A Promising Thermodynamic Study of Hole Transport Materials to Develop Solar Cells: 1,3-Bis(N-carbazolyl)benzene and 1,4-Bis(diphenylamino)benzene

The thermochemical study of the 1,3-bis(N-carbazolyl)benzene (NCB) and 1,4-bis(diphenylamino)benzene (DAB) involved the combination of combustion calorimetric (CC) and thermogravimetric techniques. The molar heat capacities over the temperature range of (274.15 to 332.15) K, as well as the melting temperatures and enthalpies of fusion were measured for both compounds by differential scanning calorimetry (DSC). The standard molar enthalpies of formation in the crystalline phase were calculated from the values of combustion energy, which in turn were measured using a semi-micro combustion calorimeter. From the thermogravimetric analysis (TGA), the rate of mass loss as a function of the temperature was measured, which was then correlated with Langmuir’s equation to derive the vaporization enthalpies for both compounds. From the combination of experimental thermodynamic parameters, it was possible to derive the enthalpy of formation in the gaseous state of each of the title compounds. This parameter was also estimated from computational studies using the G3MP2B3 composite method. To prove the identity of the compounds, the 1H and 13C spectra were determined by nuclear magnetic resonance (NMR), and the Raman spectra of the study compounds of this work were obtained.

Processing of Waste from Enrichment with the Production of Cement Clinker and the Extraction of Zinc

This paper presents studies on the processing of enrichment tailings as a component of a raw mixture in order to obtain cement clinker, with simultaneous distillation of zinc. Thermodynamic studies were carried out in the temperature range of 600–1600 °C using the software application “HSC Chemistry 6” developed by the metallurgical company Outokumpu (Finland). As a result of the conducted studies, we found that zinc contributes to the intensification of mineral formation of cement clinker. In particular, it was found that the formation of belite is possible in the temperature range from 990.7 to 1500 °C with Gibbs energy values of −0.01 and −323.8 kJ (which is better than the standard process by −11.4 kJ), respectively; the formation of alite is possible in the temperature range from 982.9 to 1500 °C with Gibbs energy values of −0.05 and −402.1 kJ (better than the standard process by −11.4 kJ), respectively; the formation of tricalcium aluminate is thermodynamically possible in the temperature range from 600 °C at ΔGTo = −893.8 kJ to 1500 °C at ΔGTo = −1899.3 kJ (better than the standard process by −1570.1 kJ), respectively; and the formation of four calcium aluminoferrite is possible in the temperature range from 600 °C at ΔGTo = −898.9 kJ to 1500 °C at ΔGTo = −1959.3 kJ (better than the standard process by −1570.2 kJ), respectively, with simultaneous distillation of zinc into a gaseous state for its further capture.

Dependence of concentration of radon on environmental parameters

Radon (222Ra) is a colourless and odourless natural radioactive element in gaseous state. The concentration of radon in the air is usually low, but it can be very high inside of a living space, because of its possibility to penetrate from a foundation soil over a basement into a building itself. People are daily exposed to a certain concentration of radon that is found in soil, water, air and food. This paper shows a correlation analysis of environmental parameters by using the model of multiple regressions. It defines certain statistical relations between environmental parameters such as temperature, humidity, and atmospheric pressure with measured values of radon concentrations. Measurements were carried out at several locations in various residential buildings in north-western Croatia. The results indicated that individual environmental parameters and radon concentration at individual locations were connected. For example, at one location the concentration of radon was decreasing if atmospheric pressure was increasing. Measurements at another location indicated that the concentration of radon was increasing if air humidity was increasing. Due to large number of different parameters affecting the concentration of radon in residential buildings, a satisfactory statistical model to predict the concentration of radon with environmental parameters is not easy to achieve since it was observed variability of radon concentrations with environmental parameters within different local sites. It is necessary to consider a longer period to determine with certainty a mathematical model that would give the most accurate prediction of radon concentration dependence on environmental parameters which can affect human health and quality of life.

