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Identification of an individual artist’s touch on paintings is studied using surface metrology. Paintings’ topographies were measured using focus variation and stitching, creating 13 × 13 mm maps with 1 μm sampling intervals, and 169 megapixels, with a 10X objective lens. Topographic characterization parameters were analyzed for their ability to differentiate different painters’ renderings. Statistical treatments from data mining were used to discriminate, by optimization, multiscale topographic signatures characterized by a multitude of areal texture parameters. It appears that a fractal dimension can define 3 characteristic scale ranges. One from 3 to 70 μm corresponds to brushstroke details. Another, from 70 to 700 μm, corresponds to the topography of the material of the canvas fabric. Finally, scales greater than 700 μm correspond to undulations of the canvas. For scales less than 50 μm, the fractal structure of the topography left by brushstrokes follows a power law characterized by the slopes of the topography. The topography of the clouds painted on the canvas has an Sdq (topographic slopes) increasing with the clarity of the clouds at scales of 3–500 μm. According to the Torrance-Sparrow theory, the higher the Sdq, the more diffuse the light on the surface. The painter therefore wanted to show, by his brushstroke, that the light clouds diffuse more light giving an impression of local brightness. This study is confirmed by the analysis of the painting of Max Savy, a French painter from Carcassonne (1918–2009), which was measured with a white light interferometer Zygo NewView 7300, a X100 objective lens giving a 517 μm × 517 μm stitched surface, with a sampling interval of 0.109 μm. The box-counting method for estimating the fractal dimension of the topography of an oil painting appears optimal by the fact that it morphologically integrates scale variations of the local slopes of the surface morphology. This method thus characterizes the multiscale aspects, as well as the scale changes, of the topography.

We report the results of calculations and experimental studies of specific energy characteristics of a supersonic cw chemical HF laser with a flat nozzle block corresponding to the nozzle – nozzle reagent mixing scheme, in which catalytic decomposition products of hydrazine N2H4 (H2 + N2 + NH3) are used as a secondary fuel. As a result of experiments with cold (300 K) model mixtures, the specific energy extraction of the laser is found to decrease in this case by 43 % compared with the laser utilising pure hydrogen. The calculations show that the main reason for a decrease in the specific energy of the laser is an increase in the temperature in the mixing zone of the oxidising gas and secondary fuel jets. A strong effect of ammonia is revealed. Taking into account the actual heating of the products (up to 1000 K) during the catalytic decomposition of N2H4 allows the level of specific energy extraction from the laser to approach that of energy extraction from the laser operated on pure hydrogen by 13 %, which will lead to a decrease in the specific energy extraction by only 30 % in the absence of NH3 decomposition products.

Objective. High-density surface electromyography (HD-sEMG) allows the reliable identification of individual motor unit (MU) action potentials. Despite the accuracy in decomposition, there is a large variability in the number of identified MUs across individuals and exerted forces. Here we present a systematic investigation of the anatomical and neural factors that determine this variability. Approach. We investigated factors of influence on HD-sEMG decomposition, such as synchronization of MU discharges, distribution of MU territories, muscle-electrode distance (MED—subcutaneous adipose tissue thickness), maximum anatomical cross-sectional area (ACSAmax), and fiber cross-sectional area. For this purpose, we recorded HD-sEMG signals, ultrasound and magnetic resonance images, and took a muscle biopsy from the biceps brachii muscle from 30 male participants drawn from two groups to ensure variability within the factors—untrained-controls (UT = 14) and strength-trained individuals (ST = 16). Participants performed isometric ramp contractions with elbow flexors (at 15%, 35%, 50% and 70% maximum voluntary torque—MVT). We assessed the correlation between the number of accurately detected MUs by HD-sEMG decomposition and each measured parameter, for each target force level. Multiple regression analysis was then applied. Main results. ST subjects showed lower MED (UT = 5.1 ± 1.4 mm; ST = 3.8 ± 0.8 mm) and a greater number of identified MUs (UT: 21.3 ± 10.2 vs ST: 29.2 ± 11.8 MUs/subject across all force levels). The entire cohort showed a negative correlation between MED and the number of identified MUs at low forces (r = −0.6, p = 0.002 at 15% MVT). Moreover, the number of identified MUs was positively correlated to the distribution of MU territories (r = 0.56, p = 0.01) and ACSAmax (r = 0.48, p = 0.03) at 15% MVT. By accounting for all anatomical parameters, we were able to partly predict the number of decomposed MUs at low but not at high forces. Significance. Our results confirmed the influence of subcutaneous tissue on the quality of HD-sEMG signals and demonstrated that MU spatial distribution and ACSAmax are also relevant parameters of influence for current decomposition algorithms.

