Weight Percentage Of Carbon Research Articles

Development and characterization of carbon fiber reinforcement in Aluminium metal matrix composites

Abstract Carbon fibers (CF) possess exceptional mechanical properties and the highest degree of chemical stability. However, carbon reinforcement in metal matrix composites is extremely scarce due to production difficulties, particularly in obtaining a uniform distribution. Carbon fiber reinforced composites are typically made using high temperature processing processes. However, the fibers must be coated with Ni or Cu in order to achieve effective particle dispersion; otherwise, there is a larger likelihood of intermetallic compound formation, which reduces the chances for enhanced properties. In this work, the metallurgical, mechanical, and tribological characteristics of the carbon fiber reinforcement in AA 7050 are examined. Uncoated carbon fibers are reinforced into the Aluminium matrix using a low temperature processing technique known as powder metallurgy. The AA 7050 matrix reinforced with carbon fibers at various weight percentages between 0 and 1.5. The samples undergone mechanical and metallurgical testing in accordance with ASTM guidelines. The findings indicate that the 0.25 weight percent carbon fiber reinforcement in the matrix increased the material’s hardness by 30% over the monolithic alloy, making it an excellent alternative for structural applications.

Carbon encapsulated CdTe nanorods to execute the enhanced and photo corrosion free hydrogen production

We present carbon-encapsulated CdTe nanorods synthesized through a well-established hydrothermal method. The impact of varying weight percentages of carbon on CdTe nanorods has been explored. XRD, HR-TEM, XPS, Raman and UV-Vis characterization techniques are used to examine the physicochemical and optical properties of prepared compounds. The loading of the carbon layer can be regulated by varying the quantity of sucrose utilized during the synthesis process. The optimized photocatalyst exhibits a superior rate of hydrogen evolution at 247.7 mmol. h−1. g−1cat compared to bare CdTe nanorods. Here, the carbon layer serves a dual purpose as a photocorrosion inhibitor and facilitates electron tunneling for surface reactions. This combined effect of carbon on CdTe is responsible for the observed improvement in the hydrogen evolution rate. As the loading of carbon varies, the activity is aligning closely with the light penetration effect in photocatalysis. Furthermore, we investigated the durability of the optimized photocatalyst, revealing that it retains 89 % of its initial activity even after five cycles. After the activity experiments, essential characterizations such as XRD, Raman and XPS were also analyzed, and the solar to H2 conversion efficiency was computed.

Novel third order nonlinear optical stilbazolium crystal replaced with 3-methoxy benzaldehyde as donor for optical device applications

A novel organic nonlinear optical stilbazolium group single crystal of 1-methyl-2-[2-(3-methoxystyryl)]-pyridinium iodide (subsequently referred to as MSMI) was grown by the solution growth technique using the method of slow evaporation at ambient temperature. The Single-crystal XRD investigation indicates that the MSMI crystal belongs to a monoclinic crystal system with a centrosymmetric space group. CHN elemental analyser confirms the weight percentage of carbon (C = 51.00 %) hydrogen (H = 4.55 %) and nitrogen (N = 3.94 %) in the MSMI crystal structure. The presence of 16 hydrogen atoms and 15 carbon atoms in the MSMI was affirmed by the Nuclear Magnetic Resonance (NMR) spectroscopic analysis. Fourier Transform Infrared (FTIR) studies confirmed the fundamental vibrations for different functional groups found in the MSMI crystal. The Hirsfeld surface analysis figured out the hydrogen bond interaction and π…π interaction which supports the stability of the crystal structure. The crystal is found to exhibit transmittance of wavelength above 400 nm and has a band gap of 3.05 eV ascertained from UV–Vis-NIR spectroscopic analysis. Photoluminescence (PL) studies reveal that the title crystal has an emission wavelength of 572 nm. The surface characteristics of the title crystal were examined by Atomic Force Microscopy (AFM), and etching studies. The value of Meyer's number is n = 1.8 which is determined by the Vickers microhardness studies. The value of the third-order nonlinear refractive index (n2) is 4.662×10−8 cm2/W, the nonlinear absorption coefficient (β) is 1.305×10−3 cm/W, nonlinear susceptibility (χ(3)) is 9.297×10−5 esu and the optical limiting threshold is 11.43 J/cm2 was ascertained form the Z-scan technique. The results indicate that the MSMI crystal is a potential optical limiter and has promising applications in nonlinear optical devices.

