284 research outputs found
Analysis and design of a 1 kW Class-GD ultrasonic generator
Word processed copy.Includes bibliographical references (leaves 66-70)
Hot water usage profiling to improve geyser efficiency
This paper presents an intelligent hot water cylinder (HWC) (referred to as geyser) usage profiling system to provide peak demand side management and improve HWC efficiency in a typical household. The study highlights current control topologies used to improve geyser efficiency, as well as the design of the final geyser controller. The system consists of a PIC microcontroller used to determine individually based hot water usage profiles of the user. The controller then regulates the temperature of the geyser according to the demand profile developed. From the results it is apparent that by controlling the geyser temperature and thereby heat loss, savings can be made
Mitigating interference from switch-mode power supplies in sampling receivers
This paper presents the research and development of techniques to mitigate interference from switch-mode power supplies (SMPS) in sampling receivers and also more specifically for FMCW radar receiver applications. During the system testing phase of an FMCW Radar at Reutech Radar Systems (RRS), it was found that a large false target was emerging on the Range-Doppler Map (RDM). It was concluded that the problem was originating from interference caused by the SMPS, which supplies DC power to the radar receiver subsystem. This created the need for a new DC power supply, which is able to minimize the interference itself, and mitigate the effects of the interference caused by the switching of the power supply. The study was divided four main sections, namely, research, simulation, design and evaluation. The research involved obtaining background information on sampling receivers, sampling theory, Range-Doppler Processing, SMPS’s, their effects and mitigation thereof. In the simulation phase, the research was utilised to simulate the various interference mitigation techniques. A power supply PCB was designed in the design phase to practically illustrate the techniques being utilised. Lastly, during evaluation, this PCB was evaluated against the criteria set out in the research phase. The results demonstrated that the techniques of synchronising the PWM clock to the Sampling frequency and Sweep Repetition Frequency yielded a significant reduction in the SMPS noise on the RDM. This technique may also be applied in other electronic sampling systems which perform digitisation of the input data, such as Analog to Digital Converters etc
Experimental delayed-choice entanglement swapping
Motivated by the question, which kind of physical interactions and processes
are needed for the production of quantum entanglement, Peres has put forward
the radical idea of delayed-choice entanglement swapping. There, entanglement
can be "produced a posteriori, after the entangled particles have been measured
and may no longer exist". In this work we report the first realization of
Peres' gedanken experiment. Using four photons, we can actively delay the
choice of measurement-implemented via a high-speed tunable bipartite state
analyzer and a quantum random number generator-on two of the photons into the
time-like future of the registration of the other two photons. This effectively
projects the two already registered photons onto one definite of two mutually
exclusive quantum states in which either the photons are entangled (quantum
correlations) or separable (classical correlations). This can also be viewed as
"quantum steering into the past"
Absolute configuration of (+)-α-dihydrotetrabenazine, an active metabolite of tetrabenazine
Chiral column liquid chromatography and enantiospecific enzymatic hydrolysis were utilized to separate the enantiomers of α- and Β-dihydrotetrabenazine and α-9-O-desmethyldihydrotetrabenazine, three benzo[a]quinolizines derived from the amine-depleting drug tetrabenazine. An X-ray crystal structure analysis of (−)-α-9-O-desmethyldihydrotetrabenazine gave an absolute structure of that compound as the 2 S , 3 S , 11b S isomer. Therefore, (−)-α-dihydrotetrabenazine also has the 2 S , 3 S , 11b S absolute configuration. (+)-α-Dihydrotetrabenazine, the single biologically active isomer from the metabolic reduction of tetrabenazine, thus has the absolute configuration of 2 R , 3 R , 11b R . For further in vitro and in vivo studies of the vesicular monoamine transporter, it is now possible to use the single enantiomer of radiolabeled α-dihydrotetrabenazine. Chirality 9:59–62, 1997. © 1997 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/38533/1/11_ftp.pd
Testing foundations of quantum mechanics with photons
The foundational ideas of quantum mechanics continue to give rise to
counterintuitive theories and physical effects that are in conflict with a
classical description of Nature. Experiments with light at the single photon
level have historically been at the forefront of tests of fundamental quantum
