bluuebunny/crossref_metadata_2025 huggingface dataset:
Fracture Behavior of an AlMgMnSc Alloy at Different Temperatures
Authors: Borisova Yuliya Igorevna , Yuzbekova Diana , Mogucheva Anna
Published: January 2021

An Al-4.57Mg-0.35Mn-0.2Sc-0.09Zr (wt. %) alloy was studied in the fine-grained state obtaining after equal channel angular pressing. The mechanical behavior of alloy at the temperatures 173 K, 298 K and 348 K and at strain rate 1×10–3 s–1 is studied. Increase of the temperature testing from 173 K to 348 K decreases the yield stress by 80 MPa, the ultimate tensile strength by 60 MPa while elongation-to failure increases by a factor of 1.4. It was found that at temperatures of 298 and 173 K, the studied alloy mainly demonstrates the mode of ductile fracture, and at a temperature of 348 K the mechanism can be described as mixed ductile-brittle fracture. It was also established that of the studied alloy is the temperature dependence of the size of the dimples on the fracture surface. The formation of smaller dimples in the samples deformed at 298 K was observed.
Recent Developments in the Processing of Advanced Materials Using Severe Plastic Deformation
Authors: Kawasaki Megumi , Figueiredo Roberto B. , Langdon Terence G.
Published: January 2021

The processing of bulk metals through the application of severe plastic deformation (SPD), using procedures such as equal-channel angular pressing (ECAP) and high-pressure torsion (HPT), is now well established for the fabrication of materials with exceptionally small grain sizes, usually in the submicrometer range and often having grain sizes at the nanometer level. These grain sizes cannot be achieved using thermo-mechanical processing or any conventional processing techniques. Recently, these procedures have been further developed to process alternative advanced materials. For example, by stacking separate disks within the HPT facility for the synthesis of bulk nanocrystalline metastable alloys where it is possible to achieve exceptionally high hardness, or by pressing powders or metallic particles in order to obtain new and novel nanocomposites exhibiting unusual properties.
Design Solutions from Material Selection for Rib Fixators
Authors: Arreguin Jose Luis , Montanari Roberto , Ceccarelli Marco , Ambrogi Vincenzo , Richetta Maria , Torres-San-Miguel Christopher Rene , Varone Alessandra
Published: January 2021

The problems for fixing rib fractures are usually challenged with different rib fixators whose design strongly depends of the material selected for construction. Main issues refer to rib surgery implantation and tissue acceptance for a duration longer than the osteosynthesis. In this paper we discuss how a material selection can strongly suggest different design solutions both in shape of a rib fixator and even constraining or directing the surgical application with an invasive or noninvasive implantation. In particular, in discussing the general issues and specific experiences of the authors the paper illustrates examples of two different solutions under patent request that are dictated by the material whose selection give the design solutions with innovative aspects.
Change of Microstructure and Analysis of Fracture of the Ti-50.8 at.% Ni Alloy in the Ultrafine-Grained State after Multiple Martensitic Transformations with a Large Number of Cycles
Authors: Churakova Anna , Gunderov Dmitriy
Published: January 2021

The microstructure and mechanical properties of the ultrafine-grained Ti–50.8 at.% Ni alloy after thermal cycling treatment with the number of cycles up to 250 was investigated. A fractographic analysis of the samples after tensile tests was carried out. The fracture pattern of the alloy in the UFG state has a viscous character with microdepths on the fracture surface. The average size of microdepths decreases as the number of thermal cycles increases up to n= 250.
Delamination of Pearlitic Steel Wires: Role of Strain Partition on Mechanical Properties of Pearlitic Wires
Authors: Prasad Akula Durga Vara , Mukherjee Subrata
Published: January 2021

Cold drawn wires were produced by drawing the pearlitic wire rod (5.5 mm diameter). Cold drawing involved multiple stages to a final drawing strain of ≈ 2.5. The cold drawing alters the pearlite morphology. During the wire drawing, the change in morphology is location dependent. This will create the gradient in stain and strain mode between the surface and the center. This led to have a strain partition among ferrite and cementite phases. The strain partitioning plays a major role in the final tensile and torsional performance of the cod drawn wire. The present work dealt with the experimental and their numerical simulations of stress gradients and the role of pearlite morphology on tensile and torsional properties of the pearlitic steel wire.
Biocompatibility of Anodized Low-Cost Ti-4.7Mo-4.5Fe Alloy
Authors: Abdelrhman Yasser , Kobayashi Sengo , Okano Satoshi , Okamoto Takeaki , Gepreel Mohammed A.
Published: January 2021

Self-organized TiO2 nanotubes were generated on the surface of the designed alloy Ti-4.7Mo-4.5Fe (TMF55) by electrochemical anodization process to investigate the effect of nanostructured on the biocompatibility. The biocompatibility of the designed alloys showed very promising results compared to those of Ti-6Al-4V ELI alloy, especially for the untreated and nanostructured surfaces of the specimens with diameter size less than 35 nm. By increasing the diameter of nanotube, the biocompatibility is decreased. The most convenient compatible alloy was in favor of TMF8 alloy, making this V-free low-cost alloy is a promising candidate for replacing the commercial Ti-6Al-4V ELI alloy in biomedical applications. Keywords: Self-organized TiO2 nanotubes, biocompatibility, Titanium alloys, Cell Counting Kit-8, WST-8 assay.
Effect of Thermomechanical Treatments on the Mechanical Properties of New Low-Cost Ti-Fe-Nb-Zr Alloys
Authors: Gepreel Mohammed A. , Niinomi Mitsuo
Published: January 2021

