6,693 research outputs found
High field CdS detector for infrared radiation
New and highly sensitive method of detecting infrared irradiation makes possible solid state infrared detector which is more sensitive near room temperature than usual photoconductive low band gap semiconductor devices. Reconfiguration of high field domains in cadmium sulphide crystals provides basis for discovery
High field CdS detector for infrared radiation
An infrared radiation detector including a cadmium sulfide platelet having a cathode formed on one of its ends and an anode formed on its other end is presented. The platelet is suitably doped such that stationary high-field domains are formed adjacent the cathode when based in the negative differential conductivity region. A negative potential is applied to the cathode such that a high-field domain is formed adjacent to the cathode. A potential measuring probe is located between the cathode and the anode at the edge of the high-field domain and means are provided for measuring the potential at the probe whereby this measurement is indicative of the infrared radiation striking the platelet
Dynamics of Coupling Functions in Globally Coupled Maps: Size, Periodicity and Stability of Clusters
It is shown how different globally coupled map systems can be analyzed under
a common framework by focusing on the dynamics of their respective global
coupling functions. We investigate how the functional form of the coupling
determines the formation of clusters in a globally coupled map system and the
resulting periodicity of the global interaction. The allowed distributions of
elements among periodic clusters is also found to depend on the functional form
of the coupling. Through the analogy between globally coupled maps and a single
driven map, the clustering behavior of the former systems can be characterized.
By using this analogy, the dynamics of periodic clusters in systems displaying
a constant global coupling are predicted; and for a particular family of
coupling functions, it is shown that the stability condition of these clustered
states can straightforwardly be derived.Comment: 12 pp, 5 figs, to appear in PR
Decoherence-based exploration of d-dimensional one-way quantum computation
We study the effects of amplitude and phase damping decoherence in
d-dimensional one-way quantum computation (QC). Our investigation shows how
information transfer and entangling gate simulations are affected for d>=2. To
understand motivations for extending the one-way model to higher dimensions, we
describe how d-dimensional qudit cluster states deteriorate under environmental
noise. In order to protect quantum information from the environment we consider
the encoding of logical qubits into physical qudits and compare entangled pairs
of linear qubit-cluster states with single qudit clusters of equal length and
total dimension. Our study shows a significant reduction in the performance of
one-way QC for d>2 in the presence of Markovian type decoherence models.Comment: 8 pages, 11 figures, RevTeX
THEORY OF PHASE-LOCKING IN SMALL JOSEPHSON JUNCTION CELLS
Within the RSJ model, we performed a theoretical analysis of phase-locking in
elementary strongly coupled Josephson junction cells. For this purpose, we
developed a systematic method allowing the investigation of phase-locking in
cells with small but non-vanishing loop inductance.The voltages across the
junctions are found to be locked with very small phase difference for almost
all values of external flux. However, the general behavior of phase-locking is
found to be just contrary to that according to weak coupling. In case of strong
coupling there is nearly no influence of external magnetic flux on the phases,
but the locking-frequency becomes flux-dependent. The influence of parameter
splitting is considered as well as the effect of small capacitive shunting of
the junctions. Strongly coupled cells show synchronization even for large
parameter splitting. Finally, a study of the behavior under external microwave
radiation shows that the frequency locking-range becomes strongly
flux-dependent, whereas the locking frequency itself turns out to be
flux-independent.Comment: 26 pages, REVTEX, 9 PS figures appended in uuencoded form at the end,
submitted to Phys. Rev. B
Synchronized dynamic dose reconstruction
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/134978/1/mp8157.pd
Evaluating the sensitivity of hybridization-based epigenotyping using a methyl binding domain protein
Hypermethylation of CpG islands in gene promoter regions has been shown to be a predictive biomarker for certain diseases. Most current methods for methylation profiling are not well-suited for clinical analysis. Here, we report the development of an inexpensive device and an epigenotyping assay with a format conducive to multiplexed analysis.David H. Koch Institute for Integrative Cancer Research at MIT (First-year Graduate Fellowship)National Science Foundation (U.S.). Graduate Research FellowshipBurroughs Wellcome Fund (Career Award at the Scientific Interface)National Institute of Environmental Health Sciences (Grant P30-ES002109)Massachusetts Institute of Technology. James H. Ferry Fund for Innovation in Research Educatio
Efficacies of liposome-encapsulated streptomycin and ciprofloxacin against Mycobacterium avium-M. intracellulare complex infections in human peripheral blood monocyte/macrophages
Current treatments of disseminated infection caused by the Mycobacterium avium-M. intracellulare complex (MAC) are generally ineffective. Liposome- mediated delivery of antibiotics to MAC-infected tissues in vivo can enhance the efficacy of the drugs (N. Duzgunes, V. K. Perumal, L. Kesavalu, J. A. Goldstein, R. J. Debs, and P. R. J. Gangadharam, Antimicrob. Agents Chemother. 32:1404-1411, 1988; N. Duzgunes, D. A. Ashtekar, D. L. Flasher, N. Ghori, R. J. Debs, D. S. Friend, and P. R. J. Gangadharam, J. Infect. Dis. 164:143-151, 1991). We investigated the therapeutic efficacies of liposome- encapsulated streptomycin and ciprofloxacin against growth of the MAC inside human peripheral blood monocyte/macrophages. Treatment was initiated 24 h after infection of macrophages with the MAC and stopped after 20 h, and the cells were incubated for another 7 days. The antimycobacterial activity of streptomycin was enhanced when the drug was delivered to macrophages in liposome-encapsulated form, reducing the CFU about threefold more than the free drug did throughout the concentration range studied (10 to 50 μg/ml). With 50 μg of encapsulated streptomycin per ml, the CFU were reduced to 11% of the initial level of infection. Liposome-encapsulated ciprofloxacin was at least 50 times more effective against the intracellular bacteria than was the free drug: at a concentration of 0.1 μg/ml, liposome-encapsulated ciprofloxacin had greater antimycobacterial activity than the free drug at 5 μg/ml. With liposome-encapsulated ciprofloxacin at 5 μg/ml, the CFU were reduced by more than 1,000-fold at the end of the 7-day incubation period, compared with untreated controls. These results suggest that liposome- encapsulated ciprofloxacin or other fluoroquinolones may be effective against MAC infections in vivo
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