Articles

ANALISIS RETAKAN KOROSI TEGANGAN PADA ALUMINIUM DENGAN VARIASI PEMBEBANAN DALAM MEDIA KOROSI HCL 1M Handayani, Dewi; Bayuseno, Athanasius Priharyoto
JURNAL TEKNIK MESIN Vol 2, No 2 (2014): VOLUME 2, NOMOR 2, APRIL 2014
Publisher : Jurusan Teknik Mesin, Fakultas Teknik, Universitas Diponegoro

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Stress corrosion cracking [SCC] merupakan kegagalan logam korosi hasil peretakan intergranular atau transgranular dibawah pengaruh antara tegangan tarik dan lingkungan korosif. Bentuk korosi ini lazim sekali dijumpai di lingkungan industri seperti : industri perkapalan, perminyakan, dan industri ? industri kontruksi logam. Dalam tugas akhir ini dimaksudkan untuk memahami fenomena Stress Corrosion Cracking secara teoritis dalam aluminium dengan mengkaji pengaruh variasi pembebanan didalam media korosi terhadap pertambahan panjang, lamanya waktu patah dan jenis retak. Pada penelitian ini pengujian menggunakan alat uji Stress Corrosion Cracking, untuk menciptakan suatu kondisi spesimen agar mendapatkan tegangan  tarik pada lingkungan yang korosif. Tegangan yang diberikan berupa tegangan tarik yang berasal dari pembebanan statik pada sistem pengungkit. Kondisi korosif dapat dihasilkan dari bak yang diisi dengan larutan HCl. Analisa metalografi dimaksudkan untuk mengamati struktur mikro spesimen uji dan bentuk retak yang terjadi pada spesimen uji setelah dilakukan proses pengujian.
PENGEMBANGAN DATABASE SPASIAL ZONA AGRI-CULTURAL UNTUK ESTIMASI HASIL PRODUKTIFITAS PADI BERBASIS SISTEM INFORMASI GEOGRAFI Studi Kasus: Wilayah Kabupaten Pemalang Jawa Tengah: Prosiding Seminar Nasional MIPA UNNES 24 OKTOBER 2009 Handayani, Dewi
Publikasi Eksternal 2009
Publisher : Publikasi Eksternal

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Analisa estimasi hasil produktifitas padi dilakukan sebagai salah satu jawaban dari skenario sistem produksi padi yang bisa digunakan untuk memprediksikan hasil panen setiap tahunnya dengan berdasar tolok ukur kondisi alam dan eksperimen area sawah percontohan serta curah hujan untuk mengetahui hasil tanaman padi yang bisa dipanen setiap tahunnya.Database spasial dibuat berisi informasi tentang sumberdaya lahan yang meliputi struktur tanah, iklim, hidrologi, irigasi, sistem pemakaian lahan, dan hasil panen yang nantinya bisa digunakan untuk model dalam melakukan estimasi hasil produktifitas padi yang bisa diakses secara cepat dalam manejemen sumber daya lahan untuk pengembangan perencanaan pertanian. Pengembangan Database zona Agro-cultural yang terbentuk memiliki stuktur topologi data spasial dan tabular, dan bisa digunakan sebagai data dasar untuk membuat bermacam aplikasi yang berbasis Sistem Informasi Geografi. Database internal terbentuk secara otomatis dari hasil rancangan data spasial, database ekternal bisa direlasikan dengan database internal untuk menghasilkan database Sistem Informasi Geografi yang baru hasil penggabungan. Kata kunci: Database Spasial ,Sistem Informasi Geografi, Estimasi Produktifitas Padi. Disampaikan di Seminar Nasional MIPA UNNES 24 OKTOBER 2009
KELAYAKAN FINANSIAL LAYANAN OJEK DI KABUPATEN WONOGIRI JAWA TENGAH Handayani, Dewi; Ariyani Soemitro, Ria Asih; Budisatrya Mochtar, Indrasurya; Riyanto, Bambang
Jurnal Transportasi Vol 11, No 2 (2011)
Publisher : Jurnal Transportasi

