Survey of Period Variations of Superhumps in SU UMa-Type Dwarf Novae. VIII: The Eighth Year (2015-2016)

Continuing the project described by Kato et al. (2009, arXiv:0905.1757), we collected times of superhump maxima for 128 SU UMa-type dwarf novae observed mainly during the 2015-2016 season and characterized these objects. The data have improved the distribution of orbital periods, the relation between the orbital period and the variation of superhumps, the relation between period variations and the rebrightening type in WZ Sge-type objects. Coupled with new measurements of mass ratios using growing stages of superhumps, we now have a clearer and statistically greatly improved evolutionary path near the terminal stage of evolution of cataclysmic variables. Three objects (V452 Cas, KK Tel, ASASSN-15cl) appear to have slowly growing superhumps, which is proposed to reflect the slow growth of the 3:1 resonance near the stability border. ASASSN-15sl, ASASSN-15ux, SDSS J074859.55+312512.6 and CRTS J200331.3-284941 are newly identified eclipsing SU UMa-type (or WZ Sge-type) dwarf novae. ASASSN-15cy has a short (~0.050 d) superhump period and appears to belong to EI Psc-type objects with compact secondaries having an evolved core. ASASSN-15gn, ASASSN-15hn, ASASSN-15kh and ASASSN-16bu are candidate period bouncers with superhump periods longer than 0.06 d. We have newly obtained superhump periods for 79 objects and 13 orbital periods, including periods from early superhumps. In order that the future observations will be more astrophysically beneficial and rewarding to observers, we propose guidelines how to organize observations of various superoutbursts.Comment: 123 pages, 162 figures, 119 tables, accepted for publication in PASJ (including supplementary information

The Study of Influence of Natural Antioxidants on Quality of Peanut and Linseed Oil Blends During Their Storage

Influence of various natural antioxidants (oil extracts of sage and black currant leaves, garlic and hips) on in-storage quality of oils has been studied. Dynamics of the acid and peroxide numbers of fat of the developed oil samples was studied. Influence of natural antioxidants on preservation of polyunsaturated oleic, linoleic, linolenic fatty acids in peanut and linseed oil blends was established.When developing blended oils with an optimal fatty acid composition, it is advisable to use linseed oil which is characterized by a high content of ω-3 fatty acids. Since polyunsaturated fatty acids have a high degree of oxidation and degradation, they are unstable. This causes certain difficulties both in production and storage of vegetable oils and solving the problem of improving the product quality.It was established that the use of natural antioxidants affects preservation of quality of peanut and linseed blends, namely, organoleptic properties, acid and peroxide numbers of fat. It was proved that introduction of the studied oil extracts in an amount of 5 % increases the oxidation resistance of peanut and linseed oil blends by 1.2‒1.7 times.It was shown that to evaluate the effect of plant extracts on quality of the developed blends, it is expedient to use the content of polyunsaturated fatty acids as the main criterion. It was established that natural antioxidants contribute to preservation of 69.0‒73.0 % of linoleic acid, 73.5‒78.9 % of oleic acid and up to 82 % of linolenic acid from the initial content in peanut and linseed oil blends. The ratio of polyunsaturated fatty acids ω-6:ω-3 inall samples remained at the level of ratio of these acids in fresh blends, namely 4:1.The use of plant extracts in the formulations of peanut and linseed oil blends significantly slows down the processes of hydrolysis and self-oxidation which ensures in-storage preservation of consumer properties of new oils with an optimized fatty acid composition