bluuebunny/crossref_metadata_2025 huggingface dataset:
Are women with endometriosis more likely to experience reduced physical performance compared to women without the condition?
Authors: Silva Tatiana , Oliveira Maiara , Oliveira Edwiges , Macena Rayllanne , de Oliveira Silva Gessica Taynara , Câmara Saionara M. A. , Micussi Maria
Published: April 2024

Background

Endometriosis is a condition of the female reproductive system associated with pelvic pain. Chronic pain can affect physical performance by limiting the functional activities, thus, it is hypothesized that women with endometriosis may also present decreased functional capacity, decreased strength, and mobility. The objective of this study is to compare physical performance in women with and without endometriosis.

Methods

This is a cross-sectional study composed of 115 women equally divided into two groups: the endometriosis group (EG), composed of women with a confirmed diagnosis of the disease by magnetic resonance imaging, and the comparator group (CG), consisting of women without suspicion of the disease. Physical performance (dependent variable) was assessed using hand dynamometry, the 6-min walk test (6MWT), gait speed, and the chair stands test. CG participants performed the tests during the luteal phase of the menstrual cycle. Descriptive statistics, unpaired t-tests, and chi-square tests were used to describe and compare the groups. Multiple linear regression tested the associations adjusted for covariates (age, income, education, age at menarche, and body mass index).

Results

The EG had worse gait speed (mean difference: −0.11; 95% CI: [−0.18 to −0.04]), weaker grip strength (mean difference: −3.32; 95% CI: [−5.30 to −1.33]), shorter distance covered in the 6MWT (mean difference: −83.46; 95% CI: [−121.38 to −45.53]), and a lower number of repetitions in the chair stands test (mean difference: −8.44; 95% CI: [−10.64 to −6.25]) than the CG, even after adjusting for covariates.

Conclusion

Grip strength, lower limb strength, mobility, and functional capacity were worse in women diagnosed with endometriosis. Women with endometriosis should be encouraged to engage in physical exercise, adopt healthy lifestyle habits, and participate in rehabilitation activities to control pain, with the aim of reducing functional impairments.
Insights into soil nematode diversity and bacterial community of Thai jasmine rice rhizosphere from different paddy fields in Thailand
Authors: Nimnoi Pongrawee , Pirankham Patawee , Srimuang Kittipong , Ruanpanun Pornthip
Published: April 2024

Globally, phytonematodes cause significant crop losses. Understanding the functions played by the plant rhizosphere soil microbiome during phytonematodes infection is crucial. This study examined the distribution of phytonematodes in the paddy fields of five provinces in Thailand, as well as determining the keystone microbial taxa in response to environmental factors that could be considered in the development of efficient biocontrol tactics in agriculture. The results demonstrated that Meloidogyne graminicola and Hirschmanniella spp. were the major and dominant phytonematodes distributed across the paddy fields of Thailand. Soil parameters (total P, Cu, Mg, and Zn) were the important factors affecting the abundance of both nematodes. Illumina next-generation sequencing demonstrated that the levels of bacterial diversity among all locations were not significantly different. The Acidobacteriota, Proteobacteria, Firmicutes, Actinobacteriota, Myxococcota, Chloroflexi, Verrucomicrobiota, Bacteroidota, Gemmatimonadota, and Desulfobacterota were the most abundant bacterial phyla observed at all sites. The number of classes of the Acidobacteriae, Clostridia, Bacilli, and Bacteroidia influenced the proportions of Hirschmanniella spp., Tylenchorhynchus spp., and free-living nematodes in the sampling dirt, whereas the number of classes of the Polyangia and Actinobacteria affected the amounts of Pratylenchus spp. in both roots and soils. Soil organic matter, N, and Mn were the main factors that influenced the structure of the bacterial community. Correlations among rhizosphere microbiota, soil nematodes, and soil properties will be informative data in considering phytonematode management in a rice production system.
Different Management of Nitrogen Application Affected Growth Characteristic of Maize (Zea mays L)
Authors: K. Jyothsna , Padmaja J , Sreelatha D , Kumar R Mahender , Madhavi A
Published: April 2024

A field study was conducted during Kharif 2019-20 at Professor Jayashankar Telangana State Agricultural University (PJTSAU), Rajendranagar, Hyderabad, Telangana, India to evaluate different handheld decision support tools for precision nitrogen management in rainfed maize (Zea mays L.). The study utilized a randomized block design and was replicated three times. The eight treatments included applying nitrogen through the State-recommended dose of 200 kg ha-1 in three splits (RDN), using a leaf color chart (LCC) based on N at thresholds 3 and 4, using a soil plant analysis development (SPAD) chlorophyll meter based on N at thresholds 35 and 40, and using a Green Seeker based on N at NDVI 0.6 and 0.8 in comparison with RDN and absolute control. Based on Green Seeker NDVI at threshold 0.8, the results showed that applying nitrogen resulted in considerably greater yields for maize grain (8408 kg ha-1), stover (9923 kg ha-1), and harvest index (45.8%). with higher yield and growth parameter viz., test weight (36.3 g ), No. of grain rows  row-1 (36.7), cob length (18.9 cm), plant height (223.7 cm), leaf area (6385.75 cm2) and dry matter accumulation (18193 kg ha-1) as compared to RDN. Similarly, Green Seeker based N at NDVI 0.8 also registered higher net returns (Rs. 118961 ha-1) and B: C ratio (4.05).
Coordination of N, O-donor Appended Schiff Base Ligand N, N’-bis (3-Methoxy Salicylidenimino-1,3-diaminopropane) towards Nickel (II), Copper (II) and Zinc (II) : Synthèses, Crystal Structure
Authors: Faye Moussa , Sarr Mariama , Guèye Mbossé Ndiaye , Tamboura Farba Bouyagui , Thiam Ibrahima Elhadj , Coles Simon , Orton James , Dieng Moussa , Gaye Mohamed
Published: April 2024

