• Steel and Composite Structures
• /
• v.35 no.1
• /
• pp.1-12
• /
• 2020

This article deals with the buckling analysis in the plates containing carbon nanotubes (CNTs) subject to axial load. In order to control the plate smartly, a piezoelectric layer covered the plate. The plate is located in elastic medium which is modeled by spring elements. The Mori-Tanaka low is utilized for calculating the equivalent mechanical characteristics of the plate. The structure is modeled by a thick plate and the governing equations are deduced using Hamilton's principle under the assumption of higher-order shear deformation theory (HSDT). The Navier method is applied to obtain the bulking load. The effects of the applied voltage to the smart layer, agglomeration and volume percent of CNT nanoparticles, geometrical parameters and elastic medium of the structure are assessed on the buckling response. It has been demonstrated that by applying a negative voltage, the buckling load is increased significantly.

• Pediatric Gastroenterology, Hepatology & Nutrition
• /
• v.12 no.sup1
• /
• pp.111-117
• /
• 2009

Constipation is one of the most common symptoms that a child visits pediatrician. The general approach to the child with functional constipation includes the following steps; disimpaction, maintenance and withdrawal of medication. There are many drugs which can be applied to children; osmotic agents (lactulose, sorbitol, magnesium hydroxide/citrate, polyethylene glycol with/without electrolytes, sodium phosphate, glycerin), stimulants (senna, bisacodyl, caster oil), lubricant (mineral oil), bulking agent (psyllium, cellulose, glucomannan). At each stage of treatment, one or some of these drug can be applied to the purpose. The author tries to summarize recent studies on drugs for constipation in child, and finally introduces new dugs for constipation which is under investigation.

• Proceedings of the Korean Society for Applied Microbiology Conference
• /
• 1979.10a
• /
• pp.240.1-240
• /
• 1979

하천, 호소등의 자정작용(Stream self purification), 즉 미생물에 의한 수중의 유기물의 안정화는, 유기물의 산화분해와 미생물세포의 합성이라는 두가지 대사과정의 조합에 의해 달성된다. 미생물에 의한 폐수처리는, 상술한 자연계의 자정작용을 인공적으로 관리, 운영하는 것이다. 즉, 미생물은 폐수중의 유기영양물을 산화분해하므로써 세포의 합성과 유지에 필요한 energy를 획득하며, 한편 폐수중의 유기물은 산화되어 안정화된다. 이산화반응을 생물학적산화라고 하며, 호기적산화와 혐기적산화의 두가지 형식으로 구별된다. 여기서는 폐수처리에 관여하는 미생물의 분류, 또 폐수처리의 형식으로 호기적산화(산화지, 활성 오이법, 산포처상법 및 회전원판법)와 혐기적산화(Methane발효법)에 대해서 설명한다. 활성오이법 에서 bulking 현상에 대해서도 언급하며, 미생물에 의한 폐수처리의 원리와함께 동력학식의 활성오이법에의 응용에 대해서도 설명한다.

• Proceedings of the Membrane Society of Korea Conference
• /
• 1998.10a
• /
• pp.150-152
• /
• 1998

Now the lack of water is serious problem all over the world because of the growth of population and expansion of industrial activities. So wastewater recycle and reuse is essential in many countries. One of the most popular wastewater treatment processes is conventional activated sludge system. In spite of significant degree of treatment rate the biological process has some operational difficulties and capital disadvantages. In conventional activated sludge process, sludge settling condition is getting worse in case of sludge bulking, it is common that overall process fails due to wash-out of biomass causing low concentration of MLSS in the aeration tank. Because of the absence of claifier the membrane bioreactor(MBR) process is less affected by such problems.

• Journal of Korean Society of Water and Wastewater
• /
• v.19 no.3
• /
• pp.295-300
• /
• 2005

The performances of electroflotation (EF) on the thickening of activated sludge were investigated using laboratory scale batch flotation reactors. Four activated sludges including bulking sludges were tested. After 30minutes of EF operation, 57-84 % of sludge volume reduction could be achieved by EF, while only about 1.5-14% could be obtained by gravity thickening for the same period. After thickening the effluent water quality in terms of TCOD, SS, and turbidity was improved by EF operation for all sludge samples. It is induced that the air bubbles entrapped in the thickened sludge play a key role in the observed improvement of sludge thickening and effluent quality.

• Journal of Animal Science and Technology
• /
• v.55 no.5
• /
• pp.483-488
• /
• 2013

To develop a sustainable composting method for livestock mortality, a natural aeration-composting process was designed and the influences of bulking materials on the mortality composting process were studied. Bulking materials (e.g., compost, swine manure, sawdust, and rice husks), easily supplied at the scene of an animal mortality outbreak, were tested in this research. A lab-scale composting system (W34 ${\times}$ L60 ${\times}$ H26 cm) was made using 100 mm styrofoam, and natural aeration was achieved through pipes installed on the bottom of the system. Four treatments were designed (compost, compost + swine feces, sawdust, and rice husks treatment groups) and all experiments were done in triplicates. During composting for 40 days, no leachate was observed in compost and sawdust treatment groups, whereas 18 and 8.2 ml leachate/kg-mortality was emitted from the compost + feces and rice husks treatment groups, respectively. Dimethyl disulfide (DMDS) emission during the composting was very low in all treatment groups, possibly due to the bio-filtering function of the compost cover layer on the pile. The mortality degradability in compost, compost + feces, sawdust, and rice husks groups was 25.3, 25.8, 13.5, and 14.5%, respectively, showing significantly higher levels in compost and compost + feces groups (p<0.05). Also, only the compost + feces group produced enough heat (over $55^{\circ}C$) and lasted for 7 days, indicating that bio-security cannot be guaranteed without feces supplementation.

