EFEKTIFITAS SISTEM FERTIGASI KENDI PADA TANAMAN LADA PERDU (Piper
nigrum Linn)
Effectiveness of Pitcher Fertigation System on Bushes Pepper Crops
Hermantoro, B.I. Setiawan, S. Hardjoamidjojo, dan M.H. Bintoro
1~7
OPTIMASI PARAMETER TANK MODEL
Optimation of Tank Model’s Parameters
Budi I. Setiawan
8~20
TORSI PEMOTONGAN DAN EFEK HEMBUSAN DARI MODEL PISAU MIRING (SLANTED BLADE) UNTUK MESIN PEMOTONG RUMPUT TIPE ROTARI
Cutting Torque And Blowing Effect Of Slanted Blade Model For Rotary-Type Mower
I Nengah Suastawa, Radite Praeko Agus Setiawan, Prima Sanjaya
21~31
TEKNIK REKAYASA PEMADATAN KAYU II : SIFAT FISIK DAN MEKANIK KAYU AGATIS (Agathis lorantifolia salisb.) TERPADATKAN DALAM KONSTRUKSI BANGUNAN KAYU
Sulistyono, Naresworo Nugroho, Surjono Surjokusumo
32~45
PENGARUH ARUS LUARAN LRC PADA METODA Q-METER TERHADAP HASIL PENGUKURAN NILAI SIFAT DIELEKTRIK DI SEKITAR FREKUENSI RADIO
The Influence Of Lrc Current From The Q-Meter To The Measured Value Of Dielectric Properties Within Radio Frequency Range
Harmen, Armansyah H. Tambunan
46~58
KARAKTERISTIK PEMBEKUAN VAKUM PULP MARKISA
Vacuum Freezing Characteristics Of Passion Fruit
Armansyah H. Tambunan, Ainun Rohanah, Y. Aris Purwanto
59~67
ANALISIS DISTRIBUSI SUHU DAN KECEPATAN ALIRAN UDARA DALAM RUANG PENGERING BERENERGI SURYA MENGGUNAKAN CFD
Analysis Of Temperature And Air Flow Distribution In Solar Dryer Using CFD
Dyah W., L.O. Nelwan, Kamaruddin, A., A. Indra S.
EFEKTIFITAS SISTEM FERTIGASI KENDI PADA TANAMAN LADA PERDU
(Piper nigrum Linn)
(Effectiveness of Pitcher Fertigation System on Bushes Pepper Crops)
Hermantoro1, B.I. Setiawan2, S. Hardjoamidjojo2, dan M.H. Bintoro2 Abstract
The successful application of pitcher irrigation system has motivated to investigate the pitcher as a fertigation system. The experiment was conducted at Leuwikopo Experiment Station, Agricultural Engineering Department, Bogor Agriculture University. The main objective of this study is to study the effectiveness of pitcher fertigation system on bushes pepper crops. The result shows that the pitcher wall is capable to release NPK solution. Diffusion rate of fertilizer solution was measured as affected by the concentration inside and outside of the pitcher. The soil moisture distribution in the soil is sufficient to transport the solution available for crops development. Concentration of Phosphate (P) and Potassium (K) decrease laterally and the Nitrogen (N) tends to accumulate homogeneously in moist part around the pitcher.
Key words : Irigasi, Fertigasi, Kendi, Difusi.
1~7
1
Mahasiswa Program Pascasarjana IPB 2
OPTIMASI PARAMETER TANK MODEL Optimation of Tank Model’s Parameters
Budi I. Setiawan
Jurusan Teknik Pertanian, Fakultas Teknologi Pertanian Institut Pertanian Bogor
PO BOX 220, Bogor 16002 E-mal: [email protected]
Abstrac
Tank Model is one of hydrological models to analize characteristics of river flow. The model can give information of water availability and be used to predict flood occurences. As it is commonplace, this model needs calibration, and it is usually done by setting the embodied parameters. In form of Standard Tank Model, the number of parameters accounts to 12. Many optimation methods have been recognized but so far there is no single method available for general application. This paper introduces an optimation technique to determine the parameters with taking into account conformity to water balance in addition to best-fitting. Here, two data from Cidanau and Terauchi Watershed were used for clarification, which show that this optimation technique gained fast and accurate results. This technique has been made available to use in form of an application software and openly possible to accommodate the other forms of Tank Model.
Keywords : Hydroligical Model, Tank Model, Parameter, Optimation, Application
Program.
