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The article extends J. S. McMullen's 2024 entrepreneurial growth model inspired by the novel and the film "The Martian", arguing that incorporating AI and 3D printing into a closed-system environment allows for continuous, rather than just survival-driven, growth. It proposes that labor substitution, independent knowledge generation, and structural capital transformation can drive exponential growth, unlike McMullen’s entropy-limited model. By focusing on human desires for comfort and long-term innovation cycles, the model envisions sustained wealth creation even in constrained environments.

Copyright of Journal of Polytechnic is the property of Journal of Polytechnic and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

An asymptotic output feedback controller for the hydraulic systems with model uncertainty compensation and prescribed performance is proposed here, where state observers, funnel function and nonlinear adaptive controller are integrated via backstepping technology. Only position signal is available in the process of controller design, the velocity and load pressure are estimated by observers. And, the adaptive control law is carried out to approximate disturbance. Then, a funnel function is introduced to guarantee the prescribed tracking error performance and the potential singularity problem in prescribed performance control is avoided. Furthermore, the whole closed system is proved to be asymptotically stable using Lyapunov method. Comparative experimental results performed on hydraulic systems are studied to illustrate the effectiveness of the proposed controller. [ABSTRACT FROM AUTHOR]

Lucidity is obtained by understanding the differences between kinematic and radiative heat transfer and their relationships to temperature. Differences become apparent when one evaluates the utilitarian temperature associated with closed systems and compares that to temperatures measured in open systems. Acceptance, requires the realization that the sciences founded upon closed system experimentation is not always ideal for formulating open system physics. Temperatures measured in open systems that are dominated by anisotropic radiation often become non-sensible, e.g., those in Earth's upper atmosphere. [ABSTRACT FROM AUTHOR]

In this study, the first frost-heave testing apparatus with a triple cell was developed that can measure the amount of frost-heave and heaving pressure, as well as achieve high-accuracy temperature control. The performance of the apparatus was validated by a series of frost-heave tests, which were conducted in a closed system with saturated sandy soil and an initial boundary temperature of 3 °C. The effect of having multiple cells (triple cell, double cell, and single cell), different freezing directions (top to bottom, both sides, and bottom to top), and multiple temperature gradients (0.09, 0.11, and 0.13 °C/mm), was examined to investigate the frost-heave properties of sandy soil. The reliability of the testing machine was validated by comparing the measured (experimental) and estimated (theoretical) amount of frost-heave that occurs in saturated sandy soil. The results show that the newly developed testing device accurately estimates the amount of frost-heave with error of < 8.69% between predicted and measured results for heaving pressure with freezing direction from top to bottom. [ABSTRACT FROM AUTHOR]

Copyright of Multi-Knowledge Electronic Comprehensive Journal For Education & Science Publications (MECSJ) is the property of Multi-Knowledge Electronic Comprehensive Journal For Education & Science Publications (MECSJ) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

We analyze the stability of small bubbles in a closed system with fixed volume, temperature, and number of molecules. We show that there exists a minimum stable size of a bubble. Thus there exists a range of densities where no stable bubbles are allowed and the system has a homogeneous density which is lower than the coexistence density of the liquid. This becomes possible due to the finite liquid compressibility. Capillary analysis within the developed 'modified bubble' model illustrates that the existence of the minimum bubble size is associated to the compressibility and it is not possible when the liquid is strictly incompressible. This finding is expected to have very important implications in cavitation and boiling. [ABSTRACT FROM AUTHOR]

Here, it was shown that the chain of equations, which is similar to the Bogoliubov chain in the theory of classical gases, may be obtained for the quasi-averages of the products of field operators in the system of Bose particles. The closed system of dynamic equations, which accounts for both the one-particle condensate and pair correlations, was obtained at zero temperature for the case where it is sufficient to confine ourselves to taking into account the quasi-averages of one field operator and the products of two field operators. The spectrum of excitations in a spatially homogeneous state was studied, and it was shown that this spectrum has two branches: the sound branch and the branch with an energy gap at zero momentum. The possibility of the existence of quasiparticle excitations with an energy gap in superfluid helium was discussed in connection with experiments on the absorption of microwave radiation. [ABSTRACT FROM AUTHOR]

Abstract: The problem of time-optimal rotation of a rigid body in the two-dimensional case by the use of mass forming a closed system with the body has been considered. For the general case, two scalar equations for two unknowns have been obtained. When the finite position of the mass is not specified, the problem is reduced to solving a single scalar equation the root of which always exists and is unique for any boundary conditions on a known segment. The relations for the optimal control, the trajectory of the mass motion, and the Bellman function are expressed in terms of elliptic integrals. The same formulas can also be used in the case when only the distance between the mass and the coordinate origin is specified at a finite instant of time. [ABSTRACT FROM AUTHOR]

