Subjects -> CHEMISTRY (Total: 986 journals)
    - ANALYTICAL CHEMISTRY (59 journals)
    - CHEMISTRY (713 journals)
    - CRYSTALLOGRAPHY (23 journals)
    - ELECTROCHEMISTRY (28 journals)
    - INORGANIC CHEMISTRY (45 journals)
    - ORGANIC CHEMISTRY (47 journals)
    - PHYSICAL CHEMISTRY (71 journals)

ANALYTICAL CHEMISTRY (59 journals)

Showing 1 - 46 of 46 Journals sorted alphabetically
Accounts of Chemical Research     Hybrid Journal   (Followers: 63)
Acta Analytica     Hybrid Journal   (Followers: 6)
Advances in Analytical Chemistry     Open Access   (Followers: 29)
American Journal of Analytical Chemistry     Open Access   (Followers: 31)
Analitika i kontrol` (Analytics and control)     Open Access  
Analytica Chimica Acta     Hybrid Journal   (Followers: 43)
Analytica Chimica Acta : X     Open Access  
Analytical and Bioanalytical Chemistry     Hybrid Journal   (Followers: 27)
Analytical and Bioanalytical Chemistry Research     Open Access   (Followers: 2)
Analytical Chemistry     Hybrid Journal   (Followers: 237)
Analytical Chemistry Insights     Open Access   (Followers: 21)
Analytical Chemistry Letters     Hybrid Journal   (Followers: 2)
Analytical Letters     Hybrid Journal   (Followers: 9)
Annual Review of Analytical Chemistry     Full-text available via subscription   (Followers: 12)
Chemical Data Collections     Hybrid Journal  
Chinese Journal of Analytical Chemistry     Full-text available via subscription   (Followers: 5)
Composites Communications     Full-text available via subscription   (Followers: 2)
Comprehensive Analytical Chemistry     Full-text available via subscription   (Followers: 7)
Critical Reviews in Analytical Chemistry     Hybrid Journal   (Followers: 27)
Current Analytical Chemistry     Hybrid Journal   (Followers: 10)
Drug Testing and Analysis     Hybrid Journal   (Followers: 10)
Electroanalysis     Hybrid Journal   (Followers: 6)
Field Analytical Chemistry and Technology     Hybrid Journal   (Followers: 6)
International Journal of Analytical Chemistry     Open Access   (Followers: 21)
International Journal of Environmental Analytical Chemistry     Hybrid Journal   (Followers: 7)
International Journal of Polymer Analysis and Characterization     Hybrid Journal   (Followers: 8)
Journal of Analysis and Testing     Hybrid Journal  
Journal of Analytical Atomic Spectrometry     Hybrid Journal   (Followers: 8)
Journal of Analytical Chemistry     Hybrid Journal   (Followers: 21)
Journal of Electroanalytical Chemistry     Hybrid Journal   (Followers: 7)
Journal of Essential Oil Research     Hybrid Journal   (Followers: 3)
Journal of Progressive Research in Chemistry     Open Access  
Journal of Radioanalytical and Nuclear Chemistry     Hybrid Journal   (Followers: 7)
Journal of Thermal Analysis and Calorimetry     Hybrid Journal   (Followers: 24)
Microchemical Journal     Hybrid Journal   (Followers: 4)
Nature Catalysis     Hybrid Journal   (Followers: 6)
Nigerian Journal of Chemical Research     Full-text available via subscription   (Followers: 1)
Opflow     Full-text available via subscription   (Followers: 1)
Pharmaceutical Analytical Chemistry: Open Access     Open Access   (Followers: 1)
Phytochemical Analysis     Hybrid Journal   (Followers: 3)
Polish Journal of Chemical Technology     Open Access   (Followers: 1)
Surface and Interface Analysis     Hybrid Journal   (Followers: 15)
TrAC Trends in Analytical Chemistry     Full-text available via subscription   (Followers: 46)
Trends in Environmental Analytical Chemistry     Hybrid Journal   (Followers: 3)
Vibrational Spectroscopy     Hybrid Journal   (Followers: 11)
World Journal of Analytical Chemistry     Open Access   (Followers: 3)
Similar Journals
Journal Cover
Journal of Thermal Analysis and Calorimetry
Journal Prestige (SJR): 0.587
Citation Impact (citeScore): 2
Number of Followers: 24  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 1388-6150 - ISSN (Online) 1588-2926
Published by Springer-Verlag Homepage  [2537 journals]
  • Effects of on MnO2 nanoparticles behavior of a sardine oil methyl ester
           operated in thermal barrier coated engine

    • Free pre-print version: Loading...

