Isothermal Calorimeter Research Articles

Effect of carrageenan on stability and 3D printing performance of high internal phase pickering emulsion stabilized by soy protein isolate aggregates under neutral condition

High internal phase Pickering emulsion (HIPPE) stabilized by heat induced soy protein isolate aggregates (HSPI) alone had limited stability and poor 3D printing performance. While there is few research about HIPPE stabilized by HSPI and polysaccrides at neutral pH condition, where HSPI and ĸ-carrageenan (CG) were combined to fabricate HIPPE in this research. It was found that the incorporation of CG significantly decreased the droplet size and improved the storage stability of the resulting HIPPE. Moreover, the presence of CG improved the freeze-thaw stability of HIPPE after one freeze-thaw cycle. In addition, the addition of CG significantly improved the structural integrity of the 3D printed HIPPE and enhanced the printing precision. This was because the presence of CG decreased the interfacial tension, increased the zeta potential and viscosity of HSPI-CG, thus promoting the adsorption of particles to the oil-water interface more effectively. Moreover, the presence of CG significantly enhanced the viscoelasticity of the resulting HIPPE. These results can be further attributed to the strong hydrogen bonding and hydrophobic interaction between HSPI and CG at neutral pH condition, which can be confirmed from results of Fourier-transform infrared spectroscopy and Isothermal titration calorimeter. So the incorporation of CG endowed HIPPE with more excellent properties at a lower solid particle concentration.

Influence of Wastes and Synthesis Conditions on the Compressive Strength, Setting Time and Gels of Waste-Based Geopolymers.

In civil engineering, both rapid setting and delayed setting are needed for various application scenarios. In order to regulate the setting time of concrete, the iron ore tailings-blast furnace slag (IOT-BFS)-based geopolymers were synthesized with a broad range of setting time and a high compressive strength in this study. The factors of iron ore tailings content, alkali content, liquid-solid ratio, and modulus of alkali activator on setting time of the geopolymers were analyzed. The setting times of geopolymers are tested by a manual Vicat apparatus, and their microstructure is characterized by scanning electron microscopy (SEM), as well as that the hydration heat flow is characterized by an isothermal heat conduction calorimeter (TAM Air). It is found that setting time of the geopolymers was mostly affected by the modulus of alkaline activators due to the reasons that changes in modulus lead to the accelerated hydration reaction, formation of low-polymeric silicates, generation of gels, and encapsulation of precursor particles caused by high viscosity. Adjusting the modulus of the alkaline activator to 0.8 can control the initial setting time of the geopolymers to around 3 min. When the modulus ranges from 1-1.8, the initial setting time fell in the range of 15-45 min. For an alkaline activator modulus of 2, the initial setting time increased to 108 min. This study gives a clue for the preparation of geopolymers with adjustable setting times for multi-scenario applications in construction materials.

Electrochemical aptasensor for 2-amino-2-thiazoline-4-carboxylic acid (ATCA), a metabolite for cyanide poisoning

An alternative biomarker for assessing the cyanide levels in postmortem materials is crucial for investigating acute cyanide intoxication. Herein, an aptamer–ligand biorecognition system with high specificity was developed to detect acute cyanide poisoning via its secondary metabolite, 2-amino-2-thiazoline-4-carboxylic acid (ATCA). Potential aptamers were screened from a random library of 66-base single-stranded DNA using GO-SELEX, with individual aptamers being identified through single-stranded DNA sequencing. Molecular docking was employed to predict the affinity of these aptamers toward ATCA and selected counter-targets; these predictions were confirmed using thermodynamic analysis with an isothermal titration calorimeter. Owing to its label-free biomolecular binding interactions, Apt46 exhibited the highest affinity against ATCA and notable selectivity against structurally similar counter-targets. Thus, an amino-tagged Apt46 binding aptamer was attached to a carbon electrode modified with EDC–NHS-activated graphene oxide. The binding of Apt46 to ATCA was quantified by measuring current changes using differential pulse voltammetry. The aptasensor achieved a detection limit of 0.05 µg/mL and demonstrated suitability for detecting ATCA across various biological matrices, with the high recovery percentages ranging from 92.29 to 114.22%. Overall, the proposed ATCA aptasensor is promising for identifying ATCA metabolites in cases of acute cyanide exposure.

