bluuebunny/crossref_metadata_2025 huggingface dataset:
Adaptive boundary control of the size-dependent behavior of Euler–Bernoulli micro-beams with unknown parameters and varying disturbance
Authors: Ali Nojoumian Mohammad , Vatankhah Ramin , Salarieh Hassan
Published: December 2015

In this paper, modeling and vibration control of a strain-gradient clamped-free Euler–Bernoulli micro-beam exposed to varying disturbance is studied. A strain-gradient model of the Euler–Bernoulli micro-beam is represented in this paper and consisted of one partial differential equation and six ordinary equations as governing motion equation and boundary conditions, respectively. A boundary controller is proposed to suppress the system’s vibration. The controller is derived based on the direct Lyapunov method. An adaptation law is devised to assure system’s stability under parametric uncertainties. With the proposed adaptive robust boundary control, uniform boundedness under environmental and input disturbances could be achieved. The state of the system is proven to converge to a small neighborhood of zero by appropriately choosing design parameters. Simulations are provided to illustrate the applicability and effectiveness of the proposed controller.
Correlation of surface roughness and recast layer thickness in electrical discharge machining
Authors: Yildiz Yakup , Sundaram Murali M , Rajurkar Kamlakar P , Altintas Ahmet
Published: December 2015

Electrical discharge machining (EDM) is an extensively used method in the machining of electrically conductive materials. Recast or white layer formation is undesirable, but inevitable, result of EDM and needs to be understood and accurately determined to efficiently perform post-treatment processes for removing the recast layer caused by EDM process. In this study, recast layer thickness and surface roughness data obtained from experimental study were analyzed and a correlation between these two parameters has been established. Image-processing technique has been used for obtaining of recast layer thickness data. It was observed that the correlation between recast layer thickness and surface roughness increases remarkably with the increase of working current and pulse time. The correlation obtained in this study has the potential to predict the recast layer thickness on spark-eroded surfaces from simple surface roughness values instead of using the prevailing time-consuming and tedious etching and polishing method. The possible approximation of the recast layer thickness using a thermal model is also discussed.
Numerical modeling of conjugate heat transfer of a rotary disk
Authors: Moghadam Mohsen Z
Published: December 2015

This paper deals with the problem of conjugate heat transfer of a rotary disk which is uniformly heated. Computational fluid dynamics simulations are performed for different ranges of rotational Reynolds number (20,000–50,000) and heat flux (100, 200, and 400 kW/m3) on this surface. Two numerical approaches including multiple reference frame and sliding mesh are employed to simulate the interaction between rotary and stationary domains. It is shown that both methods yield satisfactory results, and an excellent agreement with the results obtained from the correlation available in the literature is also found. Furthermore, the effects of involved parameters on average and local convective heat transfer are investigated. Results show that the temperature profiles on the disk surface remain rather unchanged for all ranges of those parameters under study here. It is also shown that local Nusselt number decreases more steeply for higher ratios of fluid conductivity to solid conductivity.
Trends in the control of NOx and SOx combustion emissions: Implications to the design of fluidised bed combustion operations
Authors: Downmore Musademba , Jambwa Simbi D , Kusaziwa Kuipa P
Published: December 2015

This paper attempts to review the implications of the sulphur oxides (SOx), nitrogen oxides (NOx) and nitrous oxide (N2O) emissions to the design of fluidised bed combustion (FBC) operations. The review focuses on how the knowledge of SOx and NOx emissions trends can be applied to influence the design of FBC operations. The effects of the emission trends of these noxious gases on the design operations for FBC such as temperature control, nozzle designs, sorbent selection design, air supply and control designs were reviewed. The implications of SOx, N2O and NOx emissions on the design of FBC systems rest primarily on the need to design the operational conditions of the system. The design for the precise location of the fuel feeding ports, secondary air feeding ports, limestone feeding ports and a prescribed size and quantity of sorbents to feed into the system was found to be crucial for reduction of these emissions. The emissions also have an impact on the design of the distributor plate of the system; reduction of the emissions necessitates good fluidisation and well-regulated temperature within the system. The review therefore concludes that there is a close nexus between the design and operation of FBC systems with NOx, N2O and SOx emissions.
Research on a probabilistic assessment criterion of casing deformation in an incomplete borehole in deep salt formation
Authors: Tong Hua , Guo Daqiang , Zhu Xiaohua
Published: December 2015

Drilling and completing wells through complex salt formation is technically challenging and costing. Field data demonstrates that well casings designed by traditional safety coefficient criterion occurring failure in deep salt formation though their safety factors are greater than 1. To reveal the failure mechanism, a probabilistic computational model coupled with salt formation, defective cement and worn casing is established and analyzed using Monte Carlo simulation method. On the basis of reliability theory, the results calculated by 5000 times simulations show that the traditional safety coefficient criterion has been unable to adapt to the safety assessment of well casings under salt creep conditions. To gain a sophisticated evaluation, a new assessment criterion is established and applied to assess the security of well casings under salt creep conditions. This study provides a new perspective for revealing the failure mechanism and solutions of evaluation on well casings under salt creep conditions, which may be an alternative method to study and predict the life of well casings in deep complicated formation.
Operational characteristics on cylindrical steam reformer thermally coupled with a combustor
Authors: Jo Taehyun , Han Junhee , Koo Bonchan , Lee Dohyung
Published: December 2015

