bluuebunny/crossref_metadata_2025_split huggingface dataset:
Parameter uncertainty and identifiability of a conceptual semi-distributed model to simulate hydrological processes in a small headwater catchment in Northwest China
Authors: Ouyang Shuai , Puhlmann Heike , Wang Shunli , von Wilpert Klaus , Sun Osbert Jianxin 
Published: June 2014

Abstract

Introduction
Conceptual hydrological models are useful tools to support catchment water management. However, the identifiability of parameters and structural uncertainties in conceptual rainfall-runoff modeling prove to be a difficult task. Here, we aim to evaluate the performance of a conceptual semi-distributed rainfall-runoff model, HBV-light, with emphasis on parameter identifiability, uncertainty, and model structural validity.

Results
The results of a regional sensitivity analysis (RSA) show that most of the model parameters are highly sensitive when runoff signatures or combinations of different objective functions are used. Results based on the generalized likelihood uncertainty estimation (GLUE) method further show that most of the model parameters are well constrained, showing higher parameter identifiability and lower model uncertainty when runoff signatures or combined objective functions are used. Finally, the dynamic identifiability analysis (DYNIA) shows different types of parameter behavior and reveals that model parameters have a higher identifiability in periods where they play a crucial role in representing the predicted runoff.

Conclusions
The HBV-light model is generally able to simulate the runoff in the Pailugou catchment with an acceptable accuracy. Model parameter sensitivity is largely dependent upon the objective function used for the model evaluation in the sensitivity analysis. More frequent runoff observations would substantially increase the knowledge on the rainfall-runoff transformation in the catchment and, specifically, improve the distinction of fast surface-near runoff and interflow components in their contribution to the total catchment runoff. Our results highlight the importance of identifying the periods when intensive monitoring is critical for deriving parameter values of reduced uncertainty.
Constraint induced movement therapy for stroke survivors in Jordon: a home-based model
Authors: Tariah Hashem Abu , Almalty Abdul-Majeed , Sbeih Ziad , Al-Oraibi Saleh 
Published: June 2014

Aims: This article describes a home-based study evaluating the effectiveness of modified constraint induced movement therapy (CIMT) in improving upper limb function in stroke survivors, and compares it with the clinical-based Neurodevelopmental Treatment (NDT) approach. Methods: In this pretest-post-test randomized study, 10 stroke survivors received home-based modified CIMT and eight stroke survivors received conventional NDT rehabilitation. The focus of the CIMT was on the hemiplegic hand, by which the less affected hand was restrained, with structured training for the more affected arm and hand. The intervention was executed two hours a day, seven days a week for two months, in the patients' normal day-care environment. Arm motor function outcomes were evaluated using the Wolf Motor Function Test as a primary outcome measure. The motor activity log, and the Fugl-Meyer Assessment were used as secondary outcome measures. Findings: Stroke survivors in the CIMT group showed a statistically significant improvement in all arm motor function outcomes. However, while numerically the improvement was better in the CIMT group, it failed to be significantly better than that seen in the NDT group. Conclusions: Home based CIMT conducted by caregivers with therapists' support is a promising approach for improving affected upper limb in stroke survivors. However, additional studies are needed to confirm these findings.
Community-based rehabilitation: why not in Iraq?
Authors: Hassin Ahmed 
Published: June 2014

Introduction: Community-based rehabilitation (CBR) has emerged and developed since the 1950s as a possible solution for socio-economic reintegration of people with disabilities. Government and non-government organizations are key players and have vital roles in policy making, planning, funding, managing and implementing CBR programmes. Contents: This article explores the role of government and non-government organizations and international agencies in community-based rehabilitation in Iraq. It examines the possibility of NGOs initiating and running (CBR) programmes for people with a disability regardless of Iraqi government commitment or participation. Conclusions: The research results show that implementation of CBR in Iraq is vital but not widely spread. Non-government organizations seem more active, committed and capable at the present time being to initiate, run and manage CBR programmes when compared with the government of Iraq.
Projective compactifications and Einstein metrics
Authors: Čap Andreas , Gover A. Rod 
Published: June 2014

