Abstract: The conformation of optically active molecules is investigated by projecting a monochromatic and unpolarized beam of light into a sample cell containing such molecules for causing the latter to luminesce, providing optical modulating means for intensity modulating polarized light in the radiation incident on the modulating means, beaming a portion of the luminescent output of the sample cell on the modulating means in such a way as to minimize the amount of linearly polarized light incident on the modulating means, and measuring the intensity of light at a predetermined wavelength emerging from the modulating means. The luminescent output of the sample cell incident on the modulating means contains a small amount of circularly polarized light in the presence of a large amount of unpolarized light.

Abstract: A manually resettable valve comprises a valve body having a cylindrical portion with a wetted enclosure defined by an internal coaxial aperture within which a magnetically attractable plunger is slidable between two terminal positions establishing the states of the valve. A spring urges the plunger toward a first terminal position; and an electromagnet mounted on the body and responsive to an electrical signal when the plunger is in its first terminal position magnetically attracts the plunger and moves it to a second position against the action of the spring. Finally, a permanent magnet in a magnetic circuit, whose elements include the cylindrical portion of the body and the plunger, holds the plunger independently of the electromagnet in its second terminal position thereby holding the valve in its "latched" state.

Abstract: An elongated dripper unit comprising an enclosure sealed at either end thereof and formed with a liquid inlet and outlet, at least one longitudinal partition formed in said enclosure so as to divide the enclosure into at least two sub-enclosures and a plurality of lateral partitions each of which extends laterally across the other enclosure from the enclosure wall to an inner longitudinal partition so as to subdivide each sub-enclosure into a plurality of cells which communicate with each other via reduced-diameter communicating apertures formed in the longitudinal partition(s), said cells including an input cell communicating with said inlet, an output cell communicating with said outlet and a plurality of intermediate cells, a liquid flow path through said unit extending from said input cell to said output cell via said plurality of intermediate cells, the liquid pressure through said unit being progressively reduced as a result of passage through said communicating apertures and as a result of repeated abr

Abstract: A seed planting unit carries a seed planter that dispenses a predetermined amount of seed into the ground at predetermined intervals in response to the coupling between a ground engaging wheel supporting the unit and the drive means of the seed planter. A film dispenser is also carried by the unit for laying film on the ground over the planted seeds; and a transmission is provided for synchronizing the perforating of the film before it is laid with the dispensing of the seeds by the seed planter so that the apertures in the film are aligned with the seeds deposited in the ground.