bluuebunny/crossref_metadata_2025 huggingface dataset:
The Impact of Perceived Subgroup Formation on Transactive Memory Systems and Performance in Distributed Teams
Authors: Shen Yide , Gallivan Michael J. , Tang Xinlin
Published: January 2016

With distributed teams becoming increasingly common in organizations, improving their performance is a critical challenge for both practitioners and researchers. This research examines how group members' perception of subgroup formation affects team performance in fully distributed teams. The authors propose that individual members' perception about the presence of subgroups within the team has a negative effect on team performance, which manifests itself through decreases in a team's transactive memory system (TMS). Using data from 154 members of 41 fully distributed teams (where no group members were colocated), the authors found that members' perceptions of the existence of subgroups impair the team's TMS and its overall performance. They found these effects to be statistically significant. In addition, decreases in a group's TMS partially mediate the effect of perceived subgroup formation on team performance. The authors discuss the implications of their findings for managerial action, as well as for researchers, and they propose directions for future research.
Modularity in Health and Social Services
Authors: Vähätalo Mervi
Published: January 2016

Modularity is a common concept in manufacturing. Recently, it has been applied to service production. Higher expectations of efficiency and demand-based services but also the availability of multiple providers gives reason to study its potential relevance to health and social services. A systematic literature review helped to clarify the content of the relevant concepts when modularity is applied in practice. Multidisciplinary databases were consulted in order to find out how the concept is perceived and used in this context. The analysis of the material was based on the theoretical literature on modularity. The results are revealed further in the article.
Experimental Determination of the Crack Tip Stress Intensity Factor in Integrally Stiffened Panels
Authors: Chaves Carlos E. , de Assunção Caio Magno
Published: January 2016

Integral structures offer large benefits in terms of manufacturing cost, but suffer from a lower degree of fail safety when compared to built-up structures. In order to achieve an improvement on the fatigue crack propagation (FCP), crack containment features (also known as crenellations) have been used on these structures. The source of the FCP improvement is the stress intensity factor (K) modification due to the geometry change. In the current study, an analysis about means of estimating K from the experimental information, and also to verify the K behavior while the crack propagates was performed. The study tested two AA 7475 panels, one with crenellations and another without. As the crack propagates, the K values were estimated in two forms, based on the crack propagation rate and by using a digital image correlation (DIC) system, coupled with strain gages. Based on DIC system, it was possible to evaluate the K estimation, the singularity dominated zone size and the K increase, as long as the crack propagated, for both test specimens. A comparison between the two methods was also made, and finally the use of a DIC system as a tool for estimating the K parameter was discussed.
Numerical and Experimental Analysis of Adhesively Bonded Stiffened Panels Subjected to In-Plane Compression Loading
Authors: Rossini Mayara Bortolotti , Donadon Maurício Vicente
Published: January 2016

This paper presents a numerical and experimental study on the pre and post-buckling behavior of adhesively bonded stiffened panels subjected to in-plane compression loading. An experimental programme was carried out to characterize the buckling load, buckling modes and collapse loads. The mechanical tests were performed in the Aerospace Structures Laboratory at ITA. The structural performance of the bonded stiffened panels in terms of buckling and collapse loads was compared to conventional riveted stiffened panels. Finite element models accounting for material, geometrical nonlinearities as well as progressive failure in the bonded interface were developed and validated experimentally. A good agreement between numerical and experimental results was found for buckling and collapse loads through number of semi-waves and measured strains. The experimental and numerical results indicate a superior performance in buckling load and failure load of the bonded stiffened panels over the riveted panels. Both numerical and experimental results showed that the bonded stiffened panels had over 19% higher failure load in comparison with the riveted panels.
Industrial Applications of Hard and Superhard Nanocomposite Coatings on Tools for Machining, Forming, Stamping and Injection Molding
Authors: Veprek Stan , Holubar Pavel , Veprek-Heijman Maritza
Published: January 2016

The design and application of hard and superhard (H ≥ 40 GPa) coatings and their properties are discussed with the focus on superhard nanocomposites. The main part of the article deals with examples of industrial applications of hard and superhard nanocomposite coatings as wear protection coatings on tools for machining, forming, stamping, injection molding and the like. The advantages and possibilities as well as the limitations of the different types of coatings with emphasis on the nanocomposites are discussed and illustrated by a number of examples from aerospace and other branches of industry.
Experimental Investigation of Processing Welding Parameters for PPS/Carbon Fiber Laminates for Aeronautical Applications
Authors: de Souza Samia Danuta Brejão , Abrahão Ana Beatriz R.M. , Costa Michelle Leali , Marlet José Maria F. , Hein Luis Rogerio O. , Botelho Edson C.
Published: January 2016

An experimental investigation of the resistance welding of PPS/carbon fiber is presented in this manuscript. Currently, one of the main problems of the structural polymer composites consists in its effective integration of the components. The electrical resistance welding has been considered as one of the promising techniques for bonding composites, because it is a quick process with easy surface preparation. To improve the process to welding poly-(phenylene sulfide) (PPS) reinforced with carbon fiber laminates, it was used a full factorial design (23). Considering the factors pressure, electrical current and time, the more appropriate conditions for welding were evaluated based on a criterion of maximum lap shear strength, according to ASTM D1002-10. A comparison between welded and non-welded specimens in terms of analysis dynamic mechanical (DMA), thermomechanical analysis (TMA) and vibration tests was performed. It was demonstrated that large-scale DMA presented a similar results but according to TMA and vibration test were observed that welded specimens presented different results when compared to non-welded laminates, due probably to the presence of metallic heating element.
Carbon Fiber Surface Modification by Plasma Treatment for Interface Adhesion Improvements of Aerospace Composites
Authors: Santos Alberto Lima , Botelho Edson Cocchieri , Kostov Konstantin Georgiev , Ueda Mario , da Silva Leide Lili G.
Published: January 2016

