scholarly journals Mechanical properties of native maize, wheat, and potato starches

2013 ◽  
Vol 31 (No. 4) ◽  
pp. 347-354 ◽  
Author(s):  
M. Stasiak ◽  
M. Molenda ◽  
I. Opaliński ◽  
W. Błaszczak
Keyword(s):  
Mechanical Properties ◽  
Moisture Content ◽  
Mechanical Behaviour ◽  
Potato Starch ◽  
Uniaxial Compression Test ◽  
Strength Parameters ◽  
Ring Shear ◽  
Potato Starches ◽  
Particle Sizer ◽  
Shear Tester

The interrelations between moisture content and mechanical properties of dry and wet native starches of wheat, maize, and potato were investigated. Strength parameters of powders were tested using direct shear and ring shear tester. Carr indices and associated parameters were determined using a Hosokawa Powder Tester. Particle size distribution of powder was analysed using an Infrared Particle Sizer. Uniaxial compression test was conducted to determine the reaction of powder in a cylindrical probe to vertical load. Mechanical behaviour of the material was found to be changing with increasing moisture content. Mechanical behaviour of potato starch was found to be different from that of cereal starches, which may require different utilisation in some processes.  

scholarly journals Effect of gamma irradiation on physicochemical characteristics and microbiological quality at different ratio of tapioca and potato starches of flat rice noodle

Food Research ◽  
2020 ◽  
Vol 4 (5) ◽  
pp. 1500-1512
Author(s):  
Ahmad Zainuri M.D. ◽  
Wan-Zunairah W.I. ◽  
Farah-Nadiah A.R. ◽  
Fatimah M.H.B. ◽  
Nor-Khaizura M.A.R. ◽  
...  
Keyword(s):  
Moisture Content ◽  
Gamma Irradiation ◽  
Ph Value ◽  
Potato Starch ◽  
Microbiological Quality ◽  
Physicochemical Characteristics ◽  
Plate Count ◽  
Potato Starches ◽  
Cooking Yield

Flat rice noodle is classified under non-wheat noodles due to the absence of gluten and required gelatinization of starch during processing. It is also very susceptible to spoilage and has a short shelf-life because of the high moisture content. This study was conducted to investigate and compare the effect of gamma irradiation on the physicochemical characteristics and microbiological quality of containing two different starches. Tapioca starch (TS) and potato starch (PS) were incorporated into the formulations at 3 levels (3%, 8% and 11%) and was irradiated at 4 doses of 0 (control), 4, 6, and 8 kGy with dose rate of 42.78 Gy/min by using 60Cobalt. Total plate count (TPC) was performed where samples were stored at 8°C and examined for day 1, 3, 5, and 7. Results showed that all doses of irradiation did not significantly (p>0.05) affected the moisture content and water activity of samples. However, gamma irradiation significantly (p<0.05) decreased the pH value, cooking yield, lightness, and hardness of the samples; whereas it significantly (p<0.05) increased the cooking loss, colour (a* and b*), and breaking length. Meanwhile, cooking yield, lightness, and hardness of samples containing PS were higher compared to samples containing TS. Moisture content for samples containing both TS and PS was higher compared to samples containing single starch. TPC showed that irradiation was able to control microbial growth. Moreover, no microbial load was detected on samples irradiated at 8 kGy until day 7. It was thus shown that increased doses in gamma irradiation could improve microbiological quality of flat rice noodles

scholarly journals PERMEABILITY AND MECHANICAL BEHAVIOUR OF MICROWAVE PRE-TREATED NORWAY SPRUCE RIPEWOOD

Wood Research ◽  
2021 ◽  
Vol 66 (4) ◽  
pp. 569-581
Author(s):  
DOMINIK HESS ◽  
PETR PAŘIL ◽  
JAKUB DÖMÉNY ◽  
JAN BAAR
Keyword(s):  
Mechanical Properties ◽  
Moisture Content ◽  
Norway Spruce ◽  
Mechanical Behaviour ◽  
Vacuum Pressure ◽  
Average Depth ◽  
Depth Of Penetration ◽  
Pre Treatment ◽  
Variable Moisture Content

