High Fineness Research Articles

The Over-Prediction of Seismically Induced Soil Liquefaction during the 2016 Kumamoto, Japan Earthquake Sequence

Following the M7.0 strike-slip earthquake near Kumamoto, Japan, in April of 2016, most geotechnical engineering experts believed that there would be significant soil liquefaction and liquefaction-induced infrastructure damage observed in the densely populated city of Kumamoto during the post-event engineering reconnaissance. This belief was driven by several factors including the young geologic environment, alluvially deposited soils, a predominance of loose sandy soils documented in publicly available boring logs throughout the region, and the high intensity ground motions observed from the earthquake. To the surprise of many of the researchers, soil liquefaction occurred both less frequently and less severely than expected. This paper summarizes findings from our field, laboratory, and simplified analytical studies common to engineering practice to assess the lower occurrence of liquefaction. Measured in situ SPT and CPT resistance values were evaluated with current liquefaction triggering procedures. Minimally disturbed samples were subjected to cyclic triaxial testing. Furthermore, an extensive literature review on Kumamoto volcanic soils was performed. Our findings suggest that current liquefaction triggering procedures over-predict liquefaction frequency and effects in alluvially deposited volcanic soils. Volcanic soils were found to possess properties of soil crushability, high fines content, moderate plasticity, and unanticipated organic constituents. Cyclic triaxial tests confirm the high liquefaction resistance of these soils. Moving forward, geotechnical engineers should holistically consider the soil’s mineralogy and geology before relying solely on simplified liquefaction triggering procedures when evaluating volcanic soils for liquefaction.

Adaptive Behavior of Small Business Owners in The Context of The COVID-19 Pandemic

Small business survived hard times during 2020–2022. The COVID-19 pandemic resulted in temporary decrease in consumer demand, revenue losses, and bankruptcies. The number of small companies in Russia has dropped dramatically as well as the number of workers engaged in small enterprises. This research aims to reveal major difficulties and institutional barriers small business owners faced during the COVID-19 pandemic. The focus of the research is on patterns of economic behavior Russian entrepreneurs demonstrated adjusting their business processes to the new economic environment. This work is a qualitative research initiative based on a series of in-depth semi-structured interviews with small business owners from the Rostov region, Russia. Interviewing and the following discourses analysis allowed us to understand the meaning and reasoning of small business owners’ behavior. The theoretical framework of the research includes the concepts of institutional economics and the insights from behavioral economics. This “mixed” approach provided us with more opportunities for describing various patterns of economic behavior in the context of fundamental uncertainty. As the pace of institutional change associated with the spread of the virus was very rapid, there was no time for companies to adapt to the new rules. Business owners often resisted changes. The high level of uncertainty became the reason for expectant behavior among small business owners based on the ‘status-quo’ strategy. Even the announcement of high fines did not stop business owners from violating the laws. Explicit opportunism went hand in hand with formal obedience. Despite this, according to official statistics, Russian small business demonstrated high resistance to various economic and social challenges during the pandemic period.

Small strain stiffness, microstructure and other characteristics of an allophanic volcanic ash

