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This study is part of a broad research to develop advanced composite material through the incorporation of nanofillers. Focusing in this article on dynamic mechanical and thermal properties, alongside charge density measurements. Evaluating a composite comprising of polyesterimide resin matrix filled with 1 wt.% silicon dioxide (SiO₂) nanoparticles, supplemented with polyamide nonwoven nanofabric and polyamide film. Dynamic Mechanical Analysis (DMA) is employed to assess the viscoelastic behavior, stiffness, and damping properties of the composite under various mechanical stresses and temperatures. Simultaneous Thermal Analysis (STA) is conducted to evaluate the thermal stability and decomposition characteristics, which are essential for applications exposed to high temperatures. Charge density within the composite is measured using the Pulsed Electroacoustic (PEA) method, essential for analyzing the electrical charge distribution under electrical stress. Results indicate notable enhancements in mechanical damping and thermal stability. The use of an environmentally friendly, low-viscosity polyesterimide resin not only facilitates the manufacturing process but also improves the performance of the composite, positioning it as a viable alternative to traditional materials in demanding mechanical, thermal, and electrical applications. The synergistic effects of the nanoparticle and nanofabric reinforcement on the overall properties of the composite are highlighted, showcasing its potential for future use in high-performance engineering applications. [ABSTRACT FROM AUTHOR]

Study focuses on the measurement of thermal conductivity in polyurethane (VUKOL Magna blue) containing varying proportions of aluminum nitride nanoparticles (10%, 20% and 50%). The incorporation of nanoparticles into polyurethane matrices holds promise for enhancing thermal properties and extending potential applications in fields such as thermal insulation and heat management. By systematically altering the nanoparticle concentration, the thermal conductivity of the composite materials was investigated. Experimental measurements were conducted using plane heating element, two thermistors for temperature measurement and developed electronics for data acquisition. The setup for measuring the thermal conductivity of polyurethane composites with various admixtures of aluminum nitride nanoparticles is described and results are discussed. [ABSTRACT FROM AUTHOR]

Geopolymer concrete is gaining prominence as a viable substitute for conventional cement concrete within the construction sector, offering potential benefits for reducing carbon footprint. However, extensive research is needed to fully understand its properties and mechanisms. This study investigates the use of bagasse ash in GPC production, assessing the possibility of incorporating Sugarcane ash as a component. Casts of geopolymer concrete were formed, and an assessment was conducted to evaluate both their fresh and hardened characteristics. The research aims to determine the optimal balance between workability and strength parameters while minimizing the utilization of Ground Granulated Blast Furnace Slag (GGBS). Aura mix super plasticizer was employed to enhance GPC's workability. After 28 days of sun curing, the findings indicated a positive impact with a maximum replacement of 30 percent of bagasse ash. However, more increments resulted in a reduction in hardness properties compared to standard concrete. The study highlights the importance of optimizing the replacement ratio to achieve a balance between environmental benefits and structural integrity. [ABSTRACT FROM AUTHOR]

Magnetorheological (MR) grease is one of the smart materials that owing excellent properties that can be altered and changed significantly with the presence of a magnetic field. However, thermal stability of MR grease is one of the crucial issues that restricted the efficiency of MR grease in MR applications since the induced heat to the material would affect the resultant properties of the material. In this study, the thermal behavior of MR grease with 1wt.% of cobalt-ferrite (CoFe2O4) were analyzed. The CoFe2O4 particles was synthesized via co-precipitation method. The synthesized particles were characterized in terms of morphological by using field Emission scanning electron microscope (FESEM) and magnetic properties by Vibrating Sample Magnetometer (VSM). Then, the synthesized particles were mixed with grease and carbonyl iron particles (CIPs) by using a mechanical stirrer. The thermal properties of the MR grease samples in terms of conductivity were tested by using KD2Pro. Additionally, rheometer was used to examine the MR effect of MR grease under magnetic field sweep at different applied temperatures. The results showed that the synthesized particles formed in polygonal shape with 68.9 emu/g meanwhile CIPs are in spherical shape with 125 emu/g of magnetic saturation, Ms. Moreover, the thermal conductivity of MR grease increased as the temperature increased, particularly with presence of CoFe2O4 due to the Brownian motion by 178.69%, at 65°C. The storage modulus of the MR grease samples also showed an increasing trend with the addition of CoFe2O4 and with the magnetic field intensity increased, although the induced temperature also increased. [ABSTRACT FROM AUTHOR]

