Temperature Ramp Research Articles

Measuring Temperature Dependence of Entropy Via Temperature Ramps Using Float Current Analysis

Float current analysis is a long-term self-discharge experiment keeping the voltage (float voltage) constant and measuring the resulting current with high precision. After a transient phase lasting around 30 days, the current reaches a steady state, named float current (10.3390/en16093889).The float current reflects the self-discharge of a cell, after effects due to the oversized anode to the cathode (anode overhang effect) are concluded (10.1016/j.est.2018.04.029). In some publications, the float currents show strong correlation with the capacity loss rate (10.1016/j.jpowsour.2017.03.136, 10.3390/batteries7020022).To characterize the cells, the float current is measured while keeping the cell voltage constant and varying the temperature in steps or as a ramp. Changing the temperature leads, due to the entropy effect, to an increase or decrease of the cell voltage depending on the sign and magnitude of the entropy coefficient (10.1149/1945-7111/ac3938). As the voltage in our experiment is kept constant, one observes an additional positive or negative current resulting from changes in temperature. In a stepwise temperature approach, a waiting time of about 1 day must be considered until currents resulting from the steps temperature transient have subsided. To understand more about entropy, we used this dependence as will be rolled out in the following.For our experiment we investigated three different cell types of the format 18650 with varying cathode active materials (LFP, NMC, NCA) with up to five different float voltages. The cells were kept at constant voltage using a precision Keysight test bench in a Binder temperature chamber. The temperature was varied from 5 to 50°C using temperature ramps with rates of 0.56 K/h to 2.25 K/h. The results are compared to a stepwise temperature increase with 5 K increments.During ramp phases, we measure the float currents superimposed on the positive or negative influence of the entropy. By calculating the average of a temperature upwards ramp and a temperature downwards ramp, the entropy share is eliminated and only the pure temperature-dependence of the float current is obtained. The shape of the float current over temperature is an exponential increase, indicating an Arrhenius relation. As a homogeneous temperature change must be established, faster temperature ramps reveal strongly distorted transient-parts at the begin and end of the ramp, while a lower velocity shows only a very small transient-part. Comparing the low temperature velocities with stepwise approach, we observed a high agreement of both strategies demonstrating the validation of the temperature ramp approach.To obtain the entropy share during temperature ramps, the float current results are subtracted from the respective upwards and downwards ramps. Contradicting the general opinion of entropy for batteries, we did not observe a constant entropy coefficient over temperature but an entropy coefficient increasing linearly with temperature for all cell types and cell voltages. This finding is of high importance for high-precision measurement of lithium-ion batteries. Figure 1

(Invited) Molecular Dynamics Simulation Insights into Plasma Treatment of Emerging Pollutants in Water

Eliminating organic pollutant molecules in water is a world challenge, that non-thermal plasmas at atmospheric pressure are aiming to address. Non thermal plasmas are used for treating contaminated water due to their ability to produce reactive oxygen and nitrogen species, the so-called RONS, which diffuse into water, react with pollutant molecules, and degrade them. Many experimental works have been designed, using different plasma sources [1, 2], but in all cases HO● radicals are acknowledged to play the main role in the degradation process.Classical and ab-initio reactive molecular dynamics (MD) simulations are relevant techniques for describing interactions of HO● with pollutant molecules in water, leading to the knowledge of degradation products, chemical pathways and rates [3]. Basically, MD simulations are solving the Newton equations of motion of a set of species, say atoms, molecules, clusters, etc. It is able to describe system size up to billion of species. It only needs the knowledge of interactions (force fields) between all species as well as initial conditions, preferably consistent with experiments. So it is suitable for addressing chemical reactivity. Classical reactive MD simulations are using available semi-empirical force fields, such as reaxFF, while ab-initio MD are required when no such force field is available. In this case, force fields are calculated quantum mechanically at relevant time steps of MD simulations.In fact, MD simulations act as a predictive "virtual microscope" provided the force fields are enough precise.In this work, MD simulations of the interaction of HO● radicals with molecules representative of various emerging pollutant families, as pesticide, antibiotics, PFAS in water, are studied. For mimicking HO● radicals release into water by non-thermal plasma, HO● radicals are periodically injected into a simulation box containing a pollutant molecule surrounded by several tens of water molecules. For obtaining statistically significant results, at least 10 simulations, with different initial conditions are run. The products that are formed will be compared with experiments, especially HPLC, GCMS and MS/MS measurements of plasma treated water.Another approach, consists in introducing a temperature ramp during the simulation for determining at which temperature products are appearing and in which order. Such an approach is revealing the reaction barriers up to full decomposition of the pollutant molecule. It can thus, by back-analysis, help to define which plasma or other advanced oxidation processing will be relevant [3]. Acknowledgements Part of this work has been supported by Conseil Régional Centre-Val de Loire with grant #2021-00144786 for projectPerturb’Eau. Monica Magureanu, Corina Bradu, Florin Bilea, Olivier Aubry, Dunpin Hong, Manoj Panyamthatta-Tayaroth are gratefully acknowledged for stimulating discussions and for providing experimental results.

