427 research outputs found

    Turbulence in journal bearings

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    In this investigation, an experimental study was performed on a journal bearing under laminar and turbulent flow conditions. Using relationships for friction factor developed previously by other investigators a comparison was made with results of this present investigation. Since the flow changes from laminar to turbulent with a change in speed of rotation, curves for friction factor as a function of speed were plotted. Various attempts to make the recording and measuring systems more sensitive were also made and are discussed in this thesis --Abstract, page ii

    Determination and Correlation of Anticardiolipin Antibody with High Sensitivity C- reactive Proteins and its Role in Predicting Short Term Outcome in Patients with Acute Coronary Syndrome

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    Anticardiolipin antibody (aCL) is considered to be an independent risk factor while high sensitivity C reactive protein (hsCRP) is an established marker for coronary artery disease. This study was conducted to determine levels of aCL antibodies and hsCRP, their correlation and role in predicting recurrence of events in patients presenting with Acute Coronary Syndrome (ACS). Sixty patients admitted with Acute Coronary Syndrome were followed up for 7 days or until discharge. Patients were classified into two groups as those having experienced an ischemic event needing intervention within 7 days (Group I) and other having an event free recovery (Group II). aCL antibody and hsCRP levels were estimated and compared in these two groups. Twenty age and sex matched disease free persons served as controls. The levels of aCL were significantly higher in patients with ACS as compared to the controls (p=0.020). However the levels of aCL in Group I (13.39±9.46 GPL-U/ml) and Group II (13.51±9.93 GPL-U/ml) were not significantly different (p =0.838). The mean hsCRP levels were higher in cases with an event (23.30±10.68 mg/dl) than in cases without an event (20.60±11.45mg/dl) though it was not significant statistically (p=0.389). aCL and CRP were not found to be significantly correlated in causing the recurrence of events(p=0.178). Therefore anticardiolipin antibody is an independent risk factor which could be implicated in the pathogenesis of ACS. However it is not significantly associated with recurrence of short-term events in patients with ACS. Also, aCL antibody does not have significant correlation with hSCRP in causing recurrence of events in the patients of acute coronary syndrome

    Study on flow properties of rotor grade steel

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    Compression tests were performed on Gleeble 3800 Thermo-Mechanical Simulator to study the flow properties of rotor grade steel 28CrMoNiV59. Compression specimens were deformed at a constant strain rate of 10-3 s-1. The temperature range during tests was between room temperature and 1000°C with an interval of 100°C. When the normalized flow stress was plotted as a function of temperature, it exhibited three different regions. In regions I and III flow stress decreases with increase in temperature but the same increases with temperature in region II. Microstructural changes and work hardening behaviour have been studied for the deformed specimen. Furthermore, TEM analysis was also done for the samples of these three different regions (I, II & III). Strain hardening rate as a function of the normalized flow stresses decreases at larger strain and become negligible at higher temperature

    Quantification of cinnarizine and dimenhydrinate in tablet dosage form by simultaneous equation spectrophotometric method

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    Simple, accurate, precise, reproducible, requiring no prior separation and economical procedures for simultaneous estimation of Cinnarizine(CNZ) and Dimenhydrinate(DMH) in tablet dosage form have been developed. Method employs formation and solving of simultaneous equation using 250 nm and 277 nm as two analytical wavelengths for both drugs in methanol. CNZ and DMH at their respective ? max 250 nm and 277 nm shows linearity in a concentration range of 2-12 ?g /ml and 10-35 ?g /ml. Recovery studies for CNZ 98.9-100.75% and 96.16-100.69% for DMH in case of simultaneous equation method confirming the accuracy of the proposed method. The proposed method is recommended for routine analysis since it is rapid, simple, accurate and also sensitive and specific

    Improvement of TCAD Augmented Machine Learning Using Autoencoder for Semiconductor Variation Identification and Inverse Design

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    A machine learning (ML) model by combing two autoencoders and one linear regression model is proposed to avoid overfitting and to improve the accuracy of Technology Computer-Aided Design (TCAD)-augmented ML for semiconductor structural variation identification and inverse design, without using domain expertise. TCAD-augmented ML utilizes TCAD simulations to generate sufficient data for ML model development when experimental data are inadequate. The ML model can then be used to identify semiconductor structural variation for given experimental electrical measurements. In this study, the variation of layer thicknesses in the p-i-n diode is used as a demonstration. An ML model is developed to predict the diode layer thicknesses based on a given Current-Voltage (IV) curve. Although the variations of interest can be incorporated easily in TCAD simulations to generate ML training data, the TCAD-augmented ML model generally is overfitted and cannot predict the variations in experiment well due to hidden variables which also alters the IV curves. We show that by using an autoencoder, this problem can be solved. To verify the effectiveness, another set of TCAD simulation data is generated with hidden variables (dopant concentration variation) to emulate experimental data. Testing on the second set of data shows that the proposed model can avoid overfitting and has up to 15 times improvement in accuracy in thickness prediction. Moreover, this model is used successfully to perform inverse design and can capture an underlying physics that cannot be described by a simple physical parameter