      Abstract: In the present study, an experimental investigation has been carried out with a single-cylinder four-stroke conventional engine using sardine oil methyl ester (SOME) and diesel with MnO2 nanoparticle at different load conditions. MnO2 nanoparticles of 25 ppm concentration were mixed with SOME and diesel with the aid of ultrasonication. Because of its long life and low heat conductivity, partly stabilized zirconium with a thickness of 0.5 mm is used as the coating material. Plasma spraying was used to coat the piston top face, as well as the inlet and outflow valves. MnO2 has a lot of promise, as well as good physical and chemical qualities, and it reduces emissions in diesel engines. The outcome of results showed that the performance was improved while using nanoadditive along with SOME. Break Thermal Efficiency, rate of heat release, and in-cylinder pressure of SOME with 25 ppm of MnO2 were increased by 7.5%, 9.2%, and 7.2%, respectively, as correlated with diesel, due to the oxygen particle available in the fuel and improved combustion process. The nitrogen oxides, hydrocarbon, and CO of SOME with 25 ppm of MnO2 were decreased by 11.5%, 42.5%, and 7.4%, respectively, as compared to the baseline fuel, because of low ignition delay and proper atomization during combustion. Hence, it is concluded that 25 ppm of MnO2 with SOME has improved the performance and significantly reduced the emission.
      PubDate: 2022-01-13
       
  • Thermal analysis assisted by spectra-structure studies of BCS class II
           active pharmaceutical ingredients: ezetimibe and lercanidipine
           hydrochloride. The concept of preformulation

    • Free pre-print version: Loading...

      Abstract: A detailed thermal analysis investigation of title BCS class II active pharmaceutical ingredients with low solubility and high permeability and known polymorphism were reported. Differential scanning calorimetry (DSC) and thermogravimetry analysis (TG) were used as primary screening techniques to assess into the polymorphic stability of the studied APIs relative to their thermal properties. The solid-state behavior of the drug compounds was further evaluated by X-ray powder diffraction (XRPD) and Fourier transform infrared spectroscopy (FT-IR). The spectra-structural techniques were applied as supportive tools to confirm and correlate the DSC and TG results obtained by preformulation testing. As an attempt to broaden the thermal analysis, a temperature-modulated DSC (TMDSC) was developed to examine the physical properties and explain the polymorphic stability of the studied amorphous lercanidipine HCl. The TMDSC results also aimed to determine the thermal properties comprising glass transition temperature (Tg) and heat capacity (ΔCp). Based on the thermal evolution and the applied preformulation tests, both drug substances manifested considerable increase in their moisture content (hygroscopicity) in relatively short time after exposure on elevated relative humidity in stability testing chambers. The results obtained from the above-mentioned instrumentation inevitably confirmed occurrence of polymorphic transition for both active substances after recrystallization from absolute ethanol. To the best of our knowledge, the study reports new type of crystalline form of lercanidipine HCl as well as unveils the transition of anhydrous ezetimibe to monohydrate form. In addition, the thermal behavior of amorphous lercanidipine HCl is, for the first time, outlined and described in this work.
      PubDate: 2022-01-13
       
  • Slip impact on double-diffusion convection of magneto-fourth-grade
           nanofluids with peristaltic propulsion through inclined asymmetric channel
           

    • Free pre-print version: Loading...

      Abstract: The significance of double-diffusivity convection and an inclined magnetic field on peristaltic propulsion of fourth-grade nanofluids through an inclined asymmetric channel is the focus of this study. A mathematical model of a fourth-grade nanofluid is presented, by considering a tilted magnetic field and double-diffusivity convection. The highly nonlinear partial differential equations (PDE's) are simplified with the lubrication methodology. Numerical technique is used to solve the coupled and highly nonlinear PDE's. To examine the impact of varying physical characteristics like Brownian motion, thermophoresis, Hartmann number, nanoparticle Grashof number, slip parameters and trapping on flow quantities, numerical and graphical results are provided. It is acquired that when Brownian motion is increased, the pressure gradient drops; however, when the thermophoresis parameter is increased, the pressure gradient boosts. It is also notable that the profile of velocity resembles a parabolic form and maximum velocity retain at channel’s center.
      PubDate: 2022-01-13
       
  • Effects of partially stabilized zirconia fueled with Borassus biofuel at
           different piston bowl geometries in LHR engine

    • Free pre-print version: Loading...

