State-selective charge exchange cross sections in collisions of highly-charged sulfur ions with helium and molecular hydrogen

The state-selective cross section data are useful for understanding and modeling the x-ray emission in celestial observations.In the present work,using the cold target recoil ion momentum spectroscopy,for the first time we investigated the state-selective single electron capture processes for S^(q+)–He and H_(2)(q=11–15)collision systems at an impact energy of q×20 keV and obtained the relative state-selective cross sections.The results indicate that only a few principal quantum states of the projectile energy level are populated in a single electron capture process.In particular,the increase of the projectile charge state leads to the population of the states with higher principal quantum numbers.It is also shown that the experimental averaged n-shell populations are reproduced well by the over-barrier model.The database is openly available in Science Data Bank at 10.57760/sciencedb.j00113.00091.

Absolute partial and total ionization cross sections of carbon monoxide with electron collision from 350 eV to 8000 eV

The absolute partial and total cross sections for electron impact ionization of carbon monoxide are reported for electron energies from 350 eV to 8000 eV.The product ions(CO^(+),C^(+),O^(+),CO^(2+),C^(2+),and O^(2+))are measured by employing an ion imaging mass spectrometer and two ion-pair dissociation channels(C^(+)+O^(+)and C^(2+)+O^(+))are identified.The absolute cross sections for producing individual ions and their total,as well as for the ion-pair dissociation channels are obtained by normalizing the data of CO^(+)to that of Ar^(+)from CO-Ar mixture target with a fixed 1:1 ratio.The overall errors are evaluated by considering various kinds of uncertainties.A comprehensive comparison is made with the available data,which shows a good agreement with each other over the energy ranges that are overlapped.This work presents new cross-section data with electron energies above 1000 eV.

Nitric oxide removal from flue gas coupled with the Fe^(II)EDTA regeneration by ultraviolet irradiation

During wet complexation denitrification of flue gas,Fe^(II)EDTA regeneration,also known as reducing Fe^(II)IEDTA and Fe^(II)EDTA-nitric oxide(NO)to Fe^(II)EDTA,is crucial.In this paper,ultraviolet(UV)light was used for the first time to reduce Fe^(II)EDTA-NO.The experimental result demonstrated that Fe^(II)EDTA-NO reduction rate increased with UV power increasing,elevated temperature,and initial Fe^(II)EDTA-NO concentration decreasing.Fe^(II)EDTA-NO reduction rate increased first and then decreased as pH value increased(2.0e10.0).Fe^(II)EDTA-NO reduction with UV irradiation presented a first order reaction with respect to Fe^(II)EDTA-NO.Compared with other Fe^(II)EDTA regeneration methods,Fe^(II)EDTA regeneration with UV show more superiority through comprehensive consideration of regeneration rate and procedure.Subsequently,NO absorption experiment by Fe^(II)EDTA solution with UV irradiation confirmed that UV can significantly promote the NO removal performance of Fe^(II)EDTA.Appropriate oxygen concentration(3%(vol))and acidic environment(pH=4)was favorable for NO removal.With UV power increasing as well as temperature decreasing,NO removal efficiency rose.In addition,the mechanism research indicates that NO from flue gas is mostly converted to NO_(2)-,NO_(3)-,NH_(4)^(+),N_(2),and N_(2)O with Fe^(II)EDTA absorption liquid with UV irradiation.UV strengthens NO removal in Fe^(II)EDTA absorption liquid by forming a synergistic effect of oxidationereductionecomplexation.Finally,compared with NO removal methods with Fe^(II)EDTA,Fe^(II)EDTA combined UV system shows prominent technology advantage in terms of economy and secondary pollution.

