bluuebunny/crossref_metadata_2025 huggingface dataset:
Cell Structure Improvement in Melt Processed Pure Aluminium Foams by Pre-treatment of Foaming Mixture
Authors: Gandhapu Sandeep , Mahajan Aryan , Sasikumar S
Published: August 2022

This work aims to evaluate the cell structure of aluminium foams blown by using foaming mixture subjected under ball milling and heat treatments. This paper presents the study on the effects of various pre-treatment of foaming mixture on the cell structure of foamed aluminium (Al) fabricated via melt route. This study also demonstrates how the melt foaming method can be used to fabricate small-sized Al foams. Prior to foaming the Al melt, the foaming mixture containing TiH2 and Al was pre-treated by ball milling and heat treatment in four different ways. The foaming mixtures were characterized by X-ray diffraction (XRD), Energy Dispersive X-ray Analysis (EDAX) and Scanning Electron Microscope (SEM) techniques. The macrostructure of the foams has been characterized by optical scanner and ImageJ software. The mechanical properties of the foam samples were evaluated by quasi-static compression test. XRD results revealed the TiO2 and Ti3O phases formed in the heat treated TiH2 powders. SEM micrographs showed the morphological changes occurred to Al and TiH2 powders and their distribution before and after ball milling. EDAX reported the chemical composition of elements present in the foaming mixtures. Ball milled foaming mixture not only increases the number of TiH2 particles, but also reduces the hydrogen content during the foaming stage. The foam produced from heat-treated and ball-milled foaming mixture shows better cell size & structure with good homogeneity. However, the mechanically mixed foaming mixture produce foam with good strength and energy absorption capability.
Tribological Characteristics of Stellite Hard faced Layer on Mild Steel
Authors: Venkatesh B. , Anil Kumar Reddy C. , Raghupathi
Published: August 2022

Hardfacing is the oldest method of surface engineering for obtaining diverse characteristics and extending the life of materials. Even with typical use, all metal parts will corrode over time. As a result, they may lose their functioning, necessitating the purchase of a new part. This may occur more commonly in particular industrial applications, such as mining or agriculture. Hardfacing is a great solution for any metal element that is likely to wear over time. Hardfacing is typically done to worn rebuilt gear, but it can also be applied to new equipment to make it more wear-resistant. Hardfacing parts from older equipment can save you anywhere from 25 to 75 percent on replacement costs. Hardfacing can help extend the life of parts on latest equipment by up to 300 percent. Here chosen hardfacing technique as Tungsten Inert Gas Welding (TIGW) process to deposit stellite electrodes on base metal (i.e mild steel). The works is focus about deposit the hardfacing layers on mild steel specimens and perform comparative study of stellite -1 and stellite-12 hardfaced layers applied on mild steel specimens. The Objective of the project is to obtain better wear characteristics, hardness and better micro- structural properties of material.
Electrochemical behavior of friction stir welded joint of ultra-low carbon steel
Authors: Koley Ishita , Kundu Sukumar
Published: August 2022

In this study, friction stir welding of ultra low carbon steel was performed at tool rotational speeds in the range from 300 to 750rpm with 150rpm increments at 60mm/min fixed traverse speed. Throughout study was performed on macro and micro structures in order to determine the several welded zones for example stir zone, thermo-mechanically affected zone, and heat-affected zone. Microhardness profiles were performed along the welded joint's cross section and the utmost hardness was obtained at stir or nugget zone as compared to the other zones of the welded joints. The hardness values on the stir zone decreases with rise in tool rotating speed. Electrochemical study was investigated in 3.5%NaCl electrolyte solution. Corrosion rate is maximum (~27MPY) at 300 rpm stir zone and minimum value (~0.3 MPY) obtained at heat affected zone at 750rpm welded sample.
Comprehensive Analysis for Material Selection: Performance Evaluation for a Special Purpose Flexure
Authors: Bhoyar Suraj , Bhojwani Dr. Virendra , Sanap Dr. Sudarshan
Published: August 2022

Considering a cryocooler for space applications, a special type of a flexure spring is fitted to assist the compressor motor and a displacer for liner motion thereby removing vibrations, frictional losses, and wear & tear. In the context of the critical application, the important physical parameter i.e., fatigue life of the flexure spring matters the most so that cryocooler does not fail during the operation. The present research study is an attempt to analyze the vital factors and attributes to determining the suitable material for accomplishing finite-fatigue life for the special flexure spring. A comprehensive analysis for material selection was conducted using the material options viz. a] AISI 304 Stainless Steel b] Beryllium Copper UNSC17200 c] Grade 5 Titanium (Ti-6Al-4V-3.7165-R56400) and d] AMPCOLOY® 944. Further, the materials stated were compared to their respective S-N curves. To decode the flexure spring’s performance evaluation, the parameters viz. load stresses, stiffness, displacement, geometrical configuration, etc. were analyzed using the Finite Element Analysis (FEA) package.
Microwave casting of stainless still through microwave hybrid heating
Authors: Ram Vishal Kumar , Nandwani Sahil , Vardhan Sachit , Bahl Shashi , Samyal Rahul , Bagha Ashok Kumar
Published: August 2022

