Search Results (891)

Quantum cascade lasers (QCLs) have emerged as promising candidate sources for free-space communications. High optical power densities, short photon lifetimes, and low internal capacitance are important factors influencing the transmission bandwidth. We report the design and fabrication of 4.7 μm emitting, 1.5 mm cavity length, single-mode distributed-feedback QCLs, with a CW front-facet output power of 165 mW and a calculated photon lifetime of 11.6 ps, resulting in an electrically limited CW modulation with a 3 dB cutoff at 850 MHz. Full article

The microwave polarization index (PI), defined as the difference between vertically polarized (V-pol) and horizontally polarized (H-pol) brightness temperature divided by their average, is independent of land surface temperature. Since soil emission is stronger at V-pol than H-pol and vegetation attenuates this polarized soil signal primarily because of liquid water stored in vegetation tissue, a lower PI will be indicative of more water in vegetation if vegetation emits a mostly unpolarized signal and changes in soil moisture within the emitting depth are small (like during periods of drought) or accommodated by averaging over long periods. We hypothesize that the L-band PI will reveal diurnal changes in vegetation water related to whether plants have adequate soil water. We compare 6 a.m. and 6 p.m. L-band PI from NASA’s Soil Moisture Active Passive (SMAP) satellite to the evaporative stress index (ESI) in the U.S. Corn Belt during the growing season. When ESI<0 (there is not adequate plant-available water, also called plant water stress), the L-band PI is not significantly different at 6 a.m. vs. 6 p.m. On the other hand, when ESI≥0 (no plant water stress), the L-band PI is greater in the evening than in the morning. This diurnal behavior can be explained by transpiration outpacing root water uptake during daylight hours (resulting in a decrease in vegetation water from 6 a.m. to 6 p.m.) and continued root water uptake overnight (that recharges vegetation water) only when plants have adequate soil water. Consequently, it may be possible to use L-band PI to identify plant water stress in the Corn Belt. Full article

Vertical addition to already-existing structures is an approach to energy-efficient building renovation. It presents an opportunity for the densification of built-up areas and the construction of new usable spaces. While many studies have dealt with the subject of renovating buildings with a focus on energy efficiency, far fewer studies have specifically examined the potential of vertically extending existing buildings, an approach which could be introduced in new sustainable building policies. The objective of this study is to redevelop optimal timber–glass upgrade modules, considering the ideal proportions of glazing for all cardinal directions, by using discrete Mixed-Integer Non-Linear Programming optimization. The novelty of the suggested method resides in the synchronous optimization of the upgrade modules’ daylighting and energy-efficiency performance, resulting in the creation of optimization methods that can determine the optimal glazing proportions for all cardinal directions and incorporate rational design and window measurement. The impact of the developed Mixed-Integer Non-Linear Programming-optimized upgrade modules is compared to previously designed optimized upgrade modules. Finally, a methodology for estimating the energy efficiency of building renovations incorporating vertical additions using the timber–glass upgrade modules was developed, supporting the quick assessment of the reduction in hybrid buildings’ energy consumption for heating and cooling according to boundary conditions, presuming that they undergo the suggested renovations. The findings are applicable (not exclusively) to Slovenia’s residential building stock, which makes up around 20% of the country’s current housing stock and was mainly constructed between 1946 and 1970. This offers a substantial opportunity to improve the overall sustainability and energy efficiency of the country’s housing stock. The proposed approach offers a holistic solution to drive sustainable development in the built environment by incorporating all three pillars of sustainability (environmental, social, and economic). Full article

Building optimisation techniques provide a rigorous framework for exploring new optimal design solutions. In this study, a genetic algorithm (GA) was used to investigate the energy efficiency of a vernacular architectural element (Rawshan) in Saudi Arabia. Two objectives were optimised using a GA simulation enhanced: energy consumption optimisation and useful daylight illuminance (UDI) optimisation. A calibrated simulation model of a typical house in Saudi Arabia was used in the study. Several metrics, such as light interference from shadows or other windows, were considered to indicate the importance of the Rawshan. Computational studies were performed using different climatic conditions, and the results were compared with and without a Rawshan element using the weather data of Mecca, Jeddah, Riyadh, and Al-Baha. In this study, the blind thicknesses on the front and sides of the Rawshan were used as optimisation variables. The results showed that using a GA with energy consumption as an objective can reduce energy consumption. One of the methods proposed in the paper can reduce energy consumption by 3.6%, 3.6%, and 16.6% for Mecca, Riyadh, and Al-Baha, respectively. The single-objective optimisation method demonstrated that Rawshan provided sufficient UDI in four cities: Mecca, Jeddah, Riyadh, and Al-Baha. The research provided optimised values for Rawshan blind thicknesses on the front and lateral sides under different optimisation constraints. The results showed that using Rawshans in modern building architecture can reduce energy consumption and improve useful daylight illuminance. Full article

