bluuebunny/crossref_metadata_2025 huggingface dataset:
Is Atopy Related to Neuroticism, Stress, and Subjective Quality of Life?
Authors: Radošević-Vidaček Biserka , Košćec Adrijana , Bakotić Marija , Macan Jelena , Bobić Jasminka
Published: March 2009

Is Atopy Related to Neuroticism, Stress, and Subjective Quality of Life?

Different psychosocial characteristics have been associated with allergic disorders. The aim of this study was to examine whether atopic constitution and reports of allergic symptoms were related to personality trait of neuroticism, exposure to stressful life events and estimates of quality of life. Atopy was determined by skin prick test and reports of nasal and pulmonary allergy-related symptoms. Actively working individuals of both genders took part in the study (n=145, age range: 20 to 66 years). The participants were divided in three groups. The first group was composed of those with negative skin prick test and without symptoms (n=57), the second of those with positive skin prick test but without symptoms (n=28), and the third of those with positive skin prick test and symptoms (n=60). The groups did not differ significantly in neuroticism, exposure to stressful life events, or quality of life. Women reported more pronounced neuroticism and anxiety, higher exposure to stressful life events, and were less satisfied with their environment than men. In our sample of active workers we found no association of neuroticism, exposure to stressful life events, and quality of life with atopy and allergic symptoms.
Andrija Štampar and the Institute for Medical Research and Occupational Health
Authors: Šarić Marko
Published: March 2009

Andrija Štampar and the Institute for Medical Research and Occupational Health
Frontotemporal Dementias: Update on Recent Developments in Molecular Genetics and Neuropathology
Authors: Liščić Rajka
Published: March 2009

Frontotemporal Dementias: Update on Recent Developments in Molecular Genetics and Neuropathology

Frontotemporal dementias (FTD) are the second most common type of presenile dementias, considered to be clinically and pathologically different from Alzheimer's dementia (AD). FTD differs clinically from AD because memory loss is rarely an early symptom. Instead, FTD is usually denoted by behavioural and language difficulties, and may co-occur with motor neuron disease (MND). Frontotemporal lobar degeneration (FTLD) with ubiquitin-positive, tau-negative inclusions (FTLD-U) is the most common underlying pathology with and without MND. TAR DNA-binding protein 43 (TDP-43), encoded by the TARDBP gene, has been identified as the major pathological protein of FTLD-U with or without MND, demonstrating that abnormal TDP-43 alone is sufficient to cause neurodegeneration. FTLD is a genetically complex disorder. A proportion of cases of FTLD-U have various pathogenic mutations in the progranulin (GRN) gene. Other FTLD-U entities with TDP-43 proteinopathy include FTLD-U with valosin-containing protein (VCP) gene mutation and FTLD with MND linked to chromosome 9p. In contrast, chromosome 3-linked dementia, a FTLD-U with chromatic modifying protein 2B (CHMP2B) mutation, has TDP-43 negative inclusions. Thus, TDP-43 defines a novel class of neurodegenerative diseases called TDP-43 proteinopathies. These recent discoveries will contribute to an accurate diagnosis, and facilitate the development of diagnosis and therapy.
Clinical dental examinations of 357 donkeys in the UK. Part 1: Prevalence of dental disorders
Authors: du TOIT N. , BURDEN F. A. , DIXON P. M.
Published: March 2009

Reasons for performing study: Dental disorders have a high prevalence in older donkeys and horses, but the nature and pathogenesis of many of these disorders have yet to be established.

Objectives: The identification and determination of the prevalence of important dental disorders in different age groups in a large single population of donkeys, to establish a better understanding of the nature and pathogenesis of these disorders.

Methods: A prospective cross‐sectional study was performed on the donkey population at The Donkey Sanctuary with detailed oral examinations of 357 donkeys within 7 different age groups (age range 2–53 years) recorded.

Results: The prevalence of dental disease in all donkeys was 73%, increasing in prevalence from 28% in the youngest to 98% in the oldest age group. There was an increase in prevalence of commonly recognised dental disorders with increasing age, such as: diastemata (3.8% in youngest to 86% in oldest group); missing teeth (0–56%); overgrown teeth (15–86%); worn teeth (8–84%); displaced teeth (0–38%); and periodontal disease (0–28%).

Conclusions: There was a significant increase in the prevalence of dental disorders with increasing age with the largest significant increase for most dental disorders occurring in the 15–20 year age group.

Potential significance: Most dental disorders significantly increase in prevalence in the 15–20 year age group and, therefore, prophylactic geriatric dental treatment in donkeys should be commenced from age 15 years.
Diffusion of contrast medium after perineural injection of the palmar nerves: Anin vivoandin vitrostudy
Authors: NAGY A. , BODO G. , DYSON S. J. , SZABO F. , BARR A. R. S.
Published: March 2009

Reasons for performing study: Proximal diffusion of local anaesthetic solution after perineural anaesthesia may lead to the desensitisation of structures other than those intended. However, there is no evidence‐based study demonstrating the potential distribution and diffusion of local anaesthetic solution after perineural analgesia in the distal limb.

Objective: To document the potential diffusion of local anaesthetic solution using a radiopaque contrast model and to evaluate the influence of walking compared with confinement in a stable after injection.

