bluuebunny/crossref_metadata_2025 huggingface dataset:
Exempla from Greek History in Byzantine Encomia and Historiography of the XII century
Authors: Cresci Lia Raffaella
Published: April 2004

Abstract This paper investigates the Exempla concerning ancient Greek history in Byzantine rhetorical and historiographic works of the twelfth century. The paper shows that knowledge of ancient history in this period of Byzantine literature was significant, and it reveals which ancient Greek personalities and events were preferred and which were overlooked. The paper examines the critical and encomiastic purposes of various Byzantine authors with regard to their perception of the past. The paper contributes towards an understanding of Byzantine ideology, with regard to its connections to and differences from ancient Greek culture.
Actio in Some Neo-Latin Ecclesiastical Orations
Authors: López-Muñoz Manuel
Published: April 2004

Abstract The study of theories of actio is a basic part of Rhetoric which ought not to be neglected, especially when one is considering practical rather than literary rhetoric. The present study deals with neo-Latin ecclesiastical rhetoric and points out the differences between protestant and catholic notions about the phenomenon of preaching. The presence or absence of indications of actio permits a clear distinction among tendencies in neo-Latin theory. There is such a thing as actioin the Catholic sense, but not in the Protestant. Among catholic scholars, Fr. Luis de Granada stands out for his doctrinal focus and for the quantity of his reflections on this subject.
Computer‐assisted Diabetes Education and Information Technology in Diabetes Care
Authors: Lehmann Eldon D.
Published: April 2004

This chapter overviews current applications of the use of information technology (IT) in clinical diabetes care and diabetes education. The main topics covered include (i) database systems (personal applications as well as hospital‐based systems and electronic patient records); (ii) computer‐based decision support (making use of algorithms, knowledge‐based systems, and telemedcine‐based prototypes); (iii) educational applications (including the use of simulators, games for children with diabetes, and CD‐ROM‐based diabetes teaching). Other topics addressed include obstacles to computerization, diabetes and the World Wide Web, and software evaluation. The chapter concludes that while there have been many computer prototypes developed in the field of diabetes‐IT, to date there have been relatively few successful products or applications. Reasons for this are discussed, and the need for much more rigorous program evaluation is highlighted. The chapter closes with a look to the future of possible applications of IT in clinical diabetes care.
White Electrophosphorescence from Semiconducting Polymer Blends
Authors: Gong X. , Ma W. , Ostrowski J. C. , Bazan G. C. , Moses D. , Heeger A. J.
Published: April 2004

White emission from polymer light‐emitting diodes (PLEDs) is demonstrated using semiconducting polymers blended with organometallic emitters and spin‐cast from solution. Because a single semiconducting polymer was used as the common host for red, green, and blue emission, the color coordinates, color temperatures, and color rendering indices of the white emission are insensitive to the brightness, applied voltage, and applied current density. The PLEDs have luminous efficiency of 4.3 cd A–1 and luminance of 223 cd m–2 at current density of 5.2 mA cm–2 (V = 14 V); at 17 V, L = 1.2 × 104 cd m–2.
Growth, behavior, and clinical findings in 27 patients with Kabuki (Niikawa–Kuroki) syndrome
Authors: White S.M. , Thompson E.M. , Kidd A. , Savarirayan R. , Turner A. , Amor D. , Delatycki M.B. , Fahey M. , Baxendale A. , White S. , Haan E. , Gibson K. , Halliday J.L. , Bankier A.
Published: April 2004

This study was undertaken to document the phenotype of Kabuki (Niikawa–Kuroki) syndrome in patients from Australia and New Zealand, with particular emphasis on growth patterns, behavior, and relationship between head circumference and intellectual level. Data on 27 children and adults with Kabuki (Niikawa–Kuroki) syndrome from Australia and New Zealand were collected by questionnaire and clinical assessment. The patients ranged in age from 7 months to 36 years with a mean age of 7 years and 2 months. The mean age at diagnosis was 3⅚ years, but in most cases, the facial phenotype was evident from infancy. The minimum birth prevalence was calculated at 1 in 86,000. Three of our patients died. Parents reported a behavior phenotype characterized by an excellent long‐term memory and avoidance of eye contact. No correlation was found between head circumference and severity of intellectual disability. Eight of 14 patients over the age of 5 years were overweight or obese. Six of these eight patients had failure to thrive in infancy. One patient developed insulin‐dependent diabetes mellitus in adolescence. Some individuals with Kabuki (Niikawa–Kuroki) syndrome show a characteristic growth profile with failure to thrive in infancy progressing to obesity or overweight in middle childhood or adolescence. A behavior phenotype was noted which requires further investigation. Head size is not a predictor of degree of intellectual disability. © 2004 Wiley‐Liss, Inc.
Hypertelorism, ptosis, and myopia associated with drug‐resistant epilepsy, mental delay, growth deficiency, ectodermal defects, and osteopenia
Authors: Zannolli R. , Buoni S. , Macucci F. , Miracco C. , de Santi M.M. , Piomboni P. , Bruni E. , Malandrini A. , Galluzzi P. , Hadjistilianou T. , Medaglini S. , Mazzei M.A. , Sacco P. , Terrosi‐Vagnoli P. , Volterrani L. , Molinelli M. , Burlina A.B. , Swift J.A. , Fimiani M.
Published: April 2004