New complexes prepared by the reaction of N,N’-bis(3-methoxysalicylidenimino-1,3-diaminopropane) (H2L) with Ni(II), Zn(II) and Cu(II) ions are reported in this paper. The H2L ligand is structurally characterized by elemental analysis, NMR, infrared, UV-Vis spectroscopies, conductance and magnetic room temperature measurement. The mononuclear complex of Ni(II) (C19H24N2NiO6) is characterized by single X-ray diffraction. The compound crystallizes in the orthorhombic system in the space group Pnma with the unit cell parameters a = 7.3754(5) Å, b = 21.9576(13) Å, c = 11.5546(6) Å, α = 90°, β = 90°, γ = 90° The ligand H2L acts in tetradentate fashion in its di-deprotonated form.  Two coordinated water molecules complete the coordination sphere. The environment around the Ni(II) center is best described as an octahedral geometry.
Maximizing Yield and Sustainability: A Comprehensive Approach to Integrated Pest Management in Horticulture Crops
Authors: Reddy Ankireddy Jawahar , T Chethan , Bhujel Sudarshana , R Vijay , S N Nandini , Siddiqua Ayesha , Khayum Arshad
Published: April 2024

"Maximizing Yield and Sustainability: A Comprehensive Approach to Integrated Pest Management in Horticulture Crops" offers a holistic perspective on addressing pest-related challenges in horticulture. This approach emphasizes the integration of various strategies, including cultural, biological, and chemical methods, to effectively manage pests while minimizing adverse impacts on the environment and human health. By combining pest monitoring, crop rotation, biological control agents, and judicious use of pesticides, growers can optimize yield while reducing reliance on conventional chemical interventions. This approach not only mitigates the development of pest resistance but also promotes ecosystem health and biodiversity. Moreover, by prioritizing sustainability, growers can safeguard long-term productivity and profitability while meeting the demands for safe and high-quality produce. Overall, adopting an Integrated Pest Management approach underscores the importance of balance and synergy in achieving both economic viability and environmental stewardship in horticulture crop production.
Effect of Various Nano PGR on Growth and Productivity of wheat (Triticum aestivum Var. Shriram Super 252)
Authors: Bhutia Tashi Choki , Donbiaksiam Tabitha , Jyotsna Nongmaithem , Ariina M M Shulee
Published: April 2024

Nano PGR is a multifaceted field and has vast application in all spheres of life. But in agriculture the application and utility islimited. Use of nano PGR can assist to tackle these issues to some extent. by bieng more efficient and have longer lasting nutrient release and a higher water holding capacity reducing soil erosion, It also release multiple types of nutrient simultaneously. These nano particles are having high reactivity, better catalytic surface, rapid chemical reaction, rapidly dispersible and adsorb abundant water. The present study was conducted in the agricultural experimental farm of Calcutta University, Baruipur, 24 Parganas (south), West Bengal during winter season of 2016 and 2017 to study the “effect of various nano PGR on growth and productivity of wheat (Shriram super 252)” being conducted under slightly acidic lower gangetic alluvial region of West Bengal. The experiment was laid out in a Randomized Complete Block Design with three replications. The treatments of the experiment was T1 was control ; T2 = NPK @ 100:50:50 and foliar spray of green Nano PGR @ 0.5ml L-1; T3 = NPK @ 75:30:30 and foliar spray of Yellow Nano PGR @ 0.5ml L-1; T4 = NPK @ 75:30:30 and foliar spray of Red  Nano PGR @0.5ml L-1; T5 =  NPK @ 75:30:30 and foliar spray of Green Nano PGR @ 1ml L-1; T6 = NPK @ 75:30:30 foliar spray of Yellow Nano PGR @ 1ml L-1; T7 =  NPK @ 75:30:30 and  foliar spray of red  Nano PGR @ 1ml L-1; T8 = NPK @ 75:30:30 and foliar spray of Green Nano PGR @ 1.5ml L-1; T9 = NPK @ 75:30:30 and foliar spray of Yellow Nano PGR @ 1.5ml L-1 ; T10 = NPK @ 75:30:30 and foliar spray of Red Nano PGR @ 1.5ml L-1 .The recommended dose of inorganic fertilizer was 100:50:50 and 75:30:30 of N, P2O5 and K2O kg ha-1respectively.All the yield attributing characters showed that the usage of different doses of green nano PGR through foliar application has positive effects compared to yellow and red nano PGR and the lowest was from control.
Evaluating Internet Network Quality: A Comprehensive Analysis by the PNUP Directorate of Building
Authors: Abduh Ibrahim , Syam Husain , Muis M Abdul
Published: April 2024

