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Tytuł:
A method for the estimation of sideslip angle for a vehicle equipped with a one-antenna GPS measuring system for steady state movement
Autorzy:
Pieniążek, Wiesław
Wolak, Stanisław
Janczur, Robert
Powiązania:
https://bibliotekanauki.pl/articles/263758.pdf
Data publikacji:
2019
Wydawca:
Sieć Badawcza Łukasiewicz. Przemysłowy Instytut Motoryzacji
Tematy:
sideslip angle
heading angle
yaw angle
yaw rate
GPS receiver signals
Opis:
One-antenna GPS systems present no possibility for the direct determination of vehicle slip angle. This is an easy task for dual antenna systems; however, many users have this kind of apparatus. In this paper, a method of estimation of this parameter, which is important for the estimation of vehicle steerability factors, is proposed (e.g. TB factor calculated on the basis of data from input test [8]). The method is based on two parameters measured by a one-antenna GPS system; these are the heading angle created from the Doppler channel coming directly from the GPS engine, and the yaw rate measured by an IMU device integrated and cooperating with the GPS engine. The sideslip angle which was calculated according to the proposed method is compared with an equivalent angle calculated on the basis of data from a non-slip measurement of velocity components for selected point of vehicle acquired using. The presented method is illustrated with examples from real tests. In the author’s opinion, the sideslip angle calculated with the application of measurement data obtained from a one-antenna GPS device could be used in practice. From comparison with another upper mentioned method, it follows that the differences between average values of sideslip angles obtained from both considered methods is not greater than 8%.
Źródło:
Archiwum Motoryzacji; 2019, 84, 2; 137-146
1234-754X
2084-476X
Pojawia się w:
Archiwum Motoryzacji
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Significance of the receding contact angle in the determination of surface free energy
Autorzy:
Chodkowski, Michał Paweł
Powiązania:
https://bibliotekanauki.pl/articles/2079958.pdf
Data publikacji:
2018
Wydawca:
Uniwersytet Marii Curie-Skłodowskiej. Wydawnictwo Uniwersytetu Marii Curie-Skłodowskiej
Tematy:
receding contact angle
equilibrium contact angle
Tadmor’s contact angle
CAH
surface free energy
Opis:
Surface free energy measurements of solids are a very important issue in various fields of science. Many functional, chemical and physical properties of a given material depend on its surface free energy. The basic method of the surface free energy determination are the contact angle measurements. There are several empirical methods useful to calculate the surface free energy of solids. They are based on the measurements of the contact angle of liquids with the defined surface tension. The aim of this paper is to examine the significance of the receding contact angle measurements in the determination of surface free energy of solids.
Źródło:
Annales Universitatis Mariae Curie-Skłodowska, sectio AA – Chemia; 2018, 73, 1; 61-80
2083-358X
Pojawia się w:
Annales Universitatis Mariae Curie-Skłodowska, sectio AA – Chemia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A dynamic angle metrology system based on fibre-optic gyroscope and rotary table
Autorzy:
Chen, Lei
Zhou, Yilan
Zhang, Dengwei
Shu, Xiaowu
Liu, Cheng
Powiązania:
https://bibliotekanauki.pl/articles/220999.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
circular grating angle encoder
fibre-optic gyroscope
dynamic angle metrology
Opis:
Dynamic angle measurement (DAM) plays an important role in precision machining, aerospace, military and artificial intelligence. Because of its advantages including high sensitivity, solid state and miniaturization, fibre-optic gyroscope (FOG) has great application prospects in the field of DAM. In this paper, we propose a dynamic angle metrology method based on FOG and a rotary table to evaluate the DAM accuracy with FOG. The system synchronously collects data from the FOG and rotary table, and analyses the DAM accuracy of the FOG for different sway conditions compared with that of the angle obtained from the rotary table. An angle encoder in the rotary table provides absolute or incremental angular displacement output with angular displacement measurement accuracy of 10′′ (0:0028°) and angular displacement repeat positioning accuracy of 3′′ (0:00083°), and can be used as an angle reference. The experimental results show that the DAM accuracy of the FOG is better than 0:0028° obtained with the angular encoder, and the absolute DAM accuracy of the FOG is better than 0:0048° for given conditions. At the same time, for the multi-path signal synchronization problem in the metrology field, this paper proposes a signal delay measurement method combining test and algorithm procedures, which can control a delay within 25 μs.