Methods: Radiopaque contrast medium was injected subcutaneously over one palmar nerve at the base of the proximal sesamoid bones in 6 nonlame mature horses. Horses were assigned randomly to stand still or walk after injection. Radiographs were obtained 0, 5, 10, 15, 20 and 30 min after injection and were analysed to determine the distribution and diffusion of the contrast medium.

Results: In 89% of injections an elongated pattern of the contrast medium was observed suggesting distribution along the neurovascular bundle. After 49% of injections a fine radiopaque line extended proximally from the contrast ‘patch’, and in 25% of injections a line extended distally. There was significant proximal and distal diffusion with time when sequential radiographs of each limb were compared. The greatest diffusion occurred in the first 10 min. Walking did not significantly influence the extent of either proximal or distal diffusion.

Conclusions and potential relevance: Significant proximal diffusion occurs in the first 10 min after perineural injection in the distal aspect of the limb and should be considered when interpreting nerve blocks. Distribution of local anaesthetic solution outside the fascia surrounding the neurovascular bundle or in lymphatic vessels may explain delayed or decreased effects.
Bone biomarkers and risk of fracture in two‐ and three‐year‐old Thoroughbreds
Authors: JACKSON B. F. , DYSON P. K. , LONNELL C. , VERHEYEN K. L. P. , PFEIFFER D. U. , PRICE J. S.
Published: March 2009

The aim of this study was to determine whether bone biomarkers (osteocalcin, PICP, ICTP and CTX‐I) could be used to identify 2‐ and 3‐year‐olds at increased risk of fracture in the subsequent flat racing season. It was concluded that these bone biomarkers cannot be used to identify 2‐ and 3‐year‐olds that sustain a fracture. Whether bone biomarkers have better predictive value in older horses or when measured serially in the same animal remains to be determined.
Exploring the significance of the fluidized flow regime for avalanche hazard mapping
Authors: Issler Dieter , Gauer Peter
Published: March 2009

Observational and experimental evidence suggests that it is important to explicitly account for the fluidized flow regime in avalanche hazard mapping due to its high mobility, intermediate density and high velocity. We explore the differences from conventional runout modelling by implementing an extension of the Norem–Irgens–Schieldrop (NIS) rheology in a simple mass-point model. When the dispersive stresses and the excess pore pressure equal the overburden pressure, the flow height increases and the density diminishes until a new equilibrium is reached, determined by the different density dependencies of the two parameters of the dispersive stresses. Fluidization requires sufficiently steep terrain; when it occurs it leads to substantially higher velocities than compared to the dense-flow regime. The model parameters are strongly constrained by their physical meaning and vary little between widely different avalanches. However, in all test cases we obtained better agreement between simulated and observed runout distances and pressure effects than with conventional models.
Influence of Sewage Sludge and Nitrogen Fertilization on Growth, Nutrient Content and Heavy Metal Uptake by Rice Straw
Authors: Kabir MK , Ullah SM , Jahan S , Ullah M Bashir , Kamal ATMM
Published: March 2009

A pot experiment was conducted to study the effects of sewage sludge and nitrogen fertilization on the growth, yield, nutrient and heavy metal uptake into rice straw (Oriza setiva L cv. BRRI dhan-36). There were five 5 treatments (T0, T1, T2, T3 and T4) consisting of 5 levels of sewage sludge (0, 60, 120, 200 and 300 t/ha) and 5 levels of nitrogen (280, 49, 35, 28 and 21 kg/ha). In the experiment the highest height of the rice plant (97.33 cm per plant) and number (55.00) of tillers per four plants were recorded with the treatment, 300 t/ha sewage sludge plus 21 kg/ha nitrogen. The length of spikelet was significantly high in all treatments compared to the treatment, 300 t/ha sewage sludge plus 21 kg/ha nitrogen. On the other hand, both the fresh and dry weight of rice straw was significantly high in the aforesaid treatment compared to the other treatments. The contents of N, K, Na, Ca, Mg, Fe, Cu, Zn and Pb in rice straw increased significantly with increasing sewage sludge levels and were observed high at the treatment, 300 t/ha sewage sludge plus 21 kg/ha nitrogen, but the amount of P and Mn uptake decreased significantly with increasing sewage sludge levels showing an antagonistic effect. Cr, Cd and Ni contents were below detectable level. Key words: Sewage sludge, Fertilization, Rice straw, Nutrient, Heavy metal Â  doi: 10.3329/bjsir.v43i4.2248 Bangladesh J. Sci. Ind. Res. 43(4), 571-580, 2008
DEVELOPING THE COMPOSED PROBABILITY MODEL TO PREDICT HOUSEHOLD TRIP PRODUCTION (A CASE STUDY OF ISFAHAN CITY)
Authors: Khaki Ali Mansour , Afandizadeh Shahryar , Moayedfar Reza
Published: March 2009

