Siti Bariroh
Program Studi Teknik Kimia, Fakultas Teknik, Universitas Negeri Semarang

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PENGOLAHAN BIJI MAHONI (Swietenia Macrophylla King) SEBAGAI BAHAN BAKU ALTERNATIF BIODIESEL Damayanti, Astrilia; Bariroh, Siti
Jurnal Bahan Alam Terbarukan Vol 1, No 1 (2012): June 2012
Publisher : Semarang State University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15294/jbat.v1i1.2539

Abstract

Peningkatan kebutuhan minyak bumi yang terus menerus akan mengakibatkan kelangkaan bahan bakar minyak. Sumber energi alternatif yang ramah lingkungan, salah satunya adalah biodiesel. Bahan baku potensial untuk memproduksi biodiesel yang tidak bersaing dengan bahan baku pangan contohnya adalah biji mahoni (swietenia macrophylla king). Tahapan yang diperlukan dalam percobaan biodiesel adalah proses pengambilan minyak biji mahoni dengan proses penyangraian, degumming, dan proses transesterifikasi. Alat yang diperlukan dalam pembuatan biodiesel yaitu: labu alas bulat dilengkapi kondensor, gelas ukur, pengaduk magnetik, alat-alat gelas lab, dan lain sebagainya. Proses pengambilan minyak dilakukan dengan penyangraian yang hasilnya di degumming dengan asam fosfat 5% b/b pada suhu 80ºC selama 15 menit. Degumming bertujuan untuk menghilangkan getah, lendir, protein, resin dan gum. Proses kedua yaitu transesterifikasi dengan metanol 1:6 (minyak dan mtanol) dengan KOH 0,1 N pada suhu 60ºC selama 1 jam. Setelah diperoleh metil ester, dilakukan proses pencucian atau penetralan metil ester pada suhu pemanasan 104ºC untuk menghilangkan kadar airnya. Dari hasil percobaan diperoleh rendemen minyak sebesar 86,92%, uji densitas 874,08 kg/m³, viskositas 3,07 mm2/s, dan bilangan asam 0,5601 mg KOH/g. Metil ester yang dihasilkan telah sesuai dengan SNI-04-7182-2006. An increased demand of the fossil fuel would lead to scarcity of the fossil fuel in the future. An alternative of environmentally friendly energy sources is biodiesel. It is accounted that the resources for producing biodiesel should not compete with food raw materials, such as mahogany grain, (swietenia macrophylla king). The necessary steps in the experiment of producing biodiesel are process of taking the mahogany seed-oil by using roasting method, degumming, and transesterification process. The required equipments for producing biodiesel were round-bottom flask equipped with condenser, measuring cylinder, magnetic stirrer, other lab-glassware, etc. Firstly, the process of taking the oil from mahogany seed was carried by using roasting method; then the result was degummed by using 5wt% of Phosphate acid at 80 oC for 15 minutes. The degumming process was aimed to remove sap, mucus, proteins, resin and gum. The second step was transesterification process using methanol 1:6 (oil and methanol) and 0.1N KOH solutions, which was carried out at 60 oC for 1 hour. Once the methyl ester was produced, the next steps were washing and neutralization of methyl ester at heating temperature of 104 oC to remove the water content in the methyl ester. The obtained yield from the experiments was 86.92%. The tested density, viscosity, and the acid value were 874.08 kg/m³, 3.07 mm2/s, and 0.5601 mg KOH/g, respectively. The produced Methyl ester is in accordance with SNI-04-7182-2006.
ANALISIS PENGARUH KEDISIPLINAN KERJA GURU TERHADAP PRESTASI BELAJAR SISWA PADA SMA NEGERI 1 BUMIAYU KABUPATEN BREBES Bariroh, Siti
Jurnal Kependidikan Vol 3 No 2 (2015)
Publisher : Kelompok Kajian Pendidikan Ikatan Alumni IAIN Purwokerto

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (287.488 KB) | DOI: 10.24090/jk.v3i2.898

