348 research outputs found
Nematic-isotropic phase transition in diblock fused-sphere chain fluids
No full textA density-functional theory for the isotropic-nematic phase transition in fluids of rigid or semiflexible fused hard-sphere chains, developed previously by the authors, is extended to diblock chains each consisting of both a rigid and a flexible part. The theory is compared with recent Monte Carlo simulation results of McBride The theoretical results for the variation of pressure and nematic order parameter with density agree well with the simulation data over density ranges where the simulations find isotropic and nematic phases.PT: J; CR: BOUBLIK T, 1974, MOL PHYS, V27, P1415 BOUBLIK T, 1975, J CHEM PHYS, V63, P4084 BOUBLIK T, 1981, MOL PHYS, V44, P1369 BOUBLIK T, 1989, MOL PHYS, V68, P191 COTTER MA, 1977, J CHEM PHYS, V66, P1098 COTTER MA, 1978, PHYS REV A, V18, P2669 FORSMAN J, 2003, J CHEM PHYS, V119, P1889 FYNEWEVER H, 1998, J CHEM PHYS, V108, P1636 HONNELL KG, 1989, J CHEM PHYS, V90, P1841 JAFFER KM, 1999, J CHEM PHYS, V110, P11630 JAFFER KM, 2001, J CHEM PHYS, V114, P3314 KHOKHLOV AR, 1981, PHYSICA A, V108, P546 KHOKHLOV AR, 1982, PHYSICA A, V112, P605 MCBRIDE C, 2001, PHYS REV E 1, V64 MCBRIDE C, 2002, J CHEM PHYS, V117, P10370 MEHTA SD, 1996, J PHYS CHEM-US, V100, P10408 MULLER M, 2003, J CHEM PHYS, V118, P2929 SATO T, 1996, ADV POLYM SCI, V126, P85 TIAN P, 2001, J CHEM PHYS, V115, P9055 VARGA S, 2000, MOL PHYS, V98, P693 VEGA C, 1994, J CHEM PHYS, V100, P6727 WERTHEIM MS, 1987, J CHEM PHYS, V87, P7323 WHITTLE M, 1991, MOL PHYS, V72, P247 WILLIAMSON DC, 1995, MOL PHYS, V86, P819 WILLIAMSON DC, 1998, J CHEM PHYS, V108, P10294 YETHIRAJ A, 1998, MOL PHYS, V93, P693 ZHOU YQ, 1995, J CHEM PHYS, V103, P2688; NR: 27; TC: 3; J9: PHYS REV E; PN: Part 1; PG: 4; GA: 835RHSource type: Electronic(1
Islamic Insurance: Trends, Opportunities and the Future of Takaful
No full textOffering an overview of the Takaful Islamic Insurance industry, this book provides in-depth insight from leading Shari\u27ah scholars and examines the challenges facing the Islamic insurance industry. This industry has gone through a rapid phase of expansion, with numerous Takaful operations in 30 countries and Takaful premiums covering non-life and life. This growth gives rise to both opportunities and challenges to traditional and Islamic financial institutions in the provision, distribution and underwriting of Islamic insurance products. Edited by the best-selling author Sohail Jaffer with contributions from 21 specialist contributors, this is the only book to explore every aspect of Islamic Insurance. Topics covered include: Takaful models and their development, Re-Takaful, retailing Takaful, distributing through joint ventures, innovations in the Northern and Southern African markets, integrating Takaful within conventional bancassurance, legal, regulatory and operational issues and the rating of Takaful companies
The efficacy of community-based rehabilitation for children with or at significant risk of intellectual disabilities in low and middle income countries : a review.
