The Linear Boltzmann Equation as the Low Density Limit of a Random Schrodinger Equation

We study the evolution of a quantum particle interacting with a random potential in the low density limit (Boltzmann-Grad). The phase space density of the quantum evolution defined through the Husimi function converges weakly to a linear Boltzmann equation with collision kernel given by the full quantum scattering cross section.Comment: 74 pages, 4 figures, (Final version -- typos corrected

Broadband Tuning (170nm) of InGaAs Quantum Well Lasers

The wavelength tuning properties of strained InGaAs quantum well lasers using an external grating for feedback is reported. Tunable laser oscillation has been observed over a range of 170 nm, between 840 and 1010 nm, under pulsed current excitation. The optimal conditions for broadband tunability for the InGaAs lasers are different from GaAs lasers, which is attributed to a difference in spectral gain curves. Together with an optimised GaAs quantum well laser the entire region between 740 and 1010 nm is spanned

Demonstration of astrocytes in cultured amniotic fluid cells of three cases with neural-tube defect

We have investigated the origin of rapidly adhering (RA) cells in three cases of neural tube defects (two anencephali, one encephalocele). We were able to demonstrate the presence of glial fibrillary acidic (GFA) protein in variable percentages (4–80%) of RA cells cultured for 4–6 days by use of indirect immunofluorescence with GFA antiserum. Cells cultured from amniotic fluids of normal pregnancies and fetal fibroblasts were completely GFA protein negative. GFA protein is well established as a highly specific marker for astrocytes. Demonstration of astrocytes may prove to be a criterion of high diagnostic value for neural tube defects. The percentage of astrocytes decreased with increasing culture time, while the percentage of fibronectin positive cells increased both in amniotic fluid cell cultures from neural tube defects and normal pregnancies

On-board demux/demod

To make satellite channels cost competitive with optical cables, the use of small, inexpensive earth stations with reduced antenna size and high powered amplifier (HPA) power will be needed. This will necessitate the use of high e.i.r.p. and gain-to-noise temperature ratio (G/T) multibeam satellites. For a multibeam satellite, onboard switching is required in order to maintain the needed connectivity between beams. This switching function can be realized by either an receive frequency (RF) or a baseband unit. The baseband switching approach has the additional advantage of decoupling the up-link and down-link, thus enabling rate and format conversion as well as improving the link performance. A baseband switching satellite requires the demultiplexing and demodulation of the up-link carriers before they can be switched to their assigned down-link beams. Principles of operation, design and implementation issues of such an onboard demultiplexer/demodulator (bulk demodulator) that was recently built at COMSAT Labs. are discussed

Sistem Informasi Manajemen Jual-Beli Di Grosir Buah UD. Sumber Buah Berbasis Web (Studi Kasus : Ud. Sumber Buah Pasar Gede Solo)

Now is the era of computerized technology, more and more people computer users who use various applications to facilitate everyday activities they tend chose something instant, secure and efficient. no exception in buying and selling things. Modeled on the management of online advertising buying and selling in 2015 is extremely in the example case of a website visitor enjoy doing "olx.co.id" and "berniaga.com" or still many others are ordinary people too easily open the stall and into admin ad account its own, the average selling advertising on the website was successful in buying and selling activities because greatly facilitate the activities of the community to meet their daily needs. Admin management modeled on the computerization of sales mentioned above, then to data processing facilitate the buying and selling fruit at UD. Sumber Buah Pasar Gede Solo also requires the management of information systems. The case of problems the author designed and built a management information system of buying and selling in the wholesale fruit UD. Sumber Buah web-based PHP programming language created on the computer with the Windows operating system by using the application editor "Notepad ++", the reasons wear Notepad ++ because this application can be downloaded for free and have a rule rules which is easily understood, then use the "Appserv" to cultivate localhost its database with the judgment has the best accuracy compared to database server the other, and has a high capacity to be able to run on multiple operating systems different. Using the "MySql" as database management for MySQL has a command and the rules are relatively simple to use, with the nature of open source and flexible. Keyword: Appserv, MySql, Notepad ++, PH

Challenges of deploying a scalable user generated content platform for young people

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2008.Includes bibliographical references (leaf 39).ScratchR, a user generated content management platform, was developed by the Lifelong Kindergarten group at the MIT Media Lab. ScratchR lets users share projects developed with the Scratch programming language. This thesis involves technical improvements made to ScratchR from August 2007 to August 2008. Improvements include the addition of a comment reply system, the improvement of the gallery system, the addition of AJAX functionality, the creation of administration tools and the addition of a peer review system for comments and tags. These features augment the user experience of the Scratch online community by improving usability and by creating a friendlier online learning environment.by Han Xu.M.Eng