bluuebunny/crossref_metadata_2025 huggingface dataset:
Prevalence of radiographic changes in yearling and 2‐year‐old Quarter Horses intended for cutting
Authors: CONTINO E. K. , PARK R. D. , MC ILWRAITH C. W.
Published: August 2011

Reasons for performing study:There have been many studies that document radiographic findings in young Thoroughbred and Standardbred horses. No such studies have been performed in Quarter Horses.

Objective:To describe the prevalence of radiographic changes in the stifles, tarsi, carpi and fetlocks of young Quarter Horses intended for cutting.

Methods:Radiographs of yearling and 2‐year‐old Quarter Horses were obtained from a radiograph repository and a private farm. The carpi, tarsi, fetlocks and stifles were evaluated and radiographic changes categorised by type and location. The frequency of changes was calculated and comparisons were made between the 2 age groups.

Results:Of 458 included horses, 408 (89.1%) had radiographic changes, most of which were in the tarsi (304, 69.4%) followed by the stifles (202, 44.5%), hind fetlocks (155 of 355, 43.7%), fore fetlocks (131 of 361, 36.3%) and carpi (27 of 342, 7.9%). Of the horses with stifle changes, 188 (93.1%) were in the medial femoral condyle (MFC). There was a significant difference between the age groups for changes on the distal intermediate ridge of the tibia (DIRT), hindlimb middle phalanx (P2) osteophytes and proximal tibial osteophytes.

Conclusions:There is a high prevalence of radiographic changes in presale survey radiographs, especially in the stifles and tarsi, of young Quarter Horses intended for cutting.

Potential relevance:Veterinarians examining presale radiographs at cutting horse sales should expect a high prevalence of radiographic changes in this population of horses. Work to determine the clinical relevance of these radiographic changes is currently ongoing.
Deficits in emotion regulation associated with pathological gambling
Authors: Williams Alishia D. , Grisham Jessica R. , Erskine Alicia , Cassedy Eva
Published: August 2011

Objectives. The concept of emotion regulation features in many models of psychopathology and it has been proposed that individuals with poorly regulated emotions often engage in maladaptive behaviours to escape from or down‐regulate their emotions, creating risk for a range of disorders. One such disorder may be pathological gambling. To our knowledge, no study had assessed the use of emotion‐regulation strategies in this population. The goal of the present study was therefore to examine emotion‐regulation difficulties among a sample of pathological gamblers (n= 56), a mixed clinical comparison group (n= 50), and a sample of healthy community controls (n= 49).

Design. Multivariate analysis of variance controlling for age.

Methods. Participants were recruited from the community and a gambling treatment unit in Australia and completed clinical diagnostic interviews (ADIS‐IV; SCIP), self‐report measures of psychopathology (DASS‐21), substance use (AUDIT), and emotion‐regulation difficulties (DERS; ERQ).

Results. Pathological gamblers and the clinical comparison group reported significantly less use of reappraisal as an adaptive emotion‐regulation strategy, and reported a greater lack of emotional clarity and more impulsivity than individuals in the healthy community comparison group. Pathological gamblers reported a greater lack of emotional awareness compared to the healthy control group and reported differences in access to effective emotion‐regulation strategies compared to both comparison groups.

Conclusions. The results support specific deficits of emotion regulation in pathological gamblers and emphasize the need to address these underlying vulnerabilities in addition to directly targeting gambling behaviours in therapy.
Response to Dr Durrant's commentary: Making it useful
Authors: McMurran Mary
Published: August 2011

This article is an author response to Durrant's (2011) commentary on McMurran (2011).
Dynamic Modeling of a Piezoelectric Actuated Fuel Injector
Authors: Satkoski Chris A. , Shaver Gregory M. , More Ranjit , Meckl Peter , Memering Douglas , Venkataraman Shankar , Syed Jalal , Carmona-Valdes Jesus
Published: August 2011

As engine designers look for ways to improve efficiency and reduce emissions, piezoelectric actuated fuel injectors for common rail diesel engines have shown to have improved response characteristics over solenoid actuated injectors and may allow for enhanced control of combustion through multipulse, closely spaced injections or rate shaping. This paper outlines the development of an 11 state simulation model for a piezoelectric fuel injector and associated driver that can be used for injector design and control system verification. Nonmeasureable states of the model are plotted and analyzed, while measurable quantities including injection rate, piezo stack voltage, and piezo stack current are validated against experimental injector rig data for two different rail pressures.
Initial Input Selection for Iterative Learning Control
Authors: Freeman Chris T. , Alsubaie Muhammad Ali , Cai Zhonglun , Rogers Eric , Lewin Paul L.
Published: August 2011

Iterative learning control algorithms have been shown to offer a high level of performance both theoretically and when applied to practical applications. However, the trial-to-trial convergence of the error is generally highly dependent on the initial choice of input applied to the plant. Techniques are therefore developed, which generate an optimal initial input selection, and the effect this has on the error over subsequent trials is examined. Experimental benchmarking is undertaken using a gantry robot test facility.
Automotive Transmission Clutch Fill Control Using a Customized Dynamic Programming Method
Authors: Song Xingyong , Zulkefli Mohd Azrin Mohd , Sun Zongxuan , Miao Hsu-Chiang
Published: August 2011