Cold nociception as a measure of hyperalgesia during spontaneous heroin withdrawal in mice

Opioids are powerful analgesic drugs that are used clinically to treat pain. However, chronic opioid use causes compensatory neuroadaptations that result in greater pain sensitivity during withdrawal, known as opioid withdrawal-induced hyperalgesia (OWIH). Cold nociception tests are commonly used in humans, but preclinical studies often use mechanical and heat stimuli to measure OWIH. Thus, further characterization of cold nociception stimuli is needed in preclinical models. We assessed three cold nociception tests—thermal gradient ring (5–30 °C, 5–50 °C, 15–40 °C, and 25–50 °C), dynamic cold plate (4 °C to −1 °C at −1 °C/min, −1 °C to 4 °C at +1 °C/min), and stable cold plate (10 °C, 6 °C, and 2 °C)—to measure hyperalgesia in a mouse protocol of heroin dependence. On the thermal gradient ring, mice in the heroin withdrawal group preferred warmer temperatures, and the results depended on the ring's temperature range. On the dynamic cold plate, heroin withdrawal increased the number of nociceptive responses, with a temperature ramp from 4 °C to −1 °C yielding the largest response. On the stable cold plate, heroin withdrawal increased the number of nociceptive responses, and a plate temperature of 2 °C yielded the most significant increase in responses. Among the three tests, the stable cold plate elicited the most robust change in behavior between heroin-dependent and nondependent mice and had the highest throughput. To pharmacologically characterize the stable cold plate test, we used μ-opioid and non-opioid receptor-targeting drugs that have been previously shown to reverse OWIH in mechanical and heat nociception assays. The full μ-opioid receptor agonist methadone and μ-opioid receptor partial agonist buprenorphine decreased OWIH, whereas the preferential μ-opioid receptor antagonist naltrexone increased OWIH. Two N-methyl-d-aspartate receptor antagonists (ketamine, MK-801), a corticotropin-releasing factor 1 receptor antagonist (R121919), a β2-adrenergic receptor antagonist (butoxamine), an α2-adrenergic receptor agonist (lofexidine), and a 5-hydroxytryptamine-3 receptor antagonist (ondansetron) had no effect on OWIH. These data demonstrate that the stable cold plate at 2 °C yields a robust, reliable, and concise measure of OWIH that is sensitive to opioid agonists.

Inclusion of konjac glucomannan in pea protein hydrogels improved the rheological and in vitro release properties of the composite hydrogels

In this study, a composite hydrogel consisting of pea protein and konjac glucomannan (KG) was fabricated using three approaches, namely neutral, salt-set, and alkaline gelation. Hydrogels made from pea protein were brittle and weak. The addition of KG improved the elasticity and water holding capacity of the pea protein hydrogels. Concomitantly, a decrease in syneresis rate and swelling of the composite hydrogels was observed. The alkaline-set hydrogels exhibited the highest resilience to strain. Thixotropicity was found to be less pronounced for salt-set hydrogels. Sulphate had a greater positive effect on the structural recovery and negative effect on hysteresis area than chloride due to the greater salting-out effect of the sulphates. The addition of KG facilitated the formation of an interconnected structure with limited mobility of biopolymer chains. A sharp increase in G' and G" during the temperature ramp indicated the predominance of hydrophobic interactions towards the aggregation of biopolymers. The infrared spectra of the hydrogels revealed a change in secondary structure of proteins on addition of KG. A controlled in vitro release of riboflavin was observed in neutral and salt-set hydrogels. The alkaline-set hydrogels exhibited a prolonged gastric retention time, thereby establishing in vitro antacid activity in the gastric environment.

