Reflective Materials Research Articles

Synthesis, Optical Performance Characterization, and Durability of Electrospun PTFE-PEO Materials for Space Applications.

Passive heat management is crucial in space, especially for extended missions involving protection from sunlight. Thermal coatings with desirable optical properties can drastically reduce the power consumed by active cooling systems, thereby reserving more resources for other critical systems onboard. Specifically, materials with wavelength-dependent reflectance and emittance are desirable for managing incident sunlight and self-cooling by thermal emission. This study demonstrates the use of polymer nanofibers, specifically poly(tetrafluoroethylene) (PTFE), for passive temperature control in space applications. This study describes the electrospinning fabrication process to create nanofibers and how process parameters can be varied to control the fiber geometry. We combine poly(tetrafluoroethylene) (PTFE) and poly(ethylene oxide) (PEO) polymers to fabricate highly reflective thermal control materials by electrospinning. To understand the role of material and fiber geometry, we measure spectral reflectance, absorptance, and transmittance using spectrophotometers interfaced with integrating spheres. We control the materials' fiber geometry and solar reflectance by modifying the solution properties, flow rate, rotating collector speed, and fabrication time. With 220-1560 μm thick electrospun nanofiber materials, we demonstrate an average solar reflectance of 94.73-99.75%, with values approaching 99.9% for thicker samples, which is among the highest for space applications. Meanwhile, a thermal emittance of 81.4% was observed at 300 K for a 3360 μm thick sample. The durability of these samples was also tested under ultraviolet light and atomic oxygen. Compared to the state-of-the-art materials, the electrospun PTFE-PEO fibers present a new paradigm for passive thermal management in space applications.

ESPORTS: PHILOSOPHICAL PERSPECTIVES

<p>Esports are increasingly popular and are becoming more similar to conventional sports. This is due to the social interaction and community-building aspects, as well as the sporting elements embedded in the virtual environments of the video games they include. Esports are a topic of interest for the interdisciplinary field of Philosophy of Sport, which examines the various dimensions of sport in relation to human values. The aim of this paper is to illuminate the existing philosophical debate on the relationship between esports and the Philosophy of Sport. The paper is a philosophical work that aims to highlight the arguments of sports philosophers on esports over the last twenty years. The argument of this paper is that the focus of philosophical interest is not located in matters of ethics but also not in the human being itself. The majority of philosophical papers on esports focus on whether they can be considered real sports or Olympic sports. Other topics include their definition or institutionalisation, physicality, skill requirements, cheating, and corruption. Rules and the identity of esports players are also of concern to philosophers in the field of Philosophy of Sport. This research is significant due to its relevance and timeliness in the field of esports, as well as its contribution to philosophical discussions surrounding the topic. By advancing both philosophical and empirical research and providing ample material for reflection and debate, the paper is a valuable resource for researchers interested in studying and reflecting on esports.</p><p> </p><p><strong> Article visualizations:</strong></p><p><img src="/-counters-/soc/0777/a.php" alt="Hit counter" /></p>

Artificial ground reflector size and position effects on energy yield and economics of single‐axis‐tracked bifacial photovoltaics

