283 research outputs found
Synthesis of Cuprum (Cu) Layer by Electrodeposition Method with Theobroma cacao Peels as Corrosion Protector of Steel
Get PDFCorrosion is a natural phenomenon that can not be prevented the process of occurrence, but the timing may be delayed. Various efforts have been made in reducing the impact of losses caused by corrosion. One such effort is to coat the metal surface with a thin layer. As well as other efforts is to use an inhibitor. Efforts have been made to reduce the impact of corrosion loss by synergizing surface coating and using of inhibitors. Deposition of a thin layer of Cu using electrodeposition method with 0.05 M CuSO4.5H2O electrolyte solution and addition of inhibitor of Theobroma cacao peels extract. In this research has been done some variation that is variation of electrodeposition time and variation of concentration of inhibitor of Theobroma cacao peels extract. Scanning Electron Microscope (SEM) characterization shows electrodeposition of a thin layer of Cu for three minutes, a voltage of three volts, and with the addition of an inhibitor of Theobroma cacao peels extract 1% producing a smooth, homogeneous and more uniform surface morphology. Based on the result of characterization with X-Ray Diffraction (XRD) obtained steel surface at electrodeposition with the addition of an inhibitor of Theobroma cacao peels extract, there are sharper peaks of Cu. Based on the corrosion test obtained value of Inhibition Efficiency inhibitor of Theobroma cacao peels extract amounted to 69.4% with the addition of 1%, and 81.9% with the addition of inhibitor 1.5%. Â Based on this, inhibitor of Theobroma cacao peels extract can reduce the attack rate of corrosion on the steel surface in corrosive media HCl 1N
INHIBISI KOROSI DAN PEMULIHAN SIFAT MEKANIK BAJA LUNAK MENGGUNAKAN EKSTRAK KULIT BUAH KAKAO (Theobroma cacao) DALAM MEDIA ASAM
No full textINHIBISI KOROSI DAN PEMULIHAN SIFAT MEKANIK BAJA LUNAK MENGGUNAKAN EKSTRAK KULIT BUAH KAKAO (Theobroma cacao) DALAM MEDIA ASAM
No full textInhibisi korosi dan sifat-sifat adsorpsi oleh ekstrak kulit buah kakao (Theobroma cacao) pada baja lunak dalam larutan HCl 1,5 mol/L dipelajari menggunakan teknik metode berat hilang (weight loss), polarisasi potensiodinamik (Tafel), dan Electron Impedance Spectroscopy. Variabel penelitian adalah konsentrasi ekstrak 0,5-2,5% dengan selang 0,5%, waktu, dan rentang suhu 30-50 red, dan LC-MS dilakukan untuk mengetahui senyawa ekstrak yang berperan dalam proses inhibisi. Sedangkan XPS dan XRD dilakukan untuk mengetahui adsorpsi yang terjadi di permukaan baja lunak. Morfologi permukaan dari sampel diamati dengan menggunakan scanning elektron microscopy dengan energy dispersive X-ray spectroscopy (SEM-EDX)
Karekteristik Hidroksiapatit (HA) Dari Limbah Tulang Sapi dengan Metode Mekanik-Termal
Get PDFThe availability of bovine bone waste is very abundant and has not been utilized optimally as raw material for the manufacture of Hydroxyapatit (HA).HA is widely used in the field of orthopedics and dentistry, because it is biocompatible and bioactive, bovine bone wastes are synthesized by thermal-mechanical methods to obtain HA. The first stage of bovine bone preparation is done to obtain HA from bovine bone waste by mechanical collision to obtain bone meal smooth. The second stage of calcination at a temperature of 800oC. The results of microstructural observation with SEM obtained granules obtained almost evenly smoothness with average size 42.25 μm in span (irregular spherical (30.29-136.4μm) and chemical composition with XRF obtained by Ca / P ratio of 1.61, close to the optimal value of HA of 1.67
NASKAH PRIMBON HIRZ AL-YAMANI (Suntingan dan Kajian Isi Teks)
