Atmospheric Pressure Conditions Research Articles

Inflammation-attenuating effect of carbon dioxide versus room-air environment in a rat laparotomy model.

The mechanism by which laparoscopic operations induce lower post-operative inflammatory response compared to open surgery was investigated with regard to the effect of the type of gas environment. Rats were subjected to midline laparotomy at either CO2 (group CO2) or room-air environment (group Air) or to anesthesia only (group Control) under atmospheric pressure conditions. At various timepoints after surgery (1, 3, 6, 24, or 48h), the expression of inflammation biomarkers interleukin-6 (IL-6), tumor necrosis factor-α (TNFα), and nuclear factor-κΒ (NFκΒ) were assessed immunohistochemically in tissue samples excised from the liver, intestine, and kidneys, accompanied by histopathologic analysis, and their levels were measured by ELISA in blood samples. Tissue expression of IL-6, TNFα, and NFκΒ was downregulated in the liver and intestine in group CO2 compared to group Air and in the kidneys in group Air compared to group CO2. However, no differences were noted among groups regarding the histopathologic score of organ tissues and the blood serum levels of inflammation biomarkers. Post-operative local inflammatory response was lower in intra-peritoneal organs of rats subjected to laparotomy at CO2 rather than room-air environment under atmospheric pressure conditions.

Various CVD-grown ZnO nanostructures for nanodevices and interdisciplinary applications

This work presents a simple chemical vapour deposition (CVD) method to grow ZnO nanostructures. By annealing Zn powder under atmospheric pressure conditions, we collected nanocrystals with various morphologies, including rods, pencils, sheets, combs, tetrapods, and multilegs. Raman scattering study reveals that the samples are monophasic with a hexagonal structure, and fall into the P63mc space group. Depending on the morphology and crystal quality, their photoluminescence spectra have only a strong UV emission associated with the exciton radiative recombination, or both UV and defect-related visible emissions with their relative intensity ratio varying with the excitation power density. The obtained results prove that ZnO exhibits many novel nanostructures that can foster the development of next-generation optoelectronic nanodevices and new applications in biological and biomedical fields.

Solvent‐free synthesis of medium chain triacylglycerols by esterification of capric, caprylic acids with 1, 3‐specific and non‐specific lipases

AbstractMedium chain triacylglycerols (MCTs) are used as a functional oil in various food and pharmaceutical formulations because of their numerous health benefits and physical properties. Enzymatic esterification of glycerol with caprylic (C8:0) and capric acids (C10:0) in a molar ratio of 1:3.5 [50% (C8:0) and 50% (C10:0)] was carried out for the solvent free synthesis of MCTs using 5% (w/w) 1,3 specific lipase, Lipozyme RM IM and non‐specific lipase, Novozym 435 in the presence of molecular sieves (10%) and low pressure conditions (50 and 150 mbar) at 50°C. Novozym 435 was more effective in the esterification reaction under 50 mbar reduced pressure, achieving ~54.74% triacylglycerol formation in 6 h, compared to Lipozyme RMIM, which achieved ~31.25% under the same conditions. Further reactions with Novozym 435 for 24 h showed that the maximum formation of MCTs occurred at 20 h (86.46 ± 3%), after which the reaction reached equilibrium. When 50 mbar was used, the formation of triacylglycerols enhanced 13 times compared with the results obtained at atmospheric pressure condition. Chemical characterization of the final MCTs confirmed the formation of four triacylglycerol species (TAG (8:0/8:0/8:0), TAG (8:0/8:0/10:0), TAG (8:0/10:0/10:0), and TAG (10:0/10:0/10:0) with LC–MS and NMR analysis. The melting and crystallization points of the synthesized oil was found to be −3.47°C and −23.48°C, respectively. Our findings contribute to developing a green process for synthesizing MCTs using two different fatty acids. The final product can be used as a nutraceutical oil or as an ingredient to enhance the food's physical properties.

A semiconducting supramolecular Co(II)-metallogel based resistive random access memory (RRAM) design with good endurance capabilities.

