Totalitarianism and geography: L.S. Berg and the defence of an academic discipline in the age of Stalin

In considering the complex relationship between science and politics, the article focuses upon the career of the eminent Russian scholar, Lev Semenovich Berg (1876–1950), one of the leading geographers of the Stalin period. Already before the Russian Revolution, Berg had developed a naturalistic notion of landscape geography which later appeared to contradict some aspects of Marxist–Leninist ideology. Based partly upon Berg's personal archive, the article discusses the effects of the 1917 revolution, the radical changes which Stalin's cultural revolution (from the late 1920s) brought upon Soviet science, and the attacks made upon Berg and his concept of landscape geography thereafter. The ways in which Berg managed to defend his notion of geography (sometimes in surprisingly bold ways) are considered. It is argued that geography's position under Stalin was different from that of certain other disciplines in that its ideological disputes may have been regarded as of little significance by the party leaders, certainly by comparison with its practical importance, thus providing a degree of ‘freedom’ for some geographers at least analogous to that which has been described by Weiner (1999. A little corner of freedom: Russian nature protection from Stalin to Gorbachev. Berkeley: University of California Press) for conservationists. It is concluded that Berg and others successfully upheld a concept of scientific integrity and limited autonomy even under Stalinism, and that, in an era of ‘Big Science’, no modernizing state could or can afford to emasculate these things entirely

EVOLUTION OF THE CARBON NANOTUBE BUNDLE STRUCTURE UNDER BIAXIAL AND SHEAR STRAINS

Close packed carbon nanotube bundles are materials with highly deformable elements, for which unusual deformation mechanisms are expected. Structural evolution of the zigzag carbon nanotube bundle subjected to biaxial lateral compression with the subsequent shear straining is studied under plane strain conditions using the chain model with a reduced number of degrees of freedom. Biaxial compression results in bending of carbon nanotubes walls and formation of the characteristic pattern, when nanotube cross-sections are inclined in the opposite directions alternatively in the parallel close-packed rows. Subsequent shearing up to a certain shear strain leads to an appearance of shear bands and vortex-like displacements. Stress components and potential energy as the functions of shear strain for different values of the biaxial volumetric strain are analyzed in detail. A new mechanism of carbon nanotube bundle shear deformation through cooperative, vortex-like displacements of nanotube cross sections is reported

Influence of discrete arrangement of porous filters on pressure drop

One of the problems of the modern world is air pollution by harmful substances contained in the exhaust gases of cars. To solve this problem, diesel, and gasoline porous particulate filters are used. However, it is necessary that the porous filter create a minimum pressure drop while maintaining a high filtering capacity. The purpose of the study is to identify the feasibility of a discrete arrangement of filters to reduce the pressure drop. In this work, we carried out a study to determine the pressure drop in porous filters with porosity values ε=0.75 and ε=0.58. Experiments on measuring the pressure drop were carried out for a different number of filters (from 2 to 5), arranged continuously and discretely

ELASTIC DAMPER BASED ON THE CARBON NANOTUBE BUNDLE

Mechanical response of the carbon nanotube bundle to uniaxial and biaxial lateral compression followed by unloading is modeled under plane strain conditions. The chain model with a reduced number of degrees of freedom is employed with high efficiency. During loading, two critical values of strain are detected. Firstly, period doubling is observed as a result of the second order phase transition, and at higher compressive strain, the first order phase transition takes place when carbon nanotubes start to collapse. The loading-unloading stress-strain curves exhibit a hysteresis loop and, upon unloading, the structure returns to its initial form with no residual strain. This behavior of the nanotube bundle can be employed for the design of an elastic damper

Влияние глубокого рыхления междурядий на физические свойства дерново-подзолистой почвы и урожайность органического картофеля

