Effects Of Mean Particle Size Research Articles

Effect of Mean Particle Size and Uniformity on Modulus Degradation of Nonlinearly Graded Marine Sands

Effect of Mean Particle Size and Uniformity on Modulus Degradation of Nonlinearly Graded Marine Sands

The influence of particle size on the spread distance and angle of friction of granular materials

To produce a hazard map and thus provide mitigation measures against natural catastrophic events such as landslides, avalanches, and debris flows, it is necessary to determine the spread distance of such flows. There is a well-documented relationship between the angle of friction and the debris flow volume, allowing one to determine the possible distance a debris flow can travel. However, the effect of mean particle size (d50) and the sorting coefficient (Sc) on the final spread distance (Df) has received mere attention. In this study, a mini conical-shaped mould was used to measure the final spread distance (Df) and angle of friction (αf) for various dry granular material samples both in air and in water. Experimental results indicated that a granular material sample with a smaller d50 travel a longer distance compared to a sample with a higher d50. However, a sample with a smaller d50 results in a smaller angle of friction than the one with a higher d50. Conversely, a well-sorted sample has a smaller spread distance and larger angle of friction. Results also indicated that the spread distance in air is slightly larger and the angle of friction is slightly smaller than in water.

Parametric and kinetic study of supercritical carbon dioxide extraction on sinensetin from Orthosiphon stamineus Benth. leaves

ABSTRACT Sinensetin is a rare polymethoxyflavone that possesses strong anti-angiogenesis activity that can be obtained from Orthosiphon stamineus (O. stamineus) leaves. In this study, supercritical carbon dioxide (SC-CO2) extraction was used to improve sinensetin recovery from O. stamineus leaves. The effect of mean particle size (400–550, 550–650 and 650–750 µm), modifier ratio (0, 5 and 10%, v/v), flow rate (3, 4 and 5 mL/min), temperature (40, 60 and 80 °C) and pressure (10, 20 and 30 MPa) on the concentration of sinensetin and determine its extraction rate were investigated. Two models, viz. Patricelli and Peleg were used to evaluate the kinetic behavior of sinensetin in the SC-CO2 system. Results showed that the highest concentration of sinensetin was successfully extracted at 550–650 µm, 10% (v/v), 5 mL/min, 80 °C and 10 MPa. Also, the kinetic profile of sinensetin was well correlated with Patricelli and Peleg models with a low percentage average absolute relative deviation (AARD%) and a high coefficient of determination (R2) of <6.37% and >0.974, respectively. Thus, the fastest extraction rate of sinensetin was obtained at 9.039 × 10−3 mg/g min−1 using the Patricelli model and 8.694 × 10−3 mg/g min−1 using the Peleg model at 40 °C and 30 MPa.

Modeling Triaxial Testing with Flexible Membrane to Investigate Effects of Particle Size on Strength and Strain Properties of Cohesionless Soil

A 3D DEM model using Particle Flow Code (PFC3D) software was developed utilizing a bonded-ball flexible membrane approach to study cohesionless soil as a discontinuous discrete material. This approach is not yet widely used because of its complexity and high computational cost, but it allowed the authors to observe the stress-strain curves of triaxial specimens, to single out effects of individual factors on the strength and strain properties, and to observe the formation of the shear band and failure surface. The 3D model was calibrated and verified with experimental data, and a sensitivity analysis was carried out for the microparameters. Triaxial tests were simulated to observe the stress-strain curves and volumetric changes, as well as the strength parameters of soils consisting of spherical particles with different gradations but the same porosity. The authors investigated the effects of mean particle size, larger particle size, smaller particle size, and soil gradation on three soil parameters: peak deviatoric stress, internal friction angle, and dilatancy angle. Four different cases with different soil gradations and particle sizes were studied: a uniform soil, a soil with randomly created particle sizes, and two soils each contains two particle sizes. For two out of the four cases studied, peak deviatoric stress, internal friction angle, and dilatancy angle increased when the mean particle size D50 increased. For the other two cases, the parameters decreased when the mean particle size D50 increased. One important finding is that the relationships between particle size and deviatoric stress, internal friction angle, and dilatancy angle were found to be linear. These relationships can provide predictions on soil strength and strain properties when the particle size changes. Observations and discussions on the formation of shear bands during shear testing are also presented. A step-by-step delineation of the DEM model development is also presented with the development process of a flexible membrane carefully described.

