bluuebunny/crossref_metadata_2025 huggingface dataset:
The Analysis of Bolted Flange Joints under Internal Pressure at High Temperature
Authors: Zheng Xiao Tao , Cheng Yang , Yu Jiu Yang
Published: October 2016

Working temperature, internal pressure and the creep of bolted flange joints are the direct factors that influencing the gasket stress of bolted flange joints, the tightness of the whole system will be reduced because of these factors. thus the security level of bolted flange connection will be affected. In this paper, the deformation coordination equation of bolted flange connection system, the gasket compressive and resilient performance, as well as the gasket creep equation are combined to study the effect of internal pressure on bolted flange connections under a certain bolt preload and operating temperature, the equation about the relationship of the gasket force and internal pressure is simplified, and the main objective of the work is the calculation of the time-correlated gasket force, flange rotation and gasket unloading deformation under the different internal pressure. The results show that when the internal pressure is greater, the gasket force is smaller, on the contrary, the leakage rate are greater. Through the relevant conditions, in a period of the safe operation time, the maximum working internal pressure is got when reaching the condition of corresponding level of tightness.
Strain Analysis of Oil and Gas Pipeline with Dents Based on ILI Data
Authors: Lei Zheng Qiang , Chen Jian , Wang Fu Xiang , Wang Ting , Zhou Li Jian
Published: October 2016

Dents in an oil and gas pipeline can be detected by In-line-Inspection (ILI), and structure integrity analysis of the pipe with theses reported dents is important for the safe operation. Strain analysis of the dented pipe is a way of fine assessment and ASME B31.8 has established the strain assessment code and its acceptable range. However, the method of strain assessment is rarely used due to the difficulty of strain calculation for a buried pipe. In this study, features of ILI data are investigated to elaborate the necessary of filtering analysis for strain analysis of the dent with ILI data. Then typical filtering methods are used to smooth the ILI data, and strain analysis are carried out with the smoothed data to study the practicability of strain assessment. Profile and strain of a dent in D813 pipe were obtained by Finite Element Method (FEM). Then different filtering methods were used to smooth the simulated ILI data of the dent which were selected from FEM profile. Strain of the dent were also calculated by smoothed data with the latest ASME B31.8 code, and compared with it from FEM at last to prove the feasibility and validity of the filtering methods with ASME B31.8 code.
Characterization of High-Power COB LED Module Attached by Low-Temperature Sintered Nanosilver
Authors: Chen Jia , Li Xin , Kong Ya Fei
Published: October 2016

Along with the increasing demand of high power LED (>1W), multi-chip modules have made great progress to an inevitable trend. Thus, large packaging area is needed to dissipate heat efficiently. In other words, only when we find appropriate packaging materials to control the junction temperature well, can we achieve high-power LED devices in smaller packaging area. Obviously, a die-attach layer as the first-level packaging has a most significant impact on the thermal performance of a power module. So we introduce a novel die-attach material, nanosilver paste, which can be used for connecting multi-chips on the substrate because of its higher melting temperature and better thermal/electrical conductivity than conventional solders and adhesive films. What is more important, because of their ability to emit high brightness, LED packages are being exploited for other systems or fields, and in most cases are exposed to harsher environments. Therefore, the performance and stability of LED packages will be the key to assuring the reliable function of systems. So, in this paper, the optical and electrical properties of the LED device operating under various ambient temperatures from 27 to 120°C were determined. The test results showed that nanosilver paste was a very promising die-attach material in high power multi-chip modules packaging.
Manufacturing Issues and the Resulting Complexity in Modeling of Additively Manufactured Metallic Microlattices
Authors: Rashed M.G. , Ashraf Mahmud , Hazell Paul Jonathan
Published: October 2016

Although metallic microlattice material is a sought after research topic currently, it suffers from manufacturing defects such as micro-voids formation due to missed fusion, stemmed from the stacking-layered-fused nature of the metal powder in Powder Bed Fusion (PBF) process. These defects result in weakening of the finished part and reduced mechanical performance under service load, possibly leading to low fatigue strength, and raise serious question about 3D printed structural integrity. Numerical simulation of the built parts also becomes difficult due to irregular physical properties including geometry and anisotropic nature of mechanical properties. This paper provides an overview on the manufacturing issues and the subsequent hurdle faced in numerical simulation of metallic microlattices. While the issues in manufacturing are related to emerging additive manufacturing techniques and out of control of end users, it has been suggested that the limitations in numerical simulation can be overcome by employing advanced approaches, in both physical properties measurement and modeling.
A Comparative Study on the Wear and Corrosion Resistance of Coatings
Authors: Chen Cheng Zhou , Wang Wei Ze , Cheng Kai Di
Published: October 2016

The vessel containing sulfur particles has been found failing due to the effect of corrosion and erosion by the sulfur particles. Several coatings, including zinc-aluminum coating, wear-resistance painting and two kinds of polymer, have been provided to resist the negative influence of sulfur in the present study. The wear and corrosion resistance of the selected coatings has been measured to study the performance difference. Impact test has also been done to investigate the bonding condition of coatings under the impact or bending load. The microstructure of coatings before and after wear test is observed by the Optical Microscope (OM) and Scanning Electron Microscope (SEM). The experiment results reveal that one of the polymer coatings shows the best performance in the corrosion resistance, another polymer coating’s wear resistance is better than others. The coatings are bonded well with the substrate except the zinc-aluminum coating. The performance of painting is ordinary in this investigation.
Structural Integrity for the RPV of French NPP during the LRA
Authors: Chen Ming Ya , Yu Wei Wei , Shi Jin Hua , Wang Rong Shan , Feng Lv , Xue Fei , Chen Zhi Lin
Published: October 2016

