Publication

Improving the productivity without any compromise in selectivity is major challenge in membrane-based separation. Dense reverse osmosis membranes are being used for desalination; however, the first attempt has been made to amalgamate graphene oxide with polysulfone to develop loose composite membranes. With a polymer phase concentration of 21 wt% in dope solution, the membranes are fabricated by phase inversion technique with varying concentration of graphene oxide. The membranes are characterized by various structural and morphological analytical techniques, and the cross-sectional images reveals the porous nature and formation of macrovoids in the substructure of the membrane. This confirms that the incorporation of graphene oxide increases the membrane�s porosity from 2.12% for plain polysulfone membranes to 37.1% for the composite membrane with 3.5 wt% graphene oxide additive. The pure water flux, rejection of divalent and monovalent salt solutions and antifouling studies of the composite membranes were evaluated, and it was noted that the membrane with 2.5 wt% graphene oxide nanosheets demonstrated optimum productivity and selectivity. This membrane provided a flux of 68.96 L/m2h at 5 bar operating pressure and rejection of 71.6% for MgSO4, 56.3% for MgCl2, 39.2% for Na2SO4 and 12.4% for NaCl salts and demonstrated better antifouling properties using bovine serum albumin as a foulant and exhibits 79.5% flux recovery ratio. Graphical abstract: [Figure not available: see fulltext.] � 2022, The Author(s) under exclusive licence to Iranian Society of Environmentalists (IRSEN) and Science and Research Branch, Islamic Azad University.

Water electrolysis powered by renewable energy sources to produce green hydrogen is a very promising and sustainable alternative to fossil fuels, as well as one of the best approaches for significantly reducing carbon footprints and controlling pollution. In this study, novel hybrid non-stoichiometric nanocomposite Co3S4/Co0.85Se electrocatalyst materials were synthesized using a simple and one-pot eco-friendly hydrothermal method. The as-prepared samples were characterized using X-ray diffraction (XRD) and field emission scanning electron microscope (FESEM) for structural features. Crystalline phases of Co3S4, Co0.85Se, and mixed phases in the hybrid samples were confirmed through XRD. Uniformly distributed agglomerated nanoparticles (30-80 nm) of Co3S4, clearly distinguishable nanoaggregates (20-90 nm) of Co0.85Se, and nanoflakes covered with nanoparticles (30-150 nm) of Co3S4/Co0.85Se were confirmed by FESEM. The synergistic effects of the hybrid nanocomposite due to the combination of Co3S4 (containing two different oxidation states of cobalt) and non-stoichiometric Co0.85Se, was investigated towards the oxygen evolution reaction (OER). The electrocatalytic studies confirmed that the Co3S4/Co0.85Se electrocatalyst exhibited a low overpotential of 362 mV @ +30 mA.cm?2 towards the OER in an alkaline solution in comparison with Co3S4 and Co0.85Se electrocatalysts. Furthermore, a low overpotential of 1.59 V at a high current density and a high electrochemical active surface area (ECSA) of 210 cm2 was achieved due to the combined effects of chemical coupling between the Co3S4 and Co0.85Se. Chronoamperometric studies revealed excellent stability of the hybrid nanocomposite samples with negligible changes in the overpotential, even after 30 hours of testing. The synergetic effect of cobalt chalcogenides due to the nanoscale interaction was confirmed by the enhanced electrocatalytic activity. � 2021

An investigation is planned to know how effects of powdered drywalls and to create a new mix blend proportions for concrete containing crushed and powdered gypsum wallboard and GGBS as partial replacement to cement. Results indicate gypsum wall board in powdered form along with GGBS can serve the criteria of concrete when used as 60% replacement for cement. Reference concrete mixture was compared with sustainable concrete mixtures made by replacing 15, 30, 45, 60 and 75% (by weight) of binder. The concrete bends with lesser cement replacement resulted in better mechanical properties compared to the mixes with higher cement replaced mixes. However, the concrete mixes with higher replacements exhibited higher durability compared to the mixes with lesser replacements. However, all the mixes recorded better later age strength after 28 days. Hence, the usage of above wastes in the manufacturing of concrete is recommended to reduce hazardous H2S gas emissions. � 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

In this paper we present two, low power and high speed array multiplier cells, designed with an alternate logic structure of full adder that achieves more efficiency in terms of Energy Delay Product (EDP). All the multipliers were designed using 0.18?m technology and comparison was carried out for the performance against other multipliers in terms of power delay product (PDP) and Energy delay product. Different reported adder designs were used to implement the array multipliers. The proposed multiplier-1 and proposed multiplier-2 were compared with the one with lowest EDP and a reduction of 62% and 58% respectively is achieved. � 2014 IEEE.

Oxides of nitrogen (NOx) are highly reactive and major air pollutants generated from the vehicular emission and burning of fossil fuels in industries. These pollutants will create tropospheric ozone, formation of urban smog, the occurrence of acid rain, etc. A potential solution for this would be heterogeneous photocatalysis. Using photocatalysts such as titanium dioxide (TiO2) inorganic and organic matter present in the air, such as NOx and VOCs can be adsorbed and oxidized by the action of ultraviolet (UV) light (sunlight). This technology is promising for cities with highly congested areas having high ground-level pollutant concentrations. Self-cleaning and air-purification coating with a super-hydrophilic photocatalyst (TiO2) coated on buildings can bring down the NOx concentration in the air. In addition, the incorporation of TiO2 in the form of nanoparticles into cementitious materials will enhance their mechanical properties. This study evaluates and highlights the applications of nano titanium di oxide, its effects on the fresh and hardened characteristics of the cementitious composites. � The Electrochemical Society