Źródło:
Metrology and Measurement Systems; 2019, 26, 3; 497-504
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The analysis of the solar power plant performance in temperate climate
Autorzy:
Zdyb, A.
Dragan, P.
Jaremek, A.
Powiązania:
https://bibliotekanauki.pl/articles/105126.pdf
Data publikacji:
2018
Wydawca:
Politechnika Rzeszowska im. Ignacego Łukasiewicza. Oficyna Wydawnicza
Tematy:
photovoltaics
grid connected solar plant
photovoltaic performance
inclination angle
tilt angle
Opis:
Due to gradual depletion of fossil fuels resources and emission of harmful chemicals accompanying the combustion process, the interest in alternative energy sources still increases. Among many kinds of alternative sources, solar radiation is very special because of its wide availability and large technical potential. Photovoltaic systems providing the electric energy are used in many countries. The most important part of photovoltaic system is a module, which parameters (e.g. efficiency, rated power, temperature coefficients of power and efficiency, short circuit current, open circuit voltage) are determined in laboratory tests under Standard Test Conditions (STC: 25°C, 1,000 W/m2 , air mass 1.5). However, in real outdoor conditions the modules exhibit lower efficiency since local climate influences their performance and different external factors generate energy losses in the whole system. The aim of this work is the performance analysis of a solar power plant connected to the grid, which total rated power is 2.985 MW and it works in temperate climate in eastern Poland. Insolation in the location was estimated according to Solargis data and the role of the modules tilt angle, of which the value is non-typical for the considered location was studied. The tilt angle smaller than optimal angle allows increasing the amount of the solar radiation collected in the summer period. The electric energy production based on the inverters data in 2016 and 2017 as well as yearly yield are presented. The results are compared to data coming from other solar power plants, also located at high latitude.
Źródło:
Czasopismo Inżynierii Lądowej, Środowiska i Architektury; 2018, 65, 1; 73-79
2300-5130
2300-8903
Pojawia się w:
Czasopismo Inżynierii Lądowej, Środowiska i Architektury
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Anthropometric, body composition and behavioural predictors of bioelectrical impedance phase angle in Polish young adults - preliminary results
Autorzy:
Skrzypek, M.
Szponar, B.
Drop, B.
Panasiuk, L.
Malm, M.
Powiązania:
https://bibliotekanauki.pl/articles/2085363.pdf
Data publikacji:
2020
Wydawca:
Instytut Medycyny Wsi
Tematy:
young adults
bioelectrical impedance
phase angle
body composition analyzer
phase angle predictors
Opis:
Introduction and objective. Bioimpedance analysis (BIA) phase angle (PhA) is an index of the integrity of cells and cellular membranes. The aim of the study was identification of behavioural and anthropometric predictors of PhA in a group of young adults. Materials and method. A cross-sectional observational study of health behaviours, anthropometric indicators and body composition assessed by the BIA method was conducted in a group of Polish young adults (n=92) aged 18 – 24 (mean – 19.33, STD – 0.915). Behavioural variables included: level of physical activity, eating behaviours and nutritional knowledge. Body composition was analysed by means of BIA phase-sensitive 8-electrode medical SECA mBCA 525 device. Results. The mean PhA value in the examined cohort was 6.38±0.75 (males – 7.22±0.72; females – 6.13±0.57). Males also showed higher statistically significant other body composition indices, excluding fat mass. The multiple regression model, including anthropometric variables and gender, which explained the effect of these variables on PhA, occurred to be significant (p<0.0000) and allowed explanation of the 82.49% of PhA variability. PhA was significantly predicted from body mass index (BMI), absolute fat mass, visceral adipose tissue value, skeletal muscle mass value and gender. The regression model, including behavioural predictors and gender, allowed explanation of the lower percentage of PhA variability (42.75%; p<0.0000) and included general intensity of health behaviours, level of nutritional knowledge, and gender. A regression model which would consider simultaneously anthropometric and behavioural variables could not be constructed. Conclusions. In the examined cohort, anthropometric and body composition variables showed a stronger predictive value with respect to PhA, compared to behavioural variables.
