Search

Rubber is a waste product produced by the industrial sector in large quantities. Due to its non-degradable nature, it has been a serious threat to the environment. Thus, it is recommended to develop concrete or mortar containing rubber, so that it can save our environment, and it is economical too. Crumb rubber, when incorporated in mortar, reduces its strength, so it can be used along with some fibers to enhance its strength. This study examined the effect of elevated temperatures, i.e., 150, 300, 450, 600, and 750 °C, on mortar samples containing 5% crumb rubber replacement of fine aggregate by volume, and with the incorporation of 1% PPF. The findings indicated a rise in compressive strength up to 300 °C, followed by a subsequent decline. It was also observed that the weight loss of the samples increased with an increase in temperature. [ABSTRACT FROM AUTHOR]

The disposal of crop residues from agricultural fields is often seen as a burden due to the difficulties involved. However, this study aims to turn pigeonpea stalks into biochar, which can serve as a fuel substitute and soil amendment to sequester carbon. Different pyrolysis methods were employed to investigate the variations in yield, physicochemical characteristics, and higher heating value (HHV) of biochar produced from pigeonpea stalks. The biochar produced using a muffle furnace exhibited higher fixed carbon and ash content. These characteristics make it beneficial for restoring degraded agricultural soils by enhancing carbon sequestration. In addition, the muffle furnace biochar demonstrated a total potential carbon ranging from 262.8 to 264.3 g of carbon per kilogram of biochar, along with a CO2 reduction potential ranging from 77.17 to 79.68 CO2 eq per kg. Both the European Biochar Certificate and the International Biochar Initiative confirmed the agronomic abilities of the biochar and its compliance with the highest quality standards for soil carbon sequestration, with 0.11 H/C and 0.7 O/C ratios. Furthermore, biochar produced by muffle furnace from pigeonpea stalks exhibited superior fixed carbon recovery efficiency (181.66 to 184.62%), densification (5.86 to 6.83%), energy density (1.77 to 2.06%), energy retention efficiency (54.80 to 56.64%), fuel ratio (18.95 to 22.38%), and HHV (30.66 to 32.56 MJ kg−1). Additionally, it had lower H/C and O/C ratios, suggesting its potential as an alternative solid fuel. The results of the characterization of biochar with scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) revealed that the biochar samples prepared with both the methods had carbonyl (C=O), C=C, and aromatic C-H functional groups; however, the biochar prepared in the muffle furnace had more porosity. In summary, this study highlights the potential of using pigeonpea stalks to produce biochar, which can be utilized as a renewable fuel substitute and soil amendment to sequester carbon. The biochar derived from the muffle furnace exhibited desirable physicochemical characteristics, high carbon content, and excellent energy properties, making it a promising option for various applications. [ABSTRACT FROM AUTHOR]

Bioadsorbents prepared by chemical activation (H3PO4) of the residue of supercritical extraction of green tea leaves and marigold flowers were characterized by elemental analysis, Boehm titration, adsorption/desorption isotherm and scanning electron microscopy (SEM). The adsorption performance aimed at the removal of malachite green, nitrogen oxide and hydrogen sulfide was investigated. The impacts of various influential parameters of malachite green adsorption such as: contact time (8 h), initial dye concentration (20–140 mg/L), temperature (25–65 °C) and adsorbent mass (0.015–0.025 g) were investigated. The adsorption kinetic follows pseudo second-order reaction kinetics (R2 > 0.99). The adsorption process was best described by the Langmuir isotherm and the maximum capacity of the monolayer was from 126.58 mg/g to 333.33 mg/g for the biocarbons obtained. The negative values of Gibbs free energy indicate the spontaneous character of the process. The presence of steam in the stream of the mixture of gases had a positive effect on adsorption of nitrogen oxide and hydrogen sulfide by the bioadsorbents obtained. The most effective adsorbent of malachite green and toxic gas pollutants proved to be the biocarbon obtained from the residues of supercritical extraction of green tea leaves. [ABSTRACT FROM AUTHOR]

