Aggregation Properties Research Articles

Investigation of the antidiabetic and probiotic properties of lactic acid bacteria isolated from some ethnic fermented foods of Darjeeling District

BackgroundIndigenous communities residing in the Darjeeling Himalayan region and its adjacent hilly areas have a deeply rooted cultural tradition of consuming a diverse range of vegetable and milk-based fermented products, believed to confer various health advantages. With this traditional knowledge, lactic acid bacteria (LAB) were isolated from popular fermented foods such as Chhurpi (derived from Bos grunniens milk), Gundruk (made from Brassica juncea leaves), Sinki (derived from Raphanus sativus taproots), and Kinema (produced from Glycine max beans). This study aimed to investigate the probiotic properties of the prevalent LABs, including aggregation properties, bile salt hydrolase activities, survival under gastro-inhibitory conditions, safety evaluations, and their potential health-promoting attributes, with a specific focus on inhibiting α-amylase and α-glucosidase enzymes.ResultsFive of the LAB isolates demonstrated notable viability rates exceeding 85% when exposed to gastro-inhibitory challenges. Based on 16S rRNA gene sequencing, these isolates were identified as Pediococcus pentosaceus (isolate GAD), Lactobacillus plantarum (isolates KAD and CAD), Lactobacillus brevis (isolate SAD), and Lactiplantibacillus plantarum (isolate CMD). These LAB isolates exhibited versatile carbon source utilization, significant auto- and co-aggregation, and bile salt hydrolase (BSH) properties. Auto-aggregation capacity notably increased over time, ranging from 30 to 150 min, with percentage increments from 4.83 ± 1.92% to 67.60 ± 5.93%. L. brevis SAD displayed the highest co-aggregation increment (%) against Staphylococcus aureus, while L. plantarum KAD demonstrated potent antimicrobial activity. In vitro analyses postulated potential health benefits related to antidiabetic properties, particularly inhibiting α-amylase and α-glucosidase enzymes. L. brevis SAD exhibited the highest α-glucosidase inhibitory activity, while L. plantarum KAD displayed the most potent α-amylase inhibitory activity. Comprehensive safety assessments, including antibiotic susceptibility profiling, hemolytic activity evaluation, and in vivo acute toxicity studies, confirmed the suitability of these LAB isolates for human consumption.ConclusionsThe isolates show promising probiotic characteristics and significant potential in addressing metabolic health. These results carry substantial scientific implications, suggesting the pharmaceutical-based applications of these traditional fermented foods. Further in vivo investigation is recommended to fully elucidate and exploit the health benefits of these LAB isolates, opening avenues for potential therapeutic interventions and the development of functional foods.

Surface and Aggregation Properties of Rhamnolipids in Water–Bioethanol Mixtures: A Step toward Green Formulation Design

Water–ethanol mixtures are largely exploited for many different applications, from industrial processes to pharmaceutical formulations. Surfactants are often added to tune their interfacial properties. Sustainability concerns require redesigning such blends to minimize their environmental impact. A successful approach is to replace synthetic oil-based components with affordable unpurified bio-derived alternatives. In this respect, we have characterized aqueous mixtures of bioethanol, obtained by the fermentation of algae, and rhamnolipids, biosurfactants of microbial origin. The physico-chemical characterization of water–bioethanol binary mixtures in terms of refractive index, density, viscosity, and surface tension indicates that bioethanol behaves like pure ethanol with negligible effects of impurities. Analysis of tensiometric titrations shows that, at bioethanol contents higher than 20–30% bioethanol mass percent, rhamnolipid aggregation is impaired, whereas surface adsorption at the water–air interface remains poorly affected. Overall, bio-derived components can be proposed as a promising alternative to oil-derived chemicals in eco-sustainable formulations.