The inherent difficulty in talking about quantum decoherence in the context of quantum cosmology is that decoherence requires subsystems, and cosmology is the study of the whole Universe. Consistent histories gave a possible answer to this conundrum, by phrasing decoherence as loss of interference between alternative histories of closed systems. When one can apply Boolean logic to a set of histories, it is deemed ‘consistent’. However, the vast majority of the sets of histories that are merely consistent are blatantly nonclassical in other respects, and further constraints than just consistency need to be invoked. In this paper, I attempt to give an alternative answer to the issues faced by consistent histories, by exploring a timeless interpretation of quantum mechanics of closed systems. This is done solely in terms of path integrals in non-relativistic, timeless, configuration space. What prompts a fresh look at such foundational problems in this context is the advent of multiple gravitational models in which Lorentz symmetry is not fundamental, but only emergent. And what allows this approach to overcome previous barriers to a timeless, conditional probabilities interpretation of quantum mechanics is the new notion of records—made possible by an inherent asymmetry of configuration space. I outline and explore consequences of this approach for foundational issues of quantum mechanics, such as the natural emergence of the Born rule, conservation of probabilities, and the Sleeping Beauty paradox. [ABSTRACT FROM AUTHOR]

In this work we present a novel approach to recover objects 3D position and occupancy in a generic scene using only 2D object detections from multiple view images. The method reformulates the problem as the estimation of a quadric (ellipsoid) in 3D given a set of 2D ellipses fitted to the object detection bounding boxes in multiple views. We show that a closed-form solution exists in the dual-space using a minimum of three views while a solution with two views is possible through the use of non-linear optimisation and object constraints on the size of the object shape. In order to make the solution robust toward inaccurate bounding boxes, a likely occurrence in object detection methods, we introduce a data preconditioning technique and a non-linear refinement of the closed form solution based on implicit subspace constraints. Results on synthetic tests and on different real datasets, involving challenging scenarios, demonstrate the applicability and potential of our method in several realistic scenarios. [ABSTRACT FROM PUBLISHER]

Gold-tube pyrolysis experiments were conducted on miniature core plugs and powdered rock from a bitumen-rich sample of Eagle Ford Shale to investigate the role of rock fabric in gas generation and expulsion during thermal maturation. The samples were isothermally heated at 130, 300, 310, 333, 367, 400, and 425 °C for 72 h under a confining pressure of 68.0 MPa, corresponding to six levels of induced thermal maturity: pre-oil generation (130 °C/72 h), incipient oil/bitumen generation (300 and 310 °C/72 h), early oil generation (333 °C/72 h), peak oil generation (367 °C/72 h), early oil cracking (400 °C/72 h), and late oil cracking (425 °C/72 h). Experimental results show that gas retention coupled with compositional fractionation occurs in the core plug experiments and varies as a function of thermal maturity. During the incipient oil/bitumen generation stage, yields of methane through pentane (C 1 –C 5 ) from core plugs are significantly lower than those from rock powder, and gases from core plugs are enriched in methane. However, the differences in C 1 –C 5 gas yield and composition decrease throughout the oil generation stage, and by the oil cracking stage no obvious compositional difference in C 1 –C 5 gases exists. The decrease in the effect of rock fabric on gas yield and composition with increasing maturity is the result of an increase in gas expulsion efficiency. Pyrolysis of rock powder yields 4–16 times more CO 2 compared to miniature core plugs, with δ 13 C CO2 values ranging from −2.9‰ to −0.6‰, likely due to carbonate decomposition accelerated by reactions with organic acids. Furthermore, lower yields of gaseous alkenes and H 2 from core plug experiments suggest that the rock fabric plays a role in promoting hydrogenation reactions of alkenes. [ABSTRACT FROM AUTHOR]

Core determination of present work is to analyze the influence of nanoparticle of Copper (II) oxide within the base fluid (water) enclosed in a partially heated rhombus shaped cavity. A square cylinder is fixed at the center of rhombus and kept fix with the uniform heat. For thermal management of enclosed nanofluid, various conditions are adjusted at the walls of rhombus in such a way that bottom side is heated and upper mean side is adiabatic, while rest of the portion is kept cold. Effective thermal conductivity and viscosity of nanofluid is used in term of static and Brownian via KKL approach. The governing partial differential equations are first converted into the dimensionless form using the variable transformation. Then numerical solution of the model is obtained using Finite Element Method (FEM). Simulation is performed for different heated portion of bottom length ( L ), Rayleigh number ( Ra ), nanoparticle volume fraction ( ϕ ) and three kind of heat conditions (cold, adiabatic and hot) at the surface of inner square cylinder. In order to check the rate of heat transfer within the entire cavity, various heated lengths are considered for rhombus. Performance of temperature and velocities (along x and y -directions) is computed at the mean position of the cavity. Significant influence of inner heated square cylinder is found and it is determined that cold square cylinder resist the influence of heat transfer in the entire domain of the cavity. [ABSTRACT FROM AUTHOR]

Volterra’s model for population growth in a closed system consists in an integral term to indicate accumulated toxicity besides the usual terms of the logistic equation. Scudo in 1971 suggested the Volterra model for a population u(t) of identical individuals to show crowding and sensitivity to “total metabolism”: du/dt=au(t)-bu2(t)-cu(t)∫0tu(s)ds. In this paper our target is studying the existence and uniqueness as well as approximating the following Caputo-Fabrizio Volterra’s model for population growth in a closed system:  CFDαu(t)=au(t)-bu2(t)-cu(t)∫0tu(s)ds, α∈[0,1], subject to the initial condition u(0)=0. The mechanism for approximating the solution is Homotopy Analysis Method which is a semianalytical technique to solve nonlinear ordinary and partial differential equations. Furthermore, we use the same method to analyze a similar closed system by considering classical Caputo’s fractional derivative. Comparison between the results for these two factional derivatives is also included. [ABSTRACT FROM AUTHOR]

