• 대한치과보철학회지
• /
• 제28권1호
• /
• pp.137-163
• /
• 1990

The properties of a investment material can be described by the consistency at the slurry state, the setting time, the compressive strength and the thermal expansion during the casting. In this study the effect of the production parameters which are included the ratio of quartz and cristobalite, the content of binder, the water powder ratio and the content and concentration of additives on the Properties of the gypsum-bonded investments has been investigated with help of the consistency test, the vicat needle test, the compressive strength test, the thermal expansion test, x-ray diffraction and DTA thermal differential test. The experimental results showed that the constitution of a investment with W/P ratio of 0.34, 30% of gypsum, 0.8% aluminium sulfate, 2% magnesium sulfate, 0.6% sodium phosphate was adapted for the properties of the KDA Spec. No. 13 type I investment. The important experimental results are summarized as follows. 1. The consistency of the investment decreased with increasing amount of aluminium sulfate and decreasing amount of sodium phosphate. An addition of magnesium sulfate up to 2% an increase of the consistency was shown. But 3% magnesium sulfate in investment showed a decrease of the consistency. The consistency did not vary significantly with a variation of the content of gypsum and cristobalite and the W/P ratio. 2. Aluminium sulfate and the magnesium sulfate promoted the hardening and the aluminium phosphate delayed the hardening. The setting time increased with amount of gypsum. The effect of the matrix on the setting time was insignificant. With the W/P ratio of 0.34 the setting time was 14 min. 3. The compressive strength decreased with the amount of aluminium sulfate up to 0.25% and increased with the amount of aluminium sulfate greater than 3%. The compressive strength decreased as decreasing the amount of magnesium sulfate and gypsum and as increasing the W/P ratio. The effect of the refractory on the compressive strength was also not significant. With the W/P ratio of 0.34 the compressive strength was $34Kg/mm^2$. 4. The 1st thermal expansion was found at the temperature near and the steady state or the contraction stage was found at the temperature between $250^{\circ}C$ and $500^{\circ}C$. After this stage the 2nd thermal expansion took place at the temperature near $500^{\circ}C$. The amount of thermal expansion increased with decreasing the content of magnesium sulfate, aluminium sulfate and gypsum and the W/P ratio. And the amount of thermal expansion increased as the content of sodium phosphate and cristobalite. With the W/P ratio of 0.34 the amount of total expansion was 1.2%.

• 공업화학
• /
• 제7권2호
• /
• pp.299-307
• /
• 1996

$10^{-6}{\sim}10^{-3}mol/{\ell}$ 농도범위에서 PO가 먼저 부가된 sodium poly(oxyethylene(EO), oxyisopropylene(PO)) dodecyl ether sulfates의 표면장력은 EO가 부가된 화합물보다 낮게 나왔다. 그리고 대체적으로 일반적인 음이온성계면활성제보다도 낮게 나왔다. PO가 먼저 부가된 화합물에 대하여 Gibbs' 흡착등온선으로 계산한 흡착능(${\Gamma}=2.2{\times}10^{-10}mol/cm^2$)은 EO가 부가된 화합물보다는 높지만 sodium dodecyl ether sulfate(${\Gamma}=3.2{\times}10^{-10}mol/cm^2$)보다는 낮다. 이러한 현상은 PO가 부가된 화합물의 분자량이 크기 때문으로 사료된다. 기포력, n-hexane과 benzene에 대한 유화력, 돼지기름과 소기름에 대한 세정력 그리고 산화철에 대한 분산성은 PO 화합물이 EO 화합물보다 우수하게 나타났다. 이러한 현상들은 친수성과 소수성 부분이 각각 따로 따로 존재할 때 계면활성이 높음을 의미한다. 수계에서 n-hexane과 benzene에 대한 유화력 측정결과는 n-hexane보다 benzene에 대하여 높게 나왔으며, 불규칙적인 분산특성을 나타내었다.

