• The Korean Journal of Malacology
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• v.23 no.1
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• pp.9-16
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• 2007

Data obtained from field observation revealed that the degree of shell bioerosion of the scallop, Patinopecten (Mizuhopecten) yessoensis, by endolithic organisms significantly higher on the muddy sand than on the sand. At the area studied, the polychaete worm, Polydora brevipalpa (=Polydora ciliata brevipalpa, Polydora ciliata Okuda, Not Johnston, Polydora variegata), which is common symbiotic species for the scallop made 95-100% of total scallop shell bioerosion at the area studied. The muddy bottom sediments enriched by organic matter create favourable conditions for development of microphytobenthos and bacteria, which are predominantly consumed by P. brevipalpa. Linear regressions for the degree of shell bioerosion on the scallop shell height, total wet weight and adductor muscle wet weight revealed negative relationships between them for the scallops inhabiting both sand and muddy sand. The influence of polychaetes on scallops is complex. They may be food competitors. Polychaete can directly affect the host through their boreholes. Scallop expends energy for shell regeneration to prevent the polychaete penetration into its interior cavity. It was found that the degree of shell bioerosion increased considerably with scallop age.

• International Journal of Naval Architecture and Ocean Engineering
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• v.7 no.2
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• pp.315-323
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• 2015

The weld scallop has been used for joining T-bars. There are a lot of weld scallops in shipbuilding. It is difficult to perform scallop welding due to the inconvenient welding position. This results in many problems such as porosity, slag inclusion, etc. In this study, a new method is devised to remove weld scallops by incorporating a Ceramic Backing Material (CBM). The weld scallop is removed by an elongation of the v groove. In order to insert a CBM into the groove without a weld scallop, a wedge-shaped CBM is developed. The top side of the developed CBM is similar to the shape of a general back bead. The bottom surface has a saw-toothed shape for cutting at a suitable length. This can be attached to the root side of a face plate using adhesive tape, just like a general CBM. Welding experiments in normal and abnormal conditions are carried out and the possibility of burn-through is examined. This CBM's applicability to shipbuilding is verified.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.331-336
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• 2001

Aragonite type of precipitated calcium carbonate was synthesized by the successive reaction with hybridization of waste scallop shells with limestone. In the first step, carbonation was performed by using calcined limestone with low brightness, followed by the additional carbonation using calcined-hydrous scallop shells with high brightness. The temperature and the amount ratio of calcined limestone to calcined-hydrous scallop shells were examined as parameters in the experimental conditions. The products were characterized by XRD, SEM. in addition to measurements of brightness index. the specific surface area, and bulk density. The amount ratio of limestone to scallop shell affected not only the brightness but also morphologies of products. The increase in relative amounts of limestone leads to decrease in brightness and bumpy surface of particles. High temperature reaction produces aragonite particles with longer sizes and higher bulk densities. This study has made an attempt to establish the synthesis of aragonite with high brightness and high strength by utilization of waste scallop shells.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.9
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• pp.5419-5424
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• 2014

A weld scallop is a small quadrant or half circle type hole installed in the weld line cross area for easy welding operation. Many types of T-bars with a scallop can be welded in a block assembly stage in shipbuilding. The difficulties arise from the fact that scallops are to be filled by build-up welding after welding of the cross line is complete. In this study, a non-scallop block joint welding method was developed using special type CBM (ceramic backing material). The wedge shaped CBM was devised to insert a CBM into just the V groove of weld line cross area without weld scallop. A saw-toothed shape was adopted for easy cutting of the unnecessary part in the CBM fitting process. The applicability of the developed method was verified through welding experiments based on the yard welding conditions.

• Journal of Korean Society of Steel Construction
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• v.12 no.5 s.48
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• pp.487-494
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• 2000

This paper intends to propose design information with the result or comparing the deformation capacity with different panel stiffness specimens and estimating the plastic deformation capacity, toughness and strength of welded joint connection according to the different scallop types. The test results of the beam to column unit structure are as follow: the non-scalloped and the low stiffness panel specimen have more desirable result values than the scalloped and the high stiffness one in plastic deformation. Comparing the scallop types shows very unlikely tendency as follows, second cracking occurs at the very edge of scallop in the scalloped specimen otherwise cracking occurs bond area of welded beam flange in the non-scalloped one.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.1
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• pp.35-48
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• 1995

