Kinetics of Hydrogen Absorption and Desorption in Titanium

Titanium is reactive toward hydrogen forming metal hydride which has a potential application in      energy storage and conversion. Titanium hydride has been widely studied for hydrogen storage, thermal storage, and battery electrodes applications. A special interest is using titanium for hydrogen production in a hydrogen sorption-enhanced steam reforming of natural gas. In the present work, non-isothermal dehydrogenation kinetics of titanium hydride and kinetics of hydrogenation in gaseous flow at isothermal conditions were investigated. The hydrogen desorption was studied using temperature desorption spectroscopy (TDS) while the hydrogen absorption and desorption in gaseous flow were studied by temperature programmed desorption (TPD). The present work showed that the path of dehydrogenation of the TiH2 is d®b®a hydride phase with possible overlapping steps occurred. The fast hydrogen desorption rate observed at the TDS main peak temperature were correlated with the fast transformation of the d-TiH1.41 to b-TiH0.59. In the gaseous flow, hydrogen absorption and desorption were related to the transformation of b-TiH0.59 Û d-TiH1.41 with 2 wt.% hydrogen reversible content. Copyright © 2017 BCREC Group. All rights reserved Received: 21st November 2016; Revised: 20th March 2017; Accepted: 9th April 2017; Available online: 27th October 2017; Published regularly: December 2017 How to Cite: Suwarno, S., Yartys, V.A. (2017). Kinetics of Hydrogen Absorption and Desorption in Titanium. Bulletin of Chemical Reaction Engineering & Catalysis, 12 (3): 312-317  (doi:10.9767/bcrec.12.3.810.312-317

Hubungan Sifat Fisik Tanah dengan Kejadian Longsorlahan di Sub-Das Logawa Kabupaten Banyumas

Landslide is a form of erosion where the transport or movement of the soil mass occurs on a relatively largevolume. A landslide event is known as a ground mass movement. Landslide is influenced by various factors bothinternal and external factors. Internal factors such as soil consist of soil solum, soil texture, soil permeability,depth of weathering, and slope. The purpose of this research is to know the relationship of soil physicalproperties with the occurrence of landslide in Sub-watershed Logawa. The method used in this research is fieldsurvey method. The population in this research is all the form of land in Logawa Sub-watershed of 10 unit ofland form, with sample area sampling technique. The data consists of primary data in the form of soil solum oneach unit of land form. Secondary data such as soil texture data, soil permeability, weathering depth andlandslide events. The data analysis in this study used overlay of land physical properties map and landslideevent. The overlay results are interpreted and manifested in quantitative descriptive form. Most landslide eventsin soil physical properties with solum are very thick, dusty texture dust, permeability rather quickly, and deepdepth of weathering. There were 82 landslide events throughout the study area

Kinetics of Hydrogen Absorption and Desorption in Titanium

Titanium is reactive toward hydrogen forming metal hydride which has a potential application in      energy storage and conversion. Titanium hydride has been widely studied for hydrogen storage, thermal storage, and battery electrodes applications. A special interest is using titanium for hydrogen production in a hydrogen sorption-enhanced steam reforming of natural gas. In the present work, non-isothermal dehydrogenation kinetics of titanium hydride and kinetics of hydrogenation in gaseous flow at isothermal conditions were investigated. The hydrogen desorption was studied using temperature desorption spectroscopy (TDS) while the hydrogen absorption and desorption in gaseous flow were studied by temperature programmed desorption (TPD). The present work showed that the path of dehydrogenation of the TiH2 is d®b®a hydride phase with possible overlapping steps occurred. The fast hydrogen desorption rate observed at the TDS main peak temperature were correlated with the fast transformation of the d-TiH1.41 to b-TiH0.59. In the gaseous flow, hydrogen absorption and desorption were related to the transformation of b-TiH0.59 Û d-TiH1.41 with 2 wt.% hydrogen reversible content. 

IDENTIFICATION OF WIDE COMPATIBILITY VARIETIES IN SOME TROPICAL JAPONICA RICE

The F1 hybrid sterility in indica/japonica crosses is the major barrier in developing hybrid rice varieties between these two diverse germplasm. The sterility problem in japonica/indica hybrids can be overcome by using wide compatibility genes. The objective of this study was to identify wide compatibility varieties (WCVs) in some tropical japonica rice. Twenty five tropical japonica varieties as male parents were crossed with indica (IR64) and japonica (Akitakomachi) testers as female parents. The crosses were planted following a randomized complete block design with three replications. Varieties having average spikelet fertility of more than 70% with both the indica and japonica testers were rated as WCVs. Result from this study showed that six tropical japonica varieties were classified as WCVs, i.e., Cabacu, Grogol, Kencana Bali, Klemas, Lampung Lawer, and Napa. Hybrid sterility is caused by partial sterility of male and female gametes. The WCVs from the present study can be used in hybrid rice breeding program to solve hybrid sterility in indica/japonica hybrids