Household trip production is not a constant parameter and vary based on socio‐economic characteristics. Even households produce several numbers of trips in each category (households with constant socio‐economic characteristics). The purpose of the present study is to model a variation of household trip production rate in statistical societies. To achieve the purpose, a concept of Bayesian Inference has been used. The city of Isfahan was selected as a case study. First, the likelihood distribution function was determined for average household trip production. Then, likelihood distribution was determined for the numbers of household trips separating odd and even trips. In order to increase the precision of the function, the concept of Bayesian inference was utilized. To insert household socio‐economic variables in the function, the disaggregate model was calibrated for average household trip production. Statistical indices and χ2 test show that the likelihood distribution function of average household trip production follows the gamma distribution and the numbers of household trip production follows the poisson distribution. The final composed probability distribution was determined on the basis of Bayesian inference. The related function was created with a compilation of the mean parameter distribution function (gamma distribution) and the numbers of household trip production (poisson distribution). Finally, the disaggregate model was inserted to the final composed probability function instead of the mean parameter. The obtained results show that the use of Bayesian inference method would open up the possibility of modeling the variation of household trip production rate in statistical societies. Also it would be possible to insert socio‐economic characteristics in the model to predict the likelihood of real produced trips for each category of household.
ALLOTMENT BOOKING IN INTERMODAL TRANSPORT
Authors: Jaržemskienė Ilona , Jaržemskis Vytautas
Published: March 2009

The article presents a valuable concept seeking to solve the problem of demand uncertainty in intermodal transport. Regular traffic is quite important for moving containers, trailers and swap bodies. To keep regularity with uncertain demand means to have backlogs or empty space. Both of them are inefficient from an economical point of view. In practice, a day‐by‐day demand forecast is meaningful only for the next two or three days. This poses serious allotment management problems to freight forwarders and shippers since long‐term contract allotments need to be planned many months ahead. The article presents a stochastic dynamic programming model for a short‐term allotment planning a model that would be very valuable for implementing intermodal solutions. The presented model evaluates optimal cost policy based on the economic trade‐off between the cost of backlogged shipment and the cost of acquiring additional allotment.
Actualidad y futuro de la fenomenología. Una perspectiva hispanoamericana
Authors: Niel Luis
Published: March 2009

El presente artículo ofrece una perspectiva personal y singular sobre la actualidad intelectual de la fenomenología. Dentro de este marco se rescatan y subrayan algunos motivos centrales que originaron la fenomenología y sobre los cuales se funda. En función de dichas motivaciones, se la presenta como descripción de lo propio, de la propia experiencia, para ulteriormente extraer de allí una consecuencia fundamental: escribir en nombre propio, más allá de las referencias bibliográficas y de remisiones a autores o pensadores determinados. A partir de esto, el análisis muestra la articulación de la descripción de lo propio con la escritura de o desde lo propio, y la responsabilidad que aquí se hace patente y que conlleva el pensar fenomenológico. De este modo, se abre un ámbito que, más allá de la descripción, comporta asimismo un intento de exceder lo dado para adentrarse en lo por-venir y en las perspectivas que conducen a pensar lo posible. Por último, se aborda brevemente el tema del lenguaje propio, en este caso concreto, el español, y su relación con los idiomas académicos institucionalizados internacionalmente, formulando algunas preguntas sobre la relación entre la producción en fenomenología y su escritura en español.
Sobre a Stimmung: biranismo e fenomenologia
Authors: Umbelino Luís António
Published: March 2009

Marc Richir ha mostrado en obras recientes la importancia de un análisis fenomenológico de las relaciones complejas entre fantasía, imaginación y afectividad, a fin de descifrar nuestra “demasiado humana” naturaleza. La terra incognita que se deja contemplar desde tal encrucijada de conceptos es difícil de analizar y plantea el reto de comprender que no podemos “medir” nuestra “condición humana” sin tomar en consideración las dimensiones imaginativas y afectivas, las fronteras de la razón, los puntales de la institución simbólica, la presencia savage y no perceptible de la Stimmung. En este particular contexto no es un detalle, a nuestro parecer, la referencia hecha por Richir a Maine de Biran; pues él cree que Biran es el filósofo que “mejor que ningún otro, y mucho antes de Heidegger” comprendió y analizó con mayor rigor las singulares características de esta terra incognita (“continente perdido”, dice Biran) de la Stimmung, de las tonalidades, variaciones y erupciones, afectivas. Este ensayo pretende subrayar los puntos fundamentales de la posición de Richir al respecto, pero también, y sobre todo, mediar en la contribución de Maine de Biran a la comprensión de la tonalidad siempre bizarra que baña al mundo cuando nos aparece en su Jemeiningkeit.
Nietzsche y el olvido animal
Authors: Lemm Vanessa
Published: March 2009

Este ensayo presenta una lectura de la segunda Consideración intempestiva y del segundo ensayo de La genealogía de la moral que revaloriza la importancia del olvido animal en la concepción de la historia y de la política propuesta por Nietzsche. En mi interpretación, el reconocimiento del valor del olvido animal permite a Nietzsche redefinir la memoria como una fuerza artística y la historiografía como un arte de la interpretación. Este artículo conecta esta intuición con la relación entre política y promesa establecida por Nietzsche en el segundo ensayo de La genealogía de la moral, argumentando que el descubrimiento del valor del olvido animal permite a Nietzsche redefinir la esfera de la política como una esfera en la cual la animalidad del ser humano pude tomar un rol creativo y productivo ejemplificado por la promesa del individual soberano en vez de ser considerado como un objeto de dominación y explotación.
Tetrasomy 13q mosaicism associated with phylloid hypomelanosis and precocious puberty
Authors: Dhar Shweta U. , Robbins‐Furman Patricia , Levy Moise L. , Patel Ankita , Scaglia Fernando
Published: March 2009