Most of the French Nuclear Power Plants (NPPs) are currently embarking upon efforts to renew their operating license, while the pressurized thermal shock (PTS) events and environmentally assisted fatigue (EAF) pose potentially significant challenges to the structural integrity of the reactor pressure vessel (RPV) which has the potential to be NPP life-limiting conditions. In the assessment of the PTS events, the deterministic fracture mechanics (DFM) is still used as the basic mechanics in most countries except for the USA. While the maximum nil-ductility-transition temperature (RTNDT) is about 80°C for 54 French RPVs after 40 years operation, the maximum allowable RTNDT is only about 70 oC and 80 oC for the typical PTS events in the IAEA and NEA reports, respectively. On the other hand, the effects of light water reactor (LWR) environmental (other than moderate environment in the code) were not considered in the original design, while the effects of LWR environmental are needed to be considered in the LRA according to the USA regulations. In this paper, the challenges of the PTS and EAF are discussed, and some suggestions are also given for the LRA
Maximum Likelihood Estimation Modeling of Welded Joints Based on Metal Magnetic Memory Parameters
Authors: Xing Hai Yan , Ge Hua , Dai Guan Ga , Yu Zheng Shuai , Sun Xiao Jun
Published: October 2016

In order to quantitatively identify critical hidden damage for weld joints by using the metal magnetic memory technology (MMM), the modified maximum likelihood estimation MMM model is first proposed. The experimental materials are Q235B welded plate specimens. Fatigue tension experiments were operated to find the MMM feature laws of critical hidden damage by comparing with synchronous X-ray detection results. Four MMM characteristic parameters, that is, ΔHp(y) , Kymax , mmax and S(K), are extracted corresponding to the normal state and the hidden damage state, respectively. The probability density values of ΔHp(y) , Kymax , mmax and S(K)are calculated by the optimized bandwidth kernel density estimation. The quantitative maximum likelihood estimation MMM model is established based on optimized bandwidth kernel density. The verification result shows the maximum likelihood value of hidden damage state is twice as much as that of the normal state, which is consistent with the practical results. This provides a new method for quantitative MMM identification of weld critical hidden damages.
Corrosion Diagnosis and Mechanism of Boiler Water-Cooled Wall Tubes in Alkaline Environment
Authors: Zhou Zhen Hua , Xue Dong Jian , Qian Sheng Jie
Published: October 2016

Failure analysis was carried out to find out the causes of burst on water-cooled wall tubes elbow for circulating fluidized bed (CFB) boiler.Through macro-observations, chemical composition analysis, macro structure observations，grain size measurements and water quality examinations, it can conclude that the high pH value of boiler water at the fire-facing side of weld dense phase zone will lead to alkali concentration that will cause alkali corrosion. The existence of residual stress in elbow under strong alkaline environment will cause alkali stress corrosion. Research results show that the tube failure is caused by both alkali corrosion and alkali stress corrosion. Strengthen water quality monitoring and elimination of stress can effectively prevent the alkali corrosion and alkali stress corrosion.
Failure Assessment of the First Stage High Pressure Turbine Blades
Authors: Wang Chan , Shi Duo Qi , Yang Xiao Guang
Published: October 2016

Ni-based superalloys are used as turbine blade material in which creep-fatigue is an important damage mechanism. Simulation and experiment methods are used to investigate and predicte the failure mechanism of the first stage high pressure turbine blades of an aeroengine after 600 hours service. The high pressure turbine blades were made of Ni-base superalloy DZ4, fabricated by DS investment casting. The largest stress point was obtained by finite element analysis. During the fatigue test, the high temperature and low cycle fatigue/creep load simulating the real working condition were applied on the blades until they fractured. And then several examinations were carried out to identify the fracture’s main cause, such as visual examination, SEM fractography and microstructural characterization. In conclusion, the fracture of the high pressure turbine blades was mainly caused by the interaction of the fatigue and creep. Besides, the oxidation accelerated the blades fracture.
Mean Stress and Ratcheting Corrections in Fatigue Life Prediction of Metals
Authors: Lei Qiang , Yue Peng , Liu Qiang , Zhu Shun Peng , Huang Hong Zhong
Published: October 2016

Considering the effects of mean stress, the progressive accumulation inelastic strain occurs in engineering components under the direction of mean stress, it is simply known as ratcheting. Based on the ductility exhaustion theory, a new model is proposed to account for the effects of mean stress and ratcheting on the component fatigue life. The capability and accuracy of the proposed model are compared with those of Walker, Xia-Ellyin, Goswami, GDP and Peng models. A comparison between the model prediction and tested life is found to be quite satisfactory in the cases of 9 sets of experimental data available in the literature under different loading conditions.
An Empirical Life Prediction Method of Cold-Stretched Austenitic Stainless Steel
Authors: Han Yu , Wang Ke Sheng
Published: October 2016