AbstractArtificial ground reflectors improve bifacial energy yield by increasing both front and rear‐incident irradiance. Studies have demonstrated an increase in energy yield due to the addition of artificial reflectors; however, they have not addressed the effect of varying reflector dimensions and placement on system performance and the impact of these parameters on the reflectors' financial viability. We studied the effect of high albedo (70% reflective) artificial reflectors on single‐axis‐tracked bifacial photovoltaic systems through ray‐trace modeling and field measurements. In the field, we tested a range of reflector configurations by varying reflector size and placement and demonstrated that reflectors increased daily energy yield up to 6.2% relative to natural albedo for PERC modules. To confirm the accuracy of our model, we compared modeled and measured power and found a root mean square error (RMSE) of 5.4% on an hourly basis. We modeled a typical meteorological year in Golden, Colorado, to demonstrate the effects of artificial reflectors under a wide range of operating conditions. Seventy percent reflective material can increase total incident irradiance by 1.9%–8.6% and total energy yield by 0.9%–4.5% annually after clipping is considered with a DC–AC ratio of 1.2. Clipping has a significant effect on reflector impact and must be included when assessing reflector viability because it reduces reflector energy gain. We calculated a maximum viable cost for these improvements of up to $2.50–4.60/m2, including both material and installation, in Golden. We expanded our analysis to cover a latitude range of 32–48°N and demonstrated that higher‐latitude installations with lower energy yield and higher diffuse irradiance content can support higher reflector costs. In both modeling and field tests, and for all locations, the ideal placement of the reflectors was found to be directly underneath the module due to the optimized rear irradiance increase.

Comparing the electrochemical mechanisms and microhardness of Ni electrodepositions on multilayer Mo/Si and monolayer Pt films at different temperatures

Recently, Ni electroforming is playing an indispensable role in modern optical manufacturing, and multilayer molybdenum/silicon (Mo/Si) film is a promising reflective material with potential applications in soft X–ray/EUV microscopy and astrophysical research. Therefore, the multilayer Mo/Si mirrors (MLMs) fabricated by Ni electroforming is highly expected, where the electrochemical process and deposition quality need to be clarified firstly. In this study, the temperature impacts on the electrochemical reaction dynamics and nucleation mechanisms of Ni electrodepositions on multilayer Mo/Si and monolayer Pt films were compared, and the variations in crystallization growth and microhardness were further discussed. The results showed that the apparent activation energy of Ni electrodepositions on Mo/Si and Pt films was 24.36 kJ/mol and 17.69 kJ/mol, respectively, while the increase in temperature had the similar depolarization influence on both films by positively shifting the reduction potential. In the meanwhile, the 3D instantaneous mechanism remained as the initial nucleation mode for Ni electrodepositions on multilayer Mo/Si film, while as temperature rose, the grain growth gradually changed from a highly coarse and large–sized pyramidal structure to a more refined cluster mode. Nevertheless, the grain texture for Ni electrodepositions on monolayer Pt film evolved from a regularly cone shape to an unevenly elliptical colony–like morphology, primarily ascribed to the progressive nucleation procedure along with higher hydrogen evolution at elevated temperature. Consequently, the appropriate increase in deposition temperature effectively encouraged the rapid development of particular crystal planes and modified the microscopic quality of microhardness, which provided a reference for optimizing fabrication of metallic mirror based on Ni electroforming.

NUMERICAL HEAT TRANSFER ENHANCEMENT OF SOLAR RECEIVER TUBE OF PARABOLIC TROUGH COLLECTOR USING FIBERFRAX 140 COATED WITH AL 2O 3

Parabolic trough collectors (PTCs) play a vital role in solar-thermal energy conversion, with the absorber tube being central to heat collection efficiency. This study investigates the potential for improving heat transfer within the PTC absorber tube using Fiberfrax 140 coated with Al 2O 3 as a novel reflector material. The research is driven by the ongoing pursuit of enhanced PTC performance. A standard modeling approach was employed, utilizing Computational Fluid Dynamics (CFD) analysis with SolidWorks Flow Simulation software, coupled with solar simulations to assess collector performance under varying conditions. Environmental parameters of Bauchi such as temperature, humidity, and wind speed were sourced from the Nigerian Meteorological Agency (NiMet). Optimization techniques were implemented to establish the optimal design configuration. The optimal design parameters were determined as a focal length of 700mm and a rim angle of 90°. Simulations were conducted daily from 8:00 AM to 5:00 PM, encompassing the period of January to June. A mass flow rate of 0.2 kg/s, informed by existing literature, was employed in the simulations. The results indicate improved collector performance throughout the simulated period, with peak thermal efficiency ranging from70%to82%.

