• Title/Summary/Keyword: cure time

Search Result 482, Processing Time 0.029 seconds

Mechanical and Thermal Properties of Cured Specimen or DGEBA/DDM System (DGEBA/DDM계 에폭시수지 경화 시험편의 기계적 및 열적특성)

  • Kim, Kong-Soo;Park, Jun-Ha;Kim, Ki-Wun;Kim, Young-Jun
    • Elastomers and Composites
    • /
    • v.33 no.1
    • /
    • pp.10-16
    • /
    • 1998
  • In DGEBA/DDM system, the curing specimen are many curing factors which can affect on thermal and mechanical properties. This study was performed to prove the effect on curing specimen prepared by changing of the curing factors which are curing time and temperature of DGEBA/DDM system. As a result on thermal and mechanical properties, flexural strength, modulus and glass transition temperature (Tg) were increased with curing time and temperature were increased. It was found that the optimum curing condition of DGEBA/DDM system cure at $150^{\circ}C$ for 3hrs at equivalent ratio of 1/1.

  • PDF

Studies on the Chemical Treatment of Silica for Synthetic Rubber Reinforcement (II) -Silica Treatment by LBR-MDI- (합성(合成)고무 보강제(補强劑) Silica의 화학처리(化學處理)에 관(關)한 연구(硏究) (II) -MDI 처리(處理) Silica의 LBR처리(處理)-)

  • Jin, Je-Yong;Kim, Hong-Seon;Choi, Sei-Young
    • Elastomers and Composites
    • /
    • v.30 no.3
    • /
    • pp.207-217
    • /
    • 1995
  • The reinforcement of Inorganic filler silica treated with LBR-MDI In SBR vulcanizates were Investigated. The inorganic filler silica treated with MDI on unmodified surface and that of silica treated by MDI was retreated with LBR. The charateristics of vulcanization, physical properties, surface properites and dynamic properties were investigated after mixing those silica with SBR and unmodified silica with SBR. Rheometric studies of the vulcanization showed that S-series has fast scorch $time(t_{10})$ and an optimum cure $time(t_{90})$ in the SBR compounds. And it was turned out that SBR vulcanizates compounded with LBR treated silica was better than any other componnds in hardness, tensile strenght, 100 300% modula and elongation. We could confirm that urea bonding is formed from IR spectrum. We concluded that L-series shows the best reinforcement effect in SBR vulcanizates.

  • PDF

Effect of cobalt ferrite on curing and electromagnetic properties of natural rubber composites

  • Anuchit Hunyek;Chitnarong Sirisathitkul
    • Advances in materials Research
    • /
    • v.12 no.1
    • /
    • pp.1-13
    • /
    • 2023
  • The combination of cobalt ferrite and natural rubber has a potential to enhance the functional properties of rubber ferrite composites available on the market. In this study, cobalt ferrite was synthesized by the sol-gel method with tapioca starch as a cheating agent and then incorporated into natural rubber using an internal mixer. The curing characteristics, magnetic hysteresis, complex permeability, and permittivity of the rubber ferrite composites were studied as a function of the loading from 0 to 25 phr. The cure time and scorch time tended to reduce with the addition of non-reinforced cobalt ferrite fillers. The remanent and saturation magnetizations were linearly proportional to the cobalt ferrite loading, consistent with the rule of mixture. On the other hand, the increase in cobalt ferrite loading from 5 to 25 phr slightly affected the coercive field and the complex permeability. Using the maximum loading of 25 phr, both real and imaginary parts of the permittivity were significantly raised and reduced with the frequency in the 10-300 MHz range.

Review of Clinical Studies of Oral Herbal Medicine Treatment for Pediatric Chickenpox using CNKI Database - Focused on Chinese Randomized Controlled Trials after 2000s - (CNKI로 검색한 소아 수두의 한약 내복 치료에 대한 임상연구 동향 - 2000년대 이후 RCT 연구를 중심으로-)

