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Connection between complications (local and general) and lesions as well as prolonged irritation of biologically active zones by pins during external intraosseous osteosynthesis was detected and proved. Preventive measures of those complications were elaborated. Those preventive measures included insertion of pins beyond active zones after preliminary marking of active points (or canal). Observance of those rules provided decrease of the complication rate by 1.6 times when hinge-distraction devices were used and decrease by 1.8 times in application of reposition- fixation devices. When complications occurred the most radical treatment was either removal of pin that injured the biologically active point or reinsertion of that pin beyond the zone. Analysis of 770 cases (320 patients with hinge-distraction devices and 450 patients with reposition- fixation devices) was taken as a principle of that work.

The paper is devoted to topical problems of legal regulation of public relations in the field of alternative (renewable) energy sources in Russia and abroad. The paper shows the formation and development of the legal framework governing the investigated area of public relations in Russian and foreign law. The necessity of adopting a special legislative act in the Russian Federation dedicated to the civil regulation of public relations arising from the use of alternative (renewable) energy sources is substantiated.

Optical vortices have myriad applications in photonics. Very recently, promising concepts of spatiotemporal optical vortex (STOV) pulses based on the phase helicity in the space–time coordinates have attracted much attention owing to their donut shape. We elaborate on the molding of STOV under the transmission of femtosecond pulses through a thin epsilon-near-zero (ENZ) metamaterial slab based on a silver nanorod array in a dielectric host. At the heart of the proposed approach is the interference of the so-called main and additional optical waves enabled by strong optical nonlocality of these ENZ metamaterials, which leads to the appearance of phase singularities in transmission spectra. The cascaded metamaterial structure is proposed for high-order STOV generation.

Properties of one-dimensional spatially periodic metal structures formed by a dielectric lattice covered by gold and permalloy films are studied by optical and magnetooptical spectroscopy techniques. It is shown that these structures reveal the excitation of surface plasmon-polaritons, with the resonance frequency that can be controlled by the geometry of the experiment. The magnetooptical Kerr effect modulation, which is absent in the case of a nonprofiled gold/permalloy bifilm, is observed in the spectral vicinity of the plasmon resonance.

Based on the analytical and synthesis study of a wide range of published documentary sources, the article presents the authors' approach to the issue of self-restriction of state power. General theoretical aspects, historical and oriented to the current state of the problem were considered in order to analyze the self-limitation of the authority of the State in theory and in concrete reality. Methodologically, it is a study that uses in equal conditions the qualitative analysis of the systems and processes that emerge from the exercise of the authority of the State, with the hermeneutic reading of the legal doctrine that accounts for the matter. It is concluded that, in the considered context of the Russian Federation, the problem of the constant and continuous improvement of the system of separation of state power often seems to manifest itself satisfactorily. Theoretically, at first sight, once regulated, the corresponding system a priori acquires a constant and stable character, however, there is still a long way to go to achieve the foundation of a sustained dynamic of self-limitation and self-regulation of state power in in line with the principles of the rule of law.

The document presents the results of a comparative legal analysis dedicated to the constitutions of the European states regarding the identification of norms that guarantee the freedom of the social media in them. Methodologically the study was built on the basis of a dialectical approach to the dissemination of legal phenomena and processes using general scientific methods (systemic, logical, analysis and synthesis) and particular. By way of conclusion, all the evidence shows that, in the most common version, the constitutional regulation of guarantees is concise and includes only the recognition or guarantee of the freedom of the media together with the prohibition of censorship. In more detailed versions, prohibitive or regulatory rules may indicate specific types of liability, administrative procedures, etc. For federal states, it is typical to pay special attention to press matters within the scope of jurisdiction issues.

We demonstrate spatiotemporal optical vortices generation by transmission of laser pulses through epsilon-near-zero metamaterial based on metal nanorod array. The heart of proposed approach is phase singularities in transmittance of metamaterial caused by its optical nonlocality.