No full textThe nematic-isotropic phase transition in linear fused hard-sphere chain fluids
No full textWe present a modification of the generalized Flory dimer theory to investigate the nematic (N) to isotropic (I) phase transition in chain fluids. We focus on rigid linear fused hard-sphere (LFHS) chain molecules in this study. A generalized density functional theory is developed, which involves an angular weighting of the dimer reference fluid as suggested by decoupling theory, to accommodate nematic ordering in the system. A key ingredient of this theory is the calculation of the exact excluded volume for a pair of molecules in an arbitrary relative orientation, which extends the recent work by Williamson and Jackson for linear tangent hard-sphere chain molecules to the case of linear fused hard-sphere chains with arbitrary intramolecular bondlength. The present results for the N-I transition are compared with previous theories and with computer simulations. In comparison with previous studies, the results show much better agreement with simulations for both the coexistence densities and the nematic order parameter at the transition. (C) 1999 American Institute of Physics. [S0021-9606(99)51023-4].PT: J; CR: BOLHUIS P, 1997, J CHEM PHYS, V106, P666 BOUBLIK T, 1977, CHEM PHYS LETT, V46, P315 BOUBLIK T, 1989, MOL PHYS, V68, P191 CARNAHAN NF, 1969, J CHEM PHYS, V51, P635 CHAMOUX A, 1998, MOL PHYS, V93, P649 CHANDLER D, 1976, J CHEM PHYS, V65, P2925 CHANG J, 1994, CHEM ENG SCI, V49, P2777 CHAPMAN WG, 1988, MOL PHYS, V65, P1057 CHIEW YC, 1990, MOL PHYS, V70, P129 COSTA LA, 1995, J CHEM PHYS, V102, P6212 CURRO JG, 1987, MACROMOLECULES, V20, P1928 FYNEWEVER H, 1998, J CHEM PHYS, V108, P1636 HONNELL KG, 1989, J CHEM PHYS, V90, P1841 JAFFER KM, 1999, THESIS U GUELPH KIERLIK E, 1992, J CHEM PHYS, V97, P9222 KIERLIK E, 1993, J CHEM PHYS, V99, P3950 LEE SD, 1987, J CHEM PHYS, V87, P4972 MEHTA SD, 1996, J PHYS CHEM-US, V100, P10408 ONSAGER L, 1949, ANN NY ACAD SCI, V51, P627 PADILLA P, 1997, J CHEM PHYS, V106, P10299 PARSONS JD, 1979, PHYS REV A, V19, P1225 PRATT LR, 1977, J CHEM PHYS, V66, P147 SCHWEIZER KS, 1988, MACROMOLECULES, V21, P3070 SEN S, 1994, J CHEM PHYS, V101, P9010 SOMOZA AM, 1989, J CHEM PHYS, V91, P517 STELL G, 1964, EQUILIBRIUM THEORY C TILDESLEY DJ, 1980, MOL PHYS, V41, P85 VEGA C, 1994, J CHEM PHYS, V100, P6727 WERTHEIM MS, 1987, J CHEM PHYS, V87, P7323 WHITTLE M, 1991, MOL PHYS, V72, P247 WILLIAMSON DC, 1995, MOL PHYS, V86, P819 WILLIAMSON DC, 1998, J CHEM PHYS, V108, P10294 WOODWARD CE, 1994, J CHEM PHYS, V100, P3181 YETHIRAJ A, 1993, J CHEM PHYS, V98, P1635 YETHIRAJ A, 1995, J CHEM PHYS, V102, P5499 YETHIRAJ A, 1998, MOL PHYS, V93, P693 ZHOU YQ, 1995, J CHEM PHYS, V103, P2688; NR: 37; TC: 15; J9: J CHEM PHYS; PG: 13; GA: 200CHSource type: Electronic(1
The nematic-isotropic phase transition in semiflexible fused hard-sphere chain fluids
No full textA density-functional theory of the isotropic-nematic phase transition in both rigid and semiflexible hard-sphere chain fluids is described. The theory is based on an exact analytical evaluation of the excluded volume and second virial coefficient B-2 for rigid chain molecules, which demonstrates that B-2 in these cases is equivalent to that of a binary mixture of hard spheres and hard diatomic molecules. It is assumed that the same binary-mixture representation applies to semiflexible chains, while scaled particle theory is used to obtain the properties of the fluid at arbitrary densities. The results of the theory are in very good agreement with Monte Carlo (MC) simulation data for rigid tangent hard-sphere chains, but in lesser agreement with available MC studies of rigid fused hard-sphere chains. We find that there is reasonable agreement between the theory and MC data for semiflexible tangent chains, which improves