We determined multiple closed-shell Hartree-Fock-Roothaan solutions for the systems: BH, FH, LiH, and OH, considering double and triple zeta bases. To calculate them, we used the self-consistent field method and the algebraic method. The Hartree-Fock solutions obtained were classified with respect to the kind of extreme. All these extremes generate the same configuration interaction space. Our key objective in this work is to illustrate that it is possible to obtain a wide variety of Hartree-Fock solutions for any molecular system. [ABSTRACT FROM AUTHOR]

Measuring the respiration rate of fresh produce is essential to design modified atmosphere packaging systems to extend their shelf life. A simple and common way of determining the rates of consumption of oxygen and production of carbon dioxide is to measure their variation in a closed system. In this work the respiration rate of cherry tomatoes was measured in a closed system at 5, 10, 15 and 20 °C. The results could be explained by a constant and temperature independent respiratory quotient (1.20 ± 0.01) and a Michaelis-Menten (M-M) model. The analysis of the joint confidence region showed that the two M-M parameters have a very high collinearity, where data of one single temperature set can provide misleading values. The results showed that parameter K M could be considered independent of temperature but only has statistical significance at higher temperatures, while V M varied with temperature with a stronger curvature than an Arrhenius model would suggest, with a parabolic functionality giving excellent results, albeit with no linear term, thus having the same number of parameters as an Arrhenius equation. This was due to a small increase in the rate between 5 and 10 °C. The data analysis clearly showed the importance of assessing the joint confidence region to ensure robust respiration rate model parameters. [ABSTRACT FROM AUTHOR]

The effect of initial densities in a free energy based two-phase-flow lattice Boltzmann method for non-ideal fluids with a curved interface was investigated in the present work. To investigate this effect, the initial densities in the liquid and gas phases coming from the saturation points and the equilibrium state were adopted in the simulation of a static droplet in an open and a closed system. For the purpose of simplicity and easier comparison, the closed system is fabricated by the implementation of the periodic boundary condition at the inlet and outlet of a gas channel, and the open system is fabricated by the implementation of a constant flux boundary condition at the inlet and a free-out boundary condition at the outlet of the same gas channel. By comparing the simulation results from the two types of initial densities in the open and closed systems, it is proven that the commonly used saturation initial densities setting is the reason for droplet mass and volume variation which occurred in the simulation, particularly in the open system with a constant flux boundary condition. Such problems are believed to come from the curvature effect of the surface tension and can be greatly reduced by adopting the initial densities in the two phases from equilibrium state. [ABSTRACT FROM AUTHOR]

Hydrocarbon gas expulsion from coal source rocks takes place under conditions intermediate between an open and closed system. The compositional and isotopic changes of hydrocarbon gases generated from Paleogene coal with increasing maturity were investigated under semi-open and closed system laboratory pyrolysis to evaluate the maturity level at the time of hydrocarbon gas expulsion. Lower yields of saturated hydrocarbon gases and their higher δ 13 C values were observed in the semi-open system pyrolysis compared to those at the same maturity level in the closed system pyrolysis, since gaseous hydrocarbons depleted in 13 C were removed during semi-open system pyrolysis. The δ 2 H values of hydrocarbon gases generated in the closed system pyrolysis were initially lower than those in the semi-open system pyrolysis, and then became markedly higher at the higher maturity level (vitrinite reflectance [VR r ] > 1.2%), indicating significant hydrogenation of isotopically heavier inorganic hydrogen derived from water moisture in the coal matrix. The semi-open and closed system pyrolysis showed that the relationship between the isotopic composition of hydrocarbon gases expelled from coal and the maturity of coal depends on the state of openness or closedness of the hydrocarbon generation environment. Diagrams showing the relationship between the δ 13 C values of hydrocarbon gases expelled from Paleogene coal and the VR r under conditions intermediate between semi-open and semi-closed systems were proposed for evaluating the timing of hydrocarbon gas expulsion in sedimentary basins. [ABSTRACT FROM AUTHOR]

A simulation mathematical model is proposed for the analysis of energy intensity of mushrooms production and greenhouse plants in the closed system of heating and ventilation of greenhouses of the type "plant greenhouse - mushroom greenhouse". [ABSTRACT FROM AUTHOR]

A list of substances that can be used as low-temperature refrigerants for cryogranulation in cryochemical technology is provided. The substances are analyzed according to a criterion that considers the thermodynamic and transport properties of refrigerants. Data from a performance evaluation of various refrigerants are presented. For example, butane has properties that allow high efficiency to be achieved when it is used as a refrigerant but it is a flammable and explosive material, which limits its use. [ABSTRACT FROM AUTHOR]

