Interior Conditions Research Articles

Mixture of hydrogen and methane under planetary interior conditions.

We employ first-principles molecular dynamics simulations to provide equation-of-state data, pair distribution functions (PDFs), diffusion coefficients, and band gaps of a mixture of hydrogen and methane under planetary interior conditions as relevant for Uranus, Neptune, and similar icy exoplanets. We test the linear mixing approximation, which is fulfilled within a few percent for the chosen P-T conditions. Evaluation of the PDFs reveals that methane molecules dissociate into carbon clusters and free hydrogen atoms at temperatures greater than 3000 K. At high temperatures, the clusters are found to be short-lived. Furthermore, we calculate the electrical conductivity from which we derive the non-metal-to-metal transition region of the mixture. We also calculate the electrical conductivity along the P-T profile of Uranus [N. Nettelmann et al., Planet. Space Sci., 2013, 77, 143-151] and observe the transition of the mixture from a molecular to an atomic fluid as a function of the radius of the planet. The density and temperature ranges chosen in our study can be achieved using dynamic shock compression experiments and seek to aid such future experiments. Our work also provides a relevant data set for a better understanding of the interior, evolution, luminosity, and magnetic field of the ice giants in our solar system and beyond.

Extension of primal-dual interior point method based on a kernel function for linear fractional problem

Our aim in this work is to extend the primal-dual interior point method based on a kernel function for linear fractional problem. We apply the techniques of kernel function-based interior point methods to solve a standard linear fractional program. By relying on the method of Charnes and Cooper [3], we transform the standard linear fractional problem into a linear program. This transformation will allow us to define the associated linear program and solve it efficiently using an appropriate kernel function. To show the efficiency of our approach, we apply our algorithm on the standard linear fractional programming found in numerical tests in the paper of A. Bennani et al. [4], we introduce the linear programming associated with this problem. We give three interior point conditions on this example, which depend on the dimension of the problem. We give the optimal solution for each linear program and each linear fractional program. We also obtain, using the new algorithm, the optimal solutions for the previous two problems. Moreover, some numerical results are illustrated to show the effectiveness of the method.

Double superionicity in icy compounds at planetary interior conditions

The elements hydrogen, carbon, nitrogen and oxygen are assumed to comprise the bulk of the interiors of the ice giant planets Uranus, Neptune, and sub-Neptune exoplanets. The details of their interior structures have remained largely unknown because it is not understood how the compounds H2O, NH3 and CH4 behave and react once they have been accreted and exposed to high pressures and temperatures. Here we study thirteen H-C-N-O compounds with ab initio computer simulations and demonstrate that they assume a superionic state at elevated temperatures, in which the hydrogen ions diffuse through a stable sublattice that is provided by the larger nuclei. At yet higher temperatures, four of the thirteen compounds undergo a second transition to a novel doubly superionic state, in which the smallest of the heavy nuclei diffuse simultaneously with hydrogen ions through the remaining sublattice. Since this transition and the melting transition at yet higher temperatures are both of first order, this may introduce additional layers in the mantle of ice giant planets and alter their convective patterns.