The electrical output of solar absorbers like monocrystalline photovoltaic (PV) panels besides the solar irradiance, heavily rely on the operating temperature within the environment. This work investigates an innovative cooling technique to mitigate the detrimental impact of temperature rise on PV panel performance, especially in a temperate region. Nanocoolants have higher thermal conductivity than conventional fluid, hence the effect of its good thermal properties was investigated to observe its influence on the electrical performance of the PV panels. The work involved numerical analysis using the commercial code ANSYS. The Multiphysics approach begins with the steady state analysis and then CFD to observe the thermal flow behaviours of the different components making the panels. The simulation considered three different PV arrangements, the uncooled, the nano-cooled and the water-cooled panels. The panel's surface was exposed to solar irradiance of 650 W/m2 and the operating temperature of 40°. The result found that Al2O3-water nanofluid as a cooling agent by spraying on the solar panel module at the velocity of 0.01m/s can decrease the temperature of the solar panel from 73.85 °C to 35.95 °C. Hence utilization of Nanocoolant for cooling of PV has a good potential in electrical performance enhancement. [ABSTRACT FROM AUTHOR]

The research work is investigating of sintering behavior of ZrO2−TiO2−Al2O3 Ternary system, the composite was prepared by precipitation of hydroxides from their water soluble salts followed by calcinations and sintering, the sintering behavior studied in 1:1:1 mole ratio of ZrO2, TiO2, Al2O3 between 1550°C to 1600°C. Densification depends on the function of temperature and MgO addition. It shows in significant change in densification as well as micro-structure development upto a 1mole percentage. XRD study showed that MgO addition facilitated the stabilization of tetragonal and cubic zirconia together with aluminum-titanate and Magnesio-aluminate with a dense microstructure. This Ternary system we used to mention as composite in the proceeding orders to understand clearly and this composite (Ternary system) was used at High temperature applications, it resists to mechanical (erosion) and chemical attack and thermal properties. The role of MgO in matrix is stabilized the zirconia. The result is expected to develop the formation of MgAl2O4 spinel phase and ZrTiO4 spinel phase and produce the cubic-zirconia phase with alumina Titania reinforcement. [ABSTRACT FROM AUTHOR]

Electronic and thermal properties of rare-earth chalcogenide compounds R2X3 (R = Dy/Tb and X = S/Se) are investigated using Density Functional Theory. The effective mass, deformation potential and elastic constants are calculated. The rare-earth chalcogenide compounds are dynamically stable. The lattice thermal conductivity for these compounds is calculated using slack model. The lowest value of kl 4.5W/mK is obtained for Tb2Se3 This low thermal conductivity of these compounds can have several application in various fields like thermoelectric, thermal insulation and phononics. [ABSTRACT FROM AUTHOR]

Ceramic materials based on the composition 0.98(Na0.5K0.5NbO3) + 0.02(Sr Bi0.5Nb0.5O3) + x ZnO (x=0.0, 0.45) have been synthesized through a solid-state reaction method and characterized to explore their unique properties and potential applications. In this study, we investigated the influence of varying " x wt% ZnO values on the physical, electrical, and structural characteristics of Na-K-Nb-O and Sr-Bi-Nb-O matrix (coded as NKBN) ceramics. Our findings show that the dielectric characteristics of the NKBN ceramics are significantly affected by the addition of ZnO to the ceramics. We noticed differences in the dielectric constant and dielectric loss depending on the ZnO doping. Additionally, the crystal structure and microstructure of the ceramics were revealed through structural analysis utilising methods including X-ray diffraction and scanning electron microscopy, which had an impact on their mechanical and thermal properties. With rising frequency and temperature, it was found that the dielectric characteristics decreased, which showed that the samples' conductivity had increased. The change in dielectric behavior were observed and confirmed from the dielectric study of the samples for electronic application. [ABSTRACT FROM AUTHOR]

