-
Environmental Science and Pollution... May 2023It is of great significance to study the spatial differentiation of surface gravel in northern Tibet Plateau for regional ecological environment restoration. In this...
It is of great significance to study the spatial differentiation of surface gravel in northern Tibet Plateau for regional ecological environment restoration. In this paper, the particle size and spatial position of the surface gravel are studied. On the basis of the impact factors of topography, vegetation, land use, meteorology, soil, social economy, etc., the quantitative attribution of the gravel particle size is studied in the geomorphological type areas of the northern Tibetan Plateau by using geographic detector and regression analysis. The experimental conclusions are as follows: Firstly, the explanatory power of each impact factor to gravel particle size and the coupling degree between factors are different in different geomorphological types. Among the impact factors, NDVI and land use types are the dominant factors that determine the spatial heterogeneity of gravel particle size. However, in extremely high mountain areas, the explanatory power of altitude factor gradually increases with the increase of topographic relief. Secondly, two-factor interaction is helpful to enhance the explanatory power of spatial heterogeneity of gravel particle size. Except for the interaction of altitude factor in the high relief but extremely high-altitude mountains, the interaction of NDVI and other important factors is mostly found in other regions. Among them, the interaction between NDVI and land use type is the most significant. Thirdly, the areas with high gravel particle size identified by the risk detector are mainly areas with high vegetation coverage and weak external erosion, such as shrubbery, wooded land, and high-coverage grassland. Therefore, the specific conditions of different regions should be fully considered in the study of the spatial heterogeneity of gravel size in the northern Tibetan Plateau.
Topics: Tibet; Particle Size; Environment; Soil; Altitude; Ecosystem; China
PubMed: 37017841
DOI: 10.1007/s11356-023-26750-7 -
ACS Nano Jul 2019Living cells achieve precise control of shape and size through sophisticated biochemical machinery. However, such precision is extremely challenging to emulate in... (Review)
Review
Living cells achieve precise control of shape and size through sophisticated biochemical machinery. However, such precision is extremely challenging to emulate in artificial cellular compartments. So far, various physicochemical and mechanical interventions have been employed to tailor the dimensions of model systems such as liposomes, emulsions, coacervates, and polymer capsules. In this Perspective, we discuss the state of the art in artificial cell research in controlling shape and size and the challenges that need to be addressed.
Topics: Artificial Cells; Particle Size; Surface Properties
PubMed: 31298028
DOI: 10.1021/acsnano.9b05112 -
Journal of Environmental Quality Sep 2020Nutrients excreted from animals affect the nutritive value of manure as a soil amendment as well as the composition of gases emitted from manure storage facilities....
Nutrients excreted from animals affect the nutritive value of manure as a soil amendment as well as the composition of gases emitted from manure storage facilities. There is a dearth of information, however, on how diet type in combination with dietary particle size affects nutrients deposited into manure storage facilities and how this affects manure composition and gas emissions. To fill this knowledge gap, an animal feeding trial was performed to evaluate potential interactive effects between feed particle size and diet composition on manure characteristics and manure-derived gaseous emissions. Forty-eight finishing pigs housed in individual metabolism crates that allowed for daily collection of urine and feces were fed diets differing in fiber content and particle size. Urine and feces were collected and stored in 446-L stainless steel containers for 49 d. There were no interactive effects between diet composition and feed particle size on any manure or gas emission parameter measured. In general, diets higher in fiber content increased manure nitrogen (N), carbon (C), and total volatile fatty acid (VFA) concentrations and increased manure VFA emissions but decreased manure ammonia emissions. Decreasing the particle size of the diet lowered manure N, C, VFAs, phenolics, and indole concentrations and decreased manure emissions of total VFAs. Neither diet composition nor particle size affected manure greenhouse gas emissions.
Topics: Animal Feed; Animals; Diet; Gases; Manure; Particle Size; Swine
PubMed: 33016445
DOI: 10.1002/jeq2.20112 -
Waste Management (New York, N.Y.) Feb 2022Fly ash from municipal solid waste incineration (MSWI-FA) contains leachable heavy metals. In the present study the correlations between heavy metal content, particle...
Fly ash from municipal solid waste incineration (MSWI-FA) contains leachable heavy metals. In the present study the correlations between heavy metal content, particle size, speciation distribution with respect to water leaching are investigated, using a combination of solid-state bulk analytical techniques, leaching treatments, sequential extractions and thermodynamic geochemical modelling. Among the analyzed heavy metals, Zn and Pb are the most abundant in any grain size class, followed by Cu, Cr, Cd and Ni, with concentration that tends to increase with a decrease of the grain size. The phase composition is constituted of salt (halite, sylvite, anhydrite and syngenite), which provide the main minerals regardless of the particle size class; calcite, quartz and gehlenite occur in comparatively lower amounts, while 50% wt is composed of amorphous fraction. Heavy metal leaching is strongly correlated to speciation distribution, and in particular to the fraction (F1) associated with salt, carbonate and weak surface sorption. Leaching from speciation due to surface complexation on Al/Fe (hydr)oxide becomes relevant at acidic regime. Particle size and heavy metal content, in turn, moderately correlate with leaching. The F1-speciation as a function of particle size does not exhibit a definite trend shared by all heavy metals under investigation. This suggests that i) differences in speciation distribution, rather than bare heavy metal content or particle size, govern leaching from MSWI-FA; ii) F1 can be regarded as a marker of the potential heavy metal leaching; iii) a comparatively modest efficiency in managing MSWI-FA is expected from grain size separation strategies.