Clutch to clutch shift control technology, which is the key enabler for a compact and low cost transmission design, is important for both automatic and hybrid transmissions. To ensure a smooth clutch to clutch shift, precise synchronization between the on-coming and off-going clutches is critical. This further requires the on-coming clutch to be filled and ready for engagement at the predetermined time. Due to the compact design, currently there is no pressure sensor inside the clutch chamber, and therefore the clutch fill can only be controlled in an open loop fashion. The traditional clutch fill approach, by which the clutch fill input pressure command is manually calibrated, has a couple of limitations. First, the pressure profile is not optimized to reduce the peak flow demand during clutch fill. Moreover, it is not systematically designed to account for uncertainties in the system, such as variations of solenoid valve delay and parameters of the clutch assembly. In this paper, we present a systematic approach to evaluate the clutch fill dynamics and synthesize the optimal pressure profile. First, a clutch fill dynamic model, which captures the key dynamics in the clutch fill process, is constructed and analyzed. Second, the applicability of the conventional numerical dynamic programming (DP) method to the clutch fill control problem, which has a stiff dynamic model, is explored and shown to be ineffective. Thus, we proposed a customized DP method to obtain the optimal and robust pressure profile subject to specified constraints. The customized DP method not only reduces the computational burden significantly, but also improves the accuracy of the result by eliminating the interpolation errors. To validate the proposed method, a transmission clutch fixture has been designed and built in the laboratory. Both simulation and experimental results demonstrate that the proposed customized DP approach is effective, efficient and robust for solving the clutch fill optimal control problem.
On the Influence of Structural Flexibility on Feedback Control Stability for Magnetically Suspended Vehicles
Authors: Alberts Thomas E. , Hanasoge Aravind M. , Omran Ashraf M.
Published: August 2011

This paper presents a simple analysis evaluating the stability threshold for magnetically levitated flexible structures using dissipative colocated controllers. It is shown that with such a control structure, the controller that stabilizes a rigid levitated mass can also stabilize a simple flexible structure with the same overall mass and electrodynamics. Experimental and simulation results are presented to validate this conclusion.
Blast Response Analysis of Reinforced Concrete Slabs: Experimental Procedure and Numerical Simulation
Authors: Morales-Alonso G. , Cendón D. A. , Gálvez, F. , Erice B. , Sánchez-Gálvez V.
Published: August 2011

A series of blast loading experiments are performed with the aim of providing experimental data for the development and adjustment of numerical tools needed in the modeling of concrete elements subjected to blast. To this end, an experimental setup that allows testing up to four concrete elements simultaneously under the same blast load is developed. Altogether four detonation tests are conducted, in which 12 slabs of two different concrete types are subjected to the same blast load. Results of the experimental program are validated by numerical simulation using two different material models for the prediction of concrete behavior. Major assets of the experimental setup presented are the reduction of scattering on detonation tests and its cost effectiveness. Results from tests and numerical simulations suggest that the ability of reinforced concrete structures of withstanding blast loads is primarily governed by their tensile strength.
The Potential of FOX-7 Explosive in Insensitive Munition Design
Authors: Cullis Ian G. , Townsley Richard
Published: August 2011

This paper describes research into the suitability of the explosive FOX-7 in the development of insensitive munitions. The analysis of experimental cylinder test data to generate a JWL equation of state and Gurney energy is described and the results compared with other published data. The JWL and Gurney energy are then used in analytical and hydrocode simulations to assess FOX-7 performance in fragmenting and slow stretching jet warheads and compared against other high performance explosives. The results of experiments to validate the simulations are presented and discussed.
Experimental Investigation on Dynamic Crack Propagating Perpendicularly Through Interface in Glass
Authors: Park Hwun , Chen Weinong W.
Published: August 2011

Dynamic crack propagation across a perpendicular interface in a glass specimen was investigated to understand the interaction between the crack and the interface under impact loading. The glass specimen was composed of two glass plates in an edge-to-edge configuration with an adhesive layer in between. One of the plates had a notch for a plastic projectile to strike. A single crack developed from the notch tip, and propagated perpendicularly into the interface. The patterns of crack propagation across the interface depend on the adhesive conditions on the interface. Within a range of impact speeds, the crack is arrested at the interface without any adhesive. The crack passes across a firmly bonded interface with little obstruction by the interface. The crack branches into multiple cracks after it passes through a thicker interface filled with adhesive. Projectiles having higher kinetic energies cause more severe crack branching after the crack extends into the second glass plate.
Multi-Dimensional Two-Phase Flow Modeling Applied to Interior Ballistics
Authors: Nussbaum Julien , Helluy Philippe , Herard Jean-Marc , Baschung Barbara
Published: August 2011

Complex phenomena occur in a combustion chamber during a ballistic cycle. From the ignition of the black powder in the primer to the exit of the projectile through the muzzle, two-phase gas-powder mix undertakes various transfers in different forms. A detailed comprehension of these effects is fundamental to predict the behavior of the whole system, considering performances and safety. Although the ignition of the powder bed is three-dimensional due to the primer’s geometry, simulations generally only deal with one- or two-dimensional problem. In this study, we propose a method to simulate the two-phase flows in 1, 2 or 3 dimensions with the same system of partial differential equations. A one-pressure, conditionally hyperbolic model [1] was used and solved by a nonconservative finite volume scheme associated to a fractional step method, where each step is hyperbolic. We extend our study to a two-pressure, unconditionally hyperbolic model [2] in which a relaxation technique was applied in order to recover the one-pressure model by using the granular stress. The second goal of this study is also to propose an improved ignition model of the powder grains, by taking into account simplified chemical kinetics for decomposition reactions in the two phases. Here we consider a 0th-order solid decomposition and an unimolecular, 2nd-order gas reaction. Validation of the algorithm on several test cases is presented.
In-Bore Yaw Effects on Lateral Throw-off and Aerodynamic Jump Behavior for Small Caliber Projectiles Firing Sidewise From Air Vehicles
Authors: Gkritzapis Dimitrios N. , Panagiotopoulos Elias E.
Published: August 2011

