Abstract  Herbal medicines including Agrimonia pilosa Ledeb. (APL) have been traditionally used to treat inflammations including allergic disease as valuable medicinal properties. To investigate the attenuating ability of APL on inflammation, the NO release and ROS production, which play a key role in inflammatory and immune responses, was first tested using in vitro assay. The 80% ethanol extract of APL showed a significant activity to inhibit NO release and ROS production. In additional extracts from 80% ethanol extract of APL, n-butanol (BuOH) extract displayed the most potent anti-inflammatory effects based on in vitro assay. The extract also significantly reduced nitric oxide in lipopolysaccharide-activated RAW 264.7 macrophage cells (p < 0.05), and suppressed the nitric oxide synthase (iNOS) expression, whereas the extract showed no inhibitory effect on cyclooxygenase-2 (COX-2) expression, suggesting that the BuOH extract of APL could reduce the NO production through suppression of iNOS, but not COX-2. The BuOH extract also showed a significant effect in a carrageenan-induced rat paw edema in vivo model, consistent with our in vitro results. Our findings suggest that the BuOH extract of APL shows a potential anti-inflammatory activity, substantiating its traditional use in medicine.

Abstract  The purpose of this article is to briefly review the published literature on the developmental neurotoxic effects, including potential mechanisms, of four butanols: n-butanol, sec-butanol, tert-butanol, isobutanol, and identify data gaps and research needs for evaluation of human health risks in this area. Exposure potential to these four butanols is considerable given the high production volume (>1billionlb) of n- and tert-butanol and moderate production volumes (100-500millionlb) of sec- and isobutanol. With the impetus to derive cleaner gasoline blends, butanols are being considered for use as fuel oxygenates. Notable signs of neurotoxicity and developmental neurotoxicity have been observed in some studies where laboratory animals (rodents) were gestationally exposed to n- or tert-butanol. Mechanistic data relevant to the observed developmental neurotoxicity endpoints were also reviewed to hypothesize potential mechanisms associated with the developmental neurotoxicity outcome. Data from the related and highly characterized alcohol, ethanol, were included to examine consistencies between this compound and the four butanols. It is widely known that alcohols, including butanols, interact with several ion channels and modulate the function of these targets following both acute and chronic exposures. In addition, n- and sec-butanol have been demonstrated to inhibit fetal rat brain astroglial cell proliferation. Further, rat pups exposed to n-butanol in utero were also reported to have significant increases in brain levels of dopamine and serotonin, but decreases in serotonin levels were noted with gestational exposure to tert-butanol. tert-Butanol was reported to inhibit muscarinic receptor-stimulated phosphoinositide metabolism which has been hypothesized to be a possible target for the neurotoxic effects of ethanol during brain development. The mechanistic data for the butanols support developmental neurotoxicity that has been observed in some of the rodent studies. However, careful studies evaluating the neurobehavior of developing pups in sensitive strains, as well as characterizing the plausible mechanisms involved, need to be conducted in order to further elucidate the neurodevelopmental effects of butanols for risk evaluation.

Abstract  Here we present experimental data of different properties for a set of binary mixtures composed of water or alkanols (methanol to butanol) with an ionic liquid (IL), butylpyridinium tetrafluoroborate [bpy][BF(4)]. Solubility data (x(IL),T) are presented for each of the mixtures, including water, which is found to have a small interval of compositions in IL, x(IL), with immiscibility. In each case, the upper critical solubility temperature (UCST) is determined and a correlation was observed between the UCST and the nature of the compounds in the mixtures. Miscibility curves establish the composition and temperature intervals where thermodynamic properties of the mixtures, such as enthalpies H(m)(E) and volumes V(m)(E), can be determined. Hence, at 298.15 and 318.15 K these can only be found with the first four alkanols. All mixing properties are correlated with a suitable equation ξ (x(IL),T,Y(m)(E) = 0. An analysis on the influence of the temperature in the properties is shown, likewise a comparison between the results obtained here and those of analogous mixtures, discussing the position of the -CH(3) group in the pyridinic ring. The (1)H NMR spectra are determined to analyze the molecular interactions present, especially those due to hydrogen bonds. Additional information about the molecular interactions and their influence on the mixing properties is obtained by quantum chemistry calculations.