Pengaruh Pengelolaan Kelas terhadap Pembelajaran Efektif di Kelas V SD Negeri 50 Banda Aceh

Kurang menguasai pengelolaan kelas adalah salah satu penyebab tidak tercapaianya pembelajaran yang efektif. Penelitian ini mengangkat masalah Apakah ada pengaruh antara pengelolaan kelas dengan pembelajaran efektif di kelas V SD Negeri 50 Banda Aceh. Penelitian ini bertujuan untuk mengetahui pengaruh antara pengelolaan kelas dengan pembelajaran efektif di kelas V SD Negeri 50 Banda Aceh. Hipotesis penelitian yakni terdapat pengaruh antara pengelolaan kelas dengan pembelajaran efektif di kelas V SD Negeri 50 Banda Aceh.Penelitian ini menggunakan jenis penelitian korelasi dengan pendekatan kuantitatif. Penelitian ini dilakukan di kelas V SD Negeri 50 Banda Aceh dengan populasi sebanyak 140 siswa dan sampel sebanyak 104 siswa. Populasi diambil dari 4 kelas, yaitu kelas VA, VB, VC, dan kelas VD. Instrumen yang digunakan adalah angket tertutup dari masing-masing variabel dengan menggunakan skala likert. Uji reliabilitas dan uji prasyarat analisis menggunakan SPSS 16.0. Pengujian hipotesis menggunakan uji korelasi Product Moment dengan bantuan SPSS 16,0. Berdasarkan hasil analisis data diperoleh gambaran pengelolaan kelas pada kriteria tinggi dengan rata-rata 136,99 dan frekuensi relatif 60,4% dan pembelajaran efektifberada pada kriteria tinggi dengan perolehan rata-rata 94,97 dan frekuensi relatif 58,92%. Hasil penelitian menunjukkan bahwa terdapat pengaruh yang signifikan antara pengelolaan kelas dengan pembelajaran efektif di kelas V SD Negeri 50 Banda Aceh. Terbukti dari hasil analisis korelasi antara pengelolaan kelas dengan pembelajaran efektifdiperoleh nilai korelasi 0,714 > 0,1927 dan signifikan 0,000 < 0,005. Ini berarti bahwa terdapat pengaruh positif yang signifikan antara pengelolaan kelas dengan pembelajaran efektif

Correlation Analysis of Agronomic Characters and Grain Yield of Rice for Tidal Swamp Areas

Development of rice varieties for tidal swamp areas is emphasized on the improvement of rice yield potential in specific environment. However, grain yield is a complex trait and highly dependent on the other agronomic characters; while information related to the relationship between agronomic characters and grain yield in the breeding program particularly for tidal swamp areas is very limited. The objective of this study was to investigate relationship between agronomic characters and grain yield of rice as a basis for selection of high yielding rice varieties for tidal swamp areas. Agronomic characters and grain yield of nine advanced rice breeding lines and two rice varieties were evaluated in a series of experiments in tidal swamp areas, Karang Agung Ulu Village, Banyuasin, South Sumatra, for four cropping seasons in dry season (DS) 2005, wet season (WS) 2005/2006, DS 2006, and DS 2007. Result from path analysis revealed that the following characters had positive direct effect on grain yield, i.e. number of productive tillers per hill (p = 0.356), number of filled grains per panicle (p = 0.544), and spikelet fertility (p = 0.215). Plant height had negative direct effect (p = -0.332) on grain yield, while maturity, number of spikelets per panicle, and 1000-grain weight showed negligible effect on rice grain yield. Present study suggests that indirect selection of high yielding tidal swamp rice can be done by selecting breeding lines which have many product tive tillers, dense filled grains, and high spikelet fertility

Identification of Wide Compatibility Varieties in Some Tropical Japonica Rice

The F1 hybrid sterility in indica/japonica crosses is the major barrier in developing hybrid rice varieties between these two diverse germplasm. The sterility problem in japonica/indica hybrids can be overcome by using wide compatibility genes. The objective of this study was to identify wide compatibility varieties (WCVs) in some tropical japonica rice. Twenty five tropical japonica varieties as male parents were crossed with indica (IR64) and japonica (Akitakomachi) testers as female parents. The crosses were planted following a randomized complete block design with three replications. Varieties having average spikelet fertility of more than 70% with both the indica and japonica testers were rated as WCVs. Result from this study showed that six tropical japonica varieties were classified as WCVs, i.e., Cabacu, Grogol, Kencana Bali, Klemas, Lampung Lawer, and Napa. Hybrid sterility is caused by partial sterility of male and female gametes. The WCVs from the present study can be used in hybrid rice breeding program to solve hybrid sterility in indica/japonica hybrids