Evaluation of the gas turbine unit in the Kirkuk gas power plant to analyse the energy and exergy using ChemCad simulation

The purpose of the study is to evaluate the thermal performance of the gas turbine unit represented by (K3) under actual weather conditions by applying the first and second laws of thermodynamics, the design production of the unit (283.6 MW) at standard conditions (1 bar) and temperature (15) Celsius, which included the analysis of the unit energy and available energy. Hence, to find out the weaknesses and losses in the system ChemCad simulation has been used to estimate the effects of external factors (ambient temperature, compression ratio and relative humidity) for a whole year on the performance of the turbine unit. Overall results showed that the maximum exergy efficiency was obtained in November; it was ∼37% when Ta was 19.39◦C. The maximum efficiency obtained at Ta equal to 19.39◦C, which was ∼37.67%. Higher ambient temperature increases specific fuel consumption (SFC). The results show that the SFC for the practical and program calculations increases with the increase in the temperature of the external environment and reached the maximum rate in the practical calculations in September (0.224) at 33.27◦C. Thus, it economically affects the price of power production. Moreover, the results showed that the combustion chamber occupied the first place for the destruction of available energy, and the results of energy efficiency and available energy were 39.20% and 30.83%, respectively. © The Author(s) 2022. Published by Oxford University Pres

Assessment of the performance of solar water heater: an experimental and theoretical investigation

This study aims to evaluate the performance of a flat plate solar water heater (SWH) theoretically and experimentally. The thermal performance of the SWH was predicted using Fortran 90 programming language. SWH was designed as a square shape with dimensions of 110 cm length, 120 cm width and 10 cm depth and tested by integrating with a modified solar distiller to increase the water temperature in the basin at a constant mass flow rate of 1.2 l/min. The tests were conducted under the weather condition of Yekaterinburg city, Russia, from June to September of 2019, and a typical day was chosen for each month (19 June, 17 July, 22 August and 15 September). The study revealed that the highest efficiency of the solar water collector obtained at the highest value of the intensity of solar radiation at mid-day. The maximum thermal efficiencies achieved on 17 July of 2019 were ~67% and 66% based on theoretical and experimental analyses, respectively. A simultaneous increase in the water temperature and the intensity of solar radiation has been observed. During the four typical days of the experiment, the highest water temperatures of the solar collector were recorded during midday, i.e. $57.2{}^{\circ}\mathrm{C},64.4{}^{\circ}\mathrm{C},52.4{}^{\circ}\mathrm{C}\kern0.5em \mathrm{and}\ 49{}^{\circ}\mathrm{C}$ at the inlet, and $62.8{}^{\circ}\mathrm{C},71{}^{\circ}\mathrm{C},57.4{}^{\circ}\mathrm{C}$ and $53.2{}^{\circ}\mathrm{C}$ at the outlet for 19 June, 17 July, 22 August and 15 September 2019, respectively, while the solar radiation intensities recorded are $957,1022,840\kern0.5em \mathrm{and}\ 723\ \mathrm{W}/{\mathrm{m}}^2$ for the test days. © 2022 The Author(s) 2022. Published by Oxford University Press

A Sustainable Energy Distribution Configuration for Microgrids Integrated to the National Grid Using Back-to-Back Converters in a Renewable Power System

A desire to produce power in microgrids has grown as the demand for electricity has expanded and the cost of installing modern transmission lines over long distances has become infeasible. As such, microgrids pose DC/AC harmonic distortion losses to the voltage supply that eventually fluctuate the output voltage. The key takeaways that this study presents are: (a) a configuration for microgrids integrated to the national grid using back-to-back converters in a renewable power system is achieved; (b) different scenarios of various schemes of sustainability of the power management in microgrids are analyzed; and (c) the reliable and stable network output power distribution is achieved. In this, the proposed control configuration provides space for construction and stability of the power system with sustainability of the power management. The results show that this current configuration works and stabilizes the network in the shortest time possible, and that the DC connection voltage is regulated and maintains reliable network output despite declining slope controllers, DC power and voltage, and power electronic back-to-back converters. Overall, the simulation results show that the proposed system shows acceptable performance under different scenarios. The accuracy of the results is validated with mathematical formulation simulation using MATLAB software. This system can be utilized in distant regions where there is no power grid or in areas where, despite having a power infrastructure, renewable energies are used to supply the output load for the majority of the day and night

