Clean Mechanism Research Articles

Direct and Clean Loading of Nanoparticles into Optical Traps at Millibar Pressures

Nanoparticles levitated by optical fields under vacuum conditions have applications in quantum science, the study of nanothermodynamics and precision sensing. The existing techniques for loading optical traps require ambient conditions and often involve dispersion in liquids, which can contaminate delicate optics and lead to enhanced optical absorption and heating. Here, we present a clean, dry and generic mechanism for directly loading optical traps at pressures down to 1 mbar, exploiting Laser Induced Acoustic Desorption and allowing for the rapid and efficient trapping of nanoparticles.

The effects of water purity on removal of hydrophobic substances from solid surfaces without surfactants

HypothesisDetergents used in everyday life for cleaning and washing are a source of water pollution and can have a negative effect on human health and the environment. To reduce their negative impact, a new trend of using only purified water for washing and cleaning applications is emerging. A scientific basis of this method needs to be established, as its mechanisms and the efficiency should be better understood. ExperimentsIn this work, we investigate the effect of water purity on the removal of hydrophobic films from solid surfaces using quartz crystal microbalance with dissipation monitoring (QCM-D) and gravimetric experiments. We compared the cleaning efficiency of TAP water, two grades of purified water, NaCl solution and SDS solution. FindingsThe QCM-D results show that both grades of purified water remove more than 90% of Vaseline deposited of the surface while tap water only 75%. SDS solution fully removes the deposited layer. Gravimetric experiments with removal of olive oil from hydrophilic and hydrophobic surfaces also indicate higher efficiency of purified water grades. Contact angle experiments show that pure water facilitates roll-up mechanism of cleaning. We suggest that due to lower ionic strength, purified water increases electrostatic repulsion and promotes the cleaning process.

Reusable textile microfiber and laundry in healthcare: Critical analysis of problematic published information

Recent analyses of environmental services products and practices in healthcare have covered the concepts of hygienically clean, mechanisms of cleaning, and comparison of reusable and disposable textile microfiber products. In 11 referred papers, it was discovered that three had sufficient factual errors to influence the citations found in the broader literature. This study evaluating these problematic papers is an obligation of the scientific community for accuracy. In light of newer data on the efficacy of important textiles for microfiber cleaning, these previous studies were reexamined to see if methodological corrections are needed. Closer investigation of the authors’ data was used to ascertain the validity of their initial conclusions. These current reevaluations reverse conclusions in these journal articles. It appears factors such as multi-variant statistical comparisons, combining variables, and use of extremely high inoculum for cleaning led to the wrong conclusions in these three papers. The revised results show that for hospital surface cleaning with reusable textile microfiber products, no detectable levels were found for two of the most challenging organisms for hospital-acquired infections, methicillin-resistant Staphylococcus aureus and Clostridium difficile. Commercial laundry was substantially better than hospital laundry and reusable microfiber products improved with use.

On the Concept of Computational Fluid Dynamics-Based Prediction of Cleaning for Film-Like Soils

The removal of film-like deposits is a challenge in many fields of production. For environmental and economic reasons, the cleaning processes need to be optimized. An optimization by means of computational fluid dynamics seems to be beneficial, but is subject to some restrictions, especially in industrial context. General modeling ideas, a subdivision into sub-processes and the significance of time dependent soil behavior are discussed as well as specific concepts related to four basic cleaning mechanisms, namely diffusive dissolution, cohesive separation, viscous shifting and adhesive detachment. Cleaning experiments in fully developed plane channel flow, resembling a simplified plate heat exchanger, are performed with model soils (starch, petroleum jelly, ketchup) which were chosen to represent an almost ideal form of one of the basic cleaning mechanisms.

Design of Power System of Algae Cleaning Mechanism Based On Fuzzy Controller

Aiming at the problem of algae in the South-to-North Water Transfer Project, an algae-clearing mechanism based on fuzzy controller is designed. Use MATLAB software to simulate, establish the simulation model of the fuzzy control system in Simulink module according to the actual situation, select the two-dimensional Mamdani typed fuzzy controller, design the fuzzy control GUI according to the logic algorithm of the fuzzy control theory, and set a reasonable simulation timed to analyse the algae-clearing mechanism The law of the dynamic system. According to the simulation results, the optimal lifting interval timed and high-pressure water spraying time of the algae blocking net are obtained to control the start and stop of the motor and the water pump, so that the controller can be set to achieve the purpose of automatic control. The simulation results show that the method meets the requirements of the actual work of the algae removal machinery, so the fuzzy control system is suitable for the algae removal machinery and realizes the automatic control of the algae removal machinery.