Small strain mechanical properties are a prerequisite for seismic analysis and design. Corresponding studies on volcanic soils are by themselves limited while research on some volcanic ashes which intrinsically have high fines content is even rarer. Presence of clay minerals like allophane and imogolite confers uncharacteristic properties to the soils which somehow seems underappreciated. This is evidenced, for instance, by the near absence of literature related to the 2016 Kumamoto Earthquake explicitly mentioning the influence of these particular clay minerals. Against this background, this study aimed at partially filling the gap with respect to the small strain shear modulus, Gmax of an allophanic volcanic ash and underline the influence of allophane and imogolite on some of the soil properties. Remoulded black volcanic ash, kuroboku was sampled from two sites in the Kyushu area in the south of Japan. As part of the experimental work, a series of index properties, engineering properties, electron microscope (Scanning Electron Microscope (SEM) and Field Emission Scanning Electron Microscope (FE-SEM)) examinations and bender element (BE) tests was performed on these soils. The paper elaborates on the peculiar characteristics of the allophanic volcanic ash, including presence and effect of water of crystallization and influence of electrostatic bonding on grain size distribution and liquefaction resistance. Based on the SEM and FE-SEM images, the microstructure of the kuroboku soils was assessed in terms of its various components, the contact relation and the pore space. Observations from the microscopy analysis like presence of diatoms and intra-elemental pores were key to understanding the slight variation in the Gmax among the tested soils. An attempt was also made at situating the Gmax of the kuroboku soil vis à vis other types of soils. Empirical relationships for estimating the Gmax of kuroboku separately and with other volcanic soils were proposed. Findings from this research could rekindle an interest into further understanding the particular characteristics of allophanic materials as well as encourage more research on their dynamic properties, which is essential considering that these materials are mostly found in seismically active regions.

Health Benefits of High Protein and Dietary Fiber Dry-Fractioned Brewery Spent Grain Fines

Health Benefits of High Protein and Dietary Fiber Dry-Fractioned Brewery Spent Grain Fines

Cleaner energy potential analysis for composite biomass residues from decentralized sawmills in Ghana- A case study for Oforikrom Municipality

The variation of wood species processed in sawmills in developing countries generates composite waste which presents treatment challenges due to a lack of understanding of their physicochemical characteristics for proper planning for clean energy generation. Most of the waste is discarded or burnt openly which releases harmful gases into the environment. This study investigated the physicochemical characteristics of mixed sawdust generated from five wood species generated at a Ghanaian sawmill in Oforikrom Municipality for improving waste treatment. The particle size distribution (PSD), bulk density, proximate and ultimate values, thermogravimetric analysis (TGA) and structural analysis were used to characterize the composite sawdust for briquetting and gasification purposes. It was found that the net heating value (17.46 MJ/kg), some proximate and ultimate values meet briquette standard but high percentages of ash (2.95%), moisture (41.48%) and the possibility of nitrogen oxides emissions were notable challenges. PSD resulted in different high fine fractions which are unsuitable for densification. The increase of sieving amplitudes at 30, 50 and 80 rpm generated an average increase in sieve efficiency of fines by 4.22%. Mixing of fines (42.38–46.6%) and optimum particle size (53.40–57.62%) fractions was suggested as the best approach to enhance briquette density and durability. The FTIR spectra showed a range of peaks such as 1734.46 cm−1, 1620.48 cm−1, 1506.50 cm−1, 1462.02 cm−1, 1420.32 cm−1 etc. for functional groups identification. Composite sawdust spectra showed high absorbance with no shift of wavenumbers compared with temperate woods, however, it deviated massively when compared with industrial cellulose and organosolv lignin. TGA indicated that exact mixed wood pyrolysis temperatures, volatile and biochar fractions will always depend on sample compositions. The increase in heating rates yielded little significance to volatiles and char increments. Collection of clean sawdust and rooftop drying were recommended as a way of enhancing sawdust properties. Composite sawdust has a promising potential to support Ghana's activities for meeting the renewable energy generation targets. The understanding of these potential assessments is significant to boost the local municipality energy supply.

Atomistic investigation of modulating structural heterogeneities to achieve strength-ductility synergy in metallic glasses

Structural heterogeneities, i.e., spatial fluctuations of free volume, are of vital importance to the plasticity of irradiation-rejuvenated metallic glasses (MGs), but the mechanisms on how they affect the irreversible deformation and strength remain poorly understood. To address this issue, with the help of atomistic simulations, we systematically investigate the effect of structural heterogeneities on the mechanical behavior of tailored heterogenous MGs with uniformly distributed rejuvenated phases from several critical aspects such as pattern distribution, volume fraction and size effect. The results revealed that the periodically arranged soft rejuvenated phases with low diagonal orientation, high volume fraction and fine phase size alleviate the propensity of strain localization during the tensile deformation, hence promote the homogenous-like plastic flow mediated by the mass of homogenous shear transformation zones (STZ) operations. More importantly, the strength-ductility synergy of MGs was achieved at the given volume fraction of the rejuvenated phases via properly designing the arrangements of the heterogenous phases. The present study sheds light on the atomistic understanding of the relationship between the structural heterogeneity of rejuvenated amorphous structures and mechanical properties in MGs, which can provide useful insights for designing or processing MGs with a strength-ductility synergy.

