Materials Science articles list

Liquid isoprene rubber as a safe processing aid in natural rubber compounds

In order to overcome the carcinogenic ‘polycyclic aromatic hydrocarbon’ emission from aromatic oils, which are restricted in European countries since 2010, various efforts have been made to replace the aromatic oil in rubber-based compounds either fully or partially. The authors in the present work have used liquid isoprene rubber (LIR50 or LIR) as a reactive plasticizer in natural rubber (NR) compound at different loadings (2, 4, 6 and 8 phr) and have studied its effect on viscosity, curing characteristics and physico-mechanical properties. These results were compared with the control compound containing conventional aromatic oil as plasticizer. From the experimental data, it was noticed that, the minimum torque for control compound was 0.33 dNm and that for LIR based compounds ranged between 0.16 to 0.56 dNm. The LIR based compounds exhibited slightly higher Mooney viscosity but offers the same scorch safety. The study supports the utility of LIR as a promising alternative, as revealed by the comparable rheological and physico-mechanical properties attained with the usage of appropriate quantity of LIR, unlike the other alternatives of the previous investigations that usually showed a property difference. Keywords: aromatic oil, liquid rubber, reactive plasticizer, safe processing oil.

Chandresh M. P.

Surface modification of anhydrous borax with stearic acid by wet coating method

The wet coating of anhydrous borax powders with stearic acid (SA) to reverse their inherent hydrophilic surface properties was investigated. The coating procedure was based on the results from a previous study that revealed that the stearic acid solution (2 wt. % SA) mixed for 60 minute at 750 rpm on the magnetic stirrer was sufficient for the surface modification of anhydrous borax. For the experiments, stearic acid powders were first dissolved in water at 80 °C. The mixture obtained by adding anhydrous borax powders to this solution was vigorously mixed on a magnetic stirrer to initiation and completion the surface modification. Each of these solutions was then filtered using a filter paper to separate the undissolved particles, and the residue on paper was dried at 50 °C for 48 h until constant weighing was obtained. Wettability has been accepted as a key parameter for success in wet coating treatment. This parameter gained via the experimental characterization technique was used for an evaluation of the powder properties. The degree of wettability of anhydrous borax powders was measured and compared both after their surfaces were coated with stearic acid and after they were treated with water for a certain period of time in an aqueous environment. The stearic acid coating made the powder hydrophobic and this property was highly preserved after washing.

Journal of Characterization

Surface modification of anhydrous borax with stearic acid by wet coating method

The wet coating of anhydrous borax powders with stearic acid (SA) to reverse their inherent hydrophilic surface properties was investigated. The coating procedure was based on the results from a previous study that revealed that the stearic acid solution (2 wt. % SA) mixed for 60 minute at 750 rpm on the magnetic stirrer was sufficient for the surface modification of anhydrous borax. For the experiments, stearic acid powders were first dissolved in water at 80 °C. The mixture obtained by adding anhydrous borax powders to this solution was vigorously mixed on a magnetic stirrer to initiation and completion the surface modification. Each of these solutions was then filtered using a filter paper to separate the undissolved particles, and the residue on paper was dried at 50 °C for 48 h until constant weighing was obtained. Wettability has been accepted as a key parameter for success in wet coating treatment. This parameter gained via the experimental characterization technique was used for an evaluation of the powder properties. The degree of wettability of anhydrous borax powders was measured and compared both after their surfaces were coated with stearic acid and after they were treated with water for a certain period of time in an aqueous environment. The stearic acid coating made the powder hydrophobic and this property was highly preserved after washing.

Journal of Characterization

Effect of cadmium on structure and optical properties of zno nanopowders by sol-gel method

Zn1-xCdxO (x=0, 0.04, 0.06, 0.08) ternary alloys were successfully synthesized by Sol–gel method. The prepared powders were sintered at 800°C for 4hrs. The compositional, structural and optical studies were investigated by SEM equipped with EDS, XRD and UV-Visible Spectroscopy. XRD results were compared with JCPDS data and confirmed the formation of Cd doped ZnO nanoparticles with polycrystalline single phase hexagonal wurtzite structure. The crystallite size was found to decrease from 21 to 17 nm with increase in the concentration of Cd. EDS analysis revealed the existence of Cd content in ternary alloys. From Ultraviolet-visible spectral studies optical band gap vary from 3.21 eV to 3.12 eV with Cd concentration. © 2016 Elsevier Ltd. All rights reserved. Selection and Peer-review under responsibility of International conference on materials research and applications-2016.

MOHAN KUMAR THUMMA KOMMA

Hierarchical temporal memory (htm)approach for fault detection in transmission line

This study was conducted to proposea hierarchical temporal memory (HTM) approach for fault detection in the Onitsha-Alaoji transmission line in Nigeria. Using a mixed research method, the study employed the Hawkins HTM model with two objectives and their corresponding research questions. The study gathered primary and secondary data to detect and evaluate faults in the Onitsha-Alaoji transmission line in Nigeria using HTM and compares its efficacy to current fault detection methods. With the use of simulation and descriptive methods of data analysis, results showed that partial discharge (PD) is the fault type that is being detected and it is commonly found as a fault leading to transmission line errors. More so, fault detection simulations were conducted at 40 km using typical power spectral density analysis. The first fundamental shifted from about 10 kHz to roughly 13 kHz during a fault. The HTM model outperformed sequence learning methods, resulting in a 90% mean test classification accuracy (CA) over extreme learning machine(ELM) and online sequential learning–extreme learning machine (OS-ELM), with OS-ELM performing poorly.The study concluded and recommended that the proposed HTM model be used to identify various PD fault types that plague the Onitsha-Alaoji transmission line in Nigeria. With the increased efficacy and reliability of the proposed model compared to existing methods, it is recommended for future implementation in this transmission line and potentially other fault-prone power transmission lines in Nigeria.

FXintegrity Publishing