Thermal Diffusivity Research Articles

Determination of Thermal Properties of Autoclaved Aerated Concrete Wall Sections Constructed with Distinct Mortars by the Experimental and Theoretical Data

This study investigated the thermal properties of autoclaved aerated concrete(AAC) wall sections constructed with distinct mortars. Within the scope of the study, four distinct wall sections of 25x25x5cm dimensions were created using AAC special adhesive mortar, cement mortar, lime mortar and cement-lime mortar. The thermal conductivity(λEXP) that was determined by the heat flow meter(HFM) method and bulk density(ρEXP) of each wall section was determined in the laboratory. Specific heat values(cEXP) of mortars and aerated concrete material were determined experimentally in the study. The thermal diffusivity value(αEXP), thermal effusivity value(eEXP) and volumetric heat capacity(VHCEXP) of each wall sample were calculated using the experimental data obtained in the laboratory. In addition, αTEO, eTEO and VHCTEO of each wall sample were calculated theoretically using the thermal conductivity, bulk density and specific heat value given in the literature and standards for the same wall sections. In the study, experimental data was compared to the theoretical data. As a result, the thermal properties of walls constructed with distinct mortars and thermal differences formed in the walls due to the effect of these mortars could be determined with experimental data. However, it was observed that theoretical data were insufficient to detect these thermal differences.

Assembly of artificial photo-enzyme coupling nanoreactor for boosting photodegradation of trace bisphenol A pollutant in water

It is a difficult issue to remove the trace persistent organic phenolic pollutants in water. Herein, a new artificial horseradish peroxidase (HRP)/hierarchical carbon nitride (HCN) photo-enzyme coupling nanoreactor is assembled by immobilizing HRP on HCN, which achieves the high-efficiency degradation performance for trace bisphenol A (BPA) in water. Besides the promoted charge separation efficiency as well as visible light harvest capacity, the hollow and abundant pores structure of HCN/HRP can provide a confinement effect and molecular diffusion channels to promote photo-enzyme synergic catalytic effect, thus boosting degradation reaction of BPA. Compared with original HCN, the optimal HCN/HRP-3 sample obtain a higher degradation rate of 0.0575 min−1, which is 3.60 and 125 times as large as that over original HCN (0.016 min−1) and HRP (0.00046 min−1), respectively. Meanwhile, the mineralization ability of the HCN/HRP photo-enzyme coupling nanoreactor is enhanced dramatically owing to the far higher TOC removal efficiency of BPA with 81.05 % within 60 min than original HCN (37.63 %). The photocatalytic reaction mechanism investigations demonstrate that h+, •O2− and •OH all take part in the degradation process of BPA and the importance order of h+ > •O2− > •OH. This work provides an innovative design philosophy for the assembly of photo-enzyme synergic catalytic system to effectively remove the organic pollutants in water.

Growth, optical and thermal properties of YbxSm1-xCa4O(BO3)3 crystals

YbxSm1-xCOB (x = 0.1, 0.2) crystals were grown by the Bridgman method for the first time. The purpose of this paper is to evaluate the application prospect of Yb:SmCOB crystal in quasi-parametric chirped pulse amplification (QPCPA) and frequency-doubling laser. The phase structure, thermal properties and optical properties of Yb:SmCOB were studied, and the density of states of SmCOB crystal was calculated by first-principles. The effective segregation coefficient Keff of Yb0.1Sm0.9COB and Yb0.2Sm0.8COB crystals are 0.89 and 0.88, respectively. The thermal diffusivity and thermal conductivity of Yb:SmCOB decrease with increasing temperature. The specific heat increases with the increase of temperature and eventually tends to be constant. The specific heat of Yb:SmCOB crystal is greater than 0.70 J/(g·K) at room temperature. The transmittance of Yb:SmCOB crystal reaches 87 % in the range of 500 ∼ 900 nm. With the increase of Yb3+ doping concentration, the UV absorption cut-off edge is red shifted. The frequency doubling emission peak of Yb:SmCOB crystal at 490 nm was measured by 980 nm laser. Yb:SmCOB has the characteristics of high transmittance and high specific heat, and has application potential in laser frequency doubling and QPCPA.

