• Clinical and Experimental Reproductive Medicine
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• v.8 no.2
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• pp.29-33
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• 1981

Vesectomy has been increased as a popular method of birth control because it is simpler than other methods for men. But the vasectomy results in several problems such as relation to effect changes on the structure and function of the reproductive organ. The fate of non-ejaculated spermatozoa is postulated by some authors that those are disappeared by a progress of dissolution and reabsorption in the epididymis, and we have attempted to prove the true state of sperm-acrosome on the fine structure in vasectomized rats. The results were as follows: 1. Apical segments of the acrosome were swollen similar to the shape of club in many spermatozoa. 2. Discontinuities of the outer and inner acrosomal membranes were occasionally noted and there were complete losses of acrosomes in the certain place. 3. There was no evidence of significant changes in the nuclear structure, nor dilatation of the subacrosomal space. 4. Vasectomy might effect destructive changes in the acrosomes of the non-ejaculated spermatozoa in situ.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.1251-1256
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• 2008

Urban railway system has make rapid progress ever since Seoul metro line No.1 was opened in 1974. Now, it is time to prepare system maintenance scheme and procedure that can be available even after 30 years from now. Especially, signaling system must be chosen with considering its life cycle since the system is categorized into electronic equipments. As for current signaling system, mechanical components such as relays has decreased while communication and S/W has integrated in order to implement its correct function. Therefore, it is required to establish system review and switch-over scheme with considering operational environment, maintenance system and an operator. In this paper, therefore, we analyzed various factors - technical, operational and economic - that have effect on system improvement so as to prevent making any mistakes on system improvement.

• Progress in Superconductivity and Cryogenics
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• v.23 no.4
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• pp.49-55
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• 2021

The Cable in Conduit Conductor (CICC) configurations are designed, tested and realized to make high field superconducting (SC) magnets. The evolution of CICC design makes it challenging to forecast thermo-hydraulic behavior. A common objective of thermo-hydraulic studies is to obtain the most reliable predictive correlation for friction factor in CICC geometries and to reduce the dependency on the experiment. So far, only the void fraction and Reynolds number have been considered in the predictive correlations in an explicit way. In the present paper, the CICC twisting pattern dependency, called tortuosity (τ), on the pressure drop prediction, has been assessed through a numerical simulation approach. The CICC twisting pattern with 6+1 petals (solid conductor in the present study) with different twisting pitches is mimicked in the numerical simulation for the range 100 ≤ Re ≤10000 and 1 < τ < 1.08 and a correlation for friction factor, f, has been proposed as a function of Re and τ.

• Korean Journal of Breeding Science
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• v.42 no.4
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• pp.339-343
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• 2010

Post-translational covalent modifications by small molecules or peptides remodel target proteins. One such modification, made by ubiquitin or small ubiquitin-related modifier (SUMO), is a rapidly expanding field in cell signaling pathways. Ubiquitin attachment controls the turnover and degradation of target proteins while SUMO conjugation regulates their activity and function. Recent studies report many examples of cross-talk between ubiquitin and SUMO pathways, indicating that the boundary is no longer clear. Here, we review recent progress concerning how ubiquitin and SUMO participate in new regulatory roles in plant cell, and how ubiquitination and sumoylation control plant growth and development.

• Food Engineering Progress
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• v.13 no.1
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• pp.70-73
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• 2009

The yield stress of stirred yogurt was measured by the vane viscometer at different pre-shearing conditions, such as pre-shear speed, pre-shear time, and wait time, and temperature (12-38${^{\circ}C}$). The yield stress ranged from ~17.6 to 10 Pa and from 34.2 to 11.9 Pa, depending on the pre-shearing conditions and temperature, respectively. The preshear speed and the wait time significantly affected the yield stress. The temperature dependence of the yield stress was described by the Eyring's kinetic model. The linear function of the temperature on the yield stress was limited at the 22${^{\circ}C}$, and at the above 22${^{\circ}C}$, the yield stress was maintained to be a constant (~12.5 Pa).