Effect of particle size of sand and surface properties of reinforcement on sand-geosynthetics and sand–carbon fiber polymer interface shear behavior

Soil-reinforcement interface friction is an important geotechnical engineering parameter that needs to be assessed in achieving a safe and cost-effective design. In this study, the effect of mean particle size (D50), type, and surface properties of reinforcements on shear behavior of soil-reinforcement interface were evaluated using direct shear test. Three types of sands with different D50 and similar properties, and six types of reinforcing materials with different surface features; three conventional types (GTX, GGB, and GC) and three novel types (CFRP, SPSCFRP, and GeoFRP), were used for this purpose. The direct shear test (DST) device was modified and proposed to determine the shear strength and friction angle between soil and reinforcements at different normal stresses. Test results revealed that interface shear strength between soil and reinforcements depends on both particle size of the sand and type of reinforcement. The influence of particle size was more significant when coarser size was used since the interlocking behavior occurred between the sand particles and the asperities of reinforcing material. However, the surface roughness of reinforcement affected the shear strength to an extent.

Particle Size Controlled Magnetic Loss in Magnetite Nanoparticles in RF-Microwave Region

Frequency-dependent complex magnetic permeability (μ*) is used to understand RF-microwave behaviour of magnetic nanoparticles in the frequency range 250 MHz to 3 GHz. Four stable dispersions of Fe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> nanoparticles with mean size varying between 11 and 16 nm are prepared for this purpose. The effect of mean particle size and external static magnetic field over dielectric properties of magnetic fluid is studied. The results are explained in the aspect of relaxation and resonance as a consequence of interaction of electromagnetic wave with magnetic fluid. The frequency of ferrimagnetic resonance (f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">res</sub> ) and frequency of maximum absorption (f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">max</sub> ) increases to higher frequency as the mean particle size increases in the fluid. The maximum loss tangent (tan δ) increases, and minimum reflection loss (RL) decreases with mean particle size. The f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">res</sub> , f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">max</sub> , and the maximum tan δ is observed to increase by 55.6%, 15%, and 25.2%, respectively, and minimum RL is observed to decrease by 34.5% by increasing the mean size of Fe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> nanoparticles from approximately 11 to 16 nm in magnetic fluid. By the application of external static magnetic field, structural arrangements of Fe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> nanoparticles can be induced in the fluid. The dielectric properties μ*, tan δ, and RL are reported for increasing field strength 0-915 Oe. The effect of increasing field strength on these properties is also size dependent. As the field strength increases, f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">res</sub> shifts to higher frequencies and the spreading bandwidth is comparatively larger for fluid with the highest mean particle size. The maximum tan δ drops as the field strength increases in the fluid with the highest mean particle size while it raises up to critical field strength then onwards it decreases in the fluid with the lowest mean particle size. The mean particle size and mean anisotropy constant affect the field profiles of dielectric propertiesproperties of the magnetic fluid. This kind of study can be useful for radio-microwave devices like tunable attenuator, EM sheilder, and other microwavemicrowave heating application like hyperthermia.

Study on the feeding characteristics of pulverized coal for entrained-flow gasification

ABSTRACT In this paper, the experimental activity was carried out on five pulverized coals with different particle sizes taken from the industrial demonstration plant of SE-Gasifier Pulverized Coal Gasification in Nanjing, China. Flow properties of pulverized coal including powder cohesion, angle of internal friction and tensile strength were determined by the rotational shear cell accessory of Freeman FT4 Powder Rheometer. These pulverized coal samples were further discharged from a bench-scale discharge system and an industrial device in the SE gasification industrial plant. The effects of mean particle size, fine contents and hopper pressure on the flow properties and the discharge of pulverized coal were discussed. The tensile strength was used to correlate with the feeding characteristics of pulverized coal and proved to be an effective indicator to describe the powder feeding performance. A combination of a continuum approach and a particle–particle approach was therefore built to predict the tensile strength. The model, considered the elastic deformation, was further modified by taking into account the effect of particle size distribution. The predicted tensile strengths were compared with those obtained from the Mohr-Coulomb approach, giving errors mostly below ±25%. It was therefore considered as a valuable way to provide reference for the evaluation of feeding characteristics of pulverized coal for entrained-flow gasification.

