An improvement of current driving and electrical conductivity properties in covetics

Compared to pure Cu, Cu lattice retaining carbon atoms, called a covetic material, can have better electrical conductivity. Furthermore, the incorporation of carbon nanostructures into Cu-alloys could improve the mechanical properties of Cu-alloys. In the simulation study, we investigated Joule heating due to applied DC current on molten Cu metal concerning how to improve current density of covetic materials. In addition, we will discuss interfacial effects on covetic-metal electrodes to meet better current driving performance. The covetic composite excited at one electrode (width = 10 nm) has a higher current drive capability as a value of 3.54 107 A/m2 , for 1000 A current at a temperature of 1073.2 K, this value is a constant while temperature is changing up to 1573.2 K. We measured the conductivity of the proposed covetic materials at various carbon nanotube densities at room temperature. Experimental results show the lowest resistivity value accomplished after mixing and temperature annealing as a value of 1.78 10−8 Ω.m, where the covetic sample has 1.27% carbon nanotube density, and that the electrical conductivity is superior to that of Cu-carbon nanotube composites previously report

KONYA/SELÇUKLU İLÇESİ KARBON AYAK İZİNİN BELİRLENMESİ

Bu çalışmada, bir ürün, hizmet veya etkinlik için karbon ayak izinin göstergesi olarak atmosfere verilen karbondioksit gazının Konya/Selçuklu ilçesi için değerlendirilmesi yapılmıştır. Emisyon hesapları sırasında, IPCC tarafından önerilen ve Tier yaklaşımlarıyla belirlenmiş olan metodoloji kullanılmıştır. Hesaplamalar soncunda Selçuklu ilçesinin 2015 yılı Karbon Ayak İzi; 0,94 milyon ton CO2 olarak bulunmuştur. Selçuklu ilçesinin Karbon Ayak İzi’ni oluşturan emisyonlar içerisinde, %56’lık oranla barınmadan kaynaklı emisyonlar başı çekmektedir. Ardından en büyük katkıyı %41 oranla ulaşım amaçlı enerji kullanımı vermektedir. En düşük emisyon kaynağı %3’lük oranla katı atıklardır. İlçede kişi başına 1,55 ton CO2, birim alan (km2) başına ise 457 ton CO2 emisyonu düşmektedir. Sonuçlar değerlendirildiğinde ilçenin Karbon Ayak İzi, dünya ortalamasına çok alındadır. Ayrıca, ilçede gerçekleştirilen yoğun ağaçlandırma çalışmaları ile yaklaşık olarak 612360 ton CO2'in tutularak ilçenin karbon ayak izinin düşmesine önemli katkıda bulunduğu ortaya çıkmıştır

Fenton oksidasyonu ile ilaç endüstrisi atıksuyundan koi gideriminin kinetik ve termodinamik değerlendirmesi

Bu çalışmada, ilaç endüstrisi atık suyundan Fenton oksidasyonu kullanılarak Kimyasal Oksijen İhtiyacı (KOİ) giderimi ile morötesi (UV) ve görünür bölgedeki absorbans değişimleri incelenmiştir. Oksidasyon reaksiyonu için kinetik ve termodinamik veriler hesaplanmıştır. Ayrıca, Fenton için belirlenen optimum dozda Foto-Fenton ve Sono-Fenton prosesleri de çalışılarak karşılaştırma yapılmıştır. İlaç endüstrisi atıksuyundan alınan numunelerin KOİ değerleri 2360-3930 mg/L aralığında bulunmuştur. Oksidasyon reaksiyonları için en uygun şartların sağlandığı optimum değerleri belirlemek için Fe(II) ve H2O2 dozları, reaksiyon süresi ve sıcaklık parametreleri çalışılmıştır. Optimum Fe(II)/H2O2 oranı 1/5 olarak saptanmıştır. Fenton reaksiyonunun ilk 10 dakika içerisinde hızlı bir şekilde gerçekleştiği ve daha sonra yavaşlayarak 60 dakika içerisinde dengeye ulaştığı gözlenmiştir. İletkenlik, Oksidasyon/Redüksiyon Potansiyeli (ORP) ve pH değerleri de izlenmiştir. Maksimum giderim verimleri Fenton için %79, Foto-Fenton için %90 ve Sono-Fenton için %86 olarak elde edilmiştir. Fenton oksidasyonu ile ilaç endüstrisi atıksuyunun arıtılması işleminin yalancı ikinci derece kinetiğe uyduğu belirlenmiştir. Serbest enerji değişimi 283 K, 293 K, 313 K ve 333 K sıcaklıklarında sırası ile -4.6, -3.2, -0.9 ve -0.2 kJ/mol olarak elde edilmiştir. Fenton prosesinin istemli olduğu ve ekzotermik özellik gösterdiği belirlenmiştir