  • Choi, Jung Yoon;Kim, Jang Hyun;Min, Sang Yeon
    • The Journal of Pediatrics of Korean Medicine
    • /
    • v.34 no.3
    • /
    • pp.18-36
    • /
    • 2020
  • Objectives The purpose of this study is to analyze Chinese randomized controlled trials (RCTs), and to evaluate the effectiveness and safety of the oral herbal medicine treatment for pediatric chickenpox. Methods We searched RCTs after 2000s from the China National Knowledge Infrastructure (CNKI). Afterwards, the year of publication, demographic information, duration of chickenpox, intervention, treatment duration, outcome measure, results and adverse events were investigated and analyzed for this study. Results 21 RCTs out of 219 studies were collected and analyzed. Although each composition of the herbal medicine was different, they have common ingredients such as 清熱解毒, 散結消腫, 疏散風熱, 涼血解毒, 解表散風 in order to make efficacy of 清熱解毒, 散結消腫, 疏散風熱, 涼血解毒, 解表散風. The oral herbal medicine showed better efficacy and safety to improve clinical symptoms such as total efficacy, cure rate, antipyretic time, antipruritic time, scab time, anti-rash time, hospitalization period and herpes recovery time compared to the western medicine treatment. Conclusions These results show that the oral herbal medicine treatment on chickenpox in children may be more effective in reducing of clinical symptoms compared to the western medicine treatment.

A Study on Compliance of Hypertensive Workers at a Department Store in Seoul (서울 시내 한 백화점 근로자의 고혈압 치료 순응도에 관한 연구)

  • Jee, Ju-Ok
    • Korean Journal of Occupational Health Nursing
    • /
    • v.12 no.1
    • /
    • pp.19-30
    • /
    • 2003
  • Increasing occupational cerebrovascular & cardiovascular disease, it becomes the most serious problem in the occupational health management. Hypertension is the most important risk factor of cerebrovascular & cardiovascular disease. Although treatment for hypertension has the priority, hypertension has not been managed systematically at the worksite. The objectives of this study were to investigate the actual situation of its treatment, figure out what factors can affect compliance for hypertension treatment and analyze the relations between compliance and employment status. Subjects were 28 workers who have been diagnosed as hypertension at periodic health examination, 20 workers who have been managed for hypertension at dispensary and 22 workers who were diagnosed during the study periods. The results of the study were as follows; 1. More women have been hired as part time workers and had lower education background and income than the full time workers. 2. Among the factors that have been known to affect the treatment compliance, part time workers had less supports from the company than full time workers. 3. We got the comparison of difference between compliance and variables that the factor grade of cure promotion and average ages are high in high compliance. In conclusion there were not the difference of compliance by employment status. But it was hard to rule out the selection vias because the sample size was so small. So it seems difficult to generalized the conclusion that employment status doesn't affect the treatment compliance.

  • PDF

The Effect of Geukhachukeutang on Intravascula Coagulation and Contusion Blood Stasis in the Rat (혈전(血栓)과 타박성어혈(打撲性瘀血)에 대(對)한 격하축어탕(膈下逐瘀湯)이 미치는 영향(影響))

  • Park, Sung-Whoe;Kim, June-Ki;Park, Weon-Hwan;Choi, Dal-Young;Moon, Jun-Jeun
    • The Journal of Dong Guk Oriental Medicine
    • /
    • v.2 no.1
    • /
    • pp.155-166
    • /
    • 1993
  • Geukhachukeutang is used to cure blood stasis in Oriental Medicine. In order to investigate medical value on intravascula coagulation and contusion blood stasis, the effect of Platelet number, Fibrinogen quantity, Prothrombin time, FOP density, Paw edema increasing rate after prescribing Geukhachukeutang concentration liquid orally were observed. The obtained results are summerized as follows ; 1. Platelet number and Fibrinogen quantity are significantly increased, and Prothrombin time and FOP density are significantly decreased by Geukhachukeutang after inducing intravascula coagulation. 2. Platelet number and Fibrinogen quantity are not significantly increased, and Prothrombin time is not significantly decreased either, by Geukhachukeutang after inducing contusion blood stasis but Paw edema increasing rate is remarkablely decreased in three or four hours of the groups of prescribing. According to the above results, Geukhachukeutang will be used for contusion blood stasis and Intravascula coagulation effectively owing to being accepted as a favorable operation on Platelet number, Fibrinogen quantity, Prothrombin time, FDP density and Paw edema increasing rate.

