Tribotesting

2021 ◽  
pp. 121-162
Keyword(s):  
Adhesive Wear ◽  
Test Parameters ◽  
Different Types ◽  
Wear Damage ◽  
Abrasion Testing

Abstract This chapter discusses the processes and procedures involved in tribotesting, the significance of test parameters and conditions, and practical considerations including test metrics and measurements and the interpretation of wear damage. It also describes the different types of erosion tests in use and common approaches for adhesive wear and abrasion testing.

scholarly journals Determination of extensibility for certain types of pretzels dough

2019 ◽  
Vol 112 ◽  
pp. 03029
Author(s):  
Mariana Gabriela Munteanu ◽  
Gheorghe Voicu ◽  
Elena Mădălina Ştefan ◽  
Gabriel Alexandru Constantin
Keyword(s):  
Mechanical Deformation ◽  
The Other ◽  
Maximum Elongation ◽  
Test Parameters ◽  
Different Types ◽  
The Moment ◽  
Dough Extensibility ◽  
Processing Steps ◽  
Initial Geometry

Determination of pretzels dough is essential to analyse the technological process, the dough handling behaviour and properties of the finished product. In various processing steps such as kneading, dividing, shaping and baking the dough undergoes different mechanical deformation, including the extent, compression or shear. In the literature there are several methods for analysing these properties. These include empirical rheological methods, such as recording dough evolution during kneading, extensibility measurement or fundamental rheological methods. The study in this paper propose to investigate the behaviour of different types of test dough extensibility and make estimates of the values of the moment (time) and maximum force that wick dough is deformed to appearance of fracture. The maximum elongation of the dough wick is determined for the same values of its initial geometry as well as the other test parameters for two types of dough, one with a composition of 45% water, 10% oil and 45% flour, and another with a composition of 55% water, 10% oil and 35% flour. Preliminary results have found that a dough with more water has a greater tensile strength than the dough with the same amount of oil and less water.

Study on the Effect of Wear Resistant Materials Applications in Reducing Wear Damage of Gas Turbine Combustor Components

2014 ◽  
Vol 575 ◽  
pp. 17-21 ◽  
Author(s):  
Ahmad Afiq Pauzi ◽  
Shuib Husin
Keyword(s):  
Abrasive Wear ◽  
Gas Turbine ◽  
Adhesive Wear ◽  
Fretting Wear ◽  
Gas Turbine Combustor ◽  
Surface Degradation ◽  
Wear Resistant ◽  
Inspection Interval ◽  
Transition Piece ◽  
Wear Damage

Wear is the main problem in gas turbine combustor components. The mating surfaces experience surface degradation affected by wear damage. The main mechanisms of wear occurred on combustor components could be adhesive wear, abrasive wear, and fretting wear. Wear resistant materials such as Haynes 25 (L605) and Stelitte 6 were selected to be used in reducing wear damage especially on bull horn, transition piece and flow sleeve of combustor components. The reduction of wear on combustor components can be described as the extension of combustion inspection interval of a gas turbine. It is concluded that wear on combustor components can be reduced by the applications of wear resistant materials on the components.

Constant Power Principle in Abrasion Testing

1956 ◽  
Vol 29 (1) ◽  
pp. 187-206 ◽  
Author(s):  
E. F. Powell ◽  
S. W. Gough
Keyword(s):  
Test Design ◽  
Constant Power ◽  
Underlying Principle ◽  
Constant Rate ◽  
Different Types ◽  
Resistance To Wear ◽  
The Many ◽  
Service Data ◽  
Work Done ◽  
Abrasion Testing

Abstract This paper has been mainly concerned with presenting the case for power control in abrasion testing, and the implications of the better understanding of the mechanism of abrading. It is not claimed that the test machines described are perfect in their ability to assess resistance to wear action. There is still much to be done to remove anomalies that can still occur in results. One underlying principle, that of constant rate of energy dissipation at the abrading surface, is proposed as a criterion for comparison of the validity of test design for the many different types of laboratory test in regular use for assessment of wear resistance. Modification of the Lambourn constant-slip machine to make it conform with the constant-power principle is described, and the degree of correlation with service data on tires given. The effects of several major variables on the abrasion loss of rubber tread compounds, when tested with the modified Lambourn machine, are reported, including work on combating stickiness. Experiments with the Du Pont and U. S. Bureau of Standards abraders, modified to conform to constant-power principles, are also reported in this paper. The relations between work done in mechanically grinding rubber and the energy associated with the bonds ruptured in the grinding action are considered. It is suggested that a correlation may exist between abrasion and high-temperature flexibility properties of rubber.

