气井涡流排水采气新技术及其应用

涡流排水采气技术是一项由中国石油天然气集团公司于2011年率先引进的排水采气新技术，既可应用于气井井下，也可应用于地面集输系统。为此，在论述了气井井下涡流排水采气的工艺原理、技术优点，工具组成、下入操作程序的基础上，总结了该技术在松辽盆地、鄂尔多斯盆地所取得的主要成果、经验与认识，并进一步提出了深入进行科研、试验与攻关的可行性建议。结论认为：应在总结升1-1、苏36-4-3等井试验经验的基础上，针对我国有水气田开发的实际情况，加强涡流排水采气工艺的适应性、影响因素及关键技术的研究，並从选井原则的合理确定、优化设计与座封方式、优化组合等方面入手，学习国外成功经验，进一步加快该项工艺技术在我国的推广应用步伐。     

山溪坝后式取水及明渠弯道除沙方式研究

随着我国水利水电工程建设的发展,水电站分布越来越集中于偏远山区,供水系统往往需自行建设。为了解决工程建设施工及生活用水问题,通常是将工程附近水源水质较好的山溪作为取水点,并经简单沉沙处理后投入使用。传统的坝前式山溪取水及大型沉沙池除沙普遍面临着汛期取水头部易被泥石流淤积、山溪内施工部位狭窄等问题,根据弯道环流原理,结合杨房沟水电站供水系统取水头部设计及运行使用经验,研究验证了坝后式取水代替传统的坝前式取水,以及明渠除沙代替大型沉沙池除沙方式的实际效果。实践表明,新的取水方式可以满足抗淤能力强、施工占地少,同时除沙能力理想的要求,可为今后类似情况下山溪取水及除沙方式的选择提供参考。     

某钢厂自备工业水厂设计

自备工业水厂总设计规模3.8×104m3/d,分两期建设,一期规模1.9×104m3/d。净水工艺流程采用折板絮凝池—斜管沉淀池—V型滤池的常规处理工艺。简要介绍了工程主要建、构筑物工艺设计参数、设备配置情况等,并对工艺设计特点及水厂的运行情况进行总结。     

A robust weakly compressible SPH method and its comparison with an incompressible SPH

This paper presents a comparative study for the weakly compressible (WCSPH) and incompressible (ISPH) smoothed particle hydrodynamics methods by providing numerical solutions for fluid flows over an airfoil and a square obstacle. Improved WCSPH and ISPH techniques are used to solve these two bluff body flow problems. It is shown that both approaches can handle complex geometries using the multiple boundary tangents (MBT) method, and eliminate particle clustering‐induced instabilities with the implementation of a particle fracture repair procedure as well as the corrected SPH discretization scheme. WCSPH and ISPH simulation results are compared and validated with those of a finite element method (FEM). The quantitative comparisons of WCSPH, ISPH and FEM results in terms of Strouhal number for the square obstacle test case, and the pressure envelope, surface traction forces, and velocity gradients on the airfoil boundaries as well as the lift and drag values for the airfoil geometry indicate that the WCSPH method with the suggested implementation produces numerical results as accurate and reliable as those of the ISPH and FEM methods. Copyright © 2011 John Wiley & Sons, Ltd.     

Both a higher number of sips and a longer oral transit time reduce ad libitum intake

BackgroundA higher eating rate leads to a higher food intake, possibly through shorter orosensory exposure to food. The transit time in the oral cavity and the number of bites or sips per gram (inversely related to bite or sip size) are main contributors that affect eating rate. The separate role of these two aspects on satiation and on orosensory exposure needs further clarification.ObjectiveThe objective of the first study was to investigate contributions of the number of sips per gram (sips/g) and oral transit time per gram (s/g) on ad libitum intake. The objective of the second study was to investigate both aspects on the total magnitude of orosensory exposure per gram food.MethodsIn study 1, 56 healthy male subjects consumed soup where the number of sips and oral transit time differed by a factor three respectively: 6.7 vs. 20 sips/100 g, and 20 vs. 60 s/100 g (2 × 2 cross-over design). Eating rate of 60 g/min was kept constant. In study 2, the effects of number of sips and oral transit time (equal as in study 1) on the total magnitude of orosensory exposure per gram soup were measured by time intensity functions by 22 different healthy subjects.ResultsHigher number of sips and longer oral transit time reduced ad libitum intake by respectively ∼22% (F(1, 157) = 55.9, P < 0.001) and ∼8% (F(1, 157) = 7.4, P = 0.007). Higher number of sips led to faster increase in fullness per gram food (F(1, 157) = 24.1, P < 0.001) (study 1). Higher number of sips and longer oral transit time both increased the orosensory exposure per gram food (F(1, 63) = 23.8, P < 0.001) and (F(1, 63) = 19.0, P < 0.001), respectively (study 2).ConclusionHigher number of sips and longer oral transit time reduced food intake, possibly through the increased the orosensory exposure per gram food. Designing foods that will be consumed with small sips or bites and long oral transit time may be effective in reducing energy intake.     

Modification of appetite by bread consumption: A systematic review of randomized controlled trials

The inclusion of different ingredients or the use of different baking technologies may modify the satiety response to bread, and aid in the control of food intake. The aim of this study was to perform a systematic search of randomized clinical trials on the effect of bread consumption on appetite ratings in humans. The search equation was (“Bread”[MeSH]) AND (“Satiation”[MeSH] OR “Satiety response”[MeSH]), and the filter “clinical trials.” As a result of this procedure, 37 publications were selected. The satiety response was considered as the primary outcome. The studies were classified as follows: breads differing in their flour composition, breads differing in ingredients other than flours, breads with added organic acids, or breads made using different baking technologies. In addition, we have revised the data related to the influence of bread on glycemic index, insulinemic index and postprandial gastrointestinal hormones responses. The inclusion of appropriate ingredients such as fiber, proteins, legumes, seaweeds and acids into breads and the use of specific technologies may result in the development of healthier breads that increase satiety and satiation, which may aid in the control of weight gain and benefit postprandial glycemia. However, more well-designed randomized control trials are required to reach final conclusions.     

