bluuebunny/crossref_metadata_2025 huggingface dataset:
A study of an up‐ and a down‐pumping wide‐blade hydrofoil impeller: Part II. CFD analysis
Authors: Jaworski Zdzislaw , Dyster Kate N. , Mishra Ved P. , Nienow Alvin W. , Wyszynski Miroslaw L.
Published: March 2009

Two different ways of using CFD to determine the flow field produced by the complex, wide‐blade hydrofoil APV‐B2 impeller are presented. The use of the “sliding mesh” approach was not successful and the reasons are discussed. Details of the numerical solution of the momentum transfer equations are described for the case of an axially‐symmetrical jet model. The flow field for the single impeller pumping either upwards or downwards at 200 rpm was simulated using the structured Fluent code. Good agreement of CFD predictions with LDA velocity data was found, though the maximum local energy dissipation rate was 2 1/2 to 5 times lower than was estimated from the experiments. The power numbers predicted by CFD were slightly higher than those obtained experimentally. The flow fields for dual and triple impellers pumping upwards were also simulated and used to guide larger scale homogenisation experiments.
Estimation of surface diffusion coefficient in liquid phase adsorption
Authors: Miyabe Kanji , Takeuchi Shigeya
Published: March 2009

An estimation procedure of surface diffusion coefficient, Ds, in liquid phase adsorption was proposed. The procedure is based on a restricted diffusion model, in which Ds is correlated with molecular diffusivity by considering a restriction energy due to an adsorptive interaction between adsorbates and adsorbents. In some adsorption systems, Ds of different adsorbates could be calculated with an error less than about 50% from only one datum of each adsorption equilibrium constant. Irrespective of temperature, the procedure, can be applied for the estimation of Ds even in a wide range of Ds of about 4 orders of magnitude.
Transfert de matière et chute de pression lors d'un écoulement tourbillonnaire annulaire non‐entretenu induit par une entrée tangentielle
Authors: Lefébvre Géraldine , Neto Severino R. Farias , Aouabed Hacène , Legentilhomme Patrick , Legrand Jack
Published: March 2009

Ce travail est consacré à une étude expérimentale du transfert de matière global et des chutes de pression lors d'un écoulement annulaire tourbillonnaire non‐entretenu produit par une entrée tangentielle du fluide. Les mesures de transfert de matière global, réalisées à l'aide d'une méthode électrochimique, ont montré que le transfert de masse sur le cylindre externe de la cellule annulaire est nettement plus élevé que celui relevé sur le cylindre intérieur qui demeure cependant très supérieur à celui obtenu en présence d'un écoulement axial pleinement développé dans un espace annulaire cylindrique. Ce gain, en terme de transfert de masse, s'accompagne d'une augmentation des pertes de charge, donc de l'énergie requise pour la mise en mouvement du fluide, dont la majeure partie est directement imputable à la singularité constituée par l'entrée tangentielle. Cependant, une corrélation énergétique du transfert de matière global sur les deux cylindres de l'espace annulaire montre que l'écoulement tourbillonnaire non‐entretenu généré par une conduite tangentielle permet d'accroœtre substantiellement le transfert de masse, pour une dépense énergétique égale, par rapport à une hydrodynamique axiale pleinement développée.
A mathematical model for drum drying of black liquor slurry using superheated steam impinging jets
Authors: Shiravi Amir H. , Mujumdar Arun S. , Kubes George J.
Published: March 2009

A mathematical model is developed and tested for drum drying of an aqueous slurry subjected to impinging jets of superheated steam. The heat and mass transfer within the slurry film was modeled as a one dimensional, pseudo unsteady diffusion problem while the external convective heat transfer rate was obtained by solving the steady full conservation equations of mass, momentum and energy numerically in two and three dimensions. A modified low Reynolds number version of the k‐ϵ turbulence model was selected after a careful evaluation of the predictive performance of various k‐ϵ models for impingement flow and heat transfer. The computed heat transfer one‐dimensional diffusion model for the slurry film. Agreement between experimental data obtained using a black liquor slurry and results of the model was found to be satisfactory.
Parameter sensitivity of kinetics‐based hydrometallurgical reactor models
Authors: Baldwin Susan A. , Demopoulos George P.
Published: March 2009

In this paper, we have studied the parameter sensitivity of two hydrometallurgical models: REACTSIM (for gold pressure oxidation) and ZINCSIM (for zinc pressure leaching). The parameters investigated include: the oxygen mass transfer coefficient, kLa, the activation energy for pyrite oxidation, Ea, pyrite and marmatite dissolution stoichiometry, the constant kinetic parameter for ferrous to ferric oxidation and the apparent equilibrium constant for ferric precipitation, KE. Model predictions were found to be more sensitive to the kinetic parameters under certain conditions than others. For ferrous to ferric oxidation kinetics, a dramatic model sensitivity was found to the constant kinetic parameter with an apparent discontinuity at values close to those found in bench scale experiments. The usefulness of simulation programs was demonstrated when non‐intuitive results were obtained showing ZINCSIM sensitivity to sulphate production to be opposite from what was expected. In the case of KE, solution chemistry was not as sensitive as the heat balance, which was affected significantly.
A simple adaptive control strategy for temperature trajectory tracking in batch processes
Authors: Chen Chyi‐Tsong , Peng Shih‐Tien
Published: March 2009

