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Porous carbon is considered an effective adsorbent for CO2 uptake thanks to its high textural feature, tunable surface decoration, and stable chemical/physical characteristics. Herein, a one-pot self-activating synthesis approach has been introduced to fabricate disodium 2,6-naphthalene disulfonate (NDS)-derived self-S-doped porous carbon. With this method, there is no external chemical activating agents for the activation process, and the self-activating process occurs by releasing CO, H2O, and CO2 gases during pyrolysis treatment. It was found that activating temperatures can carefully control the porous textural and elemental compositions of the as-prepared carbons. Upon the activating process, the optimal S-doped porous carbon was prepared at 700 °C, providing CO2 uptake capacities of 2.36 and 3.56 mmol/g at 25 and 0 °C and 1 bar, respectively. An in-depth investigation indicates that the joint effect of narrow microporosity and S content determines the CO2 uptake for this series of carbons. In addition, these NDS-derived self-S-doped porous carbons exhibit moderate CO2 heats of adsorption, fast adsorption kinetics, reasonable CO2/N2 selectivities, good dynamic CO2 capture capacities, and stable recyclabilities. The presented synthesis method is promising for fabricating facile carbon-based adsorbents from various organic precursors.
In this study an agricultural residue, sesame stalk, was evaluated for the removal of Ni(II) and Zn(II) metal ions from aqueous solutions. Biosorption studies were carried out at different pH, biosorbent dosage, initial metal ion concentrations, contact time, and solution temperature to determine the optimum conditions. The experimental data were modeled by Langmuir, Freundlich, Dubinin-Radushkevich (D-R) and Temkin isotherm models. Langmuir model resulted in the best fit of the biosorption data. The pseudo-first-order and pseudo-second-order kinetic models were used to describe the kinetic data and to evaluate rate constants. The best correlation was provided by the second-order kinetic model. The thermodynamic parameters such as ΔG°, ΔH° and ΔS° were calculated for predicting the nature of adsorption. The experimental results showed that sesame stalk can be used as an effective and low-cost biosorbent precursor for the removal of heavy metal ions from aqueous solutions.
In this study, the removal of copper(II) and cadmium(II) ions from aqueous solutions by biosorption onto pine cone was studied. Variables that affect the biosorption process such as pH, biosorbent dosage, initial metal ion concentration, contact time and temperature of solution were optimized. Experimental data were fitted to Langmuir, Freundlich, Dubinin Radushkevich and Temkin isotherm models to investigate the equilibrium isotherms. Pseudo-first-order, pseudo-second-order and intraparticle diffusion kinetic models were used to determine the biosorption mechanism. The thermodynamics of biosorption were studied for predicting the nature of biosorption. Experimental results showed that pine cone could be evaluated as an alternative precursor for removal of heavy metal ions from aqueous solutions, due to its high biosorption capacity, availability, and low cost.
T he potential of an arid-land plant, Euphorbia rigida E. rigida , for the removal of heavy metals [Pb II , Zn II , Cu II , Cd II , Ni II ] from aqueous solutions was studied in the current work. Batch sorption experiments were conducted to investigate the effects of pH, particle size, initial metal ion concentration, contact time and temperature. Besides, biosorption data was analysed by different isotherm and kinetic models. Equilibrium studies showed that the biosorption closely follows the Langmuir and Freundlich isotherms. From the kinetic point of view, pseudo-second order model gave the best fitting with the experimental results. The evaluated thermodynamic parameters showed that biosorption onto E. rigida was a feasible, spontaneous and endothermic process. The affinities of metal ions onto E. rigida decreased as Pb II > Zn II > Cd II > Cu II > Ni II in single metal biosorption. Besides, binary and ternary metal sorption studies were conducted to investigate the co-ion effect. Experimental results showed that E. rigida can be used as an alternative and effective low cost biosorbent for the removal of heavy metals from aqueous solutions
In this study, optimization of essential parameters, such as reaction time, reaction temperature, methanol/oil molar ratio, catalyst amount, and type of biodiesel production via transesterification, were investigated. The maximum yield under the optimal conditions was found to be ~95%. Analytical methods were used to determine the fuel characteristics of the final product. The results were compared with specified limits of the ASTM D 6751 and the EN 14214 standards. Finally, produced biodiesel was blended with five different commercial diesel fuels. B20 was found to be an optimum blend without giving any negative effect on petro diesel performance.
