62 research outputs found
A review of g-C3N4 based catalysts for direct methanol fuel cells
No full textDirect methanol fuel cells (DMFC) possess numerous advantages for powering portable mobile devices. However, there are still major challenges in their development and commercialization that originates from the anode catalyst responsible for methanol oxidation reaction. This has motivated researchers to find a cost effective and durable catalyst material for methanol oxidation. Recently, carbon-based 2-D graphitic carbon nitride (g-C3N4) has been found to have good potentials to catalyse alcohol oxidation reactions in fuel cells. This review provides a summarized information of previously developed g-C3N4-containing-electrocatalysts based on the active sites present (e.g., non-metals, noble metals, and non-noble metals) for methanol electro-oxidation to compare their electrocatalytic performance. It also consists of brief examination of their structure, description of different synthesis methods and post-synthesis treatments, and evaluation of their properties that contributes to their resulting performance. The review then concludes with the details of challenges and possible solutions that enable DMFC to be a reliable source of energy in the future.The author(s) would like to acknowledge the support from Qatar University internal grant QUCG-CENG-19/20-7 .Scopu
A comprehensive and critical review on recent progress in anode catalyst for methanol oxidation reaction
No full textThe synthesis of anode electrocatalyst with high activity and durability for methanol oxidation reaction has been one of the main focuses of researchers in recent years. Several works are reviewed in this paper to summarize and compare the performance of electrocatalysts comprising of noble and non-noble metals. The effect of manipulating catalysts by introducing nanostructured morphology, metal alloys, support materials, acidic or basic electrolyte, and synthesis methods are also examined. The paper finally concludes with details of challenges that are generally faced in making direct methanol fuel cell (DMFC) a reliable source of energy for future prospects, and the approach to be taken to reduce the complexity in synthesizing new generations of anode electrocatalysts.This publication was made possible by NPRP grant (NPRP8-145-2-066) from the Qatar National Research Fund (a member of Qatar foundation). The statements made herein are solely the responsibility of the author(s). The author(s) would also like to acknowledge the support from Qatar University internal grant QUCG-CENG-19/20-7. Open Access funding provided by the Qatar National Library.Scopu
ANALISIS ZONASI GERAKAN TANAH PADA DAERAH CIPINANG, KECAMATAN RUMPIN, KABUPATEN BOGOR: ZONING ANALYSIS OF LAND MOVEMENT IN THE CIPINANG AREA, RUMPIN DISTRICT, BOGOR DISTRICT
No full textThe research was conducted in the Cipinang area, Rumpin District, Bogor Regency, West Java Province, which has regional conditions with varied morphology consisting of lowlands to highlands. From the existing geological conditions, the Cipinang area is an area with moderate to high susceptibility to landslides. One of the influencing factors is the slope from sloping to steep, and high rainfall. The aim of this research is to determine the ground movement vulnerability zone in the research area using a deterministic method in order to produce a map of the ground movement vulnerability zone using parameters that cause ground movement. with the final results obtained in the research area being divided into 3 zones, namely the low has coverage of 50%, the medium zone 40% and the high zone 10%
Recent advances in cobalt based heterogeneous catalysts for oxygen evolution reaction
No full textThe future of the world energy lies in clean and renewable energy sources. Many technologies, such as solar cells, wind turbines, etc., have been developed to harness renewable energies in different forms of fuel. Amongst them, electrolysis of water to produce oxygen and hydrogen is one of the paramount developments towards achieving clean energy, which has attained significant attention due to its green and simple method for the production of fuels. In electrolysis of water, the half-reaction containing the oxygen evolution reaction (OER) is a reaction that is kinetically sluggish, which requires higher overpotential to produce O2, when compared to the other half-reaction, i.e. hydrogen evolution reaction (HER). Many electrocatalysts are studied extensively to be used in the OER process to get an economical yield out of it. Noble metal-based catalysts are the state-of-the-art catalyst used for OER currently. But due to their high cost and scarcity, they cannot be applied in a large-scale manner to be used in the future. The non-noble metals (transition metals and perovskites) are gaining interest by exhibiting on par or better OER performance compared to the noble metal used. Due to their low cost, ample resources, and several metals available, they have opened up a variety of areas with a different combination of metals to be used as a catalyst for OER. Amongst these metals, cobalt has received massive appreciation for performing as an excellent OER catalyst. Multi metals, multimetal mixed oxides, multimetal phosphides, perovskites, and carbon-supported catalysts containing cobalt have shown low overpotential with high long-term stability. Therefore, in this review, we go through different cobalt-based electrocatalysts for OER, the general mechanism governing the OER process, the challenges that we are facing today to enhance the catalytic performance, and future aspects to overcome such challenges.This study was supported by the NPRP grant ( NPRP8-145-2-066 ) from the Qatar National Research Fund (a member of the Qatar Foundation). The statements made herein are solely the responsibility of the authors. The author(s) would also like to acknowledge the support from Qatar University 's internal grant QUCG-CENG-19/20-7 .Scopu
