Thermodynamic Modeling of Vapor-Liquid Equilibria and Excess Properties of the Binary Systems Containing Diethers and n-Alkanes by Cubic Equation of State

Bojan D. Djordjevi?,Slobodan P. ?erbanovi?,Ivona R. Grguri?,Mirjana Lj. Kijev?anin,Aleksandar ?. Tasi? 한국화학공학회 2004 Korean Journal of Chemical Engineering Vol.21 No.4

A comparison of the performances of two diferent approaches of cubic equations of state models, basedon a classical van der Wals and mixing rules incorporating the GEequation, was carried out for corelation ofVapor-Liquid Equilibria (VLE), HEand cPE data alone, and simultaneous correlation of VLE+HE, VLE+cPE, HE+cPE andVLE+HE+cPE data for the diethers (1,4-dioxane or 1,3-dioxolane) with n-alkane systems. For all calculations thePeng-Robinson-Stryjek-Vera cubic equation of state (PRSV CEOS) was used. A family of mixing rules for thePRSV CEOS based on the Modified van der Wals one-fluid mixing rule (MvdW1) and two well-known CEOS/GEmixing rules (MHV1 and MHV2), was considered. The NRTL equation, as the GEmodel with linear or reciprocal tem-perature dependent parameters, was incorporated in the CEOS/GEmodels. The results obtained by the CEOS/GEmodelsexhibit significant improvement in comparison to the MvdW1 models.

ON “VERY PALINDROMIC” SEQUENCES

Bojan Basic 대한수학회 2015 대한수학회지 Vol.52 No.4

We consider the problem of characterizing the palindromic sequences <cd−1, cd−2, . . . , c0>, cd−1 6 ≠ 0, having the property that for any K ∈ N there exists a number that is a palindrome simultaneously in K different bases, with <cd−1, cd−2, . . . , c0> being its digit sequence in one of those bases. Since each number is trivially a palindrome in all bases greater than itself, we impose the restriction that only palindromes with at least two digits are taken into account. We further consider a related problem, where we count only palindromes with a fixed number of digits (that is, d). The first problem turns out not to be very hard; we show that all the palindromic sequences have the required property, even with the additional point that we can actually restrict the counted palindromes to have at least d digits. The second one is quite tougher; we show that all the palindromic sequences of length d = 3 have the required property (and the same holds for d = 2, based on some earlier results), while for larger values of d we present some arguments showing that this tendency is quite likely to change.

Degradation of buckling capacity of slender concrete-filled double skin steel tubular columns due to interface compliance

Bojan Čas,Simon Schnabl 국제구조공학회 2022 Structural Engineering and Mechanics, An Int'l Jou Vol.82 No.5

In this paper a novel mathematical model and its analytical solution of global buckling behaviour of slender elastic concrete-filled double-skin tubular (CFDST) columns with finite compliance between the steel tubes and a sandwiched concrete core is derived for the first time. The model is capable of investigating the influence of various basic parameters on critical buckling loads of CFDST columns. It is shown that the elastic buckling load of circular and slender CFDST columns is independent on longitudinal contact stiffness, but, on the other hand, it can be considerably dependent on circumferential contact stiffness. The increasing of the circumferential contact stiffness increases the critical buckling load. Furthermore, it is shown that analytical results can agree well with the experimental and numerical results if the calibrated values of circumferential contact stiffness are used in the calculations. Moreover, it is shown that the contact between the steel tubes and a sandwiched concrete core of tested large-scale CFDST columns used in the comparison is relatively weak. Finally, the proposed analytical results can be used as a benchmark solution.

Grid-Enabled Parallel Simulation Based on Parallel Equation Formulation

Bojan Andjelkovic,Vančo B. Litovski,Volker Zerbe 한국전자통신연구원 2010 ETRI Journal Vol.32 No.4

Parallel simulation is an efficient way to cope with long runtimes and high computational requirements in simulations of modern complex integrated electronic circuits and systems. This paper presents an algorithm for parallel simulation based on parallelization in equation formulation and simultaneous calculation of matrix contributions for nonlinear analog elements. In addition, the paper describes the development of a grid interface for a parallel simulator that enables a designer to perform simulations on distant computer clusters. Performances of the developed parallel simulation algorithm are evaluated by simulation of a microelectromechanical system.

