Laser Diffraction Research Articles

Nanogel particles formed from ethanol-treated whey proteins: Effect of heating, pH and NaCl on their stability.

Whey protein particles have gained significant attention for their ability to enhance the functional properties of foods as they can be used for emulsions and foams stabilization or fat substitution. This study explores the ability of whey protein nanogel particles formed in the presence of ethanol (30–70 % w/w) by controlling pH and ionic strength, to retain their morphological properties after ethanol removal. The stability of the produced nanogel particles after the removal of ethanol was investigated under various conditions, including heat treatment (90 °C, 20 min), pH modification (4−7), and the addition of NaCl (50–300 mM). Morphological analysis was conducted using confocal laser scanning microscopy, laser diffraction analysis, and scanning electron microscopy. The results showed that the exclusion of ethanol resulted in the formation of spherical-like nanogel particles with different sizes ranging from 100 to 200 nm in diameter. The pH of the solution affected the stability of the ethanol-free particles, leading to aggregation when the net charge of the protein approached zero. However, no aggregation phenomena were observed away from the isoelectric point. High concentrations of NaCl led to extensive aggregation, but no substantial changes were found upon heating. The production of nanogel particles is a promising advance with potential for a wide range of food applications.

A multi-nozzle nebuliser does not improve tissue drug delivery during PIPAC

BackgroundMulti-nozzle nebulisers for pressurised intraperitoneal aerosol chemotherapy (PIPAC) are implemented in clinical practice to improve the homogeneity of tissue drug delivery. Nonetheless, the advantages of such devices over one-nozzle nebulisers have not been demonstrated thus far. In this study, we compared the performance of multi- and one-nozzle nebulisers by conducting physical and ex vivo pharmacological experiments.MethodsThe one-nozzle nebuliser Capnopen® and the multi-nozzle nebuliser were the subjects of this study. In physical experiments, the aerosol droplet size was measured by laser diffraction spectroscopy. Spatial spray patterns were depicted on blotting paper. Pharmacological experiments were performed on the enhanced inverted bovine urinary bladder model, demonstrating real-time tissue drug delivery, aerosol sedimentation and homogeneity of doxorubicin and cisplatin tissue distribution.ResultsThe multi-nozzle nebuliser had a sixfold greater aerosolisation flow and a threefold greater angle of aerosolisation than Capnopen®. The aerosol particle size and distribution range were higher than that of Capnopen®. Spray patterns on blotting paper were more extensive with the multi-nozzle nebuliser. Real-time tissue drug delivery with the multi-nozzle nebuliser was over 100 ml within 1 min, and the aerosol sedimentation was 48.9% ± 21.2%, which was not significantly different from that of Capnopen®. The doxorubicin and cisplatin tissue concentrations were greater with Capnopen®. Although there was no significant difference in the homogeneity of doxorubicin distribution between the two devices, the homogeneity of cisplatin distribution was significantly higher with Capnopen®.ConclusionThe multi-nozzle PIPAC nebuliser did not fulfil expectations. Even though the surface spray patterns were broader with the multi-nozzle nebuliser, the tissue drug homogeneity and concentration were greater with Capnopen®.Graphical

Establishing a standard protocol for soil texture analysis using the laser diffraction technique

Establishing a standard protocol for soil texture analysis using the laser diffraction technique

Development of novel high entropy alloy feedstocks for powder bed fusion using equimolar CoFeNiCuMn composition

In this study, six different prediction models were used to generate a script to obtain the High Entropy Alloy (HEA) database from which CoFeNiCuMn was selected. The powder form of the alloy was utilized by high-pressure gas atomization. The samples were characterized by Energy Dispersive Spectroscopy (EDS) for chemical analysis, Electron Back-Scattered Diffraction (EBSD) for grain size determination, X-ray Diffraction (XRD), and Transmission Electron Microscopy (TEM) for phase analysis, and nanoindentation for mechanical properties. Equimolar CoFeNiCuMn samples had single face-centered cubic (FCC) structure, and the +106 μm showed 111 GPa elastic modulus and 2.97 GPa hardness. Also, each sample was evaluated for compatibility with powder bed fusion (PBF) by employing Scanning Electron Microscopy (SEM) for morphology, laser diffraction for particle size distribution, and static and dynamic flow analyses for the flowability examination. Considering all results, it was observed that three tests were sufficient to comparatively assess the novel alloy powders as suitable feedstock for PBF. The −15 µm sample exhibited widespread satellite particles in its morphology, resulting in the lowest apparent density of 4.28 g/cm³ and the highest specific energy of 2.60 mJ/g. In contrast, the other samples, with larger particle sizes, demonstrated discrete powder particles and improved flowability parameters.

