Spectroscopic and Microscopic Studies of Archaeological Celadons Recently Excaveted From Alagankulam, Tamilnadu, India

Ceramics are the most common archaeological material used by the historians to draw chronological and cultural characterizations. Among these, porcelains and celadons are recognized as good historical relics. Moreover, the different facets of science, technology and culture are also imprinted in these samples. Hence, the knowledge of microstructures, compositions and technologies used can be helpful in identifying and dating the ancient artifacts. In this paper,  three representative celadon samples found in the course of archaeological excavations at the site Alagankulam, Ramanathapuram District, Tamilnadu, India were investigated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and Scanning electron microscopy (SEM) in order to  achieve their mineralogy and chemical behavior. X-ray diffraction was used to accomplish possible crystalline mineral phases within the clays that composed of samples.  On the other hand, FT-IR studies helped in identifying the different mineral assemblages from the tentative vibrational assignments of absorption bands. Microstructure and one or multi step firings can be inferred from the SEM

Archaeomagnetic Study and Dating of Tittakudi Archaeological Site in Tamilnadu, India

Archaeomagnetic dating study has been carried out for the fragmented archaeological pottery samples collected from Tittakudi archaeological site in Tamilnadu. Various Mineral magnetic studies have been performed. The results obtained from the study showed all are highly magnetically enhanced except few samples. The samples having stable remanent property undergone paleointensity measurement and the mean paleointensity value of the sample is found to be 42.44± 0.2 mT and its age predicted around 170 BCE

Mineralization changes substituted type B carbonate of PO43− ion in the bone minerals of an archaeological sample studied using fourier self deconvolution technique

277-282The aim of this study was to describe the compositional changes in the archaeological specimen using FTIR. Fourier deconvolution was applied in the carbonate (500-650 cm−1), phosphate (900-1200 cm−1), and in the amide region (1700-1600 cm−1). The deconvolution of the spectra in the phosphate region 1200-900 cm−1 reveals six components 960 cm−1, 1010 cm−1, 1020 cm−1, 1030 cm−1, 1110 cm−1 and 1120 cm−1. The bone mineral such as CO32−, PO43− particle, collagen, and organic materials were studied in detail from the infrared spectra. The computed parameters such as collagen development, mineralization index, C/P proportion, crystalline index, and maturing of bone help us in characterizing the bone samples. The Low estimation of C/P proportion resulted in changes in Type B carbonate (PO43−) substitution. The absence of phosphate band ~1100 cm−1 and formation of β sheet structure were observed in the samples studied. Increased level of mineralization resulted in the increased in the crystalline nature of the bone samples. The study indicates the utilization of FTIR using self deconvolution technique which helps in understanding the compositional changes in the archaeological sample

Investigation of molecular interactions of antibiotic Doxycycline Hyclate with palmitic acid

            The Dilute solution viscometric technique is employed to find the molecular interactions between the non-Newtonian Doxycycline hyclate and the essential saturated fatty acid, Palmitic acid in the common solvent Ethyl methyl ketone. The viscometric parameters µ, α and β identifies the molecular interactions at physiological temperatures. The conformity of interaction has been attempted by the ultrasonic velocity; and the related acoustical parameters at temperatures 303, 310 and 313K. The chemical nature of the blend solutions have been identified through refractometric technique. The behaviour of these parameters explains the molecular interactions on the basis of solute-solute and solute-solvent interactions

FTIR and FT-Raman spectroscopic studies of fired clay artifacts recently excavated in Tamilnadu, India

501-508The spectroscopic techniques represent one of the most powerful tools to investigate the structure of all the materials and chemical composition of the cultural objects like potteries, tiles and ceramics. The spectroscopic techniques that have been used in the present study are FTIR absorption and Raman scattering spectroscopy. The potteries maintain aesthetic characteristics so that this type of artifacts can be considered very specific trace of every civilization. Therefore, it is of great importance to acquire knowledge about the chemical composition and the manufacturing techniques of an artifact. From the behaviour of the absorption bands and their corresponding Raman shifts in specific regions and their intensity showing the presence of minerals, traces of elements in the clay, the knowledge of the artisans and the conditions of the temperature control to make qualitatively good materials of archaeological artifacts. The temperature of firing and the vitrification stage are also being established in the case of potteries from the recent excavations at Maligaimedu, Thiruverkadu and Palur in Tamilnadu, India

Experimental Energy And Exergy Analysis Of A Flat Plate Solar Air Heater With A New Design Of Integrated Sensible Heat Storage

This paper presents an experimental energy and exergy analysis of a novel flat plate solar air heater (SAH). It has a specially designed absorber plate made up of copper strips (copper tubes with extended copper fins on both sides), welded longitudinal to one another. This structure acts as an integrated absorber-cum-storage unit, where a high quality synthetic oil (Therminol-55) is filled within those copper tubes as a sensible heat storage (SHS) medium. To study the impact of this novel design and the sensible heat storage over the performance of the SAH, the results were compared with the output of a conventional SAH of similar dimensions. For the precise comparison of their performances, the experiments were conducted on both the SAHs at same location, simultaneously. It ensures identical testing conditions such as the amount of solar radiation received and surrounding environment of the experimental setup. Exergy analysis is a powerful thermodynamic tool and it helps in computing the actual output of a system, theoretically. It helps the researchers to optimize the system design to compensate the present and also the future needs. Experiments were conducted for two different mass flow rates (0.018 kg/s, and 0.026 kg/s). The results showed that the maximum energy and exergy efficiency obtained was in the range of 49.4-59.2% and 18.25-37.53% respectively, for the SAH with sensible storage at m = 0.026 kg/s. Besides, the SAH with sensible heat storage was observed to perform better than the conventional flat plate SAH without storage

Review of solar cooling methods and thermal storage options

Power shortage and unstable power supply remain serious problems. Conventional cooling technologies that utilize harmful refrigerants consume more energy and cause peak loads leading to negative environmental impacts. As the world grapples with the energy and environmental crisis, there is an urgent need to develop and promote environmentally benign sustainable cooling technologies. Solar cooling is one such promising technology, given the fact that solar energy is the cheapest and widely available renewable energy that matches the cooling load requirements. Thermal storage systems are essential to overcome the disadvantage of the intermittent nature of solar energy and variation in cooling demand. The enhanced utilization of solar energy and other consequences of thermal storage integrated systems have gained the attention of researchers in the recent years. This paper reviews research articles in the field of solar cooling techniques, solar collectors, storage methods and their integration, along with performance improvement studies reported using thermal stratification and cascaded thermal storage systems.Solar cooling Absorption cooling Solar collectors Thermal energy storage Phase change material Latent heat thermal storage