Non-conventional Conditions Research Articles

An integrative sustainability assessment of the Tsuji–Trost reaction simulating allylic amination under non-conventional (vs. conventional) conditions

The article describes sustainability aspects of the Tsuji-Trost reaction in terms of productivity (reactivity-coupled utility), side reaction assessment, and environmental impact of allylic precursors.

EFFECT OF THE CONVECTIVE BOUNDARY LAYER ON RADIOSONDE FLIGHT PATH OVER BAGHDAD AIRPORT STATION (CASE STUDY)

This research was aimed to investigate effect of the convection conditions resulted from surface heating at different weather condition on movement track of radiosonde. Data used in this study divided to surface local weather from Baghdad airport station and reanalysis weather surface data from European center medium weather forecast (ECMWF) that contain also advance parameter parameters such as sensible heat flux and boundary layer height and other, all have large accurate spatial distribution inside and outside Baghdad province. Third type data from radiosonde used to observed atmospheric upper layer through selected days from winter season (January month) and summer season (July month) all at time 12AM. Software installed in radiosonde used to recoded wind speed, temperature and other parameter such as global position system (GPS) all plotted and represented by ArcGISpro. Results show different in the radiosone path at convection and nonconventional conditions. Convection constraint movement of radiosonde path (wind speed profiles very low don’t reach to 30m/s in upper layer, this is opposite to nonconventional case, it reach to more than 65m/s) because turbulent and random in different directions, this case is opposite to the nonconventional condition there is large free movement, where balloon reach to large and upper distance in nonconventional (Jan. cases).

Enantioselective Catalytic Aldol Reactions in the Presence of Knoevenagel Nucleophiles: A Chemoselective Switch Optimized in Deep Eutectic Solvents Using Mechanochemistry.

In the presence of different nucleophilic Knoevenagel competitors, cyclic and acyclic ketones have been shown to undergo highly chemoselective aldol reactions with aldehydes. In doing so, the substrate breadth for this emerging methodology has been significantly broadened. The method is also no longer beholden to proline-based catalyst templates, e.g., commercially available O-t-Bu-L-threonine is advantageous for acyclic ketones. The key insight was to exploit water-based mediums under conventional (in-water) and non-conventional (deep eutectic solvents) conditions. With few exceptions, high aldol-to-Knoevenagel chemoselectivity (>10:1) and good product profiles (yield, dr, and ee) were observed, but only in DESs (deep eutectic solvents) in conjunction with ball milling did short reaction times occur.

Enhancing lipases reactivity in benzylic acetates hydrolysis: impact of kosmotropic salts under non-conventional conditions

The effect of four kosmotropic salts additives, namely Na2CO3, Na2SO4, Na2HPO4, and NaCl, on the reactivity and selectivity of immobilized Candida antarctica lipase B (CAL-B) and a free lipase of Pseudomonas cepacia (PCL) during the hydrolysis of rac-4-(1-methoxyphenyl) ethyl and rac − 1-phenyl ethyl acetates (1a-2a) was investigated in this study. The study was carried out in two different mediums: non-aqueous conditions and in low water content media. The impact of the anionic counter-ions was examined in four solvents: nonpolar, semipolar, protic, and aprotic, with and without the aforementioned salts. In non-aqueous media, the addition of Na2CO3 significantly enhanced CAL-B hydrolysis rates, resulting in a conversion of 50% for 1a and 44% for 2a, with high enantioselectivities (E > 200). These effects were independent of the solvent hydrophobicity. In contrast, PCL required the presence of external water for effective hydrolysis of both acetates. The addition of salt additives had an adverse impact on PCL activity during the hydrolysis of 1a in hexane, toluene, and TBME solvents. However, when 2M2B was used, the inclusion of salt additives had a notable positive effect on the conversion rates, except for NaCl, which resulted in a lower conversion rate with a value of 15.5%. The presence of Na2CO3 improved the conversion rate during the hydrolysis of 2a in both hexane and TBME. Na2HPO4 further enhanced the conversion rate, reaching 44% in TBME. However, in 2M2B solvent, the addition of Na2HPO4 significantly reduced the enantioselectivity.

