• Journal of Wetlands Research
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• v.16 no.3
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• pp.355-362
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• 2014

Changes of soil properties due to sedimentation and erosion in the river estuary may lead changes in environmental factors that affect plant growth and distribution, Then habitats in the river estuary that provide various ecological functions can also be influenced. Topsoil samples were analyzed in order to understand the soil properties of important barrier islands and habitat types in the Nakdong river estuary. The samples were obtained from Phragmites communis and Scirpus planiculmis habitats, the tidal flats in the southern area of Eulsukdo, and in Mangeummerydeung, Baekhapdeung, and Doyodeung. Analyses results showed that bulk density, pH, organic matter content and total nitrogen concentration which were directly or indirectly affected by vegetation showed significant difference (p<0.05) with habitat types but no differences in water content and oxidation reduction potential which could be affected by soil texture and showed significant difference among barrier islands. Results suggested that soil properties on barrier islands in the Nakdong river estuary were influenced first by geomorphic changes due to sedimentation and erosion, and then by the presence or type of vegetation. A range of physical and chemical properties were analyzed; soil water content and bulk density (physical properties), and organic content and pH (chemical properties) were correlated with seven other soil properties, at a level of significance higher than 90%. These aspects played an important role in determining overall soil properties in the studied area.

• Journal of the Ergonomics Society of Korea
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• v.26 no.3
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• pp.91-100
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• 2007

The purposes of this research are to survey work-related risk factors of musculoskeletal disorders(MSDs) in various departments and tasks at general hospitals in non-manufacturing sectors, and to use basic data derived from the survey results in preventing work-related MSDs in hospital workers. Investigation started in March of 2006 and continued for 6 months in 220 general hospitals at Seoul, Incheon, Kyeongi, and Kangwon area. Investigators visited and interviewed workers in hospitals to identify the presence of tasks of musculoskeletal burden, the investigation results of ergonomic risk factors required by the Occupational Safety and Health Law, statistical analysis from questionnaire for musculoskeletal symptoms, and major departments and tasks that have such risk factors. Twenty-seven percents of hospitals finished the investigation of ergonomic risk factors, and 69% did not do the investigation while remained 4% did not have such factors in their hospitals. The rank order of major departments that had such musculoskeletal burdens was kitchen rooms of 143, managing departments/computer rooms/dispensaries of 137, physical treatment rooms of 109, nursing departments of 96, radiological and clinical laboratories of 63. Eighteen hospitals that did not hold legal duties by the section 148 of labor minister decree practiced prevention programs of MSDs according to the labor-management cooperation. Nursing departments ranked in the first place for the numbers of musculoskeletal symptoms of 438. Managing departments/computer rooms/dispensaries, kitchen rooms, and medical treatment departments held 127, 52 and 45 symptoms, respectively. The magnitude order of physical symptom areas followed shoulder of 185, backs and waist of 166, hand wrists of 120, necks of 110, and legs/feet of 106. The departments and jobs that had major work-related ergonomic risks were patient transporting, central supplying, patient nursing (moving patients into wheel-chairs, changing of patient posture and sheet alteration), manual transporting, operation, and managing/computer departments.

• Clean Technology
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• v.14 no.1
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• pp.29-34
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• 2008

Copolymerizations of propylene oxide (PO) and phthalic anhydride (PA) have been performed in the presence of double metal cyanide (DMC) catalyst as a means of incorporating ester groups in the polyol backbone. DMC catalyst was effective for the copolymerization and the reactivity ratios measured by modified Kelen-$T{\ddot{u}}d{\ddot{o}}s$ equation were $r_1(PA)\;=\;0$, and $r^2(PO)\;=\;0.248$. Four different Polyol samples containing 1.0, 2.1, 7.52, and 11.42 mol% of PA unit were utilized for the synthesis of thermoplastic polyurethanes of their hard segments of 19 wt%. As the incorporated amount of PA increases, the elongation of the resulting polyurethane decreases and the tensile strength and the tensile modulus increase. The modulation of the incorporated amount of PA into polyol backbone was proven to be a feasible way to tune the physical properties of polyurethanes.

• Preventive Nutrition and Food Science
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• v.8 no.1
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• pp.24-28
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• 2003

