bluuebunny/crossref_metadata_2025 huggingface dataset:
Principles of 3′ splice site selection and alternative splicing for an unusual group II intron from Bacillus anthracis
Authors: ROBART AARON R. , MONTGOMERY NANCY KRISTINE , SMITH KIMOTHY L. , ZIMMERLY STEVEN
Published: April 2004

We investigated the self-splicing properties of two introns from the bacterium Bacillus anthracis. One intron (B.a.I1) splices poorly in vitro despite having typical structural motifs, while the second (B.a.I2) splices well while having apparently degenerated features. The spliced exons of B.a.I2 were sequenced, and splicing was found to occur at a 3′ site shifted one nucleotide from the expected position, thus restoring missing γ-γ′ and IBS3–EBS3 pairings, but leaving the two conserved exonic ORFs out of frame. Because of the unexpected splice site, the principles for 3′ intron definition were examined, which showed that the 3′ splice site is flexible but contingent on γ-γ′ and IBS3–EBS3 pairings, and can be as far away as four nucleotides from the wild-type site. Surprisingly, alternative splicing occurs at position +4 for wild-type B.a.I2 intron, both in vitro and in vivo, and the alternative event fuses the two conserved exon ORFs, presumably leading to translation of the downstream ORF. The finding suggests that the structural irregularities of B.a.I2 may be an adaptation to facilitate gene expression in vivo.
Designing Supply Contracts: Contract Type and Information Asymmetry
Authors: Corbett Charles J. , Zhou Deming , Tang Christopher S.
Published: April 2004

This paper studies the value to a supplier of obtaining better information about a buyer's cost structure, and of being able to offer more general contracts. We use the bilateral monopoly setting to analyze six scenarios: three increasingly general contracts (wholesale-pricing schemes, two-part linear schemes, and twopart nonlinear schemes), each under full and incomplete information about the buyer's cost structure. We allow both sides to refuse to trade by explicitly including reservation profit levels for both; for the supplier, this is implemented through a cutoff policy. We derive the supplier's optimal contracts and profits for all six scenarios and examine the value of information and of more general contracts. Our key findings are as follows: First, the value of information is higher under two-part contracts; second, the value of offering two-part contracts is higher under full information; and third, the proportion of buyers the supplier will choose to exclude can be substantial.
The Audience for Aristotle's Rhetoric
Authors: Clayton Edward W.
Published: April 2004

Abstract Although there is general consensus that knowledge of Aristotle's intended audience is important for understanding the Rhetoric, there is no consensus about who that audience is. In this essay, four of the most widely accepted theories are investigated: that Aristotle is writing for the legislator of an ideal city; that Aristotle is writing for the Athenian public or an elite subset of that public; that Aristotle is writing for his students; and that the Rhetoric was written for multiple audiences over an extended period of time. Ultimately, the most plausible of these explanations is that he is writing for his students.
Oriented Assemblies of ZnS One‐Dimensional Nanostructures
Authors: Zhu Y.‐C. , Bando Y. , Xue D.‐F. , Golberg D.
Published: April 2004

Oriented ZnS nanobelt arrays and ZnS multicore microcables consisting of oriented nanowire bundles with sheaths (see Figure) have been synthesized via a controlled thermal process. Both the ZnS nanowires and nanobelts are single crystals grown along the [001] axis. The special structures of the oriented assemblies of ZnS one‐dimensional nanostructures may have potential applications in nanoelectronics and photonics.
Controlled Fluorescence Bursts from Conjugated Polymers Induced by Triplet Quenching
Authors: Schindler F. , Lupton J. M. , Feldmann J. , Scherf U.
Published: April 2004

Dramatic fluorescence bursts (see Figure and cover) from conjugated polymers are observed upon exposure to air. The burst occurs prior to photo‐oxidation and is imaged in single molecules of a ladder‐type polymer, but is also found in bulk films. Triplet shelving is identified as an important mechanism limiting the fluorescence yield of conjugated polymers due to both a reduction in photon cycling rates and singlet–triplet quenching in the multichromophoric system.
New case of thyroid dysgenesis and clinical signs of hypothyroidism in Williams syndrome
Authors: Bini Rita , Pela Ivana
Published: April 2004

The authors report a female presenting with congenital heart defects, liver hemangiomas, and facial dysmorphisms admitted to hospital at 3 months of age because of feeding difficulties and poor growth. She had hypotonia and large tongue, “coarse” face, and umbilical hernia in presence of complex congenital cardiovascular malformations. In spite of normal neonatal screening we performed serum levels of thyroid hormones. Thyrotropin level was very high (>50 μU/ml; normal value 0.2–4 μU/ml), while serum free T3 (FT3) and free T4 (FT4) levels were normal (FT3 3.6 pg/ml, normal value 2.8–5.6 pg/ml; FT4 11.6 pg/ml, normal value 6.6–14 pg/ml); antithyroid autoantibodies were absent. Thyroid scintigraphy with sodium 99m Tc pertechnetate showed a small ectopic thyroid located in sublingual position, so treatment with L‐thyroxine 37.5 μg/24 hr was started with rapid improvement of the clinical picture. At 17 months of age the patient developed the complete characteristic phenotype of Williams syndrome (WS); the clinical diagnosis was proven by fluorescent in situ hybridization (FISH) analysis which showed hemizygous deletion of the elastin gene on chromosome 7. Recently a case of thyroid hemiagenesis in a child with WS has been reported; our patient underscores the association of hypothyroidism and WS. Moreover, our case shows that clinical manifestations of hypothyroidism may be present and the treatment may be necessary as it is in isolated congenital hypothyroidism. © 2004 Wiley‐Liss, Inc.
Hereditary fetal brain degeneration resembling fetal brain disruption sequence in two sibships
Authors: Schram Aaltje , Kroes Hester Y. , Sollie Krystyna , Timmer Bert , Barth Peter , van Essen Ton
Published: April 2004

