Current Urban Discourse,Urban Transformation and Gentrification in Istanbul

In the mid-2000s, unprecedented economic growth provided a catalyst for Istanbul's transformation. Tolga İslam outlines the background to large-scale urban development and renewal projects that have been undertaken by local authorities throughout the city. Copyright © 2010 John Wiley & Sons, Ltd.     

NO_x storage and reduction assisted by non-thermal plasma over Co/Pt/Ba/γ-Al_2O_3 catalyst using CH_4 as reductant

N_Ox storage and reduction(NSR) technology has been regarded as one of the most promising strategies for the removal of nitric oxides(NO_x) from lean-burn engines, and the potential of the plasma catalysis method for NO_x reduction has been confirmed in the past few decades. This work reports the NSR of nitric oxide(NO) by combining non-thermal plasma(NTP) and Co/Pt/Ba/γ-Al_2O_3(Co/PBA) catalyst using methane as a reductant. The experimental results reveal that the NO_x conversion of NSR assisted by NTP is notably enhanced compared to the catalytic efficiency obtained from NSR in the range of 150 °C–350 °C, and NO_x conversion of the 8% Co/PBA catalyst reaches 96.8% at 350°C. Oxygen(O_2) has a significant effect on the removal of NO_x, and the NO_x conversion increases firstly and then decreases when the O_2 concentration ranges from 2% to 10%. Water vapor reduces the NO_x storage capacity of Co/PBA catalysts on account of the competition for adsorption sites on the surface of Co/PBA catalysts. There is a negative correlation between sulfur dioxide(SO_2) and NO_x conversion in the NTP system, and the 8% Co/PBA catalyst exhibits higher NO_x conversion compared to other catalysts, which shows that Co has a certain SO_2 resistance.     

CuO掺杂对Ba(Ti_(0.91)Zr_(0.09))O_3陶瓷介电性能的影响

采用固相反应法制备了CuO掺杂的Ba(Ti0.91Zr0.09)O3陶瓷,借助XRD、SEM、Agilent4284A测试仪,研究了CuO掺杂对Ba(Ti0.91Zr0.09)O3陶瓷的结构及介电性能的影响.结果表明,CuO具有细化陶瓷晶粒的作用.随着CuO掺杂量的增加,Ba(Ti0.91Zr0.09)O3陶瓷的斜方-四方相变峰出现介电弛豫现象,相变点处的介电常数增加,并且居里峰出现相变弥散现象.当w(CuO)=0.38%时,斜方-四方相变峰的弛豫程度最大.     

预烧和烧结温度对Ba3Co0.8Zn1.2Fe24O41 铁氧体电磁性能的影响

采用固相反应法制备了Z型六角铁氧体(Ba3Co0.8Zn1.2Fe24O41).研究了预烧和烧结温度对材料电磁性能的影响.结果表明,随着预烧温度的升高磁导率先增大后减小(Tp=1250℃时为峰值),介电常数增大,介电损耗减小(低频段),但介电损耗峰增高且向低频移动;随着烧结温度的升高,磁导率的总变化趋势是先增大后减小,截止频率增高.1270℃为较佳烧结温度,此时,材料的综合性能和微观结构较好,晶粒较好,气孔较少.     

Synthesis and experimental study of novel double perovskite Ba2NixCo2−xO6 as promising oxygen carrier materials for CO2 capture application

Novel oxygen-deficient double-perovskite type oxide Ba₂Ni_xCo_2−xO₆ was applied to produce O₂/CO₂ mixed stream gas for oxyfuel combustion application. A series of different Co concentration substituted Ba₂Ni_xCo_2−xO₆ was synthesized by an EDTA-citrate sol-gel combustion method. The oxygen carriers, Ba₂Ni_0.25Co_1.75O_6, Ba₂Ni_0.45Co_1.55O₆, Ba₂Ni_0.65Co_1.35O₆ and Ba₂Ni_0.85Co_1.15O₆ were c\characterized by scanning electron microscopy and cyclic oxygen adsorption/desorption experiments. The results showed that the capacity of provided O₂ was improved by the partial substitution of Ni by Co. In addition, the synthesized perovskites exhibit good regeneration ability. The optimal degree of Co substitution was x = 0.25 for Ba₂Ni_xCo_2−xO₆ with consideration of oxygen desorption ability. Therefore, Ba₂Ni_0.25Co_1.75O₆ was selected to examine the influence of the operating parameters on the oxygen release performance. It was found that the desorption temperature and CO₂ partial pressure are the two main operating parameters for the oxygen desorption performance. Further, the proposed novel double perovskite Ba₂Ni_0.25Co_1.75O₆ provided excellent performance, the O₂ production of Ba₂Ni_0.25Co_1.75O₆ can still reach 120 mg/g after 10 cycles.     