This paper is focused on the processing of thermoplastic composite materials obtained from carbon fibers (CFs) treated by plasma assisted techniques. The treatments employed in this work were the Dielectric Barrier Discharge (DBD), which is done at atmospheric pressure, involving lower energies and the Plasma Immersion Ion Implantation (PIII), which is performed at low pressure, involving higher energies. After the treatments, samples characterizations were performed to determine which treatment is most effective to get better physico-chemical CF surface properties. The techniques employed in this work in order to evaluate the surface treatment were: scanning electron microscopy (SEM); atomic force microscopy (AFM) Raman spectroscopy and x-ray photoelectron spectroscopy (XPS). Treated and untreated CFs/Polyphenylene sulfide (PPS) composites were processed by hot-compression molding technique. These composites were evaluated by interlaminar shear tests (ILSS). After analyzing the results, it was found that the treatments increased the CF roughness and caused slight changes in the CF structure. In addition, there was an increase in the shear strength of the composites obtained from treated fibers by both plasma processes. In conclusion, DBD and PIII treatments are effective tools for improving adhesion between CF and the polymeric matrix.
Recyclability and Performance Stability of Corrosion Inhibition Improved Amine-Free Water-Soluble Cutting Coolant
Authors: Yamaguchi Kenji , Fujita Tsuyoshi , Kondo Yasuo , Sakamoto Satoshi , Tsukano Subaru , Yamaguchi Mitsugu
Published: January 2016

The concern for environmental problems has been increasing rapidly in recent years. Water-soluble coolants are widely used in machining processes. To reduce management costs and the environmental load of water-soluble coolants, the authors studied a recycling system for water-soluble coolants. With this recycling system, water is extracted from a waste coolant by chemical or biochemical treatment; the recovered water is re-utilized as a diluent for a new coolant. Coolant recyclability depends on the coolant type. Most water-soluble coolants contain alkanolamines for corrosion inhibition and maintenance of putrefaction prevention. However, alkanolamines are difficult to eliminate from water-soluble coolants by chemical and physical waste treatment processes. Some amine-free, water-soluble coolants have been developed and are commercially available. The reduction of environmental load in the treatment of waste coolants is anticipated for amine-free coolants. We applied the recycling process to a commercially available amine-free, water-soluble coolant. The amine-free coolant showed good recyclability and lubricating performance. However, the corrosion inhibition performance of the coolant was inadequate for use in general machining. Recently, our cooperative company developed a prototype amine-free, water-soluble coolant with improved corrosion inhibition. In this study, we experimentally examined the recyclability and performance stability of this newly developed coolant. The experimental results showed that the new amine-free coolant has good corrosion inhibition equivalent to conventional amine-containing coolants. In addition, the recyclability, stability, and cooling and lubricating performance of the coolant are equal to conventional amine-free coolants. The amine-free, water-soluble coolant with improved corrosion inhibition has the advantage that it can be used in the recycling system for water-soluble coolants.
Influence of Pulsed Magnetic Treatment on Wear of Carbide Micro-end-Mill
Authors: Liang Zhi Qiang , Ma Li Ping , Wang Xi Bin , Zhao Wen Xiang , Zhou Tian Feng , Yan Pei , Jiao Li
Published: January 2016

This study is carried out to investigate the influence of pulsed magnetic treatment on wear of carbide micro-end-mill. To analyze the friction behavior of micro-end-mill with workpiece, the special micro-end-mill with a chisel is fabricated and used in micro-milling experiments. A paramagnetic material aluminum alloy is employed as workpiece material. The experimental results indicated 17% and 27 % reductions in maximum minor flank wear width and chisel edge wear area of micro-end-mill after pulsed magnetic treatment, respectively. However, the surface roughness and morphology of machined aluminum alloy have no obvious changes with or without pulsed magnetic treatment. Consequently, the reduction of tool wear during milling aluminum alloy can be mainly attributed to the improvement of mechanical properties of carbide tool materials after pulsed magnetic treatment.
Effect of Citric Acid in Chemical Mechanical Polishing (CMP) for Lithium Tantalate (LiTaO3) Wafer
Authors: Lee Hyun Seop
Published: January 2016

Lithium tantalate (LiTaO3) has piezoelectric, electro-optical and nonlinear optical characteristics, and a wide transparency range going from ultraviolet to infrared. It is desirable that LiTaO3 wafer was a smooth surface in order to function with good quality. Chemical mechanical polishing (CMP) has been used to planarize integrated circuits (ICs) or obtain a high surface quality of the substrates. This paper investigates the effect of citric acid as an additive in the slurry for LiTaO3 CMP. The roughness of the wafers was measured by an atomic force microscopy (AFM, XE-100) after polishing. The slurry, which contains citric acid as an additive, has a higher material removal rate and friction force than a slurry without an additive. After polishing, the surface roughness of the LiTaO3 wafer can be reduced down to 1.7Å of Ra.
Numerical Analysis of Slurry Flow and Contact Pressure in CMP Considering the Effects of Retaining Ring
Authors: Li Chao , Zhou Ping , Jin Zhu Ji , Zhang Bi , Shi Shuang Ji
Published: January 2016

