Range Of Size Distribution Research Articles

Comparative Study on the Generation and Characteristics of Debris Induced by Fretting and Sliding.

Objectives: The aim of the present work was to comparatively investigate the generation and characteristics of fretting and sliding wear debris produced by CuNiAl against 42CrMo4. Methods: Tribological tests were conducted employing a self-developed tribometer. Most experimental conditions were set the same except for the amplitudes and number of cycles. Morphological, chemical, microstructural and dimensional features of the worn area and debris were investigated using optical microscope (OM), X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS) and a laser particle sizer. Outcomes: Not only wear scar profiles but also the wear debris color, distribution and generated amount under fretting and sliding wear modes were quite different, which can be attributed to the significant difference in wear mechanisms. Particle size analysis indicates that the fretting debris has a smaller size distribution range; the biggest detected fretting and sliding wear debris sizes were 141 μm and 355 μm, respectively. Both fretting and sliding debris are mainly composed of copper and its oxides, but the former shows a higher oxidation degree.

Macrophage-Derived Extracellular Vesicles: A Promising Tool for Personalized Cancer Therapy.

The incidence of cancer is increasing dramatically, affecting all ages of the population and reaching an ever higher worldwide mortality rate. The lack of therapies’ efficacy is due to several factors such as a delay in diagnosis, tumor regrowth after surgical resection and the occurrence of multidrug resistance (MDR). Tumor-associated immune cells and the tumor microenvironment (TME) deeply affect the tumor’s progression, leading to several physicochemical changes compared to physiological conditions. In this scenario, macrophages play a crucial role, participating both in tumor suppression or progression based on the polarization of onco-suppressive M1 or pro-oncogenic M2 phenotypes. Moreover, much evidence supports the pivotal role of macrophage-derived extracellular vesicles (EVs) as mediators in TME, because of their ability to shuttle the cell–cell and organ–cell communications, by delivering nucleic acids and proteins. EVs are lipid-based nanosystems with a broad size range distribution, which reflect a similar composition of native parent cells, thus providing a natural selectivity towards target sites. In this review, we discuss the impact of macrophage-derived EVs in the cancer’s fate as well as their potential implications for the development of personalized anticancer nanomedicine.

Gelatin Stabilizes Nebulized Proteins in Pulmonary Drug Delivery against COVID-19.

Delivering medication to the lungs via nebulization of pharmaceuticals is a noninvasive and efficient therapy route, particularly for respiratory diseases. The recent worldwide severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) pandemic urges the development of such therapies as an effective alternative to vaccines. The main difficulties in using inhalation therapy are the development of effective medicine and methods to stabilize the biological molecules and transfer them to the lungs efficiently following nebulization. We have developed a high-affinity angiotensin-converting enzyme 2 (ACE2) receptor-binding domain (RBD-62) that can be used as a medication to inhibit infection with SARS-CoV-2 and its variants. In this study, we established a nebulization protocol for drug delivery by inhalation using two commercial vibrating mesh (VM) nebulizers (Aerogen Solo and PARI eFlow) that generate similar mist size distribution in a size range that allows efficient deposition in the small respiratory airway. In a series of experiments, we show the high activity of RBD-62, interferon-α2 (IFN-α2), and other proteins following nebulization. The addition of gelatin significantly stabilizes the proteins and enhances the fractions of active proteins after nebulization, minimizing the medication dosage. Furthermore, hamster inhalation experiments verified the feasibility of the protocol in pulmonary drug delivery. In short, the gelatin-modified RBD-62 formulation in coordination with VM nebulizer can be used as a therapy to cure SARS-CoV-2.

