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In this work, we evaluated the different energy consumption rates associated with the total frictional energy for a ball sliding on a flat surface. The energy generated by the sliding two bodies in contact is dissipated into the materials in various forms. The wear consumption energy for a steel ball against a diamond-like carbon surface was evaluated by the wear coefficient of the wear volume–energy input equation. The strain energy generated in the steel ball as a result of being made to slide under a certain load was calculated using the Hertzian theory. The chemical reaction energy was estimated based on iron oxidation. Finally, the frictional energy dissipated as heat was obtained by subtracting the wear and the strain energies from the total frictional energy.

Supplemental digital content is available in the text., BACKGROUND Fibrinogen plays a key role in hemostasis and is the first coagulation factor to reach critical levels in bleeding patients. Current European guidelines on the management of traumatic or perioperative bleeding recommend fibrinogen supplementation at specific threshold levels. Whole blood viscoelastic tests provide fast evaluation of fibrin deficits. Fast measurement of plasma fibrinogen concentration is not yet available. We investigated a method to rapidly determine whole blood fibrinogen concentration using standard Clauss assays and a steel ball coagulometer and provide an estimate of the “plasma-equivalent” fibrinogen concentration within minutes by adjustment of the measured whole blood fibrinogen concentration with a quickly measureable hemoglobin-derived hematocrit. METHODS The feasibility of this approach was tested with a Clauss assay using multiple porcine fresh blood samples obtained during in vivo bleeding, hemodilution, and after treatment with hemostatic therapy. Two different Clauss assays were then tested using multiple human volunteers’ blood samples diluted in vitro and supplemented with fibrinogen concentrate. Comparative measurements with fibrin-based thromboelastometry tests were performed. RESULTS Regression and Bland-Altman analyses of derived “plasma-equivalent” fibrinogen and measured plasma fibrinogen concentration was excellent in porcine and human blood samples, especially in the ranges relevant to traumatic or perioperative bleeding. CONCLUSION Fast whole blood fibrinogen measurements could be considered as an alternative to plasma fibrinogen measurement for acute bleeding management in trauma and perioperative care settings. Further studies are needed to prove this concept and determine the turnaround times for its clinical application in emergency departments and operating theaters.

Mesoporous silica nanospheres (MSNs), with neat morphology, large Brunauer–Emmett–Teller (BET) surface area and uniform pore diameter, have been synthesized firstly, and then the liquid paraffin as lubricating oil is poured into the pores of the MSNs via a simple wet impregnation method to form paraffin-containing MSNs (abbreviated as PMSNs). The tribological tests are carried out under three different loads (1.0, 1.5, and 2.0 N) by sliding a steel ball (φ = 6 mm) against PMSNs thin films spin-coated on glass slides. The results indicate that the friction coefficient of glass slide reduces greatly from 0.7 to 0.09 due to the effective release of liquid paraffin preserved inside the pores of MSNs under these loads. Meantime, the corresponding wear volumes of glass slides also decrease greatly after the formation of the PMSNs film. As a result, the present work lights a pharos to utilize lubricating oil more effectively via releasing oil preserved inside the pores of the MSNs.

Summary Casting is one of the commonly used techniques in industries for the manufacturing of metal products. Although sand is used as a mould material for casting, its permeability and thermal conductivity are very low and hence affects the microstructure and mechanical properties of the cast product. Therefore using alternate material for the mould may result in better permeability, heat transfer rate and thereby better properties. In the present work, steel balls are used as mould material and the effect of grain size on the permeability of the mould material is studied. Steel balls of different diameters namely 0.18 mm, 0.6 mm and 1 mm which are commercially available were used. From the experiments conducted, it is confirmed that coarser steel balls showed more permeability and thereby can help in easy escape of hot gases (from the molten metal and mould material) during pouring of molten metal into the mould.

