Area-based results for mine detection

The cost and the closely related length of time spent in searching for mines or unexploded ordnance (UXO) may well be largely determined by the number of false alarms. False alarms can result in time consuming digging of soil or in additional multisensory tests in the minefield. The authors consider two area-based methods for reducing false alarms. These are: (a) the previously known “declaration” technique and (b) the new δ technique, which they introduce. They first derive expressions and lower bounds for false-alarm probabilities as a function of declaration area and discuss their impact on receiver operation characteristic (ROC) curves. Second, they exploit characteristics of the statistical distribution of sensory energy in the immediate neighborhood of targets and of false alarms from available calibrated data, to propose the δ technique, which significantly improves discrimination between targets and false alarms. The results are abundantly illustrated with statistical data and ROC curves using electromagnetic-induction sensor data made available through DARPA from measurements at various calibrated sites     

Wall-to-particle heat transfer in steam reformer tubes: CFD comparison of catalyst particles

Computational fluid dynamics (CFD) was used to simulate non-reacting heat transfer in a steam reforming packed reactor tube of tube-to-particle diameter ratio (N) equal to 4, with cylindrical multi-hole catalyst particles. These simulations extend those of our previous study [Nijemeisland, M., Dixon, A.G., Stitt, E.H., 2004. Catalyst design by CFD for heat transfer and reaction in steam reforming. Chemical Engineering Science 59, 5185-5191] to provide accurate tube wall temperatures, runs at constant pressure drop in addition to those at constant mass flow rate and simulations of particles with different sizes of holes. At constant pressure drop, particles with higher void fractions allowed higher mass flow rates, resulting in tube wall temperatures and radial temperature profiles in order: solid cylinders>one-hole particles>multi-hole particles. Little difference was seen between three-hole and four-hole particles. The particles with multiple holes gave a substantial reduction in tube wall temperature, with only a small decrease in core tube heat transfer. The effect of hole size was small, for the cases investigated in this study.     

Composition of corrosion products and solid deposits in the flow path of the Verkhnemutnovsk geothermal power station

We present the results from an investigation of the physicochemical characteristics of samples taken from the corrosion products and solid deposits formed in the flow paths of geothermal power stations. The investigation was carried out using different methods, among which were an X-ray phase analysis, electronic microscopy, thermal gravimetry, and infrared and Mössbauer spectroscopy.     

Effect of salt crystallization on stones of historical buildings and monuments,Konya, Central Turkey

In this study, we investigated the chemical and physical properties of the volcanic rocks used as building stones in historical places and monuments. The chemical weathering effect of salt crystallization on these stones was measured on the laboratory conditions (in most cases, used samples were very small). For this purpose, the dry weight loss (DWL) test was conducted. The rocks of dacite, andesite and tuffs of volcanic origin have different durability against salt crystallization. The most stable rocks are dacites (DWL 2.06%) which were used in the construction of Hittite monuments at Eflatun. The durability of the stones is closely related to their chemical, mineralogical, petrographical and mechanical properties. The stones used in the historical buildings are generally much more stable than present-day building stones.     

Efficient production of l-lactic acid from chicken feather protein hydrolysate and sugar beet molasses by the newly isolated Rhizopus oryzae TS-61

The aim of this study was to investigate production of l-lactic acid from molasses and chicken feather protein hydrolysate (CFP) by the newly isolated Rhizopus oryzae TS-61. R. oryzae TS-61 was capable of utilizing molasses sucrose and CFP as carbon and nitrogen sources, respectively. In contrast to yeast extract and ammonium sulfate, CFP had potential not only to prevent excessive pH changes and foaming but also to provide smaller uniform pellet formation in during fermentation. Thanks to these properties, it was concluded that CFP might have resulted in higher l-lactic acid production than the other two nitrogen sources (yeast extract and ammonium sulfate). At the end of 42-h optimal cultivation period, the highest (38.5 g/L) and lowest (28.8 g/L) concentrations of l-lactic acid were obtained with CFP and ammonium sulfate, respectively. This is the first report on use of waste chicken feather as a lactic acid production substrate. In addition, a new R. oryzae strain, being capable of using molasses sucrose as carbon source in order to produce l-lactic acid, was isolated.     

Special features of spatial redistribution of selenium atoms implanted in silicon

The spatial distribution of selenium atoms implanted in silicon was studied by secondary-ion mass spectrometry after annealing in the temperature range of 600–1200°C. For implantation doses exceeding the amorphization dose for silicon, formation of a peak of selenium concentration was detected beyond the mean projected range of selenium ions. The spatial position of the peak correlates well with the spatial position of the plane in which the calculated value of the specific energy losses of selenium ions in elastic collisions (according to the TRIM code) corresponds to the critical value for amorphization of silicon. Accumulation of impurities at the peak occurs at temperatures of 700°C and higher after recrystallization of the amorphized layer. Redistribution of selenium atoms to deeper layers of the sample due to diffusion is controlled by the temperature dependence of the solubility of selenium in silicon.     

Using the Kramers-Kronig method to determine optical constants and evaluating its suitability as a linear transform for near-normal front-surface reflectance spectra

In this paper, the suitability of using the Kramers-Kronig transform to routinely extract optical constants from near-normal incidence reflectance spectra of solids and liquids is demonstrated. In addition, the possibility of utilizing the Kramers-Kronig transform as a linearizing transform for near-normal incidence reflectance spectra is investigated. Also, several commercial Kramers-Kronig software packages were utilized in determining the optical constants from the near-normal incidence reflectance of Plexiglas. Unexpectedly, the results produced by the various packages differed significantly. The near-normal reflectance of water was measured, the Kramers-Kronig transform was applied to extract the optical constants of water, and the result was compared to values found in the literature. Furthermore, the Kramers-Kronig transforms of near-normal incidence reflectance spectra of various concentrations of sugar in water were calculated to evaluate its use as a linearizing transform for quantitative applications.     

Prediction of earthquake damage to urban water distribution systems: a case study for Denizli,Turkey

Prediction of damage to water supply lines during an earthquake is a critical part of seismic planning. This study evaluates the performance of the water supply system in Denizli, Turkey, in the event of an M6, M6.3, M6.5 and M7 earthquake associated with the Pamukkale and Karakova-Akhan Faults. The relative effects of transient ground deformations and permanent ground deformations based on maps of liquefiable soil and zones of predicted lateral ground displacements are compared. The relative effects of the different magnitude earthquakes and pipeline damage relationships on the pipeline performance following a seismic event are assessed.