displaying 1000 best results Help
Search results for: METAL-SALEN COMPLEXES
-
Biochemistry - Laboratory exercises
e-Learning CoursesExerise 1. The ability to accumulate metal cations by edible mushrooms, comparison with edible plants Exercise 2. Measurement of activity of glutathione S-transferases - the detoxifying enzymes present in the cytosol of eukaryotic cells Exercise 3. Cell membranes permeability Exercise 4. Detection of mutagenic substances using Ames test Exercise 5. Gluten content in food products part 1. Exercise 6. Gluten content in food...
-
Ongoing progress on novel nanocomposite membranes for the separation of heavy metals from contaminated water
PublicationMembranes, as the primary separation element of membrane-based processes, have greatly attracted the attention of researchers in several water treatment applications, including wastewater treatment, water purification, water disinfection, toxic and non-toxic chemical molecules, heavy metals, among others. Today, the removal of heavy metals from water has become challenging, in which chemical engineers are approaching new materials...
-
Ball milling treatment of Mn3O4 regulates electron transfer pathway for peroxymonosulfate activation
PublicationHeterogeneous metal catalysts have attracted considerable interest in advanced oxidation processes (AOPs) for wastewater treatment by activating peroxymonosulfate (PMS). However, it remains challenging to the rational design of efficient reaction pathway for high-performance contaminants removal by regulating the inherent structure of metal oxides. Herein, a high-energy ball milling method was employed to modulate the electronic...
-
MOF/TiO2 erythrocyte-like heterostructures decorated by noble metals for use in hydrogen photogeneration and pollutant photodegradation
PublicationVarious metal–organic framework (MOF)/TiO2 heterostructures can be obtained by the partial hydrolysis or calcination of Ti-based MOFs. By adjusting the hydrolysis and calcination steps of NH2-MIL-125 (Ti), a novel photoactive material composed of a MOF (NH2-MIL-125 (Ti)) and TiO2, with a unique “erythrocyte” shape, was developed. Furthermore, modification of the composition prepared by the partial hydrolysis of NH2- MIL-125 (Ti)...
-
A new strategy for PET depolymerization: Application of bimetallic MOF-74 as a selective catalyst
PublicationLarge-volume production of poly(ethylene terephthalate) (PET), especially in the form of bottles and food packaging containers, causes problems with polymer waste management. Waste PET could be recycled thermally, mechanically or chemically and the last method allows to obtain individual monomers, but most often it is carried out in the presence of homogeneous catalysts, that are difficult to separate and reuse. In view of this,...
-
Ionic liquids for nano- and microstructures preparation. Part 1: Properties and multifunctional role
PublicationIonic liquids (ILs) are a broad group of organic salts of varying structure and properties, used in energy conversion and storage, chemical analysis, separation processes, as well as in the preparation of particles in nano- and microscale. In material engineering, ionic liquids are applied to synthesize mainly metal nanoparticles and 3D semiconductor microparticles. They could generally serve as a structuring agent or as a reaction...
-
Novel Biomass-Based Polymers: Synthesis, Characterization, and Application
PublicationA wide range of polymers were prepared from biomass-derivatives, using different polymerization mechanisms. Well-defined, fully hydroxy-functional polyesters based on aliphatic diols were synthesized, using either conventional metal-based catalysts or the organic superbase 1,5,7-triazabicyclododecene (TBD). Unsaturated polyesters were also made, offering additional functionality to these biobased resins. Metal-catalyzed or enzymatic...
-
X-Ray Computer Tomography Study of Degradation of the Zircaloy-2 Tubes Oxidized at High Temperatures
PublicationThe investigations of high-temperature oxidation of zirconium alloys, applied for fuel pellets in nuclear power plants, are usually limited to oxidation kinetics, phase transformations and microstructural characterization. The purpose of this research was to characterize the degradation phenomena occurring within oxide layer and at the interface oxide/metal, on internal and external Zircaloy-2 tube...
