1,556 research outputs found
Creating a sustaining value engineering function within worldwide manufacturing
Thesis (M.B.A.)--Massachusetts Institute of Technology, Sloan School of Management; and, (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering; in conjunction with the Leaders for Manufacturing Program at MIT, 2008.Includes bibliographical references (p. 59).Most product cost reduction in industry occurs during new product introduction (NPI). However, for some firms, a case can be made that product cost reduction efforts can be devoted towards products already in sustained production. These firms face a set of business conditions that often preclude exhaustive product cost reduction during NPI. These conditions include fast time to market requirements and the necessity of devoting engineering resources to a pipeline of innovative products needed to remain competitive in the market. These firms' products also possess characteristics that make cost reduction during sustained production viable. Products have sufficiently long lifecycles in which to realize project savings and a market that will continue paying prices that enable continued profitability. However, as expected, these firms often must devote resources to more pressing NPI needs, leaving sustained product cost reduction savings under-realized.Cisco Systems is a firm that faces these business conditions and has products that have these characteristics. Cisco Worldwide Manufacturing has thus devoted itself to improving Cisco's value engineering capabilities to a world class level. Value engineering at Cisco refers to product cost reduction activities that occur during sustained manufacturing. The research in this thesis set out to validate the hypothesis that Cisco could improve value engineering savings by funding cost reduction projects directly through Worldwide Manufacturing, rather than through the typical budget of a Cisco business unit. Cisco business units often have to prioritize NPI over value engineering. This thesis will discuss the process and results of a model that was established to provide value engineering project funding through Manufacturing. Results show that value engineering savings can be increased with this funding model.by James P. Thome.S.M.M.B.A
Saturated Critical Heat Flux in a Multi-Microchannel Heat Sink Fed by a Split Flow System
An extensive experimental campaign has been carried out for the measurement of saturated critical heat flux in a multi-microchannel copper heat sink. The heat sink was formed by 29 parallel channels that were 199 μm wide and 756 μm deep. In order to increase the critical heat flux and reduce the two-phase pressure drop, a split flow system was implemented with one central inlet at the middle of the channels and two outlets at either end. The base critical heat flux was measured using three HFC Refrigerants (R134a, R236fa and R245fa) for mass fluxes ranging from 250 to 1500 kg/m2 s, inlet subcoolings from −25 to −5 K and saturation temperatures from 20 to 50 °C. The parametric effects of mass velocity, saturation temperature and inlet subcooling were investigated. The analysis showed that significantly higher CHF was obtainable with the split flow system (one inlet–two outlets) compared to the single inlet–single outlet system, providing also a much lower pressure drop. Notably several existing predictive methods matched the experimental data quite well and quantitatively predicted the benefit of higher CHF of the split flow
EOS Contract Report: The ASTER and MODIS Projects
Three major tasks occupied the group's efforts during this six months. The first was measuring the bidirectional reflectance properties of four reflectance samples provided by NIST. S. Biggar and P. Spyak made these measurements in both the VNIR and SWIR. The second major task was the group's move to a new facility in March. This required that our calibration laboratory and blacklab be disassembled and reassembled in addition to moving offices and other equipment. The third task was the joint vicarious calibration that took place the latter half of June. This campaign included two weeks of laboratory measurements by the RSG and nine days in the field. Other work during the past six months consisted of Science Team support activities including the attendance at meetings related to MODIS and ASTER. In addition, K. Scott continued work on the cross-calibration software package by developing a graphical interface to 6S, an uncertainty analysis code, and an image registration module. M. Sicard used a trip to Cimel in France to change the Cimel TIR radiometer's field of view and then characterized this new field of view. Z. Rouf and Z. Murshalin processed radiance-based data from last summer's Lunar Lake campaign
Dynamic testing of airplane shock-absorbing struts
Measurement of perpendicular impacts of a landing gear with different shock-absorbing struts against the drum testing stand. Tests were made with pneumatic shock absorbers having various degrees of damping, liquid shock absorbers, steel-spring shock absorbers and rigid struts. Falling tests and rolling tests. Maximum impact and gradual reduction of the impacts in number and time in the falling tests. Maximum impact and number of weaker impacts in rolling tests
Advanced superconducting magnets investigation
Mathematical models for steady state behavior of composite superconductors and experimental verification using magnet coi
