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Humid Environment (humid + environment)
Selected AbstractsCommunity-acquired methicillin-resistant Staphylococcus aureus skin infections: a review of epidemiology, clinical features, management, and preventionINTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 1 2007Philip R. Cohen MD Community-acquired methicillin-resistant Staphylococcus aureus (CAMRSA) infection is a global problem of epidemic proportions. Many of the patients who develop CAMRSA skin lesions do not have infection-associated risk factors. Abscess, abscess with accompanying cellulitis, and cellulitis are the most common presentations of cutaneous CAMRSA infection; occasionally, these CARMSA-related lesions are misinterpreted as spider or insect bites. Other manifestations of cutaneous CAMRSA infection include impetigo, folliculitis, and acute paronychia. The management of CAMRSA skin infection includes incision and drainage, systemic antimicrobial therapy, and adjuvant topical antibacterial treatment. In addition, at the initial visit, bacterial culture of the lesion should be considered. Direct skin-to-skin contact, damage to the skin surface, sharing of personal items, and a humid environment are potential mechanisms for the acquisition and transmission of cutaneous CAMRSA infection. Measures that strive to eliminate these causes are useful for preventing the spread of CAMRSA skin infection. [source] High-sensitive neural network ammonia sensor based on shear horizontal surface acoustic wave devicesJOURNAL OF CHEMOMETRICS, Issue 10 2008Chi-Yen Shen Abstract In this paper, a shear horizontal surface acoustic wave devices coated with L-glutamic acid hydrochloride were applied as ammonia sensors. This sensor has shown high sensitivity and fast responses to ppb-level ammonia. The frequency shift linearly increased as the ammonia concentration increased from 40 to 400,ppb in dry environment. In the humid environment, the frequency shift gradually decreased with ammonia concentration increasing. In order to precisely estimate the ammonia in humid environment, two different neural models, the conventional feedforward neural network and quantum neural network, were used as the identifier and their performances were reported and compared. Copyright © 2008 John Wiley & Sons, Ltd. [source] Novel Composites Constituted from Hafnia and a Polymer-Derived Ceramic as an Interface: Phase for Severe Ultrahigh Temperature ApplicationsJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 10 2007Sudhir Brahmandam HfO2,SiCN (polymer-derived silicon carbonitride) composites were prepared by two methods. In one case, equal volume fractions of HfO2 and pyrolyzed powders of SiCN were co-sintered, to create a particulate composite. The second type, called interface composites, were prepared by coating HfO2 particles with a thin film of the polymer precursor, followed by sintering so that densification and pyrolysis of the precursor occurred simultaneously; this process results in a ,5-nm-thick grain boundary film constituted from Hf, O, and Si. The fracture properties and environmental degradation (in a humid environment at a velocity of 17.6,35.0 cm/s at 1300°C) of these two composites were measured. They were compared with the properties of a reference material made by sintering HfO2 powders without any additives, under similar conditions (1450°C for 2 h in air). The interface composite yielded the highest sintered density (0.90), exhibited negligible grain growth, and possessed the highest fracture strength (110 MPa). The strength remained immune to hydrothermal oxidation for several hundred hours. In contrast, the particulate composite suffered severe degradation in strength after hydrothermal exposure. The interface composites, with their highly refractory grain boundaries, represent a new class of ceramics for structural applications in harsh environments and at ultrahigh temperatures. [source] Effect of improved home ventilation on asthma control and house dust mite allergen levelsALLERGY, Issue 11 2009G. R. Wright Background:, The warm, humid environment in modern homes favours the dust mite population, but the effect of improved home ventilation on asthma control has not been established. We tested the hypothesis that a domestic mechanical heat recovery ventilation system (MHRV), in addition to allergen avoidance measures, can improve asthma control by attenuating re-colonization rates. Methods:, We conducted a randomized double-blind placebo-controlled parallel group trial of the installation of MHRV activated in half the homes of 120 adults with asthma, allergic to Dermatophagoides pteronyssinus. All homes had carpets steam cleaned and new bedding and mattress covers at baseline. The primary outcome was morning peak expiratory flow (PEF) at 12 months. Results:, At 12 months, the primary end-point; change in mean morning PEF as compared with baseline, did not differ between the MHRV group and the control group (mean difference 13.5 l/min, 95% CI: ,2.6 to 29.8, P = 0.10). However, a secondary end-point; evening mean PEF, was significantly improved in the MHRV group (mean difference 24.5 l/min, 95% CI: 8.9,40.1, P = 0.002). Indoor relative humidity was reduced in MHRV homes, but there was no difference between the groups in Der p 1 levels, compared with baseline. Conclusions:, The addition of MHRV to house dust mite eradication strategies did not achieve a reduction in mite allergen levels, but did improve evening PEF. [source] Identification of QTLs affecting adaptive traits in Castanea sativa MillPLANT CELL & ENVIRONMENT, Issue 9 2004M CASASOLI ABSTRACT A QTL analysis for three different adaptive traits was performed in an F1 progeny of Castanea sativa Mill. The female and male parents originated from two Turkish chestnut populations adapted to a drought and humid environment, respectively. QTLs for bud flush, growth and carbon isotope discrimination were detected over a 3-year period. Bud set was also recorded in the last year of measurement. Thirty-five individual QTLs were detected for phenology, 28 for growth and 17 for carbon isotope discrimination, most of them explaining a low to moderate proportion of the total phenotypic variance. QTLs were distributed throughout the whole genome. Temporally stable QTLs were identified for all the traits analysed, with phenology showing the higher proportion of stable QTLs. Interesting phenotypic correlations and co-localizations among QTLs for different adaptive traits were observed, allowing the formulation of an hypothesis about the genetic adaptation of the female parent to drought. [source] Wood/plastic composites co-extruded with multi-walled carbon nanotube-filled rigid poly(vinyl chloride) cap layerPOLYMER INTERNATIONAL, Issue 5 2010Shan Jin Abstract Wood/plastic composites (WPCs) can absorb moisture in a humid environment due to the hydrophilic nature of the wood in the composites, making products susceptible to microbial growth and loss of mechanical properties. Co-extruding a poly(vinyl chloride) (PVC)-rich cap layer on a WPC significantly reduces the moisture uptake rate, increases the flexural strength but, most importantly, decreases the flexural modulus compared to uncapped WPCs. A two-level factorial design was used to develop regression models evaluating the statistical effects of material compositions and a processing condition on the flexural properties of co-extruded rigid PVC/wood flour composites with the ultimate goal of producing co-extruded composites with better flexural properties than uncapped WPCs. Material composition variables included wood flour content in the core layer and carbon nanotube (CNT) content in the cap layer of the co-extruded composites, with the processing temperature profile for the core layer as the only processing condition variable. Fusion tests were carried out to understand the effects of the material compositions and processing condition on the flexural properties. Regression models indicated all main effects and two powerful interaction effects (processing temperature/wood flour content and wood flour content/CNT content interactions) as statistically significant. Factors leading to a fast fusion of the PVC/wood flour composites in the core layer, i.e. low wood flour content and high processing temperature, were effective material composition and processing condition parameters for improving the flexural properties of co-extruded composites. Reinforcing the cap layer with CNTs also produced a significant improvement in the flexural properties of the co-extruded composites, insensitive to the core layer composition and the processing temperature condition. Copyright © 2009 Society of Chemical Industry [source] Combustion of Environmentally Altered Molybdenum Trioxide NanocompositesPROPELLANTS, EXPLOSIVES, PYROTECHNICS, Issue 3 2006Kevin Moore Abstract Nanocomposite thermite mixtures are currently under development for many primer applications due to their high energy densities, high ignition sensitivity, and low release of toxins into the environment. However, variability and inconsistencies in combustion performance have not been sufficiently investigated. Environmental interactions with the reactants are thought to be a contributing factor to these variabilities. Combustion velocity experiments were conducted on aluminum (Al) and molybdenum trioxide (MoO3) mixtures to investigate the role of environmental interactions such as light exposure and humidity. While the Al particles were maintained in an ambient, constant environment, the MoO3 particles were exposed to UV or fluorescent light, and highly humid environments. Results show that UV and fluorescent lighting over a period of days does not significantly contribute to performance deterioration. However, a humid environment severely decreases combustion performance if the oxidizer particles are not heat-treated. Heat treatment of the MoO3 greatly increases the material's ability to resist water absorption, yielding more repeatable combustion performance. This work further quantifies the role of the environment in the decrease of combustion performance of nanocomposites over time. [source] Monitoring chloramines and bromamines in a humid environment using selected ion flow tube mass spectrometryRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 12 2010Wan-Ping Hu The selectivity and sensitivity of selected ion flow tube mass spectrometry (SIFT-MS) for individual breath analysis of haloamines has been improved by heating the flow tube in a commercial instrument to around 106°C. Data is presented showing the marked reduction in the number density of water clusters of product ions of common breath metabolites that are isobaric with the product ions from monochloramine and monobromamine that are used to monitor the haloamine concentrations. These results have direct relevance to the real-time monitoring of chloramines in drinking water, swimming pools and food processing plants. However, once the isobaric overlaps from water cluster ions are reduced at the higher temperatures, there is no conclusive evidence showing the presence of haloamines on single breath exhalations in the mid