Compression behavior of delaminated composite plates

The response of delaminated composite plates to compressive in-plane loads was investigated. The delaminated region may be either circular or elliptical, and may be located between any two plies of the laminate. For elliptical delaminations, the axes of the ellipse may be arbitrarily oriented with respect to the applied loads. A model was developed that describes the stresses, strains, and deformation of the sublaminate created by the delamination. The mathematical model is based on a two dimensional nonlinear plate theory that includes the effects of transverse shear deformation. The model takes into account thermal and moisture induced strains, transverse pressures acting on the sublaminate, and contact between the sublaminate and plate. The solution technique used is the Ritz method. A computationally efficient computer implementation of the model was developed. The code can be used to predict the nonlinear-load-strain behavior of the sublaminate including the buckling load, postbuckling behavior, and the onset of delamination growth. The accuracy of the code was evaluated by comparing the model results to benchmark analytical solutions. A series of experiments was conducted on Fiberite T300/976 graphite/epoxy laminates bonded to an aluminum honeycomb core forming a sandwich panel. Either circles or ellipses made from Teflon film were embedded in the laminates, simulating the presence of a delamination. Each specimen was loaded in compression and the strain history of the sublaminate was recorded far into the postbuckling regime. The extent of delamination growth was evaluated by C-scan examination of each specimen. The experimental data were compared to code predictions. The code was found to describe the data with reasonable accuracy. A sensitivity study examined the relative importance of various material properties, the delamination dimensions, the contact model, the transverse pressure differential, the critical strain energy release rate, and the relative growth direction on the buckling load, the postbuckling behavior, and the growth load of the sublaminate

Oral History Interview: George Peck Moran

This interview is one of a series conducted concerning West Virginia communities, focusing on Huntington. Mr. Moran discusses the Huntington Police Department, different uniforms, the denomination of the mayor and commissioners, Sam Davis, the first patrol wagon and treatment of prisoners. He also talks about various people he has known throughout the community of Huntington. People mentioned were the Birkes, the Buffingtons, the Ritters and the Rosses\u27. He speaks briefly about the hangings in Ritter Park, the saloons of the red light district, and wrestling matches and circuses that used to come to town. He concludes with the names of buildings that are still standing and their current occupants.https://mds.marshall.edu/oral_history/1557/thumbnail.jp

Immune Blocking of Fluorescent Antibody Staining of Streptococcus Group A Compared with Anti-streptolysin O

The fluorescent antibody blocking antibody (FABA) test has been discribed and compared with the conventional antistreptolysin 0 antibody (ASOA) test in the detection of Streptococcus pyogenes group A antibodies in sera samples. A slide inhibition test was used to detect the presence of FABA in the following manner; (a) fix group A streptococcal cells to a slide, (b) incubate these cells with the patient\u27s serum for thirty minutes, (c) wash off serum with buffered saline and dry, (d) incubate these same cells with group A streptococcal fluorescent tagged antibody for thirty minutes, (e) wash and dry as before, and (f) mount and examine slide with a fluorescent microscope. The presence of streptococcal antibodies in the patients serum will block the staining of the cells with the fluorescent tagged antibody. The FABA titer can be determined by diluting the serum until there is no more blocking effect. Sera from one hundred hospital patients were tested for the presence of FABA and ASOA titers. The probability of a patient having FABA increased in those with elevated ASOA titers, although there was poor correlation of the titers of the two tests. The above experiment was followed by a more controlled experiment using rabbits immunized with different group A streptococcal The antigens were given as follows; (a) two rabbits received Todd-Hewitt broth (THE) as a control, (b) two rabbits received washed antigens. group A streptococcal cells, (c) two rabbits received streptolysin 0 reagent, (d) one rabbit received a THB cell free filtrate of a group A streptococcal culture, (e) two rabbits received live cultures of group A streptococci in THB, and (f) one rabbit received heat killed streptococcal cells in the THB followed by antigen (e). There was no FABA or ASOA response from the rabbit which received antigen (a) and (b). Only the ASOA titer rose with the rabbits receiving antigen (c). Both FABA and ASOA titers rose in rabbits receiving antigen (c). Both FABA and ASOA titers rose in rabbits receiving antigens (d), (e) and (f). The FABA titer rose earlier, went higher and returned to pre-immunizing level before the AOSA titer did. The highest FABA and ASOA titers were reached with using antigen (d). It is evident from the results of this experiment that both the FABA and ASOA are elevated in streptococcal infections but are not the same. The FABA has the characteristics of an antibody. This antibody titer rises earlier and goes higher than the ASOA titer and therefore might be a better diagnostic test for the early detection of streptococcal antibodies in sera of patients. The antigen stimulating the production of FABA has proven to be some portion of the group A streptococcal exudate other than the streptolysins

The development of a proposed series of cartoons aimed at changing the perceptions held toward the Kansas Cooperative Extension Service

Call number: LD2668 .T4 1965 P336Master of Scienc

Rion – Antirion Bridge Foundations: A Blend of Design and Construction Innovation

This case history discusses the design and construction of the appropriate foundation scheme for the largest cable-stayed bridge in the world. This concession project was financed through a combination of public funds, private equity and bank loans. When completed in 2004, the Rion-Antirion Bridge will connect the Peloponnese, Greece’s southernmost peninsula, with the mainland across the Gulf of Corinth. Alternative foundation concepts that were considered included traditional driven piles, deeply embedded caissons, and soil improvement. The process of how the foundation evolved from schematics to final design, what were the driving forces, how ideas were disseminated among the Design Team, the Design Checker and the Technical Advisors, and the performance of the foundations to date are summarized

Causal Relationship of Susceptibility Genes to Ischemic Stroke: Comparison to Ischemic Heart Disease and Biochemical Determinants

