1,720,980 research outputs found
UTILIZATION OF MULTIWALLED CARBON NANOTUBE/POLY(p- PHENYLEME) COMPOSITE FOR GAS DETECTION
Full text linkOne problems emerging in modern live is how to detect the exsistence of a gas in
a room or space. The detection could be achieved by a sensor. The motivation of this
work is to develop a sensor material consist of multiwalled carbon nanotubes(MWTNTs),
polymers, and metal oxides. Recently the combination of CNTs and polymer or metal
oxides gains serious attention since the CNTs have unique electrical properties.
Poly(p-phenylene) (PPP) is known as a potential conductive polymer due to the
exsistance of double bond. Based on information in publisherd reports, the synthesizing
of the PPP and the metal oxide successfully conducted. To observe comprehensively of
materials synthesized,several characterization were conduction to get a kind of composite
as a sensor material. Several variables such as sonication time, amount of dipersants,
types of gas, and gas concentration were varied to investigate the performance of the
composite.
A certain ratio of MWNTs with nominal size of 20 nm and synthesized-PPP was
compounded with the presence of terpineol as a dispersant. To investigate an optimal
condition for homogenizing all constituents, ultrasonication with 750 watts was
employed with compounding time of 3, 10, 20, 30 min. It was found that the composite
film could be prepared with ultrasonication within 10 minutes. The ratio of constituens
and dispersants was also conducted. The composite was put into a system of sensing by
wich the response of the sensor material recorded automatically every second. Avery
important conclusion of this study is that the combination of MWNTs and PPP and
tungsten oxide could be used as a sensor material. Typical results show that sensitivity of
MWNTs was more than 40%.11-15% for MWNT/WO3, and 12-30% for
MWNT/PPP/W03
KOMPOSISI MIKROSKOPIS BATUBARA SEAM WARA, FORMASI WARUKIN, DAERAH TANJUNG, KABUPATEN TABALONG, KALIMANTAN SELATAN
No full textSARI - Secara umum batubara mempunyai karakteristik komposisi maseral yang hampir sama. Hal inidisebabkan karena bahan pembentuk batubara (tumbuhan) serta parameter kondisi pengendapannyayang relatif sama (tropis) walaupun letaknya terhampar luas di wilayah Indonesia dengan kondisigeologi yang beragam. Salah satu lokasi keterdapatan batubara adalah di daerah Tanjung, KabupatenTabalong, Kalimantan Selatan termasuk dalam Cekungan Barito. Formasi pembawa batubara didaerah Tanjung adalah Formasi Warukin yang berumur Miosen Tengah-Awal sasaran penelitianadalah pada Seam Wara, dengan rata-rata komposisi maseral batubara untuk grup maseral vitrinite83,28% (vol.), liptinite 8,49% (vol.) dan inertinite 4,1% (vol.) serta rata-rata kehadiran mineral matter5,13 % (vol.). dengan rata-rata Reflektan Vitrinite random (Rr) 0,34%. Hasil analisis terhadapreflektansi batubara menunjukkan hasil Rank Batubara Tanjung adalah Sub-Bituminus. Kandunganliptinit pada batubara Seam Wara yang relatif tinggi (rata-rata 8,49 % Vol.) menunjukkan potensiuntuk pemanfaatan proses pencairan batubara menjadi minyak.Kata-kata kunci: maseral, vitrinite, liptinite, inertinite, reflektan vitrinite, mineral matter, subbituminus,pencairanbatubara.