The present study investigates the effects of in bore-yaw phenomenon on lateral throw-off and aerodynamic jump behavior for small caliber rotational symmetric (both in configuration and mass distribution) projectiles launched horizontally at supersonic firing speeds and various altitudes from high-subsonic air vehicles. The ammunition used is the caliber .50 API M8 bullet type firing from M2 machine automatic gun. The projectile is considered to be eccentrically engraved, tilted as it enters the rifling, and it is assumed that the tilt persists throughout its passage through the rifled barrel of the used weapon system. The modified linear 6-DOF flight simulation modeling is applied for the bullet free-flight trajectory predictions. The coupled epicyclic pitching and yawing motion analysis for the first 100 m of the examined trajectories are taken into account.
Internal Ballistics Simulation of a NAWC Tactical SRM
Authors: Cavallini Enrico , Favini B. , Di Giacinto M. , Serraglia F.
Published: August 2011

In the design and development of solid propellant rocket motors, the use of numerical tools able to predict the behavior of a given motor is particularly important in order to decrease the planning times and costs. This paper is devoted to present the results of the internal ballistics numerical simulation of the NAWC tactical motor n. 6, from ignition to burn-out, by means of a quasi-one-dimensional unsteady numerical simulation model, SPINBALL, coupled with a three-dimensional grain burnback model, GREG. In particular, the attention is focused on the effects on the SRM behavior of the erosive burning, total pressure drops and the cause of the pressure overpeak occurring during the last part of the ignition transient. The final objective is to develop an analysis/simulation capability of SRM internal ballistics for the entire combustion time with simplified physical models, in order to have reduced the computational costs, but ensuring an accuracy greater than the one usually given by zero-dimensional models. The results of the simulations indicate a very good agreement with the experimental data, as no attempt of submodels calibration is made, enforcing the ability of the proposed approach to predict the SRMs internal flow-field conditions. The numerical simulations show that NAWC n. 6 internal ballistics is completely led by the erosive burning, that is the root cause of the pressure peak occurring immediately after the SRM start-up.
An Experimental and Numerical Study of Ballistic Impacts on a Turbine Casing Material at Varying Temperatures
Authors: Erice B. , Gálvez F. , Cendón D. A. , Sánchez-Gálvez V. , Børvik T.
Published: August 2011

An experimental and numerical study of ballistic impacts on steel plates at various temperatures (700 °C, 400 °C and room temperature) has been carried out. The motivation for this work is the blade-off event that may occur inside a jet engine turbine. However, as a first attempt to understand this complex loading process, a somewhat simpler approach is carried out in the present work. The material used in this study is the FV535 martensitic stainless steel, which is one of the most commonly used materials for turbine casings. Based on material test data, a Modified Johnson-Cook (MJC) model was calibrated for numerical simulations using the LS-DYNA explicit finite element code. To check the mesh size sensitivity, 2D axisymmetric finite element models with three different mesh sizes and configurations were used for the various temperatures. Two fixed meshes with 64 and 128 elements over the 2 mm thick plate and one mesh with 32 elements over the thickness with adaptive remeshing were used in the simulations. Both the formation of adiabatic shear bands in the perforation process and the modeling of the thermal softening effects at high temperatures have been found crucial in order to achieve good results.
Methodology to Assess Potential Glint and Glare Hazards From Concentrating Solar Power Plants: Analytical Models and Experimental Validation
Authors: Ho Clifford K. , Ghanbari Cheryl M. , Diver Richard B.
Published: August 2011

With a growing number of concentrating solar power systems being designed and developed, the potential impact of glint and glare from concentrating solar collectors and receivers is receiving increased attention as a potential hazard or as a distraction for motorists, pilots, and pedestrians. This paper provides analytical methods to evaluate the irradiance originating from specularly and diffusely reflecting sources as a function of distance and characteristics of the source. Sample problems are provided for both specular and diffuse sources, and validation of the models is performed via testing. In addition, a summary of safety metrics is compiled from the literature to evaluate the potential hazards of calculated irradiances from glint and glare for short-term exposures. Previous safety metrics have focused on prevention of permanent eye damage (e.g., retinal burn). New metrics used in this paper account for temporary after-image, which can occur at irradiance values several orders of magnitude lower than the irradiance values required for irreversible eye damage.
Mutations in
CIC
and
FUBP1
Contribute to Human Oligodendroglioma
Authors: Bettegowda Chetan , Agrawal Nishant , Jiao Yuchen , Sausen Mark , Wood Laura D. , Hruban Ralph H. , Rodriguez Fausto J. , Cahill Daniel P. , McLendon Roger , Riggins Gregory , Velculescu Victor E. , Oba-Shinjo Sueli Mieko , Marie Suely Kazue Nagahashi , Vogelstein Bert , Bigner Darell , Yan Hai , Papadopoulos Nickolas , Kinzler Kenneth W.
Published: August 2011

