Disk Device Research Articles

Effect of nano-additives on friction and wear characteristics of blended lubricants containing "palm oil and Al-Rashid engine oil SAE 15W_40"

The research aims to evaluate the nano-additives for oil, decreasing friction, surface roughness, and decreasing wear.Wear and friction coefficient are examined using a pin on a disk device; adding 2 wt.% nano-additives to the blended lubricant resulted in maximum friction and wear.In the current research, one of the more significant findings to emerge from this study is that the nano-additives increase viscosity and reduce wear and friction coefficient. The highest viscosity values were when adding GNP, and improving the percentage of nano-additives leads to an increase in viscosity.The results reveal that the additive was chosen as the most appropriate concentration in the blended lubricant.An experimental investigation was conducted to explore the effects of nano-additive graphene nano-powder (GNPs), molybdenum disulfide (MoS2), and titanium oxides (Tio2) in concentrations (0.5%,1%, 1.5%, 2%,2.5% ) as additives to engine oil (Al-Rashid oil) SAE 15W_40 and 5% palm oil.The results presented in the given paper may facilitate improvements in the nano-additives, resulting in increased viscosity compared to the base oil.

Facet joint loading after 1-, 2- and 3-level cervical disc arthroplasty: a comparison of spiked versus keeled baseplates

BackgroundThe purpose of this study was to examine facet contact forces above, below, and at surgical index levels induced by artificial disc implantation and compare the results from spiked versus keeled baseplates comprising the arthroplasty device. MethodsHuman specimens from C2 to C7 were subjected to flexion, extension, and lateral bending prior to, and following random allocation to spiked or keeled cervical arthroplasty at the index (C5-C6), inferior (C6-C7), and superior (C4-C5) levels. Thin film force sensors were inserted unilaterally into the corresponding facets prior to intact testing. Force data was normalized to the minimum forces recorded during each loading mode under each condition, reported as (Max/Min) force ratio and subjected to a 1-way ANOVA with Dunnett's post-hoc tests for comparison to intact specimens. ResultsUnder flexion, compared to intact, all levels displayed a significant reduction in force ratio following a 1- and 3-level implantation for the spiked baseplate device. An increase in force ratio was observed at the index level for a 2-level implantation but was mitigated with the completion of a superior device insertion. No statistical differences were noted for keeled devices. In extension, the spiked baseplate device reduced the force ratio for 1- and 2-level implantations. A 3-level insertion did not alter facet force ratios. For the keeled device, no statistical changes were noted. Lateral bending associated with spiked devices resulted in statistically reduced or nonsignificant changes in facet loading ratios. The keeled devices did not display significant changes to facet force ratios. ConclusionsImplantation of multilevel disc devices can reduce or sustain unaltered facet loading conditions. In general, 3-level arthroplasty statistically reduced or does not increase facet force ratios compared to intact values. The use of spiked versus keel device baseplates is a clinical selection involving anterior/posterior placement and endplate degeneration conditions.

Effects of nZVI on the migration and availability of Cr(VI) in soils under simulated acid rain leaching conditions

Hexavalent chromium, Cr(VI), is a ubiquitous toxic metal that can be reduced to Cr(III) by nano-zero-valent iron (nZVI). Finding out effects of continuous rainfall leaching on the Cr(VI) release and availability remains a problem, needing to be addressed. Whether the Cr(VI) reduction by nZVI and continuous rainfall leaching lead to localized heterogeneity in soil is unclear. Therefore, two in situ high-resolution (HR) techniques of the diffusive gradients in thin-films (DGT) and planar optode were combined with ex situ sampling experiments here. Results demonstrate that nZVI decreased Cr(VI) leaching by 5.60–8.50 % compared to control soils. DGT-measured concentrations of Cr(VI), CDGT-Cr(VI), ranged from 7.31 to 19.4 μg L-1 in the control soils, increasing with depth while CDGT-Cr(VI) in nZVI-treated soils (2.41–6.18 μg L-1) decreased or remained stable with depth. However, simulated acid-rain leaching increases CDGT-Cr(VI) by 1.61-fold in nZVI-treated soils, negatively affecting the remediation. DGT measurements in bulk soils using disc devices are better at capturing the change of Cr(VI) availability at different conditions, whereas 2D-HR DGT mappings did not characterize significant mobilization of Cr(VI) at the micro-scale. These findings emphasize the importance of monitoring Cr(VI) release and availability in remediated soil under acid-rain leaching conditions for effective environment management.

