The overall electrical efficiency of the photovoltaic (PV) module can be increased by reducing the temperature of the PV module by withdrawing the thermal energy associated with the PV module. In ...this communication an attempt has been made to develop analytical expression for electrical efficiency of PV module with and without flow as a function of climatic and design parameters. The four different configurations of PV modules are considered for the present study which are defined as; case A (Glass to glass PV module with duct), case B (Glass to glass PV module without duct), case C (Glass to tedlar PV module with duct), case D (Glass to tedlar PV module without duct). Further, experiments were carried out for all configurations under composite climate of New Delhi.
It is found that the glass to glass PV modules with duct gives higher electrical efficiency as well as the higher outlet air temperature amongst the all four cases. The annual effect on electrical efficiency of glass to glass type PV module with and without duct is also evaluated. The annual average efficiency of glass to glass type PV module with and without duct is 10.41% and 9.75%, respectively.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Application of the frequency domain acoustic wave equation on data acquired from ultrasound tomography scans is shown to yield high resolution sound speed images on the order of the wavelength of the ...highest reconstructed frequency. Using a signal bandwidth of 0.4-1 MHz and an average sound speed of 1500 m s−1, the resolution is approximately 1.5 mm. The quantitative sound speed values and morphology provided by these images have the potential to inform diagnosis and classification of breast disease. In this study, we present the formalism, practical application, and in vivo results of waveform tomography applied to breast data gathered by two different ultrasound tomography scanners that utilize ring transducers. The formalism includes a review of frequency domain modeling of the wave equation using finite difference operators as well as a review of the gradient descent method for the iterative reconstruction scheme. It is shown that the practical application of waveform tomography requires an accurate starting model, careful data processing, and a method to gradually incorporate higher frequency information into the sound speed reconstruction. Following these steps resulted in high resolution quantitative sound speed images of the breast. These images show marked improvement relative to commonly used ray tomography reconstruction methods. The robustness of the method is demonstrated by obtaining similar results from two different ultrasound tomography devices. We also compare our method to MRI to demonstrate concordant findings. The clinical data used in this work was obtained from a HIPAA compliant clinical study (IRB 040912M1F).
In this communication, an analytical expression for the water temperature of an integrated photovoltaic thermal solar (IPVTS) water heater under constant flow rate hot water withdrawal has been ...obtained. Analysis is based on basic energy balance for hybrid flat plate collector and storage tank, respectively, in the terms of design and climatic parameters. Further, an analysis has also been extended for hot water withdrawal at constant collection temperature. Numerical computations have been carried out for the design and climatic parameters of the system used by Huang et al. Huang BJ, Lin TH, Hung WC, Sun FS. Performance evaluation of solar photovoltaic/thermal systems. Sol Energy 2001; 70(5): 443–8. It is observed that the daily overall thermal efficiency of IPVTS system increases with increase constant flow rate and decrease with increase of constant collection temperature. The exergy analysis of IPVTS system has also been carried out. It is further to be noted that the overall exergy and thermal efficiency of an integrated photovoltaic thermal solar system (IPVTS) is maximum at the hot water withdrawal flow rate of 0.006
kg/s. The hourly net electrical power available from the system has also been evaluated.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Let
be a noncommutative prime ring of characteristic not
, let
be the right Martindale quotient ring of
, and let
be the extended centroid of
. We study the relationship between the structure of ...prime rings and the behavior of generalized skew derivations on multilinear polynomials. More specifically, we investigate the central-valued identity involving a pair of generalized skew derivations on multilinear polynomials in
; i.e.,
for all
, where
is a noncentral polynomial over
, while
and
are generalized skew derivations of
associated with the same automorphism
.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Objectives/Hypothesis
To assess the results of treating idiopathic subglottic stenosis (ISS), determine predictors of treatment success and outcome, and better define roles and limitations of ...endoscopic and open surgery.
Study Design
Prospective observational study.
Methods
Fifty‐four consecutive patients were treated between 2004 and 2012. Patient, stenosis and treatment details, complications, open surgery rates, and outcomes were recorded. Regression analyses were used to identify predictors of endoscopic treatment success; treatment frequency; and functional outcomes in airway, dyspnea, voice, and swallowing domains.
Results
All patients were female and mean age at diagnosis was 48 ± 12 years. Symptoms‐to‐diagnosis latency was 21 ± 20 months. There were 10 concomitant glottic and subglottic stenoses. Most lesions were Myer‐Cotton grade 3 (48%). Overall, 78% of patients were managed endoscopically. Treatment included intralesional corticosteroids, laser surgery, balloon dilation, and temporary silastic stenting in selected cases. Annual intervention rate was 1.07 ± 0.79. Mean follow‐up was 45 months. Factors associated with intervention frequency were stenosis location and severity. Twelve patients underwent anteroposterior laryngotracheal reconstruction with biological inhibition. This resulted in disease remission in all patients with subglottic stenosis, and in most patients with concomitant glottic and subglottic stenosis. Patients with total laryngotracheal stenosis required ongoing treatment for glottic disease. All patients maintained prosthesis‐free airways, but in one patient this required a laryngectomy. Most patients achieved good functional outcomes. Stenosis location was the only independent predictor of dyspnea and voice outcomes.
Conclusions
ISS can be effectively treated with endoscopic surgery or a bespoke open reconstructive procedure that does not compromise on female voice quality.