Topics: Carbon; Coal Ash; Incineration; Metals, Heavy; Particle Size; Particulate Matter; Refuse Disposal; Solid Waste
PubMed: 34929536
DOI: 10.1016/j.wasman.2021.12.008 -
The Science of the Total Environment Apr 2022An in-depth understanding of particle size distribution as well as total suspended solids (TSS) in surface runoff is essential for managing urban diffuse pollution. In...
An in-depth understanding of particle size distribution as well as total suspended solids (TSS) in surface runoff is essential for managing urban diffuse pollution. In this study, field experiments and model simulation were undertaken to explore and confirm the dynamic runoff behaviour of TSS and their influencing factors. Field observation results showed that samples with high TSS concentrations contained coarser particles (>100 μm) during three natural rainfall events. Particle size distribution as well as road-deposited sediments (RDS) amount before and after these rainfall events also confirmed that a higher percentage of washed-off coarser particles resulted in higher TSS concentrations in surface runoff water. The impacts of rainfall characteristics, urban-rural gradients, surface roughness, and climate difference on particle distribution as well as TSS concentration were analyzed using the wash-off formula of particle size. These factors mainly affected the contribution rate of RDS to TSS by altering particle size composition; rates ranged from 4% to 44% under different rainfall characteristics. The critical particle size (<100 μm) was developed according to the mass percentage of particles with different sizes in RDS and TSS. Our results can provide a simple and effective way of assessing RDS contribution to TSS in surface runoff.
Topics: Environmental Monitoring; Environmental Pollution; Particle Size; Rain; Water Movements; Water Pollutants, Chemical
PubMed: 35016944
DOI: 10.1016/j.scitotenv.2021.152533 -
Journal of Controlled Release :... Jun 2020Nanocrystals have exhibited great advantage for enhancing the dissolution rate of water insoluble drugs due to the reduced size to nanoscale. However, current...
Nanocrystals have exhibited great advantage for enhancing the dissolution rate of water insoluble drugs due to the reduced size to nanoscale. However, current pharmaceutical approaches for nanocrystals formulation development highly depend on the expert experience and trial-and-error attempts which remain time and resource consuming. In this research, we utilized machine learning techniques to predict the particle size and polydispersity index (PDI) of nanocrystals. Firstly, 910 nanocrystal size data and 341 PDI data by three preparation methods (ball wet milling (BWM) method, high-pressure homogenization (HPH) method and antisolvent precipitation (ASP) method) were collected for the construction of the prediction models. The results demonstrated that light gradient boosting machine (LightGBM) exhibited well performance for the nanocrystals size and PDI prediction with BWM and HPH methods, but relatively poor predictions for ASP method. The possible reasons for the poor prediction refer to low quality of data because of the poor reproducibility and instability of nanocrystals by ASP method, which also confirm that current commercialized products were mainly manufactured by BWM and HPH approaches. Notably, the contribution of the influence factors was ranked by the LightGBM, which demonstrated that milling time, cycle index and concentration of stabilizer are crucial factors for nanocrystals prepared by BWM, HPH and ASP, respectively. Furthermore, the model generalizations and prediction accuracies of LightGBM were confirmed experimentally by the newly prepared nanocrystals. In conclusion, the machine learning techniques can be successfully utilized for the predictions of nanocrystals prepared by BWM and HPH methods. Our research also reveals a new way for nanotechnology manufacture.
Topics: Drug Compounding; Machine Learning; Nanoparticles; Particle Size; Pharmaceutical Preparations; Reproducibility of Results; Solubility
PubMed: 32234511
DOI: 10.1016/j.jconrel.2020.03.043 -
Molecules (Basel, Switzerland) Apr 2022The assessment of active pharmaceutical ingredient (API) particle size and morphology is of great importance for the pharmaceutical industry since it is expected to...
The assessment of active pharmaceutical ingredient (API) particle size and morphology is of great importance for the pharmaceutical industry since it is expected to significantly affect physicochemical properties. However, very few methods are published for the determination of API morphology and particle size of film-coated (FC) tablets. In the current study we provide a methodology for the measurement of API particle size and morphology which could be applied in several final products. Bismuth Oxide 120 mg FC Tabs were used for our method development, which contain bismuth oxide (as tripotassium dicitratobismuthate (bismuth subcitrate)) as the active substance. The sample preparation consists of partial excipient dissolution in different solvents. Following this procedure, the API particles were successfully extracted from the granules. Particle size and morphology identification in Bismuth Oxide 120 mg FC Tabs was conducted using micro-Raman mapping spectroscopy and ImageJ software. The proposed methodology was repeated for the raw API material and against a reference listed drug (RLD) for comparative purposes. The API particle size was found to have decreased compared to the raw API, while the API morphology was also affected from the formulation manufacturing process. Comparison with the RLD product also revealed differences, mainly in the API particle size and secondarily in the crystal morphology.
