Optimization‐driven design of dies for profile extrusion: Parameterization,strategy, and performance

A computational design optimization environment is developed, handling, for the first time, streamline dies used for profiles in unplasticized polyvinyl chloride (uPVC) having multiple complex features, as well as simpler designs. Die cavity cross sections are described by planar contours, such as the cutting paths for wire electrical discharge machining of the plates from which streamline profile dies are constructed. Contours are parameterized using key points, and by joining the contours with ruled surfaces, the three‐dimensional geometry can be reconstructed. For the optimization a developed flow analysis on each die cross section is used with the avoid‐cross‐flow strategy. Cross sections are partitioned and the die is balanced to obtain the required flow rate through each. A robust and efficient parallel decoupled optimization strategy is developed. In application to a uPVC window profile, five cross sections were optimized. The number of design variables on each ranged from 2 to 46, and the cross section optimizations converged within one to seven cycles. Compared with the work of an experienced designer making manual changes to the computer‐aided design model, guided by computational fluid dynamics analyses, the design quality was comparable or better and computational demands similar; however, the time required from the designer was reduced seven times. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers     

Oil quenched malleable iron,the strength of an old material in a “green cast” development and a new future

Malleable iron lost the interest and the development stopped in the turbulent seventies of tremendous developments of new technologies.The personal computer,emission spectrometer,thermal analysis,cold-box core system and automatic vertical moulding were introduced into the foundry industry.Experience shows that these new technologies do not always match up with malleable iron.Solidification and mould filling simulation programs are not always capable to handle a low carbon equivalent iron like malleable iron.Recent developments show however by using these new technologies and combined with practical experience,it is possible to increase the casting yield of malleable iron to the same level as ductile iron.The mechanical properties,especially the yield strength of malleable iron according to the standard are equivalent to those of ductile iron,however the yield strength of oil quenched malleable iron is significantly higher than that of ductile iron.An extensive investigation is made between ductile iron,air quenched and oil quenched malleable irons based on the properties of more than 350 test bars produced under the same conditions.The results are compared with the existing international standards and discussed.Other properties like fatigue strength and response to surface treatments as induction hardening are also discussed.The costs of malleable iron are reviewed and compared with other ferro alloys.These recent developments in increasing the casting yield,the understanding of the strength,makes malleable iron competitive with ductile iron and cheaper than the first grade of ausferritic ductile iron,or steel qualities.It is possible to design lighter and save weight which is essential in the automotive industry.An example of"green cast"development for typical applications,used in automotive transmissions and engines are shown.     

油淬可锻铸铁的强度和新的应用

最近的研究表明,通过采用新技术并与实践经验相结合,有可能使可锻铸铁的铸件年产量达到与球墨铸铁相同的水平.根据标准,可锻铸铁的力学性能和比屈服强度与球墨铸铁的相当,但是油淬可锻铸铁的屈服强度明显高于球墨铸铁的屈服强度.根据在相同条件下生产的超过350根试棒的性能,对球墨铸铁、空淬可锻铸铁和油淬可锻铸铁开展了范围广泛的调查和研究.对研究结果与现有的国际标准进行了比较和讨论.还讨论了其他性能.例如疲劳强度和对感应硬化那样的表面处理的响应特性.回顾和评价了可锻铸铁的成本并与其他铁基合金进行了比较.在提高铸件收得率和对强度认识方面的这些最新研究,使可锻铸铁能够与球墨铸铁相竞争,其价格比最高级别的奥铁铸铁便宜,其质量或可与钢媲美.有可能使设计轻量化而减轻零件的质量,这在汽车工业中是极其重要的.展示了"绿色铸造"研发的用于汽车传动装置和发动机的典型应用实例.     

Sensory properties of thickened and protein-enriched plant-based frozen desserts

The number of consumers following plant-based diets has increased and in turn, the variety of plant-based foods available on the market has also increased. Many plant-based foods aim to mimic the functionality and sensory properties of conventional dairy products; however, they may not be suitable for specific populations. Dysphagia, for example, is a swallowing condition requiring texture-modified foods that meet specific criteria. While many conventional thickened products exist that are safe for individuals with dysphagia, the growing interest in plant-based eating alongside the increasing prevalence of dysphagia prompts a need for research on the use and safety of thickened plant-based alternatives. This study investigated the sensory properties of a thickened protein-enhanced ice cream (dairy and whey) compared to thickened protein-enhanced plant-based frozen desserts (cashew and pea, and coconut and pea). The formulations were evaluated using the International Dysphagia Diet Standardization (IDDSI) Spoon Tilt Test and a sensory trial (n = 104 participants, 47 flexitarians and 57 typical consumers) using static (hedonic scales and check-all-that-apply [CATA]), and dynamic (temporal check-all-that-apply (TCATA)) methods. The dairy and whey sample consistently passed the IDDSI test, while the plant-based samples did not. TCATA identified that the plant-based samples had an increased cohesiveness and adhesiveness, and decreased slipperiness when compared to the dairy and whey sample. The differences in textural properties may explain why the plant-based samples did not pass the IDDSI test. The study identified that although plant-based foods strive to mimic conventional dairy products, they have different textural and flavor properties.     

