Particle Size Distribution Characteristics Research Articles

Approval Research for Carcinogen Humic-Like Substances (HULIS) Emitted from Residential Coal Combustion in High Lung Cancer Incidence Areas of China

The incidence and mortality rate of lung cancer is the highest in Xuanwei County, Yunnan Province, China. The mechanisms of the high lung incidence remain unclear, necessitating further study. However, the particle size distribution characteristics of HULIS emitted from residential coal combustion (RCC) have not been studied in Xuanwei. In this study, six kinds of residential coal were collected. Size-resolved particles emitted from the coal were sampled by using a burning system, which was simulated according to RCC made in our laboratory. Organic carbon (OC), elemental carbon (EC), water-soluble inorganic ion, water-soluble potentially toxic metals (WSPTMs), water-soluble organic carbon (WSOC), and HULIS-C (referred to as HULIS containing carbon contents) in the different size-segregated particulate matter (PM) samples were determined for health risk assessments by inhalation of PM. In our study, the ratio of HULIS-Cx to WSOCx values in RCC particles were 32.73–63.76% (average 53.85 ± 12.12%) for PM2.0 and 33.91–82.67% (average 57.06 ± 17.32%) for PM2.0~7.0, respectively. The carcinogenic risks of WSPTMs for both children and adults exceeded the acceptable level (1 × 10−6, indicating that we should pay more attention to these WSPTMs). Exploring the HULIS content and particle size distribution of the particulate matter produced by household coal combustion provides a new perspective and evidence for revealing the high incidence of lung cancer in Xuanwei, China.

Characterization of Particle Size Distribution of Plasma Lipoproteins in Dairy Cattle Using High-Resolution Polyacrylamide Electrophoresis

Plasma lipoproteins play critical roles in energy metabolism and inflammation. Concentrations of high-density lipoproteins (HDL) are linked to reproductive outcomes and milk yields in dairy cattle. Low-density lipoproteins (LDL), which are enzymatically formed in the blood from very low-density lipoproteins (VLDL) following secretion by the liver, have been used as a surrogate marker of liver function due to the rapid influx of circulating VLDL into the lactating mammary gland. In humans, the composition of plasma lipoproteins is reflected in lipoprotein particle size distribution, and both of these parameters are highly predictive of disease development and related health outcomes. Bovine HDL are overall larger, less dense particles compared to human HDL. Lipoprotein particle size distribution in both health and disease is understudied in the bovine. We hypothesize that a more detailed analysis of lipoproteins could hold diagnostic and/or prognostic value in the study of dairy cattle health and production. In this study, we took the first steps in this characterization and used a high-resolution polyacrylamide gel electrophoretic assay to better define LDL and HDL at the subfraction level in Holstein cows at different stages of lactation. We extensively characterized the lipoprotein particle size distribution in healthy lactating dairy cattle. We identified subfractions of LDL that were prominent only in the dry period and subfractions of HDL that were highest in cows during mid-lactation. Use of this method could be informative in the study of multiple herds and management strategies, including longitudinal evaluation of animals and production parameters.

Regional standardized particle size distributions for developing a Chinese filter testing standard used in building ventilation

The impact of particulate matter (PM) on indoor air quality (IAQ) has become an important issue in China, whereas the standard for the filtration of PM in building ventilation has not been promulgated up to now. Due to the impacts of particle size distribution (PSD) on the particle removal efficiency of the air filters, and also due to the various characteristics of local PSD across China, it is necessary to analyze the selection of PSD when evaluating particle removal efficiency for practical applications. Although the efficiency of PM (ePMX) for various particle size ranges, proposed in the latest EN ISO 16890 standard, is used to evaluate the actual effect of air filters for building ventilation on the improvement of IAQ, it is inappropriate to be adopted for the cases in China. In the present study, fine particle proportion (PM2.5/PM10) is employed and ambient aerosol distributions across China are analyzed. The measured PSDs at 35 cities are fitted to bimodal distribution. And then the ePMX and class reporting values (CRVs) of three representative filters are calculated. The results indicate that being affected by the characteristics of PSD, the ePMX and CRV differences of the same air filter between different PSD regions can be up to about 20% and 15%, respectively. Therefore, the China PSD regions are divided into five regions and the standardized PSD is determined for each region of the mainland.

