Magneto-Rheological Fluid Device as Artificial Feel Force System on Aircraft Control Stick

The conventional feel system in any aircraft occupies large space in the cockpit and has complicated designs. The primary objective of this research is to develop an artificial feel force system that can overcome some drawbacks of the current feel force system. A novel feel system using magneto-rheological (MR) fluid is constructed to precisely control the shear stress under the magnetic field. To validate the functionality of the MR artificial feel system, the final system is fabricated and multiple tests are performed to acquire force-velocity characteristics that are compared to the mathematical model derived. In addition, the reference model of the force feedback control is simulated for the feel force application. Both experimental and simulation results are compared to validate the derived system model. The system response time and the sampling rates are evaluated and compared to the conventional system at the end. It is concluded from the research that the developed artificial feel system can precisely control and acts as a fail proof system when incorporated with a modern fly-by-wire aircraft system

Improved Approximation Bounds for Minimum Weight Cycle in the CONGEST Model

Minimum Weight Cycle (MWC) is the problem of finding a simple cycle of minimum weight in a graph $G=(V,E)$. This is a fundamental graph problem with classical sequential algorithms that run in $\tilde{O}(n^3)$ and $\tilde{O}(mn)$ time where $n=|V|$ and $m=|E|$. In recent years this problem has received significant attention in the context of hardness through fine grained sequential complexity as well as in design of faster sequential approximation algorithms. For computing minimum weight cycle in the distributed CONGEST model, near-linear in $n$ lower and upper bounds on round complexity are known for directed graphs (weighted and unweighted), and for undirected weighted graphs; these lower bounds also apply to any $(2-\epsilon)$-approximation algorithm. This paper focuses on round complexity bounds for approximating MWC in the CONGEST model: For coarse approximations we show that for any constant $\alpha >1$, computing an $\alpha$-approximation of MWC requires $\Omega (\frac{\sqrt n}{\log n})$ rounds on weighted undirected graphs and on directed graphs, even if unweighted. We complement these lower bounds with sublinear $\tilde{O}(n^{2/3}+D)$-round algorithms for approximating MWC close to a factor of 2 in these classes of graphs. A key ingredient of our approximation algorithms is an efficient algorithm for computing $(1+\epsilon)$-approximate shortest paths from $k$ sources in directed and weighted graphs, which may be of independent interest for other CONGEST problems. We present an algorithm that runs in $\tilde{O}(\sqrt{nk} + D)$ rounds if $k \ge n^{1/3}$ and $\tilde{O}(\sqrt{nk} + k^{2/5}n^{2/5+o(1)}D^{2/5} + D)$ rounds if $k<n^{1/3}$, and this round complexity smoothly interpolates between the best known upper bounds for approximate (or exact) SSSP when $k=1$ and APSP when $k=n$

Spider Search Algorithms for MIMO System and Assessment Using Simatic PCS7

This paper shows two optimization methods that are built on a spider optimization algorithm to enhance the proportional integral and derivative (PID) gain values for multiple-input-multiple-output (MIMO) arrangement which is automated with SIMATIC PCS7 Distributed Control System (SDCS). The leading methodologies are the Spider Search Algorithm (SSA) and Social Spider Optimization (SSO) which is meant primarily for optimizing PID gain values. The SSA is based on foraging strategy of colonial spiders and SSO works on the combined plan of the male and female spiders that removes the episodes of local optimization and exploration elusion. Thus, SSA and SSO are contrived for the ideal fine-tuning of PID conditions in the benchmark MIMO procedure. The system performance is understood by minimizing the integral absolute error (IAE) and the integral square error (ISE) as its objective functions. The time-domain features are examined for the aforesaid methods and thereafter compared with the previous genetic algorithm (GA). The settling time is 60s for the proposed method which is lesser than the other techniques. For illustrating the implemented controller\u27s strength, interference is manually presented in the real-time system. Findings indicate that the SSO surpasses output measures and performance indices beyond the presupposed SSA and GA intervals

Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

Machinability assessment of Ti-6Al-4V for aerospace applications

Titanium alloy Ti-6Al-4V is the most commonly used titanium alloy in the aerospace and biomedical industries due to its superior material properties. An experimental investigation has been carried out to evaluate the machinability of high performance aerospace alloys (Ti-6Al-4V) to determine their in service performance characteristics based on different machining strategies. Nearly 80-90% of the titanium used in airframes is Ti-6Al-4V. The experimental design consist of face milling Ti-6Al-4V at 12 different combinations of cutting parameters consisting of Depth Of Cut (DoC)- 1, 2 and 3 mm; speeds- 60 and 100 m/min; coolant on/off and at constant feed rate of 0.04mm/tooth. Post machining analysis consists of cutting force measurement, surface texture analysis and metallographic analysis. The future work consists of in-depth investigation into the phase transformational reactions during machining

Design and Development of Autonomous Amphibious Unmanned Aerial Vehicle for in-situ Water Quality Assessment and Water Sampling

