Vapor Products Research Articles

Spatiotemporal Heterogeneity of Precipitable Water Diurnal Variation over the Tibetan Plateau Based on a Refined 2D Water Vapor Reconstruction

Atmospheric water vapor is a critical factor influencing rainfall, snowfall, and avalanche occurrences, with its diurnal variations providing key insights into such phenomena. However, in high-altitude mountainous areas, the spatial and temporal resolution of water vapor products is insufficient to depict their diurnal variation characteristics. This study aimed to refine the understanding of diurnal Precipitable Water Vapor (PWV) variations using the ANUSPLIN to obtain a two-dimensional water vapor field with a resolution of 0.1° × 0.1° during the monsoon period from 2007 to 2015, which was verified based on ground-based GPS water vapor observations. The findings reveal that incorporating China Meteorological Forcing Data (CMFD) greatly enhances the diurnal variation patterns of PWV, resulting in the appearance of extreme values of PWV daily variation about three hours later than the MERRA reanalysis. In the southern Tibetan Plateau (TP), the diurnal variation of PWV is closer to GPS PWV in terms of amplitude and phase. Spatially, PWV variations are weaker in the central TP but stronger in other regions, particularly during the mid-monsoon period (July–August). Temporally, the central TP experiences maximum PWV from nighttime to early morning (18:00–4:00 UTC), while the surrounding southern and northern areas peak from afternoon to evening (8:00–12:00 UTC), approximately three hours earlier than precipitation peaks. Temporally, the central Tibetan Plateau experiences maximum PWV from nighttime to early morning (18:00–4:00 UTC), while the surrounding southern and northern areas peak from afternoon to evening (8:00–12:00 UTC), approximately three hours earlier than precipitation peaks.

China Aerosol Raman Lidar Network (CARLNET)—Part I: Water Vapor Raman Channel Calibration and Quality Control

Water vapor is an active trace component in the troposphere and has a significant impact on meteorology and the atmospheric environment. In order to meet demands for high-precision water vapor and aerosol observations for numerical weather prediction (NWP), the China Meteorological Administration (CMA) deployed 49 Raman aerosol lidar systems and established the first Raman–Mie scattering lidar network in China (CARLNET) for routine measurements. In this paper, we focus on the water vapor measurement capabilities of the CARLNET. The uncertainty of the water vapor Raman channel calibration coefficient (Cw) is determined using an error propagation formula. The theoretical relationship between the uncertainty of the calibration coefficient and the water vapor mixing ratio (WVMR) is constructed based on least squares fitting. Based on the distribution of lidar in regions with different humidity conditions, the method of real-time calibration and quality control based on radiosonde data is established for the first time. Based on the uncertainty requirements of the World Meteorological Organization for water vapor in data assimilation, the calibration and quality control thresholds of the WVMR in regions with different humidity conditions are determined by fitting real-time lidar and radiosonde data. Lastly, based on the radiosonde results, the calibration algorithm established in this study is used to calibrate CARLNET data from October to December 2023. Compared with traditional calibration results, the results show that the stability and detection accuracy of the CARLNET significantly improved after calibration in regions with different humidity conditions. The deviation of the Cw decreased from 12.84~18.47% to 5.41~11.54%. The inversion error of the WVMR compared to radiosonde decreased from 1.05~0.46 g/kg to 0.82~0.34 g/kg. The reliability of the improved calibration algorithm and the CARLNET’s performance have been verified, enabling them to provide high-precision water vapor products for NWP.

