Modification of Electrical Properties of Silver Nanoparticle

This chapter focuses on the synthesis of silver nanoparticles (AgNPs), AgNP composites, and its role in the structure and electrical properties modification. The research and its various applications of nanoparticles are interesting among others. Silver nanoparticles (AgNPs) are now becoming to take an essential role in the diverse field of application. Establishing the simple and inexpensive of AgNPs is greatly required, since it will also influence it used. Many different methods to obtain AgNPs have been reported. The inducing AgNPs on a various number of other materials has been investigating. We report a brief review of simple AgNP fabrication method at different MSA, PEG, and ultrasonic irradiations regarding its structure and conductivity. We also report the influence of AgNPs on the electrical conductivity of conducting polymers, i.e., PANI, flavonoids of Jatropha multifida L. (JML) and Pterocarpus indicus W. (PIW). It is found that in general, the increase of AgNP concentration gives rise to increase of its electrical conductivity. The conductivity of the AgNPs doped of polymers does not directly reflect by its crystallinity or crystal size. Some exciting aspect of crystal structure and its conductivity are discussed

Synthesis and Structural Analysis of Silicon Carbide from Silica Rice Husk and Activated Carbon Using Solid-State Reaction

Synthesis of Silicon Carbide (SiC) has been performed using a solid-state reaction method. We used silica and activated carbon as raw materials. The silica was synthesized from silica rice husk using an alkali extraction and a sol-gel method. The purified silica was then mixed with the activated carbon at the same ratio, homogenized, and then cold pressed into pellets by adding polyvinyl alcohol to glue them perfectly. The pellets were then sintered in a vacuum of a high-temperature furnace in an inert arc-furnace at 1200, 1300, and 1400 oC for 6 hours. The samples were characterized for their particle size, surface area, phase composition, microstructure, and resistivity. The XRD data analysis showed that the samples are dominated by the SiC phase in the form of 3C-SiC and 6H-SiC, CO (Carbon (II) oxide), and SiO2 phases. The weight fractions of SiC samples were respectively fallen to 68, 98, and 69% for 1200, 1300 and 1400 oC sintering temperatures. Keywords: Silicon carbide, silica rice husk, activated carbon, solid-state reactio

Detection of seepage source path location in Selorejo downstream foothill dam using georadar

The monitoring found the seepage at the wall canal at downstream foothill in the Selorejo dam. It is a sign that there is water leakage from the dam. To better understand the path of leakage water, some locations of the dam were scanned using 90 MHz radar. The scanning location was done at three locations, namely at (1) the top, (2) the middle slope downstream hill, and (3) the downstream foothill dam using profiling. All those locations were scanned using the B-scan technique. The methods of analysis employed in this research were a gain profile, bandpass filter, and average subtraction to see the radargram clearly. The results found that there are two paths of seepage that started from the top dam. This path shows clearly at the middle slope dam, and this path is unified along before foothill downstream. It implies that seepage might be an early stage of the internal erosion process

SINTESA HYDROXYAPATITE (Ca10(PO4)6(OH)2) BERBASIS BATU KAPUR

<em>Telah dilakukan penelitian tentang sintesa Hydroxyapatite (Ca₁₀(PO₄)₆(OH)₂) menggunakan Batu gamping atau yang disebut dengan batu kapur. Batu kapur selain dimanfaatkan sebagai bahan bangunan juga dapat dimanfaatkan sebagai bahan dasar dalam pembuatan Hydroxyapatite yang dapat digunakan sebagai tulang buatan. Batu kapur yang kandungan utamanya adalah kalsium dalam bentuk CaCO₃ dapat digunakan sebagai bahan dasar pembuatan Hydroxyapatite yang digunakan sebagai sumber kalsium. Dalam pembuatan Hydroxyapatite sumber utama yang dibutuhkan adalah Ca dan P. Dalam pembuatan Hydroxyapatite batu gamping dilarutkan terlebih dahulu dengan air. Batu gamping yang diperoleh kemudian ditambahkan HNO₃. Larutan yang diperoleh ditambahkan  Diamonium Hydrogen Phosphate sebagai sumber P dan dalam prosesnya kondisi dijaga dalam keadaan basa. Hasil yang diperoleh dilakukan variasi pH dan variasi suhu pemanasan yang kemudian dianalisis dengan XRD dan XRF. Hydoxyapatite yang diperoleh memiliki pH optimal dalam pembuatannya yaitu pada pH10 yang dilihat dari hasil analisis menggunakan High Score Plus dari hasil XRD yang memiliki score 22. Dalam variasi suhu pemanasan, kondisi pembuatan digunakan pH 10 dan dari hasil yang diperoleh suhu optimum dalam memanaskan hasil Hydroxyapatite adalah suhu 700°C selama 3 jam dengan score 49 yang hampir mirip dengan Hydroxyapatite sintetik yang memiliki score 59.</em

Shockley’s Equation Fit Analyses for Solar Cell Parameters from I-V Curves

Some of the technical problems that appear are obtaining solar cell parameters from I-V curve measurement data. One simple method is using linear graphical fit at zero current or voltage conditions. Although the accuracy of the obtained values is acceptable, other problems may arise regarding the number of parameters which could be obtained. We report a comparison between manual or graphical fit and fit using Shockley’s equation. The single I-V curve under the lighting was inferred to obtain the intrinsic parameters of the solar cells’ performance. The fittings were performed using the nonlinear equation of Shockley by determining some initial values of fittings such as Rs, Rsh, n, I0, Iph, and T. In the case of the Shockley equation fit, the iteration was performed several times to obtain the least possible inferred parameters. We have successfully obtained a better result of nonlinear Shockley fitting compared to the manual linear fit