Collection Efficiency Research Articles

Circular Bragg grating single-photon source design exploiting extreme dielectric confinement

Abstract We theoretically propose a single-photon source design based on a circular Bragg grating microcavity incorporating two air triangles in a bowtie configuration. Our proposed design allows for extreme light confinement with a Purcell factor of approximately 166 with a bandwidth of ~9 nm for a triangle separation of 5 nm combined with a collection efficiency above 80 % . The Purcell factor is enhanced by a factor of 8 relative to the reference cavity thanks to the reduction of the mode volume. Furthermore, we demonstrate the critical role of the dipole emitter polarization orientation and spatial position in achieving optimal Purcell enhancement.

Efficient Fog-Harvesting Origami Fan.

Fog harvesting represents a promising strategy to address the global freshwater shortage. To enhance the water collection efficiency, diverse geometric structures that can effectively drive water droplet movement are essential. Inspired by the Livistona chinensis leaf, which naturally facilitates directional droplet motion through its unique gradually varying V-groove structure, we have developed a novel origami fan structure for fog harvesting through theoretical analysis. A key feature is that we can modulate the speed of droplet transport by adjusting the opening angle of the V-shaped grooves positioned at the outer circumference. Interestingly, the water collection efficiency exhibits a linear correlation with the opening angle. The highest efficiency of the origami fan can reach 5.75 times that of the control group calculated by the projected area and 3.76 times that of the control group calculated by the real area, showcasing its significant potential for enhancing water collection from fog. The simulations demonstrate that the hollow structure enhances the condensation rate of droplets, the geometric gradient of the gradual-variation V-groove drives the condensed droplets to move rapidly on the surface, and the Janus membrane permits the aggregated droplets to transit to the fan's rear side. The synergistic action of these three components ensures a clean surface for the subsequent water-collecting cycle, contributing to the high fog-harvesting efficiency. Given its simple fabrication and superior water transfer efficiency, the origami fan holds substantial promise for widespread application in the field of droplet manipulation.

Intercalation Electrode and Grain Reconstruction Induce Significant Sensitivity Enhancement for Perovskite X-ray Detectors.

Organic-inorganic hybrid perovskites have been recognized as potential candidates in direct X-ray detectors and have triggered tremendous interest in the past years. The blade coating method meets the requirements of large area and low cost for perovskite X-ray detectors, while the low compactness resulting from solvent evaporation limits the charge collection efficiency (CCE) and device sensitivity. Most of the reports are focused on the melioration of perovskite films to increase device sensitivity; there are still problems of low CCE. Herein, we introduce an intercalation-electrode device structure and achieve a ∼20-fold sensitivity enhancement. Carrier distribution throughout the thick films is simulated, and the electrode intercalating site can be optimized according to the mobility-lifetime factor to achieve the highest CCE. A methylamine thiocyanate (MASCN) additive-assisted coating strategy is developed, and pinhole free thick films with regrown particles are obtained without frequently used hot/soft pressing. A sensitivity level of ∼105 μC Gyair-1 cm-2 as well as a detection limit of 77 nGyair s-1 is achieved under low bias, which is among the best performance for polycrystalline perovskite direct X-ray detectors. This work provides a universal device structure design to overcome carrier loss through a long transport distance and enhances the CCE for ultrahigh sensitivity.

Collective and Individual Self-Regulation Processes During a Project-Based Learning Process

In higher education, students are faced with group tasks, such as project-based learning. However, research on self-regulated learning has paid little attention to the details of collective self-regulation. In this framework, the objective of this research was to determine the impact of the feeling of collective efficacy on the performance of groups of students involved in self-regulation processes in project-based learning. The quantitative approach was adopted. The type of descriptive research and field design. The 45 volunteer participants of an education program at the National University of the Altiplano completed a questionnaire that explored different aspects of self-regulation: Use of human resources, setting objectives, collective efficacy, expression of disagreements, and quality of interactions. The questionnaire comprised 20 items rated on a Likert-type scale, ranging from 1 (strongly disagree) to 6 (strongly agree), and included two open-ended questions aimed at understanding strategies for managing doubts and maintaining interest int the project. The results show that the feeling of collective efficiency is a significant predictor of the final grade in the project and that the group’s ability to define the objectives precisely and prioritize them contributes significantly to the development of the feeling of collective efficacy. The conclusion exposes the pedagogical implications of these results, emphasizing the essential role of tutors in fostering an environment conducive to collective efficacy by guiding students in defining, prioritizing objectives, and managing doubts effectively. This guidance is crucial, especially in the early phases of project implementation, to establish a dynamic of collective efficacy and develop individual interest in the project.

