Water quality parameters associated with prevalence of Legionella in hot spring facility water bodies

Some species of Legionella are recognized as opportunistic potential human pathogens, such as Legionella pneumophila, which causes legionnaires disease. Indeed, outbreaks of legionellosis are frequently reported in areas in which the organism has been spread via aerosols from contaminated institutional water systems. Contamination in hot tubs, spas and public baths are also possible. As a result, in this study, we investigated the distribution of Legionella at six hot spring recreation areas throughout Taiwan. Legionella were detected in all six hot spring recreation areas, as well as in 20 of the 72 samples that were collected (27.8%). Seven species of Legionella identified from samples by the direct DNA extraction method were unidentified Legionella spp., Legionella anisa, L. pneumophila, Legionella erythra, Legionella lytica, Legionella gresilensis and Legionella rubrilucen. Three species of Legionella identified in the samples using the culture method were L. pneumophila, unidentified Legionella spp. and L. erythra. Legionella species were found in water with temperatures ranging from 22.7 °C to 48.6 °C. The optimal pH appeared to range from 5.0 to 8.0. Taken together, the results of this survey confirmed the ubiquity of Legionella in Taiwan spring recreational areas. Therefore, a long-term investigation of the health of workers at hot spring recreational areas and the occurrence of Legionella in hot spring recreational areas throughout Taiwan are needed.     

当建筑与时间做朋友:近二十年的台湾在地建筑论述

现代建筑响应工业时代对速度与效率的要求,与此无关的时间向度则被排挤掉,如何找回时间的真实原貌,应是跨越现代建筑的核心挑战.对当代台湾正处在从“发展中”向“已发展”状态挺进的阶段来看,“建筑如何具有填满时间的能力”并非急迫要响应的问题,如何面对社会转型所引来的“创生性”1)挑战才是该被关注的议题.黄声远,谢英俊、邱文杰、廖伟立等台湾当代建筑师,选择与时间为友的态度,关注“时间生成”的向度,他们前进到边缘地区或都市灰色地带,各以不同的“时间友善”的策略发展他们的建筑,并建构出具有多面向公共性的“时间境象”.     

Metaheuristics for scheduling a no-wait flowshop manufacturing cell with sequence-dependent family setups

This paper examines the no-wait flowshop manufacturing cell scheduling problem (FMCSP) with sequence-dependent family setup times. To the best of our knowledge, the present study is among the first to investigate FMSCPs with no-wait consideration, though it is a necessary production constraint in many real-world applications. In view of the strongly NP-hard nature of this problem, three metaheuristic-based algorithms were proposed and empirically evaluated for effectively finding optimal schedules. The experimental results demonstrate that the proposed algorithms are effective and efficient at finding good quality solutions for the FMCSP with makespan criterion.     

Interfacial Reactions in Sn/Fe-xNi Couples

The interfacial reactions between Sn and several Fe-xNi alloys were investigated in this study. Two different FeSn₂ phase types formed at the Sn/Fe-40.8 at.%Ni (Sn/alloy 42) interface. When the Ni content of the Fe-Ni alloy was less than 80 at.%, only the FeSn₂ phase with layer structure could be formed at the interface. When the Ni content was increased to 80 at.% to 90 at.%, both FeSn₂ and Ni₃Sn₄ phases formed in the Sn/Fe-xNi couples. When the Ni content was larger than 95 at.%, only the Ni₃Sn₄ phase was formed at the interface. A fast reaction rate and the thickest intermetallic compound (IMC) layer could be observed in the Sn/Fe-90 at.%Ni couple. The reaction paths of each reaction couple at 270°C were as follows: L/FeSn₂/Fe-40.8 at.%Ni (alloy 42), L/FeSn₂/Ni₃Sn₄/Fe-80 at.% Ni, and L/Ni₃Sn₄/Fe-95 at.%Ni, respectively.     

