6,138 results on '"AIRBORNE"'
Search Results
2. AI-Powered Microscopy Platform for Airborne Biothreat Detection
- Author
-
Pálhalmi, János, Mező, Anna, Akhgar, Babak, Series Editor, Gkotsis, Ilias, editor, Kavallieros, Dimitrios, editor, Stoianov, Nikolai, editor, Vrochidis, Stefanos, editor, and Diagourtas, Dimitrios, editor
- Published
- 2025
- Full Text
- View/download PDF
3. Host and viral determinants of airborne transmission of SARS-CoV-2 in the Syrian hamster.
- Author
-
Port, Julia, Morris, Dylan, Riopelle, Jade, Yinda, Claude, Avanzato, Victoria, Holbrook, Myndi, Bushmaker, Trenton, Schulz, Jonathan, Saturday, Taylor, Barbian, Kent, Russell, Colin, Perry-Gottschalk, Rose, Shaia, Carl, Martens, Craig, Fischer, Robert, Munster, Vincent, and Lloyd-Smith, James
- Subjects
SARS-CoV-2 ,airborne ,infectious disease ,microbiology ,syrian hamster ,transmission ,variants of concern ,virus kinetics ,viruses ,Cricetinae ,Animals ,Male ,SARS-CoV-2 ,COVID-19 ,Mesocricetus ,Respiratory Aerosols and Droplets - Abstract
It remains poorly understood how SARS-CoV-2 infection influences the physiological host factors important for aerosol transmission. We assessed breathing pattern, exhaled droplets, and infectious virus after infection with Alpha and Delta variants of concern (VOC) in the Syrian hamster. Both VOCs displayed a confined window of detectable airborne virus (24-48 hr), shorter than compared to oropharyngeal swabs. The loss of airborne shedding was linked to airway constriction resulting in a decrease of fine aerosols (1-10 µm) produced, which are suspected to be the major driver of airborne transmission. Male sex was associated with increased viral replication and virus shedding in the air. Next, we compared the transmission efficiency of both variants and found no significant differences. Transmission efficiency varied mostly among donors, 0-100% (including a superspreading event), and aerosol transmission over multiple chain links was representative of natural heterogeneity of exposure dose and downstream viral kinetics. Co-infection with VOCs only occurred when both viruses were shed by the same donor during an increased exposure timeframe (24-48 hr). This highlights that assessment of host and virus factors resulting in a differential exhaled particle profile is critical for understanding airborne transmission.
- Published
- 2024
4. Detection of SARS-CoV-2 in Environment: Current Surveillance and Effective Data Management of COVID-19.
- Author
-
Nadzirah, Sh., Mohamad Zin, Noraziah, Khalid, Arif, Abu Bakar, Nur Faizah, Kamarudin, Siti Syafiqah, Zulfakar, Siti Shahara, Kon, Ken Wong, Muhammad Azami, Nor Azila, Low, Teck Yew, Roslan, Roharsyafinaz, M Nassir, M. Nizar Hadi, Alim, Anis Amirah, Menon, P. Susthitha, Soin, Norhayati, Gopinath, Subash C. B., Abdullah, Huda, Sampe, Jahariah, Zainal Abidin, Hafzaliza Erny, Mohd Noor, Siti Nurfadhlina, and Ismail, Ahmad Ghadafi
- Subjects
- *
SARS-CoV-2 , *VIRAL transmission , *SURFACE contamination , *DATA management , *ENVIRONMENTAL management - Abstract
Since diagnostic laboratories handle large COVID-19 samples, researchers have established laboratory-based assays and developed biosensor prototypes. Both share the same purpose; to ascertain the occurrence of air and surface contaminations by the SARS-CoV-2 virus. However, the biosensors further utilize internet-of-things (IoT) technology to monitor COVID-19 virus contamination, specifically in the diagnostic laboratory setting. The IoT-capable biosensors have great potential to monitor for possible virus contamination. Numerous studies have been done on COVID-19 virus air and surface contamination in the hospital setting. Through reviews, there are abundant reports on the viral transmission of SARS-CoV-2 through droplet infections, person-to-person close contact and fecal-oral transmission. However, studies on environmental conditions need to be better reported. Therefore, this review covers the detection of SARS-CoV-2 in airborne and wastewater samples using biosensors with comprehensive studies in methods and techniques of sampling and sensing (2020 until 2023). Furthermore, the review exposes sensing cases in public health settings. Then, the integration of data management together with biosensors is well explained. Last, the review ended with challenges to having a practical COVID-19 biosensor applied for environmental surveillance samples. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
5. The Application of Ozone Gas in Inactivation of Surface and Airborne SARS-CoV-2 in Hospitals: A Systematic Review.
- Author
-
Past, Vida, Naderi, Maziar, Saremi, Golbarg, Azizi, Paniz, Javadzadeh, Mahla, Shahveh, Shiva, Hosseini, Pegah, Sokhanvaran, Sima, Shahveh, Shaghayegh, Moghimi, Shadi, Hedeshi, Sara, Jalalpour, Azadeh, and Bayat, Zeynab
- Abstract
The outbreak of COVID-19 caused by the novel coronavirus SARS-CoV-2 is a global public health threat. As high-risk environments for transmission, hospitals require effective methods to inactivate the virus on surfaces and in the air to prevent further spread among hospitals. The aim of this systematic review was to evaluate the use of ozone gas to inactivate surface and airborne SARS-CoV-2 in hospital settings. A systematic literature search was performed in databases including PubMed, Scopus and Web of Science from 2019 to 2024. Studies that assessed the use of ozone gas to inactivate SARS-CoV-2 in hospital settings were included. The quality assessment of the studies was done using the Critical Appraisal Skills Program (CASP) tool. A total of 10 studies met the inclusion criteria and were included in the review. Studies have reported that ozone effectively inactivates SARS-CoV-2 on surfaces and air in hospital environments. However, there were variations in ozone concentration, exposure time, and relative humidity (RH) used in each study. Ozone demonstrates promise as an effective disinfectant for inactivating SARS-CoV-2 on surfaces and air in hospital environments. It should be focused on determining the optimal conditions for maximum efficiency and establishing relevant protocols in terms of human health. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
6. A systematic review of the effects of airborne microplastic contamination on human lungs.
- Author
-
Ningrum, Prehatin T., Keman, Soedjajadi, Sulistyorini, Lilis, Sudiana, I. K., Hidayat, Agus, Negoro, Abul H. S., Junaidi, Hasrah, and Kustin
- Subjects
AIR pollution prevention ,AIR pollution ,RISK assessment ,GOVERNMENT policy ,SYSTEMATIC reviews ,MEDLINE ,POLLUTION ,ENVIRONMENTAL exposure ,LUNG diseases ,PLASTICS ,MICROPLASTICS ,ONLINE information services ,GOVERNMENT regulation ,DISEASE risk factors - Abstract
Copyright of African Journal of Reproductive Health is the property of Women's Health & Action Research Centre and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2024
- Full Text
- View/download PDF
7. Comparison between Spatially Resolved Airborne Flux Measurements and Emission Inventories of Volatile Organic Compounds in Los Angeles.
- Author
-
Pfannerstill, Eva, Arata, Caleb, Zhu, Qindan, Schulze, Benjamin, Woods, Roy, Harkins, Colin, Schwantes, Rebecca, McDonald, Brian, Seinfeld, John, Bucholtz, Anthony, Cohen, Ronald, and Goldstein, Allen
- Subjects
California ,air quality ,airborne ,emissions ,fluxes ,inventory ,volatile organic compounds ,United States ,Volatile Organic Compounds ,Los Angeles ,Air Pollutants ,Particulate Matter ,Vehicle Emissions ,Ozone ,Environmental Monitoring ,China - Abstract
Los Angeles is a major hotspot for ozone and particulate matter air pollution in the United States. Ozone and PM2.5 in this region have not improved substantially for the past decade, despite a reduction in vehicular emissions of their precursors, NOx and volatile organic compounds (VOCs). This reduction in traditional sources has made the current emission mixture of air pollutant precursors more uncertain. To map and quantify emissions of a wide range of VOCs in this urban area, we performed airborne eddy covariance measurements with wavelet analysis. VOC fluxes measured include tracers for source categories, such as traffic, vegetation, and volatile chemical products (VCPs). Mass fluxes were dominated by oxygenated VOCs, with ethanol contributing ∼29% of the total. In terms of OH reactivity and aerosol formation potential, terpenoids contributed more than half. Observed fluxes were compared with two commonly used emission inventories: the California Air Resources Board inventory and the combination of the Biogenic Emission Inventory System with the Fuel-based Inventory of Vehicle Emissions combined with Volatile Chemical Products (FIVE-VCP). The comparison shows mismatches regarding the amount, spatial distribution, and weekend effects of observed VOC emissions with the inventories. The agreement was best for typical transportation related VOCs, while discrepancies were larger for biogenic and VCP-related VOCs.
- Published
- 2023
8. Assessing the Resilience of Enteric Bacteria in Manure in Response to Changes in Relative Humidity and UV-B Light.
- Author
-
Leon, Ingrid M., Auvermann, Brent W., Bush, Kevin Jack, Casey, Kenneth, Pinchak, William E., Vinasco, Javier, Lawhon, Sara D., Smith, Jason K., Scott, Harvey Morgan, and Norman, Keri N.
