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Optimasi Kinerja Kombinasi Adsorben dalam Mereduksi Logam Besi dan Nikel Sampel Air
Full text linkClean water or drinking water is one of the supporting materials for the survival of living things, especially humans, which should be free from heavy metal contamination and pose no risk to health. In an effort to reduce heavy metal levels in improving water quality through simple techniques and based on natural ingredients, the authors use jackfruit skin and natural zeolite as adsorbents. The purpose of this study was to determine the adsorption capacity of activated carbon from jackfruit skin combined with natural zeolite in reducing the concentration of iron (Fe) and nickel (Ni). The research was conducted on a laboratory scale using the method of varying the concentration of activated carbon which was analyzed using Atomic Absorption Spectrophotometry (AAS). The optimum adsorption power in reducing the concentration of Fe metal occurs in the x:y composition with the adsorbed concentration (mass of analyte) of 0.4083 ppm (0.1021 mg) for 60 minutes. Meanwhile, Ni metal was found in a combination of 2x:y composition dyes with the adsorbed concentration (mass of analyte) of 0.6017 ppm (0.1504 mg). The adsorption capacity of the adsorbent generally decreased with increasing mass of the dye packaged activated carbon adsorbent both in the analysis of Fe and Ni metal content.Air bersih atau air minum merupakan salah satu bahan penunjang keberlangsungan makhluk hidup terutama manusia dimana seharusnya bebas dari kontaminasi logam berat dan tidak memberikan resiko terhadap kesehatan. Sebagai upaya untuk mengurangi kadar logam berat dalam memperbaiki kualitas air melalui teknik sederhana dan berbasis bahan alam, maka penulis manfaatkan kulit nangka dan zeolit alam sebagai adsorben. Tujuan dari penelitian ini yaitu untuk mengetahui kemampuan daya adsorpsi karbon aktif kulit nangka yang dikombinasikan dengan zeolit alam dalam mereduksi konsentrasi logam besi (Fe) dan nikel (Ni). Penelitian dilakukan dalam skala laboratorium dengan menggunakan metode variasi konsentrasi karbon aktif yang dianalisi menggunakan Spektrofotometri Serapan Atom (SSA). Daya adsorpsi optimum dalam mereduksi konsentrasi logam Fe terjadi pada komposisi x:y dengan konsentrasi (massa analit) yang teradsorpsi yaitu 0,4083 ppm (0,1021 mg) selama 60 menit. Sedangkan logam Ni terdapat pada kombinasi kemasan celup komposisi 2x:y dengan konsentrasi (massa analit) yang teradsorpsi yaitu 0,6017 ppm (0,1504 mg). Kemampuan daya adsorpsi adsorben secara umum menurun dengan bertambahnya massa adsorben karbon aktif kemasan celup baik pada analisis kadar logam Fe maupun Ni
PENINGKATAN RESPON IMUN IKAN NILA (Oreochromis niloticus) DENGAN PEMBERIAN EKSTRAK DAUN Macaranga tanarius
Full text linkThe problem of tilapia farming farmers is the presence of disease, which is caused by viruses, bacteria, fungi, and parasites. Prevention by farmers is the provision of vaccines, antibiotics, and immunostimulants. However, it is only effective in one type of disease. Therefore, alternative prevention is needed with natural ingredients from Macaranga tanarius leaf extract which has tannins, terpenoids, flavonoids, prenylflavonoids, and lignans that have immunostimulator properties. M. tanarius leaf extract was injected by intramuscular injection of tilapia. This research method used a completely randomized design (CRD) with five treatments with three repetitions. Treatment (P1) using physiological solution (positive control), P2 = 4 % (v/v) (1mL extract + 24 mL distilled water), P3 = 8 % (v/v) (2mL extract + 23 mL distilled water), P4 = 12% (v/v) (3mL extract + 22 mL distilled water) and P5 without injection of M. tanarius leaf extract (negative control). The results showed that the leaf extract of M. tanarius could respond to phagocytic activity (45.82%) and increase the number of white blood cells (12.43 x 108 cells/mL). Based on this study, the extract of M. tanarius showed an increase in the immune response of tilapia
