பொருள் அறிவியல் & பொறியியல் இதழ்

3D-DGI (Discrete Geometrical Invariants) method allows to reduce initial rectangle matrices N×M (N-is number of data points, M < N is number of columns) to a matrix M× P (P=13), where P – represents a set of invariants combined from of the first, second, third and the fourth moments inclusive. This “universal” platform allows to compare any random trendless sequences (TLS) with each other. The further analysis shows that one can extract only two significant parameters/criteria (free from treatment and model errors) for comparison of TLS recorded from the given set of ADCs. The experimental data set represented 15 rectangle matrices with parameters N=20000, M=150 (filtered in the region 1.1-5.0 kHz) and 15 matrices that were not subjected to the filtration procedure. The proposed algorithm given in the paper allows to select the “best” ADC&Amplifier combination from the given ones based on analysis of their TLS(s) and proposed criteria. The authors think that the algorithm can find a wide application in the industrial electronics based on the simplicity, reproducibility and reliability of the proposed procedure.

Sound absorption behavior is an important requirement for the human life today, since noise affects the capability of day to day activities and even causes various health problems. Sound absorbent textile materials, especially non-woven composite structure of reclaimed materials have low production costs, low specific gravity and are aesthetically appealing. In this research the use of reclaimed cotton and polyester fiber for the development of sound absorptive non-woven composite materials has been explored. Three different blend ratios of reclaimed cotton and polyester fibers that is 25:75, 40:60 and50:50 have been used. The reclaimed cotton and polyester non-woven composites are characterized for their physical properties, such as thickness, areal density, bulk density, porosity and sound absorption characteristics in the frequency range of 250HZ-2000HZ. The values of sound absorption coefficient and noise reduction coefficient obtained signify that the reclaimed polyester fiber non-woven composite possess very good sound absorption behavior in the entire frequency range. Before compressed reclaimed cotton/polyester nonwoven composite of 25:75 blend ratio with high bulk density and low porosity is found to give the excellent performance when used by provided that air gap behind the reclaimed cotton/polyester non-woven composites.

Lithium Ion Batteries (LIBs) have paved the way for the creation of portable consumer electronics and electric vehicles. The demands for LIBs of various chemistries show no sign of slowing. Many valuable metals, like Lithium and Cobalt, are contained in batteries, located primarily on the cathode component. The burden from increasing demand of LIBs has attracted attention to reuse the valuable active materials from the cathodes. This paper reviews the recent development of reusing spent LIBs in three categories: Pretreatment, Recycling and Regeneration. Pretreatment covers discharging, dismantling of the spent LIBs and separation of the useful part from waste; Recycling focuses on the recovery of value materials, four strategies (pyrometallurgy, hydrometallurgy, biometallurgy and electrochemical process) are discussed in details; Regeneration revives the spent electrodes, the mostly used methods are organized, including solid state synthesis, hydrothermal treatment, sol-gel and co-precipitation method. We summarize the advantages and disadvantages of each method, aim to organize the state-of-the-art technologies and provide a guideline for future development.

Aluminium metrics based aluminium alloys have numerous applications in the field of modern technology. The aluminium alloys having three
platforms of industrial applications which are widely used in electronics goods, ground transportation such as automobile, aerospace
engineering and marine as well as military purposes. Aluminium alloys having low density, lightweight, excellent malleability and high
strength are the key potency of these alloys. At present, the aluminium alloys are the capability to full fill the current demand of the modern
industry. To enhance the mechanical properties of this aluminium alloys can be developed by reinforcing with ceramics such as SiC,
MgO, Gr and so on are used to achieve the desirable properties of the
materials. The present works investigated on Al 6061/B4C composites have been synthesized with different weight percentages of B4C (0, 1, 5,
and 15%) along with varied particulate sizes of 50, 100 and 150 μm were used. The cast composites were produced
via stir casting method and the addition of B4C particles in the base matrix has been analysis by SEM. The mechanical property such as
Vickers hardness and UTS has been studied and the values of ultimate tensile strength have been optimized using the Taguchi method

Coating of zinc was applied on stainless steel wire substrate using twin wire arc spray to change the surface properties of the substrate, such adhesion, wettability, and corrosion and wear resistance. In this work, there are three basic experimental activities. Firstly the coating parameter optimization, followed by wire coating and finally the fiber coats properties characterization. The properties of the coated wires have analyzed through metallographic analysis and bending test is a mechanical test was used in this work to study qualitatively the adhesion of the coated layer. The results showed that the optimal parameters to coat Zn-layer on the stainless steel wires are as following:

Voltage: 22 V
Current: 200 A
Air pressure: 2.4 bar
Stand-off distance: 150 mm
Wire clamping pressure: 1 bar
Gun speed: 18000 mm/min
Nozzle diameter: 2.2 mm
Blasting (pressure/distance): 6 bar/100 mm
Linear wire speed: 785.398 mm/min

Average coating thickness was varied between 100 µm and 220 µm.

The Zn-coating layer started to crack for the bending angles less than 120^°C.

This study aimed to investigate the impacts of triple-A supply chain (SC) on SC performance in Bahir Dar & Kombolcha textile Share Company, Ethiopia. The study used survey questionnaires as a data collection instrument. Statistical package for social science to purify measurement items through exploratory factor analysis & Partial least square structural equation model used to test whether SC agility, SC adaptability and SC alignment have individual and/or joint effects on SC performance. The finding indicates that SC adaptability, SC alignment and SC agility have a positive and significant effect on SC performance. The result also indicates that the joint triple-A SC had the strongest impact on SC performance.

Diabetic neuropathy is a debilitating complication of diabetes that is often diagnosed long after irreversible damage has occurred in a patient. Diagnosis of the condition commonly occurs when examinations reveal physical changes in foot structure and ulcers of the foot; such damage reveals the condition but offers no chance at prevention. To better predict diabetic neuropathy and prevent damage, pressure sensors can be used to detect the onset of the condition before damage occurs. While several pressure sensing and foot mapping systems are commercially available, each is prohibitively expensive, requires specialized software, or maps a limited portion of the foot. We present an affordable, scalable, and high resolution pressure sensing system that maps the entire foot with a novel force sensor and sensor grid. The grid is based on a matrixed array of 704 individual sensors actuated by XactFSR resistive film. Each sensor consists of interlaced sensing fingers and measures 0.250 inch (6.35 mm) square. The device offers a solution that is several thousand dollars cheaper than other products, consists of commercially available boards and cables, and provides full mapping of the foot while operating with standardized and open source software packages. Our system provides emergent economies and regions presenting a high risk of diabetes with a predictive tool that can operate in nearly any environment.