This work intends to develop an effective heavy metal-free modifier having properties comparable to traditional stabilizers and flame retardants, simultaneously being environmentally friendly and may be superior in many aspects. The important requirement focused on is: how to increase thermal stability and flame retardancy of flexible poly(vinyl chloride). Due to the typical materials now used with poly(vinyl chloride), which increases health and environmental concerns, utilizing a novel heavy metal-free additive will make poly(vinyl chloride) substantially safer. We have used an artificial silicate for this aim, which proved to be an efficient flame retardant and surprisingly showed excellent heat stabilizing effect. Thermal stability of flexible poly(vinyl chloride) was tested by both discoloration and hydrochloric-acid release methods. Fire properties were tested by limiting oxygen index (L.O.I) method. And penetration resistance of poly(vinyl chloride) has been tested by vicat test. The improvement rate in the thermal stability time during the dehydrochlorination test was 110.7% at 160°C and 90.1% at 180°C. Also, the improvement rate in the L.O.I test was 22.2%, which increased from 21.6% for the poly(vinyl chloride) to 26.4% when 5wt.% of artificial silicate was added. The artificial silicate also increases the thermal stability of the poly(vinyl chloride) and maintains its appearance of more saturated chromatic saturated (brighter). In addition, artificial silicate increases the resistance to hot penetration of poly(vinyl chloride). Where the resistance of poly(vinyl chloride) increased by 8.9% after adding 5wt.% of artificial silicate.
This study investigated the bioethanol production from green algae Chlorella vulgaris depending on its carbohydrate-enriched biomass. Four different phosphorous concentrations were employed to stimulate bioethanol production from Chlorella vulgaris. The impact of various phosphorous values on Chlorella vulgaris growth rate as well as primary product (carbohydrate) were evaluated. High performance liquid chromatography was utilized in this work. The stationary phase was identified as day 14, 12, 10 and 6 in treatments 6, 4, 2 and g/L, respectively. The findings suggest that the treatment without phosphorous addition had the highest record of carbohydrate content (22.64% dry weight) as well as the highest bioethanol yield (20.66% dry weight).
... Show MoreThe spectroscopic properties, potential energy curve, dipole moments, total charge density, Electrostatic potential as well as the thermodynamic properties of selenium diatomic halides have been studied using code Mopac.7.21 and hyperchem, semi-empirical molecular orbital of MNDO-method (modified neglected of differential overlap) of parameterization PM3 involving quantum mechanical semi-empirical Hamiltonian. The relevant molecular parameters like interatomic distance, bond angle, dihedral angle and net charge were also calculated.
This study proposes a new method for designing adaptive routing algorithms for three‐dimensional (3D) networks‐on‐chip (NoCs). This method is based on extending the existing 2D turn model adaptive routing to a 3D scenario. A 3D plane‐balanced approach with maximal degree of adaptiveness is achieved by applying a well‐defined set of rules for different strata of the 3D NoC. The proposed method is applicable to any of the turn models. In this study, the authors employ odd–even turn model as a basis for introducing the proposed strategy. Experimental results show that the new 3D odd–even turn model can achieve up to 28.5% improvement in performance over conventional 3D odd–even approach. The improvement is consistent fo
... Show MoreIn this work, the spectra for plasma glow produced by pulse
Nd:YAG laser (λ=532 and 1064nm) on Ag:Al alloy with same molar
ratio samples in distilled water were analyzed by studying the atomic
lines compared with aluminum and silver strong standard lines. The
effect of laser energies of the range 300 to 800 mJ on spectral lines,
produced by laser ablation, were investigated using optical
spectroscopy. The electron temperature was found to be increased
from 1.698 to 1.899 eV, while the electron density decreased from
2.247×1015 to 5.08×1014 cm-3 with increasing laser energy from 300
to 800 mJ with wavelength of 1064 nm. The values of electron
temperature using second harmonic frequency are greater than of<
Thin films of highly pure (99.999%) Tellurium was prepared by high vacuum technique (5*10-5torr), on glass substrates .Thin films have thickness 0.6m was evaporated by thermal evaporation technique. The film deposited was annealed for one hour in vacuum of (5*10-4torr) at 373 and 423 K. Structural and electrical properties of the films are studies. The x-ray diffraction of the film represents a poly-crystalline nature in room temperature and annealed film but all films having different grain sizes. The d.c. electrical properties have been studied at low and at relatively high temperatures and show that the conductivity decreases with increasing temperature at all range of temperature. Two types of conduction mechanisms were found to d
... Show MoreThin a-:H films were grown successfully by fabrication of designated ingot followed by evaporation onto glass slides. A range of growth conditions, Ge contents, dopant concentration (Al and As), and substrate temperature, were employed. Stoichiometry of the thin films composition was confirmed using standard surface techniques. The structure of all films was amorphous. Film composition and deposition parameters were investigated for their bearing on film electrical and optical properties. More than one transport mechanism is indicated. It was observed that increasing substrate temperature, Ge contents, and dopant concentration lead to a decrease in the optical energy gap of those films. The role of the deposition conditions on value
... Show MoreObjective: In this work we design and evaluate a bidirectional pneumatic soft actuator made from silicone rubber (RTV2 C10) for the use in prosthetic hand. The actuator aimed to enhance flexibility and provide motion in two directions that mimic the actions of the human fingers. Materials and Methods: Two parallel air chambers are used in the actuator design where each chamber is divided into smaller internal cavities. These chambers are linked through a narrow connecting channel. The fabrication process relied on a molding technique based on 3D printed molds. Three separate mold components were designed and printed to allow accurate casting of silicone rubber into the desired shape. The completed actuators were then tested using an experim
... Show More