Using the ab-initio FP-LAPW technique, the structural and thermal characteristics of V3Si are investigated. The equilibrium structural parameters and the formation enthalpy obtained are in good agreement with the results of the existing experimental and theoretical data. To determine the internal energy, Helmholtz free energy, entropy, heat capacity at constant volume and pressure, Grüneisen parameter, thermal expansion coefficient and Debye temperature of V3Si, the ab-initio total energy calculations are linked with the second-generation software Gibbs2. It employs the Debye Slater and Debye Grüneisen models. The existing experimental and theoretical data are in accord with all of the current findings. [ABSTRACT FROM AUTHOR]

Utilizing the D-Optimal Mixture in Design of Experiments (DOE) software, this investigation aimed to create a composite of recycled polypropylene-reinforced oil palm vacant fruit bunches and fly ash. The formulation was derived by employing many ratios based on the data collected through the utilization of Design of Experiments (DOE) software. The thermal properties of twenty formulations were compared by analyzing their reaction by Thermogravimetric Analysis (TGA). The residue remaining, also known as ash content, was utilized as a criterion for selecting the optimal formulation ratio. This study endeavors focused on investigating the feasibility of achieving optimal flame-retardant composite formulations through the precise blending of appropriate ratios. Thermogravimetric Analysis (TGA) was employed to acquire the thermal characteristics. The temperature of the thermogravimetric analysis (TGA) was recorded within the range of 25°C to 900°C, employing a heating rate of 10°C/min and utilizing nitrogen gas as the medium. The formulation of the composite was determined by utilizing Design of Experiment (DOE) software to analyze its thermal response. This formulation enhances the thermal breakdown of pure recycled polypropylene, resulting in a 50% increase in ash residual content. The thermal degradation loss rate is observed to decrease from 152.40°C to 95.34°C. The formulation of recycled polypropylene reinforced with oil palm empty fruit bunch (OPEFB) and fly ash (FA) for enhancing thermal properties is considered to possess promising potential as a substitute for synthetic fibers in the context of building insulation. [ABSTRACT FROM AUTHOR]

This paper presents an optimization of the Al2O3/distilled water-based nanofluid process parameters for enhancing its thermal conductivity. Nanoparticle volume concentration, nanoparticle size, sonication time, stirring time, and surfactant volume concentration are selected as optimization factors to obtain higher thermal conductivity. Eighteen different nanofluid samples having various preparation parameters are determined and prepared as per the Taguchi orthogonal array. Thermal conductivity was measured using the KD2 Pro thermal properties analyzer at a working temperature of 28 °C. To study the structure and crystallite size of alumina nanoparticles, we used X-ray diffraction. A scanning electron microscope is used to investigate the morphology and size of Al2O3 nanoparticles. To assess the effect of each parameter on thermal conductivity, the main effect plot for means and the signal-to-noise ratio are utilized. The statistical contribution percentage of each parameter on thermal conductivity is determined using an analysis of variance. The signal-to-noise ratio demonstrated that the nanoparticle concentration in a base fluid is the most affecting parameter, with a delta value of 0.715. Furthermore, with delta values of 0.461, 0.413, 0.272, and 0.177, the stirring time, sonication time, surfactant concentration, and nanoparticle size all play significant roles in nanofluid thermal conductivity. The outcome of the analysis of variance shows that the nanoparticle concentration in the base fluid has the most significant impact on the thermal conductivity of the nanofluid with a contribution of 36.64%, whereas initial stirring has a contribution of 26.82% and sonication time has a contribution of 19.76%, while surfactant concentration has an 8.83% contribution and nanoparticle size has a less significant contribution with a 4.06% contribution on the thermal conductivity of the nanofluid. The obtained results indicate that the thermal conductivity of the Al2O3/distilled water-based nanofluid increased by 7.146% compared to the base fluid, i.e., distilled water. The optimum thermal conductivity is obtained as 0.640732 W/m-K at optimum parameter settings of 0.3% of nanoparticle concentration, with a nanoparticle size of 50 nm, 40 minutes of sonication time, and 10 minutes of initial stirring time with 0.2% of surfactant concentration, A confirmation test with optimized parameters was finally carried out to ensure the method's confidence. [ABSTRACT FROM AUTHOR]