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Ojek (motorcycle paratransit) is one form of paratransit in Indonesia, using a motorcycle rented by a person and gives the person a lift. By evaluating the feasibility of ojek services, the sustainability of ojek as a mode of transportation in a rural area can be determined. This research was conducted on ojek services in Wonogiri, Central Java Province. The results indicate that the investment of ojek services for rural areas is feasible to be implemented because it meets the feasibility criteria used in the analysis. The prospect of the existence of ojek in the rural areas in the future is also quite good and is expected to take place for long time, especially in areas with limited formal employment, relatively low education level of job seekers, and low-wage workers.Keywords: paratransit, ojek, rural transportation, feasibility analysis.
The Design Of Hot Mixture Thin Surfacing Containing Asbuton Modified Bitumen For Hot And Arid Region Kabbash, Omar Muhamed; Setyawan, Ary; Handayani, Dewi
Jurnal Teknik Sipil Vol 2, No 2 (2014): Jurnal Teknik Sipil
Publisher : Jurnal Teknik Sipil

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Hot arid region is a region when it is characterized by a severe lack of available water and has a high temperature like Australia and Africa. In this condition, hot mix asphalt (HMA) thin surfacing is chosen for road preservation. This study is aimed to study about modified asbuton for hot mix asphalt by thin surfacing overlay. For bitumen modified, researcher used three types of asphalt (asphalt penetration 60/70, retona blend 55 and polymer SBS) specimen which be add with 5%, 5.5%, 6%, 6.5% and 7% for each sample with thickness of 30mm. Moreover, for the temperature test, it was tested at 20oC until 60oC. The test showed that polymer SBS can be used as a binder for alternative industrial asphalt in flexible pavement at hot and arid region. Polymer SBS is good material that has same sensitivity in the different temperature. Result of marshall test showed that Polymer SBS more stable than asphalt penetration 60/70 and retona blend 55. Polymer SBS also has the highest density. Retona blend 55 has the better result for the test average that was conducted in this study. Keyword: HMA, thin surfacing, asbuton, bitumen, hot and arid.
PERBANDINGAN HASIL BELAJAR SISWA MENGGUNAKAN MEDIA DAILY CHEMQUIZ DAN PERMAINAN RANKING ONE CHEMISTRY QUIZ Utari, Tiya Rurin; Bahar, Amrul; Handayani, Dewi
Alotrop Vol 1, No 2 (2017)
Publisher : FKIP University of Bengkulu

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[COMPARISON OF STUDENTS LEARNING RESULT USING MEDIA Daily Chem Quiz AND GAMES Ranking One Chemistry Quiz]  The aim of this research is to know the difference of students' chemistry learning result using Daily Chem Quiz (DC Quiz) and Ranking One Chemistry Quiz (ROC Quiz) media at class X MIPA in SMA Negeri 1 Bengkulu Tengah 2016 / 2017 academic year. This research is quasi research experiment. The independent variables are DC Quiz and ROC Quiz media, the dependent variable is the students' learning result and the control variable is the Think-Pair-Share (TPS) cooperative learning methods. The population is all students of class X MIPA at 2016/2017 academic year consisting of 4 classes, and to determine the sample is done by homogeneity test then taken by simple random sampling. The selected sample is the class X MIPA 3 as experiment class I using DC Quiz and class X MIPA 1 as experimental class II using RC Quiz . Data analysis used were mean score, normality test, homogeneity test, and t test. Based on posttest value of both class, it is known that the average value of posttest at experiment class I is 78.79 and at  experiment class II is 84,77. The result of data analysis shows that the data is normally distributed and has homogeneous variance and obtained t count> ttabel (2,47> 2,39). The results of this study indicate that H0 rejected and Ha accepted in other words there is a significant difference between student learning outcomes using DC Quiz media and RC Quiz media.
UJI AKTIVITAS ANTIBAKTERI DAUN JERUK KALAMANSI (CITROFORTUNELLA MICROCARPA) TERHADAP BAKTERI STAPHYLOCOCCUS AUREUS DAN ESCHERICHIA COLI Oktasila, Deza; Nurhamidah, Nurhamidah; Handayani, Dewi
Alotrop Vol 3, No 2 (2019)
Publisher : FKIP University of Bengkulu

