymer s surface were measured versus AO fluence. The polymers were exposed to atomic oxygen in a 100-W, 13.56-MHz radio frequency (RF) plasma asher, and the treatment was found to significantly alter the hydrophilicity of non-fluorinated polymers. Pristine samples were compared with samples that had been exposed to AO at various fluence levels. Minimum and maximum fluences for the ashing trials were set based on the effective AO erosion of a Kapton witness coupon in the asher. The time intervals for ashing were determined by finding the logarithmic values of the minimum and maximum fluences. The difference of these two values was divided by the desired number of intervals (ideally 10). The initial desired fluence was then multiplied by this result (2.37), as was each subsequent desired fluence. The flux in the asher was determined to be approximately 3.0 x 10(exp 15) atoms/sq cm/sec, and each polymer was exposed to a maximum fluence of 5.16 x 10(exp 20) atoms/sq cm.

  18. Clickable antifouling polymer brushes for polymer pen lithography

    Czech Academy of Sciences Publication Activity Database

    Bog, U.; de los Santos Pereira, Andres; Mueller, S. L.; Havenridge, S.; Parrillo, Viviana; Bruns, M.; Holmes, A. E.; Rodriguez-Emmenegger, C.; Fuchs, H.; Hirtz, M.

    2017-01-01

    Roč. 9, č. 13 (2017), s. 12109-12117 ISSN 1944-8244 R&D Projects: GA ČR(CZ) GJ15-09368Y Institutional support: RVO:61389013 Keywords : antifouling * biofunctional interfaces * polymer brushes Subject RIV: CD - Macromolecular Chemistry OBOR OECD: Polymer science Impact factor: 7.504, year: 2016

  19. Enhancement of Polymer Cytocompatibility by Nanostructuring of Polymer Surface

    Czech Academy of Sciences Publication Activity Database

    Slepička, P.; Kasálková-Slepičková, N.; Bačáková, Lucie; Kolská, Z.; Švorčík, V.

    2012-01-01

    Roč. 2012, č. 2012 (2012), ID527403 ISSN 1687-4110 R&D Projects: GA ČR(CZ) GBP108/12/G108 Institutional support: RVO:67985823 Keywords : polymer cytocompatibility * polymer surface * nanotechnology Subject RIV: EI - Biotechnology ; Bionics Impact factor: 1.547, year: 2012

  20. Radiation Synthesis of Superabsorbent Polymers Based on Natural Polymers

    International Nuclear Information System (INIS)

    Sen, Murat; Hayrabolulu, Hande

    2010-01-01

    The objectives of proposed research contract were first synthesize superabsorbent polymers based on natural polymers to be used as disposable diapers and soil conditioning materials in agriculture, horticulture and other super adsorbent using industries. We have planned to use the natural polymers; locust beam gum, tara gum, guar gum and sodium alginate on the preparation of natural superabsorbent polymers(SAP). The aqueous solution of natural polymers and their blends with trace amount of monomer and cross-linking agents will be irradiated in paste like conditions by gamma rays for the preparation of cross-linked superabsorbent systems. The water absorption and deswellling capacity of prepared super adsorbents and retention capacity, absorbency under load, suction power, swelling pressure and pet-rewet properties will be determined. Use of these materials instead of synthetic super absorbents will be examined by comparing the performance of finished products. The experimental studies achieved in the second year of project mainly on the effect of radiation on the chemistry of sodium alginate polymers in different irradiation conditions and structure-property relationship particularly with respect to radiation induced changes on the molecular weight of natural polymers and preliminary studies on the synthesis of natural-synthetic hydride super adsorbent polymers were given in details

  1. Polymer Crowding in Confined Polymer-Nanoparticle Mixtures

    Science.gov (United States)

    Davis, Wyatt J.; Denton, Alan R.

    Crowding can influence the conformations and thus functionality of macromolecules in quasi-two-dimensional environments, such as DNA or proteins confined to a cell membrane. We explore such crowding within a model of polymers as penetrable ellipses, whose shapes are governed by the statistics of a 2D random walk. The principal radii of the polymers fluctuate according to probability distributions of the eigenvalues of the gyration tensor. Within this coarse-grained model, we perform Monte Carlo simulations of mixtures of polymers and hard nanodisks, including trial changes in polymer conformation (shape and orientation). Penetration of polymers by nanodisks is incorporated with a free energy cost predicted by polymer field theory. Over ranges of size ratio and nanodisk density, we analyze the influence of crowding on polymer shape by computing eigenvalue distributions, mean radius of gyration, and mean asphericity of the polymer. We compare results with predictions of free-volume theory and with corresponding results in three dimensions. Our approach may help to interpret recent (and motivate future) experimental studies of biopolymers interacting with cell membranes, with relevance for drug delivery and gene therapy. This work was supported by the National Science Foundation under Grant No. DMR-1106331.

  2. Polymer solidification national program

    International Nuclear Information System (INIS)

    Kalb, P.D.; Colombo, P.

    1993-04-01

    Brookhaven National Laboratory (BNL) has developed several new and innovative polymer processes for the solidification of low-level radioactive, hazardous and mixed wastes streams. Polyethylene and modified sulfur cement solidification technologies have undergone steady, gradual development at BNL over the past nine years. During this time they have progressed through each of the stages necessary for logical technology maturation: from process conception, parameter optimization, waste form testing, evaluation of long-term durability, economic analysis, and scale-up feasibility. This technology development represents a significant investment which can potentially provide DOE with both short- and long-term savings

  3. Monte Carlo simulations of confined polymer systems

    NARCIS (Netherlands)

    Vliet, Johannes Henricus van

    1991-01-01

    This thesis considers confined polymer systems. These systems are of considerable interest, e.g., thin polymer films, chromotography of polymer solutions, drag reduction, enhanced oil recovery, stabilization of colloidal dispersions, lubrication and biolubrication. The method used to study these

  4. Processing of polymers using reactive solvents

    NARCIS (Netherlands)

    Lemstra, P.J.; Kurja, J.; Meijer, H.E.H.; Meijer, H.E.H.

    1997-01-01

    A review with many refs. on processing of polymers using reactive solvents including classification of synthetic polymers, guidelines for the selection of reactive solvents, basic aspects of processing, examples of intractable and tractable polymer/reactive solvent system

  5. Effect of sodium aromatic sulfonate group in anionic polymer dispersant on the viscosity of coal-water mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Toshio Kakui; Hidehiro Kamiya [Lion Corporation, Tokyo (Japan). Chemicals Research Laboratories, Chemicals Division

    2004-06-01

    This paper focused on the effect of sodium aromatic sulfonate in anionic polymer dispersants on the viscosity of coal-water mixtures (CWMs) with a Tatung coal powder. To determine the optimum molecular structure of a polymer dispersant for the minimum viscosity of a CWM, various anionic co-polymers with different hydrophilic and hydrophobic groups or different molecular weights were prepared, using various types of monomers. Anionic co-polymers with sodium aromatic sulfonate, such as sodium styrene-sulfonate and sodium naphthalene-sulfonate, reduced the viscosity of dense CWMs. In particular, a co-polymer of sodium styrene-sulfonate and sodium acrylate with a molar ratio of 70:30 and a molecular weight of {approximately} 10 000 gave the minimum viscosity of a 70 wt % CWM. To obtain a low viscosity for a CWM, a large electrostatic repulsive force with an absolute value of the zeta potential of the coal particles of {gt} 70 mV and {gt} 6.5 mg/g of adsorbed polymer on the coal surface were needed. The mixture of sodium polystyrene-sulfonate and sodium polyacrylate with a weight ratio of 50:50 also gave a low viscosity of 70 wt % CWM. On the basis of the results, the adsorption behavior of polymer dispersants on the coal surface is examined by measuring the wettability of coal powder pellets. 27 refs., 8 figs., 3 tabs.

  6. Effect of polymer additives on transition in pipe flow

    Energy Technology Data Exchange (ETDEWEB)

    Castro, W; Squire, W

    1967-09-01

    Small amounts of long-chain, water-soluble polymers have a marked effect on turbulent flow resulting in appreciable reduction of turbulent friction. The maximum reduction in pipe flow resistance is obtained at such low concentrations that the density and viscosity are not altered appreciably. The minimum friction curve varies as Re-2/3 and appears to be the same for all effective additives tested. The transition process is affected by these additives. Quantitative results are presented showing a reduction in the intensity of the turbulent flashes and the fraction of the time the flow is turbulent at a given Reynolds number. (13 refs.)

  7. MEDOF - MINIMUM EUCLIDEAN DISTANCE OPTIMAL FILTER

    Science.gov (United States)

    Barton, R. S.

    1994-01-01

    The Minimum Euclidean Distance Optimal Filter program, MEDOF, generates filters for use in optical correlators. The algorithm implemented in MEDOF follows theory put forth by Richard D. Juday of NASA/JSC. This program analytically optimizes filters on arbitrary spatial light modulators such as coupled, binary, full complex, and fractional 2pi phase. MEDOF optimizes these modulators on a number of metrics including: correlation peak intensity at the origin for the centered appearance of the reference image in the input plane, signal to noise ratio including the correlation detector noise as well as the colored additive input noise, peak to correlation energy defined as the fraction of the signal energy passed by the filter that shows up in the correlation spot, and the peak to total energy which is a generalization of PCE that adds the passed colored input noise to the input image's passed energy. The user of MEDOF supplies the functions that describe the following quantities: 1) the reference signal, 2) the realizable complex encodings of both the input and filter SLM, 3) the noise model, possibly colored, as it adds at the reference image and at the correlation detection plane, and 4) the metric to analyze, here taken to be one of the analytical ones like SNR (signal to noise ratio) or PCE (peak to correlation energy) rather than peak to secondary ratio. MEDOF calculates filters for arbitrary modulators and a wide range of metrics as described above. MEDOF examines the statistics of the encoded input image's noise (if SNR or PCE is selected) and the filter SLM's (Spatial Light Modulator) available values. These statistics are used as the basis of a range for searching for the magnitude and phase of k, a pragmatically based complex constant for computing the filter transmittance from the electric field. The filter is produced for the mesh points in those ranges and the value of the metric that results from these points is computed. When the search is concluded, the

  8. Six months into Myanmar's minimum wage: Reflecting on progress ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2016-04-25

    Apr 25, 2016 ... Participants examined recent results from an IDRC-funded enterprise survey, ... of a minimum wage, and how they have coped with the new situation.” ... Debate on the impact of minimum wages on employment continues ...

