Theoretical and experimental investigations on a new adaptive duo servo drum brake with high and constant brake shoe factor

Khaled R. M. MahmoudPaderborn, Univ., Diss., 200

Towards a learning curve for electric motors production under organizational learning via shop floor data

Due to the fierce market competition, organizations should respond quickly to customers’ needs by reducing lead times, or/and lowering operating costs. These objectives can be reached by effectively assessing the workforce capacities. Manufacturing progress function or organizational learning is considered as one of the most important factors that affect workforce capacity. The current paper introduces an examination research that uses factory data to introduce the most appropriate organizational learning model for the manufacture of electric motors. The data used was collected for a period of 42 months for 110 manufacturing processes and 10 different styles of electric motors. By using regression analysis the significant parameters were obtained for 10 learning models. And in order to select the most reliable one, the analytical hierarchy process (AHP) was used after defining the selection criteria. Among most of monovariable learning models listed in literature the model of Wright (1936) is found to be the best one to fit the data, and then comes the model of Knecht (1974). The failure of the other models in fitting the data was also shown

Relation Between Oxidant/Antioxidant Status and Postpartum Anestrous Conditions

The aim of the present study was to detect the relation between oxidant/antioxidant status and postpartum anestrous (PPA) conditions in dairy cows.The postpartum period is a very critical time that influenced mainly in cattle reproduction. A little information is obtainable in literature concerning antioxidant defense mechanisms during anestrus.The purpose of the following study is detection of the relation between oxidant/antioxidant status and postpartum anestrous (PPA) condition in dairy cows. Seventy five postpartum anestrous (PPA) and twenty five normal cyclic Holstein Friesian pluriparous dairy cows were selected on the basis of their reproductive history gained from farm records. Depend on the rectal findings and ultrasonography in addition to progesterone profile the studied animals were classified into three groups (each 25 animals) as inactive ovaries group, persistent corpus luteum group and silent heat group. Blood samples from anestrous and normal cyclic animals were gathered at day 0, day 10, day 21. These samples were utilized for detection of MDA, Vitamin C, Nitric Oxide and Total antioxidant capacity. Results of the present study revealed that MDA and Nitric Oxide were be significantly (plt0.05) higher in the groups of PPA than the normal cyclic group. Vitamin C (Ascorbic acid)nbsp levels were seen to be significantly (plt0.05) lower in normal cyclic animals in comparison to inactive ovaries group and persistent C.L group ,while there is no significant difference with the silent heat group . No statistically significant difference was detected in the total antioxidant capacity between the group of silent heat and the normal cyclic group, while the groups of persistent C.L and inactive ovaries were found to have statistically significant difference (plt0.05) with the normal cyclic group. It is concluded that supplementing diets with optimal levels of micronutrients with antioxidant capabilities is a good advice to farmers to avoid post-partum anestrum. Moreover, early approaches to conflict the progression of stress and to promote the antioxidant defense mechanisms of dairy cattle during times of increased metabolic demands appears to be Pertinent

Experimental modelling of evaporation and boiling processes in a two-phase thermosyphon

A model of a closed two-phase thermosyphon was developed to study thermo-physical processes in a thermosyphon thermal condition systems of energy-saturated equipment. This model differs from the known by reasoned choice of thermocouples installation providing sealing the device during operation. In addition, the program VI (Virtual Instrument) was created in graphical environment Labview for registration of the temperatures and pressure in the thermosyphon

Clinical utility of calf front hoof circumference and maternal intrapelvic area in predicting dystocia in 103 late gestation Holstein-Friesian heifers and cows

The objective of this study was to determine the clinical utility of measuring calf front hoof circumference, maternal intrapelvic area, and selected morphometric values in predicting dystocia in dairy cattle. An observational study using a convenience sample of 103 late-gestation Holstein-Friesian heifers and cows was performed. Intrapelvic height and width of the dam were measured using a pelvimeter, and the intrapelvic area was calculated. Calf front hoof circumference and birth weight were also measured. Data were analyzed using Spearman's correlation coefficient (rs), Mann–Whitney U test, and binary or ordered logistic regression; P 0.068 cm/cm2). Determining the ratio of calf front hoof circumference to maternal intrapelvic area has clinical utility in predicting the calving difficulty score in Holstein-Friesian cattle