In today’s society, stress is recognized as a major contributor to illness. It can be reduced through exercise, which lowers stress hormones, and exposure to daylight, which regulates hormones such as cortisol and melatonin. Furthermore, the design and perception of the environment can indicate danger or safety, influencing stress levels and mental health. This study examines the Tehran Oil Refinery’s impact on local residents’ perceptions of landscape values and mental health. Oil refineries, which use compounds derived from natural gas or crude oil, pose both short- and long-term environmental and health risks. Using a Geographic Information System for Public Participation (PPGIS), the study investigates how the industrial landscape surrounding the Tehran Oil Refinery influences residents’ emotional responses and stress levels. The study collects sociodemographic data, self-perceived health data, and landscape valuations before and after photography interventions. The findings indicate a complex relationship between the refinery’s presence and perceptions of landscape values. Manipulated photographs used in the study show how visual elements can influence emotional responses, highlighting a direct link between stress and environmental perception. This case study adds to larger discussions about the effects of industrialization on public mental health and the environment, emphasizing the importance of incorporating public perception into urban planning in order to achieve sustainable development. Full article

Millions of electrostatically actuatable micromirror arrays have been arranged in between windowpanes in inert gas environments, enabling active daylighting in buildings for illumination and climatization. MEMS smart windows can reduce energy consumption significantly. However, to allow personalized light steering for arbitrary user positions with high flexibility, two main limitations must be overcome: first, limited tuning angle spans by MEMS pull-in effects; and second, the lack of a second orthogonal tuning angle, which is highly required. Firstly, design improvements of electrostatically actuatable micromirror arrays are reported by utilizing tailored bottom electrode structures for enlarging the tilt angle (Φ). Considerably larger tuning ranges are presented, significantly improving daylight steering into buildings. Secondly, 2D actuation means free movement of micromirrors via two angles—tilt (Φ) and torsion angle (θ)—while applying two corresponding voltages between the metallic micromirrors and corresponding FTO (fluorine-doped tin oxide) counters bottom electrode pads. In addition, a solution for a notorious problem in MEMS actuation is presented. Micromirror design modifications are necessary to eliminate possible crack formation on metallic structure due to stress concentration during the free movement of 2D actuatable micromirror arrays. The concept, design of micromirror arrays and bottom electrodes, as well as technological fabrication and experimental results are presented and discussed. Full article

Taking Yunyu New Village in Nanyang City, a typical newly built resettlement area of the South-to-North Water Diversion Project of China, as an example, this paper tries to construct a health environment evaluation index system for the resettlement area and determines the priority and content of residential environment renovation in the resettlement area through residents’ health satisfaction evaluation and IPA analysis. The results revealed that six factors, namely, winter insulation, summer heat insulation, quality of domestic drinking water, indoor natural light environment, humanized design, and architectural plane function design, need to be renovated first. For the indoor environment, which is the focus of renovation, the light and heat environments were evaluated via field measurements and simulation experiments. The results show that the indoor comfort, daylighting, and energy savings of the surveyed buildings all fail to meet Chinese building design standards. Corresponding optimization strategies for indoor ventilation, thermal insulation performance of the envelope structure, and window wall ratio are proposed and verified via relevant software simulations and immigrants’ wishes. For the outdoor environment, we investigate the living habits and renovation needs of immigrants from the aspects of public space and courtyard space in the resettlement area and propose corresponding optimization strategies. The results of this research can help enhance the sense of gain and happiness of immigrants in the resettlement and provide a reference for improving the living environment of the same type of immigrant resettlement area. Full article

This study carried out a literature search and selection in accordance with the PRISMA 2020 protocol to conduct a complete review of the literature describing the electrical, photometrical, and colorimetric parameters of LEDs. Based on it, a significant research gap was found in the field of LED-based lighting retrofits. We prove that there is a lack of publications indicating the relationship between the energy consumption of LED retrofits and user preferences concerning the quality of lighting. This article presents an effective new method for selecting LEDs to retrofit typical 3000, 4000, and 6500 K fluorescent lighting installations in buildings. It is shown that when selecting an LED replacement for a fluorescent source, consideration of the classically used parameters in the field of lighting technology to describe the quality of white light, specifically correlated color temperature and the color rendering index, is insufficient. We demonstrate that energy efficiency and the color preference criteria for retrofitted LEDs must be considered and balanced with the potential impact on circadian rhythms as assessed by the melanopic daylight efficacy ratio. This research proves that LED replacements with the best color preference properties (P1 class in the CPC classification of ANSI/IES TM30-20 method) correspond to the least energy-efficient light sources. Full article

