Table of Contents - Volume 17 Number 2

This paper provides some considerations about the strategic role of engineering research to predict structural strength and avoid damage. Even in the case of defects or after a break, scientific research allows to understand the causes through Failure Analyses. This paper, after an in-depth examination and discussion of the causes of structural damage, reports an example of Failure Analysis of a component of a helicopter gearbox.

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Often newer practical materials and devices, with huge economic gains, have resulted from commercialization of suitable selections of latest research on materials and their applications. Spread of laboratory discoveries of semiconductors and their properties to practical applications in every sphere of life and industry is the easiest example. Present work will focus on a few random examples of newer materials science research topics that is, or may possibly be, commercially exploited. Piezoelectric (PE) materials including High Temperature (HT) PE materials will be outlined for industry to explore novel applications ranging from ultrafine manipulation to heavy duty drilling and making PE sensors, actuators and ultrasonic devices. Higher electrical conductivity of a defect form of II=VI oxides (Cd-O in particular) is highlighted for possible practical exploitations. For 2nd generation Electromagnetic Interference (EMI) Shielding, polymeric composites with either newer absorbing agents or newer reflecting agents or their mixtures will be outlined. Novel Fe- or Ni- based HTSCs (high temperature superconductors) are less anisotropic and rather metallic in contrast to Cu-oxide HTSCs. So, these offer added advantage for making superconducting electrical cables. A balanced presentation of these potentially usable materials and their basic physics will be attempted.

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There has been a continual upsurge on research pertaining to bio-based/ microbial healing of cracks in concrete (a pre-requisite component when it comes to construction design). Albeit, the application of bacteria in this realm has been documented widely over the years, howbeit, delving into fungus based self-healing under the deleterious ambience of concrete with oxygen and nutrient limitation, moisture deficit and high alkalinity has captured recent research impetus. In this context, we have tried to mine the current contextual information to gauge whether research on fungal-based self-healing concrete could be worthwhile. Recent systematic screening encompassing the application of genetically engineered strains, attests the profound untapped potential of specific fungal species in assisting sustainable self-healing to ensure resilient infrastructure. Known for their adaptability under a plethora of environmental stress-conditions and architecturally endowed with large surface-active biomass, fungi can display both biomineralization and organomineralization, leading to rapid and profuse precipitation of CaCO₃ (a befitting concrete-filler) for prospective sealing of cracks, even of large width, plausibly without any negative trade-off with respect to concrete’s strength. This article is thus compiled to mirror the various prospects, practical hitches and future direction of research in using fungi for concrete crack healing. 

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Barium bismuth titanate materials are noted for ferroelectric behavior, competitor to lead based relaxor dielectrics and even for coating having wear resistance, toughness for improving surface engineering applications. In the present context, a modified solid state process aided by agate-mortar activation for milling is carried in compare to mechanochemical milling, melt-quench method to generate the complex ceramic structure. Molar ratio of BaO:Bi₂O₃:TiO₂ 1:2:4 ratio have been taken with fixed soaking temperature to develop the material. Activation milling period is varied for 20 hours, 25 hours and 30 hours while soaking period descends in the order 10 hours, 8 hours and 6 hours keeping fixed temperature of about 700°C. XRD confirms the presence of peaks for all cases. Crystallite size is estimated by Scherrers formula with proper planes of index corresponding to JCPDS data. FTIR confirmed the phases developed by XRD while indicating the proper M-O bond formation from analysis in the required spectral range. EDX spectra analysis given the presence of required elements present in the sample.

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The silver nanoparticle was successfully synthesized by using the help of Phyllanthus emblica plant extract as a reducing agent and aqueous silver nitrate as the precursor. Moreover, physical and chemical methods are widely used for the synthesis of nanoparticles, but these methods have expensive and not ecofriendly. This study highlights the green, rapid, facile, cost-effective, and ecofriendly synthesis and synthesized nanoparticles also investigate their antibacterial activity. Synthesized silver nanoparticles are analyzed by different techniques of modes like XRD, UV-Visible spectroscopy, TEM, FTIR, and photoluminescence (PL). The prepared AgNPs show characteristic absorption peak in UV-Visible spectroscopy due to SPR (surface plasmonic resonance) band between 400 to 450 nm wavelength, which was confirmed by TEM (transmission electron microscopy) image.  X-ray diffraction (XRD) results showed the crystalline nature of AgNPs as well as the size of nanoparticles calculated with the help of TEM (20-25 nm) and XRD (25 nm). ATR spectroscopy identified the functional groups that are involved in the reduction of silver ion to AgNPs and the PL spectrum indicates higher emission in the green region and low emission peak in the UV region. Antibacterial activity of AgNPs analyzed against with the help of E.Coli bacteria and the result shows that a higher concentration of AgNPs is increasing as well as a zone of inhibition increased. This method is environmentally friendly, of low cost, and less expensive method for the fabrication of AgNPs in abundance which can be further helpful for biosensor devices as well as for other applications such as pollutant degradation, pharmaceutical, and hydrogen production, etc therefore can promote the application of green technology for the production of AgNPs.

