Articles
<![CDATA[PERUBAHAN SUDUT POLARISASI ALAMI DAN ELEKTROOPTIS MINYAK SAWIT YANG DICAMPUR BERBAGAI MINYAK HEWANI ]]>
<![CDATA[Idrus, Hadiyati]]>;
<![CDATA[Kaltsum, Ummi]]>;
<![CDATA[Firdausi, K. Sofjan]]>
<![CDATA[ Sainstek : Jurnal Sains dan Teknologi Vol 9, No 1 (2017) ]]>
Publisher : <![CDATA[IAIN Batusangkar ]]>
Show Abstract
|
Download Original
|
Original Source
|
Check in Google Scholar
|
Full PDF (146.314 KB)
|
DOI: 10.31958/js.v9i1.595
<![CDATA[Palm oil-based cooking oil is the most widely used cooking oil. Palm oil circulating in the market is often mixed with animal oil by culinary entrepreneurs with a view to produce a more tasty taste so it needs to be examined purity. Research on the content of saturated fatty acids using gas chromatography mass spectrophotometer (GCMS) requires quite expensive cost so that an alternative method is needed to determine the quality of cooking oil; especially its purity is by using polarization both naturally and by electrooptic method. This research uses incandescent lamp as light source. Samples flanked by parallel metal plates are placed between polarizers and analyzers. Samples of a mixture of palm oil with each animal oil (chicken oil, pork oil, cow oil). The samples of each oil are tested byu using natural polarization (active polarization) and electro-polarization polarization (impact polarization). The results showed that the polarization angle change in the oil of the mixture was greater than that of pure palm oil with the greatest angular change produced by a mixture of palm oil and cow oil (1.5 for natural polarization and 3 for electro-polarization). This result was in accordance with the result of the titration test shows that mixed oils have free fatty acids and PV peroxide numbers higher than pure palm oil. The cow's oil mix is the greatest change compared to pigs and chickens. This result shows that cow's oil has the highest saturated fatty acid content. Electrooptical polarization angle larger than natural polarization. This is due to the interaction of the electric field of the light source with the electric field of the molecule induced by the electric field of the power supply. The polarization method successfully distinguishes the type of pure and mixed cooking oil.]]>
<![CDATA[PENGARUH PENAMBAHAN MINYAK GORENG HEWANI PADA MINYAK SAWIT TERHADAP PERUBAHAN SUDUT POLARISASI ]]>
<![CDATA[Kaltsum, Ummi]]>;
<![CDATA[Idrus, Hadiyati]]>;
<![CDATA[Firdausi, K. Sofjan]]>
<![CDATA[ BERKALA FISIKA 2014: Berkala Fisika Vol. 17 No. 3 Tahun 2014 ]]>
Publisher : <![CDATA[BERKALA FISIKA ]]>
Show Abstract
|
Download Original
|
Original Source
|
Check in Google Scholar
|
Full PDF (189.79 KB)
<![CDATA[The use of animal oil for various purposes by the people has inspired this study. The purpose of the study was to distinguish the mixture of cooking oil palm and variety of animal oil (chicken oil, beef oil, and pork oil). The composition of the mixture of palm oil and animal oil is 3:1 mL, respectively. The light source used were He-Ne laser of 1 mW (λ = 633 nm) and IR lamp of 250 watt (λ = 750-800 nm). Measurements were made based on changes in the natural polarization angle (0 kV) and electrooptics (6 kV). The result showed that the natural polarization angle changes and electrooptics of mixture of palm oil and animal oil greater than pure palm oil, both at He-Ne laser and IR light. This is consistent with the results of the titration test, peroxide value and free fatty acids (FFA) oil mixture was greater than pure palm oil. Change in the polarization angle represents the presence of saturated fatty acids. Animal oils have saturated fatty acid content greater than palm oil, so the polarization angle changes of oil mixture is greater than polarization angle changes of pure palm oil. Keywords: animal frying oil, palm oil, polarization angle]]>