Peroxidative Oxidation of Cyclohexane Using 3d Metal Complexes with Hydrazone-Derived Ligands as Catalysts: Exploring (Un)Conventional Conditions

Two tetranuclear and two mononuclear Cu(II) complexes with arylhydrazones of malononitrile derived ligands (compounds 1–2 and 3–4, respectively), one trinuclear Co(II/III) complex with an arylhydrazone of acetoacetanilide (5) and one tetranuclear Zn(II) complex of 3-(2-carboxyphenyl-hydrazone)pentane-2,4-dione (6) were screened as potential catalysts in the peroxidative oxidation of cyclohexane by aqueous H2O2 in acetonitrile. The best results were attained in the presence of pyrazine-2-carboxylic acid (PCA) with 1 (26% yield, TON = 52.0) and with 2 (24%, TON = 48.0) after 4 h at 40 °C. In the presence of complexes 5 and 6, no oxygenated products were detected in the studied conditions. The employment of non-conventional conditions like supercritical carbon dioxide (scCO2) as reaction medium or microwave (MW) irradiation was assessed for complexes 1 and 2. After 6 h in acetonitrile–scCO2, at 50 °C and with HNO3 as promoter, only 17% yield was achieved using 1 as catalyst, and 21% using 2. Total yields of oxygenates up to 14 (with 1) and 13% (2) and TOFs of 56.0 and 52.0 h−1, respectively, were obtained working under MW irradiation at 70 °C and for the much shorter time of 0.5 h.

О повышении эффективности геологического изучения Каспийского региона на базе уточненной картографической основы

This article aims to improve the methodology and approaches in substantiation of a unified cartographic base for prospective study, planning, and placement of research, forecasting of new oil and gas accumulations. In this case, the basic objectives are the refinement of the regional structure of the Caspian region by taking into account the main geological events during the formation and development, a more precise stratification of the section, specifically, the possible higher detailing of the Devonian and Cenozoic part. To this end, the main “tools” are considered to be the analysis of the paleogeographic environment, and peculiarities of sediment accumulation, which substantiate the formation of centers of maximum filling with fragmentary material, and anomalous objects (large carbon-bearing platforms and atollshaped massifs, mega-elevations, areas with non-conventional conditions for the oil-and-gas-formation processes). According to the preliminary results, their formation was preceded by the development of accumulative sedimentary forms of diverse genesis and paleobathymetric zoning of the sedimentation basin. The structural plan of the region and local anomalies are evaluated with due regard for such non-conventional features for the exploration geology as the structure of the daylight surface terrain, and the pattern of manifestation of anomalies of potential physical fields. Finally, a more detailed cartographic base allows refining some previously substantiated regional regularities in the manifestations of various types of minerals (hydrocarbons, solid commercial minerals, groundwater, ore, and valuable components), unique processes associated with the genesis of anomalous geological features, from the perspective of exploring, forecasting and detection of new oil and gas accumulations. A unified cartographic base constitutes a key factor for the expansion and active integration of geological organizations of all the five Caspian littoral states.

ПРОБЛЕМА ПЕДАГОГИЧЕСКОГО УПРАВЛЕНИЯ ХОДОМ УДАЛЕННОГО ЗАНЯТИЯ ПО ИНОСТРАННОМУ ЯЗЫКУ В ВУЗЕ

The article discusses some features of teaching a foreign lan- guage in the context of an emergency remote shift, that is teaching unplanned and urgently switched from offline to online. It is likely that this format will keep a foothold in future to some extent, so it is worth paying attention to the development of teaching methods for such new specific contexts. The author examines such teaching from the perspectives of the general theory of management and the psychology of learning, incorporating the computer- mediated one. The purpose of the article is to propose an approach to op- timizing “classroom work” in an emergency remote format. The problem of management in a remote foreign language session is considered as a problem of teacher’s understanding of the entire focuses of pedagogical attention and selective intervention on those that need to be adjusted at the moment. Based on the generalization of the author’s own observations, the experience of teaching a foreign language under remote conditions, as well as the analysis of modern scientific research literature and a questionnaire survey of students, a conclusion was made about the productivity of using the basic concepts and provisions of the management theory in relation to the novel nonconventional conditions of language teaching. The role of the educator is similar to that of a manager developing successful pedagogical strategies, some of which are recommended in this paper.