Sensors described in this paper are able to transform parameters like acceleration or tilt, but even so magnetic field strength into electrical signals. They offer a unique PUF (Physical Unclonable Function) characteristic and allow definitely no duplication. The heart of each of these sensors is a variable capacitance. The whole sensor, built on a Printed Circuit Board (PCB), has an InterDigitated Electrode (IDE) structure and a flexible polydimethylsiloxane (PDMS)-membrane filled with conductive steel balls. The distance between the membrane and the board is about 500 μm. External mechanical or magnetically forces can excite the membrane to move. Due to that, the capacitance changes, delivering certain Voltage signals. Since steel balls are randomly distributed, each sensor shows a unique behavior. Possible offset problems solves a differential capacitance arrangement. Therefore, a second IDE-structure is located above the membrane with a distance of about 500 μm. Output-Voltages of this double side capacity arrangement show only the position of the membrane in relation to both IDE's. Sensors having this structure and different steel ball distributions are simulated using the finite element analysis software 'COMSOL'-Multiphysics. Each sensor shows a different output signal at equal excitations. Moreover, experimental investigations show different measured values for different sensors for similar external excitation forces. This unique reaction on changes of excitation is a dynamic behavior, which stands out clearly against known and most static PUF-solutions. It makes the sensors attractive as hardware elements for security solutions. Identity cards, pay-cards or credit cards equipped with one of these sensors will become an unclonable uniqueness. Compared with other security systems, this PUF-sensor shows a great simplicity in design and data collection, a dynamic data acquisition, which completely prevents unauthorized use and it does not require no electrical energy sources.

Detection of bruises on apples is important but difficult for an automatic apple sorting system. The objective of this study was to develop a prototype multispectral imaging system for online detection of bruises on apples. A hyperspectral imaging system with the wavelength range of 325–1100 nm was built to select the effective wavelengths for detecting bruises on ‘Fuji’ apples. Segmented principal component analysis (PCA) was conducted on the 450–1000 nm, 450–780 nm and 780–1000 nm hyperspectral images respectively and the resultant principal component (PC) images were compared. Three effective wavelengths 780, 850 and 960 nm were determined by the weighing coefficients of the best PC images. The performance of the selected effective wavelengths was evaluated by 183 apples. The detection accuracies of apples with bruises created by dropping a steel ball from a 500 mm height in 1, 12 and 24 h were 90.4%, 92.3% and 92.3%, respectively. The detection accuracies of apples with bruises created by dropping a steel ball from 200, 300, 400 and 500 mm heights in an hour were 92.4%, 96.2%, 96.2% and 94.7%, respectively. Then a multispectral imaging system with two dichroic beamsplitters, two band-pass filters and three prism-based 2CCD multispectral progressive area scan cameras was developed. The online image acquisition speed was about 3 apples per second. The performance of the developed system was evaluated by static and online tests using 59 independent apples. The classification accuracies of bruised apples in static and online tests were 91.5% and 74.6%, respectively. Results showed that the developed multispectral imaging system based on the selected effective wavelengths using a hyperspectral imaging system and segmented PCA could be used for online detection of bruises on apples.

The friction and wear properties of nitrile rubber (NBR) against 316L stainless steel pairs were investigated by using a sphere-on-disc test device. The influence of Al2O3 particle sizes and the normal load on the tribological behaviors of the pairs were primarily evaluated. The damage behaviors of worn surfaces were analyzed using a scanning electric microscopy (SEM) and a surface profilometer. The results show that the friction coefficient decreased because of particles coming into contact pairs, while particles also play an important role in increasing the wear loss of stainless steel with many furrows on the steel ball surface due to the ploughing effect of hard particles. Large-sized particles could accelerate the wear of rubber, and the micro-cutting scratches of the stainless steel induced by the Al2O3 particles embedded in the rubber matrix. However, as the particle’s size decreased, the wear loss of the rubber was gradually mitigated. It is obvious that the normal load affected the wear of the rubber to a larger extent than the stainless steel. Moreover, with large particles, the wear loss of rubber increased sharply with increasing the normal load. In addition, the NBR/stainless steel tribo-pairs presented different wear mechanisms, under different conditions, such as having no particles or varied particle sizes.

In the iron making industry, the blast furnace is charged with coke and ore (metallic) particles by means of an inclined chute rotating about its vertical axis. For each rotation, the particles fall on the sloping burden and form a circular ring. Charging of this metallic ore burden over the layer of coke causes a portion of the coke layer to get dislodged from its original position. This phenomenon is known as coke collapse. We have studied these phenomena in a quasi two dimensional rectangular bin on a smaller scale. In-order to get the desired density difference between the pouring media, stainless-steel balls (representing the ore) and glass- beads (representing the coke) are used as the model granular materials. The parameters varied in the experiments are the volume of pouring and the size of particles (steel balls). Varying quantities of these particles are poured into the experimental unit and the resulting pattern thus formed is then captured using a Nikon-DX camera. The images are analyzed using computer code to determine the position of each particle (steel ball and glass bead). The results presented here are in terms of concentration of steel balls by making bins of 5x5 mm in size. The interface (stock line) between the steel balls and the glass beads has been analyzed separately and plotted for all data sets. Each experiment has been repeated three times in-order to get an average data.