The Immersive Lab

Bojan Milosevic(보얀 밀로세비치),Jan Schacher(얀 샤체르) 한국전자음악협회 2015 에밀레 Vol.13 No.-

몰입형 랩은 취리히 예술대학Zurich University of the Arts 컴퓨터 음악 음향 기술 연구소Institute of Computer Music and Sound Technology의 예술 공학 연구 프로젝트이다. 참여 예술가들은 풀터치 상호작용이 있는 파노라마식의 비디오와 서라운드 음향이 통합된 미디어 공간을 위한 작품을 만든다. 그들의 주요 도전과제는 터치를 통해 시청각적으로 의미있는 상호작용이 가능한 모델을 찾는 것이다. 이 과정의 결과로서 상호작용 시청각 작품들이 대중에게 선보여진다. 이 글은 [몰입형 랩] 설치의 기술적 구성과 이 프로젝트에 내재한 개념을 설명하고, 주제와 관련하여 개념적일 뿐 아니라 기술적인 관점에서 미적 아이디어의 다양성을 역설한다. 예시된 참여 예술가의 작품들이 논의되면서, 어떠한 방식으로 몰입형 랩 설치의 초점이 관찰과 물리적 반응, 개인과 그룹의 상호작용을 중심으로 맞추어지는지를 보여준다. 한 미디어 환경에서 여러 방식의 상호작용 시청각 통합 형태를 이루어내었듯, 이 프로젝트가 실제적이고 자발적인, 협동적인 학습과 경험의 효과가 확실히 있었음을 다양한 아이디어[의 존재]와 상당수의 완성된 예술 작품으로 보여준다. The Immersive Lab is an artistic and technological research project of the Institute of Computer Music and Sound Technology at the Zurich University of the Arts. Participating artists create works for a media space, which integrates panoramic video, surround audio with full touch interaction. The main challenge for the artists is to find ways of translating touch into interaction models for their audio visual ideas. At the end of the process, works are presented to the public in the form of interactive audio visual compositions. This article exposes the technical structure of the installation, describes the underlying concepts of the project, and addresses the diversity of artistic ideas in the thematic, conceptual as well technical domains. Example works by participating artists are discussed and show in what way the central topics of the Immersive Lab installation revolve around observation, physical reaction, individual and group interaction. The diversity of ideas and the considerable number of completed artistic works confirm that the advantages of this project, i.e., the integration of interactive audio visual modes in one media environment, indeed inspire practical, spontaneous, and collaborative learning and experience.

Low-Temperature Deposition of Silicon-Nitride Layers by Using PECVD for High Efficiency Si Solar Cells

Bojan Karunagaran,E.-K Suh,J. P Jeong,S. J. Chung,Subramaniyam Nagarajan 한국물리학회 2006 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.48 No.6

Silicon nitride (SiNx) films were deposited onto acid-polished and phosphorous-doped multicrystalline silicon (mc-Si) wafers by using a horizontal plasma-enhanced chemical vapour deposition (PECVD) reactor at a relatively low temperature of 300 C. High-purity silane (SiH4) and ammonia (NH3) were employed in the present work as precursor gases and by varying the ratio of the precursor gases; we were able to modify the index of refraction of the resulting SiNx films from 1.9 to 2.3, which had a direct influence on the reflectance, which is a very important factor in deciding the solar cell efficiency. In order to show the effectiveness of our low-temperature deposited SiNx layers as AR coating layers, we fabricated mc-Si solar cells by using our PECVD SiNx layers, highthroughput screen printing, and rapid thermal processing (RTP) firing. Using this sequence, we were able to obtain solar cells with efficiencies over 14 % for polished mc-Si wafers of sizes 125 mm square.