Experimental Research on the Influence of Repeated Overheating on the Thermal Diffusivity of the Inconel 718 Alloy

The Inconel 718 superalloy, a precipitation-hardenable material, is of particular interest for applications involving components operating under extreme conditions due to its excellent mechanical properties, high corrosion resistance at temperatures up to 700 °C, and good workability. At high temperatures, thermal transfer processes are crucial for temperature distribution across the component’s section, structural transformations, and variations in the alloy’s properties. The history of accidental overheating events is critical for the microstructure and properties of the alloy. Studies on thermal transfer in the Inconel 718 alloy available in the literature typically focus on the alloy in its as-delivered state. The experimental research presented in this paper examines the influence of repeated overheating history on the thermal diffusivity of the alloy.

Ameliorated Fick’s law algorithm based multi-threshold medical image segmentation

Medical image segmentation is a critical and demanding step in medical image processing, which provides a solid foundation for subsequent medical image data extraction and analysis. Multi-threshold image segmentation, one of the most commonly used and specialized image segmentation techniques, limits its application to medical images because it requires demanding computational performance and is difficult to produce satisfactory segmentation results. To overcome the above problems, an ameliorated Fick's law algorithm (MsFLA) for multi-threshold image segmentation is developed in this paper. First, an optimized sine–cosine strategy is introduced to extend the molecular diffusion process to alleviate the problem of easily falling into local optima, thus improving the convergence accuracy of the Fick's law algorithm (FLA). Secondly, the introduction of local minimal value avoidance enriches the individual molecular information and enhances the local search ability, thus improving computational accuracy. In addition, the optimal neighborhood learning strategy is added to ensure a more careful and reasonable reliance on the optimal solution, thus reducing the chance of convergence of a local solution. The efficient optimization capability of MsFLA is comprehensively validated by comparing MsFLA with the original FLA and other algorithms in 23 classical benchmark functions. Finally, MsFLA is applied to image segmentation of grayscale images of COVID-19 and brain and color images of Lung and Colon cancer histopathology by using Cross entropy to validate its segmentation capability. The experimental results show that the MsFLA obtains the best segmentation results in three medical image cases compared to other comparison algorithms, which indicates that MsFLA can effectively solve the multi-threshold medical image segmentation problem.Graphical abstract

Functional light diffusers based on hybrid CsPbBr3/SiO2 aero-framework structures for laser light illumination and conversion

The new generation of laser-based solid-state lighting (SSL) white light sources requires new material systems capable of withstanding, diffusing, and converting high intensity laser light. State-of-the-art systems use a blue light emitting diode or laser diode in combination with color conversion materials, such as yellow emitting Ce-doped phosphors or red and green emitting quantum dots (QD), to produce white light. However, for laser-based high-brightness illumination thermal management and uniform light diffusion are still major challenges in the quest to convert a highly focused laser beam into an efficient lighting solution. Here, we present a material system consisting of a highly open porous (> 99%) framework structure of hollow SiO2 microtubes. This framework structure enables efficient and uniform light distribution as well as ensuring good thermal management even at high laser powers of up to 5 W, while drastically reducing the speckle contrast. By further functionalizing the microtubes with halide perovskite QDs (SiO2@CsPbBr3 as model system) color conversion from UV to visible light is achieved. By depositing an ultrathin (~ 5.5 nm) film of poly(ethylene glycol dimethyl acrylate) (pEGDMA) via initiated chemical vapor deposition (iCVD), the luminescent stability of the QDs against moisture is enhanced. The demonstrated hybrid material system paves the way for the design of advanced and functional laser light diffusers and converters that can meet the challenges associated with laser-based SSL applications.Graphical

Synergistic reinforcement mechanisms of Cu/graphite composites with MAX phase Ti2AlN and ZrO2-B4C ceramics: Enhancements in mechanical, thermal, and tribological properties

In braking materials field, MAX phase has been introduced into Cu-based composite materials to address issues such as inadequate wetting between ceramic particles and the metal matrix. This study focuses on preparing Ti2AlN-ZrO2-B4C reinforced Cu-based materials via the powder metallurgy method, and investigates the effects and mechanisms of different Ti2AlN/ZrO2 ratios on the mechanical, thermal, and tribological properties of these materials. The addition of an appropriate amount of Ti2AlN (3 wt%) can enhance the densification and mechanical properties of Cu-based materials, as the diffusion of Al atoms promotes the sintering process. Similarly, the diffusion of Al also improves the thermal conductivity at grain boundaries, resulting in samples with higher Ti2AlN content exhibiting superior thermal diffusivity. When the Ti2AlN content reached 7 wt%, the material exhibited optimal hardness (43.35 ± 1.05 HBW), moderate shear strength (19.84 ± 1.86 MPa), as well as excellent high initial braking speed friction coefficient and stability. The reinforcement primarily arises from the diffusion bonding between Ti2AlN and Cu, leading to the formation of Cu-Ti compounds at the interface, which facilitates Ti2AlN in providing frictional force during the friction process and promotes the formation of a friction film due to the “pinning effect”. Additionally, the layered structure of Ti2AlN and the subsequent formation of amorphous Al2O3 after oxidation contributed to the enhancement of friction stability.

