Experimental Investigations & Effects of Cutting Variables on MRR and Tool Wear for AISI S2 Tool Steel

AbstractMachining is the most important of the manufacturing processes which involves the process of removing material from a work piece in the form of chips. Machining is necessary where tight tolerances on dimensions and finishes are required. Generally a machining process involves a large number of variables that affect its performance. Some of them are cutting parameters, geometry of cutting tool, coolant conditions, properties of tool material, properties of work piece, machine capabilities, etc. Among them, cutting parameters have profound effect on all kinds of performances when the same tool material and the same work piece material are used for machining. Therefore cutting parameters of speed, feed and depth of cut are considered as the process control variables and two important performance measures of CNC turning, namely, Metal Removal Rate (MRR) and Tool wear (TW) are considered for investigation. This paper presents the experimental investigations on the effects of cutting variables like Spindle speed, Feed and Depth of cut on the Material removal rate and tool wear. The experiments were conducted on AISI S2 tool steel grade on a CNC turning machine using carbide insert. The experiments were conducted as per the design of experiments. Initial trial experiments were conducted to fix the ranges for the control parameters. After conducting the experiments the MRR and Tool wear were measured and recorded. The effects were studied after plotting the graphs between the Input process parameters versus the responses using Design expert software. The results obtained in this study can by further used for optimizing the process parameters there by the optimized results help the operator to enhance the quality as well as machining rate

Dissipative-particle dynamics simulations of flow over a stationary sphere in compliant channels

Dissipative-particle dynamics (DPD), a particle-based fluid-simulation approach, is employed to simulate isothermal pressure-driven flow across a sphere in compliant cylindrical channels. The sphere is represented by frozen DPD particles, while the surrounding fluid is modeled using simple fluid particles. The channel walls are made up of interconnected finite extensible nonlinear elastic bead-spring chains. The wall particles at the inlet and outlet ends of the channel are frozen so as to hinge the channel. The model is assessed for accuracy by computing the drag coefficient CD in shear flow past a uniform sphere in unbounded flow, and comparing the results with those from correlations in literature. The effect of the aspect ratio λ of the channel, i.e., the ratio of the sphere diameter d to the channel diameter D, on the drag force FD on the sphere is investigated, and it is found that FD decreases as λ decreases toward the values predicted by the correlations as λ approaches zero. The effect of the elasticity of the wall is also studied. It is observed that as the wall becomes more elastic, there is a decrease in FD on the sphere.Harinath Reddy and John Abraha

COMPARATIVE IN-VITRO ANTIBACTERIAL AND ANTIFUNGAL ATTRIBUTES OF DIFFERENT SOLVENT EXTRACTS FROM LEAF, BARK, ROOT AND INFLORESCENCE OF MEMECYLON UMBELLATUM BURM.

This paper describes the antibacterial and antifungal activities and Minimum Inhibitory Concentration (MIC) of different solvent (pet. ether, chloroform, ethyl acetate, acetone, methanol and water) extracts of leaves, bark, root and inflorescence of Memecylon umbellatum burm. The percent yields from leaves, bark, root and inflorescence was found to be 0.2062 to 2.836, 0.0601 to 0.5142, 0.050 to 1.425, 0.0210 to 0.717 respectively. Overall, acetone extract produced from the leaves exhibited significantly (P < 0.05) higher antibacterial activity along with superior antifungal activity. MIC for acetone and ethyl acetate extract of leaf was found to be 0.5 mg for the entire organisms compared to 3-15 mg for other extracts. Such study will explore pharmacological activity of the tested parts of Memecylon umbellatum burm especially, the leaves which might be valuable for therapeutic applications

A UNIQUE MODULATOR FOR BOOST REGULATOR TO REDUCE THE VOLTAGE STRESS

The APS control can be used to lessen the current force on switches see how to avoid load as the traditional interleaving control can be used to help keep better performance in heavy load. This paper looks into a manuscript pulse width modulation (PWM) plan for 2-phase interleaved boost ripper tools with current multiplier for fuel cell power system by mixing alternating phase shift (APS) control and traditional interleaving PWM control. To be able to reduce output fuel cell stack output current ripple or even the electricity/electricity ripper tools input current ripple, whether passive filter or active filter may be used, however, this will raise the complexity from the system. The boundary condition for swapping between APS and traditional interleaving PWM control comes. In line with the aforementioned analysis, a complete power range control mixing APS and traditional interleaving control is suggested. Loss breakdown analysis can also be given look around the efficiency from the ripper tools. Finally, it's verified by experimental results. The whole process of a switching cycle from the ripper tools could be split into six stages at boundary condition that the current force on switch is going to be bigger than 1 / 2 of the output current with traditional interleaving control