-
Monitoring Lead Concentration in the Surrounding Environmental Components of a Lead Battery Company: Plants, Air and Effluents—Case Study, Kenya
PublicationLead (Pb) pollution from smelters and lead–acid battery has become a serious problem worldwide owing to its toxic nature as a heavy metal. Stricter regulations and monitoring strategies have been formulated, legislated and implemented in various parts of the world on heavy metal usage. Developed countries such as the USA and in Europe largely operate within the set standards, however, developing countries such as Kenya, Nigeria...
-
Synteza i badania strukturalne związków kompleksowych miedzi(I) i rtęci(II) z wybranymi ligandami tioamidowymi
PublicationPrzedstawiona rozprawa doktorska poświęcona jest związkom tiokarbonylowym (wybranym tioamidom i tiomocznikom) oraz ich połączeniom kompleksowym z halogenkami miedzi(I) i rtęci(II). Istota i cel takich badań przedstawione są we wstępie pracy. W części teoretycznej opisane zostały kluczowe pierwiastki wchodzące w skład syntezowanych związków kompleksowych (siarka, miedź i rtęć), jak również tioamidy i tiomoczniki. Szczególna uwaga...
-
Badania stanu technicznego ścianek szczelnych strony południowej i północnej komory południowej śluzy Dzierżno
PublicationPrace dotyczyły badań nieniszczących łączników (zamków) Paine`a oraz ścianek szczelnych. Ściany boczne komory południowej śluzy Dzierżno zbudowane są ze stalowych pasów blachy o grubości około 16mm i długości 22m połączonych ze sobą wzdłuż dłuższej krawędzi za pomocą zamków Peine`a. System ten umożliwia uzyskanie szczelnego połączenia na całej długości ścianki. Zaawansowany proces korozji spowodował rozszczelnienie połączenia...
-
THE EFFECT OF WET UNDERWATER WELDING ON COLD CRACKING SUSCEPTIBILITY OF DUPLEX STAINLESS STEEL
PublicationABSTRACT The present work was conducted to assess the weldability of duplex stainless steel in underwater conditions. Metal manual arc welding (MMA) with the use of coated electrodes was used in the investigations. Tekken weldability tests were performed underwater at 0.5 m depth and in the air. Nondestructive tests, metallographic examinations of welds, ferrite content assessment in microstructure and hardness test were performed....
-
Partitioning of heavy metals in sub-surface flow treatment wetlands receiving high-strength wastewater
PublicationThe retention of heavy metals at two pilot-scale treatment wetlands (TWs), consisting of two vertical flow beds (VSSF) followed by a horizontal flow bed (HSSF) was studied. The TWs received highstrength wastewater: reject waters from sewage sludge centrifugation (RW) and landfill leachate (LL). The concentrations of metals: Fe, Mn, Zn, Al, Pb, Cu, Cd, Co, Ni were measured in treated wastewater, substrate of the beds and in plant...
-
A new B-D-galactosidase with a low temperature optimum isolated from the Antarctic Arthrobacter sp. 20B: gene cloning, purification and characterization.
PublicationA psychrotrophic bacterium producing a coldadaptedB-galactosidase upon growth at low temperatureswas classiWed as Arthrobacter sp. 20B. A genomic DNAlibrary of strain 20B introduced into Escherichia coliTOP10F' and screening on X-Gal (5-bromo-4-chloro-3-indolyl-B-D-galactopyranoside)-containing agar plates ledto the isolation of B-galactosidase gene. The B-galactosidasegene (bgaS) encoding a protein of 1,053 amino acids,with a...
-
THE ANALYSIS OF THE INFLUENCE OF STRESS DISTRIBUTION ON WEAR PROFILE IN LUBRICATED SLIDING CONTACT OF UHMW-PE VS TITANIUM Ti-13Nb-13Zr ALLOY
PublicationMetal – polymer sliding contacts are a typical combination in industry and medicine. For decades such a set of materials has been the primary choice in human joints endoprosthetic technology. In this paper tribological issues of are presented from a research on the potential for practical use of Ti-13Nb-13Zr/UHMW-PE couple for orthopedic endoprosthesis. In tests on simplified models it is critically important to carefully...