Stumbling over Planetary Building Blocks: AU Microscopii as an Example of the Challenge of Retrieving Debris-disk Dust Properties

We explore whether assumptions about dust grain shape affect the resulting estimates of the composition and grain size distribution of the AU Microscopii (AU Mic) debris disk from scattered-light data collected by Lomax et al. The near edge-on orientation of the AU Mic debris disk makes it ideal for studying the effect of the scattering phase function on the measured flux ratios as a function of wavelength and projected distance. Previous efforts to model the AU Mic debris disk have invoked a variety of dust grain compositions and explored the effect of porosity, but did not undertake a systematic effort to explore a full range of size distributions and compositions to understand possible degeneracies in fitting the data. The degree to which modeling dust grains with more realistic shapes compounds these degeneracies has also not previously been explored. We find differences in the grain properties retrieved depending on the grain shape model used. We also present here our calculations of porous grains of size parameters x = 0.1 to 48 and complex refractive indices (m = n + iκ) ranging from n = 1.1 to 2.43 and k = 0 to 1.0, covering multiple compositions at visible and near-infrared wavelengths such as ice, silicates, amorphous carbon, and tholins.

Applicable scope of estimation of three-dimensional particle size distribution by the Goldsmith-Cruz-Orive and improved methods

Microscopic observation is commonly performed on particle sections when the internal structure and/or inclusion is of interest in a given field, and the particles in question include sand, grain, cell, void, crystal, etc. components for example. However, in practice, the particle size distributions determined by two-dimensional (2D) observation of particle sections differ from the actual three-dimensional (3D) particle size distributions, due to the stereological difference between 2D and 3D observation. Among the various methods of estimating 3D from 2D size distributions, the Goldsmith-Cruz-Orive method (GCO) is known to provide high estimation accuracy. In this study, the GCO and a newly improved GCO method (MGCO) were systematically investigated to determine their applicable scope in terms of the range of size distributions, unusually-shaped (step-like) size distributions, the axis length ratio of ellipsoidal particles, and input data errors. Among the study's results, the MGCO method showed greater estimation accuracy than GCO irrespective of the range of size distributions, reasonable estimation accuracy in the case of step-like size distributions (while GCO did not), greater robustness than GCO with respect to the axis length ratio of ellipsoidal particles, and more sensitivity to input data errors than GCO. Elucidation of the applicable scopes of the respective methods facilitates the practical use of the GCO methods for various types of particles.

농장비 설계를 위한 한국 척수장애인의 대표 인체모델군 개발

Korea’s agriculture is facing a manpower shortage due to a decrease in the population and an aging workforce. Involving disabled people in agriculture as a solution to the problem of manpower shortage can help both agricultural workers and people with disabilities, and for this purpose, it is necessary to develop agricultural tools that disabled people can use in agricultural tasks. This study was intended to create a representative human body model used in the anthropometric design of agricultural tools for people with spinal cord disabilities. This study used the existing anthropometric data for the spinal cord disabled and created a representative human body model using the method of boundary for the accommodation range of the body size distribution. As a result of factor analysis, 26 body dimensions were reduced to 4 factors, and the representative group had 16 body models to have an accommodation rate of 90% of the distribution. As a result of the evaluation of the accommodation rate of the representative human model group, only 42% of cases satisfied all the ranges of 26 body dimensions for the representative group, but 88% of cases satisfied all the ranges of 23 body dimensions, which is close to the target rate. The representative human model group for spinal cord disabilities was visualized using the Tecnomatix human model module. This can be utilized in identification of problems with existing agricultural tools and anthropometric design for the disabled.

Geographical range overlap networks and the macroecology of species co-occurrence.

Direct interactions among species are only possible if there is some overlap in their geographical distributions. However, despite intense focus of macroecological research on species geographical ranges, relatively little theoretical and empirical work has been done on the evolution of range overlap. In this study we explore a simple model of range overlap based on a log-normal distribution of species range sizes along a one-dimensional domain, with or without absorbing boundary conditions. In particular, we focus on the mean and variance of range overlap distributions, as well as the topology of the resulting overlap networks with respect to their degree distribution, evenness, and betweenness scores. According to the model, there is an approximately linear relationship between many aspects of the distribution of range overlaps and their underlying species distributions, such as their mean and variance. However, the expected mean number of non-zero range overlaps for a given species varied from linear to convex depending on the variance of the underlying geographical range distribution. The expected topology of range overlap networks varied substantially depending on the mean and variance in the corresponding geographical distributions, particularly in the case of the degree and closeness distributions. Finally, we test the expectations of our model against five datasets of altitudinal distributions of Neotropical birds. We found strong departures from the expectations based on our model, which could potentially result from phylogenetic niche conservatism related to altitudinal gradients in environmental conditions, or from the asymmetric colonization of mountains by species from lowlands. Potential applications of range overlap networks to a variety of ecological and evolutionary phenomena are discussed.

