bluuebunny/crossref_metadata_2025 huggingface dataset:
Model-Based Design and Evaluation of Electric Vehicle Powertrain With Independent Driving Motors
Authors: Wu Haotian , Zhang Haiyan
Published: January 2016

The transfer case based all-wheel drive electric vehicle (TCAWDEV) and dual-axle AWDEV have been investigated to balance concerns about energy consumption, drivability and stability of vehicles. An ideal AWDEV (IAWDEV) powertrain architecture is proposed by this research; the architecture has an independent driving motor at each wheel; in essence, the IAWDEV is a distributed powertrain that provides various combinations of torque vector control. This research also investigated the simplified methods to estimate the battery capacity and the operation envelope of motors, and employed model-based evaluation approaches to recursively identify the proper powertrain components. The model-based evaluation was conducted in LMS AMESim. The results show that the IAWDEV could reduce the complexity of drivetrain, and also can harvest more braking energy under poor road contact.
Modelling of Cusp Geometry in Additive Manufacturing Parts Using a Piece-Wise Polynomial
Authors: Kaji Farzaneh , Barari Ahmad
Published: January 2016

The final dimensional and geometric inaccuracies, and the resulting high surface roughness of the products have been the major problems in employing Additive Manufacturing (AM) technologies. Most of commonly used Additive manufacturing (AM) technologies are developed based on a layer-based manufacturing process to fabricate 3D models. The main critical issue in AM which reduces the surface integrity of the final products is the stair case error which happens due to layer by layer manufacturing process.

A new method is presented to model the surface roughness of FDM parts based on considering a new geometry for the cusps. Variety of observations were conducted to model the exact geometry of the cusp. Considering that cusp geometry affects the surface roughness directly, the new geometry was used to predict the surface roughness distribution as a function of layer thickness and surface angle of the final FDM products.

The model was validated by designing a set of experiments using 3D measurements of the surface roughness under high resolution surface topography device and the predicted model was in a good agreement with the experimental results.
Machine Specific Energy Consumption Analysis for CNC-Milling Toolpaths
Authors: Pavanaskar Sushrut , McMains Sara
Published: January 2016

This paper describes our work on analyzing and modeling energy consumption in CNC machining with an emphasis on the geometric aspects of toolpaths. We address effects of geometric and other aspects of toolpaths on energy consumed in machining by providing an advanced energy consumption model for CNC machining. We performed several controlled machining experiments to isolate, identify, and analyze the effects of various aspects of toolpaths (such as path parameters, angular change, etc.) on energy consumption. Based on our analyses, we developed an analytical energy consumption model for CNC machining that, along with the commonly used input of material removal rate (MRR), incorporates the effects of geometric toolpath parameters as well as effects of machine construction when estimating energy requirements for a toolpath. We also developed a simple web-based software interface to our model, that, once customized for a particular CNC machine, provides energy requirement estimates for a toolpath given its G/M code. Such feedback can help process planners and CNC machine operators make informed choices when generating/selecting toolpath alternatives using commercial CAM software.
Towards Automatic Gait Assessment by Means of RGB-D Mocap
Authors: Regazzoni Daniele , Rizzi Caterina , Comotti Claudio , Massa Federico
Published: January 2016

The present paper describes the research done to empirically validate the use of RGB-D cameras for orthopedic rehabilitation purposes. In order to assess the outcome of optical sensors a set of new generation inertial sensors have been adopted as well. Both kind of sensors have been used to track the same scene simultaneously in order to have comparable results. The aim of the work is provide evidence of performances of the newly introduced sensors (optical and inertial) and to automate acquisition and data elaboration in the medical field. The extraction of the only meaningful data from a gait, for instance, gives the change to perform an automatic preliminary analysis on normal people as well as on patients with known pathologies or disorders. In particular, this could allow determining without human intervention any standard disorders, according to literature classifications, eventually affecting the gait. The automatic procedure from acquisition to diagnosis constitutes a challenging topic of research and a success in terms of reliability, usability and physiological acceptance by technicians would radically impact medical practices in orthopedic rehabilitation centers.
High Penetration Residential Solar Photovoltaics and the Effects of Dust Storms on System Net Load
Authors: Janko Samantha A. , Gorman Brandon T. , Singh Uday P. , Johnson Nathan G.
Published: January 2016

Residential solar photovoltaic (PV) systems are becoming increasingly common around the world. Much of this growth is attributed to a decreasing cost of solar PV modules, reduction in the cost of installation and other “soft costs,” along with net-metering, financial incentives, and the growing societal interest in low-carbon energy. Yet this steep rise in distributed, uncontrolled solar PV capacity is being met with growing concern in maintaining electric grid stability when solar PV reaches higher penetration levels. Rapid reductions in solar PV output create an immediate and direct rise in the net system load. Demand response and storage technologies can offset these fluctuations in the net system load, but their potential has yet to be realized through wide-scale commercial dissemination. In the interim these fluctuations will continue to cause technical and economic challenges to the utility and the end-user. Late-afternoon peak demands are of particular concern as solar PV drops off and household demand rises as residents return home. Transient environmental factors such as clouding, rain, and dust storms pose additional uncertainties and challenges. This study analyzes such complex cases by simulating residential loads, rooftop solar PV output, and dust storm effects on solar PV output to examine transients in the net system load. The Phoenix, Arizona metropolitan area is used as a case study that experiences dust storms several times per year. A dust storm is simulated progressing over the Phoenix metro in various directions and intensities. Various solar PV penetration rates are also simulated to allow insight into resulting net loads as PV penetration grows in future years.
Development of Biomass Energy Technologies and Business Models for Southern Africa
Authors: Agyemang Malena , Johnson Nathan G.
Published: January 2016