Evaluation and Adjustment of Precipitable Water Vapor Products from FY-4A Using Radiosonde and GNSS Data from China

The geostationary meteorological satellite Fengyun-4A (FY-4A) has rapidly advanced, generating abundant high spatiotemporal resolution atmospheric precipitable water vapor (PWV) products. However, remote sensing satellites are vulnerable to weather conditions, and these latest operational PWV products still require systematic validation. This study presents a comprehensive evaluation of FY-4A PWV products by separately using PWV data retrieved from radiosondes (RS) and the Global Navigation Satellite System (GNSS) from 2019 to 2022 in China and the surrounding regions. The overall results indicate a significant consistency between FY-4A PWV and RS PWV as well as GNSS PWV, with mean biases of 7.21 mm and −8.85 mm, and root mean square errors (RMSEs) of 7.03 mm and 3.76 mm, respectively. In terms of spatial variability, the significant differences in mean bias and RMSE were 6.50 mm and 2.60 mm between FY-4A PWV and RS PWV in the northern and southern subregions, respectively, and 5.36 mm and 1.73 mm between FY-4A PWV and GNSS PWV in the northwestern and southern subregions, respectively. The RMSE of FY-4A PWV generally increases with decreasing latitude, and the bias is predominantly negative, indicating an underestimation of water vapor. Regarding temporal differences, both the monthly and daily biases and RMSEs of FY-4A PWV are significantly higher in summer than in winter, with daily precision metrics in summer displaying pronounced peaks and irregular fluctuations. The classic seasonal, regional adjustment model effectively reduced FY-4A PWV deviations across all regions, especially in the NWC subregion with low water vapor distribution. In summary, the accuracy metrics of FY-4A PWV show distinct spatiotemporal variations compared to RS PWV and GNSS PWV, and these variations should be considered to fully realize the potential of multi-source water vapor applications.

Combining low- and high-frequency microwave radiometer measurements from the MOSAiC expedition for enhanced water vapour products

Abstract. In the central Arctic, high-quality water vapour observations are sparse due to the low density of meteorological stations and uncertainties in satellite remote sensing. Different reanalyses also disagree on the amount of water vapour in the central Arctic. The Multidisciplinary drifting Observatory for the Study of the Arctic Climate (MOSAiC) expedition provides comprehensive observations that are suitable for evaluating satellite products and reanalyses. Radiosonde observations provide high-quality water vapour estimates with a high vertical but a low temporal resolution. Observations from the microwave radiometers (MWRs) on board the research vessel Polarstern complement these observations through high temporal resolution. In this study, we demonstrate the high accuracy of the combination of the two MWRs HATPRO (Humidity and Temperature Profiler) and MiRAC-P (Microwave Radiometer for Arctic Clouds – Passive). For this purpose, we developed new retrievals of integrated water vapour (IWV) and profiles of specific humidity and temperature using a neural network approach, including observations from both HATPRO and MiRAC-P to utilize their different water vapour sensitivity. The retrievals were trained with the European Centre for Medium-Range Weather Forecasts (ECMWF) reanalysis version 5 (ERA5) and synthetic MWR observations simulated with the Passive and Active Microwave radiative TRAnsfer tool (PAMTRA). We applied the retrievals to synthetic and real observations and evaluated them with ERA5 and radiosondes launched during MOSAiC, respectively. To assess the benefit of the combination of HATPRO and MiRAC-P compared to single MWR retrievals, we compared the errors with respect to MOSAiC radiosondes and computed the vertical information content of the specific humidity profiles. The root mean squared error (RMSE) of IWV was reduced by up to 15 %. Specific humidity biases and RMSE were reduced by up to 75 % and 50 %, respectively. The vertical information content of specific humidity could be increased from 1.7 to 2.4 degrees of freedom. We also computed relative humidity from the retrieved temperature and specific humidity profiles and found that RMSE was reduced from 45 % to 15 %. Finally, we show a case study demonstrating the enhanced humidity profiling capabilities compared to the standard HATPRO-based retrievals. The vertical resolution of the retrieved specific humidity profiles is still low compared to radiosondes, but the case study revealed the potential to resolve major humidity inversions. To what degree the MWR combination detects humidity inversions, also compared to satellites and reanalyses, will be part of future work.