ANALYSIS OF THE QUALITY OF FABA (FLY ASH BOTTOM ASH) BASED CONCRETE AS AN FINE AGGREGATE SUBSTITUTE WITH REFERENCE TO MIXTURE PROPORTION IN WORK UNIT PRICE ANALYSIS

In this research, the author used FABA (Fly Ash Bottom Ash) waste as an alternative to fine aggregate. This research can determine the physical properties of faba aggregate with the results of sieve analysis testing of faba aggregate which has a fineness modulus value of 2.34 which is included in the medium fine aggregate type. Testing for water content in faba fine aggregate in SSD conditions was 3.09%. Faba fine aggregate sludge content is 0%. Testing the organic substances on the faba fine aggregate showed that the NaOH color was reddish brown, because it needed to be washed first before being used as a concrete mixture. The face dry specific gravity of faba fine aggregate is 2.2 gr/cm2. Therefore, faba aggregate can be used as a substitute for sand because it has physical properties that meet the requirements as fine aggregate. Results The final compressive strength of faba concrete and normal concrete as a control at the age of 7 days and 28 days has reached the planned quality, but the compressive strength at normal concrete (control) is higher than faba concrete. With the results of the standard deviation values ​​at 7 days and 28 days, it is included in perfect workmanship condition because it has a standard deviation value of less than 3 MPa. The results of the concrete flexural strength test were only normal K300 concrete with a flexural strength of 4.60 MPa, which complies with SNI 2847:2013, namely producing a minimum flexural strength of fs = 4.4 MPa. Normal concrete has a much higher flexural strength than faba concrete, and the higher the quality of the planned concrete, the greater the resulting flexural strength of the concrete.

Impact of pre-soaked lime water carbonized recycled fine aggregate on mechanical properties and pore structure of 3D printed mortar

Compared to natural fine aggregate, recycled fine aggregate has disadvantages such as high water absorption and poor strength. Accelerated carbonization is considered a method to enhance recycled aggregate performance. However, the lack of substances available for carbonation reaction in old cement mortar restricts the enhancement of RFA performance. In this study, a pre-soaked lime-water carbonization method was employed to enhance carbonization efficiency and improve cement mortar performance by introducing additional sources of calcium. Therefore, the focus was on investigating the effects of pre-soaked lime-water carbonization-treated recycled fine aggregate with different replacement ratios (0%, 30%, 50%, 70%, 100%) on the mechanical properties of 3D printed mortar. In addition, combining XRD、SEM-EDS, and X-CT microscale testing methods, the study analyzed the influence of carbonized recycled fine aggregate on the pore structure of 3D printed recycled mortar. The purpose was to reveal the reinforcement mechanism of pre-soaked lime water composite carbonization. Experimental results showed that the pre-soaked lime water carbonization method improved the physical properties of recycled fine aggregate, with the most significant decrease in the water absorption ratio, which decreased by 53.89%. Incorporating appropriate carbonized recycled fine aggregate can enhance the mechanical properties of 3D printed mortar, increase interlayer bonding strength, reduce mechanical anisotropy and overall porosity, and improve pore defects. Defects on the aggregate surface are filled with CaCO3 carbonization products, improving the pore structure and strengthening the interfacial transition zone, thus enhancing the resistance of 3D printed recycled mortar to external forces. The findings of the present work not only improve the utilization of recycled sand but also provide methods and ideas for improving the properties of 3D printed recycled mortar.

Exploring the physical and mechanical characteristics of multi-generation recycled aggregate concrete at equivalent compressive strengths

The concrete industry has been responsible for significant depletion of natural resources and at end-of-life significantly contributes to global waste production. To date experimental studies have typically explored the use of single generation recycled aggregates (RA) in concrete production, however, to move towards a circular economy the concrete industry needs to embrace the use of multi-generation recycled aggregate concrete (MGRAC). In this paper the physical and mechanical performance of 45 concrete mix designs over 4 generations of concrete production is explored. At each generation a series of mixes are conducted at various water to cement ratios (w/c) and with a range of blends of virgin and recycled aggregates from differing generations to capture the impact on material properties. The physical and mechanical properties are quantified for both the aggregates and the concretes at each generation. The results show that the physical properties and some mechanical properties of the concrete and RA decrease with respect to virgin aggregate concrete and virgin aggregate but, implementing a 50% replacement of VA can slow down intergenerational degradation. Furthermore, the blending RA from a range of generations can also slow intergenerational degradation but to a lesser extent. Effective aggregate properties are determined, and direct relationships confirmed indicating potential for informed mix design based on an understanding of a few simple aggregate properties.