The critical realist (CR) conception of open and closed (O&C) systems is not about systems: it is about (ir)regularities in the flux of events and states of affairs. It has recently been criticised on the grounds that critical realists (CRs) should take on board ideas about the general nature of systems; recognise that genuinely open social systems would be impossible; avoid polarities or dualisms where either there are event regularities and open systems, or there are no event regularities and closed systems and accept partial regularities and partially open systems; and understand that orthodox economics is not based upon event regularities, laws or Humean empiricism. The objective of this paper is to 'take stock' of these recent criticisms. [ABSTRACT FROM AUTHOR]

Copyright of Cinta de Moebio is the property of Universidad de Chile, Facultad de Ciencas Sociales and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Anhydrous closed-system pyrolysis experiments were conducted on the pure alkyl naphthalenes, n -alkanes and three crude oils at the highly to over mature stage in order to investigate compositional and isotopic changes of individual aromatic hydrocarbons during laboratory maturation. On the whole, aromatic hydrocarbons have better thermal stability than n -alkanes. While the carbon isotopic composition of substituted aromatic hydrocarbons exhibits a positive correlation with increasing thermal maturity, there is no significant fractionation in the carbon isotopic composition of unsubstituted aromatic hydrocarbons. This finding suggests that the carbon isotopic distribution of unsubstituted aromatic hydrocarbons can be used as an effective tool for oil-oil and oil-source correlation, especially for highly-over mature fields. [ABSTRACT FROM AUTHOR]

The exergy balance equation can be written expressing the useful work for a general process as depending on the useful work for the corresponding reversible process and the exergy destruction term. However, this can be made only if the terms (other than the exergy destruction term) on the exergy balance equation for the general process lead to the same result as the terms on the exergy balance equation for the corresponding reversible process. It is shown that this is not generally the case for unsteady processes, and that this can be the case for steady processes, for both closed and open systems. It is also shown that this is not generally the case for unsteady processes in terms of instantaneous powers, but that this can be the case for the whole unsteady processes. This is an important result, for: ( i ) Expressing the useful work for a general process as depending on the useful work for the corresponding reversible process and the exergy destruction; ( ii ) Exergy analysis; and ( iii ) The teaching/learning process of exergy and exergy analysis, and a better understanding and application of the exergy balance equation. [ABSTRACT FROM AUTHOR]

We generalize the Maxwell drop evaporation equation to cover the range from closed system to open system through semiclosed system where the evaporation is restricted to an arbitrary degree which we show how to characterize. We first consider a suspended drop, and then a drop contacting a surface where the surface's vicinity restricts the evaporation paths. We show how to use these results to obtain arbitrary values of vapor pressure by simple manipulations of the numbers and sizes of droplets added to the system for a constant leak size, or, alternatively, control the leak size with a valve for given sizes of drops. We further show how to use this result to quantify a leakage in a system. Such a leakage is characterized using a single parameter (leakage length) which the described method calibrates. The calibrated leakage length can be used for systematic control of vapor concentrations within the chamber. © 2016 American Institute of Chemical Engineers AIChE J, 62: 4548-4553, 2016 [ABSTRACT FROM AUTHOR]

In this paper, we study the notion of -modules over -algebras of fractions relative to a -closed system and investigate some of their properties. Also, we define the notions of Noetherian and Artinian -modules over -algebras and we state some equivalent definitions of Noetherian and Artinian -modules. In addition, we study the Noetherian and Artinian over product of two -modules. [ABSTRACT FROM AUTHOR]

The method with minimal errors considering transient mass transfer time relaxation parameter for the phase change process is proposed in this study. A model coupled Volume of Fluid (VOF) model, phase change model and continuum surface force model is developed to simulate heat transfer characteristics and phase change process for a two-phase closed thermosyphon. The mass transfer process is implemented by adding User Define Function (UDF) to FLUENT code. The results obtained from this study show that the model with transient mass transfer time relaxation parameter has smaller relative errors (0.27–0.73%) for absolute temperature distributions along the wall of a two-phase closed thermosyphon than the model without transient mass transfer time relaxation parameter (2.01–2.97%). The model with transient mass transfer time relaxation parameter has smaller relative errors for the thermal resistances at evaporation and condensation sections (3.21–4.23% and 2.45–6.78%) than the model without transient mass transfer time relaxation parameter (18.31–21.74% and 15.34–28.25%), respectively. The model developed in this study can also detail the phase change process and therefore can be used to predict heat performance better for different types of heat pipes. [ABSTRACT FROM AUTHOR]

This paper presents a new model-based algorithm that computes predictive optimal controls online and in a closed loop for traditionally challenging nonlinear systems. Examples demonstrate the same algorithm controlling hybrid impulsive, underactuated, and constrained systems using only high-level models and trajectory goals. Rather than iteratively optimizing finite horizon control sequences to minimize an objective, this paper derives a closed-form expression for individual control actions, i.e., control values that can be applied for short duration, that optimally improve a tracking objective over a long time horizon. Under mild assumptions, actions become linear feedback laws near equilibria that permit stability analysis and performance-based parameter selection. Globally, optimal actions are guaranteed existence and uniqueness. By sequencing these actions online, in receding horizon fashion, the proposed controller provides a min–max constrained response to a state that avoids the overhead typically required to impose control constraints. Benchmark examples show that the approach can avoid local minima and outperform nonlinear optimal controllers and recent case-specific methods in terms of tracking performance and at speeds that are orders of magnitude faster than traditionally achievable ones. [ABSTRACT FROM AUTHOR]