In recent years, Chinese power enterprises have adopted SF6/N2 to replace SF6 gas in transmission electrical equipment. In this paper, an experimental platform was set up to simulate the local overheating fault of gas insulated electrical equipment. The relationship between the decomposition products of SF6/N2 gas and temperature, experimental time, gas pressure and SF6 content was studied. The results showed that the main products of SF6/N2 gas decomposition were SO2, SO2F2, N2O, C2F6, COS, CS2 and CF4. The content of SO2 increased nonlinearly with the increase of temperature, experimental time, gas pressure and SF6 content. However, the contents of SO2F2, N2O, C2F6, COS, CS2 and CF4 decreased first and remained unchanged with the increase of gas pressure, and increased with the increase of temperature, experimental time and SF6 content. And C element in metal also affected the type and quantity of gas products.

The decomposition of phenol and 4-chlorophenol by underwater pulsed discharge has been examined. The addition of hydrogen peroxide improved the decomposition rate of phenol by about 2.5 times and that of 4-chlorophenol by about 1.5 times. Analysis using a fluorescent probe suggested that the addition of hydrogen peroxide enhanced the production of hydroxyl radicals by about 3 times. We have also examined the effect of using microbubbles on the decomposition of phenol. The use of only microbubbles resulted in a slight increase of the decomposition rate, while the use of both microbubbles and hydrogen peroxide led to a remarkable enhancement of the decomposition rate by about 3.5 times with the conversion of phenol reaching 70% at discharge time of 3 h, which corresponded to the energy yield of 4.39 × 10–9 mol J−1.

As peatland ecosystems were formed from layered partially decomposed plant biomass, they were considered more vulnerable to fire, especially during extreme drought season. Woody debris accumulation in the field may increase the risk of peatland fire. In order to minimize the chance of repeated fire, an initial study on woody debris decomposition by employing a consortium of wood-decay microbes (consists of Scedosporium apiospermum, Pycnoporus sp., Pycnoporus sanguineus, and unidentified cellulolytic bacterial isolate) was conducted. Series of experiments of in vitro-, semi-controlled-, and field- conditions were carried out. After 12-weeks of incubation, the in vitro trial showed that all treatments on mineral-soil basal media were colonized by fungal mycelia, including the control. Meanwhile, the treatments on peat soil seem less supportive for fungal growth since only six out of ten treatments have been colonized by fungal mycelia. In semi-controlled conditions, effects of microbial inoculation showed questionable results as the trials were randomly occupied by Schizophylum commune, which was not included in the microbial inoculants. Un-clear effects of the microbial inoculants were also observed on the field trial as no significant difference of dry-weight loss between the inoculated woody logs and the un-inoculated control. Further comprehensive studies to reduce woody debris in peatland areas are required.

The traditional alkali decomposition process and equipment of tungsten ore are limited by the situation that the grade of tungsten ore resources is decreasingy and the impurity content is getting higher and higher. A set of high-efficiency alkali decomposition process equipment of tungsten ore based on mechanical strengthening is researched and developed in this paper. Fourteen groups of mechanical strengthening decomposition tests were carried out on three particle sizes of ore samples. which verifies the feasibility and reliability of strengthening the alkali decomposition of tungsten ore by the test prototype.

Plasmas interacting with liquid microdroplets are gaining momentum due to their ability to significantly enhance the reactivity transfer from the gas phase plasma to the liquid. This is, for example, critically important for efficiently decomposing organic pollutants in water. In this contribution, the role of ⋅OH as well as non-⋅OH-driven chemistry initiated by the activation of small water microdroplets in a controlled environment by diffuse RF glow discharge in He with different gas admixtures (Ar, O2 and humidified He) at atmospheric pressure is quantified. The effect of short-lived radicals such as O⋅ and H⋅ atoms, singlet delta oxygen (O2(a 1Δg)), O3 and metastable atoms of He and Ar, besides ⋅OH radicals, on the decomposition of formate dissolved in droplets was analyzed using detailed plasma diagnostics, droplet characterization and ex situ chemical analysis of the treated droplets. The formate decomposition increased with increasing droplet residence time in the plasma, with ∼70% decomposition occurring within ∼15 ms of the plasma treatment time. The formate oxidation in the droplets is shown to be limited by the gas phase ⋅OH flux at lower H2O concentrations with a significant enhancement in the formate decomposition at the lowest water concentration, attributed to e−/ion-induced reactions. However, the oxidation is diffusion limited in the liquid phase at higher gaseous ⋅OH concentrations. The formate decomposition in He/O2 plasma was similar, although with an order of magnitude higher O⋅ radical density than the ⋅OH density in the corresponding He/H2O plasma. Using a one-dimensional reaction–diffusion model, we showed that O2(a 1Δg) and O3 did not play a significant role and the decomposition was due to O⋅, and possibly ⋅OH generated in the vapor containing droplet-plasma boundary layer.

