2,741 research outputs found
A robust sequential hypothesis testing method for brake squeal localisation
This contribution deals with the in situ detection and localisation of brake squeal in an automobile. As brake squeal is emitted from regions known a priori, i.e., near the wheels, the localisation is treated as a hypothesis testing problem. Distributed microphone arrays, situated under the automobile, are used to capture the directional properties of the sound field generated by a squealing brake. The spatial characteristics of the sampled sound field is then used to formulate the hypothesis tests. However, in contrast to standard hypothesis testing approaches of this kind, the propagation environment is complex and time-varying. Coupled with inaccuracies in the knowledge of the sensor and source positions as well as sensor gain mismatches, modelling the sound field is difficult and standard approaches fail in this case. A previously proposed approach implicitly tried to account for such incomplete system knowledge and was based on ad hoc likelihood formulations. The current paper builds upon this approach and proposes a second approach, based on more solid theoretical foundations, that can systematically account for the model uncertainties. Results from tests in a real setting show that the proposed approach is more consistent than the prior state-of-the-art. In both approaches, the tasks of detection and localisation are decoupled for complexity reasons. The localisation (hypothesis testing) is subject to a prior detection of brake squeal and identification of the squeal frequencies. The approaches used for the detection and identification of squeal frequencies are also presented. The paper, further, briefly addresses some practical issues related to array design and placement. (C) 2019 Author(s)
Bio-bibliometric Study of Prof. P Balaram contributions in the field of Bio-organic Chemistry and Molecular Biophysics
The present study uses Bio-Bibliometrics to examine the contributions made by Prof P Balaram renowned scientists in the field of Bio-organic chemistry and molecular biophysics from Indian Institute of Science (IISC) in India. It is important to study the contributions made by him to understand magnitudes and nature of contribution in a particular domain. The data was collected using Scopus database. Further the paper highlights on the contributions of P Balaram author productivity, Collaborations magnitude, Productivity of year wise distribution, collaboration coefficient, channels of communications, most used author keywords and high cited papers
Modulation of Gi Proteins in Hypertension: Role of Angiotensin II and Oxidative Stress
Guanine nucleotide regulatory proteins (G-proteins) play a key role in the regulation of various signal transduction systems including adenylyl cyclase/cAMP and phospholipase C (PLC)/phosphatidyl inositol turnover (PI). These are implicated in the modulation of a variety of physiological functions such as platelet functions, cardiovascular functions, including arterial tone and reactivity. Several abnormalities in adenylyl cyclase activity, cAMP levels and G proteins have shown to be responsible for the altered cardiac performance and vascular functions observed in cardiovascular disease states. The enhanced or unaltered levels of inhibitory G-proteins (Giα-2 and Giα-3) and mRNA have been reported in different models of hypertension, whereas Gsα levels were shown to be unaltered. These changes in G-protein expression were associated with Gi functions. The enhanced levels of Giα proteins precede the development of blood pressure and suggest that overexpression of Gi proteins may be one of the contributing factors for the pathogenesis of hypertension. The augmented levels of vasoactive peptides, including angiotensin II (AngII), were shown to contribute to enhanced expression of Giα proteins and associated adenylyl cyclase signaling and thereby increased blood pressure. In addition, enhanced oxidative stress in hypertension due to Ang II may also be responsible for the enhanced expression of Giα proteins observed in hypertension. The mechanism by which oxidative stress enhances the expression of Gi proteins appears to be through the activation of mitogen activated protein (MAP) kinase activity
Content Analysis of Library Websites of National Institute of Pharmaceutical Education and Research (NIPER’s) Institutes of India: An Evaluative study
The study undertook to examine the library websites of the National Institute of Pharmaceutical Education and Research (Niper), which are situated in different parts of the country and identified as of national importance for pharmacy education in India. Based on previous studies, a standard checklist was prepared to know the contents and services of the websites through an online survey and observation method. To investigate the presence and absence of content that is provided by library websites in the selected websites. The study resulted that selected Nipers 7(100%) provided introductory information about the library/history and listed print/e-journal lists. 6 (86%) of the Nipers websites provided information on databases like Scopus, Drugdex, Rexys, and Scifinder. 5(71%) Nipers listed information about core collection, back/bound volumes and remote access facility. Niper Ahmedabad used CMS WordPress for their development of a library website and it has been an ideal library website among the Niper libraries. None of the Nipers provided feedback, FAQ’s, RRS feeds, or ask a librarian mechanism that collects responses and queries from the patrons. Based on over all findings, Niper Ahmedabad secured the highest rank compared to other nipers with a score of thirty four (34) out of fifty five (55). The study recommends performing such evaluation studies at regular interval will enables institutes to update their websites frequently enough to meet user expectations
Queuing-Inventory Models with MAP Demands and Random Replenishment Opportunities