IPEM code of practice for high-energy photon therapy dosimetry based on the NPL absorbed dose calibration service

The 1990 code of practice (COP), produced by the IPSM (now the Institute of Physics and Engineering in Medicine, IPEM) and the UK National Physical Laboratory (NPL), gave instructions for determining absorbed dose to water for megavoltage photon (MV) radiotherapy beams (Lillicrap et al ). The simplicity and clarity of the 1990 COP led to widespread uptake and high levels of consistency in external dosimetry audits. An addendum was published in 2014 to include the non-conventional conditions in Tomotherapy units. However, the 1990 COP lacked detailed recommendations for calibration conditions, and the corresponding nomenclature, to account for modern treatment units with different reference fields, including small fields as described in IAEA TRS483 (International Atomic Energy Agency (IAEA) , Vienna). This updated COP recommends the irradiation geometries, the choice of ionisation chambers, appropriate correction factors and the derivation of absorbed dose to water calibration coefficients, for carrying out reference dosimetry measurements on MV external beam radiotherapy machines. It also includes worked examples of application to different conditions. The strengths of the 1990 COP are retained: recommending the NPL2611 chamber type as secondary standard; the use of tissue phantom ratio (TPR) as the beam quality specifier; and NPL-provided direct calibration coefficients for the user’s chamber in a range of beam qualities similar to those in clinical use. In addition, the formalism is now extended to units that cannot achieve the standard reference field size of 10 cm × 10 cm, and recommendations are given for measuring dose in non-reference conditions. This COP is designed around the service that NPL provides and thus it does not require the range of different options presented in TRS483, such as generic correction factors for beam quality. This approach results in a significantly simpler, more concise and easier to follow protocol.

Thermophysical properties of carbohydrate solutions: Correlation between thermal and transport properties

AbstractSugar solutions such as sucrose, glucose and fructose are often used in osmotic dehydration processes. Thus, the experimental determination of their thermophysical properties is a must for designing purposes. Density, specific heat and thermal conductivity were determined in a wide range of solute concentration (10–60 °Brix) and temperature (273.15–358.15 K). Empirical equations were considered to fit the experimental data and to evaluate the data behavior. An assessment based on the Prandtl number was considered to correlate thermal and rheological data. Higher density and lower specific heat and thermal conductivity values were observed when temperature decreased and solute concentration increased. Prandtl number behaved similarly as density, indicating that momentum transfer is favored in comparison with heat transfer in more concentrated solutions at lower temperatures. A versatile polynomial model concerning the significant variables could predict the experimental values for all solutions with good accuracy (R2 > .9863 and MRE < 1.20%). Reported data and equations showed to be essential for engineering aspects and transport phenomena analysis.Practical ApplicationsSucrose, glucose and fructose solutions are commonly used in osmotic dehydration processes to promote solute incorporation, increasing shelf‐life and quality of food products. The availability of thermophysical properties in a wide range of solute concentration and temperature covers the most of conventional and nonconventional conditions for designing osmotic dehydration and many other food processes. Among the unit operations, it could be found pumping, mixing/stirring, pasteurization, sterilization, evaporation and so on. These data are useful to understand how properties change when the conditions are altered during the processes. They also provide important information about momentum and heat transfer through the fluid. By analyzing dimensionless parameters, as Prandtl number, one phenomenon or other can be favored under specific conditions. The presence of accurate mathematical models results in greater agility and reliability in the execution of processes, especially for those operating in wide ranges of temperature and solute concentration.

Stiffness analysis of leaf spring system under large deformation

The paper proposes a semi-analytical model to analyze large deformation elastic behavior of leaf spring under static load. The model treats leaf spring system as a curved beam with one end directly hinged to a fixed support and the other end being attached to another fixed support through a rigid link (shackle). Constrained motion of the shackle with large deformation of curved beam is modeled using a rotational spring at fixed hinge point of the shackle. Two more physically plausible models for the restraint motion are also proposed, which are derived from the main model through post processing. In the first derived model, the constrained motion is captured by defining a longitudinal spring in a virtual rod connecting the curved beam ends, whereas in the second derived model, the restrained motion is modeled through vertical stiffness of the system. Due to combined complications coming from non-conventional boundary condition, asymmetric geometry, non-uniform curvature, and nonlinear kinematics, the problem is analyzed through successive geometry updation. Governing equation for the curved beam is derived in body fitted curvilinear frame considering combined bending–stretching effects. Global solution for the total system is then obtained by incorporating the elastically restrained shackle motion through satisfaction of kinematic and kinetic constraint relations. As the governing equation and the constraint conditions involve geometric nonlinearity, a numerical iterative scheme is developed and implemented in MATLAB®. For the purpose of validation, the theoretical model is simulated in commercial finite element package ABAQUS®. Comparison of deflection profiles with the finite element model validates the proposed leaf spring model. After the validation study, observations on effects of system parameters and curved leaf profile shape on system stiffnesses are furnished. Effects of the parametric study are presented through true and total system stiffnesses. The parametric study may lead toward optimized design of the system.

