810 resultados para Girders -- Testing


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The aims of this study were to determine whether responses in myocardial blood flow (MBF) to the cold pressor testing (CPT) method noninvasively with PET correlate with an established and validated index of flow-dependent coronary vasomotion on quantitative angiography. METHODS: Fifty-six patients (57 +/- 6 y; 16 with hypertension, 10 with hypercholesterolemia, 8 smokers, and 22 without coronary risk factors) with normal coronary angiograms were studied. Biplanar end-diastolic images of a selected proximal segment of the left anterior descending artery (LAD) (n = 27) or left circumflex artery (LCx) (n = 29) were evaluated with quantitative coronary angiography in order to determine the CPT-induced changes of epicardial luminal area (LA, mm(2)). Within 20 d of coronary angiography, MBF in the LAD, LCx, and right coronary artery territory was measured with (13)N-ammonia and PET at baseline and during CPT. RESULTS: CPT induced on both study days comparable percent changes in the rate x pressure product (%DeltaRPP, 37% +/- 13% and 40% +/- 17%; P = not significant [NS]). For the entire study group, the epicardial LA decreased from 5.07 +/- 1.02 to 4.88 +/- 1.04 mm(2) (DeltaLA, -0.20 +/- 0.89 mm(2)) or by -2.19% +/- 17%, while MBF in the corresponding epicardial vessel segment increased from 0.76 +/- 0.16 to 1.03 +/- 0.33 mL x min(-1) x g(-1) (DeltaMBF, 0.27 +/- 0.25 mL x min(-1) x g(-1)) or 36% +/- 31% (P <or= 0.0001). However, in normal controls without coronary risk factors (n = 22), the epicardial LA increased from 5.01 +/- 1.07 to 5.88 +/- 0.89 mm(2) (19.06% +/- 8.9%) and MBF increased from 0.77 +/- 0.16 to 1.34 +/- 0.34 mL x min(-1) x g(-1) (74.08% +/- 23.5%) during CPT, whereas patients with coronary risk factors (n = 34) revealed a decrease of epicardial LA from 5.13 +/- 1.48 to 4.24 +/- 1.12 mm(2) (-15.94% +/- 12.2%) and a diminished MBF increase (from 0.76 +/- 0.20 to 0.83 +/- 0.25 mL x min(-1) x g(-1) or 10.91% +/- 19.8%) as compared with controls (P < 0.0001, respectively), despite comparable changes in the RPP (P = NS). In addition, there was a significant correlation (r = 0.87; P <or= 0.0001) between CPT-related percent changes in LA on quantitative angiography and in MBF as measured with PET. CONCLUSION: The observed close correlation between an angiographically established parameter of flow-dependent and, most likely, endothelium-mediated coronary vasomotion and PET-measured MBF further supports the validity and value of MBF responses to CPT as a noninvasively available index of coronary circulatory function.

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Purpose. The aim of this study was to identify new surfactants with low skin irritant properties for use in pharmaceutical and cosmetic formulations, employing cell culture as an alternative method to in vivo testing. In addition, we sought to establish whether potential cytotoxic properties were related to the size of the counterions bound to the surfactants. Methods. Cytotoxicity was assessed in the mouse fibroblast cell line 3T6, and the human keratinocyte cell line NCTC 2544, using the MTT assay and uptake of the vital dye neutral red 24 h after dosing (NRU). Results. Lysine-derivative surfactants showed higher IC50s than did commercial anionic irritant compounds such as sodium dodecyl sulphate, proving to be no more harmful than amphoteric betaines. The aggressiveness of the surfactants depended upon the size of their constituent counterions: surfactants associated with lighter counterions showed a proportionally higher aggressivity than those with heavier ones. Conclusions. Synthetic lysine-derivative anionic surfactants are less irritant than commercial surfactants such as sodium dodecyl sulphate and Hexadecyltrimethylammonium bromide and are similar to Betaines. These surfactants may offer promising applications in pharmaceutical and cosmetic preparations, representing a potential alternative to commercial anionic surfactants as a result of their low irritancy potential.

