Optimum design of four-bar function generators with minimum variance criterion

The closure equation of a four-bar linkage generally gives a nonzero result, which may be taken as an index of the error in the output for a given input. The actual output can be brought close to the desired value by specifying the mean error permissible in the entire range of operation and by minimizing the variance (standard deviation). The present method differs from the closed-form synthesis (i.e., precision-point synthesis), in the sense that it does not limit the number of precision points. The results show that the present method compares well with other methods.     

Clay mineral composition of shelf sediments off the east coast of India

The clay mineral composition of the sediments carpeting the continental shelf off the east coast of India has been determined by X-ray and Differential Thermal Analysis techniques. Sediments contributed by the Ganges-Brahmaputra system of rivers are composed of about equal quantities of chlorite and illite with a small amount of montmorillonite and a trace of kaolinite. On the other hand, sediments from near the confluence of the Godavari river are composed of a mixture of very poorly ordered clay minerals; and those derived from the Krishna river comprise illite, montmorillonite, and mixed-layers of these minerals. Sediments off Visakhapatnam, which are accumulating at a place relatively free from the influence of the terrigenous influx from the major rivers, are composed of illite, montmorillonite, mixed-layer montmorillonite and illite, with a trace of chlorite, and kaolinite. The contrasted clay mineral assemblages have been attributed primarily to the difference in the source rocks and their weathered products in the respective drainage basins of these rivers rather than to diagenesis in the marine environment.     

New emission spectrum of the TeO molecule

The spectrum of Tellurium monoxide as excited in a heavy current arc run by a 2000 volt D.C. generator was studied in the visible and ultraviolet regions. Photographs of the spectrum revealed many new bands in the regionλ 6200 toλ 3300, which are clearly degraded to longer wavelengths. Some of the bands in the regionλ 3800 toλ 3300 were identified with those of the system in the regionλ 3800 toλ 3060 (here designated as system,B-X) observed and analysed byChoong Shin Piaw. The analysis of theB-X system was extended to include some of the new bands uptoλ 4500. In addition to those assigned toB-X system, a number of new bands in the regionλ 5000 toλ 3500 constitute another system designated asA-X system. The analysis of this system has led to the following quantum formula for the band heads.v=27835+408 (v′+1/2)?4·0(v′+1/2)² ?796 (v″+1/2)+3·5 (v″+1/2)². The lower state of the two systems is common and is identified as the ground state of the TeO molecule. Bands in the regionλ 6200 to 5000 were analysed as belonging to another brief system. This system appears to arise from a transition between two escited states of the TeO molecule. The nature and properties of electronic terms responsible for the observed electronic states of the TeO molecule were discussed along with those of the related molecules O₂, SO, and SeO from considerations of electron configurations.     

Vanadametry

Summary We have found that sodium vanadate oxidises hydroxylamine quantitatively and rapidly to nitrous oxide, even at the room temperature, if the reaction is carried out in 5–6 N hydrochloric acid medium using copper sulphate as catalyst.One of the authors, K.Bhaskara Rao, desires to thank the Ministry of Education, Government of India, for the award of a ResearchScholarship, and the authorities of the Andhra University for providing the research facilities.See also Z. analyt. Chem.156, 180 (1957).     

The nuclear magnetic resonance spectra of four spin systems

The ring proton resonance spectra ofα, β andγ picolines have been studied at 40 Mc./sec. The spectra which belong to the classes ABCX, ABXY and A₂X₂ respectively have been completely analyzed to determine all the involved parameters.     

Effect of longitudinal or inplane deformation and inertia on the large amplitude flexural vibrations of slender beams and thin plates

Large amplitude flexural vibrations of slender beams, and thin circular and rectangular plates have been studied when a compatible longitudinal or inplane mode is coupled with the fundamental flexural mode. It is shown that the effect of longitudinal or inplane deformation and inertia is to reduce the non-linearity in the flexural frequency-amplitude relationship. Further, for slender beams and thin plates, the effect of longitudinal or inplane inertia is negligible.