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Stripping
Kinds of Stripping Terms modified by Stripping Selected AbstractsInfluence of temperature on mass transfer in an incomplete trapping supported liquid membrane extraction of triazole fungicidesJOURNAL OF SEPARATION SCIENCE, JSS, Issue 7 2009Luke Chimuka Abstract The influence of temperature in a supported liquid membrane (SLM) extraction of triazole fungicides was investigated. The mass transfer parameters such as diffusion coefficient, flux and apparent viscosity were determined at temperatures ranging from 5 to 40°C. Increase in temperature led to an increase in diffusion coefficient and flux with a flowing acceptor solution. The apparent viscosity also decreased with an increase in temperature. However, the increase in mass transfer parameters did not result in an overall increase in extraction efficiency with a stagnant or circulation acceptor phase. Stripping of the analytes from the membrane into the acceptor phase as well as the configuration of the extraction unit could have limited the influence of temperature on mass transfer. The partition coefficient of analytes from the acceptor solution to the membrane, KA, was found to be much higher than that from the donor solution to the membrane KD, thus triazole compounds preferred to remain in the membrane even with an increased extraction temperature. [source] Assessment of methods for the determination of digestibilities of feed ingredients for Tra catfish, Pangasinodon hypothalamusAQUACULTURE NUTRITION, Issue 4 2010T.T.T. HIEN Abstract In this study, we undertook a series of experiments to assess different faecal-collection methods and also the digestibilities of a range of feed ingredients when fed to Tra catfish (Pangasinodon hypothalamus). Apparent digestibility coefficients for dry matter, energy and nitrogen for a reference diet were also determined from faeces collected by way of settlement at 2-h intervals from 2 to 24 h. No significant effect of sample collection time on the digestibility values was observed. Stripping was attempted, but was not considered a suitable method for collecting digesta from Tra catfish. Dissection collection was also evaluated. Values determined from dissection collection were lower than those from using settlement. In a second experiment, a suite of test ingredients was combined with a reference diet component in a 30 : 70 ratio to determine the ingredients for dry matter, energy and nitrogen digestibilities. Ingredients included were trash-fish, defatted rice bran, wet full-fat rice bran, dried full-fat rice bran, broken rice, cassava, soybean and fish meals. Collection of faeces by settlement was used for determining the digestibility of each of the ingredients. The results showed that Tra catfish can efficiently digest protein and energy from a wide range of feed ingredients and nutrient sources. [source] Membrane associated nonmuscle myosin II functions as a motor for actin-based vesicle transport in clam oocyte extractsCYTOSKELETON, Issue 10 2007Ana S. DePina Abstract Nonmuscle myosin II (Myo2) has been shown to associate with membranes of the trans -Golgi network and to be involved in Golgi to ER retrograde protein transport. Here, we provide evidence that Myo2 not only associates with membranes but functions to transport vesicles on actin filaments (AFs). We used extracts from unactivated clam oocytes for these studies. AFs assembled spontaneously in these extracts and myosin-dependent vesicle transport was observed upon activation. In addition, actin bundles formed and moved relative to each other at an average speed of ,0.30 ,m/s. Motion analysis revealed that vesicles moved on the spontaneously assembled AFs at speeds greater than 1 ,m/s. The motor on these vesicles was identified as a member of the nonmuscle Myo2 family based on sequence determination by Edman chemistry. Vesicles in these extracts were purified by sucrose gradient centrifugation and movement was reconstituted in vitro using skeletal muscle actin coated coverslips. When peripheral membrane proteins of vesicles including Myo2 were removed by salt stripping or when extracts were treated with an antibody specific to clam oocyte nonmuscle Myo2, vesicle movement was inhibited. Blebbistatin, a Myo2 specific inhibitor, also blocked vesicle movement. Myo2 light chain kinase activity was found to be essential for vesicle movement and sliding of actin bundles. Together, our data provide direct evidence that nonmuscle Myo2 is involved in actin-dependent vesicle transport in clam oocytes. Cell Motil. Cytoskeleton 2007. © 2007 Wiley-Liss, Inc. [source] Visualized Sclerotherapy of Varicose VeinsDERMATOLOGIC SURGERY, Issue 2010MAMORU KIKUCHI MD BACKGROUND The spread and movement of sclerosant after injection during sclerotherapy is difficult to monitor. OBJECTIVE To develop a new visualization method that allows monitoring of sclerosant dosage and flow during sclerotherapy. METHODS We used a photodynamic eye (PDE) to perform indocyanine green (ICG) imaging. ICG produces strong fluorescence detectable using PDE and allows monitoring of sclerosant spread through blood vessels in real time. We performed visualized sclerotherapy on 50 limbs, comprising high ligation and sclerotherapy (35 limbs), stripping and sclerotherapy (10 limbs), and sclerotherapy alone (5 limbs). RESULTS In all cases, fluorescence imaging of the injected sclerosant was possible. No complications resulted from combining ICG and polidocanol in any of the patients, all of whom received follow-up evaluations at 1 week, 1 month, and 3 months after treatment. CONCLUSIONS Our new method not only avoids the risk of radiation exposure, but also allows for simple observation of sclerosant range of access, determination of the dosage for each lesion, and accurate administration of therapy to target lesions. This method will contribute to further advances in sclerotherapy, given that it allows administration of sclerosant and visual confirmation of optimal injection dosage, speed, and movement of sclerosant after injection. The authors have indicated no significant interest with commercial supporters. [source] The Livelihoods Gap: Responding to