  9. The impact of minimum wages on youth employment in Portugal

    NARCIS (Netherlands)

    S.C. Pereira

    2003-01-01

    textabstractFrom January 1, 1987, the legal minimum wage for workers aged 18 and 19 in Portugal was uprated to the full adult rate, generating a 49.3% increase between 1986 and 1987 in the legal minimum wage for this age group. This shock is used as a ?natural experiment? to evaluate the impact of

  10. The Impact Of Minimum Wage On Employment Level And ...

    African Journals Online (AJOL)

    This research work has been carried out to analyze the critical impact of minimum wage of employment level and productivity in Nigeria. A brief literature on wage and its determination was highlighted. Models on minimum wage effect are being look into. This includes research work done by different economist analyzing it ...

  11. 42 CFR 84.134 - Respirator containers; minimum requirements.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Respirator containers; minimum requirements. 84.134... Respirators § 84.134 Respirator containers; minimum requirements. Supplied-air respirators shall be equipped with a substantial, durable container bearing markings which show the applicant's name, the type and...

  12. 42 CFR 84.1134 - Respirator containers; minimum requirements.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Respirator containers; minimum requirements. 84... Combination Gas Masks § 84.1134 Respirator containers; minimum requirements. (a) Except as provided in paragraph (b) of this section each respirator shall be equipped with a substantial, durable container...

  13. 42 CFR 84.197 - Respirator containers; minimum requirements.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Respirator containers; minimum requirements. 84.197... Cartridge Respirators § 84.197 Respirator containers; minimum requirements. Respirators shall be equipped with a substantial, durable container bearing markings which show the applicant's name, the type and...

  14. 42 CFR 84.174 - Respirator containers; minimum requirements.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Respirator containers; minimum requirements. 84.174... Air-Purifying Particulate Respirators § 84.174 Respirator containers; minimum requirements. (a) Except..., durable container bearing markings which show the applicant's name, the type of respirator it contains...

  15. 42 CFR 84.74 - Apparatus containers; minimum requirements.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Apparatus containers; minimum requirements. 84.74...-Contained Breathing Apparatus § 84.74 Apparatus containers; minimum requirements. (a) Apparatus may be equipped with a substantial, durable container bearing markings which show the applicant's name, the type...

  16. 14 CFR 91.155 - Basic VFR weather minimums.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Basic VFR weather minimums. 91.155 Section...) AIR TRAFFIC AND GENERAL OPERATING RULES GENERAL OPERATING AND FLIGHT RULES Flight Rules Visual Flight Rules § 91.155 Basic VFR weather minimums. (a) Except as provided in paragraph (b) of this section and...

  17. 42 CFR 422.382 - Minimum net worth amount.

    Science.gov (United States)

    2010-10-01

    ... that CMS considers appropriate to reduce, control or eliminate start-up administrative costs. (b) After... section. (c) Calculation of the minimum net worth amount—(1) Cash requirement. (i) At the time of application, the organization must maintain at least $750,000 of the minimum net worth amount in cash or cash...

  18. 7 CFR 1610.5 - Minimum Bank loan.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 11 2010-01-01 2010-01-01 false Minimum Bank loan. 1610.5 Section 1610.5 Agriculture Regulations of the Department of Agriculture (Continued) RURAL TELEPHONE BANK, DEPARTMENT OF AGRICULTURE LOAN POLICIES § 1610.5 Minimum Bank loan. A Bank loan will not be made unless the applicant qualifies for a Bank...

  19. 5 CFR 551.601 - Minimum age standards.

    Science.gov (United States)

    2010-01-01

    ... ADMINISTRATION UNDER THE FAIR LABOR STANDARDS ACT Child Labor § 551.601 Minimum age standards. (a) 16-year... subject to its child labor provisions, with certain exceptions not applicable here. (b) 18-year minimum... occupation found and declared by the Secretary of Labor to be particularly hazardous for the employment of...

  20. 76 FR 15368 - Minimum Security Devices and Procedures

    Science.gov (United States)

    2011-03-21

    ... DEPARTMENT OF THE TREASURY Office of Thrift Supervision Minimum Security Devices and Procedures... concerning the following information collection. Title of Proposal: Minimum Security Devices and Procedures... security devices and procedures to discourage robberies, burglaries, and larcenies, and to assist in the...

  1. 76 FR 30243 - Minimum Security Devices and Procedures

    Science.gov (United States)

    2011-05-24

    ... DEPARTMENT OF THE TREASURY Office of Thrift Supervision Minimum Security Devices and Procedures.... Title of Proposal: Minimum Security Devices and Procedures. OMB Number: 1550-0062. Form Number: N/A... respect to the installation, maintenance, and operation of security devices and procedures to discourage...

  2. 12 CFR 567.2 - Minimum regulatory capital requirement.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 5 2010-01-01 2010-01-01 false Minimum regulatory capital requirement. 567.2... Regulatory Capital Requirements § 567.2 Minimum regulatory capital requirement. (a) To meet its regulatory capital requirement a savings association must satisfy each of the following capital standards: (1) Risk...

  3. Minimum bias measurement at 13 TeV

    CERN Document Server

    Orlando, Nicola; The ATLAS collaboration

    2017-01-01

    The modelling of Minimum Bias (MB) is a crucial ingredient to learn about the description of soft QCD processes and to simulate the environment at the LHC with many concurrent pp interactions (pile-up). We summarise the ATLAS minimum bias measurements with proton-proton collision at 13 TeV center-of-mass-energy at the Large Hadron Collider.

  4. Solving the minimum flow problem with interval bounds and flows

    Indian Academy of Sciences (India)

    ... with crisp data. In this paper, the idea of Ghiyasvand was extended for solving the minimum flow problem with interval-valued lower, upper bounds and flows. This problem can be solved using two minimum flow problems with crisp data. Then, this result is extended to networks with fuzzy lower, upper bounds and flows.

  5. 47 CFR 25.205 - Minimum angle of antenna elevation.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Minimum angle of antenna elevation. 25.205 Section 25.205 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Technical Standards § 25.205 Minimum angle of antenna elevation. (a) Earth station...

  6. 77 FR 43196 - Minimum Internal Control Standards and Technical Standards

    Science.gov (United States)

    2012-07-24

    ... NATIONAL INDIAN GAMING COMMISSION 25 CFR Parts 543 and 547 Minimum Internal Control Standards [email protected] . SUPPLEMENTARY INFORMATION: Part 543 addresses minimum internal control standards (MICS) for Class II gaming operations. The regulations require tribes to establish controls and implement...

  7. 12 CFR 3.6 - Minimum capital ratios.

    Science.gov (United States)

    2010-01-01

    ... should have well-diversified risks, including no undue interest rate risk exposure; excellent control... 12 Banks and Banking 1 2010-01-01 2010-01-01 false Minimum capital ratios. 3.6 Section 3.6 Banks and Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE TREASURY MINIMUM CAPITAL RATIOS; ISSUANCE...

  8. Minimum Competencies in Undergraduate Motor Development. Guidance Document

    Science.gov (United States)

    National Association for Sport and Physical Education, 2004

    2004-01-01

    The minimum competency guidelines in Motor Development described herein at the undergraduate level may be gained in one or more motor development course(s) or through other courses provided in an undergraduate curriculum. The minimum guidelines include: (1) Formulation of a developmental perspective; (2) Knowledge of changes in motor behavior…

  9. 30 CFR 77.606-1 - Rubber gloves; minimum requirements.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Rubber gloves; minimum requirements. 77.606-1... COAL MINES Trailing Cables § 77.606-1 Rubber gloves; minimum requirements. (a) Rubber gloves (lineman's gloves) worn while handling high-voltage trailing cables shall be rated at least 20,000 volts and shall...

  10. 42 CFR 84.117 - Gas mask containers; minimum requirements.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Gas mask containers; minimum requirements. 84.117... SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Gas Masks § 84.117 Gas mask containers; minimum requirements. (a) Gas masks shall be equipped with a substantial...

  11. Decision trees with minimum average depth for sorting eight elements

    KAUST Repository

    AbouEisha, Hassan M.; Chikalov, Igor; Moshkov, Mikhail

    2015-01-01

    We prove that the minimum average depth of a decision tree for sorting 8 pairwise different elements is equal to 620160/8!. We show also that each decision tree for sorting 8 elements, which has minimum average depth (the number of such trees

  12. 30 CFR 18.97 - Inspection of machines; minimum requirements.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Inspection of machines; minimum requirements... TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Field Approval of Electrically Operated Mining Equipment § 18.97 Inspection of machines; minimum...

  13. 12 CFR 615.5330 - Minimum surplus ratios.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Minimum surplus ratios. 615.5330 Section 615.5330 Banks and Banking FARM CREDIT ADMINISTRATION FARM CREDIT SYSTEM FUNDING AND FISCAL AFFAIRS, LOAN POLICIES AND OPERATIONS, AND FUNDING OPERATIONS Surplus and Collateral Requirements § 615.5330 Minimum...

  14. 19 CFR 144.33 - Minimum quantities to be withdrawn.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 2 2010-04-01 2010-04-01 false Minimum quantities to be withdrawn. 144.33 Section 144.33 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT... Warehouse § 144.33 Minimum quantities to be withdrawn. Unless by special authority of the Commissioner of...

  15. The impact of minimum wage adjustments on Vietnamese wage inequality

    DEFF Research Database (Denmark)

    Hansen, Henrik; Rand, John; Torm, Nina

    Using Vietnamese Labour Force Survey data we analyse the impact of minimum wage changes on wage inequality. Minimum wages serve to reduce local wage inequality in the formal sectors by decreasing the gap between the median wages and the lower tail of the local wage distributions. In contrast, local...

  16. Minimum Moduli in Von Neumann Algebras | Gopalraj | Quaestiones ...

    African Journals Online (AJOL)

    In this paper we answer a question raised in [12] in the affirmative, namely that the essential minimum modulus of an element in a von. Neumann algebra, relative to any norm closed two-sided ideal, is equal to the minimum modulus of the element perturbed by an element from the ideal. As a corollary of this result, we ...

  17. 12 CFR 932.8 - Minimum liquidity requirements.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Minimum liquidity requirements. 932.8 Section... CAPITAL STANDARDS FEDERAL HOME LOAN BANK CAPITAL REQUIREMENTS § 932.8 Minimum liquidity requirements. In addition to meeting the deposit liquidity requirements contained in § 965.3 of this chapter, each Bank...