Compact planar photonic elements serving for efficient control over the polarization of light are of paramount importance in photonics. Here, we propose a design of a chiral periodic metasurface based on plasmonic nanodisks and nanorods arranged asymmetrically in a unit cell. Using the finite-difference time-domain analysis, we show that the collective lattice resonance harnessed by the diffraction coupling of the plasmonic unit cells is the heart of the revealed resonant 38% circular dichroism effect. The circular dichroism enhancement of the considered structure is improved using the deep-learning-assisted optimization of the metasurface design.

To discuss the feasibility, safety, and effectiveness of conventional laparoscopic partial nephrectomy combined with pyelolithotomy for patients with ipsilateral renal tumor and staghorn kidney stone.Retrospective multicentral comparative study. Group "Combo" was presented by patients with the mentioned combined pathology (n=15). Group "Standart" (n=69) formed from common patients who underwent standard lap partial nephrectomy for renal tumor in the absence of kidney stones. Perioperative factors and results were studied and compared. Video presentation of combined surgical technique is available at: https://youtu.be/fAfYJDvGzsU.Of all patients, no positive margins, no conversions to open surgery or nephrectomyany complications ClavienIII were detected. There were no any significant differences between the two groups except for OR time (150 [120; 210] vs 130 [100; 180] min; p=0,001). Differences between indexes of WIT (16,27+/-3,8 vs 15,9+/-4,5 min; p=0,107), EBL (200 [150; 300] vs 200 [150; 300] cc; p=0,981), length of stay (7 [6;9] vs 8[6;9] days; p=0,611), intraop complications (0,00 vs 4,3%; p=0,411) and values of postop Clavien III rate (0,00 vs 4,3%; p=0,411) for "Combo""Standart" respectively were comparable as well as oncological outcomes. Stone-free rate for combined procedures reached 93,3%.conventional laparoscopic partial nephrectomy combined with pyelolithotomy for patients with ipsilateral renal tumor and staghorn kidney stone is safe and efficient alternative to 2-step treatment of this rare disease.

The ability to manipulate the frequency of light is a cornerstone of a wide range of applications in photonics expanding spectral ranges of the light sources. To boost the second harmonic generation efficiency, intense efforts toward exploiting artificial microstructures for frequency doubling were carried out. The sought-after approach of utilizing photonic crystals is inspired by their unusual light dispersion. In such structures, the dynamics of the field of femtosecond laser pulses is of paramount importance for frequency conversion. In this work, we investigate the phase-matched second harmonic generation under the effect of diffraction-induced femtosecond laser pulse splitting in one-dimensional photonic crystals at the Bragg diffraction in the Laue geometry. We demonstrate that the interaction of the two pulses at the fundamental frequency that appears in photonic crystals through the dynamical light diffraction leads to a nonmonotonic dependence of the frequency up-conversion efficiency with respect to the laser pulse duration, thus allowing to increase the second harmonic power by tuning the pulse duration.

Purpose of the study: The aim of this article is to analyze the attitude of students to ethical consumption as a new environmental practice; to explore current research on ethical consumption. Methodology: The leading methods for the study of this problem are the methods of questioning and testing, allowing to make a qualitative analysis of the students' attitude to the new environmental practice – ethical consumption and contributing to a more detailed identification of such issues as: knowledge of students about ethical consumption; students' attitude to separate waste disposal; students' attitude to the use of environmental packaging products; identification of students' practices of secondary consumption. Results: The article deals with the theoretical and methodological foundations of the analysis of students' attitudes to ethical consumption as a new environmental practice. It is established that the level of students' awareness of ethical consumption is low. The proportion of informed students among social and humanities specialties is twice more than high as students of technical specialties. It is revealed that more than a third of respondents do not know about the production of environmentally friendly goods. Almost all students are aware of the separate disposal of garbage and believe that it is necessary to install the appropriate bins. More than half of students are ready to sort garbage in the presence of such containers, and the readiness of humanitarians is 1.5 times higher than that of students of technical specialties. The main reasons why respondents would not buy goods in eco-friendly packaging are the lack of funds and the lack of sense for students. The majority of students believe the practice of secondary consumption to be popular one. Applications of this study: The data obtained in the work can be used in environmental psychology, social psychology, pedagogy, the psychology of education, age psychology, sociology, as well as for further theoretical development of this issue. Novelty/Originality of this study: The originality of this article lies in the analysis of the social phenomenon of ethical consumption, which implies that only purchase and consumption of those goods, the production of which does not cause great harm to the environment, those goods in the production of which are not infringed the rights of the worker and moreover child labor is not used, and most importantly the recycling of waste after consumption of the product will not harm nature is ethical one.