In this paper, a simple adaptive control strategy is suggested for temperature tracking control of batch processes. A nonlinear controller, which is in structure very simple and consists of a single parameter, is proposed. To enable this controller to control a batch process adaptively, a simple parameter tuning algorithm is derived based on the Lyapunov stability theorem. The proposed adaptive control scheme is directly operational, which does not depend on process model and the only a priori process information required is the system response direction. To demonstrate the effectiveness and applicability of the proposed scheme, illustrative examples are provided. Extensive simulation results reveal that the proposed adaptive control strategy appears to be a simple and effective approach to batch process control, which provides robust control despite the wide range of operating conditions and nonlinear dynamics of the system.
The CO‐catalyzed conversion of H2S to H2 + sulfur part 2. The thermal decomposition of COS
Authors: Faraji Farhad , Safarik Imre , Strausz Otto P. , Yildirim Erdal , Torres Manuel E.
Published: March 2009

The pyrolysis of COS has been studied over the temperature range 300 to 750°C using a variety of catalysts. The observed product distribution confirmed that two parallel reaction paths: 2 COS → 2 CO S2 (2) and 2 COS → CO2 + CS2 (4) are involved in the decomposition. The decomposition yield increased with rising temperature, accompanied with a shift in selectivity. At temperatures lower than ∼700°C the disproportionation reaction 4 was predominant, whereas at temperatures higher than 700°C, reaction 2 was favoured. In the high‐temperature region (700 to 750°C) it was possible to achieve full suppression of reaction 4 with added CS2. The pyrolysis of COS was also studied in a reactor packed with quartz chips without catalysts at high temperatures. Between 800 and 900°C, up to 99% conversion (with respect to the thermodynamic limit) could be achieved, with the almost complete absence of the disproportionation reaction 4. The results point to the commercial potential in the two‐step reaction sequence:

for the economic conversion of hydrogen sulfide to hydrogen and sulfur.
Turbulent dispersion coefficients in cyclone flow: An empirical approach
Authors: Salcedo Romualdo L. , Coelho Manuel A.
Published: March 2009

Among the various theories available to predict cyclone collection efficiency, the finite diffusivity theory of Mothes and Loffler (1988) has been shown to give the best fit of the observed grade‐efficiency curves. However, lack of knowledge on the dependence of the particles' turbulent dispersion coefficient with cyclone geometry, operating conditions and particle size has so far hindered the application of this theory for predictive purposes and for improved cyclone design. In this work, this theory is applied for predictive purposes, through the use of an empirical relation for the particles turbulent dispersion coefficient. The proposed relation is based on an analogy with turbulent dispersion in packed beds, and correlates the particle radial Peclet and Reynolds numbers. Laboratory‐scale reverse‐flow cyclones of previously unpublished geometries were built to test the applicability of the proposed relation. The Mothes and Loffler (1988) theory, when coupled with the proposed estimates of turbulent dispersion coefficients, is a powerful tool for predicting cyclone collection efficiency, short of using computational fluid dynamics tools.
Stability of gas‐inducing type impellers
Authors: Patil Swapnil S. , Josh Jyeshtharaj B.
Published: March 2009

The aim of this study is to understand the reasons for instability in the operation of a gas inducing impeller and to suggest the ways to eliminate the instability. Experiments were performed in a 1 m diameter vessel. The impeller clearance from the tank bottom was 0.52 m. The effects of impeller diameter, impeller blade width, blade thickness, impeller blade angle, shape of the impeller blade, impeller position with respect to the stator, impeller submergence and stator geometry on the instability were investigated. Phenomenological description has been provided for the occurrence of instability. An optimum design of a stator–impeller combination has been proposed for gas dispersion and stable operation.
Model‐based scale‐up strategy for mycelial fermentation processes
Authors: Yang He , Allen D. Grant
Published: March 2009

With the aid of a mathematical model describing the interrelationships between mycelial morphology, mycelial growth and product formation, rheology, mass transfer, and environmental conditions, a new scale‐up strategy has been developed, simulating the bioreactor performance at different agitation speeds. The simulations have shown that there is an optimum agitation speed, yielding maximum product formation that is different from the conventional scale‐up results based on constant Pg/VT, kL a and NI DI. It has also been shown in the simulations that the product formation scaled up by means of conventional methods is considerably lower than the simulated maximum or is close to the maximum but requiring a higher energy consumption. This indicates that model‐based scale‐up could be a more accurate and efficient method for scaling up complex systems such as mycelial fermentation processes.
Cell synchrony and periodic behaviour in yeast populations
Authors: Sheppard John D. , Dawson Peter S. S.
Published: March 2009

