Shaping the Toroidal Section of End Mills

The shaping of the toroidal cutting section of end mills is considered. Methods are devised for selecting the positional parameters in shaping the helical rake surface on the toroidal section. Relations are established between the geometric parameters of the end mill in the toroidal section.     

Infectious disease mortality among adults by race and socioeconomic status: metropolitan Ohio, 1989-1991

The data presented here are part of an on-going longitudinal study of the relationship between socioeconomic status and mortality in the major metropolitan centers of Ohio. Using a Standardized Mortality Ratio, we find that mortality in the seven-city urban aggregate exceeds that of the rest of the state by 39 per cent for the nonwhite population and only 1 per cent for the white population. Further, for the nonwhite population, living in a high income area has no discernible health benefit for nonwhites as compared to whites. On the other hand, for the AIDS virus, there is a clear inverse association between economic status and mortality from AIDS. It is clear that the interrelationship among race, economic status, and health continues to be a complex one on which further research is needed.     

Analysis of performance of fuel elements of the BOR-60 reactor with vibrocompacted uranium-plutonium oxide fuel

Translated from Atomnaya Énergiya, Vol. 66, No. 5, pp. 299–302, May 1989.     

Reactive electric-discharge sintering of TiN-TiB2

Powder mixtures based on titanium and its dihydrides are sintered by electric discharge in a certain current mode to produce TiN + TiB₂ composites. It is established that the use of tetragonal titanium hydride as the starting material results in the complete synthesis leading to a TiN + TiB₂ composite. The higher shrinkage rate results from the higher purity of titanium dihydride, which, in its turn, increases the partial pressure of hydrogen in the reaction area and the reaction rate. Tetragonal titanium hydride is more preferable than cubic hydride and metal titanium. The microstructure of alloys resulting from the sintering of hydride-based mixtures is more homogenous: it includes equiaxial grains with the mean size of about 1 µm.     

"Even", integral indicators in systemic mathematical analysis of fatigue

The article considers 3 different points of view on systemic mathematical analysis of human fatigue process. In this case, the same physiologic information is processed according to various algorithms for integral and digital estimates of lowered performance and energy expenditure, as well as indirect characteristics of inhibition and excitation processes in the brain cortex. The mathematical results are applied in computer forecasting of individual occupational risk at the specific workplace.     

Dose proportionality and comparison of single and multiple dose pharmacokinetics of fexofenadine (MDL 16455) and its enantiomers in healthy male volunteers

The pharmacokinetics and dose proportionality of fexofenadine, a new non-sedating antihistamine, and its enantiomers were characterized after single and multiple-dose administration of its hydrochloride salt. A total of 24 healthy male volunteers (31 +/- 8 years) received oral doses of 20, 60, 120 and 240 mg fexofenadine HCl in a randomized, complete four-period cross-over design. Subjects received a single oral dose on day 1, and multiple oral doses every 12 h on day 3 through the morning on day 7. Treatments were separated by a 14-day washout period. Serial blood and urine samples were collected for up to 48 h following the first and last doses of fexofenadine HCl. Fexofenadine and its R(+) and S(-) enantiomers were analysed in plasma and urine by validated HPLC methods. Fexofenadine pharmacokinetics were linear across the 20-120 mg dose range, but a small disproportionate increase in area under the plasma concentration-time curve (AUC) (< 25%) was observed following the 240 mg dose. Single-dose pharmacokinetics of fexofenadine were predictive of steady-state pharmacokinetics. Urinary elimination of fexofenadine played a minor role (10%) in the disposition of this drug. A 63:37 steady-state ratio of R(+) and S(-) fexofenadine was observed in plasma. This ratio was essentially constant across time and dose. R(+) and S(-) fexofenadine were eliminated into urine in equal rates and quantities. All doses of fexofenadine HCl were well tolerated after single and multiple-dose administration.     

The effect of Val'kofen tablets for children on the function of the gastrointestinal tract and liver in an experiment

It was prepared new child's medicinal form, the tablets "Valcophene" for making a wider variety of pediatric preparation's. It is studied the influence of "Valcophene" on the functional state of alimentary canal in experiment on rat's. Results investigation's are testified to absence of ulcerative action in new child's preparations. Studying influence in liver functional state is provided for new children's preparation "Valcophene" too. The chronic experiment is showed that "Valcophene" didn't influence on liver in experimental animals.     

Numerical Shaping Method for Hobbing Tools

A numerical method is proposed for the shaping of tools used in machining complex surfaces with a periodical profile, including screw surfaces. A heuristic approach to Mathcad programming is adopted. The mathematical formulation includes a module generating spatial transformations of the coordinate systems in matrix form. On that basis, a numerical model of a hob profile is constructed. This approach permits single-stage shaping, without determining the profile of the associated helical gear.