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Terms modified by Hot Selected AbstractsCorrosion behaviour of aircraft coating systems in acetate- and formate-based de-icing chemicalsMATERIALS AND CORROSION/WERKSTOFFE UND KORROSION, Issue 3 2009E. Huttunen-Saarivirta Abstract Corrosion behaviour of four coating systems, which are commonly used in aircraft components; namely cadmium-coated and subsequently chromate-treated steel AISI 4340, aluminium-coated steel AISI 4340, anodised aluminium alloy 7075-T6 and chromate-treated aluminium alloy 7075-T6, were investigated in six commercial acetate- and formate-based de-icing chemicals. The results show that the aluminium-coated steel specimens experience least corrosion among the four coating systems; no corrosion is detected in potassium acetate-based de-icing chemicals (Safeway KA HOT, Safegrip and Safegrip+), although some corrosion is observed in the other three chemicals (Safeway SD, Safeway SF and Meltium). In contrast, the coatings in the other three coating systems are damaged in all six de-icing chemicals. The thickness of the coating does not necessarily predict how well the coating will protect the substrate; the thickest coating, several tens of micrometres, is apparent on the cadmium- and chromate-coated steel specimens, while only a few micrometres thin aluminium coating on the steel substrate is the only coating system that can survive the corrosion tests in some of the de-icing chemicals. Comparison of the results from the two test methods used in this research, polarisation measurements and chemical exposure tests, shows that, for each coating system, the extent of corrosion, as evaluated on the basis of weight changes calculated from corrosion current density values and those experienced during chemical exposure tests, is different: the weight changes that materialise during exposure tests are, at least, from one to two orders of magnitude higher than those predicted by calculations. In this paper, these observations are discussed and explanations for them are presented. [source] Consciousness and Higher-Order ThoughtsMIND & LANGUAGE, Issue 3 2001Mark Rowlands This paper argues that higher-order thought (HOT) models of consciousness face serious logical problems. The precise form these problems take varies depending on whether HOT models are understood as attempts to explicate the concept of (intransitive state) consciousness or as attempts to identify the property in virtue of which mental states are (intransitively) conscious. Understood in the former way, HOT models face a problem of circularity. Understood in the latter way, such models face a problem of regress. [source] Neurogastroenterology and Motility goes HOTNEUROGASTROENTEROLOGY & MOTILITY, Issue 2 2003Michael Camilleri No abstract is available for this article. [source] QD technology and market prospects in the sectors of space exploration, biomedicine, defense, and securityPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 12 2008C. A. Charitidis Abstract Quantum dots (QD) are a unique subset of nanomaterials characterized by their extraordinary quantum confinement behaviour. Even though the quantum dot industry is still in its infancy with revenues now reaching $10 million, it is expected to surpass $500 million in 2009. However, in order to leverage the full potential of the QD technology, new fabrication processes must be developed to attain high detectivity and high operating temperature (HOT) photodetector devices. The Quantum Dot Infrared Photodetectors (QDIPs) possess an immense potential for civilian and military applications due to the distinct characteristics stemming from their dimensionality , which provides 3D carrier confinement and the capacity for normal-incidence detection , and their amenability to bandgap engineering , which allows tailoring the peak and cutoff wavelengths according to custom needs. The QDIPs, especially when optimized to operate at higher temperatures, can become critical components in space exploration, defence and security, optical communication, quantum computing and cryptography, and medical imaging applications. Robust and reliable solutions for these fields will command a premium position in the marketplace as by responding to the societal need for secure electronic transactions, exponentially faster data processing, and higher quality diagnostic tools. