Activator Concentration Research Articles

Glass-ceramic materials: influence of fluoride nanocrystals on emission properties of lanthanide ions

In this work, the oxyfluoride glass-ceramic materials containing LaF3 nanocrystals, prepared by using the sol-gel method, were described. The influence of fluoride nanocrystals on the photoluminescence properties of selected lanthanide ions was determined. The experimental results obtained for nano-glass-ceramics were compared to the precursor xerogels. Those Ln3+-doped sol-gel materials with dispersed LaF3 nanocrystals exhibit several visible emission bands. It was observed that heat-treatment process caused the elongation of the lifetimes of the 5D0 state from τ = 0.22 ms to τ1 = 0.79 ms, τ2 = 9.76 ms (for Eu3+-doped materials) and of the 4F9/2 state from τ = 0.027 ms to τ1 = 0.034 ms, τ2 = 1.731 ms (for Dy3+‑doped materials). The performed studies clearly revealed that luminescence behaviour also depends on an activator concentration and a distribution of energy levels of lanthanide ions.

3D printable earth-based alkali activated “ink”: Effect of alkali concentration and binder-to-aggregate ratio

This research attempts to investigate the effect of activator concentration (4 mol/L (M) and 8M) and binder-to-aggregate (B:A) ratio (ranging from 1:1 to 1:3 by weight) on extrudability and buildability of 3D printable natural earth-based alkali-activated materials (EAAM). It is found that natural clay in soil, used to replace 25 % of M-sand, imparts higher thixotropy, evident from 90 to 100 % recovery in viscosity compared to 65–80 % for corresponding control (containing only M-sand and no soil). Presence of clay increases the dynamic yield stress than control but reduces the plastic viscosity by 80 – 90 % in EAAM compared to corresponding control where interlocking between sand particles resists smooth extrusion of the material. EAAMs made with 8M NaOH have higher flow retention and maintain 95–100 % recovery in viscosity for longer duration than 4M EAAM. This contributes to superior extrusion quality of 8M EAAM than 4M EAAM. The findings suggest that binder content can be reduced as concentration of NaOH is increased from 4M to 8M. This is evident from lower layer deformation (0.09 % of original height) under self-weight and higher 3D printed buildable height of at least 457 mm in 8M EAAM with B:A of 1:2 compared to a maximum of 375 mm for 4M EAAM at higher B:A of 1:1. Ratios of wet compressive strength to dry compressive strength vary between 0.92 and 1.09 in 8M EAAM compared to 0.79 – 0.85 for 4M EAAM at 28-day age, suggesting lower sensitivity to moisture due to improved clay stabilization. Based on the strength and moisture sensitivity, the developed material can serve as a low-carbon and durable alternative to Portland cement in the construction of masonry elements in buildings, including cavity walls, panels, flooring tiles and façade members.

Spectroscopic analysis of Nd3+doped Ba3Bi(PO4)3 phosphor for near-infrared laser application

Near infrared (NIR) emission plays a crucial role in various applications, driving ongoing research to identify new hosts capable of NIR emission. This article explores NIR emission in the Ba3Bi(PO4)3 host. X-ray diffraction (XRD) patterns confirm that the Ba3Bi(PO4)3 belongs to Eulytite family (I4¯3d). Electron micrographs revealed the development of heterogeneous microstructures with noticeable agglomeration. Nd3+ was used as an activator to achieve NIR emission. In the emission spectra characteristic lines were observed. Among them the one at 1062 nm (Nd3+: 4F3/2 → 4I11/2) is the most intense. Results on the effect of increasing activator concentration on luminescence intensity are also presented. The highest intensity is observed for the composition Ba3Bi0.095Nd0.05(PO4)3. A decrease in intensity beyond 5.0 mol% is attributed to concentration quenching. Based on these findings, the critical distance, Rc was evaluated as 22.29 Å. These results indicate that the optimized Nd3+doped Ba3Bi(PO4)3 phosphor has potential as NIR-emitting materials for laser applications and infrared bioimaging.