A sustainable energy distribution configuration for microgrids integrated to the national grid using back-to-back converters in a renewable power system

A desire to produce power in microgrids has grown as the demand for electricity has expanded and the cost of installing modern transmission lines over long distances has become infeasible. As such, microgrids pose DC/AC harmonic distortion losses to the voltage supply that eventually fluctuate the output voltage. The key takeaways that this study presents are: (a) a configuration for microgrids integrated to the national grid using back-to-back converters in a renewable power system is achieved; (b) different scenarios of various schemes of sustainability of the power management in microgrids are analyzed; and (c) the reliable and stable network output power distribution is achieved. In this, the proposed control configuration provides space for construction and stability of the power system with sustainability of the power management. The results show that this current configuration works and stabilizes the network in the shortest time possible, and that the DC connection voltage is regulated and maintains reliable network output despite declining slope controllers, DC power and voltage, and power electronic back-to-back converters. Overall, the simulation results show that the proposed system shows acceptable performance under different scenarios. The accuracy of the results is validated with mathematical formulation simulation using MATLAB software. This system can be utilized in distant regions where there is no power grid or in areas where, despite having a power infrastructure, renewable energies are used to supply the output load for the majority of the day and night

New Analogs of the Complement C3 Inhibitor Compstatin with Increased Solubility and Improved Pharmacokinetic Profile

Improper regulation of complement is associated with various pathologies, and the clinical demand for compounds that can regulate complement activation is therefore imperative. Cp40, an analog of the peptide compstatin, inhibits all complement pathways at the level of the central component C3. We have further developed Cp40, using either PEGylation at the N-terminus or insertion of charged amino acids at the C-terminus. The PEGylated analogs are highly soluble and retained their inhibitory activity, with C3b binding affinity dependent on the length of the PEG chain. The addition of two or three residues of lysine, in turn, not only improved the peptide’s solubility but also increased the binding affinity for C3b while retaining its inhibitory potency. Three of the new derivatives showed improved pharmacokinetic profiles in vivo in non-human primates. Given their compelling solubility and pharmacokinetic profiles, these new Cp40 analogs should broaden the spectrum of administration routes, likely reducing dosing frequency during chronic treatment and potentially expanding their range of clinical application

Differential responses of three grapevine cultivars to Botryosphaeria dieback

Botryosphaeria dieback is a fungal grapevine trunk disease which represents a threat for viticulture worldwide due to the decreased production of affected plants and their premature death. This dieback is characterized by a typical wood discoloration called “brown stripe”. Herein, a proteome comparison of the brown striped wood from Botryosphaeria dieback-affected standing vines cultivar 'Chardonnay', 'Gewurztraminer' and 'Mourvèdre' was performed. The transcript analysis for 15 targeted genes and the quantification of both total phenolics and specific stilbenes were also performed. Several pathogenesis-related proteins and members of the antioxidant system were more abundant in the brown striped wood of the three cultivars, whereas other defense-related proteins were less abundant. Additionally, total phenolics and some specific stilbenes were more accumulated in the brown striped wood. Strongest differences among the cultivars concerned especially proteins of the primary metabolism, which looked to be particularly impaired in the brown striped wood of 'Chardonnay'. Low abundance of some proteins involved in defense response probably contributes to make global response insufficient to avoid the symptom development. The differential susceptibility of the three grapevine cultivars could be linked to the diverse expression of various proteins involved in defense response, stress tolerance and metabolism