Modeling and Analysis of ArtificialArm

A precise modeling and an analysis on an artificial arm have a very significant role in the control action applications. The control activities are useful to identify the system performance and design requirements. The efforts have been made by the researchers to initiate different approaches to direct the best effective model. The state-space analysis has been introduced to analyze different control performances such as controllability, observability and stability testing of the standard artificial arm model after producing the closed loop representation by the simulation approach using Jury stability and Lyapunov stability analysis. The control action analysis shows the relevancy and the precision of the proposed mathematical model

Design Of Dual Band Microstrip Antenna For Telephony System

Antennas are essential part of communication systems. Without antenna wireless connection become difficult. For effective communication, certain parameters need to be concerned. Depending upon the signal frequency the length of an antenna becomes very large. Microstrip antenna deals with this problem, where equivalent antenna can be designed in small size. This helps in integration of electronic and communication devices. This work presents broadband microstrip antennas for Telephony systems applications. Using co-linear patch design, microstrip antennas are made. These antennas are capable to work with GSM technology. This research also shows how an antenna can be designed within the same size, where antennas are operating in single band as well as multiban

Rheology Based Design of Shear Thickening Fluid for Soft Body Armor Applications

The ballistic resistance of high-strength fabrics improves upon impregnation with Shear Thickening Fluids (STFs). The performance of such STF treated fabrics depends on the rheological properties of the STF which in turn are governed by the physicochemical properties of the STF. The present study utilizes rheological characterization of shear thickening silica-polyethylene glycol dispersions (of different material configurations in terms of packing fraction, particle size and continuous phase viscosity) to assess their performance and obtain the best STF material configuration for ballistic body armor applications based on the design criteria proposed herein. The ballistic performance assessment results showed that the STFs with high packing fractions which thicken discontinuously, are highly effective compared to the continuously shear thickening fluids. Furthermore, the use of smaller particle size dispersed phase in the STF formulation was determined to be economical. Also, the use of lower molecular weight dispersion medium was suggested as it allows for a broader working temperature range of the STF. Additionally, the technological issues associated with the development and the practical application of STF-Armor were addressed

Early and extended erythropoietin monotherapy after hypoxic ischaemic encephalopathy:a multicentre double-blind pilot randomised controlled trial

Objective: To examine the feasibility of early and extended erythropoietin monotherapy after hypoxic ischaemic encephalopathy (HIE). Design: Double-blind pilot randomised controlled trial.Setting: Eight neonatal units in South Asia. Patients: Neonates (≥36 weeks) with moderate or severe HIE admitted between 31 December 2022 and 3 May 2023. Interventions: Erythropoietin (500 U/kg daily) or to the placebo (sham injections using a screen) within 6 hours of birth and continued for 9 days. MRI at 2 weeks of age. Main outcomes and measures: Feasibility of randomisation, drug administration and assessment of brain injury using MRI. Results: Of the 154 neonates screened, 56 were eligible; 6 declined consent and 50 were recruited; 43 (86%) were inborn. Mean (SD) age at first dose was 4.4 (1.2) hours in erythropoietin and 4.1 (1.0) hours in placebo. Overall mortality at hospital discharge occurred in 5 (19%) vs 11 (46%) (p=0.06), and 3 (13%) vs 9 (40.9%) (p=0.04) among those with moderate encephalopathy in the erythropoietin and placebo groups. Moderate or severe injury to basal ganglia, white matter and cortex occurred in 5 (25%) vs 5 (38.5%); 14 (70%) vs 11 (85%); and 6 (30%) vs 2 (15.4%) in the erythropoietin and placebo group, respectively. Sinus venous thrombosis was seen in two (10%) neonates in the erythropoietin group and none in the control group. Conclusions: Brain injury and mortality after moderate or severe HIE are high in South Asia. Evaluation of erythropoietin monotherapy using MRI to examine treatment effects is feasible in these settings. Trial registration number: NCT05395195

Designing Thinner Broadband Multilayer Radar Absorbing Material Through Novel Formulation of Cost Function

Modern military and civic applications require broadband microwave multilayer radar absorbing material (MRAM), which typically consists of multiple layers that increase the thickness of platforms like aircraft, ships, and vehicles, thereby adding to their weight. To address this, MRAM design methods strive to optimize layer parameters to reduce thickness. In this article, we emphasize the importance of the cost function used in the optimization process, which can significantly affect the outcomes. This article investigates the impact of common cost function formulations on achieving global optima and proposes a new cost function that produces thinner MRAM designs without increasing algorithmic complexity. The new formulation works as a two-step optimizer and yields thinner results. The article compares the results for twelve different MRAMs with those of previous literature, and achieves maximum and minimum thickness reductions of 22.9562% and 0.009%, respectively. The findings highlight that the cost function formulation significantly impacts the design outcome and can be used to obtain thinner designs. Additionally, the proposed approach is more effective than other commonly used formulations for finding the optimal layer sequence and minimizing thickness using a given search algorithm

Measurement of effective permeability of reinforcement mats using sensitivity analysis

A methodology using sensitivity analysis is proposed to measure the effective permeability which includes the interaction of the resin and the reinforcement. Initially, mold-filling experiments were performed at isothermal conditions on the test specimen and the positions of the flow front were tracked with time using a flow visualization method. Following this, mold-filling experiments were simulated using a commercial software to obtain the positions of the flow front with time at the process conditions used for experiments. Several iterations were performed using different trial values of the permeability until the experimentally tracked and simulated positions of the flow front with time were matched. Finally, the value of the permeability thus obtained was validated by comparing the positions obtained by performing the experiments at different process conditions with the positions obtained by simulating the experiments. In this study, woven roving and chopped strand mats of E-class glass fiber and unsaturated polyester resin were used for the experiments. From the results, it was found that the measured permeabilities were consistent with varying process conditions. POLYM. COMPOS., 2012. (c) 2012 Society of Plastics Engineer

Discrete Domain Analysis Of Dexterous Hand Model By Simulation Aspect

AbstractDexterity, adroitness in using the hands or body, is the prime or essential aspect in modeling dexterous hand. Deterministic response analysis of Dexterous Hand Model (DHM) advances the research area with the development of prosthetic control. Simulation procedure implies to build up stability of the reference transfer function of Dexterous Hand. Stability analysis with all simulation aspect is required to expand the discrete domain transfer function. The present work deals with the discussion of stability criteria and simulation in discrete domain by approaching Jury Test with sampled data control model