A study of the effects of environmental changes on the stress-strain properties of kaolinite

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Civil and Sanitary Engineering, 1961.Includes bibliographical references (leaves 79-80).by Anwar E. Z. Wissa.M.S

Flight Testing of Novel Compliant Spines for Passive Wing Morphing on Ornithopters

Unmanned Aerial Vehicles (UAVs) are proliferating in both the civil and military markets. Flapping wing UAVs, or ornithopters, have the potential to combine the agility and maneuverability of rotary wing aircraft with excellent performance in low Reynolds number flight regimes. The purpose of this paper is to present new free flight experimental results for an ornithopter equipped with one degree of freedom (1DOF) compliant spines that were designed and optimized in terms of mass, maximum von-Mises stress, and desired wing bending deflections. The spines were inserted in an experimental ornithopter wing spar in order to achieve a set of desired kinematics during the up and down strokes of a flapping cycle. The ornithopter was flown at Wright Patterson Air Force Base in the Air Force Research Laboratory Small Unmanned Air Systems (SUAS) indoor flight facility. Vicon motion tracking cameras were used to track the motion of the vehicle for five different wing configurations. The effect of the presence of the compliant spine on wing kinematics and leading edge spar deflection during flight is presented. Results show that the ornithopter with the compliant spine inserted in its wing reduced the body acceleration during the upstroke which translates into overall lift gains

Medical image of the week: Trousseau's sign

No abstract available. Article truncated at 150 words. A 22 year old woman was admitted for numbness and tingling of her hands, feet and face 72 hours after total thyroidectomy for a nonfunctional goiter. Initial ionized calcium was 3.2 mg/dL and magnesium 1.2 mg/dL. The patient received 1 ampule of calcium gluconate (90 mg calcium) and 2 mg MgSO4 intravenously. The next day a rapid response was called. The patient was lethargic, and said she felt very ill, although she could not be more specific. Her ionized calcium was 4.3 mg/dL. She demonstrated Trousseau's sign when her blood pressure was measured with an arm cuff (Figure 1). She also had a positive Chvostek's sign. She did not have stridor or papilledema. She received another ampule of calcium gluconate and 2 mg MgSO4 intravenously and was transferred to the ICU, where she had a 60 sec duration generalized seizure. A calcium gluconate infusion was started, that delivered 990 mg

Effective stress-strength behavior of cemented soils

Thesis (Sc. D.)--Massachusetts Institute of Technology, Dept. of Civil Engineering, 1965.Vita.Includes bibliographical references (leaves 237-239).by Anwar Ernest Zaki Wissa.Sc.D

Sympathetic empyema arising from streptococcus anginosus splenic abscess

We report a 52 year old male with a history splenic infarction, abdominal pain and shortness of breath. CT scanning revealed a splenic abcess and empyema. Cultures from both sites grew Streptococcus anginosus. These resolved with drainage and antibiotics. Physicians should consider Streptococcus species when confronted with a patient with splenic infarction

Wireless motion control of paramagnetic microparticles using a magnetic-based robotic system with an open-configuration

In this work, motion control of paramagnetic microparticles is achieved using a magnetic system with an open-configuration. This control is done using a permanent magnet and an electromagnetic coil under microscopic guidance. The permanent magnet and the electromagnetic coils are fixed to the end-effector of a robotic arm with 4 degrees-of-freedom to control the motion of the microparticles in three-dimensional (3D) space. A closed-loop control of the robotic arm is done at the joint-space to orient the magnetic field gradients of the permanent magnet and the electromagnetic coil towards a reference point in 3D space. Point-to-point motion control is achieved at an average speed of 117 ϵm/s using the permanent magnet and the robotic arm, whereas the electromagnetic coil and the robotic arm achieve average speed of 46 ϵm/s. In addition, the permanent magnet and the robotic arm achieves maximum position error of 600 ϵm, in the steady-state, as opposed to 100 ϵm for the electromagnetic coil and the robotic arm. We also demonstrate experimentally that our control system moves the microparticles towards a reference position in the presence of a constrain on the motion of the end-effector. The precise motion control of paramagnetic microparticles using a magnetic system with open-configuration provides broad possibilities in targeted therapy and biomedical applications that cannot be achieved using magnetic systems with closed-configurations