The thermal performance of a natural-gas based cylindrical steam reformer coupled with a combustor is investigated for the practical usage of a prototype fuel cell under development (KETEP project). In this study, thermal characteristics of internal combustor are analyzed that includes the effect of flame pattern on local heat release and heat transfer mechanism from combustor to reforming zone. Overall performances are found to depend on various inlet conditions such as fuel distribution ratio and steam carbon ratio. These experiments could guide how to manage efficiently the reformer’s fuel calorie and achieve high hydrogen production along with high thermal efficiency.
Modeling of unsteady structure of sheet/cloud cavitation around a two-dimensional stationary hydrofoil
Authors: Hong Feng , Yuan Jianping , Zhou Banglun , Li Zhong
Published: December 2015

Compared to non-cavitating flow, cavitating flow is much complex owing to the numerical difficulties caused by cavity generation and collapse. In the present work, cavitating flow around a two-dimensional Clark-Y hydrofoil is studied numerically with particular emphasis on understanding the cavitation structures and the shedding dynamics. A cavitation model, coupled with the mixture multi-phase approach, and the modified shear stress transport k-ω turbulence model has been developed and implemented in this study to calculate the pressure, velocity, and vapor volume fraction of the hydrofoil. The cavitation model has been implemented in ANSYS FLUENT platform. The hydrofoil has a fixed angle of attack of α = 8° with a Reynolds number of Re = 7.5 × 105. Simulations have been carried out for various cavitation numbers ranging from non-cavitating flows to the cloud cavitation regime. In particular, we compared the lift and drag coefficients, the cavitation dynamics, and the time-averaged velocity with available experimental data. The comparisons between the numerical and experimental results show that the present numerical method is capable to predict the formation, breakup, shedding, and collapse of the sheet/cloud cavity. The periodical formation, shedding, and collapse of sheet/cloud cavity lead to substantial increase in turbulent velocity fluctuations in the cavitation regimes around the hydrofoil and in the wake flow.
A simulation-based method using artificial neural networks for solving the inverse kinematic problem of articulated robots
Authors: Soylak Mustafa , Oktay Tuğrul , Turkmen İlke
Published: December 2015

In our article, inverse kinematic problem of a plasma cutting robot with three degree of freedom is solved using artificial neural networks. Artificial neural network was trained using joint angle values according to cartesian coordinates ( x, y, z) of end point of a robotic arm. The Levenberg–Marquardt training algorithm was applied to educate artificial neural network. To validate the designed neural network, it was tested using a new test data set which is not applied in training. A simulation was performed on a three-dimensional model of MSC.ADAMS software using angle values obtained from artificial neural network test. It was revealed from this simulation that trajectory of plasma cutting torch obtained using artificial neural network agreed well with desired trajectory.
Selection of dry drilling parameters for minimal burr size and desired drilling quality
Authors: Azarrang Sona , Baseri Hamid
Published: December 2015

The drilling of metals produces undesired raised material which is defined as burr. It is important to minimize the burr size by modifying the drill geometry or selection of drilling parameters. Although, selection of optimal drilling parameters can be minimize the burr size, but it may be increases the overcut or decreases the material removal rate (MRR). In this paper, drilling parameters have been selected for minimal burr size and desired overcut and MRR. Four adaptive neuro fuzzy inference system (ANFIS) models have been designed based on experimental observation in drilling of copper. Outputs of ANFIS models are burr height, burr thickness, burr type and overcut of hole; While input parameters of drilling process are cutting speed, tool diameter and ratio of feed rate to diameter. Then the particle swarm optimization method has been used to select the optimum condition of input parameters to minimize the burr size in desired value of overcut and MRR. Results showed that the proposed models can be predict the outputs well and they can be used as adequate predictors and optimizer for achieving the drilling parameters which gives a type of burr with low value of burr height and burr thickness with desirable overcut and MRR.
Experimental and theoretical study of large deformation of rectangular plates subjected to water hammer shock loading
Authors: Babaei Hashem , Mirzababaie Mostofi Tohid , Alitavoli Majid
Published: December 2015

This paper presents experimental and analytical investigation of the dynamic inelastic response of rectangular metal plates subjected to liquid shock loading. A series of experimental results on fully clamped aluminum alloy and mild steel rectangular plates of different thickness and varying standoff distance of hammer is reported. The effect of varying both shock load and the plate material on the deflection is described. Also, an analytical procedure based on an upper bound solution is used to theoretically study the dynamic behavior of uniform impacted plates. In the present model, effects of strain rate and bending/membrane strain are assumed. The results of the analytical model and the experimental data have good agreement. So, this model can be useful for predicting deformation of rectangular plates under low impact loading.
Study on affecting factors of temperature–pressure–stress-coupled field of lpg tank under fire based on Legendre wavelet finite element method
Authors: Zhao Bin
Published: December 2015