Experimental investigation on flow properties of different biomass and torrefied biomass powders

The utilization of biomass has been increasing in recent years, how to achieve successful feeding of biomass into the different utilization systems is a common problem. Reliable information on flow properties are required for the design of storage, processing and handling equipment. In this paper, the flow properties of four representative agricultural biomass powders (soybean straw, corn straw, rice straw and rice husk) and their torrefied powders were investigated experimentally by two different testing methods (angle of repose test and packing properties test) with a powder synthetic characteristic tester. The effects of mean particle size, particle shape, biomass species and their interaction on different characterization parameters (angle of repose, bulk density, tapped density, Hausner ratio and compressibility index) were investigated. The results of the two different testing methods were compared, and it was found that Hausner ratio and compressibility index cannot always accurately characterize the flowability of biomass powders compared with angle of repose. Meanwhile, the effect of torrefaction pretreatment on the flowability of biomass powders was discussed. The results showed that torrefaction pretreatment can improve biomass powder flowability, however, it cannot change the relative relationship between the flowability of different biomass powders.

Effects of Mean Particle Size and Addition Weight Percentage of CaCO3 on Selected Rheological Properties of Filled LDPE

Abstract The present work reports the empirical findings of the effects of mean particle size and weight percentage of CaCO3 on selected rheological characteristics of filled LDPE. The experimental results indicated that the two parameters studied had noticeable influence on the selected rheological properties of LDPE. Studies on the slip velocity and critical shear stress based on Mooney analysis revealed that the designed benefits brought by the incorporation of additives (such as CaCO3) into a polymer (such as LDPE) may not be justified by their possible adverse effects. It is also shown in this report that melt index and apparent viscosity of the selected polymer systems were well correlated with mean particle size of CaCO3 and its weight percentage.

Short communication: In vitro rumen gas production and starch degradation of starch-based feeds depend on mean particle size

Our objective was to model the effect of mean particle size (mPS) on in vitro rumen starch degradation (IVSD) and the kinetics of gas production for different starch-based feeds. For each feed, 2 batches of the same grains were separately processed through 2 different mills (cutter or rotor speed mills), with or without different screens to achieve a wide range of mPS (0.32 to 3.31 mm for corn meals; 0.19 to 2.81 mm for barley meals; 0.16 to 2.13 mm for wheat meals; 0.28 to 2.32 mm for oat meals; 0.21 to 2.36 mm for rye meals; 0.40 to 1.79 for sorghum meals; 0.26 to 4.71 mm for pea meals; and 0.25 to 4.53 mm for faba meals). The IVSD data and gas production kinetics, obtained by fitting to a single-pool exponential model, were analyzed using a completely randomized design, in which the main tested effect was mPS (n = 6 for all tested meals, except n = 7 for corn meals and n = 5 for sorghum meals). Rumen inocula were collected from 2 fistulated Holstein dairy cows that were fed a total mixed ration consisting of 16.2% crude protein, 28.5% starch, and 35.0% neutral detergent fiber on a dry matter basis. The IVSD, evaluated after 7 h of rumen incubation, decreased linearly with increasing mPS for corn, barley, wheat, rye, pea, and faba meals, and decreased quadratically with increasing mPS for the other meals. The y-axis intercept for 7-h IVSD was below 90% starch for corn, barley, and rye feeds and greater than 90% for the other tested feeds. The mPS adjustment factors for the rate of rumen starch degradation varied widely among the different tested feeds. We found a linear decrease in starch degradation with increasing mPS for barley, wheat, rye, and pea meals, whereas we noted a quadratic decrease in starch degradation for the other tested meals. Further, we observed a linear decrease in the rate of gas production with increasing mPS in each tested feed, except for pea meal, which had a quadratic relationship. For each 1 mm increase in mPS, the gas production was adjusted by -0.009 h-1 for corn, -0.011 h-1 for barley, -0.008 h-1 for wheat, and -0.006 h-1 for faba, whereas numerically greater adjustments were needed for oat (-0.022 h-1), rye (-0.017 h-1), and sorghum (-0.014 h-1). These mPS adjustment factors could be used to modify the starch-based feed energy values as a function of mean particle size, although in vivo validation is required.

