Stress, measures

FSW is a new welding technology developed in 1991, but up till now, the study on FSW is mainly focus on the residual stress, micro-structure and thermal effect of specimen etc. However, the stresses of the machine platform have not discussed yet. This research of the stresses of the machine, and the results can be used to design the machine platform of the FSW for micro specimen in the future. The governing equilibrium equation of machine platform under the load was set up in the beginning. Then the equation was solved by using the MATLAB software. The main influence ranges of deflections of the specimen and of the machine platform was obtained and discussed.

Abstract Bridge structures are widely used in the construction for building industrial field in our country. In early time, the materials of the construction and the quality of building cannot match the specification of the governing building due to economic reason. It is caused that both of the ability of vibration resistant and the strength of construction are in dangerous for old building. Therefore, the government established the specifications and standards of the building for the safety and quality. Measuring the bond stress of the armored concrete is included in the standard of the building. The purpose of this research is to study the relationship between natural frequency and bond stress at various ages of armored and the various diameter of reinforcing bar. By comparing the natural frequencies and the bond stress, the results appear that there is no relation between the natural frequency and bond stress in the experiment.

Currently, laser module package is a popular product in optical fiber communication. In the laser module package process smallness is the key point, so dimensions control to influence the oscillation, ageing of material of the laser module operation. This study aim to simulate the laser module weld part's von Mises stress and the laser module weld part's von Mises strain (by using a commercial FEM package, ANSYS) in different temperature cyclic, From the finding of the study, different material property and geometry contour affect the laser module¡¦s ability and cyclic lifespan. For instance Thermal shock will influence the von Mises stress, and thermal cyclic influences viscoplastic strain range and use life. In addation, creep, ageing and stress relaxation happen easily in the high temperature. When the temperature fixes at cyclic period, changing dwell time affects more than changing ramp time. Furthermore, the effects of the study of solder¡¦s geometry contour and the solder¡¦s material property, the behavior of thermal, their advantage and their disadvantageously are also compared in this report. The future, the results obtained by the analytical model will refer to interrelated research.

Feeding the extract of the seaweed Ascophyllum nodosum (ANOD) has been shown to mediate the response of livestock to certain environmental stressors. To determine if feeding ANOD is useful in alleviating handling and transport stress, two trials were conducted. The dose response trial was conducted to determine at which rate ANOD should be fed to obtain beneficial results. Forty-four lambs received ANOD at either 0 (control), 0.5, 1, or 2% of dry matter intake per day (approximately 0, 0.25, 0.5, and 1 g/kg of body wt per day). Sheep were administered ANOD twice daily for 14d. After 14d of supplementation, IgG and IgM antibody response to ovalbumin was reduced by ANOD. The sheep fed at the 2% rate had a narrower range of body temperature during transport than controls. The 2% rate also had lower body temperatures than the controls during times when the thermal heat index was above 80. The sheep fed the 2% rate had lower cortisol and aldosterone concentrations during walking and transport compared to the controls. Post transport, sheep supplemented at the 1 or 2% rates were less dehydrated as indicated by plasma chemistry profiles andelectrolyte concentrations. In a subsequent trial, the major components of the ANOD (fucoidan, salt, and betaine) were fed to determine which, if any, were responsible for the treatment effects in the dose response trial. After 14d supplementation, the salt and ANOD sheep had a depressed IgG and IgM antibody response to ovalbumin and an increase in white blood cell counts and lymphocyte numbers compared to controls. The ANOD sheep were generally lower in body temperature than the other treatments during transport. The ANOD and salt sheep had lower cortisol concentrations compared to controls. At the end of transport, sheep supplemented with ANOD or salt had lower electrolyte concentrations than control sheep. Supplementation with ANOD was associated with lowered body temperature; however, it also suppressed antibody titer which could leave animals susceptible to bacterial infection. The lowered antibody production is of concern and needs further study before ANOD can be recommended as a useful stress management tool.