Characterization of particle size distribution in slurries using ultrasonic attenuation spectroscopy: Addressing challenges of unknown physical properties

Ultrasonic attenuation spectroscopy (UAS) has many advantages in online in-process characterization of particle size distribution (PSD) in slurries. It can be applied to systems with relatively high solid concentration and wide particle size range from nanometres to millimetres sized particles. The model used by a UAS instrument to estimate the PSD from an attenuation spectrum requires some physical properties of both the liquid and solid phases to be known. For instance, the most popular UAS model, the Epstein–Carhart and Allegra–Hawley (ECAH) model, requires fourteen physical properties. Therefore, applications where all or some of the required physical properties are unknown or difficult to measure, such as crystallization, pose a major challenge to its use. In this work, a procedure for estimating the unknown physical properties is proposed. This is done by iteratively learning the unknown physical properties to minimise the difference between the measured attenuation spectra and that predicted by the ECAH model. One of the main challenges of this procedure is the presence of multiple local minima but these can be eliminated by a combination of a global optimisation algorithm, the use of multiple particle size distributions and solid concentrations. The procedure was validated using Silica and Titania standard reference materials, and applied to the estimation of the relevant physical properties of saturated aqueous solution of SrCl2.6H2O and Sr(OH)2.8H2O. The properties thus obtained was used for acoustic monitoring of the real-time evolution of PSD during the batch cooling crystallization of SrCl2.6H2O in water.

Multiphoton induced photoluminescence during time-resolved laser-induced incandescence experiments on silver and gold nanoparticles

In conventional time-resolved laser-induced incandescence (TiRe-LII) measurements, a laser pulse heats the nanoparticles within a probe volume of aerosol, and the particle size distribution and other characteristics are inferred from the observed incandescence decay rate, which is connected to the change in sensible energy through a spectroscopic model. There is strong evidence, however, that for some aerosol systems, the incandescence signal is contaminated with other non-incandescent emission sources. Recent TiRe-LII measurements on polydisperse aerosolized silver and gold nanoparticles energized with a 1064 nm laser pulse exhibit broadband emission that is temporally aligned with the temporal profile of the laser pulse, suggesting that the signal is due to non-thermal emission. One candidate for this emission phenomenon is multiphoton-induced upconversion luminescence, in which the conduction-band electron gas is heated up to an effective lattice temperature, resulting in luminescence due to high-energy intraband transitions.

Nitrogen Sorption Isotherms of Biologically Synthesized Non-stoichiometric Hydroxyapatite Nanoparticles (HAp NPs) Extracted from Fish Bones

Hydroxyapatite (HAp) with the chemical formula of Ca10(PO4)6(OH)2is a mineral component found in bone structure, and has broad application in many fields. Several sources can be used for the extraction of HAp either synthetic or natural. However, sources such as porcine and bovine have drawbacks that decreased the demand of HAp. This study aimed to extract and determine particle size distribution and pore characteristics of hydroxyapatite nanoparticles (HAp NPs) derived from spotted sardinella (Amblygaster sirm). Further characterization of extracted HAp NPs was carried out by Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDS) and Brunauer–Emmett–Teller(BET). SEM analysis has shown that the extracted HApNPs has an irregularsp here-like shape with particle size distribution ranged from 95nm to 100nm.

The relationship between the geochemical and mineralogical characteristics of Calcocambisol, colluvium and recent marine lake sediment of the narrow seashore intertidal zone: a case study from the Veliko Jezero (Mljet Island, Croatia)

This study investigates the mineral composition, particle size distribution and geochemical characteristics of Calcocambisol, colluvium and recent marine lake sediment in a narrow intertidal seashore zone of the Veliko Jezero on the Island of Mljet (Croatia). The obtained results show that the fractions of Calcocambisol/colluvium less than 2 mm and 2 µm display similar particle size distribution (PSD) curves compared to marine lake sediments containing larger particles in these fractions. The smallest fractions of the investigated materials that are less than 1 µm show identical PSD curves. The bulk and clay mineral composition of the marine lake sediment show that the non-carbonate fraction is derived from weathering of the surrounding soils and colluvium containing quartz, feldspars and phyllosilicates (illitic material, kaolinites, chlorite, and a mixed-layer clay mineral, MLCM), as well as the authigenic formation of early-diagenetic pyrite, while one part is related to the yield of material by aeolian deposition (amphibole). The observed difference between the phyllosilicate mineral phases in the clay fraction of the Calcocambisol/colluvium and the carbonate-free clay fraction of the marine lake sediment is related to 1) the presence of chlorite in the marine lake sediment and 2) the higher content of MLCM in the Calcocambisol/colluvium. The chlorite in the marine lake sediment was inherited from the Calcocambisol/colluvium as a result of soil erosion prior to its complete destabilization in the soil. High Chemical Index of Alteration (CIA) values in the Calcocambisol and colluvium clearly indicate their intense weathering. Based on the Sm/Nd and Ti/Al ratios, it can be concluded that the aluminosilicates in the Calcocambisol, colluvium and marine lake sediment are of the same provenance. The distribution of each analysed element among the sequential fractions is very similar in both the Calcocambisol and colluvium. The highest concentrations for most of trace elements in the Calcocambisol, colluvium and marine lake sediment was determined in their residual fraction. Mn, Co and Pb show a different partitioning between the Calcocambisol/colluvium and marine lake sediment, respectively.