Abstract
For complete affine manifolds we introduce a definition of
compactification based on the projective differential geometry
(i.e. geodesic path data) of the given connection. The definition
of projective compactness involves a real parameter α called
the order of projective compactness. For volume preserving
connections, this order is captured by a notion of volume
asymptotics that we define. These ideas apply to complete
pseudo-Riemannian spaces, via the Levi-Civita connection, and thus
provide a notion of compactification alternative to conformal
compactification. For many orders α, we provide an asymptotic
form of a metric which is sufficient for projective compactness of
the given order, thus also providing many local examples.
Distinguished classes of projectively compactified geometries of
orders one and two are associated with Ricci-flat connections and
non-Ricci-flat Einstein metrics, respectively. Conversely, these
geometric conditions are shown to force the indicated order of
projective compactness. These special compactifications are shown to
correspond to normal solutions of classes of natural linear PDE
(so-called first BGG equations), or equivalently holonomy reductions
of projective Cartan/tractor connections. This enables the
application of tools already available to reveal considerable
information about the geometry of the boundary at infinity. Finally,
we show that metrics admitting such special compactifications always
have an asymptotic form as mentioned above.
Sex differences in the fetal heart rate variability indices of twins
Authors: Tendais Iva , Figueiredo Bárbara , Gonçalves Hernâni , Bernardes João , Ayres-de-Campos Diogo , Montenegro Nuno 
Published: June 2014

Abstract

Aims: To evaluate the differences in linear and complex heart rate dynamics in twin pairs according to fetal sex combination [male-female (MF), male-male (MM), and female-female (FF)].

Methods: Fourteen twin pairs (6 MF, 3 MM, and 5 FF) were monitored between 31 and 36.4 weeks of gestation. Twenty-six fetal heart rate (FHR) recordings of both twins were simultaneously acquired and analyzed with a system for computerized analysis of cardiotocograms. Linear and nonlinear FHR indices were calculated.

Results: Overall, MM twins presented higher intrapair average in linear indices than the other pairs, whereas FF twins showed higher sympathetic-vagal balance. MF twins exhibited higher intrapair average in entropy indices and MM twins presented lower entropy values than FF twins considering the (automatically selected) threshold r
Lu. MM twin pairs showed higher intrapair differences in linear heart rate indices than MF and FF twins, whereas FF twins exhibited lower intrapair differences in entropy indices.

Conclusions: The results of this exploratory study suggest that twins have sex-specific differences in linear and nonlinear indices of FHR. MM twins expressed signs of a more active autonomic nervous system and MF twins showed the most active complexity control system. These results suggest that fetal sex combination should be taken into consideration when performing detailed evaluation of the FHR in twins.
An Exploration of Community Capital, Student Composition of Schools, and Achievement Gaps
Authors: Wang Chuang , Algozzine Bob , Porfeli Erik 
Published: June 2014

Abstract
“Closing the achievement gap” (i.e. reducing differences in performance across racial and ethnic groups) has been the rallying cry and holy grail for reform efforts in American education for some time. In addition to influences associated with school and teacher factors, researchers have now turned their attention to characteristics in family backgrounds that may create or correlate with variation in academic and social outcomes at school. Previous research suggests that community capital, with its financial, human, and social features, is associated with school performance. In the present study, we examined relationships between community capital, student composition of schools, and student academic achievement measured by state standardized tests. Strongest associations were evident for community capital and academic outcomes. We discuss our findings in the context of equal educational opportunity, cultural and linguistic diversity, and the dream of achievement representing what you do at school more than where to go to do it.
Accurate Bending Strength Analysis of the Asymmetric Gear using the Novel ES-PIM with Triangular Mesh
Authors: Wang S. , Liu G. R. , Zhang G. Y. , Chen L. 
Published: June 2014

