A comparative study of scintillation analysis over two line-of-sight paths at 6.7 GHz and 7.6 GHz

A comparison of the signal intensity fluctuations or scintillation of signal level, observed over two line-of-sight links is presented. These links are situated over Calcutta, DumDum-Andul (6.7 GHz) and Delhi, Delhi-Sonepat (7.6 GHz). The study reveals departures, in the occurrence and variation of the scintillation over the Calcutta path as compared with the path over Delhi. This deviation has been attributed to the large variation in humidity which exists in the coastal region, and also which plays a major role in microwave propagation in the troposphere.     

Polarographic studies on the coupled product of β-diketones with aryl diazonium chloride

Polarographic reduction of some coupled product of acetyl acetone with aryl diazonium chloride takes place in a single 4-electron transfer, giving a diffusion controlled irreversible waves in B.R. buffers of pH range 2–11.8. The reduction in these compounds takes place at the ---NH---N=C bond. Effect of various cations, anions, surfactant and solvent percentage on the reduction has been discussed.     

Correlation Between Atmospheric Radio Noise-Burst Amplitudes with Different Bandwidths

Correlation between atmospheric radio noise-burst amplitudes measured by the Aiya noise meter with different bandwidths was examined during periods of local thunderstorm activity. The investigations were carried over a frequency range of 100 kHz to 9 MHz and over a 6-dB bandwidth range of 300 Hz to 16 kHz. The correlation observed in all cases was so high that the standard error of estimate was nearly equal to the accuracy of measurement itself. This suggests that the phenomenon is deterministic rather than statistical. The practical utility of the result is discussed.     

DISPERSION OF MATTER IN FLOW OF A BINGHAM PLASTIC IN A TUBE

The paper is concerned with the dispersion of a solute in a Bingham plastic fluid flowing in a pipe or a parallel plate channel. For pipe flow, the dispersion coefficient K₂ first increases with ξ₀ (the dimensionless radius of the plug flow region), reaches a maximum and then decreases. But in a channel flow, K₂ decreases monotonically with increasing ξ₀. Further K₂ for channel flow is found to be larger than that for pipe flow for all values of ξ₀ except 0.8≤ξ₀≤1.     

Studies on biosynthesis of waxes by developing jojoba seed. II. the demonstration of wax biosynthesis by cell-free homogenates

The following enzyme activities were demonstrated in cell-free homogenates from developing jojoba cotyledons: 1) elongation of long chain acyl-CoAs in the presence of malonyl-CoA and NADPH (or NADH), 2) NADPH-dependent reduction of long chain acyl-CoAs to the corresponding alcohols, 3) esterification of long chain acyl-CoAs and the alcohols produced from them into wax, 4) elongation of stearoyl-ACP to eicosanoate and docosanoate as well as reduction to stearyl alcohol, 5) desaturation of stearoyl-ACP to oleate in the presence of reduced ferredoxin, and 6) incorporation of malonyl-CoA into long chain fatty acids and alcohols in the presence of added acyl carrier protein. These activities were associated entirely with the floating wax pad after centrifugation of the cell-free homogenate at 12,000 g for 20 min. The relevance of the above reactions (1–6) to wax biosynthesis in vivo is discussed. Production of oleate from acetate by enzymes utilizing ACP-thioesters as substrates followed by conversion of oleyl-ACP to oleoyl-CoA (via free oleic acid) for subsequent elongation, reduction, and esterification, is presented as the most probable in vivo pathway, for wax biosynthesis. The substrate specificities of the elongation and reduction reactions utilizing acyl-CoAs as substrates are examined in terms of wax composition.     

Damping studies of aging in Al-Cu

Precipitation in an Al-3 pct Cu age-hardening alloy has been monitored at 130°C by ultrasonic pulse-echo measurements of attenuation and sonic velocity at 15 to 75 mHz and resonance bar damping and dynamic modulus measurements at 80 kHz. The use of two internal friction measurement techniques allows separation of the total damping loss into its component parts. Damping and modulus defect remain constant with time up to 100 hr, whereupon they begin to increase and reach a maximum at 250 hr. The observed time dependence is associated with scattering losses by precipitate particles and with increasing dislocation damping as dislocations become increasingly mobile during the depletion of their solute atmospheres by growing solute-rich precipitates.     

Present prognosis in neonatal meningitis

A retrospective study of neonatal meningitis for a period of 6 years (1970 to 1975) is described. It was found that though the survival rate had increased since the introduction of the aminoglycosides, it was at the expense of major neurological sequelae in the survivors. It is suggested that breast feeding of all infants in the first few days of life will reduce the incidence of neonatatl meningitis. It is recommended that pooled human breast milk should not be heat-sterilized as this destroys anti-Escherichia coli immunoglobulin A.     

Solar device for the candle industry

A solar device has been developed for manufacturing candles from paraffin wax, utilizing solar energy. The design, operation and performance of the device have been described. It is concluded that the device can be used for saving fuel, minimizing the loss of wax due to the vaporization and labour.     

Viscosity-molecular weight concentration relationships beyond the critical region in polymer solutions and melts

A multivariate regression analysis of viscosity-molecular weight-concentration data is presented which is superior to the methods currently used. Four sets of data from the literature are analysed to show the efficacy of the method.     

The effect of zinc and phytic acid on the incorporation of 1-14C-acetate into aflatoxin by resting mycelia of Aspergillus parasiticus.

The effect of zinc and phytic acid on [1-14C]-acetate incorporation into aflatoxins by resting mycelium was studied. When different levels of ZnSO4 were used to study its effect on the incorporation of [1-14C]-acetate into aflatoxins, it was found that the specific radioactivity incorporation into aflatoxins was maximum at the level of 10 mM-ZnSO4. At this concentration the change in the specific radioactivities of aflatoxins B1 + B2 and aflatoxins G1 + G2 were +74.61% and +29.66%, respectively. On the other hand, phytic acid had an inhibitory effect on the incorporation of [1-14C]-acetate. These observations have been correlated in order to find out why soyabean is unable to produce aflatoxins by Aspergillus parasiticus.