• Proceedings of the Korean Vacuum Society Conference
• /
• 2014.02a
• /
• pp.342.1-342.1
• /
• 2014

The electrical, optical and structural properties of Ti doped $In_2O_3$ (TIO) ohmic contacts to p-type GaN were investigated using linear facing target sputtering (LFTS) system. Sheet resistance and resistivity of TIO films are decreased with increasing rapid thermal annealing (RTA) temperature. Although the $400^{\circ}C$ and $500^{\circ}C$ annealed samples showed rectifying behavior, the $600^{\circ}C$ and $700^{\circ}C$ annealed samples showed linear I-V characteristics indicative of the formation of an ohmic contact between TIO and p-GaN. The annealing of the contact at $700^{\circ}C$ resulted in the lowest specific contact resistivity of $9.5{\times}10^{-4}{\Omega}cm^2$. Based on XPS depth profiling and synchrotron X-ray scattering analysis, we suggested a possible mechanism to explain the annealing dependence of the properties of TIO layer on rapid thermal annealing temperature.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2017.05a
• /
• pp.169-170
• /
• 2017

Recently in the construction industry there has been an increasing use of increasing replacement of cement with blast furnace slag cement(BS), an industrial by-product, to reduce environment load and production costs, and other increasing uses of BS cement. However in the case of BS being delivered in RMC factories, only score reports submitted when the are delivered are relied upon and ways to test the quality of fineness is inadequate. Therefore this study gave many changes to various cements and BS fineness to test the variations of BS as a cement, then used the correlation between this and the density value in the Hydrometer method to test the possibility for rapid appraisal of quality fineness of BS cement. Results showed that if the one fifth graph of the density and fineness correlation were to be used, a rapid appraisal of BS cement fineness quality would be possible.

• Journal of Powder Materials
• /
• v.6 no.2
• /
• pp.145-151
• /
• 1999

Nickel silicides ($Ni_5$Si$_2$, Ni$_2$Si and NiSi) have been synthesized by mechanical alloying (MA) of Ni-27.9at.9at%Si, Ni-33.3at% and Ni-50.0at% powder mixtures, respectively. From in situ thermal analysis, eash citical milling period for the formation of the three phases was observed to be 40.2, 34.9 and 57.5 min, at which there was a rapid increase in temperature. This indicates that rapid, self-propagating high-temperature synthesis (SHS) reactions were observed to produce the three phases during room-temperature high-energy ball milling of elemental powders. Each Ni silicide, Ni and Si, however, coexisted for an extended milling time even after the critical milling period. The powders mechanically alloyed after the critical period showed the rapid increase in microhardness. The Hv values were found to be higher than 1000kgf/mm$^2$. The formation of nickel silicides by mechanical alloying and the relevant reaction rates appeared to be influenced by the critical milling period and the heat of formation of the products involved ($Ni_5$Si$_2$$\rightarrow$-43.1kJ/mol.at., Ni$_2$Si$\rightarrow$-47.6kJ/mol.at., NiSi$\rightarrow$-42.4kJ/mol.at).

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.16 no.11
• /
• pp.1179-1185
• /
• 1991

Ultrathin Reoxidized Nitrided Oxides were formed by lamp heated rapid thermal annealing in oxyzen at temperatures of $1050^{\circ}C$-$1100^{\circ}C$ for 20, 40 seconds. The electrical characteristics of ultrathin films were evaluated by leakage current breakdown voltage. TDDB. FN tunneling. Nitridation and reoxidition condition dependence of charge trapping properties. i.e.. the flat band voltage shift $({\Delta}V_{FB})$ and the increase of charge-to-breakdown $(Q_{BD})$ induced by a high field stress where studied. As the results of analysis. rapid thermal reoxidation was achieved striking improvement of dielectric integrity, the charge to breakdown was increased and flat band voltage shift was reduced.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.29 no.2
• /
• pp.95-100
• /
• 2016

We fabricated a tin sulfide (SnS) layer with Sn/Mo/glass layers followed by a RTP (rapid thermal processing), and studied the film growth and structural characteristics as a function of annealing temperature and time. The elemental sulfur (S) was cracked thermally and applied to form SnS polycrystalline film out of the Sn percursor at pre-determined pressures in the RTP tube. The sulfurization was done at the temperature from $200^{\circ}C$ to $500^{\circ}C$ for a time period of 10 to 40 min. At ${\leq}300^{\circ}C$, 20 min., p-type SnS thin films was grown and showed the best composition of at.% of [S]/[Sn] $${\sim_=}$$ 1 and [111] preferred orientation as investigated from using XRD (X-ray diffraction) analysis and EDS (energy dispersive spectroscopy) and SEM (scanning electron microscopy), and optical absorption by a UV-VIS spectrometer. In this paper, we report the details of growth characteristics of single phase SnS thin film as a function of annealing temperature and time associated with the pressure and ambient gas in the RTP tube.