A Collection of Components to Design Clinical Dashboards Incorporating Patient-Reported Outcome Measures: Qualitative Study.

A clinical dashboard is a data-driven clinical decision support tool visualizing multiple key performance indicators in a single report while minimizing time and effort for data gathering. Studies have shown that including patient-reported outcome measures (PROMs) in clinical dashboards supports the clinician's understanding of how treatments impact patients' health status, helps identify changes in health-related quality of life at an early stage, and strengthens patient-physician communication. This study aims to determine design components for clinical dashboards incorporating PROMs to inform software producers and users (ie, physicians). We conducted interviews with software producers and users to test preselected design components. Furthermore, the interviews allowed us to derive additional components that are not outlined in existing literature. Finally, we used inductive and deductive coding to derive a guide on which design components need to be considered when building a clinical dashboard incorporating PROMs. A total of 25 design components were identified, of which 16 were already surfaced during the literature search. Furthermore, 9 additional components were derived inductively during our interviews. The design components are clustered in a generic dashboard, PROM-related, adjacent information, and requirements for adoption components. Both software producers and users agreed on the primary purpose of a clinical dashboard incorporating PROMs to enhance patient communication in outpatient settings. Dashboard benefits include enhanced data visualization and improved workflow efficiency, while interoperability and data collection were named as adoption challenges. Consistency in dashboard design components is preferred across different episodes of care, with adaptations only for disease-specific PROMs. Clinical dashboards have the potential to facilitate informed treatment decisions if certain design components are followed. This study establishes a comprehensive framework of design components to guide the development of effective clinical dashboards incorporating PROMs in health care practice.

Experimental and Numerical Investigation of Slip Effect on Nanofiber Filter Performance at Low Pressures.

Nanofiber filters are widely used in air filtration applications due to their superior performance over microfiber filters. Velocity slip around nanofibers has been identified as a key factor contributing to their high figure of merit, yet its impact on filter performance, especially particle collection efficiency, remains unclear due to the difficulty in isolating the slip effect as the sole variable. This study combines experimental and simulation methods to investigate the slip effect by adjusting the air molecule mean free path, rather than varying fiber size as done in previous studies. Filter media with mean fiber sizes ranging from 16.2 to 0.084µm are utilized. An image-based regression method is developed to address the challenge of determining the solidity of thin nanofiber layers. The results show that the slip effect is enhanced as the testing pressure decreases, reducing pressure drop by less than 15% for microfiber filters and over 50% for nanofiber filters ≈100nm. The enhanced slip effect at low pressures (i.e., relatively low pressure compared to the ambient environment) significantly improves filtration efficiency, especially for particles larger than 100nm. It also proposes semi-empirical equations for predicting filter performance in slip and transition flow regimes.

Comparative analysis of the effectiveness and efficiency of formal and informal waste collectors in urban waste management system

Effective and efficient waste collection and management is critical to achieving sustainable cities and communities, public health, and sustainable development. This notwithstanding, the rapid and ever-increasing rate of urban waste generation in developing countries has led to the emergence of a dual system of formal and informal waste collection schemes with unclear effectiveness and efficiency. This study compared the operational effectiveness and efficiency of formal and informal waste collectors in the urban waste management system in Ghana. A case study research design is employed with a focus on households and waste collectors in the Suame Municipality in the Ashanti of Ghana. Data were collected through questionnaire administration and interviews, waste quantification, and field measurements. The findings reveal that 61.5 % of households rely on informal waste collectors, 35 % on formal waste collectors and 3.5 % use indiscriminate dumping. The formal waste collectors were more effective serving 111 households and collecting 11.239 tonnes of waste per trip but utilises 62 % of their collection capacity while the informal sector collects 846.67 kg per trip and uses 106 % of their collection capacity. Formal waste collectors were also more efficient with the use of time. The study unveils an opportunity to enhance effectiveness and efficiency in municipal waste management in low- and middle-income countries with reforms and practices that build upon existing waste management practices and integrate informal waste collectors into formal waste management systems.

