• Journal of computational fluids engineering
• /
• v.11 no.1 s.32
• /
• pp.1-7
• /
• 2006

Numerical investigation of a centrifugal compressor volute having a modified straight conical duct hill been made. Three-dimensional Reynolds-Averaged Navier-Stokes equations with $k-{\varepsilon}$ turbulence equation are solved To avoid coordinate singularity at the central axis of the duct, multi-block H-type grid is generated on the circular cross-sections of the volute and stretched toward the solid wall boundary. We obtained numerical results with three different mass flow rates at the volute inlet, namely, with the inlet conditions that give small, medium and large mass flow rates at the outlet of the conical duct. Agreement with the experimental results is observed.

• The Journal of Advanced Prosthodontics
• /
• v.1 no.1
• /
• pp.19-25
• /
• 2009

STATEMENT OF PROBLEM. Primary stability at the time of implant placement is related to the level of primary bone contact. The level of bone contact with implant is affected by thread design, surgical procedure and bone quality, etc. PURPOSE. The aim of this study was to compare the initial stability of the various taper implants according to the thread designs, half of which were engaged to inferior cortical wall of type IV bone(Group 1) and the rest of which were not engaged to inferior cortical wall(Group 2) by measuring the implant stability quotient(ISQ) and the removal torque value(RTV). MATERIAL AND METHODS. In this study, 6 different implant fixtures with 10 mm length were installed. In order to simulate the sinus inferior wall of type IV bone, one side cortical bone of swine rib was removed. 6 different implants were installed in the same bone block following manufacturer s recommended procedures. Total 10 bone blocks were made for each group. The height of Group 1 bone block was 10 mm for engagement and that of group 2 was 13 mm. The initial stability was measured with ISQ value using Osstell $mentor^{(R)}$ and with removal torque using MGT50 torque gauge. RESULTS. In this study, we found the following results. 1. In Group 1 with fixtures engaged to the inferior cortical wall, there was no significant difference in RTV and ISQ value among the 6 types of implants. 2. In Group 2 with fixtures not engaged to the inferior cortical wall, there was significant difference in RTV and ISQ value among the 6 types of implants(P < .05). 3. There was significant difference in RTV and ISQ value according to whether fixtures were engaged to the inferior cortical wall or not(P < .05). 4. Under-drilling made RTV and ISQ value increase significantly in the NT implants which had lower RTV and ISQ value in Group 2(P < .05). CONCLUSIONS. Without being engaged to the inferior cortical wall fixtures had initial stability affected by implant types. Also in poor quality bone, under-drilling improved initial stability.

• Proceedings of the SAREK Conference
• /
• 2009.06a
• /
• pp.603-607
• /
• 2009

About a Structure is performance external insulation is fundamantal performance for enrgy-saving. these day, most of residential structures have constructed by internal insulation method structure. The method structure internal insulation have construction and economical efficiency, but on the other hand, be generated heat loss by heat bridge especially, be generated loss heat-energy logical consequence in structure ondol. The external insulation structure method has a mert able to minimum to loss heat about heat-bridge. But the external insulation technique is unsatisfactory statues within the know-how and method of construction and materials compared with developed countries. The recently, the requirement of market related to the external insulation technique is resulted by the energy efficiency system, but it can lead to the lack of alternative technique In study on the korea type passive house building design for insulation block method of wall system has to experimental characteristic heat-energy of practice building. In result field-experimental, the heat-bridge appeared to characteristic spent heat-energy of blow 2L class and have a suffience performance it.

• Journal of the Korean Geotechnical Society
• /
• v.30 no.4
• /
• pp.47-63
• /
• 2014

In this study theories of earth pressure such as Rankine, Coulomb, Trial Wedge, Improved Trial Wedge, used in the design for onshore and offshore structures, are analyzed and the characteristics of loaded pressure to virtual back (wall, plane) and wall surface in accordance with the structure type are suggested. To investigate characteristics of earth pressure, gravity retaining wall with inclined angle and cantilever wall with inclined ground are movilized for onshore structures and caisson and block type quay wall are mobilized for offshore structures. Based on various theories, the earth pressure applied angle(wall friction angle) and sliding angle toward the wall, which is influenced by the heel length, are calculated and compared. In the case of long heel, the pressure by Rankine's method in virtual plane and the mobilized angle are most reasonably estimated by the ground slope, and in the case of short heel, the pressure by Coulomb's method and the mobilized angle by the angle of wall friction. In addition, the sliding angle toward the wall estimated by the improved trial wedge method is large than the value of Rankine's method. Finally, in this study the reasonable method for calculating the pressure and the mobilized angle that can be applied to the routine design of port structures is proposed. The proposed method can decide the earth pressure with length of a heel and a self weight of retaining wall according to sliding angle toward the wall.

• Journal of Korean Society of Rural Planning
• /
• v.18 no.1
• /
• pp.17-28
• /
• 2012

Functional mismatch and thought and plan-less material use of recently built boundary barriers in rural areas should greatly degrade their amenity value as one of linear villagescapes, but, their present state-of-art basically necessary for problem-solving had never surveyed up to now. From this point of view, this study tried to investigate present stock quantities and qualities of boundary barriers in rural areas by sample studies on 21 case villages(7 types ${\times}$ 3 cases) and comparative analysis between the planned or improved and nots. Wall type was absolutely dominated in the structural terms, of which more than half was used cement block as building material and, therefore, grey-colored. More than half of total barrier length were fully shielded, while relatively partially shielded in the mountainous villages in open space and 'Cultural villages' with closed housing structures. Free standing style of barriers was shown along over two thirds of their total length, although not more than half in planned reclaimed villages. Especially, because of one-sided wall type structure, mismatched over-shieldness and poorer maintenance condition of the boundary barriers in peri-urban villages, there should be provided with very intensive improvement efforts for amenity barriers.

