ENCAPSULATION OF VITAMIN AEVIT OIL SOLUTION WITH β-CYCLODEXTRIN

The present work aimed at encapsulation of fat-soluble vitamin Aevit (vitamins A and E, oil) with β-cyclodextrin. Inclusion complex of vitamins A and E with β-cyclodextrin was prepared in an aqueous alcohol medium by ultrasonic treatment. The surface morphology of the resulting clathrate inclusion complexes was described using a scanning electron microscope. The results of thermographic measurements on a differential scanning calorimeter are presented. The spectral properties of the inclusion complex are characterized by 1H and 13C NMR spectroscopy data. The experimental results confirmed the existence of a complex of inclusion of β-cyclodextrin with vitamin Aevit (2:1). The activation energy of the thermooxidation destruction reaction of the clathrate complex β-cyclodextrin:vitamin Aevit was calculated, kinetic parameters of thermal destruction of clathrate were determined. These parameters were determined based on the Freeman-Carroll, Sharpe-Wentworth, Ahar and Coates-Redfern methods. The use of the above models made it possible to graphically establish the thermodynamic parameters of the thermal decomposition of β-cyclodextrin and its clathrate with vitamin. The data of thermographic measurements on a differential scanning calorimeter showed that the thermal destruction of the Aevite clathrate with β-cyclodextrin begins with the removal of water molecules from the β-cyclodextrin cavity, then the “guest” substance and the cyclic oligosaccharide are destroyed.

Accumulation of Natural Gas with a Prospective Material Based on Graphene Aerogel

The assessment of the possibility of effective use of graphene aerogels for the adsorption storage and transportation of methane is given. For the study, an aerogel based on reduced graphene oxide was synthesized using supercritical methods for processing a hydrogel in an isopropyl alcohol medium. A narrow distribution of micropores with a maximum at 0.8 nm, a narrow distribution of mesopores with a maximum at about 4.5 and 6.5 nm were revealed. The obtained graphene aerogel (GA) was used to study the adsorption of methane at pressures up to 10 MPa and temperatures of 298, 303, 313 K. The maximum gravimetric absorption of methane reaches 0.86 g/g (37 cm3 (STP)/cm3) and 2.6 g/g (109 m3 (STP)/m3) at corresponding pressures of 35 and 100 bar and a temperature of 298 K, which is the highest recorded value for porous carbon previously reported.

Spectral study of thione-thiol tautomerization of thiourea in aqueous alcohol solution

In this work we studied the equilibrium of thione–thiol tautomerization by Raman and UV spectroscopies. This type of tautomerization influences on the course and direction of the reaction between thiourea and other organic compounds. The studies were carried out in water and aqueous alcohol medium. Мethanol, ethanol, propanol-1 and propanol-2 were used as alcohols. Hydrochloric acid was used to protonate thiourea in water and aqueous alcoholic solutions. UV spectroscopy made it possible to establish the tautomer ratio in water and aqueous alcohol solutions as the ratio of the intensities of absorption bands at 236 and 200 nm. There is an increase in the content of the thiol form and a decrease of the thione form observed in the row water-methanol-ethanol-propanol-isopropyl alcohol. The addition of hydrochloric acid to the thiourea water or aqueous alcohol solutions leads to the increase of the thione form and to the decrease of the thiol form in the composition. The thione form of thiourea can be determine by Raman spectra of –C=S group. The thiol form of thiourea is difficult to detect by Raman spectroscopy due to the overlap of the –S–H bond absorption band with alcohols absorption bands.