Rosuvastatin Flexible Chitosomes: Development, In Vitro Evaluation and Enhancement of Anticancer Efficacy Against HepG2 and MCF7 Cell Lines.

Rosuvastatin (ROS), a statin drug with promising anticancer properties has a low bioavailability of approximately 20% due to lipophilicity and first-pass metabolism. This study aimed to enhance ROS anticancer efficacy through loading into flexible chitosomes. The chitosomes were prepared starting from negatively charged liposomes through electrostatic interactions with chitosan. The conversion of zeta potential from negative to positive confirmed the successful formation of chitosomes. The chitosan coating increased the particle size and zeta potential, which ranged from 202.0 ± 1.7nm to 504.7 ± 25.0nm and from - 44.9 ± 3.0 mV to 50.1 ± 2.6 mV, respectively. Chitosan and drug concentrations had an important influence on the chitosome properties. The optimum chitosome formulation was used to prepare ROS-loaded flexible chitosomes using different concentrations of four edge activators. The type and concentration of edge activator influenced the particle size, drug entrapment efficiency, and drug release rate of the flexible chitosomes. Flexible chitosomes significantly increased drug permeation through rat abdominal skin compared to control transferosomes and drug solution. The optimal ROS flexible chitosomes containing sodium deoxycholate as an edge activator had a 2.23-fold increase in ROS cytotoxic efficacy against MCF7 cells and a 1.84-fold increase against HepG2 cells. These results underscore the potential of flexible chitosomes for enhancing ROS anticancer efficacy.

Rupture mechanics of blood clots: Influence of fibrin network structure on the rupture resistance

Embolization is a leading cause of mortality, yet we know little about clot rupture mechanics. Fibrin provides the main structural and mechanical stability to blood clots. Previous studies have shown that altering the concentration of coagulation activators (thrombin or tissue factor (TF)) has a significant impact on fibrin structure and viscoelastic properties, but their effects on rupture properties are mostly unknown. Toughness, which corresponds to the ability to resist rupture, is independent of viscoelastic properties. We used varying TF concentrations to alter the structure and toughness of human plasma clots. We performed single-edge notch rupture tests to examine fibrin toughness under a constant strain rate and we assessed viscoelastic mechanics using rheology. We utilized fluorescent confocal and scanning electron microscopy (SEM) to quantify the fibrin network structure under varying TF concentrations. Our results revealed that increased TF concentration resulted in increased number of fibrin fibers with a reduction in network pore size, thinner and shorter fibrin fibers. Increasing TF concentration yielded a maximum toughness at mid-TF concentration, such that fibrin diameter and number of fibers underlie a complex role in influencing the rupture resistance of blood clots, resulting in a nonmonotonic relationship between TF and toughness. A simple mechanical model, built on our findings from our Fluctuating Spring (FS) computational model, adopted to estimate the fracture toughness (critical energy release rate) as a function of TF predicts trends that are in good agreement with experiments. The differences in mechanical responses point to the importance of studying the structure-function relationships of fibrin networks, which may be predictive of the tendency for embolization. Statement of significanceFibrin, a naturally occurring biomaterial, is the main mechanical and structural scaffold of blood clots that provides the necessary strength and stability to the clot, ensuring effective stemming of bleeding. The rupture of blood clots can result in the blockage of downstream vessels thereby blocking blood flow and oxygen supply. The fibrin network structure has been shown to influence the viscoelastic mechanical properties of clots, but has not been explored for fracture mechanics. Here, we modulate the fibrin network structure by varying the concentration of Tissue Factor (TF). Interestingly, the association between TF concentration and maximum toughness of the clots is non-monotonic. The variations in mechanical responses highlight the importance of studying the structure-function relationships of fibrin networks, as these may predict the tendency for embolization.