We report a 30‐year‐old woman with hypertelorism, ptosis, and myopia associated with drug‐resistant epilepsy (DRE, Lennox–Gastaut syndrome), mental delay, growth deficiency, ectodermal defects, and osteopenia. To the best of our knowledge, this patient has an unusual combination of symptoms not previously described, associated with severe central nervous system dysfunction. The ectodermal defects were present in a very intriguing form, were difficult to diagnose, and did not conform to any classification or previous description. © 2004 Wiley‐Liss, Inc.
Etiology of sex differences in the prevalence of ADHD: An examination of inattention and hyperactivity–impulsivity
Authors: Rhee Soo Hyun , Waldman Irwin D.
Published: April 2004

Several studies have examined the predictions of two models (i.e., the polygenic multiple threshold (PMT) model and the constitutional variability (CV) model) developed to explain sex differences in the prevalence of attention‐deficit/hyperactivity disorder (ADHD), and the results of these studies are conflicting. Although there is substantial evidence that two distinct, moderately correlated symptom dimensions (inattention and hyperactivity–impulsivity) underlie ADHD symptoms, all of these studies have examined ADHD as a unidimensional construct. Therefore, we tested the PMT and CV models for the two ADHD symptom dimensions separately. Dizygotic twins or siblings of girls with ADHD had a higher number of ADHD symptoms than twins or siblings of boys with ADHD. This evidence for the PMT model and against the CV model was found for both inattention and hyperactivity–impulsivity, but became weaker for hyperactivity–impulsivity as symptom severity increased. © 2003 Wiley‐Liss, Inc.
Linkage and association analysis at the serotonin transporter (SLC6A4) locus in a rigid‐compulsive subset of autism
Authors: McCauley J.L. , Olson L.M. , Dowd M. , Amin T. , Steele A. , Blakely R.D. , Folstein S.E. , Haines J.L. , Sutcliffe J.S.
Published: April 2004

Autism is a complex genetic neurodevelopmental disorder in which affected individuals display deficits in language, social relationships, and patterns of compulsive and stereotyped behaviors and rigidity. Linkage analysis in our dataset of 57 New England and 80 AGRE multiplex autism families reveals a multipoint heterogeneity LOD (HLOD) score of 2.74 at D17S1871 in 17q11.2. Analysis of phenotypic subsets shows an increased HLOD of 3.62 in families with compulsive behaviors and rigidity. The serotonin transporter locus (SLC6A4) maps nearby and is considered a functional candidate gene in autism and obsessive‐compulsive disorder. We genotyped an insertion/deletion polymorphism in the promoter (5‐HTTLPR), and seven single nucleotide polymorphisms (SNPs) across the 38‐kb transcriptional unit. Transmission disequilibrium (TD) analysis reveals nominal association at a SNP in intron 5 (P = 0.02) as well as 5‐HTTLPR (P = 0.01), corresponding to over‐transmission of the short allele. TD analysis in the rigid‐compulsive subset shows no evidence for association. Intermarker linkage disequilibrium was determined. All SNPs define a single haplotype block, while 5‐HTTLPR lies 5′ to this block. Three SNPs are sufficient to detect all common alleles (≥5%) in this > 26‐kb block. Analysis of haplotypes for these markers demonstrates no evidence for association to autism. These data indicate that a common allele within the coding region of SLC6A4 is not responsible for the observed linkage. However, the presence of heterogeneous disease variants within the block or the existence of a common disease‐associated allele either upstream or downstream of this block is possible. In fact, such variants may well account for linkage to 17q11.2 in our families. © 2003 Wiley‐Liss, Inc.
μ opioid receptor gene as a candidate for the study of obsessive compulsive disorder with and without tics
Authors: Urraca N. , Camarena B. , Gómez‐Caudillo L. , Esmer M.C. , Nicolini H.
Published: April 2004

Obsessive compulsive disorder (OCD) is a complex psychiatric disease characterized by recurring obsessions or compulsions that cause significant distress to the patient. The etiology of this disorder remains largely unknown, although a genetic component has been suggested. Many candidates genes have been evaluated based on a possible serotoninergic and dopaminergic brain dysfunction. We postulate the μ opioid receptor (MOR) gene as a candidate because some observations support a role of the opioid system in OCD. The opioid antagonist, naloxone, rapidly exacerbates OCD symptoms and the opioid agonist, tramadol, was reported to be effective in the treatment of some patients. We studied two single nucleotide polymorphisms (C17T and A118G) in 51 trios with OCD. Genotyping was analyzed with transmission desequilibrium test (TDT). The allelic variant +17T of the C17T polymorphism had a low frequency (1%) in our population that did not allow for statistic analysis. However, for the allelic variant +G of the A118G polymorphism we were able to performed statistical comparisons. Our results showed a trend toward significance (χ2 McNemar = 3.6, P = 0.065) for TDT in patients with comorbid tics. It is an interesting finding that should be tested in a larger sample of OCD patients with tics. © 2004 Wiley‐Liss, Inc.
Hardness of cercopithecine foods: Implications for the critical function of enamel thickness in exploiting fallback foods
Authors: Lambert Joanna E. , Chapman Colin A. , Wrangham Richard W. , Conklin‐Brittain Nancy Lou
Published: April 2004

