• Title/Summary/Keyword: Physical process

Search Result 5,397, Processing Time 0.029 seconds

Effects of the Contaminants in Papermaking Process Water on Physical Properties of Paper (공정수 내의 오염물질이 종이의 물성에 미치는 영향)

  • 이학래;함충현;이지영
    • Journal of Korea Technical Association of The Pulp and Paper Industry
    • /
    • v.36 no.1
    • /
    • pp.16-23
    • /
    • 2004
  • Recently the increased concerns about the cost reduction and environmental protection make the paper industry increase the closure level of papermaking system, which results in the buildup of organic and inorganic materials in the papermaking process water. Increase of the system closure causes deterioration of additive performance and provokes diverse problems in papermaking process and product quality. To investigate the effects of process water quality on the physical properties of fine papers handsheets were prepared with process water containing various amounts of inorganic and organic contaminants including calcium or sodium ions and oxidized or cationic starches. Inorgainc and organic materials did not show any significant effect on the physical properties of handsheets. Recycled GCC showed the same trends as inorganic and organic materials. The performance of cationic starch was deteriorated, however, in the recycled white water, which resulted in the reduction of tensile index of handsheets.

Exploring Cognitive, Affective, and Physical Aspects of Early Adolescents' Health Information Seeking Behaviors

  • Na, Kyoungsik;Jeong, Yongsun;Yang, Changwoo
    • Journal of the Korean Society for Library and Information Science
    • /
    • v.55 no.2
    • /
    • pp.289-324
    • /
    • 2021
  • This study reports on early adolescents' health information seeking behaviors that investigated cognitive, affective, and physical aspects of behaviors as they experienced to find information on their needs of health information seeking. In spite of the current widespread internet health information use by adolescents, little research exists to illuminate how they are engaged in cognitive, affective, and physical information behaviors in information search process. Qualitative data were collected through individual interviews informed by Kuhlthau's information search process. Forty adolescents from S city in South Korea participated in the project. Findings report thoughts, feelings, and actions aspects of information search process. This study expects to extend our knowledge of the adolescents' health information seeking behaviors of Kuhlthau's information search process.

Sexual Adjustment Process of Individuals with Spinal cord Injury (척수 장애인의 성적 적응 경험)

  • Kang, Hyun-Sook;Koh, Jung-Eun;Suh, Yeon-Ok;Yee, Oon-Hee
    • The Korean Journal of Rehabilitation Nursing
    • /
    • v.3 no.1
    • /
    • pp.80-97
    • /
    • 2000
  • The purpose of this study is to identify and describe a process of sexual adjustment of individuals with spinal cord injury: and to describe and explore positive and negative influences on the adjustment process. This qualitative study was conducted with 10 Korean individuals with spinal cord injury who had been physically disabled for more than one year. Data were collected and analysed at a same time using grounded theory method. Major categories of this study showed a process how the individuals with spinal cord injury adjust to their individual life as sexual beings. The process included and individual responses to the behavioral efforts including and . Initially physical aspects of sexuality seemed to be affected by spinal cord injuries. The changed physical aspects then influenced other aspects of their sexual life. Life satisfaction of each individual as a sexual being revealed as very subjective. It could be defined according to how the individual approved their sexual life no matter what and how much behavioral effort the person had done. In this study 3 types of sexual adjustment aspects were explored: 'Active adjustment' 'Passive adjustment' 'Maladjustment'. There were negative and positive factors influencing the adjustment process of individuals with spinal cord injury. Those factors might come from themselves, from families, or from social situations. Findings of this study suggested that sexual life of individuals with spinal cord injury should not be understood as a physical or behavioral matter. It was a combination of physical, psychological and social aspects of life. Therefore, appropriate rehabilitation programs for the sexual adjustment of individuals with spinal cord injury need to concern heterogeneous life values of them and obtain individualized services for each individual at a different stage of the sexual adjustment process.

  • PDF

Wood Fiber-Thermoplastic Fiber Composites by Turbulent Air Mixing Process(I) - Effects of Process Variables on the Physical Properties of Composites - (난기류 혼합법을 이용한 목섬유-열가소성 섬유 복합재에 관한 연구(I) - 공정변수가 복합재의 물리적 성질에 미치는 영향 -)

  • Yoon, Hyoung-Un;Lee, Phil-Woo
    • Journal of the Korean Wood Science and Technology
    • /
    • v.24 no.3
    • /
    • pp.101-109
    • /
    • 1996
  • Effects of process variables were evaluated in physical properties of the wood fiber-thermoplastic fiber composites using nonwoven web method. Turbulent air mixer using compressed air was employed to mix wood fiber with two types of thermoplastic polypropylene and nylon 6 fibers. The optimal hot press temperature and time were found to be $190^{\circ}C$ and 9 minutes in wood fiber-polypropylene fiber composite and to be $220^{\circ}C$ and 9 minutes in wood fiber-nylon 6 fiber composite. As the density of wood fiber-polypropylene fiber composite and wood fiber-nylon 6 fiber composite increased, the physical properties were improved The density appeared to be the most significant factor on physical properties in the statistical analysis. The composition ratio of polypropylene or nylon 6 fiber to wood fiber was considered not to be statistically significant factor. The thickness swelling decreased somewhat in wood fiber-polypropylene fiber composite and wood fiber-nylon 6 fiber composite as the content of synthetic fiber increased. As the increase of mat moisture content, dimensional stability was improved in wood fiber-polypropylene fiber composite but not in wood fiber-nylon 6 fiber composite.

