Strength and Serviceability of FRP Grid Reinforced Bridge Decks

The research presented in this paper evaluates the flexural performance of bridge deck panels reinforced with 2D fiber-reinforced polymer (FRP) grids. Two different FRP grids were investigated, one reinforced with a hybrid of glass and carbon fibers and a second grid reinforced with carbon fibers only. Laboratory measured load-deflection, load-strain (reinforcement and concrete), cracking, and failure behavior are presented in detail. Conclusions regarding failure mode, limit-state strength, serviceability, and deflection compatibility relative to AASHTO mandated criteria are reported. Test results indicate that bridge decks reinforced with FRP grids will be controlled by serviceability limit state and not limit-state ultimate strength. The low axial stiffness of FRP results in large service load flexural deflections and reduced shear strength. In as much as serviceability limits design, overreinforcement is recommended to control deflection violation. Consequently, limit-state flexural strength will be compression controlled for which reduced service stresses or ACI unified compression failure strength reduction factors are recommended.     

Combination "sandwich" therapy for extensive renal calculi in 100 consecutive patients: immediate, long-term and stratified results from a 10-year experience

A relationship between the presence of platelet autoantibodies and major histocompatibilty complex class II alleles was determined in 27 patients with lupus anticoagulants. Twenty-two patients had a primary antiphospholipid syndrome' and five patients had lupus erythematosus (SLE). Platelet antibodies against the platelet glycoproteins (GP) IIb/IIIa were detectable in 20 patients. Anti-GPIb/IX or -GPIV antibodies were detectable only in patients with anti-GPIIb/IIIa antibodies. An increased frequency of HLA-DQB1*06 was demonstrable in the total patient population. The association between the lupus anticoagulants and HLA-DQB1*06 was even stronger if patients also had detectable platelet antibodies. This association was also seen if patients with a history of thromboembolic disease were considered separately. However, within the patient population there was no difference between frequencies of HLA alleles detectable platelet antibodies.     

Oleamide potentiates benzodiazepine-sensitive gamma-aminobutyric acid receptor activity but does not alter minimum alveolar anesthetic concentration

Short-term exposure to ozone at peak ambient levels induces neutrophil influx and impairs lung function in healthy humans. In order to investigate the mechanisms contributing to neutrophil recruitment and to examine the role of T-cells in the acute inflammatory response, we exposed 12 healthy humans to 0.2 parts per million (ppm) of ozone and filtered air on two separate occasions for 2 h with intermittent periods of rest and exercise (minute ventilation = 30 L x min(-1)). Fibreoptic bronchoscopy was performed 6 h after the end of exposures. Total protein, tryptase, histamine, myeloperoxidase, interleukin (IL)-8 and growth-related oncogene-alpha (Gro-alpha) were measured and total and differential cell counts were performed in bronchoalveolar lavage (BAL) fluid. Flow cytometry was performed on BAL cells to study total T-cells, T-cell receptors (alphabeta and gammadelta), T-cell subsets (CD4+ and CD8+ cells) and activated T-cell subsets (CD25+). Using immunohistochemistry, neutrophils, mast cells, total T-cell numbers, T-cell subsets, CD25+ T-cells and leukocyte endothelial adhesion molecules including P-selectin, E-selectin, intercellular adhesion molecule (ICAM)-1 and vascular adhesion molecule (VCAM)-1 were quantified in the bronchial biopsies. Paired samples were available from nine subjects. Following ozone exposure there was a threefold increase in the proportion of polymorphonuclear neutrophils (PMNs) (p=0.07) and epithelial cells (p=0.05) in BAL fluid. This was accompanied by increased concentrations of IL-8 (p=0.01), Gro-alpha (p=0.05) and total protein (p=0.058). A significant positive correlation was demonstrated between the two chemokines and proportion of PMNs in BAL fluid. After ozone exposure there was a significant decrease in the CD4/CD8 ratio (p=0.05) and the proportion of activated CD4+ (p=0.01) and CD8+ T-cells (p=0.04). However, no significant changes were demonstrable in any of the inflammatory markers studied in the biopsies. Short-term exposure of healthy humans to 0.2 ppm ozone induced a neutrophil influx in peripheral airways at 6 h post exposure, but no apparent inflammatory response in proximal airways. This response seems to be mediated at least in part by interleukin-8 and growth-related oncogene-alpha.     

