Complex Series Of Reactions Research Articles

Dielectric barrier discharge plasma in-situ microbubble aeration with peroxymonosulfate for levofloxacin degradation: Microbubble superior performance and pH-dependent mechanism

In this study, a simple ceramic membrane aeration was used to realize dielectric barrier discharge/peroxymonosulfate (DBD/PMS) in-situ microbubble aeration for effective dispersion and gas–liquid transfer of highly active substances. Compared with conventional aeration, ceramic membrane aeration had 18 times fewer microbubble diameters (110–180 µm), much higher bubble densities, and 1.6–2.1 times higher aquatic O3 concentrations at pH 4.8–10.0. Consequently, the yield of HO and SO4·- was 1.64–2.34 and 1.13–2.93 times, respectively, via faster O3 transfer to the aquatic solution and enhanced PMS activation. DBD/PMS microbubble aeration outperformed conventional aeration, with a 2.52-fold increase in LEV degradation kinetics and a 2.79-fold increase in TOC removal. Quenching and EPR experiments showed that HO and 1O2 were the main reactive oxygen species (ROS) for LEV degradation. The yield of O2·- was higher at pH 6.9, while HO, SO4·-, and 1O2 was higher at pH 8.7 derived from a series of complex reactions. The LEV degradation pathway was pH-dependent, with the HO-oxidation contribution varying from 25.3% to 44.3% as the pH increased from 4.8 to 8.7, while other ROS (1O2 and O2·-)-oxidation decreased from 73.1% to 51.8%. Therefore, this work will advance the current understanding of the intrinsic effects of pH in the plasma/PMS microbubble process for wastewater purification.

Edaravone Alleviates Traumatic Brain Injury by Inhibition of Ferroptosis via FSP1 Pathway

Traumatic brain injury (TBI) is a highly severe form of trauma with complex series of reactions in brain tissue which ultimately results in neuronal damage. Previous studies proved that neuronal ferroptosis, which was induced by intracranial haemorrhage and other reasons, was one of the most primary causes of neuronal damage following TBI. However, the association between neuronal mechanical injury and ferroptosis in TBI and relevant treatments remain unclear. In the present study, we first demonstrated the occurrence of neuronal ferroptosis in the early stage of TBI and preliminarily elucidated that edaravone (EDA), a cerebroprotective agent that eliminates oxygen radicals, was able to inhibit ferroptosis induced by TBI. A cell scratching model was established in PC12 cells, and it was confirmed that mechanical injury induced ferroptosis in neurons at the early stage of TBI. Ferroptosis suppressor protein 1 (FSP1) plays a significant role in inhibiting ferroptosis, and we found that iFSP, a ferroptosis agonist which is capable to inhibit FSP1 pathway, attenuated the anti-ferroptosis effect of EDA. In conclusion, our results suggested that EDA inhibited neuronal ferroptosis induced by mechanical injury in the early phase of TBI by activating FSP1 pathway, which could provide evidence for future research on prevention and treatment of TBI.

Quality investigation of the most consumed refined seed oils after French fries’ domestic short-term deep-frying process

Deep-frying is an attractive food preparation method and has been in use for centuries. It is a very popular culinary practice worldwide and can be used both industrially and domestically. Deep-fried food has a unique sensorial property, such as flavor, aroma, and texture. However, the chemical quality of the frying oil can be affected by the high temperatures normally used in deep-frying. Complex series of reactions that occur in vegetable oils during deep-frying (hydrolytic and oxidative rancidity processes) they are related to several mechanisms, such as reactive species, chemical composition of the lipid, environment, and process, influencing the speed and nature of the oxidative process. This paper aimed to analyze the quality of the vegetable oils most consumed by the population (refined soybean and sunflower oils) used in domestic short-term deep-frying process, using a domestic-grade electric fryer and a conventional method. French fries were used because they are a convenient product, highly consumed in industrialized countries. Domestic events of short-term deep-frying were carried out for three days, with one-week intervals. After each frying events, the refined oils were analyzed. Methodology consists in bromatological analyses of quality research applying analyzes of acidity and peroxide, in which the free acidity content, compounds formed by hydrolytic rancidity, and hydroperoxides content, the first compounds formed in the oil´s oxidative rancidification process, were analyzed. These parameters will be fundamental in oils oxidative evaluating during frying. According to the results, fresh vegetable oils samples remained within regulatory limits. However, after short-term deep-frying, free fatty acids and hydroperoxides content increased in both domestic short-term deep-frying using both vegetable oils, exception of sunflower oil after last day of frying. Additionally, there was no significant difference in the fatty acids value increase comparing with both domestic frying techniques. However, there was significant difference in hydroperoxide value comparing the oils between deep-frying techniques. However, in general even the oils have shown great thermal quality, bromatological analyses demonstrated that must be taken careful when reusing oils for short-term deep-frying. Seeing that the electric fryer is effective in oil quality compared preservation comparing with conventional method, probably due to temperature control and better sealing efficiency.

