http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Determination the efficiency of open mixing screws
Attila Varga,Istvan Keppler,Laszlo Fenyvesi 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.6
Our goal is the determination of the material flow processes around the mixing screws and introducing a new mixing index which can characterize the performance of open mixing screws. The validation of the new discrete element model is demonstrated by experimental results of our self-developed apparatus. To quantify the mixing efficiency of open mixing screws we use the value of mixed volume around the screws. Sensitivity analysis is used to analyze how the different values of leaf diameter, pitch and angular velocity affect the mixed volume.
Seifeddine Garneoui,Péter Korzenszky,István Keppler 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.3
Numerous powder manufacturing industries such as food and pharmaceutical require the use of mixers to ensure that loaded materials meet a certain level of uniformity to procure an end-product of a high standard. Studies concerning mixing issues still do not fully cover the choice of the optimal mixer parameters. In this paper, we investigated the effects of filling configuration and the number of paddles on the mixing rate in a single-shaft paddle mixer. We used bi-colored corn grains as solid particles and employed discrete element simulations using LIGGGHTS-PUBLIC®. To calculate the static friction, rolling friction, and the coefficient of restitution, we applied the box discharging technique. The coordinates-based mixing rate socalled nearest-neighbor index was employed to quantitatively examine the different mixing rates along the mixing period according to two variables, namely, filling type and paddle number. Filling one type of particles then filling the other type on top of it in the mixer achieves better mixing efficiency compared with sidewise filling of particles. The use of a high number of paddles improves the mixture uniformity, while using more than five paddles has no further impact on the mixture. Also, mixing is more efficient when dealing with particles that have the same or different number of clumps, whereas mixing spherical grains with five-sphere clump grains decreases the mixing efficiency considerably.
Optimal oscillation parameters of vibrating screens
Ferenc Safranyik,Bela M. Csizmadia,Attila Hegedus,Istvan Keppler 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.5
Optimal oscillation parameters of vibrating screens are determined using analytical methods by investigating movement of a single spherical grain particle in the vibrating sieve’s non-inertial reference frame. Dimensionless parameters determining the efficiency of screening process are defined. Effect of interactions between multiple numbers of particles moving on the screen is analyzed using discrete element method. By comparing the analytical and numerical results, it can be seen, that the analytical evaluation of screening efficiency can be used until a given contaminant size unlimitedly in the examined range of screen angle. Additionally in case of this minimal contaminant size there is a maximal screening angle value. Above this angle it seems, that the use of our discrete element based evaluation of screening efficiency is unavoidable.
The wide utility of rabbits as models of human diseases
Pedro J. Esteves,Joana Abrantes,Hanna-Mari Baldauf,Lbachir BenMohamed,Yuxing Chen,Neil Christensen,Javier González-Gallego,Lorenzo Giacani,Jiafen Hu,Gilla Kaplan,Oliver T. Keppler,Katherine L. Knight 생화학분자생물학회 2018 Experimental and molecular medicine Vol.50 No.-
Studies using the European rabbit Oryctolagus cuniculus contributed to elucidating numerous fundamental aspects of antibody structure and diversification mechanisms and continue to be valuable for the development and testing of therapeutic humanized polyclonal and monoclonal antibodies. Additionally, during the last two decades, the use of the European rabbit as an animal model has been increasingly extended to many human diseases. This review documents the continuing wide utility of the rabbit as a reliable disease model for development of therapeutics and vaccines and studies of the cellular and molecular mechanisms underlying many human diseases. Examples include syphilis, tuberculosis, HIV-AIDS, acute hepatic failure and diseases caused by noroviruses, ocular herpes, and papillomaviruses. The use of rabbits for vaccine development studies, which began with Louis Pasteur’s rabies vaccine in 1881, continues today with targets that include the potentially blinding HSV-1 virus infection and HIV-AIDS. Additionally, two highly fatal viral diseases, rabbit hemorrhagic disease and myxomatosis, affect the European rabbit and provide unique models to understand co-evolution between a vertebrate host and viral pathogens.