Response of soil particles around bedrock outcrops to sorting of rock surface flow derived outcrops in a rocky desertification area

Soils around bedrock outcrops, even if they are protected by vegetation to some extent after ecological restoration, are prone to being washed away by rock surface flow (RSF) derived from these outcrops in rocky desertification land. However, the extent of the scouring scale and sorting effect of RSF on the soils around outcrops remains unknown. To solve this problem, a series of soils around bedrock outcrops exposed in sloping farmland (SF, without RSF), abandoned land (AL, 1 year of RSF) and shrub–grassland (SG, 5 years of RSF) were examined by the laser diffraction method in a natural ecological restoration area of rocky desertification, where the duration of the RSF is also the time for ecological restoration. It was found that the RSF had a limited effect on the particle size distribution of the soils, only having a significant scouring effect on the soils at the rock–soil interface within a horizontal distance of 2 cm from the outcrops and an insignificant effect on the soils far away from the outcrops in terms of horizontal distance (10 cm and 20 cm). The particle size distributions of the soil around the outcrops were related to erosion caused by the RSF, but mainly benefited from ecological restoration. Compared with SF, the fine particle content in the soils around the outcrops significantly decreased in AL, but significantly increased in SG. Within a short period (1 year) after natural recovery, the RSF had a reduced effect on the fine particles of the soil around the outcrops; however, this did not occur after a long period (5 years). The results of this study further explain the influence of the RSF on soil erosion and leakage loss in karst areas.

Effect of liquid properties on film behavior on the surface of an airfoil in a high-speed flow and subsequent atomization from the trailing edge

This study examines the behavior of ethanol or water films on the surface of a NACA 0012 airfoil placed in a high-speed air flow. New water film results complement previous measurements of time averaged ligament lengths and droplet sizes generated with the same airfoil. In addition, new data are obtained for ethanol. Air velocities up to 175 m/s are used with liquid flow rates between 1.4 cm2/s and 2.6 cm2/s. The liquid was introduced onto one side of the airfoil via 26 holes, each measuring 0.5 mm in diameter and spaced 1 mm apart. These holes are positioned 35 mm downstream from the leading edge and 65 mm upstream from the trailing edge. Film behavior on the vane is captured with front-lit high-speed video. The accumulation of liquid and breakup of ligaments are captured with backlit highspeed video. Phase Doppler interferometry is used to measure droplet size and simultaneous axial and pitch wise velocity 70 mm downstream of the trailing edge. Finally, laser diffraction is used to measure line averaged droplet sizes. The results indicate notable differences between ethanol and water films. The ethanol film spreads more extensively across the width of airfoil which is attributed due to its lower surface tension. The maximum ligament length for both liquids decrease with higher air velocity and increase with the liquid flow rate. A correlation for maximum ligament length is developed and captures the effect of liquid properties, flow rate, and air velocity. Furthermore, the variation in liquid volume flow rate did not impact droplet size. However, for a given air velocity, the Sauter Mean Diameter is found to depend on surface tension. On the dependency of droplet size on the Weber number, ethanol produced smaller droplet sizes at low values of Weber number. However, at relatively high Weber numbers, the droplet sizes for both water and ethanol were similar. This suggests that droplet size is influenced by factors besides surface tension at low Weber numbers but not at higher Weber numbers. In addition, the Nukiyama-Tanasawa model to fit the volume distribution curves is simplified by fixing p and q terms. Simplification makes the model easier to understand and implement.

