Climatic variations in comfortable temperatures: the Pakistan projects

Two thermal comfort surveys in Pakistan are described. One was longitudinal conducted in summer and winter, the other was transverse with monthly surveys over a whole year. The surveys were conducted in five cities each representing a particular climatic region. The use of building controls and clothing is analysed. There is close agreement between the findings of the two surveys despite differences in methodology. The surveys show that there is a definite relationship between indoor comfort and outdoor conditions in line with an adaptive approach to thermal comfort. The current International Standard does not accurately reflect these. Because of the large variations in indoor temperature in many Pakistani buildings, the surveys also indicate the limits of people's ability to adapt to indoor temperatures.     

Abrasive wear behavior of boronized AISI 8620 steel

In this study, AISI 8620 steel was boronized using the solid state boronizing technique. Processes were carried out at the temperatures of 850, 900 and 950 °C for 2, 4 and 6 h of treatment. Abrasive wear behavior of the samples boronized at different temperatures and treatment durations have been examined. Using boronized and unboronized samples, abrasive tests were conducted using pin on disc test apparatus. 80 and 120 mesh aluminum oxide (Al₂O₃) abrasive papers were used in the abrasion experiments and the samples were subjected to abrasion under 10, 20 and 30 N loads. Boronized steels exhibited an improvement in abrasive wear resistance reaching up to 500%. Microstructures and wear surfaces of the samples were inspected using SEM microscopy. SEM examinations revealed that the thickness of the boride layer on the steel surfaces changes with changing process durations and temperatures. The presence of boride formed in the borided layer at the surface of the steels were determined by XRD analysis and microhardness values of the iron borides (FeB, Fe₂B) formed on the steel surface were found to be over 1600 HV.     

Variation in accumulation of heavy metals in different verities of sunflower seed oil with the aid of multivariate technique

In this work, three heavy metals (HMs) cadmium, lead, and zinc were determined in 16 newly breaded varieties of sunflower seed oil, using atomic absorption spectrometry, prior to use of microwave-assisted acid digestion method (MWD). The accuracy of the proposed method was studied by standard addition method and values obtained by conventional wet acid digestion methods (CAM) on same samples. The detection limit obtained from the standard addition curve was 0.327, 3.38, 10.0 ng/ml for Cd, Pb, and Zn, respectively, with high percentage recoveries. Multivariate statistical techniques (cluster and principal component analysis) were applied to modeling classes of different varieties of sunflower seed oils grown in same agricultural plot, on the basis of the analytical data of HMs. The results obtained providing sufficient information on tolerable limit of all three HMs by different varieties of sunflower oil to grow safely.     

One-step sonochemical synthesis of NiMn-LDH for supercapacitors and overall water splitting

Transition metals are attracting numerous interests for their substantial applications in supercapacitors and as non-noble metal electrocatalyst for overall water splitting. Herein, the NiMn layer double hydroxide (NiMn-LDH) is developed using the sonochemical route at different reaction times, which act as a multifunctional electrode for supercapacitors and overall water splitting. The capacitance of layer double hydroxide (LDH) synthesized at 4 h (NiMn-LDH-4 h) of reaction time was found to be 527 F g^?1 at 1 A g^?1, with 91.2% capacitance retention after 5,000 cycles at 2 A g^?1 in 6 M KOH. For hydrogen and oxygen evolution reactions, the NiMn-LDH-4 h electrode exhibits a standard of 10 mA cm^?2 at an overpotential of 120 mV and 296 mV, respectively, in 1 M KOH. Moreover, fabricated NiMn-LDH-4 h||NiMn-LDH-4 h electrolyzer for overall water splitting benchmarks 10 mA cm^?2 at 1.6 V. The superior electrochemical properties of the NiMn-LDH electrodes might be attributed to quick diffusion paths and enhanced redox reaction of NiMn-LDH nanosheets because of the high surface area.

     

Growth of a Highly Porous Coordination Polymer on a Macroporous Polymer Monolith Support for Enhanced Immobilized Metal Ion Affinity Chromatographic Enrichment of Phosphopeptides

A simple room temperature solution‐based method for the preparation of highly porous iron(III) benzenetricarboxylate coordination polymer films on the internal surface of a macroporous polystyrene‐divinylbenzene‐methacrylic acid polymer is reported. The resulting metal‐organic polymer hybrid (MOPH) maintains a high specific micropore surface area of 389 m² g^‐1 and thermal stability above 250 °C in air. The MOPH preparation is readily adapted to a capillary column, yielding a flow‐through separation device with excellent flow permeability and modest back‐pressure. The excellent separation capability of the MOPH column is demonstrated by enriching phosphopeptides from mixtures of digested proteins. This approach to MOPH synthesis is easily implemented and likely adaptable to a wide range of coordination polymers and metal‐organic frameworks.     

Improvement in the spheroidizing annealing of low-carbon steel for cold upsetting

A new method has been developed for more intense spheroidization of cementite. The method employs preliminary conversion of the steel to bainite structure. Spheroidization is produced by nonisothermal holding at high temperatures, by means of an internal heat source, so as to ensure the Geveling effect. This method may be used in production lines.