TORSI PEMOTONGAN DAN EFEK HEMBUSAN DARI MODEL PISAU MIRING (SLANTED BLADE) UNTUK MESIN PEMOTONG RUMPUT
TIPE ROTARI
(Cutting Torque and Blowing Effect of Slanted Blade Model for Rotary-Type Mower)
I Nengah Suastawa1, Radite Praeko Agus Setiawan1, dan Prima Sanjaya2 Abstract
Rotary-type mower is commonly used for cutting turfgrass as a part of landscape maintenance. Cutting torque and quality of turf surface resulted by cutting are two important factors that have to be considered in designing rotary-type mower blades. The objectives of this research are to design and build a slanted blade model, and to study its cutting torque, blowing effect, and friction between blades and turf surface on a several rotational speeds, slant angles and blade types. The blade model was tested on a specially designed turf-bin test apparatus.
Results of laboratory test on the blade model showed that the cutting torque was influenced by its rotating speed. The biggest cutting torque needed to mow the grass was 0.659 Nm given by the model with slant angle of 15° with rotating speed of 2800 rpm, and the smallest was 0.073 Nm given by the model with slant angle of 5° with rotating speed of 1960 rpm. The slanted blade model resulted a blowing effect that was able to carry clippings into the collector. Most of the clippings were collected in the collector. The highest collected clippings was 96.94% given by the model with slant angle of 5° and rotating speed of 2800 rpm, and the lowest was 24.76% given by the model and slant angle of 5° with rotating speed of 2700 rpm. The highest percentage of torque due to friction between blades and turf surface was 40.1% given by the model with slant angle of 10° and rotating speed of 1960 rpm, and the lowest was 3.9% given by the model with slant angle of 10° and rotating speed of 2800 rpm.
Keywords : Mower, rotary, blade, turf, grass
21~31
1
Staf Pengajar Jurusan Teknik Pertanian, Fakultas Teknologi Pertanian IPB 2
TEKNIK REKAYASA PEMADATAN KAYU II :
Sifat Fisik dan Mekanik Kayu Agatis (Agathis lorantifolia Salisb.) Terpadatkan dalam Konstruksi Bangunan Kayu
Sulistyono1, Naresworo Nugroho2 dan Surjono Surjokusumo2 Abstract
Pemadatan kayu dapat dilakukan dengan 2 langkah utama, yaitu perlakuan perendaman, perebusan dan pengukusan agar kayu bersifat plastis dan perlakuan pemadatan pada arah tegak lurus serat. Proses plastisasi dan pemadatan kayu yang sesuai dapat meningkatkan sifat fisik dan sifat mekanik kayu terpadatkan dan berkualitas tinggi. Kualitas yang dimaksud adalah kemudahan proses pemadatan, stabilitas dimensi, keseragaman dan peningkatan kekuatan papan kayu, kehalusan corak permukaan papan dan fiksasi permanen.
Pemadatan kayu agatis dilakukan dengan 3 (tiga) metode plastisasi yaitu : 1.Perendaman sampai jenuh air, 2. Perebusan sampai suhu 120 oC, dan 3. Pengukusan
sampai suhu 120 oC. Suhu kempa bervariasi mulai dari 125 o, 150 o, 175 o dan 200 o
Hasilnya menunjukkan bahwa pemadatan kayu berpengaruh terhadap sifat fisik dan mekanik kayu. Hasilnya sangat nyata pada kerapatan dan berat jenis yang meningkat hampir dua kali lipat. Sifat mekanik (MOE, MOR, Tekan Sejajar Serat, Kekerasan, Keteguhan Geser, dan Daya Dukung Baut) rata-rata meningkat 2 kali lipat dibanding kayu solidnya.
Hasil pemadatan kayu ini dapat digunakan untuk bahan lantai, interior, handtools, moulding dan furniture serta aplikasi untuk konstruksi struktural.
32~45
1
Staf Pengajar Fakultas Kehutanan, Universitas Winaya Mukti 2
PENGARUH ARUS LUARAN LRC PADA METODA Q-METER TERHADAP HASIL PENGUKURAN NILAI SIFAT DIELEKTRIK DI
SEKITAR FREKUENSI RADIO
The Influence of LRC Current from the Q-Meter to the Measured Value of Dielectric Properties Within Radio Frequency Range
Harmen1, Armansyah H. Tambunan2 Abstrak
Various measuring method of dielectric properties has been studied by researchers, one of wich is the Booton 160-A Q-meter operated within the radio frequency range. Determination of dielectric properties by the Q-meter is accomplised through the measurement of voltage (Q) and capacitance (C) of the LRC, which is naturally in the form of alternating current (AC). Measurement of the AC voltage by a voltmeter shows instability of the measured value, while using an osciloscope require an expensive apparatus. The problem seems can be solved by convertion of the LRC output from alternating to direct current. This paper is to study the influence of LRC output to the measured dielectric properties, by converting the output from alternating to direct current.