<![CDATA[PENGUJIAN SIFAT FOTOKATALIS LAPISAN TIPIS TIO2 PADA PRODUK DEGRADASI JELANTAH MENGGUNAKAN ELEKTROOPTIS ]]>
<![CDATA[Kaltsum, Ummi]]>;
<![CDATA[Kurniawan, Affandi Faisal]]>;
<![CDATA[Priyono, P]]>;
<![CDATA[Nurhasanah, Iis]]>
<![CDATA[ Jurnal Penelitian Fisika dan Aplikasinya (JPFA) Vol 7, No 2 (2017) ]]>
Publisher : <![CDATA[Universitas Negeri Surabaya ]]>
Show Abstract
|
Download Original
|
Original Source
|
Check in Google Scholar
|
DOI: 10.26740/jpfa.v7n2.p61-67
<![CDATA[Mutu jelantah lebih rendah dibandingkan minyak goreng baru, karena mengandung produk-produk degradasi (radikal bebas, molekul lemak jenuh, total polar material, dan polimer). Jumlah produk degradasi dalam jelantah dapat diturunkan menggunakan lapisan tipis TiO2 yang memiliki sifat fotokatalis. Lapisan tipis TiO2 dibuat dengan mencampurkan TTiP dan AcAc dengan perbandingan molar 1:2. Campuran dideposisikan di atas substrat kaca dengan metode spray coating pada suhu 450 oC. Sebagian lapisan tipis yang sudah di-coating kemudian dianil pada suhu 500 oC selama 2 jam. Proses penurunan produk degradasi dalam minyak goreng dilakukan menggunakan lapisan tipis TiO2 tanpa anil dan lapisan tipis TiO2 yang dianil secara terpisah melalui proses fotokatalis. Proses fotokatalis dilakukan menggunakan matahari selama 5 jam. Keberadaan produk-produk degradasi dalam minyak goreng dikaji berdasarkan perubahan sudut polarisasi cahaya minyak goreng. Besarnya perubahan sudut polarisasi minyak goreng sebanding dengan jumlah produk degradasi. Tidak ada perbedaan yang signifikan pada kedua jenis lapisan tipis TiO2 dalam menurunkan produk degradasi. Setelah proses fotokatalis selama 5 jam, kedua jenis lapisan tipis TiO2 berhasil menurunkan jumlah produk degradasi yang sama yaitu hingga 71,43%. Hasil tersebut menunjukkan kedua jenis lapisan tipis TiO2 mampu mengurangi produk degradasi dalam jelantah.]]>
<![CDATA[PENGUJIAN SIFAT FOTOKATALIS LAPISAN TIPIS TiO2 PADA PRODUK DEGRADASI JELANTAH MENGGUNAKAN ELEKTROOPTIS ]]>
<![CDATA[Ummi Kaltsum]]>;
<![CDATA[Affandi Faisal Kurniawan]]>;
<![CDATA[P Priyono]]>;
<![CDATA[Iis Nurhasanah]]>
<![CDATA[ Jurnal Penelitian Fisika dan Aplikasinya (JPFA) Vol. 7 No. 2 (2017) ]]>
Publisher : <![CDATA[Universitas Negeri Surabaya ]]>
Show Abstract
|
Download Original
|
Original Source
|
Check in Google Scholar
|
DOI: 10.26740/jpfa.v7n2.p61-67
<![CDATA[Mutu jelantah lebih rendah dibandingkan minyak goreng baru, karena mengandung produk-produk degradasi (radikal bebas, molekul lemak jenuh, total polar material, dan polimer). Jumlah produk degradasi dalam jelantah dapat diturunkan menggunakan lapisan tipis TiO2 yang memiliki sifat fotokatalis. Lapisan tipis TiO2 dibuat dengan mencampurkan TTiP dan AcAc dengan perbandingan molar 1:2. Campuran dideposisikan di atas substrat kaca dengan metode spray coating pada suhu 450 oC. Sebagian lapisan tipis yang sudah di-coating kemudian dianil pada suhu 500 oC selama 2 jam. Proses penurunan produk degradasi dalam minyak goreng dilakukan menggunakan lapisan tipis TiO2 tanpa anil dan lapisan tipis TiO2 yang dianil secara terpisah melalui proses fotokatalis. Proses fotokatalis dilakukan menggunakan matahari selama 5 jam. Keberadaan produk-produk degradasi dalam minyak goreng dikaji berdasarkan perubahan sudut polarisasi cahaya minyak goreng. Besarnya perubahan sudut polarisasi minyak goreng sebanding dengan jumlah produk degradasi. Tidak ada perbedaan yang signifikan pada kedua jenis lapisan tipis TiO2 dalam menurunkan produk degradasi. Setelah proses fotokatalis selama 5 jam, kedua jenis lapisan tipis TiO2 berhasil menurunkan jumlah produk degradasi yang sama yaitu hingga 71,43%. Hasil tersebut menunjukkan kedua jenis lapisan tipis TiO2 mampu mengurangi produk degradasi dalam jelantah.]]>