the Economic Dynamics of Vulnerability in SomaliaDISASTERS, Issue 1 2002Andre Le Sage A ,livelihoods gap' has become evident in international aid delivery to Somalia. Existing aid interventions do not address the economic dynamics of vulnerability resulting from Somalia's long history of predatory development and asset stripping. To prevent poor households' regular return to sub-subsistence income levels after a brief period of plenty, this paper argues that aid agencies should reorient and expand existing interventions to assist poor households to capitalise on temporary improvements in environmental and security conditions. As a corollary to emergency relief and efforts to construct state institutions, it is necessary to devise country-wide interventions that will rebuild household asset bases by protecting savings during times of stress and ensuring that markets benefit poor producers. [source] Continuous Intraoperative Transesophageal Echocardiography during Pericardiectomy for Constrictive Pericarditis Revealing Dynamic Change in Chamber SizeECHOCARDIOGRAPHY, Issue 5 2005Babak Kasravi M.D. We review a case of a 50-year-old man with diagnosis of constrictive pericarditis, who underwent pericardial stripping with continuous intraoperative transesophageal echocardiography (TEE). This patient demonstrates the immediate dynamic changes in chamber size after successful surgical removal of pericardium as demonstrated by TEE. [source] Carbon Nanotubes Paste Electrodes.ELECTROANALYSIS, Issue 7-8 2007A New Alternative for the Development of Electrochemical Sensors Abstract In this work we summarize the recent activities of our group regarding the analytical performance of a new composite material, the so-called carbon nanotubes paste electrode (CNTPE) obtained by dispersion of multiwall carbon nanotubes in mineral oil. The electrocatalytic properties towards different redox systems, especially those involved in important enzymatic reactions are discussed. Significant shifting in the overpotentials for the oxidation and/or reduction of hydrogen peroxide, NADH, phenol, catechol, dopamine, ascorbic acid, uric acid and hydroquinone are obtained at CNTPE in comparison with the analogous graphite paste electrode (CPE). The usefulness of the electrode as a matrix for immobilizing enzymes is also demonstrated. Highly sensitive and selective glucose quantification is accomplished even without using permselective films or redox mediators. Enzymatic biosensors obtained by incorporation of lactate oxidase, polyphenol oxidase and alcohol dehydrogenase/NAD+ within the composite material have allowed the successful quantification of lactate, phenol, dopamine, catechin and ethanol. The sensitive quantification of traces of oligonucleotides and double stranded calf thymus DNA by adsorptive stripping is reported. The confined DNA layer demonstrated to be stable either in air, acetate or phosphate buffer. The advantages of incorporating copper particles for the quantification of amino acids and albumin is also discussed. [source] Palladium Sub-Nanoparticle Decorated ,Bamboo' Multi-Walled Carbon Nanotubes Exhibit Electrochemical Metastability: Voltammetric Sensing in Otherwise Inaccessible pH RangesELECTROANALYSIS, Issue 24 2006Xiaobo Ji Abstract A generic approach for the detection of electroactive species in potential ranges that would normally be inhibited due to the stripping of the electrocatalytic material is presented. We demonstrate, via the example of the electrochemical oxidation of hydrazine, that palladium nanoparticle (< 1,nm) decorated bamboo multi-walled carbon nanotubes exhibit a metastability such that they allow the sensing of hydrazine in the pH range where palladium metal would normally be voltammetrically stripped (oxidized) from the surface of convectional electrodes. [source] Enhanced Resolution of Copper and Bismuth by Addition of Gallium in Anodic Stripping Voltammetry with the Bismuth Film ElectrodeELECTROANALYSIS, Issue 24 2006Chad Prior Abstract This paper presents the enhanced analysis of copper on a bismuth electrode upon addition of gallium(III). The presence of gallium alleviates the problems of overlapping stripping signals usually observed between copper and bismuth when using the Bismuth Film Electrode. In addition, it has been found that the presence of gallium improves the reproducibility of the bismuth stripping signal. Simultaneous deposition of copper and bismuth at ,1500,mV for 2,minutes in a supporting electrolyte composed of 0.1,M pH,4.75 acetate buffer with 250,,g L,1 gallium yields well resolved copper and bismuth signals when analyzed with square-wave anodic stripping voltammetry. Simultaneous analysis of copper and lead yielded linear calibration plots in the range 10 to 100,,g L,1 with regression coefficients of 0.997 and 0.994 respectively. The theoretical detection limit for copper was calculated to be 4.98,,g L,1 utilizing a 2,minutes deposition time. The relative standard deviation for a copper concentration of 50,,g L,1 was 1.6% (n=10). [source] Highly Sensitive and Selective Measurement of Bismuth in Seawater and Drug with 1,2-Phenylenedioxydiacetic Acid by Cathodic Adsorptive Stripping VoltammetryELECTROANALYSIS, Issue 7 2006B. Gholivand Abstract A new method is presented for determination of bismuth based on cathodic adsorptive stripping of complex bismuth with 1,2-phenylenedioxydiacetic acid (PDA) at a hanging mercury drop electrode (HMDE). The effect of various parameters such as pH, concentration of ligand, accumulation potential and accumulation time on the selectivity and sensitivity were studied. The optimum conditions for determination of bismuth include nitric acid concentration 0.01,M, 8.0×10,4,M PDA and accumulation time 120,s, accumulation potential of ,200,mV. The limits of detection are 0.25 and 0.05,nM, and responses are linear 1,1000 and 0.1,400,nM at tacc of 60 and 120,s, respectively. Many common anions and cations do not interfere in the determination of bismuth. The method was applied to the determination of bismuth in some real samples such as sea , and spring water and drug. [source] Elevated Temperature Electrochemical Studies of Preoxidized Nickel Electrodes in