Optimal Ball-end and Fillet-end Mills Selection for 3-Axis Finish Machining of Point-based Surface

Kayal, Prasenjit Society for Computational Design and Engineering 2007 International Journal of CAD/CAM Vol.7 No.1

This paper presents an algorithm of optimal cutting tool selection for machining of the point-based surface that is defined by a set of surface points rather than parametric polynomial surface equations. As the ball-end and fillet-end mills are generally used for finish machining in a 3-axis computer numerical control machine, the algorithm is applicable for both cutters. The optimum tool would be as large as possible in terms of the cutter radius and/or corner radius which maximise (s) the material removal rate (i.e., minimise (s) the machining time), while still being able to machine the entire point-based surface without gouging any surface point. The gouging are two types: local and global. In this paper, the distance between the cutter bottom and surface points is used to check the local gouging whereas the shortest distance between the surface points and cutter axis is effectively used to check the global gouging. The selection procedure begins with a cutter from the tool library, which has the largest cutter radius and/or corner radius, and then adequacy of the point-density is checked to limit the accuracy of the cutter selection for the point-based surface within tolerance prior to the gouge checking. When the entire surface is gouge-free with a chosen cutting tool then the tool becomes the optimum cutting tool for a list of cutters available in the tool library. The effectiveness of the algorithm is demonstrated considering two examples.

A HYPOTHESIS TESTING PROCEDURE OF ASSESSMENT FOR THE LIFETIME PERFORMANCE INDEX UNDER A GENERAL CLASS OF INVERSE EXPONENTIATED DISTRIBUTIONS WITH PROGRESSIVE TYPE I INTERVAL CENSORING

KAYAL, TANMAY,TRIPATHI, YOGESH MANI,WU, SHU-FEI The Korean Society for Computational and Applied M 2019 Journal of applied mathematics & informatics Vol.37 No.1

One of the main objective of manufacturing industries is to assess the capability performance of different processes. In this paper, we use the lifetime performance index $C_L$ as a criterion to measure larger-the-better type quality characteristic for evaluating the product performance. The lifetimes of products are assumed to follow a general class of inverted exponentiated distributions. We use maximum likelihood estimator to estimate the lifetime performance index under the assumption that data are progressive type I interval censored. We also obtain asymptotic distribution of this estimator. Based on this estimator, a new hypothesis testing procedure is developed with respect to a given lower specification limit. Finally, two numerical examples are discussed in support of the proposed testing procedure.

Inverse Offset Method for Adaptive Cutter Path Generation from Point-based Surface

Kayal, Prasenjit Society for Computational Design and Engineering 2007 International Journal of CAD/CAM Vol.7 No.1

The inverse offset method (IOM) is widely used for generating cutter paths from the point-based surface where the surface is characterised by a set of surface points rather than parametric polynomial surface equations. In the IOM, cutter path planning is carried out by specifying the grid sizes, called the step-forward and step-interval distances respectively in the forward and transverse cutting directions. The step-forward distance causes the chordal deviation and the step-forward distance produces the cusp. The chordal deviation and cusp are also functions of local surface slopes and curvatures. As the slopes and curvatures vary over the surface, different step-forward and step-interval distances are appropriate in different areas for obtaining the machined surface accurately and efficiently. In this paper, the chordal deviation and cusp height are calculated in consideration with the surface slopes and curvatures, and their combined effect is used to estimate the machined surface error. An adaptive grid generation algorithm is proposed, which enables the IOM to generate cutter paths adaptively using different step-forward and step-interval distances in different regions rather than constant step-forward and step-interval distances for entire surface.

A HYPOTHESIS TESTING PROCEDURE OF ASSESSMENT FOR THE LIFETIME PERFORMANCE INDEX UNDER A GENERAL CLASS OF INVERSE EXPONENTIATED DISTRIBUTIONS WITH PROGRESSIVE TYPE I INTERVAL CENSORING

TANMAY KAYAL,Yogesh Mani Tripathi,Shu-Fei Wu 한국전산응용수학회 2019 Journal of applied mathematics & informatics Vol.37 No.1

One of the main objective of manufacturing industries is to assess the capability performance of dierent processes. In this paper, we use the lifetime performance index CL as a criterion to measure larger-thebetter type quality characteristic for evaluating the product performance. The lifetimes of products are assumed to follow a general class of inverted exponentiated distributions. We use maximum likelihood estimator to estimate the lifetime performance index under the assumption that data are progressive type I interval censored. We also obtain asymptotic distribution of this estimator. Based on this estimator, a new hypothesis testing procedure is developed with respect to a given lower specication limit. Finally, two numerical examples are discussed in support of the proposed testing procedure.

Evaluation of antibacterial activity and cytotoxic effects of green AgNPs against Breast Cancer Cells (MCF 7)

Vizhi, Dhandapani Kayal,Supraja, Nookala,Devipriya, Anbumani,Tollamadugu, Naga Venkata Krishna Vara Prasad,Babujanarthanam, Ranganathan Techno-Press 2016 Advances in nano research Vol.4 No.2

The present work reports a facile, rapid and an eco-friendly method for the synthesis of silver nanoparticles using Luffa acutangula (L. acutangula) leaves extract and their antibacterial and cytotoxic effects. The synthesized silver nanoparticles (AgNPs) were characterized by UV-Visible spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction analysis (XRD). Additionally the topography, morphology and the elemental composition of the particles were determined by Scanning Electron Microscopy (SEM) and Energy dispersive spectrophotometric (EDS) technique and the measured particle sizes from SEM micrographs are in the range of 12.5 to 24.5nm. The in-vitro antimicrobial activity of the synthesized nanoparticles was high against gram positive Staphylococcus aureus and moderate against gram negative Escherichia coli and Pseudomonas aeruginosa strains. Further, the cytotoxic effects of synthesized AgNPs were evaluated against Human Breast Cancer (MCF 7) cell line.

