Variation Of Size Distribution Research Articles

A Comparative Study on the Vertical Structures and Microphysical Properties of Stratiform Precipitation over South China and the Tibetan Plateau

Under different water vapor and dynamic conditions, and the influence of topographies and atmospheric environments, stratiform precipitation over South China and the Tibetan Plateau can produce different features. In this study, stratiform precipitation vertical characteristics, bright-band (BB) microstructures, and the vertical variations of the raindrop size distribution (DSD) over a low-altitude site (Longmen site, 86 m) in South China and a high-altitude site (Nagqu site, 4507 m) on the Tibetan Plateau were comprehensively investigated and compared using measurements from a Ka-band millimeter-wave cloud radar (CR), a K-band microrain radar (MRR), and a Parsivel disdrometer (disdrometer). A reliable BB identification scheme was proposed on the basis of CR variables and used for stratiform precipitation sample selection and further statistics and analysis. Results indicate that melting layers over the Longmen are much higher and slightly thicker than those over the Nagqu due to significant differences in atmospheric conditions. For stratiform precipitation, vertical air motions and radar variables over the two sites show different variation trends from cloud top to the ground. Vertical air motions are very weak in the stratiform precipitation over the Longmen, whereas updrafts are more active over the Nagqu. Above the melting layer, radar equivalent reflectivity factor Ze (mean Doppler velocity VM) gradually increases (decreases) as height decreases over the two sites, but the aggregation rate for ice particles over the Longmen can be faster. In the melting layer, Ze (VM) at the BB bottom/center over the Longmen is larger (smaller) than those over the Nagqu for the reason that melted raindrops in the melting layers over the Longmen are larger than those over the Nagqu. Below the melting layer, profiles of radar variables and DSDs show completely different behaviors over the two sites, which reflects that the collision, coalescence, evaporation, and breakup processes of raindrops are different between the two sites. Over the Longmen, collision and coalescence dominate the precipitation properties; in particular, from 2.0–2.8 km, the breakup process competes with collision–coalescence processes but later is overpowered. In contrast, due to the lower BB heights over the Nagqu, collision and coalescence dominate raindrop properties. Comparisons of raindrop spectra suggest that the concentration of small (medium-to-large) raindrops over the Nagqu is much higher (slightly lower) than that over the Longmen. Therefore, the mass-weighted mean diameter Dm (the generalized intercept parameter Nw) over the Nagqu is smaller (larger) than that over the Longmen.

The interseasonal features of precipitation microphysics over Thiruvananthapuram and Kolkata - the two tropical stations of Indian sub-continent

A comparative study of precipitation microphysics along with the possible causative mechanisms for the inter-seasonal variation of raindrop size distribution over Thiruvananthapuram and Kolkata – the two tropical stations of Indian sub-continent has been highlighted in this paper. In addition to the contrasting geographical and climatic variations, the importance of the two locations lies in the fact that the rainfall over Thiruvananthapuram represents the Arabian Sea branch of south-west monsoon while that over Kolkata represents the Bay of Bengal branch. The study reveals a distinct domination of raindrops of diameter 2 mm and above for the pre-monsoon months (March–May) over Kolkata with respect to Thiruvananthapuram, while for the monsoon months (June–September), no such appreciable differences are noticed. Correspondingly, the continental and maritime clouds also show their contrasting impacts in the rainfall microphysics during these inter-seasonal phases for the two locations. It has been observed that rainfall evolving from the continental clouds during the pre-monsoon period over Kolkata produces distinct diurnal variation of rainfall occurrences, which are also associated with the presence of raindrop of diameter 3 mm and above. Correspondingly, such variations are absent for the maritime clouds which dominate the monsoon rainfall for both the locations. Thus it can be said that the nature of clouds along with the surface temperature plays an important role in the varying microphysics of precipitation during the inter-seasonal phases of monsoon over these two cities of India.

Fractional Laplacian spectral approach to turbulence in a dusty plasma monolayer

This work presents an analytical investigation of anomalous diffusion and turbulence in a dusty plasma monolayer, where energy transport across scales leads to the spontaneous formation of spatially disordered patterns. Many-body simulations of 10 000-particle dusty plasma monolayers are used to demonstrate how the global dynamics depend on the statistical properties of the dust assembly for realistic laboratory conditions. We find that disorder due to variations in the dust size distribution and charge-driven nonlocal interactions resulting in anomalous dust diffusion are key factors for the onset of instabilities. The resulting dynamics exhibit features of inertial turbulence over slightly more than half a decade of scales proportional or smaller than the Debye shielding length. These processes are examined analytically using a recently developed Fractional Laplacian Spectral technique, which identifies the active energy channels as a function of scale, disorder concentration, and features of the nonlocal interactions. The predictions from the theoretical (spectral) analysis demonstrate agreement with the results from the many-body (kinetic) simulations, thus providing a powerful tool for the study of active turbulence.