Thermophysical Properties' Enhancement of LiNO3-NaNO3-KNO3-NaNO2-KNO2 Mixed with SiO2/MgO Nanoparticles.

The aim of this study is to further enhance the thermal storage and heat transfer performances of a low-melting-point quinary salt. The eutectic salt was prepared using LiNO3, NaNO3, KNO3, NaNO2, and KNO2 as raw materials, followed by the doping of nano-SiO2 and nano-MgO into the base salt using a microwave-assisted method. The thermal properties of the samples were analyzed using a Synchronous Thermal Analyzer and a Laser Flash Apparatus. The co-doping of two types of nanoparticles was found to significantly enhance the specific heat capacity of the base salt. The maximum specific heat reached 2.36 J/(g·K), showing a 50.4% increase compared to the base salt. The thermal conductivity of molten salts can be affected by nanoparticles. An observed sample demonstrated a thermal diffusivity of 0.286 mm2/s, indicating a 19.2% improvement over the base salt, which may be attributed to enhanced phonon thermal efficiency. In addition, this study revealed that while interfacial thermal resistance can enhance specific heat capacity, it can also lead to a decrease in the thermal conductivity efficiency of materials. This work can offer insights and references for the enhancement of molten salt properties.

The Effects of Microstructure on the Thermophysical Properties of the K439B Ni-Based Superalloy

The thermophysical properties of superalloys are critical for the design, fabrication, and service of hot-end components in engines. In this work, the influence of microstructure on the thermophysical parameters including heat conductivity, thermal diffusivity, heat expansion coefficient, and specific heat capacity of the K439B superalloy, which is a prospective cast superalloy for engine casings, were investigated from 100 °C to 900 °C. It has been observed that these properties increase with temperature, especially between 700 °C and 800 °C, for alloys subjected to different heat treatment processes. When compared under the same temperature, these parameters decrease with an increase in the size and volume fraction of the γ′ phase in the alloys. Meanwhile, the interfaces between the γ/γ′ phase and the boundaries between dendrites also impeded the heat treatment. It can be concluded that among the alloys with different heat treatment process, the sequence 1160 °C/4 h + 1080 °C/4 h + 845 °C/20 h exhibited the most stable heat conductivity and lowest heat expansion coefficient, making it advantageous for high-temperature service.

Complete Dynamics from Ignition to Stabilization of a Lean Hydrogen Flame with Thickened Flame Model

Abstract In recent years, attention has been paid to hydrogen thanks to its carbon-free nature and its interesting characteristics as an energy vector. Despite the large number of numerical analyses regarding hydrocarbon combustion in all the steady and unsteady processes, few papers that cover all those aspects are available in the literature for hydrogen flames. Therefore, a numerical methodology to explore the complete ignition sequence from the spark release to the flame stabilization is validated on a single-sector hydrogen burner. In this context, a preliminary DNS investigation of laminar spherical expanding flames is performed using different diffusive transport models to isolate their impact. The present work, carried out within the European project HESTIA, investigates the atmospheric test rig installed at the Norwegian University of Science and Technology operating with a lean, perfectly premixed, hydrogen-air flame stabilized on a conical bluff body. Four simulations are performed adopting the Thickened Flame Model with an energy deposition strategy to assess the impact of preferential and thermal diffusion, as well as grid resolution, on flame dynamics. 3D flame structure visualization coupled with detailed PIV/OH-PLIF measurements allows the investigation of the key mechanisms involved during the ignition. The dynamic response of the flame through axial fluctuations once the ignition transient is concluded, is reconstructed by the numerical strategy employed. Although the overall behavior is almost unchanged by including or not thermal diffusion effects, their local impact on the flame is evident leading to a better agreement with experimental data.

Is it Time to Demolish Current Mathematics?

