scholarly journals Cassava Starch-Based Composite Reinforced with Coconut Mesocarpfibers: Analysis of Physicochemical Stability

2021 ◽  
Vol 06 (11) ◽  
Author(s):  
Ahmed Doumbia ◽  
Keyword(s):  
Stability Analysis ◽  
Cassava Starch ◽  
Basic Solution ◽  
Distilled Water ◽  
Atmospheric Conditions ◽  
Saline Environment ◽  
Mass Losses ◽  
Physicochemical Stability ◽  
Loss Of Mass

In one of our previous articles, we developed a cassava starch material reinforced with coconut mesocarpfibers. Its properties have been evaluated. It appears that the behavior of the composite depends on the atmospheric conditions of exposure. The purpose of this work is to do a more in-depth physicochemical stability analysis. To do this, identical samples were exposed in different chemical environments: basic, saline, acidic and distilled water. The mass losses are measured after 75 days of immersion in the different solutions in three cases: films without addition of lime and fibers, film with the presence of lime and without reinforcements, and finally the composite with lime and fibers. We observe that, in all cases, the loss of mass decreases with the addition of lime and fibers. However, in the basic solution, this decrease is greater (53.4%) while it remains acceptable in a saline environment (1.1%). In short, this material can be used for several applications in the field of packaging such as the preservation of dry salty products.

scholarly journals Revestimentos à base de amido na conservação de mangas Tommy Atkins associados a duas fontes de cálcio e a um agente oxidante em ambiente refrigerado

2018 ◽  
Vol 1 (42) ◽  
pp. 102
Author(s):  
Alan Ferreira de França ◽  
Iranilson Silva dos Santos ◽  
Júlio Gomes Júnior ◽  
José Eldo Costa ◽  
Alex Danilo Monte de Andrade ◽  
...  
Keyword(s):  
Cassava Starch ◽  
Edible Film ◽  
Maturation Stage ◽  
Refrigerated Storage ◽  
Oxidizing Agent ◽  
Coating Application ◽  
Film Coatings ◽  
Tukey Test ◽  
Calcium Propionate ◽  
Loss Of Mass

<p>The objective of this work was to evaluate the potential of conservation post-harvest starch-based edible film coatings manioc on ‘Tommy Atkins’ mangoes under refrigerated storage. We used fruit from a market in Natal / RN, respecting maturation stage “de vez”. After that the mangoes were taken to the Laboratory of Soils and Plants of the Agricultural School of Jundiaí - EAJ, where they were selected, aiming at the standardization of color, size and weight. The experimental design was completely randomized, in a factorial scheme of 5 x 6 type, corresponding to different treatments of the fruit (without coating application; edible film spraying based on cassava starch; fruit spraying with edible film based on manioc starch + calcium chloride, fruit spraying with edible film based on manioc starch + calcium propionate, fruit spraying with manioc starch + potassium permanganate) in six periods (0, 5, 10, 15, 20, 25 days) in a refrigerated environment (12 ± 2, 85% RH ± 5), and four replicates. The results were submitted to analysis of variance, the means of comparison was done by the Tukey test (5% probability). It was verified that the treatments used were superior to the control from the 15th day of storage, to loss of mass, prolonging the shelf life of the fruit in 10 days, but with no effect for the associations with source of calcium and oxidizing agent.</p>

LINEAR STABILITY ANALYSIS GENERALIZED TO A THERMALLY-DRIVEN FLOW

1999 ◽  
Vol 09 (02) ◽  
pp. 415-425
Author(s):  
JEAN-MICHEL CORNET ◽  
CLAUDE-HENRI LAMARQUE
Keyword(s):  
Stability Analysis ◽  
Numerical Methods ◽  
Linear Stability ◽  
Linear Stability Analysis ◽  
The Other ◽  
Basic Solution ◽  
Driven Cavity ◽  
Convective Flows ◽  
Other Hand ◽  
Thermally Driven

We intend to establish a methodology suited to the search of the first bifurcations of convective flows using a linear stability analysis so that it permits us to define a relationship between amplitude and frequency of the perturbation. We use a particular combination of various numerical methods to compute on one hand the basic solution. On the other hand the perturbation is applied to the search for the bifurcations in a thermally-driven cavity.

