scholarly journals Thermal and Mechanical Characteristics of Okra (Abelmoschus esculentus) Fibers Obtained via Water- and Dew-Retting

2020 ◽  
Vol 10 (15) ◽  
pp. 5113 ◽  
Author(s):  
Dawid Stawski ◽  
Ebru Çalişkan ◽  
Nazire Yilmaz ◽  
Izabella Krucińska
Keyword(s):  
Linear Density ◽  
Mechanical Characteristics ◽  
Breaking Strength ◽  
Thermal Analyses ◽  
Abelmoschus Esculentus ◽  
Elongation At Break ◽  
Density Values ◽  
Calculated Activation Energy ◽  
Range Of Values ◽  
Calculated Activation

In this research, fibers were extracted from different parts of the okra plant (Abelmoschus esculentus) via water- and dew-retting methods. The fibers were subjected to physical and thermal analyses. The fibers obtained from the upper part of the okra plant showed higher breaking strength and lower linear density. Fibers obtained via water-retting exhibited higher breaking strength, higher elongation at break rates, and lower linear density values. The paper also presents the results of thermogravimetric analysis of the okra fibers. Tests were carried out in oxygen and inert gas atmospheres. Slight differences were found in the thermal resistance of the tested fibers, which was confirmed by an analysis using the αs-αr methodology. The calculated activation energy showed a widespread range of values.

scholarly journals Thermal Characteristics of Okra (Abelmoschus Esculentus) Fibers Obtained via Water- and Dew-Retting

2020 ◽  
Author(s):  
Dawid Stawski ◽  
Ebru Çalişkan ◽  
Nazire Yilmaz ◽  
Izabella Krucińska
Keyword(s):  
Linear Density ◽  
Breaking Strength ◽  
Thermal Analyses ◽  
Thermal Characteristics ◽  
Abelmoschus Esculentus ◽  
Elongation At Break ◽  
Large Spread ◽  
Density Values ◽  
Calculated Activation Energy ◽  
Calculated Activation

In this study, fibers were extracted from different parts of the okra plant (Abelmoschus esculentus) via water- and dew-retting methods. The fibers were subjected to physical and thermal analyses. The fibers obtained from the upper part of the okra plant show higher breaking strength and lower linear density. Fibers obtained via water-retting exhibited higher breaking strength, elongation at break rates, and lower linear density values. The paper also presents the results of thermogravimetric analysis of the okra fibers. Tests were carried out in oxygen and inert gas atmospheres. The temperature range of the main thermal decomposition stage was in the 275–400°C for range thermo-oxidation and 300–425°C for pyrolysis investigation. Slight differences were found in the thermal resistances of the tested fibers, which was confirmed by an analysis using the alpha s- alpha r methodology. The calculated activation energy values show a large-spread range.

scholarly journals Comparisons between some composites reinforced with corn leaves and different matrices

2021 ◽  
Vol 343 ◽  
pp. 01002
Author(s):  
Alexandru Ioan Rădoi ◽  
Cosmin Mihai Miriţoiu ◽  
Claudiu Nicolicescu
Keyword(s):  
Tensile Test ◽  
Mechanical Characteristics ◽  
Breaking Strength ◽  
Testing Machine ◽  
Young Modulus ◽  
Rectangular Section ◽  
Polyester Resins ◽  
Elongation At Break ◽  
Universal Testing ◽  
The Matrix

In this paper we build some composite materials reinforced with corn leaves. In order to build the samples, we have firstly created some strips in this way: we put the corn leaves, continuously, on a sheet of paper where we apply a this layer of resin (we have used epoxy and polyester ones). We have waited for the resin polymerization 48 hours, recommended by the producer. We have put the corn leaves layers in the director of the tensile test (because we will test the samples to tensile). We have made 10 strips and we have glued them together by using the same synthetic resins (epoxy and polyester). In the end we have obtained some composites reinforced with strips from corn leaves and paper sheet, and the matrix is made from epoxy and polyester resins. From the obtained plate, we have cut some samples in order to study their statically mechanical characteristics by tensile test. The samples were tested on an universal testing machine INSTRON 1000 HDX which is assisted by a software called Bluehill. The samples have a rectangular section We have determined: the elongation at break, the breaking strength and the Young modulus. We have also studied the samples breaking area..