  • PDF

Physical and Mechanical Properties of Methyl Methacrylate-Impregnated Wood from Three Fast-Growing Tropical Tree Species

  • Hadi, Yusuf Sudo;Massijaya, Muh Yusram;Zaini, Lukmanul Hakim;Pari, Rohmah
    • Journal of the Korean Wood Science and Technology
    • /
    • v.47 no.3
    • /
    • pp.324-335
    • /
    • 2019
  • Timber from plantation forests has inferior physical and mechanical properties compared to timber from natural forest because it is mostly from fast-growing tree species that are cut at a young age. Filling cell voids with methyl methacrylate (MMA) can improve the wood properties. The purpose of this study was to determine the physical and mechanical properties of MMA-impregnated wood from three fast-growing wood species, namely jabon (Anthocephalus cadamba (Roxb.) Miq.), mangium (Acacia mangium Willd) and pine (Pinus merkusii Jungh. & de Vriese). Wood samples were either immersed in MMA monomer or impregnated with it and then heated to induce the polymerization process. Jabon, which was the lowest density wood, had the highest polymer loading, followed by pine and mangium. The physical and mechanical properties of samples were affected by wood species and the presence of MMA, with higher-density wood having better properties than wood with a lower density. Physical and mechanical properties of MMA wood were enhanced compared to untreated wood. Furthermore, the impregnation process was better than immersion process resulting the physical and mechanical properties. Based on MOR values, the MMA woods were one strength class higher compared to untreated wood with regard to Strength Classification of Indonesian Wood.

On the Analysis of Container Physical Distribution System in Pusan Port (부산항 컨테이너 물류 시스템 분석에 관하여)

  • Park, Chang-Ho;Lee, Cheol-Yeong
    • Journal of Korean Port Research
    • /
    • v.5 no.1
    • /
    • pp.55-69
    • /
    • 1991
  • A Container terminal is a physical link between the ocean and land modes of transport and a major component of the container physical distribution system. A number of projects to increase terminal productivity in the world were found to be tied directly to increasing the efficiency of the intermodal activities, that is, to improving the physical distribution process. This is an indication that the productivity of container terminal is being considered withing a system prospective. The purpose of this study is to establish a model of the container physical distribution system for Pusan port linked with 4 sub-systems including Navigational aids system, Cargo handling/transfer/storage system on dock, Off-dock CY system and In-land transport connection system. and to analyze the system. From this analysis, we found that the system had three bottlenecks on the container physical distribution process in Pusan port : a) cargo handling b) storage and c) inland transport, and showed a way to improve the system.

  • PDF

Studies on Composites Using Wood and Nonwood Fibers - Effects of Polypropylene Fiber Length and Process Variables - (목질(木質)과 비목질계(非木質系) 섬유(纖維)를 활용한 복합재(複合材) 연구(硏究) - 폴리프로필렌의 섬유장(纖維長)과 공정변수(工程變數)의 영향(影響)을 중심(中心)으로 -)

  • Lee, Phil-Woo
    • Journal of the Korean Wood Science and Technology
    • /
    • v.25 no.2
    • /
    • pp.33-44
    • /
    • 1997
  • This study was executed to examine the effects of polypropylene fiber length and process variables of the composites made from wood fiber and nonwood fiber mixed formulations. As a nonwood fiber the polypropylene with 3 denier thickness of tow condition was selected and cut into each length of 0.5, 1.0, 1.5, 2.0 and 2.5cm to mix with wood fiber. And also western hemlock wood fiber for medium density fiberboard was prepared. First, to decide an adequate polypropylene mixing fiber length, the composites of 1.0g/$cm^3$ density were made from 10% polypropylene fiber by each of five lengths and 90% western hemlock fiber mixed formulations. Thereafter as the experiments of process variable, the composites applied with adequate polypropylene fiber length(1.5cm) were made from 4 density levels (0.6, 0.8, 1.0, 1.2g/$cm^3$). 3 mixed formulations of wood fiber to polypropylene fiber(95 : 5, 90 : 10, 85 : 15), and 3 mat moisture contents(5, 10, 20%). According to the results and discussions it was concluded as follows ; The physical and mechanical properties were shown improved tendency. as polypropylene fiber length was increased in the range from 0.5 to 1.5cm, but shown decreasing tendency from 2.0 to 2.5 cm. Accordingly, it was shown that polypropylene fiber length is limited to 1.5cm or less length in mixing wood fiber and polypropylene fiber by turbulent air mixing process. As the densities of wood fiber-polypropylene fiber composites were increased, the physical and mechanical properties were clearly improved. Also they were shown significantly increasement statistically between densities respectively. In the mixed formulations, physical and mechanical properties were shown only slightly improvement, as they changed from 95 : 5 to 85 : 15 in wood fiber to polypropylene fiber. Despite of increasement of mat moisture content, mechanical properties were not improved significantly but physical properties were improved somewhat in wood fiber-polypropylene fiber composites.

