Математическая модель подключения оптимального числа потенциальных потребителей тепла к тепловой сети

In the modern world, the efficient use of energy is an extremely important aspect of human activity. In particular, heat supply systems have significant economic, environmental and social importance for both heat consumers and heat supply organizations. The economic status of all participants in the heat supply process depends on the efficiency of the functioning of the heat supply systems. The reliability of the functioning of systems depends on vital processes such as the work of hospitals and industrial enterprises. With such a close network communication, reliable and efficient operation of power supply systems is critical. In this article, ways to improve the efficiency of heat supply systems are considered. A mathematical model for improved planning of heat supply systems by connecting the optimal set of new heat consumers is presented. For each single customer, when there is an alternative option for connecting this consumer to the existing heat network, it is possible to choose the only optimal solution. This becomes possible due to the restrictions and the procedure for selecting variants from a subset of binary variables corresponding to alternatives. The procedure for finding the optimal number of consumers for connection to the existing heat network is presented, which is the rationale for increasing the number of existing consumers of the heat network. The testing was carried out and the results of the mathematical model by an example of test heat networks are presented. Directions of further study of increasing the efficiency of heat supply systems and integrating the presented mathematical model with modern software complexes are determined.В современном мире эффективное использование энергоносителей является крайне важным аспектом человеческой деятельности. В частности, системы теплоснабжения имеют значительное экономическое, экологическое и социальное значение как для потребителей тепла, так и для теплоснабжающих организаций. От эффективности функционирования систем теплоснабжения зависит экономическое состояние всех участников процесса теплоснабжения. От надежности функционирования систем зависят жизненно важные процессы, такие как работа больниц и промышленных предприятий. При такой тесной сетевой коммуникации критически важно безотказное и эффективное функционирование систем энергоснабжения. В данной статье рассмотрены пути повышения эффективности работы систем теплоснабжения. Представлена математическая модель для планирования работы систем теплоснабжения путем подключения оптимального множества новых потребителей тепла. Для отдельно взятого потенциального потребителя, каждый раз, когда возникает альтернативный вариант подключения этого потребителя к существующей тепловой сети, возможно выбрать единственное оптимальное решение. Это становится возможно за счет наложения ограничений и процедуры отбора вариантов из подмножества бинарных переменных, соответствующих альтернативам. Представлена процедура поиска оптимального числа потребителей для подключения к существующей тепловой сети, являющаяся обоснованием для увеличения числа существующих потребителей. Проведено тестирование и представлены результаты работы математической модели на примере тестовых тепловых сетей, сконфигурированных на основе ручного ввода основных условий и параметров работы. Определены направления дальнейших исследований по повышению эффективности систем теплоснабжения и интеграции представленной математической модели с современными программными комплексами.         

Structural insights into thrombolytic activity of destabilase from medicinal leech

Destabilase from the medical leech Hirudo medicinalis belongs to the family of i-type lysozymes. It has two different enzymatic activities: microbial cell walls destruction (muramidase activity), and dissolution of the stabilized fibrin (isopeptidase activity). Both activities are known to be inhibited by sodium chloride at near physiological concentrations, but the structural basis remains unknown. Here we present two crystal structures of destabilase, including a 1.1 Å-resolution structure in complex with sodium ion. Our structures reveal the location of sodium ion between Glu34/Asp46 residues, which were previously recognized as a glycosidase active site. While sodium coordination with these amino acids may explain inhibition of the muramidase activity, its influence on previously suggested Ser49/Lys58 isopeptidase activity dyad is unclear. We revise the Ser49/Lys58 hypothesis and compare sequences of i-type lysozymes with confirmed destabilase activity. We suggest that the general base for the isopeptidase activity is His112 rather than Lys58. pKa calculations of these amino acids, assessed through the 1 μs molecular dynamics simulation, confirm the hypothesis. Our findings highlight the ambiguity of destabilase catalytic residues identification and build foundations for further research of structure–activity relationship of isopeptidase activity as well as structure-based protein design for potential anticoagulant drug development.</p