- Subjects
CATTLE manure ,AEROBIC bacteria ,ESCHERICHIA coli ,ENTEROBACTERIACEAE ,PARTICULATE matter ,MICROBIOLOGICAL aerosols - Abstract
Dehydrated manure from agricultural animal feedlots can become aerosolized and may potentially harbor viable antimicrobial-resistant bacteria. Little is known about the dynamics and risk of bacteria in bioaerosols originating from the feedyard environment. Nutrient deficiency, desiccation, UV exposure, temperature, and pH changes can affect bacterial viability. In this study, we investigated the impact of changes in relative humidity (RH) and UV-B exposure on enteric bacterial survival in vitro to simulate environmental conditions in cattle feedyards. Cattle manure samples were placed in two separate chambers with 73% RH and 31% RH, respectively. For the UV-B experiment, samples were placed in a chamber exposed to UV-B (treated) or in a chamber exposed to LED light (control). Samples from both experiments were spiral plated in triplicate onto selective agar media to quantify total aerobic bacteria, E. coli (total and antimicrobial-resistant (AMR)), and Enterococcus spp. (total and AMR). Results showed that enteric bacteria from cattle manure can withstand at least two stress conditions, including low RH levels and UV-B exposure. Moreover, the data revealed that antimicrobial-resistant bacteria can persist in manure under the harsh conditions that may be encountered in a feedyard environment. These findings underscore the need for mitigation strategies in feedlots to minimize the overall risk of bioaerosol formation. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
9. Challenges Facing the Use of Remote Sensing Technologies in the Construction Industry: A Review.
- Author
-
Almohsen, Abdulmohsen S.
- Subjects
REMOTE sensing ,LITERATURE reviews ,CONSTRUCTION management ,CONSTRUCTION projects ,ENVIRONMENTAL management - Abstract
Remote sensing is essential in construction management by providing valuable information and insights throughout the project lifecycle. Due to the rapid advancement of remote sensing technologies, their use has been increasingly adopted in the architecture, engineering, and construction industries. This review paper aims to advance the understanding, knowledge base, and practical implementation of remote sensing technologies in the construction industry. It may help support the development of robust methodologies, address challenges, and pave the way for the effective integration of remote sensing into construction management processes. This paper presents the results of a comprehensive literature review, focusing on the challenges faced in using remote sensing technologies in construction management. One hundred and seventeen papers were collected from eight relevant journals, indexed in Web of Science, and then categorized by challenge type. The results of 44 exemplary studies were reported in the three types of remote sensing platforms (satellite, airborne, and ground-based remote sensing). The paper provides construction professionals with a deeper understanding of remote sensing technologies and their applications in construction management. The challenges of using remote sensing in construction were collected and classified into eleven challenges. According to the number of collected documents, the critical challenges were shadow, spatial, and temporal resolution issues. The findings emphasize the use of unmanned airborne systems (UASs) and satellite remote sensing, which have become increasingly common and valuable for tasks such as preconstruction planning, progress tracking, safety monitoring, and environmental management. This knowledge allows for informed decision-making regarding integrating remote sensing into construction projects, leading to more efficient and practical project planning, design, and execution. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
10. Airborne microplastic contamination across diverse university indoor environments: A comprehensive ambient analysis.
- Author
-
Bhat, Mansoor Ahmad
- Abstract
Microplastics (MPs) have become a growing concern in the context of environmental pollution, with an increasing focus on their presence in indoor environments, including university facilities. This study investigates the presence and characteristics of MPs in different university indoor environments. Initial examination of indoor ambient MPs involved physical characterization through optical microscopy, focusing on classifying MPs by shape and color. Various types of MPs, including fibers, fragments, pellets, foams, films, and lines, were identified, with the most common colors being black, red, blue, and brown. Fragments were the predominant type of MPs found, although accurately quantifying their numbers proved challenging due to the dense sample content. These MPs displayed rough and irregular margins suggestive of abrasion. Subsequent chemical and elemental characterization was conducted using micro-Raman and SEM-EDX, revealing the presence of 25 different types of MPs, including PA 66, PTFE, PP, HDPE, and PE. The study indicates that university inhabitants are exposed to airborne MPs (≥ 2.5–336.89 μm) at inhalation rates of 13.88–18.51 MPs/m
3 and 180–240 MPs daily. These MPs exhibited significant variations in size, and their distribution varied among the different indoor environments studied. SEM-EDX analysis revealed common elements in the identified MPs, with C, O, F, Na, Cl, Al, Si, and others consistently detected. This research is the first to comprehensively analyze MPs in nine different indoor university environments using active sampling. Identifying and reducing MP contamination in these facilities might stimulate more awareness, promote extensive scientific investigation, and facilitate the development of informed policies. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
11. Identification and characterization of microplastics in human nasal samples.
- Author
-
Min, Hyun Jin, Kim, Kyung Soo, Kim, Hyunjung, Gong, Jiyoung, and Jeong, Jinyoung
- Subjects
- *
AIR pollutants , *POLLUTANTS , *NASAL cavity , *MICROPLASTICS , *NASOPHARYNX - Abstract
KEY POINTS Human nasal cavity samples were collected, and presence of microplastics were evaluated. Microplastics were present, and major types were polyethylene, polyester, acrylic polymer, and polypropylene. Further research is needed regarding microplastics and its clinical impact on human nasal cavity. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
12. Reported exposures to respirable crystalline silica during construction tasks and guidance for harmonizing future research.
- Author
-
Jacobs, Neva F. B., E. Zisook, Rachel, and Tarpey, Taylor A.
- Subjects
- *
CONSTRUCTION materials , *PERSONAL protective equipment , *OCCUPATIONAL hazards , *OCCUPATIONAL exposure , *SILICA , *CONSTRUCTION industry , *INDUSTRIAL hygiene , *INDUSTRIAL safety - Abstract
Airborne respirable crystalline silica (RCS) has been a widely recognized hazard in the United States for nearly 100 years, yet it continues to pose a risk to construction tradespersons, among others. RCS exposures vary widely depending on site conditions and tools and materials used. The proper use of engineering, administrative, and personal protective equipment (PPE) controls can effectively reduce exposure to RCS. Historically, others have reviewed available RCS exposure data among construction trades and reported that there were considerable data gaps and variability that needed to be addressed. This current assessment aimed to synthesize available peer-reviewed exposure studies to determine potential RCS exposures during the use of common construction materials and evaluate to what extent data gaps and variability persist. Twenty-eight studies were identified that reported RCS exposure during construction tasks. After conversion to the unit of µg/m3, reported measurements from samples collected for varying durations ranged from 6.0 to 75,500 µg/m3 for work with concrete, 80 to 4,240 µg/m3 for work with brick, <59 to 10,900 µg/m3 for work with mortar, 90 to 44,370 µg/m3 for work with engineered stone, and 70 to 380 µg/m3 for work with roof tile. To better facilitate pooling data across studies, future researchers should report their sample duration, clarify how time-weighted average (TWA) exposure data are calculated, report the silica content of the material being manipulated, and specify whether samples were collected while the task was performed in isolation or on a worksite where other silica-containing materials were also actively handled. When reporting results as respirable quartz, it is important to note whether any other polymorphic forms of silica were detected. It is ultimately the employer's responsibility to train employees and monitor and control RCS exposures on construction worksites. To do this effectively, it is important to have a clear understanding of the tasks, materials, and site conditions where intervention is most urgently needed. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
13. Instrument Design and In-Flight Performance of an Airborne Terahertz Ice Cloud Imager.
- Author
-
Lv, Rongchuan, Gao, Wenyu, Luo, Feng, Li, Yinan, He, Zheng, Wang, Congcong, Zhang, Yan, Zhang, Chengzhen, Sun, Daozhong, Shang, Jian, Dou, Fangli, and Wang, Xiaodong
- Subjects
- *
ICE clouds , *ANTENNA feeds , *ICE , *TYPHOONS , *OCEAN , *FORECASTING - Abstract
The Airborne Terahertz Ice Cloud Imager (ATICI) is an airborne demonstration prototype of an ice cloud imager (ICI), which will be launched on the next generation of Fengyun satellites and plays an important role in heavy precipitation detection, typhoon, and medium-to-short-term meteorological/ocean forecasting. At present, it has 13 frequency channels covering 183–664 GHz, which are sensitive to scattering by cloud ice. This paper provides an overview of ATICI and proposes a receiving front-end design scheme using a planar mirror and a quasi-optical feed network which improves the main beam efficiency of each frequency band, with measured values better than 95.5%. It can detect factors such as ice particle size, ice water path, and ice water content in clouds by rotating the circular scanning of the antenna feed system. A high-sensitivity receiver system has been developed and tested for verification. The flight verification results show that the quasi-optical feed network subsystem works well and performs stably under vibration and temperature changes. The system sensitivity is better than 1.5 K, and the domestically produced high-frequency receiver has stable performance, which can meet the conditions of satellite applications. The ATICI performs well and meets expectations, verifying the feasibility of the Fengyun-5 ICI payload. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
14. 3D modelling of ground magnetic-source airborne TEM data for anisotropic media based on the rational Krylov method.