• 대한치과보철학회지
• /
• 제29권1호
• /
• pp.139-165
• /
• 1991

The properties of a investment material can be described by the consistency at the slurry state, the setting time, the compressive strength and the thermal expansion during the casting. In this study the effect of the production parameters which are included the ratio of quartz and cristobalite, the content of binder, the water powder ratio and the content and concentration of additives on the properties of the gypsum-bonded investments has been investigated with help of the consistency test, the vicat needle test, the compressive strength test, the thermal expansion test, x-ray diffraction and DTA thermal differential test. The experimental results showed that the constitution of a investment with W/P ratio of 0.34, 30% of gypsum, 0.8% aluminium sulfate, 2% magnesium sulfate, 0.6% sodium phosphate was adapted for the properties of the KDA Spec. No. 13 type I investment. The important experimental results are summarized as follows. 1. The consistency of the investment decreased with increasing amount of aluminium sulfate and decreasing amount of sodium phosphate. An addition of magnesium sulfate up to 2% an increase of the consistency was shown. But 3% magnesium sulfate in investment showed a decrease of consistency. The consistency did not vary significantly with a variation of the content of gypsum and cristobalite and the W/P ratio. 2. Aluminium sulfata and the magnesium sulfate promoted the hardening and the aluminium phoshpate delayed the hardening. The setting time increased with amount of gypsum. The effect of the matrix on the setting time was insignificant. With the W/P ratio of 0.34 the setting time was 14 min. 3. The compressive strength decreased with the amount of aluminium sulfate up to 0.25% and increased with the amount of aluminium sulfate greater than 3%. The compressive strength decreased as decreasing the amount of magnesium sulfate and gypsum and as increasing the W/P ratio. The effect fo the refractory on the compressive strength was also not significant. With the W/P ratio of 0.34 the compressive strength was $34Kg/mm^2$. 4. The 1st thermal expansion was found at the temperature near $250^{\circ}C$ and the steady state or the contraction stage was found at the temperature between $250^{\circ}C$ and $500^{\circ}C$. After this stage the 2nd thermal expansion took place at the temperature near $500^{\circ}C$. The amount of thermal expansion increased with decreasing the content of magnesium sulfate, aluminium sulfate and gypsum and the W/P ratio. And the amount of thermal expansion increased as the content of sodium phosphate ad cristobalite. With the W/P ratio of 0.34 the amount of total expansion was 1.2%.

• 한국임상수의학회지
• /
• 제11권1호
• /
• pp.359-368
• /
• 1994

This study was undertaken to evaluate image quality and level of discomfort during examination with various contrast media(meglumine ioxitalamate: Telebrix $30^{\circledR}$ , diatrizoate sodium: Hypaque $50^{\circledR}$, sodium ioxaglate ＋ meglumine ioxaglate: Hexabrix , iopamidol: Iopamiro $300^{\circledR}$ , iodized poppyseed oil: $Lipiodol^{\circledR}$ and barium sulfate: Baritop$^{\circledR}$and various radiographic contrast techniques(eye dropping: group 1, single injection to the superior punctum: group 2 and continuous injection to the superior punctum: group 3) on dacryocystorhinography in dogs. The results were as follows; 1. The Image quality of radiographic contrast technique of continuous Injection of contrast media(group 3) was better than the other techniques. 2. Average scores for dacryocystorhinography quality of sodium ioxaglate ＋ meglumine ioxaglate, iopamidol, barium sulfate, iodized Poppyseed oil, meglumine ioxitalamate and diatrizoats sodium were 3.67${\pm}$0.47, 3.67${\pm}$0.47, 3.50${\pm}$0.50, 3.33${\pm}$0.75, 2.50${\pm}$0.50 and 2.50${\pm}$0.76, respectively in group 3. 3. Diatrizoate sodium produced more discomfort than the other media. It was considered that the best radiographic contrast technique of dacryocystorhinography was continuous injection of contrast media to the superior punctum and sodium ioxaglate + meglumine ioxaglate, iopamidol, iodized Poppyseed oil and barium sulfate were the excellent contrast media for dacryocystorhinography in dogs.

