Extended wavelength infrared photodetectors

Extension of the wavelength threshold of an infrared detector beyond λt=hc/Δ is demonstrated, without reducing the minimum energy gap (Δ) of the material. Specifically, a photodetector designed with Δ=0.40  eV, and a corresponding λt=3.1  μm, was shown to have an extended threshold of ∼45  μm at 5.3 K, at zero bias. Under negative and positive applied bias, this range was further extended to ∼60 and ∼68  μm, respectively, with the photoresponse becoming stronger at increased biases, but the spectral threshold remained relatively constant. The observed wavelength extension arises from an offset between the two potential barriers in the device. Without the offset, another detector with Δ=0.30  eV showed a photoresponse with the expected wavelength threshold of ∼4  μm

Analysis of Extended Threshold Wavelength Photoresponse in Nonsymmetrical p-GaAs/AlGaAs Heterostructure Photodetectors

We analyze the extended threshold wavelength photoresponse beyond the standard threshold limit (λt = 1.24/Δ, where Δ is the activation energy) in nonsymmetrical pGaAs/AlGaAs heterostructure photodetectors with a barrier energy offset. We propose that hot-cold hole carrier interactions in the p-GaAs absorber are responsible for the threshold wavelength extension. Experimental results are analyzed by considering a quasi-Fermi distribution of hot holes at a hot hole temperature (TH), which is much higher than the lattice temperature (TL). The experimental photoresponse is fitted using an escape cone model, modified with a quasi-Fermi level (EquasiF). The simulated results are found to be in good agreement with experimental data, justifying the model used

A study of greater sciatic notch as an indicator of sex determination of adult human hip bone

Background: Sex determination from bone is very useful for anatomy, forensic and anthropology personnel. Hip bone is most commonly used bone for sex identification. Aims: Present study was carried out to assess the efficacy of greater sciatic notch to determine sex. Material & Methods: Study sample consisted of 108 adult human hip bones (27 male and female, each of both side) obtained from Anatomy department, P.D.U. Medical College, Rajkot, Gujarat. Present study focused on two indices of greater sciatic notch. Index1 = (maximum breadth of greater sciatic notch/maximum depth of greater sciatic notch)*100 and Index2= (length of posterior segment of maximum breadth of greater sciatic notch /maximum breadth of greater sciatic notch)*100. Results: Index 1 identified correct sex in 51.85% of right male, 44.44% of right female, 44.44% of left male and 48.14% of left female bones. While index 2 identified correct sex in 70.37% of right male , 66.66% of right female, 55.55% of left male and 59.25% of left female bones. Conclusion: This study indicates that these indices are helpful for sex determination in both sexes with index 2 being more sensitive as compared to index 1

Eating well, living well and weight management: A co-produced semi-qualitative study of barriers and facilitators experienced by adults with intellectual disabilities

Adults with intellectual disabilities in England experience health inequalities. They are more likely than their non-disabled peers to be obese and at risk of serious medical conditions such as heart disease, stroke and type 2 diabetes. This semi-qualitative study engaged adults with intellectual disabilities in a co-production process to explore their perceived barriers and facilitators to eating well, living well and weight management. Nineteen participants with intellectual disabilities took part in four focus groups and one wider group discussion. They were supported by eight of their carers or support workers. Several barriers were identified including personal income restrictions, carers’ and support workers’ unmet training needs, a lack of accessible information, inaccessible services and societal barriers such as the widespread advertising of less healthy foodstuffs. A key theme of frustration with barriers emerged from analysis of participants’ responses. Practical solutions suggested by participants included provision of clear and accessible healthy lifestyle information, reasonable adjustments to services, training, ‘buddying’ support systems or schemes and collaborative working to improve policy and practice

Heat pipe based battery thermal management: Evaluating the potential of two novel battery pack integrations