Steady and transient inflow dynamics with actuator disk vortex theory

The actuator disk is a well‐known and widely used theoretical tool in wind engineering. This work proposes a new theory based on an actuator surface, capable of treating time‐varying vectorial load distributions and yaw/pitch misalignment. A simplified representation of vortex motion is used to arrive at a tractable problem. The theory is not restricted to disks; arbitrary coplanar (optionally disjoint) actuator surfaces may be modeled. Some of the theoretical novelties used in the modeling includes use of the fractional Laplacian and extensive use of the Fourier transform on . Promising experimental validation based on pitch‐step experiments at the Tjæreborg turbine is furnished. Comparisons are also made to existing methodologies. Analysis and numerical work shows that the model encapsulates Coleman's vortex theory.     

Numerical study on erosion of a pipe bend with a vortex chamber

Abrasive erosion at bend is a common issue in gas–solid pneumatic system. Vortex chamber design is one of the specialized designs that offers promising prospect at reducing erosion. The performance of design is still relatively unknown in the literature. The aim of this work is to study the effect of basic erosion variables such as the flow Reynolds number, the particle Stokes number, and the vortex chamber size. The results show that the vortex chamber always reduces the erosion in comparison to the common radius bend, and it is more effective at higher Reynolds number. Increasing the chamber size reduces the erosion but the most significant reduction happens when the chamber size to the pipe diameter ratio is increased from 1 to 1.25. The chamber size influences the erosion differently at different Reynolds number. Trends describing these effects were obtained through trial-and-error approach. The particle Stokes number has nonunique effect on erosion. Increasing Stokes number through increasing Re increases the erosion while increasing Stokes number through decreasing Re_p decreases the erosion.     

Prepartum dietary energy intake alters hepatic expression of genes related to peroxisome proliferator-activated receptor and inflammation in peripartal dairy cows

We determined the effect of prepartum plane of energy intake on liver function and metabolism pre- and postpartum by combining in vivo and in vitro data with mRNA expression data. A subset of multiparous prepartal Holsteins (n = 18) from a previously conducted experiment consumed 1 of 3 amounts of dietary energy intake, relative to their requirements. A diet formulated to allow consumption of ≥150% of net energy requirements during the far-off dry period and the close-up dry period was fed for ad libitum intake (150E) or in restricted amounts so that cows consumed 80% of requirements for energy (80E). A second diet was formulated to include wheat straw (26.1% of dry matter) to limit energy intake to 100% of NRC (2001) requirements for energy when fed ad libitum during the far-off period (100E). In the close-up period, 100E was fed the 150E diet for ad libitum intake. Expression of mRNA for genes related to fatty acid oxidation (PPARA, CPT1A, ACOX1) was greater for 100E cows than 150E cows on d 14 postpartum. These expression patterns were related to in vitro data for conversion of palmitate to CO₂, acid-soluble products, and esterified products by liver slices. Abundance of mRNA for PC displayed a sharp peak for all groups on d 1 postpartum, but serum glucose did not reflect this peak. The mRNA expression of SREBF1 was greater for 150E and 100E cows prepartum compared with 80E, and was positively related to rate of palmitate esterification postpartum. Expression of NR1H3 (LXRA) mRNA was greater for 100E cows on d 14 postpartum compared with 150E cows, which corresponded to expression of PPARA. An inflammatory response occurred in the liver around the time of parturition for 150E cows, as expression of IL1B was elevated both pre- and postpartum compared with 100E cows. The spike in IL1B expression for 150E cows on d 14 postpartum corresponded to the peak concentration of total lipids in liver tissue for all groups in this experiment. Overconsumption of energy prepartum was detrimental to the expression of important genes related to PPAR and liver function, especially postpartum. Furthermore, results provide evidence for inflammation related to accumulation of lipids in liver and overnutrition prepartum.     

Food satisfaction: Integrating feelings before,during and after food intake

Consumers’ satisfaction is important for the food industry to ensure product success. Determinants to food satisfaction are multifactorial and a method approaching the multiple determinants would provide a detailed picture of determinant behind consumers’ hedonic food appreciation.The aims of this study were (1) to develop a method that could give detailed information about sensory- and food satisfaction (2) to study differences in sensory satisfaction in a case study, and (3) to study the factors related to food satisfaction. Focus group interviews and a literature study provided an overview of factors with potential to affect food satisfaction. A total of four questionnaires, covering factors before-, during- and after intake as well as demographics, were developed to measure factors related to satisfaction. The questionnaires were utilised in a cross-over consumer study with 79 subjects consuming two sensory different variants of chicken soup. Soups were sensory evaluated utilising expert statements. The consumer study showed that sensory satisfaction was highly influenced by liking of taste and appearance, whereas liking of odour and texture influenced sensory satisfaction moderately. Food satisfaction was influenced by factors measured during- and post intake; sensory satisfaction, fulfilment of expectations, reason for ending intake, product performance relative to expectations, hunger and fullness after intake were found highly influential in food satisfaction. Pre-intake factors did not substantially influence food satisfaction. Though the use of multiple variables gave a detailed picture of factors involved in food satisfaction, there was still variation in food satisfaction that remained unaccounted.