Evaluation of Light Distribution and the Penetration Depth under Isometric Studies using fNIRS

Functional near-infrared spectroscopy (fNIRS) has been widely used to solve the propagation of light inside the tissues and to quantify the oxygenation level of hemoglobin and myoglobin in human muscle. Penetration depth is one of the highlighted optical properties in this instrument in order to make sure light can be penetrated into deep human tissue layers. In this paper, our ultimate aim is to measure the penetration depth of muscle under different oxygenation states of isometric assessment in human using fNIRS. 27 sedentary healthy volunteers participated in this study. The result showed that, after all assessments, the mean signal of 3.0 and 4.0 cm distance of penetration depth showed more significant value detection (p≤0.05) measured by fNIRS. In addition, deoxygenated (p=0.031) show more significant in gender analysis compare to the oxygenated and total of hemoglobin and myoglobin. Thus, this result may help us to prove that our human muscle is transparent to this near infrared region and might be a useful tool for detecting oxygen status in muscle from living people either athletes or working people

Experimental study on mechanical properties of elastomer containing carbon nanotubes

Recently, elastomer reinforced with nanofillers have attracted great interest due to their properties. The incorporation of carbon nanotubes into elastomers improves significantly their mechanical and dynamic mechanical properties. Carbon nanotubes (CNTs) were used to prepare natural rubber (NR) nanocomposites. Four different NR compounds containing CNTs were investigated. Compounds were prepared by a two roll mill with conventional and efficient cure systems. The properties of the nanocomposites such as tensile strength, tensile modulus and elongation at break were studied. Results obtained show that a smaller amount of CNTs can effectively improve the performance of NR. NR with 1% CNTs composites exhibited better tensile strength compared to other compounds. The study also indicated that filler materials effect on the mechanical properties of the blends

Fabrication Of A-C:B/N-Si Solar Cells With Low Positive Bias By Custom-Made-CVD

Abstract: Boron doped amorphous carbon (a-C:B) film fabricated on n-type silicon using waste palm oil precursor by low positive bias voltage is presented. The rectifying curve were found for all samples under dark measurement revealed that those samples were p-type semiconductor. The +30 V was found the optimized of the electronic properties with the open circuit voltage (VOC), current density (JSC), fill factor (FF) and efficiency (%) were approximately 0.259034 V, 1.299456 mA/cm 2 , 0.240011, and 0.080788 %, respectively. The conversion efficiency of a-C:B has been improved under the influenced of low positive bias

ZnO Nanoparticles on Si, Si/Au, and Si/Au/ZnO Substrates by Mist-Atomisation

ZnO nanoparticles were prepared on Si substrates by a mist-atomisation technique. Precursor of aqueous solution zinc nitrate and HMTA were released on substrates heated at 200, 300, and 400°C confined in chamber box. The surface of Si substrate was varied, that is, gold-seeded Si (Si/Au), ZnO nanorods on Si/Au (Si/Au/ZnO), and just Si. The samples were subsequently analysed by X-ray diffraction, scanning electron microscopy, and photoluminescence (PL) spectroscopy to study their structural, surface morphology, and PL emission properties. Analysis from the XRD patterns of the films showed strong a- and c-axis lattice and of pure ZnO hexagonal wurtzite type. The crystallite size varied from 6 to 43 nm and was found to generally increase with increasing substrates' temperatures (Ts). SEM micrographs revealed granular-like structure throughout. Shifts pattern of PL emission at ultraviolet and visible range was found to support size changes observed. Both substrate surface type and deposition temperature were found to significantly affect crystalline growth of ZnO nanoparticles. Chemical equations and justification for growth patterns are also suggested

Fabrication, structural, optical, electrical, and humidity sensing characteristics of hierarchical NiO nanosheet/nanoball fower like structure flms

In this work, nickel oxide (NiO) nanosheet/nanoball-fower-like structures (NSBS) were directly grown on a NiO seed-coated glass substrate using a low-temperature immersion method at 75 ºC. The thickness, or density, of the nanoball-fower-like structures difered based on the following samples order: NSBS1< NSBS2< NSBS3. The synthesised NSBS flms were investigated in terms of structural, optical, electrical, and humidity sensing characteristics. The X-ray difraction (XRD) analysis revealed that the NSBS samples corresponded to the face-centred cubic NiO with fve difraction patterns indexed to the (111), (200), (220), (311), and (222) planes. The interplanar spacing, lattice parameter, unit cell volume, strain, and stress were also determined from the XRD results. The transmittance spectra showed that the NSBS samples had a transparency of more than 30% in the visible region. The optical bandgap values for the NSBS samples were estimated in the range between 3.72 and 3.75 eV, which is directly related to their lattice expansion and defect characteristics. The current–voltage and Hall efect measurement results revealed that the NSBS2 displayed good electrical properties with the resistance, hole concentration, and hole mobility values of 7.84 MΩ, 8.71×1015 hole/cm−3, and 1.88×102 cm2 /V s, respectively. The NSBS samples performed well for humidity sensing with the highest sensitivity value of 169 being obtained for the NSBS2. These humidity sensing results correlated well with their structural, optical, and electrical characteristics