A microwave is defined as a form of electromagnetic radiation. The microwave has an electric-field and magnetic field and those fields are orthogonal to each other and within the frequency range of 0.3-300 GHz. Microwave casting is a novel technique to cast different materials using microwave hybrid heating (MHH). The microwave casting is divided into two parts, such as in-situ and ex-situ. In this paper, the in-situ microwave casting process is used to cast the SS316bulk metal. A domestic microwave applicator has a frequency of 2.45 GHz with a power capacity of 900W. Stainless steel was used as a powder form having a particle size of 40-80 μm. SEM, EDS, and micro-hardness of the casted samples are carried out to validate the casting of SS316 bulk metal. The modal analysis of casted beam using experimental OROS software technique to measure the natural frequencies, corresponding damping ratios, and damping capacity of the casted SS316 samples.
Optimization of Pulsed Nd:YAG Laser welding for Nickel and Copper with ANFIS model
Authors: Kadale Sanket P. , Shinde Prakash S.
Published: August 2022

Nowadays the demand of joining dissimilar materials have increased. Pulsed Neodymium doped yttrium aluminium garnet (Nd:YAG) laser welding is in demand because of its applicability in various sectors like Automobile, Electrical and Electronic Industries. In the current investigation pulsed Nd:YAG laser welding was used to weld Nickel and Copper samples. The experimentation was conducted to study the effect of process parameters on the performance of welding and to validate numerical model. The optimization technique was employed to get optimum process parameters. The main parameters of process were current, laser focus, pulse width and frequency. The main responses plotted were Ultimate tensile stress (UTS), Hardness and Heat Affected Zone (HAZ). To perform effective experimentation design of experiment (DOE) was carried out using Taguchi method with four factors having three different levels. After experimentation Analysis of Variance (ANOVA) was employed for analysis and optimization of the effect of different parameters on the responses. Then, the Adaptive neuro fuzzy inference systems (ANFIS) model was being developed for factors and responses to get predicted results. The predicted results obtained from ANFIS model were close to experimental results.
Analysis of Phase Change Material used as Thermal Energy Storage Unit in Catalytic Converter.
Authors: Patil Vaibhav D. , Pise Gargee , Nandgaonkar Milankumar R.
Published: August 2022

Phase change Material(PCM) is widely used to heat storage applications. In this study PCM is used in the catalytic converter application to improve the performance of catalytic converter by maintaining the temperature above the light off temperature. Catalytic converter is inefficient at lower temperature or below the light off temperature the conversion efficiency is very low and practically it is zero. Using PCM conversion efficiency of catalytic converter is increased. PCM is placed above the substrate to absorb the heat from the exhaust gases which are leaving to the atmosphere in order to maintain the substrate temperature above the light off temperature. When the temperature is high at substrate then conversion of pollutants is better. PCM Store the heat by changing the phase from solid to liquid and return the heat to substrate by partial solidification. In this paper, performance of PCM (Mg70Zn24.9Al5.1) which is a eutectic alloy used for high temperature applications was investigated at various loading conditions by doing the simulation on catalytic converter for melting and solidification of PCM and validate the results with experimental work. The melting of PCM domain is simulated using ANSYS fluent 2019 R3 software. The assumptions used for the numerical study, methodology of the work and specification of software is also discussed in this paper. The contours of melting fraction of PCM at regular interval for different loading conditions (i.e. 0%, 50%, and 100% load) are represented for total melting period of the PCM.
Effect of temperature on structural and magnetic properties of Co and Mg doped M-type hexaferrites
Authors: Vyshak Menon M , Srivastava A K
Published: August 2022

Using the sol-gel auto combustion method, M-type barium hexaferrite of composition Ba0.6Co0.4Mg0.4Fe11.6O19 was prepared. The precursor was divided into three parts and heated at three different temperatures i.e., 9000C, 10000C, 11000C. The structural samples were investigated using an XRD analysis. The variation of crystallite size and lattice constant to temperature was studied from the XRD data. The functional groups attached to the samples were investigated using Fourier transform infrared spectroscopy. To understand the topography and elemental composition, the sample was analysed using a field emission-scanning electron microscope (FESEM). A VSM instrument was employed to investigate the magnetic property of the three samples. Magnetic parameters such as coercivity, saturation magnetization, magnetic retentivity, anisotropy constant, etc were calculated and tabulated.
Mechanical Characterization and Fabrication of Banana and Pineapple Fibers
Authors: Anil Kumar V. , Sai Neeraj T. , Meghana Y.
Published: August 2022

A composite material is made up of two or more materials with differing properties that are combined to enhance material properties. Various natural fibers are abundant in India such as seed hairs like cotton, flax, hemp leaf fibers, sisal, coconut, jute, pineapple, luffa, etc. Since natural fibers stand-alone don't have distinct mechanical properties. To attain good mechanical properties and to explore worth-added applications. The evolvement of natural fiber composites in India is to avoid the depletion of resources. The reason for the desirability of this field over the traditionally used synthetic fiber is that natural fibers have low density, high toughness, are environment friendly, fully biodegradable, renewable, and low cost. The biodegradability of plant fibers can impart a healthy ecosystem while their low cost & high performance fulfill the economic interest of industries. The purpose of this paper is to develop a new natural fiber composite with banana stem fibers and pineapple fibers. Resins and hardeners are chosen depending on the mechanical properties of the fibers, and fabrication was done accordingly. Finally, conclusions are drawn after Mechanical Testing of the composites. The properties of the composites are discussed.
Numerical study to investigate the influence of CNTs on delamination resistance in broken ply carbon/epoxy composites
Authors: Rao Chukka Atchuta , Krishna Murthy K S R , Chakraborty Debabrata
Published: August 2022