Piezo-enhanced activation of dinitrogen for room temperature production of ammonia

The catalytic conversion of nitrogen to ammonia remains an energy-intensive process, demanding advanced concepts for nitrogen fixation. The major obstacle of nitrogen fixation lies in the intrinsically high bond energy (941 kJ mol−1) of the N≡N molecule and the absence of a permanent dipole in N2. This kinetic barrier is addressed in this study by an efficient piezo-enhanced gold catalysis as demonstrated by the room temperature reduction of dinitrogen into ammonia. Au nanostructures were immobilized on thin film piezoelectric support of potassium sodium niobate (K0.5Na0.5NbO3, KNN) by chemical vapor deposition of a new Au(III) precursor [Me2Au(PyTFP)(H2O)] 1 (PyTFP = (Z)-3,3,3-trifluoro-1-(pyridin-2-yl)-prop-1-en-2-olate) that exhibited high volatility (60 °C, 10–3 mbar) and clean decomposition mechanism to produce well adherent elemental gold films on KNN and Ti substrates. The gold-functionalized KNN films served as an efficient catalytic system for ammonia production with a Faradaic efficiency of 18.9% achieved upon ultrasonic actuation. Our results show that the spontaneous polarization of piezoelectric materials under external electrical fields augments the sluggish electron transfer kinetics by creating instant dipoles in adsorbed N2 molecules to deliver a piezo-enhanced catalytic system promising for sustained activation of dinitrogen molecules.

Elastocapillary cleaning of twisted bilayer graphene interfaces

Although layered van der Waals (vdW) materials involve vast interface areas that are often subject to contamination, vdW interactions between layers may squeeze interfacial contaminants into nanopockets. More intriguingly, those nanopockets could spontaneously coalesce into larger ones, which are easier to be squeezed out the atomic channels. Such unusual phenomena have been thought of as an Ostwald ripening process that is driven by the capillarity of the confined liquid. The underlying mechanism, however, is unclear as the crucial role played by the sheet’s elasticity has not been previously appreciated. Here, we demonstrate the coalescence of separated nanopockets and propose a cleaning mechanism in which both elastic and capillary forces are at play. We elucidate this mechanism in terms of control of the nanopocket morphology and the coalescence of nanopockets via a mechanical stretch. Besides, we demonstrate that bilayer graphene interfaces excel in self-renewal phenomena.

Effect of Physicochemical Properties of Native Starches on Cleaning in Falling Film and Plane Channel Flow Experiments

Reliable cleaning processes are an absolute prerequisite to ensure the production of safe foods. In particular, the cleaning of heat exchangers is a crucial process step since temperature induces the formation of strongly bound food-borne deposits. Aiming on relationships between soil-specific physicochemical properties and cleaning behavior, four native starches of different botanical origin (maize, waxy maize, potato, wheat) were selected for plane channel flow (similar to the flow regime in plate heat exchangers) and falling film cleaning experiments. In addition, their chemical composition and swelling behavior was analyzed. Different cleaning mechanisms could be observed, whereby diffusive dissolution was identified as dominant cleaning mechanism for most starch deposits in both cleaning experiment setups. The cleaning of such soils is characterized by an initial reptation time, where the cleaning fluid penetrates the soil and no cleaning occurs, followed by a period with constant cleaning rate. Since these cleaning parameters where overlapped by swelling-induced processes, a correction model was used to identify the unaffected cleaning progress. The cleaning and swelling-induced parameters were influenced by the origin of the starch as well as by temperature and sodium hydroxide concentration of the cleaning fluid. Multivariate statistics was helpful to unravel interrelationships and interdependencies between results of cleaning experiments, and compositional and physicochemical properties.

Spatiotemporal variability of solid waste on sandy beaches with different access restrictions

Intense human use and high construction density in coastal areas are stressors to sandy beaches. Pollution by marine debris is a major problem on beaches worldwide. This study pioneered an assessment of marine debris characterization over time on beaches with different levels of access. In two periods and seasons, marine debris was sampled on nine sandy beaches of Rio de Janeiro, grouped by levels of access. The general marine debris density has decreased over time, accompanied by an improvement in public cleaning mechanisms. The most important predictor for the majority of marine debris items is related to accessibility; beaches with restricted access showed a reduction in the abundance of most items. High marine debris densities, even on beaches with restricted access, showed that all evaluated beaches can be sinks for marine debris circulating in marine waters. Beach cleaning strategy improvements will be inefficient unless integrated marine debris management is implemented.