This study raises the problem of the condition of the building network of the Directorate of PNUP which has an irregular cabling structure so that if a network installation is carried out by connecting to the nearest switch without regard to cable paths, the cables are not on the path according to the irregular distribution of IP networks and bandwidth. The purpose of this study is to enhance the quality of the internet network in the PNUP Directorate building, compare the network performance before and after revitalizing fiber optic cables, and determine the internet bandwidth requirements in the PNUP Directorate building. The method employed is assessing internet network performance using Quality of Service parameter, by evaluating when the implementation that has been carried out is deemed sufficient, the evaluation is carried out based on the test results of the Quality of Service parameter. The user speed test is performed on public IP, followed by data recording and capture using tilnet tools. The values for delay, throughput, packet loss, and jitter are then processed and calculated. The outcome of this research demonstrates that network revitalization has successfully increased bandwidth usage, particularly in data transmission (Tx). Additional capacity and increased network performance after the revitalization allow for greater and more efficient use of bandwidth in transmitting data.
Die Streitverkündung im Arzthaftungsprozess
Authors: Grohs Kristina , Schütz Tim
Published: April 2024

Krankenhäuser und Ärzte sehen sich mit einer erhöhten justiziellen Sensibilität ihrer Patienten für ihre Behandlungsmaßnahmen konfrontiert, die oftmals mit einer gerichtlichen Überprüfung des Falles einhergeht. Aufgrund der zunehmenden Spezialisierung vieler Kliniken, aber z.B. auch im Zusammenhang mit dem demografischen Wandel und der Vielzahl altersspezifischer Krankheiten sind dabei oft unterschiedliche Behandler in die streitgegenständliche Behandlung involviert. Geklagt wird dennoch oft nur gegen einen Behandler, obwohl es möglicherweise auf unterschiedlichen Ebenen zu Versäumnissen gekommen ist. In diesen Fällen bietet die Streitverkündung auf Beklagtenseite die Möglichkeit, Folgeansprüche zu sichern. Zudem ist die Streitverkündung auch von Anwaltsseite aus nicht zu vernachlässigen, da Fehler hier haftungsrelevant sind. Vor diesem Hintergrund ist es lohnenswert, sich die Besonderheiten der Streitverkündung im Arzthaftungsprozess genauer vor Augen zu führen.
Steuerberater und Wirtschaftsprüfer: Möglichkeiten der Haftungsbegrenzung in AGB – Enthaftung bis zum Vorsatz?
Authors: Gräfe Jürgen
Published: April 2024

Haftungsfreizeichnungen sind bei Verwendern von AGB‘s gegenüber Verbrauchern und Unternehmen beliebt. Die schärfste Freizeichnung ist die für vorsätzliches und grobfahrlässiges Handeln. Allerdings ist sie gem. § 309 Nr. 7b BGB untersagt. Das Verbot gilt nach h.M. auch im Handelsverkehr. In der Praxis werden in den Allgemeinen Auftragsbedingungen von Steuerberatern und Wirtschaftsprüfern häufig Klauseln verwendet, die den Anschein erwecken, als ob diese Gesetzeslage nicht zur Kenntnis genommen werden soll. Der folgende Beitrag erläutert das Verhältnis der gesetzlichen Grundlagen für die Haftungsbegrenzung von Angehörigen der rechts- und steuerberatenden Berufe in AGB und zeigt auf, aus welchen Gründen alle nur eine einheitliche Enthaftung für leicht fahrlässiges Verschulden vereinbaren und diese mit einer dem Auftragsinhalt und den Vermögensinteressen angemessenen Höchsthaftungssumme unterlegen sollten.
Risk variants in the S100B gene predict elevated S100B serum concentrations in healthy individuals
Authors: Hohoff Christa , Ponath Gerald , Freitag Christine M. , Kästner Florian , Krakowitzky Petra , Domschke Katharina , Koelkebeck Katja , Kipp Frank , von Eiff Christof , Deckert Jürgen , Rothermundt Matthias
Published: March 2009

Several lines of evidence suggest an important role of the S100B protein and its coding gene in different neuropathological and psychiatric disorders like dementia, bipolar affective disorders and schizophrenia. To clarify whether a direct link exists between gene and gene product, that is, whether S100B variants directly modulate S100B serum concentration, 196 healthy individuals were assessed for S100B serum concentrations and genotyped for five potentially functional S100B SNPs. Functional variants of the serotonergic genes 5‐HT1A and 5‐HTT possibly modulating S100B serum levels were also studied. Further, publicly available human postmortem gene expression data were re‐analyzed to elucidate the impact of S100B, 5‐HT1A and 5‐HTT SNPs on frontal cortex S100B mRNA expression. Several S100B SNPs, particularly rs9722, and the S100B haplotype T‐G‐G‐A (including rs2186358‐rs11542311‐rs2300403‐rs9722) were associated with elevated S100B serum concentrations (Bonferroni corrected P < 0.05). Of these, rs11542311 was also associated with S100B mRNA expression directly (Bonferroni corrected P = 0.05) and within haplotype G‐A‐T‐C (rs11542311‐rs2839356‐rs9984765‐rs881827; P = 0.004), again with the G‐allele increasing S100B expression. Our results suggest an important role of S100B SNPs on S100B serum concentrations and S100B mRNA expression. It hereby links recent evidence for both, the impact of S100B gene variation on various neurological or psychiatric disorders like dementia, bipolar affective disorders and schizophrenia and the strong relation between S100B serum levels and these disorders. © 2009 Wiley‐Liss, Inc.
Aminosäuren als Katalysatoren für asymmetrische Umsetzungen in Wasser
Authors: Paradowska Joanna , Stodulski Maciej , Mlynarski Jacek
Published: March 2009

Wasser kann wild sein, wie im Ölgemalde „ES“ von Zdzislaw Beksinski (1985; 90 cm×92 cm; Wiedergabe mit Genehmigung von Piotr Dmochowski). Doch es gilt auch als ein vielversprechendes Medium für asymmetrische Reaktionen. Natürliche Aminosäuren sind hier ideale Kandidaten. Dieser Kurzaufsatz beschreibt aktuelle Fortschritte auf dem Gebiet der asymmetrischen Katalyse in Wasser unter Anwendung von Aminosäuren und ihren Derivaten.

