A Model for Estimating Passenger-Car Carbon Emissions that Accounts for Uphill, Downhill and Flat Roads

Carbon emissions are the primary reason that contributes to global warming. The gradient has a significant impact on the carbon dioxide (CO2) emissions produced by trucks. The aim of the current paper is to propose a carbon emission quantification model for diesel trucks on longitudinal slope sections and investigate the influence of gradient on the carbon emissions of trucks for use in the low-carbon highway design. The law of conservation of mechanical energy, the first law of thermodynamics, and the vehicle longitudinal dynamics theory were adopted for deriving the carbon emission model of the trucks on the flat, uphill, downhill and round-trip longitudinal slope segments. Three kinds of common trucks were chosen to conduct the field test. Following the test data, the model demonstrates a high accuracy. The minimum gradient which is expected to impact carbon emissions of trucks on the round-trip longitudinal slope sections was the balance gradient as revealed. The gradient of the longitudinal slope is required to be avoided to be greater in comparison with the balance gradient for the achievement of the two-way traffic low carbon operation on a highway. The results of this study are valuable to researchers interested in low carbon road design and low carbon transportation control.

Thermodynamics is an important branch of Applied Thermal Science and Engineering in which the effects of heat and mass transfer, transformation of energy, etc. are studied. It is based on two basic laws, i.e. the first law and second law of thermodynamics. The first law of thermodynamics is one of the most fundamental laws and is of special importance for the energy conversion processes and also called as the ‘Law of Conservation of Energy’. According to this law, energy is always conserved, neither can it be produced nor it can be destroyed; however, it can be converted from one form to another. All the energy that goes into the system comes out somewhere, in some form or the other which is true for all energy conversion systems. Thus, the first law of thermodynamics can be used in the form of energy conservation equation to solve the problem of various devices like heat engines, refrigerators, airconditioners, heat pumps, and other energy conversion systems. However, it tells nothing about how much heat can be converted into useful work and also it does not place restrictions on the conversion of heat into work and vice versa. Thus, as far as the first law of thermodynamics is concerned, all the heat transferred from a heat source to a heat engine could conceivably be converted into useful work, which is not true as shown by the experiments. It is also impossible to predict from the first law of thermodynamics whether a process is physically possible or not. Until now it has been assumed that energy change in thermodynamics can proceed in either direction, which is not true.

Black hole thermodynamics establishes a deep and satisfying link to gravity, thermodynamics, and quantum theory. And, the thermodynamic property of black hole is essentially a quantum feature of gravity. In this paper, in order to study the influence of the quantum gravity effect on the quantum properties of black hole, we study the thermodynamics and its quantum correction to a non-commutative black hole. First of all, the temperature of the non-commutative Schwarichild black hole is calculated by using three different methods: surface gravity, tunneling effects and the first law of black hole thermodynamics. It is found that the same hole temperature is obtained by means of the surface gravity and tunneling effects. However, by using the first law of black hole thermodynamics, different results are derived from the first two methods. Therefore, we incline to the result obtained by surface gravity and tunneling effects, and the temperature obtained by the thermodynamic law needs modifying. That is, for the non-commutative black hole, there is a contradiction to the first law of thermodynamics. To calculate the temperature and other thermodynamic quantities for the non-commutative Schwarichild black hole, we use the corrected first law of black hole thermodynamics proposed in the literature. It is found that the black hole temperature derived by the corrected first law is the same as the temperature obtained by the surface gravity and the tunneling model, and the black hole entropy still follows Beckenstein-Hawking area law. Also, the heat capacity of the black hole is obtained and analyzed. It is seen that when the horizon radius and non-commutative parameter satisfy the particular conditions, the heat capacity is positive and the non-commutative black holes are thermodynamically stable. This is a different result from that of the usual Schwarichild black hole. Further, by studying the influence of generalized uncertainty principle on non-commutative black hole thermodynamics, the quantum corrections from generalized uncertainty principle for temperature, entropy and heat capacity of the non-commutative Schwarzschild black hole are given. It is found that with considering this quantum gravity effect, the obtained black hole entropy contains the item of are alogarithm. If the effect of the generalized uncertainty principle is neglected, the corrected black hole entropy can return to that in the usual case of Beckenstein-Hawing area law. Similarly, the corrected black hole temperature and heat capacity can also return to their counterparts in the case of usual Schwarzschild black hole when this quantum gravity effect is ignored.

We derive the first law of thermodynamics using the method proposed by Wald. Treating the entropy as Noether charge and comparing with the usual first law of thermodynamics, we obtain explicitly the expression of entropy which contains infinitely many non-local terms (i.e. the integral terms). We have proved, in general, that the first law of black hole thermodynamics is violated for f(R,T) gravity. However, there might exist some special cases in which the first law for f(R,T) gravity is recovered.