To develop the optimal design method for the longline type scallop culturing facilities in the open sea numerical calculations and hydraulic model experiments are carried out for the stability and function optimization. Using the results for the motion and tension of the facilities, stable design concepts and effects of motion control system by vertical anchor and resistance discs art discussed. The results of this study that can be applied to the design are as follows: 1) Total external forces by design wave $(H_{1/3}\;=\;6,7\;m,\;T_{1/3}\;=\;12sec)$ at the coastal waters of Jumunjin for unit facility (one main line) are estimated to 5-20 tons, and required anchor weights are 10-40 tons in the case of 2-point mooring system. Though the present facilities are stable to steady currents, but is unstable to the extreme wave condition of return period of 10 years. 2) The dimensions and depth of array systems must be designed considering the ecological environments as well as the physical characteristics including the mooring and holding forces that are proportional to the length and relative depth of main line to wave length, and the number of buoys and nets. 3) Oscillation of the facility is influenced by water particle motion and the weight of hanging net, and is excited at both edge, especially at the lee side. To reduce the motion of the nets, the vertical anchoring system and the resistence disc method are recommended by the experimental results, 4) The damage of rope near the anchor by abrasion should be prevented using the ring-type connection parts or anchor chains.

• Journal of Aquaculture
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• v.6 no.1
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• pp.1-12
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• 1993

Identification of blood cells and their physological functions in the cultured scallop, Patinopecten yessoensis collected from Abashiri Bay, Hokkaido, Japan were studied by electron microscopic structure and histological observations. The physiological function of each blood cell type was studied on the basis of its cytological structure, the lysosome in the blood cell and its phagocytosis. The blood cells were classified as Type I, Type II and Type III. The morphological characteristics of each blood cell type are as follows ; Type I : The cell is oval shaped and its cytoplasm contains comparatively low electron dense materials. The oval nucleus is sometimes ramified into two nuclei. Lumps of tubular smooth endoplasmic reticula and vacuoles are distributed near the nucleus. Type II : The cell appears long and oval shaped, and its cytoplasm contains high electron dense materials. The oval nucleus does not ramify, and large numbers of sac-like smooth endoplasmic reticula and free ribosomes are developed around the nucleus. No vacuoles exist in the cytoplasm Type 1II : The cell is round in shape and the electron density of the cytoplasm is the highest among the three types of cells because of large quantities of rough­surfaced endoplasmic reticula and no vacuoles. Particularly, the nucleus reveals a wheel-like shape owing to lumps of tuberous chromatin. The cells of Type I and II seem to have the role of carrying out phagocytosis on either foreign materials such as bacteria or endogenous old cells and the transport of nutritive materials. The type III cell, which has not been found in any bivalve species of non Pectinidae, may be said to have the function of production and the secretion of protein related to some humoral defense materials.

• Journal of Korean Society of Steel Construction
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• v.23 no.3
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• pp.295-304
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• 2011

Bracket-type connection is often used for the weak-axis steel connection. In general, a beam-to-column connection for the bracket type is fabricated at the shop and abeam splice is additionally attached to the bracket in the site. Therefore, steel construction would not be competitive due to the increase of beam splice fabrication cost and overall construction period. This paper now proposes the new weak-axis connection types without a scallop, which has more definite strength flow, simple connection details, and better workability. From the series of experiments, the proposed connections showed better strength and ductility in comparison with standard details with scallop because the thickness of the welding plate for wide-flanged, beam-to-column connection can be easily adjusted.

• Journal of the Microelectronics and Packaging Society
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• v.6 no.3
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• pp.9-18
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• 1999

In this study, Metallugical properties between Sn-3.5Ag, Sn-37Pb eutectic solders and Au/Ni/cu substrate according to time span above the melting point were investigated. A conventional reflow soldering machine wert used for this study and time span above the melting point was determined by changing peak soldering temperature and conveyor speed. As results, scallop type intermetallic compounds of $Ni_3Sn_4$ were formed at joint interface and no Cu-Sn compounds were found at all; Ni layer performed as a barrier for Cu diffusion. As the peak soldering temperature increased, thickness of the intermetallic compound layer increased; maximum thickness of the scallop-layer was 2.2$\mu\textrm{m}$. The shape of scallops were transformed from hemi-sphere type to elliptical shape with smaller size. Micro-hardness of the solder joint decreased as the eutectic structure of Sn-3.5Ag and Sn-37Pb increased.

• Journal of Korean Society of Steel Construction
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• v.18 no.1
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• pp.23-32
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• 2006

This study was conducted to improve the design and construction technique of orthotropic steel-deck bridges. After conducting an F.E.M. analysis of the various rib types of the connection details, static and fatigue tests were conducted, using a three-dimensional, full-scaled, orthotropic, steel-deck-plate model with internal diaphrams, to check the fatigue strength depending on the types of details. The model structure was made of two types of longitudinal ribs: the domestic standard and the European rabbit types. The fatigue strength of the steel-deck system was found to have improved through the installation of an internal diaphram, as no cracks were found on the bottom round part of the scallop with a diaphram. There were no differences between the domestic and the European types of details in terms of strength may be partially influenced by the shape of the scallop and by the installation of an internal diaphram, but it can be improved more significantly according to the quality of the welding that will be done.