Combined effect of pressure and temperature for yogurt production.

Fermentation under non-conventional conditions has gained prominence in the last years, due to the possible process improvements. Fermentation under sub-lethal pressures is one of such cases, and may bring novel characteristics and features to fermentative processes and products. In this work, the effect of both pressure (10-100 MPa) and temperature (25-50 °C) on yogurt production fermentation kinetics was studied, as a case-study. Product formation and substrate consumption were evaluated over fermentation time and the profiles were highly dependent on the fermentation conditions used. For instance, the increase of pressure slowed down yogurt fermentation, but fermentative profiles similar to atmospheric pressure (0.1 MPa) were obtained at 10 MPa at almost all temperatures tested. Regarding temperature, higher fermentative rates were achieved at 43 °C for all pressures tested. Moreover, the inhibitory effect of pressure increased when temperature decreased, with complete inhibition of fermentation occurring at 50 MPa for 25-35 °C, contrasting to 43 °C where inhibition occurred only at 100 MPa. Therefore, an antagonistic effect seems to occur, since yogurt fermentation was slowed down by pressure increasing, on one hand, and by temperature decreasing, on the other hand. Additionally, some kinetic parameters were calculated and fermentation at 43 °C presented the best results for yogurt production, with lower fermentation times and higher lactic acid productivities. Interestingly, fermentation at 10 MPa/43 °C presented the optimal conditions, with improved yield and lactic acid production efficiency, when compared to fermentation at 0.1 MPa (efficiency of 75% at 10 MPa, against 40% at 0.1 MPa). As the authors are aware, this work gives the first insights about the simultaneous effect of pressure and temperature variation on a microbial fermentation process, which can be combined to modulate the metabolic activity of microorganisms during fermentation in order to improve the fermentative yields and productivities of the desired product.

Effect of High Pressure on Paracoccus denitrificans Growth and Polyhydroxyalkanoates Production from Glycerol.

The performance of fermentation under non-conventional conditions, such as high pressure (HP), is a strategy currently tested for different fermentation processes. In the present work, the purpose was to apply HP (10-50MPa) to fermentation by Paracoccus denitrificans, a microorganism able to produce polyhydroxyalkanoates (PHA) from glycerol. In general, cell growth and glycerol consumption were both reduced by HP application, more extensively at higher pressure levels, such as 35 or 50MPa. PHA production and composition was highly dependent on the pressure applied. HP was found to decrease polymer titers, but increase the PHA content in cell dry mass (%), indicating higher ability to accumulate these polymers in the cells. In addition, some levels of HP affected PHA monomeric composition, with the polymer produced at 10 and 35MPa showing considerable differences relative to the ones obtained at atmospheric pressure. Therefore, it is possible to foresee that the changes in polymer composition may also affect its physical and mechanical properties. Overall, the results of this study demonstrated that HP technology (at specific levels) can be applied to P. denitrificans fermentations without compromising the ability to produce PHA, with potentially interesting effects on polymer composition.

Enabling technologies for the preparation of multifunctional “bullets” for nanomedicine

Recent advances in nanotechnology, including modern enabling techniques that can improve synthetic preparation and drug formulations, have opened up new frontiers in nanomedicine with the development of nanoscale carriers and assemblies. The use of delivery platforms has attracted attention over the past decade as researchers shift their focus away from the development of new drug candidates, and toward new means with which to deliver therapeutic and/or diagnostic agents. This work will explore a transdisciplinary approach for the production of a number of nanomaterials, nanocomplexes and nanobubbles and their application in a variety of potential biological and theranostic protocols. Particular attention will be paid to nanobubbles, stimuli responsive nanoparticles and cyclodextrin grafted nanosystems produced under non-conventional conditions, such as microwave and ultrasound irradiation. Besides nanoparticles preparation, ultrasound can also act as an enabling technology when activating sensitive nanobubbles and nanoparticles.

