Cumulative Size Distribution Research Articles

New Observational Evidence of Active Asteroid P/2010 A2: Slow Rotation of the Largest Fragment

Abstract We report new observations of the active asteroid P/2010 A2 taken when it made its closest approach to Earth (1.06 au in 2017 January) after its first discovery in 2010. Despite a crucial role of the rotational period in clarifying its ejection mechanism, the rotational property of P/2010 A2 has not yet been studied due to the extreme faintness of this tiny object (∼120 m in diameter). Taking advantage of the best observing geometry since the discovery, we succeed in obtaining the rotational light curve of the largest fragment with Gemini/GMOS-N. We find that (1) the largest fragment has a double-peaked period of 11.36 ± 0.02 hr spinning much slower than its critical spin period; (2) the largest fragment is a highly elongated object (a/b ≥ 1.94) with an effective radius of m; (3) the size distribution of the ejecta follows a broken power law (the power indices of the cumulative size distributions of the dust and fragments are 2.5 ± 0.1 and 5.2 ± 0.1, respectively); (4) the mass ratio of the largest fragment to the total ejecta is around 0.8; and (5) the dust cloud morphology is in agreement with the anisotropic ejection model in Kim et al. These new characteristics of the ejecta obtained in this work are favorable to the impact shattering hypothesis.

Porcolation: An Invasion Percolation Model for Mercury Porosimetry

Mercury porosimetry is utilized primarily in the oil industry to determine the pore size distribution of rock samples. During the process, mercury is forced into the sample with gradually increasing pressure and the volume of the injected mercury is measured vs. the applied pressure (the saturation curve). In practice, the saturation curve is assumed to be directly related the cumulative pore size distribution. However, this distribution does not coincide with the real one because of the “nonaccessibility” of pores at a given pressure. This motivates our goal to determine a more accurate cumulative pore size distribution. To achieve this, we treat the propagation of mercury as a percolation process (dubbed “porcolation” after PORosimetry perCOLATION). Porcolation is an external pressure-driven access-limited invasion percolation model where resistance values are assigned to sites/vertices. As pressure increases, the invading mercury occupies sites with smaller resistance values along paths that are connected to the “boundaries” of the network. Simulations are carried out on regular lattices, as well as on random graphs with prescribed degree distributions (representing the pore network of rock samples). An assumed pore size distribution is considered as an input/parameter of the simulations resulting in an output saturation curve. We determine the input–output mapping (homeomorphism) and utilize its inverse to correct the discrepancies between the assumed and actual pore size distributions. The results show nice agreement between experimental saturation curves and those obtained from our homeomorphism method.

The VMC Survey. XXII. Hierarchical Star Formation in the 30 Doradus-N158–N159–N160 Star-forming Complex

Abstract We study the hierarchical stellar structures in a ∼1.5 deg2 area covering the 30 Doradus-N158–N159–N160 star-forming complex with the VISTA Survey of Magellanic Clouds. Based on the young upper main-sequence stars, we find that the surface densities cover a wide range of values, from log( pc2) ≲ −2.0 to log( pc2) ≳ 0.0. Their distributions are highly non-uniform, showing groups that frequently have subgroups inside. The sizes of the stellar groups do not exhibit characteristic values, and range continuously from several parsecs to more than 100 pc; the cumulative size distribution can be well described by a single power law, with the power-law index indicating a projected fractal dimension D 2 = 1.6 ± 0.3. We suggest that the phenomena revealed here support a scenario of hierarchical star formation. Comparisons with other star-forming regions and galaxies are also discussed.

Local 3D segmentation of soil pore space based on fractal properties using singularity maps

