• Title/Summary/Keyword: ratio of surface area to weight

Search Result 119, Processing Time 0.03 seconds

Study on Characteristics and Preparation of Binderless ZSM-5 Granules for Adsorption of Xylene Isomers (Binderless ZSM-5 성형체의 합성 및 자일렌 이성체의 흡착 특성에 관한 연구)

  • Yun, Hyo-Sang;Hong, Ji-Sook;Suh, Jeong-Kwon;Shin, Chae-Ho
    • Applied Chemistry for Engineering
    • /
    • v.21 no.4
    • /
    • pp.417-423
    • /
    • 2010
  • In this study, an effective method to prepare granular binderless ZSM-5 which is as efficient p-xylene separatory adsorbent was explored. Colloidal silica sol 30 wt% solution as an inorganic binder and microcrystalline cellulose as an organic additive were added to ZSM-5 powder ($SiO_2/Al_2O_3$ = 50). Adsorbent with enough strength (0.721 kgf), high crystallinity (94.6%) and high BET specific surface area ($379.2m^2$/g) was obtained by calcination, binderless treatment, ${NH_4}^+$ ion exchange, and activation after spherical granulation process. A batch type adsorption experiment was proceeded with solutions comprising 3 xylene isomers by 1 : 1 : 1 weight ratio to evaluate adsorption characteristics of prepared absorbent. As a result, the obtained binderless ZSM-5 granule showed a higher selective adsorption performance for para-xylene than that of commercial adsorbent.

Cardiac function associated with home ventilator care in Duchenne muscular dystrophy

  • Lee, Sangheun;Lee, Heeyoung;Eun, Lucy Youngmin;Gang, Seung Woong
    • Clinical and Experimental Pediatrics
    • /
    • v.61 no.2
    • /
    • pp.59-63
    • /
    • 2018
  • Purpose: Cardiomyopathy is becoming the leading cause of death in patients with Duchenne muscular dystrophy because mechanically assisted lung ventilation and assisted coughing have helped resolve respiratory complications. To clarify cardiopulmonary function, we compared cardiac function between the home ventilator-assisted and non-ventilator-assisted groups. Methods: We retrospectively reviewed patients with Duchenne muscular dystrophy from January 2010 to March 2016 at Gangnam Severance Hospital. Demographic characteristics, pulmonary function, and echocardiography data were investigated. Results: Fifty-four patients with Duchenne muscular dystrophy were divided into 2 groups: home ventilator-assisted and non-ventilator-assisted. The patients in the home ventilator group were older ($16.25{\pm}1.85years$) than those in the nonventilator group ($14.73{\pm}1.36years$) (P=0.001). Height, weight, and body surface area did not differ significantly between groups. The home ventilator group had a lower seated functional vital capacity ($1,038{\pm}620.41mL$) than the nonventilator group ($1,455{\pm}603.2mL$). Mean left ventricular ejection fraction and fractional shortening were greater in the home ventilator group, but the data did not show any statistical difference. The early ventricular filling velocity/late ventricular filling velocity ratio ($1.7{\pm}0.44$) was lower in the home ventilator group than in the nonventilator group ($2.02{\pm}0.62$. The mitral valve annular systolic velocity was higher in the home ventilator group (estimated ${\beta}$, 1.06; standard error, 0.48). Patients with Duchenne muscular dystrophy on a ventilator may have better systolic and diastolic cardiac functions. Conclusion: Noninvasive ventilator assistance can help preserve cardiac function. Therefore, early utilization of noninvasive ventilation or oxygen may positively influence cardiac function in patients with Duchenne muscular dystrophy.

Effect of Knitting Condition on the Deformation Behavior of the Weft-knitted Fabrics (위편성포의 변형거동에 관한 연구)

  • Choi, Mee-Sung;Kim, Sang-Yool
    • Fashion & Textile Research Journal
    • /
    • v.1 no.3
    • /
    • pp.280-287
    • /
    • 1999
  • The aims of this research were to study on the relationship between the mechanical properties and the deformation behavior of weft-knitted fabrics as a function of knit structure and knit density. Eighteen weft-knitted fabrics were produced with six different knit structures ($1{\times}1$ rib, half-cardigan rib, half-milano rib, interlock, single-pique, and crossmiss interlock) and three different knit densities (loose, medium, tight). The mechanical properties of these samples were measured using the KES-F system. The 2HBIW increased as knit density was raised. The increase was greater for the double knit fabrics in all samples. Half-milano rib and crossmiss interlock samples showed the lowest 2HG/G values. The double knits were smaller than those of single knits indicate a higher degree of surface smoothness. The ratio of compression energy to weight per unit area of the double knits had lower values than the single knits.