Comparative study between micro- and nano-carbon with epoxy for gamma shielding applications

In the current study, the epoxy material was mixed with 10%, and 30% weight percent carbon material as filler in different thicknesses (1 cm, 1.5 cm, and 2 cm). Transmission electron microscope (TEM) measurements showed the average size of the nano-carbon was 20 nm with a standard deviation of 5 nm. The morphology of samples was examined using scanning electron microscopy (SEM), which showed the flatness of the epoxy surface, and when the content of carbon increases, the connection between the epoxy array and carbon increases. The compression test indicates the effect of nano-size on enhancing the mechanical properties of the studied samples. To survey the shielding properties of the epoxy/carbon composites using gamma-rays emitted from Am-241, Ba-133, Cs-137, Co-60, and Eu-152 sources, which covered a wide range of energies from 0.059 up to 1.408 MeV, the gamma intensity was measured using the NaI (Tl) detector. The linear and mass attenuation coefficients were calculated by obtaining the area under each peak of the energy spectrum observed from Genie 2000 software in the presence and absence of the sample. The experimental results obtained were compared theoretically with XCOM software. The comparison examined the validity of experimental results where the relative division rate ranged between 0.02 and 2%. Also, the measurement of the relative division rate between linear attenuation coefficients of micro- and nano-composites was found to range from 0.9 to 21% The other shielding parameters are calculated at the same range of energy, such as a half-value layer (HVL), mean free path (MFP), tenth-value layer (TVL), effective atomic number (Zeff), and the buildup factors (EBF and EABF). The data revealed a consistent reduction in the particle size of the shielding material across various weight percentages, resulting in enhanced radiation shielding capabilities. The sample that contains 30% nano-carbon has the lowest values of TVL (29.4 cm) and HVL (8.85 cm); moreover, it has the highest value of the linear attenuation coefficient (LAC), which makes it the best in its ability to attenuate radiation.

Dual Functional Magnetic Nanoparticles Conjugated with Carbon Quantum Dots for Hyperthermia and Photodynamic Therapy for Cancer.

The global incidence of cancer continues to rise, posing a significant public health concern. Although numerous cancer therapies exist, each has limitations and complications. The present study explores alternative cancer treatment approaches, combining hyperthermia and photodynamic therapy (PDT). Magnetic nanoparticles (MNPs) and amine-functionalized carbon quantum dots (A-CQDs) were synthesized separately and then covalently conjugated to form a single nanosystem for combinational therapy (M-CQDs). The successful conjugation was confirmed using zeta potential, Fourier transform infrared spectroscopy (FT-IR), and UV-visible spectroscopy. Morphological examination in transmission electron microscopy (TEM) further verified the conjugation of CQDs with MNPs. Energy dispersive X-ray spectroscopy (EDX) revealed that M-CQDs contain approximately 12 weight percentages of carbon. Hyperthermia studies showed that both MNP and M-CQDs maintain a constant therapeutic temperature at lower frequencies (260.84 kHz) with high specific absorption rates (SAR) of 118.11 and 95.04 W/g, respectively. In vitro studies demonstrated that MNPs, A-CQDs, and M-CQDs are non-toxic, and combinational therapy (PDT + hyperthermia) resulted in significantly lower cell viability (~4%) compared to individual therapies. Similar results were obtained with Hoechst and propidium iodide (PI) staining assays. Hence, the combination therapy of PDT and hyperthermia shows promise as a potential alternative to conventional therapies, and it could be further explored in combination with existing conventional treatments.

G-C3N4/TiO2 for gas-phase formaldehyde photodegradation under visible light in the humidity control coatings

BackgroundsThe control of relative humidity and degradation of volatile organic compounds are regarded as major considerations in the enhancement of living quality in the indoor environment. From the viewpoints of circular economy, the valorization of inorganic wastes to prepare green building materials is crucial. MethodsFor the practical applications, the multifunctional coatings, applied in the indoor humidity control and photocatalytic degradation of formaldehyde, are prepared by recovering inorganic wastes (i.e., white carbon (WC) and spent fluid catalytic cracking catalysts (sFCCC)) and photocatalysts (graphitic carbon nitride/TiO2, denoted as GCN/TiO2) via a simple sol-gel method. Various physicochemical and analytic tools are used to characterize the coating properties and performance. Significant findingsCompared to commercial coatings, the prepared multifunctional coatings (i.e., W/B/S-47/47/6, where W, B and S represent the weight percentage (%) of white carbon, bassanite and sFCCC, respectively) have superior textural properties which can improve the buffering ability of indoor humidity. Moreover, the W/B/S-47/47/6 coatings exhibit the surpassing photodegradation of formaldehyde over commercial coatings by ca. 3 times. The higher charge transfer kinetics and greater thermodynamic driving force toward superoxide radical formation are responsible for the improved photocatalytic activity of W/B/S-47/47/6 coatings. According to the toxicity characteristic leaching procedure tests, no evident leaching heavy metals are observed, which provides an environmental-friendly and economical route for valorization of inorganic wastes.