- Author
-
Guan, Qingchen, Tan, Handong, and Yu, Cui
- Subjects
- *
MAXWELL equations , *ANISOTROPY , *FINITE difference method , *MATRIX exponential , *ELECTRIC transients , *KRYLOV subspace - Abstract
With the rapid development of the transient electromagnetic method (TEM), the numerical simulations of three-dimensional anisotropic media have garnered attention. This study used the rational Krylov method to realise the three-dimensional modelling of the ground magnetic-source airborne transient electromagnetic data for arbitrary anisotropic media. First, based on Maxwell's equations, a time-domain electromagnetic equation was derived for anisotropic media. The finite difference method was employed to discretise the equation, and the electromagnetic field was then expressed as the product of an exponential matrix and a vector related to the source. Subsequently, the rational Arnoldi algorithm was adopted to construct the rational Krylov subspace orthogonal basis vectors, and the electromagnetic fields at different times were obtained based on a model reduction strategy. The accuracy of the proposed algorithm was verified through the comparisons of its results with those of other software packages. We calculated the response for different anisotropic parameters of the typical three-dimensional anisotropic models, and analysed the influence of the anisotropic media on the ground magnetic-source airborne transient electromagnetic data. The proposed three-dimensional forward TEM algorithm provides important technical support for identifying the anisotropic geological bodies and lays the foundation for further inversion research. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
15. Design of an Airborne Low-Light Imaging System Based on Multichannel Optical Butting.
- Author
-
Peng, Jianwei, Yang, Hongtao, Lei, Yangjie, Yu, Wanrong, Chen, Weining, and Zhang, Guangdong
- Subjects
IMAGING systems ,FLIGHT testing ,DETECTORS ,DIAGNOSTIC imaging ,PRISMS ,LUMINOUS flux - Abstract
For the purpose of achieving long-range, high-resolution, and ultra-wide-swath airborne earth imaging at extremely low-light levels (0.01 Lux), a low-light imaging system built on multi-detector optical butting was researched. Having decomposed the system's specifications and verified its low-light imaging capability, we proposed to employ an optical system with a large relative aperture and low distortion and achieve imaging through the field-of-view (FOV) butting facilitated by eight 1080P high-sensitivity scientific complementary metal-oxide semiconductor (SCMOS) detectors. This paper elaborates on the design concept of the mechanical configuration of the imaging system; studies the calculation method of the structural parameters of the reflection prism; provides mathematical expressions for geometric parameters, such as the length and width of the splicing prism; and designs in detail the splicing structure of six reflection prisms for eight-channel beam splitting. Based on the design and computational results, a high-resolution, wide-swath imaging system for an ambient illuminance of 0.01 Lux was developed. Exhibiting a ground sampling distance (GSD) of 0.5 m (at a flight height of 5 km), this low-light imaging system keeps the FOV overlap ratio between adjacent detectors below 3% and boasts an effective image resolution of 4222 × 3782. The results from flight testing revealed that the proposed imaging system is capable of generating wide-swath, high-contrast resolution imagery under airborne and low-light conditions. As such, the way the system is prepared can serve as a reference point for the development of airborne low-light imaging devices. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
16. ML meets aerospace: challenges of certifying airborne AI
- Author
-
Bastian Luettig, Yassine Akhiat, and Zamira Daw
- Subjects
artificial intelligence ,aviation ,certification ,airborne ,assurance ,machine learning ,Motor vehicles. Aeronautics. Astronautics ,TL1-4050 ,Electrical engineering. Electronics. Nuclear engineering ,TK1-9971 - Abstract
Artificial Intelligence (AI) technologies can potentially revolutionize the aerospace industry with applications such as remote sensing data refinement, autonomous landing, and drone-based agriculture. However, safety concerns have prevented the widespread adoption of AI in commercial aviation. Currently, commercial aircraft do not incorporate AI components, even in entertainment or ground systems. This paper explores the intersection of AI and aerospace, focusing on the challenges of certifying AI for airborne use, which may require a new certification approach. We conducted a comprehensive literature review to identify common AI-enabled aerospace applications, classifying them by the criticality of the application and the complexity of the AI method. An applicability analysis was conducted to assess how existing aerospace standards - for system safety, software, and hardware - apply to machine learning technologies. In addition, we conducted a gap analysis of machine learning development methodologies to meet the stringent aspects of aviation certification. We evaluate current efforts in AI certification by applying the EASA concept paper and Overarching Properties (OPs) to a case study of an automated peripheral detection system (ADIMA). Aerospace applications are expected to use a range of methods tailored to different levels of criticality. Current aerospace standards are not directly applicable due to the manner in which the behavior is specified by the data, the uncertainty of the models, and the limitations of white box verification. From a machine learning perspective, open research questions were identified that address validation of intent and data-driven requirements, sufficiency of verification, uncertainty quantification, generalization, and mitigation of unintended behavior. For the ADIMA system, we demonstrated compliance with EASA development processes and achieved key certification objectives. However, many of the objectives are not applicable due to the human-centric design. OPs helped us to identify and uncover several defeaters in the applied ML technology. The results highlight the need for updated certification standards that take into account the unique nature of AI and its failure types. Furthermore, certification processes need to support the continuous evolution of AI technologies. Key challenges remain in ensuring the safety and reliability of AI systems, which calls for new methodologies in the machine learning community.
- Published
- 2024
- Full Text
- View/download PDF
17. Improving the accuracy of SIF quantified from moderate spectral resolution airborne hyperspectral imager using SCOPE: assessment with sub-nanometer imagery
- Author
-
A. Belwalkar, T. Poblete, A. Hornero, R. Hernández-Clemente, and P.J. Zarco–Tejada
- Subjects
Solar-induced chlorophyll fluorescence ,SIF ,Narrow-band ,SCOPE ,Airborne ,Hyperspectral ,Physical geography ,GB3-5030 ,Environmental sciences ,GE1-350 - Abstract
Hyperspectral imaging of solar-induced chlorophyll fluorescence (SIF) is required for plant phenotyping and stress detection. However, the most accurate instruments for SIF quantification, such as sub-nanometer (≤1-nm full-width at half-maximum, FWHM) airborne hyperspectral imagers, are expensive and uncommon. Previous studies have demonstrated that standard narrow-band hyperspectral imagers (i.e., 4–6-nm FWHM) are more cost-effective and can provide far-red SIF quantified at 760 nm (SIF760), which correlates strongly with precise sub-nanometer resolution measurements. Nevertheless, narrow-band SIF760 quantifications are subject to systematic overestimation owing to the influence of the spectral resolution (SR). In this study, we propose a modelling approach based on the Soil Canopy Observation, Photochemistry and Energy Fluxes (SCOPE) model with the objective of enhancing the accuracy of absolute SIF760 levels derived from standard airborne hyperspectral imagers in practical settings. The performance of the proposed method was evaluated using airborne imagery acquired from two airborne hyperspectral imagers (FWHM ≤ 0.2-nm and 5.8-nm) flown in tandem on board an aircraft that collected data from two different wheat and maize phenotyping trials. Leaf biophysical and biochemical traits were first estimated from airborne narrow-band reflectance imagery and subsequently used as SCOPE model inputs to simulate a range of top-of-canopy (TOC) radiance and SIF spectra at 1-nm FWHM. The SCOPE simulated radiance spectra were then convolved to match the spectral configuration of the narrow-band imager to compute the 5.8-nm FWHM SIF760. A site-specific model was constructed by employing the convolved 5.8-nm SR SIF760 as the independent variable and the 1-nm SR SIF760 directly simulated by SCOPE as the dependent variable. When applied to the airborne dataset, the estimated SIF760 at 1-nm SR from the standard narrow-band hyperspectral imager matched the reference sub-nanometer quantified SIF760 with root mean square error (RMSE) less than 0.5 mW/m2/nm/sr, yielding R2 = 0.93–0.95 from the two experiments. These results suggest that the proposed modelling approach enables the interpretation of SIF760 quantified using standard hyperspectral imagers of 4–6 nm FWHM for stress detection and plant physiological condition assessment.
- Published
- 2024
- Full Text
- View/download PDF
18. Airborne occupational sensitization and allergic contact dermatitis from streptomycin with cross‐reactivity to tobramycin.
- Author
-
De Munck, Kitty, Pyl, Jeroen, Dendooven, Ella, Goossens, An, and Aerts, Olivier
- Subjects
- *
MEDICAL personnel , *CONTACT dermatitis , *NEOMYCIN , *TOBRAMYCIN , *OCCUPATIONAL exposure - Abstract
The article discusses a case of airborne occupational sensitization and allergic contact dermatitis from streptomycin, with cross-reactivity to tobramycin, in a 44-year-old female working in a pharmaceutical company. Despite wearing protective gear, the patient experienced skin problems after handling streptomycin powder, which improved after avoiding contact with the substances. Patch tests confirmed the allergic reactions, highlighting the importance of considering cross-reactivity between aminoglycoside antibiotics. The authors recommend avoiding direct and indirect contact with streptomycin and tobramycin to prevent further symptoms. [Extracted from the article]
- Published
- 2024
- Full Text
- View/download PDF
19. Research on the Loading Mode of Shipborne Fluidized Cargo
- Author
-
Xiang, Meimei, Chan, Albert P. C., Series Editor, Hong, Wei-Chiang, Series Editor, Mellal, Mohamed Arezki, Series Editor, Narayanan, Ramadas, Series Editor, Nguyen, Quang Ngoc, Series Editor, Ong, Hwai Chyuan, Series Editor, Sachsenmeier, Peter, Series Editor, Sun, Zaicheng, Series Editor, Ullah, Sharif, Series Editor, Wu, Junwei, Series Editor, Zhang, Wei, Series Editor, Zhao, Gaofeng, editor, Satyanaga, Alfrendo, editor, Ramani, Sujatha Evangelin, editor, and Abdel Raheem, Shehata E., editor
- Published
- 2024
- Full Text
- View/download PDF
20. Assessment of the Phytochemical Constituents and Metabolites in the Medicinal Plants and Herbal Medicine Used in the Treatment and Management of Respiratory Diseases
- Author
-
Kumar, Prasann, Saini, Lalit, Sharma, Monika, Mérillon, Jean-Michel, Series Editor, Ramawat, Kishan Gopal, Series Editor, Pavlov, Atanas I., Editorial Board Member, Ekiert, Halina Maria, Editorial Board Member, Aggarwal, Bharat B., Editorial Board Member, Jha, Sumita, Editorial Board Member, Wink, Michael, Editorial Board Member, Waffo-Téguo, Pierre, Editorial Board Member, Riviere, Céline, Editorial Board Member, Izah, Sylvester Chibueze, editor, Ogwu, Matthew Chidozie, editor, and Akram, Muhammad, editor
- Published
- 2024
- Full Text
- View/download PDF
21. Design of Dual-Band Airborne Passive Millimeter Wave Radiation Measurement System and Scanning Mode
- Author
-
Liu, Weili, Lu, Hailiang, Chen, Jieqia, Chang, Chao, editor, Zhang, Yaxin, editor, Zhao, Ziran, editor, and Zhu, Yiming, editor
- Published
- 2024
- Full Text
- View/download PDF
22. Predictive monitoring of soil organic carbon using multispectral UAV imagery: a case study on a long-term experimental field