Unification of particle size analysis results, part 1 − comparison of particle size distribution functions obtained by various measurement methods

This article concerns comparing the grain size distribution functions of mineral powder samples and analyzes errors obtained by various measurement methods. The research used three standard and currently most frequently used methods: sieve analysis, laser diffraction analysis and vision analysis. The most important research, from the point of view of unification of results, consisted in performing precise analyses of the grain size of mineral powders (fly ash, gneiss, quartz sand and Cu ore) in various grain classes. The measurement techniques used in the research and issues related to measurement analytics were characterized. The distribution functions of the grain size distributions of the tested material samples were obtained by different measurement methods and the measurement errors were compared. Using the coefficient of variation CV calculated for characteristic particle diameters, the accuracy of measurements made using various methods was analyzed. It has been shown that different particle size measurement techniques give significantly different particle size distributions for the same material, with the grain size distribution of the measured samples having a greater impact on the results than the material itself. The lowest values of the coefficients of variation were obtained for wet sieve analysis and the highest for laser diffraction. Reliable data informing about grain size distributions were generated for further model calculations necessary to standardize the results between measurement methods.

A novel approach to the quantitative analysis of the particulate matter in conventional cigarette smoke and heated tobacco product aerosols

The particulate and soluble matter present in aerosols from combustible cigarettes (CCs) and Heated Tobacco Products (HTPs) was collected in liquid water. These liquids, yellowish in the experiments with cigarettes and colourless after using HTPs, were analysed by Laser Diffraction (LD) and by Transmission Electron Microscopy coupled to Energy Dispersive X-ray spectroscopy (TEM-EDX) to study the amount, size, composition, and other features of the particulate matter (PM) present in the collected aerosols.The particulate matter concentration in HTPs samples is below the limit of quantification for LD, and only samples from cigarettes show a particulate matter concentration above such limit. TEM analysis has revealed that the liquid samples (from both, cigarettes and HTPs experiments) contain particulate matter, mainly composed of carbon (C) and oxygen (O), but also of traces of inorganic elements. The TEM electron beam results in the evaporation of the particulate matter derived from HTPs, but not of that derived from cigarettes, highlighting the different nature of the particulate matter in both systems, i.e. liquid particulate matter present in the HTPs aerosols and solid particulate matter in the cigarettes smoke. A protocol for the quantitative comparison of the particulate matter present in aerosols has been applied over sixteen TEM images for each sample, confirming important differences from the point of view of the amount of particulate matter and particle size ranges. Thus, the amount of particulate matter for HTPs aerosol samples is more than one order of magnitude lower than for cigarettes smoke.

Influence of Polyethylene Glycol and Methanol Additions on the Mechanical Alloying Behavior of Cu-4B4C Composite Powder

This study investigated the effect of different process control agent (PCA) usage on mechanical alloying behavior of boron carbide (B4C) reinforced copper (Cu) based composite powder. For this purpose, elemental Cu and B4C powders were weighed and powder specimens were prepared with respect to appropriate mass ratios (96% Cu and 4% B4C). Two different PCA additives, namely polyethylene glycol (PEG) and methanol, were also used to prepare powder samples. The amount of PCA was kept constant at 5wt.% for both specimen. These prepared powder samples were then milled using a planetary type ball-mill. After specified milling periods, milling runs were interrupted and powder samples were extracted from the milling vials for further powder characterization including powder morphology using scanning electron microscopy (SEM) and average particle size (APS) via laser diffraction analysis (Mastersizer). Accordingly, after the completion of milling runs, namely 15 hours of ball-milling, methanol addition was found much more effective at reducing particle sizes than PEG. Final APS values for powder specimens having PEG and methanol as PCAs were determined to be 8.237 and 4.101 microns, respectively.

Variations in soil erodibility (K-factor) for the Chernozems depending on the method of texture determination