Synthesis and Characterization Graphene- Carbon Nitride Nanostructure in One Step

Graphene-carbon nitride can be synthesized from thiourea in a single step at a temperature of four hours at a rate of 2.3 ℃/min. Graphene-carbon nitride was characterized by Fourier-transform infrared spectroscopy (FTIR), energy dispersive X-ray analysis (EDX), scanning electron microscopy, and spectrophotometry (UV-VIS). Graphene-carbon nitride was found to consist of triazine and heptazine structures, carbon, and nitrogen. The weight percentage of carbon and the atomic percentage of carbon are 40.08%, and the weight percentage of nitrogen and the atomic percentage of nitrogen are 40.08%. Therefore, the ratio and the dimensions of the graphene-carbon nitride were characterized by scanning electron microscopy, and it was found that the radius was within the range of (2 µm-147.1 nm). In addition, it was found that it absorbed light in the visible field (VIS). The objective of the manufacture and characterization of graphene-carbon nitride for use in the manufacture of a selective electrode for an organic pollutant (currently used in the manufacture of a selective electrode for the analysis of organic dye).

Three-Dimensional Hollow Reduced Graphene Oxide Tube Assembly for Highly Thermally Conductive Phase Change Composites and Efficient Solar-Thermal Energy Conversion.

Due to their extraordinary mechanical strength and electrical and thermal conductivities, graphene fibers and their derivatives have been widely utilized in various functional applications. In this work, we report the synthesis of a three-dimensional (3D) hollow reduced graphene oxide tube assembly (HrGOTA) using the same wet spinning method as graphene fibers. The HrGOTA has high thermal conductivity and displays the unique capability of encapsulating phase change materials for effective solar-thermal energy conversion. The HrGOTA comprises layers of moisture-fused hollow reduced graphene oxide tubes (HrGOTs), whose individual thermal conductivity is up to 578 W m-1 K-1. By impregnating 1-octadecanol into HrGOTs, a 1-octadecanol-filled HrGOT phase change composite (PCC) with a latent heat of 262.5 J g-1 is obtained. This high latent heat results from the interfacial interaction between 1-octadecanol and the reduced graphene oxide tube, as evidenced by the shifts in XRD patterns of 1-octadecanol-filled and 1-octadecanol/multiwalled carbon nanotube-filled HrGOTA samples. In addition, 1 wt % multiwalled carbon nanotubes are added to the PCC to enhance visible light absorption. Because of their high thermal conductivity and visible light absorption rates, these new PCCs display high solar-thermal energy conversion and storage efficiencies of up to 81.7%, commensurate with state-of-the-art carbon-based PCCs but with significantly lower carbon weight percentages.

Application of advanced correlative approaches to modeling hydrogen solubility in hydrocarbon fuels

In petroleum and petrochemical refineries, having precise knowledge regarding H2 solubility in hydrocarbon fuels and feedstocks is critical. In this study, the hydrogen solubility in hydrocarbon fuels was estimated using genetic programming (GP) and group method of data handling (GMDH), two exemplary robust advanced models for generating correlation. To do this, 445 observations derived from labratory findings on hydrogen solubility in 17 different hydrocarbon fuels such as bitumen, atmospheric residue, heavy coking gas oil, heavy virgin gas oil, light virgin gas oil, straight run gas oil, shale fuel oil, dephenolated shale fuel oil, diesel, hydrogenated coal liquid, coal liquid, and coal oil, over a large interval of P- operating pressures and T-temperatures were collected. Temperature, pressure, as well as density at 20 °C, molecular weight, and weight percentage of carbon (C) and hydrogen (H) in hydrocarbon fuels, were used as input parameters in developing robust correlations. The outcomes showed the GMDH approach is more precise compared to the GP, with a root mean square error (RMSE) of 0.053302 and a determination coefficient (R2) of 0.9641. Additionally, sensitivity analysis showed that pressure, followed by temperature and H (wt%) of hydrocarbon fuels, has the greatest impact on hydrogen solubility in hydrocarbon fuels. Ultimately, the Leverage method's results suggested that the GMDH model could be relied on to predict hydrogen solubility in hydrocarbon fuels.

