Hydrate-based pre-combustion carbon dioxide capture process in the system with tetra-n-butyl ammonium bromide solution in the presence of cyclopentane

Effects of 0.29 mol% tetra-n-butyl ammonium bromide (TBAB) solution in conjunction with cyclopentane (CP) on the hydrate-based pre-combustion CO₂ capture are investigated by the measurements of the gas uptakes, CO₂ separation efficiencies and induction time of the hydrate formation at the different temperature-pressure conditions. The results show that the volume of the TBAB has an effect on the CO₂ separation and the induction time, and the addition of the CP into the TBAB solution remarkably enhances the CO₂ separation and shortens the induction time. The system with the CP/TBAB solution volume ratio of 5 vol% and TBAB solution/reactor effective volume ratio of 0.54 is optimum to obtain the largest gas uptake and the highest CO₂ separation efficiency at 274.65 K and 4.0 MPa. Compared to the results with tetrahydrofuran (THF) as an additive [1], the gas uptake is enhanced by at least 2 times and the induction time is shortened at least 10 times at the similar temperature-pressure condition. In addition, the CO₂ concentration in the decomposed gas from the hydrate slurry phase reaches approximately 93 mol% after the first-stage separation at 274.65 K and 2.5 MPa. The gas uptakes of more than 80 mol% are obtained after 400 s at the temperature range of 274.65-277.65 K and the pressure range of 2.5-4.5 MPa.     

The interaction of sesamol with DNA and cytotoxicity,apoptosis, and localization in HepG2 cells

Sesamol, a nutritional antioxidant phenolic compound present in sesame seed, has a potential therapeutic molecule effect against cancers. In this study, the interaction between sesamol and DNA was investigated by employing ultraviolet/visible (UV/Vis), fluorescence, circular dichroism (CD), Fourier transform infrared spectroscopy (FT-IR), and molecular modeling. The fluorescence analysis indicated that the fluorescence quenching mechanism of sesamol by calf thymus DNA (ctDNA) occurred through static quenching. The UV/Vis, CD, FT-IR spectra and molecular docking results implied that the primary binding mode was minor groove binding. Furthermore, the intracellular interaction of sesamol with DNA and its bioactivity effect were explored. The cell activity results demonstrated that sesamol induced hepatic cell line (HepG2) death. The acridine orange (AO)/ethidium bromide (EB) staining assay and DNA fragmentation confirmed that sesamol could efficiently induce the apoptosis of HepG2 cells. Moreover, addition of sesamol to HepG2 cells resulted in nuclear localization, as visualized by confocal microscopy.     

四丁基溴化铵水合物储存氢气的研究

利用高压搅拌式水合物实验装置,进行了四丁基溴化铵(TBAB)水合物储氢的研究。在恒容条件下,考察了水浴温度、初始压力对水合物储氢特性的影响,并比较了TBAB水合物和四氢呋喃(THF)水合物的储氢性能。实验结果表明,在初始压力7.2 MPa、x(TBAB)=0.6%的条件下,水浴温度越低,生成水合物的诱导时间越短,储氢密度越大,水浴温度为0.5℃时储氢密度最大(为0.095%);在水浴温度0.5℃、x(TBAB)=0.6%的条件下,初始压力越大,生成水合物的诱导时间越短,储氢密度越大,在初始压力为8.4 MPa时储氢密度最大(为0.109%);在水浴温度为0.5℃、初始压力7.2 MPa的条件下,THF水合物的储氢密度仅为0.014%,远低于TBAB水合物的储氢密度(0.095%),TBAB水合物的储氢性能更好。     

十六烷基三甲基溴化铵和FC911对砂岩表面润湿性的影响

分别用十六烷基三甲基溴化铵（CTAB）和阳离子氟碳型表面活性剂FC911处理石英砂,然后用Washburn法测定处理后石英砂对水和油的接触角,研究两种阳离子表面活性剂对砂岩表面润湿性的影响。实验结果表明随着处理液CTAB浓度从0增至10000 mg/L,石英砂水相接触角由0°增至89°,再减至66°,表面从水湿变为中性润湿,再变为弱水湿。FC911浓度为10～1000 mg/L时,水相接触角由〉90°逐渐减小至89.7°;油相接触角由15.3°逐渐增至〉90°。石英砂表面由强油湿变为弱油湿后再变为中间气湿。较低浓度的FC911即可将石英砂表面转变为既疏水又疏油的中间气湿,最佳使用浓度为200 mg/L。     

粉唑醇的合成

粉唑醇是用于植物叶片和穗的广谱杀菌剂,对谷物白粉病、云形病、叶斑病和锈病都有效。本文以邻氟溴苯为原料经格氏反应合成1-(2-氟苯基)-1-(4-氟苯基)-2-氯乙醇,然后与1,2,4-三唑钠盐反应得到标题化合物。总收率达59%,含量94.5%。     

One-pot lithium bromide-catalyzed reaction of polyoxyethylene diglycidyl ether with carbon disulfide: synthesis of new polyoxyethylene epoxyoxathiolane-2-thione

A simple and highly efficient regio- and chemio-specific synthesis of polyoxyethylene epoxyoxathiolan-2-thione was realized from a one-pot reaction of polyoxyethylene diglycidyl ether and carbon disulfide using lithium bromide as a catalyst. The unsymmetrical obtained products were fully characterized by ¹H, ¹³C NMR and high-resolution mass spectra data.     