There is evidence to suggest that cranberry juice supplements improve the health of the urinary tract by inhibiting the binding of fimbriated uropathogenic E. coli to the bladder mucosa. In patients with neurogenic bladders, urinary tract infections (UTI) are particularly common and often poorly managed by antibiotic treatment. A double-blind, randomized, placebo-controlled trial was undertaken on 29 geriatric and spinal cord injured patients with dysfunctional bladders. They received three times daily at mealtimes a 4 oz bottle of cranberry juice (Ocean Spray Cranberries, USA) or a specially prepared synthetic placebo drink. Two episodes of UTI arose in week one of cranberry intake and none thereafter, compared to four episodes of UTI in 4 placebo patients in weeks four, six and 10. Mean bacterial adhesion counts on bladder cells of the patients rose during the first month of treatment in 71 % of the placebo patients compared to only 31 % of cranberry patients (p < 0.001). The difference persisted to some extent for the second and third months. Bacterial adhesion levels correlated with culture findings (higher adhesion and higher viable counts in urine) (p < 0.001), positive leukocyte nitrite tests (136$\pm$131 bacteria per cell versus 52$\pm$86 in negative tests) (p < 0.001), and higher white blood cell counts (> 10) per high power field (126$\pm$125 versus 48$\pm$85 bacteria per cell) (p<0.001). E. coli was the most frequently isolated organism (40% samples) followed by K. pneumoniae (17%) and a number of other uropathogens. Group B Streptococci, and coagulase negative Staphylococcus were recovered from urine in 4 samples but were not associated with any red blood cell presence. The daily intake of cranberry juice, in amounts which are not detrimental to long term compliance, appeared to have a role in reducing the risk of bladder colonization and infection in a highly susceptible patient population.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.13 no.3
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• pp.219-225
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• 2020

With the aging population, the prevalence of musculoskeletal disorders in the elderly continues to increase. In addition, musculoskeletal disorders are the third most common social and economic loss among occupational illnesses in Workers' compensation insurance benefits as of 2015 standard and are also common among workers. In this study, a vest that can assist in the prevention and treatment of musculoskeletal disorders of the waist was produced, and it is intended to confirm the presence or absence of the effect through experiments. Diseases of the waist are closely related to core muscles. Therefore, the produced vest was made in a form that supports the core muscles. Before and after wearing the vest for effectiveness verification, the While performing 10-times of the Mackenzie exercises, a waist extension exercise, collected the EMG data of the internal oblique, Rectus abdominis, and Erector spinae, which correspond to the core muscles. The collected data were analyzed through the electromyography analysis program RM-3 to obtain RMS values for 10-times measurements of each muscle and to compare the average values. After comparing the data, to verify the significance, the technical statistical value of the measurement result was calculated and the average difference was verified through PASW ver18.0, And the paired t-test is performed on the experimental results to perform statistical processing. and Statistical processing was performed by setting the significance level to α=.05.

• Applied Chemistry for Engineering
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• v.9 no.5
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• pp.680-688
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• 1998

The macroreticular (MR) type glycidylmethacrylate (GMA)-divinylbenzene (DVB) copolymer (polyglycidylmethacrylate) beads (RG) were prepared by a suspension polymerization using 0~100 vol % of 2,2,4-trimethylpentane (TMP) as a diluent. Macroreticular type cation exchange resins containing phosphoric acid groups (RGP) were prepared by the reaction of GMA-DVB copolymer and poly (glycidyl methacrylate) bead (RG) with phosphoric acid in the presence of benzene. In this study, the effect of degree of crosslinking and the amount of the diluent on physical properties and adsorbability of uranium of RGP resins were investigated respectively. The chemical and physical properties of RGP resins were affected by both of the amount of the diluent and the degree of crosslinking. The effect of degree of crosslinking on the adsorbed amount of uranium for RGP resins were decreased in the order of $$RGP-10(50){\sim_=}RGP-1(50)>RGP-2(50)>RGP-5(50)>RGP-0$$. The effect of the diluent amount were as follows RGP-2(100)>RGP-2(75)>RGP-2(50)>RGP-2(30)>RGP-2(0). The crosslinking degree effect on uranium adsorbability depended on pore structure, cation exchange capability and swelling ratio. On the other hand, the effect of the diluent amount were relied on surface area and pore structure raher than cation exchange capability.

• Restorative Dentistry and Endodontics
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• v.23 no.1
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• pp.68-93
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• 1998