The purpose of this research is to study the effect of deep loosening of row spacings on the physical properties of the soil and yield of organic potatoes. Two variants of soil cultivation were used in row spacings: usual and 25 cm deep. The soil cultivation was carried out with a row-crop chisel cultivator. Its design was developed at the institute. Analysis of the data obtained as a result of experimental studies showed that deep loosening of row spacings had a positive effect on soil compaction both in the inter-row width and directly in the plough ridge. The soil compaction in the row spacing during normal tillage was in average above 20 %, and in the ridge by an average of 13 % compared to deep tillage. The assimilation of moisture by the soil with when using of deep loosening of row spacings also had a positive trend, especially under condition of a large amount of precipitation in a short period of time. Thus, with a loss of 34 mm, the soil in the variant with loosening the row spacings in a larger volume absorbed moisture and the moisture indicators increased sharply in layers, at 15 cm by 27 %, at 25 cm by 20 %, at 35 cm by 5 %. Potato yield increased by 8.7 % when using deep loosening of row spacings. The obtained results of experimental studies should be used as recommendations when carrying out technological operations aimed at caring for potato plantings.Целью данного исследования является изучение влияния глубокого рыхления междурядий на физические свойства почвы и урожайность органического картофеля. В междурядьях использовалось два варианта обработки почвы: обычный и на глубину 25 см. Обработка почвы проводилась с помощью пропашного культиватора-глубокорыхлителя, конструкция которого разработана в ИАЭП. Анализ данных, полученных в результате экспериментальных исследований, показал, что глубокое рыхление междурядий положительно сказалось на уплотнении почвы как по ширине междурядий, так и непосредственно в гребне. Уплотнение почвы в междурядьях при обычной обработке почвы было в среднем выше 20 %, а на гребне в среднем на 13 % по сравнению с глубокой обработкой почвы. Усвоение влаги почвой с использованием глубокого рыхления междурядий также имело положительную динамику, особенно в условиях выпадения большого количества осадков за короткий промежуток времени. Таким образом, при выпадении 34 мм почва в варианте с рыхлением междурядий в большем объеме усвоила влагу и показатели влажности резко повысились в слоях, на 15 см – на 27 %, на 25 см – на 20 %, на 35 см – на 5 %. Урожайность картофеля увеличилась на 8,7 % при использовании глубокого рыхления междурядий. Полученные результаты экспериментальных рекомендуется использовать при проведении технологических операций, направленных на уход за посадками картофеля

Rate theory of acceleration of the defect annealing driven by discrete breathers

Novel mechanisms of defect annealing in solids are discussed, which are based on the large amplitude anharmonic lattice vibrations, a.k.a. intrinsic localized modes or discrete breathers (DBs). A model for amplification of defect annealing rate in Ge by low energy plasma-generated DBs is proposed, in which, based on recent atomistic modelling, it is assumed that DBs can excite atoms around defects rather strongly, giving them energy $\gg k_BT$ for $\sim$100 oscillation periods. This is shown to result in the amplification of the annealing rates proportional to the DB flux, i.e. to the flux of ions (or energetic atoms) impinging at the Ge surface from inductively coupled plasma (ICP)Comment: 18 pages, 11 figures. arXiv admin note: text overlap with arXiv:1406.394

Influence of crops of the cover crop when forming the ridge surface of landings of potatoes to dynamics of parameters of the soil state

The main factors limiting the yield and quality of potatoes are the geometric parameters of the ridge, as well as the parameters of the soil state (moisture, hardness and temperature). In this regard, the task of maintaining the optimal values of these parameters during the potato growing season is urgent. For this, it is proposed, after planting potatoes, simultaneously with the formation of ridges, to sow a cover crop (yellow mustard) on them, followed by its destruction. The purpose of this research is to study the effect of sowing cover crops during the formation of the ridge surface of potato plantings on the dynamics of soil state parameters and potato yield. As a result of the studies, it was found that the use of a new technological method ensures a decrease in the effect of erosion processes on the ridge and the preservation of its geometric parameters, which makes it possible to exclude two inter-row cultivation of potatoes, as well as stabilize the daily soil temperature in the ridge by 2-5 ° C and retain moisture by 5 - 10%, which allows to increase the yield of potatoes by 11%

Effect of organic cultivation technology on row crop yielding capacity

The study aimed to estimate the effect of organic technologies on yielding capacity of row crops in the North-West Russia and the after-effect of compost on the successor crop. Experiments took place in 2020-2022. The crop rotation included the zoned perennial grasses, potato, and table beet. Potatoes were fertilised with BIAGUM compost produced from poultry manure in a fermenter. In 2020-2021, the compost application doses were 0 (control), 4 and 8 t ha-1 (5.5 t ha-1 in 2022) or 0 (control), 80 and 160 kg N ha-1 (110 kg N ha-1 in 2022). The table beet was sown on the plots fertilised in the previous year under potatoes. The mechanical weed control of row spacing was performed twice in the growing season. Weather conditions were monitored by the own weather station near the experimental field. The year 2021 was the warmest and the driest in the study period. In 2022, the rainfall was satisfactory for crops – 238.20 mm. In control variants, the potato yields ranged from 12.78 to 20.25 t ha-1 that was 25.6-67.5% of the cultivated variety potential. Application of 4 t ha-1 of compost only slight affected the yield. But with higher compost application dose, a significant yield gain (greatest 56.88%) was observed, especially under favourable climatic conditions of 2020. The biggest beetroot average yield – from 22.5 to 27.7 t ha-1 – was also in 2020. In 2022, the average yield was from 21.5 to 24.3 t ha-1. By the study results, the applied organic technologies proved effective for producing potatoes and table beet in the North-West Russia