Introduction Despite the twenty-year history of laparoscopic ileal ureteral substitution, the literature is lacking studies reporting its outcomes, and those few are mainly case reports. Besides, they usually describe surgery from combined access, when the ileal segment resection and ileo-ileal anastomosis are performed from mini-laparotomy, and the remaining stages are done endoscopically. Aim To conduct a multicenter retrospective analysis of our series of patients undergoing laparoscopic ileal ureteral substitution using only endoscopic access. Material and methods From 2010 to 2017, 48 ureters were replaced completely laparoscopically in 40 patients. Of them, 33 patients underwent total ureteric replacement, and the others had a subtotal ileal ureteral substitution. Video describing the operation technique is available on https://youtu.be/IeA60pSiUBE. Results The mean operating time was 335 minutes, and the estimated blood loss was 221 ml. Intraoperative complications (7.5%) were resolved during surgery. No patients required conversion to open surgery. There was no mortality. Postoperative Clavien III complications were observed in 7.5% of patients. The mean length of hospital day was 13.5 days. Functional results were followed from 6 months to 7 years. Conclusions The presented material is the largest available in the literature, and the results, including long-term functional outcomes, demonstrate the efficacy and safety of laparoscopic technologies in the treatment of extensive strictures and obliterations of the ureter.

Wealth of fascinating phenomena provided by artificial photonic structures sparks extensive research efforts in the studies of metamaterials, a special and perspective class of them being the hyperbolic metamaterials (HMMs). Strong HMMs optical anisotropy attained by the combination of metal and dielectric constituents underpins unusual hyperbolic dispersion of light in these artificial media, which marvels plethora of far-reaching applications in photonics. However the dynamics of ultrashort optical pulses in HMMs remains almost unexplored. In this work we experimentally investigate the interaction of femtosecond laser pulses with metal-nanorod based HMMs exhibiting the epsilon-near-zero (ENZ) spectral point, when extraordinary dielectric permittivity goes to zero yielding transition between topologically distinct elliptic and hyperbolic light HMM dispersion. We demonstrate a pronounced superluminal and slow propagation of laser pulses in the HMM, with the transition between these regimes and resonant character of these phenomena in the spectral vicinity of the ENZ point. We put forward a theoretical model of the superluminality and slow light, which leverages unusual case of laser pulse with spectral components in elliptic and hyperbolic dispersion at once. We believe our findings bring to life superior applications for future linear and nonlinear ultrafast photonics of HMMs harnessing of revealed exotic dynamics of optical field in these media.

The article deals with the issues of conciliation in determining the interests of States in international law. This procedure involves two levels. The first level is reaching assent on the content of the rule. The second level is the recognition by States of such a rule as mandatory. By agreeing to the rule, the State undertakes to comply with this international document.

Artificial hyperbolic metamaterials (HMM) are perspective for the nonlinear optical applications, their exciting functionality being due to the hyperbolic dispersion induced by a strong shape anisotropy. Here we study the second harmonic generation (SHG) in HMM formed by arrays of silver nanorods in anodic alumina. In the hyperbolic dispersion regime, giant SHG is observed associated with the fulfillment of the phase-matching conditions supported by the epsilon-near-pole resonance at the SHG wavelength, and an increase in the pump field in the epsilon-near-zero (ENZ) spectral range. We predict a strong increase in the SHG efficiency for metamaterials with the ENZ resonance at the second harmonic frequency.

