Unusual Chemical Processes in Interstellar Chemistry: Past and Present

The chemistry that occurs in interstellar clouds consists of both gas-phase processes and reactions on the surfaces of dust grains, the latter particularly on and in water-dominated ice mantles in cold clouds. Some of these processes, especially at low temperature, are very unusual by terrestrial standards. For example, in the gas-phase, two-body association reactions form a metastable species known as a complex, which is then stabilized by the emission of radiation under low-density conditions, especially at low temperatures. In the solid phase, it has been thought that the major process for surface reactions is diffusive in nature, occurring when two species undergoing random walks collide with each other on a surface that has both potential wells and intermediate barriers. There is experimental evidence for this process, although very few rates at low interstellar temperatures are well measured. Moreover, since dust particles are discrete, modeling has to take account that reactant pairs are on the same grain, a problem that can be treated using stochastic approaches. In addition, it has been shown more recently that surface reactions can occur more rapidly if they undergo any of a number of non-diffusive processes including so-called three-body mechanisms. There is some experimental support for this hypothesis. These and other unusual gaseous and solid-state processes will be discussed from the theoretical and experimental points of view, and their possible role in the synthesis of organic molecules in interstellar clouds explained. In addition, their historical development will be reviewed.

Ionic Liquids and Water: Hydrophobicity vs. Hydrophilicity

Many chemical processes rely extensively on organic solvents posing safety and environmental concerns. For a successful transfer of some of those chemical processes and reactions to aqueous media, agents acting as solubilizers, or phase-modifiers, are of central importance. In the present work, the structure of aqueous solutions of several ionic liquid systems capable of forming multiple solubilizing environments were modeled by molecular dynamics simulations. The effect of small aliphatic chains on solutions of hydrophobic 1-alkyl-3-methylimidazolium bis(trifluoromethyl)sulfonylimide ionic liquids (with alkyl = propyl [C3C1im][NTf2], butyl [C4C1im][NTf2] and isobutyl [iC4C1im][NTf2]) are covered first. Next, we focus on the interactions of sulphonate- and carboxylate-based anions with different hydrogenated and perfluorinated alkyl side chains in solutions of [C2C1im][CnF2n+1SO3], [C2C1im][CnH2n+1SO3], [C2C1im][CF3CO2] and [C2C1im][CH3CO2] (n = 1, 4, 8). The last system considered is an ionic liquid completely miscible with water that combines the cation N-methyl-N,N,N-tris(2-hydroxyethyl)ammonium [N1 2OH 2OH 2OH]+, with high hydrogen-bonding capability, and the hydrophobic anion [NTf2]–. The interplay between short- and long-range interactions, clustering of alkyl and perfluoroalkyl tails, and hydrogen bonding enables a wealth of possibilities in tailoring an ionic liquid solution according to the needs.

Palladium nanoparticles/wool keratin-assisted carbon composite-modified flexible and disposable electrochemical solid-state pH sensor

Several pH-dependent processes and reactions take place in the human body; hence, the pH of body fluids is the best indicator of disturbed health conditions. However, accurate and real-time diagnosis of the pH of body fluids is complicated because of limited commercially available pH sensors. Hence, we aimed to prepare a flexible, transparent, disposable, user-friendly, and economic strip-based solid-state pH sensor using palladium nanoparticles (PdNPs)/N-doped carbon (NC) composite material. The PdNPs/NC composite material was synthesized using wool keratin (WK) as a precursor. The in-situ prepared PdNPs played a key role in the controlled switching of protein structure to the N-doped carbon skeleton with π-π arrangement at the mesoscale level, which mimics the A-B type polymeric structure, and hence, highly susceptible to H+ ions. The optimized carbonization condition in the presence of PdNPs showed that the material obtained using a modified Ag/AgCl reference electrode had the highest pH sensitivity with excellent stability and durability. The optimized pH sensor showed high specificity and selectivity with a sensitivity of 55 mV/pH unit and a relative standard deviation of 0.79%. This study is the first to synthesize PdNPs using WK as a stabilizing and reducing agent. The applicability of the sensor was investigated for biological samples, namely saliva and gastric juices. The proposed protocol and material have implications in solid-state chemistry, where biological material will be the best choice for the synthesis of materials with anticipated performance.

