• Current Research on Agriculture and Life Sciences
• /
• 제1권
• /
• pp.55-65
• /
• 1983

본(本) 시험(試驗)은 제사용수(製絲用水)에 대(對)한 몇가지 화학약제(化學藥劑)의 처리(處理)가 견층(繭層) sericin의 용해성(溶解性)에 미치는 영향(影響)을 조사(調査)하였던 바, 견층(繭層) sericin의 용해량(溶解量) 조절(調節)에 참고자료(參考資料)가 될 수 있는 다음과 같은 결과(結果)를 얻었다. 공시(供試) 약제(藥劑) 중(中)에서 견층(繭層) sericin의 용해촉진력(溶解促進力)이 가장 큰 약제(藥劑)는 Sodium Hydroxide(NaOH)였으며, Potassium Hydroxide(KOH) > Sodium Silicate($Na_2SiO_3$) > Sodium Bicarbonate($NaHCO_3$)의 순(順)으로 용해추진력(溶解促進力)이 작았다. 공시(供試) 약제(藥劑) 중(中)에서 견층(繭層) sericin의 용해억제력(溶解抑制力)이 가장 큰 약제(藥劑)는 Form Aldehyde(HGHO)였으며, Ammonium Alum($Al_2(SO_4)_2{\cdot}(NH_4)_2SO_4{\cdot}24H_2O$) > Acetic Acid($CH_3COOH$) > Hydrochloric Acid(HCl)의 순(順)으로 용해억제력(溶解抑制力)이 작았다. 공시(供試) 약제(藥劑) 중(中)에서 견층(繭層) sericin의 용해억제력(溶解抑制力)이 클 것으로 기대(期待)했던 Hydrochloric Acid(HCl)은 $80^{\circ}C$이상(以上)의 고온(高溫)에서는 오히려 견층(繭層) sericin의 용해(鎔解)를 크게 촉진(促進)함을 알 수 있었다.

• 한국식품과학회지
• /
• 제5권1호
• /
• pp.1-5
• /
• 1973

Wet gluten 에 salt 및 소량의 산(酸)을 가하여 상압하(常壓下)에서 $6^{\circ}C$로 열풍건조하여 vital gluten 을 제조하였다. 이때 salt 및 산(酸)은 gluten의 점착성을 저하시켜 표면적을 크게하고 열내성(熱耐性)이 생기게 하여 건조를 쉽게 하였다. 1) Salt 농도는 높을수록 glulen의 건조가 용이하나, quality 는 저하되었다 salt 는 $5{\sim}10%$가 좋을 것같다. 2) Salt 외에 HCI을 0.12%첨가한 결과 건조 시간은 거의 반으로 단축되었고, glulen의 질(質)은 저하되지 않았다. 3) 산(酸)은 hydrochloric, acetic, phosphoric, lactic acid 중(中)에서 hydrochloric acid 건조 시간을 가장 적게 하였으며 질(質)은 별 차이 없으므로 hydrochloric acid 첨가가 가장 좋았다.

• 한국환경보건학회지
• /
• 제46권6호
• /
• pp.694-701
• /
• 2020

Objectives: The main purpose of this study is to evaluate heavy metal concentrations (Cd, As, Hg, Pb, Cr6+), particle size distribution, hydrochloric acid solubility, and parasite eggs in sand in five non-designated sandy beaches in Gyeonggi Province. Methods: The sampling sites are five non-designated Gyeonggi-do sandy beaches located in Ansan and Hwaseong. ICP-OES and UV, a Vibratory Sieve Shaker, and PCM were respectively used to analyze heavy metal concentrations, particle size distribution, and parasite eggs in the sand. Results: Heavy metals were detected within the beach's safety management standards and some of the detected As and Pb before and after beach opening were lower than one-quarter of the average value. In addition, the results of the T-test to confirm the As and Pb concentration changes before and after opening showed a significant difference in some beaches. The composition of sand was 86.53% according to the particle size distribution standard (2.0-0.02 mm), and the hydrochloric acid solubility was the highest at Gubongsolsup (4.9%) and the lowest at Bangameo-li (0.2%). Parasite eggs were undetected in all beach sand before and after opening. Conclusions: The safety of heavy metal concentrations in sandy beaches was secured in the selected five beaches in Gyeonggi Province. However, continuous efforts are required to make Gyeonggi-do's beaches suitable according to the Act on the Use and Management of Beaches.

