Robust, Bridge-less Ion-selective Electrodes with Significantly Reduced Need for Pre- and Post-application Handling

We are demonstrating robust, single-layer ion-selective electrode (ISE) utilizing simple Ag/AgCl electrode as solid support without the need for intermediate polymer layer. We have created and chemically linked a family of imidazolium ionic liquids (ILs) with poly (vinyl chloride) (PVC) using click chemistry, resulting in hybrid materials with tunable characteristics. The resultant material inherently contains chloride ion thus offering the ability to stabilize interfacial potential. This allowed us to construct very simple, single-layer membranes with significantly reduced need for conditioning as an added bonus compared to traditional sensors. Chemical immobilization of ISE membrane components also led to extended lifetime as the potential for material loss is reduced and detection limits are lowered. In our characterization we focused on perchlorate as a model ion. It\u27s levels of around 10−7 M could be repeatedly quantified over a 100 day period despite constant exposure of ISEs to aqueous solution over this time. Most importantly, the electrodes exhibited stable and reproducible signal with significantly simplified pre- and post-operation handling protocols. This offers potential for in situ applications as well as to advanced fabrication techniques and miniaturization. Simplicity of construction and operation, and low cost of the solid substrate allows for disposable ISE formats

Heterogeneous microstructure and mechanical behaviour of Al-8.3Fe-1.3V-1.8Si alloy produced by laser powder bed fusion

The relationship between processing parameters, microstructure, and mechanical properties of Al-8.3Fe-1.3V-1.8Si alloy processed by laser powder bed fusion is seldom studied. Therefore, fully dense alloys with two parameters were selected to investigate this key issue. The results show that the alloy with low power and scanning speed (S200) shows fan-shell-shaped melt pools and laser tracks while another (S350) shows a deeper and wider melt pool. Both alloys obtain a heterogeneous microstructure without a secondary phase in melt pool (MP) and a nano-sized phase in melt pool boundary (MPB). The difference between solid-solution strengthening and Orowan strengthening in MP and MPB contributes to the difference in compressive yield strength (S200: 380 ± 14 MPa and S350: 705 ± 16 MPa), and heterogeneous nano-hardness results in different crack behaviours and failure strains. This work indicates that adjusting processing parameters is an effective method to control microstructure and mechanical properties of this alloy

Role of University Education in Poverty Alleviation in Pakistan

The role of university education, a central part of most development strategies, has become controversial because expansion of PhD’s by the Higher Education Commissions (HEC) attainment has guaranteed improved economic conditions. HEC promoted the higher education by providing different indigenous and international scholarships, which ultimately improved the standard of living of the students and attainment of well reputed jobs in different institutions of Pakistan, leads to alleviate the poverty relatively. This paper reviews the role of education in promoting economic well-being focusing on the role of educational quality. Much evidence from developing countries suggests that education has strong influence in reducing poverty. The main purpose of this study was to examine the effects of some of the key macroeconomic variables on Pakistan’s economic growth during 1980-2007 taking four different education levels including students enrollment at the university level as a ratio to total employed labour force. It concludes that there is strong evidence that the cognitive skills of the population-rather than mere school attainment-are powerfully related to individual earnings, to the distribution of income, and to economic growth. University education does not play a significant role in poverty alleviation. The magnitude of change needed makes it clear that closing the economic gap with industrial countries will require major structural changes in schooling institutions

Hypersonic flow simulation by the gas-kinetic bhatnagar-gross-krook scheme

The gas-kinetic Bhatnagar–Gross–Krook (BGK) scheme is extended to hypersonic flow simulations and thus shows that the compressible inviscid flow solutions of the simulations are efficiently and accurately obtained from the BGK scheme without the disastrous shock instability phenomenon that occurs in most hypersonic flow simulations involving strong shock waves. For this particular study, the effect of chemistry in hypersonic flows has not been taken into account. Hence, the assumption of calorically perfect gas is imposed in all simulations. The high-order resolution of the scheme is achieved by utilizing monotone upstream-centered schemes for conservation laws-type initial reconstruction. While, an implicit-type time-integration method known as the approximate factorization– alternating direction implicit is adopted for computing both steady and unsteady calculations. The gas-kinetic scheme is tested meticulously in four two-dimensional numerical examples, namely, the blunt-body problem, the double Mach reflection problem, the axisymmetric blunt-body problem, and the flow over a 15-deg ramp. The numerical results of the BGK scheme when compared with the other schemes and experimental data show that this numerical technique is robust, accurate, and stable for hypersonic flow

