• Title/Summary/Keyword: Black powder

Search Result 356, Processing Time 0.031 seconds

Study on characteristic of mycelial culture in ear mushroom (목이의 균사생육 특성에 관한 연구)

  • Yu, Young-Jin;Choi, Kyu-Hwan;Jeong, Jong-Seong;Lee, Gi-Kwon;Choi, So-Ra
    • Journal of Mushroom
    • /
    • v.11 no.1
    • /
    • pp.15-20
    • /
    • 2013
  • This study was performed to obtain the scientific data an artificial culture of ear mushroom(Auricularia auricula). Liquid cultural of Auricularia auricula. mycelium was characterized with respect to temperature, pH, compositions of inorganic, carbon and nitrogen. The its optimum temperature and media pH were at $25^{\circ}C$ and pH 5.0~6.0 on the mycelial growth, respectively. The optimum inorganic compositions and concentration for mycelial growth were $MgSO_4$ 0.05%(w/v) and $KH_2PO_4$ 0.1%(w/v), respectively. The optimum carbon sources and nitrogen sources were black-sugar 2%(w/v) and soybean powder at 0.3~0.5%(w/v) with7 days optimum culture time.

Theory and Practice of Explosive Blasting (화약 발파의 이론과 실제)

  • Ryu, Chang-Ha;Choi, Byung-Hee
    • Explosives and Blasting
    • /
    • v.34 no.4
    • /
    • pp.10-18
    • /
    • 2016
  • Explosive blasting utilizes the energy produced from the explosion of explosive materials. Since the black powder, the first type of explosive, was invented, various types of explosives have been developed until a recent emulsion explosive which is powerful as well as safe in use. The detonators continue to be developed from safety fuse to the recent electronic detonators which allow extremely accurate and flexible control of delay time. However, the good explosives and detonators do not always lead to the good blast results. It entirely depends on the blast engineer. It is necessary to develop the empirical or theoretical models based on the field experience and sound theoretical algorithm. Such models would be very useful for blast design and, furthermore, provide the idea of further technical development. This paper introduces some models used in explosive blasting and attention to be paid for field application.

Analysis of Manganese Content in Frequently Consumed Foods by Koreans (한국인 상용 식품 중 망간 함량 분석)

  • Choi, Mi-Kyeong;Kim, Eun-Young
    • Journal of Nutrition and Health
    • /
    • v.40 no.8
    • /
    • pp.769-778
    • /
    • 2007
  • Using ICP-AES, we analyzed manganese content in 366 foods consumed frequently by Koreans. For the analysis, it was included a total of 366 foods such as 51 kinds of grains, 7 kinds of potatoes and starches, 7 kinds of sugars and sweeteners, 12 kinds of legumes, 11 kinds of nuts and seeds, 68 kinds of vegetables, 7 kinds of mushrooms, 33 kinds of fruits, 13 kinds of meats, 4 kinds of eggs, 48 kinds of fishes and shellfishes, 7 kinds of seaweeds, 16 kinds of milks, 8 kinds of oils and fats, 27 kinds of beverages, 34 kinds of seasonings, 13 kinds of processed foods and others. Among the grains, starches and sugars, manganese content of rice was 0.745 mg/100g. As for legumes, the content of manganese in soybean milk was 0.033 mg/100g and in black beans was 4.075 mg/100g. In nuts and seeds, the content of manganese in gingko nuts was 0.268 mg/100g while that in pine nuts was 8.872 mg/100g. Among the vegetables, manganese contents were 0.061 mg/100g in cherry tomato and 14.017 mg/100g in ginger. In mushrooms, the highest manganese content was displayed in ear mushroom at 10.382 mg/100g. Dried jujube and shrimp were found to be the fruits and fishes with high manganese contents at 2.985 mg/100g and 3.512 mg/100g, respectively. Among dairy foods, oils and beverages, manganese content was the highest in instant coffee powder at 2.577 mg/100g. Seasonings and processed foods posted 0.010 mg/100g in Sagolgomtang, instant soup and 23.846 mg/100g in pepper. In a furture, more various food for manganese content needs to be analyzed and a reliable food database should be compiled from the findings of researches in order to estimate manganese consumption accurately.

