Evaluation of microfiber release from jeans: the impact of different washing conditions

Microplastic particles are a burgeoning population crisis in the marine environment. This research examines the emission of microfibers from three different jeans (garments) during domestic washing. The jeans types, washing temperature, washing duration, spin speed, detergent types, and addition of conditioner are the main factors for this research work. The average length and diameter of the microfibers for the 100% PET jeans (jeans-P) has 7800 ± 4000 μm and 11.9±3.2 μm and for polyester/cotton jeans (jeans-PB) has 4900 ± 2200 μm 17.4±4.8 μm, respectively. The maximum microfiber released was observed in the rigorous washing treatment (90 min, 60°C, 1400 rpm, powder detergent with the presence of conditioner). The surmised number of microfibers discharged from the 1 kg wash load of jeans-P was calculated within the extent of 2300000–4900000 microfibers, and it is varied by the washing treatments.

Effects of Concentration and Spin Speed on the Optical and Electrical Properties of Silver Nanowire Transparent Electrodes

In this paper, silver nanowires (AgNWs) with a diameter of 40 nm and a length of 45 μm were dispersed into an ethanol solution to prepare AgNW solutions with concentrations of 1, 2, and 3 mg/mL, respectively. The AgNW solutions were then deposited on a glass substrate using spin-coating at 1000, 2000, and 3000 rpm for 45 s, respectively, to prepare transparent electrodes. The results showed that the distribution of AgNWs on the substrate increased in density with the increase in the AgNW solution concentration and the decrease in spin speed. The effect of concentration on the distribution of AgNWs was greater than that of the spin speed. The transmittance of each electrode was between 84.19% and 88.12% at 550 nm, the average sheet resistance was between 20.09 and 358.11 Ω/sq, the highest figure of merit (FoM) was 104.42, and the lowest haze value was 1.48%. The electrode prepared at 1000 rpm with a concentration of 2 mg/mL and that prepared at 3000 rpm with a concentration of 3 mg/mL were very similar in terms of the average sheet resistance, transmittance at 550 nm, FoM, and haze value; thus, these two electrodes could be considered equivalent. The haze value of the electrode was positively correlated with the spin speed at low concentration, but that relationship became inverse as the concentration rose. For the AgNWs used in this experiment with an aspect ratio of 1125, the concentration of the AgNW solution should reach at least 2 mg/mL to ensure that the FoM of the electrode is greater than 35.

Correlations Between Stroke Structural Characteristics and Stroke Effect of Young Table Tennis Players

Background: A perfect stroke is essential for winning table tennis competition. A perfect stroke is closely related to reasonable stroke structure, which directly affects the stroke effect. The main purpose of this study was to examine the correlations between the structural characteristics of stroke and the stroke effect. Methods: Forty-two young table tennis players were randomly selected from China Table Tennis College (M age = 14.21 ± 2.13; M height = 1.57 ± 0.14 m; M weight = 46.05 ± 6.52 kg, right-hand racket, shake-hands grip, no injuries in each joint of the body). The high-speed infrared motion capture system was used to collect the data of stroke structural characteristics, and the high-speed camera was used to measure the spin speed of the stroke. The influence of striking structural characteristics on striking effect was examined.Results: The time duration of backswing and forward motion were significantly correlated with ball speed (r = -0.403, p < 0.01; r = -0.390, p < 0.01, respectively) and spin speed (r = -0.244, p = 0.027; r = -0.369, p < 0.01, respectively). The linear velocity of right wrist joint was positively correlated with ball speed (r = 0.298, p < 0.01) and spin speed (r = 0.238, p = 0.031). The angular velocity of right elbow joint and right hip joint were positively correlated with ball speed (r = 0.219, p = 0.013; r = 0.427, p < 0.01, respectively) and spin speed (r = 0.172, p = 0.048; r = 0.277, p = 0.012, respectively). The angular velocity of right knee joint had a significantly negative correlation with placement (r = -0.246, p = 0.026). The angular velocity of right ankle joint had a significantly positive correlation with the ball speed (r = 0.443, p < 0.01).Conclusions: The time allocation of the three phases of backspin forehand stroke had an important impact on stroke effect, especially the ball speed and spin speed. The ball speed of the stroke was mainly affected by the translation of the right wrist joint. The spin speed of the stroke was mainly affected by the translation of the right wrist joint. The placement of the stroke was mainly affected by the rotation of the right knee joint.

Formation and Stability of Smooth Thin Films with Soft Microgels Made of Poly(N-Isopropylacrylamide) and Poly(Acrylic Acid)

In this work, soft microgels of Poly(N-Isopropylacrylamide) (PNIPAm) at two different sizes and of interpenetrated polymer network (IPN) composed of PNIPAm and Poly(Acrylic Acid) (PAAc) were synthesized. Then, solutions of these different types of microgels have been spin-coated on glass substrates with different degrees of hydrophobicity. PNIPAm particles with a larger diameter form either patches or a continuous layer, where individual particles are still distinct, depending on the dispersion concentration and spin speed. On the other, PNIPAm particles with a smaller diameter and IPN particles form a continuous and smooth film, with a thickness depending on the dispersion concentration and spin-speed. The difference in morphology observed can be explained if one considers that the microgels may behave as colloidal particles or macromolecules, depending on their size and composition. Additionally, the microgel size and composition can also affect the stability of the depositions when rinsed in water. In particular, we find that the smooth and continuous films show a stimuli-dependent stability on parameters such as temperature and pH, while large particle layers are stable under any condition except on hydrophilic glass by washing at 50 °C.

