Water distillation using waste engine heat from an internal combustion engine

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2006.Includes bibliographical references (leaf 36).To meet the needs of forward deployed soldiers and disaster relief personnel, a mobile water distillation system was designed and tested. This system uses waste engine heat from the exhaust flow of an internal combustion engine to vaporize water for the purpose of removing impurities. The vapor is condensed back down to water in a finned condenser that experiences forced convection. The system pumps heat transfer oil through a 0.61 meter long, cross flow, annulus-type heat exchanger installed over a section of exhaust pipe where the oil experiences a AT of 7°C. The hot heat transfer oil is then piped to a boiler where it releases its heat to the water and returns to the exhaust heat exchanger to be reheated. Testing demonstrated that the system has a heat up time of 30 minutes, and a steady state distillation rate of 2 gallons per hour. In steady state, the system removes and transfers heat from the exhaust at a rate of 4600 Watts.by Kevin S. Mears.S.B

Machu Picchu from an Engineer\u27s Perspective

Machu Picchu is a masterpiece of Incan civil engineering and architecture. It took much skill to build it up high in the mountains and make it stay together for this many years. It is very pleasing to the eye; as Ruth Wright puts it, Even the buildings of Machu Picchu were in harmony with the mountain backdrop. (caption before 15) Some of the many other elements that make it stand out are the simple construction tools used, the excellent stonework, the ingenious water supply, and the splendid Temples of the Sun, the Condor, and the Three Windows

Symptomatic scrotoliths in a child

Amelanotic/hypomelanotic variant of cellular blue naevus (CBN) can present a challenge for the clinician and histopathologist. We report a case of amelanotic/hypomelanotic variant of CBN that presented as a painless scrotal swelling in a child. We review the literature on amelanotic/hypomelanotic CBN, the key histological features and important differential diagnoses

Real-time identification of sliding friction using LabVIEW FPGA

Friction is present in all mechanical systems, and can greatly affect system stability and control in precision motion applications. In this paper, we present application of a frictional model to trajectory planning of a part centering system with real-time identification of model parameters through system force and position response. This identification is carried out using LabVIEW motion control software and digital signal processing (DSP) and field-programmable gate array (FPGA) hardware. A comparison of hardware performance for force measurement is also made

Interned or Imprisoned?: The Successes and Failures of International Law in the Treatment of American Internees in Switzerland, 1943-45

During World War II, over 100,000 soldiers of various nationalities sought refuge in neutral Switzerland, including over 1,500 American airmen from damaged U.S. bombers. As a result of the U.S. violations of Swiss neutrality and other external factors, the Swiss government was unwilling to apply the 1929 Geneva Convention prisoner of war protections to the interned U.S. airmen when they were punished for attempting escape. The politicization of internment procedures resulted in a diplomatic stalemate in which the ambivalence of Swiss officials prolonged mistreatment of U.S. airmen in apparent repudiation of emerging customary international law. The stalemate produced a range of responses, revealing that some Swiss officials and citizens disagreed with their government's internment policies and sought to apply prisoner of war protections to internees. Answering the question of how international law functioned in the scenario of Swiss internment demonstrates the cultural importance of Swiss adherence to humanitarian traditions, the process by which governments and individuals seek to influence aberrant state practice, and how many hidden influences combine to enforce customary rules.Doctor of Philosoph

Interned or imprisoned?: the successes and failures of international law in the treatment of American internees in Switzerland, 1943-45

During World War II, over 100,000 soldiers of various nationalities sought refuge in neutral Switzerland, including over 1,500 American airmen from damaged U.S. bombers. As a result of the U.S. violations of Swiss neutrality and other external factors, the Swiss government was unwilling to apply the 1929 Geneva Convention prisoner of war protections to the U.S. airmen when they were punished for attempting escape. The politicization of internment procedures resulted in a diplomatic stalemate in which the ambivalence of Swiss officials prolonged mistreatment of U.S. airmen in violation of emerging customary international law. I believe that answering the question of how international law functioned in the scenario of Swiss internment will demonstrate both the cultural importance of Swiss adherence to international law, as well as the process by which states frequently interpret ambiguous international law to their advantage

Modeling the power flow in normal conductor-insulator-superconductor junctions

Normal conductor-insulator-superconductor (NIS) junctions promise to be interesting for x-ray and phonon sensing applications, in particular due to the expected self-cooling of the N electrode by the tunneling current. Such cooling would enable the operation of the active element of the sensor below the cryostat temperature and at a correspondingly higher sensitivity. It would also allow the use of MS junctions as microcoolers. At present, this cooling has not been realized in large area junctions (suitable for a number of detector applications). In this article, we discuss a detailed modeling of the heat flow in such junctions; we show how the heat flow into the normal electrode by quasiparticle back-tunneling and phonon absorption from quasiparticle pair recombination can overcompensate the cooling power. This provides a microscopic explanation of the self-heating effects we observe in our large area NIS junctions. The model suggests a number of possible solutions

Electron cyclotron mass in undoped CdTe/CdMnTe quantum wells

Optically detected cyclotron resonance of two-dimensional electrons has been studied in nominally undoped CdTe/(Cd,Mn)Te quantum wells. The enhancement of carrier quantum confinement results in an increase of the electron cyclotron mass from 0.099$m_0$ to 0.112$m_0$ with well width decreasing from 30 down to 3.6 nm. Model calculations of the electron effective mass have been performed for this material system and good agreement with experimental data is achieved for an electron-phonon coupling constant $\alpha$=0.32

Recidivism and Time Served in Prison

A justification for lengthier stays in prison stems from the belief that spending more time in prison reduces recidivism. Extant studies, however, have provided limited evidence for that belief and, indeed, suggest the effect of time served may be minimal. Few studies have employed rigorous methodological approaches, examined time spans of more than one to two years, or investigated the potential for the relationship between recidivism and time served to be curvilinear. Drawing on prior scholarship, this paper identifies three sets of hypotheses about the functional form of the time served and recidivism relationship. Using generalized propensity score analysis to examine data on 90,423 inmates released from Florida prisons, we find three patterns: greater time served initially increases recidivism but then, after approximately one year, decreases it, and, after approximately two years, exerts no effect; estimation of the effects associated with durations of more than five years are uncertain. The results point to potential criminogenic and beneficial effects of time served and underscore the need to identify how varying durations of incarceration affect recidivism