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This study aims to examine the antibacterial activity of ethanol extract and essential oil of Kalamansi citrus leaves (Citrofortunella microcarpa) against Staphylococcus aureus and Escherichia coli bacteria. The raw material of Kalamansi citrus leaves is obtained from the Village of Pondok Kubang, Bengkulu Tengah (3.70060S, 102.35780E). Ethanol extract from Kalamansi citrus leaves was obtained by maceration using ethanol 96%, then ethanol extract was made dilution concentration 40 ; 20; , 10; and 5%. The essential oil of Kalamansi citrus leaves is obtained by water-vapor distillation, then made variations of concentration 20;, 15;, 10;  and 5%. The method used to test the antibacterial activity is the paper disc diffusion method , the antibacterial activity is shown by the diameter of the inhibiting  zone formed. The data of antibacterial test result were analyzed by using One Way Anova test which showed the effect of treatment on the growth of test bacteria seen from the value (P <0,01) and continued by Duncan test to know the effect of the treatment. The results showed that ethanol extract of Kalamansi citrus leaves had antibacterial activity against S. aureus and E. coli bacteria with moderate inhibitory diameter is  7.20 and 5.73 mm at concentration 40%, while antibacterial activity on essential oil of Kalamansi citrus leaves is categorized as strong with inhibition zone diameter is 14.83 and 13.00 mm at concentration 20%.
UJI BIOFUEL HASIL PERENGKAHAN METIL ESTER DARI LIMBAH CAIR PABRIK MINYAK KELAPA SAWIT DENGAN KATALIS MONI/HZ Sari, Dian Kartika; Sundaryono, Agus; Handayani, Dewi
Alotrop Vol 1, No 2 (2017)
Publisher : FKIP University of Bengkulu

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[CONVERSION OF LIQUID WASTE OIL PALM OIL FACTORY BECOME BIOFUEL WITH MONi / HZ CATALYST] This study aims to produce biofuel from liquid waste oil PMKS with worditik cracking using catalystMoNi / HZ. This study involves the preparation of a catalyst performed by means of a separate impregnation, this impregnation lasting for 12 hours. The next stage of sample preparation includes heating, filtering, degumming, bleaching and ALB determination, followed by the production of methyl esters through esterification and transesterification processes. Then the obtained methyl ester was cracked using a catalyst for 2 hours at 380 °C and followed by distillation of the product for 2 hours at 380 °C, followed by distillation step at 380 °C to obtain methyl ester. The physical characteristics of biofuel resulting from the catalytic cracking reaction of the methyl ester using the MoNi / HZ catalyst of the PMKS wastewater include the acid number 1.92 mg KOH / g, density 0.803 g/cm3, kinematic viscosity 1,113 cSt, a pour poin of 0oC and fog poin at 1,43 oC. Biofuel resulting from catalytic cracking using this MoNi / HZ catalyst of very high biofuel acid numbers can be used in areas that have a cold climate. the biofuel viscosity of the experimental results has not matched the viscosity of gasoline or kerosene, so it can not be used as fuel equivalent to gasoline and kerosene with the composition of 100% biofuel density from biofuel is still slightly above gasoline and kerosene
PROFIL FITOKIMIA DAN PENGARUH EKSTRAK TANGKAI DAUN TALAS KEMUMU (COLOCASIA GIGANTEA HOOK.F ) TERHADAP JUMLAH LEUKOSIT MUS MUSCULUS Asri, Rofiqa; Handayani, Dewi; Sundaryono, Agus
Alotrop Vol 3, No 1 (2019)
Publisher : FKIP University of Bengkulu