A gene originally studied for its role in fruit fly embryogenesis is implicated in the growth of a common human brain tumor.
Reproductive physiology of the pig ‐ theory into practice
Authors: White Mark
Published: August 2011

THE productivity of the pig breeding herd is usually measured in terms of the number of pigs reared within a given time period by each sow. In simple terms, the aim is to produce as many litters within the time period as possible (ie, minimising lost or empty days) and to rear as many pigs as possible from each litter. This article examines the physiology of the gilt/sow and litter at the different stages of the production cycle and discusses how management, and nutrition in particular, can influence the breeding outcome.
‘Why, why did you have me treated?’: the psychotic experience in a literary narrative: Figure 1
Authors: Kaptein A A , Koopman J J E , Weinman J A , Gosselink M J
Published: August 2011

In this paper, the authors suggest an approach that may be helpful in teaching medical humanities to medical students. In the context of an honours class on medicine and literature, students (1) read a novel on an illness, (2) interviewed a patient with the medical condition described in the novel and (3) wrote an essay on the biomedical, narrative and literary aspects of these sources of information. The authors compared the story of Chekhov's literary protagonist Kovrin inThe Black Monkwith the personal story of patient H., who was diagnosed with schizophrenia. The narratives of the two patients were compared, based on Chekhov's literary narrative and the narrative of the patient. Both patients appeared to somehow regret losing their symptoms, following various psychiatric treatments. Both narratives show the ambivalence between the gain and loss that adequate psychiatric treatment may bring. Studying novels and other literary sources may help in understanding the story of the patient better, with associated improvements in various aspects of medical outcome. Reading literary fiction may help to increase an understanding of patients' emotions, experiences, cognitions and perspectives. It may also reduce the emotional distance between the self and the patient. The educational approach that was explored in the authors' honours class may be helpful to others when developing methods for teaching medical humanities to (medical) students.
Genetic and archaeological evidence for a former breeding population of Aleutian Cackling Goose (Branta hutchinsii leucopareia) on Adak Island, central Aleutians, Alaska
Authors: Wilson B.J. , Crockford S.J. , Johnson J.W. , Malhi R.S. , Kemp B.M.
Published: August 2011

Many well-preserved bones of medium-sized goose have been recovered from the Zeto Point archaeological site (ADK-011) on Adak Island in the central Aleutians, Alaska, that date to ca. 170–415 years before present based on conventional radiometric dates of the deposits. This prehistoric sample includes remains of adults and unfledged goslings that defied confident identification based on osteological criteria. While the presence of newborns indicates that Adak was a breeding ground, which species was doing the nesting remained uncertain. Of the five species of medium-sized goose (order Anseriformes, family Anatidae) known or presumed to visit Adak Island, three are rarely sighted. The only common visitor is the Emperor Goose ( Chen canagica (Sevastianov, 1802)). The Aleutian Cackling Goose ( Branta hutchinsii leucopareia (Brandt, 1836)) breeds elsewhere in the Aleutians but does not currently breed on Adak Island and there are no records of it nesting there in the past. Here DNA sequences from portions of the cytochrome b (cytb) gene and the control region (CR) of the mitochondrial genome were recovered from 28 of 29 Adak prehistoric goose remains. All adult specimens identified to species were either C. canagica or B. h. leuopareia, but all specifically identified juvenile specimens were B. h. leuopareia. The results demonstrate that Adak Island was a breeding ground of the Aleutian Cackling Goose prior to European contact.
Natal experience and conspecifics influence the settling behaviour of the juvenile terrestrial isopod Armadillidium vulgare
Authors: Robinson B.G. , Larsen K.W. , Kerr H.J.
Published: August 2011

Cues used by dispersing juveniles to assess habitat quality can be based on public information available to all individuals or on private information obtained from experience in the natal habitat. The presence of conspecifics (public information) and natal habitat quality (private information) have been shown to influence habitat preferences in many species, but the relative importance of these two cue types is seldom investigated. We examined whether habitat quality relative to the natal habitat had a stronger influence on the settling decisions of the juvenile terrestrial isopod Armadillidium vulgare (Latreille, 1804), than sign of conspecifics. We raised juvenile A. vulgare in either high- or low-quality habitats and then observed how the presence of conspecific sign influenced their preference for each of these habitats. When conspecific sign was absent, juveniles preferred high-quality habitat, regardless of their natal habitat. When the low-quality habitat was treated with conspecific sign, juveniles born on low-quality habitat continued to prefer the high-quality habitat, but juveniles raised on high-quality habitat displayed no preference. This suggests juvenile isopods respond to these cues hierarchically: they first search for habitats higher in quality than their natal habitat and then cue into conspecific sign when the preferred habitat is unavailable.
Fast and slow life histories of carnivores
Authors: Paemelaere Evi , Dobson F. Stephen
Published: August 2011

