• Korean Journal of Soil Science and Fertilizer
• /
• v.45 no.2
• /
• pp.209-214
• /
• 2012

This experiment was carried out to investigate the replaceability of chemical fertilizer by SCB liquid fertilizer (SCB) in pear orchard for 5 years. The effects on the mineral content of leaf, fruit quality, yield and soil chemical properties are as follows: The mineral content of leaf showed no difference between the treatments; two SCB liquid fertilizer treatments based on the N (SCB-N) and K (SCB-K) content, and control (chemical fertilizer application). There were no significant differences in yield, titratable acidity and weight of the fruit although the figure of fruit weight was high in SCB-N treatment. Soluble solids content was higher in the SCB treatments than the control. Soil chemical properties such as the content of soil organic matter, available soil phosphate and exchangeable cation were not different, although soil pH was higher in SCB treatments. In conclusion, it is suggest that the use of chemical fertilizer in pear orchard could be replaced by the application of SCB liquid fertilizer because of the same effect on the growth of pear tree and soil chemical properties.

• Journal of Food Hygiene and Safety
• /
• v.31 no.4
• /
• pp.227-249
• /
• 2016

Arsenic and its compounds vary in their toxicity according to the chemical forms. Inorganic arsenic is more toxic and known as carcinogen. The provisional tolerable weekly intake (PTWI) of $15{\mu}g/kg$ b.w./week established by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) has been withdrawn, while the EFSA panel suggested $BMDL_{0.1}$ $0.3{\sim}8{\mu}g/kg\;b.w./day$ for cancers of the lung, skin and bladder, as well as skin lesions. Rice, seaweed and beverages are known as food being rich in inorganic arsenic. As(III) is the major form of inorganic arsenic in rice and anaerobic paddy soils, while most of inorganic arsenic in seaweed is present as As(V). The inorganic arsenic in food was extracted with solvent such as distilled water, methanol, nitric acid and so on in heat-assisted condition or at room temperature. Arsenic speciation analysis was based on ion-exchange chromatography and high-performance liquid chromatography equipped with atomic absorption spectrometry and inductively coupled plasma mass spectrometry. However, there has been no harmonized and standardized method for inorganic arsenic analysis internationally. The inorganic arsenic exposure from food has been estimated to range of $0.13{\sim}0.7{\mu}g/kg$ bw/day for European, American and Australian, and $0.22{\sim}5{\mu}g/kg$ bw/day for Asian. The maximum level (ML) for inorganic arsenic in food has established by EU, China, Australia and New Zealand, but are under review in Korea. Until now, several studies have conducted for reduction of inorganic arsenic in food. Inorganic arsenic levels in rice and seaweed were reduced by more polishing and washing, boiling and washing, respectively. Further research for international harmonization of analytical method, monitoring and risk assessment will be needed to strengthen safety management of inorganic arsenic of foods in Korea.

• Clean Technology
• /
• v.27 no.2
• /
• pp.115-123
• /
• 2021

This study demonstrates a new method for the synthesis of organic-inorganic hybrid particles composed of an inorganic silica shell and organic core particles. The organic core particles are prepared with a uniform size using droplet-based microfluidic technology. In the process of preparing the organic core particles, uniform droplets are generated by independently controlling the flow rates of the dispersed phase containing photocurable resins and the continuous phase. After the generation of droplets in a microfluidic device, the droplets are photo-polymerized as particles by ultraviolet irradiation at the ends of microfluidic channels. The core particle is coated with a nano complex composed of polyallylamine hydrochloride (PAH) and phosphate ion (Pi) through strong non-covalent interactions such as hydrogen bonding and electrostatic interaction under optimized pH conditions. The polyamine nano complex rapidly induces the condensation reaction of silicic acid through the arranged amine groups of the main chain of PAH. Therefore, this method enabled the preparation of organic-inorganic hybrid particles coated with inorganic silica nanoparticles on the organic core. Finally, we demonstrated the synthesis of organic-inorganic hybrid particles in a short time under ambient and environmentally friendly conditions, and this is applicable to the production of organic-inorganic hybrid particles having various sizes and shapes.