Green Synthesis of Silver Nanoparticles (AgNPs), Structural Characterization, and their Antibacterial Potential.

BackgroundIn the field of nanotechnology, the metallic nanoparticles are of remarkable interest because of their unique electronic, magnetic, chemical, and mechanical properties.Purpose:In the present work, silver nanoparticles (AgNPs) were synthesized using bio-reduction method. Research Design:Silver nitrate was used as metallic precursor and the extract of Moringa oleifera leaves with different concentrations was used as reducing as well capping agent. The extract exhibited strong potential in rapid reduction of silver ions for the synthesis of silver nanoparticles. The synthesized silver nanoparticles were characterized by UV-visible spectroscopy, X-ray diffraction (XRD), and scanning electron microscopy (SEM) techniques.Results:The absorption SPR peaks appeared in the range of 415 to 439 nm. SEM analysis exhibited that particles were spherical in shape with size distribution range from 10 nm to 25 nm. The synthesized silver nanoparticles were pure crystalline in nature as confirmed by the XRD spectra with average crystallite size 7 nm. In vitro antibacterial activity of the prepared silver nanoparticles colloidal samples as well the extract was studied using different concentrations of AgNPs (C1 = 100 μg/ml, C2 = 50 μg/ml, C3 = 25 μg/ml) by well diffusion method against Gram negative Escherichia coli. The antibacterial performance was assessed by measuring the zone of inhibition (ZOI). ConclusionsThe results suggested that AgNPs prepared by green approach can be considered as an alternative antibacterial agent.

Amphipathic anionic surfactant modified hydrophilic polyethylene glycol-nanosilica composite as effective viscosifier and filtration control agent for water-based drilling muds

Highly stabilized and dispersible composites of polyethylene glycol and silica nanoparticle in aqueous drilling mud can provide desirable rheological and filtration properties for drilling jobs. Therefore, high-quality hydrophilic polyethylene glycol-nanosilica composite modified by amphipathic anionic sodium dodecyl sulfate (PEG-SiO2 NC-SDS) to improve the rheological and filtration properties of water-based muds (WBMs) was submitted. Test of zeta potential, functional groups, morphology, elemental composition, and temperature stability together with rheology and filtration tests were undertaken to assess the wide-ranging mud properties of the SDS modified PEG-SiO2 NC drilling muds. Zeta potential, FTIR, FESEM, EDX, and TGA results indicate that the SDS modified PEG-SiO2 NC was effectively formed and modified; it embodies exceptional thermal stability and is efficiently dispersed. The SDS modified PEG-SiO2 NC has a narrow size distribution range between 82 nm and 410 nm, and a specific surface area of 41.4 m2/g that is sufficiently high for particle-molecule interactions. Its rheological variables are notably shear-thinning and did not undergo notable fluctuation. The filtrate loss of 1.5 g SDS bearing PEG-SiO2 NC at 78 °F and 250 °F was only 5.4 ml and 9.6 ml, against 10.2 ml and 20.5 ml of the WBMs, respectively. High dispersion stability and high thermal stability aided its excellent viscosity and filtration control performance. Moreover, optimum rheological properties for the SDS modified PEG-SiO2 NC drilling muds with Bingham plastic and Ostwald-de-Waele models occurred with mud composition CD3 (CD3 = 1.5 g SDS modified PEG-SiO2 NC + WBM). Thus, this study can help to understand the applications of this nanocomposite as a potential viscosifier and filtrate loss control material for WBMs.