X-RAY SPECTRAL MICROANALYSIS OF ELECTROEROSIVE POWDER MATERIAL OBTAINED IN AN ETHYL ALCOHOL MEDIUM FROM WASTE OF A NON-TUNGSTEN HARD ALLOY OF THE KNT16 BRAND

The first appearance of tungsten-free hard alloys (TFHA) was noted in the early 30s of the last century, but they did not receive due attention and, accordingly, spread due to insufficient strength and were replaced by tungsten-containing alloys of such groups as VK, TC and TTK. However, the rapidly developing shortage of expensive tungsten pushed in the late 50s to return to the search for hard alloys, the composition of which does not include tungsten. Due to the growing demand for tungsten-free hard alloys, the problem of recycling their waste with the possibility of reuse is acute in the industry. The purpose of this work was to conduct x-ray spectral microanalysis (RSMA) of powder material (PM) obtained by electroerosive dispersion (EED) in ethyl alcohol from waste of a non-tungsten hard alloy of the KNT16 brand. The resulting powder material was examined using an energy-dispersion x-ray analyzer from EDAX, built into a scanning electron microscope "QUANTA 600 FEG". In the course of scientific research, the spectra of characteristic x-ray radiation on the surface of the experimentally obtained sample were obtained. The results obtained in the course of scientific research can be used to create environmentally friendly resource-saving processes for processing waste of tungsten-free hard alloys into powder materials.

Peran Tikus Sebagai Reservoir Leptospira di Tiga Ekosistem di Kabupaten Bantul, Yogyakarta

Bantul is one of leptospirosis endemic areas which has been reported the cases every year and the presence of rats is an important risk factor relating to leptospirosis incidence in Bantul. Therefore, the role of rats as reservoir was examined in three types of ecosystems: forest, non-forest, and coastal ecosystems. Rat trapping was carried out using 100 single livetraps which were distributed in 9 locations: 2 points in the forest, 5 points in the non-forest, and 2 points in the coastal ecosystem. The rats were identified and their kidneys were collected and preserved in 70% alcohol medium. Leptospira were detected in the kidney by using PCR method. A number of 196 rats were obtained during the study. Most of them were commensal rats obtained from settlements ecosystems. Rattus tanezumi was the dominant species in the three ecosystems, but the highest infection rate of leptospira pathogen was in R.norvegicus. Coastal ecosystems were contained more infected rats, where the main habitat were mangrove forests. Based on these results, rats have great potency in leptospirosis transmission in Bantul, especially in settlements and coastal areas although leptospirosis cases were reported rarely in study area. Nonetheless, awareness of transmission should be disseminated since the presence of pathogenic leptospira in rats is very high. Keywords: leptospirosis, rat, reservoir, ecosystem, Bantul Abstrak Kabupaten Bantul merupakan salah satu daerah endemis leptospirosis yang sejak lama melaporkan kasus ini setiap tahunnya dan keberadaan tikus merupakan faktor risiko penting yang mempengaruhi kejadian leptospirosis di Kabupaten Bantul. Oleh karena itu peranan tikus sebagai hewan reservoir diteliti di tiga jenis ekosistem yaitu ekosistem hutan, non-hutan, dan pesisir. Penangkapan tikus dilakukan menggunakan perangkap tunggal sebanyak 100 buah yang disebar di 9 titik lokasi, meliputi dua titik di ekosistem hutan, lima titik di ekosistem non-hutan, dan dua titik di ekosistem pesisir. Tikus tertangkap diidentifikasi kemudian organ ginjalnya dikoleksi dan diawetkan dalam medium alkohol 70%. Bakteri leptospira dideteksi pada specimen ginjal dengan metode PCR dari total 196 tikus diperoleh selama penelitian. Sebagian besar tikus diperoleh dari ekosistem dekat pemukiman dan semuanya merupakan tikus komensal. Rattus tanezumi merupakan spesies dominan di ketiga ekosistem, namun persentase infeksi leptospira patogen paling tinggi terdapat pada R. norvegicus. Ekosistem pesisir mengandung tikus terinfeksi leptospira patogenik paling tinggi, dengan habitat utama hutan mangrove. Berdasarkan hasil ini maka tikus berpotensi besar menularkan leptospirosis di Kabupaten Bantul, terutama di daerah pemukiman dan pesisir. Meskipun kasus leptospirosis di daerah penelitian sedikit sekali dilaporkan, namun kewaspadaan terhadap penularan perlu dilakukan sedini mungkin karena leptospira patogenik yang terkandung dalam tikus tergolong tinggi. Kata kunci: leptospirosis, tikus, reservoir, ekosistem, Bantul