<![CDATA[PENGARUH PENINGKATAN KONSENTRASI Fe PADA LAPISAN TIPIS TiO2 TERHADAP KEMAMPUAN FOTOKATALIS DALAM JELANTAH ]]>
<![CDATA[Ummi Kaltsum]]>;
<![CDATA[Joko Saefan]]>
<![CDATA[ Jurnal Ilmiah Teknosains Vol 4, No 2 (2018): JiTek ]]>
Publisher : <![CDATA[Universitas PGRI Semarang ]]>
Show Abstract
|
Download Original
|
Original Source
|
Check in Google Scholar
|
Full PDF (652.253 KB)
|
DOI: 10.26877/jitek.v4i2.2888
<![CDATA[Penambahan dopan Fe pada lapisan tipis TiO2 telah diketahui berhasil meningkatkan aktivitas fotokatalis dalam jelantah. Tujuan dari penelitian ini untuk mengetahui pengaruh peningkatan konsentrasi dopan Fe pada lapisan tipis TiO2 terhadap fotoaktivitas lapisan tipis. Lapisan tipis dibuat dengan mencampurkan TTiP, AcAc, etanol dan dopan Fe dari Fe(NO3)3.9H2O. Konsentrasi Fe divariasi dalam 1%, 2% dan 3%. Campuran tersebut selanjutnya dideposisikan pada substrat dengan metode spray coathing pada suhu 450 oC dan dianil pada suhu 500 oC selama 2 jam. Lapisan tipis yang terbentuk diuji karakteristiknya berupa morfologi, optis dan struktur kristal dengan SEM, UV Vis spektofotometer, dan xr-difractometer. Fotoaktivitas lapisan tipis diuji dalam jelantah selama 5 jam dengan sinar UV dan hasilnya ditentukan dengan metode titrasi. Hasil penelitian menunjukkan peningkatan konsentrasi dopan Fe meningkatkan kemampuan fotokatalis lapisan tipis. Kemampuan fotokatalis yang paling optimum dihasilkan oleh lapisan tipis Fe-TiO2 3% dengan penurunan ALB dan PV sebesar 45% dan 29%.]]>
<![CDATA[Peningkatan Kemampuan Pemecahan Masalah Siswa Melalui Penerapan Model Project Based Learning ]]>
<![CDATA[Bella Mirdza Mutia Dewi]]>;
<![CDATA[Nur Khoiri]]>;
<![CDATA[Ummi Kaltsum]]>
<![CDATA[ Jurnal Penelitian Pembelajaran Fisika Vol 8, No 1 (2017): APRIL 2017 ]]>
Publisher : <![CDATA[Universitas PGRI Semarang ]]>
Show Abstract
|
Download Original
|
Original Source
|
Check in Google Scholar
|
DOI: 10.26877/jp2f.v8i1.1331
<![CDATA[Telah dilakukan Penelitian yang bertujuan untuk mengetahui hasil penerapan model project based learning terhadap peningkatan kemampuan pemecahan masalah pada konsep Gravitasi menurut Newton. Penelitian ini dilakukan di MA Negeri Babakan Lebaksiu Tegal tahun pelajaran 2016/2017. Penelitian ini menggunakan desain eksperimen pretest-posttest control group design. Populasi penelitian ini adalah kelas XI IPA MA Negeri Babakan Lebaksiu Tegal. Teknik pengambilan sampel dengan menggunakan teknik simple random sampling dengan mengambil 2 kelas secara acak, kelas XI IPA 3 sebagai kelas eksperimen yang mendapat pembelajaran dengan model project based learning sedangkan kelas XI IPA 4 sebagai kelas kontrol yang menggunakan pembelajaran konvensional. Hasil penelitian menunjukkan bahwa terdapat perbedaan kemampuan pemecahan masalah fisika siswa kelas XI, dapat dilihat dari uji hipotesis satu pihak antara kelas eksperimen yang mendapat pembelajaran dengan menggunakan model project based learning dan kelas kontrol yang menggunakan pembelajaran konvensional diperoleh thitung > ttabel, yaitu 3,68 > 1,57 hal itu dapat disimpulkan Ha = diterima dan H0 = ditolak sehingga hasil nilai kemampuan pemecahan masalah siswa yang menggunakan model project based learning pada kelas eksperimen lebih baik dari kelas kontrol yang tidak diterapkan model project based learning.]]>
<![CDATA[The Role of Concentration Ratio of TTiP:AcAc on the Photocatalytic Activity of TiO2 Thin Film in Reducing Degradation Products of Used Frying Oil ]]>
<![CDATA[Ummi Kaltsum]]>;
<![CDATA[Affandi Faisal Kurniawan]]>;
<![CDATA[Iis Nurhasanah]]>;
<![CDATA[Priyono Priyono]]>
<![CDATA[ Bulletin of Chemical Reaction Engineering & Catalysis 2017: BCREC Volume 12 Issue 3 Year 2017 (December 2017) ]]>
Publisher : <![CDATA[Department of Chemical Engineering - Diponegoro University ]]>