Characteristics of Particle Size Distributions of Falling Volcanic Ash Measured by Optical Disdrometers at the Sakurajima Volcano, Japan

In the present study, we analyzed the particle size distribution (PSD) of falling volcanic ash particles measured using optical disdrometers during six explosive eruptions of the Sakurajima volcano in Kagoshima Prefecture, Japan. Assuming the gamma PSD model, which is commonly used in radar meteorology, we examined the relationships between each of the gamma PSD parameters (the intercept parameter, the slope parameter, and the shape parameter) calculated by the complete moment method. It was shown that there were good correlations between each of the gamma PSD parameters, which might be one of the characteristics of falling volcanic ash particles. We found from the normalized gamma PSD analysis that the normalized intercept parameter and mass-weighted mean diameter are suitable for estimating the ash fall rate. We also derived empirical power law relationships between pairs of integrated PSD parameters: the ash fall rate, the volcanic ash mass concentration, the reflectivity factor, and the total number of ash particles per unit volume. The results of the present study provide essential information for studying microphysical processes in volcanic ash clouds, developing a method for quantitative ash fall estimation using weather radar, and improving ash transport and sedimentation models.

Effect of Grinding Time on the Particle Size Distribution Characteristics of Tuff Powder

We study the grinding dynamic behavior and particle size distribution (PSD) characteristics of tuff powder. With the analysis of particle size and data of activity test, the results indicate that tuff powder is easy to be ground for the coarse-grained while is difficult for the fine-grained. It is feasible to quantitatively express the milling process of tuff powder by Divas-Aliavden milling dynamic equation. The milling speed and the milling time are negatively correlated, and the grinding efficiency is minimized after 60 min. Equivalent particle size (EPS) is positively linearly correlated with the logarithm of grinding time, while specific surface area (SSA) is inversely correlated, both of them have a highly linear correlation. The PSD of tuff powder, which complies well with the Rosin-Rammler-Bennet (RRB) distribution model, has typical fractal characteristics, and its fractal dimension is also positively correlated with the milling time.

Influence of Water Quality on the Flue Gas Desulfurization in a 350MW Coal-fired Power Plant

With the national ultra-low emission requirements, a large number of wet flue gas desulfurization has been used in the normal operation of coal-fired power plants. After long-term operation, various impurities will be enriched in the slurry of absorption tower, resulting in the reduction of desulfurization efficiency or foaming of the slurry of absorption tower, which will seriously affect the operation of the unit. It is necessary to study the influence of water quality on the desulfurization reaction of lime slurry. When the incoming water is reclaimed water, process water and filtrate respectively, the desulfurization reaction is simulated on the laboratory bench to compare its influence on the desulfurization reaction characteristics. The results show that. (1) The effect of process water on the desulfurization process is as follows. The largest amount of foaming of the desulfurization slurry and the inhibition of gypsum crystallization reaction, but the characteristics of particle size distribution in the generated gypsum slurry are most conducive to the slurry dehydration and the gypsum crystal quality is good. (2) The function of the filtrate is to minimize the foaming amount of the desulfurized slurry and the effect on the gypsum crystallization reaction. The characteristics of particle size distribution in the generated gypsum slurry are favorable for the slurry dehydration. The gypsum crystal size is the largest, but a small number of crystal particles appear at the same time, which affects the slurry dehydration to a certain extent. (3) The role of reclaimed water lies between process water and slurry.