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Hot and bothered: C-reactive protein, inflammation and atherosclerosisINTERNATIONAL JOURNAL OF CLINICAL PRACTICE, Issue 11 2009A. S. Wierzbicki First page of article [source] Process Optimization and Consumer Acceptability of Salted Ground Beef Patties Cooked and Held Hot in Flavored MarinadeJOURNAL OF FOOD SCIENCE, Issue 7 2010Subash Shrestha Abstract:, Food safety is paramount for cooking hamburger. The center must reach 71 °C (or 68 °C for 15 s) to assure destruction of,E. coli,O157:H7 and other food pathogens. This is difficult to achieve during grilling or frying of thick burgers without overcooking the surface. Thus, the feasibility of partially or completely cooking frozen patties in liquid (93 °C water) together with hot holding in liquid was investigated. Initial studies demonstrated that compared to frying, liquid cooking decreased (P,< 0.05) patty diameter (98 compared with 93 mm) and increased (P,< 0.05) thickness (18.1 compared with 15.6 mm). Liquid cooked patties had greater weight loss (P,< 0.05) immediately after cooking (29 compared with 21%), but reabsorbed moisture and were not different from fried patties after 1 h hot water holding (61 °C). Protein and fat content were not affected by cooking method. However, liquid cooked patties were rated lower (P,< 0.05) than fried patties for appearance (5.7 compared with 7.5) and flavor (5.9 compared with 7.5). An 8-member focus group then evaluated methods to improve both appearance and flavor. Salted, grill-marked patties were preferred, and caramel coloring was needed in the marinade to obtain acceptable flavor and color during liquid cooking or hot holding. Patties with 0.75% salt that were grill-marked and then finish-cooked in hot marinade (0.75% salt, 0.3% caramel color) were rated acceptable (P,< 0.05) by consumers for up to 4 h hot holding in marinade, with mean hedonic panel ratings > 7.0 (like moderately) for appearance, juiciness, flavor, and texture. Practical Application: Grill-marked and marinade-cooked ground beef patties reached a safe internal cooking temperature without overcooking the surface. Burgers cooked using this method maintained high consumer acceptability right after cooking and for up to 4 h of hot holding. Consumers and foodservice operations could use this method without specialized equipment, and instead use inexpensive and common equipment such as a soup pot or a restaurant steam table. Use of marinades (salt/caramel color or others) in this cooking and holding method provides a nearly endless culinary flavoring opportunity. [source] Amplification of Hot DNA segments in Escherichia coliMOLECULAR MICROBIOLOGY, Issue 6 2002Ken-ichi Kodama Summary In Escherichia coli, a replication fork blocking event at a DNA replication terminus (Ter) enhances homologous recombination at the nearby sister chromosomal region, converting the region into a recombination hotspot, Hot, site. Using a RNaseH negative (rnhA,) mutant, we identified eight kinds of Hot DNAs (HotA,H). Among these, enhanced recombination of three kinds of Hot DNAs (HotA,C) was dependent on fork blocking events at Ter sites. In the present study, we examined whether HotA DNAs are amplified when circular DNA (HotA plus a drug-resistance DNA) is inserted into the homologous region on the chromosome of a rnhA, mutant. The resulting HotA DNA transformants were analysed using pulsed-field gel electrophoresis, fluorescence in situ hybridization and DNA microarray technique. The following results were obtained: (i) HotA DNA is amplified by about 40-fold on average; (ii) whereas 90% of the cells contain about 6,10 copies of HotA DNA, the remaining 10% of cells have as many as several hundred HotA copies; and (iii) amplification is detected in all other Hot DNAs, among which HotB and HotG DNAs are amplified to the same level as HotA. Furthermore, HotL DNA, which is activated by blocking the clockwise oriC -starting replication fork at the artificially inserted TerL site in the fork-blocked strain with a rnhA+ background, is also amplified, but is not amplified in the non-blocked strain. From these data, we propose a model that can explain production of three distinct forms of Hot DNA molecules by the following three recombination pathways: (i) unequal intersister recombination; (ii) intrasister recombination, followed by rolling-circle replication; and (iii) intrasister recombination, producing circular DNA molecules. [source] Hot and cold gas accretion and feedback in radio-loud active galaxiesMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 4 2007M. J. Hardcastle ABSTRACT We have recently shown that X-ray observations of the population of ,low-excitation' radio galaxies, which includes most low-power, Fanaroff,Riley class I sources as well as some more powerful Fanaroff,Riley class II objects, are consistent with a model in which the active nuclei of these objects are not radiatively efficient at any waveband. In another recent paper, Allen et al. have shown that Bondi accretion of the hot, X-ray emitting phase of the intergalactic medium (IGM) is sufficient to power the jets of several nearby, low-power radio galaxies at the centres of clusters. In this paper, we combine these ideas and suggest that