Refining of Steel in Converters

In this chapter steelmaking processes and reactions are covered. A brief historical summary of important process developments is given and different types of converters are described. Then important chemical factors are detailed for the removal of the undesirable elements sulfur and phosphorus, and for the decarburization reactions. The refining of stainless steels in the argon oxygen decarburization (AOD) process is explained in detail, and a model for the AOD process is presented. Example simulations with the model illustrate how process changes may be introduced to improve productivity and reduce production costs.

Information Technologies of Digital Adaptive Medicine

The article provides a comprehensive description of information technologies of digital adaptive medicine. The emphasis is on the applicability to the development of specialized automated complexes, software models and systems for studying the adaptive capabilities of a person to environmental conditions. Requirements for information technologies to enhance these capabilities are formulated. The features of information technologies are reflected in relation to the implementation of applied systemic studies of life support, preservation of professional health and prolongation of human longevity. Six basic concepts of adaptive medicine with an emphasis on the features of the mathematical support for information processing are characterized, priorities for improving information technologies used in these concepts are determined. The information technologies used in the tasks of ensuring the professional performance of a person with an emphasis on the need to use adequate methods for diagnosing the state of a person at all stages of professional activity and the need to develop technologies for digital twins that adequately simulate the adaptation processes and reactions of the body in real conditions are considered. The characteristics of information technologies for personalized monitoring of health risks are given, which make it possible to objectify the effects of physical factors of the conditions of activity and to implement individual and collective informing of personnel about environmental hazards. The urgent need to standardize information processing methods in the development of information technologies for digital adaptive medicine in the interests of ensuring physiological adequacy and mathematical correctness of approaches to obtaining and processing information about a person's state is shown. It is concluded that the priorities for improving information technologies of digital adaptive medicine are associated with the implementation of the achievements of the fourth industrial revolution, including the concept of sociocyberphysical systems.

Oxygen Sensing of Pt/PEO-TiO2 in Humid Atmospheres at Moderate Temperatures

Here, we show that the presence of adsorbed water improves the oxygen-sensing properties of Pt/TiO2 at moderate temperatures. The studied interface is based on porous plasma electrolytic oxidized titanium (PEO-TiO2) covered with platinum clusters. The electrical resistance across Pt/PEO-TiO2 is explained by an electronic depletion layer. Oxygen adsorbates further increase the depletion by inducing extrinsic interface states, which are occupied by TiO2 conduction band electrons. The high oxygen partial pressure in ambient air substantially limits the electron transport across the interface. Our DC measurements at defined levels of humidity at 30 ∘C show that adsorbed water counteracts this shortcoming, allowing oxygen sensing at room conditions. In addition, response and recovery times from temporal oxygen exposure decrease with humidity. We attribute the effects to competing adsorption processes and reactions of water with adsorbed oxygen species and/or lattice oxygen, which involve electron re-injection to the TiO2 conduction band. Elevated temperatures up to 170 ∘C attenuate the effects, presumably due to the lower binding strength to the surface of molecular water compared with oxygen adsorbates.

