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The Influence of Position and Number of Longitudinal Connection of Sengon Glulam Beams Towards Strength and Stiffness Sutarno Sutarno; Prayitno Prayitno; Adreas Triwiyono
International Conference on Coastal and Delta Areas Vol 3 (2017): The 3rd International Conference on Coastal and Delta Areas
Publisher : International Conference on Coastal and Delta Areas

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

The demand of wood as construction material always increases. However, sawn-wood with large size is more difficult to find in the market due to decreasing in stock dimension. In addition, it makes price more expensive. Indonesia has many trees from fast-growing species: however, they have low wood quality, and still limited in usage. To obtain a better performance of fast-growing species as construction material, it needs to be combined to produce glulam. This research observed the influence of position and longitudinal connections of wood glulam beam on strength and stiffness with damage species of sengonglulam beams. Preliminary testing was done to obtain physical and mechanical properties of clear specimen of sengon wood, testing method followed ISO-1995 standard. Fifteen glulam beam specimens whichhad 70 mm wide, 200 mm depth, 3000 mm length were constructed: They represented variations of position and connection work of 0 %, 25 %, 50 %, 75 % and 100 %. Each layer of lumber glued with thermosetting phenol formaldehyde (PA-302) adhesive at pressure 1 up to 1,1MPa for 10 hour pressing time. The static lateral loading steps were done continuously until the beam was damaged. The result indicated that sengonwas V class of strength. Glulam testing showed that in terms of strength and stiffness, the higher the number of connections, the lower the value. The strength reduction percentages of 0%, 25%, 50%, 75% and 100% produced 0%, 13,08%. 28,11%. 29,42%. 70,72 %. Respectively and the degradation of glulam stiffness were 100%. 99,92%. 87,86%. 83,06%. 67,08%. The failure of glulam beam with 0% had a shear followed by flexure damages of 25%, 50%, 75% and 100%. A flexure damage was followed by shear damage. Keywords: Paraserianthesfalcataria, Connection, Glulam Beam, Strength, Stiffness.
Kajian penerapan bioteknologi pengolahan kulit untuk mengurangi limbah Prayitno Prayitno
Majalah Kulit, Karet, dan Plastik Vol 26, No 1 (2010): Majalah Kulit, Karet, dan Plastik
Publisher : Center for Leather, Rubber, and Plastic Ministry of Industry, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (2407.842 KB) | DOI: 10.20543/mkkp.v26i1.243

Abstract

In its wider scope, biotechnology has been used in the tanning industry for several years, since the inception of enzyme utilization. Enzyme in leather processing can be successfully applied at the several stage of processes. At the soaking, enzyme was able to decrease soaking time from 7 hours to 4 hours for salted raw stock and from 24 hours to 10 hours for dried raw stock. At the liming and unhairing processes, however enzyme can be recover a good quality of hair with a good saleable value, recution of sodium sulfide to minimize the waste, the quality of tanned leather will increase, by using 3 % of the enzyme concentration moreover the tensile strength increased from 138,35 kg/cm2 to 209.50 kg/ cm2,while elongation at break degrease from 69.91% to 62.54%. at the bating process, the proteolitic enzyme was the only one substance and it can’t be substituted by other chemicals. At the degreasing process, the use of lipase enzyme will improve the quality of waste effluent, it was due to the application of fat solvent on contional method of tanning. The use 0.02% concentration of collagenase enzyme in vegetable tanning will increase the tanning’s substance absorption efficiency by 98%. Whereas at the waste treatment, the acidophilic fungi might absorb chromium that was liberated from the re-tanning process with 95% affectivity. Immobilized cells were also possible to be applied in effluent waste treatment of leather industry.  Keyword : biotechnology, enzyme, tanning, waste Dalam lingkup yang lebih luas, bioteknologi telah diterapkan dalam industry kulit bertahun-tahun sejak diperkenalkannya enzim. Pada proses penyamakan kulit penggunaan enzim cukup sukses pada beberapa tahapan proses. Pada proses perendaman (soaking) dapat mempercepat waktu perendaman dari 7 jam menjadi 4 jam untuk kulit awet garam dan dari 24 jam menjadi 10 jam untuk kulit awet kering. Pada proses pengapuran dan penghilangan bulu (liming dan unhairing) akan menghasilkan bulu kualitas baik yang mempunyai nilai jual dan mengurangi pengunaan garam sulfide sehingga dapat mengurangi cemaran. Kulit samak yang dihasilkan meningkat kualitas pada penggunaan 3 % ensim, sementara kuat tarik meningkat dari 138,35 kg/cm2 menjadi 209,50 kg/cm2, namun kemuluran turun dari 69,91% menjadi 62,54%. Pada proses pengkikisan protein (bating), enzim protease merupakan satu-satunya bahan bating dan tidak bias digantikan oleh kimia lain. Pada proses penghilangan lemak (degreasing) maka penggunaan enzim lipase dapat mengurangi cemaran akibat bahan pelarut lemak yang digunakan pada cara konvensional. Penggunaan enzim kolagenase sebesar 0,02 % pada proses penyamakan dengan pada cara konvensional. Penggunaan enzim kolagenase sebesar 0,02% pada proses penyamakan dengan samak nabati telah meningkatkan efisiensi penyerapan bahan penyamak sampai 98%. Sedangkan penanganan limbah dengan bioteknologi mengurangi kromium pada proses penyamakan ulang menggunakan jamur asidophilik yang efektifitas mencapai 95%. Penggunaan immobilisasi sel memungkinkan untuk diterapkan pada penanganan limbah industry penyamaan kulit. Kata Kunci : bioteknologi, ensim, penyamakan, limbah.
KLASIFIKASI POTENSI ZAKAT DI LAZISMU DIY MENGGUNAKAN METODE K-NEAREST NEIGHBOR (K-NN) BERBASIS WEB FRAMEWORK Tedy Setyadi; Andri Pranolo; Prayitno Prayitno
Jurnal Sarjana Teknik Informatika Vol 5, No 3 (2017): Oktober
Publisher : Teknik Informatika, Universitas Ahmad Dahlan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12928/jstie.v5i3.12370