Study on the particle size distribution characteristics and cementitious activity of different fineness components in cement

In order to obtain the change law of the cementitious activity of the different fineness components in the Portland cement, the cement was classified by the air classifier and six components with different fineness were obtained. The particle size distributions of the six components were measured and their cementitious activities were evaluated. The results show that the cement powder obtained by classification basically conforms to the distribution model of Rosin-Rammler-Bennet equation. The fluidity of the mortar of different fineness components in cement does not change significantly with the change of fineness. The greater the fineness of each component is, the higher the early strength of their mortar test will be, but as the curing age increases, the strength increase is not obvious. The sample obtained by mixing three finer-grained components has the highest mortar compressive strength in the early age, and the strength increase in the later age is stable.

Characteristics of Powders from Different Aluminum Alloys for Additive Technologies Obtained by Gas Atomization

Selective laser melting (SLM) is one of the additive manufacturing technologies that allows us to produce complex shape metallic objects from powder feedstock. Al-alloys are very promising materials in selective laser melting. In this paper, atomized metal powders of various aluminum alloys are investigated: 1) deformable alloys АК4, АК6; 2) cast alloys АК9ph, АК12; 3) deformable hardened alloy D16. As a part of the work, the particle shape, particle size distribution and technical characteristics of the powders were investigated, and also the compliance of materials with the requirements of additive technologies (SLM) was determined.

Modeling the Production Technology of Fully-Pressed Bi-Metal Powder Materials and Products

The features of calculating the thickness of the layers of bimetallic powder products without holes and the type of bushings are shown. The effect of the particle size distribution of the powders, the kinematic and geometric parameters of the loading devices and molds on the mechanism of the expiration of the powder mixture and on the thickness of the layers of the molded product is studied. A technique has been developed for determining the dimensions of the feeder cassette and tooling, depending on the overall dimensions and thicknesses of the working layers, in the production of whole-pressed bimetallic products on press machines with a vertical arrangement of layers. It was found that the thickness of each layer of bimetallic products depends on the geometric parameters of the feeder cassette and tooling, bulk density, particle size distribution and other characteristics of the powders, as well as on the speed of lowering the lower punch ν1 .

Determination Method and Characteristics of Particle Size Multiplier of PM2.5 in Road Dust

The particle size multiplier is a valuable parameter for depicting the particle size distribution characteristics of road dust and calculating road dust emissions. In order to realize the localization of the particle size multiplier, the AP-42 and TRAKER methods were used for sampling on typical and different types of roads in Baoding in March 2019. Then, the particle size multiplier of road dust PM2.5 (K2.5) was calculated using the correction formula, and the characteristics were analyzed. The results indicated:① The K2.5 obtained separately by AP-42 and TRAKER were 0.21 g·VKT-1 and 0.23 g·VKT-1 on average, which correlated well, with a high correlation coefficient of 0.6. The PM2.5 emission factors calculated using the K2.5 of the different methods were almost at the same value, indicating that TRAKER method based on a laser sensor could measure and calculate the K2.5 and could be directly used to obtain the particle size multiplier or be converted using the fitting equation. ② The characteristics of the K2.5 in Baoding were ranked as:Expressway<Secondary roads<Branch roads<Major Roads. ③ Further study results of K2.5 characteristics demonstrated that the average K2.5 was higher than 0.15 g·VKT-1 (the value recommended by US EPA) in Baoding City, which would cause an underestimate of road dust emissions and increase the uncertainty of the emissions inventory if the recommended value from the EPA were adopted. The K2.5 in Baoding City is relatively high, indicating that the road dust contains a significant number of micro particles, increasing the contribution of road dust to urban atmospheric PM2.5.