Thick Film Resistance Paste for Improving Reliability and TCR Properties of Embedded Resistor Board (내장형 저항 기판의 신뢰성과 TCR 개선을 위한 후막 저항 페이스트에 관한 연구)

  • Lee, S.M.;Yoo, M.J.;Park, S.D.;Kang, N.K.;Nam, S.
    • Journal of the Microelectronics and Packaging Society
    • /
    • v.15 no.1
    • /
    • pp.27-31
    • /
    • 2008
  • Due to the increasing need for miniaturization of electronic device, embedded resistor technology using thick film resistance paste to embed resistors currently mounted on the board thus effectively reducing board size, is being extensively researched. In this research, thick film resistor paste having $0.35{\sim}4k{\Omega}/sq$ range of resistivity were fabricated using mixtures of carbon black and epoxy resin. In order to adjust the TCR (temperature coefficient resistivity), TCR modifiers such as Ni-Cr alloy, $SiO_2$ powder were added and were able to improve on TCR value with $100ppm/^{\circ}C$. Finally embedded resistor board using thick film resistance paste were fabricated. Stable resistivity value and reliability results were achieved.

  • PDF

A Comparative Study of Indigo Dyes and Dyeing in 19th Century Korea and England

  • Kim, Soon-Young
    • Journal of the Korean Society of Clothing and Textiles
    • /
    • v.34 no.12
    • /
    • pp.1933-1946
    • /
    • 2010
  • This paper is a comparative analysis of the $19^{th}$ century practice of indigo dyes and dyeing in Korea and England. From over hundreds species of indigo plants in the world, it was dyer's knotweed and woad that were cultivated in Korea; however, the only indigo plant grown in England was woad. Indigo dye was produced in the form of damp indigo sediment (jeon) in Korea; however, imported indigo (as a main dye) and couched woad (as an additional dye) were indigo dyes used in England. There existed three kinds of indigo vats, the ice vat, ash-water vat, and indigo sediment (jeon) vat, in Korea. The fresh leaves of indigo were used for both the ice vat and ash-water vat. The ice vat was very convenient for preparation, but had a weakness in the inability to produce a very deep shade of blue. The ash-water vat and indigo sediment (jeon) vat were in use for producing a very deep shade of blue. The indigo sediment Goon) vat was employed presumably only by professional dyers. The indigo vat practiced in England was categorized into two types; one was woad-indigo vat, and the other was an indigo powder vat prepared by using imported indigo rock. There was a tendency to adopt different kinds of indigo vats according to the material to be dyed. The woad-indigo vat was employed for the dyeing of wool. A few of chemical vats with imported indigo were adopted, especially for the dyeing of cotton. Indigo dyers in 19th century Korea were differentiated from the rest of the dyers. They managed the growing of indigo plants as well as the production of indigo sediment (jeon). Woad dyers in 19th century England handled woolen cloth as well as worsted and woolen yarn in general. However, they sometimes dyed silk skein as well. They produced several colors such as black, blue, slates, grays, by using both woad and imported indigo.

Electrical and Mechanical Characteristics of Ni-YSZ Tubular Support Fabricated by Extrusion (압출공정에 의해 제조된 Ni-YSZ 원통형 음극 지지체의 특성)