Behavior of zero cement reinforced concrete slabs under monotonic and impact loads: Experimental and numerical investigations

Currently, there is a shift toward the use of low-carbon construction materials to reduce global carbon dioxide emissions. Zero-cement concrete (ZCC) synthesized from alkaline activated fly ash (FA) is a promising alternative for Portland cement in the construction industry to reduce global CO2 emissions, increase the consumption of waste materials, and save energy. A substantial amount of research on the impact load behavior of ordinary reinforced concrete (RC) structural components has been conducted. However, investigations on the behavior of zero cement concrete (ZCC) slabs under impact loads have not been reported. In this work, twenty simply supported two-way flat reinforced fly ash ZCC slabs (including two normal concrete (NC) slabs as reference samples) were tested under monotonic and impact loads. The test samples were categorized into eight groups on the basis of various parameters. Twelve RC slabs (1 NC and 11 ZCCs) were prepared for repeated impact tests, and eight slabs (1 NC and 7 ZCCs) were prepared for monotonic loading tests. Various parameters were investigated herein, including slab thickness, bar spacing, molarity concentration of alkali activators, hammer height, and hammer mass. Nonlinear finite element models were also developed and validated by using ABAQUS software for additional parametric study purposes. The results revealed that the behavior of ZCC slabs is approximately similar to that of NC slabs. The results also revealed that an increase in the ZCC slab thickness, reinforcement ratio, hammer height, and hammer mass has a noticeable effect on the dynamic response of the slab. However, increasing the molarity concentration of alkali activators has clearly a slight influence on the impact loadtime history. When the slab thickness was increased or the bar spacing was reduced, the static and impact energy absorption capacities were increased by 1.5 and 2.0 times, respectively. For impact load tests, the damage degree, penetration, and cracking pattern at failure were approximately typical for all test samples at the first hit except when the hammer mass and impact height were changed. For the samples subjected to monotonic loading, a flexural response was observed for almost all the slab samples at the first loading stage, and cracking started from the midpoint of the slab and propagated toward the slab edges; ultimately, punching shear failure was observed.

Suppressed concentration quenching and tunable photoluminescence in Eu2+-activated Rb3Y(PO4)2 phosphors for full-spectrum lighting

Highly efficient inorganic phosphors are desirable for lighting-emitting diode light sources, and increasing the doping concentration of activators is a common approach for enhancing the photoluminescence quantum yield (PLQY). However, the constraint of concentration quenching poses a great challenge for improving the PLQY. Herein, we propose a fundamental design principle by separating activators and prolonging their distance in Eu2+-activated Rb3Y(PO4)2 phosphors to inhibit concentration quenching, in which different quenching rates are controlled by the Eu distribution at various crystallographic sites. The blue-violet-emitting Rb3Y(PO4)2:xEu (x = 0.1%–15%) phosphors, with the occupation of Rb1, Rb2 and Y sites by Eu2+, exhibit rapid luminescence quenching with optimum external PLQY of 10% due to multi-channel energy migration. Interestingly, as the Eu concentration increases above 20%, Eu2+ prefer to occupy the Rb1 and Y sites with separated polyhedra and large interionic distances, resulting in green emission with suppressed concentration quenching, achieving an improved external PLQY of 41%. Our study provides a unique design perspective for elevating the efficiency of Eu2+-activated phosphors toward high-performance inorganic luminescent materials for full-spectrum lighting.

Sintesa dan Karakteristik Karbon Aktif dari Batang Pisang Kepok (Musa acuminata) Sebagai Adsorben pada Penjernihan Minyak Goreng Bekas

Kepok banana stems have a cellulose content of 58.6466%. The cellulose content means that Kepok banana stems can be used as a basic ingredient for making active carbon. Activated carbon is a material that has high porosity and can be used for absorption which can remove impurities liquid or gas. Process for making activated carbon is cutting banana stems into small pieces and washed, then drying with sun during 7 days. After that, carbonized at 300℃ for 1 hour. Carbonizasition product were ground and sieved with a 100 mesh sieve and activated with NaOH 0.5; 0.75; 1; 1.25 and 1.5 N for 12; 18; 24; 30; and 36 hours. Then, drying in oven at temperature of 100℃ until constant weight. The best activated carbon is activator concentration of 1.5 N NaOH for 12 hours with a water content of 7.8496%, ash content of 9.7186%, and bound carbon content of 65.3479%. SEM test results of activated carbon from banana stems before application have a porous morphological structure and after application the active carbon pores are seen to be closed. Percentage reduction FFA reach 94.8057% and the reduction peroxide reach 86.8978%.

