Corrosion of Heating Surfaces of Power Station Boiler Equipment Made of Steel 12X18H10T

The long-term operation of thermal power equipment made of 12X18H10T steel at a temperature of 550°C and higher changes its performance due to the changed composition of inside surfaces and bodies of tubes. To avoid deterioration of service characteristics during the operation, the thermal equipment is recommended to make of low-carbon chrome-nickel stainless steels or niobium-stabilized steels. Preservation of the equipment by octadecylamine should be carried out only at a working temperature below its thermodestruction temperature.     

Investigations of Ultrasound Propagation in Porous Impurity-Helium Solids

The velocity and attenuation of ultrasound passing through porous impurity-helium solids immersed in liquid ⁴He have been measured in the temperature range 1.1–2.3 K. These solids were formed by injecting a mixture of impurity (e.g. D₂, Ne, N₂ or Kr) and helium gases into superfluid ⁴He. The sound signal seemed to propagate mainly in the helium contained in the pores, rather than through the solid sample itself. We found that the speed of sound at low temperatures is close to and decreases more rapidly with temperature than first sound in bulk helium, similar to behavior observed in aerogel. The attenuation of sound in helium in the compressed impurity-helium solids is bigger than in bulk helium and increases rapidly with temperature up to 1.65 K, after which a crossover to a much weaker temperature dependence was observed.     

Correction of ozone influence on TOA radiance

An accurate atmospheric correction (AC) of Earth remote-sensing data in the spectral region 450–800 nm has to account for the ozone gas absorption influence. Usual operational AC codes employ a fixed ozone concentration corresponding to a climatologic average for a certain region and season, e.g. the mid-latitude summer atmosphere of the Moderate Resolution Atmospheric Transmission (MODTRAN) code. The reasons for a fixed ozone column are that ozone does not vary rapidly on a spatial and temporal scale, and additionally, the look-up table (LUT) size for AC is already big. This means that another degree of freedom for the ozone parameter would dramatically increase the size of the LUT database and the time required for LUT interpolation. In order to account for this effect, we use already existing LUTs that were calculated for a certain ozone reference level, e.g. an ozone column of g = 330 Dobson Units (DU) for MODTRAN’s mid-latitude summer atmosphere. Then the deviation of the top-of-atmosphere (TOA) radiance ΔL(g) from the reference level L(g = 330) is calculated as a function of solar and view geometries. The calculation is performed for a set of 36 wavelengths in the ozone-sensitive spectrum (450–800 nm) and five ozone columns. The last step computes the linear regression coefficients for each wavelength and geometry. The results are stored in a small table (11 kB). It is shown that the ozone influence is accurately accounted for by multiplying the modelled radiance L(g = 330) with a factor depending on g and wavelength yielding TOA radiance relative errors smaller than 0.5% for a wide range of ozone concentrations between 180 and 500 DU. Selected examples of a sensitivity study of the ozone effect on the retrieval of water constituents demonstrate the need to account for ozone in the AC step.     

Effect of an explosion on the grindability of ferruginous quartzites as a function of layering orientation and distance to the charge

Research Institute of Kursk Magnetic Anomaly and Polytechnical Institute, Lebedin Mining and Concentration Plant, Gubkin. Mining Institute, Moscow. Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 5, pp. 67-71, September-October, 1991.     

Thermodynamic Properties of Methanol in the Critical and Supercritical Regions

The isochoric heat capacity of pure methanol in the temperature range from 482 to 533 K, at near-critical densities between 274.87 and 331.59 kg· m⁻³, has been measured by using a high-temperature and high-pressure nearly constant volume adiabatic calorimeter. The measurements were performed in the single- and two-phase regions including along the coexistence curve. Uncertainties of the isochoric heat capacity measurements are estimated to be within 2%. The single- and two-phase isochoric heat capacities, temperatures, and densities at saturation were extracted from experimental data for each measured isochore. The critical temperature (T_c = 512.78±0.02K) and the critical density (ρ_c = 277.49±2 kg · m⁻³) for pure methanol were derived from the isochoric heat-capacity measurements by using the well-established method of quasi-static thermograms. The results of the C_VVT measurements together with recent new experimental PVT data for pure methanol were used to develop a thermodynamically self-consistent Helmholtz free-energy parametric crossover model, CREOS97-04. The accuracy of the crossover model was confirmed by a comprehensive comparison with available experimental data for pure methanol and values calculated with various multiparameter equations of state and correlations. In the critical and supercritical regions at 0.98T_c≤ T ≤ 1.5T_c and in the density range 0.35ρ_c ≤ ρ leq 1.65 ρ_c, CREOS97-04 represents all available experimental thermodynamic data for pure methanol to within their experimental uncertainties.     