  • PDF

Measurement of Leaf Area of Soybeans (대두엽면적의 간이측정법)

  • Kwon-Yawl Chang
    • KOREAN JOURNAL OF CROP SCIENCE
    • /
    • v.4 no.1
    • /
    • pp.93-95
    • /
    • 1968
  • The importance of leaf area as related to transpiration and photosynthesis is generally recognized. In general, a compound leaf of soybean consist of one main leaflet and two side leaflets from each node of the stem. Takahashi and Fukuyama (1919) classified soybeans into three types, namely the long leaf type, round leaf type, and intermediate type, in which the last one had round leaves at the base and long leaves in the upper part of the stem. Nagai (1925) and Takahashi (1935). dealt with the genetics of the leaf form and association with other characters. The closely relationships, the correlation coefficients from 0.64 to 0.73, were shown between the leaf area and the soybean yield in the experiments by Nagai (1942). Nagata (1950) also tested the varietal differences of the variation of leaf length and its ratio to the leaf width on the nodes of stem, and finally divided varieties into five types. Three methods of measuring area of strawberry leaves were used by Darrow (1932). The first involved determining a factor to be used with length or length ${\times}$width measurements. The second method involved placing leaves on pieces of cardboard of known area cut to the shape of the leaves. Direct use of the planimeter on intact leaves was Darrow's third method. Miller (1938) enumerated several methods to determine the leaf surface area in plants, some of which were extremely laborious and required removing leaves from plants. They included tracing outlines of leaves on paper and measuring the enclosed area with a planimeter or cutting out the traced areas and comparing the weights obtained with the weight of a known paper. Another method involved placing the form of the leaf on sensitized paper with the area being determined by measuring or weighing as above. Miller further stated that the photoelectric cell can also be utilized to estitmate leaf area. Working with field beans, Davis (1940) found that 0.004517 (length ${\times}$ width) of the center leaflet was the most nearly accurate of four methods attempted. A simple procedure to measure leaf area in corn was devised 1 y Montgomery (1911) and used by Kiesselbach (1950). The formula was length ${\times}$ width ${\times}$ 0.75. Stickler et al. (1961) have successfully used length times width ${\times}$ 0.747 to estimate area of grain sorghum leaves. Bhan and Pande(1966) has also used length ${\times}$ width ${\times}$ 0.802 to determine leaf area of rice varieties. The main objectives of the present investigation were to develop an accurate, rapid method to determine leaf area in soybean varieties and to examine certain data associated with leaf area determinations.

  • PDF

Preparation and Characterization of Activated Carbon Derived from Leather Waste Discharged from Shinpyung Changrim Industrial Complex (신평 장림공단 피혁폐기물(皮革廢棄物)을 이용한 활성탄(活性炭) 제조(製造) 및 특성(特性))

  • Park, Seung-Cho;Nam, Jeong-Kwang;Kim, Jung-Sup
    • Resources Recycling
    • /
    • v.17 no.1
    • /
    • pp.20-28
    • /
    • 2008
  • Leather waste discharged from Shinpyung Changrim Industrial Complex contained 46.3 percent of carbon, and weight loss of leather waste about 50 percent was observed at $500^{\circ}C$ by thermogravimetric analysis. Chemically activated carbon [LW4AC] was made at activation temperature of $800^{\circ}C$ during 30 minutes in electric furnace. Iodine value and decoloration of methylene blue was 968 mg/g and 158 mL/g, respectively. We found that pore volume was more developed according to the increase in the ratio of $K_2CO_3/LW$.

Response of circular footing on dry dense sand to impact load with different embedment depths