Soil erodibility (K-factor) is an important parameter in erosion modeling, is one of five factors of the Revised Universal Soil Loss Equation (RUSLE), and generally represents the soil's response to rainfall and run-off erosivity. The erodibility could be determined based on direct measurements of soil properties and mathematical calculations. In this study, the K-factor was calculated based on a formula from RUSLE, proposed by Renard et al. (1997). All input parameters: soil organic carbon (SOC), soil structure, and permeability classes were measured by one method, but particle size distribution – in two ways by sedimentation and laser diffraction methods to assess the impact the K-factor variability and the values of soil erosion rates. The 107 soil samples of Chernozems from Kursk Oblast (Russia) were studied. The texture for the most of samples was classified as silty loam in both analyses. However, the laser diffraction underestimates the clay content by an average of 13.2% compared to the pipette method. The average K-factor estimated based on laser diffraction data was 0.050, and 0.034 t ha h ha−1 MJ−1 mm−1 – sedimentation method. Thus, depending on the method of soil texture analysis, the RUSLE calculated soil loss could underestimated/overstated by 32% (or 4 t ha-1 yr-1 on average in the study site). Therefore, we propose a regression equation-based conversion method of laser diffraction data to sedimentation method data for Chernozems.The Laska-TM laser analyzer measured on ∼ 13% less clay fraction (more on ∼ 8% silt and ∼ 5% fine sand) compared with sedimentation method data.For erosional researchers/modelers it is suggested to state the method of soil texture analysis (based on sedimentation law or laser diffraction) was used for RUSLE K-factor calculations.To convert K-factor values (for Chernozems) calculated and based on data of the sedimentation method to laser sedimentation – it suggested utilize the coefficient 1.47 (0.68 – vice versa).

Comparison between Liquid Immersion, Laser Diffraction, PDPA, and Shadowgraphy in Assessing Droplet Size from Agricultural Nozzles

Spray droplet diameters play a key role in the field of liquid plant protection product (PPP) application technology. However, the availability of various measurement techniques, each with its unique operating principles for evaluating droplet size spectra, can lead to different interpretations of spray characteristics. Therefore, in this study, four measurement techniques—Liquid Immersion (LI), Laser Diffraction (LD), Phase Doppler Particle Analysis (PDPA), and Shadowgraphy (SG)—were utilized to evaluate the droplet size distribution of agricultural spray nozzles. Additionally, PDPA and SG were used to assess the average velocity of spray droplets. Experiments were conducted in three different laboratories with the main aim of comparing results obtained with various types of equipment utilized under ordinary practical conditions. Spraying tests were carried out using three flat fan nozzles and an air-induction flat fan nozzle. As a general trend, the lowest values for droplet diameters were measured using the Laser Diffraction technique, followed by Shadowgraphy. The PDPA technique provided the highest values for mean diameters (D10, D20, and D30) and the numeric median diameter (Dn0.5), whereas the Liquid Immersion method yielded the highest values for the Sauter mean diameter (D32) and volumetric diameters (Dv0.1, Dv0.5, and Dv0.9). Importantly, all measurement techniques were able to discriminate the four nozzles based on their Dv0.5 diameter. Average droplet velocities showed a similar pattern across the four nozzles with the PDPA and the SG measurement techniques. The differences in diameter values observed with the four measurement techniques underline the necessity of always including reference nozzles in spray quality assessments to base classifications on relative rather than absolute values.

Pectin-based hydrogel loaded with polymeric nanocapsules for the cutaneous delivery of tacrolimus: A targeted approach for the treatment of psoriasis

This study aimed to develop a novel pectin-based hydrogel (PEC) incorporating nanocapsules-loaded tacrolimus (NCtac), named PEC-NCtac, as a potential strategy for psoriasis treatment. Blank nanocapsules (NC), PEC, PEC-NC, non-encapsulated tacrolimus (TAC), and the commercial TAC ointment (Tacroz®) were used as controls. The objectives involved physicochemical characterizing PEC-NCtac, assessing its cytotoxicity and anti-inflammatory effects, comparing adhesiveness with controls, determining skin penetration and permeation, and evaluating irritation potential. PEC-NCtac had an unimodal size distribution by laser diffraction (mean diameter of 250 nm and polydispersity -SPAN- of 1.68), drug content of 0.81 mg g−1 (HPLC), and pH of 4.51 (potentiometry). The nanoformulation had no significant impact on the viability of HaCat cells and CD4+ T cells when tested 24 h after treatment, with both cell types maintaining nearly 100 % viability. Treatment with NCtac resulted in a reduction in the pro-inflammatory cytokine IL-17A (p < 0.05). Adhesion studies revealed that PEC-NC showed a 1.9-fold higher force work compared to PEC. The combined effect of individual adhesion of NC and PEC when associated (PEC-NC) was evident in both healthy and injured skin (Healthy skin = 73 mN mm; Injured skin = 251 mN mm). PEC-NCtac allowed a decrease in skin drug permeation in the epidermis of injured skin compared to Tacroz® (40 % vs. 70 %, respectively). PEC-NCtac exhibited non-irritating activity in the HET-CAM/CAM-TBS model, while TAC demonstrated slight irritant activity. Furthermore, PEC-NCtac showed superior anti-inflammatory effects compared to TAC (75.0 % vs. 58 %, P value = 0.03). Summarizing, PEC-NCtac appears promising for topical treatment, demonstrating enhanced adhesion, skin penetration, safety profile, and anti-inflammatory activity.