Review of Treatment Methods for Enhancing Recycled Concrete Aggregates Properties

Abstract: The use of recycled concrete aggregates (RCA) as a potential substitute for natural aggregates in concrete production has been recommended by many research studies due to the environmental and cost benefits associated with it. However, due to RCA’s high-water absorption, its engineering properties are lower than natural aggregates (NA). Therefore, researchers have also suggested various pretreatment methods to enhance RCA's mechanical and durability properties, including thermal, mechanical, and chemical treatment. In this study, an attempt has been made to investigate the combined effect of heat, abrasion, and fly ash slurry pretreated RCA on the workability and compressive strength of recycled aggregate concrete (RAC) using superplasticizer for 0.4, 0.5, and 0.6 w/c ratio. The study results show that pretreatment of RCA along with the addition of superplasticizer can lead to higher workability and compressive strength of recycled aggregate concrete (RAC) compared to untreated RCA.

Physicochemical and foam properties of ovalbumin-carboxymethylcellulose mixtures after mild heat treatment: Comparison of electrostatic repulsion and attraction

The effects of electrostatic repulsion (pH6.5) and attraction (pH4.6) between biopolymers on the physicochemical and foam properties of ovalbumin (OVA)/carboxymethylcellulose (CMC) mixtures subjected to mild heat treatment (60–75 °C) were comparatively investigated. It was found that electrostatic binding between OVA and CMC at pH 4.6 resulted in an increase in the peak temperature of thermal denaturation (Td) of OVA from 71.3 °C to 74.4 °C, while no significant effect was observed at pH 6.5. Thus, 60 and 65 °C below Td were chosen to further investigate the effects of heating on the degree of thermal aggregation, protein conformation and foam properties of OVA/CMC mixtures. Confocal laser scanning microscopy observations and rheological results indicated that electrostatic binding between OVA and CMC at pH 4.6 significantly reduced the degree of protein thermal aggregation, while on the contrary, electrostatic repulsion between proteins and polysaccharides at pH 6.5 promoted OVA thermal aggregation. Raman spectroscopic characterisation indicated that mild heat treatment mainly led to a change in the microenvironment polarity of OVA tyrosine and tryptophan residues, as well as an increase in the content of random coil in the amide III band irrespective of pH. Moreover, after heating at 65 °C for 20 min, The foaming ability of the OVA/CMC mixtures at pH 6.5 and 4.6 increased by approximately 32% and 36% respectively compared to pure OVA. These findings have a positive value for enhancing the heat sterilisation strength of egg white proteins.

Synthesis and characterization of bentonite-based lightweight ceramic aggregates using coal combustion residue and kerosene bloating agent

Coal combustion residue (CCR) is an industrial by-product that has been widely adopted in civil engineering applications. However, a significant portion of CCR is still left unused around the world. This study investigates the feasibility of incorporating CCR into ceramic aggregates to enhance their engineering properties. Through a combination of kerosene as a bloating agent and CCR addition, the study demonstrates significant improvements in ceramic aggregate properties. Particle strength ranged from 0.33 to 8.53 MPa, with density variations between 0.39 and 0.95 g/cm³. Additionally, the additives also promoted the crystallization process, as shown by the increase in crystallinity from 40.67% to 61.87%. This was confirmed by the X-ray diffraction analysis, which revealed the changes in the mineral composition and crystallinity due to the additives. Furthermore, the micro and macro pores of bentonite profoundly influence the bloating process of aggregate, contributing to the formation of a well-distributed porous structure in ceramic pellets. The resulting ceramic aggregate exhibited favorable strength-to-density ratios suitable for both structural and non-structural concrete applications. This research highlights the potential of CCR utilization in ceramic aggregates, offering sustainable solutions for the construction industry while mitigating waste disposal concerns.

Investigating the Dynamic Creep and the Tensile Performance of Zeolitic Tuff-modified Warm Asphalt Mixtures