In fibre reinforced polymer (FRP) composite laminates subjected to low velocity impact, one of the common mode of failure is ply breakage followed by interfacial delamination at the site of ply break. Improving the delamination resistance at the interface is therefore important and the present work examines quantitative understanding of how the addition of CNTs to epoxy might enhance the resistance to such delamination at the interface. A laminate made of plies with CNT-epoxy as the matrix and carbon fibre as the reinforcement has been considered to be broken through the full width. A full three dimensional FE analysis was carried out for such a carbon/CNT-epoxy laminate for different wt% of CNTs. Resistance to delamination has been assessed by computing critical strain energy release rate (Gc
) using quadratic stress criterion (QSC) and virtual crack closure integral (VCCI). From the results, by adding CNTs to epoxy, a significant improvement in the delamination resistance could be observed. However, the improvement is till a certain specific CNT wt% and adding CNTs further leads to a significant reduction in delamination resistance. In addition, the effect of various factors such as fiber orientation of the adjacent continuous ply and resin layer thickness on critical strain energy release rate (Gc
) have been studied. The results show that Gc
also depends upon the fiber orientation of the adjacent ply and on the resin layer thickness. As the resin layer thickness increases, a significant increase in Gc
is observed.
Study of Mechanical Properties and Hard Water Absorption Behavior of Water Hyacinth Reinforced Starch Composite
Authors: Wilson Delma , Anto Changel , Biju CV
Published: August 2022

In this paper an attempt has been made to prepare bio-composite using water hyacinth fiber as reinforcement and potato starch as matrix. The renewable resource, water hyacinth is used as the major composition of the proposed bio-composite. Since the bio polymer can contribute better mechanical properties, it can act as a substitute for the existing synthetic fibers. The biodegradable, environmentally friendly and less expensive characteristics of the bio composite, find it suitable for automotive and conventional industrial applications. The effect of the fiber length ranging from 10 mm to 40 mm verses tensile strength and bearing strength are included in the research work. The simplest and most effective hand layup method is used to prepare the bio fiber from water hyacinth after duly seasoning the raw stems in the controlled environment. The bio composite made up of 70% potato starch as matrix is dissolved in sufficient amount of water in which 30% of glycerol is added to the reaction mixture. Magnetic stirrer capable of generating variable speed ranging from 800 rpm to 1200 rpm, with inbuilt heating mechanism made up of stainless steel material is used to prepare the reaction mixture. The stirring process is continued till the required viscosity is obtained. The specimen is kept in the electric oven and the water content is removed. Before investigating the mechanical properties, the specimen was compressed to 600 psi (≈ 42 bar) pressure. Using Universal Testing Machine (UTM) the tensile strength of the composite was investigated in the ambient temperature and pressure. The specimens- with and without reinforcement were studied to find the effect of water absorption capability which is function of nature solvent and matrix. Based on the experimental results, it was concluded that bio composite is a potential candidate to serve the needs of the industry.
Structural and spin-dependent electronic properties of triangular/zigzag boron nitride nanowires
Authors: Jha Kamal K , Jain Sandeep Kumar , Jaiswal Neeraj K , Srivastava Pankaj
Published: August 2022

By Employing first-principles investigations within the density functional theory, we have investigated the structural stability and spin-dependent electronic properties of boron nitride nanowires (BNNWs) in triangular and zigzag geometry. Analysis of binding energy reveals that both types of NWs are thermodynamically stable. Furthermore, zigzag NW is energetically more favorable than the triangular one by 0.23 eV. Both the examined structures exhibited semi-metallic character for spin compensated calculations. However, upon consideration of spin polarization, the opening of a bandgap has been witnessed for both the triangular and zigzag NWs. Remarkably, the triangular and zigzag NWs prefer a magnetic ground state robust to the thermal excitation energy of 26 meV. Interestingly, the spin-assisted band gap is significantly lower for the spin-up electronic states than that of spin-down electrons. It indicates that the charge transport through NWs would differ for spin-up and spin-down electrons. Present findings constitute the possibility of application in the emerging spin-based nano-electronic devices.
Exploring the Effect of Dispersed Phase on the High Strain Rate Mechanical Response of Nanosilica Dispersions
Authors: Bhalla Neelanchali Asija , Chouhan Hemant , Yadav Rishi Kumar , Bhatnagar Naresh
Published: August 2022

