Theoretical and experimental analysis of the backward extrusion process with a rotational die of AZ31 alloy

In this work theoretical and experimental analysis of the backward extrusion with a rotary die of the AZ31 alloy has been performed. The modification of the classical extrusion was based on the use of a rotary die. The results of theoretical research have confirmed that the use of the modified backward extrusion causes the appearance of shear stress in deformed material, which could affects the activation of additional mechanisms of deformation. The numerical modelling of the rotating extrusion of AZ31 alloy has been conducted by using the computer program Forge®. The experimental tests were carried out in the conditions of the STD 810 torsion plastometer using newly designed tools

The prevention of infertility of mares

In the article it is noted that when the age of physiological maturity is reached, most of mares do not go hunting because of genital infantilism. The authors' studies showed that in the group where the repair filly had a systematic communication with the vasectomized stallions at 36 months of age, the reproductive apparatus was well developed, there were no signs of genital infantilism. All mares were found at the age of 36–37 months, and they became foal, at the mares of the control group at the indicated age the sexual cycles did not appear regularly, signs of genital infantilism were noted. The authors note that the vasectomized stallion provides, normal development of the reproductive sexual system of the repair mares, the full formation and manifestation of sexual cycles. The use of vasectomized stallions allows for an early effective prevention of genital infantilism and infertility in repair mares. Dosed communication of fillies with vasectomized colts and sterile coitus during sexual development promoted the physiological development of the genitals and the full manifestation of the sexual cycle

Line Broadening in Field Metal-poor Red Giant and Red Horizontal Branch Stars

We report 349 radial velocities for 45 metal-poor field red giant and red horizontal branch stars. We have have identified one new spectroscopic binary, HD 4306, and one possible such system, HD 184711. We also report 57 radial velocities for 11 of the 91 stars reported on previously by Carney et al. (2003). As was found in the previous study, radial velocity "jitter" is present in many of the most luminous stars. Excluding stars showing spectroscopic binary orbital motion, all 7 of the red giants with M(V) <= -2.0 display jitter, as well as 3 of the 14 stars with -2.0 <= M(V) <= -1.4. We have also measured line broadening in all of the new spectra, using synthetic spectra as templates. The most luminous red giants show significant line broadening, as do many of the red horizontal branch stars, and we discuss briefly possible causes.Comment: To appear in the Astronomical Journa

The theoretical and experimental analysis of the possibility of employing the groove rolling process for the manufacture of Mg/Al bimetallic bars

The paper presents the results of investigation into the possibility of employing the groove rolling process to produce round Mg/Al bimetallic bars. The feedstock were round 22,5 mm Mg/Al bars that had been produced using the explosive welding method. The average thickness of the aluminium layer amounted to 1,7 mm. The Mg/Al bars were rolled in the stretching rolling passes. The theoretical analysis was done using the Forge2011® computer program. Based on the theoretical and experimental analysis it has been found that one of the main rolling process parameters influencing the quality of bond between the bimetal components is the initial feedstock temperature

Kompjutersko i laboratorijsko modeliranje analize sprečavanja metalurških grešaka na ingotima tijekom slobodnog toplog kovanja

Computer modelling using a FEM-based program, Forge 2DŇ, was carried out in the study. The influence of die shape and the main parameters of the forging process on closing up of metallurgical defects were determined.U studiji je provedeno kompjutorsko programiranje uporabom programa Forge 2DŇ temeljenog na MKE. Laboratorijsko modeliranje procesa slobodnog toplog kovanja u profilnim nakovnjima provedeno je radi sprečavanja metalurških kvarova. Rezultati dobiveni simulacijom i laboratorijskim modeliranjem obrađeni su uporabom komercijalnih paketa za statističku obradu, Statistica 6.0® PL. Utvrđen je utjecaj oblika matrica i glavnih parametara procesa kovanja na sprečavanju metalurških grešaka

Two 'b's in the Beehive: The Discovery of the First Hot Jupiters in an Open Cluster