Effect of antacid on bioavailability of a sustained-release theophylline preparation

The effect of coadministration of an antacid on bioavailability of a sustained-release theophylline tablet preparation (Theo-Dur) was studied by crossover comparison in five young, healthy, nonsmoking volunteers. Water 90 ml, or "high potency" aluminum-magnesium hydroxide antacid (Mylanta II) 10 ml and water 80 ml were administered concurrently with sustained-release theophylline 600 mg. Eleven blood samples were collected over the next 24 hours. Serum was analyzed with high pressure liquid chromatography technique to determine theophylline concentration. Peak serum concentration (Cmax) and time to peak concentration (tmax) were determined, and area under the 24-hour serum concentration-time curve (AUC) was calculated by the trapezoidal rule for each subject at each study interval. The Student's paired t-test was used to compare Cmax, tmax, and AUC for both treatments. A uniform difference was found between groups in Cmax. Cmax was higher in subjects when treated with the antacid (10.45 +/- 3.03 vs. 8.30 +/- 2.90 micrograms/ml, p less than 0.05) than when given theophylline alone. The mean tmax for the two treatments did not differ (10.4 +/- 1.67 h-combination vs. 10.8 +/- 1.1 h-theophylline, p greater than 0.05). Likewise, mean AUC was unchanged by the coadministration of antacid (140.65 +/- 41.6 micrograms/ml.h--combination vs. 155.13 +/- 46.6 micrograms/h--theophylline, p greater than 0.05). The use of a high-potency antacid product did not decrease the extent of theophylline absorption from this sustained-release product, but did increase Cmax and, presumably, rate of absorption. High-potency aluminum-magnesium antacids can probably be used in combination with this sustained-release theophylline tablet without detriment to therapy.     

Analysis of intact tissue by intermediate-pressure MALDI on a linear ion trap mass spectrometer

The use of an intermediate-pressure matrix-assisted laser desorption/ionization (IP-MALDI) source working at 0.17 Torr on a linear ion trap (LIT) was investigated for the analysis of tissue specimens, in particular, spinal cord sections. MALDI, with 2,5-dihydroxybenzoic acid (DHB) as the matrix, was employed for the detection of phospholipids. The matrix was applied to the tissue using electrospray to avoid analyte migration. The results indicate that analyzing tissue specimens at nontraditional MALDI vacuum pressures is possible. Coupling MALDI to an LIT permits the use of MSn, which is critical for the ability to identify compounds desorbed directly from tissue specimens. Using MSn, ions detected from m/z 600-1000 were characterized as phosphatidlycholines, PC. Specifically, using tandem MS, PC ions could be classified as either [M + H]+ or [M + Na]+ because the fragmentation patterns of protonated and sodiated phosphatidlycholines follow different pathways.     

Evaluation of the ability of lysozyme and nisin to control meat spoilage bacteria.

The antimicrobials lysozyme, nisin, and mixtures of the two were studied to ascertain their abilities to control the growth of the meat-borne spoilage bacteria, Brochothrix thermosphacta B2 and Carnobacterium sp. 845. The goal was to optimize an antimicrobial for potential use in preservation of fresh meats. Their efficacies were evaluated in APT broth, in a meat juice extract and on cores of lean and fat pork tissue. Both lysozyme and nisin alone as well as mixtures of the two effectively inhibited B. thermosphacta B2 at 250 microg/ml in APT broth, the lowest concentration evaluated, for 10 days at 2 degrees C. In the presence of 500 microg/ml lysozyme, B. thermosphacta B2 grew after 12 days incubation. Only 125 microg of antimicrobial/ml was required to inhibit B. thermosphacta B2 for 27 days at 2 degrees C in pork juice. An estimated surface concentration of 130 microg/cm2 of each of the antimicrobials effectively inhibited B. thermosphacta B2 on inoculated cores of fat and lean pork tissue when the cores were incubated in vacuum packages for 6 weeks at 2 degrees C. In APT broth and in pork juice, lysozyme showed no antimicrobial activity against Carnobacterium sp. 845 at concentrations of 500 and 1000 microg/ml, respectively. Nisin and mixtures of the two antimicrobials inhibited Carnobacterium sp. 845 so that its numbers were at least 3 log units lower than untreated samples after 26 and 27 days incubation for APT and pork juice, respectively. The antimicrobial effect was concentration dependent. On lean pork tissue, numbers of Carnobacterium sp. 845 were significantly lower than untreated samples or samples treated with 195 microg/cm2 lysozyme when 260 microg/cm2 of a 1:3 (w/w) ratio of nisin to lysozyme was introduced to the cores. The inhibitory effect lasted for 14 of 42 days incubation in vacuum at 2 degrees C. On fat tissue, both lysozyme alone and the 1:3 nisin/lysozyme mixture inhibited Carnobacterium sp. 845 for 21 days storage in vacuum at 2 degrees C. On fat and lean tissue, mixtures of nisin and lysozyme would be more effective antimicrobials than either nisin or lysozyme alone.     

