Peningkatan Kerapatan Kayu Samama Melalui Pre-kompresi Asam Sitrat (Density Improvement of Samama Wood by Pre-compression of Citric Acid)

2021 ◽  
Vol 17 (2) ◽  
pp. 122-133
Author(s):  
Azis Rumbaremata ◽  
Tekat D Cahyono ◽  
Teguh Darmawan ◽  
Sukma S Kusumah ◽  
Fazhar Akbar ◽  
...  
Keyword(s):  
Citric Acid ◽  
Acid Concentration ◽  
Aluminum Foil ◽  
Dry Density ◽  
Citric Acid Concentration ◽  
Pressing Time ◽  
R Ratio ◽  
Permanent Fixation ◽  
Water Saturated ◽  
Temperature Time

Samama wood (Anthocephalus macrophyllus (Roxb.) Havil.) is a potential fast-growing species of Sulawesi and Maluku. This study aimed to increase the density of the wood through citric acid pre-compression. The temperature/time pressing formula and the optimal concentration of citric acid for fixation were also determined. Water saturated samples of (5x5x4) cm3 (L = longitudinal x T = tangential x R = radial) were pre-compressed at 100 °C for one hour to reach drying set. Subsquently, the samples were soaked for 4 hours in a citric acid solution of 5% and 10% concentration, drained and wrapped in aluminum foil before re-pressed at 180 °C for 10, 20, 30, 40, 50, and 60 minutes. Fixation was measured by soaking the samples into water for 24 hours at room temperature. The results showed that the moisture contents at fiber saturation point ranged from 33.15-33.94%, with density of 0.46 g cm-3 and oven dry density of 0.37 g cm-3. The L, T, and R shrinkages were 0.18-0.20%, 4.13-4.14%, and 2.53-3.10%, respectively; while the T/R ratio was 1.33-1.63%. Pre-compression can only be done at a compression target of 25% with compression level of 19.57-20.01%. Pre-compression increased the oven dry density of 17.11-20.13% to 0.44-0.45 g cm-3. After thickness recovery, the weight of the oven dried samples increased by 1.79-2.72% at the 5% citric acid concentration and by 12.04-15.25% at the 10% citric acid concentration.  Permanent fixation achieved at 180 °C for 50 minutes pressing time with 10% citric acid concentration.

scholarly journals Optimization of Betalain Pigments Extraction Using Beetroot by-Products as a Valuable Source

Inventions ◽  
2021 ◽  
Vol 6 (3) ◽  
pp. 50
Author(s):  
Silvia Lazăr (Mistrianu) ◽  
Oana Emilia Constantin ◽  
Nicoleta Stănciuc ◽  
Iuliana Aprodu ◽  
Constantin Croitoru ◽  
...  
Keyword(s):  
Citric Acid ◽  
Acid Concentration ◽  
Ethanol Concentration ◽  
Extraction Process ◽  
Extraction Time ◽  
Quadratic Model ◽  
Citric Acid Concentration ◽  
Operating Variables ◽  
Conventional Solvent Extraction ◽  
Optimized Conditions

(1) Background: This study is designed to extract the bioactive compounds from beetroot peel for future use in the food industry. (2) Methods: Spectrophotometry techniques analyzed the effect of conventional solvent extraction on betalains and polyphenolic compounds from beetroot peels. Several treatments by varying for factors (ethanol and citric acid concentration, temperature, and time) were applied to the beetroot peel samples. A Central Composite Design (CCD) has been used to investigate the effect of the extraction parameters on the extraction steps and optimize the betalains and total polyphenols extraction from beetroot. A quadratic model was suggested for all the parameters analyzed and used. (3) Results: The maximum and minimum variables investigated in the experimental plan in the coded form are citric acid concentration (0.10–1.5%), ethanol concentration (10–50%), operating temperature (20–60 °C), and extraction time (15–50 min). The experimental design revealed variation in betalain content ranging from 0.29 to 1.44 mg/g DW, and the yield of polyphenolic varied from 1.64 to 2.74 mg/g DW. The optimized conditions for the maximum recovery of betalains and phenols were citric acid concentration 1.5%, ethanol concentration 50%, temperature 52.52 °C, and extraction time 49.9 min. (4) Conclusions: Overall, it can be noted that the extraction process can be improved by adjusting operating variables in order to maximize the model responses.

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.

scholarly journals The significance of sour cherry in iron supplementation

2015 ◽  
pp. 101-104
Author(s):  
Andrea Nemes ◽  
Edina Baranyai ◽  
Judit Remenyik
Keyword(s):  
Citric Acid ◽  
Vitamin C ◽  
Acid Concentration ◽  
Iron Content ◽  
Iron Supplementation ◽  
Iron Concentration ◽  
Sour Cherry ◽  
Citric Acid Concentration ◽  
Icp Ms

The iron concentration of ’Csengődi csokros’, ’Debreceni- and ’Érdi bőtermő’ , ‘Éva’, ’Kántorjánosi’ ,’Petri’ and the ’Újfehértói fürtös’ cultivars was determined by ICP-MS. Furthermore the Vitamin C, L-Malis acid and Citric acid concentration of samples were measured. Our results show that large amount Fe2+ (average 20.5 mg kg-1) accumulates in the pulp of sour cherry. Besides, the concentration of Vitamin C, L-Malis acid, that increase the absorption of iron, are high. Based on these results, the sour cherry and the products of sour cherry play an important role in the forming of iron content in body.

Sign in / Sign up

Export Citation Format

Share Document