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Asymmetrische metallorganische und organokatalytische Prozesse in wässrigen Systemen werden derzeit intensiv erforscht. War das gesamte Thema vor einigen Jahren nur wenigen Anwendern bekannt, so haben sich organische Reaktionen in Wasser inzwischen zu einem faszinierenden Forschungsgebiet entwickelt. Die Anwendung von Aminosäuren als Quelle für Chiralität – nach dem Vorbild der Natur – erscheint besonders vielversprechend für wässrige Systeme. Hier werden aktuelle Fortschritte der asymmetrischen Katalyse in Wasser mit Aminosäuren und ihren Derivaten als Katalysatoren oder wesentliche Bestandteile von Katalysatoren vorgestellt.
The genome‐centric concept: resynthesis of evolutionary theory
Authors: Heng Henry H. Q.
Published: March 2009

Modern biology has been heavily influenced by the gene‐centric concept. Paradoxically, this very concept – on which bioresearch is based – is challenged by the success of gene‐based research in terms of explaining evolutionary theory. To overcome this major roadblock, it is essential to establish new theories, to not only solve the key puzzles presented by the gene‐centric concept, but also to provide a conceptual framework that allows the field to grow. This paper discusses a number of paradoxes and illustrates how they can be addressed by the genome‐centric concept in order to further resynthesize evolutionary theory. In particular, methodological breakthroughs that analyze genome evolution are discussed. The multiple interactions among different levels of a complex system provide the key to understanding the relationship between self‐organization and natural selection. Darwinian natural selection applies to the biological level due to its unique genetic and heterogeneous features, but does not simply or directly apply to either the lower non‐living level or higher intellectual society level. At the complex bio‐system level, the genome context (the entire package of genes and their genomic physical relationship or genomic topology), not the individual genes, defines the system and serves as the principle selection platform for evolution.
A molecular thermodynamic approach to the prediction of phase equilibria in reservoir simulation
Authors: Lira‐Galeana Carlos , Ponce‐Ramirez Luis , Garcia‐Sanchez Fernando
Published: March 2009

Highly asymmetric molecules interacting during miscible‐gas processes of oil recovery are responsible for the form of the reservoir fluid phase diagrams, from which feasible displacement conditions can be chosen. In order to fit the expermental fluid phase behavior, current reservoir models employ classical equations of state which cannot easily account for the polydisperse and asymmetric nature of such systems.

Using a continuous thermodynamics extension of the Simplified Perturbed Hard‐Chain Theory (SPHCT) equation of state of Kim et al. (1986), an alternative molecular method for representing these equilibria in reservoir‐fluid systems is presented. The approach yields results which compare well with both experimental data and classical calculation procedures.
Distinctions between low density and high density circulating fluidized beds
Authors: Zhu J.‐X. , Bi H.‐T.
Published: March 2009

While many fundamental studies have been carried out in relatively low density circulating fluidized beds (LDCFB), there has been little reported fundamental study of the high density (including high solids flux and/or high solids concentration) circulating fluidized bed (HDCFB), although many commercial CFB setups are operating under high density conditions. Catalytic gas‐phase reactions tend to require higher gas velocity and higher solids flux and/or concentration than gas‐solids reactions, and therefore it is necessary to make a distinction between the two types of operations. The study of hydrodynamics and other fundamentals of HDCFB will help in understanding the fundamentals and thus improving the design and operation of existing HDCFB reactors such as FCC risers, and may also lead to other applications requiring even higher solids/gas feed ratios and/or higher solids concentration in the riser. On the other hand, high density operation can only be achieved by properly choosing the gas blower, solids feeding system and CFB geometry to avoid the instabilities resulting from insufficient pressure head from the gas blower and downcomers.
Effects of pressure and temperature on flow regimes in gas—Solid fluidization systems
Authors: Bi H. T. , Grace J. R.
Published: March 2009

The effects of operating temperature and pressure on the flow regimes of gas—solids fluidization are predicted based on the recently published flow regime diagram of Bi and Grace (1995b). The predictions are consistent with the evidence available in the literature. At constant superficial gas velocity, increasing system pressure and decreasing system temperature shift the behaviour toward higher velocity flow regimes. The opposite trends are realized if, instead, the gas mass flowrate is held constant.
The mean flow field generated by a pitched blade turbine: Changes in the circulation pattern due to impeller geometry
Authors: Mao De‐Ming , Feng Lian‐Fang , Wang Kai , Li Yu‐Ling
Published: March 2009

The mean flow field in a tank stirred with a pitched blade turbine was measured using a two‐component Laser Doppler Anemometer system (LDA). The effects of impeller clearances and impeller geometries (number of blades, blade angle and blade size) on the mean flow field have been studied. The primary pumping number, induced pumping number of the primary circulation loop and the induced pumping number of the secondary circulation loop, which often has been ignored, are reported. The flow patterns and circulation loops are more complex than those traditional ones, which vary with the geometries of the PTD and the clearances.
Measurement of the local intensities of segregation with the tomographical dual wavelength photometry
Authors: Buchmann Mathias , Mewes Dieter
Published: March 2009