Structuring of a medium on the wavelength and subwavelength scales significantly enriches its interaction with light leading to new optical effects. As a result, it fuels the interest in planar artificial structures like photonic crystals, metasurfaces and plasmonic crystals, which have found tremendous success in light manipulation and applications in sensing, routing, light localization, enhancement of the nonlinear effects. The deep insight into optical phenomena in artificial structures requires necessarily numerical simulations. For periodic structures such as photonic crystals and diffraction gratings, numerical methods like finite-difference time-domain method (FDTD) and rigorous coupled-wave analysis (RCWA) are widely used. These methods have definite drawbacks, as the FDTD requires large computer memory to store the field values in the nodes of a 3D mesh, and high computational effort for the time simulation; the RCWA demands extra labor for the accurate treatment of a grating made of metal or anisotropic materials. Because the optical effects in highly anisotropic metal-based artificial structures like hypercrystals are of practical interest, we have proposed hybrid finite-difference frequency-domain (FDFD) approach for the calculation of light diffraction in such periodic structures. The improvement is achieved by handling the direct values instead of Fourier series, which is the core of the RCWA. Using this approach, we predict the excitation of the Dyakonov plasmons in hypercrystal formed by trenches in hyperbolic metamaterials.

Micro- and nanostructuring of optical media is the cornerstone for a wide range of applications in optics. Artificial structures significantly enrich the interaction of light with dielectrics and metals and are harnessed to reveal exciting optical effects. Recently hypercrystals were proposed as intriguing class of periodic structures bringing together hyperbolic dispersion law of hyperbolic metamaterials and the Bragg diffraction. In this work we proposed the finite-difference frequency-domain method for modeling of light diffraction in these highly anisotropic structures. The method is suitable for one- and two-dimensional gratings as well as multilayer gratings made of anisotropic materials. Developed approach gives advantages over the finite-difference time-domain method (FDTD) and rigorous-coupled mode analysis (RCWA) widely used for calculation of light diffraction in gratings. Proposed method eliminates evaluation of time dynamics and discretization of whole volume of a structure as the FDTD does. Instead, Yee’s mesh of the cross section of the unit cell of grating is involved. As well information about the Bloch modes of the field inside the structure inaccessible directly for the FDTD is obtained. We used of values of electromagnetic field in mesh nodes instead Fourier series applied in the RCWA to overcome difficulties of the RCWA for high contrast and highly anisotropic structures as hypercrystals. Using the proposed numerical approach, we demonstrate that interface of one-dimensional hypercrystals formed by ridges of hyperbolic metamaterial can support excitation of the Dyakonov plasmons, which merge the Dyakonov waves supported by the interface of birefringent crystal and surface plasmon polaritons in metals.

Resonant enhancement of light power emitted by dipoles located inside silver nanorod-based hyperbolic metamaterial near its interface is revealed at epsilon-near-zero regime of metamaterial. Enhancement is accompanied by peculiar radiation pattern.

The spread of digital innovation in the world began in the 1960s. and the first stage came down to the automation of technologies and processes. The next stage came in the mid-90s. and is associated with the global spread of the Internet and mobile communications, the extensive penetration of innovation into society. The current stage of innovatiоndriven development is characterized by the expansion of Internet access of millions of consumers, the integration of wide range of digital services, products, systems into the digital socio-ecological and economic system. The ongoing revolutionary changes deserve additional understanding and analysis, since they give to many countries such impetus for rapid growth that they change the very paradigm of development, and force them to measure and evaluate the life quality in a new way. In the context of problems covered in this article, it is especially relevant to conduct a causal analysis of digital transformation against the background of global transformations of the world economy.In the process of analyzing innovation as a tool for the development of public production, the authors identified the drivers of digital economy, determined their role at the present stage, and showed their distinctive aspects and features.