Abstract

Zakat berperan untuk mencapai keadilan sosial ekonomi antara orang kaya dan miskin. Saat ini terdapat Lembaga Amil Zakat (LAZ) yang berperan penting dalam pengelolaan dana Zakat, Infaq, dan Shodaqah. Namun ada beberapa faktor kekurangan dalam hal penyaluran dana zakat yaitu siapa yang berhak menerima dana zakat dengan tepat sasaran dan cabang-cabang mana saja yang berpotensi mandiri dalam pengelolaan zakat. Klasifikasi dapat digunakan untuk menilai ketepatan penyaluran zakat dan mengetahui kemandirian tiap-tiap cabang LAZ berdasarkan data-data masa lalu. Data tersebut bisa digunakan untuk menerapkan metode K-NN sehingga dapat mengklasifikasi dana zakat menurut kelasnya.             Penelitian ini dilakukan untuk mengkaji tentang algoritma K-NN dan mengimplementasikan Algoritma K-NN dalam klasifikasi data. Data yang digunakan adalah data penyaluran dana zakat di Lazismu DIY dari tahun 2013 sampai 2015.Data penyaluran zakat dari cabang-cabang LAZ yang telah melalui proses cleaning data, integration data, selection data, transformation data,dananalisis diproses menggunakan metodeK-Nearest Neighbor (K-NN)  untuk  mengklasifikasikan cabang-cabang yang berpotensi membantu perekonomian daerah (mandiri) dan penyaluran dana zakat yang tepat sasaran berdasarkan  tingkat  kemiripan sejumlah nilai  variabel  k. Proses algoritma K-NN di buatmenghasilkanpattern evaluationdandisajikanmelalui knowledge presentationdenganbantuan web framework.             Hasil pengujian dilakukan terhadap 14 cabang Lazismu di DIY menghasilkan tidakada cabang di kelas Super Mandiri, 6 cabang berada dikelas Mandiri, tidakada cabang berada dikelas Cukup Mandiri, dan 8 cabang berada pada kelas Kurang Mandiri. Hasil confusion matrix dengan perbandingan 80:20 dari data uji dan data testing menghasilkan nilai accuracy sebesar 85% dan error-rate sebesar25%. Hasil accuracy>= 85% dikatakan baik dalam klasifikasi tersebut membuktikan bahwa faktor-faktor nilai atribut yang dipilih mendekati nilai significant
Penelitian pengaruh penambahan karet reclaim terhadap sifat- sifat kuat tarik, kemuluran dan volume terkikis kompon karet Prayitno Prayitno
Majalah Kulit, Karet, dan Plastik Vol 5, No 9 (1990): Majalah Barang Kulit, Karet, dan Plastik
Publisher : Center for Leather, Rubber, and Plastic Ministry of Industry, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1232.178 KB) | DOI: 10.20543/mkkp.v5i9.461