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This research aims to identify secondary metabolite compounds in Talas kemumu leaf stalk (Colocasia gigantea Hook.f) and to determine the effect of extract on the number of male Mus musculus leukocytes that have been induced aspirin. Aspirin is used to increase the number of M.musculus leucocytes.The method used in this research is the method of extraction by maceration to attract secondary metabolites of active compounds  C.gigantea leaf stalk and the measurement of blood leukocyte counts are calculated using a hemocytometer (improved neubauer). Test of the effect of the leaf stalk of C.giganteaextract on the number leukocytes of M.musculus  was performed by dividing into 5 groups with 5 replications according to the Federer formula, namely K (-) were given distilled water, K (+) were given aspirin, P1, P2 and P3 are each given a dose of extract of  C.gigantea leaf stalk of 0,028 g/KgBB, 0,056 g/KgBB and 0,084 g/KgBB. The results showed that the identification of phytochemical profile in C.gigantea leaf stalk contains secondary metabolite compounds such as alkaloids, flavonoids, terpenoids, tannins and saponins. The results shows that giving of C.gigantea leaf stalk extract can reduce the number of leukocytes M.musculus which have induced aspirin. The giving of C.gigantea leaf stalk extract can decrease the number of aspirin-induced M.musculus leukocytes. This is evident from the results of One Way Anova analysis and the Smallest Real Difference Test (BNT) because in each treatment group has a significant influence. The effective dose that has the greatest activity in decreasing the number of M.musculus leukocytes found in the P1 treatment of 0,028 g /KgBB can decrease the blood leukocyte count by 6,830 / mm3.
PENERAPAN MODEL PEMBELAJARAN AUDITORY, INTELLECTUALY DAN REPETITION (AIR) DENGAN MENGGUNAKAN MEDIA PEMBELAJARAN KARTU ARISAN UNTUK MENINGKATKAN AKTIVITAS DAN HASIL BELAJAR SISWA KELAS X MIA 1 SMAN 8 KOTA BENGKULU Sumiati, Diana; Bahar, Amrul; Handayani, Dewi
Alotrop Vol 3, No 2 (2019)
Publisher : FKIP University of Bengkulu

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This study aimed to improve learning activities and learning outcomes of students in class X MIA 1 of Senior High School (SMAN) 8 Bengkulu on the subject of chemical bonds through the application of Auditory, Intellectualy, and Repetition (AIR) learning models by using learning media with lottery card. This study is a classroom action research consisting of three cycles, each cycle consisting of four stages, planning, action, observation and reflection. In collection of data was done by non-test and test methods, teacher observation sheets, student observation sheets and post-test. The data was processed by using simple quantitative data analysis techniques, the total value of each student, the average value, the percentage of absorptive power, learning completeness and the average observation score.The results of the study in the 2018/2019 school year showed that the application of the Auditory Intellectualy Repitition learning model using learning media with lottery  cards in class X MIA 1 of SMA Negeri 8 Kota Bengkulu could improve teacher activities, student activities and student chemistry learning outcomes. This can be seen from the average score of teacher activities in the first cycle to the third cycle in a row : 23, 27.5 and 31.5. Student activity also showed improvement in each cycle. The average score of student activity in cycle I to cycle III was sequentially 20, 25 29.5. Learning outcomes also increase in each cycle. This can be seen from the average value of the test results in each cycle, in the first cycle of 61.82, in the second cycle of 67.88, in the third cycle of 79.09. Classical absorption in cycle I, cycle II, cycle III are 61.82%, 67.88%, 79.09%, with the percentage of completeness learning in each cycle of 42%, 73%, and 87.8 %.
SINTESIS METIL ESTER DARI LIMBAH KELAPA SAWIT DENGAN SONOCHEMISTRY DAN CRACKING MENJADI BIOFUEL DENGAN KATALIS CRMO/HZ Dhani, Jertadi Putri; Sundaryono, Agus; Handayani, Dewi
Alotrop Vol 3, No 2 (2019)
Publisher : FKIP University of Bengkulu

