Recent achievement and progress in solar PV play a significant role in controlling climate change. This study reviewed comprehensively electrical characteristics, life cycle of dust, optical ...characteristics, and different cleaning techniques related to the effect of dust on the performance of PV modules throughout different climate regions of the world. The power maximum power point (MPP) and curve of PV module under the effect of irradiance and temperature were presented. The effect of dust (shading) on the electrical efficiency of PV module was discussed based on soft, partial, and complete (soiling) shading. The physical properties of dust around the globe such as PM10 concentration, dust loading (mgm−2), and fine dust particles concentration were covered and discussed. Reasons behind the accumulation of dust based on, location and installation factors, dust type, and environmental factors. Environmental reasons causing dust and dust removal in accordance with the life cycle of dust was covered in detail. All the reasons that cause the generation, accumulation and removal of dust during its life cycle were explained. All forces responsible for the adhesion phase of the dust life cycle were presented. The effect of dust on PV module transmittance and electrical parameters module were discussed in detail based on physical properties of the dust at its location and installation conditions. Self-cleaning super hydrophobic surfaces based on methods such as solvents, vapor-assisted coating, powder coating, and polymerization were discussed. All cleaning technologies, including self-cleaning technologies, based on the material coating used, and the manufacturing of PV cells was compared. The future prospective for PV technologies and cleaning methods were also covered.
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•The effect of dust (shading) on the electrical efficiency of PV module was discussed.•The physical properties and life cycle of dust around the globe were covered.•The effect of dust on PV module transmittance and electrical parameters module were discussed.•Self-cleaning super hydrophobic surfaces and all cleaning technologies were discussed.•The future prospective for PV technologies and cleaning methods were also covered.
Multifunctionalization is the future development direction for microwave absorbing materials, but has not yet been explored. The effective integration of multiple functions into one material remains ...a huge challenge. Herein, an aerogel‐type microwave absorber assembled with multidimensional organic and inorganic components is synthesized. Polyacrylonitrile fibers and polybenzoxazine membranes work as the skeleton and crosslinker, respectively, forming a 3D framework, in which carbon nanotubes are interconnected into an electrically conductive network, and Fe3O4 nanoparticles are uniformly dispersed throughout the aerogel. Remarkably, the microwave absorption performances of the aerogel achieve ultralight, ultrathin (1.5 mm), and strong absorption (reflection loss of −59.85 dB) features. In particular, its specific reflection loss values considerably outperform the current magnetic–dielectric hybrids with similar components. Moreover, the aerogel possesses strong hydrophobicity and good thermal insulation, endowing it attractive functions of self‐cleaning, infrared stealth, and heat insulation that is even comparable to commercial products. The excellent multifunction benefits from the cellular structure of aerogel, the assembly of multidimensional nanomaterials, and the synergistic effect of organic–inorganic components. This study paves the way for designing next‐generation microwave absorbing materials with great potential for multifunctional applications.
A multifunctional microwave absorbing aerogel is designed and synthesized by assembling a variety of organic and inorganic components including polyacrylonitrile fibers, polybenzoxazine membranes, carbon nanotubes (CNTs), and Fe3O4 nanoparticles. This lightweight aerogel not only achieves excellent microwave absorption performances that outperform the current CNT‐based magnetic–dielectric hybrids, but also possesses self‐cleaning, infrared stealth, and thermal insulation functions.
Summary
This paper presents a novel method to remove spent grains efficiently from filter cloths via pulsed forward flushes. In breweries, mash filters separate liquid wort from solid spent grains, a ...by‐product. These mash filters use woven fabrics made from synthetic materials as filter media. However, rough filter surfaces often hinder the cleaning process. Concerning modern hygienic design principles, filter cloths are only designed for efficient filtration performances, in which cleanability is not considered. Hence, in combination with strongly adhesive spent grains, brewers often reject mash filters. The paper illustrates an experimental parameter variation and a comparison of pulsed with continuous cleaning in respect to their cleaning performance. The results showed that the proposed method is suitable, reaching up to 30% higher cleaning degrees than conventional methods. Furthermore, the technique required up to 50% fewer cleaning fluids and shorter cleaning times, indicating economic and ecological advantages.
Pulsed forward flushes were identified as a promising cleaning concept for mash filters of a brewery. From an economical and ecological point of view, cleaning becomes more efficient when using pulsed jets. This paper combines a parameter variation with a novel technique to detect spent grains on a contaminated filter cloth surface.
•The development history of laser cleaning is reviewed.•The specific action mechanisms of laser dry cleaning, liquid-assisted laser cleaning, and laser shock wave cleaning are described.•The ...influence of essential laser parameters on the cleaning effect is discussed.•The typical application of pulsed laser cleaning is introduced.