Correlation between Laboratory Abrasion and Road Testing

1958 ◽  
Vol 31 (2) ◽  
pp. 387-392 ◽  
Author(s):  
C. Prat
Keyword(s):  
Natural Rubber ◽  
Correlation Coefficients ◽  
The Road ◽  
Different Types ◽  
Standard Of Comparison ◽  
On The Road ◽  
Road Testing ◽  
Abrasion Testing ◽  
Very High ◽  
Reference Mixture

Abstract In a preceding article, we expressed the hypothesis that probably no discontinuity exists between abrasion testing on the road and that on laboratory machines. The latter showed the peculiarity of being characterized by its very high severity. Let us recall briefly that the severity is expressed by the absolute wear of a reference mixture during the test considered. We were able to verify the existence of a relationship independent of the type of testing carried out, but a function of the severity of the tests, between the wear of an experimental mixture and a reference mixture. This relation manifests itself in different types of mixtures in the form of regressing lines. These are shown in Figure 1 where we have used logarithmic coordinates. The correlation coefficients calculated for different regressions are in the neighborhood of 0.93 to 0.95 and consequently very highly significant. The interpretation and use of the curves shown on the graph necessitates, however, a few remarks of importance: Firstly, it must be noted that each of the lines corresponds to a particular standard of comparison. Each of them is independent of the others. for example, for that labelled “Rubber-Resin A”, the comparison rests on the wear of this type of combination rubber-resin as a function of the wear of the mixture (natural rubber containing 28 volumes of HAF black) having served as a reference for the tests, while for the line labelled “Rubber + SAF black”, the reference mixture is a natural rubber containing 28 volumes of MPC black. It will not be necessary then, in any case to compare the curve for “Rubber-SAF Black” to that for “Rubber-Resin A”.

scholarly journals Wear Performance of Value-Addition Epoxy/Breadfruit Seed Shell Ash Particles and Functionalized Momordica Angustisepala Fiber Hybrid Composites

2020 ◽  
Vol 30 (5-6) ◽  
pp. 195-202
Author(s):  
Vincent C. Ezechukwu ◽  
Chukwuemeka C. Nwobi-Okoye ◽  
Philip N. Atanmo ◽  
Victor S. Aigbodion
Keyword(s):  
Wear Resistance ◽  
Wear Rate ◽  
Wear Mechanism ◽  
Adhesive Wear ◽  
Hybrid Composites ◽  
Numerical Approach ◽  
High Wear Resistance ◽  
Wear Performance ◽  
Wear Damage ◽  
Hardness Values

The numerical approach for the study of wear performance of breadfruit seed shell ash particles (BFSAp) and Sodium hydroxide (OH)/silane (APS)functionalized Momordica angustisepala fiber (MAf)/epoxy hybrid composites were investigated. The MAf fibers were treated with an OH-APS solution. Hardness values, wear rate and wear mechanism of the samples were determined. A 65.82% improvement in wear resistance was obtained at the load of 30N of 30wt%MAf-20wt%BFSAp composite. The wear rate and wear damage followed in this order: epoxy(matrix)˂epoxy/30wt%MAf-20wt%BFSAp˂epoxy/OH-APS treated 30wt%MAf-20wt%BFSAp composites. The wear mechanism observed in this work is a combination of abrasive and adhesive wear. High wear resistance was obtained in epoxy/OH-APS treated 30wt%MAf-20wt%BFSAp composites.

Damage behavior of orthopedic titanium alloys with martensitic microstructure during sliding wear in physiological solution

2019 ◽  
Vol 28 (8) ◽  
pp. 1228-1247 ◽  
Author(s):  
Ivana Cvijović-Alagić ◽  
Zorica Cvijović ◽  
Marko Rakin
Keyword(s):  
Friction Coefficient ◽  
Wear Rate ◽  
Friction And Wear ◽  
Adhesive Wear ◽  
Damage Mechanism ◽  
Physiological Solution ◽  
Material Transfer ◽  
Damage Behavior ◽  
Martensitic Microstructure ◽  
Wear Damage

