Home  About us  Contact
 

Standard Specifications (standard + specifications)

Distribution by Scientific Domains
Polymers and Materials Science60%

Selected Abstracts

Reliability in grid computing systems,

CONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 8 2009
Christopher Dabrowski
Abstract In recent years, grid technology has emerged as an important tool for solving compute-intensive problems within the scientific community and in industry. To further the development and adoption of this technology, researchers and practitioners from different disciplines have collaborated to produce standard specifications for implementing large-scale, interoperable grid systems. The focus of this activity has been the Open Grid Forum, but other standards development organizations have also produced specifications that are used in grid systems. To date, these specifications have provided the basis for a growing number of operational grid systems used in scientific and industrial applications. However, if the growth of grid technology is to continue, it will be important that grid systems also provide high reliability. In particular, it will be critical to ensure that grid systems are reliable as they continue to grow in scale, exhibit greater dynamism, and become more heterogeneous in composition. Ensuring grid system reliability in turn requires that the specifications used to build these systems fully support reliable grid services. This study surveys work on grid reliability that has been done in recent years and reviews progress made toward achieving these goals. The survey identifies important issues and problems that researchers are working to overcome in order to develop reliability methods for large-scale, heterogeneous, dynamic environments. The survey also illuminates reliability issues relating to standard specifications used in grid systems, identifying existing specifications that may need to be evolved and areas where new specifications are needed to better support the reliability. Published in 2009 by John Wiley & Sons, Ltd. [source]

CEO Pay-For-Performance Heterogeneity Using Quantile Regression

FINANCIAL REVIEW, Issue 1 2010
Kevin F. Hallock
G3; J33; M52 Abstract We provide some examples of how quantile regression can be used to investigate heterogeneity in pay-firm size and pay-performance relationships for U.S. CEOs. For example, do conditionally (predicted) high-wage managers have a stronger relationship between pay and performance than conditionally low-wage managers? Our results using data over a decade show, for some standard specifications, there is considerable heterogeneity in the returns-to-firm performance across the conditional distribution of wages. Quantile regression adds substantially to our understanding of the pay-performance relationship. This heterogeneity is masked when using more standard empirical techniques. [source]

Environmentally friendly mixed tannin/lignin wood resins

JOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2008
Hong Lei
Abstract We obtained lignin-based wood adhesives satisfying the requirements of relevant international standards for the manufacture of wood particleboard. These were based on two different low-molecular-mass lignins. These lignin-based wood adhesives did not use any formaldehyde in their formulation; formaldehyde was substituted with a nonvolatile nontoxic aldehyde, namely, glyoxal. The last formaldehyde present, contributed by a fortifying synthetic phenol,formaldehyde resin, was also eliminated by the substitution of the phenol,formaldehyde resin with a natural, vegetable polyflavonoid tannin extract to which no aldehyde was added. This substitution brought the total content of natural material up to 80 wt % of the total adhesive. The adhesives yielded good internal bond strength results of the panels, enough to pass relevant international standard specifications for interior-grade panels. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source]

Lignin-based polycondensation resins for wood adhesives

JOURNAL OF APPLIED POLYMER SCIENCE, Issue 3 2007
N.-E. El Mansouri
Abstract Lignin-based wood adhesives are obtained that satisfy the requirements of relevant international standards for the manufacture of exterior-grade wood particleboard. Formulations based on low molecular mass lignin and presenting an increase in the relative proportion of reactive points yield better results than the higher molecular mass lignin used in the past. These lignins allow a higher proportion of hydroxymethylation during preparation of methylolated lignins. These lignin-based adhesives also yield acceptable results at particleboard pressing times that are sufficiently low to be of industrial significance. Lignin-based wood adhesives, in which a nonvolatile nontoxic aldehyde (glyoxal) is substituted for formaldehyde in their preparation, are prepared and tested for application to wood panels such as particleboard. The adhesives yield good internal bond strength results for the panels, which are good enough to comfortably pass relevant international standard specifications for exterior-grade panels. The adhesives also show sufficient reactivity to yield panels in press times comparable to that of formaldehyde-based commercial adhesives. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1690,1699, 2007 [source]

Injectable acrylic bone cements for vertebroplasty with improved properties

JOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 1 2004
Raúl García Carrodeguas
Abstract Currently commercially available acrylic bone cements lack adequate radiopacity and viscosity when they are used in percutaneous vertebroplasty (PVP). In this work improved formulations of radiopaque and injectable poly(methyl methacrylate) bone cements were prepared with different amounts (10,50 wt.%) of BaTiO3 or SrTiO3 particles as the radiopaque agent. Two sets of cements were prepared by using untreated or silanated radiopaque particles, respectively. The influence of the content and nature of the radiopaque agent as well as its silanation with 3-(trimethoxysilyl) propyl methacrylate (,-MPS), on the curing parameters, residual monomer content, radiopacity, mechanical properties, and injectability of the resulting materials, was examined. Doughing and setting times, maximum temperature, and compressive strength of all formulations fulfilled the requirements of standard specifications, with values of peak temperature in the range 57,72 °C and those of compressive strength between 114 and 135 MPa. Formulations containing at least 20 wt.% BaTiO3 or SrTiO3 had radiopacities equal to or greater than that corresponding to 2 mm of Al as required for surgical plastics. Injectability of any of the formulations provided 75,80 wt.% of the total mass manually injected through a conventional biopsy needle 4 min after mixing. Silanation of the BaTiO3 or SrTiO3 particles led to formulations with improved mechanical properties and injectability compared to those obtained with the untreated fillers. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 68B: 94,104, 2004 [source]