Various forms of pigmentary dysplasias have been known to be associated with chromosomal mosaicism. One of these disorders, known as phylloid hypomelanosis, has been found to be predominantly associated with abnormalities in chromosome 13. Most of the reported literature involves mosaic trisomy 13 with clinical evidence of abnormal pigmentation in the form of leaf‐like or oblong achromic macules following Blaschko's lines. Here, we report on an 8‐year‐old girl with phylloid hypomelanosis and precocious puberty who was found to have mosaicism for tetrasomy 13q in the form of inverted dup(13)(q21) on her skin fibroblasts as well as peripheral blood karyotype. A higher resolution (244K) chromosomal microarray was done on DNA from skin fibroblasts confirming the breakpoint and gain of distal 13q, which made her tetrasomic for 13q21‐qter. This is the first‐ever reported association of tetrasomy 13q with phylloid hypomelanosis and precocious puberty. Our report further emphasizes the need to exclude any type of abnormalities of chromosome 13 in patients with phylloid hypopigmentation. © 2009 Wiley‐Liss, Inc.
Positive association between the brain‐derived neurotrophic factor (BDNF) gene and bipolar disorder in the Han Chinese population
Authors: Xu Jie , Liu Yun , Wang Peng , Li Sheng , Wang Yabing , Li Jun , Zhou Daizhan , Chen Zhuo , Zhao Teng , Wang Ting , Xu He , Yang Yifeng , Feng Guoyin , He Lin , Yu Lan
Published: March 2009

Brain‐derived neurotrophic factor (BDNF) is the most widely distributed neurotrophin in the central nervous system (CNS), and services many biological functions such as neural survival, differentiation, and plasticity. Previous studies have suggested that the Val66Met (also known as rs6265 or G196A) variant of BDNF is associated with bipolar disorder (BPD), but the results have been inconclusive. We therefore genotyped the Val66Met polymorphism in a Han Chinese population sample (498 cases and 501 control subjects). We found that the BDNF genotype is associated with BPD in this population (χ2 = 9.4666, df = 2, P = 0.00884). Furthermore, our data suggested that the Met allele rather than the Val allele increased the risk for BPD in our Han population (OR = 1.44; 95% CI = 1.070–1.950; P = 0.016). Further studies are necessary to elucidate the involvement of the BDNF gene in the pathophysiology of BPD. © 2009 Wiley‐Liss, Inc.
Chirality Change of Chloronitrobenzene on Au(111) Induced by Inelastic Electron Tunneling
Authors: Simic‐Milosevic Violeta , Meyer Jörg , Morgenstern Karina
Published: March 2009

Chiralitätschamäleon: Durch inelastisches Elektronentunneln lassen sich einzelne Chlornitrobenzol(ClNB)‐Moleküle, die in zufälliger Verteilung auf Au(111) adsorbiert wurden, in eine gewünschte enantiomere Form (r oder l, siehe STM‐Bilder und Kugel‐Stab‐Modelle) und einen bestimmten Rotationszustand überführen. Weil sich die Schwellenspannungen für den Wechsel der Chiralität (260 mV) und die Rotation (380 mV) deutlich unterscheiden, können beide Prozesse getrennt ausgelöst werden.

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Direct anti‐Selective Catalytic Asymmetric Mannich‐Type Reactions of α‐Ketoanilides for the Synthesis of γ‐Amino Amides and Azetidine‐2‐amides
Authors: Xu Yingjie , Lu Gang , Matsunaga Shigeki , Shibasaki Masakatsu
Published: March 2009

Breaking with convention: A homodinuclear nickel complex derived from a biphenyldiamine‐based Schiff base catalyzed an anti‐selective Mannich‐type reaction of α‐ketoanilides (see scheme) to afford unique building blocks for the synthesis of azetidine‐2‐amides and α‐hydroxy γ‐amino amides. This approach stands in contrast to conventional Mannich‐type reactions for the synthesis of β‐amino carbonyl compounds. o‐Ns=o‐nitrobenzenesulfonyl.

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Antiquarian teratology books available in reprint form
Authors: Beckwith J. Bruce
Published: March 2009

Several reprint editions of antiquarian books dealing with malformations have been published in recent years, but their existence is not widely known. Original editions of these works are rare, expensive, and not available in most institutional libraries, which makes these reprints especially welcome. Several currently available works of potential interest to teratologists are described and critiqued. Birth Defects Research (Part A) 2009. © 2009 Wiley‐Liss, Inc.
Response of a concentrated monoclonal antibody formulation to high shear
Authors: Bee Jared S. , Stevenson Jennifer L. , Mehta Bhavya , Svitel Juraj , Pollastrini Joey , Platz Robert , Freund Erwin , Carpenter John F. , Randolph Theodore W.
Published: March 2009

