55 research outputs found
Potential of Lignosulphonate of Eucalyptus Lignin from Pulp Plant as Dispersant in Gypsum Paste
AbstractEucalyptus lignin was isolated from kraft black liquor through acidification by using H2SO4. To effectively utilize black liquor waste from pulp plant, lignin was converted into sulphonated hydroxymethylated phenolized sulphuric acid lignin compound (SHP-SAL), which is soluble in water. SHP-SAL was obtained through the sequence of (1) phenolation of sulphuric acid lignin (SAL) into phenolized sulphuric acid lignin (P-SAL), (2) hydroxymethylation of P-SAL into hydroxymethylated phenolized sulphuric acid lignin (HP-SAL), and (3) sulphonation of HP-SAL into SHP-SAL. The derived lignin of SHP-SAL characterized by infrared spectrometry showed a significant absorption at 630 cm-1, which indicates the presence of S−O bond, and absorption at 1118 and 1059 cm-1, which are characteristics of C−O bonds in lignosulphonates. Assessment of SHP-SAL as a dispersant in gypsum paste was done according to C230-90 ASTM standard. The synthesized SHP-SAL has approximately 60% higher dispersability than those of commercial sodium lignosulphonate (comm. SLS) and commercial calcium lignosulphonate (comm. CLS). It is equal to the dispersability of sulphonated naphthalene formaldehyde (SNF), one of the high-performing sulphonate compounds
Penerapan Model Pembelajaran Kooperatif Tipe Teams Games Tournament (Tgt) Untuk Meningkatkan Minat Dan Hasil Belajar IPA Pada Siswa Kelas Viib4 Di Mts Darul Hikmah Pekabaru
The purpose of this research is to increase the interest and learning outcomes VIIb4 grade science students MTs Darul Hikmah Pekanbaru after the implementation of cooperative learning model type Teams Games Tournament (TGT). This study was conducted in April-May 2016. This study is a Class Action Research (CAR) conducted in two siklus.Subjek were students in grade VIIb4 by the number of students 24 orang.Parameter of this study are of interest, learning outcomes (absorption and Mastery learning), awards groups, student activities and activity guru.Hasil research found the average student interest before the implementation of cooperative learning model TGT is 1.80 (Low), increased after the first cycle that 2:03 (Medium), and increased after the second cycle ie 3:26 (High) .Rata average dayaserap students padasiklus I amounted to 78.75% (Enough), meninkat padasiklus II became 85.00% with a (Good). Ketuntasanbelajarindividupadasiklus I is 75.00% category, please, padasiklus II became 87.50% dengankategori Baik.Penghargaan group of the second cycle of the four groups awarded with Great category, the second cycle groups one group was awarded the Super category and three groups received awards by category Hebat.Rata -rata activity of students in the first cycle is 66.55% (Less), padasiklus II is 76.90% with (Enough) .Rata average teacher activity padasiklus I and II cycle of 100% dengankategoriSangat Good. Based on research that has been done, Model Cooperative Learning Teams Games Tournament (TGT) in science teaching can improve learning outcomes siswakelas interest and VIIb4 MTs Darul Hikmah Pekanbaru
Penerapan Model Pembelajaran Kooperatif Tipe Student Teams Achievement Division (Stad) Untuk Meningkatkan Hasil Belajar IPA Siswa Kelas X (Akuntansi) Smk Rokan Bagan Siapiapi Tahun Ajaran 2015/2016
Based on the results of interviews and observations that have been implemented by researchers teachers rarely use model cooperative learning, student learning outcomes and low it can be known from the students who completely individually on the KKM 75 IE 67,64%. Therefore carried out the renovation of the learning by applying cooperative learning to improve the learning outcomes of students in SMK ROKAN Bagansiapiapi. One type of cooperative learning, i.e. Student Teams Achievement Division (STAD). This research was conducted in class X SCIENCE (accounting) SMK Rokan Bagansiapiapi the academic year 2015/2016 to know improvements learn IPA students by applying cooperative learning model type STAD. This research is a research action class is done in two cycles, which consists of planning, implementation, observation and reflection. The data collected in this study is the student learning which consists of absorption, learning, student activities and teacher activities. The data collected using the test and the observation sheet. Absorption based on the value of the post test on cycle I rise on post test 1 is 71.14% (less) become 97.40% (very good) on the post test 2 and in cycle II, the average post test 1 94.53 (very good) became 96.36 (very good) on the post test 2. student learning based on Deuteronomy I cycle daily i.e. 72.12% (less) and cycle II increased to 82.12% (good). Group Award at the cycle I, 2 groups and 2 super group the predicate predicate excellent and good Group 2. In cycle II, all predicate good. Learning activities of students at the time of discussing with the application of cooperative learning model type STAD cycle 1 rise in cycle I, namely 67.87% (less) increased to 82.12% (good) in cycle II. The activity of the teacher in the process of teaching and learning on a cycle I was 87,83%, (good) and cycle II is 95.83% (very good). It can be concluded that the application of the model of the pembelaaran cooperative type STAD can improve the learning results of IPA students class X SCIENCE (accounting) years 2016 2015/Lessons