the Presence of SulfideELECTROANALYSIS, Issue 15 2004Ian Streeter Abstract The electrochemical response of a preoxidized nickel electrode to increasing additions of sulfide has been examined over temperature range from 25 to 70,°C. In the presence of sulfide a stripping like response was observed at all temperatures. The results detailed show that as the temperature is increased the sensitivity increases from 3.4 to 13.5 A M,1 for the determination of sulfide. [source] Nanodiamond Thin Film Electrodes: Metal Electro-Deposition and Stripping ProcessesELECTROANALYSIS, Issue 3 2003Hian, Lau Chi Abstract The properties of a nanodiamond thin film deposit formed on titanium substrates in a microwave-plasma enhanced CVD process, are investigated for applications in electroanalysis. The nanodiamond deposit consists of intergrown nano-sized platelets of diamond with a high sp2 carbon content giving it high electrical conductivity and electrochemical reactivity. Nanodiamond thin film electrodes (of approximately 2,,m thickness) are characterized by electron microscopy and electrochemical methods. First, for a reversible one electron redox system, Ru(NH3)63+/2+, nanodiamond is shown to give well-defined diffusion controlled voltammetric responses. Next, metal deposition processes are shown to proceed on nanodiamond with high reversibility and high efficiency compared to processes reported on boron-doped diamond. The nucleation of gold is shown to be facile at edge sites, which are abundant on the nanodiamond surface. For the deposition and stripping of both gold and copper, a stripping efficiency (the ratio of electro-dissolution charge to electro-deposition charge) of close to unity is detected even at low concentrations of analyte. The effect of thermal annealing in air is shown to drastically modify the electrode characteristics probably due to interfacial oxidation, loss of active sp2 sites, and loss of conductivity. [source] Experimental study of flue gas desulfurization using landfill leachateENVIRONMENTAL PROGRESS & SUSTAINABLE ENERGY, Issue 1 2007Ding Sang-lan Abstract Because of the complexity of landfill leachate's composition, the reaction mechanism of SO2 in flue gas with landfill leachate was studied. The experimental results indicated that the factors influencing SO2 absorption efficiency using landfill leachate as the scrubbing medium were, in decreasing order of importance, pH, Fe2+, Mn2+, and Cl, as catalysts and the concentration of toluene and ethanol. Experiments showed that the pH of landfill leachate was the key factor governing both SO2 absorption and ammonia stripping. With the initial pH of 8.5, the terminal pH 6.0 and L/G ratio 3 L/m3, experimental results showed that average absorption efficiency of SO2 and the stripping efficiency of ammonia were 85 and 44%, respectively. The use of catalysts such as Fe2+ and Mn2+ was important for SO2 absorption when the pH value was below 7.0. The catalytic activity of Mn2+ was greater than that of Fe2+ although the reaction steps were very similar. Ethanol inhibits HSO3,/SO32, oxidation. The HSO3,/SO32, oxidation process improves the solubility of organics such as toluene in the leachate. The solute products of organics were water-soluble and biodegradable and could be used as substrates for bacteria in the post biotreatment. The factorial experiment results showed the effect of Cl,, Fe2+, and Mn2+ as catalysts on the HSO3,/SO32, oxidation has a greater positive impact than ethanol's inhibitory effect on the HSO3,/SO32, oxidation. © 2006 American Institute of Chemical Engineers Environ Prog 26:25,32, 2007 [source] Remediation of sites contaminated by oil refinery operationsENVIRONMENTAL PROGRESS & SUSTAINABLE ENERGY, Issue 1 2006S. Khaitan The oil industry contributes to contamination of groundwater and aquifers beneath refineries and oil terminals. The successful remediation of a contaminated site requires understanding both the hydrogeology and the nature and extent of contamination. The physical,chemical and biological mechanisms that govern contaminant release, transport and fate in soils, sediments, and associated fluid phases must be understood and quantified. In addition, understanding the flow and entrapment of nonaqueous phase liquids (NAPLs) including lighter-than-water nonaqueous phase liquids (LNAPLs) in contaminated aquifers is important for the effective design of the recovery and remediation schemes. Current remedial technologies and risk assessment techniques to remediate former oil refinery sites contaminated by NAPLs are described in this paper. Emphasis is given to the most promising remediation techniques such as pump-and-treat, on-site bioremediation, phytoremediation, in situ soil washing, and thermal-based technologies, such as steam-enhanced extraction. Some enhancements to pump-and-treat techniques such as solvent flushing, polymer enhanced flushing, and air stripping are also discussed. Finally, important risk-based cleanup criteria associated with contaminated soil at refineries are presented. © 2005 American Institute of Chemical Engineers Environ Prog, 2005 [source] CCL17 transgenic mice show an enhanced Th2-type response to both allergic and non-allergic stimuliEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 8 2006Yuichiro Tsunemi Dr. Abstract CC chemokine ligand (CCL)17 is implicated in the pathogenesis of atopic dermatitis (AD). To study the effect of CCL17 produced by keratinocytes (KC) during inflammation, we created transgenic (Tg) mice in which CCL17 is overexpressed in KC. Th2-type contact hypersensitivity (CHS) was enhanced and Th1-type CHS was suppressed in these mice. Increased numbers of CC chemokine receptor (CCR)4+ cells and mast cells infiltrated in Tg mice. Levels of IL-4 mRNA were higher and those of IFN-, mRNA were lower in both acute and chronic CHS. Higher levels of serum IgE were observed after CHS. Numbers of CCR4+ cells among PBMC were increased in Tg mice challenged acutely on the trunk. Chronic irritation with croton oil induced dermatitis and an elevation of serum IgE levels. Tg mice showed enhanced ear swelling after tape stripping. CCL17 was thought to modify the inflammation caused by sensitizing reagents