Composite binder, processing, and particle size effects on mechanical properties of non-hazardous high explosive surrogates

Plastic-bonded explosives (PBX) are polymer matrix composites that are highly loaded with micron-scale explosive crystals. The thermal and mechanical properties of these materials must be well-understood so that appropriate engineering models can be developed, but testing such properties under many scenarios can be hazardous and expensive. A non-hazardous PBX surrogate (“mock”) may be used in place of a PBX in many experiments if the thermomechanical properties are well-matched. Our previous research has shown that 5-iodo-2′-deoxyuridine (IDOX) is a promising crystalline filler material for the explosive cyclotetramethylene-tetranitramine (HMX). Here, we investigate how the binder composition, variations in the IDOX particle size distribution, and pressing temperature affect the compressive strength and elastic modulus. We observe that while the binder system used in the composite dominates the mechanical response, the particle size distribution and pressing conditions do have a measurable effect on the material compliance and strength.

Microphysical Characteristics of Rainfall Observed by a 2DVD Disdrometer during Different Seasons in Beijing, China

The seasonal variations of raindrop size distribution (DSD) and rainfall are investigated using three-year (2016–2018) observations from a two-dimensional video disdrometer (2DVD) located at a suburban station (40.13° N, 116.62° E, ~30 m AMSL) in Beijing, China. The annual distribution of rainfall presents a unimodal distribution with a peak in summer with total rainfall of 966.6 mm, followed by fall. Rain rate (R), mass-weighted mean diameter (Dm), and raindrop concentration (Nt) are stratified into six regimes to study their seasonal variation and relative rainfall contribution to the total seasonal rainfall. Heavy drizzle/light rain (R2: 0.2~2.5 mm h−1) has the maximum occurrence frequency throughout the year, while the total rainfall in summer is primarily from heavy rain (R4: 10~50 mm h−1). The rainfall for all seasons is contributed primarily from small raindrops (Dm2: 1.0~2.0 mm). The distribution of occurrence frequency of Nt and the relative rainfall contribution exhibit similar behavior during four seasons with Nt of 10~1000 m−3 registering the maximum occurrence and rainfall contributions. Rainfall in Beijing is dominated by stratiform rain (SR) throughout the year. There is no convective rainfall (CR) in winter, i.e., it occurs most often during summer. DSD of SR has minor seasonal differences, but varies significantly in CR. The mean values of log10Nw (Nw: mm−1m−3, the generalized intercept parameter) and Dm of CR indicate that the CR during spring and fall in Beijing is neither continental nor maritime, at the same time, the CR in summer is close to the maritime-like cluster. The radar reflectivity (Z) and rain rate (?) relationship (Z = ?R?) showed seasonal differences, but were close to the standard NEXRAD Z-R relationship in summer. The shape of raindrops observed from 2DVD was more spherical than the shape obtained from previous experiments, and the effect of different axis ratio relations on polarimetric radar measurements was investigated through T-matrix-based scattering simulations.

Eulerian formulation for the triboelectric charging of polydisperse powder flows

We propose an Eulerian formulation for the triboelectric charging of powder flows. Recently, continuum descriptions of the charging of monodisperse and bidisperse powder appeared. Now, we propose the first Eulerian formulation for this type of flows that can fully account for polydisperse particle size distributions. To this end, the joint particle size, velocity, and charge distribution function are solved through the direct quadrature method of moments. The newly established approach includes the uptake of electrostatic charge by the particles when contacting a solid wall and the exchange of charge in-between particles during collisions. The electrostatic field induced by the charge of the particles and the drag forces of the surrounding gas affects the particle dynamics. Test cases of two-dimensional steady channel flows demonstrate the charging of the flow from the walls toward the center and in the downstream direction. Further, the method predicts the effect of variations of the particle size and initial velocity distribution and the charge diffusion coefficient. The ability to handle polydispersity is a step toward the simulation of the electric charge buildup of real powder flows in full-scale technical applications.

