• Journal of Pharmacopuncture
• /
• v.23 no.1
• /
• pp.1-7
• /
• 2020

Nicotine, primary component of tobaco produces craving and withdrawal effect both in humans and animals. Nicotine shows a close resemblance to other addictive drugs in molecular, neuroanatomical and pharmacological, particularly the drugs which enhances the cognitive functions. Nicotine mainly shows its action through specific nicotinic acetylcholine receptors located in brain. It stimulates presynaptic acetylcholine receptors thereby enhancing Ach release and metabolism. Dopaminergic system is also stimulated by it, thus increasing the concentration of dopamine in nuclear accumbens. This property of nicotine according to various researchers is responsible for reinforcing behavioral change and dependence of nicotine. Various researchers have also depicted that some non dopaminergic systems are also involved for rewarding effect of nicotinic withdrawal. Neurological systems such as GABAergic, serotonergic, noradrenergic, and brain stem cholinergic may also be involved to mediate the actions of nicotine. Further, the neurobiological pathway to nicotine dependence might perhaps be appropriate to the attachment of nicotine to nicotinic acetylcholine receptors, peruse by stimulation of dopaminergic system and activation of general pharmacological changes that might be responsible for nicotine addiction. It is also suggested that MAO A and B both are restrained by nicotine. This enzyme helps in degradation dopamine, which is mainly responsible for nicotinic actions and dependence. Various questions remain uninsurable to nicotine mechanism and require more research. Also, various genetic methods united with modern instrumental analysis might result for more authentic information for nicotine addiction.

• Journal of Korean society of Dental Hygiene
• /
• v.13 no.3
• /
• pp.525-534
• /
• 2013

Objectives : This study aimed to improve school health program by investigation of several variables through educational diagnostic factors which influence the level of subjective oral health perception and DMFT of students on the basis of PRECEDE model. Methods : A total of 286 high school students in Busan completed the self-reported questionnaire from September 3 to 28 in 2012. Results : 1. Social and epidemiologic diagnosis suggested that the level of subjective oral health perception of male students was not better than that of female students and DMFT number of the male was more than that of the female(p<0.001)(p<0.001). 2. Oral health diagnosis indicated that once a day tooth brushing group showed lower level of oral health perception(p<0.001) and high DMFT number(p<0.001). 3. Predisposing factor of educational diagnosis implied that more than 4 times a day snack intake group and sweet diet and soda friendly group showed lower level of oral health perception and high DMFT number(p<0.001). 4. Tooth brushing of the reinforcing factors had the most important effect on the level of oral health perception and the number of dental caries. Daily snack intake was the most important effect on DMFT number. Conclusions : The informed consent from each family was the important factor in implementing PRECEDE model. School health program improved oral health care. Oral health program can correct the risk oral health behavior in children and adolescents.

• Korean Journal of Acupuncture
• /
• v.22 no.3
• /
• pp.17-26
• /
• 2005

Objectives : The aim of this study is to investigate the effect of Shinmun-acupuncture stimulation on the relationship of change in electrocardiopgraphy (ECG). Methods : For this purpose, 11 healthy volunteers were acupunctured at Shinmun acupoint using the reinforcing or reducing by inserting the needle in the same direction as the channel runs or in the opposite direction (迎隨補瀉). Then, we measured and observed the change of standard leads I, II and III in ECG. Results : In lead I , acupuncture treated groups were increased the activity of PR interval and PR segment compared to the control group. In lead II, during the acupuncture treated group by inserting the needle in the opposite direction as the channel runs was increased the activity of T wave duration, and after the acupuncture group by inserting the needle in the same direction as the channel runs was increased the activity of PR interval. In lead III, acupuncture treated groups were increased the activity of ST duration, PR interval and QT interval. Conclusions : These results suggested that Shinmun acupuncture stimulation plays an important role on the activities of ECG.

• Korean Journal of Materials Research
• /
• v.8 no.12
• /
• pp.1077-1081
• /
• 1998

Wood powder as reinforcing fillers and polyethylene as a matrix have been used for wood plastic composites (WPC). In preparing WPC, counting agents (such as MA and MAOMS) were also used in order to improve the bonding force between matrix and fillers. In this study, the effect of wood powder, MA, MAOMS concentration on the mechanical properties and interface phenomena on the composites was evaluated The tensile strength of 3wt% MA-treated composites reached its maximum value of 25.91MPa while 3wt% MAOMS-treated composites attained the maximum value of 22.48MPa. The maximum impact strength of MA and MAMOS-treated composites were 44.38J/m and 36.09J/m, respectively, when 3wt% of coupling agent was introduced.

• Journal of the Korean Geotechnical Society
• /
• v.19 no.2
• /
• pp.189-197
• /
• 2003

In this paper, deformation characteristics of fiber-mixed-soils were studied at small strain range(0.0001%～1%) using resonant column test and triaxial test, and reinforcement effect was evaluated by the measure of maximum shear moduli. The effects of the major parameters such as fiber content, aspect ratio and fiber type on reinforcement were comparatively assessed. The specimens were remolded from Jumunjin Sand randomly mixed with discrete polypropylene staple fibers. Maximum shear moduli of fiber-mixed-soils increased by up to 30% and modulus reduction was also restrained in nonlinear range. Shear moduli increased as the aspect ratio increases. The reinforcement was more effective with fibrillated fiber than with monofilament fiber. The most effective reinforcement was achieved with the specimen of 0.3 % fiber content.

