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The increasing penetration of variable renewable energy sources intensifies grid imbalance and challenges the reliability of small-scale power systems. This study addresses these challenges by developing and analyzing a fully integrated hybrid energy system that combines biogas upgrading to biomethane, photovoltaic (PV) generation, hydrogen production via alkaline electrolysis, hydrogen storage, and a gas-steam combined cycle (CCGT). The system is designed to supply uninterrupted electricity to a small municipality of approximately 4500 inhabitants under predominantly self-sufficient operating conditions. The methodology integrates high-resolution, full-year electricity demand and solar resource data with detailed process-based simulations performed using Aspen Plus, Aspen HYSYS, and PVGIS-SARAH3 meteorological inputs. Surplus PV electricity is converted into hydrogen and stored, while upgraded biomethane provides dispatchable backup during periods of low solar availability. The gas-steam combined cycle enables flexible and efficient electricity generation, with hydrogen blending supporting dynamic turbine operation and further reducing fossil fuel dependency. The results indicate that a 10 MW PV installation coupled with a 2.9 MW CCGT unit and a hydrogen storage capacity of 550 kg is sufficient to ensure year-round power balance. During winter months, system operation is sustained entirely by biomethane, while in high-solar periods hydrogen production and storage enhance operational flexibility. Compared to a conventional grid-based electricity supply, the proposed system enables near-complete elimination of operational CO2 emissions, achieving an annual reduction of approximately 8800 tCO2, corresponding to a reduction of about 93%. The key novelty of this work lies in the simultaneous and process-level integration of biogas, hydrogen, photovoltaic generation, energy storage, and a gas-steam combined cycle within a single operational framework, an approach that has not been comprehensively addressed in the recent literature. The findings demonstrate that such integrated hybrid systems can provide dispatchable, low-carbon electricity for small communities, offering a scalable pathway toward resilient and decentralized energy systems.

Due to the global climate strategy to reduce greenhouse gases and the energy crisis caused by global political and economic challenges, the development of renewable energy, as well as achieving energy security, has become a very urgent and priority issue for many countries of the world. As a renewable energy source hydrogen has a very high potential to consider a promising alternative fuel for the power generation, including gas turbines. Due to its high calorific value, low emissions and versatility, hydrogen has many advantages over conventional fuels. Also it is the fact that the gas turbine industry has made a strong commitment to developing gas turbines capable of operating with 100% hydrogen by 2030. And since gas turbines currently play a vital role in balancing the global energy system, expanding gas turbine fuel options to include hydrogen could increase their potential importance in both the energy transition and long-term energy strategies. In recent years, most research and studies on hydrogen-fueled gas turbines, taking into account the ecological problem, have focused on the analysis of emission reduction in exhaust gases. Also, due to the difficulties of optimizing hydrogen combustion, most research and studies have concentrated on the analyzes of flame stability in gas turbine combustion chambers․ There are still many important questions that remain open and unexplored when it comes to energy and exergy analysis of hydrogen fueled gas turbines in simple and more complex systems. In this paper, energy and exergy analizes of a hydrogen powered gas turbine in the gas-steam system was performed. The system consists of a gas turbine powered by methane blended with hydrogen at various compositions. The amount of hydrogen enrichment varies from 0 to 100% by volume. Implementation of such analyzes were done through mathematical models which had been built using Aspen HYSYS mathematical modeling program.

In this paper, various repowering methods commonly employed in practice today are discussed. A particular emphasis is put on the hot wind-box repowering method, which is examined in greater detail. This method stands out for its simpler solution and lower investment costs compared to other repowering methods. Most research and analyses on repowering, taking into account the ecological problems and the possibilities of repowering existing old steam cycle power plants, have focused on the effect of repowering on thermodynamic parameters and emission reduction․ However, there are still many important questions that remain open and unexplored when it comes to analyze the selection of the right technology of the repowering and the right gas turbine for such a combined cycle power plant. For that purpose, based on the oxygen fraction in the gas turbine exhaust gases, nine different gas turbine models were tested for a 200 MW steam cycle power plant model. Calculations were carried out using the GateCycle modelling program. As a result of investigations, a GE Energy Oil & Gas MS9001E SC (GTW 2009 ‒ with 123 MW power) gas turbine was selected as the best one for such a combina-tion, in which case the increase of total net power output by 97.69% and the improvement of efficiency by 6.67% were registered, compared to the results before repowering, while carbon dioxide emissions were decreased by 0.29% per meg-awatt electrical power generated. The conducted research underscores the importance of selecting the right gas turbine for such a gas-steam system.