Topics: Bismuth; Excipients; Particle Size; Tablets
PubMed: 35458800
DOI: 10.3390/molecules27082602 -
IET Nanobiotechnology Feb 2021Nanomicelles are self-assembling nanosized (usually with particle size within a range of 10 to 100 nm) colloidal dispersions with a hydrophobic core and hydrophilic... (Review)
Review
Nanomicelles are self-assembling nanosized (usually with particle size within a range of 10 to 100 nm) colloidal dispersions with a hydrophobic core and hydrophilic shell. Owing to its size, solubility, customised surface or its exposure to the environment, nanomicelles show some unique or novel characteristics, which makes it multifunctional and thus makes its use indispensable in biomedical application and various other fields. This review presents the unique properties of nanomicelles that makes it different from other particles and paves its way to be used as drug delivery agent and many other biological uses or applications. It also emphasises on the drug encapsulation ability of the nanomicelles and different technique of drug loading and delivery along with its advantages and disadvantages.
Topics: Drug Carriers; Drug Delivery Systems; Hydrophobic and Hydrophilic Interactions; Micelles; Nanoparticles; Particle Size; Solubility
PubMed: 34694727
DOI: 10.1049/nbt2.12018 -
Environmental Science & Technology Sep 2023Environmental DNA (eDNA) in aquatic systems is a complex mixture that includes dissolved DNA, intracellular DNA, and particle-adsorbed DNA. Information about the various...
Environmental DNA (eDNA) in aquatic systems is a complex mixture that includes dissolved DNA, intracellular DNA, and particle-adsorbed DNA. Information about the various components of eDNA and their relative proportions could be used to discern target organism abundance and location. However, a limited knowledge of eDNA adsorption dynamics and interactions with other materials hinders these applications. To address this gap, we used recirculating stream mesocosms to investigate the impact of suspended materials (fine particulate organic matter, plankton, clay, and titanium dioxide) on the eDNA concentration and particle size distribution (PSD) from two fish species in flowing water. Our findings revealed that eDNA rapidly adsorbs to other materials in the water column, affecting its concentration and PSD. Nonetheless, only particulate organic matter affected eDNA removal rate after 30 h. Moreover, we observed that the removal of larger eDNA components (≥10 μm) was more strongly influenced by physical processes, whereas the removal of smaller eDNA components was driven by biological degradation. This disparity in removal mechanisms between larger and smaller eDNA components could explain changes in eDNA composition over time and space, which have implications for modeling the spatial distribution and abundance of target species and optimizing eDNA detection in high turbidity systems.
Topics: Animals; DNA, Environmental; Particle Size; Physical Phenomena; Adsorption; Particulate Matter; Water
PubMed: 37610829
DOI: 10.1021/acs.est.3c02638 -
Respiratory Care Oct 2021The purpose of this study was to evaluate how factors (ambient temperature, shaking the inhaler before use, suspension of the inhaler in water, and the variation over...
BACKGROUND
The purpose of this study was to evaluate how factors (ambient temperature, shaking the inhaler before use, suspension of the inhaler in water, and the variation over the lifetime of the inhaler) affect the particle-size distributions from albuterol HFA inhalers.
METHODS
We used a laser particle-size analyzer to measure the percentage of particles in the 1- to 5-μm range (fine-particle fraction) serially 2,500 times per second to obtain a window of useful measurements with each inhaler actuation. We compared the inhaler performance results as follows: cold versus hot, full versus partial versus empty inhaler actuations, shaken versus unshaken, and inhaler characteristics after water submersion.
RESULTS
The effect of temperature was as follows: fine-particle fraction was 14.4% at 5°C, 37.9% at 24 - 25°C, and 38.1% at 45°C. The fine-particle fraction at the start, middle, end, and past the end of the inhaler's rated lifetime were 37.9, 26.3, 27.9, and 22.0%, respectively. Shaking the inhaler did not improve the inhaler's fine-particle fraction. Submerging the inhaler reduced the fine-particle fraction to 14.3% without purging and to 20.5% with purging compared with the 42.1% for the control inhaler, which was not submerged.
CONCLUSIONS
Temperature made a difference, with cold inhalers producing a lower fine-particle fraction. The early portion of the inhaler had a better fine-particle fraction than the middle and end of the inhaler's lifespan. We could not demonstrate that shaking the inhaler had a significant effect on the fine-particle fraction. Submerging the inhaler in water significantly reduced the fine-particle fraction.
Topics: Aerosols; Albuterol; Humans; Metered Dose Inhalers; Nebulizers and Vaporizers; Particle Size
PubMed: 34230213
DOI: 10.4187/respcare.08858