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The Chinese national standard for paper ash measurement cannot meet the requirements for accurate and rapid ash measurement in actual production and scientific research because of the long measuring time, tedious procedures, and large human error. This paper reviews some worldwide devices and methods for rapid measurement of paper ash, including ceramic fiber muffle furnace, microwave muffle furnace, the addition of ash adjuvant, dry samples method, direct combustion of paper samples, oxygen-enriched combustion method, chemical analysis method, and ray method, etc. The differences and relationships are identified among these devices and methods. By comparing the different ash measurement methods, the rapid ash analyzer based on X-ray technology has the obvious advantages of short measuring time and small error. Lastly, the present situation and the development potential of these devices and methods are discussed in this review.

There is fragmentary knowledge of iron ore sources exploited in the past for many regions including the Southern Levant. This missing information has the potential to shed light on political, economic, craft-production, and trading patterns of past societies. This paper presents the results of smelting experiments performed in graphite crucibles and a muffle furnace, using 14 iron ore samples from the Southern Levant, in an attempt to determine their suitability for smelting using ancient techniques. A range of analytical techniques, including optical and electron microscopy, Fourier-transform infrared spectroscopy, X-ray powder diffraction, and portable X-ray fluorescence were used to comparatively investigate the mineralogy and composition of the precursor iron ores and their smelting products: Iron bloom and slag. Several parameters attesting to the ability of a given ore to be successfully reduced and consolidated into a solid metal mass were quantified. The generated results highlight the significance of a ‘correct balance’ between iron oxides and other major elements in the smelting system in order to form fluid slag and a well-consolidated bloom. These data contribute to the understanding of factors, potentially influencing choices of iron ore exploitation by past human societies in the Southern Levant.

To fabricate an industrial and highly efficient super-hydrophobic brass surface, annealed H59 brass samples have here been textured by using a 1064 nm wavelength nanosecond fiber laser. The effects of different laser parameters (such as laser fluence, scanning speed, and repetition frequency), on the translation to super-hydrophobic surfaces, have been of special interest to study. As a result of these studies, hydrophobic properties, with larger water contact angles (WCA), were observed to appear faster than for samples that had not been heat-treated (after an evolution time of 4 days). This wettability transition, as well as the evolution of surface texture and nanograins, were caused by thermal annealing treatments, in combination with laser texturing. At first, the H59 brass samples were annealed in a Muffle furnace at temperatures of 350 °C, 600 °C, and 800 °C. As a result of these treatments, there were rapid formations of coarse surface morphologies, containing particles of both micro/nano-level dimensions, as well as enlarged distances between the laser-induced grooves. A large number of nanograins were formed on the brass metal surfaces, onto which an increased number of exceedingly small nanoparticles were attached. This combination of fine nanoparticles, with a scattered distribution of nanograins, created a hierarchic Lotus leaf-like morphology containing both micro-and nanostructured material (i.e., micro/nanostructured material). Furthermore, the distances between the nano-clusters and the size of nano-grains were observed, analyzed, and strongly coupled to the wettability transition time. Hence, the formation and evolution of functional groups on the brass surfaces were influenced by the micro/nanostructure formations on the surfaces. As a direct consequence, the surface energies became reduced, which affected the speed of the wettability transition—which became enhanced. The micro/nanostructures on the H59 brass surfaces were analyzed by using Field Emission Scanning Electron Microscopy (FESEM). The chemical compositions of these surfaces were characterized by using an Energy Dispersive Analysis System (EDS). In addition to the wettability, the surface energy was thereby analyzed with respect to the different surface micro/nanostructures as well as to the roughness characteristics. This study has provided a facile method (with an experimental proof thereof) by which it is possible to construct textured H59 brass surfaces with tunable wetting behaviors. It is also expected that these results will effectively extend the industrial applications of brass material.

Numerical simulation has been widely used to study the temperature field characteristics of muffle sintering, compensating for the limitations of experiments in obtaining temperature data for high-temperature muffle furnaces. We established a numerical model of the transient temperature field of a high-entropy alloys workpiece in a muffle furnace and simulated it. The simulation results are in agreement with the measured results. The muffle furnace structure’s influence on the workpiece’s temperature uniformity during and after the sintering process is further discussed. The results show that increasing the height of the workpiece can reduce the heat loss and heat absorption of the workpiece during the sintering process. The overall temperature and temperature uniformity of the workpiece were effectively improved by raising the height of the workpiece through the use of shims with a moderate height. The layout of the distance between the heating tubes also affects the temperature uniformity of the workpiece. Reducing the tube spacing causes a small increase in the average temperature of the workpiece, but increasing the tube spacing results in a more uniform temperature field of the workpiece.

