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.     

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.     

Modeling and performance analysis of an absorption chiller with a microchannel membrane‐based absorber using LiBr‐H2O,LiCl‐H2O,and LiNO3‐NH3

In order to develop compact absorption refrigeration cycles driven by low heat sources, the simulated performance of a microchannel absorber of 5‐cm length and 9.5 cm³ in volume provided with a porous membrane is presented for 3 different solution‐refrigerant pairs: LiBr‐H₂O, LiCl‐H₂O, and LiNO₃‐NH₃. The high absorption rates calculated for the 3 solutions lead to large cooling effect to absorber volume ratios: 625 kW/m³ for the LiNO₃‐NH₃, 552 kW/m³ for the LiBr‐H₂O, and 318 kW/m³ for the LiCl‐H₂O solutions given the studied geometry. The performance of a complete absorption system is also analyzed varying the solution concentration, condensation temperature, and desorption temperature. The LiNO₃‐NH₃ and the LiBr‐H₂O solutions provide the largest cooling effects. The LiNO₃‐NH₃ can work at a lower temperature of the heating source, in comparison with the one needed in a LiBr‐H₂O system. The lowest cooling effect and coefficient of performance are found for the LiCl‐H₂O solution, but this mixture allows the use of lower temperature heating sources (below 70°C). These results can be used for the selection of the most suitable solution for a given cooling duty, depending on the available heat source and condensation temperature.     

Effects of temperature,relative humidity,and protective netting on Tyrophagus putrescentiae (schrank) (sarcoptiformes: Acaridae) infestation,fungal growth,and product quality of cave-aged Cheddar cheese

Research was conducted to evaluate the effects of using food-grade ingredients on cave aged Cheddar cheese as either a surface coating or in nets to prevent infestation by Tyrophagus putrescentiae growth at different environmental conditions. Food grade coating formulations with 1) xanthan gum and propylene glycol (XG+PG) and 2) carrageenan, propylene glycol alginate, and PG (CG+PGA+PG) were made and infused into nets. Jars with cave aged Cheddar cheese cubes that were inoculated with 20 mites were stored in an environmental chamber for 14 d at temperature and relative humidity (RH) combinations of 10, 15, and 20 °C and 75 ± 2 and 85 ± 2% RH. When averaged over RH, mite counts were fewer on control cheese cubes at 10 °C when compared to 15 °C and 20 °C, regardless of whether nets were used or not. However, mites were able to reproduce on untreated cheese cubes at all temperatures. The CG+PGA+PG and XG+PG coatings and nets controlled mite reproduction, as evidenced by harboring less than the initial inoculation level of 20 mites. Sensory results indicated that CG+PGA+PG and XG+PG coated Cheddar cheese at 10 °C and 75% RH and netted Cheddar cheese at 10 or 15 °C and 75% RH did not differ (P > 0.05) from the control with respect to sensory attributes. The treatments at 15 °C and 85% RH and 20 °C caused the cheese to be softer and more bitter than control cheese. In conclusion, the CG+PGA+ 40% PG and XG+40% PG treatments of both coatings and nets inhibited the growth of mites, and the use of nets lessened the impact of food grade coatings on the sensory properties of the Cheddar cheese.     

钴与邻硝基苯基荧光酮、CPB、乳化剂OP的显色反应

本文研究了钴与邻硝基苯基荧光酮、CPB、乳化剂OP多元配合物的显色反应。在pHl0.5时,其最大吸收波长在640nm,摩尔吸光系数为1.59×10~5,钴量在0～14μg/25ml范围内符合比尔定律。应用于矿石中微量钴的测定,结果满意。     

十六烷基三甲基溴化铵修饰的羧基化单壁碳纳米管的细胞毒性

采用十六烷基三甲基溴化铵（CTAB）作为表面活性剂修饰羧基化的单壁碳纳米管（SWNT-COOH/CTAB）,并对原始单壁碳纳米管（SWNTs）与羧基化修饰的单壁碳纳米管（SWNT-COOH）进行材料学特征比较。通过细胞活力和细胞凋亡实验对SWNTs、SWNT-COOH和SWNT-COOH/CTAB的细胞毒性进行比较。结果表明,羧基化修饰的单壁碳纳米管比原始单壁碳纳米管的毒性小,单壁碳纳米管经羧基化后其毒性降低;浓度及时间曲线显示SWNT-COOH/CTAB的毒性与表面活性剂CTAB相关,CTAB和 SWNT-COOH/CTAB的细胞毒性在低浓度范围内（0.5-25μg/mL）是可接受的。十六烷基三甲基溴化铵修饰的羧基化单壁碳纳米管在低浓度范围（0.5-25μg/mL）内可以较安全地用于生物医学领域。     

有机改性蒙脱土吸附黄曲霉毒素B1能力的研究

利用十八烷基三甲基溴化铵(OTMAB)作为有机改性剂对钠基蒙脱土(Na-MMT)进行改性,以提高对黄曲霉毒素B1(AFB1)的吸附能力。改性后的钠基蒙脱土利用X-射线衍射(XRD)、傅立叶变换红外光谱(FTIR)、扫描电镜(SEM)及热失重分析(TGA)等方法对其结构特性进行研究。结果表明,改性剂OTMAB插入到钠基蒙脱土的夹层内并扩大了其夹层间距(d_(0.01)),增大了其比表面积。改性蒙脱土对AFB1的吸附等温线符合Langmuir数学模型。有机改性Na-MMT对AFB1的最大吸附量(q_(max))为34.25 mg/g,Langmuir吸附常数(k)为3.65L/mg,均高于未改性的Na-MMT(q_(max)=28.74mg/g和k=2.37L/mg),说明有机改性能够有效提高Na-MMT对AFB1的吸附能力。     

3-甲硫基-1-丙醇的合成研究

研究了以 3 氯 1 丙醇和甲硫醇钠为原料 ,在相转移催化剂四甲基溴化铵的作用下 ,在 0℃下反应 1h ,然后升温至 30℃ ,并在此温度下反应 0 .5h ,合成了 3 甲硫基 1 丙醇 ,并用气相色谱、红外光谱和气质联用对其结构进行了确定。该方法工艺简单 ,条件温和 ,反应时间短 ,易于工业化 ,环境污染少 ,也适应于合成其他甲硫基化合物。     

3，4-亚甲二氧基苯乙胺的合成新方法

以胡椒胺为原料,通过Sandmeyer反应制得3,4-亚甲二氧基溴苯(收率75.0%),再经Grignard反应(收率74.8%)、酯化反应(收率94.0%)和Gabriel反应(收率63.0%)制备出3,4-亚甲二氧基苯乙胺,并通过红外光谱和色谱-质谱联用确定了目标产物的结构。讨论温度对各步反应的影响,确定了最佳反应条件。