A highly efficient approach for synthesizing a supramolecular metallogel of Co(II) ions, denoted as CoA-TA, has been established under room temperature and atmospheric pressure conditions. This method employs the metal-coordinating organic ligand benzene-1,3,5-tricarboxylic acid as a low molecular weight gelator (LMWG) in DMF solvent. A comprehensive analysis of the mechanical properties of the resulting supramolecular Co(II)-metallogel was conducted through rheological investigation, considering angular frequency and thixotropic study. The hierarchical rocky network structure of the supramolecular Co(II)-metallogel was unveiled using field emission scanning electron microscopy (FESEM). Transmission electron microscopic (TEM) analysis showed rod-shaped structures via low-magnification high angle annular dark field (HAADF) bright field scanning transmission electron microscopic (STEM) imaging, while energy dispersive X-ray (EDX) elemental mapping confirmed its primary chemical constituents. The formation mechanism of the metallogel was examined via fourier transform infrared spectroscopy (FTIR) spectroscopy. The nature of the synthesized CoA-TA metallogel was affirmed through powder X-ray diffraction (PXRD) analysis. Furthermore, this study involved fabrication of Schottky diode structures in a metal-semiconductor-metal geometry based on cobalt(II) metallogel (CoA-TA), enabling observation of charge transport behavior. Remarkably, a resistive random access memory (RRAM) device utilizing cobalt(II) metallohydrogel (CoA-TA) demonstrated bipolar resistive switching at room temperature and under ambient conditions. The switching mechanism was investigated, revealing the formation and rupture of conductive filaments between metal electrodes that govern the resistive switching behavior. This RRAM device exhibited an impressive ON/OFF ratio (~ 414) and exceptional endurance over 5000 switching cycles. These structures offer great potential for diverse applications such as non-volatile memory design, neuromorphic computing, flexible electronics and optoelectronics. Their advantages lie in their fabrication process, reliable resistive switching behavior and overall performance stability.

Study on combustion characteristics of ammonium perchlorate enhanced hydroxylamine nitrate-based electronically controlled solid propellant

Electrically controlled solid propellants (ECSPs) have attracted significant attention as a novel class of solid propellants owing to their unique electrochemical properties. In this study, a series of ECSP formulations composed of hydroxylammonium nitrate (HAN), ammonium perchlorate (AP), and polyvinyl alcohol (PVA) were prepared and experimentally investigated to understand the effect of applied voltage on their combustion characteristics, and their combustion behavior was systematically characterized. The results demonstrated that the addition of AP decreased the initial conductivity of the ECSP; however, the average combustion rate during steady-state burning increased significantly, along with a corresponding increase in the combustion temperature. This effect became more pronounced with increasing AP concentration. The dissolved AP in the system acts as an efficient charge carrier, whereas the undissolved AP enhances the combustion performance by producing oxygen through thermal decomposition. Furthermore, even under atmospheric pressure conditions, the combustion of the ECSP can be effectively controlled by adjusting the applied voltage, with combustion ceasing upon removal of the voltage. The mechanism by which AP enhances combustion was analyzed, providing new insights for the optimization of ECSP formulations.

Wave mode observation of hydrogen/oxygen driven rotating detonations in the hollow and annular rotating detonation rocket engine

The rotating detonation rocket engine (RDRE) fueled by hydrogen/oxygen propellant represents a promising propulsion technology due to its high thermodynamic efficiency and propellant superior specific impulse. The rotating detonation wave (RDW) must propagate in a specific propagation mode while maintaining the self-sustaining state to ensure stable operation. An experimental system of hydrogen/oxygen fueled RDRE was developed in the present study. The operation of RDRE and propagation mode of RDW were investigated under atmospheric pressure conditions, and both hollow and annular combustors were tested. The high-frequency pressure fluctuations in the RDRE were measured by the dynamic pressure transducer, while a high-speed camera was used to capture images of flame luminescence at the rear end of the RDRE. The experimental results showed that the RDW could be initiated and reached a self-sustaining propagation state with hydrogen/oxygen propellant in the hollow and annular RDRE. A single-wave mode, a two-wave co-rotating mode, and a three-wave co-rotating mode were visualized under different conditions. With the increase in the equivalence ratio, the number of rotating detonation fronts decreased, and the variations in the RDW propagation modes were consistent in the hollow and annular RDRE. However, when the equivalence ratio exceeds 1.2, the propagation velocity decreases sharply in the annular combustor, while in the hollow combustor the RDW propagates stably, revealing a higher upper limit for the equivalence ratio. Also, the dominant frequency distribution was more concentrated in the hollow combustor. The findings provide valuable insight into the variations in detonation modes related to the equivalence ratio and combustor configuration.