Billroth II anastomosis combined with brown anastomosis reduce reflux gastritis in gastric cancer patients

BACKGROUND The surgeon performing a distal gastrectomy,has an arsenal of reconstruction techniques at his disposal,Billroth II among them.Braun anastomosis performed during a Billroth II procedure has shown evidence of superiority over typical Billroth II,in terms of survival,with no impact on postoperative morbidity and mortality.AIM To compare Billroth II vs Billroth II and Braun following distal gastrectomy,regarding their postoperative course.METHODS Patients who underwent distal gastrectomy during 2002-2021,were separated into two groups,depending on the surgical technique used(Billroth II:74 patients and Billroth II and Braun:28 patients).The daily output of the nasogastric tube(NGT),the postoperative day that NGT was removed and the day the patient started per os feeding were recorded.Postoperative complications were at the same time noted.Data were then statistically analyzed.RESULTS There was difference in the mean NGT removal day and the mean start feeding day.Mean total postoperative NGT output was lower in Braun group(399.17 mL vs 1102.78 mL)and it was statistically significant(P<0.0001).Mean daily postoperative NGT output was also statistically significantly lower in Braun group.According to the postoperative follow up 40 patient experienced bile reflux and alkaline gastritis from the Billroth II group,while 9 patients who underwent Christodoulidis G et al.Billroth II and Braun compared with Billroth II WJM https://www.wjgnet.com 2 March 20,2024 Volume 14 Issue 1 Billroth II and Braun anastomosis were presented with the same conditions(P<0.05).CONCLUSION There was evidence of superiority of Billroth II and Braun vs typical Billroth II in terms of bile reflux,alkaline gastritis and NGT output.

Characteristics of the SOL ion-to-electron temperature ratio on the J-TEXT tokamak with different plasma configurations

Accurate measurement of the average plasma parameters in the edge region,including the temperature and density of electrons and ions,is critical for understanding the characteristics of the scrape-off layer(SOL) and divertor plasma transport in magnetically confined fusion research.On the J-TEXT tokamak,a multi-channel retarding field analyzer(RFA) probe has been developed to study average plasma parameters in the edge region under various poloidal divertor and island divertor configurations.The edge radial profile of the ion-to-electron temperature ratio,τ_(i/e),has been determined,which gradually decreases as the SOL ion self-collisionality,v_(SOL)*,increases.This is broadly consistent with what has been observed previously from various tokamak experiments.However,the comparison of experimental results under different configurations shows that in the poloidal divertor configuration,even under the same v_(SOL)*,τ_(i/e) in the SOL region becomes smaller as the distance from the X-point to the target plate increases.In the island divertor configuration,τ_(i/e) near the O-point is higher than that near the X-point at the same v_(SOL)*,and both are higher than those in the limiter configuration.These results suggest that the magnetic configuration plays a critical role in the energy distributions between electrons and ions at the plasma boundary.

Semi-implantable device based on multiplexed microfilament electrode cluster for continuous monitoring of physiological ions

Modern medicine is increasingly interested in advanced sensors to detect and analyze biochemical indicators.Ion sensors based on potentiometric methods are a promising platform for monitoring physiological ions in biological subjects.Current semi-implantable devices are mainly based on single-parameter detection.Miniaturized semi-implantable electrodes for multiparameter sensing have more restrictions on the electrode size due to biocompatibility considerations,but reducing the electrode surface area could potentially limit electrode sensitivity.This study developed a semi-implantable device system comprising a multiplexed microfilament electrode cluster(MMEC)and a printed circuit board for real-time monitoring of intra-tissue K^(+),Ca^(2+),and Na^(+)concentrations.The electrode surface area was less important for the potentiometric sensing mechanism,suggesting the feasibility of using a tiny fiber-like electrode for potentiometric sensing.The MMEC device exhibited a broad linear response(K^(+):2–32 mmol/L;Ca^(2+):0.5–4 mmol/L;Na^(+):10–160 mmol/L),high sensitivity(about 20–45 mV/decade),temporal stability(>2weeks),and good selectivity(>80%)for the above ions.In vitro detection and in vivo subcutaneous and brain experiment results showed that the MMEC system exhibits good multi-ion monitoring performance in several complex environments.This work provides a platform for the continuous real-time monitoring of ion fluctuations in different situations and has implications for developing smart sensors to monitor human health.