Research on Light Pollution Based on AHP and Fuzzy Comprehensive Evaluation Methods

In the current context of increasing global light pollution, we urgently need an effective control system. In this study, we constructed an extensive and objective evaluation model through the AHP method to classify light pollution into standard and index layers, and successfully established an evaluation model that accurately predicts the level of light pollution. Through practical tests, we found that light pollution is higher in cities, followed by suburbs, and lower in rural areas and protected areas. Based on the established evaluation model, we propose three most effective intervention strategies: regulating the use of LED billboards, reducing the use of reflective building materials, and controlling nighttime construction lighting. In response to the possible negative impacts, we propose specific solutions and verify the effectiveness of the intervention programs through a multi-objective planning model, achieving significant results in reducing light pollution levels. This study provides a useful reference and lesson for light pollution management.

Design And Fabrication of Solar Rechargeable Multipurpose Electric Cart for Small Scale Vegetable Vender

The solar-operated cycle cart for small-scale vegetable transportation is an impersishable and innovative solution designed to address the problems faced by local farmers and vendors. This project integrates renewable energy technology with a conventional cycle cart, providing an eco-friendly alternative to traditional manual methods or fossil fuelpowered carts. The system incorporates a photovoltaic panel mounted on the cart's roof, harnessing solar energy to charge a high-capacity battery. This stored energy powers an electric motor that assists the rider in propelling the cart, reducing the physical exertion required for transporting vegetables. The design includes a lightweight and durable frame to optimize energy efficiency and enhance the cart's load-carrying capacity. The inclusion of a user interface allows the operator to monitor battery levels and system performance. Additionally, safety features such as efficient braking systems and reflective materials enhance visibility, especially during low-light conditions. This solar-operated cycle cart not only promotes sustainable transportation but also contributes to minimize carbon emissions corelated with conventional modes of vegetable transport. By converting sunlight into electricity, the project aims to enhance the livelihoods of small-scale farmers and vendors, offering an affordable and environmentally friendly solution for their daily transportation needs

Photonic spin Hall effect under the action of a full-angle three-dimensional magnetic field in space

In this paper, we have measured the magneto-optical spin Hall effect influenced by an arbitrary oriented magnetic field using CeDyAl thin films on Gd3Ga5O12 (GGG) substrates as reflective materials. Plots of the variation of the magneto-optic spin Hall effect (MOPSHE) with magnetic field strength, the hysteresis line, in three different unit-direction magnetic fields are simulated and experimentally measured. The comparison of the simulation results with the experiments allows the method of weak measurement to determine the MOPSHE under the influence of the magnetic field to be validated. MOPSHE under a three-dimensional magnetic field is measured and the measurement error is within 4 μm.

Investigating the influence of reflective materials on indoor thermal environment and solar reflectance in buildings

This in-depth study explores the intricate dynamics of reflective materials, emphasizing their impact on the indoor thermal environment and urban heat island (UHI) mitigation. Examining diffuse highly reflective (DHR), general reflective (GR), and retro-reflective (RR) materials on a simplified building model during summer days, the research utilizes outdoor experiments to analyze air and surface temperatures, as well as solar radiation. Prioritizing key metrics—mean radiant temperature (MRT), operative temperature (OT), and solar reflectance (ρ)—the study uncovers nuanced distinctions in DHR, GR, and RR materials. Solar reflectance calculations consistently show higher values for DHR and RR materials compared to GR material, highlighting reflectance's pivotal role in influencing surface temperatures and indoor thermal environment. When evaluating the impact of exterior wall materials on building temperatures, RR material with a 76% reflectance performs similarly to DHR material (82%). Notably, with a 6% lower reflectance in RR, the temperature contrast between external and internal walls is only about 1.5 °C at its maximum, underscoring RR's effectiveness as an outer wall material for UHI mitigation and building energy conservation, surpassing both DHR and GR materials.