Synthesis of chromium carbide powder by vacuum-free electric arc plasma method

Chromium carbide powders were synthesized by vacuum-free electric arc method using pure chromium and carbon powder as starting components. The powders obtained in the experimental series were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), laser diffraction and differential thermal analysis. In the experiments, electrical parameters were recorded, and the thermal field generated in the reaction zone was measured using an infrared camera and tungsten‑rhenium thermocouples. The study results show the feasibility of plasma arc discharge synthesis of chromium carbide compounds Cr3C2 and Cr7C3 within 60 s at current intensity of 200 A. SEM analysis of the resulting powder shows that it consists of acute-angled particles of ∼9 to ∼50 μm in size. An updated design of the discharge circuit employed in the study significantly increases the purity of the final product. Vacuum-free electric arc synthesis of chromium carbide has been studied for the first time.

Closer Approach towards the Preparation of Cellulose and Microcrystalline Cellulose from Corn Husks

AbstractIn this work, cellulose was effectively produced from corn husks by a simple and eco‐friendly method. Major influencing variables for cellulose extraction were examined, and the highest yield of lignin and hemicellulose cleavage was achieved after corn husks were treated in 12.5 wt % NaOH solution at solid/liquid ratio (S/L) of 1:10 g mL−1, 70 °C for 90 min. Subsequent bleaching conducted in 10 wt % H2O2 solution at 80 °C for 90 min produced cellulose with a lightness value (L*) of ∼87, chromaticity indexes a* = −1.85, b* = 2.94 with high purity, 90.86 %, and crystallinity, 64.94 %. Fourier transform infrared, scanning electron microscopy, and x‐ray diffraction analysis showed a clear transition in morphology, structure modification, and crystallinity consistent with the alteration of the chemical composition from raw material to delignified residue and the bleached one. To synthesize microcrystalline cellulose (MCC), the hydrolysis was investigated in H2SO4 solutions of different concentrations and durations via monitoring particle size distribution by laser diffraction spectroscopy. At the most efficient conditions (30 wt % H2SO4, 18 h, 45 °C, 1:10 S/L ratio), the obtained MCC reached an average particle size of 42.68 µm, crystallinity degree of 61.6 %, and cellulose purity of 92.5 %. Meanwhile, similar parameters with 4 N HCl solution produced MCC with the same purity but higher crystallinity (65.6 %), higher mean size, 67.62 µm, and higher aspect ratio. SEM images showed that 4 N HCl caused less detrimental and erosive action, and less fragmentation on cellulose microfibrils compared to 30 wt % H2SO4. The study's outcome supports the feasibility of corn husks to produce cellulose and MCC for further applications.

Automated Continuous Crystallization Platform with Real-Time Particle Size Analysis via Laser Diffraction.

The fourth industrial revolution is gaining momentum in the pharmaceutical industry. However, particulate processes and suspension handling remain big challenges for automation and the implementation of real-time particle size analysis. Moreover, the development of antisolvent crystallization processes is often limited by the associated time-intensive experimental screenings. This work demonstrates a fully automated modular crystallization platform that overcomes these bottlenecks. The system combines automated crystallization, sample preparation, and immediate crystal size analysis via online laser diffraction (LD) and provides a technology for rapidly screening crystallization process parameters and crystallizer design spaces with minimal experimental effort. During the LD measurements, to avoid multiple scattering events, crystal suspension samples are diluted automatically. Multiple software tools, i.e., LabVIEW, Python, and PharmaMV, and logic algorithms are integrated in the platform to facilitate automated control of all the sensors and equipment, enabling fully automated operation. A customized graphical user interface is provided to operate the crystallization platform automatically and to visualize the measured crystal size and the crystal size distribution of the suspension. Antisolvent crystallization of ibuprofen, with ethanol as solvent and water with Soluplus (an additive) as antisolvent, is used as a case study. The platform is demonstrated for antisolvent crystallization of small ibuprofen crystals in a confined impinging jet crystallizer, performing automated preplanned user-defined experiments with online LD analysis.