The newly developed tomographical dual wavelength photometry enables the measurement of the local intensity of segregation at a multitude of points inside the stirred vessel. This is done by injecting a mixture of an inert and a reacting dye into the vessel. The inert dye serves as a tracer for the macromixing, whereas the vanishing of the reacting dye shows the micromixing. The concentration fields of the dyes are measured simultaneously by transluminating the vessel from three directions with superimposed laser beams of different wavelength. The light absorption by the dyes is measured with CCD‐cameras and these projections are used for the tomographic reconstruction of the concentration fields. Low Reynolds number measurements with a Rushton turbine show better macro‐ and micromixing for a dye injection closer to the stirrer shaft compared to a position closer to the main vortex.
Tuning digital PI controllers for minimal variance in manipulated input moves applied to imbalanced systems with delay
Authors: Kelly Jeffrey Dean
Published: March 2009

Determining the discrete‐time proportional plus integral (PI) controller tuning parameters to achieve the smallest possible variance in the manipulated input moves, for a given variance in the controlled output, is the subject of this article. Previous researchers have developed tuning rules for PI and PI permutated nonlinear controllers to achieve what is commonly referred to as “level‐flow smoothing”, or “averaging level control”, on imbalanced or integrating processes with delay, such as liquid level and gas pressure systems. The intent of this note is to demonstrate a new and simple technique of tuning digital PI controllers which utilizes either open or closed‐loop historical data to estimate the process gain, dead‐time and expected flow disturbance magnitude from which the digital PI tuning constants can be easily derived. By parameterizing the closed‐loop system as a function of the PI tuning constants, we can simultaneously minimize the expected variation in the process input move and output responses while at the same time ensuring nominal stability of the overall system. In order to demonstrate the technique, an illustrative example is included which highlights the new procedure on an oil refinery liquid surge drum level process.
Dynamic analysis of adsorption equilibrium and rate parameters of reactants and products in MTBE, ETBE and TAME production
Authors: Oktar Nuray , Mürtezaoǧlu Kirali , Doǧu Gülşen , Doǧu Timur
Published: March 2009

Adsorption equilibrium constants of ethanol, methanol, isobutylene, isoamylenes (2M2B, 2M1B), MTBE and TAME on Amberlyst 15 catalyst were evaluated from the packed bed moment technique. Adsorption equilibrium constants of alcohols were found to be two orders of magnitude greater than the adsorption equilibrium constants of i‐olefins and the corresponding tertiary ethers. However, their apparent heat of adsorption values are quite low (‐6,7 kJ/mol and −8.3 kJ/mol for methanol and ethanol, respectively). Among the i‐olefins, isobutylene gave the highest adsorption equilibrium constant and the heat of adsorption (‐54.2 kJ/mol The adsorption equilibrium constant of 2M2B on a catalyst, which was pretreated with ethanol, was about three times greater than the corresponding value obtained on fresh catalyst. Second moment analysis indicated that diffusion resistance in both macropores and microspheres of the catalyst are equally significant.
Increase of ethanol productivity in an airlift reactor with a modified draught tube
Authors: Vicente António A. , Dluhý Marián , Teixeira José A.
Published: March 2009

Static mixers were introduced in the draught tube of a three‐phase, concentric tube type airlift bioreactor, resulting in a 30% increase in ethanol productivity during glucose fermentation with a highly flocculent strain ofSaccharomyces cerevisiae.Increased productivity was obtained as a consequence of the floe size reduction provoked by the new design of the draught tube and of the smaller applied aeration rates, allowing a higher dilution rate to be used. Steady state data at different dilution rates were measured for both systems and the results were compared in terms of specific consumption / production rates and ethanol productivity. An approach based on heterogeneous catalysis principles was used in order to consider the presence of porous yeast flocs. Total glucose conversion was achieved at a dilution rate of 0.34 h−1. The smaller floe size contributed to the higher observed reaction rates by reducing diffusional limitations inside the flocs. The respiratory quotient had a constant value (around 23) at all dilution rates, meaning that the metabolic state of the cells in the flocs remained constant, having a strong fermentative metabolism.
A note on the drag coefficient of a single gas bubble in a power‐law fluid
Authors: Rodrigue Denis , De Kee Daniel , Man Fong Chen Feng Chan
Published: March 2009

The motion of a single gas bubble is examined in the case of creeping flow where the exterior phase obeys the power‐law model. An expression is developed for the drag coefficient using a perturbation method up to the second order in the parameter α = (n‐1)/2. The relation obtained is compared with existing correlations and experimental data.
Agitator design for solids suspension under gassed conditions
Authors: Lehn Mary C. , Myers Kevin J. , Barker André
Published: March 2009

Design of mechanical agitators for solids suspension under gassed conditions can be achieved using a constant ungassed torque criterion if the solids suspension task is more difficult than the gas dispersion task. When gas dispersion is the more difficult task, design for complete gas dispersion will ensure solids suspension. Evidence supporting this approach is very strong for radial‐flow impellers, but less so for up‐pumping and down‐pumping axial‐flow impellers.
Pressure gradients, voidage and gas flow in the annulus of spouted beds
Authors: He Y.‐L. , Lim C. Jim , Grace John R.
Published: March 2009

