the need for clean groundwater resources to have sustainable development in a country is undoubted. due to the importance and high quality of karstic waters in supplying water in iran especially in shahrood city, it is attempted in this research work to recognize and explore karstic waters in southwest of tepal area, shahrood. for this purpose, integration of the results obtained from the metho...

gamma camera is an important apparatus in nuclear medicine imaging. its detection part is consists of a scintillation detector with aheavy collimator. substitution of semiconductor detectors instead of scintillator in these cameras has been effectively studied. in this study, it is aimed to introduce a new design of p-n semiconductor detector array for nuclear medicine imaging. a p-n semiconduc...

Laminar free convection heat transfer from vertical and inclined arrays of horizontal isothermal cylinders in air was investigated experimentally and numerically. Experiments were carried out using Mach-Zehnder interferometer and the FLUENT code was used for numerical study. Investigation was performed for vertical and horizontal cylinder spacing from 2 to 5 and 0 to 2 cylinder diameters respec...

A near sea floor, 200 meter vertical acoustic array is being developed as part of a long term sea floor monitoring station to study gas hydrate deposits. This report addresses progress in the development of a vertical seismic array system specifically designed for 3-dimensional mapping of shallow gas hydrate deposits. The time frame covered in this report includes the first half of the second y...

Experimental data are presented for large arrays of rotating, variable-height cylinders in order to study the dependence of the three-dimensional mean flows on the height heterogeneity of the array. Elements in the examined arrays were spatially arranged in the same staggered paired configuration, and the heights of each element pair varied up to 637.5% from the mean height (kept constant acros...

This paper presents the performance of three methods for estimating the range of broadband (50-500 Hz) bowhead whale calls in a nominally 55-m-deep waveguide: Conventional mode filtering (CMF), synthetic time reversal (STR), and triangulation. The first two methods use a linear vertical array to exploit dispersive propagation effects in the underwater sound channel. The triangulation technique ...

ZnO nanorods array films were coated on a glass template through a two-step chemical process. First, a sol-gel spin coating method was used to produce a ZnO seed layer and after that, the ZnO nanorods arrays were grown on it through a low temperature aqueous method. Synthesized films were studied by scanning electron microscope (SEM) and X-ray diffractometer (XRD). X-ray diffraction results sho...