98 research outputs found

    Ultra-Low Temperature Coefficient of Capacitance (Tcc) of the SrSnO

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    The perovskite-structured SrSnO3 possessing steady capacitance over the temperature range between 27°C and 300°C in a frequency domain spanning nearly four decades has been evaluated. The samples investigated in this study were synthesized by using solid-state reaction (SSR) and self-heat-sustained (SHS) techniques. These samples were sintered at a temperature (T ) ranging between 1200°C and 1600°C with a soak-time (t) ranging between 2 h and 60 h. The ac immittance (impedance or admittance) measurements were conducted on these sintered bodies in the frequency range 5Hz to 13 MHz. These ac electrical data were found to exhibit relaxation in more than one complex plane formalisms in a simultaneous manner. The magnitude of the terminal capacitance was found to be in a narrow window of 3 pF to 6 pF possessing very weak temperature dependence. Further analysis also revealed that this material system possessed low dielectric constant and ultra-low temperature coefficient of capacitance (TCC) or dielectric constant (TCK). The electrical behavior of these sintered bodies has been systematically correlated with the evolved microstructures. Plausible equivalent circuit elements were extracted using the lumped parameter/complex plane analysis (LP/CPA) and evaluated at various situations

    Awareness of droplet and airborne isolation precautions among dental health professionals during the outbreak of corona virus infection in Riyadh city, Saudi Arabia

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    Background: This study aimed to determine knowledge, attitude and practice of airborne and droplet isolation precautions among Dental Health Professionals (DHPs) (dental students, interns, practitioners and auxiliaries) during the outbreak of MERS (Middle East Respiratory Syndrome), corona virus infection in Riyadh city, Saudi Arabia. Material and Methods: A cross-sectional survey was conducted among 406 dental health professionals (DHPs) working in selected dental facilities in Riyadh city, Saudi Arabia during the outbreak of MERS (April-June 2013). A structured, close-ended, self-administered questionnaire explored the knowledge, attitude, and practice towards droplet and isolation precautions. Collected data was subjected to descriptive statistics to express demographic information, mean knowledge score, mean attitude score and practice score of DHPs. Inferential statistics (MannWhitney U test and Kruskal Wallis tests, p < 0.05) were used to examine differences between study variables. Spearmanâ s rho correlation was used to identify the association between the knowledge-attitude, knowledge-practice, and attitude-practice. Results: A response rate of rate of 90.22% (406 out of 452) was obtained. The mean scores of knowledge, attitude and practice were 10.61 ± 1.19, 50.54 ± 7.53 and 8.50 ± 2.14 respectively. Spearmanâ s correlation test revealed a significant linear positive correlation between knowledge and attitude (r-0.501, P- 0.01), knowledge and practice (r-0.185, P-0.01) and attitude and practice (r-0.351, P- 0.01) of DHPs about airborne isolation precautions. Conclusions: Dental health professionals considered in the present study showed good knowledge, positive attitude and good practice towards droplet and airborne isolation precautions during outbreak of MERS

    Study of the Effect of Berry Paper Mulberry on Optical Properties of Poly Methyl Methacrylate

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    In this work, study the optical properties of composites consisting of poly Methyl Methacrylate and Berry Paper Mulberry. The samples of composites were prepared using casting method .The Berry Paper Mulberry (BPM) was added by different concentrations are (0, 2, 4 and 6)wt.%. The optical properties of composites have been studied in the wavelength range (200-800)nm. The absorption coefficient ,energy gap, refractive index, extinction coefficient and dielectric constants have been determined. The results show that the optical constants change with increase of BPM concentrations

    Discovering potential blood-based cytokine biomarkers for Alzheimer’s disease using Firth Logistic Regression