Ultrasonic treatment of high phosphorus Australian iron ore fines

The trends and efficacy of ultrasonic pre-treatment before desliming high phosphorus Australian iron ore fines was investigated in the presented fundamental study. The −1 mm iron ore fines (57.5 wt% Fe, 2.47 wt% Si, 2.15 wt% Al, 0.132 wt% P) were subjected to sonication while the ultrasonic power, duration and pumping direction were varied. Sonication increased the iron grade and decreased the Si and Al assay in all size fractions except the ultrafines, where the opposite occurred.Ultrasonic treatment was found to depend on the total sonication energy input (up to 68 kJ) with no preference for either power or duration alone. The direction of pulp circulation was important and best results were obtained by pumping the pulp downwards past the ultrasonic probe rather than upwards.Sonication of iron ore fines suspended in water promotes deagglomeration, surface cleaning or disintegration, resulting in substantial deportment of mass from the coarser size fractions to the ultrafines (less than9.9 µm). The iron grade of ultrafines generated by sonication was lower than that of the ultrafines in the head sample, while the corresponding grades of Si, Al and P were higher. Increasing the sonication energy increased the proportion of hematite and decreased the proportion of kaolinite in material that deported to the ultrafines, which was most probably due to the surface action of ultrasonic treatment. A substantial portion of kaolinite (∼33 %) deported to the ultrafines during sonication using 68 kJ, compared with only 8.8 % of the goethite.Desliming of the unsonicated and sonicated samples was evaluated by calculated size classification. The sonication pre-treatments substantially improved the predicted grades of Fe, Si and Al in the deslimed products compared with unsonicated deslimed sample. For experiment using the highest sonication energy (68 kJ) and calculated desliming of < CS5 fraction, the predicted product iron grade improved by 2.8 wt% (1.6 wt% more than unsonicated) after desliming, while the silicon grade decreased relatively by 36.0 % (22.7 % more than unsonicated), the aluminium grade decreased relatively by 39.5 % (25.1 % more than unsonicated) and the predicted phosphorus content decreased relatively by 3.0 % (1.5 % more than unsonicated).The difference in sonication effect between Al, Si and P was due to the association with different minerals. Aluminium and silicon were mainly associated with kaolinite and soft goethite, which were easily disintegrated by ultrasound and deported to the ultrafines, while phosphorus was mainly associated with goethite (mostly of the hard types) present at around 40–48 wt% in most size fractions before and after sonication.

Use of the Heterocypris incongruens bioassay for assessing ecotoxicity of soils containing the anionic surfactant sodium lauryl ether sulphate (SLES)

The production and consumption of surfactants are constantly increasing, and huge amounts are found in the environment as contaminants. Surfactants are widely used in domestic and industrial applications, including in tunnel-mechanized excavation of large-scale infrastructures (e.g. highways and railways). In the latter case, the commercial products are foaming agents containing the anionic surfactant sodium lauryl ether sulphate (SLES). Foaming agents are necessary for enhancing Tunnel Boring Machine-Earth Pressure Balance (TBM-EPB) performance. Consequently, there are SLES concentrations in excavated soils of which large quantities can have harmful effects on biota. SLES toxicity in the aquatic environment is well known; on the contrary, knowledge of its effects on soil organisms is quite limited. In order to better understand SLES ecotoxicity in soil, the standardized bioassay (ISO 14371:2012) with the crustacean Heterocypris incongruens, living in the soil–water interface, was used. The lethal concentrations of standard SLES (LC15: 120; LC50: 140 mg/L, respectively) and of three common commercial products used as foaming agents (LC50 varying from 275 to 3810 mg/L) were evaluated. Subsequently, the crustacean acute and sub-chronic effects (mortality and growth inhibition) were assessed in seven different excavated soils conditioned with various commercial products. In addition, SLES concentrations in each soil and in their soil water extract were also determined. Mortality was not recorded in soils conditioned with foaming agents; however, a growth inhibition (c.a. 61.6 %) was found for soils with a high fine fraction and conditioned with high amounts (≥2 L/m3 soil) of foaming agents. H. incongruens proved to be an appropriate bioassay for assessing the possible effects of high SLES concentrations in soil, especially when this surfactant is bound to soil.