Purpose. To develop the method and software for building empirical models of muffle furnaces with two heating elements. Methodology. The method for processing experimental data according to the improved algorithm, which is based on the areas method, is used for constructing empirical models of the muffle furnace. Experimental research of the muffle furnace dynamic is conducted using the following methodology. The muffle furnace is cooled to the room temperature and then the lower heater is turned on and temperatures at the furnace output are fixed using the experimental two-channel temperature controller MIC-344. The second cycle of the experimental research began by cooling the furnace to the room temperature with turning on the upper heater. Observations based on the results of the experiment are conducted until the temperature is stabilized at the two outputs of the muffle furnace. Archiving of temperature trends is carried out using the RS485/Ethernet interface and the SmartReview software (a product of private limited company “Microl”). Findings. The developed software can be used for iteratively selection of the optimal empirical model based on the criterion of the root mean square deviation of the calculated and experimental data. The calculating method for the acceleration curve based on the transfer functions coefficients with a variable discreteness step is improved in order to compare the experimental data with the empirical modeling results. Twelve empirical models were tested for four signal transmission channels in the process of experimental research. It has been established that only four of them are stable (have left-hand roots of the characteristic equation). Among the selected sustainable models, the model with the numerator polynomial equaled to two and denominator polynomial equaled to three has been established as the best model (according to the established criterion). A structural diagram is created based on the synthesized empirical model of the muffle furnace, which includes four transfer functions and cross connections. Originality. For the first time, the empirical model of a muffle furnace with two electrical energy sources has been developed, which describes its dynamic properties as the object of automatic control with high accuracy, which enables to reveal the presence of internal cross-connections, that significantly complicate the controlling process of the object. Practical value. The created empirical models with two electric sources (tens) can be used for the synthesis of the high-precision automatic temperature control system of the muffle furnace. [ABSTRACT FROM AUTHOR]

In recent times, reduced graphene oxide has gained more attention in various fields. In our study, a direct synthesis of reduced graphene oxide using a novel carbon-rich agro-waste from Pennisetum glaucum was used. Ferrocene acted as an oxidizing agent during thermal degradation at 300 °C for 15 and 20 min to promote graphene oxide and reduced graphene oxide formation. The X-ray diffraction peak at 2θ indicating a shift from 16.86 to 24.28°, presence of functional groups like –OH stretching, –C = C–, C = O, C–O, and C–OH by Fourier transmission infrared spectroscopy, prominent D and G bands at 1308 cm−1 and 1578 cm−1 by Raman spectra and UV–visible spectroscopy peak shift from 235 to 245 nm (π–π*, C = C bonds) confirmed the reduction of graphene oxide to reduced graphene oxide. The average particle size values 233.3 nm for graphene oxide and 63.57 nm for reduced graphene oxide illustrate the nanoscale range of our synthesized material. The negative zeta potential values in the range − 45.5 mV and − 29.5 mV for graphene oxide and its reduced forms infer the dispersion stability along with surface oxygen group presence. We have also highlighted the formation of graphene oxide quantum dots by magnetic stirring and confirmed by UV transilluminator and photoluminescence spectra. The photodegradation efficiency was optimized using central composite design for dosage, dye concentration, pH, and time for both malachite green and reactive blue dye. The kinetic studies report pseudo-first-order kinetic model for catalytic degradation and statistical Analysis of variance proved the significance of the process for p value < 0.05. Thus, the synthesized graphene materials could be used as a potential candidate for environmental applications. [ABSTRACT FROM AUTHOR]

Rubber is a waste product produced by the industrial sector in large quantities. Due to its non-degradable nature, it has been a serious threat to the environment. Thus, it is recommended to develop concrete or mortar containing rubber, so that it can save our environment, and it is economical too. Crumb rubber, when incorporated in mortar, reduces its strength, so it can be used along with some fibers to enhance its strength. This study examined the effect of elevated temperatures, i.e., 150, 300, 450, 600, and 750 °C, on mortar samples containing 5% crumb rubber replacement of fine aggregate by volume, and with the incorporation of 1% PPF. The findings indicated a rise in compressive strength up to 300 °C, followed by a subsequent decline. It was also observed that the weight loss of the samples increased with an increase in temperature.