• Steel and Composite Structures
• /
• v.18 no.3
• /
• pp.547-563
• /
• 2015

Deflection in a beam of a composite frame is a serviceability design criterion. This paper presents a methodology for rapid prediction of long-term mid-span deflections of beams in composite frames subjected to service load. Neural networks have been developed to predict the inelastic mid-span deflections in beams of frames (typically for 20 years, considering cracking, and time effects, i.e., creep and shrinkage in concrete) from the elastic moments and elastic mid-span deflections (neglecting cracking, and time effects). These models can be used for frames with any number of bays and stories. The training, validating, and testing data sets for the neural networks are generated using a hybrid analytical-numerical procedure of analysis. Multilayered feed-forward networks have been developed using sigmoid function as an activation function and the back propagation-learning algorithm for training. The proposed neural networks are validated for an example frame of different number of spans and stories and the errors are shown to be small. Sensitivity studies are carried out using the developed neural networks. These studies show the influence of variations of input parameters on the output parameter. The neural networks can be used in every day design as they enable rapid prediction of inelastic mid-span deflections with reasonable accuracy for practical purposes and require computational effort which is a fraction of that required for the available methods.

• Food Science and Biotechnology
• /
• v.16 no.1
• /
• pp.67-70
• /
• 2007

Mackerel (Scomber japonicus) often causes severe allergic reactions in sensitive people. Food containing undeclared mackerel may pose a risk to such people. The major allergenic protein in fish such as mackerel, codfish, and Alaska pollack has been found to be parvalbumin. In this study, we developed a polymerase chain reaction (PCR) method to detect mackerel DNA using primers corresponding to the parvalbumin gene. We cloned and sequenced 1.5 kb of parvalbumin gene by PCR using mackerel genomic DNA as a template. Nucleotide sequence analysis of genomic parvalbumin gene, composed of 4 exons and 3 introns, allowed the selection of two pairs of oligonucleotide primers specific for mackerel. These primers successfully enabled PCR amplification of specific regions of genomic parvalbumin DNA from mackerel, but no amplification from 8 other fish samples, surimi, and 6 boiled fish pastes. The sensitivity of this method was sufficient to detect 5 ng of purified mackerel DNA mixed with 50 ng of surimi DNA. This rapid and specific method for the detection of allergenic mackerel would be beneficial in reducing food allergy caused by the ingestion of hidden allergen in processed food.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.29 no.5
• /
• pp.65-70
• /
• 2015

Lightning is one of hazards affecting the rapid-transit railway system. There are two effects, which are direct lightning surge to electric car line and induced lightning surge. Protection methods for the direct lightning surge are studied with various occasions, however, study of induced lightning surge is insufficient in spite of a large or small effects. In this paper, it is analysed the way that serge voltage is induced to electric car line by lightning strikes. By modeling the propagation process and the coupling phenomenon of electromagnetic wave produced by lightning strikes, it is achieved to make integrative circuit model combined with existing electric car model. The study is conducted into three different waveform of electromagnetic wave produced by lightning; rectangular wave, double exponential distribution wave, triangle wave. It is also simulated that the inducing serge is coupled to electric car line in an arbitrary location. The simulation results in that, when rapidly changing rectangular wave is supplied, maximum power is induced to electric car line.

• Advances in Energy Research
• /
• v.7 no.2
• /
• pp.135-146
• /
• 2020

In developing countries especially in African continent, rapid population growth in cities is a major concern. Majority of governments in Africa have made more effort to develop urban areas as compared to the rural ones. Social and economic activities are more concentrated in urban areas. This is a pushing factor for the rapid population growth in cities as many people, especially young generation, tend to migrate from rural to urban. This growth leads to excessive exploitation of natural resources, environmental degradation and increased pressure on social services. Rapid increased population acts as an encouragement to construct smart cities for achieving needs for present and future generations. Tanzania as one of the developing countries in Africa has taken initiatives in establishing smart cities. The aim of this study therefore, is to examine opportunities and challenges in the development of Smart cities in Tanzania with a case study of Mbeya city. In addition, conceptualization about development of smart cities is proposed to prioritize the planning of smart grid among other smart city infrastructure systems. Conclusively, Mbeya city has a full potential of many strengths and opportunities for successful development as a smart city.

• ETRI Journal
• /
• v.41 no.5
• /
• pp.670-683
• /
• 2019

In this paper, we analyzed the signal integrity of a system interconnection module for a proposed high-density server. The proposed server integrates several components into a chassis. Therefore, the proposed server can access multiple computing resources. To support the system interconnection, among the highly integrated computing resources, the interconnection module, which is based on Serial RapidIO, has been newly adopted and supports a bandwidth of 800 Gbps while routing 160 differential signal traces. The module was designed for two different stack-up types on a printed circuit board. Each module was designed into 12- (version 1) and 14-layer (version 2) versions with thicknesses of 1.5T and 1.8T, respectively. Version 1 has a structure with two consecutive high-speed signal-layers in the middle of two power planes, whereas Version 2 has a single high-speed signal placed only in the space between two power planes. To analyze the signal integrity of the module, we probed the S-parameters, eye-diagrams, and crosstalk voltages. The results show that the high-speed signal integrity of Version 2 has a better quality than Version 1, even if the signal trace length is increased.