Liquid Metal Embrittlement of Resistance Spot Welded 1180 TRIP Steel: Effect of Electrode Force on Cracking Behavior

Du‑Youl Choi,Ashutosh Sharma,Sang‑Ho Uhm,Jae Pil Jung 대한금속·재료학회 2019 METALS AND MATERIALS International Vol.25 No.1

Liquid metal embrittlement (LME) caused cracking of Galvanized transformation induced plasticity steels was investigatedduring resistance spot welding (RSW). Effect of electrode force (3–5 kN) for a weld time of 400, and 800 ms on crack resistanceof TRIP steel was examined in relation to LME phenomenon. The microstructural characteristics of spot weld jointsand LME cracking tendency were investigated using dye penetration tests, optical microscopy, scanning electron microscopytogether with energy dispersive X-ray spectroscopy. It was found that as the electrode force increases, the crack size decreasesdue to a fast increase in crack tip temperature which rises further with more holding time up to 800 ms in high temperaturezone. Least amount of crack size was observed at 5 kN electrode force and 400 ms of welding time. Finally, the experimentalresults have also been simulated by finite element modeling (FEM) to find suitable mechanism of crack formation, and acombination of 4 kN and 400 ms was suggested for the crack free and less thermal deformation in the spot welded TRIP steel.

A correlation for heat of vaporization of pure compounds

Dušan K. Grozdanic,Jovan D. Jovanovic 한국화학공학회 2008 Korean Journal of Chemical Engineering Vol.25 No.6

Twenty-seven selected equations were tested on 162 compounds with 1958 calorimetric data for their abilities to reflect the temperature influence on the heat of vaporization of pure compounds. A new equation is recommended (overall percent deviation 0.27% and percent deviation 0.59% above 0.9Tr).

Where Does Value-Added Flow in Gross Exports, Mr. Newton? Global Supply Chains and New Regionalization's Effects in the Asia-Pacific

Dušan Steinhauser 세종대학교 경제통합연구소 2023 Journal of Economic Integration Vol.38 No.3

Generic Competency Model: Business Graduate Key Competencies for Successful Working at Trading Companies - Case Study from the Czech Republic

Radim Duš,다 People&Global Business Association 2021 Global Business and Finance Review Vol.26 No.4

Purpose: The aim of this paper is to create a generic competency model based on the entry-level positions’ requirements of human resource managers in trading companies operating in the Czech Republic. The proposed model should define an optimal set of key competencies that a competent graduate of business degree should have to be successful in specific selection processes for different graduate jobs in trading companies and thus be successful in performing job duties. Design/methodology/approach: The research question for this study was which key competencies business graduates need the most for entry-level positions in the field of trading and which ideal behavior is expected for such competencies. Within the questionnaire survey, the degree of significance of the defined key competencies was subsequently determined. The target population consisted of trading companies with 25 - 249 employees based and operating in the Czech Republic that are willing to hire fresh graduates for entry-level positions. The quantitative data was finally obtained from 419 companies. On the basis of the data analysis results, a generic competency model of a university graduate of business degree was created. Findings: The generic model developed on the basis of the data from trading companies consists of two parts. It defines an optimal set of 6 key competencies as well as the expected behavior that a competent business graduate should have to succeed in specific selection processes for various positions in trading companies that require university education, and subsequently, to be successful in performing jobs in the trade sector. Research limitations/implications: The research limitations are caused mainly by two factors: the company size and products that the trading company is (re)selling. Although specific key competencies can be rated as very important by two different recruiters in the questionnaire, requirements, and expectations of a small company operating in an extremely competitive environment may be significantly higher than in the case of company with large staff and an extensive customer base, or vice versa. Originality/value: The resulting competency model can make the selection process more transparent for both recruiters and job candidates because of established standards concerning desirable key competencies for such positions in trading companies. At the same time, this tool can be an acceleration and suitable starting point for more extensive implementation of the modern competency-based approach for economics and business degrees at universities.

