Hydrogen turbine power conversion system assessment

A three part technical study was conducted whereby parametric technical and economic feasibility data were developed on several power conversion systems suitable for the generation of central station electric power through the combustion of hydrogen and the use of the resulting heat energy in turbogenerator equipment. The study assessed potential applications of hydrogen-fueled power conversion systems and identified the three most promising candidates: (1) Ericsson Cycle, (2) gas turbine, and (3) direct steam injection system for fossil fuel as well as nuclear powerplants. A technical and economic evaluation was performed on the three systems from which the direct injection system (fossil fuel only) was selected for a preliminary conceptual design of an integrated hydrogen-fired power conversion system

Luteal Blood Flow and progesterone concentration during first and second postpartum estrous cycle in lactating dairy cows

The aim of the present study was to determine the differences in corpus luteum (CL) functionality between the first postpartum estrous cycle and the following cycle in lactating dairy cows. Luteal blood flow (LBF), luteal size and blood progesterone (P4) concentration were monitored during the first and second postpartum estrous cycle. During the first and second postpartum estrous cycle, the mean LBF value increased (p < .05) from early to late dioestrus, while it decreased rapidly in proestrus, resulting statistically lower (p < .05) than those registered in all previous phases. Statistically significant differences were not observed between overall LBF during first and second postpartum estrous cycle (p > .05). During the first postpartum estrous cycle, P4 blood concentrations showed a significant reduction (p < .05) from dioestrus to proestrus. A different trend of P4 concentrations was observed during the second postpartum estrous cycle, where mean P4 value registered in proestrus resulted statistically lower than those registered in the previous cycle phases (p < .05). The mean P4 concentration registered over the first postpartum estrous cycle resulted statistically lower (p < .05) than that registered during the second one. A significant correlation between P4 concentrations and LBF was registered only during the second postpartum estrous cycle. Results indicate that during the first postpartum estrous cycle, P4 concentration was independent of luteal blood flow and luteal size

Prehistory at high altitude. New surveys in the central-southern Apennines

The ‘Molise Survey Project’ aims, through systematic survey, to document evidence for the prehistoric occupation and exploitation of the Apennine Mountains. Here, we present some of the first results of the archaeological surveys, with a focus on the evidence from the Middle Palaeolithic to the Bronze Age

High Gain Compact Strip and Slot UWB Sinuous Antennas

Three ground-backed compact strip-and slot-sinuous antennas are analyzed. Proposed configuration allows for a single lobe, polarization-versatile, high efficiency, and ultrawide band antenna not needing a cumbersome lossy back cavity typical of conventional single-lobe sinuous antennas. Simulations show attained performances as well as tuning possibilities

Valorisation productive de zones dégradées à l'aide de plantations forestières : un exemple d'expérimentation en Sardaigne.

Décrit des interventions expérimentales réalisées en 1986-87 en Sardaigne afin de : - identifier les espèces forestières appropriées - mettre au point des techniques de préparation appropriées

Improved method for determination of waxes in olive oils: Reduction of silica and use of a less hazardous solvent

The evaluation of the content of waxes is request both by IOC Trade Standard and by Regulation (EEC) 2568/91 and its further amendments. The official method uses 15 g of silicic acid and elutes several fractions by using huge volumes of dangerous solvent (n-hexane). The developed method uses 1 g of silicic acid with a different particle size and less than 20 mL of solvent mixture, substituting n-hexane with less toxic isooctane. Briefly, after spiking with a suitable internal standard, oil sample is fractionated by SPE (Solid Phase Extraction) cartridge with 1 g of silica, waxes are eluted with 14 mL of isooctane/ethyl ether 99/1 (6 mL discarded and 8 mL collected), then, after elution sample is reconstitute in 200 \u3bcL of n-heptane and analysed by capillary GC. Data of "In home" validation, (repeatability, accuracy and recovery) and relative chromatograms are reported in this paper

Atomic force microscopy techniques for nanomechanical characterization : a polymer case study