The results of numerical and experimental studies of the effective thermal conductivity of dis� persed materials with contrast inclusions are presented. The numerical analysis was based on using the mul� tiscale finite element method making it possible to calculate heat transport in media with ordered and chaotic location of the inclusions. The influence of the concentration of inclusions and the manner of their packing on the value of the effective coefficient of thermal conductivity was analyzed. The coefficient of thermal con� ductivity was studied experimentally for two media, gypsum and plexiglass with inclusions of steel balls (d = 3 mm) with different packing. The comparison of the results of measurements and numerical simulation makes it possible to verify the elaborated program complex and determine the boundaries of application of the available analytical dependences.

In this paper, we consider a control problem of a ball and beam system in a situation where feedback is disconnected. Due to feedback disconnection, any feedback controller is not available and as a result, the position of the steel ball cannot be hold for long. The main difficulty is the open-loop environment at the happening of feedback disconnection. We show that bang-bang control input can be a good candidate which holds the ball position with certain bounds for the longest time.

The behavior of pools of water for lubrication under a point of contact between a glass disk and a steel ball is studied here, employing a home-built apparatus. A deformed water pool is found to form around the contact region under different rolling speeds. To investigate the effect of rolling speed on the water pool, two parameters (advancing angle and receding angle) are introduced to describe the shape of the water pool. Two distinct glass surfaces, namely a smooth surface and a microgrooved surface, are observed. In the case of the smooth surface, the advancing/receding angle of the water pool significantly decreases with increasing rolling speed before the rolling speed reaches a critical value (80 mm/s). At speeds higher than 80 mm/s, the water pool is in a stable state and the advancing/receding angle remains steady. In the case of the microgrooved surface, the influence of the microgroove on water lubricating flow disappears when the rolling speed reaches a critical value (1030 mm/s).

The measurement of large forces and the presence of errors due to dimensional coupling are significant challenges for multi-dimensional force sensors. To address these challenges, this paper proposes an over-constrained six-dimensional force sensor based on a parallel mechanism of steel ball structures as a measurement module. The steel ball structure can be subject to rolling friction instead of sliding friction, thus reducing the influence of friction. However, because the structure can only withstand unidirectional pressure, the application of steel balls in a six-dimensional force sensor is difficult. Accordingly, a new design of the sensor measurement structure was designed in this study. The static equilibrium and displacement compatibility equations of the sensor prototype’s over-constrained structure were established to obtain the transformation function, from which the forces in the measurement branches of the proposed sensor were then analytically derived. The sensor’s measurement characteristics were then analysed through numerical examples. Finally, these measurement characteristics were confirmed through calibration and application experiments. The measurement accuracy of the proposed sensor was determined to be 1.28%, with a maximum coupling error of 1.98%, indicating that the proposed sensor successfully overcomes the issues related to steel ball structures and provides sufficient accuracy.

Herein, we develop a supersensitive pressure sensor based on a fully air-bubbled ultralight graphene block through a simple sparkling strategy. The obtained sparkling graphene block (SGB) exhibits excellent elasticity even at 95% compressive strain and rebounds a steel ball with an ultrafast recovery speed (∼1085 mm s–1). Particularly, the SGB-based sensor reveals a record pressure sensitivity of 229.8 kPa–1, much higher than other graphene materials, because of the highly cavity-branched internal structure. Impressively, the pressure sensor can detect the extremely gentle pressures even beyond the real human skin and hence are promising for ultrasensitive sensing applications.

The interface characteristics of liquid films confined within a nanogap between a steel ball and a smooth glass disk after exposing to an external electric field (EEF) are reported in the paper. The emergence of micro-bubbles induced by the EEF has been found to be closely related with the electric current flow at both a positive EEF and a negative EEF. The polarity effect of the variation in the electric current flowing through a polar liquid film over time is more pronounced than that through a nonpolar liquid film. The surface of the contacting pair with the polar liquid film confined after the removal of the EEF is more severely damaged at a negative EEF, while no indication of damage has been observed on the surface contacting the nonpolar liquid film at either polarity. The bubbles generated under a positive EEF can collapse more readily than those generated under a negative EEF. Different mechanisms of these experimental phenomena have been discussed in the paper. Copyright © 2014 John Wiley & Sons, Ltd.

