Article
Thermodynamics
Mohamad Assad, Yuri Tunik
Summary: This study comprehensively analyzes the detonation cycle by comparing it with the Brayton and Otto cycles under different restrictions on thermodynamic characteristics. The results show that thermal efficiency alone is not sufficient to evaluate the thermodynamic perfection of a detonation engine. The detonation cycle generally has higher thermal efficiency than the Brayton and Otto cycles, but there are exceptions depending on the specific restrictions applied.
APPLIED THERMAL ENGINEERING
(2023)
Article
Physics, Multidisciplinary
M. A. Ramirez-Moreno, G. Ares de Parga, F. Angulo-Brown
Summary: This study applies the thermodynamic restrictions imposed by the Carnot theorem on an Otto cycle operating at maximum work regime to determine the heat capacities of electron gases from different metals. The coefficients alpha and beta, obtained from a free electron gas model, are used to calculate these values. The experimental data confirms that only metals with high electronegativities provide a fermion gas that meets the thermodynamic restrictions.
PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS
(2022)
Article
Thermodynamics
Ruihua Chen, Weicong Xu, Shuai Deng, Ruikai Zhao, Siyoung Q. Choi, Li Zhao
Summary: This study proposes an electrochemical quasi-Carnot cycle (EQCC) for low-grade heat harvesting, addressing the limitations of irreversible losses in emerging continuous electrochemical heat engines. The performance of ideal EQCC is derived mathematically, and the non-ideal EQCC considering irreversible losses is realized by adjusting the current distribution in the system. The results show that the ideal EQCC achieves a Carnot efficiency with a power density of 945 W m-2 under a temperature difference of 18°C, while the optimized non-ideal EQCC reaches a relative efficiency of 55.2% with a maximum power density of 12.6 W m-2.
Article
Thermodynamics
Feng Zhang, Gaoliang Liao, E. Jiaqiang, Jingwei Chen, Erwei Leng
Summary: This study investigates the performance improvement of the recompression supercritical carbon dioxide (sCO(2)) power cycle by integrating with two novel absorption power cycles (APC). Comparative study and optimization analysis show that all APC subsystems can enhance the stand-alone sCO(2) system performance and the proposed sCO(2)/APC systems further improve the overall performance of the original sCO(2)/APC system.
ENERGY CONVERSION AND MANAGEMENT
(2021)
Article
Multidisciplinary Sciences
Sabrina Marecos, Rae Brigham, Anastacia Dressel, Larissa Gaul, Linda Li, Krishnathreya Satish, Indira Tjokorda, Jian Zheng, Alexa M. Schmitz, Buz Barstow
Summary: By the end of the century, a large amount of CO2 needs to be removed annually to maintain global temperatures. Natural weathering of ultramafic rocks can convert CO2 into stable carbonates, but it takes thousands of years. Using biodegradable lixiviants from cellulosic biomass can accelerate CO2 mineralization, but it may deplete the world's biomass supply. Electromicrobial production technologies (EMP) that combine renewable electricity and microbial metabolism can produce affordable lixiviants and sequester CO2. This study highlights the potential and need for extensive R&D in this approach.
Article
Thermodynamics
Shuangjun Li, Shuai Deng, Li Zhao, Ruikai Zhao, Xiangzhou Yuan
Summary: By describing and analyzing the thermodynamic carbon pump (TCP) cycle, a better understanding of energy conversion efficiency can be achieved, helping to apply thermodynamics more effectively in the technical field and improve the development of CO2 capture technology.
Article
Thermodynamics
Enhui Sun, Yueqi Sun, Shujing Feng, Lei Zhang, Jinliang Xu, Zheng Miao
Summary: This study introduces a novel approach called the supercritical organic Rankine cycle (S-ORC) that utilizes extraction steam compression regeneration in the supercritical state to enhance the thermal efficiency of an organic Rankine cycle (ORC). The study results showed that both the S-ORC and the supercritical regeneration ORC (SR-ORC) had increased thermal efficiency and exergy efficiency.