  • PDF

Treatment test for bovine mastitis by the determination of ATP based on firefly bioluminescence (Bioluminescence 반응에 의한 ATP측정을 이용한 젖소 유방염 치료에 관한 연구)

  • Kim, Tae-jong;Kim, Jong-bae;Lee, Seong-bae;Jeon, Young-soo
    • Korean Journal of Veterinary Research
    • /
    • v.29 no.3
    • /
    • pp.393-405
    • /
    • 1989
  • This study was carried out to treatment test for bovine mastitis by the determination of adenosine triphosphate (ATP) based on firefly bioluminescence. The results obtained are followed; 1. In the susceptibility test, cephalothin which looks the most effective were sensitive to Staphylococcus sp. (72.3%), Micrococcus sp. (84.2%), Streptococcus sp. (72.7%) and Gram positive bacilli (72.7%), Gram negative bacilli were sensitive to gentamicin (92.3%) and Yeast-like-fungi was the most sensitive to clotrimazole, and nystatin in order. 2. When the number of bacteria, such as Staphylococcus aureus, Candida tropicalis isolated from the mastitis milk were counted by conventional agar plating technique, and compared with the concentration of bacterial ATP, it gave a good linear relationship. The content of ATP per Staphylococcus aureus, cell was 3.1fM and Candida tropicalis showed the high level of A TP (90fM). 3. The ATP assay was applied to the determination of minimal inhibitory concentration (MIC) of various antibiotics. When Staphylococcus aureus was incubated in the presence of different concentration of tetracycline, erythromycin, kanamycin and streptomycin sulfate and the growth was monitored by the conventional agar plating technique and ATP assay, both methods shown the same results that they were 1mcg/ml, 2mcg/ml, 6.25mcg/ml and 8mcg/ml, respectively. 4. For the determination of susceptibility of sensitive and resistant Staphylococcus au reus isolated for the milk with mastitis to tetracycline, erythromycin kanamycin and streptomycin sulfate, the minimum time required for the test was determined by the assay of ATP every 30 minutes during incubation of 3 hours at $37^{\circ}C$. ATP concentration time curve calculated on both resistant and sensitive strains incubated 3 hours as the optimum time for the determination of susceptibilities of various antibiotics exemed. The ATP concentration of each test broth (antibiotic containing), expressed as a percentage of its own control brith (antibioticfree) indicated values of 30% to be indicative of each antibiotic sensitivity. Single time point ATP assay carried out on the various sensitive and resistant of Staphylococcus aureus to antibiotics examined after 3 hours at $37^{\circ}C$ correlated exactly with disc diffusion and MIC. 5. In the cure of intramammary treatment of bovine mastitis in lactating quarters, the cure rate of Staphylococcal mastitis showed to cephalexin (80%), cloxacillin and gentamicin (70%), ampicillin and oxytetracycline (60%), and Streptococcal mastitis showed to cephalexin (85%), penicillin (80%), cloxacillin and oxytetracycline (75%), and ampicillin (70%), but intramammary antimycotic drug (clotrimazol) were only a little effect about fungal mastitis.

  • PDF

EFFECT OF SOFT-START CURING ON THE CONTRACTION STRESS OF COMPOSITE RESIN RESTORATION POLYMERIZED WITH LED AND PLASMA CURING UNIT (LED와 플라즈마 광원의 완속기시 광중합 방식이 복합레진의 수축응력에 미치는 영향)

  • Chung, Yang-Seok;Lee, Nan-Young;Lee, Sang-Ho
    • Journal of the korean academy of Pediatric Dentistry
    • /
    • v.34 no.4
    • /
    • pp.623-631
    • /
    • 2007
  • Effect of Soft-start curing on the contraction stress of composite resin restoration polymerized with LED and plasma curing unit The purpose of this study was to evaluate the influence of soft-start light curing on contraction stress and hardness of composite resin. Composite resin (Filtek $Z-250^{TM}$, 3M ESPE, USA) was cured using the one-step continuous curing method with three difference light sources ; conventional halogen light ($XL3000^{TM}$, 3M ESPE, USA) cure for 40 seconds at $400 mw/cm^2$, LED light (Elipar Freelight $2^{TM}$, 3M-ESPE, USA) cure for 20 seconds at $800\;mW/cm^2$ a and plasma arc light ($Flipo^{TM}$, LOKKI, France) cure for 12 seconds at $1300 mW/cm^2$. For the soft-start curing method ; LED light (Elipar Freelight $2^{TM}$, 3M-ESPE, USA) cure exponential increase with 5 seconds followed by 17 seconds at $800\;mW/cm^2$ and plasma arc light ($Flipo^{TM}$, LOKKI, France) cure 2 seconds light exposure at $650\;mW/cm^2$ followed by 11 seconds at $1300\;mW/cm^2$. The strain guage method was used for determination of polymerization contraction. Measurements were recorded at each 2 second for the total of 800 seconds including the periods of light application. Obtained data were analyzed statically using Repeated measures ANOVA, One way ANOVA, and Tukey test. The results of present study can be summarized as follows: 1. Composite resin restoration showed transient expansion just after irradiation of curing light. Contraction stress was increased rapidly at the early phase of polymerization and reduced slowly as time elapsed (P<0.05). 2. Contraction stress was not revealed significant difference between Halogen curing light groups and LED and Plasma Light curing with soft-start group (P>0.05). 3. LED and Plasma Light curing with soft-start showed lower contraction stress than the one-step continuous light curing (P<0.05).

