294 research outputs found
Penentuan Konsep Perancangan Alat Pengering Simplisia Jahe Menggunakan Sumber Panas Sinar Matahari Dengan Backup Panas Kompor Biomassa
The ginger drying process used by Biofarmaka farmers of Karanganyar to produce simplisia, used heat source from solar energy of the sunlight. Sunlight is a free source of energy that can be obtained in the universe but can not be controlled. Production of simplisia can be stopped or obstructed if there is no sunlight that gives solar energy for the drying process (cloudy or rainy). This obstacle of production process of simplisia becomes an important matter considering the low durability of fresh ingredients (ginger). This requires the presence of an additional source of heat energy which is cheap and can be controlled to produce simplisia if the heat source from solar energy of the sunlight can not be used. This study aims to construct concept of design solar dryer with a biomass stove for heat backup to produce ginger simplisia. The step of design are identification of user requirements, construction of product specifications, product concept development, and product concept selection. This study resulted in 36 product concept of the ginger solar dryer
Characterization of Fluctuations of Impedance and Scattering Matrices in Wave Chaotic Scattering
In wave chaotic scattering, statistical fluctuations of the scattering matrix
and the impedance matrix depend both on universal properties and on
nonuniversal details of how the scatterer is coupled to external channels. This
paper considers the impedance and scattering variance ratios, and
, where ,
, and denotes
variance. is shown to be a universal function of distributed losses
within the scatterer. That is, is independent of nonuniversal coupling
details. This contrasts with for which universality applies only in the
large loss limit. Explicit results are given for for time reversal
symmetric and broken time reversal symmetric systems. Experimental tests of the
theory are presented using data taken from scattering measurements on a chaotic
microwave cavity.Comment: 6 pages, 5 figures, updated with referees' comment
Measuring the Lyapunov exponent using quantum mechanics
We study the time evolution of two wave packets prepared at the same initial
state, but evolving under slightly different Hamiltonians. For chaotic systems,
we determine the circumstances that lead to an exponential decay with time of
the wave packet overlap function. We show that for sufficiently weak
perturbations, the exponential decay follows a Fermi golden rule, while by
making the difference between the two Hamiltonians larger, the characteristic
exponential decay time becomes the Lyapunov exponent of the classical system.
We illustrate our theoretical findings by investigating numerically the overlap
decay function of a two-dimensional dynamical system.Comment: 9 pages, 6 figure
Gain Components in Autler-Townes Doublet from Quantum Interferences in Decay Channels
We consider non-degenerate pump-probe spectroscopy of V-systems under
conditions such that interference among decay channels is important. We
demonstrate how this interference can result in new gain features instead of
the usual absorption features. We relate this gain to the existence of a new
vacuum induced quasi-trapped-state. We further show how this also results in
large refractive index with low absorption.Comment: Total 8 pages, 6 figures, submitted to Physical Review
Strain-induced partially flat band, helical snake states, and interface superconductivity in topological crystalline insulators
Topological crystalline insulators in IV-VI compounds host novel topological
surface states consisting of multi-valley massless Dirac fermions at low
energy. Here we show that strain generically acts as an effective gauge field
on these Dirac fermions and creates pseudo-Landau orbitals without breaking
time-reversal symmetry. We predict the realization of this phenomenon in IV-VI
semiconductor heterostructures, due to a naturally occurring misfit dislocation
array at the interface that produces a periodically varying strain field.
Remarkably, the zero-energy Landau orbitals form a flat band in the vicinity of
the Dirac point, and coexist with a network of snake states at higher energy.