Laser cleaning has become a promising technology due to its green, environmentally friendly, and efficient features. It will gradually replace the traditional cleaning processes such as mechanical, chemical, and ultrasonic. As the most potential cleaning technology in the 21st century, laser cleaning is regarded as the "subverter" of the cleaning world. Due to many laser cleaning objects, various cleaning conditions, and strict cleaning requirements, there are still many problems in the efficiency and intelligence of laser cleaning technology and equipment. Based on many experiments and theoretical research, this paper expounds on the specific action mechanism of three laser methods: laser dry cleaning, liquid-assisted laser cleaning, and laser shock wave cleaning in detail. The effects of essential laser parameters such as laser intensity, wavelength, pulse width, and incident angle on the cleaning effect are discussed. The typical applications and cleaning process parameters of pulse laser technology in cultural relics protection, industrial metal surface treatment, semiconductor industry, and optical lens are presented. The existing problems and future development trends of laser cleaning are pointed out, which provides essential engineering practical value for clarifying the multi-action mechanism between laser and the cleaned object and establishing the cleaning process database.
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Amplified interest in maintaining clean indoor air associated with the airborne transmission risks of SARS-CoV-2 have led to an expansion in the market for commercially available air cleaning ...systems. While the optimal way to mitigate indoor air pollutants or contaminants is to control (remove) the source, air cleaners are a tool for use when absolute source control is not possible. Interventions for indoor air quality management include physical removal of pollutants through ventilation or collection on filters and sorbent materials, along with chemically reactive processes that transform pollutants or seek to deactivate biological entities. This perspective intends to highlight the perhaps unintended consequences of various air cleaning approaches via indoor air chemistry. Introduction of new chemical agents or reactive processes can initiate complex chemistry that results in the release of reactive intermediates and/or byproducts into the indoor environment. Since air cleaning systems are often continuously running to maximize their effectiveness and most people spend a vast majority of their time indoors, human exposure to both primary and secondary products from air cleaners may represent significant exposure risk. This Perspective highlights the need for further study of chemically reactive air cleaning and disinfection methods before broader adoption.
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•The importance of effective pretreatment and cleaning protocols in MD is stressed.•Fouling processes in MD and their effects on performance are outlined.•Pretreatment options and ...cleaning strategies for MD are reviewed in detail.•The development of fouling-resistant membranes is discussed.•Suggestions for future research are given to facilitate MD commercialisation.
Membrane distillation (MD) is an emerging thermal-based membrane technology that has the capacity to treat a wide range of feed waters, including high salinity brines and wastewater. Compared with pressure-driven processes, MD has the following advantages: low electrical energy consumption, complete removal of non-volatile solutes and ambient operating pressures. On the other hand, membrane fouling and pore wetting remain a challenge holding back its wider industrial implementation. To manage this issue, effective pretreatment and cleaning strategies are essential, as with other membrane processes. Despite the importance of these aspects for achieving a stable and reliable water treatment process, far too little attention has been paid to them in the MD literature. Evidence of this is that a comprehensive review on both membrane cleaning and pretreatment in MD is still lacking, despite the large and growing number of publications related to the technology. In this work, we first provide an overview of the three main types of fouling present in MD: inorganic, organic and biological fouling. After this we review, in detail, the use of pretreatment protocols in a range of MD applications, highlighting their efficacy in preventing fouling and ensuring stable performance. Next, we review the use of state-of-the-art chemical and physical cleaning strategies and discuss the development of ‘self-cleaning’ membranes that are superhydrophobic or omniphobic. Finally, future research directions are suggested, with the aim of helping researchers working in this field to develop membrane distillation technology towards wider commercial implementation.
The effect of pleat shape on the reverse pulsed-jet cleaning of pleated filter cartridges was investigated in this study with the objective of improving the cleaning efficiency and quality. Pleated ...filter cartridges have been implemented in continuous particle filtration systems equipped with reverse pulsed-jet cleaning technique for filtration unit regeneration. Previous studies have shown that the local sharp variation and non-uniform distribution of static pressure on the surfaces of pleated filter media often result in the decrease in the efficiency and quality of reverse pulsed-jet cleaning as well as the service lifetime of filtration units. In this study a CFD model to calculate the transient flow and pressure fields in a simple filtration system with one filter cartridge during the reverse pulsed-jet cleaning process was developed via ANSYS CFX R.14. The transient static pressure fields for cartridges with four pleat shapes were studied. Significant non-uniformity of static pressure on the high pressure side of filter media for cartridges with typical V-shaped pleats was observed. Significant reduction in the spatial variation of static pressure on the surfaces of pleated filter media for cartridges with other studied pleat shapes was also observed when compared with those for cartridges having V-shaped pleats. A filter cartridge with pleats in the convergent trapezoidal shape was concluded to achieve the maximum and uniformity of static pressure on the filter surfaces and maximal pressure drop across filter media in the reverse flow cleaning. Significant improvement of cleaning efficiency and quality are expected when using filter cartridges with convergent trapezoidal pleats.
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•First study of the pleat shape effect on the cleaning of pleated cartridges•The shape of pleats has its effect on the pressure drop across pleated cartridges.•Pleat tip opening improves the uniformity of pressure on inner surfaces of pleats.•Trapezoidal pleat shape is a better candidate for pleating filter cartridges.
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