The Evaporation of Water from Helix Aspersa

1964 ◽  
Vol 41 (4) ◽  
pp. 759-769
Author(s):  
JOHN MACHIN
Keyword(s):  
Water Content ◽  
Water Loss ◽  
Vapour Pressure ◽  
Freezing Point ◽  
Muscular Activity ◽  
Helix Aspersa ◽  
Distilled Water ◽  
Atmospheric Conditions ◽  
Evaporative Water ◽  
Dry Air

1. Observations of intact specimens of Helix aspersa together with experiments with isolated skin preparations are described. 2. Under normal atmospheric conditions increases in haemocoelic pressure, probably due to general muscular activity, are sufficient to maintain the superficial mucous coating of the skin. 3. Under conditions of rapid water loss more intense muscular undulations serve to spread mucus which collects in the grooves to more exposed areas of the skin. 4. The water content, the rate of water loss in dry air, the equilibrium in saturated air and depression of freezing point of isolated mucus samples have been measured. 5. The vapour pressure of mucus has been shown to be within 0.4% of that of distilled water under the same conditions. 6. The significance of the above findings is discussed in relation to evaporative water loss and water uptake of an intact snail.

scholarly journals Use of biofilm in the postharvest conservation of 'Pedro Sato' guava

Revista CERES ◽  
2012 ◽  
Vol 59 (3) ◽  
pp. 305-312 ◽  
Author(s):  
Danielle Fabíola Pereira Silva ◽  
Luiz Carlos Chamhum Salomão ◽  
Laércio Zambolim ◽  
Aline Rocha
Keyword(s):  
Relative Humidity ◽  
Fruit Quality ◽  
Colletotrichum Gloeosporioides ◽  
Mineral Oil ◽  
Cassava Starch ◽  
Distilled Water ◽  
Taste And Odor ◽  
Fermentation Control

This present work aimed to assess the effect of different concentrations of cassava starch, associated or not with prochloraz fungicide, on the postharvest conservation of 'Pedro Sato' guavas. Physiologically mature fruits were immersed in a solution of prochloraz (49.5 g/100 liters of water) for 5 min. Fruit treated with distilled water and air dried were used as control. They were immersed in cassava starch suspension at concentrations of 0, 20, 30 and 40 g/L, plus 0.5 mL/L of mineral oil. The fruits were stored at 21.0 ± 1.0 ºC and relative humidity of 85 ± 5%, for 12 days, and were examined at every three days. The combination of prochloraz and cassava starch resulted in delayed loss of firmness and yellowness and inhibited the incidence of lesions caused by Colletotrichum gloeosporioides during the 12 days of storage. Fruits treated with 40 g/L of starch, whether containing prochloraz or not, had unpleasant taste and odor, which suggests the occurrence of fermentation. Control fruits, with and without prochloraz, and those treated with starch with no prochloraz, had nearly 100% lesion occurrence within the 12 days. Starch suspension of 30 g/L, containing prochloraz, was the most effective in maintaining fruit quality.

scholarly journals Experimental Analysis on Shrinkage and Swelling in Ordinary Concrete

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Barbara Kucharczyková ◽  
Petr Daněk ◽  
Dalibor Kocáb ◽  
Petr Misák
Keyword(s):  
Water Evaporation ◽  
Mass Measurements ◽  
Volume Changes ◽  
Ordinary Concrete ◽  
Concrete Shrinkage ◽  
Concrete Mixtures ◽  
Mass Losses ◽  
Shrinkage And Swelling ◽  
Loss Of Mass

The paper deals with the experimental determination of shrinkage development during concrete ageing. Three concrete mixtures were made. They differed in the amount of cement in the fresh mixture, 300, 350, and 400 kg/m3. In order to determine the influence of plasticiser on the progress of volume changes, another three concrete mixtures were prepared with plasticiser in the amount of 0.25% by cement mass. Measurements were performed with the goal of observing the influence of cement and plasticiser content on the overall development of volume changes in the concrete. Changes in length and mass losses of the concrete during ageing were measured simultaneously. The continuous measurement of concrete mass losses caused by drying of the specimen’s surface proved useful during the interpretation of results obtained from the concrete shrinkage measurement. During the first 24 hours of ageing, all the concrete mixtures exhibited swelling. Its magnitude and progress were influenced by cement, water, and plasticiser content. However, a loss of mass caused by water evaporation from the surface of the specimens was also recorded in this stage. The measured progress of shrinkage corresponded well to the progress of mass loss.