Which treatment strategy for MTT would be most effective and provide the best possible prognosis in this case? * A. Surgery * B. Chemotherapy * C. Chemotherapy and radiotherapy * D. Combination chemotherapy with surgery and/or radiation therapy Advertisement CORRECT ANSWER: * D. Combination chemotherapy with surgery and/or radiation therapy Discussion Malignant peripheral nerve sheath tumor (MPNST), also known as malignant schwannoma or neurogenic sarcoma, is a rare form of soft tissue sarcoma (STS) that develops from Schwann cells or pluripotent cells of the neural crest, constituting peripheral nerve branches or sheaths of peripheral nerve fibers.1 MPNST represents approximately 5% of all STS.2 In turn, MTT is a histological subtype of MPNST, in which malignant Schwann cells coexist with malignant rhabdomyoblasts.2,3 MTT accounts for less than 10% of MPNST.4,5 MTT is a highly aggressive tumor that most often affects patients aged less than 35 years, although it is very rare in pediatric patients.6 The prognosis is poor; 5-year survival rate among children ranges between 5% and 20%.2 The disease occurs equally among males and females.7 MTT may originate in different parts of the body, affecting extremities, head, neck, or trunk. Forty-three months after diagnosis, the child was still in remission.15 However, this is the only case report available noting successful treatment without surgical resection, so the effect of this chemotherapy/radiotherapy approach remains uncertain and thus cannot be recommended for MTT treatment. [...]chemo- and radiotherapies were followed by stem cell transplantation, and the contribution of stem cell transplantation to the outcome is questionable. If complete resection of the tumor is considered feasible, patients with MTT often undergo surgery in combination with adjuvant chemotherapy and/or postoperative radiation therapy.8,10 Postoperative chemotherapy and radiation therapy to the primary site can improve the chances of survival.7,9,10 In 2020, Ailing Zhao, MD, and colleagues compared the survival rates of children treated by different modalities and demonstrated that the rates were significantly improved for children who received postoperative therapies, vs those who had surgery alone.7 However, enlarged tumors and metastatic lesions limit the efficacy of surgery followed by adjuvant therapy. According to the data available in the literature, for children who received combination treatment of surgery, chemotherapy, and radiation therapy, the overall survival (OS) is 15 months (range, 8-22 months), and the 5-year OS rate is about 30%.7 Analyzing all these data leads us to conclude that the most effective treatment option is likely to be a combination of neoadjuvant chemotherapy, including ifosfamide/doxorubicin, followed by complete resection

This paper focuses on and discusses the concept of hot windbox repowering in an existing steam cycle power plant. Usingcommercial software, for that process based on the fraction of oxygen in exhaust gases, nine different models of gas turbineswere tested in power plant model with a fossil fuel boiler. Then thermodynamic analysis of the power plant model before andafter hot windbox repowering was conducted. This work seeks to select the best fit gas turbine for hot windbox repowering fora 200 MW fossil fuel power plant and to gain a deeper understanding of the effect of hot windbox repowering. To this end ninemodels of gas turbines with different net electrical power (from 50 to 125 MW) were tested and General Electric production GEEnergy Oil&Gas MS9001E SC (GTW 2009) 123 MW gas turbine was selected as the most suitable for the model of the powerplant and, after repowering, the total power of the power plant rose to 398 MW. Calculations were performed in 2 stages:1) calculation and comparison of the thermodynamic parameters as well as carbon dioxide emissions of power plant modelbefore and after repowering with nine different gas turbines, 2) calculation of thermodynamic parameters of the combinedcycle power plant model before and after repowering in values 100%, 90%, 80%, 70%, 60% of fossil fuel boiler heat loads.

This paper is dealing with the presence of overweight and obesity in different countries and their relation to the number of McDonalds outlets in the selected countries. We are dealing with the following two research questions. What are the effects of large food manufacturers’ activities on the economy of the country, in terms of it's health factors (BMI index)? Is the emergence of a large international food manufacturer beneficial for the physical condition of the inhabitants of a country? Based on our regression results, we can say that fast-food producers in our sample do not have a significant statistical effect on the increase in the BMI index of the inhabitants of the countries. Since a significant statistical relationship between the number of outlets in the fast-food industry and the BMI index was not found, it is impossible to say unequivocally what effect the first factor has on the second.

In this paper we deal with an issue of healthy environmentally responsible attitude to nutrition. We focus on the question how large multinational companies influence this aspects of sustainable development. We provide literature overview and we outline the main assumptions to be used in the empirical research on this issue. We first describe the role of multinational companies on the food market and the current global trends on this market. Then we focus on the fast food subset of the food market and on the issues of overweight and obesity.

The mechanisms of oxygen diffusion in brain capillaries have not been fully clarified to date. According to the laws of physics, the well-documented phenomenon of hyperoxemia-induced excessive increases in brain tissue oxygen pressure (PbtO2) contradicts traditional models of cerebral capillary oxygen diffusion. Circulating models predict a significant drop in oxygen pressure (PO2), and some of them foresee the presence of hypoxic or anoxic corners near the capillary end, regardless of high PbtO2 levels. We propose that the cerebral intracapillary transformation of hemoglobin from the relaxed (R) to the tense (T) quaternary conformational state, driven by deoxygenation and an overload of negative allosteric effectors, and characterized by a lower, more hyperbolic dissociation curve, mitigates the oxygen pressure difference across cerebral capillaries, ensuring a homogeneous pericapillary distribution of oxygen. The hemoglobin R to T state transition is responsible for the high PbtO2 levels observed in viable cerebral tissue during hyperoxemia.

Efficient nonlinear wave mixing is of paramount importance for a wide range of applications. However, weak optical nonlinearities pose significant challenges for accessing nonlinear light-matter interaction in compact systems. Here, we experimentally study second harmonic generation in deeply subwavelength 3R-MoS2 metasurfaces (<\\lambda/13 thick). Our measurements, supported by theoretical analysis, reveal a complex interplay and coupling between geometric resonances, optical extinction, and strong nonlinear susceptibility dispersion near excitons. We further demonstrate >150-fold enhancement in second harmonic signal at 740 nm driven by the A exciton resonance. Additionally, our theoretical studies predict an enhancement of more than 10^6 in second harmonic generation in <100 nm thick structures exhibiting bound states in the continuum resonance. These findings provide insight into accessing and harnessing the unprecedented 3R-MoS2 nonlinearities at a subwavelength scale, paving the way for ultracompact nonlinear photonic devices.