Optimization Studies of Elemental Composition of Composite Polymer for Neutron Shielding Using Factorial Design Analysis

The present study is envisaged with an aim to highlight a novel approach of applying the statistical factorial design analysis (FDA) technique in radiation shielding design. In FDA, the estimated total dose rate (TDR) and concentration of elements in shielding material are termed as “Response” and “Factors.” The impact on the response due to the change in the level of factors is defined as “Effects.” Monte Carlo simulation (MCS) is performed using the MCNP4A code to compute the surface TDRs due to the coupled neutron-gamma field arising from the 740-GBq 241Am-Be source housed inside a shielding container made of composite polymer (CP). The composition of CP is hydrogen, carbon, and oxygen with lead and natural boron as fillers. In the present work, the weight percent of hydrogen, carbon, and lead is optimized in the CP by minimizing the surface TDR at the exit of the shield, and a proposed CP (PCP) is obtained. For the first time, a detailed regression analysis is performed to develop a model linking TDR and the three factors, namely, hydrogen weight percent, carbon weight percent, and lead weight percent. Three levels of each factor are considered, and the impact due to the linear, quadratic, and interaction effects of the factors that influences the TDR is investigated using Student’s t-test analysis. The results from the statistical analysis indicate that the weight percent of hydrogen and lead have a greater influence on TDR. The interaction effects arising out of the combination of hydrogen, carbon, and lead are observed to be negligible. Hence, the regression model is modified by dropping the statistically insignificant terms from the equation, and the new model has shown excellent correlation within ±1% of the estimated TDRs using MCS. The R2 and R2 Adj values are found to be 0.99970 and 0.99966, which explains the computation power of the model. The model can be applied to compute the TDRs for any combinations of factors within the range of variability as studied in the present work. The shielding container made of PCP obtained from the present study provides a minimum of 20% reduction in volume and mass compared to the conventional high-density polyethylene and other polymer-based materials.

Microscopy and image analysis of the micro-fabric and composition of saline rocks under different phaseCO2-Brine states

Using different phaseCO2-brine, the effect of stress corrosion on the micro-fabric, topology of the minerals and the elemental composition of saline rock was evaluated, to understand how this affect transport properties of rocks. Image analysis was used to evaluate changes in micro-fabric, topology of mineral and elemental composition from SEM images. The micro-fabric of all the CO2 bearing samples changed significantly according to the different phaseCO2-brine. Grain roundness, grain smoothness, and pore smoothness increased after compression while the roundness of pores reduced. There was a significant change in the weight percentage of silicon, carbon and oxygen in the CO2-bearing samples compared to the brine sample. Change in the shape, solidity and roundness of the pores led to a change in permeability of rocks by altering the tortuosity of the pores. This study provides an understanding of changes in micro-fabric and elemental changes occurring in saline CO2 storage sites under different possible phaseCO2-brine and highlights their implication for storage and properties of the rock.

Tribological and mechanical properties of banana peel hybrid composite for brake-pad application

The drawbacks of conventional materials over the years had brought health issues and new innovated materials that is environmentally friendly and non-toxic needs to be developed. The importance of braking system has come into limelight recently due to the continuous growth and dynamics of 21st century vehicles. Reliable wear and frictional properties, and stability are some of the qualities that brake pads materials should possess under varying conditions of velocity, load, high durability and temperature. This research is aimed of developing non-toxic and environmentally friendly banana peel composite with enhanced mechanical properties. The produced composites were mixed with carbon powders, epoxy and hardener in predetermined ratios. The results showed that the produced banana peel composite can compete favourably with the existing conventional materials in mechanical properties and extended applications. Composition 1 experienced minimal loss of weight. The same composition 1 gave us the highest strength of 2.1 MPa and 13.0 elongation. The influence of the strength on the weight differentials was well noted. Composition 1 has the minimum waste banana peel weight percent and highest carbon powder. Composition 1 with minimal loss of weight would be applicable for the brake pad application. It is equivalent to 60% weight differentials in composition 2 compared to composition 1. While 67.7% weight differentials were experienced in composition 3 compared to composition 1.

