Rotem Industries Ltd.

Arava, Israel

Rotem Industries Ltd.

Arava, Israel
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Ginzburg D.,Rotem Industries Ltd
Radiation Protection Dosimetry | Year: 2017

The use of pulsed photon radiation in medical, industrial and security sectors has vastly increased during the recent years. The length of pulse from different X-ray flash generators that are commonly used as either portable, battery-operated or fixed systems can be as low as a few femtoseconds. However, the majority of radiation protection instruments, especially various active electronic dosemeters, have limitations when operated in pulsed fields. This study presents measurements that were performed using the dose-integration mode of the RI-02 and Ram Ion survey metres, which are based on ventilated ionisation chamber, when exposed to different pulsed X-ray sources. An intercomparison between the results that were obtained with the survey metres and those that were obtained with thermoluminescence dosemeter, reference passive dosemeter, show good agreement (deviation lies within 10%). © The Author 2016.

Agency: European Commission | Branch: H2020 | Program: MSCA-ITN-ETN | Phase: MSCA-ITN-2014-ETN | Award Amount: 3.96M | Year: 2015

NMR and MRI play unique roles in contemporary Science, from Physics, Chemistry and Biology, to clinical research and diagnosis. Despite its irreplaceable role, further progress in NMR and MRI is hampered by sensitivities that are much lower than those of alternatives such as mass-spec, or PET. The prospects of solving this problem by bigger machines are uncertain and of poor return, given the high maturity already achieved by NMR/MRI. This ETN challenges this status from an untapped perspective, combining NMR/MRI with nuclear hyperpolarization eliciting signals that surpass those currently available by up to 50,000x. Focus is placed on two particular approaches, dynamic nuclear polarization and para-hydrogen-driven polarization, exhibiting the highest potential for biophysical, metabolomic, pre-clinical and clinical research. To maximize these supersignals we assembled leading experts in the physics and engineering of magnetic resonance, in the synthetic chemistry essential for the success of these methods, in the uses of NMR to structural/cell biology, and in preclinical and clinical MRI applications. Guiding this assembling is the conception that only by teaming together key areas of expertise, can hyperpolarisations promises be realized. In addition to fostering synergies among experts from academia and industry, EUROPOL will provide frontier training for ESRs in all the topics underlying the advancement of MR. This will include advanced physics, new instruments and forms of exploiting NMR/MRIs hyperpolarisation, biophysical NMR, screening of healthy and diseased metabolomes, expanded portfolios of substrates to be targeted by in vivo MR, ancillary in cell and system biology explorations clarifying the nature of the metabolic phenomena, and in vivo hyperpolarisation strategies in MRI. This ETN is unparalleled in scope, breadth and potential for synergies.

Haroush S.,Nuclear Research Center - Negev | Haroush S.,Ben - Gurion University of the Negev | Priel E.,Sami Shamoon College of Engineering | Priel E.,Rotem Industries Ltd. | And 6 more authors.
Materials and Design | Year: 2015

Thin foils having thickness values of 200. μm and less are commonly applied in the food industries, medical applications and more. Small punch technique (SPT) is a promising mechanical testing method for specimens thicker than 250. μm, in which a formulation correlating the measured parameters to standard tensile properties was previously reported. The current research is focused, for the first time, on the correlation between SPT and tensile mechanical properties of SS-316L thinner specimens in the range of 100-200. μm. It is demonstrated by finite-element-analysis, that the mechanical response of thin foils having thicknesses in the range of 25-500. μm can be divided into three categories. For specimens thicker than 300. μm, thin plate bending equations that were applied previously for thick specimens, are still valid, while for thinner specimens this theory fails to provide adequate correlation between SPT and tensile yield stress. For specimens thinner than 50. μm it was identified that equations derived from membrane solution should be employed rather than classical plate theory. For intermediate thickness values in the 50-300. μm range, a "transition-zone" was identified between plate and membrane-like mechanical responses. For the lower region, 50-100. μm, an analytical expression correlating the measured SPT parameters and the tensile yield stress is currently proposed. © 2015 Elsevier Ltd.

