bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of cleaning and coating techniques for PCB‐contaminated concrete
Authors: Pizarro Gonzalo E. L. , Dzombak David A. , Smith John R.
Published: April 2004

PCB‐contaminated concrete is a significant environmental management issue for many industrial facilities. The U.S. EPA has authorized exposure control in operating facilities via encapsulation or use of physical barriers when complete PCB removal is not technically achievable and/or is not cost‐effective. Achievement of effective encapsulation with epoxy coatings is challenging for PCB‐contaminated concrete as oil and/or other chemicals are often present. This work involved experimental investigation of encapsulation via cleaning and epoxy‐coating of PCB‐contaminated concrete. Experimental studies were performed with three cleaning techniques for removal of PCBs, and three epoxy‐coating systems for encapsulating PCBs. Resurfacing of oils and PCBs from concrete after cleaning, or “bleedback”, was also studied. These tests were conducted using PCB/oil‐contaminated concrete core samples from industrial plants. Results indicated that no cleaning system alone is effective as a long‐term solution for PCB‐contaminated concrete, and that bleedback occurred within days after cleaning due to capillary rise, affected by changes in wetting characteristics of the concrete pore surfaces and by elevated temperature induced by heating, which affects the density of the oil. The presence of free oil on the concrete surface resulted in failure of the coating systems, which occurred faster if heating was applied. Where appropriate surface preparation was performed, the integrity of the coatings remained intact throughout the experimental period (eight months). In such cases, the coating system acted effectively as a barrier against diffusion of PCBs. This study demonstrated that, except in high‐temperature areas, an epoxy coating can be an appropriate encapsulation system if proper surface preparation is applied. Metal sheet barriers can be used for high‐temperature applications.
Evaluation of PCBs biodegradability in sludges by various microbial cultures
Authors: Nakhla George , Kochany Jan , Lugowski Andrew
Published: April 2004

The application of aerobic and anaerobic treatment for removal of PCBs in sludges generated from a groundwater treatment system was investigated. The sludge was characterized by PCB concentrations of > 520 ppm, with Aroclors 1254 and 1260 accounting for 26 and 74%, respectively, as well as total organic carbon (TOC), and oil and grease (O&G) concentrations of 108,500 and 18,600 mg/L, respectively. Four treatments were explored: three aerobic and one anaerobic. Two types of bacterial innocula were aerobically tested: sludge from a poultry processing wastewater treatment plant, and a commercial seed (Petrobio®). Petrobio was tested aerobically with and without a biosurfactant/enzymes product (BOD‐Balance™), and was also tested anaerobically. Over a period of 60 days, PCB concentrations on a volumetric and solids basis were reduced by 73.4 to 88.0% and 64.7 to 80%, respectively. Aroclors 1254 and 1260 concentrations decreased by about 76 to 89%, and 73 to 89%, respectively. TOC and O&G removal efficiencies ranged from 77 to 93%, and from 52 to 86%, respectively.

Generally, sludge from the poultry processing facility achieved the best results and exhibited the most rapid biodegradation kinetics. Aerobic PCB biodegradation rates for Aroclors 1254 and 1260 were 13.5% and 23%, respectively, faster than the anaerobic biodegradation rates. Overall PCB biodegradation kinetics conformed to first‐order, with rate constants ranging from 0.017 d−1 under anaerobic conditions to 0.022 d−1 under aerobic conditions, while both TOC and O&G biodegradation kinetics followed first‐order kinetics, with rate coefficients in the ranges of 0.025–0.047 and 0.014 and 0.04 d−1, respectively.
Zeolite synthesis employing alkaline waste effluents from the aluminum industry
Authors: La Iglesia A. , González M. V. , Dufour J.
Published: April 2004

Zeolites 4A, 13X, Y, and HZSM5 have been synthesized from alkaline residues from aluminum finishing plants. These residues could contain concentrations of sodium aluminate and sodium hydroxide between 200 and 300 Kg/m3, and small concentrations of heavy metal cations (Cd, Co, Cr, Cu, Mn, and Zn). These contaminants make handling and disposal of these residues difficult.

However, the physicochemical properties of the synthesized zeolites (cation exchange capacity of 3 mmol g−1, specific surface area between 600–900 m2g−1, particle size distribution between 0.5–2 μm and whiteness of 97%) make them useful as detergents and catalysts.

Analysis of the chemical composition of the raw materials and the reaction products demonstrates that the heavy metal cation content in the synthesized zeolites is low enough to allow their industrial use (lower than that of the original residues). Therefore, the production of various types of zeolites for industrial use could be used for the elimination of these residues from the aluminum industry.
Removal of zinc and trichloroethylene from water by column extraction with a crude humic acid
Authors: Von Wandruszka Ray , Newell J. David
Published: April 2004

This paper presents an evaluation of the feasibility of removing high levels of zinc from mine run‐off by means of a crude humic substance. The process, in which the material was used as a solid adsorbent in an extraction column, achieved ⩾ 95% removal of the dissolved metal. The elution procedure could tolerate pH values down to 4 before metal leaching from the matrix became a problem. This was circumvented by the inclusion of marble chips in the extractor. Competition by high concentrations of common cations, such as calcium and magnesium, did not seriously impair zinc extraction. Anions were not retained, except for sulfate which was removed with 66% efficiency. Removal of dissolved trichloroethylene from water was virtually quantitative, without subsequent release of the contaminant from the extractant.
Absorption of NO2 in a packed tower with Na2SO3 aqueous solution
Authors: Chen Luke , Lin Jin‐Wei , Yang Chen‐Lu
Published: April 2004