Breaker stage fruit (cvs 901 and Bobcat) were subjected to different types of physical damage: 3 impacts of a steel ball (67 g) from a height of 33, 66 or 99 cm, 8 impacts of the ball from 99 cm, or dropping the fruit once 1 m onto a hard surface. Fruit were then held at 20 � C until full red, sanitized, sliced and stored at 5 � C. Damaged fruit were less firm than undamaged fruit when ripe. Slice quality (appearance, translucency, lycopene content, juice loss) and shelf-life were affected by damage to the fruit. Lycopene concentrations were higher in undamaged (4.0 mg/kg) than damaged fruit (3.5 and 2.7 mg/kg with 3 impacts from 99 cm and drop damage) and decreased during storage at 5 � C. Translucency increased with time and onset was more rapid in moderate to high damage fruit. Juice loss was higher in slices from undamaged (6e8 g/100 g FW) than damaged fruit (1e4 g/100 g). Severe damage resulted in collapse of locular tissue and moderate damage may have induced mealiness. PG activities differed little between slices from severely damaged and undamaged fruit and no differences in PME activities were found.

This paper presents the results of the profilometric analysis of wear tracks from tribological tests of a composite material made by Diamond Metallplastic GmbH, Germany. This material has a polymer matrix reinforced with Cu, Zn, Sn particles, and various allotropic forms of SiO2. The material belongs to Multimetall Messing category and is recommended by the manufacturer for repairing brass made parts. This composite material was tribologically tested in dry friction reciprocating conditions, in ball-on-flat configuration, using the tribotester CETR-UMT-2 (Bruker Corporation). The counterpiece was a steel ball. The tests were conducted at normal loads of 20, 30, 40 and 50N, over a distance of 100 m, at an average sliding speed of 3,50 mm/s, at room temperature and relative humidity of 40-60%. The wear tracks were examined with the help of a laser profilometer and the profilometric module of the tribotester CETR-UMT-2 (Bruker Corporation). The profilometric analysis results for the composite are compared to those obtained for brass. Comparing the wear tracks of the two materials, it can be found that the composite material has a better tribological behavior than the brass.

The design of the optical fiber sensor system is used to detect the steel ball surface roughness and defects with displacement change such as cracks, pits, bumps and so on. Experiment results show that the sensor can distinguish between surfaces with different roughness. By establishment of the equivalent evaluation standard for surface quality, the system could detect whether the steel ball surface quality is qualified.

Precision steel ball is one of the most critical components for rolling transmission. As precision ball affects the performance of precision transmission system, fully inspection of these balls is an urgent need for the industry. This paper is to develop a real-time inspection system for surface defects of precision steel ball with fast and robust method and mechanism. The developed system consists of an optical measurement module as well as a mechanism module for full surface inspecting of the steel ball. The minimum defect and area can be detected by the developed system are 0.1mm and 0.01 mm2 respectively. The developed system has been testified against the designed specifications at speed higher than 3pc/sec and less than 0.5% missing rate. It verified the resolution, accuracy and robustness of the developed system which is capable for final defect inspection of steel balls for grade 100 bearing.

LCD panels are used widely in all sorts of devices. Since glass is the main material used to make the panels, scratch resistance is an important issue in acquiring high quality LCD panels. In this work the wear behaviors of three types of commercially available LCD panel glasses were investigated. A pin-on-reciprocating tribotester was used to perform the wear tests using the glass specimens against a stainless steel ball. The hardness of the specimens was initially obtained. It was shown that the wear amount varied with respect to the applied load as well as the type of glass. The wear pattern of the glass specimen was also characterized using confocal microscopy. It is expected that the results of this work will aid in improving the tribological properties of LCD panel glass.

Based on macro morphology, metallographic microstructure, field emission scanning electron microscope observations and microhardness testing, failure analysis of the GCr15 steel balls in the ball screw pair was dealt with in this paper. The experimental results showed that small scratches and pits were evenly distributed on the surface of the A steel ball which showed features of wear failure. Characteristics of the B steel ball surface morphology were contacted to fatigue failure. Microstructure observation on the cross-section of the B steel ball showed that martensite and carbides were uneven distributed which were caused by the uneven elements distribution in the raw materials. It was the main cause of this abnormal failure. Therefore, the quality of the raw materials needed to be strictly controlled and the reasonable heat treatment process should be adopted to ensure the quality of the steel balls.