Źródło:
Annals of Agricultural and Environmental Medicine; 2020, 27, 1; 91-98
1232-1966
Pojawia się w:
Annals of Agricultural and Environmental Medicine
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The study of correlation between forward head posture and neck pain in Iranian office workers
Autorzy:
Nejati, Parisa
Lotfian, Sara
Moezy, Azar
Nejati, Mina
Powiązania:
https://bibliotekanauki.pl/articles/2177383.pdf
Data publikacji:
2015-03-12
Wydawca:
Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
Tematy:
neck pain
craniovertebral angle
forward head posture
high thoracic angle
office employee
Opis:
Introduction Factors such as prolonged sitting at work or improper posture of head during work may have a great role in neck pain occurrence among office employees, particularly among those who work with computers. Although some studies claim a significant difference in head posture between patients and pain-free participants, in literature the forward head posture (FHP) has not always been associated with neck pain. Since head, cervical and thoracic postures and their relation with neck pain has not been studied in Iranian office employees, the purpose of this study was to investigate the relationship between some work-related and individual factors, such as poor posture, with neck pain in the office employees. Material and methods It was a cross-sectional correlation study carried out to explore the relationship between neck pain and sagittal postures of cervical and thoracic spine among office employees in forward looking position and also in a working position. Forty-six subjects without neck pain and 55 with neck pain were examined using a photographic method. Thoracic and cervical postures were measured using the high thoracic (HT) and craniovertebral (CV) angles, respectively. Results High thoracic and CV angles were positively correlated with the presence of neck pain only in working position (p < 0.05). In forward looking position, there was no statistically significant difference between the 2 groups (p > 0.05). Conclusions Our findings have revealed that office employees had a defective posture while working and that the improper posture was more severe in the office employees who suffered from the neck pain.
Źródło:
International Journal of Occupational Medicine and Environmental Health; 2015, 28, 2; 295-303
1232-1087
1896-494X
Pojawia się w:
International Journal of Occupational Medicine and Environmental Health
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Theoretical Model of the Influence of Textile Structure on Wetting Hysteresis
Model teoretyczny wpływu struktury tkaniny na jej histerezę zwilżania
Autorzy:
Bachurová, M.
Wiener, J.
Powiązania:
https://bibliotekanauki.pl/articles/234300.pdf
Data publikacji:
2013
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
real contact angle
apparent contact angle
contact angle hysteresis
textile structure
rzeczywisty kąt zwilżania
pozorny kąt zwilżania
histereza zwilżania
struktura tkaniny
Opis:
In our work we theoretically analysed the influence of textile structure on the hysteresis of wetting. The situation with current fabrics is complicated and the properties of fibers, yarns, and geometric arrangement also influence their wetting. The basis of the theoretical model is a simple plain weave fabric made from monofilaments. From this model we determined the real contact angle and apparent contact angle, and later we compared these values with results from the experimental measurement.
W pracy przeanalizowano pod względem teoretycznym wpływ struktury tkaniny na histerezę zwilżania. Właściwości włókien, przędz i układ geometryczny mają wpływ na zwilżanie tkanin. Podstawą modelu teoretycznego jest tkanina o splocie prostym wykonana z monofilamentów. Wyznaczono rzeczywisty i pozorny kąt zwilżania, a następnie porównano otrzymane wartości z wynikami pomiarów eksperymentalnych.
Źródło:
Fibres & Textiles in Eastern Europe; 2013, 2 (98); 80-83
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modal characterization of sandwich skew plates
Autorzy:
Pavan-Kumar, Dhotre
Srinivasa, Chikkol V.