Model of the Connecting Optimal Number of Heat Consumers

In the modern world, the efficient use of energy is an extremely important aspect of human activity. In particular, heat supply systems have significant economic, environmental and social importance for both heat consumers and heat supply organizations. The economic status of all participants in the heat supply process depends on the efficiency of the functioning of the heat supply systems. The reliability of the functioning of systems depends on vital processes such as the work of hospitals and industrial enterprises. With such a close network communication, reliable and efficient operation of power supply systems is critical. In this article, ways to improve the efficiency of heat supply systems are considered. A mathematical model for improved planning of heat supply systems by connecting the optimal set of new heat consumers is presented. For each single customer, when there is an alternative option for connecting this consumer to the existing heat network, it is possible to choose the only optimal solution. This becomes possible due to the restrictions and the procedure for selecting variants from a subset of binary variables corresponding to alternatives. The procedure for finding the optimal number of consumers for connection to the existing heat network is presented, which is the rationale for increasing the number of existing consumers of the heat network. The testing was carried out and the results of the mathematical model by an example of test heat networks are presented. Directions of further study of increasing the efficiency of heat supply systems and integrating the presented mathematical model with modern software complexes are determined

All - d - Enantiomeric Peptide D3 Designed for Alzheimer’s Disease Treatment Dynamically Interacts with Membrane-Bound Amyloid-β Precursors

Alzheimer’s disease (AD) is a severe neurodegenerative pathology with no effective treatment known. Toxic amyloid-β peptide (Aβ) oligomers play a crucial role in AD pathogenesis. All-d-Enantiomeric peptide D3 and its derivatives were developed to disassemble and destroy cytotoxic Aβ aggregates. One of the D3-like compounds is approaching phase II clinical trials; however, high-resolution details of its disease-preventing or pharmacological actions are not completely clear. We demonstrate that peptide D3 stabilizing Aβ monomer dynamically interacts with the extracellular juxtamembrane region of a membrane-bound fragment of an amyloid precursor protein containing the Aβ sequence. MD simulations based on NMR measurement results suggest that D3 targets the amyloidogenic region, not compromising its α-helicity and preventing intermolecular hydrogen bonding, thus creating prerequisites for inhibition of early steps of Aβ conversion into β-conformation and its toxic oligomerization. An enhanced understanding of the D3 action molecular mechanism facilitates development of effective AD treatment and prevention strategies

Robotic optical telescopes global network MASTER II. Equipment, structure, algorithms

Presented paper describes the basic principles and features of the implementation of a robotic network of optical telescopes MASTER, designed to study the prompt (simultaneous with gamma radiation) optical emission of gamma-ray bursts and to perform the sky survey to detect unknown objects and transient phenomena. With joint efforts of Sternberg astronomical institute, High altitude astronomical station of the Pulkovo observatory, Ural state university, Irkutsk state university, Blagoveshchensk pedagogical university, the robotic telescopes MASTER II near Kislovodsk, Yekaterinburg, Irkutsk and Blagoveshchensk were installed and tested. The network spread over the longitudes is greater than 6 h. A further expansion of the network is considered. © 2011 Springer Science+Business Media B.V

Clusters and Nanocrystals

Clusters and nanocrystals constitute intermediates between molecules and condensed matter. Due to their finite size, clusters have a wide spectrum of applications ranging from building blocks for novel materials to model systems for fundamental investigations about light-matter interactions. Short-wavelength radiation from synchrotron radiation sources and free-electron lasers allows the detailed investigation of their geometric, electronic, and magnetic structure as well as dynamical processes. Conversely, clusters can serve as idealized sample systems for the development of new experimental techniques and pioneering experiments with novel x-ray sources. The chapter starts with a brief introduction to cluster physics, followed by a comprehensive overview of research performed at synchrotron light sources on van der Waals, metal, and semiconductor clusters. With the advent of short-wavelength free-electron lasers, a new research field in the x-ray peak intensity regime has opened. Experiments on single clusters, such as x-ray imaging and tracing ultrafast dynamics, now become possible