      Abstract: The current computational fluid dynamics (CFD) speculate reveals piston bowl geometry’s impact on an immediate base engine execution and discharge. Different bowl shapes, that is, shallow combustion chamber, hemispheric combustion chamber, and toroidal combustion chamber (TCC), were made with a reference compression ratio of 17.5:1. ANSYS V18.1 was used for numerical investigation, in tandem with the wise burning model. It was clearly identified that TCC cylinder bowl geometry delivered the proper air–fuel mixing blend inside the cylinder chamber, which prompts a homogeneous charge. Further, analytical experiments were completed to break down the TCC cylinder bowl geometry by shifting the profundity of the bowls. The case with 1.26 mm decline top to bottom of the bowl from the benchmark TCC and covered with zirconium coating gives better results. TCC produced a very powerful squish over a short period of time. TCC’s fraction of mass in carbon monoxide emissions is down to 0.03 at 25o crank angle after TDC while both hemispherical combustion chamber and shallow depth combustion chamber are measured at nearly 0.1. It was found that TCC gave a better performance compared with the other two designs at full load conditions while operating from medium to high engine speed. Overall, the low-speed application of the engine was suitable for SCC design, and TCC design was suitable for higher-speed application.
      PubDate: 2022-01-13
       
  • Thermal behaviours at low and high temperature of biodiesels produced from
           beef tallow and corn oil

    • Free pre-print version: Loading...

      Abstract: The thermal behaviours and kinetics of biodiesels produced from beef tallow and corn oils were examined by using thermal analysis techniques (TG-DTG/DSC) at different heating rates in this study. The biodiesels were analysed with 1H-NMR and GC–MS techniques. It was seen that the biodiesel samples are composed of both saturated (Myristic acid C14:0, palmitic acid C16:0, stearic acid C18:0,) and unsaturated (Palmitoleic acid C16:1, oleic acid C18:1, linoleic acid C18:2) FAMEs from GC–MS analysis. Kinetic parameters for the combustion process of biodiesels were determined by using the iso-conversional model-free methods, KAS and FWO methods. The activation energy of beef-tallow biodiesel from KAS method is 86.11 kJ mol−1, and from FWO method is 83.52 kJ mol−1. The activation energy of corn-oil biodiesel from KAS method is 79.12 kJ mol−1, and from FWO method is 90.07 kJ mol−1. It was figured out that the activation energies of the biodiesel samples have values close to each other, and controlling reaction mechanism for both biodiesel samples by using master-plot method are power law (P4). It was obtained CP (cloud point) and CFPP (cold filter plugging point) values from DSC analysis. CP values of biodiesel from beef tallow and corn oil are 16.1 °C and − 5.5 °C, respectively. CFPP values of biodiesel from beef tallow and corn oil are − 11.2 °C and − 6.7 °C, respectively. It was obtained from TG-DSC analysis that the origins of biodiesel samples on thermal behaviours are dominant at low temperatures (< 0 °C), yet the origins are not important at high temperature, and the combustion properties are the same as each other.
      PubDate: 2022-01-11
       
  • Corrosion behavior and crystal-microstructural analysis of non-equiatomic
           NiTi shape memory alloys

    • Free pre-print version: Loading...

      Abstract: NiTi shape memory alloys (Nitinol) are one of the most widely used families of smart materials that are used in smart systems and medical applications. The NiTi alloy with a composition of around 50 at. % Ni is very sensitive and just a small change in the components can make a big difference in the physical properties of the alloy. In this study, five non-equiatomic NiTi alloys with different compositions were fabricated with arc-melting in a controlled atmosphere. The crystal structure and morphology of the alloys were analyzed with x-ray diffraction (XRD) and scanning electron microscope (SEM), also the caloric properties of the alloys were investigated as a function of composition. Additionally, the samples were examined by the Tafel test to determine the corrosivity rate for one year in a simulated body fluid. The XRD and DSC results showed that only Ni44.56Ti55.44 at. % has martensite phase at room temperature, while the other alloys with higher Ni contents did not show martensitic phase transformation for the range of 230 K to more than 400 K. It was found that the alloys have corrosion rate around 10–4 mmpy which has comparably better than CuAlNi-based alloys. On the other hand, it was found that the corrosivity does not depend on the matrix phase of the NiTi alloy, but the composition ratio and other secondary phases play an important role.
      PubDate: 2022-01-11
       
  • A parametric study of spectral radiation of gas-fuel combustion media in
           1-D furnace cases for energy utilization

    • Free pre-print version: Loading...