Get PDFYuli Tri Hastuti. 2018. Primbon Text Hirz Al-Yamani: (Editing and Study of Text Content) Thesis. Indonesian Literature Department, Faculty of Cultural Sciences. Diponegoro University. Semarang. Advisor: Dr. Muh. Abdullah, MA The Primbon Hirz Al-Yamani manuscript is a collection of the National Library of the Republic of Indonesia (PNRI) with the catalog number Br7 which reads Arabic Pegon. The Primbon Hirz Al-Yamani manuscript is a form of prose which contains the functions and benefits of hirz prayer. In this study, data sources are divided into two, namely primary data and secondary data. Primary data sourced from Primbon Hirz Al-Yamani texts obtained through catalog studies in museums or libraries. Secondary data comes from books or other sources that are located as supporting research. The theory used in this study is the theory of philology and mimeic theory. Philological theory is used to get translations and edits of text. The text editing method used in this study is the standard method. In addition, to find out the contents contained in the Primbon Hirz Al-Yamani text, the authors use mimetic theory. The mimetic model used in this study is mimetic according to Abrams. Based on the analysis conducted by the author, the Primbon Hirz Al-Yamani text is a pesantren literary text containing Isim A'zhom in it. To get a practice, Hizib must go through a diploma directly to a teacher and ask for his guidance directly. Keywords: Primbon Hirz Al-Yamani manuscript, philology, mimetic
Problems of Russian Theatrical Reception of Shakespeare in Criticism of Yuli Eichenwald
Get PDFThe problem of this study lies in evaluating the methodological approach of Yuli Eichenwald (1872—1928) as a theatrical critic and theorist, specifically his writings on Shakespearean productions both in Russia and abroad. Known primarily as a literary critic, Eichenwald also wrote about theater, but his works in this area have been largely unexplored. The aim of this study is to shed light on Eichenwald's principles of theatrical criticism. The material used consists of little-known articles by Eichenwald on theater theory and Shakespearean productions from 1903 to 1927. The research employs hermeneutic and comparative methods. The findings reveal that Eichenwald demonstrates a literature-centric position in his articles on theater, according to which theater is merely an illustration of literary works. He increasingly uses productions as a pretext to discuss Shakespeare, often without mentioning the actors or directors. Eichenwald’s perception of theater as a mediator, as an auxiliary device between the play and the reader, leads to his rejection of the concept of directorial theater and the denial of the director as the author of the production. The authors conclude that Eichenwald’s theatrical criticism is a logical outcome of literature-centric judgments about theater, from Aristotle to Hegel, where theater is considered as part of literature
Perencanaan Perawatan Mesin Pengupas Kulit Pinang
Get PDFPlanner engine maintenance is an important thing to streamline the production process. Care planning for areca nut peeler has been carried out which includes the engine frame, electric motor, pulleys, V-belts, reservoirs, and spindle shaft. These components are expected to work optimally so that satisfying results are obtained. The care of the areca peeling machine consists of preventive treatments, repair treatments, total treatments. Preventive care consists of cleaning, lubrication and periodic checks. Repair treatments include blade maintenance, bearing maintenance, pulley care and belt. While total maintenance is carried out after the engine has been operating long enough. The results of treatment planning are made in the form of a treatment table. While the results of the maintenance process that has been done by the machine can operate properly and can produce maximally
Pengaruh Ukuran Partikel Kulit Buah Kakao Terhadap Sifat Fisik, Mekanik dan Termal Papan Partikel dari Kulit Buah Kakao dan Serat Ampas Tebu
Get PDFTelah dilakukan penelitian tentang pembuatan papan partikel dari kulit buah kakao dan serat ampas tebu yang bertujuan untuk menganalisis pengaruh ukuran partikel serbuk kulit buah kakao yang ditinjau dari sifat fisik, mekanik dan termal papan partikel. Parameter yang diukur adalah kadar air, densitas, daya serap air, kuat lentur, kuat patah, dan termal. Papan partikel ini dibuat dengan 5 variasi serbuk kulit buah kakao yaitu lolos ayakan 149, 177, 250, 400, dan 841 µm dengan panjang serat ampas tebu 3 cm. Komposisi bahan kulit buah kakao dan ampas tebu adalah 50:50 dan kadar perekat isosianat 16%. Hasil sifat fisik didapatkan adalah nilai kadar air berkisar 9,27-13,05%, nilai densitas berkisar 0,89-1,23 g/cm3 dan nilai daya serap air berkisar 11,13-52,28%. Hasil uji sifat mekanik didapatkan adalah nilai kuat lentur 