We evaluate the hardness of foods consumed by sympatric Cercopithecus ascanius (redtail guenons) and Lophocebus albigena (grey‐cheeked mangabeys), and consider how selection might operate to influence foraging adaptations. Since L. albigena has among the thickest dental enamel in extant primates and is commonly referred to as a hard‐object consumer, we predicted that their diet would be harder than that of the guenon. Data on diet and food hardness (as measured by resistance to puncture and crushing) were collected between June–October of 1997 at Kibale National Park, Uganda, and were compared to similar data collected in Kibale between 1991–1994. Contrary to what we predicted, there was no difference in dietary hardness when the puncture resistance of all fruit consumed by the two species was compared (31 tree species in both study periods). However, in June–October 1997, L. albigena exploited a diet more resistant to puncture and crushing than C. ascanius. This difference is largely explained by the higher percentage of bark and seeds consumed by the L. albigena during this period. We suggest that it is the difference in the mechanical properties of fallback foods during critical periods that may have served as the selective pressure for thick enamel in L. albigena. Am J Phys Anthropol, 2004. © 2004 Wiley‐Liss, Inc.
Small‐angle neutron scattering of poly(styrene)/poly(acrylic acid–ethyl acrylate) copolymers: The effect of the degree of hydrolysis of the poly(acrylic acid–ethyl acrylate) block
Authors: Crichton Mark A. , Bhatia Surita R.
Published: April 2004

We report the results of systems based on polystyrene‐poly(ethyl acrylate) (PEA) diblocks, which self‐assemble in aqueous solutions to form spherical micelles. Previous work has shown that the rheological properties of these solutions, in particular the gel–liquid transition, can be tuned through the use of a simple hydrolysis reaction to convert PEA to poly(acrylic acid) (PAA). We studied the effect of the extent of hydrolysis on the self‐assembly and micellar interactions. Small‐angle neutron scattering (SANS) spectra were fit with a variety of models to determine the micelle structure. As more PEA was converted to PAA (i.e., as the corona became more charged and more hydrophilic), the micellar aggregation number decreased, analogous to observations of other polymeric micelles. This effect could impact the gel–liquid transition and rheology in this system and in similar micellar block copolymer gels. Finally, our SANS spectra qualitatively agreed with predictions for attractive colloidal glasses, confirming the idea that the elasticity of these gels arises from the jamming of micelles. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 490–497, 2004
An electrical approach to monitor wire and cable thermal oxidation aging condition based on carbon black filled conductive polymer composite
Authors: Sun Yangyang , Fan Lianhua , Watkins Ken , Peak Jonathan , Wong C. P.
Published: April 2004

Polymeric materials are widely used as insulation and jacketing materials in wire and cable. When such materials are used for long‐term applications, they undergo thermal oxidation aging in the environment. It is necessary to develop an in situ and nondestructive condition monitoring (CM) method to follow the aging of cable materials. The main objective of this work was to investigate low‐density polyethylene/carbon black (LDPE/CB) conductive polymer composites as potential sensor materials for this purpose. LDPE/CB composites with a carbon black loading below the percolation threshold underwent accelerated thermal oxidation aging experiments. The results indicated that the substantial resistivity decreases of the LDPE/CB composites could be directly related to the increases in volume fraction of the conductive carbon black, which was mainly caused by the mass loss of polymer matrix and sample shrinkage during the thermal oxidation aging process. Compared to existing CM method based on density change, the electrical resistivity is more explicit regarding its absolute changes throughout the thermal oxidation aging. The change in resistivity spanned over four orders of magnitude, whereas the composite density only increased 10%. The results offer strong evidence that resistivity measurements, which reflect property changes under thermal aging conditions, could represent a very useful and nondestructive CM approach as well as a more sensitive method than density CM approach. Crystallinity changes in materials investigated by modulated DSC and TGA measurements indicated deterioration of crystalline regions in polymer during the thermal oxidation aging. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 513–520, 2004
Abnormal musculoaponeurotic tunnel in the arm:
Authors: Wadhwa S. , Mehra S. , Khan R.Q. , Kapur V.
Published: April 2004

Median nerve and brachial artery in the arm are not usually overlapped by any structure. Connective tissue bands and muscular slips draping or enclosing this neurovascular bundle have been reported, however, which may produce clinical symptoms of nerve compression and vascular changes. We report an unusual musculoaponeurotic band that originates as the ligament of Struthers but terminates as the brachiofascialis muscle of Wood and in the process may have entrapped both the median nerve and brachial artery. The nerve to pronator teres originates from the median nerve within this tunnel. On histological examination the nerve was flattened and showed some perineurial thickening. In view of the flexor function of brachialis muscle, this anomalous musculoaponeurotic band may be considered a clinically important entity in the causation of idiopathic neurovasculopathy in the hand. Clin. Anat. 17:360–363, 2004. © 2004 Wiley‐Liss, Inc.
CRP and IL‐6 concentrations are associated with poor glycemic control despite preserved β‐cell function during the first year after diagnosis of type 1 diabetes
Authors: Schölin Anna , Siegbahn Agneta , Lind Lars , Berne Christian , Sundkvist Göran , Björk Elisabeth , Karlsson F. Anders
Published: April 2004

Background

The role of non‐specific inflammation in β‐cell loss in type 1 diabetes is unclear. In the present study, inflammatory markers were determined in patients with newly diagnosed disease and related to β‐cell function, glycemic control and autoimmunity.