scholarly journals SOLVENT OPTIMIZATION OF ELECTROSPUN POLY(ACRYLIC ACID) NANOFIBERS

2021 ◽  
Vol 2021 ◽  
pp. 178-184
Author(s):  
M. Geysoğlu ◽  
F.C. Çallıoğlu
Keyword(s):  
Surface Tension ◽  
Acrylic Acid ◽  
Ph Value ◽  
Fibre Diameter ◽  
Optimum Process ◽  
Distilled Water ◽  
Solution Properties ◽  
Atmospheric Conditions ◽  
Fibre Morphology ◽  
Poly Acrylic Acid

In this study, it was investigated experimentally the influence of various solvents (distilled water and ethanol) on the solution properties, spinning performance, and fibre morphology of the electro spun Poly (acrylic acid) nanofibers. Firstly, polymer solutions were prepared at 5 wt % PAA with various solvent ratios of ethanol and distilled water. Then, solution properties such as viscosity, density, pH, conductivity, and surface tension were determined. The production of nanofiber samples was carried out by electrospinning under the optimum process parameters (voltage, distance between electrodes, feed rate, and atmospheric conditions). Finally, the morphological characterization of the nanofiber surface was carried out with SEM. According to the results, it was observed that conductivity, surface tension and the density of the solution increase as the ethanol ratio decreases. On the other hand, pH value increases as the ethanol ratio increases and, so, the acidic value of the solutions decreases. The viscosity increased until the ethanol/distilled water ratio was 50/50 and then decreased as the ethanol percentage decreased to under 50%. In addition, average fibre diameter decreases with ethanol ratio decreases. It is possible to say that solvent type affects solution properties, fibre morphology and spinning performance significantly. Generally, fine, uniform and bead free nanofibers could be electro spun and the PAA solution containing 70 wt % distilled water and 30 wt % ethanol was selected as the optimum in terms of fibre morphology, web quality and spinning performance.

scholarly journals Effect of whitening dentifrices containing optical agent on the variation of color, roughness and mass of a nanoparticulate composite resin

2020 ◽  
Vol 49 ◽  
Author(s):  
Rafaela Silva OLIVEIRA ◽  
Hannah Barros SIMÕES ◽  
Natália Nascimento ODILON ◽  
Max José Pimenta LIMA ◽  
Elisângela de Jesus CAMPOS
Keyword(s):  
Composite Resin ◽  
Distilled Water ◽  
Whitening Effect ◽  
Electric Toothbrush ◽  
Loss Of Mass

Abstract Introduction Blue covarine is a pigment that promotes optical changes in dental surfaces, providing whitening. Objective To evaluate in vitro the effect of bleaching dentifrices containing Blue covarine in nanoparticulate composite resin subjected to artificial darkening. Material and method One hundred sixty (160) specimens (PBs) of FILTEK Z350XT nanoparticulate composite resin were randomly divided into two experiments: Experiment I - 8 groups (n=10) submitted to brushing with an electric toothbrush for 1 month; Experiment II - 8 groups (n=10) submitted to simulated brushing for 6, 12 and 24 months. Groups were distributed according to the solution/dentifrice tested: CG (distilled water) and 7 test groups (GT1- Coltene Herjos, GT2- Colgate Total 12 Clean Mint, GT3- Colgate Luminous White Brilliant Mint, GT4- Oral B 3D White Perfection, GT5- Close Up White Now Glacier Fresh, GT6- Close Up White Attraction Diamond and GT7- Sorriso Xtreme White Evolution). Result In Experiment I, there was greater ∆E in GT6 in relation to CG, GT2, GT4 and GT5, with no differences among them. In Experiment II, after 24 months of brushing, there was greater ∆E in groups GT6 and GT7. After 24 months of simulated brushing, there was no change in roughness or loss of mass in any group. Conclusion The whitening effect promoted by dentifrices containing the agent Blue covarine seems to be related to the association of this agent with the abrasives present in the formulations of whitening dentifrices.