This paper extends the edge-based smoothed point interpolation method (ES-PIM) to bending strength analysis of asymmetric gears with complex outlines. Five sets of asymmetric gears with pressure angles of 20°/20°, 25°/20°, 30°/20°, 35°/20° and 40°/20° were generated by a specially designed rack cutter. Four key factors, e.g. accuracy, convergence, the convergence rate and the computational efficiency of the present ES-PIM were checked in great detail on these five models, and the distributions of bending stresses at the fillet of the drive side were carefully investigated. The finite element method (FEM) was also used to calculate the abovementioned factors to stress the advantages of ES-PIM. The numerical results indicate that ES-PIM can provide more efficient and accurate solutions in the stress field than the FEM, and is very suitable for stress analysis of complicated asymmetric gears.
Process Capability Study of Rapid Casting Solution for Aluminium Alloys using Three Dimensional Printing
Authors: Singh R. 
Published: June 2014

In the present work, the best shell wall thickness of a mould cavity was investigated in a process capability study of a rapid casting solution for aluminium alloys using threedimensional printing (3DP). Starting from the identification of a component/benchmark, an aluminium-alloy casting prototype was produced with different shell wall thicknesses by three dimensional printing. The results of the study suggest that, at the best shell wall thickness (5 mm) for aluminium alloys, the rapid casting solution using a 3DP process lies within the ±3.999 sigma (σ) limit.
Effect of Sintering Profiles on the Properties and Ageing Resistance of Y-TZP Ceramic
Authors: S. Sivakumar  , S. Ramesh  , K.L. Chin  , C.Y. Tan  , W.D. Teng  
Published: June 2014

A commercially available Y-TZP ceramic powder was fabricated under four different sintering profiles in order to investigate the effects of conventional single-stage sintering (SSS) with dwell times of 1 min and 2 h, respectively, compared with two-stage sintering (TSS), on the physical and mechanical properties of Y-TZP. Sintering was performed up to 1400oC at a ramp rate of 10oC/min. It was revealed that samples sintered via TSS yielded better properties than the SSS samples sintered at 1400oC using a dwell time of 2 h. In the hydrothermal ageing test, TSS samples did not undergo low-temperature degradation via the tetragonal to monoclinic phase transformation. Nevertheless, it was found by XRD analysis that Y-TZP ceramics sintered by the SSS method using a short dwell time of 1 min were effective in maintaining tetragonal phase stability after 50 h of exposure to superheated steam conditions.
Enhancement of Natural Convection Heat Transfer from the Rectangular Fins by Circular Perforations
Authors: Wadhah Hussein Abdul Razzaq Al- Doori  
Published: June 2014

The importance of heat transfer by natural convection in enclosures can be found in many engineering applications, such as energy transfer in buildings, solar collectors, nuclear reactors and electronic packaging. An experimental study was conducted to investigate heat transfer by natural convection in a rectangular fin plate with circular perforations as heat sinks. The patterns of the perforations included 24 circular perforations (holes) for the first fin; the number of perforations increased by eight for each fin to 56 in the fifth fin. These perforations were distributed in 6-14 rows and four columns. Experiments were carried out in an experimental facility that was specifically designed and constructed for this purpose. It was observed that the temperature along the non-perforated fin dropped from 30 to 25°C, but the temperature drop for the perforated fins was from 30 to 23.7°C at low power (6 W). The drop in temperature between the fin base and the tip increased as the diameter of the perforations increased. The temperature drop at the highest power (220 W) was from 250 to 49°C for the nonperforated fin and from 250 to 36°C for the perforated fins. The heat transfer rate and the coefficient of heat transfer increased with an increased number of perforations.
Evolving Trends of Supplier Selection Criteria and Methods
Authors: S. Thiruchelvam  , J.E. Tookey  
Published: June 2014