-
The abrasive wear resistance of coatings manufactured on high-strength low-alloy (HSLA) offshore steel in wet welding conditions
PublicationSome marine and offshore structure elements exploited in the water cannot be brought to the surface of the water as this will generate high costs, and for this reason, they require in-situ repairs. One of the repair techniques used in underwater pad welding conditions is a wet welding method. This paper presents an investigation of the abrasive wear resistance of coatings made in wet welding conditions with the use of two grades...
-
Artificial neural network prophecy of ion exchange process for Cu (II) eradication from acid mine drainage
PublicationThe removal of heavy metal ions from wastewater was found to be significant when the cation exchange procedure was used effectively. The model of the cation exchange process was built using an artificial neural network (ANN). The acid mine drainage waste’s Cu(II) ion was removed using Indion 730 cation exchange resin. Experimental data from 252 cycles were recorded. In a column study, 252 experimental observations validated the...
-
Catalytic Activity of Nickel and Ruthenium–Nickel Catalysts Supported on SiO2, ZrO2, Al2O3, and MgAl2O4 in a Dry Reforming Process
PublicationDry reforming of methane (DRM) is an eco-friendly method of syngas production due to the utilization of two main greenhouse gases—methane and carbon dioxide. An industrial application of methane dry reforming requires the use of a catalyst with high activity, stability over a long time, and the ability to catalyze a reaction, leading to the needed a hydrogen/carbon monoxide ratio. Thus, the aim of the study was to investigate the...
-
Electrochemistry from first-principles in the grand canonical ensemble
PublicationProgress in electrochemical technologies, such as automotive batteries, supercapacitors, and fuel cells, depends greatly on developing improved charged interfaces between electrodes and electrolytes. The rational development of such interfaces can benefit from the atomistic understanding of the materials involved by first-principles quantum mechanical simulations with Density Functional Theory (DFT). However, such simulations are...
-
Cu( II ) ions removal from wastewater using starch nanoparticles ( SNPs ): An Eco‐sustainable approach
PublicationThe complex structured starch particles were reduced to the nanoscale size range through hydrolysis utilizing low concentration acid assisted with ultrasound irradiation. The synthesized starch nanoparticles (SNPs) were characterized by TEM, FTIR, and XRD techniques. The synthesized SNPs possessed surface activated entities, as many cationic functional groups were confirmed through the FTIR spectrum. Also, these SNPs were effectively...
-
The Effect of Sterols on Amphotericin B Self-Aggregation in a Lipid Bilayer as Revealed by Free Energy Simulations
PublicationAmphotericin B (AmB) is an effective but toxic antifungal drug, known to increase the permeability of the cell membrane, presumably by assembling into transmembrane pores in a sterol-dependent manner. The aggregation of AmB molecules in a phospholipid bilayer is, thus, crucial for the drug’s activity. To provide an insight into the molecular nature of this process, here, we report an atomistic molecular dynamics simulation study...
-
Specific Binding of Cholesterol to the Amyloid Precursor Protein: Structure of the Complex and Driving Forces Characterized in Molecular Detail
PublicationC99 is the C-terminal membrane-bound fragment of the amyloid precursor protein that is cleaved by γ-secretase to release Aβ peptides, the hallmark of Alzheimer’s disease (AD). Specific interactions of C99 with cholesterol have been proposed to underlie the recognized role of cholesterol in promoting amyloidogenesis. By using molecular dynamics simulations, we studied cholesterol binding to C99 in a lipid bilayer. We determined...
-
Chemical composition, antioxidant and anticancer effects of the seeds and leaves and indigo (polygonum tinctorium Ait.) Plant
PublicationSeeds and leaves of indigo (Polygonum tinctorium Ait.) plant were investigated and compared with another medicinal plant named prolipid for their properties such as chemical composition, antioxidant, and anticancer effects by Fourier transform infrared, three-dimensional fluorescence spectroscopy, and electrospray ionization-MS in negative mode. It was found that polyphenols, flavonoids, and flavanols were significantly higher...
-
Preparation of Allyl Alcohol Oligomers Using Dipicolinate Oxovanadium(IV) Coordination Compound
PublicationCurrently, new precatalysts for olefin oligomerization are being sought in the group of vanadium(IV) complexes. Thus, the aim of our research was to examine the catalytic activity of the oxovanadium(IV) dipicolinate complex [VO(dipic)(H2O)2] 2 H2O (dipic = pyridine-2,6-dicarboxylate anion) in 2-propen-1-ol oligomerization as well as to characterize oligomerization products using matrix-assisted laser desorption/ionization–time-of-flight...