      Abstract: This paper studies the spectral radiation characteristics of gas-fuel combustion media through numerical calculation from the perspective of radiative energy utilization. Based on accurate band model for gas radiation and the radiation transfer equation, one-dimensional cases representing flame temperature field are constructed to investigate the effects of different flame media parameters on the spectral radiative energy proportion and total radiative heat flux, including the temperature, total pressure, partial pressure, path-length, and molar ratio. The interactions between the parameters are also analyzed. The radiation energy quality is also properly analyzed based on the equivalent temperature theory. It is found that temperature is the dominant influencing factor. At an average temperature of 1600 K, the proportion of spectral radiation in the waveband of 0–3 μm accounts for 55%. Increases in the total pressure, partial pressure, and molar ratio enhance the total radiative energy and short-wavelength radiation proportion. The total pressure and partial pressure have similar effects, but the molar ratio has a less effect, especially under high-pressure conditions. The equivalent temperature method can be used to compare the quality of radiative energy more conveniently. Increasing temperature is the most important factor in improving energy quality. This study provides a reference for spectral radiative energy management and future research on photo and thermal energy cascade utilization based on fuel combustion.
      PubDate: 2022-01-11
       
  • Experimental evaluation of the thermal performance and capillary limit of
           a screen mesh heat pipe using SDBS and Al2O3-water-based nanofluids

    • Free pre-print version: Loading...

      Abstract: This study evaluates the effect of using alumina (Al2O3)-water nanofluids stabilized by sodium dodecylbenzene sulfonate (SDBS) on the thermal performance and capillary limit of a screen mesh heat pipe. Nanofluids were prepared using three Al2O3 concentrations (0.1 mass/%, 0.5 mass/%, and 1.0 mass/%) and two SDBS concentrations (0.064 mass/% and 0.32 mass/%). The stability of the nanofluids was studied by means of UV-absorbance measurements prior to the experimental test. The results show that the thermal resistance of the heat pipe decreased by up to 50% with Al2O3 and SDBS at concentrations of 0.5 mass/% and 0.32 mass/%, respectively. Nevertheless, the capillary limit was reduced between 25 and 45 W compared to the operation with water. Finally, the capillary limit was improved by 5 W (compared to water) using an Al2O3 concentration of 0.1 mass/% and no surfactant.
      PubDate: 2022-01-11
       
  • Excess enthalpies of [CnMIM][NTf2] n = (2 or 10) + ethanol
           

    • Free pre-print version: Loading...

      Abstract: Mixtures containing 1-alkyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [CnMIM][NTf2] n = {2, 10}, + ethanol or + N-methyl-2-pyrrolidone have been investigated to determine excess molar enthalpies, HE, and excess partial molar enthalpies of components, \(H_{1}^{{\text{E}}}\) and \(H_{2}^{{\text{E}}}\) , over the entire mole fraction, x1, range, at 298.15 K and 0.10 MPa. Ionic liquids, ILs, were pre-treated by heating and by using activated molecular sieves. Both mixtures in ethanol are endothermic and the \(H_{{\text{i}}}^{{\text{E}}}\) of the components are always positive while those in NMP are exothermic and the corresponding values of \(H_{{\text{i}}}^{{\text{E}}}\) are negative, in the whole x1 range. The deviations from ideality are quite significant, being the HE values at equimolar composition, \(H_{{{\text{eq}}}}^{{\text{E}}} \pm u\) ; (+ 1800 ± 40 and + 2110 ± 10) J mol−1 for ethanol-containing mixtures and (− 1410 ± 10 and − 1980 ± 20) J mol−1 for NMP-containing mixtures ( \(u\) is the standard uncertainty). The values of the excess partial molar enthalpies at infinite dilution of the components, \(H_{\rm i}^{{{\text{E,}}\infty }}\) , show regular trends. The \(H_{1}^{{{\text{E,}}\infty }}\) are always greater than the \(H_{2}^{{{\text{E,}}\infty }}\) ; their ratio is about 1.8 for mixtures in EtOH and 2.5 for NMP-containing mixtures. The greatest thermal effects are found when the molecular compound acts as a solvent in the dissolution of one mole of IL, under extreme dilution condition.
      PubDate: 2022-01-11
       
  • Thermal performance of a radial heat sink with longitudinal wavy fins for
           electronic cooling applications under natural convection

    • Free pre-print version: Loading...