Existence of solid Na–Xe compounds at the extreme conditions of Earth's interior

Existence of solid Na–Xe compounds at the extreme conditions of Earth's interior

TECHNOLOGY OF PARTICLEBOARD’S PREPARATION BY COLD PRESSING AFTER HOT MAT COMPRESSION

The article describes amethod of preparing particleboards (PB) from fresh and recycled chips by anew technology of cold pressing after hot compression of the mat according to PCT/SK2023/000007 (ÚPV SR, 13.06.2023) using polyvinyl acetate (PVAc) glue. Forcomparison, the experiment was also carried out using urea formaldehyde (UF) glue and their mutual combination. The new method shortens hot pressing, or causes reduction of pressing temperatures, while the prepared PB released from pressure no longer spring and cure over time. The curing kinetics of both PVAc and UF adhesives were described by monitoring the flexural strength and modulus of elasticity of PB as a function of time after release of pressure.Modeling of the PB pressing process based on PVAc glue, which consists of overheating the pressed cross-section of the board to 90°Cand its subsequent cooling to a temperature when the board is already stable, i.e. below a temperature of 70°C, was carried out using of a hot and cold press, while the pressing cycle lasted 140 s. Shortening the pressing cycle to 100 s was achieved by applying the glue to the chips already preheated to 92°C.Laboratory tests have confirmed that the mechanical properties of PB are in accordance with the requirements of EN 312/3 for chipboards for interior conditions, including furniture, for use in dry environments.

Ultrafast x-ray detection of low-spin iron in molten silicate under deep planetary interior conditions.

The spin state of Fe can alter the key physical properties of silicate melts, affecting the early differentiation and the dynamic stability of the melts in the deep rocky planets. The low-spin state of Fe can increase the affinity of Fe for the melt over the solid phases and the electrical conductivity of melt at high pressures. However, the spin state of Fe has never been measured in dense silicate melts due to experimental challenges. We report detection of dominantly low-spin Fe in dynamically compressed olivine melt at 150 to 256 gigapascals and 3000 to 6000 kelvin using laser-driven shock wave compression combined with femtosecond x-ray diffraction and x-ray emission spectroscopy using an x-ray free electron laser. The observation of dominantly low-spin Fe supports gravitationally stable melt in the deep mantle and generation of a dynamo from the silicate melt portion of rocky planets.

Fuzzy logic type-2 intelligent moisture control system

In this article we present a model of adjustable moisture control for historical buildings. Proposed system is developed in a form of flexible IoT infrastructure in which a complex system of sensors is set to measure inside conditions of humidity and compare result to levels of groundwaters, rain and wind speed to manage drying system. Developed control model is using type-2 fuzzy logic reasoning to flexibly adjust decisions to the intensity of water absorption. In this way proposed model makes an innovative intelligent system for control of interior conditions in historical buildings. Developed system was installed and examined in an old brewery building. Research results show efficiency in dehumidification at lowest cost.

Rocky Planet or Water World? Observability of Low-density Lava World Atmospheres

Super-Earths span a wide range of bulk densities, indicating a diversity in interior conditions beyond that seen in the solar system. In particular, an emerging population of low-density super-Earths may be explained by volatile-rich interiors. Among these, low-density lava worlds have dayside temperatures that are high enough to evaporate their surfaces, providing a unique opportunity to probe their interior compositions and test for the presence of volatiles. In this work, we investigate the atmospheric observability of low-density lava worlds. We use a radiative-convective model to explore the atmospheric structures and emission spectra of these planets, focusing on three case studies with high observability metrics and substellar temperatures spanning ∼1900–2800 K: HD 86226 c, HD 3167 b, and 55 Cnc e. Given the possibility of mixed volatile and silicate interior compositions for these planets, we consider a range of mixed volatile and rock-vapor atmospheric compositions. This includes a range of volatile fractions and three volatile compositions: water-rich (100% H2O), water with CO2 (80% H2O+20% CO2), and a desiccated O-rich scenario (67% O2+33% CO2). We find that spectral features due to H2O, CO2, SiO, and SiO2 are present in the infrared emission spectra as either emission or absorption features, depending on dayside temperature, volatile fraction, and volatile composition. We further simulate JWST secondary-eclipse observations for each of the three case studies, finding that H2O and/or CO2 could be detected with as few as ∼five eclipses. Detecting volatiles in these atmospheres would provide crucial independent evidence that volatile-rich interiors exist among the super-Earth population.