Plasma-Fluid Energy Transfers in Plasma Assisted Ignition

ABSTRACT A three-dimensional model of plasma-fluid coupling is developed, including the Navier-Stokes, the drift-diffusion, and the radiative transfer equations, to investigate the energy transfers between plasma and fluid in repetitive-pulsed discharge ignition. A modal decomposition of the energy transfer is performed to determine the contributions of plasma to the mechanical coupling and pressure losses during ignition. The detailed model is validated against experiments and compared against a well-known empirical approximation. The main findings are that the modal coupling is dependent on the geometry of the electrodes and flat electrodes provide the strongest mechanical transfer into the acoustic modes. Uniform flow conditions decrease the extent of the mechanical coupling due to the decreased pressure velocity correlations in shear flows. Water vapor production reduces the entropic mode of the energy coupling.

Marketing for Sensa: A novel "zero nicotine vapor product" from a major tobacco company.

On July 1, 2024, RJ Reynolds Vapor Company (RJRVC) introduced Sensa, the first disposable "zero nicotine vapor product" from a major tobacco company. Sensa sold more than 100,000 units as of September 10, 2024 and has been marketed through several channels. Direct-mail and magazine ads appeal to consumers' senses (e.g., "awaken your senses") and showcase Sensa's six flavor options: Berry Fusion, Berry Watermelon Fusion, Blueberry Frost, Mint Frost, Passionfruit Frost, and Watermelon Frost. Our chemical characterization of all Sensa flavors (except Berry Watermelon Fusion) found neotame (a potent artificial sweetener) and WS-23 (a synthetic coolant) in all samples, while all "Frost" flavors tested contained another synthetic coolant, WS-3. Although RJRVC states that Sensa is for "adult tobacco and vapor consumers," Sensa's resemblance to popular disposable vaping devices and youth-appealing flavors raise concerns about Sensa's appeal to young people, and limited regulations for "zero nicotine" products introduce uncertainty about product safety.

3D Surface Velocity Field Inferred from SAR Interferometry: Cerro Prieto Step-Over, Mexico, Case Study

The Cerro Prieto basin, a tectonically active pull-apart basin, hosts significant geothermal resources currently being exploited in the Cerro Prieto Geothermal Field (CPGF). Consequently, natural tectonic processes and anthropogenic activities contribute to three-dimensional surface displacements in this pull-apart basin. Here, we obtained the Cerro Prieto Step-Over 3D surface velocity field (3DSVF) by accomplishing a weighted least square algorithm inversion from geometrically quasi-orthogonal airborne UAVSAR and RADARSAT-2, Sentinel 1A satellite Synthetic Aperture-Radar (SAR) imagery collected from 2012 to 2016. The 3DSVF results show a vertical rate of 150 mm/yr and 40 mm/yr for the horizontal rate, where for the first time, the north component displacement is achieved by using only the Interferometric SAR time series in the CPGF. Data integration and validation between the 3DSVF and ground-based measurements such as continuous GPS time series and precise leveling data were achieved. Correlating the findings with recent geothermal energy production revealed a subsidence rate slowdown that aligns with the CPGF’s annual vapor production.

Adult Caretaker Engagement and School Connectedness and Association with Substance Use, Indicators of Emotional Well-Being and Suicide Risk, and Experiences with Violence Among American Indian or Alaska Native High School Students - Youth Risk Behavior Survey, United States, 2023.