Now-a-days technologists are more interested opted as one of the prime research in the natural fibers in order to save the entire eco system. In this reason behind, technologists doing vigorous materials characterization on newly available natural fibers and find out the newer natural fibers to increase the increasing demand on the materials science. Since natural fibers are abundantly available in nature, as well processing and disposable after use also would not affect the eco system as such observed in the synthetic fibers, because of this reason natural fibers are widely opted for various purposes. Moreover, plant are rich in fibers and easily cultivated throughout the year, apart from that it has the better weight to stiffness ratio and not hazardous to human health. Besides, natural fibres provide enhanced thermal and acoustic wadding as compared to synthetic fibers. Additionally, fibers gotten from the numerous plants are processed and mixed with (Reinforced) various set of matrix materials to enhance their physical and thermal properties. This current research article examines various natural fibers material currently being used in the industry and their current eminence in the specific research activity. [ABSTRACT FROM AUTHOR]

Composites prepared by Friction stir processing (FSP), having exceptional surface characteristics, are being widely used in various thermal environments, such as in automobiles and aircraft industries. The addition of one or more ceramic reinforcements may improve their thermal conductivities and reduce the thermal expansion coefficients leading to greater dimensional stability thereby making them more efficient for such applications. In the present work, FSP is utilized to fabricate surface composites with varying compositions of copper and graphene powders as the reinforcements. The composites prepared are inspected for their thermal and microstructural characteristics for different reinforcement compositions and FSP pass numbers. It is observed that the composites with higher copper weight% have higher thermal expansion coefficient in comparison to that with lower copper weight%. Also, the addition of higher graphene content in the aluminium alloys lowers the coefficient of thermal expansion (CTE) of the composite and vice-versa. Besides, the composites prepared by lesser number of passes (two) have higher values of CTE than that prepared by higher number of passes (four). This is due to the reason that the microstructure of the composite is more refined when prepared with more pass numbers and so the space between the particles is lesser preventing the tendency of the sample to be easily be expanded on heating. This approach finds a wide scope to draw useful insights for the composite fabrication conditions for their high temperature applications. [ABSTRACT FROM AUTHOR]

The article is focused on studying Fused Filament Fabrication (FFF) of alumina-filled polymer objects and their thermal properties. To track influence of inclusion type on thermal diffusivity of 3D printed samples with equiaxed and needle-like Al2O3 particles were made. The difference between the microstructure of needle and equiaxed compositions was evaluated using Phenom G2Pro (Phenom-World BV, Eindhoven, The Netherlands). The tests of thermal diffusivity were carried out on LFA 467 HT HyperFlash setup (NETZSCH Inc., Germany). It was found that the addition of 20 vol. % of ceramic particles in polyamide (PA12) increases its thermal conductivity, and the shape and location of inclusions play an important role in heat flow processes. It is shown that specimens with alumina needle-like inclusions demonstrated the highest values of thermal diffusivity. [ABSTRACT FROM AUTHOR]

The bio-heat equation is a popular tool for determining how heat is distributed in living organisms. Moreover, the Pennes bio-heat equation is crucial in the field of ablation therapy computation. Using the finite element approach, we investigated the stability criteria for the bio-heat equation in this article. In a semi-discretized finite element formulation, first-order difference techniques are employed to discretize the time derivative term. When the implicit scheme is replaced with the explicit scheme, the time step becomes reliant on the thermal properties of the tissue and the eigenvalue of the global matrix. [ABSTRACT FROM AUTHOR]

Measurement and assessment of thermo-physical properties of magnesium oxychloride cement (MOC) with implemented phase change material based on paraffin wax encapsulated in polymer shell, is presented in the paper. The measurement method and mathematical interpretation of thermal conductivity and specific heat capacity assessment was derived from the Thermophysical Transient Tester 1.02 that was developed at the Institute of Physics, Slovak Academy of Sciences. Within the test, thermal responses between two thermal sources were measured during the step wise heat reference source and source generating step wise heat. It was revealed that both investigated thermal parameters depend on the dosage of PCM in composite mixture, thus porosity of prepared materials and thermal characteristics of PCM itself. The obtained data point to the substantial improvement of heat storage capacity of MOC by the use of powdered PCM. [ABSTRACT FROM AUTHOR]

