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Technologies, Volume 5, Issue 2 (June 2017)

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Research

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Open AccessArticle Railway Continuous Prestressed Concrete Bridge Design in Ballastless Track Turnout Zones
Technologies 2017, 5(2), 11; doi:10.3390/technologies5020011
Received: 31 December 2016 / Revised: 17 March 2017 / Accepted: 23 March 2017 / Published: 30 March 2017
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Abstract
Laying ballastless track on railway bridges has the advantages of reducing the train noise problem, improving passenger comfort, and reducing track maintenance costs. Therefore, railway bridges with ballastless track have gradually turned into a major trend in railway systems all over the world.
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Laying ballastless track on railway bridges has the advantages of reducing the train noise problem, improving passenger comfort, and reducing track maintenance costs. Therefore, railway bridges with ballastless track have gradually turned into a major trend in railway systems all over the world. In Taiwan, railway bridges with ballastless track have been in use for many years, with ballastless track turnouts also starting to be constructed in recent years. Where railway bridges with ballastless track turnouts are located in urban areas, special consideration must be given to the road crossings and the use of continuous bridges in the turnout zones. Accordingly, there arise a number of difficulties related to the bridge configurations or the continuous length of bridges being excessively long. Often, such situations necessitate the use of extremely large-sized bridge piers in the bridge design, or create the risk of serious damage to the pier structure should insufficient attention be given to any of the factors. This article will take a continuous prestressed concrete bridge as an example. The prestressed concrete bridge must be absolutely continuous, be able to include ballastless track turnout zones, and meet the needs of crossing roads. For this example, the length of the continuous prestressed concrete bridge is over 300 m. This article will also discuss the configuration of a continuous prestressed concrete bridge of railway, and—through the analysis of track–bridge interaction and temperature detection—provides suggestions on the optimal configuration model of the continuous prestressed concrete bridges, which should allow improper configuration and possible structural damage to be avoided. Full article
(This article belongs to the Special Issue Construction Materials Technologies)
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Open AccessArticle Research and Application of a SCADA System for a Microgrid
Technologies 2017, 5(2), 12; doi:10.3390/technologies5020012
Received: 8 February 2017 / Revised: 8 March 2017 / Accepted: 29 March 2017 / Published: 31 March 2017
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Abstract
An effective Supervisory Control and Data Acquisition (SCADA) system can improve the reliability, safety and economic benefits of a microgrid operation. In this research, the lower central controller and upper WEB (World Wide Web) monitoring system are connected by the SCADA system, which
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An effective Supervisory Control and Data Acquisition (SCADA) system can improve the reliability, safety and economic benefits of a microgrid operation. In this research, the lower central controller and upper WEB (World Wide Web) monitoring system are connected by the SCADA system, which is the hub of a microgrid intelligent monitoring platform. This system contains a set of specific functions programmed by Java as a middleware and can provide communication and control functions between the central controller and the upper monitoring system. For the sake of security and stability of the microgrid, the SCADA system realizes business processing on real-time data acquisition and storage, load balancing and resource recovery, concurrent security processing, and control instruction parsing and transmission. All those functions were tested and verified in actual operation. Full article
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Open AccessArticle Moveable Factories for Leapfrog Manufacturing in an Industrial Economy
Technologies 2017, 5(2), 13; doi:10.3390/technologies5020013
Received: 14 March 2017 / Revised: 30 March 2017 / Accepted: 31 March 2017 / Published: 1 April 2017
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Abstract
Moveable factories can enable leapfrogging of fixed industrial factories, and so make immediate contributions to global goals of more resilient sustainable manufacturing. Moveable factories bring into use diverse technological advances that reduce the number, size, and weight of machines needed to carry out
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Moveable factories can enable leapfrogging of fixed industrial factories, and so make immediate contributions to global goals of more resilient sustainable manufacturing. Moveable factories bring into use diverse technological advances that reduce the number, size, and weight of machines needed to carry out manufacturing operations at points of supply and/or demand. However, fixed industrial factories continue to be the principal focus for development and application of new manufacturing technologies. At the same time, fixed industrial factories continue to be seen by policy makers around the world as the default option for developing prosperity: rather than as an old fashioned production paradigm to be leapfrogged over. In this paper, findings are reported from a case study investigating potential for moveable factories to bring leapfrog manufacturing to an industrial economy. This case study comprised literature review, interviews, and theoretical analyses. Study findings indicate that organisations in an industrial economy will consider moveable factories if fixed factories are not feasible, practical, or viable. By contrast, potential for improved efficiency and flexibility may not be sufficient to motivate a shift away from fixed industrial factories. Full article
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Open AccessArticle Proximate Composition, Extraction, and Purification of Theobromine from Cacao Pod Husk (Theobroma Cacao L.)