Do tensile and shear forces exerted on cells influence mechanotransduction through stored energy considerations?

All tissues in the body are subjected externally to gravity and internally by collagenfibril and cellular retractive forces that create stress and energy equilibrium required for homeostasis.Mechanotransduction involves mechanical work(force through a distance)and energy storage as kinetic and potential energy.This leads to changes in cell mitosis or apoptosis and the synthesis or loss of tissue components.It involves the application of energy directly to cells through integrin-mediated processes,cell-cell connections,stretching of the cell cytoplasm,and activation of the cell nucleus via yes-associated protein(YAP)and transcriptional coactivator with PDZ-motif(TAZ).These processes involve numerous complexes,intermediate molecules,and multiple pathways.Several pathways have been identified from research studies on vertebrate cell culture and from studies in invertebrates.These pathways involve mechanosensors and other molecules that activate the pathways.This review discusses the mitogen-activated protein kinase(MAPK)family,Hippo,Hedgehog,and Wingless-related integration site(WNT)/βcatenin signaling pathways.The mediators covered includeβcatenin,ion channels,growth factors,hormone receptors,members of the Ras superfamily,and components of the linker of nucleoskeleton and cytoskeleton(LINC)complex.However,the interrelationship among the different pathways remains to be clarified.Integrin-mediated mechanotransduction involves direct tensile loading and energy applied to the cell membrane via collagenfibril stretching.This energy is transferred between cells by stretching the cell-cell connections involving cadherins and the WNT/βcatenin pathway.These alterations induce changes in intracellular events in the cytoskeleton and nuclear skeleton caused by the release of YAP and TAZ.These coactivators then penetrate through the nuclear pores and influence nuclear cell function.Alteration in the balance of forces and energy applied to cells and tissues is hypothesized to shift the cell-extracellular matrix mechanical equilibrium by modifying mechanotransduction.The shift in equilibrium can lead to either tissue synthesis,genetic modifications,or promotefibrotic diseases,including epithelial cell-derived cancers,depending on the local metabolic conditions.

基于区间毕达哥拉斯犹豫模糊熵和交叉熵的ELECTRE II决策方法

针对属性权重完全未知或部分已知,属性值为区间毕达哥拉斯犹豫模糊数的多属性决策问题,提出了基于区间毕达哥拉斯犹豫模糊熵和交叉熵的ELECTRE II法。首先给出区间毕达哥拉斯犹豫模糊数的区间形式的得分函数和精度函数,定义新的距离测度。然后基于区间毕达哥拉斯犹豫模糊数的模糊因子、直觉因子和幅度因子,给出熵和交叉熵公式,并证明其性质,提出了基于熵和交叉熵确定属性权重的方法。最后提出了区间毕达哥拉斯犹豫模糊环境下的改进的ELECTRE II法,利用综合优势值对方案进行排序,并通过算例和比较分析验证了该方法的可行性和有效性。

融合NSGA-II和CSA的多目标车间调度

针对在灵活车间系统中调度作业和自动引导车(automated guide vehicle,AGV)的同时调度问题,考虑在有限多个AGV和加工机台的情况下,以最小化最大完工时间、单个AGV搬运消耗时间及所有AGV搬运总消耗时间为目标函数,设计融合NSGA-II(non-dominated sorting genetic algorithms)和克隆选择(clonal selection algorithm,CSA)的改进算法INGCSA来解决此类问题。采用工件、加工机台和AGV三部分编码;引入非支配排序和目标函数值大小排序后总得分进行种群分层,从而有效地保留优秀个体;针对克隆后的种群,对不同等级的种群采取不同的变异概率,并对染色体进行内部交换与均匀交叉混合交换的基因重组,有效地提高了种群的多样性与防止陷入局部最优。通过三组对比实验,验证了该算法在探索最优解时,具有运行时间短、稳定性高和收敛性好等优点。