Retaining ring which keeps the wafer in place is an essential component in chemical mechanical polishing. Meanwhile, it helps to reduce the edge exclusion region where the material removal rate deviates significantly from that of the central region of the wafer. However, it may increase the slurry flow resistance and hence decrease the slurry flow rate. For properly designing a retaining ring of reasonable structure, the effects of retaining ring on slurry flow and contact pressure distribution in CMP process are analyzed by the mixed elastohydrodynamic lubrication model. It is found that the slurry flow is sensitive to the protrusion height of retaining ring used in the first generation carrier. The same as the first generation carrier, the slurry flow is obviously reduced with increasing pressure acting on the retaining ring in the second generation carrier. In addition, the floating retaining ring used in the second generation CMP carrier has better performance and is more controllable than the fixed retaining ring used in the first generation CMP carrier.
Fundamental Investigation of Ultrasonic Assisted Surface Grinding of Inconel 718
Authors: Li Si Si , Wu Yong Bo , Nomura Mitsuyoshi
Published: January 2016

Inconel 718 has high yield strength, corrosion resistance, heat resistance and fatigue resistance, and possesses a lower thermal conductivity, leading to high grinding force and heavy wheel damage in grinding of this material. Against these problems, ultrasonic assisted grinding (UAG) can be the potential candidate for high efficiency processing of Inconel 718. The current work is, hence, to clarify the fundamental UAG characteristics of Inconel 718 by experimentally investigating the effect of vibration amplitude on grinding force, actual material removal and work-surface roughness under different process parameters such as the wheel rotational speed, wheel depth of cut and vibration amplitude. Summarizing the obtained results revealed that the grinding forces and the actual material removal in UAG are significantly smaller and larger, respectively, than those in conventional grinding. It is also found that ultrasonic vibration can improve the work-surface finish even at deep wheel depth of cut.
Effect of Cutting Speed on Ultrasonically Added Turning in Soft Magnetic Stainless Steel
Authors: Hara Keisuke , Isobe Hiromi
Published: January 2016

Ultrasonic cutting is a technique that can improve machinability such as fine surface, reduce tool worn out and etc. To improve processing speed of ultrasonic cutting is difficult due to the effects of tool oscillation are invalidated when cutting speed exceeds maximum tool oscillating velocity. In this study, high speed principal direction ultrasonic turning experiments for soft magnetic stainless steel were carried out to investigate effects of cutting speed and products quality. Surface roughness, chip worn out and built up edge were investigated in this study. In case of ultrasonic turning, tool worn out and built up edge generation were reduced compare with ordinary turning. High speed ultrasonic cutting can improve cutting performances in phase of turned surface quality, cutting force and processing speed.
Controllability Study of Single-Crystal Diamond Cutting Tool Focus Ion Beam Milling with Different Beam Current and Tilting Angle
Authors: Baek Seung Yub , Choi Woong Kirl , Choi Young Jae , Lee Eun Sang
Published: January 2016

Micro/nanoscale diamond cutting tools used in ultra-precision machining can be fabricated by precision grinding, but it is hard to fabricate a tool with a nanometric cutting edge and complex configurations. High-precision geometry accuracy and special shapes for microcutting tools with sharp edges can be achieved by focused ion beam (FIB) milling. However, in the FIB milling process, the surface properties of the substrate (such as a diamond substrate) are affected by the amorphous damage layer caused by the FIB gallium ion collision and implantation and these influence the diamond cutting tool edge sharpness and increase the processing procedure. In this study, to reduce the diamond cutting tool edge sharpness and processing procedure, FIB milling beam current and tilting angle characteristics of single-crystal diamond were investigated, along with method for decreasing the FIB-induced damage on diamond tools by platinum (Pt) coating on the diamond substrate. Experimental results revealed that optimize beam current, tilting angle and platinum (Pt) coating could lead to relatively few processing procedure and sharp cutting tool edge. The obtained results are an endeavor to enhance the controllability of the diamond cutting tool FIB milling.
Influence of Components on the Rheological Property of Shear Thickening Polishing Slurry
Authors: Lyu Bing Hai , Dai Wei Tao , Weng Hai Zhou , Li Min , Deng Qian Fa , Yuan Ju Long
Published: January 2016

Shear thickening polishing (STP) method was newly developed to achieve high efficient and high quality finishing of complex curved surface. The shear thickening fluid based slurry is one of the key factors in STP process. Viscosity of different shear thickening polishing slurry (STPS) was tested by rheometer in this study. The influences of dispersed particle size and concentration, abrasive material, abrasive particle size and concentration on the rheological property of STPS were analyzed. The results show that smaller dispersed particle (5.5 or 13μm in this study) and relative higher concentration (50-55 wt.%) are better for shear thickening effect of the base fluid. The viscosity of base fluid increases from 0.15-0.3 Pa·s to 0.8-1.1 Pa·s under high shear rate. The participation of Al2O3 and diamond abrasive changes the rheological property little, and the viscosity of STPS reaches the highest value 1.8 Pa·s at shear rate 300 s-1. But SiC abrasive obviously destroys the shear thickening effect. SPTS with different Al2O3 abrasive concentration in this study presents almost same viscosity curve. It is inferred that the number of the abrasive particle but not the weight ratio plays the role to effect the rheological property of STPS.
Experimental Research on Flexible Polishing by Compound Diamond Powder
Authors: Xiang Rui Le , Zhou Tian Feng , Liang Zhi Qiang , Wang Xi Bin
Published: January 2016