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    Background: Alzheimer’s disease (AD) is a neurodegenerative disorder where patients suffer from memory loss, cognitive impairment and progressive disability. Individual blood biomarkers have not been successful in defining the disease pathology, progression and diagnosis of AD. There is a need to identify multiplex panels of blood biomarkers for early diagnosis of AD with high sensitivity and specificity. This study focused on identification of cytokine biomarkers. The maximum likelihood estimates of the ordinary logistic regression model cannot be obtained when there is complete separation and the alternative is Firth logistic regression which uses a penalised Maximum Likelihood in parameter estimation.&nbsp; Methods: This paper reports a Firth logistic regression application in finding potential blood-based cytokine biomarkers for Alzheimer’s disease in a matched case control study. We used a principle component analysis to discriminate the correlated, completely separated covariates.&nbsp; Results: The Firth logistic regression results showed that nine individual biomarkers IL-1β, IL-6, IL-12, IFN-γ, IL-10, IL-13, IP-10, MCP-1 and MIP-1α had a significant relationshipwith elevated risk for AD as compared to the healthy control (HC). Principal component analysis with varimax rotation for the nine biomarkers revealed four factors (total variance explained=85.5%). The main principal component biomarkers were IL-1β, IL-6, IL-13 and MCP-1 (total variance explained=62.3%). Firth’s logistic regression model with the first principal component had accuracy of 78.2% with sensitivity and specificity of 71.8% and 75% respectively.&nbsp; Conclusion: Firth’s logistic regression is a useful technique in identification of significant biomarkers when there is an issue of data separation.&nbsp

    Electron Momentum Density in Nickel (Ni)

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    In this paper, Compton profile of (Ni) was Calculated by employing both the renormalized-free atom(RFA) model and free electron(FE) model setting several configurations in subset (3d-4s). The results were compared with recent data ,It shows that the RFA calculation in(3d8.8-4s1.2) gives a better agreement with experiment.The calculated data used for the first time also to compute the cohesive energy of Nickle and compared it with available data. The Band structure and Density of state of Nickel crystals(DFT-LDA) also calculated by using code Quantum wise.Keywords: Compton profile,Electron momentum density, Cohesive energy, Band structure, Density of state

    Potential materials for food packaging from nanoclay/natural fibres filled hybrid composites

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    The increasing demand for new food packaging materials which satisfy people requirements provided thrust for advancement of nano-materials science. Inherent permeability of polymeric materials to gases and vapours; and poor barrier and mechanical properties of biopolymers have boosted interest in developing new strategies to improve these properties. Research and development in polymeric materials coupled with appropriate filler, matrix-filler interaction and new formulation strategies to develop composites have potential applications in food packaging. Advancement in food packaging materials expected to grow with the advent of cheap, renewable and sustainable materials with enhanced barrier and mechanical properties. Nanoparticles have proportionally larger surface area and significant aspect ratio than their micro-scale counterparts, which promotes the development of mechanical and barrier properties. Nanocomposites are attracting considerable interest in food packaging because of these fascinating features. On the other hand, natural fibres are susceptible to microorganisms and their biodegradability is one of the most promising aspects of their incorporation in polymeric materials. Present review article explain about different categories of nanoclay and natural fibre based composite with particular regard to its applications as packaging materials and also gives an overview of the most recent advances and emerging new aspects of nanotechnology for development of hybrid composites for environmentally compatible food packaging materials

    Genetic study in congenital heart defects

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    Background: Congenital heart diseases (CHD) are relatively common with a prevalence ranging from 3.7 to 17.5 per 1000 live births. Little is known about genetic link with respect to congenital heart disease. Iroquoise (Irx) homeobox genes have been widely studied and their expression in both developing and adult heart. Author tried to study the role of irx4 and irx5 genes in structural congenital heart disease, keeping the focus on study reported by Cheng Z et al.Methods: Author studied reported mutation site sequences in 25 various congenital heart disease patients and control healthy relatives of patients. It is a unique study and there has not been such a study reported in literature till date. Besides comparison with healthy related controls, author took cardiac tissue biopsy in patients while doing corrective cardiac surgery. However, blood samples were taken from controls due to ease of feasibility.Results: Although, there were no sequence variations in the studied exon regions, but author got a base pair sequence change at 6 bp intron region, which is near the exon splice site in irx4 gene. Besides two ASD patient’s male children (one child each) had ASD prompting us to believe some role of sex linkage. However later needs pedigree analysis and sex chromosome studies for further analysis.Conclusions: Gene sequence in the Kashmiri population is unique. There is possibility of role of irx genes in CHD. ASD might have sex linkage in some