Activity Counseling Trial (ACT): rationale, design, and methods. Activity Counseling Trial Research Group

The Activity Counseling Trial (ACT) is a multicenter, randomized controlled trial to evaluate the effectiveness of interventions to promote physical activity in the primary health care setting. ACT has recruited, evaluated, and randomized 874 men and women 35-75 yr of age who are patients of primary care physicians. Participants were assigned to one of three educational interventions that differ in amount of interpersonal contact and resources required: standard care control, staff-assisted intervention, or staff-counseling intervention. The study is designed to provide 90% power in both men and women to detect a 1.1 kcal.kg-1.day-1 difference in total daily energy expenditure between any two treatment groups, and over 90% power to detect a 7% increase in maximal oxygen uptake, the two primary outcomes. Primary analyses will compare study groups on mean outcome measures at 24 months post-randomization, be adjusted for the baseline value of the outcome measure and for multiple comparisons, and be conducted separately for men and women. Secondary outcomes include comparisons between interventions at 24 months of factors related to cardiovascular disease (blood lipids/lipoproteins, blood pressure, body composition, plasma insulin, fibrinogen, dietary intake, smoking, heart rate variability), psychosocial effect, and cost-effectiveness, and at 6 months for primary outcome measures. ACT is the first large-scale behavioral intervention study of physical activity counseling in a clinical setting, includes a generalizable sample of adult men and women and of clinical setting, and examines long-term (24 months) effects. ACT has the potential to make substantial contributions to the understanding of how to promote physical activity in the primary health care setting.     

Postoperative electromyographic monitoring of small intestine function in patients with peritonitis and acute intestinal obstruction

In 49 patients with general peritonitis and acute ileus, the authors used the method of direct electromyography. On the basis of analysis of the results, the functional state of the intestine, dynamics of its motor activity, effectiveness of the treatment performed were assessed and outcome of the disease was predicted.     

Oral health of persons with and without dementia attending a geriatric clinic

Results of a 20 month split-udder trial on the effect of discontinuation of postmilking teat disinfection on intramammary infections (IMI) with major and minor pathogens in seven dairy herds with a low somatic cell count are described. The incidence of Escherichia coli IMI was found to be significantly lower, whereas the incidence of IMI with Staphylococcus aureus and minor pathogens was significantly higher in quarters for which postmilking teat disinfection was discontinued than in disinfected quarters. It was concluded that discontinuation of postmilking teat disinfection decreased the incidence of E. coli IMI, accompanied by a, from a practical point of view, acceptable rise in somatic cell count. However, the possible increase in the incidence of S. aureus IMI calls for careful monitoring of the dynamics of IMI with contagious pathogens, when postmilking teat disinfection is discontinued in an attempt to reduce E. coli mastitis.     

Neuropsychiatric function and dehydroepiandrosterone sulfate in elderly women: a prospective study

BACKGROUND: Though among the most abundant human steroid hormones, the physiologic role of dehydroepiandrosterone and its sulfate (DHEAS) is not known. Our goal was to determine if DHEAS is associated with cognition and mood in older women, and if baseline DHEAS levels are predictive of cognitive decline. METHODS: In a prospective cohort, we studied 394 randomly selected community-dwelling women, aged 65 years or older, currently enrolled in the Study of Osteoporotic Fractures. Subjects were administered a modified Mini-Mental State Exam, Trials B, Digit Symbol, and the Geriatric Depression Scale-Shortened (GDSS), at study onset and 4-6 years later. Serum was obtained at study initiation for DHEAS analysis. RESULTS: DHEAS levels declined with age, as expected. There was no consistent association of DHEAS quartile or log DHEAS with any of the four outcomes, even after multivariate adjustment. Change in cognitive performance overtime was not associated with DHEAS levels. Analysis of the 32 women without any detectable DHEAS compared to those with detectable levels revealed higher measures on the GDSS (mean score 3.4 +/- 3.6 compared with 1.6 +/- 2.3, p = .028) and a higher percentage with depression (21.7% compared with 4.6%, p = .001). CONCLUSIONS: Serum DHEAS is not a sensitive predictor of cognitive performance or decline on a selected neuropsychological battery in elderly community women; however, nondetectable levels may be associated with depression.