The fast–slow continuum hypothesis explains life-history traits as reflecting the causal influence of mortality patterns in interaction with trade-offs among traits, particularly more reproductive effort at a cost of shorter lives. Variation among species of different body sizes produce more or less rapid life cycles (respectively, from small to large species), but the fast–slow continuum remains for birds and mammals when body-size effects are statistically removed. We tested for a fast–slow continuum in mammalian carnivores. We found the above trade-offs initially supported in a sample of 85 species. Body size, however, was strongly associated with phylogeny (ρ = 0.79), and thus we used regression techniques and independent contrasts to make statistical adjustments for both. After adjustments, the life-history trade-offs were not apparent, and few associations of life-history traits were significant. Litter size was negatively associated with age at maturity, but slightly positively associated with offspring mass. Litter size and mass were negatively associated with the length of the developmental period. Gestation length showed weak but significant negative associations with age at maturity and longevity. We conclude that carnivores, despite their wide range of body sizes and variable life histories, at best poorly exhibited a fast–slow continuum.
Demography of a harvested population of wolves (Canis lupus) in west-central Alberta, Canada
Authors: Webb N.F. , Allen J.R. , Merrill E.H.
Published: August 2011

Wolves ( Canis lupus L., 1758) are subject to liberal public harvests throughout most of their range in North America, yet detailed information on populations where sport harvest is the primary source of mortality are limited. We studied a harvested wolf population in west-central Alberta from 2003 to 2008. Demographic data were collected from visits to den sites, 84 collared wolves from 19 packs, and a harvest monitoring program that augmented mandatory reporting for registered traplines. Annual harvest rate of wolves was 0.34, with harvest on registered traplines (0.22 ± 0.03) being twice that of hunters (0.12 ± 0.04). Most wolves harvested (71%) were pre-reproductive. Probability of a pack breeding was 0.83 ± 0.01, litter size averaged 5.6 ±1.4, and these rates and stability of home ranges were unaffected by the number of wolves harvested. Natural mortality (0.04 ± 0.03) and dispersal rates (0.25 ± 0.04) were lower than reported for wolf populations in protected areas. Reproductive rates balanced total wolf mortality, indicating harvest was likely sustainable. We suggest that a high proportion of juveniles harvested and the spatial structure of the registered trapline system contributed to the sustainability of harvests.
Impacts of generalist mesopredators on the demography of small-mammal populations in fragmented landscapes
Authors: Eagan Timothy S. , Beasley James C. , Olson Zachary H. , Rhodes Olin E.
Published: August 2011

A consequence of the reduction and subsequent fragmentation of native habitats has been the loss or severe reduction of specialist predator populations from these altered ecosystems, resulting in a “release” of generalist predators. Demographic aspects of small-rodent populations, especially predator-driven density cycles, have been extensively studied. However, the majority of studies examining predator–prey dynamics have been conducted in relatively undisturbed ecosystems, while more limited data are available for regions that have been greatly modified by human settlement. Using raccoons ( Procyon lotor (L., 1758)) and white-footed mice ( Peromyscus leucopus (Rafinesque, 1818)) as focal species, we used an experimental framework to evaluate the hypothesis that generalist mesopredators limit small-mammal abundance in landscapes that have been significantly altered by human land use. Both parametric and nonparametric analyses indicated that populations of white-footed mice exhibited a significant increase (32%) in density where raccoon abundance was reduced when compared with control populations. Our study highlights an important role that superabundant mesopredators can play in ecosystems through the limitation of secondary prey populations. This research suggests that further investigation of the trophic dynamics of agricultural ecosystems is critical if we are to elucidate the fundamental ecological mechanisms associated with the persistence of species in disturbed environments.
Effects of ENSO-linked climate and vegetation on population dynamics of sympatric rodent species in semiarid grasslands of Inner Mongolia, China
Authors: Jiang G. , Zhao T. , Liu J. , Xu L. , Yu G. , He H. , Krebs C.J. , Zhang Z.
Published: August 2011

El Niño Southern Oscillation (ENSO) linked climate has been known to be associated with several rodent species, but its effects on rodent community at both spatial and temporal scales are not well studied. In this study, we investigated the possible causal chain relating ENSO, precipitation, temperature, and vegetation index (normalized difference vegetation index, NDVI) to rodent abundance for 14 sympatric rodent species in 21 counties of semiarid grasslands in Inner Mongolia, China, from 1982 to 2006. We found that both precipitation and temperature showed a generally direct positive effect on rodent abundance in many species in the current year, but indirect effects that operate through NDVI in the current or following year could have a reverse effect on abundance. We described one ENSO-linked precipitation bottom-up chain and three ENSO-linked temperature bottom-up chains. These observed bottom-up links reveal that in El Niño years, or 1 year after La Niña years, or 2 years after El Niño years, ENSO-driven climate or vegetation factors tend to increase population abundances of many sympatric rodent species in this region. We also found time-lag effects and the life-history strategy (i.e., functional groups of hibernating behavior, activity rhythm, or food habits) also contribute to the observed complicated effects of SOI on precipitation, temperature, NDVI, and ultimately rodent abundance.
THE VARIATION OF EXCHANGE CONSTANT AND MAGNETOCALORIC EFFECT IN LaFe13-xSix (x = 1.6, 1.9 AND 2.2) COMPOUNDS
Authors: IZGI T. , KOLAT V. S. , GENCER H. , ATALAY S.
Published: August 2011