This study evaluates options for biomass pellet formulations and business models to create a sustainable energy solution for cooking energy in Southern Africa. Various agricultural wastes and agro-processing wastes are investigated to meet industry standards on biomass pellet quality. These fuels are obtained from farms and facilities across a geographic area that affects the end-cost of the pellet through transportation costs and the cost of the biomass. The technical performance of the pellet and cost of the pellet are first contrasted and then optimized in unison to develop sustainable energy options that can provide year-round clean energy for household cooking and heating needs. A market was analyzed using wheat, sugarcane and maize crops as components for the biomass pellet fuel source in the Zululand district of South Africa. Using a target moisture content (MCtarget) of 8–10%, a target lower heating value (LHVtarget) greater than 16.0 MJ/kg and a target percent ash (Ashtarget) less than 3%, pellet metrics were optimized. The cost of the crops for the pellets was dependent upon the amount of each biomass used to make up the composition of the pellet. The production demand was then analyzed based on the most current consumer cooking fuel demand within South Africa. The production model was evaluated for three factory sizes; small (1hr/ton), medium (3hr/ton), and large (5hr/ton). Primary shipping cost is based on factory location and has a major impact on the cost of the pellet for the consumer as well as the availability of the supply. Factory location was analyzed by varying the biomass crop distance to the factory. Several business models are evaluated within this study to show which representation results in a high quality pellet of low cost to consumer. The study suggests the pellet be composed of 44.62% sugarcane, 47.49% maize, and 0.82% wheat resulting in a LHV of 16.00 MJ/kg, a MC of 8 (w/w%), and an ash content of 3 (w/w%). The optimal cost of the biomass fuel pellet for the consumer ranged from 172.77US$/ton to 185.03 US$/ton.
Multi-Level Optimization Method for Vehicle Body in Conceptual Design
Authors: Hou Wenbin , Shan Chunlai , Zhang Hongzhe
Published: January 2016

Since product development lead-time needs to be as short as possible in contemporary enterprises, it is necessary to assess and optimize the performance of the structure in conceptual design phase for avoiding the time consuming production of trial models for vehicle body. This paper proposes a conceptual design tool based on optimization algorithms for global body frames named Vehicle Concept Design-Intelligent CAE system (VCD-ICAE). A multilevel optimization algorithm is applied to optimize the body performance, decide the size parameters, and generate cross-sectional shapes that satisfy design engineers’ required characteristics. The global body stiffness and vibration property would be optimized while decreasing the mass of body. The paper describes the implementation of the optimal algorithm, and Genetic algorithms are applied to solve the optimization problem. A case of optimization for a real car is given to verify the validity of the algorithm.
Kinematic Analysis of a 3-PSP Spatial Motion Platform
Authors: Baron Luc
Published: January 2016

This paper presents the kinematic analysis of a 3-PSP motion seat to be used as a flight simulator. To ensure the pilot’s security, all passive joints are kept on the base plate rather than under the moving platform, and thus, use an upside-down configuration relative to previously published results in the literature. Although the resulting kinematic is more complex, it can still be solved in an analytical form, even when a non-symmetric base and moving platforms are used.
Flow and Heat Transfer Characteristics in a Gas Turbine Can Combustor
Authors: Mohammed Saad A. , Khalil Essam E. , Kayed Hatem
Published: January 2016

This paper presents a numerical computations are performed to investigate the convective heat transfer characteristics of a gas turbine can combustor under cold flow conditions in a Reynolds number range between 50,000 and 600,000 with a characteristic swirl number of 0.7. The RNG (K-ε Model) predictions are compared with the experimental data of local heat transfer distribution on the combustor liner wall. It was observed that the flow field in the combustor is characterized by an expanding swirling flow, which impinges on the liner wall close to the inlet of the combustor. The impinging shear layer is responsible for the peak location of heat transfer augmentation. It is observed that as Reynolds number increases, the peak heat transfer augmentation ratio (compared with fully developed pipe flow) reduces from 10.5 to 2.7. Additionally, the peak location does not change with Reynolds number since the flow structure in the combustor is also a function of the swirl number. The heat transfer coefficient distribution on the liner wall predicted from the RNG (K-ε Model) is in good agreement with experimental values. The location and the magnitude of the peak heat transfer are predicted in very close agreement with the experiments.
Laser Micromachining of Thin Beams for Silicon MEMS: Optimization of Cutting Parameters Using the Taguchi Method
Authors: Pusch Tim P. , D’Auria Mario , Tolou Nima , Holmes Andrew S.
Published: January 2016