Methods

Ninety‐seven adult patients with type 1 diabetes mellitus (80% islet antibody positives, ab+) were examined at diagnosis and 3, 6, 9 and 12 months after the start of insulin treatment. Plasma C‐reactive protein (CRP), interleukin‐6 (IL‐6), C‐peptide, islet autoantibodies, insulin requirement and HbA1c were assessed.

Results

The concentrations of CRP were high‐normal at diagnosis and did not change during the study period. A positive correlation between CRP at diagnosis and BMI was observed in ab+ as well as in ab− cases. Detectable concentrations of IL‐6 were found in 32% (157/485) of the samples and did not change during the study. Ab− patients had higher values of CRP at diagnosis and throughout the study compared to the ab+. Among the ab+ patients, CRP concentrations during the study were positively correlated to C‐peptide at 12 months and an increase in HbA1c levels between 6 and 12 months. No associations between the presence or levels of islet autoantibodies and CRP were noted.

Conclusions

In type 1 diabetes, the islet destructive process and the development of β‐cell remission are not associated with changes in CRP or IL‐6. Instead, elevated CRP concentrations are prevalent and seem to reflect insulin resistance, as positive associations to BMI, C‐peptide and deterioration of glycemic control were observed. Copyright © 2003 John Wiley & Sons, Ltd.
A new type 1 diabetes susceptibility locus containing the catalase gene (chromosome 11p13) in a Russian population
Authors: Chistiakov D. A. , Savost'anov K. V. , Turakulov R. I. , Titovich E. V. , Zilberman L. I. , Kuraeva T. L. , Dedov I. I. , Nosikov V. V.
Published: April 2004

Background

Oxidative stress is involved in the origin of type 1 diabetes. Low efficiency of the scavenging antioxidant system has been shown to be related to the pathogenesis of the disease. This, therefore suggests that genes encoding catalase and other antioxidant enzymes may implicate in the development of type 1 diabetes.

Methods

Nine microsatellite markers that cover about 10 megabases around the catalase (CAT) gene on chromosome 11p13 were analyzed using polymerase chain reaction (PCR) and fluorescence‐based genotyping on an automatic DNA sequencer. We also evaluated three single‐nucleotide polymorphisms (SNP) within genes encoding catalase (T1667T and C(−262)T dimorphism) and ETS homologous factor (EHF) (C255T SNP) using a PCR‐restriction fragment‐length polymorphism approach. Multipont linkage analysis in 37 affected sibling pairs was performed using GENEHUNTER 2.1. We examined the markers for association with the disease by transmission disequilibrium tests in 57 discordant sibling pairs and by a case–control study in 258 unrelated healthy donors and 247 affected patients.

Results

We obtained close‐to‐suggestive evidence of linkage to type I diabetes, with the maximum linkage peak between markers D11S907 and D11S2008. Analysis of three SNPs at theCATandEHFgene located within the region of maximum linkage showed that T1667T and C(−262)T markers of theCATgene are strongly associated with the disease.

Conclusion

Our findings support evidence of a new putative type 1 diabetes susceptibility locus on chromosome 11p13 and suggest that theCATgene may play a role in conferring susceptibility to the disorder in Russian patients. Copyright © 2004 John Wiley & Sons, Ltd.
Inhibition of Notch signaling biases rat thymocyte development towards the NK cell lineage
Authors: van den Brandt Jens , Voss Katrin , Schott Melanie , Hünig Thomas , Wolfe Michael S. , Reichardt Holger M.
Published: April 2004

Notch receptors are involved in directing the choice between alternative cell fates in developmental scenarios such as thymopoiesis. By pharmacological interference in rat fetal thymus organ culture we show that inhibition of Notch signaling arrests T cell development at an early double‐negative stage and is accompanied by a dramatic increase in the number of NK cells. These cells show an activated phenotype, lack recombination of the TCRβ gene locus and express perforin. Similarly, in thymic lobes reconstituted with fetal liver cells, progenitors predominantly develop into NK cells both after pharmacological interference of Notch and after treatment with a recombinant rat Notch1/Fc chimera. Collectively, this identifies the lineage decision of NK/T precursor cells as an important site of Notch action in rat thymocytes.
Supercritical fluid process for removal of polychlorodibenzodioxin and dibenzofuran from fly ash
Authors: Gdbarra P. , Cogollo A. , Recasens F. , Fernandez‐Escobar I. , Abad E. , Bayona J. M.
Published: April 2004