This paper looks at the development of a two‐stage chemical scrubber for NOx control. In the first stage, the most practical oxidizing agents for NO oxidation are sodium chlorite and sodium hypochlorite. Although a considerable amount of work has been done on the reaction kinetics of NO2 with Na2SO3, there are major gaps in developing an Na2SO3 aqueous solution for NO2 absorption in the second stage. Of particular importance is the rate of chemical absorption. A pilot‐scale research program was initiated to evaluate the absorption rate of NO2 with Na2SO3 aqueous solution in a packed tower. The research is directed at obtaining height of a transfer unit (HTU) for NO2 absorption, and to determine reasonable operation conditions for the packed bed scrubber. A sulfite concentration of 0.25 M is essential to have a reasonable HTU in 2 to 5 feet for a gas rate between 1,050 to 2,350 lb/ft2 hr. The results indicate that the scrubbing effectiveness of NO2 increased with the L/G ratio, and an L/G of more than 3 is required for high NO2 absorption.
Hydrophobic pervaporation for environmental applications: Process optimization and integration
Authors: Lipnizki Frank , Field Robert W.
Published: April 2004

The focus of this paper is on the design of pervaporation units for wastewater treatment taking into account technical, economic, and environmental aspects. Two different sized industrial wastewater streams of water‐chloroform, and of water‐methyl‐isobutylketone (MIBK) are considered. Based on a wastewater stream of 1,500 kg/d, a semi‐batch process combining pervaporation with a decanter recycle loop is developed. Using this process, it is possible to recover over 99% of the organic components at concentrations of more than 98 wt. %. The treatment costs are between 0.11 to 0.16 $/kg wastewater. For the treatment of a wastewater stream of 1,000 kg/h, pervaporation combined with a decanter and recycling loop, as well as integrated in a hybrid process with adsorption, is considered. For MIBK, pervaporation with a decanter is the most attractive option taking economic and environmental aspects into account, while, for chloroform, the hybrid process is the better option. Treatment costs in all cases are about 0.03 $/kg wastewater. The recovery rate of the organic compounds is over 99% at concentrations over 98 wt. %. The authors concluded that pervaporation as a stand‐alone unit, or integrated into hybrid processes, offers significant advantages over conventional alternatives.
LCAccess: A global directory of life cycle assessment resources
Authors: Curran Mary Ann , Skone Timothy J.
Published: April 2004

LCAccess is an EPA‐sponsored Web site intended to promote the use of Life Cycle Assessment (LCA) in business decision‐making by facilitating access to data sources useful in developing a life cycle inventory (LCI). While LCAccess does not, itself, contain data, it is a searchable global directory of potential data sources, and serves as a central source for LCA information.
The photocatalytic oxidation of low concentration MTBE on titanium dioxide from groundwater in a falling film reactor
Authors: Almquist Catherine B. , Sahle‐Demessie Endalkachew , Enriquez Julius , Biswas Pratim
Published: April 2004

This study is focused on three main objectives: (1) to determine the feasibility of using a falling‐film slurry photocatalytic reactor for the degradation of methyl tertiary‐butyl ether (MTBE) in water, (2) to assess the feasibility of MTBE photo‐oxidation on TiO2 at low initial MTBE concentrations (< 1 mg/L), and (3) to compare the effectiveness of MTBE photo‐oxidation on TiO2 in synthetically‐contaminated water, and in actual MTBE‐contaminated groundwater samples.

The MTBE degradation rates observed in a laminar falling film photocatalytic reactor for synthetic samples, with concentrations ranging from 50 μg/L to 1 mg/L, were high, achieving nearly complete (99+%) degradation of 1 mg/L MTBE and its by products in less than 120 minutes. The calculated single‐pass conversions were as high as 60%, corresponding to residence times of approximately 5 seconds in the falling film reactor. The observed degradation products of MTBE oxidation were predominantly tert‐butyl alcohol (TBA) and tertbutyl formate (TBF).

However, tests conducted using groundwater samples showed significantly reduced photoactivity of TiO2 towards the degradation of MTBE. Aromatic species and dissolved metal and chloride ions present in the field samples compete with MTBE and molecular oxygen on the TiO2 surface, and hence delay and retard MTBE degradation.
An integrated industrial management facility for biological treatment of high nitrate and carbonaceous wastewater
Authors: Beeman Ralph E. , Reitberger Joseph H.
Published: April 2004