Performance evaluation of cyclone models for similar body diameter and flowrate using CFD

Abstract The present study performs numerical simulations of a few popular medium-to-high efficiency cyclone models viz. Stairmand cyclone, Swift cyclone, Patterson-Munz cyclone, Obermair cyclone, and Lapple cyclone to compare their performance. The reason to undertake this study is that these models are widely used for benchmark studies or for the validation by the researchers. Earlier, all these geometries were investigated experimentally by respective inventors that bear different sizes. Hence, for the sake of performance comparison, the diameter (D = 0.29 m) and a volume flow rate (Q = 0.135401 m3/s) of the fluid in all the models is the same - the latter is used to calculate the inlet velocity in each cyclone model. We have not considered a similar Reynolds number condition for comparison as it will change the volume flow rate of the flow. Apart from the pressure drop and collection efficiency values, we present the details of the flow field inside each model. Conclusive results indicate that the Patterson-Munz cyclone has the lowest pressure drop while the Swift cyclone has the highest collection efficiency. Interestingly, the cut-off diameter in the swift cyclone is found to be minimum.

Enhancing Laboratory Sample Collection Efficiency through Laboratory Information Systems: Insights into Optimal Despatch Rider Management

Effective administration of dispatch riders is crucial for delivering reliable diagnoses and research results by enabling prompt and precise sample collection. Laboratory Information Systems (LIS) offers a solution to enhance the efficiency and organization of dispatch riders in laboratory settings. Thus, the main objective of this study is to provide insights and knowledge on the potential benefits of implementing LIS to optimize the management of dispatch riders and enhance the efficiency of sample collection. An analysis of previous research findings illustrates the varied benefits of using LIS in improving key performance indicators such as turnaround time, mistake rates, and coordination of dispatch riders. The LIS platform serves as a centralized system for managing and allocating sample collection jobs, minimizing scheduling conflicts, and optimizing dispatch rider routes. Real-time tracking capabilities enable laboratory management to monitor dispatch rider locations and sample collection progress, facilitating enhanced coordination and resource allocation. Furthermore, LIS-generated data analytics provide valuable insights into sample collection patterns, enabling proactive management strategies to mitigate potential bottlenecks. Integration of LIS into payroll systems allows for automated compensation calculation based on dispatch rider performance metrics, ensuring fair and transparent pay rates. Studies consistently demonstrate that adequate compensation positively impacts dispatch rider motivation and sample collection effectiveness. This study highlights the vital importance of LIS in enhancing dispatch rider administration for efficient sample collection operations. It provides insights for laboratory managers and policymakers to optimize the potential of LIS to improve operational performance, facilitate patient care, and advance research outcomes.

Active learning for efficient data selection in radio‐signal‐based positioning via deep learning

AbstractThe problem of user equipment positioning based on radio signals is considered via deep learning. As in most supervised‐learning tasks, a critical aspect is the availability of a relevant dataset to train a model. However, in a cellular network, the data‐collection step may induce a high communication overhead. As a result, to reduce the required size of the dataset, it may be interesting to carefully choose the positions to be labelled and to be used in the training. Therefore, an active learning approach for efficient data collection is proposed. It is first shown that significant gains (both in terms of positioning accuracy and size of the required dataset) can be obtained for the considered positioning problem using a genie. This validates the interest of active learning for positioning. Then, a practical method is proposed to approximate this genie.

