• Steel and Composite Structures
• /
• v.52 no.6
• /
• pp.627-645
• /
• 2024

Punching shear is a brittle failure that occurs within the RC flat slabs where stresses are concentrated within small regions, resulting in a catastrophic and unfavorable progressive collapse. However, increasing the slab slenderness ratio is believed to significantly affect the slab's behavior by the induced strain values throughout the slab depth. This study examines the punching shear behavior of flat slabs by the nonlinear finite element analysis approach using ABAQUS software, where 72 models were investigated. The parametric study includes the effect of opening existence, opening-to-column ratio (O/C), temperature level, slenderness ratio (L/d), and flexural reinforcement rebar diameter. The behavior of the punching shear failure was fully examined under elevated temperatures which was not previously considered in detail along with the combined effect of the other sensitive parameters (opening size, slab slenderness, and reinforcement rebar size). It has been realized that increasing the slab slenderness has a major role in affecting the slab's structural behavior, besides the effect of the flexural reinforcement ratio. Reducing the slab's slenderness from 18.27 to 5.37 increased the cracking load by seven times for the slab without openings compared to nine times for the initial stiffness value. In addition, the toughness capacity is reduced up to 80% upon creating an opening, where the percentage is further increased by increasing the opening size by about an additional 10%. Finally, the ultimate deflection capacity of flat slabs with an opening is increased compared to the solid slab with the enhancement being increased for openings of larger size, larger depths, and higher exposure temperature.

• Journal of Sensor Science and Technology
• /
• v.3 no.1
• /
• pp.68-77
• /
• 1994

Grid type 70Ni-30Co thin films on slide glass at $250^{\circ}C$ has been fabricated to develope. From fabricated sensors using above process, we investigated the relation of temperature, resistivity, line width to magnetoresistance and we obtained the following results after observation of coercive force, saturated magnetization, maxium usable sensitivity, delay time, slew rate, white noise, resolution of the sensors. We confirmed that the $600{\AA}$ thin film at $250^{\circ}C$ formed crystalized magnetic anisotropy spontaneously and the sensor using the thin film had capability of detecting magnetic field with sensitivity of 230 nT. In these devices, the magnetoresistance change was increased linearly in ${\pm}10$ Oe range, and the magnetoresistance effect was increased when the ratio between line width and length was increased. When the devices was soldered using indium, the temperature-resistivity coefficient showed $8{\times}10^{-3}/deg$ and increased during the specific properties as magnetic field sensor were weakened. In this studies, the coercive forces of the films were about 5.1 A/cm and saturated magnetizations were 0.64 T, and the delay time in these devises was $5{\mu}s$ and slew rate showed 0.39 $Oe/{\mu}s$ and white noise was -120 dB.

• Korean journal of food and cookery science
• /
• v.10 no.2
• /
• pp.99-103
• /
• 1994

The purpose of this study was to investigate the sensory and physicochemical properties of jatjook(rice gruel cooked with pinenut) containing various levels of pinenut. For this purpose, the various methods and recipe of Jatjook appeared in the literatures were evaluated to select the most preferable Jatjook. Chemical composition of Jatjook containing various levels of pinenut were 69.75∼83.04% of moisture, 2.25∼4.85% of crude protein, 1.77∼ 13.09% of crude fat, and 0.13∼0.51% of ash. C18-2,(linoleic acid) was the highest in the fatty acid contents of jatjook. Vitamin I contents of jatjook were 0.50∼3.50mg/100g. By the color difference meter, the values of L(lightness) and b(yellowness) were increased by increasing the amount of pinenuts, whereas the value of a(redness) showed negative value by increasing the amount of pinenut. Viscosity of Jatjook was decreased by increasing the amount of pinenut. As a result of the sensory evaluation fo. Jatjook made with various levels of pinenut, Jatjook having mixture ratio of 1 rice, 1 pinenut, and 5 water was the most preferable.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.33 no.4
• /
• pp.668-678
• /
• 2004