Due to limited roof area, photovoltaic (PV) has gradually been installed on other facades of buildings. This research investigates the practical application of a lightweight PV curtain wall. We use EnergyPlus to build a base office building model of fit with a lightweight PV curtain wall. The performance of two typical lightweight PV curtain wall modules is evaluated in five sample Chinese cities of different climates. Simulations were carried out to determine the power generation of faux architectural material PV curtain wall modules (FAM PVCWMs) for the best cavity distance per facade in various cities. We discovered that, in Harbin, Beijing, and Shanghai, the capacity of PV curtain wall modules installed on the south facade is the best, while in Chengdu and Guangzhou, it is the west facade. We also analyzed the power generation and the impact on the indoor environment when installing semi-transparent PV curtain wall modules (ST PVCWMs). Compared with glass, the ST PVCWM’s power generation increased by at least 50%, while the glare index setpoint exceeded time reduced by at least 30.19%. Furthermore, when installed on the north facade of Chengdu and similar cities, it can ensure more than 50% of daylight indexed time and create a more favorable indoor environment. Full article

The pyridinium phenolate punicine is a switchable molecule from Punica granatum. Depending on the pH, punicine exists as a cation, neutral molecule, anion, or dianion. In addition, punicine reacts to light, under the influence of which it forms radical species. We report on three punicine derivatives that possess an adamantyl, 2-methylnonyl, or heptadecyl substituent and on their performance in the flotation of lithium aluminate, an engineered artificial mineral (EnAM) for the recycling of lithium, e.g., from lithium-ion batteries. By optimizing the parameters: pH and light conditions (daylight, darkness), recovery rates of 92% of LiAlO₂ are achieved. In all cases, the flotation of the gangue material gehlenite (Ca₂Al[AlSiO₇]) is suppressed. IR, the contact angle, zeta potential measurements, TG-MS, and PXRD confirm that the punicines interact with the surface of LiAlO₂, which is covered by LiAl₂(OH)₇ after contact to water, resulting in a hydrophobization of the particle. The plasma pretreatment of the lithium aluminate has a significant influence on the flotation results and increases the recovery rates of lithium aluminate in blank tests by 58%. The oxidative plasma leads to a partial dehydratisation of the LiAl₂(OH)₇ and thus to a hydrophobization of the particles, while a reductive plasma causes a more hydrophilic particle surface. Full article

Nuclear protein delivery underlies an array of biotechnological and therapeutic applications. While many variations of protein delivery methods have been described, it can still be difficult or inefficient to introduce exogenous proteins into plants. A major barrier to progress is the cell wall which is primarily composed of polysaccharides and thus only permeable to small molecules. Here, we report a partial enzymatic cell wall digestion-mediated uptake method that efficiently delivers protein into the nucleus of plant cells. Such a method allowed efficient nuclear delivery of green fluorescent protein (GFP) flanked by two nuclear localization sequences (NLS) into Arabidopsis thaliana epidermal root cells without the usual need for large doses of nanoparticles or tissue cultures. We also show that switching from daylight to far-red light-grown conditions promotes effective protein penetration into deep cell layers. This study establishes that a partial enzymatic cell wall degradation could be applied to other cell organelles by changing the localization sequence, paving the way toward the rational engineering of plants. Full article

This pilot study evaluated the design, usability, and practicality of the dPDT@home kit for treating actinic keratoses (AKs) on the face and scalp. The kit allowed patients to manage their treatment at home, reducing hospital visits and utilizing natural sunlight. While patients were very willing to use the kit again, further studies are required to evaluate outcomes and ascertain the need for additional improvements and support. Background/Objectives: Daylight photodynamic therapy (dPDT) is an established effective therapy for superficial mild-to-moderate actinic keratoses (AKs) on the face and scalp. In this project, we redesigned the delivery of dPDT using design principles and the concept of Realistic Medicine to create the dPDT@home kit. This user-friendly and environmentally conscious kit allows patients to manage their AKs at home, reducing the need for hospital visits and ensuring timely treatment to coincide with appropriate weather conditions and to prevent disease progression due to delays in diagnosis and treatment. The initial pilot phase of the study was to evaluate the usability and convenience of the practicalities of the dPDT@home kit. Methods: Patients were instructed to conduct two dPDT@home kit treatments approximately three weeks apart on suitable weather days. After a follow-up telephone consultation from the specialist PDT nurse following the first treatment, patients then completed an initial questionnaire (Questionnaire 1, Q1) to share their experience. A second questionnaire (Q2) was completed 3–6 months after their final treatment to assess treatment outcomes. Results: A total of 16 patients with AK on the face and/or scalp used the dPDT@home kit. Five patients formed an initial pilot group in 2020/21, whose feedback and involvement informed the final product for the larger group of eleven patients (2021/22). All patients reported no issues with receiving the kit or the pro-drug used in the treatment (Q1). Q2 had an 81.25% return rate, with an average willingness score of 8.9/10 to use dPDT@home again. However, patients expressed doubts about their confidence in the treatment’s efficacy, giving an average score of 6.9/10, with preferences leaning towards other treatments, such as hospital-based PDT or cryotherapy. Conclusions: The pilot deployment of the dPDT@home kit identified suitable patients and highlighted the need for comprehensive training and support for both patients and clinicians to deliver dPDT through this novel approach. The kit can reduce the number of hospital visits, but patients still require supervision, which can be provided remotely. The questionnaire outcomes emphasize the importance of setting patient expectations and taking a holistic approach to managing chronic field-change AK. Additionally, the kit’s recyclable components and reliance on natural sunlight promote sustainability and reduce patient travel. Further evaluation is required to determine cost-efficacy, safety, and the potential place of the dPDT@home kit in the therapeutic management of patients with this common and challenging condition. Full article