Heat of hydration in ultralight cementitious foams incorporating metakaolin and microencapsulated phase change material

The paper presents the results of a study on the hydration heat of ultralight cementitious foams envisaged as insulation materials for building envelopes. The examined porous foam-cement material was additionally enhanced by embedded microencapsulated phase change material (PCM) to improve the desired thermal properties of the material. The heat emission and heat flow were measured at 20 °C and 30 °C for 168 h using the isothermal calorimeter. The experimental study comprised composites with dry densities of 240 kg m−3 and 480 kg m−3, two concentrations of protein-based foaming agent (2% and 4%) and two dosages of the embedded PCM material (10% and 20%). The reference composite without PCM was also tested. The effect of the necessary admixtures used to achieve the stability of ultralight cementitious foams was also examined. The results showed that hydration in ultralight foam-cement composites is retarded, and the values of heat released are lower than those of the paste used to produce the composites. In this regard, the main factors contributing to the lower heat released and its lower rate are the excess water from the foam, the dosage of the foaming agent and the admixtures introduced to achieve the stability of the ultralight composite. The stabiliser was found to be the most retarding admixture. Considering PCM, which was added at 10% and 20% of the paste volume, a rather low influence on the course of the hydration process was observed due to the overall composition of ultralight cementitious foams specially modified for each assumed content of PCM.

Design, calibration and testing of a novel isothermal calorespirometer prototype

A prototype of an innovative isothermal calorespirometer was developed to measure simultaneously heat production rate (calorimetry) and CO2 evolution rate (respirometry) in real-time in a static batch vessel system. The relationship between these two variables forms the calorespirometric ratio, which serves as a crucial indicator for metabolic processes and allows for the differentiation of various metabolic pathways in simple (pure culture) and complex (e.g. soil) biological systems. The heat production rate is gauged by a thermoelectric generator situated at the bottom of the measuring channel (calorimetric unit), while the CO2 evolution rate is monitored through a conductometric cell fixed on the lid of the channel (respirometric unit). The prototype is designed with a twin configuration, featuring both sample and reference channels. The spatial separation of the calorimetric and respirometric measuring units ensures the simultaneous measurement of the two rates from a single sample without the occurrence of crosstalk effects between the signals.The electrical calibration of the calorimetric unit reveals heat losses (approx. 30 %) and response times (approx. 6 min) that are comparable to those of established isothermal calorimeters. In parallel, growth experiments conducted with baker`s yeast demonstrate the applicability of the calorespirometer prototype to biological systems.

Regulating sulfur migration and transformation in low water-binder ratio cementitious system incorporating phosphogypsum aggregate: Environmentally friendly clean materials

The paper aims to clarify the regulation mechanism of sulfur migration and transformation in a low water-binder ratio system incorporating phosphogypsum aggregate (LWC-PG). Firstly, the combination of S-containing adhesive material and phosphate gypsum aggregate can reduce the migration of sulfate ions (SO42−) in the phosphate gypsum aggregate. The reaction mechanism and macro and micro properties of LWC-PG are characterized by universal testing machine, low field nuclear magnetic field, isothermal calorimeter, XRD diffractometer, scanning electron microscope and nano-indentation. The results show that the calcium sulfoaluminate cementitious system (CSA) is compatible with PG. The results show that CSA is compatible with PG, and the 28d strength of 80 % phosphogypsum is 83.4 MPa, which can maintain the required strength for high-performance concrete. Secondly, the sulfides in PG react with C4A6S in CSA, resulting in the formation of ettringite that coats the surface of the C–S–H gel, thereby retarding the hydration rate of the slurry. However, due to the presence of phosphate gypsum aggregate, the reaction continues, enhancing the hydration of sulfate cement. Moreover, the interfacial transition zone between the PG and matrix exhibits a strong bond and shows no significant signs of deterioration. Lastly, when using 80 % phosphogypsum aggregate instead of natural sand and gravel to produce 100 m3 of concrete, 42 t of phosphogypsum aggregate can be used, which reduces the consumption of natural sand and gravel by 61.4 t, decreases energy consumption by 3070 MJ, reduces CO2 emissions by 178.06 kg, SO2 emissions by 0.37 kg, NOX emissions by 0.25 kg, and dust emissions by 0.087 kg. Life cycle evaluation demonstrates that the production of LWC-PG is associated with low carbon emissions and environmental friendliness, which significantly reduces environmental burden. This is of significant research importance for solid waste management and energy-saving and carbon reduction efforts.