Abstract C103: Non-enzymatic glycoxidation reports on society, environment and biology to inform on enduring cancer disparities

Abstract Disparities in overall cancer outcomes have been reduced across racial and ethnic divides, but still persist for some tumor types and have increased for others. This has stimulated significant debate regarding whether the enduring nature of cancer disparities arises solely out of inherent failings in addressing health inequities, or does an individual’s inherent biology also play an accompanying role. As a newly termed “bio-social determinant of health”, non-enzymatic glycoxidation profiles may represent an unexploited opportunity to consider how health inequity constructs combine to impact cancer outcomes across transdisciplinary studies. Resulting from the combined processes of glycation and oxidation, non-enzymatic glycoxidation is a complex series of reactions, leading to the irreversible posttranslational modification of peptides, lipids and nucleic acids by Advanced Glycation End Products (AGEs). Evidence is presented to support that health inequity constructs can serve to provide a superfluous source of the reactive substrates that sustains non-enzymatic glycoxidation resulting in a chronic cycle of AGE formation, bioavailability, and pathogenicity. AGEs are significant because: 1. Communities who bear the highest cancer burden are more likely to be exposed to health inequity risk factors that serve to increase AGE bioavailability 2. When health equity is compromised complex relationships are created between social and biological determinates of health that serve to overwhelm the fragile rheostat that maintains AGE homeostasis.; and 3. Increases in AGE bioavailability are associated with increased tumor growth and progression through their impact on the tumor microenvironment. Glycoxidation patterns visualized by AGE accumulation and pathogenic function may serve as a “bio-social determinant of health” as they may reflect the dynamic and varied nature of multiple health inequity constructs and their combined effects on cancer incidence and mortality. In turn this may allow a greater understanding of the complex relationships that exist between societal, ancestral, environmental, and biological constructs, and lifestyle associated risk factors associated with enduring cancer disparities. This would provide significant insight on novel cancer prevention and control strategies aimed at reducing AGE exposure due to health inequity. Citation Format: David P. Turner. Non-enzymatic glycoxidation reports on society, environment and biology to inform on enduring cancer disparities [abstract]. In: Proceedings of the 16th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2023 Sep 29-Oct 2;Orlando, FL. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2023;32(12 Suppl):Abstract nr C103.

Numerical Simulation of Plasma Plume With Gas–Surface Interaction and Chemical Reaction Coupling Effect Based on DSMC-PIC Parallel Algorithm