Determination of cotton fiber maturity and linear density (fineness) by examination of fiber cross-sections. Part 2: A comparison optical and scanning electron microscopy

2014 ◽  
Vol 84 (18) ◽  
pp. 1939-1947 ◽  
Author(s):  
Geoffrey RS Naylor ◽  
Margaret Pate ◽  
Graham J Higgerson
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cell Wall ◽  
Optical Microscopy ◽  
Cross Sections ◽  
Linear Density ◽  
Wall Area ◽  
Density Values ◽  
Fiber Maturity ◽  
Scanning Electron

Previous researchers established a set of reference cottons with known fiber maturity and linear density (fineness) values based on the analysis of a large number of individual transverse fiber cross-sections viewed under the optical microscope. Part 1 identified that the limited optical resolution of the captured images may be the source of a significant systematic error in the assigned values of cell wall area and hence fiber maturity and linear density values. In this paper the optical microscopy technique was implemented. Individual cross-sections were measured using this approach and also higher resolution and higher magnification images were obtained using scanning electron microscopy. It was found that the data obtained from optical microscopy were similar to the SEM data, with the perimeter being 2% smaller, the cell wall area being 6% larger and the maturity ratio values being 8% higher. It was concluded that the combined approach of utilizing SEM in conjunction with optical imaging is a useful approach for verifying and perhaps correcting the data obtained from optical imaging. Further the SEM images highlighted that the current experimental protocol does not adequately address the challenge of ensuring that the fibers are mounted normal to the plane of cutting the transverse cross-section. Modeling demonstrated that while maturity ratio values are relatively insensitive to this misalignment, measured cell wall area values and hence fiber linear density values will be overestimated. This may be the major source of error associated with the technique and warrants further attention in future studies.

Thermal Analysis on Dehydroxylation of Sol-Gel Derived Zinc Doped Calcium Phosphate Powders

2015 ◽  
Vol 1115 ◽  
pp. 353-356
Author(s):  
Gunawan ◽  
I. Sopyan
Keyword(s):  
Phase Stability ◽  
Room Temperature ◽  
Sol Gel ◽  
Conversion Degree ◽  
Zn Concentration ◽  
Calculated Activation Energy ◽  
Controlling Processes ◽  
Kinetics Of ◽  
Calculated Activation ◽  
Wall Method

The dehydroxylation of Zn free and 4 mol% Zn CaP powder was investigated using thermogravimetric analysis over the range of room temperature to 1200 °C. The kinetic result of dehydroxylation of Zn free and 4 mol% Zn CaP was calculated by means of the Ozawa–Flynn–Wall method. The XRD result indicated that the amount of Zn incorporated in HA lattice influences the phase stability of HA as it decreases with an increase in Zn concentration. According to calculated activation energy and conversion degree, the kinetics of HA dehydroxylation was identified, which included four successive conversion stages kinetically controlled by different rate-controlling processes. The dehydroxylation analysis of TG/DTG data show that Zn incorporation in HA lattice influences the phase stability of HA.

scholarly journals Evaluation of Microcrystalline Chitosan and Fibrin Membranes as Platelet-Derived Growth Factor-BB Carriers with Amoxicillin

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Kazimiera H. Bodek ◽  
Karolina M. Nowak ◽  
Marcin Kozakiewicz ◽  
Andrzej Bodek ◽  
Marta Michalska
Keyword(s):  
Growth Factor ◽  
Mechanical Characteristics ◽  
Composite Membranes ◽  
Mechanical Tests ◽  
Platelet Derived Growth Factor ◽  
Sem Images ◽  
Elongation At Break ◽  
Microcrystalline Chitosan ◽  
Kinetics Of

The aim of this study was to describe the mechanical and sorption features of homogeneous and composite membranes which consist of microcrystalline chitosan (MCCh) and fibrin (Fb) in various proportions as well as thein vitrokinetics of platelet-derived growth factor-BB (PDGF-BB) released from ten types of membranes in the presence or absence of amoxicillin (Am). The films were characterized by Fourier transform infrared (FTIR) spectroscopy, mechanical tests: breaking strength (Bs) and elongation at break (Eb), as well as SEM images, and swelling study. The influence of the form of samples (dry or wet) on Young’s modulus (E) was also examined. The homogeneous MCCh (M1) and composite M3 and M4 (MCCh : Fb = 2 : 1 and 1 : 1) membranes were characterized by good sorption properties and higher mechanical strength, when compared with Fb (M2) membrane. Connecting MCCh with Fb decreases release of PDGF-BB and increases release of Am. The most efficient release of PDGF-BB was observed in the case of M4 (the optimum MCCh : Fb ratio was 1 : 1) membrane. It was found that the degree of PDGF-BB release from the membrane is influenced by the physicochemical and mechanical characteristics of the films and by its affinity to growth factor PDGF-BB.

scholarly journals Dynamic Simulation of a Fe-Ga Energy Harvester Prototype Through a Preisach-Type Hysteresis Model

Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3384 ◽  
Author(s):  
Stefano Palumbo ◽  
Mario Chiampi ◽  
Oriano Bottauscio ◽  
Mauro Zucca
Keyword(s):  
Fixed Point ◽  
Mechanical Characteristics ◽  
Energy Harvester ◽  
Load Resistance ◽  
Type Model ◽  
Operating Parameters ◽  
Element Formulation ◽  
Electric Load ◽  
Good Convergence ◽  
Range Of Values