Efficient utilization of coral waste for internal curing material to prepare eco-friendly marine geopolymer concrete

To address shortages in construction materials for island engineering, tackle the accumulation of solid waste, and inhibit the shrinkage of geopolymers, coral waste was utilized as the internal curing material to prepare high-performance marine geopolymer concrete (MGC) with seawater, sea-sand, and normal limestone aggregate (LsA). The coral coarse aggregate (CorA) used in this investigation has a total porosity ranging from 50% to 58.3% with internal pore diameters spanning 50–400 μm. The water desorption of CorA followed a two-stage pattern within a relative humidity (RH) range of 75%–85%, becoming nonlinear above 90% RH, which released about 85% of its moisture within 200 h at 97% RH, demonstrating potential for internal curing. Adding a small amount of CorA to MGC increased slump and setting time by providing internal curing water. However, as CorA content exceeded 30%, the slump significantly decreased due to reduced mixing water and elevated activator concentration, while the initial setting time slightly decreased. Furthermore, the inclusion of saturated CorA in MGC significantly reduced autogenous shrinkage, with higher CorA contents (exceeding 30%) leading to slight expansion in the early stages and nearly eliminating shrinkage at contents above 40%. The greater drying shrinkage in geopolymer systems compared to ordinary Portland cement is due to capillary pressure compressing the product framework, converting larger gel pores into smaller ones. Additionally, the layered calcium aluminosilicate hydrate (C-A-S-H) gel exhibits more pronounced creep characteristics under low internal humidity conditions. The higher CorA content in MGC promoted the formation of hybrid C, N-A-S-H gel and hydrotalcite-like phases, and reduced carbonation issues. The interfacial transition zone (ITZ) between CorA and the geopolymer matrix formed a robust mechanical interlock, enhancing tensile strength and minimizing shrinkage-induced cracks. Based on overall performance and marine material utilization, an optimal substitution rate of CorA between 40% and 50% is recommended.

Physicochemical Features of Thrombin Binding to Platelet Membrane

Thrombin is a key enzyme of the blood coagulation system, which has been actively studied since the beginning of the last century. The formation of thrombin from prothrombin in the area of vessel injury leads not only to the formation of fibrin – an important structural component of the hemostatic clot – but also to the activation of platelets, endothelium and immune system cells. The binding of thrombin to the platelet surface is thought to play a critical role in the process of platelet activation and may also ensure the maintenance of a high concentration of thrombin within the thrombus due to the concentration of protease on the platelet surface. To date, all major thrombin receptors on platelets have been thoroughly characterized: through various experimental methods, the physicochemical parameters of the corresponding intermolecular interactions have been established. Since the interaction of thrombin with platelets leads to their activation, which includes changes in the number of receptors as a result of granule secretion, the interpretation of the observed kinetic binding curves faces a number of difficulties. It is known that some receptors as a result of platelet activation are able to redistribute on the membrane and form dimers and clusters, which makes the kinetics of thrombin binding to platelets an extremely complex process depending on many factors, such as activator concentrations, platelet state, and other local parameters of the system. This review aims to describe the current understanding of the interaction of thrombin with the platelet membrane and to outline important unresolved issues in this area of research. The survey provides not only information on structural and kinetic features of thrombin binding to individual platelet membrane proteins, but also analyzes the relationship between the relevant interaction parameters and previously obtained data on the integral kinetics of protease binding to the platelet surface.

