Experimental data in support of continuous microwave effect on emulsion polymerization of styrene

AbstractThis article contains original experimental data, figures and methods to the study of Microwave-assisted emulsion polymerization of styrene under the frame of “Enhanced Microwave Synthesis” (EMS), has been examined to investigate the advantages of Microwave (MW) power use in emulsion polymerization (Ergan et al., Eur. Polym. J. 69, 2015, 374–384). For comparative purpose, MW and conventional heating (CH) method experiments were conducted under similar conditions. By externally cooling the reaction vessel with 1,4-dioxane, constant and continuous MW power was successfully applied at isothermal condition during the polymerization. Here we give the MW power calibration data of MW-experimental system, the complete set of the experimental polymerization data and the analysis data obtained from different polymer characterization test devices (GPC, DSC and Viscometer)

Investigation of Alternative Techniques for Graphene Synthesis

In recent years, a great deal of concentration has addressed the electronic and morphological characteristics of carbonaceous substances. Nowadays, particularly, graphene is one of the most popular materials in condensed-matter physics and materials science. It is used in different fields such as desalination of seawater, smartphones, computers, satellites, planes, cars, building materials, obtaining protective coatings and rust-free cars, nuclear clean up, transistors, sensors, electron microscopy, Li ion batteries, super capacitors, and bionics. Mechanical cleaving (exfoliation), chemical exfoliation, chemical synthesis, and thermal chemical vapor deposition (CVD) synthesis are the most commonly used methods today. Some other techniques are also reported such as unzipping nanotube and microwave synthesis. In graphene synthesis, starting material is usually graphite. On the other hand, different starting materials such as rice husks, fenugreek seeds, hibiscus flower petals, camphor, alfalfa plants, petroleum asphalt are used as a carbon source for graphene synthesis. In this study, alternative methods for graphene synthesis specially microwave irradiation and ultrasound energy were studied, and the performances of the final products were compared with the help of different characterization techniques. Advantages and drawbacks of these methods were clearly discussed for enhancing the understanding of the graphene synthesis phenomena

Bullying within the Forestry Organizations of Turkey

Today, many studies are conducted in order to determine bullying behaviors and to resolve conflicts with the purpose of increasing and maintaining organizational success in developed countries. According to these studies, bullying cases are more common in public institutions when compared to other sectors. In public institutions, bullying generally occurs when successful workers are discouraged and/or harassed by their managers, thus leaving them feeling distressed and dissatisfied with their jobs. The present study examines whether forest engineers working in the seven geographical regions of Turkey are exposed to bullying behaviors, the level of any bullying, and whether there are any regional differences (N=835). Through statistical analysis, a significant relationship was determined between bullying and demographic characteristics. The results of the present study were evaluated along with the results of other studies, and some suggestions were made in order to prevent bullying behaviors in forestry organizations

Treatment of textile wastewaters by electrocoagulation: technical and economic evaluation