The underlying basis for the behaviour of a population of cells is the cell growth and division cycles of the individual cells. Under certain special circumstances, oscillations in cell cultures can be observed that are a reflection of metabolic oscillations, such as in glycolysis, or cell cycle oscillations from a partially synchronized population. These oscillations can sometimes occur spontaneously, as in the chemostat culture of Saccharomyces cerevisiae at low dilution rates, or can be induced using chemical blockers or entrainment by a periodic nutrient environment. Continuous methods for inducing a synchronized culture include the pulsed chemostat, continuous phasing and self‐cycling fermentation. Results obtained by studying both spontaneously oscillating cultures and synchronized cultures have provided insight into the mechanisms responsible for the progress and control of the cell cycle as well as the intimate relationship that exists between the cellular dynamics and the dynamics of the environment.
Surfactant effects on gas absorption in a coke‐oven gas treatment process
Authors: Shen Jui‐Fu , Yang Yu‐Min , Maa Jer‐Ru
Published: March 2009

The effect of organic impurities in industrial stripped coal water (SCW) on the absorption of CO2 was measured experimentally. Removal of these impurities via activated carbon showed a marked improvement in interphase mass transfer of a vertical wetted‐wall column absorber. However, this benefit was not found in a stirred‐cell absorber, in which a different flow pattern from that in wetted‐wall column absorber is expected. An ad hoc systematic study on the effects of three deliberately added surfactants on gas absorption by pure water in three different absorbers with different flow patterns was thereafter conducted. The experimental results reveal that absorption deterioration also prevails only in a vertical, wetted‐wall column absorber and the reduction in liquid phase mass transfer by the addition of surfactant can be satisfactorily correlated with surface pressure of solutions. This indicates that the effect of the industrial impurities in SCW on gas absorption may successfully be simulated under the same flow pattern by a surfactant solution with the same surface pressure. A possible modification of the existing coke‐oven gas (COG) treatment process for the benefit of absorption enhancement was finally proposed.
Model‐based multivariable control of the drying of a thin sheet of fibres in a continuous infrared dryer
Authors: Dhib Rhamdane , Thérien Normand , Broadbent Arthur D.
Published: March 2009

We developed an Internal Model Control (IMC) algorithm for drying a thin textile fabric, continuously passing through an electric infrared dryer, based on a reduced linear model of the drying dynamics. This model relates the controlled variables, the humidity and temperature of the web at the dryer outlet, to the manipulated variables, the electrical power supplied to the sources and the web speed through the dryer, and also to changes in the initial humidity of the web at the dryer inlet. The control algorithm was first tested by simulation using the model in regulation mode, and in set‐point tracking mode, to vary the manipulated variables so as to maintain the controlled variables at their respective set‐points when the inlet web temperature and humidity were changed. The performance under simulated operational conditions was compared to that of a conventional feedback proportional‐integral (PI) controller coupled with a feedforward control. The IMC controller was then tested directly in regulation mode using a pilot scale infrared dryer, acting simultaneously on the manipulated variables, the emitter power and the web speed, to control the fabric temperature and humidity at the dryer outlet. The experimental results were compared with those from the above feedback‐feedforward controller, on the pilot scale dryer. The results have indicated that the closed‐loop stability of the process is assured simply by choosing a stable IMC controller. Also, such a controller does not require the design of specific compensators for the strong interactions between variables of the drying process.
Effet d'un agitateur mécanique sur l'hydrodynamique et le transfert de matière gaz—liquide en réacteur gazosiphon
Authors: Bang Woong , Duquenne Anne‐Marie , Delmas Henri , Bascoul Aimé
Published: March 2009

Cette étude expérimentale décrit l'effet d'un agitateur sur l'hydrodynamique et le transfert de matière à l'intérieur d'un contacteur airlift à boucle interne. La contribution des deux éléments moteurs (gaz et agitateur) est identifiée. Suivant les conditions de fonctionnement, ou bien ces deux effets s'ajoutent et favorisent la circulation du liquide ou bien ces effets sont opposés, la vitesse du liquide est alors réduite. Par contre, en ce qui concerne le transfert gaz—liquide, l'utilisation de l'agitateur est bénéfique puisque, pour certaines conditions opératoires, le coefficient de transfert est multiplié par 4 par rapport à celui obtenu sans agitation. L'analyse des diverses contributions énergétiques dans l'appareil montre que la présence de l'agitateur est justifiée uniquement dans les cas où le débit de gaz doit rester faible.
A Comparison of Echocardiographic Findings in Young Adults With Cardiomyopathy: With and Without a History of Methamphetamine Abuse
Authors: Ito Hiroki , Yeo Khung‐Keong , Wijetunga Mevan , Seto Todd B. , Tay Kevin , Schatz Irwin J.
Published: March 2009

Background

Methamphetamine is currently the most widespread illegal stimulant abused in the United States. No previous reports comparing echocardiographic findings of cardiomyopathy with and without a history of methamphetamine abuse are available.

Methods

We performed a single institution retrospective review of medical records and analyses of echocardiographic findings in patients ≤ 45 years of age hospitalized between 2001 and 2004 who were discharged with a diagnosis of cardiomyopathy or heart failure. After exclusion of patients with coronary artery disease or severe cardiac valvular disease, the remaining patients were divided into 2 groups based on their abuse or non abuse of methamphetamine, as determined by the documented history in the medical records or urine toxicology testing.