With the purpose of long-cycle safe operation of cold stretched austenitic stainless steel pressure vessels so as to achieve unification of economy and safety, prediction of fatigue life of S31603 austenitic stainless steel at high temperature is systematic studied. Based on the Hull-Rimmer cavity theory, a fatigue life prediction model applicable to stress controlled is developed. Fatigue test is carried out on the solution annealed and cold stretched S31603 steel at high temperature and corresponding test data is obtained. The fatigue life of the solution annealed and cold stretched materials is predicted by the model and the prediction results are in good agreement with the experimental results. On this basis, the life prediction model coupled with the strain level of cold stretching is further established. Compared with the test data, the prediction results is found to be very satisfactory with an error band less than ±1.5 times. The fatigue life prediction model suitable for stress control at high temperature is simple in form and has a clear and obvious physical significance which points out a new way to predict fatigue life of metal materials.
A Thermo-Mechanical Constitutive Model of Glassy Shape Memory Polymers
Authors: Li Jian , Dong Shi Yu , Kan Qian Hua , Kang Guo Zheng , Yan Wen Yi
Published: October 2016

Glassy shape memory polymer materials are applied successfully in biomedical fields due to their large recovery deformation, excellent biocompatibility and unique biodegradability. To predict the thermo-mechanical behavior of glassy shape memory polymers in biomedical devices accurately, a reasonably three-dimensional thermo-mechanical constitutive model must be established firstly. A one-dimensional linear-elastic constitutive model proposed by Tobushi et. al. (1997) was extended to capture the loading level dependent degradation of shape memory effect by introducing new nonlinear evolution equations with threshold values. Comparisons between experiments and simulations were carried to validate the extended model. Simulation results agree with experiments well, especially for the high loading levels.
Improving the Efficiency of Suspension for Automobiles Using Ferrofluid
Authors: Pugazhenthi N. , Karthick M. , Belgin Paul D.L.
Published: October 2016

In automobile application, suspensions are used for various purposes. To improve the stability and to withstand maximum load we are trying to add additional source which is called suspension. These suspensions are made attached along with the ordinary suspension. This is manufactured using magnetic fluid called ferrofluid. Here the complete preparation of ferrofluid was done and their characteristics were studied. In this, the experimental setup of suspension has been studied and working was analyzed. The fluid was prepared and compared the viscosity with ordinary fork oil. This liquid substance which acts as a source of suspension, which has maximum efficiency when compared to ordinary fluid. These can be varied to different shapes depending on the application and needs.
Cell Formation and Part Family Identification by Using Traditional Methods
Authors: Shunmuga Sundaram M. , Anbumalar V. , Anand P. , Aswinkumar B.
Published: October 2016

A Combined Algorithm is proposed to form the machine cell and part family identification in the cellular manufacturing system. In the first phase, part families identification, by using Rank Order Clustering (ROC) and Modified Single Linkage Clustering (MOD-SLC). In second phase, Machine cell formation, by using Rank Order Clustering (ROC) and Modified Single Linkage Clustering (MOD-SLC), which is to assign machines into machine cells to produce part families. The above Proposed method is tested by using standard problems and compared with other method results for the same standard problems. Grouping efficiency is one of the most widely used measures of quality for Cellular Manufacturing Systems.
Fabrication and Testing of Downdraft Gasifier for Solid Biomass
Authors: Keerthivasan K.C. , Nandhakumar S.
Published: October 2016

Bio mass was the fuel used for combustion and produce thermal energy. Gasification was a thermo chemical process it convert solid fuel into gaseous fuel. Gasification is the operation used to produce the combustible gas by burning solid biomass, that combustible gas is also named as producer gas. We are using downdraft gasifier to generate producer gas, why because the down draft gasifier produce a lesser amount of tar content and minimum pressure drop. In our country, large amount of solid waste like coconut shell, groundnut shell, carpentry wastage, bagasse this kind of waste is easily combustible biomass. So we can use that combustible waste to run the down draft gasifier to produce the producer gas. We have fabricated the down draft gasifier with 3.5kW power generation. Performance of gasifier has been analysed in-terms of different zone temperatures and pressure drop, wood consumption this things would be experimentally investigated.
Analysis to Determine Performance and Emission Characteristics of Diesel Blended with Calophyllum Inophyllum Methyl Ester (CIME) in a VCR Engine
Authors: Ranjithkumar M. , Varunraj S. , Raghav J. , Thangavel T.
Published: October 2016

The energy sources present in our world is dwindling day by day, in order to overcome these shortages an experimental analysis and investigation was carried out to get maximum benefit from the available resources .There are variety of fuels available suiting to the various requirement and it is mainly chosen on the basis of viscosity and free fatty acid content. An experimental study was conducted on the performance and emission characteristics of Variable Compression Ratio (VCR) diesel engine with Calophyllum Inophyllum Methyl Ester (CIME). A four stroke, single cylinder and water cooled engine of 4.4 kW rating and compression ratio 17.5:1, 18:1 and 18.5:1 was used for the experiment. Also the blend of B20 (20%CIME+80%Diesel), B40 (40%CIME+60%Diesel) and B60 (60%CIME+40%Diesel) biodiesel was used for conducting the performance and emissions tests at varying load conditions. Various parameters such as brake thermal efficiency, brake specific fuel consumption and emissions of smoke and unburnt hydrocarbon gases in exhaust were recorded .In order to satisfy these escalating needs, potential feedstock for biodiesel was analysed and process was carried out .Production of biodiesel from plant gives the tremendous way to overcome all the difficulties. The compression ratio has been set at 17.5, 18, and 18.5 to know the various characteristics of bio fuel. The type of software used to carry out the experiments are AVL INDICOM MOBILE software version v2.5 .The rated power and compression ratio were 4.4 kw and 16-22:1 .There will be an enormous growth in alternative fuel industry and it will be the future source of energy.
Multi-Response Optimisation of Cutting Parameters of Wire EDM in Titanium Using Response Surface Methodology
Authors: Sivaraman B. , Padmavathy Senthil , Jothiprakash P. , Keerthivasan T.
Published: October 2016