There is concern that shear could cause protein unfolding or aggregation during commercial biopharmaceutical production. In this work we exposed two concentrated immunoglobulin‐G1 (IgG1) monoclonal antibody (mAb, at >100 mg/mL) formulations to shear rates between 20,000 and 250,000 s−1 for between 5 min and 30 ms using a parallel‐plate and capillary rheometer, respectively. The maximum shear and force exposures were far in excess of those expected during normal processing operations (20,000 s−1 and 0.06 pN, respectively). We used multiple characterization techniques to determine if there was any detectable aggregation. We found that shear alone did not cause aggregation, but that prolonged exposure to shear in the stainless steel parallel‐plate rheometer caused a very minor reversible aggregation (<0.3%). Additionally, shear did not alter aggregate populations in formulations containing 17% preformed heat‐induced aggregates of a mAb. We calculate that the forces applied to a protein by production shear exposures (<0.06 pN) are small when compared with the 140 pN force expected at the air–water interface or the 20–150 pN forces required to mechanically unfold proteins described in the atomic force microscope (AFM) literature. Therefore, we suggest that in many cases, air‐bubble entrainment, adsorption to solid surfaces (with possible shear synergy), contamination by particulates, or pump cavitation stresses could be much more important causes of aggregation than shear exposure during production. Biotechnol. Bioeng. 2009;103: 936–943. © 2009 Wiley Periodicals, Inc.
Pre‐steady state kinetics of ATP hydrolysis by Na,K‐ATPase
Authors: Manzoor Nikhat , Haque Mohammad M. , Khan Luqman A.
Published: March 2009

Fast reaction kinetics of ATP hydrolysis by Na,K‐ATPase has been investigated by following absorption pattern of pH sensitive dye in stopped flow spectrophotometer. Distinct pre‐steady state phase signal could be recorded with an initial decrease in acidity followed by increase in acidity. Average half time for H+ absorption and peak alkalinity was, respectively, 30 ms and 60 ms. Under optimal Na+ (120 mM) and K+ (30 mM) concentrations, magnitude of both H+ absorption and H+ release are found to be about 1.0 H+/ATPase molecule. H+ absorption and release decreased with decrease in Na+ concentration, H+ release was more affected. Both H+ absorption and H+ release are found to be independent of K+ concentration in the pre‐steady state phase. No H+ absorption or release was observed following mixing of either ADP, Na+ or K+ alone with ATPase. Effect of delayed mixing of Na+ or K+ on two phases of pre‐steady state cycle indicates that ATP hydrolytic cycle starts without K+ ions if optimal Na+ is present. ATP hydrolytic cycle does not start in the absence of Na+ ions. Results obtained have been interpreted in terms of an extended kinetic scheme for Na,K‐ATPase. Copyright © 2009 John Wiley & Sons, Ltd.
Heat transfer characteristics of coal‐water mixtures
Authors: Saeki Takashi , Usui Hiromoto
Published: March 2009

The heat transfer coefficient for the laminar flow of the coal‐water mixture (CWM) in a round tube was measured in a preheater which included three inner pipes of radii 5 mm and an outer pipe of radius 40 mm and a length of 1.8 m. It was found that the heat transfer coefficient for the CWM could be estimated from a Newtonian correlation within the experimental error. Furthermore, theremal conductivities of CWMs from thirteen kinds of coals have been measured. A simple and accurate method to predict the thermal conductivity of coal is proposed in this study.
Analyse des interactions fluide‐paroi dans un système ouvert a partir de la connaissance de la distribution des temps de sejour. Application aux dépôts d'aérosols par thermophorèse
Authors: Zoulalian A. , Albiol T.
Published: March 2009

Dans un système matériel ouvert dont on connaǐt la distribution des temps de séjour, il est possible, en utilisant le modèle de micromélange de Zwietering, de préciser le résultat d'une interaction physique linéaire fluide‐paroi pour la phase fluide mais aussi pour des particules transportées par le fluide.

Cette méthodologie est appliquée aux dépǒts d'aérosols par thermophorèse au sein de conduites cylindriques dont la température de paroi est constante.

L'interprétation de résultats expérimentaux obtenus en écoulement laminaire et turbulent montre que, pour des nombres de Knudsen compris entre 0.2 et 1.0, le coefficient de thermophorèse doit ětre évalué par la relation de Talbot.

Enfin, il existe probablement un régime d'écoulement intermédiaire entre l'écoulement laminaire et l'écoulement turbulent totalement établi pour lequel la masse d'aérosols déposée simultanément par thermophorèse et par turbulence devient minimale.
Experimental and mathematical studies of natural convection for solid‐salt dissolution in water
Authors: Hameed M. S. , Batta F. Y.
Published: March 2009

The phenomena of natural convection caused by a concentration gradient usually creates currents as a result of buoyancy forces. These forces are formed from the combined effect of a fluid density gradient and the body force (gravitational force). The above phenomenon was studied experimentally in a circular glass column of 0.08 m diameter and 1 m length. This column was erected vertically and filled with distilled water with a salt bag placed on top of it and partially immersed in water. The dissolution mechanism was then modelled and a finite difference method was used to solve the formulated equations by using the implicit scheme of MacCormack (Anderson et al., 1984). The experimental results and the numerical predictions are represented graphically and give compatible agreement.
Optimal design of n membrane reactors in series using michaelis‐menten kinetics
Authors: Prazeres D. M. F.
Published: March 2009

Exact analytical expressions are derived for the optimal design (minimum overall reaction volume) of N perfectly mixed membrane reactors in series carrying out an enzyme catalysed reaction with Michaelis‐Menten kinetics. These equations enable the direct calculation of the smallest total reactor volume (holding time) needed for a given overall conversion degree, as well as the individual reactor volume and conversion degrees. Results are compared with the ones obtained with a series of N CSTRs and with a plug flow reactor. The theoretical superiority of membrane reactors versus CSTRs is demonstrated.
Fractional gas hold‐up in gas inducing type of mechanically agitated contactors
Authors: Saravanan K. , Joshi J. B.
Published: March 2009