• 대한한의학회지
• /
• 제27권2호
• /
• pp.103-110
• /
• 2006

Objectives : This study was conducted to investigate the effects of ginseng saponins and commercial surfactants such as Triton X-100, sodium deoxycholate, and sodium dodecyl sulfate on the gastric enzyme-catalyzed hydrolysis. Methods : Saponins (a surface-active plant component) from fresh ginseng root were extracted to examine its effect on the gastric enzyme-catalyzed hydrolysis. Commercial surfactants such as Triton X-100, sodium deoxycholate, and sodium dodecyl sulfate were also employed in the hydrolysis system to compare their effects with that of the ginseng saponins. The effects of surfactants on the gastric enzyme-catalyzed hydrolysis were measured by using a spectrophotometer. A spectropolarimeter was used to examine the conformational change of enzymes and substrates by the addition of ginseng saponins into the system. Results : Both the tryptic and the peptic digestion of milk casein or eggalbumin were slightly improved with an increase in the amount of ginseng saponins in the system. Triton X-100 showed an effect similar to that of ginseng saponins, while sodium dodecyl sulfate and sodium deoxycholate diminished the hydrolysis. Circular dichroism spectra of enzymes and substrates was significantly changed by the addition of ginseng saponins into the system. Conclusions : These results show that ginseng saponins affect positively the gastric enzyme-catalyzed hydrolysis, and suggest that the digestion of substrates by gastric enzymes is affected by the change of enzyme conformation by ginseng saponins.

• 한국환경과학회지
• /
• 제5권2호
• /
• pp.203-210
• /
• 1996

To improve coagulation characteristics and to reduce dossage of chemicals in watertreatment, polyaluminium sulfate was manufactured by reaction of polymerization between aluminium sulfate and sodium aluminate. As the results of affirmation and performance test, the yield of product was about 24% from molecular cut on levels by ultrafilteration method. The type of molecular is nearly affirmated as a kind of complex like AIm(OH)n(3m-n)+ from Scanning Electron Microscopy (S.E.M.) and X-ray diffraction test. Since the synthesized polymer was supposed to be quasi, further study for stabilization was required.

• Steel and Composite Structures
• /
• 제29권2호
• /
• pp.201-218
• /
• 2018

In this study, the effects of magnesium sulfate on the mechanical performance and the durability of confined and unconfined geopolymer concrete (GPC) specimens were investigated. The carbon and basalt fiber reinforced polymer (FRP) fabrics with 1-layer and 3-layers were used to evaluate the performances of the specimens under static and cyclic loading in the ambient and magnesium sulfate environments. In addition, the use of FRP materials as a rehabilitation technique was also studied. For the geopolymerization process of GPC specimens, the alkaline activator has selected a mixture of sodium silicate solution ($Na_2SiO_3$) and sodium hydroxide solution (NaOH) with a ratio ($Na_2SiO_3/NaOH$) of 2.5. In addition to GPC specimens, an ordinary concrete (NC) specimens were also produced as a reference specimens and some of the GPC and NC specimens were immersed in 5% magnesium sulfate solutions. The mechanical performance and the durability of the specimens were evaluated by visual appearance, weight change, static and cyclic loading, and failure modes of the specimens under magnesium sulfate and ambient environments. In addition, the microscopic changes of the specimens due to sulfate attack were also assessed by scanning electron microscopy (SEM) to understand the macroscale behavior of the specimens. Results indicated that geopolymer specimens produced with nano-silica and fly ash showed superior performance than the NC specimens in the sulfate environment. In addition, confined specimens with FRP fabrics significantly improved the compressive strength, ductility and durability resistance of the specimens and the improvement was found higher with the increased number of FRP layers. Specimens wrapped with carbon FRP fabrics showed better mechanical performance and durability properties than the specimens wrapped with basalt FRP fabrics. Both FRP materials can be used as a rehabilitation material in the sulfate environment.