The strength of American Indian and Alaska Native (AI/AN) communities comes from generations of Indigenous traditions, language, culture, and knowledge. These strengths have been challenged by a complex set of systemic, structural, and social factors related to historical and intergenerational trauma that affects the health of AI/AN communities. Furthermore, AI/AN population health data often are inaccurate because of analytic coding practices that do not account for multiracial and ethnic AI/AN identification and inadequate because of statistical suppression. The 2023 national Youth Risk Behavior Survey included a supplemental sample of AI/AN high school students. Coding of race and ethnicity was inclusive of all AI/AN students, even if they also identified as another race or as Hispanic or Latino, providing comprehensive data on health behaviors and experiences among AI/AN high school students nationwide. Adult caretaker engagement and school connectedness and their association with 13 health behaviors and experiences were examined, including five types of current substance use, four indicators of emotional well-being and suicide risk, and four types of violence. Pairwise t-tests and adjusted prevalence ratios from logistic regression models identified significant associations between exposure and outcome variables. Among AI/AN students, having an adult who always tried to meet their basic needs, high parental monitoring, and high school connectedness were associated with lower prevalence of certain measures of substance use, poor emotional well-being and suicide risk, and violence. Compared with non-AI/AN students, the prevalence of current electronic vapor product use, current marijuana use, attempted suicide, and experience of sexual violence was higher among AI/AN students.This report presents the most comprehensive, up-to-date data on substance use, indicators of emotional well-being and suicide risk, and experiences with violence among AI/AN high school students nationwide. The findings suggest the importance of engaged household adults and school connectedness in promoting emotional well-being and preventing substance use, suicide-related behavior, and experiences of violence among AI/AN students. Understanding the historical context and incorporating Indigenous knowledge when developing interventions focused on AI/AN youths are critical to ensure such interventions are successful in improving AI/AN health and well-being.

Effects of racial teasing on adolescent marijuana use and nicotine vaping: An analysis of the Virginia Youth Risk Behavior Surveillance System

BackgroundDespite adverse effects of tobacco and marijuana use on the adolescent brain, its use among youth remains high. Previous research shows associations between bullying and risks of substance use; less is known about racial teasing. This study examines associations of racial teasing, marijuana and/or electronic vapor products (EVP) use among adolescents, using 2021 Virginia Youth Risk Behavior Surveillance System (VYRBSS). MethodsVYRBSS is a self-reported survey which collects information on experiences with racial teasing and substance use. This analysis included 3,083 high school students ≥ 12 years old. Descriptive analysis and logistic regression models were performed for categorical variables. Multivariable models were adjusted for confounders. ResultsRacial teasing was associated with marijuana (AOR 1.89; CI 1.43–2.48) and EVP use (AOR 2.52; CI 1.91–3.31). Compared to Whites; Asians, Blacks, and Latinos were more likely to report racial teasing. Older heterosexual females reported higher use of marijuana and EVP. Blacks reported greater use of marijuana, whereas Whites were more likely to use EVP. EVP use was higher in females (AOR 1.73, CI 1.34–2.23), bisexual youth (AOR 1.68, CI 1.23, 2.30) and poor mental health (AOR 1.49, CI 1.16, 1.92). Marijuana use was associated with bisexuality (AOR 1.75, CI 1.28–2.39) and poor mental health (AOR 1.62, CI 1.27–2.07) as well. ConclusionsEvery effort should be made by public health professionals in Virginia to prevent racial teasing among adolescents because it increases the odds of substance use, particularly in older females, youth who identify as bisexual, and those reporting poor mental health.

Hydrodynamic solar-driven interfacial evaporation - Gone with the flow

Evaporation has been one of the most classic desalination processes on the Earth. When we try to use the power of water flow itself, the evaporation process can perform even better. Here, we report a hydrodynamic solar-driven interfacial evaporation process which water evaporation rate can achieve 6.58 kg·m-2·h-1 (over 100 times higher than natural evaporation). A waterwheel-structure solar interfacial evaporator was designed and assembled by printed filter papers. The evaporator can both rapidly distribute solution on the evaporation interface and be hydraulically driven to rotate continuously to improve the evaporation rate by water flow. The hydrodynamic solar-driven interfacial evaporation process successfully overcomes the problem of slow diffusion of water vapor, but also realizes the day-and-night operation of process and the self-cleaning of salt fouling. Apart from the application in solar desalination, the developed evaporator has great potentials in vapor production and salt recovery for industrial use.