Bond performance of reinforcing bars in fly ash-based engineered geopolymer composites under uniform and nonuniform corrosion conditions

While concrete is the most popular building material in the world, corrosion of the steel reinforcement in reinforced concrete (RC) structures poses ongoing durability issues. In this study, the effects of alkali activator modulus, concentration, and different corrosion periods are rigorously investigated utilizing accelerated electrochemical corrosion techniques under both uniform and nonuniform corrosion conditions. Bond stress and bond stress deterioration are evaluated to provide a thorough examination of corrosion-induced fracture formation through pull-out experiments. X-CT 3D imaging is also used to understand the spread of rust in both corrosion scenarios. Results show that mixes with lower alkali activator modulus and higher alkali activator concentration might result in better bond stress preservation and higher ultimate bond stress under corrosion. High bond stress, however, usually corresponds to a more brittle failure when subjected to pull-out force. Nonuniform corrosion treatment can result in differential rust formation and a quicker bond breakdown between steel bars and engineered geopolymer composites (EGCs) than uniform corrosion. Furthermore, under corrosion, EGCs with high alkali activator modulus tend to form more penetrating cracks with limited width and depth. Both narrow and deep penetrating fractures can arise from EGCs with low alkali activator concentration.

Characteristics candlenut shell-based activated Carbon for reduction Iron (Fe) in surface water from Bratasena Tulang Bawang, Lampung

Candlenut shells are only used as fuel, and some are thrown away, so their use has not been maximized. Because of their high carbon content, candlenut shells may be used to create adsorbents. This study looks at how different activator concentrations of KOH activators can be used to make adsorbents from candlenut shells. The study will investigate how various activator concentrations affect the ability of adsorbents based on candlenut shells to bind molecules. Furthermore, the investigation will examine the possible uses of these adsorbents in diverse sectors, including air purification and wastewater treatment. This research was carried out using the Completely Randomized Design (CRD) method, which consisted of 1 activator KOH concentration of 0.5 M, 1 M, 1.5 M, 2 M, and 2.5 M with 3 replications each. The finding demonstrated that adsorbent products activated with 0.5 M KOH yield the highest quality and satisfied SNI 06-3770-1995 requirements for an ash and water content of 10.21% and 0.98%, respectively. The adsorbent product has an iodine absorption capacity of approximately 639.39 mg/g, comparable to SNI 06-3770-1995. For iron metal, the adsorbent product exhibits an adsorption capacity and absorption efficiency of 0.14 mg/g and 98.30%, respectively. The Freundlich adsorption isotherm model is suitable for this investigation, with a Kf value of 0.14 mg/g and an R2 of 0.9999.

Paclitaxel-loaded elastic liposomes synthesised by microfluidics technique for enhance transdermal delivery.

The inherent flexibility of elastic liposomes (EL) allows them to penetrate the small skin pores and reach the dermal region, making them an optimum candidate for topical drug delivery. Loading chemotherapy in ELs could improve chemotherapy's topical delivery and localise its effect on skin carcinogenic tissues. Chemotherapy-loaded EL can overcome the limitations of conventional administration of chemotherapies and control the distribution to specific areas of the skin. In the current studies, Paclitaxel was utilised to develop Paclitaxel-loaded EL. As an alternative to the conventional manufacturing methods of EL, this study is one of the novel investigations utilising microfluidic systems to examine the potential to enhance and optimise the quality of Els by the microfluidics method. The primary aim was to achieve EL with a size of < 200nm, high homogeneity, high encapsulation efficiency, and good stability. A phospholipid (DOPC) combined with neutral and anionic edge activators (Tween 80 and sodium taurocholate hydrate) at various lipid-to-edge activator ratios, was used for the manufacturing of the ELs. A preliminary study was performed to study the size, polydispersity (PDI), and stability to determine the optimum microfluidic parameters and lipid-to-edge activator for paclitaxel encapsulation. Furthermore, physiochemical characterisation was performed on the optimised Paclitaxel-loaded EL using a variety of methods, including Dynamic Light Scattering, Fourier Transform Infrared Spectroscopy, Atomic force microscopy, elasticity, encapsulation efficiency, and In vitro release. The results reveal the microfluidics' significant impact in enhancing the EL characteristics of EL, especially small and controllable size, Low PDI, and high encapsulation efficiency. Moreover, the edge activator type and concentration highly affect the EL characteristics. The Tween 80 formulations with optimised concentration provide the most suitable size and higher encapsulation efficiency. The release profile of the formulations showed more immediate release from the EL with higher edge activator concentration and a higher % of the released dug from the Tween 80 formulations.