The development of new low-cost alloys composed of common elements that show high biocompatibility and mechanical properties matching with human bone is the target of many researches recently. Design and controlling the mechanical properties of newly developed set of Ti-xFe-3Zr-yNb (x=3-8 & y=2-3, at.%) low-cost alloys through applying different thermomechanical treatments is the aim of this work. Fe-content in the present designed alloys is changing in the range 3 to 8 at.%. The hardness and Young's modulus of the alloys were measured for the alloys in the solution treated, hot rolled and subsequent ageing at 400 °C and 550 °C. The phases separation and hence hardness of the aged alloys at 400 °C and 550 °C are highly dependent on the Fe-content in the alloy. The Young's modulus of the alloys is also changing with the Fe-content and heat treatment, where lowest modulus (~80GPa) is shown in the Ti-5Fe-3Zr-3Nb alloy in the solution treated condition.
Fracture Toughness and Fatigue Crack Growth Characteristics of UFG Microalloyed and IF Steels Processed by Critical Phase Control Multiaxial Forging
Authors: Ghosh Sumit , Mula Suhrit , Somani Mahesh Chandra , Kömi Jukka I.
Published: January 2021

The aim of the current study is to design multiaxial forging (MAF) schedules in order to achieve submicron-grained (<1μm) structure in a microalloyed (MA) steel as well as an interstitial-free (IF) steel, which could impart a good combination of yield strength and tensile ductility. At the same time, an effort has been made to evaluate the fracture toughness characteristics by conducting 3-point bend tests and computing the KQ, Kee and J-integral values of ultrafine grained (UFG) samples and correlating them with the microstructure, besides evaluating the other mechanical properties. Fatigue strength in the high cycle fatigue (HCF) regime were also investigated and fracture mechanisms analyzed and comparison established between differently processed samples. The microstructural analysis was performed using transmission electron microscopy (TEM) and Electron backscatter diffraction (EBSD) and results corroborated with the mechanical properties. Superior combinations of yield strength (YS), ductility (% El.), fracture toughness (Kee) and high cycle fatigue strength (σf) were obtained under certain conditions, i.e., i) MA steel: intercritical (α+γ) phase regime (~Ar1) controlled and 15-cycle multiaxially forged (MAFed) (YS=1027MPa, %El.=8.3%, σf=355MPa and Kee=90MPa√m), and ii) IF steel: ferritic region (<Ar1) controlled 18-cycle MAFed (YS=881MPa, %El.=11.2%, σf=255MPa and Kee=97MPa√m). In the case of MA steel, an enhancement of the fatigue and fracture toughness properties can be ascertained following the formation of uniformly distributed nanosized fragmented cementite (Fe3C) particles (~35nm size) present in the submicron sized (average ~280nm size) ferritic microstructure. In contrast, in the case of IF steel, this is ascribed to the development of submicron sized ferrite grains (average ~320nm) along with a high density of dislocation substructures. These fine dislocation cells/substructures along with the nanosized Fe3C particles could effectively block the initiation and propagation of cracks and thereby enhance the fatigue endurance and fracture toughness of the steel. Superior fracture toughness along with high mechanical properties in submicron-grained condition render the two steels highly useful for high-strength structural applications.
Grain Orientation Spread in Dynamically Recrystallized Austenitic Steel
Authors: Belyakov Andrey , Torganchuk Vladimir , Rybalchenko Olga V. , Dobatkin Sergey , Kaibyshev Rustam
Published: January 2021

Some feature of discontinuous dynamic recrystallization (DRX) in an Fe-0.4%C-18%Mn austenitic steel during isothermal compression tests at temperatures of 973-1373 K and strain rates of 10-3-10-1 s-1 were studied. The DRX microstructures consisted of various grains, i.e., DRX nuclei, growing DRX grains, and work-hardened DRX grains, which differentiated with the grain orientation spread (GOS). DRX was commonly promoted by a decrease in temperature-compensated strain rate, i.e., Zener-Hollomon parameter (Z), corresponding to an increase in deformation temperature and/or a decrease in strain rate. In contrast, the GOS distribution varied non-monotonously with Z. The large area fraction of DRX grains with small GOS below 1° appeared at definite temperature/strain rate conditions. The large fraction above 0.6 of DRX grains with small GOS was observed in DRX microstructures with a large ratio of CSL Σ3 boundary fraction to low-angle subboundary fraction. The GOS distribution in the DRX microstructures is discussed in terms of the DRX grain nucleation and growth rates.
Shear Banding in Rotated Goss Grains and its Effect on the Formation of Cube Texture in Non-Oriented Electrical Steel
Authors: He You Liang , Mehdi Mehdi , Hilinski Erik J. , Zhou Tom , Badgley Peter , Kestens Leo A.I. , Edrisy Afsaneh
Published: January 2021

Cube texture ({001}<100>) is a desired final texture in non-oriented electrical steel sheets used as magnetic cores because it contains two easy <100> axes in the sheet plane, which is beneficial to the magnetic properties. However, the cube texture is very difficult to form in non-oriented electrical steels through conventional rolling and annealing. It has been shown that after conventional rolling, the deformed <111>//ND (normal direction) grains provided nucleation sites for the unfavourable <111>//ND texture during recrystallization, leading to a final <111>//ND texture. To eliminate the <111>//ND texture and promote the {001}<100> texture, an uncommon rolling process, i.e. inclined rolling, was adopted in this study. By rotating the hot rolling direction by 60° around the ND, an uncommon initial texture, the rotated Goss ({110}<110>), was intentionally generated. This was intended to change the orientation flow during plastic deformation, and suppress the formation of the conventional <111>//ND texture in the deformed microstructure. Plane-strain compression (rolling) of the rotated Goss grains produced shear bands within these grains due to their large Taylor factor. Electron backscatter diffraction (EBSD) characterization of the shear bands illustrated that, crystallites with the cube orientation were formed within these shear bands. During recrystallization, the shear bands provided preferential nucleation sites, and the cube crystallites preferentially nucleate within the shear bands. These cube crystals can then grow into the deformed matrix, and lead to the formation of a strong cube texture in the final annealed steel sheets.
Microstructure and Tensile Properties of Sn-Ag-Cu-In-Sb Solder
Authors: Hirai Yukihiko , Oomori Kouki , Morofushi Hayato , Shohji Ikuo
Published: January 2021

