A new processable donor–acceptor polymer displaying neutral state yellow electrochromism

We report here the synthesis of a new solution processable neutral state yellow polymeric electrochromic material containing 2,5-bis-dithienyl-1H-pyrrole (SNS)-donor and 1,8 naphthalimide-acceptor (SNS–NI) as a subunit. The electrochemical and optical properties were investigated via cyclic voltammetry (CV), UV–Vis absorption and fluorescence emission measurements, respectively. Besides, electrochromic performance of poly(SNS–NI) has been compared to the both the film preparation method and poly(1-phenyl-2,5-dithiophen-2-ylpyrrole) [poly(SNS–P)] as a standard polymer. In the poly(SNS–NI), yellow color of the polymer film at neutral state converted to green and then dark blue upon the polymer film fully oxidized in the positive regime. SNS–NI polymer film prepared via spin casting process exhibits a high contrast ratio in the near-IR region (ΔT% = 56% at 890 nm), a response time of about 1 s, high coloration efficiency (299 cm² C⁻¹) and retained its performance by 98.6% even after 5000 cycles. Finally, the results clearly indicate that both electronic nature of the molecule and film preparation method have a major impact on electrochromic performance of these polymers.     

Investigation of the effect of zeolite,bentonite, and basalt fiber as natural reinforcing materials on the material properties of PPS and CF-reinforced PPS

This study was performed to expand the usage area of phenylene sulfide (PSS) by reducing its cost without deteriorating the material properties. For this purpose, mechanical, thermo-mechanical and abrasion tests were conducted to composite materials obtained by adding carbon fiber (CF), basalt fiber (BF), zeolite, and bentonite into PPS, and the effects of additive type and ratio were examined. For the test samples, fabricated by the melt blending, the fiber content was 10 wt.%, while zeolite, and bentonite ratios were 1, 5, and 10 wt.%. According to tensile and abrasion test results, zeolite, and bentonite improved the properties of fiber-reinforced PPS by showing a synergistic effect. It has been demonstrated in this research that the cost of fiber-reinforced PPS matrix composites, which are widely used in advanced engineering applications, can be reduced by using natural minerals zeolite and bentonite without sacrificing material properties. Findings obtained from mechanical and wear tests, revealed that the composition containing 10, 10, and 80 wt.%, zeolite, CF, and PPS, respectively, exhibited optimum material properties. BF for PPS has been shown to be an alternative reinforcement to CF, as it exhibits the lowest wear rate and better interacts with particles in the matrix.     

Synthesis and characterization of graft copolymer of sodium alginate and poly(itaconic acid) by the redox system

In this study, grafting of itaconic acid (IA) onto sodium alginate (NaAlg) using cerium(IV) ammonium nitrate/nitric acid (CAN/HNO₃) as redox system was carried out by free radical polymerization. The structures of the grafted copolymers (NaAlg-g-PIA) were characterized by ATR-FTIR spectroscopy, NMR spectroscopy, scanning electron microscopy, and thermogravimetric analysis. The reaction conditions for maximum grafting were optimized by varying the reaction time, temperature, percentage of sodium alginate, monomer, initiator, and nitric acid concentrations. The optimum reaction conditions were obtained with reaction time of 5 h, reaction temperature of 30 °C, IA concentration of 0.92 M, CAN concentration of 1.368 × 10^?1 M, HNO₃ concentration of 0.094 M and percentage of NaAlg 0.5 g/dL. The solubility test of NaAlg-g-PIA was also investigated using solvents. The results indicate that prepared graft copolymer was non-soluble in the various solvents, while it was soluble only in saturated solution of NaOH and promising as an adsorbent.     

Reuse of glass waste in the manufacture of ceramic tableware glazes

Today, various studies are carried out to spread the understanding of sustainability. The sustainability of production processes gains importance in corporate areas. In this study, the use of glass waste instead of frit used in glaze compositions in the ceramic industry was evaluated. The chemical and physical properties of glass wastes on samples were examined. The glaze formulations were prepared using 3%, 5%, and 8% by weight of glass waste instead of frit. Glass wastes were added to glaze compositions and 12 different glaze formulation studies were carried out. Transparent, Opaque, and Matte test glazes were prepared with glass waste added glaze formulations, and these glazes were applied to ceramic bodies. SEM (scanning electron microscope) analysis of standard glaze and glass waste added glazes was performed to determine the microstructural and morphological characterizations. Also, surface whiteness, brightness, L*a*b values, glaze flows, harcort test results, and final water absorption values were compared. As a result of the studies, it has been determined that it is appropriate to use 3% glass waste by weight instead of the frit in the production of ceramic tableware.     

紫外可见光谱区分光光度计的标准化

紫外可见光谱测量通常用于实验室的定性和定量分析。为确保测量值可靠,实验仪器必须经过校准。埃及国家标准化所建立了一种光度测定法,其吸收和传输能力满足国际和国家要求。本文介绍了紫外可见光谱测及测量仪,讨论了影响测量可靠性的因素,并讨论了包含相关测量参数的不确定度模型。     

Preparation and characterization of some substituted bioglasses and their ceramic derivatives from the system SiO2–Na2O–CaO–P2O5 and effect of gamma irradiation

Glasses having chemical composition based on Hench's bioglass^® and with some substituted oxides were prepared and crystallized through thermal treatments. These glasses and corresponding glass–ceramics were characterized by Fourier transform infrared spectroscopy (FTIR) either through absorption or reflection studies. Chemical corrosion of the prepared glassy and crystalline samples as grains was examined by the action of 0.1 M HCl or NaOH solutions or by distilled water. Also, UV–vis absorption measurements were carried out before and after successive gamma rays to reveal their response to ionizing radiation.