Fractional gas hold up was measured in gas inducing type of mechanically agitated contactors (GIMAC) with single and multiple impellers. Three vessels of 0.57, 1.0 and 1.5 m i.d. were used. For the multiple impeller system, six different impeller designs were employed. The impeller speed was varied in the range of 0.30 to 15.45 s−1. The ratio of impeller diameter to tank diameter (D/T), the submergence (S) of the upper impeller, the clearance of the lower impeller from the tank bottom (C1) and the impeller spacing (C3) were varied over a wide range. The design of the lower impeller was optimized in terms of diameter (D), blade width (W), blade angle (Bø), number of blades (nb) and the blade thickness (tb). An optimum design has been proposed for the multiple impeller system. Rational correlations have been proposed.
The solubility of HCFC22, CFC114 and HFC152A in n‐hexadecane
Authors: Wahlström Årsa , Vamling Lennart
Published: March 2009

The solubilities of chlorodifluoromethane (HCFC22), 1, 2‐dichlorotetrafluoroethane (CFC114) and 1,1‐difluoroethane (HFC 152a) in n‐hexadecane have been measured at temperatures between 303. 15 and 343. IS K and Henry's constants have been derived. The measurements were made with two different methods, a GLC method and an isochoric method. In general the results of the methods differ less than their combined margin of error, which is estimated to be less than 5% for the GLC method and less than 2% for the isochoric method.
Composition modulation of the fischer‐tropsch synthesis over a supported cobalt catalyst
Authors: Khodadadi A. A. , Hudgins R. R. , Silveston P. L.
Published: March 2009

Different cycling strategies are explored to see if carbon chain growth can be enhanced and methane formation suppressed. Of the strategies considered, bang‐bang cycling between H2 and CO feeds substantially increased the consumption of CO and H2, but the formation of higher hydrocarbons and olefins was reduced. The best strategy for longer chain hydrocarbons suitable for jet or diesel fuels was found to be cycling between syngas mixtures. None of the cycling strategies was able to produce C8+ or low‐molar mass olefin yields that matched yields found in steady‐state operation.
Drop volumes and terminal velocities in aqueous two phase systems
Authors: Bhavasar P. M. , Jafarabad K. R. , Pandit A. B. , Sawant S. B. , Joshi J. B.
Published: March 2009

The terminal velocities and sizes of drops in aqueous two‐phase systems formed by PEG (4000)‐sodium sulphate‐water, PEG (6000)‐sodium sulphate‐water and PEG (4000)‐dextran‐water were measured. Nozzle sizes were varied from 1.0 to 2.5 mm and the drops were formed of both light and heavy phases.

Based on video photographic analysis for drop formation, the shape of the drop during formation was found to have an important bearing on the drop volume. Therefore a generalised model was developed using the video photographic measurements. A correlation was developed for the terminal velocities of the drops in aqueous two phase systems, which covers Morton numbers from 0.00211 to 11050 and Eötvös numbers from 0.091 to 288.
Liquid spouting of pulp fibers in a conical vessel
Authors: Al‐Jabari M. , Van De Ven T. G. M. , Weber M. E.
Published: March 2009

Pulp fibers can be spouted in water in a conical vessel. The entities which are spouted are fiber flocs rather than individual fibers. Synthetic fibers, which do not flocculate, cannot be spouted. For comparison, rigid spherical particles were spouted with water in the same conical vessel. Liquid spouting of rigid particles was similar to gaseous spouting. For pulp spouting, the minimum spouting velocity is proportional to the mass of fibers in the bed and inversely proportional to the diameter of the inlet. For rigid particles, the minimum spouting velocity is proportional to the height of the bed and inversely proportional to the square of the diameter of the inlet. A model for the minimum spouting velocity was developed for pulp spouting.
Dépôt chimique CVD de silicium dopé in situ au phosphore. Partie 2: Analyse théorique et modélisation
Authors: Tounsi Adnen , Duverneuil Patrick , Couderc Jean‐Pierre , Scheid Emmanuel
Published: March 2009

La modélisation du comportement d'un réacteur de CVD permet d'une part de mieux comprendre les mécanismes complexes impliqués et d'autre part de déterminer les conditions permettant de réaliser des dépǒts conformes aux spécifications requises industriellement. Cette démarche est appliquée au cas du dépǒt de silicium polycristallin dopé in situ au phosphore. Elle a permis l'élaboration d'un modèle représentatif de l'opération de dépǒt qui prédit correctement les surépaisseurs de dépǒt dues au silylène. Le contrǒle de l'opération de dépǒt résulte principalement de la concentration en phosphine d'alimentation et de la géométrie de la zone d'entrée où se forme le silylène.
Extraction equilibrium of m‐cresol by tri‐n‐octylamine sulfate salts
Authors: Wang Maw‐Ling , Liu Biing‐Lang , Lin Ying‐I
Published: March 2009