A cutting-edge approach based on UHPLC-MS to simultaneously investigate oxysterols and cholesterol precursors in biological samples: Validation in Huntington's disease mouse model

Brain is most cholesterol-rich organ in the body. Since cholesterol does not cross the blood brain barrier, its metabolism is provided in situ by astrocytes and neurons, and it is crucial for maintaining sterol levels and neuronal integrity and function. Recent studies have shown that the levels of cholesterol precursors and metabolites are lower in the brains of animal models of Huntington's disease (HD) while reduced levels of its catabolite are detected in the plasma of patients. In this study, we introduce a novel analytical method designed to fulfill the complex analytical requirements associated with cholesterol metabolites detection in neurodegenerative disorders. The method allows for the simultaneous quantification of a specific set of oxysterols along with cholesterol precursors in biological samples.The proposed method uses an Ultra-High-Performance Liquid Chromatography-Mass Spectrometry (UHPLC-MS) system operating in multiple reaction monitoring (MRM). Since sterols can be found in biological matrices in either free form or esterified to various fatty acids, a three-step extraction procedure was devised, consisting of alkaline hydrolysis, liquid-liquid extraction and final concentration omitting the need for a solid-phase extraction (SPE) step.The validated method achieved a detection limit of 10 ng/mL in plasma and 1 ng/mg in brain tissue, reaching a comparable sensitivity to previously published LC-MS and GC–MS methods. All target analytes were separated on a reverse-phase column employing a segmented gradient and a temperature ramp. This strategy enabled the elution and separation of all selected metabolites within a 30-minutes timeframe. This innovative approach was employed to quantify cholesterol metabolites in both plasma and brain samples from wild-type (WT) and R6/2 mice, a mouse model of HD. The results obtained from the sample analysis highlighted a significant reduction in desmosterol levels in the R6/2 brain at 12 weeks.In conclusion, the proposed method paves the way for further development of high-sensitive and reproducible protocols to comprehensively investigate simultaneous alterations in both cholesterol biosynthesis and catabolism in HD samples.

Rheological Properties and Kinetics of Gelation of Binary Polymers between Xanthan Gum and Locust Bean Gum.

The synergistic interaction and gelling kinetics between xanthan gum (XG) and locust bean gum (LBG) at different mass ratios (XG/LBG 9:1, 7:3, 5:5, 3:7, 1:9) were investigated using a rheometer. The results showed that the mixtures of XG and LBG induced gel formation, and the strongest gel structure was found for the mixture of XG/LBG 3:7 according to the yield stress, storage modulus (G'), and power law parameters. Temperature ramp studies indicated that heating destroyed the gels at 55~60 °C, while cooling induced the sol-gel transition at around 52 °C for all mixtures. Structure developing rate (SDR) curves showed that XG/LBG 3:7 exhibited the highest SDR during the cooling ramp among all the samples. Non-isothermal kinetic analysis demonstrated that the gelation process of XG/LBG mixtures during cooling included two steps: a high-temperature region (55~39 °C) needing higher activation energy (Ea, 111.97 to 199.20 kJ/mol for different mixtures) and a low-temperature region (39~20 °C) needing lower Ea (74.33 to 85.31 kJ/mol), which indicated higher energy barriers to overcome at the initial stage of gel formation. The lowest Ea of 74.33 kJ/mol was found for XG/LBG 3:7 in the low-temperature region. Scanning electron microscopy (SEM) showed that the gel of XG/LBG 3:7 presented the densest entanglements. These results indicated the strongest synergism interaction occurred in XG/LBG 3:7 to form gel network structures. This study will help promote the application of XG-LBG blends to design novel food structures.