The Hantzsch Pyrrole Synthesis: Non-conventional Variations and Applications of a Neglected Classical Reaction

Pyrrole is one of the most important one-ring heterocycles because of its widespread presence in natural products and unnatural bioactive compounds and drugs in clinical use. The preparation of pyrroles by reaction between primary amines, β-dicarbonyl compounds, and α-halo ketones, known as the Hantzsch pyrrole synthesis, is reviewed here for the first time. In spite of its age and its named reaction status, this method has received little attention in the literature. Recent work involving the use of non-conventional conditions has rejuvenated this classical reaction and this is emphasized in this review. Some applications of the Hantzsch reaction in target-oriented synthesis are also discussed.1 Introduction2 The Conventional Hantzsch Pyrrole Synthesis3 Hantzsch Pyrrole Synthesis under Non-conventional Conditions4 Applications of the Hantzsch Pyrrole Synthesis5 Conclusions

Finite elements with node dependent kinematics and scalable accuracy for the analysis of Stokes flows

This paper extends the use of one-dimensional elements with node-dependent kinematics to the analysis of Stokes flows. According to the Carrera Unified Formulation, the primary variables of the flow, velocity and pressure, are expressed as arbitrary expansions of the generalized unknowns. The novel implementation proposed in this work allows to increase the accuracy of the model only in the areas of the domain where it is required; i.e. close to boundaries, barriers or sudden expansion. Refined one-dimensional models based on Taylor and Lagrange expansions are used in this work and some typical applications are proposed to assess this novel technique, including Stokes flows in cylindrical and non-conventional domains. For each numerical example, different combinations of one-dimensional models have been considered to account for different kinematic approximations of flows, and the results, compared with analytical or finite volume solutions, highlight the capabilities of the proposed approach to handle non-conventional boundary conditions with ease and in preserving the computational cost without any accuracy loss.

Catalyzed synthesis of functionalized pyrrolo[3,4-b]quinolines via one-pot three-component reactions under conventional and nonconventional conditions

A general, facile, and efficient method for the synthesis of pyrrolo[3,4-b]quinolines is presented. The reactions pathway involve one-pot three-component reactions of β-enamino imides, aromatic aldehydes, and dimedone catalyzed by trifluoroacetic acid, under conventional thermal heating or ultrasounds irradiation, as nonconventional method of synthesis. It is shown that under ultrasounds irradiation, the reaction time decreases significantly (from hours to minutes) and, in some cases, the yields are much better.

ChemInform Abstract: An Efficient Method for Thiocyanation of Aromatic and Heteroaromatic Compounds Using Cyanuric Chloride and Ammonium Thiocyanate under Conventional and Nonconventional Conditions.

Highly efficient thiocyanation of aromatic and heteroaromatic compounds has been accomplished by using cyanuric chloride (NCCl)3/NH4SCN in dichloromethane under conventional and ultrasonic-assisted conditions. Sonicated reactions reached completion with reduced reaction times. The protocol involves a simple workup.

PEG Assisted Manganese (II) Carbonate as an Efficient Catalyst for Regioselective Nitration of Aromatic Compounds Under Acid Free Conventional and Non-Conventional Conditions Using NaNO2

PEG Assisted Manganese (II) Carbonate as an Efficient Catalyst for Regioselective Nitration of Aromatic Compounds Under Acid Free Conventional and Non-Conventional Conditions Using NaNO2

Zeolite Y-assisted nitration of aromatic and heterocyclic compounds and decarboxylative nitration of α,β-unsaturated acids under non-conventional conditions

The approach outlined in this paper is particularly appropriate for the conversion of unsaturated cinnamic acids into nitrostyrenes.

An Efficient Method for Thiocyanation of Aromatic and Heteroaromatic Compounds using Cyanuric Chloride and Ammonium Thiocyanate under Conventional and Nonconventional Conditions

Highly efficient thiocyanation of aromatic and heteroaromatic compounds has been accomplished by using cyanuric chloride (NCCl)₃/NH₄SCN in dichloromethane under conventional and ultrasonic-assisted conditions. Sonicated reactions reached completion with reduced reaction times. The protocol involves a simple workup.