Current mathematics in 3D geometric space plus real time t as an external control is incomplete and misleading. The dream of theoretical physicists and mathematicians to demolish all current mathematics and replace it with a single universal numerical statistical law in 4D is now within reach. In this paper, we first focus on the introduction and definition of the proposed unitary 4D space. Next, we introduce and explain what we call the modern Laplacian theorem in 4D unit space. Finally, we explain some unexpected and striking numerical results such as measuring the speed of sound in air at 330 m/s and that of light at 3 E8 m/s. There is an inherent relationship between the speed of sound in air and the diffusivity of sound waves in the sound room, similar to the relationship between the speed of light in a vacuum and the thermal diffusivity of metals when they all live two in a 4D unit. space.

Contactless thermal diffusivity characterization of second order magnetocaloric materials under magnetic field using modulated photo-thermal radiometry method with very low power probe beam

The thermal diffusivity of magnetocaloric materials has a transition point at a given temperature that depends on the intensity of the applied magnetic field. Consequently, a fine temperature resolution on the material sample is needed to obtain an accurate determination of the thermal diffusivity variation with temperature. The coupling between the external and the internal fields has to be carefully mastered since the pertinent operating condition is fixed by the actual internal field which is not directly measurable and may be heavily affected by any element in contact with the sample. Therefore, contactless methods such as Photo-Thermal Radiometry (PTR) are privileged. The latter is based on a radiative excitation of the front face of a thin sample and the detection of the thermal effect on the opposite face. However, the powerful radiative source may significantly increase the sample temperature which is not suitable for caloric materials. In this work, a low power modulated PTR method is proposed to characterize second order magnetocaloric materials under magnetic field. It was compared to high energy thermo-flash PTR and validated on common materials such as steel and stainless steel, and then applied to gadolinium which is the reference magnetocaloric material for magnetic refrigeration and heat pumping study. The thermal diffusivity of gadolinium samples is measured in the 285.1 K to 305.1 K temperature range, including the magnetic transition temperature without and under an external magnetic flux density of 0.5 T in the 13 mm air gap of the permanent magnet magnetic circuit. The low power probe beam ensures a temperature stability with a negligible sample temperature fluctuation less than 0.05 K on the incident sample surface and less than 0.03 K on the measurement surface. The experimental results without magnetic field align with those using other methods including the magnetic transition temperatures determination. This low-power optical method proved its efficiency to characterize highly temperature dependent materials such as magnetocaloric materials sensitive to magnetic field. The data obtained partly fills the lack of information in the literature on excited gadolinium.

Precipitation behavior and performance evolution of cold-rolled cu-Ti-Fe alloy during heat treatment

The CuTi alloy is extensively utilized for its high strength, excellent elasticity, and processability. Heat treatment processes are crucial for affecting the microstructure and properties. The effects of different aging processes on the microstructure and properties of cold-rolled Cu-Ti-Fe alloy were investigated, and the heat treatment parameters were optimized. The results show that the cold-rolled Cu-Ti-Fe alloy exhibits excellent comprehensive performance at 450 °C for 2 h, with the hardness of 342.2 HV, the electrical conductivity of 16.1 % IACS, and the tensile strength of 1051 MPa. The aggregation of solute atoms occurs in the early stages of aging. The uniformly distributed β'-Cu4Ti phase precipitates at peak aging, which has a coherent relationship with the matrix. The precipitation of Ti atoms enhances the electrical conductivity of the alloy, and the movement of dislocations is prevented by precipitates, increasing the strength. During the over-aging stage, the precipitates transform into β-Cu4Ti phases, losing complete coherency with the matrix. The coarsening of precipitates leads to the softening of the Cu-Ti-Fe alloy. Theoretical calculation results indicate that the thermal diffusion ability of solute atoms is the strongest and precipitates completely when the alloy aged at 450 °C. The precipitation strengthening mechanism plays a significant role in improving the strength.

Marginal stability analyses for thermochemical convection and its implications for the dynamics of continental lithosphere and core–mantle boundary regions