Shear Thickening Fluids (STFs) constitute a special class of materials which exhibit phase transition from low to high viscosity state when exposed to shearing forces, particularly, when the applied shear rate exceeds a critical value. The last decade has witnessed a mutual symbiotic relationship between STF and high-performance fabrics such as Kevlar®, Dyneema®, Ultra High Molecular Weight Polyethylene (UHMWPE) etc., to produce new light weight and flexible protective materials systems with enhanced knife, stab and ballistic resistant properties than the existing ones. In this study, we explore the effect of particle shape and size on the high strain rate dynamic response of nanosilica dispersions. Shear thickening fluid (STF) was synthesized using fumed silica and spherical nanosilica particles, comprising the dispersed phase, whereas PPG400 (Polypropylene Glycol) was used as the dispersion medium. Ultrasonic homogenization technique was used for the synthesis of STF. The low strain rate rheological characterization was conducted on MCR302 rheometer at 25°C, whereas the high strain rate characterization was performed on inhouse designed and developed SHPB (Split Hopkinson Pressure Bar) apparatus. Fumed silica (FS) particles possess high specific surface area owing to their fractal structure. Therefore, their low molecular weight dispersions exhibit shear thickening behavior thus making them potential candidates for liquid body armour applications. On the other hand, spherical silica dispersions exhibit shear thickening behavior in high phase volume concentrations. Experimental studies showed that spherical silica based STF dispersions exhibited enhanced shear thickening in the low strain rate domain, as well as better mechanical response in terms of higher peak stress under high strain rate compressive loading conditions, during SHPB testing, in comparison to their fumed silica counterpart. Thus, it can be inferred that the mechanical response of nano-silica dispersions is influenced by the shape of the particles constituting the dispersed phase.
Turning of Aluminium Composites: Characteristics and Future Prospects
Authors: Gupta Vivudh , Singh Pawandeep
Published: August 2022

Aluminium matrix composites have widespread applications in different industrial areas including automobile and aerospace owing to their improved mechanical and tribological properties over conventional monolithic materials. As such, machining of these metal matrix composites is an important aspect to be studied in order to manufacture desired components with close tolerances. Presence of hard abrasive ceramic reinforcements in composites increases the chance of tool wear and hence, increased machining cost during conventional machining process. In order to improve machining characteristics of aluminium composites, machining is carried out using specialized carbide tools (both coated and uncoated), polycrystalline diamond inserts, CVD diamond coated inserts, etc. This paper presents a state-of-the-art review on turning of aluminium composites. Factors affecting machinability like content, size, and morphology of reinforcement along with matrix hardness are discussed. Effect of process variables such as cutting speed, feed rate, depth of cut, etc. on response variables such as tool wear, surface finish, cutting forces, cutting temperature, etc. has been highlighted. Moreover, failure mechanisms involved in turning process occurring due to debonding, plastic deformation, particle fracture, etc. are deliberated in this study. Various modelling and optimization studies in this area are discussed in detail as well. Furthermore, scope for future work in this area including sustainable machining is also elucidated.
Linear, nonlinear and post buckling analysis of a stiffened panel with cutouts
Authors: Sohan R , Likith S , Sai Jeevan , Vadlamani Shashank
Published: August 2022

Stiffeners are typically used to strengthen structures that rely on plates for load bearing. Such structures are subjected to various kinds of in-plane and out-of-plane loading over its lifespan. Furthermore, cutouts in aerospace structures are considered for practical and design reasons. In the present paper, finite element method is used for the analysis of a flat rectangular stiffened plate. Static analysis is performed on three panels with different stiffener cross sections (I section, hat section and rectangular section), and the panel with the least deformation and stress is chosen for further buckling analysis. Linear, non-linear and post buckling analysis of the selected stiffened panel under in-plane compression is carried out and its load and end – shortening response is evaluated till collapse. Furthermore, the effect of rectangular and circular central cutouts on the buckling behaviour of the stiffened panel is investigated. By varying the dimensions of the cutouts, a parametric study on buckling and ultimate collapse strength is performed. The study takes into account an aluminium alloy with isotropic material properties and a carbon fibre reinforced polymer (CFRP) with orthotropic material properties.
FEM modelling of magnetoelectric coupling in (2-2)LSMO/ P(VDF-TrFE) polymer composite
Authors: Koner S , Sumit  , Shukla R , Majumder S K , Satapathy S
Published: August 2022

Strain mediated magnetoelectric (ME) coupling effect has been investigated in bilayer structure of LSMO/P (VDF-TrFE) nanocomposite in the transverse ME mode. In the transverse mode, Finite Element Method (FEM) based small signal analysis has been performed by the COMSOL Multiphysics 6.0 software. La0.7Sr0.3MnO3(LSMO)/P (VDF-TrFE) nanocomposite (2-2) has been prepared by gluing LSMO pellet with P(VDF-TrFE) polymer film. This bilayer structure shows multiferroic property at room temperature. Simulated FEM modelverifies the magneto-strictive property of LSMO layer and explained the experimental results.Experimental and simulated ME coupling coefficient are found to be very close to each other.
Investigation regarding the Replacement of Composite Material Leaf Springs with Spring Steel Leaf Springs in Automotive Vehicles: A Review
Authors: Aggarwal Shivam , Aggarwal M. L. , Verma Krishan
Published: August 2022