Abstract  TLC profiles of aminolipids extracted from phytopathogenic and non-pathogenic bacteria with chloro-form-methanol-0.3%NaCl (2:1:0.2, v/v/v) or 2-propanol are useful for discrimination of bacteria. For many bacteria, each TLC profile is genus or species specific and highly reproducible. For most gram-negative bacteria, the uppermost spot (Up) appeared at ca. R sub(f) 0.7 on the chromatograms developed with chloroform-methanol-0.2% CaCl sub(2) times 2H sub(2)O (65:35:8, v/v/v). This spot was absent on the chromatograms of gram-positive bacteria, Clavibacter michiganensis. The profiles of Agrobacterium spp. and Rhizobium spp. were different from other gram-negative bacteria with the uppermost spots at ca. R sub(f) 0.75. For the case of Agrobacterium spp., the chromatograms of the strains belonging to the same biovar were identical. Distinct differences were found among the profiles of Agrobacterium biovar 1, A. biovar 2, A. biovar 3 and A. rubi. The profiles of Rhizobium spp., except for R. tropici, and their relatives such as Bradyrhizobium, Mesorhizo-bium and Sinorhizobium spp. were quite simple and different from those of Agrobacterium spp. For the case of Burkholderia species, except for B. andropogonis, three spots (designated as S1, S2, S3) appeared under the uppermost spot (Up) and their profiles were species specific for several species such as B. plantarii and B. caryophylli. On the chromatogram of B. andropogonis, the S1 spot (non-phosphorous) was absent and the S3 spot was faint. The profiles of 96 Ralstonia solanacearum strains from various sources were identical. For the case of Erwinia carotovora an intensive benchmark spot appeared at R sub(f) 0.64 but this spot was absent on the chromatograms of pathovars of E. chrysanthemi and E. herbicola. Clear diversity in profiles was observed between Xanthomonas campestris and X. oryzae. The profile of pathovars of Pseudomonas syringae were identical and simple. Substitution of chloroform solvent systems with less hazardous organic solvents was tested. 2-propanol for the lipid extraction and 1-butanol-acetic acid-water (3:1:1 and 5:3:1, v/v/v) for the developing solvents were usable, though development with the butanol systems was highly time-consuming.

Abstract  UNLABELLED: ETHNOPHARMACOLOGICAL IMPORTANCE: Many Bauhinia species, including those indigenous to South Africa, are used in traditional medicine across the world for treating ailments such as gastrointestinal tract (GIT) disorders, diabetes, infectious diseases and inflammation.

AIMS: Several relevant aspects of different fractions of leaf extracts of Bauhinia bowkeri (BAB), Bauhinia galpinii (BAG), Bauhinia petersiana (BAP), and Bauhinia variegata (BAV) used in South African traditional medicine to alleviate diarrhoea related symptoms were evaluated.

MATERIALS AND METHODS: The antioxidative activities of the extracts were determined using the 2, 2-diphenyl-1-picrylhydrazyl (DPPH), 2, 2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid (ABTS(+)) radical scavenging and ferric reducing antioxidant power (FRAP) methods. In vitro antimicrobial activities of the extracts were determined against bacterial strains (Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli and Enterococcus faecalis) and clinical isolates of the opportunistic fungal strains (Aspergillus fumigatus, Candida albicans, and Cryptococcus neoformans) using a serial dilution microplate method. The polyphenolic contents were quantified using standard methods, and anti-inflammatory activities of the crude extracts were determined using the cyclooxygenase and soybean 15-lipoxygenase enzyme inhibitory assays. The safety of the extracts was evaluated by determining the cytotoxicity against Vero cell lines.