DFT investigation of thermodynamic, electronic, optical, and mechanical properties of XLiH3 (X= Mg, Ca, Sr, and Ba) hydrides for hydrogen storage and energy harvesting

The present study investigates the hydrogen storage capacity and physical properties of the perovskite hydrides XLiH3 (X = Mg, Ca, Sr, and Ba). The studied compounds MgLiH3, CaLiH3, SrLiH3, and BaLiH3 have lattice constants 3.76, 4.29, 4.64, and 5.04 Å, respectively. These compounds are also observed to be stable in cubic phase under atmospheric pressure and temperature conditions. They have hydrogen storage capacities 8.76 wt%, 5.99 wt%, 3.07 wt%, and 2.03 %, respectively. The SrLiH3 compound has the greatest Debye temperature (θD) of 344.41 K. The analysis of the electronic band structure and density of states reveals that perovskite hydrides have semiconducting characteristics with indirect band gap values of 2.66, 2.34, 1.94, and 1.37 eV, respectively. The materials are semiconductors and have suitable band gaps to be utilized in optical devices. Therefore, the optoelectronic properties of dielectric constants, absorption, and energy loss have been determined to predict the potential of materials for optoelectronic applications. Furthermore, the elastic constants, moduli, and anisotropy are also calculated for the observed materials. The Possion and Pugh ratios indicate these compounds exhibit ductile behaviour and significant anisotropy. Therefore, large values of hydrogen capacities, stabilities, and extraordinary physical behaviour make them important for hydrogen storage systems.

Experimental Study on the Treatment of Produced Water from Carbon Dioxide Drive by Aeration Method

Abstract To further explore the effective development of produced water treatment technologies suitable for low to ultra-low permeability oil fields, and to clarify the water quality characteristics of produced water from CO2 flooding. A study was conducted on the basic water quality characteristics of produced water from low to ultra-low permeability oil fields. Indoor CO2 gas removal experiments were conducted using the aeration method under 40°C atmospheric pressure conditions. The research results indicate that the CO2 content in the extracted water is one of the important influencing factors for the changes in characteristic parameters such as water pH, mineralization, and corrosion rate; Under the condition of 40°C atmospheric pressure test, the aeration method has a significant treatment effect on the produced water from CO2 flooding, which can effectively remove 70% of the CO2 in the water, thereby improving the pH of the water to 8, and effectively inhibiting the corrosion rate of the produced water below 0.076mm/a.

Wake vortex safety assessment during cruise using a regional medium-short -range turbofan aircraft as an example

Regional turbofan aircraft, which are used for medium-short distances, have a heightened risk of high-altitude Wake Vortices(VV) because of their tail-mounted engines and high horizontal tail configurations. For some regional medium-short-range turbofan aircraft, this threat is higher than that for conventionally designed aircraft. To analyze the flight safety of turbofan aircraft during cruise, this study developed a model to assess wake vortex encounters based on evolutionary high-altitude wake flow patterns. First, the high-altitude wake vortex aircraft dissipation patterns were analyzed by combining Quick Access Recorder (QAR) flight data with the wake vortex evolution model. Then, to consider the uniqueness of the medium-short-range turbofan aircraft, the severity of the wake vortex encounters was simulated using an induced roll moment coefficient. The proposed high-altitude wake vortex encounter model was able to identify and assess the high-altitude wake vortex changes, the bearing moments at different altitudes, and the atmospheric pressure conditions. Using the latest wake separation standards from the International Civil Aviation Organization(ICAO), acceptable safety wake intervals for follower aircraft in different scenarios were determined for the safety assessment. The results indicate that compared to mid and low altitudes, the high-altitude aircraft wake vortex dissipation rate is faster, the ultimate bearing moment is weaker, and the roll moment coefficient is higher, which confirm that there is elevated wake vortex encounter severity for regional turbofan aircraft. As safety is found to deteriorate when encountering wake vortices at altitudes higher than 8 km, new medium-short-range turbofan regional aircraft require higher safety margins than the latest wake separation standards.

Diffusive solubility of nitrogen in Propane: Measurement from 96 K to 227 K at 0.1 MPa

The burgeoning demand for large-scale energy storage has catalyzed the advancement of Liquid Air Energy Storage (LAES) technology. However, the liquid-phase propane cold storage process in LAES systems encounters a significant challenge: the dissolution of nitrogen protection gas in propane poses a substantial risk to both operational safety and performance. Given the dearth of data on the diffusive solubility of nitrogen in propane under constant atmospheric pressure and low-temperature conditions, this study constructed a testbench and conducted experiments within a temperature range of 96–227 K at a pressure of 0.1 MPa. The molar diffusive solubilities at 227 K, 176 K, 139 K, and 96 K are 0.030 %, 0.177 %, 0.297 %, and 0.962 %, respectively. Besides, this study also fits a calculation equation for the diffusive solubility of nitrogen in propane, which applies to the propane cold storage process in LAES systems.