In this work, we present the variation of exchange constant (J exc ) and magnetocaloric effect (MCE) in LaFe 13-x Si x (x = 1.6, 1.9 and 2.2) compounds. NaZn 13-type LaFe 13-x Si x intermetallic compounds were prepared by arc melting in an atmosphere of highly pure argon gas. X-ray results indicated a slight decrease of lattice parameter with increasing Si content. The maximum magnetic entropy change of the LaFe 13-x Si x (x = 1.6, 1.9 and 2.2) samples decreases with increasing Si contents. Also, the magnetic entropy change was calculated theoretically at various magnetic fields and compared with experimental data. The spin-wave dispersion coefficients (D) and exchange constants (J exc ) were calculated for the fist time for these samples. It was found that D and J exc increase with increasing Si content.
EXACT SOLUTIONS OF COUPLED KdV EQUATION DERIVED FROM THE COUPLED NLS EQUATION USING MULTIPLE SCALES METHOD
Authors: TAŞCAN FILIZ , BEKIR AHMET
Published: August 2011

In this paper, we have considered a generalized coupled higher-order nonlinear Schrödinger equations. We applied multiple scales method to coupled higher-order nonlinear Schrödinger equations to derive the coupled KdV equation. Then, the extended tanh method is applied to derived coupled KdV equation for exact solutions. The obtained results include solitary wave solutions.
CONSTRUCTION OF SnO2/SiO2/Si HETEROJUNCTION AND ITS LINEUP USING I–V AND C–V MEASUREMENTS
Authors: SALEM EVAN T. , AGOOL IBRAHIM R. , HASSAN MARWA A.
Published: August 2011

Near-ideal n- SnO 2/n- Si heterojunction band edge lineup has been investigated with aid of I–V and C–V measurements. The heterojunction was manufactured by rapid thermal oxidation of Sn metal films prepared by thermal evaporation technique on monocrystalline n-type silicon. The experimental data of the conduction band offset ΔEc and valence band offset ΔEc were compared with theoretical values. The band offset ΔEc = 0.55 eV and ΔEv = 1.8 eV obtained at 300 K. The energy band diagram of n- SnO 2/n- Si HJ was constructed. C–V measurements depict that the junction was an abrupt type and the built-in voltage was determined from 1/C2–V plot.
POMERANCHUK INSTABILITIES IN MULTICOMPONENT LATTICE SYSTEMS AT FINITE TEMPERATURE
Authors: LAMAS C. A. , CABRA D. C. , GRANDI N. E.
Published: August 2011

In the present paper we extend the method to detect Pomeranchuk instabilities in lattice systems developed in previous works to study more general situations. The main result presented here is the extension of the method to include finite temperature effects, which allows to compute critical temperatures as a function of interaction strengths and density of carriers. Furthermore, it can be applied to multiband problems which would be relevant to study systems with spin/color degrees of freedom. Altogether, the present extended version provides a potentially powerful technique to investigate microscopic realistic models relevant to the Fermi liquid to nematic transition extensively studied in connection with different materials such as cuprates, ruthenates, etc.
SHOT NOISE IN NORMAL-FERROMAGNETIC-NORMAL GRAPHENE
Authors: RASHIDIAN Z. , KHEIRANDISH F.
Published: August 2011

In this paper the transport properties of normal-ferromagnetic-normal graphene structures are studied by the Landauer Büttiker approach. The properties of spin chiral ferromagnetic layer are investigated when exchange energy exceeds the Fermi energy. To this end, the conductance as well as the shot noise are calculated. The Pauli exclusion principle that acts only on the carriers with the same spin, reduces the shot noise from its Schottky value. The effects of shot noise on the carriers with opposite spins in a ferromagnetic graphene are considered and it is observed that in this case the shot noise is lower than that of non-graphene systems since the quasiparticles with opposite spins are correlated due to chirality. In this way we report a new source of fluctuations in spin chiral materials.
TEMPERATURE DEPENDENCE OF SPIN CURRENTS CARRIED BY JORDAN–WIGNER FERMIONS AND MAGNONS IN INSULATORS
Authors: NAKATA KOUKI
Published: August 2011

The temperature dependence of spin currents in insulators at the finite temperature near zero Kelvin is theoretically studied. The spin currents are carried by Jordan–Wigner fermions and magnons in one- and three-dimensional insulators. These spin currents are generated by the external magnetic field gradient along the quantization axis and also by the two-particle interaction gradient. In one-dimensional insulators, quantum fluctuations are strong and the spin current carried by Jordan–Wigner fermions shows the stronger dependence on temperatures than the one by magnons.
EXTERNAL FIELD INFLUENCE ON SEMIFLEXIBLE MACROMOLECULES: GEOMETRIC COUPLING
Authors: BELLUCCI STEFANO , MAMASAKHLISOV YEVGENY , NERSESSIAN ARMEN
Published: August 2011

We suggested a geometric approach to address the external field influence on the DNA molecules, described by the WLC model via geometric coupling. It consists in the introduction of the effective metrics depending on the potential of the external field, with further re-definition of the arc-length parameter and of the extrinsic curvatures of the DNA molecules. It yields the nontrivial impact of the external field in the internal energy of macromolecules. We give the Hamiltonian formulation of this model and perform its preliminary analysis in the redefinition of the initial energy density.
CRITICAL DIMENSIONS OF SYSTEMS WITH JOINT MULTICRITICAL AND LIFSHITZ-POINT-LIKE BEHAVIOR
Authors: BABICH ARTEM V. , KITCENKO LESYA N. , KLEPIKOV VYACHESLAV F.
Published: August 2011

