• Title/Summary/Keyword: G/G 타입

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A Study on Heavy Metal Concentrations of Oxidized Hair Coloring Products in Korea Market (한국에서 유통 중인 산화형 염모제의 중금속 농도에 관한 연구)

  • Choi, Chae Man;Hong, Mi Sun;Lee, Yun Jung;Kim, Hwa Soon;Kim, Hyun Jung;Kim, Jung Hun;Chae, Young Zoo
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.39 no.3
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    • pp.241-249
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    • 2013
  • This study was aimed to provide the fundamental data about oxidized hair color products. For this reason, we collected 125 oxidized hair color products, which were distributed in domestic market from January to October, 2012, and measured the heavy metal concentrations of lead, arsenic, cadmium, chromium, manganese, nickel, copper in the samples. Results were compared by domestic, foreign, henna, type and color. The average metal concentrations were as follows; 0.211 ${\mu}g/g$ for lead, 0.008 ${\mu}g/g$ for cadmium, 0.051 ${\mu}g/g$ for arsenic, 0.954 ${\mu}g/g$ for chromium, 6.250 ${\mu}g/g$ for manganese, 0.591 ${\mu}g/g$ for nickel and 0.544 ${\mu}g/g$ for copper. In case of lead and arsenic, the concentrations were much less than the regulated amount (20 ${\mu}g/g$ and 10 ${\mu}g/g$, respectively) suggested by MFDS (Ministry of Food and Drug Safety). In henna (p < 0.05), the concentrations were significantly higher than those of other domestic and foreign oxidized hair color products as follows; 1.264 ${\mu}g/g$ for lead, 0.267 ${\mu}g/g$ for arsenic, 0.025 ${\mu}g/g$ for cadmium, 4.055 ${\mu}g/g$ for chromium, 72.044 ${\mu}g/g$ for manganese, 3.076 ${\mu}g/g$ for nickel and 4.640 ${\mu}g/g$ for copper. Statistically, it showed that the heavy metal concentrations were quite different for the different types of hair color products. The cream and liquid type products had the highest average concentration in chromium (0.708 ${\mu}g/g$, 0.478 ${\mu}g/g$, respectively). On the other hand, powder type products showed the highest concentration in manganese (60.041 ${\mu}g/g$). In addition, the concentrations of heavy metals and the color of products are not quite correlated. It was shown that average concentrations of lead and chromium were higher for yellow, chromium for red and pink, manganese for brown and black, and nickel for green.

An Evaluation Study on Combustion and Thermal Flow Characteristics of G+R Type Incinerator (G+R 타입 소각연소로의 연소 및 열유동 특성평가 연구)

  • Shin, Dong-Hoon;Shin, Dong-Hoon;Baek, Ik-Hyun;Jung, Sang-Soon
    • 한국연소학회:학술대회논문집
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    • 2003.05a
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    • pp.111-117
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    • 2003
  • The present study discusses about the combustion and thermal flow characteristics of a G+R type incinerator, which is under construction for MAPO Incineration system, to evaluate the effects of various operating and design parameters. A bed combustion model is developed to simulate the waste bed combustion on the stoker. The effects of waste composition and primary air distribution are estimated. The results of the waste bed combustion model is applied to CFD(computational fluid dynamics) simulation, which simulates the detail of the thermal flow in the combustion chamber. The effects of bypass damper opening ratio, primary air distribution, and secondary air jet configuration are discussed.

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Design and Performance Analysis of 5G Mobile Communication Array Antenna in Millimeter-Wave (mm-Wave) Band (밀리미터파(mm-Wave) 대역 5G 이동통신 Array 안테나의 설계와 성능분석 연구)

  • Lee, Sung-hun;Lee, Chang-Kyo;Park, Jae-Hong;Cho, Soo-Hyun;Choi, Seung-Ho;Kim, Tae-Hyung
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.24 no.9
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    • pp.1165-1171
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    • 2020
  • In this study, we designed a single antenna taking into account the performance, such as return loss and radiation pattern, of 28 GHz and 38 GHz array antennas for 5G mobile devices. In millimeter wave band communication, high path loss occurs between transmission and reception, unlike in conventional microwave bands. In the design of array antennas for 5G millimeter wave terminals, antenna performance such as antenna gain, bandwidth, isolation between antenna elements, side-lobe level(SLL), etc. should be further considered. The performance of the designed array antennas was analyzed by spacing the antenna elements at half a wavelength. Our results proved the validity of the design and its suitability for applications in mm-Wave by showing that the 28 GHz and 39 GHz array antennas had antenna gains of 13.5 dBi and 11.3 dBi and return losses below -18.4 dB and -20 dB, correspondingly.