-
Synthesis and application of tetrazole di and triamide derivatives in ion-selective membrane electrodes
PublicationA number of tetrazole diamides and triamides have been synthesized and applied as ion carries in ion-selective membrane electrodes. Their selectivity and sensitivity were studied towards alkali, alkaline earth, transition and heavy metal cations. it was found that membranes doped with 3 and 2-nitrophenyl octyl ether exhibit an almost theoretial Nernstian response for NH+ over relatively wide concentration range. Elestrodes with...
-
Synthesis and properties of new 'N,'N-phenyltetrazole podand
PublicationThe synthesis of a new chromogenic N,N-phenyltetrazole receptor is reported here. The cationbinding properties of this receptor in solution were investigated by naked-eye colour change, electrochemical methods and UV-Vis spectroscopy in various solvents (CH3CN, dimethylsulphoxide (DMSO), DMSO/H2O, CH3CN/H2O and CH3CN/MeOH). In addition, the receptor was used as a sensing material in ion-selective membrane electrodes. The selectivity...
-
Assessment of copper surface coverage with corrosion inhibitor using AFM-based local electrical measurements
PublicationThe paper presents a new method of assessment of metal surface coverage with corrosion inhibitor and thus of inhibitor protective performance. It is based on the atomic force microscopy measurement performed in a contact mode. Apart from topography images the proposed approach allows acquisition of local DC maps and local electrical impedance spectra via application of DC bias voltage or AC perturbation signal between the conductive...
-
9 - Solid oxide fuel and electrolysis cells
PublicationIn this chapter, the fundamental reactions, the geometrical designs, the material requirements, and the status of SOFCs and SOECs are presented. In the following seven chapters, the most important components of an SOC are described and the chapter ends with a summary and outlook. The described components are: (i) oxygen-ion conductors (electrolyte), (ii) anode materials for SOFCs (cathode in SOEC mode), (iii) cathode materials...
-
Identification and cloning of C. albicans SC5314 genes encoding L-methionine biosynthetic pathway enzymes.
Open Research DataEnzymes of fungal L-methionine biosynthetic pathway: homoserine O-acetyltransferase (Met2p), O-acetylhomoserine sulfhydrylase (Met15p) and cystathionine-γ-synthase (Str2p) could be exploited as molecular targets for antifungal chemotherapy. The goal of the study was to identify and clone genes encoding mentioned above enzymes. MET2, MET15 and STR2 genes...
-
Potential changes in an electric field and electrolytic corrosion.
PublicationSources have been described of corrosively hazardous electric fields and methods of determination of the corrosion hazard to metal structures caused by electrolytic corrosion. Results of potential and impedance investigations in the field of stray currents flowing out of a tram traction and in the presence of a defined electric field of low frequency have been presented. Uncertainties have been indicated relating to the generally...
-
Geometrically Nonlinear Analysis of Functionally Graded Shells Based on 2-D Cosserat Constitutive Model
PublicationIn this paper geometrically nonlinear analysis of functionally graded shells in 6-parameter shell theory is presented. It is assumed that the shell consists of two constituents: ceramic and metal. The mechanical properties are graded through the thickness and are described by power law distribution. Formulation based on 2-D Cosserat constitutive model is used to derive constitutive relation for functionally graded shells. Numerical...
-
Naval mine detection system based of FPGA circuit
PublicationElectrochemical processes take place in a metal object immersed into sea water even if an anticorrosive coating is applied [1]. As a result, flowing field appears around the object. There are naval mines between many other objects situated in the sea. Naval mines can be put in the seabed in order to be more difficult to detect by sonars. Such a mine is located on the line demarking two environments of different electrical conductivity....
-
Design of Microwave Lossy Filter Based on Substrate Integrated Waveguide (SIW)
PublicationIn this letter, we propose a lossy three-pole Chebyshev filter centered at 5.15 GHz, based on the substrate integrated waveguide (SIW) with scattering characteristics shifted down by 5.68 dB. The filter is composed of three directly coupled SIW cavities with three lossy couplings between nonadjacent resonators. These additional couplings are realized using mixed coupled slot and microstrip lines connected with metal electrode leadless...
