Identification of Quasi-Stationary Dynamic Objects with the Use of Derivative Disproportion Functions

This paper presents an algorithm for designing a cryptographic system, in which the derivative disproportion functions (key functions) are used. This cryptographic system is used for an operative identification of a differential equation describing the movement of quasi-stationary objects. The symbols to be transmitted are encrypted by the sum of at least two of these functions combined with random coefficients. A new algorithm is proposed for decoding the received messages making use of important properties of the derivative disproportion functions

Методичні підходи до визначення модельних підприємств лісового господарства

The forestry enterprise is affected by both socio-economic and natural and climatic factors. At present, current issues for forest enterprises in Ukraine are to determine the normative (optimal) organizational and economic parameters of their activities by region and bring them in line with the real economic conditions of functioning. The methodical approach to identification of model forestry enterprises (leaders) by regions is considered in the paper. The authors have substantiated the necessity to allocate enterprise leaders in the forestry sector who can become exemplary for the industry, and will contribute to the growth of their investment attractiveness and competitiveness. The proposed methodology is based on the scenario approach in the methodology of economic activities management of enterprises in the industry and uses methods of economic comparative analysis. Model forest enterprises are the most efficiently working ones in the relevant natural zones whose parameters are the base for theoretical models with forest management optimization systems. Model enterprises are determined by groups of criteria, which reflect the impact of the most significant factors of economic, forestry and ecological, socio-economic components of their activities. It should be noted that the main goal of transformations in the forest industry is balanced development of the forest sector of the economy, which combines forest-ecological, economic and social components. Forecasting of activity parameters of forest enterprises by regions performed according to reliable multi-factor models with six groups of the most important impact factors. The proposed six groups of indicators provide generalized information on the organizational and production structure of forest enterprises, volumes of resources and their use, the competitiveness of forest products, and the effectiveness of enterprises by socio-economic criteria. Comparison of performance indicators of model enterprises with other enterprises can determine the normative parameters of forest management by the region. The developed methodical tools have been tested at forest enterprises of four regions of Ukraine such as Vinnitsa, Sumy, Kharkiv and Chernihiv.Підприємства лісового господарства зазнають впливу не лише соціально-економічних, а й природно-кліматичних чинників. На сьогодні актуальним питанням для підприємств лісової галузі України є визначення нормативних (оптимальних) організаційно-економічних параметрів їх діяльності за регіонами та їх уповільнення до реальних економічних умов функціонування. Розглянуто методичний підхід до визначення за регіонами модельних лісогосподарських підприємств (лідерів). Запропонована методика спирається на сценарний підхід у методології управління господарською діяльністю підприємств галузі та використовує методи міжгосподарського порівняльного аналізу. Прогнозування параметрів діяльності лісогосподарських підприємств за регіонами здійснюється за достовірними багатофакторними моделями з шістьма групами найвагоміших факторів впливу. Запропоновані оптимальні багатофакторні моделі організаційно-економічної діяльності лісогосподарських підприємств містять такі параметри: ресурсно-виробничого потенціалу (потужності), еколого-економічної (лісівничо-екологічної та економічної складових) та соціально-економічної ефективності (соціальної значущості для власних працівників та економіки регіону) за шістьма групами критеріїв. Запропонований методичний підхід апробовано на лісогосподарських підприємствах чотирьох областей України (Вінницької, Сумської, Харківської та Чернігівської)