In recent years, many explosion accidents of LPG (Liquefied Petroleum Gas) tank happen due to fires, temperature-pressure-stress coupled field parameters of LPG tank under fire change nonlinearly, which are affected by many factors, such as fire type and filling rate. In order to improve the computing efficiency, the Legendre wavelet function is combined with traditional finite element to construct the Legendre finite element, and the effect of every affecting factor on changing rule of coupled field of LPG tank under fire can be analyzed effectively. First, the basic property of Legendre wavelet is analyzed. Second, temperature–pressure–stress-coupled model of LPG under fire is constructed; the temperature-pressure-stress coupled Legendre wavelet finite element is established; and then the effect of every affecting factor on coupled field of LPG tank under fire is obtained. Results show that analysis precision based on Legendre wavelet finite element method can be improved effectively.
Three-dimensional finite element model of friction drilling process in hot forming processes
Authors: Bilgin Mehmet Burak , Gök Kadir , Gök Arif
Published: December 2015

Friction drilling processes are used commonly in hot forming operations. This process is similar to drilling processes but without using chip. This process is used especially for joining thin-walled metal components. In this study, the drilling process using centerdrill is investigated both experimentally and numerically. The finite element analyses (FEA) were conducted using deform-3D software based on finite element method (FEM). In this study, an analytic model is developed, which calculate the process parameters as torque and axial power, heat transfer coefficient. A comparison was also made for temperature, torque and axial force obtained from experimental and numerical analyses. At the end of the study, while the torque and axial force values decrease with increasing of spindle speed, temperature values of centerdrill and workpiece increase with increasing of spindle speed. A good consistency between both experimental and FEA simulations was found during the centerdrill process.
Joint strength of gasketed bolted pipe flange joint under combined internal pressure plus axial load with different (industrial and ASME) bolt-up strategy
Authors: Khan Niaz B , Abid Muhammad , Jameel Mohammed , Wajid Hafiz Abdul
Published: December 2015

Gasketed bolted flange joints are used in process industry for connecting pressure vessels and pipes. Design procedures available in the literature mostly discuss structural strength, while sealing failure is still a big concern in industries. Similarly, limited work is found in the literature regarding performance of gasketed bolted joints under combined loading. A detailed 3D nonlinear finite element analysis is performed to study the strength and sealing of a gasketed bolted flanged pipe joint under different bolt-up strategy (Industrial and ASME) and under combined internal pressure and axial loading.
New simulation-based approach for the profile control in a process chamber: Fluid, thermal, and plasma profile
Authors: Xiang Dong , Xia Huanxiong , Yang Wang , Mou Peng
Published: December 2015

Process chamber is the core unit of chemical vapor deposition and etching, and the physical fields in it have fatal effect on process quality. It is significant and difficult for improving the process performance to regulate the fields’ profiles finely. Two design solutions for the profile regulation are proposed: controllable type and resistance type. A novel profile error feedback method is presented, and a simulation-based auto-design framework is established. The profile error feedback method is in a quasi-closed-loop-control mode. It starts from an initial guessed sequence of the design/control variables and predicts a better sequence via feedback of the profile error between the output-targeted profile and the expected one. It never stops until the profile error is narrowed in the preset tolerance. Three kinds of numerical experiments about the regulation of the thermal, fluid, and plasma profile are set to test the effectiveness and feasibility of the profile error feedback method and the two kinds of design schemes.
Pressure variation and effective sensing zone around small leaks inside water pipelines for reliable leak detection
Authors: Khalifa Atia E
Published: December 2015

Detecting and locating small leaks in the water distribution networks save water and help in making critical decisions about the network and the infrastructure. In this work, inside-pipe pressure measurements are used to evaluate the local variation of the pressure around small circular leaks as compared to main pipeline pressure, for reliable leak detection. The technique is working for pressurized pipelines and may be used for liquids and gases. In addition, since large leaks are easy to find, the attention is given to detecting small leaks, which are difficult to be detected using the commercial acoustic methods; specifically with plastic pipes. The current study thereafter helps in characterizing the effective zone of pressure sensing around the leak. A pressure probe, mounted on a movable platform, moves inside a water-pressurized pipe very close to the wall in order to measure the pressure variation at the vicinity of the leak. The effects of pipeline pressure, leak size, and the clearance distance between the pipe wall and the pressure probe on the measured pressure drop around the leak are investigated. Results showed that direct pressure measurements inside the pipe can be effectively used for leak detection. The local pressure drop due to the small leak is very localized around the leak and captured within the leak diameter in the longitudinal direction and almost leak-like radius above the leak in the radial direction. As the line pressure increases, the measured pressure drop increases but the zone of pressure variation is still confined around the leak itself. If the sensor is moving over the leak, then the magnitude of the measured pressure drop is inversely proportional to the sensor speed inside the pipe.
Optimal performance of plastic pipes’ extrusion process using Min-Max model in fuzzy goal programming
Authors: Al-Refaie Abbas
Published: December 2015

