Absence Of Sunlight Research Articles

Thermoradiative Photovoltaics

Devices that operate like solar cells in reverse can generate power even in the absence of sunlight, offering an alternative route for energy production.

Achieving net zero energy penalty in post-combustion carbon capture through solar Energy: Parabolic trough and photovoltaic technologies

The adoption of carbon capture systems presents a pivotal strategy for mitigating greenhouse gas emissions, notably carbon dioxide. Nevertheless, the substantial surge in energy consumption associated with such systems remains a significant challenge. Addressing this challenge necessitates the integration of renewable energy sources. This study is dedicated to optimizing the conventional post-combustion carbon capture configuration, focusing on energy, exergy, and exergoeconomic considerations. The optimized configuration showcases a noteworthy 10 % reduction in overall energy penalties compared to its conventional counterpart, primarily attributed to diminished energy utilization in the reboiler. To achieve absolute sustainability and eliminate energy penalties in the optimized configuration, integration of a parabolic trough collector for steam provision to the reboiler and photovoltaic solar collectors for powering the plant’s equipment was undertaken. Furthermore, the incorporation of solar thermal storage tanks and batteries enables the storage of excess heat and electricity, ensuring operational continuity for up to 13 h in the absence of sunlight, such as during nighttime. The final optimized configuration manifests a commendable 14 % enhancement in exergoeconomic performance relative to the conventional configuration, thereby realizing zero energy penalties. This achievement renders the optimized configuration a compelling and viable choice for carbon capture units.

Permeate gap thermo-osmotic system for simultaneous freshwater production, energy storage, and power generation

The emerging thermo-osmotic system enables harvesting low-grade thermal energy below 100 °C for the simultaneous production of fresh water and electricity. Considering the fluctuation of low-grade heat sources, a novel permeate gap thermo-osmotic system without pump pressurization was proposed in this study, which also allows for energy storage. A lab-scale setup with a 32 cm2 membrane area was built, by which a 2 W light bulb was successfully illuminated through the thermal energy-potential energy-electricity conversion process. In the pressurization process of the permeate side, the hydrophobic membranes with non-woven support exhibit higher pressure resistance, capable of withstanding pressures exceeding 200 kPa. Through experimental and theoretical analyses, the influences of different operation conditions and membrane properties on system performance were studied. Furthermore, utilizing solar energy as the heat source, a case study was conducted based on real meteorological data from a typical coastal city over a consecutive 72-hour period. In the solar-driven PGTO system with a power capacity of approximately 150 kW, the exergy efficiency can achieve 1.04 %, with a power density surpassing 0.1 W m−2, and an average daily freshwater production of over 70000 t. The energy storage function enables stable power generation within the 72 h, and it can sustain steady operation for nearly 7 h thereafter in the absence of sunlight. This study demonstrated the potential of the proposed PGTO system to efficiently utilize fluctuating low-grade thermal energy.

Smart and Intelligent Weather Adaptive Street Lighting System Using IoT

In this paper, an Internet of Things (IoT)- based smart and intelligent weather-adaptive street lighting system containing an Arduino UNO, an ESP 8266, an LDR, a voltage sensor, a current sensor, a PIR, a relay, and a mobile or web application is designed and implemented. This project's primary goal is to create an intelligent and adaptable street lighting system that will guarantee constant lighting for rural residents. This project is to minimize the electricity losses, reduce the manpower used in manually switching on-off the street lights and & energy cost. There are three primary parts to the system: An Arduino NANO, ESP 8266 is a Wi-Fi module for signal transfer and a smart phone that can operate web page servers. These days, consumers are searching for smart systems that require less maintenance and use less energy. This intelligent street light only turns on when needed, and it continues to run on its own subsequent evenings even in the absence of sunlight. Furthermore, an Arduino NANO was used to include a PIR sensor, which detects motion and turns on the lights to bright mode by turning on more lights. Taking those factors into account, these smart streetlights are equipped with an Internet of Things (IoT) powered adaptive system that can detect malfunctions and send message to parent system.