Економічне обґрунтування віків головних рубок деревостанів

One of the most important economic problems in forestry is the definition of the ages of the principal felling of forests on the basis of established rotation stand ages. The main disadvantages of exploitability ages of stands of forestry species acting in the country under silvicultural and economic criteria are considered. In order to eliminate forestry inventory deficiencies in the established exploitability ages and in the optimal ages of felling in the forests of Ukraine on replacing the current ages of maturation, a new draft of rotation ages of stands has been developed. When establishing the rotation ages of stands and the age of felling, complex use of quantitative and cost (monetary) indicators is necessary; this will allow determining objectively the forestry and economic efficiency of forest exploitation. Therefore, there is a need for a monetary valuation of wood stocks at the principal felling and a comparison of the cost of existing and project rotation ages of stands. The method of economic estimation of forest stands stock by rotation ages is given. The indicators of total stands volume and their distribution according to the size-quality categories at a certain rotation age are determined. The area was calculated and an economic assessment of stand volumes of the Scots pine and Pedunculate oak forests for the design and operational rotation ages for the period of 2010‑2040 was made, on the example of the forest enterprises of Chernihiv and Kharkiv Regional Departments of Forestry and Hunting. According to the economic evaluation indicators, the existing and design rotation ages of the pine and oak stands were compared. There is a temporary decrease in the area and cost of stocks in exploited forests of pine and oak stands (Chernihiv Region). However, over time, from 2030-2040 the situation is stabilizing with the tendency to increase these indicators. In the protective, recreational and nature protection forests (Kharkiv Region) the cost indicators of stocks of pine and oak forests are constantly increasing. The expediency of application of project exploitability ages for the main tree species by forest categories in different natural zones (Polissya, Forest-steppe and Steppe) has been proved.Розглянуто основні недоліки діючих у країні віків стиглості деревостанів лісових порід за лісівничими та економічними критеріями. Проведено порівняння діючих та проектних віків стиглості деревостанів основних лісотвірних порід за природними зонами та категоріями лісів. Для встановлення віків стиглості деревостанів та відповідно віків головних рубок необхідне комплексне використання кількісних і вартісних (грошових) показників. Наведено методику економічної оцінки запасів деревостанів за віками стиглості. Визначено показники загальних запасів деревостанів та їх розподілу за розмірно-якісними категоріями деревини в конкретному віці стиглості. Розраховано площі та проведено грошову оцінку запасів деревини сосни звичайної і дуба звичайного за проектними та діючими віками стиглості на період 2010-2040 рр. на прикладі лісогосподарських підприємств Чернігівського та Харківського ОУЛМГ. Здійснено порівняння вартісних показників запасів деревостанів сосни та дуба у віці стиглості. Встановлено, що підвищення віків стиглості та віків рубок призводить до тимчасового зменшення площі стиглих деревостанів та вартості запасів деревини. Проте з часом спостерігається їх збільшення. Доведено доцільність застосування проектних віків стиглості для зазначених головних деревних порід за категоріями лісів і природними зонами (Полісся, Лісостеп та Степ) в розглянутих регіонах

Comparative analysis of different methods of retraction of the left lobe of the liver during laparoscopic sleeve gastrectomy

The global obesity epidemic has led to the increasing popularity of bariatric surgeries. Laparoscopic sleeve gastrectomy is currently the most popular bariatric procedure for obesity. Retracting of the left liver lobe during laparoscopic sleeve gastrectomy is important for achieving an optimal surgical field. Aim. The aim of our study was to evaluate the results of using different methods of retraction of the left liver lobe during laparoscopic sleeve gastrectomy in patients with morbid obesity. Materials and methods. The 86 patients who underwent laparoscopic sleeve gastrectomy were divided into three groups based on the liver retraction method used: group 1 (ENDO RETRACT™ II), group 2 (Nathanson) and group 3 (Clickline Surgical Sponge Holder). All groups were evaluated in terms of demographic characteristics; liver function tests just before surgery and on the 1st and 2nd postoperative day (POD); developing complications and length of hospital stay. Results. The groups did not differ significantly in terms of demographic characteristics (p > 0.05). The Nathanson liver retractor (group 2) caused a significant rise in ALT and AST at POD 1 and POD 2 compared with group 1 and 3 (p < 0.05). The ENDO RETRACT™ II liver retractor (group 1) caused a higher incidence of liver injury than other groups. It led to statistical significance prolonged total operation time (p = 0.003), increased blood loss (p = 0.002) and prolonged postoperative hospital stay (p = 0.001) compared with other groups. Conclusions. The technique of left lobe retraction during laparoscopic sleeve gastrectomy using Clickline Sur- gical Sponge Holder is safe and effective. The use of this technique causes significantly less measurable liver damage and does not lead to an increase in the level of liver enzymes

