Novel electrolytes and system designs for thermo-electrochemical cells

Low-grade waste heat is ubiquitous and a byproduct of all energy conversion mechanisms. Thermo-electrochemical cells (thermocells) directly convert temperature difference to electromotive force with no moving parts. It is an inexpensive technology to harvest waste heat. However, low power conversion efficiency due to ohmic, interfacial charge transfer and mass transfer resistances has limited its use in commercial applications. This work explores improving electrochemical properties of the standard electrolyte and implementation of thermocells in applications providing liquid cooling. In the initial part of this dissertation, poly (3,4-ethylenedioxythiophene)− poly (styrenesulfonate) was used to form a composite having percolated networks of dispersed carbon nanotubes. The composite was dispersed in the standard electrolyte of thermocells aqueous potassium ferri/ferrocyanide and the mixture was characterized using electrochemical impedance spectroscopy. Analysis of the impedance spectra showed a 10 % increase in ohmic conductivity and about a 5-fold decrease in interfacial charge transfer resistance in the composite electrolyte, which is caused by addition of the charge carriers, interfacial polarization and improved contact at the electrode/electrolyte interface. The enhancement of properties in the composite electrolyte increases the power of a thermo-electrochemical cell by about 30 %. In addition, thermal characterization using transient plane source technique showed that the thermal conductivity decreased by about 5 % for the new composite electrolyte, leading to ZT enhancement by about 15 %. Thermocells low efficiencies, restrict there use as a standalone energy harvesting device. To this end, flow thermo-electrochemical cell (fTEC) has been invented, fabricated and implemented specifically for data centers and it can be extended to wherever liquid cooling heat sinks are employed. The current sole purpose of heat sinks is to provide cooling, fTEC enable supplementing the existing purpose with energy harvesting and temperature monitoring for entire liquid flow line. Initial unoptimized design in term of electrode material and configuration produced power density of 0.05 W/m2 and provided heat transfer coefficient of 450 W/m2 K. Carbon nanotube buckypaper electrodes are used to improve the performance of fTEC. The use of carbon nanotube buckypaper electrode provided a larger surface area and faster kinetics for redox reaction. Optimization of the electrode material and configuration, improved the power density of fTEC to 0.36 W/m2. The original contribution of this work are three fold. Firstly, composite of poly (3,4-ethylenedioxythiophene)− poly (styrenesulfonate) and carbon nanotube was developed that improved the interfacial charge transfer resistance, ohmic conductivity and thermal conductivity of the benchmark electrolyte used for thermocells. Secondly, thermocell having flowing electrolyte was identified, fabricated and implemented. The fTEC provides cooling, energy harvesting and temperature monitoring for liquid cooling applications. Thirdly, the design of the fTEC is improved by taking advantage of the higher temperature available and using electrodes providing larger surface area and faster charge transfer kinetics.Ph.D

Implications of Critical Literacy for Language Classroom

The present study is aimed at examining how critical literacy helps the students in using language efficiently and exploring new ways of reading any text. The study focuses on gauging the place of critical literacy at graduate level and also checks the awareness of students and teachers to this productive way of using language. This study also tries to find out about the gap that exists between the objectives of critical literacy in Pakistan and our present curriculum. For this purpose both qualitative and quantitative methods of data collection and analysis were used. Finally it brings the results that in Pakistan curriculum dominantly focuses the structural level of language and does not give students sociopolitical insight. The learning of students is more bookish and does not enable the learners to employ their language skill in understanding the ways of the world. Keywords: Critical Literacy, Critical thinking, Curriculum, Civic education, Teaching methodolog

Comparison of Mean Glasgow Outcome Score in Patients with Traumatic Brain Injury after Magnesium Sulphate Therapy and Placebo. A Prospective Study of Shaikh Zayed Hospital Lahore

Objective:  We evaluated the effectiveness of magnesium sulphate treatment for the management and outcome of TBI. Material and Methods:  The prospective cases (n = 112) of TBI were included from Department of Neurosurgery, Shaikh Zayed Hospital, Lahore. Patients were split into two groups. Magnesium sulphate treatment group (n = 56) and placebo group (n = 56). Detailed history of patients was taken along with comprehensive examinations with CT scans.56 TBI patients were given standard treatment plus magnesium sulphate and remaining 56 patients received just standard treatment. Results:  Mean age of the magnesium supplement therapy group was 36.83 ± 13.45 years while in the placebo group was 33.64 ± 12.88 years). Majority 28 (67.9%) were male in the magnesium sulphate group while 37 (66.1%) were in the placebo group. Mean duration passed between hospital presentation and traumatic brain injury was 4.98 ± 2.32 hours in the magnesium sulphate group while it was 5.05 ± 2.48 in the placebo group. Mean Glasgow outcome score was 3.57 ± 1.33 in the magnesium sulphate group while 2.78 ± 1.23 in the placebo group and this difference was statistically significant. Conclusion:  There is significant improvement in GOS after magnesium sulphate therapy in patients with traumatic brain injury versus placebo group as noted in the results