Rheological properties of gas and water atomized 17-4PH stainless steel MIM feedstocks: Effect of powder shape and size

Influence of powder shape resulting from the fabrication route (gas or water atomization) together with the effect of mean particle size and solid loading on rheological properties of highly filled metal powder feedstocks was investigated as a key to processing of Metal Injection Molding (MIM) parts without voids and cracks. Eight 17-4PH gas or water atomized powders varying in the mean particle diameters from 3 to 20μm were admixed into paraffin wax/high density polyethylene (50/50) binder at powder loadings up to 70vol.%. The relative viscosity data obtained from capillary rheometer was fitted with rheological models to evaluate maximum loading along with the determination of the same parameter using time dependent torque measurement. It was found out that for coarse particles the processability in terms of rheological behavior is better in case of gas atomized powders in accordance with previous findings, but in case of fine powders, water atomized powders showed higher performance.

Effects of phytase, calcium source, calcium concentration and particle size on broiler performance, nutrient digestibility and skeletal integrity

The study herein investigated the effect of mean particle size, calcium (Ca) source, Ca concentration and phytase on broiler performance, mineral digestibility and skeletal integrity from 1 to 28 days post-hatch. Sixteen dietary treatments were arranged in a 2 × 2 × 2 × 2 factorial design consisting of two Ca sources (limestone or a highly soluble calcium, HSC), two Ca concentrations (9.0 or 6.0 g/kg from Day 0 to Day 14 and 8.0 or 5.5 g/kg from Day 15 to Day 28), two Ca particle sizes (&lt;0.5 or &gt;0.5 mm) and two phytase-supplementation levels (0 or 1000 FTU/kg). Overall performance (Days 1–28) showed that the addition of phytase to diets containing 8.0 g/kg total Ca provided by HSC improved feed intake (P &lt; 0.05), but there was no effect of the addition of phytase to birds fed Ca from limestone. Phytase supplementation decreased feed intake in birds fed limestone with a mean particle size &gt;0.5 mm and increased feed intake in birds fed HSC with a mean particle size &gt;0.5 mm, which resulted in a Ca source × Ca particle size × phytase interaction (P &lt; 0.05). Birds fed diets containing HSC had a lower liveweight gain than did birds fed diets containing limestone (P = 0.03). Increasing the dietary Ca concentration from 5.5 g/kg to 8.0 g/kg total Ca decreased liveweight gain (P = 0.01). Phytase supplementation increased final liveweight gain (P &lt; 0.001). Foot ash was observed to be higher in birds that received diets containing 8.0 g/kg Ca (P &lt; 0.05). Phytase supplementation increased foot ash percentage (P &lt; 0.05). Phytase increased Ca digestibility in birds fed diets containing Ca provided by HSC with a mean particle size &lt;0.5 mm and diets containing limestone with a mean particle size &gt;0.5 mm (P &lt; 0.05). Phytase increased Ca digestibility in birds fed 5.5 g/kg Ca, but had no effect on Ca digestibility in birds fed 8.0 g/kg Ca (P &lt; 0.05). The addition of phytase to diets improved the digestibility of phosphorus, especially in birds fed diets containing limestone (P &lt; 0.05), or 8.0 g/kg total Ca (P &lt; 0.05), or diets with a mean particle size &gt;0.5 mm (P &lt; 0.05). The results of the present study are consistent with those of previous studies by the authors, which have shown that low dietary Ca in conjunction with phytase improves broiler performance and mineral digestibility. Phytase improved growth performance, regardless of Ca source or Ca concentration and improved mineral digestibility.