Biological wastewater treatment is not typically used for wastewater with high nitrate and carbonaceous content. Hence, facilities demonstrating effective treatment are of interest to the worldwide environmental community. DuPont's Nylon Intermediates manufacturing plant at Victoria, Texas, started operating such a wastewater facility approximately three years ago. The new wastewater management facility features an innovative anoxic/oxic (A/O) biological treatment plant, a constructed wetland, and land application pilot area for demonstrating beneficial reuse of the biosolids. The wastewater treatment process is working well, with Chemical Oxygen Demand (COD) removal above 99%, complete removal of nitrate and nitrite, and 100% permit compliance, since start‐up. The wetland has exceeded expectations for polishing, buffering, and community value. Land application has demonstrated beneficial reuse of biosolids by producing excellent quality hay, which is being fed to animals in a non‐human food chain pathway. The waste treatment facility has won numerous awards including the 2001 Texas Natural Resource Conservation Commission (TNRCC) Award for Wetland Education, the 2000 Water Environmental Federation (WEF) Industrial Water Quality Award, the 2001 WEF Award for Education, and the 2002 DuPont Sustainable Growth Award.
Robustness of a full‐scale biological system treating industrial CS2 emissions
Authors: Kraakman N. J. R. (Bart)
Published: April 2004

Carbon disulfide (CS2) emissions must be treated for health and safety reasons. In this paper, an illustration of a full‐scale bioreactor system to treat industrial CS2 emissions is presented. A definition of robustness could be used to determine the risks of the bioreactor installation for various applications, and to define effective operational procedures. Examples from field experience show that the bioreactor system described in this paper is robust for situations that are likely to occur under industrial conditions. Experience indicates that the overall risk for operating this system is less than 4% loss of total removal per year. Therefore, it is concluded that this system is a reliable technology for reducing industrial CS2 emissions.
A novel reactor for exploring the effect of water content on biofilter degradation rates
Authors: Ranasinghe Milinda A. , Gostomski Peter A.
Published: April 2004

A novel batch recycle reactor was developed to investigate the effect of water content changes on the biological degradation rate of gas phase contaminants in low water content systems, such as biofilters. The reactor tightly controlled the water content of the unsaturated packing material using the principle of a suction cell. Matric potential in the compost was controlled between −6 and −36 cm H2O. A soil water retention curve relating matric potential to gravimetric water content was generated for the compost. Periodic dry weight analyses of reactor samples, together with the water retention curve, verified moisture content control. Runs were performed with toluene as the contaminant using unamended compost at a constant temperature of 30°C. Degradation results indicated a linear, biologically limited degradation region, followed by a non‐linear region at lower concentrations. Elimination capacities were calculated for the linear region for different matric potentials along both the wetting and drying curves, and both changes in the water content and direction of approach affected the removal rates in the linear region. The elimination capacity ranged from 155 g/m3 hr to 24 g/m3 hr for toluene over the matric potential range investigated. Repeatability studies indicated that moisture content was most likely the parameter that influenced changes in performance.
Particle size distribution in slaughterhouse wastewater before and after coagulation‐flocculation
Authors: Sanchis María Isabel Aguilar , Sáez José , Lloréns Mercedes , Soler Antonio , Ortuño Juan F.
Published: April 2004

Solid particles were removed from a slaughterhouse liquid effluent by physicochemical treatment (coagulation‐flocculation process) using aluminium sulfate as the coagulant, and activated silica, powdered activated carbon, precipitated calcium carbonate, polyacrylic acid, or anionic polyacrylamide as coagulant aids to improve the settling time.

Once the optimal conditions of the coagulation‐flocculation process had been established (speed and time of stirring during flocculation, pH, coagulant and coagulant aid doses), the particle number and size distribution were measured before and after the addition of aluminium sulfate as the coagulant and the different coagulant aids, to determine the efficiency of the coagulation‐flocculation process. When aluminium sulfate was used without the coagulant aids, overall efficiency of particle removal was 87%. Use of powdered activated carbon, polyacrylic acid, or anionic polyacrylamide improved removal to values between 92 and 98%.
Comparison of in‐furnace dry sorbent injection full‐scale tests with laboratory‐scale sulfation correlations
Authors: Collado Francisco J.
Published: April 2004

In an effort to limit SO2 emissions to the current EU air pollutant regulations, flue gas desulfurization tests were performed with in‐furnace dry sorbent, Ca(OH)2, injection technology in the Spanish coal power station “Litoral.” The measured SO2 removals—19.5% using a Ca‐S ratio of 3 for a coal containing 0.53% of sulfur, and 26.4% with Ca/S = 1.75 for a coal with 0.73% of sulfur—were lower than predicted through a 1‐D model. Hence, it was thought that a 3‐D computational fluid dynamics (CFD) simulation of the injection of sorbent particles would assist in understanding this complex process. After the turbulent velocity and temperature fields in the furnace were modeled, representative sorbent particles were injected, obtaining the temperature and SO2 concentrations encountered by the particles as a function of time. These data were the input to the global sulfur capture model used to simultaneously analyze calcination, sintering and sulfation. The simulation compared well with the data measured in the power station, thus verifying laboratory‐scale correlations. The main conclusion is that the first temperatures encountered by the particles—in addition to the mean diameter, the sulfur content and the Ca/S ratio—control the sulfur retention. Further more, it is extremely difficult to accurately predict these temperatures without a CFD simulation. Low retentions were due to low sulfur concentration, the high mean diameter of the particles, and the position of the injection nozzles.
“Green engineering: Defining the principles”— resdts from the sandestin conference
Authors: Abraham Martin A. , Nguyen Nhan
Published: April 2004