Asbestos is one of the materials causing ecological stress. Due to its health harmfulness, an effective, ecological, and economic decomposition is highly desirable. One of the decomposition possibilities is a chemical decomposition, which could compete with commonly used thermal decomposition. The chemical decomposition can be accomplished both with the use of pure chemicals and waste chemicals from production technologies. This work deals with the use of technological wastes containing hydrofluoric acid or fluorides. Fluorides release hydrofluoric acid in the acid medium, which acts as the main decomposition medium. The source of fluorides was waste from the glass and metallic material industry. The efficiency of degradation processes was studied by mass analysis. Materials and decomposition products were characterized by X-ray powder diffraction.

The type and content of SF6 decomposition products are directly related to the type, location and degree of fault. Based on the analysis of the abnormal SF6 gas decomposition product content and discharge type of 126kV Porcelain Column type circuit breaker, the potential fault of the circuit breaker is judged to be suspension potential discharge fault. After disassembling the circuit breaker, it is found that the abnormal phase of the insulation rod is deformed, the pin become thin, and there are solid decomposition products, the sulfides and fluoride, which are mainly composed of iron, aluminum, chromium and manganese, further confirm that the potential fault of the circuit breaker is suspension potential discharge fault. The forming process and reaction mechanism of the suspended potential discharge fault are analyzed. Once the fault occurs, its function will promote the development of the fault. The influence of the suspension potential discharge fault on the performance of the circuit breaker is also analyzed. When the suspension potential discharge fault exists, it will cause the abnormality and even affect the normal operation of the circuit breake.

Partial over-thermal fault (POF) may occur during operation of SF6 gas insulated equipment, which will cause SF6 to decompose and threaten the safety of equipment and stable operation of power grid. The decomposition of SF6 is closely related to the residual O2 inside the equipment. The decomposition mechanism of SF6 under the action of O2 needs to be studied in depth but there is still a lack of a force field to describe it. This paper first establishes a reactive force field (ReaxFF) that can describe the microscopic reaction process of SF6 and O2 coexisting systems. Using the force field, a series of molecular dynamics (MD) simulations are performed to explore the effect of O2 on the over-thermal decomposition of SF6. First, the main chemical reactions affecting the formation of the characteristic products were obtained. Second, the decomposition process of SF6 and O2 with different proportions is studied, and the kinetic process of reactions are observed, which simulates the changes in quantity of the major products including SOF4, SOF3, SOF2, SO2F2, SOF and SO2. In addition, transition state theory is used to study the changes in energy and molecular structure during the reaction. Synthesizing the simulation results, the mechanism of O2 on the over-thermal decomposition of SF6 is analysed. The work advances understanding the mechanism of over-thermal failure of gas insulated equipment.

For binary compounds of Sc-N, the stable structures and stoichiometries were studied from ambient condition to high pressure of 100 GPa, adopting CALYPSO method. The newly predictedP21/c-ScN5compound was more energetically stable under high pressureP= 62 GPa comparing with the three previously reported phases ofP1-ScN5,Cm-ScN5andC2/m-ScN5. Furthermore, the high-pressure phase ofP21/c-ScN5was dynamically stable at ambient condition, so the ambient-pressure recovery is possible. In this paper, the study suggested that the energetic polynitrides can be obtained in transition metal nitrides under high pressure. And we identified one novel 3D extended puckered poly-nitrogen network in theP21/c-ScN5structure, which is similar to theC2/m-ScN5. The decomposition ofP21/c-ScN5to ScN and N2under ambient pressure was estimated to release 5.02 eV energy per formula unit (f.u.), corresponding to 4.19 kJ g-1in energy density, which was expected to be highly exothermic. The present results can conduce to obtain more polynitrogen forms and theoretically encourages experimental discovery in these promising materials.

