Characterization of the vertical evolution of urban nocturnal boundary layer by UAV measurements: Insights into relations to cloud radiative effect.

The complex structure of the nocturnal boundary layer (NBL) and its impact on air pollution remain poorly understood. In this study, we present in-situ nocturnal flight measurements onboard an unmanned aerial vehicle (UAV) during the wintertime of 2022 at an urban site in Hefei, China. Besides, co-located measurements of radiation intensity and total amount of cloud were conducted. The vertical distribution of temperature, particle number concentration, and relative humidity were obtained to study the structure of NBL and the key factors driving the evolution of the NBL. A multi-layer inversion boundary layer was observed during haze and fog episodes, which affects the vertical diffusion of particles near the surface and leads to a vertical gradient of particle number concentrations. The particle size distribution demonstrates a drastic vertical variation over different sections of the nocturnal boundary layer: homogeneously mixed in the SBL and the RL layer, sharply reduced in the IL. It is found that the temperature and particle number concentration differences between near-surface and at 500 m are highly related to variations of the radiation intensity and the amount of cloud. The decreased cloud cover enhances the surface cooling, creating a shallow NBL with multiple inversion layers, which reinforces the suppression of vertical diffusions and consequently promotes the accumulation of aerosols within the NBL. This reveals an important mechanism for the impact of NBL evolution modulated by cloud radiative effect on the formation of urban haze.

In Situ Quantitative Observation of Hygroscopic Growth of Single Nanoparticle Aerosol by Surface Plasmon Resonance Microscopy.

Aerosol particle hygroscopicity is an important factor in visibility reduction, cloud formation, radiation forcing, and the global climate. The high number concentration of nanoparticles (defined as particles with diameters below 100 nm) means that their hygroscopic growth abilities and potential contributions to the climate and environment are significant. Therefore, a rapid and accurate in situ analysis method for single nanoparticle hygroscopic growth in an atmospheric environment is important to characterize the effects of the particle's physical and chemical properties in this process. In this work, surface plasmon resonance microscopy with azimuthal rotation illumination (SPRM-ARI) is used to observe the hygroscopic growth and water content of single nanoparticles in situ. The hygroscopic growth results of a single-component nanoparticle are well matched with the extended aerosol inorganic model (E-AIM) results, and the proposed method remains reliable even when the relative humidity (RH) exceeds 90%. For a bicomponent nanoparticle (with NaCl as the primary content), the presence of a component without deliquescence phase transitions under increasing humidity conditions causes the measured data to differ from both the Zdanovskii-Stokes-Robinson (ZSR) model and E-AIM predictions in the low RH range. However, because of their complete liquefaction, the growth factor (GF) variation of the bicomponent nanoparticle is close to the model predictions in the high RH range. Finally, based on the positive correlation between particle volume and the gray intensity of SPRM-ARI, GF values can be obtained from the cube root of the gray intensity and the actual water content of single nanoparticles can then be derived.

Simulation-Based Design and Optimization of Rectangular Micro-Cantilever-Based Aerosols Mass Sensor.

Micro-Cantilever (MCL) is a thin film structure that is applied for aerosol particle mass sensing. Several modifications to the rectangular MCL (length-to-width ratio, slots at the anchor, serrations at its side edges) are made to deduce the role and influence of the shape of rectangular MCL-based aerosol mass sensors and reduce gas damping. A finite element fluid-structure interaction model was used to investigate the performance of MCL. It is found that (I) the mass sensitivity and quality factor decline with the increasing of length-to-width ratio which alters the resonant frequency of the MCL. The optimum conditions, including the length-to-width ratio (σlw = 5) and resonant frequency (f0 = 540.7 kHz) of the MCL, are obtained with the constant surface area (S = 45,000 µm2) in the frequency domain ranging from 0 to 600 kHz. (II) The slots can enhance the read-out signal and bring a small Q factor drop. (III) The edge serrations on MCL significantly reduce the gas damping. The results provide a reference for the design of aerosol mass sensor, which makes it possible to develop aerosol mass sensor with high frequency, sensitivity, and quality.

Advanced testing method to evaluate the performance of respirator filter media.