RESULTS: The acidified 70% acetone crude extract and their fractions had good antiradical potency against the DPPH and ABTS radicals. The methanol soluble portions of the butanol fractions were more potent (EC(50) ranges from 0.64 ± 0.05 to 1.51 ± 0.07 and 0.88 ± 0.18 to 1.49 ± 0.09 μg/ml against DPPH and ABTS radical respectively) compared to the standard, trolox and ascorbic acid (EC(50) ranges from 1.47 ± 0.24 to 1.70 ± 0.27 μg/ml) for both DPPH and ABTS. The crude extracts contained variable quantities of phenolic content. The crude extracts and their fractions had weak to good antimicrobial activities, inhibiting the growth of the organisms at concentrations ranging from 39 to 2500 μg/ml. The BAG crude extract and its fractions were the most active against the fungi (MICs ranging from 39 to 625 μg/ml) while the BAB extract and its fractions were the least active with the MICs ranging between 39 and 2500 μg/ml. Aspergillus fumigatus was the least susceptible fungus while Cryptococcus neoformans was the most susceptible. The phenolic-rich crude extracts of BAB, BAG, and BAP had moderate to good dose-dependent cyclooxygenase-1 enzyme inhibitory activity with inhibitions between 22.8% and 71.4%. The extracts were however, inactive against cyclooxygenase-2. The extracts had some level of cytotoxicity towards Vero cell lines, reducing cell viability to less than 10% at concentrations more than 50 μg/ml.

CONCLUSION: The biological activities observed in Bauhinia species provide a scientific basis for the use of the plants in traditional medicines to treat diseases with multi-factorial pathogenesis such as diarrhoea, with each aspect of activity contributing to the ultimate therapeutic benefit of the plants. However, the use of the phenolic-rich extracts of these plants to treat diarrhoea or any other ailments in traditional medicine needs to be monitored closely because of potential toxic effects and selective inhibition of COX-1 with the associated GIT injury.

Abstract  Using a laboratory-scale mixed reactor, the performance of alumina in degrading 2,4-Dichlorophenoxyacetic acid with ozone in the presence of tert-butyl alcohol radical scavenger was studied. The operating variables investigated were the dose of alumina catalyst and solution pH. Results showed that using ozone and alumina leads to a significant increase in 2,4-D removal in comparison to non-catalytic ozonation and adsorption processes. The observed reaction rate constants (k(obs)) for 2,4-D during ozonation were found to increase linearly with increasing catalyst dose. At pH 5, the k(obs) value increased from 19.3 to 26 M(-1) s(-1) and 67 M(-1) s(-1) when varying the alumina dose from 1 to 2 and 4 g L(-1), respectively. As pH was increased, higher reaction rates were observed for both non-catalytic ozonation and catalytic ozonation processes. Thus, at pH 3 and using a catalyst dose of 8 g L(-1), the k(obs) values for non-catalytic ozonation and catalytic ozonation processes were 3.4 and 58.9 M(-1) s(-1), respectively, whereas at pH 5 reaction rate constants of 6.5 and 128.5 M(-1) s(-1) were observed, respectively. Analysis of total organic carbon suggested that catalytic ozonation with alumina achieved a considerable level of mineralization of 2,4-D. Adsorption of 2,4-D on alumina was found to play an important role in the catalytic ozonation process.

Abstract  A methyl tert-butyl ether (MTBE) / tert-butyl alcohol (TBA) plume originating from a gasoline spill in late 1994 at Vandenberg Air Force Base (VAFB) persisted for over 15 years within 200 feet of the original spill source. The plume persisted until 2010 despite excavation of the tanks and piping within months after the spill and excavations of additional contaminated sediments from the source area in 2007 and 2008. The probable history of MTBE concentrations along the plume centerline at its source was estimated using a wide variety of available information, including published details about the original spill, excavations and monitoring by VAFB consultants, and our own research data. Two-dimensional reactive transport simulations of MTBE along the plume centerline were conducted for a 20-year period following the spill. These analyses suggest that MTBE diffused from the thin anaerobic aquifer into the adjacent anaerobic silts and transformed to TBA in both aquifer and silt layers. The model reproduces the observation that after 2004 TBA was the dominant solute, diffusing back out of the silts into the aquifer and sustaining plume concentrations much longer than would have been the case in the absence of such diffusive exchange. Simulations also suggest that aerobic degradation of MTBE or TBA at the water table in the overlying silt layer significantly affected concentrations of MTBE and TBA by limiting the chemical mass available for back diffusion to the aquifer.