Aims This research investigates the effect of adding natural Jordanian Zeolitic tuffs to the SUPERPAVE asphalt mixture at the dynamic creep and the indirect tensile performance. Background Rutting and fatigue are considered the most common types of distress that affect pavements all over the world. Many factors can affect these properties, such as different aggregate properties, asphalt grades, and properties, as well as the type and amount of the mineral filler. Mineral fillers play an important role in enhancing the asphalt mixtures' performance by filling the voids in the mixture besides improving the cohesion of the binder as it has a small weight in addition to a very large surface area. Generally, the powder of limestone is the most used type of filler. However, studies showed that many materials could also be used as mineral fillers successfully. The focus of this study is using natural Jordanian Zeolitic tuff as a mineral filler. Jordanian zeolitic tuff mainly consists of Phillipsite, chabazite, and faujasite, which are considered the most abundant Zeolitic tuff minerals. The pyroclastic material is widely distributed in the Badia region of northeast Jordan. Zeolitic tuffs are located in Jabal Aritayn (30km northeast of Azraq), Tlul AlShahba (20 km east of Al Safawi), Tal Al-Rimah (35 km northeast of Al Mafraq), and other small deposits in central and south Jordan. Objectives The aim of this research was to study the impact of Zeolitic tuffs on overall Superpave asphalt mixture performance. Methods The specimens were prepared using the optimum asphalt content obtained by the SUPERPAVE method. Dynamic Testing System DTS-16 was used to apply both dynamic creep and indirect tensile tests that give a good idea about the rutting and fatigue behavior of asphalt mixtures. Both tests were conducted at 25 °C. Results The Zeolitic tuffs modified asphalt mixtures have lower accumulated strains and higher creep stiffness compared to the control mixture. Subsequently, the indirect tensile test results showed that the modified asphalt mixtures have a higher resilient modulus than the control asphalt mix. Generally, using Zeolitic tuffs as a modifier of asphalt mixtures enhanced the rutting and fatigue resistance. The results showed that asphalt mixtures fortified with 25% Zeolitic tuffs emerged as the best contenders for rutting resistance. Also, mixtures enriched with 50% Zeolitic tuffs stood out in fatigue resistance performance. Conclusion The best dynamic creep performance was by adding 25% Zeolitic tuffs by the mineral filler mass, while the best resilient modulus was by adding 50% Zeolitic tuffs by the mineral filler mass. Other The overarching goals encompass understanding the dynamic creep behavior of Zeolitic tuff-infused asphalt blends, deciphering its indirect tensile performance, pinpointing the ideal replacement ratio for mineral fillers, and drawing a performance comparison between WMA and conventional Hot Mix Asphalt (HMA) compositions.

One-Pot synthesis and interfacial activity of imidazolium ionic liquid surfactants with double-chain hydrophobic

Three double-chain imidazolium ionic liquid surfactants (ILS) with varying alkyl lengths, namely [C10mimC10][OAc], [C12mimC12][OAc], and [C14mimC14][OAc], were synthesized via the one-step Debus-Radziszewskireaction. The chemical structures of these three ILS were confirmed through FT-IR, 1H NMR and ESI-MS analyses. Their surface/interface activity, wetting ability, thermal stability, and aggregation properties were investigated. The results indicated that the presence of double-chain hydrophobic groups in ILS exerted a significant influence on their surface/interface activity. Surface activity and micellization properties were assessed using surface tension measurements, revealing that the micellization process of double-chain ILS was more favorable compared to single-chain ILS. Among the three ILS examined, [C14mimC14][OAc] exhibited the lowest surface tension and critical micelle concentration (CMC) values, measuring 29.07 mN/m and 1.64 × 10-2 mmol/L, respectively. Solutions containing approximately 50 ppm of these ILS could reduce interfacial tension to below 1 mN/m. Additionally, the contact angle decreased to less than 90° within 90 s. The formation of aggregates in aqueous solutions was found to be influenced by the number of CH2 units present in the different ILS molecules.

The nuclear import receptor Kapβ2 modifies neurotoxicity mediated by poly(GR) in C9orf72-linked ALS/FTD

Expanded intronic G4C2 repeats in the C9ORF72 gene cause amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). These intronic repeats are translated through a non-AUG-dependent mechanism into five different dipeptide repeat proteins (DPRs), including poly-glycine-arginine (GR), which is aggregation-prone and neurotoxic. Here, we report that Kapβ2 and GR interact, co-aggregating, in cultured neurons in-vitro and CNS tissue in-vivo. Importantly, this interaction significantly decreased the risk of death of cultured GR-expressing neurons. Downregulation of Kapβ2 is detrimental to their survival, whereas increased Kapβ2 levels mitigated GR-mediated neurotoxicity. As expected, GR-expressing neurons displayed TDP-43 nuclear loss. Raising Kapβ2 levels did not restore TDP-43 into the nucleus, nor did alter the dynamic properties of GR aggregates. Overall, our findings support the design of therapeutic strategies aimed at up-regulating Kapβ2 expression levels as a potential new avenue for contrasting neurodegeneration in C9orf72-ALS/FTD.