The relaxation phenomena of positive charges in thin gate oxideduring Fowler-Nordheim tunneling stress

In this study, new relaxation phenomena of positive charges in gate oxide with Fowler-Nordheim (FN) constant current injections have been investigated and characterized. It was found that the magnitudes of applied gate voltage shifts (ΔV_FN) during FN injections, after positive charges relaxed or discharged, have a logarithmic dependence with the relaxation time for both injection polarities. The results can derive the relationship of transient discharging currents, that flow through the oxides after removal of the stress voltage, with the relaxation time. We have shown that the current has a 1/f dependence for both injection polarities which can be also derived from the tunneling front model. The effects of oxide fields (lower than the necessary voltage for FN tunneling) and wafer temperatures (373 and 423 K) for the relaxation of positive charges are also studied     

Design Considerations Between Color Gamut and Brightness for Multi-Primary Color Displays

Color displays show a vivid colorful image by combination of three or above primary colors on every individual pixel. Brightness of color displays, however, strongly restricts the color gamut of displays. From the color mixing theory, the area of color gamut on the color coordination would shrink smaller when brightness grows up. At the maximal brightness, displays can show one system white point only. The difficulties how to obtain the maximal brightness under an assigned color point or color gamut have been a key issue for display manufacturers. The paper proposes a theory to analyze the relation between brightness and color gamut based on the multi-primary color display. Simulations estimate the boundary of color gamut of multi-primary color displays under required brightness which had been proved by experimental results of tri-primary color display. The theory can be applied on the color temperature (CT) design which experimental results show the fact that a display apparatus with higher color temperature could sacrifice brightness less compared to one with lower color temperature when color temperature of the display image needs to change. The theory provides a design guideline for optimization between color gamut, color temperature and brightness on multi-primary color displays     

Interface characteristics of selective tungsten on silicon using anew pretreatment technology for ULSI application

The characteristics of selective tungsten film on silicon strongly depend on the surface properties of the underlying substrate. In this work, a new pretreatment process prior to selective tungsten film deposition has been developed. A CF₄/O₂ mixed plasma modification procedure and a subsequent O₂ plasma ashing step combine to achieve efficient surface precleaning. The damage and contamination induced by reactive ion etching (RIE) are thus eliminated. Concurrently, a subsequent anhydrous HF cleaning was used to remove the native oxide on silicon as well as to obtain a fluorine-passivated silicon surface which can avoid reoxidation during the transport of wafers. This new pretreatment technology produces tungsten films that retain superior physical properties within the aspects of deposition rate, film morphology, and selectivity. Also, excellent interface characteristics with low silicon consumption, low contact resistance, low contact leakage current, and fewer impurities of fluorine, oxygen, and carbon within the interfacial region are obtained     

Scheduling multistage hybrid flowshops with multiprocessor tasks by an effective heuristic

This study considers the scheduling problem of multistage hybrid flowshops with multiprocessor tasks, which is a core topic for numerous industrial applications. An effective and efficient heuristic, namely the heuristic of multistage hybrid flowshops (HMHF) is proposed to solve this problem. To verify the developed heuristic, computational experiments are conducted on a well-known benchmark problem set. The results are compared with 10 constructive heuristics and a tabu search (TS) based meta-heuristic from the relevant literature. These computational results show that the proposed HMHF heuristic is highly effective when compared to these algorithms for this problem on the same benchmark instances.     

Part-machine cell formation in group technology using a simulated annealing-based meta-heuristic

The part-machine cell formation problem (PMCFP) is a crucial step in the design of a cellular manufacturing system and has received considerable research attention over the last five decades. This study proposes a simulated annealing-based meta-heuristic for solving the PMCFP. The effectiveness of the proposed approach is compared to conventional algorithms across a set of PMCFPs available in the literature. Computational results using four types of performance measures show that the proposed simulated annealing-based meta-heuristic is highly effective by comparison with conventional algorithms for PMCFPs on the same test problems.