Resolution improvement in two-photon fluorescence microscopy with a single-mode fiber

The dependence of spectral broadening of an ultrashort-pulsed laser beam on the fiber length and the illumination power is experimentally characterized in order to deliver the laser for two-photon fluorescence microscopy. It is found that not only the spectral width but also the spectral blue shift increases with the fiber length and illumination power, owing to the nonlinear response in the fiber. For an illumination power of 400 mW in a 3-m-long single-mode fiber, the spectral blue shift is as large as 15 nm. Such a spectral blue shift enhances the contribution from the short-wavelength components within the pulsed beam and leads to an improvement in resolution under two-photon excitation, whereas the efficiency of two-photon excitation is slightly reduced because of the temporal broadening of the pulsed beam. The experimental measurement of the axial response to a two-photon fluorescence polymer block confirms this feature.     

HTGR reactor physics and fuel cycle studies

The high-temperature gas-cooled reactor (HTGR) appears as a good candidate for the next generation of nuclear power plants. In the “HTR-N” project of the European Union Fifth Framework Program, analyses have been performed on a number of conceptual HTGR designs, derived from reference pebble-bed and hexagonal block-type HTGR types. It is shown that several HTGR concepts are quite promising as systems for the incineration of plutonium and possibly minor actinides.These studies were mainly concerned with the investigation and intercomparison of the plutonium and actinide burning capabilities of a number of HTGR concepts and associated fuel cycles, with emphasis on the use of civil plutonium from spent LWR uranium fuel (first generation Pu) and from spent LWR MOX fuel (second generation Pu). Besides, the “HTR-N” project also included activities concerning the validation of computational tools and the qualification of models. Indeed, it is essential that validated analytical tools are available in the European nuclear community to perform conceptual design studies, industrial calculations (reload calculations and the associated core follow), safety analyses for licensing, etc., for new fuel cycles aiming at plutonium and minor actinide (MA) incineration/transmutation without multi-reprocessing of the discharged fuel.These validation and qualification activities have been centred round the two HTGR systems currently in operation, viz. the HTR-10 and the HTTR. The re-calculation of the HTTR first criticality with a Monte Carlo neutron transport code now yields acceptable correspondence with experimental data. Also calculations by 3D diffusion theory codes yield acceptable results. Special attention, however, has to be given to the modelling of neutron streaming effects. For the HTR-10 the analyses focused on first criticality, temperature coefficients and control rod worth. Also in these studies a good correspondence between calculation and experiment is observed for the 3D diffusion theory codes.     

Analysis of emptiness (lacunarity) as a measure of the degree of space filling and of the internal structure of a set

The study presents a comparative evaluation of emptiness (lacunarity) in model structures with different types of inhomogeneity of dispersed particle distributions. The research on emptiness (lacunarity) as a measure of the degree of space filling and, at the same time, of the internal characterization of a set has been based on the optimal covering and gliding-box methods.     

The antisteroid action on the pineal gland

The study presents the data gathered along the years on the antisteroid action of the pineal gland. Thus, it was demonstrated that administration of pineal polypeptides to the rabbit lowers the urinary 17-KS both of testicular and adrenal origin. Conversely, pinealectomy caused an increase in the level of these steroid hormones. The same pineal material induced a marked decrease both in the serum and testicular testosterone and in the plasma and adrenal corticosterone in the rat. At the same time administration of pineal polypeptides lowered the cholesterol in the serum, bile, liver, testis and adrenal. Melatonin had no effect on these biochemical indices, which demonstrates that the effects obtained with pineal polypeptides are not mediated by melatonin.     

Semantic and syntactic forces in noun phrase production.