This paper presents stress analysis for globoidal indexing cam mechanism with steel ball, and stress model of each component is established. Globoidal indexing cam mechanism with steel ball is made up of globoidal cam, indexing plate and steel ball. The mechanism can realize approximate rolling transmission. Stress is analyzed for globoidal cam, indexing plate and steel ball at dell and indexing period respectively. According to rotary transform tensor theory stress in different coordinate system is obtained to build static equilibrium equations for steel ball conveniently. Axial force, radial force and peripheral force for globoidal cam and indexing plate are reached.

The fundamental principle of three dimensional Element-free Galerkin has been briefly investigated in this paper, and built forming mode of steel ball cold forging, Element-free Galerkin method successfully applied to the simulation analysis of steel ball cold forging forming process in the LS-DYNA simulation software. In comparison to Finite Element Method and experiment data, Proved Element-free Galerkin method was feasible in metal plastic forming process, and in the large deformation simulation was more accurate than the finite element method, Element-free Galerkin method has more obvious advantages after altering the impact factors.

Toughness index is an important parameter of the quality of super-abrasive grits. In order to improve the design of the toughness index tester more reasonably and efficiently, we calculated the velocity of a steel ball in the capsule and simulated the impact process between the steel ball and the different capsule end faces with the ANSYS/LS-DYNA. The main results are as follows: (I) the maximum velocity of the ball is approximately 2.0106m/s. (II) with the increase of the curvature, the maximum value of normal stress declines while the effective area rises. (III) the maximum shear stress cannot cause diamond grits to break directly, but it can make small cracks and defects of the impacted grits propagate. These assertions are validated by the simulation which explains the experimental phenomenon well.

The tribological behavior of a Ni3Al alloy prepared by hot-pressed sintering was investigated at dry friction and sea water condition against AISI 52100 steel ball in ambient environment and at varying loads. The tribological results suggested that the Ni3Al alloy has the better wear resistance properties compared to Ti–6Al–4V alloy at dry friction and sea water conditions, and the Ni3Al alloy possesses the excellent wear resistance properties under sea water environment. Sea water plays a significant role in the improvement of tribological properties of the Ni3Al alloy, which has lubricating, cooling, and corrosive effects on the friction pairs.

The effects of normal load, sliding speed, and surface roughness on the friction and wear of high-purity niobium (Nb) during sliding without and with an introduction of water were systematically investigated. Increasing the normal load or sliding speed decreased the friction of the Nb under the both dry and wet conditions because the increased wear of the Nb decreased the interfacial shear strength between the steel ball and Nb by promoting the surface roughening and the production of wear debris. However, the Nb tested at the lowest sliding speed under the lowest normal load with water exhibited the lowest friction and wear due to the formation of oxide layer on the wear track. The friction and wear of the Nb tested under the dry condition decreased with increased surface roughness because the higher interfacial shear strength between the steel ball and smoother Nb resulted in the earlier breakdown of the native oxide layer and direct contact between the steel ball and Nb. However, increasing the surface...

This paper reports performance results for steel bridge railings installed on concave- and convex-curved bridge parapet based on new-type posts. Preliminary experimental tests are first conducted to examine the behaviours of these posts when subjected to a collision from a heavy steel ball. The values thus verified are then fed into the LS-DYNA 3D analysis tool to generate improved simulations for the performances of new-type curved steel railings subjected to truck collisions. For some concave road curvatures, it is found that the impact angles between the vehicle and the railings are larger than assumed in the current Japanese specifications. Some researchers and engineers suspect that a curved railing is less effective than a straight one in the same collision conditions. The purposes of this study, in addition to contributing to the further improvement of curved steel railings, are accordingly to test the validity of the said suspicion, and to investigate the performances of these new-type concave-curved steel railings under larger collision impact angles. The performance results for concave- and convex-curved railings are compared against each other as well as with the results for straight railings.