In this paper, Box-Behnken response face model was used to establish the decomposition rate model of fungi. Based on the single factor simulation test data in the literature, this paper uses the Design-Expert 8, aiming at the peripheral range value of single factor optimization results, the orthogonal rotation combination experiment of multiple factors was designed to obtain the response surface regression model of fungi decomposition rate and temperature, time, quantity, population proportion and other factors, and to solve the optimal parameter combination; on the other hand, according to the research data of the title, taking the humidity tolerance as the link, the relationship function of fungi decomposition rate and growth rate, humidity tolerance was established by using MATLAB. Combining the two models, the decomposition rate model under the interaction of multiple fungi was established. The main factors affecting the decomposition rate of fungi were found from different angles by two methods, and different fungi were organically combined by growth rate and moisture resistance.

Temperature characteristics, stages and thermal effects of the processes occurring during the thermolysis of TOKEM-320Y anion-exchange resin in an atmosphere of air were determined by differential thermal analysis. The activation energies and the orders of reactions of thermal decomposition of the resin were calculated by the Kissinger and Metzger-Horowitz methods using the TG curves obtained at different heating rates of the resin. Models are proposed that most accurately describe the decomposition of TOKEM-320Y in air in the temperature range 25–800 °C.

This work is devoted to the preparation of microfiltration ceramic tubular membranes based on α-Al2O3 with deposited catalytically active layers for use in wastewater treatment processes. Cobalt and manganese oxides were used as the material of the catalytically active layer; deposition was carried out using a mixture of aggregative stable aqueous dispersions of Co3O4 and MnO2 nanoparticles. According to the data of scanning electron microscopy, the thickness of the obtained deposited layers does not exceed 3 μm. X-ray fluorescence analysis confirmed the presence of Mn and Co on the surface of the samples. The resulting membranes with a mass of 10 mg of the deposited layer of the oxide mixture were tested in the methylene blue decomposition reaction in dilute aqueous solutions (1,2 mg/L). The reaction was carried out in a batch reactor at room temperature, complete discoloration of the solution was observed after 180-240 minutes.

The process of leaf litter decomposition on the soil surface as a source of nutrition and food for soil fauna. Leaf litter decomposition rate is influenced by the activity of soil fauna, which is thought to increase the emission of carbondioxide from the soil. The aim of this research was to investigate the leaf decomposition rate and flux of carbon dioxide in various land cover. The research was conducted from July to November 2020 in Gunung Bromo Education Forest, Karanganyar, Central Java. This research used purposive sampling with nine land covers and three replications. The leaf decomposition rate was measured using the litterbag method, and flux of carbon dioxide was measured using the closed chamber method. The results suggested that the leaf decomposition rate was the fastest in Pine 2016 at 6.17 g/week, and the highest flux of carbon dioxide in Indonesian rosewood (Dalbergia sissoo) rejuvenation was 9,860 mg/CO2/day. The leaf decomposition rate was influenced by air temperature (p = 0.535) compared to humidity (p = - 0.257). Flux carbondioxide is influenced by air temperature (p = 0.854) compared to humidity (p = - 0.677), and the leaf decomposition rate affects the level of flux of carbon dioxide (p = 0.631).

This article mainly explores the process of decomposing wood that simulates the fungal community. Under the conditions of a given environmental temperature and humidity, the relationship between the decomposition rate of the fungus and the growth rate, moisture resistance, environmental temperature and humidity of the fungus is obtained. In the Logstic model, a competitive resistance term was introduced to describe the interaction between fungal communities. In the end, we get: The interaction between communities will mainly make the community evolve in two directions: multiple populations coexist and a single species survives. Community evolution is more sensitive to changes in humidity, while changes in temperature have a significant impact on the decomposition rate of fungal communities.. And through the analysis of climatic conditions in different regions, it is obtained that the fungal community prefers warm and humid environments. The diversity of the population causes the fungus community to have stronger resistance and resilience. The slow growth rate of the fungus will make the community more adaptable, and it also leads to the reduction of the overall decomposition efficiency of the community.

The method of TiSiCN-coatings deposition by anodic evaporation of Ti and decomposition of an organosilicon precursor (hexamethyldisilazane) in a low-pressure (∼1 mTorr) nitrogen-argon arc discharge with a self-heated hollow cathode is investigated. The plasma composition was analyzed by optical emission spectroscopy. TiSiCN coatings with a thickness of up to 10 microns and a hardness of up to 30 GPa were obtained in 1.5 hours at a temperature of 400 C. © Published under licence by IOP Publishing Ltd. The work was supported by the Russian Science Foundation (grant no. 20-79-10059).