While thin beams are widely used structural elements in Micro-Electro-Mechanical-Systems (MEMS) there are very few studies investigating the laser machining of clean high aspect ratio silicon beams. This work presents a systematic study of selected influencing cutting parameters with the goal of machining high aspect ratio beams with low side wall surface roughness (Ra) and high cross section verticality, i.e. low taper angle. The Taguchi method was used to find the optimal setting for each of the selected parameters (pulse frequency, laser diode current, pulse overlap, number of patterns to be marked, gap size between patterns) utilizing orthogonal arrays and signal-to-noise (S/N) ratio analysis. Double-sided clamped beams of 100μm width and 10mm length were machined in silicon wafers of 525μm thickness using a nanosecond solid-state UV laser system (355nm wavelength). Our experimental results show that beams with an aspect ratio as high as 17.5 can be manufactured. Furthermore, a surface roughness of Ra = 0.37μm and taper angle of α = 2.52 degrees can be achieved. This will make the fast fabrication of MEMS devices with aspect ratios as high as those from deep reactive ion etching possible.
Technical Note: Confirming the prescribed angle of CT localizer radiographs and c‐arm projection acquisitions
Authors: Szczykutowicz Timothy P. , Labby Zacariah E. , Rubert Nicholas , Wallace Charles
Published: January 2016

Purpose:

Accurate CT radiograph angle is not usually important in diagnostic CT. However, there are applications in radiation oncology and interventional radiology in which the orientation of the x‐ray source and detector with respect to the patient is clinically important. The authors present a method for measuring the accuracy of the tube/detector assembly with respect to the prescribed tube/detector position for CT localizer, fluoroscopic, and general radiograph imaging using diagnostic, mobile, and c‐arm based CT systems.

Methods:

A mathematical expression relating the x‐ray projection of two metal BBs is related to gantry angle. Measurement of the BBs at a prescribed gantry (i.e., c‐arm) angle can be obtained and using this relation the prescribed versus actual gantry angle compared. No special service mode or proprietary information is required, only access to projection images is required. Projection images are available in CT via CT localizer radiographs and in the interventional setting via fluorography.

Results:

The technique was demonstrated on two systems, a mobile CT scanner and a diagnostic CT scanner. The results confirmed a known issue with the mobile scanner and accurately described the CT localizer angle of the diagnostic system tested.

Conclusions:

This method can be used to quantify gantry angle, which is important when projection images are used for procedure guidance, such as in brachytherapy and interventional radiology applications.
Stem cells lead the blind
Authors: Dalkara Deniz
Published: January 2016

Embryonic stem cell–derived retinas integrate and establish connections with remaining cells of degenerated monkey retinas.
FGF21: How sweet it is!
Authors: Lalazar Gadi
Published: January 2016

The liver hormone fibroblast growth factor 21 suppresses sweet and alcohol preferences.
Virulence and Resistance to Antifungal Therapies of Scopulariopsis Species
Authors: Paredes Katihuska , Capilla Javier , Mayayo Emilio , Guarro Josep
Published: January 2016

Scopulariopsis
is an emerging opportunistic fungus characterized by its high resistance to antifungal therapies. We have developed a murine model of disseminated infection in immunosuppressed animals by intravenous inoculation of
Scopulariopsis brevicaulis
and
Scopulariopsis brumptii
, the most clinically relevant species, in order to evaluate their virulence and their responses to conventional antifungal treatments. Survival and tissue burden studies showed that
S. brumptii
was more virulent than
S. brevicaulis
. The three drugs tested, liposomal amphotericin B, posaconazole, and voriconazole, prolonged the survival of mice infected with
S. brumptii
, but none showed efficacy against
S. brevicaulis
. The different therapies were only able to modestly reduce the fungal burden of infected tissue; however, in general, despite the high serum levels reached, they showed poor efficacy in the treatment of the infection. Unfortunately, the most effective therapy for
Scopulariopsis
infections remains unresolved.
Validation and Clinical Evaluation of a Novel Method To Measure Miltefosine in Leishmaniasis Patients Using Dried Blood Spot Sample Collection
Authors: Kip A. E. , Rosing H. , Hillebrand M. J. X. , Blesson S. , Mengesha B. , Diro E. , Hailu A. , Schellens J. H. M. , Beijnen J. H. , Dorlo T. P. C.
Published: January 2016

To facilitate future pharmacokinetic studies of combination treatments against leishmaniasis in remote regions in which the disease is endemic, a simple cheap sampling method is required for miltefosine quantification. The aims of this study were to validate a liquid chromatography-tandem mass spectrometry method to quantify miltefosine in dried blood spot (DBS) samples and to validate its use with Ethiopian patients with visceral leishmaniasis (VL). Since hematocrit (Ht) levels are typically severely decreased in VL patients, returning to normal during treatment, the method was evaluated over a range of clinically relevant Ht values. Miltefosine was extracted from DBS samples using a simple method of pretreatment with methanol, resulting in >97% recovery. The method was validated over a calibration range of 10 to 2,000 ng/ml, and accuracy and precision were within ±11.2% and ≤7.0% (≤19.1% at the lower limit of quantification), respectively. The method was accurate and precise for blood spot volumes between 10 and 30 μl and for Ht levels of 20 to 35%, although a linear effect of Ht levels on miltefosine quantification was observed in the bioanalytical validation. DBS samples were stable for at least 162 days at 37°C. Clinical validation of the method using paired DBS and plasma samples from 16 VL patients showed a median observed DBS/plasma miltefosine concentration ratio of 0.99, with good correlation (Pearson's
r
= 0.946). Correcting for patient-specific Ht levels did not further improve the concordance between the sampling methods. This successfully validated method to quantify miltefosine in DBS samples was demonstrated to be a valid and practical alternative to venous blood sampling that can be applied in future miltefosine pharmacokinetic studies with leishmaniasis patients, without Ht correction.
Genome-Resolved Metagenomic Analysis Reveals Roles for Candidate Phyla and Other Microbial Community Members in Biogeochemical Transformations in Oil Reservoirs
Authors: Hu Ping , Tom Lauren , Singh Andrea , Thomas Brian C. , Baker Brett J. , Piceno Yvette M. , Andersen Gary L. , Banfield Jillian F.
Published: January 2016