Significance We adapted natural language processing to the biological literature and demonstrated end-to-end automated knowledge discovery by exploring subtle word connections. General text mining scanned 21 million publication abstracts and selected a reliable 130,000 from which hypothesis generation algorithms predicted kinases not known to phosphorylate p53, but likely to do so. Six of these p53 kinase candidates passed experimental validation. Among them NEK2 was examined in depth and shown to repress p53 and promote cell division. This work demonstrates the possibility of integrating a vast corpora of written knowledge to compute valuable hypotheses that will often test true and fuel discovery., Scientific progress depends on formulating testable hypotheses informed by the literature. In many domains, however, this model is strained because the number of research papers exceeds human readability. Here, we developed computational assistance to analyze the biomedical literature by reading PubMed abstracts to suggest new hypotheses. The approach was tested experimentally on the tumor suppressor p53 by ranking its most likely kinases, based on all available abstracts. Many of the best-ranked kinases were found to bind and phosphorylate p53 (P value = 0.005), suggesting six likely p53 kinases so far. One of these, NEK2, was studied in detail. A known mitosis promoter, NEK2 was shown to phosphorylate p53 at Ser315 in vitro and in vivo and to functionally inhibit p53. These bona fide validations of text-based predictions of p53 phosphorylation, and the discovery of an inhibitory p53 kinase of pharmaceutical interest, suggest that automated reasoning using a large body of literature can generate valuable molecular hypotheses and has the potential to accelerate scientific discovery.

A one-dimensional combined plasmonic–photonic system tailored for the enhancement of nonlinear optical effects is proposed and implemented. In this structure, a layer of silver plasmonic nanoparticles is placed in the cavity region of a photonic-crystal microcavity made of porous silicon. A multifold increase in an optical second harmonic generation signal in comparison to the structure without plasmonic nanoparticles is demonstrated.

Internal drainage of the upper urinary tract by stenting is a common urological procedure. The use of stenting in modern urological practice is on the rise due to widespread adoption of modern endourological, laparoscopic, percutaneous and high-tech robotic interventions. The presence of a stent in the patients body may cause stent-related symptoms and negatively affect the quality of life, resulting in additional outpatient visits and hospitalizations. The review provides an analysis of the causes, diagnostic evaluation, prevention and treatment of stent-related symptoms. The authors describe the management options including -blockers, anticholinergics, and their combinations.

A complete study of thermodynamic properties of 1,4-benzoquinones in the condensed and gaseous phases was carried out using experimental techniques and theoretical approaches. Enthalpies of combustion and formation of 2-methyl-1,4-benzoquinone were evaluated using combustion calorimetry. The transpiration method was utilized to determine the temperature dependence of the vapor pressures of 1,4-benzoquinone and 2-methyl-1,4-benzoquinone for the sublimation and vaporization enthalpies calculation. The group additivity scheme was used independently for verification of sublimation enthalpy of 2-methyl-1,4-benzoquinone. For this procedure the enthalpy of solution of 2-methyl-1,4-benzoquinone in benzene was measured at 298.15 K. The experimental values obtained were combined with published data and organized to obtain a reliable set of the experimental enthalpies of formation and enthalpies of phase transition of compounds. The methods of quantum chemistry and statistical physics based on the “rigid rotator–anh...

Chiro-optical signals from chiral molecules/structures are inherently weak. In particular, enhancing the circular-dichroism (CD) effect (different absorption of left or right circularly polarized light) in the non-linear optical (NLO) signal from chiral molecular materials is challenging and imperative since it is advantageous in various areas, from biomedical sciences to miniaturized photonic devices. Here we suggest and realize for the first time an approach to enhance the CD effect taking advantage of the NLO effects resonantly enhanced in the nonlinear chiral organic micro-resonators. These R- and S-type resonators in the form of micro-spheres are prepared by the self-assembly technique from the corresponding axially chiral enantiomeric molecules, namely R- and S-4-[2,2′-diethoxy-6′-(4-formylphenyl)-[1,1′-binaphthalen]-6-yl]benzaldehyde in CHCl3/MeOH mixtures. Each enantiomeric micro-sphere, upon optical pumping, acts as a whispering gallery mode (WGM) resonator as the photo-luminescence (PL) is excited in a single- or in a two-photon regime. We show that the NLO-CD effect and the two-photon absorption (TPA) in the case of micro-spheres are at least twice as high as compared to a continuous film of the same effective thickness. This is due to pronounced field localization effects in micro-spheres with high Q-factor, which increases the photon residence time (τP) in a chiral medium and thus strengthens the light–matter interaction. Finite-difference time-domain (FDTD) numerical calculations confirm a strong light localization near the boundary of the micro-spheres.