We present two families with sib recurrence of a phenotype which was originally diagnosed as fetal brain disruption sequence (FBDS). In the first family from the Hindu population of Surinam, two brothers were affected. In the second family of Dutch descent a brother and sister were affected. Periodic ultrasonic sound examinations of brain development of the girl in the second family appeared normal until 26 weeks of gestation after which progressive destruction of her brain was seen. Recurrence of the FBDS in a family is noteworthy as it is usually considered a sporadic disorder. Suggested causes in the literature are viral infections or early vascular interruption of the fetal brain with subsequent massive destruction of cerebral neurons. In 1995 the first familial case of FBDS was described, indicating a genetic cause. Recently Kavaslar et al. [2000: Am J Hum Genet 66:1705–1709.] found a locus on chromosome 16 in a large inbred Anatolian family with a phenotype resembling FBDS. Our experience and the literature show that the cause of the phenotype “FBDS” is heterogeneous. In case of sib recurrence the term FBDS should be avoided since a disruption sequence indicates an exogenous and sporadic cause of the disorder. © 2004 Wiley‐Liss, Inc.
Family‐based association study of schizophrenia with 444 markers and analysis of a new susceptibility locus mapped to 11q13.3
Authors: Yamada K. , Iwayama‐Shigeno Y. , Yoshida Y. , Toyota T. , Itokawa M. , Hattori E. , Shimizu H. , Yoshikawa T.
Published: April 2004

Family‐based linkage disequilibrium (LD) mapping has been suggested as a powerful and practical alternative to linkage analysis. We have performed a genome‐wide LD survey of susceptibility loci for schizophrenia in a Japanese population. We first typed 119 schizophrenic pedigrees (357 individuals) using 444 microsatellite markers, and analyzed the data using the pedigree disequilibrium test. This analysis revealed 14 markers demonstrating significant transmission distortion. To corroborate these findings, the statistical methods were changed to the extended transmission disequilibrium test (ETDT), using 80 independent complete trios (schizophrenic proband and both parents), with 68 derived from initial pedigrees and 12 newly recruited trios. ETDT supported two markers for continued association, D11S987 on 11q13.3 (P = 0.00009) and D16S423 on 16p13.3 (P = 0.002). We scrutinized the most significant genomic locus on 11q11‐13 by adding 26 new markers for analysis. Results of three‐marker haplotype analysis in the region showed evidence of association with schizophrenia (most significant haplotype P = 0.0005, global P = 0.022). Although the present study may have missed other potential genomic intervals because of the sparse mapping density, we hope that it has identified promising anchor points for further studies to identify risk‐conferring genes for schizophrenia in the Japanese population. In addition, we provide useful information on genomic LD structures in Japanese populations, which can be used for LD mapping of complex diseases. © 2004 Wiley‐Liss, Inc.
Adrenergic alpha 2C receptor genomic organization: Association study in adult ADHD
Authors: De Luca Vincenzo , Muglia Pierandrea , Vincent John B. , Lanktree Matthew , Jain Umesh , Kennedy James L.
Published: April 2004

Attention deficit hyperactivity disorder (ADHD) is a chronic psychiatric condition in children and follow up studies have indicated that one to two thirds of patients continue to suffer from ADHD during late adolescence and adulthood. Pharmacological interventions, such as the new selective noradrenergic reuptake inhibitor, atomoxetine, suggest the adrenergic system as candidate in ADHD. We examined for the presence of linkage disequilibrium between the alpha 2C adrenergic receptor (ADRA2C) microsatellite polymorphism upstream of the ADRA2C gene and adult ADHD in a sample of nuclear families. We also present new information on the genomic organization of the ADRA2C locus. The microsatellite polymorphism was typed in 128 small families and analyzed using the Transmission Disequilibrium Test (TDT). There was no preferential transmission of any allele. These findings exclude a strong effect of this ADRA2C marker on risk for ADHD in our sample of adult proband families. © 2004 Wiley‐Liss, Inc.
The effects of chemical structure on the shear rheology of aliphatic polycarbonates
Authors: Thorat Sudhir D. , Phillips P. J. , Semenov Viktor , Gakh Andre
Published: April 2004

Aliphatic polycarbonates are a relatively new class of polymer, which are characterized by an instability at the functional group, which makes them easily degraded and capable of biodegradation; as such, they constitute a potentially powerful group of polymers for exploitation in green technology. Rheological properties in shear flow are presented for the seven following different aliphatic polycarbonate samples: polyethylene carbonate, polypropylene carbonate, linear pentene polycarbonate, linear hexene polycarbonate, linear octene polycarbonate, cyclohexene polycarbonate, copolymer of propylene oxide (20%), and cyclohexene oxide (80%), using parallel plate rheometry. No studies of the rheological properties of aliphatic polycarbonates have been reported in the literature to date. The steady‐state and the dynamic properties of these new polymers are investigated, and the resulting flow curves and the dynamic relaxation spectra of the aliphatic polycarbonate melts are presented. One of the major problems encountered in trying to characterize the melt rheology and relate behavior to the underlying molecular structure is the instability of the polymers. Because of this, a narrow processing window is present for each polymer, and it makes it impossible to compare all polymers at a constant temperature or range of temperatures in the melt. Nevertheless, some progress can be made. In all cases, the rheological response is discussed in terms of molecular characteristics, in particular, the length of the side chain and the molecular weight distribution. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 534–544, 2004
Synthesis and properties of thermoplastic expandable microspheres: The relation between crosslinking density and expandable property
Authors: Kawaguchi Yasuhiro , Oishi Tsutomu
Published: April 2004