Results

Among a total of 59 patients, 28 (47%) had a history of methamphetamine abuse or positive urine toxicology. Both methamphetamine abusers and non‐abusers were predominately male (64.3% vs 64.5%, P = .99), and had a high prevalence of obesity (55.6% vs 73.3%, P = .16). Bivariate analysis revealed significant differences between the methamphetamine abusers and non‐abusers in left atrium volume (119.7 ± 55.4 ml vs 85.8 ± 33.5 ml, P = .008), left ventricular end‐diastolic volume (201.9 ± 71.4 ml vs 156.6 ± 63.1 ml, P = .01), left ventricular end‐systolic volume (136.0 ± 53.7 ml vs 92.3 ± 55.8 ml, P = .004), right ventricular dimension (26.3 ± 6.0 mm vs 21.3 ± 6.0 mm, P = .007), and quantified left ventricular ejection fraction (32.9% ± 11.3% vs 44.6% ± 17.8%, P = .004).

Conclusions

We found a high prevalence of methamphetamine abuse in our study population. Methamphetamine abusers had echocardiographic findings of more severe dilated cardiomyopathy compared with non‐abusers. Copyright © 2009 Wiley Periodicals, Inc.
A novel mechanism of sperm motility in a viscous environment: Corkscrew‐shaped spermatozoa cruise by spinning
Authors: Muto Kohei , Kubota Hiroshi Y.
Published: March 2009

Fertilization of the green tree frog, Rhacophorus arboreus, occurs in the viscous environment of a foam nest, which is laid on vegetation. Their spermatozoa have a characteristic corkscrew‐shaped head and a thick tail that extends perpendicularly to its longitudinal axis. However, it is unclear how these corkscrew‐shaped spermatozoa move in this highly viscous environment. Here, we found that the spinning of the corkscrew‐shaped head, caused by winding and unwinding of the tail, enables the spermatozoa to move through the highly viscous environment of a foam nest, like a corkscrew rotating into a cork. We suggested that dislocations observed in the matrix of satellite microtubules surrounding two axonemes, reflected the planes of sliding of the axonemes, and dyneins on doublets two and six of each axoneme were active during winding and unwinding, respectively. These results provide a novel mechanism for sperm movement that is adapted specifically to a viscous fertilization environment. Cell Motil. Cytoskeleton 2009. © 2009 Wiley‐Liss, Inc.
Noble Reactions for the Actinides: Safe Gold‐Based Access to Organouranium and Azido Complexes (Eur. J. Inorg. Chem. 11/2009)
Authors: Thomson Robert K. , Graves Christopher R. , Scott Brian L. , Kiplinger Jaqueline L.
Published: March 2009

The cover picture shows a novel and safe gold‐based oxidative functionalization protocol that allows access to an assortment of uranium complexes bearing azide and carbon functional groups. Alkyl, alkynyl, and azide complexes are accessed in a single step from commercially available or easily prepared gold complexes. This methodology works for UIII → UIV and UIV → UV oxidations. A new, high‐yielding synthetic preparation of (Ph3P)AuN3 is also presented. These reactions proceed rapidly in high yields and represent a new class of reactions for gold. This work demonstrates that gold chemistry is not just unique for organic transformations but holds great promise for similarly advancing organometallic chemistry. Details are discussed in the Short Communication by J. L. Kiplinger et al. on p. 1451 ff. We thank Mr. Jim Cruz for designing the cover picture.
Altered functional properties of satellite glial cells in compressed spinal ganglia
Authors: Zhang Haijun , Mei Xiaofeng , Zhang Pu , Ma Chao , White Fletcher A. , Donnelly David F. , Lamotte Robert H.
Published: March 2009

The cell bodies of sensory neurons in the dorsal root ganglion (DRG) are enveloped by satellite glial cells (SGCs). In an animal model of intervertebral foraminal stenosis and low‐back pain, a chronic compression of the DRG (CCD) increases the excitability of neuronal cell bodies in the compressed ganglion. The morphological and electrophysiological properties of SGCs were investigated in both CCD and uninjured, control lumbar DRGs. SGCs responded within 12 h of the onset of CCD as indicated by an increased expression of glial fibrillary acidic protein (GFAP) in the compressed DRG but to lesser extent in neighboring or contralateral DRGs. Within 1 week, coupling through gap junctions between SGCs was significantly enhanced in the compressed ganglion. Under whole‐cell patch clamp recordings, inward and outward potassium currents, but not sodium currents, were detected in individual SGCs. SGCs enveloping differently sized neurons had similar electrophysiological properties. SGCs in the compressed vs. control DRG exhibited significantly reduced inwardly rectifying potassium currents (Kir), increased input resistances and positively shifted resting membrane potentials. The reduction in Kir was greater for nociceptive medium‐sized neurons compared to non‐nociceptive neurons. Kir currents of SGCs around spontaneously active neurons were significantly reduced 1 day after compression but recovered by 7 days. These data demonstrate rapid alterations in glial membrane currents and GFAP expression in close temporal association with the development of neuronal hyperexcitability in the CCD model of neuropathic pain. However, these alterations are not fully sustained and suggest other mechanisms for the maintenance of the hyperexcitable state. © 2009 Wiley‐Liss, Inc.
Dopamine neuron precursors within the developing human mesencephalon show radial glial characteristics
Authors: Hebsgaard Josephine B. , Nelander Jenny , Sabelström Hanna , Jönsson Marie E. , Stott Simon , Parmar Malin
Published: March 2009