Design and Performance Analysis of a Sunflower Cutting Table Based on the Principle of Manual Disk Pick-Up

To solve the problems associated with the poor harvesting ability of existing sunflower harvester cutting tables, and high seed drop rates, we designed a sunflower cutting table that can greatly improve the operational performance of sunflower combine harvesters. In this paper, we introduce the structure and principle of the whole machine and select the key parameters of the cutting table with the goal of adapting to a variety of planting modes in Xinjiang, China. Since the harvesting of sunflower in the wrong row easily causes the sunflower stalks to break, ADAMS (Version: 2020) simulation experiments were carried out to investigate the effects of the forward speed of the machine, the height of the sunflower insertion disk, and the angle of inclination of the harvest divider on the offset angle of the sunflower. With the goal of reducing the offset angle of the stalks in the forward direction of the harvest divider and reducing the size of the cutting table, the harvest divider inclination angle was chosen to be 45°; by using Design-Expert V13.0.15 software, a three-factor, three-level field test was carried out to determine the optimal parameter combinations that resulted in the minimum seed loss rate and the maximum success rate of the disk picking. Moreover, a validation test was conducted. The results show that when the forward speed is set to 0.62 m/s, the lifting speed of the pick-up disk device is set to 0.42 m/s, and the height of the inserted disk is set to 1000 mm, the relative errors between the theoretical values of the disk-picking success rate of the cutting table and the seed loss rate and the field test values are 6.5% and 1.3%, respectively. The results of the present study can provide a reference for improving the performance of sunflower harvester cutting tables and for the mechanical harvesting of inserted disk sunflowers.

Thermal insulation properties of rigid polyurethane foam modified with fly ash- a comparative study

Limitations in natural resource availability have a significant impact on prices of thermal energy. As a result, a growth of interest in the technology of insulation materials is observed. The paper presents a comparative analysis of rigid polyurethane foams, which are widely used as insulation materials. Rigid polyurethane foam with 10 wt.% addition of coal fly ash is compared to a reference foam, without any addition. The thermal conductivity coefficient of polyurethane materials was determined by the Hot Disk device. Heat transfer for both types of foams was modelled. As a result of the numerical modelling, the temperature field for the wall was obtained. The results of the computations have shown differences in energy losses. Conducted analyses demonstrate that the modified polyurethane foam (with the addition of coal fly ash) performs better as an insulation material. The reduction of heat requirement is 2.9%. An environmental analysis of the insulation materials was also carried out. Using the SUBRAW index method it was calculated that embodied energy and the carbon footprint are lower in the case of the modified polyurethane compared to the unmodified foam.

Development of designs and research of the main tribotechnical parameters of friction pairs with plasma powder friction coatings and a steel counterbody when operating in oil for friction devices

Designs are developed and studies of the main tribotechnical parameters of friction pairs with plasma powder friction coatings and a steel counterbody when operating in oil for disc and cone friction devices are carried out. The threedimensional image shows the dependence of the dynamic coefficient of friction on the sliding speeds and specific loads for the considered friction devices. Keywords: friction in oil, tribological parameters, coefficient of friction, wear, sliding speed, specific load, temperature, friction machine, new friction material, steel counterbody. au@vstu.ru

Cloud Cryptography

Cloud computing is a membership - a contract dependent on which you can get network disk space and device services. The paper also include some algorithms used in our future. This helps us to save our data from breaches and ensure security

Management of PDA device closure complicated by severe hemolysis by transcatheter retrieval and deployment of new device