Mechanical and thermal properties of plasma irradiated GO/Glass fibre/epoxy hybrid composite

Thermo-mechanical properties of glass fibre based polymer (GFRP) composites play a vital role on achieving ultimate curing property for light-weight corrosion-free applications. Plasma radiation containing ions, charge particles and neutral atoms can penetrate up to certain depths of polymer composite resulting in improvement in post-curing strengthening. Also, incorporation of few weight percent of carbon based nano fillers can cause increase in interfacial properties up to considerable extent. Keeping this in mind, the present work is approached to fabricate conventional glass fibre/epoxy and graphene oxide (0.5 wt%) filled glass fibre/epoxy (GO/Glass Fibre/Epoxy) hybrid composite and to treat such sample to plasma radiation. Graphene oxide (GO) powder was synthesized by modified Hummer’s method. The as-synthesized GO was confirmed through XRD and Raman spectroscopy. Both the composites were exposed to plasma irradiation (30 W) for 5, 10, 15, 20, 25 and 30 min. Inter laminar shear strength (ILSS) values were determined through 3-point bend test of the irradiated composite specimens. With increase in plasma treatment periods, ILSS was increased with higher rate for GO/Glass Fibre/Epoxy composite. Low temperature differential scanning calorimetry (DSC) test of the plasma irradiated composites reveals increase in glass transition temperature (Tg) values with increase in plasma irradiation periods. Tg is found maximum for GO/Glass Fibre/Epoxy composite at 25 min of plasma irradiation. SEM fractograph of both the composite specimens reveals various types of failure modes. In the fractographic image of plasma treated GO/Glass Fibre/Epoxy composite, adequate extent of interfacial adhesion between GO and epoxy resin was observed.

Application of robust machine learning methods to modeling hydrogen solubility in hydrocarbon fuels

Having accurate information about the hydrogen solubility in hydrocarbon fuels and feedstocks is very important in petroleum refineries and coal processing plants. In the present work, extreme gradient boosting (XGBoost), multi-layer perceptron (MLP) trained with Levenberg–Marquardt (LM) algorithm, adaptive boosting support vector regression (AdaBoost−SVR), and a memory-efficient gradient boosting tree system on adaptive compact distributions (LiteMORT) as four novel machine learning methods were used for estimating the hydrogen solubility in hydrocarbon fuels. To achieve this goal, a database containing 445 experimental data of hydrogen solubilities in 17 various hydrocarbon fuels/feedstocks was collected in wide-spread ranges of operating pressures and temperatures. These hydrocarbon fuels include petroleum fractions, refinery products, coal liquids, bitumen, and shale oil. Input parameters of the models are temperature and pressure along with density at 20 °C, molecular weight, and weight percentage of carbon (C) and hydrogen (H) of hydrocarbon fuels. XGBoost showed the highest accuracy compared to the other models with an overall mean absolute percent relative error of 1.41% and coefficient of determination (R2) of 0.9998. Also, seven equations of state (EOSs) were used to predict hydrogen solubilities in hydrocarbon fuels. The 2- and 3-parameter Soave-Redlich-Kwong EOS rendered the best estimates for hydrogen solubilities among the EOSs. Moreover, sensitivity analysis indicated that pressure owns the highest influence on hydrogen solubilities in hydrocarbon fuels and then temperature and hydrogen weight percent of the hydrocarbon fuels are ranked, respectively. Finally, Leverage approach results exhibited that the XGBoost model could be well trusted to estimate the hydrogen solubility in hydrocarbon fuels.

Physicochemical Changes of Contaminated Titanium Discs Treated With Erbium-Doped Yttrium Aluminum Garnet (Er:YAG) Laser Irradiation or Air-Flow Abrasion: An In Vitro Study.