Technologies 2017, 5(2), 14; doi:10.3390/technologies5020014
Received: 4 March 2017 / Revised: 29 March 2017 / Accepted: 30 March 2017 / Published: 2 April 2017
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Abstract
The aims of this study were to determine the proximate composition of cacao pod husk as well as the optimal conditions for extraction and purification of theobromine from cacao pod husk. The results indicated that cacao pod husk had high contents of moisture
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The aims of this study were to determine the proximate composition of cacao pod husk as well as the optimal conditions for extraction and purification of theobromine from cacao pod husk. The results indicated that cacao pod husk had high contents of moisture and carbohydrate (87.06% and 11.03% by fresh weight, respectively), but low contents of crude protein, crude lipid, and ash (0.31%, 0.12%, and 1.48% by fresh weight, respectively). The optimal conditions for extraction of theobromine from cacao pod husk were of 70% ethanol, with an extraction time of 90 min, and 1 as the number of extractions. A concentration of 10% by volume of 10% lead acetate solution was the best selection for purification of the crude extracts containing theobromine from cacao pod husk. Under these optimal conditions, theobromine content obtained from cacao pod husk was 6.79 mg/100 g dry weight. The finding from this study is a valuable contribution for obtaining theobromine from an abundant, inexpensive, renewable, and sustainable source for potential application in the nutraceutical, medical, and pharmaceutical industries. Full article
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Open AccessArticle Accelerated Detector Response Function in Squeezed Vacuum
Technologies 2017, 5(2), 17; doi:10.3390/technologies5020017
Received: 18 February 2017 / Revised: 12 April 2017 / Accepted: 19 April 2017 / Published: 20 April 2017
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Abstract
Casimir/squeezed vacuum breaks Lorentz symmetry, by allowing light to propagate faster than c. We looked at the possible transformation symmetry group such vacuum could obey. By solving the semi-classical Einstein field equation in squeezed vacuum, we have found that the background geometry
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Casimir/squeezed vacuum breaks Lorentz symmetry, by allowing light to propagate faster than c. We looked at the possible transformation symmetry group such vacuum could obey. By solving the semi-classical Einstein field equation in squeezed vacuum, we have found that the background geometry describes an Anti-deSitter (AdS) geometry. Therefore, the proper transformation symmetry group is the (A)dS group. One can describe quantum field theory in a finite volume as a quantum field theory (QFT) on AdS background, or vice versa. In particular, one might think of QFT vacuum on AdS as a QFT that posses a squeezed vacuum with boundary conditions proportional to R A d S 2 . Applying this correspondence to an accelerating detector-scalar field system, we notice at low acceleration the system is at equilibrium at ground state, however if the detector’s acceleration (a) is greater than a critical acceleration, the system experience a phase transition similar to Hawking-Page Phase transition at the detector gets excited, with equivalent temperature Θ = a 2 - R A d S 2 2 π . Full article
(This article belongs to the Special Issue Quantum Gravity Phenomenology and Experimental Implications)
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Open AccessArticle A Transportable Photovoltaic Power Generation System Utilizing a SiC Inverter and Spherical Si Solar Cells
Technologies 2017, 5(2), 18; doi:10.3390/technologies5020018
Received: 10 March 2017 / Revised: 19 April 2017 / Accepted: 19 April 2017 / Published: 21 April 2017
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Abstract
This paper reports a 100-W class transportable photovoltaic (PV) power generation system built with SiC power devices. Conventionally, studies on SiC power converters have mostly focused on multi-kW applications. In this paper, we have verified the feasibility of the SiC power devices for
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This paper reports a 100-W class transportable photovoltaic (PV) power generation system built with SiC power devices. Conventionally, studies on SiC power converters have mostly focused on multi-kW applications. In this paper, we have verified the feasibility of the SiC power devices for sub-kW PV power generation systems. The developed PV power generation system consisted of a spherical Si solar cell module, a 150-W SiC PV-inverter unit with maximum power point tracking (MPPT) function, and a 12-V Li-ion battery. The total weight of the system was just 4.3 kg. Conversion efficiencies of the MPPT charge controller and the direct current-alternating current converter reached 98.0% and 88.4%, respectively. The developed system exhibited stable output power characteristics, even when the weather conditions were fluctuated. These compactness, high efficiencies, and excellent stability clearly indicated the feasibility of SiC power devices even for sub-kW class PV power generation systems. This kind of system would be available for the applications where compactness and transportability are of tremendous importance. Full article
(This article belongs to the Section Energy and Environmental Technologies)
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Open AccessArticle Measurement of Assistive Technology Outcomes Associated with Computer-Based Writing Interventions for Children and Youth with Disabilities
Technologies 2017, 5(2), 19; doi:10.3390/technologies5020019
Received: 30 January 2017 / Revised: 22 March 2017 / Accepted: 19 April 2017 / Published: 22 April 2017
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Abstract
Young people who have chronic disabilities use computer technologies and receive rehabilitation services to overcome functional limitations associated with writing activities. However, the functional impact of these specialized assistive technologies on the everyday lives of children is not clearly understood; in part due