Eco-friendly wearable textiles: Asymmetric structures for EMI shielding, thermal management, and fire safety

This work focuses on developing multifunctional wearable fabrics, specifically targeting the challenge of flammability in this context. An eco-friendly, asymmetrically structured nylon/cotton blend fabric is prepared through the surface modification of phytic acid-induced polyaniline, the application of silver nanowires (AgNWs) and MXene on both sides and encapsulated by polydimethylsiloxane (PDMS). The AgNWs coating suppresses thermal radiation from the human body to achieve radiative heating, while the MXene coating enhances solar heating, ensuring thermal comfort in cold conditions. The treated fabric also exhibits electrical heating for heat compensation in the absence of sunlight, remarkable EMI shielding performance (55.6 dB) is also achieved. Enhanced fire safety is demonstrated as the treated fabric extinguishes when exposed to flame, reducing heat release by 45.9 % relative to the control nylon/cotton blend fabric (CO/NY). Additionally, the treated fabric exhibits significant antibacterial properties against Gram-negative E. coli and Gram-positive S. aureus, along with a notable water contact angle (WCA) of 130.2°. This work provides a promising method for the development of eco-friendly wearable smart fabrics with well-balanced desirable properties.

A multistage assembled laminar membrane for solar thermal conversion and nighttime electricity production

Interfacial solar-driven evaporation technology has great potential to address freshwater shortages. Despite significant progress in developing efficient evaporators, the challenge of evaporation rates of two-dimensional evaporators still needs to be solved. In addition, interfacial solar-driven evaporation relies on solar energy to trigger the evaporation of thin water layers at the water–air interfaces. It thus may be at risk of interruption in the absence of sunlight. To overcome these challenges, we have intelligently assembled different functional components to form a multistage assembled laminar membrane used for interfacial solar-driven evaporation during the day and power generation at night. Specifically, solar evaporation achieved a high evaporation rate of 1.78 kg m−2h−1 under single solar irradiation. Desalination and water purification capabilities were also demonstrated. More notably, the membrane also showed its worth as an electrical generator in overcast weather or nights, delivering a voltage of 309 mV and a current of 2 μA. The voltage and current can be multiplied by connecting four membranes in series and parallel to 1.1 V and 8.8 μA, respectively. This powers a calculator directly and stores excess electricity in a capacitor, which can be as high as 2 V in 2000 s. This innovation shows promising applications in next-generation freshwater production and power generation.

CFD simulation of a solar collector integrated with PCM thermal storage

AbstractThermal energy storage is indeed a valuable solution for addressing the time lag or mismatch between energy supply and demand. The study aims to computationally model the melting and solidification processes of phase change material (PCM) using ANSYS Fluent that utilizes the finite volume technique. The simulations provide insights into the shapes of the liquid fraction, corresponding times, and temperature distribution of the PCM particles under the given conditions. The study considers factors such as solar radiation, thermal conductivity, density, latent heat, and the melting temperature of the PCM. The study finds that paraffin wax melts more quickly under a higher average maximum solar irradiance of 985 W/m2, while a lower solar radiation of 300 W/m2 has the opposite effect. Enhanced heat transfer resulting from conduction within the molten PCM, especially at a thermal conductivity of k = 0.25 W/m·K, accelerates the melting process. The thermal conductivity of the PCM affects the overall performance of the thermal energy storage system. The study highlights the potential application of thermal storage for drying purposes. Through the controlled release of stored heat energy, thermal storage enables the provision of heat in the absence of sunlight.

Arduino Based Sun-Light Detection

This project outlines the development of a sunlight detection system using an Arduino microcontroller. The system utilizes Light-Dependent Resistors (LDRs) to measure sunlight intensity. The Arduino board processes the sensor data and determines the presence or absence of sunlight. This paper provides a concise overview of a project that leverages Arduino's capabilities to detect sunlight. The project uses LDRs, which are inexpensive and readily available sensors that respond to light by changing their resistance. By measuring the LDR's resistance values, the Arduino can gauge the ambient light level and determine if sunlight is present.