The key component of parallel computing efficiency is the structure of data exchange between computing nodes. It is necessary to reduce the latency of data exchange to improve the efficiency of parallel computing. A B+2R algorithm for overlapping delays in the data exchange was offered for this purpose. Existing works do not offer a method for selecting the additionally transmitted data layer count R. We introduce the models of all systems affecting the parallel calculation time. It makes possible to apply the analytical optimization. We introduce a data transmission network and a parallel computing application models. We consider the cell calculation time is a constant value. The cell calculation time depends on the specific calculation parameters. We introduce an estimate of the computation time. Computation time depends on the additionally transmitted data layers count. Further we introduce the derivative of computation time equation. We use lowest positive real roots of the cubic equation. It’s possible that the final cubic equation hasn’t real positive roots. It’s mean that local structured grid calculation time is much bigger than network latency. In that case, it’s not recommended to use latency hiding schemes. Otherwise we recommend to use R equal to 1. Purpose of out research is to find optimal R. Optimal R value should lead to a calculation time equation minimum. The method proposed in the paper correspond to experimental result. Designed analytical model for B+2R algorithm makes possible to select optimal R value, which leads to the best calculation speedup.

We present experimental and theoretical studies of the anomalous high transmission of light (the Borrmann effect) under the Laue diffraction in a one-dimensional photonic crystal (PhC) characterized by spatial modulation of both refractive index and absorption. We show that a strong modulation of the refractive index along with the large PhC period provide new features of the Borrmann effect as compared to the well-known x-ray Borrmann effect in crystals appearing in PhC wavelength-angular transmission spectra. Namely, the maximal transmission is attained at the Bragg angles of incidence and corresponds alternatively to even or odd orders of the Bragg angles depending on the light wavelength. Second, a dramatic decrease of the angular width of the high transmission areas in the spectrum appear near the diabolic points. According to our description, this effect can be treated as a result of the topological phase transition accompanied by exchange of the parity of spatial distribution of the electromagnetic field of the two eigenmodes experiencing degeneracy. We demonstrate that these peculiarities are inherent to the PhC with the optical losses located in layers with higher refractive index, and disappear if the losses are specific for the PhC layers with lower refractive index. The suggested underlying mechanism involves the contribution of the waveguide PhC modes to the PhC transmission spectra.

Due to the large-scale reforming of the Russian economy, the scope of transformations of the regional level does not lose relevance for many years. As generalization of results of domestic and foreign methods of research of transformations in the economy showed, application of institutional approach in this direction is limited to difficulties of terminological character. For their overcoming, the concept of institutional conditions is specified in the paper. Value of these conditions for economic growth and development of the region is shown. In the paper, the special attention is paid to a problem of forming the system of indicators for operational use of institutional approach in the economy of a region. The system of indicators of institutional transformations described in the paper is intended for operational use of quantitative estimates in the regional economy. The system of indicators is made by two complementary blocks – socio-economic and institutional. Indicators of the socio-economic block adumbrate about the economy of a region, about its potentials, illustrate a region place in national economy. The information base for assessing the existing conditions in the regional economy for the implementation of available opportunities is the institutional block, which contains indicators of the quality and efficiency of institutions. The use of the offered system of indicators will allow not only receiving the results having the high practical importance in the field of regional economic management, but also using them at further creation of macroeconomic models.

Flourish of optics of hyperbolic metamaterials (HMMs) is stimulated by their exotic optical properties. Here, we demonstrate resonant changes of the group retardation and superluminal-like propagation of femtosecond laser pulses in nanorod-based HMMs in the vicinity of epsilon-near-zero spectral point responsible for the transition between topologically distinct elliptic and hyperbolic light dispersions. Resonant dynamics of ultrashort pulses appears in a unique case when their spectral components are in both dispersion regimes simultaneously. Our findings suggest HMMs as a powerful platform for future ultrafast photonics and are pivotal for growing nonlinear optics of hyperbolic media.