Pengaruh Oil Sludge Pertamina Surabaya Terhadap Kuat Tekan Keramik Tradisional
Full text link Oil sludge is the solidifying oils that lying on the open space around the fuel storage tank. Heaps of the waste continues to increase could lead to environmental pollution due to the waste containing heavy metal. This research aims to study the effect of oil sludge on the compressive strength of traditional ceramics within range of sintering temperature (600- 1000 0 C), sintering time (1-3 hours), and raw material compositions. The experiment begins by mixing the ceramic raw materials. Material was mixed with water and milled using Mortar Hand (milling). A cermic mold was used to get ceramic specimens. The mold dimension is length of 8 cm, 4 cm wide, and 2 cm high. The specimens were sintered in a furnace at different temperatures and holding time. Finally, the ceramics were observed its compressive strength. The results showed that the waste oil sludge can be involved in the manufacture of traditional ceramics. In the view of the compressive strength, the best conditions for fabricating traditional ceramics are oil sludge of 16.67% w., sintering temperature of 800 0 C, and sintering time of 2.5 hours
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Pengembangan Teknologi Bersih berbasis Hidrogen menggunakan Sumber Daya Alam
Full text linkGlobal warming has correlation with CO2 emissions. The emission coupled with rising energy prices led to concerns
of people. Those problems are critical issues to encourage steps for reducing the risk to humans and the
environment. One of the important efforts to achieve clean technology is to replace fossil-based energy with
renewable-based energy system and to develop non-carbon based energy. One type of non-carbon based energy is
hydrogen fuel cell (Proton Exchange Membrane Fuel Cell, PEMFC). The studies of the development of hydrogen
fuel cell (FC) at this time lead to the provision of hydrogen, the discovery of non-platinum catalyst, and the finding
of fabrication methods of PEMFC. The acquiring of raw material for non-platinum catalyst and hydrogen using
local raw material is an important effort to reduce the cost of fuel cell system. Non-platinum catalyst is much
cheaper than platinum and more resistant to CO poisoning. The catalyst candidate is selected from the class of
transition metals as active components of supported by the substituted N-Carbon Nano Tube (CNT). In FC system,
electrodes are made by coating method in which carbon paper as a substrate with a liquid (sol) which contains
catalyst precursors, transition metal catalyst, N (Dimethyl Formamide), and C of resorcinol- formaldehyde. Using
this method, catalyst-candidate in liquid phase coated onto the carbon paper which as a substrate. Then the
substrate need drying for sol changed into a gel. To activate the catalyst, substrate with the candidate of the catalyst
must be pyrolysed in order to obtain an expected catalyst (transition metal / CNT / N). When the catalyst attach to
the substrate (carbon paper), the catalyst could be a distributor of hydrogen and oxygen moving to the catalyst
surface. The direct coating method would produce the electrode with a certain thickness of catalyst. The certain
thickness can be controlled by adjusting the composition of the components in the sol and during pyrolysis and
reduction processes. Therefore the electrode with non-platinum catalysts that has similar performance and stability
with platinum catalyst could be achieved. Thus the results of this study might be an idea to solve the problem of the
mass production of PEMFC with lower production cost.
Keyword: PEMFC, energi terbarukan, katalis non platina, CVD, sol-gel organi
PKM KELOMPOK TERNAK BERBASIS BIOGAS SEBAGAI ALTERNATIF ENERGI RAMAH LINGKUNGAN UNTUK UPAYA PEMBERDAYAAN MASYARAKAT DESA SUMBERARUM D.I YOGYAKARTA
Full text linkDesa Sumberarum adalah salah satu desa yang berada di wilayah Kecamatan Moyudan, Kabupaten Sleman, Daerah Istimewa Yogyakarta. Penduduk dari desa ini sebagian bermata pencaharian sebagai petani dan peternak. Peternakan merupakan komoditas unggulan di Desa Sumberarum. Terdapat hewan-hewan ternak yang menjadi potensi sumber daya di Desa Sumberarum yakni sapi, kambing, dan ayam. Salah satu dampak adanya peternakan adalah menghasilkan limbah yang dapat mencemari lingkungan. Oleh sebab itu, penulis merumuskan program kemitraan untuk kelompok ternak berbasis pengolahan kotoran ternak menjadi biogas dan pupuk organik. Tujuan dari program ini untuk menerapkan teknologi pengolahan limbah hewan ternak sehingga dapat menghasilkan produk yang bermanfaat bagi masyarakat yaitu biogas dan pupuk organik. Produk tersebut dapat dimanfaatkan oleh masyarakat Desa Sumberarum untuk memenuhi kebutuhan akan bahan bakar dan membuka UMKM yang baru sehingga dapat meningkatkan kesejahteraan masyarakat. Metode yang digunakan dalam pelaksaan program ini yakni model pemberdayaan masyarakat partisipatif. Hasil yang diperoleh yaitu teknologi yang modern sehingga limbah hewan ternak yang sebelumnya dianggap tidak memiliki nilai, dapat dimanfaatkan menjadi produk bernilai jual. Produk akhir yang dapat dihasilkan dari berupa biogas dan pupuk organik yang diharapkan dapat bermanfaat dan memberdayakan masyarakat Desa Sumberaru
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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