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Product Data (product + data)

Distribution by Scientific Domains

Business, Economics, Finance and Accounting	40%

Selected Abstracts

Gas-phase reaction of hydroxyl radicals with m -, o - and p -cresol

INTERNATIONAL JOURNAL OF CHEMICAL KINETICS, Issue 9 2006
Cecile Coeur-Tourneur
The gas-phase reaction of oxygenated aromatic compounds m -cresol, o -cresol, and p -cresol with hydroxyl radicals has been studied by GC-MS. Experiments have been performed in a large-volume photoreactor (8000 L) at 294 ± 2 K and atmospheric pressure. The relative kinetic method was used to determine the rate constants for these reactions, with 1,3,5-trimethylbenzene as a reference compound. The rate constants obtained are kOH(m -cresol) = (5.88 ± 0.92) × 10,11 cm3 molecule,1 s,1, kOH(o -cresol) = (4.32 ± 0.52) × 10,11 cm3 molecule,1 s,1, and kOH(p -cresol) = (4.96 ± 0.75) × 10,11 cm3 molecule,1 s,1. The degradation products observed and their respective molar yields were methyl-1,4-benzoquinone 12.4 ± 1.2%, 5-methyl-2-nitrophenol 1.5 ± 0.3%, and 3-methyl-2-nitrophenol 1.4 ± 0.3% from m -cresol, methyl-1,4-benzoquinone 5.6 ± 0.9%, and 6-methyl-2-nitrophenol 4.7 ± 0.8% from o -cresol, and 4-methyl-2-nitrophenol 17.2 ± 2.5% from p -cresol. This kinetic and product data are compared with the literature, and the reaction mechanisms are discussed. Our results are in accordance with the previous studies (Atkinson, J Phys Chem Ref Data 1989, Monograph (1), 1,246; Atkinson and Aschmann, Int J Chem Kinet 1990, 22, 59,67; Atkinson et al., Environ Sci Technol 1992, 26, 1397,1403; Atkinson et al., J Phys Chem 1978, 82, 2759,2805; Olariu et al., Atmos Environ 2002, 36, 3685,3697; Semadeni et al., Int J Chem Kinet 1995, 27, 287,304) and confirm the methyl-1,4-benzoquinone yields determined by a different experimental technique (long-path Fourier transform infrared FT-IR (Olariu et al., 2002)). © 2006 Wiley Periodicals, Inc. Int J Chem Kinet 38: 553,562, 2006 [source]

Next-Generation Architecture to Support Simulation-Based Acquisition

NAVAL ENGINEERS JOURNAL, Issue 4 2000
Dr. B. Chadha
ABSTRACT The ability to make good design decisions early is a significant driver for simulation-based acquisition to effectively lower life-cycle cost and cycle time. Building virtual prototypes, enabling one to analyze the impact of decisions, achieves effective simulation-based acquisition processes. Virtual prototypes need to support a comprehensive set of analyses that will be performed on the product; hence, all aspects of product data and behavior need to be represented. Building virtual prototypes of complex systems being designed by a multi-organizational team requires new architectural concepts and redesigned processes. Implementation of these new architectures is complex and leveraging commercial technologies is necessary to achieve feasible solutions. One must also carefully consider the state of the current commercial technologies and frameworks as well as the organizational and cultural aspects of organizations that use these systems. This paper describes key architectural principles that one must address for a cost-effective implementation. The paper then discusses key architectural concepts and trade-offs that are necessary to support virtual prototypes of complex systems. [source]

Customer-Driven Product Development Through Quality Function Deployment in the U.S. and Japan