This is a studyofthe influence of microwave (MW) pre-treatment on the permeabilityof Norway spruceripewood(Picea abiesL. Karst)as it affects its mechanical properties. Specimens weretreated under variable moisture content,MW intensity,and impregnation processes. According to the results,thespecimens withaninitial moisture contentof 45–65% exhibited the highest permeabilityvaluescompared to referencesamples. Aninsignificant difference was found between MW pre-treatments at2 and3kW.Statistically significant results were found afterlong-time (24h) vacuum-pressureimpregnation(LP). Theaverage retention value followingLP was 132 kg.m-3, which isalmost threetimes greater thanthe MW-treatedgroupsimpregnated in ashort-time vacuum-pressure process. The average depth of penetration after LP was 2.0mm and the proportion of the impregnation area followingLP was 17.6%. MW pre-treatment had no effect on the impregnability or the mechanical propertiesof the wood; other MW regimes are open for further examination.

scholarly journals Mechanical properties of potato starch modified by moisture content and addition of lubricant

2014 ◽  
Vol 28 (4) ◽  
pp. 501-509 ◽  
Author(s):  
Mateusz Stasiak ◽  
Marek Molenda ◽  
Józef Horabik ◽  
Peter Mueller ◽  
Ireneusz Opaliński
Keyword(s):  
Mechanical Properties ◽  
Internal Friction ◽  
Moisture Content ◽  
Bulk Density ◽  
Modulus Of Elasticity ◽  
Potato Starch ◽  
Magnesium Stearate ◽  
Wall Friction ◽  
Considerable Influence ◽  
Angle Of Internal Friction

Abstract Laboratory testing was conducted to deliver a set of characteristics of structure and mechanical properties of pure starch and starch with an addition of a lubricant - magnesium stearate. Considerable influence of moisture content of potato starch was found in the case of density, parameters of internal friction, coefficients of wall friction and flowability. Elasticity was found to be strongly influenced by water content of the material. Addition of magnesium stearate affected density and parameters of flowability, internal friction and elasticity. Bulk density increased from 604 to 774 kg m-3 with decrease in moisture content of potato starch from 17 to for 6%. Addition of magnesium stearate resulted in approximately 10% decrease in bulk density. Angle of internal friction obtained for 10 kPa of consolidation stress decreased from 33 to 24º with increase in moisture content, and to approximately 22º with addition of the lubricant. With an increase of moisture content from 6 to 18% and with addition of the lubricant, the modulus of elasticity during loading decreased from approximately 1.0 to 0.1 MPa. Modulus of elasticity during unloading was found in the range from 19 to 42 MPa and increased with increase of moisture content and amount of lubricant.

scholarly journals Influence of Moisture Content on the Structural Characteristics of Argillaceous Weakly Consolidated Rock Caused by Dynamic Loading in the Coal Mine

2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Lingdong Meng ◽  
Lijun Han ◽  
Hexuan Zhu ◽  
Wenlong Dong ◽  
Wei Li
Keyword(s):  
Mechanical Properties ◽  
Moisture Content ◽  
Structural Characteristics ◽  
Soft Rock ◽  
Uniaxial Compression Test ◽  
Hopkinson Pressure Bar ◽  
Dynamic Impact ◽  
Porosity Variation ◽  
Bar Test ◽  
Pressure Bar

The argillaceous weakly consolidated rock is a kind of soft rock that will bring great difficulties in the construction process. Specimens of such rock under different moisture contents are taken as the research object. By the Hopkinson pressure bar test (SHPB), the structural and mechanical characteristics of the rock under dynamic impact are analysed. With increasing moisture content, the transmitted wave amplitude decreases gradually, which indicates that the higher the moisture content of the rock is, the easier it is to deform under dynamic impact and the greater its plasticity. The boundary between plastic failure and brittle failure is 10% moisture content. Through a mercury injection test, the porosity variation is analysed. The porosity of the rock decreases with increasing moisture content after the same dynamic impact. The porosity curve can be roughly divided into two sections with a moisture content of 15% as the boundary. Based on a uniaxial compression test, the elastic modulus, peak strength, and residual strength of specimens after dynamic impact are analysed, and the mechanical properties of the rock are revealed. Its mechanical properties can be divided into three sections with a moisture content of 9.18% and 15.19%, and each section has obvious differences.