parts per trillion range from examination of the breaths of volunteers. Copyright © 2010 John Wiley & Sons, Ltd. [source] Ecogeographic variation in human nasal passagesAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 1 2009Todd R. Yokley Abstract Theoretically, individuals whose ancestors evolved in cold and/or dry climates should have greater nasal mucosal surface area relative to air volume of the nasal passages than individuals whose ancestors evolved in warm, humid climates. A high surface-area-to-volume (SA/V) ratio allows relatively more air to come in contact with the mucosa and facilitates more efficient heat and moisture exchange during inspiration and expiration, which would be adaptive in a cold, dry environment. Conversely, a low SA/V ratio is not as efficient at recapturing heat and moisture during expiration and allows for better heat dissipation, which would be adaptive in a warm, humid environment. To test this hypothesis, cross-sectional measurements of the nasal passages that reflect surface area and volume were collected from a sample of CT scans of patients of European and African ancestry. Results indicate that individuals of European descent do have higher SA/V ratios than individuals of African descent, but only when decongested. Otherwise, the two groups show little difference. This pattern of variation may be due to selection for different SA/V configurations during times of physical exertion, which has been shown to elicit decongestion. Relationships between linear measurements of the skeletal nasal aperture and cavity and cross-sectional dimensions were also examined. Contrary to predictions, the nasal index, the ratio of nasal breadth to nasal height, is not strongly correlated with internal dimensions. However, differences between the nasal indices of the two groups are highly significant. These results may be indicative of different adaptive solutions to the same problem. Am J Phys Anthropol, 2009. © 2008 Wiley-Liss, Inc. [source] Two wooden coffins from the Shakhoura Necropolis, BahrainARABIAN ARCHAEOLOGY AND EPIGRAPHY, Issue 2 2004Søren Fredslund Andersen This article presents a detailed analysis of two wooden coffins from the 1st centuries BC/AD on Bahrain. New C14 dates are published of samples taken from the coffins, and their method of manufacture is reconstructed. The unexpected conservation of wood in a humid environment like Bahrain is explained. [source] Sulfonated polybenzimidazoles: Proton conduction and acid,base crosslinkingJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 16 2010Owen D. Thomas Abstract A series of soluble, benzimidazole-based polymers containing sulfonic acid groups (SuPBI) has been synthesized. SuPBI membranes resist extensive swelling in water but are poor proton conductors. When blended with high ion exchange capacity (IEC) sulfonated poly(ether ether ketone) (SPEEK), a polymer that has high proton conductivity but poor mechanical integrity, ionic crosslinks form reducing the extent of swelling. The effect of sulfonation of PBI on crosslinking in these blends was gauged through comparison with nonsulfonated analogs. Sulfonic acid groups present in SuPBI compensate for acid groups involved in crosslinking, thereby increasing IEC and proton conductivity of the membrane. When water uptake and proton conductivity were compared to the IEC of blends containing either sulfonated or nonsulfonated PBI, no noticeable distinction between PBI types could be made. Comparisons were also made between these blends and pure SPEEK membranes of similar IEC. Blend membranes exhibit slightly lower maximum proton conductivity than pure SPEEK membranes (60 vs. 75 mS cm,1) but had significantly enhanced dimensional stability upon immersion in water, especially at elevated temperature (80 °C). Elevated temperature measurements in humid environments show increased proton conductivity of the SuPBI membranes when compared with SPEEK-only membranes of similar IEC (c.f. 55 for the blend vs. 42 mS cm,1 for SPEEK at 80 °C, 90% relative humidity). © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3640,3650, 2010 [source] Combustion of Environmentally Altered Molybdenum Trioxide NanocompositesPROPELLANTS, EXPLOSIVES, PYROTECHNICS, Issue 3 2006Kevin Moore Abstract Nanocomposite thermite mixtures are currently under development for many primer applications due to their high energy densities, high ignition sensitivity, and low release of toxins into the environment. However, variability and inconsistencies in combustion performance have not been sufficiently investigated. Environmental interactions with the reactants are thought to be a contributing factor to these variabilities. Combustion velocity experiments were conducted on aluminum (Al) and molybdenum trioxide (MoO3) mixtures to investigate the role of environmental interactions such as light exposure and humidity. While the Al particles were maintained in an ambient, constant environment, the MoO3 particles were exposed to UV or fluorescent light, and highly humid environments. Results show that UV and fluorescent lighting over a period of days does not significantly contribute to performance deterioration. However, a humid environment severely decreases combustion performance if the oxidizer particles are not heat-treated. Heat treatment of the MoO3 greatly increases the material's ability to resist water absorption, yielding more repeatable combustion performance. This work further quantifies the role of the environment in the decrease of combustion performance of nanocomposites over time. [source] | |||||||||||||||||||