Examining the relationships between carbon emissions and land supply in China

We explore the relationship between the first law of thermodynamics and gravitational field equation at a static, spherically symmetric black hole horizon in Ho\ifmmode \check{r}\else \v{r}\fi{}ava-Lifshitz theory with/without detailed balance. It turns out that as in the cases of Einstein gravity and Lovelock gravity, the gravitational field equation can be cast to a form of the first law of thermodynamics at the black hole horizon. This way we obtain the expressions for entropy and mass in terms of black hole horizon, consistent with those from other approaches. We also define a generalized Misner-Sharp energy for static, spherically symmetric spacetimes in Ho\ifmmode \check{r}\else \v{r}\fi{}ava-Lifshitz theory. The generalized Misner-Sharp energy is conserved in the case without matter field, and its variation gives the first law of black hole thermodynamics at the black hole horizon.

A unified first law of black-hole dynamics and relativistic thermodynamics is derived in spherically symmetric general relativity. This equation expresses the gradient of the active gravitational energy E according to the Einstein equation, divided into energy-supply and work terms. Projecting the equation along the flow of thermodynamic matter and along the trapping horizon of a black hole yield, respectively, first laws of relativistic thermodynamics and black-hole dynamics. In the black-hole case, this first law has the same form as the first law of black-hole statics, with static perturbations replaced by the derivative along the horizon. In particular, there is the expected term involving the area and surface gravity, where the dynamic surface gravity is defined by substituting the Kodama vector and trapping horizon for the Killing vector and Killing horizon in the standard definition of static surface gravity. The remaining work term is consistent with, for instance, electromagnetic work in special relativity. The dynamic surface gravity vanishes for degenerate trapping horizons and satisfies certain inequalities involving the area and energy which have the same form as for stationary black holes. Turning to the thermodynamic case, the quasi-local first law has the same form, apart from a relativistic factor, as the classical first law of thermodynamics, involving heat supply and hydrodynamic work, but with E replacing the internal energy. Expanding E in the Newtonian limit shows that it incorporates the Newtonian mass, kinetic energy, gravitational potential energy and thermal energy (internal energy with fixed zero). There is also a weak type of unified zeroth law: a Gibbs-like definition of thermal equilibrium requires constancy of an effective temperature, generalizing the Tolman condition and the particular case of Hawking radiation, while gravithermal equilibrium further requires constancy of surface gravity. Finally, it is suggested that the energy operator of spherically symmetric quantum gravity is determined by the Kodama vector, which encodes a dynamic time related to E.

We obtain the mass expression of the three- and five-dimensional Lifshitz black holes by em- ploying the recently proposed quasilocal formulation of conserved charges, which is based on the off-shell extension of the ADT formalism. Our result is consistent with the first law of black hole thermodynamics and resolves the reported discrepancy between the ADT formalism and the other conventional methods. The same mass expression of Lifshitz black holes is obtained by using an- other quasilocal method by Padmanabhan. We also discuss the reported discrepancy in the context of the extended first law of black hole thermodynamics by allowing the pressure term.

In this work, we have considered a non-canonical scalar field dark energy model in the framework of flat FRW background. It has also been assumed that the dark matter sector interacts with the non-canonical dark energy sector through some interaction term. Using the solutions for this interacting non-canonical scalar field dark energy model, we have investigated the validity of generalized second law (GSL) of thermodynamics in various scenarios using first law and area law of thermodynamics. For this purpose, we have assumed two types of horizons viz apparent horizon and event horizon for the universe and using first law of thermodynamics, we have examined the validity of GSL on both apparent and event horizons. Next, we have considered two types of entropy-corrections on apparent and event horizons. Using the modified area law, we have examined the validity of GSL of thermodynamics on apparent and event horizons under some restrictions of model parameters.

Numerical simulation of non-isothermal flow in porous media has great applications in unconventional gas recovery. Reliable and promising numerical methods should be compatible with the first and second laws of thermodynamics. Toward this goal, by taking molar density and temperature as the primary unknowns, we propose an alternative formulation of the realistic non-isothermal gas flow model, which is proved to obey the first and second laws of thermodynamics. On the basis of this formulation, we propose an energy conservative and entropy stable numerical scheme; that is, the scheme can preserve the first law of thermodynamics (the energy conservation law) as well as the second law of thermodynamics (entropy stability). An important ingredient of the scheme is to derive a new discrete chemical potential utilizing the energy factorization approach, which can preserve the dissipation of original Helmholtz free energy. Some subtle temporal and spatial treatments have also been introduced to deal with the inherent coupling relationships between multiple variables. Using the local analysis method, we prove that the scheme can be compatible with both local and global forms of the first and second laws of thermodynamics. Numerical results validate our theoretical analysis and demonstrate conservative and stable features of the proposed scheme.

Exergization

It is known that the balance laws of hyperelasticity (Green elasticity), i.e. conservation of mass and balance of linear and angular momenta, can be derived using the first law of thermodynamics and by postulating its invariance under superposed rigid body motions of the Euclidean ambient space—the Green–Naghdi–Rivlin theorem. In the case of a non-Euclidean ambient space, covariance of the energy balance—its invariance under arbitrary time-dependent diffeomorphisms of the ambient space—gives all the balance laws and the Doyle–Ericksen formula—the Marsden–Hughes theorem. It is also known that, by assuming the balance laws, and positing the first and second laws of thermodynamics, the Doyle–Ericksen formula can be derived—the Coleman–Noll procedure. Traditionally, the first law of thermodynamics combined with an invariance assumption has been used to derive the balance laws, while the second law has served to constrain constitutive equations. In this paper, we explore how the balance laws themselves can be derived directly from thermodynamic principles. We achieve this via a generalization of the Coleman–Noll procedure: it is shown that the Doyle–Ericksen formula as well as the balance laws for both hyperelasticity and hyper-anelasticity can be derived using the first and second laws of thermodynamics without assuming any (observer) invariance.

