The low-temperature surface diffusion of isolated Cr adatoms on Au(111) has been determined using nonperturbing x rays. Changes in the x-ray magnetic circular dichroism spectral line shape together with Monte Carlo calculations demonstrate that adatom nucleation proceeds via quantum tunneling diffusion rather than over-barrier hopping for temperatures <40K. The jump rates are shown to be as muc...

in this research work, alpha particle detector is made using semi-insulating gaas. a surface barrier detector with a semi-insulating gaas substrate at room temperature with pressure of 10-4 torr under -particle radiation with 5.48 mev of am241 source, have been under investigation. energy resolution of 2 and 3 mm schottky diameter have been matured and compared with the effect of voltage varia...

background: coordination is a critical factor in successful organization and appropriate response to disasters. in this regard, a centralized coordination mechanism is the first step towards an effective, efficient, and sustainable response in order to be ensured of the short- and long-term recovery. thus, this study aimed to identify and prioritize the barriers and facilitators of coordination...

Double-barrier GaAs/AlAs resonant tunneling diodes (RTDs) have become the promising elements for development of sub-mm and THz emitters. We report on fabrication RTD samples that were characterized via RF-reflectometry to determine parameters its equivalent circuit. By using numerical simulation we show coplanar transmission line with under study provides an amplification up 8 GHz. Keywords: Re...

Significance: The epidermal barrier prevents water loss and serves as the body's first line of defense against toxins, chemicals, and infectious microbes. Disruption of the barrier, either through congenital disorders of barrier formation or through wounds, puts the individual at risk for dehydration, hypersensitivity, infection, and prolonged inflammation. Epidermal barrier disorders affect mi...

A set of sensors establishes barrier coverage of a given line segment if every point of the segment is within the sensing range of a sensor. Given a line segment I, n mobile sensors in arbitrary initial positions on the line (not necessarily inside I) and the sensing ranges of the sensors, we are interested in finding final positions of sensors which establish a barrier coverage of I so that th...

this field study was conducted  to investigate barriers to applying principles of management in wards of tehran university on medical science hospitals: head nurses&apos; viewpoints .75 hednurses who  were working  in selected hospitals affiliated to tehran university of medical sciences. the data collection tool was a questionnaire that  it,s validity and reliability was obtained using content...

The interconnection of different tissue-tissue interfaces may extend organ-on-chips to a new generation of sophisticated models capable of recapitulating more complex organ-level functions. Single interfaces are largely recreated in organ-on-chips by culturing the cells on opposite sides of a porous membrane that splits a chamber in two or by connecting the cells of two adjacent compartments th...

Glomerular podocyte cells are critical for the function of the renal ultrafiltration barrier. Especially, the highly specialized cell-cell junction of podocytes, the slit diaphragm, has a central role in the filtration barrier. This is highlighted by the fact that mutations in molecular components of the slit diaphragm, including nephrin and Cd2-associated protein (Cd2ap), result in proteinuric...