Spent fuel characterization analysis using various nuclear data libraries

Čalič Dušan,Kromar Marjan 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.9

Experience shows that the solution to waste management in any national programme is lengthy and burdened with uncertainties. There are several uncertainties that contribute to the costs associated with spent fuel management. In this work, we have analysed the impact of the current nuclear data on the isotopic composition of the spent fuel and consequently their influence on the main spent fuel observables such as decay heat, activity, neutron multiplication factor, and neutron and photon source terms. Nuclear libraries based on the most general nuclear data ENDF/B-VII.0, ENDF/B-VII.1, ENDF/B-VIII.0 and JEFF-3.3 are considered. A typical NPP Krsko fuel assembly is analysed using the Monte Carlo code Serpent 2. The analysis considers burnup of up to 60 GWd/tU and cooling times of up to 100 years. The comparison of results showed significant differences, which should be taken into account when selecting the library and evaluating the uncertainty in determining the characteristics of the spent fuel

Geomarketing - Tool for Consumer Spending Estimation in the Czech Tourism & Hospitality Market

Radim Dušek,Petr Štumpf,Viktor Vojtko 사람과세계경영학회 2019 Global Business and Finance Review Vol.24 No.1

This paper deals with a source market size estimation tool that is based on a combination of geomarketing information and consumer spending datasets. We have decided to apply a proposed estimation method on three consumption expenditure groups that are related to the tourism and hospitality industry in the Czech Republic. The geographic and consumer spending data sets for the period 2011 - 2016 were drawn from publicly available sources. With the use of GIS software, this method allowed us to estimate and graphically display consumer spending on recreation and culture; restaurants and hotels; and transport in 2016 at the level of Czech districts, as well as the average annual growth rate during the period 2011 – 2016. This paper describes the Czech tourism and hospitality market from its size and growth point of view. It shows the trends in expenditures for hospitality and tourism services, explain the purchasing power in Czech regions and districts and predict the development for next few years. The results obtained by this low-cost method can be easily used by enterprises from the Czech Republic within domestic tourism, as well as by the foreign companies wanting to attract Czech visitors.

Measurement of nuclear fuel assembly’s bow from visual inspection’s video record

Plašienka Dušan,Knotek Jaroslav,Kopeć Marcin,Malá Martina,Blažek Jan 한국원자력학회 2023 Nuclear Engineering and Technology Vol.55 No.4

The bow of the nuclear fuel assembly is a well-known phenomenon. One of the vital criteria during the history of nuclear fuel development has been fuel assembly’s mechanical stability. Once present, the fuel assembly bow can lead to safety issues like excessive water gap and power redistribution or even incomplete rod insertion (IRI). The extensive bow can result in assembly handling and loading problems. This is why the fuel assembly’s bow is one of the most often controlled geometrical factors during periodic fuel inspections for VVER when compared e.g. to on-site fuel rod gap measurements or other instrumental measurements performed on-site. Our proposed screening method uses existing video records for fuel inspection. We establish video frames normalization and aggregation for the purposes of bow measurement. The whole process is done by digital image processing algorithms which analyze rotations of video frames, extract angles whose source is the fuel set torsion, and reconstruct torsion schema. This approach provides results comparable to the commonly utilized method. We tested this new approach in real operation on 19 fuel assemblies with different campaign numbers and designs, where the average deviation from other methods was less than 2 % on average. Due to the fact, that the method has not yet been validated during full scale measurements of the fuel inspection, the preliminary results stand for that we recommend this method as a complementary part of standard bow measurement procedures to increase measurement robustness, lower time consumption and preserve or increase accuracy. After completed validation it is expected that the proposed method allows standalone fuel assembly bow measurements.