Over the last decade, major technological advances in X-ray computed tomography (CT) have allowed for the investigation and reconstruction of three-dimensional (3D) natural porous media architectures at very fine scales. Soil scientists can use the internal structure information to develop predictive models for a range of physical, chemical and biological processes in soil. Image segmentation and thresholding are crucial steps when applying these methods to extract complex pore space geometry information from images. Traditional thresholding algorithms face challenges related to the heterogeneity of soil samples, noise and artefacts introduced during the image acquisition process.This study proposes a new segmentation method using local greyscale value (GV) concentration variabilities based on fractal concepts. Singularity maps were created to measure the GV concentration at each point. The C-V method was combined with the singularity map approach (Singularity-CV method) to define thresholds that can be applied to binarize CT images.This study also introduces a new method for creating 3D synthetic soil images based on truncated multifractals that simulate low-contrast and non-bimodal GV histograms. A synthetic soil image was created with the objective to compare traditional segmentation methods (Otsu and maximum entropy) with the Singularity-CV method. We obtained better results in porosity and more amount of pores at all scales than traditional methods, although some small pores were incorrectly identified due to the ability to amplify every anomalous GVs. Misclassification error (ME) was low and similar to Otsu.Two different 3D CT soil images were also used in this analysis, corresponding to samples of the same soil with 1.2 and 1.6gcm−3 bulk densities. After applying the Singularity-CV method to the GV images, the results were compared with the aforementioned traditional segmentation methods. The image comparison was based on the porosity, pore size distribution (PSD) and cumulative pore size distribution (CPSD). The Otsu method achieves a higher porosity than the Singularity-CV method because it defines the largest pores. However, the Singularity-CV method detected more pores at all sizes. The maximum entropy method always yielded the lowest porosity.

Certification of New Standard Reference Material 2806b Medium Test Dust in Hydraulic Fluid.

A new material has been certified to become Standard Reference Material (SRM) 2806b - Medium Test Dust in Hydraulic Fluid. SRM 2806b consists of trace polydisperse, irregularly shaped mineral dust particles suspended in hydraulic fluid. The certified values of SRM 2806b are the projected area circular-equivalent diameters of the collected dust particles from the hydraulic fluid. The dimensional measurements were determined from the area of the collected dust particles using images obtained from automated scanning electron microscopy (SEM) followed by image analysis. An automated SEM and an automated image analysis software allowed the processing of over 29 million particles. The dimensional calibration of the SEM images (actual length per pixel and thus the actual projected diameters) are traceable to the NIST Line Scale Interferometer (LSI) through a NIST calibrated Geller MRS-4XY pitch standard. The certified diameters are correlated with the numeric concentration of particles greater than each diameter, referred to as the cumulative number size distribution. SRM 2806b is intended to be used to calibrate liquid-borne optical particle counters in conjunction with the reference method ISO 11171:2010.

Dust particle flux and size distribution in the coma of 67P/Churyumov-Gerasimenko measured in situ by the COSIMA instrument on board Rosetta

Context. The COmetary Secondary Ion Mass Analyzer (COSIMA) on board Rosetta is dedicated to the collection and compositional analysis of the dust particles in the coma of 67P/Churyumov-Gerasimenko (67P). Aims. Investigation of the physical properties of the dust particles collected along the comet trajectory around the Sun starting at a heliocentric distance of 3.5 AU. Methods. The flux, size distribution, and morphology of the dust particles collected in the vicinity of the nucleus of comet 67P were measured with a daily to weekly time resolution. Results. The particles collected by COSIMA can be classified according to their morphology into two main types: compact particles and porous aggregates. In low-resolution images, the porous material appears similar to the chondritic-porous interplanetary dust particles collected in Earth’s stratosphere in terms of texture. We show that this porous material represents 75% in volume and 50% in number of the large dust particles collected by COSIMA. Compact particles have typical sizes from a few tens of microns to a few hundreds of microns, while porous aggregates can be as large as a millimeter. The particles are not collected as a continuous flow but appear in bursts. This could be due to limited time resolution and/or fragmentation either in the collection funnel or few meters away from the spacecraft. The average collection rate of dust particles as a function of nucleo-centric distance shows that, at high phase angle, the dust flux follows a 1/ d 2 comet law, excluding fragmentation of the dust particles along their journey to the spacecraft. At low phase angle, the dust flux is much more dispersed compared to the 1/ d 2 comet law but cannot be explained by fragmentation of the particles along their trajectory since their velocity, indirectly deduced from the COSIMA data, does not support such a phenomenon. The cumulative size distribution of particles larger than 150 μ m follows a power law close to r − 0.8 ± 0.1 , confirming measurements made by another Rosetta dust instrument Grain Impact Analyser and Dust Accumulator (GIADA). The cumulative size distribution of particles between 30 μ m and 150 μ m has a power index of −1.9 ± 0.3. The excess of dust in the 10–100 μ m range in comparison to the 100 μ m–1 mm range together with no evidence for fragmentation in the inner coma, implies that these particles could have been released or fragmented at the nucleus right after lift-off of larger particles. Below 30 μ m, particles exhibit a flat size distribution. We interprete this knee in the size distribution at small sizes as the consequence of strong binding forces between the sub-constitutents. For aggregates smaller than 30 μ m, forces stronger than Van-der-Waals forces would be needed to break them apart.

