Retarding Effect Research Articles

Epoxide hydrolases JHEH1 and JHEH2 deficiency impairs glucose metabolism in Drosophila.

Epoxide hydrolases (EHs) play pivotal roles in detoxification, catabolism, and signaling by converting epoxides into diols and have been implicated in several diseases, such as cancers and diabetes. EH homologs in insects are designated as Juvenile hormone epoxide hydrolases (JHEHs) due to their catalytic activity toward Juvenile hormone (JH). However, the biological function of JHEHs has been controversial in the fruit fly Drosophila melanogaster. In this study, we generated and characterized flies deficient in Jheh1 and Jheh2 genes. We found that Jheh1/2 deficiency caused a developmental delay and enhanced the growth retardation effects of caffeine and paraquat. Additionally, we observed that the deficiency reduced tolerance to cold stress. These results indicate that JHEHs are required for growth promotion and stress tolerance. Metabolomic and transcriptomic analyses revealed that Jheh1/2 deficiency impaired glucose metabolism and downregulated genes involved in glycolysis and the TCA cycle. Furthermore, transgenic overexpression of Jheh1 increased glycolytic metabolites and restored the Jheh1/2 deficiency-associated phenotype. These results demonstrate that JHEHs play a crucial role in glucose metabolism in Drosophila, providing a valuable model to study the mechanisms underlying the function of EHs in energy metabolism.

Impact of phosphonate and phosphoramidate in Si/P/triazine hybrid flame retardants on cotton flammability

Phosphorus and nitrogen-containing flame retardants are well-known for their high efficacy when used in combination, either as separate compounds or within the same molecule. However, a detailed examination of the chemical bonding of phosphorus is needed to understand the flame behavior. To this end, two different scenarios were examined and compared with a phosphorus-free benchmark. Both scenarios contain a triazine ring and a silane-based precursor. The first scenario involves a direct bond between phosphorus and triazine (phosphonate), while the second involves a bridging of phosphorus and triazine via nitrogen (phosphoramidate). This allowed to investigate the structural effect of phosphoramidate and phosphonate of triazine derivatives on the thermal and flame retardant behavior. The flame-retardant performance and mechanism of the treated samples were investigated by means of the vertical flame test (DIN EN ISO 15025), thermogravimetric analysis and microscale combustion calorimetry, amongst others. Our research shows that triazine-based phosphonate has a better flame retarding effect on cotton than phosphoramidate at the same phosphorus concentration. Self-extinguishing characteristics was observed at a low add-on value of 0.23 mmol/g for phosphonate-based flame retardant, while a higher add-one value of 0.24 mmol/g was required in the case of phosphoramidate. The comprehensive analysis demonstrated that both flame retardants undergo mechanisms in both the gas phase and condensed phase by releasing incombustible gases and promoting the carbonization of cotton fabrics.

Effectiveness of fire protection of wood with an organic-mineral coating with the addition of aluminum hydroxide

Abstract. Today, there are two methods of fire protection for wood. The first is impregnation with flame retardants, most often based on inorganic salts. When wood is moistened, fire retardants dissolve in a humid environment and gradually wash out to the surface, and then the fire retardant effect decreases over time. Acid-based products do not have a significant leaching problem due to changes in wood moisture, but penetrating deep into the wood structure and interacting with the cellulose, they reduce strength parameters. Therefore, it is not safe to use this product for critical load-bearing structures. The second method is to apply an organic or inorganic binder coating to the wood surface. Organic binder-based products have increased smoke generation and toxic substances, so their use is dangerous. Therefore, coatings capable of forming a heat-insulating layer on the surface of a building structure, which significantly reduces the processes of heat transfer to the material, have recently become widespread. As a result of the studies, it was found that the introduction of aluminium hydroxide into the composition of the organo-mineral coating in the amount of 2...8% reduces the swelling coefficient from 30 to 18 to a certain extent. However, for a coating containing 4%, an increase in the efficiency of fire protection of wood was found, namely a decrease in the loss of sample mass and flue gas temperature due to the formation of heat-resistant compounds on the surface of the fire protection layer when aluminium hydroxide interacts with ammonium polyphosphate. The use of aluminium hydroxide in the fireproofing composition provides the required level of protection of wood from thermal effects at the required amount of 4%, which leads to a reduction in cost and an increase in the efficiency of the coating. In further studies, it is planned to investigate other types of fillers, their properties and impact on the fire protection efficiency of wood in fireproof organic-mineral coatings.