Parallel measurements of pressure gradients with a differential pressure probe and voidage profiles with a fibre optic system have been carried out to study gas flow distributions in the annulus of spouted beds. The observation of Grbavcic et al. (1976) that for a given fluid‐solid combination and column geometry the annulus pressure gradient at any bed level is independent of bed depth was corroborated again. Calibration curves of pressure drops versus superficial gas velocities for beds of voidage higher than the loose‐packed voidage were obtained by applying the Ergun (1952) equation, making it possible to estimate superficial gas velocities in the annulus using the static pressure gradient method. The local superficial gas velocity in the annulus was found to be higher in a deep bed than in a shallow bed of the same material, contrary to the conclusion (Grbavcic et al., 1976) that, for a given fluid‐solid combination and column geometry, the annulus fluid velocity at any level is independent of bed depth. Theoretical models and equations which do not account for the conical geometry near the bottom were found to underpredict superficial gas velocities in the annulus. Increasing the spouting gas flow was found to increase the net gas flow through the annulus.
Hydrodynamics in a gravity settling vessel: CFD modelling with LDA validation
Authors: Wan M. H. , Bara B. , Hackman L. , Czarnecki J. , Afacan A. , Nandakumar K. , Masliyah J. H.
Published: March 2009

Vertical gravity settling vessels, usually referred to as primary separation vessels (PSV), are used in separating bitumen aggregates from slurry containing sand and fine clays. The hydrodynamics in the PSV influences the separation efficiency of recovered bitumen through the overall mean flow and turbulent interaction. In order to deepen our understanding of the hydrodynamic conditions in such vessels, this paper presents a combined study of the flow field using Laser Doppler Anemometry (LDA) to measure the velocity field, and computational fluid dynamics (CFD) simulations to validate the CFD model. The investigation shows that the flow geometry has a significant influence on the overall flow pattern in such vessels. It also demonstrates that the CFD simulation is a reliable tool in capturing the complex mean flow pattern observed in experiments. Use of different turbulent models such as the standard k‐ε model and Reynolds stress model has very little effect on the mean flow field.
Evaluation of radial voidage profiles in packed beds of low‐aspect ratios
Authors: Mariani Nestor J. , Mazza German D. , Martinez Osvaldo M. , Barreto Guillermo F.
Published: March 2009

The relationship between the radial voidage profile, ϵ(r), and the radial distribution of centres of mono‐sized spherical particles, f(r), is revised. A close expression is given for the section S(r1, rc), the area of the segment of a cylindrical surface of radius r intersected by a particle centred at rC. From this expression, ϵ(r) can be evaluated straightforwardly from the knowledge of f(r). The range 1≥ a ≥ 2 of aspect ratios (a = dT/dp is then analysed specifically. For this range, the distribution of spherical particles has been characterized theoretically (Govindarao et al., 1992) and a simple expression allows the evaluation of ϵ(r). The use of this expression for actual catalyst particles, imperfect spheres showing a distribution of sizes, in finally analyzed.
Parametric studies of carbon dioxide absorption into highly concentrated monoethanolamine solutions
Authors: Demontigny David , Tontiwachwuthikul Paitoon , Chakma Amit
Published: March 2009

Carbon dioxide (CO2) absorption into highly concentrated solutions of monoethanolamine (MEA) was studied. The effect of operating parameters on the overall mass transfer coefficient (KGav) was determined in a pilot‐plant scale absorption unit. The (KGav) increased at low solution concentrations, decreased at intermediate concentrations, and increased as the concentration became high (54 wt%). The (KGav) increased with an increasing liquid flow rate, decreased with an increase in either the CO2 loading or the CO2 partial pressure, and was not affected by the inert gas flow rate. Finally, structured 4A Gempak packing produced (KGav) values twice as high as randomly packed IMTP#15 or 16‐mm Pall Ring systems.
Mathematical modelling and its use for design of feeding strategies for L‐Sorbose fermentation
Authors: Giridhar Raghavan Nair , Srivastava Ashok Kumar
Published: March 2009

Batch sorbitol to sorbose bioconversion by Acetobacter suboxydans using initial sorbitol concentration (S0 = 100 g/L) yielded a productivity of 10.11 g/L‐h and 98.6% conversion in 10 h time. The batch kinetics was then used to develop an unstructured mathematical model. Model parameters were identified using a nonlinear regression technique assisted by a computer program which minimized the deviation between the model predictions and actual batch experimental data. F test indicated 99% confidence on the prediction of model using optimized parameters. The batch model was eventually extrapolated to identify nutrient feeding strategies to maintain constant noninhibitory sorbitol supply and eliminate substrate limitation for fed‐batch fermentation in order to improve the sorbose productivity. The adequacy of the fed‐batch model was established by excellent agreement between experimental data and model simulation (except towards the end of fermentation).
The activity coefficients of glycine, DL‐Serine and DL‐Valine in aqueous solutions containing nitrates at 298.15 K
Authors: Gao Chongxia , Vera Juan H.
Published: March 2009

An electrochemical method was used to measure the mean activity coefficients of amino acids in water‐electrolyte‐amino acid systems. The amino acids were glycine, DL‐serine and DL‐valine and the electrolytes were KNO3 and NaNO3. The activity coefficients of the electrolytes were obtained from the e.m.f measurements in an electrochemical cell with an anion and a cation ion‐selective electrodes, each measured versus a double junction reference electrode at 298.15 K. The activity coefficients of the amino acids in the ternary systems were obtained from those of the electrolyte according to the cross differential relation. A simple semi‐empirical model based on a modification of a more complex form, derived from perturbation theory, was used to correlate the activity coefficients in binary aqueous solutions and in ternary systems.
Axial liquid dispersion in a liquid–solid circulating fluidized bed
Authors: Zheng Ying
Published: March 2009

