• Journal of Digital Convergence
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• v.16 no.7
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• pp.317-324
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• 2018

The purpose of this study was to investigate factors affecting body image in adolescents. The subject of study is 140 adolescents in the three middle schools from the J city. The data were collected using a self-report questionnaire from March 15 to March 29, 2017. Data were analyzed by descriptive statistics, T-test, ANOVA, Pearson's correlation, and multiple regression with SPSS 20.0 program. Body image was found to be in a significant positive correlation with family strength and self-esteem. The result of the multiple regression indicates the self-esteem(${\beta}=.24$, p<.05), family strength(${\beta}=.19$, p<.05) and gender(${\beta}=.16$, p<.05) predict 17.9% (F=11.10, p<.001) of body image. Therefore, it is necessary to develop self-esteem and family strength strategy intervention program for establishing a right body image of adolescents.

• Journal of Technologic Dentistry
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• v.27 no.1
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• pp.9-17
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• 2005

The use of titanium alloys as biomaterials is increasing due to their superior biocompatibility and enhanced corrosion resistance compared to conventional stainless steels and cobalt-based alloys. Ti-6Al-4V ($\alpha+\beta$type) alloy instead of pure titanium ($\alpha$type) is being widely used as biomaterials has some characteristics such as high fatigue strength, tensile strength and corrosion resistance. But it has been reported recently that the vanadium element expresses cytotoxicity and the aluminium element is related with dementia of Alzheimer type and neurotoxicity. In order to overcome their detrimental effects, $\beta$-phase stabilizer Nb was chosen in the present study. This paper was described the influence of phase changes of Ti-Nb alloys on mechanical properties. Ti-3wt.%Nb($\alpha$type),Ti-20wt.%Nb($\alpha+\beta$type) and Ti-40wt.%Nb($\beta$type) alloys were melted by vacuum arc furnace. The specimens were homogenized at 1050$^{\circ}C$ for 24hr and were then hot rolled to 50% reduction. Each alloys were solution heat treated at $\beta$ zone and $\alpha+\beta$ zone after homogenization and then were aged. The mechanical properties of Ti alloys were analysed by hardness test, tensile test, elongation test and SEM test. The results can be summarized as follows: 1) The higher hardness value of $\alpha+\beta$type alloy was obtained compared to the, $\alpha,\beta$type alloys. 2) The aged treated showed better hardness compared to the solution heat treated, homogenized. 3) In the case of solution and aging treatment at $\beta$region, the $\alpha+\beta$type alloy showed the most highest tensile strength and $\beta$type alloy showed the best elongation.

• Journal of the Korean GEO-environmental Society
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• v.10 no.3
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• pp.37-45
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• 2009

The experimental study was carried out to evaluate the characteristics of the point load index and the uniaxial compressive strength of inherently anisotropic shale in the laboratory. In the testing program the effects of size and the shape on the point load index were investigated both in the axial and diametral direction. In general, the point load index of the shale was constant when the length/diameter (L/D) ratio of the specimen is greater than 1.0 in the diametral direction. The point load index in axial direction shows slight decrease as the L/D ratio is increased and the corner breakage was observed when L/D ratio is greater than unity. The minimum point load index was observed in the bedding angle of $\beta=15^{\circ}{\sim}30^{\circ}$ in the axial point load tests and of $\beta=30^{\circ}$ in the uniaxial compression tests. The relationship between the point load index and the uniaxial compressive strength was linear to ${\sigma}_c=25.0 I_{s(50)}$ for the specimen with the bedding plane angle, $\beta$ at the range of $0^{\circ}{\sim}90^{\circ}$. On the other hand, this relationship was appeared linear to ${\sigma}_c=14.4 I_{s(50)}$ when the bedding angle, $\beta$ is fixed to 90${^{\circ}}$ and this correlation is much different from ${\sigma}c=22 I_{s(50)}, which is generally applied to the rock specimen with no bedding plane in ISRM (1985). The anisotropic strength with different $\beta$ angle shows the shoulder type and this can be suitably modelled by the corrected Ramamurthy'(1993)s equation with the index value of 'n' equal to 3.0.