Oil reservoirs are major sites of methane production and carbon turnover, processes with significant impacts on energy resources and global biogeochemical cycles. We applied a cultivation-independent genomic approach to define microbial community membership and predict roles for specific organisms in biogeochemical transformations in Alaska North Slope oil fields. Produced water samples were collected from six locations between 1,128 m (24 to 27°C) and 2,743 m (80 to 83°C) below the surface. Microbial community complexity decreased with increasing temperature, and the potential to degrade hydrocarbon compounds was most prevalent in the lower-temperature reservoirs. Sulfate availability, rather than sulfate reduction potential, seems to be the limiting factor for sulfide production in some of the reservoirs under investigation. Most microorganisms in the intermediate- and higher-temperature samples were related to previously studied methanogenic and nonmethanogenic archaea and thermophilic bacteria, but one candidate phylum bacterium, a member of the
Acetothermia
(OP1), was present in Kuparuk sample K3. The greatest numbers of candidate phyla were recovered from the mesothermic reservoir samples SB1 and SB2. We reconstructed a nearly complete genome for an organism from the candidate phylum
Parcubacteria
(OD1) that was abundant in sample SB1. Consistent with prior findings for members of this lineage, the OD1 genome is small, and metabolic predictions support an obligately anaerobic, fermentation-based lifestyle. At moderate abundance in samples SB1 and SB2 were members of bacteria from other candidate phyla, including
Microgenomates
(OP11),
Atribacteria
(OP9), candidate phyla TA06 and WS6, and
Marinimicrobia
(SAR406). The results presented here elucidate potential roles of organisms in oil reservoir biological processes.

IMPORTANCE
The activities of microorganisms in oil reservoirs impact petroleum resource quality and the global carbon cycle. We show that bacteria belonging to candidate phyla are present in some oil reservoirs and provide the first insights into their potential roles in biogeochemical processes based on several nearly complete genomes.
Age Dependence and Isotype Specificity of Influenza Virus Hemagglutinin Stalk-Reactive Antibodies in Humans
Authors: Nachbagauer Raffael , Choi Angela , Izikson Ruvim , Cox Manon M. , Palese Peter , Krammer Florian
Published: January 2016

Influenza remains a major global health burden. Seasonal vaccines offer protection but can be rendered less effective when the virus undergoes extensive antigenic drift. Antibodies that target the highly conserved hemagglutinin stalk can protect against drifted viruses, and vaccine constructs designed to induce such antibodies form the basis for a universal influenza virus vaccine approach. In this study, we analyzed baseline and postvaccination serum samples of children (6 to 59 months), adults (18 to 49 years), and elderly individuals (≥65 years) who participated in clinical trials with a recombinant hemagglutinin-based vaccine. We found that baseline IgG and IgA antibodies against the H1 stalk domain correlated with the ages of patients. Children generally had very low baseline titers and did not respond well to the vaccine in terms of making stalk-specific antibodies. Adults showed the highest induction of stalk-specific antibodies, but the elderly had the highest absolute antibody titers against the stalk. Importantly, the stalk antibodies measured by enzyme-linked immunosorbent assay (ELISA) showed neutralizing activity in neutralization assays and protected mice in a passive-transfer model in a stalk titer-dependent manner. Finally, we found similar patterns of stalk-specific antibodies directed against the H3 and influenza B virus hemagglutinins, albeit at lower levels than those measured against the H1 stalk. The relatively high levels of stalk-specific antibodies in the elderly patients may explain the previously reported low influenza virus infection rates in this age group. (This study has been registered at ClinicalTrials.gov under registration no. NCT00336453, NCT00539981, and NCT00395174.)

IMPORTANCE
The present study provides evidence that titers of broadly neutralizing hemagglutinin stalk-reactive antibodies increase with age, possibly due to repeated exposure to divergent influenza viruses. These relatively high levels of antistalk titers may be responsible for lower circulation rates of influenza viruses in older individuals. Our findings suggest that the level of antistalk antibodies is a good surrogate marker for protection against influenza virus infection. In addition, the levels of antistalk antibodies might determine the breadth of protection against different drifted strains.
Asthma medication prescribing before, during and after pregnancy: a study in seven European regions
Authors: Charlton Rachel A , Pierini Anna , Klungsøyr Kari , Neville Amanda J , Jordan Susan , de Jong-van den Berg Lolkje T W , Thayer Daniel , Bos H Jens , Puccini Aurora , Hansen Anne V , Gini Rosa , Engeland Anders , Nybo Andersen Anne-Marie , Dolk Helen , Garne Ester
Published: January 2016

Objectives

To explore utilisation patterns of asthma medication before, during and after pregnancy as recorded in seven European population-based databases.