This Aim of this paper is to analyse the effect of machining parameters of wire electrical discharge machining (WEDM) on workpiece material titanium, that were now widely used in many applications because of its technical benefits. Conventional method of machining the material will make the work piece to crack or flaws due to chipping, presence of burrs and cracking. Wire cut Electrical discharge machining techniques have been already tried with some other high strength materials which is complicated to cut. To prove the feasibility of machining the titanium, many experiments were carried out based on RSM. Hence by the head wire electrical discharge machining process is to be used to machining the work piece material (titanium) and the effect of various control parameters on the response parameters were analysed and optimized and the optimal combination of control parameters were found to get higher metal removal rate and surface finish using Response Surface Methodology.
Synthesis of Hard-Melting Carbide, Nitrite and Intermetallic Phases with Surface Electron-Beam Microallоying
Authors: Jenek Mariuch , Fedorov Sergey Voldemarovich , Swe Min Htet
Published: October 2016

The experimental results prove the ability to produce layers modified by microalloying with electron-beam technology using wide range of materials. Such layers were produced due to initiating exothermic chemical reactions between the base and the thin film covered the base. This resulted in finding new phase compounds in reaction products.
Specifics of Wear of Ceramic Cutting Tool Inserts Featuring Al2O3-TiC Dies when Face Milling Hardened Cast Iron
Authors: Torrecillas San Millan Ramon , Seleznev Anton Evgenievich , Gurin Vladimir Dmitrievich , Peretyagin Pavel Yurievich
Published: October 2016

This work studies wear kinetics of index able inserts (II) made of mixed ceramics based on Russian-manufactured in case of fine milling of special hardened cast iron with globular graphite. In a wide range of cutting parameters typical for fine milling, an impact of tool insert wearing parameters on qualitative and quantitative characteristics of the cutting process have been studied. Morphological traits and nature of wear of work surfaces has been studied using optical and scanning electron microscopy. Criteria of II states, as well as specifics of contact work surface transformation, correlating with force parameters of the face milling process, have been determined.
Effect of Wear of Tool Cutting Edge on Detail Surface Layer Deformation and Parameters of Vibro-Acoustic Signals
Authors: Kozochkin Mikhail Pavlovich , Volosova Marina Aleksandrovna , Allenov Dmitry Gennadievich
Published: October 2016

This paper studies the computing possibilities of estimating the deformation of the surface layer in machining of details with cutting tools of different levels of wear. The calculation results were experimentally compared with the data obtained by the results of a grid distortion analysis in cutting. Results of how deformation intensity evaluation affects the parameters of vibroacoustic signal have also been presented.
Tracking Navigation System Based on Photogrammetry Principles
Authors: Zaborowski Tadeusz , Shvartsburg Leonid Efraimovich , Konov Stanislav Gennadyevich
Published: October 2016

An approach to implementation of spatial navigation based on photogrammetry principles is proposed. A prototype of a tracking navigation system implementing the abovementioned approach is developed; experimental research of developed system is conducted.
Spectral Parameters of Straightness Deviation Evaluation
Authors: Glubokov Alexander Vladimirovich , Glubokova Svetlana Vladimirovna , Shulepov Alexey Vileninovich , Ped Sergey Evgenievich
Published: October 2016

Spectral analysis of different profiles obtained during straightness deviation measurement was performed. The several profiles are showed, for which the value of straightness deviation is the same, but its behavior differs greatly. Spectral parameters characterizing the type of straightness deviation are proposed. The automated system based on factors of fuzzy-set theory with implementation in the form of neural network is developed.
Free Vibration Test for Damping Characteristics of Hybrid Polyester Matrix Composite with Carbon Particles
Authors: Karthik K. , Rohith Renish R. , Irfan Ahmed I. , Niruban Projoth T.
Published: October 2016

In this research aims to study the damping characteristics of hybrid polymer composite, which can be used in engineering structures and in many other applications. Hybrid composites are namely Glass fiber and carbon filler reinforced with polyester and epoxy matrix have been prepared by vacuum bag molding fabrication technique. Then the free vibration test were conducted using FFT analyzer with Lab VIEW software. The damping ratio and natural frequency were investigated for fabricated composites. Then through ANSYS, the mode shapes and natural frequencies were determined and the results were compared with experimental results. The damping ratio increases with increased volume fractions of E-glass fibers for both the types of polymer composites. Vibrations are concerned to large structures such as aircraft, as well as small structures such as electronic equipments.
Synthesis and Characterization of Silver Nanoparticles Anchored on Montmorillonite via Chemical Reduction
Authors: Bonga Danica Louise S. , Pinto Ma. Manna Farrel B. , Tayad Mary Fatima T.
Published: October 2016