• Journal of the Korea institute for structural maintenance and inspection
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• v.7 no.2
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• pp.239-246
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• 2003

In the PCA Load Contour Method, the biaxial bending design coefficient of columns(${\beta}$) is based on the equivalent rectangular stress block (RSB). And coefficient of ${\beta}$ estimates the reinforcement index to be a influencing parameter on biaxial moment strength of RC columns without considering the arbitrary condition of bar arrangement. The experimental results of high strength concrete (HSC) columns subjected to combined axial load and biaxial bending moment were compared to the analysis results of RSB method. As result, the accuracy of RSB method is still acceptable for HSC columns and, as the reinforcement is placed densely in each corner of column section, the ${\beta}$ is decreased.

• Journal of Korean Society of Steel Construction
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• v.14 no.3
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• pp.403-411
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• 2002

This paper described the ultimate strength and deformation limit of welded T-joints in cold-formed square hollow sections. Previous studies showed that the T-joint has an obvious peak load. with the failure mode of chord-web buckling at a ratio of branch width to chord width ($\beta$) of above 0.8. Similar to a T-joint with chord-flange failure mode, the strength at a certain deformation limit can be regarded as the ultimate strength of a T-joint Based on the experimental results including tests done by Kato and Zhao, the deformation limit was proposed as 3%B for $10.7{\leq}2{\gamma}(B/T){\leq}42.3$ and $0.8{\leq}{\beta}{\leq}1.0$. The strength formula of CIDECT and those of other researchers were also compared with the test results. Finally, the strength formula based on the column buckling was proposed.

• Korean Journal of Materials Research
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• v.16 no.1
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• pp.1-4
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• 2006

Biodegradable $\beta$-tricalcium phosphate ( $\beta$-TCP)/poly(lactide-co-glycolide) (PLGA) composites were synthesized by in-situ polymerization with microwave energy. The influence of the $\beta$-TCP content in $\beta$-TCP/PLGA composites on the molecular weight, crystallinity, microstructure and mechanical properties was investigated. As the molecular weight of composites decreased, the $\beta$-TCP content increased up to 10 wt.%, while the excess addition of the $\beta$-TCP content above 10 wt.% the molecular weight increased with increasing of the $\beta$-TCP content. This behavior would be due to the superheating effect or nonthermal effect induced by microwave energy. It was found that the bending strength and Young's modulus of the $\beta$-TCP/PLGA composites was proportional to the molecular weight of PLGA. The bending strength of the $\beta$-TCP/PLGA composites ranged from 18 to 38 MPa, while Young's modulus was in the range from 2 to 6 GPa.

• Microbiology and Biotechnology Letters
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• v.31 no.2
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• pp.111-116
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• 2003

The xylA gene of Bacillus stearothermophilus No. 236 encoding $\beta$-xylosidase was cloned and sequenced previously. The transcriptional start site of the xylA gene cloned in E. coli was identified to be the guanine (G) by primer extension analysis. This supports that the expression of xylA gene is also directed in the E. coli cells by the previously determined transcription initiation signals, -10 sequence (CATAAT) and -35 sequence (TTGTTA) separated by 12 bp. To increase the expression of $\beta$-xylosidase, firstly the spacer region of xylA promoter was extended from 12 to 17 bp, and then the -10 and -35 elements were converted into their respective consensus sequences. The mutant promoters thus obtained were tested for their activities in both the E. coli and B. subtilis host cells. The change of the length of the spacer region from 12 to 17 bp resulted in a 1.6- and 2.5-fold increase in promoter strength in comparison with the wild type promoter in E. coli and B. subtilis cells, respectively. Also, strength of the promoter with the fourth T to A transversion on its -35 element increased in the transcription level by about 35 times compared with that of wild-type promoter. However, surprisingly the 5' end C-to-T transition of the -10 hexamer showed a 5- to 15-fold reduction in $\beta$-xylosidase activity in both E. coli and B. subtilis. Together, the present data demonstrated that the 5' end nucleotide C of the -10 sequence CATAAT and the fourth nucleotide A of the -35 hexamer are two most critical nucleotides for the promoter activity in the context of the xylA promoter.

