• Title/Summary/Keyword: glacial acid

Search Result 42, Processing Time 0.024 seconds

Chemical Weathering of Glacial Debris of the Barton Peninsula of King George Island, South Shetland Islands, Antarctica: Microtextural Evidences (남극 사우스셰틀란드 킹죠지섬 바톤반도 빙하쇄설물의 화학적 풍화작용: 미조직학적 증거)

    • Journal of the Mineralogical Society of Korea
    • /
    • v.16 no.2
    • /
    • pp.181-189
    • /
    • 2003
  • Diverse microtextures and secondary minerals formed by chemical weathering were observed in the glacial debris of King George Island. Weathering rind was observed in the block of basaltic andesite tuff due to dissolution of calcite producing voids. Eolian volcanic glass altered to mixtrure of allophane-like materials and iron oxyhydroxides at grain edges with relative concentration of Al. Fe, and Ti. Biotite in granodiorite area was transfarmed to vermiculite and interstratified biotite-vermiculite or very rarely to kaolinite and gibbsite. Pyrite in the hydrothermal alteration zone was repalced by iron oxides, resulting in sulfuric acid which locally accelerated alteration of chlorite to expandable clay minerals. Weathering of plagiociase and K-feldspar was negligible. Although glacial debris of the Barton Peninsula has undergone weak chemical weathering with formation of some secondary minerals, massive formation of smectite, abundant in nearby marine sediments, didn't occur.

Scanning Electron Micrographic Study on the Etched Surface of Base Metal Alloys for Dental Restorations (치과용 비귀금속합금의 식각표면에 대한 주사전자현미경적 연구)

  • Chung, Hun-Young;Lee, Sun-Hyung
    • The Journal of Korean Academy of Prosthodontics
    • /
    • v.23 no.1
    • /
    • pp.83-95
    • /
    • 1985
  • The purpose of this study was to evaluate microstructures on the etched surface of 11 base metal alloys for dental restorations and to observe the relationship between the etching pattern and beryllium. For this purpose, the following experiments were done; 11 base metal alloys were etched in (1) 10% $H_2SO_4$, (2) 10% $H_2SO_4$, 9 parts+methanol 1 part (3) Conc. $HNO_3$ 25%+glacial acetic acid 25%+$H_2O$ 50% (4) Conc. $HNO_3$ 5% (5) 2% glacial acetic acid added to Conc. $HNO_3$ 1% solution, with their etching conditions varied. Etched surface of alloys were examined under the scanning electron microscope. Results were as follows; 1. Almost all of Ni-Cr-Be alloys showed gooed etchd surface in $H_2SO_4$, solution, while some of those alloys which contains no beryllium showed good etched surface in $HNO_3$ solution. 2. Main components of etching solution can vary etching pattern of alloys. 3. Gamma prime phase relief, which can be found in all Ni-Cr-Be alloys, can't be found in any alloy that contains no beryllium.

  • PDF

An Etiology Report for Burns Caused by Korean Folk Remedies

  • Hong Sil Joo;Hyun Been Kim
    • Archives of Plastic Surgery
    • /
    • v.50 no.3
    • /
    • pp.305-310
    • /
    • 2023
  • Background In this modern era of science-based medicine, some people still accept folk remedies as an alternative form of medicine. However, misinformation and misuse of folk medicines can result in dangerous complications. Among the possible complications of folk remedy use, this study focused on the clinical characteristics of burns caused by folk remedies. Methods We retrospectively reviewed the clinical records of patients who had been treated for burns caused by folk remedies from May 2015 to April 2022. Data were collected on patients' age and gender, type of folk remedy, reason for using the folk remedy, the severity of the burn, the number of wounds, lesion type, and type of treatment. Results We found 59 patients with burns due to folk remedies. Most were female (76.3%) and ≥ 60 years old (72.9%). The most common type of folk remedy was moxibustion (74.6%), followed by the use of glacial acetic acid (20.3%). The reasons for using folk remedies were arthralgia relief (39%), health improvement (18.6%), and treatment of tinea pedis (11.9%). Most patients had multiple wound sites and had burns that were considered severe, requiring surgical treatment (72.9%). The majority of lesions were on the lower extremity, including the foot. Conclusion This study described the risk of burns caused by folk remedies and the clinical characteristics of the wounds. The results emphasize the need for greater public awareness of the risk of burn injuries when using folk remedies.

