Productivity of switchgrass (Panicum virgatum L.) agrophytocenoses for long-term use

Purpose. To determene the productivity of switchgrass (Panicum virgatum L.) agrophytocenoses under the long-term use. Methods. Field, statistical, calculation and comparative. Results. During long-term switchgrass cultivation, the lowest yield was obtained in the first vegetation year: 19.7 t/ha in the control treatment, 25.3 and 17.5 t/ha in the experimental treatments. The average raw biomass yield was as following: 30.3 t/ha in the control (variety ‘Cave-in-Rock’), 32.6 t/ha and 26.5 t/ha in the experimental treatments (varieties ‘Kanlow’ and ‘Morozko’, respectively). The yield of solid biofuel (17.3 t/ha) indicates the advantage of ‘Kanlow’ over the control (11.7 t/ha). The lowest yield (15.7 t/ha) was obtained from ‘Morozko’ variety. The energy yield over the treatments: 312.8 GJ/ha in the control, 397.5 and 367.2 GJ/ha in the experimental treatments, respectively. The cost of the grown production was as following: 416.03 UAH/t in the control (‘Cave-in-Rock’), 312.01 UAH/t in ‘Kanlow’, and 366.42 UAH/t in ‘Morozko’. The profitability of the control (‘Cave-in-Rock’) was 69.5%, ‘Kanlow’ – 101.4%, ‘Morozko’ – 66.8%. Economic evaluation of the productivity of switchgrass agrophytocenoses resulted in the following ranking: ‘Kanlow’, ‘Cave-in-Rock’, ‘Morozko’. When analyzing the energy equivalent of switchgrass biomass production and energy consumption, it was found that ‘Kanlow’ yielded 588.8 GJ/ha and the control – 468.3 GJ/ha, which is lower by 120.5 GJ/ha. Conclusions. The yield of switchgrass agrophytocenoses on average over the years of research (2014–2019) was 30.3 t/ha in ‘Cave-in-Rock’ (the control), 32.6 t/ha in ‘Kanlow’, and 26.5 t/ha in ‘Morozko’. The energy equivalent of the obtained yield was 468.3 GJ/ha in ‘Cave-in-Rock’ and 588.8 GJ/ha in ‘Kanlow’, which is by 120.5 GJ/ha higher than in the control.

Efficacy of Pulsatile Flow Perfusion in Adult Cardiac Surgery: Hemodynamic Energy and Vascular Reactivity

Background: The role of pulsatile (PP) versus non-pulsatile (NP) flow during a cardiopulmonary bypass (CPB) is still debated. This study’s aim was to analyze hemodynamic effects, endothelial reactivity and erythrocytes response during a CPB with PP or NP. Methods: Fifty-two patients undergoing an aortic valve replacement were prospectively randomized for surgery with either PP or NP flow. Pulsatility was evaluated in terms of energy equivalent pressure (EEP) and surplus hemodynamic energy (SHE). Systemic (SVRi) and pulmonary (PVRi) vascular resistances, endothelial markers levels and erythrocyte nitric-oxide synthase (eNOS) activity were collected at different perioperative time-points. Results: In the PP group, the resultant EEP was 7.3% higher than the mean arterial pressure (MAP), which corresponded to 5150 ± 2291 ergs/cm3 of SHE. In the NP group, the EEP and MAP were equal; no SHE was produced. The PP group showed lower SVRi during clamp-time (p = 0.06) and lower PVRi after protamine administration and during first postoperative hours (p = 0.02). Lower SVRi required a higher dosage of norepinephrine in the PP group (p = 0.02). Erythrocyte eNOS activity results were higher in the PP patients (p = 0.04). Renal function was better preserved in the PP group (p = 0.001), whereas other perioperative variables were comparable between the groups. Conclusions: A PP flow during a CPB results in significantly lower SVRi, PVRi and increased eNOS production. The clinical impact of increased perioperative vasopressor requirements in the PP group deserves further evaluation.

SYSTEM-INFORMATION APPROACH TO UNCERTAINTY OF PROCESS AND SYSTEM PARAMETERS

The subject matter of research in the article is a system-information approach to the uncertainty of the parameters of processes and systems of the technosphere as one of the scientific directions of using information theory in metrology and other scientific areas. The system-information approach is based on the definition of the term "information" of the properties of the system, its content and meaning. The solution of the basic problem in metrology, obtaining "information" of the quantitative characteristics of the true value of the properties of objects and phenomena that reveal the regularities of the environment, is a complex scientific problem. The instrument for obtaining information about the properties of the system is the measurement process. One of the directions in the development of measurement theory is the concept of uncertainty. The goal of the work is to research of non-traditional solutions to problems of technical-cybernetic systems based on the system-information approach to the uncertainty of the parameters of processes and systems. The article solves the following tasks: to analyze the assessment of the parameters of technological processes and systems based on the system-information approach; to develop system-information methods and algorithms for the effective use of discrete-probabilistic information in technical-cybernetic systems; to develop principles and approaches for using the system-information assessment of the uncertainty of the Planck units, use of system-information modeling in various scientific directions. The following methods are used: system-information approach to processes and systems, methodology of system-information modeling of the measured value; system information methodology for the assessment of the measured quantity and uncertainty. The following results were obtained: developed a system-information methodology for assessing the nominal parameter has been developed, which provides indirect control over the independent parameters associated with it; systemic and information methods for the effective use of discrete-probabilistic information in technical and cybernetic systems have been developed; a system-information methodology for calculating the energy equivalent of product performance indicators has been developed; the principle of calculating the efficiency of manufacturing a product based on the energy equivalent of Planck units is formulated. Conclusions: The solution of the set tasks on the basis of the system-information approach to the uncertainty of the parameters of processes and systems makes it possible, from the system-information point of view, to study the regularities of the stages of the life cycle of technical-cybernetic systems and conservation laws.