Combining the study of queuing with inventory is very common and such systems are referred to as queuing-inventory systems in the literature. These systems occur naturally in practice and have been studied extensively in the literature. The inventory systems considered in the literature generally include (s, S)-type. However, in this paper we look at opportunistic-type inventory replenishment in which there is an independent point process that is used to model events that are called opportunistic for replenishing inventory. When an opportunity (to replenish) occurs, a probabilistic rule that depends on the inventory level is used to determine whether to avail it or not. Assuming that the customers arrive according to a Markovian arrival process, the demands for inventory occur in batches of varying size, the demands require random service times that are modeled using a continuous-time phase-type distribution, and the point process for the opportunistic replenishment is a Poisson process, we apply matrix-analytic methods to study two of such models. In one of the models, the customers are lost when at arrivals there is no inventory and in the other model, the customers can enter into the system even if the inventory is zero but the server has to be busy at that moment. However, the customers are lost at arrivals when the server is idle with zero inventory or at service completion epochs that leave the inventory to be zero. Illustrative numerical examples are presented, and some possible future work is highlighted
Oral rehydration salts therapy use among children under five years of age with diarrhea in Ethiopia
Background: Oral rehydration salts (ORS) therapy for diarrheal diseases is considered an effective therapy that can be applied in many resource-poor settings. Nevertheless, it has been consistently underutilized, and as a result, its potential to reduce child mortality has not been fully exploited. In Ethiopia, the use of ORS therapy for children under five has been inadequate. Like any other health behavior, the provision of ORS therapy to children during diarrheal episodes by caregivers is complex and context dependent. Identifying the factors may help promote wider application.Design and methods: We used data from the 2016 Ethiopia Demographic and Health Survey (EDHS-2016). Samples were selected by a two-stage stratified cluster sampling method. We used data on children under five years of age whose mothers (aged 15-49 years) reported that the child had had diarrhea within two weeks before the survey was conducted (n=1221). The dependent variable was whether these children received ORS therapy. The contextual independent factors were socio-demographic variables (mothers’ age, child’s age, child’s sex, child’s place of residence, household wealth, and mother/ husband/partner’s education levels and work status), as well as media exposure and healthcare utilization.Results: The prevalence of ORS therapy use among the children was 30%. Mothers who had made at least four prenatal visits during their last pregnancy were 87% more likely to use ORS therapy for their children than those who had fewer prenatal visits (OR=1.874; CI: 1.140-3.082; p=0.013).Conclusions: Integrating efforts for scaling-up ORS use with prenatal health care services may have an extra benefit of promoting children’s wellbeing and survival
Dry sliding friction and wear behavior of hybrid glass - carbon fiber reinforced PA66/PTFE composites
The tribological response and the frictional effects in dry sliding wear behaviour of hybrid Glass –Carbon composites under the action of sliding load and sliding velocity was studied. The material systems considered for the investigation were PA66/PTFE blend (80/20 wt. %), Blend(PA66/PTFE)/10 wt.% short glass fiber (SGF), Blend (PA66/PTFE)/10 wt.% short carbon fiber (SCF) and Blend (PA66/PTFE)/10 wt.% SGF/10 wt.% SCF (GC).These composites were produced using melt mixing method through extrusion and followed by injection molding. The experimentation was conducted as per ASTM G99 method. The experimentation data revealed that the significant wear resistance was exhibited by Glass-Carbon hybrid composites under the action of all the test parameters. This is attributed to the hybrid effect of fibres which may restrict the early reaching of softening point of polymers thereby preventing melting wear. Further, the formation of uniform and defined transfer polymer substrate on the steel disc surface reduced the frictional effects. Further, Blend/SCF composites were better than Blend/SGF composites. The composites studied were sensitive to applied normal load compared to velocity. The combined matrix and fiber wear were credited to the critical wear volume loss. Fiber misalignment, matrix deformation, melting wear and fiber peeling were some of the failure mechanisms observed in the morphological study of hybrid composites through SEM images
Medical management of ovarian ectopic pregnancy- a case report
Primary ovarian ectopic pregnancy is a rare type of ectopic pregnancy which has an estimated prevalence ranging from 1:7000 to 1:70,000 accounting for almost 3 % of all ectopic cases. A 37-year-old woman was referred to our hospital intermittent vaginal spotting, recurrent abdominal pain that was getting worse, and 3 days of vaginal bleeding with clot passage. Her general condition was good and her vital signs were normal. She felt tenderness in an abdominal examination and had a small amount of vaginal bleeding. Transvaginal ultrasonography showed an ectopic gestational sac, in her right ovary. Our final diagnosis was ectopic ovarian pregnancy and we successfully treated her with methotrexate. After 3 doses of methotrexate administration her beta human chorionic gonadotropin was negative and a sonographic examination was completely normal. Approximately 3% of all ectopic pregnancies are located in the ovaries. Preoperative diagnosis of this extremely rare condition is challenging, because the ectopic pregnancy often resembles cysts of the corpus luteum
What is the potential for biogas digesters to improve soil carbon sequestration in Sub-Saharan Africa? Comparison with other uses of organic residues
Acknowledgments We are very grateful to the UK Department for International Development (DFID) New and Emerging Technologies Research Call for funding this work. PS is a Royal Society-Wolfson Research Merit Award holder.Peer reviewedPostprin
- …