A new hybrid iron fluoride bipyridine with mixed valence: Fe2F5(2,2'-bipyridine)2H2O

Hydrothermal synthesis of iron fluoride compound, Fe2F5(2,2'-bipyridine)2H2O, and its characterization by single crystal X-ray diffraction is reported. The compound is found to crystallize in the triclinic space group . The monohydrate fluoroferrate of bipyridine is built up from Fe4F10N8 tetrahedron connected by eight nitrogen atoms of four 2,2'-bipyridine molecules and separated by H2O molecules. The main feature of this atomic arrangement is the coexistence of two oxidation states of iron cations and hybrid class II with 0-D dimensionality. Thermal and IR spectral analysis have been carried out for the title compound to confirm the hematite compound as residual and the presence of organic molecule , respectively. Magnetic characterization does not reveal any ferromagnetic component in the range of magnetic field from -20 kOe to 20 kOe at room temperature

A new hybrid iron fluoride bipyridine with mixed valence: Fe2F5(2,2'-bipyridine)2H2O

810-815Hydrothermal synthesis of iron fluoride compound, Fe2F5(2,2'-bipyridine)2H2O, and its characterization by single crystal X-ray diffraction is reported. The compound is found to crystallize in the triclinic space group . The monohydrate fluoroferrate of bipyridine is built up from Fe4F10N8 tetrahedron connected by eight nitrogen atoms of four 2,2'-bipyridine molecules and separated by H2O molecules. The main feature of this atomic arrangement is the coexistence of two oxidation states of iron cations and hybrid class II with 0-D dimensionality. Thermal and IR spectral analysis have been carried out for the title compound to confirm the hematite compound as residual and the presence of organic molecule , respectively. Magnetic characterization does not reveal any ferromagnetic component in the range of magnetic field from -20 kOe to 20 kOe at room temperature

Electronic Supplementary Data A new hybrid iron fluoride bipyridine with mixed valence: Fe2F5(2,2′-bipyridine)2H2O

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Fluoroferrate templated with HAmTAZ: X-ray single crystal, thermal behaviour, vibrational study and magnetic characterization

A new metal–organic compound FeF6(HAmTAZ)3 which (HAmTAZ = 3-amino-1,2,4-triazole) was hydrothermally synthesized from an equimolar mixture of FeF2 and FeF3 with HAmTAZ, aqueous HF and ethanol solvent at 410 K yielded a new hybrid class I fluoroferrate. The structure was characterized by single-crystal X-ray diffraction data. The crystal structure of FeF6(HAmTAZ)3 crystallizes in the trigonal system space group R3c with a = b = 12.5230 (6) Å, c = 18.5950 (16) Å, γ = 120° and Z = 6. The structure was built up from isolated octahedral FeF6 separated by [HAmTAZ]+ cations. The thermal analysis has shown that the decomposition undergoes two steps between 475 and 775 K. IR and mass spectrometry have been used to confirm the presence of the organic molecule in the crystal lattice and determine the evacuated vapours during the decomposition, respectively. The magnetization of the title compound has no revealed any ferromagnetic component in the range of magnetic field from −20 to 20 KOe at room temperature.This research work is supported by the Tunisian Ministry of Higher Education and Research and the Spanish MINECO (MAT2006-150AM).Peer Reviewe

Hydrothermal synthesis, thermal decomposition and optical properties of Fe2F5(H2O)(Htaz)(taz)(Hdma)

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Structure, Thermal Behavior and Characterization of a New Hybrid Iron Fluoride FeF4(2,2 '-bipyridine)(H2O)(2)

New crystal of FeF4(2,2′-bipyridine)(H2O)2 was prepared by hydrothermal synthesis. Crystalline structure determination is performed from single crystal X-ray diffraction data. The unit cell is monoclinic space group P21/n, with cell parameters a=0.9046(5) nm, b=0.7502(5) nm, c=1.9539(5) nm, β=93.307(5)°, V=1.3238(12) nm3 and Z=4. The structure of FeF4(2,2′-bipyridine)(H2O)2 is built up from FeF4N2 octahedra coordinated by two nitrogen atoms of the 2,2′-bipyridine molecules, and four fluorine atoms as well as uncoordinated H2O molecules. Thermal analysis of the title compound showed that the decomposition introduced four steps. IR spectra confirmed the presence of 2,2′-bipyridine molecules. The optical absorption was measured at the corresponding λmax using UV-Vis diffuse reflectance spectrum.Supported by the Project from the Ministry of Superior Education and the Research of Tunisia and Spanish MINECO (No. MAT2006-150AM).Peer Reviewe

Hydrothermal synthesis, thermal decomposition and optical properties of Fe2F5(H2O)(Htaz)(taz)(Hdma)