as well as irritant reagents by attracting CCR4+ cells into the lesional skin and creating a Th2-dominant condition. AD-like conditions such as increased number of mast cells and elevated levels of serum IgE were observed. Thus, CCL17 may participate in the pathogenesis of skin diseases such as AD by regulating both allergic and irritant inflammation. [source] Effects of metals on skin permeability barrier recoveryEXPERIMENTAL DERMATOLOGY, Issue 8 2010Mitsuhiro Denda Please cite this paper as: Effects of metals on skin permeability barrier recovery. Experimental Dermatology 2010; 19: e124,e127. Abstract:, We previously demonstrated that the electrical state of the skin surface influences epidermal permeability barrier homeostasis. At the interface between different materials, electrons are localized heterogeneously and induce electrical potential. In the present study, we evaluated the effects of metals on the barrier recovery. When we put pure gold plate on skin immediately after tape stripping, the barrier recovery rate was faster than the control. The acceleration of barrier recovery was blocked when the plate was earthed (grounded). When a plastic membrane was sandwiched between the plate and the skin, the recovery was delayed in comparison with the control. We then used a germanium diode to regulate the current flow between the plate and the earth. When the current was blocked, the barrier recovery was accelerated, but when the current was not blocked, the recovery was not accelerated. These results suggest that localization of electron might affect for the barrier recovery rate. The level of interfacial electric potential would be different due to the electrochemical property of metal. Thus, we next evaluated the effects of other metals. With samarium, zirconium, iridium and silver, the barrier recovery rate was faster than in the case of gold, while a platinum plate induced slower recovery than in the case of gold. There was a significant correlation between work function of each metal and barrier recovery rate. These results suggest that electron donation from outside accelerated the skin barrier recovery. [source] Topical treatment with thiazolidinediones, activators of peroxisome proliferator-activated receptor-,, normalizes epidermal homeostasis in a murine hyperproliferative disease modelEXPERIMENTAL DERMATOLOGY, Issue 3 2006Marianne Demerjian Abstract:, In a murine model of epidermal hyperplasia reproducing some of the abnormalities of several common skin disorders, we previously demonstrated the antiproliferative and pro-differentiating effects of peroxisome proliferator-activated receptor (PPAR),, PPAR,/,, and liver X receptor activators. Unlike other subgroups of PPAR activators, thiazolidinediones (TZDs), a family of PPAR, ligands, did not inhibit keratinocyte proliferation in normal murine skin. Here, we studied the effects of two TZDs, namely ciglitazone (10 mM) and troglitazone (1 mM), in the same murine model where epidermal hyperproliferation was reproduced by repeated barrier abrogation with tape stripping. Topical treatment with ciglitazone and troglitazone resulted in a marked and significant decrease in epidermal thickness. Furthermore, in all TZD-treated groups, we observed a significant decrease in keratinocyte proliferation using proliferating cell nuclear antigen, 5-bromo-2,-deoxyuridine, and tritiated thymidine incorporation. However, using the terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling assay, we found no difference in apoptosis between different treatments, emphasizing that it is the antiproliferative role of these activators that accounts for the decrease of epidermal thickness. Finally, using immunohistochemical methods, we determined the effects of ciglitazone on keratinocyte differentiation in this hyperproliferative model. We observed an increased expression of involucrin and filaggrin following ciglitazone treatment, suggesting a pro-differentiating action of TZDs in this model. In summary, topical TZDs significantly reduce epidermal keratinocyte proliferation while promoting differentiation in a murine model of hyperproliferative epidermis. Together, these results suggest that in addition to their metabolic effects currently in use in the treatment of type 2 diabetes, topical TZDs could be considered as potential alternative therapeutic agents in hyperproliferative skin diseases such as psoriasis. [source] Evidence for synaptic stripping by cortical microgliaGLIA, Issue 4 2007Bruce D. Trapp Abstract Recent studies have described significant demyelination and microglial activation in the cerebral cortex of brains from multiple sclerosis patients. To date, however, experimental models of cortical demyelination or cortical inflammation have not been extensively studied. In this report we describe focal cortical inflammation induced by stereotaxic injection of killed bacteria (BCG), followed 1 month later by subcutaneous injection of the same antigen, a protocol that overcomes the immune privilege of the cortex. Intracerebral BCG injection produced focal microglial activation at the injection site (termed acute lesion). Ten days after peripheral challenge (termed immune-mediated lesion), larger areas and higher densities of activated microglia were found near the injection site. In both paradigms, activated microglia and/or their processes closely apposed neuronal perikarya and apical dendrites. In the immune-mediated lesions, ,45% of the axosomatic synapses was displaced by activated microglia. Upon activation, therefore, cortical microglial migrate to and strip synapses from neuronal perikarya. Since neuronal pathology was not a feature of either the acute or immune-mediated lesion, synaptic stripping by activated microglia may have neuroprotective consequences. © 2006 Wiley-Liss, Inc. [source] Evaluation of Noble Gas Recharge Temperatures in a Shallow Unconfined AquiferGROUND WATER, Issue 5 2009Bradley D. Cey Water table temperatures inferred from dissolved noble gas concentrations (noble gas temperatures, NGT) are useful as a quantitative proxy for air temperature change since the last glacial maximum. Despite their importance in paleoclimate research, few