In this study, the core-shell silica nanospheres modified with titanium dioxide were tested in the photocatalytic decomposition of dyes. The presented data underlines the advantages and shortcomings in the potential application of silica-based catalysts to neutralize organic pollutants. During the photocatalytic reaction in distilled water, catalysts showed decreased efficiency due to a carbon layer deposited on its surface. This finding set an additional goal to investigate the possibility of regenerating the photocatalyst. Studies have shown that the catalyst could be successfully reused following the thermal removal of deposited carbon.Furthermore, the reactivated silica-titania catalysts exhibited comparable photocatalytic performance to the newly made nanomaterial. Surprisingly, catalyst application in the river water eventually resulted in the permanent deactivation of silica-titania nanospheres, which was caused by the interchangeable silica dissolution/precipitation process on the surface of the studied nanomaterial. In environmental water, silica dissolves and precipitates on titanium dioxide's surface, blocking the interaction between organic compounds and TiO2. The deactivation occurring in the environmental samples is irreversible. In distilled water, the decomposition of organic compounds leads to photocatalysts' deactivation by forming a carbon layer on their surface. Reactivation of the silica-based photocatalyst after distilled water is achievable by annealing at a high temperature. In light of our findings, the combination of the photocatalytic properties of TiO2and the silica template shows no prospects in the purification of polluted waste or environmental water.

A set of cerium dioxide nanoparticles (CeO2 NPs) was synthesized by precipitation in water-alcohol solutions under conditions when the physical-chemical parameters of synthesized NPs were controlled by changing the ratio of the reaction components. The size of CeO2 NPs is controlled largely by the dielectric constant of the reaction solution. An increase of the percentage of Ce3+ ions at the surface was observed with a concomitant reduction of the NP sizes. All synthesized CeO2 NPs possess relatively high positive values of zeta-potential (ζ > 40 mV) suggesting good stability in aqueous suspensions. Analysis of the valence- and size-dependent rate of hydrogen peroxide decomposition revealed that catalase/peroxidase-like activity of CeO2 NPs is higher at a low percentage of Ce3+ at the NP surface. In contrast, smaller CeO2 NPs with a higher percentage of Ce3+ at the NP surface display a higher oxidase-like activity.

Photocatalytic technology has many new applications and great potential in providing clean energy and decomposing organic pollutants in the environment. Among them, TiO2 is a good photochemical catalyst, but has a limitation that is only shown in ultraviolet light. To expand the application of photocatalytic materials using solar radiation in visible light, this research focuses on the semiconductor photochemical transformation process. In this study, TiO2-Eu2O3 nanomaterial was synthesised by the sol-gel method with polyvinyl alcohol used as gelling agent. The effects of the contents of TiO2, Eu2O3 and the sintering temperature of the gel were investigated. The obtained material samples were analysed for characteristics and properties by the surface analysis techniques SEM, EDX, TEM, XRD, the infrared spectrum and the UV–vis molecular absorption spectrum. Analysis of modified TiO2 according to EDX, XRD showed the formation of crystalline and evenly dispersed Eu2O3 particles in TiO2 phases with an average particle size of 20–50 nm. The photocatalytic activity of TiO2-Eu2O3 nanoparticles was determined by the phenol decomposition efficiency in the hypothetical water sample and the actual wastewater samples with a concentration of 10 ppm under ultraviolet light and visible light. The resulting phenol decomposition was more than 90% efficient after about 150 min.

Sulfuryl fluoride (SO2F2) is one of the ideal decomposition components of sulfur hexafluoride (SF6), which is widely used as an insulating and arc extinguishing medium in gas-insulated switchgear. To detect the decomposition component of SF6 at room temperature, the use of SO2F2 is still a challenge. In this work, we have successfully fabricated TiO2 nanofibers and nickel sulfate (NiSO4 NPs) via simple electrospun and hydrothermal methods, followed by calcination process to improve the sensing performance. Metal oxide semiconductor materials (MOSs) are widely used in gas sensing applications due to their superior performance and fast recovery speed. Although the performance of our TiO2/NiSO4 composite nanofiber sensor decreases at higher temperatures, it shows an excellent response to target gasses at room temperature. Ni-decoration on the outer surface of the nanofibers could maximize the sensing response of 100 ppm SO2F2 by up to 189% at room temperature, showing that the TiO2/NiSO4 composite nanofibers are 2.5 times superior to the pure TiO2 nanofiber sensors. Thus, the approach for this novel composite nanofiber-based material is promising for the fabrication of superior gas sensors for decomposition of SF6.