Noun-formation in the Contemporary Serbian Language

두샨카 부요비치(Dušanka Vujović ) 한국외국어대학교 동유럽발칸연구소 2023 동유럽발칸연구 Vol.47 No.2

이 논문은 현대 세르비아어에서 명사 형성의 형태소, 과정 및 패턴을 소개하며, 파생어와 합성어를 연구하기 위해 필요한 가장 기본적인 개념을 제시한다. 단어 기본형과 접사(접미사와 접두사)는 조어의 기본 구조 요소로 제시된다. 분석은 접미사, 접두사, 합성어, 약어, 변환 등의 명사 형성 과정을 포함한다. 접사 요소의 분석은 새로운 단어의 형식적 구조 관점에서 이루어지며, 기본 단어의 의미를 수정하는 데 사용되는 의미를 제외한 접사 목록이 주로 포함되어 있다. 접사요소의 분석은 조어의 형식구조 관점에서 수행되었으며, 기본어의 의미를 수식하는 의미 외에 접사의 목록을 중심으로 이루어졌다. 접미사화 부문에서는 접미사를 추가하는 기본어와 함께 형성되는 일반적인 의미 유형에 따라 명사를 열거한다. 이는 인간, 동물 및 식물, 물체, 장소, 동사 파생 명사, 추상적 명사, 약칭 및 위선적인 의미의 명사, 증강 및 비하적 의미의 명사 등을 나타낸다. 접두사화 부분에는 명사 형성에서 가장 자주 사용되는 접두사가 사용 예와 함께 나열되어 있다. 이 부분에서는 단어 기본형에 접두사와 접미사를 동시에 추가하는 방법도 설명하고 있다. 명사의 파생에서 접두사와 접미사가 동시에 추가되는 경우가 많기 때문에 명사의 접두사-접미사 동시 형성의 특징적인 예도 제시된다. 합성에 대한 부분에는 품사에 따라 가장 일반적인 합성어 유형들이 열거되어 있다. 약어와 활용 부분에는 주요 그룹과 전형적인 사용 예시가 제시되어 있다. 이 논문은 더 복잡한 데이터 연구에 필요한 파생어와 합성어의 연구에 필수적인 가장 기본적인 개념을 제시하며, 단어 형성의 개념을 더 깊이 이해를 가능하게 한다. The Serbian language is a highly inflected language with a complex morphological system that uses an extensive number of word affixes to express a wide range of grammatical, syntactic, and semantic characteristics. The present paper introduces contemporary Serbian noun-forming elements, processes, and patterns. Understanding the process of word formation makes it easier to learn Serbian as a foreign language, especially for speakers of agglutinative languages such as Korean.

Self - protective Activity of Colostral IgA Globulin from Tryptic Digestion

Kim, Woo Jung,Kang, Yoon Se,Shim, Bong Sop,Cho, Sung Hoon,Lee, Du Bong 생화학분자생물학회 1971 BMB Reports Vol.2 No.2