Abstract  The degradation of tetracycline by ozone was investigated in this paper. In the laboratory scale experiments, the effect of major parameters, including pH, gas flow rate, gaseous ozone concentration, hydrogen peroxide concentration and hydroxyl radical scavenger (tert-butyl alcohol) on the degradation of tetracycline was studied. A pseudo-first order kinetic model was used to simulate the experimental results. The results indicated that the tetracycline degradation rate increased with pH, gaseous ozone concentration and gas flow rate. The addition of hydrogen peroxide or hydroxyl radical scavenger had little effect on tetracycline removal, indicating that the direct oxidation of tetracycline by ozone was dominant process and the radical contribution to the tetracycline oxidation could be neglected. The main intermediates were separated and identified as well as the simple degradation pathway of tetracycline was proposed. The COD removal reached to 35% after 90 min reaction. The acute toxicity experiments illustrated that the Daphnia magna mortality reached the maximum after 25 min ozonation and then decreased to zero after 90 min ozonation.

Abstract  To overcome the disadvantages of microemulsion and nanoprecipitation methods to produce protein-containing nanoparticles, a novel bottom-up process was developed to produce nanoparticles containing the model protein lysozyme. The nanoparticles were generated by freeze-drying a solution of lysozyme, lecithin and lactose in tert-butyl alcohol (TBA)/water co-solvent system and washing off excess lecithin in lyophilizate by centrifugation. Formulation parameters such as lecithin concentration in organic phase, water content in TBA/water co-solvent, and lactose concentration in water were optimized so as to obtain desired nanoparticles with retention of the bioactivity of lysozyme. Based on the results, 24.0% (w/v) of lecithin, 37.5% (v/v) of water content, and 0.56% (w/v) of lactose concentration were selected to generate spherical nanoparticles with approximately 200 nm in mean size, 0.1 in polydispersity index (PI), and 99% retained bioactivity of lysozyme. These nanoparticles rinsed with ethanol containing dipalmitoylphosphatidylcholine (DPPC), Span 85 or oleic acid (3%, w/v) could readily be dispersed in HFA 134a to form a stable suspension with good redispersibility and 98% retained bioactivity of lysozyme. The study indicates there is a potential to produce pressed metered dose inhaler (pMDI) formulations containing therapeutic protein and peptide nanoparticles.

Abstract  In the catalysis of S(N)2 fluorination reactions, the ionic liquid anion plays a key role as a Lewis base by binding to the counterion Cs(+) and thereby reducing the retarding Coulombic influence of Cs(+) on the nucleophile F(-). The reaction rates also depend critically on the structures of ionic liquid cation, for example, n-butyl imidazolium gives no S(N)2 products, whereas n-butylmethyl imidazolium works well. The origin of the observed phenomenal synergetic effects by the ionic liquid [mim-(t)OH][OMs], in which t-butanol is bonded covalently to the cation [mim], is that the t-butanol moiety binds to the leaving group of the substrate, moderating the retarding interactions between the acidic hydrogen and F(-). This work is a significant step toward designing and engineering solvents for promoting specific chemical reactions.

Abstract  Ethyl t-butyl ether (ETBE) is a motor fuel oxygenate used in reformulated gasoline. Knowledge of developmental and reproductive toxicity potential of ETBE is critical for making informed decisions about acceptance and regulations. This review discusses toxicology studies providing information about effects on reproduction and the conceptus. Seven GLP-compliant studies following widely accepted protocols have focused specifically on developmental and reproductive toxicity (DART) in rats and rabbits exposed to ETBE by gavage with doses up to 1,000 mg/kg body weight/day, the limit specified in standardized test guidelines. Other repeat-dose general toxicology studies have administered ETBE to rodents for up to 180 days, and included reproductive organ weights, histology, or other indications of reproductive system structure or function. DART potential of the main ETBE metabolite t-butyl alcohol and class-related MTBE has also been studied. More GLP-compliant studies exist for evaluating ETBE using well-established, currently recommended protocols than are available for many other chemicals used today. The database for determining ETBE DART potential is adequate, although not all study details are currently easily accessible for peer-review. ETBE does not appear to be selectively toxic to reproduction or embryofetal development in the absence of other manifestations of general toxicity. Studies using recommended methods for sample preservation and analysis have shown no targeted effect on the reproductive system. No embryofetal effects were observed in rabbits. Early postnatal rat pup deaths show no clear dose-response and have largely been attributed to total litter losses with accompanying evidence of maternal neglect or frank maternal morbidity.

