Communication research between working capacity of hardalloy cutting tools and fractal dimension of their wear

The results of communication research between the wear resistance of the Kapplicability hard-alloy cutting tools and the fractal dimension of the wear surface,which is formed on a back side of the cutting edge when processing the materialsshowing high adhesive activity are presented in the paper. It has been established thatthe wear resistance of tested cutting tools samples increases according to a fractaldimension increase of their wear surface

Dependence of the diffusion wear of the hard alloy surface on its fractal dimension

The paper presents the research results in the synergies between the wear resistance of carbide cutting tools of P-group applicability and fractal dimension of the wear surface occurring on the rake face of the tool when processing the material, which causes intensive diffusion wear. It was found that the resistance of carbide cutting tools increases as the fractal dimension of their wear surface reduces

Selection of patients with severe pelvic fracture for early angiography remains controversial

<p>Abstract</p> <p>Background</p> <p>Patients with severe pelvic fractures represent about 3% of all skeletal fractures. Hemodynamic compromise in unstable pelvic fractures is associated with arterial hemorrhage in less than 20% of patients. Angiography is an important tool in the management of severe pelvic injury, but indications and timing for its performance remain controversial.</p> <p>Methods</p> <p>Patients with major pelvic fractures [Pelvic Abbreviated Injury Score (AIS) ≥ 3] admitted to two high volume Trauma Centers from January 2000 to June 2005 were identified and divided into two groups: Group I patients did not undergo angiography, Group II patients underwent angiography with/without embolization. Demographics, hemodynamic status on admission, concomitant injuries, Glasgow Coma Scale (GCS), Injury Severity Score (ISS), pelvic AIS, blood requirement before and after angiography, arterial blood gases and mortality were evaluated. Patients with an additional reason for hemodynamic instability were excluded.</p> <p>Results</p> <p>Charts of 106 patients were retrospectively reviewed. Twenty nine patients (27.4%) underwent angiography. Bleeding vessel embolization was performed in 20 (18.9%) patients. Patients who underwent angiography had a significantly higher pelvic AIS and a lower Base Excess level on admission. A blood transfusion rate of greater than 0.5 unit/hour was found to be a reliable indicator for early angiography.</p> <p>Conclusion</p> <p>A high pelvic AIS, amount of blood transfusions and decreased BE level should be considered as an indicators for early angiography in patients with severe pelvic injury.</p

On the issue of charging traction batteries for mainline road transport

The preservation of the environment is a very urgent task today. In this regard, work is underway in many countries of the world on the design and production of electric vehicles. However, the operation of such vehicles is inextricably linked with the creation of an infrastructure for charging traction batteries. In urban conditions, the construction of infrastructure does not require the creation of special conditions. To ensure long-distance transportation, the use of electric vehicles is hampered by the lack of supply of electric power, and, consequently, the infrastructure for charging traction batteries. The solution to this problem may be the installation of an electric power generation unit on a vehicle directly during movement. This installation must ensure the necessary level of environmental friendliness during operation. These installations can run on hydrogen or natural gas. In this paper, the possibility of using a hydrogen fuel cell power plant to recharge traction batteries in transport is considered

Electromagnetic shape resonances of a dielectric sphere and radiation of portable telephones

The frequency band used by cellular telephones includes the eigenfrequencies of a dielectric sphere with physical characteristics close to those of a human head. Proceeding from the spatial features of the natural modes of such a sphere we propose an independent and clear evident accuracy test for the complicated numerical calculations which are conducted when estimating the potential hazard due to the use of cellular telephones, in particular, for the check of a proper handling of the electromagnetic shape resonances of a human head.Comment: 10 pages, 1 figure with 2 eps file

Numerical Solution of the Time Dependent 3D Schrödinger Equation Describing Tunneling of Atoms from Anharmonic Traps

We present an efficient numerical method for the integration of the 3D Schrödinger equation. A tunneling problem of two interacting bosonic atoms confined in a 1D anharmonic trap has been successfully solved by means of this method. We demonstrate fast convergence of the final results with respect to spatial and temporal grid steps. The computational scheme is based on the operator-splitting technique with the implicit Crank-Nicolson algorithm on spatial sixth-order finite-differences. The computational time is proportional to the number of spatial grid points

Розробка методу оцінювання рівня екологічної безпеки житлового приміщення та його апробація

The method of estimating the level of ecological safety of a housing accommodation by environmental factors: physical, chemical, microclimatic and aesthetic is presented. Groups of danger factors in the structure of such a category of life quality as “Environmental safety of a dwelling house” are formed.The analysis of modern scientific studies showed that the vast majority of researchers use the survey method when assessing the quality of dwellings. This approach is justified in terms of the ease of processing the results. However, when using this approach, it is difficult to avoid subjectivity in assessment.Qualimetric tables have been compiled for the scoring assessment of the selected environmental hazards factors. Based on the values of the hazard factors scoring assessment and their weight determination, a formula is proposed for determining the numerical value of the integral indicator of the environmental safety of the dwelling.The application of the developed method allows:– assessing the existing environmental safety level of residential premises to manage its quality, in terms of both new construction and reconstruction;– justifying the choice of new architectural projects regarding environmental safety in the room;– estimating the cost of a premise when it is purchased on the primary or secondary market in the conditions of equivalence of all other parameters such as location, the state of the infrastructure of the district, etc.Представлен метод оценки уровня экологической безопасности жилого помещения. Метод отличается от известных узкой направленностью именно на оценку качества жилой среды по экологическим факторам: физическим, химическим, микроклиматическим и эстетическим, а также позволяет принимать управленческие решения на основе результатов оценки. При этом фактическое влияние факторов экологической опасности сравнивается с действующими нормативами качества жилой среды. Метод апробирован для условий реальной жилой застройки в г. Днепр, (Украина)Представлено метод оцінювання рівня екологічної безпеки житлового приміщення. Метод відрізняється від відомих вузькою спрямованістю саме на оцінку якості житлового середовища за екологічними чинниками, серед яких: фізичні, хімічні, мікрокліматичні та естетичні, а також дозволяє приймати управлінські рішення на основі результатів оцінки. При цьому фактичний вплив факторів екологічної небезпеки порівнюється з діючими нормативами якості житлового середовища. Метод апробовано для умов реальної житлової забудови у м. Дніпро, Україн

The relation between the inductive capacity of an oxide surface structure of hard alloys and their wear resistance

The purpose of this research is to determine the value of specific inductive capacity of oxide structures formed on the contact surfaces of carbide cutting tools. This paper also deals with the study of the effect of specific inductive capacity of polyoxide structures on the wear resistance of cutting tools exposed to intensive adhesive wear. It was established that the decrease of specific inductive capacity of the oxide film mass formed on the contact surfaces of a wedge leads to the increase of the wear resistance of cutting tools