Design

A descriptive drug utilisation study.

Setting

7 electronic healthcare databases in Denmark, Norway, the Netherlands, Italy (Emilia Romagna and Tuscany), Wales, and the Clinical Practice Research Datalink representing the rest of the UK.

Participants

All women with a pregnancy ending in a delivery that started and ended between 2004 and 2010, who had been present in the database for the year before, throughout and the year following pregnancy.

Main outcome measures

The percentage of deliveries where the woman received an asthma medicine prescription, based on prescriptions issued (UK) or dispensed (non-UK), during the year before, throughout or during the year following pregnancy. Asthma medicine prescribing patterns were described for 3-month time periods and the choice of asthma medicine and changes in prescribing over the study period were evaluated in each database.

Results

In total, 1 165 435 deliveries were identified. The prevalence of asthma medication prescribing during pregnancy was highest in the UK and Wales databases (9.4% (CI959.3% to 9.6%) and 9.4% (CI959.1% to 9.6%), respectively) and lowest in the Norwegian database (3.7% (CI953.7% to 3.8%)). In the year before pregnancy, the prevalence of asthma medication prescribing remained constant in all regions. Prescribing levels peaked during the second trimester of pregnancy and were at their lowest during the 3-month period following delivery. A decline was observed, in all regions except the UK, in the prescribing of long-acting β-2-agonists during pregnancy. During the 7-year study period, there were only small changes in prescribing patterns.

Conclusions

Differences were found in the prevalence of prescribing of asthma medications during and surrounding pregnancy in Europe. Inhaled β-2 agonists and inhaled corticosteroids were, however, the most popular therapeutic regimens in all databases.
Prevalence of depression and anxiety in top-level male and female football players
Authors: Junge Astrid , Feddermann-Demont Nina
Published: January 2016

Background

Scientific studies on the prevalence of mental health problems in elite athletes are rare, and most have had considerable methodological limitations, such as low response rate and heterogeneous samples.

Aims

To evaluate the prevalence of depression and anxiety in top-level football players in comparison to the general population, and to analyse potential risk factors.

Methods

Players of all first league (FL) and of four U-21 football teams in Switzerland were asked to answer a questionnaire on player's characteristics, the Centre of Epidemiologic Studies Depression Scale (CES-D) and the Generalized Anxiety Disorder (GAD-7) scale.

Results

All 10 women's FL teams, 9 of 10 men's FL teams and 4 male U-21 teams (n=471 football players) took part in the study. The CES-D score indicated a mild to moderate depression in 33 (7.6%) players and a major depression in 13 (3.0%) players. The GAD-7 score indicated an at least moderate anxiety disorder in 6 (1.4%) players. Compared to the general population, the prevalence of depression was similar and the prevalence of anxiety disorders was significantly (χ2=16.7; p<0.001) lower in football players. Significant differences were observed with regard to player characteristics, such as age, gender, player position, level of play and current injury.

Conclusions

Swiss FL football players had the same prevalence of depression as the general population, while male U-21 players had a higher prevalence of depression. It is important to raise awareness and knowledge of athletes’ mental health problems in coaches and team physicians, and to provide adequate treatment to athletes.
Risk factors for osteoporosis and fragility fractures in patients with systemic lupus erythematosus
Authors: Carli L , Tani C , Spera V , Vagelli R , Vagnani S , Mazzantini M , Di Munno O , Mosca M
Published: January 2016

Osteoporosis (OP) and fragility fractures (FFx) are a known comorbidity in patients with systemic lupus erythematosus (SLE). This work aimed at evaluating (1) the prevalence of OP and FFx in a cohort of SLE and (2) the risk factors associated with both OP and FFx. The following data were collected from clinical charts: age, sex, menopausal status (MP), body mass index, smoking habits, disease duration, daily dose and cumulative glucocorticoids (GCs), type of organ involvement, comorbidities and medications. Data on bone metabolism, calcium and vitamin D supplementation and treatment with bisphosphonates, teriparatide or denosumab were collected, together with bone mineral density (BMD) values (measured by dual-energy X-ray absorptiometry (DXA)) and history of FFx (occurred after the onset of SLE and unrelated to trauma). OP and reduced BMD were defined according to the WHO. 186 patients were included (women 175, men 11; mean age 46.4±13 years, mean disease duration 14.9±9 years). At their last visit, 97 patients (52.2%) had a reduced BMD and 52 (27.9%) had OP. 22 patients (11.8%), all women, had at least one FFx; six patients (27.3%) were pre-menopausal. On univariate analysis, age, cumulative dose of GC, MP, therapy with antiepileptics and chronic renal failure (CRF) were correlated with OP (p<0.03); age, total amount of GC, MP, CRF, anticoagulants (AC) and antiepileptic therapy were correlated with FFx (p<0.05). The multivariate logistic model confirmed a direct association of OP and age, MP and antiepileptic therapy (p≤0.01) and of FFx and age, chronic therapy with AC and antiepileptics (p<0.03). In conclusion, low BMD is frequently observed in SLE, and FFx are observed also in premenopausal patients. Together with traditional risk factors (age, MP and GC), CRF and chronic treatments with AC or antiepileptics seem to be associated with a higher risk profile for OP and FFx occurrence.
A novel reconstruction tool (syngo DynaCT Head Clear) in the post-processing of DynaCT images to reduce artefacts and improve image quality
Authors: Lescher Stephanie , Reh Christina , Hoelter Maya Christina , Czeppan Katja , Porto Luciana , Blasel Stella , Berkefeld Joachim , Wagner Marlies
Published: January 2016