Analysis of unstable combustion caused by the Gas–Liquid two-phase flow in small hypergolic propellant engines

Hypergolic bipropellant engines are extensively used in spacecraft operations. In these engines, the combustion reaction is initiated by the impinging jets of the oxidizer and fuel in the liquid phase. The most commonly used hypergolic fuels, hydrazine and monomethylhydrazine, as well as the oxidizer, nitrogen tetroxide, are all in liquid state under room temperature and atmospheric pressure conditions. However, as these engines are operated in a space vacuum, a portion of the propellant inevitably evaporates because of low-pressure boiling immediately after engine start-up. The mixing of gas with liquid propellant results in unstable combustion, and minimizing this effect is critical for the engine design. Particularly, preventing high-frequency combustion instability is essential as it can be detrimental to the engine. This paper presents a mechanism that activates high-frequency combustion instability, realized by analyzing the pressure within the combustion chamber during artificially induced unstable combustion. Furthermore, the methodology for establishing operational constraints based on the proposed mechanism is clarified, along with the method for collecting test data. The study findings provide important indicators for the design criteria of bipropellant engines, contributing to the diversification and complexity of space development programs.

Experimental study on coal oxidation and temperature rise under different air leakage modes due to atmospheric pressure changes

ABSTRACT The spontaneous combustion of residual coal in enclosed goafs may induce coupled thermodynamic disasters with severe consequences. To study the dynamic characteristics of coal oxidation and temperature increase in an enclosed goaf under varying atmospheric pressure conditions, the air leakage model was analyzed through theoretical derivation. The resistance, temperature, and CO concentration during coal oxidation under different air leakage modes were further studied using a self-built experimental system. The results indicated three air leakage modes of coal oxidation in an enclosed goaf: constant, intermittent, and reciprocating. The resistance of the three modes increased from 5 Pa to 7 Pa with time. Compared to constant air leakage, the time of resistance change was advanced by 1428 s and 1897 s under intermittent and reciprocating air leakage, respectively. Additionally, both intermittent and reciprocating air leakage promote coal oxidation and produce higher CO levels compared to constant air leakage. However, intermittent air leakage is more likely to produce higher temperature points, while reciprocating air leakage is more likely to cause large areas of coal oxidation. The order of the promoting effect of the intermittent and reciprocating half cycle on coal oxidation is 60 s, 300 s, 600 s, and 1200 s. These results are significant for understanding coal spontaneous combustion and efficiently managing enclosed goafs.

CFD Analyses of Density Gradients under Conditions of Supersonic Flow at Low Pressures.

This paper deals with CFD analyses of the difference in the nature of the shock waves in supersonic flow under atmospheric pressure and pressure conditions at the boundary of continuum mechanics for electron microscopy. The first part describes the verification of the CFD analyses in combination with the experimental chamber results and the initial analyses using optical methods at low pressures on the boundary of continuum mechanics that were performed. The second part describes the analyses on an underexpanded nozzle performed to analyze the characteristics of normal shock waves in a pressure range from atmospheric pressure to pressures at the boundary of continuum mechanics. The results obtained by CFD modeling are prepared as a basis for the design of the planned experimental sensing of density gradients using optical methods, and for validation, the expected pressure and temperature courses from selected locations suitable for the placement of temperature and pressure sensors are prepared from the CFD analyses.

Experimental study on effect of pressure on ADS-4 liquid entrainment characteristics in T-junction

Liquid entrainment phenomenon can occur in the T-junction formed by the vertical ADS-4 pipeline and the hot pipe section during SBLOCA process in AP1000 reactor. At present, most of the studies on the liquid entrainment phenomenon in T-junction with large branch pipe concentrate on the atmospheric pressure condition, which is difficult to accurately reflect the real state of the accident process. The liquid entrainment experiments were carried out at 0.1–0.4 MPa on ADETEL facility. The results show that there will be obvious reverse flow phenomenon in the branch at 0.1 MPa and the phenomenon disappears gradually with the increase of pressure. Furthermore, the occurrence of intermittent two-phase slug flow in the horizontal tube was observed at lower pressures. As pressure increases, the entrainment process will become more continuous and stable, with a concomitant reduction in intermittency. The steady-state entrainment liquid level and the onset of entrainment liquid level both decrease with increasing pressure, indicating that increasing pressure can facilitate the liquid entrainment amount. The existing correlations cannot accurately estimate the entrainment amount during SBLOCA in nuclear reactor with a deviation of more than +100% between the predictions and experimental data.

