Synthesis Of Ultrafine Ba07 Sr0.3 TiO3 by Mechanically Activating Process.

The project 'Synthesis of Ultrafine Ba0.7 Sr0.3 TiO3 by Mechanically Activating Process' was successfully completed early 2008. As reported in the technical report attached, the single phase BST was produced successfully at a relatively low temperature of 500oC, albeit the challenges encountered during the synthesis, one of which is the caking problem as well as melting of phase formed. The caking effect was due to the mechanical activation process, while the melting phase was a result of the low meting chemicals used

Structural, Microstructural, Electrical Properties of Lanthanum doped-Bismuth Titanate Ceramics Prepared by Low Temperature Combustion Synthesis

In this work, lanthanum doped-bismuth titanate with different contents were successfully prepared by low-temperature combustion synthesis, and subsequently, sintered at 1000 oC for 3 hours. Their structural, microstructural and electrical were systematically studied. It was found that the structural distortion of orthorhombic structure tends to transforms to a tetragonal with the increase in La content.This change is most probably due to relaxations of orthorhombic distortion and octahedral tilting because of the difference in the ionic radius of Bi3+ and La3+. Upon increasing of La content, the grain size remarkable decreases resulted in uniform grain size with better relative density. Thus, the electrical properties of La doping were greatly improved in comparison to pure sample

Solid State Synthesis Of Barium Strontium Titanate At 850oC From Mechanically Activated BaCO3-SrCO3-TiO2 Mixture.

The influence of mechanical activation on the solid state reaction to synthesis Ba0.70Sr0.30TiO3 was studied. Thermal analysis of the raw materials and the activated BaCO3-SrCO3-TiO2 mixture was carried out

Current Issues and Problems in the Joining of Ceramic to Metal

Ceramics and metals are two of the oldest established classes of technologically useful materials. While metals dominate engineering applications, ceramics have some attractive properties compared to metals, which make them useful for specific applications. The properties of individual ceramics and metals can vary widely; however, the characteristics of most materials in the two classes differ significantly. Joints between a metal and ceramic are becoming increasingly important in the manufacturing of a wide variety of technological product. But joining ceramics to metallic materials often remains an unresolved or unsatisfactorily resolved problem. This chapter deals with problems of various studies in recent years on the joining between two materials

Linewidth characteristics of un-cooled fiber grating Fabry–Perot laser controlled by the external optical feedback

The effect of external optical feedback (OFB) on the linewidth characteristics of un-cooled laser module is theoretically investigated. This laser that consists of a Fabry–Perot (FP) laser diode and fiber Bragg grating (FBG) realizes stable operation and relatively low-cost solution. The effects of external OFB and temperature on linewidth are calculated according to their effect on threshold carrier density (Nth). The temperature dependence (TD) of linewidth characteristics is calculated according to TD of laser parameters instead of well-known Parkovin relationship. Results show that, linewidth decreases as the external OFB reflectivity (Rext) increases. A narrow linewidth which is less than 3 kHz is obtained for Rext ≥ 0.5. In addition, the linewidth is not largely affected by temperature as compared to the DFB lasers. Also, we found that the linewidth temperature coefficient is 0.04 kHz/°C, which is small enough in comparison to 18.5 kHz/°C for the DFB laser

The Content Analysis Study of Geo-Heritage Conservation: Kilim Karst Geoforest Park, Langkawi

Geopark was a widely known concept for the global theme for promoting the tourism industry. It’s protecting the world heritage and improving the socioeconomic development of the local community. Currently, Geopark area was not excluded from the impact of modernization and rapid development.  Geopark had faced a lot of risk and challenges of losing their identity and damages on historical assets due to an increasing demand for development. Therefore, Geopark area should be well managed and protected with strategic planning and approach. By using the content analysis technique, this research will determine the suitability and current sustainable conservation approach which suits the standard criteria and guidelines that have been set by UNESCO.Keywords: Cultural heritage; Geo-heritage; Geopark; tourism.ISSN: 2398-4287© 2017. The Authors. Published for AMER ABRA by e-International Publishing House, Ltd., UK. This is an open access article under the CC BYNC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer–review under responsibility of AMER (Association of Malaysian Environment-Behaviour Researchers), ABRA (Association of Behavioural Researchers on Asians) and cE-Bs (Centre for Environment-Behaviour Studies), Faculty of Architecture, Planning & Surveying, Universiti Teknologi MARA, Malaysia

The Effect of Microwave Sintering on the Microstructure and Properties of Calcium Phosphate Ceramic

AbstractDespite good ability to improved biological affinity and activity of calcium phosphate (CP) ceramic to the surrounding host tissue when implanted, CP ceramic is capable to encourage direct bond with bone as their chemical compositions are similar to the mineral phase of bone. However, the low mechanical property of CP ceramic restricts use in load-bearing applications. Therefore, the primary aim of this study was to fabricate dense CP ceramic via used of microwave sintering analyze the microstructure and mechanical properties comparison to conventional ceramic sintering. The sintered specimens were characterized by their surface microstructure, density measurement and hardness test. The result demonstrated that the density and hardness values of sintered CP ceramic specimens by microwave sintering were higher than conventional sintering. The microstructures of CP ceramic microwave sintered specimens show also better microstructures (analyzed by FESEM technique), with fines grain size and the present of apatite layer growth on the surface when examined with SBF solution. It can be concluded that the microwave sintering enhanced better microstructure and mechanical properties of CP ceramic

Characterization of Small-Signal Intensity Modulation of Single-Mode Fiber grating Fabry¿Perot Laser Source.

