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21.
For a highly exothermic reaction, heat capacity is a critical determinant of temperature profile which impacts temperature-dependent variables such as reaction rate constants, heat of reaction, viscosity, and diffusivity. In the case of polymer-forming reactions: literally hundreds of oligomers can be present at any time, heat capacities are typically not available for most of these oligomeric monomers. The group contribution method emerges as one of the few viable approaches to make an estimate of heat capacities being a salient intermediate step toward the objective of simulating polyurethane reaction process. Based on compiled literature and supplemental DSC data, Missernard’s group contribution model was revised with alternative values to those suggested by literature and accessorial parameters for the following functional groups: a) isocyanate, b) six carbon sugar ring, c) aromatic benzene ring, and d) double-bonded oxygen of an ester to estimate heat capacities from 25 °C to 120 °C for alcohols and isocyanate present in the urethane-forming reactions. Modeling performance showed a good agreement with an overall 1.59 per cent deviation. It was also observed that the alcohol heat capacity generally decreased with the rise of molecular weight. 相似文献
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Pickard G Pan W Rahwan I Cebrian M Crane R Madan A Pentland A 《Science (New York, N.Y.)》2011,334(6055):509-512
The World Wide Web is commonly seen as a platform that can harness the collective abilities of large numbers of people to accomplish tasks with unprecedented speed, accuracy, and scale. To explore the Web's ability for social mobilization, the Defense Advanced Research Projects Agency (DARPA) held the DARPA Network Challenge, in which competing teams were asked to locate 10 red weather balloons placed at locations around the continental United States. Using a recursive incentive mechanism that both spread information about the task and incentivized individuals to act, our team was able to find all 10 balloons in less than 9 hours, thus winning the Challenge. We analyzed the theoretical and practical properties of this mechanism and compared it with other approaches. 相似文献
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20世纪50年代初期,膨化熟化工艺首次应用于干膨化宠物料生产。发展到现在,干膨化宠物料在市场中占有明显的统治地位,而软膨化食品成为当今宠物料市场最时尚且最具创新的产品之一。所有的这些进步,无疑都得益于技术的革新,这不论是对设备选择还是加工工艺都同样重要。在"宠物料"的中篇(20期)中,Galen Rokey先生就原料的选择对产品的影响以及膨化过程中存在的变量做了介绍。本期,他将对宠物料的质量控制和营运成本做进一步的说明。 相似文献
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Gaby Van Galen DVM MSc DECEIM Helene Amory DVM PhD DECEIM Evita Busschers DVM DACVS Dominique Cassart DVM PhD Marco De Bruijn DVM DECEIM Vincent Gerber DVM PhD DECEIM John Keen DVM MSc DECEIM Laurence Lefere DVM Christel Marcillaud Pitel DVM Celia Marr DVM PhD DECEIM Jessica‐M. V. Müller DVM DECEIM Xavier Pineau DVM Claude Saegerman PhD Charlotte Sandersen DVM PhD DECEIM Didier Serteyn DVM PhD DECVAA Sara Torfs DVM Lucia Unger DVM Denis Verwilghen DVM MSc DECVS Dominique‐Marie Votion DVM PhD 《Journal of Veterinary Emergency and Critical Care》2010,20(5):528-532
Background – Atypical myopathy is an acute, severe rhabdomyolysis occurring in grazing horses. In the beginning of October 2009, a new outbreak occurred in several European countries. Geographic, demographic and clinical data of the reported cases in the month October 2009 are described. Key Findings – The survival rate in this outbreak was 25%. The most frequently observed clinical signs were congested mucous membranes, dyspnea, tachycardia, depression, weakness, stiffness, recumbency, trembling, sweating, and myoglobinuria. Nonsurvivors were significantly more likely to be recumbent than survivors. Prognostic factors, symptomatic treatment, and preventive measures are discussed. Significance – Differences were encountered during the described outbreak of atypical myopathy in October 2009 compared with previous outbreaks reported. Equine practitioners should be aware that previous epidemiological studies have shown that after a high prevalence in the autumn, new cases are likely to occur in the following spring. 相似文献
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Lauren R Wottlin Gordon E Carstens William C Kayser William E Pinchak Jennifer M Thomson Valerie Copi Galen P O&#x;Shea-Stone 《Journal of animal science》2021,99(1)
Indicator traits associated with disease resiliency would be useful to improve the health and welfare of feedlot cattle. A post hoc analysis of data collected previously (Kayser et al., 2019a) was conducted to investigate differences in immunologic, physiologic, and behavioral responses of steers (N = 36, initial BW = 386 ± 24 kg) that had differential haptoglobin (HPT) responses to an experimentally induced challenge with Mannheimia haemolytica (MH). Rumen temperature, DMI, and feeding behavior data were collected continuously, and serial blood samples were collected following the MH challenge. Retrospectively, it was determined that 9 of the 18 MH-challenged steers mounted a minimal HPT response, despite having similar leukocyte and temperature responses to other MH-challenged steers with a greater HPT response. Our objective was to examine differences in behavioral and physiological responses between MH-challenged HPT responsive (RES; n = 9), MH-challenged HPT nonresponsive (NON; n = 9), and phosphate-buffered saline-inoculated controls (CON; n = 18). Additionally, 1H NMR analysis was conducted to determine whether the HPT-responsive phenotype affected serum metabolite profiles. The RES steers had lesser (P < 0.05) cortisol concentrations than NON and CON steers. The magnitude of the increases in neutrophil concentrations and rumen temperature, and the reduction in DMI following the MH challenge were greatest (P < 0.05) in RES steers. Univariate analysis of serum metabolites indicated differences between RES, NON, and CON steers following the MH challenge; however, multivariate analysis revealed no difference between HPT-responsive phenotypes. Prior to the MH challenge, RES steers had longer (P < 0.05) head down and bunk visit durations, slower eating rates (P < 0.01) and greater (P < 0.05) daily variances in bunk visit frequency and head down duration compared with NON steers, suggesting that feeding behavior patterns were associated with the HPT-responsive phenotype. During the 28-d postchallenge period, RES steers had decreased (P < 0.05) final BW, tended (P = 0.06) to have lesser DMI, and had greater (P < 0.05) daily variances in head down and bunk visit durations compared with NON steers, which may have been attributed to their greater acute-phase protein response to the MH challenge. These results indicate that the HPT-responsive phenotype affected feeding behavior patterns and may be associated with disease resiliency in beef cattle. 相似文献
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Pim-pahn Kiatsimkul Galen J. Suppes Fu-hung Hsieh Zuleica Lozada Yuan-Chan Tu 《Industrial Crops and Products》2008,27(3):257-264
Multiple novel vegetable oil-based polyols were synthesized from the reaction-addition to epoxidized soybean oil (ESBO) by a series of acid acyl moieties derived from vegetable oils. The acid acyl moieties were linoleic acid (LA), ricinoleic acid (RC), ricinoleic acid estolide (RC estolide) and hydrolyzed bodied soybean oil (HBSBO). LA and RC were commercially available but RC estolide and HBSBO were synthesized by enzymatic catalytic reactions. In the reaction-addition, ESBO was heated with the acid acyl moieties at 170 °C, atmospheric pressure without any catalyst and solvent. The synthesized vegetable oil-based polyols had acid numbers less than 10 (mg KOH/g), hydroxy numbers of 82–152 (mg KOH/g), and hydroxyl equivalent weights of 370–680. The polyols made from RC estolide and HBSBO had improved numbers of OH equivalent weight comparing to the numbers from alkoxyl hydroxyl soybean oil which is widely used commercial soy-based polyols. 相似文献
28.
D. R. Verwilghen L. Vanderheyden T. Franck V. Busoni E. Enzerink M. Gangl J.-P. Lejeune G. van Galen S. Grulke D. Serteyn 《Veterinary research communications》2009,33(7):701-709
Developmental osteochondral lesions are often encountered in the equine population and are a major cause of lameness. Different
growth factors that act systemically as well as locally regulate the growth of cartilage. Among them is Insulin-like Growth
Factor I that has been demonstrated to promote chondrocyte growth and differentiation and that has been shown to influence
cartilage repair. The aims of this study were to investigate differences in circulating plasma levels of Insulin-like Growth
Factor-I in post-pubescent horses affected with developmental osteochondral lesions compared to unaffected ones. Significantly
higher values of circulating Insulin-like Growth Factor-I levels were found in the affected group (n = 82) compared to controls
(n = 86). This result may still reflect an earlier imbalance in IGF-I levels from horses with developmental osteochondral
lesions considering the aetiopathological link which has been made between IGF-I and the occurrence of osteochondrosis. However,
other studies have shown increased expression of IGF-I after cartilage damage. The higher levels found in this study could
be due to a healing response of the cartilage to the damage caused by the osteochondral lesions. 相似文献
29.
Votion DM Linden A Delguste C Amory H Thiry E Engels P van Galen G Navet R Sluse F Serteyn D Saegerman C 《Veterinary journal (London, England : 1997)》2009,180(1):77-87
Over the last decade, atypical myopathy (AM) in grazing horses has emerged in several European countries. An exploratory analysis was conducted to determine horse- and pasture-level indicators or factors associated with AM in Belgium. Belgian cases of AM confirmed by histology (n=57) were compared to their healthy co-grazing horses (n=77) and to pastured horses not involved with AM as controls (n=386). The pastures where confirmed cases were grazing (42 pastures; 38 sites; 44 incidences of AM) were compared with those of the controls (216 pastures; 96 sites; no incidence of AM). Statistically significant (P< or =0.05) exploratory variables, identified by means of adjusted odds ratios, suggested that indicators or factors associated with individual horses (young age, inactivity, body condition poor to normal), management practices (permanent pasturing, spreading of manure) and pasture characteristics (humid, sloping pastures, accumulated dead leaves, presence of waterway) may increase the risk of AM. Specific interventions based on these factors might help to reduce the incidence of AM. 相似文献