基于改进NSGA-II的轨道交通接驳公交线路优化

为解决接驳公交线路规划不合理和时间安排不完善的问题,提出了基于改进NSGA-II算法的环形接驳公交线路优化方法。首先,结合双层规划理论,以乘客出行时间成本最小化、公交企业运营收益和接驳公交服务率最大化为目标函数,以接驳公交线路站点数、线路长度和发车频率作为约束条件构建上层模型,采用Logit模型构建了下层接驳客流分配模型;其次,运用Floyd算法对NSGA-II算法的初始化种群进行了优化,针对所提出的模型设计了模型求解流程;最后,以哈尔滨市轨道交通1号线医大一院轨道交通站为案例,运用笔者提出的多目标双层规划模型和算法进行求解,并与原NSGA-II算法和基于Logistic混沌映射的NSGA-II算法进行对比。研究结果表明:基于Floyd算法改进的NSGA-II算法在多目标双层规划模型求解时,收敛速度更快效果更好,求解结果可以在Pareto前沿得到多个相互非支配的最优解;不同解集对应目标函数值不同,但可以达到接驳公交网络整体效益最优,采用折衷最优解集表述求解结果。

营心宁胶囊辅助治疗对冠心病心力衰竭患者血管紧张肽II水平和心功能的影响

目的:观察营心宁胶囊辅助治疗对冠心病心力衰竭患者血管紧张肽II (AngII)水平和心功能的影响。方法:将128例患者分为两组,对照组64例,治疗组64例。对照组予常规治疗,治疗组患者在此基础上加用营心宁胶囊治疗,每次4粒,每日3次。治疗前及治疗8周后检测血浆AngII、脑钠肽(BNP),并行心脏彩色多普勒超声心动图测定左室射血分数(LVEF)、左室舒张末期内径(LVEDD)和每搏输出量(SV)。结果:治疗组和对照组总有效率分别为92.2%和89.1% (P > 0.01);显效率分别为43.8%,32.8% (P < 0.01)。两组治疗后患者的AngII、BNP、LVEF、LVEDD和SV均较治疗前明显改善(P < 0.01或P < 0.05),且治疗组患者的改善水平优于对照组(P < 0.01)。结论:营心宁胶囊能有效降低患者AngII水平,并对心功能有改善作用。

血管紧张素II对脓毒症休克大鼠心脏功能的影响

本研究拟通过盲肠结扎穿孔制备大鼠脓毒症模型,观察血管紧张素II对脓毒症休克(sepsis-shock)大鼠心脏功能的影响。方法 48只(Sprague-Dawley,SD)雄性大鼠随机分为6组(n=8):对照(control)组、假手术(sham)组、脓毒症休克(SS)组、去甲肾上腺素(NE)治疗组、血管紧张素II (ANGII)治疗组。采用盲肠结扎穿孔制备脓毒症休克动物模型。监测大鼠心率、血压变化。监测过程中大鼠如出现平均动脉压下降至65mmHg以下,立即给予0.9%生理盐水进行液体复苏,观察10分钟后如效果不佳,按照分组给予不同血管活性药物泵入。分别在造模后6,12,18,24小时抽血行心肌酶学指标检测,同时在该时段行超声观察大鼠心脏超声检查。于术后24小时留取心脏组织进行氧化因子指标测定,并进行心脏组织病理学观察。结果 与对照组和假手术组对比,脓毒症休克、去甲肾上腺素组、血管紧张素组平均动脉压下降明显,液体复苏效果欠佳,需要血管活性药物干预。与对照组和假手术组对比,脓毒症休克、去甲肾上腺素组、血管紧张素II组炎症反应、乳酸指标明显升高,具有统计学差异(P<0.05)。脓毒症休克组与对照组、假手术组相比,心脏左室射血分数(LVEF)明显下降,具有统计学差异(P<0.05),应用血管活性药物后,左室射血分数明显提高,血管紧张素II组射血分数提高与脓毒症组相比,具有显著统计学差异(P<0.01)。脓毒症休克组与对照组、假手术组相比,心肌酶学指标明显升高,应用去甲肾上腺素或血管紧张素II干预后,心肌酶学指标下降,与脓毒症组相比,具有统计学差异(P<0.05),血管紧张素II组改善更为明显(P<0.01)。结论 血管紧张素II可改善脓毒症休克对大鼠的心肌损害,对脓毒症休克大鼠心肌有一定的保护作用。

