• Journal of Korean society of Dental Hygiene
• /
• v.9 no.4
• /
• pp.606-619
• /
• 2009

Objectives : This study was to examine the state of customized visiting oral health programs in a bid to help facilitate the unified operation of the programs and the development of required guidelines. Methods : The subjects in this study were 49 dental hygienists who were professionals responsible for customized visiting health care programs across the nation. Results : 1. Regarding the form of employment of the dental hygienists were investigated many contract and daily workers. 2. As to the possession of equipment necessary for visiting oral health programs, denture cleaners(12.2%) were most widely possessed in some regions, followed by mobile scalers(10.2%) and mobile suctions(8.2%). In terms of expendable devices and materials, dental mirrors, pincettes and explorers were the most widely possessed dental checkup devices, and the most widely possessed oral hygiene supplies were toothbrushes, interdental brushes and denture cleaners. Those devices and materials were in more possession than the other types of devices and materials. The most widely possessed equipment for educational purpose was laptop computers, followed by beam projectors and screens. The most widely possessed teaching materials were dentiform, followed by CD-ROMs. 3. Those whom they visited the most for oral health care service were elderly people, followed by the disabled and patients with chronic diseases. The dental hygienists who went out to visit those people outnumbered the others who stayed at public health centers. Concerning the types of visiting oral health care service, the most prevalent service provided to the elderly included denture cleaning/management, oral massage and preventive treatment against dental caries. The most dominant service provided to the disabled involved education of the oral health care act, preventive treatment against dental caries and toothbrushing by professionals. The most common service offered to patients with chronic diseases was education of the oral health care act and oral health education. The dental hygienists paid a visit to a mean of 5.8 households a day. The average weekly number of households cared by the dental hygienists was 27.3. It took a mean of 37.1 minutes for them to take care of each household. 4. As for satisfaction level with the implementation of the visiting oral health programs, they expressed the greatest satisfaction at teamwork with professionals($3.56{\pm}0.94$), followed by the professionalism of their work($3.21{\pm}0.94$) and workload($3.08{\pm}0.94$). Their satisfaction level with the work conditions required for creative job performance($2.75{\pm}0.98$) and partnership with other institutions($2.64{\pm}1.03$) was below 3.0. In regard to the impact of their characteristics, marital status made a statistically significant difference to satisfaction level with workload. The unmarried dental hygienists were more pleased with their workload than the married ones(p<0.05). 5. As to needs for education for professionalism improvement, they asked for education about visiting oral health care skills the most, followed by education about oral health care for patients with chronic diseases, education of planning/evaluation and education of oral health care for the disabled. Conclusions : The top priority for the vitalization of the programs was the procurement of budget, followed by the procurement of equipment and educational media and the procurement of human resources.

• Journal of the Korean Geosynthetics Society
• /
• v.10 no.3
• /
• pp.25-32
• /
• 2011

The matric suction and volumetric water content of dredging soils obtained from Saemangeum area were measured by the automated Soil-Water Characteristic Curve (SWCC) apparatus under both drying and wetting conditions. Based on the test result, SWCCs of the dredging soils were estimated by the van Genuchten(1980) model. The matric suction of drying process is larger than that of wetting process at a same effective degree of saturation. The suction stresses for various matirc suctions were estimated using Lu and Likos(2006) model and the Suction Stress Characteristic Curves (SSCC) were predicted using the independent parameter of SWCC. The suction stress of drying path was increased and decreased, while the suction stress of wetting path was continuously decreased with increasing the effective degree. Also, the suction stress of drying path is larger than that of wetting path at a same effective degree of saturation. The Hydraulic Conductivity Function(HCF) was also predicted by the van Genuchten(1980) model. The hydraulic conductivity was increased with increasing the volumetric water content. The hydraulic conductivity of drying path is larger than that of wetting path at a same matric suction. According to the results of SWCCs and SSCCs, the hysteresis phenomenon of suction stress or matric suction during both drying and wetting paths was occurred. The main reason of hysteresis phenomenon is a ink bottle effect of water among soil particles.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.32 no.4C
• /
• pp.169-175
• /
• 2012

Soil water retention characteristics are influenced by factors of the confining stress and hysteresis in the variably saturated soil. In the description of effective stress based on hydraulic characteristics, the contribution of a matric suction to effective stress then varies with depth or is different between the processes of infiltration and evaporation. Unsaturated effective stress can be described based on suction stress characteristic curve, in which a representative soil water retention curve is required to evaluate. Pressure palate extractor tests under various confining stresses were performed and the hysteresis of drying and wetting process was also acquired. In the process of drying or wetting, a unique relationship has been estimated on the effective volumetric water content and the matric suction, which defines suction stress characteristic curve. In the unsaturated shear strength from triaxial tests, the suction stress and the effective stress were evaluated by matric suctions. The failure envelop by effective stress based on soil water retention characteristics was unique and the same as the saturated one. The measured suction stress from triaxial tests was similar to that from the soil water retention curve. Therefore it is verified that a representative soil water retention curve can be defined which is independent of the confining effect under wetting or drying process of the hysteresis.