Role of carbonization parameters on surface and microstructural and crystalline properties of mesoporous coconut shell char: Quantitative and structural study

The present work focuses on the synthesis of inactive mesoporous char using the carbonization method. The experiment was conducted at various conditions using a constant flow of nitrogen gas with variable temperature ramp and carbonization temperature i.e., 5 °C /min to 20 °C /min and 400 °C to 800 °C respectively. The product was identified by calculating its surface area, pore size, micro strain, interplanar spacing, packing density, full-width half maximum, crystallite size, lateral size, no of layers, dislocation density, crystallinity index, and morphological characterization. It was revealed that the best results in terms of surface area, pore size, micropore volume, and burn-off value of the char were observed at a carbonization temperature of 700 °C with a heating rate of 10 °C/min. The calculated values of surface area, pore size, micropore volume, and burn-off were found to be 211.816 m2/g, 2.288 nm, 0.121 cm3/g, and 20.2 % respectively.

Plasma catalysis: separating plasma and surface contributions for an Ar/N2/O2 atmospheric discharge interacting with a Pt catalyst

Atmospheric pressure non-equilibrium plasmas can form nitrogen oxide (NO x ) compounds directly from nitrogen and oxygen without a catalyst, and at lower catalyst temperatures than would be possible without plasma. In this work, the oxidation of plasma-produced NO from an Ar/N2/O2 non-equilibrium atmospheric-pressure plasma-jet (APPJ) over a platinum-on-alumina powder catalyst was investigated with in-situ infrared spectroscopy. Products downstream of the catalyst bed were analyzed along with catalyst surface species. The catalyst was exposed to plasma at both constant temperature and a cyclic temperature ramp in order to study long-lasting and transient surface changes. Primary incident reactive species to the catalyst were assessed to be NO and O3. Pt-Al2O3 at 350 °C increased oxidation of NO relative to Al2O3 or an empty chamber. The surface state of Pt-Al2O3 evolves during plasma-effluent exposure and requires upwards of 20 min exposure for stabilization compared to Al2O3. Once stable surface conditions are achieved, thermal cycling reveals a repeatable hysteresis pattern in downstream products. At low temperature, oxygen and NO x accumulate on the catalyst surface and react at elevated temperatures to form NO2. Increasing plasma power and O2:N2 ratio increases the hysteresis of the heating relative to the cooling curves in the pattern of NO2 formation. The limitation on NO oxidation at high temperatures was assessed to be Pt-O which is depleted as the catalyst is heated. Once stored species have been depleted, NO oxidation rates are determined by incoming reactants. Two overlapping NO oxidation patterns are identified, one determined by surface reactants formed at low temperature, and the other by reactants arriving at the surface at high temperature. The plasma is responsible for providing the reactants to the catalyst surface, while the catalyst enables reaction at high temperature or storage at low temperature for subsequent reaction.

In-situ investigation of the time-temperature dependent lattice and microstructure of Sn-Bi alloys

Alloys based on the Sn-Bi system are widely considered as the most promising candidates for low temperature solders (LTS) in the electronics industry due to their low liquidus temperature, non-toxicity and relatively low cost. However, implementation of LTS is complicated as they exhibit different characteristics from conventional Pb-free solders. While the solid solubility of alloying additions in Sn is typically <1 wt% in the current generation of Pb-free solders, the solubility of Bi in Sn ranges from less than 3 wt% at room temperature to 21 wt% at the eutectic temperature of 139 °C. In consequence, the microstructure and properties of Sn-Bi solders change significantly under varying temperature during normal service, affecting reliability. Since these changes are time and temperature dependent, interpreting results obtained using ex-situ methods requires assumptions about the stability of the alloy during transitions from the test environment to the observation environment, leading to an incomplete understanding of these changes. To address this, in-situ synchrotron powder X-ray diffraction (PXRD) and in-situ scanning electron microscopy (SEM) techniques were developed to investigate the time-temperature dependent lattice and microstructure of hypo-eutectic Sn-37wt%Bi and near-eutectic Sn-57wt%Bi solder alloys. This made possible for the first time the observation of changes during temperature fluctuations. The study revealed that lattice and microstructure are highly sensitive to factors like temperature ramp rate and isothermal holding time, not previously considered. The results will impact the design of electronic circuitry and process parameters during electronics assembly to enhance reliability and performance.