Interrelationships between genetic and biochemical factors underlying ischemic stroke and ischemic heart disease are poorly understood. We: 1) undertook the most comprehensive meta-analysis of genetic polymorphisms in ischemic stroke to date; 2) compared genetic determinants of ischemic stroke with those of ischemic heart disease, and 3) compared effect sizes of gene-stroke associations with those predicted from independent biochemical data using a mendelian randomization strategy. Electronic databases were searched up to January 2009. We identified: 1) 187 ischemic stroke studies (37,481 cases; 95,322 controls) interrogating 43 polymorphisms in 29 genes; 2) 13 meta-analyses testing equivalent polymorphisms in ischemic heart disease; and 3) for the top five gene-stroke associations, 146 studies (65,703 subjects) describing equivalent gene-biochemical relationships, and 28 studies (46,928 subjects) describing biochemical-stroke relationships. Meta-analyses demonstrated positive associations with ischemic stroke for factor V Leiden Gln506, ACE I/D, MTHFR C677T, prothrombin G20210A, PAI-1 5G allele and glycoprotein IIIa Leu33Pro polymorphisms (ORs: 1.11 – 1.60). Most genetic associations show congruent levels of risk comparing ischemic stroke with ischemic heart disease, but three genes—glycoprotein IIIa, PAI-1 and angiotensinogen—show significant dissociations. The magnitudes of stroke risk observed for factor V Leiden, ACE, MTHFR and prothrombin, but not PAI-1, polymorphisms, are consistent with risks associated with equivalent changes in activated protein C resistance, ACE activity, homocysteine, prothrombin, and PAI-1 levels, respectively. Our results demonstrate causal relationships for four of the most robust genes associated with stroke while also showing that PAI-1 4G/5G polymorphism influences cardiovascular risk via a mechanism not simply related to plasma levels of PAI-1 (or tPA) alone

Dysglycemia associations with adipose tissue among HIV-infected patients after 2 years of antiretroviral therapy in Mwanza: a follow-up cross-sectional study.

BACKGROUND: Data on the burden of dysglycemia among HIV-infected patients on antiretroviral therapy (ART) in Africa are limited. We determined the prevalence of pre-diabetes and diabetes among HIV-infected patients who started ART when malnourished 2 to 3 years previously and investigated the association of dysglycemia with body composition. METHODS: Malnourished (body mass index (BMI) < 18.5 kg/m2) HIV-infected patients who were enrolled in the Nutritional Support for Africans Starting Antiretroviral Therapy (NUSTART) trial from 2011 to 2013 were followed-up from March to August 2015. Anthropometric, fat mass and fat-free mass by bioelectrical impedance, and C-reactive protein (CRP) data were collected at baseline and follow-up. At follow-up, we defined fasting glucose of 6.1-6.9 mmol/L as impaired fasting glucose (IFG) and 2-h oral glucose tolerance test (OGTT) glucose of ≥7.8 to <11.1 mmol/L as impaired glucose tolerance (IGT). Both of these were considered pre-diabetes. Fasting glucose of ≥7.0 mmol/L or impaired glucose tolerance of ≥11.1 mmol/L was defined as diabetes mellitus. The relation of pre-diabetes and diabetes with body composition was assessed using logistic regression. RESULTS: Two hundred seventy-three (57%) of 478 patients who were alive at trial conclusion were followed-up. The mean age was 41.5 (SD 9.8) years and 65.2% (178) were females. The mean follow-up BMI was 19.9 (SD 2.8) kg/m2, 12 (4.4%) were either overweight or obese, and 61 (22.3%) patients had pre-diabetes or diabetes. In multiple regression, upper tertiles of baseline hip circumference (OR: 0.41, 95% CI: 0.2, 0.8) and fat mass index (OR: 0.20 (0.1, 0.5), and upper tertiles of follow-up waist circumference (OR: 0.22 (0.1, 0.5), BMI (OR: 0.32 (0.1, 0.7), fat mass index (OR: 0.19 (0.1, 0.5) and the middle tertile of follow-up fat-free mass (OR: 0.36, 95% CI: 0.1, 0.8) were associated with lower risk of pre-diabetes and diabetes (P < 0.05 for all). Baseline and follow-up CRP were not predictors. CONCLUSIONS: Low rather than high measures of adipose tissue were associated with increased risk of pre-diabetes and diabetes. Additional studies are needed to further investigate the role of body composition and control of glucose metabolism in the pathogenesis of diabetes among persons living with HIV in Africa

Adrenal Function in Women with Idiopathic Acne

The adrenal secretion of androgens was examined in 9 women (ages 19–39 yr) with postadolescent idiopathic acne and compared to age and sex-matched normal controls. Plasma dehydroepiandrosterone (DHA), dehydroepiandrosterone sulfate (DHAS), androstenedione (Δ4-A), cortisol, 17-hydroxyprogesterone, 11-deoxycortisol, and testosterone were measured by radioimmunoassay in the basal state and during a 48hr ACTH infusion. The mean plasma and time-integrated plasma levels of the 3 adrenal androgens in patients with acne were 15–25% higher than normal controls, but the groups were not significantly different (p > .05). The plasma testosterone values, on the other hand, were similar in both groups. In addition, cortisol, 11-deoxycortisol and 17-hydroxyprogesterone basal plasma values and responses to ACTH in patients with acne were similar to the normal control values. These findings suggest that adrenal androgen secretion is at most mildly elevated in patients with idiopathic acne and is unlikely to be the sole cause of acne since many patients without acne have similar hormone levels. Increased sensitivity of the sebaceous gland to androgens or increased local metabolism of androgen hormones in the skin to potent androgen metabolites may offer alternative mechanisms for the pathogenesis of this disorder