1,720,959 research outputs found
OPTIMASI PRODUKSI XILANASE OLEH B.subtilis AQ1 MENGGUNAKAN RESPONSE SURFACE METHODOLOGY
No full textXylanase is an important enzyme for xylan degradation into xylan derivative compounds such as xylose, xylobiose, xylotriose and other oligoxylan. Xylan derivatives can be bioconverted into bioenergy (ethanol), food ingredients as well as pharmaceutical or nutraceutical goods. Some bacteria have been reported to produce xylanases using defferent kinds of agricultural wastes as a substrate. The objective of this experiment was to optimize the concentration of corn cobs as a carbon source and liquid tofu waste as nitrogen source on xylanase production by Bacillus subtilis AQ-1. A 22 central composite experimental design was performed to optimize the corn cobs and liquid tofu waste concentration. A second order quadratic model and a response surface method showed that the optimum condition for xylanase production was 1.1 % (w/v) corn cobs and 0.00198 % (v/v) total N of liquid tofu waste with the highest xylanase production of 122.99 U/ml.Key words: bacillus subtilis AQ-1, xylanase, corn cob, liquid tofu wast
Phytochemical Screening and Larvicidal Activity of Fermented Garlic to Aedes aegypti and Aedes albopictus (Diptera: Culicidae)
No full textThe purpose of this study was to determine the effect of larvicidal compounds from garlic fermented on Aedes aegypti and Aedes albopictus as a vector dengue fever (DF) and dengue hemorrhagic fever (DHF) then compare the mortality and identifying active compounds of fermented garlic extract. The third instar larvae of Aedes aegypti and Aedes albopictus is used in this research. It fermented garlic using fungi tempeh for 96 hours. Fermented garlic extracted by using centrifuges at 3500 rpm for 15 minutes and directly used to test larvicides. Larvicidal activity test was carried out with the bioassay test against mosquito third instar larvae with 11 different treatment groups, positive control (abate), negative control, 27.5%, 25%, 22.5%, 20%, 17.5%, 15% , 12.5%, 10% and 7.5%, and each treatment carried out four replications. Larvicidal activity is determined by calculating the percent of mortality for 24 hours to obtain the LC50 value. Phytochemical screening is done with standard procedures and the organophosphorus fraction of ethyl acetate fermented garlic extract using GC-MS. The percentages of larval mortality is 15-85% of Aedes aegypti and Aedes albopictus from 2.5 to 72.5%. LC 50 value for the larvae of A. aegypty lower (20%) than the larvae of A. albopictus (21.429%). Therefore, fermented garlic extract has potential as larvicides. Alkaloids, flavonoids, saponins, polyphenols, and steroids on garlic fermented extract are not identified. 49 organophosphorus compounds are identified and allicin derivative compounds on fermented garlic are the allyl-2,3-Epoxypropyl sulfid
PENERAPAN MODEL PEMBELAJARAN KOOPERATIF TIPE THINK PAIR SQUARE TERHADAP HASIL BELAJAR SISWA MATERI STRUKTUR DAN FUNGSI JARINGAN TUMBUHAN PADA KELAS VIII SMP NEGERI 1 BATUSANGKAR
No full textPenelitian ini bertujuan untuk membandingkan hasil belajar siswa yang menerapkan model pembelajaran kooperatif tipe Think Pair Square dengan hasil belajar siswa yang menerapkan model pembelajaran konvensional materi struktur dan fungsi jaringan tumbuhan kelas VIII di SMP Negeri 1 Batusangkar. Jenis penelitian yang peneliti gunakan adalah eksperimen semu. Desain eksperimen yang digunakan dalam penelitian ini adalah Randomized Posttest Controul Group Only Design. Populasi dalam penelitian ini adalah seluruh siswa kelas VIII SMP Negeri 1 Batusangkar tahun ajaran 2017/2018 yang terdiri dari sembilan kelas. Sampel dalam┬á penelitian ini adalah siswa kelas VIII.8 sebagai kelas eksperimen dan VIII.9 sebagai kelas kontrol. Data hasil belajar siswa diperoleh dari hasil tes kedua kelas sampel setelah penerapan model pembelajaran kooperatif tipe Think┬á Pair Square pada kelas eksperimen dan model pembelajaran konvensional pada kelas kontrol. Hipotesis diuji dengan menggunakan uji-t. Hasil penelitian menujukkan rata-rata hasil belajar siswa pada kelas eksperimen adalah 84,81 sedangkan pada kelas kontrol adalah 77,00. Dari uji hipotesis diperoleh ┬ádimana┬ásehingga hipotesis nol ditolak. Dapat disimpulkan bahwa, ÔÇ£Hasil belajar siswa dengan menerapkan model pembelajaran kooperatif tipe Think Pair Square lebih baik dari hasil belajar siswa dengan menerapkan model pembelajaran konvensional pada materi Struktur dan Fungsi Jaringan Tumbuhan kelas VIII SMP Negeri 1 BatusangkarÔÇØ