Effects of plant growth retardant and gibberellin on flower coloration patterns of Petunia × hybrida

Effects of plant growth retardant and gibberellin on flower coloration patterns of Petunia × hybrida

Study on the properties of synergistic flame retardant PA66/aluminium hypophosphite composites

The halogen-free flame retardant (HFFR) polyamide-66 (PA66) composites filled with aluminium hypophosphite (AHP) had been prepared by melt compounding method using a twin-screw extruder. The thermal degradation behaviour, flame retardancy, microscopic morphology of carbon slag, smoke release and mechanical properties of HFFR PA66 composites had been investigated by thermogravimetric analysis (TGA), cone calorimeter, UL-94 vertical test, limiting oxygen index (LOI), scanning electron microscopy (SEM), NBS smoke density chamber, ultimate tensile and IZOD notched impact testing. The research results indicated that the flame retardancy and char-forming of PA66 composites had been dramatically improved, especially for sample A-7 with the addition of synergistic agent zinc borate (ZB). Due to the addition of ZB, a very obvious expansion phenomenon was observed during the combustion process, and the combustion residue presented a honeycomb-like microstructure with many dense pores. The addition of ZB not only had a significant synergistic flame retardant effect with AHP on PA66 composites, but also greatly reduced smoke release during combustion, which was crucial for reducing fire hazards. Mechanical testing showed that the addition of synergistic agents ZB and organic montmorillonite (OMMT) can reduce the negative effects of AHP on tensile strength, elongation at break, and impact strength, which was beneficial for practical engineering applications.

Sustainable Emulsified Acid Treatments for Enhanced Oil Recovery in Injection Wells: A Case Study in the Qusahwira Field

Emulsified acid treatments present an innovative and environmentally sustainable alternative to conventional hydrochloric acid (HCl) methods in enhancing oil recovery. This study investigates the application of a stable emulsified acid formulation in matrix acidizing operations to improve injectivity in four wells within the Qusahwira Field. Compared to traditional 15% HCl treatments, the emulsified acid demonstrates deeper acid penetration and retardation effect leading to enhanced injection rate. By delivering deep worm holing effects against calcium carbonate formation, this dual-phase system enhances injectivity by 14 times while minimizing the environmental and material impacts associated with spent acid volumes. The methodology integrates advanced neural network modeling to predict stimulation outcomes based on 15 operational and reservoir factors. This model reduces the trial-and-error approach, cutting operational costs and time for carbonate reservoir. Field trials reveal significant improvements in injection pressure and a marked reduction in circulation pressure during stimulation, underscoring the treatment’s efficiency. Developed in a Superior Abu Dhabi laboratory, the emulsified acid achieves high-temperature stability (200 °F) and deep acid penetration, further reducing the ecological footprint of acid stimulation by enhancing operational precision and reducing chemical use. This paper highlights a sustainable approach to optimizing reservoir productivity, aligning with global efforts to minimize environmental impacts in oil recovery processes.

Evaluation of retardation effect for the migration of cesium under unsaturated conditions

Evaluation of retardation effect for the migration of cesium under unsaturated conditions

Enzymatic hydrolysis of palm cellulose to yield nanocrystals with potential roles in lipid and cholesterol digestion and absorption