Microstructures and tensile properties at 233 K, 300 K and 398 K of Sn-3.0 mass%Ag-0.5 mass%Cu (SAC305) and Sn-Ag-Cu-In-Sb solder were investigated by using miniature size specimens with 0.5 mm diameter, which can reproduce the microstructure of the real solder joint. In this study, three kinds of Sn-Ag-Cu-In-Sb solder (SAC305-6.0 mass%In-1.0, 2.0 and 3.0 mass%Sb) were used. The microstructure of SAC305 consisted of a single crystal grain. On the other hand, the microstructures of Sn-Ag-Cu-In-Sb solder consisted of polycrystalline. The number of crystal grains per the cross section of SAC305-6.0In-1.0Sb was stably several tens or more. The tensile strength of Sn-Ag-Cu-In-Sb was improved approximately 2 times that of SAC305. Also, the variation in tensile strength of SAC305 at 233 K was large due to anisotropy of the crystal grain. In contrast, the variation in tensile strength of Sn-Ag-Cu-In-Sb at 233 K was lower than that of SAC305. In particular, that of SAC305-6.0In-1.0Sb was reduced to approximately a sixth of that of SAC305. It seems that the effect of anisotropy of the crystal grain is decreased by polycrystallization in SAC305-6.0In-1.0Sb.
Friction Stir Welded AISI 304 Metal Sheets for Application in Food Implants
Authors: Cerri Emanuela , Pirondi Alessandro , Bergmann Jean Pierre
Published: January 2021

Stainless steels are indispensable materials in many industrial fields. They can be easily shaped and joined by traditional welding methods. Some problematics such as possible decrease in corrosion resistance at the welding bead and in the heat-effected zone, residual stress, crack formation and distortions may take place after welding. Friction Stir Welding (FSW) may be used for joining stainless steels in a single pass and for optimising microstructure and mechanical properties of the processed region. The application of FSW to the widely used AISI304 stainless steel is investigated in food implants. The mechanical properties together with corrosion resistance and surface finishing are characterized. A high energy input is chosen for the welding (2000 rpm tool rotational speed and 50 mm/min advancing speed). The stirred zone (SZ) is characterized by optical microscopy. Vickers microhardness in the SZ results 37% higher than in the base material. Tensile tests highlight elongations up to 40% keeping maximum stress values at 600 MPa. All samples pass accelerated corrosion tests that simulate 20 years of cleaning cycles in a typical food implant.
Effect of Alloying Element on Mechanical Properties of High Strength Austenitic Steel
Authors: Ueda Keiji , Izumi Daichi , Ishida Toshinori , Murakami Yoshiaki
Published: January 2021

A high strength austenitic steel is expected as a structural material for cryogenic use because fcc material does not cause a cleavage fracture despite high strength. High manganese steel which is a strong candidate material of the cryogenic high strength austenitic steel was originally famous for the Hadfield steel and widely applicable in actual use. In general, an excellent cryogenic toughness of the high manganese steels is achieved by obtaining stable fcc microstructure with an adequate amount manganese which is a typical austenite former alloy. However, as addition of manganese is not effective for increasing strength, other strengthening alloying elements like carbon and chromium need to be added. In this study, an effect of alloying elements on strength and cryogenic toughness of the high manganese austenitic steel is studied.
Synthesis PbFCl-Type Mixed Anion APX(A=Hf, X=S, Se) Superconductors Related with Topological Materials by High-Pressure Technique
Authors: Kitô Hijiri , Kawashima Kenji , Iwakiri Kousuke , Nishio Taichiro , Ishida Shigeyuki , Fujihisa Hiroshi , Gotoh Yoshito , Iyo Akira , Ogino Hiraku , Eisaki Hiroshi , Yoshida Yoshiyuki
Published: January 2021

We performed a systematic study of the crystal structure, physical properties, and electronic structure of PbFCl-type intermetallic APX(A=Zr, Hf, X=S and Se) superconductor. We successfully synthesized single-phase polycrystalline samples for the Se substitution range of 0.4≤x≤0.8 in Zr(P2-xSex) using high pressure technique. On the other hand, S substitution range in Zr(P2-xSx) was narrow of 0.4≤x≤0.6, the S substitution range in Hf(P2-xSx) was narrow of x≈0.55, and the Se substitution range in Hf(P2-xSex) was also very narrow of x≈0.4. Zr(P2-xSex) exhibits a dome-like superconducting phase diagram for the substitution amount x. The superconducting transition temperature (Tc) is achieved at approximately x≈0.75 at which point the Tcis 6.3 K for Zr(P1.25Se0.75), 5.5 K for Hf(P1.30Se0.70), 5.0 K for Zr(P1.325S0.675), and 4.6 K for Hf(P1.50S0.50), respectively. Tcfor Zr(P1.25Se0.75) is increased from 6.3 K to 7.6 K by partially substituting a non-magnetic rare earth Sc atom for Zr. Single crystals of Zr(P1.25Se0.75) and partially substituted by Sc atom for Zr site of the ZrP2-xSexwere also grain grown using high pressure technique. Plate-like single crystal with approximate edge sizes of up to 500 × 300 × 20 μm3for (Zr0.50Sc0.50)PSe nominal composition was obtained. Tc= 8.36 K was reached and the Hc1//c-axis(0) and Hc1⊥c-axis(0) roughly determined are 0.0045 T and 0.0038 T, respectively. Assuming the type-II superconductivity in dirty limit, the Hc2//c-axis(0) value of 1.33 T was also obtained. In this presentation, the crystal growth and physical properties of this APX(A=Zr, Hf, X=S and Se) superconductor has reported.
Analysis of the Strain Distribution and Texture Measurements in Asymmetric Rolling (AR) and Asymmetric Accumulative Roll Bonding (AARB)
Authors: Godoi Renan P. , Zanquetta Bianca D. , Rubert José Benaque , Bolmaro Raul E. , Avalos Martina C. , Sordi Vitor Luiz , Kliauga Andrea Madeira
Published: January 2021