The adsorption of cationic dye has been widely carried out by using polyacrylate, but it has a low ability to degrade the dye. On other hand, goethite has the opposite properties. This study aims to synthesis the composite of goethite-polyacrylate and its application for adsorption and degradation of methylene blue dye. The composite was synthesized by aging goethite at 40 °C for 7 days, polyacrylate then was added to goethite and the aging process was continued until 21 days. The synthesized composite was characterized by using Fourier Transform Infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The result indicated that the composite has better adsorption capacity compared to goethite with the uptake of adsorbed methylene blue is 625 mg/g. The equilibrium data fit the Langmuir isotherm model correlation efficient higher than 0.99. Goethite-polyacrylate composite efficiently degraded the methylene blue compared to polyacrylate. The combination of goethite and polyacrylate improved the properties of the material which has good adsorption and degradation performance.

Earthworms can be used as an indicator of fertility or soil quality. Its ability to decompose organic waste is very high. On the other hand, the organic waste generated by various human activities is enormous and continuous, including vegetable and fruit waste. In particular, pineapple peel waste which is a tropical fruit in traditional markets continues to be abundant and often becomes an environmental problem. The purpose of this study was to evaluate the rate of decomposition of pineapple peel waste by earthworms (Lumbricus rubellus, Hoff) based on different doses and water content. The research was conducted at the Biological Conservation Laboratory, University of Jember. Pineapple peel waste was taken from traditional markets in the city of Jember. Combination treatment between pineapple peel waste water content (dry and fresh) and addition of pineapple peel waste per week as much as 140 g / week and 280 g / week. The soil medium used was 1500 g and inoculated earthworms with biomass 20 (± 0.53) grams at the beginning of the treatment. The evaluation of decomposition rate was based on soil organic C content and was evaluated weekly for 5 weeks.The results showed that the dried pineapple peel waste obtained a faster decomposition rate than the wet condition (fresh). The highest average speed in the treatment of pineapple peel waste with drying and weekly additions of 140 g / week was 86.76% per week and the lowest was in the combination treatment of wet pineapple waste (fresh) and weekly addition of 28 g / week of 63.17% per week. The decomposition rate at the beginning of incubation or the highest first week was followed by a decrease in speed based on the time of incubation.

Fungi are critical to the carbon cycle. The growth rate model of fungi was constructed from three aspects of temperature, humidity and pH, and the moisture tolerance model of fungi was constructed from two aspects of competitive ranking and water ecotone width. Combined with related references, a fungal decomposition rate model was constructed based on the growth rate and moisture tolerance models. Under the given environmental conditions, the decomposer mass change curve was obtained by solving with MATLAB software, and the effect of environmental changes on the curve trend was investigated by the control variable method. The curve of decomposer mass change was obtained by calculating the competitive rank of the population and combining it with the fungal decomposition rate model.

Decomposition of lignin compounds into monomers from oil palm empty fruit bunches (OPEFB)has been successfully carried out. The purpose of this study was to determine the use of ilmenite as a lignin decomposerof OPEFB and to analyze the compounds produced using GC-MS method. The stages of the study consisted of preparation of ilmenite, pretreatment process of OPEFB, characterization of lignin isolates using FTIR, analysis of lignin content by UV-Vis, and photodegradation of lignin by GC-MS. Ilmenitewas known to have a potential for decomposing the lignin compound through a photodegradation reaction, in the presence of ultraviolet light. The results of this study indicated that a time of five hours decomposition could have degraded lignin up to 50%. The longer the degradation time, the more lignin was degraded to produce materials in the form of phenolic compounds, furan compounds, benzene derivatives and carbon compound derivatives from lignin monomers. One of the benzene derivatives obtained was 3,4-di (methoxycarbonyl) benzoic acid (C11H10O6).

The selective decomposition of formic acid (FA) traditionally needs to be carried out under high temperature with the noble metal-based catalysts. Meanwhile, it also encounters a separation of H2 and CO2 for pure H2 production. The photocatalytic FA dehydrogenation under mild conditions can meet a growing demand for sustainable H2 generation. Here, we reported a photocatalytic selective H2 release from FA decomposition at low temperature for pure H2 production by Pt/g-C3N4. Low-cost and easy-to-obtained urea was utilized to produce carbon nitride as the metal-free semiconductor photocatalyst, along with a photodeposition to obtain Pt/g-C3N4. The electrochemical evidences clearly demonstrate the photocatalytic activity of Pt/g-C3N4 to produce H2 and CO2 in one-step FA decomposition. And, the impedance is the lowest under simulated solar light of 70 mW cm−2 with a faster electron transfer kinetic. Under simulated solar light, H2 production rate is up to 1.59 mmol · h−1 · g−1 for FA with concentration at 2.65 mol l−1, 1700 000 times larger than that under visible light and 1928 times under ultraviolet (UV) light. DFT calculations further elucidate that nitrogen (N) active site at the g-C3N4 has an excellent adsorption towards CO2 molecule capture. Then, H2 molecules are selectively released to simultaneously separate H2 and CO2 in solution. Platinum (Pt) at Pt/g-C3N4 as the catalytic site contributes into the acceleration of H2 production.

