• Corrosion Science and Technology
• /
• v.16 no.5
• /
• pp.257-264
• /
• 2017

Film of new Ti-15Zr-5Nb alloy formed during galvanic anodizing in orthophosphoric acid solution was characterized by optical microscope, scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), and Raman micro-spectroscopy. Its anticorrosive properties were determined by electrochemical techniques. The film had a layer with nanotube-like porosity with diameters in 500-1000 nm range. The nano layer contained significant amounts of P and O as well as alloying element. Additionally, Raman micro-spectroscopy identified oxygen as oxygen ion in $TiO_2$ anatase and phosphorous as $P_2O_7{^{4-}}$ ion in phosphotitanate compound. All potentiodynamic polarization curves in artificial Carter-Brugirard saliva with pH values (pH= 3.96, 7.84, and 9.11) depending on the addition of 0.05M NaF revealed nobler behavior of anodized alloy and higher polarization resistance indicating the film is thicker and more compact nanolayer. Lower corrosion rates of the anodized alloy reduced toxicity due to less released ions into saliva. Bigger curvature radii in Nyquist plot and higher phase angle in Bode plot for the anodized alloy ascertain a thicker, more protective, insulating nanolayer existing on the anodized alloy. Additionally, ESI results indicate anodized film consists of an inner, compact, barrier, layer and an outer, less protective, porous layer.

• Journal of the Korea Convergence Society
• /
• v.9 no.1
• /
• pp.59-65
• /
• 2018

The purpose of this study was to examine the perceived oral health status and self-efficacy influencing in university students with fear of intimacy. Data were collected through a questionnaire from 557 university students with self-reporting questionnaires for perceived oral health status, self-efficacy and fear of intimacy. Data were analyzed using SPSS 22.0. The results were analyzed using t tests, analyses of variance, Duncan's multiple range tests, correlation analyses and multiple regression analyses. As the results of this study, The fear of intimacy was low in university students with high self-efficacy and positively perceived oral health status.The variables that have the greatest effect on fear of intimacy were self-efficacy, followed by perceived oral health status, past dating experience.

• Journal of Forest and Environmental Science
• /
• v.31 no.3
• /
• pp.214-224
• /
• 2015

The economy of India and so also of many Asian countries depends on bamboos and their uses are not only in domestic items but also in rural housing and raw materials to several industries and germplasm characterization is an important link between the conservation and utilization of plant genetic resources. Classical taxonomic studies of the bamboos are based on floral morphology and growth habit, which can cause problems in identification due to erratic flowering coupled with different biotic agencies and environmental factors. Identification and genetic relationships among accessions of Thamnocalamus falconeri were investigated using morphology and random amplified polymorphic DNAs (RAPD) technique. Analysis started by using 51 vegetative characters and forty two 10-mer primers that allowed us to distinguish different genotypes hailing from different eco- zones of Garhwal Himalayas (India). The selected primers (12) were used for identification and for establishing a profiling system to estimate genetic diversity. A total of 79.33% polymorphism was estimated by using 12 selected primers. The genetic similar analysis was conducted based on binary digits i.e. presence (1) or absence (0) of bands, which revealed a wide range of variability among the species whereas genetic relatedness was quite high based on vegetative characters. Cluster analysis clearly showed two major clusters for both of the markers viz. morphology and RAPD belonging to 10 accessions of T. falconeri. Two major clusters were further divided into minor clusters. Cluster based on RAPD marker showed grouping of accessions of closed locality whereas analogy was reported for vegetative traits. The RAPD technique has the potential for use in species identification and genetic relationships studies of bamboo for breeding program.

• Journal of the Korean Chemical Society
• /
• v.28 no.4
• /
• pp.231-237
• /
• 1984

The x-values in the nonstoichiometric chemical formulas $YO_{1.5+x}\;and\;HoO_{1.5+x}$, have been measured in the temperature range from 700$^{\circ}$C to 1000$^{\circ}$C under oxygen pressures from $2{\times}l0^{-1}\;to\;1{\times}10^{-6}$ atm by gravimetric method. The observed x-values increase with increasing temperature and oxygen pressure. The enthalpies of formation of excess oxygen in yttrium oxide and holmium oxide decrease with decreasing oxygen pressure and are all positive values representing an endothermic process. The 1/n values calculated from the slopes of the plots of log x vs. log $P_{O2}$ increase with temperature and are positive values which means the higher oxygen pressure dependence at higher temperature. We have examined the nonstoichiometric defect and conduction mechanism from x-values and thermodynamic data.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.16 no.4
• /
• pp.355-367
• /
• 2004