Severe plastic deformation (SPD) with strong shear component is required to promote both grain refinement and texture randomization. When Asymmetric rolling (AR) is applied as asymmetric accumulative roll bonding (AARB), it enables the production of architectured microstructures and metallic composites. Finite element (FE) simulations of AR and AARB were employed to understand the influence of pass thickness reduction (PTR) on the through thickness variation of the velocity gradient. The influence of the PTR up to a total thickness reduction of 50% and the effect of a single 50% reduction step in a bi-layer bonding condition was analyzed. The influence of these process parameters on the strain and rigid body rotation components was compared with the experimental data obtained on an AA1050 aluminum. A better shear to compression ratio across the sheet thickness is achieved by PTRs lower than 30%; at a PTR of 50% the texture is dominated by the frictional shear generated at the roll-sheet interface and the process has a stronger compressive character. This indicates that simple ARB followed by AR with smaller PTRs should generate a better shear distribution than AARB alone.
Microstructure and Tensile Properties of TRIP-Aided Steel Sheet Subjected to Hot-Rolling and Austempering
Authors: Kobayashi Junya , Sawayama Hiroto , Kakefuda Naoya , Itoh Goroh , Kuramoto Shigeru , Hojo Tomohiko
Published: January 2021

Various high strength steel sheets for weight reduction and safety improvement of vehicles have been developed. TRIP-aided steel with transformation induced plasticity of the retained austenite has high strength and ductility. Conventional TRIP-aided steels are subjected to austempering process after austenitizing. Generally, elongation and formability of TRIP-aided steel are improved by finely dispersed retained austenite in BCC phase matrix. The finely dispersed retained austenite and grain refinement of TRIP-aided steel can be achieved by hot rolling with heat treatment. Therefore, the improvement of mechanical properties of TRIP-aided steel is expected from the manufacturing process with hot rolling and then isothermal transformation process. In this study, thermomechanical heat treatment is performed by combining hot rolling and isothermal holding as the manufacturing process of TRIP-aided steel sheets. The complex phase matrix is obtained by hot rolling and then isothermal holding. Although the hardness of the hot rolled and isothermal held TRIP-aided steel is decreased, the volume fraction of retained austenite is increased.
Temperature-Dependent Mechanical Stability of Retained Austenite in Thermomechanically Processed 3Mn Steel
Authors: Kozłowska Aleksandra , Grajcar Adam , Janik Aleksandra , Radwański Krzysztof
Published: January 2021

The temperature-dependent mechanical stability of retained austenite in medium-Mn transformation induced plasticity 0.17C-3.3Mn-1.6Al-1.7Al-0.22Si-0.23Mo thermomechanically processed steel was investigated using scanning electron microscopy (SEM), electron backscatter diffraction (EBSD) and X-ray diffraction (XRD) methods. Specimens were deformed up to rupture in static tensile tests in a temperature range 20–200°C. It was found that deformation temperature affects significantly the intensity of TRIP effect. In case of specimens deformed at temperatures higher than 60°C, a gradual temperature-related decrease in the stability of γ phase was noted. It indicates a progressive decrease of the significance of the TRIP effect and at the same time the growing importance of the thermally activated processes affecting a thermal stability of retained austenite.
Long Term Stability Evaluation of Stress Improvement Effect on Ni-Based Alloy Welds by Various Residual Stress Improvement Methods
Authors: Yu Li Na , Saida Kazuyoshi , Mochizuki Masahito , Nishimoto Kazutoshi , Chigusa Naoki
Published: January 2021

Stress corrosion cracking (SCC) is one of serious aging degradation problems for the Alloy 600 components of pressurized water reactors (PWRs). In order to prevent SCC, various methods such as water jet peening (WJP), laser peening (LP), surface polishing have been used to introduce compressive stresses at the surfaces of the PWR components. However, it has been reported that such compressive residual stress introduced by these methods might be relaxed during the practical operation, because of high temperature environment. In this study, the hardness reduction behavior of the Alloy 600 processed by LP, Buff and WJP in the thermal aging process has been investigated to estimate the stability of the residual stress improving effect by each method, based on the fact that there is a correlation between the compressive residual stress relaxation and the decrease of hardness. The behavior of the residual stress relaxation in the processed materials in the high temperature environment has been discussed with kinetic analysis.
Effects of Activated Carbon Counter Electrode on Bifacial Dye Sensitized Solar Cells (DSSCs)
Authors: Putri Tika Erna , Hao Yuan , Chawarambwa Fadzai Lesley , Seo Hyunwoong , Son Min Kyu , Kamataki Kunihiro , Itagaki Naho , Koga Kazunori , Shiratani Masaharu
Published: January 2021