Filter media for respirator applications are typically exposed to the cyclic flow condition, which is different from the constant flow condition adopted in filter testing standards. To understand the real performance of respirator filter media in the field it is required to investigate the penetration of particles through respirator filters under cyclic flow conditions representing breathing flow patterns of human beings. This article reports a new testing method for studying the individual effect of breathing frequency (BF) and peak inhalation flow rate (PIFR) on the particle penetration through respirator filter media. The new method includes the use of DMA (Differential Mobility Analyzer)-classified particles having the most penetrating particle size, MPPS (at the constant flowrate of equivalent mean inhalation flow rate, MIFR) as test aerosol. Two condensation particle counters (CPCs) are applied to measure the particle concentrations at the upstream and downstream of test filter media at the same time. Given the 10 Hz sampling time of CPCs, close-to-instantaneous particle penetration could be measured. A pilot study was performed to demonstrate the new testing method. It is found that the effect of BF on the particle penetration of test respirator filter media is of importance at all the tested peak inhalation flow rates (PIFRs), which is different from those reported in the previous work.

A Machine Learning Method for Power Prediction on the Mobile Devices.

Energy profiling and estimation have been popular areas of research in multicore mobile architectures. While short sequences of system calls have been recognized by machine learning as pattern descriptions for anomalous detection, power consumption of running processes with respect to system-call patterns are not well studied. In this paper, we propose a fuzzy neural network (FNN) for training and analyzing process execution behaviour with respect to series of system calls, parameters and their power consumptions. On the basis of the patterns of a series of system calls, we develop a power estimation daemon (PED) to analyze and predict the energy consumption of the running process. In the initial stage, PED categorizes sequences of system calls as functional groups and predicts their energy consumptions by FNN. In the operational stage, PED is applied to identify the predefined sequences of system calls invoked by running processes and estimates their energy consumption.

In vitro particle size distributions in electronic and conventional cigarette aerosols suggest comparable deposition patterns.

INTRODUCTION: Electronic cigarette users ("vapers") inhale aerosols of water, nicotine, and propylene glycol (PG) or vegetable glycerin (VG). Aerosol particle sizes should affect deposition patterns in vapers and bystanders. METHODS: Aerosols were generated by a smoking machine and an electronic cigarette filled with 16mg/ml nicotine in aqueous PG or VG solution. A scanning mobility particle sizer (SMPS) counted particles of 10-1,000 nm diameters. A single puff experiment counted particles immediately and after aging 10 and 40 s. A steady-state experiment counted particles emitted from a collection chamber, untreated and after desiccation or organic vapor removal. The International Commission on Radiological Protection (ICRP) human respiratory tract model was used to estimate deposition. Results were compared to similar data from reference cigarettes. RESULTS: Puffs generated peak particle counts at (VG) 180 nm and (PG) 120 nm. Steady-state peaks occurred around 400 nm. Organic vapor removal eliminated small particles and reduced the size and number of large particles. Desiccation reduced the total volume of particles by 70% (VG, small PG) to 88% (large PG). The ICRP model predicted 7%-18% alveolar delivery; 9%-19% venous delivery, mostly in the head; and 73%-80% losses by exhalation. Reference cigarettes generated more particles initially, but were otherwise similar; however, in vivo smoke particle deposition is higher than the model predicts. CONCLUSIONS: Nicotine delivery may depend on vaping technique, particle evolution, and cloud effects. Predicted 10% arterial and 15% venous delivery may describe bystander exposure better than vapers exposure.

Evolving MCDM applications using hybrid expert-based ISM and DEMATEL models: an example of sustainable ecotourism.

Ecological degradation is an escalating global threat. Increasingly, people are expressing awareness and priority for concerns about environmental problems surrounding them. Environmental protection issues are highlighted. An appropriate information technology tool, the growing popular social network system (virtual community, VC), facilitates public education and engagement with applications for existent problems effectively. Particularly, the exploration of related involvement behavior of VC member engagement is an interesting topic. Nevertheless, member engagement processes comprise interrelated sub-processes that reflect an interactive experience within VCs as well as the value co-creation model. To address the top-focused ecotourism VCs, this study presents an application of a hybrid expert-based ISM model and DEMATEL model based on multi-criteria decision making tools to investigate the complex multidimensional and dynamic nature of member engagement. Our research findings provide insightful managerial implications and suggest that the viral marketing of ecotourism protection is concerned with practitioners and academicians alike.

Vertical profile of aerosol number size distribution during a haze pollution episode in Hefei, China.

