Physical Parameters of the Synthesized Complex Compound of Cobalt (II) with N, N'-Bis(salicylidene)semicarbazide

A new material of strontium tetraaquad[N, N'-bis(salicylidene)semicarbazidatocobalt(II)] dihydrate (I) with the following composition: Sr[CoL'(Н2О)2]22Н2О, where H3L = N,N'-bis(salicylidene)semicarbazide was synthesized. The molar mass of the extracted and dehydrated complex compound Sr[Co (C15H14N3O5)]2 is 838.07 g/mol, and the number of valence electrons in one molecule is 256. A cylindrical sample with a mass of 0.09 g and a volume of 17.67∙10-9 m3 was utilized for experimental studies. Experimental measurements and theoretical calculations for the main physical parameters of the synthesized material were performed. Such quantities were calculated: the substance density, the molecule mass, the number of molecules in the test cylindrical sample, the number of valence electrons, the bandgap. Dependences of specific conductivity, current density, resistance, the Hall coefficient, and charge carrier concentration on temperature were obtained.

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Theoretical and experimental studies of palladium-catalyzed site-selective C(sp3)−H bond functionalization enabled by transient ligands

10.26434/chemrxiv.5717950 ◽

2017 ◽

Author(s):

Haibo Ge ◽

Lei Pan ◽

Piaoping Tang ◽

Ke Yang ◽

Mian Wang ◽

...

Keyword(s):

Bond Activation ◽

Theoretical Calculations ◽

Experimental Studies ◽

Bond Functionalization ◽

Aliphatic Ketones ◽

Site Selectivity ◽

Mechanistic Investigation ◽

Palladium Catalyzed ◽

Metal Catalyzed ◽

Site Selective

Transition metal-catalyzed selective C–H bond functionalization enabled by transient ligands has become an extremely attractive topic due to its economical and greener characteristics. However, catalytic pathways of this reaction process on unactivated sp3 carbons of reactants have not been well studied yet. Herein, detailed mechanistic investigation on Pd-catalyzed C(sp3)–H bond activation with amino acids as transient ligands has been systematically conducted. The theoretical calculations showed that higher angle distortion of C(sp2)-H bond over C(sp3)-H bond and stronger nucleophilicity of benzylic anion over its aromatic counterpart, leading to higher reactivity of corresponding C(sp3)–H bonds; the angle strain of the directing rings of key intermediates determines the site-selectivity of aliphatic ketone substrates; replacement of glycine with β-alanine as the transient ligand can decrease the angle tension of the directing rings. Synthetic experiments have confirmed that β-alanine is indeed a more efficient transient ligand for arylation of β-secondary carbons of linear aliphatic ketones than its glycine counterpart.

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Cat-CrNP as new material with catalytic properties for 2-chloro-2-propen-1-ol and ethylene oligomerizations

Scientific Reports ◽

10.1038/s41598-021-94056-0 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Jacek Malinowski ◽

Dagmara Jacewicz ◽

Artur Sikorski ◽

Mariusz Urbaniak ◽

Przemysław Rybiński ◽

...

Keyword(s):

Complex Compound ◽

Atmospheric Pressure ◽

Room Temperature ◽

Organometallic Compounds ◽

Ethylene Oligomerization ◽

High Catalytic Activity ◽

New Material ◽

Activity Requirement ◽

Olefin Oligomerization ◽

Xrd Method

AbstractThe contemporary search for new catalysts for olefin oligomerization and polymerization is based on the study of coordinating compounds and/or organometallic compounds as post-metallocene catalysts. However known catalysts are suffered by many flaws, among others unsatisfactory activity, requirement of high pressure or instability at high temperatures. In this paper, we present a new catalyst i.e. the crystalline complex compound possesing high catalytic activity in the oligomerization of olefins, such as 2-chloro-2-propen-1-ol and ethylene under very mild conditions (room temperature, 0.12 bar for ethylene oligomerization, atmospheric pressure for 2-chloro-2-propen-1-ol oligomerization). New material—Cat-CrNP ([nitrilotriacetato-1,10-phenanthroline]chromium(III) tetrahydrate) has been obtained as crystalline form of the nitrilotriacetate complex compound of chromium(III) with 1,10-phenanthroline and characterized in terms of its crystal structure by the XRD method and by multi-analytical investigations towards its physicochemical propeties The yield of catalytic oligomerization over Cat-CrNP reached to 213.92 g · mmol−1 · h−1· bar−1 and 3232 g · mmol−1 · h−1 · bar−1 for the 2-chloro-2-propen-1-ol and ethylene, respectively. Furthemore, the synthesis of Cat-CrNP is cheap, easy to perform and solvents used during preparation are environmentally friendly.