The losses of solar cells are consisted of electrical losses and optical losses. Optical losses chiefly reduce the short-circuit current. Here we apply bifacial cell approach to increase light absorption and the short-circuit current of dye sensitized solar cells (DSSCs). We have employed activated carbon (AC) as a very low cost counter electrode, an alternative to Pt counter electrode. Addition of dimethyl sulfoxide (DMSO) and titanium carbonitride (TiCN) to AC increase the efficiency of bifacial DSSC at a mirror angle of from 5.10% to and , respectively. These results indicate that AC has the potential to replace Pt as a very low cost counter electrode of bifacial DSSCs. The bifacial DSSC system using double plane mirrors improve PCE to for Pt counter electrode at a mirror angle of , and for AC counter electrode at a mirror angle of , respectively.
Effect of Strain Rate on the Microstructure and β-Texture Evolutions in β-Processed Forging of a Near-β Titanium Alloy
Authors: Meng Ling Jian , Kitashima Tomonori
Published: January 2021

The effect of strain rate on the β texture evolution during two-step hot forging of Ti-6246 alloy was investigated. The two-step forging consisted of 15% or 50% prior-β forging at 980°C and subsequent 60% or 25% forging at 870°C in the (α + β) dual-phase region. The total compression ratio was 75%, and the investigated strain rates were 0.01 and 1.0 s−1. The β forging texture showed typical {001} and {111} body-centered cubic textures. With increasing compression ratio in the (α + β) region and at a strain rate of 0.01 s−1, the amount of precipitated α phase increased. Dynamic recrystallization was rarely observed after forging in the (α + β) region at a strain rate of 0.01 s−1. Large amounts of α precipitates lowered the {001} β texture intensity through slip transmission between the α and β phases under the Burgers orientation relationship. However, in specimens forged at a strain rate of 1.0 s−1, as the compression ratio in the β single-phase region increased, the growth of dynamic-recrystallized β grains was promoted at the prior-β grain boundaries, where α-phase precipitation was not substantial. These effects resulted in a higher {001} texture intensity of the β phase in specimens forged at 1.0 s−1 compared with that of the β phase in specimens forged at 0.01 s−1.
Additive Manufacturing of Multi Layered Bioactive Materials with Improved Mechanical Properties: Modelling Aspects
Authors: Krzyzanowski Michal , Svyetlichnyy Dmytro , Bajda Szymon
Published: January 2021

Multilayered laminate structures obtained by coating of ultrafine-grained metallic materials with bioactive and multifunctional composite coatings are considered for biomedical applications. Laser-assisted densification of multiple materials using laser cladding and selective laser melting is an alternative route to reduce the risk of early implant failure allowing for faster and cheaper fabrication. To understand the cooperative relationships between different factors that cam influence the manufacture of such bioactive laminates reflecting in their bioactivity and mechanical properties, the multi scale numerical modelling is applied. This work presents resent advances on development of integrated numerical models including generation, melting and solidification of the powder bed, considering surface flow, wettability, surface tension and other physical phenomena, specific mechanical and thermo-mechanical aspects and microstructure evolution.
In Situ Observation during Copper Alloy Brazing Using an X-Ray System
Authors: Miura Hirokazu , Okada Hiroki , Miyazawa Yasuyuki , Kanasaki Fumio
Published: January 2021

In general, a flux is used to braze a copper alloy. In many cases, when the molten brazing filler metal spreads in the set joint gap, vaporised flux and its residue are produced, and defects (mainly voids) are formed. Voids, which are formed on the brazed layer, cause deterioration in the strength and other properties. However, with conventional evaluation methods (e.g. ultrasonic or X-ray radiography tests), the behaviour of the molten brazing filler metal during the brazing process cannot be visually observed from the outside of the joint. Therefore, the void formation process cannot be clarified. To improve the quality of the brazed layer, it is necessary to elucidate the mechanism of void formation. The purpose of this study is to observe the behaviour of the molten brazing filler metal by performing an X-ray radiography test at the same time as brazing and to study how to reduce voids. In this study, a brass specimen was brazed with a Cu–P-based brazing filler metal. The specimen was brazed by heating in an electric furnace, and the specimen was irradiated with X-rays. The state where the molten brazing filler metal spread into the gap was photographed as the transmission image. Thereafter, the behaviour of the molten brazing filler metal was analysed.
Mechanical Behaviour of Beta Titanium Alloys
Authors: Muktinutalapati Nageswara Rao , Manivasagam Geetha
Published: January 2021

Beta titanium alloys have several attractive features; this has resulted in this group of alloys receiving much attention since 1980’s. Among the attributes which distinguish them for their superiority over other structural materials are (i) high strength to which they can be heat treated, resulting in high strength to weight ratio (ii) high degree of hardenability which enables heat treatment in large section sizes to high strength levels (iii) excellent hot and cold workability, making them as competitive sheet materials etc. The standard heat treatment consists of solution treatment in beta or alpha plus beta phase field followed by aging. However, certain aging treatments can render the materials in a state of little or no ductility; the designer has to be aware of this behaviour and has to keep away from such treatments while working with the materials. Such unfavourable aging treatments may adversely affect not only the static properties such as reduction in area and elongation in a tensile test, but also dynamic properties such as impact toughness. Results of fractographic studies are in line with those of mechanical testing. The authors would present the foregoing analysis, based primarily on the wide-ranging researches they carried out on beta titanium alloy Ti15-3 and to some extent data published by researchers on other grades of beta titanium alloys. An attempt is made to explain the mechanisms underlying the embrittlement reactions that take place in beta titanium alloys under non-optimal aging treatments.
Accidental poisoning with aluminum phosphide presenting with excessive cholinergic symptoms with response to atropine: A case report
Authors: Shakur Abubakar Muhammad , Garba Nuhu Abubakar , Ahmadu Ibrahim , Apollos Daniel , Asani Mustafa O , Aliyu Ibrahim
Published: January 2021