  18. Is a Minimum Wage an Appropriate Instrument for Redistribution?

    NARCIS (Netherlands)

    A.A.F. Gerritsen (Aart); B. Jacobs (Bas)

    2016-01-01

    textabstractWe analyze the redistributional (dis)advantages of a minimum wage over income taxation in competitive labor markets, without imposing assumptions on the (in)efficiency of labor rationing. Compared to a distributionally equivalent tax change, a minimum-wage increase raises involuntary

  19. The Minimum Wage and the Employment of Teenagers. Recent Research.

    Science.gov (United States)

    Fallick, Bruce; Currie, Janet

    A study used individual-level data from the National Longitudinal Study of Youth to examine the effects of changes in the federal minimum wage on teenage employment. Individuals in the sample were classified as either likely or unlikely to be affected by these increases in the federal minimum wage on the basis of their wage rates and industry of…

  20. The Effect of Minimum Wage Rates on High School Completion

    Science.gov (United States)

    Warren, John Robert; Hamrock, Caitlin

    2010-01-01

    Does increasing the minimum wage reduce the high school completion rate? Previous research has suffered from (1. narrow time horizons, (2. potentially inadequate measures of states' high school completion rates, and (3. potentially inadequate measures of minimum wage rates. Overcoming each of these limitations, we analyze the impact of changes in…

  1. Do minimum wages reduce poverty? Evidence from Central America ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    In all three countries, these multiple minimum wages are negotiated among representatives of the central government, labour unions and the chambers of commerce. Minimum wage legislation applies to all private-sector employees, but in all three countries a large part of the work force is self-employed or works as unpaid ...

  2. Entanglements in Conjugated Polymers

    Science.gov (United States)

    Xie, Renxuan; Lee, Youngmin; Aplan, Melissa; Caggiano, Nick; Gomez, Enrique; Colby, Ralph

    Conjugated polymers, such as poly(3-hexylthiophene-2,5-diyl) (P3HT) and poly-((9,9-dioctylfluorene)-2,7-diyl-alt-[4,7-bis(thiophen-5-yl)-2,1,3-benzothiadiazole]-2',2''-diyl) (PFTBT), are widely used as hole and electron transport materials in a variety of electronic devices. However, fundamental knowledge regarding chain entanglements and nematic-to-isotropic transition is still lacking and are crucial to maximize charge transport properties. A systematic melt rheology study on P3HT with various molecular weights and regio regularities was performed. We find that the entanglement molecular weight Me is 5.0 kg/mol for regiorandom P3HT, but the apparent Me for regioregular P3HT is significantly higher. The difference is postulated to arise from the presence of a nematic phase only in regioregular P3HT. Analogously, PFTBT shows a clear rheological signature of the nematic-to-isotropic transition as a reversible sharp transition at 278 C. Shearing of this nematic phase leads to anisotropic crystalline order in PFTBT. We postulate that aligning the microstructure will impact charge transport and thereby advance the field of conducting polymers. National Science Foundation.

  3. Polymer article of manufacture

    Energy Technology Data Exchange (ETDEWEB)

    Newlove, J.C.; McDougall, L.A.

    1987-12-15

    It is an object of this invention to provide an article and its use to enhance the production of hydrocarbons from geologial reservoirs, more particularly from fractured formations. It has been an additional object to devise a composition for providing controlled release of a reagent downhole, in a pipeline, in other oil-containing environments or fluids. It has been discovered that it is possible to provide for the introduction of an additive reagent into a liquid hydrocarbon by providing solid polymeric bodies each comprising a polymeric matrix containing a substantially water insoluble reagent such as a wax crystal modifier, demulsifier, scale inhibitor, corrosion inhibitor, biocide, ashless dispersant, antioxidant and mixtures thereof. These bodies are, in use, positioned at a location where it is desired to release the reagent into the substantially hydrocarbon fluid and, upon contact with fluid in this location, active reagent is released into the fluid. Thus in accordance with this invention there is provided a solid polymeric body comprising a polymer matrix containing a substantially water-insoluble reagent leachable into a substantially hydrocarbon liquid environment. The object of this invention has been realized in specific form by beads comprising a copolymeric matrix of methylmethacrylate and methacrylic acid containing the behenyl half ester of a C/sub 24/-C/sub 28/ alkenyl succinic anhydride polymer and having a diameter ranging from 0.2 to 1 mm. Such beads, when introduced downhole in a hydraulic fracturing operation, were found to inhibit paraffin wax deposition.

  4. Polymer dye lasers

    DEFF Research Database (Denmark)

    Balslev, Søren

    2006-01-01

    , elektronstrålelithografi og Röntgenstrålelithografi. Andre polymerer er også blevet formgivet via ”nanoimprint” lithografi for at skabe laserresonatorer. En række lasere, både baseret på et flydende forstærkningsmedium og et faststof forstærkningsrmedium er blevet udviklet. Laserne giver både lys i flere ”modes” og i een......Formålet med dette Ph.D. arbejde har været at udvikle miniaturiserede polymer farvestoflasere, egnet til at blive integreret i mikrochips som også indeholder andre polymerstrukturer – som for eksempel kan findes i ”Laboratorie-på-en-chip” kredsløb. Lasernes funktion skal være at levere lys til...... meget følsomme sensorformål, og at undgå at skulle opliniere eksterne lyskilder til sensorer på polymerchips. En enkelt type gennemsigtig ”resist” (SU-8) er blevet brugt til at udvikle en række laserresonatorer i polymer. ”Resisten” er blevet formgivet via en række lithografiske teknikker: UV lithografi...

  5. Homogeneous crystal nucleation in polymers.

    Science.gov (United States)

    Schick, C; Androsch, R; Schmelzer, J W P

    2017-11-15

    The pathway of crystal nucleation significantly influences the structure and properties of semi-crystalline polymers. Crystal nucleation is normally heterogeneous at low supercooling, and homogeneous at high supercooling, of the polymer melt. Homogeneous nucleation in bulk polymers has been, so far, hardly accessible experimentally, and was even doubted to occur at all. This topical review summarizes experimental findings on homogeneous crystal nucleation in polymers. Recently developed fast scanning calorimetry, with cooling and heating rates up to 10 6 K s -1 , allows for detailed investigations of nucleation near and even below the glass transition temperature, including analysis of nuclei stability. As for other materials, the maximum homogeneous nucleation rate for polymers is located close to the glass transition temperature. In the experiments discussed here, it is shown that polymer nucleation is homogeneous at such temperatures. Homogeneous nucleation in polymers is discussed in the framework of the classical nucleation theory. The majority of our observations are consistent with the theory. The discrepancies may guide further research, particularly experiments to progress theoretical development. Progress in the understanding of homogeneous nucleation is much needed, since most of the modelling approaches dealing with polymer crystallization exclusively consider homogeneous nucleation. This is also the basis for advancing theoretical approaches to the much more complex phenomena governing heterogeneous nucleation.

  6. Developments in polymer degradation - 7

    International Nuclear Information System (INIS)

    Grassie, N.

    1987-01-01

    A selection of topics which are representative of the continually expanding area of polymer degradation is presented. The aspects emphasised include the products of degradation of specific polymers, degradation by high energy radiation and mechanical forces, fire retardant studies and the special role of small radicals in degradation processes. (author)

  7. Wood and concrete polymer composites

    International Nuclear Information System (INIS)

    Singer, K.

    1974-01-01

    There are several ways to prepare and use wood and concrete polymer composites. The most important improvements in the case of concrete polymer composites are obtained for compressive and tensile strengths. The progress in this field in United States and other countries is discussed in this rview. (M.S.)

  8. All-Polymer Electrochemical Sensors

    DEFF Research Database (Denmark)

    Kafka, Jan Robert

    This thesis presents fabrication strategies to produce different types of all-polymer electrochemical sensors based on electrodes made of the highly conductive polymer poly(3,4-ethylenedioxythiophene) (PEDOT). Three different systems are presented, fabricated either by using microdrilling or by hot...

  9. Degradable polymers for tissue engineering

    NARCIS (Netherlands)

    van Dijkhuizen-Radersma, Riemke; Moroni, Lorenzo; van Apeldoorn, Aart A.; Zhang, Zheng; Grijpma, Dirk W.; van Blitterswijk, Clemens A.

    2008-01-01

    This chapter elaborates the degradable polymers for tissue engineering and their required scaffold material in tissue engineering. It recognizes the examples of degradable polymers broadly used in tissue engineering. Tissue engineering is the persuasion of the body to heal itself through the

  10. Graphene-based polymer nanocomposites

    NARCIS (Netherlands)

    Tkalya, E.

    2012-01-01

    The main reason for the rapid development of polymer composite materials is that the traditional "pure" polymers have largely played out its performance capabilities whereas technology requires materials with new properties and advances. There are a number of advantages polymeric composites have

  11. Contact mechanics in glassy polymers

    NARCIS (Netherlands)

    Breemen, van L.C.A.

    2009-01-01

    Polymers, primarily semi-crystalline, are widely used in applications where low friction is required; examples are cups in artificial hip joints, bearings and gears. Until now there is no clear indication why some polymers display low friction and others don’t. In this thesis a systematic

  12. Radiation synthesis of polymer polyol

    International Nuclear Information System (INIS)

    Guo Jianmei; Zeng Xinmiao; Zhou Chengfei; Cao Wei; Zhai Tong; Wu Dezhen

    2010-01-01

    The polymer polyol was synthesized by γ irradiation. The properties of polymer polyol synthesized with different radiation dose were studied. The experiment result showed the radiation dose hadn't significant influence on the hydroxyl value of polymer polyol. The sample with different solid content had different hydroxyl value. When the radiation dose is between 1 to 12 kGy, the viscosity and hydroxyl value of polymer polyol were increased with the increment of radiation dose. When radiation dose is between 1 to 12 kGy, with the increment of radiation dose, viscosity of polymer polyol was rapidly increased, and the content solid of sample has few change. When radiation dose is higher than 20 kGy, the viscosity and hydroxyl value of polymer polyol have gradually increase with the increment of radiation dose. The size of polymer particles is 0.1-0.6 μm. The value of 150 mesh filter was 100%. The polymer polyol may be used as PU foam and elastomer. (authors)

  13. HIGH TEMPERATURE POLYMER FUEL CELLS

    DEFF Research Database (Denmark)

    Jensen, Jens Oluf; Qingfeng, Li; He, Ronghuan

    2003-01-01

    This paper will report recent results from our group on polymer fuel cells (PEMFC) based on the temperature resistant polymer polybenzimidazole (PBI), which allow working temperatures up to 200°C. The membrane has a water drag number near zero and need no water management at all. The high working...