Ultra-high solar steam generation based on regulated water management strategy in 3D biomass hydrogels inspired by the “binding effect” of cell walls

Facing the global challenge of water scarcity, solar-driven seawater desalination has been emerged as a green, non-polluting and sustainable technology, but the practical application of existing solar evaporators was hindered by their low evaporation efficiency and poor mechanical property. Inspired by the binding effect of cell walls, a novel and high-efficiency three-dimensional (3D) evaporator (CDs/CF/CS-LF) was constructed, in which loofah (LF) served as a natural 3D skeleton to support the hydrogel evaporator, resisted deformation, and created an efficient dual water supply mode with the chitosan (CS) hydrogel ensuring that the evaporator maintains high evaporation rate even under high salt environment. Additionally, the cellulose nanofibers (CF) filler enhanced the mechanical property of the hydrogel, ensuring shape stability under pressure impact, and carbon dots (CDs) facilitated the aggregation and cross-linking of chitosan chains through hydrogen bonds, further improving the mechanical property of the evaporator, while also enhancing the photothermal conversion capability of the 3D-CDs/CF/CS-LF evaporator as a photothermal material. The experimental results indicated that the 3D-CDs/CF/CS-LF evaporator could achieve an ultra-high solar vapor production rate of 8.08 kg m−2 h−1 under 1 sunlight intensity in 3.5 wt% NaCl solution. Outdoor seawater desalination experiments demonstrated the utility of 3D-CDs/CF/CS-LF evaporator for practical applications. This work provided a new approach for the improvement of CS-based evaporators and demonstrated their potential application in seawater desalination and purification.

Interface migration and alloying mechanism of Fe and P for ferrophosphorus alloy production during the carbothermic reduction of phosphorite

Ferrophosphorus (Fe–P alloy), a byproduct in the carbothermal reduction of phosphorite for yellow phosphorus production, has remarkable potential application as foundational precursors to prepare advanced catalysts and energy materials. However, the gas-solid-liquid equilibrium in the reduction smelting of phosphorite and hematite is intricate, and the reduction, volatilization, and alloying mechanisms of Fe and P at higher temperatures should be given close attention to optimize the production of yellow phosphorus vapor and Fe–P alloy. In this study, the reduction smelting behaviors of fluorapatite and hematite in the phosphorite ore were investigated. Carbothermic reduction reactions of Ca5(PO4)3F with and without Fe2O3 are calculated, establishing theoretical fundamentals. The phase and microstructure evolutions of Ca5(PO4)3F and Fe2O3 are researched. This work also emphasizes the interfacial element migration to clarify the reduction, volatilization, and alloying of Fe and P by considering the solid-solid interface of Ca5(PO4)3F–Fe2O3 and the gas-liquid interface of P2 vapor-metallic Fe.

Numerical modeling and analysis of nanofluids subcooled boiling in a horizontal circular tube

Subcooled flow boiling, characterized by large heat transfer coefficient (HTC), is widely encountered and of great significance in energy industry. To enhance its thermal efficiency for compact applications, nanofluids are employed by improving the thermophysical properties. This article numerically investigates nanofluids subcooled boiling in a horizontal tube under wide-range, multi-factor impacts, including Reynolds number of 40,000–50,000, nanoparticle type, that is, Al2O3, TiO2, Cu, and volume fraction of 1%–5%. The thermal equilibrium assumption and Eulerian multiphase model are utilized after numerical validations. Results indicate that the vapor volume fraction augments along the tube while nanoparticles reduce the vapor production during boiling. As for thermal and flow performance, nanofluids can enhance the HTC at the expense of a rising pressure drop. In the case of Al2O3/Water nanofluid, the maximum of HTC increases by 10.56%. In contrast, the pressure drop increases by 2.1 times when the Al2O3 concentration changes from 1% to 5%. The performance evaluation criterion (PEC) in this article always exceeds 1 for nanofluids, demonstrating that the heat transfer enhancement outweighs the pressure drop penalty, and the Al2O3/Water nanofluid show superior performance with PEC achieving 1.1. This work can provide support for a profound understanding and utilization of nanofluids subcooled boiling.