Formation of hydrophilic co-assemblies with improved functional properties between tilapia protein isolate and sodium caseinate

Functional enhancement of aquatic proteins still faces great challenges, resulting in their highly under-utilized applications in the field of intensive food processing. In this study, the tilapia protein isolate-sodium caseinate co-assemblies were prepared using a pH cycle strategy. The aggregation properties, component interactions, and functional properties of the formed co-assemblies were investigated. Results of particle size, zeta potential, surface hydrophobicity, and SEM indicated that tilapia protein isolates and sodium caseinate generated co-assemblies with reduced aggregation properties. Component interactions revealed that sodium caseinate binds to tilapia protein isolate mainly through hydrogen bonding and hydrophobic interactions, which inhibits the refolding of tilapia protein isolate to form more structurally ordered hydrophilic co-assemblies. Functional properties studies showed that co-assemblies with improved water solubility (reached 77.08%) and emulsification properties compared to tilapia protein isolated when the mass ratio of tilapia protein isolated to sodium caseinate was T/N = 1:1. In this experiment, the functional properties of tilapia protein isolate were enhanced by a simple, green, and efficient method, which is expected to be applied in the food industry.

Aggregation of graphene oxide upon the stripping of oxidized debris: An experimental and molecular dynamics simulation study

The most recent structural study of graphene oxide (GO) indicates that the oxidized debris (ODs) adhered to as-prepared GO will strip in certain aquatic settings. The impact of ODs stripping on the characteristics of GO has been widely reported, but its effects on GO aggregation have received less attention. Here, the influence of OD stripping on the GO aggregation property was identified, and the aggregation of as-prepared GO and GO upon OD stripping was compared. Upon ODs stripping, the pKa values of GO shifted from 3.91, 6.25, and 9.84 to 4.54, 6.65, and 10.21, respectively. Further analysis indicated the removal of ODs reduced the net negative charge and improved the hydrophobicity of GO, hence promoting the aggregation of GO. The acceleration of GO-Ca2+-OD aggregate formation was facilitated by the collective effects of ODs stripping, functional group deprotonation, double layer compression, OD bridging, and charge neutralization. The metal ions and stripped ODs attach to GO edges and link GO, which perform like bridges and contribute to further aggregation. In general, the existence of ODs adds complexity to the constructions and characteristics of GO, and it is important to take this into account while evaluating the aggregation characteristic of GO-based materials.

Pro-Hemorrhagic Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy Associated with NOTCH3 p.R75P Mutation with Low Vascular NOTCH3 Aggregation Property.

Intracerebral hemorrhage (ICH) and cerebral microbleeds (CMB) in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy are more common in East Asian populations than in people of white European ancestry. We hypothesized that the ethnic difference is explained by the East Asian-specific NOTCH3 p.R75P mutation. This retrospective observational study included 118 patients with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy in Japanese and Korean cohorts. We investigated whether the p.R75P mutation is associated with symptomatic ICH and multiple CMB (>5) using quasi-Poisson regression models. We predicted the NOTCH3 extracellular domain protein structures in silico and graded NOTCH3 extracellular domain immunostaining in skin vessels of some patients, with subsequent comparisons between p.R75P and other conventional mutations. Among 63 Japanese patients (median age 55 years; 56% men), 15 had a p.R75P mutation, significantly associated with symptomatic ICH (adjusted relative risk 9.56, 95% CI 2.45-37.31), multiple CMB (3.00, 1.34-6.71), and absence of temporopolar lesions (4.91, 2.29-10.52) after adjustment for age, sex, hypertension, and antithrombotics. In the Korean cohort (n = 55; median age 55 years; 51% men), the p.R75P mutation (n = 13) was also associated with symptomatic ICH (8.11, 1.83-35.89), multiple CMB (1.90, 1.01-3.56), and absence of temporopolar lesions (2.32, 1.08-4.97). Structural analysis revealed solvent-exposed free cysteine thiols in conventional mutations, directly causing aggregation, whereas a stereochemically incompatible proline residue structure in p.R75P lowers correct disulfide bond formation probability, indirectly causing aggregation. Pathologically, the p.R75P mutation resulted in less vascular NOTCH3 extracellular domain accumulation than the other conventional mutations. NOTCH3 p.R75P mutation is associated with hemorrhagic presentations, milder temporopolar lesions, and distinct mutant protein structure properties. ANN NEUROL 2024;95:1040-1054.