  14. Fifty years of polymer science

    NARCIS (Netherlands)

    Du Prez, Filip; Hoogenboom, Richard; Klumperman, Bert; Meier, Michael; Monteiro, Michael; Müller, Alejandro; Vancso, Gyula J.

    2015-01-01

    The European Polymer Journal (EPJ) has been serving the scientific community for 50 years, which makes it one of the older macromolecular journals with a broad focus. Since its launch 50 years ago, EPJ has provided a distinguished forum for publications in polymer research, including chemistry,

  15. Literacy for QTLS achieving the minimum core

    CERN Document Server

    Hickey, Julia

    2013-01-01

    Literacy for QTLS is written specifically with the needs of all those training to teach or currently working in the lifelong learning sector in mind. This highly practical and easy-to-use text will help you identify your areas of strength and weakness, develop your knowledge and skills in order to pass the national literacy test and adopt strategies that you can use to support the language and literacy skills of your own learners.Packed with test-your-knowledge questions, examples and recommendations for best practice, this book, closely linked to the QTLS standards, is essential reading for a

  16. Minimum Variance Portfolios in the Brazilian Equity Market

    Directory of Open Access Journals (Sweden)

    Alexandre Rubesam

    2013-03-01

    Full Text Available We investigate minimum variance portfolios in the Brazilian equity market using different methods to estimate the covariance matrix, from the simple model of using the sample covariance to multivariate GARCH models. We compare the performance of the minimum variance portfolios to those of the following benchmarks: (i the IBOVESPA equity index, (ii an equally-weighted portfolio, (iii the maximum Sharpe ratio portfolio and (iv the maximum growth portfolio. Our results show that the minimum variance portfolio has higher returns with lower risk compared to the benchmarks. We also consider long-short 130/30 minimum variance portfolios and obtain similar results. The minimum variance portfolio invests in relatively few stocks with low βs measured with respect to the IBOVESPA index, being easily replicable by individual and institutional investors alike.

  17. Reducing tobacco use and access through strengthened minimum price laws.

    Science.gov (United States)

    McLaughlin, Ian; Pearson, Anne; Laird-Metke, Elisa; Ribisl, Kurt

    2014-10-01

    Higher prices reduce consumption and initiation of tobacco products. A minimum price law that establishes a high statutory minimum price and prohibits the industry's discounting tactics for tobacco products is a promising pricing strategy as an alternative to excise tax increases. Although some states have adopted minimum price laws on the basis of statutorily defined price "markups" over the invoice price, existing state laws have been largely ineffective at increasing the retail price. We analyzed 3 new variations of minimum price laws that hold great potential for raising tobacco prices and reducing consumption: (1) a flat rate minimum price law similar to a recent enactment in New York City, (2) an enhanced markup law, and (3) a law that incorporates both elements.

  18. The impact of minimum wage adjustments on Vietnamese wage inequality

    DEFF Research Database (Denmark)

    Hansen, Henrik; Rand, John; Torm, Nina

    Using Vietnamese Labour Force Survey data we analyse the impact of minimum wage changes on wage inequality. Minimum wages serve to reduce local wage inequality in the formal sectors by decreasing the gap between the median wages and the lower tail of the local wage distributions. In contrast, local...... wage inequality is increased in the informal sectors. Overall, the minimum wages decrease national wage inequality. Our estimates indicate a decrease in the wage distribution Gini coefficient of about 2 percentage points and an increase in the 10/50 wage ratio of 5-7 percentage points caused...... by the adjustment of the minimum wages from 2011to 2012 that levelled the minimum wage across economic sectors....

  19. Characterization of ethyl cellulose polymer.

    Science.gov (United States)

    Mahnaj, Tazin; Ahmed, Salah U; Plakogiannis, Fotios M

    2013-01-01

    Ethyl cellulose (EC) polymer was characterized for its property before considering the interactions with the plasicizer. Ethocel Std.10 FP Premium from Dow chemical company USA was tested for its solubility, morphology and thermal properties. Seven percentage of EC solution in ethanol was found to be the right viscosity used to prepare the film. The EC polymer and EC film without any plasticizers showed almost identical thermal behavior, but in X-ray diffraction showed different arrangements of crystallites and amorphous region. Dynamic mechanical analysis of film showed that without a plasticizer, EC film was not flexible and had very low elongation with high applied force. The aim of the work was to avoid using the commercially available EC dispersions Surelease® and Aquacoat®; both already have additives on it. Instead, Ethocel EC polymer (powder) was characterized in our laboratory in order to find out the properties of polymer before considering the interactions of the polymer with various plasticizers.

  20. Accelerated Characterization of Polymer Properties

    Energy Technology Data Exchange (ETDEWEB)

    R. Wroczynski; l. Brewer; D. Buckley; M. Burrell; R. Potyrailo

    2003-07-30

    This report describes the efforts to develop a suite of microanalysis techniques that can rapidly measure a variety of polymer properties of industrial importance, including thermal, photo-oxidative, and color stability; as well as ductility, viscosity, and mechanical and antistatic properties. Additional goals of the project were to direct the development of these techniques toward simultaneous measurements of multiple polymer samples of small size in real time using non-destructive and/or parallel or rapid sequential measurements, to develop microcompounding techniques for preparing polymers with additives, and to demonstrate that samples prepared in the microcompounder could be analyzed directly or used in rapid off-line measurements. These enabling technologies are the crucial precursors to the development of high-throughput screening (HTS) methodologies for the polymer additives industry whereby the rate of development of new additives and polymer formulations can be greatly accelerated.

  1. Controlled Release from Recombinant Polymers

    Science.gov (United States)

    Price, Robert; Poursaid, Azadeh; Ghandehari, Hamidreza

    2014-01-01

    Recombinant polymers provide a high degree of molecular definition for correlating structure with function in controlled release. The wide array of amino acids available as building blocks for these materials lend many advantages including biorecognition, biodegradability, potential biocompatibility, and control over mechanical properties among other attributes. Genetic engineering and DNA manipulation techniques enable the optimization of structure for precise control over spatial and temporal release. Unlike the majority of chemical synthetic strategies used, recombinant DNA technology has allowed for the production of monodisperse polymers with specifically defined sequences. Several classes of recombinant polymers have been used for controlled drug delivery. These include, but are not limited to, elastin-like, silk-like, and silk-elastinlike proteins, as well as emerging cationic polymers for gene delivery. In this article, progress and prospects of recombinant polymers used in controlled release will be reviewed. PMID:24956486

  2. Direct Photopatterning of Electrochromic Polymers

    DEFF Research Database (Denmark)

    Jensen, Jacob; Dyer, Aubrey L.; Shen, D. Eric

    2013-01-01

    Propylenedioxythiophene (ProDOT) polymers are synthesized using an oxidative polymerization route that results in methacrylate substituted poly(ProDOTs) having a Mn of 10–20 kDa wherein the methacrylate functionality constitutes from 6 to 60% of the total monomer units. Solutions of these polymers...... show excellent film forming abilities, with thin films prepared using both spray‐casting and spin‐coating. These polymers are demonstrated to crosslink upon UV irradiation at 350 nm, in the presence of an appropriate photoinitiator, to render the films insoluble to common organic solvents....... Electrochemical, spectroelectrochemical, and colorimetric analyses of the crosslinked polymer films are performed to establish that they retain the same electrochromic qualities as the parent polymers with no detriment to the observed properties. To demonstrate applicability for multi‐film processing...

  3. Polymer research by neutron scattering

    International Nuclear Information System (INIS)

    Richter, D.

    1993-01-01

    Polymer physics aims on an understanding of the macroscopic behavior of polymer systems on the basis of their molecular structure and dynamics. For this purpose neutrons serve as a unique probe, allowing a simultaneous investigation of polymer structure and dynamics on a molecular scale. Furthermore, hydrogen deuterium exchange facilitates molecular labeling and offers the possibility to observe selected chains or chain parts in dense systems. Neutron small angle scattering reveals information on the conformation and possible aggregation of polymer chains. Data on linear and star like molecules are shown as examples. High resolution neutron spin-echospectroscopy observes the molecular dynamics of long chain molecules. Results on the large scale motion of chins in polymer melts are presented. finally, experiments on chain relaxation close to the glass transition are displayed. Three distinctly different relaxation processes are revealed. (author)

  4. Polymer materials for fusion reactors

    International Nuclear Information System (INIS)

    Yamaoka, H.

    1993-01-01

    The radiation-resistant polymer materials have recently drawn much attention from the viewpoint of components for fusion reactors. These are mainly applied to electrical insulators, thermal insulators and structural supports of superconducting magnets in fusion reactors. The polymer materials used for these purposes are required to withstand the synergetic effects of high mechanical loads, cryogenic temperatures and intense nuclear radiation. The objective of this review is to summarize the anticipated performance of candidate materials including polymer composites for fusion magnets. The cryogenic properties and the radiation effects of polymer materials are separately reviewed, because there is only limited investigation on the above-mentioned synergetic effects. Additional information on advanced polymer materials for fusion reactors is also introduced with emphasis on recent developments. (orig.)

  5. Ion beam modification of polymers

    International Nuclear Information System (INIS)

    Sofield, C.J.; Sugden, S.; Ing, J.; Bridwell, L.B.; Wang, Y.Q.

    1993-01-01

    The implantation of polymers has received considerable attention in recent years, primarily to examine doping of conducting polymers and to increase the surface conductivity (by many orders of magnitude) of highly insulating polymers. The interest in these studies was partly motivated by possible applications to microelectronic device fabrication. More recently it has been observed that ion implantation can under some conditions lead to the formation of a hard (e.g. as hard as steel, ca. 3 MPa) and conducting surface layer. This paper will review the ion beam modification of polymers resulting from ion implantation with reference to fundamental ion-solid interactions. This leads us to examine whether or not implantation of polymers is a contradiction in terms. (Author)

  6. Minimum period and the gap in periods of Cataclysmic binaries

    International Nuclear Information System (INIS)

    Paczynski, B.; Sienkiewicz, R.