Chloride Gradient Is Involved in Ammonium Influx in Human Erythrocytes.

The ammonia/ammonium (NH3/NH4+, AM) concentration in human erythrocytes (RBCs) is significantly higher than in plasma. Two main possible mechanisms for AM transport, including simple and facilitated diffusion, are described; however, the driving force for AM transport is not yet fully characterized. Since the erythroid ammonium channel RhAG forms a structural unit with anion exchanger 1 (eAE1) within the ankyrin core complex, we hypothesized the involvement of eAE1 in AM transport. To evaluate the functional interaction between eAE1 and RhAG, we used a unique feature of RBCs to swell and lyse in isotonic NH4+ buffer. The kinetics of cell swelling and lysis were analyzed by flow cytometry and an original laser diffraction method, adapted for accurate volume sensing. The eAE1 role was revealed according to (i) the changes in cell swelling and lysis kinetics, and (ii) changes in intracellular pH, triggered by eAE1 inhibition or the modulation of eAE1 main ligand concentrations (Cl- and HCO3-). Additionally, the AM import kinetics was analyzed enzymatically and colorimetrically. In NH4+ buffer, RBCs concentration-dependently swelled and lysed when [NH4+] exceeded 100 mM. Cell swelling and hemolysis were tightly regulated by chloride concentration. The complete substitution of chloride with glutamate prevented NH4+-induced cell swelling and hemolysis, and the restoration of [Cl-] dose-dependently amplified the rates of RBC swelling and lysis and the percentage of hemolyzed cells. Similarly, eAE1 inhibition impeded cell swelling and completely prevented hemolysis. Accordingly, eAE1 inhibition, or a lack of chloride anions in the buffer, significantly decreased NH4+ import. Our data indicate that the eAE1-mediated chloride gradient is required for AM transport. Taken together, our data reveal a new player in AM transport in RBCs.

Environment found to explain the largest variance in physical and compositional traits in malting barley grain.

Starch is the most abundant constituent (dry weight) in the barley endosperm, followed by protein. Variability of compositional and potentially related physical traits due to genotype and environment can have important implications for the malting and brewing industry. This was the first study to assess the effects of genotype, environment, and their interaction (G × E) on endosperm texture, protein content, and starch traits corresponding to granule size, gelatinization, content, and composition, using a multi-environment variety trial in California, USA. Overall, environment explained the largest variance for all traits (ranging from 23.2% to 76.5%), except the endosperm texture traits wherein the G × E term explained the largest variance (45.0-86.5%). Our unique method to quantify the proportion of fine and coarse milled barley particles using laser diffraction showed a binomial distribution of endosperm texture. The number of small starch granules varied significantly (P-value < 0.05) across genotypes and environments. We observed negative correlations between total protein content and each of enthalpy (-0.70), total starch content (-0.54), and difference between offset and onset gelatinization temperature (-0.52). Furthermore, amylose to amylopectin ratio was positively correlated to volume of small starch granules (0.36). Our findings indicate that environment played a larger role in influencing the majority of starch-related physical and compositional traits. In contrast, variance in endosperm texture was largely explained by G × E. Maltsters would benefit from accounting for environmental contributions in addition to solely genotype when making sourcing decisions, especially with regards to total protein, total starch, enthalpy, and difference between offset and onset gelatinization temperature. © 2024 Society of Chemical Industry.

