Cu/cuo composite track-etched membranes for catalytic decomposition of nitrophenols and removal of as(III)

One of the promising applications of nanomaterials is to use them as catalysts and sorbents to remove toxic pollutants such as nitroaromatic compounds and heavy metal ions for environmental protection. This work reports the synthesis of Cu/CuO-deposited composite track-etched membranes through low-temperature annealing and their application in catalysis and sorption. The synthesized Cu/CuO/poly(ethylene terephthalate) (PET) composites presented efficient catalytic activity with high conversion yield in the reduction of nitro aryl compounds to their corresponding amino derivatives. It has been found that increasing the time of annealing raises the ratio of the copper(II) oxide (CuO) tenorite phase in the structure, which leads to a significant increase in the catalytic activity of the composites. The samples presented maximum catalytic activity after 5 h of annealing, where the ratio of CuO phase and the degree of crystallinity were 64.3% and 62.7%, respectively. The catalytic activity of pristine and annealed composites was tested in the reduction of 4-nitroaniline and was shown to remain practically unchanged for five consecutive test cycles. Composites annealed at 140 °C were also tested for their capacity to absorb arsenic(III) ions in cross-flow mode. It was observed that the sorption capacity of composite membranes increased by 48.7% compared to the pristine sample and reached its maximum after 10 h of annealing, then gradually decreased by 24% with further annealing. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.Ministry of Education and Science of the Republic of Kazakhstan: AP05130797Funding: A.M. gratefully acknowledges the funding of the Ministry of Education and Science of the Republic of Kazakhstan (Project AP05130797)

Application of silver-loaded composite track-etched membranes for photocatalytic decomposition of methylene blue under visible light

In this study, the use of composite track-etched membranes (TeMs) based on polyethylene terephthalate (PET) and electrolessly deposited silver microtubes (MTs) for the decomposition of toxic phenothiazine cationic dye, methylene blue (MB), under visible light was investigated. The structure and composition of the composite membranes were elucidated by scanning electron microscopy, energy dispersive spectroscopy, and X-ray diffraction technique. Under visible light irradiation, composite membrane with embedded silver MTs (Ag/PET) displayed high photocatalytic efficiency. The effects of various parameters such as initial dye concentration, temperature, and sample exposure time on the photocatalytic degradation process were studied. The decomposition reaction of MB was found to follow the Langmuir-Hinshelwood mechanism and a pseudo-first-order kinetic model. The degradation kinetics of MB accelerated with increasing temperature and activation energy, Ea, was calculated to be 20.6 kJ/mol. The reusability of the catalyst was also investigated for 11 consecutive runs without any activation and regeneration procedures. The Ag/PET composite performed at high degradation efficiency of over 68% after 11 consecutive uses. © 2021 by the authors.The research titled ?Development of functionalized composite track-etched membranes for environmental applications? (grant No AP08855527) was funded by the Ministry of Education and Science of the Republic of Kazakhstan. M.V.Z. acknowledges the International Atomic Energy Agency (IAEA) for support under coordinated research project F22070 (IAEA Research Contract No: 23152)

Kinetic and isotherm study of as(Iii) removal from aqueous solution by pet track-etched membranes loaded with copper microtubes

This paper reports on the synthesis and structure elucidation of track-etched membranes (TeMs) with electrolessly deposited copper microtubes (prepared in etched-only and oxidized polyethylene terephthalate (PET) TeMs), as well as on the comparative testing of arsenic (III) ion removal capacities through bath adsorption experiments. The structure and composition of composites were investigated by X-ray diffraction technique and scanning electron and atomic force microscopies. It was determined that adsorption followed pseudo-second-order kinetics, and the adsorption rate constants were calculated. A comparative study of the applicability of the adsorption models of Langmuir, Freundlich, and Dubinin–Radushkevich was carried out in order to describe the experimental isotherms of the prepared composite TeMs. The constants and parameters of all of the above equations were determined. By comparing the regression coefficients R2, it was shown that the Freundlich model describes the experimental data on the adsorption of arsenic through the studied samples better than others. Free energy of As(III) adsorption on the samples was determined using the Dubinin–Radushkevich isotherm model and was found to be 17.2 and 31.6 kJ/mol for Cu/PET and Cu/Ox_PET samples, respectively. The high EDr value observed for the Cu/Ox_PET composite indicates that the interaction between the adsorbate and the composite is based on chemisorption. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.The research project titled “Development of functionalized composite track-etched membranes for environmental applications” (grant No. AP08855527) was funded by the Ministry of Education and Science of the Republic of Kazakhstan

