Experiments of a prototype wind-driven reverse osmosis desalination system with feedback control

A prototype wind-powered reverse osmosis desalination system was constructed and tested on Coconut Island off the northern coast of Oahu, Hawaii, for brackish water desalination. The system has four major subsystems: a multi-vaned windmill/pump, a flow/pressure stabilizer, a reverse osmosis module, and a control mechanism. The feedback control mechanism, developed by this study, allowed this prototype system to be operated satisfactorily under mild ambient wind of 5 m/s or less. No auxiliary power source was needed. The system operational data showed that at an average wind speed of 5 m/s, brackish feedwater at a total dissolved solids concentration of 3000 mg/1 and at a flow rate of 13 1/min could be processed by this system. The average rejection rate of this prototype system was 97% and the average recovery ratio was 20%. The energy efficiency of the system was measured at 3 5%, which is comparable to the typical energy efficiency of well-operated multi-vaned windmills. Generally, the system's energy efficiency decreases as wind speed increases.     

Dishwashing performance of mixed palm stearin sulfonated methyl esters and polyoxyethylene sorbitan esters

The detergency profiles of sodium salt α-sulfonated methyl esters derived from palm stearin (α-SMEPS) and polyoxyethylene (20) sorbitan monoesters (POESE) in mixed micelle systems were evaluated as a function of the weight ratios of α-SMEPS/POESE [polyoxyethylene (20) sorbitan monolaurate (12), polyoxyethylene (20) sorbitan monostearate (18∶0), and polyoxyethylene (20) sorbitan monooleate (18∶1)] at different water hardness values (5.12, 51.2, and 512.0 ppm CaCO₃) and temperatures (20, 30, 45, and 65°C), respectively. All the mixtures of α-SMEPS/POESE (12, 18∶0, and 18∶1) systems exhibited a synergistic effect at 65°C in the absence of hardness. This was evaluated by measuring the percentage of soil removed. The systems showed an increase in detergency with both the temperature and water hardness. Maximal detergency was observed with 5.12 ppm CaCO₃ in the mixed surfactant solution.     

Synthesis and water absorbency of crosslinked superabsorbent polymers

A series of novel copolymer superabsorbents based on monomer acrylamide (AM), potassium methacrylate (KMA), and 2‐hydroxyethyl methacrylate (HEMA) were prepared by copolymerization using ammonium persulfate (APS) as an initiator and N,N‐methylenebisacrylamide (MBA) as a crosslinking agent. The synthetic variables (the monomer concentration, crosslinker concentration, and initiator concentration) were also studied. The experimental results of superabsorbent polymers (SAPs) show a better absorbency in both water and NaCl solutions. The copolymers were characterized by IR spectroscopy. The water retention in the soil was enhanced using the above superabsorbents. The use of SAPs for the growth of groundnut plants was also investigated. SAPs can be considered for water‐managing materials for agriculture and horticulture purposes in desert and drought‐prone areas. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1795–1801, 2002     

裂解气压缩机级间注水技术的应用

介绍了裂解气压缩机由注洗油改为注水情况，进而得出结论：改注水降温效果明显，压缩机工作效能可得到有效保障。     

Pervaporation study of water and tert‐butanol mixtures

The permeation behavior of water/tert‐butanol mixture through Sulzer Pervap2510 hydrophilic poly(vinyl alcohol) membranes was investigated and the effects of feed composition and temperature on separation efficiency of the membranes were studied. The pervaporation experiments were carried out with feed water content varying from 0 to 20 wt % according to the existing industrial needs and with the feed temperature from 60 to 100°C. Over this range, both water flux and separation factor increased with increasing water content and feed temperature. These phenomena may be attributed to (1) the strong interaction between water and the membrane, (2) the decoupling effect of the permeants and the membrane at elevated temperatures, and (3) the steric hindrance effect of branch chain alcohol. The permeability ratio (the ideal separation factor) of water to tert‐butanol across the membrane was calculated and found to follow the same relationship with increasing temperature and water content. Both flux and separation factor obtained from the Pervap2510 membrane in this study were much higher than previous reported values, possible causes for which were analyzed. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 4082–4090, 2004     

Preparation of water‐soluble syndiotacticity‐rich high molecular weight poly(vinyl alcohol) microfibrillar fibers using copolymerization of vinyl pivalate and vinyl acetate and saponification