New segmentation method based on fractal properties using singularity maps

To improve our understanding of the factors that control a number of critical soil processes, it is important to properly identify pore space zones. Computed tomography (CT) images provide increasingly reliable information about the geometry of pores and solids in soils at very small scales and are a non-invasive technique. However, the low contrast between voids and pores and the non-bimodal greyscale value (GV) histograms observed in the CT images present a problem with respect to pore identification.In this work, we propose a new segmentation method based on the local GV concentration variability when using singularity maps. We also introduce a new method for creating synthetic CT soil images based on truncated multifractals that simulate low-contrast and non-bimodal GV histograms.From three different bidimensional CT soil images and one synthetic soil image, singularity maps were created to measure the GV concentration at each point by defining areas with self-similar properties that were shown as power-law relationships in Concentration-Area plots (C-A method). The C-A method together with a singularity map (the “Singularity-CA” method) was used to define thresholds that were applied to binarize the CT images. Promising results were obtained when the greyscale images were overlapped with the borders of the binarized images.Once these black and white images were obtained, we compared them with commonly used segmentation methods: the Otsu, Iterative and Maximum Entropy methods. The image comparison was based on the total porosity, cumulative pore size distribution (CPSD), cumulative pore size–area distribution (CPSAD) and misclassification error (ME). We found that the Otsu and the Iterative methods overestimated the size of large pores compared to the ground-truth image, which overestimated the porosity. Conversely, the Singularity-CA method extracted medium and large pores with a good fit compared to the ground-truth image. It was observed that whereas the Otsu and Iterative methods obtained the large pores, the “Singularity-CA” method detected an aggregate of small pores, although many of these small pores were incorrectly identified. This was due to the latter's high sensitivity when detecting anomalous GV values. The Maximum Entropy method always resulted in the lowest porosity in the real CT soil samples and the greatest porosity in the synthetic soil image samples.

Fluid flow in complex porous media: Experimental data and IFU model predictions for water vapour permeability

In this research work, an Intermingled Fractal Units' model (IFU's model) has been proposed with the aim of predicting water vapour permeability characteristics of porous rock, normally studied in gas reservoir field. IFU modelling approach commences with the reproduction of experimental pore size distribution with the help of diverse fractal base units mixed together. This procedure allows simulating the porous microstructure in terms of pore cumulative curve or pore size distribution. An analytical procedure is used for obtaining the permeability values. The studied rocks include limestone from South Sardinia quarries and have similar characteristics of those studied in gas reservoir field. They have been taken from four different parts (systems A, B, C and D) of the quarry for the assessment of the heterogeneity of this rock. From the experimental tests, the average water vapour permeability values are equal to 7.22 ± 1.22, 4.21 ± 1.51, 10.09 ± 1.11 and 10.12 ± 2.4210−12 kg m−1 s−1 Pa−1 respectively for systems A, B, C and D, whereas predictions by IFU are respectively equal to 7.15 ± 1.55, 4.25 ± 1.45, 10.12 ± 1.22 and 9.98 ± 2.1810−12 kg m−1 s−1 Pa−1. The comparison shows a good capacity of IFU procedure to predict water vapour permeability values.

Geophysical and geochemical alteration of rocks in granitic profiles during intense weathering in southern Purulia district, West Bengal, India

Purulia district of West Bengal is geologically dominated mostly by Proterozic hard granite gneiss rocks including soft phyllite and mica schist of Singhbhum group as part of Chotanagpur plateau. Present study aims to understand the nature of geophysical and geochemical weathering processes for characterization of granitic crust as well as the geochemical ways of this alteration. During the field study 14 rocks and soils samples were collected from three sections of each weathering profile in three different blocks namely, Manbazar-I, Manbazar-II and Banduan. The samples were collected along the roads cuts, natural and other man-made exposures and restricted mostly within the exposed layers of the respective profiles. The samples were analyses in sieve for particle size distribution and in X-ray diffraction for mineralogical alteration. The thin section of selected samples were analysed under polarized optical microscope for understanding the nature of physical and chemical changes in parent rocks. From sieve analysis, the cumulative particle size distribution show that the size of weathered materials gradually reduces from saprolite to overlying soils in every profile. Mineralogical analysis by XRD shows that feldspar, muscovite, quartz and biotite are the primary minerals which are intensely weathered and have undergone some geochemical processes except quartz, to form some secondary clay minerals like montmorillonite, kaolinite and illite in the overlying soil. Optical microscopic analysis reveals that transformation of primary minerals to secondary clay minerals significantly reduced the rocks strength which leads the rocks disintegrate into smaller particles. Finally, the results show that there is an abundance of montmorillonite and altered primary minerals with gravel materials in the profiles are liable for further weathering to develop a mature soil.