theory and new developments in photonics engineering continue to enable new
experiments. Here we review recent photonic experiments to test two
foundational themes in quantum mechanics: wave-particle duality, central to
recent complementarity and delayed-choice experiments; and Bell nonlocality
where recent theoretical and technological advances have allowed all
controversial loopholes to be separately addressed in different photonics
experiments.Comment: 10 pages, 5 figures, published as a Nature Physics Insight review
articl
The Locality Problem in Quantum Measurements
The locality problem of quantum measurements is considered in the framework
of the algebraic approach. It is shown that contrary to the currently
widespread opinion one can reconcile the mathematical formalism of the quantum
theory with the assumption of the existence of a local physical reality
determining the results of local measurements. The key quantum experiments:
double-slit experiment on electron scattering, Wheeler's delayed-choice
experiment, the Einstein-Podolsky-Rosen paradox, and quantum teleportation are
discussed from the locality-problem point of view. A clear physical
interpretation for these experiments, which does not contradict the classical
ideas, is given.Comment: Latex, 40 pages, 7 figure
Transcriptome annotation using tandem SAGE tags
Analysis of several million expressed gene signatures (tags) revealed an increasing number of different sequences, largely exceeding that of annotated genes in mammalian genomes. Serial analysis of gene expression (SAGE) can reveal new Poly(A) RNAs transcribed from previously unrecognized chromosomal regions. However, conventional SAGE tags are too short to identify unambiguously unique sites in large genomes. Here, we design a novel strategy with tags anchored on two different restrictions sites of cDNAs. New transcripts are then tentatively defined by the two SAGE tags in tandem and by the spanning sequence read on the genome between these tagged sites. Having developed a new algorithm to locate these tag-delimited genomic sequences (TDGS), we first validated its capacity to recognize known genes and its ability to reveal new transcripts with two SAGE libraries built in parallel from a single RNA sample. Our algorithm proves fast enough to experiment this strategy at a large scale. We then collected and processed the complete sets of human SAGE tags to predict yet unknown transcripts. A cross-validation with tiling arrays data shows that 47% of these TDGS overlap transcriptional active regions. Our method provides a new and complementary approach for complex transcriptome annotation
On the limits of quantum theory: contextuality and the quantum-classical cut
This paper is based on four assumptions: 1. Physical reality is made of
linearly behaving components combined in non-linear ways. 2. Higher level
behaviour emerges from this lower level structure. 3. The way the lower level
elements behaves depends on the context in which they are imbedded. 4. Quantum
theory applies to the lower level entities. An implication is that higher level
effective laws, based in the outcomes of non-linear combinations of lower level
linear interactions, will generically not be unitary; hence the applicability
of quantum theory at higher levels is strictly limited. This leads to the view
that both state vector preparation and the quantum measurement process are
crucially based in top-down causal effects, and helps provide criteria for the
Heisenberg cut that challenge some views on Schroedinger's cat.Comment: 65 pages, 10 diagrams. Revised in response to referee comments; to
appear in Annals of Physic
Diseño de una lista de chequeo para la orientación psicojurídica en víctimas de asalto sexual (L.O.P.V.A.S)
Curso Especial de Interés : Victimología y CriminologíaLa siguiente propuesta, contiene la información necesaria en el diseño un instrumento que permita determinar y analizar los factores que están involucrados en este tipo de violencia. El objetivo de esta investigación es diseñar una lista de chequeo en atención Psicojurídica para la orientación en la denuncia en víctimas de abuso sexual a partir del reconocimiento de patrones conductuales y el modus operandi del agresor. Esta lista de chequeo nos permite la orientación a víctimas de asalto sexual para el establecimiento de la denuncia, esta guía brinda a los funcionarios públicos la oportunidad de reconocer las necesidades de la víctima de asalto sexual y a partir de la información lograr tipificar la conducta de asalto sexual y a partir de ello generar estrategias de planificación en prevención y promoción de violencia sexual bajo los criterios de las políticas públicas.1. Resumen
2. Justificación
3. Marco Teórico
4. Marco Legal
5. Marco Ético
6. Objetivos
7. Estudio de Mercadeo
8. Presentación del Producto
9. Variables Psicológicas que lo componen
10. Clientes
11. Competencia
12. Resultados
13. Conclusiones
14. ReferenciasPregradoPsicólog
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