During the week of May 19, 2003, approximately 65 engineers and scientists convened at the Sandestin Resort in Florida for the first conference on “Green Engineering: Defining the Principles,” sponsored by Engineering Conferences international. Overfour days, a series of oral and poster presentations inspired discussion of green engineering principles. Each day attendees met during breakout sessions to discuss specific elements of green engineering principles. By the end of the conference, a set of nine collectively agreed upon principles that summarized all breakout session discussions had been compiled. These represent a majority view of green engineering principles as determined during the Sandestin deliberations, and should not be construed as individual opinions of any of the participants or sponsors. The Environmental Protection Agency, National Science Foundation, Department of Energy (Los Alamos National Laboratory), and the Green Chemistry institute, all provided funds to support the meeting.
Maximizing resource recovery from waste streams
Authors: Grant Tim
Published: April 2004

Resource conservation and waste management have become two sides of the same argument. According to the Institutefor Local Self Reliance in the US., the recycling revolution begun in the l960s was a reaction “to the levels of waste in our economy and the pollution and suffering these habits cause worldwide” [1,2]. However, the recycling targetsetting of the early 1990s was focused on diversion from landfill, and it has taken another 10 years for the focus to shift back to the resource values approach, driven largely by the application of Life Cycle Assessment to the waste management system.

This paper examines materials in the waste stream to determine the “value proposition” in each material group, and to examine options for efficient resource use and recovery. Specifically, it discusses waste management issues associated with clean fill, food waste, timber waste, concrete and bricks, green waste, paper and board, metals, plastics, and glass.
Sustainable development: Evolution of the canadian approach
Authors: Nelson Chad
Published: April 2004

Canada is on a journey toward sustainable development. From early steps in the 1900s to better protect and manage our water resources, through to today's international negotiations to address complex global challenges, such as loss of biodiversity, poverty, and climate change, the journey continues.
A longitudinal analysis of the impact of workplace empowerment on work satisfaction
Authors: Laschinger Heather K. Spence , Finegan Joan E. , Shamian Judith , Wilk Piotr
Published: April 2004

A longitudinal predictive design was used to test a model linking changes in structural and psychological empowerment to changes in job satisfaction. Structural equation modeling analyses revealed a good fit of the data from 185 randomly selected staff nurses to the hypothesized model. Changes in perceived structural empowerment had direct effects on changes in psychological empowerment and job satisfaction. Changes in psychological empowerment did not explain additional variance in job satisfaction beyond that explained by structural empowerment. The results suggest that fostering environments that enhance perceptions of empowerment can have enduring positive effects on employees. Copyright © 2004 John Wiley & Sons, Ltd.
Patients with primary brain tumors as organ donors: Case report and review of the literature
Authors: Punnett Angela S. , McCarthy Lisa J. , Dirks Peter B. , Hawkins Cynthia , Bouffet Eric
Published: April 2004

Malignancy is considered a contra‐indication to organ donation, with a few possible exceptions. We present the case of a child with fatal intracranial hemorrhage from a primary brain tumor (PBT) whose organs were denied for transplant after recovery. We review the literature of organ donors with PBTs in the context of the current organ shortage and discuss the implications for the practicing oncologist. Transmission of donor brain tumor to organ recipients has been documented but the incidence appears to be very low. Risk factors for tumor transmission include underlying donor tumor histology, history of craniotomy and/or shunt placement, use of systemic chemotherapy and radiation therapy, and duration of disease prior to donation. Ongoing data collection by national registries will provide more information on the potential risk to organ recipients. It may be appropriate to expand the donor pool to include donors with PBTs in certain situations. The transplantation team ultimately decides upon the use of organs from specific donors. Many families will appreciate the opportunity to donate specific tissues even if solid organ transplantation is prohibited. © 2004 Wiley‐Liss, Inc.
Efficacy of continuous infusion 2‐CDA (cladribine) in pediatric patients with Langerhans cell histiocytosis
Authors: Stine Kimo C. , Saylors Robert L. , Saccente Suzanne , McClain Kenneth L. , Becton David L.
Published: April 2004

Patients with Langerhans cell histiocytosis (LCH) may behave differently depending on what sites are involved and the response or lack of response to earlier therapies. Therapy for high‐risk patients or those with multiple reactivations continues to be challenging because of variable response rates and frequent toxicities. The goals of this study were to determine the long‐term disease free survival in children with high‐risk or multiply reactivated LCH treated with 2‐CDA, and the toxicity of low dose continuous infusion (CI). Ten children with multiple reactivations or high‐risk disease as defined by the Histiocyte Society were treated with CI 2‐CDA and were evaluable for response and toxicity assessment. The starting dose of 2‐CDA was 5 mg/M2/day for 3 days and escalated to 6.5 mg/M2/day for 3 days if tolerated. The maximum number of courses of 2‐CDA per patient was limited to six. Fifty‐two courses of 2‐CDA were administered without difficulty. After the patient demonstrated no acute toxicity with the first administration of 2‐CDA, the subsequent doses were given at home to all but one patient. All 10 patients had a clinical response, 9 documented by radiographic, or changes in physical exam or review of systems. Toxicity was limited to myelosuppression. Seven of the 10 patients required no additional therapy and remain disease free a median of 50 months from completing therapy. The three remaining patients are currently disease free after receiving other therapy. Further studies are needed to determine the role of 2‐CDA in this patient population. 2‐CDA can be given safely using home therapy, and may effective even in high‐risk patients. © 2004 Wiley‐Liss, Inc.
Cross‐species identification of proteins from proteome profiles of the marine oligotrophic ultramicrobacterium, Sphingopyxis alaskensis
Authors: Ostrowski Martin , Fegatella Fitri , Wasinger Valerie , Guilhaus Michael , Corthals Garry L. , Cavicchioli Ricardo
Published: April 2004