Although the term of women leadership sound familiar due to its significance on achieving gender equality in all nations, however lack of evidence was found on this domain particularly in the context of Malaysia. Following that, this research aims to examine the associations between personality, work-life balance (WLB) and emotional intelligence (EI) towards women leadership, specifically in the Malaysian manufacturing-based industry. A total of 391 out of 1846 engineers from the Malaysian manufacturing-based companies filled out questionnaires. SPSS was used to analyse the associations between all variables. Also, the mean for all variables were reported in this research. Specifically, a high mean indication with µ=4.02 for women leadership; µ=3.96 for personality; µ=3.85 for WLB; and µ=4.10 for EI were revealed based on this research. Next, Pearson correlation results presented the highest association between WLB and women leadership (r=.737, p=.000); followed by personality (r=.724, p=.000); and EI (r=.722, p=.000). This research added new information to the existing literature by empirically tested the role of personality, WLB and EI on women leadership. Thus, by nurturing the proven indicators of polishing the women engineers to be leaders in the manufacturing-based companies, the goal of gender equality for the country was expected can be achieved. [ABSTRACT FROM AUTHOR]

Biomass is widely recognized as an essential source of renewable energy. The most abundant organic resources in the plantation field are oil palm frond (OPF) and trunk (OPT). These lignocellulose biomaterials are rich in renewable biobased products. The recalcitrance of oil palm biomass directly linked with the cellulose, hemicellulose, and lignin structure remains a challenge. The pretreatment process is still a consideration because the recalcitrant lignocellulose structure prevents depolymerization from releasing the appropriate substrate to a new approach. This study is aimed to characterize the oil palm frond and trunk pretreated by a combination of ultrasonication with a dilute sulfuric acid medium. This study considers the morphological and thermal characteristics intending to explore their future potential application. The procedure in this research was that the raw OPF and OPT were weighed and transferred into a 1000 ml beaker containing a low acid concentration of H2SO4 in the ratio of 1: 25. The deionized water (DW) was used as a control. The mixture was stirred and incubated in an ultrasonic bath for 30 minutes at an ultrasonic frequency of 40 kHz and an ambient temperature of 80°C. The operating time and power were set at the start of the pretreatment. The ultrasonicated materials were characterized by Scanning Electron Microscope (SEM) and Thermogravimetric Analysis (TG-STA). The results demonstrated that the yield percentages of OPT's ultrasound-assisted low sulfuric acid (ULSA) are about 10% higher than the deionized water pretreatment. SEM results showed that the ULSA pretreatment of OPF and OPT revealed a significant disruption of their surface structures. The DTG analysis revealed that the maximum temperature degradation of ULSA pretreatment is shifted to a higher temperature than the raw material, which is 273.43℃ for OPF and 265.15 for OPT to 314.43℃ for ULSA-OPF (SOPF) and 318.88℃ ULSA-OPT (SOPT). The thermogravimetric data indicates that the ULSA pretreatment produced more thermal stability than untreated oil palm biomass. Thermal stability is an essential criterion for determining the best lignocellulose material for a particular application, including energy. Hence, ultrasound coupled with the low sulfuric acid medium in both oil palm frond and the trunk has potential as a renewable material for use in many future applications of the bio-based material. [ABSTRACT FROM AUTHOR]

Gelling polymers, used for the fabrication of hydrogels, are employed for various applications in medical engineering. The present paper explores a novel approach for the additive manufacturing of polypropylene-hydrogel composites by applying laser-based powder bed fusion of powder blends at ambient temperatures, hence allowing for the integration of additives sensitive to heat degradation. Based on applying superposed fractal exposure strategies for the temporally and spatially discretized melting of prepared powder blends, the processing of composites containing a proportion of up to 75% of agarose can be demonstrated. Prepared specimens depict a water absorption exceeding 100 wt-% while exhibiting non-linear, progressive mechanical properties under compressive stress and enhanced stress relaxation similar to human cartilage tissue. The results illustrate the suitability of fractal exposure strategies for the processing of materials sensitive to heat degradation with divergent thermal properties. Furthermore, the proposed approach provides a novel process route for the fabrication of functionalized polymer components, representing a foundation for the integration of hydrogels for medical applications, such as drug delivery applications and functionalized, load-bearing scaffolds. [ABSTRACT FROM AUTHOR]