A process is proposed for the decontamination of fly ash from an urban solid‐waste incineration facility (USWI), where the target contaminants are polychlorodibenzodioxins (PCDDs) and dibenzofurans (PCDFs), a class of highly toxic tricyclo‐polychlorinated organics. In general, the ash waste requires inertization and disposal into a controlled landfill. Here, we propose an inertization process based on the reduction of the PCDDs and PCDFs content before dumping. Inertization is brought about by extraction with a solvent consisting of supercritical carbon dioxide modified with a co‐solvent (10% toluene). The plant would run in semibatch mode, with continuous flow of fluid through a packed bed of fly ash. Then, carbon dioxide and the co‐solvent would be separated and recycled. Favorable extraction conditions were found in the laboratory at 300 bar and 60°C. Under these conditions, the removal efficiency of native PCDDs and PCDFs is around 50% refereed to the extraction of the same sample using the EPA method 1613 (Soxhlet extraction with toluene). A techno‐economic appraisal of a treatment facility is presented for a medium sized incineration plant (50,000 ton urban waste yearly) producing 1,500 ton of fly ash/y. The ash production would be inertised in a specially designed supercritical fluid (SCF) extraction unit, located on‐site at the incineration facility.
The GSA dry scrubbing technology for retrofit applications
Authors: Felsvang Karsten , Olsen Peter Bo , Jensen Flemming , Olsen John , Kumar Sam
Published: April 2004

Compliance with new legislation in Europe and United States requires retrofitting of scrubbing technology on a large number of existing waste‐to‐energy plants to control emissions of acid gases, dioxins/furans and heavy metals, especially mercury.

This paper describes the gas suspension absorber (GSA) dry scrubbing technology developed by FLS miljø a/s, Denmark. GSA is a new generation of the semi‐dry technology utilizing a circulating fluidized bed as absorber for acid gases, dioxin and heavy metals. The paper describes the GSA technology and focuses on the GSA as retrofit technology for waste‐to‐energy plants. The advantages of retrofitting the GSA upstream of an existing electrostatic precipitator are highlighted.

A description of the operating experience with GSA technology for waste‐to‐energy plants and performance test results for particulate, acid gases, dioxins and mercury removal from several European waste‐to‐energy plants is given in this paper.
Generation and disposal of petroleum processing waste that contains mercury
Authors: Wilhelm S. Mark
Published: April 2004

The origins and fate of mercury found in hydrocarbons are discussed from the perspective of waste minimization, treatment and disposal. Mercury is a common and naturally occurring component of petroleum. Petroleum processing often is accompanied by generation of waste streams that contain some mercury. These waste streams become problematic when the mercury concentration in process feeds exceeds a few ppb because of the highly toxic nature of mercury.

Waste is minimized by mercury removal systems that are now prevalent for many processes, but the main incentive to employ such systems is to protect equipment and catalysts. The removal systems have varied waste disposal consequences depending on their chemical properties and process location. Absent mercury removal systems, mercury contamination results in sludge, sediments, contaminated treatment fluids and a variety of other waste streams that must be carefully controlled, segregated and treated for disposal.

Waste containing mercury is characterized by chemical analysis that is capable of speciating the various forms of mercury and mercury compounds so as to be able to select treatment and disposal options. In many locations where the mercury concentration in process feeds is high, treatment systems for mercury are not readily available resulting in storage of toxic material for long periods of time. Both chemical and thermal treatment systems are commercially available, but access to cost effective treatment is extremely limited in the petroleum industry.
Biofiltration of asphalt emissions: Full‐scale operation treating off‐gases from polymer‐modified asphalt production
Authors: Cook Lawrence L. , Apel William A. , Gostomski Peter A.
Published: April 2004

In response to complaints from nearby residents, a biofilter was designed, installed, and tested for treating odors in one of three odorous emission streams from an asphalt plant producing polymer‐modified asphalt. Hydrogen sulfide (H2S) was determined to be the most prevalent gaseous reduced sulfur compound and was detected in the emission stream only when polymer material was being added to raw asphalt. Emission stream H2S concentrations we requite variable, ranging from 16 to approximately 30,000 ppm (v/v) and considered the likely compound contributing most to the plant's odor complaints.

The biofilter was effective in controlling odor from the production process and removed an overall average of 65% of the H2S during polymer addition, and for H2S concentrations less than 400 ppmv, re m oval averaged 98%. These removal efficiencies reflect data from the biofilter operating at 2.5‐minute empty bed residence time in 1996 and a 6.1‐minute empty bed residence time in 1997.

The biofilter's bed became increasingly acidified during the plant's 1997 operating season producing a pH gradient through the bed ranging from a high of 6.6 to a low of 3.1. The bed medium moisture content remained constant at about 60% (wet weight basis), but changes were observed in the water potential: no correlation to performance was determined. Changes in the microbial community reflected the bed acidification trend, with acidophiles becoming gene rally more numerous in the bed's deeper portions and in the mid to late season when the bed was most acidified. Bed acidification did not impact the biofilter's H2S removal efficiency.

Nearby residents we resurveyed and roughly half of the respondents indicated that the odor conditions had improved, one‐third felt odor conditions were unchanged and the remaining 15% felt odor conditions were worse despite the fact that only one of three of the plant's odorous emission streams were treated by the biofilter. Plans are to implement biofiltration for odor control at all of the facility's emission points.
Case study: Biofiltration of styrene and butylacetate at a dashboard manufacturer
Authors: McGrath Michael S. , Nieuwland Jan‐Carel , van Lith Chris
Published: April 2004