Although axial liquid dispersion has been studied extensively in particulate fluidized beds, no data has been reported previously in a liquid–solid circulating fluidized bed (LSCFb). In this work, the axial liquid dispersions at various radial positions were measured in an LSCFB of 76 mm in diameter and 3.0 m in height using a dual conductivity probe. The results reveal that the axial liquid dispersion is affected not only by the operating conditions but by the radial positions as well. A local axial dispersion model is proposed to describe the axial liquid dispersion at various radial positions. The local axial liquid dispersion coefficients determined by the proposed model are greater at the axis than near the wall region of the riser. This nonuniformity of axial liquid dispersion is believed to be caused by the radial nonuniform distribution of liquid velocity, and bed voidage in the LSCFB can significantly affect the axial liquid dispersion.
In vitro breeding of grey poplar (Populus × canescens) for phytoremediation purposes
Authors: Bittsánszky András , Gyulai Gábor , Gullner Gábor , Kiss József , Szabó Zoltán , Kátay György , Heszky László , Kömíves Tamás
Published: March 2009

BACKGROUND: Paraquat‐tolerant poplar (Populus × canescens) clones (PQT) were selected in in vitro nodal segment cultures at the sublethal paraquat concentration (0.4 µmol L−1). After testing on tissue culture media, regenerants were micropropagated, rooted and transplanted to a greenhouse followed by a field test at heavily contaminated fields of the Chemical Company Balatonfüzfö (Hungary).

RESULTS: PQT clones showed significantly higher gst (glutathione S‐transferase) gene expression level than the wild type (WT) analyzed by qRT‐PCR (quantitative reverse transcriptase real time PCR). The expression level of gst gene in the PQT clones showed 70‐fold (without paraquat treatment), 4‐fold (at 0.1 µmol L−1 paraquat), 20‐fold (at 0.4 µmol L−1 paraquat) and 40‐fold (at 1 µmol L−1 paraquat) increments compared with WT. For functional analysis, enzyme activities of lipoxygenase (LOX; EC 1.13.11.12), glutathione S‐transferase (GST; EC 2.5.1.18), ascorbate peroxidase (APOX; EC 1.11.1.11) and glutathione reductase (GR; EC 1.6.4.2) were determined. The enzyme activity of GR and LOX, and the glutathione content (GSH) were found to be significantly higher in PQT clones.

CONCLUSIONS: Paraquat‐tolerant clones as powerful new stress tolerant and non‐GMO plants can provide an effective tool for phytoremediaton purposes where the pollutants cause oxidative stresses. Copyright © 2009 Society of Chemical Industry
Model Theory of Visco‐Elastic Properties and Relaxation Spectra of Two Different Interpenetrating Polymer Networks
Authors: Gotlib Yuli Ya. , Torchinskii Isaak A. , Toshchevikov Vladimir P. , Shevelev Vladimir A.
Published: March 2009

Dynamic viscoelastic models of the system of two different interpenetrating polymer networks with different topology and type of interactions were used for calculating spectra of relaxation times of the system under consideration. It was shown, that two branches of the relaxation spectrum appear for two models of interpenetrating networks with different components. One of the branches is the branch of the collective motion of double network consisting of two initial interacting networks. Parameters of this branch of relaxation spectrum are defined by both own elastic constants of each of interacting networks and by effective quasi‐elastic interactions between two networks. This branch is the low frequency one and is described by broad relaxation time spectrum. The second branch is the high frequency one and characterizes mutual local motions of two interacting networks. The relaxation spectrum of this branch is comparatively narrow and depends on the quasi‐elastic constants and mutual friction which is defined by the entanglements of the networks and by its effective rigidity. The second branch does not contain extremely large relaxation times for infinitely large networks.
2‐D DIGE identification of differentially expressed heterogeneous nuclear ribonucleoproteins and transcription factors during neural differentiation of human embryonic stem cells
Authors: Barthéléry Miguel , Jaishankar Amritha , Salli Ugur , Freeman Willard M. , Vrana Kent E.
Published: March 2009

Neural stem cells (NSC) are progenitors that can give rise to all neural lineages. They are found in specific niches of fetal and adult brains and grow in vitro as non‐adherent colonies, the neurospheres. These cells express the intermediate filament nestin, commonly considered an NSC marker. NSC can be derived as neurospheres from human embryonic stem cells (hESC). The mechanisms of cellular programming that hESC undergo during differentiation remain obscure. To investigate the commitment process of hESC during directed neural differentiation, we compared the nuclear proteomes of hESC and hESC‐derived neurospheres. We used 2‐D DIGE to conduct a quantitative comparison of hESC and NSC nuclear proteins and detected 1521 protein spots matched across three gels. Statistical analysis (ANOVA n = 3 with false discovery correction) revealed that only 2.1% of the densitometric signal was significantly changed. The ranges of average ratios varied from 1.2‐ to 11‐fold at a statistically significant p‐value <0.05. MS/MS identified 15 regulated proteins previously shown to be involved in chromatin remodeling, mRNA processing and gene expression regulation. Notably, three members of the heterogeneous nuclear ribonucleoprotein family (AUF‐1, and FBP‐1 and FBP‐2) register a 54, 70 and 99% increased expression, highlighting them as potential markers for NSC in vitro derivation. By contrast, Cpsf‐6 virtually disappears with differentiation with an 11‐fold drop in NSC, highlighting this protein as a novel marker for undifferentiated ESC.
Development of AlGaN/GaN HEMTs with efficiencies above 60% up to 100 V for next generation mobile communication 100 W power bars
Authors: Waltereit P. , Bronner W. , Quay R. , Dammann M. , Müller S. , Musser M. , Mikulla M. , Ambacher O. , van Rijs F. , Rödle T. , Riepe K.
Published: March 2009