Ilberg L.,Technion - Israel Institute of Technology | Manis-Levy H.,Ben - Gurion University of the Negev | Raveh A.,Rotem Industries Ltd. | Lifshitz Y.,Technion - Israel Institute of Technology | Varenberg M.,Technion - Israel Institute of Technology
Diamond and Related Materials | Year: 2013

A comparative study of the tribological properties of a library of different carbon forms is presented. The library includes hydrogen free and hydrogenated carbon films with different bonding (CC, CH, different sp 3 fractions) and structure configurations (amorphous, graphitic) leading to a wide range of densities and hardness. Reference samples (Si substrates, thermally evaporated amorphous carbon, graphitic foil) were studied as well. The tribological properties were measured using a reciprocal sliding tribometer under humid (50% RH) and dry (5% RH) air conditions. Friction coefficients were measured versus the number of sliding cycles and the wear was studied using optical profilometry and imaging as well as SEM. The friction and wear performance of the carbon films were found to depend on both the structure and the ambient conditions. Hydrogen free films have friction coefficients < 0.1 for 80% sp3 bonded films and > 0.1 for 100% sp2 bonded films. The wear resistance of the hydrogen free films (much larger for sp3 bonded films) significantly decreases under dry conditions. In contrast, hydrogenated films show reduction in friction with decreasing humidity (from 0.2 under 50% RH to < 0.1 under 5% RH). The wear resistance of hydrogenated films is larger for dry and smaller for humid conditions. © 2013 Elsevier B.V.

Ghelman M.,Nuclear Research Center - Negev | Paperno E.,Ben - Gurion University of the Negev | Ginsburg D.,Rotem Industries Ltd. | Mazor T.,Nuclear Research Center - Negev | And 2 more authors.
Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment | Year: 2011

A novel spectroscopic personal radiation device (SPRD) with sub-milliwatt power consumption is proposed. The SPRD is based on a compact, low-power, high-gain silicon photomultiplier (SiPM) coupled to a high-light-yield CsI(Tl) scintillator. The SiPM is operated in a special mode, in which its output is voltage rather than charge. In this mode, the SiPM output becomes higher and rises more slowly than in the charge amplification mode. Such a mode allows us to use a lower-frequency front-end amplifier with a lower gain and lower power consumption. Moreover, the very beginning of the slower, large-amplitude pulses is easier to detect with a comparator. At each detection event, the rest of the SPRD circuitry is activated only for the time needed for the pulse-processing. Because at background the radiation count rate is very low, some tens per second, and the duration of the signal-processing is very short, about 10 μs, the power-demanding SPRD circuitry is not activated most of the time, and its average power consumption is very low. Proper matching of the scintillator and the SiPM helps us to achieve the required gain from the radiation sensor with a relatively low-power, low-gain front-end amplifier. Optimizing the input impedance of the front-end amplifier helps us to obtain the required SiPM output amplitude and shape. Because it takes some time for the signal processing circuit to be activated, an additional passive delay and shaping circuit is used. An experimental model of this device is built, and tested. It is superior to other devices due to its very low power consumption, its portability, and its non-sensitivity to microphonics. The power consumption of the SPRD is about 0.3 mW by the radiation sensor and about 0.3 mW by the electronics (for a total of 0.6 mW as compared to above 20 mW consumed by conventional spectroscopic radiation devices). The power consumption has been measured at count rates up to a few hundreds per second, which are much higher than expected in practice. © 2010 Elsevier B.V.

Priel E.,Sami Shamoon College of Engineering | Priel E.,Rotem Industries Ltd. | Ungarish Z.,Ben - Gurion University of the Negev | Ungarish Z.,Nuclear Research Center - Negev | Navi N.U.,Nuclear Research Center - Negev
Journal of Materials Processing Technology | Year: 2016

A coupled finite element analysis in conjunction with experiments was used to investigate hot co-extrusion of a novel composite Mg AZ80/Al 1100 billet assembly. To validate the computational model, results from both radiography, and metallography were used. It is demonstrated that the billet configuration proposed in this study results in a uniform composite rod, with no indication of cracks, tears, wavy interface surfaces or voids. The computational model is first validated by the experiments and then used to thoroughly study the thermo-mechanical fields that develop during the co-extrusion process. The interplay of the thermal and mechanical fields during the process is examined for different initial temperatures, die angle and ram velocity. It is demonstrated that using the proposed billet assembly, constant compressive radial stress develops across the magnesium core, leading to sound-proportional flow conditions. © 2016 Elsevier B.V.