- Author
-
Reyes, Javier, Wiedemann, Werner, Brand, Anna, Franke, Jonas, and Ließ, Mareike
- Published
- 2024
- Full Text
- View/download PDF
23. Evaluating Aerosol Optical Depth Retrieved From VIIRS Using Global Scale, Multi‐Seasonal Airborne Observations.
- Author
-
Wang, Siyuan, Brock, Charles, Kondragunta, Shobha, Laszlo, Istvan, and McDonald, Brian
- Subjects
AEROSOLS ,MINERAL dusts ,INFRARED imaging ,AIR quality ,CLIMATE research ,SEA salt ,SMOKE ,SOOT - Abstract
Aerosol optical depth (AOD) is a vital parameter in atmospheric research. Using observations of the Visible Infrared Imaging Radiometer Suite (VIIRS), onboard Suomi National Polar‐orbiting Partnership (Suomi‐NPP) and NOAA‐20 satellites, National Oceanic and Atmospheric Administration (NOAA) produces near‐real time AOD product with high pixel resolution (750 m), wide swath width (3,040 km), and a 16‐day repeat cycle. Here we report the evaluation of the NOAA/VIIRS AOD using a comprehensive aerosol data set, derived from a global‐scale, multi‐seasonal airborne mission, the NASA Atmospheric Tomography Mission (ATom). This data set includes rich physical and chemical information, such as size distributions, chemical compositions, optical properties, and hygroscopicities of major aerosol types, including dust, sea salt, smoke, internally mixed sulfate/nitrate/organics particles (non‐smoke), black carbon, etc. Globally, VIIRS AOD (Suomi‐NPP and NOAA‐20) shows good agreement with the ATom AOD in the moderate to high AOD range (>0.3), with respect to measurement uncertainties (orthogonal distance regression fitting slope: 1.5 ± 0.2 for Suomi‐NPP and 1.6 ± 0.5 for NOAA‐20; correlation coefficient: 0.85 for Suomi‐NPP and 0.73 for NOAA‐20). There is a persistent bias in the low AOD range (<0.3) on the order of 0.03, likely reflecting systematic errors on VIIRS and/or the ATom AOD product. Ångström exponent reported by VIIRS shows excellent agreement with ATom results within expected uncertainties. Given the unique insights revealed by the ATom AOD and aerosol property data set, it is desirable to have ATom‐like comprehensive payloads in future airborne satellite validation programs. Plain Language Summary: Aerosol optical depth (AOD) plays a crucial role in air quality and climate. Satellites have been used to retrieve AOD and other aerosol properties for decades; but satellite retrievals are indirect measurements and need validation using direct measurements. Visible Infrared Imaging Radiometer Suite (VIIRS) is the state‐of‐the‐art instrument that retrieves AOD along with other aerosol properties. In this work, we use the comprehensive aerosol data set from the recent global‐scale, multi‐seasonal ATom field campaign, to evaluate the operational VIIRS AOD product on two satellites (NOAA‐20 and SNPP). This data set includes rich physical and chemical information, such as size distributions, chemical compositions, optical properties, and hygroscopicities of major aerosol types, including dust, sea salt, smoke, internally mixed sulfate/nitrate/organics particles, black carbon, etc. Our analysis shows that the operational VIIRS AOD product is generally accurate and robust. A small bias in the low AOD range has been identified, which could be partially explained by the atmospheric variability, but likely reflects systematic errors on VIIRS and/or the ATom AOD product. Our effort further justifies the global scale suborbital airborne missions (such as HIPPO and ATom) and its unique role in atmospheric/climate research as well as operations. Key Points: National Oceanic and Atmospheric Administration (NOAA)/Visible Infrared Imaging Radiometer Suite (VIIRS) Aerosol optical depth (AOD) (Suomi National Polar‐orbiting Partnership [Suomi‐NPP] and NOAA‐20) generally shows good agreement with the AOD product derived from global‐scale airborne observationsThere is a persistent bias in the low AOD range (<0.3), likely reflecting systematic errors on VIIRS and/or the ATom AOD productComprehensive aerosol observations offer invaluable information for satellite validation and model evaluation [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
24. Temporal Variation and Phylogeny of Air and Surface Microflora in Relation to Occupancy Patterns in a Higher Education Institution (HEI).
- Author
-
Laxamana, Jess Rafael I., Reyes, Daniela Mae Kiana T., Santos, Raphael L., and Paraoan, Cielo Emar M.
- Subjects
- *
UNIVERSITIES & colleges , *PHYLOGENY , *BACILLUS (Bacteria) , *BACTERIAL contamination , *GAMMAPROTEOBACTERIA - Abstract
People not only inhale life-sustaining oxygen but also traces of bacteria and even inanimate surfaces introduce microorganisms to one's bodies. However, the diversity and richness of bacterial communities both indoor and outdoor in a Philippine HEI in relation to human occupancy patterns remain relatively unexplored. Hence, the study aimed to bridge this gap. Microflora were collected using settle plates and swabbing method and identified by comparing their 16s rRNA gene amplicons using the Basic Local Alignment Tool. Several isolates were found to have biological implications in health (e.g. Staphylococcus haemolyticus and Bacillus clarus) and biotechnology (e.g. Rhodococcus pyridinivorans and Bacillus altitudinis). The phylogeny of samples exhibited close cohesion from the genus level, hence forming monophyletic taxa -- under the classes Bacilli, Gammaproteobacteria, and Actinomycetes. Furthermore, statistical results established the significant relationship between indoor air and outdoor surface microbial load with the volume of occupants, as opposed to outdoor air and indoor surfaces. The analysis also revealed a strong correlation between the volume of occupants and indoor air microbial concentration (p = 0.002, R = 0.998), likewise in the case of indoor and outdoor surface bacterial contamination (p = 0.036, R = 0.664). Additionally, there was a significant difference in the indoor and outdoor air microbial load following human occupancy patterns in the area (p = 0.018). Findings of the study provide a foundation for understanding air and surface-borne flora, as well as a basis for the enhancement of health and safety standards for building inhabitants. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
25. Forest Aboveground Biomass Estimation and Inventory: Evaluating Remote Sensing-Based Approaches.
- Author
-
Khan, Muhammad Nouman, Tan, Yumin, Gul, Ahmad Ali, Abbas, Sawaid, and Wang, Jiale
- Subjects
FOREST biomass ,BIOMASS estimation ,REMOTE sensing ,RANDOM forest algorithms ,LANDSAT satellites ,TREE height - Abstract
Remote sensing datasets offer robust approaches for gaining reliable insights into forest ecosystems. Despite numerous studies reviewing forest aboveground biomass estimation using remote sensing approaches, a comprehensive synthesis of synergetic integration methods to map and estimate forest AGB is still needed. This article reviews the integrated remote sensing approaches and discusses significant advances in estimating the AGB from space- and airborne sensors. This review covers the research articles published during 2015–2023 to ascertain recent developments. A total of 98 peer-reviewed journal articles were selected under the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Among the scrutinized studies, 54 were relevant to spaceborne, 22 to airborne, and 22 to space- and airborne datasets. Among the empirical models used, random forest regression model accounted for the most articles (32). The highest number of articles utilizing integrated dataset approaches originated from China (24), followed by the USA (15). Among the space- and airborne datasets, Sentinel-1 and 2, Landsat, GEDI, and Airborne LiDAR datasets were widely employed with parameters that encompassed tree height, canopy cover, and vegetation indices. The results of co-citation analysis were also determined to be relevant to the objectives of this review. This review focuses on dataset integration with empirical models and provides insights into the accuracy and reliability of studies on AGB estimation modeling. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
26. The Oxidative Potential of Airborne Particulate Matter Research Trends, Challenges, and Future Perspectives—Insights from a Bibliometric Analysis and Scoping Review.
- Author
-
Sánchez, Luis Felipe, Villacura, Loreto, Catalán, Francisco, Araya, Richard Toro, and Guzman, Manuel A. Leiva
- Subjects
BIBLIOMETRICS ,PARTICULATE matter ,CAPACITY building ,AIR warfare ,RESEARCH personnel ,CLIMATE change - Abstract
This study is a comprehensive analysis of the oxidative potential (OP) of particulate matter (PM) and its environmental and health impacts. The researchers conducted a bibliometric analysis and scoping review, screening 569 articles and selecting 368 for further analysis. The study found that OP is an emerging field of study, with a notable increase in the number of publications in the 2010s compared to the early 2000s. The research is primarily published in eight journals and is concentrated in a few academic and university-based institutions. The study identified key research hotspots for OP-PM, emphasizing the importance of capacity building, interdisciplinary collaboration, understanding emission sources and atmospheric processes, and the impacts of PM and its OP. The study highlighted the need to consider the effects of climate change on OP-PM and the regulatory framework for PM research. The findings of this study will contribute to a better understanding of PM and its consequences, including human exposure and its effects. It will also inform strategies for managing air quality and protecting public health. Overall, this study provides valuable insights into the field of OP-PM research and highlights the need for continued research and collaboration to address the environmental and health impacts of PM. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
27. Lithology and subsurface structures related to gold mineralisation in the Kibati prospect, Mozambique belt in eastern Tanzania, with implications for gold exploration.
- Author
-
Balambirwa, Onesphorius, Mulibo, Gabriel D., and Msabi, Michael M.