We propose that the high density of states of this flat band gives rise to
interface superconductivity observed in IV-VI semiconductor multilayers at
unusually high temperatures, with non-BCS behavior. Our work demonstrates a new
route to altering macroscopic electronic properties to achieve a partially flat
band, and paves the way for realizing novel correlated states of matter.Comment: Accepted by Nature Physic
Circulating Cell-Free DNA in Dogs with Mammary Tumors: Short and Long Fragments and Integrity Index
Circulating cell-free DNA (cfDNA) has been considered an interesting diagnostic/prognostic plasma biomarker in tumor-bearing subjects. In cancer patients, cfDNA can hypothetically derive from tumor necrosis/apoptosis, lysed circulating cells, and some yet unrevealed mechanisms of active release. This study aimed to preliminarily analyze cfDNA in dogs with canine mammary tumors (CMTs). Forty-four neoplastic, 17 non-neoplastic disease-bearing, and 15 healthy dogs were recruited. Necrosis and apoptosis were also assessed as potential source of cfDNA on 78 CMTs diagnosed from the 44 dogs. The cfDNA fragments and integrity index significantly differentiated neoplastic versus non-neoplastic dogs (P<0.05), and allowed the distinction between benign and malignant lesions (P<0.05). Even if without statistical significance, the amount of cfDNA was also affected by tumor necrosis and correlated with tumor size and apoptotic markers expression. A significant (P<0.01) increase of Bcl-2 in malignant tumors was observed, and in metastatic CMTs the evasion of apoptosis was also suggested. This study, therefore, provides evidence that cfDNA could be a diagnostic marker in dogs carrying mammary nodules suggesting that its potential application in early diagnostic procedures should be further investigated
Resonance trapping and saturation of decay widths
Resonance trapping appears in open many-particle quantum systems at high
level density when the coupling to the continuum of decay channels reaches a
critical strength. Here a reorganization of the system takes place and a
separation of different time scales appears. We investigate it under the
influence of additional weakly coupled channels as well as by taking into
account the real part of the coupling term between system and continuum. We
observe a saturation of the mean width of the trapped states. Also the decay
rates saturate as a function of the coupling strength. The mechanism of the
saturation is studied in detail. In any case, the critical region of
reorganization is enlarged. When the transmission coefficients for the
different channels are different, the width distribution is broadened as
compared to a chi_K^2 distribution where K is the number of channels. Resonance
trapping takes place before the broad state overlaps regions beyond the
extension of the spectrum of the closed system.Comment: 18 pages, 8 figures, accepted by Phys. Rev.
Signatures of the correlation hole in total and partial cross sections
In a complex scattering system with few open channels, say a quantum dot with
leads, the correlation properties of the poles of the scattering matrix are
most directly related to the internal dynamics of the system. We may ask how to
extract these properties from an analysis of cross sections. In general this is
very difficult, if we leave the domain of isolated resonances. We propose to
consider the cross correlation function of two different elastic or total cross
sections. For these we can show numerically and to some extent also
analytically a significant dependence on the correlations between the
scattering poles. The difference between uncorrelated and strongly correlated
poles is clearly visible, even for strongly overlapping resonances.Comment: 25 pages, 13 Postscript figures, typos corrected and references adde
Tight-binding study of interface states in semiconductor heterojunctions
Localized interface states in abrupt semiconductor heterojunctions are
studied within a tight-binding model. The intention is to provide a microscopic
foundation for the results of similar studies which were based upon the
two-band model within the envelope function approximation. In a two-dimensional
description, the tight-binding Hamiltonian is constructed such that the
Dirac-like bulk spectrum of the two-band model is recovered in the continuum
limit. Localized states in heterojunctions are shown to occur under conditions
equivalent to those of the two-band model. In particular, shallow interface
states are identified in non-inverted junctions with intersecting bulk
dispersion curves. As a specific example, the GaSb-AlSb heterojunction is
considered. The matching conditions of the envelope function approximation are
analyzed within the tight-binding description.Comment: RevTeX, 11 pages, 3 figures, to appear in Phys. Rev.
Using clustering algorithms to examine the association between working memory training trajectories and therapeutic outcomes among psychiatric and healthy populations
Working memory (WM) training has gained interest due to its potential to enhance cognitive functioning and reduce symptoms of mental disorders. Nevertheless, inconsistent results suggest that individual differences may have an impact on training efficacy. This study examined whether individual differences in training performance can predict therapeutic outcomes of WM training, measured as changes in anxiety and depression symptoms in sub-clinical and healthy populations. The study also investigated the association between cognitive abilities at baseline and different training improvement trajectories. Ninety-six participants (50 females, mean age = 27.67, SD = 8.84) were trained using the same WM training task (duration ranged between 7 to 15 sessions). An algorithm was then used to cluster them based on their learning trajectories. We found three main WM training trajectories, which in turn were related to changes in anxiety symptoms following the training. Additionally, executive function abilities at baseline predicted training trajectories. These findings highlight the potential for using clustering algorithms to reveal the benefits of cognitive training to alleviate maladaptive psychological symptoms
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