Highly efficient methanol oxidation reaction on durable Co9S8 @N, S-doped CNT catalyst for methanol fuel cell applications
No full textThe implementation of direct methanol fuel cells is seen as a reliable factor in the future energy mix. Efficient energy conversion from methanol requires an active and durable catalyst to drive the anodic methanol oxidation reaction (MOR) in direct methanol fuel cells. As an alternative to high cost noble metals, cobalt-based electrocatalysts are considered potential replacements that meet the high activity and long-term stability for MOR. Herein, we report the preparation of hierarchical Co9S8 nanowires trapped in N-doped carbon nanotubes (N,S-Co@CNT) derived from melamine showing high activity for MOR in alkaline medium. In order to identify the main active sites, we synthesized cobalt particles embedded in carbon structures in absence of a sulphur source (Co@CNT) and evaluated its performance for MOR. The material characterization shows that adding sulphur during pyrolysis enhances the surface area, pore size and lattice defect. In addition, the morphology changes from hemi-spherical particles to nanowires, that significantly improves the electrochemical properties. The current density of N,S-Co@CNT is exceptionally higher (5.5 times) and the onset potential of MOR is shifted to lower potential when compared to Co@CNT. The enhanced activity, durability and stability of N,S-Co@CNT is ascribed to the unique hierarchical structure and surface properties.This publication was made possible by the NPRP grant ( NPRP8-145-2-066 ) from the Qatar National Research Fund (a member of Qatar Foundation). The statements made herein are solely the responsibility of the author(s). The authors also appreciate the help from Gas Processing Center (GPC), Center of Advanced Materials (CAM) at Qatar University for XPS and XRD characterizations. The SEM analysis was accomplished at the Central Laboratories Unit (CLU) Qatar University. The authors would also like to thank QEERI Core Labs for the TEM characterization.Scopu
PERLINDUNGAN HUKUM TERHADAP SAKSI DAN KORBAN DALAM TINDAK PIDANA PENGANIAYAAN DI PENGADILAN NEGERI SLEMAN
No full textThis research aims to obtain data on the protection of witneses and
victims of criminal acts of maltreatment in sleman state court, the type of
normative research based on research conducted by author, get result that
conclueded the judge always do legal protection against witnesses and victims in
examing criminal prosecuition case in sleman state court, as for suggestions given
by the author, based on the results of research and analysis conduted by author, the
author suggest in the examination of testimony of witneses and victims in the case
of persection, witneses and victims are disguised identity, so that the defendant Is
not known
Effectiveness of Digital Educational Materials for Developing Spatial Thinking of Elementary School Students
No full textAbstractTo develop elementary school students’ spatial thinking and support classes on social studies, especially in geography field, the author developed flash-based puzzle video games of a map of Japan and examined the effectiveness of the application. In this study 28 students of fourth grade elementary school tried to play once a week for three weeks. At first only 20 percent of them could finish solving the puzzle within 5minutes, but after 3 weeks, 80 percent of them could finish in 5minutes in less. Furthermore, in a paper-based test students were asked to find prefectures on the map of Japan before and after these experiments and 70 percent of students had better scores at the post experiment test. Students acquired the skill to think identification of shapes, location and letters as spatial information through playing this map puzzle game. These results indicate that the game applications as digital education materials have effects on fostering elementary school students’ spatial thinking, widening their views and also supporting geography education
EFEKTIVITAS PASAL 10 AYAT (1) PERATURAN DAERAH KOTA MATARAM NOMOR 4 TAHUN 2013 TENTANG KAWASAN TANPA ROKOK ( STUDI DI PURA DI KOTA MATARAM )