• 분석과학
• /
• 제14권6호
• /
• pp.530-534
• /
• 2001

Effect of stripping solutions on the Duolite GT-73 chelating resin for ten elements, Ag(I), Al(III), Ca(II), Cd(II), Cu(II), Fe(II), Hg(II), Mn(II), Pb(II), and Zn(II), was investigated. Relation between affinities of the metal ions and solubility products of metal sulfides was studied. The smaller the solubility product of metal sulfideis, the larger the affinitie with the ionsis. The ions which have the solubility products larger than $10^{-23}$ could be effectively desorbed with nitric acid. Complexation with chloride ion enhanced the desorption efficiencies of the ions having moderately strong affinity with the resin. The ions which have very strong affinity by the chelating resin can be desorbed by complextion with thiourea and hydrochloric acid.

• Restorative Dentistry and Endodontics
• /
• 제6권1호
• /
• pp.37-50
• /
• 1980

Scanning Electron Microscopic (SEM) examination on the labial surface of 91 permanent upper incisors were made after etching procedure with phosphoric acid, sulfuric acid, nitric acid, hydro chloric acid, oxalic acid, formic acid, citric acid and zinc phosphate liquid for 2 minutes. Following results were obtained. 1. In the surfaces etched by 10%. 50% phosphoric acid, 50% sulfuric acid, 10%. 30% nitric acid, 10%. 50% oxalic acid, 10%. 30%. 50% formic acid, 30%. 50% citric acid and zinc phosphate liquid, there appeared to be a preferential removal of prism cores, but in the surfaces etched by 10% phosphoric acid, 50% nitric acid, 10%. 30% hydrochloric acid and 30% oxalic acid, the prism peripheries were removed preferentially. 2. According to Silverstone classification on enamel etching pattern the surface treated by zinc phosphate liquid, 30. 50% citric acid, 10%. 30%. 50% formic acid, 10%. 50% oxalic acid, 10%. 30% nitric acid, 50% sulfuric acid and 10%. 50%. phosphoric acid showed Type 1, and etched by 30% oxalic acid, 10%. 30% hydrochloric acid, 50% nitric acid and 10% phosphoric acid showed Type II. Etching of prism cores was by far the most common occurence. The changes produced could be related to intrinsic differences in histology and / or solubility of enamel.

• 한국식품영양과학회지
• /
• 제27권6호
• /
• pp.1110-1116
• /
• 1998

To determine the optimum conditions for the enzymic hydrolysis against wheat gluten of high con centrations (6~14%, w/w, protein), a hydrolysis system combining weak acid pretreatment and enzymic hydrolysis was investigated. Alcalase showed the highest DH(degree of hydrolysis) of the tested proteases. After hydrolysis by alcalase, subsequently peptidases were applied for the better DH of the wheat gluten hydrolyzate. Peptidase NP2 showed the highest DH of the tested peptidases, but flavour zyme was shown for the lowest bitter taste of the resulting hydrolyzate. In order to minimize aggregation or gelling at higher initial substrate concentration during heat treatment, wheat gluten suspension was pretreated with possibly low concentrations of hydrochloric acid at 105oC for 1 hour, and then enzy matically hydrolysed with alcalase and subsequently with flavourzyme. Each required minimum concen tration of hydrochloric acid in the wheat gluten suspension of 6, 8, 10, 12, and 14%(w/w, protein) was 0.10, 0.15, 0.20, 0.225, and 0.275N, respectively. After the subsequent enzymic treatment by alcalase and peptidase NP2 for 24 hrs, the nitrogen solubility in the final wheat gluten hydrolysates was increased to 94.9, 86.4, 85.3, 89.3 and 95.0%, and their amino nitrogen content was increased to 2.87, 5.68, 7.34, 9.71 and 12.50mg/m, respectively.