Distribution of microplastics in mulched soil in Xinjiang, China

In order to study the distribution of soil microplastics in the plastic film mulched farmland, the fluidization-centrifugation secondary density flotation method was optimized and improved to obtain the samples. The main components of microplastics were analyzed by Fourier spectrometer, and the surface morphology, porosity, particle size and abundance distribution characteristics of microplastics were studied by electron microscopy. The results showed that plastic mulch is the main source of microplastics. Its morphology mainly consists of fragments, fibers and particles. The size of debris microplastics was larger, with an average of 1.6300 mm, mainly distributed in the 0-300 mm cultivation layer while the size of particle micro plastic was smaller, with an average of 0.1400 mm. The width of fiber microplastic was 5-20 μm, but the length could reach 0.2000-2.0000 mm, with an average particle size of 0.9200 mm. Fiber and granular microplastics could be seen in each soil layer. The surface layer of microplastics has a large number of pores characterized with a length of 50 μm and a width of about 5-10 μm, which might be an easy oxidation site for microplastics. This oxidation is continuous, making microplastics continuously decompose into smaller particles. The abundance of microplastics is negatively correlated with soil depth. The average abundance of microplastics is 161.50±5.20 pieces/100 g in 0-300 mm soil layer, which is their main enrichment area. However, the average abundance of microplastics decreases to 11.20±1.10 pieces/100 g in 400-800 mm soil depth. Moreover, the average particle size of microplastics is also linearly negatively correlated with soil depth. Microplastics with smaller particle size are easier to migrate as they pass through soil pores under the action of water and fertilizer. The research can provide s reference for understanding plastic mulch pollution. Keywords: soil microplastics, plastic pollution, distribution, composition DOI: 10.25165/j.ijabe.20211402.6165 Citation: Hu C, Lu B, Guo W S, Tang X Y, Wang X F, Xue Y H, et al. Distribution of microplastics in mulched soil in Xinjiang, China. Int J Agric & Biol Eng, 2021; 14(2): 196–204.

Concentration and Particle Size Distribution Characteristics of Microbial Aerosol and Bacterial Community Structure During Spring in Lanzhou City, China

The aim of this study was to analyze the differences in the concentration, particle size, and bacterial community structure of microbial aerosols and further investigated the effects of meteorological conditions and air pollutants on microbial aerosol distribution at different periods during spring in Lanzhou. The results showed that the average aerosol concentrations of total microbes, bacteria, fungi, and actinomycetes in the air environment of Lanzhou were (2730±376), (2243±354), (349±38), and (138±22) CFU·m-3, respectively. The contribution rate of bacteria was 82.16%, which was significantly higher than that of fungi and actinomycetes (P<0.05). The concentrations of total microorganisms, bacteria, and actinomycetes during 08:00-09:00 were significantly higher than those sampled during 18:00-19:00, indicating that meteorological conditions and air pollutants have a remarkable influence on the concentration of microbial aerosols. Aerosol particles of bacteria and fungi were primarily distributed at the first four levels (>2.1 μm), accounting for 85.13% and 83.26%, respectively, while 73.15% of the actinomycetes aerosol particles focused largely on the latter four stages (<4.7 μm). Illumina MiSeq sequencing results indicated that there was no significant difference in the composition of the bacterial community (P>0.05) during the periods of 08:00-09:00 and 18:00-19:00. Lactococcus and Bacillus were the dominant bacteria genus. Enterococcus, Staphylococcus, Pseudomonas, Acinetobacter, Klebsiella, Erwinia, Bacillus cereus, Streptococcus agalactiae, and Clostridium perfringens were potential pathogens detected in the air environment of Lanzhou in the spring. The results could provide fundamental data for further revealing the contamination status of microbial aerosols and the potential harm of the related pathogenic bacteria to human health during the spring in Lanzhou.

Exploring the potential benefits of high-efficiency dual-fuel combustion on a heavy-duty multi-cylinder engine for SuperTruck I

In support of the Daimler SuperTruck I team’s 55% brake thermal efficiency (BTE) pathway goal, researchers at Oak Ridge National Laboratory performed an experimental investigation of the potential efficiency and emissions benefits of dual-fuel advanced combustion approaches on a modified heavy-duty 15-L Detroit™ DD15 engine. For this work, a natural gas port fuel injection system with an independent injection control for each cylinder was added to the DD15 engine. For the dual-fuel strategies investigated, 65%–90% of the total fuel energy was supplied through the added port fuel injection natural gas (NG) fueling system. The remaining fuel energy was supplied by one or more direct injections of diesel fuel using the production high pressure diesel fueling system. The production DD15 air handling system and combustion geometry were unmodified for this study. Efficiency and emissions with dual-fuel strategies including both low temperature combustion (LTC) and non-LTC approaches such as dual fuel direct-injection were investigated along with control authority over combustion phasing. Parametric studies of dual-fuel NG/diesel advanced combustion were conducted in order to experimentally investigate the potential of high-efficiency, dual-fuel combustion strategies to improve BTE in a multi-cylinder engine, understand the potential reductions in engine-out emissions, and characterize the range of combustion phasing controllability. Characterization of mode transitions from mixing-controlled diesel pilot ignition to kinetically controlled ignition is presented. Key findings from this study included a reproducible demonstration of BTE approaching 48% at up to a 13-bar brake mean effective pressure with significant reductions in engine-out NOx and soot emissions. Additional results from investigating load transients in dual-fuel mode and initial characterization of particle size distribution during dual-fuel operation are presented.