Films of CdMgTe solid solutions have been grown by thermal evaporation of powders of CdTe-based MgTe-CdTe solid solutions in a quasi-closed system. The magnesium content of the films has been found to be lower than that of the source material used for film growth. It has been shown that the photocurrent amplitude in the CdMgTe films as a function of incorporated CdCl concentration has a maximum at a particular cadmium chloride concentration, which is due to the doping of the solid solutions with chloride ions. The cadmium chloride-activated CdMgTe films are n-type. [ABSTRACT FROM AUTHOR]

High-resolution records of the stable isotopic (δ 18 O and δD) composition of ice within two closed system (hydrostatic) pingos indicate a complex history of ice formation by segregation and injection and pingo growth. Physical properties and internal structure of continuous ice cores in the center of the Weather Pingo near Prudhoe Bay, Alaska, and the Pestsovoye Pingo, in northwestern Siberia, were described and then sub-sampled for analysis of the isotopic composition. Changes in the isotopic signature and physical properties of ice with depth reveal distinct patterns in both pingos indicative of ice growth as permafrost aggraded into the drained lake basin. In the initial stages following active layer deepening and initial freeze back, in-situ water migrating toward the freezing front froze at a relatively rapid rate as revealed by a complex isotopic record and small ice crystal size in the cores of Weather Pingo. Once the water supply became limited, freezing under equilibrium conditions resulted in an isotopic composition consistent with Rayleigh-type fractionation and δ 18 O and δD values that become more negative with depth. The data for the Pestsovoye Pingo reveal similar trends related to the initial stages of water migration and freezing, followed by isotopic fractionation under equilibrium conditions as unfrozen water available in the talik beneath the pingo became limited. Most of the ice in both pingos (~ 50%) formed during this final stage of permafrost aggradation. Thus temporal variability in water migration and freezing rate at the base of each pingo created a complex isotopic stratigraphy and ice growth history. [ABSTRACT FROM AUTHOR]

This study evaluates in detail the mineral chemistry, whole-rock and mineral separate Os-isotope compositions of distinct platinum-group mineral (PGM) assemblages in an isolated chromitite pod at Harold's Grave which occurs in mantle tectonite in the Shetland Ophiolite Complex (SOC), Scotland. This was the first ophiolite sequence worldwide that was shown to contain ppm levels of all six platinum-group elements (PGE) in podiform chromitite, including the contrasting type localities found here and at Cliff. At Harold's Grave the primary PGM assemblage is composed mainly of laurite and/or Os-rich iridium and formed early together with chromite, whereas the secondary PGM assemblage dominated by laurite, Os-rich laurite, irarsite, native osmium and Ru-bearing pentlandite is likely to reflect processes including in-situ serpentinization, alteration during emplacement and regional greenschist metamorphism. The osmium isotope data define a restricted range of ‘unradiogenic’ 187 Os/ 188 Os values for coexisting laurite and Os-rich alloy pairs from ‘primary’ PGM assemblage (0.12473–0.12488) and similar ‘unradiogenic’ 187 Os/ 188 Os values for both ‘primary’ and ‘secondary’ PGM assemblages (0.1242 ± 0.0008 and 0.1245 ± 0.0006, respectively), which closely match the bulk 187 Os/ 188 Os value of their host chromitite (0.1240 ± 0.0006). The unprecedented isotopic similarity between primary or secondary PGM assemblages and chromitite we report suggests that the osmium isotope budget of chromitite is largely controlled by the contained laurite and Os-rich alloy. This demonstrates that closed system behaviour of the Re–Os isotope system is possible, even during complex postmagmatic hydrothermal and/or metamorphic events. The preserved mantle Os-isotope signatures provide further support for an Enstatite Chondrite Reservoir (ECR) model for the convective upper mantle and are consistent with origin of the complex as a Caledonian ophiolite formed in a supra-subduction zone setting shortly before obduction. [ABSTRACT FROM AUTHOR]

An analytical formulation for the induced drag minimization of closed wing systems is presented. The method is based on a variational approach, which leads to the Euler-Lagrange integral equation in the unknown circulation distribution. It is shown for the first time that the augmented Munk's minimum induced drag theorem, formulated in the past for open single-wing systems, is also applicable to closed systems, joined wings and generic biwings. The quasi-closed C-wing minimum induced drag conjecture discussed in the literature is addressed. Using the variational procedure presented in this work, it is also shown that in a general biwing, under optimal conditions, the aerodynamic efficiency of each wing is equal to the aerodynamic efficiency of the entire wing system (biwing's minimum induced drag theorem). This theorem holds even if the two wings are not identical and present different shapes and wingspans; an interesting direct consequence of the theorem is discussed. It is then verified (but yet not demonstrated) that in a closed path, the minimum induced drag of the biwing is identical to the optimal induced drag of the corresponding closed system (closed system's biwing limit theorem). Finally, the nonuniqueness of the optimal circulation for a closed wing system is rigorously addressed, and direct implications in the design of joined wings are discussed. [ABSTRACT FROM AUTHOR]