Thermoplastic over-extrusion is a continuous production process in which reinforcing UD-fibers are preheated and guided at constant line speed into an extrusion die. Here the fibers are surrounded by molten polymer. After the extrusion die, the composite is cooled by a combination of calibration units and water baths. At the end of the process line, the parts are cut to length. Products made with this process have a (or multiple) reinforced zone(s) in their cross-section, allowing for improved mechanical performance with a minimum of reinforcing materials when strategically located. However, due to the mismatch in coefficient of thermal expansion between the reinforcing fibers and the surrounding polymer, excessive warpage and residual stresses after cooldown are often present in the final products. Reducing these unwanted effects is currently done by a costly and lengthy trial-and-error approach. This study presents a multiphysics (thermal-structural) simulation laying the basis to predict warpage and residual stresses in an over-extruded product with complex cross-section using UD-GF/PET commingled yarns over-extruded with rigid PVC. It makes use of experimentally determined temperature-dependent mechanical properties as well as temperature-dependent thermal properties (specific heat capacity, thermal conductivity). The finite element model is compared to experimental data in order to check the validity. The thermal simulation has a maximum deviation of less than 15% when compared to experimentally determined temperatures. A strong overestimation is observed regarding the warpage prediction when compared to experimental data, which has been attributed to the simulated bonding conditions between the components. [ABSTRACT FROM AUTHOR]

All-cellulose composite (ACC) is a novel single component bio-based material that consists of cellulose for both fiber and matrix phases. ACC has good mechanical, thermal and optical properties due to the compatibility of fiber and matrix phases. However, abundant hydroxyl groups in the cellulose molecules make ACC hydrophilic thus limiting the potential outdoor applications of ACC. In this present study, the ACC was fabricated by using solvent infusion processing (SIP) from rayon textile. The NaOH/urea was used as the solvent to partially dissolve the cellulose. Then, ACC was treated with hexadecyltrimethoxysilane (HDTMS) to produce hydrophobic ACC. The FTIR spectra of HDTMS treated ACC showed the new peak appears at 2850 cm−1, 1103 cm−1, and 793 cm−1 that attributed to -CH2 stretching, asymmetric stretching of Si-O-Si band and Si-OH stretching vibrations, respectively. The surface morphology of HDTMS treated ACC was rougher compared to untreated ACC. Furthermore, the HDTMS treated ACC exhibited significant hydrophobicity with a high water contact angle that can go up to 145.1°. [ABSTRACT FROM AUTHOR]

The present study uses density functional theory (DFT) and non-equilibrium Green's function (NEGF) to investigate the transmission coefficient T (E) for dithino-naphtridine molecules with different positions of side group oxygen atoms. The electric conductance calculation shows that the bare molecule has a higher conductance than the molecules with oxygen dangling, which varied from-4.7 to-5.5(eV), while the Seebeck coefficient (S) is found for all molecules with a positive sign with a higher value of 254 (µV/K) for molecules terminated by hydrogen around Fermi level EF = 0. Other thermal parameters are calculated, such as thermal conductance K which is found to change between 55 x10−15 for M_1and 4x10−15 (w/K.m) for M_3. Finally, the higher value of the figure of merit (ZT) is about 0.8 for molecule M_3. [ABSTRACT FROM AUTHOR]

The household sector consumes the largest amount of energy compared to other sectors in Indonesia. The most consuming instrument is the air conditioning (AC) system, as the tropical climate of Indonesia yields outdoor temperature that is higher than the standardized temperature for thermal comfort. Phase change material (PCM) possesses the potential to reduce the employment of energy for the AC system by reducing the total envelope heat transfer rate incorporated into a building through the walls. However, the selection of PCM and its integration configuration with the building materials are subjected to the climate environment. This study examined the thermal performance of some PCMs that are integrated with lightweight concrete through numerical simulation using EnergyPlus software. The integration of lightweight concrete with a PCM titled RT 35 manufactured by Rubitherm Technologies GmbH company yields the highest envelope heat gain transfer rate reduction. Meanwhile, the middle-layer placement of the PCM performs better than the configurations that placed the PCM on the wall's outer and inner surface. This is due to the PCM being imposed on a smaller temperature difference with its surroundings. Analysis of the thermal properties of the 20 mm thick PCM RT 35 placed on the middle layer of the walls yields the thermal resistance value of 0.141 m2-K/W. [ABSTRACT FROM AUTHOR]