Studies of dynamic spatio-temporal processes of electrons in a 50 kHz/5 MHz dual-frequency dielectric barrier discharge plasma at atmospheric pressure

Dual-frequency excitation of dielectric barrier discharge (DBD) plasma reactors, where the plasma is generated by a low-frequency (LF) source and modulated by a radio-frequency (RF) source, have been widely adopted in the low-pressure regime. However, the impacts of the RF voltage and LF voltage amplitudes on the plasma parameters, including the spatiotemporal distributions of ion and electron densities, electron dynamics, and gas temperatures, remain poorly understood in the atmospheric pressure regime. The present work addresses this issue by conducting joint experimental and simulation studies for an atmospheric-pressure 50 kHz/5 MHz dual-frequency driven DBD plasma reactor based on phase-resolved optical emission spectra and a drift–diffusion model. The results demonstrate that the dynamic spatiotemporal behaviors of electrons change dramatically as the voltage of the RF component increases from 50 V to 300 V with the voltage of the LF component fixed at 1 kV. Moreover, the RF component is further demonstrated to modulate other plasma characteristics, such as particle densities, gas temperature, and argon emissions. These results contribute toward the tailoring of the non-equilibrium and nonlinear plasma parameters obtained under atmospheric pressure conditions.

The Enhancement Origin of Antioxidant Property of Carboxylated Lignin Isolated from Herbaceous Biomass Using the Maleic Acid Hydrotropic Fractionation.

Lignin is endowed with antioxidant activity due to its diverse chemical structure. It is necessary to explore the relationship between antioxidant activity and the chemical structure of the lignin to develop its high-value utilization. Herein, we employed maleic acid (MA) as a hydrotropic agent to preferably isolate the lignin from distinct herbaceous sources (wheat straw and switchgrass) under atmospheric pressure conditions. The resultant acid hydrotropic lignin (AHL) isolated from wheat straw exhibited high radical scavenging rates, up to 98% toward DPPH and 94% toward ABTS. Further investigations indicated that during the MA hydrotropic fractionation (MAHF) process, lignin was carboxylated by MA at γ-OH of the side-chain, providing additional antioxidant activity from the carboxy group. It was also found that the radical scavenging rate of AHL has a positive correlation with carboxyl, phenolic hydroxyl contents, and the S-G (syringyl-guaiacyl) ratio, which could be realized by increasing the MAHF severity. Overall, this work underlies the enhancement origin of the antioxidant property of lignin, which will facilitate its application in biological fields as an efficient, cheap, and renewable antioxidant additive.

Identification of the Problem in Controlling the Air–Fuel Mixture Ratio (Lambda Coefficient λ) in Small Spark-Ignition Engines for Positive Pressure Ventilators

The air–fuel ratio is a crucial parameter in internal combustion engines that affects optimal engine performance, emissions, fuel efficiency, engine durability, power, and efficiency. Positive pressure ventilators (PPVs) create specific operating conditions for drive units, characterized by a reduced ambient pressure compared to standard atmospheric pressure, which is used to control carburetor-based fuel supply systems. The impact of these conditions was investigated for four commonly used PPVs (with internal combustion engines) in fire services across the European Union (EU), using a lambda (λ), carbon dioxide (CO2), carbon monoxide (CO), and hydrogen carbon (HC) analyser for exhaust gases. All four ventilators were found to operate with lean and very lean mixtures, with their lambda coefficients ranging from 1.6 to 2.2. The conducted tests of the CO2, CO, and HC concentrations in the exhaust gases of all four fans show dependencies consistent with theoretical analyses of the impact of the fuel–air mixture on emissions. It can be observed that as the amount of burned air decreases, the values of CO and HC decrease, while the concentration of CO2 increases with the increase in engine load. Such an operation can accelerate engine wear, increase the emission of harmful exhaust gases, and reduce the effective performance of the device. This condition is attributed to an inadequate design process, where drive units are typically designed to operate within atmospheric pressure conditions, as is common for these engines. However, when operating with a PPV, the fan’s rotor induces significant air movement, leading to a reduction in ambient pressure on the intake side where the engine is located, thereby disrupting its proper operation.