Gas production and starch degradability of corn and barley meals differing in mean particle size

The objective of this study was to verify the effect of mean particle size (mPS) on both gas production and in vitro rumen starch degradability (IVSD) of corn and barley meals (Cm and Bm, respectively). Batches of the same Cm or Bm were separately processed through 2 different mills (i.e., a cutter mill or a rotor speed mill) equipped with or without different screens to achieve different mPS for each tested meal. Samples were analyzed accordingly to a completely randomized design and the main tested effect of model was mPS (n=11, from 0.46 to 3.50mm mPS for Cm or n=10, from 0.11 to 2.98mm mPS for Bm). For both in vitro assays, the rumen inocula were collected from 2 rumen-fistulated Holstein lactating dairy cows fed a total mixed ration with 16.2% crude protein, 28.5% starch, and 35.0% neutral detergent fiber on a dry matter basis. To fit gas production data, 1-pool exponential model and 1-pool or 2-pool Gompertz models were adopted. The rate of gas production decreased and lag increased by increasing mPS of both Cm and Bm, irrespective of adopted 1-pool models. When the 2-pool Gompertz model was used to fit gas production data, a shift of particles from fast to slow fermentable pools was measured by increasing mPS. In particular, the ratio between fast and slow final volumes ranged from 0.90 at 0.11mm mPS to 0.10 at 2.98mm mPS for Bm. For Cm, the ratio between fast and slow final volumes decreased quadratically by increasing mPS, with the highest value (i.e., 0.58) measured at the lowest tested mPS. Values lower than 0.10 were measured for mPS greater than 1.93mm for Cm. Concerning IVSD data, linear decreases in rate of starch degradation equal to −0.049 or −0.092h−1 for each 1-mm increase in mPS were achieved for Cm and Bm, respectively. The 7-h IVSD decreased by 6.3 or 6.5% starch for each 1-mm increase in mPS of Cm or Bm, respectively. Present findings supported the hypothesis that different particle sizes within the same starch source represent an important factor influencing both fermentation kinetic parameters and IVSD.

Palm Jumeirah, Dubai: cone penetrometer testing data from the carbonate sand fill

Palm Jumeirah was the first of the iconic Palm Islands to be reclaimed from the sea off the Dubai coastline. Extensive cone penetrometer testing (CPT) of the hydraulic fill was undertaken, both pre- and post-vibro-compaction, in order to evaluate the effectiveness of the ground improvement. A study of these data, together with standard penetration test (SPT) and shear wave velocity results, is presented for this shelly carbonate sand fill. Large peaks in cone resistance qc were recorded at the start of penetration, which were not considered representative of the undisturbed fill. These were possibly caused by crushing of the friable shelly particles during cone penetration, leading to the formation of a high-density soil plug around the cone. Secondary compression or other ageing mechanism may have occurred at depth in the fill, as well as an apparent longer-term increase in cone resistance with time in the fill above and around groundwater level. However, at a nearby site, in the short term, an apparent decrease in cone resistance with time was observed at the same depth in a similar fill material. In addition, the effect of vibro-compaction point spacing on post-densification CPT results is presented, along with the effect of mean particle size on SPT–CPT correlation.

Effects of Particle Size and Particle Size Distribution on Heat Dissipation of Heat Pipes with Sintered Porous Wicks

Permeability and capillary pressure are the two main characteristics that are frequently referenced in discussing the performances of the sintered wick in a heat pipe. These properties are closely related to the copper powder used. To investigate the effect of mean particle size and particle size distribution on these two properties and the resultant heat dissipation, three gas-atomized Cu powders with different particle sizes, 65, 92, and 128 μm, were examined. The results of thermal performance show that the coarse powder was favorable due to its larger pore size and lower sintered density, which was attributed to the heavier water vapor formation from its high intrinsic oxygen content and the hydrogen atmosphere. The data also showed that powders with narrower particle size distributions result in better thermal performance than those with wide distributions. Since the explanation of the heat dissipation based on the permeability and capillary pressure was not satisfactory, a new method, using capillary speed along with porosity, was applied. This method was shown to be more effective and more practical in evaluating the influence of powder characteristics on the heat dissipation performance of sintered porous wick structures.