The main objective of this research is to optimize performance of plastic pipes’ extrusion process with two main quality responses, including pipe’s diameter and thickness, using Min-Max model in fuzzy goal programming. First, the variables control charts are constructed at initial factor settings of extrusion process, where the results reveal that the extrusion process is in statistical control. However, the actual capability index values for diameter and thickness are estimated 0.7094 and 0.7968, respectively. The process capability for a complete product, MCpk, is calculated as 0.752. These values indicate that the extrusion process is incapable. To improve process performance, the L18 array is utilized for experimental design with three 3-level process factors. Then, the Min-Max model is used to determine the combination of optimal factor settings. The estimated capability index values for diameter and thickness at the combination of optimal factor settings are estimated and found to be 1.504 and 1.879, respectively. The integrated process capability index, MCpk, is calculated as 1.681. Confirmation experiments should that the Min-Max model results in enhancing process capability for both responses. In conclusions, the Min-Max Model may provide valuable assistance to practitioners in optimizing performance while considering both product and process preferences.
Comparison of the efficiency of the high speed low torque hydrostatic drives using bent axis motor: An experimental study
Authors: Hasan Md. Ehtesham , Dasgupta K , Ghoshal Sanjoy
Published: December 2015

This article is aimed at analysing the steady-state performance of four hydrostatic drives and compares their overall efficiency. The speed of the hydrostatic drives is controlled by speed controlled vane pump, variable displacement flow compensated pump, variable displacement pressure compensated pump and proportional direction controlled valve. Bondgraph simulation technique is used to model the hydrostatic drive. The relationships of the loss coefficients with the state variables obtained from the model are identified through experimental investigation. Using them, at different torque levels, the performances of the hydrostatic drives are studied on their slips, torque losses and the overall efficiencies and they are validated experimentally. It is found that hydrostatic drive using speed controlled vane pump exhibits the maximum efficiency, whereas the poorest efficiency is shown by the valve controlled system out of the four drives considered in the analysis.
Electro-polishing of tungsten carbide ball nose end mill to improve tool life
Authors: Kuppuswamy Ramesh , Mubita Kapui
Published: December 2015

Electro-polishing was used as an alternative to mechanical polishing for the cutting edge preparation of tungsten carbide (WC) ball nose end mills. High-quality cutting edge surfaces with roughness of magnitude 0.3–0.35 µm was achieved using the electro-polishing process. A direct current of 0.96 A was passed through an electrolytic cell containing the electrolyte sodium hydroxide with a concentration—2.5 mol/dm3. The ball nose end mill was suspended as the anode and a stainless steel (SS304) as the cathode. The ball nose end mill was electro-polished using the optimized parameters which was obtained through performing the preliminary experiments on tungsten carbide coupons of size D6 × 20 mm. The effects of electro-polishing on the surface texture of the ball nose end mill were determined using surface texture examinations. Machining tests were conducted on Ti6Al4V alloy to understand the growth of flank wear on the electro-polished ball nose end mills. After every 5 m of cutting distance, flank wear measurements were done for both the regular ball nose end mill and the electro-polished ball nose end mills. The results revealed that the electro-polished ball nose end mill reached a flank wear of 0.15 mm after a cutting distance of 550 m. This was significantly more than the cutting distance of the standard ball nose end mill of magnitude 350 m for the same amount of flank wear. This showed an increase in tool life of over 50%.
Experimental measurement of dynamic load parameters for pier pile caps of high-speed railway bridges
Authors: Nie Rusong , Chen Y Frank , Leng Wuming , Yang Qi
Published: December 2015

Train-induced dynamic responses and loads in bridge pier systems are not well understood. In this study, five different piers from two separate railway bridges were investigated experimentally. The dynamic responses and loads at the bridge beam ends, pier tops, and pile caps were measured by considering various train speeds. The frequencies of the dynamic loads on pile caps were also analyzed. The results show that the induced dynamic response decreases significantly with the descending pier height. The train-induced vertical dynamic displacements are related to the axle loads and the stiffness of the pile foundation and foundation soils. The accelerations at pier tops and pile caps are very similar but noticeably less than those at beam ends. The train-induced vertical dynamic loads on pile caps increase with the total span length. The measured change of dynamic forces (Δ Q) is approximately 20 − 30% of the measured peak loads ( Q). In addition, the results show that the frequency (f) varies linearly with the train speed rather than with the bridge span length.
Designing the Ornicopter, a tailless helicopter with active flapping blades: a case study
Authors: Wan Jia , Pavel Marilena D
Published: December 2015