accretion of the hot phase of the IGM is sufficient to power all low-excitation radio sources, while high-excitation sources are powered by accretion of cold gas that is in general unrelated to the hot IGM. This model explains a number of properties of the radio-loud active galaxy population, and has important implications for the energy input of radio-loud active galactic nuclei into the hot phase of the IGM: the energy supply of powerful high-excitation sources does not have a direct connection to the hot phase. [source] In vitro adhesion of Candida species to denture base materialsMYCOSES, Issue 2 2006X. Y. He Summary Adhesion of Candida species to prosthetic acrylic resins is an essential first step in the pathogenesis of denture stomatitis. Data on the relative adhesion of pathogenic non- albicans Candida species to different denture base materials are sparse. The purpose of the present study was to investigate in vitro adhesion of C. albicans, C. glabrata, C. krusei and C. dubliniensis to four different denture base materials. Specimens of both heat-cured resins (VertexTM Rapid Simplified and ProBaseTM Hot) and cold-cured resins (Paladur® A and Paladur® B) were prepared using a novel method and the adhesion of four strains each of the foregoing Candida species evaluated microscopically using a soft imaging system. There was a significant difference in yeast adherence between Vertex and the other resins. Only C. glabrata attached to Vertex, while all the remainder of the tested species adhered to all other resins tested except ProBase, which resisted C. krusei adhesion. There was a significant difference in candidal adhesion between cold-cured and heat-cured resins for three Candida species (C. albicans, P = 0.039; C. glabrata, P = 0.002 and C. krusei, P = 0.000). The type of denture base material and whether they are heat-cured or cold-cured play an important role in modifying candidal adhesion. [source] Some Like It Hot: Teaching Strategies for Managing Tactical Versus Genuine Anger in NegotiationsNEGOTIATION AND CONFLICT MANAGEMENT RESEARCH, Issue 4 2008Holly A. Schroth Abstract A critically important skill in any negotiation is the ability to manage the emotions that are inevitably evoked by conflict. Anger is one of the most widely studied emotions that occur in negotiation. The purpose of this article is to introduce strategies for managing tactical and genuine anger in negotiations. The difference between tactical and genuine anger is discussed along with different strategies for managing each of these types of anger. The article concludes with advice for instructors to help negotiation students acquire experience in managing both their own and the other party's anger. [source] "Hot" Surface Activation of Molecular Complexes: Insight from Modeling Studies,ANGEWANDTE CHEMIE, Issue 11 2010Ettore Fois Prof. Tanz auf dem Vulkan: Das Modellieren der ersten Aktivierungsstufen eines Cu-Komplexes (siehe Bild; Cu gelb, O rot, N blau, F grün, C grau, H weiß, Si schwarz) auf einer beheizten Oberfläche (750,K) enthüllte zwei Bewegungsarten: eine langsame Diffusion durch ,Anstoßen und Taumeln" und eine schnelle Rollbewegung, die mit deutlichen temperaturinduzierten Bindungsoszillationen einhergeht. Diese Befunde geben einen Einblick in die Prozesse bei der Aktivierung durch ,heiße" Oberflächen. [source] "Drinking the Hot Blood of Humans": Witchcraft Confessions in a South African Pentecostal ChurchANTHROPOLOGY & HUMANISM, Issue 1 2003Jennifer BadstuebnerArticle first published online: 28 JUN 200 Giant cats flying to America and cities under the sea off Cape Town are part of a cascade of imagery brought forth in the confessions ofbom-again witches. Now Christian, these exwitches confess stories of murder and bloodshed to packed audiences in townships in the Eastern and Western Cape provinces of South Africa. The confessions reveal occult realms in deep engagement with the particular experiences of young, poor, black women in South Africa. These confessions are performances of risky agency in a country in which acts of witchcraft are severely punished. This article explores the possible motivations of these young, disenfranchised women who take up witchcraft and Christianity as one way to negotiate conditions of extreme violence and dislocation in the sprawling urban townships. [source] Hot and cold technologies for tissue ablation in urologyBJU INTERNATIONAL, Issue 6 2006Jennifer M. Burr Increasingly, technology plays an important role in urology, and with this greater use comes the expected increase in regulation. Authors from the UK present a review of the physical properties of ablative technologies, evaluating efficacy and safety, and summarising guidance issued by the National Institute of Health and Clinical Excellence (NICE) where available. There are also reviews