EFFECT OF ORGANIC LEACHATE AND RICE WASHING WATER ON COMPOSTING TIME OF ORGANIC WASTE

Waste is an integral part of human life. The increase in population is one factor that increases the waste generated. The more the population, the more activities are carried out. Organic leachate and rice washing water are environmentally friendly compost activators and are easily obtained from daily activities. Composting is a waste management strategy. Composting is an organic method through the activity of microorganisms to decompose natural materials into materials, including humus. The purpose of this study was to determine the moisture content, temperature, pH, C/N ratio, and macro nutrients during the composting process. The physical parameters of compost from the three activator concentrations showed that the treatment of P3 (with the addition of leachate formulation 20 ml/kg and rice washing water 15 ml/kg) and P2 (with the formulation adding 20 ml/kg leachate and 10 ml rice washing water), the physical compost were brownish black in color, fine textured and smelled of soil on the 22nd day. The P3 treatment has met the quality criteria of compost according to SNI 19-7030-2004, the moisture content (30%), temperature (27°C), pH (6,8), C-Organic (32,9%), Nitrogen (1,42%), Phosphor (0,65%) and Potassium (1,63%). For the C/N ratio, the result of all treatments did not meet the quality criteria of compost according to SNI 19-7030-2004. The C/N ratio of all treatments showed that it is still above the maximum standard that has been set at 20.

Combined application of mesenchymal stem cells and different glucocorticoid dosing alleviates osteoporosis in SLE murine models.

Bone mesenchymal stem cells (BMSCs) have been tentatively applied in the treatment of glucocorticoid-induced osteoporosis (GIOP) and systemic lupus erythematosus (SLE). However, the effects of BMSCs on osteoporosis within the context of glucocorticoid (GC) application in SLE remain unclear. Our aim was to explore the roles of BMSCs and different doses of GC interventions on osteoporosis in SLE murine models. MRL/MpJ-Faslpr mice were divided into eight groups with BMSC treatment and different dose of GC intervention. Three-dimensional imaging analysis and hematoxylin and eosin (H&E) staining were performed to observe morphological changes. The concentrations of osteoprotegerin (OPG) and receptor activator of nuclear factor κB ligand (RANKL) in serum were measured by enzyme-linked immunosorbent assay (ELISA). The subpopulation of B cells and T cells in bone marrows and spleens were analyzed by flow cytometry. Serum cytokines and chemokines were assessed using Luminex magnetic bead technology. BMSCs ameliorated osteoporosis in murine SLE models by enhancing bone mass, improving bone structure, and promoting bone formation through increased bone mineral content and optimization of trabecular morphology. BMSC and GC treatments reduced the number of B cells in bone marrows, but the effect was not significant in spleens. BMSCs significantly promoted the expression of IL-10 while reducing IL-18. Moreover, BMSCs exert immunomodulatory effects by reducing Th17 expression and rectifying the Th17/Treg imbalance. BMSCs effectively alleviate osteoporosis induced by SLE itself, as well as osteoporosis resulting from SLE combined with various doses of GC therapy. The therapeutic effects of BMSCs appear to be mediated by their influence on bone marrow B cells, T cell subsets, and associated cytokines. High-dose GC treatment exerts a potent anti-inflammatory effect but may hinder the immunotherapeutic potential of BMSCs. Our research may offer valuable guidance to clinicians regarding the use of BMSC treatment in SLE and provide insights into the judicious use of GCs in clinical practice.

Static Compaction on Coupled Precursors and Optimizing Molarity for Enhanced Strength and Durability of Geopolymer.

