生物质油-柴油超声波乳化液燃烧性能研究

利用自行研发的槽式可变频率可控波形超声波乳化仪,将一定体积比的生物质油与0^#柴油在加入少量乳化剂(Span 80、Tween 80)的情况下进行超声乳化,制取了可直接用作柴油机燃料的生物油-柴油超声波乳化液,并进行了柴油机应用台架试验,试验结果表明:与柴油相比,生物质油-柴油超声波乳化液的NO_X排放大幅度的降低,其中小负荷时NO_X排放较柴油低 50% 左右;不同配比的乳化液(B10、B15、B20)炭烟排放均比0^#柴油排放低,烟度排放值K小于1,远低于国家标准(K<3)。     

生物质裂解油在柴油中乳化的研究

以乳化液稳定性为评价指标,研究了复配乳化剂、助乳化剂、助乳化剂与复配乳化剂质量比[m(C)m/(T)]及生物质裂解油在乳化液中质量分数的选择,并考察了HLB值、乳化温度、乳化时间、乳化方式、搅拌方式对乳化液稳定性的影响。实验结果表明:采用质量分数1.7%的T-85和乳化剂A的复配乳化剂,m(C)m/(T)为0.05的正辛醇为助乳化剂,在HLB值为8、乳化温度为20~40℃的条件下,将质量分数5%的生物质裂解油在柴油中高速乳化5m in,其中,乳化方式为T-85溶于生物质裂解油,乳化剂A溶于柴油,边搅拌柴油边加入生物质裂解油,再加入助乳化剂,乳化液的稳定性较好,稳定时间可达20 d。     

超声制备甲醇乳化柴油影响因素的响应面法优化

采用超声制备甲醇乳化柴油,通过正交实验筛选乳化剂配比;采用高速分散器预乳化和超声波装置深度乳化,考察了超声时间和功率、甲醇和乳化剂含量等因素对甲醇乳化柴油稳定性的影响;在单因素实验基础上,基于Box-Behnken实验设计,利用Design-Expert数据分析软件的响应面分析法优化了工艺条件,并建立了以甲醇乳化柴油稳定时间为响应值的数学模型.结果表明,适宜的乳化剂质量比为油酸:Span-80:OP-10:Tween-80:羧甲基纤维素钠=14:5:2:1:5,HLB值为4.48.各因素对甲醇乳化柴油稳定性的影响程度为乳化剂含量?超声功率?甲醇含量?超声时间,交互作用程度为超声时间和功率?超声功率和乳化剂含量?甲醇含量和乳化剂含量?超声时间和乳化剂含量?超声时间和甲醇含量;最优工艺条件为超声时间20 min、超声功率220 W、甲醇含量10%、乳化剂含量5%.在最优条件下进行实验,稳定时间实验值与预测值的相对偏差为2.69%,表明响应面拟合方程可用于超声制备甲醇乳化柴油稳定性的预测和最优工艺条件的确定.     

超声制备甲醇柴油乳液及其稳定性研究

采用Tween 80,Span 80,Tween 20,油酸和十二烷基磺酸钠复配作为乳化剂,利用高速分散器和超声波装置作为预乳化和深度乳化装置制备甲醇柴油乳液。研究了超声参数(声强和作用时间)、乳化剂及甲醇用量等对甲醇柴油乳液稳定性的影响,得出适宜的操作条件为:复配乳化剂HLB值为5.1,复配乳化剂质量分数为3%,甲醇体积分数为15%,预乳化时间为5 min,转速为5×2 800 r/min,超声乳化时间为15 min,超声作用功率为352 W。     

影响冷轧油乳液稳定性工艺因素的研究

为确定某种特定的冷轧油乳化液配制时的工艺条件,研究了复配乳化剂种类、用量、乳化温度、乳化时间等参数对该乳液稳定性的影响规律。研究表明：将醚类与酯类的非离子乳化剂进行乳化,温度50℃,复配乳化剂用量占总乳化液的0.56%,油水体积比1∶19,搅拌时间50min下制得的冷轧油乳化液的稳定性符合我国现行乳化液稳定性行业标准。     

生物质热解油/柴油乳化效果评价方法及影响因素

采用微观和宏观分析相结合的方法,评价稻壳热解油和柴油乳化效果,宏观上以热解油乳化比例为评价依据,微观上以乳化液中热解油液滴的平均粒径和数密度为评价依据,重点研究了乳化剂种类、亲水亲油平衡指数（hydrophilic-lipophilic balance,HLB）、乳化液静置时间、乳化温度、热解油质量分数、乳化剂用量等因素对热解油和柴油乳化效果的影响。研究结果表明：微观和宏观分析法对乳化效果变化规律的评价结果基本一致,评价方法具有较高的准确性。与司班80-吐温80复配乳化剂相比,Atlox 4194-DP 2206复配乳化剂对热解油和柴油混合液的乳化效果更好,且乳化剂的最佳HLB值为4.82。热解油液滴平均粒径和液滴数密度在静置第1天内变化较为明显,在静置时间超过3天后基本保持不变。静置时间超过1天后,乳化温度对乳化液的稳定性和乳化效果没有影响。随热解油质量分数或乳化剂用量的增加,热解油乳化效果先增加后降低,热解油的质量分数范围应在10%~20%间,且质量分数为10%时,热解油乳化效果最好,热解油乳化比例可保持在90%以上;乳化剂与热解油比例的范围应在0.25~0.5,且比例为0.5左右时,乳化效果最佳,热解油乳化比例可稳定在85%以上。     

