Angular Parameter for Characterizing Road Surface Microtexture

2000 ◽  
Vol 1723 (1) ◽  
pp. 66-72 ◽  
Author(s):  
Minh-Tan Do ◽  
Hassan Zahouani ◽  
Roberto Vargiolu
Keyword(s):  
Profile Analysis ◽  
Road Surface ◽  
Skid Resistance ◽  
Analysis Program ◽  
Simple Method ◽  
Coarse Aggregates ◽  
The Difference ◽  
Tire Friction ◽  
Tactile System

Development of a device for measuring road surface microtexture and the determination of a microtexture parameter related to wet road/tire friction are discussed. A laser autofocus system was selected from existing devices. The required characteristics were defined from consideration of the contact between wet roads and tires. The autofocus principle is presented briefly, and comparison is made with a tactile system. The microtexture parameter, called the theta parameter, is defined from the useful parts of the texture profiles, that is, those in contact with the tire. It characterizes relative positions of profile peaks. A simple method was proposed to define the peaks. The profile analysis program is presented briefly. Relevance of the theta parameter was validated on surfaces composed of coarse aggregates with planar exposed faces. The specimens were polished using a projection method to emphasize the microtexture contrast between surfaces. Friction was measured using a skid resistance tester (SRT) pendulum. Profiles were measured using both laser and tactile systems. Characteristics of profiles are given. The statistical distribution of theta values obtained on a profile may be described by an exponential function. Close agreement was found between theta values obtained from laser and tactile profiles, values from laser profiles being somewhat lower. The difference is attributed to profile length. Fair correlation was found ( r2 > 0.80) between theta values and SRT friction, and similar tendencies were observed from laser and tactile data.

scholarly journals Interfacial Tension Sensor for Low Dosage Surfactant Detection

2021 ◽  
Vol 5 (1) ◽  
pp. 9
Author(s):  
Piotr Pawliszak ◽  
Bronwyn H. Bradshaw-Hajek ◽  
Christopher Greet ◽  
William Skinner ◽  
David A. Beattie ◽  
...  
Keyword(s):  
Interfacial Tension ◽  
Microfluidic Device ◽  
Profile Analysis ◽  
Simple Method ◽  
Bubble Generation ◽  
Flotation Process ◽  
Line Measurement ◽  
Tension Sensor ◽  
Low Dosage

Currently there are no available methods for in-line measurement of gas-liquid interfacial tension during the flotation process. Microfluidic devices have the potential to be deployed in such settings to allow for a rapid in-line determination of the interfacial tension, and hence provide information on frother concentration. This paper presents the development of a simple method for interfacial tension determination based on a microfluidic device with a flow-focusing geometry. The bubble generation frequency in such a microfluidic device is correlated with the concentration of two flotation frothers (characterized by very different adsorption kinetic behavior). The results are compared with the equilibrium interfacial tension values determined using classical profile analysis tensiometry.

Wet Skid Resistance of Car and Truck Tires

1974 ◽  
Vol 2 (2) ◽  
pp. 102-116 ◽  
Author(s):  
A. Dijks
Keyword(s):  
Surface Texture ◽  
Road Surface ◽  
Skid Resistance ◽  
Test Results ◽  
Side Force ◽  
Force Coefficients ◽  
Truck Tires ◽  
Braking Force ◽  
Wet Skid Resistance

Abstract Two test trailers for measuring tire characteristics are described. One of the trailers is specially built for testing car tires and can steer, camber, and brake the test tire. This trailer is provided with a five component measuring hub. The second trailer, for testing truck tires, is restricted to braking only. Braking forces are measured with a dynamometer. The determination of peak and locked wheel braking force coefficients is discussed. In addition, for car tires, a method for obtaining side force coefficients is given. Test results are given for both car and truck tires showing the influence of road surface texture, speed, and tread depth on skid resistance, and the results are compared.

scholarly journals Characteristics of a Tire Friction and Performances of a Braking in a High Speed Driving