Relationship between Redox Potential and pH on RDX Transformation in Soil-Water Slurries

The presence of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) in surface soil, the vadose zone, and ground water can present serious environmental problems. The processes governing the release and transformation of RDX into soils and the aquatic environment are not well understood. The objective of this study was to determine the effects of differing environmental conditions as reflected by redox potential and pH on the fate of RDX in soil. Laboratory investigations consisted of testing three redox potentials and four pH levels in an 18:1 (2,600 m3 water:150 g soil) suspension spiked with 10 mg∕L RDX. Results indicated that RDX was unstable under highly reducing conditions (?150 mV) and relatively stable over the short term (15 days) under oxidizing and moderately reducing conditions at all pH values. RDX in areas of intense reduction would not persist. However, RDX deposited or moving into areas under moderately reducing or oxidizing conditions would be highly mobile and persistent.     

Power dissipation in clocking wires for clocked molecular quantum-dot cellular automata

In the molecular quantum-dot cellular automata (QCA) paradigm clocking wires are used to produce an electric field which is perpendicular to the device plane of surface-bound molecules and is sinusoidally modulated in space and time. This clocking field guides the data flow through the molecular QCA array. Power is dissipated in clocking wires due to the non-zero resistance of the conductors. We analyze quantitatively the amount of power dissipated in the clocking wires and find that in the relevant parameter range it is fairly small. Dissipation in the molecular devices themselves will likely dominate the energy budget.     

Effect of copper source and level on the rate and extent of copper repletion in Holstein heifers

The objective of this study was to evaluate the rate and extent of Cu repletion in Holstein heifers using two Cu sources (organic and inorganic) at two levels (15 and 30 mg/kg). An additional repletion treatment included a Cu oxide bolus. Heifers (n = 50) were individually fed a total mixed ration fortified with S and Mo at 0.40%, and 15 mg/kg of dry matter of the total diet, respectively. After 111 d of depletion, heifers were stratified by liver Cu concentration and randomly allotted to one of five repletion treatments. Four treatments consisted of feed sources of Cu (feed-Cu), 1) CuSO4 at 15 mg/kg; 2) CuSO4 at 30 mg/kg; 3) Availa-Cu at 15 mg/kg; and 4) Availa-Cu at 30 mg/kg. Availa-Cu is an organic Cu source that produces a Cu-amino acid complex. A fifth treatment, consisting of an intraruminal bolus (IB), provided a single dose of 25 g of CuO needles. Repletion treatments were delivered in the same total mixed ration without supplemental S and Mo. Copper status was assessed in blood and liver samples collected on 14-d intervals for 70 d. Irrespective of treatment, all heifers increased in body weight during the repletion period. Liver Cu increased in each feed-Cu treatment over time. Heifers treated with an IB reached a peak in liver Cu concentration (165.5 mg/kg) on d 28. Mean liver Cu concentrations were higher in heifers receiving 30 mg/kg of Cu compared with heifers receiving 15 mg/kg of Cu. Red blood cell superoxide dismutase (SOD) activity was higher (P < 0.001) in heifers receiving CuSO4 than Availa-Cu (0.98 vs 0.87 U). Also, SOD activity was higher when heifers were supplemented with 30 vs 15 mg/kg Cu (0.98 vs 0.87 U). Heifers receiving the Cu IB had higher SOD activity than heifers receiving feed-Cu sources (1.03 vs 0.92 U). Plasma ceruloplasmin concentration was higher (P < 0.001) in IB-treated heifers vs. other treatments. No differences in plasma ceruloplasmin were detected for feed-Cu source or level. These results indicate that all Cu sources evaluated in this study elevated Cu status of depleted heifers, particularly when provided at higher dietary levels.