Valorization of Agricultural Polyolefin Plastic Waste in the Kingdom of Morocco through Thermal Pyrolysis: Influence of Thermal Parameters on Pyrolytic Oil Yields

This article focuses on exploring the recycling of agricultural plastic waste mixtures through the route of thermal cracking. In an experimental setting within a pilot-scale batch reactor, the impact of temperatures and heating rates on the yields obtained in the pyrolysis process have been meticulously examined. The temperatures of the pyrolysis process were varied between 360°C and 480°C, while the heating rates underwent changes, including 10, 15, and 30°C/min. The response parameters were the liquid, solid, and gas fractions. This research indicates that moderate temperatures and slower heating rates, resulting in extended reaction times, promote the generation of liquid fuel from pyrolysis. We achieved an optimal liquid fuel yield of 79% at 380°C, employing a temperature ramp of 10°C/min. Characterization of pyrolysis fuel resulting from the pyrolysis process revealed an extensive variety of hydrocarbons, requiring prior fractionation for optimal use in internal combustion engines. This step led to the separation into three distinct fractions: a light fraction (analogous to gasoline), accounting for 22.62% of the total weight, a middle fraction (similar to diesel), weighing 53.67% of the weight, and a heavy fraction (comparable to heavy diesel), totaling 23.71% of the weight. The light fraction presents an octane rating in line with conventional gasoline values, while the middle fraction meets the required cetane criteria for diesel.

Surfactant-free nano-emulsions from two lemongrass essential oils: Investigation of temperature ramp influence

Nano-emulsions are alternatives for incorporation of essential oils in food-products. Despite generation of surfactant-free nano-emulsions is well known (e.g., Ouzo effect) its stabilization is a critical issue. This study shows the behavior of surfactant-free nano-emulsions prepared with two lemongrass essential oils based in dynamic light scattering analysis through exposure to a linear ramp of temperature. The gas-chromatography coupled to mass-spectrometry analysis revealed that β-myrcene was found in the Cymbopogon citratus and absent in C. flexuosus. C. citratus nano-emulsion prepared with deionized water (CCNE-DW) presented initial lower size diameter (208.6 ± 1.9 nm) than C. flexuosus nano-emulsion (245.2 ± 3.1 nm) prepared with deionized water (CFNE-DW), probably due to the presence of β-myrcene capable of avoiding a rapid droplet growth before onset of dynamic light scattering measurements. In silico physicochemical properties suggest that β-myrcene could considered decisive for low size of C. citratus nano-emulsions, since reduction of its concentration may induce destabilization of C. citratus diluted nano-emulsions. Similar initial droplet size was observed for C. citratus nano-emulsion (221.0 ± 1.3 nm) prepared with infusion (CCNE-IN) and C. flexuosus nano-emulsion (215.7 ± 1.7 nm) prepared with infusion (CFNE-IN). The highest droplet reduction was observed for CFNE-DW (DR25–80ºC = 45.9 %; p<0.0001). Distinct phytochemical profile evidenced by 1H NMR, since C. citratus infusion shows an envelope of signals with more overlapped peaks between the chemical shifts at δH 3.5 – 4.0 ppm, may favored solubilization of droplet components by the infusion and responsible by droplet growth of diluted nano-emulsions, in addition to decrease of β-myrcene content. Our results show the feasibility of preparation of surfactant-free nano-emulsions from two lemongrass and contribute to better knowledge related to influence of chemical profiles in natural-product based nano-emulsions.