TOTAL PARTICULATE MATTER, PM10, PM2.5 EMISSIONS FROM PALM OIL MILL BOILER

Utilization of fiber and shell as boiler fuel in palm oil mill industry generates particulate emission that need to be controlled before emitting to the environment. This study investigates the particulate mass size distribution of particulate matter sampled from palm oil mills having different boiler capacities. The particulate emission was performed at the stack following US EPA Method 17 and while the particulate size distribution was determined using particle size analyzer. Results showed that the total particulate mass concentration varied between 0.42 and 3.77 g/Nm3 (corrected at 7% O2). The emitted particulate was mainly found in the coarse particles, with 50% cumulative size distribution ranged from 21 to 38 µm. The particulate mass concentration of PM2.5 and PM10 of the total particulate emission was varied from 0.03 to 0.30 g/Nm3 and 0.37 to 0.73 g/Nm3, respectively. This contributes 0.8 to 71% and 13 to 95% of the total particulate mass concentration, respectively.

Investigation of a pilot-scale wet electrostatic precipitator for the control of sulfuric acid mist from a simulated WFGD system

Wet electrostatic precipitator (WESP) was often regarded as an effective countermeasure for sulfuric acid mist emitted from coal-fired power plants. However, recent studies indicate that WESP is an ambivalent measure due to its negative effect of generating ultrafine aerosols, which could lead to non-negligible solvent emission from amine based post-combustion capture (PPC) device. In this study, we attempt to clearly reveal how the key parameters, i.e. operating voltage and flue gas velocity, affected these ultrafine aerosols formation inside a pilot WESP. Our investigations have shown that a large number of ultrafine sulfuric acid aerosols formed in the WFGD process, with a cumulative size distribution (CSD) percentage close to 100% for aerosols below 150nm. With the activation of WESP, size distribution of sulfuric acid aerosol shifted towards smaller size. Especially, the percentages of submicron-sized aerosols were significantly increased with the increase of applied voltage. Our results confirmed that plasma-induced effect inside WESP was mainly responsible for ultrafine sulfuric acid aerosol formation, and indicated that its effect was weakening with increasing flue gas velocity. For further decreasing the plasma-induce effect, the investigated WESP was more suitable for operating at a high flue gas velocity with an optimum high voltage level, which could achieve better effect on energy utilization and aerosol control based on both number concentration and mass concentration. The results indicated that at a high flue gas velocity of 2.28m/s and a specific energy input (SEI) of 2.4kWh/1000m3, the mass concentration of sulfur trioxide and total number concentration of sulfuric acid aerosols at the investigated WESP outlet were as low as ~1.0mg/m3 and ~1041/cm3, respectively.

Lunar meteoritic gardening rate derived from in situ LADEE/LDEX measurements

AbstractThe Lunar Atmosphere and Dust Environment Explorer (LADEE) orbited the Moon for approximately 6 months, taking data with the Lunar Dust Experiment (LDEX). LDEX was uniquely equipped to characterize the current rate of lunar impact gardening as it measured the very particles taking part in this process. By deriving an average lunar dust density distribution, we calculate the rate at which exospheric dust rains back down onto the lunar surface. Near the equatorial plane, we find that approximately 40 μm/Myr of lunar regolith, with a cumulative size distribution index of 2.7, is redistributed due to meteoritic bombardment, a process which occurs predominantly on the lunar apex hemisphere.