The purpose of this study was to estimate seasonal variation of nutritional intake and quality in adults in longevity areas. Dietary survey was given to 469 subjects over age 20 living Bukjeju-gun, Yecheon-gun, and Sunchang-gun of Korea, using 24-hour recall method every 4 seasons over one-year period. The mean daily intakes (%RDA) of 4 seasons were 1313.3 ㎉ (72.0%) for energy, 47.3 g (82.2%) for protein, 20.2 g for fat, 228.0 g for carbohydrate, 12.8 g for dietary fiber. The differences were hardly significant among the seasons. Mean daily intakes of most of the vitamins and minerals were lower than RDA except vitamin C and folate, especially %RDAs of Ca, vitamin D, vitamin B$_2$, vitamin E were less than 60% of RDA. In general, nutrient intake were high in spring compared to other seasons except vitamin C which was high in fall and winter. Mean daily intakes of cholesterol were 151.7 mg and 124.3 mg in males and females, respectively. The differences was significant between the two sexes but not among the seasons. PUFA : MUFA : SFA ratio of the subject was 1.0 : 1.3 : 1.2. Average CPF ratio of energy intake was 72.7 : 14.4 : 12.9, and energy intake ratio from carbohydrate was low in spring, in contrast energy intake ratios from protein was significantly high in spring. Mean adequacy ratio (MAR), an index of overall nutritional quality was 0.64 for female and 0.71 for male. The indices of nutritional quality (INQ) were over 1 for most of nutrients except 0.73 of Ca, 0.87 of vitamin A, 0.69 of vitamin B$_2$, and 0.65 of vitamin E. Both MAR and INQ were significantly different among sex and seasons, values were higher in males than in females and were higher in spring with the exception of vitamin C. In conclusion, subjects in longevity areas did not consume enough nutrients quantitatively as well as qualitatively, especially Ca, vitamin A, vitamin B$_2$, and vitamin E. Also mean daily intakes of most of vitamins and minerals were insufficient in females, and were significantly different among season. Therefore we must consider a counterplan to augment nutrition intake for them. In addition, it seems to be essential to micro nutrients to the food composition database to estimate dietary intakes more accurately.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.12 no.4
• /
• pp.395-400
• /
• 1983

The experiment was conducted to study the effect of protein level on weight gain, feed consumption and the efficiencies of feed, energy and protein when the broiler chick was fed the diet of different protein level with the iso-calorie content. The energy and protein level of the basal ration was 3200 kcal and 22.85% for starter period and 3265 Kcal and 18.58% for finisher period, respectively. In order to increase the protein level of the experimental diet, the basal diet was substituted by fish meal by the ratio of 3, 6, 9, and 12%. The male Abor Acre broiler chicks were employed for 8 weeks and the result obtained were as follows. 1. The weekly body weight gain was significantly greater for Diet C than for Diet A and E in the starter period and greater for Diet A than for Diet E in the finisher period (P<0.05). 2. In stater period the feed intake was not affected by the protein level but in finisher period the feed intake for Diet C, D, and E was significantly reduced compared with Diet A. 3. As for feed conversion ratio, Diet C of 1.43 was improved significantly compared with Diet A of 1.58(P<0.05). 4. As the protein level of diet increased, the energy efficiency ratio increased and however, the protein efficiency ratio decreased in starter and finisher period. In conclusion the best performance of broiler is thought to be realized when the protein and energy level was 23% and 3200 Kcal for starter period and 20% and 3250 Kcal for finisher period, respectively.

• Journal of Welding and Joining
• /
• v.32 no.4
• /
• pp.46-54
• /
• 2014

In this study, the effect of bonding temperature and bonding pressure on deformation and tensile properties of diffusion bonded joint of STS304 compact heat exchanger was investigated. The diffusion bonds were prepared at 700, 800 and $900^{\circ}C$ for 30, 60 and 90 min in pressure of 3, 5, and 7 MPa under high vacuum condition. The height deformation of joint decreased and the width deformation of joint increased with increasing bonding pressure at $900^{\circ}C$. The ratio of non-bonded layer and void observed in the joint decreased with increasing bonding temperature and bonding pressure. Three types of the fracture surface were observed after tensile test. The non-bonded layer was observed in diffusion bonded joint preformed at $700^{\circ}C$, the non-bonded layer and void were observed at $800^{\circ}C$. On the other hand, the ductile fracture occurred in diffusion bonded joint preformed at $900^{\circ}C$. Tensile load of joint bonded at $800^{\circ}C$ was proportional to length of bonded layer and tensile load of joint bonded at $900^{\circ}C$ was proportional to minimum width of pattern. The tensile strength of joint was same as base metal.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2015.08a
• /
• pp.109.2-109.2
• /
• 2015

Graphene, as a single layer of $sp^2$-bonded carbon atoms packed into a 2D honeycomb crystal lattice, has attracted much attention due to its outstanding properties such as high carrier mobility, chemical stability, and optical transparency. In order to synthesize high quality graphene, transition metals, such as nickel and copper, have been widely employed as catalysts, which need transfer to desired substrates for various applications. However, the transfer steps inevitably induce defects, impurities, wrinkles, and cracks of graphene. Here, we report a facile transfer-free graphene synthesis method through nickel and carbon co-deposited layer, which does not require separately deposited catalytic nickel and carbon source layers. The 100 nm NiC layer was deposited on the top of $SiO_2/Si$ substrates by nickel and carbon co-deposition. When the sample was annealed at $1000^{\circ}C$, the carbon atoms diffused through the NiC layer and deposited on both sides of the layer to form graphene upon cooling. The remained NiC layer was removed by using nickel etchant, and graphene was then directly obtained on $SiO_2/Si$ without any transfer process. Raman spectroscopy was carried out to confirm the quality of resulted graphene layer. Raman spectra revealed that the resulted graphene was at high quality with low degree of $sp^3$-type structural defects. Furthermore, the Raman analysis results also demonstrated that gas flow ratio (Ar : $CH_4$) during the NiC deposition and annealing temperature significantly influence not only the number of graphene layers but also structural defects. This facile non-transfer process would consequently facilitate the future graphene research and industrial applications.

