Grinding Head

FIELD: mechanical engineering. SUBSTANCE: grinding head is offered, designed for re-grinding the thrust centers of roller grinding machines. The head includes a rotary grinding mechanism with an electric spindle, rotating a conical grinding wheel. The axis of rotation of the rotary grinding mechanism coincides with the regrinded center axis. The rotation of the electric spindle provides the main movement of the processing, the rotation of the rotary grinding mechanism provides the circumferential feed. The head is equipped with two mirror-positioned rotary grinding mechanisms and an electric motor that alternately rotates both mechanisms. The inclusion of a particular mechanism in operation occurs with the help of electromagnetic clutches and switching of clutches and control elements of electric spindles using a two-pole flip switch. EFFECT: increased reliability of the grinding head, which makes it possible to regrind the front and rear centers of the roller grinding machine without resetting it, which increases the processing accuracy. The increase in accuracy is expressed in a more accurate provision of the coaxiality of the centers. 1 cl, 1 dwg.Предлагается шлифовальная головка, предназначенная для перешлифовки упорных центров вальцешлифовальных станков. Головка включает в себя поворотный шлифовальный механизм с электрошпинделем, вращающий конический шлифовальный круг. Ось вращения поворотного шлифовального механизма совпадает с осью перешлифовываемого центра. Вращение электрошпинделя обеспечивает главное движение обработки, вращение поворотного шлифовального механизма - окружную подачу. Головка снабжена двумя зеркально расположенными поворотными шлифовальными механизмами и электродвигателем, попеременно вращающим оба механизма. Включение того или иного механизма в работу происходит с помощью электромагнитных муфт и переключения муфт и элементов управления электрошпинделями с помощью двухполюсного перекидного переключателя. Технический результат заключается в повышении надежности шлифовальной головки, которая позволяет без её переустановки перешлифовать передний и задний центры вальцешлифовального станка, что повышает точность обработки. Повышение точности, выражается в более точном обеспечении соосности центров. 1 ил

Ear, nose and throat injuries at Bugando Medical Centre in northwestern Tanzania: a five-year prospective review of 456 cases.

Injuries to the ear, nose and throat (ENT) regions are not uncommon in clinical practice and constitute a significant cause of morbidity and mortality in our setting. There is dearth of literature on this subject in our environment. This study was conducted to describe the causes, injury pattern and outcome of these injuries in our setting and proffer possible preventive measures. This was a descriptive prospective study of patients with ear, nose and throat injuries managed at Bugando Medical Centre between May 2007 and April 2012. Ethical approval to conduct the study was sought from relevant authorities. Statistical data analysis was performed using SPSS computer software version 17.0. A total of 456 patients were studied. The median age of patients at presentation was 18 years (range 1 to 72 years). The male to female ratio was 2:1. The commonest cause of injury was foreign bodies (61.8%) followed by road traffic accidents (22.4%). The ear was the most common body region injured accounting for 59.0% of cases. The majority of patients (324, 71.1%) were treated as an outpatient and only 132(28.9%) patients required admission to the ENT wards after definitive treatment. Foreign body removal and surgical wound debridement were the most common treatment modalities performed in 61.9% and 16.2% of cases respectively. Complication rate was 14.9%. Suppurative otitis media (30.9%) was the commonest complication in the ear while traumatic epistaxis (26.5%) and hoarseness of voice (11.8%) in the aero-digestive tract were commonest in the nose and throat. The overall median length of hospital stay for in-patients was 8 days (range 1 to 22 days). Patients who developed complications and those who had associated injuries stayed longer in the hospital (P < 0.001).Mortality rate related to isolated ENT injuries was 1.3% (6 deaths). The majority of patients (96.9%) were treated successfully and only 3.1% of cases were discharged with permanent disabilities. Injuries to the ENT regions are not uncommon in our environment and foreign bodies constitute a significant cause of injury. Majority of these injuries can be prevented through public enlightenment campaigns