Fatality of salt stress to plants: Morphological, physiological and biochemical aspects

Soil salinity affects various physiological and biochemical processes which result in reduced biomass production. This adverse effect of salt stress appears on whole plant level at almost all growth stages including germination, seedling, vegetative and maturity stages. However, tolerance to salt stress at different plant developmental stages varies from species to species. The plant response to salt stress consists of numerous processes that must function in coordination to alleviate both cellular hyperosmolarity and ion disequilibrium. Salt tolerance and yield stability are complex genetic traits that are difficult to establish in crops since salt stress may occur as a catastrophic episode, be imposed continuously or intermittently and become gradually more severe at any stage during development. The objective of this review is to summarize the morphological, physiological and biochemical aspects of plants under salt stress. It was then concluded that salt stress affects plant physiology at whole plant as well as cellular levels through osmotic and ionic adjustments that result in reduced biomass production. This adverse effect of salt stress appears on whole plant level at almost all growth stages including germination, seedling, vegetative and maturity stages. Despite causing osmotic and ionic stress, salinity causes ionic imbalances that may impair the selectivity of root membranes and induce potassium deficiency.Keywords: Salt stress, ions, osmotic adjustment, morphological, physiological and biochemicalAfrican Journal of Biotechnology Vol. 9(34), pp. 5475-5480, 23 August, 201

Comparative Biochemical Analysis of High and Low Sucrose Accumulating Sugarcane Varieties at Formative Stage under Heat Stress

Sugarcane (Saccharum officinarum L) is a valuable cash crop which plays an imperative role in the worldwide economy. However, high temperature has significantly retarded the crop growth and yield by alteration of biochemical pathways. Therefore, the biochemical activities of two sugarcane varieties were explored under heat stress condition. The sugarcane cultivars S2003-US-633 (high sucrose accumulation) and SPF-238 (low sucrose accumulation) were cultivated and subjected to different temperature regimes i.e. control at 30±2 °C, heat stress at 45±2 °C and recovery at 30±2 °C for 24, 48 and 72 hours at formative stage. Detailed profiling of physiochemical attributes, sugar analysis linked with sucrose metabolism enzymes and thermotolerance indicators were investigated. S2003-US-633 exhibited better response in terms of sugar accumulation regulated by sucrose synthase, sucrose phosphate synthase and invertase activities along with more proline accumulation, total soluble protein contents with response to high temperature exposure. While S2003-US-633 is ranked as tolerant variety due to less MDA, H2O2 content and electrolytes leakage exhibiting its efficient tolerance mechanism, giving high sugar recovery rate despite harsh environmental conditions. Thus, these findings can be helpful in providing information for engineering sugar improvement along with thermotolerance in sugarcane varieties and providing new avenues towards the economic development of the country

Hybrid Polymer Composite of Prussian Red Doped Polythiophene for Adsorptive Wastewater Treatment Application

Coordination compounds as dopants to conducting polymers combine desirable properties of individual components for a synergistic effect. Prussian red (PR) a low spin iron (III) coordination compound was doped in polythiophene (PTP) matrix to explore propensity of this inorganic-organic hybrid composite material towards wastewater treatment. PR doping was observed to improve mechano, thermal, electrical, and photocatalytic attributes of pure PTP. PTP/PR composite characterization was attempted using the powder X-ray diffraction, TEM, TGA, FTIR, BET analysis and UV-Visible spectroscopy. Optimization of adsorption conditions, adsorbent regeneration, adsorption thermodynamics studies of PTP/PR were carried out using malachite green (MG) dye as a model system. Under optimized conditions 92% MG dye adsorption was observed over 20 mg PTP/PR nanocomposite in 20 minutes at pH 7. PTP/PR nanocomposite also demonstrated a complimentary performance with real wastewater samples. Thermodynamic studies indicate spontaneous process with electrostatic attraction as the predominant noncovalent interaction. This study highlights designing catalysts capable of synergistic adsorption and photocatalytic activities for effective wastewater treatment

Management and Outcome of Chronic Subdural Hematoma: A Prospective Study of Shaikh Zayed Hospital, Lahore