A comprehensive study on the small-signal intensity modulation (IM) characteristics of a fiber grating Fabry-Perot (FGFP) laser is numerically investigated. The effect of external optical feedback (OFB), temperature, injection current, cavity volume, nonlinear gain compression factor, and fiber grating (FG) parameters on IM characteristics are presented. The temperature dependence (TD) of IM is calculated according to the TD of laser cavity parameters instead of using the well-known Parkove relationship. It has been shown that the optimum external fiber length (L ext) is 3.1 cm. The optimum range of working temperature for FGFP laser is between 23 to 27 °C. We also show that by increasing the laser injection current from 10 to 60 mA, the IM peak amplitude decreased from 6.3 to 0.2 dB and the relaxation-oscillation frequency (ROF) is shifted from 1.2 GHz towards higher frequency of 5.48 GHz. In addition, the AR coating reflectivity and gain compression factor have no significant effect on the IM. The study indicates that a stable operation and excellent modulation characteristic can be obtained after optimization process

Relative Intensity Noise Reduction by Optimizing Fiber Grating Fabry-Perot Laser Parameters.

A set of nonlinear rate equations that can describe an external cavity laser with any arbitrary external optical feedback (OFB) level are derived. A comprehensive study on the relative intensity noise (RIN) characteristics of a fiber grating Fabry-Perot is performed numerically. In this paper, fiber Bragg grating (FBG) is used as a wavelength lasing selective element to control the external OFB level, thereby control the RIN. In addition to the external OFB level, the effect of other external cavity parameters such as temperature, injection current, cavity volume, gain compression factor, and FBG parameters on RIN characteristics is investigated. The temperature dependence (TD) of RIN is calculated according to TD of laser parameters instead of well-known Parkove relationship. Results show that by optimization, the peak value of the RIN can be reduced down to around -150 dB/Hz. The optimum and the shortest external cavity length that provides the minimum RIN is found to be around 3.1 cm. In addition, by optimization, the relaxation oscillation frequency of RIN spectra is shifted toward around 5.6 GHz

Persepsi masyarakat terhadap rawatan alternatif Islam: satu kajian kes di negeri Selangor D.E / Khadher Ahmad et al.

Bermula akhir tahun 1960, para pemikir Islam mula memperkenalkan “Traditional Arabic and Islamic Medicine (TAIM)” sebagai alternatif utama bagi model “bio-medical” bawaan Barat. Dalam rawatan Islam, penyakit tidak ditafsirkan secara harfiah. Penyakit yang menghinggapi seseorang dilihat dari dimensi berbeza. Penyebab utama adalah kurang keprihatinan terhadap aspek spiritual sehinggakan elemen sebab dan akibat perlu diambil perhatian. Justeru, perubatan secara Islam mempromosikan fokus utama rawatan berasaskan “faith-healing” melalui solat dan bacaan al-Qur’an. Peningkatan populariti dan penggunaan rawatan alternatif Islam yang semakin meluas khususnya di Malaysia, jelas memberi signifikan kepada polisi kesihatan awam semasa. Perkembangannya diakui memberi impak kepada penurunan masalah kesihatan dalam komuniti. Walaubagaimanapun, sehingga kini ‘baseline data’ berkenaan rawatan alternatif Islam adalah sangat terhad dan menjadi keperluan mendesak untuk menyediakannya. Hal ini penting bagi memahami “pattern” Islamic medicine yang sedia wujud di Malaysia amnya. Melihatkan kepentingannya, artikel ini memfokuskan analisis terhadap persepsi masyarakat dari sudut pengetahuan tentang khidmat rawatan Islam yang ditawarkan, pengamalnya, khidmat rawatan disediakan dan masa depan pusat rawatan Islam. Para responden terdiri dari para pesakit yang mengunjungi pusat rawatan alternatif di sekitar negeri Selangor. Berdasarkan edaran borang soal selidik yang dilakukan, pengkaji mendapati persepsi masyarakat terhadap prospek berhubung rawatan alternatif Islam di negeri Selangor amat memberangsangkan. Hal ini menunjukkan kepekaan dan sokongan masyarakat terhadap keperluan pusat rawatan alternatif Islam. Meskipun begitu, masih terdapat beberapa sudut yang perlu dipertingkatkan untuk mewujudkan medium perubatan Islam yang lebih berwibawa. Antaranya berkait memperhalusi kebolehan perawat dalam merawat penyakit, penyeliaan kaedah rawatan pesakit, menambah skop rawatan yang disediakan di pusat rawatan dan meningkatkan kredibiliti pusat rawatan Islam untuk menjadi lebih dominan dan mampu menyaingi institusi perubatan sedia ada