Aim: The aim of this research is to fabricate an aluminium hybrid metal matrix composite reinforced with a 15% weight fraction constituting 7.5% of silicon carbide and 7.5% of fly ash using the stir casting method under controlled process parameters and compare tensile strength, compressive strength, hardness and corrosion resistance with pure as-cast Aluminium 6061. Materials and Methods: Samples of dimensions 150mm x 150mm and thickness 10mm are prepared under Identical conditions adhering to standards. For g power calculations (threshold level: 0.20, confidence interval: 80%) gives a sample size of 80. Mechanical tests are taken individually on each sample for 20 samples of the experimental group (AHMMC) and control group (As-cast AL6061) as per ASTM standards. Results: One-way ANOVA using SPSS software shows that AHMMC with a 15% weight fraction of SiC and Fly ash has a significantly higher tensile strength (38.97 MPa), compressive strength (55.91 kN), and hardness (76 HV) but has slightly lower corrosion resistance (1.659 mm/year) than that of as-cast Al6061 with a significance level of 0.036 (p<0.05). Conclusion: Within the limitations of this study, It is revealed that AHMMC with a 15% weight fraction of SiC+Fly ash exhibited enhanced Mechanical and physical properties when compared to as-cast Al6061. [ABSTRACT FROM AUTHOR]

At present, aluminum alloys are widely used alloys after iron-carbon alloys in the production of mechanical engineering parts. The article presents the process of alloying an alloy of grade 8176 aluminum with a combination of lithium fluoride. Bunda quoted the legirlash process in the same way. In the first method, lithium fluoride powder was mixed with a halide aluminum alloy wrapped in aluminum foil. In the second method, lithium fluoride powder was mixed with an aluminum alloy without exposure. Experiments have shown that a combination of 3 different amounts of lithium fluoride is introduced into the aluminum alloy. A combination of lithium fluoride is mixed in an amount from 5 gr to 15 gr. The experiments were carried out in a muffle furnace of the brand SNOL-1,6.2,5.1/11-I2M. The experiments carried out led to the fact that the furnace is set to 750 °C. In the article, the authors identified a lot of details of the samples obtained during the experiments and presented the relevant analyses and conclusions. [ABSTRACT FROM AUTHOR]

Concrete’s thermal properties are more complex than for most materials because not only is the concrete a composite material whose constituents have different properties, but its properties also depend on moisture and porosity. Exposure of concrete to elevated temperature affects its mechanical and physical properties. In the current study, M40 and M80 grades of plain self-compacting concrete (SCC) mixes are developed using Nan Su mix design principles to investigate the effect of elevated temperatures on 1) weight and compressive strength 2) compressive strength of SCC when tested cool and hot 3) effect of 2, 4 and 6 hrs. exposure duration of elevated temperatures on compressive strength 4) modulus of elasticity 5) size of testing specimen and 5) effect of thermal cycles on SCC mixes. Results derived the following conclusions 1) the M80 specimens lose more strength than M40 SCC specimens when subjected to elevated temperatures ;2) specimens heated and then permitted to cool before testing lose more strength than those tested while hot; 3) the longer the duration of heating before testing, the larger the loss in strength; 4) The decrease in modulus of elasticity caused by elevated-temperature exposure is more pronounced than the decrease in compressive strength. 5) Small test specimens generally incur greater strength losses than larger ones and 6) Specimens subjected to several cycles of heating and cooling lose more strength than those not subjected to thermal cycling.

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

The influence of carbide-forming metals on the wear of ceramic inserts in cutting hard-to-machine 12Х18Н9Т steel is studied theoretically. In addition, the influence of nitrogen on the yield point of the unmodified cutting ceramic and the alloyed ceramic is analyzed, and the influence of carbon and the temperature on the cutting ceramic's limit of proportionality is determined. It is found that the impact strength of VOK-60M ceramic inserts is changed after diffusional hardening with nitrogen at pressure р = 025 MPa and temperature θ = 250°C. The ceramic inserts undergo X-ray spectral analysis so as to detect any changes in the lattice structure under the action of a magnetic field on saturation with nitrogen; the formation of floccules (of hair type b) in the section; or carbide deposits within the grains in the ceramic inserts. [ABSTRACT FROM AUTHOR]

Surface roughness variation of optically rough polycrystalline silicon solar wafer by annealing at different temperatures is presented. Laser speckle images produced by annealed polycrystalline silicon solar wafer wafers are recorded and converted into binary images. The binary speckle images are characterized by fractal box counting method. The fractal dimensions decreases, while annealing temperature increases; therefore, the polycrystalline silicon solar wafer roughness decreases while annealing temperature increases. [ABSTRACT FROM AUTHOR]