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
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
Turunan Senyawa Flavonoid dari Daun Macaranga involucrata (Roxb.) Baill dari Buton Tengah, Sulawesi Tenggara
Full text linkMacaranga merupakan salah satu genus terbesar dari famili Euphorbiaceae yang terdiri dari 300 spesies dengan nama lokal mahang-mahangan. Tumbuhan Macaranga tersebar luas di wilayah Afrika dan Madagaskar di bagian barat hingga ke wilayah tropis Asia, Australia utara dan kepulauan Pasifik. Di Indonesia tumbuhan Macaranga tersebar di beberapa daerah yaitu daerah Papua, Maluku, Sulawesi, Kalimantan, Sumatera, Bangka, dan Jawa. Kajian fitokimia beberapa spesies Macaranga menunjukan adanya kelompok senyawa fenolik yaitu turunan flavonoid dan stilben, serta turunan terpenoid. Senyawa turunan fenolik tersebut memiliki keunikan dari struktur molekulnya, yaitu adanya subtituen tambahan dari metabolit terpenoid yaitu prenil (C5), geranil (C10), farnesil (C15), dan geranilgeranil (C20). Pada penelitian ini telah dilakukan isolasi metabolit sekunder dari daun M. involucrata (Roxb.) Baill dengan metode maserasi menggunakan pelarut aseton, kemudian dilanjutkan pemisahan dan pemurnian dengan menggunakan kromatografi cair vakum dan kromatografi radial untuk mendapatkan senyawa murni. Penentuan struktur dilakukan berdasarkan analisis data spektrum NMR 1D (1H-NMR dan13C-NMR), NMR 2D (NOESY, TOCSY, HSQC, dan HMBC), dan spektrum massa (MS). Berdasarkan metodologi tersebut, dua senyawa turunan flavon yaitu 5,7,4’-trihidroksi-3’(3-metilbut-2-enil)-3-metoksiflavon (1) dan makarangin (2), telah berhasil diisolasi dari tumbuhan ini. Berdasarkan hasil penelitian tersebut menunjukan daun M. involucrata (Roxb.) Baill yang berasal dari Kabupaten Buton Tengah, Sulawesi Tenggara menghasilkan senyawa fenolik turunan flavonoid. Kata kunci: Euphorbiaceae, Macaranga involucrata (Roxb.) Baill, flavon. Macaranga is one of the largest genera of the family Euphorbiaceae comprising 300 species with local name “mahang-mahangan”. Macaranga is widespread in the region of Africa and the west of Madagascar to the tropical regions of Asia, northern Australia, and the Pacific islands. In Indonesia Macaranga spread in several areas: Papua, Maluku, Sulawesi, Kalimantan, Sumatra, Bangka, and Java. Phytochemical studies showed the presence of several phenolic compounds such as flavonoids and stilbene derivatives. The phenolic compounds have a unique molecular structure with the addition of some substituents such as prenyl (C5), geranyl (C10), farnesyl (C15), and geranylgeranyl (C20). This research has been conducted on the isolation of secondary metabolites from the leaves of M. involucrata (Roxb.) Baill by maceration method using acetone, followed by separation and purification by using liquid vacuum chromatography and radial chromatography to obtain pure compounds. Determination of the structure is based on data analysis of 1D NMR spectrum (1H-NMR and 13C-NMR), 2D NMR (1H-1HCOSY, NOESY, TOCSY, HSQC, and HMBC), and mass spectra (MS). Based on this methodology, two flavone derivatives 5,7,4\u27-trihydroxy-3\u27(3-methylbut-2-enyl)-3-methoxy flavone (1) and macarangin (2), have been isolated from this plant. Based on these results showed that leaf of M. involucrata (Roxb.) Baill from Central Buton, Southeast Sulawesi produces phenolic compounds from flavonoid derivatives. Keywords: Euphorbiaceae, Macaranga involucrata (Roxb.) Baill, flavone
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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