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The present research project was designed to identify the typical Iowa material input values that are required by the Mechanistic-Empirical Pavement Design Guide (MEPDG) for the Level 3 concrete pavement design. It was also designed to investigate the existing equations that might be used to predict Iowa pavement concrete for the Level 2 pavement design. In this project, over 20,000 data were collected from the Iowa Department of Transportation (DOT) and other sources. These data, most of which were concrete compressive strength, slump, air content, and unit weight data, were synthesized and their statistical parameters (such as the mean values and standard variations) were analyzed. Based on the analyses, the typical input values of Iowa pavement concrete, such as 28-day compressive strength (f’c), splitting tensile strength (fsp), elastic modulus (Ec), and modulus of rupture (MOR), were evaluated. The study indicates that the 28-day MOR of Iowa concrete is 646 + 51 psi, very close to the MEPDG default value (650 psi). The 28-day Ec of Iowa concrete (based only on two available data of the Iowa Curling and Warping project) is 4.82 + 0.28x106 psi, which is quite different from the MEPDG default value (3.93 x106 psi); therefore, the researchers recommend re-evaluating after more Iowa test data become available. The drying shrinkage (εc) of a typical Iowa concrete (C-3WR-C20 mix) was tested at Concrete Technology Laboratory (CTL). The test results show that the ultimate shrinkage of the concrete is about 454 microstrain and the time for the concrete to reach 50% of ultimate shrinkage is at 32 days; both of these values are very close to the MEPDG default values. The comparison of the Iowa test data and the MEPDG default values, as well as the recommendations on the input values to be used in MEPDG for Iowa PCC pavement design, are summarized in Table 20 of this report. The available equations for predicting the above-mentioned concrete properties were also assembled. The validity of these equations for Iowa concrete materials was examined. Multiple-parameters nonlinear regression analyses, along with the artificial neural network (ANN) method, were employed to investigate the relationships among Iowa concrete material properties and to modify the existing equations so as to be suitable for Iowa concrete materials. However, due to lack of necessary data sets, the relationships between Iowa concrete properties were established based on the limited data from CP Tech Center’s projects and ISU classes only. The researchers suggest that the resulting relationships be used by Iowa pavement design engineers as references only. The present study furthermore indicates that appropriately documenting concrete properties, including flexural strength, elastic modulus, and information on concrete mix design, is essential for updating the typical Iowa material input values and providing rational prediction equations for concrete pavement design in the future.

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An ammonium chloride procedure was used to prepare a bacterial pellet from positive blood cultures, which was used for direct inoculation of VITEK 2 cards. Correct identification reached 99% for Enterobacteriaceae and 74% for staphylococci. For antibiotic susceptibility testing, very major and major errors were 0.1 and 0.3% for Enterobacteriaceae, and 0.7 and 0.1% for staphylococci, respectively. Thus, bacterial pellets prepared with ammonium chloride allow direct inoculation of VITEK cards with excellent accuracy for Enterobacteriaceae and a lower accuracy for staphylococci.

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Construction of portland cement concrete pavements is a complex process. A small fraction of the concrete pavements constructed in the United States over the last few decades have either failed prematurely or exhibited moderate to severe distress. In an effort to prevent future premature failures, 17 state transportation agencies pooled their resources, and a pooled fund research project, Material and Construction Optimization for Prevention of Premature Pavement Distress in PCC Pavements, was undertaken in 2003. Its purpose was to evaluate existing quality control tests, and then select and advance the state-of-the-practice of those tests most useful for optimizing concrete pavements during mix design, mix verification, and construction. This testing guide is one product of that project. The guide provides three recommended testing schemes (Levels A, B, and C, depending on a pavement’s design life and traffic volumes, etc.) that balance the costs of testing with the risk of failure for various project types. The recommended tests are all part of a comprehensive suite of tests described in detail in this guide.

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The importance of rapid construction technologies has been recognized by the Federal Highway Administration (FHWA) and the Iowa DOT Office of Bridges and Structures. Black Hawk County (BHC) has developed a precast modified beam-in-slab bridge (PMBISB) system for use with accelerated construction. A typical PMBISB is comprised of five to six precast MBISB panels and is used on low volume roads, on short spans, and is installed and fabricated by county forces. Precast abutment caps and a precast abutment backwall were also developed by BHC for use with the PMBISB. The objective of the research was to gain knowledge of the global behavior of the bridge system in the field, to quantify the strength and behavior of the individual precast components, and to develop a more time efficient panel-to-panel field connection. Precast components tested in the laboratory include two precast abutment caps, three different types of deck panel connections, and a precast abutment backwall. The abutment caps and backwall were tested for behavior and strength. The three panel-to-panel connections were tested in the lab for strength and were evaluated based on cost and constructability. Two PMBISB were tested in the field to determine stresses, lateral distribution characteristics, and overall global behavior.

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In response to the mandate on Load and Resistance Factor Design (LRFD) implementations by the Federal Highway Administration (FHWA) on all new bridge projects initiated after October 1, 2007, the Iowa Highway Research Board (IHRB) sponsored these research projects to develop regional LRFD recommendations. The LRFD development was performed using the Iowa Department of Transportation (DOT) Pile Load Test database (PILOT). To increase the data points for LRFD development, develop LRFD recommendations for dynamic methods, and validate the results ofLRFD calibration, 10 full-scale field tests on the most commonly used steel H-piles (e.g., HP 10 x 42) were conducted throughout Iowa. Detailed in situ soil investigations were carried out, push-in pressure cells were installed, and laboratory soil tests were performed. Pile responses during driving, at the end of driving (EOD), and at re-strikes were monitored using the Pile Driving Analyzer (PDA), following with the CAse Pile Wave Analysis Program (CAPWAP) analysis. The hammer blow counts were recorded for Wave Equation Analysis Program (WEAP) and dynamic formulas. Static load tests (SLTs) were performed and the pile capacities were determined based on the Davisson’s criteria. The extensive experimental research studies generated important data for analytical and computational investigations. The SLT measured loaddisplacements were compared with the simulated results obtained using a model of the TZPILE program and using the modified borehole shear test method. Two analytical pile setup quantification methods, in terms of soil properties, were developed and validated. A new calibration procedure was developed to incorporate pile setup into LRFD.