Recycling of Broken Waste Glass as Polyethylene Nanofiller for Electrical Insulating System

This work focuses on the preparation of a high-quality glass powder from the broken windowpane. The expected glass powder must show a high amount of silicon dioxide with fine particle size. The processing technique used in this work is coarse grinding and high-speed vibratory milling under a variety of conditions to get the best quality of glass powder. The particle size and particle size distribution were examined by using DLS technique. The chemical composition was examined by EDX together with FT-IR and XRF spectroscopies. The results showed that the wide range of particle size distribution occurred in all milling conditions, which approximately ranged from 0.3 to 7 µm, and the 270 min-milling time showed the smallest particle size of glass powder. The chemical analysis showed that the glass powder is rich in silica which contained about 70.47% of SiO2. After that, the various ratios of the glass powder/HDPE composites were formed by using the traditional casting method. The physical and electrical properties were investigated for all composites. The results showed that after adding glass powder into the HDPE matrix, the εr value significantly drops due to the inorganic filler suppressed polarization within the systems. For the resistivity, the ρ value significantly increases after adding glass powder to the HDPE matrix for all compositions because this filler promotes the hinder of electric current flow. Finally, it can conclude that the waste glass powder can use as a filler in the HDPE-based composite as better as the commercial SiO2 powder for the electrical insulting application.

Fabrication and Characterization of Bioactive Gelatin-Alginate-Bioactive Glass Composite Coatings on Porous Titanium Substrates.

In this research work, the fabrication of biphasic composite implants has been investigated. Porous, commercially available pure Ti (50 vol % porosity and pore distributions of 100–200, 250–355, and 355–500 μm) has been used as a cortical bone replacement, while different composites based on a polymer blend (gelatin and alginate) and bioactive glass (BG) 45S5 have been applied as a soft layer for cartilage tissues. The microstructure, degradation rates, biofunctionality, and wear behavior of the different composites were analyzed to find the best possible coating. Experiments demonstrated the best micromechanical balance for the substrate containing 200–355 μm size range distribution. In addition, although the coating prepared from alginate presented a lower mass loss, the composite containing 50% alginate and 50% gelatin showed a higher elastic recovery, which entails that this type of coating could replicate the functions of the soft tissue in areas of the joints. Therefore, results revealed that the combinations of porous commercially pure Ti and composites prepared from alginate/gelatin/45S5 BG are candidates for the fabrication of biphasic implants not only for the treatment of osteochondral defects but also potentially for any other diseases affecting simultaneously hard and soft tissues.

Synthesis and Characterization of ZnO Nanoparticles

This study is focused on hydrothermal synthesis method of zinc oxide nanoparticles by usingammonia and zinc chloride. Synthesized nanoparticles have been characterized by using Xray Diffraction, UV-vis and Photon Cross Correlation (PCCS) spectroscopies, TEManalysis. ZnO thin films were prepared by spin coating method from the solution of ZnOnanoparticles. XRD peak corresponds to hexagonal structure with cell parameter a=0.326nm and c=0.522 nm. The grain size of zinc oxide nanoparticles has been determined 43.3nm using the Scherrer formula. As a result of PCCS measurement, synthesized zinc oxidenanoparticles have the mean diameter of ~96 nm of main particles with particle sizedistribution range of from ~90 nm to ~99 nm. As the result of TEM, the respective size ofnanoparticles was around ~96 nm. ZnO nanoparticles were coated on glass and indium-tinoxide (ITO) substrates. The photocatalytic activities were studied ITO substrates with ZnOthin film. ZnO thin films were used as catalyst for reaction Cr(VI) into Cr(III).