微波消解-金纳米星比色法快速检测婴幼儿食品中的Co(II)

文章建立了一种利用金纳米星粒子(GNSs)作为探针快速检测婴幼儿食品中Co(II)含量的方法,首先使用微波消解对检测样品进行前处理,然后基于钴离子引发类芬顿反应刻蚀GNSs导致粒子形貌及溶液发生改变的原理,通过比色法实现了对婴幼儿食品中Co(II)的高灵敏检测。结果表明:Co(II)浓度在100 pmol/L~20μmol/L范围内与GNSs溶液的局部表面等离子体共振峰(LSPR)吸收峰的波长差Δλ具有良好的线性关系(R2=0.995),对婴幼儿食品样品中Co(II)含量检测表现出良好的重现性和准确性(RSD<5%)。肉松中钴含量最高,其平均值高达0.3285 mg/kg,其次是鱼肠和奶酪棒,蔬菜泥和水果泥中钴含量较低。食品安全国家标准只规定了婴幼儿食品中铅、汞、砷、锡的限量值,而对于钴元素未设定限量值,本研究可为今后制定营养素或污染物限量标准提供参考依据,以提高婴幼儿食品的质量和安全水平。

表达Strep-tag II的重组塞内卡病毒的构建与鉴定

为构建表达Strep-tag II的重组塞内卡病毒(SVA),本研究在感染性cDNA克隆p SVA-I212V/S460L的基础上,采用重叠延伸PCR扩增Strep-tag II并采用无缝克隆法将其插入SVA VP1基因C端,构建感染性cDNA克隆,命名为p SVA-Strep,并采用双酶切和测序鉴定正确后,将p SVA-Strep转染BHK-21细胞拯救重组病毒,收集病变细胞上清,并将含有病毒的细胞上清和野生型SVA(SVA-WT)分别感染BHK-21细胞,以未感染病毒的BHK-21细胞作为阴性对照,感染后24 h分别以鼠源SVA VP2蛋白单克隆抗体(MAb)5D10(1∶1000)、鼠源Strep-tag II MAb(1∶2000)作为一抗,以FITC标记的山羊抗小鼠Ig G(1∶2000)为二抗,采用间接免疫荧光试验(IFA)对重组病毒鉴定。IFA结果显示,以鼠源SVA VP2蛋白MAb 5D10为一抗,SVA-WT和重组病毒感染的细胞均出现绿色荧光,以Strep-tag II MAb作为一抗时,仅有重组病毒感染的细胞出现绿色荧光,经SVA-WT感染的BHK-21细胞及阴性对照细胞均无绿色荧光,表明拯救了Strep-tag II标记的重组病毒,并将其命名为r SVA-Strep。将r SVA-Strep在BHK-21细胞中连续传10代,每隔2代采用引物VP1-F/R经PCR鉴定并对第10代重组病毒的VP1基因测序以鉴定r SVA-Strep的遗传稳定性。结果显示,每隔两代的重组病毒经PCR扩增后均出现约780 bp的目的条带,第10代重组病毒扩增的VP1基因测序结果显示Strep-tag II基因仍在重组病毒中,且无基因突变,表明r SVA-Strep的遗传稳定性较强;将SVA-WT和r SVA-Strep分别以MOI 0.01感染BHK-21细胞,在感染后4 h、8 h、12 h、24 h、36 h、48 h和72 h收获病毒测定病毒滴度并绘制生长曲线,结果显示在病毒感染36 h内r SVA-Strep和SVA-WT生长动力学基本一致,表明Strep-tag II的引入在病毒感染36 h内对SVA的复制基本无影响。采用0.2%甲醛充分灭活r SVA-Strep,并利用Strep-TactinRXT Purification纯化试剂盒纯化该灭活病毒,将r SVA-Strep灭活病毒上清加至Strep-Tactin亲和层析柱,分别用不同体积洗脱缓冲液依次洗脱病毒并通过western blot鉴定病毒的纯化效果。对纯化过程中不同洗脱液洗脱病毒的western blot结果显示,不同体积的洗脱液中E1、E2和E3均出现VP0和VP2两条带,且E1和E2的条带最明显,表明洗脱缓冲液的最佳洗脱体积约为2.2 CV;以上结果表明r SVA-Strep可通过Strep-Tactin亲和层析柱一步法纯化。本研究在SVA中插入Strep-tag II标签,为SVA灭活疫苗的快速纯化提供技术手段,也为其他病原的快速纯化方法的建立提供参考。