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Analytical and Experimental Simulation of Loose Pedestal Dynamic Effects on a Rotating Machine Vibrational Response

13th Biennial Conference on Mechanical Vibration and Noise: Rotating Machinery and Vehicle Dynamics ◽

10.1115/detc1991-0223 ◽

1991 ◽

Author(s):

Pavel Goldman ◽

Agnes Muszynska

Keyword(s):

Excitation Frequency ◽

Experimental Studies ◽

Experimental Simulation ◽

Physical Parameters ◽

Vibrational Response ◽

Rotating Machine ◽

Qualitative Pattern ◽

The Impact ◽

Good Agreement ◽

Periodic Changes

Abstract This report presents experimental, analytical, and numerical results describing vibrational phenomena in a rotating machine with one loose pedestal. The loose-pedestal machine rotor vibrations represent unbalance-related excited vibrations of synchronous and fractional subsynchronous regimes. In this study the loose-pedestal machine is first simulated by a simple vibrating beam excited by a shaker mounted on it. The shaker simulates an unbalanced machine rotor. The beam occasionally enters in contact with the foundation. The excited vibrations are modified by impacting occurrences, and by periodic changes in system stiffness. A new model of the impact has been developed. The results of analytical and experimental studies stand in a good agreement. They illustrate the existence of the synchronous regime and several subsynchronous fractional regimes in various excitation frequency ranges. The analysis adequately predicts the occurrence of these regimes and determines the physical parameters affecting them. The analytical and experimental results are then compared with the responses of experimental rotor rig with one bearing pedestal looseness. They show the same qualitative pattern.

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Fractal and Non-Fractal Surfaces in Ion Sputtering

MRS Proceedings ◽

10.1557/proc-407-259 ◽

1995 ◽

Vol 407 ◽

Author(s):

A.-L. Barabási ◽

R. Cuerno

Keyword(s):

Nonlinear Equation ◽

Penetration Depth ◽

Experimental Studies ◽

Ion Bombardment ◽

Physical Parameters ◽

Angle Of Incidence ◽

Ion Sputtering ◽

Scaling Properties ◽

Fractal Surfaces ◽

Experimental Parameters

ABSTRACTRecently a number of experimental studies focusing on the scaling properties of surfaces eroded by ion bombardment provided apparently contradictory results. A number of experiments report the observation of self-affine fractal surfaces, while others provide evidence about the development of a non-fractal periodic ripple structure. To explain these discrepancies, here we derive a stochastic nonlinear equation that describes the evolution and scaling properties of surfaces eroded by ion bombardment. The coefficients appearing in the equation can be calculated explicitly in terms of the physical parameters characterizing the sputtering process. We find that transitions may take place between various scaling behaviors when experimental parameters, such as the angle of incidence of the incoming ions or their average penetration depth, are varied.