Show Abstract
|
Download Original
|
Original Source
|
Check in Google Scholar
|
Full PDF (480.54 KB)
|
DOI: 10.9767/bcrec.12.3.951.430-436
<![CDATA[The TiO2 thin film has been applied to reduce degradation products (free fatty acid/FFA and peroxide value/PV) in used frying oil under ultraviolet (UV) light irradiation. FFA and PV are degradation products in used frying oil that can cause various diseases in human. In this study, the TiO2 thin films were made from precursor solution with concentration ratio of titanium tetraisopropoxide (TTiP) and acetylacetone (AcAc) of 1:1, 1:2, 2:1, 2:3, and 3:2. The aim of this study is to investigate the effect of concentration ratio of TTiP and AcAc on the photocatalytic activity of TiO2 thin film in reducing FFA and PV of used frying oil. The spray coating method was used to deposit precursor solution of TiO2 onto glass substrate at 450 oC. All TiO2 thin films consist of spherical-like grain with dominant structure of TiO2 rutile. The band gap energy of TiO2 thin films was in the range 3.11-3.16 eV. Concentration ratio of TTiP and AcAc of 2:3 results in TiO2 thin film with highest photocatalytic activity in reducing FFA and PV of used frying oil. ]]>
<![CDATA[Reduction of Peroxide Value and Free Fatty Acid Value of Used Frying Oil Using TiO2 Thin Film Photocatalyst ]]>
<![CDATA[Ummi Kaltsum]]>;
<![CDATA[Affandi Faisal Kurniawan]]>;
<![CDATA[Iis Nurhasanah]]>;
<![CDATA[Priyono Priyono]]>
<![CDATA[ Bulletin of Chemical Reaction Engineering & Catalysis 2016: BCREC Volume 11 Issue 3 Year 2016 (December 2016) ]]>
Publisher : <![CDATA[Department of Chemical Engineering - Diponegoro University ]]>
Show Abstract
|
Download Original
|
Original Source
|
Check in Google Scholar
|
Full PDF (492.641 KB)
|
DOI: 10.9767/bcrec.11.3.577.369-375
<![CDATA[The quality of used frying oil degraded due to the presence of products degradation, such as; PV and FFA which formed during the frying process. PV and FFA are harmful to human health. The photocatalytic activity of TiO2 thin film has been applied in various fields, especially in the environment. The aim of this study is to evaluate photocatalytic activity of TiO2 thin film for reducing PV and FFA in used frying oil. The TiO2 thin films were deposited on glass substrate by spray coating method at a temperature of 450 oC. The TiO2 precursor solution was prepared by mixing TTiP, AcAc, and ethanol. The thin films were varied into two conditions; as-deposited and annealed at a temperature of 500 oC. The morphology, crystalline structure, and optical properties of the thin films were characterized by scanning electron microscope (SEM), X-ray Diffraction (XRD), and UV-VIS spectrophotometer, respectively. The photocatalytic process was carried out by putting TiO2 thin film in used frying oil and irradiated by sunlight. The result showed that both of TiO2 thin films were still amorphous in nature. However, there was a peak with low intensity for annealed TiO2 thin film which corresponding to the TiO2 anatase crystals plane of (101). Annealing process improved crystallinity and changed the shape morphology of TiO2 thin films. The band gap was found to be 3.59 eV for as-deposited TiO2 thin film and 3.49 eV for the annealed-TiO2 thin film. The photocatalytic process shows that TiO2 thin films reduced FFA and PV of used frying oil up to 67.10% and 79.15%, respectively. Photocatalytic activity of annealed TiO2 thin film was higher than as-deposited TiO2 thin film. The results indicated that TiO2 thin film photocatalyst potential as the new alternative method to purify used frying oil. ]]>
<![CDATA[Numerical Study on the Effect of Mean Pressure and Loop's Radius to the Onset Temperature and Efficiency of Traveling Wave Termoacustic Engine ]]>