STUDY OF THE INFLUENCE OF MODIFIERS ON THE HYDRATION OF CEMENT BY THE METHOD OF ISOTHERMAL CALORIMETRY

The effect of modifiers on the hydration of cements was studied by isothermal calorimetry. Thermochemical experiments were carried out using a TAM III isothermal calorimeter (TA Instruments). For the TAM III calorimeter, a method was developed for conducting experiments on monitoring the thermal activity of solid-phase samples with the possibility of repeated use of steel ampoules with a volume of 20 ml. The processes of hydration of Portland cement grade CEM I 42.5B D0 LLC "Holcim Rus" without a modifier and with modifiers polycarboxylate type S (POLYPLAST LLC and «Glass Powder) were studied. Heat release thermograms were recorded, which showed good reproducibility of the results and their similarity with those available in the literature for similar studies carried out according to standard methods using a TAM AIR isothermal calorimeter (TA Instruments). This indicates the reliability of the obtained data and the possibility of using the method proposed in this article to study the processes of hydration of cements. The maximum heat release on the thermograms of samples with a polycarboxylate modifier is observed approximately 20 h after the start of heat release monitoring. Samples without the modifier and with the glass powder modifier show the maximum heat release approximately 10 h after the start of the experiment. Analysis of the results showed that the presence of modifiers leads to increased heat release during cement hydration in relation to its initial composition. Accordingly, it takes less time to complete hydration. However, it is also necessary to take into account the possible risks of violation of the technological modes of operation of the corresponding equipment due to excessive heat release during the hydration of modified cements. For citation: Usacheva T.R., Krainova A.A., Vinogradova L.A., Oganyan V.V., Kokurina G.N., Myshenkov M.S., Anufrikov Yu.A., Shasherina A.Yu., Adamtsevich A.O. Study of the influence of modifiers on the hydration of cement by the method of isothermal calorimetry. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2024. V. 67. N 6. P. 88-93. DOI: 10.6060/ivkkt.20246706.6979.

High-Precision Calorimetry-Based Analysis of Pupal-Pharate Adult Development in Drosophila melanogaster.

In holometabolous insects, the larval body is almost completely decomposed and reconstructed into the adult body during the pupal-pharate adult stages. Therefore, the total energetic cost of this process is a key thermodynamic quantity necessary for evaluating the benefit of their life history. Here, we measured whole-body thermal dissipation of single pupae of the fruit fly, Drosophila melanogaster, during the period from puparium formation to adult eclosion as a function of age, using a high-precision isothermal calorimeter at T = 298 K. The mass-specific energy consumption during the period from the onset of larval-pupal apolysis to adult eclosion was determined to be 2.3 kJ/g for an individual of mass (adult) = 1.0 mg, while it was observed to follow Kleiber's law for individuals smaller than mass (adult) = 1.0 mg. During the pupal-pharate adult period, in addition to the U-shaped variation, several characteristic thermal dissipations related to various events, including somatic muscle contractions, ecdyses, pulsatile hormone secretion in a pharate adult, and vaporization of the exuvial fluid, were observed. The periodic bursts in the pharate adult stage grew exponentially, suggesting that the positive feedback in the metabolic system synchronized with the progression of development, making the energy consumption in this stage more efficient. The present study showed that high-precision calorimetry is a powerful and credible method for measuring not only the total energy spent during development but also the energy spent during every specific developmental event in an organism.