2014 ◽  
Vol 6 ◽  
pp. 260428 ◽  
Author(s):  
Yumrak Oh ◽  
Hoguen Lee
Keyword(s):  
Coefficient Of Friction ◽  
High Speed ◽  
Skid Resistance ◽  
Conservation Of Energy ◽  
Driving Speed ◽  
The Coefficient Of Friction ◽  
Braking Distance ◽  
The Difference ◽  
Tire Friction ◽  
Safe Road

The goal of pavement is to deliver the fine roughness and the safe road surface to traffic. It requires a secured and comfortable surface using the controlled speed of road. Through adjusting driving speed, skid resistance can be altered in one of the performances of the pavement surface. In high speed driving, there might be a certain level of risk, not in the same level as the proposed roads. Hence, this study first analyzes the speed equation under a consideration of a braking distance and then suggests the friction coefficient in high speed driving with the principle of conservation of energy. If we accept simply that the coefficient of friction is independent of speed, the difference between analysis and test value for braking distance is greatly generated. Therefore we have to analyze the coefficient of friction as an exponential function of braking speed of a vehicle.

scholarly journals P1199THE IMPORTANCE OF DETERMINING ALPHA-2-MACROGLOBULIN CONCENTRATITON IN PATIENTS ON PERITONEAL DIALYSIS

2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Marko Baralic ◽  
Ana Bontic ◽  
Jelena Pavlovic ◽  
Mirjana Lausevic ◽  
Selena Gajic ◽  
...  
Keyword(s):  
Peritoneal Dialysis ◽  
Covalent Binding ◽  
Cross Sectional Study ◽  
Cross Sectional ◽  
Simple Method ◽  
Partial Denaturation ◽  
The Difference ◽  
And Function ◽  
Relationship Of

Abstract Background and Aims To determine the concentration of Alpha-2-macroglobulin (α2M) and its activity in patients treated with peritoneal dialysis (PD) and healthy subjects (H). Method a cross-sectional study included 50 PD and 30 H, in which the concentration of active α2M molecules was determined. The measurement is based on covalent binding of α2M and trypsin and zymography with gelatin incorporated into the electrophoretic gel. Results The intensity of proteolytic bands seen with native α2M was analyzed in relation to the concentration of α2M in patients with PD with less and / or more than three peritonitis. Linear dependence was only visible in the case of the upper range, which originates from the intact α2M-trypsin complex. The highest coefficient of variation is calculated for the smallest α2M concentration (4.2%). The signal intensities originating from α2M (H) were higher compared to PD, with the PD group being lower in patients with higher peritonitis, and the difference was more pronounced as concentration increased, resulting in a lower slope of dependence. The proposed method can reliably measure the amount of α2M originating in a group H, while the quantification of α2M in PD groups that may have structurally altered α2M can be seen more for condition estimation than for accurate measurements. The zymographic test in this experiment allows us to investigate the relationship of the concentration, structure and function of α2M in different pathological conditions, as well as in the presence of modifying agents that can accompany them. Conclusion A simple method for the determination of α2M concentration and function by zymography has been developed, which can be used to examine residual α2M activity after partial denaturation or structural modification due to disease.

Simplified Determination of Fibrinogen Subfractions by Glycine

1979 ◽  
Author(s):  
S. Sasaki ◽  
K. Kito
Keyword(s):  
Molecular Weight ◽  
Ionic Strength ◽  
Human Plasma ◽  
Gel Electrophoresis ◽  
Biological Properties ◽  
Strength Analysis ◽  
Simple Method ◽  
Molecular Fraction ◽  
The Difference

Although it has been suggested by some investigators that human plasma fibrinogen is composed of two or more subfractions, no simple method of determining these fractions individually has been available for clinical use. We found that precipitation by glycine at certain ionic strength was suitable for this purpose. One volume of human plasma was added to 10 volume of 2.3 M glycine solution of varying ionic strength. Analysis of the precipitates obtained at various Ionic strength by means of SDS-gel electrophoresis gave the following results: The precipitate obtained at ionic strength 0.2 gave single band. Its molecular weight was 360,000, clottability 85%. The supernatant was devoid of this fraction. The precipitate obtained at ionic strength 1.4 gave two banda corresponding to molecular weight of 360,000 and 325,00O respectively. The clottability of the precipitate was 85%. The supernatant contained no significant amount of clottable protein. It is therefore possible to determine the concentrations of high molecular fraction of fibrinogen and of total fibrinogen in plasma using the precipitate at ionic strength 0.2 and the precipitate at ionic strength 1.4 respectively. The difference of the two values gives the concentration of low molecular fraction of fibrinogen. Biological properties of the two fractions were also studied.