A set of thermoplastic expandable microspheres was investigated with respect to their crosslinking density and expandable property. The crosslinking efficiencies of dipentaerythritol hexaacrylate in a set of thermoplastic expandable microspheres were measured. As expandable properties, expansion curves were measured by using a thermomechanical analyzer, and they also were shown by measuring the change of thickness of the coated compound consisting of ethylene–vinyl acetate copolymer resin emulsion and CaCO3 with thermoplastic microspheres on paper. In view of the expansion ratio and heat resistance, as crosslinking density, a swelling ratio of about 20–25 is needed to achieve optimum expansion without collapse and rupture of microspheres. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 505–512, 2004
Solubilization of phthalocyanines into methanol with fluoroalkyl end‐capped N‐(1,1‐dimethyl‐3‐oxobutyl)‐ and N,N‐dimethyl‐acrylamide oligomers
Authors: Sasazawa Kazuo , Okitsu Isao , Aburatani Azusa , Kawase Tokuzo , Sawada Hideo
Published: April 2004

Self‐assembled molecular aggregates of fluoroalkyl end‐capped N‐(1,1‐dimethyl‐3‐oxobutyl)‐ and N,N‐dimethyl‐acrylamide oligomers in methanol were found to interact with phthalocyanines as guest molecules to exhibit good solubility. On the other hand, the corresponding nonfluorinated oligomers were not effective in solubilizing phthalocyanines under similar conditions. In these oligomers, fluorinated N‐(1,1‐dimethyl‐3‐oxobutyl)acrylamide oligomers were more effective in solubilizing phthalocyanines in methanol. Self‐assemblies formed by fluorinated oligomer‐phthalocyanine complexes are applied to the surface modifications of polystyrene (PS), and the modified PS surface exhibited not only a strong oleophobicity imparted by fluorine but also good hydrophilicity. Thus, these fluorinated molecular aggregate‐phthalocyanine systems are suggested to have high potential for new fluorinated functional materials through their excellent properties imparted by fluorine and phthalocyanines. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 521–525, 2004
Effects of four supplemental instruction programs on students' learning of gross anatomy
Authors: Forester Joseph P. , Thomas Pamela P. , McWhorter David L.
Published: April 2004

Many researchers have reported that supplemental instruction programs improve medical students' performance in various basic sciences. This study was conducted to evaluate the summative effects of four supplemental instruction programs (i.e., second‐year medical student teaching assistant program; directed study program; weekly instructor laboratory reviews; and a web‐based anatomy program) on medical students' gross anatomy laboratory practical performance. First‐year medical students from the graduating class of 2006 (n = 223) received the four supplemental instruction programs (Experimental Group). The Control Group consisted of first‐year medical students from the graduating class of 2005 (n = 254) who did not receive the four supplemental learning methods. Mann‐Whitney rank sum tests were used to compare the two groups' median percentages for the back‐upper limb (B‐UL) and the lower limb (LL) parts of a gross anatomy laboratory practical. The Experimental Group's median percentages for both the B‐UL (77.78%) and LL (83.33%) were significantly greater than that of the Control Group (B‐UL = 69.00%; LL = 81.00%; P < 0.05). Results from a post‐hoc student survey showed that more students both rated and ranked the weekly instructor laboratory reviews as extremely useful and most beneficial, respectively. A greater number of students rated and ranked the web‐based anatomy program as not useful and least beneficial, respectively. The results from this study suggest that the four supplemental instruction programs improved students' learning of gross anatomy as measured by laboratory practical performance. In addition, students most valued the additional time in the gross anatomy laboratory with the instructors. Clin. Anat. 17:322–327, 2004. © 2004 Wiley‐Liss, Inc.
Phase II study of temozolomide without radiotherapy in newly diagnosed glioblastoma multiforme in an elderly populations
Authors: Chinot Olivier‐L. , Barrie Maryline , Frauger Elisabeth , Dufour Henry , Figarella‐Branger Dominique , Palmari Jacky , Braguer D. , Hoang‐Xuan Khe , Moktari Karima , Peragut Jean‐Claude C. , Martin Pierre‐Marie M. , Grisoli François
Published: April 2004

BACKGROUND

Currently, the survival of patients age > 70 years with glioblastoma multiforme (GBM) ranges from 4 months to 6 months, although radiotherapy and/or chemotherapy may prolong survival in certain subgroups. Temozolomide is an oral chemotherapeutic agent with efficacy against malignant gliomas and a favorable safety profile. This open‐label, single‐center, Phase II study was designed to evaluate the efficacy and safety of temozolomide as first‐line chemotherapy and exclusive treatment in elderly patients with newly diagnosed GBM.