Effect of 2-acrylamide-2-methylpropane sulfonic acid on the early strength enhancement of calcium silicate hydrate seed

Nanomaterials are becoming widely used in cement to enhance the properties of cement-based materials. Artificially synthesized nano-C-S-H serves as a nucleation site for the hydration product C–S–H gel, facilitating its formation. This is deemed as an early strength agent to effectively promote cement hydration. Introducing comb-like polycarboxylate ether (PCE) during the synthesis of C–S–H can effectively reduce the size of C–S–H, resulting in better early strength effects. In this study, the acid-ether ratio of PCE is set at 6:1, and 2-acrylamido-2-methylpropane sulfonic acid (AMPS) substitutes acrylic acid (AA) at varying molar ratios to obtain modified PCE. Calcium silicate hydrate seed-polycarboxylate ether (C-S-Hs-PCE) is synthesized using co-precipitation technique. This study investigated impacts of AMPS on the particle size of C-S-Hs-PCE and the early strength of cement-based materials using dynamic light scattering analysis, total organic carbon analyzer, X-ray diffraction analysis, low-field nuclear magnetic resonance, scanning electronic microscopy, isothermal calorimeter, and compressive strength testing. The results show that the C-S-Hs-PCE, synthesized at an AMPS to AA molar ratio of 5:95, turns out to possess a reduced particle size compared to use of PCE without AMPS. This is pivotal in promoting the hydration of the silicate phase and the formation of calcium hydroxide and C–S–H gel in the paste, and thereby reducing the total porosity while improving the early mechanical strength of the mortar, especially within first 24 h.

Insights into microstructural alterations in alkali-activated materials incorporating municipal solid waste incineration fly ash

Municipal solid waste incineration fly ash (MSWI FA) is categorized as a hazardous waste with significant implications on environmental safety and human health. This study tailored three types of alkali-activated materials (AAMs) by using ground granulated blast-furnace slag (GGBS) and metakaolin (MK) for the low-carbon stabilization/solidification (S/S) of MSWI FA. The intricate interactions between MSWI FA and AAMs synthesized from Al-rich precursors and Ca-rich precursors were investigated to elucidate the microstructural alterations of AAM-MSWI FA systems. Comprehensive characterization techniques were conducted, including isothermal calorimeter, thermal gravimetric analysis, Fourier-transform infrared (FTIR), X-ray diffraction (XRD), and 27Al and 29Si nuclear magnetic resonance (NMR). The results revealed that the incorporation of MSWI FA significantly delayed alkali activation reactions, hindering the formation of aluminosilicate gel due to high contents of Cl and potentially toxic elements (PTEs) in the MSWI FA. High volume of dissolved Cl from MSWI FA would react with available Ca from MSWI FA and GGBS as well as Al from GGBS and MK to form Friedel’s salt, and this reaction was found to be more dominant in the Al-rich environment. Meanwhile, the C-(N-)A-S-H gel exhibited longer chain length in the Al-rich environment than in the Ca-rich environment. Overall, this study delivers microstructural insights into AAM-MSWI FA systems utilizing GGBS and MK as precursors. The results provide scientific groundwork for diverse practical applications of AAM-MSWI FA materials, thereby supporting the development of resource-efficient and low-carbon hazardous waste treatment strategies.

Influence of cathode materials on thermal characteristics of lithium-ion batteries.

In this work, the thermal stability of four types of 18,650 lithium-ion batteries with LiCoO2 (LCO), LiFePO4 (LFP), LiNi0.8Co0.1Mn0.1O2 (NCM811) and LiNi0.8Co0.15Al0.05O2 (NCA) materials as cathodes are experimentally investigated by the accelerating rate calorimeter (ARC) and the isothermal battery testing calorimeter (iso-BTC) under adiabatic and isothermal conditions, respectively. The thermal runaway danger level of these batteries can be ranked as LCO > NCA > NCM811 >> LFP by judging from the values of Tmax and HRmax, nominal. The higher the nickel and cobalt content, the higher the lithium-ion battery capacity, but the worse the thermal stability. The Qtotal of NCA is the largest in the complete standard charge and discharge process, due to that the capacity of NCA is significantly higher than that of the other three batteries, resulting in remarkable increase in Qirre proportioned to the square of the current. When the ambient temperature rises, the energy release decreases owing to the decrease in the internal resistance of the battery. These studies are expected to have important implications for the subsequent safe design of commercial lithium-ion batteries with different cathode materials.

