Abstract: The present invention comprises an arrangement in a borehole. Such an arrangement comprises two tubes, an outer tube and an inner tube being arranged within each other having essentially parallel longitudinal axes. Said outer and inner tubes are connected to incoming and outgoing tubes respectively. The cross sectional area of the inner tube is less than half of the cross sectional area of the outer tube, whereby the outer tube and/or the incoming and outgoing tubes arranged in the borehole are insulated until they reach below a freezing depth of the surrounding media. Said the inner tube is also arranged to end before reaching the bottom end of the outer tube when inserted in the borehole, thus forming a fluid passage between the both tubes at the bottom end of said borehole.

Abstract: An apparatus for an exercise task includes a pneumatic arrangement, which includes a pressure source, a pneumatic controller, pneumatic transfer channels, and at least one pneumatic resistor element, which includes a pneumatic cylinder with its piston. The apparatus additionally includes a mechanical lever arm structure or another mechanical connecting structure, which is for a user's limb contact and which is at a second end connected to the pneumatic resistor element. The apparatus additionally includes a sensor structure, a calculation arrangement and a display. The sensor structure is arranged to measure at least one measurement quantity of the exercise task and, based on the measurement, the calculation arrangement is arranged to form information on the display of the apparatus, regarding the power and/or force and/or range of motion of the exercise task.

Abstract: An apparatus for an exercise task includes a pneumatic arrangement, which includes a pressure source, a pneumatic controller, pneumatic transfer channels, and at least one pneumatic resistor element, which includes a pneumatic cylinder with its piston. The apparatus additionally includes a mechanical lever arm structure or another mechanical connecting structure, which is for a user's limb contact and which is at a second end connected to the pneumatic resistor element. The apparatus additionally includes a sensor structure, a calculation arrangement and a display. The sensor structure is arranged to measure at least one measurement quantity of the exercise task and, based on the measurement, the calculation arrangement is arranged to form information on the display of the apparatus, regarding the power and/or force and/or range of motion of the exercise task.

Abstract: A collector element for collecting solar energy. The collector element is made of metal and comprises at least one elongated central ridge comprising at least one internal flow channel for a heat transfer medium, first and second elongated side ridges at opposite sides of the at least one central ridge and an elongated depression between each two adjacent ridges. At least one side ridge comprises at least one fastening element by means of which at least one substantially solar radiation permeable covering element is to be fastened to the collector element for covering at least the at least one elongated central ridge of the collector element.

Abstract: A solar collector arrangement comprises at least two solar collectors, each solar collector comprising at least one collector element with at least one flow channel for receiving heat transfer medium to be heated in the solar collector. The at least two solar collectors are arranged in parallel connection relative to each other and the heat transfer medium to be heated in the solar collectors and the heat transfer medium heated in the solar collectors are arranged to flow into the solar collectors and out of the solar collectors in turns one or some solar collectors of the solar collector arrangement at a time.

Abstract: A collector element for collecting solar energy. The collector element is made of metal and comprises at least one elongated central ridge comprising at least one internal flow channel for a heat transfer medium, first and second elongated side ridges at opposite sides of the at least one central ridge and an elongated depression between each two adjacent ridges. At least one side ridge comprises at least one fastening element by means of which at least one substantially solar radiation permeable covering element is to be fastened to the collector element for covering at least the at least one elongated central ridge of the collector element.

Abstract: The invention relates to a solar collector (1) comprising a collector element plane comprising a set of parallel metallic collector elements (2) for collecting solar energy. The collector element plane, on its side to be arranged to face the sun, comprises a set of parallel, elongated ridges (R, r) formed by the metallic collector elements (2), and elongated depressions (v) between the ridges (R, r), and that at least some of the ridges (R, r) comprise therein a channel (3) for a heat transfer medium. The invention also relates to a collector element. The invention further relates to a building roof, a building, and a solar energy recovery system comprising said solar collector (1).

Abstract: The invention relates to a solar collector (1) comprising a collector element plane comprising a set of parallel metallic collector elements (2) for collecting solar energy. The collector element plane, on its side to be arranged to face the sun, comprises a set of parallel, elongated ridges (R, r) formed by the metallic collector elements (2), and elongated depressions (v) between the ridges (R, r), and that at least some of the ridges (R, r) comprise therein a channel (3) for a heat transfer medium. The invention also relates to a collector element. The invention further relates to a building roof, a building, and a solar energy recovery system comprising said solar collector (1).

Abstract: The present invention relates to a brake arrangement (4) for a magnetic or an electric ergometer, e.g. an ergometer bike. The object of the invention is to provide an ergometer which is as user friendly as magnetic and electric ergometers, while the calibration of the ergometer is simplified considerably. The ergometer comprises a frame, a power transmission system (2) and a rotating member (3) which is driven by the power transmission system and is at least partially made of or coated with a conductive material or magnetic material a brake arrangement (4) is provided to adjust the rotation resistance of the rotating member, the arrangement consisting, according to the invention, of at least one magnetic brake member (8) which is at an adjustable distance from the rotating member. The brake member (8) has a fixed mass and is movable in a direction substantially parallel with, the cross-sectional plane of the rotating member (3) and parallel with the radius of the rotating member.