Bu çalışmada, bir tekstil atıksuyunun elektrokoagülasyon (EC) ile arıtılmasının sonuçları ortaya konmuştur. Demir ve alüminyum elektrotlar, monopolar paralel, monopolar seri ve bipolar seri bağlantı şekli ile kullanılmıştır. Arıtma verimliliğinin ölçülmesinde KOİ ve türbidite giderimleri dikkate alınmıştır. KOİ gideriminde, her iki elektrot materyalinde asidik ortam daha uygun olup; demir elektrot için, Bipolar Seri (BP-S) bağlantı şekli etkili olurken, alüminyum elektrotlarda ise her üç bağlantı şekli için birbirine yakın sonuçlar elde edilmiştir. Türbidite gideriminde; optimum pH’nın elektrot materyaline bağlı olduğu, alüminyum elektrotlar için asidik ortamın, demir elektrotlar için ise nötral ortamın daha uygun olduğu tespit edilmiştir. Genel olarak, yüksek akım yoğunluklarının yüksek KOİ ve türbidite giderme verimleri sağladığı görülmüştür. Düşük akım yoğunluğunda (30 A.m-2) demir elektrotlarda sadece Monopolar Paralel (MP-P) sistemden verim alınmıştır. Alüminyum elektrotlarda ise; KOİ giderimi bağlantı şekline göre değişirken, türbidite giderimi bağlantı şeklinden oldukça bağımsızdır. Diğer yandan, EC prosesi alüminyum elektrotlarla daha hızlı ilerlediğinden; her üç bağlantı için de 5 dakikalık bir süre etkili olurken, demir elektrotlarda ise; seri bağlantı sistemleriyle en az 10 dakikalık bir işlem süresine ihtiyaç duyulmakta, MP-P bağlantı şekli ise daha fazla işlem süresi gerektirmektedir. Ekonomik analizde, bir tekstil fabrikasının 1000 m3.gün-1 debide atıksuyunun EC ile arıtılmasının işletme giderleri hesaplanmıştır. Sonuç olarak, bu çalışmada EC prosesinin, kimyasal koagülasyona göre daha az materyal tüketen ve daha az çamur üreten, daha hızlı ve daha ekonomik bir proses olduğu belirlenmiştir. Anahtar kelimeler: Ekonomik analiz, elektrokoagülasyon, elektrot malzemesi, KOİ, tekstil atıksuları, türbidite.Electrocoagulation (EC) is an effective method for wastewater treatment. This paper presents the results of the treatment of a textile wastewater by EC process. Two electrode materials, aluminium and iron, were connected in three modes namely, monopolar-parallel (MP-P), monopolar-serial (MP-S), and bipolar-serial (BP-S). In MP-P mode; anodes and cathodes are in parallel connection, the current is divided between all the electrodes in relation to the resistance of the individual cells. Hence, a lower potential difference is required in parallel connection, when compared with serial connections. In MP-S configuration; each pair of sacrificial electrodes is internally connected with each other, because the cell voltages sum up, a higher potential difference is required for a given current. Otherwise, in BP-S connection; there is no electrical connection between inner electrodes, only the outer electrodes are connected to the power supply. Outer electrodes are monopolar and inner ones are bipolar. This connection mode has simple setup with and has less maintenance cost during operation. The effects of wastewater pH, current density and operating time are presented separately for two sacrificial electrode materials, Fe and Al, and three electrode connection modes mentioned above.  COD and turbidity removals were selected as performance criteria. The following conclusions may be drawn from the experimental results; acidic medium is preferable for a high COD removal for both electrode materials; iron electrode performs clearly better with BP-S mode, while the performance of aluminium is not strongly dependent on connection mode. For a high turbidity removal, the optimum pH depends on the electrode material; aluminium electrode connected in BP-S mode performs better in acidic medium, while the poor filterability of the flocs dictates pH 7 to be more suitable for the iron electrode connected in MP-S mode. High current density is generally favorable for high COD and turbidity removals in the case of iron; at low current density, MP-P mode performs better, while at high current densities, the three modes perform equally well. In the aluminium case, the effect is more pronounced on COD removal and it depends strongly on the connection mode, but it has nearly a negligible effect on the turbidity removal which also unaffected by the connection mode. In the case of aluminium, steady removal efficiencies are reached within 5 min for all three systems, while for iron electrode, serial connection systems, BP-S and MP-S reach steady values in 10 min, while MP-P needs longer operating time. For a complete technical analysis, it is worth to compare EC with conventional chemical coagulation, in regard with removal efficiencies and various important aspects. For this purpose, jar-tests were performed at laboratory scale in order to determine the adequate coagulant dosage. After choosing the best amount, same experiments have been performed to determine optimum pH value for each coagulant. Experimental conditions, removal efficiencies and some other pertinent data of electrocoagulation and chemical coagulation process variations are shown in text. At first sight, it is clearly seen that EC is faster, consumes less material and produces less sludge than chemical coagulation for similar COD and turbidity removal levels. The process using aluminium electrodes connected in MP-S mode seems to be the best choice. Meanwhile, an economic analysis is, of course, needed for a final selection. In economic analysis; the total operation cost was calculated using various experimental dataset such as; energy consumption, sacrificial electrode material, chemicals and sludge amounts per m3 of wastewater for a textile plant with 1000 m3.day-1 of wastewater. Iron is preferred as a low cost one for electrocogulation. On the other hand, FeCl3 is the preferable salt in view of its techno-economic performance for CC. Finally, when EC and CC are compared both technically and economically, the following results may be drawn; the COD removal performance of CC is 10% higher than EC, the turbidity removal is nearly the same, but in 60% longer retention time. With the same initial pH, the final pH is 7.9 in EC, but 2.9 in CC. The final acidic and chloride bearing medium is an important drawback of CC, causing severe corrosion problems which may necessitate high-cost building materials. From this point, Fe2(SO4)3.7H2O may be used despite of its higher operating cost. High coagulant consumption in CC means high chloride concentration in the effluent. Finally, and more importantly, the operating cost of CC is 3.2 times as high as the operating cost of EC. Keywords: COD, economic analysis, electrocoagulation, electrode material, textile wastewaters, turbidity