Autonomous driving (AD) technology has seen significant advancements in recent years; however, challenges remain, particularly in achieving reliable performance under adverse weather conditions such as heavy fog. In response, we propose a multi-class fog density classification approach to enhance the AD system performance. By categorizing fog density into multiple levels (25%, 50%, 75%, and 100%) and generating separate datasets for each class using the CARLA simulator, we improve the perception accuracy for each specific fog density level and analyze the effects of varying fog intensities. This targeted approach offers benefits such as improved object detection, specialized training for each fog class, and increased generalizability. Our results demonstrate enhanced perception of various objects, including cars, buses, trucks, vans, pedestrians, and traffic lights, across all fog densities. This multi-class fog density method is a promising advancement toward achieving reliable AD performance in challenging weather, improving both the precision and recall of object detection algorithms under diverse fog conditions. Full article

The design of reliable and accurate indoor lighting control systems for LEDs’ (light-emitting diodes) color temperature and brightness, in an effort to affect human circadian rhythms, has been emerging in the last few years. However, this is quite challenging since parameters, such as the melanopic equivalent daylight illuminance (mEDI), have to be evaluated in real time, using illuminance values and the spectrum of incident light. In this work, to address these issues, a prototype platform has been built based on the low-cost and low-power Arduino UNO R4 Wi-Fi BLE (Bluetooth Low Energy) board, which facilitates experiments with a new control approach for LEDs’ correlated color temperature (CCT). Together with the aforementioned platform, the methodology for mEDI calculation using an 11-channel multi-spectral sensor is presented. With proper calibration of the sensor, the visible spectrum can be reconstructed with a resolution of 1 nm, making the estimation of mEDI more accurate. Full article

Buildings are responsible for approximately 40% of global energy consumption, putting pressure on the construction industry to mitigate its environmental impact. Therefore, there is an urgent need for innovative solutions to reduce power consumption, particularly in lighting systems. This study’s primary objective was to investigate novel integrated lighting solutions that significantly reduce energy use, as well as to explore their enhancement through Building Information Modelling (BIM) and the Internet of Things (IoT) to improve energy efficiency further and reduce the carbon footprint of buildings. Hence, this literature review examined energy-saving actions, retrofitting practices and interventions across a range of multi-use buildings worldwide, focusing on research from 2019 to 2024. The review was conducted using Scopus and Web of Science databases, with inclusion criteria limited to original research. The objective was to diagnose the goals being undertaken and ultimately validate new actions and contributions to minimise energy consumption. After applying eligibility criteria, 48 studies were included in the review. First, daylight harvesting and retrofitting solutions were examined using the latest technologies and external shading. The review indicates a lack of proper coordination between daylight and electrical lighting, resulting in energy inefficiency. Secondly, it reviews how the integration of BIM facilitates the design process, providing a complete overview of all the building variables, thus improving indoor daylight performance and proper lighting with energy analysis. Lastly, the review addresses the role of the Internet of Things (IoT) in providing real-time data from sensor networks, allowing for continuous monitoring of building conditions. This systematic literature review explores the integration of these fields to address the urgent need for innovative strategies and sustainability in the built environment. Furthermore, it thoroughly analyses the current state of the art, identifying best practices, emerging trends and concrete insight for architects, engineers and researchers. The goal is to promote the widespread adoption of low-carbon systems and encourage collaboration among industry professionals and researchers to advance sustainable building design. Ultimately, a new parametric design framework is proposed, consisting of five iterative phases that cover all design stages. This framework is further enhanced by integrating BIM and IoT, which can be used together to plan, reconfigure, and optimise the building’s performance. Full article