Accidental poisoning in children, though underreported in our environment, is common and could prove fatal. It is important to identify the primary chemical agent that is responsible for the poisoning. We present a case of accidental ingestion of fish poisoned with aluminum phosphide (AlP) used as rat poisoning by a 14-month-old girl. At presentation, the actual chemical content of the poison was not available and clinical features were suggestive of organophosphate poisoning. She was commenced on atropine together with other treatment, on which she made remarkable improvement. The atropine was continued with complete resolution of symptoms on the third day of admission. We, therefore, report a serendipitous use of atropine in the management of AlP poisoning with successful outcome.
COVID-19 India Tracker Application using Flutter
Authors: M.L. Sharma and Krishna Chandra Tripathi Sanju Kumar Sahu
Published: January 2021

Nowadays, COVID-19 is the biggest impediment for the survival of the human race. Again, as mobile
technology is now an important component of human life, hence it is possible to use the power of mobile
technology against the treat of COVID-19.
Every nation is now trying to deploy an interactive platform for creating public awareness and share the
important information related to COVID-19. Keeping all of these in mind, authors have deployed an
interactive cross-platform (web/mobile) application INDIA COVID-19 TRACKER for the ease of the users,
especially in India.
This dashboard is featured with all the real-time attributes about the novel coronavirus disease and its
measures and controls. The system purposely aims to maintain the digital protection of the society, create
public awareness, and not create any agitation situation among the individuals of the society.
Movie Recommendation Systems using Sentiment
Analysis and Cosine Similarity
Authors: Raghav Mehta and Shikha Gupta
Published: January 2021

As Artificial Intelligence and Machine Learning is growing at a rapid rate over the past few years, so is the
amount of data increasing exponentially on the internet. Due to this people find it difficult to choose the exact
information they are looking for , learners find it difficult to suggest users exactly what they require. Here
comes Recommendation Systems into picture to guide users towards the information according to their
preferences. In context of Recommendation of Movies and TV shows on Online Streaming platforms ,this
paper is aimed to explain making and implementation of Movie Recommendation Systems Using Machine
Learning Algorithms, Sentiment Analysis and Cosine Similarity
Classification Airbrone LiDAR Point cloud Data
Authors: Naga Madhavi lavanya Gandi
Published: January 2021

Land cover classification information plays a very important role in various applications. Airborne Light
detection and Ranging (LiDAR) data is widely used in remote sensing application for the classification of land
cover. The present study presents a Spatial classification method using Terrasoild macros . The data used
in this study are a LiDAR point cloud data with the wavelength of green:532nm, near infrared:1064nm and
mid-infrared-1550nm and High Resolution RGB data. The classification is carried in TERRASCAN Module
with twelve land cover classes. The classification accuracies were assessed using high resolution RGB data.
From the results it is concluded that the LiDAR data classification with overall accuracy and kappa coefficient
85.2% and 0.7562.
RFID Based Attendance System
Authors: Arpit Saxena and Poonam Juneja Ajay Joshi, Aman Ahmad
Published: January 2021

RFID is an acronym for “radio-frequency identification” RFID technology is an automatic wireless
identification system that works by the help of two components: a card and a reader. Using the RFID
technology, the conventional system of taking attendance can be completely transformed to be more in line
with strides in digitalization. This system will help the authorities manage the attendance system in a more
methodical, efficient and time saving manner. The proposed system has been implemented through a
prototype that has proved the effectiveness of the concept in easing the logistics of taking attendance as a
result of the automation due to the use of the RFID technology. The design of the system is simple, cost
effective and agile making it a good candidate for commercial and academic purposes.
Preparation of Gelatin Film Incorporated with Extracts
of Hemigraphis Colorata Used as Wound Dressing
Authors: Logeshwaran. V, Kousalya. N and Dr. Arun. P Sandhiya. S, Sabarinath. K, Ishwarya. R
Published: January 2021

Hemigraphis coloratais a medicinal plant originates from the tropical regions of kerala and its native is
from the sides of Malesia. It is a perennial herb mostly grown as ornamental plant. It is a tribal plant of the
tribes of Kerala. It is commonly called as “murikooti or muryanpacha”H.coloratais used as herbal ointments
to cure cut wounds, ulcers and most importantly bleedings. It has many valuable properties like
anti-microbial and anti-diabetic activities. It acts as an anti oxidant and exhibit free radical scavenging
activity. This study is carried out to prepare a gelatin film using the extracts of H. colorata used as wound
dressing.
El derecho a la formación y a la cualificación profesional en el empleo doméstico
Authors: Grau Pineda Carmen
Published: January 2021

Que el tema del empleo doméstico este últimamente de moda no es en modo alguno casual. Múltiples son las variables que han influido en ello, pero es fácil entender que con la incorporación masiva de las mujeres al mercado de trabajo haya sido preciso redistribuir las tareas y cuidados intrafamiliares entre los miembros de cada unidad familiar o “externalizarlos” y acudir a la prestación de servicios por personas ajenas a la misma. En este contexto general, es de gran utilidad revisar el papel que la formación y cualificación profesional tiene en la dignificación, valorización y, por tanto, visibilización de este trabajo, de este sector y de un colectivo de trabajadoras vulnerables como pocos. Y, para llevar a cabo tal labor, ha decidido estructurarse esta aportación intentando dar respuesta a tres preguntas concretas: ¿Por qué es el sector de empleo doméstico un sector emergente?, ¿existe un derecho laboral a la formación profesional para este colectivo?, ¿de qué formación se dispone, por qué no se demuestra eficaz y quién es el responsable de ello?
Europa social: cuestiones para un futuro debate
Authors: Pons Carmena María
Published: January 2021