Serve Ball Trajectory Characteristics of Different Volleyballs and Their Causes

Volleyball is a sport that starts with a serve, so effective service is essential to win the game. The trajectory of the ball is complicatedly affected by the fluid force, which depends on the speed, spin speed, and panel shape. To understand the aerodynamic characteristics of the ball and to propose an ideal serve method, we measured the fluid force and flight trajectory. The fluid force applied to the ball was measured at a wind speed of 4–30 m/s in the wind tunnel. The fluid force on the ball was strongly dependent on the ball type and orientation of the panel. In the flight trajectory measurement, the trajectory of the ball was measured using a high-speed camera under controlled speed and spin speed using a shotting machine. The effect of the panel orientation shown by the fluid force measurement was consistent with the results of the trajectory analysis, clarifying the importance of the panel orientation in serving.

Ambient Energy Harvesting of Piezoelectric ZnO Thin Film Dependence of Spin Speed and Annealing Temperature

This research deals with ambient energy harvesting by using zinc oxide thin film. The objectives of this thesis are to prove the ZnO film as a piezoelectric material can produce electric when vibration is applied and determine its optimal voltage. The thesis describes the sol gel spin coating technique to fabricate zinc oxide thin film. Zinc acetate dehydrate, absolute ethanol and diethanolamine were used in this thesis to act as sol gel precursor. Sol gel was coated on glass slide which wrapped by aluminum foil. The thin film was formed after preheating and annealing. The thin film was characterized by X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), Photoluminescence spectroscopy (PL) and Ultraviolet-visible spectroscopy (UV-Vis) as well as analyzed using vibration technique. From XRD results, the films were preferentially diffracted at around 65° which corresponding to (1 1 2) diffraction phase. From FESEM results, it was observed that when the spin speed was increased at same annealing temperature, the thickness was also decreased. When the annealing temperature was increased at same spin speed, both grain size and thickness were increased. From the PL results, there was only film with spin speed of 2000 rpm and annealing temperature of 300 °C had slightly left wavelength which was 380 nm. Annealing temperature would affect only the intensity of PL wavelength. From the results of UV-Vis, it was observed that when the spin speed was increased at same annealing temperature, the band gap was decreased. When the annealing temperature was increased at same spin speed, the band gap was decreased. Piezoelectric test had proven the ZnO film could produce electricity. The maximum voltage (20.7 mV) was produced by the ZnO film with spin speed of 2000 rpm and annealing temperature of 300 °C.

DESIGN AND CHARACTERIZATION OF SPIN COATER TO SUPPORT NATIONAL SEMICONDUCTOR INDUSTRY

<p>Recently, semiconductor industry grows rapidly due to high demand of modern electronic system. In addition, the value of investments in Indonesia electronic industries also more than doubled during 2015-2017. This increase in investment will certainly have an impact on the increasing the needs for electronic / semiconductor component processing machines. To support it, well performed spin coater then were designed. The characterization of spin coating process was done at BSN (formerly was known as Research Center for Metrology LIPI) using roughness measuring instrument/ profilometer that traceable to PTB (Germany) to guarantee the validity of the measurement results. Characterization experiment used positive photoresist SPR3018 to see the performance of system designed. Three different experiments were performed to determine the impact of spin speed and spin time to photoresist thickness and uniformity. The characterization shown that on spin speed increased, the photoresist was deployed thinner. The thickness of the photoresist is inversely proportional to the square root of spin speed. Furthermore, the longer spin coating time, it increases the tendency of concave surface. This work is expected to benefit the practitioners of electronic systems, semiconductor industries, and even SNI conceptors.</p>

Static Stiffness Measurements for a Thrust Collar Used in an Integrally Geared Compressor

This paper presents a comparison of predicted and measured axial stiffness of an oil-lubricated thrust collar (TC) for use in an integrally geared compressor (IGC). The test rig used to measure the stiffness closely resembles a TC that would be used in a production IGC. Separate motors spin two shafts at predetermined spin speeds, and a pneumatic loader applies an axial load to the pinion shaft. The load is transmitted from the pinion shaft through the TC and onto the bull gear shaft. The relative deflection between the faces of the TC is measured as the axial load is increased. Tests were conducted at pinion spin speeds of 5, 7.5, and 10 krpm, and the axial load was varied from 75 to 2,600 N (1 to 32 bar specific load). A custom curve fit describes the load-deflection plot. The slope of the equation is the stiffness coefficient, kz. The measured kz values increase versus axial load, and decrease versus spin speed. Measured and predicted values agree in trend and magnitude. Predicted kz values slightly overestimate the measured results. The power loss from the lubricated area is measured from VFD power outputs. Power loss increases with spin speed and the measured power loss tends to be twice as high as predictions. These results are useful in validating the predictions made by Cable et. al.[1] The results are also useful to IGC original equipment manufacturers (OEMs) or end-users who desire to model their machines.

Experimental determination of the aerodynamic coefficients of spinning bodies

ABSTRACTTo accurately predict the probabilities of impact damage to aircraft from runway debris, it is important to understand and quantify the aerodynamic forces that contribute to runway debris lofting. These lift and drag forces were therefore measured in experiments with various bodies spun over a range of angular velocities and Reynolds numbers. For a smooth sphere, the Magnus effect was observed for ratios of spin speed to flow speed between 0.3 and 0.4, but a negative Magnus force was observed at high Reynolds numbers as a transitional boundary layer region was approached. Similar relationships between lift and spin rate were found for both cube- and cylinder-shaped test objects, particularly with a ratio of spin speed to flow speed above 0.3, which suggested comparable separation patterns between rapidly spinning cubes and cylinders. A tumbling smooth ellipsoid had aerodynamic characteristics similar to that of a smooth sphere at a high spin rate. Surface roughness in the form of attached sandpaper increased the average lift on the cylinder by 24%, and approximately doubled the lift acting on the ellipsoid in both rolling and tumbling configurations.