Specification and differentiation of neural precursors into dopaminergic neurons within the ventral mesencephalon has been subject to much attention due to the implication of dopaminergic neurons in Parkinson's disease and the perspective of generating sources of therapeutically active cells to be used for cell replacement therapy for the disease. However, despite intensive research efforts, little is known about the characteristics of the dopamine neuron progenitors in human. We show that the dopamine neuron determinant LMX1a is expressed in the diencephalic and mesencephalic dopaminergic neuron domains during human development. Within the mesencephalon, LMX1a is expressed in the dopaminergic neurons and their progenitors located in the ventricular zone of the floor plate region. Furthermore, the neural progenitors in the developing human ventral mesencephalon have a radial morphology and express the radial glial markers Vimentin and BLBP. These radial glia are mitotic and act as precursors for the dopaminergic neurons. Finally, we show that progenitors isolated from the human ventral mesencephalon maintain their radial glial characteristics and neurogenic capacity after expansion in vitro, making them a promising future source of cells to be used in cell replacement therapy for Parkinson's disease. © 2009 Wiley‐Liss, Inc.
20 GHz gated tunnel diode based UWB pulse generator
Authors: Egard Mikael , Ärlelid Mats , Lind Erik , Astromskas Gvidas , Wernersson Lars‐Erik
Published: March 2009

We demonstrate a pulse generator based on a GaAs‐AlGaAs gated resonant tunneling diode (RTD). This is realized by integrating a third terminal, the gate, into the current path of a RTD. The gate consists of a 200 Å thick tungsten grating buried 300 Å above the RTD. This implementation allows for control of the current through the RTD. By integrating this device in parallel with an on‐chip inductance, a negative differential resistance (NDR) oscillator is formed. It is demonstrated that by using the gate to change the output conductance of the device, the oscillations may be switched on and off, creating short bursts of RF power. This technique allows for rapid quenching of the oscillator, and hence the ability to generate short pulses at high frequency, enabling impulse radio ultra‐wideband communication implementations. The highest demonstrated oscillation frequency is 22 GHz with an output power of –4.1 dBm, and the shortest pulses generated are 1.3 ns. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Deterministic self‐organization: Ordered positioning of InAs quantum dots by self‐organized anisotropic strain engineering on patterned GaAs (311)B
Authors: Selçuk E. , Hamhuis G. J. , Nötzel R.
Published: March 2009

Laterally ordered InGaAs quantum dot (QD) arrays, InAs QD molecules, and single InAs QDs in a spot‐like periodic arrangement are created by self‐organized anisotropic strain engineering of InGaAs/GaAs superlattice (SL) templates on planar GaAs (311)B substrates in molecular beam epitaxy. On shallow‐ and deep‐patterned substrates the respectively generated steps and facets guide the self‐organization process during SL template formation to create more complex ordering such as periodic stripes, depending on pattern design. Here we demonstrate for patterns such as shallow‐ and deepetched round holes and deep‐etched zigzag mesas that the self‐organized periodic arrangement of QD molecules and single QDs is spatially locked to the pattern sidewalls and corners. This extends the concept of guided self‐organization to deterministic self‐organization. Absolute position control of the QDs is achieved without one‐to‐one pattern definition. This guarantees the excellent arrangement control of the ordered QD molecules and single QDs with strong photoluminescence emission up to room temperature, which is required for future quantum functional devices. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Multiscale modeling and simulation of silicon carbide oxidation
Authors: Chatterjee A. N. , Matocha K. S.
Published: March 2009

The objective of this theoretical work is to understand the process of thermal oxidation of SiC and investigate the phenomenon of transition layer generation at the SiC/SiO2 interface. We have identified the reaction process to be the rate‐limiting step of SiC oxidation. The dependence of transition layer on temperature and SiC crystal plane orientation has been studied. The difference in the oxidation rates of Si face and C face of SiC has been explained using the proposed multiscale approach. The computed concentration of carbon cluster at the interface indicates the presence of interface traps due to incomplete oxidation of SiC. The mathematical models and simulation results have been validated with experimental correlations. The proposed model is valid within typical temperature conditions of dry oxidation. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Perturbing GaN/AlN quantum dots with uniaxial stressors
Authors: Moshe Ofer , Rich Daniel H. , Damilano Benjamin , Massies Jean
Published: March 2009

We have studied the effect of uniaxial stress on the optical polarization properties of GaN/AlN quantum dots (QDs) grown on Si(111) substrates. Microcracks form as a result of the thermal expansion coefficient mismatch between the GaN/AlN layers and the Si(111) substrate. We show that such microcracks serve as excellent stressors through which the strain tensor of the GaN/AlN QDs can be modified for studies of strain‐induced changes in the optical properties using a spatially and temporally resolved probe, such as with cathodoluminescence (CL) imaging and spectroscopy. CL measurements of the ground‐state excitonic transition of vertically stacked GaN/AlN quantum dots (QDs) exhibit an in‐plane linear polarization anisotropy in close proximity to microcracks, consistent with the presence of uniaxial stress. The spatial dependence of the polarization anisotropy and CL decay time in varying proximity to the microcracks are studied as a function of temperature in order to assess the influence of thermal stress variations on the oscillator strength between electrons and holes. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Quantum‐corrected Monte Carlo study of quasi‐ballistic transport in nano‐scale InGaAs HEMTs
Authors: Yamada Ryohei , Takegishi Takayuki , Hirata Yuko , Matsumoto Takayuki , Hara Shinsuke , Fujishiro Hiroki I.
Published: March 2009