      Abstract: Heat dissipation by natural convection from heat generating electronic devices is a ubiquitous phenomenon in engineering and research to improve the thermal efficiency of the devices and upsurge their lifespan. In this context, this paper outlines a numerical study on the thermal performance of a radial heat sink with longitudinal wavy fins under the influence of pure natural convection. Three-dimensional numerical computations have been performed to elucidate the heat dissipation characteristics from a horizontally oriented radial heat sink with considering the following pertinent parameters: Rayleigh number (Ra), number of fins (Nfin), fin height (H/d), pitch-to-amplitude ratio (P/A) of the wavy fin, and number of cycles (n) in a wavy fin. A limiting case of straight longitudinal fins is also simulated to compare and justify the use of wavy fins over straight fins. At certain ranges of the pertinent parameters, wavy fins intensify the thermo-buoyant flow and augment the heat dissipation from the fin surface. The results reveal that wavy fins are superior to straight fins at higher Ra and below a critical Nfin, whereas straight fins are still superior at low Ra and higher values of Nfin. At higher Ra, the average Nusselt number (Nu) and fin effectiveness are higher for wavy fins of three cycles, followed by two and one cycles for Nfin below 24. Furthermore, the optimum Nfin for maximum fin effectiveness gradually increases with rise in Ra. The present study on longitudinal wavy fins affirms to be the very first research work in the field of radial heat sinks.
      PubDate: 2022-01-11
       
  • Thermal and economic performance evaluation of a novel sCO2 recompression
           

    • Free pre-print version: Loading...

      Abstract: A novel polygeneration system is designed to provide electricity, heating and cooling capacity on basis of solar energy. Two-stage power cycle of sCO2 Brayton and steam Rankine is propelled to generate electricity with residual heat transferred to drive an efficient heating device and an intercooled absorption cooling system. System performance is comprehensively analyzed from thermal efficiency in terms of energy and exergy, based on the quasi-steady numerical model. Results indicate that built system obtains electricity, heating and cooling capacity of 243.84, 42.05 and 10.746 MW with energy efficiency of 0.5304, 0.0915 and 0.0234 and exergy efficiency of 0.562, 0.0174 and 0.0024, respectively. Mass flows of working fluids and detailed specifications of solar collecting field are also included in this investigation. Parametric analysis exhibits that operating parameters exert remarkable influence on thermal efficiencies. Proposed system can save amounts of energy over three individual systems with identical products by means of a primary energy saving ratio analysis and energy saving performance is more sensitive to turbine inlet temperature of Brayton. Exergoeconomic evaluation reveals that designed system achieves inferior electricity performance and superior heating and cooling performance in comparison with current circumstance. In conclusion, this novel cogeneration system takes full advantage of solar energy to meet various energy consumptions.
      PubDate: 2022-01-11
       
  • What happens to the interfacial reaction between fluoropolymer and nano
           aluminum below 1000 ℃'

    • Free pre-print version: Loading...

      Abstract: The interfacial reaction of nano-aluminum (nAl) and fluoropolymer was evaluated using nAl@Viton composite under slow and rapid heating rates. The results under slow heating rates indicate that nAl@Viton composites reacted in several stages at 100–1000 °C. The oxide shell of nAl underwent a pre-ignition reaction with Viton before Viton decomposition, followed by the reaction of nAl with the products from Viton decomposition, and defluorination of aluminum fluoride. Temperature jump experiments were used to confirm the occurrence of interfacial reactions between nAl particles with the products produced by Viton decomposition, and the gaseous products of nAl@Viton during the reactions were investigated via online gas chromatography/mass spectrometry. Results show a direct correlation between the nAl particles and the relative abundance of products. The initial decomposition products of Viton would be induced to form more cyclic hydrocarbon by the fluorination of nAl with gaseous fluorocarbons and hydrogen fluoride released from Viton decomposition. Fluorination yields heat feedback to the reactive surface, thus providing the main advantage of aluminum–fluoropolymer reactive system for energy release.
      PubDate: 2022-01-11
       
  • A study on heat generation characteristics of Na3V2(PO4)3 cathode and hard
           carbon anode-based sodium-ion cells

    • Free pre-print version: Loading...