Managing maritime automobile terminals: an approach toward decision-support model for higher productivity

Bojan Beškovnik,Elen Twrdy 대한조선학회 2011 International Journal of Naval Architecture and Oc Vol.3 No.4

The article describes actions and strategies to obtain higher productivity on maritime automobile terminals. The main focus is on elaboration of efficient and effective organizational structure to model and implement short-term, mid-term and long-term strategies. In addition, with an empiric approach we combined the analyses of current findings in important scientific papers and our acknowledgments in practical research of north Adriatic maritime automobile terminals. The main goal is to propose actions towards increasing system’s productivity. Based on our research of the north Adriatic maritime automobile terminals and with Lambert’s model an in-deep analysis of limiting factors, user’s expectations and possibilities for productivity increase has been performed. Moreover, with our acknowledgments a three-level decision-support model is presented. With an adequate model implementation it is possible to efficiently develop and implement different strategies of productivity measurement and productivity increase, especially in the fields of internal transport productivity, entrance/exit truck gates operations and wagon manipulations. According to our observation a significant increase might be achieved in all three fields.

America’s Nationalist Turn and Territorial Revisionism in the Asia-Pacific

Bojan PETROVIC 동북아역사재단 2017 Journal of Northeast Asian History Vol.14 No.2

An Investigation of Formulation Factors Affecting Feasibility of Alginate-Chitosan Microparticles for Oral Delivery of Naproxen

Bojan Calija,Nebojsa Cekic,Snezana Savic,Danina Krajisnik,Rolf Daniels,Jela Milic 대한약학회 2011 Archives of Pharmacal Research Vol.34 No.6

In the present work we investigated the feasibility of chitosan treated Ca-alginate microparticles for delivery of naproxen in lower parts of GIT and evaluated influence of formulation factors on their physicochemical characteristics and drug release profiles. Investigated factors were drug/polymer ratio, chitosan molecular weight, chitosan concentration in hardening medium, and hardening time. Sixteen microparticle formulations were prepared utilizing 24 full factorial design (each factor was varied at two levels). Microparticles size varied between 262.3 ± 14.9 and 358.4 ± 21.7 μm with slightly deformed spherical shape. Low naproxen solubility and rapid reaction of ionotropic gelation resulted in high encapsulation efficiency (> 75.19%). Under conditions mimicking those in the stomach, after two hours, less than 6.18% of naproxen was released. Significant influence of all investigated factors on drug release rate was observed in simulated small intestinal fluid. Furthermore, experimental design analysis revealed that chitosan molecular weight and its concentration had the most pronounced effect on naproxen release. Release data kinetics indicated predominant influence of a pH-dependent relaxation mechanism on drug release from microparticles.

Confocal imaging of biomarkers at a single-cell resolution: quantifying 'living' in 3D-printable engineered living material based on Pluronic F-127 and yeast Saccharomyces cerevisiae

Žunar Bojan,Ito Taiga,Mosrin Christine,Sugahara Yoshiyuki,Bénédetti Hélène,Guégan Régis,Vallée Béatrice 한국생체재료학회 2023 생체재료학회지 Vol.27 No.00

Engineered living materials (ELMs) combine living cells with non-living scaffolds to obtain life-like characteristics, such as biosensing, growth, and self-repair. Some ELMs can be 3D-printed and are called bioinks, and their scaffolds are mostly hydrogel-based. One such scaffold is polymer Pluronic F127, a liquid at 4 °C but a biocompatible hydrogel at room temperature. In such thermally-reversible hydrogel, the microorganism-hydrogel interactions remain uncharacterized, making truly durable 3D-bioprinted ELMs elusive.We demonstrate the methodology to assess cell-scaffold interactions by characterizing intact alive yeast cells in cross-linked F127-based hydrogels, using genetically encoded ratiometric biosensors to measure intracellular ATP and cytosolic pH at a single-cell level through confocal imaging.When embedded in hydrogel, cells were ATP-rich, in exponential or stationary phase, and assembled into microcolonies, which sometimes merged into larger superstructures. The hydrogels supported (micro)aerobic conditions and induced a nutrient gradient that limited microcolony size. External compounds could diffuse at least 2.7 mm into the hydrogels, although for optimal yeast growth bioprinted structures should be thinner than 0.6 mm. Moreover, the hydrogels could carry whole-cell copper biosensors, shielding them from contaminations and providing them with nutrients.F127-based hydrogels are promising scaffolds for 3D-bioprinted ELMs, supporting a heterogeneous cell population primarily shaped by nutrient availability.