with increasing chain length. The behavior predicted by the theory for semiflexible chains is contrasted with that given by the Khokhlov and Semenov theory of nematic ordering of wormlike polymer chains. (C) 2001 American Institute of Physics.PT: J; CR: BOUBLIK T, 1974, MOL PHYS, V27, P1415 BOUBLIK T, 1975, J CHEM PHYS, V63, P4084 BOUBLIK T, 1977, CHEM PHYS LETT, V46, P315 BOUBLIK T, 1981, MOL PHYS, V44, P1369 BOUBLIK T, 1989, MOL PHYS, V68, P191 BOUBLIK T, 1990, J CHEM PHYS, V93, P730 CARNAHAN NF, 1969, J CHEM PHYS, V51, P635 CHAPMAN WG, 1988, MOL PHYS, V65, P1057 CHEN ZY, 1993, MACROMOLECULES, V26, P3419 COSTA LA, 1995, J CHEM PHYS, V102, P6212 COTTER MA, 1977, J CHEM PHYS, V66, P1098 COTTER MA, 1978, PHYS REV A, V18, P2669 DIJKSTRA M, 1995, PHYS REV E A, V51, P5891 ESCOBEDO FA, 1997, J CHEM PHYS, V106, P9858 FYNEWEVER H, 1998, J CHEM PHYS, V108, P1636 GAO J, 1989, J CHEM PHYS, V91, P3168 HONNELL KG, 1989, J CHEM PHYS, V90, P1841 JAFFER KM, 1999, J CHEM PHYS, V110, P11630 KHOKHLOV AR, 1981, PHYSICA A, V108, P546 KHOKHLOV AR, 1982, PHYSICA A, V112, P605 LEE SD, 1987, J CHEM PHYS, V87, P4972 MEHTA SD, 1996, J PHYS CHEM-US, V100, P10408 MULLER M, 1998, PHYS REV E, V57, P6973 ONSAGER L, 1949, ANN NY ACAD SCI, V51, P627 PARSONS JD, 1979, PHYS REV A, V19, P1225 PATRA CN, 2000, J CHEM PHYS, V112, P1579 SEN S, 1994, J CHEM PHYS, V101, P9010 VARGA S, 2000, MOL PHYS, V98, P693 VEGA C, 1994, J CHEM PHYS, V100, P6727 WALSH JM, 1990, J PHYS CHEM-US, V94, P5115 WERTHEIM MS, 1987, J CHEM PHYS, V87, P7323 WHITTLE M, 1991, MOL PHYS, V72, P247 WILLIAMSON DC, 1995, MOL PHYS, V86, P819 WILLIAMSON DC, 1998, J CHEM PHYS, V108, P10294 YETHIRAJ A, 1992, MACROMOLECULES, V25, P3979 YETHIRAJ A, 1995, J CHEM PHYS, V102, P5499 YETHIRAJ A, 1995, J CHEM PHYS, V102, P6874 YETHIRAJ A, 1998, MOL PHYS, V93, P693 ZHOU YQ, 1995, J CHEM PHYS, V103, P2688; NR: 39; TC: 8; J9: J CHEM PHYS; PG: 11; GA: 397THSource type: Electronic(1
Immobilization of Bacteria with Probiotic Potential (Lactobacillus acidophillus, Pediococcus acidolactici acidolactici) in Polymeric Matrices of Alginate, Chitosan and Maltodextrin for the Preservation of their Stability and Cell Viability
No full textDigitalEn la presente investigación se evaluaron los sistemas de gelificación iónica o secado por atomización para la inmovilización de L. acidophillus y P. acidolactici con matrices poliméricas de alginato, quitosano y maltodextrina con el objetivo de verificar la viabilidad celular de los microorganismos durante su almacenamiento a través del tiempo a condiciones ambientales; estas bacterias tienen amplios estudios en los últimos años como aditivos funcionales en la industria pecuaria. La producción de la biomasa se llevó a cabo a escala de 1kg; seguido, se diseñaron cuatro formulaciones para la técnica de gelificación iónica: F1, F2 alginato de sodio 2% y 4%; F3, F4 recubrimiento con quitosano 0,2% y 0.4%; y dos formulaciones para secado por atomización: F5, F6 maltodextrina 40 °Bx y 50 °Bx. Adicionalmente, se determinaron las características morfológicas y caracterización química (Espectroscopia Raman e IR) de la matriz de inmovilización, junto con un estudio a través del tiempo de la viabilidad celular y la eficiencia de inmovilización. La mayor eficiencia de inmovilización se obtuvo en los inmovilizados de alginato-quitosano F3, F4 con porcentajes de 85,7% y 100,0% respectivamente. El porcentaje de viabilidad celular a través del tiempo varió en los diferentes sistemas de inmovilización, los de mayor protección fueron los secados por atomización F5 y F6, en estos sistemas la reducción de 1 Log10 se observó hasta después de 130 y 170 días respectivamente, mientras que en la gelificación iónica la reducción de 1 Log10 se observó hasta después de 75, 80, 80 y 120 días respectivamente. El secado por atomización fue la técnica con mayor