scholarly journals Caracterización comparativa de biopolímeros de almidón extraídos de cereales mediante dos técnicas diferentes

2020 ◽  
pp. 31-36
Author(s):  
Marisa Rivera-Arredondo ◽  
Mario Alberto Rodríguez-Ángeles ◽  
Verónica de Jesús Morales-Félix ◽  
Mariana Gaytán-Ruelas
Keyword(s):  
Oryza Sativa ◽  
Mechanical Strength ◽  
Avena Sativa ◽  
Chemical Characteristics ◽  
Crystalline Region ◽  
Environmental Legislation ◽  
Ecological Awareness ◽  
Naoh Treatment

In the field of research and consequent elaboration of biopolymers it has been growing in the last decade, either due to the hardening of the environmental legislation of each country or due to ecological awareness, in any case the term biopolymer is quite broad, these being used as material premium in medicines, food supplements and of course in the production of bioplastics. Since the topic of interest is the comparative characterization of biopolymers using starch extracted from two different cereals, oats and rice, using the alkaline technique with NaOH treatment and the milling technique, assuming that the starch extracted from the Oryza sativa cereal presents chemical characteristics, geometric and mechanical superior in both techniques used unlike the polymers made with Avena sativa starch. These results suggest that the starch quality of each cereal is relevant for the production of biopolymers [1]. The commercially significant properties of starch, such as its mechanical strength and flexibility, depend on the strength and character of the crystalline region, which depends on the ratio of amylose and amylopectin.

scholarly journals Comparative characterization of starch biopolymers extracted from cereals using two different techniques

2020 ◽  
pp. 21-26
Author(s):  
Marisa Rivera-Arredondo ◽  
Mario Alberto Rodríguez-Ángeles ◽  
Verónica de Jesús Morales-Félix ◽  
Marina Gaytán-Ruelas
Keyword(s):  
Oryza Sativa ◽  
Avena Sativa ◽  
Chemical Characteristics ◽  
Crystalline Region ◽  
Environmental Legislation ◽  
Ecological Awareness ◽  
Comparative Characterization ◽  
Naoh Treatment

In the field of research and consequent elaboration of biopolymers it has been growing in the last decade, either due to the hardening of the environmental legislation of each country or due to ecological awareness, in any case the term biopolymer is quite broad, these being used as material premium in medicines, food supplements and of course in the production of bioplastics. Since the topic of interest is the comparative characterization of biopolymers using starch extracted from two different cereals, oats and rice, using the alkaline technique with NaOH treatment and the milling technique, assuming that the starch extracted from the Oryza sativa cereal presents chemical characteristics, geometric and mechanical superior in both techniques used unlike the polymers made with Avena sativa starch. These results suggest that the starch quality of each cereal is relevant for the production of biopolymers [1]. The commercially significant properties of starch, such as its mechanical strength and flexibility, depend on the strength and character of the crystalline region, which depends on the ratio of amylose and amylopectin.

scholarly journals CHEMICAL-MINERАLOGICAL CHARACTERIZATION OF BAUXITES FROM DIFFERENT DEPOSITS

2014 ◽  
Vol 5 (1) ◽  
Author(s):  
Gordana Оstojić ◽  
Dragica Lazić ◽  
Branko Škundrić ◽  
Jelena Penavin Škundrić ◽  
Slavica Sladojević ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thermal Analysis ◽  
Raw Materials ◽  
Mineralogical Composition ◽  
Chemical Characteristics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

From the aspect of their chemical and mineralogical composition, bauxites are very complex multicomponent raw materials. The paper presents the characterization of bauxite from several different deposits: Brazil, Milići, Čitluk and Kosovo. Chemical characteristics were determined by a combination of different analytical methods: gravimetry, potentiometric titration, atomic absorption spectroscopy (AAS) and UV-VIS spectrophotometry. Mineralogical composition was determined using X-ray diffraction and thermal analysis methods. Chemical and structural characterization is complemented by the results of scanning electron microscopy with EDX analysis. The information obtained was used for the assessment of the quality of investigated bauxites from the aspect of their application in the production of alumina.

scholarly journals Thorough Characterization of Brazilian New Generation of Eucalypt Clones and Grass for Pulp Production

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Fernando José Borges Gomes ◽  
Jorge Luiz Colodette ◽  
Auphélia Burnet ◽  
Larisse Aparecida Ribas Batalha ◽  
Fernando Almeida Santos ◽  
...  
Keyword(s):  
Raw Material ◽  
Grass Species ◽  
Chemical Characteristics ◽  
Elephant Grass ◽  
Material Sources ◽  
Technological Quality ◽  
New Generation ◽  
Pulp Production