from the UK on haematuria, and on the pathology of bladder cancer from an international group of European authors. [source] The differences in human cumulative irritation responses to positive and negative irritant controls from three geographical locationsINTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Issue 5 2008Mingyi W. Trimble A retrospective analysis was conducted to evaluate whether studies from three geographically diverse locations have similar response profiles to the positive and negative controls in a standard 14-day cumulative irritation study. The positive irritant control (0.1% sodium lauryl sulphate) and the negative control (0.9% sodium chloride, saline) data from seventeen 14-day cumulative irritation studies were reviewed. The studies were compiled from three locations representing dry/hot, humid/hot, and dry/cold environments (Scottsdale, Arizona; St Petersburg, Florida; and Winnipeg, Manitoba, respectively). Irritation scores were generated by trained skin graders from a total of 442 subjects studied between 1999 and 2005. Cumulative irritation scores were reviewed and compared between study locations. The irritation scores for the positive and negative controls were not significantly different between locations. Temperature and relative humidity variation did not correlate significantly with overall irritation. However, the dryer climate (i.e. negative or low dew point) had a tendency to induce a higher overall irritation level for both positive and negative controls. [source] Sheath in Front of a Negatively Biased Collector that Emits Electrons and is Immersed in a Two Electron Temperature PlasmaCONTRIBUTIONS TO PLASMA PHYSICS, Issue 8 2005T. Gyergyek Abstract An extension of a recently published [Gyergyek T., ,er,ek M. Contrib. Plasma Phys., 45, (2005), 89] one dimensional fluid model of the sheath formation in front of a floating electrode (collector) that emits secondary electrons and is immersed in a two-electron temperature nonmagnetized, collisionless plasma is presented. The electron velocity distribution function is assumed to be a two-temperature maxwellian, while the singly charged positive ions and the emitted electrons are assumed to be monoenergetic. It is assumed that the electrons in the pre-sheath potential drop obey the Boltzmann relation, so that a larger fraction of the hot than of the cool electrons can penetrate to the sheath edge. Our model predicts that the collector can in some cases have 3 and in some cases, when the emission of electrons from the collector is critical, even 5 different floating potentials at the same hot to cool electron temperature and density ratios very far away from the collector. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Fluid Model of a Sheath Formed in Front of an Electron Emitting Electrode Immersed in a Plasma with Two Electron TemperaturesCONTRIBUTIONS TO PLASMA PHYSICS, Issue 2 2005T. Gyergyek Abstract The formation of a sheath in front of a negatively biased electrode (collector) that emits electrons is studied by a one-dimensional fluid model. Electron and ion emission coefficients are introduced in the model. It is assumed that the electrode is immersed in a plasma that contains energetic electrons. The electron velocity distribution function is assumed to be a sum of two Maxwellian distributions with two different temperatures, while the ions and the emitted electrons are assumed to be monoenergetic. The condition for zero electric field at the collector is derived. Using this equation the dependence of electron and ion critical emission coefficients on various parameters - like the ratio between the hot and cool electron density, the ratio between hot and cool electron temperature and the initial velocity of secondary electrons - is calculated for a floating collector. A modification of the Bohm criterion due to the presence of hot and emitted electrons is also given. The transition between space charge limited and temperature limited electron emission for a current-carrying collector is also analyzed. The critical potential, where this transition occurs, is calculated as a function of several parameters like the Richardson emission current, the ratio between the hot and cool electron density, the ratio between hot and cool electron temperature and the initial velocity of secondary electrons. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] The fundamental and realized niche of the Monterey Pine aphid, Essigella californica (Essig) (Hemiptera: Aphididae): implications for managing softwood plantations in AustraliaDIVERSITY AND DISTRIBUTIONS, Issue 4 2004Trudi N. Wharton ABSTRACT Essigella californica is a pine aphid native to western North America. In Australia, E. californica is considered an invasive pest that has the potential to cause severe economic loss to the Australian forestry industry. Two CLIMEX models were developed to predict the Australian and global distribution of E. californica under current climate conditions based upon the aphid's known North American distribution. The first model (model I) was fitted using the reasonably contiguous set of location records in North America that constituted the known range of E. californica, and excluded consideration of a single (reliable) location record of the aphid in southern Florida. The second model (model II) was fitted using all known records in North America. Model I indicated that the aphid would be climatically restricted to the temperate, Mediterranean and subtropical climatic regions of Australia. In northern Australia it would be limited by hot, wet conditions, while in more central areas of Australia it is limited by hot, dry conditions. Model II is more consistent with the current Australian distribution of E. californica. The contrast in geographical range and climatic conditions encompassed between the two models appears to represent the difference between the realized niche (model I) and fundamental niche (model II) of E. californica. The difference may represent the strength of biotic factors such as host limitation, competition and parasitism in limiting geographical spread in the native range. This paper provides a risk map for E. californica colonization in Australia and globally. E. californica is likely to remain a feature of the Australian pine plantations, and any feasibility studies into establishing coniferous plantations in lower rainfall areas should consider the likely impact of E. californica. [source] Heat or Cold Packs for Neck and Back Strain: A Randomized Controlled Trial of EfficacyACADEMIC EMERGENCY MEDICINE, Issue 5 2010Gregory Garra DO Abstract Objectives:, Acute back and neck strains are very common. In addition to administering analgesics, these strains are often treated with either heat or cold packs. The objective of this study was to compare the analgesic efficacy of heat and cold in relieving pain from back and neck strains. The authors hypothesized that pain relief would not differ between hot and cold packs. Methods:, This was a randomized, controlled trial conducted at a university-based emergency department (ED) with an annual census of 90,000 visits. ED patients >18 years old with acute back or neck strains were eligible for inclusion. All patients received 400 mg of ibuprofen orally and then were randomized to 30 minutes of heating pad or cold pack applied to the strained area. Outcomes of interest were pain severity before and after pack application on a validated 100-mm visual analog scale (VAS) from 0 (no pain) to 100 (worst pain), percentage of patients requiring rescue analgesia, subjective report of pain relief on a verbal rating scale (VRS), and future desire for similar packs. Outcomes were compared with t-tests and chi-square tests. A sample of 60 patients had 80% power to detect a 15-mm difference in pain scores. Results:, Sixty patients were randomized to heat (n = 31) or cold (n = 29) therapy. Mean (±standard deviation [SD]) age was 37.8 (±14.7) years, 51.6% were female, and 66.7% were white. Groups were similar in baseline patient and pain characteristics. There were no differences between the heat and cold groups in the severity of pain before (75 mm [95% CI = 66 to 83] vs. 72 mm [95% CI = 65 to 78]; p = 0.56) or after (66 mm [95% CI = 57 to 75] vs. 64 mm [95% CI = 56 to 73]; p = 0.75) therapy. Pain was rated better or much better in 16/31 (51.6%) and 18/29 (62.1%) patients in the heat and cold groups, respectively (p = 0.27). There were no between-group differences in the desire for and administration of additional analgesia. Twenty-five of 31 (80.6%) patients in the heat group and 22 of 29 (75.9%) patients in the cold group would use the same therapy if injured in the future (p = 0.65). Conclusions:, The addition of a 30-minute topical application of a heating pad or cold pack to ibuprofen therapy for the treatment of acute neck or back strain results in a mild yet similar improvement in the pain severity. However, it is possible that pain relief is mainly the result of ibuprofen therapy. Choice of heat or cold therapy should be based on patient and practitioner preferences and availability. ACADEMIC EMERGENCY MEDICINE 2010; 17:484,489 © 2010 by the Society for Academic Emergency Medicine [source] HR shared services is hot and getting hotterEMPLOYMENT RELATIONS TODAY, Issue 2 2010Jim Scully First page of article [source] Hypolithic community shifts occur as a result of liquid water availability along environmental gradients in China's hot and cold hyperarid desertsENVIRONMENTAL MICROBIOLOGY, Issue 2 2007Stephen B. Pointing Summary Hypolithic cyanobacterial communities occur in hot and cold hyperarid