Grinding fitness caused by the failure of the steel ball filling rate, inappropriate steel ball matching, large steel ball size, etc. cannot meet follow-up flotation requirements. In order to optimize the ball grinding process, enhance the single separation degree of minerals and separation index, the steel ball diameter, steel ball matching and required additional balls of the mill are calculated with theoretical of ball radius formula and accurate filling ball method.

Short carbon fiber (SCF) reinforced epoxy composites with different SCF contents were developed to investigate their tribological properties. The friction coefficient and wear of the epoxy composites slid in a circular path against a steel pin inclined at 45° to a vertical axis and a steel ball significantly decreased with increased SCF content due to the solid lubricating effect of SCFs along with the improved mechanical strength of the composites. The scanning electron microscope (SEM) observation showed that the epoxy composites had less sensitive to surface fatigue caused by the repeated sliding of the counterparts than the epoxy. The tribological results clearly showed that the incorporation of SCFs was an effective way to improve the tribological properties of the epoxy composites.

An experiment is used to research the influence of injection stress towards the wear of steel ball in reinforced grinding processing under the setting condition. The field-emission electron microscope is used to obverse the samples surface morphology and the phonology equipment of surface morphology is used to measure the surface morphology of samples. The surface of the steel ball wear degree is analyzed by the surface morphology indirectly. Experimental research shows that in the condition of setting experiment, the injection pressure of reinforced grinding should not lager than 0.6MPa. If not, the obvious wear will appear in the surface of steel ball and the disadvantageous influence will happen, such as scratching the surface of workpiece under processing.

Comprehensive treatment,we should have a test on the 300 MV unit steel ball coal mill pulverizing system.At the same time,analyze the main operating parameters before modification.Transform the pulverizing system and optimize the run mode of the pulverizing system by comprehensive treatment.So we can control the pulverizing unit consumption under 30KWh/t.It makes the pulverizing system in the best state.Then we can ensure its economic and safe operation.

Wear is the main failure form of unfolding wheel for bearing steel ball. When the wear increase to a certain extent, the function of the wheel is ineffective. According to the unfolding wheel structure and unfolding principle, the critical failure condition of the unfolding wheel is established. Based on the classical Archard wear model and combined with the finite element method, a discrete Archard wear model is proposed, and a prediction model of the wear life of the unfolding wheel is established. Using Ansys software to simulate the wear of the unfolding wheel, the relationship equation between the wear depth and the wear times is obtained, and the wear life prediction of the unfolding wheel is carried out.

Sweet cherry fruit is considered very sensitive to physical injury produced during harvest and postharvest handling. Surface depression (pitting and bruising) appears on the injured fruit area after a week of storage at 0°C. Two trials were conducted on ‘Van’, ‘Royal Dawn’, or ‘Sweetheart’ sweet cherry to test the hypothesis that fruit becomes more sensitive to physical injury at lower temperatures. In the laboratory trial, the incidence of impact damage was evaluated by dropping a steel ball at ten cm height on fruits with 2, 7, 10 or 15°C pulp temperature. A significant reduction in pitting incidence was obtained when the fruit temperature was increased from 2°C to 7°C or 10°C for ‘Van’ and ‘Royal Dawn’. In the packing line trial, ‘Sweetheart’ fruit were placed on a commercial packing line using cold water to achieve a 2.5-3.8°C or 5.3-6.3°C fruit temperature. The incidence of pitting and bruising from fruit handling at 5.3-6.3°C was 30.9% compared with 70.8% when the fruit temperature was in the range of 2.5-3.8°C. Evaluations comparing the different sectors of the packing line demonstrated that fruit at low temperature was more sensitive to develop small pit symptoms and these were mainly induced at the stem cutting sector. Therefore, water temperature management along the cherry processing line is required to reduce surface pitting symptoms after storage.

The evolution of transfer layers derived from a-C:H coating/steel ball tribopairs sliding in ambient air is tracked by performing one set of overlapping tribotests on a ball-on-plate device with acceptable repeatability of friction coefficients. After sliding tests, counterparts were separated and probed by optical microscopy, SEM/EDX and XPS. Carbon-based transfer layers were built up in the first cycle of sliding. Except for the typical graphitization of transferred carbon materials, a chemisorbed layer rich in C/O groups was also found on the top surface of transfer layers, and considerably affected the friction behavior of a-C:H coating/steel tribopairs in ambient air.