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Inelastic seismic shear amplification due to higher mode effects in reinforced concrete coupled walls

Earthquake Spectra ◽

10.1177/87552930211053347 ◽

2021 ◽

pp. 875529302110533

Author(s):

Gabriel Rivard ◽

Steeve Ambroise ◽

Patrick Paultre

Keyword(s):

Reinforced Concrete ◽

Parametric Study ◽

Numerical Study ◽

Plastic Hinge ◽

Experimental Studies ◽

Physical Parameters ◽

Intensity Level ◽

Shear Forces ◽

Coupled Walls ◽

Seismic Shear

Recent numerical and experimental studies on reinforced concrete shear walls and coupled walls have shown shear forces greater than expected when the walls are subjected to earthquakes at an intensity level that does not exceed the design values. This amplification of shear forces is attributable to the effects of higher modes after the walls develop a plastic hinge at the base. These effects have been recently recognized in North American design codes for cantilever walls and is currently neglected in the design of ductile coupled walls. As part of the research program described in this article, a parametric study was carried out on coupled wall systems to identify the geometric and physical parameters having the greatest influence on the seismic shear amplification. Using the results of this parametric study, an extensive numerical study was conducted on classes of ductile coupled walls subjected to seismic excitation representative of Western and Eastern Canada. This extensive study led to the establishment of shear amplification prediction equations for use in building codes.

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Research of stamping of unequal channel bars. Part 5. Methods for calculating the extrusion of channels. 2. Extrusion of non-strengthening material

10.36652/0042-4633-2021-10-46-52 ◽

2021 ◽

pp. 46-52

Author(s):

A.L. Vorontsov

Keyword(s):

Plane Strain ◽

Theoretical Calculations ◽

Experimental Studies ◽

High Accuracy ◽

Experimental Results ◽

Die Forging

The results of experimental studies on the extrusion of channels from non-strengthening material are presented. Comparison of theoretical calculations with experimental results showed the high accuracy of the derived formulas. Keywords: die forging, extrusion, punch, matrix, misalignment, plane strain. [email protected]

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Platinum–copper single atom alloy catalysts with high performance towards glycerol hydrogenolysis

Nature Communications ◽

10.1038/s41467-019-13685-2 ◽

2019 ◽

Vol 10 (1) ◽

Cited By ~ 33

Author(s):

Xi Zhang ◽

Guoqing Cui ◽

Haisong Feng ◽

Lifang Chen ◽

Hui Wang ◽

...

Keyword(s):

Active Sites ◽

High Performance ◽

Reaction Pathway ◽

Theoretical Calculations ◽

Experimental Studies ◽

Value Added ◽

Catalytic Performance ◽

Single Atom ◽

Glycerol Hydrogenolysis ◽

Single Atom Alloy

AbstractSelective hydrogenolysis of biomass-derived glycerol to propanediol is an important reaction to produce high value-added chemicals but remains a big challenge. Herein we report a PtCu single atom alloy (SAA) catalyst with single Pt atom dispersed on Cu nanoclusters, which exhibits dramatically boosted catalytic performance (yield: 98.8%) towards glycerol hydrogenolysis to 1,2-propanediol. Remarkably, the turnover frequency reaches up to 2.6 × 103 molglycerol·molPtCu–SAA−1·h−1, which is to our knowledge the largest value among reported heterogeneous metal catalysts. Both in situ experimental studies and theoretical calculations verify interface sites of PtCu–SAA serve as intrinsic active sites, in which the single Pt atom facilitates the breakage of central C–H bond whilst the terminal C–O bond undergoes dissociation adsorption on adjacent Cu atom. This interfacial synergistic catalysis based on PtCu–SAA changes the reaction pathway with a decreased activation energy, which can be extended to other noble metal alloy systems.

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Numerical simulation of the stress-strain state of complex-reinforced elements

Tehnički glasnik ◽

10.31803/tg-20190417112619 ◽

2019 ◽

Vol 13 (2) ◽

pp. 110-115

Author(s):

Olena Krantovska ◽

Mykola Petrov ◽

Liubov Ksonshkevych ◽

Matija Orešković ◽

Sergii Synii ◽

...

