Singlet-triplet transitions in highly correlated nanowire quantum dots

We consider a quantum dot embedded in a three-dimensional nanowire with tunable aspect ratio a. A configuration interaction theory is developed to calculate the energy spectra of the finite 1D quantum dot systems charged with two electrons in the presence of magnetic fields B along the wire axis. Fruitful singlet-triplet transition behaviors are revealed and explained in terms of the competing exchange interaction, correlation interaction, and spin Zeeman energy. In the high aspect ratio regime, the singlet-triplet transitions are shown designable by tuning the parameters a and B. The transitions also manifest the highly correlated nature of long nanowire quantum dots.Comment: 4 pages, 4 figure

Performance Analysis of Dual Unipolar/Bipolar Spectral Code in Optical CDMA Systems

This study analyzes and calculates dual unipolar and bipolar coded configurations of spectral-amplitude-coding opticalcode division multiple access (SAC-OCDMA) systems by using simulation methods. The important feature of theSAC-OCDMA systems is that multiple access interference (MAI) can be eliminated by code sequences of a fixed inphasecross-correlation value. This property can be effectively canceled multiple access interference by using balancedetection schemes. This study uses Walsh-Hadamard codes as signature codes for the unipolar and bipolar schemes.The coder and decoder structures are based on optical filters of fiber Bragg gratings (FBGs). The simulation results ofunipolar/bipolar coding structures are first presented by commercial simulation obtained using OptiSystem software.The simulation results show that the bit error rate (BER) through use of the bipolar coding method is superior to theunipolar scheme, especially when the received effect power is large. When the system needs good performance totransmit multimedia data, we can use bipolar scheme in the network. If the users only transmit voice data, the unipolarmethod can be employed. The eye diagram also shows that the bipolar encoding structure exhibits a wider openingthan the unipolar encoding structure. The flexible implementation of codewords assigns and integratable hardwaredesigns for the scheme with FBGs to realize dual coding OCDMA system is proposed

Experimental research on night heat loss and dust effect of distillation-solar chimney power plant

To more comprehensively grasp the operating characteristics of the solar chimney power plants combined with distillation and provide a valuable reference for the design and operation of the power plants, a comparative test platform was built in this paper, which adopted manual covering of insulation layer and dust, and explored for the first time the impact of the insulation layer and dust accumulation on the operational characteristics of power plants. The results show that the insulation layer can increase the temperature rise of the airflow at night by a maximum of 2.1 ◦C, which is 25.9 %; but at the same time, it will reduce the temperature difference between the seawater and the solar still cover, resulting in a decrease of more than 7 % in daily water yield. Therefore, if the power plant pursues water production, it is not necessary to install insulation layers. Dust accumulation will affect the heat collection and storage performance of the system, reduce the power output, and shorten the effective power generation time; at the same time, lowering the seawater temperature will also reduce the water yield of the system by more than 10 %, so the power plant must regularly clean the collector roof

A Performance Evaluation of Introducing Balanced Scorecard to High-tech Related Industries in Taiwan

Balanced Scorecard (BSC) has become the most desirable performance evaluation tool for industries in Taiwan; however, difficulty or bad performance of system introduction has occurred due to an incomplete understanding of the implementation approaches and correct objectives of the BSC system, causing the risk of cost loss. Two domestic high-tech companies in the high-tech related industry were served as the object of study in this research. The contents of four perspectives of the BSC were converted to twenty key performance evaluation indicators in terms of modern business administration as the variables in the research. Based on the DMAIC model, the importance and satisfaction of BSC implementation factors in high-tech related industry are defined first. The performance indices of satisfaction and importance of implementing BSC are standardized by fuzzy methods for evaluation and a performance matrix with the target line and upper and lower performance control lines are established. Management can analyze the performance level and compare the performance indices and matrixes of two companies after introducing BSC according to the coordinates of satisfaction and importance of implementation factors in the matrixes. These two-dimension matrices will then be converted to one-dimension coordinates for cross performance matrices of four quadrants. Next, performance improvement strategies will be devised in accordance with the aspects of the theory of constraints. After carrying out improvement strategies, the cross performance matrix will be constructed to verify the effect and ascertain the factors of bad performance. In this way, improvement strategies can be re-devised and the most appropriate distribution of resources will be made to sustain the optimum state of ability and cost during the process of introducing the BSC system. Requirements for a short period of time and low cost to evaluate the performance of BSC introduction can be met via this simple and convenient evaluation model presented in this research. Resources will be invested to enhance satisfaction for the implementation factors of high importance and low satisfaction. Likewise, resources will be adjusted to reduce the cost of system introduction for the implementation factors of low importance and high satisfaction. As a result, the time efficiency of introducing the BSC system will be promoted effectively

PHP61 The Financial Impacts of Pharmacist Intervention in Inpatient Department of a Local Hospital in Taiwan

