bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ruthenium‐Catalyzed Hydrogenation of Carbon Dioxide to Formic Acid in Alcohols
Authors: Ng Siu Man , Yin Chuanqi , Yeung Chi Hung , Chan Tak Chung , Lau Chak Po 
Published: April 2004

AbstractCatalytic hydrogenation of CO2 to formic acid with the (solvento)metal hydride complex, TpRu(PPh3)(CH3CN)H [Tp = hydrotris(pyrazolyl)borate], in various alcohols was studied. High‐pressure NMR monitoring of the catalytic reaction in non‐acidic methanol shows that the observable intermediate is a formate complex resulting from CO2 insertion into the Ru−H bond and is stabilized by the hydrogen‐bonding interaction between the formato ligand and a methanol molecule. However, in the case of the acidic alcohol, CF3CH2OH, the observable intermediates are [TpRu(PPh3)(CH3CN)2]+CF3CH2O− and the alkyl carbonate complex, TpRu(PPh3)(η2‐O2COCH2CF3), which are formed by the reaction of CO2 with the alkoxide species, TpRu(PPh3)(CH3CN)(OCH2CF3), generated by a very facile reaction between TpRu(PPh3)(CH3CN)H and CF3CH2OH. We propose that the productive catalytic cycles of the reactions conducted in a variety of alcohols are similar to the one we formulated for the catalytic hydrogenation of CO2 in hydrous THF. The formic acid is produced by the transfer of a hydride and a proton from the transient alcohol hydride intermediate, TpRu(PPh3)(ROH)H, to an approaching CO2 molecule. The activity of TpRu(PPh3)(CH3CN)H is higher in CF3CH2OH than in methanol and other non‐acidic alcohols and it is probably due to the enhanced electrophilicity of the carbon atom of CO2, which results from the strong interaction between the proton of the highly acidic alcohol in TpRu(PPh3)(CF3CH2OH)H and an oxygen atom of CO2. The electrophilic carbon atom of CO2 could in turn abstract the hydride from Ru−H in a more facile manner. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
A Rational Self‐Sacrificing Template Route to β‐Bi2O3 Nanotube Arrays
Authors: Yang Baojun , Mo Maosong , Hu Hanmei , Li Cun , Yang Xiaogang , Li Qiaowei , Qian Yitai 
Published: April 2004

AbstractArrayed β‐Bi2O3 nanotubes (NTs) were synthesized for the first time through a rational “self‐sacrificing template” route, simply by oxidizing the precursor metallic bismuth NT arrays in air at 200−220 °C for 14−18 h. XRD, TEM, and HRTEM characterizations show that the prepared β‐Bi2O3 samples are all phase pure and the β‐Bi2O3 NTs have uniform diameters of approximately 3−6 nm and lengths up to several micrometers. The optical absorption and photoluminescence (PL) characteristics of the prepared samples were investigated. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Treating process wastewater employing vacuum distillation using mechanical vapor recompression
Authors: McCabe Derald L. , Vivona M. A. (Tony) 
Published: April 2004

AbstractProcess wastewater has been successfully treated using an enhanced variable vacuum distillation system (WDS). The removal of contaminants is achieved initially by degassing the liquid under an intense vacuum which removes the volatile organic compounds. The resulting liquid is then distilled under a vacuum using mechanical vapor recompression. The system was invented by Derald McCabe.This innovative treatment system removes virtually all of the contaminants, such as TSS, TDS, BOD5, COD, heavy metals and mineral compounds. The resultant aqueous portion normally returns to a neutral pH. Due to the unique system operation, scaling problems (often encountered in conventional distillation) have not been detected in this system.The I'VDS is extremely energy efficient because the heat for distillation is generated and recycled mechanically. Using electricity as the energy source, the approximate operating cost, based on $0.05 KWH, may vary from $0.005 to $0.01 per gallon depending on the size and capacity of the equipment.Based on applications in waste streams performed to‐date, the WDS process has yielded a distilled water stream and the concentrated solids has been used as a byproduct or as a concentrated non‐dischargeable waste for disposal.
On the use of biosurfactants for the removal of heavy metals from oil‐contaminated soil
Authors: Mulligan Catherine N. , Yong Raymond N. , Gibbs Bernard F. 
Published: April 2004