The influence of the extraction conditions on the distribution coefficient of m‐cresol were investigated. The equilibria of m‐cresol extraction from an aqueous solution by the tri‐n‐octylamine sulfate salts (TOA salts) in an organic solvent were examined. Sulfuric acid first reacted with tri‐n‐octylamine (TOA) to form TOA salts; then m‐cresol was extracted into the organic phase from the aqueous phase by the TOA salts. The model of the equilibrium of the chemical reaction of TOA and sulfuric acid to form the TOA salts was constructed by modifying the Wilson model (Wilson, 1967). The predictions of the developed model were fairly consistent with the experimental data, and it was applied to the reaction systems in benzene at various temperatures to predict the extraction of m‐cresol. The number of water molecules associated with the various TOA salts, which reflect the extraction capability of m‐cresol, was determined.
Chlorine dioxide delignification kinetics and eop extraction of softwood kraft pulp
Authors: Tessier Patrick , Savoie Martin
Published: March 2009

A kinetic model for 100% chlorine dioxide delignification based on experimental data is presented. From the unbleached kappa number, chlorine dioxide charge and reaction time, the model predicts kappa, brightness and residuals after the first bleaching stage. The model consists of two ordinary differential equations representing the slow and fast reactions of lignin with chlorine dioxide. In addition we found that the relationship between the chlorine dioxide consumption and the kappa number decrease was linear in the range studied and independent of the unbleached pulp kappa number.
Kinetics of hydrogen peroxide bleaching of ALCELL® derived pulp
Authors: Ni Y. , Dixon C. , Ooi T.
Published: March 2009

In this study, a kinetic model of the final bleaching stage with hydrogen peroxide in a totally chlorine free (TCF) bleaching sequence for ALCELL® processed pulp was developed. The model was based on the rate of chromophore destruction characterized by the decrease in the light absorption coefficient of bleached pulp at 457 nm, CK. Based on the fact that the chromophore destruction proceeds rapidly in an initial phase followed by a much slower reaction during which a “floor‐level” chromophore concentration is approached asymptotically, we propose that the hydrogen peroxide stage of the ALCELL® derived pulp in the studied TCF sequence consists of two distinct phases. The initial phase is a very fast reaction. The rate equation of the second phase was determined as:

which is valid in a pH range of 10.5 to 11.5 and a temperature range of 60 to 92.5°C.
Optimization of an alkaline peroxide interstage treatment of jack pine (Pinus banksiana lamb.) using a D‐optimal design
Authors: Lanouette R. , Valade J. L. , Thibault J.
Published: March 2009

For many decades, the utilization of jack pine in the pulp and paper industry has attracted considerable interest but without any major breakthrough. However, in the past few years the emergence of new technologies has provided hope for its potential use. One of these technologies consists in the addition of hydrogen peroxide within the thermomechanical pulping process. To study the influence of numerous process parameters on the interstage treatment of jack pine and to optimize this complex process, a D‐optimal experimental design was conducted. A total of 7 variables were considered.

It was found that to maximize the properties of the fibres and the resulting paper, a temperature of 115°C with a narrow plate gap at the first refining stage and a high consistency at the second stage had to prevail. A sodium hydroxide treatment radically improved the fibre bonding properties without affecting the tear strength but at the expense of a loss of 4,6 points in ISO brightness. Validation trials allow to draw some conclusions on the advantages and shortcomings of this type of experimental design. This design is efficient, provided sufficient information is available to target likely interactions. Otherwise, a screening design would be required thus increasing the total cost of the study.
Optimizing refiner operation with statistical modelling
Authors: Broderick G. , Lanovette R. , Valade J. L.
Published: March 2009

A series of pilot scale refining trials has been conducted to study the impact of refining conditions on the energy efficiency of the process and on the handsheet quality of a chemimechanical pulp. Black spruce (Picea mariana) chips, cooked to a yield of 90% and a sulphonate content of 1.4%, were refined in two atmospheric stages. Plate gap and consistency in each stage was controlled according to a central composite design. Statistical models of refiner performance were constructed from these experimental results and a non‐linear optimization of process conditions was conducted. Optimization results were verified with plant trials which indicate that increasing the ratio of specific energy applied in the first stage leads to a reduction of approximately 15% in the total energy required. Inversely, this strategy can be used to obtain significant increases in pulp quality for a given energy input. The results also indicate that the largest proportion of energy must be applied to the fibres at high consistency.
Liquid—solid mass transfer at vertical screens in bubble columns
Authors: Zaki M. M. , Nirdosh I. , Sedahmed G. H.
Published: March 2009

The effect of gas sparging on the rate of mass transfer at a vertical single screen was studied by an electrochemical technique which involved measuring the limiting current of the cathodic reduction of potassium ferricyanide. Variables studied were screen characteristics, physical properties of the solution and gas superficial velocity. Screen characteristics, e. g., mesh number and wire diameter were found to have little effect on the rate of mass transfer. The data at different screens were correlated in terms of the superficial gas velocity by the equation St Sc0.5 = 0.095 (Re Fr)−0.272, where St is Stanton number, Sc is Schmidt number, Re is Reynolds number and Fr is Froude number.