Application of the ANOVA method in the optimization of a thermoelectric cooler-based dehumidification system

© 2022 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).In recent studies, Thermo-Electric Coolers (TEC) have been utilized for dehumidification purposes, which is mainly based on the extraction of moisture from humid atmospheric air. The reviewed literature showed that the rate of water collection from the TEC-based system can be affected by various parameters such as the module’s input voltage, the heat sink orientation, and tilt angles. In this research, the analysis of variance (ANOVA) was used to examine the significance of these factors and their interaction within the system on the TEC-based dehumidification system. Four levels were investigated for both, the Peltier’s input voltage and the rotation angle, and three levels for the tilt angle. This study indicated the significance of the studied factors and their interactions within the dehumidification system along with performing an overall numerical optimization. The experiments were conducted under the same working conditions in an enclosed environment to minimize errors. According to the overall numerical optimization, which was validated experimentally, the optimum system performance was predicted to be obtained at approximately 6.8V Peltier input volt, 65° rotation angle, and 90° tilt angles, with predicted optimum productivities of 0.32278 L/kWh and 13.03 mL/hr. For the same set of parameters, the variation between the experiment and the numerical optimization was less than 4%. The experiments show that when optimizing water collection rates for thermoelectric cooling heat sinks​ under high humidity conditions, the orientation of the heat sink should be considered.Peer reviewe

Status and diversity of coastal avian fauna in Gwadar peninsula, Balochistan

The 1050 km long coastline of Pakistan, extends from Sir Creek in the southeast of Indus delta to Gwadar Bay in the west. This article is based on diversity, habitat, status and distribution of different species of coastal birds present in the Gwadar coast. Observation of birds was done during winter season at four different sites. The habitat is important for different coastal birds like terns, gulls, pelicans and waders including resident and migratory species. A total of 55 species were recorded from the entire area. The species richness was higher at two sites. The birds were seen in higher numbers at uninhabited points compared to those near the populated area or the port. Shannon diversity index for bird community was calculated for four sites namely Shabi Estuary, Gwadar East Bay, Gwadar West Bay and Gurab, where the diversity was found to be 2.82, 2.27, 2.33 and 2.40 respectively. Birds of Common Sandpiper (Actitishy poleucos), Common Teal (Anas crecca), Wigeon (Anas Penelope), Shoveller (Anas clypeata), Pochard (Aythya ferina), Common Coot (Fulica atra), Grey Plover (Pluvialis squatarola), Kentish Plover (Charadrius alexandriunus), Dusk Red Shank (Tringa erythropus) and Great White Pelicans (Pelecanus onocrotalus) have been recorded in large numbers during the study period. Some vulnerable species for e.g. Pochard (Aythya ferina) and endangered species for e.g. Great Knot (Calidris tenuirostris), Egyptian Vulture (Neophron percnopterus), and two near threatened species Oyster catcher (Haematus ostralegus) and Dalmation Pelican (Pelecanus crispus) were also recorded. The major threats to the ecosystem are habitat degradation due to port construction, urbanization, hunting, poaching and other anthropogenic activities

Thermohydraulic analysis of covalent and noncovalent functionalized graphene nanoplatelets in circular tube fitted with turbulators