Bu çalışmada, kömür uçucu külü sulu çözeltilerden nikel(II) iyonlarının gideriminde düşük maliyetli adsorban olarak değerlendirilmiştir. pH, adsorban miktarı, temas süresi ve başlangıç ağır metal derişimi gibi adsorpsiyon işlemini etkileyen deneysel parametrelerin optimizasyonu gerçekleştirilmiştir. Elde edilen deneysel veriler Langmuir, Freundlich ve Dubinin-Radushkevich (D-R) izotermleri kullanılarak modellenmiştir. Langmuir modelinin adsorpsiyon verilerine daha iyi uyduğu belirlenmiştir. Uçucu külün en yüksek tek tabaka adsorpsiyon kapasitesi 294,00 mg/g olarak bulunmuştur. Yapılan çalışma, ticari adsorbanlarla karşılaştırıldığında uçucu külün sulu çözeltilerden ağır metallerin gideriminde etkin ve ekonomik bir adsorban malzemesi olabileceğini göstermiştir
In this study, the pollen morphology and exine structure of six taxa of the genus Smyrnium L. (Umbelliferae) were investigated using light microscopy and scanning electron microscopy (SEM). Eight micromorphological characters (pollen shape, apocolpium, mesocolpium, polar length, equatorial width, exine thickness, colpus length and colpus width) of pollen grains of Smyrnium have been identified. The palynological observations revealed that pollen grains of all studied taxa of Smyrnium were prolate in shape and posses tricolporate aperture. Tectal surface sculpture was not a good criterion to identify particular taxa from Smyrnium . The pollen of which is characterized by rugulate, the pollen ornamentation was similar in all studied taxa. In addition the taxa could be included in subrectangular pollen type as classified by Cerceau – Larrival.
Yapılan bu çalışmada tarımsal bir atık olan nohut samanı, sulu çözeltilerden boyar madde gideriminde biyosorbent olarak değerlendirilmiştir. Çözelti pH’ı, biyosorbent miktarı, başlangıç boyar madde derişimi, temas süresi ve çözelti sıcaklığının biyosorpsiyon işlemine olan etkileri incelenmiştir. Ayrıca, metilen mavisi biyosorpsiyonuna ait denge izoterm, termodinamik ve kinetik çalışmalar gerçekleştirilmiştir. Biyosorpsiyon denge verilerinin Freundlich izotermi ile uyumlu olduğu belirlenmiş, biyosorpsiyonu en iyi ifade edebilen kinetik modelin ise sözde(yalancı) ikinci dereceden model olduğu saptanmıştır. Hesaplanan termodinamik parametreler, biyosorpsiyonun 20-50 °C aralığında kendiliğinden gerçekleşen endotermik bir işlem olduğunu göstermiştir. Metilen mavisi biyosorpsiyonu için nohut samanının maksimum tek tabaka biyosorpsiyon kapasitesi 108,7 mg/g olarak belirlenmiştir. Sonuç olarak, nohut samanının sulu çözeltilerden metilen mavisi gideriminde çevreye dost, düşük maliyetli ve etkili bir biyosorbent olarak kullanılabileceği belirlenmiştir.
Equilibrium, thermodynamic, and kinetic studies were carried out for the adsorption of cadmium(II) ions from aqueous solution using high surface area (2,613 m2/g) microporous activated carbon prepared from Euphorbia rigida by chemical activation. Optimum adsorption conditions were determined as a function of pH, adsorbent dosage, initial metal ion concentration, contact time, and temperature of solution. Adsorption data were well described by the Langmuir isotherm model. The adsorption process obeys the pseudo-second order kinetic model. The thermodynamic parameters Δ G°, Δ H°, and Δ S° showed feasible, chemical, spontaneous, and endothermic adsorption.
Humulus lupulus, a kind of hop plant agricultural waste was pyrolyzed in a fixed bed reactor with a heating rate of 10⁰C min-1 in the presence of N2 atmosphere. The effect of pyrolysis temperature was investigated at 450, 500, 550 and 600ᴼC. The characterization of solid product (bio-char) and liquid product (bio-oil) was performed by spectroscopic and chromatographic techniques. Column chromatography, GC-MS and FT-IR analyses were used for the characterization of bio-oil; whereas FT-IR and SEM were the techniques for bio-char characterization. Experimental results showed that liquid products are available to evaluate as valuable chemicals and environmentally friendly synthetic fuels whereas solid products can be used as a low-cost adsorbent for wastewater treatments.