Temperature-induced phase transition of liquid metal for shape-adaptive triboelectric nanogenerator

Flexible wearable electronics are expected to fit different parts of the human body. However, existing energy harvester and sensor still face the difficulties of adhering to complex surfaces and spontaneously fixing to the human body. In this work, a shape-adaptive triboelectric nanogenerator (SA-TENG) based on the phase transition of liquid metal (Cd-In-Sn-Pb-Bi eutectic alloy, LM) has been constructed to achieve efficient wearable energy collection and sensitivity-tunable pressure sensing. The shape-adaptive energy harvester (SA-EH) prepared by constructing hole arrays on the electrode could be directly fixed on different parts of the human body to harvest mechanical energy for driving wearable electronics. It can generate a transferred charge density of 90.5 μC/m2 and an average power density of 45.1 mW/m2. The natural oxide layer of LM suppresses the loss of liquid electrode and increases the output by 18 % with charge trapping-blocking effect. Furthermore, a sensitivity-tunable pressure sensor (ST-PS) fabricated with microstructures on the surface of SA-TENG can realize the sensitivity of over 2.48 kPa−1 as well as the ultra-wide pressure detection range from 0.42 kPa to 113.17 kPa, and the LM-based shielding layer can weaken external interference. This novel electrode design has greatly expanded the applications of TENGs in wearable electronics.

Tax Morale, Governance Quality And Tax Compliance

This study aims to investigate the relationship between tax morale, governance quality, and tax compliance in Nigeria. The study used the library research approach, which involved examining books, academic journals, and conference papers. According to the evaluation, tax compliance in Nigeria remains below standard, resulting in low tax morale, which is influenced by people's perceptions of government services, a lack of justice, and trust. The study also discovers that tax morale has a significant impact on tax noncompliance, such as a decrease in foreign portfolio equity investment inflows for tax avoidance, self-employed tax payers, and perceptions of higher tax fines and difficulty evading taxes. The study also discovers a favourable link between government quality (excellent governance, views of government accountability and provisions) and tax compliance. Studies have shown a considerable association between tax morale, governance quality, and tax compliance. The study recommends that government put in place efficient and effective tax collection policies, through providing people with accessible ways of paying their taxes, simplifying the process and reduction of taxes imposed on lower income individuals.

دراسة عملية لاداء سخان ماء شمسي ذو الدوران الطبيعي المتصل على التوالي

This research paper presents an experimental study on the performance of a natural circulation solar water heater system with two typical collectors connected in series. The paper provides a comprehensive analysis of the system's thermal performance under different load conditions, including no-load, intermittent, and continuous load. Mean storage tank, solar collector means plate (the left) temperature and thermosyphon flow rate in a vertical tank were measured. Results showed that there was variation in solar water tank and collector plate temperature under load and no-load conditions. Analysis of thermal performance of the system was conducted for each condition. The highest plate temperature (100 ˚C or even more) with no circulation of both collector and load conditions, indicate the high quality of the solar collectors even during the cold season. The collector’s arrangement in series connection is of highest gain in energy and higher storage tank mean water temperature. Several characteristic equations obtained to represent the performance of the present natural circulation system under collector connection arrangement in series. In fact, when large amount of hot water was required for a certain purpose (Industrial sector for example - MSF plant or central heating), multiple collectors are to be deployed in series and in parallel to produce the required amount (quantity) and desired temperature (quality) at the same time. Key words: Thermosyphon solar water heater, storage tank profile temperature, Solar Water Heaters (SWHs), instantaneous efficiency, collector flow factor, collector efficiency factor, collector heat removal factor

Analysis of Implication of Phase Change Material Enclosed Design on Thermal Performance of Solar Collector

Abstract The energy, which is converted from the sun rays, was called solar energy. This is very essential renewable energy converting methods that had a higher influence for water distilling system. Here, the implication of the Phase Change Materials (PCM) in that exit was analyzed. This energy from the sun is trapped in paraffin wax for the storing system whiles the greater radioactive effect. This trapped heat power than utilized for increase the fluid temperature during the lesser radioactive times. Here, the Implication of the heat storing units on the exit temperature was analyzed. Furthermore, Thermal solar collector was analyzed for the following years 2021 and 2022. The Concentric PC is placed over the top of the collector of the solar rays. And then, a paraffin wax layer was placed under the solar absorber plate like the back-up to store the LH Energy. The uniform rate of flow was produced a greater exit temperature of water the two years. The efficiency rate increased 11–14% and the collected energy gain rate enhanced 18–19%. The peak water temperature was 61°C & 60°C for the 2 consecutive years for Paraffin wax integrated solar collecting unit. At the same time the efficiency of heat energy is peak at 49% in January 2022. The solar collector efficiency primarily relies on the design and construction of collector itself.