CRISPR Systems for COVID-19 Diagnosis

The emergence of the new coronavirus 2019 (COVID-19) was first seen in December 2019, which has spread rapidly and become a global pandemic. The number of cases of COVID-19 and its associated mortality have raised serious concerns worldwide. Early diagnosis of viral infection undoubtedly allows rapid intervention, disease management, and substantial control of the rapid spread of the disease. Currently, the standard approach for COVID-19 diagnosis globally is the RTqPCR test; however, the limited access to kits and associated reagents, the need for specialized lab equipment, and the need for highly skilled personnel has led to a detection slowdown. Recently, the development of clustered regularly interspaced short palindromic repeats (CRISPR)-based diagnostic systems has reshaped molecular diagnosis. The benefits of the CRISPR system such as speed, precision, specificity, strength, efficiency, and versatility have inspired researchers to develop CRISPRbased diagnostic and therapeutic methods. With the global COVID-19 outbreak, different groups have begun to design and develop diagnostic and therapeutic programs based on the efficient CRISPR system. CRISPR-based COVID-19 diagnostic systems have advantages such as a high detection speed (i.e., 30 min from raw sample to reach a result), high sensitivity and precision, portability, and no need for specialized laboratory equipment. Here, we review contemporary studies on the detection of COVID-19 based on the CRISPR system

A Novel Cu2O/ZnO@PET Composite Membrane for the Photocatalytic Degradation of Carbendazim

The extremely high levels of water pollution caused by various industrial activities represent one of the most important environmental problems. Efficient techniques and advanced materials have been extensively developed for the removal of highly toxic organic pollutants, including pesticides. This study investigated the photocatalytic degradation of the fungicide carbendazim (Czm) using composite track-etched membranes (TeMs) in an aqueous solution. Copper(I) oxide (Cu2O) and zinc oxide (ZnO) microtubes (MTs) were prepared using an electroless template deposition technique in porous poly(ethylene terephthalate) (PET) TeMs with nanochannels with a density of 4 × 107 pores/cm-2 and diameter of 385 _ 9 nm to yield Cu2O@PET and ZnO@PET composite membranes, respectively. A mixed Cu2O/ZnO@PET composite was prepared via a two-step deposition process, containing ZnO (87%) and CuZ (13%) as crystalline phases. The structure and composition of all composite membranes were elucidated using scanning electron microscopy (SEM), atomic force microscopy (AFM), energy-dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) techniques. Under UV-visible light irradiation, the Cu2O/ZnO@PET composite displayed enhanced photocatalytic activity, reaching 98% Czm degradation, higher than Cu2O@PET and ZnO@PET composites. The maximum Czm degradation efficiency from aqueous solution was obtained at an optimal pH of 6 and contact time of 140 min. The effects of various parameters such as temperature, catalyst dosage and sample exposure time on the photocatalytic degradation process were studied. The degradation reaction of Czm was found to follow the Langmuir-Hinshelwood mechanism and a pseudo-first order kinetic model. The degradation kinetics of Czm accelerated with increasing temperature, and the activation energy (Ea) levels were calculated as 11.9 kJ/mol, 14.22 kJ/mol and 15.82 kJ/mol for Cu2O/ZnO@PET, ZnO@PET and Cu2O@PET composite membranes, respectively. The reusability of the Cu2O/ZnO@PET catalyst was also investigated at different temperatures for 10 consecutive runs, without any activation or regeneration processes. The Cu2O/ZnO@PET composite exhibited degradation efficiency levels of over 50% at 14 °C and over 30% at 52 °C after 5 consecutive uses. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.Ministry of Education and Science of the Republic of KazakhstanFunding: The research titled “Development of Functionalized Composite Track-Etched Membranes for Environmental Applications” (grant No AP08855527) was funded by the Ministry of Education and Science of the Republic of Kazakhstan

Construction of metrics to evaluate effectiveness in the context of local public services