Health literacy and adolescents’ substance use behaviors and correlates: a scoping review

Abstract From 2011 to 2023, substance use increased by 23% worldwide. Given that substance use initiation is highest during adolescence, it is crucial to identify amenable correlates of substance use prevention [e.g. health literacy (HL)], which, if embedded in interventions, may improve uptake and outcomes. Hence, this study conducted a scoping review to answer the question: What is known from the existing literature about the relationship between HL and substance use correlates and behaviors in adolescents? Five electronic databases and the bibliography of review articles were searched and a total of 1770 records were identified. After removing duplicates and engaging in three levels of screening to identify studies that included adolescents ≤ 25 years old and assessed the relationship between general HL (vs. behavior/disease-specific health knowledge) and substance use behaviors and correlates, 16 studies were retained. Studies assessed alcohol-related (n = 11), tobacco-related (n = 12), electronic vapor product use-related (n = 4), cannabis-related (n = 1), and amphetamines/methamphetamines-related (n = 1) outcomes. Studies spanned Africa, Asia, Europe, and North and Central America. Most studies included substance use as an outcome and found an inverse relationship between HL and use. Few studies examined substance use correlates (e.g. risk perception). There were no longitudinal or intervention studies. This review highlighted that the topic of adolescent HL and its relationship with substance use remains inadequately researched. Notable gaps for future studies include intervention and longitudinal designs, expansion of outcomes (e.g. more studies on marijuana, prescription drug misuse, vaping, substance use-related correlates), and examining HL as a mediator or moderator of substance use and its correlates.

Food insecurity and use of electronic vapor products among high school students.

Background: Studies have shown that food insecurity is associated with electronic vapor products (EVP) use in adults; however, an understanding of this relationship in adolescents is needed to inform prevention efforts in this age group. Aim: Examine the relationship of food insecurity with EVP use patterns, frequency and source of acquisition in high school students. Methods: This cross-sectional study used Youth Risk Behavior Survey (YRBS) 2019 data from states that incorporated the YRBS' optional food insecurity question. The data included 42,154 high school students with complete information on food insecurity and two EVP-related questions. Responses to EVP-related questions identified "ever users," "current users," "former users," "current dual EVP-cigarette users," and assessed "frequency of EVP use among current users" and "source of EVP acquisition." Logistic regression examined associations of food insecurity with EVP-related outcomes. Results: The proportion of high school students who ever used EVP was 48.3% and the proportion of food-insecure students was about 12%. Food security status significantly differed by race/ethnicity of students, such that the proportion of food insecure students classified as "non-Hispanic White" was lower than the proportion of food secure students classified as "non-Hispanic White." Food insecurity was significantly associated with greater odds of ever EVP use (odds ratio (OR) = 1.75; 95% confidence interval (CI) = (1.55, 1.96)), current EVP use (OR = 2.07; 95% CI = (1.80, 2.37); using never users as reference category) and current dual use of EVP and cigarettes (OR = 2.91; 95% CI = (2.38, 3.55)). Food insecurity also was associated with greater odds of current EVP use (OR = 1.54; 95% CI = (1.28, 1.84)) when former users were used as reference category. In current users, food insecurity was related to greater odds of daily EVP use (OR = 1.40; 95% CI = (1.14, 1.70)) compared to occasional use. Conclusions: Study findings imply that efforts targeting prevention/cessation of EVP use should consider reducing food insecurity in high school students.