Background

Latest generations of flat detector (FD) neuroangiography systems are able to obtain CT-like images of the brain parenchyma. Owing to the geometry of the C-arm system, cone beam artifacts are common and reduce image quality, especially at the periphery of the field of view. An advanced reconstruction algorithm (syngo DynaCT Head Clear) tackles these artifacts by using a modified interpolation-based 3D correction algorithm to improve image quality.

Materials and methods

Eleven volumetric datasets from FD-CT scans were reconstructed with the standard algorithm as well as with the advanced algorithm. In a two-step data analysis process, two reviewers compared dedicated regions of the skull and brain in both reconstruction modes using a 5-point scale (1, much better; 5, much worse; advanced vs standard algorithm). Both reviewers were blinded to the reconstruction mode. In a second step, two additional observers independently evaluated image quality of the 3D data (non-comparative evaluation) in dedicated regions also using a 5-point scale (1, not diagnostically evaluable; 5, good quality, perfectly usable for diagnosis) for both reconstruction algorithms.

Results

Both in the comparative evaluation of dedicated brain regions and in the independent analysis of the FD-CT datasets the observers rated a better image quality if the advanced algorithm was used. The improvement in image quality was statistically significant at both the supraganglionic (p=0.018) and the infratentorial (p=0.002) levels.

Conclusions

The advanced reconstruction algorithm reduces typical artifacts in FD-CT images and improves image quality at the periphery of the field of view.
Dose‐dependent antinociceptive and sedative effects of epidural romifidine in cattle
Authors: Marzok M. A. , El‐khodery S. A.
Published: January 2016

The objective of this study was to evaluate the antinociceptive and sedative effects of epidural administration of romifidine in dairy cattle. Twenty‐four dairy cows, divided randomly into four groups (three experimental and one control; n=6) received one of three doses of romifidine (30, 40 or 50 μg/kg) diluted in sterile saline (0.9 per cent) to a final volume of 25 ml or an equivalent volume of sterile saline. Antinociception and its anatomical extent was assessed by applying a standard stimulus (needle pin pricks) in different areas and by applying an electrical stimulus to the flank. The antinociceptive effect of romifidine was produced not only in the tail, anus, perineum, vulva and inguinal area but extended up to the coronary band of the hindlimbs and chest areas. Epidural romifidine induced mild‐to‐moderate sedation at 30 and 40 μg/kg doses and deep sedation at the 50 μg/kg dose. The antinociceptive and sedative effect was dose‐dependent in terms of intensity and duration. Thus, epidural administration of romifidine was effective in providing antinociception and sedation in cattle, and can be used in standing flank and udder surgery in cattle.
QED and surface plasmons on graphene
Authors: Bordag M. , Pirozhenko I. G.
Published: January 2016

We consider the quantum field theory approach to graphene. The model consists of the photon field in the bulk, i.e., in (3+1) dimensions, and a spinor field on a brane, i.e., in (2+1) dimensions. Integrating out the spinor field, an effective action appears, from which one has modified Maxwell equations accounting for the response of graphene. Within this model, one has the known one-loop polarization tensor allowing to investigate specific questions. Here, we consider the surface plasmons which may travel along graphene, with finite chemical potential or finite temperature.
Casimir entropy for ferromagnetic materials
Authors: Korikov C. C.
Published: January 2016

We describe recent results concerning the compatibility of the Lifshitz theory of dispersion forces with thermodynamics. It is shown that for ferromagnetic metals described by the plasma model and for ferromagnetic dielectrics with omitted dc conductivity the Lifshitz theory satisfies the Nernst heat theorem. At the same time, for magnetic metals described by the Drude model and for ferromagnetic dielectrics with account of dc conductivity the Nernst heat theorem is violated.
Magic numbers and persistent current oscillations in electron–hole quantum dots
Authors: Vasilchenko Aleksandr A. , Tolkachev Demid M.
Published: January 2016

The system of Kohn–Sham equations is solved self-consistently for the two-dimensional, spatially separated electrons and holes. We find the series of magic numbers for the total angular momentum of the electrons and holes in a strong magnetic field. The change of the angular momentum of the charge carriers is shown to lead to the persistent current oscillations.
Bekenstein–Hawking entropy by energy quantization from Reissner–Nordström black hole
Authors: Hossain M. Jakir , Rahman M. Atiqur , Hossain M. Ilias
Published: January 2016