- Subjects
- *
GEOLOGICAL mapping , *PROSPECTING , *GOLD futures , *OUTCROPS (Geology) , *SHEAR zones - Abstract
This paper provides an insight into the structures, lithologies, and potential zones and their relationships to gold mineralisation that were investigated to decipher the controls of gold mineralisation at the Kibati Gold Prospect within the Mozambique Belt. Although the Kibati area is located within the gold mineralised zone, lithology and subsurface geological structures associated with gold mineralisation are not well studied. The available high-resolution aeromagnetic data have not yet also been analysed and interpreted to derive geological features that are useful in mineral exploration. The investigation of the structures and lithologies was accomplished through integrated interpretation of high-resolution aeromagnetic data, ground magnetic data, geological mapping, and rock sampling. Aeromagnetic and ground magnetic results reveal the presence of two structural systems, which were previously not identified that trend in NW–SE and NE–SW, with the NW–SE being the dominant control of gold mineralisation. The subsurface structure with NW–SE trending controls the mineralised fluids as a consequence of gold mineralisation in the surface lithologies. Petrography and geological mapping show that granitic gneiss, garnet-biotite quartzo-feldspathic gneiss, dolerite, and amphibolite are the main exposed outcrops where the first two identified types of gneisses, based on their protolith, were previously not specified. Based on the gold assay results, which are persistent and collinear to the structural trend of NW–SE picked out by magnetic data, two (2) potential blocks (A and B) were identified. The trend of the structure in blocks A and B when overlaid with gold anomalies indicates that most of the gold concentrations are located in block B and the highest value of gold concentrations is located in block A where gold values range from 10.19 to 19.680 g/t in block A and 0.0623 to 4.419 g/t in block B. The difference in gold values between blocks A and B is due to the variation in the degree of alteration. The integration of the results indicates that the gold mineralisation in the Kibati area is structurally controlled and concentrated in shear zones. The findings therefore, indicate that the Mozambique Belt is potential for gold mineralisation and provide a warrant for future plan for gold exploration. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
28. Evaluation and Wind Field Detection of Airborne Doppler Wind Lidar with Automatic Intelligent Processing in North China.
- Author
-
Zhang, Xu, Lin, Zhifeng, Gao, Chunqing, Han, Chao, Fan, Lin, and Zhao, Xinxi
- Subjects
- *
DOPPLER lidar , *WIND measurement , *WEATHER balloons , *ATMOSPHERIC circulation , *WIND speed - Abstract
Airborne wind measurement is of great significance for understanding atmospheric motion and meteorological monitoring. In this paper, we present the development and verification of an airborne Doppler wind lidar (ADWL), featuring an approach proposed to integrate a real-time wind retrieval method with an intelligent processing method for automatic adaptive wind detection. Several verification experiments were conducted to evaluate the measurement effectiveness, including comparisons with a calibrated ground-based Doppler wind lidar (GDWL) and a sounding balloon. Compared with the sounding balloon, the ADWL demonstrated mean errors of 0.53 m/s for horizontal wind velocity and 4.60° for wind direction. The correlation coefficients consistently exceeded 0.98 in all linear analyses. Employed in multiple airborne wind detection events in North China at altitudes up to 6600 m, the ADWL provided effective wind field results with a vertical resolution of 50 m and a data rate of 2 Hz. The wind field results obtained during the detection events validate the ADWL's capabilities in diverse environments and underscore its potential for the comprehensive detection of meteorological information. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
29. Airborne Infection Control measures among Government and Private Health Facilities in a hilly district of North India.
- Author
-
Kumar, Mohinder, Vohra, Jai Gopal, Pathania, Abhishek, and Singh, Gurmeet
- Subjects
- *
CROSS infection prevention , *PREVENTION of infectious disease transmission , *MEDICAL protocols , *PUBLIC hospitals , *CROSS-sectional method , *INFECTION control , *HUMAN services programs , *PROPRIETARY hospitals , *AIR microbiology , *EVALUATION of human services programs , *HEALTH policy , *DESCRIPTIVE statistics , *CHI-squared test , *RESEARCH , *HEALTH facilities , *DATA analysis software - Abstract
Introduction: Guidelines for Airborne Infection Control in Health Care Settings were published in the 2010 to reduce Airborne Infections in health service providers and visitors to health facilities. Objectives: To evaluate healthcare facilities regarding implementation of Guidelines for Airborne Infection Control in Health Care Settings. Methods: An analytic, cross- sectional, health care facility-based study in the district Solan of Himachal Pradesh. A total 53 health care facilities from both public and private sectors were assessed and compared. Results: The implementation of these guidelines was unsatisfactory. Government health care facilities were better implementing the guidelines, compared to the private sector. Conclusion: The guidelines are over a decade old and implementation is not optimal. Efforts and emphasis are required to be put into implementation of these guidelines in health care facilities. An update of policy with stringent penalties are advocated for better compliance in the private sector. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
30. Aircraft-derived CH4 emissions from surface and in-situ mining activities in the Alberta oil sands region
- Author
-
R.M. Staebler, J. Liggio, K.L. Hayden, Z. Oldham, R.L. Mittermeier, S.M. Li, K. MacKay, G.R. Wentworth, T.W. Tokarek, S.C. Smyth, C. Mihele, A. Leithead, and M. Wheeler
- Subjects
Methane ,Emissions ,Airborne ,Alberta oil sands ,Open-pit ,In-situ ,Environmental pollution ,TD172-193.5 ,Meteorology. Climatology ,QC851-999 - Abstract
The identification and reduction of methane sources is considered an important part of the fight to stem greenhouse gas (GHG) emissions to the atmosphere. One of the largest industrial contributors to national GHG emissions in Canada is the Alberta Oil Sands Region. To quantify and investigate the spatial distribution and temporal variability of methane emissions from this region, airborne measurements were conducted in 2017 and 2018 with three aircraft. 59 flights were conducted in total to assess emissions for both open-pit and in-situ facilities, in both cold and warm seasons. Derived emission rates were higher than those reported in national inventories by 30%–96% depending on the facility. In-situ facilities had emission rates an order of magnitude lower than surface mining operations and differed significantly from inventory estimates. No statistical differences in CH4 emissions between cold and warm seasons were observed, substantiating the use of simple upscaling to annual emissions within inventories. Rather than confirming a reported decrease in emissions between 2013 and 2018, the measurements suggest essentially no change from the 18 t h−1 for the region observed in 2013. Overall, the results suggest that current methods of CH4 emission determination within the oil sands region, for use in reporting, require improvement.
- Published
- 2024
- Full Text
- View/download PDF
31. Routes of SARS-Cov2 transmission in the intensive care unit: A multicentric prospective study
- Author
-
Yacine Tandjaoui-Lambiotte, Alexandre Elabbadi, Boubaya Marouane, Sebastien Besset, Damien Roux, Nathan Ebstein, Pascal Pineau, Agnes Marchio, Coralie Bloch-Queyrat, Alexandra Lomont, Chakib-Ahmed Alloui, Athenaïs Gerber, Heloise Delagrèverie, Yves Cohen, Jean Ralph Zahar, and Guillaume Voiriot
- Subjects
SARS-CoV-2 ,Viral shedding ,Airborne ,Viral contamination ,Intensive care unit ,Infectious and parasitic diseases ,RC109-216 ,Public aspects of medicine ,RA1-1270 - Abstract
Background: The risk of SARS-CoV-2 transmission to health care workers in intensive care units (ICU) and the contribution of airborne and fomites to SARS-CoV-2 transmission remain unclear. To assess the rate of air and surface contamination and identify risk factors associated with this contamination in patients admitted to the ICU for acute respiratory failure due to SARS-CoV-2 pneumonia. Methods: Prospective multicentric non-interventional study conducted from June 2020 to November 2020 in 3 French ICUs. For each enrolled patient, 3 predefined surfaces were swabbed, 2 air samples at 1 m and 3 m from the patient’s mouth and face masks of 3 health care workers (HCW) were collected within the first 48 h of SARS-CoV-2 positive PCR in a respiratory sample. Droplet digital PCR and quantitative PCR were performed on different samples, respectively. Results: Among 150 included patients, 5 (3.6%, 95%CI: 1.2% to 8.2%) had positive ddPCR on air samples at 1 m or 3 m. Seventy-one patients (53.3%, CI95%: 44.5% to 62.0%) had at least one surface positive. Face masks worn by HCW were positive in 6 patients (4.4%, CI: 1.6% to 9.4%). The threshold of RT-qPCR of the respiratory sample performed at inclusion (odds ratio, OR= 0.88, 95%CI: 0.83 to 0.93, p
- Published
- 2024
- Full Text
- View/download PDF
32. Demonstration of a Combined Active/Passive L-Band Microwave Remote Sensing Airborne Instrument
- Author
-
Mehmet Ogut, Sidharth Misra, Xavier Bosch-Lluis, Isaac Ramos-Perez, Ross Williamson, Chun Sik Chae, Andreas Colliander, and Simon H. Yueh
- Subjects
Airborne ,balanced amplifier ,radar ,radiometer ,receivers ,radio frequency interference (RFI) ,Ocean engineering ,TC1501-1800 ,Geophysics. Cosmic physics ,QC801-809 - Abstract
The passive and active L-band system (PALS) is an airborne microwave instrument suite that combines a separate radar and radiometer airborne instrument with a common antenna. PALS has been used for salinity, wind speed, and soil moisture (SM) measurements, which is critical for calibration and validation of the SM active passive satellite brightness temperature measurements. The combined 1.413 GHz radiometer and 1.26 GHz radar measurements can provide high-accuracy SM measurements over vegetated areas. The new upgraded version of the PALS instrument employs a novel single-chain receiver topology and combines the radar and radiometer instruments. The reduced-noise single-chain receiver PALS instrument was deployed on a DC-3 aircraft for SM measurement in the summer of 2019.