Surface polishing is an important technique in the precision/ultra-precision process, especially in the optical industry. This paper introduces a new polishing method named Flexible Polishing by Compound Diamond Powder (FPCDP), in which the polishing abrasive grains are made of a kind of compound particles with flexible base and abrasive diamond powder. In FPCDP process, the compound abrasive grains are jetted onto the workpiece surface with an accelerated speed at an incident angle, and the micro irregularities on the workpiece surface are removed during the scratching, rolling and ploughing by the compound abrasive grains. The mechanism of polishing process is analyzed and the machining condition is optimized by experiments, which shows that FPCDP is an efficient method to improve the glass surface roughness.
Ultraprecision Machining of Si3N4 Ceramics with Shear-Thickening Polishing
Authors: Li Min , Lyu Bing Hai , Yuan Ju Long , Zhao Ping
Published: January 2016

Shear-thickening polishing (STP) technology was used on ultraprecision machining of Si3N4 ceramics. The STP slurry with diamond abrasives was prepared for STP process and its rheological property was studied. The polishing performance of Si3N4 ceramics with STP was analyzed. Results show that STP slurry with diamond abrasives exhibits non-Newtonian power-law fluid characteristics with shear-thickening effect. As using STP slurry with abrasive particle size of 0.2 μm, the material removal rate changed from 4.22 to 4.05 μm/h after 60 mins ́ polishing; and decreased from 3.88 to 3.75 μm/h after 120 mins ́ polishing. The average surface roughness reduced from Ra 107.2 to Ra 6.5 nm after 120 mins ́ polishing.
Measurement of the Temperature Distribution at the Tool-Chip Interface by Using a Cutting Tool with Seven Pairs of Built-In Micro Cu/Ni Thermocouples
Authors: Shinozuka Jun , binti Jaharadak Habibah
Published: January 2016

Knowing temperatures at the tool-chip interface is extremely important to optimize the machining condition and to improve the machining performance, furthermore to design high performance materials. In order to grasp the temperature distribution at the tool-chip interface, this study has devised an indexable insert with seven pairs of built-in micro Cu/Ni thermocouples on the rake face near the cutting edge. This paper shows the performance of the indexable insert with built-in micro thermocouples developed. The thickness of each element of the micro thermocouple is approximately 15 μm. The result of unsteady heat conduction analysis employing FEM shows that the temperature difference by installing the micro thermocouples is less than 10 K or 1.2 %. The temperature measurement experiments by cutting of aluminum alloy were carried out by changing the cutting speed. The results provided the evidence that the temperature distribution at the tool-chip interface can be grasped with the indexable insert with built-in micro thermocouples developed.
Fabrication of Computer Generated Hologram for Aspheric Surface Measurement
Authors: Zhang Zhi Yu , Yang Xu , Zheng Li  Gong
Published: January 2016

High-precision aspheric surfaces are generally measured using interferometer with a computer-generated holograms (CGH), which has a wavy line pattern fabricated onto a glass substrate. CGH patterns are generally made using lithographic techniques that was developed for semiconductor industry. Patterns can be subsequently etched into glass substrate using reactive ion or chemical etching. The accuracy of the drawn pattern on a CGH decides the accuracy of the measurement. Draw pattern error mainly includes the line-width deviation and its position error. In this paper, the influences of defocus of drawing laser and the wet-etching processes on the line-width were firstly investigated. On the other hand, the position error under different line-width was obtained by analyzing the relationship of line-width error and the position error. Based on the above-obtained results, a CGH having a diameter of 80 mm and the minimum line-width of 1.8 μm was successfully fabricated. Testing results showed that the wavefront error was only 3.79 nm, significantly higher than the commercial-available ones. The fabricated CGH is expected to use in the high-precision measurement of asphercal surfaces.
Development of In-Process Monitoring System for Grinding Wheel Surface Temperature and Grinding State
Authors: Fukuhara Yoshiya , Suzuki Shuhei , Sasahara Hiroyuki
Published: January 2016

Grinding is a machining technology for plane surfaces and cylindrical surfaces in general. In comparison with cutting, higher accuracy can be provided and it is easier to manufacture high-hardness materials using grinding. However, the grinding wheel surface state changes during grinding, and grazing, clogging and shedding may then lead to problems. As these problems degrade the accuracy and productivity of grinding and the surface integrity of the work material, it is important to select an appropriate grinding condition to avoid the problems. In this study, a novel in-process system for monitoring the grinding wheel surface temperature and grinding state in real time, was proposed. A thermocouple is embedded in the grinding wheel in the developed system. The measured temperature data are transmitted to the external terminal equipment by a wireless transmitter built into the tool shank. Grinding wheel surface temperature was measured on four kinds of grinding wheels using the developed system. As a result, the grinding wheel surface temperature was measured successfully. In addition, it was clarified that the temperature transition largely depends on the grinding state.
Loop Stiffness of Grinding Machine Developed for 450 mm Silicon Wafers
Authors: Kusuyama Jumpei , Iwahashi Shintaro , Kitajima Takayuki , Ogasawara Nagahisa , Yui Akinori , Saito Hirotsugu , Slocum Alexander H.
Published: January 2016