• Korean Chemical Engineering Research
• /
• v.62 no.3
• /
• pp.233-237
• /
• 2024

This study is about the fabrication of a flexible electrode based on PAN-based carbon fibers tow using organic/inorganic nanocomposite and its application of non-enzymatic sensor. The organic/inorganic nanocomposite was composed of the conductive polymer polyaniline (PANI) and the metal oxide CuO. And glucose was used as the target of the electrochemical sensor. Commercialized CFTs were pretreated through heat treatment for desizing and electrochemical oxidation for activation. This nanocomposite was sequentially synthesized on the pretreated CFT surface using electrochemical polymerization and electrochemical deposition. Finally, the CFT/PANI/CuO NPs electrode was obtained. The electrochemical properties and sensing performance of the CFT/PANI/CuO NPs electrode were analyzed using chronoamperometry (CA), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). The sensitivity of the CFT/PANI/CuO NPs electrode was about 8.352 mA/mM (in a linear range of 0.445~6.674 mM) and 3.369 mA/mM (in a linear range of 6.674~50 mM), respectively. So, the CFT/PANI/CuO NPs electrode exhibited the enhanced sensing performances due to unique properties such as small peak potential separation, low electron transfer resistance, and large specific surface area.

• Korean Chemical Engineering Research
• /
• v.44 no.3
• /
• pp.254-258
• /
• 2006

Zeolites with excellent adsorption capacity of volatile organic compounds were attached onto inorganic fibers which were the raw materials of honeycomb-type adsorbers. The amounts of zeolite particles attached onto the fibers considerably increased by treating them with hydrochloric acid, sulfuric acid, or hydrofluoric acid. Various functional groups such as chloropropyl, aminopropyl and epoxy groups of silane compounds, and amine groups of polyethylenimine were employed as covalent linkage materials between the fibers and zeolite particles. The state of the fibers coated with zeolite particles was examined by scanning electron microscopy, and the amounts of zeolite particles bound to the fibers were estimated from their BET surface areas. The largest amount was obtained when polyethylenimine was employed as a linkage material. Polyethylenimine was the most effective for attaching zeolite particles onto the inorganic fibers among various linkers employed.

• 발명특허
• /
• v.31 no.10 s.364
• /
• pp.52-55
• /
• 2006

• 발명특허
• /
• v.31 no.8 s.362
• /
• pp.78-80
• /
• 2006

• 발명특허
• /
• v.31 no.9 s.363
• /
• pp.50-52
• /
• 2006

• Defense and Technology
• /
• no.12 s.24
• /
• pp.6-17
• /
• 1980

• Proceedings of the Membrane Society of Korea Conference
• /
• 1996.10a
• /
• pp.55-57
• /
• 1996

다공성 무기막은 높은투과도와 뛰어난 내열.내화학성, 그리고 경제성 때문에 기존의 PSA공정이나 증류와 같은 고에너지 분리공정을 대체하는 공정으로 각광을 받고 있다. 무기재료막의 제조하는 방법으로 주로 알콕사이드를 사용하는 솔-젤법(1)과 금속(2) 또는 기상반응(3)을 이용하는 화학증착법이 사용된다. 또한 고온에서 수소를 연속적으로 분리하여 화학평형에 기인한 한계를 극복하여 높은 수율을 얻고자하는 막반응기에 관한 연구가 활발히 진행되고 있다. 본 연구에서는 $\alpha$-알루미나 지지체의 미세한 다공성 구조 내부에서 TEOS(Tetraethylorthosilicate)와 산성의 알코올-물 혼합물을 확산시켜 실리카 솔을 생성시킴과 동시에 젤화시켜 기공의 크기를 감소시켜 막을 제조하였다. 이렇게 제조된 막은 높은 투과도와 낮은 수소선택도(selectivity=3-4)를 보였고, 두번째 단계로 silica sol을 제조하여 진공 하에서 dip-coating을 행하였다. 이렇게 2단계로 기공 구조를 개선시킨 실리카 막은 저압에서 상대적으로 높은 수소의 분리도(selectivity=5-7)를 보였으며 여전히 높은 투과도를 갖는다.