Atomic force microscopy (AFM) is a versatile tool to perform mechanical characterization of surface samples at the nanoscale. In this work, we review two of such methods, namely contact resonance AFM (CR-AFM) and torsional harmonics AFM (TH-AFM). First, such techniques are illustrated and their applicability on materials with elastic moduli in different ranges are discussed, together with their main advantages and limitations. Then, a case study is presented in which we report the mechanical characterization using both CR-AFM and TH-AFM of polyaniline and polyaniniline doped with nanodiamond particles tablets prepared by a pressing process. We determined the indentation modulus values of their surfaces, which were found in fairly good agreement, thus demonstrating the accuracy of the techniques. Finally, the determined surface elastic moduli have been compared with the bulk ones measured through standard indentation testing. INTRODUCTION In the field of nanotechnology, the development of innovative and nondestructive characterization techniques plays a crucial role. Indeed, the characterization of nanostructured hybrid materials (e.g., thin films and nanocomposites) and devices requires the capability of acquiring maps of the local mechanical properties at the nanoscale. Nanoindentation is the most common method for determining the mechanical properties of thin films. However, its applicability is strictly limited by the thickness of the sample. Furthermore, its poor spatial resolution does not allow the reconstruction of an accurate distribution of the sample surface mechanical properties. For this reason, alternative methods, based on atomic force microscopy (AFM), have been developed. By exploiting the high resolution of the AFM, maps of the surface mechanical properties (i.e., indentation modulus) can be achieved. Among these techniques, AFM nanoindentation1 is the simplest method used to evaluate the local mechanical properties o

Paper Session I-C - Meteorological Support to Assure Safe Access to Space

On March 26, 1987 an Atlas Centaur rocket (AC-67) carrying a Navy communications satellite was given a green light for launch by Cape Canaveral Range Weather. There were rain-showers in the area. By the time liftoff occurred, one had moved over the launch complex. AC-67 ascended into a heavy shower where the plume of ionized exhaust gasses assisted in triggering a lightning strike...a deadly conduit to an electrically-charged atmosphere. The boosterÕs guidance system was fried and the rocket veered off course. To protect the public, the rocket was destroyed by the range safety officer (RSO). The accident cost taxpayers $250 million. A cloud quite literally formed over Air Force weather support to the space program. The good news is in the subsequent 10 years, the Department of Defense, in concert with universities and national laboratories, learned a great deal about how to prevent this kind of incident from happening again. As a result, the record since AC-67 has been flawless

Post-hatching development of bovine embryos in vitro: the effects of tunnel preparation and gender.

The objective of this study was to compare morphological characteristics, kinetics of development, and gene expression ofmale and female IVP embryos thatwere cultured until day (D)15 (fertilization = D0), using either phosphate-buffered saline (PBS) or Milli-Q water (MQW) to dilute the agarose gel used for tunnel construction. On D11, embryos (n = 286) were placed in agarose gel tunnels diluted in PBS and MQW. Embryos were evaluated for morphology, and embryo size was recorded on D11, D12.5, D14 and D15. Then, embryos were sexed and used for gene expression analyses (G6PD, GLUT1, GLUT3, PGK1, PLAC8, KRT8, HSF1 and IFNT). The percentage of elongated embryos at D15 was higher (p < 0.05) in the PBS (54%) than in theMQW(42%) gel. However, embryos produced inMQWwere bigger (p < 0.05) and had a lower expression of GLUT1 (p = 0.08) than those cultured in PBS. There was a higher proportion of male than female embryos at D15 in both treatments, MQW(65% vs. 35%; p < 0.05) and PBS (67% vs. 33%; p < 0.05); however, embryo size was not signi?cantly different between genders. Moreover, D15 female embryos had greater expression of G6PD (p = 0.05) and KRT8 (p = 0.03) than male embryos. In conclusion, the diluent used for tunnel construction affected embryo development in the post-hatching development (PHD) system, and the use ofMQWwas the most indicative measure for the evaluation of embryo quality. Male and female embryos cultured from D11 to D15, either in an MQW or PBS agarose gel, demonstrated similar development but different gene expression