Occurrence State and Properties of Gold Minerals from the Gold Deposits on the North China Platform

By studying both the microscopic physical and chemical typomorphic characteristics of gold minerals associated with representative gold deposits on the north-central margin of the North China Platform, this paper seeks to identify macroscopic metallogenic mechanisms of gold deposits. The majority of the gold minerals from the gold deposits are native gold with minor electrum and calaverite. The form and grain size of gold minerals from the representative gold deposits reflect the metallogenic properties of medium-deep and medium-high temperature deposits. The projected gold fineness of the Xiaoyingpan gold mine all falls in the medium-temperature area in the figure and tends to be in the high-temperature area, while that of the Zhangquanzhuang gold mine mostly falls in the middle-temperature area, showing the difference in the metallogenic conditions of the two deposits. Both Xiaoyingpan and Zhangquanzhuang gold deposits show the following rules: poor in Zn, Pb, Sb and Se, but rich in Cu, Fe without Mn, indicating that both deposits are of medium-deep origin. The three representative gold deposits all show high gold fineness characteristics, and the general rules are as follows: Dongping-type gold deposit (934.8-969.7) &gt; Xiaoyingpan-type gold deposit (900.0) &gt; Zhangquanzhuang type gold deposit (824.0), showing that the representative gold deposits were formed at higher temperature and deeper depth, and the gold in the ores inherited the characteristics of high gold fineness originating from the Archean metamorphic rock series, which implying that the metallogenic material originated from the ancient metamorphic rock series; the long metallogenic period and multiple metallogenic stages made gold fully transformed, purified and enriched. There are three main occurrence states of gold minerals in the study area, from primary to secondary, they are respectively inclusion gold, gold minerals between other mineral crystals and those filled in the fractures of other minerals.

Deep dewatering of bauxite residue via the synergy of surfactant, coagulant, and flocculant: Effect of surfactants on dewatering and settling properties

Complex surface properties and high fineness of bauxite residue (BR) make it hard to compact and settle, which reduces the solid content of the BR cake and solid–liquid separation efficiency. The proposed three-step procedure involving surface wettability adjustment, charge neutralization, and flocculation through the synergy of surfactants, lime, and polyacrylamide (PAM) was carried out. Polycarboxylate superplasticizer (PCE) significantly improved BR dewaterability and decreased the water content from 45.85% to 36.71% (2%) compared with the original BR cake. But the solid recovery also reduced from 93.29% to 89.28% (2%), and the BR slurry was still a stable suspension. The synergy of PCE (0.5%), lime, and PAM effectively coagulated and flocculated the BR particles, and improved BR dewaterability. The average BR particle sizes enlarged from about 10 µm to 22 µm, and the solid recovery and settling rate elevated to 99.35% and 1.596 m/h. The water content of the BR cake reduced from 52.33% to 47.18% compared without PCE addition. The surface behavior and adsorption behavior analysis showed that PCE neutralized the surface charge and decreased the surface tension of BR particles with the adsorption of PCE on its surface. The study gave a feasible suggestion for the efficient dewatering and fast settling of BR.