In this study, the removal of methylene blue from aqueous solutions by biosorption onto Elaeagnus angustifolia stone has investigated. Optimum biosorption conditions have determined as a function of pH, biosorbent dosage, initial methylene blue concentration, contact time and temperature of the solution for the removal of methylene blue. Langmuir, Freundlich and Dubinin-Radushkevich (D-R) isotherm models have used to describe the biosorption isotherm model. The experimental data have fitted to pseudo-first order, pseudo-second order and intraparticle diffusion model to examine the sorption kinetics. The values of ΔG°, ΔH° and ΔS° have calculated by thermodynamic study to determine the nature of biosorption process. Experimental results have shown that Elaeagnus angustifolia stone can be used as an effective and low cost biosorbent precursor for the removal of methylene blue from aqueous solutions.   
Bu çalışmada Suntalam ve MDF Lam levhalardan yapılan kutu konstrüksiyonlu mobilya köşe birleştirmelerinde; kavelalı, minifiksli ve alyan vidalı farklı birleştirme çeşitleri uygulanarak bunların diyagonal çekme direncine etkileri araştırılmıştır. Bu amaçla hazırlanan 72 adet numuneye diyagonal çekme deneyi uygulanmıştır. Sonuçlara göre en yüksek diyagonal çekme direnci, alyan vida ile birleştirilmiş MDF Lam levhada elde edilmiştir.
Biliary cystadenoma and cystadenocarcinomas are very rare neoplasms of the liver. The 15-year experience of the University of Ege Faculty of Medicine was retrospectively evaluated for this tumor type, which has particularities with respect to diagnosis and therapy. The clinical, histologic and surgical therapeutic features were retrospectively evaluated for 11 cases (9 female, 2 male) operated between 1989 and 2004. The mean age of the patients was 52 (range, 33-70). In six of 11 cases (56%) the initial diagnosis was hydatid cyst and three patients had undergone external drainage. All cases were totally excised. The mean tumor diameter was 8.3 cm. Differential diagnosis of this tumor group from the other cystic lesions of the liver is difficult in the initial diagnosis stage. They constitute an important disease process as they can be misinterpreted as hydatid cysts, which is an important health problem in our country, and because they have a high rate of recurrence unless they are totally resected.
Bu çalışmada Suntalam ve MDF Lam levhalardan yapılan kutu konstrüksiyonlu mobilya köşe birleştirmelerinde; kavelalı, minifiksli ve alyan vidalı farklı birleştirme çeşitleri uygulanarak bunların diyagonal çekme direncine etkileri araştırılmıştır. Bu amaçla hazırlanan 72 adet numuneye diyagonal çekme deneyi uygulanmıştır. Sonuçlara göre en yüksek diyagonal çekme direnci, alyan vida ile birleştirilmiş MDF Lam levhada elde edilmiştir.
Agricultural wastes could be a good candidate to obtain liquid, solid and gaseous fuels transformed through thermal conversion methods such as pyrolysis in power plants. Whereas, considering the complex nature of lignocellulosic structure of biomass and existence of various set of reactions involving the formation of radicals, determining biomass pyrolysis kinetics for scaling up becomes a challenge. In this study, the pyrolysis kinetics of an agricultural bio-waste, hemp stalk, was determined by a model-free method. Thermal decomposition experiments were conducted by a thermogravimetric analyzer from room temperature to 1000 °C under N 2 flow (100 mL/min -1 ) at a linear heating rate of 10 °C/min and Coats&Redfern model is utilized to calculate the kinetic parameters during degradation. Different reaction orders are assumed in the model and best fitting is decided according to the regression coefficients. As a result, the quality of the fit was found to be remarkably good in the case of assuming the order of reaction as 0.5, 1.0 and 2.0, for temperature intervals starting from 170.8, 240.1 and 380.9 °C. Moreover, a considerable change is not observed in mass loss after approximately 550 °C indicating the expiration of the main pyrolysis reactions.