Struktur Dan Komponen Arang Serta Arang Aktif Tempurung Kemiri
Cara aktivasi arang menentukan kekhususan penggunaan arang aktif yang dihasilkan. Secara umum dikenal dua cara aktivasi arang untuk menghasilkan arang aktif yaitu cara fisika dan kimia. Penelitian ini bertujuan untuk mengetahui struktur dan komponen penyusun arang dan arang aktif tempurung kemiri. Tempurung kemiri dikarbonisasi menggunakan tungku drum untuk menghasilkan arang, selanjutnya arang diaktivasi di dalam retort listrik menggunakan aktivator panas selama 120 menit pada suhu 550C, 650C, dan 750C dan aktivator uap air selama 90 dan 120 menit pada suhu 750C. Sampel uji tempurung kemiri, arang dan arang aktif dikarakterisasi strukturnya yang meliputi gugus fungsi, kristalinitas dan porositas dengan menggunakan Fourier Transform Infra Red (FTIR), X-Ray Difractometer (XRD) dan Scanning Electron Microscope (SEM). Selain itu, senyawa kimia masing-masing sampel uji diidentifikasi menggunakan Pyrolisis Gas Chromatograph Mass Spectrometer (Py-GCMS) Hasil mengindikasikan bahwa proses aktivasi menyebabkan terjadinya Perubahan pola gugus fungsi, peningkatan kristalinitas, pembukaan pori dan reduksi senyawa kimia. Semakin tinggi suhu aktivasi diikuti oleh peningkatan kristalinitas, diameter pori dan reduksi senyawa kimia arang aktif. Aktivasi menggunakan uap air menghasilkan arang aktif dengan pori yang relatif lebih bersih
Biological Activities Afforded by the Extract From Raru Bark to Inhibit Action of Alpha- Glucosidase Enzymes
Raru (Shoreabalanocarpoides Sym) signifies one of the tree species that grows widespread in Sumatra Island. Its bark portion is commonly used by local villagers as additional ingredient mixed to nira (sugar palm juice). This addition is intended to make the juice more durable and also to enrich its taste after the juice is previously fermented to become traditional toddy beverage or the so-call “tuak”. Local villagers believe that raru bark can reduce the level of blood sugar. As the relevance, the research was conducted to confirm that the extract from raru bark could afford its biological activities to inhibit alpha-glucosidase enzyme through its characterization, quantification, and isolation of its boactive compound. The extraction was performed using two methods (i.e.reflux and maceration techniques). Result revealed that the bark extract obtained from both techniques contained polyphenol compounds: flavonoid, saponin and tannin. Further, raru-bark extract from the reflux and maceration techniques could inhibit the action of alpha glucosidase enzymes on carbohydrate substrate ( i.e. p -nitrophenil-α-D-glucopyranose), at respectively 90.67% and 97.33%. Meanwhile, the inhibition activities afforded by the patented drug as a control (i.e. glucobay) equaled to 97.05%. Assesment using UV-VIS spectroscopy, showed that the maximum spectrum of bioactive compound in the extract was at the wave length of 288.6 nm. Scrutiny using FTIR spectroscopy could identif y the presence of aromatic groups in the compound, containing -OH, C-H, C=C, C-O and C-H bond types. Analysis using GC-MS exhibited that the compound had molecular weight of 390 with molecular structure as C20H22O8. Ultimately, data analysis scrutiny with the aid of NMR judged the most plausible compound as bioactive was 4-Glucosyl-3, 4', 5-trihydroxystilbene
Penerapan Model Pembelajaran Berbasis Proyek untuk Meningkatkan Keterampilan Berpikir Kritis dan Hasil Belajar Biologi Siswa Kelas XI IPA 5 Sman1 Bangko Tahun Ajaran 2014/2015 Nurul Addha*,
The purpose of this study was to determine the application of project-based learning model to increase critical thinking skills and student learning outcomes in teaching Biology XI IPA SMAN 5 1 Bangko School Year 2014/2015. This study was conducted in April-May 2015. This study is a Classroom Action Research (CAR) conducted in two cycles. The subjects were students of class XI IPA 5 the number of students 30 people. Parameters of this research is of critical thinking skills, learning outcomes (Absorption and Mastery learning), project performance and product skills, attitudes. The result showed the average critical thinking skills first cycle 51% with medium category, the second cycle is 71.99% with the High category. The average absorption of students in the first cycle of 64.2% with good category, on the second cycle becomes 75.6% with good category. Mastery learning of individuals in the first cycle of 36.67% Less categories, on the second cycle into 56.67% to the category of Self. On average skills of students in the performance of the project in the first cycle is 65.7% with good category, the second cycle is 83.8% with good category. On average skills of students in the performance of the product in the first cycle is 79.14% with good category, the second cycle is 79.15% with the good category. On average attitude of learners in the first cycle is 76.24% with good category, the second cycle is 82.93% with the good category. Based on the research that has been done, the Project Based Learning model of teaching biology to improve learning outcomes and the critical thinking skills of students of class XI IPA SMAN 5 1 Bangko School Year 2014/2015
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