environments but the physical factors determining their diversity are not well understood. Here we report hypolithic diversity and colonization of a common quartz substrate at several hyperarid locations in the ancient deserts of north-western China, that experience varying mean annual temperature, rainfall and concomitant availability of liquid water in soil. Microscopy and enrichment culture resulted only in Chroococcidiopsis morphotypes which were ubiquitous, but community phylogenetic analysis revealed considerable cyanobacterial and heterotrophic bacterial diversity. Species Richness and Shannon's Diversity Index displayed a significant positive linear correlation with availability of liquid water but not temperature or rainfall alone. Several taxonomic groups occurred only in specific climatically defined locations, while for Chroococcidiopsis, Deinococcus and Phormidium location specific lineages within these genera were also evident. Multivariate analysis was used to illustrate pronounced community shifts due to liquid water availability, although these did not significantly affect the predicted functional relationships within any given assemblage in either hot or cold, wet or dry hyperarid deserts. This study clearly demonstrates that availability of liquid water, rather than temperature or rainfall per se is the key determinant of hypolithic diversity in hyperarid locations, and furthermore that functionally similar yet taxonomically distinct communities occur, characterized by the presence of taxa that are specific to defined levels of aridity. [source] Treatment of PCB-contaminated soils: I. Evaluation of in situ reductive dechlorination of PCBsENVIRONMENTAL PROGRESS & SUSTAINABLE ENERGY, Issue 2 2001Robert C. Ahlert PhD PE Soil samples were obtained from a site contaminated with PCBs. PCB contamination is not uniform at the source of the samples. Some may be present as isolated "hot spots." The anaerobic phase of a two-stage bioremediation process was evaluated. Populations of native organisms were very low. Species capable of dechlorination of PCBs did not proliferate under anaerobic conditions in the laboratory. Reductive dechlorination did not occur. In-situ reductive dechlorination of heavily substituted PCB congeners is not likely to make a useful contribution to elimination at the site represented by the soil samples. [source] Comparison of Isoelectronic Heterometallic and Homometallic Binuclear Cyclopentadienylmetal Carbonyls: The Iron,Nickel vs. the Dicobalt SystemsEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 8 2008Jun D. Zhang Abstract The heterometallic binuclear cyclopentadienylironnickel carbonyl compounds Cp2FeNi(CO)n (n = 3, 2, 1; Cp = ,5 -C5H5) have been studied by density functional theory (BP86) for comparison with the isoelectronic homometallic dicobalt derivatives Cp2Co2(CO)n. The FeNi tricarbonyl is shown to be the doubly bridged isomer Cp2Fe(CO)Ni(,-CO)2 with an Fe,Ni distance of 2.455 Å (BP86), in accord with experiment and in contrast to Cp2Co2(CO)3 where singly and triply bridged but not doubly bridged isomers are found. The dicarbonyl compounds Cp2FeNi(,-CO)2 and Cp2Co2(,-CO)2 both have analogous doubly bridged structures with M=M distances around 2.35 Å, suggesting formal M=M double bonds. The monocarbonyl compounds have analogous singly bridged axial structures Cp2FeNi(,-CO) and Cp2Co2(,-CO) with metal,metal distances in the range 2.05 Å (M2 = Co2) to 2.12 Å (M2 = FeNi) consistent with the formal M,M triple bonds required for the favored 18-electron configuration. Open-shell states of Cp2FeNi(,-CO) are found to have even lower energies than the closed-shell structure, which indicates that the ground state of Cp2FeNi(,-CO) might be a high spin structure. However, the global minimum for the monocarbonyl is found to be a singlet "hot dog" perpendicular Cp2NiFe(CO) structure with a terminal CO group bonded to the iron atom. Other higher energy perpendicular structures are also found for Cp2FeNi(CO)n (n = 3, 2, 1) with terminal CO groups and bridging Cp rings. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source] Seed roasting improves the oxidative stability of canola (B.,napus) and mustard (B.,juncea) seed oilsEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 4 2008Chakra Wijesundera Abstract Animal fats and partially hydrogenated vegetable oils (PHVO) have preferentially been used for deep-frying of food because of their relatively high oxidative stability compared to natural vegetable oils. However, animal fats and PHVO are abundant sources of saturated fatty acids and trans fatty acids, respectively, both of which are detrimental to human health. Canola (Brassica napus) is the primary oilseed crop currently grown in Australia. Canola quality Indian mustard (Brassica juncea) is also being developed for