• International Journal of Naval Architecture and Ocean Engineering
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• v.4 no.4
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• pp.423-436
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• 2012

Unstiffened plates are integral part of all kinds of structures such as ship and offshore oil platforms. Openings are unavoidable and absolutely reduce the ultimate strength of structures. In this study, the finite element analysis package, ABAQUS, is used to analyze the behavior of unstiffened plate with rectangular opening. The rectangular opening form is divided into two cases. In case1, opening depth is constant, but opening width is varied. Meanwhile, in case2 opening width is fixed and opening depth is varied. Besides, for the two different form opening, the effect of plate slenderness parameter (${\beta}$), opening area ratio (AR) and opening position ratio (PR) on the ultimate strength of plate with opening under axial compression are presented. It has been found that the ultimate strength of plate ofcase1is much more sensitive to the plate slenderness parameter (${\beta}$) and opening area ratio (AR) than that of case2. However, for case1, opening position (PR) almost has no effect on the ultimate strength, whereas, regardingcase2, the influence of opening position (PR) depends on the plate slenderness parameter (${\beta}$). Based on nonlinear regression analysis, three design formulae are not only developed but also approved reasonably for the practical engineering design.

• Journal of Adhesion and Interface
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• v.13 no.4
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• pp.163-170
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• 2012

Although ${\beta}$-cyclodextrin (${\beta}$-CD) has been used as medicine, agrichemical, food, cosmetic, antioxidant, anti-volatile agent, anti-hygroscopic agent, fading-protecting agent, and emulsifier due to its ability to form inclusion complex by enclosing another molecule (guest molecule), it has been restricted in practical application because of its low solubility in water and organic solvent. In this study, ${\beta}$-CD derivative as a new polyol with inclusion characteristics against Bisphenol A and cyclopropane, foaming agent for polyurethane (PU), and with improved solubility was synthesized, characterized and used to formulate rigid PU foam with better thermal conductivity and compressive strength compared to that from commercial polyols.

• Journal of the Korean Ceramic Society
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• v.23 no.3
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• pp.9-14
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• 1986

$\beta$-SiC bonded SiC bodies were prepared from various conditions such as several compositions of(Si+C)/$\alpha$ -SiC ratio and different firing schedules and were respectively investigated compressive strength MOR and mi-crostructure. One firing schedule which produced the specimens that had $\beta$-SiC neck form with the highest strength was selected and experimented by each firing temperature. results obtained are as follows : 1) The amount of (Si+C) for th highest MOR of SiC-(Si+C) sintered body is 20wt% 2) By adding 20wt% content of (Si+C) and heating up to 1, 500 with soaking 3hrs respectively at 1,150$^{\circ}C$ 1,250$^{\circ}C$ 1,350$^{\circ}C$ and 1,400$^{\circ}C$ the highest MOR of fired specimen was resulted and its microstructure of ma-trix was composed of close $\beta$-SiC neck. 3) Microstructure of $\beta$-SiC were different greatly from each other by firing time and/or quantity of adding mix-ture and it was confirmed that they were composed of neck particle-like and heterogeneous texture. 4)$\beta$-SiC synthesis proceed rapidly at the temperature between 1,250$^{\circ}C$ and 1,350$^{\circ}C$ 5) All of the properties of 85 SiC-20(Si+C) specimen improved according to increasing temperature above 1,350$^{\circ}C$.