Research on high quality development strategy of green building: A full life cycle perspective on recycled building materials

China's Green Building (GB) evaluation standard has always emphasized the use of Recycled Building Materials (RBM). However, the quality of RBM is a major obstacle to its promotion. Unlike previous studies, this study innovatively developed a four-way evolutionary game model including Local Government (LG), RBM suppliers, developers and homebuyers, and examined their strategy changes from the production of building materials to the purchase and use of homes. This paper uses MATLAB 2021b software to simulate and verify the model and uses the real market data of Wuhan city and Sanya city to analyze the influence of some key factors among 23 factors such as the price of purchasing natural building materials P2 and the basic utility obtained by purchasing a house B. The results showed the following: (1) Among the four evolutionary stable strategies in this system, the optimal strategy combination lies when LG does not plan, manufacturers perform upcycling and when developers and homebuyers choose RBM. (2) High fines can force suppliers to perform upcycling, and developers will build houses according to homebuyers' preferences. If homebuyers are in immediate demand for homes, they will more willing to purchase homes built with RBM. (3) Considering the financial pressure of LG, it should promote the system in parallel with rewards and penalties in the early stage of development, while after a period of time, LG can stop making any subsidies and only retain the regulation of suppliers. This study helps to better understand the behaviors of various stakeholders in the full life cycle of RBM, and provides some reference for the development of RBM and GB in China.

Mechanical and Pore Properties of Concrete Using Basalt-Based Recycled Aggregates According to Mixture Conditions

This study investigated recycled aggregates of Jeju Island—where porous basalt exists as a natural aggregate—and is a study aimed at verifying the applicability of the basalt-based recycled aggregate in the field. To this end, the application properties of concrete were analyzed using the quality improvement of the recycled aggregate (PRA), the type of fine aggregate received in the region, and the cement content as variables. In an experiment using concrete in which 50% of the PRA was replaced with basalt (BA), the air content of the fresh concrete decreased due to the increasing solid content of the aggregate when PRA and fine aggregates (with an even particle size distribution) were used. Regarding the properties of the hardened concrete, when the PRA and fine aggregate (with a high fineness modulus) were used, the compressive strength was 33.6 MPa and the modulus of elasticity was 23.1 GPa, which are higher than those of the BA specimen. The resistance to carbonation increased due to the improved quality of the PRA specimen. Pores that are 0.3 mm in size or larger decreased when the PRA and fine aggregates of even particle sizes were used. This form of pore reduction was found to have a direct correlation with the improvement of mechanical properties.

Eliminating the influence of measuring point failure in ice load identification of polar ship structures

Ice loads are extreme environmental loads for polar ships sailing in ice regions. Field measurement of polar ship structures is the most direct approach for obtaining ice loads. This study investigates the influence of measuring point failure in ice load identification of polar ship structures and consequently proposes effective practices to eliminate this influence considerably. Based on the simulated strain of a typical polar ship's side grillage, the influence is studied in detail, and the spatial distribution characteristics of the identification error in the monitoring area are subsequently determined. According to the systematic analysis of the strain data at measuring points along frames, the spatial distribution characteristics of the strains are determined and further verified considering typical load scenarios. Consequently, the least squares fitting (LSF) method for the estimation of the strains at failed points is proposed. Practical schemes for ice load identification using the influence coefficient matrix (ICM) method under the influence of measuring point failure are presented and discussed as well. It is found that the LSF method decreases the identification error in the loading area, thereby significantly eliminating the influence. Thus, the scheme associating subarea combination with strain fitting results in higher fineness and better accuracy of ice load identification, which is recommended for adoption and has broad application prospects in the future.

Gold in biogenic apatites of the Baltic-Ladoga phosphorite basin

The distribution of gold in biogenic apatites from the Ordovician deposits in the northwest of the East European Platform shows that the maximum concentration of gold in apatites is found within the Ladoga-Baltic suture zone. Gold mineralization has a superimposed character, which is confirmed by the dependence of the gold content on the size of apatite particles and a number of isotope geochemical systematics in biogenic apatites. Gold is present in the form of high fineness particles to 20 µm in size on the surface of biogenic apatite fragments (phosphate brachiopod shells and conodont elements) and is easily extracted. In 10 % of samples of biogenic apatites, the total content of rare earth elements is more than 1 wt.%.