The heat transfer and friction characteristics of the heat exchangers having sinusoidal wave fins were experimentally investigated. Twenty-nine samples having different waffle heights (1.5 mm and 2.0 m), fin pitches (1.3mm to 1.7mm) and tube rows (one to three) were tested. Focus was given to the effect of the waffle configuration (herringbone or sinusoidal) on the heat transfer and friction characteristics. Results show that the sinusoidal wave geometry provides higher heat transfer coefficients and friction factors than the herringbone wave geometry, and the difference increases as the number of row increases. The i/f ratios of the herringbone wave geometry, however, are larger than those of the sinusoidal wave geometry. Compared to the herringbone wave geometry, the sinusoidal wave geometry yielded a weak row effect, which suggests a superior heat transfer performance at the fully developed flow region. Possible explanation is provided considering the flow characteristics in wavy channels. Within the present geometric range, the effect of the waffle height on the heat transfer coefficient was not prominent. The effect of the fin pitch was also negligible. Existing correlations highly overpredicted both the heat transfer coefficients and friction factors. A new correlation was developed using the present data.

• International Journal of Highway Engineering
• /
• v.19 no.1
• /
• pp.45-52
• /
• 2017

PURPOSES : The main purpose of this study is to develop a high elastic modulus and low-shrinkage roller-compacted concrete base (RCCB) in order to prevent fatigue cracking and reflective cracking in the asphalt surface layer of composite pavement. Using a rigid base material with low shrinkage can be a solution to this problem. Moreover, a strong rigid base with high elastic modulus is able to shift the location of critical tensile strain from the bottom of the asphalt layer to the bottom of the rigid base layer, which can prevent fatigue cracking in the asphalt layer. METHODS : Sensitivity analysis of composite pavement via numerical methods is implemented to determine an appropriate range of elastic modulus of the rigid base that would eliminate fatigue cracking. Various asphalt thicknesses and elastic moduli of the rigid base are used in the analysis to study their respective influences on fatigue cracking. Low-shrinkage RCC mixture, as determined via laboratory testing with various amounts of a CSA expansion agent (0%, 7%, and 10%), is found to achieve an appropriate low-shrinkage level. Shrinkage of RCC is measured according to KS F 2424. RESULTS : This study shows that composite pavements comprising asphalt thicknesses of (h1) 2 in. with E2 > 19 GPa, 4 in. with E2 > 15 GPa, and 6 in. with E2 > 11 GPa are able to eliminate tensile strain in the asphalt layer, which is the cause of fatigue cracking in this layer. Shrinkage test results demonstrate that a 10% CSA RCC mixture can reduce shrinkage by 84% and 93% as compared to conventional RCC and PCC, respectively. CONCLUSIONS : According to the results of numerical analyses using various design inputs, composite pavements are shown to be able to eliminate fatigue cracking in composite pavement. Additionally, an RCC mixture with 10% CSA admixture is able to reduce or eliminate reflective cracking in asphalt surfaces as a result of the significant shrinkage reduction in the RCC base. Thus, this low-shrinkage base material can be used as an alternative solution to distresses in composite pavement.

• Journal of Veterinary Clinics
• /
• v.22 no.4
• /
• pp.392-395
• /
• 2005

A three-year old intact female German shepherd dog weighing 32kg was presented with the history of regurgitation and vomiting. Physical examination revealed a thin body condition, hoarse voice, hypersalivation, and pelvic limb weakness. In radiograph, meagaesophagus was identified. The neostigmine challenge test was positive. The titer of acetylcholine receptor (AChR) antibody was 1.58 nmol/L (reference range, <0.6nmol). Therefore, the dog was diagnosed to be suffering with chronic generalized form of acquired myasthenia gravis and followed by treatment with pyridostigmine bromide, 1mg/kg, q12 hrs. Treatment improved the pelvic limb weakness, however intermittent regurgitation and vomiting persisted. This resulted in aspiration pneumonia f3r which antibiotics were administered However, the dog was euthanized due to poor management and owner's request.

