In vivo emission and time-resolved spectra of firefly Luciola praeusta Kiesenwetter 1874 (Coleoptera : Lampyridae : Luciolinae) have been recorded. The emission spectrum shows the FWHM value for this particular species to be 55 nm, which is significantly narrower than the in vivo half widths reported till now. The time-resolved spectrum reveals that a flash, of duration about a hundred milliseconds, is in fact composed of a number of microsecond pulses. This result suggests that the speed of the enzymecatalysed chemiluminescence reaction in the firefly for the emission of light is much faster than is believed to be.

both the kaTapayAdi and ArybhaTa's systems. This protocol is reliable and free from any kind of defect. It will go a long way in helping researchers in the field of history of Indian mathematics and astronomy, who constantly deal with such decryption processes. The automated process would not only render correctly decoded numbers, but will also speed-up the research work. Mahi, a unique herbal ink prepared with cow urine as extractant, was used for manuscript writing in early Assam. The ink had a deep and fast colour and was persistent on Sancipat manuscripts due to its resistance to aerial oxidation and fungi. It was also noncorrosive unlike the corrosive acidic iron gall ink of contemporary Europe. The present study was aimed at analysing the physico-chemical properties of Mahi, including its special properties. The study includes phytochemical analysis, antimicrobial assay, UVvisible with fluorescence analysis, iron and copper estimation and identification of some polyphenols by HPLC-UV.

Numerous investigations have been carried out on the spectral distribution of the light of different species of fireflies. Here we record the emission spectrum of the Indian species of the firefly Luciola praeusta Kiesenwetter 1874 (Coleoptera : Lampyridae : Luciolinae) on a color film. Green and red color-sectors, with an intense yellow one in between, appear in this spectrum. Intensity profile of this spectrum reveals a hitherto undetected strong narrow yellow line, which lies within the full-width-at-half maximum (FWHM) of the intensity profile. The spectrum recorded in a high-resolution spectrometer confirms the presence of this sharp intense line. This finding lends support to an earlier drawn analogy between the in vivo emission of the firefly and laser light.

Fourier transform infrared and Fourier transform Raman spectra of the kernel of the cashew nut (Anacardium occidentale) are presented. Based on the correlations with the infrared spectra of its individual components and other compounds already published, assignments of the observed bands have been done. The infrared spectrum is shown to be very similar to that of triolein, a triglyceride of oleic acid a characteristic useful in reducing the low-density lipoprotein (LDL) cholesterol level of the person consuming it.

In addition to their use as food and spice, chillies have been popular in both Ayurvedic and homoeopathic treatments since ancient times. Elemental analyses on their seeds with the help of X-ray fluorescence spectra reveal the presence of hitherto undetected magnesium, along with sulphur and chlorine. Fourier transform infrared and Fourier transform Raman spectra of the seeds reveal the presence of specific functional groups, attributed to the different bands present in the spectra. Ascorbic acid, reported to be the vitamin present in maximum amount in chilli peppers, is conspicuous by its absence in the seeds.

We have recorded in vivo emission and time-resolved spectra of the firefly species Pyrophorus noctilucus. The emission spectrum shows the FWHM value for this particular species to be 55 nm, which is significantly smaller than the half widths reported till now. The time-resolved spectrum reveals that a flash, of duration about a hundred milliseconds, is in fact composed of a number of microsecond pulses. This result suggests that the speed of the enzyme-catalyzed chemiluminescence reaction in the firefly for the emission of light is much greater than is believed to be.

The aggregation behaviour of rhodamine B (RhB) dye has been studied with the change in the concentration of the RhB in water, ethanol and propanol using absorption and laser induced fluorescence spectroscopy. The dimer and monomer fluorescence emissions were observed simultaneously in all the solvents. The monomer to dimer fluorescence intensity ratio I M I D , where IM = Monomer fluorescence intensity, ID = Dimer fluorescence intensity, has been calculated and found that at a certain concentration of RhB the magnitude of the ratio is different in different solvents. The ratio I M I D becomes equivalent to one for 1.5 gm l−1, 3 gm l−1 and 4.2 gm l−1, (gm l−1: gram litre−1) concentration of RhB in water, ethanol and propanol respectively. This concentration of RhB at which the ratio I M I D become unity is proposed as ‘critical concentration’. Above this critical concentration the dimeric fluorescence dominates and below which the monomeric fluorescence dominates. The parameter ‘critical concentration’ provides a condition of equilibrium between the monomer and their aggregates. Moreover, in the solvent for which the magnitude of critical concentration is less the fluorophore molecule aggregates more easily and vice versa. The ratio I M I D and critical concentration quantify the aggregation process of the fluorophore in the solvent. Hence, the ‘critical concentration’ value of the fluorophore (RhB) could be assumed as the characteristic parameter to study the aggregation behaviour of the fluorophore in solvents. The described method has the merit of use in the study of lasing ability and the wavelength tunability of the dye laser gain media as well as in the heavy metal sensing technology in water. This method may also be extended for other fluorophores and solvents.

Traditionally, farmers determine when a crop is ready for harvest by observing sensible attributes. They inspect the color or other physical observables which their crops exhibit and make decisions based on these observations and their past experience. This research presents for the first time a mathematical method employing Fourier-transform infrared spectroscopy to quantify the maturation or ripeness of Cameo apple based on the changes in concentrations of selected constituent components (e.g., glucose) in the apple fruit. Cameo apple fruit samples were collected from a single tree every 15 days during the last 60 days of the apple fruit maturation cycle and then analyzed with Fourier-transform infrared spectroscopy. The vibrational bands from the Fourier-transform infrared spectra were assigned to specific functional group. The peak intensities of the vibrational bands corresponding to glucose molecule were normalized and plotted against the number of days remaining before the apple fruit maturity and were observed to show a linear relationship. This relationship can be used to calculate the time required for the apple fruit to reach maturity and also to calculate the concentration of constituent components at any stage of its growth cycle.