preservación de L. acidophillus y P. acidolactici a través del tiempo, siendo una técnica viable para la inmovilización de este tipo de bacterias que depende en gran medida de los parámetros de secado y de las concentraciones de la maltodextrina.In this research paper, ionic gelation systems and spray drying systems were evaluated for the immobilization of L. acidophillus y P. acidolactici with polymeric matrices of alginate, chitosan, and maltodextrin in order to verify the cell viability of the microorganisms during storage over time at environmental conditions; these bacterias have been extensively studied in recent years as functional additives in the livestock industry. Biomass production was carried out at a 1kg scale; then, four formulations were designed for the ionic gelation technique were formulated: F1, F2 sodium alginate 2% & 4%; F3, F4 Coated 0,2% & 0.4%; and two formulations for spray drying: F5, F6 maltodextrin 40° Bx & 50° Bx. Additionally, the size and morphology of the immobilization matrix were determined and its chemical characterization (Spectroscopy Raman & IR) was performed to identify and evaluate its stability and immobilization efficiency. The highest immobilization efficiency was obtained in the alginate-chitosan immobilized (F3 and F4) with percentages of 85,7% and 100,0% respectively. The percentage of cell varied in the different immobilization systems, those with the highest protection were spray drying F5 and F6, in these systems the reduction of 1Log10 was observed until after 130 and 170 days respectively, while in ionic gelification F1, F2, F3 and F4 the reduction of 1Log10 was observed until after 75, 80, 80, and 120 days respectively. The spray drying system was the technique with the highest preservation of L. acidophillus y P. acidolactici over time, being a viable technique for the immobilization of this type of bacteria that depends to a great extent on the drying parameters and the concentrations of the maltodextrin.Introducción 22
Objetivos 27
Objetivo General 27
Objetivos Específicos 27
Cuerpo del Trabajo 28
Marco Referencial 28
Alimentos Funcionales (Modulador Intestinal) 28
Bacterias Probióticas (Ingrediente Alimentario Funcional) 28
Sistemas de Inmovilización 30
Matrices de Inmovilización Poliméricas. 31
Gelificación Iónica. 33
Secado por Atomización. 36
Metodología 40
Materiales 40
Producción de Bacterias Probióticas 41
Activación Bacteriana 41
Crecimiento Bacteriano 41
Purificación Bacteriana 42
Formulación 42
Gelificación Iónica 44
Secado por Atomización 45
Caracterización Fisicoquímica de los Inmovilizados 45
Microscopia Electrónica de Barrido (SEM) y Microscopia Óptica 45
Espectroscopia Raman e Infrarrojo 45
Viabilidad Celular y Estabilidad de los Inmovilizados 46
Resultados y Análisis de Resultados 48
Cultivo de Bacterias Probióticas 48
Activación Bacteriana con Medios MRS 48
Crecimiento Bacteriano en Medio no Comercial 49
Purificación del Consorcio Probiótico 51
Sistemas de Inmovilización y Caracterización Morfológica de Inmovilizados 51
Inmovilización por Gelificación Iónica 51
Caracterización de Inmovilizados con Microscopia Óptica (MO). 53
Inmovilización con Secado por Atomización 55
Caracterización de Inmovilizados con Microscopia Electrónica de Barrido (SEM). 55
Caracterización Química de los Inmovilizados 57
Análisis Raman 57
Análisis Infrarrojo 60
Viabilidad Celular y Estabilidad de Inmovilizados a Través del Tiempo 62
Eficiencia de Inmovilización (Ei). 62
Viabilidad Celular en Almacenamiento 64
Conclusiones 71
Recomendaciones 73
Referencias Bibliográficas 74
Apéndices 83MaestríaMagíster en BiotecnologíaUniversidad de Santande
SSD-Based Workload Characteristics and Their Performance Implications
No full textThis repo contains blocktrace from YCSB benchmark run on a RocksDB KV store hosted on a ext4 File System.