      Abstract: We report here the heat generation and impedance characteristics of prototype 18650-sized sodium-ion cells using pristine Na3V2(PO4)3 (P-NVP) and modified Na3.2V1.8Zn0.2(PO4)3 (M-NVP) cathodes, hard carbon (HC) anode and an ether-based non-flammable electrolyte, 1 M NaBF4 in tetraglyme. Comparison of calorimetric studies performed on 18650-sized cells reveals lower heat generation in M-NVP versus HC compared to P-NVP versus HC owing to low internal resistance achieved as a result of Zn2+ doping in M-NVP. Both irreversible heat generation arose due to internal resistance and reversible heat generation caused by entropic changes in the electrode materials are elucidated. Furthermore, variation in subcomponents of internal resistance in both 18650-sized full cells and CR2016-sized half-cells is analysed by fitting electrochemical impedance spectra into equivalent circuit models. Individual contributions of anode and cathode to the impedance characteristics of the cells are determined by analysing impedance data of the half-cells using the distribution of relaxation times method. The results reveal lower diffusion resistance, as well as charge transfer resistance in M-NVP cells compared to P-NVP counterpart, accounting for the observed lower total internal resistance in M-NVP versus HC and thus lower heat generation in M-NVP versus HC cell than P-NVP versus HC cell.
      PubDate: 2022-01-05
       
  • Ball-milled valsartan and its combination with mannitol: the case of drug
           polyamorphism

    • Free pre-print version: Loading...

      Abstract: Valsartan (VAL) is a drug that has low water solubility and low oral bioavailability. Unlike most drugs, bulk VAL has unusual solid-state properties, including the phenomenon of polyamorphism. Furthermore, surprisingly, obtaining the neat VAL in a completely amorphous form does not increase its solubility. In this study, the influence of different ball milling conditions (milling time and speed) on dissolution rate, thermoanalytical and solid-state properties of VAL was studied. The influence of the association of VAL with the hydrophilic carrier mannitol (as physical mixtures and solid dispersions, at different drug/carrier ratios) on drug dissolution, thermoanalytical and solid-state properties was also evaluated. Bulk VAL, milled-VAL and physical mixtures and solid dispersions (SDs) of the drug with mannitol were characterized by differential scanning calorimetry, powder X-ray diffraction analysis and Fourier transformed infrared spectroscopy. Ball milling the neat drug originated self-agglomerated particles, with lower dissolution rate than bulk VAL, and the conversion of VAL from a more ordered amorphous form to another fully amorphous and less soluble form. The same conversion occurred after ball milling of VAL with mannitol (SDs). This change in VAL polyamorphic forms resulting from the ball-milling process had not yet been described in other studies. The highest proportion of mannitol tested (VAL: mannitol 1:3 m/m) promoted a greater increase in the dissolution rate of the drug. A physical mixture prepared in the same composition showed a dissolution profile similar to these SDs. These results demonstrated that the simple association of VAL with mannitol is sufficient to improve its dissolution rate, without changing the solid state of drug.
      PubDate: 2022-01-05
       
  • Integration study among flying spot laser thermography and terahertz
           technique for the inspection of panel paintings

    • Free pre-print version: Loading...

      Abstract: Conservation of artworks is of paramount importance nowadays around the world. Clever conservation by using non-destructive testing techniques is highly appreciated by restorers and art historians. Among these, a special set-up working into the infrared region is the flying spot laser thermography technique that uses a punctual stimulus to transfer the heat from the source into the artwork. In this way, the precious surface is gently heated by avoiding any type of damage, such as color changes and/or shrinkage and warpage effects. To the best of our knowledge, the flying spot laser thermography technique, in the configuration proposed, has been used here for the first time in the cultural heritage field. It was applied in combination with terahertz inspection, an emergent technique in the field of art research, completely non-invasive and safe for the operator. The target to be inspected was a panel painting executed by following the rules dictated by the art master Cennino Cennini. Results demonstrated how such an integrated approach is plausible to provide robust information concerning invisible defects to the naked eye.
      PubDate: 2022-01-05
       
  • Valorization of not soluble byproducts deriving from green keratin
           extraction from poultry feathers as filler for biocomposites

    • Free pre-print version: Loading...