Preparation and accelerating mechanism of alkali-free liquid accelerator made with silicon residue containing fluorine

Fluorine-containing silicon residue (FSR) is a solid waste that is harmful to the environment. A new alkali-free liquid accelerator based on aluminium sulfate (LAFS) was prepared using FSR. The addition of LAFS to cement mortar shortened the setting times and significantly improved the early strength. With the addition of 8% LAFS, the initial and final setting times were 2.48 min and 11.83 min, respectively, and the 1-day compressive strength was 14.6 MPa, which was 200% of that of the mortar without LAFS. The mechanism of the action of LAFS was studied using isothermal calorimetry test, X-ray diffraction, thermogravimetric analysis, scanning electron microscopy and other analytical methods. The results showed that the LAFS rapidly generated a large amount of ettringite and promoted the formation of calcium silicate hydrate in the cement paste. A conceptual model of the early hydration process of cement paste with added LAFS was established based on the analytical results.

Enhancing strength of cement using aluminium sulfate accelerator with aluminium formate

An alkali-free liquid accelerator was prepared with aluminium sulfate and aluminium formate as the main components. The effects of the accelerator on the setting of paste and the mechanical strength of mortar were studied, and the impact of the accelerator on the early hydration behaviour and hydration products of the paste were investigated by isothermal calorimeter analysis, X-ray diffraction analysis, scanning electron microscopy and thermogravimetric analysis. The results show that the accelerator is excellent for the rapid setting and hardening of the cement. When the content of the accelerator was 8 wt%, the initial setting time and final setting time of the paste were 85 s and 180 s, respectively, and the strengths of the mortar at 1 day and 28 days were 9.52 MPa and 44.42 MPa, respectively. The proposed accelerator can accelerate the dissolution and hydration of tricalcium aluminate and tricalcium silicate and promote the formation of ettringite, formate and portlandite.

Analysis of Maximum Growth Rate and Construction of Predictive Growth Model for Bacillus cereusin Mashed Potato by Calorimetric Method

The maximum growth rate (μmax) of Bacillus cereus was estimated using a non-destructive isothermal calorimetric method, and a growth prediction model was constructed based on the measurement results. SCD medium and mashed potato were inoculated with serial-diluted inoculum of B. cereus. Heat generation curves were determined using an isothermal calorimeter at 35, 25, and 15℃. The μmax was determined from the relationship between the increase in B. cereus cell number and incubation time, which was detected through the heat generation of the B. cereus biological process. Moreover, the growth prediction model was constructed using Ratkowsky's square-root model. The results of the growth prediction model based on the data of the calorimetric and conventional culture methods for SCD were expressed as √μCalmax=0.0354 (T-4.9)[R2=0.99] and √μCCMmax=0.0335 (T-5.0)[R2=0.99]; a similar equation was provided by both methods. Conversely, the results of the growth prediction model based on the calorimetric method data for mashed potato were given as √μCalmax=0.0390 (T-8.5)[R2=0.99]; the maximum growth rates at 30 and 20℃ were predicted as 0.70 and 0.20 (1/hr), respectively. The maximum growth rates obtained using the conventional culture method were 0.63 and 0.29 (1/hr), respectively, similar to the calorimetric method results. The predictive microbiological analysis using the calorimetric method enabled the rapid provision of a growth prediction equation, and the number of samples could be substantially reduced compared with that for the conventional culture method.

Thermodynamic and structural investigation of the interaction of quaternized 2,3-octakis-[(2-mercaptopyridine)phthalocyaninato] copper (II) sulfate (CuPc) with parallel and hybrid type G-quadruplex.