Three-dimensional electrode method is especially suitable for the treatment of low concentration wastewater containing Cu2+. Study the changes on the Cu2+ removal rate, under the condition of different electrode filling material (such as steel ball, activated carbon, activated carbon and resin). The results show steel ball as filling-material is best. Steel ball has higher removal efficiency of Cu2+, up to more than 80%. Steel ball as filling-material the effect of electrode distance on Cu2+ removal is smallest. Compared with steel ball as filling-material, the response time of activated charcoal is no obvious disadvantage.

This article introduced an accurate to ascertain the size of fine grinding medium. Comparative grinding tests are done by using cast iron segment steel ball. Grinding test results showed that mill capacity and grinding efficiency of cast iron segment could be really superior to steel ball. Grinding and flotation indexes have gotten obvious improvement when applying optimized fine grinding medium for industrial experiment.

In view of serious degree of mouth formation rock weathering, poor stability, the construction excavation characteristics such as easy to collapse of underground engineering, incision reinforcement technology is used in underground engineering in the mouth period of construction, which changes the mechanical properties of surrounding rock and improves the penetration resistance of surrounding rock. Using three dimensional finite element program (ls-dyna) numerical simulations show that the stratified structure of the grouting tube in the surrounding rock is similar with covering layer thickness steel ball, which makes the projectile yaw in the process of penetration movement. As is shown through comprehensive calculation and analysis, the zero incision reinforcement technology can make the penetration resistance of the underground engineering mouth period increased by 30% ~ 40%.

The tribological behaviour of stainless steel (SUS 440C) relative to that of diamond-like carbon (DLC) was investigated in terms of tribometer input energy. The DLC was prepared on tungsten carbide (WC) substrates using radio frequency plasma chemical vapour deposition with benzene (C6H6) as a gas source. The stainless steel ball, as the counterpart, was tribotested. The input energy was calculated using the applied load, friction coefficient and sliding distance obtained from each tribotest. The wear loss of the ball increased as the sliding distance increased, whereas wear loss of the DLC was not directly observed. During evaluation of the input energy, the wear rate of the stainless steel ball decreased as the input energy increased. We propose a method for evaluating tribological properties using the input energy and discuss the wear behaviour of the stainless steel based on the input energy.

To study the effects and optimal operating parameters of three-dimensional electrode electrolysis process for PCB wastewater containing Cu2+, the effects of electrolytic voltage, plate distance, material of plate, filling element and electrolyte were inspected to decide optimal experiment conditions. The experimental result showed that the optimal conditions were 3.0cm plate distance, steel ball as the filling material, 10V electrolytic voltage, and 45 min electrolytic time, and the removal rate of Cu2+ wastewater reaches 82.3%. The electricity costs were 1.11 yuan/m3.

Wear properties of CrN/NbN superlattice coating deposited on the WC-12Co substrate was investigated while using 100Cr6 steel, SiC and Al 2 O 3 ball as counterbodies for friction pairs. The value of friction coefficient and wear rate was lowest at ~ 0.01 and 2.6 × 10 − 7 mm 3 /Nm, respectively, when coating slides against Al 2 O 3 ball. In contrast, friction coefficient and wear rate were increased while sliding with steel and SiC ball. The deviation in friction coefficient was described by mechanical and chemical properties of these balls. Hardness of Al 2 O 3 and SiC ball was comparable but significant deviation in friction coefficient was observed. That is related to oxidation resistance of these balls which is high for Al 2 O 3 compared to SiC ball as evident by Raman analysis of the wear track. However, hardness and oxidation resistance were low for steel ball which shows oxidational wear mechanism.

Formulae are derived from first principles which predict the wear depth of a ball and a flat surface through time as they slide against each other, in relation to any phenomenological law for wear volume, and taking into account the effect of component geometry. The equations can be fit using experimental wear volume data from ball-on-flat tribometers. The formulae remove previous limiting approximations made in the literature and extend to the prediction of the wear depth of both contacting surfaces. The wear model accords with a previous model that is validated by pin-on-disc testing of a steel/steel contact. The current paper uses the formulae derived to predict the wear depth of a diamond-like carbon (DLC) coating and a steel ball as they slide against each other in deionised water. An Archard equation is used to predict the wear volume of each surface; however, a DLC coating is known to form a transfer layer which reduces the rate of wear, and since this scenario does not obey Archard’s law directly, a time-dependent-specific wear rate is used to fit a semi-empirical model to experimental results. The final model predicts the wear depth of the ball and flat accurately.