The physical properties of polymer are greatly influenced by the extent to which a resin cures. The presence of un reacted monomer can, have a plasticizing effect on the polymer, thereby altering the physical and mechanical properties of dentin bonding agent (DBA). If the DBA does not polymerize sufficiently, it will leave a weak bonding layer and lead to lower bond strength. The purpose of this study was to evaluate the shear bond strengths(SBS) and the degree of conversion (DC) of 4 commercialy avilable dentin bonding systems which are composed of 2 multi-bottle systems [Scotchbond Multi-Purpose (SMP), AeliteBond(AB)] and 2 onebottle systems [SingleBond(SB), One-Step(OS)]. For shear bond strength measurement, labial surfaces of freshly extracted bovine incisors were ground with # 600 grit SiC paper to expose dentin. Four different groups of samples were formed, with 10 samples. being made for each of the 4 commercial DBA in each group according to the curing sequences of DBA and overlayer thickness of composites: Group I (standard cure and 1mm thick composites) : The DBA was light cured and the composites of 1mm thickness was applied ; Group II (standard cure and 2mm thick composites) : The DBA was light cured and the composites of 2mm thickness was applied; Group III (simultaneous cure and 1mm thick composites) : The DBA was not light-cured and simultaneously cured with composites of 1mm thickness; Group N (simultaneous cure and 2mm thick composites) : The DBA was. not light-cured and simultaneously cured with composites of 2mm thickness. The SBS was measured immediately after the composites was bonded to the bovine dentin using an Instron machine. The DC of the DBA was examined in a thin film under simulated conditions of the experimental groups according to the curing sequences and overlayer thickness of composites in the SBS test. using a Fourier transform Infrared(FTIR) spectrometer. The following results were obtained from SBS tests and DC measurements 1. In SBS tests, the multi-bottle DBA(SMP, AB) had a generally higher bond strength values than the one bottle DBA(SB, OS). In DC measurements, the one bottle DBA(SB, OS) had a significantly higher DC than the multi-bottle DBA(SMP, AB). 2. In all DBAs except OS, there was no significant difference between the bond strength of group I (standard cure and 1mm thick composites) and that of group III (simultaneous cure and 1mm thick composites). SMP, SB in Group I had a significantly higher DC than those in group III, but AB, OS in group I had a significantly lower DC than those in group III 3. All DBAs in Goup II (standard cure and 2mm thick composites) had significantly higher bond strength and DC than those in Group N (simultaneous cure and 2mm thick composites). 4. In all DBAs, there was no significantly different SBS and DC between Group I and Group II, but all DBAs in Group III had significantly higher SBS and DC than those in Group IV.

• Journal of Adhesion and Interface
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• v.15 no.1
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• pp.22-30
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• 2014

Self-photoinitiating acrylate (SPIA) which can undergo self-initiation under UV irradiation was synthesized by a Michael addition in the presence of a base catalyst. The SPIA polymerizations were investigated by photo-differential scanning calorimeter (photo-DSC) and surface physical properties such as pendulum hardness and pencil hardness. The results showed that the SPIA can cure upon UV irradiation by itself without a photoinitiator. But we found out that both the curing rate and the conversion were too low for the self-curing reaction of SPIA. In order to improve the SPIA curing properties, we introduced the SPIA/cationic hybrid system and observed the effects of the addition of commercial free radical type monomer and photoinitiator on the curing behaviors. SPIA/cationic hybrid system was the best suitable to improve the SPIA curing properties. The kinetic analysis indicated that the cationic monomer and photoinitiator apparently accelerated the cure reaction and rate of the hybrid SPIA system, mostly due to the synergistic effect of cationic monomer and photoinitiator increasing the mobility of active species and the generation of reactive species (free radical, cation) during the photopolymerization process. The physical properties showed that, unlike typical free radical system, the hybrid systems did not show oxygen inhibition effect because of cationic reaction on the coating surface.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.6
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• pp.297-305
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• 2019

This study was conducted to compare the factors affecting quality of life according to the perception of subjective body image in adult women as a secondary study of the 7th 1st year Korean National Health and Nutrition Examination Survey data. The subjects were 3,392 adult women and their general characteristics, physical factors and psychological factors were analyzed. Data were analyzed using the IBM SPSS 25.0 program after generating weighted composite sample plans and the significance level was set at 0.05. Factors influencing the quality of life of subjects who perceived their subjective body image as thin were education level, birth experience, depression, and subjective health and their explanatory power was 43.1%. Factors influencing the quality of life for those who perceived their bodies as moderate were education level, depression, and subjective health, and their explanatory power was 26.5%. Factors that affected quality of life for those who perceive their bodies as obese were age, weight change for one year, weight control for one year, presence of high blood pressure, BMI, and subjective health, and their explanatory power was 40.9%. The results of this study indicate it is necessary consider the factors influencing each subjective perception to improve individual quality of life.

• Korean Journal of Clinical Laboratory Science
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• v.51 no.2
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• pp.134-144
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• 2019

Metabolic syndrome and allergic rhinitis are two important chronic diseases that affect people all over the world. Metabolic syndrome very often induces other diseases and the prevalence of allergic rhinitis is currently increasing. Aging is known to affect the pathogenesis of various diseases such as metabolic syndrome and allergy. This study examined the effects of metabolic syndrome and the prevalence of allergic rhinitis depending on different age groups and several general characteristics. This study was conducted by using the data from the Korea National Health and Nutrition Examination Survey from the 4th, 5th, 6th, and 7th-1 (2007~2016). The data used for this study was obtained from 51,854 people. In all age groups, our studies have shown that people without metabolic syndrome have a higher prevalence of allergic rhinitis than those people with metabolic syndrome, and the younger age group had the higher prevalence of allergic rhinitis (P<0.05). Overall, the results of this study found a significant effect on the prevalence of allergic rhinitis in each category of age, general characteristics (physical activity, smoking and drinking) and the presence or absence of metabolic syndrome (P<0.05). The evidence found in this study will help to understand the correlation between metabolic syndrome and allergy, and specifically allergic rhinitis.