• Title/Summary/Keyword: type specimens

Search Result 2,190, Processing Time 0.034 seconds

A considerable review on type specimens of Korean vascular plants in the Herbarium of the Komarov Botanical Institute (LE) Addition

  • Grabovskaya-Borodina, Alisa E.;Illarionova, Irina D.;Jang, Hyun-Do;Lee, Byoungyoon;Suh, Min Hwan;Park, Jeong Mi
    • Journal of Species Research
    • /
    • v.7 no.1
    • /
    • pp.73-79
    • /
    • 2018
  • The review provides the information about 46 type specimens on 35 taxa of vascular plants from Korea (Fig. 1), kept in the Herbarium of the Komarov Botanical Institute of the Russian Academy of Sciences in addition to 150 taxa published before. Lectotype of Ligustrum patulum Palib is designated here.

Mechanical Properties Anisotropy of Plain Weave Glass Fabric Reinforced Epoxy Resin Laminates (평직유리섬유강화 에폭시 적층판의 기계적 특성 이방성)

  • Kim, Yon-Jig
    • Transactions of the Korean Society of Automotive Engineers
    • /
    • v.17 no.3
    • /
    • pp.15-21
    • /
    • 2009
  • The anisotropic mechanical properties were measured for the three orthogonal orientations of plain weave glass fabric reinforced epoxy resin laminate. In tensile and flexural tests, axial and edge type specimens failed by pull-out of warp and fill yarns, respectively. In contrast, the thickness type specimens failed by adhesive failure process. Longitudinal cracking occurred in several of the edge type specimens during tensile test. That cracking caused pop-in in the stress-strain curve. Defects induced by improper coupon machining caused that cracking.

Microphysogobio tungtingensis uchidai, a Junior Synonym of M. yaluensis (Pisces, Cyprinidae) (돌마자 M. yaluensis (어상강, 잉어과)의 동종이명, Microphysogobio tungtingensis uchidai)

  • Ik-Soo Kim;Hyun Yang
    • Animal Systematics, Evolution and Diversity
    • /
    • v.16 no.2
    • /
    • pp.159-163
    • /
    • 2000
  • The gudgeon, Microphysogobio tungtingensis uchidai, originally described by Banarescu and Nalbant in 1973 is reduced to a junior synonym of M. yaluensis based on the 5 type specimens in the USNM. Confusion on the taxonomic position of Microphysogovbio t. uchidai seems to have resulted from the inadequate description of the papillae of the upper lip and the reference to the small specimens.

  • PDF

High Temperature Tribological Behaviors of Nitride Based Ceramic Coatings (나이트라이드계 세라믹 코팅의 고온 마모, 마찰거동)

  • 김장엽;임대순;이상로;백운승
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
    • /
    • 1996.05a
    • /
    • pp.83-86
    • /
    • 1996
  • In this study, CrN, TiN and TiN + CrN coatings have treated onto the steel substrates by ion plating to improve their tribological behaviors. Some of the specimens were ion nitriding treated to study the effect of ion nitriding on wear behavior. The wear tests were performed with these specimens by ball-onplate type and disc-on-plate type wear tester. It was demonstrated that ion nitriding treatment improve wear resistance of the coatings. The results of high temperature wear tests indicated that the specimens coated with CrN were exhibited the better wear resistance properties than the specimens with TiN coatings

  • PDF

A Study on the Fatigue Characteristics and the Behavior of Crack Propagation by Overload and Bending Moment in Car Body Structure (차체구조물에서 면내 굽힘모우멘트 및 과하중이 피로특성과 균열전파 거동에 미치는 영향에 관한 연구)

  • 성기찬;장경복;정진우;강성수
    • Journal of Welding and Joining
    • /
    • v.19 no.6
    • /
    • pp.652-657
    • /
    • 2001
  • To analyze and predict crack initiation position and propagation directions on the spot welded area are very important for strength design of the automobile body structure. It is necessary to test by method considering random loads with variable amplitude for strength design of vehicle body structure, because driving cars are actually subjected to random loads with variable amplitude in the road. Although this condition, nearly all tests haute been performed under constant load conditions in the laboratory because it is impossible to replay like an actual conditions. In this study, using in-plane bending type specimens, the overload factor affecting on the fatigue strength, crack initiation and propagation directions of spot-welded specimens have been studied.

  • PDF

Mechanical performance of additively manufactured austenitic 316L stainless steel

  • Kim, Kyu-Tae
    • Nuclear Engineering and Technology
    • /
    • v.54 no.1
    • /
    • pp.244-254
    • /
    • 2022
  • For tensile tests, Vickers hardness tests and microstructure tests, plate-type and box-type specimens of austenitic 316L stainless steels were produced by a conventional machining (CM) process as well as two additive manufacturing processes such as direct metal laser sintering (DMLS) and direct metal tooling (DMT). The specimens were irradiated up to a fast neutron fluence of 3.3 × 109 n/cm2 at a neutron irradiation facility. Mechanical performance of the unirradiated and irradiated specimens were investigated at room temperature and 300 ℃, respectively. The tensile strengths of the DMLS, DMT and CM 316L specimens are in descending order but the elongations are in reverse order, regardless of irradiation and temperature. The ratio of Vickers hardness to ultimate tensile strength was derived to be between 3.21 and 4.01. The additive manufacturing processes exhibit suitable mechanical performance, comparing the tensile strengths and elongations of the conventional machining process.

