Formability of Metal-Matrix Composite based on Aluminium Alloy 6061 - Reinforced with Silicon Carbide Particulars

Aluminium alloy reinforced with hard ceramic materials has improved specific strength, specific modulus and wear resistance . Increasing amount of these reinforcing materials decreases ductility and CTE values . Many of these properties are desirable in aerospace , marine and automotive applications . There is no substantial data available as regards to forming characteristics of newly developed composite alloy.The present work has been undertaken with a view to assess quantitatively the forming behavior of 6061-Al/SiCPcomposites developed through conventional casting routes.The cast composites were upset tested and drawn during study of formability. Ring compression tests developed by Male and Cockcroft have been used for determining the friction factor during upsetting of rings . The reduction capacity test was modelled using Avitzur 's equations for forging of thin discs to estimate friction factor during upset forging a solid cylindrical disk under dry conditions . Friction factor has been estimated using a computer based on equation developed by Venugopal et al.Increasing silicon carbide content from 10 vol% to 20 vol% resulted in decreased formability based on upset test. Initially this decrease was of the order of 20% which later decreased by 25%. The rate of decrease of formability was more pronounced beyond 15 vol% of silicon carbide particulate addition . Paper reports the systematic investigation carried out with composite rings of geometry 6:3:2 (OD:ID:Height) under different lubricating conditions to estimate co-efficient of friction.Interfacial frictional value decreased on changing the lubricating conditions from dry to 220 grade lubricant, and this was of the order of 20-25%. Lubricant 220 and furnace oil were foun to have similar characteristics between 25-45% deformation in height. Paper also reports the results of reduction capacity test during upset forging of samples with aspect ratio of 2 and 2.5. It was revealed that the friction factor has strong dependence on deformation percentage. The friction factors determined by means of ring compression test and reduction capacity test with aspect ratio 2 are not in good agreement in cast Al 6061-SIC r composite, however, they are very close when aspect ratio was increased to 2.5. Further work on forming behaviour of the composite is in progress and it is expected that these will fill up the existing gap in the development of metal matrix composites

DEVELOPMENT AND VALIDATION OF A STABILITY INDICATING LIQUID CHROMATOGRAPHIC METHOD FOR THE SIMULTANEOUS ESTIMATION OF PAROXETINE AND CLONAZEPAM IN BULK AND ITS PHARMACEUTICAL FORMULATIONS

A novel stability indicating reversed-phase liquid chromatographic method has been developed and validated for simultaneous estimation of paroxetine and clonazepam in combined pharmaceutical dosage form. An Agilent zorbax sb-c18 (250mmx4.6mmx5 µm) column with the mobile phase containing 0.2 % Orthophosphoric acid and Methanol (60:40 v/v) was used. The flow rate was maintained at 0.8 ml/min, column temperature was 30°C and effluents were monitored by using a photodiode array detector at 270 nm. The retention times of paroxetine and clonazepam were found to be 3.478min and 3.964 min, respectively. Correlation co-efficient for paroxetine and clonazepam were found to be 0.99 and 0.99, respectively. The proposed method was validated with respect to linearity, accuracy, precision, specificity, and robustness. Recovery of paroxetine and clonazepam in formulations was found to be in a range of 97-103% and 97-103% respectively. Paroxetine and clonazepam were also subjected to the stress conditions of oxidative, acid, base, hydrolytic, thermal and photolytic degradation. The degradation products were well resolved from and peak purity test results confirmed that paroxetine and clonazepam peaks were homogenous and pure in all stress samples, thus proving stability-indicating power of the method. Due to its simplicity, rapidness and high precision, this method can be applied for regular analysis

Experimental Study and Optimization of Machining Parameters in Turning of AISI 1040 Steel with Micro-grooved WC Cutting Tools

In dry turning, control over chip formation and the need for the automated machining lead to an advancement in cutting tools. Such concern towards chip breakability is necessary in reducing tool wear, tool tip temperatures and surface roughness of workpiece material. The present study proposes a new development in the traditionally available cutting tools, which acts like a chip breaker. A series of micro-grooves are machined on the rake face of Tungsten carbide (WC) cutting tools using sinker Electric Discharge Machine (EDM). These micro-grooved tools are used to dissolve long continuous chips and heat from the cutting zone in the dry machining of AISI 1040 steel. The results of micro-grooved cutting tools have shown improvement in reducing the tool tip temperatures and surface roughness compared to the conventional cutting tools. The consolidated chip flow phenomenon of plain WC tools is used to decide the location of micro-grooves on the tool rake face. A Taguchi orthogonal array is used to design an experimental layout with minimum number of repetitions in the experiments. Signal-to-noise  ratios and ANOVA is used to understand and identify the significant factors & their level among the input variables on responses.From the results, it is identified that the cutting speed is the most influencing parameter for tool tip temperature at level 1 (i.e. 112 m/min) and surface roughness at level 5 (i.e. 720 m/min)