Modelling of Control Strategy for Sun Tracking of Concentrated Photovoltaic (CPV) Systems and Performance Analysis of Optical Losses Due to Tracking Errors.

Abstract Among the wide range of solar energy technologies, CPV remains a promising technology worldwide. The photovoltaic concentrator maximizes its efficiency through the use of optical concentration systems. But since optical concentration depends on direct solar radiation, maximizing the quantity of useful solar radiation received requires using a solar tracker that tracks the direction of the sun. To maximize collector efficiency, it’s crucial to choose tracking systems that align with the optical concentration factor. Inadequate focusing of direct solar radiation on the concentrator’s receiver can result in high optical losses, regardless of quality. This paper focuses on improving the accuracy and lowering the cost of the tracker trajectory generation strategy. A sun tracker simulator is first developed, allowing for the investigation of the impact of sun tracking performance a traditional control strategy is initially implemented that uses an astronomical calculation to follow the path of the sun. This strategy uses a sun position algorithm from the National Renewable Energy Laboratory to generate the tracker trajectory and track the sun’s path. When tested on the simulator, as a result, this strategy demonstrated a level of accuracy that ensured a good balance between intricacy and accuracy. Then, An investigation study was conducted to determine how this solar tracker’s precision might affect its optical efficiency. the optical losses resulting from the tracking were calculated using the provided location, The optical loss calculated for this collector’s maximum tracking error is approximately 9%. The research methodology showed that the tracker precision satisfied the requirements of the optical system under study.

Constructing Multiscale Fibrous Morphology to Achieve 20% Efficiency Organic Solar Cells by Mixing High and Low Molecular Weight D18.

This study underscores the significance of precisely manipulating the morphology of the active layer in organic solar cells (OSCs). By blending polymer donors of D18 with varying molecular weights, a multiscale interpenetrating fiber network structure within the active layer is successfully created. The introduction of 10% low molecular weight D18 (LW-D18) into high molecular weight D18 (HW-D18) produces MIX-D18, which exhibits an extended exciton diffusion distance and orderly molecular stacking. Devices utilizing MIX-D18 demonstrate superior electron and hole transport, improves exciton dissociation, enhances charge collection efficiency, and reduces trap-assisted recombination compared to the other two materials. Through the use of the nonfullerene acceptor L8-BO, a remarkable power conversion efficiency (PCE) of 20.0% is achieved. This methodology, which integrates the favorable attributes of high and low molecular weight polymers, opens a new avenue for enhancing the performance of OSCs.

Detector upgrade for 222Rn concentration in high purity nitrogen measurement

To ensure the low background of the Jiangmen Underground Neutrino Observatory (JUNO) detector, high purity nitrogen (HPN) is used as a cover gas in direct contact with the liquid scintillator, which serves as the target material for neutrinos. The radon concentration in this nitrogen should be less than 10 μBq/m3. Given the background of the old detector, which is 2.20 ± 0.64 mBq/m3, combined with its enrichment efficiency of 51.0 % at a flow rate of 25 standard liters per minute (SLM), the effective measurement of radon concentrations below 10 μBq/m3 in HPN is a major challenge. A highly sensitive radon detector was upgraded to measure the radon concentration in HPN. A low background radon detection chamber was constructed based on the method of electrostatic collection and electrolytic polishing of low background steel with an internal surface roughness of ≤ 0.2 μm. The background of the radon detection chamber was reduced to 1.47 ± 0.19 mBq/m3. An automatic enrichment system based on 472 g low background activated carbon was developed. The introduction of a large amount of activated carbon has led to a significant increase in the enrichment flow rate to 200 SLM. In addition, the enrichment efficiency of the system simultaneously improved to 71 %. The relationship between the collection efficiency of the detection chamber and the applied voltage was calibrated. The result measured with this detector, shows that the radon concentration in HPN is 2.38 ± 0.30 μBq/m3.