Comparison of eggshell powder blended cementitious materials with ASTM Type IL cement-based materials

The present study explores the potential of producing an alternative ASTM Type IL portland-limestone cement (PLC) using up to 20 % eggshell powder (ESP) by mass as crushed ESP is similar in chemical composition to limestone. To this aim, the hydration, durability, and mechanical properties of the ESP blended cementitious system (using ASTM Type I/II portland cement) are compared to a commercially available ASTM Type IL cement system containing approximately 10 % limestone. ESP was prepared by milling for 3 h upon drying. Characterization of the ESP was done by x-ray diffraction for phase analysis, scanning electron microscopy for microstructural observation, and laser diffraction analysis for particle size distribution. A range of experimental tests were undertaken on both the ASTM Type I/II cement replaced with ESP and the ASTM Type IL systems. Results revealed that the utilization of up to 20 % ESP enhanced the heat of hydration secondary peak (C3A) by increasing the aluminate phase kinetics in the blended system at a favorable pH pore solution. Also, an accelerating effect on the setting time (increased by 20–100 mins) was observed for ESP samples. Chemical shrinkage, compressive strength, and degree of hydration were similar between the ESP and PLC samples. Results also revealed that ESP particles were relatively more effective in minimizing drying shrinkage by 20–35 %, which is attributed to possible internal curing effects. Overall, 10 % ESP blended with ASTM Type I/II cementitious system was similar to the 10 % limestone containing PLC system and could be used as waste material in producing an alternative ASTM Type IL cement.

THE EFFECT OF COASTAL AND CHANNEL MANGROVES SEDIMENT ON BIOTURBATION DISTRIBUTION

Mangroves are a type of tropical tree that thrives and flourishes in harsh conditions where most vegetation struggles. Despite their resilience, mangrove ecosystems face significant threats from deforestation, pollution, and human activities. As an exceptionally efficient habitat for the capture and stabilization of sediment, the mangrove region is also supported by the bioturbation activity where organisms burrow and play an important role in the carbon and nutrient cycle while shaping soil geomorphology within the ecosystem. Many discoveries on the distribution of bioturbation have been carried out in coastal areas regarding grain size, soil density, and others. However, the difference in bioturbation activities on different physical attributes such as coastal, channels, and creeks areas has not yet been well addressed especially in Malaysia. Thus, this study proposes to elucidate the difference in bioturbation distribution between coastal and channel regions in the mangrove areas. The aim is to determine bioturbation distribution within coastal and channel regions by investigating the sediment characteristics and bioturbation frequencies along these two regions. The stratified random quadrat sampling method has been used for bioturbation frequencies, inhabitant species, and population richness. The sediment was characterized with a standard soil dry-sieving method and further analysed by laser diffraction method for fine particle distribution. In examining the effect of physical attribute influence on the bioturbation distribution, a two-way ANOVA assessment was carried out. This study has found that coastal and channel had different sediment distribution and the bioturbation frequencies were influenced by different inhabitants in both regions. Thus, the result of this study supports that coastal and channel regions have significant differences in the bioturbation process. The outcome of this study perhaps will increase awareness among the community members and their involvement in the enrichment and nurturing of ground areas, especially mangrove forests (SDG14).

Reconciling Coulter Counter and laser diffraction particle size analysis for aquaculture monitoring

The disaggregated inorganic grain size (DIGS) of bottom sediment analyzed with a Coulter Counter (CC) has been used to show that the fraction of sediment deposited in flocs (floc fraction) increased in both the near and far field after the introduction of open cage salmon aquaculture, altering benthic habitat and species composition. As a result, DIGS was identified as a potential indicator of regional environmental changes due to aquaculture. Laser diffraction is an attractive alternative to the CC because of its greater efficiency and larger size range. To determine if a laser diffraction instrument, Beckman-Coulter LS 13 320 (LS), could replace the CC within a Canadian national aquaculture monitoring program, the DIGS of 581 samples from five different regions in eastern Canada were analyzed with an LS and a CC. Results show that the LS could not be used to calculate floc fraction. Instead, % sortable silt and the volume % of inorganic particles < 16 µm were evaluated as alternative proxies for fine sediment properties. LS and CC values for these parameters were correlated, but they were significantly different and the relationship between the instruments was dependent on the area sampled. The LS did not capture variations between areas seen in the CC DIGS data. Where the DIGS from the CC found no sorting in the finest size classes, all the LS samples had similar size distributions characterized by smooth modal peaks. The LS and CC both return values that can be used to monitor changes in the deposition of fine-grained sediment, but the LS cannot determine changes in floc deposition and caution is required if comparing different sedimentary environments.