Architecture of bimodal porous CuO/Al2O3-controlled continuous and low-temperature production of biomass-derived γ-butyrolactone

Biomedical activities of gamma butyrolactone (GBL) play an important role in the development of novel physiological and therapeutic agents. Maleic anhydride catalytic liquid phase hydrogenation allows for selective synthesis of GBL. However, this process is hampered by high cost noble metals and high reaction pressure conditions. Here, we demonstrate cyclic dehydrogenation of biomass-derived 1,4-butanediol (1,4-BDO) under atmospheric pressure and low-temperature conditions using highly dispersed and chemically stabilized Cu species on bimodal porous Al2O3. The bimodal porous Al2O3 exhibited both Lewis and Brønsted acidic properties along with high specific surface area and large pore volume. Among prepared catalysts, 15 wt% Cu/Al2O3 catalyst has shown an optimal crystallite size, bimodal porous nature, and high diffusion properties. Hence, high catalytic activity and remarkable GBL yields with very high 1,4-BDO conversion for 50 h of continuous time-on-stream. The unique bimodal textural properties help to enhance the dehydrogenation activity with a high turnover frequency (TOF) of about 5.0118 x 10-3 s-1via efficient chemical interaction between metallic Cu and 1,4-BDO molecules.

Hydrophobic deep eutectic solvents as novel media for the recycling of waste photovoltaic modules

Disposing of end-of-life photovoltaic (PV) modules has posed a significant environmental challenge due to the absence of proficient and sustainable recycling technologies. Separating PV modules, which are ethylene–vinyl acetate (EVA)-bonded layers, including glass, solar cells (i.e., silicon wafers), and backsheets, establishes a foundation for effectively reclaiming valuable resources from PV modules. Removing EVA encapsulation is critical for disassembling PV modules; nonetheless, effective and feasible technology is currently limited. Conventional EVA dissolving agents (e.g., benzene and trichloroethylene) are highly toxic and effective only for non-cross-linked segments of EVA. Thus, developing efficient and environmentally benign reagents for PV waste recycling is urgently needed. Herein, a novel recycling route employing deep eutectic solvents (DESs) with switchable hydrophilicity has achieved successful separation of the component layers within PV modules. Complete separation of the glass and backsheet bonded by the EVA film was achieved under atmospheric pressure and moderate temperature conditions (80 °C for 2 h) by hydrophobic DESs composed of menthol and decanoic acid ([Men][DecA] (1:1)). [Men][DecA] effectively induced EVA swelling, concurrently accelerating EVA dissolution by substituting the acetate groups in the side chains of EVA with the hydroxyl groups of the DES. The superior PV module disintegration can be attributed to the exceptional EVA dissolution ability of the [Men][DecA] framework, and the achieved high solid–liquid ratio (40 g/L) for EVA in [Men][DecA] is beneficial for industrial processes. Furthermore, the reusability of [Men][DecA], which is endorsed by its switchable hydrophilicity, introduces a sustainable platform for PV module disintegration, thereby facilitating the large-scale recycling of PV waste.

Analysis of the thermodynamic performance of the SOFC-GT system integrated solar energy based on reverse Brayton cycle

Efficient power generation systems are an essential way to reduce carbon emissions. To avoid the complex effects of high-pressure conditions on the solid oxide fuel cell (SOFC) and gas turbine (GT) hybrid systems, while further improving energy efficiency. A SOFC-GT hybrid system based on the reverse Brayton cycle (RBC) is proposed, in which the SOFC operates at near atmospheric pressure conditions and GT expands below atmospheric pressure. Solar energy is integrated to further enhance system performance. Rigorous assessments of the novel system and the pressurized system are conducted utilizing energy, exergy and economic analysis. The sensitivity analysis of environmental parameters on the novel system's performance is performed. The results show that the novel system generates power and efficiency better than the conventional system when the GT compression ratio is 3 and 6, respectively. The power generation and exergy efficiency of the novel system at the design point is 60.47 % and 58.57 %, respectively. The largest exergy destruction occurred in the SOFC. The lowest exergy efficient components are the parabolic dish collector (PDC) and heat exchanger 2. The novel system is more cost-effective due to the higher lifetime of the SOFC, with the levelized cost of energy (LCOE) is 0.1418 $/kWh.