Morphometric analysis of S. mortenseni. (DOC 44 kb

Finite Element Analysis of the Displacement Adjustment Scheme for Column Bases of a 10000 m3 Spherical Tank During Whole-body Heat Treatment

AbstractThe stress of spherical tank and displacement of column bases were calculated by finite element method, considering the uneven gravity loads on support columns which was caused by manufacturing and setting errors. The preliminary displacement adjustment scheme for column bases was made, according to the safety range of column bases displacement which was determined by the maximum stress restricted by allowable stress at the set heat treatment temperatures. The final scheme was made after checking the preliminary scheme. The method of making adjustment scheme of column bases for a 10000m3 spherical tank during the whole-body heat treatment may provide a reference for other large spherical tank

Interference - minimized multipath routing with congestion control in wireless sensor network for multimedia streaming

Master'sMASTER OF ENGINEERIN

Microstructural control of TiC/a-C nanocomposite coatings with pulsed magnetron sputtering

In this paper, we report some striking results on the microstructural control of TiC/a-C nanocomposite coatings with pulsed direct current (DC) magnetron sputtering. The interface morphology and microstructure evolution as a function of pulse frequency and duty cycle were scrutinized using atomic force microscopy, scanning electron microscopy and high-resolution transmission electron microscopy techniques. It is shown that, with increasing pulse frequency, the nanocomposite coatings exhibit evolutions in morphology of the growing interface from rough to smooth and in the microstructure from strongly columnar to fully columnar-free. In addition, the smoothly growing interface favors the formation of a tailor-made multilayered nanocomposite structure. The fundamental mechanisms are analyzed with the assistance of plasma diagnostic experiments. Ion mass/energy spectrometry measurements reveal that, depending on the frequency and duty cycle of DC pulses, pulsing of the magnetrons can control the flux and energy distribution of Ar+ ions over a very broad range for concurrent impingement on the growing interface of deposited coatings, in comparison with DC sputtering. The significantly enhanced energy flux density is thought to be responsible for the "adatom transfer" in interface smoothening and thus the restraint of columnar growth. (C) 2007 Acta Materialia, Inc. Published by Elsevier Ltd. All rights reserved.</p

Cancer-testis gene expression is associated with the methylenetetrahydrofolate reductase 677 C>T polymorphism in non-small cell lung carcinoma

Background: Tumor-specific, coordinate expression of cancer-testis (CT) genes, mapping to the X chromosome, is observed in more than 60% of non-small cell lung cancer (NSCLC) patients. Although CT gene expression has been unequivocally related to DNA demethylation of promoter regions, the underlying mechanism leading to loss of promoter methylation remains elusive. Polymorphisms of enzymes within the 1-carbon pathway have been shown to affect S-adenosyl methionine (SAM) production, which is the sole methyl donor in the cell. Allelic variants of several enzymes within this pathway have been associated with altered SAM levels either directly, or indirectly as reflected by altered levels of SAH and Homocysteine levels, and altered levels of DNA methylation. We, therefore, asked whether the five most commonly occurring polymorphisms in four of the enzymes in the 1-carbon pathway associated with CT gene expression status in patients with NSCLC.Methods: Fifty patients among a cohort of 763 with NSCLC were selected based on CT gene expression status and typed for five polymorphisms in four genes known to affect SAM generation by allele specific q-PCR and RFLP.Results: We identified a significant association between CT gene expression and the MTHFR 677 CC genotype, as well as the C allele of the SNP, in this cohort of patients. Multivariate analysis revealed that the genotype and allele strongly associate with CT gene expression, independent of potential confounders.Conclusions: Although CT gene expression is associated with DNA demethylation, in NSCLC, our data suggests this is unlikely to be the result of decreased MTHFR function. © 2013 Senses et al.; licensee BioMed Central Ltd

Performance evaluation and optimal design of supermarket refrigeration systems with supermarket model "SuperSim", Part II: Model applications

This is the post-print version of the final paper published in International Journal of Refrigeration. The published article is available from the link below. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. Copyright @ 2010 Elsevier B.V.As described in Part I, the supermarket simulation software “SuperSim” with its integrated refrigeration, building and HVAC system models, can be used to evaluate, compare and optimize alternative supermarket refrigeration systems. In Part II the model was used to evaluate and compare the performance of a CO2 booster refrigeration system with that of a conventional R404A multiplex system in a supermarket application. Floating head pressure control was implemented for both systems when they were in subcritical cycles. For the CO2 system, when the system was in transcritical cycle due to higher ambient air temperature, the head pressure was optimized through extensive thermodynamic cycle analysis as a function of ambient air temperature. The performance of the CO2 booster system in the supermarket was then simulated during a one year period and compared with that of the R404A system. As a result, the system performance will benefit from a lower ambient temperature and a sizeable heat recovery for the CO2 system