Powiązania:
https://bibliotekanauki.pl/articles/2114835.pdf
Data publikacji:
2021
Wydawca:
Politechnika Białostocka. Oficyna Wydawnicza Politechniki Białostockiej
Tematy:
natural frequency
non-dimensional frequency parameter
antisymmetric laminate
fiber orientation angle
skew angle
Opis:
The current work focuses on the experimental and finite element free vibration studies of laminated composite sandwich skew plates. The comparison was made between the experimental values obtained by the Fast Fourier transform (FFT) analyzer and a finite el-ement solution obtained from CQUAD8 finite element of The MacNeal-Schwendler Corporation (MSC) / NASA STRucture Analysis (NAS-TRAN) software. The influence of parameters such as aspect ratio (AR) (a/b), skew angle (α), edge condition, laminate stacking sequence, and fiber orientation angle (θ°) on the natural frequencies of sandwich skew plates was studied. The values obtained by both the finite el-ement and experiment approaches are in good agreement. The natural frequencies increase with an increase in the skew angle for all giv-en ARs.
Źródło:
Acta Mechanica et Automatica; 2021, 15, 3; 143--153
1898-4088
2300-5319
Pojawia się w:
Acta Mechanica et Automatica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of the clinical and radiological parameters of vertebral rotation degree in children with idiopathic scoliosis
Porównanie klinicznych i radiologicznych parametrów określających stopień rotacji kręgów u dzieci ze skoliozą idiopatyczną
Autorzy:
Falkowska, Marta
Deja, Agata
Powiązania:
https://bibliotekanauki.pl/articles/1963085.pdf
Data publikacji:
2012
Wydawca:
Akademia Wychowania Fizycznego im. Bronisława Czecha w Krakowie
Tematy:
idiopathic scoliosis
Bunnell trunk rotation angle
scoliometer
axial vertebral rotation angle
Perdriolle method
Opis:
Background: Scoliosis is a spinal deformity that develops in three dimensions. The vetebral rotation degree is an important parameter used to diagnose and to assess scoliosis severity, to choose the treatment methods and also to monitor the course of the disease and rehabilitation effects.Aim: The aim of the study is to evaluate the relationship between the two parameters describing the vertebral rotation degree in children with idiopathic scoliosis, that is between the trunk rotation angle according to Bunnell and the axial rotation degree of apical vertebra described on the basis of the X-ray using the Perdriolle method.Material: 64 girls and 8 boys with idiopathic scoliosis.Methods: The trunk axial rotation angle according to Bunnell was evaluated in Adam’s test with the use of a scoliometer. To describe the axial rotation angle of the apical vertebra a posterior-anterior chest X-ray conducted in a standing position was used. The Perdriolle method with the help of a special ruler was used here.Results: It was revealed that generally in all curvatures there is a statistically significant dependence between the Bunnell trunk rotation angle and the Perdriolle axial rotation angle. Applying a division based on the type of curvature and the child’s age it was confirmed that there is a correlation between the variables for thoracic, thoracolumbar and lumbar curvatures as well as in children over the age of 10. The relationship between the Bunnell angle and the Perdriolle angle in children under 10 was not proved.Conclusions: A correlation between the Bunnell trunk rotation angle and the Perdriolle axial rotation angle in children with idiopathic scoliosis over the age of 10 is observed, and occurs both among primary and secondary curvatures. Using a scoliometer enables for a simple and fast description of the spine rotation and reduces x-ray exposure.
