In this research graphene oxide was synthesized by two methods. These methods were achieved by changing the improved Hummers’ and modified Hummers’ methods. Structure of graphene oxide was characterized by scanning electron microscopy (SEM) images, X-ray diffraction (XRD) patterns, Raman spectroscopy and Fourier transform infrared (FTIR) spectra. According to SEM image, the thickness of graphen...

background: several landmine detection methods, based on nuclear techniques, have been suggested up to now. neutron-induced gamma emission, neutron and gamma attenuation, and fast neutron backscattering are the nuclear methods used for landmine detection. in this paper an optimized (safe and effective) moderating structure using an 241am-be neutron source for detecting landmines has been invest...

in this research graphene oxide was synthesized by two methods. these methods were achieved by changing the improved hummers’ and modified hummers’ methods. structure of graphene oxide was characterized by scanning electron microscopy (sem) images, x-ray diffraction (xrd) patterns, raman spectroscopy and fourier transform infrared (ftir) spectra. according to sem image, the thickness of graphen...

ZnO nanowires were grown in gram quantities on graphite flakes (as collector) using the vapour transport and condensation approach. The yield, defined as the weight ratio of ZnO nanowires to the original graphite flakes, has been studied thoroughly by tuning the various growth parameters such as pressure and temperature inside the tube furnace, the amount of graphite powder in the original sour...

The National Ocean Sciences Accelerator Mass Spectrometry (NOSAMS) facility at the Woods Hole Oceanographic Institution has developed an Accelerator Mass Spectrometry (AMS) system designed specifically for the analysis of C in a continuously flowing stream of carrier gas. A key part of the system is a gas-accepting microwave ion source. Recently, substantial progress has been made in the develo...

Abundant graphite particles occur in amphibolite-grade quartzite of the Archean-Paleoproterozoic Wutai Metamorphic Complex in the Wutaishan area of North China. Petrographic thin section observations suggest that the graphite particles occur within and between quartzite clasts and are heterogeneous in origin. Using HF maceration techniques, the Wutai graphite particles were extracted for furthe...

Pseudomorphic Si12yCy alloys on silicon ~100! were grown by molecular beam epitaxy using a single effusion source of silicon contained in a graphite crucible, producing carbon concentrations of y50.008. The behavior of carbon incorporation using this source was studied as a function of growth temperature using x-ray diffraction and infrared spectroscopy, and was compared to previous studies, wh...

Cubic diamond was synthesized with two systems, (1) graphite with pure magnesium carbonate (magnesite) and (2) graphite with mixed potassium and magnesium carbonate at pressures and temperatures above 9.5 GPa, 1600 ±C and 9 GPa, 1650 ±C, respectively. At these conditions (1) the pure magnesite is solid, whereas (2) the mixed carbonate exists as a melt. In this pressure range, graphite seems to ...

A high -temperature blackbody radiation source, consisting of an electrically heated graphite tube with a small centrally located hole through one wall, was developed for use as a secondary standard in the calibration of radiometric and spectrometrlc instruments. The spectral emlssivity of this source, at 0.65 M» was calculated by the DeVos method, for which graphite emissivities and temperatur...

Absorbed dose to water in a cobalt-60 gamma-ray beam has been determined using a thick-walled graphite ionization chamber. The chamber was calibrated in a graphite phantom against a graphite calorimeter, and the graphite calibration factor was converted to a water calibration factor using published energy absorption coefficient ratios and a measured replacement factor. Comparisons between the g...