Tissue Printing and Dual Excitation Flow Cytometry for Oxidative Stress—New Tools for Reactive Oxygen Species Research in Seed Biology

The intracellular homeostasis of reactive oxygen species (ROS) and especially of superoxide anion and hydrogen peroxide participate in signaling cascades which dictate developmental processes and reactions to stresses. ROS are also biological molecules that play important roles in seed dormancy and germination. Because of their rapid reactivity, short half-life and low concentration, ROS are difficult to measure directly with high accuracy and precision. In presented work tissue printing method with image analysis and dual excitation flow cytometry (FCM) were developed for rapid detection and localization of O2•− and H2O2 in different part of seed. Tissue printing and FCM detection of ROS showed that germination of wild oat seeds was associated with the accumulation of O2•− and H2O2 in embryo (coleorhiza, radicle and scutellum), aleurone layer and coat. To verify if printing and FCM signals were specified, the detection of O2•− and H2O2 in seeds incubated in presence of O2•− generation inhibitor (DPI) or H2O2 scavenger (CAT) were examined. All results were a high level of agreement among the level of ROS derived from presented procedures with the ones created from spectrophotometric measured data. In view of the data obtained, tissue printing with image analysis and FCM are recommended as a simple and fast methods, which could help researchers to detection and level determination of ROS in the external and inner parts of the seeds.

Electrical Discharge Machining of Oxide Nanocomposite: Nanomodification of Surface and Subsurface Layers

The work is devoted to the research of the changes that occur in the subsurface layer of the workpiece during electrical discharge machining of conductive nanocomposite based on alumina with the use of a brass tool. The nanocomposite of Al2O3 + 30% of TiC was electroerosively machined in a water and hydrocarbon oil. The process of electrical discharge machining is accompanied by oscillations that were registered by diagnostic means. The obtained surface of the samples was researched by the means of scanning electron microscopy and X-ray photoelectron spectroscopy. The observed surface and subsurface changes provide grounding for the conclusions on the nature of processes and reactions that occur between two electrodes and nanomodification of the obtained surfaces that can be an advantage for a series of applications.

Staging mental discursive processes and reactions: The construction of direct reported thought (DRT) in conversational storytelling

ABSTRACT This article approaches the construction of reported thought in everyday conversation by analysing instances of direct reported thought (DRT), taken from storytelling sequences. It is argued that DRT is used by narrators as a device to portray, in a dynamic sense, the ways in which they experience the story world in their mind, as discursive processes and reactions around an external event that clash with their expectations or initial perception of the situation. More specifically, the analysis shows that DRT is employed to stage a ‘first wrong thought’ (Jefferson 2004) that is shaped in a range of ways, as a process of worrying, deliberating, lamenting, and blaming or accusing someone in the situation, as well as shocked and indignant reactions that are constructed as exclamations and a process of reproaching and planning a future revenge action. (Direct reported thought, conversational storytelling, mental discursive processes, mental reactions, first wrong thought, silent shock, inner experience, direct reported speech)

Air Quality Analyses for Photochemical Smog Associated with Atmospheric Aerosol Particles and Ozone Precursors Using CMAQ and CAMx Modeling Systems

Pollution due to air quality deterioration is directly or indirectly connected to the phenomenon of biogeochemistry (i.e the scientific discipline that involves the study of the chemical, physical, geological, and biological processes and reactions that influence the composition of the natural environment) which in turn links to the human health. Human health and well-being, along with the well-being of animals, plants, and agricultural products, are solely dependent upon the quality of air we inhale. In response to the emission control threshold levels, prediction of how changes in emission levels could affect ambient air quality has been documented. The use of photochemical air quality models is becoming widely acceptable by various global regulatory agencies for the purpose of regulatory analyses and for the attainment exhibition by evaluating and assessing the effectiveness of control strategies. This review work tries to figure out the two most important and uncommon models namely; Comprehensive Air Quality Model with Extensions (CAMx) and Community Multiscale Air Quality (CMAQ) Modeling System. These modeling systems are used to predict, characterize, determine and simulate the photochemical air quality conditions. This paper gives a substantial detailed information of findings from related multidimensional studies carried out long ago and recently on photochemical smog analyses. Photochemical smog; causes and impacts on both the environment and living-being health were succinctly spelt out. Ozone formation and its different precursors; atmospheric aerosols; emission of biogenics as well as Ozone modeling phases were also discussed. The researcher still talks about the model formulations such as Zhang Model formulation; application and history of CMAQ and CAMx models respectively.