DEVELOPMENT OF NILOTINIB LOADED SOLID LIPID NANOPARTICLES AND OPTIMIZATION BY CENTRAL COMPOSITE DESIGN APPROACH

Objective: In current research, solid lipid nanoparticles (SLN) are formulated for the anticancer drug, nilotinib, to conquer the drawbacks associated with drug including low bioavailability and solubility. Methods: The formulation comprised of tripalmitin (lipid), poloxamer 188(surfactant) and glyceryl palmitostearate (cosurfactant) by solvent evaporation technique. The formulation and process variables of SLN were optimized by experimental design-Central composite design (CCD). The effect of drug to lipid ratio (A), concentration of Poloxamer 188 (B) and concentration of glyceryl palmitostearate(C), on particle size (Y1) and encapsulation efficiency (Y2) of SLN were evaluated. Three batches (F1-F3) of Nilotinib SLNs were formulated by desirability approach and evaluated. Results: The mean size of all the formulations ranged between 187–198 nm, PDI between 0. 291-0.652 and zeta potential between-21.8 to to-24.7 mV indicating the wide range of size distribution and stabiliity of the formulations. The total encapsulation efficiency of SLNs ranged between 85 to 86 %. The SEM analysis revealed the spherical shape of individual particles and PXRD results indicate amorphization of drug in SLN formulation. The drug release was continued for 24 h, indicative of controlled release drug delivery. Conclusion: From the above results it is concluded that the solubility and bioavailability of nilotinib is enhanced.

Characterization of Ancient Burial Pottery of Ban Muang Bua Archaeological Site (Northeastern Thailand) Using X-ray Spectroscopies

Ancient potteries found at Ban Muang Bua, located in northeastern Thailand, associate with Thung Kula Ronghai culture. Most of them are products used in daily life and grave goods. The potsherds were examined using techniques based on X-ray spectroscopy. Elemental composition and morphology were analyzed using proton-induced X-ray emission spectroscopy (PIXE) and scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDS). Three-dimensional analysis was performed using X-ray tomographic microscopy based on synchrotron radiation (SR XTM). Irregular plate-like particles of composites with a wide range of size distribution were found in the potsherds. The major (O, Si, and Al), minor (C, Fe, Ca, and K), and trace elements (P, S, Ti, Na, Mg, and Zn) which were observed can provide the information about raw materials and production of pottery. The 3D tomographic images show the internal feature of these samples. The combination of SEM-EDS, PIXE, and SR XTM is a powerful tool for archaeological research especially in terms of composition and internal structure. The results imply that the raw materials of pottery were sandy soil derived from marine sands, clays, and salt deposits that were mostly iron-rich-kaolin clay. The production was carried out with low firing temperatures (~600–900 °C) in open-air kilns.

Analysis of the compressibility of edible powders under low pressure

Appropriate compression of edible powder is very beneficial to the powder itself and the industrial production, but the law and mechanism of the influence of various factors on the compressibility of powder are not clear. Therefore, this study was used uniaxial confined real compression experiments to separately study the influence law of particle size distribution, moisture content and static friction angle on powder compressibility. Through uniaxial confined compression real and simulation experiments, combined with powder particle size distribution experiment, powder moisture content measurement experiment, powder angle of repose experiment and powder static friction angle experiment, the internal mechanism of different factors affecting powder compressibility was analyzed. The results show that the compressed volume of powder increases logarithmically with the increase of pressure. The higher the moisture content of the powder (11%, 14%, 18%), the larger the void content, the worse the fluidity and the compression curve of high moisture content is always above that of the low moisture content (The average difference of amount of compression was 3.24%). The larger the particle size distribution range of the powder, the larger the void content, the better the fluidity and the compression curve of wheat flour is always above the wheat starch (The average difference of amount of compression was 3.08%). When using different containers, the larger the static friction angle between powder and container, the greater the static friction between powder and container (the compression resistance of the powder) and the worse the compressibility, but the effect on the compressibility is small (The compressibility gap of powder in different containers is within 0.7%.).