The vertical distribution of aerosols has important implications on haze formation as development, which is manifested to some extent by the planetary boundary layer (PBL)-aerosol interactions. Information on the number concentration and size of particles is essential to understand these processes, but studies on vertical profiles of particle number-size distribution are limited. Herein, an unmanned aerial vehicle (UAV) equipped with a custom-built optical particle counter (0.4-10 µm) was used to investigate the vertical profiles of particle number-size distribution in Hefei (China) during January 20-30, 2021. Combining ground-based scanning mobility particle sizer and meteorological data, the pollution accumulation and diffusion mechanisms were analyzed in depth. Results showed that as the pollution episode developed, the vertical distribution of the particle number concentration changed from a flat profile to a sharp vertical gradient. Under polluted conditions, a three-layer structure was clearly evident: uniform distribution in a mixed layer near the ground, a sharply reduced transition layer, and a low number concentration layer in the free atmosphere. Analysis revealed that fundamental to this conversion is that aerosols are highly affected by the PBL dynamics. Concurrent on-UAV and ground-based observations revealed that the ratio of particle numbers in the accumulation mode to that in the Aitken mode was 0.92 ± 0.05 in polluted days, which was almost three times that of clean days. This difference in the ratio of large to small particles suggests that hygroscopic growth of aerosol particles under high humidity conditions played an important role in haze development. Moreover, the sharp vertical gradient of the particle number concentration in the transition layer was identified as an important parameter for characterizing PBL height. The findings in this study highlight the importance of PBL dynamics on the under-studied vertical profiles of particle number-size distribution, especially during heavy pollution episodes.

Dietary administration of berberine or Phellodendron amurense extract inhibits cell cycle progression and lung tumorigenesis.

Phellodendron amurense extract is a Chinese herbal remedy that has recently been studied for its antitumor, antimicrobial and other biological activities. It is previously unknown if these agents are bioavailable and effective against tumors when delivered as a dietary component. It is also unknown if the anti-tumorigenic properties of berberine, an isoquinoline alkaloid component of P. amurense, is equally effective when administered alone. There are contrasting reports on the cellular processes involved in anti-tumorigenesis by P. amurense and berberine. Here we find that berberine, when administered orally through the diet, inhibits in vivo tumorigenesis of both p53 expressing and p53 null lung tumor xenografts equally whether administered in its pure form or as a part of P. amurense extract. We also show that berberine induces G1 cell cycle arrest, inhibits proliferative kinase signaling and arrests the growth of lung tumor cells in culture. Berberine administered in the diet was detectable by HPLC in the lungs of mice fed P. amurense or equivalent doses of berberine at concentrations of 455 and 518 ng/ml respectively and inhibited the growth of xenografted A549 cell tumors, which grew to 9.4 and 6.4 mm³ respectively, compared to 58.9 mm³ in control mice (P < 0.001). Phosphorylation of Akt, CREB and MAPK was inhibited in A549 cells by P. amurense. Demonstration of oral bioavailability and anti-tumorigenic efficacy of dietary berberine, as well as further demonstration of signaling pathway modulation and cell-cycle arrest, implicate this relatively safe, natural compound as a potentially important therapeutic and chemopreventive agent for lung cancer.

Chemoprevention of lung carcinogenesis by the combination of aerosolized budesonide and oral pioglitazone in A/J mice.

Budesonide, a synthetic glucocorticoid used for treating asthma, and pioglitazone, a synthetic peroxisome proliferator-activated receptors γ ligand used for the treatment of diabetes, were evaluated for their combinational chemopreventive efficacy on mouse lung cancer using female A/J mice with benzo(a)pyrene used as the carcinogen. All chemopreventive treatments began 2-wk post-carcinogen treatment and continued daily for 20 wk. Budesonide was administered by the aerosol route using an improved aerosol delivery system. Pioglitazone was introduced by oral gavage. The characterization of drug distribution showed that budesonide introduced by aerosol delivery accumulated only in the lung. Budesonide alone reduced tumor load by 78% and pioglitazone alone reduced tumor load by 63%. By combining aerosolized budesonide with pioglitazone, the inhibition on tumor load was 90%. In vitro experiments using human cancer cells showed that budesonide and pioglitazone exhibited independent, additive inhibitory effects on cell growth. Our results provide evidence that aerosolized budesonide and oral pioglitazone could be a promising drug combination for lung cancer chemoprevention.