A comparative study of the decomposition characteristic of SF6 under direct voltage with different polarities and pressure was conducted in this paper. The changes of discharge capacity, discharge energy and decomposition product concentrations were observed and analyzed in detail. The results indicate that SF6 decomposition characteristics are closely related to polarity and pressure. Discharge energy and concentrations of decomposition products under positive polarity are obviously higher than those under negative polarity, which can be explained by different discharge energy and distribution characteristic of space charges. Concentrations of typical products including SOF2, SO2F2, and SO2 decrease with the increasing pressure according to the decreasing effective dissociation volume.

Mangroves can be defined as forest vegetation that grows between tidal lines or is affected by tides. Trichoderma sp. is one type of fungus that is found in almost all types of soil and in various habitats which is one type of fungus that can be used as biological agents controlling soil pathogens. The purpose of this research is to know the acceleration of the decomposition rate of R. mucronata leaf litter by Trichoderma sp. at various levels of salinity in Belawan and test the carbohydrate and protein content. The research was conducted in December 2019-March 2020. The technique of placing the sample in a litter bag is placed at 3 points of the observation station based on differences in salinity. Decomposition rate values obtained were 10.20 at station I, 8.50 at station II and 7.05 at station III from the initial weight of observation on the days-15 to the observation period on the 90 day. The highest carbohydrate content was at Station I on the days-60 which was 13% and the lowest carbohydrate yield on the station III on the days-15 was 2.42%. The highest percentage of protein is 9.7% on the days-15 at station III and the lowest percentage of protein is 4.83% on the days-15 at station I.

Rhizophora mucronata leaf litter is a source of organic material for several organisms found in mangrove forest ecosystems. Leaf litter that falls on the forest floor will undergo a process of decomposition by biological agents within a certain time period. One effort to accelerate decomposition process is the use of fungi Aspergillus fumigatus. The purpose of this study was to measure the rate of decomposition and to measure the levels of carbohydrates and proteins contained in R. mucronata litter with different levels of salinity in the mangrove area of Hamparan Perak District. Carbohydrate and protein analysis is carried out at the Medan Industrial Research and Standardization Center. The average decomposition rate (k) of R. mucronata leaf litter at the 0-10 ppt salinity level is 10.89, the 10-20 ppt salinity is 7.74 and the 20-30 ppt salinity is 7.81. The Leaf Litter of R. mucronata experienced a decrease in carbohydrate levels. The highest carbohydrate content was found in Observation I station 3 which was 12.2% while the protein content in R. mucronata litter had increased. The highest protein content was found in observation VI of station 3 which was 6.78%. The decomposition rate in Belawan waters shows that productivity is good.

To analyze the law of decomposition and gas production of mixed insulating oil under the action of heat energy, this research conducted the decomposition test of mineral insulating oil, vegetable insulating oil and mixed insulating oil at different hot-spot temperatures through the thermal fault simulation test, compared and analyzed the gas production characteristics and differences of the three insulating oils under the action of heat energy, and analyzed the pyrolysis gas production mechanism of vegetable insulating oil. According to the test results, it can be found that under the condition of no insulating paper and metal catalyst, the characteristic gases produced by the three oils under the action of heat energy are the same, mainly H2, CH4, C2H4, C2H6, CO, CO2. When the temperature is higher than 700°C, a small amount of C2H2 will be produced; when the temperature is low overheated, the pyrolysis characteristic gases of mineral insulating oil are mainly H2 and CH4, while the characteristic gases of vegetable insulating oil and mixed insulating oil are H2 and C2H6; when heated, vegetable insulating oil is more easily to produce H2 than mineral insulating oil; under the same conditions, the CO and CO2 produced in the vegetable insulating oil are much more than that of the mineral insulating oil, dozens of times more at high temperature; the mixed oil presents similar characteristics to the vegetable insulating oil, which is consistent with the relatively large proportion of vegetable oil in the mixed oil.