Female sexual dysfunction amongst rural postmenopausal woman

Background: Female Sexual dysfunction is a common neglected symptom of postmenopausal women in rural India. Prevalence of sexual dysfunction increases with age and sexual response is dynamic process influenced by socio-cultural, physiological, psychological and socio-economical factors. The objective of the study was to analyse the prevalence of female sexual dysfunctions in postmenopausal women from rural area and to analyze prevalence of sexual activity among them.Methods: A cross-sectional study was conducted from June 2015 to January 2016 in Obstetrics and Gynecology outpatient department of Indian Institute of Medical Science and Research, Badnapur, Jalna, Maharashtra which is a tertiary care centre. All postmenopausal women who have attained menopause naturally were questioned about sexual symptoms with the help of pre-tested questionnaires and then analyzed with appropriate tests.Results: Mean age of menopause was 47.59±3.98 yrs and 51.9% were sexually active. Mean age among sexual active and sexual inactive women was 54.42±5.23 and 62.13±6.39 respectively. Prevalence of dyspareunia, vaginal dryness and decreased libido were 10.7%, 10.7% and 55.36% respectively in sexually active postmenopausal women. Sexual activity decreased from 54.4% to 5.6% as the duration of menopause increased from 5 years or less to 11 or more years. Sexual dysfunction increased as the duration of menopause increased.Conclusions: Sexual dysfunction is common in postmenopausal women and increases with increasing duration of menopause. Awareness of health care facility among rural menopausal women should be increased to improve their quality of life

Similarity classes of 3x3 matrices over a local principal ideal ring

In this paper similarity classes of three by three matrices over a local principal ideal commutative ring are analyzed. When the residue field is finite, a generating function for the number of similarity classes for all finite quotients of the ring is computed explicitly.Comment: 14 pages, final version, to appear in Communications in Algebr

Study of biosocial factors affecting laparoscopic tubal ligation in rural Maharashtra, India

Background: As compared to vasectomy, Indian women prefer female sterilization as the best mode sterilization. Many socio-demographic factors and gender of living children affects women in deciding laparoscopic tubal ligation.Objective of the study was to assess the biosocial factors affecting of laparoscopic tubal ligation patients in rural area and also to asses average family size and preference for male child before laparoscopic tubal ligation.Methods: A cross-sectional study was done during January to June 2016 in Indian Institute of Medical Science and Research medical College, Badnapur, Jalna, Maharashtra. A total of 549 patients from rural area, underwent laparoscopic tubal ligation were enrolled for the study. Data was analyzed by using percentage and proportion whenever necessary.Results: In this study, mean age of patients undergoing tubal ligation was 26.37±3.82 year. Maximum patients were from 25-29 years age group and among them 45.54% were illiterates. Average family size was 2.61±0.66. In 51.73% cases, couple themselves motivated for their sterilization. Education of both participant and their husband was significantly related to the total no. of living children. Only 9 patients under went tubal ligation with only 1 male child, while all other couples had at least one male child in the family.Conclusions: The study reveals that all couple had at least one male child. Education of both participant and their husband was an important factor in deciding the size of family.

Monopole Vacuum in Non-Abelian Theories

It is shown that, in the theory of interacting Yang -Mills fields and a Higgs field, there is a topological degeneracy of Bogomol'nyi-Prasad-Sommerfield (BPS) monopoles and that there arises, in this case, a chromoelectric monopole characterized by a new topological variable that describes transitions between topological states of the monopole in the Minkowski space (in just the same way as an instanton describes such transitions in the Euclidean space). The limit of an infinitely large mass of the Higgs field at a finite density of the BPS monopole is considered as a model of the stable vacuum in the pure Yang-Mills theory. It is shown that, in QCD, such a monopole vacuum may lead to a rising potential, a topological confinement and an additional mass of the $\eta_0$ meson. The relationship between the result obtained here for the generating functional of perturbation theory and Faddeev-Popov integral is discussed

Identification of blast resistance expression in rice genotypes using molecular markers (RAPD & SCAR)

Rice is the second most important cereal crop of developing countries and the staple food of about 65% of the world’s population. In this endeavor, it is important to identify resistant gene(s) with the help of markers. Once a gene is tagged with a molecular marker, it can be transferred selectively into different genetic backgrounds by marker assisted selection. For this purpose, 48 elite Indian and exotic rice genotypes were evaluated for resistance to blast disease under induced epiphytotic conditions obtained in the field. The disease severity (%) and AUDPC was less than 45% and 1000, respectively, in all the resistant genotypes, while it was around 85% and higher than 2000 in the case of susceptible genotypes, respectively. Substantial variability was present among rice genotypes for resistance toMagnaporthe grisea. Ten random amplified polymorphic DNAs (RAPD) and two sequence characterized amplified region (SCAR) primers were used to identify blast resistant genes. Markers OPA-05, OPF-06, OPF-09, OPF-17, OPG-17, OPG-18, OPG-19, OPH-18, OPK-12, P-265-550 and P-286-350 found linked to blast resistance in most of the resistant genotypes could be considered as potent molecular markers in the selection of blast resistant genotypes. Amplification with RAPD and SCAR primers revealed a nonallelic relationship among resistant genotypes and thus, there is a good possibility of obtaining enhanced resistance through gene pyramiding