Abstract Limited research has been conducted to understand the influence of cellulose nanocrystals (CNCs) on lipid and cholesterol digestion and absorption. This study aimed to explore and understand the ability of CNCs to modulate these processes. CNCs were obtained from palm-pressed fiber (PPF) via a green enzymatic hydrolysis method, a more environmentally friendly alternative to the traditional, acid hydrolysis. Enzymatic hydrolysis was performed using the endo-β-D-glucanase derived from Aspergillus sp. The effect of the enzyme concentration (250–1000 U/g) and reaction times (12–72 h) on CNC particle size, morphology, yield and suspension stability were studied. Enzymatic hydrolysis at a concentration 500 U/g and 72 h of incubation successfully produced needle-shaped, shortened, and non-entangled CNCs with an average diameter of 22.76 ± 5.52 nm, length of 342.55 ± 148.69 nm, an aspect ratio of ~ 15, and a crystallinity of 61.45%. Interestingly, the water (22.28 ± 0.85 g/g) and oil (15.08 ± 0.62 g/g) holding capacities of CNCs were four times higher than raw PPF (5.31 ± 0.53 g/g; 3.52 ± 0.32 g/g). The results showed increasing CNCs concentrations decreased lipase activity mobilization, increased cholesterol adsorption capability and retarded bile acid diffusion. 1% of CNCs alone inhibited 54.93% of lipase activity. 1 g of CNCs adsorbed 54.19 ± 10.70 mg of cholesterol and demonstrated a greater bile acid retardation effect than microcrystal cellulose (CNCs: 39.3 ± 10.10%: MCC: 27.05 ± 6.72%). The entrapment of lipase and bile acid by CNCs could affect lipid and cholesterol digestion, potentially benefiting digestion health applications. Furthermore, the presence of CNCs could potentially alleviate hypercholesteremia by adsorbing cholesterol and reducing bile acid diffusion. The results revealed the effectiveness of CNCs extraction from PPF through enzymatic hydrolysis and suggest that CNCs may have health benefits as a functional ingredient for developing of fat- and cholesterol-rich foods with health-promoting properties.

Synthesis of multi‐element flame retardant hydrazides and its modification to epoxy resin

AbstractWhen flame retardants are added to epoxy resins (EP) to enhance their flame retardancy, it often results in a negative impact on the mechanical properties of itself. In order to solve this problem, a new reactive flame retardant multi‐element hydrazides (BSD) is synthesized by using benzenesulfonohydrazide and diphenylphosphinic chloride as raw materials, it can play a flame retardant effect through the synergistic effect of P\N\S multi‐elements, and at the same time, a large number of secondary amine groups in the structure of BSD can produce strong hydrogen bonding interactions with the hydroxyl groups of the molecular chain of EP. The experimental results proved that the incorporation of only 3 wt% of BSD enabled EP to achieve a UL‐94 V‐0 rating. Furthermore, when the amount of BSD is increased to 5 wt%, the values for peak heat release rate (PHRR) and total heat release showed a reduction of 26% and 20.8%, ultimately maximizing the limiting oxygen index to 34.9%, showing exceptional efficiency. In the meantime, it showed a 37.3% increase in flexural strength and a 21.4% increase in tensile strength, and the transparency of the modified epoxy resin was still maintained at this time. In summary, introducing BSD into EP obtains a highly efficient reinforced flame retardant epoxy resin (FREP).Highlights A P/N/S‐containing hydrazide to improve the flame retardant of EP. When the P content is 0.25 wt%, the FREP reaches UL‐94 V‐0 grade. Tensile and flexural strength increased by up to 21.4% and 37.3%. With the addition of BSD, the FREP still show high transparency.

Variable effects of a fire-retardant gradient on seasonal wetland communities.

Wildfires have become larger and more severe in recent decades. Fire retardant is one of the most common wildfire response tools to protect against loss of life and property. Previous studies have documented various effects of fire retardant, which commonly contains chemicals used in fertilizers, on plant and invertebrate community composition. This mesocosm study investigated the effects of fire retardant on water quality and plant and invertebrate communities in California vernal pools. This study found that fire retardant caused water quality conditions to shift from oligotrophic to eutrophic with strong correlations between fire retardant and phosphates, nitrates, conductivity, and chlorophyll-a. Algal cover increased with added fire-retardant concentration. Shifts in invertebrate and plant communities occurred even at relatively low fire-retardant concentrations. Abundance of passive dispersers (crustaceans) peaked at medium concentrations of fire retardant, but time also influenced the relationship between fire retardant and passive invertebrate abundance. Active disperser (insects) abundance increased with increasing fire-retardant concentration and invertebrate richness peaked at medium concentrations. This study informs land managers, government agencies, and the public of the side-effects of fire-retardant use on populations, communities, and water quality of freshwater ecosystems.