Carbon emission (CE) threatens global climate change severely, leading to the continuous strengthening of the greenhouse effect. Land use changes can greatly affect the ecosystem carbon budget and anthropogenic CE. Based on the land use grids, net ecosystem productivity (NEP), energy consumption-related CE, this study employed various methods to investigate the impact of land use change on carbon balance. The results showed 10.03% of total land use area has land use type changed between 2000 and 2015. Built-up land occupied cropland was the main land use transfer type. The period with the most intense land use changes was 2005–2010, which was constant with the process of China’s urbanization. NEP presented an overall increasing trend excluding built-up land and water areas. Temporally, CE showed an increasing trend in 2000–2015, especially in the industry sector. Spatially, areas with the high energy-related CE were mainly distributed in the south, which has a relatively high economic level. The land use intensity values of cities in Jiangsu all presented an overall increasing trend, which is related to the economic development and local endowment. Cities with higher land use intensity were usually accompanied with high CE, suppressing NEP growth. From 2000 to 2015, soil carbon storage reduced by 0.15 × 108 t, vegetation carbon storage reduced by 0.04 × 108 t, and CE reached 17.42 × 108 t. Total CE caused by land use change reached 15.46 × 108 t. The findings can make references for the low-carbon development from ecological land protection, strengthen land management, and optimize urban planning.

Understanding the effects of sloped roads in the pedestrian environment on the body during ambulation with a walking frame can help design friendlier living environments for elderly individuals. A survey of the characteristics of walking frames used in different pedestrian environments was investigated in five communities, and a controlled study of the effects of a sloped road on a subject with different walking frames was carried out as foundational research in the laboratory. A synchronous acquisition system consisting of a wireless motion capture module and a physiological information recording module was applied to collect data on the motion of the shoulder joint and skin conductance response (SCR) of fingers in one participant. Force data were collected from sensors placed on the four legs of the walking frame. The experimental data obtained during different tasks were quantitatively analyzed. Compared to flat ground, the shoulder joint rotated in the opposite direction in horizontal and internal/external planes when using a wheeled walking frame on an uphill road, and the supportive force decreased on both uphill and downhill roads. The range of motion of the shoulder joint reduced and the direction of the shoulder joint motion changed when using a footed walking frame on both uphill and downhill roads. Additionally, the peak value of the supportive force on the uphill road appeared in the first 50% of the gait cycle, which was earlier than in the other cases. In addition, walking on the uphill road with a walking frame had a maximum SCR value, which means a greater impact of psychological arousal. Biomechanics of the shoulder joint and psychological arousal are closely related to the ease of walking on a sloped road with a walking frame. These findings are beneficial for designing more appropriate environments for elderly individuals who walk with aids.

Based solely on the First Law of Thermodynamics, which addresses energy efficiency, heat pumps are considered to be a major asset for achieving the decarbonization goals of the Paris Agreement. Yet, this approach alone overestimates the potential for decarbonization and conceals certain root causes of carbon dioxide emissions arising from exergy destruction. This paper redefines the decarbonization potential of heat pumps holistically by applying the First and Second Laws of thermodynamics together. This research shows that power-to-heat energy conversion systems are responsible for exergy destruction, leading to additional carbon dioxide emissions, as the destroyed exergy must be offset by other means, possibly by burning fossil fuels. An exergy-based model was developed and used for different scenarios. Results were compared with boilers in heating mode fueled by fossil fuels or biogas, and with adsorption machines in cooling mode. Thermal energy storage systems and their optimal operational regimes for minimum environmental footprint have also been considered and modeled in accordance with the Second Law of Thermodynamics. A correction factor for the coefficient of performance of heat pumps has been developed to account for exergy destruction and emission avoidance associated with typical heat pump operation under electrical and ambient thermal inputs. Results show that today’s coefficient of performance must be higher to meet the emissions-mitigation and total electrification targets to mitigate global warming. The Second Law of thermodynamics shows that the case study about the comfort cooling system of a nature center building with ground source heat pumps and photovoltaic panels is responsible for emissions by 0.81 kg CO2 emissions/kWen-h, rather than saving 1.62 kg CO2/kWen-h by a no-heat pump case, comprising solar photovoltaic panels, adsorption cooling, and desiccant wheel. This case study also shows that the carbon dioxide emission responsibility resulting from exergy destruction during the power-to-heat process is as important as the direct emissions from electric power use. This paper concludes that the exergy destruction-related carbon footprint should not be neglected across all design and application phases to foster better awareness and establish exergy-rational strategy planning towards the Paris Agreement goals.