5,547 research outputs found
Probe-diverse ptythography
We propose an extension of ptychography where the target sample is scanned separately through several probes with distinct amplitude and phase profiles and a diffraction image is recorded for each probe and each sample translation. The resulting probe-diverse dataset is used to iteratively retrieve high-resolution images of the sample and all probes simultaneously. The method is shown to yield significant improvement in the reconstructed sample image compared to the image obtained using the standard single-probe ptychographic phase-retrieval scheme
PRELIMINARY MULTIDOMAIN MODELLING AND SIMULATION STUDY OF A HORIZONTAL AXIS WIND TURBINE (HAWT) TOWER VIBRATION
Renewable energy sources have gained much attention due to the recent energy crisis and the urge to get clean energy. Among the main options being studied, wind energy is a strong contender because of its reliability due to the maturity of the technology, good infrastructure and relative cost competitiveness. It is also interesting to note that there are physical limits to the potential height of a wind turbine tower since the mechanical structure of wind turbines are thus very flexible and tend to oscillate. This makes the design of wind turbines a demanding task. In this paper, the oscillation of a wind turbine tower due to imbalance in the masses of the blades is modeled in maplesim and the effect of the tower height on its oscillation was simulated. For a wind turbine with three rotor blades, two of which have masses of 10 kg, a mass moment of inertia of approximately 20 kg/m2 and one of the blades has a moment of inertia which is 1% less than the other blades. The simulation showed the most stable system for the most energy capture for this case study to be a rotor speed of 5.5rad/s at a height of 10m. At this angular frequency the deflection of the top of the wind turbine was approximately 1mm. Â http://dx.doi.org/10.4314/njt.v36i1.1
Orphan G protein-coupled receptors MrgA1 and MrgC11 are distinctively activated by RF-amide-related peptides through the G{alpha}q/11 pathway
MrgA1 and MrgC11 belong to a recently identified family of orphan G-protein coupled receptors, called mrgs (mas-related genes). They are only expressed in a specific subset of sensory neurons that are known to detect painful stimuli. However, the precise physiological function of Mrg receptors and their underlying mechanisms of signal transduction are not known. We therefore have screened a series of neuropeptides against human embryonic kidney (HEK) 293 cells that stably express either MrgA1 or MrgC11 to identify ligands and/or agonists. MrgA1- or MrgC11-specific agonists stimulated dose-dependent increases in intracellular free Ca2+ in a pertussis toxin-insensitive manner, but failed to alter basal or forskolin-stimulated levels of intracellular cAMP. Furthermore, studies using embryonic fibroblasts derived from various G{alpha} protein knockout mice demonstrated that both the MrgA1 and MrgC11 receptors are coupled to the G{alpha}q/11 signaling pathway. Screening of neuropeptides identified surrogate agonists, most of these peptides included a common C-terminal -RF(Y)G or -RF(Y) amide motif. Structure-function studies suggest that endogenous ligands of Mrg receptors are likely to be RF(Y)G and/or RF(Y) amide-related peptides and that postprocessing of these peptides may serve to determine Mrg receptor-ligand specificity. The differences in ligand specificity also suggest functional diversity amongst the Mrg receptors
Developing a Molecular Roadmap of Drug-Food Interactions
Recent research has demonstrated that consumption of food -especially fruits and vegetables- can alter the effects of drugs by interfering either with their pharmacokinetic or pharmacodynamic processes. Despite the recognition of such drug-food associations as an important element for successful therapeutic interventions, a systematic approach for identifying, predicting and preventing potential interactions between food and marketed or novel drugs is not yet available. The overall objective of this work was to sketch a comprehensive picture of the interference of ∼ 4,000 dietary components present in ∼1800 plant-based foods with the pharmacokinetics and pharmacodynamics processes of medicine, with the purpose of elucidating the molecular mechanisms involved. By employing a systems chemical biology approach that integrates data from the scientific literature and online databases, we gained a global view of the associations between diet and dietary molecules with drug targets, metabolic enzymes, drug transporters and carriers currently deposited in DrugBank. Moreover, we identified disease areas and drug targets that are most prone to the negative effects of drug-food interactions, showcasing a platform for making recommendations in relation to foods that should be avoided under certain medications. Lastly, by investigating the correlation of gene expression signatures of foods and drugs we were able to generate a completely novel drug-diet interactome map.published_or_final_versio
Shearing Interferometer for Quantifying the Coherence of Hard X-Ray Beams
We report a quantitative measurement of the full transverse coherence function of the 14.4 keV x-ray radiation produced by an undulator at the Swiss Light Source. An x-ray grating interferometer consisting of a beam splitter phase grating and an analyzer amplitude grating has been used to measure the degree of coherence as a function of the beam separation out to 30 m. Importantly, the technique provides a model-free and spatially resolved measurement of the complex coherence function and is not restricted to high resolution detectors and small fields of view. The spatial characterization of the wave front has important applications in discovering localized defects in beam line optics
Analisis Produktivitas Tanaman Padi di Kabupaten Badung Provinsi Bali