Mechanism Study on the Effect of Retarder on Polyurethane Setting Time Based on Molecular Simulation

Mechanism Study on the Effect of Retarder on Polyurethane Setting Time Based on Molecular Simulation

A Smart Food Freshness Indicator Film for Shrimp and Pork with the Higher Visuality, Barrier, Flame Retardancy, and Antibacterial Effects

A Smart Food Freshness Indicator Film for Shrimp and Pork with the Higher Visuality, Barrier, Flame Retardancy, and Antibacterial Effects

The effect of organic admixtures on the early nucleation of calcium silicate hydrate: non-classical nucleation mechanism

The effect of organic retarders on the nucleation mechanism of calcium silicate hydrate (C-S-H) is still under debate. In this study, the effects of organic admixtures Dextrin, citric acid (CA), and citric acid modified chitosan (CAMC) on the early formation of C-S-H were investigated. The results indicated that the C-S-H formation followed a non-classical nucleation mechanism: amorphous silicate droplets formed first and then crystallized into thin foil-like tobermorite-type C-S-H. The –COOH group affected the Ca/Si ratio of the C-S-H product and reduced the particle reaction driving force, which is the main reason for the transition of the synthesis process from endothermic to exothermic. The formation of hydration products was not inhibited by nucleation disruption, Ca complex precipitation, or encapsulation of silicate spheres; instead, it was by the reduction of free Ca2+ normally involved in the formation process.

Nonclassical Optical Response of Particle Plasmons With Quantum‐Informed Local Optics

AbstractAs the dimensions of plasmonic structures or the field confinement length approach the mean free path of electrons, mesoscopic optical response effects, including nonlocality, electron spill‐in or spill‐out, and Landau damping, are expected to become observable. In this work, a quantum‐informed local analogue model (QILAM) that maps these nonclassical optical responses onto a local dielectric film is presented. The primary advantage of this model lies in its compatibility with the highly efficient boundary element method (BEM), which includes retardation effects with relatively large particle sizes. Furthermore, the approach offers a unified framework that connects two important semiclassical theories: the generalized nonlocal optical response (GNOR) theory and the Feibelman d‐parameters formalism. It is envisioned that QILAM can evolve into a multiscale electrodynamic tool for exploring nonclassical optical responses in diverse plasmonic structures in the future. This can be achieved by directly translating mesoscopic effects into observable phenomena, such as plasmon resonance energy shifts and linewidth broadening in the scattering spectrum.

High-Throughput Zebrafish Screening Reveals Cardiotoxic Effects of Organophosphate Flame Retardants.

The toxicity of organophosphorus flame retardants (OPFRs) remains poorly understood, despite their widespread environmental presence and potential risks to human and ecological health. This study aimed to characterize the cardiovascular developmental toxicity of OPFRs using a high-throughput zebrafish screening model. Over thirty representative OPFRs, classified into three major groups-alkyl, aryl, and halogenated-were evaluated. Our results demonstrated that aryl-substituted OPFRs, such as triphenyl phosphate (TPHP) and tris(3,5-dimethylphenyl) phosphate (TXP), exhibit significantly more potent cardiotoxic effects compared to alkyl- and halogenated-substituted OPFRs. Specifically, heart rate of zebrafish increased by 8.3% and 11.9%, and cardiac output increased by 30.8% and 39.9% for TPHP and TXP, respectively, at a concentration of 160 μg/L. Additionally, exposure to aryl-substituted compounds like TPHP resulted in notable developmental abnormalities, including pericardial edema and skeletal bending. Molecular descriptor analysis further identified a series of essential structural features, including estrogen receptor agonist activity and bioconversion rates, which are closely linked to the observed cardiotoxicity, thus providing a mechanistic explanation for these effects. These findings offer valuable insights into the molecular mechanisms underlying OPFRs toxicity, which could inform the development of safer flame retardant alternatives. Moreover, addressing the research gaps in translating zebrafish findings to other species and real-world ecological scenarios should be further concerned.

The in-vitro digestibility of instant noodles: Interplay of texture, microstructure and starch structure.