Nonlinear equation for curved stationary flames

A nonlinear equation describing curved stationary flames with arbitrary gas expansion $\theta = \rho_{{\rm fuel}}/\rho_{{\rm burnt}}$, subject to the Landau-Darrieus instability, is obtained in a closed form without an assumption of weak nonlinearity. It is proved that in the scope of the asymptotic expansion for $\theta \to 1,$ the new equation gives the true solution to the problem of stationary flame propagation with the accuracy of the sixth order in $\theta - 1.$ In particular, it reproduces the stationary version of the well-known Sivashinsky equation at the second order corresponding to the approximation of zero vorticity production. At higher orders, the new equation describes influence of the vorticity drift behind the flame front on the front structure. Its asymptotic expansion is carried out explicitly, and the resulting equation is solved analytically at the third order. For arbitrary values of $\theta,$ the highly nonlinear regime of fast flow burning is investigated, for which case a large flame velocity expansion of the nonlinear equation is proposed.Comment: 29 pages 4 figures LaTe

An examination of the effects of self-regulatory focus on the perception of the media richness: the case of email

Communication is a key element in organizations’ business success. The media richness theory and the channel expansion theory are two of the most influential theories regarding the selection and use of communication media in organizations; however, literature has focused little on the effects of self-regulation by managers and employees in these theories. To analyze these topics, this study develops an empirical investigation by gathering data from 600 managers and employees using a questionnaire. The results suggest that the perception of media richness is positively affected when the individual shows a promotion focus or strategy.Peer ReviewedPostprint (author’s final draft

Exactly Solvable Models: The Road Towards a Rigorous Treatment of Phase Transitions in Finite Systems

We discuss exact analytical solutions of a variety of statistical models recently obtained for finite systems by a novel powerful mathematical method, the Laplace-Fourier transform. Among them are a constrained version of the statistical multifragmentation model, the Gas of Bags Model and the Hills and Dales Model of surface partition. Thus, the Laplace-Fourier transform allows one to study the nuclear matter equation of state, the equation of state of hadronic and quark gluon matter and surface partitions on the same footing. A complete analysis of the isobaric partition singularities of these models is done for finite systems. The developed formalism allows us, for the first time, to exactly define the finite volume analogs of gaseous, liquid and mixed phases of these models from the first principles of statistical mechanics and demonstrate the pitfalls of earlier works. The found solutions may be used for building up a new theoretical apparatus to rigorously study phase transitions in finite systems. The strategic directions of future research opened by these exact results are also discussed.Comment: Contribution to the ``World Consensus Initiative III, Texas A & M University, College Station, Texas, USA, February 11-17, 2005, 21

Effect of Electron Energy Distribution Function on Power Deposition and Plasma Density in an Inductively Coupled Discharge at Very Low Pressures

A self-consistent 1-D model was developed to study the effect of the electron energy distribution function (EEDF) on power deposition and plasma density profiles in a planar inductively coupled plasma (ICP) in the non-local regime (pressure < 10 mTorr). The model consisted of three modules: (1) an electron energy distribution function (EEDF) module to compute the non-Maxwellian EEDF, (2) a non-local electron kinetics module to predict the non-local electron conductivity, RF current, electric field and power deposition profiles in the non-uniform plasma, and (3) a heavy species transport module to solve for the ion density and velocity profiles as well as the metastable density. Results using the non-Maxwellian EEDF model were compared with predictions using a Maxwellian EEDF, under otherwise identical conditions. The RF electric field, current, and power deposition profiles were different, especially at 1mTorr, for which the electron effective mean free path was larger than the skin depth. The plasma density predicted by the Maxwellian EEDF was up to 93% larger for the conditions examined. Thus, the non-Maxwellian EEDF must be accounted for in modeling ICPs at very low pressures.Comment: 19 pages submitted to Plasma Sources Sci. Techno

Feminist phenomenology and the woman in the running body

Modern phenomenology, with its roots in Husserlian philosophy, has been taken up and utilised in a myriad of ways within different disciplines, but until recently has remained relatively under-used within sports studies. A corpus of sociological-phenomenological work is now beginning to develop in this domain, alongside a longer standing literature in feminist phenomenology. These specific social-phenomenological forms explore the situatedness of lived-body experience within a particular social structure. After providing a brief overview of key strands of phenomenology, this article considers some of the ways in which sociological, and particularly feminist phenomenology, might be used to analyse female sporting embodiment. For illustrative purposes, data from an autophenomenographic project on female distance running are also included, in order briefly to demonstrate the application of phenomenology within sociology, as both theoretical framework and methodological approach