Optimizing fouling mitigation in membrane distillation by controlled microbubble size and concentration

Fouling control strategies play a crucial role in membrane distillation (MD) process, primarily due to the significant limitation of fouling during the scaling-up process. The utilization of microbubbles (MBs) aeration has exhibited promising potential in mitigating membrane fouling when treating high salinity wastewater. Aeration can introduce gas-liquid two-phase flow on the membrane surface, thereby increasing the membrane surface shear force. The mechanism of aeration technology for controlling fouling includes the following points: introduction of gas-liquid two-phase flow; physical substitution of concentration polarization layer; pressure pulses caused by bubbles flowing through the membrane surface and increasement of the cross flow velocity. This research aims to optimizing the effect of air MBs with different concentrations and sizes introduced in the feed side on membrane fouling control, we creatively used the method of releasing pressure gradiently to achieve size regulation of MBs within a certain range for the first time, firstly regulated the generation of MBs by manipulating gas flow rate and release pressure. Under the optimal condition of 40 mL/min and 0.6 MPa, it will yield concentration of 1.58 × 104/mL and D50 Sauter size of 64.69 μm MBs with pure water permeance flux of 12.32 kg/(m2·h). It was observed that higher gas flow rates primarily increased MBs concentration, while lower pressures predominantly reduced MBs size through the method of inline imaging. Experimental results indicated that introduction of MBs can slightly improve the temperature polarization coefficient and mass transfer coefficient under different operating modes. Consequently, further investigations focused on the influence of MBs characteristics on different fouling control. All conditions reach 99 % rejection for inorganic salt and HA. This study provided empirical evidence that higher concentration and larger size of MBs intensify the gas-liquid two-phase flow disruption and exhibit a better shear effect on scaling phenomena, which yield advantageous outcomes in terms of augmenting permeance flux and water vapor production, with permeance flux increased from 40.12 % to 55.42 % for inorganic fouling and increased from 68.35 % to 80.15 % for inorganic and HA fouling. These results were confirmed via membrane surface using scanning electron microscopy and energy dispersive spectroscopy. In summary, this research aided in identifying appropriate operating conditions for mitigating inorganic and composite scaling by implementing air-infused MBs in direct contact membrane distillation (DCMD), which provides scientific and technical guidance for controlling fouling in MD in practical applications.

An experimental study of dynamic flashing in a square tube using tap water

Flashing is a pressure driven phase change phenomenon. It is widely studied due to its richness in physics and applications such as in desalination, in nuclear industry to name a few. Dynamic flashing is a situation wherein the pressure drop for flashing is initiated through the flow of liquid. A recently developed novel desalination system [1] utilizes combined dynamic flashing and vapor separation through tangential injection for producing potable water. An understanding of dynamic flashing in a tube with reference to the novel desalination system could help with its optimization. In this work, dynamic flashing of tap water occurring in a clear quartz square tube was studied. The pressure and temperature measurements along the tube were made and analyzed for different inlet flowrates and initial liquid temperatures. The pressure and temperature values showed increasing gradients along the tube indicating increased vapor production or flashing for increasing flowrates and initial liquid temperatures. The vapor production from flashing and the resulting flow regimes along the tube were tracked and identified through high-speed imaging. Visual observations showed complex flow regimes with bubbles nucleating and growing throughout the tube due to flashing. Most of the bubble formation was observed in the bulk with little nucleation on the glass tube wall. Void fraction measurements along the tube based on capacitance impedance technique were performed to supplement the visual observations which showed increasing void fraction along the tube matching the observed flow regimes from vapor production.

A simulation‐guided tri‐spiral condenser design for enhancing lemongrass essential oil recovery