BackgroundHemolysis after Patent ductus arteriosus (PDA) device closure is rare. Although in most cases, hemolysis settles on its own; however, in some cases it may not settle spontaneously and may require additional procedures like putting additional coils, gel foam or thrombin instillation, balloon occlusion, or removing it surgically. We report a case of adult PDA device closure who persisted with hemolysis and was managed by transcatheter retrieval.Case presentationA 52-year-old gentleman presented to us with a diagnosis of large PDA with operable hemodynamics. Descending thoracic aortic Angio showed a large 11 mm PDA. Transcatheter device closure was done in the same sitting with a 16 × 14 Amplatzer Ductal Occluder I(ADO) device,;however, after device release, the aortic end of the device was not fully formed and there was residual flow. The next morning patient started with gross hematuria with persistent residual flow. We tried to manage with conservative means including hydration, and blood transfusion; however, residual flow persisted for 10 days and his hemoglobin dropped from 13 gm/dl preprocedural to 7 gm/dl, creatinine increased from 0.5 mg/dl to 1.9 mg/dl, bilirubin increased to 3.5 mg/dl & urine showed hemoglobinuria. As the patient continued to deteriorate it was planned to retrieve the device by transcatheter approach. 10 French amplatzer sheath was parked in the pulmonary artery near the ductus. We tried with a combination of multiple catheters and Gooseneck snare (10 mm) and finally, we successfully retrieved with a combination of Multipurpose (MP) catheter and 10 mm Gooseneck snare. After that, we closed the defect successfully with a double disk device (muscular Ventricular septal defect 14 mm Amplatzer). The patient’s hematuria settled and was discharged after 2 days with normal hemoglobin and creatinine.ConclusionsPatent ductus arteriosus ADO 1 device should not be released if the aortic end of the disk is not fully formed Patient should be carefully monitored for hemolysis if evidence of residual shunt and given supportive treatment. If conservative treatment fails, residual flow needs to be eliminated. Transcatheter retrieval although technically challenging is a feasible treatment. A muscular VSD device is a good alternative to the usual PDA device to close PDA, especially in adults.

Influence of Nozzle Type and Wind Speed on Deposition and Interception of Pesticide Spray Drift: A Case Study with Atrazine

A wind tunnel study was conducted to compare spray drift deposition and interception profiles across ASABE (American Society of Agricultural and Biological Engineers) coarse, very coarse, and extremely coarse drop size distribution (DSD) categories as a function of wind speed. AAtrex 4L (atrazine) was used as the spray solution; disk (deposition) and rod (interception) sampling devices were deployed at multiple distances and subject to spray drift at multiple wind speeds. Drift deposition was equivalent for the coarse spray delivered at 10 mph [16.1 km/h] and the extremely coarse spray delivered at 15 mph [24.1 km/h]. Intercepted (airborne) drift was indistinguishable between the coarse spray delivered at 10 mph [6.2 km/h] and very coarse spray delivered at 15 mph [6.2 km/h], and very coarse spray delivered at 10 mph [6.2 km/h] and extremely coarse spray delivered at 15 mph [24.1 km/h]. Regulatory decisions regarding potential buffer/setback mitigations would benefit from leveraging results regarding nozzle and wind speed relationships reported in this study and others to better utilize available experimental drift data (e.g., field studies/bioassays) generated with a single nozzle but at wind speeds exceeding the label specification.

Transcatheter Closure of Atrial Septal Defect with Carag Bioresorbable Septal Occluder™: First-in-Child Experience with 12-MonthFollow-Up.

Nowadays, transcatheter device closure of an atrial septal defect (ASD) is a standard approach in children. Potential early and long-term side effects or complications related to the metal framework of the devices are a known issue. A bioresorbable device such as the Carag Bioresorbable Septal Occluder™ (CBSO) could resolve such complications. Material and Results. The Carag Bioresorbable Septal Occluder™ (CBSO; Carag AG, Baar, Switzerland) is a self-centering double disk, repositionable, and retractable device with a bioresorbable framework (polylactic-co-glycolic acid), which is almost completely resorbed by 18-24 months postimplantation. This manuscript reports the four first-in-child ASD device closures using a CBSO. The patients' age was median (IQ1-IQ3), 4.5 years (4-7.25). Weight was 21.3 kg (17.6-32.7). We demonstrated procedural feasibility and safety. Effective defect closure with the device was 100%. Echocardiographic measurements of the thickness of the interatrial septum did not show any relevant increase over a 12-monthfollow-up period. There were no residual defects found after the procedure or later during the resorption process. The patients showed no evidence of any local or systemic inflammatory reaction. The CBSO device system could offer a new treatment option for transcatheter ASD device closure in the pediatric and adult fields. In our first-in-child experience, it was effectively and safely implanted. During the first 12 months of follow-up, no complications occurred.