  • PDF

Long Time Efficacy and Safety of Microvascular Decompression Combined with Internal Neurolysis for Recurrent Trigeminal Neuralgia

  • Zheng, Wenhao;Dong, Xiaoqiao;Wang, Din;Hu, Qiang;Du, Quan
    • Journal of Korean Neurosurgical Society
    • /
    • v.64 no.6
    • /
    • pp.966-974
    • /
    • 2021
  • Objective : To explore the clinical efficacy and safety of microvascular decompression (MVD) combined with internal neurolysis (IN) in the treatment of recurrent trigeminal neuralgia (TN) after MVD. Methods : Sixty-four patients with recurrent TN admitted to the hospital from January 2014 to December 2017 were divided into two groups according to the surgical method. Twenty-nine patients, admitted from January 2014 to December 2015, were treated with MVD alone, whereas 35 admitted from January 2016 to December 2017 were treated with MVD+IN. The postoperative efficacy, complications, and pain recurrence rate of the two groups were analyzed. Results : The efficacy of the MVD+IN and MVD groups were 88.6% and 86.2%, and the cure rates were 77.1% and 65.5% respectively. There was no statistically significant difference between the two groups (p>0.05). The cure rate (83.3%) of patients in the MVD+IN group, who were only found thickened arachnoid adhesions during the operation that could not be fully released, was significantly higher than that of the MVD group (30.0%) (p<0.05), while the efficacy (91.7% vs. 70%) of the two groups was not statistically different (p>0.05). For patients whose arachnoid adhesions were completely released, there had no significant difference (p>0.05) in the efficacy (87% vs. 94.7%) and recurrence rate (5.0% vs. 11.1%). The incidence of postoperative facial numbness (88.6%) in the MVD+IN group was higher than that in the MVD group (10.3%) (p<0.01). The long-term incidence of facial numbness was not statistically significant (p>0.05). In the 18-36 months follow-up, the recurrence rate of patients in the MVD+IN group (9.7%) and in the MVD group (16%) were not statistically different (p>0.05). Conclusion : A retrospective comparison of patients with recurrent TN showed that both MVD and MVD combined with IN can effectively treat recurrent TN. Compared with MVD alone, MVD combined with IN can effectively improve the pain cure rate of patients with recurrent TN who have only severe arachnoid adhesions. The combination does not increase the incidence of long-term facial numbness and other complications.

Studies on Cure Behaviors and Rheological and Mechanical Properties of Epoxy/Polyurethane Blend System initiated by Latent Thermal Catalyst (열잠재성 촉매에 의한 에폭시/폴리우레탄 블랜드계의 경화거동, 유변학적 및 기계적 물성에 관한 연구)

  • Gang, Jun-Gil;Gwon, Su-Han;Park, Su-Jin
    • Journal of the Korean Chemical Society
    • /
    • v.46 no.3
    • /
    • pp.233-240
    • /
    • 2002
  • In this work, the cure kinetics and rheological and mechanical properties of diglycidylether of bispheonol A (DGEBA, EP)/polyurethane (PU) blends were investigated. The 1 wt% N-benzylpyrazinium hexafluoroantiminate (BPH) was used as a latent thermal catalyst. Latent properties were performed by measurement of the conversion as a function of reaction temperature using DSC. And the rheological properties of the blend systems were investigated under isothermal conditions using a rheometer. Crosslinking activating energies (Ec) were also determined from the Arrhenius equation based on gel time and curing temperature. The impact strengths were measured as mechanical properties of the casting specimens. The BPH in the blend systems could be an excellent latent thermal catalyst without any co-initiator. The rheological results showed that Ec was highest when PU content was 30 wt% which was in good agreement with the impact strengths. This was probably due to the intermolecular hydrogen bonding between the hydroxyl group in PU and EP, resulting in increasing the crosslinking density.