Reflector materials on benches act as supplementary sources of light in rucola cultivation

The purpose of this work is to present an alternative to the use of lamp and light diodes to increase production systems that lead to better natural energy use and better plant development. The species Euruca sativa L. was used, cultivated under a protected environment, and four treatments were taken (control; glossy white laminate; bright red laminate; aluminized thermoreflective screen). Our findings showed to reduce the efficiency of laminated reflective materials in increasing rucola production. The application of the red laminate with greater efficiency, positive results with the increase of fresh matter and number of leaves, increasing the energy efficiency of the plant. Furthermore, the better use of natural light can reduce production costs, since the application of artificial light generates an increase in fixed production costs.

Impacts of Emergency Vehicle Marking Characteristics and Wearable Lights on Driver Responses

Retroreflective markings provide important visual information to drivers about emergency vehicles and the incidents at which they are working. A stationary outdoor field study to investigate the impacts of emergency vehicle marking color, retroreflectivity level, and spatial patterns on drivers’ ability to see nearby emergency responders was carried out. The study also examined the impacts of a wearable flashing light-emitting diode (LED) light. Based on the results, agencies should use materials with higher levels of retroreflectivity carefully, especially when they will be covering large-area vehicle surfaces. Limiting the maximum retroreflectivity level to no greater than American Society for Testing and Materials Type III may help lessen negative impacts of bright reflective materials on drivers’ ability to see emergency responders. As long as the average reflectivity of different color combinations is similar to that of red and yellow reflective markings, chevron patterns with those color combinations will not reduce emergency responder visibility. Outline patterns of reflective markings on vehicles performed similarly at night to patterns covering most of the vehicle surface. The effectiveness of using high-retroreflectivity materials in an outline pattern in combination with lower- (or non-) retroreflectivity materials elsewhere on the surface should be studied. Wearable flashing LED lights can make emergency responders easier to see at night, provided they do not increase glare to approaching drivers.

Blood, obsidian, and the Teotihuacan cult of the mirror

Abstract Drawing upon iconological theory, this article argues that mirrors and blood were regarded as a conceptually linked pair within the imperial ideology of Teotihuacan, Mexico from the second century onward. The relationship between blood and mirrors is shown to have codified with the construction of the Pyramid of the Feathered Serpent, Teotihuacan's third largest edifice. This monument's facade was adorned with hundreds of monumental sculptures of oracular mirrors, some number of which incorporated actual mirrors formed of obsidian. I demonstrate that the Teotihuacan mirror sign took obsidian, a form of black volcanic glass that was intensively worked in the city, as a key referent. This monument was also the site of a historically large human sacrifice of more than 200 individuals, an event argued here to have involved bloodletting with obsidian knives and blades. I note that Teotihuacan interest in the mirror icon increased in concert with the city's residents’ application of the reflective material of obsidian to warring and other blood-spilling behaviors. The mirror icon evoked both obsidian as a radiant material, as well as obsidian's potential for application to forceful martial actions. The article concludes that this icon in part signified imperial force, which was made real through the weaponization of the smoking glass.

Intrapapillary hemorrhage with adjacent peripapillary subretinal hemorrhage of both eyes after COVID-19 infection: a case report

