K.I. Stepanov1, D.G. Mukhin1, S.V. Alekseenko1, and O.V. Volkova2
1Kutateladze Institute of Thermophysics SB RAS, Novosibirsk, Russia
2Saint-Petersburg National Research University of Information Technologies, Mechanics and Optics, Institute of Refrigeration and Biotechnology, St. Petersburg, Russia
E-mail: stepanov_ki@mail.ru
Keywords: lithium-bromide absorption chiller, refrigerant, lithium bromide, coefficient of performance (COP), cold of low temperatures
Pages: 481–489
The
authors have developed a method and presented experimental data for obtaining
negative temperatures of evaporation in lithium-bromide absorption
chillers driven by heat recovery. It has been found that the attainable temperature
of the refrigerated medium is the value of -5 °C.
A
mathematical model has been constructed for
determining the temperature fields and motion of the phase transition
boundaries without using the
classical Stefan condition and the concentrated heat capacity. The model makes
it possible to determine more
accurately the location of the phase transition front and may be used at the computations for layered materials in the cases
when there are several fronts, and they can merge. The modeling of the
problem on determining the melting boundary in a three-layer material has been
carried out for the one-dimensional case.
The results of dilatometric studies of thermal coefficient of linear expansion of dysprosium in the temperature range 110-1950 K are presented. The measurements were performed with an accuracy of (1.5-2.0)·10-7 K-1. The approximation dependences of thermal
coefficient of linear expansion were obtained. The reference tables of dysprosium
thermal properties for the range 110-1950 K of solid and liquid states were constructed
using the previous results obtained by the gamma method. The character of
thermal coefficient of linear expansion changes in the area of the Neel
point has been established. Its critical exponents and the critical
amplitudes have been determined. It is shown
that both above and below the Neel temperature, the experimental data cannot be
processed with a single scaling equation. A comparison with the
published data has been performed.
The authors have studied the change in the component composition of wollastonite marble from Slyudyanka deposits at increasing pressure (p
= 0.1-12000 MPa) and temperature (T = 300-6000 K). Metamorphism of marble maturation has been found. The essence
of maturation is the calcite melting, carbon dioxide deposition, the monolith compaction, the transformation
of mineral composition at pressure increase up to the value of the initial
components. When the pressure value reaches 12000 MPa the original components
are reproduced, and the maturation of marble completes. Thermodynamic analysis
reveals the secrets of the marble origin.
The quickly damped capillary waves generated at coalescence of
microdroplets (diameter of up to 100 µm), formed in a gas atmosphere at water
vapor condensation, with the horizontal layer of water are studied
experimentally. Evaporation takes place at intensive local heating of liquid
from the substrate side. To visualize and measure the deformations,
the Schlieren technique and high-speed video (up to 54000 f/s) are
applied. The measured wave amplitude varies within 1-6 µm, and this
is consistent with the magnitude of the surface energy of coalescing
microdroplets. The waves are generated by the energy of droplet surface.
The
numerical study found the effect of changes in the longitudinal and transverse
dimensions of the heater with keeping constant the area of heating on
evaporation intensity, dynamics, and extreme thicknesses of a thin liquid film
moving in a microchannel under the influence of the gas flow at local heating.
It is shown that for relatively small heating, evaporation is more intense for
the wide heaters than for the narrow ones. For the narrow and long heaters,
evaporation process is slower, but then it is intensified in a short time.
26 July 2015 is the 80th anniversary of Vladimir E. Nakoryakov, the prominent Russian scientist in the field of thermophysics and heat power engineering and the full member of the Russian Academy
of Sciences.
D. I. Nazimova1, M. E. Konovalova1, D. M. Danilina1, E. I. Ponomarev1, N. Yu. Stashkevich1, S. D. Baboy2 1V. N. Sukachev Institute of Forest, Russian Academy of Sciences, Siberian Branch, Akademgorodok, 50/28, Krasnoyarsk, 660036 Russian Federation 2Branch of the Russian Centre for Forest Protection Centre for Forest Protection of Krasnoyarsk Territory, Akademgorodok, 50a/2, Krasnoyarsk, 660036 Russian Federation
Keywords: барьерно-дождевые ландшафты, высотно-поясные комплексы, горные пихтово-кедровые леса, фитоценотическая структура, сукцессии, возобновление, barrier-rain landscapes, altitudinal-zonal complexes, fir- and Siberian stone pine mountain forests, phytocenotic structure, successions, regeneration, Western Sayan Mountains, Southern Siberia
The Ermakovsky territory research station (53°17´-52°28´ N, 92°49´-93°20´ E) has served as a long-term site for studies of mountain forest ecosystem structure and its dynamics during the last 50 years. The most interesting results of study in 2000-2014 are presented in the paper concerning biodiversity and forest succession in primary and secondary forest types forming the chern forest formation with Siberian pine (
Pinus sibirica Du Tour) and Siberian fir (
Abies sibirica L.). The data of remote sensing confirm differentiation of landscapes into altitudinal belt complexes (ABC) that are characteristic for windward macroslopes of the West and East Sayans: Scotch pine-Birch-Aspen subtaiga (
Pinus sylvestris L.,
Betula pendula Roth.,
Populus tremula L.), chern forest with (
Pinus sibirica and
Abies sibirica), mountain Siberian fir (
Abies sibirica) taiga within perhumid climate, subalpine open woodlands with (
Pinus sibirica and
Abies sibirica). They were singled out earlier with traditional methods. Position of the mountain polygon-transect (study area) in the system of natural zonation of Altai-Sayan ecoregion and its belonging to barrier-rain mountain landscapes of South Siberia are defined more exactly with help of forest inventory and remote sensing data. Initial phases of forest successions by the above mentioned four ABCs are considered with special attention to regeneration of
Pinus sibirica. In contrast to
Abies sibirica it remains weak or absent for more than 50 years. It shows unstable positions of Siberian pine in all ABCs due to high general humidity and well developed herb layers. For chern ABC, the dynamics of primary and secondary stands structure are researched on a number of representative plots with the use of tree layer, shrub layer and herb layer 1:100 mapping three times in a 45 year period. It is shown that species number and composition remain stable on permanent plots whereas synuzial diversity and the share of their participation in herb layer vary significantly and influence location of regeneration. The features of coniferous ecosystems with
Pinus sibirica and
Abies sibirica referred to chern forests correspond to the status of preserved objects due to their unique and virgin character. A number of
Pinus sibirica genetic reserves (permanent plots) are located in the chern ABC.