Sphingopyxis (formerly Sphingomonas) alaskensis is a model bacterium for studying adaptation to oligotrophy (nutrient‐limitation). It has a unique physiology which is fundamentally different to that of the well studied bacteria such as Escherichia coli. To begin to identify the genes involved in its physiological responses to nutrient‐limited growth and starvation, we developed high resolution two‐dimensional electrophoresis (2‐DE) methods and determined the identity of 12 proteins from a total of 21 spots using mass spectrometric approaches and cross‐species matching. The best matches were to Novosphingobium aromaticivorans; a terrestrial, hydrocarbon degrading bacterium which was previously classified in the genus Sphingomonas. The proteins identified are involved in fundamental cellular processes including protein synthesis, protein folding, energy generation and electron transport. We also compared radiolabelled and silver‐stained 2‐DE gels generated with the same protein samples and found significant differences in the protein profiles. The use of both methods increased the total number of proteins with differential spot intensities which could be identified from a single protein sample. The ability to effectively utilise cross‐species matching from radiolabelled and silver‐stained gels provides new approaches for determining the genetic basis of microbial oligotrophy.
Normal state understanding within a Fermi liquid approach
Authors: Sfar I. , Charfi‐Kaddour S. , Héritier M. , Bennaceur R.
Published: April 2004

Using the Hubbard model in the weak coupling limit within a Fermi liquid approach, we have studied spin fluctuation effects in quasi‐2D superconductors such as high critical temperature superconductors. We show that, due to nesting properties of the Fermi surface, the magnetic and the transport properties are different from the behaviours we should observe in usual metal, because of strong magnetic fluctuation effect. We distinguish different regions in the normal state with different dependences as a function of temperature for several properties, such as the resistivity, NMR relaxation rate and spin susceptibility. We show that the pseudo‐gap region is strongly related to the existence of a pseudo‐gap in the density of states at the Fermi level. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A little language for modularizing numerical PDE solvers
Authors: Hohn Michael H.
Published: April 2004

This paper describes a concise specification language for linear partial differential equations (PDEs) on a union of rectangles, along with three tools: a pretty‐printer, TEX generator, and a code generator. The pretty‐printer and TEX generator help users by allowing equations to be specified (and read) in their natural form, while the code generator allows implementors to separate their numerical solver from the input equations, and greatly simplifies testing. Copyright © 2004 John Wiley & Sons, Ltd.
Building a new sort function for a C library
Authors: Chen Jing‐Chao
Published: April 2004

Up to now, the most efficient sort function for a C library was a variant of Hoare's Quicksort (qsort, for short), which was proposed by Bentley and McIlroy in the early 1990s. Here we call this library function BM qsort. This paper introduces a library function which is based on Chen's Proportion Extend Sort (psort). This work is inspired by the fact that psort is generally faster than qsort, and in the worst case, qsort requires O(n2) comparisons, while psort requires O(n log n). In our library function, many tricks used in BM qsort have been adopted, such as sorting a small array by an insertion sort and the handling of equal elements. Some new tricks are also proposed, however, such as the adaptive partitioning scheme. To assess more effectively the behavior of our function, the test cases are enhanced. The empirical results show that our function is robust and faster than BM qsort. On particular classes of inputs, such as ‘already sorted’, it is linear time. Copyright © 2004 John Wiley & Sons, Ltd.
Code optimizations for a VLIW‐style network processing unit
Authors: Kim Jinhwan , Paek Yunheung , Uh Gangryung
Published: April 2004

The explosive growth in network bandwidth and Internet services such as QoS (quality of service) and SLA (service level agreement) monitoring have created the need for new networking hardware called aNetwork Processing Unit (NPU). In order to rapidly reconfigure the NPU for frequently varying Internet services and technologies, a high‐performance C compiler is urgently needed. Several code generation techniques, which are intended to meet the high code quality demands of other types ofapplication specific instruction‐set processors(ASIPs) likedigital signal processors(DSPs), have already been developed. However, these techniques are insufficient for NPUs due to striking architectural differences such as asymmetric data paths. The main purpose of this paper is to discuss our recent experience with the development of a commercial compiler for a new NPU called thePaion PPII, which is basically apacket enginefor NPU to meet the growing need for new high‐bandwidth communication equipment targeted for Internet routers and ethernet adapters. For this purpose, we will first show the architectural challenges posed by the target NPU. Then, we will describe several compiler techniques that we found to be effective for the target NPU with various unorthogonal architectural features. The current implementations of the PPII use a VLIW (Very Long Instruction Word) architecture. So, we handled this VLIW‐style architecture by employing a simplecode compactionscheme which packs multiple parallel instructions into one long instruction word. The experimental results show that our techniques are effective for significantly reducing the dynamic instruction count. Copyright © 2004 John Wiley & Sons, Ltd.
Growth and Characterization of BPO4Single Crystals
Authors: Schmidt M. , Ewald B. , Prots Yu. , Cardoso‐Gil R. , Armbrüster M. , Loa I. , Zhang L. , Huang Ya‐Xi , Schwarz U. , Kniep R.
Published: April 2004