BackgroundIntrapapillary hemorrhage with adjacent peripapillary subretinal hemorrhage is commonly observed in myopia with tilted optic disc. It presents with typical features on the fundus and follows a self-limiting course. However, due to its complex etiology, clinicians sometimes lack sufficient understanding of it which can easily lead to misdiagnosis or overtreatment. In this case report, we describe a rare case of intrapapillary hemorrhage with adjacent peripapillary subretinal hemorrhage in both eyes.Case presentationAn 18-year-old female who has no past medical history experienced sudden black shadow blocking of her right eye in the right eye for the past 2 days after a 5-day history of COVID-19 infection. The best corrected visual acuity is 0.5 in the right eye and 0.6 in the left eye. Optical coherence tomography (OCT) showed tilted optic discs in both eyes, bulged nasal optic discs, and the presence of strong reflective material under the parafoveal retina of the optic discs. Fundus fluorescein angiography (FFA) showed subretinal fluorescence occlusion above and nasolateral to the optic disc in the right eye, with hypofluorescence below the optic disc; the subretinal below the optic disc was obscured by vitreous hemorrhage; hypofluorescence was seen in the optic disc region of the left eye.COVID-19 antigen was positive. The patient was in the early stage of the third COVID-19 infection when the disease occurred. We speculate that it may be related to it. After 5 months of conservative treatment, the patient’s hemorrhage disappeared in both eyes and her best corrected visual acuity returned to normal.ConclusionsIntrapapillary hemorrhage with adjacent peripapillary subretinal hemorrhage usually occurs in myopia with tilted optic disc. In most patients, the cause of the bleeding is unknown, but it can gradually resolve under clinical observation or conservative treatment.

Effective Multiplication Factor Analysis of Gas-cooled Reactor using OpenMC code with ENDF/B-VII.1, ENDF/B-VIII.0 and JENDL-5.0 Nuclear Data

As the demand for nuclear energy keeps rising, Generation IV reactor designs continuously improve. One such potential reactor design is the Gas-cooled Reactor. Neutronic analysis is the foundation for ongoing design modifications and alternatives for the Helium Gas-cooled Reactor. An important aspect of neutronic analysis is the nuclear data library. This research compares how different nuclear data libraries impact a Helium Gas-cooled Reactor design by comparing the neutron effective multiplication factor (k-eff) value. This research was conducted by the Monte Carlo method using OpenMC code. ENDF/B-VII.1, ENDF/B-VIII.0 and JENDL-5.0 were used as nuclear data libraries to simulate the reactor design for ten years of depletion time with 1-year timesteps. The reactor is designed in two different spectrums: the fast neutron spectrum design and the thermal neutron spectrum design. The differences between the two designs are in the cladding and reflector materials where the thermal neutron spectrum uses graphite moderator. The results for thermal spectrum design show that while each nuclear data library’s average k-eff values vary, they all produce the same results at timestep zero, with k-eff values around 1.02500. The average k-eff value from simulation using the ENDF/B-VII.1 library is 1.01477, the average k-eff value from simulation using the ENDF/B-VIII.0 library is 1.01122, and the average k-eff value from simulation using the JENDL-5.0 library is 1.01047. Each simulation result has an average uncertainty of 0.00040. The difference is due to the different amounts of data in each library. JENDL-5.0 has the highest amount of data inside its nuclear libraries, followed by ENDF/B-VIII.0 and ENDF/B-VII.1. Meanwhile, the average difference between the different libraries is insignificant for the thermal gas-cooled reactor simulation results. ENDF/B-VIII.0 produces an effective k-average of 1.04437, and JENDL-5.0 produces an effective k-average of 1.04273. Mass change over time results also shows that the transmutation of Uranium-238 into Plutonium-239 occurred. The fast spectrum reactor design shows a greater increase in plutonium-239 than the thermal spectrum design. The three libraries used did not show large differences in results in calculating changes in the mass of Uranium-238 over time due to Uranium-238‘s large mass, but they still showed differences in Plutonium-239‘s mass change over time. The average value difference between libraries in the fast neutron spectrum reactor design is 50 kg, and in the thermal spectrum it is 30 kg.