Investigating Effects of Operational Parameters on the Rate of Electrochemical Cleaning of Chromium Deposits on Strontium-Doped Lanthanum Manganite Cathodes in Solid Oxide Fuel Cells

Chromium poisoning of the cathode remains a significant obstacle to the long-term performance of solid oxide fuel cells. Previously, a quick, easy method was introduced that requires no material modifications, major thermal cycling, nor exposes the cell to any species it does not already encounter during operation. The method, electrochemical cleaning, reverses the electrochemical deposition reaction of chromium-containing species by applying a mild anodic bias. Chromium vapor species are formed, freeing active sites in the cathode. The method has been shown to completely recover cell performance via this current-voltage technique.The present work investigates the mechanism of electrochemical cleaning by assessing the effect of various operating parameters on the rate of chromium removal. Using a design of experiments method, eight cells were poisoned and then cleaned using differing combinations of the following cleaning parameters: cell temperature, air humidity, anodic current density, and fuel humidity. Regression analysis of two comparative metrics, cell performance via current voltage curves and post-test chromium content determined via Energy Dispersive Spectroscopy, demonstrated that cell temperature has the highest effect on the rate of chromium removal, followed by air humidity. A refined parameter space for future study is proposed for further optimization of the parameters. Previously, the electrochemical cleaning method was shown to be effective in the removal of Cr2O3 deposited species, but not Cr-Mn spinel deposits. The effects of operating parameters on the removal of the two different types of Cr deposits is discussed. An additional process for the removal of Cr-Mn spinel is demonstrated, which again makes use of the cell operating parameters. Together, the two methods present a facile, periodic process to greatly extend solid oxide fuel cell lifetime.

Carbon deposition mechanism of molten salt cleaning and optimization of multicomponent molten salt formula for remanufacturing.

In remanufacturing engineering, cleaning is the key factor for subsequent blank inspection and parts repair. Molten salt has the characteristics of low viscosity, good fluidity, and strong chemical stability. Salt bath cleaning can be comprehensively applied to remove various organic pollutants. Molten salt has the function of self-cleaning. The dirt in the cleaning pool can be decomposed and reused. Moreover, the waste molten salt is massive, and the waste residue is easy to treat. The formation and adsorption mechanism of carbon deposition was explored, and the formation mechanism of carbon deposition was verified by experiments. Then, the existing formula was improved by mixing experiment and compared with the current cleaning method; the cleaning effect was excellent. A new molten salt formula is proposed on the basis of the research on solar thermal storage medium. The composition percentage and the optimal process parameters of the new molten salt formula were determined on the basis of the experimental design of mixture. The cleaning effect of the new formula is good.

Enhancing the efficiency of rooftop solar photovoltaic panel with simple cleaning mechanism

In today’s world, use of renewable energy source is increased to decrease the usage of coal and water for generating electricity. One of the methods is, using solar energy for generating electricity. The efficient use of solar energy is an essential path which can deal with electricity crises. Even it has some problems, like aggregation of dirt and dust on the surface of the solar PV panel decreases the quantity of sunlight to penetrate and reach the solar cells, thereby shrinking the efficiency of PV panel. There are various techniques like manual cleaning, vacuum cleaning, electrostatic precipitator cleaning etc. With this cleaning mechanism, there can be an increase in the efficiency of the panel to about 15–20%. But each of the techniques has some disadvantages associated with it. Manual cleaning requires more manpower and there are some possibilities for damages to the Photovoltaic Panel on continuous usage of water or fluid. Vacuum cleaning mechanism results in scratches on the panel. So, we are using Automatic wiper cleaning using Arduino for cleaning the panel. In this paper we aim to reduce those disadvantages and enhance the efficiency and effectiveness of solar PV panel.

A Self-Powered Solar Panel Automated Cleaning System: Design and Testing Analysis

Accumulation of dusty elements on the surface of the solar photovoltaic (SPV) panel decreases its performance significantly. In this regard, this work presents the design and experimental analysis of a novel self-powered solar panel cleaning mechanism system to clean the SPV panel. The cleaning system is powered by two small SPV panels with rechargeable batteries and does not need power from the solar panel which is to be cleaned. The experimental model is based on three DC motors which are intelligently controlled by dedicated driver units that move a cleaning brush on the solar panel in a dual-axis moving a frame. This work is carried out by the help of the Arduino Uno microcontroller board which effortlessly controls all the connected devices. The experimental results clearly show that there is a substantial increase in the efficiency of the SPV panel. Moreover, the proposed work has been carried out by considering the following aspects: (i) efficacy of anti-soiling (ii) frequency of cleaning and (iii) energy saving (observation on daily, weekly and monthly basis).