More details can be found in the README file and also in our ACM TOS Paper here: https://dl.acm.org/doi/10.1145/3423137
Please cite our paper, if the trace is useful in your research:
@article{10.1145/3423137,
author = {Yadgar, Gala and Gabel, Moshe and Jaffer, Shehbaz and Schroeder, Bianca},
title = {SSD-Based Workload Characteristics and Their Performance Implications},
year = {2021},
issue_date = {January 2021},
publisher = {Association for Computing Machinery}, address = {New York, NY, USA},
volume = {17},
number = {1},
issn = {1553-3077},
url = {https://doi.org/10.1145/3423137},
doi = {10.1145/3423137},
abstract = {Storage systems are designed and optimized relying on wisdom derived from analysis studies of file-system and block-level workloads. However, while SSDs are becoming a dominant building block in many storage systems, their design continues to build on knowledge derived from analysis targeted at hard disk optimization. Though still valuable, it does not cover important aspects relevant for SSD performance. In a sense, we are “searching under the streetlight,” possibly missing important opportunities for optimizing storage system design.We present the first I/O workload analysis designed with SSDs in mind. We characterize traces from four repositories and examine their “temperature” ranges, sensitivity to page size, and “logical locality.” We then take the first step towards correlating these characteristics with three standard performance metrics: write amplification, read amplification, and flash read costs. Our results show that SSD-specific characteristics strongly affect performance, often in surprising ways.}, journal = {ACM Trans. Storage}, month = jan, articleno = {8}, numpages = {26}, keywords = {locality, workload characterization, I/O workload analysis, SSD}
}Paper BibTex:
@article{10.1145/3423137,
author = {Yadgar, Gala and Gabel, MOSHE and Jaffer, Shehbaz and Schroeder, Bianca},
title = {SSD-Based Workload Characteristics and Their Performance Implications},
year = {2021},
issue_date = {January 2021},
publisher = {Association for Computing Machinery},
address = {New York, NY, USA},
volume = {17},
number = {1},
issn = {1553-3077},
url = {https://doi.org/10.1145/3423137},
doi = {10.1145/3423137},
abstract = {Storage systems are designed and optimized relying on wisdom derived from analysis studies of file-system and block-level workloads. However, while SSDs are becoming a dominant building block in many storage systems, their design continues to build on knowledge derived from analysis targeted at hard disk optimization. Though still valuable, it does not cover important aspects relevant for SSD performance. In a sense, we are "searching under the streetlight," possibly missing important opportunities for optimizing storage system design.We present the first I/O workload analysis designed with SSDs in mind. We characterize traces from four repositories and examine their "temperature" ranges, sensitivity to page size, and "logical locality." We then take the first step towards correlating these characteristics with three standard performance metrics: write amplification, read amplification, and flash read costs. Our results show that SSD-specific characteristics strongly affect performance, often in surprising ways.},
journal = {ACM Trans. Storage},
month = jan,
articleno = {8},
numpages = {26},
keywords = {locality, workload characterization, I/O workload analysis, SSD}
Conditional Mean Estimation in Gaussian Noise: A Meta Derivative Identity With Applications
No full textConsider a channel Y= X+ N where X is an n -dimensional random vector, and N is a multivariate Gaussian vector with a full-rank covariance matrix KN. The object under consideration in this paper is the conditional mean of X given Y=y , that is {E} XY=y. Several identities in the literature connect EXY=y to other quantities such as the conditional variance, score functions, and higher-order conditional moments. The objective of this paper is to provide a unifying view of these identities. In the first part of the paper, a general derivative identity for the conditional mean estimator is derived. Specifically, for the Markov chain U {X} {Y}, it is shown that the Jacobian matrix of {E}[{U}- {Y}=y is given by K {N}-1} {{Cov}} {X},{U}-{Y}=y where {Cov}} ({X},{U}- {Y}={y) is the conditional covariance. In the second part of the paper, via various choices of the random vector {U} , the new identity is used to recover and generalize many of the known identities and derive some new identities. First, a simple proof of the Hatsel and Nolte identity for the conditional variance is shown. Second, a simple proof of the recursive identity due to Jaffer is provided. The Jaffer identity is then further explored, and several equivalent statements are derived, such as an identity for the higher-order conditional expectation (i.e., {E}[{X/k}|{Y} ) in terms of the derivatives of the conditional expectation. Third, a new fundamental connection between the conditional cumulants and the conditional expectation is demonstrated. In particular, in the univariate case, it is shown that the k -th derivative of the conditional expectation is proportional to the (k+1) -th conditional cumulant. A similar expression is derived in the multivariate case
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