Wstęp: Skolioza to zniekształcenie kręgosłupa rozwijające się w trzech płaszczyznach. Stopień rotacji kręgów jest ważnym parametrem, którym posługujemy się przy rozpoznawaniu i ocenie zaawansowania skoliozy, przy wyborze metody leczenia, a także w celu monitorowania przebiegu choroby i efektów usprawniania. Cel pracy: Celem pracy jest ocena zależności między dwoma parametrami określającymi stopień rotacji kręgów u dzieci ze skoliozą idiopatyczną tj. między kątem rotacji tułowia wg Bunnella a kątem rotacji osiowej kręgu szczytowego wyznaczonym na podstawie zdjęcia RTG metodą Perdriolle’a. Materiał: 64 dziewczynki i 8 chłopców ze skoliozą idiopatyczną. Metody: Kąt rotacji tułowia wg Bunnella oceniano w teście Adamsa za pomocą skoliometru. Do wyznaczenia kąta rotacji osiowej kręgu szczytowego użyto zdjęć RTG kręgosłupa w projekcji przednio-tylnej wykonywanych w pozycji stojącej. Posłużono się przy tym metodą Perdriolle’a, używając specjalnej linijki. Wyniki: Wykazano, że ogółem dla wszystkich skrzywień istnieje istotna statystycznie zależność między kątem rotacji tułowia wg Bunnella i kątem rotacji osiowej Perdriolle’a. Stosując podział w zależności od typu skrzywienia i wieku dziecka potwierdzono korelację miedzy badanymi zmiennymi dla skrzywień piersiowych, piersiowo-lędźwiowych i lędźwiowych oraz dla dzieci powyżej 10 roku Ŝycia. Nie wykazano korelacji między kątem Bunnella a kątem rotacji osiowej Perdriolle’a w grupie dzieci do 10 roku Ŝycia. Wnioski: Związek pomiędzy kątem rotacji tułowia wg Bunnella a kątem rotacji osiowej Perdriolle’a występuje u dzieci ze skoliozami idiopatycznymi powyżej 10 roku Ŝycia i zależność ta dotyczy zarówno skrzywień pierwotnych, jak i wtórnych. Posługiwanie się skoliometrem pozwala na prostą, szybką ocenę rotacji kręgosłupa i ograniczenie ilości wykonywanych zdjęć rentgenowskich.
Źródło:
Medical Rehabilitation; 2012, 16(1); 9-14
1427-9622
1896-3250
Pojawia się w:
Medical Rehabilitation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of surface curvature on sessile droplet contact angle of nanofuids
Autorzy:
Cieśliński, J. T.
Krygier, K.
Powiązania:
https://bibliotekanauki.pl/articles/175339.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
contact angle
nanofluids
substrate curvature
Opis:
This paper deals with the change in contact angle of droplets for three nanofluids, i.e., water- Al2O3, water-TiO2 and water-Cu. Nanoparticles were tested at the concentration of 0.01, 0.1, and 1% by weight. Although dispersants were not used to stabilize the suspension, the solutions tested exhibited satisfactory stability. Ultrasonic vibration was used in order to stabilise the dispersion of the nanoparticles. Experimental measurements were performed for horizontal stainless steel (316) tube of three diameters, i.e., 1.6, 3 and 5 mm, and flat stainless steel plates. The results obtained show that the contact angle of tested nanofluids depends strongly on nanoparticle concentration as well as the curvature of the substrate.
Źródło:
Transactions of the Institute of Fluid-Flow Machinery; 2013, 125; 3-12
0079-3205
Pojawia się w:
Transactions of the Institute of Fluid-Flow Machinery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ultrasonographic assessment of articular cartilage of the femoral condyle in patients with an increased Q-angle
Ocena ultrasonograficzna chrząstki stawowej na kłykciach kości udowej u pacjentów ze zwiększonym kątem Q
Autorzy:
Kusiak, Maciej
Kawczyński, Adam
Powiązania:
https://bibliotekanauki.pl/articles/1032314.pdf
Data publikacji:
2018
Wydawca:
Medical Communications
Tematy:
Q-angle
cartilage
patellofemoral joint
Opis:
Introduction: The patella is a sesamoid for the quadriceps, which increases its power during knee extension and thus transfers considerable forces. The etiology of patellofemoral pain is multifactorial. In the absence of injury, the commonly accepted hypothesis is associated with increased compression of articulating surfaces. Aim: The aim of the study was to perform an ultrasound evaluation of the thickness of articular cartilage covering the medial and lateral femoral condyle in patients with an increased Q-angle. Materials and methods: The study included 26 women aged between 35 and 45 years. A total of 13 patients with Q >15° were included in the study group, and 13 patients with Q ≤15° were included in the control group. A goniometer was used for Q-angle measurement. The thickness of articular cartilage covering the medial and lateral femoral condyle of the femoral bone was measured using a HONDA HS-2200 ultrasound with a linear HLS-584M transducer. The Shapiro–Wilk test was used for the assessment of data distribution normality; the distribution was normal. The differences in the measured parameters were assessed with the ANOVA test for independent samples. The Bonferroni test was used for a multiple comparison. Results: The statistical analysis showed statistically significantly reduced thickness of articular cartilage on the lateral femoral condyle (p = 0.00) in the Q >15° group. No statistically significant differences were demonstrated for the thickness of articular cartilage on the medial femoral condyle (p = 0.47). Conclusions: The thickness of the articular cartilage on the lateral femoral condyle is lower than that of the medial femoral condyle in women aged between 35 and 45 years with the Q-angle >15°.