Eucalypt wood is becoming the most important raw material for the pulp industries in South America. However, due to the high wood cost in comparison to other raw material sources, nonwoody materials are also being investigated aiming at pulp production. In this way, this paper aimed at the evaluation of eighteen eucalypt clones obtained from the Brazilian Genolyptus project, regarding their potential characteristics for pulp production. Aiming at the same goal, two species of elephant grass were also evaluated as alternative raw material sources. Through the analyses of the anatomic and chemical characteristics, five eucalypt clones and one elephant grass species were indicated for pulp production and biorefinery application. The results of this study indicate the high technological quality ofEucalyptusclones evaluated and indicate that they can be used for biorefinery applications since they have the suitable characteristics. In general, the eucalypt clones are less moist and denser and contain fewer minerals and extraneous materials than the elephant grass species, which make them more attractive for utilization in deconstruction studies aiming at production of bioproducts.

scholarly journals Nutritional potential of dehydrated residues from rice milk production

2018 ◽  
Author(s):  
F. M. Fakhouri ◽  
Luan Ramos Silva ◽  
A. C. A. B. Casari ◽  
J. I. Velasco
Keyword(s):  
Oryza Sativa ◽  
Milk Production ◽  
Statistical Difference ◽  
Chemical Characteristics ◽  
Chemical Analyses ◽  
Black Rice ◽  
Physical And Chemical ◽  
Air Circulation ◽  
Nutritional Potential

The aim of this work was to verify the influence of drying on physical and chemical characteristics of residues from rice milk production. Residues were from the production of white, red and black rice. They were dehydrated in an oven with air circulation at 60ºC for 8h. Characterization of them were carried out by physical and chemical analyses. Residues have presented statistical difference for all parameters measured. Its characterization is necessary to justify its use in other process or application on new products.The residues from rice milk production have high content of nutrients and phenolic compounds, even after dehydration. Keywords: Nutrients; Oryza sativa; waste.

scholarly journals CHARACTERIZATION OF 3D-PRINTING FILAMENT WITH EXTRUDER MELTING TEMPERATURE VARIATION FOR BONE IMPLANT FROM KUPANG SHELL

2022 ◽  
Vol 2 (2) ◽  
pp. 73
Author(s):  
Ananda Maulidha Kusumastuti ◽  
Adik Roni Setiawan ◽  
Asalina Putri Agung Shaliha ◽  
Deden Eko Wiyono ◽  
Achmad Ferdiansyah Pradana Putra
Keyword(s):  
3D Printing ◽  
Mechanical Strength ◽  
Melting Temperature ◽  
Organic Materials ◽  
Bone Implants ◽  
Bone Implant ◽  
Bone Damage ◽  
Mussel Shells

<p><em>The number of bone damage in Indonesia continues to increase. Bone implant is one of the medical treatment methods performed on bone damage. Organic and non-organic materials can be used as bone implants. Non-organic materials are stronger, but not biocompatible, while organic materials are biocompatible, but brittle. The addition of polycaprolactone polymer (PCL) can increase the mechanical strength of 3D printing bone implant filaments. Extruder melting temperature is one of the factors that affect the quality of PCL-HAp filaments for bone implants. Studies related to temperature variations in PCL-HAp materials have not been widely studied. Therefore, it is necessary to characterize 3D printing filaments with variations in the melting temperature of the extruder as bone implants from mussel shells with temperature variables of 65<sup>o</sup>C, 75<sup>o</sup>C, and 85<sup>o</sup>C. From this study, the optimum point was found at the melting extruder temperature of 75<sup>o</sup>C with the results of a diameter of 1.810 and mechanical strength which showed an increase in tensile strength and Young's modulus of PCL-HAp composite in all variables compared to pure PCL. The SEM test showed a rough surface on the filaments that could increase the proliferation and adhesion of good cells for the growth of bone tissue.</em></p>

Characterization of a Clay Body Used for Red Ceramics in São Sebastião, District of Campos dos Goytacazes, State of Rio de Janeiro, Brazil

2015 ◽  
Vol 820 ◽  
pp. 8-12 ◽  
Author(s):  
Afonso Rangel Garcez de Azevedo ◽  
Jonas Alexandre ◽  
Euzébio Barnabé Zanelato ◽  
Rafael Picanço Oliveira ◽  
Rodolfo Cretton de Souza ◽  
...  
Keyword(s):  
Rio De Janeiro ◽  
Northern Region ◽  
Chemical Characteristics ◽  
Technological Properties ◽  
Clay Deposits ◽  
Clay Body ◽  
Physical And Chemical ◽  
Red Ceramics

The municipal area of Campos dos Goytacazes in the northern region of the state of Rio de Janeiro, Brazil, is the state’s major industrial pole for red ceramic fabrication. The extensive clay deposits and easy to mine conditions have attracted more than one hundred ceramic industries to operate in the area. In particular, the district of São Sebastião contributes to the production of red bricks and tiles but the characterization of the existing clay and the quality of ceramic pieces has not yet been evaluated. Therefore the present work carried out an investigation of a typical clay body used in São Sebastião by means of its physical and chemical characteristics. The technological properties of red ceramics fabricated from this clay body and fired at temperatures of 700, 850 and 1100oC indicate that they comply with the mechanical strength requirements for masonry bricks. However water absorption is not satisfactory due to the excess of sand and lack of fluxing elements.