• Progress in Superconductivity and Cryogenics
• /
• v.6 no.3
• /
• pp.16-20
• /
• 2004

YB $a_2$C $u_3$$O_{7-x}$ (YBCO) films were deposited on (100) SrTi $O_3$ single crystal substrates by a metal organic chemical vapor deposition (MOCVD) system of hot-wall type using single liquid source. Under the condition of the mole ratio of Y(tmhd)$_3$:Ba(tmhd)$_2$:Cu(tmhd)$_2$= 1:2.1:2.9. the deposition pressure of 10 Torr. the MO source line speed of 15 cm/min. the Ar/ $O_2$ flow rate of 800/800 sccm. YBCO films were prepared at the deposition temperatures of 780∼89$0^{\circ}C$. In case of the YBCO films with 2.2 ${\mu}{\textrm}{m}$ thickness deposited for 6 minutes at 86$0^{\circ}C$. XRD pattern showed complete c-axis growth and SEM morphology showed dense and crack-free surface. The atomic ratios of Ba/Y and Cu/Ba in the film were 1.92 and 1.56. respectively. The deposition rate of the film was as high as 0.37 ${\mu}{\textrm}{m}$/min. The critical temperature ( $T_{c.zero}$) of the film was 87K. The critical current of the film was 104 A/cm-width. and the critical current density was 0.47 MA/$\textrm{cm}^2$. For the thinner film of 1.3 ${\mu}{\textrm}{m}$ thickness. the critical current density of 0.62 MA/$\textrm{cm}^2$ was obtained.d.

• Food Science of Animal Resources
• /
• v.31 no.5
• /
• pp.693-700
• /
• 2011

To evaluate the antioxidant effects of vitamin C, vitamin E and sorghum bran, alone or in combination on chicken sausages, 9 kg of chicken thigh meat was prepared. All thigh meat was divided into seven different batches as follows; no antioxidant (CON); vitamin C (VTC), vitamin E (VTE) or sorghum bran (SOR) at 0.02%; or three different combination ratios of vitamin C, vitamin E and sorghum bran at 0.02% (VT2, 2:1:1; VT4, 4:1:1; VT6, 6:1:1). All cooked sausages were stored at $4^{\circ}C$, and six sausages per treatment were used for chemical analysis on five different storage days. As the addition of vitamin E was increased, sausages stored for 10 d had decreased redness; thereby, VTE showed the lowest CIE $a^*$ (p<0.05). Sausages mixed with vitamins and sorghum bran combinations had lower peroxide and free fatty acid values (p<0.05) when compared to sausages without antioxidants. The TBARS were the lowest in sausages containing vitamin C, vitamin E and sorghum bran at 6:1:1 ratio, and they significantly differed to CON, VTC and SOR treatments (p<0.05). Therefore, our results suggest that meat mixed with vitamins and sorghum bran had more antioxidant activity than the meat mixed with only antioxidant vitamins or without antioxidants.

• Annals of Clinical Neurophysiology
• /
• v.16 no.2
• /
• pp.55-61
• /
• 2014

Background: Viruses can cause either meningitis or encephalitis. It is unclear why some people suffer from aseptic meningitis, and others acquire aseptic encephalitis when infected with the same viral pathogens. The aim of this study was to compare demographic and laboratory factors between patients with aseptic meningitis and encephalitis. Methods: The demographic and laboratory differences were analyzed according to age, sex, diabetes, hypertension, C-reactive protein in the blood, white blood cell and protein in the cerebrospinal fluid, and glucose ratio (cerebrospinal fluid/blood). Additionally, we analyzed the nation-wide differencesin age between the patients with aseptic meningitis and those with encephalitis in Korea. Results: The patients with aseptic encephalitis were older, more likely to have hypertension, and had higher levels of C-reactive protein than did the patients with aseptic meningitis. However, the numbers of white blood cells in the cerebrospinal fluid were significantly higher in the patients with meningitis than in the patients with encephalitis. Multivariable analysis revealed that age >49 years, hypertension and a C-reactive protein level >5.81 mg/dL were independent and significant variables in the prediction of aseptic encephalitis. Additionally, the patients with aseptic encephalitis were older than those with aseptic meningitis in the nation-wide Korean database. Conclusions: Older age, hypertension, and higher levels of C-reactive protein are useful factors for the prediction of aseptic encephalitis.