Abstract

Reprocessed of wastevulcanized rubber products, known as reclaim rubber, is used as a filler in rubber soles. Uncorrect usage of reclaim rubber in rubber sole manufacturing can decrease the product performance such as as tensile streangth, elongation break and abrasion resistance.       In this experiment, by comparison of 30, 40, 50, 60 and 70 parts of reclaim rubber to the 100 part of natural rubber (RSS) sow that tensile strength decreased to 174.138, 160.118, 140.574, 134.092, and 449,60, 437.20, 426.00, 403.80 and 396.60% nrespectively, whereas abrasion resistance decreased to 0,2491, 0,4781, 0,5267, 0.7909, and mm3 / kgm respectively.
Pemanfaatan trimming kulit pikel sebagai flokulan melalui hidrolisis kolagen menggunakan basa untuk penjernihan air Sugihartono Sugihartono; Sri Sutyasmi; Prayitno Prayitno
Majalah Kulit, Karet, dan Plastik Vol 31, No 1 (2015): Majalah Kulit, Karet, dan Plastik
Publisher : Center for Leather, Rubber, and Plastic Ministry of Industry, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (513.021 KB) | DOI: 10.20543/mkkp.v31i1.221

Abstract

Wastes in the form of skin derivatives from leather tanning industries remain serious problems if not managed properly and quickly, since they can cause environmental pollution. This research aimed at studying the influence of base type and concentration for the hydrolysis of trimmed collagen from pickled sheepskin to the yield and properties of gelatin, as well as the gelatin’s potential as flocculant. The hydrolysis of trimmed collagen from pickled sheepskin was performed using KOH or NaOH solution, each with varied concentrations of 1, 2, 3, and 4% w/v, for 16 hours. The extraction of the resulting gelatin was performed using water (2.5 water part : 1 waste part), at 70-80 oC, for 3 hours. The results show that the yield of gelatin from hydrolysis using KOH (16.50-28.60%) is lower than that using NaOH (23.68-34.42%). The water and fat contents of the resulting gelatin were relatively similar, while the protein content from KOH treatment was higher than that from NaOH treatment. Hydrolysis with KOH 1% and NaOH 1% and 2% resulted in gelatin that can be used as flocculant. Hydrolysis with NaOH 2% was the best treatment to produce gelatin as flocculant.Keywords: pickled sheepskin, trimming waste, hydrolysis, gelatin,  flocculant.ABSTRAKLimbah berupa kulit turunan dari industri penyamakan kulit masih menjadi masalah serius apabila tidak ditangani secara tepat dan cepat, karena dapat menimbulkan pencemaran lingkungan. Penelitian ini bertujuan untuk mempelajari pengaruh jenis dan konsentrasi basa untuk hidrolisis kolagen hasil trimming kulit domba pikel terhadap rendemen dan sifat gelatin serta kemampuannya sebagai flokulan. Hidrolisis kolagen hasil trimming kulit domba pikel dilakukan dengan menggunakan larutan KOH dan NaOH, dengan konsentrasi berturut-turut 1, 2, 3, dan 4% b/v selama 16 jam. Ekstraksi gelatin dilakukan dengan menggunakan air (2,5 bagian air : 1 bagian kulit) pada suhu 70 – 80 oC, selama 3 jam. Hasil penelitian menunjukkan rendemen gelatin hasil hidrolisis menggunakan KOH adalah sebesar 16,5 - 28,60%, lebih rendah dibandingkan dengan menggunakan NaOH, yaitu sebesar 23,68 - 34,42%. Kandungan air dan lemak gelatin relatif sama, sedangkan kandungan protein hasil perlakuan KOH lebih tinggi dari pada NaOH. Sebaliknya, kandungan abu dan pH perlakuan KOH lebih rendah dibandingkan dengan perlakuan NaOH. Hidrolisis dengan KOH 1% dan NaOH 1% serta 2% menghasilkan gelatin yang dapat berfungsi sebagai flokulan. Hidrolisis menggunakan NaOH 2% merupakan perlakuan terbaik untuk menghasilkan gelatin sebagai flokulan.Kata kunci: kulit domba pikel, limbah trimming, hidrolisis, gelatin, flokulan.
Ekstraksi ion krom dalam asam nitrat dengan teknologi membran cair untuk limbah industri penyamakan kulit Dwi Wahini Nurhajati; Prayitno Prayitno; Endro Kismolo
Majalah Kulit, Karet, dan Plastik Vol 15, No 2 (1999): Majalah Barang Kulit, Karet, dan Plastik
Publisher : Center for Leather, Rubber, and Plastic Ministry of Industry, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (2504.551 KB) | DOI: 10.20543/mkkp.v15i2.258