Abstract

Discipline is one of the factors of success in achieving learning goals. Discipline teacher will bring a positive impact on the development of students, it requires dedication and a high responsibility. A teacher required to cultivate the mindset, have extensive knowledge, must also have competencies that qualified, good pedagogy, methodology, or disciplines to be taught. The teaching profession is a noble profession, although sometimes underestimated, but it is crucial in preparing the next generation, which will continue nation's leadership in the future. Teachers are also required to be able to provide examples of good models, in order to produce generations that can be better in the future. xThe benchmark of whether good nor bad of one community is the education itself. While the main character in the world of education is the teacher, because the teacher are able to single handedly carve a student's future whether it's good nor bad.The people's expectation on the products of the education system can be seen on the student's both academic and non-academic achievements.This research is using a quantitative descriptive method, whereas the type of approach used in this study is a partial correlation by analyzing the relationship (influence) between the variables of work discipline in the teacher with student achievement.Data collection technique is to spread the Likert scale questionnaire form which contains a number of questions about the indicators of work discipline and student achievement. The data obtained was then added to the partial correlation formula per variable, then connected, whether there is a significant relationship between teacher's work discipline with student achievement in SMA Negeri 1 Bumiayu, Brebes Regency, while the author used determinant coefficient to analyze the relationship between teacher's work discipline and student achievement.The results of the study is showing that teacher's work discipline will affect student achievement, because there is a relationship of 0.786 or 78.6% that were classified as very strong based on the level of its relationship.
HUBUNGAN ANTARA KETERAMPILAN HITUNG, KEMANDIRIAN BELAJAR DAN LINGKUNGAN BELAJAR DENGAN PRESTASI BELAJAR MATEMATIKA Bariroh, Siti
UNION: Jurnal Ilmiah Pendidikan Matematika Vol 5, No 1 (2017)
Publisher : Universitas Sarjanawiyata Tamansiswa Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (512.43 KB)

Abstract

descriptively, the purpose of this study is to know the tendency students’ of computational skills, independece of  learning, learning environment and the academic mathematics achievement of the students class VIII SMP Negeri of  in Panjatan district on 2013/2014 academic year. Correlatively, the purpose is to determine the relationship between computational skills, independece of  learning,  learning environment and the academic mathematics achievement of the students class VIII SMP Negeri of  in Panjatan district on 2013/2014 academic year. The population of this study was all students of VIII SMP Negeriin Panjatan district on 2013/2014 academic year. Sampling is taken by using cluster randomsampling technique.. The researcher took and selected class of  VIII B and VIII C SMP N I Panjatan and class VIII A and VIII B SMP N 2 Panjatan as the sample class with the number of responders is 108 students. The data analysis is using multiple correlation and multiple regression of two variables. The results of this descriptive study showed that the computational skills is in a very high category, while their independece of  learning is in the high category, while their the  learning environment is in the high category and their learning mathematics achievement in a high category.From the calculation of multiple correlation test, the value ofR=0,647 by p= 0,000 <α=0,05, it means that there is a positive and significant relationship between computational skills, independece of  learning,  learning environment and the academicmathematics achievement.
STUDI KEMAMPUAN MEMBACA SECARA KOMPREHENSIF DENGAN “SUMMARIZE DAN REWRITE THE TEXT” Muharlisiani, Lusy Tunik; Bariroh, Siti; Etiyasningsih, Etiyasningsih; Sundari, Sri; Andrijanti, Andrijanti; Susetyorini, Susetyorini; Elan, Umi; Kusumaningrum, Dini; Farida, Nur; Rahayu, Dwi Inggarwati
PROSIDING SEMINAR NASIONAL CENDEKIAWAN PROSIDING SEMINAR NASIONAL CENDEKIAWAN 2019 BUKU II
Publisher : Lembaga Penelitian Universitas Trisakti

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25105/semnas.v0i0.5877

Abstract

Pembelajaran membaca secara komprehensif dituntut untuk mengasah kreativitas memahami dan mengambil kesimpulan sesuai gambaran mereka masing-masing. Dengan merangkum dan menulis kembali apa yang telah mereka baca maka dapat mempermudah proses pemahaman dan menjadi informasi bagi pengajar untuk lebih mengenal siswa melalui hasil kerja siswa. Tujuannya adalah membahas proses pembelajaran secara optimal dan dapat memahami apa yang mereka baca secara komprehensif. Metode yang digunakan merangkum dan menulis kembali sebuah bacaan yang telah dibaca sesuai dengan pemahaman yang dimiliki siswa. Analisa data: a. Guru tidak harus menyalahkan hasil rangkuman siswa, karena itu merupakan hasil pemahaman mereka dan setiap siswa memiliki tingkat pemahaman yang berbeda, b. Guru sebaiknya hanya memberikan pembetulan kepada siswa tentang bagaimana cara memilih bahasa yang tepat atau membetulkan struktur teks yang ditulis oleh siswa. Hasilnya adalah pada pembelajaran membaca secara komprehensif siswa diharap memiliki konsentrasi yang maksimal agar dapat fokus pada bacaan agar hasil rangkuman yang mereka buat sesuai dengan yang mereka pahami. Kesimpulannya diharapkan siswa dapat terus mengembangkan kemampuan membaca secara komprehensif untuk mengasah otak dan kemampuan untuk memahami makna sebuah teks yang mana dapat juga diartikan sebagai kemampuan kreativitas mereka dalam memaknai sebuah bacaan tertentu.