Montmorillonite clay particles were decorated with silver (Ag) nanoparticles by chemical reduction of Ag nitrate with sodium citrate. X-ray diffraction (XRD) and energy dispersive X-ray spectrometry (EDS) confirmed the presence of metallic Ag on the surface of montmorillonite. The average crystallite size of the Ag nanoparticles obtained from the broadening of the 111 Ag peak ranged at 13-16 nm. On the other hand, the apparent particle sizes obtained from the SEM images were about 79-128 nm, suggesting that the nanoparticles are polycrystalline and possibly agglomerated. The increase in the concentration of reducing agent produced smaller Ag nanoparticles with narrower size distribution. The antibacterial test showed that the Ag nanoparticles, with mean size of 79 nm, adsorbed on montmorillonite were able to inhibit the growth of Staphylococcus aureus (S. aureus) with an antimicrobial index of 0.4.
Element Substitution Effects on Magnetic Properties of Spin-Frustrated Spinel ZnB2O4 (B=Cr and Fe)
Authors: Ono Takumi , Oharu Daichi , Kobayashi Shota , Yamada Hayato , Takita Shota , Maeda Minoru , Takase Kouichi , Takano Yoshiki , Watanabe Tadataka
Published: October 2016

We investigated magnetic properties of spinel oxides Zn (Cr1-xFex)2O4 to study element substitution effects on magnetism of spin-frustrated spinel oxides ZnCr2O4 and ZnFe2O4. The present study revealed that an antiferromagnetic order of ZnCr2O4 (TN ~ 13 K) is suppressed by Fe doping. Zn (Cr1-xFex)2O4 with x = 0.1, 0.5, and 0.7 exhibits spin-glass-like behavior below ~ 10 K. On the other hand, Zn (Cr1-xFex)2O4 with x = 0.3 exhibits the absence of magnetic order or spin-glass-like behavior down to low temperature (3 K), which is probably due to the competition of geometrical and bond frustrations.
Tetrahedrites for Low Cost and Sustainable Thermoelectrics
Authors: Gonçalves António Pereira , Lopes Elsa Branco , Monnier Judith , Alleno Eric , Godart Claude , Montemor Maria de Fátima , Vaney Jean Baptiste , Lenoir Bertrand
Published: October 2016

Sustainable development is the way to ensure the Human progress within the bounds of the ecological possible. In this context thermoelectric systems can play an important role. However, the price of most high-performance thermoelectric devices is high, mainly due to the use of expensive elements, which raised the interest for cheap thermoelectric materials. It is also clear that the production of competitive thermoelectric devices critically depends on other factors, like the manufacturing costs, and that the materials fabrication simplicity, reproducibility, and use of easy scale-up processes will also play a fundamental role.Tetrahedrites, with generic formula Cu10M2Sb4S13 (M = Cu, Mn, Fe, Co, Ni, Zn), are world spread sulfosalt minerals that crystallize in the cubic Cu12Sb4S13-type structure. They are environment friendly materials mainly formed by non-expensive elements. Recently, mineral based and synthetic tetrahedrites were considered as promising thermoelectric materials, with zT ~ 1 at T ~ 700 K. Though, tetrahedrite melts incongruently, the preparation of appropriate tetrahedrite samples usually requiring long-term annealing procedures. Here we present a set of systematic studies on the use of tetrahedrites as low-cost and sustainable thermoelectric materials. The raw material prices evaluation, the feasibility of rapid, scalable, cheap tetrahedrite preparation and their long term stability and resistance to oxidation under working conditions are highlighted.
Synthesis and Characterizations of Titanium Tungstophosphate Nanoparticles for Heavy Metal Ions Removal
Authors: Ghanem Mohamed Ali , Khdary Nezar H. , Almayouf Abdullah M. , Salah Mabrook A.
Published: October 2016

Ionic exchange of multi-components titanium tungstophosphate nanoparticles (TiWP-NPs) were prepared using sol-gel reaction of titanium isoperoxide and tungestophosphoric acid (TPA) in presence of CTAB surfactant. The X-ray, BET and TEM characterizations showed that the nanoparticles exhibit the characteristic structure of titanium tungstophosphate and a BET surface area of 74 ± 3 m2/g was achieved. The TPA has shown an effect on the self-assembly process and maintains the TPA content to minimum would be beneficial for obtaining higher surface area of TiWP nanoparticles. Metal ions adsorption of Cu(II), Pb(II) or Cd(II) using the resulting titanium tungstophosphate nanparticles materials is investigated and up to 95% removal percentage was achieved. Using this method, nanoparticles of ionic exchange titanium tungstophosphate can be synthesized in the form of powder and amenable to mass production.
Phonon Anharmonicity and Thermodynamic Properties of Strongly Correlated Iron Monosilicide
Authors: Povzner Aleksandr A. , Filanovich Anton N. , Nogovitsyna Tatyana A.
Published: October 2016

Two computational approaches – a thermodynamic model based on results of ab initio calculations of the ground state and the self-consistent thermodynamic model have been applied to study thermal and elastic properties of iron monosilicide. It is shown that conventional DFT fails to reproduce experimental data for this strongly correlated compound. In addition, we have performed comparative analysis of anharmonicity of the acoustic and optical phonons in FeSi and their impact on the temperature dependencies of thermodynamic properties of FeSi.
Partial Oxidation in a Dense Phase Sub-Monolayer of Fe-Phthalocyanine on Ag(110)
Authors: Bartolomé E. , Bartolomé Juan , Sedona Francesco , Herrero-Albillos Julia , Lobo Jorge , Piantek Marten , García Luis Miguel , Panighel Mirco , Mugarza Aitor , Sambi Mauro , Bartolomé Fernando
Published: October 2016