604 PERCUTANEOUS TRANSCATHETER CLOSURE OF SYMPTOMATIC PATENT FORAMEN OVALE IN PATIENT WITH INFERIOR VENA CAVA INTERRUPTION

Abstract Percutaneous closure of a patent forame ovale (PFO) is indicated in selected patients with a confirmed cryptogenic stroke, transient ischemic attack (TIA), or systemic embolism and an estimated high probability of a casual role of the PFO as assessed by clinical, anatomical and imaging features. This procedure is usually undertaken from the femoral vein. In this case, the patient was affected by vena cava agenesis with a compensatory enlargement of azygos vein. We performed the percutaneous closure of the PFO using a 9F jugular vein access. We advanced a straight guide trough the foramen with a Multipurpose 6F catheter supported by a Destino Oscor 8F. Then we changed the straight guide with an Amplatz Super-Stiff 0.035" guide in the left ventricle, on which a Mullins 9F trans-septal catheter was advanced. Finally we delivered an Amplatzer Multifenestrated Septal Occluder "Cribriform" 25/25 mm. In our case, it was impossible to perform the PFO closure procedure using the classic femoral vein access due to the inferior vena cava agenesis. Performing PFO closure using the right internal jugular venous approach was technically challenging but safe and it is possible using standard equipment normally present in the Catheterization Laboratory. In rare cases of an indication for PFO closure and lack of access through the femoral veins, alternative techniques using on the shelf materials help in overcoming the challenging anatomies. The use of steerable catheter is critical for engaging the foramen ovale with unfavourable angulation. The procedure with nitinol double disk devices is safe and effective.

Biometry and Intraocular Lens Power Calculation by Combined Scheimpflug-Placido Disc versus Optical Interferometry Devices.

To compare the results of the current gold standard, laser interferometry, and keratometry by the IOL-Master, with a newly developed Galilei G6 using raytracing software Okulix for intraocular lens (IOL) power calculations. For comparison of the IOL-power calculation of both devices, we analyzed the difference between the actual one-month postoperative subjective refraction and the theoretically calculated target refraction before cataract surgery. The IOL was selected according to the IOL Master recommendation aiming for emmetropia after surgery.We analyzed the differences of the measurements of the basic biometric data in 205 healthy eyes by each device. Our study included 205 healthy, unoperated eyes from 117 patients (61 women, 56 men) aged 20 to 75 years. Twenty-two eyes of cataract patients were also included in this retrospective study design. The mean difference between the prediction of the postoperative refraction and the refraction actually achieved was 0.03 D for the IOL Master and -0.23 D for the Galilei G6. The difference was not statistically significant (P = 0.059). The difference between the IOL power calculation of the IOL Master and the calculation of the G6 was not statistically significant (P = 0.064). The difference between the predicted refraction of the G6 and the refraction achieved after one month was also not statistically significant (P = 0.12) and neither was the difference between the predicted refraction of the IOL Master and the achieved refraction (P = 0.39). The mean axial length was calculated as 24.21 0.80 mm using the IOL Master and 24.27 0.82 mm using the Galilei G6 device. The mean value regarding anterior chamber depth (ACD) of the IOL master was 3.46 0.23 mm and for the Galilei was G6 3.51 0.25 mm. When comparing the white to white (WTW) values of the IOL master, it showed mean values of 12.32 0.31 and Galilei showed mean values of G6 12.21 0.28. All of these differences (between Galileo and IOL Master measurements) were statistically significant (P 0.001). Both the laser interferometry/keratometry performed by the IOL Master and the interferometry/raytracing biometry strategy performed by the Galilei G6 demonstrated equal results when executing the IOL power calculation before cataract surgery in eyes with no prior ocular surgery.