      Abstract: The valorization of poultry feathers wastes is very important to reduce the environmental pollution deriving from their disposal. In this frame, we present the production process of completely natural, biodegradable, biocompatible, and eco-friendly composites made by not soluble keratin (NSK) and poly(lactic acid) (PLA). NSK has been obtained as a byproduct of a microwave-assisted keratin extraction from poultry feathers and it has been added to PLA pellets without adding any additional compatibilizers or plasticizers, unlike from the other works reported in the literature until now. The mixture has been used to obtain homogeneous NSK-based PLA filaments by means of hot-melt extrusion technology. The filaments have been subsequently 3D printed to explore applications in the additive manufacturing field. All the samples have unaltered thermal stability, but reduced toughness with respect to neat PLA. Other tested parameters (water adsorption, glass transition, and crystallinity) are dependent on NSK content and fabrication technology. Besides, Fourier Transform Infrared Spectroscopy highlights the differences in the structure of the NSK-based PLA filaments and 3D printed samples.
      PubDate: 2022-01-04
       
  • Thermo-mechanical properties and electrical mapping of nanoscale domains
           of carbon-based structural resins

    • Free pre-print version: Loading...

      Abstract: Carbon nanostructured forms, such as one-dimensional (1D) carbon nanofibers (CNFs) and two-dimensional (2D) graphene nanoplatelets (GNPs), are increasingly attracting the attention of scientists whose studies are aimed at obtaining superior nanocomposites with unrivaled performance and/or unprecedented properties. In this work, nanocomposites loaded with different mass percentages of carbonaceous nanoparticles (CNFs, GNPs) capable to exhibit discrete electrical conductivity have been investigated using differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), and tunneling atomic force microscopy (TUNA). DSC and DMA investigations highlighted that an appropriate chemical composition of the hosting matrix, together with a suitable two-stage curing cycle allows formulating structural resins characterized by high values of the curing degree (higher than 97%), glass transition temperature (also higher than 250 °C), and storage modulus (higher than 3000 MPa at room temperature). TUNA analysis evidences a satisfactory distribution of the conductive nanofiller on nanometric domains.
      PubDate: 2022-01-04
       
  • Ferromagnetic Chaos in thermal convection of fluid through
           fractal–fractional differentiations

    • Free pre-print version: Loading...

      Abstract: Thermal convection suppresses the thermal stability and instability during the interaction between the magnetic fields because thermal convection is the most significant driver of time-dependent patterns of motion within magnetized and non-magnetized chaotic. In this manuscript, a mathematical modeling is proposed subject to the magnetohydrodynamic conductive fluid lying on an infinite horizontal layer subject to heat from below with gravity. The mathematical model is based on nonlinear ordinary differential equations and such model has been investigated by means of the Boussinesq approximation and Darcy's law. The newly defined techniques of fractal–fractional differential operators, namely Atangana–Baleanu and Caputo–Fabrizio fractal–fractional differentiations, have been imposed on the governing equations. The mathematical analysis based on the equilibrium points and stability criteria is investigated to examine the dynamic responses of a magnetized and non-magnetized conductive fluid model. The numerical simulations have been performed by Adams methods, which is so-called the explicit scheme of the Adams–Bashforth method. Our results suggest that the comparative evolution of trajectories between magnetized and non-magnetized chaotic behaviors has strong effects due to Lorentz force that showed the resistivity in chaotic phenomenon.
      PubDate: 2022-01-04
       
  • Correction to: Phase equilibria in the ErPO4-KPO3-Er(PO3)3 partial system

    • Free pre-print version: Loading...

      PubDate: 2022-01-01
       
  • Correction to: Investigation on the effect of cottonseed oil blended with
           different percentages of octanol and suspended MWCNT nanoparticles on
           diesel engine characteristics

    • Free pre-print version: Loading...

      Abstract: In the original publication of the article, the affiliations of the third, fourth and fifth authors were incorrectly published.
      PubDate: 2022-01-01
       
 
JournalTOCs
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Email: journaltocs@hw.ac.uk
Tel: +00 44 (0)131 4513762
 


Your IP address: 54.175.165.101
 
Home (Search)
API
About JournalTOCs
News (blog, publications)
JournalTOCs on Twitter   JournalTOCs on Facebook

JournalTOCs © 2009-