Investigation of Solar Energy Applications with Design and Implementation of Photovoltaic Traffic Light Signal System for Qatar

The objective of this paper is to promote the use of solar energy in powering traffic signal systems for rural areas in Qatar with no power grid. A photovoltaic system is needed in order to use this energy continuously. The results of the investigation of components, design, and market availability are shown in the paper. Solar cells, which are used for absorbing sunlight and generating electric current, are the main source for the system’s operation. A charge controller is used to control the flow of charge through the battery and to protect the battery from overcharging and deep discharging. A dc-dc converter is used to regulate the output voltage which depends on the type of dc to dc converter. Lead acid batteries are used as the electric energy storage for the PV system to use electrical energy in the absence of sunlight. The principle operation of the system and the feasibility of using it for rural area with no power grid have been studied. For this project, a mount tracker was constructed that enabled the solar panel to be placed at 0, 15, 30, 45, 60, 75 and 90 degree angles in order to determine which angle and what time provides the optimum voltage. Experimental results for different angles of radiation at different times of the day and different days of the year are shown in the paper.

On-Grid Solar Traction System

World Railways is making significant progress in introducing high-speed trains to fulfil the increasing demands of the traveling public. Massive energy is needed for electric railroads. Many railroads operate their specialized power plants. An energy-storage grid-tied photovoltaic solar plant has been proposed as a strategy to boost the capacity of the rail network grid connection and enable the railway to become self-sufficient. To use the ballast-less rails as energy transporters, The current plan calls for installing solar panels along an HS train network. Ballast-free tracks require very little upkeep, and the space between them provides plenty of surface area for the installation of PV module arrays to harvest solar energy. This generated energy will feed into the main power line by using the concept of an on-grid solar system this energy is not more in numbers to drive the entire traction system, but it helps a lot. From this project we have developed hybrid parallel power sharing for the railway network, under this project the current will be shared in the main power line by matching the grid frequency and voltages. The primary power is solar when it can generate enough electricity. Still, in an abnormal condition, like in the absence of sunlight, the main power continuously feeds electricity without disturbing the traction system.

In situ MIL-101 growth on cotton cloth to fabricate multifunctional phase change composites driven by solar and magneto-thermal for all-day desalination

It is certainly one of the most feasible ways to extract fresh water from seawater in the face of the current depletion of fresh water resources. Although solar energy as a heat source for desalination is the cleanest and most abundant way, its intermittent and seasonal also poses an obstacle to its practical application. In order to solve the above-mentioned issues, we prepared a series of phase change composites (PCCs) with excellent light-absorbing and magnetic properties by growing MIL-101(Fe) in situ on cotton fabric. All-day desalination through the synergistic action of phase change material (PCM) and magnetic particles. The evaporation rate of PCC can reach 2.76 kg m−2h−1 with an evaporation efficiency of 90.19 % under one sunlight condition. The evaporation rate of sea water under the synergistic effect of magnetic particles and PCM reached 4.53 kg m−2h−1 in the absence of sunlight. This paper provides a new approach to all-day desalination without contact heating.

Effects of water turbidity on the survival of Staphylococcus aureus in environmental fresh and brackish waters.

Staphylococcus aureus is an opportunistic pathogen frequently detected in environmental waters, and commonly causes skin infections to water users. S. aureus concentrations in fresh, brackish, and marine waters are positively correlated with water turbidity. To reduce the risk of S. aureus infections from environmental waters, S. aureus survival (stability and multiplication) in turbid waters needs to be investigated. The aim of this study was to measure S. aureus in turbid fresh and brackish water samples and compare the concentrations over time to determine which conditions are associated with enhanced S. aureus survival. Eighteen samples were collected from fresh and brackish water sources from two different sites on the east side of O'ahu, Hawai'i. S. aureus was detected in microcosms for up to 71 days with standard microbial culturing techniques. On average, the greatest environmental concentrations of S. aureus were in high turbidity fresh waters followed by high turbidity brackish waters. Models demonstrate that salinity and turbidity significantly predict environmental S. aureus concentrations. S. aureus persistence over the extent of the experiment was the greatest in high turbidity microcosms with T90 's of 147.8 days in brackish waters, and 80.8 days in freshwaters. This study indicates that saline, turbid waters, in the absence of sunlight, provides suitable conditions for enhanced persistence of S. aureus communities that may increase the risk of exposure in environmental waters.