METHODS

Chemotherapy‐naïve patients (age > 70 years) were treated with temozolomide at a dose of 150–200 mg/m2 per day for 5 consecutive days of a 28‐day cycle until they developed disease progression. No radiation therapy was administered. The primary endpoint was median overall survival (OS); secondary endpoints included progression‐free survival (PFS) and toxicity.

RESULTS

Thirty‐two patients (median age, 75 years; median Karnofsky performance status, 70) experienced a median OS of 6.4 months and a median PFS of 5.0 months. Of 29 patients who were assessed for response, 9 patients (31%) achieved a partial response, 12 patients (41%) maintained stable disease, and 8 patients (28%) developed progressive disease. Adverse events primarily were mild, with NCI CTC Grade 3–4 thrombocytopenia and neutropenia reported to occur in 6% and 9% of patients, respectively. No neurotoxicity was observed. Treatment delays and dose reductions occurred in 13% and 14% of cycles, respectively.

CONCLUSIONS

Temozolomide represents a safe, easily administered, and effective therapeutic approach for elderly patients with newly diagnosed GBM. Cancer 2004. © 2004 American Cancer Society.
Gemcitabine and oxaliplatin in the treatment of patients with immunotherapy‐resistant advanced renal cell carcinoma
Authors: Porta Camillo , Zimatore Matteo , Imarisio Ilaria , Natalizi Anna , Sartore‐Bianchi Andrea , Danova Marco , Riccardi Alberto
Published: April 2004

BACKGROUND

Currently, there is no standard treatment for patients with advanced renal cell carcinoma (RCC) who do not experience a response to first‐line immunotherapy. In the current Phase II study, the authors explored the antitumor activity of a combination of gemcitabine and oxaliplatin (L‐OHP) in this setting.

METHODS

Forty‐two patients with RCC who had progressive disease following immunotherapy received gemcitabine (1000 mg/m2 intravenously on Days 1 and 8 every 21 days) and L‐OHP (90 mg/m2 intravenously on Day 1 every 21 days) for a minimum of 2 cycles before responses were evaluated. Responses to treatment and toxicity were recorded according to the Response Evaluation Criteria in Solid Tumors and the National Cancer Institute Common Toxicity Criteria, respectively.

RESULTS

No complete responses were recorded; however, 6 patients experienced a partial response (14.28%; 95% confidence interval, 5.43–28.5%), 11 patients (26.19%) had temporary stable disease as a best response, and the remaining 25 patients (59.52%) experienced progression despite receiving treatment. The median time to disease progression was 2.5 months (mean, 3.86 months; range, 1.5–11.0 months), whereas the median overall survival was 9.5 months (mean, 10.46 months; range, 4.0–22.5 months). With regard to toxicity, treatment generally was well tolerated, with only one episode of Grade 4 toxicity and expected episodes of Grade 3 toxicity, including myelosuppression and neuropathy.

CONCLUSIONS

The current results suggest that the combination of gemcitabine and L‐OHP possesses a certain level of activity and an acceptable toxicity profile in patients with immunotherapy‐resistant advanced RCC. Cancer 2004. © 2004 American Cancer Society.
Increased NF‐κB activity in B cells and bone marrow‐derived dendritic cells from NOD mice
Authors: Wheat William , Kupfer Rene , Gutches Diane G. , Rayat Gina R. , Beilke Joshua , Scheinman Robert I. , Wegmann Dale R.
Published: April 2004

Type 1 diabetes results from the breakdown of peripheral tolerance. As regulators of T cell activation, antigen‐presenting cells (APC) modulate peripheral tolerance and hence contribute to theimmune dysregulation characteristic of insulin‐dependent diabetes mellitus (IDDM). We initially observed an increased importance of NOD B cell APC function in a T cell priming assay as compared to non‐autoimmune strains. Consistent with this increased APC function, we found that NF‐κB nuclear translocation is increased in unmanipulated NOD and NOD.B10Sn‐H2b B cells and that, inaddition, NOD B cells are more sensitive to NF‐κB‐activating stimuli. We obtained similar results using NOD bone marrow‐derived dendritic cell (BMDC) cultures. As costimulatory molecules havebeen shown to be NF‐κB responsive, we examined the expression of these markers on NOD APC. Both B cells and BMDC expressed elevated levels of CD80 and CD40. Finally, NOD B cells provided better allostimulation than B cells from non‐autoimmune strains. Therefore, hyperactivation of NF‐κB and increased expression of CD80 and CD40 by NOD B cells and BMDC may be a contributing factor in the selection of effector T cells observed in IDDM.
Second Order Optical Nonlinearities of Copper(II) and Palladium(II) Complexes with N‐Salicylidene‐N′‐aroylhydrazine Tridentate Ligands
Authors: Borbone Fabio , Caruso Ugo , Centore Roberto , De Maria Antonella , Fort Alain , Fusco Michela , Panunzi Barbara , Roviello Antonio , Tuzi Angela
Published: April 2004

Three new N‐salicylidene‐N′‐aroylhydrazines tridentate ligands have been prepared: N‐4‐diethylaminosalicylidene‐N′‐(4‐nitrocinnamoylhydrazine (L1), N‐4‐diethylaminosalicylidene‐N′‐4‐(2,4‐dinitrophenylethylidene)benzoylhydrazine (L2), N‐4‐diethylaminosalicylidene‐N′‐4‐(6‐nitro‐2‐benzoxazolyl)benzoylhydrazine (L3). From these ligands, mononuclear acentric complexes of Copper(II) and Palladium(II), with pyridine as further ligand, have been prepared and characterized, also by single‐crystal X‐ray analysis. These complexes show high second order nonlinear optical activity (EFISH, |µβ| up to 3000·10−48 esu, incident wavelength 1.907 μm). The properties of metallorganic polymers obtained by grafting commercial poly(4‐vinylpyridine) with ML1 fragment (M = CuII or PdII) are also reported. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Accident history database: An opportunity
Authors: Mannan M. Sam , O'Connor T. Michael , West Harry H.
Published: April 2004