Increasing the wafer diameter from φ300 mm to φ450 mm is required to enhance semiconductor devices productivity. A high-stiffness rotary grinding machine equipped with water hydrostatic bearings was developed for a φ450 mm silicon wafer. The grinding machine has an upper structure consisting of a wheel spindle system and a lower structure consisting of a rotary worktable system. The spindle shaft creates both rotary and axial feeding motion. The upper and lower structures are clamped together rigidly by three kinematic couplings. A higher loop stiffness is required for the grinding machine because grinding the larger wafer requires a higher grinding force. This paper investigates the loop stiffness of the developed wafer grinding machine.
Characteristics in Grinding of YVO4 with a Resin Bond Diamond Wheel
Authors: Zhang Mei Qin , Yu Yi Qing , Huang Guo Qin , Xu Xi Peng
Published: January 2016

An investigation was undertaken to explore the grinding characteristics in grinding of yttrium vanadata (YVO4) crystal by using a resin diamond wheel. The grinding forces and surface roughness were measured and the morphological features of ground workpiece surfaces were examined. The results indicate that the depth of cut is the leading factor in affecting grinding forces whereas the surface roughness is mainly governed by the grinding speed. The material removal mechanism was found to be dominated by brittle fracture mode at conventional grinding speeds, and gradually transfer to ductile flow mode under higher grinding speeds, which is greatly related to the maximum undeformed chip thickness.
Improvement of Surface Roughness with Micro-Axial Vibration of Spindle by Pressure Pulsation of Grinding Fluid Supplied through inside of Wheel
Authors: Nomura Kosaku , Takeuchi Naoya , Kusakabe Atsushi , Chino Masahisa , Sasahara Hiroyuki
Published: January 2016

In grinding, the moving trajectories of abrasive grains are almost straight to the motion of the rotation and feed of the grinding wheel, so that grinding marks are formed continuously. As a result, surface roughness is dependent on grain size and organization of the grinding wheel. If the trajectory of the abrasive grain is wavy, the peak lines of the grinding marks will be partially removed by following the abrasive grain. This improves surface roughness. The objective of this study is to develop a mechanism to give axial vibration to the grinding wheel by the pulsation of the plunger pump, and thus to improve the surface roughness of the machined surface.
Internally Cooled Toric Tools for Grinding of Medical Ceramics
Authors: Denkena Berend , Grove Thilo , Tatzig Lukas
Published: January 2016

The application of ceramics for knee prostheses promises a significant extension of the lifespan compared to conventional metal implants due to their outstanding mechanical and tribological properties. Nevertheless, grinding operations at the bone-faced surface of ceramic knee implants are limited. These limitations arise from an unfavorable accessibility of coolant lubricant. Caused by undercuts and concave surfaces the external coolant jet is deflected and does not reach the contact zone. In this paper, a prototype of a toric grinding tool with internal coolant supply is introduced. This innovative tool design enables a reliable and economic grinding process of the bone-faced surface of ceramic knee implants.
Process Automation in Computer Controlled Polishing
Authors: Walker David , Yu Guo Yu , Gray Caroline , Rees Paul , Bibby Matthew , Wu Hsing Yu , Zheng Xiao
Published: January 2016

We report on an ambitious project in the field of automation, applied to bound and free abrasive processing of precision and ultra-precision surfaces, with potentially far-reaching consequences. This involves two main aspects:- directly processing surfaces using industrial robots, and combining robots with Zeeko CNC polishing machines to automate operations that are currently manual. These form steps towards our ultimate vision of the Integrated Manufacturing Cell for bespoke optics rather than mass-produced, and manufacture of other precision surfaces including prosthetic joint implants. Projects such as the European Extremely Large Telescope provide a relevant case study, where significant numbers of high-value bespoke optics are required.
Optimizing the Grinding Process through Reduction of the Loading of Grinding Tool by Infiltration
Authors: Azarhoushang Bahman , Rinderknecht Rolf , Vesali Alireza , Struss Juergen
Published: January 2016

The loading of the grinding wheel and adhesion of the workpiece material to the cutting edges of the grinding tool are among the main reasons which limit the process efficiency when grinding ductile materials. The micro topography of the grinding tool changes drastically as a result of loading. Higher grinding forces and temperatures, poorer surface quality and process accuracy are the consequences of the adhesion of the workpiece material to the grinding tool surface. A novel and promising technique to reduce the possibility of loading and adhesion in the grinding process is the infiltrating of the grinding tool. This study describes the results of infiltration of vitrified bonded conventional grinding wheels with graphite in the surface grinding process. The effects of infiltration have been studied for the first time on various grinding wheels with different grain materials, grit sizes, porosity and hardness. Two different types of steel which are very popular in the automobile industry, 100Cr6 and 16MnCr5, were chosen as the workpiece material by the surface grinding experiments. The selected cutting parameters cover a wide range of the practical surface grinding processes which are utilized generally in the industry. It has been experimentally shown that the type of infiltration plays an important role in reducing the loading of the wheel. Better surface quality and longer dressing intervals are the main results of the infiltration of the grinding tools.
Experimental Investigation on Bronze-Bonded CBN Formed Grinding Wheel by Means of Electro-Discharging Dressing
Authors: Yu Jian Wu , He Li Hua , Luo Hong , Yin Shao Hui
Published: January 2016