2,8×103-7,8×103 kg/cm2 dan nilai kuat patah berkisar 1,43×104-2,48×104 kg/cm2. Hasil pengujian sifat konduktivitas termal didapatkan berkisar 7,26×10-3-9,0×10-3 W/m°C. Ukuran partikel kulit buah kakao yang baik sebagai bahan pembuatan papan partikel adalah lolos ayakan 149 µm.Dari keseluruhan hasil pengujian disimpulkan bahwa ukuran partikel serbuk kulit buah kakao mempengaruhi pada sifat fisik, mekanik dan termal papan partikel. Semakin kecil ukuran partikel serbuk kulit buah kakao maka nilai densitas, kuat lentur, kuat patah dan konduktivitas termal papan partikel akan semakin tinggi. Pada pengujian kadar air dan daya serap air semakin kecil ukuran partikel kulit buah kakao maka semakin rendah nilai pengujian tersebut. Hasil penelitian menunjukkan bahwa sifat fisik dan mekanik papan partikel yang didapatkan pada pengujian telah memenuhi standar SNI 03-2105-2008 kecuali pada pengujian densitas dan kuat lentur. Berdasarkan persentase densitas papan partikel maka papan partikel yang dihasilkan termasuk jenis papan partikel berkerapatan tinggi.Kata kunci: serbuk kakao, papan partikel, konduktivitas termal, sifat fisik, sifat mekanik
Corrosion Inhibitor of Mild Steel by Polar Extract of Theobroma cacao Peels in Hydrochloric Acid Solution
No full textPENGARUH KONSENTRASI INHIBITOR EKSTRAK DAUN KAKAO (Theobroma cacao) TERHADAP LAJU KOROSI BAJA HARDOX 450
Get PDFABSTRAKTelah dilakukan serangkaian uji korosi dan analisis struktur mikro terhadap baja Hardox 450. Penelitian ini dilakukan dengan menggunakan medium korosif H2SO4 3% dan Na2SO4 3%. Metode yang digunakan adalah metode weight loss untuk pengukuran laju korosi dan metode potensiodinamik untuk melihat nilai arus korosi beserta potensial korosi. Baja direndam di dalam medium korosif dengan penambahan dan tanpa penambahan inhibitor. Variasi konsentrasi inhibitor yang digunakan adalah dari 1% hingga 10% dengan lama perendaman lima hari. Hasil penelitian menunjukkan bahwa dari variasi konsentrasi yang diberikan laju korosi terbesar terjadi pada baja tanpa penambahan inhibitor, sedangkan laju korosi berkurang dengan penambahan inhibitor, terlihat dari kurva Tafel yang menunjukkan penurunan Ikorosi. Semakin besar konsentrasi inhibitor yang ditambahkan maka nilai laju korosi akan semakin menurun dan nilai efisiensi inhibisi korosi semakin tinggi. Nilai efisiensi terbesar didapatkan pada penambahan konsentrasi inhibitor 10%, untuk medium korosif H2SO4 mencapai 63,89% dan untuk medium Na2SO4 mencapai 56,61%. Hal ini menunjukkan bahwa inhibitor ekstrak daun kakao efisien dalam mengendalikan laju korosi dalam medium H2SO4 dan Na2SO4. Dari analisis foto optik morfologi permukaan baja Hardox 450 memperlihatkan permukaan baja dengan penambahan ekstrak daun kakao mengalami korosi lebih sedikit.Kata kunci : laju korosi, inhibitor, efisiensi, weight loss, potensiodinamikAbstractThe corrosion test and microstructure analysis of Hardox 450 steel have been done. This research was performed using H2SO4 3% and Na2SO4 3% corrosive mediums. The method used were weight loss for measuring the corrosion rate and potentiodynamic method to see the value of corrosion current and corrosion potential. Steel immersed in the corrosive medium with the addition and without addition of inhibitors. Concentration variation of inhibitor used was from 1% to 10% with five days immersion time. The result based from concentration variation was used showed that the corrosion rate occured in the steel without the addition of inhibitors, whereas the corrosion rate decreases with the addition of inhibitors, by the Tafel curves showed a decreases Icor. The greater concentration of the inhibitor is added then the value of corrosion rate will lower and corrosion inhibition efficiency will increase. Greatest efficiency values both for medium corrosive obtained at inhibitor concentration 10%, 63,89% in H2SO4 and 56,61% in Na2SO4. It shows that the cocoa leaf extract inhibitor is efficient in controlling corrotion rate in H2SO4 and Na2SO4 medium corrosive. From the optical photograph analysed on the surface morphology of Hardox 450 steel showed that the addition of cocoa leaves extract suffered less corrosion.Keywords: corrosion rate, inhibitor, efficiency, weight loss, potentiodynami
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