The Ornicopter concept is a single-rotor, tailless configuration. By actively flapping its blades, the Ornicopter rotor can propel itself to rotate, and hence does not need a tail rotor. In previous research, the Ornicopter concept has been compared with the Bo-105 conventional helicopter from various aspects, while the Ornicopter has the same design parameters as the Bo-105. Comparisons show that the Ornicopter has one major drawback, namely a small flight envelope. To improve the Ornicopter performance and understand how the Ornicopter should be designed, in this paper, the Ornicopter design is unfrozen and optimized for the flight envelope. The optimization result shows that with a proper design, the Ornicopter performance can be improved dramatically. A similar flight envelope as the Bo-105 can be achieved for the Ornicopter. However, the Ornicopter requires higher power than the Bo-105 due to the inherent characteristics of this concept.
Mars atmospheric entry trajectory optimization via particle swarm optimization and Gauss pseudo-spectral method
Authors: Jiang Xiuqiang , Li Shuang
Published: December 2015

In this paper, a hybrid optimization strategy using particle swarm optimization and Gauss pseudo-spectral method is proposed to generate the optimal entry trajectory of Mars pin-point landing mission. This hybrid optimization strategy merges global optimization with local optimization. Coarse optimization is first conducted to provide a global relative suitable initial guess for subsequent local accurate optimization, which can greatly improve optimization efficiency and robustness and produce the optimal Mars atmospheric entry trajectory from the present position to the designed terminal state satisfying the path constraints. The validity of the hybrid optimization strategy developed in this paper is confirmed by computer simulation in the presence of aerodynamics uncertainties.
Topological characterization of vortex structures on a transonic compressor stator during the stalling process
Authors: Kan Xiao-xu , Lu Hua-wei , Zhong Jing-jun
Published: December 2015

Numerical simulations, verified against experimental results, were used to study the stalling process of a transonic compressor. The method of topological analysis was used to study the distribution of the flow field on the blade surface in detail. In this manner, the steady three-dimensional vortex structure of the transonic compressor stator under transition conditions was established, and the mechanism of the stalling process was revealed from the perspective of the vortex structure evolution. The results show that in the process of stalling, as the back pressure increases, the separation areas on the suction side of the stator and the scale and strength of the separation vortex also increase, thereby weakening other vortices and causing a large amount of low-energy fluid to accumulate in the passage. Thus, the passage is blocked, and the through-flow capability of the compressor is reduced. In addition, because of the complex movement of the vortices and the transport of low-energy fluid clusters, the boosting capacity of the compressor is reduced, thus causing the compressor to stall.
Varieties of youth welfare citizenship: Towards a two-dimension typology
Authors: Chevalier Tom
Published: December 2015

How do welfare states deal with the period of the life course that is youth? In this article, we propose a two-dimension typology in order to account for cross-national variation in the access to financial independence of young people, that is, what we call ‘youth welfare citizenship’. The first dimension addresses the issue of welfare support, and distinguishes between a familialization perspective, according to which young people are seen as children, and an individualization perspective, in which they are considered as adults. The second dimension relates to the integration into the labour market, which can either provide skills for every young person in an encompassing strategy, or deliver such skills only to a specific part of the youth population in a more selective strategy. It leads to four regimes of youth welfare citizenship, which we identify in the article: the denied citizenship, the monitored citizenship, the second-class citizenship and the enabling citizenship.
Toxicological evaluation of Prussian blue nanoparticles after short exposure of mice
Authors: Chen Y , Wu L , Wang Q , Wu M , Xu B , Liu X , Liu J
Published: December 2015

Prussian blue nanoparticle (PBNP), a new type of theranostic nanomaterial, had been used for cancer magnetic resonance imaging and photothermal therapy. However, their long-term toxicity after short exposure in vivo was still unclear. In this study, we investigated the dynamic changes of the biochemical and immunity indicators of mice after PBNPs injection through tail vein. Histological results showed that the PBNPs were mainly accumulated in liver and spleen. In the spleen, we found the frequency of T cells was starting to decrease after 1 day of PBNPs injection, but then slowly recovered to normal level after 60 days of injection. Meanwhile, the frequency of T cells in the blood was firstly decreased after the PBNPs injection, and then the T cell frequency kept increasing and recovered back to normal levels after 7 days of injection. The serum indexes of liver functions (alanine transaminase, aspartate transaminase, total bilirubin, and alkaline phosphatase) increased rapidly to a relatively high level only after 1 h of injection, which meant certain acute liver damage, but these indexes were gradually decreased to normal levels after 60 days of injection. These results indicate that PBNPs have acute toxicity in vivo, however, their long-term toxicity after short-time exposure is low, which might provide guidance for further applications of PBNPs in future.
Association between interferon-γ +874 T/A polymorphism and susceptibility to autoimmune diseases: a meta-analysis
Authors: Lee Y H , Bae S-C
Published: December 2015

Objective

The aim of this study was to explore whether the interferon ( IFN)-γ +874 T/A polymorphism plays a role in modifying the risk of autoimmune diseases.