Single virus and nanoparticle size spectrometry by whispering-gallery-mode microcavities.

Detecting and characterizing single nanoparticles and airborne viruses are of paramount importance for disease control and diagnosis, for environmental monitoring, and for understanding size dependent properties of nanoparticles for developing innovative products. Although single particle and virus detection have been demonstrated in various platforms, single-shot size measurement of each detected particle has remained a significant challenge. Here, we present a nanoparticle size spectrometry scheme for label-free, real-time and continuous detection and sizing of single Influenza A virions, polystyrene and gold nanoparticles using split whispering-gallery-modes (WGMs) in an ultra-high-Q resonator. We show that the size of each particle and virion can be measured as they continuously bind to the resonator one-by-one, eliminating the need for ensemble measurements, stochastic analysis or imaging techniques employed in previous works. Moreover, we show that our scheme has the ability to identify the components of particle mixtures.

Using a modified electrical aerosol detector to predict nanoparticle exposures to different regions of the respiratory tract for workers in a carbon black manufacturing industry.

The present study was set out to characterize nanoparticle exposures in three selected workplaces of the packaging, warehouse, and pelletizing in a carbon black manufacturing plant using a newly developed modified electrical aerosol detector (MEAD). For confirmation purposes, the MEAD results were compared with those simultaneously obtained from a nanoparticle surface area monitor (NSAM) and a scanning mobility particle sizer (SMPS). We found that workplace background nanoparticle concentrations were mainly coming from the outdoor environment. Size distributions of nanoparticles for the three selected process areas during the work hours were consistently in the form of bimodel. Unlike nanoparticles of the second mode (simply contributed by the process emissions), particles of the first mode could be also contributed by the forklift exhaust or fugitive emissions of heaters. The percents of nanoparticles deposited on the alveolar (A) region were much higher than the other two regions of the head airway (H), tracheobronchial (TB) for all selected workplaces in both number and surface area concentrations. However, significant differences were found in percents of nanoparticles deposited on each of the three regions while different exposure metrics were adopted. Both NSAM and MEAD obtained quite comparable results. No significant difference can be found between the results obtained from SMPS and MEAD after being normalized. Considering the MEAD is less expensive, less bulky, and easy to use, our results further support the suitability of using MEAD in the field for nanoparticle exposure assessments.

Charged droplet dynamics in the submicrometer size range.

The highly charged droplets produced by electrospray are of significant importance in analytical chemistry, particularly in mass spectrometry. In spite of this, little is known about the mechanisms of charge loss for highly charged droplets in the submicrometer size range. In this study, electropsrayed droplet charge loss dynamics in the submicrometer size range were examined for the first time using tandem differential mobility analysis (TDMA) of aerosol particles originally enclosed in methanol-water droplets. After complete droplet evaporation, the remaining aerosol particles carried the nonejected charges from droplets; thus, particle electrical mobility spectra are reflective of the electrical mobility spectra of droplets of similar size. Bayesian data inversion was used to compare measured electrical mobility spectra to models for droplet losing charge by Coulombic fission and by single ion emission. Data inversion showed that, at a size of approximately 40 nm, a transition of the mechanism of charge loss occurred. Methanol-water droplets larger than this size lost charge through Coulombic fissions at the Rayleigh limit with an effective surface tension of 0.050 N m(-1), while droplets in the 10-40 nm size range lost charge through ion emission, maintaining a constant electric field of 1.1 V nm(-1) on their surface during ion emission. This transition was observed experimentally for the first time in this study and is in good agreement with theoretical predictions from prior study of ion emitting nanodroplets. The data presented here provide the necessary link between studies of highly charged micrometer sized droplet and those of highly charged liquid clusters.

Use of the electrical aerosol detector as an indicator of the surface area of fine particles deposited in the lung.