• 대한한의학방제학회지
• /
• 제17권2호
• /
• pp.85-98
• /
• 2009

The fruits of Schisandra chinensis and Prunus mume have been traditionally used in the Oriental countries as an astringent against diarrhea and abdominal pain, a protectant for liver disease, an antimicrobial, and a blood tonic. However, little is known about the extract of Schizandrae Fructus and Mume Fructus (SMF-Ex) on dextran-sulfate sodium (DSS)-induced colitis in mice. In this study, we investigated the protective effects of SMF-Ex on DSS-induced colitis in mice. An experimental colitis was induced by daily treatment with 5% DSS. SMF-Ex was orally administrated the single dose (80 mg/kg, body weight/day) for 7 days with one time per day. SMF-Ex reduced significantly clinical sign of DSS-induced colitis, including body weight loss, shorten colon length, increased disease activity index (DAI), and histological colon injury. SMF-Ex also inhibited significantly nitric oxide (NO) and prostaglandine $E_2$ ($PGE_2$) productions in DSS-induced colitis mice. Furthermore, SMF-Ex increased significantly an superoxide anion (SOD), catalase, and glutathione peroxidase (Gpx) activity of the colon tissue in DSS-induced colitis mice. These results suggest that SMF-Ex administration could reduce significantly the clinical signs and inflammatory mediators, and increase antioxidant activity in DSS-induced colitis model mice and is a good candidate for further evaluation as an effective anti-ulcerative agent.

• 대한한방내과학회지
• /
• 제34권2호
• /
• pp.134-146
• /
• 2013

Objectives : Auklandia Lappa (ALE) is one of the herbs used frequently to treat abdominal pain and diarrhea and reported anti-inflammatory activity by suppressing proinflammatory cytokines. This study was designed to investigate whether ALE could show protective activities on experimental colitis induced by dextran sulfate sodium (DSS) models. Methods : Colitis was induced by DSS in Balb/c mice. ALE 10, 30, 100 and 300 mg/kg were orally administered twice a day for 7 days in DSS model. Mice weight was measured daily. Scoring of clinical findings was measured every other day. Colon length, edema, fecal blood and histological damages were assessed at day 7 in DSS model. In histological analysis, we checked cryptal glands, surface epithelium, submucosa, transmural, stroma and scored degree of inflammatory cell damage by modified histological scoring. We also calculated cytokines concentrations including IFN-${\gamma}$, TNF-${\alpha}$, IL-6, IL-$1{\beta}$, IL-17, IL-23, IL-10 and TGF-${\beta}1$ by Biometric Multiplex Cytokine Profiling method. Results : ALE showed the protective effects on DSS-induced experimental colitis. ALE inhibited shortening of colon length and histological damages of colon does-dependently, but it did not inhibit weight loss. ALE also inhibited IFN-${\gamma}$ and IL-6 expression, and upregulated cytokines (IL-10, TGF-${\beta}1$) related to regulatory T cell differentiation and proliferation. Conclusions : The current results demonstrate the clinical utility of ALE in traditional medicine and indicate the possibility of potent drug development of inflammatory bowel diseases from natural products. Further investigations for exact mechanisms will be needed.

• 대한한의학회지
• /
• 제16권1호통권29호
• /
• pp.319-338
• /
• 1995

This article is to investigate the effects of Euphorbia Pekinensis RUPR. on rats with acute renal failure induced by gentamicin sulfate. So this experimental research was focused on measuring (1)the levels of creatinine, blood urea nitrogen, glutamic oxaloacetic transaminase, glutamic pyruvic transaminase, total protein, sodium, potassium, chloride in the serum and (2)the levels of protein, blood, sodium, potassium, chloride, pH, specific gravity and volume in the urine and (3)intake water. The results were summarized as follows. 1. While the levels of creatinine and glutamic oxaloacetic transaminase, glutamic pyruvic transaminase in the serum were significantly increased, the level of BUN in the serum were partially increased and the levels of sodium and potassium in the serum were partially decreased on the Euphorbia Pekinensis $R_{UPR}$. group. 2. While the urine volume was significantly increased, the levels of protein, blood, sodium and chloride in the urine were partially increased and the specific gravity, pH in the urine were partially decreased. According to the above results, it is shown that Euphorbia Pekinensis $R_{UPR}$. without refinning had a diuretic effect on rats with acute renal failure induced by gentamicin sulfate, but aggravated the glomerular filtration rate and tubular reabsorption. So, it is supposed that Euphorbia Pekinensis $R_{UPR}$. without refinning needs to be used carefully on renal disease and futhermore research about the kinds of extracts form is necessary.