The spatio-temporal evolution of plasma plumes is accompanied by a series of complex chemical reactions and gas–surface interactions that crucially affect the working characteristics and performance of plasma devices. The direct simulation Monte Carlo (DSMC) and particle-in-cell (PIC) hybrid parallel algorithm is often used to numerically simulate such phenomena. This article discusses the gas–surface interaction models of neutral molecules as elucidated by the parallel DSMC-PIC program. These models include the Maxwell model, the Cercignani–Lampis–Lord model, the complete diffuse reflection (CDR) gas–surface reflection model, and coupling with H combined reactions at the wall. Meanwhile, we consider the ion gas–surface interaction models, which include the CDR model and coupling of the four wall chemical reactions of ions. In addition, the dissociation reactions of H2 and recombination reactions of H are considered in the flow field. For various combinations of models, the simulations reveal the structural characteristics, number density, and coupling effects of gas–surface reflections, gas–surface chemical reactions, chemical reactions in the flow field and electric field, and spatio-temporal evolution of H2, H, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$X$ </tex-math></inline-formula> , <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{H}_{2}^{+}$ </tex-math></inline-formula> , and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{H}^{+}$ </tex-math></inline-formula> , which are shown by the structural characteristics of the number-density contours for different model combinations and analyzed in detail. The gas–surface interaction critically influences the number-density distribution near the wall and in the main flow. It also strongly affects the number-density distribution of light neutral molecules but not heavy neutral molecules and ions and produces the wall stacking effect. Apart from the stacking area, it has an indirect influence on the number-density distribution. The chemical reactions of ions on the wall affect the number-density distribution of all particles in the flow field and decisively affect the ions near the wall. Acceleration by the electric field intensifies the ion diffusion. The effect of coupling of gas–surface interaction and acceleration by the electric field is obvious. Via the number density and temperature, the chemical reactions in the flow field strongly affect the distribution of neutral molecules at the inlet; further, from the inlet, this effect weakens. Neutral particles and ions interact mainly through collisions.

The Smell of the Kitchen

When you cook, do you know why it smells so good (or so bad) in the house? It is all about chemistry. All over the world, cooking is based on tradition and love, but it is the chemistry of the foods that allows recipes to succeed or not. Among the chemical reactions that occur in cooking food, the Maillard reaction, which occurs between amino acids and sugars, is the most familiar. This is actually a complex series of reactions that lead to the formation of aromas, tastes, and colors as food cooks. In this article, we will discuss the most important stages of the Maillard reaction that happens when we bake, barbecue, or otherwise cook foods. Once the Maillard reaction is complete, you just have to say, “enjoy the meal!”

Direct observation of dynamic surface reconstruction and active phases on honeycomb Ni3N−Co3N/CC for oxygen evolution reaction

Oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) are the key processes in water splitting. Compared with the two-electron process in HER, the four-electron process of OER is slow because of the more complex series of reactions. Therefore, a good understanding of the direct O2 evolution mechanism (DOEM) in OER is crucial to design high-efficiency catalysts to overcome the limitations imposed by the conventional adsorption evolution mechanism. In this work, honeycomb Ni3N−Co3N was prepared on carbon cloth (Ni3N−Co3N/CC) to investigate the DOEM. Density functional theory and in situ Raman scattering spectroscopy demonstrated that the OER process on Ni3N−Co3N/CC proceeded via the DOEM pathway, in which Ni3N and Co3N share the roles of dragging OH−, splitting off H−O bonds, and adsorbing other OH−, leading to significantly reduced Gibbs’s energy barriers of ΔG*OH to ΔGO*. and ΔGO* to AGO*OH. Moreover, the vertical honeycomb structure and conductive CC substrate contributed to the structural stability, conductivity, and quick O2 release capability. The Ni3N−Co3N/CC required low overpotentials of 320 and 495 mV to reach a current density of 10 and 100 mA cm−2, respectively. Moreover, the Ni3N−Co3N/CC delivered excellent stability with >90% retention of the initial current density over an 80-h-long test.

Curry leaf (Murraya koeneigii) extract as a natural source of antioxidants for enhancing the oxidative and thermal stability of ghee

Ghee is used for making various sweets and dishes in addition to its various culinary purposes. In the course of such preparations, ghee is subjected to different degrees of heat treatment which on combining with air can undergo considerable physico-chemical changes. The high temperature cooking process creates a series of complex chemical reactions in ghee which affects the sensory and the functional properties of foods as well as the ghee used. This leads to adverse health effects on consumers. One of the best ways to protect ghee from autooxidation and thermal oxidation is by the incorporation of antioxidants during their processing. Addition of synthetic antioxidants is restricted in several countries. Scientific investigations have also found that the use of synthetic antioxidants in foods may harm the liver and lead to the development of cancer. The aim of the present study was to check the effect of curry leaves (Murraya koeneigii) extract on the thermal stability of ghee. Based on the peroxide and thiobarbituric acid (TBA) value determinations, it was observed that quality of ghee samples added with 1 % CLE during frying was significantly higher than that of control (ghee without antioxidant) and ghee added with 0.02 % BHA (a synthetic antioxidant). At 15 minutes of frying (180°C), the peroxide value was 3.615±0.24, 1.04±0.10 and1.07±0.02 mM O2/kg fat for the control, BHA added and CLE added ghee respectively and this increased to 8.23±0.23, 6.47±0.21 and 4.0±0.01 mM O2/kg fat after 60 minutes of frying, respectively. Findings suggested that CLE could be used as a source of natural antioxidants for imparting thermal stability to ghee during frying.