Yerel yönetimlerin farklı boyutlar açısından etkin ve etkili olarak değerlendirilmeleri, mevcut kaynakların doğru kullanılmasına, hizmet geliştirmeye ve çeşitlendirmeye, yenilikçi yönetim yaklaşımlarının uygulanmasına, sosyal-politik çevreyi oluşturan hizmetten yararlananların ihtiyaçlarına daha çok odaklanmaya bağlıdır. Mevcut girdilerin en uygun şekilde bir araya getirilip yönlendirilmemesi, genel olarak yerel kaynakların yetersizliği ya da yanlış kaynak tahsisi olarak açıklanmaktadır. Yerelde hizmet götürülen vatandaşların ve yerel baskı gruplarının beklentileri, yerel yönetimlerin de vatandaş odaklılık yönünde hizmet etme taahhütleri hem ekonomik hem de genel bir sosyo-politik performansın ortaya konulmasını gerekli kılmıştır. Yerelde kamu hizmetlerinin kamu yararı dengesini gözetmesi beklenir. Bu doğrultuda yerel hizmetlerin, salt ekonomik göstergelerden bağımsız ve etkili sunulmamasının tüm paydaşlar açısından sosyal maliyeti olmakta, bu durum hem ekonomik anlamda kaynak israfına hem de hizmet götürülen kesimin, yerel yönetimlere karşı güveninin azalmasına ve nihayeten toplumun desteğini kaybetmelerine neden olabilir. Bu çalışmanın amacı yerel yönetimlerin, sundukları hizmetlerin etkililik sorununu irdelemektir. Bu kapsamda, yerel yönetim etkililiği, verimlilik, sosyo-ekonomik, sosyo-politik göstergeler bağıntısı incelenmekte, vatandaşın günlük hayat kalitesine etkisi değerlendirilmekte ve vatandaşların ihtiyaçları temelinde bazı göstergelerin kullanımı önerilmektedir.Some further requirements for better organization of local services, such as fostering public service diversity and improvement, implementing innovative practices in service delivery, focusing on the needs of beneficiaries, are needed to enhance the efficiency and effectiveness of local governments. If and when those required inputs are not combined optimally, it has briefly been conceptualized as a lack of resources and inappropriate resource allocation. Increasing pressures of local community-groups and expectations of citizens, and local governments’ commitment to improving the user-oriented public service delivery have generated a demand for performance measurement both in an economic and socio-political manner. Local public officials must act for the balance of public interest. During the service delivery process, acting uneconomically and ineffectively do have social costs for the stakeholders and could lead to waste both available scarce resources and reduced trust towards local governments, in conclusion, lose community support. This study aims to examine the effectiveness of the services, which is supplied by local governments. In this study, we examine the relationship between local government effectiveness, productivity, socio-economic and socio-political indicators and also impact assessment of citizen's daily life quality and attempt to propose some related set of indicators to achieve local outcomes that are responsive to citizen needs

RAFT-mediated polymerization and grafting of sodium 4-styrenesulfonate from cellulose initiated via gamma-radiation

Ambient temperature (20 degrees C) reversible addition fragmentation chain transfer (RAFT) polymerization of sodium 4-styrenesulftonate (SS) conducted directly in aqueous media under gamma-irradiation at different dose rates (0.09, 0.03 and 0.02 kGy h(-1)) proceeds in a controlled fashion (typically, M-w/M-n < 1.25) to near quantitative conversions via 4-cyanopentanoic acid dithiobenzoate (CPADB) mediation. By applying CPADB modified cellulose as a macro chain transfer agent, a graft copolymer with SS was prepared in aqueous media under gamma-irradiation. RAFT mediated graft polymerizations provided copolymers with higher graft frequencies compared to those obtained by conventional methods. Thermally initiated grafting of SS from a CPADB-functionalized cellulose surface at 70 degrees C was also studied which resulted in a reduced graft frequency in comparison to gamma-initiated ones

Functionalized Nanoporous Track-Etched b-PVDF Membrane Electrodes for Heavy Metal Determination by Square-Wave Anodic Stripping Voltammetry

Track-etched functionalized nanoporous β-PVDF membrane electrodes, or functionalized membrane electrodes (FMEs), are electrodes made from track-etched, poly(acrylic acid) (PAA) functionalized nanoporous β-poly(vinylidene fluoride) (β-PVDF) membranes with thin porous Au films sputtered on each side as electrodes. To form the β-PVDF nanoporous membranes, β-PVDF films are irradiated by swift heavy ions. After irradiation, radical tracks are stable in the membranes. Chemical etching removes some of the radical tracks revealing nanopores. Radicals, remaining in the pores, initiate radio grafting of PAA from the pore walls of the nanoporous β-PVDF. PAA is a cation exchange polymer that adsorbs metal ions, such as Pb2+, from aqueous solutions thus concentrating the ions into the membrane. After a calibrated time the FME is transferred to an electrochemical cell for square-wave anodic stripping voltammetry analysis