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Indanone and 2,3-dihydrobenzofuran scaffolds are considered as special structures in therapeutic science and explicitly associated with various biologically potent compounds. In the present disclosure, we report the synthesis of two new 2,3-dihydrobenzofuran tethered arylidene indanones via an environmentally adequate and viable protocol. The two compounds revealed in this have been characterized well by analytical methods; proton magnetic resonance (PMR), carbon magnetic resonance (CMR). The Density Functional Theory (DFT) study has been presented for the spectroscopic, structural and quantum correlation between  (E)-2-((2,3-dihydrobenzofuran-5-yl)methylene)-2,3-dihydro-1H-inden-1-one (DBDI) and (E)-7-((2,3-dihydrobenzofuran-5-yl)methylene)-1,2,6,7-tetrahydro-8H-indeno[5,4-b]furan-8-one (DBTI). Optimized geometry, frontier molecular orbital, global reactivity descriptors, and thermodynamic parameters have been computed for DBDI and DBTI. DFT/B3LYP method using basis set 6-311++G (d,p) has been employed for the computational study. Mulliken atomic charges are established by using 6-311G (d,p) basis set. Besides, molecular electrostatic potential for DBDI and DBTI is also explored to locate the electrophilic and nucleophilic centres.

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Density (ρ), viscosity (η) and ultrasonic velocity (U) of chlorpheniramine with 1-ethanol mixtures are measured in a range of temperatures 303K, 308K and 313K. By using the systematic measurements, various physico chemical quantities, adiabatic compressibility (β), free length (L_f), free volume (V_f), viscous relaxation time (τ) and Gibbs free energy (ΔG) are attained. The deviations of those quantities to their ideal values are derived and revealed with the intermolecular interactions. The standard deviations and the coefficients of Redlich Kister polynomials of excess quantities are also determined to validate the calculations. From these observations, the existence of intermolecular interaction is confirmed and the strength of interactions with the temperatures as 303K>308K>313 K.

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Analysis of the mechanical properties of Polymer Composite Materials (PCM) fiberglass-reinforced is important for fiberboat manufacturing. Mechanical properties can be determined by carrying out mechanical testing. The mechanical properties of this research using the Impact test have been completed. In this research each test was carried out on variations in the amount of fiberglass lamination CSM 300, CSM 450 and WR 600 and the variation in weight percentages of 99.5% -0.5%, 99% -1%, 98.5% -1 , 5%, 98% -2% and 97.5% -2.5% have been used. The result show that the more the amount of laminate the greater impact strength, which is equal to 413,712 MPa, and the more the percentage hardener the greater the impact strength 2.0 wt .-%, which is equal to 416,487 MPa.

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Hydrogen fuel cell technology is now being extensively researched around the world to find a reliable renewable energy source. Global warming, national calamities, fossil-fuel shortages have drawn global attention to environment friendly and renewable energy source. The hydrogen fuel cell technology most certainly fits those requisites. New researches facilitate improving performance, endurance, cost-efficiency, and overcoming limitations of the fuel cells. The various factors affecting the features and the efficiency of a fuel cell must be explored in the course of advancement in a specific manner. Temperature is one of the most critical performance-changing parameters of Proton Exchange Membrane Fuel Cells (PEMFC). In this review paper, we have discussed the impact of temperature on the efficiency and durability of the hydrogen fuel cell, more precisely, on a Proton Exchange Membrane Fuel Cell (PEMFC). We found that increase in temperature increases the performance and efficiency, power production, voltage, leakage current, but decreases mass crossover and durability. But we concluded with the findings that an optimum temperature is required for the best performance.

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