ENERGY CONVERSION AND MANAGEMENT
(2023)
Article
Thermodynamics
Cong Wang, Xuanfei Yu, Xin Pan, Jiang Qin, Hongyan Huang
Summary: This paper presents a new optimization method based on the cascade utilization of cold source to solve the problem of engine performance degradation caused by excessive fuel consumption in the precooled engine cycle. Two new optimization cycles, ARPC and HRPC, are proposed and evaluated using a unified model. The results show that the fuel consumption of the HRPC could be reduced compared with the traditional precooled engine, and the specific impulse is higher, contributing to performance optimization.
Article
Energy & Fuels
Xiaolong Han, Jianbo Li, Xiangqiang Kong, Tao Sun, Chen Zhang, Li Yin
Summary: The novel cascade refrigeration system proposed in this study utilizes waste heat and the excellent performance of CO2 subcritical cycle to provide low-temperature cooling capacity for fishing boats and refrigerated trucks at a low energy cost. The system's coefficient of performance is significantly higher than traditional systems, and it can effectively utilize waste heat and decrease power consumption.
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
(2021)
Article
Thermodynamics
Dongpeng Zhao, Shuai Deng, Ruikai Zhao, Li Zhao, Weicong Xu, Xiting Long
Summary: The flexible programming of thermodynamic cycles (FPTC) is a novel method developed based on graphical analysis in the T-s diagram, which enables the analysis and calculation of complex cycles by performing logical operations on simple cycles. Case studies showed that FPTC is an efficient approach to analyze complex cycles and provides a new perspective for constructing or designing complex thermodynamic cycles.
ENERGY CONVERSION AND MANAGEMENT
(2021)
Article
Thermodynamics
Xuefeng Zhang, Liwei Wang, Zixuan Wang, Lemin Wang, Zihan Zhang
Summary: A pilot-scale organic Rankine cycle (ORC) power generation system with a thermally-driven pump was constructed and investigated. The system showed stable fluctuation in electrical power output with maximum time-averaged power of 11.61 kW at a heat source temperature of 130.00 degrees C. The system also achieved maximum thermal efficiency of 4.3% and exergetic efficiency of 20.9% at heat source temperatures of 130.00 degrees C and 100.00 degrees C, respectively. The system's performance was compared with a conventional ORC system, and the thermally-driven ORC system performed better at heat source temperatures below 110.00 degrees C.
Article
Biochemistry & Molecular Biology
Hana El-Samad
Summary: Cells utilize feedback control mechanisms to regulate growth, division, repair, and responses to environmental changes, maintaining homeostasis of tissues and organs. Understanding the properties and challenges of biological feedback control networks is key to unraveling the essence of life.
Article
Biophysics
Jeremy A. Owen, Pranay Talla, John W. Biddle, Jeremy Gunawardena
Summary: Switch-like motifs, particularly ultrasensitive switches, which consist of two enzymes acting antagonistically on a substrate by making or removing a covalent modification, play important roles in biochemical networks. In this study, the linear framework for timescale separation was used to establish strict bounds on the performance of any covalent-modification switch in terms of the chemical potential difference driving the cycle. These bounds apply to different enzyme mechanisms and rate constants, providing fundamental physical constraints on covalent switching.
BIOPHYSICAL JOURNAL
(2023)
Article
Thermodynamics
Muhammad Ahmed, Abubakr Ayub, Nadeem Ahmed Sheikh, Muhammad Wakil Shahzad, Muhammad Haroon, Muhammad Imran
Summary: This paper focuses on the optimization of supercritical CO2 recompression and partial cooling cycles under various conditions. The study investigates the effects of heat sink temperature, mass split fraction, and cycle minimum pressure on the thermal efficiency of the power cycles. Response surface method and ANOVA approach are used to develop mathematical models and analyze the most influential parameters. The results reveal that the heat sink temperature has the greatest impact on thermal efficiency in the recompression cycle, while the minimum pressure plays the most significant role in the partial cooling cycle.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2023)
Article
Biochemical Research Methods
Seung Won Shin, Changyoon Baek, Junhong Min
Summary: Genotyping of single nucleotide variants (SNVs) has improved disease-related risk assessment and diagnosis. However, the high sequence similarity between wild-type (WT) and SNV poses challenges. To increase discrimination, a workflow based on nucleic acid thermodynamic analysis and rejection sampling for designing mismatch-introduced probes (MIPs) has been proposed.
ANALYTICAL AND BIOANALYTICAL CHEMISTRY
(2022)