Effects of operating conditions on the performance degradation and anode microstructure evolution of anode-supported solid oxide fuel cells

Performance degradation shortens the life of solid oxide fuel cells in practical applications.Revealing the degradation mechanism is crucial for the continuous improvement of cell durability.In this work,the effects of cell operating conditions on the terminal voltage and anode microstructure of a Ni-yttria-stabilized zirconia anode-supported single cell were investigated.The microstructure of the anode active area near the electrolyte was characterized by laser optical microscopy and focused ion beam-scanning electron microscopy.Ni depletion at the anode/electrolyte interface region was observed after 100 h discharge tests.In addition,the long-term stability of the single cell was evaluated at 700℃for 3000 h.After an initial decline,the anode-supported single cell exhibits good durability with a voltage decay rate of 0.72%/kh and an electrode polarization resistance decay rate of 0.17%/kh.The main performance loss of the cell originates from the initial degradation.

NiCuCoMn电极材料的制备及其储锂性能研究

采用熔炼甩带和化学脱合金相结合的方法制备纳米多孔NiCuCoMn过渡金属氧化物(NiCuCoMn@TMOs),并通过热处理进一步制备R-NiCuCoMn@TMOs。通过X射线衍射(XRD)、扫描电子显微镜(SEM)、X射线光电子能谱(XPS)等测试对材料进行结构表征并对其进行电化学性能测试。作为锂离子电池负极材料,R-NiCuCoMn@TMOs在0.1 A/g的电流密度下,经过200次循环后具有394.9 mAh/g的高比容量,并且表现出97.53%的优异容量保持率。与热处理前相比,热处理后的材料具有更丰富的氧空位、更低的电荷转移电阻(38Ω)和更优异的倍率性能(在2 A/g的电流密度下,比容量为141.1 mAh/g)。其独特的纳米多孔结构提供了丰富的反应活性位点;不同半径、价态和反应电位的多种金属阳离子的协同效应使得该材料有很好的体积容忍度以适应脱嵌锂过程中的体积变化,表现出优异的电化学性能。此外,该电极材料原料储量丰富,价格低廉,易于实现批量化制备。该工作为设计多组元过渡金属氧化物负极材料提供了新的思路。

Sesame Husk as Adsorbent for Copper(II) Ions Removal from Aqueous Solution

In this study, the adsorption behavior of copper(II) ions from aqueous solutions onto sesame husk (SH) was investigated. The effect of different parameters such as pH, contact time, adsorbent dosage, adsorbate concentration, temperature and agitation speed was studied. Thermodynamic parameters, equilibrium isotherms and kinetic data have been evaluated. The functional groups and surface morphology of SH adsorbent were characterized by FTIR and SEM. Adsorption equilibrium isotherms were expressed by Langmuir, Freundlich and Dubinin-Radushkevich (D-R) adsorption models and it was found that Langmuir adsorption model fits the experimental data better than Freundlich and D-R models. The adsorption can be best described by the pseudo second-order kinetic model.