Wear damage behavior of new orthopedic Ti-13Nb-13Zr (mass %) alloy with martensitic microstructures developed by different thermo-mechanical treatments were examined during sliding in simulated physiological solution. The results obtained for this alloy processed by cold and hot rolling were compared with that of the standard Ti-6Al-4 V (mass %) alloy heat-treated to produce martensitic microstructure. The block-on-disk sliding friction and wear tests were conducted in Ringer’s solution. The friction coefficient, wear rate, and wear damage mechanisms were determined over a range of normal loads (20–60 N) and linear sliding speeds (0.26–1.0 m/s). The surface damage morphology revealed the presence of corrosive, abrasive, and adhesive wear in all investigated materials. The friction and wear properties were found to be dependent on the predominant wear damage mechanism and applied load/sliding speed combination. In the case of a Ti-13Nb-13Zr alloy, the adhesive wear contributes to the higher wear rate and better friction behavior. This cold-rolled alloy, having a martensitic microstructure with the lowest hardness, shows the lowest friction coefficient values due to high material transfer from the alloy surface. The lowest friction resistance is observed for the Ti-6Al-4 V alloy with the highest hardness since the dominant wear damage mechanism is abrasion resulting in the low wear rate and material transfer.

scholarly journals The effect of metribuzin on the density of proteolytic microorganisms and proteolytic activity in different types of soil

2018 ◽  
Vol 33 (3-4) ◽  
pp. 233-240
Author(s):  
Ljiljana Santric ◽  
Ljiljana Radivojevic ◽  
Marija Saric-Krsmanovic ◽  
Jelena Gajic-Umiljendic ◽  
Rada Djurovic-Pejcev
Keyword(s):  
Sandy Soil ◽  
Protease Activity ◽  
Microbial Population ◽  
Soil Samples ◽  
Loamy Soil ◽  
Factors Influencing ◽  
Soil Ecosystems ◽  
Test Parameters ◽  
Different Types ◽  
Physical And Chemical

Soil texture and other physical and chemical characteristics of soil are important factors influencing the retention of herbicides in soil ecosystems. A laboratory experiment was conducted to estimate the response of proteolytic microorganisms to applications of metribuzin in different types of soil (loamy and sandy) in terms of density and protease activity. The following concentrations were tested: 12.0, 24.0, 120.0 and 1200.0 mg a.i.kg-1 soil. Samples were collected 7,14 and 30 days after treatment with metribuzin. Metribuzin did not affect the number of proteolytic microorganisms in loamy soil. In sandy soil, their number was reduced 26.7% by the highest concentration 7 days after application. Protease activity was reduced in both types of soil on the 7th and 14th day and the percentage of reduction was 21% for loamy soil and 29.9% for sandy soil. Statistical analysis of data showed that the correlation between test parameters was positive in both types of soil (r2=1 for loamy soil, and r2=0.81 for sandy soil). The study shows that metribuzin causes a passable impact on microbial population and enzymatic activity which depends on the type of soil.

AN EFFECTIVE TECHNIQUE UTILIZING FRCM SYSTEM IN STRENGTHENING RC BEAMS IN SHEAR

2018 ◽  
Vol 5 (1) ◽  
Author(s):  
Tadesse Wakjira ◽  
Usama Ebead
Keyword(s):  
Concrete Cover ◽  
Shear Capacity ◽  
Rc Beams ◽  
Test Results ◽  
Effective Technique ◽  
Near Surface ◽  
Test Parameters ◽  
Different Types ◽  
A New Technique ◽  
Fabric Reinforced Cementitious Matrix

This paper presents the efficacy of a new technique of fabric reinforced cementitious matrix (FRCM) for the strengthening of shear deficient reinforced concrete (RC) beams. This technique involves embedding the FRCM composites in the concrete cover and is referred to as “near surface embedded” FRCM (NSE-FRCM) technique. Five (5) medium scale rectangular RC beams of width × depth × length of 150 × 330 × 2100 mm were constructed and tested under displacement controlled with three-point loading. One beam was kept unstrengthen as a control specimen whereas the other four beams were strengthened with different types and configurations of the NSE-FRCM system. The test parameters were: (a) geometric configuration (intermittent strips of NSE-FRCM versus full NSE-FRCM plate), and (b) fabric types (carbon versus glass fabrics). The test results indicated that the NSE-FRCM technique can successfully be used to significantly enhance the shear capacity of the strengthened beams. The strengthened specimens exhibited an average enhancement in the shear capacity of 62% over the unstrengthen beam. The full NSE-FRCM plate showed higher enhancement in the shear strength compared to that for the intermittent NSE-FRCM configuration. Moreover, the specimens strengthened with carbon FRCM showed higher shear capacity compared to that with glass FRCM counterparts.