    1983-01-01

    The 81 minute cutoff to the orbital periods of hydrogen-rich cataclysmic binaries is consistent with evolution of those systems being dominated by angular momentum losses due to gravitational radiation. Unfortunately, many uncertainties, mainly poorly known atmospheric opacities below 2000 K, make is physically impossible to verify the quadrupole formula for gravitational radiation by using the observed cutoff at 81 minutes. The upper boundary of the gap in orbital periods observed at about 3 hours is almost certainly due to enhanced angular momentum losses from cataclysmic binaries which have longer periods. The physical mechanism of those losses is not identified, but a possible importance of stellar winds is pointed out. The lower boundary of the gap may be explained with the oldest cataclysmic binaries, whose periods evolved past the minimum at 81 minutes and reached the value of 2 hours within about 12 x 10 9 years after the binary had formed. Those binaries should have secondary components of only 0.02 solar masses, and their periods could be used to estimate ages of the oldest cataclysmic stars, and presumably the age of Galaxy. An alternative explanation for the gap requires that binaries should be detached while crossing the gap. A possible mechanism for this phenomenon is discussed. It requires the secondary components to be about 0.2 solar masses in the binaries just below the gap

  7. A Proposal for an Austrian Nursing Minimum Data Set (NMDS)

    Science.gov (United States)

    Hackl, W.O.; Ammenwerth, E.

    2014-01-01

    Summary Objective Nursing Minimum Data Sets can be used to compare nursing care across clinical populations, settings, geographical areas, and time. NMDS can support nursing research, nursing management, and nursing politics. However, in contrast to other countries, Austria does not have a unified NMDS. The objective of this study is to identify possible data elements for an Austrian NMDS. Methods A two-round Delphi survey was conducted, based on a review of available NMDS, 22 expert interviews, and a focus group discussion. Results After reaching consensus, the experts proposed the following 56 data elements for an NMDS: six data elements concerning patient demographics, four data elements concerning data of the healthcare institution, four data elements concerning patient’s medical condition, 20 data elements concerning patient problems (nursing assessment, nursing diagnoses, risk assessment), eight data elements concerning nursing outcomes, 14 data elements concerning nursing interventions, and no additional data elements concerning nursing intensity. Conclusion The proposed NMDS focuses on the long-term and acute care setting. It must now be implemented and tested in the nursing practice. PMID:25024767

  8. Characterization of Polymer Surfaces by the Use of Different Wetting Theories Regarding Acid-Base Properties

    Directory of Open Access Journals (Sweden)

    Eduard Kraus

    2017-01-01

    Full Text Available The existing wetting methods for the determination of acid-base properties on solid surfaces are discussed. Striving for a better understanding of the adhesive polymer interactions in adhesively joined polymers, the methods of Berger and van Oss-Chaudhury-Good were found as the most suitable methods for the investigation of wetting on solid polymer surfaces. Methods of nonlinear systems by Della Volpe and Siboni were adapted and evaluated on plastic surfaces. In the context of these investigations various data of the surface free energy as well as its components have been identified for a number of polymer surfaces by application of spatial equation solutions.

  9. Teaching the Minimum Wage in Econ 101 in Light of the New Economics of the Minimum Wage.

    Science.gov (United States)

    Krueger, Alan B.

    2001-01-01

    Argues that the recent controversy over the effect of the minimum wage on employment offers an opportunity for teaching introductory economics. Examines eight textbooks to determine topic coverage but finds little consensus. Describes how minimum wage effects should be taught. (RLH)

  10. Cementation of nuclear graphite using geo-polymers

    International Nuclear Information System (INIS)

    Girke, N.A.; Steinmetz, H.J.; Bukaemsky, A.; Bosbach, D.; Hermann, E.; Griebel, I.

    2012-01-01

    Geo-polymers are solid aluminosilicate materials usually formed by alkali hydroxide or alkali silicate activation of solid precursors such as coal fly ash, calcined clay and/or metallurgical slag. Today the primary application of geo-polymer technology is in the development of alternatives to Portland-based cements. Variations in the ratio of aluminium to silicon, and alkali to silicon or addition of structure support, produce geo-polymers with different physical and mechanical properties. These materials have an amorphous three-dimensional structure that gives geo-polymers certain properties, such as fire and acid resistance, low leach rate, which make them an ideal substitute for ordinary Portland cement (OPC) in a wide range of applications especially in conditioning and storage of radioactive waste. Therefore investigations have been initiated about how and to which amount graphite as a hydrophobic material can be mixed with cement or concrete to form stable waste products and which concretes fulfill the specifications at best. As result geo-polymers have been identified as a promising matrix for graphite containing nuclear wastes. With geo-polymers both favorable properties in the cementation process and a high long time structural stability of the products can be achieved. (authors)

  11. Natural Phenol Polymers: Recent Advances in Food and Health Applications.

    Science.gov (United States)

    Panzella, Lucia; Napolitano, Alessandra

    2017-04-14

    Natural phenol polymers are widely represented in nature and include a variety of classes including tannins and lignins as the most prominent. Largely consumed foods are rich sources of phenol polymers, notably black foods traditionally used in East Asia, but other non-edible, easily accessible sources, e.g., seaweeds and wood, have been considered with increasing interest together with waste materials from agro-based industries, primarily grape pomace and other byproducts of fruit and coffee processing. Not in all cases were the main structural components of these materials identified because of their highly heterogeneous nature. The great beneficial effects of natural phenol-based polymers on human health and their potential in improving the quality of food were largely explored, and this review critically addresses the most interesting and innovative reports in the field of nutrition and biomedicine that have appeared in the last five years. Several in vivo human and animal trials supported the proposed use of these materials as food supplements and for amelioration of the health and production of livestock. Biocompatible and stable functional polymers prepared by peroxidase-catalyzed polymerization of natural phenols, as well as natural phenol polymers were exploited as conventional and green plastic additives in smart packaging and food-spoilage prevention applications. The potential of natural phenol polymers in regenerative biomedicine as additives of biomaterials to promote growth and differentiation of osteoblasts is also discussed.

  12. Formulation of 3D Printed Tablet for Rapid Drug Release by Fused Deposition Modeling: Screening Polymers for Drug Release, Drug-Polymer Miscibility and Printability.

    Science.gov (United States)

    Solanki, Nayan G; Tahsin, Md; Shah, Ankita V; Serajuddin, Abu T M

    2018-01-01

    The primary aim of this study was to identify pharmaceutically acceptable amorphous polymers for producing 3D printed tablets of a model drug, haloperidol, for rapid release by fused deposition modeling. Filaments for 3D printing were prepared by hot melt extrusion at 150°C with 10% and 20% w/w of haloperidol using Kollidon ® VA64, Kollicoat ® IR, Affinsiol ™ 15 cP, and HPMCAS either individually or as binary blends (Kollidon ® VA64 + Affinisol ™ 15 cP, 1:1; Kollidon ® VA64 + HPMCAS, 1:1). Dissolution of crushed extrudates was studied at pH 2 and 6.8, and formulations demonstrating rapid dissolution rates were then analyzed for drug-polymer, polymer-polymer and drug-polymer-polymer miscibility by film casting. Polymer-polymer (1:1) and drug-polymer-polymer (1:5:5 and 2:5:5) mixtures were found to be miscible. Tablets with 100% and 60% infill were printed using MakerBot printer at 210°C, and dissolution tests of tablets were conducted at pH 2 and 6.8. Extruded filaments of Kollidon ® VA64-Affinisol ™ 15 cP mixtures were flexible and had optimum mechanical strength for 3D printing. Tablets containing 10% drug with 60% and 100% infill showed complete drug release at pH 2 in 45 and 120 min, respectively. Relatively high dissolution rates were also observed at pH 6.8. The 1:1-mixture of Kollidon ® VA64 and Affinisol ™ 15 cP was thus identified as a suitable polymer system for 3D printing and rapid drug release. Copyright © 2018 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  13. Comprehensive study on estimation of gamma-ray exposure buildup factors for smart polymers as a potent application in nuclear industries

    Science.gov (United States)

    Sayyed, M. I.; AlZaatreh, M. Y.; Matori, K. A.; Sidek, H. A. A.; Zaid, M. H. M.

    2018-06-01

    In the present study, the exposure buildup factors (EBF) have been investigated using geometric progression (G-P) fitting method for different types of smart polymers (DMSO, PDMS, PES, PMA, PVDC, and PVDF) in the energy range of 0.015-15 MeV. From the calculations, the values of the EBF were depended on the incident photon energy, penetration depth as well as chemical composition of the polymers. In the intermediate energy region, the EBF values were reached at maximum point while in low and high energy regions, the EBF values were decreased at minimum point. The obtained results of the selected polymers have been compared in terms of EBF with Al2O3 and other common polymers such as PAN, Teflon and SR. The shielding effectiveness of the selected polymers is found to be comparable to the common polymers. The results of this work should be useful in radiation shielding applications such as in industry, medical and nuclear engineering.

  14. Polymers – A New Open Access Scientific Journal on Polymer Science

    Directory of Open Access Journals (Sweden)

    Shu-Kun Lin

    2009-12-01

    Full Text Available Polymers is a new interdisciplinary, Open Access scientific journal on polymer science, published by Molecular Diversity Preservation International (MDPI. This journal welcomes manuscript submissions on polymer chemistry, macromolecular chemistry, polymer physics, polymer characterization and all related topics. Both synthetic polymers and natural polymers, including biopolymers, are considered. Manuscripts will be thoroughly peer-reviewed in a timely fashion, and papers will be published, if accepted, within 6 to 8 weeks after submission. [...