Comparison of the present data with previous results obtained with different transfer geometries has shown that screens produce higher rates of mass transfer than other geometries. The importance of the present work to catalytic and electrochemical reactor design was noted.
Three‐Dimension imaging of particle clusters in dilute gas—solid suspension flow
Authors: Tsukada M. , Ito M. , Kamiya H. , Horio M.
Published: March 2009

The three dimensional flow structure of dilute gas—solid suspensions in a small‐scale circulating fluidized bed (0.200 m riser diameter) was visualized by applying the laser sheet technique. FCC particles were fluidized with sustained solid loading at gas velocities corresponding to the turbulent and the fast fluidization regimes in cases where the solid circulation was sufficient. Three typical shapes of clusters in the core section of the riser were observed. Clusters characterized by a paraboloidal shape heading downward were connected to neighboring clusters at their tail part, forming a three dimensional network structure.
Solubility study for the purification of hydrogen from high pressure hydrocracker off‐gas by an absorption‐stripping process
Authors: Peramanu Subodhsen , Pruden Barry B.
Published: March 2009

Experiments were carried out to identify a solvent which has a high solubility and selectivity for methane relative to hydrogen at 295 K and pressures from 13.88 to 20.78 MPa. Binary solubilities with pure hydrogen and methane, and ternary solubilities with 73 mol% H2 and 27 mol% CH4 were measured at 295 K and for pressures from 6.99 to 20.78 MPa in various organic solvents. This gas mixture simulates hydrocracker and hydrotreater off‐gases which are candidates for purification with an absorption‐stripper. Of the solvents tested, 2,2,4‐trimethylpentane (iso‐octane), which showed very high methane solubility and a reasonable selectivity, and methylcyclohexane, which showed a very high selectivity and a reasonable solubility, are the best solvents for methane absorption.

Correlations for hydrogen and methane as a function of pressure and solvent solubility parameter were developed with the experimental solubilities. Binary interaction parameters for Peng‐Robinson (Peng and Robinson, 1976) and Soave‐Redlich‐Kwong (Soave, 1972) equations of state were calculated with experimental solubility results. Prediction of gas solubility in a ternary system was compared with experimental and found to be satisfactory when experimental binary interaction parameters were used.
The influence of different models in obtaining multiple solutions in distillation columns
Authors: Benz Sonia J. , Scenna Nicoĺaas J.
Published: March 2009

This paper is about the sensitivity of detection of multiple solutions to the structures or parameters incorporated in the equation system that represents a distillation column. The performance of different column simulation models, generally carried out in commercial simulators, is tested to detect multiplicity. The influence of the physicochemical estimating methods and the adopted numeric strategies to solve distillation problems is considered. Important behavioral differences have been found according to the model, the calculation method and the thermodynamic properties package used. Besides, the starting point is very important in the search of the hysteresis loop.
Oxidation of hydrocarbons by hydrogen peroxide over Ti catalysts: Kinetics and mechanistic studies
Authors: Gallot Jean Émile , Kaliaguine Serge
Published: March 2009

n‐hexane conversion to hexanols and hexanones as well as the conversion of 2‐ and 3‐hexanol to 2‐ and 3‐ hexanone, by reaction with aqueous hydrogen peroxide on titanium silicalite were the objects of kinetic investigations. The choice of these reactions is justified on the basis of an analysis of literature dealing with partial oxidation reactions performed on Ti sites in silica environments. The kinetic analysis based on equations derived using the mathematical theory of linear graphs allows several conclusions on the nature of surface intermediates and on the reaction mechanism. These conclusions are discussed in terms of the partial oxidation of organic materials by hydrogen peroxide over Ti catalysts. This review paper relies mostly on work by the authors and it intends to make an integrated presentation of the kinetics of some critically significant catalytic oxidation reactions.

The content was the subject of a plenary lecture at the 5th symposium of the Romanian Catalysis Society.
On the fuzzy logic for rule based modeling and process simulation
Authors: Qian Yu , Zhang Pei‐Rong
Published: March 2009

Some chemical processes are not well understood, and not easy to analyze and simulate with conventional mathematical approaches. A rule based approach is proposed in this paper to model such process units. Conversion between fuzzy and crisp numbers at the input and output of these units is discussed in details and a slicing conversion approach is proposed. It is shown from a case study that the approach provides a way to incorporate fuzzy models into conventional process simulators.
Robust Supramolecular Network on Ag(111): Hydrogen‐Bond Enhancement through Partial Alcohol Dehydrogenation
Authors: Pawlak Remy , Clair Sylvain , Oison Vincent , Abel Mathieu , Ourdjini Oualid , Zwaneveld Nikolas A. A. , Gigmes Didier , Bertin Denis , Nony Laurent , Porte Louis
Published: March 2009

Alcohol oxidation and self‐assembly: the in situ oxidation of hydroxyl functional groups to quinone groups promotes the formation of enhanced hydrogen bonds and allows reorganization of the resulting supramolecular self‐assemblies, which evolve from a weakly bound dense phase to a strongly bound nanoporous open structure (see picture).

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Business partnerships with nonprofits: working to solve mutual problems in New Zealand
Authors: Eweje Gabriel , Palakshappa Nitha
Published: March 2009

This paper examines partnerships between business organizations and nonprofits. Collaboration is becoming increasingly essential as organizations grow in both size and influence, and public pressure intensifies for organizations to address pressing social issues and environmental concerns. Social partnerships between business and nonprofits are widely promoted as an important new strategy which will bring significant benefits to society. A key concern in business/nonprofits collaboration is how organizations might collaborate to achieve mutually beneficial objectives that also align with corporate social responsibility. This research seeks to extend our understanding of social partnerships using an unexamined contextual setting – New Zealand. Copyright © 2009 John Wiley & Sons, Ltd and ERP Environment.