Theoretical Estimate of Cooling Time of a Liquid Hydrogen Tank during Structural Tests

Russian enterprises continue developing rocket and space vehicles based on cryogenic propellants, i.e. liquid hydrogen, oxygen, and methane. Hence, the issues of fuel tanks’ thermal strength are increasingly important. During structural tests, the operating temperatures of the test object should be simulated, since the temperature condition affects the strength and rigidity of the structure. Consequently, during ground-based experimental tests, hydrogen tanks must be cooled down to 20 K, the boiling point of hydrogen. JSC TsNIIMash is developing a helium system capable of cooling large-sized structures to a temperature of 20 K. Helium can be used in a gaseous state to cool down the structure, since the boiling point of helium, 4 K, is lower than the boiling point of hydrogen. Until now, the tanks were cooled only by filling with liquid nitrogen, therefore the temperature state of the tanks during the tests was simulated only for this case. In order to determine the applicability of the method developed, the cooling time of large-sized containers was estimated by cooling a hydrogen tank, which by its dimensions is typical for an advanced medium-class second stage launcher, to 20 K by gaseous helium.

Hydrogen Sulfide: A Robust Combatant against Abiotic Stresses in Plants

Hydrogen sulfide (H2S) is predominantly considered as a gaseous transmitter or signaling molecule in plants. It has been known as a crucial player during various plant cellular and physiological processes and has been gaining unprecedented attention from researchers since decades. They regulate growth and plethora of plant developmental processes such as germination, senescence, defense, and maturation in plants. Owing to its gaseous state, they are effectively diffused towards different parts of the cell to counterbalance the antioxidant pools as well as providing sulfur to cells. H2S participates actively during abiotic stresses and enhances plant tolerance towards adverse conditions by regulation of the antioxidative defense system, oxidative stress signaling, metal transport, Na+/K+ homeostasis, etc. They also maintain H2S-Cys-cycle during abiotic stressed conditions followed by post-translational modifications of cysteine residues. Besides their role during abiotic stresses, crosstalk of H2S with other biomolecules such as NO and phytohormones (abscisic acid, salicylic acid, melatonin, ethylene, etc.) have also been explored in plant signaling. These processes also mediate protein post-translational modifications of cysteine residues. We have mainly highlighted all these biological functions along with proposing novel relevant issues that are required to be addressed further in the near future. Moreover, we have also proposed the possible mechanisms of H2S actions in mediating redox-dependent mechanisms in plant physiology.

COMPARATIVE CHARACTERISTICS OF COATINGS WITH SiO AND GeO ON LEUCOSAPPHIRE

The reasons for the sharp difference in the adhesion of multilayer coatings containing SiO or GeO together with Ge on a leucosapphire (Al2O3) plate have been established. It should be mentioned that Silicon(II) and Germanium(II) oxides are quite stable in the gaseous state and, contrary, are metastable in condensed state; at high temperature they disproportionate into ultra-dispersed composites of amorphous nature. A comparison is made of the surface properties of ultramicroscopic droplets formed on solid surfaces – a substrate or the previous layer – upon condensation of SiO, GeO, or Ge vapors on leucosapphire. A qualitative assessment of the ratio of the corresponding contact angles of wetting by the indicated melts, formed at the first moment of contact, has been carried out. In assessing the surface tension of SiO and GeO melts (or Si – SiO2 and Ge – GeO2 composites), we proceeded from the corresponding values for SiO2 and GeO2, which are 296 and 248 mJ/m2 near the crystallization temperatures. On this basis, it was established that the smallest value of the contact angle, and hence the best wetting, is observed for the GeO melt (somewhat less for the SiO melt) on the solid surface of Al2O3 or Ge; the solid surface of SiO or GeO (especially, the first of them) with molten germanium should be much weaker wetted. Hence, it follows that thin-film multilayer coatings obtained from Ge and GeO on a leucosapphire substrate should have a significantly higher climatic resistance due to higher adhesion compared to multilayer coatings from SiO and Ge. Indeed, a multilayer coating containing SiO on a leucosapphire substrate with a large surface can withstand storage in air for no more than 2–3 months and begins to peel off; at the same time, the GeO coating remains intact after 4 years of storage. Thus, the GeO film-forming material is a promising one for use in multilayer coatings such as cut-off filters in interference optics of the near and mid-IR spectral ranges.