Phytochemical screening and In Vitro Antioxidant potential of Memecylon umbellatum Burm leaf extracts

Objective: Different dry extracts of Memecylon umbellatum Burm leaf obtained by various solvents such as petroleum ether, chloroform, ethyl acetate, acetone, methanol and chloroform water (IP) was screened to reap the benefits of its antioxidant and free radical scavenging properties using ascorbic acid as standard antioxidants. Methods: The in vitro free radical scavenging activity was evaluated using diphenyl picryl hydrazyl (DPPH) radical method using various concentrations of dry extract in distilled water (1, 2, 4, 8, 16, 20 μg/ml) against blank with ascorbic acid as a standard in same concentrations. Results: Among the all extracts, Methanol leaf extract has showed higher Antioxidant activity (84.65 ± 0.064 %) having IC50 Value 11.81 ± 0.033 μg/ml at 20 μg/ml. While, IC50 value for ascorbic acid was found to be 8.91 ± 0.084 μg/ml. Conclusion: The results clearly indicate that Methanol leaf extract of Memecylon umbellatum is effective in free radical scavenging. So in future, this may emerge as promising natural herbal source of powerful antioxidant. Keywords: Memecylon umbellatum, DPPH reagent, Antioxidant activity, Ascorbic acid, IC50

Synthesis and Anti-Pancreatic Cancer Activity Studies of Novel 3-Amino-2-hydroxybenzofused 2-Phospha-γ-lactones

A series of 3-amino-2-hydroxybenzofused 2-phosphalactones (4a-l) has been synthesized from the Kabachnik-Fields reaction via a facile route from a one-pot three-component reaction of diphenylphosphite with various 2-hydroxybenzaldehyes and heterocyclic amines in a new way of expansion. The in vitro anti-cell proliferation studies by MTT assay have revealed them as potential Panc-1, Miapaca-2, and BxPC-3 pancreatic cell growth inhibitors, and the same is supported by molecular docking, QSAR, and ADMET studies. The MTT assay of their SAHA derivatives against the same cell lines evidenced them as potential HDAC inhibitors and identified 4a, 4b, and 4k substituted with 1,3-thiazol, 1,3,4-thiadiazol, and 5-sulfanyl-1,3,4-thiadiazol moieties on phenyl and diethylamino phenyl rings as potential ones. Additionally, the flow cytometric analyses of 4a, 4b, and 4k against BxPC-3 cells revealed compound 4k as a lead compound that arrests the S phase cell cycle growth at low micromolar concentrations. The ADMET properties have ascertained their inherent pharmacokinetic potentiality, and the wholesome results prompted us to report it as the first study on anti-pancreatic cancer activity of cyclic α-aminophosphonates. Ultimately, this study serves as a good contribution to update the existing knowledge on the anticancer organophosphorus heterocyclic compounds and elevates the scope for generation of new anticancer drugs. Further, the studies like QSAR, drug properties, toxicity risks, and bioactivity scores predicted for them have ascertained the synthesized compounds as newer and potential drug candidates. Hence, this study had augmented the array of α-aminophosphonates by adding a new collection of 3-amino-2-hydroxybenzofused 2-phosphalactones, a class of cyclic α-aminophosphonates, to it, which proved them as potential anti-pancreatic cancer agents. ©Mr. R.R.G. and Prof. S.R.C. thank Science and Engineering Research Board (SERB), India for providing financial assistance through a research project grant f.no.: SB/S1/OC-96/2013, Dt: 05-11-2014. Author S.K.B. thanks University Grants Commission (UGC), New Delhi, India for RFSMS (Research Fellowship in Sciences for Meritorious Students) Fellowship (F.4-1/2011, BSR-RFSMS-BSK) under Basic Scientific Research (BSR) Scheme. Authors V.K.R.A. and G.V.Z. are thankful to Ural Federal University for support and acknowledge the financial support of the Ministry of Science and Higher Education of the Russian Federation, Moscow, Russian Federation (grant no.: 075-15-2020-777)

Prognostic model to predict postoperative acute kidney injury in patients undergoing major gastrointestinal surgery based on a national prospective observational cohort study.