Leaf Springs finds vast applications in different types of mechanical systems. In spite of lot of research, spring steel leaf springs finds a lot of applications in all types of heavy vehicle. Composite leaf springs represent some application of composite materials in the field of automotive lightweight materials. However, the composite material finds limited applications in the form of mono leaf but for multi leaf in heavy vehicles, its application is rare due to certain issues including delamination. Stiffness and damping properties are the critical parameter of composite leaf springs and are closely related to the handling stability and ride comfort of automobiles. Composite leaf spring with variable parameters may be used in the automobiles to replace the conventional steel leaf springs, mainly due to the high load-bearing capacity. The optimum structural design of composite leaf spring may be calculated using an effective algorithm. The mechanical properties of composite leaf spring is analyzed with experimental or computational approach or both. This paper investigates addresses various issues regarding the replacement of composite material leaf springs with spring steel leaf springs in light and heavy weight automotive vehicles.
Theoretical Estimation of Elastic Characteristics of Natural Reinforced Composite- A Comparative Analysis
Authors: Nejkar Harshal , Swamy K. B. M.
Published: August 2022

Natural Fiber composites are among the potential materials due to their low cost, biodegradability, environmental concerns, and other merits. This paper investigates various theoretical methods to evaluate the elastic behavior of Bamboo fiber-reinforced Epoxy composite and compare it with available experimental data. To compute elastic properties for different fiber volume fractions, prominent micromechanical models such as the Rule of mixing, Halpin-Tsai, Chamis, Unified Bridging, and Elasticity approach, as well as the most current FE homogenization simulation, are employed. FE simulation results from the advanced ANSYS 21.0 material designer module incorporating different Representative Volume Elements (RVE) (Square, Diamond, and Hexagonal) are compared with these models. Through this, a comparative analysis is provided for the validity of different models in predicting the elastic behavior of similar natural fiber-reinforced composites.
An initial study on the impression creep behaviour of stir-cast GNP reinforced AA6061 composite (AMMC)
Authors: Khokhar Ostin , Khajuria Akhil , Bedi Raman
Published: August 2022

Impression creep testing technique is used to screen out creep behaviour of materials as it is relatively faster method, requires small volume of the specimen, and is relatively material non-invasive technique when compared to conventional uniaxial tensile creep test method. This technique also possesses the benefit of maintaining constant stress throughout the experiment because a flat cylindrical indenter is used to apply load on the specimen. Owing to commercial unavailability of the materials under development such as metal matrix composites (MMC), the impression creep testing approach for such materials becomes a best method. In present work, creep behaviour of stir-cast graphene nanoplatelets (GNP) reinforced AA6061 composite (AMMC) is studied by using impression creep tests. The AMMC was prepared by adding GNPs in AA6061 through stir casting process by melting the alloy up to 1073 K. The impression creep experimentation included stress levels of 140 MPa, 170 MPa, and 200 MPa at a temperature of 573 K, 603 K and 633 K. The tests were conducted at constant stress by varying the temperature and vice-versa in vacuum. Two distinct regions i.e., primary and secondary/steady-state were observed and minimum creep strain rate was obtained in steady-state region. Tertiary region was absent, since the load/stress applied was compressive. During the experiment, depth of indentation of 0.03 mm to 0.14 mm was produced in the specimen. The microstructure of the composite has been analyzed using optical microscope and scanning electron microscope (SEM) to correlate with impression creep behaviour of the studied materials.
Recent advancements in the production of hybrid metal matrix composites (HMMC): A Review
Authors: Anand Anshu , Tiwari Sanjiv Kumar
Published: August 2022

Industries are currently concentrating on materials that can replace monolithic metals and alloys. The transition from monolithic to advanced materials has resulted in the development novel materials. These materials have better properties than traditional ones, such as high-temperature resistance, increased specific stiffness, increased specific strength, and other mechanical and tribological properties. Metal matrix composites (MMCs) are currently gaining more attention as a critical engineering material due to their superior characteristics over monolithic materials. These MMCs have wide applications in the automotive, aerospace, defense, and marine industries. This makes them worthy of further investigation as potential alternative materials. This paper attempts to review the current advances in producing hybrid metal matrix composites (HMMCs). In addition, the article covers the impact of matrix material selection, reinforcement, and processing techniques on the production of metal matrix composites.
An investigation on microstructure and mechanical behaviour of aluminium hybrid metal matrix nanocomposite fabricated through electromagnetic stir casting process
Authors: Anitha P , Srinivas Rao M
Published: August 2022

This study focuses on the microstructure characteristics and mechanical properties of unreinforced and reinforced ceramic materials titanium diboride (TiB2) and graphite (Gr). Aluminium hybrid metal matrix nanocomposites reinforced with varying weight percentage of nano TiB2 (0-12.5 wt. %) and nano Gr (4wt %) via electromagnetic stir casting process to produce hybrid nanocomposites samples. Identification of phases and microstructure analysis are performed through X-ray diffraction, Optical Microscope and Scanning Electron Microscope with Energy Dispersion X-ray Spectrum. Mechanical properties such as hardness, tensile, compression and flexural strength were investigated on the prepared hybrid nanocomposites samples. Microstructure images of the samples reveals uniform dissemination of reinforced TiB2 and Gr nanoparticles in Aluminium base matrix and X-ray diffraction confirms the presence of reinforced particles TiB2 and Gr in Aluminium base matrix. Concluded from the consolidated samples, mechanical properties of the reinforced samples improved as compared to the matrix material.
Study of self-healing capability of composite material with phase changing paraffin wax and graphene
Authors: Kumar Gondela Yaswanth , Jhanji Kanu Priya , Amit Kumar R
Published: August 2022