Although the amount of IgA in serum is small compared with the amount of IgG, IgA is redominant in secretory fluids such as colostrum, saliva, nasal fluid and tears. IgA from the colostrum and saliva has a higher sedimentation constant (11S) than serum IgA(7S), and 11S colostral IgA has additional antigenic determinants with specificities which are not present in serum IgA. In addition to the heavy and light chains present in the molecule of serum IgA, colostral IgA has another protein component-the transport piece or the secretory piece. Immune globulin in colostrum accounts for the immunity to certain infections acquired by newborn mammals after suckling. After hydrolysis in the gut, proteins in the form of aminoacids are thought to be absorbed, but there is -no experimental evidence for this. We have therefore studied the problems as follows. Colostrum was collected after delivery from primiparous women, and colostraI IgA was purified by gel filtration with Sephadex G-200 and DEAE-cellulose chromatography according to the method of Cebra and Robins. Antitryptic activity was measured in two ways. First, the inhibitory capacity of whole colostrum against trypsin was performed as described by Faarvang using urea-denatured bovine hemoglobin solution as substarate. Fifty microliters of a 0.2 per cent solution of crude trypsin was warmed at 25 for 20 minutes in a water bath. One hundred and fifty microliters of fresh whole colpstrum, prewarmed to 25 or 150 microliters of human serum was added to the above prewarmed enzyme solution. Two minutes later 0.5 ㎖ of 22 per cent urea-denatured bovine hemoglobin solution and 100 microliters of 0.1 M phosphate buffer, pH 8.0, were added, and the mixture was incubated for 20 minutxs at 25° The undigested protein was then precipitated by 2.5 ㎖ of 0. 3 M trichloroacetic acid. After the mixture had been centrifuged or filtered, 50 microliters of the supernatant was used for the Folin-Ciocalteu reaction. Trichloroacetic acid was added to the blank before addition of the hemoglobin solution, and the absorbance was read at 700 mmicrons with a Beckman DU-2 spectrophotometer. The second method which we followed was as described by Kueppers and Bearn. One part pf 0. 1 per cent bovine fibrinogen in 0.1 M phosphate buffer, pH 8.0, ,was mixed with ten parts of 2 per cent hot agar (80-90°in 0.1 M phosphate buffer, pH 8. 0. On mixing the fibrinogen with hot agar the mixture immediately turned cloudy and it was poured onto a glass slide which was kept in a moist chamber for one hour. A longitudinal strip of agar, 3 mm wide, was then cut out to make a trough, and near the trough two wells, 0.4 mm ;in diameter, were punched out of the agar. The trough was filled with 0.2 per cent crLde trypsin solution in 0.1 M phosphate buffer, pH 8. 0. One hundred microliters of fresh human colostrum or isolated colostral IgA or fresh human serum were introduced side by side into the wells and the slide was left overnight at 40 in a moist chamber. After washing the slide with 0.15 M NaCl to remove the digested fibrinogen peptides, it was stained with amidoblack 10B. Using hemoglobin as substrate, colostrum-unlike serum-did not show antitryptic activity. When, however, either colostrum or colostral IgA was tested using the fibrinogen-agar-gel slide technic, it showed antitryptic activity similar to that shown by serum. The discrepancy between the two results can be explained as follows. Serum antitrypsin acts. directly on the trypsin molecule, thus protecting every kind of protein molecule from tryptic digestion. Colostral IgA on the other hand has only self-protecting activity against trypsin. Thus when hemoglobin was used as substrate there was no antitrypticactivity, whereas in the fibrinogen-agar-gel slide technic antitryptic activity was evident because colostral IgA which cannot be digested by trypsin diffused through the fibrinogen-agar medium. From the theoretical point of view also, colostral antibody should not interfere with the digestion of other nutritionally important proteins in the milk and. it should have only self-protective action for absorption or for its biologic activity in the gut. The presence of antitrypsin in colostrum was thought to aid passive alimentary immunity by delaying they hydrolysis of antibody. Chamberlain and others, however, failed to show the absorption of gamma globulin intact in piglets after experimental addition of antitxypsin. It may be then that passive immunity is aided only by the antitryptic activity of specific, intrinsic colostral IgA. At the present time we do not know whether the whole intact IgA molecule or only that part which retains the antibody activity is protected from tryptic digestion. Serum IgA and. colostral IgA differ in the presence of the so-called transport piece in the calostral IgA molecule. We have demonstrated the presence of the additional protein component in the colostral IgA. by gel filtration of reduced and alkylated colostral IgA, so it seems reasonable to assume that one possible function of the transport piece is to protect the molecule or the part of the molecule which has the antibody activity from proteolytic enzymes in the gut. Direct demonstration of the antitryptic activity of the transport piece is now under progress.

Processing and Characterisation of Hybrid Aramid Fabrics Reinforced with Cross-linked Electrospun PVB Composite Nanofibres

Vera Obradović,Dušica B. Stojanović,Ivona Janković Častvan,Vesna Radojević,Petar S. Uskoković 한국섬유공학회 2018 Fibers and polymers Vol.19 No.9

The aim of this study was to fabricate a new kind of hybrid fabric composites with the cross-linked electrospun poly(vinyl butyral) (PVB) composite nanofibres. The experiments were performed with the 10 wt.% PVB/ethanol solution for electrospinning where the modified silica nanoparticles (mSiO2), the oxidised single-walled carbon nanotubes (o- SWCNT) and the o-SWCNT/mSiO2 hybrid nanoparticles were added to the solution. The electrospun fibres were crosslinked with glutaraldehyde (GA) afterwards in order to reinforce the composite structure by bonding to the p-aramid fabrics. The chemical and thermo-mechanical properties of the hybrid fabric composites were evaluated. The greatest improvement in thermo-mechanical properties was achieved by the sample which contained the cross-linked PVB fibres with the o- SWCNT/mSiO2 hybrid nanoparticles.