Wstęp: Rzepka jest dla mięśnia czworogłowego uda trzeszczką, która zwiększa siłę jego działania przy wyproście kolana i przenosi przez to znaczne siły. Pochodzenie bólu rzepkowo-udowego jest wieloczynnikowe. W przypadku braku urazu powszechnie przyjętą hipotezą dotyczącą etiologii bólu jest ta związana ze zwiększonym naciskiem na siebie powierzchni stawowych. Cel pracy: Celem niniejszej pracy była ocena ultrasonograficzna grubości chrząstki stawowej pokrywającej kłykieć przyśrodkowy i kłykieć boczny u osób ze zwiększonym kątem Q. Materiał i metody: W badaniu udział wzięło 26 kobiet w wieku pomiędzy 35. a 45. rokiem życia. Grupę badawczą stanowiło 13 osób z kątem Q >15°, a grupę kontrolną – 13 osób z kątem Q ≤15°. Do pomiaru kąta Q w stawie posłużono się goniometrem. Pomiar grubości chrząstki stawowej pokrywającej kłykieć przyśrodkowy i kłykieć boczny kości piszczelowej został przeprowadzony za pomocą ultrasonografu HONDA HS-2200 z sondą liniową HLS-584M. Do oceny normalności rozkładu danych zastosowano test Shapiro–Wilka i był on normalny. Do oceny różnic mierzonych parametrów wykorzystano test wariancji ANOVA dla prób niezależnych. Do porównania wielokrotnego posłużono się testem Bonferroniego. Wyniki: Przeprowadzona analiza statystyczna wykazała istotne statystycznie zmniejszenie grubości chrząstki stawowej na kłykciu bocznym kości udowej (p = 0,00) w grupie z kątem Q >15°. Nie wykazano istotnych statystycznie różnic w grubości chrząstki stawowej na kłykciu przyśrodkowym kości udowej (p = 0,47). Wnioski: U kobiet w wieku 35–45 lat z kątem Q >15° grubość chrząstki stawowej pokrywającej kłykieć boczny kości udowej jest mniejsza od grubości chrząstki stawowej na kłykciu przyśrodkowym.
Źródło:
Journal of Ultrasonography; 2018, 18, 74; 181-185
2451-070X
Pojawia się w:
Journal of Ultrasonography
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of Volume Drop on Surface Free Energy of Glass
Autorzy:
Rymuszka, Diana
Terpiłowski, Konrad
Hołysz, Lucyna
Powiązania:
https://bibliotekanauki.pl/articles/951384.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Marii Curie-Skłodowskiej. Wydawnictwo Uniwersytetu Marii Curie-Skłodowskiej
Tematy:
contact angle
surface free energy
Opis:
The aim of the research was to determine how the drop size affects the contact angle values and determine its optimal size for further contact angle measurements and comparison of the contact angle values measured for three probe liquids (water, formamide, diiodomethane) on the glass surface using the: sessile drop and tilting plate methods. Next, using the measured contact angles, the total surface free energy and its components were determined from the van Oss et al. (Lifshitz-van der Waals acid- base component, LWAB), Owens-Wendt, Neumann and contact angle hysteresis (CAH) approaches. The studies showed, that drop size is very important for contact angle measurements and consequently, for surface free energy estimation.
Źródło:
Annales Universitatis Mariae Curie-Skłodowska, sectio AA – Chemia; 2013, 68, 1-2
2083-358X
Pojawia się w:
Annales Universitatis Mariae Curie-Skłodowska, sectio AA – Chemia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Measurement of contact angle of copper-bearing shales using the captive bubble method
Autorzy:
Szyszka, D.