On the Interaction of Damage Evolution and Thermal Buckling in Stepped Circular Bilaminates

Abstract The behavior and evolution of stepped circular bi-laminates with edge damage are studied for structures subjected to uniform thermal load. The problem is formulated as a moving intermediate boundaries problem in the calculus of variations, where the boundary of an evolving region of damage emanating from the edge of the smaller substructure, as well as the boundary of a progressing/regressing region of sliding contact adjacent to the intact region of the composite structure are each allowed to vary along with the displacements. This yields the associated transversality conditions that define the locations of the propagating boundaries that correspond to equilibrium configurations of the evolving composite structure, as well as the equations of equilibrium and the associated interior and exterior boundary conditions. Various configurations of contact of the detached segments of the composite structure and the associated behavior are considered, and the influence and progression of contact on the overall evolution of the composite structure are assessed. Closed-form analytical solutions to the geometrically nonlinear problem are obtained, and expressions for the critical buckling load are developed. The explicit forms of the total energy release rate along the delamination front, as well as of the conditions for propagation of the contact zone boundary, are obtained from the analytical solutions and the corresponding transversality conditions. Results of numerical simulations based on the analytical solutions are presented and are seen to unveil a rich evolution process involving contact progression/recession and metamorphosis, buckling, and detachment progression during the prebuckling phase, during sling-shot buckling, and during the postbuckling phase, depending on the material properties of the sublaminates, the geometry of the sublaminates, the initial size of the damage, and the strength of the interfacial bond. Characteristic behavior of damage propagation is found to be quite robust and is seen to include stable propagation, stable followed by unstable progression, arrest, and catastrophic propagation.

Monitoring the large-scale magnetic field of AD Leo with SPIRou, ESPaDOnS, and Narval

Context. One clear manifestation of dynamo action on the Sun is the 22-yr magnetic cycle, exhibiting a polarity reversal and a periodic conversion between poloidal and toroidal fields. For M dwarfs, several authors claim evidence of activity cycles from photometry and analyses of spectroscopic indices, but no clear polarity reversal has been identified from spectropolarimetric observations. These stars are excellent laboratories to investigate dynamo-powered magnetic fields under different stellar interior conditions, that is partly or fully convective. Aims. Our aim is to monitor the evolution of the large-scale field of AD Leo, which has shown hints of a secular evolution from past dedicated spectropolarimetric campaigns. This is of central interest to inform distinct dynamo theories, contextualise the evolution of the solar magnetic field, and explain the variety of magnetic field geometries observed in the past. Methods. We analysed near-infrared spectropolarimetric observations of the active M dwarf AD Leo taken with SPIRou between 2019 and 2020 and archival optical data collected with ESPaDOnS and Narval between 2006 and 2019. We searched for long-term variability in the longitudinal field, the width of unpolarised Stokes profiles, the unsigned magnetic flux derived from Zeeman broadening, and the geometry of the large-scale magnetic field using both Zeeman-Doppler imaging and principal component analysis. Results. We found evidence of a long-term evolution of the magnetic field, featuring a decrease in axisymmetry (from 99% to 60%). This is accompanied by a weakening of the longitudinal field (−300 to −50 G) and a correlated increase in the unsigned magnetic flux (2.8–3.6 kG). Likewise, the width of the mean profile computed with selected near-infrared lines manifests a long-term evolution corresponding to field strength changes over the full time series, but does not exhibit modulation with the stellar rotation of AD Leo in individual epochs. Conclusions. The large-scale magnetic field of AD Leo manifested first hints of a polarity reversal in late 2020 in the form of a substantially increased dipole obliquity, while the topology remained predominantly poloidal and dipolar for 14 yr. This suggests that low-mass M dwarfs with a dipole-dominated magnetic field can undergo magnetic cycles.