We consider the motion of a test particle orbiting around Reissner–Nordström (RN) black hole spacetime. The complete set of equations for radial motion and effective potential is derived. We also derive the radius of the different stable circular orbits of this particle corresponding to different label indexes like the Bohr atomic model. We also quantized the energy of this particle from the quantization of angular momentum and calculated the Bekenstein–Hawking entropy of RN black hole. We also investigate the change of entropy between two nearby states approaches to zero for large quantum numbers.
Quantum smearing in hybrid inflation with chaotic potentials
Authors: Ahmed Waqas , Ishaque Ommair , Rehman Mansoor Ur
Published: January 2016

We study the impact of 1-loop radiative corrections in a nonsupersymmetric model of hybrid inflation (HI) with chaotic (polynomial-like) potential, [Formula: see text]. These corrections can arise from the possible couplings of inflaton with other fields which can play an active role in the reheating process. The tree-level predictions of these models are shown to lie outside of the Planck’s latest bounds on the scalar spectral index [Formula: see text] and the tensor to scalar ratio [Formula: see text]. However, the radiatively corrected version of these models, [Formula: see text], is fully consistent with the Planck’s data. More specifically, fermionic radiative correction ([Formula: see text]) reduces the tensor to scalar ratio significantly and a red-tilted spectral index [Formula: see text], consistent with Planck’s data, is obtained even for sub-Planckian field-values.
Generalized second law of thermodynamics on the apparent horizon in modified Gauss–Bonnet gravity
Authors: Abdolmaleki A. , Najafi T.
Published: January 2016

Modified gravity (MG) and generalized second law (GSL) of thermodynamics are interesting topics in the modern cosmology. In this regard, we investigate the GSL of gravitational thermodynamics in the framework of modified Gauss–Bonnet (GB) gravity or [Formula: see text]-gravity. We consider a spatially FRW universe filled with the pressureless matter and radiation enclosed by the dynamical apparent horizon with the Hawking temperature. For two viable [Formula: see text] models, we first numerically solve the set of differential equations governing the dynamics of [Formula: see text]-gravity. Then, we obtain the evolutions of the Hubble parameter, the GB curvature invariant term, the density and equation of state (EoS) parameters as well as the deceleration parameter. In addition, we check the energy conditions for both models and finally examine the validity of the GSL. For the selected [Formula: see text] models, we conclude that both models have a stable de Sitter attractor. The EoS parameters behave quite similar to those of the [Formula: see text]CDM model in the radiation/matter dominated epochs, then they enter the phantom region before reaching the de Sitter attractor with [Formula: see text]. The deceleration parameter starts from the radiation/matter dominated eras, then transits from a cosmic deceleration to acceleration and finally approaches a de Sitter regime at late times, as expected. Furthermore, the GSL is respected for both models during the standard radiation/matter dominated epochs. Thereafter when the universe becomes accelerating, the GSL is violated in some ranges of scale factor. At late times, the evolution of the GSL predicts an adiabatic behavior for the accelerated expansion of the universe.
A FRACTAL PERMEABILITY MODEL FOR SHALE MATRIX WITH MULTI-SCALE POROUS STRUCTURE
Authors: SHENG MAO , LI GENSHENG , TIAN SHOUCENG , HUANG ZHONGWEI , CHEN LIQIANG
Published: January 2016

Nanopore structure and its multiscale feature significantly affect the shale-gas permeability. This paper employs fractal theory to build a shale-gas permeability model, particularly considering the effects of multiscale flow within a multiscale pore space. Contrary to previous studies which assume a bundle of capillary tubes with equal size, in this research, this model reflects various flow regimes that occur in multiscale pores and takes the measured pore-size distribution into account. The flow regime within different scales is individually determined by the Knudsen number. The gas permeability is an integral value of individual permeabilities contributed from pores of different scales. Through comparing the results of five shale samples, it is confirmed that the gas permeability varies with the pore-size distribution of the samples, even though their intrinsic permeabilities are the same. Due to consideration of multiscale flow, the change of gas permeability with pore pressure becomes more complex. Consequently, it is necessary to cover the effects of multiscale flow while determining shale-gas permeability.
Broadband fractional total internal reflection quasi phase matching based second harmonic generation in reverse tapered isotropic semiconductor considering the effect of nonlinear reflection
Authors: Barma Minakshi Deb , Deb Sumita , Saha Ardhendu
Published: January 2016

This paper analyzes a highly efficient broadband second-harmonic generator in the mid infrared region using an isotropic reverse tapered semiconductor slab configuration, using fractional total internal reflection quasi-phase matching technique. A computer aided simulation has been performed using ZnTe as the nonlinear material which provides an extremely high conversion efficiency of 22.94% with a 3[Formula: see text]dB bandwidth of 200[Formula: see text]nm. Effect of varying the slab dimensions on the performance parameters has also been analyzed. Finally, the catastrophic effect caused by destructive interference due to nonlinear law of reflection has also been incorporated in the analysis thereby giving more accurate results.
Linear and nonlinear optical response in 3-nitroaniline: A DFT study for comparison between molecular and bulk phases
Authors: Dadsetani M. , Omidi A. R.
Published: January 2016