This paper presents the design and development of an Autonomous Amphibious Unmanned Aerial Vehicle (AAUAV) System with hybrid version of a Multicopter and a Hovercraft that can vertically take-off and land as well as travel on water and smooth earth surfaces for water based applications like water quality assessment, water sampling, remote sensing, underwater mapping etc. Based on the conceptual design, parameters such as aircraft overall dimensions, weight estimation, aircraft performance, power requirement and endurance of the UAV were calculated and evaluated. Using these computed parameters, a suitable propulsion system was selected. A 3D CAD model of the UAV was developed and 2D manufacturing drawings were made. Finally, a prototype of the UAV was fabricated, assembled, and all the sub-systems were integrated. Initial trial runs were made to check the proper functioning of all sub-systems as intended. Subsequently, to verify and validate the UAV’s concept and design configuration, ground and field tests were conducted to test the vertical-take-off and landing, flying, and amphibious capabilities of the developed unmanned system. Results of the tests have proven that a well-conceived Design and development has been successfully completed.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Utility of restage transurethral resection of bladder tumor

Introduction: Transurethral resection of bladder tumor (TURBT) aims at complete resection of all the visible tumors. Existing guidelines recommend restage TURBT in all patients with T1 and high-grade tumors, to avoid under-staging. However, restage TURBT may not be plausible/feasible at all the times. This study was performed with an aim to better define the utility of restage TURBT in a tertiary care hospital of India. Methods: Patients with high grade/T1 tumors at the first TURBT were prospectively enrolled. Their demographic profile, previous cystoscopic findings, and histological reports were recorded. The primary objective was to assess the tumor detection and stage up-migration rates at restage TURBT. The secondary objectives was to identify factors predicting presence of tumor at restage TURBT. Patients were followed up to detect recurrence and progression for a minimum of 3 months. Results: Of 128 prospective patients' enrolled, 29 patients were lost to follow-up and 11 patients did not undergo restage. A total of eighty-eight patients underwent restage TURBT of which twenty-eight patients (31.8%) had tumor at their second TURBT with five of these patients being upstaged to T2. The risk of having a tumor at restage was significantly higher in patients with solid tumors (56.2% vs. 26.4%, P = 0.02, 95% confidence interval: 0.035–0.024) but was independent of the tumor size (P = 0.472), number of growths (P = 0.267), grade of tumor (P = 0.441), presence or absence of muscle at the initial TURBT (P = 0.371) and place of initial TURBT (P = 0.289). There was a significant difference in the recurrence and progression rates in patients who had tumor at restage as compared to those who did not (recurrence; 33.3% and 23.8%, P = 0.022, respectively vs. progression; 11.1% and 3.7% respectively, P = 0.07; mean follow-up = 10.8 months). Conclusions: We conclude that restage TURBT is necessary in patients with solid looking tumors and the presence of tumor at restage confers a higher risk of recurrence and progression

Gene Expression Profiling Reveals Enhanced Defense Responses in an Invasive Weed Compared to Its Native Congener During Pathogenesis

Invasive plants are a huge burden on the environment, and modify local ecosystems by affecting the indigenous biodiversity. Invasive plants are generally less affected by pathogens, although the underlying molecular mechanisms responsible for their enhanced resistance are unknown. We investigated expression profiles of three defense hormones (salicylic acid, jasmonic acid, and ethylene) and their associated genes in the invasive weed, Alternanthera philoxeroides, and its native congener, A. sessilis, after inoculation with Rhizoctonia solani. Pathogenicity tests showed significantly slower disease progression in A. philoxeroides compared to A. sessilis. Expression analyses revealed jasmonic acid (JA) and ethylene (ET) expressions were differentially regulated between A. philoxeroides and A. sessilis, with the former having prominent antagonistic cross-talk between salicylic acid (SA) and JA, and the latter showing weak or no cross-talk during disease development. We also found that JA levels decreased and SA levels increased during disease development in A. philoxeroides. Variations in hormonal gene expression between the invasive and native species (including interspecific differences in the strength of antagonistic cross-talk) were identified during R. solani pathogenesis. Thus, plant hormones and their cross-talk signaling may improve the resistance of invasive A. philoxeroides to pathogens, which has implications for other invasive species during the invasion process

A rapid and low-cost microscopic observation drug susceptibility assay for detecting TB and MDR-TB among individuals infected by HIV in South India.

BACKGROUND: The converging epidemics of HIV and tuberculosis (TB) pose one of the greatest public health challenges of our time. Rapid diagnosis of TB is essential in view of its infectious nature, high burden of cases, and emergence of drug resistance. OBJECTIVE: The purpose of this present study was to evaluate the feasibility of implementing the microscopic observation drug susceptibility (MODS) assay, a novel assay for the diagnosis of TB and multi-drug-resistant tuberculosis (MDR-TB) directly from sputum specimens, in the Indian setting. MATERIALS AND METHODS: This study involved a cross-sectional, blinded assessment of the MODS assay on 1036 suspected cases of pulmonary TB in HIV-positive and HIV-negative patients against the radiometric method, BD-BACTEC TB 460 system. RESULTS: Overall, the sensitivity, specificity, positive predictive value, and negative predictive value of the MODS assay in detecting MTB among TB suspected patients were 89.1%, 99.1%, 94.2%, 95.8%, respectively. In addition, in the diagnosis of drug-resistant TB, the MODS assay was 84.2% sensitive for those specimens reporting MDR, 87% sensitivity for those specimens reporting INH mono-resistance, and 100% sensitive for specimens reporting RIF mono-resistance. The median time to detection of TB in the MODS assay versus BACTEC was 9 versus 21 days (P<0.001). CONCLUSION: Costing 5 to 10 times lesser than the automated culture methods, the MODS assay has the potential clinical utility as a simple and rapid method. It could be effectively used as an alternative method for diagnosing TB and detection of MDR-TB in a timely and affordable way in resource-limited settings