Low-Temperature Fabrication of Flexible Dye-Sensitized Solar Cells: Influence of Electrolyte Solution on Performance under Solar and Indoor Illumination

Flexible photovoltaics is an attractive technology for product-integrated energy supply under both outdoor and interior conditions. In particular, dye-sensitized solar cells (DSSCs) based on flexible plastic conductive substrates provide ample opportunities for unique applications; however, they prevent the use of high-temperature processing steps usually applied in the fabrication of the solar cell. In the first part of this paper, we present an overview of a careful selection of the most relevant work in the field of flexible DSSCs (F-DSSCs), ranging from pioneering methodsto the most cutting-edge techniques. Key elements and critical considerations for the design of an efficient F-DSSC are also provided. In the second part, we report the fabrication of DSSCs on both rigid and flexible plastic substrates using low-temperature processing. Three different I−/I3− electrolyte configurations were tested. Rigid and F-DSSC showed 2.62% and 1.00% efficiency under 1 sun and an output power of 8.60 and 4.00 μW/cm−2 under low-light conditions, respectively. In this work, we report a novel solvent mixture that shows a significant enhancement of the performance of the low-temperature processed configuration, without adding steps in the fabrication process.

Manifestations of Urban Interiority in Delhi Gate Bazaar of Lahore

In the contemporary debate, the notion of interiority has expanded beyond the confines of the interior, in the urban realm, as a conjunction of urban and interior conditions. This article aims to contribute to the discourse, using the lens of urban interiority to explore the unique spatial character and distinct cultural practices in Lahore’s Delhi Gate Bazaar. The bazaar exists on a linear passageway, the Royal Trail, as a network of interior, exterior, and in-between spaces—establishing a spatial continuum by blurring the boundaries between the public and private and uninterrupted flow of spaces from outside to inside. This urban space has a strong sense of history, culture, and traditions; constructing personal and collective engagement through modes of space inhabitation and appropriation. These practices include temporal improvisation and modification of certain aspects for everyday use and environmental alteration for achieving thermal comfort, along with synchronised occurrences of cultural traditions and commercial activities. This article interprets observations through drawings to describe the experience of space through gradations of interiority and transition through thresholds, constructing visual narratives of diverse uses, activities, and the interaction between people, objects, and space.

The colour difference of transparent surface finish on hydrothermally treated beech wood in the interior

The colour difference of transparent surface finish on hydrothermally treated beech wood in the interior. The paper deals with the influence of ageing of transparent surface finish in the dark and in the light in interior conditions. The colour difference of the tested samples with surface finishes (∆E*ab) was measured after the ageing of native wood and hydrothermally modified wood in the dark and in the light. In the experiment,European beech wood was hydrothermally treated at a temperature of 135 C under saturated water vapour for 6 hours. Three different types of surface finishes (acrylic-polyurethane, polyacrylic and aldehyde resin, alkyd resin) were applied on the wood surfaces. The colour parameters of the surfaces in the system CIE L*a*b*, chroma ΔC*,and hue angle Δh were measured immediately after surface finishing and after the ageing in the dark and in the light. The samples were placed behind windows glass in the interior for 60 days. The results of the colour difference ∆E*ab showed that the colour of wood and the colour of the surface finishes was changed after ageing in the dark as well as in the light. The colour difference ∆E*ab was bigger in the light than in the dark. The colour difference was bigger on native wood than on hydrothermally modified wood.

Error estimates of divergence-free generalized moving least squares (Div-Free GMLS) derivatives approximations in Sobolev spaces

The divergence-free generalized moving least squares (Div-Free GMLS) approximation has recently been utilized to solve some incompressible fluid flows problems. In our recent work (Mohammadi and Dehghan (2021) [28]), we have presented its formulation more precisely, and also the error estimates of derivatives have been carried out in L∞(Ω), where Ω⊂Rd is a bounded set satisfying an interior cone condition. However, the error estimates of this vector-valued approximation in Sobolev spaces are not done. So, in this paper we make the error estimates of Div-Free GMLS derivatives approximations in Lq(Ω), where 1≤q≤∞, using a stable local divergence-free polynomial reproduction property. Note that, the method is a direct approximants of exact derivatives of a divergence-free vector field, which possesses the optimal rates of convergence. This vector-valued technique can also be developed to find the numerical solution of the incompressible fluid flows problems easier than the other available mesh-dependent methods. Finally, we have shown how the proposed approximation can recover the velocity field variable of the well-known Darcy's problem in a two-dimensional space.