Abstract  Advanced smoke generation systems, such as the Borgwaldt RM20S(®) smoking machine used in combination with the BAT exposure chamber, allow for the generation, dilution and delivery of fresh cigarette smoke to cell or tissue cultures for in vitro cell culture analyses. Recently, our group confirmed that the Borgwaldt RM20S(®) is a reliable tool to generate and deliver repeatable and reproducible exposure concentrations of whole smoke to in vitro cultures. However, the relationship between dose and diluted smoke components found within the exposure chamber has not been characterized. The current study focused on the development of a headspace stir bar sorptive extraction (HSSE) method to chemically characterize some of the vapor phase components of cigarette smoke generated by the Borgwaldt RM20S(®) and collected within a cell culture exposure chamber. The method was based on passive sampling within the chamber by HSSE using a Twister™ stir bar. Following exposure, sorbed analytes were recovered using a thermal desorption unit and a cooled injection system coupled to gas chromatograph/mass spectrometry for identification and quantification. Using the HSSE method, sixteen compounds were identified. The desorption parameters were assessed using ten reference compounds and the following conditions led to the maximal response: desorption temperature of 200°C for 2 min with cryofocussing temperature of -75°C. During transfer of the stir bars to the thermal desorption system, significant losses of analytes were observed as a function of time; therefore, the exposure-to-desorption time interval was kept at the minimum of 10±0.5 min. Repeatability of the HSSE method was assessed by monitoring five reference compounds present in the vapor phase (10.1-12.9% RSD) and n-butyl acetate, the internal standard (18.5% RSD). The smoke dilution precision was found to be 17.2, 6.2 and 11.7% RSD for exposure concentrations of 1, 2 and 5% (v/v) cigarette vapor phase in air, respectively. A linear response of analyte abundance was observed as a function of dilution. Extrapolation to 100% (v/v) cigarette vapor phase, i.e., undiluted smoke, gave yields for the five compounds ranging from 6 to 450 ng for 10 min exposure.

Abstract  Developments in the area of packed columns, particularly structured packed columns, are ongoing, specifically in the area of liquid-liquid extractions. Accurate predictions of mass transfer coefficients lead to more accurate design of columns. In the present study, mass transfer coefficients were measured experimentally for packed columns of different heights to study the effect of packing height and specific area. Two experimental pilot regular packed extraction columns were examined using toluene/acetic acid/water and n-butyl acetate/acetic acid/water systems. Based on the results, a novel model for prediction of effective diffusivity has been proposed that is a function of column height and specific area. The mass transfer coefficients obtained by this prediction were compared with other models. The results of this new model are in good agreement with the experimental data. Therefore, this new model can be used to design better regular packed columns.

Abstract  SAN/BMIPF6 nanofibers were fabricated by an electrospinning process and used as chemiresistors for sensing alcohol vapours. A hydrophobic and air-stable ionic liquid, BMIPF6, was used to impart electrical conductivity to insulating SAN nanofibers. The effects of BMIPF6 addition on the morphology of the nanofibers were explained in terms of surface tension, viscosity and conductivity. After exposing the SAN/BMIPF6 nanofibers collected on an interdigitated electrode to alcohol vapours (ethanol, 1-propanol and 1-butanol), the resistance of the nanofibers decreased due to adsorption of alcohol molecules. The electrospun SAN/BMIPF6 nanofibers sensor exhibited good sensitivity and reproducibility.

Abstract  Organic bistable devices (OBDs) based on [6,6]-phenyl-C85 butyric acid methyl ester ([84]PCBM) embedded in a polymethyl methacrylate (PMMA) layer were fabricated by using a simple spin-coating technique. Atomic force microscope images showed that the surface roughness of the [84] PCBM: PMMA composite layer was uniform. Current density-voltage curves for the memory device showed a current bistability. The maximum ON/OFF ratio of the current bistability of the OBDs was as large as 10(3). Write-read-erase-read characteristics showed OBDs with rewriteable nonvolatile memories, and the retention time of the OBDs was about 10(4) s. The ON state and the OFF state for 20 randomly-chosen cells demonstrated the high reproducibility of the fabricated OBDs. (C) 2011 Elsevier B.V. All rights reserved.