studies have investigated the relationship between NGT and actual recharge temperatures in field settings. This study presents dissolved noble gas data from a shallow unconfined aquifer heavily impacted by agriculture. Considering samples unaffected by degassing, NGT calculated from common physically based interpretive gas dissolution models that correct measured noble gas concentrations for "excess air" agreed with measured water table temperatures (WTT). The ability to fit data to multiple interpretive models indicates that model goodness-of-fit does not necessarily mean that the model reflects actual gas dissolution processes. Although NGT are useful in that they reflect WTT, caution is recommended when using these interpretive models. There was no measurable difference in excess air characteristics (amount and degree of fractionation) between two recharge regimes studied (higher flux recharge primarily during spring and summer vs. continuous, low flux recharge). Approximately 20% of samples had dissolved gas concentrations below equilibrium concentration with respect to atmospheric pressure, indicating degassing. Geochemical and dissolved gas data indicate that saturated zone denitrification caused degassing by gas stripping. Modeling indicates that minor degassing (<10% ,Ne) may cause underestimation of ground water recharge temperature by up to 2°C. Such errors are problematic because degassing may not be apparent and degassed samples may be fit by a model with a high degree of certainty. [source] A Screening Model for Injection-Extraction Treatment Well Recirculation System DesignGROUND WATER MONITORING & REMEDIATION, Issue 4 2008Monica Y. Wu Implementation of injection-extraction treatment well pairs for in situ, in-well, or on-site remediation may be facilitated by development and application of modeling tools to aid in hydraulic design and remediation technology selection. In this study, complex potential theory was employed to derive a simple one-step design equation and related type curves that permit the calculation of the extraction well capture zone and the hydraulic recirculation between an injection and extraction well pair oriented perpendicular to regional flow. This equation may be used to aid in the design of traditional fully screened injection-extraction wells as well as innovative tandem recirculating wells when an adequate geologic barrier to vertical ground water flow exists. Simplified models describing in situ bioremediation, in-well vapor stripping, and in-well metal reactor treatment efficiency were adapted from the literature and coupled with the hydraulic design equation presented here. Equations and type curves that combine the remediation treatment efficiency with the hydraulic design equation are presented to simulate overall system treatment efficiency under various conditions. The combined model is applied to predict performance of in situ bioremediation and in-well palladium reactor designs that were previously described in the literature. This model is expected to aid practitioners in treatment system screening and evaluation. [source] An Evaluation of Physicochemical Treatment Technologies for Water Contaminated with MTBEGROUND WATER MONITORING & REMEDIATION, Issue 4 2000Arturo A. Keller Treatment of methyl tertiary-butyl ether (MTBE) from contaminated surface and ground water supplies presents specific challenges due to the physicochemical properties of MTBE that depend strongly on its hydrophilic nature, and translate into a high solubility in water, and low Henry's constant and low affinity for common adsorbents. We evaluate four treatment technologies-air stripping, granular activated carbon (GAC), hydrophobic hollow fiber membranes, and advanced oxidation processes (AOP)-using ozone or ozone/hydrogen peroxide. Experimental work was carried out to generate parameter values necessary for the design of these processes. Ten different flow rates/concentration combinations were evaluated in our designs to cover the range from high flow rate/low concentration typical of surface water and ground water drinking water supplies to low flow rate/high concentration typical of ground water remediation sites. For all cases, the processes were designed to produce effluent water of 5 ,g/L or less. Capital costs and operation and maintenance costs were determined at the feasibility level by using standard engineering estimating practices. Air stripping is the lowest cost technology for high flow rales (100 to 1000 gpm) if no air treatment is required. Hollow fiber membranes are the lowest cost technology for flow rates of 10 to 100 gpm if no air treatment is required, which is typical at these low flow rates. GAC will be most costeffective at all flow rates if air treatment is required and the influent water has low levels of other organic compounds. AOP using ozone or ozone/hydrogen peroxide is in all cases more expensive than the alternative technologies, and there are sufficient uncertainties at this point with respect to byproducts of AOP to warrant further study of this technology. The cost of treating MTBE-contaminated water for conventional technologies such as air stripping and GAC is 40% to 80% higher than treating water contaminated only with other hydrocarbons such as benzene. [source] Lessons from the Russian Meltdown: The Economics of Soft Legal ConstraintsINTERNATIONAL FINANCE, Issue 3 2002Enrico Perotti On 17 August 1998, Russia abandoned its exchange rate regime, defaulted on its domestic public debt and declared a moratorium on all private foreign liabilities, which was equivalent to an outright default. The depth and speed of the Russian meltdown shocked the international markets, and precipitated a period of serious financial instability. Important lessons on issues of bank supervision and international stability can be learned by understanding the roots of such a crisis. The visible reason of the crisis was an unsustainable fiscal deficit coupled with massive capital flight, but what were their underlying causes? We argue that the structure of individual incentives in a context of capture of state decisions by special interests, compounded by a rouble overvaluation driven