Abstract: A method for joining by welding a weld stud to a workpiece, with the following steps: providing a drawn arc welding device and a plasma gas cleaning device; providing a weld stud and providing a workpiece including a joining surface; cleaning the joining surface using a plasma gas cleaning method including the cleaning steps of: generating in the plasma gas generating device a non-transferred arc, generating with the non-transferred arc a plasma from a compressed gas, and directing the plasma onto the joining surface to remove contaminants thereon; and then, after the cleaning steps, joining the weld stud to the workpiece by drawn arc welding using the drawn arc welding device including forming of a transferred electric arc between the weld stud and the joining surface.

Abstract: A method for joining by welding or gluing joining elements to components, with the following steps: preparation of a joining element, which comprises a first joining surface, and preparation of a component, which comprises a second joining surface; preparation of the first or second joining surface; and carrying out the joining process, in which the joining element is joined to the component; wherein the preparatory step comprises at least one of the following cleaning methods for cleaning the first or second joining surface: a TIG arc method, a plasma gas cleaning method, and a snow jet method.

Abstract: A joining method for connecting a first component to a second component without pre-punching. The first component and the second component are positioned relative to one another prior to the connection by an auxiliary joining element, which is joined via a joining device to the components positioned relative to one another. The auxiliary joining element firstly passes through the first component without pre-punching and is then connected to the second component without pre-punching. Before the components are connected by the auxiliary joining element, the first component is thermally pre-treated at the joining area via an electric arc formed between the first component and an electrode of the joining device. A heat-affected zone is formed on the first component in the joining area, and the first component in is weakened or melted in the heat-affected zone.

Abstract: The invention relates to a method for connecting at least two component layers by means of a connection element. the invention to provide a particularly advantageous method for connecting at least two component layers lying on top of each other through the creation of a pilot hole in at least one cover layer. The pilot hole in the form of a through hole is made in the at least one cover layer using only a plasma jet, which cover layer is at least temporarily held in place on the base layer. Holding the cover layer and the base layer temporarily fixed to each other will allow the connection element to be placed at the same position in the base layer where the pilot hole is made. Sufficiently large layers can thus be kept in a fixed position relative to one another solely using their weight and friction.

Abstract: The invention relates to a device and a method for the dissociation of tissue. In one embodiment, the device has at least one dissociation unit, for receiving a tissue sample, which is disposed at least partially in a pot-shaped cell strainer. In addition, the invention relates, in one embodiment, to a device and a method for the dissociation of tissue, the tissue being dissociated by a grinder having mutually movable rows of teeth which cut the tissue when moving past each other in the one direction and grind the tissue when moving past each other in the opposite direction.

Abstract: A method for joining by welding or gluing joining elements to components, with the following steps: preparation of a joining element, which comprises a first joining surface, and preparation of a component, which comprises a second joining surface; preparation of the first or second joining surface; and carrying out the joining process, in which the joining element is joined to the component; wherein the preparatory step comprises at least one of the following cleaning methods for cleaning the first or second joining surface: a TIG arc method, a plasma gas cleaning method, and a snow jet method.

Abstract: A method for joining joining elements to components, in particular for stud welding, comprises the steps of: providing a joining element having a first joining surface, and providing a component having a second joining surface; preparing the first or the second joining surface, wherein the preparation step includes detecting the state of the first or the second joining surface; joining the joining element to the component. The preparation step uses least one of the following detection methods: (i) an electrical contact resistance measurement, (ii) an electrical conductivity measurement, (iii) a fluorescence measurement, and (iv) a laser measurement.

Abstract: A method for evaluating a welded between a first component and a second component comprises the steps of: bringing a first electrical pole into contact with the first component and bringing a second electrical pole into contact with the second component with the welded joint in between the first and the second pole; applying a first electrical quantity to the welded joint such that an electrical current (i) flows through the welded joint; measuring a second electrical quantity at the first and the second pole; comparing a measured value (?F; UF) of the second electrical quantity with a reference value (?0; U0); and evaluating the welded joint on the basis of the comparison step.

Abstract: A joining method for connecting a first component to a second component without pre-punching. The first component and the second component are positioned relative to one another prior to the connection by an auxiliary joining element, which is joined via a joining device to the components positioned relative to one another. The auxiliary joining element firstly passes through the first component without pre-punching and is then connected to the second component without pre-punching. Before the components are connected by the auxiliary joining element, the first component is thermally pre-treated at the joining area via an electric arc formed between the first component and an electrode of the joining device. A heat-affected zone is formed on the first component in the joining area, and the first component in is weakened or melted in the heat-affected zone.

Abstract: A method for joining a joining element onto a workpiece, in particular for stud welding or stud gluing. The method steps including providing the joining element the workpiece; detecting a characteristic variable of the workpiece or of the joining element; evaluating the characteristic variable and classifying it into one a first or a second variable class; performing the joining process, if the characteristic variable is classified into the first variable class; or performing a cleaning process on the workpiece or on the joining element and then performing the joining process after the cleaning process, if the characteristic variable is classified into the second variable class.

Abstract: A microtiter plate based cell culture system comprising an improved cell culture insert which is suitable and used for the cultivation of adherent cells and/or three-dimensional tissues.