Structural engineering and truncation of α-amylase from the hyperthermophilic archaeon Methanocaldococcus jannaschii

Alpha amylases catalyse the hydrolysis of α-1, 4-glycosidic bonds in starch, yielding glucose, maltose, dextrin, and short oligosaccharides, vital to various industrial processes. Structural and functional insights on α-amylase from Methanocaldococcus jannaschii were computationally explored to evaluate a catalytic domain and its fusion with a small ubiquitin-like modifier (SUMO). The recombinant proteins' production, characterization, ligand binding studies, and structural analysis of the cloned amylase native full gene (MjAFG), catalytic domain (MjAD) and fusion enzymes (S-MjAD) were thoroughly analysed in this comparative study. The MjAD and S-MjAD showed 2-fold and 2.5-fold higher specific activities (μmol min−1 mg −1) than MjAFG at 95 °C at pH 6.0. Molecular modelling and MD simulation results showed that the removal of the extra loop (178 residues) at the C-terminal of the catalytic domain exposed the binding and catalytic residues near its active site, which was buried in the MjAFG enzyme. The temperature ramping and secondary structure analysis of MjAFG, MjAD and S-MjAD through CD spectrometry showed no notable alterations in the secondary structures but verified the correct folding of MjA variants. The chimeric fusion of amylases with thermostable α-glucosidases makes it a potential candidate for the starch degrading processes.

Fast Assimilation-Temperature Response: a FAsTeR method for measuring the temperature dependence of leaf-level photosynthesis.

We present the Fast Assimilation-Temperature Response (FAsTeR) method, a new method for measuring plant assimilation-temperature (AT) response that reduces measurement time and increases data density compared with conventional methods. The FAsTeR method subjects plant leaves to a linearly increasing temperature ramp while taking rapid, nonequilibrium measurements of gas exchange variables. Two postprocessing steps are employed to correct measured assimilation rates for nonequilibrium effects and sensor calibration drift. Results obtained with the new method are compared with those from two conventional stepwise methods. Our new method accurately reproduces results obtained from conventional methods, reduces measurement time by a factor of c. 3.3 (from c. 90 to 27 min), and increases data density by a factor of c. 55 (from c. 10 to c. 550 observations). Simulation results demonstrate that increased data density substantially improves confidence in parameter estimates and drastically reduces the influence of noise. By improving measurement speed and data density, the FAsTeR method enables users to ask fundamentally new kinds of ecological and physiological questions, expediting data collection in short-field campaigns, and improving the representativeness of data across species in the literature.

Testing the heat treatment dose for Agrilus planipennis (Coleoptera: Buprestidae) prepupae using the Humble water bath.

The lethal heat treatment dose (time and temperature) for the prepupal life stage of Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), emerald ash borer (EAB), was determined through an in vitro application using a carefully calibrated heat treatment apparatus. The lethal and sublethal effects of heat on A. planipennis prepupae were assessed through a ramped heat delivery application, simulating industrial kilns and conventional heat chamber operations, for treatments combining target temperatures of 54 °C, 55 °C, and 56 °C, and exposure durations of 0 min (i.e., kiln temperature ramp only), 15 min, or 30 min. Prepupal EAB larvae did not survive exposure to 56 °C for 15 min or longer, or to 55 °C for 30 min. Sublethal effects were observed for all other treatments. Sublethal effects included delayed development and failure to complete the pupal and adult life stages.

Rapid Determination of Five Residual Solvents in Ursodeoxycholic Acid Raw Materials

The chromatographic conditions were optimized using headspace gas chromatography, and a simple and rapid method was established for the simultaneous determination of five residual solvents in ursodeoxycholic acid raw materials. The corresponding quality standards were revised. The research results demonstrate that by utilizing a capillary column with a stationary phase consisting of 5% phenyl-95% dimethylpolysiloxane (HP-5, 30 m × 0.32 mm, film thickness 1.0 µm) and a flame ionization detector in conjunction with a headspace injection system and a programmed temperature ramping method, satisfactory analytical results can be achieved. The specific operating conditions are as follows: an initial column temperature of 45 °C, followed by a column temperature increase at a rate of 5 °C per minute up to 60 °C, then a further increase at a rate of 10 °C per minute up to 100 °C, and finally a rapid increase at a rate of 40 °C per minute up to 200 °C, where it is held for 10 min. Nitrogen is employed as the carrier gas at a flow rate of 1 mL/min with a split ratio of 14:1. The headspace vial temperature is maintained at 100 °C, with a sample equilibration time of 45 min. The concentration of methanol ranged from 0.06 mg/mL to 0.3 mg/mL, and the concentrations of acetone, tert-butanol, ethyl acetate, and triethylamine showed a good linear relationship with the peak area within the range of 0.1 mg/mL to 0.5 mg/mL (r = 0.999); The quantitation limits for methanol, acetone, tert-butanol, ethyl acetate, and triethylamine were 4.2, 0.9, 1.5, 1, and 0.1 μg/mL, respectively, with detection limits of 1.2, 0.25, 0.025, 0.3, and 0.025 μg/mL, respectively. The recovery rates of each solvent ranged from 92.9% to 106.0%, with RSD% (n = 9) less than 3.8%; the method exhibited good repeatability, with RSD% (n = 6) less than 2.5%. Furthermore, the robustness is good. The established method is simple, accurate, specific, and highly sensitive, and can be used for the simultaneous and rapid determination of five residual solvents in ursodeoxycholic acid raw materials.