In this contribution we report on the structural and magnetic changes along a catalytic cycle of a new dense, “quasi-squared” FePc submonolayer phase (R3) evaporated on Ag(110). X-ray magnetic circular dichroism (XMCD) experiments at the Fe L2,3 edge were performed on four samples: the as-evaporated phase (R3), two differently oxygenated samples (OX1 and OX2) and the annealed phase (ANN). It is concluded that all characterized phases display planar anisotropy, and the values of mseff/nh are one order of magnitude larger than mL/nh. By oxidation, the isotropic moment increases from 7.2 x 10-2 mB/hole to 1.8 x 10-1 mB/hole, which is about a factor of 2 smaller than the increase achieved for the low-density phase.
Magnetic Interaction between d1 [MOR4]− Units of Molybdenum and Tungsten
Authors: García-Monforte M. Ángeles , Alonso Pablo J. , Arauzo Ana B. , Baya Miguel , Luis Fernando , Martín Antonio , Menjón Babil , Rillo Conrado
Published: October 2016

Five-coordinate oxo-derivatives [NBu4][MO(C6F5)4] (1) have been prepared for the heavier Group 6 elements: 1-Mo and 1-W. The magnetic properties of that salts have been studied by a combination of Electron paramagnetic resonance (EPR), calorimetric and magnetochemical techniques, pointing out the existence of weak ferromagnetic interactions. These have been correlated with the arrangement of the magnetic units in the crystal.
Hydride Formation in the TbNi0.4Co0.6-H2 System
Authors: Anikina Elena , Yaropolov Yury , Somenkov Victor , Verbetsky Victor
Published: October 2016

The hydrogenation of TbNi0.4Co0.6 was studied by means of neutron diffraction and calorimetric method with use of the differential heat-conducting Tian-Calvet type calorimeter. It was determined that TbNi0.4Co0.6H3.8 crystallized in orthorhombic CrB-type structure (S.G. Cmcm). The hydride formation is accompanied with strong lattice expansion. In the structure TbNi0.4Co0.6D3.4 deuterium atoms occupy tetrahedral 8f-intersices, trigonal bipyramidal 4c-interstices and octahedral 4b-interstices. Dependence of the differential molar enthalpy of absorption (ΔHabs) vs. the hydrogen concentration in the metallic matrix was obtained at 50°C. It was ascertained that in the range of 0<X<2.0 (X=H/ TbNi0.4Co0.6) ΔHabs =-102.0±2.3 kJ mol-1H2. The value of the integral enthalpy of hydrogen absorption by TbNi0.4Co0.6 equals -99.5kJ mol-1H2 for the composition TbNi0.4Co0.6H3.8.
Investigation of Mechanochemical Synthesized Tungsten Silicides from WO3, SiO2 and Mg Blends
Authors: Ovalı Didem , Ovecoglu Mustafa Lutfi
Published: October 2016

In this study, tungsten silicide powders mechanochemically synthesized using WO3-SiO2-Mg powder blends. Stoichiometric proportions and excess amounts of initial powders were used to indicate the effects of final composition of synthesized tungsten silicide powders. Since the initial powder compositions affect the reaction times, all compositions were mechanically alloyed for 1 hour. In addition, thermodynamic calculations of all compositions were theoretically conducted. The dominant phases are WSi2 and MgO for all mechanically alloyed powders. Results show that the excess amount additions of initial powders directly effects the amount and formation of resultant phases in the synthesized powder compositions.
Microstructural Characterization of New Super-Ferritic-Martensitic Stainless Steel
Authors: Souto Maior Tavares Sérgio , da Cunha Rocha Adriana , da Silva Manoel Ribeiro , Silva de Oliveira Carlos Augusto , Pereira Carneiro da Cunha Rachel
Published: October 2016

The demand for high strength materials with improved corrosion resistance boosted the development of supermartensitic steels from conventional martensitic stainless steels The first alloys were designed with 11-13%Cr, extra-low carbon and nickel addition. More recently, experimental alloys with higher Cr (15-17%) and other ferritizing elements (Mo, W, Nb,…) were developed with the aim of obtain higher corrosion resistance in high chloride environments. In this work, the microstructure features of a new 17%Cr stainless steel were investigated.
Bifid Mandibular Canal: A Rare or Underestimated Entity?
Authors: Nasseh Ibrahim , Aoun Georges
Published: October 2016

One of the rare anatomical variations that can be of significant importance for the dentist is the bifid mandibular canal. Many complications can occur from this condition such as failure of anesthesia when performing inferior alveolar nerve block, difficulties during the surgical extraction of the third mandibular molar, and during implants placement. Therefore, good knowledge of this condition is essential. In this report, we describe the radiographic finding of a unilateral bifid mandibular canal.
A review of Sciurus Group studies on the red squirrel (Sciurus vulgaris): presence, population density and colour phases in Lombardy (Italy)
Authors: Biancardi Carlo M. , Gnoli Claudio G.
Published: October 2016