-
Antioxidant properties of ferrous flavanol mixtures
PublicationInteraction of metal, especially iron ions with flavanols is considered as an important feature of these compounds and is believed to contribute to their both antioxidant and prooxidant properties. The aim of this study was to examine how Fe2+ binding to form a 4:1 (flavanol:Fe2+) mixtures affects the antioxidant properties of flavanols. ABTS∗ scavenging, protection against fluorescence bleaching induced by AAPH and hypochlorite,...
-
The field–dependent interface recombination velocity for organic–inorganic heterojunction
PublicationWe have derived an analytical formula which describes the field–dependent interface recombination velocity for the boundary of two materials characterized by different permittivities. The interface recombination of charge carriers has been considered in the presence of image force Schottky barrier. We suggest that this effect may play an important role in the loss of current for organic–inorganic hybrid heterojunctions. It has...
-
Quenching of bright and dark excitons via deep states in the presence of SRH recombination in 2D monolayer materials
PublicationTwo-dimensional (2D) monolayer materials are interesting systems due to an existence of optically non-active dark excitonic states. In this work, we formulate a theoretical model of an excitonic Auger process which can occur together with the trap-assisted recombination in such 2D structures. The interactions of intravalley excitons (bright and spin-dark ones) and intervalley excitons (momentum-dark ones) with deep states located...
-
Distribution and removal efficiency of heavy metals in two constructed wetlands treating landfill leachate
PublicationThe results of heavy metals (Fe, Mn, Zn, Ni, Cu, Cr, Pb, Cd) removal and partitioning between aqueous and solid phases at two wetlands (TWs) treating municipal landfill leachates are presented. One of the TWs is a surface flow facility consisting of 10 ponds. The other TW is a newly constructed pilot-scale facility consisting of three beds with alternately vertical and horizontal sub-surface flow. The metals concentrations were...
-
Drug-resistant and hospital-associated Enterococcus faecium from wastewater, riverine estuary and anthropogenically impacted marine catchment basin.
PublicationEnterococci, ubiquitous colonizers of humans and other animals, play an increasingly important role in health-care associated infections (HAIs). Acquisition of resistance determinants not only seriously limits available therapeutic options but also increases available gene pool for other species. It is believed that the recent evolution of two clinically relevant species, Enterococcus faecalis and Enterococcus faecium occurred...
-
Anomalous Behavior of Hyaluronan Crosslinking Due to the Presence of Excess Phospholipids in the Articular Cartilage System of Osteoarthritis
PublicationLubrication of articular cartilage is a complex multiscale phenomenon in synovial joint organ systems. In these systems, synovial fluid properties result from synergistic interactions between a variety of molecular constituent. Two molecular classes in particular are of importance in understanding lubrication mechanisms: hyaluronic acid and phospholipids. The purpose of this study is to evaluate interactions between hyaluronic acid...
-
DMSO and TMAO—Differences in Interactions in Aqueous Solutions of the K-Peptide
PublicationInteractions between a solvent and their co-solute molecules in solutions of peptides are crucial for their stability and structure. The K-peptide is a synthetic fragment of a larger hen egg white lysozyme protein that is believed to be able to aggregate into amyloid structures. In this study, a complex experimental and theoretical approach is applied to study systems comprising the peptide, water, and two co-solutes: trimethylamide...
-
Quantitative fluorescent determination of DNA – Ochratoxin a interactions supported by nitrogen-vacancy rich nanodiamonds
PublicationOchratoxin A (OTA) is a hazardous contaminant of a large variety of plant and animal originated food. Herein, we report an interaction of OTA with calf thymus DNA (ct DNA) on the nanodiamond surface. We employed multispectroscopic techniques to elucidate the binding mechanism of OTA with ct DNA. The fluorescence and UV–Vis spectroscopy results show that OTA binds to ds ct DNA and forms complexes. We obtained the binding constants...