Familial adenomatous polyposis

Familial adenomatous polyposis (FAP) is an autosomal dominant disease characterized by the development of numerous adenomatous polyps in the colon and rectum with diverse extracolonic manifestations. Recent genetic advances have lead to the sequencing of the FAP gene, with important implications for screening, diagnosis and follow-up. Appropriate management of probands and at-risk patients is of the utmost importance, as untreated carriers will develop colorectal cancer. Identification of FAP families and tracing of pedigrees represent the most important steps. To this end registries are essential, allowing a comprehensive multidisciplinary approach. They have justified their place by decreasing related morbidity and mortality. An overview and discussion of clinical features and management are presented.     

Making99Mo in reactors

Conclusions This comparison of two ways of making⁹⁹Mo shows that there is good scope for making it in any area. If there is a thermal reactor having a high flux, one can make⁹⁹Mo from⁹⁸Mo, and in that case, even irradiation in a high flux makes it favorable to use highly enriched⁹⁸Mo and unblocked targets, which raises the specific activity and thus increases the working life in the^99mTc generator.If there is a thermal reactor with low flux or if there is a fast reactor it is best to make⁹⁹Mo from uranium fission products. The target can be highly enriched²³⁵U, which if necessary can be reused, or low-enriched uranium.There are no essential constraints on making⁹⁹Mo, and the production is mainly based on technological tasks.Translated from Atomnaya Énergiya, Vol. 67, No. 2, pp. 104–108, August, 1989.     

Co-morbidities and survival of men with localized prostate cancer treated with surgery or radiation therapy

PURPOSE: We determined the impact of preexisting co-morbidities on survival of men with clinical stages T1b and T2NXM0 prostate cancer treated with surgery or radiation therapy. MATERIALS AND METHODS: A weighted co-morbidity score was determined for 276 consecutive men treated with surgery (138) or radiation therapy (138) at a Veterans Affairs medical center and was correlated with actuarial freedom from death due to co-morbid disease. RESULTS: After a median potential followup of 7.0 years 91 patients (33%) died of co-morbid disease and 20 (7%) died of cancer related causes. There were highly significant correlations between actuarial survival and weighted co-morbidity (p < 0.000001), and the 10-year actuarial survivals in men with no or severe co-morbidities were 66 and 9%, respectively. Associations between patient age and co-morbidity score were highly significant (p < 0.0001). The age adjusted risk of co-morbid death was 5.7 times greater in men with severe compared to no co-morbidities. There were also significant correlations between actuarial survival and weighted co-morbidity among patients treated with surgery (p = 0.02) and radiation therapy (p = 0.0002). Patient age and severity of co-morbidities were significantly greater among men treated with radiation therapy compared to surgery, and age adjusted risk of co-morbid death among men with a co-morbidity score of 1 was 3.8 times greater among men treated with radiation therapy (p = 0.025). CONCLUSIONS: Cancer related deaths are unusual within 5 to 10 years after surgery or radiation therapy in men with stages T1b and 2 prostate cancer. The risk of death during this interval is directly related to the severity of co-morbid conditions, which should be factored in an individual when assessing the advisability of therapeutic intervention. Since patient co-morbidities impact all cause survival, quantitative assessment of co-morbidities using validated instruments offers a method to control partially for the variabilities of health status among men receiving different treatments for localized prostate cancer.     

Isochoric Heat Capacity of Heavy Water at Subcritical and Supercritical Conditions

The heat capacity of heavy water was measured in the temperature range from 294 to 746 K and at densities between 52 and 1105 kg·m^–3 using a high-temperature, high-pressure adiabatic calorimeter. The measurements were performed at 14 liquid and 9 vapor densities between 52 and 1105 kg·m^–3. Uncertainties of the measurements are estimated to be within 3% for vapor isochores and 1.5% for the liquid isochores. In the region of the immediate vicinity of the critical point (0.97T/T _c1.03 and 0.75/_c1.25), the uncertainty is 4.5%. The original C _V data were corrected and converted to the new ITS-90 temperature scale. A parametric crossover equation of state was used to represent the isochoric heat capacity measurements of heavy water in the extended critical region, 0.8T/T _c1.5 and 0.35/_c1.65. The liquid and vapor one- and two-phase isochoric heat capacities, temperatures, and saturation densities were extracted from experimental data for each measured isochore. Most of the experimental data are compared with the Hill equation of state, and the overall statistics of deviations between experimental data and the equation of state are given.