Elliptical torus cutter tool path generation based on minimum distance computation

In mould manufacture the elliptical torus cutters are used for their high cutting velocity, but the special geometry also brings issues in tool path generating and machining quality controlling. In this paper a guide curve tool path generating method for elliptical torus cutters is presented with the cutter location points computed by a minimum distance algorithm and the path spacing determined by an adaptive method. In the minimum distance algorithm, the calculation is resolved into an iterative process from point to freeform surface and an algebraic calculation process from point to elliptical torus surface considering the geometry of the cutter, which reduces the iterative process and improves the computing speed. In the adaptive path spacing method, the contacting geometry between the elliptical cutter and the workpiece surface is analysed and the relations among the scallop height, the tool tilt angle and the path spacing are deduced, based on which the guide curves are adjusted in advance to control the scallop height. Calculating examples and experiments are carried out, showing that the consuming time of cutter location (CL) points computation algorithm is reduced by 30% comparing to earlier method, and the adaptive path spacing method performs better than constant method in both scallop height controlling and tool path shortening. The results indicate that the presented tool path generating method can help to reduce both the machining and machine waiting time as well as ensuring the machining quality.

Spatial heterogeneity in discontinuation of modern spacing method in districts of India

Background Despite six decades of official family planning programme, the use of modern contraceptive method remained low in India. The discontinuation of modern spacing method (DMSM) has also increased from 42.3% in 2005−06 to 43.6% during 2015–16. Discontinuation rate is higher for Injectable (51%), followed by condom (47%), pill (42%) and lowest in IUD (26%). Methods Data from NFHS-4 (2015–16) comprising of 601,509 households, 699,686 women and a sample of 119,548 episode of modern spacing method was used for the analysis. Multiple decrement life table has used to estimate 12-month discontinuation rate of modern spacing methods (DMSM). Moran’s I statistics, Bivariate LISA cluster map has used to understand the spatial correlates and clustering the DMSM. OLS model and impact analysis has used to assess the significant associated covariates with discontinuation. Result The 12-month DMSM in India is 43.5%; largely due to desire for becoming pregnant and method failure. The high discontinuation rate was observed in most of the southern (62%) and central (46%) regions of India. DMSM has significantly and spatially associated with neighbouring districts of India (Moran’s I = 0.47, p-value = 0.00). The prevalence of modern spacing method is negatively associated with discontinuation in the neighbouring districts of India. The unmet need (β = 0.84, 95% CI 0.55–1.14), desire of children (β = 0.26, 95% CI − 0.05–0.57) and female sterilization (β = 0.54, 95% CI 0.14–0.95) were three main contributing factor to DMSM. Conclusion Districts of high DMSM need programmatic intervention. More attention for counselling to client, health worker outreach to user and better quality care services will stimulate non-user of contraception.

Progesterone only pills: an effective contraceptive option for lactating women

Background: Progesteone only pills (POP) are the most suitable for breastfeeding women as they have no effect on quality and quantity of breast milk in lactating women or on infant growth as well.Methods: A study was conducted on post partum lactating women over a period of 6 months at a tertiary care hospital in Mumbai. Post partum women were called for follow up in the post natal OPD and were counseled about temporary and permanent spacing methods.Results: Progesterone only pills are an acceptable and convenient means of temporary contraception / spacing during lactation period in motivated patients who do not want IUCDs or Injectables or are undecided about permanent methods of family planning.Conclusions: Low Dose progesterone only minipill is both effective and acceptable to breast feeding women. It may be used as a temporary spacing method in women who do not prefer an IUD but who are motivated to be complaint with its use.

Analyses of Pressure Fluctuation and Fluctuation Reduction of an Automobile Fuel Pump

The automobile fuel pump studied in this paper is a mini regenerative pump consisting of a casing with an axial channel and an impeller with 33 radial blades. In this study, the pressure fluctuation characteristics of the regenerative pump were analyzed with the method of unsteady CFD analysis. To investigate the pressure fluctuation, the unsteady Reynolds-averaged Navier-Stokes equations (URANS) were solved with realizable k-ε turbulence model using the CFD code FLUENT. To study the effect of arc length of stripper on the pressure fluctuation, the pressure fluctuations at several locations of pumps with strippers of different arc length were analyzed in time and frequency domain. The static pressure contours at different times were presented to reveal the generating mechanism of pressure fluctuation of the regenerative pump. For the purpose of pressure fluctuation reduction, a random modulation of blade spacing method was applied to design a new impeller with uneven spaced blades. The pressure fluctuations of four different pump units of the combination of different blade distribution impellers with casings of different arc length of stripper were studied and discussed. The pressure fluctuation of the pump unit of combination of random blade distribution impeller and large arc length stripper is significantly reduced. In this paper, the generating mechanism of pressure fluctuation for regenerative pump is uncovered, and a good solution to the fundamental pressure fluctuation reduction of regenerative pump is put forward.

Unfolding the Mystery of Reliance on Traditional Methods of Birth Control in Assam, India

Reliance on traditional methods of birth control causes psychological tension in couples because the fear of unwanted pregnancy bars them from experiencing a healthy sexual life. However, in Assam, half of all contraceptive users depend on traditional methods of birth control. The current study used National Family Health Survey 2005–2006 data. Out of 3840 sample women in the age group 15–49 years, 1286 women are filtered for the present study. Most of the demographic and socioeconomic characteristics of traditional method users fall between those of modern spacing method users and terminal method users. Thus, the burden of unwanted fertility is highest among the traditional method users.