- Published
- 2024
- Full Text
- View/download PDF
33. Highly Integrated Low-Profile Multilayer Dual-Polarized Phased Array Antenna With Truncated Cavities for First Pulsed Bistatic L-Band Airborne SAR Sensor
- Author
-
Diego Lorente, Markus Limbach, Bernd Gabler, Hector Esteban, and Vicente E. Boria
- Subjects
Airborne ,beamforming ,bistatic ,integration ,phased array antenna ,truncated cavity ,Electrical engineering. Electronics. Nuclear engineering ,TK1-9971 - Abstract
Synthetic Aperture Radar (SAR) has become, nowadays, one of the most important techniques in remote-sensing, and the increasing interest in Earth monitoring reinforces this trend. Next-generation SAR sensors will enhance the radar resolution capabilities by means of digital beamforming (DBF) techniques along with multistatic systems. In order to support the technological development of future spaceborne SAR missions, airborne sensors become an essential scope of research. Thereby, future airborne SAR systems demand enhanced DBF capabilities that involve phased array antennas with a high density of array elements. However, the antenna aperture size is significantly limited in airborne applications, which leads to low-profile and highly integrated antenna solutions, becoming a more challenging task for lower frequency operations such as L-band. In this work, a compact L-band dual-polarized multilayer phased array antenna with beam steering in elevation, developed for the next-generation German Aerospace Center (DLR) airborne SAR system, is presented. The proposed design makes use of truncated cavities to improve the array element isolation and provides 66% more antenna elements than the previous L-band phased array of the current DLR airborne SAR sensor with the same antenna aperture size. Measurements of a manufactured prototype show an antenna bandwidth of almost 20%, matching levels better than 17 dB, up to 15 dB gain, and cross-polarization suppression values higher than 35 dB. Thus, the proposed work will allow the application of advanced DBF techniques in the upcoming first pulsed bistatic L-band airborne SAR sensor.
- Published
- 2024
- Full Text
- View/download PDF
34. Individual Inhalation Exposure to Phthalates and Their Associations with Anthropometric and Physiological Indices in Primary School Children in Jinan, China
- Author
-
Haoming Yang, Lixin Wang, Yuchen Wang, Ziyan Meng, Qinghua Sun, Jianlong Fang, Yu Zhong, and Zihao Huang
- Subjects
phthalates ,airborne ,inhalation exposure ,school-age children ,associations ,Building construction ,TH1-9745 - Abstract
Phthalates are commonly found in indoor environments. Consequently, children may be exposed to phthalates through the air, potentially causing health issues. We collected 72 air samples from 60 households and 12 classrooms in Jinan, surveyed and health-examined children, assessed their phthalate inhalation exposure, and analyzed the associations between inhalation exposure levels and children’s anthropometric and physiological indicators. Eight phthalates were detected in children’s households and classrooms, with detection frequencies ranging from 91.6% to 100%. Di-iso-butyl phthalate (DiBP), di-n-butyl phthalate (DnBP), and di (2-ethylhexyl) phthalate (DEHP) were the predominant phthalates. Children’s indoor inhalation exposure to phthalates ranged from 8.90 to 147 ng/(kg·day), with DEHP being the main inhaled phthalate. The non-carcinogenic risks of indoor environments where children live are within acceptable limits. DEHP has a low carcinogenic risk. Di-n-octyl phthalate (DnOP) exposure was associated with a decrease in body mass index z-score, waist circumference, and hip circumference. Additionally, DEHP exposure was negatively associated with the waist-to-hip ratio. DiBP exposure was negatively associated with the systolic blood pressure z-score, while DnOP exposure was negatively associated with the diastolic blood pressure z-score. Furthermore, DEHP exposure was positively associated with fractional exhaled nitric oxide z-score. The findings of this study suggest that phthalate inhalation exposure may substantially affect various health metrics in children, including body mass index, waist and hip circumference, and blood pressure, and increase the risk of respiratory tract inflammation.
- Published
- 2024
- Full Text
- View/download PDF
35. High-Resolution Nitrogen Dioxide Measurements from an Airborne Fiber Imaging Spectrometer over Tangshan, China.
- Author
-
Zhang, Xiaoli, Xi, Liang, Zhou, Haijin, Wang, Wei, Chang, Zhen, Si, Fuqi, and Wang, Yu
- Subjects
- *
NITROGEN dioxide , *SPECTROMETERS , *TRACE gases , *FIBERS , *AIRBORNE-based remote sensing , *LIGHT absorption , *REMOTE sensing - Abstract
The pollution caused by nitrogen dioxide is a major environmental problem in China. This study introduces a new type of atmospheric trace gas remote-sensing instrument, an airborne fiber imaging spectrometer. This spectrometer has a spectral range of 300–410 nm and works in push-broom mode with a 30° field of view on a flight path. Flight experiments were conducted on 30 December 2022 and 5 January 2023, covering heavily polluted areas east of Beijing and Tangshan. This equipment obtained the density distribution of NO2 over the flight area. The results showed that pollution was mainly concentrated in the Caofeidian area and at the power station in the north, and the main source of pollution was anthropogenic. Satellite and airborne data near the pollution points were compared, and the two datasets showed a positive correlation with a correlation coefficient of 0.78 and 0.7, on the two days, respectively. This study demonstrates the capability of an airborne fiber imaging spectrometer for NO2 regional emission remote sensing and identifying the pollution points. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
36. Remote sensing and spectroscopy of lichens.
- Author
-
Rautiainen, Miina, Kuusinen, Nea, and Majasalmi, Titta
- Subjects
- *
ENERGY budget (Geophysics) , *LICHENS , *HABITATS , *BIOINDICATORS , *POLLUTION monitoring , *REMOTE sensing - Abstract
Lichens are combinations of two symbiotic organisms, a green alga or cyanobacterium and a fungus. They grow in nearly all terrestrial ecosystems and survive in habitats, which are very dry or cold, or too poor in nutrients to maintain vegetation growth. Because lichens grow on visible surfaces and exhibit spectral properties, which are clearly different from, for example, vegetation, it is possible to distinguish them in remote sensing data. In this first systematic review article on remote sensing of lichens, we analyze and summarize which lichen species or genera, and in which habitats and geographical regions, have been remotely sensed, and which remote sensing or spectroscopic technologies have been used. We found that laboratory or in situ measured spectra of over 70 lichen species have been reported to date. We show that studies on remote sensing of lichens fall under seven broad themes: (1) collection of lichen spectra for quantification of lichen species or characteristics, (2) pollution monitoring with lichens as ecological indicators, (3) geological and lithological mapping, (4) desert and dryland monitoring, (5) animal habitat monitoring, (6) land cover or vegetation mapping, and (7) surface energy budget modeling. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
37. Challenges and Limitations of Remote Sensing Applications in Northern Peatlands: Present and Future Prospects.
- Author
-
Abdelmajeed, Abdallah Yussuf Ali and Juszczak, Radosław
- Subjects
- *
REMOTE sensing , *DRONE aircraft , *THEMATIC mapper satellite , *PEATLANDS , *HYDROLOGY - Abstract
This systematic literature review (SLR) provides a comprehensive overview of remote sensing (RS) applications in northern peatlands from 2017 to 2022, utilising various platforms, including in situ, UAV, airborne, and satellite technologies. It addresses the challenges and limitations presented by the sophisticated nature of northern peatland ecosystems. This SLR reveals an in-creased focus on mapping, monitoring, and hydrology but identifies noticeable gaps in peatland degradation research. Despite the benefits of remote sensing, such as extensive spatial coverage and consistent monitoring, challenges persist, including high costs, underexplored areas, and limitations in hyperspectral data application. Fusing remote sensing data with on-site research offers new insights for regional peatland studies. However, challenges arise from issues like the cost of high-resolution data, coverage limitations, and inadequate field validation data in remote areas. This review suggests refining methodologies, validating with high-resolution data, and addressing these limitations for future research. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
38. A Mathematical Model for Evaluating the Risk of Airborne Infection Among Bus Passengers Using Ventilation Systems.
- Author
-
Sooknum, Jenjira and Pochai, Nopparat
- Subjects
- *
AIRBORNE infection , *BUS occupants , *VENTILATION , *MATHEMATICAL models , *FINITE difference method , *BUSES , *BUS transportation - Abstract
Carbon dioxide from human breath contributes significantly to airborne diseases. Breathing can expose us to usually dangerous airborne infections, which rapidly spread. By using a bus, there is a chance of contracting an infection. This study takes into account a mathematical model of airborne infection caused by human breath. The purpose of this research is to evaluate the probability that passengers in a bus with ventilation systems may well get an airborne infection. The model can be divided into five submodels, such as an exhaled air concentration measurement model for a bus with a variable number of passengers, the volume fraction of exhaled air model, the concentration of airborne infectious particles model, the number of airborne infectious particles model, and the risk of airborne infection model. The model's solution might be used to determine the probability that susceptible people will get an airborne infection. An explicit forward-time centered-space finite difference method is used to approximate the solution. In order to reduce the risk of airborne infection and improve ventilation, the provided mathematical models were used to assess the risk of airborne infection among bus passengers using ventilation systems. Better air quality control that balances the number of passengers allowed to travel on a bus will be among the ventilation's main advantages. [ABSTRACT FROM AUTHOR]
- Published
- 2024
39. Design and testing of a sew-free origami mask for improvised respiratory protection.
- Author
-
Realmuto, Jonathan, Kleinman, Michael T, Sanger, Terence, Lawler, Michael J, and Smith, James N
- Subjects
- *
RESPIRATORY protective devices , *MEDICAL masks , *ORIGAMI , *PRESSURE drop (Fluid dynamics) , *BREATHING apparatus , *FILTERS & filtration , *TEST design - Abstract
Respiratory aerosols with diameters smaller than 100 μ m have been confirmed as important vectors for the spread of diseases such as SARS-CoV-2. While disposable and cloth masks afford some protection, they are typically inefficient at filtering these aerosols and require specialized fabrication devices to produce. We describe a fabrication technique that makes use of a folding procedure (origami) to transform any filtration material into a mask. These origami masks can be fabricated by non-experts at minimal cost and effort, provide adequate filtration efficiencies, and are easily scaled to different facial sizes. Using a mannequin fit test simulator, we demonstrate that these masks can provide filtration efficiencies of over 90% while simultaneously providing greater comfort as demonstrated by pressure drops of <20 Pa. We also quantify mask leakage by measuring the variations in filtration efficiency and pressure drop when masks are sealed to the mannequin face compared to when the mask is unsealed but positioned to achieve the best fit. While leakage generally trended with pressure drop, some of the best performing mask media achieved <10% reduction in filtration efficiency due to leakage. Because this mask can provide high filtration efficiencies at low pressure drop compared to commercial alternatives, it is likely to promote greater mask wearing tolerance and acceptance. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
40. Assessment of aboveground carbon mass in a Mediterranean downy oak ecosystem using airborne lidar and NASA GEDI measurements.