Crystal structure of Fe2F5(H2O)(Htaz)(taz)(Hdma) which crystallizes in the triclinic sys-tem space group P1 with unit cell parametersa= 8.8392(5) A ̊,b= 9.1948(5) A ̊,c= 9.5877(5) A ̊,a= 82.070(3)°,b= 63.699(3)°,c= 89.202(3)°,Z= 2, andV= 690.91(7) A ̊3, was synthesizedunder hydrothermal conditions at 393 K for 72 h, by a mixture of FeF2/FeF3, 1,2,4-triazole mole-cule (Htaz), and hydrofluoric acid solution (HF 4%) in dimethylformamide solvent (DMF). Themain feature of this material is the coexistence of two oxidation states for iron atoms (Fe2+,Fe3+) in the unit cell, which associate by opposite fluorine corners of FeF5N and FeF2N4octahe-dra, and/or triazole molecule which originates the 2D produces material. The structure determina-tion, performed from single crystal X-ray diffraction data, lead to theR1/WR2reliability factors0.031/0.087. Thermal stability studies (TG/DTG/DTA) show that the decomposition provides inthe temperature range 473–773 K and no mass loss was detected before 473 K. Mass spectrometry(MS) has been used. The optical absorption of the solid was measured at the correspondingkmaxusing UV–vis diffuse-reflectance spectrum.This work was supported by the minister of superior educationand research of Tunisia and Spanish MINECO (MAT2013-40950R

Towards an Optimized Blockchain-Based Secure Medical Prescription-Management System

This work introduces a blockchain-based secure medical prescription-management system seamlessly integrated with a dynamic Internet of Things (IoT) framework. Notably, this integration constitutes a pivotal challenge in the arena of resource-constrained IoT devices: energy consumption. The choice of a suitable blockchain consensus mechanism emerges as the linchpin in surmounting this hurdle. Thus, this paper conducts a comprehensive comparison of energy consumption between two distinct consensus mechanisms: Proof of Work (PoW) and Quorum-based Byzantine fault tolerance (QBFT). Furthermore, an assessment of the most energy-efficient algorithm is performed across multiple networks and various parameters. This approach ensures the acquisition of reliable and statistically significant data, enabling meaningful conclusions to be drawn about the system’s performance in real-world scenarios. The experimental results show that, compared to the PoW, the QBFT consensus mechanism reduced the energy consumption by an average of 5%. This finding underscores the significant advantage of QBFT in addressing the energy consumption challenges posed by resource-constrained IoT devices. In addition to its inherent benefits of privacy and block time efficiency, the Quorum blockchain emerges as a more sustainable choice for IoT applications due to its lower power consumption

Optimization of lipids’ ultrasonic extraction and production from Chlorella sp. using response-surface methodology

Abstract Background Three steps are very important in order to produce microalgal lipids: (1) controlling microalgae cultivation via experimental and modeling investigations, (2) optimizing culture conditions to maximize lipids production and to determine the fatty acid profile the most appropriate for biodiesel synthesis, and (3) optimizing the extraction of the lipids accumulated in the microalgal cells. Methods Firstly, three kinetics models, namely logistic, logistic-with-lag and modified Gompertz, were tested to fit the experimental kinetics of the Chlorella sp. microalga culture established on standard conditions. Secondly, the response-surface methodology was used for two optimizations in this study. The first optimization was established for lipids production from Chlorella sp. culture under different culture conditions. In fact, different levels of nitrate concentrations, salinities and light intensities were applied to the culture medium in order to study their influences on lipids production and determine their fatty acid profile. The second optimization was concerned with the lipids extraction factors: ultrasonic’s time and temperature, and chloroform-methanol solvent ratio. Results All models (logistic, logistic-with-lag and modified Gompertz) applied for the experimental kinetics of Chlorella sp. show a very interesting fitting quality. The logistic model was chosen to describe the Chlorella sp. kinetics, since it yielded the most important statistical criteria: coefficient of determination of the order of 94.36%; adjusted coefficient of determination equal to 93.79% and root mean square error reaching 3.685 cells · ml− 1. Nitrate concentration and the two interactions involving the light intensity (Nitrate concentration × light intensity, and salinities × light intensity) showed a very significant influence on lipids production in the first optimization (p < 0.05). Yet, only the quadratic term of chloroform-methanol solvent ratio showed a significant influence on lipids extraction relative to the second step of optimization (p < 0.05). The two most abundant fatty acid methyl esters (≈72%) derived from the Chlorella sp. microalga cultured in the determined optimal conditions are: palmitic acid (C16:0) and oleic acid (C18:1) with the corresponding yields of 51.69% and 20.55% of total fatty acids, respectively. Conclusions Only the nitrate deficiency and the high intensity of light can influence the microalgal lipids production. The corresponding fatty acid methyl esters composition is very suitable for biodiesel production. Lipids extraction is efficient only over long periods of time when using a solvent with a 2/1 chloroform/methanol ratio