• Journal of the Korean Geosynthetics Society
• /
• v.6 no.1
• /
• pp.27-32
• /
• 2007

This paper describes the applicability of geogrid with I-type coupling system, which permits vertical displacement on back fill ground of the reinforced retaining wall and also minimize the damage between block and geogrid. The improvement of coupling method allowed the reduction of approximately 700 mm in the existing geogrid, and as a result, the tensile strength at the coupling joint showed approximately 53% of the maximum tensile strength. It is expected from the laboratory investigations that the coupling strength of geogrid with the combination of in-situ supporting material should be predominant in the field condition.

• Journal of Periodontal and Implant Science
• /
• v.41 no.6
• /
• pp.285-292
• /
• 2011

Purpose: The aim of this study was to elucidate the effect of a bovine hydroxyapatite/collagen (BHC) block in one-wall intrabony periodontal defects in dogs. Methods: A one-wall intrabony periodontal defect (4 mm wide and 5 mm deep) was prepared bilaterally at the mesial side of the mandibular fourth premolar in five beagle dogs. After thorough root planing, block-type BHC ($4{\times}5{\times}5$ mm) was placed on one side. The contralateral defect area did not receive any material as a sham-surgery control. Histological analysis of the sites was performed after an 8-week healing period. Results: Two of five samples in the experimental group healed well without dissipation of the graft materials, and histological analysis revealed excellent regeneration of the periodontal tissues. However, most of the grafted materials had been displaced in the other three samples, leaving only a small portion of the graft. The measured parameters exhibited large standard deviations, and the mean values did not differ significantly between the experimental and sham-surgery control sides. Conclusions: The application of BHC alone-without a barrier membrane-to wide, one-wall intrabony periodontal defects yielded inconsistent results regarding both periodontal regeneration and substantivity of the graft materials. Thus, the use of a barrier membrane for noncontained-type defects is recommended to improve the stability of the grafted material, and to condense it.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.56 no.6
• /
• pp.75-84
• /
• 2014

This study aims to develop the program for design of a reinforced earth retaining wall. For this purpose, the external stability such as overturning, sliding and bearing capacity and the internal stability such as pull-out failure and tensile rupture of the reinforced earth retaining wall with the reinforcement spacing and the backfill inclination were examined. In addition, the calculated results from the developed program were verified by comparing with the simulated results based on the three-dimensional finite element analysis. It is expected that this program contributes to effective design of the reinforced earth retaining wall.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.42 no.1
• /
• pp.1-9
• /
• 2022

Semi-integral abutment bridges are a type of integral abutment bridges. These bridges eliminate expansion joints on the structure and can be used in situations not suitable for full-integral abutment bridge. Moreover, Semi-integral bridges have excellent maintenance and can be economically constructed. This study is about precast wall-type blocks at each end which provide lateral support for PSC girder, as well as acting as retaining walls to resist longitudinal movement of semi-integral abutment bridge. The end-diaphragm connection between ended blocks of PSC girders can be achieved by in-suit nonshrinkage concrete. The results show that 3-point experiment of end-diaphragm beam have an acceptable performance which is so better than results of structural design. Moreover, the effects of backfill soil on semi-integral abutment bridge constructed are analyzed the behavior according to the temperature changes.

• Asian-Australasian Journal of Animal Sciences
• /
• v.10 no.1
• /
• pp.47-53
• /
• 1997

Appropriation of partial substitution of concentrate mixture by urea-molasses-mineral block (UMMB) lick supplements for 20 lactating crossbred cows in 2nd and 3nd lactation was studied. Animals fed on wheat straw ad lib. and Berseem (Trifolium alaxandrium) fodder @ 1.5 kg/d on dry matter basis. Animals of control group were given concentrate supplement, while in treatment groups 10% of the concentrate requirement was substituted with 3 different types of UMMB lick type A ($T_1$), type B ($T_2$) and type C ($T_3$). CP content of the ration was 15%. Total dry matter intake (DMI) was about 1.0 kg/kg of fat corrected milk (FCM) yield and was not significantly different between control and treatment groups. Digestibility of neither proximate principles nor cell wall constituents were deviated on UMMB licks partial supplementation. FCM yield was increased by 140, 410 and 460 g/d, in $T_1$, $T_2$ and $T_3$, respectively, in comparison to control group but differences were statistically invalid. Though fat per cent was reduced, fat yields were remain constant among treatments. Milk composition was unaltered except significant difference (p < 0.01) in non-protein nitrogen (NPN) content. Gross-N and digestible-N conversion was significantly higher (p < 0.01) with $T_1$, $T_2$ and $T_3$ than control group. Energy utilization efficiency for milk production was only 36%. Result demonstrated that UMMB licks could be partial supplemented up to 10% of the concentrate requirement of crossbred cows yielding on an average 14kg/d without any adverse effect on feed intake, nutrient utilization and mild production. Comparatively, UMMB lick type B and C was proved better than type A and also economically viable.