• Korean Journal of Soil Science and Fertilizer
• /
• v.43 no.3
• /
• pp.329-334
• /
• 2010

The characteristics of nitrogen mineralization in upland soil was studied with 27-week incubation at $25^{\circ}C$. The used soils in this experiment were received six kinds of livestock manure compost each year for four years. Six different composts, which were chicken (CHM), pig (PIM), and cow (COM) manure composted without bulking agent, and chicken (CHMS), pig (PIMS), and cow (COMS) manure composted with sawdust as a bulking agent, were selected for this study. The first-order model was fit to the observed mineral nitrogen (N) vs incubation days using a non-linear regression procedure. The soil potential for N mineralization (No) of manure compost (CHM, PIM, and COM) treated soils were higher than those of the manure-sawdust compost (CHMS, PIMS, and COMS) treated soils. The No value of PIM applied soil was 15.0 mg 100 $g^{-1}$, which was the highest value among the treatments. The amount of N mineralized in compost applied soils ranged from 8.1% to 11.9% of the total N content in soils and increased with increasing total N content in soils. The organic matter content in compost applied soils were negatively correlated with No value (r = $-0.69^*$). Therefore, our result indicated that determination of N application rate in livestock manure compost applied soil should be based on total nitrogen content better than soil organic matter content.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.25 no.3
• /
• pp.45-54
• /
• 2017

Poultry manure compost (PMC) as the organic fertilizer sources has a high nutrient content such as nitrogen, phosphate and potassium, and its properties been affected by bulking agent. This study was conducted to evaluate properties of mixed organic fertilizer (MOF) containing PMC composting with sawdust and peat moss as bulking agent, and to measure a characteristics of plant growth by their application. The MOF containing 10~30 % PMC had a coincidency with its guideline in Korea. As applied with MOF containing PMC composting with sawdust (PMCS) or MOF containing PMC composting with peat moss (PMCP), dry weight of plant was increased in MOF treatments blending with 10~30 % PMCS or 10~30 % PMCP. In correlation coefficient between blending ratio of PMC in MOFs and plant growth indexes, PMCS was not significantly different, but its PMCP a positive effect (P<0.05). These results indicated that PMC was able to blend about 10~30 % as mixed organic fertilizer source, and its application increased in plant growth.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.25 no.3
• /
• pp.35-43
• /
• 2017

This study was conducted to evaluate effects of Kimchi factory waste (KFW) as bulking agent on physicochemical properties of cow manure (CM) composting and of its application on lettuce growth. Treatments were designed as follows; CM compost [65 % CM + 35 % sawdust (SD); control], KFW 5 % (65 % CM + 30 % SD + 5 % KFW), KFW 10 % (65 % CM + 25 % SD + 10 % KFW) and KFW 15 % (65 % CM + 20 % SD + 15 % KFW). After composting for 25 days, temperature of KFW treatments was lower than that of control. As compared with control, water content of KFW 15 % treatment was low about $5^{\circ}C$, and content of organic matter (O.M.) and nitrogen (N) was higher. pH and O.M./N ratio of KFW treatments or control were unaffected. In comparison with germination index (G.I.), G.I.s of KFW treatments were more than 70 on 25 days and G.I. of control on 35 days. As applied with KFW composts in lettuce, dry weight of KFW 10 % and KFW 15 % were increased by 84 % and 67 %, respectively, than that of control. These results indicated that Kimchi factory waste was possible to use as the compost law materials in livestock manure composting and to replace some sawdust as bulking agent.

• Journal of Korean Society of Forest Science
• /
• v.76 no.2
• /
• pp.119-126
• /
• 1987

This study was carried out to elucidate the desirable PEG molecular weight and it's blending methods which can promote the dimensional stabilization of Corpus controversa, Quercus variabilis and Prunus sargentii. The results may be summarized as follows: 1. PEG polymer loading in woods was affected by specific gravity of wood. And the PEG polymer loading was satisfactory except in Quercus variabilis, which shows the blending method of PEG V was proper. 2. Bulking coefficiency of PEG V was high in Corpus controversa and Prunus sargentii, and it is necessary to paint or coat water-proofing wood preservative: for high bulking coefficiency of Quercus variabilis. 3. In the treatment of PEG V, the antishrink efficiency of Prunus sargentii was 82.59% and that of Quercus variabilis 62.79%. 4. Dimensional stabilization of hardwoods did not have apparant relation with PEG blending method. 5. Judging from results, PEG-400 and PEG-1000 would be enough for dimensional stabilization of hardwood having high specific gravity if other factors are considered well.