In this article, we consider a model that allows one to describe critical phenomena in systems with higher powers and derivatives of order parameter. The systems considered have critical points with joint multicritical and Lifshitz-point-like properties. We assess the lower and upper critical dimensions of these systems. These calculation enable us to find the fluctuation region where the mean field theory description does not work.
QUANTUM CONFINED STARK EFFECT ON INTERSUBBAND TRANSITIONS IN STRAINED WURTZITE NITRIDE QUANTUM WELLS
Authors: HA SI HUA , BAN SHI LIANG , ZHU JUN
Published: August 2011

The quantum confined Stark effect on the optical absorption of intersubband transitions in nitride quantum wells is investigated by means of the density matrix formulism. The built-in electric field, which is caused by the piezoelectric polarization produced by the lattice mismatch and thermal strain, and by the spontaneous polarization, is taken into account. The three-energy-level system is obtained by designing a quantum-well structure composed by two barriers with different band gaps. For example, the corresponding wavelengths for 1–2, 1–3 and 2–3 transitions in an Al 0.5 Ga 0.5 N / In 0.3 Ga 0.7 N / GaN quantum well with the well width of 5 nm are calculated as 1.84 μm, 0.95 μm and 2.24 μm, respectively. Moreover, they decrease with increasing the Al composition of left barrier.
COMPARATIVE STUDY OF ELECTRONIC PROPERTIES OF GRAPHITE AND HEXAGONAL BORON NITRIDE (h-BN) USING PSEUDOPOTENTIAL PLANE WAVE METHOD
Authors: KALONI THANESWOR P. , MUKHERJEE SUGATA
Published: August 2011

We studied various ground state properties, e.g. cohesive energy, exfoliation energy, equilibrium lattice constants, elastic constant (C33), compressibility, band structure, density of states and charge density of Graphite, Graphene and Hexagonal Boron Nitride (h- BN ) using pseudopotential plane wave method. Most of the calculated physical quantities of graphite are found to be close to those of h- BN and these are in good agreement with available experimental data.
REINFORCEMENT LEARNING IN NON-MARKOV CONSERVATIVE ENVIRONMENT USING AN INDUCTIVE QUALITATIVE MODEL
Authors: JOVIĆ FRANJO , SLAVEK NINOSLAV , BLAŽEVIĆ DAMIR
Published: August 2011

The majority of real-world processes, such as power plants, banking and retail businesses, are non-Markov processes, being conservative systems with stochastic supply and demand. As an example, a retail process possesses long-term memory of the customer's experience and market price drift that deviates from the Markov property. Modeling the reward in this process is directed towards actions that have to be executed daily in order to support it. These actions are further severely distracted by the hidden periodicity of customer behavior on a monthly and weekly basis. Alternative solutions in the retail business are achieved using a retail potential market model and a pricing policy based on demography. The policy of non-Markov behavior has not been intensively studied, although the literature indicates the non-Markov nature of many real process models, such as bank rating migrations. A solution is proposed, based on day-to-day data collection from point-of-sale (POS) locations, synthesizing the reward function from separate sale component rewards using qualitative models, and indicating the most outstanding sale groups that form the reward model. The normalization of POS data has been used for the elimination of periodicities and of non-Markov features of the process data. Reinforcement learning has been additionally supported by artificial corrections of the normalized reward function, and thus the obtained models used for recognition of the most promising and most defective hidden retail product groups. Model data were analyzed for the statistical significance of the obtained results, comparing normalized and non-normalized sales data distributions. The method is simple and effective, being applicable to each POS separately, for a complex retail business network, as well as for other conservative environments. The obtained qualitative correlations of model and reward function lie between 0.72 and 0.95, even for the simple cases presented.
STR: A GRAPH-BASED TAGGING TECHNIQUE
Authors: ORTEGA F. JAVIER , TROYANO JOSÉ A. , GALÁN FRANCISCO J. , VALLEJO CARLOS G. , CRUZ FERMÍN
Published: August 2011

This paper presents the ideas, experiments and specifications related to the Supervised TextRank (STR) technique, a word tagging method based on the TextRank algorithm. The main innovation of STR technique is the use of a graph-based ranking algorithm similar to PageRank in a supervised fashion, gathering the information needed to build the graph representations of the text from a tagged corpus. We also propose a flexible graph specification language that allows to easily experiment with multiple configurations for the topology of the graph and for the information associated to the nodes and the edges. We have carried experiments in the Part-Of-Speech task, a common tagging problem in Natural Language Processing. In our best result we have achieved a precision of 96.16%, at the same level of the best tagging tools.
RINGS OVER WHICH FLAT COVERS OF SIMPLE MODULES ARE PROJECTIVE
Authors: BÜYÜKAŞIK ENGIN
Published: August 2011

Let R be a ring with identity. We prove that, the flat cover of any simple right R-module is projective if and only if R is semilocal and J(R) is cotorsion if and only if R is semilocal and any indecomposable flat right R-module with unique maximal submodule is projective.
RELATIVE COHERENCE OF RINGS
Authors: MAO LIXIN , DING NANQING
Published: August 2011