Perfluorooctane sulfonate (PFOS) has attracted increasing attention due to its global distribution, high chemical stability and environmental persistence. An alkaline ultrasonic system was explored and used for PFOS decomposition in this study. kobs of PFOS decomposition in the investigated system was 0.0196 min−1, which was remarkably efficient than that in sole ultrasonic system. eaq − induced reductive decomposition and pyrolysis decomposition based on the collapse of cavitation bubble were found to be two main reasons contributing to PFOS decomposition. PFOS decomposition kinetics was boosted by increasing alkaline dosage and reaction temperature, but suppressed when increasing initial PFOS concentration.

An alternative fuels is obtained by co-pyrolysis of waste plastics and oil shale as well as contribute to the search of technologies that reduce the negative environmental impact of waste. Shale oil and waste plastic are unconventional sources of energy. The two materials are significant to Nigeria’s economic sustainability but yet to be exploited efficiently. The aim of this work is to reduce the energy needed to obtain shale oil via kinetic parameters by the thermal decomposition of Lokpanta oil shale mixed with plastics. The kinetics of the thermal decomposition of Lokpanta oil shale/ polyethylene blend was determined using data provided by thermo-gravimetric analysis done at 28°C to 887.44°C with heating rate of 10°C/min and a nitrogen flow rate of 60ml/min. The decomposition of the co-pyrolysis of the mixture of Lokpanta oil shale and the polyethylene was recognized in three stages, of which the first stage was between 28 and 316.41°C which corresponded to the loss of water from the sample. The second stage was between 316.41°C and 481.47°C, which depicted an overlap of the organic matter (kerogen) and the degradation of polyethylene. The final stage was between 481.47°C and 887.44°C, and it exposed the decomposition of the mineral matter of the oil shale. The Kinetic parameter was determined using non-isothermal methods of degradation. Hence the presence of the plastic acted as catalyst in the decomposition of the organic matter of the shale which consequently lowered the activation energy required to obtain shale oil with relevant application as aliphatic fractions of petroleum.

The decomposed leaves of R. mucronata are a source of organic material or nutrients for plants and various types of biota associated in the Belawan Mangrove Area. One of the microorganisms that play a role in the decomposition process is Aspergillus sp. The purpose of this study was to determine the acceleration of the rate of decomposition and measure the carbohydrate and protein content of R. mucronata leaf litter that had been decomposed by Aspergillus sp at various levels of salinity in Belawan. This research was conducted in June 2019-March 2020. The average litter decomposition rate was obtained using the Olson Formula (1963): ln (Xt / X0) = -kt, analysis of carbohydrate and protein content using SNI methods 01-2891-1992. The fastest decomposition rate of R. mucronata leaves is at station 1 with salinity 0-10 ppt which is 10.02 / year and the lowest is at station 2 with salinity 11-20 ppt which is 7.51 / year. The highest average carbohydrate content at station 1 is 7.02 and the lowest content of station 2 is 5.18%. The highest average protein content at station 3 ppt is 5.62% and the lowest is station 2 which is 4.28%.

The current research about SF6 switchgear failures mainly focuses on various troubleshooting methods, while ignoring the impact of SF6 gas decomposition products on equipment and the types of failures they reflect, and the application of SF6 gas decomposition products to diagnose equipment failures still needs to be further explored and improved. Therefore, this paper focuses on the study of the decomposition process of SF6 under partial discharge failure, and conducts theoretical analysis of the decomposition product composition of SF6 under partial discharge failure, and detects SF6 gas decomposition products by gas chromatography. Finally, it can be concluded that when the concentration of S2F10 and S2OF10 is about 5μL/L, the switchgear is likely to have a partial discharge failure. At this time, the maintenance personnel should deal with it in time to ensure that the switchgear can be put into use normally.

In this paper we find the Circular Divison of The ℱactor Group cℱ(2 2κ×D4, ℤ)/ ρ ¯ (2 2κ ×D4) when κ is a prime number, where 2 2κ is denoted to Quaternion group of order 4k, such that for each positive integer n, there are two generators X and Y for 2 2κ satisfies Q2k={ X i Y j, 0≤ i ≤ 2κ − 1, j=0, 1} which has the following properties{ X 2k=Y 4=I, Y X k Y -1=X -k} and D4 is the Dihedral group of order 8 is generate by a rotation e of order 4 and reflection f of order 2 then 8 elements of D4 can be written as: {I*, e, e2, e3, f, fe, fe2, fe3}.