An invariant procedure for the minimization of induced drag of generic biwings and closed systems (Joined Wings) was presented in the companion paper (minimum induced drag theorems for Joined Wings, closed systems, and generic biwings: theory) and is now adopted to study several theoretical open questions regarding these configurations. It is numerically verified that a quasi-closed C-wing presents the same optimal induced drag and circulation of the corresponding closed system. It is also verified that when the two wings of a biwing are brought close to each other so that the lifting lines identify a closed path, the minimum induced drag of the biwing is identical to the optimal induced drag of the corresponding closed system. The optimal circulation of this case differs from the quasi-closed C-wing one by an additive constant. The non-uniqueness of the optimal circulation for a closed wing system is also addressed, and it is shown that there are an infinite number of equivalent solutions obtained by adding an arbitrary constant to a reference optimal circulation. This property has direct positive impact in the design of Joined Wings as far as the wing load repartition is concerned: The percentage of aerodynamic lift supported by each wing can be modified to satisfy other design constraints, and without induced drag penalty. Finally, the theoretical open question regarding the asymptotic induced drag behavior of Joined Wings, when the vertical aspect ratio approaches infinity, has been resolved. It has been shown that for equally loaded wings indefinitely distant from each other, the boxwing minimum induced drag tends to zero. In that condition, the upper and lower wings present a constant aerodynamic load. Prandtl's approximated formula for the minimum induced drag of a boxwing (Best Wing System) cannot be used to describe the asymptotic behavior. This work also shows that the optimal distribution over the equally loaded horizontal wings of a boxwing is not the superposition of a constant and an elliptical functions. This is an acceptable approximation only for small vertical aspect ratios (of aeronautical interest). [ABSTRACT FROM AUTHOR]

Closed-system pyrolysis experiments were conducted on coal and carbonaceous mudstone samples using gold tubes pressured to investigate the gas generation potential and evolution. The results indicate that the total gas potential of coal is 5 times that of carbonaceous mudstone, and the total oil concentration is 2.5 times that of carbonaceous mudstone. Methane continuously increased with increasing temperature of pyrolysis. The increase ratio of heavy hydrocarbon gas is the largest at low temperature. The gas evolution of both samples is controlled by activation energy. Coal can be divided into four stages, namely kerogen degradation, kerogen cracking, oil cracking, and C2cracking stage. Carbonaceous mudstone can be divided into kerogen cracking and oil cracking. The temperature of turning point for coal is higher than carbonaceous mudstone. [ABSTRACT FROM AUTHOR]

Copyright of Environmental Research, Engineering & Management / Aplinkos Tyrimai, Inžinerija ir Vadyba is the property of Institute of Environmental Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Closed cycle systems offer an opportunity for solar energy harvesting and storage all within the same material. Photon energy is stored within the chemical conformations of molecules and is retrieved by a triggered release in the form of heat. Until now, such solar thermal fuels (STFs) have been largely unavailable in the solid-state, which would enable them to be utilized for a multitude of applications. A polymer STF storage platform is synthesized employing STFs in the solid-state. This approach enables uniform films capable of appreciable heat storage of up to 30 Wh kg−1 and that can withstand temperature of up to 180 °C. For the first time a macroscopic energy release is demonstrated using spatial infrared heat maps with up to a 10 °C temperature change. These findings pave the way for developing highly efficient and high energy density STFs for applications in the solid-state. [ABSTRACT FROM AUTHOR]

The notion of 'closed systems' in Quantum Mechanics is discussed. For this purpose, we study two models of a quantum mechanical system P spatially far separated from the 'rest of the universe' Q. Under reasonable assumptions on the interaction between P and Q, we show that the system P behaves as a closed system if the initial state of P ∨ Q belongs to a large class of states, including ones exhibiting entanglement between P and Q. We use our results to illustrate the non-deterministic nature of quantum mechanics. Studying a specific example, we show that assigning an initial state and a unitary time evolution to a quantum system is generally not sufficient to predict the results of a measurement with certainty. [ABSTRACT FROM AUTHOR]