This article presents the results of the thermal properties of modified cellulose-containing materials with oligomeric flame retardants synthesized on the basis of 3-chloro-1,2-hydroxypropane with 2,4,6-triamino-1,3,5-triazine. The dependences of the mass loss of cellulose materials modified with a fire retardant, the rate of mass loss, temperature, and the dynamics of the release of combustible gases from time to time were studied. [ABSTRACT FROM AUTHOR]

In recent years, materials of nanometric size have become the object of interest of scientists, due to the possibilities of using them in various industries, including the paint and varnish industry. Companies are looking for new solutions and patents to make coatings mainly environmentally friendly as well as harmless to people. Very often, scientists use nano-metals or their oxides, because they are characterized by different properties at the nano-scale. The aim of the study was to obtain silver nanoparticles by reducing silver nitrate and their addition to the paint composition. The stability and size of particles of dispersion systems containing nano-silver have been examined. It was found that the nano-silver content in the amount of 2% (w/w) exerts a positive influence on the stability. More detailed analysis has shown that the dispersion system under consideration undergoes the normal distribution. More amount of nano-silver makes the particles smaller. The studies of the thermal properties of the layers obtained from the paint composition showed that the increase in the nano-silver content in the system shifts the range of the film temperature towards higher values. Consequently, the layer becomes harder and less flexible. Derywatography analysis has indicated that the maximal temperatures of the exothermic effect−after addition of nano-silver particles−lead to higher temperature values in the systems. It was shown that the addition of nano-silver into the varnish composition has a beneficial effect both on its stability (backscattering, turbiscan stability index) and the properties of the layers formed. [ABSTRACT FROM AUTHOR]

A composite hydrogel beads bio-sorbent was introduced through this work by cross-linking cellulose, chitosan, magnetite, and alginate (CCMA) for removal of heavy metal copper. The effect of CCMA's dosage and contact time in adsorbate solution was also studied through this work to determine the highest percentage of copper metal, Cu (II) removal. Based on the effect of CCMA dosage and adsorption contact time in copper solution studied, an excellent percentage of Cu (II) removal of 97.47% was achieved at 4g of CCMA dosage and 24-hour contact time to reach its adsorption equilibrium state. Moreover, the thermal properties and stability of CCMA investigated through TGA analysis in this work revealed that the thermal stability of CCMA was significantly improved with a high mass residual of 92.35% compared to cellulose and chitosan powder. Thus, it is proven that the cross-linking of cellulose-chitosan-magnetite-alginate (CCMA) in this work was successfully done. [ABSTRACT FROM AUTHOR]

This study investigates the influence of microstructure and its related performances on the thermal and mechanical behaviors of porous concrete impregnated with phase-change material (PCM), referred to as PoroPCM. The material is composed of microencapsulated PCM particles embedded in a composite of aqueous foam and cement paste binder. Cement paste and 20% volume replacement of paraffin-based melamine-formaldehyde-coated PCM were used to prepare the paste, which was mixed with 20%, 40%, and 60% volume substitution of foam to prepare specimens. Two mixing methods were applied, one involving gentle mixing and other utilizing a high energy mixer. X-ray computed tomography (CT) was used to visualize the 3D microstructures of the specimens, and the datasets obtained from X-ray CT scans showed that micropore structures differed according to the mixing method. Thermal behavior was measured by inserting thermocouples at the center of cube specimens and increasing their temperature in a controlled environment chamber. Results of temperature rise at the center of cube specimens showed significant temperature control performance (temperature rise delay) with the phase transition of PCM. While compressive strength results revealed that it depended mainly on the porosity of the specimens, the specimens failed with large ductile deformations and cracks failed to propagate owing to the disaggregation of local collapse of the pore walls. [ABSTRACT FROM AUTHOR]