Unlocking OER potential: Tailoring layered double perovskites through self-reconstruction

The sluggish rate of the anode oxygen evolution reaction (OER) is a major bottleneck for green hydrogen production, making a room-temperature alkaline water electrolyser critical to unlocking the full potential of this technology. Using a perovskite oxide as an electrochemical matrix and forming a self-assembled oxyhydroxide (OOH) layer on the surface via a self-reconstruction activation process (SRAP) is a promising strategy to enhance OER catalytic activity. However, the mechanistic details and long-term impact of SRAP, especially its relationship to catalytic activity, oxygen collection efficiency, and catalyst dissolution, are not fully understood. To address this knowledge gap, we used layered double perovskite (LDP) PrBa0·75Ca0·25Co1·5Fe0·5O5+δ(PBCCF) and PrBa0·75Ca0·25Co1·5Fe0·4Ni0·1O5+δ (PBCCFN) as model electrochemical catalysts and then triggered SRAP. Subsequently, chronoamperometry (CA), rotating ring disk electrode (RRDE) and in-situ electrochemical quartz crystal microbalance (EQCM) were used to study the effect of the Ni-doping on PBCCF SRAP in terms of catalytic activity, oxygen collection efficiency and catalyst stability. The results showed that the OER catalytic current of the LDP PBCCF and PBCCFN was enhanced via SRAP and the oxygen collection efficiency can be maintained, suggesting that the increase in catalytic current is attributed to OER catalytic activity increase rather than electrochemical catalyst dissolution. Additionally, the effect of the catalytic activity enhancement was more significant in PBCCFN. More importantly, the stability of the LDP PBCCF and PBCCFN after SRAP are higher than simple perovskite Ba0·5Sr0·5Co0·8Fe0·2O3-δ (BSCF) because of the increase in the redeposition rate. The observations suggest that using LDP PBCCF and PBCCFN as matrices followed by triggering SRAP can provide valuable insights for designing LDP based OER electrocatalysts.

Beam energy recovery in Neutral Beam Injections and related simulations

The Neutral Beam Injectors (NBI) will be used to further increase the plasma temperature for the ignition of the fusion reactions in the ITER project. For future applications of electric energy production, the NBI efficiency is crucial. Since the gas neutralizer gives large residual ion fractions of D+ and D-, adequate energy recovery systems may be necessary. Recently a conceptually simple beam energy recovery based on space charge effects has been proposed; it can also work as an ion dump device, with advantages in removing the residual ions with reduced power dissipation. Preliminary simulation results were evidence of that the proposed device can remove all the residual ions by collecting them at very low energy on proper electrodes. In this contribution, further simulations with more accurate space charge calculations are reported to mostly confirm the high residual ion collection efficiency obtained in the preliminary simulations. The simulated operation voltage is also increased from 20 kV to 500 kV in steps. Higher efficiencies require some increase of the collector length, especially at higher operation voltage, as here discussed. Some design detailed features are also updated.

Mapping PM2.5 Sources and Emission Management Options for Bishkek, Kyrgyzstan

Harsh winters, aging infrastructure, and the demand for modern amenities are major factors contributing to the deteriorating air quality in Bishkek. The city meets its winter heating energy needs through coal combustion at the central heating plant, heat-only boilers, and in situ heating equipment, while diesel and petrol fuel its transportation. Additional pollution sources include 30 km2 of industrial area, 16 large open combustion brick kilns, a vehicle fleet with an average age of more than 10 years, 7.5 km2 of quarries, and a landfill. The annual PM2.5 emission load for the airshed is approximately 5500 tons, resulting in an annual average concentration of 48 μg/m3. Wintertime daily averages range from 200 to 300 μg/m3. The meteorological and pollution modeling was conducted using a WRF–CAMx system to evaluate PM2.5 source contributions and to support scenario analysis. Proposed emissions management policies include shifting to clean fuels like gas and electricity for heating, restricting secondhand vehicle imports while promoting newer standard vehicles, enhancing public transport with newer buses, doubling waste collection efficiency, improving landfill management, encouraging greening, and maintaining road infrastructure to control dust emissions. Implementing these measures is expected to reduce PM2.5 levels by 50–70% in the mid- to long-term. A comprehensive plan for Bishkek should expand the ambient monitoring network with reference-grade and low-cost sensors to track air quality management progress and enhance public awareness.