Hydrodesulfurization unit for natural gas condensate

Journal of Thermal Analysis and Calorimetry - Nowadays, most of the world’s energy consumption is from fossil fuels. One of these fossil fuels is natural gas condensate which consists of...     

Concurrence and Quantum Discord in the Eigenstates of Chaotic and Integrable Spin Chains

There has been some substantial research about the connections between quantum chaos and quantum correlations in many-body systems. This paper discusses a specific aspect of correlations in chaotic spin models, through concurrence (CC) and quantum discord (QD). Numerical results obtained in the quantum chaos regime and in the integrable regime of spin-1/2 chains are compared. The CC and QD between nearest-neighbor pairs of spins are calculated for all energy eigenstates. The results show that, depending on whether the system is in a chaotic or integrable regime, the distribution of CC and QD are markedly different. On the other hand, in the integrable regime, states with the largest CC and QD are found in the middle of the spectrum, in the chaotic regime, the states with the strongest correlations are found at low and high energies at the edges of spectrum. Finite-size effects are analyzed, and some of the results are discussed in the light of the eigenstate thermalization hypothesis.     

Bilayer Cylindrical Conduit Consisting of Electrospun Polycaprolactone Nanofibers and DSC Cross‐Linked Sodium Alginate Hydrogel to Bridge Peripheral Nerve Gaps

Herein, a bilayer cylindrical conduit (P‐CA) is presented consisting of electrospun polycaprolactone (PCL) nanofibers and sodium alginate hydrogel covalently cross‐linked with N,N′‐disuccinimidyl carbonate (DSC). The bilayer P‐CA conduit is developed by combining the electrospinning and outer–inner layer methods. Using DSC, as a covalent crosslinker, increases the degradation time of the sodium alginate hydrogel up to 2 months. The swelling ratio of the hydrogel is also 503% during the first 8 h. The DSC cross‐linked sodium alginate in the inner layer of the conduit promotes the adhesion and proliferation of nerve cells, while the electrospun PCL nanofibers in the outer layer provide maximum tensile strength of the conduit during surgery. P‐CA conduit promotes the migration of Schwann cells along the axon in a rat model based on functional and histological evidences. In conclusion, P‐CA conduit will be a promising construct for repairing sciatic nerves in a rat model.     

Preparation and characterization of a novel DABCO-based ionic liquid supported on Fe3O4@TiO2 nanoparticles and investigation of its catalytic activity in the synthesis of quinazolinones

In this study, quinazolinone derivatives have been synthesized via a suitable and efficient procedure by one-potmulti-component reactions of 3-amino-1,2,4-triazole or 2-aminobenzimidazole, dimedone and aromatic aldehydes in the presence of Fe₃O₄@TiO₂-IL as nanocatalyst under solvent-free condition. The products were prepared in good to excellent yields using Fe₃O₄@TiO₂-IL magnetic nanocatalyst. The Fe₃O₄@TiO₂ magnetic nanoparticles (MNPs) were prepared using beet juice extract and functionalized with IL based on DABCO. Moreover, the core-shell structured magnetic Fe₃O₄@TiO₂-IL has been characterized by different techniques such as ¹H-NMR, FT-IR, VSM, XRD, SEM, TGA, TEM and EDX. To the best of our knowledge, the prepared ionic liquid displayed a good protective and activator agent for magnetic nanocatalyst.     

Palladium nanoparticles immobilized over Strawberry fruit extract coated Fe3O4 NPs: A magnetic reusable nanocatalyst for Suzuki-Miyaura coupling reactions

This paper develops a green method for in situ decorated of palladium nanoparticles over Fe₃O₄ nanoparticles, by utilizing Strawberry fruit extract and ultrasound irradiations, with no use of any toxic reducing agent. The structure's characterization is represented via diverse analytical methods such as FT-IR, FE-SEM, TEM, WDX, ICP, EDS and XXPS. Catalytic efficiency of magnetic Fe₃O₄@Strawberry/Pd nanocatalyst is investigated in production of different biphenyls with good turnover frequencies (TOF) and turnover numbers (TON) through Suzuki coupling reactions. Furthermore, the catalyst could be recovered and reused 7 runs without considerable palladium leaching or alteration in its performance.     

Spectral,crystallographic, theoretical and antibacterial studies of palladium(II)/platinum(II) complexes with unsymmetric diphosphine ylides

The reaction of α‐keto‐stabilized diphosphine ylides [Ph₂P(CH₂)_nPPh₂═C(H)C(O)C₆H₄‐p‐CN] (n = 1 (Y¹); n = 2 (Y²)) with dibromo(1,5‐cyclooctadiene) palladium(II)/platinum(II) complexes, [Pd/PtBr₂(cod)], in equimolar ratio gave the new cyclometalated Pd(II) and Pt(II) complexes [Br₂Pd(κ²‐Y¹)] ( 1 ), [Br₂Pt(κ²‐Y¹)] ( 2 ), [Br₂Pd(κ²‐Y²)] ( 3 ) and [Br₂Pt(κ²‐Y²)] ( 4 ). These compounds were screened in a search for novel antibacterial agents and characterized successfully using Fourier transfer infrared and NMR (¹H, ¹³C and ³¹P) spectroscopic methods. Also, the structures of complexes 1 and 2 were characterized using X‐ray crystallography. The results showed that the P,C‐chelated complexes 1 and 2 have structures consisting of five‐membered rings, while 3 and 4 have six‐membered rings, formed by coordination of the ligand through the phosphine group and the ylidic carbon atom to the metal centre. Also, a theoretical study of the structures of complexes 1 – 4 was conducted at the BP86/def2‐SVP level of theory. The nature of metal–ligand bonds in the complexes was investigated using energy decomposition analyses (EDA) and extended transition state combined with natural orbitals for chemical valence analyses. The results of EDA confirmed that the main portions of ΔE_int, about 57–58%, in the complexes are allocated to ΔE_elstat.     

Investigation the effects of shear rate on stationary droplets coalescence by lattice Boltzmann

Coalescence is the process by which two or more droplets merge to form a single droplet. It can take place in many processes, ranging from meteorology to astrophysics. When two stationary droplets are suspended in a bulk vapor, if the gap between the droplets has been smaller than a critical value, the two droplets will coalesce. In this paper, single component, two phase flow is modeled under shear flow using a free energy lattice Boltzmann approach and the coalescence of stationary droplets are investigated for different cases of radius and shear rate. The results show that there is a critical gap between droplets and for the values larger than that they will not coalesce. Also in the case of constant thermophysical properties, this critical gap is a function of droplet radius and shear rate.