Physicochemical and hydrodynamic aspects of GdFeO3 production using a free impinging-jets method

A free impinging-jets microreactor (FIJMR) was successfully used for the ultrafast co-precipitation of gadolinium and iron(III) hydroxides and subsequent production of fine GdFeO3 nanoparticles via precipitate heat treatment in the air. The effects of the concentration of Gd3+ and Fe3+ ions (c = 0.001-0.1 mol/L), the temperature of the reaction solutions (t = 0-50°C), the flow rate of the solutions (Qj = 100-400 mL/min) and the jets impingement angle (2θ = 90-180°) on the mixing mode and nanoparticle size were comprehensively analyzed. The impact of co-precipitation parameters was discussed in detail from both physicochemical and hydrodynamic points of view. It was shown that the FIJMR co-precipitation resulted in isometric GdFeO3 nanoparticles with variable average size (<D> = 22.8-40.6 nm) and size distribution variance (FWHM = 19.7-32.2 nm). The optimal parameters were found to be c = 0.01 mol/L, t = 0°C, Qj = 200 mL/min and 2θ = 90° and allowed to produce ultrafine GdFeO3 nanoparticles (<D> = 22.8 nm) with narrow size distribution (FWHM = 20.5 nm), unified morphology, high visible-light absorption and superparamagnetic behavior. Based on these results, FIJMR-assisted co-precipitation was concluded to be an efficient and prospective method for the physicochemical design and production of advanced functional nanopowders.

Dynamic stormwater management to mitigate phosphorous export

Altered stormwater flow characteristics and associated changes in nutrient and sediment fluxes due to urbanization threaten the water quality of many water bodies. For example, particle-bound phosphorus in stormwater runoff adds to the nutrient pool that can produce harmful algal blooms, and the associated particulate material can endanger fish and other living organisms in surface waters by increasing turbidity. While many studies have investigated how Total Solids (TS) particle size distributions vary in urban stormwater and the associated design criteria for Best Management Practices (BMPs) to remove TS, few studies have included different forms of phosphorus and their association with particle sizes to characterize design criteria to specifically maximize Total Phosphorus (TP) removal. This highlights a gap in our understanding of how the particle size distributions of TP and TS are related, and how these particle size distributions vary within and between storm events. Bridging this knowledge gap can improve design methods for BMPs specifically targeting phosphorus removal. This study characterizes within event (i.e., hourly) TP and TS particle size distributions and associated fluxes from urban catchments in the City of Cambridge, Massachusetts, to characterize potential TP and TS removal based on four different diversion and treatment strategies. The stormwater diversion strategies integrate new insights on temporal variations in particle size distributions and mass loading characteristics. In terms of diverted stormwater, the volume of stormwater treated tends to control more than what water is treated (e.g., first flush, event high flows, or smaller event flows). Based on the event data obtained in this study, considering flow volume different diversion approaches are optimal for TP vs TS, but treatment combined with particles sizes < 100 μm is best for both TP and TS.

Formation mechanism of arsenic-containing dust in the flue gas cleaning process of flash copper pyrometallurgy: A quantitative identification of arsenic speciation

The proper disposal of arsenic-containing smelting dust has been an important challenge in the copper pyrometallurgy industry which is mostly limited by the variability of arsenic content and species in different types of dusts. The eight types of flash smelting dusts produced along the gas line have been extensively characterized and comparatively studied. Arsenic content gradually increases along the flash smelting (FS) and flash converting (FC) parts of the gas line, and a negative correlation with the pH and copper content has been observed. PM10 accounts for 81.65% and 95.02% of the flash copper furnance (FSF) dust pocket dust and FSF electrostatic precipitator (ESP) dust, respectively. The size distribution variation inply the As enrichment in finer particles. The valence state of arsenic tends to migrate to reach higher valence states along both the FSF and FCF gas line, and the formation mechanism of different types of arsenic particles differs. The As(III)-O mainly remains in the WHB convection part dust and most of them are oxidized to arsenate compounds. More than 80% of the arsenic species was present in the ESP as As(V) and As(III)-arsenite. Fragmentation of concentrate particles and rapid condensation by gas phases lateral flushing of the pipe may produce arsenic particles in the waste heat boiler (WHB), while those remaining in the dust pocket and the ESP may result from adsorption, condensation, and chemical reactions. Temperature is the main factor that affects the deposition site of As2O3 particles. Alkali metal oxide particles influence As content and speciation in dusts by promoting the arsenate formation.