Confucian Culture and Democratic Values: An Empirical Comparative Study in East Asia

AbstractMany studies have been conducted on the link between Confucianism and democratic values in East Asia, but they have failed to account for the complex character of Confucianism and the possible impact of political systems. This study re-measures Confucian values into four dimensions—authoritarianism, familialism, collectivism, and harmoniousness—based on data from the fourth wave of the Asian Barometer survey. It then uses a multi-layer linear regression model to examine the relationship between the Confucian cultural values and the democratic values held by people in six East Asian societies at both the macro and micro levels. The findings demonstrate an asymmetrical pattern in the relationship between the various dimensions of Confucian cultural values and the democratic values of East Asia, collectivist values do not affect democratic values, while familial and authoritarian values have a significant and negative correlation with democratic values. Harmonious values have a significant and positive correlation with democratic values. In addition, there is a significant positive correlation between democratic institutions and the democratic values, and the relationship between the values of harmoniousness and collectivism and democratic values varies across countries with different political systems. This offers insightful material for reflection as we reconsider the connection between Confucianism and democracy in East Asia.

In Situ Synchrotron Investigations of Beam Diameter Influence on Vapor Capillary Formation during Laser Beam Welding of Copper Alloy with a Blue Laser Beam Source

Laser beam welding as a reliable tool for high-precision joining of batteries or microelectronics is more and more the choice for achieving reproducible results in production processes. In addition to a high automation capability, the precise control of the energy deposition into the material plays an important role, especially when highly reflective materials, such as copper or aluminum, must be welded together. Alongside the use of highly brilliant fiber lasers in the near-infrared range with a focal diameter of a few tens of micrometers, diode lasers in the wavelength range of 445 nm are increasingly being used. Here, beam diameters of a few hundred micrometers can be achieved. With a wavelength of 445 nm, the absorptivity in copper can be increased by more than a factor of 10 compared to a near-infrared laser beam sources in solid state at room temperature. This paper presents the in situ X-ray observation of laser welding processes on CuSn6 with a laser beam source with a wavelength of 445 nm using synchrotron radiation at DESY Petra III Beamline P07 EH4 in Hamburg, Germany. For the experiments, the laser radiation was focused via two separate optics to focal diameters of 362 µm and 609 µm. To characterize the dynamics of the vapor capillaries depending on the different focal diameters dF, the parameters were varied with respect to laser power PL and feed rate v. For the investigations, a synchrotron beam of 2 × 2 mm2 in size with a photon energy of 89 keV was used, and the material samples were analyzed by means of phase-contrast videography to show the boundaries between solid, liquid, and gaseous material phases. The results of this paper show the welding depths achieved and how the geometry of the vapor capillary behaves by changing the focal diameter, laser power and feed rate.

Characterization of Thin AlN/Ag/AlN-Reflector Stacks on Glass Substrates for MEMS Applications

Thin metal layers such as silver (Ag) are being utilized for various optical and plasmonic applications as well as for electrical purposes, e.g., as transparent electrodes in display devices or solar cells. This paper focuses on optical MEMS applications such as the Fabry–Pérot interferometer (FPI). Within such filters, reflector materials such as distributed Bragg reflectors (DBRs) or subwavelength gratings (SWGs) have been widely used so far, whereas metallic thin films (MTFs) were limited in application due to their comparatively higher absorption. In this paper, thin sputtered Ag layers with thicknesses of 20, 40 and 60 nm on glass substrates have been investigated, and it is shown that the absorption is very low in the visible spectral range (VIS) and increases only in near-infrared (NIR) with increasing wavelength. Thus, we consider Ag-thin layers to be an interesting reflector material at least for the VIS range, which can be easily fabricated and integrated. However, Ag is not inert and stable when exposed to the atmosphere. Hence, it needs a passivation material. For this purpose, AlN has been chosen in this contribution, which can be deposited by sputtering as well. In this contribution, we have chosen thin AlN layers for this purpose, which can also be deposited by sputtering. Thus, various AlN/Ag/AlN-reflector stacks were created and patterned by lift-off technology preferably. The fabricated reflectors were characterized with respect to adhesion, stress, cohesion, homogeneity, and most importantly, their optical properties. It was found that the thickness of the AlN can be used to adjust the reflectance–transmittance ratio in the VIS range, and influences the adsorption in the NIR range as well. Based on the measured values of the reflectors with 40 nm Ag, an exemplary transmission filter characteristics has been predicted for a wavelength range from 400 to 800 nm. Both the maximum transmittance and the full width at half maximum (FWHM) can be tuned by variation of the AlN thickness from 20 to 60 nm.