AbstractThe feasibility of using biodegradable biosurfactants to remove heavy metals from an oil‐contaminated soil was evaluated by batch washes with surfactin, a rhamnolipid and a sophorolipid. The soil contained 890 mg/kg of zinc and 420 mg/kg of copper with a 12.6% oil and grease content. Highest levels of zinc removal were obtained using 12% rhamnolipid (19.5% of the zinc) and 4% sophorolipid/0.7% HCl (15.8% of the zinc). Highest copper removal rates were achieved (greater than 25%) with 12% rhamnolipid or with 2% rhamnolipid /!% NaOH or 0.25% surfactin/1% NaOH. A series of five batch washes removed 70% of the copper with 0.1% surfactin/1% NaOH ivhile 4% sophorolipid/0.7% HCl was able to remove 100% of the zinc. Sequential extraction procedures showed that the carbonate and oxide fractions accounted for over 90% of the zinc present in the soil and the organic fraction in the soil constituted over 70% of the copper. Sequential extraction of the soil after washing with the surfactin or rhamnolipid (both with 1% NaOH) indicated that these surfactants could remove the organically‐bound copper and that the sophorolipid with acid could remove the carbonate and oxide ‐bound zinc. In conclusion, the results clearly indicated the feasibility of removing the metals with the anionic biosurfactants tested even though the exchangeable metal fractions were very low.
Pollution prevention in vacuum processes
Authors: Mulholland Kenneth L. , Dyer James A. 
Published: April 2004

AbstractThe gaseous emissions from vacuum systems often contain volatile organic compounds (VOCs) ‐ one or more of which may be regulated as Hazardous Air Pollutants (HAPs) under the 1990 Clean Air Act Amendments. Typically, regulated emission sources will require greater than 98% control of using an end‐of‐pipe abatement or recovery technology. VOCs from vacuum generation are expensive to control and increase the investment and operating cost of the vacuum system. When noncondensibles or inserts are present, the amount of VOCs emitted to the environment will increase dramatically. This article discusses approaches which process and project engineers can apply to reduce or eliminate vacuum system emissions. Actual case histories are included which reflect the range of solutions that are being applied.
Vapor‐phase bioreactors: Avoiding problems through better design and operation
Authors: Kinney K. A. , Loehr R. C. , Corsi R. L. 
Published: April 2004

AbstractVapor‐phase bioreactors are an efficient method to treat air contaminated with volatile organic compounds. To ensure stable long term performance, several design and operating factors must be considered. Common problems include nutrient limitations, biomass clogging, and inactivation, low moisture content and reductions in pH. Based on several bioreactor studies, the underlying cause of each of these problems is identified, monitoring requirements are outlined and a range of appropriate response actions are presented. These solutions range from modification of bioreactor design and operation to the use of alternative types of microorganisms such as fungi.
Life cycle engineering case study: Automobile fender designs
Authors: Saur Konrad , Fava James A. , Spatari Sabrina 
Published: April 2004

AbstractBeginning with the goal and scope definition five different fender designs using steel, aluminum, PP/EPDM, PC/PBT and PPO/PA are described and the boundary conditions set. This exemplary case study demonstrates the general approach and beneficial uses of life cycle assessment and life cycle engineering. The inventory of the fenders shows that the steel design has advantages in terms of lower energy consumption during production. However, when the utilization phase of the fenders is considered, the overall energy consumption of the PP/EPDM fender is smaller due to the light weight of the this polymer design.Concerning the life cycle impact assessment (LCIA), the global warming potential of the PP/EPDM design is the smallest of all the fender materials even during the production of the fenders. The inventory analysis shows that the utilization phase of automotive parts is dominated by fuel consumption and related emissions like CO2. Nevertheless the LCIA shows that some impacts are mainly determined in the production phase. For example, the global warming potential of nitrous oxide (N2O) released during PPO/PA material production cannot be compensated for by the lower energy demand (and also lower CO2 emissions) during the utilization phase.Economic considerations are also discussed. As a parameter, the cost of parts was chosen. Parts costs depend on material costs, labor costs and other variable costs. In addition, the fixed costs for machines and tools were considered. Steel fenders have the smallest production costs, followed by the PP/EPDM design.Finally, in an overall valuation of the compared fender designs the best design considering primary energy demand, global warming potential, and part costs was investigated. In terms of the specified criteria, the PP/EPDM fender is the best design, however, the results lead to a variety of different conclusions.
Baghouse system design based on economic optimization
Authors: Caputo Antonio C. , Pelagagge Pacifico M. 
Published: April 2004