The increasing importance of supply chain management (SCM) is forcing organisations to reconsider and improvise their purchasing-related matters. In lieu of that, the supplier selection process plays an important role in purchasing activity. The supplier selection process has undergone significant changes in the past forty years. These changes have been beneficial to both the purchasing clients and the suppliers. The supplier selection decision making process involves multiple criteria comprising both qualitative and quantitative aspects. Sometimes, there might be some contradictions between tangible and intangible criteria which may necessitate a trade-off between conflicting criteria. This paper provides an overall picture of research on supplier selection problems and supplier selection practices. Different selection criteria, emerging issues of supplier selection and the solutions for these problems are summarised. This review shows that the application of a structured decision making technique is important, especially under the complex conditions that include both qualitative and quantitative criteria.
Turbulent Film Condensation of Pure Vapors Flowing Normal to A Horizontal Condenser Tube - Constant Heat Flux at the Tube Wall
Authors: B. Vijaya Lakshmi  , T. Subrahmanyam  , V. Dharma Rao  , K.V. Sharma  
Published: June 2014

A mathematical model was developed for the study of external turbulent film condensation of pure vapours flowing downward and normal to the axis of the condenser tube with constant heat flux conditions maintained at the tube wall. The magnitude of interfacial shear was estimated for a given external flow condition of the vapour with the help of Colburn’s analogy. The average condensation heat transfer coefficients for different system conditions were evaluated. The present theory was compared with the available experimental and theoretical data in the literature and was found to be satisfactory.
Metal Matrix Composite Brake Rotor: Historical Development and Product Life Cycle Analysis
Authors: A.A. Adebisi  , M.A. Maleque  , M.M. Rahman  
Published: June 2014

Metal matrix composites (MMCs) have become attractive for engineering structural applications due to their excellent specific strength and are increasingly seen as an alternative to conventional materials, particularly in the automotive industry. In this study, a historical background on the development and application of metal matrix composites for automotive brake rotors is presented. The discussion also includes an analysis of the product life cycle with stir casting as a case study. The historical review analysis revealed that gradual development of material and processing techniques have led to lighter weight, lower cost and higher performance brake rotors as a result of a better understanding of the mechanics of metal matrix composites. It emerged from the study that the stir casting technique provides ease of operation, sustainability and, most significantly, very competitive costs without sacrificing quality relative to other techniques; as such, it is the most attractive manufacturing process in the industry. These findings can be used for future design and manufacture of an efficient and effective aluminium matrix composite brake rotor for automotive and other applications.
Effect of pH on Electroless Ni-P Coating of Conductive and Nonconductive Materials
Authors: M. Moniruzzaman  , Subrata Roy  
Published: June 2014

Electroless nickel-phosphorus (Ni-P) coating of carbon steel as well as a polypropylene substrate was conducted using sodium hypophosphite as a reducing agent in alkaline media. The influence of pH on coating appearances and the properties of the coatings for both steel and the polypropylene substrate were studied. A nickel-phosphorus coating of good appearance was obtained in the pH range between 5.5 and 12.5 on the carbon steel substrate and between 8.5 and 12 on the polypropylene substrate. The percentage of Ni content in the coating increased with increasing pH of the bath solution. A smooth, uniform microstructure was found in the coating deposited in relatively lower pH solutions compared to higher pH baths. The microhardness of the Ni-P coating decreased with an increasing percentage Ni content in the deposit.
Patch antennas utilizing semi-insulating SiC for monolithic integration of the antenna subsystem on a SiC chip
Authors: Karacolak Tutku , Thirumalai Rooban V. K. G. , Topsakal Erdem , Koshka Yaroslav 
Published: June 2014

ABSTRACTSemi-insulating (SI) silicon carbide (SiC) was evaluated as a candidate material for dielectric substrate for patch antennas suitable for monolithic antenna integration on a SiC semiconductor chip. Computer simulations of the return loss were conducted to design microstrip patch antennas operating at 10 GHz. The antennas were fabricated using SI 4H-SiC substrates, with Ti-Pt-Au stacks for ground planes and patches. A good agreement between the experimental results and simulation was obtained. The radiation performance of the designed SiC based patch antennas was as good as that normally achieved from antennas fabricated using conventional RF materials such as FR4 and Rogers. The antennas had the gain around 2 dBi at 10 GHz, which is consistent with the conventional antennas of a similar size.
Gas Flow Tightly Coupled to Elastoplastic Geomechanics for Tight- and Shale-Gas Reservoirs: Material Failure and Enhanced Permeability
Authors: Kim Jihoon , Moridis George J. 
Published: June 2014