Single crystals of BPO4were grown by chemical transport reactions with PCl5using a gradient from 1073 K to 973 K as well as with solvothermal syntheses in the temperature range between 413 K and 523 K using water, ethanol or 2‐propanol as polar protic solvents. The atomic arrangement of BPO4was reinvestigated by means of single crystal X‐ray diffraction data and confirmed the earlier findings with significantly smaller standard deviations. Thermogravimetric investigations of powdered samples which show no extra lines in X‐ray diffraction diagrams revealed weight decrements which are attributed to water losses. The presence of protonated borate and phosphate species in a number of X‐ray pure solvothermally grown BPO4samples is evidenced by infrared spectroscopy.
Chemical Conversion of Hg‐Clusters: Synthesis and Crystal Structure of $ {\rm [(DMSO)_2 Co(NC \overline{S)_4(Hg}-TePh)_2]_{\rm n} }$, the First Compound Containing a Polymeric Hg—Te Chain
Authors: Schulz Lang Ernesto , de Oliveira Gelson Manzoni , Back Davi Fernando , dos Santos Sailer Santos
Published: April 2004

The six‐membered ring Hg3Te3 of [Hg3Cl3(μ‐TePh)3]·2 DMSO {(Ph = C6H5; DMSO = (CH3)2SO} was opened by redissolution with DMSO, reacting with Co[Hg(SCN)4] and affording polymeric $ {\rm [(DMSO)_2 Co(NC \overline{S)_4(Hg}-TePh)_2]_{\rm n} }$. The monoclinic novel compound belong to the space group P21/n and assembles in a bidimensional lattice tetrahedral HgII(SCN)2Te2‐ and octahedral CoII(NCS)4(DMSO)2‐chains linked trough SCN bridges along the crystallographic axis b and diagonally to the ac axes. The structure of [(DMSO)2Co(NCS)4(Hg—TePh)2]n is limited by the DMSO ligands in the axial positions of the Co‐octahedrons.
Organotin Dyes: Synthesis and Structural Characterization of Dibutyltin and Dimethyltin Complexes with 2, 2′‐Dihydroxyazobenzene
Authors: Bessler Karl Eberhard , dos Santos Jennifer Alves , Deflon Victor Marcelo , de Souza Lemos Sebastião , Niquet Elke
Published: April 2004

The preparation and structures of 2, 2′‐dihydroxyazobenzenato‐dibutyl‐tin [Bu2SnL] and 2, 2′‐dihydroxyazobenzenato‐dimethyl‐tin [Me2SnL] are described. The complexes were characterized by IR, NMR (1H, 13C, 119Sn) and UV/VIS spectra. The crystal structures were determined by X‐ray diffraction on single crystals. [Bu2SnL]: monoclinic, space group P21/c, cell constants at 208 K: a = 860.73(5), b = 973, 51(18), c = 2340.0(3) pm, β = 93.615(11)°; R1 = 0.0546. [Me2SnL]: orthorhombic, space group Pbcn, cell constants at 208 K: a = 1914.6(4), b = 1041.3(3), c = 1323.27(14) pm; R1 = 0.0529.
Contra Coercion: Russian Tax Reform, Exogenous Shocks, and Negotiated Institutional Change
Authors: LUONG PAULINE JONES , WEINTHAL ERIKA
Published: April 2004

The view of institutions as coercion rather than as contracts dominates the comparative politics literature on both institutional creation and the politics of economic reform. The emergence of a collectively optimal tax code in Russia demonstrates the limitations of this emphasis on coercion. This new tax code was not imposed by a strong central leader, mandated by international institutions, or the result of state capture by powerful economic interest groups. Rather, it is the product of a mutually beneficial exchange between the Russian government and the Russian oil companies. Russia's ability to negotiate an effective tax regime also suggests the conditions under which and the microcausal mechanism whereby exogenous shocks promote institutional change and economic reform. Owing to their mutual vulnerability and interdependence, the August 1998 financial crisis generated widely shared perceptions among these actors that the payoffs of cooperation had changed. Yet the economic reform institution that resulted required a series of incremental strategic moves that established common knowledge.
The use and abuse of developmental data
Authors: Northcutt R. Glenn
Published: April 2004

Structural similarity is helpful in recognizing homologous structures, but it does not define them. Such structures must also have phylogenetic continuity, a criterion that is ignored by Aboitiz et al. and by proponents of “field homology.” “Similar” structures, as well as “field homologues” from “the same” embryonic field, are not necessarily homologous, and an outgroup analysis of developmental stages should be performed to establish homologies.
Dual-process theories and hybrid systems
Authors: Pyysiäinen Ilkka
Published: April 2004

The distinction between such differing approaches to cognition as connectionism and rule-based models is paralleled by a distinction between two basic modes of cognition postulated in the so-called dual-process theories. Integrating these theories with insights from hybrid systems might help solve the dilemma of combining the demands of evolutionary plausibility and computational universality. No single approach alone can achieve this.
Relevance of medial and dorsal cortex function to the dorsalization hypothesis
Authors: Powers Alice Schade
Published: April 2004