  • Yu, Ji-Haeng;Kim, Young-Woon;Park, Gun-Woo;Seo, Doo-Won;Lee, Shi-Woo;Woo, Sang-Kuk
    • Journal of the Korean Ceramic Society
    • /
    • v.43 no.12 s.295
    • /
    • pp.768-774
    • /
    • 2006
  • The microstructure of Ni-YSZ cermets was controlled with fine and coarse starting powders (NiO and YSZ) to obtain a optimum strong and conductive tubular anode support for SOFCs. Three types of cermets with different microstructures, i.e., coarse Ni-fine YSZ, fine Ni-coarse YSZ, and fine Ni-fine YSZ, were fabricated to investigate their electrical and mechanical properties. The cermets from fine NiO powder showed high electrical conductivity due to the enhanced percolation of Ni particles. The cermet by foe Ni and coarse YSZ showed excellent electrical conductivity (>1000 S/cm) despite its high porosity $(\sim40%)$ but it showed poor mechanical strength due to the lack of percolation by YSZ particles and due to large pores. Thus fine NiO and YSZ powders were used to make strong and conductive Ni-YSZ support tube by extrusion. The microstructure of the anode tube was modified by the amount of polymeric additives and carbon black, a pore former. Ni-YSZ tube (porosity $\sim34%$) with the finer microstructure showed better performance both in electrical conductivity (>1000 S/cm) and fracture strength $(\sim140\;MPa)$. Either flat or circular NiO-YSZ tubes with the length from 20 to 40cm were successfully fabricated with the optimized composition of materials and polymeric additives.

Synthesis of Amorphous Er3+-Yb3+ Co-doped TiO2 and Its Application as a Scattering Layer for Dye-sensitized Solar Cells

  • Han, Chi-Hwan;Lee, Hak-Soo;Lee, Kyung-Won;Han, Sang-Do;Singh, Ishwar
    • Bulletin of the Korean Chemical Society
    • /
    • v.30 no.1
    • /
    • pp.219-223
    • /
    • 2009
  • $TiO_2$ doped with $Er^{3+\;and\;Yb^{3+}$ was used for fabricating a scattering layer and a nano-crystalline $TiO_2$ electrode layer to be used in dye-sensitized solar cells. The material was prepared using a new sol-gel combustion hybrid method with acetylene black as fuel. The $Er^{3+}$-$Yb^{3+}$ co-doped titanium oxide powder synthesized at 700oC had embossed structure morphology with a size between 27 to 54 nm that agglomerated to produce micron size particles, as observed by the scanning electron micrographs. The XRD patterns showed that the $Er^{3+}$-$Yb^{3+}$ co-doped titanium oxide had an amorphous structure, while using the same method without doping $Er^{3+}\;or\;Yb^{3+},\;TiO_2$ was obtained in the crystallite form with thea dominance of rutile phase. Fabricating a bilayer structure consisting of nano-crystalline $TiO_2$ and the synthesized $Er^{3+}$-$Yb^{3+}$ co-doped titanium oxide showed better scattering property, with an overall increase of 15.6% in efficiency of the solar cell with respect to a single nano-crystalline $TiO_2$ layer.

Effect of Conductive Additives in La0.8Sr0.2MnO3 Perovskite Electrodes for Oxygen Reduction and Evolution in Alkaline Solution (알칼리용액에서 La0.8Sr0.2MnO3 페롭스카이트 촉매의 산소환원 및 발생반응에서 도전재의 영향)

  • SHIM, JOONGPYO;LOPEZ, KAREEN J.;YANG, JIN-HYUN;SUN, HO-JUNG;PARK, GYUNGSE;EOM, SEUNGWOOK;LEE, HONG-KI
    • Transactions of the Korean hydrogen and new energy society
    • /
    • v.27 no.3
    • /
    • pp.276-282
    • /
    • 2016
  • The effects of conductive additives in a $La_{0.8}Sr_{0.2}MnO_3$ perovskite bifunctional electrode for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) were investigated in an alkaline solution. Highly porous carbon black (CB) and Ni powder were added to the bifunctional electrodes as conductive additives. The surface morphologies of electrodes containing CB and Ni were observed by scanning electron microscopy (SEM). The current densities for both ORR and OER were changed by the addition of CB. The conductive additive changed physical properties of bifunctional electrodes such as the sheet conductance, gas permeability and contact angle. It was observed that the air permeability of electrode was most effective to enhance the currents for ORR and OER.

