Laboratory Tests

In the nondestructive inspection of aerospace materials and structures, water-coupled ultrasonic inspection is often not desirable due to contamination and property alteration concerns. Examples include composite and foam structures in space applications and honeycomb sandwiches that cannot tolerate water ingression. For practical and operational reasons, water-coupled ultrasound is also not preferred for on-aircraft inspection in maintenance hangars. Non-contact, air-coupled ultrasonic transducers are therefore an attractive alternative for such applications. This paper describes our experience of using piezoceramic air-coupled transducers for flaw detection and repair evaluation of composite parts. The paper first discusses the basic principles of air-coupled ultrasonic measurement and laboratory tests of various materials and structures, followed by a description of a portable, manual, air-coupled ultrasonic scan system that allowed the use of air-coupled ultrasound in the field ...

The estimation of runout distances on fans has a major role in assessing debris-flow hazards. Different methods have been devised for this purpose: volume balance, limiting topographic methods, empirical equations, and physical approaches. Data collected from field observations are the basis for developing, testing, and improving predictive methods, while laboratory tests on small-scale models are another suitable approach for studying debris-flow runout under controlled conditions and for developing predictive equations. This paper analyses the problem of assessing runout distance, focusing on six debris flows that were triggered on July 5th, 2006 by intense rainfall near Cortina d'Ampezzo (Dolomites, north-eastern Italy). Detailed field surveys were carried out immediately after the event in the triggering zone, along the channels, and in the deposition areas. A fine-scale digital terrain model of the study area was established by aerial LiDAR measurements. Total travel and runout distances on fans measured in the field were compared with the results of formulae from the literature (empirical/statistical and physically oriented), and samples of sediment collected from deposition lobes were used for laboratory tests. The experimental device employed in the tests consists of a tilting flume with an inclination from 0° to 38°, on which a steel tank with a removable gate was installed at variable distances from the outlet. A final horizontal plane works as the deposition area. Samples of different volumes and variable sediment concentrations were tested. Multiple regression analysis was used to assess the length of the deposits as a function of both the potential energy of the mass and the sediment concentration of the flow. Our comparison of the results of laboratory tests with field data suggests that an energy-based runout formula might predict the runout distances of debris flows in the Dolomites.

To determine the possible association between anemia and clinical and echocardiographic cardiac disease, a cohort of 432 end-stage renal disease patients (261 on hemodialysis and 171 on peritoneal dialysis) who started dialysis therapy between 1982 and 1991 were followed prospectively for an average of 41 months. Baseline demographic, clinical, and echocardiographic assessments were performed, as well as monthly serial clinical and laboratory tests while the patients were on dialysis therapy. The mean (+/-SD) hemoglobin level during dialysis therapy was 8.8 +/- 1.5 g/dL. After adjusting for age, diabetes, and ischemic heart disease, as well as for blood pressure and serum albumin levels measured serially, each 1 g/dL decrease in mean hemoglobin was independently associated with the presence of left ventricular dilatation on repeat echocardiogram (odds ratio, 1.46; P = 0.018) and the development of de novo (relative risk [RR] = 1.28; P = 0.018) and recurrent (RR = 1.20; P = 0.046) cardiac failure. In addition, each 1 g/dL decrease in the mean hemoglobin level was independently associated with mortality while the patients were on dialysis therapy (RR = 1.14; P = 0.024). Anemia had no independent association with the development of ischemic heart disease while the patients were on dialysis therapy. Anemia, an easily reversible feature of end-stage renal disease, is an independent risk factor for clinical and echocardiographic cardiac disease, as well as mortality in end-stage renal disease patients.

This paper presents a small-scale, batch-type, technology for production of a natural extract which can be utilized as a food dye. This technology was designed based on the laboratory tests performed on Mougeotia sp. algae; it allows a simple way for processing the algal biomass into a valuable product for food industry, which is in the mean time an antioxidant and a food dye. The key steps involved in this process are saponification (with a solution of KOH in ethanol), extraction (with diethyl ether) and evaporation; the final product is an ethanolic extract rich in lutein, antheraxanthin and β-carotene, it’s carotenoid composition being established by high performance liquid chromatography analysis.

Landslides at continental margins are natural hazards for submarine installations and coastal regions. The occurrence of gas hydrates at continental margins is thought to be one major cause for these slides. It is assumed that the decomposition of gas hydrates increases the water content of the host sediment and thus lowers the strength of the soil. In order to predict

Human obesity is associated with greater-than-average energy intake, although relatively few studies have tested the heritability of food intake. The present study examined the genetic architecture of measured caloric intake during laboratory test meals in 36 monozygotic and 18 dizygotic twin pairs. A series of analyses tested the hypotheses that (1) there would be a genetic influence on total caloric intake,(2) there would be genes influencing total caloric intake above and beyond those influencing body composition,(3) ...

Body fluid traces recovered at crime scenes are among the most important types of evidence to forensic investigators. They contain valuable DNA evidence which can identify a suspect or victim as well as exonerate an innocent individual. The first step of identifying a particular body fluid is highly important since the nature of the fluid is itself very informative to the investigation, and the destructive nature of a screening test must be considered when only a small amount of material is available. The ability to characterize an unknown stain at the scene of the crime without having to wait for results from a laboratory is another very critical step in the development of forensic body fluid analysis. Driven by the importance for forensic applications, body fluid identification methods have been extensively developed in recent years. The systematic analysis of these new developments is vital for forensic investigators to be continuously educated on possible superior techniques. Significant advances in laser technology and the development of novel light detectors have dramatically improved spectroscopic methods for molecular characterization over the last decade. The application of this novel biospectroscopy for forensic purposes opens new and exciting opportunities for the development of on-field, non-destructive, confirmatory methods for body fluid identification at a crime scene. In addition, the biospectroscopy methods are universally applicable to all body fluids unlike the majority of current techniques which are valid for individual fluids only. This article analyzes the current methods being used to identify body fluid stains including blood, semen, saliva, vaginal fluid, urine, and sweat, and also focuses on new techniques that have been developed in the last 5-6 years. In addition, the potential of new biospectroscopic techniques based on Raman and fluorescence spectroscopy is evaluated for rapid, confirmatory, non-destructive identification of a body fluid at a crime scene.