The main aim of this research work was to conduct an experimental study of self-healing capability of the composite material by using phase changing material. The phase changing material utilized was “paraffin wax” for healing the material made up of the carbon fiber and epoxy. Three combinations of carbon fiber reinforced epoxy with phase changing materials were prepared i.e., plain carbon fiber epoxy without any phase changing material, carbon fiber epoxy with paraffin wax and carbon fiber epoxy with paraffin wax nano graphene. The fabrication of the carbon fiber composite material inside the capsulation has been done by keeping the 3d model. To identify the structural properties of the material some tests were done i.e., the tensile test and flexural test at normal room temperature and pressure. Damage was produced at the center of each specimen with the help of a Barcol hardness test machine. The Specimens were tested without indentation damage, immediately after indentation damage and after 48 hours of producing damage.
Influence of Photo-initiator concentration on photoactivation of composites prepared with LTCC and silver powders for DLP based 3D printing and their characterization
Authors: Joseph Jesly , Kondhalkar Jyoti , Jagdale Pankaj , Gadde Janardhan Rao , Hawaldar Ranjit , Kashid Ranjit , Giramkar Vijaya , Joseph Shany
Published: August 2022

DLP (Digital Light Processing) based 3D (three dimensional) printing had been a widely used additive manufacturing technique with its broad aspects in rapid prototyping, packaging, biomedical applications, PCB etc due to its high resolution and reliability. Since, drive for miniaturization in electronic industry had been increasing; the need of additive manufacturing becomes better and reliable solution for fabrication of electronic device. In this study, we attempt to adopt LTCC (Low Temperature co-fired ceramic) technology with DLP based additive manufacturing machine to reduce lead time, running cost and investment cost while increasing production volume to levels suited for SMEs. This work reports our 3D Printing trials with composites using LTCC/dielectric and silver powder. Initial trials using the commercially available resins showed residue after firing the package which indicates its unsuitability for electronic packaging applications. Hence, the new resin was formulated by varying the Photo-initiator 2,4,6 -trimethyl benzoyl diphenyl phosphine oxide (TPO) Concentration. Photoresist was prepared by mixing the Photo-initiator (1 to 3wt %), Surfactant (2.5wt %) and diacrylate based monomer (96.5 -94.5wt%) in planetary mixer and the composition was optimised. Curing parameters for the unloaded resin such as exposure time, Intensity etc were varied accordingly and optimised. The photoresist and the printed samples were analysed for their viscosity, optical inspection, NMR, FTIR. Printing trials were done by preparing composites with Dielectric (LTCC) and conducting material (Silver) using above prepared photopolymer in 50:50 ratio. Effect of variation in the exposure time and intensity on the loading of functional material for curing has also been studied. Printed patterns were then sintered at about 875°C with standard LTCC firing cycle. No residue was observed after the sintering cycle. Trials using composites with different material were also tried. Characterisation of these composites and printed packages are reported. For 50% loading of functional material shrinkage of about 29% was observed. Effect of solid loading on shrinkage of sintered sample were also studied and reported.
Effect of aging on reclaimed asphalt pavement and rejuvenators
Authors: Aeron P , Aggarwal P
Published: August 2022

Reclaimed Asphalt Pavement (RAP) material primarily consists of extracted asphalt concretes from the existing road infrastructure. It comprises 2 major non-renewable resources, i.e., aggregates and bituminous binder and their conscious use can ensure the sustainability of bituminous pavement construction. In this study, more focus is given to the asphalt binder, which is extracted from RAP. It has been tried to replace more and more new virgin binders with recycled RAP binders. But to counteract the higher stiffness of the RAP binder, it is rejuvenated to achieve strength higher or equivalent to the target binder. To have confidence in the efficacy of the RAP binder and rejuvenator in unaged and aged conditions, different combinations of blends are made and tested in aged as well as unaged conditions. In this study, Two RAP sources with and without virgin binder are rejuvenated with two rejuvenators. Physio-rheological tastings are done on each same. Based on achieved results aging index of all the blends is found. These results authenticate the aging properties of RAP binder as well as rejuvenators.
Evaluation of mechanical and tribological properties of Aluminium metal matrix composite reinforced with titanium diboride and graphite
Authors: Anitha P , Srinivas Rao M
Published: August 2022

The purpose of this research is to assess mechanical and tribological behavior of Aluminum matrix nanocomposites reinforced with varying weight percentage of 0%, 2.5%, 5%, 7.5%, 10% and 12.5% titanium diboride (TiB2) nano particles and 6% graphite (Gr) nanoparticles through electromagnetic stir casting process. Microstructure analysis were examined using Optical microstructure, Scanning Electron Microstructure, Energy Dispersive Spectrum and phases of reinforced particles in the Aluminium alloy were identified using X-ray diffraction. Mechanical and tribological testing were conducted. Regarding mechanical properties such as tensile strength, flexural strength, compression strength, and wear resistance of all reinforced composite specimens presented enhanced properties than the unreinforced matrix. It was found that the enhanced mechanical properties and wear behavior of the tested specimens of aluminium hybrid nanocomposites has been achieved due to presence of strengthening of hard ceramic nanoparticles of TiB2 in the matrix.
Influence of the Manufacturing Variances on the Strength of the Pressure Vessel
Authors: Cheranseshagirirao Innamuri V. G. , Harshavardhan Kodali , Jayaram Behara Dheenabandu , Sri Valli G. , Sri Chaitanya Ch. , Narasimha Rao R.
Published: August 2022

