Open Ground Collections of Saint Petersburg Botanic Garden for the Benefit of Botanic and Environmental Education

Botanic gardens with their rich collections and scientific resources have a unique potential that attracts the attention of the society to the problems of preserving biodiversity, ensuring environmental education, conserving nature, providing leisure, serving the place for relaxation and entertainment. One of the oldest Botanic gardens of Russia is the Saint Petersburg Botanic Garden of the Komarov Botanic Institute of the Russian Academy of Sciences demonstrates the experience of utilizing the open ground collections for Botanic and environmental education. The experts share various aspects of interaction between a Botanic garden and its visitors. The paper provides examples of excursions and other forms of work on the open ground. The paper analyzes the experience of foreign colleagues related to the motivation for visiting Botanic gardens by different age and social groups. The authors provide data of sociological surveys of visitors and the analysis of their motives to visit the Saint Petersburg Botanic Garden in particular. It also shows the growth of interest in the open ground collections

Multispectral analysis of Northern Hemisphere temperature records over the last five millennia

Aiming to describe spatio-temporal climate variability on decadal-to-centennial time scales and longer, we analyzed a data set of 26 proxy records extending back 1,000–5,000 years; all records chosen were calibrated to yield temperatures. The seven irregularly sampled series in the data set were interpolated to a regular grid by optimized methods and then two advanced spectral methods—namely singular-spectrum analysis (SSA) and the continuous wavelet transform—were applied to individual series to separate significant oscillations from the high noise background. This univariate analysis identified several common periods across many of the 26 proxy records: a millennial trend, as well as oscillations of about 100 and 200 years, and a broad peak in the 40–70-year band. To study common NH oscillations, we then applied Multichannel SSA. Temperature variations on time scales longer than 600 years appear in our analysis as a dominant trend component, which shows climate features consistent with the Medieval Warm Period and the Little Ice Age. Statistically significant NH-wide peaks appear at 330, 250 and 110 years, as well as in a broad 50–80-year band. Strong variability centers in several bands are located around the North Atlantic basin and are in phase opposition between Greenland and Western Europe

Mathematical modelling of enhanced gas production

Abstract Based on a mathematical model for 2D filtration of a two-phase multicomponent hydrocarbon mixture, the boundary problem of optimizing distribution of well flow rates was for the first time composed and solved so as to maximize the gas recovery from a natural gas reservoir at its final stage of development. The input data used in the model are the planned gas production in the reservoir and reservoir characteristics (its thickness, porosity, and permeability). The flow rate optimization in individual wells is carried out in such a way that the pressure drop is kept constant for the recharge area of each well. The proposed optimization algorithm takes into account both the restriction on the flow rates in certain wells and their shutoffs for remedial maintenance. The own computer program has been developed to solve the problem. The efficiency of this approach is illustrated by the example of the natural gas reservoir Kotelevske (Ukraine). It is shown that the control of the pressure equalizing process in the recharge area of each well leads to the decrease in differential pressure inside the whole reservoir. As a result, the 6% increase in gas production was possible for the optimum alternative in a shorter period of time