G-quadruplexes are important drug targets and get attention due to their existence in telomere, ribosomal DNA, promoter regions of some oncogenes, and the untranslated regions of mRNA. Due to the biological roles of G-quadruplexes, investigating of the G-quadruplex-small molecule interaction is essential. The primary motivation for these studies is the possibility of inhibiting cell functions associated with G-quadruplex sequences by binding with small molecules. Targeting the small molecules to desired tissue with the G-quadruplex vehicles is the second important goal of the G-quadruplex-small molecule interaction studies. In the present study, the new peripherally 2-mercaptopyridine octasubstituted copper(II) phthalocyanine and its quaternized derivative (CuPc) were synthesized and characterized by elemental analysis FT-IR, UV-Vis, and mass spectra. The excellent solubility of CuPc in water is essential for its transport in the organism. Because of this feature, its affinity toward G-quadruplex forming aptamers, AS1411, Tel21, and Tel45, was investigated. The UV-Vis spectrophotometric titration data confirmed the prevention of aggregation upon interaction with G-quadruplex, which is very important for biomedical applications. The CD spectroscopic analyses and binding stoichiometry confirmed the "end stacking" model for interaction of AS1411 with CuPc. The interaction of CuPc caused the equilibrium shift from hybrid conformation to antiparallel conformation for Tel21 and Tel45. The isothermal titration calorimeter (ITC) was used for the determination of thermodynamic parameters. The thermodynamic data of the interaction was fitted well with the one-site model. The negative values of Gibbs free energy change confirmed the spontaneous nature of the reactions. Besides, the negative values of enthalpy change and entropy change proved that the nature of processes was "enthalpy driven." The interaction stoichiometry was 2 for AS1411 and Tel21 and 1.5 for Tel45. The binding constants were 1.3(±0.3) × 105 , 3.2(±0.4) × 105 , and 1.1(±0.3) × 105 M-1 , which were at the level of ethidium bromide intercalation binding constant given in the literature. The DNA polymerase stop assay further supported the interaction of CuPc with G-quadruplex DNA. The experimental results confirm that the CuPc has a potential photosensitizer behaviour for photodynamic therapy.

Assessing the feasibility of recovering heat from Mung Bean sprout production for food consumption

Given the current challenges posed by climate change and depletion of conventional fuel resources, there is a need to focus on improving energy efficiency through the recovery of waste energy. One such potential source of low-temperature waste heat is the process of seed germination during food plant cultivation. In traditional production facilities, germinating plants generate low-temperature heat (20–40 °C), which is typically discharged into the environment. This paper presents a study on the heat recovery potential of germinating Mung bean seeds under laboratory and controlled cultivation conditions using an isothermal calorimeter and a process line, respectively. This study represents the first quantitative determination of the heat generated during the Mung bean sprout production cycle, and a comparison of the changes in emitted heat on both micro and macro scales. Additionally, the research includes the first determination of the amount of energy generated by Mung bean sprouts using microcalorimetric studies lasting up as long as 120 h. The paper determines the amount of heat generated and estimates the possible and actual heat recovery potential. The results show that the average amount of heat generated in the calorimetric studies is 2.43±0.72 kJ/gseeds, while under controlled cultivation conditions it is 2.29 kJ/gseed. These findings highlight the significant potential for recovering waste heat from germinating seeds, which can be harnessed to improve the energy efficiency of the food sprout production process. In addition, the calorimetric method is suitable for determining the energy potential of plants and facilitating the design of the most efficient crop cultivation techniques in terms of energy consumption.

Hydration Heat and Hydration Kinetics of Cement Paste Compound with Molybdenum Tailings Powder: A Research Article

Molybdenum tailings powder (MTs) has potential pozzolanic activity and can be used as a mineral admixture. In order to comprehend the influence of MTs powder on the cement hydration process, the hydration heat and kinetics of composite cementitious materials (CCMs) were investigated using an isothermal calorimeter and the Krstulovic–Dabic model. Furthermore, the influences of fly ash (FA), slag (SL), and MTs powder on hydration heat were compared and analyzed, considering the same content. The results show that the proper amount of MTs can promote the hydration of CCMs. When the content of MTs is 5% and 15%, the second exothermic peak of the CCMs appears 2.30% and 4.27% earlier, and the exothermic peak increases by 2.72% and 1.34%, respectively. The cumulative heat release of CCMs gradually decreases with an increasing content of MTs powder. When the replacement of MTs, FA, and SL is 15%, respectively, the second exothermic peak of CCMs increases by 1.34%, −16.13%, and −12.04% for MTs, FA, and SL, respectively. The final heat release of MTs is higher than that of FA, but lower than that of SL. The hydration process of CCMs undergoes three stages: nucleation and crystal growth (NG), interactions at phase boundaries (I), and diffusion (D).

