Total fatty acid analysis of vegetable oil soapstocks by supercritical fluid extraction/reaction

Soapstock from vegetable oil refining operations is a value-added by-product that finds further industrial use based on its fatty acid content. Since the fatty acid content of soapstock can vary according to its vegetable oil source or method of refining, determination of its total fatty acid (TFA) by an accurate analytical method is of key importance to purchasers of this refinery by-product. Traditionally, the TFA content of soapstock has been determined by the AOCS Official Method G3-53 based on a gravimetric assay. Unfortunately, this gravimetric-based assay requires considerable time and incorporates a considerable quantity of organic solvent per assay. In this study, the authors have applied supercritical fluid extraction (SFE) with an enzymatic-based reaction (SFR), in the presence of supercritical carbon dioxide (SC-CO₂), to determine the TFA content of soapstocks. The SFE/SFR sequence was conducted using two commercially available extractors using an in situ supported lipase in the extraction cell to form fatty acid methyl esters (FAME). Gas chromatographic (GC) determination of the individual FAME, followed by quantitation based on the calculated sum of all the fatty acids from the GC analysis, allowed a precise determination to be made of the soapstock’s TFA content. The TFA contents of three different soapstocks determined by this method were slightly higher than the values derived from Official Method G3-53. The reported method takes less than one-half of the time of Official Method G3-53 and reduces organic solvent use from 575 mL to under 2 mL of solvent by using SC-CO₂.     

Hydrogenation of vegetable oils using mixtures of supercritical carbon dioxide and hydrogen

Hydrogenation of vegetable oils under supercritical conditions can involve a homogeneous one-phase system, or alternatively two supercritical components in the presence of a condensed phase consisting of oil and a solid catalyst. The former operation is usually conducted in flow reactors while the latter mode is more amenable to stirred, batch-reactor technology. Although many advantages have been cited for the one-phase hydrogenation of oils or oleochemicals using supercritical carbon dioxide or propane, its ultimate productivity is limited by the oil solubility in the supercritical fluid phase as well as unconventional conditions that affect the hydrogenation. In this study, a dead-end reactor has been utilized in conjunction with a head-space consisting of either a binary fluid phase consisting of varying amounts of carbon dioxide mixed with hydrogen or neat hydrogen for comparison purposes. Reaction pressures up to 2000 psi and temperatures in the range of 120–140°C have been utilized with a conventional nickel catalyst to hydrogenate soybean oil. Depending on the chosen reaction conditions, a wide variety of end products can be produced having different iodine values, percentage trans fatty acid content, and dropping points or solid fat indices. Although addition of carbon dioxide to the fluid phase containing hydrogen retards the overall reaction rate in most of the studied cases, the majority of products have low trans fatty acid content, consistent with a nonselective mode of hydrogenation.     

Resolution of a controversy surrounding the Kirchhoff approach and the small perturbation method in rough surface scattering theory

It is shown that the small amplitude limit of the mean backscatter cross section for a perfectly conducting random rough surface calculated from the first two terms in the iterative series solution of the surface current integral equation gives the same results as the small perturbation method. This demonstration resolves a long-standing controversy in rough surface scattering theory.     

Multivariate analyses of the hominid ulna from Klasies River mouth

BACKGROUND: The combination of 5-fluorouracil (5-FU) and cisplatin has shown great activity in many different types of tumour with an in vitro synergistic effect between 5-FU and cisplatin. A phase II study of 5-FU plus cisplatin was performed in 25 previously untreated patients with inoperable locally advanced or metastatic biliary tract carcinoma. PATIENTS AND METHODS: Twenty-five patients, 10 of them men and 15 women with a median age of 58, were entered into the study. The chemotherapy regimen consisted of 5-FU: 1 g/m2/day in continuous intravenous (i.v.) infusion for five consecutive days, and cisplatin: 100 mg/m2/day on day 2 in a one-hour infusion with standard hyperhydration. Twenty-two patients had metastatic tumours and three had locally advanced disease. RESULTS: Of the 25 patients entered into the study, 24 were evaluable for response and 25 for toxicity. Nausea and vomiting was the main toxic side effect in 19 patients. Severe, WHO grade 3-4 thrombocytopenia or neutropenia were observed in three and seven patients, respectively. There were no toxic deaths. Of 25 patients, six had partial remissions (overall response 24%, 95% confidence interval 7%-41%). For three patients, tumour reduction permitted local radiotherapy and one of these patients with initially advanced disease is still alive six years after the beginning of treatment. CONCLUSIONS: This study, one of the largest phase II trials performed in this disease, shows interesting activity of the combination of 5-FU and cisplatin in advanced biliary tract carcinoma.     

The Children of Divorce Intervention Program: Development, implementation, and evaluation of a program for young urban children.

This study evaluated the effectiveness of a 16-week preventive intervention for 52 second- and third-grade urban children of divorce. The program extended the Children of Divorce Intervention Program (CODIP), a school-based program originally developed for fourth–sixth-grade suburban children. CODIP's main goal is to mitigate the behavioral and emotional problems that occur in the wake of divorce. The program promotes support, helps children identify and express divorce-related feelings, clarifies divorce-related concepts and misconceptions, and develops relevant coping skills as well as positive self- and family-perceptions. Participants were compared with 52 divorce controls and 81 demographically matched children from intact families on child, parent, and teacher measures of adjustment. The experimental group improved significantly more than nonprogram groups from multiple perspectives, suggesting that the intervention enhanced children's ability to cope with the stressful experiences often associated with parental divorce. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Beginnings and Endings: Phoebe Stanton on Pugin's Contrasts

STATEMENT OF RETRACTION. This article previously published in Journal of Architectural Education, vol 65, issue 2, 2012, pages 106–116, doi: 10.1111/j.1531-314X.2011.01188.x. Due to numerous errors in logic and layout based on problems during the production process that version has been retracted and should not be cited. The article is being reprinted here in corrected form and is the final version of record for citation.     

Progress towards the commercial application of gold catalysts

Now that gold catalysis is a valuable and exciting new field of catalysis as a whole, the exploitation of gold catalysts for commercial applications is being pursued. This is being assisted by new work on preparation and utilization methods to increase their durability during use. Other factors, including a substantial increase in investment in gold catalysis R&D, need to be considered before widespread application will occur. We show that new opportunities for commercial exploitation can be monitored via patent mapping, followed by careful examination of key patents.     

基于三电平子模块的倍电平复合式MMC变换器

为了降低模块化多电平变换器MMC(modular multilevel converter)的接线复杂度和通信失效故障概率,ABB提出了采用压接式IGBT串联的级联两电平CTL(cascaded two-level)变换器。由于桥臂子模块数由数百降为几十,CTL变换器输出电压电平数较少,需要在交流侧安装滤波器。为此,提出了基于三电平TL(three-level)子模块的倍电平复合式MMC变换器VLD-HMMC(voltage-level-doubler hybrid MMC)。每个桥臂有TL、半桥HB(halfbridge)子模块混合组成,且交流侧串联有一个全桥FB(full-bridge)子模块,输出电压电平数提高了1倍,从而省去了交流滤波器。各子模块具有脉冲自主触发功能且其功率开关由压接式器件串联组成,降低了桥臂子模块数,简化了控制器与主电路之间的接线复杂度,降低了通信故障的概率。单个功率开关短路故障不会影响系统正常运行,并且可避免了子模块电容的过度放电,保护电容器和功率开关,提高变换器的可靠性及故障穿越能力。所提拓扑结构实现了直流故障穿越运行,为HVDC换流站的设计提供了技术参考。