Silver-ligand complex as an additive in polymeric membranes of screen-printed fluoride-selective electrodes

Fluoride-selective electrodes with membranes containing zirconium porphyrin and dithizone-silver complex were developed. Silver disc electrodes and devices fabricated by screen-printing with silver ink were used as transducers. Dithizone-silver complex ensures potential stability of prepared electrodes, forming a redox couple with silver metal transducers. Moreover, it serves as lipophilic cationic site in the membrane, inducing zirconium porphyrin to act as a neutral ionophore. Electrodes with these membranes showed the following selectivity sequence: ClO4− > F− > NO3– > Cl−. Linear response towards fluoride was observed from 10−4 M to 10–1 M. Charged carrier mechanism is also possible, requiring polar plasticizer and addition of anionic lipophilic sites to the membrane. While membranes with ionophore working as charged carrier show better discrimination of lipophilic anions (selectivity sequence: F− > ClO4− > NO3– > Cl−), dynamic range of fluoride response is narrower in this case (10−4 M to 10−2 M), as compared to membranes with ionophore working as neutral carrier. Screen-printed electrodes with membranes containing dithizone-silver complex were integrated with reference electrodes with membranes containing ionic liquid, prepared on the same transducers. These devices were successfully employed for determination of fluoride ion in pharmaceutical samples.

ТЕХНОЛОГИЧЕСКОЕ ОСНАЩЕНИЕ ДЛЯ ОПТИМИЗАЦИИ ПЛАЗМЕННОГО НАПЫЛЕНИЯ ПО ПАРАМЕТРУ СКОРОСТИ НАПЫЛЯЕМЫХ ЧАСТИЦ

The work is devoted to the issue of optimizing the processes of plasma spraying of coatings according to the criterion of the speed of sprayed particles, which is highly determining the quality of the applied coatings, and technological equipment for this using, first of all, disk devices.

Surface electric properties of polymer films as driving force of charges in noncontact rotating disk device for rotary mechanical energy harvesting

Surface electric properties of polymer films as driving force of charges in noncontact rotating disk device for rotary mechanical energy harvesting

On the tribological performance of laser-treated self-lubricating thin films in contact with rubber

The tribological processes still cause a significant increase in energy consumption worldwide. In this work, we deposited self-lubricating coatings for the purpose of reducing friction during sliding against rubber. One of the coatings was also treated with laser. We studied the morphological, structural and mechanical properties of the proposed solutions. Tribological tests were performed using a pin on disk device. The laser treatment improved the crystallinity of the WSx phase. This improvement was coupled with a reduction of the hardness in the laser-treated areas due to graphitization. The laser-treated sample showed a reduction in friction only during the initial stages of sliding. The lowest friction was observed during the testing of unalloyed sputtered WSx coating, but it suffered more wear.

Significance of radiative magnetohydrodynamic flow of suspended PEG based ZrO2 and MgO2 within a conical gap

The underlying intension of this study is to oversee the flow and thermal management of hybrid nanofluid (Magnesium oxide+ Zirconium oxide+ polyethylene glycol) within a conical gap among a cone and a disk. Forced convection is examined for two situations (a) rotating disk and the stationary cone; (b) stationary disk and the rotating cone. The dimensionless differential system for the proposed model is numerically simulated with a shooting procedure (RK 4th order). Outcomes are explained through graph and tables. The main outcomes of this study are found to be – Rotating disk and stationary cone show higher temperature field for increasing estimations of the radiation parameter () and the magnetic parameter () near the boundary. Hence, for heat enhancement, one can use the disk – cone model. Furthermore, increases in and shows an increment in Nusselt number at the cone surface compared to that at the disk surface. The desired cooling in the disk and cone device could be attained by keeping the cone fixed and the disk rotating and by maintaining the surface temperature constant. It is perceived that improvement in the volume fraction of and nanoparticles significantly enhanced velocity of base fluid and heat transfer rate.