Abstract  Herein, we investigate the dissolution behavior of 193-nm chemically amplified resist in different organic solvents at a mechanistic level. We previously reported the effect of solvent developers on the negative tone development (NTD) process in both dry and immersion lithography, and demonstrated various resist performance parameters such as photospeed, critical dimension uniformity, and dissolution rate contrast are strongly affected by chemical nature of the organic developer. We further pursued the investigation by examining the dependence of resist dissolution behavior on their solubility properties using Hansen Solubility Parameter (HSP). The effects of monomer structure, and resist composition, and the effects of different developer chemistry on dissolution behaviors were evaluated by using laser interferometry and quartz crystal microbalance. We have found that dissolution behaviors of methacrylate based resists are significantly different in different organic solvent developers such as OSD (TM)-1000 Developer* and n-butyl acetate (nBA), affecting their resist performance. This study reveals that understanding the resist dissolution behavior helps to design robust NTD materials for higher resolution imaging.

Abstract  Previous results have shown that both nitric oxide (NO) and hydrogen peroxide (H(2)O(2)) play crucial roles in the promotion of adventitious root development in explants of marigold (Tagetes erecta L.). In this study, the involvement of NO and H(2)O(2) in indole-3-butyric acid (IBA)-induced adventitious root development in marigold explants, and the order of action of these molecules in the signal transduction pathway were investigated. The results indicated that, like NO and H(2)O(2), IBA-induced adventitious rooting occurred in a dose-dependent manner. Two parameters of root growth in explants treated simultaneously with IBA and H(2)O(2) were significantly higher than those in explants treated with IBA or H(2)O(2) alone, suggesting that IBA and H(2)O(2) may act synergistically to mediate adventitious rooting. NO and H(2)O(2) were pre-requisites for the adventitious rooting induced by IBA. Moreover, treatment with IBA enhanced the endogenous levels of NO and H(2)O(2) in explants, indicating that the induction of adventitious roots by IBA occurred through enhancing the levels of NO and H(2)O(2). NO and H(2)O(2) may be downstream signal molecules in the auxin signalling cascade, and NO may be involved as an upstream signalling molecule for H(2)O(2) production.

Abstract  Rapid chromatographic procedures for analytical quality control of pharmaceutical preparations containing antihistamine drugs, alone or together with other kind of compounds are proposed. The method uses C18 stationary phases and micellar mobile phases of cetyltrimethylammonium bromide (CTAB) with either 1-propanol or 1-butanol as organic modifier. The proposed procedures allow the determination of the antihistamines: brompheniramine, chlorcyclizine, chlorpheniramine, diphenhydramine, doxylamine, flunarizine, hydroxyzine, promethazine, terfenadine, tripelennamine and triprolidine, in addition to caffeine, dextromethorphan, guaifenesin, paracetamol and pyridoxine in different pharmaceutical presentations (tablets, capsules, suppositories, syrups and ointments). The methods require minimum handling sample and are rapid (between 3 and 12 min at 1 mLmin(-1) flow rate) and reproducible (R.S.D. values<5%). Limits of detection are lower than 1 microgmL(-1) and the recoveries of the analytes in the pharmaceutical preparations are in the range 100+/-10%.

Abstract  This paper describes the development and validation of a microemulsion liquid chromatography (MELC) method for simultaneous determination of perindopril tert-butylamine and its impurities in bulk active substances and the pharmaceutical dosage form of tablets. An appropriate resolution with reasonable retention times was obtained for a microemulsion containing 0.24% (w/v) butyl acetate, 0.30% (w/v) ethyl acetate, 2% (w/v) sodium dodecyl sulfate, 7.75% (w/v) n-butanol, and 20.0 mM potassium dihydrogen phosphate, the pH of which was adjusted to 3.70 with 85% orthophosphoric acid. Separations were performed on a Nucleosil 120-5 butyl modified (C4), 250 x 4 mm, 5 microm particle size silica column at 40 degrees C, with a mobile phase flow rate of 1.25 mL/min. UV detection was performed at 254 nm. The established method was subjected to method validation, and required validation parameters were defined. Robustness testing, an important part of method validation, was performed as well. Since robustness validation can be conducted using different experimental designs, the Plackett-Burman design was applied due to its possibility of testing many factors at the same time. The validated MELC method was found to be suitable for the simultaneous determination of perindopril tert-butylamine and its impurities in pharmaceuticals.