Biology and integrated pest management of Tyrophagus putrescentiae (Schrank) infesting dry cured hams

The biology and physiology of Tyrophagus putrescentiae (Schrank) (Sarcoptiformes: Acaridae), also known as the ham, cheese or mold mite, is reviewed along with methods that have been evaluated for managing and controlling this pest. This review was conducted because the ham mite is an important target pest of the dry cured ham industry. Methyl bromide has been historically used to control mite infestations, but is now banned or being phased out of use in most countries because it is an ozone-depleting substance. Only commercially available stockpiles and quarantine and pre-shipment methyl bromide are available for use in countries that require such action. This review compares the effectiveness and feasibility of recently investigated methods to control mite infestations on dry cured ham and to discuss integrated pest management plans for ham mites. The review also proposes methods for conducting a prevention and monitoring-based integrated pest management program that relies on definitive mitigation such as fumigation only when mite numbers exceed a critical action threshold.     

Performance of microwave synthesized dual solvent dope solution and lithium bromide additives on poly(ethersulfone) membranes

BACKGROUND: Generally the fabrication of polymeric membranes is a complicated and expensive process since it involves several steps. The preliminary preparation steps involve polymer drying and dissolution and is very time consuming and expensive. Currently, conventional electrothermal heating (CEH) is used to dissolve polyethersulfone in an aprotic solvent for membrane fabrication. Usually CEH requires 6 to 8 h at temperatures of 80 to 95 °C. This paper reports the fabrication and characterization of polyethersulfone (PES) asymmetric ultrafiltration membrane made from microwave (MW) synthesis casting solution consisting of various compositions of double solvents and lithium bromide (LiBr) additive. RESULTS: Homogeneous dual solvent dope solutions prepared via microware irradiation took only 1 h instead of the 7 h when prepared using CEH. The results also revealed that the membrane permeation and rejection rates, pore size and porosity were dependent on the ratio of LiBr to acetone. Membranes with LiBr kept at 2 and 3 wt% exhibited both high rejection and permeation rates with minimum pore sizes of 1.067 and 1.214 nm respectively. The presence of LiBr and the occurrence of chain scission were elucidated using Fourier transform infrared (FTIR) spectroscopy while its hydrophilic property was confirmed by water absorption and contact angle measurements. CONCLUSIONS: It was concluded that the microwave technique is capable of producing 1 L membrane solutions in less than 1 h. The membranes prepared from the microwave solutions show good rejection and permeation rates. Copyright © 2011 Society of Chemical Industry     

Physico-chemical characteristics of nano-organo bentonite prepared using different organo-modifiers

Different types of nano-organo bentonite (NOB) were prepared from the Egyptian Bentonite (EB). EB was characterized by energy dispersive X-ray EDX. It was purified from different impurities using a conventional method via the treatment with HCl and distilled water. The modification of the clay was carried out using different types of organo-modifiers namely; hexadecyl trimethyl ammonium bromide (HTAB), 3-aminopropyltriethoxysilane (Silane), octadecylamine (ODA), and dodecylamine (DDA). The cation exchange capacity (CEC) was measured for pristine bentonite after and before modification. The NB was characterized by FTIR, XRD, TEM, and TGA techniques. The obtained results indicated that variation of the interlayer space gallery was effected by the type of the penetrator used.     

Interpolymer radical coupling: A toolbox complementary to controlled radical polymerization

The current review focuses on the relevance and practical benefit of interpolymer radical coupling methods. The latter are developing rapidly and constitute a perfectly complementary macromolecular engineering toolbox to the controlled radical polymerization techniques (CRP). Indeed, all structures formed by CRP are likely to be prone to radical coupling reactions, which multiply the available synthetic possibilities. Basically, the coupling systems can be divided in two main categories. The first one, including the atom transfer radical coupling (ATRC), silane radical atom abstraction (SRAA) and cobalt-mediated radical coupling (CMRC), relies on the recombination of macroradicals produced from a dormant species. The second one, including atom transfer nitroxide radical coupling (ATNRC), single electron transfer nitroxide radical coupling (SETNRC), enhanced spin capturing polymerization (ESCP) and nitrone/nitroso mediated radical coupling (NMRC), makes use of a radical scavenger in order to promote the conjugation of the polymer chains. More than a compilation of macromolecular engineering achievements, the present review additionally aims to emphasize the particularities, synthetic potential and present limitations of each system.