El presente trabajo tiene por objeto abordar determinadas cuestiones que, a juicio de la autora, deberían ser tratadas en un futuro debate sobre la Europa social. Para ello, se presentará, como punto de partida, la situación actual del denominado Modelo social europeo a partir de un recorrido por la configuración de las diferentes técnicas de creación del derecho social europeo: armonización de las legislaciones, diálogo social, método abierto de coordinación y “constitucionalización” de los derechos sociales. Una segunda parte del trabajo se dedicará a plantear ciertos temas concretos que deberían ser objeto de tratamiento en el futuro, entre ellos, los siguientes: la reformulación del art. 153 TFUE, el establecimiento de un marco jurídico facultativo sobre negociación colectiva transnacional, la modificación de las directivas sobre información, consulta y participación interna de los representantes de los trabajadores en las empresas, el potencial del método abierto de coordinación, y la adhesión de la Unión Europea tanto al Convenio Europeo de Derechos Humanos, como a la Carta Social Europea revisada.
El ingreso mínimo vital y el derecho a la asistencia social de la Carta Social Europea
Authors: Dalli María
Published: January 2021

En este artículo se analiza el Ingreso Mínimo Vital (IMV) desde la perspectiva de los derechos humanos y, en concreto, desde los estándares exigidos por el derecho a la asistencia social reconocido en la Carta Social Europea. El objetivo es valorar si el IMV cumple o no con las exigencias del derecho a la asistencia social tal y como ha sido reconocido en el artículo 13 de la Carta Social Europea, de acuerdo con la doctrina consolidada del Comité Europeo de Derechos Sociales del Consejo de Europa. El análisis de la regulación del IMV teniendo en cuenta las implicaciones de este derecho permite concluir que, a pesar de los importantes avances realizados, algunas mejoras son todavía necesarias como la cobertura de los jóvenes menores de 23 años, la provisión de asistencia social básica para inmigrantes en situación irregular y en casos de sanciones o un mayor desarrollo de las medidas de inclusión. La sociedad civil y expertos internacionales de derechos humanos asimismo recomiendan una mayor flexibilidad del enfoque de la activación, el pago del ingreso en cuentas separadas o al principal cuidador, y la garantía de mecanismos presenciales de solicitud para luchar contra la brecha digital.
Beneficios del uso de dexametasona en paciente oncológico COVID-19 asintomático.
Authors: Guarnizo Chávez Andrés Joaquín
Published: January 2021

El propósito de este artículo es presentar un caso clínico de una mujer adulta de 44 años con diagnóstico establecido de cáncer de mama, y posible metástasis pulmonar; que recientemente también diagnosticada de SARS COV19, manteniéndose asintomática de este último. Sin embargo; por falta de tratamiento quimioterapéutico oportuno, se evidencia deterioro de la calidad de vida debido a disfagia secundaria por hipertrofia ganglionar oncológica. Como parte del tratamiento adyuvante se le receta esquema de dexametasona durante los quince días de aislamiento, evidenciando no solamente mejoría en la deglución de alimentos, sino también en valores de oximetría de pulso.
PENGARUH MODEL PEMBELAJARAN COOPERATIVE TIPE NUMBERED HEAD TOGETHER (NHT) TERHADAP HASIL BELAJAR BIOLOGI MATERI KINGDOM ANIMALIA PADA SISWA KELAS X SMA NEGERI 4 MAROS
Authors: Diana Nurdiana
Published: January 2021

Pengaruh Model Pembelajaran Cooperative Tipe Numbered Head Together (NHT) Terhadap Hasil Belajar Biologi Materi Kingdom Animalia Pada Siswa Kelas X SMA Negeri 4 MAROS, (dibimbing oleh A. Muhajir Nasir dan Novalia Tanasy).

Penelitian ini termasuk penelitian Pre-Experimental Designs. Penelitian ini bertujuan untuk mengetahui bagaimana pengaruh Model Pembelajaran Cooperative Tipe Numbered Head Together (NHT) terhadap hasil belajar biologi materi kingdom animalia pada siswa kelas X SMA Negeri 4 Maros. Variabel bebas dalam penelitian ini adalah Cooperative Tipe Numbered Head Together (NHT) sedangkan variabel terikat dalam penelitian ini adalah hasil belajar biologi. Pengambilan sampel dilakukan dengan menggunakan teknik Purposive Sampling. Sampel penelitian ini adalah siswa kelas X MIPA 4 sebagai kelas Eksperimen. Data dianalisis menggunakan Analisis Uji Deskriptive, Normalitas, dan Ngain dengan menggunakan SPSS versi 16. Pada penelitian ini dapat disimpulkan bahwa ada pengaruh penggunaan Model pembelajaran Cooperative Tipe Numbered Head Together (NHT) terhadap hasil belajar biologi. Hal ini juga dibuktikan dari hasil perolehan pengujian hipotesis Ngain dengan menggunakan Gain ternormalisasi One Sample t-test  yang diperoleh nilai thitung = 2.919 dengan nilai-p = .008 < α =0,025 berarti terdapat perubahan yang signifikan. Pada posttest juga memperlihatkan bahwa 21 dari 24 peserta didik (87,5%.) telah mencapai nilai Kriteria Ketuntasan Minimal (KKM) pada mata pelajaran biologi di SMA Negeri 4 Maros . hasil penelitian ini menunjukkan bahwa bahwa penggunaan model pembelajaran Cooperative Tipe Numbered Head Together (NHT) berpengaruh terhadap hasil belajar biologi materi Kingdom Animalia pada siswa kelas X SMA Negeri 4 Maros
MENINGKATKAN KINERJA GURU IPA DALAM MENETAPKAN NILAI KKM MELALUI TEKNIK COACHING MODEL GROW ME
Authors: Arifin Ardiana
Published: January 2021