Methods

A meta-analysis was conducted on the association between the IFN-γ +874 T/A polymorphism and autoimmune diseases.

Results

Eighteen studies with a total of 2952 patients and 3832 controls were included in the meta-analysis. The meta-analysis revealed no association between autoimmune diseases and the IFN-γ +874 T allele in all study subjects (odds ratio (OR)=1.023, 95% confidence interval (CI) = 0.894–1.171, p = 0.738), but stratification by ethnicity indicated an association between the IFN-γ +874 T allele and autoimmune diseases in Latin American subjects (OR = 0.780, 95% CI = 0.629–0.953, p = 0.015). Meta-analysis also revealed an association between autoimmune diseases and the IFN-γ +874 T/A polymorphism in Caucasian and Middle Eastern subjects under a dominant inheritance model (OR = 0.686, 95% CI = 0.489–0.964, p = 0.003; OR = 1.414, 95% CI = 1.102–1.813, p = 0.006). Meta-analysis by autoimmune disease type indicated an association between ITP and the IFN-γ +874 T allele (OR = 1.753, 95% CI = 1.228–2.503, p = 0.002), but not for vasculitis, vitiligo, and auto-immune thyroid disease. Meta-analysis also showed a significant association between the IFN-γ +874 T/A polymorphism and systemic lupus erythematosus (SLE) under the dominant model (OR = 1.668, 95% CI = 1.114–2.497, p = 0.013).

Conclusions

This meta-analysis indicates that the IFN-γ +874 T/A polymorphism may play a significant role in modifying the risk of autoimmune diseases in Caucasian, Latin American, and Middle Eastern subjects, and in particular shows that the IFN-γ +874 T/A polymorphism is associated with increased genetic susceptibility to idiopathic thrombocytopenic purpura and SLE.
‘Playing on the break’: Karl Polanyi and the double-movement ‘Against Modern Football’
Authors: Webber David M
Published: December 2015

While the popularity of English football increases worldwide, there has been a marked rise in the discontent expressed by a small but growing group of domestic fans. This dissent has led to the emergence of a movement broadly defined as being ‘Against Modern Football’ (AMF), a banner under which fans of rival clubs have gathered in an attempt to challenge the poor governance, commercialism and greed that has come to dominate the English game. This article offers a conceptualisation of what it means to be ‘against modern football’ based upon Karl Polanyi’s analysis of the market society. Developing the dialectic of the ‘double-movement’ that appears in Polanyi’s most famous work, The Great Transformation, this article demonstrates how these governing principles might be useful in explaining both the complex cultural political economy of English football and the possibilities that exist for the AMF movement to socially re-embed the modern game.
Inconvenient Truths
Authors: Clark James J. , Yegidis Bonnie L.
Published: December 2015

David Stoesz offers a sweeping critique of the Children’s Bureau and social work education by claiming the existence of a “child welfare cartel.” He also attacks the quality of social work education and research, which he claims has poorly invested government funding and helped create the unmitigated failures of the American child welfare system. However, closer examination reveals that many of his claims, while dramatic, are actually ill conceived and unsupportable. We attempt to clarify and inform readers about some significant aspects of the field of child welfare and the contemporary responses being made by the federal government in partnership with social work educators and researchers.
Parameter estimation of an anisotropic damage model for concrete using genetic algorithms
Authors: Wardeh Muhammad A , Toutanji Houssam A
Published: December 2015

This article presents an anisotropic damage model for concrete that couples between elasticity and continuum damage mechanics. The formulation of constitutive model is based on the elastic strain energy in the framework of irreversible thermodynamics. The thermodynamic free energy is represented as a scalar function of elastic strain and damage tensors and used to derive the constitutive law and thermodynamic conjugate force of damage that is used to derive the dissipation potential. The damage evolution law is governed by the normality rule. The formulation of elastic strain energy of damaged material is capable of modeling the concrete anisotropic behavior under different loadings without decoupling the stress or damage release rate. A series of unknown parameters in the model formulation was used to control the constitutive behavior and damage surface. A Genetic algorithm FORTRAN subroutine is used to estimate these parameters based on the coupling between the constitutive and damage evolution equations. The performance of the damage model is verified with the experimental data from the literature. The model has shown a good agreement with the experimental results. It describes the anisotropy induced by the crack development within the concrete.
Association of Statin Therapy and Risks of Cholelithiasis, Biliary Tract Diseases, and Gallbladder Procedures
Authors: Martin Donald , Schmidt Robert , Mortensen Eric M. , Mansi Ishak
Published: December 2015