添加助烧剂对Ba(Ti0.91Zr0.09)O3介电性能的影响

采用固相反应法制备了添加1wt％CuO—BaO混合物的Ba（Ti0.91Zr0.09）O3铁电陶瓷，借助XRD、SEM、Aglient；4284测试仪、ZT—I电滞回线测量仪，研究了预烧前和预烧后加入CuO—BaO混合物对Ba（Ti0.91Zr0.09）O3铁电陶瓷的烧结特性及介电性能的影响。结果表明：不论在预烧前和预烧后添加1wt％CuO—BaO混合物，均能有效降低Ba（Ti0.01Zr0.09）O3的烧结温度，但是在预烧前加入CuO—BaO混合物，室温介电常数高，损耗小，并且伴有介电弛豫现象，电滞回线呈现典型弛豫型铁电体的特征。     

溶胶-凝胶法合成Ba0.6Sr0.4TiO3/MgO及介电性能研究

采用溶胶-凝胶法合成了Ba_(0.6)Sr_(0.4)TiO_3/MgO复合粉体,研究了烧结温度和合成工艺对陶瓷样品介电性能的影响。研究结果表明,经650℃热处理即可得到颗粒细小均匀的超细Ba_(0.6)Sr_(0.4)TiO_3/MgO粉体,平均粒径在200 nm左右。烧结温度对陶瓷样品的介电生能有明显的影响,1300℃烧结的陶瓷样品具有优良的性能。与二步合成工艺相比,一步合成工艺制备的陶瓷样品具有更好的介(?)性能。     

微电解-生物膜复合工艺处理含Ba^2＋有机废水

采用微电解-生物膜复合工艺进行了处理含Ba^2＋有机废水的实验研究。在实验过程中，废水中的有机物由生物膜中的好氧微生物与厌氧微生物菌群作为营养源而消耗；Ba^2＋通过电沉积去除一部分，另一部分被生物膜吸收而去除。以不锈钢为阴极，石墨为阳极，pH为7．50时，Ba^2＋平均去除率为54．67％，COD平均去除率为84．91％。两极问的距离影响生化效果及电流密度，电流密度过高影响生化反应。实验结果表明，微电解-生物膜复合工艺可以实现同时降解有机物和去除重金属离子，且效果显著。     

Simultaneous removal of soot and nitrogen oxides from diesel engine exhausts

In this paper, previously reported findings and new results presented here are discussed with the main objective of establishing the reaction mechanism for soot oxidation on different supports and catalysts formulations. Catalysts containing Co, K and/or Ba supported on MgO, La₂O₃ and CeO₂ have been studied for diesel soot catalytic combustion. Among them, K/La₂O₃ and K/CeO₂ showed the best activity and stability for the combustion of soot with oxygen. A reaction mechanism involving the redox sites and the surface-carbonate species takes place on these catalysts. On the other hand, Co,K/La₂O₃ and Co,K/CeO₂ catalysts display activity for the simultaneous removal of soot and nitric oxide. The soot–catalyst contacting phenomenon was also addressed. A synergic La–K effect was observed in which the mechanical mixtures of soot with K–La₂O₃ showed higher combustion rates than those observed when K and La were directly deposited on the soot surface. The effect of the addition of Ba was explored with the aim of promoting the interaction of the solid with NO₂, thus combining the NO_x catalytic trap concept with the soot combustion for filter regeneration. Ba/CeO₂ and Ba,K/CeO₂ were effective in NO_x absorption as shown in the microbalance experiments. However, the formation of stable nitrate species inhibits the soot combustion reaction.     

Ba1-xBix(Ti0.9Zr0.1)O3陶瓷的介电弛豫特征

采用固相反应法制备了Ba1-xBix(Ti0.9Zr0.1)O3(x=0.01,0.02,0.03,0.04)陶瓷,X射线衍射分析表明所有样品均是四方晶体结构,3%mol的Bi3+能够完全溶入钙钛矿晶格中.不同频率下Ba1-xBix(Ti0.9Zr0.1)O3陶瓷的介电温谱显示所有样品均表现出弥散相变的特征,在x≥0....