Summary
We investigate coupled flow and geomechanics in gas production from extremely low-permeability reservoirs such as tight- and shale-gas reservoirs, using dynamic porosity and permeability during numerical simulation. In particular, we take the intrinsic permeability as a step function of the status of material failure, and the permeability is updated every timestep. We consider gas reservoirs with the vertical and horizontal primary fractures, using the single- and dynamic double-porosity (dual-continuum) models. We modify the multiple-porosity constitutive relations for modeling the double porous continua for flow and geomechanics. The numerical results indicate that the production of gas causes redistribution of the effective-stress fields, increasing the effective shear stress and resulting in plasticity. Shear failure occurs not only near the fracture tips but also away from the primary fractures, which indicates the generation of secondary fractures. These secondary fractures increase the permeability significantly, and change the flow pattern, which, in turn, causes a change in the distribution of geomechanical variables. From various numerical tests, we find that shear failure is enhanced by a large pressure drop at the production well, a high Biot's coefficient, and low frictional and dilation angles. Smaller spacing between the horizontal wells also contributes to faster secondary fracturing. When the dynamic double-porosity model is used, we observe a faster evolution of the enhanced-permeability areas than that obtained from the single-porosity model, mainly because of a higher permeability of the fractures in the double-porosity model. These complicated physics for stress-sensitive reservoirs cannot properly be captured by the uncoupled or flow-only simulation, and, thus, tightly coupled flow and geomechanical models are highly recommended to describe accurately the reservoir behavior during gas production in tight- and shale-gas reservoirs and to design production scenarios smartly.
Shale Gas Characterization and Property Determination by Digital Rock Physics
Authors: Almarzooq Anas , AlGhamdi Tariq , Koronfol Safouh , Dernaika Moustafa , Walls Joel 
Published: June 2014

Abstract
Unconventional shale reservoirs differ largely from conventional sandstone and carbonate reservoirs in their origin, geologic evolution and current occurrence. Shale is a wide variety of rocks that are composed of extremely fine-grained particles with very small porosity and permeability values in the order of few porosity units and nano-darcy range, respectively. Shale formations are very complex at the core scale, and exhibit large vertical variations in lithology and Total Organic Carbon (TOC) at a small scale that renders core characterization and sweet spot detection very challenging. Shale formations are also very complex at the nano-scale pore level where the pores have different porosity types that are detected within the kerogen volume. These complexities led to further research and development of advanced application of high resolution X-ray CT scanning on full diameter core sections to characterize shale mineralogy, porosity and rock facies so that accurate evaluation of the sweet spot locations could be made for further detailed petrophysical and petrographic studies.
In this work, argillaceous shale gas cores were imaged using high resolution dual energy X-ray CT scanning. This imaging technique produces continuous whole core scans at 0.5mm spacing and derives accurate bulk density and effective atomic number (Zeff) logs along the core intervals which were crucial in determining lithology, porosity, and rock facies. Additionally, integrated XRD data and energy dispersive spectrum (EDS) analysis were acquired to confirm the mineral framework composition of the core. Smaller core plugs and subsamples representing the main variations in the core were extracted for much higher resolution X-ray CT scanning and Scanning Electron Microscopy (SEM) analysis. Porosity was mainly found in organic matter and was determined from 2D and 3D SEM images by image segmentation process. Horizontal fluid flow was only possible through the organic matter and the simulations of 3D FIB-SEM volumes by solving Stokes equation using Lattice Boltzmann Method (LBM).
A clear trend was observed between porosity and permeability while correlating with identified facies in the core. Silica-rich facies gave higher Phie-K characteristics compared to the low clay-rich facies. This is mainly caused by pressure compaction effect in the soft clay-rich samples. High percentages of organic matter were not found to be good indication for high porosity or permeability in the clay-rich shale samples. The depositional facies was found to have great effect on the pore types, rock fabric and reservoir properties. The results and interpretations entailed in this study provide further insights and enhance our understanding of heterogeneity of the organic rich shale reservoir rock.