• Asian-Australasian Journal of Animal Sciences
• /
• v.15 no.5
• /
• pp.751-756
• /
• 2002

A study was carried out to evaluate the incidences and causes of bovine mastitis in Tanzanian shorthorn zebu (Bos indicus) in the traditional sector and crossbred cows (Bos taurus${\times}$Bos indicus) in the dairy ranching sector, both found under the extensive range management system. Management practices were evaluated through a survey study using structured questionnaires. A total of 120 lactating cows (60 cows from each sector) were screened for the disease using the California Mastitis Test (CMT). Confirmatory tests used for infected cows included; the Direct Microscopic Somatic Cell Count (DMSCC), culture, bacteriological and biochemical laboratory assays. Survey results showed that management practices were generally very poor in both sectors with 84% of the surveyed herds being kept and milked under very unhygienic environmental conditions. The level of infection was higher in the crossbred cows (5% clinical and 38.3% sub-clinical mastitis) and lower in the zebu cows with only sub-clinical mastitis (23.3%). Crossbred cows had (p<0.05) higher somatic cell counts than zebu cows. The four highest-ranking bacterial isolates in order of importance were Staphylococcus aureus, Escherichia coli, Streptococcus agalactiae and Bacillus spp. It was concluded that bovine mastitis under the extensive management system in Tanzania was a result of poor management practices and that zebu cows were more resistant to the diseases than crossbred cows.

• Journal of Korean Neurosurgical Society
• /
• v.59 no.5
• /
• pp.512-517
• /
• 2016

Objective : The pathophysiology of idiopathic Chiari malformation (CM) type 1 is disturbance of free cerebrospinal fluid (CSF) flow and restoration of normal CSF flow is the mainstay of treatment. Additional migration of the medulla oblongata in pediatric patients is referred to as CM type 1.5, but its significance in adult patients is unknown. This study is to compare surgical outcomes of adult idiopathic CM type 1.5 with that of type 1. Methods : Thirty-eight consecutive adult patients (M : F=11 : 27; median, 33.5; range, 18-63) with syringomyelia due to idiopathic CM type 1 were reviewed. Migration of the medulla oblongata was noted in 13 patients. The modified McCormick scale (MMS) was used to evaluate functional status before and one year after surgery. All patients underwent foramen magnum decompression and duroplasty. Factors related to radiological success (${\geq}50%$ decrease in the diameter of the syrinx) were investigated. The follow-up period was $72.7{\pm}55.6$ months. Results : Preoperative functional status were MMS I in 11 patients and MMS II in 14 of CM type 1 and MMS I in 8 and II in 5 of CM type 1.5. Of patients with MMS II, 5/14 patients in group A and 3/5 patients in group B showed improvement and there was no case of deterioration. Radiological success was achieved in 32 (84%) patients and restoration of the cisterna magna (p=0.01; OR, 46.5) was the only significant factor. Conclusion : Migration of the medulla oblongata did not make a difference in the surgical outcome when the cisterna magna was restored.

• Korean Journal of Bronchoesophagology
• /
• v.13 no.1
• /
• pp.33-38
• /
• 2007

Background and Objectives: A plunging ranula represents a mucus escape reaction occuring because of the disruption of the sublingual salivary gland. It is commonly a condition of young adults, although the reported age range is 6-43 years. There is said to be a slightly female preponderance of about 1.9:1(F:M). Surgical incision has been considered the definite treatment, but sometimes complete excision is very difficult. Non-surgical treatment of these lesions has been attempted, but the results have not been satisfactory. In this study, we present our experiences with picibanil (OK-432) sclerotherapy for a plunging ranula. Materials and Methods: We retrospectively reviewed 41 patients who have undergone sclerotherapy with picibanil for plunging ranula. Information was collected on age, sex, a number of injection, post-sclerotherapy side effect and outcome of treatment. Results: 17 patients (41.5%) showed a complete response, and 20 patients (48.7%) showed inter-mediate response. No response was seen in 4 patients (9.8%). As a side effect of intracystic OK-432 injection therapy, fever (26.8%) and pain(39.0%) were observed. However, fever and pain disappeared after several days in all cases. Conclusion: The results are showing that OK-432 injection is an effective and safe treatment for plunging ranula.