Multi-operational solar photovoltaic microgrid with synchronization, backup and power quality enhancement ability

The proposed three phase solar photovoltaic microgrid (SPV-MG) works as a multi-mode operational system. It operates under different modes of operations: 1) Daytime, in presence of sunlight, it transfers real power to three-phase loads and grid, also mitigates power quality issues and provides power balance, 2) During grid absence, it operates in standalone mode, gives power backup to local demand and stores excess solar generation into the battery storage (BS). 3) At night, in the absence of sunlight, the SPV-MG has zero power generation so the VSI (Voltage Source Inverter) acts as a Distribution Static Compensator (DSTATCOM). It is capable of providing reactive power compensation, power factor correction (PFC), harmonics elimination, voltage regulation etc. which in turn improves the utilization factor of devices by nearly double-fold. 4) It has re-synchronization and isolation capability with respect to grid availability. A battery storage (BS) is attached at the DC bus of VSI to support the SPV-MG during peak demands and during grid and solar uncertainties. A laboratory prototype is developed to validate the performance with the experimental results.

Photocatalytically reactive surfaces for simultaneous water harvesting and treatment

Atmospheric water harvesting provides decentralized and sustainable supplies of fresh water in areas away from natural water resources. However, an important challenge is that water sources such as fog are subject to contamination from airborne pollutants, especially near population centres. Here we demonstrate a rationally designed system that can capture fog at high efficiency while simultaneously degrading organic pollutants. At the heart of our design is a wire mesh coated with anatase titanium dioxide nanoparticles embedded in a polymer matrix. Once activated by sunlight, the photoactive titanium dioxide layer decomposes organic molecules such as diesel, even in the absence of sunlight; moreover, the wettability of the mesh surface is engineered to enhance water extraction. In outdoor tests, the device can maintain a good fog harvesting performance as well as a water treatment efficiency of >85%. The continuous production of water with passive purification demonstrated in our study provides an energy-free solution to address water scarcity.

New insights into the structure, microbial diversity and ecology of yellow biofilms in a Paleolithic rock art cave (Pindal Cave, Asturias, Spain)

In the absence of sunlight, caves harbor a great diversity of microbial colonies to extensive biofilms with different sizes and colors visible to the naked eye. One of the most widespread and visible types of biofilm are those with yellow hues that can constitute a serious problem for the conservation of cultural heritage in many caves, such as Pindal Cave (Asturias, Spain). This cave, declared a World Heritage Site by UNESCO for its Paleolithic parietal art, shows a high degree of development of yellow biofilms that represents a real threat to the conservation of painted and engraved figures. This study aims to: 1) identify the microbial structures and the most characteristic taxa composing the yellow biofilms, 2) seek the linked microbiome reservoir primarily contributing to their growth; 3) seed light on the driving vectors that contribute to their formation and determine the subsequent proliferation and spatial distribution. To achieve this goal, we used amplicon-based massive sequencing, in combination with other techniques such as microscopy, in situ hybridization and environmental monitoring, to compare the microbial communities of yellow biofilms with those of drip waters, cave sediments and exterior soil. The results revealed microbial structures related to the phylum Actinomycetota and the most characteristic bacteria in yellow biofilms, represented by the genera wb1-P19, Crossiella, Nitrospira, and Arenimonas. Our findings suggest that sediments serve as potential reservoirs and colonization sites for these bacteria that can develop into biofilms under favorable environmental and substrate conditions, with a particular affinity for speleothems and rugged-surfaced rocks found in condensation-prone areas. This study presents an exhaustive study of microbial communities of yellow biofilms in a cave, which could be used as a procedure for the identification of similar biofilms in other caves and to design effective conservation strategies in caves with valuable cultural heritage.