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Development of interconnected silicon micro-evaporators for the on-detector electronics cooling of the future ITS detector in the ALICE experiment at LHC
This paper was presented at the 4th Micro and Nano Flows Conference (MNF2014), which was held at University College, London, UK. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute, ASME Press, LCN London Centre for Nanotechnology, UCL University College London, UCL Engineering, the International NanoScience Community, www.nanopaprika.eu.The design of the future High Energy Physics (HEP) particle detectors for the upgrade of the LHC (Large Hadron Collider) experiments at CERN (European Organization for Nuclear Research) is pushing technological frontiers to the limit trying to reach unprecedented accuracy in particles identification and particle production dynamics in ultra-relativistic hadron collisions. The thermal management of the on-detector electronics and the development of low mass integrated cooling systems have become a crucial task in the design of silicon tracking detectors for HEP applications. In this paper, we present a novel concept of low mass interconnected silicon microchannel devices for the future Inner Tracking System of the ALICE (A Large Ion Collider Experiment) detector at LHC. This innovative design achieves the requirements of the detector while minimizing the total material budget
Influencing factors on flow boiling of carbon dioxide in enhanced tubes and comparison with correlations
Carbon dioxide two-phase flow characteristics are different from those of conventional refrigerants, due to the CO2 particular thermodynamic and transport properties obtained by working at high reduced pressures. Moreover, the use of peculiar heat transfer surfaces such as grooves and internal fins are often preferred to enhance the boiling heat transfer performance. This paper collects CO2 flow boiling heat transfer coefficient data from different independent databases available in scientific literature, regarding both smooth and enhanced geometries and a wide range of operative conditions, that are typical of refrigeration systems and heat pumps. The database for enhanced tubes covers internal diameters from 0.8 to 8.92 mm, saturation temperatures from -30 to +20 °C, imposed heat fluxes from 1.67 to 60 kW/m2 and mass velocities from 75 to 800 kg/m2s, collecting more than 800 points. Heat transfer data for smooth and enhanced surfaces under the same conditions are collected, in order to measure the enhancement and to correlate it to the geometry augmentation. The assessment of quoted prediction methods explicitly developed for carbon dioxide is finally carried out, with a proposal for a correction factor
CARMA1 is a novel regulator of T-ALL disease and leukemic cell migration to the CNS
No abstract available
Opportunities to Intercalibrate Radiometric Sensors From International Space Station
Highly accurate measurements of Earth's thermal infrared and reflected solar radiation are required for detecting and predicting long-term climate change. We consider the concept of using the International Space Station to test instruments and techniques that would eventually be used on a dedicated mission such as the Climate Absolute Radiance and Refractivity Observatory. In particular, a quantitative investigation is performed to determine whether it is possible to use measurements obtained with a highly accurate reflected solar radiation spectrometer to calibrate similar, less accurate instruments in other low Earth orbits. Estimates of numbers of samples useful for intercalibration are made with the aid of year-long simulations of orbital motion. We conclude that the International Space Station orbit is ideally suited for the purpose of intercalibration
Equine herpesvirus-2 E10 gene product, but not its cellular homologue, activates NF-kappaB transcription factor and c-Jun N-terminal kinase.
We have previously reported on the death effector domain containing E8 gene product from equine herpesvirus-2, designated FLICE inhibitory protein (v-FLIP), and on its cellular homologue, c-FLIP, which inhibit the activation of caspase-8 by death receptors. Here we report on the structure and function of the E10 gene product of equine herpesvirus-2, designated v-CARMEN, and on its cellular homologue, c-CARMEN, which contain a caspase-recruiting domain (CARD) motif. c-CARMEN is highly homologous to the viral protein in its N-terminal CARD motif but differs in its C-terminal extension. v-CARMEN and c-CARMEN interact directly in a CARD-dependent manner yet reveal different binding specificities toward members of the tumor necrosis factor receptor-associated factor (TRAF) family. v-CARMEN binds to TRAF6 and weakly to TRAF3 and, upon overexpression, potently induces the c-Jun N-terminal kinase (JNK), p38, and nuclear factor (NF)-kappaB transcriptional pathways. c-CARMEN or truncated versions thereof do not appear to induce JNK and NF-kappaB activation by themselves, nor do they affect the JNK and NF-kappaB activating potential of v-CARMEN. Thus, in contrast to the cellular homologue, v-CARMEN may have additional properties in its unique C terminus that allow for an autonomous activator effect on NF-kappaB and JNK. Through activation of NF-kappaB, v-CARMEN may regulate the expression of the cellular and viral genes important for viral replication
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