A gem holder for fixedly holding a plurality of gemstones 2 during notching by means of a laser comprises a plurality of relatively flat strips 14, each having a plurality of datum notches 18 cut across at least one of its longitudinal edges, and a base plate 10, at least the upper surface of which is provided with at least one set of substantially parallel slots in which the strips are insertable...

The image signal in a radiation imaging system is improved by establishing a scattered radiation signal and subtracting the scatter radiation signal from the detected radiation signal. The scatter radiation signal is established by shielding portions of the detector and measuring radiation at the shielded portions of the detector. The total scatter radiation signal is interpolated from spatial dis...

A herbicidal composition comprising a herbicidally effective amount of N-halogenoacylanilino-fatty acid or the ester derivative thereof represented by the general formula: wherein R1 and R2 each represents C1-C4 allyl, R3 represents a hydrogen atom, alkyl having up to 10 carbon atoms, C3-C5 alkenyl, C3-C4 alkynyl or cyclohexyl, R4 represents lower alkyl substituted by 1-4 halogen atoms...

There is provided an article for use by persons lying on the ground at the sea or like locations. The device serves as a head rest for the reposing person and as a sun shade. When not in use as stated, the device serves as a carrying bag.