Reliability models applicable to space telescope solar array assembly system

A complex system may consist of a number of subsystems with several components in series, parallel, or combination of both series and parallel. In order to predict how well the system will perform, it is necessary to know the reliabilities of the subsystems and the reliability of the whole system. The objective of the present study is to develop mathematical models of the reliability which are applicable to complex systems. The models are determined by assuming k failures out of n components in a subsystem. By taking k = 1 and k = n, these models reduce to parallel and series models; hence, the models can be specialized to parallel, series combination systems. The models are developed by assuming the failure rates of the components as functions of time and as such, can be applied to processes with or without aging effects. The reliability models are further specialized to Space Telescope Solar Arrray (STSA) System. The STSA consists of 20 identical solar panel assemblies (SPA's). The reliabilities of the SPA's are determined by the reliabilities of solar cell strings, interconnects, and diodes. The estimates of the reliability of the system for one to five years are calculated by using the reliability estimates of solar cells and interconnects given n ESA documents. Aging effects in relation to breaks in interconnects are discussed

Analysis on Role of E-Commerce in Reducing Operational Cost

E-commerce means electronic commerce. E-commerce involves carrying on a business with help of the internet and by using the information technology like Electronic Data Interchange (EDI). E-commerce relates to a websites of the vendor on the internet, who trades products or services directly to the customer from the portal. The portal uses a digital shopping cart or digital basket system and allows payment through credit, debit card or EFT (Electronic fund transfer) payments

Herbo-Mineral formulation in Rasa Raktavaha Srothas w.s.r. to Twacha Vikaras - A Review

Ayurveda is the ancient science of medicine with number of unique drugs and formulations in its armory. The formulation / drugs which are prepared and practiced classically whose efficacy and potency were well established. And these formulations / drugs belonging to plant, animal and mineral origin. The formulation which are prepared out of these origins are used in the management of various Twacha Vikaras. Skin is the largest covering of the body. According to Ayurveda, Twacha is originated from Matruja Bhavas and formed like the butter forming on the boiling milk

Clinicopathological study of hysterectomised specimens

Background: Hysterectomy is the commonest major surgical procedure performed in gynecology. It can be done by abdominal or vaginal route and with the help of laparoscopy. Hysterectomy is an effective treatment option for many conditions like fibroid, abnormal uterine bleeding, endometriosis, adenomyosis, uterine prolapse, pelvic inflammatory disease and cancer of reproductive organ when other treatment options are contraindicated or have failed, or if the woman no longer wishes to retain her menstrual and reproductive. The aim and objective of the study was to correlate indications of hysterectomy with histopathological findings in hysterectomised patients.Methods: A retrospective study was carried on 113 hysterectomised cases over a period of one year from June 2015 to May 2016. The data regarding the patient’s age, parity, clinical diagnosis, type of hysterectomy and histopathological diagnosis were reviewed by the records and analyzed.Results: A total of 113 cases of hysterectomies were studied. Hysterectomies were distributed over a wide age ranging from 20 years to 75 years. Most common age group was 41-50 years. Among hystectomies majority were done through vaginal route 86 (76.1%) and 26 (23%) cases were done through abdominal route. Most common clinical diagnosis was fibroid uterus in 44(38.9%) cases. Most of the hysterectomies were done for benign conditions. In final histopathological report most common diagnosis was fibroid uterus in 45(39.8%) hysterectomy specimens. It was correlated well with clinical diagnosis. Next most common histopathological diagnosis was Adenomyosis.Conclusions: Histopathological analysis correlated well with preoperative clinical diagnosis in majority of cases. The commonest indication and histopathological finding in our study was fibroid uterus. Next most common histopathological finding was Adenomyosis. Most commonly hysterectomies were done through vaginal route in our study

The Cosmology of Massless String Modes

We consider the spacetime dynamics of a gas of closed strings in the context of General Relativity in a background of arbitrary spatial dimensions. Our motivation is primarily late time String Gas Cosmology, where such a spacetime picture has to emerge after the dilaton has stabilized. We find that after accounting for the thermodynamics of a gas of strings, only string modes which are massless at the self-dual radius are relevant, and that they lead to a dynamics which is qualitatively different from that induced by the modes usually considered in the literature. In the context of an ansatz with three large spatial dimensions and an arbitrary number of small extra dimensions, we obtain isotropic stabilization of these extra dimensions at the self-dual radius. This stabilization occurs for fixed dilaton, and is induced by the special string states we focus on. The three large dimensions undergo a regular Friedmann-Robertson-Walker expansion. We also show that this framework for late-time cosmology is consistent with observational bounds.Comment: 15 pages, no figures, references added (again

Statistical analysis of failure data on controllers and SSME turbine blade failures