The Clean Air Act Amendments of 1990 mandated the development of regulations for the protection of workers, the public, and the environment from catastrophic releases and chemical plant accidents. As a result, the US Environmental Protection Agency (EPA) promulgated the Risk Management Program rule in June 1996. Approximately 66,000 regulated facilities are required to comply with all the requirements by June 1999 and submit a risk management plan to the EPA. Each risk management plan will contain amongst other things, a 5‐year accident history for the facility.

The 5‐year accident history database scheduled to become available to the public sometime in 1999 is potentially a very large and useful database. This presents an opportunity for determining macroscopic as well as microscopic causal factors for chemical plant accidents and then implementing these determinations for solving the underlying problems. However, there are various issues and potential pitfalls that must be kept in mind. For example, data integrity, taxonomy of the database, and the wide differences in the 66,000facilities are issues that represent challenges that require some novel approaches. The authors present their experience in analyzing EPA's accidental release information program database. The experience will guide the analysis of the 5‐year accident history database, attempting to identify the situations that commonly result in accidental chemical releases.
Pulse‐energized wet tubular electrostatic precipitator for NOx emission control
Authors: Yang Chen‐Lu
Published: April 2004

A tubular plasma reactor was used to evaluate the feasibility of oxidizing nitric oxide (NO) by corona discharge. The DC corona completely oxidized 115 ppm of NO to nitrogen dioxide (NO2) in an air stream at a voltage of 11 kV. The NO2 was further oxidized to nitrate at a voltage of 13 kV. In some cases, the residual NO2 in the effluents of the plasma reactor was removed quantitatively by absorption in aqueous causticsodium sulfite. The outlet concentrations of both NO and NO2 from the combined corona discharge and aqueous absorption system were beyond the detection limit of a chemiluminescent NOx analyzer. Both NO oxidation and NO2 absorption were confirmed in a pilot‐scale wet tubular electrostatic precipitator (WESP) that has a 4‐foot high corona discharge section and a 5‐foot high gas absorption section. The flue gas from the sewage sludge incinerator, containing 8 ppm NO and 78 ppm NO2, was tested in the system. The WESP was energized with a pulsed power supply to avoid premature spark‐over. In the plasma discharge section, 79% of the NO2 was reduced while virtually 100% of the NO was oxidized at a pulse voltage of 55 kV. The outlet concentration of NO2 from the absorption section was 2 ppm.
Metal leaching from MSW fly ash before and after chemical and thermal treatments
Authors: Iretskaya S. , Nzihou A. , Zahraoui C. , Sharrock P.
Published: April 2004

Municipal Solid Waste (MSW) incineration fly ash was collected in the industrial facilities in the city of Toulouse, equipped with recent gas scrubbing equipment which collects daily 15 t of lime treated fly ash. The fly ash contains a large proportion of water soluble chlorides, besides trace elements such as iron, zinc, titanium and copper. Presently, the fly ash is landfilled after a cement solidification process. Matrix stability and leaching behavior of heavy metals (Cd, Cu) from samples of doped MSW fly ash were examined before and after chemical and thermal treatments. A new phosphate process leading to hydroxylapatite formation is described. To evaluate it's performance as a stabilization process, cupric and cadmium ions were added as typical pollutant tracers and their distribution was studied as a function of different treatment parameters. The hydroxylapatite process used effectively removes chloride ions in the water extract and retains most of the added metal ions in the solid residues. Evaluation of this procedure as a cold process shows 50% reduction in leachable metal ions. Calcination of the solid residues at 900°C results in agglomerated particles with increased resistance to metal ion dissolution. This is attributed to heavy metal incorporation in the hydroxylapatite matrix formed during the thermal treatment. Thus, combined chemical and thermal treatments are efficient for heavy metal stabilization in MSW fly ash.
A mechanistic model for estimating VOC emissions from industrial process drains part I: The underlying channel
Authors: Olson David A. , Stubbe Justin K. , Corsi Richard L.
Published: April 2004

Recent research has indicated the potential for emissions of volatile organic compounds (VOCs) from industrial process drains, and a need for better understanding of the mass transfer kinetics associated with such emissions. In this study, a two‐zone model was developed in an effort to isolate individual mass transfer mechanisms. Zone 1, described in this paper, consists of the underlying channel in either a sealed or unsealed drain. A series of nine experiments we re completed on a laboratory drain system over a range of operating conditions to determine mass transfer parameters. Liquid‐phase mass transfer coefficients we re highly correlated with liquid flow rate for both sealed and unsealed drains. Gas‐phase mass transfer coefficients were less predictable, but were relatively constant.
A mechanistic model for estimating VOC emissions from industrial process drains part II: The water seal
Authors: Olson David A. , Stubbe Justin K. , Corsi Richard L.
Published: April 2004