Developing a climbing robot for repairing cables of cable-stayed bridges

It is difficult to test and maintain the cables on a cable-stayed bridge. Cable detection and repair remain mainly manual operations and automatic maintenance is rare. Aiming at the difficulty of detecting and repairing damage to bridge cables, a climbing robot system for cable repair based on an independent quadrilateral suspension was designed. Firstly, an independently suspended cable-climbing robot scheme was proposed and the automatic repair mechanism (including a rotary platform, grinding, cleaning, spraying, and winding mechanisms) was designed. Then, a dynamic model for obstacle negotiation by the climbing robot was established to perform simulation and analysis; subsequently, kinematic and workspace analyses were conducted on the component modules of the robot to optimize the structure of the robot. Finally, a prototype of the cable repair robot was developed, and the experimental platform was established to carry out laboratory testing and in-situ testing of a bridge. Furthermore, climbing and repair tests on cables with diameters of 80 to 140 mm were conducted. The experimental results show that the proposed robot that climbs at the speed of 0.26 m/s can carry a mass of 11.5 kg and cross obstacles 15 mm in height. The climbing robot can fulfill automatic repair of damage to bridge cables with the testing, grinding, cleaning, spray coating, and winding mechanism according to the surface damage encountered. Future research should aim to improve the obstacle surmounting ability of the proposed robot.

Novel fine particle reduction method for wood stoves based on high-temperature electric collection of naturally charged soot particles

Air pollution emitted by residential biomass combustion (RBC) is a known cause of adverse health and climate effects. Currently, manufacturers of stoves and fireplaces are facing challenges due to tightening emission regulations, such as the Ecodesign Directive in the European Union. Consequently, there is a demand for new emission control solutions for RBC. Herein, a novel method has been introduced to reduce particulate emissions, namely: high-temperature electric soot collector (HiTESC). In this method, an electrically insulated high-voltage electrode is installed in a combustion chamber, which generates an electric field. Particles that acquire the electrical charges produced by flames are collected on the electrode surface and oxidized at high temperatures. A fine particle (PM1) reduction efficiency of 45% was achieved using this method in a logwood-fired masonry heater. The reduction efficiency of the method was found to be dependent on the combustion phase. The PM1 reduction was most efficient during the flaming conditions, when the PM emissions were the highest with the studied logwood appliance. The advantages of this method are its simple construction, low space requirement, and low energy consumption; further, it does not require a separate cleaning mechanism. The proposed method can be used in logwood-fired combustion appliances to achieve future emission regulation limits, without using costly exhaust after-treatment systems.

Cleaning of Solar Panel using Automation Technique

Solar energy is considered to be one of the best major renewable energy resources to generate and meet the electrical energy demand of the entire globe. Solar PV modules produce electricity by collecting the sunlight. solar PV modules are generally employed in dusty environmental areas like in India, which comes under the tropical region. Various dust particles present in the tropical region, so the dust particles are accumulated on the surface of the solar panel. Therefore, the incident light can be blocked. As a result, the module power capacity can be reduced. If the panel not cleaned properly the power output become reduced by 50%. To increase the power output an automatic cleaning mechanism has been designed. This automatic cleaning mechanism not only senses the dust accumulated on the solar panel but also clean the solar PV module automatically. This solar cleaning mechanism is mainly implemented using PIC 16F 1527 microcontroller, which mainly controls the stepper motor, Air compressor and water pump. The dust can be cleaned by the gantry which is mainly driven by the stepper motor. The gantry has mist nozzles which create pressurized air and water to clean the solar panel effectively. The cleaning can be done by air and water depending upon the dust accumulated on the solar panel. Index Terms: solar panel; micro-controller; stepper motor; dust particles.