Half-blood Bonsmara steers were evaluated for temperament during stressful situations to discover the relationships between behavioral stress responses, growth, carcass characteristics and tenderness. Two experiments were conducted to evaluate behavioral stress responses at different stages in the U.S. beef production system with growth, carcass characteristics and tenderness. The first experiment evaluated stress responses at both time of weaning and at the beginning of the feedlot period on half-blood Bonsmara X Beefmaster steers. Steers (n=156) were weaned and paired to destinations of either Uvalde or Overton for winter grazing. At weaning cattle were weighed, and temperament measurements were recorded. After grazing winter pastures, cattle entered the feedlot and were measured for temperament, weight, and condition and frame scores. Cattle were harvested in two groups; each group was selected for harvest when they reached a backfat of approximately 7 mm. Backfat endpoints were determined by visual assessment and ultrasound. Carcass data were recorded approximately 36 hrs post-mortem, and 2.5cm steaks were removed from the 13th rib for Warner-Bratzler shear force determination. The second experiment involved Bonsmara X Angus (n=207) steers grazed on wheat pasture and fed at Cattletown feedlot near Hereford, TX. The steers were evaluated near the beginning and end of the finishing phase for performance and temperament. They were harvested in two groups; each group was selected for harvest when they reached approximately 7 mm of backfat as determined by visual assessment and ultrasound. In experiments 1 and 2, behavioral or temperament measures and hormonal responses were related to each other. It appeared as cattle become acclimated to the production system, temperament measures lose their predictive ability. In Experiment 1, weaning exit velocity appeared to be more related to economically important traits such as ADG (r = -0.26), ribeye area (r = -0.37), and Warner Bratzler shear force (r = 0.27), although beginning feedlot exit velocity was associated with feedlot weights (r = -0.30). In Experiment 2, end feedlot measurements tended to be more associated with feedlot weight (r = -0.20), but there did not seem to be any high relationships with carcass characteristics and tenderness.

Adrenal function, blood metabolites, hematological parameters, growth, and carcass characteristics were compared in tropically-adapted (Brahman,) intermediate (Bonsmara and Bonsmara X Angus crossbred,) and temperate (Angus; n=10 each) beef steers. An adrenal gland challenge was conducted, entailing serial blood collection at 15-min intervals for a 12.5-h period, with administration of exogenous ACTH (0.1 IU/kg BW) 2.5-h into the experiment. Steers were maintained on Coastal bermudagrass pastures overseeded with ryegrass for five month; body weights and blood samples were obtained every 21 days. An anterior pituitary/adrenal gland challenge was conducted, entailing serial blood collection at 120, 90, 60 and 30 min prior to, and 10, 20, 30, 60 and 120 min following administration of exogenous CRH (0.1 ug/kg BW). Physical and physiological signs of heat stress were assessed, and blood samples were obtained for analysis. Exit velocity was measured. Carcass characteristics were determined post-slaughter. Statistical analysis was conducted using ANOVA for repeated measures, using least square means and Pearson’s and Spearman’s correlation analyses. Bonsmara and Bonsmara X Angus had lower basal cortisol (CS) than Angus and Brahman steers. Angus steers had greater adrenal responsiveness to ACTH, and responded faster to CRH than the other breedtypes. Bonsmara steers were slower in responding to CRH, and returning to basal CS following ACTH or CRH administration. Angus and Bonsmara X Angus grew faster during the finishing phase than Brahman or Bonsmara steers. Angus had higher quality grades than other breedtypes; rib-eye area and hot carcass weight were greater in Angus than Brahman steers, but similar among Angus, Bonsmara X Angus and Bonsmara steers. Angus and Brahman were less docile than Bonsmara and Bonsmara X Angus steers. Angus steers had higher respiration rates and serum concentrations of sodium, lower aldosterone during moderate heat exposure, and lesser serum concentrations of glucose, urea and cholesterol than tropically-influenced breedtypes. Angus had rectal and surface temperatures similar to those of Brahman, but greater than those of Bonsmara X Angus or Bonsmara steers. Intermediate breedtypes like the Bonsmara provide a compromise to producers, allowing them to address the demands of consumers while raising cattle better suited to survival in tropical climates.

A finite element is formulated to analyze the deflection and stresses of circular and annular piezoelectric plates underloading of applied electrical potential. The element is based on linear piezoelasticity with displacement field and electrical potential properly assumed. To obtain more accurate nodal stresses , stress recovery is applied which derive nodal stresses from the theoretically accurate stresses at Gaussin points by the least square method. Typical example in the literature are solved by the present method , comparisons are made with those by other methods and experiments to test the validity and accuracy of the present method.

Diss.--Naturwissenschaften--Universität Trier, 2001. / Bibliogr. p. 212-244.

Zugl.: Berlin, Techn. Univ., Diss., 2009