In-vitro characterization and evaluation of mesoporous titanium dioxide composite hydroxyapatite and its effectiveness in occluding dentine tubules

BackgroundTo synthesize mesoporous titanium dioxide composite hydroxyapatite (TiO2–HAP) and to evaluate its effectiveness in sealing of occluding dentine tubules.MethodsTiO2–HAP was synthesized by chemical precipitation method and characterized using infrared absorption spectrometer, X-ray diffraction, scanning electron microscope, and specific surface area detector. Forty completely extracted molars were prepared and randomly assigned into Control group, Gluma group, HAP group and TiO2–HAP group according to different treatments. The characteristics of HAP and TiO2–HAP and the sealing effectiveness of dentine tubules in these four groups, including infrared spectrum, surface contact angle, pore size distribution, and re-mineralized enamel surface profiles, were analyzed by suitable characterized techniques. The cytotoxicity of the synthesized TiO2–HAP was tested and compared using 3-(4,5)-dimethylthiahiazo(-z-y1)-3,5-di-phenytetrazoliumromide (MTT) colorimetry.ResultsOur results showed TiO2–HAP group had significantly lower contact angle, higher specific surface area, and wider range of pore size distribution than other groups. The majority of dentinal tubules in the TiO2–HAP group were blocked by white matter in a uniformed manner, and the crystals arranged in order grew along the axial direction. In addition, no significant difference in optical density (OD) value was found between control group and TiO2–HAP group (P > 0.05), and cell growth was good in TiO2–HAP group, indicating no cytotoxicity of TiO2–HAP.ConclusionsThe MTT assay identified that TiO2–HAP had little effect on the L929 cell line. We showed TiO2–HAP might be used as a remineralization agent in enamel caries-like lesions.

Splicing Method of Micro-Nano-Scale Pore Radius Distribution in Tight Sandstone Reservoir

Accurate characterization of the micro- and nano-pore radius values in a tight sandstone reservoir is the key work to reasonably evaluate reservoir properties. The previous exploration of pore-stitching methods is mainly based on the morphological extension of similar segments. However, few scholars compare and verify the image and non-image stitching methods, so they cannot clarify the application scope of different pore-stitching methods. In this study, the pore structures of eight selected tight sandstone samples were evaluated using high-pressure mercury injection, nuclear magnetic resonance, scanning electron microscope, and the helium porosity test. Then, the C-value fitting, interpolation fitting, and morphological fitting were used to establish high-pressure mercury injection and Nuclear Magnetic Resonance (NMR) pore distribution curves to evaluate the differences among the micro-nano-scale pore radius values determined by the three fitting methods. Finally, the pore radius distribution is extracted from the binary image of Scanning Electron Microscope (SEM). After correcting the helium porosity data, the application scope of different fitting methods is evaluated by using the mean standard deviation verification method, and the optimal solution of the stitching method of pore radius distribution in each application scope is found. Compared to other studies, this research demonstrated three relatively simple methods for the determination of the full range of pore size distributions, providing a reliable method to evaluate the prerequisites of the range of application. This study provides a new idea for the micro-nano-scale pore radius splicing method of a tight sandstone reservoir, and the research results can provide a reference for the actual reservoir evaluation of oil and gas fields.

Integrated Flow Emulsion Electrosynthetic System by In Situ Generation of Emulsions, Subsequent Emulsion Electrolysis, and Final Phase Separation

In this work, we developed a continuous flow emulsion electrosynthetic system. This new flow system involves 20 kHz ultrasonication for acoustic emulsification of water-insoluble organic amines in an aqueous electrolyte without the use of a surfactant, followed by emulsion electrolysis in the flow microreactor and separation of the emulsion into aqueous and oil product (organic nitriles) phases using a liquid–liquid separator. The 20 kHz ultrasonication provided a stable emulsified solution containing organic amine droplets with a relatively narrow size distribution in the micrometer range. The subsequent emulsion electrolysis in the microreactor yielded the desired nitrile product very effectively. In addition, in a continuous flow operation, the emulsion after the electrolysis was efficiently separated into an aqueous electrolyte and oil product using a liquid–liquid separator. The proposed system is robust, and the desired product was successfully synthesized at the gram scale.