The electron transport phenomena in InGaAs HEMTs at low Vgs condition are shown to be similar to Si MOSFETs. At the potential bottleneck under the gate, the momentum distribution function of the electron, f (x, kx), becomes an asymmetric shape with a small tail spread in negative direction. As Lg decreases, the negative tail of f (x, kx) becomes less significant, which is responsible for the increase of the electron velocity at the bottleneck, vs. We demonstrate that the electron scatterings collapse the hemispherical shape of f (x, kx) at the bottleneck. As Lg decreases, vs approaches the ballistic value. The ballisticity is estimated on the basis of the quasi‐ballistic transport theory. The backscattering coefficient, R, decreases and the index of the ballisticity, rB, increases as Lg decreases. At Lg = 10 nm, R and rB are estimated to be about 0.05 and 0.97, respectively, which indicates that at Lg = 10 nm, vs is almost reaching the ballistic limit. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The influence of captive adolescent male chimpanzees on wounding: management and welfare implications
Authors: Ross S. R. , Bloomsmith M. A. , Bettinger T. L. , Wagner K. E.
Published: March 2009

Adolescence, the period lasting from the onset of puberty to the emergence of physical and sexual maturity, is a period of social change for many species including chimpanzees. Several reports have implicitly linked the physiological changes that occur during male chimpanzee adolescence to significant disruption in the social group, which in turn may result in serious agonism and wounding. To assess the association between adolescent males and wounding rates, 38 institutions housing 399 chimpanzees among 59 social groups, recorded all wounds incurred by chimpanzees over a 6‐month period. The rate of wounding did not differ between groups with or without adolescent males. Adolescent males received the most wounds, but were no more likely to cause wounds than group members of any other sex–age class. Social groups with multiple adult males experienced lower wounding rates than those with a single adult male. Results indicate that (1) adolescent male chimpanzees may receive, but not inflict, more wounds than chimpanzees in other sex–age classes; and (2) management strategies that support natural social groupings may control and limit group agonism. Zoo Biol 28:623–634, 2009. © 2009 Wiley‐Liss, Inc.
Direct medical mental health care costs of schizophrenia in France, Germany and the United Kingdom – Findings from the European Schizophrenia Cohort (EuroSC)
Authors: Heider Dirk , Bernert Sebastian , König Hans-Helmut , Matschinger Herbert , Hogh Theresa , Brugha Traolach S. , Bebbington Paul E. , Azorin Michel , Angermeyer Matthias C. , Toumi Mondher
Published: March 2009

Objectives

To quantify and compare the resource consumption and direct costs of medical mental health care of patients suffering from schizophrenia in France, Germany and the United Kingdom.

Methods

In the European Cohort Study of Schizophrenia, a naturalistic two-year follow-up study, patients were recruited in France (N = 288), Germany (N = 618), and the United Kingdom (N = 302). Data about the use of services and medication were collected. Unit cost data were obtained and transformed into United States Dollar Purchasing Power Parities (USD-PPP). Mean service use and costs were estimated using between-effects regression models.

Results

In the French/German/UK sample estimated means for a six-month period were respectively 5.7, 7.5 and 6.4 inpatient days, and 11.0, 1.3, and 0.7 day-clinic days. After controlling for age, sex, number of former hospitalizations and psychopathology (CGI score), mean costs were 3700/2815/3352 USD-PPP.

Conclusions

Service use and estimated costs varied considerably between countries. The greatest differences were related to day-clinic use. The use of services was not consistently higher in one country than in the others. Estimated costs did not necessarily reflect the quantity of service use, since unit costs for individual types of service varied considerably between countries.
High throughput sequencing of microRNAs in chicken somites
Authors: Rathjen Tina , Pais Helio , Sweetman Dylan , Moulton Vincent , Munsterberg Andrea , Dalmay Tamas
Published: March 2009

High throughput Solexa sequencing technology was applied to identify microRNAs in somites of developing chicken embryos. We obtained 651 273 reads, from which 340 415 were mapped to the chicken genome representing 1701 distinct sequences. Eighty‐five of these were known microRNAs and 42 novel miRNA candidates were identified. Accumulation of 18 of 42 sequences was confirmed by Northern blot analysis. Ten of the 18 sequences are new variants of known miRNAs and eight short RNAs are novel miRNAs. Six of these eight have not been reported by other deep sequencing projects. One of the six new miRNAs is highly enriched in somite tissue suggesting that deep sequencing of other specific tissues has the potential to identify novel tissue specific miRNAs.
The Analysis of the Soil by means of the Plant
Authors: Hall A. D.
Published: March 2009