Amyloid-like protein bridged nano-materials and fabrics for preparing rapid and long lasting antibacterial, UV-resistant and personal thermal management textiles

Textiles with efficient and long-lasting antibacterial properties have attracted significant attention. However, a single antibacterial model is insufficient to with variable environments and achieve higher antibacterial activity. In this study, lysozyme was used as assistant and stabilizer, and the efficient peeling and functional modification of molybdenum disulfide nanosheets were realized by ultrasonic. Additionally, lysozyme in the presence of reducing agents to form amyloid-like phase-transited lysozyme (PTL) and self-assembling on the wool fabric. Finally, the AgNPs are reduced in situ by PTL and anchored onto the fabric. It has been demonstrated that Ag-MoS2/PTL@wool generates ROS under light irradiation, rapidly converts photothermal heat into generate hyperthermia, and promotes the release of Ag+. The aforementioned “four-in-one” approach resulted in bactericidal rates of 99.996 % (4.4 log, P < 0.0005) and 99.998 % (4.7 log, P < 0.0005) for S.aureus and E.coli, respectively. Even after 50 washing cycles, the inactivation rates remained at 99.813 % and 99.792 % for E.coli and S.aureus, respectively. In the absence of sunlight, AgNPs and PTL continue to provide continuous antibacterial activity. This work emphasizes the importance of amyloid protein in the synthesis and application of high-performance nanomaterials and provides a new direction for the safe and effective application of multiple synergistic antibacterial modes for microbial inactivation.

0243 SLEEP REGULARITY AND MENTAL HEALTH DURING EXTENDED ANTARCTIC RESIDENCE

Abstract Introduction As humans’ advance towards a Mars mission, ensuring astronaut safety, well-being, and performance becomes increasingly critical. Long-duration space exploration presents several challenges for human sleep, including altered photoperiods, prolonged confinement, and monotony. Antarctica provides an ideal analog for understanding how these and other stressors impact sleep over time. Prior studies among Antarctic cohorts have found reduced total sleep, increased sleep onset, and circadian phase delay. However, day-to-day regularity of sleep-wake patterns in the Antarctic over prolonged periods has not been studied. Methods Crew members (N= 110) at a coastal (McMurdo: MM, n = 88) and an inland Antarctic station (South Pole: SP, n = 22) were studied longitudinally for up to 9-months. Sleep was monitored continuously with actigraphy (Actiwatch Spectrum, Philips Respironics) and examined in relation to cumulative time on station and calendar month (photoperiod). Self-reported mental health symptoms were also examined monthly using The Mental Health Checklist (MHCL). The Sleep Regularity Index (SRI; Phillips et al., 2017) which calculates the percentage probability of an individual being in the same state (sleep vs. wake) at any two time-points 24 hours apart was calculated to examine sleep regularity over time. Results Controlling for time on station prior to participation, we observed no significant changes in monthly SRI over a 6-month period at MM where photoperiod alterations are less extreme. At SP, SRI remained very stable during months of total daylight but declined during winter months in the absence of sunlight. SRI scores were significantly different between month-8 and month-9 and with large effect sizes across month-7, month-8, and month-9. Participants with lower month-7 SRI scores had significantly higher MHCL poor self-regulation scores at the end of the mission. Conclusion Day-to-day variability in sleep–wake patterns is an important predictor of health and safety. Our findings show reductions in sleep regularity during prolonged Antarctic residence particularly at the SP station, where sunlight is absent for 6 months of the year. Less sleep regularity predicted worse mental health functioning. These findings suggest that mitigation the impact of altered light-dark cycles on sleep is critical for a Mars mission. Support (if any) NASA award #NNX15AC13G S014 to the last author.