The expressions for the maximum likelihood functions are given when the failure data are censored at a given point or at multiple points, or when the data come in groups. Different models applicable to failure data are presented with their characteristics. A graphical method of distinguishing different models by using cumulative hazard fucnction is discussed. For the failure data on controllers the model is determined by cumulative hazard function and chi-square goodness of fit. Using the Weibull Model the maximum likelihood estimators of the shape parameter and the failure rate parameter are obtained. The confidence intervals, meantime between failures, and B1 are determined. Similarly, for the data on Space Shuttle Main Engine (SSME) blade failures the maximum likelihood estimators are obtained for the Weibull parameters. The variances, confidence intervals, meantime between failures, and reliability are determined. The analysis is performed under assumption of grouped data as well as randomly placed data

Nondescent vaginal hysterectomy: analysis of indications and complications

Background: Hysterectomy is the commonest major surgical procedure performed in gynecology. It can be done by abdominal or vaginal route and with the help of laparoscopy. Laparoscopic assisted vaginal hysterectomy (LAVH) and total laparoscopic hysterectomy (TLH) although gaining more popularity now a days, though it is associated with higher cost, longer duration of operation, and need general anaesthesia. The latest value study concluded that major haemorrhage, hematoma, ureteric injury, bladder injury, and anesthetic complications were more in laparoscopic assisted hysterectomy (LAVH) group when compared to abdominal and vaginal hysterectomies. In addition LAVH was accomplished in twice the time required for vaginal hysterectomy.The objective of the study was to analyse the indication and to study the complications of nondescent vaginal hysterectomy.Methods: This is a retrospective cohort study.  60 women who underwent nondescent vaginal hysterectomy in the department of OBG, B.G.S. Global Institute of Medical Sciences, Banglore, India were included in the study. Patients’ records were retrieved. Data regarding patient’s age, parity, indications for hysterectomy, uterine size in weeks, previous surgeries in the past, duration of surgery and complications were recorded. Data collected on a semi structured proforma and the same was analysed using suitable statistical analysis.Results: A total of 60 cases were operated for different indications. Among the study participants majority were in the age group of 41-45 years with 28 (46.7%). Most common indication for hysterectomies were dysfunctional uterine bleeding (DUB) with 27 (45%), followed by fibroid uterus 15 (25%). The mean duration of surgery time taken was 50+10minutes. Majority of the women who underwent hysterectomies had bulky uterus with 42 (70%).  Complications were very few. Fever, UTI (urinary tract infection) and headache were seen in 3 (5%) cases. There was one case of vault sepsis and one case of upper respiratory tract infection (URTI). In one patient vaginal hysterectomy could not be completed and abdominal hysterectomy was carried out. Mean hospital duration was 4 days.Conclusions: Vaginal hysterectomy is the least invasive with fewer complications and most economical route for hysterectomy. Nondescent vaginal hysterectomy should be the gynaecologists first choice for hysterectomy

A rare cause of epididymo-orchitis

Epididymo-orchitis is an inflammatory lesion of the testis and epididymis with a lymphocytic exudate. Patients with acute epididymo-orchitis typically present with scrotal pain, swelling, tenderness and fever. Here, we present a patient with scrotal pain and hemiscrotal swelling as the main complaints; however further investigations revealed a completely different and rare diagnosis. Zinner’s syndrome is a very rare developmental anomaly of the Wolffian duct. To date, only about 200 cases have been diagnosed. It is a triad of unilateral renal agenesis, ipsilateral seminal vesicle cyst and ejaculatory duct obstruction. Some patients remain asymptomatic and discovered incidentally, while others present with symptoms related to seminal vesicle cysts or ejaculatory duct obstruction: voiding or ejaculatory difficulty or pain. Treatment options include transurethral or transrectal aspiration and percutaneous drainage, however both are linked to an increased risk of recurrence. Symptomatic, complicated and recurrent cyst will require excision of the cyst, either laparoscopically or robotically

Traditional Medicolore in Badwani District (M.P.) India

The study concerns significant ethnobotanical information of 25 plant species belonging to 25 genera and 19 families traditionally used by the aborigines and rural folks of Badwani district, Of these 21 species are being noted for the first time from Indian region.  Madhya Pradesh (India) to treat various human diseases such as, impotency, intestinal worms, fever, constipation, ring worms, eczema, hepatitis, menstrual complaints, urinary complaints, migraine stomach-ache, bone fracture, lactation, piles, night blindness, pregnancy and abortion, etc.,This paper highlights traditional uses of plants used by the rural and tribal people. The district is inhabited with tribes viz., Gond, Baiga, Koraku, Bhariaya, Halba, Bhil, Kaul and Pawara. The population of the region is predominantly rural and tribal having considerable knowledge about ambient plant wealth and their traditional utility. The present work is an attempt to collect document and evaluate the ethnomedicinal claims in the areas under study. Key words: Ethnomedicine, Badwani District, Madhya Pradesh P. S. Patil. Traditional Medicolore in Badwani District (M.P.) India. J Phytol 2/12 (2010) 49-53