Dwi Septiani
Jurusan Kimia FMIPA Universitas Negeri Semarang Gedung D6 Lantai 2 Kampus Sekaran Gunungpati Semarang, 50229, Telp. (024)8508035

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PENINGKATAN EFISIENSI KOMPOR GAS DENGAN PENGHEMAT BAHAN BAKAR ELEKTROLIZER

ROTASI Vol 17, No 1 (2015): VOLUME 17, NOMOR 1, JANUARI 2015
Publisher : Jurusan Teknik Mesin, Fakultas Teknik, Universitas Diponegoro

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Abstract

Beberapa metode penghemat bahan bakar pada kompor gas  telah dibuat dan diuji cobakan salah satunya adalah  penggunaan penghemat bahan bakar elektrolizer. Prinsip alat ini adalah proses elektrolisis dengan dua elektroda yang dimasukkan didalam larutan elektrolit (campuran air-NaOH). Dengan dialiri arus listrik DC pada dua elektrode,  akan timbul gas HHO (gas Brown)  yang bersama-sama dengan gas LPG dapat meningkatkan proses pembakaran dalam kompor gas. Dengan memvariasikan konsentrasi NAOH dalam larutan maka akan terjadi perubahan efisiensi pembakaran. Dalam pengujian dihasilkan bahwa pada kosentrasi NAOH 33 % dan arus DC 1.7 Ampere, diperoleh peningkatan efisiensi pembakaran tertinggi, yaitu didapat penghematan gas LPG hingga 19 %.

STUDI MAGNETISASI PADA SISTEM SPIN MENGGUNAKAN MODEL ISING 2D

Jurnal Spektra Vol 12, No 2 (2011): Spektra: Jurnal Fisika dan Aplikasinya
Publisher : Jurnal Spektra

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Abstract

Simulasi pada system spin 2D telah disimulasikan menggunakan model Ising untuk mempelajari karakteristik magnetisasi. Studi magnetisasi ini diamati hanya berdasarkan pada medan magnet internal yang disebabkan oleh pergerakan spin. Model ini dideskripsikan sebagai sistem spin dengan variasi panjang kisi (L) yang dimulai dari 50 au sampai 250 au dengan kenaikan 50 au. Hasil menunjukkan ukuran kisi-kisinya adalah 50, 100, 150, 200, dan 250 au dengan puncak maksimum lokasi magnetisasi yang paling intense masing-masing pada 0.0153, 0.00787, 0.0056, 0.0040, dan 0.0032 A/m. Namun, suhu kritis (T/T0)C  bervariasi yaitu 38.44, 36.28, 35.37, 27.84, dan 21.38 K sesuai dengan bertambahnya L. Hasil ini menunjukkan bahwa magnetisasi bergantung pada konfigurasi spin dan ukuran kisi. Sedangkan, suhu kritis yang teramati pada grafik magnetiasasi bervariasi dengan bertambahnya ukuran kisi.  Kata kunci: Magnetisasi, Sistem Spin, Ising 2D, Ukuran Kisi, Temperature Kritis

EFEKTIVITAS MODEL INKUIRI BERBANTUAN MODUL DALAM MENINGKATKAN PEMAHAMAN KONSEP DAN KETERAMPILAN GENERIK SAINS

Jurnal Inovasi Pendidikan Kimia Vol 8, No 2 (2014): July 2014
Publisher : Jurusan Kimia, Fakultas Matematika dan Ilmu Pengetahuan Alam, Universitas Negeri Semarang

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Abstract

Student-centered learning paradigm requires teachers to reduce the dominance of the teacher in the learning activities so students can optimally develop their potentials, such as generic science skills. This study aims to determine the effectiveness of the application of the Inquiry Based Learning (IBL) assisted module to an improved concepts understanding and generic skills of students of senior high school in Ngawen in the buffer material and salt hydrolysis. The population was all students in class XI IPA of that senior high school in 2012/2013 academic year. The research design is a pretest and posttest group design. Sampling technique used is cluster random sampling, derived class XI IPA 1 as experimental class and class XI IPA 2 as the control class. The results showed that the average posttest’s score of concept understanding of experimental class 84,00 and control class 77.52. In the experimental class obtained the clasical completeness 97% and control class 83%. The result of first and second lab observation obtained the average score of generic science skill at the experimantal class were 83,43 and 93,51 while the control class were 81.41 and 91.59. Based on the results of this study, it can be  concluded that implementation of the IBL model through  module was effective in improving the understanding of science concepts and generic skills of students.Keywords: Generic Science Skills, Inquiry Guided Module