This paper deals with the second of a two‐zone model developed for estimation of volatile organic compound (VOC) emissions from industrial process drains. Zone 2 consists of the trap volume in a sealed drain, where emissions were found to be affected by air entrainment and volatilization at the surface of the water seal. Emissions via bubble entrainment were influenced by the air entrainment rate and degree of chemical equilibrium (saturation). Each of these factors was correlated with process flowrate for both intact and disintegrated flow regimes. Entrained air bubbles were observed to approach a condition of chemical equilibrium exponentially with decreasing Henry's law constant.
Combustion toxics: Available data and additional needs
Authors: Siegell Jeffrey H.
Published: April 2004

With the continuing expansion of air pollution regulations there is an increasing awareness of the potential need to assess the emissions and impact of trace compounds from combustion sources in refineries and chemical plants. It has been found that these trace compounds may be emitted as the result of incomplete fuel combustion, formation of new compounds during combustion, or the presence of inorganics (e.g. metals) in the fuel. Emission factors based on field data from these sources have recently been published by both the US Environmental Protection Agency (EPA) and the American Petroleum Institute (API). The emission factors indicate that a large number of trace compounds may be emitted from combustion sources including volatiles, semi‐volatiles, PAHs, metals, and dioxins/furans. Some of these trace compounds have been classified as hazardous or toxic.

A review of the EPA and API published data sets indicates that, while there is some overlap, many gaps exist in specific source and emission types. Where gaps exist, there is a lack of confirmation for the reported emission factor. Comparison of the EPA and API emission factors for gas and fuel oil fired boilers, however, indicates reasonable agreement for several metals and some PAHs where the data overlap. EPA, however, has sampled for many more metals than API and several EPA factors for PAHs are significantly higher than reported by API. Additional tests may be warranted where there is insufficient overlap.

Much additional work needs to be done to provide reliable factors which can be used to estimate trace toxic emissions from combustion. Many gaps and inconsistencies exist in the emission factors database and changes to existing factors are expected as the database is expanded.
Using LCA for procurement decisions: A case study performed for the U.S. environmental protection agency
Authors: Schenck Rita
Published: April 2004

The U.S. EPA has developed guidance for the use of Life Cycle Assessment (LCA) for environmentally preferable purchasing. To support the guidance development, pilot studies were performed, one of which is described here. The study was performed in only four months, using simplified impact assessment methodologies. It showed that one product was environmentally preferable. This pilot demonstrated that LCA's are feasible for the purpose of purchasing decisions.
Accounting for engineering trade‐offs in corporate and public decision‐making
Authors: Stone Kenneth R.
Published: April 2004

From experience in developing and testing pollution prevention tools ranging from the opportunity assessment methodology to life cycle assessment and impact assessment, the Systems Analysis Branch (SAB) of the EPA 's National Risk Management Research Laboratory (NRMRL) has acquired a long record of lessons learned in applying these approaches for real world applications. Many of these lessons illustrate several limitations exhibited by each of these P2 approaches. For example, the pollution prevention opportunity assessment (PPOA), perhaps the most intuitive and simplest P2 tool available, is very good at identifying ways to improve operating practices, but the SAB has found several deficiencies in the PPOA 's ability to support the procurement of new equipment, products and substitute materials. Life cycle assessment, by contrast, resolves most of those deficiencies by providing a far more comprehensive picture than PPOA, but it is very complex and more expensive by at least an order of magnitude than the PPOA. Further, while each methodological approach provides information on environmental burdens, neither provides any insights on the inevitable trade‐offs that occur in performance and cost resulting from a decision. The failure to account for these trade‐offs early in the assessment may result in a decision that inadvertently creates negative impacts in performance, cost and environment.

The purpose of this article is to propose a new perspective to account for the trade‐offs inherent from making a change.
Field survey of reduced‐sulfur emissions from a modern finnish pulp mill
Authors: Järvensivu Mika , Mäenpää Tom , Jämsä‐Jounela Sirkka‐Liisa , Saari Kari
Published: April 2004

Substantial advances in air emission control technology during the last decade have brought about a decrease in reduced‐sulfur emissions from pulp mills. Un fortunately, these reduced‐sulfur compounds still cause subjective odor problems at very low concentrations. As a result pulp mills, even with efficient odor abatement systems, may produce a foul odor in the surrounding area. On the other hand, it will not be easy to further reduce the malodorous sulfur emissions at modern pulp mills because all the major emission sources have already been eliminated.

This paper presents the results of a field survey made at one of the major Finnish pulp mills. In the study, all the main emission sources we re analyzed, and the ambient air concentrations of reduced‐sulfur compounds in the area surrounding the mill we re measured. Emission rates from the current sources and measured ambient air concentrations are presented.

The effects of the main continuous emission sources on ground level concentrations are estimated by means of a Gaussian model of emission dispersion. In addition, the emission sources are ranked on the basis of the estimated ground level concentrations and the momentary emission rates. Finally, means of reducing the current continuous and occasional emissions of reduced‐sulfur are recommended.
Fate of air toxics and VOCs in the odor control scrubbers at the deer island treatment plant
Authors: Myslinski Thomas , Rhode Steven , Shilinsky Kenneth , Hunt Gary , Basu Somnath
Published: April 2004

Process off‐gases at the Deer Island wastewater treatment plant in Boston are collected and treated and its stack emissions regulated for selected gases including volatile organic compounds (VOCs), which are monitored as nonmethane hydrocarbons (NMHC). The air treatment processes of countercurrent wet oxidation scrubbing and granulated activated carbon adsorption are available for emissions control at Deer Island. In addition, since the wastewater treatment process of biochemical oxidation is fully enclosed at the site, microbial destruction of VOCs is an intrinsic treatment process for organic gases. Surveyed results of wastewater research literature indicate that the use of scrubbers for the removal of VOCs is controversial, as the fate of volatile hydrocarbon molecules across odor control scrubbers is complex and not fully understood. Continuous emission monitoring tests across the Deer Island scrubbers have consistently shown a VOC removal efficiency in excess of 50%.