© The Author(s) 2022. This article is licensed under a Creative Commons Attribution 4.0 International. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.Covalent and non-covalent nanofluids were tested inside a circular tube fitted with twisted tape inserts with 45° and 90° helix angles. Reynolds number was 7000 ≤ Re ≤ 17,000, and thermophysical properties were assessed at 308 K. The physical model was solved numerically via a two-equation eddy-viscosity model (SST k-omega turbulence). GNPs-SDBS@DW and GNPs-COOH@DW nanofluids with concentrations (0.025 wt.%, 0.05 wt.% and 0.1 wt.%) were considered in this study. The twisted pipes' walls were heated under a constant temperature of 330 K. The current study considered six parameters: outlet temperature, heat transfer coefficient, average Nusselt number, friction factor, pressure loss, and performance evaluation criterion. In both cases (45° and 90° helix angles), GNPs-SDBS@DW nanofluids presented higher thermohydraulic performance than GNPs-COOH@DW and increased by increasing the mass fractions such as 1.17 for 0.025 wt.%, 1.19 for 0.05 wt.% and 1.26 for 0.1 wt.%. Meanwhile, in both cases (45° and 90° helix angles), the value of thermohydraulic performance using GNPs-COOH@DW was 1.02 for 0.025 wt.%, 1.05 for 0.05 wt.% and 1.02 for 0.1 wt.%.Peer reviewe

De novo insertions and deletions of predominantly paternal origin are associated with autism spectrum disorder

Whole-exome sequencing (WES) studies have demonstrated the contribution of de novo loss-of-function single-nucleotide variants (SNVs) to autism spectrum disorder (ASD). However, challenges in the reliable detection of de novo insertions and deletions (indels) have limited inclusion of these variants in prior analyses. By applying a robust indel detection method to WES data from 787 ASD families (2,963 individuals), we demonstrate that de novo frameshift indels contribute to ASD risk (OR= 1.6; 95% CI= 1.0-2.7; p= 0.03), are more common in female probands (p= 0.02), are enriched among genes encoding FMRP targets (p= 6× 10-9), and arise predominantly on the paternal chromosome (p< 0.001). On the basis of mutation rates in probands versus unaffected siblings, we conclude that de novo frameshift indels contribute to risk in approximately 3% of individuals with ASD. Finally, by observing clustering of mutations in unrelated probands, we uncover two ASD-associated genes: KMT2E (MLL5), a chromatin regulator, and RIMS1, a regulator of synaptic vesicle release

Mid-term outcomes for Endoscopic versus Open Vein Harvest: a case control study

<p>Abstract</p> <p>Background</p> <p>Saphenous vein remains the most common conduit for coronary artery bypass grafting with increasing uptake of minimally invasive harvesting techniques. While Endoscopic Vein Harvest (EVH) has been demonstrated to improve early morbidity compared to Open Vein Harvest (OVH), recent literature suggests that this may be at the expense of graft patency at one year and survival at three years.</p> <p>Methods</p> <p>We undertook a retrospective single-centre, single-surgeon, case-control study of EVH (n = 89) and OVH (n = 182). The primary endpoint was death with secondary endpoints including acute coronary syndrome, revascularisation or other major adverse cardiac events. Freedom from angina, wound complications and self-rated health status were also assessed. Where repeat angiography had been performed, this was reviewed.</p> <p>Results</p> <p>Both groups were well matched demographically and for peri-operative characteristics. All cause mortality was 2/89 (2%) and 11/182 (6%) in the EVH and OVH groups respectively. This was shown by Cox Log-Rank analysis to be non-significant (p = 0.65), even if adjusting for inpatient mortality (p = 0.74). There was no difference in the rates of freedom from angina (p = 1.00), re-admission (p = 0.78) or need for further anti-anginals (p = 1.00). There was a significant reduction in the incidence of leg wound infections and complications in the endoscopic group (EVH: 7%; OVH: 28%; p = 0.0008) and the skew of high patient self-rated health scores in the EVH group (61% compared to 52% in the open group) approached statistical significance (p = 0.06).</p> <p>Conclusions</p> <p>While aware of the limitations of this small retrospective study, we are heartened by the preliminary results and consider our data to be justification for continuing to provide patients the opportunity to have minimally invasive conduit harvest in our centre. More robust evidence is still required to elucidate the implications of endoscopic techniques on conduit patency and patient outcome, but until the results of a large, prospective and randomised trial are available, we believe we can confidently offer our patients the option and benefits of EVH.</p