This paper presents the modeling of an Fe–Ga energy harvester prototype, within a large range of values of operating parameters (mechanical preload, amplitude and frequency of dynamic load, electric load resistance). The simulations, based on a hysteretic Preisach-type model, employ a voltage-driven finite element formulation using the fixed-point technique, to handle the material nonlinearities. Due to the magneto–mechanical characteristics of Fe–Ga, a preliminary tuning must be performed for each preload to individualize the fixed point constant, to ensure a good convergence of the method. This paper demonstrates how this approach leads to good results for the Fe–Ga prototype. The relative discrepancies between experimental and computational values of the output power remain lower than 5% in the entire range of operating parameters considered.

Improvement of Mechanical Properties and Water Absorption in Wheat Gluten by Epoxidized Natural Rubber

2019 ◽  
Vol 891 ◽  
pp. 163-168
Author(s):  
Kantima Chaochanchaikul
Keyword(s):  
Natural Rubber ◽  
Water Absorption ◽  
Thermal Analyses ◽  
Wheat Gluten ◽  
Research Work ◽  
Decomposition Temperature ◽  
Epoxidized Natural Rubber ◽  
Elongation At Break ◽  
Opposite Behavior ◽  
Internal Mixer

TThe aims of this research work were to improve touhgness and water resistance of wheat gluten (WG) by epoxidized natural rubber (ENR) compared to glycerol. WG specimens were mixed and prepared by internal mixer and compression molding machine, respectively. ENR and glycerol were varied from 10 to 40 wt%. Effects of modifier types and contents on WG were evaluated by tensile, impact and water absorption testings and microstructure and thermal analyses. The increase of ENR or glycerol contents led to the increase of toughness by considering the increase of impact strength and elongation at break. Glass transition temperature of WG tended to decrease with the increase of ENR or glycerol contents, especially for glycerol. The presence of glycerol affected to the decomposition temperature values whereas ENR did not affect to decomposition. ENR improved water resistant of WG specimen but trend of glycerol showed the opposite behavior. Weight loss of modified WG with glycerol was found at immersion time of 1440 min.

Investigation of factors affecting the seam slippage of garments

2019 ◽  
Vol 89 (21-22) ◽  
pp. 4756-4765
Author(s):  
Daoling Chen ◽  
Pengpeng Cheng
Keyword(s):  
Regression Analysis ◽  
Linear Equation ◽  
Linear Density ◽  
Breaking Strength ◽  
Pearson Correlation ◽  
Correlation Coefficients ◽  
Test Results ◽  
Factors Affecting ◽  
Polyester Material ◽  
Sewing Thread

Seam slippage often occurs with some garments during the process of wearing or washing, which not only affects the appearance of the garment but also influences garment quality. The purpose of this study is to find out the factors that affect the seam slippage of garments. In order to make the test results closer to those of the garment itself, this study first proposed to make the fabric into a Japanese woman's prototype sample, in order to simulate the garments produced by a garment enterprise. Then, according to standards GB/T 13772.2-2008/ISO 13936-2: 2004 and GB/T 21294-2014, samples were made and seam slippage at the armhole and side seam was tested. Experimental results reveal that the factors that cause the seam slippage of garments are the fabric, seam type and sewing thread. According to the regression analysis, the seam type has a significant effect on the seam slippage of the armhole and side seam, with Pearson correlation coefficients of −0.715 and −0.650, respectively. Thickness, weight, weft density and weave type of the fabric are also important in terms of seam slippage. The weight of the fabric is more significant than other factors; the significant values at the armhole and side seam are 0.009 and 0.002, respectively. In the linear equation, it is shown that weft breaking strength of the fabric only impacts the seam slippage at the side seam. Sewing thread is another important factor for the seam slippage of garments, and its influence on the armhole is obvious; the larger the sewing thread linear density of polyester material is, the smaller the seam slippage is.

About the Static Mechanical Properties of Epoxy/Hemp Composites

2020 ◽  
Vol 896 ◽  
pp. 321-326
Author(s):  
Cosmin Mihai Miriţoiu ◽  
Nicolae Craciunoiu ◽  
Alexandru Bolcu ◽  
Ionuţ Daniel Geonea ◽  
Ionica Valeriu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Standard Deviation ◽  
Tensile Test ◽  
Yield Stress ◽  
Mechanical Characteristics ◽  
Breaking Strength ◽  
Young Modulus ◽  
Breaking Elongation ◽  
Static Mechanical ◽  
Static Mechanical Properties

In this paper, static mechanical characteristics for some epoxy/hemp composites are studied. By using the tensile test, the static mechanical characteristics are determined, such as: breaking strength, yield stress, Young modulus and breaking elongation. There is also determined the standard deviation. Then, by using some known theories, there is validated the static Young modulus.

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