Abstract

The objective of the research was to use of liquid membrane emulsion technique for the extraction of chrom in the nitrate acid solution. The liquid membrane phase as emulsion consists of kerosene as the solvent, sorbitan monooleat (span-80) as the surfactant, trioktil amin, as the carrier, natrium hidroksida as the internal phase. The optimum conditions obtained for making membrane, the liquid membrane phase was consists of organic phase (O), the internal liquid phase (W) with the ratio of O/W = 1, the concentration sorbitan monooleat (span-80) in the membrane phase was 4%(v/v), the optimum time to achieve a emulsion was 5 minutes, the rate of stirring for membrane 8000 rpm. The  optimum conditions obtained for extraction chrom ion as of chrom nitrate  from solution with percentage of liquid membrane extraction used of 97,8% and the percentage of liquid membrane extraction used of 97,8% and the percentage of liquid-liquid extraction of 81,24% were as follow : the concentration of nitric acid in external phase was 3M, the concentration of tri oktil amin in the membrane phase was 5% (v/v), the concentration of natrium hidroksida in internal phase was 1% (v/v), the extraction time was 15 minutes and volume ratio of membrane phase and external phase was 1 : 3. The addition of Fe and Zn ions solution decreased the percent extraction of chrom ion. INTISARI Penelitian ini bertujuan untuk meneliti teknik membran cair dalam ekstraksi krom pada larutan asam nitrat. Fasa membran yang berupa emulsi terdiri dari kerosene sebagai pelarut, sorbitan monooleat (span-80) sebagai surfaktan, tri oktil amin (TOA), sebagai zat pembawa serta natrium hidroksida sebagai fasa internal. Kondisi optimum yang diperoleh untuk pembuatan membrane cair, fasa membran terdiri dari fasa organic (O), fasa internal (W) dengan perbandingan O/W = 1, konsentrasi sorbitan monooleat dalam fasa membran 4%(v/v), waktu optimum pembuatan emulsi 4 menit, kecepatan pengadukan 8000 rpm. Kondisi optimum yang diperoleh untuk mengekstraksi krom dari larutan yang mengandung krom nitrat dengan prosen ekstraksi membran-cair sebesar 97,80% dan proses ekstraksi cair-cair sebesar 81,24% adalah sebagai berikut : konsentrasi asam nitrat dalam fasa eksternal adalah 3M, konsentrasi tri oktil amin dalam fasa membran adalah 5%(v/v), konsentrasi natrium hidroksida, dalam fasa internal 1%(v/v), 1 M dan lamanya waktu ekstraksi ialah 15 menit dan perbandingan  volume fasa membran dan volume fasa eksternal adalah 1 : 3. Penambahan ion ferro dan seng dalam larutan krom akan menurunkan prosen ekstraksi krom
Penelitian penggunaan minarex pertamina sebagai minyak pelunak kompon karet untuk sol sepatu kanvas Sofyan Karani; Prayitno Prayitno; Sri Bandi; Sri Budiasih
Majalah Kulit, Karet, dan Plastik Vol 10, No 19 (1995): Majalah Barang Kulit, Karet, dan Plastik
Publisher : Center for Leather, Rubber, and Plastic Ministry of Industry, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1655.193 KB) | DOI: 10.20543/mkkp.v10i19.436