scholarly journals FORMULASI DAN UJI STABILITAS FISIK SEDIAAN MASKER GEL PEEL-OFF EKSTRAK ETANOL DAUN MIANA (Coleus Scutelleroides (L.) Benth.) DENGAN BERBAGAI BASIS

2021 ◽  
Vol 4 (1) ◽  
pp. 36
Author(s):  
Indriyani Arman,Hosea Jaya Edy, Karlah L.R Mansauda
Keyword(s):  
Physical Stability ◽  
Ethanol Extract ◽  
Homogeneity Test ◽  
Adhesion Test ◽  
Physical Quality ◽  
Test Parameters ◽  
Different Types ◽  
Time Test ◽  
Dispersion Test ◽  
The Stability

AbstractMiana leaves (Coleus Scutelleroides (L.) Benth.) contained flavonoid compounds that has antioxidants properties. This study aimed to formulate peel-off gel mask ethanol extract from Miana leaves became peel-off gel mask that is physically stable and to knows the type of base that form a formulation with good physical quality based on the test parameters of physical properties and the stability of preparation. Formulation  of peel-off gel mask ethanol extract of miana leaves used three different types of base, they are HPMC, Carbopol, and Na.CMC. Each formula is differentiated based on base of concentration which were HPMC 4%, carbopol 1%, and Na.CMC 3%. Evaluation to predict the physical stability of the preparation included organoleptic test, homogeneity test, pH test, dispersion test, adhesion test and dry time test. In stability test, each formula is placed at temperature 27 oC for 28 days and made observation on the 1st, 7th, 14th, 21th, and 28th day. Based on the result, the ethanol extract of Miana leaves can be formulated into a peel-off mask and formulation with HPMC and Carbopol base has a good physical quality and physically stable compared to Na.CMC base.Keywords: Miana Leaves, Peel-Off Gel Mask, Stability Teh  AbstrakDaun Miana (Coleus Scutelleroides (L.) Benth.) memiliki kandungan senyawa flavonoid yang berkhasiat sebagai antioksidan. Penelitian ini bertujuan untuk memformulasikan ekstrak etanol daun Miana menjadi masker gel peel-off yang stabil secara fisik serta mengetahui jenis basis yang membentuk formulasi sediaan masker dengan mutu fisik yang baik berdasarkan parameter uji sifat fisik dan stabilitas sediaan. Formulasi sediaan masker gel peel-off  ekstrak etanol daun Miana dibuat dengan menggunakan tiga jenis basis yang berbeda yaitu HPMC, karbopol, dan Na.CMC. Masing-masing formula dibedakan berdasarkan basis konsentrasi yaitu HPMC 4%, karbopol 1%, dan Na.CMC 3%. Evaluasi yang dilakukan terhadap stabilitas fisik sediaan masker gel peel-off meliputi uji organoleptis, uji homogenitas, uji pH, uji daya sebar, uji daya lekat, dan uji waktu mengering. Uji stabilitas dilakukan pada suhu kamar (27 oC) selama 28 hari dan dilakukan pengamatan pada hari ke 1, 7, 14, 21, dan 28. Hasil uji stabilitas fisik sediaan masker gel peel-off ekstrak etanol daun Miana dapat diformulasikan dalam bentuk sediaan masker gel peel-off , dan formula masker dengan basis HPMC dan karbopol memiliki mutu fisik yang baik dan stabil secara fisik dibandingkan dengan basis Na.CMC.Kata kunci: Daun Miana, Masker gel peel-off, Uji Stabilitas.

scholarly journals Comparative Analysis of Diagnostic Plague Antiphage Sera Received from Producers of Different Types

2010 ◽  
pp. 58-61
Author(s):  
T. V. Alenkina ◽  
G. G. Krasichkov ◽  
G. M. Fomina ◽  
O. A. Lobovikova ◽  
N. P. Mironova ◽  
...  
Keyword(s):  
Comparative Analysis ◽  
Physicochemical Properties ◽  
Manufacturing Process ◽  
Specific Activity ◽  
Experimental Series ◽  
Raw Material ◽  
Commercial Preparation ◽  
Test Parameters ◽  
Different Types

Manufacturing process of ovine hyperimmune sera against Pokrovskaya plague bacteriophage was worked out. Their stability in the process of storage was studied. Sera received were used as raw material to produce three experimental series of diagnostic plague antiphage ovine dry serum. Physicochemical properties, specific activity and specificity of the developed preparation were evaluated in comparison with similar commercial preparation produced from the equine serum. Similarity of all test parameters was revealed that enabled to recommend diagnostic plague antiphage ovine serum for application.

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