Population structure of an Antarctic aquatic cyanobacterium

BackgroundAce Lake is a marine-derived, stratified lake in the Vestfold Hills of East Antarctica with an upper oxic and lower anoxic zone. Cyanobacteria are known to reside throughout the water column. A Synechococcus-like species becomes the most abundant member in the upper sunlit waters during summer while persisting annually even in the absence of sunlight and at depth in the anoxic zone. Here, we analysed ~ 300 Gb of Ace Lake metagenome data including 59 Synechococcus-like metagenome-assembled genomes (MAGs) to determine depth-related variation in cyanobacterial population structure. Metagenome data were also analysed to investigate viruses associated with this cyanobacterium and the host’s capacity to defend against or evade viruses.ResultsA single Synechococcus-like species was found to exist in Ace Lake, Candidatus Regnicoccus frigidus sp. nov., consisting of one phylotype more abundant in the oxic zone and a second phylotype prevalent in the oxic-anoxic interface and surrounding depths. An important aspect of genomic variation pertained to nitrogen utilisation, with the capacity to perform cyanide assimilation and asparagine synthesis reflecting the depth distribution of available sources of nitrogen. Both specialist (host specific) and generalist (broad host range) viruses were identified with a predicted ability to infect Ca. Regnicoccus frigidus. Host-virus interactions were characterised by a depth-dependent distribution of virus type (e.g. highest abundance of specialist viruses in the oxic zone) and host phylotype capacity to defend against (e.g. restriction-modification, retron and BREX systems) and evade viruses (cell surface proteins and cell wall biosynthesis and modification enzymes).ConclusionIn Ace Lake, specific environmental factors such as the seasonal availability of sunlight affects microbial abundances and the associated processes that the microbial community performs. Here, we find that the population structure for Ca. Regnicoccus frigidus has evolved differently to the other dominant phototroph in the lake, Candidatus Chlorobium antarcticum. The geography (i.e. Antarctica), limnology (e.g. stratification) and abiotic (e.g. sunlight) and biotic (e.g. microbial interactions) factors determine the types of niches that develop in the lake. While the lake community has become increasingly well studied, metagenome-based studies are revealing that niche adaptation can take many paths; these paths need to be determined in order to make reasonable predictions about the consequences of future ecosystem perturbations.2GZ5fuYNnhGp9HukxerBaXVideo

Design and building of a battery charging system using hybrid solar tracker and electric trip based on FPAO-FLC

&lt;p&gt;The proposed system is a hybrid charging system between a solar tracker and an electric grid using two converter types. The photovoltaic (PV)-based solar tracker has powerful tools, but its weakness is when the absence of sunlight. With a combination of two resources, the weakness can overcome. The control so good is needed so that it can overcome those weaknesses too. This study uses the flower pollination algorithm optimization-fuzzy logic controller (FPAO-FLC). Results of control using FPAO-FLC has a value of a rising time of 0.0123 seconds, settling time of 2.1099 seconds, maximum overshoot of 6.08%, a peak time of 0.9246 seconds, and steady-state error of 3.43%. The efficiency of the ZETA converter using FPAO-FLC control in the tracking condition PV compared to the fixed condition has increased 43, 24%, and the state of charge (SOC) of the battery reaches 39.08%. The advantage of this hybrid system is that it has two modes of operation, which are automatic, including simultaneous and individual operating modes. The data collection results show that the energy obtained by the individual grid mode dan the individually solar tracker mode is 92.62 Wh and 310.38 Wh. The total energy obtained was 479.81 Wh.&lt;/p&gt;

Multifunctional Photothermal Phase-Change Superhydrophobic Film with Excellent Light-Thermal Conversion and Thermal-Energy Storage Capability for Anti-icing/De-icing Applications.

The accumulation of ice may cause serious safety problems in numerous fields. A photothermal superhydrophobic surface is considered to be useful for preventing ice formation because of its environmentally friendly, energy-saving, and excellent anti-icing/de-icing properties. However, it easily fails to work in the absence of sunlight. To improve its anti-icing property without sunlight irradiation, a multifunctional photothermal phase-change superhydrophobic film (MPPSF) consisting of phase-change microcapsules (PCMs) and carbon nanotubes (CNTs) was fabricated using a facile spraying method. Benefitting from the excellent light-thermal conversion effect of CNTs, the surface temperature could increase from -20 to 130.1 °C within 180 s under 808 nm near-infrared laser irradiation of 1 W/cm2, thus realizing high-efficiency de-icing. Meanwhile, a portion of the light-thermal energy was stored in the MPPSF because of the phase change of the PCMs. Without sunlight irradiation, the latent heat of the PCMs was released when the external temperature approached the phase-transition temperature. The synergistic effects of the phase-transition latent heat release and superhydrophobicity allowed the MPPSF to effectively hinder the formation of ice for 10.1 min at -20 °C. Therefore, this MPPSF with outstanding anti-icing and de-icing performances is expected to achieve ice prevention and removal in all-days.