Ben-Artzy A.,Rotem Industries Ltd. | Stern A.,Ben - Gurion University of the Negev | Frage N.,Ben - Gurion University of the Negev | Shribman V.,Pulsar Ltd. | Sadot O.,Ben - Gurion University of the Negev
International Journal of Impact Engineering | Year: 2010

Wavy interface morphology is observed in Magnetic Pulse Welding (MPW) similarly to that of the Explosion Welding process (EXW). It is recognized that interfacial waves are formed in a periodic manner and have well defined wavelength and amplitude. The phenomenon of wave formation in EXW has been subjected to extensive investigations in which empirical and numerical models have been published. In the present study, a wave formation mechanism for MPW is presented. This wave-creation mechanism was studied by evaluating the influence of sample geometry on wave morphology using stereoscopic optical microscopy. It was found that interfacial waves are formed in a Kelvin-Helmholtz instability mechanism. Reflected shock waves interact with the welding collision point at the weld interface, where interferences are the source for the wave's initiation. The collision energy, impact angle, and the geometry of the joint, were found to have the most significant influence on the waves' characteristics. An empirical relationship between interfacial wavelength and the free moving distance of the shock waves in the welded tubular parts was found. © 2009 Elsevier Ltd. All rights reserved.

Portman V.T.,Ben - Gurion University of the Negev | Chapsky V.S.,Ben - Gurion University of the Negev | Shneor Y.,Ben - Gurion University of the Negev | Shneor Y.,Rotem Industries Ltd | Ayalon E.,Ben - Gurion University of the Negev
Procedia CIRP | Year: 2015

Stiffness of mechanical systems of machines with heavy demands on their accuracy, precision and productivity such as machine tools, coordinate measuring machines, and industrial robots presents one of the most important design criteria. However, stiffness evaluation in the general case when force-and-torque load coupling takes place leads to some problems. The problems are associated with physical distinction between translational and rotational stiffness values manifested, in particular, in their different units of measurement. To overcome a majority of the difficulties, a new performance index - the collinear stiffness value (CSV) presenting an equivalent stiffness (compliance) value during simultaneous linear and rotational displacements - is developed and represented in static and dynamic versions. In this presentation, the CSV is used to formulate a new design-related dimensionless criterion: the ratio of the minimal CSV to stiffness value of the drive system, which usually presents a weak point of the modern machines. The CSV-based approach is applied to quantitative formulation of the significant advantage from the stiffness viewpoint of the orthogonal serial-kinematics machines (SKM) compared with the parallel-kinematics machines (PKM): (a) the parameters-of-motion-depending variations of the minimal CSV of the SKM in their workspace are, as a rule, one-two orders of magnitude less than those of the PKMs; (b) the stiffness-limited workspace of the SKM is more than that of the PKM. Application examples are simulated. © 2015 The Authors.

Ben-Artzy A.,Rotem Industries Ltd. | Hector Jr. L.G.,General Motors | Krajewski P.E.,General Motors
Magnesium Technology | Year: 2010

Three- and four-point bending tests of miniature extruded bars of magnesium alloys AZ31, AZ61, AM50 and ZM21 were conducted at selected orientations relative to the extrusion direction. Four-point bending was designed to give a plane strain state between the fixture pivots. Displacement and load data were acquired with external controller electronics and custom data acquisition software. High resolulion digital images of one surface of each specimen were recorded during deformation with a variable framing rate high speed digital camera. Post-processing of the image data with a digital image correlation algorithm resulted in strain contour maps from which the simultaneous evolution of tensile and compressive strains in both bending schemes was quantified. Bending strains were found to be sensitive to Mg alloy composition and orientation, and tensile bending data was in good agreement with uniaxial tensile tests.

Krajewski P.E.,General Motors | Ben-Artzy A.,Rotem Industries Ltd.
Magnesium Technology | Year: 2010

The elevated temperature tensile behavior of AZ31, AM50, ZM21, ZK10, and ZK30 direct extruded magnesium sheets was investigated. Uniaxial tensile testing to failure and step strain rate testing were performed at 400°C and 450°C to determine the effect of alloy composition and microstructure on elevated temperature ductility, strain rate sensitivity, and fracture behavior. Ductilities of almost 300% were observed in the as-extruded material with the ZK alloys giving the highest ductility. The high ductility of the ZK materials was due, in part, to their ability to maintain a relatively fine grain size throughout tensile testing. The stress exponent, n, for dislocation creep was affected by aluminum content as was the amount of grain boundary sliding. These results will be discussed in the context of designing improved alloys for elevated temperature forming processes.

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