Impact of Incorporating Free Calcium and Magnesium on the Heat Stability of a Dairy- and Soy-Protein-Containing Model Emulsion.

This study investigated the impact of calcium chloride (CaCl2) and magnesium chloride (MgCl2) at varying concentrations on a model milk formulation's physical and chemical properties after thermal treatment. The model milk was subjected to two-stage homogenization and pasteurization before being supplemented with different concentrations of CaCl2 or MgCl2. The findings revealed that elevating the concentration of either calcium or magnesium resulted in the milk emulsion having a higher viscosity and median particle size following heating. CaCl2 had a slightly stronger impact than MgCl2, particularly at higher concentrations. The milk samples also exhibited a reduction in the zeta potential as the ionic strength of the salt solution increased, with the CaCl2-fortified milk displaying a slightly lower negative surface charge than the MgCl2-fortified milk at the same dose. The model milk's viscosity was evaluated after adding various salt concentrations and a temperature ramp from 20 to 80 °C. Notably, the viscosity and particle size changes demonstrated a non-linear relationship with increasing mineral levels, where a significant increase was observed at or above 5.0 mM. An emulsion stability analysis also revealed that the de-stabilization pattern of the high salt concentration sample differed significantly from its low salt concentration counterparts. These findings could serve as a basis for the future development of fortified UHT milk with nutritionally beneficial calcium and magnesium in industrial applications.

EXTH-30. GOLD NANOSTARS OBVIATE LIMITATIONS TO LASER INTERSTITIAL THERMAL THERAPY (LITT) AND ENHANCE THE POST-LITT IMMUNE RESPONSE

Abstract Laser interstitial thermal therapy (LITT) is a minimally-invasive technique for the treatment of intracranial tumors that uses a stereotactically-guided laser and real-time magnetic resonance imaging (MRI) to monitor ablation progress. Previous applications of gold nanostars (GNS) in laser ablation of tumors have studied extracranial tumors only and utilized externally administered near infrared radiation that cannot penetrate the cranial compartment. Herein, we present a novel platform for employing GNS in intracranial tumors. We developed non-toxic GNS that exhibit maximum photothermal effects at the 1064 nm laser wavelength used in the FDA-approved clinical Neuroblate® LITT system. Monte Carlo simulations demonstrate that our GNS can accelerate and focus thermal energy distributions. Using ex vivo tumor phantom models, we found that GNS-infused phantoms demonstrate more rapid heating and improved spatial conformation of thermal energy, with neighboring material exposed to lower temperatures than controls. In our intracranial CT-2A glioma model, we quantified accumulation of radiolabeled GNS in tumor tissue via PET/CT. As further validation of tumor-selective GNS accumulation, we used two-photon luminescence to show that GNS selectively accumulate and are retained in intracranial tumors at 24 and 72 hours post-injection. We then utilized our in vivo heterotopic CT-2A model to assess the capacity of systemically-delivered GNS to augment laser ablation; we were able to achieve higher ablation temperatures and more efficient temperature ramping with LITT+GNS. Finally, we explored the potential of LITT+GNS to synergize with immunotherapy to further enhance the post-ablation immune response and found that combination therapy resulted in improved tumor control and immunologic memory that was protective against tumor rechallenge. These results support the ability of GNS to optimize LITT for the treatment of intracranial tumors by improving efficiency and safety, and illustrate the potential of this platform to synergize with immunotherapy.