Soil infiltration characteristics and pore distribution under freezing–thawing conditions

Abstract. Frozen soil infiltration widely occurs in hydrological processes such as seasonal soil freezing and thawing, snowmelt infiltration, and runoff. Accurate measurement and simulation of parameters related to frozen soil infiltration processes are highly important for agricultural water management, environmental issues, and engineering problems in cold regions. Temperature changes cause soil pore size distribution variations and consequently dynamic infiltration capacity changes during different freeze–thaw periods. To better understand these complex processes and to reveal the freeze–thaw action effects on soil pore distribution and infiltration capacity, black soils, meadow soils, and chernozem were selected as test subjects. These soil types account for the largest arable land area in Heilongjiang Province, China. Laboratory tests of soils at different temperatures were conducted using a tension infiltrometer and ethylene glycol aqueous solution. The stable infiltration rate and hydraulic conductivity were measured, and the soil pore distribution was calculated. The results indicated that for the different soil types, macropores, which constituted approximately 0.1 % to 0.2 % of the soil volume under unfrozen conditions, contributed approximately 50 % of the saturated flow, and after soil freezing, the soil macropore proportion decreased to 0.05 % to 0.1 %, while the saturated flow proportion decreased to approximately 30 %. Soil moisture froze into ice crystals inside relatively large pores, resulting in numerous smaller-sized pores, which reduced the number of macropores but increased the number of smaller-sized mesopores, so that the frozen soil infiltration capacity was no longer solely dependent on the macropores. After the ice crystals had melted, more pores were formed within the soil, enhancing the soil permeability.

More Significant Impacts From New Particle Formation on Haze Formation During COVID-19 Lockdown.

During the COVID‐19 lockdown in 2020, large‐scale industrial and transportation emissions were reduced, but high PM2.5 concentration still occurred. This study investigated the variation of particle number size distribution during the lockdown, and analyzed the characteristics of new particle formation (NPF) events and its potential impact on haze formation. Through measurement conducted in urban Beijing during the first 3 months of 2020, and comparison with year‐over‐year data, the decrease of primary Aitken‐mode particles was observed. However, frequencies, formation rates and growth rates of NPF events remained stable between 2020 and 2019 in the same period. As a result, >25 nm particles produced by NPF events, would play a more important role in serving as the haze formation “seeds” compared to those produced by primary emissions. This finding emphasizes the significance on the understanding of NPF mechanisms when making pollution mitigation policy in the future.

Spatial and environmental characteristics of colloidal trace Cu in the surface water of the Yellow River Estuary, China

Dynamic variations in chemical composition and size distribution of dissolved copper (Cu) along the river-sea interface in the Yellow River Estuary (China) were investigated. On average, ~64% and ~8% of bulk dissolved Cu (<0.45 μm) were partitioned in the <1 kDa fraction and 1–100 kDa, respectively. The other 28% were in the 100 kDa–0.45 μm colloids, which indicates that this fraction may dominate the overall morphology of colloidal Cu. The <3 kDa Cu fraction was susceptible to environmental parameters and the >3 kDa fraction was related to the behavior of dissolved organic carbon. 1–100 kDa Cu migrated more violently than >100 kDa Cu and tended to be a stable polymer, with stability increasing towards the sea. The source of <1 kDa Cu was complex and may be supplemented by the decomposition of small molecular colloids and the addition of the sediments or particles ligands.

Impact of pH-dependent succinylation on the structural features and emulsifying properties of chicken liver protein

This work aims at investigating the pH-regulated relationship between the structural features and emulsifying properties of chicken liver protein (CLP) during succinylation and related mechanisms behind. The results demonstrated that the major succinylation sites occurred at lysine, histidine and tyrosine of CLP, and the succinylation degree increased by 30.66% as pH increased to 10. The succinylation pH elevation increased the solubility and oil absorption capacity of CLP, thus favoring its improvement in emulsifying properties, due to the succinylation process-induced increase in surface charge density and amphiphilic balance as well as modified network structure. However, the surface hydrophobicity of succinylated products decreased by 10.75% when the pH increased from 7 to 10. Besides, succinylation-induced variations in electrostatic repulsive and particle size distribution greatly improved the storability of the emulsions. These results suggested the great potential of pH-modulated succinylation to regulate the structure–property relationship of protein-based products.