• KCI Concrete Journal
• /
• v.11 no.3
• /
• pp.201-210
• /
• 1999

An experimental study was carried out to determine pullout behavior of a new type of anchor bolt that used deformed reinforcement and a commercial adhesive. Concrete slabs and columns with about 20-MPa compressive strength were used for 136 pullout tests performed. Test variables included anchor diameter (10 mm ~ 32 mm). embedment depth (10$\Phi$ or 15$\Phi$), edge effect. and Presence of transverse reinforcement in existing concrete. In Tyre-S test. where the edge or reinforcing steel effect was not included, the anchor Pullout strengths increased with increasing anchor diameters. Anchors with 15$\Phi$ embedment depth had higher Pullout strengths than those with 100 embedment depth The largest average Pullout load of 208 kN was determined for anchors made with D25 reinforcement and with 15$\Phi$ embedment depth. In Type-E tests, where the anchors were installed close to the edge of existing concrete, there were reductions in pullout strengths when compared to those determined in Type-S tests. In Type-ER tests, influence of the reinforcement in existing concrete on the anchor pullout strengths was examined using reinforced concrete and plain concrete columns Test results indicated that existing transverse reinforcement (column ties) did not help increase the pullout strength. The overall pullout test results revealed that the new anchor bolt can develop large pullout strengths while the anchors can be made of materials that are readily available in the market.

• Journal of the Korean Society of Safety
• /
• v.23 no.6
• /
• pp.131-137
• /
• 2008

SCP(Sand Compaction Pile) method that forms a composite ground by driving compacted sand piles into the soft ground. This method is one of the soil improvement techniques for reinforcing and strengthening soft ground deposits. This thesis describes the investigation on the behavior of soft ground reinforced with SCP by low improvement ratio. Direct shear test and consolidation test carried out to verified behavior of composite ground reinforced with SCP. Test results were discussed with reference to the amount of consolidation settlement, variation of shear resistance with area replacement ratio and effect of the stress concentration. And, laboratory model loading test carried out to verified the effect of the location and failure mode of reinforced embankment. Residual shear strength varies with the area replacement and constrict load in the low replacement ratio. Calculated stress concentration ratio overestimate than proposed valve by experimental, theoretical and analytical method. As regards the location, improving right below of the top of the slope was more effective than below of the toe of the slope. This thesis carried out to obtain fundamental information of behavior of the composit ground. Hereafter, centrifuge test that reproduce stress state of the in-situ must be necessary through the further study about pile penetration, reinforce position and construct time.

• Journal of Information Technology Services
• /
• v.9 no.2
• /
• pp.129-149
• /
• 2010

Although many organizations have implemented and used ERP systems for years, industry reports point out that the usage level does not reach their expectation. As a result, they do not enjoy the benefits from the investment into ERP systems. This study attempts to develop a research model and test the model empirically for identifying factors that affect the usage of an ERP system at a public organization. This study has classified potential factors into three groups of technical system characteristics (usability, usefulness), organizational support characteristics (operational support, education and training, evaluation and measurement), and user characteristics (organizational citizenship, self-efficacy). Then, a structural equation model has been established on the basis of previous literature and tested with empirical data. In summary, this study has found that self-efficacy, usefulness, and operational support have an effect on the ERP usage. Self-efficacy is the strongest factor; Usefulness is the second; and the third is operational support. On the contrary to the previous literature, this study has not found a significant effect of organizational citizenship on the usage. The result confirms that an organization can increase the ERP usage by improving the usefulness of an ERP system to some extent. However, to boost the usage further, the result implies that organizations need to strengthen the self-efficacy of their members by reinforcing operational support, providing education and training steadily, and establishing an evaluation mechanism in relation with the ERP usage.

• Advances in materials Research
• /
• v.6 no.3
• /
• pp.245-255
• /
• 2017

High energy ball milling is employed to produce iron matrix- multiwall carbon nanotube (MWCNT) reinforced composite. The damage caused to MWCNT due to harsh ball milling condition and its influence on interfacial bonding is studied. Different amount of MWCNT is used to find the optimal percentage of MWCNT for avoidance of the formation of chemical reaction product at the matrix - reinforcement interface. Effect of process control agent is assessed by the use of different materials for the purpose. It is observed that ethanol as a process control agent (PCA) causes degradation of MWCNT reinforcements after milling for two hours whereas solid stearic acid used as process control agent, allows satisfactory conservation of MWCNT structure. It is further noted that at a high MWCNT content (~ 2wt.%), high energy ball milling leads to reaction of iron and carbon and forms iron carbide (cementite) at the iron-MWCNT interface. At low percentage of MWCNT, dissolution of carbon in iron takes place and the amount of reinforcement in iron matrix composite becomes negligibly small. However, under the present ball milling condition (ball to metal ratio~ 6:1 and 200 rpm vial speed) iron-1wt.% MWCNT composite of good interfacial bonding can retain the tubular structure of reinforcing MWCNT.

• Proceedings of the KSR Conference
• /
• 2008.11b
• /
• pp.928-934
• /
• 2008

Resently, Fiber Reinforced Concrete is used for not only preventing crack of concrete but also reinforcing general methods. Steel Fiber and PP(poly-propylene) Fiber are usually used as fiber reinforced materials. However, using these materials for shotcrete on Railway tunnel can cause some problems such as damage of pressure hose and shotcrete rebound. In addition, Steel fiber is an expensive material and it can cause safety problems during applying to shotcrete. PP Fiber can cause a problem in fiber balling during applying to shotcrete railway tunnel construction. A purpose of the research is applying a development of PET(Poly Etylene Terephtalate) fiber by recycling pet bottles to the shotcrete tunnel exposed to explosion spalling. To investigate the reinforcement effect of the PET fiber, some basic tests are accomplished to physical properties and explosion spalling by fire. As a result of the tests, a concrete mixing the PET fiber has stronger resistance effect in the explosion spalling by high temperature than another strong fiber concrete does, and that the former concrete is also equal or more effective on the result of the above tests to physical properties like compression and strain than the latter one is demonstrated.