-
A Rapid and Simple Method for Screening Microorganisms with a Potential for Catechol Biodegradation
PublicationCatechol is a highly toxic compound that is also a key intermediate in biodegradation pathways of various aromatic compounds. In this paper, a new screening method for isolation of microorganisms with the potential for catechol biodegradation is reported. The method described is based on the ability of catechol to form a color complex with Fe3+ ions. For this purpose, basal medium that is widely used for classification of microorganisms...
-
Survey on fuzzy logic methods in control systems of electromechanical plants
PublicationРассмотрены алгоритмы управления электромеханическими системами с использованием теории нечеткой логики, приводятся основные положения их синтеза, рассматриваются методы анализа их устойчивости на основе нечетких функций Ляпунова. Эти алгоритмы чаще всего реализуются в виде различных регуляторов, применение которых целесообразно в системах, математическая модель которых не известна, не детерминирована или является строго нелинейной,...
-
Architektura przyjazna seniorom w Polsce XXI wieku. Kształtowanie przestrzeni zamieszkania, pracy i rozrywki
PublicationPolska, podobnie jak wiele innych krajów, zmaga się obecnie z procesem starzenia społeczeństwa, który w najbliższych latach będzie przybierał na sile. Dlatego bardzo istotne jest, aby już teraz rozpocząć proces przystosowywania miast do zmieniającej się struktury społecznej, tak aby w przyszłości mogły być one miejscem, w którym ludzie starsi będą mogli swobodnie i bezpiecznie mieszkać oraz funkcjonować. W realiach polskich można...
-
Effect of Arc Strikes on High Strength Low Alloy Steels Welded by SMAW
PublicationWet welding with covered electrodes (Shielded Metal Arc Welding – SMAW) is the most commonly used method of carrying out welding repair works in a water environment. Limited visibility and the inability to move freely under water result in an increased risk of formation of welding imperfections such as lack of fusion, lack of penetration and arc strikes. The work focused on changes in the properties and structure of steel subjected...
-
Influence of Different Nanometals Implemented in PMMA Bone Cement on Biological and Mechanical Properties
PublicationCemented arthroplasty is a common process to fix prostheses when a patient becomes older and his/her bone quality deteriorates. The applied cements are biocompatible, can transfer loads, and dampen vibrations, but do not provide antibacterial protection. The present work is aimed at the development of cement with antibacterial effectivity achieved with the implementation of nanoparticles of different metals. The powders of Ag,...
-
Highly Dissipative Materials for Damage Protection against Earthquake-Induced Structural Pounding
PublicationIt is a common situation that seismic excitations may lead to collisions between adjacent civil engineering structures. This phenomenon, called earthquake-induced structural pounding, may result in serious damage or even the total collapse of the colliding structures. Filling the gap between two buildings erected close to one another by using visco-elastic materials can be considered to be one of the most effective methods to avoid...
-
Chromogenic macrocyclic derivatives of azoles - synthesis and properties,
PublicationNew azocrown ethers comprising imidazoles in the macrocycle have been synthesized. Imidazole, 2-methyl-, 4-methyl-, and 4-phenylimidazole were incorporated to form macrocyclic units by coupling with the appropriate bis-diazonium salts. The syntheseswere performed under high dilution conditions. The X-ray structure of a water adduct of the 21-membered crown ether derivative of 4-methylimidazole 8 has been solved. Metal...
-
Operation of reed systems used to stabilization of sewage sludge
PublicationThe aim of this research was to determine the parameters of property operation of reed systems. It was also checked the possibility to use sludge in agriculture for the sake of heavy metal concentrations.The research was conducted in four Danish objects utilized sludge located in Helsinge, Vallo, Rudkobing and Nakskov near Copenhagen.It was found that correct operation of reed basins requires the determination of optimal doses...
-
Superconducting properties and electronic structure of NaBi
PublicationResistivity, dc magnetization, and heat capacity measurements are reported for superconducting NaBi. Tc, the electronic contribution to the specific heat γ, the ΔCp/γTc ratio, and the Debye temperature are found to be 2.15 K, 3.4 mJ mol−1 K−2, 0.78, and 140 K respectively. The calculated electron–phonon coupling constant (λep = 0.62) implies that NaBi is a moderately coupled superconductor. The upper critical field and coherence...