Enhancement of soil physico-chemical properties post compost application: Optimization using Response Surface Methodology comprehending Central Composite Design

2021 ◽  
Vol 289 ◽  
pp. 112461
Author(s):  
Payal Mazumder ◽  
Akhil PM ◽  
Jyoti ◽  
Meena Khwairakpam ◽  
Umesh Mishra ◽  
...  
2015 ◽  
Vol 9 (11) ◽  
pp. 68
Author(s):  
Widayat Widayat ◽  
Hadiyanto Hadiyanto ◽  
Bambang Cahyono ◽  
Ngadiwiyana Ngadiwiyana

The objective of this research was to obtain optimum condition of eugenol production from clove oil using a central composite design method. The main process occured in the eugenol production was saphonification and neutralization processes. In order to optimize these processes, the ratio of NaOH/clove oil and temperature were studied as design variables i.e. ratio of NaOH/clove oil=1:2.5-1:3.5 while temperature was varied between 40 and 60oC. The yield of eugenol was considered as the main response in of this experiment. The result showed that the optimum condition was achieved when the temperature and the ratio of NaOH/clove oil were 50oC and 2.75:1, respectively and the yield was 39.17%.<br />


2015 ◽  
Vol 10 (3) ◽  
Author(s):  
Febrina Dwi Putri ◽  
Zuchra Helwani ◽  
Drastinawati Drastinawati

Biodiesel merupakan sumber bahan bakar alternatif yang bisa dihasilkan dari minyak nabati melalui transesterifikasi dengan metanol. Sawit Off-grade merupakan salah satu sumber minyak nabati yang mempunyai potensi untuk digunakan sebagai bahan dasar produksi biodiesel. Reaksi transesterifikasi dilangsungkan dengan bantuan katalis CaO dari cangkang telur yang dikalsinasi pada suhu 900ºC selama 2 jam. Tujuan dari penelitian ini adalah untuk memproduksi biodiesel dari minyak sawit off-grade melalui reaksi dua-tahap, melihat performa katalis Cao terhadap reaksi transesterifikasi, serta mempelajari pengaruh temperatur reaksi, rasio mol minyak:metanol dan konsentrasi katalis terhadap yield biodiesel pada reaksi transesterifikasi. Esterifikasi dilakukan pada suhu 60°C dengan perbandingan mol minyak:metanol 1:12 menggunakan 1%wt katalis H2SO4. Asam lemak bebas (ALB) tereduksi dari 16,18% menjadi 0,6%. Reaksi transesterifikasi dilakukan dengan variasi perbandingan mol minyak:metanol 1:7, 1:9, 1:11, konsentrasi katalis 2%wt, 4%wt, 6%wt, serta suhu reaksi pada 50ºC, 60ºC, 70ºC selama 2 jam. Data yang diperoleh diproses dengan menggunakan response surface methodology (RSM), sedangkan jumlah eksperimen ditentukan dengan central composite design (CCD). Yield yang diperoleh pada penelitian ini yaitu sebanyak 62,30%-87,41%. Yield optimum dihasilkan pada reaksi dengan suhu 70ºC menggunakan minyak:metanol dengan perbandingan 1:11 dan katalis CaO 2%wt. Kondisi proses yang berpengaruh terhadap yield biodiesel adalah suhu reaksi, perbandingan mol minyak:metanol, serta interaksi antara suhu dengan perbandingan mol minyak:metanol. Akan tetapi tidak ditemukan adanya pengaruh signifikan konsentrasi katalis terhadap yield biodiesel.


2019 ◽  
Vol 7 (2) ◽  
pp. 139-147
Author(s):  
Ida Ayu Widhiantari ◽  
Sandra Sandra ◽  
Gunomo Djoyowasito

Selama kegiatan transportasi buah tomat dapat mengalami kerusakan akibat adanya frekuensi getaran yang berasal dari mesin transportasi dan juga lama waktu kegiatan transportasi. Adanya getaran selama proses transportasi buah tomat dapat mempengaruhi perubahan tekstur buah tomat. Optimasi dilakukan dalam penelitian ini dengan tujuan untuk memperoleh mutu buah tomat yang optimal setelah dilakukan simulasi transportasi. Optimasi dilakukan dengan menggunakan Response Surface Methodology (RSM) central composite design (CCD) dengan dua variabel bebas yaitu frekuensi getaran (3 Hz, 6HZ, dan 9Hz) dan lama waktu penggetaran (120, 150, dan 180 menit) serta tekstur buah tomat sebagai respon. Kondisi optimum diperoleh pada frekuensi getaran  2,33 Hz dan waktu simulasi transportasi 133,42 menit dengan nilai tekstur optimum buah tomat yaitu 0,147768 dengan nilai desirability sebesar 0,928.    


2019 ◽  
Vol 62 (1) ◽  
pp. 157-166
Author(s):  
Luxin Xie ◽  
Jun Wang ◽  
Shaoming Cheng ◽  
Jinbing Hu

Abstract. Leaf stripping and top breaking are the key procedures in whole-stalk sugarcane harvesting. In this study, a whole-stalk operating system after sugarcane base cutting was developed and tested to improve the leafy trash cleaning performance and adaptability of a whole-stalk harvester. A leaf shredding procedure was proposed before leaf stripping, and an anti-float top breaking device was developed for breaking cane tops. The rotational speeds of the leaf shredding (RL), leaf stripping (RS), and top breaking (RT) rollers were regarded as experimental factors, and the leafy trash content (including leaves, leaf sheaths, and tops in this study), top breaking rate, abrasion rate, and non-fracture rate of the middle or bottom parts were selected as indices. Central composite design combined with response surface methodology and comprehensive evaluation method were employed to conduct experiments and explore the interaction effects of factors on indices. The optimal operating parameters were nonlinearly optimized and determined to be RL of 512.9 rpm, RS of 418.8 rpm, and RT of 307.0 rpm. Under these conditions, the predicted values of leafy trash content, top breaking rate, abrasion rate, and non-fracture rate were 4.98%, 88.39%, 5.19%, and 96.21%, respectively. Verification experiments indicated that the observed values were in agreement with the predicted values. Results suggested that the leaf shredding device and anti-float top breaking device developed in this study were effective for improving the leafy trash cleaning performance and adaptability of the whole-stalk operating system, and there was a good potential for performance improvement of whole-stalk sugarcane harvesters. Keywords: Central composite design, Leaf shredding, Leaf stripping, Response surface methodology, Top breaking, Whole-stalk harvester.


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