Introduction: Peri-implantitis is a common complication of dental implant treatment. A cause-and-effect relationship has been previously documented between microbial plaque and peri-implantitis and implant failure. A difference has been reported in the disinfection efficacy of erbium laser irradiation and air-flow abrasion for contaminated titanium surfaces. Also, the surface changes caused by lasers and air-flow abrasion have not been well studied. Thus, the purpose of this study was to compare the surface changes of contaminated titanium discs following decontamination by erbium-doped yttrium aluminum garnet (Er:YAG) laser irradiation and air-flow abrasion. Methods: Twenty-eight intact, sandblasted, and acid-etched (SLA) titanium discs were used. Twenty-four titanium discs were contaminated with Escherichia coli. Then, they were decontaminated by using Er:YAG laser irradiation and air-flow abrasion. Four discs remained intact. The mean and standard deviation of the contact angle and the weight percentage of aluminum, titanium, oxygen, carbon, phosphorus, and calcium were measured. Qualitative changes in surface topography of titanium discs were assessed by scanning electron microscopy (SEM). Results: The mean weight percentage of carbon in the air-flow abrasion group (4.98%) experienced a significant reduction compared with the contaminated (positive control) group (P=0.035). The contact angles were 46.54° and 38.67° in the laser and air-flow abrasion groups respectively, which were significantly lower than the value in the positive control group (75.15°) (P ≤0.001). SEM micrographs showed no significant change in the surface area in either technique. Conclusion: Air-flow abrasion was more successful in improving the surface characteristics of titanium discs with no alteration in surface topography or elements, compared with Er:YAG laser irradiation. Further studies regarding the safety of the Er:YAG laser for the decontamination of titanium surfaces are recommended.

Characteristics of Organic Macerals and Their Influence on Hydrocarbon Generation and Storage: A Case Study of Continental Shale of the Yanchang Formation from the Ordos Basin, China

Organic macerals are the basic components of organic matter and play an important role in determining the hydrocarbon generation capacity of source rock. In this paper, organic geochemical analysis of shale in the Chang 7 member of the Yanchang Formation was carried out to evaluate the availability of source rock. The different organic macerals were effectively identified, and the differences in hydrocarbon generation and pore-forming capacities were discussed from two perspectives: microscopic pore development and macroscopic hydrocarbon generation through field emission scanning electron microscopy (FE-SEM) and energy-dispersive spectrum (EDS) analyses, methane isotherm adsorption, and on-site analysis of gas-bearing properties. The results show that the source rock of the Chang 7 member has a high abundance of organic matter and moderate thermal evolution and that the organic matter type is mainly type I. Based on the morphology of the organic matter and the element and pore development, four types of hydrogen-rich macerals, including sapropelite and exinite, and hydrogen-poor macerals, including vitrinite and inertinite, as well as the submacerals, algae, mineral asphalt matrix, sporophyte, resin, semifusinite, inertodetrinite, provitrinite, euvitrinite, and vitrodetrinite, can be identified through FE-SEM and EDS. A large number of honeycomb-shaped pores develop in sapropelite, and round-elliptical stomata develop in exinite, while vitrinite and inertinite do not develop organic matter pores. The hydrogen-rich maceral is the main component of organic macerals in the Chang 7 member of the Yanchang Formation. The weight percentage of carbon is low, so it has good hydrocarbon generation capacity, and the organic matter pores are developed and contribute 97% of the organic matter porosity, which is conducive to hydrocarbon generation and storage. The amount of hydrogen-poor maceral is low, and the weight percentage of carbon is low, and the organic matter pores are not developed, which is not conducive to hydrocarbon generation and storage.

Polypropylene hybrid composites: Effect of reinforcement of sisal and carbon fibre on mechanical, thermal and morphological properties

Abstract Polypropylene (PP)/sisal fibre (SF)/carbon fibre (CF) hybrid composites were prepared by melt blending process at a variable weight percentage (wt%) of carbon: sisal fibre loading (20:10, 15:15, 10:20, and 5:25). MA-g-PP (MgP) as a compatibiliser was used to improve the dispersion of the fibres within the PP matrix. The composites were subjected to mechanical tests to optimize the fibre content of CF: SF. Incorporation of 20 wt% of CF and 10 wt% of SF with 5 wt% MgP resulted in higher mechanical performance of about 67.02 and 112% over that of PP/SF composite. Similarly, the impact strength was found to be optimum which enhanced to the tune of 39.62% as compared with PP/SF composites. Halpin Tsai model was used to compare the theoretical tensile modulus of PP/SF/MgP composites and PP/SF/CF/MgP hybrid composites with experimental evaluated values. Fracture toughness parameters such as K IC (critical stress intensity factor) and G IC (critical strain energy release rate) are determined for PP/SF/MgP composites and PP/SF/CF/MgP hybrid composites and compared by using single edge notch test. DSC study showed higher melting temperature (T m ) of PP/SF/CF/MgP composites as compared to PP revealing the enhancement in thermal stability. TGA/DTG study revealed the synergistic effect of the hybrid composite thus confirming the hybridisation effect of the system. DMA study showed that the hybridisation of CF and SF within the matrix polymer contributes to an increase in the storage modulus (Eʹ). Morphological observation by SEM confirmed that the carbon fibres and sisal fibres are well uniformly dispersed within the PP matrix, in the presence of MgP.