High-efficiency and precision machining of complicated components can be realized by using metal-bonded CBN grinding wheel. However, the difficulty in dressing those superabrasive grinding wheels is one of the main obstructions to popularize its application in industry. Different from the traditional methods, the aim of the paper is to investigate the electro-discharge dressing of bronze-bonded CBN formed grinding wheel. Based on the analysis of electrical discharge parameters and grinding performance, the results show that electro-discharge dressing of CBN formed grinding wheel is feasible. With the increase of pulse duration, pulse voltage and pulse current, the dressing efficiency is increasing, more abrasive grains are protruding, but surface topography of grinding wheel is worsen. Therefore, grinding tests show that, in order to get the dressing quality better and keep the dressing efficiency higher, the bigger electrical discharge parameters are chosen for rough dressing process and the smaller ones are chosen for finishing process.
An interesting post endoscopy occurrence
Authors: Mahalingam Preethi , Dineshchandra Viral Vyas , Palaniswamy Kallipatti Ramasami
Published: January 2016

It is important to be aware of certain rare but benign occurrences that follow endoscopic procedures. This would help to manage the case accordingly, with minimal investigations and interventions.
Диссипативные и неунитарные решения операторных коммутационных соотношений
Authors: Makarov Konstantin Anatol'evich , Tsekanovskii Eduard R
Published: January 2016

Изучаются (обобщенные) полувейлевы коммутационные соотношения вида $U_gAU_g^*=g(A)$ на $\operatorname{Dom}(A)$, где $A$ - оператор с плотной областью определения, а $G\ni g\mapsto U_g$ является унитарным представлением подгруппы $G$ афинной группы $\mathcal G$ (группы аффинных отображений действительной прямой, сохраняющих ориентацию). Если $A$ - симметричный оператор, то группа $G$ индуцирует действие/поток на единичном шаре в операторном пространстве сжимающих отображений из $\operatorname{Ker}(A^*-iI)$ в $\operatorname{Ker}(A^*+iI)$. Для данного потока доказаны несколько теорем о неподвижных точках. В случае однопараметрических непрерывных подгрупп линейных отображений самосопряженные (максимально диссипативные) операторы, соответствующие неподвижным точкам потока, дают решения для (редуцированных) обобщенных коммутационных соотношений Вейля. Показано, что в диссипативном случае редуцированные соотношения Вейля допускают ряд представлений, не являющихся унитарно-эквивалентными; для индексов дефекта $(1,1)$ основные результаты можно усилить и вынести в отдельный случай.
Cупералгебраическое представление матриц Дирака
Authors: Monakhov Vadim Valerievitch
Published: January 2016

Рассматривается клиффордово расширение алгебры Грассмана, в котором операторы построены из произведений грассмановых переменных и производных по ним. Показано, что в этой алгебре существует подалгебра, изоморфная матричной, и что в ней дополнительно имеются операторы обобщенной матричной алгебры, перемешивающие состояния с разным числом грассмановых переменных. Показано, что данные операторы являются расширением понятия спин-тензоров на случай суперпространства. Построено представление матриц Дирака в виде операторов обобщенной матричной алгебры.
Теория квазиупругих атомных реакций в переменном электрическом поле
Authors: Popov Yurii Vladimirovich , Kouzakov Konstantin Alekseevich , Bulychev Andrew Andreevich , Vinitsky Sergue Il'ich
Published: January 2016

Для квазиупругих $(e,2e)$-атомных реакций в присутствии стоячей электромагнитной волны предлагается вариант теории, которая строится по аналогии со стационарным случаем. Попутно формулируются математические проблемы, которые требуют своего решения для строгого обоснования данной теории.
Novejše krajšave v pogovorni francoščini
Authors: Pogačnik Vladimir
Published: January 2016

Avtor se v članku vrača k besedotvornemu postopku krajšav, ki ga je raziskoval že pred štiridesetimi leti v svojem magistrskem delu. Članek želi na primeru korpusa, ki je nastal na podlagi spremljanja oddaje Télématin na frankofonski televizijski mreži TV5, dokazati, da je krajšanje živ in razširjen postopek, ki se pojavlja predvsem v različnih oblikah govorne komunikacije.
Lorsque (se) voir ne voit plus
Authors: Perko Gregor
Published: January 2016

Dans le prolongement des analyses proposées dans les sections 5 et 6, on peut faire remarquer que se voir, de même que voir, manifeste un degré très élevé de subjectivation. Se voir accepte le changement de domaine de perception et même « son atténuation » au profit d’un domaine plus abstrait. On observe également que le sujet peut perdre une grande partie du contrôle du procès. Dans ce cas-là, il cesse d’être « pleinement » un siège d’action, d’expérience ou de responsabilité. Souvent, seule une lecture métonymique permet de lui réattribuer une partie du contrôle perdu, comme c’est le cas dans l’exemple cidessous.
La phrase emhatique et ses équivalents en Slovene
Authors: Schlamberger Brezar Mojca
Published: January 2016