Three experiments investigated semantic and syntactic effects in the production of phrases in Dutch. Bilingual participants were presented with English nouns and were asked to produce an adjective + noun phrase in Dutch including the translation of the noun. In 2 experiments, the authors blocked items by either semantic category or grammatical gender. Participants performed the task slower when the target nouns were of the same semantic category than when they were from different categories and faster when the target nouns had the same gender than when they had different genders. In a final experiment, both manipulations were crossed. The authors replicated the results of the first 2 experiments, and no interaction was found. These findings suggest a feedforward flow of activation between lexico-semantic and lexico-syntactic information. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Experimental determination of the absorbed dose to water in a scanned proton beam using a water calorimeter and an ionization chamber

The absorbed dose to water is the reference physical quantity for the energy absorbed in tissue when exposed to beams of ionizing radiation in radiotherapy. The SI unit of absorbed dose to water is the gray (Gy = 1 J/kg). Ionization chambers are used as the dosimeters of choice in the clinical environment because they show a high reproducibility and are easy to use. However, ionization chambers have to be calibrated in order to convert the measured electrical charge into absorbed dose to water. In addition, protocols require these conversion factors to be SI traceable to a primary standard of absorbed dose to water. We present experimental results where the ionization chamber used for the dosimetry for the scanned proton beam facility at PSI is compared with the direct determination of absorbed dose to water from the METAS primary standard water calorimeter. The agreement of 3.2% of the dose values measured by the two techniques are within their respective statistical uncertainties.     

Design and optimization of small hydropower systems in water distribution networks under consideration of rehabilitation measures

Small hydro power systems (SHPSs) are increasingly installed in water distribution systems (WDSs). With only minor adaptations in a WDS, pressure surplus can be utilised. In such systems, a water surplus is also often available. In this work, water consumption data of a real Alpine WDS over one year are used as an input for an Epanet2 long-term simulation model to assess such a SHPS. In addition, the combinations of pressure and water surplus devices in a WDS are investigated. For such a specific investigated case, the yearly profit of 1750 € for a single SHPS could be increased to 3550 € when combining two interacting devices. Further, necessary and upcoming rehabilitation measures are investigated concerning their positive impact on the energy production potential and how additional costs (e.g., higher diameters (200 mm instead of 125 mm)) can be compensated by additional profits from energy production (maximum 5250 € per year).     

Yttrium incorporation in Cr2AlC: On the metastable phase formation and decomposition of (Cr,Y)2AlC MAX phase thin films

Herein we report on the synthesis of a metastable (Cr,Y)₂AlC MAX phase solid solution by co-sputtering from a composite Cr–Al–C and elemental Y target, at room temperature, followed by annealing. However, direct high-temperature synthesis resulted in multiphase films, as evidenced by X-ray diffraction analyses, room-temperature depositions, followed by annealing to 760°C led to the formation of phase pure (Cr,Y)₂AlC by diffusion. Higher annealing temperatures caused a decomposition of the metastable phase into Cr₂AlC, Y₅Al₃, and Cr-carbides. In contrast to pure Cr₂AlC, the Y-containing phase crystallizes directly in the MAX phase structure instead of first forming a disordered solid solution. Furthermore, the crystallization temperature was shown to be Y-content dependent and was increased by ∼200°C for 5 at.% Y compared to Cr₂AlC. Calculations predicting the metastable phase formation of (Cr,Y)₂AlC and its decomposition are in excellent agreement with the experimental findings.     

马尼托瓦克移动式起重机专用KZ~(TM)100型缆绳

正在CONEXPO-CON/AGG 2014上,马尼托瓦克展示了配备KZT~(TM)100型缆绳的Grove RT770E型起重机。KZ~(TM)100型缆绳是首次专为移动式起重机设计的合成纤维卷扬缆绳,这项创新成果由马尼托瓦克携手合成纤维缆绳制造商Samson公司共同研制,由马尼托瓦克独家销售,从2014年下半年开始作为Grove系列越野起重机的选购件供应给客户。KZ~(TM)100型卷扬缆绳具有许多优点:质量比钢丝绳轻80%:采用转矩中性平衡结构,可消除负荷旋转和缆绳缠绕