The development of complex alteration layers on silicate mineral surfaces undergoing dissolution is a widely observed phenomenon. Given the complexity of these layers, most kinetic models used to predict rates of mineral–fluid interactions do not explicitly consider their formation. As a result, the relationship between the development of the altered layers and the final dissolution rate is poorly understood. To improve our understanding of the relationship between the alteration layer and the dissolution rate, we developed a spatially resolved surface kinetic model for olivine dissolution and applied it to a series of closed-system experiments consisting of three-phases (water (±NaCl), olivine, and supercritical CO 2 ) at conditions relevant to in situ mineral carbonation ( i.e. 60 °C, 100 bar CO 2 ). We also measured the corresponding δ 26/24 Mg of the dissolved Mg during early stages of dissolution. Analysis of the solid reaction products indicates the formation of Mg-depleted layers on the olivine surface as quickly as 2 days after the experiment was started and before the bulk solution reached saturation with respect to amorphous silica. The δ 26/24 Mg of the dissolved Mg decreased by approximately 0.4‰ in the first stages of the experiment and then approached the value of the initial olivine (−0.35‰) as the steady-state dissolution rate was approached. We attribute the preferential release of 24 Mg to a kinetic effect associated with the formation of a Mg-depleted layer that develops as protons exchange for Mg 2+ . We used experimental data to calibrate a surface kinetic model for olivine dissolution that includes crystalline olivine, a distinct “active layer” from which Mg can be preferentially removed, and secondary amorphous silica precipitation. By coupling the spatial arrangement of ions with the kinetics, this model is able to reproduce both the early and steady-state long-term dissolution rates, and the kinetic isotope fractionation. In the early stages of olivine dissolution the overall dissolution rate is controlled by exchange of protons for Mg, while the steady-state dissolution rate is controlled by the net removal of both Mg and Si from the active layer. Modeling results further indicate the importance of the spatial coupling of individual reactions that occur during olivine dissolution. The inclusion of Mg isotopes in this study demonstrates the utility of using isotopic variations to constrain interfacial mass transfer processes. Alternative kinetic frameworks, such as the one presented here, may provide new approaches for modeling fluid–rock interactions. [ABSTRACT FROM AUTHOR]

Problems and the outlook for the development of effective systems of controlling the thermal regimes of spacecraft are considered. The process of creating and using the apparatus of mathematical modeling for the purpose of comparing the energy characteristics of different systems is described. The characteristics of forward and reverse working cycles of two-phase closed systems that control the thermal regimes are compared. [ABSTRACT FROM AUTHOR]

Orbital-based exchange (x) correlation (c) energy functionals, leading to the optimized effective potential (OEP) formalism of density-functional theory (DFT), are gaining increasing importance in ground-state DFT, as applied to the calculation of the electronic structure of closed systems with a fixed number of particles, such as atoms and molecules. These types of functionals prove also to be extremely valuable for dealing with solid-state systems with reduced dimensionality, such as is the case of electrons trapped at the interface between two different semiconductors, or narrow metallic slabs. In both cases, electrons build a quasi-two-dimensional electron gas, or Q2DEG. We provide here a general DFT-OEP formal scheme valid both for Q2DEGs either isolated (closed) or in contact with a particle bath (open), and show that both possible representations are equivalent, being the choice of one or the other essentially a question of convenience. Based on this equivalence, a calculation scheme is proposed which avoids the noninvertibility problem of the density response function for closed systems. We also consider the case of spontaneously spin-polarized Q2DEGs, and find that far from the region where the Q2DEG is localized, the exact x-only exchange potential approaches two different, spin-dependent asymptotic limits. As an example, aside from these formal results, we also provide numerical results for a spin-polarized jellium slab, using the new OEP formalism for closed systems. The accuracy of the Krieger-Li-Iafrate approximation has been also tested for the same system, and found to be as good as it is for atoms and molecules. [ABSTRACT FROM AUTHOR]

In this paper, we introduce for the first time the neutrosophic system and neutrosophic dynamic system that represent new per-spectives in science. A neutrosophic system is a quasi- or (t, i, f,)- classical system, in the sense that the neutrosophic system deals with quasi-terms/concepts/attributes, etc. [or (t, i, f,) - terms/ concepts/attributes], which are approximations of the classical terms/concepts/attributes, i.e. they are partially true/membership/probable (t%), partially indeterminate (i%), and partially false/nonmember-ship/improbable (f%), where t, i, f, are subsets of the unitary interval [0,1]. {We recall that 'quasi' means relative(ly), approximate(ly), almost, near, partial(ly), etc. or mathematically 'quasi' means (t, i, f,) in a neutrophic way.} [ABSTRACT FROM AUTHOR]

An energy-input analysis of the life-cycle of microalgal cultivation systems was performed to study the oil-rich biomass production from fast-growing microalgae, for biodiesel production purposes. We estimated and compared the energy demands for the algal biomass cultivation in open-ponds (OP) with that required in closed-system photobioreactors (PBR) based on the new technologies. We also present the best microalgal candidates that show the highest biomass productivity and lipid yield indoors (laboratory scale), and discuss their potential to be used for full-scale biodiesel production. The results show that the energy requirements are highly dependent on the final mass concentration and/or using industrial wastes, with PBR cultivation being the largest energy consumer. Our offered scenario to minimize energy inputs and to increase algal-oil yields considers the most ideal cases, which could be the most promising model for energy-efficient biofuel production. Although biodiesel production by any of these systems is still not economically competitive with fossil fuel, recent suggestions on how to increase the efficiency of both systems are discussed, based on our energy-input assessment, with a critical evaluation of all stages for large-scale production of oil-rich microalgal biomass. [ABSTRACT FROM AUTHOR]