We present the discovery of two giant planets orbiting stars in Praesepe (also known as the Beehive Cluster). These are the first known hot Jupiters in an open cluster and the only planets known to orbit Sun-like, main-sequence stars in a cluster. The planets are detected from Doppler shifted radial velocities; line bisector spans and activity indices show no correlation with orbital phase, confirming the variations are caused by planetary companions. Pr0201b orbits a V=10.52 late F dwarf with a period of 4.4264 +/- 0.0070 days and has a minimum mass of 0.540 +/- 0.039 Mjup, and Pr0211b orbits a V=12.06 late G dwarf with a period of 2.1451 +/- 0.0012 days and has a minimum mass of 1.844 +/- 0.064 Mjup. The detection of 2 planets among 53 single members surveyed establishes a lower limit on the hot Jupiter frequency of 3.8 (+5.0)(-2.4) % in this metal-rich open cluster. Given the precisely known age of the cluster, this discovery also demonstrates that, in at least 2 cases, giant planet migration occurred within 600 Myr after formation. As we endeavor to learn more about the frequency and formation history of planets, environments with well-determined properties -- such as open clusters like Praesepe -- may provide essential clues to this end.Comment: 5 pages, 3 tables, 2 figures. Published in ApJ Letter

[Accepted Manuscript] Lessons learned from implementing Indashyikirwa in Rwanda- an adaptation of the SASA! approach to prevent and respond to intimate partner violence.

This paper reviews adaptation processes of the Indashyikirwa program in Rwanda, a four-year program to prevent intimate partner violence, implemented by CARE Rwanda, Rwanda Men's Resource Center (RWAMREC) and Rwanda Women's Network (RWN). Indashyikirwa is a blended approach of evidence-based programming, primarily drawing on SASA! developed by Raising Voices in Uganda, as well as program innovations. Indashyikirwa consists of four major components; 1) a five-month curriculum with couples to support equitable, non-violent relationships, 2) supporting a sub-set of trained couples to engage in community activism for an additional two years, 3) establishment of women's safe spaces for dedicated support and referral of IPV survivors, 4) training and engaging opinion leaders to support an enabling environment for IPV prevention and response. This paper is based on implementation experience and qualitative evaluation research conducted at various time points with trained couples, women's safe space attendees and facilitators, opinion leaders and programme staff, as well as observations of program activities. The SASA! fidelity brief, which highlights key principles for adaptation of the program, guided the framing of the findings. Lessons learned around adaptation of such programs are offered

Asteroseismology of the Hyades with K2: first detection of main-sequence solar-like oscillations in an open cluster

The Hyades open cluster was targeted during Campaign 4 (C4) of the NASA K2 mission, and short-cadence data were collected on a number of cool main-sequence stars. Here, we report results on two F-type stars that show detectable oscillations of a quality that allows asteroseismic analyses to be performed. These are the first ever detections of solar-like oscillations in main-sequence stars in an open cluster.Comment: 12 pages, 8 figures, 2 tables; accepted for publication in MNRA

HAT-P-5b: A Jupiter-like hot Jupiter Transiting a Bright Star

We report the discovery of a planet transiting a moderately bright (V = 12.00) G star, with an orbital period of 2.788491 +/-0.000025 days. From the transit light curve we determine that the radius of the planet is Rp = 1.257 +/- 0.053 RJup. HAT-P-5b has a mass of Mp = 1.06 +/- 0.11 MJup, similar to the average mass of previously-known transiting exoplanets, and a density of rho = 0.66 +/- 0.11 g cm^-3 . We find that the center of transit is Tc = 2,454,241.77663 +/- 0.00022 (HJD), and the total transit duration is 0.1217 +/- 0.0012 days.Comment: 5 pages, submitted to APJ

Hat-P-25b: A Hot-Jupiter Transiting a Moderately Faint G Star

We report the discovery of HAT-P-25b, a transiting extrasolar planet orbiting the V = 13.19 G5 dwarf star GSC 1788-01237, with a period P = 3.652836 ± 0.000019 days, transit epoch T_c = 2455176.85173 ± 0.00047 (BJD—barycentric Julian dates throughout the paper are calculated from Coordinated Universal Time, UTC), and transit duration 0.1174 ± 0.0017 days. The host star has a mass of 1.01 ± 0.03 M_☉, radius of 0.96^(+0.05)_(– 0.04) R_☉, effective temperature 5500 ± 80 K, and metallicity [Fe/H] = +0.31 ± 0.08. The planetary companion has a mass of 0.567 ± 0.022 M_J and radius of 1.190^(+0.081)_(–0.056) R_J yielding a mean density of 0.42 ± 0.07 g cm^(–3)