Characterization of defects in tabular silver halide grains

1990 ◽  
Vol 48 (4) ◽  
pp. 1046-1047
Author(s):  
C. Goessens ◽  
D. Schryvers ◽  
J. Van Landuyt ◽  
A. Verbeeck ◽  
R. De Keyzer
Keyword(s):  
Radiation Damage ◽  
Silver Halide ◽  
Chemical Characteristics ◽  
X Ray ◽  
Free Region ◽  
Central Defect ◽  
Crystallographic Defects ◽  
Physical And Chemical ◽  
Two Sides

Silver halide grains (AgX, X=Cl,Br,I) are commonly recognized as important entities in photographic applications. Depending on the preparation specifications one can grow cubic, octahedral, tabular a.o. morphologies, each with its own physical and chemical characteristics. In the present study crystallographic defects introduced by the mixing of 5-20% iodide in a growing AgBr tabular grain are investigated. X-ray diffractometry reveals the existence of a homogeneous Ag(Br1-xIx) region, expected to be formed around the AgBr kernel. In fig. 1 a two-beam BF image, taken at T≈100 K to diminish radiation damage, of a triangular tabular grain is presented, clearly showing defect contrast fringes along four of the six directions; the remaining two sides show similar contrast under relevant diffraction conditions. The width of the central defect free region corresponds with the pure AgBr kernel grown before the mixing with I. The thickness of a given grain lies between 0.15 and 0.3 μm: as indicated in fig. 2 triangular (resp. hexagonal) grains exhibit an uneven (resp. even) number of twin interfaces (i.e., between + and - twin variants) parallel with the (111) surfaces. The thickness of the grains and the existence of the twin variants was confirmed from CTEM images of perpendicular cuts.

Physicochemical and bacteriological characterization of hospital effluents and their impact on the environment

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Human Health ◽  
Fecal Coliforms ◽  
Chemical Pollution ◽  
Hospital Effluents ◽  
Biological Contaminants ◽  
Almost All ◽  
Direct Discharge ◽  
Significant Chemical

Liquid effluents discharged by hospitals may contain chemical and biological contaminants whose main source is the different substances used for the treatment of patients. This type of rejection can present a sanitary potentially dangerous risk for human health and can provoke a strong degradation of diverse environmental compartments mainly water and soils. The present study focuses on the quality of the liquid effluents of Hassani Abdelkader’s hospital of Sidi Bel-Abbes (West of Algeria). The results reveal a significant chemical pollution (COD: 879 mgO2/L, BOD5: 850 mgO2/L, NH4+ : 47.9 mg/l, NO2- : 4.2 mg/l, NO3- : 56.8 mg/l with respect to WHO standard of 90 mgO2/L, 30 mgO2/L, 0.5 mg/l, 1 mg/l and 1 mg/l respectively). However, these effluents are biodegradable since the ratio COD/BOD5 do not exceeded the value of 2 in almost all samples. The presence of pathogen germs is put into evidence such as pseudomonas, the clostridium, the staphylococcus, the fecal coliforms and fecal streptococcus. These results show that the direct discharge of these effluents constitutes a major threat to human health and the environment.

The basis of quality of sheep pelts and fur products is morphological features of the skin of sheep

2020 ◽  
pp. 50-57
Author(s):  
I. Dmitrik ◽  
G. Zavgorodnyaya
Keyword(s):  
Mechanical Strength ◽  
Breaking Load ◽  
Hair Follicles ◽  
Morphological Features ◽  
High Density ◽  
Fat Cells ◽  
High Quality ◽  
Histological Features ◽  
Weakened Zone

The morphological and histological features of the skin and wool cover of sheep as the basis for the quality of fur sheep pelts have been studied. The most important properties of sheep pelts (uniformity, thinness and density of wool) are provide the possibility of producing high-quality fur semi-finished products from them. However, the features of the histostructure of fine-wool sheep determine the low mechanical strength of the “facial” layer of skin. As a result, the “front” layer during processing often cracks to the upper border of the reticular layer or even peels off from the latter, making the sheep pelt unsuitable for use on fur products. These defects in fur practice are called “cracking” and “peeling” of the facial layer. They are mainly peculiar to sheep pelts of fine-wooled sheep. In these animals due to the high density and tone of the coat, the roots and hair follicles, root vaginas, secretory departments, excretory ducts of the glands and other structures occupy a significant share of the volume in the thickness of the Pilar layer (up to 25–30 %). The share of fibrous structures remains less volume, and these structures themselves are relatively weakly developed, located loosely and loosely intertwined with each other. The accumulations of fat cells that occur here also cannot be attributed to skin-strengthening elements. In fine-fleece sheep the pilar layer is on average 60 % of the thickness of the dermis. Therefore, more than half of its thickness is a weakened zone. The strength of the “front” layer is not the same in different fine-wool breeds of sheep and in different animals within the breed. For example, the average breaking load for cod of the “front” layer in Soviet Merino pelts is 1,25 kg, and in Precoce is 2,49 kg.

Sign in / Sign up

Export Citation Format

Share Document