AbstractWe present a groundbreaking achievement in essential oil extraction, showcasing the development of a highly efficient tri‐spiral condenser for use in microwave‐assisted extraction (MAE) setups. This innovative condenser is specifically designed to swiftly cool vapors, optimizing oil yield during the MAE process. Our investigations demonstrate a notable improvement in oil purity, attributed to the expedited condensation facilitated by the tri‐spiral design. Traditional heat exchangers, like the Liebig condenser, fall short in efficiently handling the high vapor production rates of MAE. In response to this challenge, our tri‐spiral condenser design enhances condensation speed, resulting in a remarkable 12.2% increase in oil yield compared with the Liebig condenser (2.1% with tri‐spiral vs. 1.87% with Liebig), as validated by Gas Chromatography–Mass Spectrometry. Beyond elevating oil purity, our design holds promise for diverse applications requiring rapid cooling. This work not only advances laboratory practices but also contributes to the broader societal need for efficient and sustainable methods in the essential oil extraction industry.Practical applicationsThe innovative tri‐spiral condenser design, as elucidated in this article, presents significant practical applications, especially in the realm of lemongrass essential oil recovery. This breakthrough technology holds promise for the fragrance and cosmetics industries, where lemongrass essential oil is a valuable ingredient. The novel condenser design enhances extraction efficiency, leading to a higher concentration of essential oil with improved aromatic compounds. Cosmetic manufacturers can benefit from a more potent and fragrant lemongrass oil for skincare and aromatherapy products. Additionally, the pharmaceutical sector could leverage this advancement for developing therapeutic products harnessing the medicinal properties of lemongrass. By optimizing essential oil recovery, the tri‐spiral condenser design not only caters to the needs of the fragrance, cosmetic, and pharmaceutical industries, but also aligns with a broader trend towards sustainable and efficient manufacturing practices, ensuring the accessibility of high‐quality lemongrass essential oil for diverse applications.

Construction of a meteorological application system based on BDS ground-based augmentation network and water vapor products validation

The national Beidou Navigation Satellite System (BDS) ground-based augmentation network (BGAN) of China is constructed with the existing GNSS observation resources of industrial sectors and local governments, based on the concept of joint building and sharing with sustainable development. This study provides a detailed introduction to the design, construction and operation of a meteorological application system based on BGAN, and validation of its water vapor products. BDS and GPS real-time observation of atmospheric water vapor is achieved nationwide in China and multi-GNSS applications. Through the application of multi-GNSS data and validation of the water vapor products from 2018 to 2020, the accuracy of precipitable water vapor (PWV) derived from BDS only is equivalent to that from GPS only. The root mean square error (RMSE) between them is about 2 mm with high correlation coefficient. Based on radiosonde data, the validation is conducted with the products of BDS-PWV, GPS-PWV, and Combined-PWV derived with multi-GNSS of BDS and GPS. The error characteristics of the three products show a consistent trend over the months. The bias is relatively small. The RMSE of the three products is in the range of 2.18–2.73 mm. The BDS-PWV has the largest RMSE, followed by GPS-PWV, and Combined-PWV has the smallest RMSE.

A grid model for vertical correction of precipitable water vapor over the Chinese mainland and surrounding areas using random forest

Abstract. Various ground-based observing techniques provide precipitable water vapor (PWV) products with different spatial resolutions. To effectively integrate these products, especially in terms of vertical orientation, spatial interpolation is essential. In this context, we have developed a model to characterize PWV variation with altitude over our study area. Our model, known as RF-PWV (a PWV vertical correction grid model with a 1° × 1° resolution), is constructed using random forest based on the relationship between the differences in different pressure level PWV data from the fifth-generation European Centre for Medium-Range Weather Forecasts reanalysis (ERA5) monthly average hourly data and corresponding differences in their height differences over time. When validated against 1 h ERA5 PWV profiles, RF-PWV exhibits a 99.84 % reduction in bias and a 63.41 % decrease in the RMSE compared with the most recent model, C-PWVC1. Furthermore, when validated against radiosonde data, RF-PWV shows a 96.36 % reduction in bias and a 5 % decrease in the RMSE compared with C-PWVC1. Additionally, RF-PWV outperforms C-PWVC1 in terms of resistance to seasonal and height difference interference. The model eliminates the need for meteorological parameters, allowing for high-precision PWV vertical correction by inputting only time and height differences. Consequently, RF-PWV can significantly reduce errors in vertical correction, enhance PWV fusion product accuracy, and provide insights into PWV vertical distribution, thereby contributing to climate research.