The formation of hydroxyapatite layer was checked by FTIR studies and X-ray diffraction experiments which show that the crystalline soda lime silicate phase (1Na₂O·2CaO·3SiO₂) is separated as the main phase in all tested glasses beside some secondary phases depending on the introduced substituted oxide. The corrosion behavior was found to vary depending on the type of the introduced oxides and their ability to freely ion exchange and dissolve in the leaching solution.     

Energy efficiency in pumps

In this paper, “energy efficiency” studies, done in a big industrial facility’s pumps, are reported. For this purpose; the flow rate, pressure and temperature have been measured for each pump in different operating conditions and at maximum load. In addition, the electrical power drawn by the electric motor has been measured. The efficiencies of the existing pumps and electric motor have been calculated by using the measured data.

Potential energy saving opportunities have been studied by taking into account the results of the calculations for each pump and electric motor. As a conclusion, improvements should be made each system. The required investment costs for these improvements have been determined, and simple payback periods have been calculated.

The main energy saving opportunities result from: replacements of the existing low efficiency pumps, maintenance of the pumps whose efficiencies start to decline at certain range, replacements of high power electric motors with electric motors that have suitable power, usage of high efficiency electric motors and elimination of cavitation problems.     

Cost optimization of feed mixes by genetic algorithms

The cost optimization is a key element to determine the least-cost feed mixture according to animals’ nutrient requirements and the effective use of the sources. In this paper, the cost optimization of feeds is performed by genetic algorithm, considering the growing style and type, age, nutritional requirement and feedstuff costs for poultry and different types of animals. The proposed method is compared with linear programming approach to measure its performance. The obtained results show that Genetic algorithms could be applicable to the cost optimization of the feed mixtures. In addition, a software program is developed by using Delphi environment, which provides flexible, extensible and user-friendly framework for tuning the heuristic relevant parameters and improving the solution quality.     

Antioxidant activity of stem and root extracts of Rhubarb (Rheum ribes): An edible medicinal plant

The antioxidant activity of chloroform and methanol extract of roots and stems of Rhubarb (Rheum ribes L.), which are used for medicinal purposes and also its fresh stems and petioles are consumed as vegetable, was studied. The antioxidant potential of both extracts of roots and stems were evaluated using different antioxidant tests, namely total antioxidant (lipid peroxidation inhibition activity), DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging, superoxide anion radical scavenging, ferric reducing power, and cupric reducing power (CUPRAC), and metal chelating activities. Total antioxidant activity was also measured according to the β-carotene bleaching method, and all four extracts exhibited stronger activity than known standards, namely butylated hydroxytoluene (BHT) and α-tocopherol. Particularly, higher activity was exhibited by roots with 93.1% and 84.1% inhibitions of chloroform and methanol extracts, while 82.2% and 82.0% inhibitions by stem extracts, respectively. However, both methanol extracts exhibited higher DPPH radical scavenging activity than the corresponding chloroform extracts, moreover, methanol extract of the stems showed better activity than BHT. In addition, both root extracts showed more potent superoxide anion radical scavenging activity than BHT, and comparable with well known radical scavenger l-ascorbic acid. Except chloroform extract of the roots, the other three extracts exhibited better metal chelating activity than quercetin. Also, total phenolic and flavonoid contents in both extracts of the roots and stems of R. ribes were determined as pyrocatechol and quercetin equivalents, respectively.     

Sunscreen Ingredient Octocrylene’s Potency to Disrupt Vitamin D Synthesis

Octocrylene is a widely used ingredient in sunscreen products, and it has been observed that the use of sunscreen has been increasing over the last few decades. In this paper, we investigated the way in which sunscreen’s ingredient octocrylene may disrupt normal vitamin D synthesis pathway, resulting in an imbalance in vitamin D levels in the body. The key techniques used for this insilico investigation were molecular docking, molecular dynamic (MD) simulation, and MMPBSA-based assessment. Vitamin D abnormalities have become very common in human health. Unknown exposure to chemicals may be one of the important risk factors. In molecular docking analysis, octocrylene exhibited a binding energy of −11.52 kcal/mol with vitamin D binding protein (1KXP) and −11.71 for the calcitriol native ligand. Octocrylene had a binding potency of −11.152 kcal/mol with the vitamin D receptor (1DB1), and calcitriol had a binding potency of −8.73 kcal/mol. In addition, octocrylene has shown binding energy of −8.96 kcal/mol with CYP2R1, and the calcitriol binding energy was −10.36 kcal/mol. Regarding stability, the root-mean-square deviation (RMSD), the root-mean-square fluctuation (RMSF), the radius of gyration, hydrogen bonding, and the solvent-accessible surface area (SASA) exhibited that octocrylene has a stable binding pattern similar to calcitriol. These findings revealed that incessant exposure to octocrylene may disrupt normal vitamin D synthesis.