Holzindustie Bruchsal (HIB) was required to treat moderate levels of styrene emissions from their plastic dashboard manufacturing process. After evaluating many types of control technologies, HIB decided to install a Bioton biofiltration system from Monsanto Enviro‐Chem Systems Inc. (MEC). After the installation of the Bioton biofilter, HIB and MEC learned that large amounts of butylacetate were also present in the off‐gas stream. The presence of butylacetate was found to have inhibitory effects on the removal of styrene. Therefore, MEC performed a series of pilot and laboratory studies to determine if a bacteria strain could be identified that would be capable of removing styrene in the presence of butylacetate. It was found that a specific bacteria strain was capable of achieving high levels of styrene removal without inhibition from butylacetate in laboratory and pilot testing. This strain was inoculated into the full scale system. After acclimation, the full scale inoculation produced a consortium of bacteria that biologically removed the styrene from the dashboard manufacturing process in the presence of butylacetate.
Simple plant‐based design strategies for volatile organic pollutants
Authors: Narayanan Muralidharan , Erickson Larry E. , Davis Lawrence C.
Published: April 2004

Vegetation which enhances in‐situ biodegradation of organic compounds can play a key role in the bioremediation of such contaminants in polluted soils and groundwater. Plants may act directly on some contaminants by degrading them, but their main effect is to enhance microbial populations in the rhizosphere. Microbially mediated transformations are thus indirectly facilitated by root exudates which nourish the indigenous microorganisms. Plants may also be viewed as a solar driven pump‐and‐treat system which can contain a plume and reduce the spread of contaminated water.

Laboratory investigations carried out in a growth chamber with alfalfa plants provide evidence for the (microbially mediated) biodegradation of organic compounds such as toluene, phenol and TCE. Alfalfa plants tolerate concentrations of these organics in contaminated water up to 100 mg/L. They facilitate transfer of the contaminants from the saturated to the vadose zone. For volatile organic compounds such as TCE, vegetation provides a controlled release of compounds and hence assures dilution of the TCE evapotranspired into the atmosphere from contaminated soils. Using a range of calculated plausible scenarios, it is shown that intermedia transfer caused by volatilization associated with plants is most unlikely to lead to exceedance of standards for gas phase contamination, for most volatile contaminants. Possible action level exceedances might occur with highly toxic substances including vinyl chloride and carbon tetrachloride, if they are present in ground water at levels above kilogram amounts in a single plume of a few hectares, and released by vigorously growing plants under hot dry conditions. In formation needed for the calculation and design of plant‐based bioremediation systems for typical sites is discussed in this paper.
Process system optimization for life cycle improvement
Authors: Marano John J. , Rogers Shelby
Published: April 2004

Life Cycle Assessment (LCA) is an analytic tool for quantifying the environmental impacts of all processes used in converting raw materials into a final product. The LCA consists of three parts. Life cycle inventory quantifies all material and energy use, and environmental emissions for the entire product life cycle, while impact assessment evaluates actual and potential environmental and human health consequences of the activities identified in the inventory phase. Most importantly, life cycle improvement aims at reducing the risk of these consequences occurring to make the product more benign. When the LCA is performed in conjunction with a technoeconomic analysis, the total economic and environmental benefits and short comings of a product or process can be quantified. A methodology has been developed incorporating process performance, economics, and life cycle inventory data to synthesize process systems, which meet life cycle impact‐improvement targets at least cost. The method relies on a systematic description of the product life cycle and utilizes successive Linear Programming to formulate and optimize the non‐linear, constrained problem which results. The practicality and power of this approach have been demonstrated by examining options for the reduction of emissions of the greenhouse gas CO2 from petroleum‐based fuels.
Odor control in semiconductor manufacturing facilities
Authors: Muller Christopher O. , Joyce Charles Thane , Poppre Michael N.
Published: April 2004

Throughout the semiconductor industry, the need for controlled atmospheres ‐ free from contaminant gases ‐ for manufacturing processes is no longer just a worrisome concern ‐ it has become a critical reality. Manufacturers have now fully recognized the fact that sensitive electronic components and electrical equipment will be damaged if they are exposed to airborne chemical contamination. More importantly, however, is the recognition that the health and safety of workers can be seriously compromised by over exposure to these same contaminants ‐ many of which are toxic to humans.

The total organic chemical concentrations in recirculated air are relatively high in semiconductor clean rooms when comp a red to outdoor or supply air. Low ‐ level exposures to a variety of toxic materials commonly occur from minor leaks and spills as well. Thus, the combined effects of chemical exposures, whether additive or synergistic, are very important. The work ‐ loss rates reported by this industry support many workers' assertions that occupational exposures to chemicals, gases, and other toxic materials commonly occur.

Whereas subjective odor measurements are commonly used to initiate many indoor air quality (IAQ) investigations in commercial buildings, this same subjective criteria is many times used as the basis for initiating an evacuation in semiconductor manufacturing facilities. Because of the toxic and hazardous nature of many of the chemicals used in these operations, the detection of even the slightest odor, whether it comes from a leaking process line or a truck parked at the loading dock, may be enough to shut down a manufacturing facility for fear of worker safety.