Solar Spectrum Reflectometer Measurements on Profiled and Small Samples: Design and Testing of Adapters

AbstractTesting solar reflective building materials is mainly performed in laboratories using Solar Spectrum Reflectometer (SSR) or spectrophotometry. To obtain aged materials values, after exposing materials in test farms for natural ageing or applying ASTM-D7897, treated samples shall be tested again using SSR. On-site measurements of new and aged surfaces is allowed using pyranometers or albedometers, which present issues caused both by high-pitched roof and by solar and sky requirements in several locations such as at southern and middle Europe latitudes, where clay tiles are a typical coverage of roof surfaces. The use of battery-powered SSR offsite could be a solution to obtain reliable measurements in every climate, lighting, and slope condition. However, the shape of roof surfaces remains an issue since most of the tiles are characterized by elaborated morphologies that cannot fit the measurement head of the SSR. In this study, two sets of cylindrical adapters for SSR, made via Fused Deposition Modeling and coated with solar reflective white diffuse paint or specular reflective coating were produced and tested to overcome this problem. The adapters were attached to the top of the measurement head and measurements were performed according to ASTM-C1549. These adapters were tested with samples characterized by ASTM-C1549, analyzing the output from all 6 detectors of SSR, and by spectrophotometry according to ASTM-E903, using both AM1GH and ASTM E891-87 irradiance spectra. Aluminum-coated adapters proved ideal due to non-impact on measurements. Solar reflectance showed strong linear correlation for 30–50 mm adapter lengths, indicating minimal signal damping. They will allow testing most of the samples that cannot be tested with standard methods, especially aged ones, without altering their surface.

Performance analysis of hemispherical distiller for different basin materials with mirrors and energy storage material

ABSTRACT A multitude of studies exist on solar desalination systems, particularly focusing on innovative designs for covers and absorber materials to enhance freshwater production. Given the larger exposure area for evaporation and condensation, hemispherical solar stills have become widely utilized. This study primarily centers on improving freshwater yield by incorporating reflective mirrors and absorber materials made of zinc and copper into the hemispherical solar still. The thermal performance is evaluated and compared with a hemispherical solar still lacking these modifications. In addition, sand grains are introduced to the absorber as a means of energy storage. Experimental results demonstrate that the concurrent use of copper as a basin material with reflective mirrors and sand grains as energy storage significantly enhances freshwater production from the hemispherical solar still. The findings reveal an improvement in freshwater yield by up to 156% compared to a conventional hemispherical still. The conventional and modified hemispherical solar stills, with the combined effects of energy storage through sand grains, absorber plate, and reflective mirrors, exhibit a maximum accumulated yield of approximately 4.65 and 11.9 L/m2, respectively. The present findings affirm the importance of the proposed modifications to the hemispherical solar still.

Andragogi: Adaptasi Pembelajaran Orang Dewasa Pada Era Digitalisasi

It is these facilities that can help individuals become more willing to do new things, to be bold and brave, to be able to try new things with new people, and to be willing to share new information that has been learned, making them essential learning environments. Generating a kesalahan is not impossible when learning something new, but the kesalahan and kekeliruan itself are aspects that are understandable in education. Eventually, the old people became disillusioned with their goals and joined a learning group. Those in their later years frequently have the desire to express their kelebihan and kekurangannya. For this reason, it is very important for groups to work together in a comprehensive manner to conduct joint evaluations that can be used as reflective materials. This will enable groups to evaluate each other based on the opinions of other people. The field of education is seeing rapid changes, one of which is the rise of online learning. Digital literacy is declining.