L'importance de bonnes connaissances en grammaire française dans l’enseignement universitaire avait depuis toujours une position centrale dans le cadre du Département des langues et littératures romanes de la Faculté de Lettres de l’Université de Ljubljana1. L’enseignement de la grammaire procédait par la morphologie verbale et non-verbale et aboutissait à la syntaxe comme le point culminant. La syntaxe du français, enseignée par Mme Elza Jereb, était centrée surtout sur l’usage contemporain du français, prenant en compte aussi bien le français standard que les expressions plus familières. Sa grammaire Francoska slovnica po naše (Jereb 1995) est une grammaire du français langue étrangère qui se veut pédagogique à l'instar des grammaires pédagogiques françaises, parues dans la même époque. Nous pouvons souligner ici la différence entre une grammaires de référence ou descriptives, qui englobe le savoir sur une langue, et les grammaires d’apprentissage ou pédagogiques, qui se veulent utiles pour l’apprenant d’une langue étrangère.
L’usage des contes francophones pour le développement des compétences langagières
Authors: Žugelj Nataša
Published: January 2016

Les contes traditionnels sont un genre littéraire qui constitue un excellent support authentique pour le travail sur la langue dans une classe de FLE. S’ils sont accompagnés d’activités variées et ludiques, la découverte ou le perfectionnement d’une langue étrangère peut se faire d’une manière plaisante avec des apprenants de tous âges. En effet, ils se prêtent bien au développement des compétences langagières et sont un excellent terrain d’observations linguistiques, d’enrichissement lexical. De plus, par leur relative brièveté et par un contenu universellement connu, ils proposent un cadre rassurant pour l’exploitation pédagogique.
Poučevanje strategij za učenje besedišča pri pouku nemščine v slovenskih gimnazijah
Authors: Retelj Andreja
Published: January 2016

V prispevku se osredotočamo na poučevanje strategij za učenje besedišča pri pouku nemščine v slovenskih gimnazijah. Zanimalo nas je, katere strategije za učenje besedišča učitelji nemščine v gimnazijah načrtno poučujejo in kako pogosto dijake z njimi seznanjajo. Spletni vprašalnik, ki temelji na Schmittovi (1997) in Nationovi (2001) taksonomiji in vsebuje 37 strategij za učenje besedišča, je rešilo 72 učiteljev nemščine. Rezultati raziskave kažejo, da so pri pouku nemščine prisotne vse strategije za učenje besedišča. Učitelji najpogosteje poučujejo 10 strategij, 19 strategij vključujejo občasno in 8 redko. Zelo pogosto ne poučujejo nobene strategije. Pri pouku pogosto poučujejo strategi- je, ki spodbujajo učenje pomena besede iz konteksta in ugibanje pomena ter aktivno rabo besedišča, občasno pa tudi strategije, ki obsegajo ostale vidike. Redko se posvečajo strategijam za memoriranje besed. Ugotavljamo, da učitelji nemščine z vključevanjem strategij za učenje besedišča prispevajo k učenčevi samostojnosti pri učenju nemščine in posredno pri učenju drugih tujih jezikov.
Uporaba avtentičnih posnetkov pri poučevanju italijanščine odraslih
Authors: Pegam Polona
Published: January 2016

Namen članka je orisati uporabno vrednost avtentičnih posnetkov pri poučevanju italijanščine odraslih. Občasno vključevanje takšnih didaktičnih posnetkov kot dodatnih gradiv v učni proces predstavlja dodatno vrednost pri poučevanju. Izbrani posnetki se prilagajajo skupini in se tudi vsebinsko vključujejo v snov. Tovrstna gradiva predstavljajo privlačen način za urjenje jezikovnih spretnosti in tečajnike spodbujajo k ohranjanju stika z jezikom tudi zunaj učnih ur. Učenje italijanščine ima namreč na območjih, ki so oddaljena od slovensko-italijanske meje, drugačen položaj, saj je tu vsakodnevnega stika z »živim« jezikom manj. Tako z rabo avtentičnih posnetkov povečamo tudi slušni vnos. Če je slušni vnos tudi vizualno podprt, omogoča lažji vnos informacij, hitrejše pomnjenje in zmožnost kasnejšega priklica.
Zur Theorie und Praxis des Fächerübergreifenden und Fächerverbindenden Daf Unterrichts
Authors: Kosevski Puljić Brigita
Published: January 2016

Im vorliegenden Beitrag wird anhand einer Untersuchung der theoretischen Hintergründe über fächerübergreifendes Lernen im Fremdsprachenunterricht und anhand einer Diskus- sion über den praktischen Einsatz im Unterricht versucht, eine Antwort auf die Fragen zu finden, was fächerübergreifendes bzw. fächerverknüpfendes Lernen für den fremdsprach- lichen Unterricht bedeutet und wie sich eine solche Form von Unterricht darin integrieren kann. Dabei soll bedacht werden, dass diese Integration immer damit verbunden ist, wie stark sie – im positiven Sinne – den Fremdsprachen- und Sachunterricht beeinflusst. Zuerst soll vorgestellt werden, wie das fächerübergreifende Lernen im Curriculum der Gymnasi- alstufe realisiert wurde und welche die Gründe hierfür waren.
Nuovo contatto A1 in nuovo contatto A2
Authors: Mertelj Darja
Published: January 2016