Pengembangan E-Modul Biologi Berbasis Kvisoft Flipbook Maker Pada Materi Klasifikasi Makhluk Hidup Kelas VII SMP Islam Raudhatul Jannah Payakumbuh
No full textThis research is motivated by the low ability of students to understand learning material even though at Raudatul Jannah Islamic Junior High School has used quite good technology which can be proven by the opening of digital classes, where students every day bring laptops and supporting facilities such as wifi, air conditioning, infocus, and comfortable classroom. With such facilities, the learning process should be more effective than other classes. However, what is found in the field is that students still do not understand learning. This can be seen from the learning outcomes of students who apply the digital learning process to the classification of living things in class VII.6 of Raudhatul Jannah Islamic Junior High School. Student learning outcomes show that cognitive abilities are still relatively low. Where the percentage of students' completeness is below 50%. The learning media used by the teacher are only in the form of power points, videos and textbooks without any new innovations so that students are less motivated to learn. Based on the above background, the author conducted a study to find a solution to this problem, namely by developing a Biology E-Module Based on Kvisoft Flipbook Maker on Classification of Living Creatures Class VII Islamic Junior High School Raudhatul Jannah Payakumbuh. This research is a development research using a 4-D development model. The development stage using the 4-D model has four stages, namely the definition stage, the design stage, the development stage, and the dissemination stage. However, in this study, the authors carried out to the development stage (develop). The instrument used in this study was a validation test sheet. Data analysis used descriptive analysis.Based on the research that has been done, a product is produced in the form of a Kvisoft FlipbookMaker-Based Learning E-Module. The E-Modul validation results obtained an average value of 85.69% which is categorized as very valid from the aspects of Guides and Information, Multimedia Content or Materials, Evaluation, Program Performance, Systematics and Aesthetics . And the Kvisoft FlipbookMaker Based Learning Module can already be used for learnin
Pengembangan E-Majalah Bernuansa Al-QurÔÇÖan Pada Materi Sistem Tubuh Pada Pembelajaran Biologi Untuk MTsN Kelas VIII Semester 2
No full textThe purpose of this research is to develop an E-Majalah with Al-Qur'an nuances on the Body System Material in Biology Learning for Valid MTsN Class VIII MTsN Semester 2. The results of the validation analysis obtained by the Al-Qur'an Nuanced E-Majalah were measured from the average validity with the results of 83% in the very valid category. Based on the results of the research that has been carried out, it can be concluded that the E-Majalah Biology with Al-Qur'an nuances on the body system material developed is suitable for use in the learning process of Biology at MTsN/SMP class VIII on body system material (Excretion System, Movement System, Respiratory System, Circulatory System and Digestive System). This can be seen from the validation aspect with an average validity value of 83% with very valid criteria
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
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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