The pressure vessels are used to contain fluids that are at a pressure that is significantly different from the atmosphere. İn the present study, multiple carbon fibre reinforced composite pressure vessels were modelled in ANSYS with the variation of the fibre orientation angle. Internal pressure was applied to the pressure vessels, then it was considered to be failed if the first ply burst failure was occurred. The Tsai-Hill failure criterion was applied to the model. The fibre orientation angle of 55°/-55° was found to have good strength. The deformation modes changed from the lateral deformation at lower fibre orientation angles to the axial deformation at higher angles. For axial loading the lower fibre orientation angle has better strength. The fibre orientation angle of 30° showed better properties for the axial loads. For the combination of the axial and the internal pressure as the load, the 55° orientation angle showed better resistance.
Numerical analysis of sandwich panels under high-velocity impact
Authors: Srilakshmi R , Sanjay kumar R
Published: August 2022

Composites are gaining importance in aircraft structures, due to their high specific strength, stiffness, and low weight. There are different types of composites used in aircraft structures out of which carbon fiber reinforced polymer (CFRP) serves best in the aircraft industry. Half of the weight of the Boeing 787 is made of CFRP and other composites that reduced the weight of the aircraft by 20% as compared to the conventional design with aluminum alloy. Similar to CFRP the recent trend focused on the usage of sandwich structures in aircraft design. Sandwich structure is a composite material made of the lightweight thick core placed between the thin face sheets made of CFRP or Glass fiber reinforced polymer. During service, aircraft panels are subjected to severe structural, aerodynamics loads, and impact loads. These loads cause severe damage to the structure that affects the residual strength. The impact is the more susceptible damage in composite panels. In this paper, a numerical impact analysis of the sandwich panel is carried out. There are different parameters that influence the impact strength of sandwich panels are face sheet material, core material, and thickness of the core. In this paper, finite element-based parametric analysis is carried out by varying face sheet materials such as CFRP, GFRP, Al alloy, Ti alloy, and core materials (such as honeycomb structure and PVC foam). Further, in this work, the combined MADM method using TOPSIS and AHP is applied to find out the optimal face sheet material for the sandwich panel. The attribute data for applying the MADM method is obtained from finite element analysis (FEA).
Effect of Ca content on biomineralization of Mg-Ca alloys
Authors: Favas T , Rahim Shebeer A. , Muhammad Rabeeh VP , Joseph M A , Hanas T
Published: August 2022

The mechanical and physical properties of biodegradable Mg-based alloys make them suitable for temporary orthopaedic implants. However, processing them in such a way that it degrades at the required rate in physiological environment is a challenge. Among the possible methods, in situ formation of calcium phosphate (CaP) during service to control the degradation rate is least explored. The CaP formation can be improved by enhancing the biomineralization of Mg alloys. The present work investigates the effect of Ca concentration (0, 0.5, 1, and 2 wt.%) on the biomineralization of Mg-Ca alloys. Optical microscopy observations and X-ray diffraction analysis showed that Mg-xCa (x = 0.5, 1 & 2 wt. %) alloys were composed of two phases, α-Mg and Mg2Ca. The electrochemical corrosion test in biomimetic NaCl solution and immersion test in simulated body fluid shows that the corrosion rate increases as Ca content increases. The studies reveal that a low calcium content single-phase microstructure is preferred over a multiphase morphology for promoting biomineralization.
A review, tabulation of the Antimicrobial Effect of Silver Nanoparticles
Authors: Shehla
Published: August 2022

Silver nanoparticles are used in every single aspect of science including medical and pharmaceuticals, as they have high antimicrobial effects because of their large surface area to volume ratio, which is the curiosity of new researchers on antibiotics, the growing microbial resistance and the development of resistant strains. Silver nanoparticles are the superabundant antimicrobial agent for bacteria, fungi, algae and are less noxious to human cells than bacterial cells. Silver nanoparticles are used to control germination in a variety of applications, such as antibacterial coating for medicinal materials to promote wound healing and prevent infection, and antibacterial vaccines to control bacterial diseases. In the current work, a review of the antimicrobial properties of silver nanoparticles is compiled in tabular form reported by different research groups. The aim of this review is to discuss the present state of affairs and suggestions for future possibilities in this field.
Chitinase 3-Like 2
Authors: Nimbalkar Vidya P , Kruthika Banavathy S , Sravya Palavalasa , Rao Shilpa , Sugur Harsha S , Chickabasaviah Yasha T , Somanna Sampath , Arivazhagan Arimappamagan , Kondaiah Paturu , Santosh Vani
Published: August 2022

Objectives

We aimed to evaluate the expression pattern of chitinase 3-like 2 (CHI3L2) in the tumor core and peritumoral brain zone (PBZ) of newly diagnosed glioblastoma (GBM) in recurrent tumors and its association with patient prognosis.