The present paper examines the failure mechanism of the coating system of Al 2 O 3 –ZrO 2 ·5CaO applied on a Cast iron substrate. The atmospheric plasma spray coating technique was used for coating. A muffle furnace was used to heat the sample to 600 ± 2 °C followed by ambient cooling. Both the heating and cooling cycles were maintained for 30 min. Results were compared between the as-sprayed coated specimen and the post thermal cyclic test specimen. It has been noticed that normal stresses developed due to the formation of thermally grown oxide at the interface of the top/bond coat and constitutes the weakest link in the coating system. Also, differential porosity at the interface led the moisture to penetrate from the top coat to the bottom coat. Thus, a thermochemical process occurred below the bond coat, leading to the formation of oxides and made the top coat gradually more brittle during the thermal cyclic process.

Herein, a novel nanocomposite, namely, Zn-modified CeO 2 @biochar (Zn/CeO 2 @BC), is synthesized via facile one-step sol-precipitation to study its photocatalytic activity towards the removal of methylene blue dye. Firstly, Zn/Ce(OH) 4 @biochar was precipitated by adding sodium hydroxide to cerium salt precursor; then, the composite was calcined in a muffle furnace to convert Ce(OH) 4 into CeO 2 . The crystallite structure, topographical and morphological properties, chemical compositions, and specific surface area of the synthesized nanocomposite are characterized by XRD, SEM, TEM, XPS, EDS, and BET analysis. The nearly spherical Zn/CeO 2 @BC nanocomposite has an average particle size of 27.05 nm and a specific surface area of 141.59 m 2 /g. All the tests showed the agglomeration of Zn nanoparticles over the CeO 2 @biochar matrix. The synthesized nanocomposite showed remarkable photocatalytic activity towards removing methylene blue, an organic dye commonly found in industrial effluents. The kinetics and mechanism of Fenton-activated dye degradation were studied. The nanocomposite exhibited the highest degradation efficiency of 98.24% under direct solar irradiation of 90 min, at an optimum dosage of 0.2 g l −1 catalyst and 10 ppm dye concentration, in the presence of 25% (V/V) 0.2 ml (4 µl/ml) hydrogen peroxide. The hydroxyl radical generated from H 2 O 2 during the photo-Fenton reaction process was attributed to the nanocomposite’s improved photodegradation performance. The degradation process followed pseudo-first-order kinetics having a rate constant ( k ) value of 0.0274 min −1 .

Base metal sulfides (Fe–Ni–Cu–S) are ubiquitous phases in mantle and subduction-related lithologies. Sulfides in the mantle often melt incongruently, which leads to the production of a Cu–Ni-rich sulfide melt and leaves a solid residue called monosulfide solid solution (mss). However, the persistence of crystalline sulfide phases like mss in the Earth’s mantle at higher temperatures and pressures deep within the Earth has long been up for debate, as the presence of both mss and sulfide melt in mantle rocks implies the fractionation of chalcophile elements during mantle melting. Recent studies have shown that the average mantle sulfide (45 wt.% Fe, 16 wt.% Ni, 1 wt.% Cu, and 38 wt.% S), is fully molten at average mantle potential temperatures (1300–1400 ∘C) up to 8 GPa (ca. 240 km). However, sulfide inclusions found in diamonds show a broad compositional spectrum, ranging from Ni-poor and Fe-rich (eclogitic), to Ni-rich and Fe-poor sulfides (peridotitic), with their Cu contents being generally low. The wide compositional variety of diamond-hosted sulfide inclusions raises the possibility that results on the melting properties obtained from this average mantle sulfide compositional may not reflect that found in those inclusions. As such, further investigation of the melting properties of sulfides from a wide compositional range is necessary. Here, we present the results of an experimental study where the melting properties of typical sulfide compositions found in diamond inclusions associated with eclogites and peridotites have been determined. Experiments have been carried out between 0.1 MPa and 14 GPa, and between 920 and 1590 ∘C, on box muffle furnaces, end-loaded piston cylinder, and multi-anvil apparatuses. Results show that solid mss in Fe-rich, Ni-poor sulfide inclusions associated with eclogites persist to higher pressures and temperatures compared to their less-refractory, more Ni-rich peridotitic counterparts to the depth of the mantle transition zone (410 km depth). Our results have implications for the recycling of chalcophile elements during subduction-related processes and the entrapment of sulfides in diamonds.