Solubility of basalt under atmospheric conditions of temperature and pressure

1965 ◽  
Vol 35 (270) ◽  
pp. 408-411 ◽  
Author(s):  
Beryl Nashar ◽  
Ralph Basden
Keyword(s):  
Laboratory Experiments ◽  
New South ◽  
Olivine Basalt ◽  
Atmospheric Temperature ◽  
Distilled Water ◽  
Atmospheric Conditions ◽  
Secondary Minerals ◽  
South Wales ◽  
Temperature And Pressure ◽  
Made In

SummarySimple laboratory experiments involving the contact of distilled water with crushed olivine-basalt over several months under atmospheric temperature and pressure conditions have shown that constituents are dissolved from the basalt and upon evaporation the solutions deposit crystals of carbonates, smectites, and zeolites. The results bear out the observations and conclusions previously made in the field that solutions depositing secondary minerals in Tertiary basalts in New South Wales are extraneous and cold. It is also suggested that as the assemblage calcite-montmorillonite-heulandite can form in the vesicles of basalts under such conditions it should not be included in the zeolite facies of metamorphism.

scholarly journals Studi Pembuatan Edible Film Gel Okra (Abelmoschus esculentus L.) dengan Penambahan Pati Singkong

2021 ◽  
Vol 4 (1) ◽  
pp. 94-108
Author(s):  
Siti Mukaromatul Muslimah ◽  
Warkoyo Warkoyo ◽  
Sri Winarsih
Keyword(s):  
Tensile Strength ◽  
Raw Materials ◽  
Block Design ◽  
Barrier Properties ◽  
Edible Films ◽  
Cassava Starch ◽  
Edible Film ◽  
Abelmoschus Esculentus ◽  
Cultivated Plants ◽  
Distilled Water

Edible film is an organic material packaging that has plastic-like properties but is biodegradable. The components of the edible film include hydrocolloids. Okra gel is a long chain hydrocoloid polysaccharide with a high molecular weight and a constituent protein containing both hydrophilic and hydrophobic substances. The hydrophilic characteristics are used to improve the physical properties of solubility. Meanwhile, hydrophobic characteristics are used to improve barrier properties (WVTR). Okra (Abelmoschus esculentus L.) is one of the cultivated plants that is currently underutilized by the community but has benefits and high nutritional content. The addition of cassava starch aims to increase the strength of the edible film. The purpose of this study was to determine the use of okra gel proportion and cassava starch concentration in making edible films which can produce edible film characteristics that meet the standards.This study used a factorial randomized block design (RBD). The first factor is the ratio of okra gel and distilled water (1: 3; 1: 1; 3: 1, 1:0). The second factor is the concentration of cassava starch (2.5% and 5% (w / v)). The parameters tested were yield of raw materials, thickness, solubility, transparency, tensile strength, elongation, WVTR (Water Vapor Transmison Rate) and SEM (Scanning Electron Microscopy).The results showed that there was no interaction between okra gel and cassava starch. However, the comparison of okra gel and distilled water had a significant effect on the transparency value with an average of 0.89-1.60 A546 / mm. The concentration of cassava starch has a significant effect on transparency 0.89-1.60 A546 / mm, tensile strength 0.97-2.33%. Edible film with the best treatment was obtained in G2P1 treatment (ratio of okra gel and distilled water (1: 1) and 2.5% cassava starch) with a thickness of 0.08mm, transparency 0.58A546 / mm, WVTR 3.87g / m2 / 24h, elongation 9.24%, tensile strength 0.74MPa and solubility 23.56%. And SEM analysis results show uneven morphology.

scholarly journals Thermoanalytical and starch content evaluation of cassava bagasse as agro-industrial residue

2009 ◽  
Vol 52 (spe) ◽  
pp. 143-150 ◽  
Author(s):  
Luiz Gustavo Lacerda ◽  
Rafael Ramires Almeida ◽  
Ivo Mottin Demiate ◽  
Marco Aurélio Silva Carvalho Filho ◽  
Eliane Carvalho Vasconcelos ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Starch Content ◽  
Thermal Characterization ◽  
Cassava Starch ◽  
Alternative Methods ◽  
Main Mass ◽  
Mass Losses ◽  
Cassava Bagasse ◽  
Industrial Residue ◽  
Total Starch

Starch nutritional fractions as well as thermal properties and other analysis are essential for food and industrial application. Cassava bagasse is an important agro-industrial residue and its starch content was evaluated using two alternative methods. Thermal characterization and microscopy analyses helped to understand how hydrolysis digests starchy fraction of cassava bagasse. The melting point of cassava starch occurred at 169.2ºC. Regarding TG analyses, after moisture content, there were observed two main mass losses for all samples. Results suggest hydrolysis carried out using enzyme is less effective in order to convert total starch content in cassava bagasse. However, using sulfuric acid, fibers are affected by analyses conditions.

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