Loss of soil carbon and nitrogen rather than variations in soil particle size distribution decreased microbial residues during conversion of grassland to croplands

AbstractConversion of grassland into cropland always induces a great degradation of soil organic carbon (SOC). However, during this process information on microbial residue C (MR‐C) and its contribution to SOC with increasing conversion age remain scarce. The relative contribution of soil properties to the accumulation of amino sugars is still poorly understood. Here, we studied variations in soil amino sugars and MR‐C, and their contribution to SOC with increasing conversion age (5 (M05), 16 (M16) and 34 (M34) years, respectively) from grassland to cropland. In contrast to the contents of glucosamine, fungal glucosamine, galactosamine, muramic acid, total amino sugars and MR‐C in grassland, those in M05 decreased in the range of 14.8–37.5%, and those in M34 decreased in the range of 31.8–65.1%, respectively. The contents of amino sugars and MR‐C did not differ between M16 and M34. The similar contribution of MR‐C to SOC (44.6–46.3%) in grassland, M16 and M34 is likely to result from a balance between microbial and non‐degraded plant residues. Decreasing ratios of fungal to bacterial residue C with conversion age indicated a decreased relative contribution of fungal residues to SOC, which probably resulted from the decreased percentage of macroaggregates. MR‐C and SOC decreased and reached a steady status in a few years (≧16 a) after conversion of grassland to cropland. The redundancy analysis model revealed that total nitrogen (TN), pH, SOC and available nitrogen (AN) played a bigger role than particle size distribution, in terms of explaining the contribution of amino sugars to soil carbon.Highlights Conversion of grassland into cropland decreased amino sugars and microbial residues. The contribution of MR‐C to SOC peaked in M05. The relative contribution of fungal residues to SOC decreased with increasing conversion age. TN and SOC contributed more to the accumulation of amino sugars than particle size distribution.

Dust Growth in Molecular Cloud Envelopes: A Numerical Approach

Abstract Variations in the grain size distribution are to be expected in the interstellar medium (ISM) owing to grain growth and destruction. In this work, we present a dust collision model to be implemented inside a magnetohydrodynamic (MHD) code that takes into account grain growth and shattering of charged dust grains of a given composition (silicate or graphite). We integrate this model in the MHD code Athena and build on a previous implementation of the dynamics of charged dust grains in the same code. To demonstrate the performance of this coagulation model, we study the variations in the grain size distribution of a single-sized population of dust with radius 0.05 μm inside several dust filaments formed during a 2D MHD simulation. We also consider a realistic dust distribution with sizes ranging from 50 Å to 0.25 μm and analyze the variations in both the size distribution for graphite and silicates and the far-ultraviolet extinction curve. From the obtained results, we conclude that the methodology here presented, based on the MHD evolution of the equation of motion for a charged particle, is optimal for studying the coagulation of charged dust grains in a diffuse regime such as a molecular cloud envelope. Observationally, these variations in the dust size distribution are translated into variations in the far-ultraviolet extinction curve, and they are mainly caused by small graphite dust grains.

An experimental investigation on engineering properties of undisturbed loess under acid contamination.

Even though soil acidification can cause significant destabilizing effects on various geotechnical issues, studies have rarely been conducted to determine the influence of soil structure on the impact of acid-contaminated soil. The current work aims to understand the effect of acid fluids on engineering behavior of undisturbed loess through laboratory tests. The sampling site is in a typical region of Loess Plateau, China. The variations in particle size distribution, Atterberg limits, uniaxial compression strength, and permeability were investigated with the help of microstructure for a better understanding of the governing mechanism of undisturbed loess subjected to acid fluids. It was found that exposure to acid fluids can improve the particle size distribution of loess. In contrast, the experimental results indicated that acid fluids can decrease Atterberg limits and strength and permeability of loess, although Atterberg limits and strength of loess are considerably increased in a highly sulfuric acid environment. Then, analyzing the engineering response in the light of microstructure revealed that the face-to-face contacts primarily exist in loess prepared with hydrochloric acid and nitric acid, respectively, whereas the mosaic structure is indeed active in sulfur-contaminated loess. Furthermore, a micro-conceptual structure was proposed based on the experiment led to the conclusion that the cementitious salt and structural characteristics play a dominant role in governing the engineering behavior of loess under acidic conditions.

