The stress corrosion cracking (SCC) of structural materials used in boiling water reactors has been studied at relatively low hydrogen peroxide (H202) concentrations, around 10 ppb, which was assumed to be representative of the corrosion environment formed in hydrogen water chemistry (HWC). The 1/4T compact tension specimen was used for measurement of crack growth rates (CGRs) of sensitized type 304 stainless steel in high temperature and high purity water. Crack length was monitored by a reversing direct current potential drop method. Since H202 is easily decomposed thermally, a polytetrafluoroethylene-lined autoclave was used to minimize its decomposition on the autoclave surface. The CGR in the H20 2 environment differed from that in the 02 environment even though the electrochemical corrosion potential (ECP) for both conditions was the same. The data implied that the ECP could not be used as a common environmental deterministic parameter for SCC behavior at higher potentials for different oxidant conditions. The corrosion current density was found to play an important role as an environmental index for SCC, which was given as just the current density at the ECP at a specific oxidant concentration. The CGRs were found to be written as CGR = (3.8±0.6) X 10-3 icor+(l.5±1.6) X 10-s mm/s using the calculated corrosion current density icor below 10-4 A-cm-2 .

A novel approach to the analysis of ecstasy tablets by direct mass spectrometry coupled with thermal desorption (TD) and counter-flow introduction atmospheric pressure chemical ionization (CFI-APCI) is described. Analytes were thermally desorbed with a metal block heater and introduced to a CFI-APCI source with ambient air by a diaphragm pump. Water in the air was sufficient to act as the reactive reagent responsible for the generation of ions in the positive corona discharge. TD-CFI-APCI required neither a nebulizing gas nor solvent flow and the accompanying laborious optimizations. Ions generated were sent in the direction opposite to the air flow by an electric field and introduced into an ion trap mass spectrometer. The major ions corresponding to the protonated molecules ([M + H](+)) were observed with several fragment ions in full scan mass spectrometry (MS) mode. Collision-induced dissociation of protonated molecules gave characteristic product-ion mass spectra and provided identification of the analytes within 5 s. The method required neither sample pretreatment nor a chromatographic separation step. The effectiveness of the combination of TD and CFI-APCI was demonstrated by application to the direct mass spectrometric analysis of ecstasy tablets and legal pharmaceutical products.

In order to determine. the effects of hydrogen peroxide on electrochemical corrosion potential (ECP) of type 304 stainless steel (SUS304), ECPs were measured using a high temperature, high pressure water loop with polytetrafluoroethylene (PTFE) inner liner at controlled hydrogen peroxide concentration. It is observed that the ECP of SUS304 exposed to hydrogen peroxide is higher than that when exposed to oxygen at the same oxidant concentration. The ECP shows a hysteresis pattern for its concentration dependency. Those results were attributed mainly from the chemical form of oxide film on stainless steel specimens. The oxide film was affected by the corrosive circumstances. Hematite (a-Fe203) was observed for the specimens exposed to hydrogen peroxide, while Fe304 was a main oxide when exposed to oxygen. The difference of the anodic polarization curves between 02 and H202 environments was caused by the difference of the stability between a-Fe203 and Fe304. Since the a-Fe20 3 is reduced to the Fe 2 + when hydrogen is added to water, the ECP decreases with decreasing oxidant concentration without showing the hysteresis that keep the ECP higher value.

The flux and velocity of Cu and Ti vaporized by an electron beam were measured by a microbalance. A small disk was hung horizontally above the crucible and its weight change was measured by the microbalance. The flux was determined from the weight change due to vaporized atom deposition under the disk base. The total momentum of deposited atoms per unit time was determined from the weight change before and after the vapor was turned off by a shutter. The velocity could then be calculated from these two values. The velocity obtained for Cu depended slightly on the vaporization temperature and had reasonable agreement with the theoretical estimation obtained using an ideal gas treatment. The velocity of Ti was slightly higher than the theoretical result. Since Ti was excited to several metastable energy levels by electron beam heating, such an internal energy should be converted to kinetic energy following adiabatic expansion and would account for the velocity increase. The internal energy by excitation to the metastable energy levels must be taken into consideration in the case of high temperature heating, as with an electron beam evaporative source.

In order to determine. the effects of hydrogen peroxide on electrochemical corrosion potential (ECP) of type 304 stainless steel (SUS304), ECPs were measured using a high temperature, high pressure water loop with polytetrafluoroethylene (PTFE) inner liner at controlled hydrogen peroxide concentration. It is observed that the ECP of SUS304 exposed to hydrogen peroxide is higher than that when exposed to oxygen at the same oxidant concentration. The ECP shows a hysteresis pattern for its concentration dependency. Those results were attributed mainly from the chemical form of oxide film on stainless steel specimens. The oxide film was affected by the corrosive circumstances. Hematite (a-Fe203) was observed for the specimens exposed to hydrogen peroxide, while Fe304 was a main oxide when exposed to oxygen. The difference of the anodic polarization curves between 02 and H202 environments was caused by the difference of the stability between a-Fe203 and Fe304. Since the a-Fe20 3 is reduced to the Fe 2 + when hydrogen is added to water, the ECP decreases with decreasing oxidant concentration without showing the hysteresis that keep the ECP higher value.