  15. Assessing the impacts of Saskatchewan's minimum alcohol pricing regulations on alcohol-related crime.

    Science.gov (United States)

    Stockwell, Tim; Zhao, Jinhui; Sherk, Adam; Callaghan, Russell C; Macdonald, Scott; Gatley, Jodi

    2017-07-01

    Saskatchewan's introduction in April 2010 of minimum prices graded by alcohol strength led to an average minimum price increase of 9.1% per Canadian standard drink (=13.45 g ethanol). This increase was shown to be associated with reduced consumption and switching to lower alcohol content beverages. Police also informally reported marked reductions in night-time alcohol-related crime. This study aims to assess the impacts of changes to Saskatchewan's minimum alcohol-pricing regulations between 2008 and 2012 on selected crime events often related to alcohol use. Data were obtained from Canada's Uniform Crime Reporting Survey. Auto-regressive integrated moving average time series models were used to test immediate and lagged associations between minimum price increases and rates of night-time and police identified alcohol-related crimes. Controls were included for simultaneous crime rates in the neighbouring province of Alberta, economic variables, linear trend, seasonality and autoregressive and/or moving-average effects. The introduction of increased minimum-alcohol prices was associated with an abrupt decrease in night-time alcohol-related traffic offences for men (-8.0%, P prices may contribute to reductions in alcohol-related traffic-related and violent crimes perpetrated by men. Observed lagged effects for violent incidents may be due to a delay in bars passing on increased prices to their customers, perhaps because of inventory stockpiling. [Stockwell T, Zhao J, Sherk A, Callaghan RC, Macdonald S, Gatley J. Assessing the impacts of Saskatchewan's minimum alcohol pricing regulations on alcohol-related crime. Drug Alcohol Rev 2017;36:492-501]. © 2016 Australasian Professional Society on Alcohol and other Drugs.

  16. Industrial Irradiation of Polymers: Systems and Concepts

    International Nuclear Information System (INIS)

    Mittendorfer, J.

    2006-01-01

    This paper provides a systematic survey of systems and concepts used in the industrial irradiation of polymers. It consists basically of three parts: in the first part, different types of applications like wires and cables, pipes and engineering plastics are discussed and the associated irradiation systems analyzed and highlighted according their basics modules. These are identified as the radiation source, the product handling system, process control and facility/shielding layout. In the second part, the irradiation process design is reviewed in detail. The discussion starts with the requirement analysis, e.g. the desired polymer parameters and effects, continues with a process development roadmap and concludes with process verification and validation. Special attention is drawn to process control, which plays an important role in industrial irradiation technology. The use of mathematical modeling to facilitate and support process and system design is discussed as well and several examples are given which demonstrate their capabilities. In the third part, the design of a electron beam facility for the irradiation of small plastic parts for the automotive industry is worked out in detail. Besides system and product handling considerations, throughput and economical estimates are provided. The paper concludes with a summary of the design and concept bullets which proved to be important in history and can facilitate new developments which will enhance the potential of industrial polymer irradiation

  17. Mechanical transduction via a single soft polymer

    Science.gov (United States)

    Hou, Ruizheng; Wang, Nan; Bao, Weizhu; Wang, Zhisong

    2018-04-01

    Molecular machines from biology and nanotechnology often depend on soft structures to perform mechanical functions, but the underlying mechanisms and advantages or disadvantages over rigid structures are not fully understood. We report here a rigorous study of mechanical transduction along a single soft polymer based on exact solutions to the realistic three-dimensional wormlike-chain model and augmented with analytical relations derived from simpler polymer models. The results reveal surprisingly that a soft polymer with vanishingly small persistence length below a single chemical bond still transduces biased displacement and mechanical work up to practically significant amounts. This "soft" approach possesses unique advantages over the conventional wisdom of rigidity-based transduction, and potentially leads to a unified mechanism for effective allosterylike transduction and relay of mechanical actions, information, control, and molecules from one position to another in molecular devices and motors. This study also identifies an entropy limit unique to the soft transduction, and thereby suggests a possibility of detecting higher efficiency for kinesin motor and mutants in future experiments.

  18. Three-dimensional patterning in polymer optical waveguides using focused ion beam milling

    Science.gov (United States)

    Kruse, Kevin; Burrell, Derek; Middlebrook, Christopher

    2016-07-01

    Waveguide (WG) photonic-bridge taper modules are designed for symmetric planar coupling between silicon WGs and single-mode fibers (SMFs) to minimize photonic chip and packaging footprint requirements with improving broadband functionality. Micromachined fabrication and evaluation of polymer WG tapers utilizing high-resolution focused ion beam (FIB) milling is performed and presented. Polymer etch rates utilizing the FIB and optimal methods for milling polymer tapers are identified for three-dimensional patterning. Polymer WG tapers with low sidewall roughness are manufactured utilizing FIB milling and optically tested for fabrication loss. FIB platforms utilize a focused beam of ions (Ga+) to etch submicron patterns into substrates. Fabricating low-loss polymer WG taper prototypes with the FIB before moving on to mass-production techniques provides theoretical understanding of the polymer taper and its feasibility for connectorization devices between silicon WGs and SMFs.

  19. SULFUR POLYMER ENCAPSULATION

    International Nuclear Information System (INIS)

    KALB, P.

    2001-01-01

    Sulfur polymer cement (SPC) is a thermoplastic polymer consisting of 95 wt% elemental sulfur and 5 wt% organic modifiers to enhance long-term durability. SPC was originally developed by the U.S. Bureau of Mines as an alternative to hydraulic cement for construction applications. Previous attempts to use elemental sulfur as a construction material in the chemical industry failed due to premature degradation. These failures were caused by the internal stresses that result from changes in crystalline structure upon cooling of the material. By reacting elemental sulfur with organic polymers, the Bureau of Mines developed a product that successfully suppresses the solid phase transition and significantly improves the stability of the product. SPC, originally named modified sulfur cement, is produced from readily available, inexpensive waste sulfur derived from desulfurization of both flue gases and petroleum. The commercial production of SPC is licensed in the United States by Martin Resources (Odessa, Texas) and is marketed under the trade name Chement 2000. It is sold in granular form and is relatively inexpensive ((approx)$0.10 to 0.12/lb). Application of SPC for the treatment of radioactive, hazardous, and mixed wastes was initially developed and patented by Brookhaven National Laboratory (BNL) in the mid-1980s (Kalb and Colombo, 1985; Colombo et al., 1997). The process was subsequently investigated by the Commission of the European Communities (Van Dalen and Rijpkema, 1989), Idaho National Engineering Laboratory (Darnell, 1991), and Oak Ridge National Laboratory (Mattus and Mattus, 1994). SPC has been used primarily in microencapsulation applications but can also be used for macroencapsulation of waste. SPC microencapsulation has been demonstrated to be an effective treatment for a wide variety of wastes, including incinerator hearth and fly ash; aqueous concentrates such as sulfates, borates, and chlorides; blowdown solutions; soils; and sludges. It is not

  20. Physical Properties of Polymers (Ultrastructure Processing of Polymers)

    Science.gov (United States)

    1982-09-30

    vinyl benzene Network-Diluent Systems". 17. J . Appl. Polym. Sci. 28, 219-224 (1983) (with R. Vukovic and W.J. MacKnight) "Compatibility of Some...Temperature of Polymer Networks by Dil uents". 23. J . Appl. Polym. Sci. 28, 1379-1389 (1983) (with R. Vukovic , V. Kuresevic, N. Segudovic, and W.J...AFOSR 80-0101 IV. DATES: 1 January 1980 - 30 September 1982 V. SENIOR RESEARCH PERSONNEL*: Dr. C. Crosby Dr. G. ten Brinke Dr. T. Ellis Dr. R. Vukovic

  1. Conjugated polymer zwitterions and solar cells comprising conjugated polymer zwitterions

    Science.gov (United States)

    Emrick, Todd; Russell, Thomas; Page, Zachariah; Liu, Yao

    2018-06-05

    A conjugated polymer zwitterion includes repeating units having structure (I), (II), or a combination thereof ##STR00001## wherein Ar is independently at each occurrence a divalent substituted or unsubstituted C3-30 arylene or heteroarylene group; L is independently at each occurrence a divalent C1-16 alkylene group, C6-30arylene or heteroarylene group, or alkylene oxide group; and R1 is independently at each occurrence a zwitterion. A polymer solar cell including the conjugated polymer zwitterion is also disclosed.

  2. Toward the minimum inner edge distance of the habitable zone

    Energy Technology Data Exchange (ETDEWEB)

    Zsom, Andras; Seager, Sara; De Wit, Julien; Stamenković, Vlada, E-mail: zsom@mit.edu [Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)

    2013-12-01

    We explore the minimum distance from a host star where an exoplanet could potentially be habitable in order not to discard close-in rocky exoplanets for follow-up observations. We find that the inner edge of the Habitable Zone for hot desert worlds can be as close as 0.38 AU around a solar-like star, if the greenhouse effect is reduced (∼1% relative humidity) and the surface albedo is increased. We consider a wide range of atmospheric and planetary parameters such as the mixing ratios of greenhouse gases (water vapor and CO{sub 2}), surface albedo, pressure, and gravity. Intermediate surface pressure (∼1-10 bars) is necessary to limit water loss and to simultaneously sustain an active water cycle. We additionally find that the water loss timescale is influenced by the atmospheric CO{sub 2} level, because it indirectly influences the stratospheric water mixing ratio. If the CO{sub 2} mixing ratio of dry planets at the inner edge is smaller than 10{sup –4}, the water loss timescale is ∼1 billion years, which is considered here too short for life to evolve. We also show that the expected transmission spectra of hot desert worlds are similar to an Earth-like planet. Therefore, an instrument designed to identify biosignature gases in an Earth-like atmosphere can also identify similarly abundant gases in the atmospheres of dry planets. Our inner edge limit is closer to the host star than previous estimates. As a consequence, the occurrence rate of potentially habitable planets is larger than previously thought.

  3. Toward the minimum inner edge distance of the habitable zone

    International Nuclear Information System (INIS)

    Zsom, Andras; Seager, Sara; De Wit, Julien; Stamenković, Vlada

    2013-01-01

    We explore the minimum distance from a host star where an exoplanet could potentially be habitable in order not to discard close-in rocky exoplanets for follow-up observations. We find that the inner edge of the Habitable Zone for hot desert worlds can be as close as 0.38 AU around a solar-like star, if the greenhouse effect is reduced (∼1% relative humidity) and the surface albedo is increased. We consider a wide range of atmospheric and planetary parameters such as the mixing ratios of greenhouse gases (water vapor and CO 2 ), surface albedo, pressure, and gravity. Intermediate surface pressure (∼1-10 bars) is necessary to limit water loss and to simultaneously sustain an active water cycle. We additionally find that the water loss timescale is influenced by the atmospheric CO 2 level, because it indirectly influences the stratospheric water mixing ratio. If the CO 2 mixing ratio of dry planets at the inner edge is smaller than 10 –4 , the water loss timescale is ∼1 billion years, which is considered here too short for life to evolve. We also show that the expected transmission spectra of hot desert worlds are similar to an Earth-like planet. Therefore, an instrument designed to identify biosignature gases in an Earth-like atmosphere can also identify similarly abundant gases in the atmospheres of dry planets. Our inner edge limit is closer to the host star than previous estimates. As a consequence, the occurrence rate of potentially habitable planets is larger than previously thought.