Sprouted Oats (Avena sativa L.) in Baked Goods: From the Rheological Properties of Dough to the Physical Properties of Biscuits

AbstractThis study investigated the impact of sprouted oats (SO) on dough properties and biscuit features. Unsprouted oats (USO) and SO (for 48 h and 72 h) were studied in wheat dough at 10, 20, and 30%, and gluten aggregation, mixing, and extensional properties were evaluated. USO caused a weakening in gluten aggregation capacity, an increase in water uptake, development time and dough rigidity, and a decrease in extensibility. Dough enriched in SO showed mixing profiles similar to wheat, but using SO strongly affected dough extensional properties, indicating gluten weakening. Changes in rheological properties suggested the use of SO at 20% level in biscuit production. Using oats did not affect either biscuit size or volume, but decreased both the hardness and the toughness of the product, with 72 h-SO having the greatest impact, especially on hardness. Further study will address consumer acceptability and nutritional features of the developed baked product.

Pedestrian tracking method based on S-YOFEO framework in complex scene

A real-time stable multi-target tracking method based on the enhanced You Only Look Once-v8 (YOLOv8) and the optimized Simple Online and Realtime Tracking with a Deep association metric (DeepSORT) for multi-target tracking (S-YOFEO) is proposed with the aim of addressing the issue of target ID transformation and loss caused by the increase of practical background complexity. For the purpose of further enhancing the representation of small-scale features, a small target detection head is first introduced to the detection layer of YOLOv8 in this paper with the aim of collecting more detailed information by increasing the detection resolution of YOLOv8. Secondly, the Omni-Scale Network (OSNet) feature extraction network is implemented to enable accurate and efficient fusion of the extracted complex and comparable feature information, taking into account the restricted computational power of DeepSORT’s original feature extraction network. Again, a novel adaptive forgetting Kalman filter algorithm (FSA) is devised to enhance the precision of model prediction and the effectiveness of parameter updates to adjust to the uncertain movement speed and trajectory of pedestrians in real scenarios. Following that, an accurate and stable association matching process is obtained by substituting Efficient-Intersection over Union (EIOU) for Complete-Intersection over Union (CIOU) in DeepSORT to boost the convergence speed and matching effect during association matching. Last but not least, One-Shot Aggregation (OSA) is presented as the trajectory feature extractor to deal with the various noise interferences in the complex scene. OSA is highly sensitive to information of different scales, and its one-time aggregation property substantially decreases the computational overhead of the model. According to the trial results, S-YOFEO has made some developments as its precision can reach 78.2% and its speed can reach 56.0 frames per second (FPS).

Emphasis of Cyclic Loading on the Fracture Mechanism and Residual Fracture Toughness of High-Performance Concrete Considering the Morphological Properties of Aggregate

This research investigates the fatigue behaviour and fracture mechanics of high-performance concrete (HPC), including various compositions such as HPC with basalt aggregates (HPC-B), HPC with gravel (HPC-G), and high-strength coarse mortar (CM) under static and cyclic tensile loading within the special priority program SPP 2020. The study aims to integrate fracture mechanics into structural analysis to enhance design guidelines for slender cross-sections and safety-related high-performance structural components. The experimental investigations reveal HPC-B’s remarkable superiority, displaying its higher compressive strength, modulus of elasticity, and tensile strength compared to HPC-G and CM. A modified disk-shaped compact tension (MDCT) based on ASTM standards, aided by digital image correlation (DIC) unveils fracture behaviour, emphasizing fracture energy as a crucial parameter. HPC-B exhibits improved crack resistance and notch sensitivity reduction attributed to crushed basalt aggregates and an enhanced interfacial transition zone (ITZ). The research scrutinizes factors like material characterization, aggregate morphology, stress levels, and the displacement rate on crack formation. High-cycle fatigue tests show HPC-B’s superior performance, and the post-fatigue analysis reveals enhanced residual fracture toughness attributed to nano-level structural changes, stress redistribution and aggregate-matrix interaction. A 3D image analysis via Computed Tomography (CT) scans captures mesostructural crack propagation and provide quantitative insights. This research marks a significant shift from conventional aggregate-focused approaches and introduces a novel approach by integrating excess paste theory and mesoscale analysis, highlighting the critical role of aggregate choice in material characterization and mesoscale design in enhancing the structural efficiency of HPC. Furthermore, the study advances the understanding of HPC fatigue behaviour, emphasizing the interplay of aggregate types and morphologies and their dynamic response to cyclic loading, offering valuable insights for optimizing design guidelines and fostering innovation in structural engineering.