Stress relaxation effect on uniaxial compressive strength values of a silt type soil

  • Eren Komurlu
    • Geomechanics and Engineering
    • /
    • v.32 no.5
    • /
    • pp.495-502
    • /
    • 2023
  • In this study, stress relaxation tests were carried out by keeping silt type soil specimens under different strain levels. Decreases in the stress values with time data was collected to better understand the effect of the strain level on the relaxation properties of soil specimens. In addition, the stress relaxation effect on the uniaxial compressive strength (UCS) values of the specimens was investigated with a series of tests. According to the results obtained from this study, the UCS values of the silt specimens significantly vary as a result of the stress relaxation effect. The UCS values were determined to increase with an increase of relaxation strain level to a threshold value. On the other hand, the UCS values were found to be affected adversely in case of high stress levels at the initiation of the relaxation, which are close to the peak level.

AN ELECTROCHEMICAL STUDY ON SURFACE FINISH OF DENTAL AMALGAM (아말감의 표면연마에 관한 전기화학적 연구)

  • Suk, Chang-In;Um, Chung-Moon
    • Restorative Dentistry and Endodontics
    • /
    • v.16 no.2
    • /
    • pp.18-32
    • /
    • 1991
  • The purpose of this study was to observe characteristic properties of amalgam through the polarization curves and SEM images from 4 type amalgams (Amalcap, Shofu spherical. Dispersalloy and Tytin) with 3 different surface finish procedures (polishing, burnishing and carving) by using the potentiostats (EG & GPARC) and SEM (Jeol JSM-35). After each amalgam alloy and Hg was triturated as the direction of the manufacturer by means of mechanical amalgamator (Samki), the triturated mass was inserted into the cylndrical metal mold which was 12 mm in diameter and 10 mm in height and was pressed with $100kg/cm^2$. 4 specimens of each type amalgam were burnished with egg burnisher and another 4 specimens of each type amalgam were carved with Hollenback carver. Above 8 specimens and remaining untreated 4 specimens were stored at room temperature for about 7 days. Untreated 4 specimens of each type amalgam were polished with abrasive papers (Deer) from #400 to #1200 and finally on the polishing cloth with $0.5{\mu}m$ and $0.06{\mu}m$ $Al_2O_3 $ powder suspended water. Anodic polarization measurements was employed to compare the corrosion behaviours of the amalgams in 0.9% saline solution at $37^{\circ}C$. The open circuit potential was determined after 30 minutes immersion of specimen in electrolyte. The scan rate was 1 mV/sec and the surface area of amalgam exposed to the solution was $0.64cm^2$ for each specimen. All the potentials reported are with respect to a saturated calomel electrode (SCE). SEM images of each specimen were taken after + 800 mV (SCE) polarization. The results were as follows: 1. The corrosion potential of high copper amalgam was more anodic than that of low copper amalgam. 2. The polished amalgam were more resistant to corrosion than any other burnished and carved amalgam. 3. In the case of polishing, current density of high copper amalgam was lower than that of low copper amalgam.

  • PDF

Evaluation of Structural Performance of Flat Plate-Column Interior Connections with Folded Bend Shear Reinforcement (밴드형 전단보강근으로 보강된 무량판 슬래브 내부접합부의 구조 거동 평가)

  • Lee, Bum-Sik;Park, Seong-Sik;Park, Ji-Young;Bang, Jong-Dae;Jun, Myoung-Hoon;Cho, Gun-Hee
    • Land and Housing Review
    • /
    • v.4 no.4
    • /
    • pp.371-382
    • /
    • 2013
  • This study performs an experimental investigation to evaluate the behavior of RC flat plate interior joints specimens. Three 60 percent scale Flat Plate interior specimens assemblies representing a portion of a Flat Plate Apartment Structural System subjected to simulated seismic loading (unbalanced moments) under constant axial load were tested, including one specimens with ordinary shear reinforcement and two specimens with folded bend type shear reinforcement. Test results are shown that (1) the design code KBC 2009 is accurate estimate the behavior of specimens. (2) Two types shear reinforcement have a similar structural behavior, but construction work of rebar with folded bend type shear reinforcement is easier than that of ordinary shear reinforcement. (3) In moderate seismic region, RC Flat Plate interior joint with folded bend type shear reinforcement is apply to structural design of Flat Plate.

The Effects of the Seam Type on Fabric Drape (솔기 유형이 직물의 드레이프성에 미치는 영향)

  • Paeng, Suk-Kyung;Jeong, Su-Jin;Chu, Mi-Seon
    • Fashion & Textile Research Journal
    • /
    • v.13 no.3
    • /
    • pp.418-424
    • /
    • 2011
  • The purpose of this study was to reveal the effects of the seam type on the fabric drape to provide the basic knowledge for proper seam type according to the design of sewing products. Seven kinds of specimens were constructed with seam (no seam, welt seam with over-edged finish, welt seam with bias bound finish, plain seam with over-edged finish, plain seam with bias bound finish, french seam, and flat fell seam) in wrap direction of the fabric. Using a drape measurement system involving two 18 cm diameter supporting disks, and a digital camera, the images of draped specimens were captured and processed. Drape behavior was evaluated in terms of drape coefficient, node number, and drape profile. Significant differences were found in drape coefficient by the seam types. The specimens with french seam and flat fell seam showed higher drape coefficients compared to those with welt seam and plain seam. Node numbers in the drape profiles showed positive correlation with the weight of the specimens, however, no significant differences were observed in node numbers by the seam types. Significant differences were found in the length of the seamed part by the seam types. The specimens with french seam and flat fell seam showed longer length of the seamed part compared to those with welt seam and plain seam. The ratio of the maximum length in the seam direction to the maximum length perpendicular to the seam direction showed significant differences by the seam types.