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Asphalt wearing surfaces are commonly used on timber bridges with transverse glued-laminated deck panel systems to help protect the timber components. However, poor performance of these asphalt wearing surfaces in the past has resulted in repeated repair and increased maintenance costs. This report describes the field demonstration and testing of a newly-constructed, glued-laminated timber girder bridge. Previous field work revealed that differential panel deflections in the glued-laminated deck were one significant factor resulting in the premature failure of the asphalt wearing surfaces on these bridges. In addition, laboratory work subsequent to the field testing attempted to address the problematic asphalt cracking common in transverse glued-laminated panel decks by testing several deck joint connection alternatives. The field demonstration project described in this report showcases the retrofit detail that was determined to provide the best field performance. The project was a cooperative effort between the Bridge Engineering Center (BEC) at Iowa State University and the United States Department of Agriculture (USDA) Forest Service Forest Products Laboratory (FPL).

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This report outlines the current drug testing practices, guidelines, programs and initiatives as currently implemented by the Department regarding the process for drug testing of a person responsible for the care of a child in child abuse cases.

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In this paper we deal with the identification of dependencies between time series of equity returns. Marginal distribution functions are assumed to be known, and a bivariate chi-square test of fit is applied in a fully parametric copula approach. Several families of copulas are fitted and compared with Spanish stock market data. The results show that the t-copula generally outperforms other dependence structures, and highlight the difficulty in adjusting a significant number of bivariate data series

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PURPOSE: To select and propose a set of knowledge, attitudes, and skills essential for the care of adolescents; to encourage the development of adolescent health multidisciplinary networks; and to set up training programs in as many European countries as possible. METHODS: The curriculum was developed by 16 physicians from 11 European countries with various professional specializations. In line with modern guidelines in medical education, it is a modular, flexible instrument which covers the main teaching areas in the field, such as basic skills (i.e. setting, rights and confidentiality, gender and cultural issues) as well as specific themes (i.e. sexual and reproductive health, eating disorders, chronic conditions). It consists of 17 thematic modules, each containing detailed objectives, learning approaches, examples, and evaluation methods. RESULT: Two international one-week summer schools were used to assess the feasibility and appropriateness of the curriculum. The overall evaluation was good, with most of the items surpassing three on a four-point Likert scale. However, it pointed to several aspects (process and content) which will need to be refined in the future, such as an increase in interactive sessions (role playing), and a better mix of clinical and public health issues.

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Carbon isotope ratio (CIR) analysis has been routinely and successfully applied to doping control analysis for many years to uncover the misuse of endogenous steroids such as testosterone. Over the years, several challenges and limitations of this approach became apparent, e.g., the influence of inadequate chromatographic separation on CIR values or the emergence of steroid preparations comprising identical CIRs as endogenous steroids. While the latter has been addressed recently by the implementation of hydrogen isotope ratios (HIR), an improved sample preparation for CIR avoiding co-eluting compounds is presented herein together with newly established reference values of those endogenous steroids being relevant for doping controls. From the fraction of glucuronidated steroids 5β-pregnane-3α,20α-diol, 5α-androst-16-en-3α-ol, 3α-Hydroxy-5β-androstane-11,17-dione, 3α-hydroxy-5α-androstan-17-one (ANDRO), 3α-hydroxy-5β-androstan-17-one (ETIO), 3β-hydroxy-androst-5-en-17-one (DHEA), 5α- and 5β-androstane-3α,17β-diol (5aDIOL and 5bDIOL), 17β-hydroxy-androst-4-en-3-one and 17α-hydroxy-androst-4-en-3-one were included. In addition, sulfate conjugates of ANDRO, ETIO, DHEA, 3β-hydroxy-5α-androstan-17-one plus 17α- and androst-5-ene-3β,17β-diol were considered and analyzed after acidic solvolysis. The results obtained for the reference population encompassing n = 67 males and females confirmed earlier findings regarding factors influencing endogenous CIR. Variations in sample preparation influenced CIR measurements especially for 5aDIOL and 5bDIOL, the most valuable steroidal analytes for the detection of testosterone misuse. Earlier investigations on the HIR of the same reference population enabled the evaluation of combined measurements of CIR and HIR and its usefulness regarding both steroid metabolism studies and doping control analysis. The combination of both stable isotopes would allow for lower reference limits providing the same statistical power and certainty to distinguish between the endo- or exogenous origin of a urinary steroid.

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Abstract: Angelo Panebianco's institutionalizationhypothesis : testing in nordic context