A research on wood based forest products in Turkey: Time series analysis

The developing technology has increased the demand for all kinds of wood products. This has resulted in the use of efficient and productive use of resources as well as sustainable use. Time series analysis is also used as an important tool in the planning of forests with wood raw materials because it allows to estimate the future values of existing variables. The General Directorate of Forestry has to organize sales strategies and incomes according to these plans as the public institution responsible for the management of forests. In this context, sales and income forecasts for the year 2017-2027 were made for models produced from sales of industrial wood, stumpage and fuelwood and income data for the year 2001-2016. As a result of the study, it is expected that the sales of industrial wood and stumpage will increase by 4.96 million m3 and 564 thousand m3 for the end of 2027 respectively, while the fuelwood income decreases by 1.11 million stere. These estimates will change according to the political and economic consequences for the future. Nevertheless, it is important for decision-makers to formulate their plans in view of forestry and Turkish economy, especially in view of the outputs from such studies, although the number is inadequate

Adaptive neuro-fuzzy based modelling for prediction of air pollution daily levels in city of Zonguldak

Air pollution is a growing problem arising from domestic heating, high density of vehicle traffic, electricity production, and expanding commercial and industrial activities, all increasing in parallel with urban population. Monitoring and forecasting of air quality parameters in the urban area are important due to health impact. Artificial intelligent techniques are successfully used in modelling of highly complex and non-linear phenomena. In this study, adaptive neuro-fuzzy logic method has been proposed to estimate the impact of meteorological factors on SO2 and total suspended particular matter (TSP) pollution levels over an urban area. The model forecasts satisfactorily the trends in SO2 and TSP concentration levels, with performance between 75-90% and 69-80 %, respectively. © 2005 Elsevier Ltd. All rights reserved.2002-45-10-16This study was supported by Zonguldak Karaelmas University, research Grant no. 2002-45-10-16

INVESTIGATION OF THERMAL AND NON-THERMAL INTERACTIONS OF MICROWAVES WITH MATERIALS AND MICROWAVE CHEMISTRY

The use of microwaves in industry has generated interest recently as an alternative to classic thermal heating because of the drastic reduction in the processing time. In spite of the fact that there is a wide application of microwaves, the interaction mechanism between microwaves and materials has not been well understood. Nowadays, the fact that there is a debate on the alternative use of microwaves is on not the dielectric heating which is well known but microwave specific effect. In this article there are reports which show similar kinetic in both microwave and classic thermal methods at similar temperature and simple dielectric heating of materials under microwaves conditions. There are also reports which show a clear reaction rate enhancement by microwave radiation compared to the thermal method under similar reactions conditions and temperatures indicating microwave specific effect. In addition, the study on the effects of microwaves on chemical reactions and hypothesis associated with the microwave effects will discuss