The fate of the scrubber inlet VOCs at Deer Island was researched as part of a plant‐wide, on‐going VOC study. Removal efficiencies across the pure oxygen bioreactors were also investigated. Preliminary results of this study indicate chemical reactions involving VOCs in odor control scrubbers partially oxidize and chlorinate derivatives possibly destroying a fraction of the compounds by complete oxidation. In addition, VOC reduction across the enclosed aerobic bioreactors was found to be significant.

This article represents the opinions and(legal) conclusions of the authors and not necessarily those of the MWRA.
Wastewater minimization with chemical‐free water treating
Authors: Reeves Gary G.
Published: April 2004

Refineries and chemical plants generate wastewater that contains organics and dissolved minerals from incoming raw materials, and residual chemicals that are used in the processes but do not become part of the products. Using chemistry to follow trace impurities in the water collection and reuse routes can provide valuable information about the fate of these impurities. The reuse of wastewater in a facility concentrates trace impurities, which can create effluent that may not be readily treatable with conventional treatment methods.

Water balances should be used to identify opportunities to reduce water use and reduce the generation of wastewater streams. By properly evaluating treatment options for raw water, using less or no treatment chemicals, the production of wastewater can be minimized. Management techniques such as reducing or even eliminating treatment chemicals, and diverting treated and untreated wastewater for cooling tower make up or other plant applications, reduces the quantity of water disposed of as waste.

Evaluation of the use of raw materials and options to reduce or eliminate the use of chemicals in the process is compared to the cost of, and options for, disposing of concentrated wastewater.
Oxygen effects on thermophilic microbial populations in biofilters treating nitric oxide containing off‐gas streams
Authors: Lee Brady D. , Apel William A. , Smith William A.
Published: April 2004

Electricity generation from coal has increased by an average of 51 billion kWh per year over the past 3 years. For this reason cost‐effective strategies to control nitrogen oxides (NOx) from coal‐fired power plant combustion gases must be developed. Compost biofilters operated at 55°C at an empty bed contact time (EBCT) of 13 seconds were shown to be feasible for removal of nitric oxide (NO) from synthetic flue gas. Denitrifying microbial populations in these biofilters were shown to reduce influent NO feeds by 90 to 95% at inlet NO concentrations of 500 ppmv. Oxygen was shown to have a significant effect on the NO removal efficiency demonstrated by these biofilters. Two biofilters were set up under identical conditions for the purpose of monitoring NO removal as well as changes in the microbial population in the bed medium under anaerobic and aerobic conditions. Changes in the microbial population were monitored to determine the maximum oxygen tolerance of a denitrifying biofilter as well as methods of optimizing microbial populations capable of denitrification in the presence of low oxygen concentrations. Nitric oxide removal dropped to between 10 and 20% when oxygen was present in the influent stream. The inactive compost used to pack the biofilters may have also caused the decreased NO removal efficiency compared to previous biofiltration experiments. Analysis of the bed medium microbial population using environmental scanning electron microscopy indicated significant increases in biomass populating the surface of the compost when compared to unacclimated compost.
Texas NOx state implementation plan for houston‐galveston area
Authors: Grover Rajiv , Bradford Mike L.
Published: April 2004

On December 6, 2000, the Texas Natural Resource Conservation Commission (TNRCC) adopted a comprehensive Attainment Demonstration Plan, commonly referred to as the Smog Plan, to bring the Houston‐Galveston Area (HGA) into compliance with one‐hour National Ambient Air Quality Standards (NAAQS) for ground level ozone. The Federal Clean Air Act Amendments (FCAAA) of 1990 ordered HGA to meet the NAAQS for ozone, smog's main ingredient, by eliminating enough air pollution from industrial, automotive, and other sources by November 15, 2007. The TNRCC Plan calls for reducing the emissions of nitrogen oxides (NOx) by 75% and volatile organic compounds (VOCs) by 25% in the Houston‐Galveston Area. These air quality improvement measures are the toughest ever considered in Texas, and some of the toughest ever considered in the nation. The TNRCC will be performing a mid‐course evaluation, by May 2004, to revisit the level of controls adopted in the attainment demonstration plan.