We present a systematic study of epitaxial growth, processing technology, device performance and reliability of our GaN HEMTs manufactured on 3‐inch SiC substrates. Epitaxy and processing are optimized for both performance and reliability. The deposition of the AlGaN/GaN HEMT epitaxial structures is designed for both low background carrier concentration and a low trap density in order to simultaneously achieve a high buffer isolation and low DC to RF dispersion. Device fabrication is performed using standard processing techniques involving both electron‐beam and stepper lithography. The developed HEMTs demonstrate excellent high‐voltage stability, high power performance and large power added efficiencies. Devices exhibit two‐terminal gate‐drain breakdown voltages in excess of 160 V (current criterion 1 mA/mm) across the entire 3‐inch wafer with parasitic gate and drain currents well below 1 mA/mm when biased up to 80 V drain bias under pinch‐off conditions. Load‐Pull measurements at 2 GHz on 800 μm gate periphery devices return both a well‐behaved relationship between bias‐voltage and output‐power as well as power‐added‐efficiencies beyond 60% up to UDS = 100 V. For a drain bias of 100 V an output‐power‐density around 22 W/mm with 26 dB linear gain is obtained. On large periphery devices (32 mm gate width packaged in industry‐standard ceramic packages) an output power beyond 100 W is achieved with a PAE above 50% and a linear gain around 15 dB. Reliability is tested on devices having a gate periphery of 8×60 μm at an operating bias of 50 V under both DC and RF conditions. About 10% drain‐current change under DC‐stress (50 mA/mm) is observed after more than 1000 h of operation with an extrapolated drain‐current degradation below 20% after 200,000 h (more than 20 years) of operation. Under RF stress (2 GHz, 1 dB compression) the observed change in output power density is below 0.2 dB after more than 1000 h. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Design and analysis of high‐performance terahertz quantum cascade lasers
Authors: Sekine Norihiko , Hosako Iwao
Published: March 2009

We propose a new design for a high‐performance terahertz (THz) quantum cascade laser (QCL) and investigate the characteristics of the laser by using rate equation analysis. By comparing the four‐level system in our design with the three‐level system in the conventional THz QCL, it was found that both a lower threshold current and higher slope efficiency can be realized in the former. Furthermore, it was found that the four‐level system has higher operating temperature tolerance. These results are expected to contribute to the development of THz QCLs that can be operated at high temperatures. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Time‐resolved photoluminescence of type‐II InAs/GaAs quantum dots covered by a thin GaAs1–xSbx layer
Authors: Liao Yu‐An , Hsu Wei‐Ting , Lee Ming‐Chih , Chiu Pei‐Chin , Chyi Jen‐Inn , Chang Wen‐Hao
Published: March 2009

We investigate carrier lifetimes of InAs/GaAs quantum dots (QDs) covered by a thin GaAs1–xSbx layer by time‐resolved photoluminescence (PL). Both the power dependent PL peak shift and the longer decay time confirm the type‐II band alignments. Different recombination paths have been identified by temperature dependent measurements. At low temperatures, the long‐range recombination with holes trapped in the GaAsSb layer is significant, resulting in non‐single‐exponential decays. The short‐range recombination with holes confined in the band‐bending region surrounding the InAs QDs is important at higher temperatures. The variation in decay time across the ground‐state and the temporal PL peak redshift further confirm the localization of holes in the GaAsSb layer. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Firm and industry effects on firm performance: A generalization and extension for new ventures
Authors: Short Jeremy C. , McKelvie Alexander , Ketchen David J. , Chandler Gaylen N.
Published: March 2009

Our study extends a long‐running debate into the domain of entrepreneurship by examining firm and industry effects on the performance of new ventures. We examine to what extent firm and industry levels explain sales, sales growth, and survival among 7,256 young Swedish firms over a five‐year period, and compare these findings to a sample of 12,692 established firms. We found that the industry level ‘matters’ little for the survival of either sample of firms, and industry membership matters less for the sales and sales growth of new ventures than for established firms. Post hoc analysis revealed that size affects new venture performance, and that new venture funding is related to both sales and survival. At a broad level, our findings shed new light on the roles of the liabilities of newness and smallness for the performance of new ventures. Copyright © 2009 Strategic Management Society.
The Influence of Pollination on the Development of the Hop
Authors: Howard Albert
Published: March 2009

In general the hop is diœcious. Sometimes, however, in gardens of the Bramling variety, hills are met with from which bines arise bearing both male and female flowers. Such monœcious plants are rare.
The Flocculation of Turbid Liquids by Salts
Authors: Hall A. D. , Morison C. G. T.
Published: March 2009

It has long been recognised that a trace of soluble salt will bring about the flocculation of the material suspended in a turbid liquid; and because of its bearing upon such practical matters as the clearing of drinking water, the deposition of silt at the mouths of estuaries, and the improvement of the texture of heavy soils, the process has received a considerable amount of investigation. It is probably related to the flocculation of colloids by similar reagents; the fine particles of clay which chiefly cause the turbidity of natural waters being composed of a hydrated silicate of alumina and other bases possessing properties akin to those of the colloids. Indeed Schloesing has proposed to call that portion of clay material which remains obstinately suspended in water, sometimes for days together, ‘colloid clay,’ as something distinct in kind from the other particles in the soil. However it is reasonable to suppose that the distinction between the ‘colloid’ clay and the rest is in the main one of size, the colloid particles being so small as to be beyond the limits of microscopic vision, just as the trae colloids may be regarded as consisting of very large molecules, lying between the molecules which go into solution and the molecular aggregates that remain in water as suspended solids.