The experiment showed that convertion of the LRC output into direct current can provide stability of the measurement. Comparison to the theoretical trend showed that dielectric properties determined by using the DC output are more reliable than that by the AC output.
Keywords : dielectric constant, dielectric loss factor, radio frequency, direct current,
alternating current.
46~58
1
Staf Pengajar Jurusan Teknologi Pertanian, Politeknik Pertanian Negeri, Bandar Lampung 2
KARAKTERISTIK PEMBEKUAN VAKUM PULP MARKISA
Vacuum Freezing Characteristics of Passion Fruit
Armansyah H. Tambunan1, Ainun Rohanah2, dan Y. Aris Purwanto1 Abstract
Pemilihan metode pembekuan merupakan salah satu aspek yang penting, khususnya dari sisi keteknikan. Pembandingan karakteristik pembekuan dan mutu produk yang dibekukan dengan berbagai metoda dapat digunakan untuk keperluan tersebut. Tujuan penelitian ini adalah untuk melakukan perbandingan karakteristik pembekuan antara metoda pembekuan vakum dan metoda pembekuan lempeng sentuh. Bahan yang dibekukan adalah pulp markisa. Parameter banding yang digunakan adalah profil dan sebaran suhu bahan, laju pembekuan, konsumsi energi dan parameter mutu seperti warna, kadar air, kandungan protein dan kandungan vitamin C.
Hasil penelitian menunjukkan bahwa pembekuan vakum menghasilkan profil dan sebaran suhu bahan yang lebih seragam, laju pembekuan yang lebih cepat, serta dapat mempertahankan kandungan protein dan warna lebih baik dibandingkan dengan pembekuan lempeng sentuh. Akan tetapi, kadar air dan kandungan vitamin C bahan setelah pembekuan vekum mengalami penurunan yang lebih besar, disamping konsumsi energi yang lebih tinggi.
Kata kunci : pembekuan vakum, pembekuan lempeng sentuh, puplp markisa, profil
suhu, laju pembekuan, parameter mutu, konsumsi energi
59~67
1
Staf Pengajar Jurusan Teknik Pertanian, Fateta IPB 2
ANALISIS DISTRIBUSI SUHU DAN KECEPATAN ALIRAN UDARA DALAM RUANG PENGERING BERENERGI SURYA MENGGUNAKAN
CFD
(Analysis of Temperature and Air Flow Distribution in Solar Dryer Using CFD) Dyah W.1, L.O. Nelwan1, Kamaruddin, A.1 dan A. Indra S.2
Abstract
Solar drying is one of alternative drying method for various agricultural products using renewable energy resources. There is a significant problem i.e. improper uniformity of temperature and air flow in addition to the relatively low average temperature. This generates a non-uniformity of moisture content of the products being dried. The uniformity of these variables is determined by airflow pattern inside the drying room. Therefore, airflow distribution has to be considered in designing solar dryer, particularly that in form of tray drying.
It is important to build mathematical models in designing a system, in order to evaluate the performance of the system without expensive or trial and error experimentation. The objective of this study is to analize airflow and heat transfer in a solar dryer using computational fluid dynamics (CFD) and finite volume for temperature as well as airflow distribution for various positions of fan.
A physical model of solar dryer is designed in order to obtain temperature and air flow velocity, and to be utilized as comparison. Validation between data and calculation of velocity on 64 measurement points has R2 of 89%. Both the
experiment and simulation show a relatively more uniform air temperature distribution than that of airflow velocity. Consequently, the air flow velocity becomes a critical factor in designing inlet and outlet position. Simulation of upper inlet and lower outlet show a more appropriate result than lower inlet- upper outlet.
Keywords : Temperature distribution, airflow, velocity, solar dryer, CFD
68~76
1 Laboratorium Energi dan Elektrifikasi Pertanian, Jurusan Teknik Pertanian, Fateta IPB dan CREATA-LP IPB, Bogor
2