Investigation of dispersion behaviour of SiC in water for slip casting of SiC

N. Vijaya Lakshmi,Atanu Dey,Nijhuma Kayal,Omprakash Chakrabarti 한양대학교 세라믹연구소 2014 Journal of Ceramic Processing Research Vol.15 No.2

The aim of the present work was to identify the conditions for the preparation of stable SiC slurries for fabrication of slip cast object and to correlate the slurry properties to the final properties of the ceramics. An ammonium salt of polymethacrylic acid was used as dispersant for SiC slurry. The effects of dispersant concentration and pH on the rheological behaviour of SiC suspension were studied. The slurry stability was evaluated by measuring settling of the powder as a function of time. The addition of dispersant improved the dispersion by increasing the negative zeta potential of SiC particles. The best conditions of stable slurry were selected on the basis of low viscosity and minimum settling of the powder. It was observed that 1 wt% dispersant resulted lowest viscosity for the slurry of 70 wt% solids loading. The properties of the slip cast object were compared with powder pressed object and it was observed that slip cast object exhibited better mechanical strength due to homogeneous powder packing.

Microscopic varicocelectomy as a treatment option for patients with severe oligospermia

Chirag Gupta,Arun Chinchole,Rupin Shah,Hemant Pathak,Deepa Talreja,Ankit Kayal 대한비뇨의학회 2018 Investigative and Clinical Urology Vol.59 No.3

Purpose: Many studies have shown improved semen parameters after varicocele surgery; however, the benefit in terms of improved pregnancy rates and live births is still disputed in cases of severe oligoasthenozoospermia (OAS). The present study evaluated the outcome of microscopic subinguinal varicocelectomy in terms of the spontaneous pregnancy rate in patients with severe OAS. Materials and Methods: This was a retrospective, observational, analytic study of 56 men with OAS who underwent microscopic varicocelectomy at our center between 2008 and 2015. The subjects were followed for a mean period of 12.4 months. Outcome was compared among groups of men with mild (sperm concentration, 10.2–19 million/mL), moderate (5.7–9.5 million/mL), and severe (<5 million/mL) OAS who were operated on during the same period. Results: A total of 13 of 35 men (37.1%) with severe OAS achieved spontaneous pregnancy. Mean sperm density increased from 2.29 million/mL preoperatively to 14.09 million/mL postoperatively. The mean time to pregnancy from the date of surgery was 8.5 months. The spontaneous pregnancy rate in men with mild and moderate OAS was 62.5% and 46.2%, respectively. Conclusions: Although pregnancy rates after varicocele surgery are lower preoperatively in men with severe OAS than in men with mild or moderate OAS, the spontaneous pregnancy rate of 37.1% still compares very favorably with outcomes after a single attempt at in vitro fertilization.

Microtubular Dysfunction and Male Infertility

Sezgin Gunes,Pallav Sengupta,Ralf Henkel,Aabed Alguraigar,Mariana Marques Sinigaglia,Malik Kayal,Ahmad Joumah,Ashok Agarwal 대한남성과학회 2020 The World Journal of Men's Health Vol.38 No.1

Microtubules are the prime component of the cytoskeleton along with microfilaments. Being vital for organelle transport and cellular divisions during spermatogenesis and sperm motility process, microtubules ascertain functional capacity of sperm. Also, microtubule based structures such as axoneme and manchette are crucial for sperm head and tail formation. This review (a) presents a concise, yet detailed structural overview of the microtubules, (b) analyses the role of microtubule structures in various male reproductive functions, and (c) presents the association of microtubular dysfunctions with male infertility. Considering the immense importance of microtubule structures in the formation and maintenance of physiological functions of sperm cells, this review serves as a scientific trigger in stimulating further male infertility research in this direction.

Efficacy of two traditionally used potentized homeopathic medicines, Calcarea carbonica and Lycopodium clavatum, used for treating PCOS patients: I. Effects on certain important external guiding symptoms

Debarsi Das,Indira Das,Jayeeta Das,Saroj Kumar Kayal,Anisur Rahman Khuda-Bukhsh 셀메드 세포교정의약학회 2016 셀메드 (CellMed) Vol.6 No.1

Polycystic Ovarian Syndrome (PCOS) has now become more common in occurrence in women of reproductive age, particularly in urban and semi-urban population in India. So there is a need to investigate this phenomenon taking into consideration various aspects including possible treatment method to ameliorate/eradicate this syndrome, which has far reaching socio-economic impact and consequences, in view of infertility and irregular menstrual cycles frequently associated with this syndrome. Homeopathy is a branch of traditional alternative medicine which is gaining popularity in India and some other developing countries, as also in some of the developed countries in Europe. With this background scenario, we have made an attempt to treat cases of confirmed PCOS and tried to compare the relative efficacy of two potentized homeopathic drugs, namely, Lycopodium clavatum (Lyco) and Calcarea carbonica (Calc), most frequently used by homeopathic practitioners, selecting different potencies of the drugs, depending on condition/guiding symptom(s) of the patients. While the main focus was pointed on total/partial removal of cysts, data pertaining to different PCOS associated symptoms were also compared for the sake of learning if the two drugs had differential effects on these symptoms also. The study parameters in this investigation included: regularity/irregularity of menstrual cycle, presence/absence of acne, hirsutism, male type alopecia, acanthosis nigricans, body/mass index (BMI) and waist-hip ratio. Overall results provided clear evidences that both these homeopathic drugs had great ameliorating effects on PCOS, although each drug had a little different effect in respect of the individual parameters of this study.