The static compaction technique emphasizes the reduced activator dosage required to develop geopolymers. Therefore, it is crucial to comprehend the optimal alkaline activator concentration for blending low-calcium precursor (fly ash) with high-calcium precursor (GGBS) to produce geopolymer blocks. This work was designed to optimize structural blocks' compressive strength and durability. In experimentation, fly ash (FA) and slag (GGBS) proportions were initially investigated under NaOH solution with varying molarity (8-12) and curing conditions to develop a load-bearing structural block. Subsequently, the durability of the optimized block was evaluated over 56 days through subjection to sulfate and acidic solutions, with efflorescence monitored over the same period. The results reveal that the structural block comprised of 100% FA exhibits the highest compressive strength and lowest bulk density. Conversely, the block incorporating 25% slag that underwent hot curing demonstrates a remarkable 305% strength increase compared to ambient curing. Considering the physico-mechanical performance, the 100% FA block was chosen for durability investigation. The findings indicate a substantial strength loss exceeding 40% after exposure to sulfate and acidic environments over 56 days, coupled with pronounced efflorescence. Catastrophic failure occurs in all cases due to significant strength deterioration. The FTIR spectrum revealed the shifting of the wavenumber to a higher value and verified the depolymerization and leaching of alumina under acidic exposure. However, the developed geopolymer blocks demonstrate superior sustainability and feasibility compared to conventional fired clay bricks and cement-based FA bricks. Despite slightly higher costs, these blocks exhibit greater strength than their counterparts after enduring severe exposures.

Fabrication of prostructured spanlastics gel for improving transdermal effect of dapagliflozin: In vitro characterization studies and in vivo antidiabetic activity

Dapagliflozin is a recently approved glucose-lowering agent for the management of type II diabetes mellitus. Low solubility and stability lead to its poor oral bioavailability. Prostructured spanlastic gel is very less hydrated preform of spanlastic vesicles. Therefore, the aim of this study was to explore the potential of prostructured spanlastic gel for enhancing both drug stability and transdermal delivery. The prostructured spanlastic gel formulations were fabricated by coacervation phase separation method, using Span 60 together with Tween 80 or Myrj 52 as an edge activator. Formulations were characterized for drug content, in vitro release and ex vivo skin permeability. Verification of vesicular form was assessed by hydration and the resultant formulations were characterized. Selected formulations were assessed for morphology, interaction of drug with other components, stability and antidiabetic activity. Drug content percentage of spanlastic gels was found to be in range 98.1 ± 1.9 to 94.2 ± 2.0 %. Significant (p < 0.05) increase in drug release rate was observed when edge activator concentration was greater than 30 %. Tween 80 containing formulations exhibited higher skin permeation than Myrj 52 containing ones at the same concentration of edge activator. Spanlastic vesicles were formed by hydration and had entrapment efficiency percentages ranging from 65.06 ± 0.87 % to 40.36 ± 0.95 %, mean vesicle sizes ranging from 136.1 nm to 56.52 nm and zeta potential values ranging from −29.7 mV to −6.94 mV. The morphologic examination verified formation of nanovesicular form. Thermal analysis and FT-IR confirmed encapsulation of drug inside spanlastic vesicles. Spanlastic gels showed higher stability and skin permeability when compared to vesicular form in hydroalcoholic gel. Spanlastic gels also showed prolonged hypoglycemic effect and blood glucose level reached below 135 ± 4.7 mg/dL after 24h, when compared to hydroalcoholic gel (273 ± 3 mg/dL) and oral suspension (271 ± 5 mg/dL). In conclusion, spanlastic gel could be a promising carrier for enhancing transdermal delivery of dapagliflozin, offering both sustained and enhanced antidiabetic activity.

Mix design strategy and optimization considering characteristic evaluation of geopolymer concrete

In this study, a unique strategy for mix design of geopolymer concrete (GPC) was suggested by integrating fly ash, silica fume, and GGBFS as precursors with varied alkali activator molarities in both ambient and oven curing environments. GPC's crystalline and microscopic qualities were assessed by X-ray diffraction and scanning electron microscopy tests; while its' mechanical properties were assessed using compressive strength test (CST). The experimental results showed a rising trend between the alkali activator (NaOH) concentration and the compressive strength of the GPC. GGBFS precursor based GPC had the highest compressive strength of 87.53 MPa at 14 molarity of NaOH after oven curing at 60°C. Furthermore, Artificial Neural Network (ANN) and Response Surface Method (RSM) were used to evaluate significant correlation and interaction between different parameters considered in mix design. By incorporating six input variables from the experimental test data, namely total precursor content used, secondary precursor content used, curing temperature, number of curing days, total aggregate content, and molarity of NaOH used, and compressive strength as output/response variable. The R-value for ANN found to be 0.99, while the R2 value for the RSM model was 0.98, indicating a satisfactory fit having a good interaction and optimization of GPC parameters. The optimize values of different independent parameters evaluated can obtain maximum CST value of 111.104 MPa.