No full textI Gusti Bagus Yuda Perawira, Lutfi Effendi, S.H., M.Hum, Arif Zainudin, S.H., M.Hum Fakultas Hukum Universitas Brawijaya Email: [email protected]  Abstrak Penelitian ini bertujuan mendiskripsikan Efektivitas Pasal 10 ayat (1) Peraturan Daerah Kota Mataram Nomor 4 tahun 2013 tentang Kawasan Tanpa Rokok. Penelitain ini bersifat yuridis empiris Dalam penelitian ini penulis melakukan penelitian terhadap efektivitas hukum merupakan penelitian yang membahas bagaimana hukum beroperasi dalam masyarakat. Penelitian ini menggunakan metode pendekatan yuridis sosiologis. Peneliti melakukan penelitian sosio legal karena peneliti meneliti mengenai efektivitas pasal 10 ayat (1) Perda KTR Kota Mataram bagaimana suatu peraturan tersebut berlaku didalam masyarakat serta hambatan apa saja yang terjadi serta bagaimana upaya penanggulangan dari hambatan tersebut. Teknik analisis data adalah dengan mengelompokan data dan informasi kemudian melakukan interpretasi dan menarik kesimpulan secara induktif secara empirik efektivitas pasal 10 ayat (1) peraturan daerah nomor 4 tahun 2013 tentang kawasan tanpa rokok namun kenyataannya efektivitas pasal 10 ayat (1) peraturan daerah nomor 4 tahun 2013 tentang kawasan tanpa rokok tidak efektiv, dikarenakan ada beberapa faktor yang tidak berjalan secara maksimal karena adanya hambatan-hambatan seperti pengawasan yang tidak dapat dilakukan secara maksimal serta masyarakat yang melakukan peribadahan di pura menganggap merokok telah menjadi kebiasannya dan budaya dari masyarakat Hindu yang tidak mengenal sesuatu dilarang ataupun dilarang. Sejauh ini upaya dari ketua krama pura yang sebagai penegak hukum telah melakukan kordinasi didalam melakukan pengawasan dan sesegera mungkin memasang tanda larangan merokok di pura. Ketua krama pura juga telah melakukan upaya dalam pengedukasian dala bidang hukum, kesehatan dan juga agama serta penyuluhan mengenai Peraturan Daerah Nomor 4 tahun 2013 tentang Kawasan Tanpa Rokok. Kata kunci : Efektivitas, Kawasan Tanpa Rokok, Peraturan Daerah nomor 4 tahun 2013 tentang Kawasan Tanpa Rokok. Abstract This research is aimed to describe the effectiveness of Article 10 Paragraph (1) of Regional Regulation of Mataram Number 4 Year 2013 on Non Smoking Premises. The juridical empirical method was applied in the research in which the way the law works in society was observed. The socio-juridical method was also employed; the socio-legal was used in the research, as the author observed the effectiveness of Article 10 paragraph (1) of Regional Regulation on Non-Smoking Premises in Mataram, how a regulation works in a society, what obstacles are present, and the solutions to the problem. The data of the research were analyzed by grouping data and information before it was interpreted and concluded inductively. Empirically, Article 10 Paragraph (1) of Regional Regulation Number 4 year 2013 on Non Smoking Premises is not effective due to several factors that do not maximally work because there are obstacles such as lack of optimal supervision, and locals still see smoking as a part of Hindu culture which believes there is no need to ban something like smoking. So far, the head of the temple has teamed up with certain parties to control this act and no smoking sign will be soon put at the temple. The head is also trying to educate the locals related to law, health, and religion. Regional Regulation Number 4 Year 2013 on Non-Smoking Premises will also be profoundly introduced to the locals. Keywords: effectiveness, non-smoking premises, regional regulation of municipalityÂ
PENGURANGAN WAKTU SETUP MESIN DRILL DENGAN PENDEKATAN SMED DI PT GATRA MAPAN
No full textJika membutuhkan abstrak atau isi jurnal silahkan menhubungi author melalui email [email protected], [email protected]
Heterogeneous and tissue-specific regulation of effector T cell responses by IFN-gamma during Plasmodium berghei ANKA infection.
No full textIFN-γ and T cells are both required for the development of experimental cerebral malaria during Plasmodium berghei ANKA infection. Surprisingly, however, the role of IFN-γ in shaping the effector CD4(+) and CD8(+) T cell response during this infection has not been examined in detail. To address this, we have compared the effector T cell responses in wild-type and IFN-γ(-/-) mice during P. berghei ANKA infection. The expansion of splenic CD4(+) and CD8(+) T cells during P. berghei ANKA infection was unaffected by the absence of IFN-γ, but the contraction phase of the T cell response was significantly attenuated. Splenic T cell activation and effector function were essentially normal in IFN-γ(-/-) mice; however, the migration to, and accumulation of, effector CD4(+) and CD8(+) T cells in the lung, liver, and brain was altered in IFN-γ(-/-) mice. Interestingly, activation and accumulation of T cells in various nonlymphoid organs was differently affected by lack of IFN-γ, suggesting that IFN-γ influences T cell effector function to varying levels in different anatomical locations. Importantly, control of splenic T cell numbers during P. berghei ANKA infection depended on active IFN-γ-dependent environmental signals--leading to T cell apoptosis--rather than upon intrinsic alterations in T cell programming. To our knowledge, this is the first study to fully investigate the role of IFN-γ in modulating T cell function during P. berghei ANKA infection and reveals that IFN-γ is required for efficient contraction of the pool of activated T cells
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