Particle size distribution and pollutant dissolution characteristics of road-deposited sediment in different land-use districts: a case study of Beijing.

The high pollutants loading of road-deposited sediment (RDS) make it the main threat to receiving water bodies in stormwater management; however, the characteristics of RDS have not yet been sufficiently studied. In this study, samples were collected from three different land-use type areas (campus, residential, and commercial) in Beijing, China, and analyzed for particle size distribution, chemical compositions, and dissolution characteristics. The results revealed that RDS in the sampling sites mainly consisted of particles < 63 μm, which accounted for 40.3%, 30.5%, and 30.3% of the total in samples from campus, residential, and commercial sites, respectively. In addition, the mass percentage of sediments decreased with increasing particle size in all three sampling sites. The highest pollutants loading were mainly found in particles between 125 and 250 μm. The pollutant loading occurred in the following order: commercial > residential > campus for COD and heavy metals (Cr, Cd, Pb, Cu), and campus > residential > commercial for TN, NH4+-N, and PO43--P. The pollutants dissolved capacity (DC) and pollutants dissolved velocity (DV) both decreased with increasing particle size. Overall, the results of this study highlight the importance of removing fine particles to controlling road runoff pollution.

Size distribution and chemical characteristics of particles from crop residue open burning in North China

Crop residue open burning is an important emission source of ambient particles in China. This study analyzed the particle emission characteristics of crop residue open burning through combustion experiments with a novel open combustion simulation device using three typical crop straws in north China (corn, wheat, and rice). Particle samples size ranging from 0.006–9.890 µm were collected by an Electrical Low Pressure Impactor plus, a high size-resolution instrument capable of dividing particles into 14 size stages. The size distributions of organic carbon (OC), elemental carbon (EC), water-soluble ions, and elements were analyzed, and source chemical profiles were constructed for PM0.1, PM1, PM2.5, and PM10. The number concentration of particles was concentrated in the Aiken nuclei mode (0.006–0.054 µm), accounting for 75% of the total number, whereas the mass concentration was concentrated in the accumulation mode (0.054–0.949 µm), accounting for 85.43% of the mass loading. OC, EC, Cl−, and K(include total K and water-soluble K) were the major chemical components of the particles, whose mass percentage distributions differed from those of other components. These five main components exhibited a bell-shaped size distribution in the 0.006–9.890 µm range, whereas the other components exhibited a U-shaped distribution. Among the chemical profiles for PM0.1–PM10, OC was the most important component at 10–30%, followed by EC at 2%–8%. The proportions of K+, Cl−, and K varied substantially in different experimental groups, ranging from 0–15%, and K+ and Cl− were significantly correlated (r = 0.878, α = 0.000).

Experimental study on particle size distribution of gasoline compression ignition (GCI) at low-load condition

A modified single-cylinder test engine was utilized in this study to figure out the effects of injection timing, exhaust gas recirculation (EGR) and Polyoxymethylene dimethyl ethers (PODE) additive on particle size distribution characteristics. The study was performed under gasoline compression ignition (GCI) mode, whose injection timing range was varied from −22 to −10 °CA ATDC under the examined condition, and particle size distributions were measured by an exhaust particle size spectrometer TSI EEPS 3090. The results showed that, the nuclei-mode highly dominates the particle size distribution, and the particle size corresponded to peak particle number tends to be uniformly distributed around 20 nm regardless of the combustion control parameters and fuel properties. A unimodal distribution is appeared without and with EGR, while the particle size distribution shifts to the larger size and peak particle number is lower with the advance of injection timing. Compared with the no EGR case, an overall increase of particle number can be observed by applying EGR. Furthermore, the peak particle number and particle number concentration can be greatly reduced by more than two orders of magnitude by adding 10% PODEn, but further increasing blending ratio of PODEn to 20% has much less effect. In a last step, indicated specific particle number (ISPN) was analyzed, suggesting that the ISPN of both total particles and particles smaller than 50 nm exhibits increase first and then decrease with the increase of EGR. Overall, the particle number control of GCI mode should be based on the well matching of combustion control parameters and fuel properties.