Novel laboratory methodology for fines migration testing for SAGD wells

The sand retention and the retained permeability or flow performance of sand control screens in unconsolidated formations are usually evaluated through the pre-packed sand retention testing (SRT) procedures. These procedures attempt to address a complex process of fines migration which influences the flow performance of screens in formations with relatively high fines content. Plugging of sand control screens and flow impairment of SAGD wells in unconsolidated Alberta's oil sands is a common problem in which the role of fines migration is prominent. Previous SRT studies for the SAGD wells did not purposefully explore the fines migration process. In this study, a set of pre-packed SRT experiments with comprehensive long-term testing procedures were conducted to simulate the fines migration process and assess the flow performance behavior of a sand screen under SAGD well conditions.The experiment results indicate a non-monotonic behavior of permeability with an initial decrease followed by an increasing trend for the near screen interval of the sand pack. It is observed that the effect of releasing fine particles from or near the pore throats on permeability is dominant compared with the retention of fine particles over the thin pore throats at the first stages of the experiments. Because of testing limitations concerning initial attachment of fine particles at pore surfaces, pore size distribution, and the amount of mobile fine particles as a function of time, most results were inconsistent with decreasing trend behavior of permeability in the field and actual core flooding observations. However, a decreasing behavior was observed by conducting a new test procedure replicating a representative worst-case flow condition in the field. As the main conclusion, the previous SRT test procedures and the design criterion should be revised to enhance the flow performance assessment of sand control screens for formations susceptible to the fines migration process.

Development of excipients free inhalable co-spray-dried tobramycin and diclofenac formulations for cystic fibrosis using two and three fluid nozzles

This study aims to investigate the effect of physicochemical properties and aerosol performance of two (2FN) and three-fluid nozzles (3FN) on the inhalable co-formulation of tobramycin and diclofenac dry powders. Combination formulations of tobramycin and diclofenac at 2:1 and 4:1 w/w ratios were prepared at a laboratory scale using a spray dryer in conjunction with a 2FN or 3FN. Powder size, morphology, solid-state characteristics, and aerodynamic and dissolution properties were characterised. The nozzle types and the formulation composition influenced the yield, particle size, solid-state properties, aerosolization behaviour and dissolution of the co-spray dried formulations. In particular, using the 2FN the co-spray dried formulation of tobramycin and diclofenac at 2:1 w/w showed smaller particle size (D50, 3.01 ± 0.06 μm), high fine particle fractions (FPF) (61.1 ± 3.6% for tobramycin and 65.92 ± 3 for diclofenac) and faster dissolution with approx. 70% diclofenac released within 3 h and approx. 90% tobramycin was released within 45 min. However, the 3FN for the co-spray dried formulation of tobramycin and diclofenac at a 2:1 w/w ratio showed a larger particle size (D50, 3.42 ± 0.02 μm), lower FPF (40.6 ± 3.4% for tobramycin and 36.9 ± 0.84 for diclofenac) and comparative slower dissolution with approx. 60% diclofenac was released within 3 h and 80% tobramycin was released within 45 min. A similar trend was observed when the tobramycin to diclofenac ratio was increased to 4:1 w/w. Overall results suggest that spray drying with 2FN showed a superior and viable approach to producing excipients-free inhalable co-spray dried formulations of tobramycin and diclofenac. However, the formulation produced using the 3FN showed higher enrichment of hydrophobic diclofenac and an ability to control the tobramycin drug release in vitro.