Coarsening kinetics and the envelope theorem

The scaling properties of microstructural coarsening are studied by means of the envelope theorem, which connects structural features of the projections of an evolving size distribution function in size space and time space. This is made possible by extending the envelope treatment of [P. Streitenberger, D. Zöllner, Acta. Mater. 88 (2015) 334–345] to the time domain, thus establishing a new method of the scaling analysis. An important new finding is that there exists a duality between the pictures of the family of distribution functions in size and time space, according to which the envelope in size space equals to the location of the maxima in time space, and vice versa. For self-similar coarsening the scaling properties are completely reflected by the associated envelopes and maxima in the two complementary representations. The analysis of cumulative size distribution functions for the determination of the growth path of individual particles or grains is extended to the time space. The construction of the envelope curves both, in size space as well as in time space, allows a new and efficient numerical determination of the coarsening kinetics from large four-dimensional datasets of experiments and simulations. This is demonstrated by numerical studies of the results of Monte Carlo Potts model simulations of grain growth, which confirm and complement the analytical results.

Attrition of Victorian brown coal during drying in a fluidized bed

ABSTRACT Analyzing the attrition of Victorian brown coal during air and steam fluidized bed drying, the change in particle size distribution over a range of initial moisture contents (60% to 0%) and residence times (0 to 60 minutes) was determined. Dried at a temperature of 130°C with a fluidization velocity 0.55 m/s and an initial particle size of 0.5–1.2 mm, both fluidization mediums show a shift in the particle size distribution between three and four minutes of fluidization, with a decrease in mean particle size from 665 µm to around 560 µm. Using differential scanning calorimetry (DSC), the change in particle size has been attributed to the transition between bulk and non-freezable water (approximately 55% moisture loss) and can be linked to the removal of adhesion water, but not to fluidization effects. This is proved through the comparison of air fluidized bed drying, steam fluidized bed drying, and fixed bed drying—the fixed bed drying is being used to determine the particle size distribution as a function of drying. The results show the three drying methods produce similar particle size distributions, indicating that both fluidization and fluidization medium have no impact upon the particle size distribution at short residence times around ten minutes. The cumulative particle size distribution for air and steam fluidized bed dried coal has been modeled using the equation P d = A 2 + (A 1 − A 2)/(1 + (d/x 0) p ), with the resultant equations predicting the effects of moisture content on the particle size distribution. Analyzing the effect of longer residence times of 30 and 60 minutes, the particle size distribution for steam fluidized bed dried coal remains the same, while air fluidized bed dried coal has a greater proportion of smaller particles.

Prediction of drop size in a pulsed and non-pulsed disc and doughnut solvent extraction column

Recently a number of industrial scale pulsed disc and doughnut (PDD) solvent extraction columns have been operating with no pulsation. However most of the published research studies in the literature that describe and predict the performance of PDD columns were developed for pulsing conditions. In this study the Sauter-mean drop diameter, d32, was measured and correlated under pulsing and non-pulsing conditions using a 75mm diameter PDD column. Under non-pulsing conditions, the results show that the d32 slightly decreased with increasing dispersed phase velocity, while there was no noticeable change in d32 with continuous phase velocity. Under pulsing conditions, the d32 decreased with increasing pulsation intensity from zero. The cumulative drop size distribution in disc and doughnut columns was found to be predicted well using the Weibull function. A new unified correlation was proposed in this study to predict the experimental d32 data of the PDD column used in this study, as well as published experimental data which was obtained using different systems and column geometries, over a wide range of pulsation rates including no pulsation.

Wind and wave influences on sea ice floe size and leads in the Beaufort and Chukchi Seas during the summer‐fall transition 2014

AbstractSea ice floe size distribution and lead properties in the Beaufort and Chukchi Seas are studied in the summer‐fall transition 2014 to examine the impact on the sea ice cover from storms and surface waves. Floe size distributions are analyzed from MEDEA, Landsat8, and RADARSAT‐2 imagery, with a resolution span of 1–100 m. Landsat8 imagery is also used to identify the orientation and spacing of leads. The study period centers around three large wave events during August–September 2014 identified by SWIFT buoys and WAVEWATCH III® model data. The range of floe sizes from different resolutions provides the overall distribution across a wide range of ice properties and estimated thickness. All cumulative floe size distribution curves show a gradual bending toward shallower slopes for smaller floe sizes. The overall slopes in the cumulative floe size distribution curves from Landsat8 images are lower than, while those from RADARSAT‐2 are similar to, previously reported results in the same region and seasonal period. The MEDEA floe size distributions appeared to be sensitive to the passage of storms. Lead orientations, regardless of length, correlate slightly better with the peak wave direction than with the mean wave direction. Their correlation with the geostrophic wind is stronger than with the surface wind. The spacing between shorter leads correlates well with the local incoming surface wavelengths, obtained from the model peak wave frequency. The information derived shows promise for a coordinated multisensor study of storm effects in the Arctic marginal ice zone.