Microscopic Mechanism and Reagent Activation of Waste Glass Powder for Solidifying Soil

Glass waste products represent a significant environmental concern, with an estimated 1.4 billion tons being landfilled globally and 200 million tons annually. This results in a significant use of land resources. Therefore, it would be highly advantageous to develop a new method for disposing of waste glass. Waste glass can be recycled and ground into waste glass powder (WGP) for use in solidified soil applications as a sustainable resource. This study is based on solidified soil research, wherein NaOH, Ca(OH)2, and Na2SO4 were incorporated as activators to enhance the reactivity of WGP. The optimal solidified soil group was determined based on unconfined compressive strength tests, which involved varying the activator concentrations and WGP content in combination with cement. X-ray diffraction (XRD) was used to study the composition of solidified soil samples. Microscopic pore characteristics were investigated using scanning electron microscopy (SEM), and the Image J software was employed to quantify the number and size of pores. Fourier-transform infrared spectroscopy (FTIR) was employed to examine the activation effect of waste glass powder. This study investigated the solidification mechanism and porosity changes. The results demonstrate that the addition of activated WGP to solidified soil enhances its strength, with a notable 12% increase in strength achieved using a 6% Ca(OH)2 solution. The use of 2% concentration of Na2SO4 and NaOH also shows an increase in strength of 7.6% and 8.6%, respectively, compared to the sample without WGP. The XRD and SEM analyses indicate that activated WGP enhances the content of hydrates, reduces porosity, and fosters the formation of a more densely packed solidified soil structure.

Investigation of the Effect of Blended Aggregate on the Strength and Drying Shrinkage Characteristics of Alkali-Activated Slag Mortar.

To reduce drying shrinkage of AASC mortar (AASM), mixed aggregate mixed with river sand (RS) and silica sand in three sizes was used to investigate the effect of the physical properties of mixed aggregate on shrinkage reduction. A mixture of river sand (0.2-0.8 mm), S1 (2.5-5.0 mm), S2 (1.6-2.5 mm), and S3 (1.21-160 mm) had river sand-silica sand mean diameter ratios (dr) of 7.68 (S1/RS), 3.75 (S2/RS), and 3.02 (S3/RS). The compressive strength and drying shrinkage characteristics of mixed aggregates according to fineness modulus, surface area, bulk density, and pore space were investigated. It had the highest bulk density and lowest porosity at a substitution ratio of 50%, but the highest strength was measured at a substitution ratio of 50% or less. High mechanical properties were shown when the fineness modulus of the mixed aggregate was in the range of 2.25-3.75 and the surface area was in the range of 2.25-4.25 m2/kg. As the substitution rate of silica sand increased, drying shrinkage decreased. In particular, the drying shrinkage of RS + S1 mixed aggregate mixed with S1 silica sand, which had the largest particle size, was the smallest. When silica sand or river sand was used alone, the drying shrinkage of the sample manufactured only with S1, which has the largest particle size of silica sand, was the smallest among all mixes. Compared to RS, at a 5% activator concentration, drying shrinkage was reduced by approximately 40% for S1, 27% for S2, and 19% for S3. At a 10% concentration, S1 showed a reduction effect of 39%, S2 by 28%, and S3 by 13%. As a result of this study, it was confirmed that the drying shrinkage of AASM could be reduced simply by controlling the physical properties of the aggregate mixed with two types of aggregate. This is believed to have a synergistic effect in reducing drying shrinkage when combined with various reduction methods published in previous studies on AASM shrinkage reduction. However, additional research is needed to analyze the correlation and influencing factors between the strength, pore structure, and drying shrinkage of AASM using mixed aggregate.