Abstract  Recently, the association term resulting from SAFT theory has been implemented in the traditional framework of empirical multiparameter equations of state to enable the description of fluids with strong association effects in the gas phase. Here, as an exemplary application, we present an accurate EoS for acetic acid, which is known to be a strongly associating fluid. In the present model, the SAFT term is combined with a conventional form; the latter roughly accounts for all effects not ascribable to association. The obtained equation represents experimental data generally within the scatter of the data. However, due to the limited quality of the available experimental data, accuracy requirements formulated for accurate technical equations of state cannot be met over all the validity ranges of the equation [1-3]. The model is able to foresee the anomalous trends of the heat capacity in vapor phase that are typical of strongly associating fluids. More accurate equations can be developed within the mathematical framework of the present model, provided supplementary data become available. Heat capacity data in the vapor phase at any density are vital for the tuning of the SAFT term. Some data of this kind are available for acetic acid 139,401, but they are generally lacking for other carboxylic acids such as formic, propanoic or butanoic acid. Additional regularly distributed caloric data in the liquid phase would also be very useful for the development of further improved equations of state. The experimental data set available for thermodynamic data of acetic acid scatters very strongly beyond 520 K, and thermal decomposition is very likely to be responsible for this. Since the critical temperature is about 590K, no reliable data are available for the extended critical region, nor for supercritical states. Measurements of polar and associating fluids in the vapor phase are in any case very sensitive to decomposition effects and adsorption effects. Another issue concerning carboxylic acids is that at low temperatures vapor pressures become very small. At these conditions measurements are hardly possible in the gas phase because of the very low density. Nevertheless strong associative effects are present even at such low densities, as it will be shown in this paper. Purely empirical terms cannot describe these effects due to the lack of accurate data and due to the practical limitations of common virial expansions. Thus, the inclusion of a physical term in multiparameter equations of state seems to be the most promising way to reach a meaningful thermodynamic representation of strongly associating fluids. The adjustable parameters of the association term are tied to measurable physical quantities like the enthalpy and entropy change of the association reaction, so that a generalization to fluids pertaining to the same family can be easily achieved. (c) 2011 Elsevier B.V. All rights reserved.

Abstract  Five different processes were investigated to produce acetone-butanol-ethanol (ABE) from wheat straw WS) by Clostridium beijerinckii P260. The five processes were fermentation of pretreated WS (Process I), separate hydrolysis and fermentation of WS to ABE without removing sediments (Process II), simultaneous hydrolysis and fermentation of WS without agitation (Process III), simultaneous hydrolysis and fermentation with additional sugar supplementation (Process M, and simultaneous hydrolysis and fermentation with agitation by gas stripping (Process V). During the five processes, 9.36, 13.12, 11.93, 17.92, and 21.42 g L-1 ABE was produced, respectively. Processes I-V resulted in productivities of 0.19, 0.14, 0.27, 0.19, and 0.31 g L-1 h(-1), respectively. it should be noted that Process V resulted in the highest productivity (0.31 g L-1 h(-1)). In the control experiment (using glucose), an ABE productivity of 0.30 g L-1 h(-1) was achieved. These results suggest that simultaneous hydrolysis of WS to sugars and. fermentation to butanol/ABE is an attractive option as compared with more expensive glucose to ABE fermentation. Further development of enzymes for WS hydrolysis with optimum characteristics similar to fermentation would make conversion of WS to butanol/ABE even more attractive. Published by Elsevier Ltd.

Abstract  The estimation of PV-modules lifetime facilitates the further development and helps to lower risks for producers and investors. One base for this extensive testing work is the knowledge of the degradation kinetics of encapsulating polymer materials. Besides ethylen-vinylacetate copolymer (EVA), which is the prevalent material for encapsulation, new materials like Poly-Vinyl-Butyral (PVB), and thermoplastic Poly-Urethan (TPU) become available and need the assessment of their properties and the durability impact. In this context is it very important to identify the extent of degradation caused by different parameters in order to identify the determining factor of polymer degradation as well as potential interactions between different degradation processes. To simulate long time degeneration processes accelerated aging under damp-heat and high-UV conditions was performed on different EVA, TPU, and PVB samples. In this paper we report first results on measuring fluorescence spectra from different encapsulation materials after accelerated ageing in dependence on time and aging procedure. Our investigations clearly demonstrate that it is possible to follow damp-heat and UV induced aging processes of different polymers used in PV-modules as encapsulation materials by luminescence detection.