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This study aims to calculate the percentage methyl ester converted to biofuel through catalytic cracking reaction,analyzes component and determine characteristics using catalyst CrMo/HZ. This research begins with impregnation sample preparation which includes heating oil,degumming,bleaching and determination free fatty acid (FFA). Methyl ester obtained from liquid waste conversion crude palm oil through an esterification and transesterification reaction with H2SO4 and NaOH catalyst with sonochemistry methode is a method that utilizes ultrasonic waves origanating from a device is ultrasonic cleaner for one hour at temperature 60oC. The methyl ester obtained was cracked with a CrMo/HZ catalyst which was carried out for 2 hours at temperatur 380oC. To find out the components of compounds formed in methyl ester, an analysis was performed using GCMS then characteristics of biofuel are determined from the result of catalytic cracking obtained through acid number testing,density,viscosity,pour point and fog point. The result obtained from the conversion of methyl ester to biofuel with Crmo/HZ Catalyst Is 60,17% And For Testing The Physical Characteristics Of Biofuel Namely The Acid Number 1,87 Mg KOH/G, density 0,804 g/cm3, viscosity 1,162 Cst, pour point 0oC and fog point 1,4oC. The result of cracking produce a consituent component of biofuel namely gasoline 33,67%, kerosene 16,26%, gas oil 10,24% beside that, there are still methyl ester as much as21,89%.
Co-Authors ,, Meliana ,, Purwantiningsih Abdusysyakur, Muhammad Agus Sundaryono Alhamd, Laode Alhamd, Laode Amirullah, Gufron Amrul Bahar, Amrul Andari, Kadek Dewi Wahyuni ANDRIA AGUSTA Andriani, Erlita Apriyudha, Ryan Arief Rahman Hakim Ary Setyawan Asngad, Achmad Bagus Asri, Rofiqa Athanasius Priharyoto Bayuseno Bambang Riyanto Bua, Agustinus Toding Dewanto, Fajar Dhani, Jertadi Putri Dian Kartika Sari, Dian Kartika Dian Retno Anugrah, Dian Retno Djoko Sarwono Djumari Djumari Erva Rosa Prima Gayatri, Erva Rosa Prima Fadhli, M. Zuhdi Fauzi, Ichsan Ali Firdausy, Sabila Galandika, Fafip Gusti, Nina Hadi, Galih Setyo Hadiani, Raden Roro Rintis Hadiani, Raden Roro Rintis Haryamurti, Jessy Tidar Hasanah, Fina Hermawan, Faisal Kus Hery Suyanto HM, Amirotul M Indrasurya Budisatrya Mochtar Jati, BR Revandy Baskara Jaya, Yocky Indra Joeni Setijo Rahajoe Julia Sarfina, Julia Julita Sari, Julita Jumiarni, Dewi Kundarto, Rahmat Kurniawan, Robbi Kusumananti, Praditya Dwi Laksono, Dhony Eko Legowo, Slamet Jauhari Legowo, Slamet Jauhari Legowo, Slamet Jauhari Legowo Mahmudah, Amirotul M.H Mahmudah, Amirotul M.H Mahmudah, Amirotul M.H. Mahmudah, Amirotul MH Mahmudah, Amirotul MH Mahmudah, Amirotul Musthofiah Meylisa, Herlyn MUHAMMAD HASBI Muryati, Tyas Sri Musthofiah, Amirotul Muttaqin, M. Zaenal Muzanip Alperi, Muzanip Ni Nyoman Rupiasih Novitiana, Lydia Novitriana, Lydia Nur, Ressyana Nurhamidah Nurhamidah Nurhidayati, Lydia Novitriana Oktasila, Deza Omar Muhamed Kabbash Omar Muhamed Kabbash1, Omar Muhamed Ophelia, Rahma Ori Pambudi, Risma Parade, Aang Pramudya, Hananta Aji Prasetya, Sandy Prasiwi, Dhea Pratama, Agri Alan Pratiwi, Irda Nurul Prawira, Raffel Muna Primasari, Revina Anggraeni Purnomoasri, Raden Ajeng Dinasty Puspitasari, Selviana Tikna Putri, Hera Cahyaning Rahadi, Rizky Setyo Ramadenti, Fuji Retno Widowati Ria Asih Ariyani Soemitro Rustomo, Oscar Bintang Ryandhini, Hanifa Indira S. Achmadi, Suminar S. Achmadi, Suminar Safitri, Isnaini Salastri Rohiat, Salastri Sembiring, Fransisca Theresia Setiono Setiono Sobriyah Sobriyah Suciati, Rizkia Sumarsono, Agus Sumarsono, Agus Sumiati, Diana Sumpono Sumpono, Sumpono Surompo, Bimma Ajiwijaya Susilo Susilo Tamimi, Dzul Khairina Trinanda, Ririn Utari, Tiya Rurin V Lubis, Jessica Rotua Wahyuni, Nadya Dirma Widi Hartono Widuri, Anisa Priyandini Wulan Agustina Yuniarso, Endhit