PENGEMBANGAN LEMBAR KERJA SISWA BERBASIS MULTIPLE INTELLIGENCES PADA MATERI PERTUMBUHAN DAN PERKEMBANGAN

Journal of Biology Education Vol 2 No 3 (2013)
Publisher : Journal of Biology Education

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Abstract

This study aimed to develop and assess feasibility of student worksheet on Growth and Development topics, based on multiple intelligences theory, as well as to measure the effectiveness of  the student worksheet. Research design used  was one of research and development modified from Sugiyono (2010), and was based on students’ intelligences identification and teaching materials analyzed. LKS validation results were analyzed with descriptive percentages. Small-scale testing was  carried out on 1 teacher and 12 students to assess worksheets legibility. Large-scale field-testing was carried out on one teacher and 36 students to measure student worksheets’ effectiveness. Results of student worksheet development based on multiple intelligences theory in terms of  its material feasibility aspects was  96,87% (obtained score) and media feasibility 89,56% under medium category. Normalized gain score was 0,65, indicating that  there was an increasing learning achievement  from pretest to posttest under medium category. Classical completeness of  students reached 88,89%. The use of  the student worksheet for  learning process was appreciated ‘ very good responses’ by  teachers and students, 100% and 88,69%. Student worksheet development  on the basis of multiple intelligence theories for  Growth and Development topics was  feasible and effectively applied for  learning. Penelitian bertujuan untuk mengembangkan dan mengetahui kelayakan Lembar Kerja Siswa (LKS) berbasis multiple intelligences pada materi pertumbuhan dan perkembangan serta mengukur keefektifan LKS dalam pembelajaran. Penelitian menggunakan metode penelitian pengembangan (Research and Development) dimodifikasi dari Sugiyono (2010) berdasarkan hasil identifikasi kecerdasan siswa dan analisis kebutuhan bahan ajar. Hasil validasi LKS dianalisis dengan deskriptif persentase. Uji coba skala kecil dilakukan terhadap 1 guru dan 12 siswa untuk menilai keterbacaan LKS. Uji coba skala besar dilakukan terhadap 1 guru dan 36 siswa untuk mengukur efektivitas LKS dalam pembelajaran. Hasil pengembangan LKS berbasis multiple intelligences aspek kelayakan materi memperoleh skor 96,87% dan kelayakan media 89,56% dengan kategori sangat layak. Nilai gain ternormalisasi sebesar 0,65 menunjukkan adanya peningkatan hasil belajar dari pretest ke posttest dengan kategori sedang. Ketuntasan klasikal siswa mencapai 88,89%. Penggunaan lembar kerja siswa dalam pembelajaran memperoleh tanggapan sangat baik dari guru dan siswa dengan persentase 100% dan 88,69%. Pengembangan lembar kerja siswa berbasis multiple intelligences pada materi pertumbuhan dan perkembangan layak dan efektif diterapkan dalam pembelajaran.

Influence of Learning Interest and Vocabulary on the Writing Description of Secondary School in Depok

HORTATORI Jurnal Pendidikan Bahasa dan Sastra Indonesia Vol 1, No 2 (2017): HORTATORI: Jurnal Pendidikan Bahasa dan Sastra Indonesia
Publisher : Pusat Studi Pendidikan Bahasa dan Sastra Indonesia Universitas Indraprasta PGRI

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Abstract

The purpose of this research: (1) to know the influence of the interaction of learning interest and mastery of the standard vocabulary together to the ability to write the description of the students of SMPN in Depok. (2) to know the effect on the ability to write the description of SMPN students in Depok. (3) to know the influence of standard vocabulary mastery to the ability to write the description of SMPN students in Depok. The research method used is survey method with multiple correlation regression analysis. The sample of the research is the students of class VII: SMPN 1 Depok and SMPN 2 Depok as many as 80 students and take a simple random technique. Data collection was done by direct questionnaire to sample. Data analysis uses descriptive statistics, such as searching for mean (mean), median, mode, standard deviation, and inferential statistics, ie to find simple and double correlation coefficients followed by correlation coefficient significance test with t test. The findings of the researcher indicate that: (1) there is a significant influence of learning interest and mastery of the standard vocabulary simultaneously to the ability to write student description with the acquisition value Fo= 21,909 and Sig.= 0,000 < 0.05; (2) there is a significant influence of learning interest on the ability to write student description with thitung (3,564) > t table (1,99) and Sig. 0.001 < 0.05; (3) there is a significant influence of vocabulary mastery of the learning achievement on the subject of writing description. This is evidenced by the value of thitung (5.909) > t table (1.99) and Sig. 0,000 < 0.05.