Peculiarities of structure and phase composition of V-Ti-Cr alloy obtained by sintering technique

Abstract Alloy of the V-Ti-Cr system is a promising material exploited under high radiation and in corrosion environment. We sintered V-4.9Ti-4.8Cr alloy from particles with original average size of 30, 280 and 200 μm, respectively for vanadium, titanium and chromium powders, by pressing of the powder mixture and its further sintering. The studies were undertaken using the methods of X-ray structural analysis, scanning electron microscopy with an energy dispersive analyzer and transmission electron microscopy. It was established that the structure of the alloy represented matrix grains (BCC solid solution), along the boundaries and at junctions of which the groups of oxycarbonitride particles of V, Ti, Cr (C,N,O) type of the variable elemental composition were arranged. The particles possessed a plate-like (0.4 x 2.0 μm) and rounded (0.5 μm) shape. The solid solution of the alloy was heterogeneous by concentration. This was evidenced by the complications of the diffraction patterns obtained from the corresponding sections of the structure. These were cords of main reflexes, satellites and emergence of a moire banded contrast in separate sections of the sample. Inside the matrix grains, there were nanoparticles (15 μm) of carbide V55Cr25C20, being a source of elastic internal local stresses

QCD in the nuclear medium and effects due to Cherenkov gluons

The equations of in-medium gluodynamics are proposed. Their classical lowest order solution is explicitly shown for a color charge moving with constant speed. For nuclear permittivity larger than 1 it describes emission of Cherenkov gluons resembling results of classical electrodynamics. The values of the real and imaginary parts of the nuclear permittivity are obtained from the fits to experimental data on the double-humped structure around the away-side jet obtained at RHIC. The dispersion of the nuclear permittivity is predicted by comparing the RHIC, SPS and cosmic ray data. This is important for LHC experiments. Cherenkov gluons may be responsible for the asymmetry of dilepton mass spectra near rho-meson, observed in the SPS experiment with excess in the low-mass wing of the resonance. This feature is predicted to be common for all resonances. The "color rainbow" quantum effect might appear according to higher order terms of in-medium QCD if the nuclear permittivity depends on color.Comment: 29 p., 4 figs; for "Phys. Atom. Nucl." volume dedicated to 80th birthday of L.B. Okun; minor corrections on pp. 11 and 13 in v

Intrinsic Spin Lifetime of Conduction Electrons in Germanium

We investigate the intrinsic spin relaxation of conduction electrons in germanium due to electron-phonon scattering. We derive intravalley and intervalley spin-flip matrix elements for a general spin orientation and quantify the resulting anisotropy in spin relaxation. The form of the intravalley spin-flip matrix element is derived from the eigenstates of a compact spin-dependent $\mathbf{k}$$\cdot$$\mathbf{p}$ Hamiltonian in the vicinity of the $L$ point (where thermal electrons are populated in Ge). Spin lifetimes from analytical integrations of the intravalley and intervalley matrix elements show excellent agreement with independent results from elaborate numerical methods.Comment: 13 pages, 2 figure

Diabetes mellitus type 1 and coronary artery disease with severe systolic heart failure in 25 year-old adult

Diabetes mellitus (DM) type 1 accounts for up to 90% of all cases of diabetes among children, adolescents and young adults (10 % are represented by T2DM, MODY, etc.). DM is characterized not only by glucose metabolism disorder, but also by abnormal protein and lipid metabolism, leading to severe macrovascular complications. A clinical case of diabetes type 1, hyperlipidemia, coronary artery disease (CAD) and chronic heart failure (HF) in a 25-year-old adult has been demonstrated. The medical examination revealed lipid metabolism disorders, multivessel coronary artery disease, which required myocardial revascularization, and severe heart failure with a reduced ejection fraction (HFrEF). The clinical case demonstrates that proper cardiovascular examination should be performed in all patients with diabetes and lipid disorders, regardless of age and type of diabetes. The authors also consider the use of sodium-glucos