In this research work, aluminum substituted Ni-Co ferrite nanoparticles have been produced by a simple and cost-effective method, i.e., sol–gel auto-combustion. Synthesized nanoparticles were annealed in a muffle furnace at 600°C for 3 h before characterization. The x-ray diffraction patterns revealed that the ferrite nanoparticles grew preferentially along the (311) plane and exhibit face centered cubic structure. The crystallite size of nanoparticles (14 to 17 nm) was estimated by Scherrer’s relation. The effect of aluminum substitution on structural parameters of ferrite nanoparticles, such as lattice constant and stacking faults, have been studied. Structural analysis revealed that the lattice constant of the nanoparticles decreases as a function of aluminum content. The Fourier transform infrared spectroscopy confirmed the spinal ferrite crystal structure of synthesized aluminum substituted Ni-Co ferrite nanoparticles. The surface morphology observed through scanning electron microscopy depicts the growth and distribution of nanograins with uniform size with in the samples. Dielectric properties investigated through impedance analyzer spectroscopy revealed that aluminum substituted Ni-Co ferrite nanoparticles demonstrated the high conductivity along with potential dielectric properties. These aluminum substituted Ni-Co ferrite nanoparticles would have possible applications in high storage memory and microwave devices.

To develop high-efficient biochar adsorbents, the effects and mechanisms of oxidant modification and acid modification on Cd(II) adsorption by rice straw biochar were investigated. Three rice straws from Langxi in Anhui Province, Yingtan in Jiangxi Province, and Lianyungang in Jiangsu Province were collected to prepare biochars by anaerobic pyrolysis in a muffle furnace. Rice straw biochars were modified by 15% H 2 O 2 and 1:1 HNO 3 /H 2 SO 4 mixed acid, respectively, to obtain modified biochars. The untreated rice straw biochar and HCl-treated rice straw biochar with carbonate removed were used as controls. The functional groups on the surfaces of the biochars were qualitatively and quantitatively determined by Fourier transform infrared spectra and Boehm titration, respectively. The adsorption and desorption of Cd(II) onto and from the biochars and modified biochars were measured under various pH conditions. The results showed that oxidant modification with 15% H 2 O 2 and acid modification with 1:1 HNO 3 /H 2 SO 4 significantly increased the number of carboxyl functional groups on the surfaces of the biochars, and acid modification was more effective than oxidant modification in amplifying carboxyl functional groups on the surfaces of the biochars. The increase of surface functional groups effectively enhanced the specific adsorption of Cd(II) on the modified biochars. Therefore, both oxidant modification and acid modification enhanced the adsorption of Cd(II) on the biochars through increasing functional groups on the surfaces of the biochars.

High-energy microwaves and lasers are applied to assist mechanical rock breaking due to their advantages in rapid thermal damage to hard rocks. However, the quantitative evaluation of rock damage under microwave and laser irradiation has always been a difficult problem. In this study, a multiscale and multiphysics numerical modelling approach is developed to quantitatively describe rock thermal damage under microwave and laser irradiation. By coupling the concept of the grain-based model (GBM), electromagnetic-thermal solution of COMSOL, and thermo-mechanical fracture simulation of the four-dimensional lattice spring model (4D-LSM), a fine-grained multiphysics numerical model is developed to quantitatively investigate rock damage during muffle furnace heating and microwave heating. Through a full comparison between the fine-grained numerical simulations and experimental results, we concluded that the rock thermal damage functions of these two heating methods are dominantly influenced by the meso-structure and mineral composition of the rock rather than the temperature gradient. Moreover, the limitation of temperature measurement is the most likely reason for the experimentally observed difference in rock thermal damage between muffle furnace heating and microwave heating. For a coarse-grained multiphysics numerical model for larger scale analysis, the influences of meso-structure and mineral composition on the rock thermal damage can be considered by introducing thermal damage functions. Our numerical study indicates that rock thermal damage functions obtained by using experimental data from muffle furnace heating can be used for microwave or laser irradiation, and a calibration method using a weight function with a single correction coefficient is developed to further address the difference in experimental conditions, the change in simulated scale, and the discreteness of used experimental data. Our coarse-grained multiphysics numerical model with thermal damage functions calibrated by data from a single experiment is verified to be able to quantitatively predict the experimentally observed microwave-induced and laser-induced rock damage. This study provides the possibility and methodology to reuse experimental data for rock thermal damage by muffle furnace heating in the analysis of rock damage under microwave and laser irradiation.HighlightsRock thermal damage during muffle furnace heating and microwave heating is quantitatively investigated by using a fine-grained multiphysics numerical model.The limitation of temperature measurement is the most likely reason for the experimentally observed difference in rock thermal damage between muffle furnace heating and microwave heating.A calibration method using a weight function with a single correction coefficient is developed to obtain thermal damage functions for microwave or laser irradiation from thermal damage functions for muffle furnace heating.A coarse-grained multiphysics numerical model with thermal damage functions calibrated by data from a single experiment is verified to be able to quantitatively predict experimentally observed rock thermal damage under microwave and laser irradiation.