THE JOURNAL OF PRODUCT INNOVATION MANAGEMENT, Issue 4 2000
John J. Cristiano
Quality Function Deployment is a tool for bringing the voice of the customer into the product development process from conceptual design through to manufacturing. It begins with a matrix that links customer desires to product engineering requirements, along with competitive benchmarking information, and further matrices can be used to ultimately link this to design of the manufacturing system. Unlike other methods originally developed in the U.S. and transferred to Japan, the QFD methodology was born out of Total Quality Control (TQC) activities in Japan during the 1960s and has been transferred to companies in the U.S. This article reports on the results of a 1995 survey of more than 400 companies in the U.S. and Japan using QFD. The research questions investigated in this study were developed both inductively from QFD case studies in the U.S. and Japan and deductively from the literature. The reported results are in part counterintuitive. The U.S. companies reported a higher degree of usage, management support, cross-functional involvement, use of QFD driven data sources, and perceived benefits from using QFD. For the most part, the main uses of QFD in the U.S. were restricted to the first matrix ("House of Quality") that links customer requirements to product engineering requirements and rarely was this carried forward to later matrices. U.S. companies were more apt to use newly collected customer data sources (e.g., focus groups) and methods for analyzing customer requirements. Japanese companies reported using existing product data (e.g., warranty) and a broader set of matrices to a greater extent. The use of analytical techniques in conjunction with QFD (e.g., simulation, design of experiments, regression, mathematical target setting, and analytic hierarchy process) was not wide spread in either country. U.S. companies were more likely to report benefits of QFD in improving cross-functional integration and better decision-making processes compared to Japanese companies. Possible reasons for these cross-national differences as well as their implications are discussed. [source]

Human Islet Isolation for Autologous Transplantation: Comparison of Yield and Function Using SERVA/Nordmark Versus Roche Enzymes

AMERICAN JOURNAL OF TRANSPLANTATION, Issue 10 2009
T. Anazawa
Islet autotransplantation (IAT) is used to preserve as much insulin-secretory capacity as possible in patients undergoing total pancreatectomy for painful chronic pancreatitis. The enzyme used to dissociate the pancreas is a critical determinant of islet yield, which is correlated with posttransplant function. Here, we present our experience with IAT procedures to compare islet product data using the new enzyme SERVA/Nordmark (SN group; n = 46) with the standard enzyme Liberase-HI (LH group; n = 40). Total islet yields (mean ± standard deviation; 216 417 ± 79 278 islet equivalent [IEQ] in the LH group; 227 958 ± 58 544 IEQ in the SN group; p = 0.67) were similar. However, the percentage of embedded islets is higher in the SN group compared to the LH group. Significant differences were found in pancreas digestion time, dilution time, and digested pancreas weight between the two groups. Multivariate linear regression analysis showed the two groups differed in portal venous pressure changes. The incidence of graft function and insulin independence was not different between the two groups. The SN and LH enzymes are associated with similar outcomes for IAT. Further optimization of the collagenase/neutral protease ratio is necessary to reduce the number of embedded islets obtained when using the SN enzyme. [source]

Import competition and firm refocusing

CANADIAN JOURNAL OF ECONOMICS, Issue 2 2010
Runjuan Liu
Abstract Recent theoretical work predicts a new margin of firm adjustment to trade liberalization; that is, multi-product firms alter their product mix to focus on their core competencies in response to trade liberalization. Using detailed product data from U.S. public firms, I find strong empirical support for this prediction. Specifically, import competition leads multi-product firms to drop peripheral products to refocus on core production. The weaker the linkages that a peripheral product shares with the core (as measured by the extent of joint sales, joint procurement, joint production, and joint sectorship), the more likely the peripheral product is to be divested in response to import competition. Certains travaux théoriques récents prédisent une nouvelle marge d'ajustement de la firme à la libéralisation du commerce : les firmes multi-produits changent leur mix de produits pour se concentrer sur leurs compétences de base en réponse à la libéralisation du commerce. A partir de données détaillées sur les produits de firmes américaines, on découvre que cette prédiction a un fort support empirique. Spécifiquement, la concurrence de l'importation amène la firme multi-produits à laisser tomber des produits périphériques pour recentrer sa production sur son noyau dur de compétences. Plus faibles sont les liens que partage un produit périphérique avec le noyau dur (mesuré par l'étendue des ventes communes, des approvisionnements conjoints, de la production liée, de la participation au même secteur) plus est grande la probabilité qu'on va désinvestir dans ce produit en réponse à la concurrence de l'importation. [source]