The purpose of this paper is to provide information on the Smog Plan and its potential impact on a wide variety of industry sources. The reader should gain a better knowledge of the State Implementation Plan (SIP) rulemaking process and its potential impact on their day‐to‐day activities.
Photochemical treatment of a mixed PAH/surfactant solution for surfactant recovery and reuse
Authors: An Youn‐Joo
Published: April 2004

Because of their hydrophobic nature, polycyclic aromatic hydrocarbons (PAHs) are generally thought to be unavailable to in situ remediation processes, and solubilization of PAHs by surfactants is usually recommended. However, mixed PAH/surfactant solutions are wastewaters that need a post‐treatment after solubilization. In this study, mixed solutions of PAH and perfluorinated surfactant (PFS) were photochemically treated with and without hydrogen peroxide (H2O2), and the subsequent recovery and reuse of surfactant solutions were demonstrated. Phenanthrene and pyrene were selected as representative PAHs and lithium perfluorooctanesulfonate (LiFOS) as a PFS. Direct photolysis (UV only) and UV/H2O2 process enhanced the PAH degradation in LiFOS solutions compared to water. Both treatment processes selectively degraded PAHs without damaging PFS, suggesting that PFS withstands photolysis. Overall, it is demonstrated that UV and UV/H2O2 processes of mixed PAH/PFS solutions are effective for surfactant recovery/reuse, as well as PAH degradation.
Oxidation of ferrous iron by Thiobacillus ferrooxidans in a full‐scale rotating biological contactor
Authors: Nikolov L. , Karamanev D. , Dakov L. , Popova V.
Published: April 2004

The performance of a full‐scale rotating biological contactor used for the oxidation of ferrous iron by Thiobacillus ferrooxidans in drainage waters was studied. It has been shown that high volumetric rates, up to 2.5 g/Lh can be obtained. We also examined the effects of input ferrous iron concentration and liquid retention time on reactor performance. It has been shown that when the input iron concentration increased, volumetric reaction rate increased while substrate conversion decreased. In general, the rotating biological contractor is a promising tool for the biological treatment of acid mine drainage containing ferrous iron.
Low NOx burner technology for ethylene cracking furnaces
Authors: Bussman Wes , Poe Roger , Hayes Bob , McAdams Jason , Karan Jay
Published: April 2004

Regulations currently proposed for the South Texas area demand reduction of NOx emissions from combustion processes, like refining and petrochemical furnaces, to less than 10 ppm for large heat releases. A new generation of low NOx burner technology has been developed for eductor‐style, radiant‐wall burners used in ethylene cracking furnaces. These new, revolutionary burners achieve single digit NOx emission levels using an ultra‐lean premix technology. This strategy extends the stoichiometry of the fuel and air/flue gas mixture near the point of the lean flammability limit, providing NOx levels that were previously unattainable in burner designs. This paper describes the principles underlying the features of the new technology, technical objectives and strategies used to develop the burner, and test data that clearly demonstrate this technology.
CMP wastewater management using the concepts of design for environment
Authors: Yang Gordon C. C.
Published: April 2004

Application of design for environment (DfE) concepts to management of wastewater from chemical mechanical polishing (CMP) processes are presented in this paper. Today, DfE is a prevailing concept and is widely adopted by advanced nations in lieu of the traditional “command and control” approach to control waste and toxic emissions. Designing environmentally‐benign processes and products is a new and challenging frontier for engineering professionals, including those in the semiconductor industry. An insatiable need for water and subsequent wastewater treatment has imposed a chilling effect on semiconductor industry growth. It was estimated that semiconductor producers consumed more than 5.523 × 108 m3 of water in 2000. Of this amount, CMP processes accounted for 40% of the total. The CMP tool market and CMP slurry market are estimated to have 36% and 29% annual growth rates, respectively between 2000 and 2005.

Inevitably, a tremendous amount of waste slurry and post‐CMP rinse water will be generated and have to be managed properly. CMP wastewater is characterized by its high content of suspended solids having sub‐micron particle sizes, high turbidity, and high conductivity. Traditional wastewater treatment technologies, such as chemical coagulation/precipitation, do not work well for CMP wastewater, because it would generate a large volume of sludge, which might cause disposal problems in many countries, such as Taiwan. Therefore, utilizing pollution prevention principles in the design of CMP tools, development of new CMP slurries, and improved plant operations are necessary to minimize environmental damage.

Reclamation of process water is also a common requirement in the semiconductor industry. To this end, several alternatives for source reduction of CMP wastewater and water reclamation are presented in this paper.
Adsorbing colloid flotation for removal of metal ions in waters from base metal mines
Authors: Sabti H. , Brooks R. R. , Stewart R. B. , Hossain Monwar
Published: April 2004

Adsorbing Colloid Flotation (ACF) has been shown in laboratory experiments to be effective for the removal of heavy metals (Zn, Cu, Cd and Pb) from dilute solutions. Sodium dodecyl sulphate (SDS) and sodium oleate (NaOl) were used as surfactants in single or mixed form, with Fe(OH)3 as a flocculant for colloid formation. These reagents worked best for zinc and copper ions for a feed concentration of 50 parts per million (ppm). The removal of lead improved significantly by the use of Fe(OH)3 and NaLS (Sodium lauryl sulphate), while the best removal of cadmium was achieved by the use of Al(OH)3 and HTMABr (hexadecyltrimethylammonium bromide). Flotation experiments were conducted with feed concentrations of 50 and 500 parts per billion (ppb) and 50 ppm (parts per million). The experimental results showed that the residual concentration of metal ions decreased significantly with the decrease in the feed concentration. This could be the effect of excessive (much more than stoichiometric ratio) amounts of surfactant and flocculant, compared to the feed concentrations, required in the effective flotation of dilute feed solutions. The surfactant concentration and feed pH had the largest effects on the process, as observed in the case of cadmium removal. This can be attributed to the flocformation and flotation tendencies of the colloid‐metal complexes at various solution pH and surfactant concentrations. The ACF method was applied to a number of natural drainage solutions from the metal mines at Te Aroha, New Zealand, and the experimental results demonstrate that significant removal is achieved for most of the heavy metals.