  4. Setting a minimum age for juvenile justice jurisdiction in California.

    Science.gov (United States)

    S Barnert, Elizabeth; S Abrams, Laura; Maxson, Cheryl; Gase, Lauren; Soung, Patricia; Carroll, Paul; Bath, Eraka

    2017-03-13

    Purpose Despite the existence of minimum age laws for juvenile justice jurisdiction in 18 US states, California has no explicit law that protects children (i.e. youth less than 12 years old) from being processed in the juvenile justice system. In the absence of a minimum age law, California lags behind other states and international practice and standards. The paper aims to discuss these issues. Design/methodology/approach In this policy brief, academics across the University of California campuses examine current evidence, theory, and policy related to the minimum age of juvenile justice jurisdiction. Findings Existing evidence suggests that children lack the cognitive maturity to comprehend or benefit from formal juvenile justice processing, and diverting children from the system altogether is likely to be more beneficial for the child and for public safety. Research limitations/implications Based on current evidence and theory, the authors argue that minimum age legislation that protects children from contact with the juvenile justice system and treats them as children in need of services and support, rather than as delinquents or criminals, is an important policy goal for California and for other national and international jurisdictions lacking a minimum age law. Originality/value California has no law specifying a minimum age for juvenile justice jurisdiction, meaning that young children of any age can be processed in the juvenile justice system. This policy brief provides a rationale for a minimum age law in California and other states and jurisdictions without one.

  5. Setting a minimum age for juvenile justice jurisdiction in California

    Science.gov (United States)

    Barnert, Elizabeth S.; Abrams, Laura S.; Maxson, Cheryl; Gase, Lauren; Soung, Patricia; Carroll, Paul; Bath, Eraka

    2018-01-01

    Purpose Despite the existence of minimum age laws for juvenile justice jurisdiction in 18 US states, California has no explicit law that protects children (i.e. youth less than 12 years old) from being processed in the juvenile justice system. In the absence of a minimum age law, California lags behind other states and international practice and standards. The paper aims to discuss these issues. Design/methodology/approach In this policy brief, academics across the University of California campuses examine current evidence, theory, and policy related to the minimum age of juvenile justice jurisdiction. Findings Existing evidence suggests that children lack the cognitive maturity to comprehend or benefit from formal juvenile justice processing, and diverting children from the system altogether is likely to be more beneficial for the child and for public safety. Research limitations/implications Based on current evidence and theory, the authors argue that minimum age legislation that protects children from contact with the juvenile justice system and treats them as children in need of services and support, rather than as delinquents or criminals, is an important policy goal for California and for other national and international jurisdictions lacking a minimum age law. Originality/value California has no law specifying a minimum age for juvenile justice jurisdiction, meaning that young children of any age can be processed in the juvenile justice system. This policy brief provides a rationale for a minimum age law in California and other states and jurisdictions without one. Paper type Conceptual paper PMID:28299968

  6. Minimum wall pressure coefficient of orifice plate energy dissipater

    Directory of Open Access Journals (Sweden)

    Wan-zheng Ai

    2015-01-01

    Full Text Available Orifice plate energy dissipaters have been successfully used in large-scale hydropower projects due to their simple structure, convenient construction procedure, and high energy dissipation ratio. The minimum wall pressure coefficient of an orifice plate can indirectly reflect its cavitation characteristics: the lower the minimum wall pressure coefficient is, the better the ability of the orifice plate to resist cavitation damage is. Thus, it is important to study the minimum wall pressure coefficient of the orifice plate. In this study, this coefficient and related parameters, such as the contraction ratio, defined as the ratio of the orifice plate diameter to the flood-discharging tunnel diameter; the relative thickness, defined as the ratio of the orifice plate thickness to the tunnel diameter; and the Reynolds number of the flow through the orifice plate, were theoretically analyzed, and their relationships were obtained through physical model experiments. It can be concluded that the minimum wall pressure coefficient is mainly dominated by the contraction ratio and relative thickness. The lower the contraction ratio and relative thickness are, the larger the minimum wall pressure coefficient is. The effects of the Reynolds number on the minimum wall pressure coefficient can be neglected when it is larger than 105. An empirical expression was presented to calculate the minimum wall pressure coefficient in this study.

  7. Polymers Erosion and Contamination Experiment Being Developed

    Science.gov (United States)

    deGroh, Kim K.; Banks, Bruce A.; Barney-Barton, Elyse A.; Sechkar, Edward; Hunt, Patricia

    1999-01-01

    The Polymers Erosion and Contamination Experiment (PEACE) is currently being developed at the NASA Lewis Research Center by the Electro-Physics Branch in conjunction with students and faculty from Hathaway Brown School in Cleveland. The experiment is a Get Away Special Canister shuttle flight experiment sponsored by the American Chemical Society. The two goals of this experiment are (1) to measure ram atomic oxygen erosion rates of approximately 40 polymers that have potential use in space applications and (2) to validate a method for identifying sources of silicone contamination that occur in the shuttle bay. Equipment to be used in this flight experiment is shown in the schematic diagram. Spacecraft materials subjected to attack by atomic oxygen in the space environment experience significant degradation over the span of a typical mission. Therefore, learning the rates of atomic oxygen erosion of a wide variety of polymers would be of great benefit to future missions. PEACE will use two independent techniques to determine the atomic oxygen erosion rates of polymers. Large (1-in.-diameter) samples will be used for obtaining mass loss. Preflight and postflight dehydrated masses will be obtained, and the mass lost during flight will be determined. Small (0.5-in.-diameter) samples will be protected with isolated particles (such as NaCl crystals) and then exposed to the space environment. After flight, the protective particles will be removed (washed off) and atomic force microscopy (AFM) will be used to measure the erosion depth from protected mesas. Erosion depth measurements are more sensitive than traditional mass measurements and are very useful for materials with low erosion yields or with very low fluence missions.

  8. Protein Polymers and Amyloids

    DEFF Research Database (Denmark)

    Risør, Michael Wulff

    2014-01-01

    Several human disorders are caused by a common general disease mechanism arising from abnormal folding and aggregation of the underlying protein. These include the prevalent dementias like Alzheimer’s and Parkinson’s, where accumulation of protein fibrillar structures, known as amyloid fibrils......, is a general hallmark. They also include the α1-antitrypsin deficiency, where disease-causing mutations in the serine protease inhibitor, α1-antitrypsin (α1AT), leads to accumulation of the aberrant protein in the liver of these patients. The native metastable structure of α1AT constitutes a molecular trap...... that inhibits its target protease through a large conformational change but mutations compromise this function and cause premature structural collapse into hyperstable polymers. Understanding the conformational disorders at a molecular level is not only important for our general knowledge on protein folding...

  9. Sodium conducting polymer electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Skaarup, S.; West, K. (eds.)

    1989-04-01

    This section deals with the aspects of ionic conduction in general as well as specific experimental results obtained for sodium systems. The conductivity as a function of temperature and oxygen/metal ratio are given for the systems NaI, NaCF/sub 3/SO/sub 3/ and NaClO/sub 4/ plus polyethylene oxide. Attempts have been made to produce mixed phase solid electrolytes analogous to the lithium systems that have worked well. These consist of mixtures of polymer and a solid electrolyte. The addition of both nasicon and sodium beta alumina unexpectedly decreases the ionic conductivity in contrast to the lithium systems. Addition of the nonconducting silica AEROSIL in order to increase the internal surface area has the effect of retarding the phase transition at 60 deg. C, but does not enhance the conductivity. (author) 23 refs.

  10. Conducting Polymer Based Nanobiosensors

    Directory of Open Access Journals (Sweden)

    Chul Soon Park

    2016-06-01

    Full Text Available In recent years, conducting polymer (CP nanomaterials have been used in a variety of fields, such as in energy, environmental, and biomedical applications, owing to their outstanding chemical and physical properties compared to conventional metal materials. In particular, nanobiosensors based on CP nanomaterials exhibit excellent performance sensing target molecules. The performance of CP nanobiosensors varies based on their size, shape, conductivity, and morphology, among other characteristics. Therefore, in this review, we provide an overview of the techniques commonly used to fabricate novel CP nanomaterials and their biosensor applications, including aptasensors, field-effect transistor (FET biosensors, human sense mimicking biosensors, and immunoassays. We also discuss prospects for state-of-the-art nanobiosensors using CP nanomaterials by focusing on strategies to overcome the current limitations.

  11. Photorefractivity of triphenylamine polymers

    Science.gov (United States)

    Tsujimura, S.; Kinashi, K.; Sakai, W.; Tsutsumi, N.

    2012-10-01

    We present here the enhanced photorefractive performance and dynamic holographic image of poly(4-diphenylamino)styrene (PDAS)-based photorefractive polymeric composites (PPCs). PDAS and FDCST were synthesized as a photoconductive polymer and a nonlinear optical (NLO) dye, respectively. PPC films including PDAS, TPA (or ECZ), FDCST, and PCBM were investigated. The photorefractive quantities of the PDAS-based PPCs were measured by a degenerate four-wave mixing (DFWM) technique. Additionally, the dynamic holographic images were recorded through an appropriate PDAS-based PPC. Those dynamic holographic images clearly duplicate the original motion with high-speed quality. The present approach provides a promising candidate for the future application of dynamic holographic displays.

  12. Self-healing polymers

    Science.gov (United States)

    Klein, Daniel J. (Inventor)

    2011-01-01

    A three dimensional structure fabricated from a self-healing polymeric material, comprising poly(ester amides) obtained from ethylene glycol, azelaic acid and 1,1-aminoundecanoic acid, wherein polymeric material has a melt index above 2.5 g/10 min. as determined by ASTM D1238 at 190.degree. C. and 2.16kg, impact resistance and ductility sufficient to resist cracking and brittle fracture upon impact by a 9 mm bullet fired at a temperature of about 29.degree. C. at subsonic speed in a range from about 800 feet/sec to about 1000 feet/sec. It has been determined that the important factors necessary for self-healing behavior of polymers include sufficient impact strength, control of the degree of crystallinity, low melting point and the ability to instantly melt at impacted area.