The overall dorsalizing effect proposed by the authors may be consistent with behavioral evidence showing that the dorsal cortex of reptiles functions like the hippocampal formation of mammals. It is suggested that the dorsal cortex of reptiles expanded in this dorsalizing process to become both entorhinal/subicular cortex and sensory neocortex.
More dorsal cortex, yes, but what flavor?
Authors: Treves Alessandro
Published: April 2004

Where the isocortex comes from is an important question, but even more important is understanding what it leads to – that is, what advantage is afforded by its peculiar organization in layers of distinct neuronal types. A computational hypothesis accounts for granulation and for the differentiation between supra- and infragranular pyramidal layers, as quantitatively advantageous to support fine topography in sensory maps.
Counteraction of urea-induced protein denaturation by trimethylamine
N
-oxide: A chemical chaperone at atomic resolution
Authors: Bennion Brian J. , Daggett Valerie
Published: April 2004

Proteins are very sensitive to their solvent environments. Urea is a common chemical denaturant of proteins, yet some animals contain high concentrations of urea. These animals have evolved an interesting mechanism to counteract the effects of urea by using trimethylamine
N
-oxide (TMAO). The molecular basis for the ability of TMAO to act as a chemical chaperone remains unknown. Here, we describe molecular dynamics simulations of a small globular protein, chymotrypsin inhibitor 2, in 8 M urea and 4 M TMAO/8 M urea solutions, in addition to other control simulations, to investigate this effect at the atomic level. In 8 M urea, the protein unfolds, and urea acts in both a direct and indirect manner to achieve this effect. In contrast, introduction of 4 M TMAO counteracts the effect of urea and the protein remains well structured. TMAO makes few direct interactions with the protein. Instead, it prevents unfolding of the protein by structuring the solvent. In particular, TMAO orders the solvent and discourages it from competing with intraprotein H bonds and breaking up the hydrophobic core of the protein.
F1F0 ATP synthase subunit c is a substrate of the novel YidC pathway for membrane protein biogenesis
Authors: van der Laan Martin , Bechtluft Philipp , Kol Stef , Nouwen Nico , Driessen Arnold J.M.
Published: April 2004

The Escherichia coli YidC protein belongs to the Oxa1 family of membrane proteins that have been suggested to facilitate the insertion and assembly of membrane proteins either in cooperation with the Sec translocase or as a separate entity. Recently, we have shown that depletion of YidC causes a specific defect in the functional assembly of F1F0 ATP synthase and cytochrome o oxidase. We now demonstrate that the insertion of in vitro–synthesized F1F0 ATP synthase subunit c (F0c) into inner membrane vesicles requires YidC. Insertion is independent of the proton motive force, and proteoliposomes containing only YidC catalyze the membrane insertion of F0c in its native transmembrane topology whereupon it assembles into large oligomers. Co-reconstituted SecYEG has no significant effect on the insertion efficiency. Remarkably, signal recognition particle and its membrane-bound receptor FtsY are not required for the membrane insertion of F0c. In conclusion, a novel membrane protein insertion pathway in E. coli is described in which YidC plays an exclusive role.
PINdb: a database of nuclear protein complexes from human and yeast
Authors: Luc Phuong-Van , Tempst Paul
Published: April 2004

Summary: Proteins Interacting in the Nucleus database (PINdb) is a database of protein complexes purified from the nucleus of human and yeast cells. It is compiled from the published literature and existing databases. Currently, PINdb contains mostly protein complexes that may be involved in gene transcription. To facilitate comparative analyses and identification of protein complexes, the compositional information is integrated with standardized gene nomenclature, annotation and protein sequences from public databases. The PINdb web interface provides a number of tools for (1) comparison of protein complexes, (2) search for a protein complex by its published name or by a partial list of its components and (3) browsing specific subsets or a functional classification of the complexes.

Availablity:  http://pin.mskcc.org
The SRS 3D module: integrating structures, sequences and features
Authors: O'Donoghue Seán I. , Meyer Joachim E. W. , Schafferhans Andrea , Fries Karsten
Published: April 2004

Summary: In this paper we present SRS 3D, a new service that allows users to easily and rapidly find all related structures for a given target sequence; structures can then be viewed together with sequences, alignments and sequence features (currently from UniProt, InterPro and PDB). Extensive user feedback confirms that SRS 3D is intuitive and useful especially for those not expert in structures.

Availability: An SRS 3D server is provided at http://srs3d.ebi.ac.uk/

Supplementary information: Complete documentation is available (click the ‘Help’ button after login). Product information can be found at http://www.lionbioscience.com/SRS3D/products/srs/srs-3d
Alteration of the disulfide‐coupled folding pathway of BPTI by circular permutation
Authors: Bulaj Grzegorz , Koehn Rachel E. , Goldenberg David P.
Published: April 2004