cultivation in hot and low-rainfall areas of the country where canola does not perform well. A major impediment to using these oils for deep-frying is their relatively high susceptibility to oxidation, and so any processing interventions that would improve the oxidative stability would increase their prospects of use in commercial deep-frying. The oxidative stability of both B.,napus and B.,juncea crude oils can be improved dramatically by roasting the seeds (165,°C, 5,min) prior to oil extraction. Roasting did not alter the fatty acid composition or the tocopherol content of the oils. The enhanced oxidative stability of the oil, solvent-extracted from roasted seeds, is probably due to 2,6-dimethoxy-4-vinylphenol produced by thermal decarboxylation of the sinapic acid naturally occurring in the canola seed. [source] Crack Propagation in Tool Steel X38CrMoV5 (AISI H11) in SET Specimens,ADVANCED ENGINEERING MATERIALS, Issue 9 2009Masood Shah An approach is proposed for the evaluation of surface fatigue damage of hot forming tools that undergo severe thermo mechanical loading. Fatigue crack propagation in a hot work tool steel X38CrMoV5-47HRC is investigated using single-edge cracked tension specimens with 3 different thicknesses (2.5, 1, 0.6,mm) and two R-values. [source] Microstructure Characterization of Tool Steel Claddings Co-Extruded on Low Alloyed Steel Substrates,ADVANCED ENGINEERING MATERIALS, Issue 5 2009Pedro Augusto da Souza e Silva Low-alloyed steel bars are hot extruded with pre-sintered tool-steel powders with or without the addition of tungsten carbides (W2C/WC) as hard particles. An extrudate is formed consisting of a wear resistant coating layer and a bulk steel bar as the substrate core. The microstructure at the interface between coating and substrate of different coatings is characterized using OM, SEM and EBSD. [source] Hot Workability, Microstructural Control and Rate-Controlling Mechanisms in Cast-Homogenized AZ31 Magnesium Alloy,ADVANCED ENGINEERING MATERIALS, Issue 3 2009Yellapregada Venkata Rama Krishna Prasad Optimum conditions for microstructural control in industrial hot working of cast and homogenized AZ31 magnesium alloys are evaluated by using a processing map. The recommended window for bulk metal working of this alloy is the domain in the temperature range 300,450,°C and strain rate range 1,10,s,1, and the optimum processing parameters are 400,°C and 10,s,1, where grain-boundary self diffusion is the rate-controlling mechanism. [source] BURNING PHYLOGENIES: FIRE, MOLECULAR EVOLUTIONARY RATES, AND DIVERSIFICATIONEVOLUTION, Issue 9 2007Miguel Verdú Mediterranean-type ecosystems are among the most remarkable plant biodiversity "hot spots" on the earth, and fire has traditionally been invoked as one of the evolutionary forces explaining this exceptional diversity. In these ecosystems, adult plants of some species are able to survive after fire (resprouters), whereas in other species fire kills the adults and populations are only maintained by an effective post-fire recruitment (seeders). Seeders tend to have shorter generation times than resprouters, particularly under short fire return intervals, thus potentially increasing their molecular evolutionary rates and, ultimately, their diversification. We explored whether seeder lineages actually have higher rates of molecular evolution and diversification than resprouters. Molecular evolutionary rates in different DNA regions were compared in 45 phylogenetically paired congeneric taxa from fire-prone Mediterranean-type ecosystems with contrasting seeder and resprouter life histories. Differential diversification was analyzed with both topological and chronological approaches in five genera (Banksia, Daviesia, Lachnaea, Leucadendron, and Thamnochortus) from two fire-prone regions (Australia and South Africa). We found that seeders had neither higher molecular rates nor higher diversification than resprouters. Such lack of differences in molecular rates between seeders and resprouters,which did not agree with theoretical predictions,may occur if (1) the timing of the switch from seeding to resprouting (or vice versa) occurs near the branch tip, so that most of the branch length evolves under the opposite life-history form; (2) resprouters suffer more somatic mutations and therefore counterbalancing the replication-induced mutations of seeders; and (3) the rate of mutations is not related to shorter generation times because plants do not undergo determinate germ-line replication. The absence of differential diversification is to be expected if seeders and resprouters do not differ from each other in their molecular evolutionary rate, which is the fuel for speciation. Although other factors such as the formation of isolated populations may trigger diversification, we can conclude that fire acting as