Powiązania:
https://bibliotekanauki.pl/articles/88887.pdf
Data publikacji:
2014
Wydawca:
Politechnika Wrocławska. Wydział Geoinżynierii, Górnictwa i Geologii. Instytut Górnictwa
Tematy:
contact angle
hydrophobicity
hydrophilicity
flotation
Opis:
This paper describes the measurement of contact angle of the natural surface of copper-bearing shales immersed in solutions of selected reagents of various concentrations using captive bubble method. It demonstrates that the copper-bearing shales coming from Legnicko-Głogwski Copper Region develop natural hydrophobic properties in surfactant (frother) solutions and its hydrophobicity decreases from 82⁰ contact angle in distilled water, 78⁰ in C4E1 solutions, 76⁰ in C4E2 solutions, to 75⁰ in dodecylphenol solutions. These data show that the addition of frother causes a decrease of shale hydrophobicity but it can reduce stability of the thin film between the grain and air bubble. It means that flotation of copper-bearing shales in the presence of frother will only be possible provided specific concentrations.
Źródło:
Mining Science; 2014, 21; 83-94
2300-9586
2353-5423
Pojawia się w:
Mining Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of contact angle measurement methods of liquids on metal alloys
Autorzy:
Terpiłowski, Konrad
Hołysz, Lucyna
Rymuszka, Diana
Banach, Robert
Powiązania:
https://bibliotekanauki.pl/articles/763967.pdf
Data publikacji:
2016
Wydawca:
Uniwersytet Marii Curie-Skłodowskiej. Wydawnictwo Uniwersytetu Marii Curie-Skłodowskiej
Tematy:
metal alloys
wettability
contact angle
Opis:
The paper presents the studies of metal wettability using two methods: the sessile droplet and immersion ones. Based on the measured contact angles, there was calculated apparent surface free energy from the acidic–basic approach and the contact angle hysteresis. The advancing contact angles measured using the immersion method exhibit a little higher values than those measured by the sessile droplet method. The application of the immersion method leads to obtaining higher contact angle hysteresis. Both methods give different values of contact angles but they can be applied independently for estimation of metal surface wettability.
Źródło:
Annales Universitatis Mariae Curie-Skłodowska, sectio AA – Chemia; 2016, 71, 1
2083-358X
Pojawia się w:
Annales Universitatis Mariae Curie-Skłodowska, sectio AA – Chemia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Metahydrophobicity and orthohydrophilicity tested in flotation of NaCl, KCl, KPF6 in their saturated aqueous solutions
Autorzy:
Drzymala, Jan
Dubiel, Malgorzata
Ratajczak, Tomasz
Powiązania:
https://bibliotekanauki.pl/articles/109910.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
flotation
contact angle
hydrophobicity
hydrophilicity
Opis:
Flotation tests of different size fractions of NaCl, KCl and KPF6 in their saturated aqueous solutions were performed in a 36 cm in height monobubble Hallimond tube. Also contact angle tests by means of sessile drops of saturated salt solution put on pressed discs of salts were carried out. The obtained sessile drop contact angles were equal to zero, pointing to a complete hydrophilicity (orthophilicity) of the investigated salts. In the case of NaCl and KCl, their orthohydrophilicity was confirmed by flotation tests and flotometric considerations because the entrainment factors, which take into account the maximum size of entrained particles and density of the salt as well as it solution, were similar to those of quartz and magnetite and equal to 0.11 mm. The entrainment factor for KPF6  was equal to 0.18 mm and was greater than that of NaCl and KCl indicating certain natural flotation of this salt caused by some flotational hydrophobicity called in this paper metahydrophobicity. The metahydrophobicity of KPF6   was confirmed by flotation results. In the case of KPF6 the maximum yields of the same size particles were the highest, even though the density of this salt was greater than that of NaCl and KCl. Also, the first order kinetic constants were always the greatest for KPF6. Further flotometeric calculation based on the balance of forces involved in flotation indicated that the estimated contact angle of KPF6 was about 8 º assuming static flotation, and 7 º for dynamic flotation, while for NaCl and KCl was below 5 º . It means that during flotation test orthohydrophilic NaCl and KCl are only entrained while for metahydrophobic KPF6 there is mostly entrainment and some flotation.
Źródło:
Physicochemical Problems of Mineral Processing; 2019, 55, 5; 1141-1147
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 531

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