Mechanism of carbonating recycled concrete fines in aqueous environment: The particle size effect

Processing waste concrete in recycling facilities inevitably generates by-products such as very fine particles (<2.36 mm) and powders (<0.15 mm). The resourcing of these low-value recycled concrete fines (RCFs) has attracted increasing interest from the construction industry. This study attempts to elucidate the underlying mechanisms of particle size effects on carbonating RCFs via aqueous route. The results suggested that the relatively coarse particles (0.6–1.18 mm and 1.18–2.36 mm) experienced two positive effects i.e., i) improvement of surface properties by the formation of a reactive shell, and ii) significant densification of the microstructure. This was due to an initial carbonation mediated in the bulk solution, and then the internal carbonation due to the inward diffusion of carbonate species. Meanwhile, the finer particles (<0.15 mm) showed significantly different effects i.e., being totally disintegrated and converted to a calcium carbonate and silica gel composite. Such a difference was attributed to the long alkalinity maintaining ability and extensive dissolution and leaching associated with the high fineness. Whereas 0.15–0.6 mm was regarded as a transition particle size where balanced decomposition and densification were observed. Finally, after carbonating for only 6 h, the carbonated RCFs was found to enhance the compressive strength of pastes (as cement substitute) and mortars (as fine aggregate substitute) by an average of 13.2% and 9.0% in comparison with those prepared with raw RCFs.

“Unable to Defend Him”: Conflicting Views of Female Violence in Swedish Medieval Law

“Unable to Defend Him”: Conflicting Views of Female Violence in Swedish Medieval Law

Dry Powder Inhalers Based on Chitosan-Mannitol Binary Carriers: Effect of the Powder Properties on the Aerosolization Performance.

Carriers play an important role in improving the aerosolization performance of dry powder inhalers (DPIs). Despite that intensive attention had been paid to the establishment of the advanced carriers with controllable physicochemical properties in recent years, the design and optimization of carrier-based DPIs remain an empiricism-based process. DPIs are a powder system of complex multiphase, and thus their physicochemical properties cannot fully explain the powder behavior. A comprehensive exposition of powder properties is demanded to build a bridge between the physicochemical properties of carriers and the aerosolization performance of DPIs. In this study, an FT-4 powder rheometer was employed to explore the powder properties, including dynamic flow energy, aeration, and permeability of the chitosan-mannitol binary carriers (CMBCs). CMBCs were self-designed as an advanced carrier with controllable surface roughness to obtain enhanced aerosolization performance. The specific mechanism of CMBCs to enhance the aerosolization performance of DPIs was elaborated based on the theory of pulmonary delivery processes by introducing powder properties. The results exhibited that CMBCs with appropriate surface roughness had lower special energy, lower aeration energy, and higher permeability. It could be predicted that CMBC-based DPIs had greater tendency to fluidize and disperse in airflow, and the lower adhesion force between particles enabled drugs to be detached from the carrier to achieve higher fine particle fractions. The specific mechanism on how physicochemical properties influenced the aerosolization performance during the pulmonary delivery processes could be figured out with the introduction of powder properties.

The Effect of Fines Content on Compressional Behavior When Using Sand–Kaolinite Mixtures as Embankment Materials

In South Korea, Honam High-Speed Railway has a relatively large residual settlement issue and high fines content has been pointed out as one of the causes. Design guidelines regulate not to use soils containing fines content higher than 25%. However, there is no background information on the effect of fines content on settlement. Therefore, this paper aims to investigate compressional behavior according to fines content using sand and kaolinite. Oedometer test results showed that the compression index is lowest with fines content of 15% to 20% at which the mixture produced maximum density. The optimum fines content for inducing low settlement would be 15% to 20% for the sand–kaolinite mixture. Transition fines content (TFC), which shows sand-like to claylike behavior, was observed to have between 21% and 26% of fines content. Critical fines content (fcrit) where a minimum void ratio occurs was estimated as 21.67%. These behavioral changes appear when fines content is greater than the optimum fines content. SEM also shows that the kaolinite particles were overlapped, creating flat surfaces with a fines content higher than 30%, and showing clay-like behavior. Based on the analysis results, engineers can simply identify the behavior of embankment materials to ensure optimum fines content and consequently minimize long-term settlement potential.