6Li Atom Percentage Determination by Atomic Absorption–Emission Spectrometry Using a Natural Lithium Hollow Cathode Lamp

2009 ◽  
Vol 63 (8) ◽  
pp. 971-973 ◽  
Author(s):  
Ejaz UR Rehman ◽  
Shakeel UR Rehman ◽  
Shafaat Ahmed
Keyword(s):  
Atomic Absorption ◽  
Hollow Cathode ◽  
Calibration Curve ◽  
Absorption Spectrometry ◽  
Atomic Emission ◽  
Emission Spectrometry ◽  
Simple Method ◽  
Hollow Cathode Lamp ◽  
The Difference

A simple method has been developed for the determination of 6Li atom % using combined atomic emission–absorption spectrometry employing a commonly available natural lithium hollow cathode lamp. Unlike in previous practice, there is no need for specially fabricated and high cost 6Li and 7Li monoisotopic lamps in this method. The method requires adjustment of total lithium contents of the sample, i.e., 6Li + 7Li, to 2 μg-mL−1 based upon atomic emission spectroscopy (AES) ( Caes) against a 2 μg-mL−1 natural lithium standard. The concentration of the sample was then analyzed by atomic absorption spectroscopy (AAS) measurements ( Caas). The difference between the concentration measured by AES and AAS, i.e., Caes — Caas, was calculated. The magnitude of the difference was found to be a function of 6Li fraction in the sample. A calibration curve was constructed by plotting 6Li atom % versus [( Caes — Caas)/ Caes] X 100. 6Li atom % of an unknown sample can be evaluated by putting its [( Caes — Caas)/ Caes] X 100 value in the calibration curve. The method is fast, convenient, and precise.

Development of a simple method for the determination of single nucleotide polymorphisms

2010 ◽  
Vol 34 (8) ◽  
pp. S75-S75
Author(s):  
Weifeng Zhu ◽  
Zhuoqi Liu ◽  
Daya Luo ◽  
Xinyao Wu ◽  
Fusheng Wan
Keyword(s):  
Single Nucleotide Polymorphisms ◽  
Nucleotide Polymorphisms ◽  
Simple Method ◽  
Single Nucleotide

FRACTIONAL DETERMINATIONS OF URINARY 17-KETOSTEROIDS IN HYPEREMESIS GRAVIDARUM

1962 ◽  
Vol 41 (1) ◽  
pp. 123-128 ◽  
Author(s):  
Pentti A. Järvinen ◽  
Sykkö Pesonen ◽  
Pirkko Väänänen
Keyword(s):  
Hyperemesis Gravidarum ◽  
First Trimester ◽  
Control Group ◽  
Before And After ◽  
Daily Urine ◽  
First Trimester Of Pregnancy ◽  
The Difference

ABSTRACT The fractional determination of 17-ketosteroids in the daily urine was performed in nine cases of hyperemesis gravidarum and in four control cases, in the first trimester of pregnancy both before and after corticotrophin administration. The excretion of total 17-KS is similar in the two groups. Only in the hyperemesis group does the excretion of total 17-KS increase significantly after corticotrophin administration. The fractional determination reveals no difference between the two groups of patients with regard to the values of the fractions U (unidentified 17-KS), A (androsterone) and Rest (11-oxygenated 17-KS). The excretion of dehydroepiandrosterone is significantly higher in the hyperemesis group than in the control group. The excretion of androstanolone seems to be lower in the hyperemesis group than in the control group, but the difference is not statistically significant. The differences in the correlation between dehydroepiandrosterone and androstanolone in the two groups is significant. The high excretion of dehydroepiandrosterone and low excretion of androstanolone in cases of hyperemesis gravidarum is a sign of adrenal dysfunction.

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