Instant noodles are a worldwide food staple. However, the correlation between its production methods and nutritional characteristics remains unclear. This study aims to elucidate the effects of hydrothermal (steaming and boiling) and cooling techniques on instant noodles in-vitro digestibility. Texture of rehydrated noodles, microstructure observed by SEM and starch molecular structure measuring techniques were used to identify the underlying mechanisms. Our results demonstrate that boiling results in incomplete gelatinization of internal starch, leading to a microstructure with numerous pores and channels due to irregular starch distribution. This microstructure facilitates α-amylase diffusion and subsequent attachment to the substrate, yielding a higher starch digestion rate coefficient for boiled noodles (Nboiled) within the first 120min (K1, 5.7min-1) compared to steamed noodles (Nsteamed, K1, 4.4min-1). However, from 120 to 360min, Nboiled exhibited a lower rate coefficient (K2, 4.5min-1) due to the retarding effect of incompletely melted starch structure and greater texture rigidity, contrasting with Nsteamed (K2, 6.1min-1). Moreover, noodles subjected to boiling and subsequent cooling exhibited the lowest starch degradation by α-amylase throughout hydrolysis. This is attributed to their increased hardness, denser microstructure, and presence of ungelatinized or recrystallized starch. Therefore, the study concludes that cooking and cooling processes significantly influence noodle texture, microstructure, and starch structure, collectively impacting the nutritional value of instant noodles. Our findings provide valuable insights for the development of nutritionally enhanced instant noodles.

Alkali-Induced transformation of salt lake magnesium slag into novel magnesium hydroxide-coated aluminum hypophosphite nanomaterials and their synergistic flame retardant effects

Alkali-Induced transformation of salt lake magnesium slag into novel magnesium hydroxide-coated aluminum hypophosphite nanomaterials and their synergistic flame retardant effects

Effects of triiodobenzoic acid on growth, yield and photosynthetic pigmentcontent of chickpea (cicer arietinum l.)

An experiment was conducted to evaluate the effect of seed soaking treatment of TIBA (10, 15, 20, 25, 30 and 35 ppm) on growth, yield and photosynthetic pigment content of chickpea var. BARI Chhola-6. Results revealed that TIBA had mostly retarding effects on plant height of BARI Chhola-6 with both significant and non-significant variations. The Number of branches and leaves per plant was positively influenced following all concentrations of TIBA where, seed treated with 35 ppm TIBA produced the highest values. Results revealed that TIBA treatments had inducing effects on flower initiation and completion. Application of TIBA induced the yield and yield attributes of BARI Chhola-6 where, 30 ppm TIBA produced the highest number of pods (72.25), maximum number of seeds per plant (112.13), 100-seed weight (23.84g) and yield per plant (15.92g). TIBA had pronounced effects on the photosynthetic pigment content of BARI Chhola-6 although 35 ppm TIBA resulted maximum values but not significantly different from 30 ppm and some other treatments. Of seven treatmnts, 30 ppm TIBA produced better stimulations. Bangladesh J. Bot. 53(4): 949-955, 2024 (December)

Effect of time-dependent sinusoidal electric field on the onset of electroconvection in a viscoelastic fluid layer

Time-periodic electric field modulation of a viscoelastic dielectric fluid layer heated from below and cooled from above is examined using an Oldroyd-B type liquid. On the basis of small amplitudes of modulation, the regular perturbation method can be used to calculate the threshold for correction of the critical Rayleigh number. The dielectric constant is assumed to be a linear function of temperature. We show that electric field modulation frequency, electrical, Prandtl number, and viscoelastic parameters are related to the shift in the critical Rayleigh number and the possibility of subcritical convection for low-frequency modulation of the electric field. Rayleigh number, wavenumber, and frequency stability are determined based on free-free isothermal boundary conditions. The dielectrophoretic force is only destabilizing when an electrical field is modulated at a low frequency because it is associated with an unmodulated layer of dielectric fluid. As a result of the stress relaxation parameter in a sinusoidal electric field, the system is destabilized at low frequencies and stabilized at moderate and high frequencies. The effect of strain retardation on mechanical anisotropy is completely opposite. The stability characteristics are illustrated through graphs showing the numerical values of parameters.

Effect of annealing twins on grain boundary migration in high-purity copper

The effect of grain boundary retardation by annealing twins in pure copper has been experimentally and theoretically investigated. A model that describes the influence of annealing twins on the migration of grain boundaries in pure metals has been proposed. The retarding force from the twins has been demonstrated to be analogous to the Zener retarding force created by incoherent fine particles. An equation has been derived to calculate the retarding force induced by annealing twins. The force has been demonstrated to be inversely proportional to the size of the twins and directly proportional to their volume fraction. The simulation results have been compared with the experimental results. A satisfactory correlation between the theoretical and experimental results has been achieved.