    Extraocular retinoblastoma in Indian children:clinical, imaging and histopathological features

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    AIM: To study eyes with extraocular dissemination (EORB), with the following aims:first to establish the mean lag period and to understand various reasons for delayed presentation, second to study their imaging profiles and third to analyze histopathological features of eyes enucleated after neoadjuvant chemotherapy.METHODS: Prospective study of clinical and imaging features of EORBs (stage Ⅲ and Ⅳ International Retinoblastoma Staging System) presenting to a tertiary eye care centre. Histopathological features of eyes enucleated after receiving neoadjuvant chemotherapy were analyzed. A pictorial illustration of the varied imaging profile of EORB was also presented.RESULTS: Over a period of one year, 97 eyes were diagnosed with retinoblastoma; 32 children (36 eyes) (37.1%) had EORB. Mean age 3.6±1.9 years, 71.9% males, 71.9% unilateral, 3.1% with positive family history and 40.6% with metastasis. On imaging, there was extrascleral involvement in 22.2%, involvement of orbital part of optic nerve in 33.3%, involvement of central nervous system in 27.8% and orbital wall involvement in 2.9% eyes. On histopathological analysis of eyes enucleated after neoadjuvant chemotherapy, 25.0% had no residual viable tumour tissue and rest all tumours were poorly differentiated.CONCLUSION:There are very few human malignancies where definitive treatment is started without any confirmed histopathological diagnosis and imaging plays an important role in diagnosis and appropriate staging of the disease. Chemotherapy has a variable effect on EORB, 75.0% of eyes with EORB had residual viable tumour tissue when enucleated after receiving neoadjuvant chemotherapy

    Physics Potential of the ICAL detector at the India-based Neutrino Observatory (INO)

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    The upcoming 50 kt magnetized iron calorimeter (ICAL) detector at the India-based Neutrino Observatory (INO) is designed to study the atmospheric neutrinos and antineutrinos separately over a wide range of energies and path lengths. The primary focus of this experiment is to explore the Earth matter effects by observing the energy and zenith angle dependence of the atmospheric neutrinos in the multi-GeV range. This study will be crucial to address some of the outstanding issues in neutrino oscillation physics, including the fundamental issue of neutrino mass hierarchy. In this document, we present the physics potential of the detector as obtained from realistic detector simulations. We describe the simulation framework, the neutrino interactions in the detector, and the expected response of the detector to particles traversing it. The ICAL detector can determine the energy and direction of the muons to a high precision, and in addition, its sensitivity to multi-GeV hadrons increases its physics reach substantially. Its charge identification capability, and hence its ability to distinguish neutrinos from antineutrinos, makes it an efficient detector for determining the neutrino mass hierarchy. In this report, we outline the analyses carried out for the determination of neutrino mass hierarchy and precision measurements of atmospheric neutrino mixing parameters at ICAL, and give the expected physics reach of the detector with 10 years of runtime. We also explore the potential of ICAL for probing new physics scenarios like CPT violation and the presence of magnetic monopoles.Comment: 139 pages, Physics White Paper of the ICAL (INO) Collaboration, Contents identical with the version published in Pramana - J. Physic

    Survey and evaluation of hypertension machine learning research

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    Background: Machine learning (ML) is pervasive in all fields of research, from automating tasks to complex decision‐making. However, applications in different specialities are variable and generally limited. Like other conditions, the number of studies employing ML in hypertension research is growing rapidly. In this study, we aimed to survey hypertension research using ML, evaluate the reporting quality, and identify barriers to ML's potential to transform hypertension care. Methods and Results: The Harmonious Understanding of Machine Learning Analytics Network survey questionnaire was applied to 63 hypertension‐related ML research articles published between January 2019 and September 2021. The most common research topics were blood pressure prediction (38%), hypertension (22%), cardiovascular outcomes (6%), blood pressure variability (5%), treatment response (5%), and real‐time blood pressure estimation (5%). The reporting quality of the articles was variable. Only 46% of articles described the study population or derivation cohort. Most articles (81%) reported at least 1 performance measure, but only 40% presented any measures of calibration. Compliance with ethics, patient privacy, and data security regulations were mentioned in 30 (48%) of the articles. Only 14% used geographically or temporally distinct validation data sets. Algorithmic bias was not addressed in any of the articles, with only 6 of them acknowledging risk of bias. Conclusions: Recent ML research on hypertension is limited to exploratory research and has significant shortcomings in reporting quality, model validation, and algorithmic bias. Our analysis identifies areas for improvement that will help pave the way for the realization of the potential of ML in hypertension and facilitate its adoption