Background: Gallstone disease is a leading cause of morbidity in Western countries and carries a high economic burden. Statin medications decrease hepatic cholesterol biosynthesis and may, therefore, lower the risk of cholesterol cholelithiasis by reducing the cholesterol concentration in the bile. Population-based evidence, however, is sparse. Objective: To assess the risk of gallbladder diseases among statin users compared with nonusers in an American patient cohort. Methods: We performed a retrospective cohort study of patients enrolled in the San Antonio Tricare health system using data between October 2003 and March 2012. We defined 2 groups: statin users (use for 90 days or greater) and nonusers (no prior statin). A propensity score based on 82 variables was generated to match statin users and nonusers 1:1. Outcomes included incidence of cholelithiasis, biliary tract diseases, and gallbladder procedures. Results: A total of 43 438 patients were identified; 13 626 (31.4%) were statin users, and 29 812 (68.6%) were nonusers. We matched 6342 pairs of statin users and nonusers based on propensity score. The odds ratios (ORs) in statin users in comparison to nonusers were similar for cholelithiasis (OR = 0.86; 95% CI = 0.73, 1.02), biliary tract disease (OR = 0.85; 95% CI = 0.67-1.08), and gall bladder procedures (OR = 0.85; 95% CI = 0.69, 1.04). Conclusions: Statin use was not significantly associated with either an increased or decreased risk of cholelithiasis or gallbladder disease.
Cyproheptadine for the Prevention of Postoperative Delirium
Authors: Mohammadi Mostafa , Ahmadi Motahareh , Khalili Hossein , Cheraghchi Horiyeh , Arbabi Mohammad
Published: December 2015

Background:Postoperative delirium is a common neurobehavioral complication after major surgeries. There is no conclusive approach for prevention of delirium in these patients. Objective: In this study, efficacy of cyproheptadine for prevention of postoperative delirium was evaluated. Methods: Delirium status of surgical patients was evaluated postoperatively at the time of admission to the intensive care unit (ICU) using the Confusion Assessment Method (CAM-ICU) scale. Patients without delirium were assigned to the cyproheptadine or placebo group based on the simple randomization method. Patients received cyproheptadine or placebo tablet at a dose of 4 mg 3 times per day for 7 days. Patients were monitored daily for incidence of delirium. Results: Changes in the incidence rates of delirium over time during the study phase ( P = 0.04) and between the groups showed statistically significant differences ( P = 0.029). However, severity of delirium was not significantly different between the cyproheptadine and placebo groups during the study period. Conclusion: It seems that cyproheptadine with its diverse effects can be a potential option for prevention of postoperative delirium. In this pilot study, cyproheptadine significantly decreased the incidence but not severity of postoperative delirium.
Scientific Communication about Biological Influences on Homosexuality and the Politics of Gay Rights
Authors: Garretson Jeremiah , Suhay Elizabeth
Published: December 2015

In recent decades, Americans’ thinking regarding the causes of human behavior has changed considerably. In particular, there has been a swing toward attributing a variety of behaviors to biological factors, and perhaps nowhere is this more evident than for sexual orientation. In this paper, we draw on two overtime survey datasets to argue that new scientific evidence on the biological bases of homosexuality in the 1990s rapidly changed commonly held beliefs. However, because these scientific explanations were perceived to be relevant to gay rights, persuasion tended to be conditioned on citizens’ political values. In short, liberals were considerably more likely than conservatives to embrace biological attributions for homosexuality during this period. Furthermore, these changing—and diverging—causal beliefs about homosexuality appear to have contributed to both increasing support for, and left–right disagreements over, gay rights.
Radiographic Indicators of Surgery and Functional Outcome in Ponseti-Treated Clubfeet
Authors: Shabtai Lior , Hemo Yoram , Yavor Ariela , Gigi Roy , Wientroub Shlomo , Segev Eitan
Published: December 2015

Background:

Evaluation of the results of treatment for clubfoot by the Ponseti technique is based on clinical and functional parameters. There is a need to establish universally recognized quantitative measurements to compare, better understand, and more precisely evaluate therapeutic outcome.

Methods:

Nine angles were measured on standard radiographs of 145 children with idiopathic clubfeet treated between 2000 and 2010 with the Ponseti method. The average follow-up was 6.3 years. The need for additional surgery and the functional outcome was correlated to the radiologic measurements.

Results:

Three radiologic parameters were identified as having significant ( P ≤ .001) predictive value. The lateral tibiocalcaneal angle with the ankle at maximal dorsiflexion measuring fixed equinus was larger in the preoperated group (77 ± 12 degrees) compared to the nonoperated group (67 ± 14 degrees). Functional outcome was better with smaller angles. The lateral talocalcaneal angle with the ankle at maximal dorsiflexion measuring hindfoot rigidity was smaller (29 ± 8 degrees) in the preoperated group compared to the nonoperated group (35 ± 9 degrees). Functional outcome was better with larger angles. The lateral talo-first metatarsal angle with the ankle at maximal plantarflexion measuring foot cavus was larger in the preoperated group (31 ± 10 degrees) compared to the nonoperated group (22 ± 11 degrees), whereas functional outcome did not correlate with this angle.

Conclusions:

The lateral view with the foot in maximal dorsiflexion was found to be the most significant and useful view to detect abnormality in Ponseti-treated clubfeet. In our practice now, we are using only this view in order to reduce the radiation exposure to the child.