The development of agricultural production in Badung Regency is more emphasized on increasing its productivity compared to the enhancement of the land area. Local governments in calculating rice production using the method known as tile. Results tile is very important because it is used as the official statistical data to calculate production, productivity, forecasting, etc.. Handling of production factors in the process of planting, fertilizer use, chemical product, pest management, and lack of knowledge about the tile farmers make rice productivity did not increase significantly. This research aims to assess development of rice plants productivity, to identify and determine factors affecting rice plants productivity in Badung, reviewing, analyzing the magnitude of gap between the estimated production produced by tile to rill production of selected farmers on rice fields.The method used is multiple linear regression and the average test pairs with 550 plots using secondary data and primary data sample tile by 41 respondents. Research results show that variables which have positive relation to the yied tile variable is the amount of clumps of rice, seed, and fertilizer. Whereas, the variable that have negative relation is the presence or absence of pesticides, plant pests attacks. The coefficient of determination the five independent variables in the tile result of rice is by 82.1%, and 17.9% explained by other variables. With the confidence level of 95% the five independent variables in the regression equation simultaneously can be used on explaining the outcome variable of rice tile. All the independent variables include (1) The number of clumps, (2) quantities of seed; (3) amount of fertilizer; (4) amount of pesticides, and (5) whether there is any plant pests attacks have a significant influence on yieldof rice tile. Based on primary data obtained from 41 samples of rice farmers, there is a difference between the estimated production produced by the rice tile to the real farmers results. The average the estimated value of the rice tile results is by 81.66 kg/acres while the real production output is by 69.10 kg/acres. The results of the estimation rice production is higher 18.18% compared to the real production.This estimate gives a higher estimate of the impact on local rice production and farmers income estimates excess of Rp 48,500 per are
An Evaluation of the Effects of Drought on Groundnut Yields in Kano
This study undertook an evaluation of the effects of drought on groundnut yields in Kano. The study was conducted using drought index, rainfall characteristics and groundnut yields. Twenty-nine years rainfall andgroundnut yields data were used for the study. The relationship between drought index and groundnut yields was determined via the use of correlation coefficient which reveals a significant correlation between both parameters. The study reveals that the nature and magnitude of the drought index affect the various yields of groundnuts in Kano especially among the years with episodic cases of drought in the study area. These findings have important implications on the crop yields of the study area. Drought frequency which constitutes decline in groundnut yields and other crops in general, would have serious socio-economic impact on Kano and Nigeria in general. Thus, it becomes necessary to put appropriate measures in place using the findings of this research to check the effects of drought index on groundnut yields among other crops in the study area
Validation of passive samplers for monitoring of acetic and formic acid in museum environments
Acetic acid and formic acid are volatile pollutants leading to degradation of some heritage materials. They are usually determined in museum environments with various types of passive samplers. In this work, SKC UMEx 200 passive samplers, originally intended for sampling of NO2 and SO2, have been validated for sampling of these organic acids. The sampling rates, extraction efficiency, loss through reverse diffusion or during storage, capacity, and detection limits were determined for both acids. For laboratory exposure, a known concentration of both acids was prepared in a flow-through reactor system at controlled temperature and humidity, the samplers were extracted, followed by analysis using ion chromatography. The sampling rates were determined to be 16.7 ml/min for acetic and 17.7 ml/min for formic acid and the detection limits for 7-day exposure were determined to be 2.1μg/m3 for acetic and 1.9μg/m3 for formic acid. The validated method was finally used for sampling of air in two case studies at the National Museum of Slovenia, where the concentrations in the range of 2–54μg/m3 were determined
Anomalous microwave conductivity coherence peak in c-axis MgB2 thin film
The temperature dependence of the real part of the microwave complex
conductivity at 17.9 GHz obtained from surface impedance measurements of two
c-axis oriented MgB2 thin films reveals a pronounced maximum at a temperature
around 0.6 times the critical temperature. Calculations in the frame of a
two-band model based on Bardeen-Cooper-Schrieffer (BCS) theory suggest that
this maximum corresponds to an anomalous coherence peak resembling the two-gap
nature of MgB2. Our model assumes there is no interband impurity scattering and
a weak interband pairing interaction, as suggested by bandstructure
calculations. In addition, the observation of a coherence peak indicates that
the pi-band is in the dirty limit and dominates the total conductivity of our
filmsComment: 10 pages, 4 figures, to be published in Phys. Rev. Let
Localisation humérale d’une tumeur à cellules géantes récidivantes (à propos d’un cas)
Les auteurs rapportent un cas de localisation rare d'une tumeur à cellules géantes au niveau de la palette humérale du coude droit chez unmilitaire de 36 ans de sexe masculin, la radio standard montrait une image kystique ne soufflant pas la corticale. L'examen anatomo-pathologiquea permis d' établir le diagnostic et le traitement a fait appel: au début a une Exérèse chirurgicale totale et une greffe osseuse par un greffon iliaquede la totalité de la palette huméral qui s'est compliquée à 6 mois de recule d une récidive locale
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