Atomic Absorption and Vibrational Spectral Magnetic Studies on the Removal of Cu(II) and Co(II) Ions Using Synthetic Nano Adsorbent Fe₃O₄

Adsorption of Cu(II) and Co(II) from aqueous solutions on synthetic nano Fe3O4 has been studied. The effect of experimental parameters such as initial concentration of the metal ions, adsorbent dosage, contact time and pH has been investigated. Optimum removal efficiency of Cu(II) ion was found to be 97.8% with the dose rate of 1.07 g/L in 60 minutes at pH = 5.5 and for Co(II) ion, it was found to be 99.2% with the dose rate of2.57 g/L in 10 minutes at pH = 5.4. The removal of Co(II) ions require only 10 minutes with the efficient removal of 99.2%, whereas Cu(II) ions require 60 minutes with the maximum removal of 97.8%. In order to understand the effective removal of Cu(II) and Co(II) ions on Fe3O4, room temperature magnetic measurement was carried out using Vibrational Spectrum Magnetometer (VSM), before and after adsorption with a maximum applied magnetic field of 20,000 G.

Environmentally Friendly Room Temperature Synthesis of 1-Tetralone over Layered Double Hydroxide-Hosted Sulphonato-Salen-Nickel(II) Complex

1-Tetralone, a useful synthetic intermediate in the manufacture of pharmaceuticals, agrochemicals and dyes, can be prepared by liquid phase catalytic oxidation of tetralin. Selective oxidation of tetralin to 1-tetralone is still a big challenge with low-temperature processes using environmentally friendly routes even after decades of research. Herein, we demonstrate room-temperature oxidation of tetralin to 1-tetralone over layered double hydroxide-hosted sulphonato-salen-nickel(II) complex, LDH-[Ni-salen]. The layered double hydroxide-hosted sulphonato-salen-nickel(II) compound was characterized by powder X-ray diffraction, Fourier transform infrared spectrometer (FTIR), UV-Visible diffuse reflectance spectra, scanning electron microscopy (SEM) and elemental analysis. The theoretical calculations of free sulphonato-salen-nickel(II) complex using Density Functional Theory/CAM-B3LYP at the 6-311++ G(d,p) level of theory were also used to determine the orientation of the Ni-salen compound within the layered structure. The immobilized compound, LDH-[Ni-salen] was found to be an effective reusable catalyst for the oxidation of tetralin to 1-tetralone using a combination of trimethylacetaldehyde and molecular oxygen (14.5 psi) and at 25&deg;C. At 45.5% conversion, tetralin was converted to 1-tetralone with 77.2% selectivity at room temperature and atmospheric pressure after 24 h. The catalyst recycles test and hot filtration experiment showed that oxidation proceeded through Ni(II) sites in LDH-[Ni-salen]. The catalysts were reused several times without losing their catalytic activity and selectivity. The present results may provide a convenient strategy for the preparation of 1-tetralone using layered double hydroxide-based heterogeneous catalyst at ambient temperature for industrial application in near future.

Modeling of Fixed Bed Adsorption Column Parameters of Iron(II) Removal Using Ferrihydrite Coated Brick

Fixed-bed operating experimental column conditions were studied to evaluate the performance of brick from Bangui Region (in Central African Republic), coated with iron oxyhydroxide (ferrihydrite) for the removal of iron(II) from aqueous solution. The prediction of theoretical breakthrough profiles using Bohart and Adams sorption model was employed to achieve characteristic parameters such as depth of exchange zone, time required for exchange zone to move vertically, moving rate for the exchange zone and adsorption capacity useful for fixed-bed column reactor was investigated under varying operating conditions. The effects of bed depth and flow rate on iron(II) adsorption were studied. Our finding revealed that the Brick from Bangui Region (in Central African Republic), coated with ferrihydrite was a very efficient media for the removal of Fe(II) ions from water. The experimental data showed that the depth and the moving rate (10.3 ± 0.6 cm) and (0.208 ± 0.006 cm/min) respectively of the exchange zone (adsorption zone) were independent of variability of the height of the adsorbent bed column, however the variations of the flow rate affect the moving rate of the exchange zone. The bed depth service time (BDST) model was used and permitted us to predict the service times of columns operated at various flow rates and bed depths and these predicted values were compared with the experimental values.