In this work a simple method for calculation of solvation enthalpies of polyaromatic hydrocarbons (PAHs) in various solvents at 298.15 K was proposed. According to this method the enthalpy of solvation of any polyaromatic hydrocarbon in a particular solvent can be calculated on the basis of the general formula of the compound, the solvation enthalpy of benzene in the same solvent and parameter related to the contribution of hydrogen atom into solvation enthalpy. The validity of the proposed method was confirmed by the comparison of calculated and experimentally measured values of solvation enthalpies of PAHs in benzene, tetrahydrofuran and acetonitrile. This method was used for determination of the sublimation enthalpy of PAHs at 298.15 K based on the general relationship between the enthalpy of sublimation/vaporization of the compound of interest and its enthalpies of solution and solvation in the same solvent at 298.15 K. Enthalpies of solution at infinite dilution of several PAHs were measured in acetonitrile, benzene and tetrahydrofuran at 298.15 K. It was shown that solution enthalpies of PAHs in benzene at 298.15 K are approximately equal to their fusion enthalpies at the melting temperature. Solvation enthalpies of 15 PAHs at 298.15 K calculated according to the proposed method together with corresponding fusion enthalpy values (at the melting temperature) were used to calculate the sublimation enthalpy values at 298.15 K. Comparison of the obtained results with recommended values of sublimation enthalpy shows that fusion enthalpies at the melting temperature can be used instead of the solution enthalpies in benzene at 298.15 K for calculation of the sublimation enthalpy at 298.15 K.

In this work a new method for determination of vaporization/sublimation enthalpies of aromatic compounds directly at T = 298.15 K was developed. This method is based on the general relationship between vaporization/sublimation enthalpy and enthalpies of solution and solvation of the studied compound in any solvent. According to this method the procedure for determination of vaporization (liquids) or sublimation (solids) enthalpy includes measurement of the solution enthalpy of the compound in a selected solvent and calculation of the solvation enthalpy for this system. A group-additivity scheme for calculation of solvation enthalpies is proposed. The solvation enthalpy of compound is estimated from the solvation enthalpy of parent aromatic or heteroaromatic compound and contributions of the substituent groups. Limiting solution enthalpies of 34 aromatic compounds (substituted benzenes, naphthalenes, biphenyls, pyrene, anthracene and pyridines) in carbon tetrachloride, benzene, acetonitrile and N,N-dimethylformamide were measured in the present work at 298.15 K. Vaporization/sublimation enthalpies of 78 aromatic and heteroaromatic compounds were determined directly at 298.15 K using experimentally measured solution enthalpies and predicted values of solvation enthalpies. The results are in good agreement with available literature data.

The enthalpies of solution, solvation and vaporization/sublimation are interrelated values combined in the simplest thermodynamic circle. Hence, experimental determination of vaporization/sublimation enthalpy can be substituted by experimentally simpler determination of solution enthalpy when solvation enthalpy is known. Previously it was found that solvation enthalpies of a wide range of unbranched aliphatic and aromatic solutes in saturated hydrocarbons are in good linear correlation with their molar refraction values. This allows to estimate the vaporization/sublimation enthalpy of any unbranched organic compound from its solution enthalpy in saturated hydrocarbon and molar refraction. In the present work this approach was modified for determination of vaporization/sublimation enthalpy of branched-chain alkyl aromatic and aliphatic compounds. Group contributions to the enthalpy of solvation due to the branching of carbon chain were evaluated. Enthalpies of solution at infinite dilution of 18 branched-chain aliphatic and alkyl aromatic compounds were measured at T = 298.15 K. Vaporization/sublimation enthalpies for 35 branched aliphatic and alkyl aromatic compounds were determined by using modified solution calorimetry approach. These values are in good agreement with available literature data on vaporization/sublimation enthalpies obtained by conventional methods.