超声微乳捕收剂的制备及煤泥浮选性能研究

为了提高烃油捕收剂在水中的分散性,采用微乳化技术制备柴油微乳捕收剂,并通过超声波强化分散效果,考查了超声频率、超声功率和超声时间等因素对柴油微乳化效果的影响,获得了最佳超声作用参数,并进行了不同捕收剂的煤泥浮选试验。结果表明,超声频率20 k Hz、超声功率400 W、超声作用时间15 min为最佳超声条件,在此条件下制备的超声微乳捕收剂ULY中油滴平均粒径为16.39 nm。煤泥浮选试验表明,柴油、微乳捕收剂LY和ULY在用量900、800和750 g/t条件下可获得的最佳浮选完善指标,分别为58.58%、62.87%和62.25%,说明柴油经微乳化后,可在较低用量条件下获得更好的综合分选效果,且LY和ULY节油率分别达到72.22%和73.96%。在分选指标相近的情况下,ULY用量比LY减少50 g/t,说明超声微乳能形成更加细小的油滴,有利于提高分选效率,降低捕收剂耗量。     

影响水包油型乳化液稳定性的因素研究

研究了影响水包油型乳化液稳定性的因素:乳化剂种类、乳化剂质量、剪切乳化方式、剪切乳化时间、剪切乳化速率。通过选取油滴平均粒径(dn)和油浓度(c)作为乳化液稳定性评价指标,进行实验对比。结果表明,乳化剂为1 g十二烷基苯磺酸钠、高速剪切乳化机转速为6 000 r/min、乳化时间为10 min时形成的乳化液较为稳定。且在乳化剂、剪切乳化方式一定的情况下,随剪切乳化速率的增大、乳化时间的加长,油滴粒径越小,油浓度越大,油滴分布越均匀,乳状液越稳定。     

影响水包油型乳化液稳定性的因素研究

研究了影响水包油型乳化液稳定性的因素:乳化剂种类、乳化剂质量、剪切乳化方式、剪切乳化时间、剪切乳化速率。通过选取油滴平均粒径(dn)和油浓度(c)作为乳化液稳定性评价指标,进行实验对比。结果表明,乳化剂为1 g十二烷基苯磺酸钠、高速剪切乳化机转速为6 000 r/min、乳化时间为10 min时形成的乳化液较为稳定。且在乳化剂、剪切乳化方式一定的情况下,随剪切乳化速率的增大、乳化时间的加长,油滴粒径越小,油浓度越大,油滴分布越均匀,乳状液越稳定。     

超声波及乳化剂复配对制备微乳柴油的影响

采用超声波处理为分散手段,阳离子表面活性剂十六烷基三甲基溴化铵为主要乳化剂,正丁醇为助剂,制备微乳柴油。优化了超声波作用参数:最佳频率40 kHz,最佳声强0.266 W.cm-2,最佳超声作用时间20 min。研究了复配乳化剂对制备微乳柴油的影响,选择非离子型表面活性剂Span80、Span60,阴离子表面活性剂十二烷基苯磺酸钠与十六烷基三甲基溴化铵复配制备微乳柴油,其中Span80效果最佳,并且处理相同量的微乳柴油,助剂醇的用量降低为原来的1/6。微乳化柴油稳定性良好,至今已放置14个月不分层。     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

Many Drugs of Abuse May Be Acutely Transformed to Dopamine,Norepinephrine and Epinephrine In Vivo

It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

Novel polyurethane coating technology through glycidyl carbamate chemistry

Glycidyl carbamate chemistry combines the excellent properties of polyurethanes with the crosslinking chemistry of epoxy resins. Glycidyl carbamate functional oligomers were synthesized by the reaction of polyfunctional isocyanate oligomers and glycidol. The oligomers were formulated into coatings with several amine functional crosslinkers at varying stoichiometric ratios and cured at different temperatures. Properties such as solvent resistance, hardness, and impact resistance were dependent on the composition and cure conditions. Most coatings had an excellent combination of properties. Studies were carried out to determine the kinetics of the curing reaction of the glycidyl carbamate functional oligomers with multifunctional and model amines. Detailed kinetic analysis of the curing reactions was also undertaken. The results indicated that the glycidyl carbamate functional group is more reactive than a glycidyl ether group. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, on October 27–29, 2004, in Chicago, IL.