© 2021 The Author(s). Lithium-ion batteries are widely used in high power applications and, with more industries focusing on the electrification of their processes, the need for an effective battery thermal management system is growing. The use of a thermal management system serves multiple purposes such as safeguarding the battery from catastrophic thermal runaway and increasing the lifespan of the battery pack. In the present paper, the thermal management of a sixteen-cell battery module, by two different configurations of a heat pipe based thermal management system, is investigated experimentally. In the first configuration, the module is fixed on top of a single horizontal ‘heat mat’. The second configuration consists of the module sandwiched between two vertical heat mats. The comparison of the cooling performances of these two configurations showed their ability to efficiently absorb the heat generated by the cells and maintain their temperatures close to the ideal operating range. During representative cycles of operation, the maximum cell temperature was kept below 28.5 °C and 24.5 °C for the horizontal and vertical heat mat configurations respectively. The cell temperature uniformity across the module stays in a +/-1 °C range, which will reduce cell voltage imbalance, loss of useable capacity and non-uniform ageing. The maximum temperature difference across the height of the cells was 6 °C for the horizontal configuration and 2 °C for the vertical one. The second part of this paper compares the heat removed in both configurations when loaded with a quasi-steady-state heat generation. The third study uses a faster (6C) charge rate during a representative cycle and shows that the maximum temperature stays below 30 °C and 28 °C for the horizontal and vertical configurations respectively.Innovative UK (Grant no. 3941/133371)

Analysis of factors influencing the ultrasonic fetal weight estimation

Objective: The aim of our study was the evaluation of sonographic fetal weight estimation taking into consideration 9 of the most important factors of influence on the precision of the estimation. Methods: We analyzed 820 singleton pregnancies from 22 to 42 weeks of gestational age. We evaluated 9 different factors that potentially influence the precision of sonographic weight estimation ( time interval between estimation and delivery, experts vs. less experienced investigator, fetal gender, gestational age, fetal weight, maternal BMI, amniotic fluid index, presentation of the fetus, location of the placenta). Finally, we compared the results of the fetal weight estimation of the fetuses with poor scanning conditions to those presenting good scanning conditions. Results: Of the 9 evaluated factors that may influence accuracy of fetal weight estimation, only a short interval between sonographic weight estimation and delivery (0-7 vs. 8-14 days) had a statistically significant impact. Conclusion: Of all known factors of influence, only a time interval of more than 7 days between estimation and delivery had a negative impact on the estimation

Dynamics of HEV viremia, fecal shedding and its relationship with transaminases and antibody response in patients with sporadic acute hepatitis E

<p>Abstract</p> <p>Background</p> <p>There is paucity of data regarding duration of fecal excretion and viremia on sequential samples from individual patients and its correlation with serum transaminases and antibody responses in patients with acute hepatitis E. This prospective study was undertaken at a tertiary care center in Northern India over 15 months. Only those patients of sporadic acute hepatitis E who were in their first week of illness and followed up weekly for liver function tests, IgM anti HEV antibody and HEV RNA in sera and stool were included. HEV RNA was done by RT - nPCR using two pairs of primers from RdRp region of ORF 1 of the HEV genome.</p> <p>Results</p> <p>Over a period of 15 months 60 patients met the inclusion criterion and were enrolled for the final analysis. The mean age of the patients was 29.2 ± 8.92 years, there were 39 males. The positivity of IgM anti HEV was 80% at diagnosis and 18.3% at 7th week, HEV RNA 85% at diagnosis and 6.6% at 7th week and fecal RNA 70% at the time of diagnosis and 20% at 4th week. The maximum duration of viremia detected was 42 days and fecal viral shedding was 28 days after the onset of illness.</p> <p>Conclusion</p> <p>Present study reported HEV RNA positivity in sera after normalization of transaminases. Fecal shedding was not seen beyond normalization of transaminases. However, viremia lasted beyond normalization of transaminases suggesting that liver injury is independent of viral replication.</p

Protective Effects of Walnut Extract Against Amyloid Beta Peptide-Induced Cell Death and Oxidative Stress in PC12 Cells

Amyloid beta-protein (Aβ) is the major component of senile plaques and cerebrovascular amyloid deposits in individuals with Alzheimer’s disease. Aβ is known to increase free radical production in neuronal cells, leading to oxidative stress and cell death. Recently, considerable attention has been focused on dietary antioxidants that are able to scavenge reactive oxygen species (ROS), thereby offering protection against oxidative stress. Walnuts are rich in components that have anti-oxidant and anti-inflammatory properties. The inhibition of in vitro fibrillization of synthetic Aβ, and solubilization of preformed fibrillar Aβ by walnut extract was previously reported. The present study was designed to investigate whether walnut extract can protect against Aβ-induced oxidative damage and cytotoxicity. The effect of walnut extract on Aβ-induced cellular damage, ROS generation and apoptosis in PC12 pheochromocytoma cells was studied. Walnut extract reduced Aβ-mediated cell death assessed by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) reduction, and release of lactate dehydrogenase (membrane damage), DNA damage (apoptosis) and generation of ROS in a concentration-dependent manner. These results suggest that walnut extract can counteract Aβ-induced oxidative stress and associated cell death