Mechanical Analysis of Biodegradable Films from Native and Chemically Modified Potato Starches

2016 ◽  
Vol 869 ◽  
pp. 830-834
Author(s):  
Laura Martins Fonseca ◽  
Valeska Rodrigues Roque ◽  
Ana Paula Jardim Roquete ◽  
Anelise Mossmann ◽  
Lorena Aparecida Nunes Viana ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Film Formation ◽  
Potato Starch ◽  
Tensile Tests ◽  
Optical Microscope ◽  
Mechanical Analysis ◽  
Active Chlorine ◽  
Biodegradable Films ◽  
Chemically Modified ◽  
Potato Starches

The production of biodegradable films has been studied to be a substitute of conventional plastics. The use of starch in biodegradable films are of great interest and starch modification improves an increase to the mechanical properties the film. The mechanical properties were evaluated by Dynamic Mechanical Analysis (DMA). The aim of this study is to determine the mechanical properties of biodegradable films produced from native and chemically modified potato starch. The starch was extracted and subjected to chemical modification by oxidation in different concentrations of active chlorine. The biodegradable films were prepared with starch and glycerol as plasticizer, and were observed with an optical microscope to evaluate the morphology and their relationship with the strength. The tensile tests were performed at 80oC to evaluate the mechanical properties by means of stress-strain curves. The morphology of biodegradable potato starch films shows that the starch granules were partially gelatinized during the film formation. As the elastic modulus is a property which determines the stiffness of the material, by means of he DMA analysis it can be seen that oxidation results in beneficial changes in the mechanical properties of the films, because the modulus increased from 346.70 MPa for the native starch to 651.75 MPa to oxidized starch with 1.5% of active chlorine, respectively.

scholarly journals Studi Pendahuluan Sifat Teknis Tanah Lempung Pada Daerah Rawan Gerakan Tanah Di Dusun Beji Desa Cirahab Kecamatan Lumbir Kabupaten Banyumas

2021 ◽  
Vol 22 (1) ◽  
pp. 35
Author(s):  
Ary Sismiani ◽  
Iwan Rustendi
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Moisture Content ◽  
Water Content ◽  
Strength Parameter ◽  
Soil Slope ◽  
Shear Strength Parameters ◽  
Strength Parameters ◽  
Soil Movement ◽  
Soil Shear Strength

In several places in the Banyumas Regency area, land movement problems have often occurred. Several locations have been declared as red zones, one of which is Beji, Cirahab Village, Lumbir District. With such regional conditions, it is necessary to conduct a study of the technical and mechanical properties of the soil in that location including moisture content, density and shear strength parameters related to the possibility of soil movement that will occur. From the results of the test and analysis using 3 specimens, the following data were obtained: water content of 20.22%, 30.36%, 40.31% with a cohesion value of 0.14 kg / cm2, 0.56 kg / cm2, 0.33 kg / cm2, and the internal friction angles of the soil are 30.22 °, 24.47 °, and 18.93 °. While the value of shear stress and displacement at maximum normal stress and moisture content of 20.22%, 30.36%, 40.31% are t(w1) = 0.68 kg / cm2,  t(w2) = 1.01 kg / cm2 ,t (w3) = 0.68 kg / cm2 and dn1 = 15.02%, dn2 = 10.02, dn3 = 13.35%. It can be concluded that the water content always has a very big influence on the value of the soil shear strength parameter. Therefore, the condition of the water content on the soil slope needs to be considered, and it is necessary to carry out further tests and more serious handling at that location.

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