This paper presents odor control issues in semiconductor manufacturing operations from the perspective of employee safety and health, design engineering, and the selection and application of one type of odor control system.
Life cycle assessment: An international experience
Authors: Curran Mary Ann
Published: April 2004

Life Cycle Assessment (LCA) is used to evaluate environmental burdens associated with a product, process or activity by identifying and quantifying relevant inputs and outputs of the defined system and evaluating their potential impacts. This article outlines the four components that comprise LCA (goal definition, inventory, impact assessment and interpretation) and addresses various applications of LCA within industry and government. Included are references to several resources that may be used to better understand and apply LCA, such as books, journals, software programs and internet websites.
The use of life cycle analysis within the U.S. department of energy
Authors: Curlee T. Randall , Yuracko Katherine L.
Published: April 2004

The U.S. Department of Energy's (DOE's) decisions regarding D&D, waste management, and the selection of technologies for R, D&D are extremely complex. Historically, DOE decisions were based primarily on meeting near‐term goals. There is evidence that some of those decisions were not optimal in terms of minimizing costs or in terms of minimizing overall environmental and health impacts. Fortunately, DOE is currently embracing the principles of life cycle analysis (LCA) in its decision‐making. The results indicate that DOE is making better decisions since implementing the principles of LCA. This paper discusses LCA from the perspective of DOE and reviews several specific examples of the use of LCA by DOE.
In‐Situ ozonation of contaminated groundwater
Authors: Nimmer Michael A. , Wayner Brian D. , Allen Morr A.
Published: April 2004

This paper presents case studies in the application of insitu ozone sparging to remediate petroleum contaminated groundwater. This technology was developed and installed due to shortcomings with other conventional remedial technologies evaluated for groundwater remediation. The main objective of this study was to develop a system to supply ozone to the groundwater aquifer and to evaluate the system performance in the field. Three different applications were evaluated for this study, all containing petroleum‐contaminated groundwater.

The ozone sparging system consists of an air compressor, ozone generator, a programmable logic controller, and associated gauges and controls. The mixture of air and ozone is injected into the groundwater aquifer through microporous sparge points contained in various sparge well designs.

The initial results from the three applications demonstrated that ozone sparging is a viable alternative to remediate petroleum ‐contaminated groundwater. Significant reductions in petroleum constituents we re observed shortly after system start‐up at all sites. During the one to two years operation at the three sites, a number of maintenance items we re identified; these items we re addressed by modifications to the system design and operation. A long‐term evaluation of the system operation has not yet been performed.
Conversion of soil remediating incinerators into industrial waste incinerators
Authors: Acharya Prakash , Hay George H.
Published: April 2004

Soil Remediating Incinerators (SRIs) in the United States (US) were primarily deployed at United States Environmental Protection Agency (USEPA) Superfund sites and sometimes at commercial sites in the last two decades. The remediation of these sites by incineration seemed to peak in the late 1980's and early 1990's. The decline in the use of these incinerators is due to changing economics (price per ton of soil processed), challenges in the system permitting and siting, competing technologies (such as high capacity direct and indirect‐fired Thermal Desorption Systems), and the incorrect public perception that these systems endanger human health and pollute the environment. Many of these sophisticated, well‐proven transportable units are currently idle while applications for them are being sought. Since the domestic market has changed, leading companies have started converting these units into Indus trial Waste Incinerators (IWIs) for international deployment.

The primary issues for conversion are economic, regulatory and technical. The economic aspects include country‐specific project financing issues and the sometimes high costs of retrofitting existing systems. Regulatory issues include stack gas, ash and wastewater discharge criteria. Some Asian and Latin American countries have more stringent criteria than those in the US, requiring expensive upgrade of air pollution controls. The technical challenges of waste preparation and feed systems for multiple‐feed IWIs are significantly greater than those of single feed soil remediation systems. The waste feeds for IWIs are typically received in bulk shipments, tankers and drums; their physical proper ties present a variety of material handling challenges; and their compositions represent a wide range of complex waste profiles that further complicate meeting stringent discharge criteria. These issues, opportunities and challenges associated with conversion are discussed in this paper. Available data on the feed characteristics and performance of IWIs are also presented.
Membrane separation in solvent lube dewaxing
Authors: Gould Ronald M. , White Lloyd S. , Wildemuth Craig R.
Published: April 2004

Exxon Mobil Corporation and W.R. Grace have developed an enhanced process for recovering solvents used in the refining of lubricants. The membrane‐based process provides higher yields of lube oil, while simultaneously consuming less energy, decreasing cooling water use, and potentially reducing the level of volatile organic emissions from the dewaxing operation. The yield increase equates to a process savings, for a typical commercial plant, of about 2 million barrels of crude oil per year. By recovering and recycling the dewaxing solvent while bypassing the energy intensive parts of the plant, a single facility could reduce fuel oil consumption by 36,000 barrels/year, and greenhouse gas emissions by about 20,000 tons/year for each plant. The same plant would reduce cooling water use by nearly 4 million gallons/day, and, the release of dewaxing solvents, which are volatile organic materials, could be decreased by 50–200 tons/year per plant depending on the mechanical condition of its equipment. This technology was first implemented commercially at Exxon Mobil's Beaumont, Texas, Refinery. It can be easily retrofitted into existing plants or incorporated into new plant designs, and is currently available for license as the trademarked process MAX‐DEWAX®.
Polymeric composite ultrafiltration membranes for non‐aqueous applications
Authors: Peinemann K.‐V. , Ebert K. , Hicke H.‐G. , Scharnagl N.
Published: April 2004