We have studied the electronic structure and optical responses of both molecular and bulk phases of 3-nitroaniline (m-NA) using density functional theory (DFT). We have developed our calculations within the framework of band structure theory for both phases. The results of current simulation are also useful for comparison between solids and vapors. Findings show that the crystalline m-NA has an indirect bandgap which is smaller than its molecular counterpart. Due to the weak intermolecular interactions, the crystalline band structure shows very low dispersions and hence the crystalline spectra are very similar to those of molecules, especially at lower energies. This resemblance is extended to lower wavelengths in linear regime, but limited to higher wavelengths in nonlinear one. This study shows that the substituent groups play major roles in the band structure and charge transfer excitations. The optical spectra show higher intensity and more splitting, especially in nonlinear regime, when we go from molecular phase to bulk phase. Findings show that the electron energy loss structures in vapor phase are very close to [Formula: see text], hence energy loss spectroscopy is a direct way for measuring dielectric function of vapors. According to our results, the crystalline phase exhibits plasmon resonances at much higher energies compared to those of vapor phase. For example, the energy loss spectrum of m-NA molecule shows plasmon peak around 17[Formula: see text]eV which is about 10[Formula: see text]eV lower than the crystalline counterpart. The comparison between nonlinear spectra and the linear spectra (as functions of both [Formula: see text] and 2[Formula: see text]) reveals the significant resemblance between linear and nonlinear structures in both phases. This study shows that the molecular-based models for investigating optical properties of organic crystals are only suitable for low energy regions. Finally, our simulation reproduces the experimental results very well.
Exact solitons in a medium with competing weakly nonlocal nonlinearity and parabolic law nonlinearity
Authors: Younis Muhammad , Sardar Ali , Rizvi Syed Tahir Raza , Zhou Qin
Published: January 2016

This work studies the optical solitons in the physical model that describes the propagation of optical solitons in a medium with competing weakly nonlocal nonlinearity and parabolic law nonlinearity via the [Formula: see text]-expansion scheme, exact dark and singular one-soliton solutions, along with the constraint conditions, are reported.
A new proof of Bronshtein’s theorem
Authors: Parusiński Adam , Rainer Armin
Published: January 2016

We give a new self-contained proof of Bronshtein’s theorem, that any continuous root of a [Formula: see text]-family of monic hyperbolic polynomials of degree [Formula: see text] is locally Lipschitz continuous, and obtain explicit bounds for the Lipschitz constant of the root in terms of the coefficients. As a by-product, we re-prove the recent result of Colombini, Orrú, and Pernazza that a [Formula: see text]-curve of hyperbolic polynomials of degree [Formula: see text] admits a [Formula: see text]-system of its roots.
Global existence of small amplitude solutions to one-dimensional nonlinear Klein–Gordon systems with different masses
Authors: Kim Donghyun
Published: January 2016

We study the Cauchy problem for systems of cubic nonlinear Klein–Gordon equations with different masses in one space dimension. Under a suitable structural condition on the nonlinearity, we will show that the solution exists globally and decays of the rate [Formula: see text] in [Formula: see text], [Formula: see text] as [Formula: see text] tends to infinity even in the case of mass resonance, if the Cauchy data are sufficiently small, smooth and compactly supported.
A remark on the Glimm scheme for inhomogeneous hyperbolic systems of balance laws
Authors: Christoforou Cleopatra
Published: January 2016

General hyperbolic systems of balance laws with inhomogeneous flux and source are studied. Global existence of entropy weak solutions to the Cauchy problem is established for small BV data under appropriate assumptions on the decay of the flux and the source with respect to space and time. There is neither a hypothesis about equilibrium solution nor about the dependence of the source on the state vector as previous results have assumed.
No BV bounds for approximate solutions to p-system with general pressure law
Authors: Bressan Alberto , Chen Geng , Zhang Qingtian , Zhu Shengguo
Published: January 2016

For the [Formula: see text]-system with large BV initial data, an assumption introduced in [N. S. Bakhvalov, Ž. Vyčisl. Mat. i Mat. Fiz. (Russian) 10 (1970) 969–980] by Bakhvalov guarantees the global existence of entropy weak solutions with uniformly bounded total variation. The present paper provides a partial converse to this result. Whenever Bakhvalov’s condition does not hold, we show that there exist front tracking approximate solutions, with uniformly positive density, whose total variation becomes arbitrarily large. The construction extends the arguments in [A. Bressan, G. Chen and Q. Zhang, J. Diff. Eqs. 256(8) (2014) 3067–3085] to a general class of pressure laws.
Welfare Effects of Water Pricing in Germany
Authors: Müller Christopher
Published: January 2016

The observed two-part tariff price structure (consisting of a lump-sum price and linear marginal price) for drinking water in Germany does not reflect the cost structure reported in the literature. Recovering marginal costs from a sample of 251 German counties, we see that there are positive price-cost margins, while lump-sum prices are too low. A price structure readjustment along welfare economic principles (marginal cost pricing, lump-sum price ensures cost-recovery) would increase the mean consumer surplus by 0.037% of the local GDP or €[Formula: see text]2.129 million per county, assuming a share of 15% variable costs in total costs.