Tujuan dari penelitian ini adalah untuk membantu mengembangkan kompetensi guru maka perlu dilakukan suatu model pembinaan yang bersifat sistematis dan menyeluruh sehingga guru dapat meningkatkan kompetensinya, terkhusus dalam menetapkan KKM. Penelitian ini telah dilakukan selama 2 bulan, mulai dari bulan September hingga Oktober 2017. Dalam penelitian tersebut, 19 guru sasaran dalam penelitian ini terlibat aktif dalam kegiatan diskusi dan sharing pengalaman dengan guru IPA yang lain dalam wadah MGMP IPA. Untuk memaksimalkan pemahaman mereka maka penulis memberikan perhatian, bimbingan, dan pendampingan yang lebih banyak dalam menetapkan KKM. Penelitian tindakan sekolah dilaksanakan melalui dua siklus dengan indikator keberhasilan 85% guru sudah dapat menetapkan KKM. Hasil dari penelitian ini menunjukkan adanya peningkatan yang signifikan. Pada siklus I baru tercapai 65,4 %, dan setelah siklus II menunjukkan peningkatan hingga 96,4 % kemampuan guru menetapkan KKM. Dengan demikian maka diharapkan model pembinaan melalui pendampingan di kegiatan MGMP dapat digunakan untuk membantu dan meningkatkan kemampuan guru dalam mengatasi masalah lainnya
THE IMPACT OF OVERCONFIDENCE BIAS ON PERSONAL INVESTMENT DECISIONS: THE CASE OF NORTH MACEDONIA
Authors: Hadzimustafa Shenaj , Shabani Nermine
Published: January 2021

The "Financial Behavior" in the field of "decision making" is the topic that awarded the economist Richard H. Thaler the Nobel Prize in 2017. According to him, after many investigations made on human decisions, it is noticed that they often depend on nature, intuition, habits, cognitive biases, emotional biases which lead the investor to wrong decisions. Given that the investments play an important and central role in the economy, the main purpose of the paper is to analyze the investment decision making process based on emotional bias, or more specifically the overconfidence bias. This study captures the impact of gender, and level of education on overconfidence during investment decision making in North Macedonia. The results show that investors' decisions were significantly influenced by the overconfidence bias. Although men and women are found to be overconfident, studies have shown that the degree of overconfidence varies among them and men are more overconfident than women. Also, overconfidence increases with the level of education. Based on the results certain recommendations are provided in order to assist future investment decision-making processes by notifying and eliminating the overconfidence bias identified during this research as a key factor leading to wrong and failing, non-rational investment decision making.
THE LINK BETWEEN PRODUCTIVITY AND LABOUR SHARE – THE CASE OF NORTH MACEDONIA AND SLOVENIA
Authors: Trenovski Borce , Kozeski Kristijan , Merdzan Gunter
Published: January 2021

The large divergence between productivity and workers’ incomes has been becoming a reality in most countries, not just in the United States after 1980s, where labour productivity grew faster than real wages and employment. The breakdown according to Brynjolfsson and McAfee (2014) is due to technological progress, according to Bivens and Mishel (2015) the growing inequality and according to Baker (2007) the declining labour share in GDP. The main goal of this paper is to find out if the global trend of “The Great Decoupling” between productivity and labour share is a real process in the case of the countries analyzed from the Southeast Europe region. Given that Slovenia is among the most developed countries, while North Macedonia belongs to the group of developing countries that in these stages of development rely on foreign capital and cheap labour, we examine whether the process of “The Great Decoupling” between productivity and labour share is a reality in both countries. From the analysis of the trend of the movement of the average labour productivity of these two countries, it can be concluded that in both countries there is a trajectory of the movement of the labour productivity. Also, from the trend of the movement of the share of labour income and labour productivity in the case of Slovenia and North Macedonia it can be concluded that they indicate the existence of a large gap, i.e. divergence in the trajectory of motion. Also, the gap between labour productivity and the share of labour income in GDP on the example of North Macedonia, if compared to the example of Slovenia is of lower intensity. Finally, based on the results obtained from the conducted econometric analysis, we determine whether there is a need for further research or the phenomenon is a temporary deviation in the dynamics of the gap between labour share and labour productivity.
Optimization of The Best Line-up in Football using Binary Integer Programming Model
Authors: Mahrudinda Mahrudinda , Supian Sudrajat , Subiyanto Subiyanto , Chaerani Diah
Published: January 2021

This paper aims to find the formation with the best line-up of the Liverpool FC football team in the English Premier League in the 2020/2021 season. Researchers used binary integer programming (BIP) modeling to determine optimum solutions. The data used for this optimization is the rating value of the players recorded in the performance data from the previous matches. The optimum result of this problem is the selection of variables that are valued at 1, namely {𝑥1,𝑥4,𝑥6,𝑥8,𝑥11,𝑥18,𝑥21,𝑥28,𝑥34,𝑥37,dan 𝑥39 } for formations 4-3-3 with a maximum value of 82.47, and variables {𝑥1,𝑥6,𝑥7,𝑥8,𝑥11,𝑥14,𝑥16,𝑥29,𝑥31,𝑥32, dan 𝑥42 } for 4-2-3-1 formations with a maximum value of 80.04. The 4-3-3 formation is more effective because it has a higher maximum rating than the 4-2-3-1 formation. 4-3-3 formation is an attacking formation with a higher intensity of attack and faster than 4-2-3-1 formation that tends to defend moderately.