Studies on the Utilization of Arkshell 1. Preparation and Quality Stability during Storage of Powdered Dried Arkshell for Instant Soup (피조개의 이용에 관한 연구 1. 피조개 분말수우프의 제조 및 저장중의 품질안정성)

  • Kim, Hee-Yun
    • Journal of Food Hygiene and Safety
    • /
    • v.3 no.4
    • /
    • pp.217-223
    • /
    • 1988
  • For the Effective utilization of the fish resources in coastal regions, investigations on preparation of powdered dried arkshell instant soup., quality stability of the products during storage and utilization as a food material were carried out with arkshell, Anadara broughtonii. Three kinds of powdered instant soup were prespared as 0% table salt(A), 5% table salt (B), 15% table salt(C) and packed with vacuum in laminated film bag. (polyester/nylon: 85${mu}ell$/15${mu}ell$, 18$\times$27cm) Their processing conditions and quality stability during storage at room temperature for 90 days were examined. Powdered instant soup was made by washing raw arkshell to remove visceral, clay, sand and blood, hot air drying(60$\pm$1$^{\circ}C$, 20 hrs) after draining and pulverizing dried arkshell to 35 mesh. Powdered instant soup was made by adding 2% sugar 0% table salt (5% and 15% table salt), 10.5% monosodium glutamate, 0.3% black pepper and 0.3% garlic powder to the pulverized dried arkshell. The condition of moisture and water activity of the products were 5.9-6.9% and 0.42-0.43, respectively. The moisture content s , water activity and pH of the products were showed little change and volatile basic nitrogen of them increased slightly during storage. Thiobarbituric acid value increased up to 60 days of storage and then decreased slightly. In solubility, powdered instant soup were showed no remarkable difference comparing with goods on the market. The color value of th products were showed little change during storage, In sensory evaluation, product B were scored slightly higher, in most cased, in flaver, color. taste and overall acceptability comparing with product A or product C during storage. Judiging form the sensory evaluation, powdered instant soup of 5% table salt (B) were the most desirable, and the quality of the products was stable for 90 days at 20$\pm$3$^{\circ}C$.

  • PDF

The Historical Study of Pheasant Cooking in Korea (우리나라 꿩고기 조리법(調理法)의 역사적(歷史的) 고찰(考察))

  • Kim, Tae-Hong
    • Journal of the Korean Society of Food Culture
    • /
    • v.11 no.1
    • /
    • pp.83-96
    • /
    • 1996
  • The purpose of this paper is to examine the various kinds of recipes of pheasant through classical cookbooks written from 1670 to 1943 which are the basic materials to the meat cooking. The recipes of pheasant are found 39 times in the literature, which can be classified into eleven groups. Chronologically, the recipe of mandu (ravioli) was first appeared, and guk, tang (soup), kui (roasted), jang (salted meat), chim (steamed), po (dried meat), whe (raw meat), gijim (boiled in soy sauce), cho (sparkly heated in soy sauce and sugar), jolim (hard boiled in soy sauce), and jungol (meat with vegetable cooked in pan) followed in the records. Kui was the most popular one with the frequency of 43.6%, which proves that kui is the most suitable one for pheasant among all of recipes. Mandu and guk, tang were 10.2%, chim and po were found with the same rate of 7.7% and the next ones were jang, gijim, cho, and jungol with the rate of 2.6%. The recipes of pheasant were recorded much less than those of beef, chicken, pork, lamb, and dog meat. Particularly, in comparison with chicken belonging to fowls, the frequency of pheasant cooking did not reach even to one third of that. The Korean recipes of pheasant have been independently developed with originality, having nothing to do with the Chinese ones. The recipes of pheasant before the late 1800s have based on the strict recipe principles along with the spirit of art and sincerity, but they were deteriorated to simple and easy ones discarding principles. The main ingredient was the flesh of pheasant and the sub-ingredients such as flour, pinenut, buckwheat powder, and mushroom were included in common. In additon, oil, soy sauce, black pepper, and stone leek were frequently used as main seasonings.

  • PDF