• Journal of the Korean Geotechnical Society
• /
• v.27 no.1
• /
• pp.41-52
• /
• 2011

The hypothesis on effective stress of unsaturated soil is validated by $K_0$ consolidation results of triaxial tests for the compacted residual soil. The stress characteristic curve (SSCC) can describe unsaturated soil behavior on water contents, which was defined from shear strength or from soil water characteristic curves. In this study, it was found that the stress path of $K_0$ consolidation can also define the SSCC. The effective stress was defined by SSCC. $K_0$ paths for various matric suctions could be described as a unique line by effective stress. The measured values of $K_0$ were interpreted by effective stress as a constant with respect to matric suction. Since the SSCC from $K_0$ consolidation agrees with that from the shear strength, the SSCC from soil water retention curve could describe effective stress behavior consistently on both $K_0$ consolidation path and stress at failure. The effective stress based on SSCC can describe the entire unsaturated behavior from consolidation to failure.

• Journal of Korean society of Dental Hygiene
• /
• v.5 no.2
• /
• pp.219-233
• /
• 2005

This study was conducted on 185 workers at 73 dental clinics and university hospitals in Daegu to investigate the actual prevention of infection and vaccination against B-type hepatitis among dental workers. 1. According to the result of medical examination, only 35 out of 144 (24%) dental clinic workers had periodic health examination while 7 out of 9 (78%) university hospital workers did. 2. In a survey on vaccination against B-type hepatitis, 52 workers aged 29 or younger (96.3%), 38 dental hygienists (51.9%) and 44 dental workers at dental clinics (81.5%) have not had any vaccination against B-type hepatitis. The rest appeared to have had vaccination or be aware that they had antibody against B-type hepatitis without having to have any vaccination. 3. According to the result of a survey on the existence of antibody by job, 42 (56%) of dental hygienists, 15 (20%) of assistant nurses, 12 (16%) of medical assistants and 6 (8%) of dental technicians did not know whether or not they had antibody. This suggests that all types of dental workers except dental hygienists have low awareness of whether or not they have antibody. 4. In a survey on the relation between general characteristics of subjects and the sterilization of dental equipment, alcohol disinfection of high speed handpiece and low speed handpiece was most common among dental workers aged 29 or younger, and all of those aged over 40 used autoclave. By position, alcohol disinfection was used most commonly for high-speed handpiece. antiseptic solution deposition for disposable suction lips, and autoclaving for impression. By workplace, dental workers at university hospitals used autoc1aving most frequently for high/low speed handpiece while those at dental hospitals and dental clinics used alcohol disinfection most frequently and even some respondents replied that they did not disinfect. For metal cups, workers at dental clinics and dental hospitals did not use any sterilizing method while those at university hospitals used autoclaving. For disposable suction tips, workers at dental clinics used antiseptic solution deposition and those at dental hospitals used alcohol disinfection but some respondents replied that they did not disinfect. For metal suctions and impression trays, autoclaving was most common in all workplaces but some dental clinics replied that they did not disinfect impression trays. According to work experience, alcohol disinfection was most common for high/low speed handpiece. For disposable suction tips, dental workers with 3 years' or shorter work experience, those with 3~6 years' experience and those with 9~12 years' experience used antiseptic solution deposition most commonly, and many of those with 6~9 years replied that they did not disinfect. The results of this study stated above suggest that systematic education is necessary for all dental workers for enhancing th eir awareness of B-type hepatitis and the prevention of infection. Moreover, dental workers are required to make efforts to prevent infection with B-type hepatitis voluntarily and actively.

• Wind and Structures
• /
• v.34 no.1
• /
• pp.115-125
• /
• 2022

The high-Reynolds number flow around a rectangular cylinder, having streamwise to crossflow length ratio equal to 5 is analyzed in the present paper. The flow is characterized by shear-layer separation from the upstream edges. Vortical structures of different size form from the roll-up of these shear layers, move downstream and interact with the classical vortex shedding further downstream in the wake. The corresponding mean flow is characterized by a recirculation region along the lateral surface of the cylinder, ending by mean flow reattachment close to the trailing edge. The mean flow features on the cylinder side have been shown to be highly sensitive to set-up parameters both in numerical simulations and in experiments. The results of 21 Large Eddy Simulations (LES) are analyzed herein to highlight the impact of the lateral mean recirculation characteristics on the near-wake flow features and on some bulk quantities. The considered simulations have been carried out at Reynolds number Re=DU_∞/ν=40 000, being D the crossflow dimension, U_∞ the freestream velocity and ν the kinematic viscosity of air; the flow is set to have zero angle of attack. Some simulations are carried out with sharp edges (Mariotti et al. 2017), others with different values of the rounding of the upstream edges (Rocchio et al. 2020) and an additional LES is carried out to match the value of the roundness of the upstream edges in the experiments in Pasqualetto et al. (2022). The dimensions of the mean recirculation zone vary considerably in these simulations, allowing us to single out meaningful trends. The streamwise length of the lateral mean recirculation and the streamwise distance from the upstream edge of its center are the parameters controlling the considered quantities. The wake width increases linearly with these parameters, while the vortex-shedding non-dimensional frequency shows a linear decrease. The drag coefficient also linearly decreases with increasing the recirculation length and this is due to a reduction of the suctions on the base. However, the overall variation of C_D is small. Finally, a significant, and once again linear, increase of the fluctuations of the lift coefficient is found for increasing the mean recirculation streamwise length.