Characterisation of air-void systems in concrete

The air-void system in both fresh and hardened states for different concrete mixes was measured and characterised using the methods presented in ASTM C231 and ASTM C457 respectively. The mix variables included two water/binder (w/b) ratios (0·33 and 0·45), one replacement level of Portland cement with slag cement (50%) and a range of air contents achieved through the use of different air-entraining agents. Consistent results were obtained on duplicate specimens using the two testing procedures. The cumulative size distribution of the air voids estimated from chord length measurement was satisfactorily represented by an S-shaped function from which the differential distribution can be derived. The importance of air-void fineness on the spacing was clearly illustrated by the small variation in Powers' spacing factor when large air bubbles were included.

Size and albedo distributions of asteroids in cometary orbits using WISE data

We study the distributions of effective diameter ($D$), beaming parameter ($\eta$), and visible geometric albedo ($p_V$) of asteroids in cometry orbits (ACOs) populations, derived from NASA's Wide-field Infrared Explorer (WISE) observations, and compare these with the same, independently determined properties of the comets. The near-Earth asteroid thermal model (NEATM) is used to compute the $D$, $p_V$ and $\eta$. We obtained $D$ and $p_V$ for 49 ACOs in Jupiter family cometary orbits (JF-ACOs) and 16 ACOs in Halley-type orbits (Damocloids). We also obtained $\eta$ for 45 of them. All but three JF-ACOs (95% of the sample) present a low albedo compatible with a cometary origin. The $p_V$ and $\eta$ distributions of both ACO populations are very similar. For the entire sample of ACOs, the mean geometric albedo is $\bar{p_V} = 0.05 \pm 0.02$, ($\bar{p_V} = 0.05 \pm 0.01$ and $\bar{p_V} =0.05 \pm 0.02$ for JF-ACOs and Damocloids, respectively) compatible with a narrow albedo distribution similar to that of the Jupiter family comets (JFCs), with a $\bar{p_V} \sim 0.04$. The $\bar{\eta} =1.0 \pm 0.2$. We find no correlations between $D$, $p_V$ , or $\eta$. We compare the cumulative size distribution (CSD) of ACOs, Centaurs, and JFCs. Although the Centaur sample contains larger objects, the linear parts in their log-log plot of the CSDs presents a similar cumulative exponent ($\beta = 1.85 \pm 0.30$ and $1.76 \pm 0.35$, respectively). The CSD for Damocloids presents a much shallower exponent $\beta = 0.89 \pm 0.17$. The CSD for JF-ACOs is shallower and shifted towards larger diameters with respect to the CSD of active JFCs, which suggests that the mantling process has a size dependency whereby large comets tend to reach an inactive stage faster than small ones. Finally, the population of JF-ACOs is comparable in number that of JFCs, although there are more tens-km JF-ACOs than JFCs.

Reduced hardening of nanocrystalline nickel under multiaxial indentation loading

Abstract

SIGNATURES OF RECENT ASTEROID DISRUPTIONS IN THE FORMATION AND EVOLUTION OF SOLAR SYSTEM DUST BANDS

We have performed detailed dynamical modeling of the structure of a faint dust band observed in coadded IRAS data at an ecliptic latitude of 17$^{\circ}$ that convincingly demonstrates that it is the result of a relatively recent (significantly less than 1 Ma) disruption of an asteroid and is still in the process of forming. We show here that young dust bands retain information on the size distribution and cross-sectional area of dust released in the original asteroid disruption, before it is lost to orbital and collisional decay. We find that the Emilkowalski cluster is the source of this partial band and that the dust released in the disruption would correspond to a regolith layer $\sim$3 m deep on the $\sim$10 km diameter source body's surface. The dust in this band is described by a cumulative size-distribution inverse power-law index with a lower bound of 2.1 (implying domination of cross-sectional area by small particles) for dust particles with diameters ranging from a few $\mu$m up to a few cm. The coadded observations show that the thermal emission of the dust band structure is dominated by large (mm--cm size) particles. We find that dust particle ejection velocities need to be a few times the escape velocity of the Emilkowalski cluster source body to provide a good fit to the inclination dispersion of the observations. We discuss the implications that such a significant release of material during a disruption has for the temporal evolution of the structure, composition, and magnitude of the zodiacal cloud.