Background: Acute illness, existing co-morbidities and surgical stress response can all contribute to postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery. The aim of this study was prospectively to develop a pragmatic prognostic model to stratify patients according to risk of developing AKI after major gastrointestinal surgery. Methods: This prospective multicentre cohort study included consecutive adults undergoing elective or emergency gastrointestinal resection, liver resection or stoma reversal in 2-week blocks over a continuous 3-month period. The primary outcome was the rate of AKI within 7 days of surgery. Bootstrap stability was used to select clinically plausible risk factors into the model. Internal model validation was carried out by bootstrap validation. Results: A total of 4544 patients were included across 173 centres in the UK and Ireland. The overall rate of AKI was 14·2 per cent (646 of 4544) and the 30-day mortality rate was 1·8 per cent (84 of 4544). Stage 1 AKI was significantly associated with 30-day mortality (unadjusted odds ratio 7·61, 95 per cent c.i. 4·49 to 12·90; P < 0·001), with increasing odds of death with each AKI stage. Six variables were selected for inclusion in the prognostic model: age, sex, ASA grade, preoperative estimated glomerular filtration rate, planned open surgery and preoperative use of either an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker. Internal validation demonstrated good model discrimination (c-statistic 0·65). Discussion: Following major gastrointestinal surgery, AKI occurred in one in seven patients. This preoperative prognostic model identified patients at high risk of postoperative AKI. Validation in an independent data set is required to ensure generalizability

The Changing Landscape for Stroke\ua0Prevention in AF: Findings From the GLORIA-AF Registry Phase 2

Background GLORIA-AF (Global Registry on Long-Term Oral Antithrombotic Treatment in Patients with Atrial Fibrillation) is a prospective, global registry program describing antithrombotic treatment patterns in patients with newly diagnosed nonvalvular atrial fibrillation at risk of stroke. Phase 2 began when dabigatran, the first non\u2013vitamin K antagonist oral anticoagulant (NOAC), became available. Objectives This study sought to describe phase 2 baseline data and compare these with the pre-NOAC era collected during phase&nbsp;1. Methods During phase 2, 15,641 consenting patients were enrolled (November 2011 to December 2014); 15,092 were eligible. This pre-specified cross-sectional analysis describes eligible patients\u2019 baseline characteristics. Atrial fibrillation&nbsp;disease characteristics, medical outcomes, and concomitant diseases and medications were collected. Data were analyzed using descriptive statistics. Results Of the total patients, 45.5% were female; median age was 71 (interquartile range: 64, 78) years. Patients were from Europe (47.1%), North America (22.5%), Asia (20.3%), Latin America (6.0%), and the Middle East/Africa (4.0%). Most had high stroke risk (CHA2DS2-VASc [Congestive heart failure, Hypertension, Age&nbsp; 6575 years, Diabetes mellitus, previous Stroke, Vascular disease, Age 65 to 74 years, Sex category] score&nbsp; 652; 86.1%); 13.9% had moderate risk (CHA2DS2-VASc&nbsp;= 1). Overall, 79.9% received oral anticoagulants, of whom 47.6% received NOAC and 32.3% vitamin K antagonists (VKA); 12.1% received antiplatelet agents; 7.8% received no antithrombotic treatment. For comparison, the proportion of phase 1 patients (of N&nbsp;= 1,063 all eligible) prescribed VKA was 32.8%, acetylsalicylic acid 41.7%, and no therapy 20.2%. In Europe in phase 2, treatment with NOAC was more common than VKA (52.3% and 37.8%, respectively); 6.0% of patients received antiplatelet treatment; and 3.8% received no antithrombotic treatment. In North America, 52.1%, 26.2%, and 14.0% of patients received NOAC, VKA, and antiplatelet drugs, respectively; 7.5% received no antithrombotic treatment. NOAC use was less common in Asia (27.7%), where 27.5% of patients received VKA, 25.0% antiplatelet drugs, and 19.8% no antithrombotic treatment. Conclusions The baseline data from GLORIA-AF phase 2 demonstrate that in newly diagnosed nonvalvular atrial fibrillation patients, NOAC have been highly adopted into practice, becoming more frequently prescribed than VKA in&nbsp;Europe and North America. Worldwide, however, a large proportion of patients remain undertreated, particularly in&nbsp;Asia&nbsp;and North America. (Global Registry on Long-Term Oral Antithrombotic Treatment in Patients With Atrial Fibrillation [GLORIA-AF]; NCT01468701