Long wave equations propagating along an open channel with bottom friction are considered. The equations are cast into a non-dimensional form, Scaling and translational symmetries of the equations are calculated for the cases of constant bottom friction coefficient and variable bottom friction coefficient. Using the symmetries, the partial differential equations are transformed into ordinary differential equations. Analytical and numerical solutions of the ordinary differential equations are found and solutions are contrasted with each other.
In this study, effects of wood species and profile type at mistered profiled corner joints on the diagonal compression strength were researched. Two profile types were applied to the mitered ends of samples from Beech (Fagus orientalis Lipsky) and Scotch pine (Pinus silvestris L.)which are widely used in furniture industry as wood as species. The length of profile is longer from the other. PVA glues was used as binder. 80 samples were prepared according to the ASTM 143-88 and applied diagonal compression strength test to them. The highest diagonal compression strengths were obtained with samples from Beech wood and have longer profileKeywords: Finger Joint, Scotch pine, Beech, Diagonal Compression Strength
In this study, the production of biodiesel by transesterification of castor oil with methanol in the presence of alkali catalyst was studied. The reaction parameters such as catalyst type (potassium hydroxide, sodium hydroxide, potassium methoxide and sodium methoxide), reaction time (540 min) and reaction temperature (2565 °C) were optimized for production of castor oil methyl ester. Finally, analytical methods were applied on the final biodiesel product to determine the fuel characteristics and results were compared with the diesel standards of EN 14214 and ASTM D 6751. The present study indicates that castor oil is quite suitable for biodiesel production.
This study involves the pyrolysis of raw and impregnated hemp plant under different temperatures in a static reactor. Pyrolysis experiments were carried out with raw hemp plant at 300, 400, 500, 600 and 700 ºC with a heating rate of 10 ºC.min-1. Hemp plant was then impregnated with KOH, K2CO3 and H3PO4 and activated under static atmosphere at 300, 500, and 700 ºC. Liquid products, bio-oils, were characterized by column chromatography, elemental analysis and FTIR. Solid products, chars, were characterized by elemental analysis, FTIR and SEM. According to the results, it was found that obtaining liquid products similar to petroleum and solid products similar to commercial activated carbons from hemp plant seems possible.
Papers presented at the 13th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Portoroz, Slovenia on 17-19 July 2017 .
In this study, the optimization of chemical AC production parameters from Euphorbia rigida (ER)plant by using KOH has been investigated. The effects of activation temperature, impregnation time, impregnation ratio and activation holding time were optimized by using Response Surface Methodology (RSM).Amount of methylene blue adsorbed by produced activated carbons was evaluated as response of the system. The optimum conditions for the 300 mg/L methylene blue solution in terms of % methylene blue removal were obtained in the case of 1.5 (wt/wt) impregnation ratio, 48 hours of impregnation time, 700 °C activation temperature and 60 minutes of activation holding time and % 99.9 of MB were removed at these conditions. Consequently, the method used for optimization of experimental parameters that affect active carbon production has been confirmed to be efficient.
Daikin;Elektroprivreda Srbije;et al.;KnaufInsulation;Premogovnik;UNESCO Venice Office Regional Bureau Sci. Culture Europe
Daikin;Elektroprivreda Srbije;et al.;KnaufInsulation;Premogovnik;UNESCO Venice Office Regional Bureau Sci. Culture Europe
Bu çalışmada, farklı biyokütle atıkları kullanılarak aktif karbon ilk defa ani (flaş) ısıtma yöntemi ile üretilmiştir. Ani ısıtma yöntemiyle üretilen aktif karbonlar, sulu çözeltiden amoksisilin gideriminde adsorbent olarak kullanılmıştır. Adsorpsiyon deneyleri sonucunda elde edilen verilere farklı adsorpsiyon izoterm ve kinetik modelleri uygulanmış ve adsorpsiyon termodinamiği araştırılmıştır. Üretilen aktif karbonların amoksisilin (AMX) adsorpsiyon kapasitesi 300-500 mg/g arasında bulunmuştur. Sonuçlar değerlendirildiğinde, ani (flaş) ısıtma yöntemiyle yüzey alanı ve mikrogözenekliliği yüksek aktif karbonların amoksisilin gideriminde etkili bir adsorbent olarak kullanılabileceği belirlenmiştir.