Coupling 1D blood circulation model and substance absorption model to study drug metabolization

The introduction of substances into the bloodstream initiates a complex series of chemical reactions. The study of drug absorption, metabolization and excretion processes is relevant for a better understanding of current treatments, by providing a better understanding, which helps improve them or propose new methods. In this project we propose a novel model for drug absorption, which is obtained by coupling a ID full-body blood flow model with the Wagner-Nelson absorption equation for a single compartment model through two established elimination rates Ket. For our experiments, we take the constant values from previous studies on the intravenous administration of ibuprofen and epinephrine, having Ket = 0.32 per hour, and Ket = 0.2 per minute respectively, and one large Ket = 3200 per hour to test absorption in a detailed full-body model. Our result plots show a decay in the concentration of drug over the time, which reflects the correct coupling of our models with the subtraction of drug amounts and the update of the current drug concentration by the absorption model over our ID blood flow model. To overcome resources limitations, we run our simulations for short periods of time, with an increased Ket value in the same order to generate an accelerated decay of the drug concentration in a more detailed model.

Binary V, Mn Oxide/Hydroxides rGO As High Sulfur Content Hostmaterials for Lithium-Sulfur Battery

Lithium-sulfur battery (Li-S) owing to the high theoretical energy density (2600 Wh kg-1) and high theoretical capacity (1675 mA h g-1) is one of the most promising candidates to replace Lithium-ion batteries (LIBs). However, contrary to conventional Li-ion batteries, Li/S cells transport charge via a series of complex chemical reactions involving solid and soluble sulfur species, which can cause severe morphological changes of the positive electrode and induce the shuttle mechanism. In order to enables the reversible electrochemical reaction of Li-S battery especially at high current rates, not only confined sulfur in highly conductive host materials is a key factor, but also the cathode materials have to provide enough polarity in order physically bonded LiPSs and mitigate shuttle mechanism. Among different metal oxides, Vanadium and Manganese oxides due to special metal-insulator transition, high adsorption ability toward LiPSs in addition to electrocatalytic effect of Mn oxide in the reduction of soluble LiPSs to Li2S2 and Li2S, exhibit part of the requirements of sulfur cathode material1,2.Here in, we report synthesis of bimetallic nanorod V/Mn hydroxides/oxides on the surface of reduced graphene oxide nanosheets (rGO) by a simple one step hydrothermal method and followed by thermal calcination in the N2 atmosphere. Indeed, rGO which benefits from high electrical conductivity and also high surface area, provide a well-distributed pattern of transition metal-based structures. The above-mentioned composite is able not only to alleviate the LiPSs shuttle by anchoring the LiPSs species but also electrocatalytically improve the LiPSs conversion process in the discharge state of the Li-S battery. The synergetic effect of V and Mn in different oxidation state was evaluated using several ratios V/Mn. The behaviors of the electrode, composed by the V/Mn-rGO/S composite with 80% of S, in term of capacity, cyclability and also electrocatalytic effect in Li-S battery were investigated.Figure 1. shows the well-dispersed VxMnyNrGO( x,y represent the molar raio and N represent N-doped rGO after calcination) on the rGO nanosheets and the performances and cyclability of the different cells at 0.2C. The sulfur loading of all the cathodes are 1.9 mg/cm2 and the E/S ratio is about 12µL per mg of Sulfur.Figure 1 a) SEM image of V,Mn oxide on the surface of rGO, b) Decharge capacity vs cycle number (1.9mgS/cm2) of different materials.The best result with a stable capacity of 700 mAh/g up to 45 cycles was obtained for the V1Mn1rGO cathode (1:1 molar ratio V and Mn without calcination). This very promising results have to be optimized in order to improve the performances at high C-rate, indeed because of high percentage of Sulfur in the V/Mn-rGO based composite, cycling batteries in higher C rates facing obstacles.(1) Song, Y.; Zhao, W.; Zhu, X.; Zhang, L.; Li, Q.; Ding, F.; Liu, Z.; Sun, J. Vanadium Dioxide-Graphene Composite with Ultrafast Anchoring Behavior of Polysulfides for Lithium–Sulfur Batteries. ACS Appl. Mater. Interfaces 2018, 10 (18), 15733–15741. https://doi.org/10.1021/acsami.8b02920.(2) He, J.; Hartmann, G.; Lee, M.; Hwang, G. S.; Chen, Y.; Manthiram, A. Freestanding 1T MoS 2 /Graphene Heterostructures as a Highly Efficient Electrocatalyst for Lithium Polysulfides in Li–S Batteries. Energy Environ. Sci. 2019, 12 (1), 344–350. https://doi.org/10.1039/C8EE03252A. Figure 1

