Novel ultra-fast luminescence from incipient ion tracks of insulator crystals: electron–hole plasma formation in the track core

Measurements of fast luminescence decay and time-resolved spectra revealed novel ultra-fast luminescence with the lifetime of several tens ps in heavy-ion-irradiated single crystals of LiF, NaF, NaCl, KCl, KBr, KI, RbI, CsCl, CsBr, CsI, -alumina, and MgO. The luminescence is furthermore characterized by a super-linear increase in the efficiency with increasing excitation density, non-tailed decay curve, and temperature-insensitive decay-rate and yield. The results mean that the luminescence neither originates from localized excited states such as self-trapped excitons, free excitons, excited defects, and excited impurity centers nor their interaction. A process which does not contradict the experimental results is the formation of the e–h plasmas and the luminescence from them.     

E.p.r. studies on dichloromono(1-phenylamidino-o-alkylurea)copper(II) complexes. Evidence for field induced partial ordering in the solid state and some unusual features in solution

E.p.r. and optical absorption studies have been conducted on dichloromono(1-phenylamidino-o-alkylurea)copper(II) complexes (Alkyl = Me, Et, Pr, Bu or Pe). The e.p.r. spectra of solids, recorded at 300 K, confirmed the square-planar geometry with the unpaired electron in the dx ²–y ² orbital of copper. Magnetic field-induced partial molecular alignment has been observed in some of the polycrystalline samples when cooled in a magnetic field of 1 T at 77 K. E.p.r. spectra at 77 K in pyridine and DMF has shown axial ligation of solvent molecules (pyridine and DMF), whereas in MeOH and DMSO at least three structurally different Cu^II species have been identified. These features are consistent with differences in electronic absorption spectra in the powder and in solution.     

Matching tyre size to weight, speed and power available for maximising pulling ability of agricultural tractors

The desirable weight-to-axle power ratio for agricultural tractors is determined by the necessity for the optimum utilisation of the available axle power to produce the required drawbar pull at a preselected slip. For a vehicle designed to operate in a given speed range, the weight-to-axle power ratio should be within a particular limit, so that a specific level of conversion efficiency can be maintained. In this paper attempts have been made to select suitable tyres for Indian two-wheel drive tractors operating in sandy clay loam soils on the basis of weight-to-power utiisation and maximum pull-to-optimum weight ratio at a preselected slip using the developed traction prediction equations. A comparison has also been made between the desired and actual weight on a single traction wheel and suitable tyre and tyre normally fitted in Indian two wheel drive tractors up to 35 kW.     

A Facile and Convenient Method for the Synthesis of 8-Methoxy 10,11-Dihydronaphtho [1,2-b]Quinolines

Dihydronaphthoquinolines are relatively rare polycyclic heterocyclic compounds. We wish to report a simple and convenient preparative method for hitherto unknown compounds with these new structural features. 6-methoxy tetralone¹ (I) 3.5g (.02 mole) in 3 ml DMF was added slowly to 4.6g (.02 mole) of POCl₃ in 3ml DMF at 0°C. The mixture was stirred for 5 hrs. and the temp. was then gradually raised from 0° to 60–65°C. The resultant complex was treated with aq. sodium acetate solution till pH5–6 was reached. The extract on usual purification, furnished 3.2g (80°%.) of 1-chloro, 6-methoxy, 1,2,3,4 tetrahydro naphthalene-2-aldehyde(II)⁺²     

Comparative study of different application methods of 14C-Fosthiazate in tomato plants

A comparative study of different application methods of nematicide ¹⁴C-Fosthiazate was done for the uptake in tomato plants in two varieties Pusa Ruby and Pusa Early Dwarf. The application methods used for the research purpose are seed treatment, soil supplication and drip application in presence and absence of surfactant (Tween-80).It as found that percent absorption was the highest in the drip irrigation method in presence of surfactant. The percent uptake of ¹⁴C-Fosthiazate in two varieties of tomato plants was found to be higher in Pusa Early Dwarf in all the treatment methods.     

Heterocyclic compounds. XI. Potential post-coital antifertility agents

A series of heterocyclic analogs of diarylethylene and triarylethylene were synthesized as potential anti-implantation agents. Tested in rats as oral, post-coital antifertilily agents, a few of our compounds showed some activity.     

Coulometric determination of uranium in perchloric acid medium and its applications

Amorphous samples of a new inorganic ion exchanger, cerium(IV) selenite have been prepared under varying conditions. The material prepared by mixing 0.025M ceric sulfate and 0.025M sodium selenite in the ratio of 11 was studied in detail for its ion-exchange capacity, chemical stability, IR, thermogravimetry and K_d values. Separations of metal ions have been performed on columns of this ion exchanger.     

Polymerization of para-xylylene derivatives (parylene polymerization). I. Deposition kinetics for parylene N and parylene C

Kinetic aspects of parylene N [unsubstituted poly(para-xylylene)] and Parylene C [monochlorosubstituted poly(para-xylylene)] were studied. The conversion of starting material (dimer of either p-xylylene or chloro-para-xylylene) to polymer is quantitative (ca. 100%). Consequently, the total polymer formed in a closed system is directly proportional to the amount of dimer charged. However, the percentage of the total amount of polymer formed which deposits on substrate surfaces, placed in the deposition chamber, as well as the polymer film growth rate are dependent on operational factors such as the temperature of the substrate, sublimation of dimer temperature, flow pattern of the reactive species, etc. Parylene C, being a heavier and more polar molecule, has the tendency to deposit easily in the deposition chamber compared to the deposition of Parylene N. Parylene C also has a higher ceiling temperature for deposition than Parylene N. This situation has been investigated from the viewpoint of excess thermal energy which hinders polymer formation (deposition) due to the exceedingly high entropy change necessary for polymer deposition to occur. The addition of a cool (i.e., room temperature) inert gas was shown to increase the deposition of Parylene N on substrate surfaces placed in the deposition chamber. The deposition increase and acceleration of deposition (film growth) rate were found to be related to the size and molecular weight of the inert gas pressure maintained in the system. The accelerating effect is explained by the increase in third-body collisions to dissipate the excess thermal energy of the reactive species.