by exceptional international support, helps to explain the build,up of non,payment, theft and capital flight that led to the crisis. We offer an explicit model of rational collective non,compliance, cash stripping and rational collective non,payment which led to the fiscal and banking crisis and, ultimately, to a complete meltdown. In our view, the banking sector was already insolvent prior to the crisis, and contributed directly and indirectly to it. We conclude with a radical policy proposal for a stable banking system for Russia, appropriate for its current capacity for legal and supervisory enforcement. It is based on a segmented, narrow banking sector, concentration in commercial banking and a cautious extension of deposit insurance. [source] Escape from microenvironmental control and progression of intraepithelial neoplasiaINTERNATIONAL JOURNAL OF CANCER, Issue 6 2005Weitian Zhang Abstract We previously reported that normal human keratinocytes controlled neoplastic progression of tumor cells at an early stage of transformation in stratified squamous epithelium. We now studied if cells at a more advanced stage of transformation were also subject to such microenvironmental control. To accomplish this, 3D human tissues that mimic intraepithelial neoplasia were fabricated by mixing genetically marked (,-gal), early-stage (II-4 cells) or advanced-stage (SCC13) transformed keratinocytes with normal keratinocytes, and tumor cell fate and phenotype were monitored in organotypic culture and after surface transplantation to nude mice. In vivo, SCC13 cells evaded local growth suppression to undergo connective tissue invasion at significantly lower tumor cell volumes (12:1, 50:1 normal:tumor cells) than II-4 cells. This behavior was explained by the growth suppression of II-4 cells, while advanced-stage tumor cells escaped this control and continued to undergo clonal expansion in mixed cultures to form large, intraepithelial tumor clusters. These communities of tumor cells underwent autonomous growth that was associated with altered expression of markers of differentiation (keratin 1) and cell,cell communication (connexin-43). Furthermore, significantly greater numbers of SCC13 cells expanded into a basal position after low-calcium stripping of suprabasal cells of mixed cultures compared to II-4 cells, suggesting that expansion of these cells enabled tumor cell invasion after transplantation. These findings demonstrated that early tumor development in human stratified squamous epithelium required escape from microenvironmental growth control that was dependent on the transformation stage of intraepithelial tumor cells during the premalignant stage of cancer progression. © 2005 Wiley-Liss, Inc. [source] Endovenous laser ablation for superficial venous insufficiencyINTERNATIONAL JOURNAL OF CLINICAL PRACTICE, Issue 1 2010R. Durai Summary Background:, Endovenous laser ablation (EVLA) is a new minimally invasive alternative to conventional surgery for superficial venous insufficiency and varicose veins, where laser energy is used to ablate the incompetent veins. Discussion:, Endovenous laser ablation avoids the need for surgical incisions, and the complications of surgical exploration of the groin or popliteal fossa, and stripping. The procedure is commonly performed under local anaesthesia, with immediate mobilisation and rapid return to normal activity. Severe varicosity of tributaries may require adjunctive procedures such as microphlebectomy or sclerotherapy. Conclusion:, Early outcomes and cosmesis are superior, and long-term data is accumulating that recurrence of EVLA rates may be lower. [source] Original semiologic standardized evaluation of stratum corneum hydration by Diagnoskin® stripping sampleINTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Issue 3 2004P. Gasser Synopsis In a normal and healthy skin, the regular elimination of the superficial corneocytes, called desquamation, is a fundamental physiologic process intended to protect the barrier function of the skin. This invisible loss of corneocytes, individually or in small groups, is incessantly compensated by the divisions of the proliferative layer and the upward cellular maturation in order to maintain the harmonious renewal of the epidermis and the integrity of the stratum corneum. The harmony of this desquamation process is intimately conditioned by a sufficient hydration of the stratum corneum: (i) an abnormal desquamation leads to a disruption of the water barrier function and consequently to a dehydration tendency of the stratum corneum, and (ii) a cutaneous dryness (whatever the cause) is able to disturb the desquamation process. Protecting the water content of the stratum corneum has always been a major preoccupation of the cosmetic industry scientists. Consequently, the moisturizing properties of a cosmetic product are objectively measured by various explorations directly targeted on the hydration (corneometry) and on the level of the water barrier function (transepidermal water loss (TEWL) measurements), which depends directly on the skin hydration state. This intimate linkage of the desquamation process and the water content of the stratum corneum enable us to suggest an indirect assessment of the hydration from a direct study of the desquamation by examining a skin-stripping sample (D-Squames®) by an optical microscope (linked to a computer). We will describe this already known technique and mainly its new and unpublished semiologic exploitation, named Diagnoskin®, whose advantages are its simplicity and its reproducibility particularly interesting in the case of sequential appraisal of dermatologic or cosmetic treatments. Résumé Sur une peau normale et saine, l'élimination régulière des cornéocytes superficiels, appelée desquamation, est un processus physiologique fondamental destinéà préserver la fonction barrière de la peau. La perte invisible des cornéocytes, individuellement ou par petits paquets cellulaires, est sans cesse compensée par les divisions de la couche germinative et la maturation cellulaire ascensionnelle afin de maintenir le renouvellement harmonieux de l'épiderme et l'intégrité du stratum corneum. L'harmonie de ce processus