SUBSTITUTION OF ZINC STEARATE IN COLD EXTRUSION PROCESSES

Cold impact extrusion is a kind of massive forming process for the mass production of hollow or solid parts in one or more stages. Next to steel, aluminium and its alloys are the most common materials used for the production of cold extruded parts. For the lubrication of the aluminium cold extrusion process, to prevent adhesion and to reduce tool wear, the application of zinc stearate is still widely used. Because zinc stearate is a powder it has to be applied on the slugs by a tumbling process which leads to a strong dust formation. Furthermore it may cause respiratory irritation; the thermal decomposition forms toxic and irritating vapours. This paper will present the development of a new lubricant for the cold extrusion of aluminium parts based on renewable raw materials. The new lubricant is free of zinc or other metals. Because it is a waterbased suspension, it can be applied easily and without any dust formation

SUBSTITUTION OF ZINC STEARATE IN COLD EXTRUSION PROCESSES

Cold impact extrusion is a kind of massive forming process for the mass production of hollow or solid parts in one or more stages. Next to steel, aluminium and its alloys are the most common materials used for the production of cold extruded parts. For the lubrication of the aluminium cold extrusion process, to prevent adhesion and to reduce tool wear, the application of zinc stearate is still widely used. Because zinc stearate is a powder it has to be applied on the slugs by a tumbling process which leads to a strong dust formation. Furthermore it may cause respiratory irritation; the thermal decomposition forms toxic and irritating vapours. This paper will present the development of a new lubricant for the cold extrusion of aluminium parts based on renewable raw materials. The new lubricant is free of zinc or other metals. Because it is a waterbased suspension, it can be applied easily and without any dust formation

Diagnostic immunohistochemistry for canine cutaneous round cell tumours — retrospective analysis of 60 cases

Introduction. Canine cutaneous round cell tumours (CCRCTs) include various benign and malignant neoplastic processes. Due to their similar morphology, the diagnosis of CCRCTs based on histopathological examination alone can be challenging, often necessitating ancillary immunohistochemical (IHC) analysis. This study presents a retrospective analysis of CCRCTs. Materials and methods. This study includes 60 cases of CCRCTs, including 55 solitary and 5 multiple tumours, evaluated immunohistochemically using a basic antibody panel (MHCII, CD18, Iba1, CD3, CD79a, CD20 and mast cell tryptase) and, when appropriate, extended antibody panel (vimentin, desmin, a-SMA, S-100, melan-A and pan-keratin). Additionally, histochemical stainings (May-Grünwald-Giemsa and methyl green pyronine) were performed. Results. IHC analysis using a basic antibody panel revealed 27 cases of histiocytoma, one case of histiocytic sarcoma, 18 cases of cutaneous lymphoma of either T-cell (CD3+) or B-cell (CD79a+) origin, 5 cases of plas­macytoma, and 4 cases of mast cell tumours. The extended antibody panel revealed 2 cases of alveolar rhabdo­myosarcoma, 2 cases of amelanotic melanoma, and one case of glomus tumour. Conclusions. Both canine cutaneous histiocytoma and cutaneous lymphoma should be considered at the beginning of differential diagnosis for CCRCTs. While most poorly differentiated CCRCTs can be diagnosed immunohis­tochemically using 1–4 basic antibodies, some require a broad antibody panel, including mesenchymal, epithelial, myogenic, and melanocytic markers. The expression of Iba1 is specific for canine cutaneous histiocytic tumours, and more sensitive than CD18. The utility of CD20 in the diagnosis of CCRCTs is limited.

Temporal fine structure of all-normal dispersion fiber supercontinuum

Experimental characterization of spectro-temporal structure of octave-spanning, coherent fiber supercontinuum pulses is performed and full-field information is retrieved using time-domain ptychography. Fast femtosecond oscillations are observed and traced back to imperfections of the pump pulses

Analysis of scanning force microscopy images of protein-induced DNA bending using simulations

Bending of DNA is a feature essential to the function of many DNA-binding proteins. Bending angles can be estimated with a variety of techniques, but most directly from images obtained using scanning force microscopy (SFM). Direct measurement of the bending angle using a tangent method often produces angles that deviate significantly from values obtained using other techniques. Here, we describe the application of SFM in combination with simulations of DNA as a means to estimate protein-induced bending angles in a reliable and unbiased fashion. In this manner, we were able to obtain accurate estimates for the bending angles induced by nuclear factor I, octamer-binding transcription factor 1, the human XPC-Rad23B complex

Campaigning organ donation

In dieser Bachelorthesis wird analysiert, was ein erfolgreiches Kampagnenmanagement auszeichnet. Durch die Definierung „Kampagne“ und die darauffolgende Erläuterung wird verdeutlicht, wie eine Kampagne zu leiten ist. Am Beispiel zweier verschiedener Kampagnen zum Thema Organspende werden Aufbau und Umsetzung aufgezeigt. Zum Schluss der Arbeit werden die Erfolgsfaktoren für ein gutes Kampagnenmanagement zusammengefasst

Quelles stratégies mettre en œuvre pour aider les élèves à mieux comprendre l’anglais oral ?

Professorat des lycées et collège

In-SITU monitoring of residual stress development during E-beam processing

NRC publication: Ye