AbstractIn this paper a method is described for using economic optimization in the design of baghouse systems. That is, for a given emission control problem, the total filtration surface area, the overall pressure drop, fabric material effects, and the cleaning cycle frequency, may all be evaluated simultaneously. In fact, as baghouse design parameters affect capital and operating expenses in interrelated and counteracting manners, a minimum total cost may be searched defining the best arrangement of dust collection devices. With this in mind, detailed cost functions have been developed with the aim of providing an overall economic model. As a result, a discounted total annual cost has been obtained that may be minimized by allowing for optimal baghouse characterization. Finally, in order to highlight the capabilities of the proposed methodology, some optimized solutions are also presented, which consider the economic impact of both bag materials and dust properties.
Extraction of metals from a contaminated sandy soil using citric acid
Authors: Bassi Raman , Prasher Shiv O. , Simpson B.K. 
Published: April 2004

AbstractTwenty‐four‐hour washing of a contaminated soil with 0.5 M citric acid reduced the levels of Cd, Cu, Zn, and Pb from 0.01, 0.04, 0.42, and 41.52 mg g‐1 to 0, 0.02, 0.18 and 5.21 mg g‐1, respectively. Extending the washing period beyond 24 hours did not influence the results significantly. Metal ions present in higher amounts were removed more easily. A column study was also conducted to compare metal leaching with surface and subsurface application of 0.3 M citric acid to 60 cm long soil columns packed with metal‐contaminated soil. Results indicated that the uniform distribution of citric acid, applied through the subirrigation system, resulted in a more efficient extraction of metal ions. The extraction of Zn and Pb from the columns with subsurface application of citric acid was, respectively, 38 and 27 times higher than from the columns with surface application of citric acid. After washing the contaminated soil with various citric acid concentrations, the metal‐rich wash solution was treated effectively using chitosan flakes.
Removal of zinc from rubber thread manufacturing industry wastewater using chemical precipitant/flocculant
Authors: Subbiah R.M. , Sastry C.A. , Agamuthu P. 
Published: April 2004

AbstractWastewater from the rubber thread manufacturing industry is acidic in nature with pH in the range of 3.8 to 4.4 and containing high concentrations of COD, BOD, Total‐N and zinc. The high BOD and COD ratio of the waste ‐ water (0.78 to 0.90) indicates that the rubber wastewater is biodegradable and can be treated effectively by an anaerobic digestion process commonly employed in this industry. However, because the wastewater contained high concentrations of zinc, 250 to 310 mg/L, which could inhibit the digestion process, it was pretreated by chemical precipitation/flocculation. A treatment process using a combination of sodium sulfide and polyelectrolyte LT 27 at concentrations of 800 and 5mg/L, respectively, is the most cost‐effective system for zinc removal from the wastewater. Zinc removal by sodium sulfide is not affected by pH. The optimum settling time was 60 min, whereas the optimum flocculation time was 20 min, and a speed of 20 rpm in a 110 mm diameter reactor gave the best results. The estimated cost of zinc removal using this method was RM1.04/m3 (US $0.26/m3) of wastewater discharged.
Desulfurization of syngas in a transport reactor
Authors: Gupta Raghubir P. , Turk Brian S. , Portzer Jeffrey W. , Cicero Daniel C. 
Published: April 2004

AbstractDuring gasification, sulfur present in carbonaceous materials is converted into reduced sulfur species, such as H2S and COS. These sulfur species are conventionally removed from syngas by catalytic hydrolysis of COS into H2S, followed by scrubbing of H2S with liquid‐phase amine systems. Amine‐based processes are subject to equipment corrosion, foaming, amine‐solution degradation, and evaporation, and require extensive wastewater treatment. As a result, this sulfur removal technology is complex, capitalintensive, and expensive. Furthermore, this conventional technology requires the syngas be cooled to nearly ambient temperatures, thus wasting valuable energy.New emerging technologies for sulfur removal from syngas use regenerable sorbents, primarily based on ZnO. Recent advances in sorbent technology allow sulfur species to be removed from syngas over a wide temperature range (260° to 760° C), making it an attractive alternative for a wide variety of applications, including power generation, chemical production, and fuel cells. This sorbent technology has advanced to the point that syngas desulfurization can be carried out in both fixed‐and fluidized‐bed reactors, depending upon process design needs. Additional applications of this technology in desulfurization of natural gas and removal of sulfur species from a syngas generated from gasification of black liquor were investigated.
American creosote site case study: Solidification/stabilization of dioxins, PCP, and creosote for $64 per cubic yard
Authors: Bates Edward R. , Akindele Femi , Sprinkle Don 
Published: April 2004

