In-situ synchrotron radiation photoemission spectroscopy study of the initial atomic layer deposition of Al2O3 film on Si(001) substrate.

In-situ synchrotron radiation photoemission spectroscopy and X-ray photoemission spectroscopy have been used to investigate the initial stages of Al2O3 growth on a Si(001) substrate by atomic layer deposition (ALD). The core level spectra of Si 2p, O 1s, and Al 2p as well as the valence band spectra were measured at every half reaction in the trimethylaluminum (TMA)-H2O ALD process. The line shape changes and binding energy shifts of the core level spectra reveal that Al2O3 is predominantly formed with a small amount of Si oxide in the initial stages without the formation of Al silicate. All core level spectra were alternately shifted toward higher and lower binding energies sides at every half ALD reaction. This can be explained by the band bending effect induced by different chemical species on the surface during the TMA-H2O ALD reaction. The valence band spectra showed that four cycles of ALD reactions were necessary to complete the electronic structure of the Al2O3 film with a valence band offset of 3.73 eV.

Treatment of non-biodegradable cutting oil wastewater by ultrasonication-Fenton oxidation process.

To treat cutting oil wastewater produced in metal surface treatment industry, Ultrasonication (US)-Fenton process, which is one of the advanced oxidation processes, was used. The optimum conditions to treat non-biodegradable pollutants using the US-Fenton process were that the application rates of H2O2 and FeSO4 were 10% and 3 g/L, respectively, the value of pH was 3, and the ultrasonication time was 30 min. It identified non-degradable pollutants such as ethylene diamine tetraacetic acid (EDTA) and Triethanolamine (TEA) in the cutting oil wastewater. TLC analysis of two compounds of treated water by the coagulation process was similar to that of raw water. However, TLC analysis of two compounds of US-Fenton process was different from that of raw water, meaning that US-Fenton process decomposed the EDTA and TEA. To study the possibility of application with the US-Fenton process to pilot plant, the pollutants treatment efficiency of three different methods, such as US-Fenton process, activated sludge process and coagulation process, in continuous experiments were compared. The removal rate of pollutants by the US-Fenton process according to the effluent time was higher than any other processes. The removal rates of COD, SS, T-N and T-P by US-Fenton process were 98, 93, 75 and 95%, respectively.

RBE of CF-252 neutrons by mouse testes weight loss.

Mouse testes weight decreased with increasing radiation dose following exposure to Cf-252 and its mixed neutron plus gamma radiation. The dose response for low dose rate (LDR) Cf-252 followed two components on an exponential plot of log percent weight loss vs. dose. Similar dose-response relationships were observed for acute 60Co or LDR Cs-137 radiations, but these required much larger doses to produce the same effect. The RBE was calculated against acute 60Co and Cs-137. There were no differences between acute 60Co and LDR Cs-137 effects. Cf-252 neutron RBE (n + gamma) was 3.7 for testes weight loss. RBEn for the neutrons-only was 5.1 RBE for the radiosensitive portion was 4.0.

RBE of spleen CFU-S to low dose rate Cf-252 or photon radiation in vivo.

The biological effects of low dose rate (LDR) Cf-252 radiation were compared to LDR Cs-137 photon radiation and acute 60Co radiation. The RBEn for endogenous CFU-S in vivo was 2.1 for neutron radiation at a dose rate of 9.9 cGy/hr of Cf-252 radiation. The value was consistent with previous in vitro experiments where a value of 2.1 was found. For the low doses and low dose rates studied, we tested an acute assay dose following the LDR irradiation to determine dose-effect and RBEn. Organ size shrinkage and regeneration patterns after LDR Cf-252 and Cs-137 were also studied and showed greater growth delay for Cf-252 irradiated lympho-hemopoietic tissues.

Nasopharyngeal carcinoma in the people's Republic of China: incidence, treatment, and survival rates.

The incidence, treatment regimens, and survival rates for nasopharyngeal carcinoma in China, one of the most common cancers in that country, are reviewed. Although treated almost exclusively with megavoltage photon therapy, in some cancer centers intracavitary radium insertions are used to increase the radiation dose to the primary tumor site. A histological study of these tumors shows that patients whose tumors are well-differentiated and contain an abundance of lymphocytes have the best prognosis.

RBE of spleen CFU-S to low dose rate Cf-252 neutron or photon radiation.

The RBE of Cf-252 neutron irradiation was determined for hemopoietic tissue using spleen CFU-S. Radiosensitivity was compared to acute Cobalt-60 radiation and low dose rate Cesium-137 under identical irradiation conditions. The RBE for the neutron component of the Cf-252 radiation was 2.1. No dose rate effect was observed for hemopoietic CFU-S to acute doses or low dose rate photon irradiation.