<![CDATA[Endang Dian Rokhmawati]]>;
<![CDATA[Irna Farikhah]]>;
<![CDATA[Ummi Kaltsum]]>;
<![CDATA[Harto Nuroso]]>;
<![CDATA[Aan Burhanudin]]>;
<![CDATA[Yuris Setyoadi]]>;
<![CDATA[Muhammad Amiruddin]]>;
<![CDATA[Irfan Abd Rahim]]>
<![CDATA[ Automotive Experiences Vol 3 No 3 (2020) ]]>
Publisher : <![CDATA[Automotive Laboratory of Universitas Muhammadiyah Magelang in collaboration with Association of Indonesian Vocational Educators (AIVE) ]]>
Show Abstract
|
Download Original
|
Original Source
|
Check in Google Scholar
|
Full PDF (1038.257 KB)
|
DOI: 10.31603/ae.v3i3.3881
<![CDATA[The thermoacoustic engine can be a device to convert waste heat energy in the engine car become useful energy such as for charging battery in car or Air conditioner of the car. This work can be done by experimentally and numerically. There are some parameters that have an impact on the performance of the engine. They are geometry of the engines, working fluid, and mean pressure. The performance of the engine depends on the efficiency and the heating temperature. In the car, waste heat energy is not high enough. Therefore, we need to utilize the low heating temperature to be converted into useful energy. This study contributes to numerically the effect of mean pressure and loop’s radius of the regenerator on the onset temperature and the efficiency of traveling wave thermoacoustic engines. The application that is used to solve numerical problems is fortran95. There are two codings that are used in fortran95. They are stability limits and efficiency codes. The lowest onset temperature that achieved is 153˚C with efficiency up to 38.1% that can be reached when the mean pressure is 4.0 MPa and the loop's radius is 5 cm. This result indicated that we can use low heating temperatures from waste heat of engine car to turn on electronics equipment inside the car.]]>
<![CDATA[Teaching Creative Thinking Skills with Laboratory Work ]]>
<![CDATA[Nur Khoiri]]>;
<![CDATA[Slamet Riyadi]]>;
<![CDATA[Ummi Kaltsum]]>;
<![CDATA[Nathan Hindarto]]>;
<![CDATA[Ani Rusilawati]]>
<![CDATA[ International Journal of Science and Applied Science: Conference Series Vol 2, No 1 (2018): International Journal of Science and Applied Science: Conference Series ]]>
Publisher : <![CDATA[Universitas Sebelas Maret ]]>
Show Abstract
|
Download Original
|
Original Source
|
Check in Google Scholar
|
Full PDF (495.83 KB)
|
DOI: 10.20961/ijsascs.v2i1.16722
<![CDATA[Research on figuring out the ways to teach creative thinking skills via learning processes has been carried out. One of the methods applied to be efficient to teach creative thinking skills is laboratory work. Laboratory work is an important process in learning physics since students tend to find it hard to understand physical concepts if they are only taught verbally. Students will understand better when they are given real life examples and are allowed to learn the concepts through the laboratory work, whenever possible. The research was conducted at SMAN 1 Bringin by employing the quasi-experiment pre-test - post-test control group design. Creative thinking skills were measured based on four indicators: flexibility, fluency, originality, and detail. Results show that laboratory work was suitable to improve students’ fluent thinking ability with 77% students showing improvement, and it was also a fit to improve students’ original thinking with 84% students showing improvement. The experiment class revealed a gain of 0.51, taken from an average pre-test score of 45.64 compared to the average post-test score of 73.5, which is an increase of 27.86. Meanwhile, the control class resulted in a gain of 0.40, taken from an average pre-test score of 39.11 compared to the average post-test score of 83.44, which is an increase of 24.33.]]>