Antimicrobial Assessment of Some Heterocyclic Compounds Utilizing Ethyl 1-Aminotetrazole-5-carboxylate (Ethyl 1-Aminotetrazole-5-carboxylate로부터 유도된 헤테로고리 화합물들의 항균 활성 시험)

  • Taha, Mamdouh A. M.;El-Badry, Susan M.
    • Journal of the Korean Chemical Society
    • /
    • v.54 no.4
    • /
    • pp.414-418
    • /
    • 2010
  • Ethyl 1-aminotetrazole-5-carboxylate (1) reacted with hydrazine hydrate to give the corresponding aminohydrazide 2. Cyclization of 2 by carbon disulfide yielded 1,3,4-oxadiazole-5-thiol structure 3. Reaction of 3 with either chloroacetone or ethyl chloroacetate furnished S-acyl 1,3,4-oxadiazole derivatives 4 and 5, respectively. Also compound 3 reacted with hydrazine hydrate afforded 4-amino-1,2,4-triazole-5-thiol derivative 6. 6-Methyl-1,3,4-triazolo[3,4-b]-1,3,4-thiadiazole structure 7 was synthesized by reaction of aminothiol 6 with glacial acetic acid. Diazotization of 1 with sodium nitrite in presence of hydrochloric acid yielding the diazonium salt which on treating with hippuric acid, oxazolone derivative 8 was obtained. Furthermore, tetrazolo[5,1-f]-1,2,4-triazine 9 was constructed via cyclization of aminoester 1 with formamide. Compound 9 reacted with carbon disulfide to furnish 8-thione derivative 10 which reacting with chloroacetone, ethyl chloroacetate, and hydrazine hydrate, the corresponding chemical structures 11, 12, and 13 were synthesized. 1,2,4-Triazolo[4,3-d]tetrazolo[5,1-f]-1,2,4-triazines 14 and 15 were resulted by treating of compound 13 with triethyl orthoformate, and glacial acetic acid, respectively. The structures of the newly synthesized products were elucidated according to elemental analyses and spectroscopic evidences. Some of the representative members of the prepared compounds were screened for antimicrobial activity.

Preparation and Evaluation of Bupivacaine-loaded Microspheres by Solvent Extraction Method

  • Kim, Min-Soo;Hwang, Sung-Joo
    • Proceedings of the PSK Conference
    • /
    • 2003.04a
    • /
    • pp.299.2-300
    • /
    • 2003
  • Various bupivacaine-Ioaded microspheres were prepared with poly (d,l-Iactide) (PLA) by solvent extraction method. The internal solution of polymer(PLA R104) and drug in glacial acetic acid was introduced into the external phase of polyvinylpyrrolidone (PVP K-30) in polyethyleneglycol (PEG), and emulsified to be an oil-in-oil (o/o) emulsion. The o/o emulsion was poured to the buffer solution. (omitted)

  • PDF

Monitoring of preservatives in herbal liquid preparations (액상한약제제의 보존제 모니터링)

  • Jeon, Jong-Sup;Jo, Hyun-Ye;Kim, Bum-Ho;Cho, Sang-Hun;Park, Shin-Hee;Kim, Young-Sug;Yoon, Mi-Hye;Lee, Jeong-Bok
    • Analytical Science and Technology
    • /
    • v.24 no.2
    • /
    • pp.127-134
    • /
    • 2011
  • Quantitative HPLC analysis for the determination of in herbal liquid preparations was improved from the general test method besides the Korean Pharmacopeia. Good chromatographic separation of samples containing parabens, interferences, and other pharmaceutical excipients was effectively achieved by using acetonitrile water (containing 1% glacial acetic acid) mixture (30:70 v/v) as mobile phase. To monitor preservatives (benzoic acid, parabens, sorbic acid, dehydroacetic acid, and their salts) in herbal liquid preparations, a group of 47 samples was divided into two different group: preservative labeled group and unlabeled group. From the results, the contents of preservatives in 31 samples of preservative labeled group fell under KFDA regulations, and the contents of dehydroacetic acid in 6 samples of preservative labeled group were not followed by KFDA regulations. Preservatives were detected in 3 samples out of 10 samples in preservative unlabeled group.

Acetate-Promoted Aldol-Type Reaction: Scope and Reactivity of Acetates and Aldehydes

  • Kim, Dong-Hyeon;Rahman, A. F. M. Motiur;Jeong, Byeong-Seon;Lee, Eung-Seok;Jahng, Yurng-dong
    • Bulletin of the Korean Chemical Society
    • /
    • v.30 no.4
    • /
    • pp.797-802
    • /
    • 2009
  • Potential of acetates and related compounds in glacial acetic acid as a catalyst for aldol-type condensation reactions was examined. Reactions of cycloalkanones or selected heteroaromatics with aldehydes in presence of 10 mol% of various acetates in acetic acid afforded ${\alpha},{\alpha}$'-bis(substituted-benzylidene)cycloalkanones and substituted-benzylidene-mackinazolinones, respectively, in good yields. Among the compounds tested, ammonium acetate is the best and effective especially towards the reactions of mackinazolinone and aliphatic aldehydes to afford 6-alkylidenemackinazolinones.

