Abstract: A guard for an intake channel or blow channel of a power tool has a first rib with a longitudinal direction, wherein the first rib has a first rib section that extends along the longitudinal direction of the first rib from a first end to a second end of the first rib section. The first rib section has an inherent frequency. One or more first disruptive bodies are arranged on the first rib section between the first end and the second end of the first rib section. The first disruptive bodies are configured to translatorily vibrate together with the first rib section. The first rib section and the one or more first disruptive bodies form a vibration system with a system inherent frequency, wherein the inherent frequency of the first rib section is different from the system inherent frequency.

Abstract: A connecting tube guides an air flow from a blower of a handheld work apparatus to a catcher bag. The connecting tube is curved in an arcuate manner in a plane of curvature and has an inlet opening and an outlet opening. The air flow in the connecting tube is deflected in the plane of curvature along a longitudinal center line by at least 70°. The connecting tube has flow cross-sections oriented perpendicular to the longitudinal center line, each having an inner height measured perpendicular to the plane of curvature. The connecting tube has a center flow cross-section oriented perpendicular to the longitudinal center line halfway between the inlet opening and the outlet opening. Each flow cross-section has an inner width in the direction perpendicular to its inner height. The inner height of the center flow cross-section is greater than the inner width of the center flow cross-section.

Abstract: A portable work apparatus comprises a housing (2) and a tool (9). A drive motor (5) is arranged in the housing (2) between the first end (3) and the second end (4) and has a drive shaft (7) for driving the tool (9). The drive motor (5) has a first bearing (12) and a second bearing (13). The drive shaft (7) is rotatably (11) supported relative to the housing (2) by means of the first bearing (12) and the second bearing (13). A drive transmission unit (8) is functionally arranged between the drive motor (5) and the tool (9). The work apparatus (1) has additional bearing (14) for supporting the drive shaft (7) relative to the housing (2) of the work apparatus (1) arranged on the drive shaft (7).

Abstract: The disclosure relates to a method for sound adaptation, via a sound generator, of a handheld work apparatus driven by an electric drive motor and to a handheld work apparatus with a sound generator configured for this purpose. The work apparatus generates during operation an uncorrected operating sound. Via the sound generator, during operation a supplementary sound is generated in addition to the uncorrected operating sound and is overlaid on the operating sound to form an overall sound with an overall sound pressure level (LGp). In this case, the main component of the supplementary sound lies in an adaptation frequency spectrum (fA) below 1 kHz.

Abstract: A guard for an intake channel or blow channel of a power tool has a first rib with a longitudinal direction, wherein the first rib has a first rib section that extends along the longitudinal direction of the first rib from a first end to a second end of the first rib section. The first rib section has an inherent frequency. One or more first disruptive bodies are arranged on the first rib section between the first end and the second end of the first rib section. The first disruptive bodies are configured to translatorily vibrate together with the first rib section. The first rib section and the one or more first disruptive bodies form a vibration system with a system inherent frequency, wherein the inherent frequency of the first rib section is different from the system inherent frequency.

Abstract: The invention provides new and alternative fructose-6-phosphate aldolase (FSA) variants which enable the production of optically active building blocks with high chemoselectivity and stereoselectivity using aldehydes as starting material in aldol carboligation reactions, while avoiding the by-product formation and subsequent reactions.

Abstract: A suction device is provided which includes a fan device for generating a suction air flow and an air conveying device having at least one flow deflection element comprising an inlet tube and an outlet tube, wherein the outlet tube is oriented transversely to the inlet tube, and wherein in a transitional area between the inlet tube and the outlet tube there is arranged a sound mirror device, which at least one of (i) reflects and (ii) absorbs sound.

Abstract: A suction device is provided which includes a fan device for generating a suction air flow and an air conveying device having at least one flow deflection element comprising an inlet tube and an outlet tube, wherein the outlet tube is oriented transversely to the inlet tube, and wherein in a transitional area between the inlet tube and the outlet tube there is arranged a sound mirror device, which at least one of (i) reflects and (ii) absorbs sound.