A. V. Benkova, D. A. Mashukov, V. E. Benkova, A. S. Prokushkin, A. V. Shashkin
V. N. Sukachev Institute of Forest, Russian Academy of Science, Siberian Branch, Akademgorodok, 50/28, Krasnoyarsk, 660036 Russian Federation
Keywords: радиальный прирост, климатические факторы, поток солнечной радиации, мохово-лишайниковый покров, термические почвенные условия, Центральная Эвенкия, Средняя Сибирь, radial increment, climate factors, solar radiation, moss-lichen cover, thermal soil properties, Central Evenkia, Central Siberia
This paper is devoted to revealing the distinctive characteristics of radial growth of larch trees (
Larix gmelinii (Rupr.) Rupr.) growing in permafrost contrast conditions of the north and south facing slopes (Central Siberia, 64°19´23˝ N, 100°13´28˝ E). Even-aged larch stems regenerated after strong fire in 1899 in opposite north and south facing slopes of the hills situated on the banks of Kulingdakan stream were under study. Two sample sites at the middle part of the slopes were established. 23 model trees in the north facing slope and 13 ones in the south-facing slope were selected for dendrochronological analysis. From each tree, disks at 1.3 m height of the stems were taken. Tree ring widths were measured, comparative analysis of dynamics of radial growth in the slopes was made. In order to separate time intervals, characterized by distinctive climate impact on radial increment, sliding response functions were calculated and analyzed. Daily solar radiation for both sample sites was calculated. The results showed that solar radiation in the north-facing slope is 20 % less than that in south-facing slope. Solar radiation regime promotes intensive thickening of moss-lichen cover, so that its thickness to 2009 was nearly two times thicker than in south-facing slope. Both factors affected the worth thermal soil growth conditions in the north facing slope. The latter was responsible for narrower ring widths formation in the stems and governed higher sensitivity of the trees to air temperature in the periods of cambium reactivation, start and intensive growth.
V. G. Storozhenko
Institute of Forest Science, Russian Academy of Sciences, Uspenskoe Village, Odinscovsky District, Moscow Oblast, 143030 Russian Federation
Keywords: коренные сосновые леса, возрастные поколения, дереворазрушающие грибы, величины пораженности древостоев, indigenous pine forests, age generations, wood-destroying fungi, volumes of affection
The author considered age structures of virgin indigenous pine forests of natural origin as well as plantations in the subzones of taiga, zones of mixed forests, deciduous forests and forest-steppe of the Russian plain. Native pine forests are heterogeneous by their structural characteristics. This heterogeneity is caused by high demands of the species to understory light requirements as well as by frequent pyrogenic influence that determine the age structure of stand forests. Virgin pine forests have up to 14 age generations and from 5 to 20 % of stand trees affected by fungi of biotrophic complex. That has a direct connection with their dynamic status. In the pine forests of digressive dynamic faze, where the initial age generations accommodate the major biomass amount, this volume may grow up to 50 %. Pine species planted discounting regularities of formation of stable forest communities are subject to spotty attacks by fungi of biotrophic complex. A species composition of wood-destroying fungi of biotrophic complex causing rot defects of pines in the entire longitudinal gradient of pine distribution within the Russian Plain stays virtually unchanged. Significant changes can be noted only in the occurrence of certain types of wood destroying fungi. The main types of wood biotrophic fungi include:
Climacocystis borealis (Fr.) Kotl. et Pouzar,
Heterobasidion annosum (Fr.) Bref.,
Phaeolus schweinitzii (Fr.) Pat.;
Porodaedalea chrysoloma (Fr.) Fiasson et Niemelä;
Phellinus pini (Thore: Fr.) A. Ames [=
Porodaedalea pini (Brot.: Fr.) Murrill]. In the uneven-aged pine forests of natural origin, mottled butt rot does not form drying out spots and exists in the stands as an ordinary component of the total biotrophic defeat. Wood-destroying fungi of biotrophic complex are evolutionary determined as one of the endogenic mechanisms of destruction of unstable forest structures and formation of stable ones. The author also evaluated the volumes of biotrophic complex’ wood-destroying fungal attack and described the features of mottled but rot (
Heterobasidion annosum (Fr.) Bref.) affection in the pine forests.
