59 research outputs found
Kinetics of phase boundaries with edges and junctions in a three-dimensional multi-phase body
No full textThe propagation of phase boundaries that intersect other phase boundaries at junctions and physical boundaries at edges in a three-dimensional multi-phase body is examined. The driving forces that govern the propagation of these phase boundaries, edges and junctions are calculated, and kinetic relations consistent with the second law of thermodynamics are proposed. This work extends the two-dimensional situation discussed previously (Simha, N.K., Bhattacharya, K., 1998. J. Mech. Phys. Solids, 46, 2323–2359)
"Simha Rotem (1924-2018): Ad memoriam. The broom and the resilience"
No full textSimha Rotem was born in Warsaw in 1924. He was one of the most important member of the Warsaw
Ghetto uprising in April 1943. Under the cover name of Kazik. He was a leader of the young Jews who were one of the
first in Europe to rebel against the Nazi occupation. His original name is Symon Rathajzer, who upon his arrival in
Israel he changed in Simha Rotem to symbolize a new beginning. His heroic and history is full of anecdotes that
encroach of the unbelievable. Rotem came in and out of the ghetto, through the city’s sewers, besieged and burned, to
bringing news and organizing the escape of the few survivors. Thanks to him the last fighters of the ghetto succeeded in
acriding the “Aryan” area of the city, finding refuge from not Jewish people connected with the Polish resistance. In
1944 Rotem fighted in the Warsaw uprising against the Nazi occupation. He was one of the leader of the Jewish exodus
from Poland to Israel. He contributed to save thousands of people. The author died in Jerusalem in 2018
Crystallography of the Tetragonal → Monoclinic Transformation in Zirconia
No full textThe tetragonal to monoclinic (t → m) transformation in zirconia occurs through two paths; transformation along path I has two Bain strains that involve shearing of a rectangular face of the tetragonal unit cell, and shearing of the square base corresponds to path II. The monoclinic variants resulting from each of the three Bain strains can form 12 twins, and four of the twins corresponding to path II are neither of type I nor of type II. Habit planes do not exist for the transformation along path I, whereas transformation along path II has: (±0.8139, ±0.3898,-0.4309)t' (±0.6489, ±0.6271,-0.4309)t' (±0.7804, ±0.4530,-0.4309)t
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Yemeni Jewish identity in the works of Simha Zaramati Asta
No full texttextIn this paper, I consider the collection of short stories and photographs Neighborhood Album A by Yemeni Israeli author Simha Zaramati Asta. I argue that Asta contributes to a distinctively Yemeni Jewish literature and identity in Israel. While Asta could be considered a Mizrahi author, I claim that a study of Asta’s text as Mizrahi in fact erases the distinctive Yemeni elements of Asta’s writing. Instead, Asta is purposeful about her inclusion of Yemeni culture and her establishment of Yemeni identity in her text. This Yemeni culture is evident in Asta’s inclusion of the songs of Yemeni Jewish women which constitute an oral tradition of memory within Yemen and Israel. Asta further creates a distinctive Yemeni identity through a sense of place in the Yemeni Quarter of Tel Aviv in both her stories and photographs. Through descriptions of the sights, smells, and traditions of the Yemeni Quarter of Tel Aviv, Asta elevates the neighborhood, claiming it as a place where the divine spirit can be found. While Asta is purposeful in her creation of a distinctively Yemeni Jewish literature and identity, she demonstrates the hybridization of this Yemeni Jewish literature and identity with Israeli literature and identity. By noting the importance of Yemeni Jews to the creation of Israel and the influence of Israel on these Yemeni Jews, Asta claims Israeli identity for Yemeni Jews. She demonstrates the hybridization of the Yemeni Jewish identity and Israeli identity through intertextual references to canonical Israeli poets and authors. Yet while Asta values this hybridization, she uses the characters in her stories to question whether the hybridization of Yemeni Jews in Israel can in fact succeed.Middle Eastern Studie
Switched Control Strategy for Robust Formation Flight with HIL and In-Flight Validation
No full textIn recent times, Unmanned Aerial Vehicles (UAVs) have been intensively studied for a wide range of military and civil applications such as surveillance and reconnaissance missions, agriculture, traffic monitoring, pollution control, meteorological data collection, pipeline survey, early fire detection, rescue missions, wildlife population monitoring, etc. The above tasks can be carried out faster and more efficiently by a group of UAVs flying in formation. This paper presents the application of two stage switching controller in autonomous formation flight of UAVs based on the leader follower configuration. The constructed UAV airframe, as well as the autopilot, formation flight control unit and wireless communication link for data sharing between UAVs were presented and described. The advantages of the switched control were demonstrated in terms of a significantly larger region of stability in maintaining formation, as opposed to the standard, one stage control laws with classical compensators. Hardware In The Loop (HIL) tests of proposed formation flight control were performed, during which the inertial states and flight parameters were logged. The HIL test rig enabled us to verify the formation flight control performance which was further substantiated by actual flight tests.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Embedded System
Edge effects on the propagation of phase boundaries
No full textThis paper shows that the kinetics of a phase boundary can be profoundly influenced by the conditions at the edges where it meets other phase boundaries, grain boundaries or the physical boundary of the body
Evaluating different localization methods for robotic swarming
No full textLocalization is an important element for a moving swarm of robots. A swarm contains many individuals, and it is essential that the swarm members do not collide. Expensive and complex implementations to localize others is undesirable. Hence, a localization system designed using the available resources is desired. The available techniques that have been analysed are Received Signal Strength Indicator (RSSI), Time difference of arrival (TDOA) using the ESP-NOW protocol and a spinning time of flight (TOF) sensor. The spinning TOF sensor showed to be the most promising, with close range distance detection only containing a maximum errors of 5cm. The sensor is implemented as a cheap LiDAR system by mounting it to the front of the robot, which spins around its own axis. An IMU is responsible for keeping track of the orientation of the TOF sensor. Furthermore, two small algorithms were designed and compared in order to process the TOF data.Electrical Engineerin
Equilibrium conditions at corners and edges of an interface in a multiphase solid
No full textIn various situations such as coherent precipitation, martensitic transformation, recrystallization, and grain growth the kinetics of phase boundaries play a crucial role in determining the microstructure and the resulting macroscopic properties. By performing a variational calculation in a two dimensional setting, we find the equilibrium conditions at corners, where two interfaces meet, and at edges, where an interface meets the boundary of a finite body. We allow for possible singularities in the bulk stress at corners and edges. The general case considers elastic energy for the bulk and anisotropic energies for the surfaces. Special cases treated are: (i) constant bulk energy or purely surface case; (ii) purely elastic case or zero surface energy; and (iii) constant surface energy
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