V letih 2014 in 2015 je na tržišče prišel prenovljeni učbeniški komplet Nuovo Contatto, in sicer za ravni A1 in A2, v pripravi za leto 2015-2016 je še B1.1 Založba Loescher doslej na slovenskem tržišču še ni bila stalno prisotna, čeprav so nekateri učitelji poznali predhodni učbeniški komplet Contatto. Sedaj je omenjena učbeniška serija v veliki meri prenovljena s precej elementi predhodnega koncepta, ki so jih nekateri slovenski učitelji italijanščine kot tujega/drugega jezika že cenili.
Nuovo Espresso 1, 2, 3 (za ravni A1, A2, B1)
Authors: Mertelj Darja
Published: January 2016

Delovni učbeniki Nuovo Espresso 1, 2, in 3 so na slovenskem tržišču ponovno na voljo, tokrat v veliki meri prenovljeni in vendarle z ohranjenim konceptom, zaradi katerega so ga v preteklih 15 letih množično uporabljali številni slovenski učitelji italijanščine kot tujega jezika. Niti v predhodnih verzijah niti sedaj učbenik s strani avtorjev in založbe ni namenjen gimnazijcem in ostalim srednješolcem, vendar ga prav tej ciljni skupini pričujoča prenovljena izdaja najmočneje približa, predvsem zaradi video posnetkov v vsaki lekciji, kjer gre za krajše, humorne prigode in nezgode mladih ljudi v njihovem vsakdanu.
Alles Stimmt! 1, 2, 3 in 4
Authors: Kosevski Puljić Brigita
Published: January 2016

Učbeniški komplet 1-4 Alles stimmt! je slovenska priredba učbeniškega kompleta DaF kompakt A1-B1. Deutsch als Fremdsprache für Erwachsene (Sander, Ilse in dr.), založbe Ernst Klett Verlag, Stuttgart. Gradivo je prirejeno v skladu z ustreznimi učnimi načrti za nemščino, stopnje težavnosti besedil in jezikovnih struktur pa sledijo Skupnemu evropskemu jezikovnemu okvirju (SEJO).
Bibliografija Elze Jereb za obdobje 1965-2015
Authors: Šorli Metka
Published: January 2016

Pri izdelavi bibliografije mag. Elze Jereb so mi bili v oporo bibliografski zapisi v cobissu (73 od 152 enot), med drugim tudi pri iskanju originalnih besedil, dostopnih v Osrednji humanistični knjižnici Filozofske fakultete, NUK-u in drugih slovenskih knjižnicah. Kljub želji po čim izčrpnejši predstavitvi profesoričinega opusa bibliografija ni popolna.* Zavestno so izvzeti številni predmetni izpitni katalogi za tuje jezike, kjer je sodelovala pri redakciji splošnega besedila, ter vsi ponatisi izdaj. Vrsto let je bila soavtorica predmetnih izpitnih katalogov za maturo iz francoščine (izdaje v letih 1993-2008 za maturo 1995-2010) ter glavna urednica dveh publikacij, revije Vestnik za tuje jezike in književnosti (1982-1988) in skupaj z Dragom Druškovičem - Livre slovène (1976-1981), kar ni vključeno v spodnji, po letnicah urejeni prikaz. Iz slednjega se je prav gotovo izmuznil še kak profesoričin prispevek (npr. nekateri prevodi, gradivo za seminarje, namenjene osnovnošolskim in srednješolskim profesorjem francoščine ter prevajalcem).
Onomastic Interferences in the Language of Migration
Authors: Jieanu Ioana
Published: January 2016

In case of bilingual speakers, proper names undergo different transformations, depending on the contextual character of a manifestation of meanings, “the relationship between the proper name and the denoted object being temporary, dependent on the verbal and situational context” (Tomescu 1998: 1). Within the scope of the current economic migration of Romanians to Spain and Italy, the names of Romanian people have undergone various modifications under the influence of Spanish and Italian onomastics. In the present work, the performance of two main tasks is described: an analysis of the interferences which emerge within communication, in case of the proper names of Romanian people who have emigrated to Spain and Italy; and classification of the proper names of new-born children within Romanian families that have settled in these countries.
A philosophical critique of Ignocentric search for political Messiah in Nigeria
Authors: Olatunji Cyril-Mary Pius
Published: January 2016

Many of the philosophers of African politics who have argued that the political challenges of Nigeria, and of  Africa as a whole are as a result of the impunity and corruption of post-independence Nigeria leaders also  give the impression that the people of Nigeria are mere innocent victims because in their arguments all  the ills of  the Nigerian state exist only because the country have not experienced or discovered an honest and capable political leader. The scholars argue to the effect that all that Nigeria can do is simply to hope for the  ascendance of a Messiah, who being an honest, capable and patriotic leader will on his own volition become committed to the cause of reversing the situation in order to turn around all the ills of the nation. Employing the examples of two prominent scholars of African politics (Chinua Achebe and Larry Diamond) the paper employs the epistemological rigor of analysis and logic to examine and make a critique of the underlying  assumptions of the scholars and identifies the theoretical flaws of believing that political representatives are substantively political leaders, that Nigerians are helpless victims who on their own are incapable of reversing the situation and that Nigeria should hope for a political saviour who will turn around all the social and political ills of Nigeria on his own accord.Keywords: Ignocence, Messianism, Epistemology, Democracy, Nigeria