One of the main problems placed before the agricultural chemist is the estimation of the requirements of a given soil for specific manures, or the interpretation, by means of data obtained in the laboratory, of the behaviour of the soil towards these manures, as seen in properly arranged field experiments. For various reasons the obvious method of determining the proportions of Nitrogen, Phosphoric Acid, and Potash in the soil fails in many cases to give the required information; even the more modern methods of measuring only the quantities of these materials which are attacked by weak acid solvents, and in consequence regarded as available to the plant, by no means always accord with the results of experience. Hence from time to time attempts have been made to attack the problem from another side and to use the living plant as an analytical agent. The scheme is to take a particular plant grown upon the soil in question, and determine in its ash the proportions of constituents like phosphoric acid and potash. Any deviations from the normal in these proportions may then be taken as indicating deficiency or excess of the same constituent in the soil and therefore the need or otherwise of specific manuring in that direction. The theory rests on two assumptions, first that each plant has a typical ash composition, constant when the plant is grown under similar conditions; secondly that the variations in the proportion of such a constituent as phosphoric acid will reflect the amount of that plant food available in the soil, as measured by the response of the crop to phosphatic manuring. From this point of view a number of investigations have already been made: Hellriegel discussed the relative variations of the proportion of potash in the ash of barley straw and of the soil in which it was grown; Heinrich analysed the roots of oats and fixed certain minima, below which the need for specific manuring was indicated.
Soil Analysis as a guide to the Manurial Treatment of Poor Pastures
Authors: Wood T. B. , Berry R. A.
Published: March 2009

Summarising the above comparisons between soil analyses and results of manuring, the following conclusions are arrived at:

That except in extreme cases the determination of the percentages of “total” nitrogen, phosphoric acid, potash, and lime, in a soil does not give reliable indications as to the possibility of improving the pasture by manuring.

That determination of the percentage of phosphoric acid soluble in 1 per cent, citric acid solution does generally give reliable indications as to the probable success of phosphatic manuring, provided that for pasture soils the limit below which “available“ phosphoric acid may be considered as deficient is fixed as high as 0·02 per cent.

That potash manuring is suggested as likely to give distinct results if the soil contains not more than 0·01 per cent, of potash soluble in 1 per cent, citric acid solution.

That liming is not indicated as likely to be profitable unless the soil contains certainly less than 0·25 per cent, of chalk.
Note on the Fate of Calcium Cyanamide in the Soil.
Authors: Ashby S. F.
Published: March 2009

The experiments described below have been carried out to confirm some results obtained by F. Löhnis, who made it appear highly probable that soil bacteria were concerned in rendering calcium cyanamide assimilable for crops. It had been supposed that the reaction of calcium cyanamide in the soil was a purely chemical one. The material used was taken from a supply of “Kalkstickstoff” received at the Rothamsted Experimental Station from the “Cyanid Gesellschaft” of Berlin early this year. Nitrogen determinations by the Kjeldahl method showed the crude fertiliser to contain 20.3 per cent, nitrogen, equal to 58 per cent, pure calcium cyanamide.
Note on the Absorption of Atmospheric Moisture by certain Nitrogenous Manures
Authors: Brownlee George
Published: March 2009

Ten grams each of the manures Sulphate of Ammonia, Nitrate of Soda, Calcium Cyanamide and Nitrate of Lime (Notodden, 1906) were exposed to air in a room the windows of which were kept open during the experiment, and the changes in weight noted for a period of twenty-nine days. At the same time Barometric and Temperature (Wet and Dry Bulb) readings were taken daily.
Some Bacteriological Relations in Soils kept under Green-house conditions
Authors: Lipman Jacob G. , Owen Irving L.
Published: March 2009

Soils in the green-house are exposed to conditions that are admittedly more or less artificial. The range of temperature and moisture is not the same as that in field soils, while the aeration of green-house soils is, if anything, even more artificial. The artificial conditions are emphasized still more strongly when the soil is kept in small pots. The operations incident to the filling of the pots and the applications of fertilizers involve a more intimate contact of the soil particles with atmospheric oxygen than is possible under field or garden conditions. This leads to an abnormal multiplication of the soil bacteria and to a consequent abnormally rapid oxidation of the organic matter. In the course of time the more readily decomposable portions of the organic matter in the soil become depleted and this is followed, in turn, by a decline in the numbers of bacteria that will grow on agar plates. It is possible that the rapid falling off in numbers is due not merely to the depletion of the readily decomposable organic matter, but also to the accumulation of certain cleavage products injurious to the bacteria. Of the latter factor we have no direct knowledge and it is referred to in this place only as a possible explanation of the facts recorded below. It may be added here, also, that the greatly decreased number of bacteria appearing on agar plates should not be accepted as absolute proof that the total number of microorganisms in the soil had diminished. There is a possibility that a compensating increase had occurred of bacteria that do not grow on agar plates, as for instance, the nitrous and nitric ferments, etc.….
Note on the Composition of Gas Lime
Authors: Bhatt P. J.
Published: March 2009

Very few analyses of gas lime have been published; consequently the following analyses made in the laboratory of the Department of Agriculture of the University of Cambridge may be of interest to readers of this Journal.