de desquamation est intimement conditionnée par une hydratation suffisante du stratum corneum: une desquamation anormale aboutit à une perturbation de la fonction barrière et donc à une tendance à la déshydratation du stratum corneum, Une sècheresse cutanée (quelle qu'en soit la cause) va perturber la desquamation. Préserver la teneur en eau du stratum corneum est depuis toujours une préoccupation majeure pour le scientifique de l'industrie cosmétique. L'appréciation objective du caractère hydratant d'une crème cosmétique est d'ailleurs mesuré par diverses explorations directement ciblées sur l'hydratation (cornéométrie) et sur l'état de la fonction barrière (Perte Insensible en Eau ,PIE) qui dépend directement de l'état d'hydratation de la peau. Cette liaison intime du niveau d'hydratation du stratum corneum et du phénomène de desquamation nous a fait proposer une évaluation indirecte de l'hydratation à l'aide d'une étude directe de la desquamation par observation au microscope (reliéà un ordinateur) des prélèvements par stripping des cornéocytes superficiels (D-Squames®). Nous décrirons cette technique déjà connue et surtout son exploitation sémiologique nouvelle et inédite, appelée Diagnoskin® dont les avantages sont sa simplicité et son caractère reproductible particulièrement intéressants pour l'évaluation séquentielle de traitements dermatologiques ou cosmétiques. [source] QUALX: a computer program for qualitative analysis using powder diffraction dataJOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 4 2008Angela Altomare QUALX is a new computer program for phase identification using powder diffraction data. It uses the Powder Diffraction File database, where a search for the phase best matching the experimental powder diffraction pattern is carried out. The program is characterized by a high level of automation: the traditional steps aimed at interpreting the experimental pattern before the search (background estimation, peak search, peak intensity evaluation) are executed automatically. The search may be carried out via constraints on compound name and/or chemical elements. In addition, several graphical options requested interactively enable the user to perform zero point correction evaluation, K,2 stripping and smoothing. The program, written in Fortran95 and C++, runs on PCs under the Windows XP operating system. It is supported by a very effective graphical interface. [source] Contribution of Nitric Oxide Synthase to Improved Early Graft Patency in Human Saphenous Vein Graft Harvested by a Novel ,No-Touch' TechniqueJOURNAL OF CARDIAC SURGERY, Issue 6 2002JCS Tsui Aim: Saphenous vein (SV) is the most commonly used conduit in bypass procedures but has a one-year occlusion rate of 15-30%. A new ,no-touch' technique where the SV is harvested with a cushion of surrounding tissue with no distension has led to improved early patency rates of 5% at 18-months. Nitric oxide (NO), synthesised by nitric oxide synthase (NOS) has properties beneficial to graft patency. Our aim was to study the distribution of NOS in SV harvested by this technique and the effect of distension and removal of perivascular tissue on NOS content of SV. Methods: Following ethical committee approval and patients' informed consent, SVs were harvested from ten patients undergoing coronary artery bypass grafting. A segment of vein was harvested by the conventional technique (surrounding tissue stripped and vein distended with saline); another part was stripped but not distended (,control') and the remaining parts harvested by the ,no-touch' technique. Samples of each segment were taken and transverse sections prepared for NOS identification using 3[H]L-NG nitroarginine (NO Arg) autoradiography and NADPH-diaphorase histochemistry. NOS isoforms were studied using standard immunohistochemistry. Endothelial cells and nerves were also identified using immunohistochemistry with CD31 and NF200 respecitvely, to confirm sources of NOS. Morphometric analysis of NADPH-diaphorase staining was carried out to study tissue NOS content. Results: NO Arg binding representing NOS was preserved on the lumen of ,no-touch' vessels whilst that on conventional and control vessels was reduced. NOS was also localised to the medial smooth muscle cells of all vein segments and to the intact adventitia of ,no-touch' segments. This was confirmed by NADPH-diaphorase staining, which revealed a mean reduction of NOS by 19.5% (p < 0.05, ANOVA) in control segments due to stripping of surrounding tissue alone and a reduction of 35.5% (p < 0.01, AVNOVA) in conventional segments due to stripping and distension, compared to ,no-touch' segments. Adventitial NOS sources in ,no-touch' vessels corresponded to vasa vasorum and paravascular nerves. All three NOS isoforms contributed to the preserved NOS in ,no-touch' vessels. Conclusions: Apart from preserved lumenal NOS, NOS sources are also located in the media and adventitia of SV grafts. These are reduced by both adventitial damage and vein distension during conventional vein harvesting. The ,no-touch' technique avoids these procedures, preserving NOS sources. This may result in improved NO availability in SV harvested by this technique, contributing to the improved patency rates reported. [source] Computer simulation of flow-sheets for the solvent extraction of uranium: a new route to delay the effect of chemical degradation of the organic phase during uranium recovery from acidic sulfate mediaJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 12 2009Alexandre Chagnes Abstract BACKGROUND: The extractants used in solvent extraction processes undergo degradation under thermal, chemical and radiolytical stresses. In the case of uranium plants, tri- n -octylamine, used as an extractant, slowly degrades into di- n -octylamine. Such degradation causes a gradual depletion of the uranium extraction isotherms and as a result, of the efficiency of uranium recovery from feed solutions. The present work highlights a new route to delay this depletion of the extraction efficiency, merely by optimizing the flow-sheets involved in the process. Five flow-sheets have been compared for uranium recovery from acidic sulfate media by a solution