Study the effects of methane disulfonic acid sodium salt on Cr (VI) reduction using rotating disk electrode

Chromium (VI) electroplating plays a vital role in the surface engineering industry for metallic materials due to its high hardness and excellent chemical stability. However, the reduction of Cr (VI) is a series of complex reactions that exhibits low current efficiency. As such, this low current efficiency in the process poses a significant challenge in the adoption of CR (VI) electroplating in the surface engineering industry. Methane disulfonic acid sodium salt (MDAS) is an essential catalyst for Cr (VI) electroplating. In this work, the effects of MDAS on the current efficiency of Cr (VI) electroplating process is studied. It is discovered that the current efficiency increases to about 17% when 4–6 g l−1 MDAS is added in the bath, which is an improvement over the current efficiency of 12% for its counterpart without MDAS. Furthermore, rotating disk electrode method is employed to investigate its interaction mechanism with regards to the reactions which have occurred during this process. It indicates that MDAS demonstrates a remarkable catalytic ability towards the electrochemical reaction which occurs at the lower-potential peak. This lower potential peak corresponds to the electrochemical reaction of Cr (VI) to Cr (0) or Cr (III) to Cr (0).

Catalytic Kinetics Considerations and Molecular Tools for the Design of Multienzymatic Cascade Nanoreactors

AbstractWithin the cellular microenvironment of organisms, the surface‐ and volume‐ enclosed multiple enzymes perform highly complex series of chemical reactions for very selective and efficient synthesis of biomolecules. Several efforts have been carried out to mimic these timely and spatially defined natural enzyme cascade reactions onto the artificial multienzyme nano‐assemblies via immobilization of two or more enzymes on nanosupport, while maintaining the catalytic activity. These biocatalytic systems undergo cascade reactions for the efficient production of chemicals and materials of interest. Their increasing interest is based on their numerous potential applications in the area of environmental, biomedical and applied chemistry. A variety of nanosupports and multienzyme immobilization techniques have been optimized and reported. Nanoreactors usually show molecular crowding and anomalous diffusion of substances that modify the mass action kinetic laws. Thus, the kinetics is different than those shown by free diluted enzymes. Consequently, the catalytic activity considerations in cascade reactions on nanoassemblies are of great importance. Thus, in this work, important parameters of enzyme kinetics in cascade reaction and the molecular tools for the design and optimization of bi‐ and multi‐enzymatic nanobioreactors reactions are discussed.

Study of heterogeneous reaction of dimethyl sulfide on atmospheric-like particulate TiO2

Dimethyl sulfide (DMS) related to solar radiation and greenhouse effect is one of the most important volatile sulfides and its' oxidation products are also important contributors to acid rain. It is of great importance to study the consumption and reactions of DMS in the atmosphere. In this work, atmospheric-like particulate TiO2 was selected to study the reaction mechanism of DMS on TiO2 with the purpose to explore the possible heterogeneous oxidation of DMS. The results showed that the heterogeneous reaction of DMS with TiO2 occurred under the condition of illumination, which is a first-order-like reaction with the rate constant K = 2.83 × 10−4/s, the initial reaction uptake coefficient and the steady reaction uptake coefficient indicated the occupation of products and by-products on the surface of TiO2. The heterogeneous reaction mechanism of DMS studied by aerosol time-of-flight mass spectrometry (ATOFMS) suggested that DMS underwent a series of complex chemical reactions with sulfate and various sulfur-containing gas products, in which hydroxyl radicals might play an important role.