- Author
-
Chazette, Maëlie, Chazette, Patrick, Reiter, Ilja M., Shang, Xiaoxia, Totems, Julien, Orts, Jean-Philippe, Xueref-Remy, Irène, and Montes, Nicolas
- Subjects
OAK ,LIDAR ,CLIMATE change models ,FOREST biomass ,ECOLOGICAL impact ,FOREST density ,ECOSYSTEM dynamics ,TREE height - Abstract
The forest system is the main carbon sink after the oceans. However, due to climate change, an alarming number of tree species of the Northern Hemisphere are at risk of migrating northwards or becoming extinct. This is the case of the downy oak (Quercus pubescens), one of the main species making up the forests close to the Mediterranean Sea in France. Our aim is to retrieve aboveground carbon (AGC) and underground root carbon (UGC) stocks of the downy oak forest at Observatoire de Haute Provence (OHP), located about 80 km north of Marseille, in order to provide a baseline against which to assess the effect of climate change on this model species. The study presented here is based on airborne lidar observations gathered in May 2012 and field measurements from 2012, 2018 and 2023 in the OHP forest. The OHP forest consists of ~75 % downy oak, which is highly sensitive to global warming. Field measurements indicate minimal changes in tree growth and density between 2012 and 2023, and that its carbon storage efficiency remains stationary. As retrieved by lidar measurements, tree top heights (TTHs) are mostly between 5 and 12 m, with an uncertainty of around 1 m. The slow evolution of trees at the OHP site makes it appropriate to use lidar data recorded in 2012 to assess the carbon stock trapped in current forest biomass. By coupling allometric laws established from field measurements with lidar observations, we show that the quantities of carbon trapped in aboveground biomass are double those trapped in the root system. Over an area of ~24 ha, mean values of 15±14 tC ha
-1 are assessed for the aerial biomass, against 8-10±3-7 tC ha-1 for the roots of diameter larger than 1 cm for low and high assessments, respectively. These values depend heavily on the height of the sampled trees themselves, as well as on their location on the OHP plateau (smaller trees, 5-6 m) or on the slope (tallest trees, 10-12 m). Using a Monte Carlo approach, the relative uncertainties in AGC have been calculated to be of the order of 17 % and 11 % for trees 5-6 m and 10-12 m tall, respectively. For UGC, the relative uncertainties were calculated as 8 and 5 % for the same tree heights, but the assumptions on the allometric model are associated with biases that can easily reach 100 %. Although the surface footprints are different, we show that there is a reasonable agreement between our airborne lidar measurements and the level 2B (TTH) and (aboveground biomass) operational products of the Global Ecosystem Dynamics Investigation mission on the International Space Station for data acquired between 2019 and 2022. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
41. Hawaiian Volcanic Ash, an Airborne Fomite for Nontuberculous Mycobacteria.
- Author
-
Dawrs, Stephanie N., Virdi, Ravleen, Norton, Grant J., Elias, Tamar, Hasan, Nabeeh A., Robinson, Schuyler, Matriz, Jobel, Epperson, L. Elaine, Glickman, Cody M., Beagle, Sean, Crooks, James L., Nelson, Stephen T., Chan, Edward D., Damby, David E., Strong, Michael, and Honda, Jennifer R.
- Subjects
VOLCANIC ash, tuff, etc. ,MYCOBACTERIA ,MYCOBACTERIUM avium ,VOLCANIC eruptions ,EXPLOSIVE volcanic eruptions ,WHOLE genome sequencing ,OBSIDIAN - Abstract
Nontuberculous mycobacteria (NTM) are environmentally acquired opportunistic pathogens that can cause chronic lung disease. Within the U.S., Hawai'i shows the highest prevalence rates of NTM lung infections. Here, we investigated a potential role for active volcanism at the Kīlauea Volcano located on Hawai'i Island in promoting NTM growth and diversity. We recovered NTM that are known to cause lung disease from plumbing biofilms and soils collected from the Kīlauea environment. We also discovered viable Mycobacterium avium, Mycobacterium abscessus, and Mycobacterium intracellulare subsp. chimaera on volcanic ash collected during the 2018 Kīlauea eruption. Analysis of soil samples showed that NTM prevalence is positively associated with bulk content of phosphorus, sulfur, and total organic carbon. In growth assays, we showed that phosphorus utilization is essential for proliferation of Kīlauea‐derived NTM, and demonstrate that NTM cultured with volcanic ash adhere to ash surfaces and remain viable. Ambient dust collected on O'ahu concurrent with the 2018 eruption contained abundant fresh volcanic glass, suggestive of inter‐island ash transport. Phylogenomic analyses using whole genome sequencing revealed that Kīlauea‐derived NTM are genetically similar to respiratory isolates identified on other Hawaiian Islands. Consequently, we posit that volcanic eruptions could redistribute environmental microorganisms over large scales. While additional studies are needed to confirm a direct role of ash in NTM dispersal, our results suggest that volcanic particulates harbor and can redistribute NTM and should therefore be studied as a fomite for these burgeoning, environmentally acquired respiratory infections. Plain Language Summary: Nontuberculous mycobacteria (NTM) can cause environmentally acquired lung infections in susceptible individuals. While NTM infections are linked to household exposures, there are likely non‐household routes of acquisition. Hawai'i is a geographic hotspot for NTM lung disease, but the island‐specific environmental niches for NTM remain poorly understood. Thus, a greater knowledge of where susceptible individuals acquire their infections is an important public health endeavor that may lead to actions to mitigate potential sources of NTM exposures. In the current work, we show that particulate matter collected from Kīlauea Volcano on Hawai'i Island harbors Mycobacterium avium, Mycobacterium abscessus, and Mycobacterium intracellulare subsp. chimaera. Microbiologic, environmental, and NTM genetic data demonstrate that volcanic ash may act as a novel vehicle for the dispersal of clinically relevant NTM. Key Points: Long‐range transport of hitch‐hiking infectious agents has never been reported for volcanic eruptions globallyAsh recovered from the 2018 Kīlauea Volcano eruption harbors species of nontuberculous mycobacteria (NTM) known to cause lung diseaseGenomic evaluation reveals Kīlauea‐derived NTM are genetically similar to respiratory isolates identified on other Hawaiian Islands [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
42. Risk assessment of airborne virus transmission in an intensive care unit due to single and sequential coughing.
- Author
-
Kusuluri, Rajendra, Mirikar, Dnyanesh, Palanivel, Silambarasan, and Arumuru, Venugopal
- Subjects
AIRBORNE infection ,INTENSIVE care units ,COUGH ,VACCINE manufacturing ,RISK assessment ,ENERGY conservation - Abstract
The virus causing COVID‐19 has constantly been mutating into new variants. Some of them are more transmissive and resistant to antibiotics. The current research article aims to examine the airborne transmission of the virus expelled by coughing action in a typical intensive care unit. Both single and sequential coughing actions have been considered to get closer to practical scenarios. The objective is to assess the effectiveness of air change per hour (ACH) on the risk of infection to a healthcare person and how the air change rate influences the dispersion of droplets. Such a study is seldom reported and has significant relevance. A total of four cases were analyzed, of which two were of sequential cough. When the ACH is changed from 6 to 12, the average particle residence time is reduced by ∼7 s. It is found that the risk of infection in the case of sequential cough will be relatively low compared to a single cough if the outlet of the indoor environment is placed above the patient's head. This arrangement also eliminates the requirement of higher ACH, which has significance from an energy conservation perspective. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
43. Airborne microplastic/nanoplastic research: a comprehensive Web of Science (WoS) data-driven bibliometric analysis.
- Author
-
Tan, Huiyi, Mong, Guo Ren, Wong, Syie Luing, Wong, Keng Yinn, Sheng, Desmond Daniel Chin Vui, Nyakuma, Bemgba Bevan, Othman, Mohd Hafiz Dzarfan, Kek, Hong Yee, Razis, Ahmad Faizal Abdull, Wahab, Nur Haliza Abdul, Wahab, Roswanira Abdul, Lee, Kee Quen, Chiong, Meng Choung, and Lee, Chia Hau
- Subjects
BIBLIOMETRICS ,INTERNET research ,WEB databases ,SCIENCE databases ,RESEARCH & development ,LANDSCAPE assessment - Abstract
This paper presents the landscape of research on airborne microplastics and nanoplastics (MPs/NPs) according to the bibliometric analysis of 147 documents issued between 2015 and 2021, extracted from the Web of Science database. The publications on airborne MPs/NPs have increased rapidly from 2015 onwards, which is largely due to the existence of funding support. Science of the Total Environment is one of the prominent journals in publishing related papers. China, England, the USA, and European Countries have produced a significant output of airborne MP/NP research works, which is associated with the availability of funding agencies regionally or nationally. The research hotspot on the topic ranges from the transport of airborne MPs/NPs to their deposition in the terrestrial or aquatic environments, along with the contamination of samples by indoor MPs/NPs. Most of the publications are either research or review papers related to MPs/NPs. It is crucial to share the understanding of global plastic pollution and its unfavorable effects on humankind by promoting awareness of the existence and impact of MPs/NPs. Funding agencies are vital in boosting the research development of airborne MPs/NPs. Some countries that are lacking funding support were able to publish research findings related to the field of interest, however, with lesser research output. Without sufficient fundings, some impactful publications may not be able to carry a substantial impact in sharing the findings and discoveries with the mass public. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
44. Patient‐worn endoscopy mask to protect against viral transmission
- Author
-
Vahabzadeh‐Hagh, Andrew M, Patel, Shiv H, Stramiello, Joshua A, and Weissbrod, Philip A
- Subjects
Biomedical and Clinical Sciences ,Clinical Sciences ,Health Sciences ,Good Health and Well Being ,airborne ,COVID-19 ,droplet ,endoscopic-mask ,flu season ,personal protective equipment ,COVID‐19 ,endoscopic‐mask - Abstract
ObjectivesTo design and evaluate patient-worn personal protective equipment (PPE) that allows providers to perform endoscopy while protecting against droplet and airborne disease transmission.Study designSingle subject study.MethodsMask efficacy was evaluated using a cough simulator that sprays dye visible under ultra-violet light. User-testing was performed on an airway trainer mannequin where each subject performed the endoscopy with and without the mask in random orders. Their time to completion and number of attempts before successful completion were recorded, and each subject was asked to fill out a NASA Task Load Index (TLX) form with respect to their experience.ResultsThe mask has a filtration efficiency of 97.31% and eliminated any expelled particles with the cough simulator. Without the mask, a simulated cough is visualized as it progresses away from the cough origin. Subjects who performed trans-nasal endoscopy spent 27.8 ± 8.0 s to visualize the vocal cords for the no mask condition and 28.7 ± 13.6 s for the mask condition (mean ± SD, p > .05). There was no statistically significant difference found in the mental demand, physical demand, temporal demand, performance, effort, and frustration of endoscopy under the no mask and mask conditions (all p > .05).ConclusionThe designed PPE provides an effective barrier for viral droplet and airborne transmission while allowing the ability to perform endoscopy with ease.Level of evidence3 Laryngoscope, 2021.