Keyword(s):

Numerical Simulation ◽

Strain State ◽

Theoretical Calculations ◽

Experimental Studies ◽

Theoretical Studies ◽

Stress Strain ◽

Narrow Strip ◽

Stress Strain State ◽

Graphical Environment ◽

Experimental And Theoretical Studies

The article describes a developed technique of a numerical simulation of the stress-strain state of complex-reinforced elements, which allows you to create models of double-span continuous. The performed experimental and theoretical studies allowed us to carry out the testing of the developed design model and to justify the reliability of the proposed numerical simulation methodology. The results of the experimental studies were compared with those of the theoretical studies. The theoretical calculus algorithm was developed by using the finite element method. Theoretical calculations were performed by using the mathematical-graphical environment software system LIRA-SOFT and the mathematical and computer program MATLAB. On the basis of the experimental research, the iso-fields of displacements and stresses in the materials of an eccentrically compressed beam with a small bend of the slab were constructed, which collapse behind the inclined narrow strip of concrete and displacements and stresses in the materials of the eccentrically stretched beam, which is destroyed due to the yield of the upper mounting armature.

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Graph-Analytical Estimation Method of Natural Ventilation Efficiency during Natural Gas Combustion

Materials Science Forum ◽

10.4028/www.scientific.net/msf.931.901 ◽

2018 ◽

Vol 931 ◽

pp. 901-904 ◽

Cited By ~ 1

Author(s):

Victor I. Chebotarev ◽

Anastasia P. Pirozhnikova ◽

Alla V. Koroleva

Keyword(s):

Natural Gas ◽

Natural Ventilation ◽

Theoretical Calculations ◽

Residential Buildings ◽

Experimental Studies ◽

Estimation Method ◽

Combustion Products ◽

Gas Combustion ◽

Analytical Estimation ◽

Ventilation Duct

Open burning of natural gas when using gas equipment in the premises of residential buildings is considered, taking into account the formation of combustion products, depending on the coefficients of excess air. Theoretical and experimental studies of combustion processes are presented. To determine the aerodynamic process in the ventilation duct, theoretical calculations of the dependence of the discharge at the entrance to the ventilation duct from the outside temperature of the atmospheric air were made. Graph-analytic method of evaluating the effectiveness of natural ventilation is carried out.

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Multilayered stable 2D nano-sheets of Ti2NTx MXene: synthesis, characterization, and anticancer activity

Journal of Nanobiotechnology ◽

10.1186/s12951-019-0545-4 ◽

2019 ◽

Vol 17 (1) ◽

Cited By ~ 10

Author(s):

A. Szuplewska ◽

A. Rozmysłowska-Wojciechowska ◽

S. Poźniak ◽

T. Wojciechowski ◽

M. Birowska ◽

...

Keyword(s):

Biological Activity ◽

Mammary Epithelial Cells ◽

Theoretical Calculations ◽

Experimental Studies ◽

Reactive Oxygen ◽

Decisive Role ◽

Max Phase ◽

Mechanisms Of Toxicity ◽

Biological Studies

Abstract Background The biological activity of MXenes has been studied for several years because of their potential biomedical applications; however, investigations have so far been limited to 2D titanium carbides. Although monolayered Ti2NTx MXene has been expected to have biological activity, experimental studies revealed significant difficulties due to obstacles to its synthesis, its low stability and its susceptibility to oxidation and decomposition. Results In this paper, we report our theoretical calculations showing the higher likelihood of forming multilayered Ti2NTx structures during the preparation process in comparison to single-layered structures. As a result of our experimental work, we successfully synthesized multilayered Ti2NTx MXene that was suitable for biological studies by the etching of the Ti2AlN MAX phase and further delamination. The biocompatibility of Ti2NTx MXene was evaluated in vitro towards human skin malignant melanoma cells, human immortalized keratinocytes, human breast cancer cells, and normal human mammary epithelial cells. Additionally, the potential mode of action of 2D Ti2NTx was investigated using reactive oxygen tests as well as SEM observations. Our results indicated that multilayered 2D sheets of Ti2NTx showed higher toxicity towards cancerous cell lines in comparison to normal ones. The decrease in cell viabilities was dose-dependent. The generation of reactive oxygen species as well as the internalization of the 2D sheets play a decisive role in the mechanisms of toxicity. Conclusions We have shown that 2D Ti2NTx in the form of multilayered nanoflakes exhibits fair stability and can be used for in vitro studies. These results show promise for its future applications in biotechnology and nanomedicine.

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