Level of Evidence:

Level III, retrospective case series.
Correlation of Postoperative Position of the Sesamoids After Chevron Osteotomy With Outcome
Authors: Shi Glenn G. , Henning Peter , Marks Richard M.
Published: December 2015

Background:

Postoperative incomplete reduction of the sesamoids has been identified as a potential risk factor for hallux valgus recurrence after proximal osteotomy. However, it is not known whether the postoperative sesamoid position is a risk factor in hallux valgus correction via distal chevron osteotomy with or without dorsal webspace release (DWSR).

Methods:

In this retrospective study, 169 patients who underwent distal chevron osteotomy with or without DWSR were reviewed. Preoperative and postoperative (6 weeks, 6 months, 12 months) weightbearing radiographs were evaluated. Functional hallux valgus angle (HVA), intermetatarsal angle (IMA), and the position of the tibial sesamoid were graded using the center of head method. Seventy-six radiographs were available for review at the 12-month follow-up. Of these, 41 patients underwent DWSR procedure and 35 did not.

Results:

In both groups, correction of all 3 parameters (HVA, IMA, tibial sesamoid position) were significant at the 12-month follow-up. Comparison of the postoperative results of the 2 groups showed no statistically significant differences. Four feet demonstrated displaced sesamoid position at the 12-month follow-up, with radiographic evidence of recurrence in just one. No significant relationship was found between postoperative sesamoid position and hallux valgus recurrence that occurred in 4 feet.

Conclusion:

Combining DWSR with a distal chevron osteotomy did not delay healing or increase risk of avascular necrosis, but it did not significantly improve angular measurements or sesamoid position. The concept that postoperative sesamoid position can be used to predict hallux valgus recurrence was not supported by our results when looking at distal chevron correction.

Level of Evidence:

Level III, retrospective comparative study.
Operative Treatment of Acute Fractures of the Tarsal Navicular Body
Authors: Schmid Timo , Krause Fabian , Gebel Philippe , Weber Martin
Published: December 2015

Background:

Treatment of displaced tarsal navicular body fractures usually consists of open reduction and internal fixation. However, there is little literature reporting results of this treatment and correlation to fracture severity.

Methods:

We report the results of 24 patients treated in our institution over a 12-year period. Primary outcome measurements were Visual-Analogue-Scale Foot and Ankle score (VAS-FA), AOFAS midfoot score, and talonavicular osteoarthritis at final follow-up. According to a new classification system reflecting talonavicular joint damage, 2-part fractures were classified as type I, multifragmentary fractures as type II, and fractures with talonavicular joint dislocation and/or concomitant talar head fractures as type III. Spearman’s coefficients tested this classification’s correlation with the primary outcome measurements. Mean patient age was 33 (range 16-61) years and mean follow-up duration 73 (range 24-159) months.

Results:

Average VAS-FA score was 74.7 (standard deviation [SD] 16.9), and average AOFAS midfoot score was 83.8 (SD = 12.8). Final radiographs showed no talonavicular arthritis in 5 patients, grade 1 in 7, grade 2 in 3, grade 3 in 6, and grade 4 in 1 patient. Two patients had secondary or spontaneous talonavicular fusion. Spearman coefficients showed strong correlation of the classification system with VAS-FA score ( r = −0.663, P < .005) and talonavicular arthritis ( r = 0.600, P = .003), and moderate correlation with AOFAS score ( r = −.509, P = .011).

Conclusion:

At midterm follow-up, open reduction and internal fixation of navicular body fractures led to good clinical outcome but was closely related to fracture severity. A new classification based on the degree of talonavicular joint damage showed close correlation to clinical and radiologic outcome.

Level of Evidence:

Level IV, retrospective case series.
Item Response Theory Modeling and Categorical Regression Analyses of the Five-Factor Model Rating Form: A Study on Italian Community-Dwelling Adolescent Participants and Adult Participants
Authors: Fossati Andrea , Widiger Thomas A. , Borroni Serena , Maffei Cesare , Somma Antonella
Published: December 2015

To extend the evidence on the reliability and construct validity of the Five-Factor Model Rating Form (FFMRF) in its self-report version, two independent samples of Italian participants, which were composed of 510 adolescent high school students and 457 community-dwelling adults, respectively, were administered the FFMRF in its Italian translation. Adolescent participants were also administered the Italian translation of the Borderline Personality Features Scale for Children–11 (BPFSC-11), whereas adult participants were administered the Italian translation of the Triarchic Psychopathy Measure (TriPM). Cronbach α values were consistent with previous findings; in both samples, average interitem r values indicated acceptable internal consistency for all FFMRF scales. A multidimensional graded item response theory model indicated that the majority of FFMRF items had adequate discrimination parameters; information indices supported the reliability of the FFMRF scales. Both categorical (i.e., item-level) and scale-level regression analyses suggested that the FFMRF scores may predict a nonnegligible amount of variance in the BPFSC-11 total score in adolescent participants, and in the TriPM scale scores in adult participants.