Water‐soluble high molecular weight (HMW) syndiotactic poly(vinyl alcohol) (s‐PVA) microfibrillar fibers were prepared by the saponification with various conditions such as amount of alkali solution, saponification temperature, and saponification concentration from copoly(vinyl pivalate (VPi)/vinyl acetate (VAc)) copolymerized using various VPi/VAc feed ratios. To produce s‐PVA microbrillar fibers having various water‐soluble temperatures for many industrial applications, the intrinsic viscosities, syndiotactic diad (S‐diad) contents, and degrees of saponification (DS)s of PVAs were finely controlled to 1.2–3.6 dL/g, 56.3–58.3%, and 91.4–98.3%, respectively. Through a series of experiments, it was found that the amount of alkali may alter the structure of the saponified polymers, primarily the DS, and the structural variation changes viscosity. That is, intrinsic viscosity was sharply decreased as the amount of alkali solution was increased. DS was increased with an increase in the amount of alkali solution. S‐diad content was increased with an increase in the VPi content. HMW s‐PVA microfibrillar fibers having S‐diad content of 56.3–58.3% prepared by the saponification of copoly(VPi/VAc) were completely soluble in water at 100°C. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1482–1487, 2003     

Water uptake and mechanical characteristics of natural filler–polypropylene composites

Water uptake characteristics and some mechanical properties of polypropylene composites containing three types of natural fillers, purified α‐cellulose, wastepaper fibers, and wood flour were studied. The fiber contents were 15, 25, and 35% by weight. Two percent maleic anhydride polypropylene (MAPP) was also added to the mix, as the compatibilizer agent. Mixing process was performed in a Brabender Plasticorder until a constant torque was reached. Composites made out of these combinations were then pressed in a laboratory press and ASTM standard test specimens were cut out of the sheets. Water absorption and tensile tests were performed on these specimens. The results showed a significant difference between the various filler types regarding water uptake. Water uptake also increased by the increase in filler content. Tensile strength and elongation at break in composites declined when compared with pure polypropylene, but their modulus of elasticity increased. Among the three types of fillers, no significant discrepancies were observed in terms of improving mechanical properties in composites. Filler content increase had no drastic effect regarding strength improvement. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 941–946, 2003     

用木质素磺酸铵作标准化试剂提高单偶氮、双偶氮酸性染料的冷水溶解度的方法

一般的酸性染料溶解度较小,而本文所介绍的单或双偶氮酸性染料,实际上是以碱金属盐的形式存在,由于加入了（按重量计）80％～30％的木质素磺酸铵,改善了室温的冷水溶解度。木质素磺酸铵既作为标准化试剂,用来调节高强度染料到稳定的商品染料,同时又能提高染料在室温时冷水溶解度。     

水射流清洗技术在石油行业中的应用

简要介绍了水射流清洗机理,对水射流清洗钻杆、油管、油井解堵技术进行了详细的分析,介绍了几种技术的技术特点,操作工具和应用情况。水射流清洗技术具有清洁、节能、方便快捷、成本低等优点,在清洗行业中将发挥重要作用。     

Air sampling of volatile sex pheromone components in a closed jar

A cotton wool plug, used as the source for pheromone release, was placed in closed 1-quart Mason jars, either at the mouth or at the rear of the jar. Air sampling of the two components of the sex pheromone (total 2.2 mg at the source) of the almond moth (Ephestia cautella) female showed that the saturation period near the source in still air was 20–22 hr and that far from the source was 40–50 hr, reaching a level of less than 1 ng/ml air. The ratio between the components (Z,E)-9,12-tetradecadienyl acetate, designated D, and (Z)-9-tetradecenyl acetate designated M, in the air was close to the original ratio for both sampling sites, albeit somewhat richer in the more volatile (Z)-9-tetradecenyl acetate (source 77.023.0 DM, air 73.0– 74.327.0–25.7; source 80.119.9, air 77.622.4; source 25.174.9, air 23.976. 1 DM). The total amount of pheromone per milliliter of air was two to three times larger near the source than far from it at the early stages of the evaporation and saturation process. When the amount of pheromone applied to the source was tripled (7 mg), the amount far from the source was almost tripled, or the saturation time was cut by factor of two to three.