During the nineties of the last Century, under the inspiration of Luigi Cagnolaro, it had been founded a “Sciurus group”, within the Research Centres of the Società Italiana di Scienze Naturali. Aim of the group was to start a campaign of researches on red squirrel populations in Lombardy, Italy promoting field master thesis on various topics: colour phases and indirect estimations of population densities. The researches were carried out during 10 years in 5 study areas. An investigation and census with questionnaires were started in parallel, with the collaboration of Forest Guards (CFS), Ecological Guards (GEV) and students of biological and natural sciences. The results were published in Italian or exposed in national and international congresses. This review has the purpose to show and critically discuss the overall results, and make them available to a broader audience. The dark colour phase, in the red squirrel, resulted associated to elevation and conifer woodlands, according to the thermoregulation theory, which consider the dark fur thicker and more suitable in cold environments. Squirrel population densities are subject to periodical fluctuations, in conifer woodlands, due to cones availability. Cone crops are subject to cycle with years of great production followed by years of lean. The recorded squirrel densities are middle-lows, but in line with data from similar environments.
Odonata next-door: an updated check-list of two parks in the Northern Milan outskirt (Lombardy, Italy)
Authors: Foglini Claudio
Published: October 2016

Odonata are usually regarded as bioindicators and model organisms in many studies and are subjected to increasing threats worldwide. Such insects populate freshwater ecosystems at both natural and urban landscapes and they are also well-known by common people. This work is aimed at summarizing and updating the current knowledge concerning Odonata species inhabiting two parks located at the northern boundary of the Milan outskirts (Italy, Lombardy). Occupancy status for odonate species were obtained merging the field data of surveys conducted during 2014 and 2015 with spare information from specialistic websites and forums, grey literature, and pictures collected at the same sites by occasional observers. The total number of species found in both parks showed an increase of species richness when compared with two previous studies. Morevoer, Odonata communities of the two parks showed a common chorological composition and similarity in the species assemblages. This work had also a positive impact about the perception of urban biodiversity: some of the untrained observers, who shared their pictures for species identification, rapidly acquired sufficient knowledge to easily recognize the most common species present in both parks.
Stump evolution after great saphenous vein stripping with high ligation
Authors: Casoni Paolo , Lefebvre-Vilardebo Marc , Villa Fabio , Corona Piero
Published: October 2016

The aim of the present observational study is to show the evolution of great saphenous vein (GSV) stump in two different periods of follow up. From 2001 to 2009, 500 legs with GSV insufficiency and terminal valve reflux, operated on with stripping by invagination without crossectomy, were followed. Doppler were performed at 1 month (early) and then mid-term (2-year follow-up). The hemodynamic examination of residual stumps showed 4 different types: S1) draining and competent terminal valve; S2) thrombosis and fibrosis; S3) turbulence under Valsalva maneuver and normal antegrade flow at rest; S4) turbulence with reflux at rest: refluxing terminal valve. Early: the most common finding was S1 (64%), then S2 (18%), S3 (12%) and S4 (6%); S1-S3 patterns were considered as good evolution (94%), whereas S4 were considered recurrence. Mid-term phase: the most common finding was again S1 (67%), then S3 (15%), S4 (10%) and S2 (8%). S1 evolution: out of 319 legs in S1 group at early phase, 294 (92%) remained still in S1 at mid-term follow up; 25 (8%) worsen to S3. S2 evolution: out of 92 legs in S2 at early phase, 42 (46%) improved to S1, 40 (43%) did not change pattern across time and 10 legs (11%) worsen to S4. S3 evolution: almost the legs in S3 (51, 86%) remained unchanged at mid-term, whereas 8 (14%) worsen to S4. S4 evolution: all the patients in S4 class at early follow up were still in the same class at mid-term. The evolution of GSV stump can be classified in 4 different patterns, where only S4 should be considered failure.
Determinants of lymph node status in women with breast cancer
Authors: Chakraborty Abhijit , Bose Chinmoy Kumar , Basak Jayasri , Sen Aditya Narayan , Mishra Raghwendra , Mukhopadhyay Ashis
Published: October 2016

Background & objectives:

Number of metastatic lymph nodes has a strong prognostic value in the course of breast cancer treatment, morbidity and mortality. This study was undertaken to determine the association between axillary lymph node metastasis and several variables such as age, tumour size, grade, lymphovascular invasion, oestrogen and progesterone receptor expression and HER2/neu status in patients with breast cancer.

Methods:

In this study 426 (with complete information on study variables) patients with breast cancer on treatment during March 2010 to December 2013, were analyzed. TNM (tumour node matastasis) staging was evaluated. The histological grading of tumours was done according to modified Bloom-Richardson Grading System. The immunophenotype of the tumour was determined as the expression of oestrogen (ER) and progesterone (PR) receptors and HER2/neu status. Univariate and multivariate analyses were carried out to determine the independent predictors of metastatic lymph node.

Results:

Among the studied patients, 44.36 per cent (189 of 426) of the patients had nodal metastases. Tumour histology, tumour grade, size and lympho-vascular invasion were related with node positivity. On univariate analysis, age, menopause, hormone receptor status did not relate with the node metastasis. Age, tumour grade, tumour size, lympho-vascular invasion and HER2/neu expression was likely to be associated with the number of lymph node metastasis.

Interpretation & conclusions:

The lymph node status was associated with clinical stage, tumour grade, tumour histology and HER2/neu status. These factors may be used for better management of such patients.
Epigenetic regulation of APC in the molecular pathogenesis of gallbladder cancer
Authors: Tekcham Dinesh Singh , Poojary Satish S. , Bhunia Shushruta , Barbhuiya Mustafa Ahmed , Gupta Sanjeev , Shrivastav Braj Raj , Tiwari Pramod Kumar
Published: October 2016

Background & objectives:

Loss of function of adenomatous polyposis coli (APC) has been reported in cancer. The two promoters of APC, 1A and 1B also have roles in cancer. But, the epigenetic role of APC promoters is not yet clear in gallbladder cancer (GBC) and gallstone diseases (GSD). We undertook this study to determine the epigenetic role of APC in GBC and GSD.