Level of Evidence
4. Laryngoscope, 123:2474–2484, 2013
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Background. Unlike other respiratory infections, tuberculosis diagnoses increase in summer. We performed an ecological analysis of this paradoxical seasonality in a Peruvian shantytown over 4 years. ...Methods. Tuberculosis symptom-onset and diagnosis dates were recorded for 852 patients. Their tuberculosisexposed cohabitants were tested for tuberculosis infection with the tuberculin skin test (n = 1389) and QuantiFERON assay (n = 576) and vitamin D concentrations (n = 195) quantified from randomly selected cohabitants. Crowding was calculated for all tuberculosis-affected households and daily sunlight records obtained. Results. Fifty-seven percent of vitamin D measurements revealed deficiency (<50 nmol/L). Risk of deficiency was increased 2.0-fold by female sex (P < .001) and 1.4-fold by winter (P < .05). During the weeks following peak crowding and trough sunlight, there was a midwinter peak in vitamin D deficiency (P < .02). Peak vitamin D deficiency was followed 6 weeks later by a late-winter peak in tuberculin skin test positivity and 12 weeks after that by an early-summer peak in QuantiFERON positivity (both P < .04). Twelve weeks after peak QuantiFERON positivity, there was a midsummer peak in tuberculosis symptom onset (P < .05) followed after 3 weeks by a late-summer peak in tuberculosis diagnoses (P < .001). Conclusions. The intervals from midwinter peak crowding and trough sunlight to sequential peaks in vitamin D deficiency, tuberculosis infection, symptom onset, and diagnosis may explain the enigmatic late-summer peak in tuberculosis.
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BFBNIB, NMLJ, NUK, PNG, SAZU, UL, UM, UPUK
In the popular news media, public health officials routinely emphasize the health risks of obesity and portray weight as under personal control. These messages may increase support for policies ...designed to reduce rates of obesity, but can also increase antifat stigma. Less often, the media cover 'Health at Every Size' or 'Fat Rights' perspectives that may have the opposite effects. We investigated how exposure to different 'fat frames' shifts attitudes about weight and support for obesity policies.
Across four experiments (n=2187), people read constructed news articles framing fatness as negative (unhealthy, controllable, acceptable to stigmatize) or positive (healthy, uncontrollable, unacceptable to stigmatize).
Compared with people who read fat-positive frames, people who read fat-negative frames expressed more: belief in the health risks of being fat (d=0.95-1.22), belief weight is controllable (d=0.38-0.55), support for charging obese people more for health insurance (d=0.26-0.77), antifat prejudice (in three out of four experiments, d=0.28-0.39), willingness to discriminate against fat people (d=0.39-0.71) and less willingness to celebrate body size diversity (d=0.37-0.64). They were also less willing to say that women at the lower end of the obese range could be healthy at their weights. Effects on support for public policies, however, were generally small and/or nonsignificant. Compared with a control condition, exposure to fat-positive frames generally shifted attitudes more than fat-negative frames. In experiment 4, adding a message about the unacceptability of weight-based discrimination to unhealthy/controllable news articles only reduced antifat stigma on one of three measures compared with articles adding a discrimination-acceptable message.
Exposure to different news frames of fat can shift beliefs about weight-related health risks and weight-based stigma. Shifting policy attitudes, however, is more challenging.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Abstract Background Psychiatry lags other fields in development of diagnostic tests. Methods A literature review and meta-analysis was conducted to ascertain if polysomnographic abnormalities (REM ...density, REM latency, sleep efficiency, slow wave sleep, stage 1 and stage 2 sleep) warrant additional effort to develop them into a clinical diagnostic test for major depressive disorder (MDD). The 31 publications meeting inclusion criteria were then classified into one of three progressive steps using guidelines for evaluating the clinical usefulness of a diagnostic test. Results Most of the abnormalities found in MDD patients, when compared to healthy controls, occurred in the expected direction with moderate effect sizes but with substantial publication bias and heterogeneity. Eleven studies compared abnormalities in MDD to other psychiatric disorders (step 2a), and four studies provided data on the sensitivity or specificity of the findings in differentiating among the psychiatric disorders that frequently appear on the same differential diagnostic list as MDD (step 2b). No multicenter trial has been conducted prospectively to test the clinical utility of the diagnostic test (step 3). Limitations Only published articles in the English language were used. Conclusions Sleep studies for the detection of MDD appear replicable with a moderate effect size. However, additional step 1 studies are needed to define the sensitivity and specificity. The heterogeneity of sleep recording, scoring techniques, and MDD must also be addressed.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
In this paper, energy metrics (energy pay back time, electricity production factor and life cycle conversion efficiency) of hybrid photovoltaic (PV) modules have been analyzed and presented for the ...composite climate of New Delhi, India. For this purpose, it is necessary to calculate (1) the energy consumption in making different components of the PV modules and (2) the annual energy (electrical and thermal) available from the hybrid-PV modules. A set of mathematical relations have been reformulated for computation of the energy metrics. The manufacturing energy, material production energy, energy use and distribution energy of the system have been taken into account, to determine the embodied energy for the hybrid-PV modules. The embodied energy and annual energy outputs have been used for evaluation of the energy metrics. For hybrid PV module, it has been observed that the EPBT gets significantly reduced by taking into account the increase in annual energy availability of the thermal energy in addition to the electrical energy. The values of EPF and LCCE of hybrid PV module become higher as expected.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
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