Alternative Energy Sources in Turkey for Sustainable Development

This study is focused on the potential alterative and renewable energy sources for Turkey. A lot of alternative energy sources present in the world as well as in Turkey including hydro, solar, wind, geothermal and biomass energy. However, we can use a few amount of this sources although they can meets of world’s energy need on a large scale. Alternative energy usage has also potential to decrease CO2 emission which is responsible of global warming. Low productivity, high investment and operational cost of these methods minimize their application in a wide range. Therefore, many studies have been carried out to decline the costs and to improve the efficiency of these systems

An improvement of current driving and electrical conductivity properties incovetics

: Compared to pure Cu, Cu lattice retaining carbon atoms, called a covetic material, can have better electrical conductivity. Furthermore, the incorporation of carbon nanostructures into Cu-alloys could improve the mechanical properties of Cu-alloys. In the simulation study, we investigated Joule heating due to applied DC current on molten Cu metal concerning how to improve current density of covetic materials. In addition, we will discuss interfacial effects on covetic-metal electrodes to meet better current driving performance. The covetic composite excited at one electrode (width = 10 nm) has a higher current drive capability as a value of 3.54 107 A/m2 , for 1000 A current at a temperature of 1073.2 K, this value is a constant while temperature is changing up to 1573.2 K. We measured the conductivity of the proposed covetic materials at various carbon nanotube densities at room temperature. Experimental results show the lowest resistivity value accomplished after mixing and temperature annealing as a value of 1.78 10−8 Ω.m, where the covetic sample has 1.27% carbon nanotube density, and that the electrical conductivity is superior to that of Cu-carbon nanotube composites previously report

Application of Fenton process for decolorization of reactive black 5 from synthetic wastewater: Kinetics and thermodynamics

WOS: 000297150700004The decolorization and degradation efficiency of the azo dye Reactive Black 5 (RB5) by Fenton system were investigated in this study. The operation parameters such as Fe2+:H2O2 ratio, pH value, initial concentration of RB5, reaction time, and temperature were examined. Maximum decolorization (99%) and degradation (88% COD removal) efficiencies were achieved at the Fe2+:H2O2 ratio of 0.05 and pH 3 for 15-min reaction time. The decolorization kinetic of RB5 followed pseudo-second-order reaction kinetic. The increase of temperature caused decreasing of obtained rate constants and increasing of corresponding half-lives. The article also discussed thermodynamic parameters including changes in Gibbs free energy, enthalpy, and entropy for the decolorization of RB5 by Fenton and exposed that the oxidation process was spontaneous and exothermic under natural conditions. (c) 2010 American Institute of Chemical Engineers Environ Prog, 201

Decolorization of antraquinonic dye, Reactive Blue 114 from synthetic wastewater by Fenton process: Kinetics and thermodynamics

Karataş, Mustafa Argun, Yusuf Alparslan (Aksaray, Yazar)In this work, the decolorization of C.I. Reactive Blue 114 (RB114), a commercially important anthraquinonic dye, by Fenton processes was investigated. The effects of operating parameters, such as Fe 2+:H 2O 2 ratio, pH value, reaction time and temperature were examined. Maximum decolorization (86%) efficiencies were achieved at the Fe 2+:H 2O 2 ratio of 0.1 and pH 3 for 20min reaction time. The decolorization kinetic of RB114 followed pseudo-second-order reaction kinetic. The paper also discussed thermodynamic parameters including changes in Gibbs free energy, and activation energy for the decolorization of RB114 by Fenton and exposed that the oxidation process was spontaneous under natural conditions