Let R be a ring and τ a hereditary torsion theory for the category of all left R-modules. A right R-module M is called τ-flat if Tor 1(M, R/I) = 0 for any τ-finitely presented left ideal I. A left R-module N is said to be τ-f-injective in case Ext 1(R/I, N) = 0 for any τ-finitely presented left ideal I. R is called a left τ-coherent ring in case every τ-finitely presented left ideal is finitely presented. τ-coherent rings are characterized in terms of, among others, τ-flat and τ-f-injective modules. Some known results are extended.
FINITE GROUPS WITH WEAKLY S-QUASINORMALLY EMBEDDED SUBGROUPS
Authors: YANG NANYING , GUO WENBIN , HUANG JIANHONG , XU MANHONG
Published: August 2011

Let H be a subgroup of a group G. A subgroup H of G is said to be S-quasinormally embedded in G if for each prime p dividing |H|, a Sylow p-subgroup of H is also a Sylow p-subgroup of some S-quasinormal subgroup of G. We say that H is weakly S-quasinormally embedded in G if there exists a normal subgroup T of G such that HT ⊴ G and H ∩ T is S-quasinormally embedded in G. In this paper, we investigate further the influence of weakly S-quasinormally embedded subgroups on the structure of finite groups. A series of known results are generalized.
FINITE GROUPS ALL OF WHOSE NON-NORMAL SUBGROUPS POSSESS THE SAME ORDER
Authors: ZHANG JUNQIANG
Published: August 2011

In this note, finite groups all of whose non-normal subgroups possess the same order are classified up to isomorphism.
Tunable Omnidirectional Total Reflection Frequency Range in One-Dimensional Photonic Crystals Based on the Faraday Effect
Authors: Tian Huiping , Ji Yuefeng
Published: August 2011

We report that tunable omnidirectional total reflector can be realized theoretically with one-dimensional (1D) photonic crystals (PCs) by adding external magnetic fields. The 1D PCs consist of two alternating layers with SiO2 and InSb. We show that the 1D PCs have rather large omnidirectional photonic band gaps (omni-PBGs). After being added external magnetic fields the omni-PBGs will be tuned accordingly. The shift ranges of left and right circular polarizations are different. As a result, the omnidirectional reflector and omnidirectional circular polarizer can be realized.
Fast-response, Low-Afterglow 4,4'''-Bis[(2-butyloctyl)oxy]-1,1':4',1'':4'',1'''-quarterphenyl Dye-Based Liquid Scintillator for High-Contrast Detection of Laser Fusion-Generated Neutrons
Authors: Nagai Takahiro , Ioka Yusuke , Hasegawa Ai , Wada Kazuhiro , Takaoku Shingo , Takata Masatoshi , Noritake Katsuya , Minami Yuki , Watanabe Kozue , Yamanoi Kohei , Arikawa Yasunobu , Hosoda Hirokazu , Nakamura Hirotaka , Watari Takeshi , Cadatal-Raduban Marilou , Koga Mayuko , Shimizu Toshihiko , Sarukura Nobuhiko , Shiraga Hiroyuki , Nakai Mitsuo , Norimatsu Takayoshi , Azechi Hiroshi
Published: August 2011

4,4'''-Bis[(2-butyloctyl)oxy]-1,1':4',1'':4'',1'''-quaterphenyl (BBQ) dye dissolved in xylene and enriched with oxygen is shown to exhibit the characteristics of an ideal neutron scintillator for time-of-flight (TOF) measurement in a laser fusion experiment. Initial results from excitation with 290-nm pulses show that it has a 0.76-ns fast decay component and a negligible slow decay component or afterglow. By using this scintillator for TOF measurement, we have successfully discriminated between nuclear fusion-generated neutrons and X-rays. This would dramatically improve neutron diagnostics in fast ignition experiments where neutrons have to be detected in the presence of an intense X-ray burst.
On Refining the Relationship between Aspect Ratio and Percolation Threshold of Practical Carbon Nanotubes/Polymer Nanocomposites
Authors: Dang Zhi-Min , Shehzad Khurram , Zha Jun-Wei , Hussain Tajamal , Jun Nie , Bai Jinbo
Published: August 2011

Four different aspect ratio (AR) based multiwall carbon nanotube (MWNT)/thermoplastic elastomer (TPE) polymer nanocomposites were fabricated by melt blending. In contrast to proposed mathematical models, electrical percolation thresholds of resulting nanocomposites displayed an oscillating, non-monotonic relation with increase in AR. Experimental results suggested that mathematically calculated nominal AR of MWNT was an unclear parameter to predict the percolation threshold of polymer nanocomposites. Instead, a more clear approach taking into consideration the diameter and length of nanotubes individually rather as a combined parameter of AR explained fairly well the relation between MWNT dimensions and percolation threshold.
Screening Effects on the Ion–Ion Collisions in Nonideal Dense Metal Plasmas
Authors: Ki Dae-Han , Jung Young-Dae
Published: August 2011

The plasma screening and quantum effects on ion–ion collisions are investigated in a nonideal Al and Cu dense metal plasma. Eikonal analysis and the effective pseudopotential model of the quantum–mechanical and plasma screening effects are used to obtain the eikonal phase shift and eikonal cross section for the ion–ion collision as functions of the impact parameter, collision energy, de Broglie wavelength, and Debye length in nonideal metal plasmas. The result shows that the plasma screening effect is more important than the quantum–mechanical effect in ion collisions in nonideal metal plasmas. The result shows that the eikonal phase shift decreases with an increase in the quantum–mechanical effect. Note that the Al–Cu ion collision cross section is found to be greater than the Al–Al and Cu–Cu ion collision cross sections in a dense metal plasma.