다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

Fundamentals of Modern Manufacturing: Materials, Processes and Systems

An overview of graphene and its derivatives reinforced metal matrix composites: Preparation, properties and applications

Anatomic differences on the toe pad epithelial cells of torrent and tree frogs (elongated versus regular geometry) are believed to account for superior ability of torrent frogs to attach to surfaces in the presence of running water. Here, the friction properties of artificial hexagonal arrays of polydimethylsiloxane (PDMS) pillars (elongated and regular) in the presence of water are compared. Elongated pillar patterns show significantly higher friction in a direction perpendicular to the long axis. A low bending stiffness of the pillars and a high edge density of the pattern in the sliding direction are the key design criteria for the enhanced friction. The elongated patterns also favor orientation-dependent friction. These findings have important implications for the development of new reversible adhesives for wet conditions.

Frontispiece. Wet Adhesion: Torrent Frog-Inspired Adhesives. Attachment to Flooded Surfaces

Primjena aluminijskih hibridnih kompozita u automobilskoj industriji

This paper explains development of the general mathematical model of trochoidal gearing that can be applied for gerotor pumps and cyclo reducers. The model analyzes geometry and physics of the gearing pair in trochoidal pump where the outer gear has one tooth more than the inner gear. The inner gear profile is described by peritrochoid equidistance and the outer gear profile by circular arc. Mathematical model of gearing with clearances is based on the principle of an ideal profile development. Minimum clearance height between teeth profiles in relation to instantaneous gear ratio is determined. The influence of gear profile geometrical parameters on gearing process, clearance height change, and pulsation of drive moment is analyzed and presented in numerical examples. Obtained results can be used for the design of the trochoidal gearing where accurate and silent operation is required. [DOI: 10.1115/1.4005621]

Modeling of the Meshing of Trochoidal Profiles With Clearances

This article presents the analyses of the forces and moments between gears in contact with a gerotor pump. The objective was to reach a more accurate solution for the problems related to load distr...

Analysis of Forces and Moments in Gerotor Pumps

This paper presents research of the impact toughness and hardness distribution in specific zones of a ‘single V’butt multiple-pass welded joints of the high-strength low-alloyed steels. Obtained values of the impact toughness are analyzed in correlation with a microstructure in specific zones of the welded joint, together with the micro hardness distribution found in the related zones. Based on the carried out analysis and results obtained in experiments, the applied technology of welding was evaluated. The original conclusions on influence of the selected welding procedure manual metal arc (MMA) for the root passes and metal active gas (MAG) for the filling and covering passes) on impact toughness of the high-strength low-alloyed steels are drawn. The paper also presents discussion on the valid standards and recommendations related to welding of those steels, from the aspect of applications in design of steel welded constructions.

Analysis of Selected Properties of Welded Joints of the HSLA Steels.

cycloidal speed reducers belong to the new generation of mechanical gears. cy cloidal speed reducers are increasingly used in modern engineering due to their good performances. Friction exists at all points of contact between the moving elements of cycloidal speed reducers, as one of the main causes of power losses in power transmission. In this paper, the friction of the contact of cycloid disc and housing rollers has been taken into account, while the friction at the contact of cycloid disc and output rollers, and at the contact of cycloid disc and central roller bearings are neglected. The effect of friction on the distribution of contact force, the friction torque value is analysed as well as efficiency. This paper pres ents 2 analytical models for calculating the values of contact force and friction torque. The 2nd model opposed to the 1st, taking into account the phenomenon of friction. The results showed that friction significantly affects the distribution of normal force. Increase of the friction produces the contact forces and friction torque increase, also, while efficiency is decreasing.

Lozica Ivanović

Papers

Primjena aluminijskih hibridnih kompozita u automobilskoj industriji

Modeling of the Meshing of Trochoidal Profiles With Clearances

Analysis of Forces and Moments in Gerotor Pumps

Analysis of Selected Properties of Welded Joints of the HSLA Steels.

Influence of the friction on the cycloidal speed reducer efficiency