• Journal of Integrative Natural Science
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• v.12 no.1
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• pp.1-8
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• 2019

Smart pole is one of mega trend in smart city development. It has multi-function to get as much as data from the street to better city management. And smart street lighting of smart pole as core part of smart city development is being implemented by many cities in globally. Refer to the latest edition of Navigant Research's Smart City Tracker includes smart city projects in 221 cities, a quarter of which are deploying smart street lighting ranging from initial pilots to citywide and regional deployments that span tens and even hundreds of thousands of lights. The most important feature of smart street lighting solution is "Connectivity" through the IoT technology. In order to implement the smart city, we should have so-called intelligent watchdog and mesh networked post for keeping the various smart city technology development progress and operation properly. Smart street lighting solution could be main infrastructure as an enabler for a range of smart city applications. We can talk about the expected role of smart street lighting for the smart city development on this paper.

• Applied Chemistry for Engineering
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• v.33 no.3
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• pp.242-257
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• 2022

Microalgae is becoming a vital component for a circular economy and ultimately for sustainable development. Herein, recent developments in different outcomes of microalgae for wastewater treatment and biorefinery were reviewed. From its primary function as a third-generation resource of biofuel, the usage of microalgae has been diversified as an integral element for the CO₂ sequestration and production of economically valuable products (e.g., pharmaceuticals, animal feeds, biofertilizer, biochar, etc.). Principles and recent challenges for each microalgae application were presented to suggest a motivation for future research and the direction of development. The integration of microalgae within the concept of the circular economy was also discussed with various routes of microalgae-based biorefinery.

• International Journal of Advanced Culture Technology
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• v.10 no.3
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• pp.192-201
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• 2022

The Han Dynasty was the great unification dynasty in history after the Qin Dynasty. Since the Han Dynasty inherited the Qin system, the seal script of the Han Dynasty developed continuously based on inheriting the Qin Small Seal Script. With the progress of social productivity, the Official Script gradually replaced the Seal Script in the Han Dynasty, but the Seal Script did not disappear completely; instead, a special line of development arose under the influence of the Official Script. Through the study of seal script of Han Dynasty inscriptions, this paper understands that the practical function of seal script of inscriptions has been weakening under the influence of clerical script, but the aesthetic value has been increasing day by day. Moreover, there were new artistic innovations in the context of the development of the diversification of inscriptional forms, and its emphasis on social role, cultural status, and the presentation of an aesthetic style that had a profound impact on later generations are worth studying.

• Progress in Superconductivity and Cryogenics
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• v.24 no.4
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• pp.11-15
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• 2022

We conducted numerical calculations to obtain the critical current as a function of the magnetic flux through the topologically trivial and non-trivial superconducting quantum interference devices (SQUIDs), with varying the capacitive and inductive couplings of Josephson junctions (JJs). Our calculation results indicate that a nontrivial SQUID is almost indistinguishable from trivial SQUID, considering the effective capacitance coupling. When the SQUID contains 2π- and 4π-periodic supercurrents, the periodicity of the current-flux relation can be distinguished from the purely trivial or nontrivial SQUID cases, and its difference is sensitive to the relative ratio between the topologically trivial and nontrivial supercurrents. We believe that our calculation results would provide a practical guide to quantitatively measure the portion of the topologically nontrivial supercurrents in experiments.

• Progress in Superconductivity and Cryogenics
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• v.10 no.3
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• pp.14-18
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• 2008

This paper deals with the conceptual design and characteristic analysis of core type superconducting motor using iron cores in the field. As the objective function of conceptual design, the flux quantity per pole is selected. In order to reduce the quantity of superconductors, the variations of flux quantity per pole by changing the design variables and area are investigated. Finally, the quantity of superconductors between air-cored and core type superconducting motor is compared under the same motor capacity. In addition, the dimensions and volumes of motors are compared.