Low-pressure flame synthesis of carbon-stabilized TiO2-II (srilankite) nanoparticles

Nanoparticulate (3–10 nm) TiO2 polymorphs, i.e., rutile, anatase, and srilankite (also known as TiO2-II or α-PbO2-type TiO2) phases are produced via low-pressure (e.g., 20 torr) flame synthesis at temperatures ranging from 1560K to 2650K, with burner flow velocities varying from 150 to 300 cm/s, using titanium tetra-isopropoxide (TTIP) as precursor. Interestingly, added carbon (i.e., ethylene) in the feed stream produces nanoparticles of the generally characteristic low-temperature high-pressure metastable srilankite phase. The as-synthesized nanopowder is composed of either rutile or srilankite phase, with composition dependent on particle residence time in the flow field. Under the same conditions, feed gas without carbon, e.g., hydrogen, yields anatase phase TiO2. Post heat treatment up to 773K in thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) highlights the thermal stability of the samples, while x-ray photoelectron spectroscopy (XPS) indicates the presence of carbon, with absences of Ti3+, Ti–C, and nitrogen. Microscopy reveals morphology on both the micrometer scale (scanning electron microscopy, SEM) and nanometer scale (transmission electron microscopy, TEM), while x-ray diffraction (XRD) and selected area electron diffraction (SAED) confirm polymorph variation under different synthesis conditions. CHN analysis determines that the synthesized srilankite contains a greater weight percentage of carbon than does anatase. Excess carbon doped into the lattice during low-pressure flame synthesis seems to be the key in stabilizing the high-pressure srilankite phase for such nanoparticles.

Impact of torrefaction conditions on the physicochemical properties of mustard crop residue

Abstract Torrefaction process is related to pyrolysis treatment in an inert atmosphere which is employed to improve the chemical and physical properties of biomass/solid fuels for energy generation. In present study, mustard crop residue (MCR) which is an abundantly available lignocellulosic waste was torrefied at three different temperatures (200 °C, 250 °C, and 300 °C) for three different residence time (30, 45, and 60 min). Mass yield, energy yield, high heating value, elemental composition, ash content, and volatile matter content of raw and torrefied MCR are computed. The functional behavior and combustion characteristics of raw and torrefied MCR was studied by Fourier Transform Infra-Red Spectrometry (FTIR). The mass and energy yield of torrefied MCR were found to decrease with an increase in torrefaction temperature and residence time. Elemental analysis of torrefied MCR showed an increase in weight percentage of carbon with increase in temperature and residence time of torrefaction due to release of oxygen congaing volatiles. The high heating value was found to upgrade from 16.92 MJ kg−1 for raw MCR to 21.93 MJ kg−1 of torrefied MCR at higher torrefaction temperature and time. FTIR analysis confirmed that hydroxyl group content decreased due to release of H2O, CO, and CO2. Therefore, torrefaction is found to be an effective treatment process for improving physicochemical properties of MCR.

Performance analysis of Cu-W-B4C composite tool during electrical discharge machining of titanium alloy

Electrical discharge machining (EDM) is broadly used in machining of parts having intricate shapes made of difficult-to-machine materials. During EDM, tool fabrication time through conventional machining processes is generally excessively high. Therefore, alternate tool material and fabrication strategy is sought to reduce machining lead time. In this work, composite tools made of copper, tungsten and boron carbide have been prepared through powder metallurgy (PM) route. The performance of these tools is studied during machining of titanium alloy work piece. The input parameter considered are tool material parameters such as weight percentage of tungsten and boron carbide in the tool and machining parameters like peak current, pulse-on-time and duty cycle. The performance of these tools are evaluated considering the performance measures such as material removal rate (MRR), tool wear rate (TWR), average surface roughness (Ra), surface crack density (SCD), white layer thickness (WLT) and micro-hardness (MH). It is observed that the tool materials have been transferred onto the machined surface forming a hard layer with increased weight percentage of oxygen and carbon during machining. The PM tools exhibit similar performance as solid copper tool with respect to MRR, TWR and surface integrity.