The kinetics of disulfide‐coupled folding and unfolding of four circularly permuted forms of bovine pancreatic trypsin inhibitor (BPTI) were studied and compared with previously published results for both wild‐type BPTI and a cyclized form. Each of the permuted proteins was found to be less stable than either the wild‐type or circular proteins, by 3–8 kcal/mole. These stability differences were used to estimate effective concentrations of the chain termini in the native proteins, which were 1 mM for the wild‐type protein and 2.5 to 4000 M for the permuted forms. The circular permutations increased the rates of unfolding and caused a variety of effects on the kinetics of refolding. For two of the proteins, the rates of a direct disulfide‐formation pathway were dramatically increased, making this process as fast or faster than the competing disulfide rearrangement mechanism that predominates in the folding of the wild‐type protein. These two permutations break the covalent connectivity among the β‐strands of the native protein, and removal of these constraints appears to facilitate direct formation and reduction of nearby disulfides that are buried in the folded structure. The effects on folding kinetics and mechanism do not appear to be correlated with relative contact order, a measure of overall topological complexity. These observations are consistent with the results of other recent experimental and computational studies suggesting that circular permutation may generally influence folding mechanisms by favoring or disfavoring specific interactions that promote alternative pathways, rather than through effects on the overall topology of the native protein.
Association between −250G/A polymorphism of the hepatic lipase gene promoter and coronary artery disease and HDL‐C levels in a Southern Brazilian population
Authors: De Andrade FM , Silveira FR , Arsand M , Antunes ALS , Torres MR , Zago AJ , Callegari‐Jaques SM , Hutz MH
Published: April 2004

Hepatic lipase (HL) is a glycoprotein that plays a major role in remodeling high‐density lipoprotein (HDL). The effect of the −250G/A promoter polymorphism on coronary artery disease (CAD) and lipid levels was studied in 231 male CAD patients and in a population‐based sample of men and women (n = 514). A sample of 140 men was chosen among those included in the population‐based sample as controls for the CAD sample. In the total group of CAD patients, the frequency of the −250A allele was somewhat lower (25% in CAD patients and 32% in controls; p = 0.06), but when the control samples were compared only with the CAD+ sample (more than 60% of luminal stenosis in at least one coronary artery or major branch segment) the −250A allele was significantly less frequent (23% in the patients vs 32% in controls; p = 0.02). A multiple logistic regression analysis showed that this association was independent of classical CAD risk factors [odds ratio (OR) = 1.79, p = 0.025]. Using multiple linear regression analyses, it has been shown that this polymorphism was a significant factor affecting HDL‐C levels in men from the population‐based sample (p = 0.001), an interaction between −250G/A variant and wine consumption was also detected (p = 0.001). Thus, our results show that the −250G/A polymorphism in the HL gene is associated with significant variations in HDL‐C levels and CAD risk in males.
Utility Functions for Ceteris Paribus Preferences
Authors: McGeachie Michael , Doyle Jon
Published: April 2004

Ceteris paribus (all‐else equal) preference statements concisely represent preferences over outcomes or goals in a way natural to human thinking. Although deduction in a logic of such statements can compare the desirability of specific conditions or goals, many decision‐making methods require numerical measures of degrees of desirability. To permit ceteris paribus specifications of preferences while providing quantitative comparisons, we present an algorithm that compiles a set of qualitative ceteris paribus preferences into an ordinal utility function. Our algorithm is complete for a finite universe of binary features. Constructing the utility function can, in the worst case, take time exponential in the number of features, but common independence conditions reduce the computational burden. We present heuristics using utility independence and constraint‐based search to obtain efficient utility functions.
Soft Constraint Propagation and Solving in Constraint Handling Rules
Authors: Bistarelli S. , Frühwirth T. , Marte M. , Rossi F.
Published: April 2004

Soft constraints are a generalization of classical constraints, which allow for the description of preferences rather than strict requirements. In soft constraints, constraints and partial assignments are given preference or importance levels, and constraints are combined according to combinators which express the desired optimization criteria. On the other hand, constraint handling rules (CHR) constitute a high‐level natural formalism to specify constraint solvers and propagation algorithms. We present a framework to design and specify soft constraint solvers by using CHR. In this way, we extend the range of applicability of CHR to soft constraints rather than just classical ones, and we provide a straightforward implementation for soft constraint solvers.
CBPOP: A Domain‐Independent Multi‐Case Reuse Planner
Authors: Britanik J. , Marefat M.
Published: April 2004

The reuse of multiple cases to solve a single planning problem presents a promise of better utilization of past experience over single‐reuse planning, which can lead to better planning performance. In this paper, we present the theory and implementation of CBPOP, and show how it addresses the multi‐reuse planning problems. In particular, we present novel approaches to retrieval and refitting. We also explore the difficult issue of when to retrieve in multi‐reuse scenarios, and we empirically compare the results of several solutions we propose. Results from our experiments show that the best ranking function for pure generative planning is not necessarily the best ranking function for multi‐reuse planning. The surprising result in the reuse scenarios is that the single‐goal case library performed better than larger case libraries consisting of solutions to multi‐goal problems.
Equilibrium Selection and Stability for the Groves Ledyard Mechanism
Authors: Page Scott E. , Tassier Troy
Published: April 2004

In their seminal paper Groves and Ledyard (1976) construct a balanced incentive compatible mechanism that solves the free rider problem. In subsequent research, Bergstrom, Simon, and Titus (1983) prove that there exist numerous asymmetric equilibria in addition to the symmetric equilibrium. In the present paper, we explicitly solve for the additional equilibria and use computational experiments to examine the structure and stability of the set of equilibria of the Groves Ledyard Mechanism. We find that all of the equilibria found by Berstrom, Simon, and Titus are unstable and that for a high level of the punishment parameter these equilibria do not exist. Further, we find that there exists an additional boundary equilibrium for each of the equilibria found by Bergstrom, Simon, and Titus. The boundary equilibria are all stable.