AbstractSolidification/Stabilization (S/S) is a low‐cost remedial technology that has been used extensively for decades to treat soil contaminated with metals on Super fund sites. Increasingly, it is being used with success to remediate sites that contain higher molecular weight organic compounds. This case study describes the development of S/S formations and their application to remediate the American Creosote Superfund Site in Jackson, Tennessee.The U.S. EPA National Risk Management Research Laboratory conducted successful treatability tests of innovative solidification/stabilization (S/S) formulations to treat soils contaminated with dioxins, pentachlorophenol (PCP), and creosote from four wood preserving sites. Formulations developed during these studies were successful in reducing the mobility (leaching) of contaminants of concern by 95% to 99%. For one of these sites, the American Creosote Superfund site in Jackson, Tennessee, the U.S. EPA, in cooperation with the State of Tennessee, conducted a successful remediation of 45,000 cubic yards during 1998 and 1999. The costs to excavate, treat, replace, and cap soil contaminated with dioxin, PCP, and creosote averaged $64 per cubic yard (about $40 ton). Formulations, design, operations, performance specifications, and costs are presented in this paper.
U.S. DOE integrated collaborative technology development program for CO2 separation and capture
Authors: Klara Scott M. , Srivastava Rameshwar D. 
Published: April 2004

AbstractElectric power generation represents one of the largest carbon dioxide (CO2) emitters in the United States. Roughly one‐third of all the United States' carbon emissions come from power plants. Since electricity generation is expected to grow, and fossil fuels will continue to be the dominant fuel source, power generation can be expected to provide even greater CO2 contributions in the future. Consequently, an important component of the United States Department of Energy's (DOE's) research and development program is dedicated to reducing CO2 emissions from power plants by developing technologies to capture CO2 for utilization and/or sequestration. A primary goal of this research is to develop technology options that dramatically lower the cost of eliminating CO2 from flue gas and other streams by use of either pre‐ or post‐combustion processes. This research is in its early stages, and is exploring a wide range of approaches, including membranes, improved CO2 sorbents, advanced scrubbing, oxyfuel combustors, formation of CO2 hydrates, and economic assessments. This paper presents an overview of the DOE research program in the area of CO2 separation and capture, while specifically addressing the status of research efforts related to promising pathways and potential technological breakthroughs.
A review of pressure‐driven membrane processes in wastewater treatment and drinking water production
Authors: Van Der Bruggen Bart , Vandecasteele Carlo , Van Gestel Tim , Doyen Wim , Leysen Roger 
Published: April 2004

AbstractIn pressure‐driven membrane processes (reverse osmosis, nanofiltration, ultrafiltration, and microfiltration) a pressure exerted on the solution at one side of the membrane serves as a driving force to separate it into a permeate and a retentate. The permeate is usually pure water, whereas the retentate is a concentrated solution that must be disposed of or treated by other methods. Membranes may be polymeric, organo‐mineral, ceramic, or metallic, and filtration techniques differ in pore size, from dense (no pores) to porous membranes. Depending on the type of technique, salts, small organic molecules, macromolecules, or particles can be retained, and the applied pressure will differ. This paper reviews the principles behind the different techniques, the types of membranes used, rejection mechanisms, and process modeling. Applications of pressure‐driven membrane processes are also considered, including reverse osmosis and nanofiltration for the treatment of wastewater from landfills and composting plants, nanofiltration in the textile industry, and ultrafiltration and microfiltration in drinking water production and wastewater treatment.Lastly, the paper discusses recent developments, including techniques to prevent membrane fouling by modifications affecting surface roughness or hydrophilicity/hydrophobicity, or by cleaning the membranes, and methods for treating or disposing of the retentate.
Psychological ownership and feelings of possession: three field studies predicting employee attitudes and organizational citizenship behavior
Authors: Van Dyne Linn , Pierce Jon L. 
Published: April 2004