Attenuation of Energy-based Demand Parameters

The intensity of ground shaking and the demand on structures during earthquakes have been generally characterized using parameters such as peak ground acceleration as well as strength-based parameters such as response spectrum ordinates (e.g., spectral acceleration) that represent the maximum amplitude of shaking for structures with specified natural period and damping values. It has long been recognized that to assess the demands on structures during earthquakes, one might employ an energy-based approach (as an alternative to the more common strength-based one), especially when there is an interest in assessing damage potential of ground motions. An energy spectrum, obtained with the same level of effort required to construct a conventional response spectrum, is a convenient single-parameter description of both amplitude and duration of ground motion and can serve as a useful means by which to describe the performance of structures with different natural periods and damping ratios.In this study, attenuation models for Northwestern Turkey are developed for two parameters (defined herein) that are related to input energy and absorbed energy. The empirical models developed take advantage of the recent increase in the database on strong motion data for Northwestern Turkey. A total of 195 recordings from 17 recent seismic events are included in this database. The ground-motion prediction equations developed are for the geometric mean of the two horizontal components of the 5-percent damped energy parameters (elastic and inelastic input energy-equivalent acceleration, Ai, and absorbed energy-equivalent velocity, Aa) at various periods. Predictions of the energy-based parameters from the proposed attenuation model are compared with (strength-based) spectral acceleration levels predicted by Özbey et al [Soil Dyn. & Earthq. Eng., 24 (2004), pp. 115-125]. It is found that the energy demand parameters were generally greater with elastic Ai demands highest. In addition, the predicted energy-based parameter levels are compared with available Western U.S. attenuation model predictions for the same energy-based parameters. Western U.S. models predict similar energy demands to those with the proposed model. Finally, amplification factors for the energy-based parameters are proposed as a function of site class; these factors can be thought of as analogous to amplification factors for spectral acceleration as given in the NEHRP Seismic Provisions. The patterns related to the amplification are similar as with spectral acceleration in NEHRP (2001). A comparison of soil amplification effects for strength- and energy-based parameters is also discussed.

An Energy-Equivalent Simplified Model for Lateral Nonlinear Vibrations of Coupled Water Turbine Generator Set Shaft-Foundation System

The traditional whole finite element method (WFEM[1]) has several shortcomings, including that it has too many degrees of freedom so the execution is not efficient and is difficult to solve in nonlinear dynamic analysis. In this paper, a novel simplified modeling approach is proposed to investigate the lateral nonlinear vibration characteristics of coupled water turbine generator set shaft-foundation system (CSFS[2]). The simplified coupled model is generated in two stages. First, a more reasonable simplified model for foundation subsystem considering coupling with each other is constructed to simulate the lateral vibrations of guide bearing foundations in hydropower house. Based on the response spectra of WFEM of hydropower house and a constructed energy error objective function, the optimal equivalent parameters of the simplified foundation model are then determined by using the genetic algorithm. Second, considering actions of various nonlinear factors and the pulsating water pressure acting on turbine runner, a nonlinear dynamic differential equations of CSFS based on Lagrange equation are derived. The nonlinear dynamic responses of CSFS using the optimal equivalent model are also compared with the field test data. It is demonstrated that the method proposed to develop the equivalent model is more efficient and more convenient in capturing the nonlinear dynamic behavior of CSFS. In addition, this energy-equivalent model is more adaptable to the stochastic uncertainty and frequency band variation in hydropower station system. Some novel dynamic laws and inner mechanism of the coupled system are also revealed further based on the proposed model. Footnotes: [1] WFEM: whole finite element method[2] CSFS: coupled water turbine generator set shaft-foundation system

Modeling Cylindrical Inhomogeneity of Finite Length with Steigmann–Ogden Interface

A mathematical model employing the concept of energy-equivalent inhomogeneity is applied to analyze short cylindrical fiber composites with interfaces described by the Steigmann–Ogden material surface model. Real inhomogeneity consists of a cylindrical fiber of finite length, and its surface possessing different properties is replaced by a homogeneous, energy-equivalent cylinder. The properties of the energy-equivalent fiber, incorporating properties of the original fiber and its interface, are determined on the basis of Hill’s energy equivalence principle. Closed-form expressions for components of the stiffness tensor of equivalent fiber have been developed and, in the limit, shown to compare well with the results available in the literature for infinite fibers with the Steigmann–Ogden interface model. Dependence of those components on the radius, length of the cylindrical fiber, and surface parameters is included in these expressions. The effective stiffness tensor of the short-fiber composites with so-defined equivalent cylindrical fibers can be determined by any homogenization method developed without accounting for interface.