Melanogenesis — an update

Human skin and hair colour are due to a pigment, melanin, which is produced at the dermal epidermal level by specialized cells, the melanocytes, in a process named melanogenesis.The melanocytes are derived from their precursors, melanoblasts, with migrate to their definitive locations in the course of the final steps of embryogenesis. The melanocytes produce melanosomes, small organelles where melanin synthesis will take place. There are four stages of development of melanosomes, and only from the third stage onward melanosomes can synthesize melanin. Then, the transfer of melanin from the melanocytes to the keratinocytes can take place. According to the individuals, there is a phenotypic diversity of pigmentation, which is described in Fitzpatrick classification, and due to the ratio eumelanin (dark melanin) and phaeomelanin (reddish melanin) produced by the melanocytes. Melanogenesis is quite a complex series of chemical reactions, along which three enzymes, tyrosinase (TYR), tyrosinase-related protein 1 (TRP1) and DOPAchrome tautomerase (DCT) are absolutely required. Other enzymes also play a role in this process.Melanocortin-1 receptor (MC1R) and Microphthalmia-associated transcription factor (MITF) also play a pivotal role in the stimulation (or not) of the melanocytes. Skin pigmentation is regulated by a series of intrinsic factors such as peptides, cytokines, prostaglandins, NO, but also oestrogens. On the other hand, UV radiation (UVR) is a potent extrinsic regulator of melanogenesis. In this paper, it was emphasized on the importance of the paracrine regulation of skin pigmentation. The major role of keratinocytes is well known, but other skin cells like fibroblast, immune cells or endothelial cells are of major importance in this cell-to-cell communication with the melanocytes and will regulate melanogenesis.Finally, a brief glossary was proposed about various existing melanins.

Crude-Oil-to-Chemicals (COTC) projects to boost capacity

A complex series of reactions (Table 7.1) take place when gas oil and/or residue molecules come in contact with 1200 °F to 1400 °F (650 °C–760 °C) FCC catalyst. The distribution of products depends on many factors, including the nature and strength of the catalyst acid sites. Although most of the cracking reactions in the FCC are catalytic, thermal cracking reactions also occur. Thermal cracking reactions are caused by cracking severity, feedstock quality, catalyst properties, non-ideal contact of the oil and catalyst in the bottom of riser, degree of catalyst back-mixing and long residence time in the reactor housing.

Microstructure and microhardness of a novel TiZrAlV alloy by laser gas nitriding at different laser powers

The Ti–20Zr–6.5Al–4V (T20Z, wt%) alloy surface was treated by the process of laser surface nitriding. The evolution of microstructures and microhardness has been investigated by changing the laser power parameter from 120 to 240 W. All laser-treated T20Z samples show two regions with distinctly different microstructural features, as compared with the untreated substrate: dense TiN dendrites and (α + β) − Ti (remelting zone, RMZ), nanoscale α laths doped with part of β phase (heat-affected zone, HAZ). The formation of TiN dendrites can be analyzed by a series of complex reactions during the process of melting and solidification. The increase in laser power results in the increase in content of TiN dendrite which is mainly due to the increase in energy input. In HAZ, the self-quenching effect leads to the formation of nanoscale α laths and the residue of β phase. Microhardness profile of different regions was measured from the surface to the interior, and the highest microhardness was obtained (~ HV 916.8) in the RMZ, as the laser power was set to 240 W. In the present study, we explained various microstructural characteristics induced by laser surface nitriding treatment.