  • Ali, Adnan F.;Fattah, Mohammed Y.;Ahmed, Balqees A.
    • Earthquakes and Structures
    • /
    • v.14 no.4
    • /
    • pp.323-336
    • /
    • 2018
  • Machine foundations with impact loads are common powerful sources of industrial vibrations. These foundations are generally transferring vertical dynamic loads to the soil and generate ground vibrations which may harmfully affect the surrounding structures or buildings. Dynamic effects range from severe trouble of working conditions for some sensitive instruments or devices to visible structural damage. This work includes an experimental study on the behavior of dry dense sand under the action of a single impulsive load. The objective of this research is to predict the dry sand response under impact loads. Emphasis will be made on attenuation of waves induced by impact loads through the soil. The research also includes studying the effect of footing embedment, and footing area on the soil behavior and its dynamic response. Different falling masses from different heights were conducted using the falling weight deflectometer (FWD) to provide the single pulse energy. The responses of different soils were evaluated at different locations (vertically below the impact plate and horizontally away from it). These responses include; displacements, velocities, and accelerations that are developed due to the impact acting at top and different depths within the soil using the falling weight deflectometer (FWD) and accelerometers (ARH-500A Waterproof, and Low capacity Acceleration Transducer) that are embedded in the soil in addition to soil pressure gauges. It was concluded that increasing the footing embedment depth results in increase in the amplitude of the force-time history by about 10-30% due to increase in the degree of confinement. This is accompanied by a decrease in the displacement response of the soil by about 40-50% due to increase in the overburden pressure when the embedment depth increased which leads to increasing the stiffness of sandy soil. There is also increase in the natural frequency of the soil-foundation system by about 20-45%. For surface foundation, the foundation is free to oscillate in vertical, horizontal and rocking modes. But, when embedding a footing, the surrounding soil restricts oscillation due to confinement which leads to increasing the natural frequency. Moreover, the soil density increases with depth because of compaction, which makes the soil behave as a solid medium. Increasing the footing embedment depth results in an increase in the damping ratio by about 50-150% due to the increase of soil density as D/B increases, hence the soil tends to behave as a solid medium which activates both viscous and strain damping.

Spatio-Temporal Variation Characteristics of Primary Productivity and Environmental Factors of Shellfish Mariculture in Jaran Bay, Korea (자란만 패류양식어장의 기초생산력 및 환경인자 변동 특성)

  • Lee, Dae In;Choi, Yong-Hyeon;Hong, SokJin;Kim, Hyung Chul;Lee, Won-Chan
    • Journal of the Korean Society of Marine Environment & Safety
    • /
    • v.28 no.5
    • /
    • pp.721-734
    • /
    • 2022
  • This study analyzed the spatio-temporal variation characteristics of major environmental factors such as primary productivity (PP), chlorophyll a, nutrients, sinking particle matters, and organic contamination and biochemical composition of surface sediment on a monthly basis for approximately 2 years around shellfish mariculture in Jaran Bay, Korea. In addition, PP in Jaran Bay was compared with that in other coastal areas and related policy plans were proposed. The average PP of the study area was high in summer and autumn with 6.43~115.43 mgC m-2 hr-1 range. This was lower than that in Gamak Bay and Masan Bay, whereas higher than that in Garorim Bay and the West Sea. The PP in coastal waters, where many aquaculture farms were distributed, significantly fluctuated. The different size compositions of phytoplanktons constituting chlorophyll a slightly varied by month, and little restriction existed on the productivity of phytoplanktons owing to the depletion of nutrients. Typically, the Redfield ratio was less than 16, indicating that nitrogen was the limiting factor for the growth of phytoplanktons. The biochemical composition of particulate organic matters in the water column showed the highest carbohydrates, but lipids and protein contents were high in surface sediments. The concentration of TOC and AVS of the surface sediments was high at inside of bay, and sometimes, exceeded the environmental criteria of fishing grounds. The organic C:N ratio of sediments ranged from 8.1 to 10.4 on average. PP had the highest correlation with chlorophyll a, nitrogen and protein of particle organic materials. Recently, chlorophyll a, DIN, and DIP of water column trends tended to decrease, however, the contamination of sediments increased. Considering the annual PP of 125.9 gC m-2 yr-1 and mariculture area (oyster) of 4.97 km2, the annual carbon production from phytoplanktons was estimated to be about 625 tons, and the annual total wet weight of shellfish (oyster) was estimated to be about 6,250 tons.

Characteristics of Non-Spherical Manganese Nodule from the East Siberian Sea (동시베리아해 비구형 망가니즈단괴의 특성)