of 0.146 mol L,1 tri- n -octylamine in kerosene modified with 5% w/w 1-tridecanol and stripping with a 199 g L,1 Na2CO3 solution. These five flow-sheets include the classical counter-current flow-sheet with four mixers,settlers in extraction and three mixers,settlers in stripping and four unusual combined solvent extraction flow-sheets with two independent extraction stripping loops and with one or two feed inlets. RESULTS: Computer simulation supplied evidence of the strong influence of the studied flow-sheets on the sturdiness of the process. More precisely, the unusual combined solvent extraction flow-sheets appeared to be significantly more efficient than the classical counter-current one and it is shown that an advantage of this can be to delay the negative impact of gradual degradation of tri- n -octylamine on uranium recovery efficiency from acidic sulfate media. CONCLUSION: The replacement of classical counter-current flow-sheets with a unique extraction-stripping loop in unusual combined flow-sheets with two or more independent extraction-stripping loops and with one or more feed inlets is a fruitful approach to delay the periodic addition of fresh tri- n -octylamine necessary for counter-balancing the progressive degradation of the extraction solvent and, as a result, to delay the gradual depletion of the efficiency of uranium recovery. Copyright © 2009 Society of Chemical Industry [source] Strategies to optimize phosphate removal from industrial anaerobic effluents by magnesium ammonium phosphate (MAP) productionJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 1 2009Marta Carballa Abstract BACKGROUND: Owing to more stringent phosphate discharge requirements and the increasing prices of fertilizers, beneficial recovery and reuse of phosphate from industrial anaerobic effluents is becoming an important issue. Phosphate recovery by struvite or magnesium ammonium phosphate (MAP) permits its recycling in the fertilizer industry because struvite is a valuable slow release fertilizer. Two different approaches to MAP crystallization depending on initial levels of phosphate in the wastewaters were tested and compared. RESULTS: For low-phosphate-containing anaerobic effluents (<30 mg PO43, -P L,1), a novel approach using ureolytic induced MAP formation with MgO addition appeared to be suitable. The residual phosphate concentrations in the effluent ranged from 5 to 7 mg PO43, -P L,1 and the separated matter contained residual amounts of Mg(OH)2. High-phosphate-containing anaerobic effluents (100 to 120 mg PO43, -P L,1) were treated efficiently using air stripping combined with MgCl2 and NaOH reagents, yielding residual phosphate levels of 8 to 15 mg PO43, -P L,1 and spherical pure MAP crystals of 0.5 to 2 mm. CONCLUSION: Results show that depending on the initial phosphate concentrations in the wastewaters and the ammonium and magnesium levels, the strategy selected for struvite crystallization is a determinative factor in achieving a cost effective technology. Copyright © 2008 Society of Chemical Industry [source] Differences in woody vegetation are unrelated to use by African elephants (Loxodonta africana) in Mkhuze Game Reserve, South AfricaAFRICAN JOURNAL OF ECOLOGY, Issue 1 2010Angela M. White Abstract The reintroduction of African elephants into fenced game reserves throughout South Africa has presented managers with several challenges. Although elephants are a natural part of southern African ecosystems, their confinement to fenced protected areas in South Africa has exacerbated their potential to impact their habitats negatively. However, many studies investigating the impact of elephants have failed to control for the effects of other browsers on the vegetative community. In this study, we used location data on an elephant herd to delineate high-use and low-use areas. This paired design allowed us to minimize confounding factors that could explain differences in the structure, diversity and utilization of woody species. We found little evidence to suggest elephant-mediated change in, or selection for, the structure or diversity of woody species; however, our results suggest that elephants may be altering the composition of species by preferentially using areas with higher canopy diversity and by enhancing sapling recruitment. Although stripping of bark was higher in high-use areas, there was no evidence of differential mortality of tree species. Therefore, in our study area, and over the current time scale, elephants are having a negligible impact on the vegetative community. Résumé La réintroduction d'éléphants africains dans des réserves de faune clôturées dans toute l'Afrique du Sud représente plusieurs défis pour les gestionnaires. Bien que les éléphants fassent naturellement partie des écosystèmes d'Afrique australe, leur confinement dans des aires protégées clôturées en Afrique du Sud a exacerbé leur capacité d'avoir des impacts négatifs sur leurs habitats. Pourtant, les nombreuses études qui ont recherché l'impact des éléphants ont omis de contrôler l'effet des autres herbivores sur la communauté végétale. Dans cette étude, nous avons utilisé des données sur la localisation des hardes d'éléphants pour délimiter les zones plus ou moins fréquentées. Cette étude couplée nous a permis de minimiser les facteurs prêtant à confusion qui pouvaient expliquer des différences de structure, de diversité et d'utilisation des espèces ligneuses. Nous avons trouvé peu de preuves qui auraient indiqué que les éléphants changeaient ou sélectionnaient la structure ou la diversité des espèces ligneuses; cependant, nos résultats suggèrent que les éléphants pourraient modifier la composition des espèces en choisissant de préférence les zones où la diversité de la canopée est plus élevée et en stimulant le recrutement de jeunes plants. Même si les arrachages d'écorces étaient plus nombreux dans les zones très fréquentées, il n'y avait aucune preuve d'une mortalité différentielle selon les espèces d'arbres. C'est pourquoi, dans l'aire où nous avons travaillé, et pour le moment, on peut dire que les éléphants n'ont qu'un impact négligeable sur la communauté végétale. [source] | |||||||||||||||||||||||||||||||||||||||||||