• 한국염색가공학회지
• /
• 제11권2호
• /
• pp.55-63
• /
• 1999

The purpose of this study was to investigate the purification of chitin and chitosan for textile finishing agent from crab shell. Weight loss rate(removing Ca and protein), degree of deacetylation, solubility and MIC(Minimum growth inhibitory concentration) value of chitosan and molecular weight of the treated crab shell were measured. The results of this study were as follows : 1) Weight loss rate(removing Ca) of crab shell treated with HCI increased with the concentration of HCI and treatment time, but it became constant over 60 min. of treatment time. 2) Weight loss rate(removing protein) of crab shell treated with NaOH(0.5N∼2N) increased with the concentration of NaOH and treatment temperature and time, but it became constant above loot of temperature and over 200 min. of treatment time. 3) Degree of deacetylation of chitin treated with NaOH increased with the concentration of NaOH(40∼60％), but molecular weight decreased and thus MIC value increased. 4) Concentration of acetic acid should be above 0.3％ to dissolve chitosan easily. Solubility for chitosan was the highest with formic acid, and the next was acetic acid, hydrochloric acid, lactic acid and sulfuric acid in order.

• Journal of Pharmaceutical Investigation
• /
• 제15권1호
• /
• pp.8-14
• /
• 1985

Data obtained from X-ray diffractometry, thermal analysis, IR spectroscopy and microscopic observation were used for the identification and characterization of four crystalline modifications of piroxicam. form a was crystallized from sodium hydroxide-hydrochloric acid and from c was obtained by crystallization from toluene. Form b and d was crystallized from methanol under the different temperature conditions. Relative rates of dissolution and solubility of four crystal forms of piroxicam in distilled water were measured.

• 분석과학
• /
• 제12권4호
• /
• pp.306-311
• /
• 1999

몇 가지 용해조건에 따른 견 단백절의 조성 변화를 SDS-polyacrylamide 전기영동법, Gel Permeation Chromatography(GPC)법 및 유리아미노산 분석을 통하여 연구하였다. 분자량의 변화에 있어 염산을 이용한 가수분해법의 경우, SDS-PAGE 방법으로는 분자량의 분포를 확인할 수 없었다. 그러나 2N-HCl, 1N-HCl, 0.5N-HCl (3시간 $110^{\circ}C$)와 중성염($CaCl_2$) 및 중성염-효소로 가수분해시킨 견 피브로인 단백질의 평균 분자량 분포는 GPC법에 의하여 각각 Mw 800, 1,500, 3,700과 46,800, 12,500으로 확인되었다. 또한 용해 조건에 의한 유리아미노산 함량은 염산의 농도가 높을수록, 효소를 사용함으로써 유리아미노산의 조성이 증가함을 알 수 있었다.

• Journal of Pharmaceutical Investigation
• /
• 제22권2호
• /
• pp.105-113
• /
• 1992

To improve the solubility and dissolution rate of trimethoprim (TMP), which is slightly soluble drug, its inclusion complexes were prepared and studied in this experiment. Inclusion complexes of TMP with ${\beta}-cyclodextrin$ and ${\beta}-cyclodextrin$ polymer (CDPS) were prepared according to Fenyvesi method. These were compared with TMP and its physical mixture with CDPS. Water, diluted hydrochloric acid and phosphate buffer solution were used as dissolution media. And accelerated stability test was studied at $50,\;70\;and \;80^{\circ}C$. It was found that solubility and dissolution rate of inclusion complexes were increased in water. Especially, the solubility and dissolution rate of TMP was found to be markedly increased by inclusion complexation with CDPS. In stability test, ${\beta}-cyclodextrin$ inclusion complexes were more or less stable than TMP alone. This tendency was not led in CDPS. Consequently, CDPS was useful in increasing dissolution rate and stability of TMP.