Analysis of the Influence of Contamination in Lubricant by Biodiesel in a Pin-On-Disk Equipment

The introduction of biodiesel to commercial diesel is being increased every year. The need to check this addition to the engine and lubricant is important for automakers and internal combustion engine manufacturers. The oil analysis technique is a type of predictive maintenance, done by collecting oil from equipment and analyzing it later in the laboratory, or by analyzing it directly and continuously in on-line systems. In internal combustion engines, all parts have a pre-established service life, longer or shorter, according to the specific function assigned to it. By analyzing the oil, the condition of these parts can be monitored. The oils analysis reveals the first signs of wear of a component. The identification is made based on the study of the number of particles, size, shape and composition thereof, present in the lubricant samples, which provide accurate information about the conditions of the moving surfaces without the need to disassemble the assembly to which these parts belongs. In this work a lubricant contamination by biodiesels were made to simulate possible scenarios within an internal combustion engine.The lubricant recommended by an engine manufacturer was “contaminated” with commercial diesel and with different percentages and types of biodiesel. After this “contamination” they were placed in a pin on disk device under certain conditions.Through the analyzes of the lubricants extracted from the Pin on disk Equipment after the tests, some analysis were carried out in order to study the effects of using biodiesel in the internal combustion engine.These analyzes consisted of Flash point, analytical ferrography, monitoring of ferrous particles generated, viscosity, viscosity index, basicity index and X-ray spectrometry.Among the results obtained it is observed that for a 5% contamination of animal biodiesel there was an increase in the viscosity index. Conversely, the contamination of 5% of animal + vegetable biodiesel decreased the viscosity index in relation to Diesel B5. We also found that these biodiesel additions were not detrimental to the engine and lubricant at the mix ratios and test conditions used.

Scheduling Real-Time Parallel Applications in Cloud to Minimize Energy Consumption

Cloud computing has become an important paradigm in which scalable resources such as CPU, memory, disk and IO devices can be provided to users to remotely process their applications. In a cloud computing platform, energy consumption accounts for a significant cost portion. This article thus aims to present an energy-efficient scheduling algorithm for processing a user application with a real-time requirement. This problem is formulated as a non-linear mixed integer programming problem. We start with providing an optimal closed-form solution to its relaxation problem that aims to minimize the energy consumption without considering real-time requirements. To meet real-time requirements, we propose how to adjust task placement and resource allocation by making a good tradeoff between energy consumption and task execution time. Lastly, we find two equivalent optimal resource allocation strategies once task placement has been done. We then propose to adjust the start time of task execution such that an application’s completion time can be further shortened. Experimental results on two real-case enchmarks and extensive synthetic applications demonstrate that our proposed method finds a schedule that generally has 30 and 20 percent less energy consumption than enhancement heterogeneous earliest finish time (E-HEFT) and genetic algorithm, respectively. Besides, the proposed method has a higher rate to successfully find a feasible schedule than them, and its computation time is close to E-HEFT’s, but far less than the genetic algorithm's.

In vitro additive effects of dalbavancin and rifampicin against biofilm of Staphylococcus aureus

Dalbavancin is a novel glycopeptide antibiotic approved for the treatment of acute bacterial skin and skin structure infections (ABSSSIs). It is characterized by a potent activity against numerous Gram-positive pathogens, a long elimination half-life and a favorable safety profile. Most recently, its application for the treatment of periprosthetic joint infections (PJIs) was introduced. The aim of this study was to proof our hypothesis, that dalbavancin shows superior efficacy against staphylococcal biofilms on polyethylene (PE) disk devices compared with vancomycin and additive behavior in combination with rifampicin. Staphylococcus aureus biofilms were formed on PE disk devices for 96 h and subsequently treated with dalbavancin, vancomycin, rifampicin and dalbavancin-rifampicin combination at different concentrations. Quantification of antibacterial activity was determined by counting colony forming units (CFU/ml) after sonification of the PE, serial dilution of the bacterial suspension and plating on agar-plates. Biofilms were additionally life/dead-stained and visualized using fluorescence microscopy. Dalbavancin presented superior anti-biofilm activity compared to vancomycin. Additive effects of the combination dalbavancin and rifampicin were registered. Dalbavancin combined with rifampicin presents promising anti-biofilm activity characteristics in vitro. Further in vivo studies are necessary to establish recommendations for the general use of dalbavancin in the treatment of PJIs.