IoT Enable Intelligent Smart Bin for Garbage Monitoring based on Real-Time Data Analysis

Abstract: The amount of waste being disposed of has become an issue due to the world's population growth and rapid urbanization because the infrastructure is not sufficiently established. Malaria, dengue fever, and cholera are just a few of the illnesses that render human life penalized by erroneous monitoring and cleaning of a city's trash bins. Humans suffer as a result in a variety of ways, thus in order to prevent the worst case scenario, waste bins must be monitored remotely so that they may be cleaned on a regular basis, allowing urban residents to live more safely and comfortably. By examining a bin's various components, including its level of trash, indoor humidity, temperature, and any harmful gases that might be produced due to erroneous monitoring, the burning of waste, or the storage of rainwater in a bin, the proposed work determines the interior condition of a waste bin. Here, the idea of IoT is applied to ongoing remote monitoring to ensure that the bins don't overflow, don't emit any dangerous gases or smoke, and don't pollute the environment around people.

Author Correction: Melting curve of superionic ammonia at planetary interior conditions

Author Correction: Melting curve of superionic ammonia at planetary interior conditions

Phase transitions and spin state of iron in FeO under the conditions of Earth's deep interior

Phase transitions and spin state of iron in FeO under the conditions of Earth's deep interior

Flexible Coated Conductive Textiles as Ohmic Heaters in Car Seats

Pleasant interior conditions within cars, as well as a comfortable feeling, are primary needs of car drivers to perform vital body functions during driving. In a cooler outer environment, a warming system within seats can quite feasibly maintain a realistic thermal balance in the body. An inbuilt heating system in car seats can not only provide adequate heat to the driver but is also relevant to minimizing the energy consumption within the vehicle interior. In order to evenly distribute the heat over the body contact area of the automotive seats, conductive textiles are proposed. In fact, these textiles behave as a semiconductor (as an electrical conductor and also creating resistance, which in turn creates heat). Flexible textile ohmic heaters present great advantages due to their ability to bend, stretch, and stitch. These properties make them valuable to ensure uniform heaters for irregular geometries. The present review highlights the use of different textile-based ohmic heaters, their fabrication methods, range of heating, and durability. Moreover, this review also focuses on the comparative mechanical performance and comfort properties of the presented fabrics (used in car seats). This study is beneficial for future trends of minimizing energy consumption and providing an effective way to reduce the carbon emissions and air pollution produced by vehicles.

THERMAL COMFORT ASSESSMENT FOR ADOPTING CONTROL STRATEGIES IN ATRIUM BUILDINGS

The atrium was seen in origin about two hundred years ago. Glazed areas and atrium structures have been considered a symbol of advanced technology in recent years, yet they can differ in terms of arrangement and functionality. Because of the complexity of their operation and air movement, atriums are difficult to diagnose and analyze in terms of thermal comfort. The present paper has a study on the thermal environment of atrium spaces. Thermal comfort is one of the foremost important aspects of indoor environmental quality thanks to its effects on well-being, people's performance, and building energy requirements. Since our responses to our thermal environment have a considerable effect on our performance and behavior, not least in the realm of work, there has been a considerable scientific investigation of those responses and formal methods are developed for environmental evaluation and style. Thermal sensations of the occupants occupying the interior space of the building were evaluated with various approaches to understanding indoor thermal comfort. Several metrics for assessing human thermal response to interior environment conditions have been assessed describing the human thermal perception of the thermal environment to which an individual or a group of people is exposed. The article study was to gain insight into the subject’s perspectives on variables of comfort levels and determine the factors responsible for the varying human thermal comfort summer. This paper is a study on the thermal environment of atrium spaces focusing on identifying the factors of thermal comfort and promoting Control measures that may be adopted in atrium buildings to reduce the energy potential.

Melting curve of superionic ammonia at planetary interior conditions

Melting curve of superionic ammonia at planetary interior conditions