SUMMARY Significant compositional differences may exist in the lithospheric mantle and above the core–mantle boundary (CMB) relative to the ambient mantle. The intrinsic density differences may affect the development of thermal boundary layer (TBL) instabilities associated with lithospheric delamination and formation of thermochemical plumes. In this study, we explored the instability of two-layer thermochemical fluid using two different techniques: marginal stability analysis with a propagator-matrix method and finite element modelling. We investigated both the instabilities in lithospheric mantle (i.e. lithospheric instability) and the mantle above the CMB (i.e. plume-forming instability) using a background temperature Tbg(z) with the TBL. For lithospheric instability, we found that two-layer fluid with free-slip boundary conditions mainly undergoes the same three different convective modes (i.e. two oscillatory convection modes and one layered convection regime) as that with no-slip boundary conditions reported in Jaupart et al. However, with free-slip boundary conditions, the transitions between these convection modes occur at larger values of buoyancy number B. Free-slip boundary conditions lead to smaller critical Rayleigh number Rac, but larger convective wavelength and oscillation frequency ωc, compared with those with no-slip boundary conditions. Our numerical modelling results demonstrate that Rac and ωc predicted from the classical marginal stability analyses using Tbg(z) with TBL temperature may have significant errors when the oscillatory period is comparable with or larger than the timescale of lithospheric thermal diffusion that causes Tbg(z) to vary with time significantly. In this case, using a more gently sloped background temperature profile ignoring the TBL temperature, the stability analysis predicts more accurate stability conditions, thus presenting an effective remedy to the stability analysis. For plume-forming instability, because of the reduced viscosity in the hot and compositionally dense bottom layer, the transition to the layered convection occurs at significantly smaller B values, and in the oscillatory convection regime, Rac is larger but ωc is smaller, compared with those for lithospheric instability. Finally, our study provides a successful benchmark of numerical models of thermochemical convection by comparing Rac and ωc from numerical models with those from the marginal stability analysis.

Systemic Codelivery of Thymoquinone and Doxorubicin by Targeted Mesoporous Silica Nanoparticle Sensitizes Doxorubicin-Resistant Breast Cancer by Interfering between the MDR1/P-gp and miR 298 Crosstalk.

Multi drug resistance (MDR) in breast carcinoma still poses a significant impairment to successful chemotherapy. As the arsenal of anticancer agents increases with improved preclinical methods, the growth of therapeutic drug combinations is now unprecedented. The malignancies addressed by mono drugs often fail to limit cancer progression, resulting in resistant cancer, thereby offering combinatorial therapies a terrific edge over monodrug regimes. However, the selection of drug combinations required enough preliminary evidence for their synergistic effect. The fundamental mechanisms of MDR to chemotherapeutics are associated with the overexpression of membrane efflux pumps, alternations in drug targets, and increased drug metabolism. Unfortunately, it is very difficult for drugs to overcome resistance produced on their own or by another different drug action. In this context, herein, we report a simple delivery system for coencapsulation and intracellular codelivery of dual-drug thymoquinone (TQ) and doxorubicin (DOX) to resensitize DOX-resistant MDA MB231 cell line (231 R). The 231 R cell line developed in our lab showed an enhanced expression of the ATP-binding cassette (ABC) transporters P-gp1/MDR-1 and a declined miR-298 expression. The present delivery system is based on amine-functionalized mesoporous silica nanoparticles (MSNs), in which the side chain amine functional group was used to react with the carbonyl group of TQ, which acts as a pro-drug system (TQ-MSN) to release TQ and DOX simultaneously. DOX was encapsulated later into the above TQ-MSN by a simple diffusion method. The drugs containing MSNs were further coated with a hyaluronic acid-conjugated PEG-PLGA polymer (HA@TQ-DOX-MSN). This simple nanostrategy interferes with the MDR-1/miR-298 cross-talk, thereby allowing a significant reduction in drug efflux from the cell and highlighting a promising nanotechnology-based combinatorial delivery approach in managing breast cancer chemoresistance.

Development and Validation of a One‐Dimensional Finite Difference Simulation Scheme for Polymer Laser Powder Bed Fusion with Application to the Effect of the Inter Layer Time

The division of the polymer laser powder bed fusion process polymers (PBF‐LB/P) into temporal regimes originating from laser motion, thermal diffusion, viscous flow, crystallization kinetics, and powder application is exploited by considering only the building direction. The reduction of dimensionality enables fast simulations which are used to investigate the influence of the inter layer time on the final part density. Numerical simulation results are validated by experiments using polyamide 12 (PA 12) with good agreement in terms of part density. It is shown that an inter layer time of 90 s leads to nearly dense PA 12 parts while a time of 45 s leads to less dense parts. The cooling effect of the applied powder is identified as a cause for insufficient densification of the previous layer. The simulation tool is quantitatively validated against experimental results for the surface temperature of PA 12 as function of scan speed and hatch distance, for the melt pool depth of polyamide 6 as function of scan speed and for the melt pool depth of polyetherketoneketone as function of laser power. The presented simulation method enables rapid process parameter adjustment for new polymer materials in the PBF‐LB/P process.

Scalable imaging-free spatial genomics through computational reconstruction.