Because of recent concerns about the health effects of ultrafine particles and the indication that particle toxicity is related to surface area, we have been examining techniques for measuring parameters related to the surface area of fine particles, especially in the 0.003- to 0.5-microm size range. In an earlier study, we suggested that the charge attached to particles, as measured by a prototype of the Electrical Aerosol Detector (EAD, TSI Inc., Model 3070), was related to the 1.16 power of the mobility diameter. An inspection of the pattern of particle deposition in the lung as a function of particle size suggested that the EAD measurement might be a useful indicator of the surface area of particles deposited in the lung. In this study, we calculate the particle surface area (micrometer squared) deposited in the lung per cubic centimeter of air inhaled as a function of particle size using atmospheric particle size distributions measured in Minneapolis, MN, and East St. Louis, IL. The correlations of powers of the mobility diameter, Dx, were highest for X = 1.1-1.6 for the deposited surface area and for X = 1.25 with the EAD signal. This overlap suggested a correspondence between the EAD signal and the deposited surface area. The correlation coefficients of the EAD signal and particle surface area deposited in the alveolar and tracheobronchial regions of the lung for three breathing patterns are in the range of Pearson's r = 0.91-0.95 (coefficient of determination, R2 = 0.82-0.90). These statistical relationships suggest that the EAD could serve as a useful indicator of particle surface area deposited in the lung in exposure and epidemiologic studies of the human health effects of atmospheric particles and as a measure of the potential surface area dose for the characterization of occupational environments.

In vitro release profiles of PLGA core-shell composite particles loaded with theophylline and budesonide.

We investigated the effects of drug loading location, matrix material and shell thickness on the in vitro release of combinational drugs from core-shell PLGA (i.e., poly(lactic-co-glycolic acid)) particles. Budesonide and Theophylline were selected as highly hydrophobic and hydrophilic model drugs, respectively. The dual-capillary electrospray (ES) technique, operated at the cone-jet mode, was used to produce samples of drug-loaded core-shell composite particles with selected overall sizes, polymer materials, and shell thicknesses. Theophylline and Budesonide were loaded at different locations in a PLGA composite particle. This study illustrated how the aforementioned factors affect the release rates of Budesonide and Theophylline loaded in core-shell PLGA composites. We further identified that core-shell composite particles with both model drugs loaded in the core and with matrix PLGA polymers of low molecular weights and low LA/GA ratios are the best formulation for the sustained release of highly hydrophilic and hydrophobic active pharmaceutical ingredients from PLGA composite particles. The formulation strategy obtained in this study can be in principle generalized for biopharmaceutical applications in fixed-dose combination therapy.

Oppositely charged twin-head electrospray: a general strategy for building Janus particles with controlled structures.

Because of their unique heterostructure characteristics and anisotropic surface properties, Janus particles have gained growing interest in a number of novel applications. For the first time we demonstrate a facile, but versatile and general strategy for large-scale building of Janus particles with controlled structures and chemical composition pairs by an oppositely charged twin-head electrospray. In this protocol, two different droplets electrosprayed respectively from two tip-to-tip nozzles at high voltages of opposite polarities, after solvent evaporation and precursor gelation, collide with each other and coagulate into one Janus particle because of the Coulombic attractive forces. The as-electrosprayed droplets show different transient phase states at collision depending on the kinetic parameters such as the chemical compositions of precursors, humidity, concentration of solvent vapour, etc. Thus the resultant Janus particles have various morphologies and structures controlled by the transient phase state of the eletrosprayed droplets as well as the post-heat-treatment parameters. As examples, we demonstrate here the controlled fabrication of metal oxide-metal oxide and metal oxide-metal sulphide Janus particles with solid snowman-like, hollow-bowl snowman-like, and pot-like structures. Because of their unique heterostructure and novel morphology characteristics, the as-prepared Janus particles, despite a polydispersity in size and inhomogeneity in morphology, have some important potential applications including photocatalytic hydrogen production, environment remediation, and nanomotors.

Influence of precursor solvent properties on matrix crystallinity and drug release rates from nanoparticle aerosol lipid matrices.