Variation in size distribution of juvenile pink shrimps Farfantepenaeus brasiliensis and F. paulensis in the estuarine-adjacent ocean area of Cananéia, south-eastern coast of Brazil

AbstractThe study characterized the structure of juveniles and sub-adults of Farfantepenaeus brasiliensis and F. paulensis in the Cananéia-Iguape estuarine lagoon system and its adjacent coastal area by evaluating the period of juvenile recruitment, sex ratio, growth, longevity, natural mortality, and development time until the late juvenile phase. Samples were collected from July 2012 to June 2014. Shrimps were identified by species and sex, and measured (carapace length – CL mm); 889 individuals of F. brasiliensis and 848 of F. paulensis were analysed. Females were more abundant than males for both species. The growth parameters of F. brasiliensis were: CL∞ = 45.5 mm, k = 1.8 year−1 for males and CL∞ = 55.2 mm, k = 1.6 year−1 for females; longevity of 2.52 years (males) and 2.88 years (females); and natural mortality of 1.71 (males) and 1.55 (females). For F. paulensis, the following values were observed: CL∞ = 40.7 mm, k = 2.3 year−1 for males and CL∞ = 56.5 mm, k = 1.9 year−1 for females; longevity of 2.04 years (males) and 2.37 years (females); and natural mortality of 2.39 (males) and 2.05 (females). The juvenile recruitment of both species peaked in January 2014. The development time until late juvenile phase was ~7 months (F. brasiliensis) and ~5 months (F. paulensis). Even though the highest abundance of juveniles did not occur in the closed season, fishing is forbidden in the estuarine area and the migration towards the adult population occurred close to or even during the closed season.

Modeling a fluidized bed reactor by integrating various scales: Pore, particle, and reactor

AbstractThis work proposes a novel population‐balance based model for a bubbling fluidized bed reactor. This model considers two continuum phases: bubble and emulsion. The evolution of the bubble size distribution was modeled using a population balance, considering both axial and radial motion. This sub‐model involves a new mathematical form for the aggregation frequency, which predicts the migration of bubbles from the reactor wall toward the reactor center. Additionally, reacting particles were considered as a Lagrangian phase, which exchanges mass with emulsion phases. For each particle, the variation of the pore size distribution was also considered. The model presented here accurately predicted the experimental data for biochar gasification in a lab‐scale bubbling fluidized bed reactor. Finally, the aggregation frequency is shown to serve as a scaling parameter.

Particle curvature effects on microstructural evolution during solid-state sintering: phenomenological insights from phase-field simulations

Local curvatures have a profound influence on sintered microstructure. Here, using phase-field simulations, particle curvature effects were phenomenologically investigated by using geometrical configurations of two, three, and four particles, and by systematically varying particle curvatures. Some geometries, involving two, three and four particles, exhibited the expected smooth neck-length evolution, where the maximum neck length was determined by grain boundary (GB) energy ( $$\gamma _{GB}$$ ) rather than surface energy ( $$\gamma _{S}$$ ). In contrast, triangular arrangement of particles with unequal radii manifested a secondary necking event in form of a step during neck evolution. The secondary necking event coincided with internal pore collapse, and only specific range of particle radius ratios manifested such a mechanism. $$\gamma _{S}$$ played a dominant role in triggering the secondary necking event, while $$\gamma _{GB}$$ determined the remnant microstructure. Broadly, the geometries employed here allow us to computationally examine the sintering of particles that display wide variation in shapes and size distributions.

Fabrication of WO3 electrochromic devices using electro-exploding wire techniques and spray coating

Electrochromic devices (ECDs) play an important role in smart window applications for blocking heat from sunlight. Tungsten trioxide (WO3) is one of the best candidates for making electrochromic films. Current manufacturing processes are, however, costly, have long processing time, and often use non-eco-friendly precursors. Here an alternative facile method integrating electro-exploding wire and spray coating techniques is demonstrated for applications in large size ECDs. The electro-exploding wire technique is used to synthesize WO3 nanomaterials (NMs) in deionized water. The varied size distribution of WO3 NMs is achieved by changing the exploding voltage. The NMs are characterized by X-ray diffractometer (XRD), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). The exploding voltage of 36 V is selected to generate WO3 NMs in a wide size distribution for making porous WO3 films. Subsequently, spray coating is used to disperse WO3 NM suspension on the ITO/glass substrate to form an electrochromic film. The films are characterized by scanning electron microscopy (SEM) and by cycle voltammetry, chronoamperometry, and chronocoulometry measurements in dilute sulfuric acid. The WO3 NM films prepared at a high exploding voltage and a high substrate temperature present a higher electrochemical stability. Considering porosity and electrochemical stability, WO3 NMs exploded at 36 V are used to prepare WO3 films on substrates heated at 300 °C. The electrochromic WO3 film can be operated for over 1000 cycles. We demonstrate an ECD with an area of 15 × 15 cm2 and propose a way to make large size ECDs with low cost and eco-friendly processes.