Effects of Chitosan on Production and Rot Control of Soybean Sprouts

  • Lee, Young-Sang;Kang, Chang-Sung;Lee, Yong-Sun
    • KOREAN JOURNAL OF CROP SCIENCE
    • /
    • v.44 no.4
    • /
    • pp.368-372
    • /
    • 1999
  • The practicality of utilizing chitosan as a natural antimicrobial compound to reduce soybean sprout rot was tested. Domestic and imported soybean seeds were soaked for 6 hours in solutions containing different levels of chitosan and acetic acid (glacial), and cultured at $25^{\circ}C$ for 6 days. In case of domestic seeds, soaking with 1,000ppm chitosan increased germination percentage, hypocotyl thickness, total length, and fresh weight of sprouts by 4%, 5%, 2%, and 1%, respectively. The total sprout yield was increased by chitosan in a concentration-dependent manner in that 1,000ppm chitosan resulted in 8% increment of total yield (7.47kg sprouts/kg seed). Chitosan significantly reduced sprout rot percentage to 7.0% compared to control (13.8%), and consequently enhanced marketable sprout yield by 39%. Compared to domestic seeds, the imported soybean seeds exhibited very low germination percentage regardless of chitosan treatments. Chitosan, nevertheless, consistently induced yield increment and rot decrement in imported soybean sprouts. Although 100ppm acetic acid was effective in reducing sprout rot percentage down to 11.8%, its yield-increasing effects were not as prominent as chitosan. In conclusion, soaking soybean seeds with chitosan seems to be a practical method to enhance the efficiency of soybean sprout production.

  • PDF

Influence of Heating, Cooling and Acidity on the Permeability of the Rabbit Erythrocyte Membrane (고온, 한냉 및 산도가 토끼 적혈구막 투과성에 미치는 영향)

  • Lee, D.S.;Shin, H.S.;Hwang, E.R.;Choi, D.K.
    • The Korean Journal of Physiology
    • /
    • v.1 no.2
    • /
    • pp.151-156
    • /
    • 1967
  • Outward movement of hemoglobin and $K^+$ ion across rabbit erythrocyte membrane after heating, cooling and in acid medium was studied. One milliliter of rabbit blood was centrifuged and packed red cells were obtained. Packed red cells were resuspended by addition of 4 ml of 0.9% NaCl solution and were subjected to heating $(57^{\circ}C\;for\;5\;minutes)$ or cooling $(-4^{\circ}C{\sim}-8^{\circ}C\;of\;-10^{\circ}C{\sim}-11^{\circ}C\;for\;10\;minutes) $. For acid medium experiment packed ref cells were resuspended by addition of 4 ml of acid medium of PH 4.5 consisting of 0.01% glacial acetic acid in 0.85% NaCl solution and kept standing for 10 minutes. All red cell suspensions were centrifuged again and packed red cells were separated. This packed red cells were again suspended in 4 ml of NaCl solution of 0.8%, 0.7%, 0.6%, and 0.5% concentration respectively and kept standing for 20 minutes. The concentration of hemoglobin and $K^+$ in the supernatant of the above red cell suspensions were measured and the following results were obtained. 1. Outward movement of hemoglobin and $K^+$ was greatest in red cells subjected to heating. The movement paralled to the osmolal concentration gradient between extra- and intra-cellular phase of red cells. 2. In acid medium the outflux of hemoglobin and $K^+$ increased as compared to the control. 3. In red cells subjected to the cold of $-10^{\circ}C{\sim}-11^{\circ}C$ the outflux of hemoglobin and $K^+$ increased. Whereas in the environment of $-4^{\circ}C{\sim}-8^{\circ}C$ there was no change in the outflux of $K^+$. The he-moglobin outflux showed rather a decreased as compared to tile control.

  • PDF

Antioxidant Activity of Vinegars Commercially Available in Korean Markets (국내 시판되는 식초의 항산화 활성)

  • Lee, Seon-Mi;Choi, Youngmin;Kim, Youngwha;Kim, Dae-Jung;Lee, Junsoo
    • Food Engineering Progress
    • /
    • v.13 no.3
    • /
    • pp.221-225
    • /
    • 2009
  • The aim of this study was to determine the antioxidant compounds (polyphenolics and flavonoids) and to evaluate antioxidant activities using 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging activity and reducing power in 19 vinegar samples. In general, antioxidant activities and antixoidant compounds in drinking vinegars were higher than those in seasoning vinegars. The highest polyphenolic content was found in balsamic vinegar (372.53 mg/100 mL) and also the highest flavonoid contents was in balsamic vinegar (114.40 mg/100 mL). Organic acid content in glacial acetic acid among 19 samples was found in highest amount. There was no relationships between antioxidant compounds/activities and organic acid content in vinegar samples. Therefore, it is assumed that antioxidant activity of vinegars is due to the polyphenolic and/or flavonoid contents of the vinegar samples.