Methods:

Methylation-specific (MS)-PCR was used to analyze the methylation of APC gene. The expression of APC gene was studied by semi-quantitative PCR, real-time PCR and immunohistochemistry (IHC) in GBC, GSD and adjacent normal tissues.

Results:

Of the two promoters, APC 1A promoter was found methylated in 96 per cent GBC (P=0.0155) and 80 per cent GSD (P=0.015). Exon 1 was downregulated in grade II (P=0.002) and grade III (P=0.0001) of GBC, while exon 2 was normally expressed. Scoring analysis of IHC revealed 0 or negativity in 34.48 per cent (P=0.057) and 1+ in 24.14 per cent (P=0.005) GBC cases suggesting loss of APC expression.

Interpretation & conclusions:

The present findings indicate epigenetic silencing of APC in advanced GBC. The methylation pattern, followed by expression analysis of APC may be suggested for diagnostic, prognostic and therapeutic purposes in GBC in future.
PI3K/Akt/mTOR signaling & its regulator tumour suppressor genes PTEN & LKB1 in human uterine leiomyomas
Authors: Makker Annu , Goel Madhu Mati , Mahdi Abbas Ali , Bhatia Vikram , Das Vinita , Agarwal Anjoo , Pandey Amita
Published: October 2016

Background & objectives:

Despite their high occurrence and associated significant level of morbidity manifesting as spectrum of clinical symptoms, the pathogenesis of uterine leiomyomas (ULs) remains unclear. We investigated expression profile of tumour suppressor genes PTEN (phosphatase and tensin homolog deleted on chromosome ten) and LKB1 (liver kinase B1), and key signaling components of P13K (phosphatidylinositol 3-kinase)/Akt (protein kinase B)/mTOR (mammalian target of rapamycin) pathway in leiomyomas and adjacent normal myometrium in women of reproductive age, to explore the possibility of targeting this pathway for future therapeutic implications.

Methods:

Real time PCR (qPCR) was used to quantify relative gene expression levels of PTEN, Akt1, Akt2, mTOR, LKB1 and VEGFA (vascular endothelial growth factor A) in leiomyoma as compared to adjacent normal myometrium. Immunohistochemistry was subsequently performed to analyze expression of PTEN, phospho-Akt, phospho-mTOR, phospho-S6, LKB1 and VEGFA in leiomyoma and adjacent normal myometrium.

Results:

Significant upregulation of PTEN (2.52 fold; P=0.03) and LKB1 (3.93 fold; P=0.01), and downregulation of VEGFA (2.95 fold; P=0.01) genes were observed in leiomyoma as compared to normal myometrium. Transcript levels of Akt1, Akt2 and mTOR did not vary significantly between leiomyoma and myometrium. An increased immunoexpression of PTEN (P=0.015) and LKB1 (P<0.001) and decreased expression of VEGFA (P=0.01) was observed in leiomyoma as compared to myometrium. Immunostaining for activated (phosphorylated) Akt, mTOR and S6 was absent or low in majority of leiomyoma and myometrium.

Interpretation & conclusions:

Upregulation of PTEN and LKB1 in concert with negative or low levels of activated Akt, mTOR and S6 indicates that PI3K/Akt/mTOR pathway may not play a significant role in pathogenesis of leiomyoma.
Spectrum of AIDS defining & non-AIDS defining malignancies in north India
Authors: Sachdeva Ravinder Kaur , Sharma Aman , Singh Surjit , Varma Subhash
Published: October 2016

Background & objectives:

There is scarcity of data on the frequency of malignancies in HIV infected individuals from India. The objective of this study was to determine the type and frequency of malignancies in HIV infected individuals attending a tertiary care hospital in north India.

Methods:

The study design included retrospective analysis of data of all HIV infected individuals registered in the Immunodeficiency clinic from December 2009 to December 2011 and a prospective analysis of HIV infected individuals registered from January 2012 to April 2013. The clinical details and treatment outcomes of all individuals diagnosed to have AIDS defining and non-AIDS defining malignancies were recorded.

Results:

Records of 2880 HIV infected individuals were reviewed. Thirty one (19 males, 12 females) individuals were diagnosed to have malignancy. AIDS defining malignancy was found in the form of non-Hodgkin's lymphoma in 12 individuals and cervical cancer in six women. Non-AIDS defining malignancies included Hodgkin's lymphoma (n=2); and chronic myelogenous leukaemia, carcinoma base of tongue, carcinoma larynx, carcinoma bronchus, sinonasal carcinoma, ovarian carcinoma, anal carcinoma, carcinoma urinary bladder, pleomorphic sarcoma, parathyroid adenoma, and renal cell carcinoma in one individual each. Mean CD4+cell count prior to ART initiation was 250 ± 195.6 (median: 187; range, 22-805) cells/μl and at the time of diagnosis of malignancy was 272 ± 202 (median: 202; range, 15-959) cells/μl. The mean CD4+ count of individuals with AIDS defining malignancy was significantly lower when compared with non-AIDS defining malignancy (P<0.001). Fourteen individuals were alive and on regular follow up, 15 had died and two cases were lost to follow up.

Interpretation & conclusions:

The frequency of malignancies in HIV infected patients at our centre was 1 per cent, with non-Hodgkin's lymphoma being the commonest. Further studies need to be done to document similar data from different parts of the country.