Calcined paper mill lime mud as an activator in GGBFS-based cementless UHPC

This study investigates the potential use of calcined lime mud as an activator in the development of a sustainable, ground granulated blast furnace slag (GGBFS)-based cementless UHPC. The effects of the calcination temperature (550 °C to 850 °C) of lime mud and its weight percentage in the UHPC mixture were evaluated with various tests, such as compressive strength, isothermal calorimeter, and thermogravimetric analysis. Microstructural changes and pore size distribution were also analyzed using XRD, FTIR, and MIP. The results showed that calcined lime mud can be an effective activator in the UHPC mix, and its mechanical properties are influenced by the calcination temperature and weight percentage. The addition of 10% calcined lime mud enhanced the compressive strength of the UHPC up to 150 MPa without negatively affecting its microstructural and hydration characteristics, suggesting that calcined lime mud has the potential to be used as a sustainable alternative to CaO in GGBFS-based cementless UHPC.

Isothermal battery calorimetry analysis on a thermal behavior of Li-ion battery for electric vehicle

This paper presents the development of an isothermal battery calorimeter (IBC) for analyzing the thermal characteristics of high-capacity lithium-ion pouch cells used in electric vehicles. The IBC incorporated a Peltier module to maintain an isothermal environment within the test cell, and a PID control was employed for the operation. A Positive-Thermal-Coefficient (PTC) heater was used to calibrate the IBC and determine the heat generation rate of the battery during operation. The heat generation rate of a lithium-ion battery (LIB) was measured under various load conditions, including constant current discharge and driving profiles. The results were compared with those of conventional methods, such as equivalent electric circuit model (EECM)-based simulation and inverse heat analysis. This comparison demonstrated that the IBC accurately captured the thermal behavior of the pouch cell, which exhibited changes in the state of charge (SOC), similar to the inverse heat analysis. Additionally, the IBC effectively identified specific regions with significant heat generation, thus facilitating in the detection of serious heat problems within the battery under driving load conditions. Although a time delay in the heat generation rate was observed in the IBC, owing to the thermal inertia of the Peltier module, this issue could be mitigated by reducing the thermal mass of the module.

Inhibiting NOXO1 and CYBA binding to reduce NADPH oxidase I dependent ROS damage in skin explants

NADPH oxidases (NOXs) are newly identified enzymes that generate intracellular reactive oxygen species (ROS) in skin cells. Recent studies demonstrated that NOX1 holoenzyme is expressed in human keratinocytes and melanocytes, which are implicated in skin photo-carcinogenesis due to the high amounts of ROS produced. Holoenzyme activation requires a ternary complex comprised of NOX1, cytochrome B alpha chain (CYBA), and cytoplasmic NADPH Oxidase Organizer 1 (NOXO1) to properly form. By inhibiting this assembly process, an opportunity for reducing the production of catalytic ROS is possible, especially during high ROS conditions that occur under prolonged UV exposure. We designed a series of small molecules and evaluated their inhibitory effects on NOXO2 using in-silico docking methods in the 1WLP crystal structure. We show that the NOX_inh_5 inhibitor was successful in a variety of experiments using primary skin models from various skin tones. NOX_inh_5 proved to be non-cytotoxic while also improving the viability of primary human skin primary cells under UV exposure. Biophysical studies with NOX_inh_5 using an Isothermal calorimetric (ITC) binding and heteronuclear single quantum coherence (HSQC-NMR) exhibited inhibition of complex formation between NOXO2 and CYBA. Authentic human skin explants, treated with and without NOX_inh_5 and UV exposure, decreased p53 stabilization and decreased UV-induced DNA damage as quantified through cyclobutane dimer formation.