Modeling and Analysis of a Glass Façade Robot

For glass façade cleaning, we developed a reconfigurable robot, Mantis-mini, with a dry cleaning mechanism and linear actuator based transitioning mechanism. It consists of three suction modules, connected by a support structure and each suction module has individual differential drive wheels with independent steering capability. This paper focuses on the detailed design of the platform, static structural analysis for and kinematic formulation. The adhesion performance of the suction module is evaluated using experiments, Computational Fluid Dynamics (CFD) simulations, and analytically formulated estimation. The suction pressure magnitude predicted from the simulations increases with suction impeller speed and agrees well with measurements and analytical calculation in terms of order of magnitude and qualitative trend. An adaptive proportional-integral (PI) controller is designed and implemented for regulating suction pressure and motion controller of the platform. The suction performance of the platform is validated through real-time experiments of the platform on the glass surface.

Independent Variation of Reynolds Number, Wall Shear Stress and Flow Velocity for Cleaning Experiments: A Geometrically Flexible Parallel Plate Flow Cell

For a long time, determining the factors influencing the cleaning of technical surfaces in the food and beverage industry has been of significant interest. In this study, an innovative test setup with a newly designed parallel plate flow cell was implemented to assess the cleaning of soluble molecular fouling materials, which allows for the independent variation of flow parameters, such as the Reynolds number, velocity, and wall shear stress. The test setup used fluorescence spectroscopy; it was found to produce reliable measurements of cleaning, and the results were confirmed with the help of another fluorescent tracer. A comparison of cleaning times for both equipment revealed that the cleaning times tend to have a geometrically independent power-law relationship with the wall shear stress and velocity, and they were used to directly correlate the cleaning times of the used soluble fouling material. However, the Reynolds number showed a geometric dependence on cleaning times. Nevertheless, on dividing the Reynolds number with respective channel characteristic lengths, geometric independence was observed, and, therefore, a correlation was obtained. We also suggest that complex fouling materials should still be investigated to elucidate their cleaning mechanisms better and test for parameter influences on complex cleaning mechanisms.

Robust cleaning mechanism permanently detaches hydrocarbon species from silicate surfaces by amphiphiles

This paper studies the role of 1-methyl-2-pyrrolidone (NMP) additive to enhance the desorption power of toluene to detach the bitumen from siliceous surfaces. The latter desorption is critical for successful recycling of old asphalt roads where aged bitumen is expected to come off the stones and blend with virgin bitumen used in construction of new roads. Toluene, a documented neurotoxin, has been commonly used to separate aged bitumen from siliceous surface; increasing toluene desorption power and dosage efficiency allows reduced application rate leading to significant environmental and economic benefits. Here, we used the laboratory experiments and computational modeling to understand mechanism of desorption afforded by a hybrid solvent made from blends of toluene and NMP. Our results showed the hybrid solvent interacts with both bitumen and siliceous surfaces; this in turn allows the solvent not only dissolve the asphaltene agglomerates in aged bitumen, but also supersede bitumen compounds for adsorption to silica. Our modeling revealed the hybrid solvent creates an amphiphile that is both able to attach to the asphaltene molecules and interact with polar water molecules, thus making a monolithic cluster that is easy to detach from the siliceous surface under hydraulic pressure. This was further evidenced in a high reduction in the shear-thinning rate of bitumen-silica matrix when hybrid solvent was introduced; for instance, in the case of severely aged bitumen bonded to silica, shear-thinning rate reduced by 60% when hybrid solvent was introduced. Study outcomes provide insights into the merits of using hybrid solvent for desorption as well as its working mechanism. Such insights set a path for future efforts in pavement recycling and promote resource conservation and sustainable development.

Experimental Analysis of Solar PV Module by Cleaning & Cooling for Optimizing Efficiency

Sun-oriented energy is a resource of energy on earth. Sun-based energy can be gotten as warmth to create power or it is additionally conceivable to change over sun-based energy straightforwardly into power. The main objective of this project is to catch maximum solar radiation from the sun and increase the overall efficiency of solar panels. To design a cleaning mechanism that runs across the length of the panel. To avoid dust-associated problems on the solar panels. The temperature in case of water cooling system was lowered down to 410C from the ambient temperature 440C at 14:00 in the morning of 21/09/2020. The power output was 4.789W and in case of set up having dust on the surface of the solar panel the temperature rose to 490C with power reduced to 4.00185W. The temperature in case of water cooling system was lowered down to 400C from the ambient temperature 430C at 14:00 in the morning of 22/09/2020. The power output was 4.89W and in case of set up having dust on the surface of the solar panel the temperature rose to 490C with power reduced to 4.00185W. The outcomes for day 3 of the experimentation were also recorded on 23/09/2020 and the setup with a cooling system produces a maximum power of 5.20 W by lowering the temperature to 370C from the maximum ambient temperature of the day 410C