scholarly journals Optimization of electrospinning process of poly(vinyl alcohol) via response surface methodology (RSM) based on the central composite design

2014 ◽  
Vol 3 (3) ◽  
pp. 175-182 ◽  
Author(s):  
Mina Yazdanpanah ◽  
MohammadReza Khanmohammadi ◽  
Ruhollah Mehdinavaz Aghdam ◽  
Keyvan Shabani ◽  
Masoud Rajabi
Keyword(s):  
Response Surface Methodology ◽  
Central Composite Design ◽  
Response Surface ◽  
Vinyl Alcohol ◽  
Electrospinning Process ◽  
Poly Vinyl Alcohol ◽  
Central Composite

scholarly journals Optimization of Eugenol Extraction from Clove Oil using Response Surface Methodology

2015 ◽  
Vol 9 (11) ◽  
pp. 68
Author(s):  
Widayat Widayat ◽  
Hadiyanto Hadiyanto ◽  
Bambang Cahyono ◽  
Ngadiwiyana Ngadiwiyana
Keyword(s):  
Response Surface Methodology ◽  
Optimum Condition ◽  
Central Composite Design ◽  
Response Surface ◽  
Design Method ◽  
Main Process ◽  
Clove Oil ◽  
Design Variables ◽  
Central Composite

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 />

scholarly journals Pembuatan Biodiesel dari Minyak Sawit Off-Grade Menggunakan Katalis CaO Melalui Proses Dua Tahap

2015 ◽  
Vol 10 (3) ◽  
Author(s):  
Febrina Dwi Putri ◽  
Zuchra Helwani ◽  
Drastinawati Drastinawati
Keyword(s):  
Response Surface Methodology ◽  
Central Composite Design ◽  
Response Surface ◽  
Central Composite

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.

scholarly journals OPTIMASI TEKSTUR BUAH TOMAT SETELAH SIMULASI TRANSPORTASI MENGGUNAKAN RESPON SURFACE METODOLOGY (RSM)

2019 ◽  
Vol 7 (2) ◽  
pp. 139-147
Author(s):  
Ida Ayu Widhiantari ◽  
Sandra Sandra ◽  
Gunomo Djoyowasito
Keyword(s):  
Response Surface Methodology ◽  
Central Composite Design ◽  
Response Surface ◽  
Central Composite

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.    

scholarly journals Development of poly(vinyl alcohol)-based membranes by the response surface methodology for environmental applications

2020 ◽  
Vol 24 ◽  
pp. e5
Author(s):  
Juliana Zanol Merck ◽  
Camila Suliani Raota ◽  
Jocelei Duarte ◽  
Camila Baldasso ◽  
Janaina Da Silva Crespo ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Citric Acid ◽  
Response Surface ◽  
Acid Concentration ◽  
Vinyl Alcohol ◽  
Membrane Preparation ◽  
Poly Vinyl Alcohol ◽  
Esterification Reaction ◽  
Citric Acid Concentration ◽  
Ft Ir

The pollution of hydric sources by pharmaceuticals is an issue in many countries, particularly in Brazil. The presence of these substances causes deleterious effects on the environment and human health. One of the main sources of this contamination is domestic sewage, due to the expressive amount of medicines released in their unaltered form. Unfortunately, traditional wastewater treatment is not effective for the removal of pharmaceuticals and, for this reason, membrane technology is an attractive alternative to overcome this issue. In this regard, hydrophilic polymers, such as poly(vinyl alcohol) (PVA), are the most suitable. However, their high affinity with water causes intense swelling, leading to severe modifications in the membrane properties. In view of all these facts, the present work evaluated the swelling of PVA-based membranes, with the aim of finding the membrane preparation method that has the lowest swelling, thereby providing the most suitable characteristics for pharmaceutical removal from wastewater. The membranes were prepared by the casting of a polymeric solution, with PVA as a basis polymer, citric acid as a crosslink agent and glycerol and silver nanoparticles as performance additives. The process optimization was performed using a design of experiments with posterior analysis by the response surface methodology (RSM). The RSM assessed the effect on the membrane swelling of the factors, including citric acid concentration and the time and temperature of crosslinking. The membrane characterization was performed by Fourier-transform infrared (FT-IR) spectroscopy, scanning electron microscopy coupled with a field emission gun (SEM-FEG) and water contact angle (WCA) measurements. Overall, the condition that showed the lowest swelling was obtained with 10% of citric acid and crosslinking for 4 h at 130 °C. Under these conditions, the membrane had a mass swelling of 42% and a dimensional swelling of 24%. Additionally, our statistical analysis revealed that the factors with the dominant effects were the citric acid concentration and the temperature of crosslinking. The FT-IR analysis suggested that the crosslinking occurred by an esterification reaction, as showed by the stretching frequencies of C=O at 1710 cm-1 and ester C-O at 1230 cm-1. Moreover, the SEM-FEG images revealed a smooth and flat surface and a dense cross section with a thickness of ~113 μm. Concerning the WCA, the angle was at ~80°, which is characteristic of hydrophilic materials. Finally, the data suggested that it is possible to optimize the membrane preparation process with adequate properties so that it can be subsequently applied to the removal of pharmaceuticals from hospital wastewater.

Optimization of a Whole-Stalk Operating System after Sugarcane Base Cutting

2019 ◽  
Vol 62 (1) ◽  
pp. 157-166
Author(s):  
Luxin Xie ◽  
Jun Wang ◽  
Shaoming Cheng ◽  
Jinbing Hu
Keyword(s):  
Operating System ◽  
Response Surface Methodology ◽  
Central Composite Design ◽  
Response Surface ◽  
Fracture Rate ◽  
Cleaning Performance ◽  
Abrasion Rate ◽  
Leaf Stripping ◽  
Predicted Values ◽  
Central Composite

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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