- Published
- 2022
45. Indoor aerosol science aspects of SARS‐CoV‐2 transmission
- Author
-
Nazaroff, William W
- Subjects
Biodefense ,Emerging Infectious Diseases ,Vaccine Related ,Prevention ,Lung ,Aetiology ,2.2 Factors relating to the physical environment ,Good Health and Well Being ,Aerosols ,Air Microbiology ,Air Pollution ,Indoor ,COVID-19 ,Humans ,SARS-CoV-2 ,Ventilation ,airborne ,infectious disease ,intake fraction ,particle ,virus ,Earth Sciences ,Engineering ,Medical and Health Sciences ,Building & Construction - Abstract
Knowledge about person-to-person transmission of SARS-CoV-2 is reviewed, emphasizing three components: emission of virus-containing particles and drops from infectious persons; transport and fate of such emissions indoors; and inhalation of viral particles by susceptible persons. Emissions are usefully clustered into three groups: small particles (diameter 0.1-5 µm), large particles (5-100 µm), and ballistic drops (>100 µm). Speaking generates particles and drops across the size spectrum. Small particles are removed from indoor air at room scale by ventilation, filtration, and deposition; large particles mainly deposit onto indoor surfaces. Proximate exposure enhancements are associated with large particles with contributions from ballistic drops. Masking and social distancing are effective in mitigating transmission from proximate exposures. At room scale, masking, ventilation, and filtration can contribute to limit exposures. Important information gaps prevent a quantitative reconciliation of the high overall global spread of COVID-19 with known transmission pathways. Available information supports several findings with moderate-to-high confidence: transmission occurs predominantly indoors; inhalation of airborne particles (up to 50 µm in diameter) contributes substantially to viral spread; transmission occurs in near proximity and at room scale; speaking is a major source of airborne SARS-CoV-2 virus; and emissions can occur without strong illness symptoms.
- Published
- 2022
46. HYPERSPECTRAL IMAGING TECHNOLOGY FOR THE DETECTION OF METHANE EMISSIONS.
- Author
-
Gagnon, Jean-Philippe and Ishchenko, Dmitri
- Subjects
- *
GREENHOUSE gas mitigation , *VOLATILE organic compounds , *INFRARED technology , *AIRPLANES , *GREENHOUSE gases , *FUGITIVE emissions - Abstract
This article discusses the use of hyperspectral imaging technology for the detection of methane emissions. Methane is a potent greenhouse gas that contributes to climate change, and reducing its emissions can have positive impacts. The article highlights that traditional gas sniffing techniques and optical gas imagers have limitations in accurately identifying and quantifying methane emissions. Aerial surveys using hyperspectral cameras, such as the Hyper-Cam Airborne Mini, provide a cost-effective solution for detecting methane leaks in the oil and gas industry. This technology can also detect emissions of other gaseous substances. [Extracted from the article]
- Published
- 2024
47. Challenges Facing the Use of Remote Sensing Technologies in the Construction Industry: A Review
- Author
-
Abdulmohsen S. Almohsen
- Subjects
remote sensing ,LiDAR ,resolution ,satellite ,airborne ,spatial ,Building construction ,TH1-9745 - Abstract
Remote sensing is essential in construction management by providing valuable information and insights throughout the project lifecycle. Due to the rapid advancement of remote sensing technologies, their use has been increasingly adopted in the architecture, engineering, and construction industries. This review paper aims to advance the understanding, knowledge base, and practical implementation of remote sensing technologies in the construction industry. It may help support the development of robust methodologies, address challenges, and pave the way for the effective integration of remote sensing into construction management processes. This paper presents the results of a comprehensive literature review, focusing on the challenges faced in using remote sensing technologies in construction management. One hundred and seventeen papers were collected from eight relevant journals, indexed in Web of Science, and then categorized by challenge type. The results of 44 exemplary studies were reported in the three types of remote sensing platforms (satellite, airborne, and ground-based remote sensing). The paper provides construction professionals with a deeper understanding of remote sensing technologies and their applications in construction management. The challenges of using remote sensing in construction were collected and classified into eleven challenges. According to the number of collected documents, the critical challenges were shadow, spatial, and temporal resolution issues. The findings emphasize the use of unmanned airborne systems (UASs) and satellite remote sensing, which have become increasingly common and valuable for tasks such as preconstruction planning, progress tracking, safety monitoring, and environmental management. This knowledge allows for informed decision-making regarding integrating remote sensing into construction projects, leading to more efficient and practical project planning, design, and execution.
- Published
- 2024
- Full Text
- View/download PDF
48. Design of an Airborne Low-Light Imaging System Based on Multichannel Optical Butting
- Author
-
Jianwei Peng, Hongtao Yang, Yangjie Lei, Wanrong Yu, Weining Chen, and Guangdong Zhang
- Subjects
airborne ,optical butting ,low light ,imaging system ,swath width ,Applied optics. Photonics ,TA1501-1820 - Abstract
For the purpose of achieving long-range, high-resolution, and ultra-wide-swath airborne earth imaging at extremely low-light levels (0.01 Lux), a low-light imaging system built on multi-detector optical butting was researched. Having decomposed the system’s specifications and verified its low-light imaging capability, we proposed to employ an optical system with a large relative aperture and low distortion and achieve imaging through the field-of-view (FOV) butting facilitated by eight 1080P high-sensitivity scientific complementary metal-oxide semiconductor (SCMOS) detectors. This paper elaborates on the design concept of the mechanical configuration of the imaging system; studies the calculation method of the structural parameters of the reflection prism; provides mathematical expressions for geometric parameters, such as the length and width of the splicing prism; and designs in detail the splicing structure of six reflection prisms for eight-channel beam splitting. Based on the design and computational results, a high-resolution, wide-swath imaging system for an ambient illuminance of 0.01 Lux was developed. Exhibiting a ground sampling distance (GSD) of 0.5 m (at a flight height of 5 km), this low-light imaging system keeps the FOV overlap ratio between adjacent detectors below 3% and boasts an effective image resolution of 4222 × 3782. The results from flight testing revealed that the proposed imaging system is capable of generating wide-swath, high-contrast resolution imagery under airborne and low-light conditions. As such, the way the system is prepared can serve as a reference point for the development of airborne low-light imaging devices.
- Published
- 2024
- Full Text
- View/download PDF
49. Instrument Design and In-Flight Performance of an Airborne Terahertz Ice Cloud Imager
- Author
-
Rongchuan Lv, Wenyu Gao, Feng Luo, Yinan Li, Zheng He, Congcong Wang, Yan Zhang, Chengzhen Zhang, Daozhong Sun, Jian Shang, Fangli Dou, and Xiaodong Wang
- Subjects
ice cloud imager ,terahertz ,airborne ,183–664 GHz ,Science - Abstract
The Airborne Terahertz Ice Cloud Imager (ATICI) is an airborne demonstration prototype of an ice cloud imager (ICI), which will be launched on the next generation of Fengyun satellites and plays an important role in heavy precipitation detection, typhoon, and medium-to-short-term meteorological/ocean forecasting. At present, it has 13 frequency channels covering 183–664 GHz, which are sensitive to scattering by cloud ice. This paper provides an overview of ATICI and proposes a receiving front-end design scheme using a planar mirror and a quasi-optical feed network which improves the main beam efficiency of each frequency band, with measured values better than 95.5%. It can detect factors such as ice particle size, ice water path, and ice water content in clouds by rotating the circular scanning of the antenna feed system. A high-sensitivity receiver system has been developed and tested for verification. The flight verification results show that the quasi-optical feed network subsystem works well and performs stably under vibration and temperature changes. The system sensitivity is better than 1.5 K, and the domestically produced high-frequency receiver has stable performance, which can meet the conditions of satellite applications. The ATICI performs well and meets expectations, verifying the feasibility of the Fengyun-5 ICI payload.
- Published
- 2024
- Full Text
- View/download PDF
50. Application of a Coupled CFD-Multizone Code on Ventilation and Filtration Analysis for Covid-19 Airborne Infection Control in a Small Office
- Author
-
Barbosa, Bruno Perazzo Pedroso, Förstner, Ulrich, Series Editor, Rulkens, Wim H., Series Editor, Wang, Liangzhu Leon, editor, Ge, Hua, editor, Zhai, Zhiqiang John, editor, Qi, Dahai, editor, Ouf, Mohamed, editor, Sun, Chanjuan, editor, and Wang, Dengjia, editor
- Published
- 2023
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.