Optical and dielectric properties of ZnO‐PVA nanocomposites

AbstractNanocomposites of polyvinyl alcohol and ZnO were prepared using the solution casting method. ZnO nanoparticles with hexagonal wurtzite structure and mean sizes of 59, 82 and 150 nm were prepared by thermal decomposition of zinc acetate dihydrate. The synthesized crystals were characterized by X‐ray diffraction (XRD), and scanning electron microscopy (SEM). Optical properties of the nanocomposites were determined using UV–visible absorption spectroscopy. The results showed that all samples appeared near band edge absorption close to the bulk value. Furthermore, broadband dielectric spectroscopy, at ambient temperature, was employed in order to investigate the effect of mean particle size upon interfacial relaxation phenomena. Dielectric data provide evidence that interfacial polarization, which is present in all three nanocomposite films, shifts to higher frequencies and its intensity is decreasing as the mean nanoparticle diameter is also decreasing. Finally, exploiting the Cole–Davidson approach, becomes evident, that interfacial polarization process acquires a more symmetric form, tending to a pure Debye relaxation. (© 2008 WILEY‐VCH Verlag GmbH &amp; Co. KGaA, Weinheim)

HABITAT USE AND BEHAVIOR OF THE PACIFIC SAND LANCE (AMMODYTES HEXAPTERUS) IN THE SHALLOW SUBTIDAL REGION OF SOUTHWESTERN VANCOUVER ISLAND

The Pacific Sand Lance (Ammodytes hexapterus) is an important Pacific Northwest prey species for marine predators. In our study along the West Coast Trail, southwestern Vancouver Island, British Columbia, we examined shallow subtidal habitat selection of juvenile and adult Sand Lance with respect to sediment characteristics, and also examined aggregation behavior. Analysis of presence or absence using a classification tree showed that Sand Lance avoided sites with no subtidal sediments, preferred sites with mean sediment particle sizes ≤ 1290 μm and preferred mixed sediments (sorting values >3.09 standard deviations; standard deviation of particle size used as a heterogeneity index of the substrate grain size). The regression tree analysis explained 99% of the variation in abundance based on the effects of mean particle size, particle sorting and presence or absence of sediments, but the model showed evidence of over-classification due to small sample sizes. Nevertheless, the model indicated environmental factors that are important for Sand Lance habitat use. Behavioral analysis showed that Sand Lance aggregated into larger schools to feed and these schools tended to occur in the mid-water column compared to non-feeding schools which remained closer to the seafloor. Near the beaches, 0-year (young-of-the-year) Sand Lance were found in deeper water compared to older Sand Lance (1 -year classes). Together these data suggest that Sand Lance using the shallow subtidal show some indication of habitat use based on particle size and sorting, and aggregation differences based on behavior and age class.

Polyiodinated triglyceride lipid emulsions for use as hepatoselective contrast agents in CT: effects of physicochemical properties on biodistribution and imaging profiles.

A novel lipid emulsion (LE) was developed for hepatoselective delivery of a polyiodinated triglyceride (ITG) with potential for use in CT. This work assessed the effects of mean particle size, total administered dose, and formulation composition on the in vivo biodistribution and imaging profiles of the ITG-LE in rats. The concentration of radioactivity derived from intravenously administered 125I-ITG-LE was determined as a function of time after injection. CT imaging studies of the abdomen evaluated the extent of hepatic enhancement after administration of ITG-LE. Mean emulsion particle diameter and total administered dose exerted the greatest effect on ITG-LE biodistribution profiles. In the optimal delivery scenario, >70% of the administered dose localized to the liver 30 minutes after injection. Liver enhancement profiles in CT imaging studies were consistent with biodistribution profiles. These results suggest that an appropriately formulated and administered dose of ITG-LE provides tissue-selective localization of contrast material for use in CT.