  • Koo, HyoJin;Park, MuSeong;Seo, ChoongMan;Cho, HyenGoo
    • Korean Journal of Mineralogy and Petrology
    • /
    • v.34 no.4
    • /
    • pp.241-253
    • /
    • 2021
  • Manganese nodules have been found in the shallow water depth of the Arctic Ocean as well as in the abyssal plains of the Pacific and Indian Oceans, but detailed study for them were rarely investigated. Manganese nodules, collected from the East Siberian Sea through the Arctic Expedition using Araon ice braking vessel, have a high potential for Mn mineral resources because they have high Mn content with high Mn/Fe ratio. This study investigated the external form, size and weight, internal texture for the non-spherical manganese nodule, which has about 7 % of total nodule from the East Siberian Sea. This study also researched the relative Mn-oxide mineral composition using the peak area ratio of X-ray diffraction pattern and their chemical composition. All data obtained from non-spherical nodules were compared with the spherical ones. Ellipsoidal, platy and irregular types are common among 5 groups of non-spherical manganese nodule based on the external form, and major axis and weight have positive relationship. All non-spherical manganese nodules have core mainly composed of mud sediments. The average Mn oxide mineral contents in nodules are birnessite, buserite and todorokite in descending order. Although mineral composition does not show any correlation with the external form, kind of core or internal structure, todorokite and buserite contents tend to increase and birnessite content decrease from the surface to the core in the nodule. Non-spherical manganese nodules have higher Mn content and Mn/Fe ratio than those from the shallow water depth of the Arctic Sea and even in the deep-sea of the Pacific and Indian Ocean. Although non-spherical nodule is larger and heavier, and has lower Mn content and Mn/Fe ratio than spherical nodule, there are not any differences in mineral composition and internal structure between them. Almost all manganese nodules collected from the East Siberian Sea are attributed to diagenetic process, because they are higher than 5 in Mn/Fe ratio.

Development of Packaging Materials for MA Packaging(1) (MA포장용 기능성 포장 소재개발에 관한 연구(1))

  • Park, Hyung-Woo;Park, Moo-Hyun;Kim, Hoon;Lee, Jae-Young;Yang, Han-Chul
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
    • /
    • v.3 no.2
    • /
    • pp.25-31
    • /
    • 1996
  • Various treaments such heating, acid tenting, acid healing, alkaline treating, acid+alkaline renting were attempted to investigate their effects on molar ratio, chemical composition, DTA and specific surface area(SSA) of natural zeolite poder. Molar ratio, Si to AI. of natural zeolite was 4.78, which represented high silica type. Composition of natural zeolite showed that $SiO_2$ was 66.34% $Al_2O_3$ was 13.89%, $Fe_2O_2$ was 1.55% X-ray diffraction showed that main component of natural zeolite was mordenite and clinoptliolite. Differential Thermal Analysis and Thermogravimetry curve of natural zeolite was showed to peak of endothermic peak at $80^{\circ}C$ and it means to the peak of dehydrate reaction, but recristalization was not formed below at $1,000^{\circ}C$. Weight loss during calcination was 16% at $1,000^{\circ}C$. Thermal treatments on SSA of natural zolite powder decreased from $75.2m^2/g\;to\;2.1m^2/g$. In contrast chemical treatments on SSA showed to increase to $300.2m^2/g$(1 N HCl treating), $54.9m^2/g$(1 N NaOH) and $90.9m^2/g$(HCl+NaOH)tudy, it could be proposed to employ acid tret method as packaging materisls for MA packaging.

  • PDF

Mungbean Cultivar, 'Munpyeong', with a Short Stem and High Yield (단경 다수성 녹두 품종 '문평')

  • Kim, Dong-Kwan;Choi, Jin-Gyung;Kwon, Oh-Do;Lee, Kyung-Dong;Seo, Min-Jung;Kim, Hyun-Tae
    • Korean Journal of Breeding Science
    • /
    • v.50 no.4
    • /
    • pp.485-489
    • /
    • 2018
  • A mungbean cultivar "Munpyeong" (Vigna radiata (L.) Wilczek) was derived as a cross between "Keumseong" and "IT163157" at the Jeollanamdo Agricultural Research and Extension Services (JARES) in 2013. "Munpyeong" has an erect growth habit, heart leaflet, green hypocotyls, black and straight pods when matured, and a dull green seed surface. The stem length of "Munpyeong" was 60 cm, which was 6 cm shorter than that of the control cultivar "Owool." The pod number per plant was 25, which was 3 more than that of the control cultivar. The 1000 seed weight of "Munpyeong" was 45 g, which was 4 g lighter than that of the control cultivar "Owool." Its field resistance to mungbean mottle virus, cercospora leaf spot, and powdery mildew are similar to the control cultivar, whereas its field resistance to lodging was slightly stronger. The hard seed rate of "Munpyeong" was 3.2%, which was similar to that of the control cultivar. The sprout yield ratio was 7.54 times, which was 9% more than that of the control cultivar. The average yield of "Munpyeong" was 1.93 ton/㏊, which was 21% more than that of the control cultivar "Owool" (Cultivar registration number: 5878).