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Young people who have chronic disabilities use computer technologies and receive rehabilitation services to overcome functional limitations associated with writing activities. However, the functional impact of these specialized assistive technologies on the everyday lives of children is not clearly understood; in part due to the lack of targeted outcome measures. This article describes the development and evaluation of the Family Impact of Assistive Technology Scale for Writing Interventions (FIATS-WI). The FIATS-WI is a multi-dimensional, parent-report questionnaire designed to measure child functioning and outcomes associated with computer-based writing interventions for children and youth aged 5–18 years. Participants included parents of children with writing-related disabilities who completed the questionnaire at home during one of two study phases. In the first phase, 121 eligible parents, out of 364 invited, completed a single administration of the questionnaire. In the second phase, 28 out of 33 eligible parents completed the FIATS-WI twice to assess its stability. Item and subscale correlations informed an item reduction plan, and Cronbach’s alpha and intraclass correlation coefficients provided acceptable estimates for internal consistency and test–retest reliability, respectively. Correlations between FIATS-WI scores and scores from a standardized home participation measure tested its convergent validity. The study provides emerging evidence for the FIATS-WI as a sound measure of computer-based writing technology outcomes for children and youth with disabilities. Full article

Review

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Open AccessReview Overhanging Features and the SLM/DMLS Residual Stresses Problem: Review and Future Research Need
Technologies 2017, 5(2), 15; doi:10.3390/technologies5020015
Received: 24 March 2017 / Revised: 7 April 2017 / Accepted: 10 April 2017 / Published: 12 April 2017
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Abstract
A useful and increasingly common additive manufacturing (AM) process is the selective laser melting (SLM) or direct metal laser sintering (DMLS) process. SLM/DMLS can produce full-density metal parts from difficult materials, but it tends to suffer from severe residual stresses introduced during processing.
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A useful and increasingly common additive manufacturing (AM) process is the selective laser melting (SLM) or direct metal laser sintering (DMLS) process. SLM/DMLS can produce full-density metal parts from difficult materials, but it tends to suffer from severe residual stresses introduced during processing. This limits the usefulness and applicability of the process, particularly in the fabrication of parts with delicate overhanging and protruding features. The purpose of this study was to examine the current insight and progress made toward understanding and eliminating the problem in overhanging and protruding structures. To accomplish this, a survey of the literature was undertaken, focusing on process modeling (general, heat transfer, stress and distortion and material models), direct process control (input and environmental control, hardware-in-the-loop monitoring, parameter optimization and post-processing), experiment development (methods for evaluation, optical and mechanical process monitoring, imaging and design-of-experiments), support structure optimization and overhang feature design; approximately 143 published works were examined. The major findings of this study were that a small minority of the literature on SLM/DMLS deals explicitly with the overhanging stress problem, but some fundamental work has been done on the problem. Implications, needs and potential future research directions are discussed in-depth in light of the present review. Full article
(This article belongs to the Special Issue Additive Manufacturing Technologies and Applications)
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Open AccessReview Review of Computational Methods on Brain Symmetric and Asymmetric Analysis from Neuroimaging Techniques
Technologies 2017, 5(2), 16; doi:10.3390/technologies5020016
Received: 26 November 2016 / Revised: 16 April 2017 / Accepted: 17 April 2017 / Published: 18 April 2017
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Abstract
The brain is the most complex organ in the human body and it is divided into two hemispheres—left and right. The left hemisphere is responsible for control of the right side of our body, whereas the right hemisphere is responsible for control of
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The brain is the most complex organ in the human body and it is divided into two hemispheres—left and right. The left hemisphere is responsible for control of the right side of our body, whereas the right hemisphere is responsible for control of the left side of our body. Brain image segmentation from different neuroimaging modalities is one of the important parts of clinical diagnostic tools. Neuroimaging based digital imagery generally contain noise, inhomogeneity, aliasing artifacts, and orientational deviations. Therefore, accurate segmentation of brain images is a very difficult task. However, the development of accurate segmentation of brain images is very important and crucial for a correct diagnosis of any brain related diseases. One of the fundamental segmentation tasks is to identify and segment inter-hemispheric fissure/mid-sagittal planes, which separate the two hemispheres of the brain. Moreover, the symmetric/asymmetric analyses of left and right hemispheres of brain structures are important for radiologists to analyze diseases such as Alzheimer’s, autism, schizophrenia, lesions and epilepsy. Therefore, in this paper, we have analyzed the existing computational techniques used to find brain symmetric/asymmetric analysis in different neuroimaging techniques such as the magnetic resonance (MR), computed tomography (CT), positron emission tomography (PET), single-photon emission computed tomography (SPECT), which are utilized for detecting various brain related disorders. Full article
(This article belongs to the Special Issue Medical Imaging & Image Processing Ⅱ)
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