An experimental investigation into the soot particle emissions at early injection timings in a single-cylinder research diesel engine

Engine experiments were performed to examine the effect of early-injection on smoke emissions and engine performance under typical low temperature combustion (LTC) and reactivity controlled compression ignition (RCCI) operating conditions. On that basis, the influence of exhaust gas recirculation (EGR), intake pressure, fuel properties and fuel injection strategy on the engine-out soot emissions at early injection timings was also assessed. At last, the morphology, nanostructure characteristics of exhaust soot particles were analyzed. The test results showed when the injection timing was advanced before −30° crank angle after top dead center (CA ATDC) and earlier, the fuel spray impinged onto the piston crown surface, and a part of fuel entered into the squish zone and expanded to reach the cylinder liner wall and entered into the crevice volume, leading to a continuous increase in soot emissions, the peak smoke emission was found to occur at −55° CA ATDC. By adopting fuels with high volatilities and a RCCI fuel delivery strategy, soot emissions can be effectively reduced at early timings. Most of the high-resolution transmission electron microscopy (HRTEM) images of the sampled soot particles showed small spherical particles with a wide range of size distribution connected, and “onion-like” fringe arrangement was found in most of the images. As the fuel injection timing was retarded from −55° to −35° CA ATDC, the samples exhibited more highly organized carbon nanostructures; the fringe tortuosity and separation distance increased, while the fringe length decreased. The formation of more ordered arrangement of graphene layers led to significant resistance to oxidation.

Novel Learnings of Proppant Transport Behavior in Unconventional Hydraulic Fractures

Summary Effective proppant placement has been one of the key objectives of hydraulic fracturing. Different proppant and fracture fluid characteristics and placement methodologies have been historically applied based on learnings from standard proppant transport studies with parallel plate slots. The standard test setup represents a simplified planar fracture with constant width and confined height, incorporating only basic flow characteristics, and thus, is inadequate to capture unique phenomena of proppant transport in unconventional reservoirs. In this study, proppant transport laboratory tests were conducted on a large-scale (10×20 ft) tortuous slot flow system. This novel setup incorporates many significant unconventional fracture features, including lateral and vertical tortuosity, variable width, leakoff, fluid dynamics replicating upward fracture growth, and so on. Proppant transport behavior was investigated with multiple parameters such as proppant size, density, and concentration; fracture fluid type and viscosity; pumping sequence; pump rate; and fracture properties (width, leakoff location and rate, fracture tortuosity profile, and flow directions). The detailed parametric and integrated study of test results includes analysis of proppant dune evolution, dune shape, particle-size distribution across dune, propped area, fluid, and proppant collected from leakoff and exit ports. Multiple unique phenomena occurring at tortuous interfaces were observed, including the generation of isolated pockets of proppant pack, restriction of upward movement owing to proppant bridging, and creation of discontinuous and sparsely distributed proppant pillars above the dune. The test results demonstrated a larger proppant dune angle in front of the dune peak during injection and a subsequent falloff of proppant pack with a higher percentage of smaller mesh proppant backfilling the area at and near the inlet (analogous to the wellbore). Self-segregation of proppant in slickwater as per mesh size resulted in higher percentage of smaller mesh (larger size) proppant settled near the injection point, and a higher percentage of larger mesh (smaller size) proppant placed farther in the system. These observations and novel learnings highlight that it is critical to account for tortuous fracture pathway, leakoff effects, and flow directions (both lateral and upward) to better understand proppant transport behaviors in unconventional fractures. A partially proppant-filled fracture area is recognized in unconventional fracture in addition to general classification of propped and unpropped fracture area. Using proppant with large mesh size distribution range or pumping smaller mesh proppant first in slickwater helps achieve dual benefits of higher near-wellbore conductivity and improved far-field transport. This study demonstrates and physically verifies unique proppant transport behaviors in unconventional hydraulic fractures. It also provides novel learnings that will help the industry to optimize hydraulic fracture design through the selection of optimum proppant and fluid properties with enhanced pumping strategies for overall well productivity improvement in an unconventional reservoir.