The crystallinity of drug-loaded lipid nanoparticles is believed to affect drug release rates; however, effective control over lipid crystallinity has not been achieved by current lipid nanoparticle preparation methods. The present study investigates control over the crystallinity of drug-loaded nanoparticle aerosol lipid matrices (NALM) through differences in evaporation rates of precursor solution drops and the subsequent control over drug release rates from these matrices. Gefitinib-loaded NALM were synthesized in an aerosol reactor using precursor solutions of gefitinib and stearic acid at a ratio of 1:4 w/w in organic solvents with high (dichloromethane) and low (ethyl acetate and chloroform) vapor pressures. Mean mobility diameter measured using a scanning mobility particle sizer was in the range of 123-132 nm with a unimodal distribution and a geometric standard deviation of 1.6-1.9. A layered particle structure was observed using transmission electron microscopy, which suggests partial drug enrichment in the surface layer. Higher drug loading (20% w/w) and uniform entrapment efficiencies (∼100%) were achieved. The initial drug to lipid ratio (1:4 w/w) of the precursor solution was preserved in the synthesized lipid matrices. The crystallinity of the gefitinib-loaded lipid matrix was measured using X-ray diffraction and differential scanning calorimetry. In vitro drug release from gefitinib-loaded NALM in phosphate buffered saline (pH 7.2) over 10 days showed an initial fast release period followed by a prolonged sustained release period with varying release rates. Gefitinib-loaded NALM synthesized at higher evaporation rates exhibited lower degrees of crystallinity and faster drug releases. These results suggest the determinant role of lipid crystallinity manipulated by differing evaporation rates during aerosol synthesis on drug releases from nanometer-sized lipid matrices.

Facile preparation of magnetic γ-Fe2O3/TiO2 Janus hollow bowls with efficient visible-light photocatalytic activities by asymmetric shrinkage.

In this paper, on the basis of a simple side-by-side co-electrospray procedure with a subsequent non-equilibrium calcination process, we have for the first time developed an asymmetric shrinkage approach for the fabrication of magnetic γ-Fe(2)O(3)/TiO(2) Janus hollow bowls (JHBs) by constructing a precursor solution pair with different gelation rates during the solvents evaporation process. The formation mechanisms of the bowl-shapes as well as the hollow interiors are proposed and confirmed. The as-obtained γ-Fe(2)O(3)/TiO(2) JHBs have a transition layer of Fe(3+)-doped-TiO(2) between the γ-Fe(2)O(3) and TiO(2) phases, and show an efficient visible-light photocatalytic activity and convenient magnetic separation for water purification because of the unique structure and morphology as well as the fine magnetic properties. Moreover, the method reported here can be readily extended to the fabrication of other bi-, tri- and multi-component metal oxides hollow particles with asymmetric shapes. Due to the interesting bowl-shaped hollow nanostructure, the as-prepared γ-Fe(2)O(3)/TiO(2) JHBs are expected to have a number of applications that involve drug delivery, micro-/nano-motors, microcontainers, microreactors, sensors, and so forth.

Multidrug encapsulation by coaxial tri-capillary electrospray.

This study describes how a coaxial tri-capillary electrospray (ES) system can synthesize monodisperse PLGA-coated particles containing multiple drugs in one step. The coaxial arrangement of three separate capillaries in an ES nozzle enables production of composite particles with tri-layered structures without the complicated steps involved in emulsion processes. Various materials can be encapsulated in separate layers of individual composite particles without regard for the hydroscopic property of drugs. At the proper spray setting, nearly 100% drug encapsulation efficiency can be achieved. By varying the feed flowrate of spray solutions, the overall particle sizes, ranging from submicrometer to micrometer, and the thickness of the layers in produced particles can also be controlled. Size and tri-layered structure of the composite particles were characterized by SEM and laser scanning confocal microscopy (LSCM). We further explored the spray technique in the production of tri-layered composite particles having a controlled multidrug-release profile, and compared the release profiles of both core-shell structured particles (produced by coaxial dual-capillary ES) and tri-layered ones (produced by coaxial tri-capillary ES). The comparison showed that composite particles with the tri-layered structure can release multiple drugs in distinct kinetic phases. We further demonstrated that the release profile of tri-layered composite particles can be effectively controlled by varying the thickness and chemical composition of their individual layers.

Note: Electrohydrodynamic atomization of liquid sheet.

Novel electrohydrodynamic atomization via liquid sheet is presented herein to produce monodisperse. Instead of multiple capillaries/holes used in previous publication, the spray heads with a circular slit exit, shaping the spray liquid into a thin sheet, were utilized. A number of notches were machined along the outer edge of an annular slit to bifurcate the liquid sheet into multiple jets and anchor them to establish the stable multijet operation. The liquid-sheet electrospray heads with 6, 12, and 20 notches were investigated in this study. It is observed that, for spraying liquids of low electrical conductivity, the maximal liquid flowrate of a 20-notched head is 166 times higher than that of single capillary with an inner diameter the same as the slit spacing of studied heads. The above observation evidences that the liquid-sheet electrospray technique and heads have excellent potential for high mass throughput while keeping the spray head cost low.