Increasing flexibility of self-piercing riveting by reducing tool–geometry combinations using cluster analysis in the application of multi-material design

A frequently used mechanical joining process that enables the joining of dissimilar materials is self-piercing riveting. Nevertheless, the increasing number of materials as well as material–thickness combinations leads to the need for a large number of rivet–die combinations as the rigid tool systems are not able to react to changing boundary conditions. Therefore, tool changes or system conversions are needed, resulting in longer process times and inflexibility of the joining processes. In this investigation, the flexibility of the self-piercing riveting process by reducing the required tool–geometry combinations is examined. For this purpose, various joints consisting of similar as well as dissimilar materials with different material thickness are sampled and analysed. Subsequently, a cluster algorithm is used to reduce the number of rivet–die combinations required. Finally, the effect of the changed tool geometries on both the joint formation and the joint load-bearing capacity is investigated. The investigation showed that a reduction by 55% of the required rivet–die combinations was possible. In particular, the rivet length influences the joint formation and the joint load-bearing capacity. An exclusive change of the die (e.g. die depth or die diameter) did not show a significant influence on these parameters.

PENELITIAN TENTANG FORMATIO SPIRITUALITAS DAN KEPRIBADIAN DI RUMAH BINA KARYA ILLAHI MADIUN

Rumah Bina Karya Illahi is a house (a kind of dormitory) that accommodates first-level. Rumah Bina organizes a lot of coaching as a basis for students to take further education. Students are active subjects of development, while regulations are only a means of assisting to practice responsibility and life discipline. As development subjects, students must learn to self-regulate, therefore, the foster home also trains students to be responsible for themselves. This research was conducted at the Divine Works Bina House during 2019 s.d. 2020 to measure the four focus areas of coaching (personal maturity, spirituality, study life, and humanities) associated with community rules and events as a means of formation in the foster home so far. The research was conducted by distributing questionnaires to all residents of the Bina House in the period 2019 s.d. 2020. The results showed that most of the students understood the importance of rules in living together, spiritual life, and community life in joint formation. There are quite a number of students who experience formation at Rumah Bina. Rules in living together are needed to maintain orderly living together in the Bina House. Thankfully, the majority of respondents realized the importance of living together, the importance of spiritual events to foster their spirituality, and the need for community events to instill good habits. Orders, spiritual events, and community events are the foundation needed for joint formation.

Differences in the mechanisms of therapeutic action of platelet-rich plasma in the treatment of various joints

The paper presents the results of the application of the plasmolifting technique in the treatment of various types of musculoskeletal pathology and analyzes the possible mechanisms of the positive therapeutic effect of this technique. It is suggested that its success is in direct proportion to the composition of the tissues that make up a particular articular formation. It is supposed that the conditions for the positive therapeutic effect of the platelet auto-suspension technique include, first of all, the presence of a branched network of capillaries, which provides sufficient blood supply and, as a result, access to the sanitized tissue of granulocytic cells. The second condition is the presence of connective tissue formations containing basophils and mast cells, which, together with the endothelium of the above capillaries, secrete a sufficient amount of cytokines that trigger the therapeutic effect of this manipulation. A number of recommendations were made to increase the sanitizing effect of the plasmolifting technique on a specific joint formation.