Study on the Influence of Nanosilica Sol on the Hydration Process of Different Kinds of Cement and Mortar Properties

Compared with nanosilica collected in a gaseous state, nanosilica sol has great economic value and application significance for improving the performance of concrete and mortar. In this study, the influence of nanosilica sol on the hydration process of different kinds of cement is studied by means of hydration heat analysis,X-ray diffraction analysis(XRD)and other methods, and the properties of mortar such as setting time, mechanical properties and porosity are also studied to characterize the influence of nanosilica sol on the macroscopic properties of mortar. The experimental results show that nanosilica sol can accelerate the hydration rate of two kinds of cement and promote the hydration reaction degree of cement, and this promotion effect increases with the increase in nanosilica sol content. At the same time, nanosilica sol can significantly shorten the setting time of the two kinds of cement, and it is more obvious with the increase in content. Excessive content of nanosilica sol will adversely affect the permeability resistance of mortar. It may be caused by the weak interval formed by nanosilica particle clusters in the mortar matrix, which can be supported by the mortar pore structure distribution test. At the same time, the influence of nanosilica sol on the hydration of the two kinds of cement is different, and the compressive strength of HBSAC cement mortar increases first and then decreases after adding nanosilica sol; However, the compressive strength of P·O 42.5 cement mortar increases gradually after adding nanometer silica sol. This shows that nanosilica sol does not effectively promote the hydration of β-C2S in high belite sulfoaluminate cement (HBSAC) mortar. Based on the above experimental results, it can be concluded that when the content of nanosilica sol is about 1%, it has the best promotion effect on the hydration of the two kinds of cement and the performance of mortar.

Solid-state electronegativity of atoms: new approaches

Electronegativities (EN) of 65 elements (H to Bi, except lanthanides and noble gases, plus U and Th) in solids were derived from various observed parameters, namely, bond energies in solids, structural geometry, work functions and force constants, yielding a set of internally consistent values. The solid-state electronegativities are generally lower than the conventional (`molecular') values, due to different coordination numbers and electronic structure in a solid versus a molecule; the decrease is stronger for metals than for non-metals, hence binary compounds have a wider EN difference and higher bond polarity (ionicity) in the solid than in the molecular (gaseous) state. Under high pressure, the ENs of metals increase and those of non-metals decrease, the binary solid becomes less polar and can ultimately dissociate into elements.

The Embodiment of Light

As children one of the first epiphanies we learn, when we go to school, are the three States of Aggregations of water. The amazing effect that ice, water and steam are all the same. Just water in three different states. This concept version claims that like water, there are three different States of Aggregations of Light. Compared to water: Like ice is the solid state of water, Light is the solid State of Light. Matter is the First State of Light, bounded by the Electromagnetic Force and Gravity (which is the secondary effect of confined Light). Like water is the liquid state, the free light we already know from the day we were born is the second State of Aggregation of Light. Free Light is the Second State of Light of light and can travel freely through space. cannot travel through matter because light has been bounded and confined by the electromagnetic force. Like steam is the gaseous state of water, the Third State of Light is the unknown State of Light. The state in which light can travel feely through matter and is invisible for our physical world. The light which does not interact with our measurements and physical experiments because this state of light is free of the confining electromagnetic force. The light which travels with the infinite speed because this is the light without inertia. This invisible world of the Third State of Light has been called the Spiritual World. The world of the Soul. The world of feelings. The world of thoughts. The world from which we really see and hear and feel and experience. The world where we were before we were born and the same world where we will be after we pass away. This is the world excluded till now by science.

Sleeping under Trees at Night is not Healthful; Sleeping during the Day is Healthful – Forming CO (CO2) and their Dissociation

<p>A carbon atom keeps a non-preserved behavior because of converting into another state. This character makes it adjacently coincide with oxygen atom when it is in the gaseous state. A field variation develops for the day and night. On having the suitable interaction of photons with leaves in daytime, pieces of arc-shaped energy are made. To get the ground surface, the pieces of arc-shaped energy become empty due to the highest value of gravity at ground level. On sunset, empty pieces of arc-shaped energy fill with the force having the levitating nature, so they start flying to gather under the tree roof. Such filled force pieces develop the affinity in adjacently coinciding atoms of gaseous carbon and oxygen. At certain behavior of force, the downward ends of filled force pieces enter into the suitable unfilled states of gaseous atoms adhering the binding of C - O or O - C - O. So, a large number of CO and CO₂ molecules develops under the tree roof, which is not good for breathing during the night. In the morning, an arc-shaped energy breaks the affinity in CO and CO₂ molecules by giving back the filled force. As a result, the molecules dissociate into the atoms. To get the ground surface, the dissociated gaseous carbon atoms converted into graphitic carbon before noon. So, the oxygen concentration during sunshine increases under the tree roof thereby improving the breathing level of the one resting in the shadow. So, COVID-19 patients can take advantage of the raised level of oxygen. But, it is not useful to rest under the tree roofs at night. How the plantation of trees can be essential for a sustainable environment helps build remarkable procedures and is being discussed here. </p>