Biotite dissolution rates were determined at 25 °C, at pH 2–6, and as a function of mineral composition, grain size, and aqueous organic ligand concentration. Rates were measured using both open- and closed-system reactors in fluids of constant ionic strength. Element release was non-stoichiometric and followed the general trend of Fe, Mg > Al > Si. Biotite surface area normalised dissolution rates ( r i ) in the acidic range, generated from Si release, are consistent with the empirical rate law: r i = k H, i a H + xi where k H, i refers to an apparent rate constant, a H + designates the activity of protons, and x i stands for a reaction order with respect to protons. Rate constants range from 2.15 × 10 −10 to 30.6 × 10 −10 (moles biotite m −2 s −1 ) with reaction orders ranging from 0.31 to 0.58. At near-neutral pH in the closed-system experiments, the release of Al was stoichiometric compared to Si, but Fe was preferentially retained in the solid phase, possibly as a secondary phase. Biotite dissolution was highly spatially anisotropic with its edges being ∼120 times more reactive than its basal planes. Low organic ligand concentrations slightly enhanced biotite dissolution rates. These measured rates illuminate mineral–fluid–organism chemical interactions, which occur in the natural environment, and how organic exudates enhance nutrient mobilisation for microorganism acquisition. [ABSTRACT FROM AUTHOR]

A closed system of differential-difference equations describing thermal processes in one-dimensional harmonic crystals is obtained in the paper. An equation connecting the heat flow and the kinetic temperature is obtained as a solution of the system. The obtained law of heat conduction is different from Fourier's law and results in an equation that combines properties of the standard heat equation and the wave equation. The resulting equation is an analytic consequence from the dynamical equations for the particles in the crystal. Unlike equations of hyperbolic heat conduction, this equation is time-reversible and has only one independent parameter. A general analytical solution of this differential equations is obtained, and the analytical results are confirmed by computer simulations. [ABSTRACT FROM AUTHOR]

Cooling towers are required in building HVAC systems that use water as the cooling condenser fluid. Cooling towers used in this study are of the forced draft, counter flow, indirect/closed evaporative type. This study sought to demonstrate the performance characteristics of a closed system cooling tower by its effectiveness value, Number of Transfer Units (NTU), cooling capacity, and overall heat transfer and mass coefficient of the cooling tower. Experiments were performed on a heat exchanger coil intercrossed with ? inch diameter intersections on parallel lines. Results of the experiment were then compared with the heat and mass transfer correlations taken from previous studies, and also combined with Computational Fluid Dynamics (CFD) simulations to examine the physical processes that occur in the cooling towers. All the experimental results, theoretical calculations and CFD simulations used variations of warm water mass, cold air, and water spray to present a clear description of the performance characteristics of a closed system cooling tower. The results of this study have shown that an increase in the amount of water spray mass flow causes an increase in the effectiveness value, heat transfer and overall mass transfer, as well as the cooling capacity of the cooling tower. The waste heat typically utilizes up to 80% of latent evaporation heat, and 20% of sensible air heat; however, waste heat in the closed system cooling tower utilizes 100% of latent evaporation heat. The mass transfer coefficient rate tends to be stable for a small mass of water spray. [ABSTRACT FROM AUTHOR]

We report a new limitation on the ability of physical systems to perform computation--one that is based on generalizing the notion of memory, or storage space, available to the system to perform the computation. Roughly, we define memory as the maximal amount of information that the evolving system can carry from one instant to the next. We show that memory is a limiting factor in computation even in lieu of any time limitations on the evolving system--such as when considering its equilibrium regime. We call this limitation the space-bounded Church-Turing thesis (SBCT). The SBCT is supported by a simulation assertion (SA), which states that predicting the long-term behavior of bounded-memory systems is computationally tractable. In particular, one corollary of SA is an explicit bound on the computational hardness of the long-term behavior of a discrete-time finite-dimensional dynamical system that is affected by noise. We prove such a bound explicitly. [ABSTRACT FROM AUTHOR]

We semi-analytically capture the effects of evaporation and condensation at menisci on apparent thermal slip lengths for liquids suspended in the Cassie state on ridge-type structured surfaces using a conformal map and convolution. An isoflux boundary condition is prescribed at solid-liquid interfaces and a constant heat transfer coefficient or isothermal one at menisci. We assume that the gaps between ridges, where the vapor phase resides, are closed systems; therefore, the net rates of heat and mass transfer across menisci are zero. The reduction in apparent thermal slip length due to evaporation and condensation relative to the limiting case of an adiabatic meniscus as a function of solid fraction and interfacial heat transfer coefficient is quantified in a single plot. The semi-analytical solution method is verified by numerical simulation. Results suggest that interfacial evaporation and condensation need to be considered in the design of microchannels lined with structured surfaces for direct liquid cooling of electronics applications and a quantitative means to do so is elucidated. The result is a decrease in thermal resistance relative to the predictions of existing analyses which neglect them. [ABSTRACT FROM AUTHOR]

Since the late 1960s, oil mist has excelled as an unusually simple and highly dependable lube application method. This article provides a relevant experience update on closed oil mist systems, summarizing the primary advantages of oil mist, discusses ‘old-style open’ and ‘new style closed’ oil mist applications and asks what, if anything, can shut down an oil mist system. [ABSTRACT FROM AUTHOR]