Abstract

The objective of the research is to use minarex, by product of Pertamina, as a softener in making rubber sole compound for canvas shoes. The formula of the compound applied four kinds of minarex, manely minarex A, B, C and D with variation 2 – 8 phr. The mastication and mixing processes used two roll mill machine and the compound was vulcanized at 150 oC, at the pressure 150 kg/cm2and 10 mnutes curing time. The comformityt of softener, minaret, is excellent and no oil exist to the surface of the vulcanized compound. The property of the vulcanized compound fulfilled all the quality requirements of SNI 0778-89- A and SNI 1844-90-A for canvas shoe rubber sole, except abrasion for sport shoe (max. 1.00 mm3/ kgm compared with the result of the test, 1.52 – 2.35 mm3/kgm). Data analysed proves the to kinds of minarex to influence all properties in rubber compounds. While treatment of minarex to inflience the properties of elongation at break, permanent set and hardness. The type of minarex to influince properties of the tear strength, abrasion and density to rubber compound.    INTISARI Penelitian ini bertujuan untuk menggunakan minarex Pertamina sebagai bahan pelunak dalam pembuatan kompon karet untuk sol sepatu kanvas. Formula kompon menggunakan empat jenis minarex yaitu minarex A, B, C dan D dengan variasi antara 2 – 8 phr. Pencampuran menggunakan giling karet terbuka dan kompon divulkanisasi pada suhu 1500C, tekanan 150 kg/cm2 dan waktu 10 menit. Tingkat kecocokan bahan pelunak minarex sangat baik, tidak terjadi pengeluaran minyak ke permukaan kompon dan vulkanisat kompon. Sifat vulkanisat memenuhi semua persyaratan mutu dalam SNI 0778-89-A dan SNI 1844-99-A untuk sol karet sepatu kanvas, kecuali syarat mutu ketahanan kikis sol sepatu untuk olah raga maks. 1,00 mm3 / kgm dibandingkan dengan hasil uji kikis vulkanisat yaitu antara 1,52 – 2,35 mm3 /kgm. Hasil analisa data uji menunjukkan jenis minrex mempengaruhi semua sifat fisis kompon yang di ujikan. Sedangkan sifat perlakuan minarex mempengaruhi perpanjangan putus, perpanjangan tetap dan kekerasan. Type minarex mempengaruhi ketahanan jenis dan ketahanan sobek  kompon karet.   
Penelitian penentuan konstanta saturasi (Ks) pada rbc unit Prayitno Prayitno
Majalah Kulit, Karet, dan Plastik Vol 7, No 12-13 (1992): Majalah Barang Kulit, Karet, dan Plastik
Publisher : Center for Leather, Rubber, and Plastic Ministry of Industry, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (803.175 KB) | DOI: 10.20543/mkkp.v7i12-13.478

Abstract

Kinetic of Rotating Biological Contractor have been investigated by manu researchers. In general the model emploued either saturation kinetic (following Monod equation) or first order kinetic to describe substrate removal. In this experiment, saturation kinetic model was used to find out the saturation constant of the RBC unit. The influent fed into the unit was synthetic waste water with glucose as organic carbon sources. The flow was maintained constant at 20.4 1/d and COD influent resulted the saturation constant (Ks) 11.17 mg/I with 20 hours of detention time.
Student autonomy in doing the task and information service’s Nurhaidah Napitupulu; Prayitno Prayitno; Marjohan Marjohan
International Conferences on Educational, Social Sciences and Technology
Publisher : Fakultas Ilmu Pendidikan UNP

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29210/201817

Abstract

Many students did not have autonomy in doing the task which teachers give. The research was aimed to describe the quality of students autonomy in doing the school tasks and the students opinion about the quality of information service implementation to improve student autonomy as the realization of the guidance and counseling services function. This research used quantitative method with descriptive statictics. The population were national and private junior high school which is on grade A in Padang City. The samples was 120 students. Data were analyzed by using statictics technique.The result shows that the quality of student autonomy in doing the task and the students opinion about the quality of information service by counselor to develop students autonomy in doing the school task was in high category, and the quality of student autonomy and the quality of the information service in the two school was in significant correlation.
Plastik film sebagai pengemas makanan asinan jahe untuk ekspor Prayitno Prayitno; Any Setyaningsih
Majalah Kulit, Karet, dan Plastik Vol 11, No 21 (1996): Majalah Barang Kulit, Karet, dan Plastik
Publisher : Center for Leather, Rubber, and Plastic Ministry of Industry, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (726.272 KB) | DOI: 10.20543/mkkp.v11i21.389

Abstract

One of the plastic material which is usually used for packaging is polyethylene. That plastic has a good performance for plasticity, chemicals resistence, flexibility and no toxic subtances, therefore, this is suitable for good packaging. One of the use plastic film for packaging is for packing of salted ginger for export purpose. Research in physical properties of the salted ginger packaging shows that plastic film packaging has a weakness in the tearing strength properties and some leaking caused by the unproper sealing during the process. INTISARI Salah satu bahan plastik yang banyak digunakan untuk bahan pengemasan adalah bahan plastik polyethylena. Bahan tersebut mempunyai sifat yang baik dalam keuletan, ketahanan terhadap bahan kimia serta fleksibilitasnya dan tidak mengandung bahan-bahan yang toxic sehingga sangat cocok untuk pengemas makanan. Penggunaan kantong plastik film polyethylena untuk mengemas makanan diantaranya untuk mengemas bahan setengah jadi asinan jahe untuk keperluan ekspor. Dari hasil penelitian sifat fisis kantong plastik untuk kemasan asinan jahe masih dijumpai adanya kelemahan pada bahan plastiknya, yaitu pada kekuatan sobeknya dan kebocoran-kebocoran yang sering terjadi yang disebabkan kurang sempurnanya dalam pembuatan kantong plastik, terutama dalam proses lekat panas.