  • PDF

Application of coagulation pretreatment for enhancing the performance of ceramic membrane filtration (세라믹 막여과의 성능향상을 위한 응집 전처리의 적용)

  • Kang, Joon-Seok;Song, Jiyoung;Park, Seogyeong;Jeong, Ahyoung;Lee, Jeong-Jun;Seo, Inseok;Chae, Seonha;Kim, Seongsu;Kim, Han-Seung
    • Journal of Korean Society of Water and Wastewater
    • /
    • v.31 no.6
    • /
    • pp.501-510
    • /
    • 2017
  • In this study, it is estimated that ceramic membrane process which can operate stably in harsh conditions replacing existing organic membrane connected with coagulation, sedimentation etc.. Jar-test was conducted by using artificial raw water containing kaolin and humic acid. It was observed that coagulant (A-PAC, 10.6%) 4mg/l is the optimal dose. As a results of evaluation of membrane single filtration process (A), coagulation-membrane filtration process (B) and coagulation-sedimentation-membrane filtration process (C), TMP variation is stable regardless of in Flux $2m^3/m^2{\cdot}day$. But in Flux $5m^3/m^2{\cdot}day$, it show change of 1-89.3 kpa by process. TMP of process (B) and (C) is increased 11.8, 0.6 kpa each. But, the (A) showed the greatest change of TMP. When evaluate (A) and (C) in Flux $10m^3/m^2{\cdot}day$, TMP of (A) stopped operation being exceeded 120 kpa in 20 minutes. On the other hand, TMP of (C) is increased only 3 kpa in 120 minutes. Through this, membrane filtration process can be operated stably by using the linkage between the pretreatment process and the ceramic membrane filtration process. Turbidity of treated water remained under 0.1 NTU regardless of flux condition and DOC and $UV_{254}$ showed a removal rate of 65-85%, 95% more each at process connected with pretreatment. Physical cleaning was carried out using water and air of 500kpa to show the recovery of pollutants formed on membrane surface by filtration. In (A) process, TMP has increased rapidly and decreased the recovery by physical cleaning as the flux rises. This means that contamination on membrane surface is irreversible fouling difficult to recover by using physical cleaning. Process (B) and (C) are observed high recovery rate of 60% more in high flux and especially recovery rate of process (B) is the highest at 95.8%. This can be judged that the coagulation flocs in the raw water formed cake layer with irreversible fouling and are favorable to physical cleaning. As a result of estimation, observe that ceramic membrane filtration connected with pretreatment improves efficiency of filtration and recovery rate of physical cleaning. And ceramic membrane which is possible to operate in the higher flux than organic membrane can be reduce the area of water purification facilities and secure a stable quantity of water by connecting the ceramic membrane with pretreatment process.

Fabrication of Nanocomposite Powders by Sonochemical Method

  • Hayashi, Yamato;Sekino, Tohru;Niihara, Koichi
    • Journal of Powder Materials
    • /
    • v.8 no.3
    • /
    • pp.207-209
    • /
    • 2001
  • Nano particles have recently been a major research interest, motivated by their unusual physical and chemical properties. Such particles can be synthesized using physical and chemical methods. The physical methods need expensive installation like vacuum induction furnace, whereas in chemical methods the process in generally very simple and low cost. In this study, simple and new fabrication process by using ultrasound was investigated to prepare the nano-sized metal particles on various powders at room temperature.

  • PDF

A Study on Expressive Trends of ′Sachlichkeit′ in Architectural Design (건축디자인에 있어서 ′즉물성′의 표현경향에 관한 연구)

  • 배준현;전명현
    • Korean Institute of Interior Design Journal
    • /
    • no.26
    • /
    • pp.121-128
    • /
    • 2001
  • This study deals with 'Sachlichkeit' , as essence of materiality that architectural building materials process, which forms the physical basis for actual building. There have beennu merous researches that deals with various elements that compose architecture, but the emphasis seemed to be concentrated on the meta-physical discussion concerning formal concept. An issue on sachlichkeit as materiality does not necessary mean to mention production process of architecture, rather it is aim of this study to seek possibility to find elements that generate architectural form, through interpreting meaning of materials as substructure generator to make architectural possible. Architectural act can be defined as a process where physical material in life is composed into architecture by the hands of architect. Material used in life is composed into architecture by the hands of architect. Material used in this process basically has neutral characteristic, so 'Sachlichkeit'solely depends on the intentions of architects. This study interprets the intention of architects through the frame of modern-basis proposed by Hilberseimer, and a result architecture is defined as an object projected by architect's subjectivity.

  • PDF