Samples of concrete contain various waste materials, such as iron particulates, steel balls of used ball bearings and slags from steel industry were assessed for their anti-radiation attenuation coefficient properties. The attenuation measurements were performed using gamma spectrometer of NaI (Tl) detector. The utilized radiation sources comprised 137Cs and 60Co radioactive elements with photon energies of 0.662 MeV for 137Cs and two energy levels of 1.17 and 1.33 MeV for the 60Co. Likewise the mean free paths for the tested samples were obtained. The aim of this work is to investigate the effect of the waste loading rates and the particulate dispersive manner within the concrete matrix on the attenuation coefficients. The maximum linear attenuation coefficient (μ) was attained for concrete incorporates iron filling wastes of 30 wt %. They were of 1.12 ± 1.31×10−3 for 137Cs and 0.92 ± 1.57 × 10−3 for 60Co. Substantial improvement in attenuation performance by 20%–25% was achieved for concrete samples incorporate iron fillings as opposed to that of steel ball samples at different (5%–30%) loading rates. The steel balls and the steel slags gave much inferior values. The microstructure, concrete-metal composite density, the homogeneity and particulate dispersion were examined and evaluated using different metallographic, microscopic and measurement facilities.

In this work, a new method to determine the interference grade of the central film is put forward. The interference figure is generated on a steel ball and a glass disc with a green monochromatic two-beam interferometry. With gradually increasing the rotational speed of the glass disc, the corresponding interference intensities of the central contact area are continually collected and sent to the computer. With these data, the periodical curve of the central interference grey value with the sliding speed has been drawn. Then, the curve is compared with the theoretical result so that the central interference grade of each figure can be determined. It has been found that while the sliding speed varies from 0.09 m/s to 0.21 m/s, the central interference grade of the interference figure is the first under the working conditions of the present paper. As the sliding speed increases between 0.21 m/s and 0.4 m/s, the second grade of the central interference figure is achieved. As the central interference grade has been known, the film thickness and the film shape can be easily determined by the interference picture of the EHL film and the relative optical intensity principle.

the automobile constant velocity universal joint driving shaft is the important component in modern cars, its design is mainly to check the movement compatibility of parts. The constant velocity universal joints driving shaft is designed by three-dimensional solid modeling software UG, and the motion simulation model is build by multi-body dynamics simulation software to investigate the constant speed performance of constant velocity universal joints driving shaft, and check the motion trace of steel ball which is the key component of constant velocity universal joints. The results show that the constant speed performance is good, and the track design of star-like inner race is reasonable.

In order to solve the forming defects in the steel ball cold heading process, a novel force sensor which chooses the PVDF piezoelectric films as force-sensing elements is designed. The advantages and disadvantages of piezoelectric force sensor on measurement of the cold heading force are compared with existing force sensors. By using FEM, sensor’s linearity and the structure size are analyzed. Compared with the traditional sensor, this structure is more reasonable. The presented PVDF piezoelectric force sensor has wide frequency range, good dynamic performance, and can realize dynamic measurement.

This article focuses on analyzing the correlation between the degree of starvation and friction under the sliding motion in a ball–disk machine. The objective of this study was to define approximately the degree of starvation in the contact based on measuring one parameter (the relative coefficient of friction). Such an approximate approach could be useful in cases of opaque contacts where the optical interferometry technique cannot be used; for example, a steel ball on a metal disk. Experimental measurements were conducted under different degrees of starvation using a tribometer equipped with a torque sensor and a high-speed digital camera. The results showed agreement between the theoretical equations and the experimental measurements. Thus, it can be stated that the approximate ratio of the film thickness reduction can be predicted based on accurate measurements of friction.

The purpose of this study is to present a kind of novel cycloid steel ball planetary transmission with one- tooth difference and to examine the feasibility of this mechanism using PRO/E-based kinetic simulation. The mechanism's structure and transmission principle are introduced and the geometry of tooth surface for the planet gear is described and analyzed; and further, the rule of determining the directrix of tooth surface is deduced to avoid the interference and self-cross of tooth surface. On PRO/E software platform, the main parts of this mechanism are virtually modeled and assembled and the kinetic simulations on the movement trajectory and the velocity relationship are performed. The obtained results confirm that the cycloid steel ball planetary transmission with one- tooth difference is feasible.