Tissue organization arises from the coordinated molecular programs of cells. Spatial genomics maps cells and their molecular programs within the spatial context of tissues. However, current methods measure spatial information through imaging or direct registration, which often require specialized equipment and are limited in scale. Here, we developed an imaging-free spatial transcriptomics method that uses molecular diffusion patterns to computationally reconstruct spatial data. To do so, we utilize a simple experimental protocol on two dimensional barcode arrays to establish an interaction network between barcodes via molecular diffusion. Sequencing these interactions generates a high dimensional matrix of interactions between different spatial barcodes. Then, we perform dimensionality reduction to regenerate a two-dimensional manifold, which represents the spatial locations of the barcode arrays. Surprisingly, we found that the UMAP algorithm, with minimal modifications can faithfully successfully reconstruct the arrays. We demonstrated that this method is compatible with capture array based spatial transcriptomics/genomics methods, Slide-seq and Slide-tags, with high fidelity. We systematically explore the fidelity of the reconstruction through comparisons with experimentally derived ground truth data, and demonstrate that reconstruction generates high quality spatial genomics data. We also scaled this technique to reconstruct high-resolution spatial information over areas up to 1.2 centimeters. This computational reconstruction method effectively converts spatial genomics measurements to molecular biology, enabling spatial transcriptomics with high accessibility, and scalability.

Highly efficient multi-layer flexible heatsink for wearable thermoelectric cooling

Flexible thermoelectric cooler (fTEC), which interfaces well with curved human body surface and provides cooling functions, is an emerging candidate for personal thermal management and non-hospitalized medical treatment. Achieving efficient and long-term cooling performance of TEC requires high thermal conductivity and heat diffusion of the hot side, which has yet to achieve. In this study, we design and fabricate a highly thermally conductive and flexible heatsink with a multi-layered structure especially for wearable TEC wristband, which obtains a large temperature drop (8.8 °C) for imitated on-body test and the maxim 13.1 °C temperature decrease in air. Here, we demonstrate that a well-designed functional composite layer, including phase change material, thermally conductive fillers and metal foam, can establish an effective equilibration among cooling performance, thermal management capacity and mechanical property. Particularly, the heatsink with highly thermal conductive skeleton (k ∼ 2.7 W/mK) and effective heat dissipating fins can significantly improve heat conduction and dissipation, which improve the cooling performance by more than 55 %. With the help of theoretical simulation, we propose a promising strategy for heat management on thermoelectric device through a flexible multi-layered structure, paving the way for achieving practical applications of wearable thermoelectric coolers for personal thermal regulation or cooling therapy.

Molecular insights into the performance of promoters for carbon dioxide hydrate

Hydrate-based CO2 storage is a cost-effective and environmentally friendly approach to reduce carbon emission, and the addition of hydrate promoters has shown a promising avenue for enhancing CO2 hydrate formation. In this work, the promotion mechanism and promotion performance of five different hydrate promoters (denoted as DIOX, CP, THF, THP, and CH) were investigated and compared by first-principles calculations and molecular dynamics simulations. The results show that the hydrate promoters prefer to singly occupy 51264 cages of the sII hydrate, and CO2 molecules can singly occupy 512 cage or multiply occupy 51264 cages. The cohesive energy density indicates that the optimum CO2 storage capacity can reach up to ∼28 wt%. The stabilization effects of hydrate promoters on the hydrate stability should follow the order of CP > CH > DIOX > THF ≈ THP. The hydrate promoters can increase the water-water interactions, and the molecular diffusivity shows that the dynamic stability of the hydrates is THP ≈ CH > CP > DIOX > THF. Further, the hydrate promoters can accelerate the hydrate formation kinetics, which reduce the induction time and increase the nucleation and growth process.

Theory and Design of Audio Rooms: Physical Formulation

The time-dependent statistical chains of transition matrix B are successfully used to calculate the reverberation time TR and sound energy density field in audio rooms. This is a real breakthrough in the search for a statistical derivation of Sabines' imperial theory which has never been rigorously proven since 1898. Additionally, we provide proper design and calculations of sound wave energy density in audio rooms via two cuboid room examples. We provide proper design and calculations of sound wave energy density in audio rooms via two cuboid room examples. We also propose some general statistical rules that can be applied to statistical problems of physical phenomena in general, such as the thermal diffusion equation and the theory of sound waves in audio rooms. We also give a description of the theory and design of what we call comfortable sound rooms based on the purpose of their use via well-defined measurables. Finally, we provide a consistent derivation of Sabines' theory without using Ls=4V/A or any other statistical assumptions.