Effects on the mechanical strength of poly-L-lactic acid (PLLA) upon irradiation with 150 keV He(+) ion were studied. Changes in the irradiated surface were investigated using a surface texture and contour measuring instrument and an atomic force microscope. Observations made with the atomic force microscope revealed that the irradiated surface subsided significantly as the fluence increased. I...

Fluence response relationships for the induction of DNA damage in the skin of I \ -irradiali-«!Xiphophorus fish were obtained by quantitative gel electrophoresis of unlabeled DNA following extraction and treatment with an enzyme preparation that makes single strand breaks next to cyclobutane pyrimidine dimers. A buffer containing 7 M urea minimized the degradation of DNA during extraction and ...

The problem of determining the in vivo dosimetry for patients undergoing radiation treatment has been an area of interest since the development of the field. More recent methods of measurement employ Electronic Portal Image Devices (EPID), or dosimeter arrays, for entrance or exit fluence determination. The more recent methods of in vivo dosimetry make use of detector arrays and reconstruction ...

A total of 125 large fluence solar proton events identified from the nitrate deposition in ice core from Greenland for the period 1561-1950 are examined in an exploratory study of the geophysical information that will be available from such data in the future. These data have been augmented with ionospheric and satellite data for the period 1950-1994. There were five periods in the vicinity of ...

This study examined the effectiveness of an open channel, low pressure (LP), ultraviolet (UV) reactor for water treatment in a low head (LH) recirculating aquaculture system (RAS). Currently available UV reactors use high pressure pumps and submerged bulbs. The reactor in this study makes use of the head gained by the water recirculation of the LH-RAS without the need for additional pumps, whil...

Photodynamic therapy (PDT) regimens that conserve tumor oxygenation are typically more efficacious, but require longer treatment times. This makes them clinically unfavorable. In this report, the inverse pairing of fluence rate and photosensitizer dose is investigated as a means of controlling oxygen depletion and benefiting therapeutic response to PDT under conditions of constant treatment tim...

AlGaN/GaN high electron mobility transistors (HEMTs) were exposed to 3 MeV protons at fluences of 6 10, 4 10 and 1 10 protons/cm. The drain saturation currents decreased by 20% and the maximum transconductance decreased by 5% at the highest fluence. As the fluence increased, the threshold voltage shifted more positive values. After proton irradiation, the gate leakage current increased. The Sch...

The advantage of using lasers for through silicon via (TSV) drilling is that they allow higher flexibility during manufacturing because vacuums, lithography, and masks are not required; furthermore, lasers can be applied to metal and dielectric layers other than silicon. However, conventional nanosecond lasers have disadvantages including that they can cause heat affection around the target are...

A method to convert integrated electronic portal imaging device (EPID) images to fluence for the purpose of reconstructing the dose to a phantom is investigated here for simple open fields. Ultimately, the goal is to develop a method to reconstruct the dose to patients. The EPID images are transformed into incident intensity fluence by spatial filtering with a deconvolution kernel. The kernel u...

We studied the effects of 100 keV proton irradiation on films of ammonia-water mixtures between 20 and 120 K. Irradiation destroys ammonia, leading to the formation and trapping of H(2), N(2), NO, and N(2)O, the formation of cavities containing radiolytic gases, and ejection of molecules by sputtering. Using infrared spectroscopy, we show that at all temperatures the destruction of ammonia is s...