Prediction models for the flux decay profile and initial flux of microfiltration for therapeutic proteins.

Microfiltration (MF) is an essential step during biopharmaceutical manufacturing. However, unexpected flux decay can occur. Although the flux decay profile and initial flux are important factors determining MF filterability, predicting them accurately is challenging, as the root cause of unexpected flux decay remains elusive. In this study, the methodology for developing a prediction model of flux decay profiles was established. First, the filtration profiles of different monodisperse polystyrene latex and silica beads of various sizes were evaluated. These results revealed that the size and surface electrostatic properties of the beads affect the flux decay profile. Taking the size and surface electrostatic properties of protein aggregates into account, we constructed a predictive model using model bead filtration profiles. We showed that this methodology was applicable to two different MF filters to predict the flux decay profile of therapeutic proteins. Because our proposed prediction model is based on normalized flux, the initial flux is required to predict the overall filtration profile. Then, we applied the Hagen-Poiseuille equation using sample viscosity values to estimate the initial flux. The developed prediction models can be used for effective MF scale-up assessment during the early stages of process development.

Rheological behavior of hydrophobic association polyacrylamides with high salt resistance and corrosion inhibition: Cross-linking modification based on trace dopamine hydrochloride derivatives

Hydrophobic association polyacrylamides (HAPAMs) have great potential for use in polymer flooding because of their unique aggregative, hygroscopic, and other compatible properties; however, their poor solubility in high-salt reservoir environments is one of the drawbacks of current polymers for enhanced oil recovery (EOR) applications. Herein, an amphipathic hydrophobic monomer (hexadecyldimethylallyl ammonium chloride, DMAAC16) and a dopamine hydrochloride-derived monomer (DAAM) were successfully introduced into HAPAM to synthesize novel dopamine hydrochloride-modified hydrophobic association polymers (HAPAMC16D). As a result, HAPAMC16D exhibited not only good comprehensive properties based on its porous network structure but also excellent viscosity due to the presence of the DAAM monomer. When the concentration of the polymer solution was greater than the critical association concentration (CAC), the apparent viscosity reached 614 mPa s at 5 g/L C16D5. Importantly, the salt resistance increased significantly in the representative sodium and calcium ion tests, which was attributed to the degree of chemical cross-linking and the intermolecular hydrophobic bonding force. The temperature and salt resistance tests simulating different environments for EOR showed that C16D4 had an apparent viscosity of 158 mPa s, a retention rate of 28.52 % at 90 °C and a total dissolved solids (TDS) greater than 30,000. Additionally, the weight loss method and electrochemical experiments indicated that the highly salt-resistant hydrophobic association polymers had favorable corrosion inhibition effects, with an inhibition efficiency of up to 99.02 % in the 1 M hydrochloric acid-Q235 carbon steel system. This hydrophobic association strategy provides a new approach for designing highly salt-resistant materials for polymer flooding in harsh reservoir environments.

Effect of reaction and post-treatment conditions on physico-chemical properties of magnetic iron oxide nano-particles

Poor stability and dispersibility, as well as aggregation are considered as major challenges in clinical application of iron oxide nanoparticles (IONPs). Several studies have shown that the synthesis parameters and post-synthesis treatments e.g., drying methods, have the capability to improve the particles' characteristics. Herein, we investigate the combined effect of synthesis and post-treatment parameters on the particle size, stability and magnetism of IONPs. Magnetite (Fe3O4) NPs were prepared via co-precipitation and post-treated using different methods, i.e. (i) freeze dried at –53 °C, 0.133 mbar for 48 h (liquid nitrogen frozen (LFD) and freezer frozen (FFD)), (ii) vacuum oven dried (VOD) at 60 °C for 24 h, and (iii) kept wet colloidal (WET), dispersed in deionized water. The Fe3O4 NPs’ chemical functional groups, size, shape, crystallinity, stability, aggregation, porosity, and magnetic properties were further analysed using different characterisation techniques. Analytical results showed that, while the WET sample had the best stability and significantly less aggregation at different temperatures, amongst post-treated Fe3O4 NPs, LFD sample exhibited the best stability (up to 37 °C), dispersion and smallest polydispersity index. Furthermore, all dried NPs had superparamagnetic characteristics, while, LFD Fe3O4 NPs had better magnetic properties and stability than other drying methods.