a throttle for diversification is by no means the rule in fire-prone ecosystems [source] The Effect of Compaction Method on the Expansion and Stability of Aluminium Foams,ADVANCED ENGINEERING MATERIALS, Issue 9 2006S. Asavavisithchai Abstract The foam expansion and collapse behaviour for heat treated Al-TiH2 precursors has been shown to be driven by the oxidation of the Al powder, which can, in moderation, improve the foam expansion and increase foam stability, and the premature loss of gas from the TiH2, which delays but decreases the foam expansion. The evidence presented indicates that as long as theoretical precursor densities >,99,% can be achieved, simultaneous heating and compaction are not required to achieve the best foaming behaviour. Instead, the oxygen or oxide content in the powder is critical and if the oxygen content in the atomised powder is in the range 0.3,0.4,wt.%, cold compaction is sufficient to produce foams which show expansions at least as good as those for precursors made by high cost hot working processes. [source] Fatigue behaviour of duplex stainless steel reinforcing bars subjected to shot peeningFATIGUE & FRACTURE OF ENGINEERING MATERIALS AND STRUCTURES, Issue 7 2009E. REAL ABSTRACT The influence of shot peening on the fatigue properties of duplex stainless steel reinforcing bars manufactured using both hot- and cold-rolled processes was studied. The S-N curves of the bars before and after the shot-peening process were determined, showing that shot peening improves the fatigue behaviour of the rebars. This improvement is essentially due to the introduction of a compressive residual stress field in the surface of the reinforcing bars, but also to the smoothing of the surface flaws and cold working generated during the manufacturing process. This improvement is much greater in the case of the hot-rolled bars, mainly as a result of their much higher ability for plastic deformation, whereas cold-rolled bars had a much higher hardness. A more severe peening action capable of promoting greater plastic deformation on the bar surface is judged necessary to improve the fatigue resistance of cold-rolled rebars. [source] Behavioural responses of a south-east Australian floodplain fish community to gradual hypoxiaFRESHWATER BIOLOGY, Issue 3 2007DALE G. MCNEIL Summary 1. Hypoxic conditions occur frequently during hot, dry summers in the small lentic waterbodies (billabongs) that occur on the floodplains of the Murray-Darling River system of Australia. Behavioural responses to progressive hypoxia were examined for the native and introduced floodplain fish of the Ovens River, an unregulated tributary of the Murray River in south-east Australia. 2. Given the high frequency of hypoxic episodes in billabongs on the Ovens River floodplain, it was hypothesised that all species would exhibit behaviours that would confer a degree of hypoxia-tolerance. Specifically, it was hypothesised that as hypoxia progressed, gill ventilation rates (GVRs) would increase and aquatic surface respiration (ASR) would become increasingly frequent. Fish were subjected to rapid, progressive hypoxia from normoxia to anoxia in open tanks. 3. All tested species exhibited behaviours consistent with their use of potentially hypoxic habitats. As hypoxia progressed, GVRs increased and all species, with the exception of oriental weatherloach, began to switch increasingly to ASR with 90% of individuals using ASR at various oxygen concentrations below 1.0 mg O2 L,1. Australian smelt, redfin perch and flat-headed galaxias were the first three species to rise to ASR, with 10% of individuals using ASR by 2.55, 2.29 and 2.21 mg O2 L,1 respectively. Goldfish and common carp were the last two species to rise to ASR, with 10% of individuals using ASR by 0.84 and 0.75 mg O2 L,1 respectively. In contrast to other species, oriental weatherloach largely ceased gill ventilation and used air-gulping as their primary means of respiration during severe hypoxia and anoxia. 4. Australian smelt, redfin perch and flat-headed galaxias were unable to maintain ASR under severe hypoxia, and began exhibiting erratic movements, termed terminal avoidance behaviour, and loss of equilibrium. All other species continued to use ASR through severe hypoxia and into anoxia. Following a rise to ASR, GVRs either remained steady or decreased slightly indicating partial or significant relief from hypoxic stress for these hypoxia-tolerant species. 5. Behavioural responses to progressive hypoxia amongst the fish species of the Ovens River floodplain indicate a generally high level of tolerance to periodic hypoxia. However, species-specific variation in hypoxia-tolerance may have implications for community structure of billabong fish communities following hypoxic events. [source] | ||||||||||||||||||||||||||||||||||||||||||||||