Stage changes in the oxidizing properties of long-term water-soaked coal and analysis of key reactive groups

To elucidate the impact of prolonged water immersion on the evolution of key active functional groups during the low-temperature oxidation of coal, the programmed temperature ramping method, in-situ Fourier transform infrared spectroscopy (in-situ FTIR), microcalorimetry (C80) experiments, thermodynamic analysis, and gray and Pearson correlation analysis were performed. The analysis involved coal samples exposed to different immersion durations (3, 6, 9, and 12 months). The results reveal that long-term water immersion exerts a stage-wise influence on the oxidation characteristics of coal, with the critical time point being 6 months. Before this period, the gradual accumulation of active sites progressively enhances the oxidation characteristics. However, after 6 months, the generation of active sites is suppressed, resulting in a gradual weakening of the coal's oxidation behavior. Correlation analysis revealed that the correlation between free hydroxyl groups and gaseous products is strongest in coal immersed for 6 months (A6), with a correlation coefficient of 0.91. During the accelerated oxidation stage, the heat released from the soaked coal is significantly greater than that in other stages, which promotes the formation of C=O and –COOH functional groups and further reduces the apparent activation energy. According to the Coats–Redfern method, A6 exhibits the smallest apparent activation energy—only 30 % of the original value of coal. The correlation between free hydroxyl groups and apparent activation energy is strongest at this stage, with a correlation coefficient of 0.92. This indicates that free hydroxyl groups and the accelerated oxidation stage are, respectively, the key active functional groups and critical phases in the coal oxidation process.

The Potential of Mangifera indica L. Peel Extract to Be Revalued in Cosmetic Applications.

The constant growth of the cosmetic industry, together with the scientific evidence of the beneficial properties of phytochemicals, has generated great interest in the incorporation of bioactive extracts in cosmetic formulations. This study aims to evaluate the bioactive potential of a mango peel extract for its incorporation into cosmetic formulations. For this purpose, several assays were conducted: phytochemical characterization; total phenolic content (TPC) and antioxidant potential; free-radical scavenging capacity; and skin aging-related enzyme inhibition. In addition, the extract was incorporated into a gel formulation, and a preliminary stability study was conducted where the accelerated (temperature ramp, centrifugation, and heating/cooling cycles) and long-term (storage in light and dark for three months) stability of the mango peel formulations were evaluated. The characterization results showed the annotation of 71 compounds, gallotannins being the most representative group. In addition, the mango peel extract was shown to be effective against the •NO radical with an IC50 of 7.5 mg/L and against the hyaluronidase and xanthine oxidase enzymes with IC50 of 27 mg/L and 2 mg/L, respectively. The formulations incorporating the extract were stable during the stability study. The results demonstrate that mango peel extract can be a by-product to be revalorized as a promising cosmetic ingredient.

Numerical Computation of Williamson Hybrid Nanofluid Flow Over the Curved Surfaces With Effects of Thermal Radiation

Abstract The current investigation is based on Williamson's features of a hybrid nanofluid flow over a curved surface made mixture of silver (Ag) and titanium dioxide (TiO2) with engine oil. Under the presumption of a low magnetic Reynolds number, a constant homogenous magnetic field is applied. Consideration is given to the ramping temperature and the time-varying surface concentration. Thermal absorption and first-order consistent chemical reaction are also taken into account. To create a hybrid nanofluid, silver (Ag), and titanium nanoparticles are dispersed in a base fluid made of water and engine oil. Quasi-linearization technique and Finite difference scheme are employed on the nondimensional partial differential equations. All physical parameters of practical importance, such as velocity, temperature, and concentration profile are analyzed and provided in tables and graphs along with the impact of physical parameters. As the Williamson parameter (W) increases, the surface velocity of the steep plate decreases. Also, as the parameter temperature ratio of Nt and Rd increases, the forces opposing the flow field reduce the friction force, and the thermal field increases with temperature effects.