  13. Annealed Scaling for a Charged Polymer

    Energy Technology Data Exchange (ETDEWEB)

    Caravenna, F., E-mail: francesco.caravenna@unimib.it [Università degli Studi di Milano-Bicocca, Dipartimento di Matematica e Applicazioni (Italy); Hollander, F. den, E-mail: denholla@math.leidenuniv.nl [Leiden University, Mathematical Institute (Netherlands); Pétrélis, N., E-mail: nicolas.petrelis@univ-nantes.fr [Université de Nantes, Laboratoire de Mathématiques Jean Leray UMR 6629 (France); Poisat, J., E-mail: poisat@ceremade.dauphine.fr [Université Paris-Dauphine, PSL Research University, CEREMADE, UMR 7534 (France)

    2016-03-15

    This paper studies an undirected polymer chain living on the one-dimensional integer lattice and carrying i.i.d. random charges. Each self-intersection of the polymer chain contributes to the interaction Hamiltonian an energy that is equal to the product of the charges of the two monomers that meet. The joint probability distribution for the polymer chain and the charges is given by the Gibbs distribution associated with the interaction Hamiltonian. The focus is on the annealed free energy per monomer in the limit as the length of the polymer chain tends to infinity. We derive a spectral representation for the free energy and use this to prove that there is a critical curve in the parameter plane of charge bias versus inverse temperature separating a ballistic phase from a subballistic phase. We show that the phase transition is first order. We prove large deviation principles for the laws of the empirical speed and the empirical charge, and derive a spectral representation for the associated rate functions. Interestingly, in both phases both rate functions exhibit flat pieces, which correspond to an inhomogeneous strategy for the polymer to realise a large deviation. The large deviation principles in turn lead to laws of large numbers and central limit theorems. We identify the scaling behaviour of the critical curve for small and for large charge bias. In addition, we identify the scaling behaviour of the free energy for small charge bias and small inverse temperature. Both are linked to an associated Sturm-Liouville eigenvalue problem. A key tool in our analysis is the Ray-Knight formula for the local times of the one-dimensional simple random walk. This formula is exploited to derive a closed form expression for the generating function of the annealed partition function, and for several related quantities. This expression in turn serves as the starting point for the derivation of the spectral representation for the free energy, and for the scaling theorems

  14. Annealed Scaling for a Charged Polymer

    International Nuclear Information System (INIS)

    Caravenna, F.; Hollander, F. den; Pétrélis, N.; Poisat, J.

    2016-01-01

    This paper studies an undirected polymer chain living on the one-dimensional integer lattice and carrying i.i.d. random charges. Each self-intersection of the polymer chain contributes to the interaction Hamiltonian an energy that is equal to the product of the charges of the two monomers that meet. The joint probability distribution for the polymer chain and the charges is given by the Gibbs distribution associated with the interaction Hamiltonian. The focus is on the annealed free energy per monomer in the limit as the length of the polymer chain tends to infinity. We derive a spectral representation for the free energy and use this to prove that there is a critical curve in the parameter plane of charge bias versus inverse temperature separating a ballistic phase from a subballistic phase. We show that the phase transition is first order. We prove large deviation principles for the laws of the empirical speed and the empirical charge, and derive a spectral representation for the associated rate functions. Interestingly, in both phases both rate functions exhibit flat pieces, which correspond to an inhomogeneous strategy for the polymer to realise a large deviation. The large deviation principles in turn lead to laws of large numbers and central limit theorems. We identify the scaling behaviour of the critical curve for small and for large charge bias. In addition, we identify the scaling behaviour of the free energy for small charge bias and small inverse temperature. Both are linked to an associated Sturm-Liouville eigenvalue problem. A key tool in our analysis is the Ray-Knight formula for the local times of the one-dimensional simple random walk. This formula is exploited to derive a closed form expression for the generating function of the annealed partition function, and for several related quantities. This expression in turn serves as the starting point for the derivation of the spectral representation for the free energy, and for the scaling theorems

  15. Electrochromic in conjugated polymers

    International Nuclear Information System (INIS)

    Picado Valenzuela, Alfredo

    2007-01-01

    This revision considered object the description of one of the materials with the greatest potential in the field of electrochromic (mainly in the visible region): the conjugated polymers (CP), area of enormous potential both now and in a short time ahead. The CP are insulating materials and organic semiconductors in a state not doped. They can be doped positively or negatively being observed a significant increase in the conductivity and being generated a color change in these materials. The understanding of how optical properties vary based on the chemical structure of the polymer or its mixtures and more precisely of the alternatives that can be entered into the conjugated system or π system to obtain a material that besides to be flexible, environmentally stable, presents the colored states. The revision was centred chiefly in the polypyrrole (Ppy), the polythiophene (PTh) and their derivatives such as poly (3.4-ethylenedioxythiophene) (PEDOT). The advantage of using monomers with variable structure, to adjust the composition of the copolymer, or to blend with the PC, allows to obtain a variety of colored states that can be modulated through the visible spectrum and even with applications to wavelengths outside of this region. Because the PC presented at least two different colored states can be varied continuously as a function of the voltage applied. In some cases, they may submit multicoloured statements, which offers a range of possibilities for their application in flexible electronic devices type screens and windows. Applications include smart windows, camouflage clothing and data screens. This type of material is emerging as one of the substitutes of the traditional inorganic semiconductor, with the advantage of its low cost, high flexibility and the possibility to generate multiple colors through the handling of the monomers in the structure and control of energy of his band gap. (author) [es

  16. Monitoring of polymer melt processing

    International Nuclear Information System (INIS)

    Alig, Ingo; Steinhoff, Bernd; Lellinger, Dirk

    2010-01-01

    The paper reviews the state-of-the-art of in-line and on-line monitoring during polymer melt processing by compounding, extrusion and injection moulding. Different spectroscopic and scattering techniques as well as conductivity and viscosity measurements are reviewed and compared concerning their potential for different process applications. In addition to information on chemical composition and state of the process, the in situ detection of morphology, which is of specific interest for multiphase polymer systems such as polymer composites and polymer blends, is described in detail. For these systems, the product properties strongly depend on the phase or filler morphology created during processing. Examples for optical (UV/vis, NIR) and ultrasonic attenuation spectra recorded during extrusion are given, which were found to be sensitive to the chemical composition as well as to size and degree of dispersion of micro or nanofillers in the polymer matrix. By small-angle light scattering experiments, process-induced structures were detected in blends of incompatible polymers during compounding. Using conductivity measurements during extrusion, the influence of processing conditions on the electrical conductivity of polymer melts with conductive fillers (carbon black or carbon nanotubes) was monitored. (topical review)

  17. Design of a minimum emittance nBA lattice

    Science.gov (United States)

    Lee, S. Y.

    1998-04-01

    An attempt to design a minimum emittance n-bend achromat (nBA) lattice has been made. One distinct feature is that dipoles with two different lengths were used. As a multiple bend achromat, five bend achromat lattices with six superperiod were designed. The obtained emittace is three times larger than the theoretical minimum. Tunes were chosen to avoid third order resonances. In order to correct first and second order chromaticities, eight family sextupoles were placed. The obtained emittance of five bend achromat lattices is almost equal to the minimum emittance of five bend achromat lattice consisting of dipoles with equal length.

  18. [Hospitals failing minimum volumes in 2004: reasons and consequences].

    Science.gov (United States)

    Geraedts, M; Kühnen, C; Cruppé, W de; Blum, K; Ohmann, C

    2008-02-01

    In 2004 Germany introduced annual minimum volumes nationwide on five surgical procedures: kidney, liver, stem cell transplantation, complex oesophageal, and pancreatic interventions. Hospitals that fail to reach the minimum volumes are no longer allowed to perform the respective procedures unless they raise one of eight legally accepted exceptions. The goal of our study was to investigate how many hospitals fell short of the minimum volumes in 2004, whether and how this was justified, and whether hospitals that failed the requirements experienced any consequences. We analysed data on meeting the minimum volume requirements in 2004 that all German hospitals were obliged to publish as part of their biannual structured quality reports. We performed telephone interviews: a) with all hospitals not achieving the minimum volumes for complex oesophageal, and pancreatic interventions, and b) with the national umbrella organisations of all German sickness funds. In 2004, one quarter of all German acute care hospitals (N=485) performed 23,128 procedures where minimum volumes applied. 197 hospitals (41%) did not meet at least one of the minimum volumes. These hospitals performed N=715 procedures (3.1%) where the minimum volumes were not met. In 43% of these cases the hospitals raised legally accepted exceptions. In 33% of the cases the hospitals argued using reasons that were not legally acknowledged. 69% of those hospitals that failed to achieve the minimum volumes for complex oesophageal and pancreatic interventions did not experience any consequences from the sickness funds. However, one third of those hospitals reported that the sickness funds addressed the issue and partially announced consequences for the future. The sickness funds' umbrella organisations stated that there were only sparse activities related to the minimum volumes and that neither uniform registrations nor uniform proceedings in case of infringements of the standards had been agreed upon. In spite of the

  19. On the road again: traffic fatalities and auto insurance minimums

    Directory of Open Access Journals (Sweden)

    Pavel A. Yakovlev

    2018-03-01

    Full Text Available Prior research on policy-induced moral hazard effects in the auto insurance market has focused on the impact of compulsory insurance, no-fault liability, and tort liability laws on traffic fatalities. In contrast, this paper examines the moral hazard effect of a previously overlooked policy variable: minimum auto insurance coverage. We hypothesize that state-mandated auto insurance minimums may “over-insure” some drivers, lowering their incentives to drive carefully. Using a longitudinal panel of American states from 1982 to 2006, we find that policy-induced increases in auto insurance minimums are associated with higher traffic fatality rates, ceteris paribus.

  20. Minimum-Cost Reachability for Priced Timed Automata

    DEFF Research Database (Denmark)

    Behrmann, Gerd; Fehnker, Ansgar; Hune, Thomas Seidelin

    2001-01-01

    This paper introduces the model of linearly priced timed automata as an extension of timed automata, with prices on both transitions and locations. For this model we consider the minimum-cost reachability problem: i.e. given a linearly priced timed automaton and a target state, determine...... the minimum cost of executions from the initial state to the target state. This problem generalizes the minimum-time reachability problem for ordinary timed automata. We prove decidability of this problem by offering an algorithmic solution, which is based on a combination of branch-and-bound techniques...