The samples of gas lime were obtained from the Cambridge Gas Works. One was what is known as carbonated lime, that is to say, lime which had been used for purifying the gas after it had previously been purified by hydrated ferric oxide. This sample, as shown by the analysis, is practically moist calcium carbonate. It was obtained in a perfectly fresh condition. The second sample was described by the Works Manager as “sulphided lime.” It had been used for purifying gas without the previous use of ferric hydrate. A sample was taken from the centre of a large heap which had been standing for about a year.
Estimation of Calcium Carbonate in Soils
Authors: Marr F. S.
Published: March 2009

Boiling acid at atmospheric pressure decomposes organic matter in soil with evolution of carbon dioxide, and thus renders the results obtained for carbonate too high. Where there is a fairly large percentage of carbonate, the error introduced in this way is of no great importance, but in soils containing less than 1% of calcium carbonate and especially in acid soils, the error introduced by thus boiling with acid may be very considerable.

The weaker the acid used the better so long as there is fair excess. The writer recommends for acid soils and those containing low percentages of carbonate (as can be seen by making a rough preliminary test), 2 c.c. of strong hydrochloric acid and about 100 c.c. of water: 20 grams of soil should be used when the amount of carbonate is small. The acid may be conveniently added by making up a solution containing 100 c.c. of strong hydrochloric acid per litre, and introducing 20 c.c. of this solution along with 80 c.c. of water. For most soils, 5 c.c. of strong hydrochloric acid to 100 c.c. of water will be found convenient.

If possible distillation under reduced pressure should be used, as under this condition practically no decomposition of organic matter takes place, while carbonate is readily decomposed: the distillation should be continued for twenty minutes at a temperature of about 50° C.
Soils of Cambridgeshire
Authors: Foreman F. W.
Published: March 2009

In 1904, Sir James Blyth, Bart., a member of the Cambridge University Board of Agricultural Studies, offered a Scholarship tenable by a student who had taken the University Diploma in Agriculture, for the purpose of enabling him to spend a year in research. The offer was gratefully accepted, and the Scholarship was awarded to Mr F. W. Foreman. Mr Foreman submitted as a subject for investigation the Composition of certain of the Soils of Cambridgeshire. This subject was approved, and the work was carried out in the winter months of 1904—1905. The results are given in the following pages.
The Amounts of Nitrogen as Ammonia and Nitric (and Nitrous) Acid in the Rain-water Collected at Uithuizermeeden, Groningen
Authors: Hudig J.
Published: March 2009

For several years observations have been made on the composition of rain-water, collected by Mr H. Welt, at Uithuizermeeden, a village in the northern part of the Province of Groningen. These observations were made as a part of a research on nitrification in a light clay-soil, by the method of drainage-plots such as are well known from the Rothamsted investigations. The results of these researches appeared in a Dutch journal. In the meantime it seems desirable to publish the results relating to the composition of rain-water.
On Ovariotomy in Sows; with Observations on the Mammary Glands and Internal Genital Organs
Authors: Mackenzie K. J. J. , Marshall F. H. A.
Published: March 2009

Black pigment is very frequently, but not invariably present in the mammary tissue of Large-Black, Berkshire and other dark-coloured sows. It is stated that the presence of this pigment (apart altogether from the question of the pigs being “on heat”) renders the bacon less saleable, owing to its discoloured or “seedy” appearance. If this is the case, it ought to be possible to remedy this fault, by breeding from individuals in which this pigment is absent, and so building up a strain of increased commercial value.

If on the other hand it be the case that the presence of black pigment is not in itself objectionable, but that the changes in the mammary area due to the occurrence of heat are what are not desired, the remedy is to be sought in spaying, a practice which must be carried out on a sufficient scale and be efficiently performed. That imperfect spaying (in which one, or a part of one, ovary is left behind, while the bed is wholly or partly removed) sometimes happens is shown by the facts described in this paper.

The expenses of the investigation described in this paper have been very largely defrayed by a grant made by the Development Commissioners through the Board of Agriculture and Fisheries.
Lime-Sulphur Sprays, their Composition and Analysis
Authors: Ramsay A. A.
Published: March 2009

In a previous paper I have stated: “The monosulphide sulphur, therefore, appears to be essentially calcium hydroxyhydrosulphide CaHSOH with very minute quantities of calcium hydrosulphide CaH2S2. The solution of lime sulphur then appears to consist of calcium hydroxy-hydrosulphide, calcium thiosulphate, calcium sulphate with sulphur held in solution.”

I have now to amend this by adding “calcium disulphide” to the above.

The method of analysis is now as follows: Preparation of sample. 50 c.c. of the concentrated lime sulphur to be diluted to 500 c.c. with water.
The Relation of Certain Physical Characteristics of the Wheat Kernel to Milling Quality
Authors: Bailey C. H.
Published: March 2009

Kernel volume, because of its relation to the ratio of endosperm to non-endosperm structures, varies directly with the potential flour yield when comparisons are restricted to the same type or variety of wheat.

Accurate determination of kernel density must include the complete removal of all mechanically held air.
The ammoniacal nitrogen of peats and humus soils
Authors: Ellis J. C. B. , Morison C. G. T.
Published: March 2009

The detailed examination of humus soils of various kinds is becoming of increasing importance in view of the schemes now on foot for the reclamation of much heath and moor land. One of the most important things to establish has seemed to the authors to be the amount of nitrogen existing in the form of ammonia or of ammonium compounds, as it is possible that a knowledge of this figure might form a basis for a more scientific classification of soil organic matter than at present exists.