Comparison of Different Extraction Methods on the Recovery Efficiencies of Valuable Components from Orange Peels

Supercritical-CO2 extraction, Soxhlet extraction, and ultrasound-assisted extraction methods were conducted in this study to recover valuable components, specifically phenolic antioxidant compounds, from orange peels. Basic operating parameters such as temperature and pressure, which affect the extraction efficiency of phenolic substances in orange peel with supercritical-CO2, were designed using the central composite design methodology. In the Soxhlet and ultrasound-assisted extraction methods, 2-hour extraction processes were carried out using ethanol at different concentrations (50%, 80% and 100%) as a solvent. Yield comparison was made by performing total phenolic content, antioxidant activity and total flavonoid content analyses in the extracts. The total phenolic content (TPC) in the extracts was determined to be 5034 mg GAE/L for supercritical-CO2 extraction at 61.5°C and 20 MPa. In comparison, Soxhlet extraction yielded a TPC of 1728 mg GAE/L, while the ultrasound-assisted extraction method resulted in a TPC of 4056 mg GAE/L. It was determined that the optimum operating parameters of supercritical-CO2 extraction were 60°C and 26.4 MPa in case all the responses were maximized. The best phenolic recovery was obtained at 100% ethanol in Soxhlet extraction and 80% ethanol in ultrasound-assisted extraction. Although supercritical-CO2 extraction is an environmentally friendly application, the recovery rate of valuable components from raw materials is lower than in Soxhlet extraction and ultrasound-assisted extraction. However, since the volume of the extracts obtained from the supercritical-CO2 extraction is small, the ratio of phenolic compounds is higher

INDOOR AIR QUALITY OF SOME SOCIAL AREAS IN KONYA CITY CENTER, TURKEY

Indoor activities, building characteristics and outdoor climatic conditions have all affected indoor environment air quality. Some peoples, especially young and unemployed persons spend on about 90 % of their times indoor environment. Indoor air quality has direct effect on human health. One of the most important parameter for indoor air quality is particulate matter (PM2.5). Therefore, determination of personal exposure to particulate matter (PM2.5) in these areas especially in café is predicted to be key role. Long exposure to particulate matters may lead to numerous diseases. In this study, particulate matter was determined in different social areas at the morning and evening for 30-sec. intervals during 15 minutes. Study area is heavily urbanized by a lot of buildings and also surrounded by roads with intensive traffic circulation. It was concluded from this study that some parameters such as ventilation, people circulation, ceiling height, construction shape and floor level have affected the measured concentration of particulate matter. The analyses have evaluated by personal Particle Meter equipment. Different conditions of the cafes for the PM values are also evaluated. Maximum and minimum PM2.5 concentrations were obtained as 3.485 µg/m3 for a Hubble-Bubble Cafe and 23 µg/m3 for a Book Store. Numbers of obtained data were found to be higher than the EPA’s standards for indoor environment. EPA established that PM concentration should be lower than 20 mg/m3 for indoors. Turkey has only outdoor air quality limitations for PM10 which is about 150 µg/m3 for long exposure and 300 µg/m3 for short exposur

Treatment of mineral-oil recovery industry wastewater by sequential aeration and Fenton's oxidation process

This study describes the treatment of preliminary aerated mineral-oil recovery industry wastewater (MORIW) using Fenton's reagent. Application parameters such as Fe2+ and H2O2 concentration, pH value, reaction period, temperature, and sludge characteristics were examined. Maximum oxidation efficiency (about 90 % COD removal and 80 % UV 254 removal) was achieved at the conditions of 0.003 Fe 2+:H2O2 ratio, 180 min reaction period, pH 3 and 293 K temperature. The oxidation process of MORIW followed pseudo-second-order reaction kinetic. The studied sludge character has a high density with settling velocity. In addition, the high settlement rate (SR) and liquid/solid ratio (L/S) values demonstrated that the formed sludge was suitable for dewatering and drying processes