    Dosage Effects of Cohesin Regulatory Factor PDS5 on Mammalian Development: Implications for Cohesinopathies

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    Cornelia de Lange syndrome (CdLS), a disorder caused by mutations in cohesion proteins, is characterized by multisystem developmental abnormalities. PDS5, a cohesion protein, is important for proper chromosome segregation in lower organisms and has two homologues in vertebrates (PDS5A and PDS5B). Pds5B mutant mice have developmental abnormalities resembling CdLS; however the role of Pds5A in mammals and the association of PDS5 proteins with CdLS are unknown. To delineate genetic interactions between Pds5A and Pds5B and explore mechanisms underlying phenotypic variability, we generated Pds5A-deficient mice. Curiously, these mice exhibit multiple abnormalities that were previously observed in Pds5B-deficient mice, including cleft palate, skeletal patterning defects, growth retardation, congenital heart defects and delayed migration of enteric neuron precursors. They also frequently display renal agenesis, an abnormality not observed in Pds5B−/− mice. While Pds5A−/− and Pds5B−/− mice die at birth, embryos harboring 3 mutant Pds5 alleles die between E11.5 and E12.5 most likely of heart failure, indicating that total Pds5 gene dosage is critical for normal development. In addition, characterization of these compound homozygous-heterozygous mice revealed a severe abnormality in lens formation that does not occur in either Pds5A−/− or Pds5B−/− mice. We further identified a functional missense mutation (R1292Q) in the PDS5B DNA-binding domain in a familial case of CdLS, in which affected individuals also develop megacolon. This study shows that PDS5A and PDS5B functions other than those involving chromosomal dynamics are important for normal development, highlights the sensitivity of key developmental processes on PDS5 signaling, and provides mechanistic insights into how PDS5 mutations may lead to CdLS

    Severe Asthma Standard-of-Care Background Medication Reduction With Benralizumab: ANDHI in Practice Substudy

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    Background: The phase IIIb, randomized, parallel-group, placebo-controlled ANDHI double-blind (DB) study extended understanding of the efficacy of benralizumab for patients with severe eosinophilic asthma. Patients from ANDHI DB could join the 56-week ANDHI in Practice (IP) single-arm, open-label extension substudy. Objective: Assess potential for standard-of-care background medication reductions while maintaining asthma control with benralizumab. Methods: Following ANDHI DB completion, eligible adults were enrolled in ANDHI IP. After an 8-week run-in with benralizumab, there were 5 visits to potentially reduce background asthma medications for patients achieving and maintaining protocol-defined asthma control with benralizumab. Main outcome measures for non-oral corticosteroid (OCS)-dependent patients were the proportions with at least 1 background medication reduction (ie, lower inhaled corticosteroid dose, background medication discontinuation) and the number of adapted Global Initiative for Asthma (GINA) step reductions at end of treatment (EOT). Main outcomes for OCS-dependent patients were reductions in daily OCS dosage and proportion achieving OCS dosage of 5 mg or lower at EOT. Results: For non-OCS-dependent patients, 53.3% (n = 208 of 390) achieved at least 1 background medication reduction, increasing to 72.6% (n = 130 of 179) for patients who maintained protocol-defined asthma control at EOT. A total of 41.9% (n = 163 of 389) achieved at least 1 adapted GINA step reduction, increasing to 61.8% (n = 110 of 178) for patients with protocol-defined EOT asthma control. At ANDHI IP baseline, OCS dosages were 5 mg or lower for 40.4% (n = 40 of 99) of OCS-dependent patients. Of OCS-dependent patients, 50.5% (n = 50 of 99) eliminated OCS and 74.7% (n = 74 of 99) achieved dosages of 5 mg or lower at EOT. Conclusions: These findings demonstrate benralizumab's ability to improve asthma control, thereby allowing background medication reduction
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