Pengaruh Sistem Pengendalian Intern Penggajian dan Sistem Informasi Akuntansi Penggajian terhadap Penggajian

JURNAL ILMIAH AKUNTANSI UNIVERSITAS PAMULANG Vol 4, No 2 (2016): JIAUP : JURNAL ILMIAH AKUNTANSI UNIVERSITAS PAMULANG
Publisher : S1 Accounting Program, Universitas Pamulang

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Abstract

Employee payroll system has been centralized means the payroll procedure is not set in the offices of their own area, but a distribution office that govern them. This research was conducted at PT. PLN (Persero) Distribution of Jakarta and Tangerang Area Bulungan. The data used is the employee payroll data from January 2012-December 2013. This study aims to determine the application and implementation of the internal control system of payroll and payroll accounting information system to the payroll at PT. PLN (Persero) Distribution of Jakarta and Tangerang Bulungan area, whether it has been carried out properly or not in practice. The method used is the method of observation and interview methods. The results showed partial correlation value between the internal control system of payroll and payroll accounting information system of the payroll amounted to 0,929 with the level of the relationship is very strong and partial correlation coefficients that t count 11.505> t table 2,080 which means there is a significant relationship between the internal control system of payroll and information systems payroll accounting to payroll at PT. PLN (Persero) Distribution of Jakarta and Tangerang Area Bulungan. And the results of multiple regression test of 9.9, which means when the internal control system of payroll and payroll accounting information system increased until an optimal (10), then the payroll to 9.9, then the hypothesis is Ha accepted conducted with simultaneous test done of F count 72> F table 3.47 which means there is influence between the internal control system of payroll and payroll accounting information system to the payroll at PT. PLN (Persero) Distribution of Jakarta and Tangerang Area Bulungan.

Pendidikan Karakter Siswa melalui Cerita Fantasi dalam Buku Bahasa Indonesia SMP/MTs Kelas VII Edisi Revisi 2017

Pena : Jurnal Pendidikan Bahasa dan Sastra Vol 8 No 1 (2018): Pena: Jurnal Pendidikan Bahasa dan Sastra
Publisher : Program Studi Pendidikan Bahasa dan Sastra FKIP Universitas Jambi

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Abstract

Karya sastra di sekolah dapat dijadikan sebagai salah satu sarana pembentukan dan penguatan pendidikan karakter siswa. Melalui materi cerita fantasi, pembelajaran bahasa dan sastra Indonesia pada tingkat SMP/MTs dapat berperan sebagai alat untuk membentuk dan menguatkan pendidikan karakter pada diri siswa. Oleh karena itu, berbagai penelitian tentang pembelajaran sastra di tingkat SMP/MTs, khususnya cerita fantasi yang dapat membentuk pendidikan karakter perlu dilakukan. Metode yang digunakan dalam penelitian ini adalah metode deskriptif kualitatif. Data primer dalam penelitian ini adalah dua cerita fantasi berjudul “Kekuatan Ekor Biru Nataga” karya Ugi Agustono  dan “Berlian Tiga Warna” oleh Fanisa Miftah Riani dalam buku siswa kelas SMP/MTs berjudul Bahasa Indonesia SMP/MTs Kelas VII Edisi Revisi. Melalui unsur tema dan amanat dalam dua cerita fantasi di atas, diharapkan siswa memiliki watak dan perilaku yang positif dalam berinteraksi antarmanusia serta rasa nasionalisme terhadap tanah air. Berdasarkan hasil penelitian, teridentifikasi bahwa unsur intrinsik, yakni tema dan amanat pada cerita fantasi dapat dijadikan sebagai sarana utama untuk pembentukan pendidikan karakter yang positif pada diri siswa