AbstractAn increasing number of scholars and practitioners have emphasized the importance of ‘feelings of ownership’ for the organization (even when employees are not legal owners). In this exploratory study, we examine the relationships of psychological ownership with work attitudes and work behaviors. We start by developing hypotheses based on the psychology of possession and psychological ownership literatures. We then test these hypotheses with data from three field samples, using responses from over 800 employees, as well as manager and peer observations of employee behavior. Results demonstrate positive links between psychological ownership for the organization and employee attitudes (organizational commitment, job satisfaction, organization‐based self‐esteem), and work behavior (performance and organizational citizenship). More important, psychological ownership increased explained variance in organization‐based self‐esteem and organizational citizenship behavior (both peer and supervisor observations of citizenship), over and above the effects of job satisfaction and organizational commitment. Contrary to prior theoretical work on psychological ownership, results, however, fail to show an incremental value of psychological ownership in predicting employee performance. Copyright © 2004 John Wiley & Sons, Ltd.
Stage‐specific effect of N‐(4‐hydroxyphenyl)retinamide on cell growth in squamous cell carcinogenesis
Authors: Kabbout Mohamed , Hatoum Asma , Abou‐Lteif Ghada , Chakroun Imane , Homaidan Fadia R. , Darwiche Nadine 
Published: April 2004

AbstractSquamous cell carcinoma (SCC) is the most prevalent form of epithelial cancer. SCC results when normal epithelial cells undergo multiple neoplastic changes that culminate in the evolution of an invasive cancer. Retinoids are commonly used as chemopreventive and treatment agents in skin cancer; however, SCC progression is accompanied by a gradual loss of retinoid responsiveness. The synthetic retinoid N‐(4‐hydroxyphenyl)retinamide (HPR) has shown promising anti‐neoplastic activity in a variety of tumor cells, including those that are resistant to all‐trans retinoic acid (t‐RA). We investigated the effect of HPR on growth and apoptosis of squamous cells at different stages of carcinogenesis. We then determined if retinoic acid receptor (RAR) overexpression affected the outcome of HPR treatment. To model SCC malignant progression, we used a panel of murine keratinocytes representing different stages of squamous cell carcinogenesis. This panel consisted of primary keratinocytes, SP1 and 308 papilloma cell lines, the PAM‐212 squamous carcinoma cell line, and the spindle I7 cell line. With the exception of the primary keratinocytes, all cells were unresponsive to t‐RA treatment. Pharmacological concentrations of HPR were non‐cytotoxic to all keratinocytes tested and HPR sensitivity was stage‐dependent, with the papilloma cell lines being the most sensitive, and the spindle cells being the most resistant. Overexpression of RARγ in SP1 papilloma cells enhanced growth suppression and apoptosis induction by HPR. HPR‐induced growth suppression was accompanied by a simultaneous block in the G1 phase of the cell cycle in RAR‐transduced and control SP1 cells and differential regulation of cell cycle and apoptotic mediators. © 2004 Wiley‐Liss, Inc.
Crosslinking of oligomers bearing carbamoyloxyimino groups with their photochemical and thermal reactions
Authors: Suyama Kanji , Iriyama Hiroaki , Tsunooka Masahiro , Shirai Masamitsu 
Published: April 2004

AbstractCarbamoyloxyimino (COI) groups are precursors of photochemically base‐generating groups as well as those of thermally isocyanate‐generating groups. In this study, photochemical and thermal reactions of COI groups in oligomers were investigated by spectral analyses and solubility changes. Oligomers bearing three types of COI groups were prepared. COI groups in all oligomer films were photolyzed on irradiation with 254 nm of light and were deblocked to form isocyanato groups on heating. From the IR spectral analyses, the formation of urea linkage was confirmed by the decrease in isocyanato groups and peak generation because of urea groups on postexposure bake (PEB) treatment. For all oligomer films, PEB was effective for the enhancement of insolubilization of the films in tetrahydrofuran. Heating followed by irradiation was also effective for the insolubilization. These results indicated that photochemical and thermal treatments of COI groups afforded highly sensitive crosslinking systems because of photochemically generated basic groups and thermally generated isocyanato groups. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 2612–2620, 2004