Hydrocode simulations of lunar impact events show that craters as small as 450 meters in diameter are viable candidates for the source of most lunar meteorites. The lunar cratering flux implies that 6 impact events of this size occurred on the moon in the last 0.1 Ma. This is in good agreement with the number of impacts (7) inferred from the geochemical analysis of the samples in hand. The resu...

In the case of gravitationally-lensed quasars, it is well-known that there is a time delay between occurrence of the intrinsic variabilities in each split image. Generally, the source of variabilities has a finite size, and there are time delays even in one image. If the origin of variabilities is widely distributed, say over > ∼ 100 pc as whole, variabilities between split images will not show...

Small populations are predicted to perform poorly relative to large populations when experiencing environmental change. To explore this prediction in nature, data from reciprocal transplant, common garden, and translocation studies were compared meta-analytically. We contrasted changes in performance resulting from transplantation to new environments among individuals originating from different...

This study details a method to evaluate the source size selection for small field intracranial stereotactic radiosurgery (SRS) deliveries in Eclipse treatment planning system (TPS) for AcurosXB dose calculation algorithm. Our method uses end-to-end dosimetric data to evaluate a total of five source size selections (0.50 mm, 0.75 mm, 1.00 mm, 1.25 mm, and 1.50 mm). The dosimetric leaf gap (DLG) ...

We have measured electron and positron beam source size at CHESS when the Cornell Electron Storage Ring (CESR) is run dedicated for the production of synchrotron radiation. Horizontal source size at several beamlines is expected to shrink by a factor of two but synchrotron (visible) light measurements only provide the vertical size. Therefore a “crystal collimator” using two Bragg reflection in...

A fundamental unit of work in programming is the code contribution (“commit”) that a developer makes to the code base of the project in work. We use statistical methods to derive a model of the probabilistic distribution of commit sizes in open source projects and we show that the model is applicable to different project sizes. We use both graphical as well as statistical methods to validate th...

in this scientific research zns nanoparticle was synthesized via precipitation method. two samples were synthesized by this method. the nanoparticle was characterized by xrd techniques, and the size and kind of crystallinity were identified by x-ray diffraction pattern as well. the size measurement has been done by using scherrer's equation. the average sizes of nanoparticles in two sample...

zno and zno:mn nanocrystals synthesized via reverse micelle method. the size, band gap, urbach energy, optical constants and penetration depth of nanocrystals were calculated by uv-vis spectroscopy data. the surface morphology was studied with the use of scanning electron microscope (sem). moreover the samples exposed to gama ray source of 60co and their thermoluminescence properties were also ...

single-walled carbon nanotubes (swnts) with high yield and quality were synthesized using chemical vapor deposition (cvd) over co-mo/ mgo nanocatalyst in a fluidized bed reactor. different parameters such as temperature, the ratio of hydrocarbon source to hydrogen, the flow rate of gas, growth time, the size of catalyst particles, heating rate, and the kind of hydrocarbon source were examined t...