    Early results after transatrial repair of RVOT obstruction including teratology of fallot

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    Background: Right ventricular (RV) dysfunction is a significant cause of morbidity and mortality after surgical correction of RVOT obstruction including tetralogy of Fallot (TOF). Transatrial repair avoids a ventriculotomy (in contrast to the transventricular approach) emphasizing maximal preservation of RV structure and function. We have adopted this technique as less traumatic for the right ventricle. This study evaluates the early surgical results of our approach.Methods: Between January 2005 to January 2014, 77 consecutive patients with RVOT obstruction were referred to our unit for surgical therapy. Of these, 14 were unsuitable for repair and underwent aortopulmonary shunting. In the remaining 63 patients (mean age of 2.67±0.38 years), complete transatrial/transpulmonary repair was performed. Previously placed shunts (four patients) were taken down. In all cases, subpulmonary resection and ventricular septal defect (VSD) closure were accomplished transatrially. In 51 patients, the main pulmonary artery was augmented with an autologous pericardial patch.Results: There were 7 (9%) deaths in this series. No patient required permanent pacemaker. Median ICU and hospital stay were 91 hours and 14 days, respectively. At median follow up of 54 (mean 51±12) months, all patients are asymptomatic, with no significant residual lesion.Conclusions: Transatrial/transpulmonary repair of TOF is associated with remarkably low morbidity and mortality in our early experience

    The application of modified equipment in retention of motor task performance amongst children of low and high working memory capacity

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    The ability of children to learn and retain motor-related tasks could ease the pathway of mastering sport-specific skills that are non-trivial in spurring children’s athletic development. Modification of equipment may facilitate the acquisition of complex motor tasks with respect to children’s specific characteristics. The influence of modified equipment in retention ability of motor task amongst children with low and high working memory capacities is investigated in this study. Forty children aged 9–10 years were recruited and the Wechsler Intelligence Scale for Children was used to determine the working memory capacity of the children. High and low working memory (HWM), (LWM) were identified and allotted into 4 different groups of 10 children each Viz. (A) HWM with standard mini basketball equipment, (B) LWM with standard mini basketball equipment, (C) HWM with modified mini basketball equipment and (D) LWM with modified mini basketball equipment. Basketball throw from the free-throw line in pre and post-tests were used as the acquisition and retention tasks ability respectively. There was a significant main effect of memory and equipment towards children’s retention ability. A significant difference was also observed across both HMC and LWM when subjected to the use of modified equipment (F, 1, 24.025) = 23.958, p 0.05. The usage of modified basketball equipment could enhance mastery of motor tasks in children irrespective of their memory capacity

    Diagnosis of hearing deficiency using EEG based AEP signals: CWT and improved-VGG16 pipeline

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    Hearing deficiency is the world’s most common sensation of impairment and impedes human communication and learning. Early and precise hearing diagnosis using electroencephalogram (EEG) is referred to as the optimum strategy to deal with this issue. Among a wide range of EEG control signals, the most relevant modality for hearing loss diagnosis is auditory evoked potential (AEP) which is produced in the brain’s cortex area through an auditory stimulus. This study aims to develop a robust intelligent auditory sensation system utilizing a pre-train deep learning framework by analyzing and evaluating the functional reliability of the hearing based on the AEP response. First, the raw AEP data is transformed into time-frequency images through the wavelet transformation. Then, lower-level functionality is eliminated using a pre-trained network. Here, an improved-VGG16 architecture has been designed based on removing some convolutional layers and adding new layers in the fully connected block. Subsequently, the higher levels of the neural network architecture are fine-tuned using the labelled time-frequency images. Finally, the proposed method’s performance has been validated by a reputed publicly available AEP dataset, recorded from sixteen subjects when they have heard specific auditory stimuli in the left or right ear. The proposed method outperforms the state-of-art studies by improving the classification accuracy to 96.87% (from 57.375%), which indicates that the proposed improved-VGG16 architecture can significantly deal with AEP response in early hearing loss diagnosis
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