Methods

The study was conducted on three sample sets derived from different patient cohorts. Messenger RNA (mRNA) expression of CHI3L2 in the tumor core and PBZ (n = 34) compared with control (n = 20) tissues was studied by quantitative polymerase chain reaction in sample set 1. Sample set 2 included 19 paired, primary-recurrent GBM tissues. Sample set 3 comprised 82 GBM tissues of patients with treatment and follow-up information. Immunohistochemistry (IHC) was performed on all three sample sets.

Results

mRNA expression of CHI3L2 was significantly higher in the tumor core and PBZ compared with control (P < .0001). By IHC, CHI3L2 showed strong cytoplasmic staining in tumor cells. Recurrent tumors had a higher expression of CHI3L2 compared with primary tumors (P = .007). Survival analysis showed CHI3L2 expression was associated with shorter overall survival (P = .034) and progression-free survival (P = .010), which was in line with The Cancer Genome Atlas cohort (P = .043).

Conclusions

High expression of CHI3L2 in the tumor core and PBZ, as well as its association with tumor recurrence and poor patient prognosis, suggests it might be contributing to tumor spread and recurrence.
Integrative genomics important to understand host–pathogen interactions
Authors: Mehta Priyanka , Swaminathan Aparna , Yadav Aanchal , Chattopadhyay Partha , Shamim Uzma , Pandey Rajesh
Published: August 2022

Infectious diseases are the leading cause of morbidity and mortality worldwide. Causative pathogenic microbes readily mutate their genome and lead to outbreaks, challenging the healthcare and the medical support. Understanding how certain symptoms manifest clinically is integral for therapeutic decisions and vaccination efficacy/protection. Notably, the interaction between infecting pathogens, host response and co-presence of microbes influence the trajectories of disease progression and clinical outcome. The spectrum of observed symptomatic patients (mild, moderate and severe) and the asymptomatic infections highlight the challenges and the potential for understanding the factors driving protection/susceptibility. With the increasing repertoire of high-throughput tools, such as cutting-edge multi-omics profiling and next-generation sequencing, genetic drivers of factors linked to heterogeneous disease presentations can be investigated in tandem. However, such strategies are not without limits in terms of effectively integrating host–pathogen interactions. Nonetheless, an integrative genomics method (for example, RNA sequencing data) for exploring multiple layers of complexity in host–pathogen interactions could be another way to incorporate findings from high-throughput data. We further propose that a Holo-transcriptome-based technique to capture transcriptionally active microbial units can be used to elucidate functional microbiomes. Thus, we provide holistic perspective on investigative methodologies that can harness the same genomic data to investigate multiple seemingly independent but deeply interconnected functional domains of host–pathogen interaction that modulate disease severity and clinical outcomes.
Cranial differences in three-toed jerboas (Dipodinae, Dipodidae, Rodentia) according to recent taxonomic revisions
Authors: Alhajeri Bader H , Hasan Zahraa , Alhaddad Hasan
Published: August 2022

Recent phylogenetic studies amended the taxonomy of three-toed jerboas (subfamily Dipodinae), including raising subspecies to full species. Here, we use geometric morphometrics to compare scaled-shape differences in dipodine crania while considering their revised taxonomy. We sampled Dipus deasyi, D. sagitta halli, D. s. sowerbyi, Jaculus blanfordi blanfordi, J. hirtipes, J. jaculus, J. loftusi, J. orientalis gerboa, J. o. mauritanicus, and Stylodipus andrewsi. Crania were not sexually dimorphic. Common allometry explained some of the shape variation, for example, reduced braincases in larger specimens. Most operational taxonomic unit pairs differed in both size and shape. Dipus and Stylodipus clustered together based on their cranial shape. Jaculus differed from the aforementioned genera by its larger tympanic bulla, broader braincase, larger infraorbital foramen, along with reduced molars and rostra. Jaculus orientalis differed from other Jaculus by its broader face versus reduced cranial vault. Jaculus blanfordi (subgenus Haltomys) resembles members of the subgenus Jaculus more than its consubgener (J. orientalis). Jaculus loftusi, previously considered a synonym of J. jaculus, clearly differed from the latter by its shorter rostrum, smaller infraorbital foramen, and more caudolaterally expanded tympanic bulla. Jaculus hirtipes, another recent synonym of J. jaculus, resembled J. blanfordi more in scaled cranial shape than it did J. jaculus. Dipus sagitta halli and D. s. sowerbyi were indistinguishable, but they clearly differed from D. deasyi (recently raised to full species) with the latter having a larger molar row, more inflated tympanic bulla, and shorter, slenderer rostrum. Ecological explanations for detected cranial shape differences are considered, including diet and habitat (particularly substrate).
Acute valvular emergencies
Authors: Bernard Samuel , Deferm Sebastien , Bertrand Philippe B
Published: August 2022

Acute valvular emergencies represent an important cause of cardiogenic shock. However, their clinical presentation and initial diagnostic testing are often non-specific, resulting in delayed diagnosis. Moreover, metabolic disarray or haemodynamic instability may result in too great a risk for emergent surgery. This review will focus on the aetiology, clinical presentation, diagnostic findings, and treatment options for patients presenting with native acute left-sided valvular emergencies. In addition to surgery, options for medical therapy, mechanical circulatory support, and novel percutaneous interventions are discussed.