Effect of substrate placement in schott vial to hematite properties

In the present study, hematite (α-Fe2O3) nanostructures were deposited on fluorine doped tin oxide (FTO) coated glass substrate using sonicated immersion synthesis method. The effect of FTO glass substrate placement in Schott vial during immersion process was studied on the growth of the hematite nanostructure and its properties. XRD pattern has revealed seven diffraction peaks of α-Fe2O3 for both hematite nanostructures samples attributed to polycrystalline with rhombohedral lattice structure. The surface morphologies from FESEM have shown that the hematite nanostructures were grown uniformly in both samples with FTO conductive layer facing up and down. Hematite sample with FTO facing down exhibits a smaller size of nanorod, 26.7 nm average diameter, compared to the hematite sample that FTO face up with 53.8nm average diameter. Optical properties revealed higher transmittance in the sample with FTO facing down, probably due to smaller size of nanostructure. The optical band gap energy plotted and extrapolated at 2.50eV and 2.55eV for FTO face up and FTO face down hematite samples respectively, presenting the sample with FTO face up has a lower optical bandgap energy

Mechanical and Morphological Properties of Tropical Wood Polymer Nanocomposite (WPNC)

A novel route to wood modification by impregnation of nanoclay combined with phenol formaldehyde (PF) resin is developed in this study. Wood polymer nanocomposites (WPNCs) were prepared from several tropical wood species by impregnating the woods with PF/nanoclay formulations. The vacuum-pressure method was used to impregnate the samples with PF/nanoclay prepolymer mixture. The formation of wood polymer nanocomposites and the location of impregnated materials inside wood were confirmed through SEM image and XRD pattern respectively. The PF/nanoclay loading achievable was found to be dependent on the properties of wood species. Low loading was observed for the high density wood species. Mechanical strength of fabricated WPNCs in terms of modulus of elasticity (MOE) was found to be significantly improved. Furthermore, morphological properties of raw wood and WPNC samples were evaluated by scanning electron microscopy (SEM) and XRD analysis and a change in morphological properties was also observed for WPNC

EXPERIMENTAL STUDY ON MECHANICAL PROPERTIES OF ELASTOMER CONTAINING CARBON NANOTUBES

Recently, elastomer reinforced with nanofillers have attracted great interest due to their properties. The incorporation of carbon nanotubes into elastomers improves significantly their mechanical and dynamic mechanical properties. Carbon nanotubes (CNTs) were used to prepare natural rubber (NR) nanocomposites. Four different NR compounds containing CNTs were investigated. Compounds were prepared by a two roll mill with conventional and efficient cure systems. The properties of the nanocomposites such as tensile strength, tensile modulus and elongation at break were studied. Results obtained show that a smaller amount of CNTs can effectively improve the performance of NR. NR with 1% CNTs composites exhibited better tensile strength compared to other compounds. The study also indicated that filler materials effect on the mechanical properties of the blends

Electrical and Structural Properties of PVDF/Mgo (7%) Nanocomposites Thin Films at Various Annealing Temperatures

Abstract—Poly (vinylideneflouride)/nano-magnesium oxide (PVDF/MgO) film with 7% MgO loading percentage was annealed at various annealing temperatures ranging from 70°C to 150°C. The PVDF/MgO thin film was fabricated using spin coating technique with a metal-insulator-metal (MIM) configuration. The dielectric and electric properties of PVDF/MgO with respect to annealing temperatures was studied. The PVDF/MgO nanocomposites thin films annealed at temperature of 70°C (AN70-PVDF/MgO) showed an improvement in the properties; dielectric constant value of 26 at 1 kHz frequency compared to un-annealed sample (UN-PVDF/MgO), which is 21 at the same frequency. As the annealing temperatures were increased from 90°C (AN90) to 150°C (AN150-PVDF/MgO), the dielectric constant values were found to gradually decreased from 25 to 12 respectively, which was lower than the UN-PVDF/MgO thin films. AN70-PVDF/MgO also produced relatively low tangent loss (tan δ). The resistivity value of AN70-PVDF/MgO was also found to increase from 3.08x104 Ω.cm (UN- PVDF/MgO) to 4.55x104 Ω.cm. The increased in the dielectric constant, with low tangent loss and high resistivity value suggests that 70°C was the favorable annealing temperature for PVDF/MgO film suitable for the application in electronic devices such as low frequency capacitor

Annealing Heat Treatment of ZnO Nanoparticles Grown on Porous Si Substrate Using Spin-Coating Method

ZnO nanoparticles were successfully deposited on porous silicon (PSi) substrate using spin-coating method. In order to prepare PSi, electrochemical etching was employed to modify the Si surface. Zinc acetate dihydrate was used as a starting material in ZnO sol-gel solution preparation. The postannealing treatments were investigated on morphologies and photoluminescence (PL) properties of the ZnO thin films. Field emission scanning electron microscopy (FESEM) results indicate that the thin films composed by ZnO nanoparticles were distributed uniformly on PSi. The average sizes of ZnO nanoparticle increase with increasing annealing temperature. Atomic force microscopic (AFM) analysis reveals that ZnO thin films annealed at 500°C had the smoothest surface. PL spectra show two peaks that completely correspond to nanostructured ZnO and PSi. These findings indicate that the ZnO nanostructures grown on PSi are promising for application as light emitting devices