The extensive discomfort in the expulsion of toxic pollutants even at mild concentrations has demanded the need for prompt methods for the evacuation of dyes and heavy metals. The effective method for depuration of dye from the effluent is by sorption. Chitosan is a bio‐polymer which is gaining an increasing interest as one of the sorbents. It was obtained from the crab shells by undergoing several chemical processes and used as an adsorbent for dye, metal removal and also for pharmaceutical purposes. Cross linking it with other co polymers will increase the capacity of adsorption to a maximum level. Fish scales are considered to be a major waste in the food industry and since it takes a long time for decomposing it is considered to be one of the pollutants. Hence it is utilised by converting it into activated carbon by preliminary treatment and into a muffle furnace. The obtained activated carbon is combined with chitosan by using a cross linker and utilised for adsorption mechanism. To analyse the effect of chitosan cross linked with activated carbon obtained from fish scales in adsorption of dye Reactive Blue 9 (RB9) to evaluate the adsorption studies, kinetics, mass transfer studies, thermodynamics of the bio adsorbent. [ABSTRACT FROM AUTHOR]

Rice husk is one of the main agricultural by products of rice processing, which is brown in colour. Rice husk forms a hard protective layer around the grains of rice, and these husks are formed from the hard materials such as opaline and lignin to protect the seed during the growing period. Rice husk is an agricultural waste covering rich sources of minerals and have more than 95% silica. SiO2 is the most abundant mineral in the world. The rice husk samples procured from the suppliers were washed with water and dried for nearly 20 h to ensure that the rice husk is devoid of soil, dust, and rice grains particles. Rice husk was preheated at 600°C in muffle furnace to get ash. A simple method based on alkaline extraction followed by acid precipitation to produce pure silica. The synthesized silica nanoparticles were characterized by FT-IR, XRD and SEM-EDAX. [ABSTRACT FROM AUTHOR]

This study explored the fabrication of activated carbon from teff husk biomass using microwave and muffle-furnace-assisted heating and observed its effect on surface characteristics and the thermodynamics, isotherm, and kinetics of Pb2+ ions removal. Chemical activation of the teff husk was carried out using ZnCl 2 as an activating agent. The microwave-assisted activated carbons (MW-THAC) and muffle furnace-assisted activated carbon (MF-THAC) were characterized for surface area, pHzpc, functional groups, thermal stability, phase composition, surface morphology, and surface-elemental compositions. The surface area of MW-THAC and MF-THAC was found to be 9.81 m2/g and 327.54 m2/g, respectively. Thermodynamic parameters indicated that the interaction with MW-THAC and MF-THAC was spontaneous and endothermic. The maximum Pb adsorption capacities of MW-THAC and MF-THAC calculated using the Langmuir model at 45 °C were found to be 20.45 mg/g and 26.04 mg/g, respectively. Pb2+ removal through MW-THAC followed the Langmuir isotherm and the pseudo-first order kinetic model. However, the Freundlich isotherm and pseudo-second order kinetic models best describe Pb2+ adsorption onto the MF-THAC surface. The desorption study shows that 80.6 % and 78.7 % of Pb2+ ions can be recovered from the surfaces of the MW-THAC and MF-THAC adsorbents. This study confirms that activated carbon derived from teff husk could be a potential candidate for the adsorption and recovery of Pb2+ ions. [Display omitted] • The BET surface area of MW-THAC and MF-THAC were 9.81 and 327 m2/g. • At 25 and 45 °C temperatures, the adsorption capacity of MW-THAC against Pb2+ was 17 and 20 mg/g. • At 25 and 45 °C temperatures, the adsorption capacity of MF-THAC against Pb2+ was 25 and 26 mg/g. • The Pb2+ removal followed the Langmuir isotherm and PFO kinetic model for MW-THAC. • The Pb2+ removal followed the Freundlich isotherm and PSO kinetic model for MF-THAC. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Production technology is developed for capillary pipe used in disposable medical syringes. The heat treatment of the pipe in pure hydrogen with inert-gas injection is described. In industrial research, the annealing of the capillary pipe in an electrical furnace is optimized. The temperature field within the muffle furnace is analyzed. The optimal flow rate of protective gas and the limiting permissible flow rate of the injected gas (nitrogen and argon) are determined. The mechanical properties of the pipes (blanks) welded at Tyumen Medical-Supply Plant and manufactured at Pervouralsk New Pipe Plant (PNTZ) are studied. When using nitrogen as the protective gas instead of hydrogen, the likelihood of obtaining clean pipe surfaces is greatly increased. [ABSTRACT FROM AUTHOR]

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.