Modeling of goethite iron precipitation process based on time-delay fuzzy gray cognitive network

The goethite iron precipitation process consists of several continuous reactors and involves a series of complex chemical reactions, such as oxidation reaction, hydrolysis reaction and neutralization reaction. It is hard to accurately establish a mathematical model of the process featured by strong nonlinearity, uncertainty and time-delay. A modeling method based on time-delay fuzzy gray cognitive network (T-FGCN) for the goethite iron precipitation process was proposed in this paper. On the basis of the process mechanism, experts’ practical experience and historical data, the T-FGCN model of the goethite iron precipitation system was established and the weights were studied by using the nonlinear hebbian learning (NHL) algorithm with terminal constraints. By analyzing the system in uncertain environment of varying degrees, in the environment of high uncertainty, the T-FGCN can accurately simulate industrial systems with large time-delay and uncertainty and the simulated system can converge to steady state with zero gray scale or a small one.

Simulation study on the effects of different flow conditions on the combustion of square fire

Combustion is a process in which light and heat are produced when a series of complex chemical reactions take place. Our life has long been inseparable from combustion, such as coal for power generation, fuel oil for car engines, rocket propulsion, waste incineration; but at the same time, with the development of the city, the damage caused by frequent fires is more serious. The purpose of this topic is to study the laws of plane flame combustion under different conditions. It is proposed to simulate the real plane fire combustion conditions with different flow conditions such as wind speed, combustion space and opening conditions, and propose relevant cognition and Countermeasures Based on this. Through the analysis of the above points, we can simulate the combustion situation of different weather and floors un-der different real conditions, different scale indoor environment and boundary conditions, so as to carry out new building requirements and planning, and lay a referential foundation for the evaluation and control of the fire scale.

Adsorption and desorption for dynamics transport of hexavalent chromium (Cr(VI)) in soil column.

Batch experiments have been carried out to study the adsorption of heavy metals in soils, and the migration and transformation of hexavalent chromium (Cr(VI)) in the soil of a vegetable base were studied by dynamic adsorption and desorption soil column experiments. The aim of this study was to investigate the effect of initial concentration and pH value on the adsorption process of Cr(VI). Breakthrough curve were used to evaluate the capacity of Cr(VI) adsorption in soil columns. The results show that the higher the initial concentration, the worse the adsorption capacity of Cr(VI). The adsorption of Cr(VI) was strongly sensitive to pH value. The capacity of Cr(VI) adsorption is maximized at very low pH value. This may be due to changes in pH that cause a series of complex reactions in Cr(VI). In a strongly acidic environment, the reaction of Cr(VI) with hydrogen ions is accompanied by the formation of Cr3+, which reacts with the soil free iron-aluminum oxide to produce hydroxide in the soil. The results of the desorption experiments indicate that Cr(VI) is more likely to leach from this soil, but if the eluent is a strong acid solution, the leaching process will be slow and persistent. During the experiment, the pH value of the effluent was in the range of 7-8.5, which tends to the original pH value of the soil. It is indicating that the soil has a strong buffer on the acid liquid. The program CXTFIT was used to fit the breakthrough curve to estimate parameters. The results of the calculation of the dispersion coefficient (D) can be obtained by this program. The two-site model fit the breakthrough curve data of Cr(VI) well, and the parameters calculated by the CXTFIT can be used to explain the behavior of Cr(VI) migration and transformation in soil columns. When pH=2, the retardation factor (R) reach at 79.71 while the value of the R is generally around 10 in other experiments. The partitioning coefficient β shows that more than half of the adsorption sites are instantaneous in this adsorption process and non-equilibrium affects the Cr(VI) transport process in this soil.

Meat flavour in pork and beef – From animal to meal

An intense meat flavour is greatly appreciated by consumers. Meat flavour is generated during the cooking process through a complex series of chemical reactions between precursors, intermediate reaction products and degradation products. The content and nature of the precursors present in the meat are affected by several factors including genetics, feed, handling of the live animals and subsequent handling of the meat. The fatty acid composition can easily be altered though feeding, especially in monogastric animals, while the carbohydrate content is more closely related to genetics (pigs), feeding in the last days before slaughter and handling at slaughter (both ante and post mortem). Ageing of the meat is not particularly important for the flavour, unless the meat is dry-aged. In comparison, cooking is crucial for the development of flavour.