Chemically and thermally resistant membranes suitable for the separation of low molecular weight substances from organic solvents were developed. Porous membranes from polyacrylonitrile and polyamideimide were optimized for this application. Cellulose ethers, like hydroxypropylmethylcellulose (HPMC) and polyether‐block‐polyamides, were used as selective coatings. Special attention was paid to the separation of edible oil/solvent mixtures. Composite membranes with 99% oil retention could be prepared with HPMC as selective layer.
A computational model for heterogeneous flow through low headloss biofilter media
Authors: Chitwood Derek E. , Devinny Joseph S. , Meiburg Eckart
Published: April 2004

In an ideal biofilter, air flows parallel to the biofilter axis and at the same velocity through all parts of the bed. In contrast, non‐uniform flow causes different parcels of air to experience detention times above or below the average, reducing treatment efficiency. Designers and operators have long been aware that medium nonuniformity, bed compaction, fissuring, and separation from the vessel walls can cause flow channeling and damage biofilter performance. However, as biofilters have been designed for lower headloss and higher flowrates, flow heterogeneity has also arisen, as pressure variation in the headspace affects flow in the medium.

In an effort to investigate flow heterogeneity, a two‐dimensional steady‐state computational fluid dynamics (CFD) model was developed to simulate flow through a typical biofilter. The model assumes incompressible, two‐dimensional, Navier‐Stokes flow in the spaces above and below the bed and Darcy flow in the porous medium. The modeling effort demonstrated that the optimal design depends on the permeability of the medium, the air flowrate, and biofilter configuration. Several simple options for inlet and outlet location were compared. In very low permeability media, the flow was uniform regardless of the design. With highly permeable media, the optimal design choice depended on the Reynolds number. However, the design with side inlet and same side outlet had the lowest flow heterogeneity of the five designs over a wide range of Reynolds numbers. The model also demonstrated that removal efficiency decreases as flow heterogeneity increases.
Evaluation of continuous flow‐through phytoreactors for the treatment of TNT‐contaminated water
Authors: Medina Victor F. , Larson Steven L. , McCutcheon Steven C.
Published: April 2004

The proof of concept for created wetlands to treat groundwater or industrial water contaminated with trinitrotoluene (TNT) was established using bench‐scale, continuous flow reactors with aquatic plants. Contaminant loadings from 0.0132 to 2.488 g/m3/day were tested on phytoreactors using parrotfeather (Myriophyllum aquaticum) as the plant. Reactor removal efficiency and elimination capacity were linearly related to the load of TNT. An algal reactor was also tested at a loading of 0.9671 g/m3/day and removed 93% of the TNT. Some removal was also found in control reactors that contained no plants and minimized algal growth by shielding them from light. However, the removal efficiencies in the controls were much lower. Transformation products, aminodinitrotoluenes (ADNT) and diaminonitrotoluenes (DANT), were detected in the algae and phytoreactors, but not in the controls, indicating that the TNT was being transformed. However, ADNT persisted in the effluent, representing a reactor‐design issue that must be further investigated. ADNT concentrations in the plant material increased with contaminant loading. TNT was only found in plant tissue at the highest loading of 2.488 g/m3/day. Higher concentrations of ADNT were found in the root of the plant, with approximately equal concentrations in the stem and leaf portions. Ratios of 4‐aminodinitrotoluene (4ADNT) versus 2‐aminodinitrotoluene (2ADNT) were higher in the water phase versus what was found in plant material. Because microbial processes tend to favor the formation of 4ADNT, the higher ratio suggests that the removal of TNT is actually a combination of microbial and phyto processes.
Pilot‐scale in situ bioremediation of gasoline‐contaminated groundwater: Impact of process parameters
Authors: Nakhla George , Niaz Mohammed
Published: April 2004

This study evaluated the impact of groundwater velocity and dissolved oxygen (DO), added as hydrogen peroxide to overcome oxygen solubility limitations, and contaminant concentrations, on the efficiency of an engineered in situ bioremediation (ISB) strategy to treat groundwater contaminated with benzene, toluene, and xylene (BTX). BTX served as model compounds of gasoline contamination. Groundwater velocities of 1, 2, and 4 m/d were studied. At each velocity, two concentrations of BTX were employed—10 and 50 mg/l of each of the contaminants to reflect “hot spot” conditions following a spill or major leak. Similarly DO:BTX mass ratios of 1.5:1 and 3.2:1 were employed.

The results of the study indicated that BTX removal efficiencies of 96.7 to 99.7% were achievable at a groundwater velocity of 1 m/d with final concentrations reaching as low as 30 μg/l. BTX removal efficiencies decreased to 70 to 85 percent at a velocity of 2 m/d, and to 37 to 53% at a velocity of 4 m/d. At any given groundwater velocity, BTX removal efficiencies generally increased with increasing DO and BTX concentrations. Mathematical equations for the first‐order biodegradation rate coefficients as a function of the three parameters were derived. Statistical analysis of the data revealed that groundwater velocity was the most significant parameter impacting biodegradation efficiency, accounting for approximately 80% of the variability. Hydraulic conductivity of the aquifer decreased by approximately 80% over the course of the seven‐month study, with 90% of the decline occurring within the first six weeks. Plate counts also impacted hydraulic conductivity. However, it was not possible to model hydraulic conductivity by plate counts only.