Wastewater discharge from textile industries contribute much to water pollution and threaten the aqua ecosystem balance. Synthesis of agriculture waste based adsorbent is a smart move toward overcoming the critical environmental issues as well as a good waste management process implied. This research work describes the adsorption of methylene blue dye from aqueous solution on nickel oxide attached magnetic biochar derived from mangosteen peel. A series of characterization methods was employed such as FTIR, FESEM analysis and BET surface area analyzer to understand the adsorbent behavior produced at a heating temperature of 800 ∘ C for 20 min duration. The adsorbate pH value was varied to investigate the adsorption kinetic trend and the isotherm models were developed by determining the equilibrium adsorption capacity at varied adsorbate initial concentration. Equilibrium adsorption isotherm models were measured for single component system and the calculated data were analyzed by using Langmuir, Freundlich, Tempkin and Dubinin–Radushkevich isotherm equations. The Langmuir, Freundlich and Tempkin isotherm model exhibit a promising R2-correlation value of more than 0.95 for all three isotherm models. The Langmuir isotherm model reflectsan equilibrium adsorption capacity of 22.883 mg ⋅ g − 1 . [ABSTRACT FROM AUTHOR]

Calcination temperature plays a crucial role in determining the surface properties of generated MgO, but the influence of temperature variation in a muffle furnace during calcination on its performance is rarely reported. Herein we observed that the temperature in a muffle furnace during calcination demonstrated a gradually increasing trend as the location changed from the furnace doorway to the most inner position. The variation in temperature had a great impact on the adsorption performance of generated rod-like MgO without and/or with involvement of Na2SiO3 to Congo red in aqueous solution. To get a better understanding on the detailed reasons, various techniques including actual temperature measurement via multimeter, N2 physical adsorption, CO2 chemical adsorption and FT-IR spectrometry have been employed to probe the correlation between the adsorption performance of generated MgO from various locations and the inner actual temperature of used muffle furnace as well as their physicochemical properties. In addition, two mechanisms were proposed to elucidate the adsorption process of Congo red over the surface of generated MgO without and/or with presence of Na2SiO3, respectively. [ABSTRACT FROM AUTHOR]

Calcium is a vital element for the mineralization of the growing foetus. Quantitative estimation of calcium content of palacenta of normal and hypertensive group with history of antepartum haemorrhage showed no significant difference. The study was carried out to see whether calcified placenta was the cause of poor foetal outcome. [ABSTRACT FROM AUTHOR]

Carbon doped TiO2 (C-doped TiO2) photocatalyst was prepared by using polyethylene glycol (PEG) as carbon precursor under calcination process using muffle furnace. The modified C-doped was immobilized onto a glass plate by using brush and DSAT method with the optimum C-doped TiO2 was measured by the highest photoactivity detected from photodegradation of reactive red 4 (RR4) dye. The optimum condition of C-doped TiO2 denoted as C2 consist of 0.1 g of PEG in 6.5 g TiO2 was found where the photodegradation rate of C2 was ca 0.1545 min-1 and it is 2.5 times faster as compared with unmodified TiO2. The presence of C-C bond represented as carbon element was detected in all C-doped TiO2 samples analyzed by Fourier Transform Infrared (FTIR) spectra at 933 nm. No bandgap energy of C-doped TiO2 samples changes was recorded by UV-vis DRS spectroscopy, all C-doped TiO2 except C1 have shown higher photocatalyic activity as compared with unmodified TiO2 due to the presence of carbon in which acts as electron scavenger. No significant changes in term of surface morphology between C-doped TiO2 and unmodified TiO2 sample observed by SEM images. The C-doped TiO2 immobilized sample produces a fine surface with a smooth coating, excellent photodegradation of RR4 dye and can be used in wide range solar applications. [ABSTRACT FROM AUTHOR]