Background/Objective: Chronic subdural hematoma (CSH) is a type of intracranial hemorrhage is commonly seen in old age. It has a poor prognosis when misdiagnosed or a delayed treatment can lead to significant morbidity. We evaluated the effectiveness of available surgical treatments for the management and outcome of CSH.Method: The prospective cases (n = 48) of CSH were included from Department of Neurosurgery, Sheikh Zayed Hospital, Lahore during January 2014- December 2017. Detailed history of patients was taken along with comprehensive examinations with CT scans and MRIs. The CSH patients were treated surgically either with burr-hole evacuation (unilateral/bilateral) with irrigation or burr-hole drainage with drain 48 to 72 hours.Results: The mean age of male patients was 68 years and 56 years in female patients. Most of our patients recovered (81.25%; GOS 5) uneventfully. Patients were mostly treated with burr-hole evacuation with irrigation. The 15% patients had required ICU management with GOS 2-3. Older (> 65 years) male patients were at higher risk of CSH. Trauma was not the only major cause of the CSH as history of trauma was not present in the majority (< 25%) of the patients. We found following significant risk factors, i.e., hypertension (73%), DM (62.5%) and ischemic heart disease (60%) and intake of anticoagulant/antiplatelet drugs (60%). A 4% recurrence was reported in our CSH patients. Stroke as a postoperative complication was reported in two patients (4%) and only one patient (2%) died of aspiration pneumonia.Conclusion: Chronic subdural hematoma can be effectively treated by simple surgical intervention if diagnosed early and mortality can be reduced. We found burr-hole evacuation (unilateral/bilateral) with irrigation an effective treatment against CSH, as most of our patients (> 80%) were recovered with it. The trauma was not the only cause of CSH as history of trauma was not present in the majority of the patients, therefore, some other factors are also involved in the CSH formation in old age

Burnout among surgeons before and during the SARS-CoV-2 pandemic: an international survey

Background: SARS-CoV-2 pandemic has had many significant impacts within the surgical realm, and surgeons have been obligated to reconsider almost every aspect of daily clinical practice. Methods: This is a cross-sectional study reported in compliance with the CHERRIES guidelines and conducted through an online platform from June 14th to July 15th, 2020. The primary outcome was the burden of burnout during the pandemic indicated by the validated Shirom-Melamed Burnout Measure. Results: Nine hundred fifty-four surgeons completed the survey. The median length of practice was 10 years; 78.2% included were male with a median age of 37 years old, 39.5% were consultants, 68.9% were general surgeons, and 55.7% were affiliated with an academic institution. Overall, there was a significant increase in the mean burnout score during the pandemic; longer years of practice and older age were significantly associated with less burnout. There were significant reductions in the median number of outpatient visits, operated cases, on-call hours, emergency visits, and research work, so, 48.2% of respondents felt that the training resources were insufficient. The majority (81.3%) of respondents reported that their hospitals were included in the management of COVID-19, 66.5% felt their roles had been minimized; 41% were asked to assist in non-surgical medical practices, and 37.6% of respondents were included in COVID-19 management. Conclusions: There was a significant burnout among trainees. Almost all aspects of clinical and research activities were affected with a significant reduction in the volume of research, outpatient clinic visits, surgical procedures, on-call hours, and emergency cases hindering the training. Trial registration: The study was registered on clicaltrials.gov "NCT04433286" on 16/06/2020

Azimuthal anisotropy of charged jet production in root s(NN)=2.76 TeV Pb-Pb collisions

We present measurements of the azimuthal dependence of charged jet production in central and semi-central root s(NN) = 2.76 TeV Pb-Pb collisions with respect to the second harmonic event plane, quantified as nu(ch)(2) (jet). Jet finding is performed employing the anti-k(T) algorithm with a resolution parameter R = 0.2 using charged tracks from the ALICE tracking system. The contribution of the azimuthal anisotropy of the underlying event is taken into account event-by-event. The remaining (statistical) region-to-region fluctuations are removed on an ensemble basis by unfolding the jet spectra for different event plane orientations independently. Significant non-zero nu(ch)(2) (jet) is observed in semi-central collisions (30-50% centrality) for 20 <p(T)(ch) (jet) <90 GeV/c. The azimuthal dependence of the charged jet production is similar to the dependence observed for jets comprising both charged and neutral fragments, and compatible with measurements of the nu(2) of single charged particles at high p(T). Good agreement between the data and predictions from JEWEL, an event generator simulating parton shower evolution in the presence of a dense QCD medium, is found in semi-central collisions. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).Peer reviewe

Production of He-4 and (4) in Pb-Pb collisions at root(NN)-N-S=2.76 TeV at the LHC

Results on the production of He-4 and (4) nuclei in Pb-Pb collisions at root(NN)-N-S = 2.76 TeV in the rapidity range vertical bar y vertical bar <1, using the ALICE detector, are presented in this paper. The rapidity densities corresponding to 0-10% central events are found to be dN/dy4(He) = (0.8 +/- 0.4 (stat) +/- 0.3 (syst)) x 10(-6) and dN/dy4 = (1.1 +/- 0.4 (stat) +/- 0.2 (syst)) x 10(-6), respectively. This is in agreement with the statistical thermal model expectation assuming the same chemical freeze-out temperature (T-chem = 156 MeV) as for light hadrons. The measured ratio of (4)/He-4 is 1.4 +/- 0.8 (stat) +/- 0.5 (syst). (C) 2018 Published by Elsevier B.V.Peer reviewe