Structure of quantum disordered wave functions: weak localization, far tails, and mesoscopic transport

We report on the comprehensive numerical study of the fluctuation and correlation properties of wave functions in three-dimensional mesoscopic diffusive conductors. Several large sets of nanoscale samples with finite metallic conductance, modeled by an Anderson model with different strengths of diagonal box disorder, have been generated in order to investigate both small and large deviations (as well as the connection between them) of the distribution function of eigenstate amplitudes from the universal prediction of random matrix theory. We find that small, weak localization-type, deviations contain both diffusive contributions (determined by the bulk and boundary conditions dependent terms) and ballistic ones which are generated by electron dynamics below the length scale set by the mean free path ell. By relating the extracted parameters of the functional form of nonperturbative deviations (``far tails'') to the exactly calculated transport properties of mesoscopic conductors, we compare our findings based on the full solution of the Schrodinger equation to different approximative analytical treatments. We find that statistics in the far tail can be explained by the exp-log-cube asymptotics (convincingly refuting the log-normal alternative), but with parameters whose dependence on ell is linear and, therefore, expected to be dominated by ballistic effects. It is demonstrated that both small deviations and far tails depend explicitly on the sample size--the remaining puzzle then is the evolution of the far tail parameters with the size of the conductor since short-scale physics is supposedly insensitive to the sample boundaries.Comment: 13 pages, 9 embedded EPS figures, expanded discussion (with extra one figure) on small size effec

Aktivna oksidna prevlaka na titanu dobijena sol-gel postupkom kao anoda za katodnu zaštitu u morskoj vodi

The characteristics of a ternary oxide coating, on titanium, which consisted of TiO2, RuO2 and IrO2 in the molar ratio 0.6:0.3:0.1, calculated on the metal atom, were investigated for potential application for cathodic protection in a seawater environment. The oxide coatings on titanium were prepared by the sol-gel procedure from a mixture of inorganic oxide sols, which were obtained by forced hydrolysis of metal chlorides. The morphology of the coating was examined by scanning electron microscopy. The electrochemical properties of activated titanium anodes were investigated by cyclic voltammetry and polarization measurements in a H2SO4- and NaCl-containing electrolyte, as well as in seawater sampled on the Adriatic coast in Tivat, Montenegro. The anode stability during operation in seawater was investigated by the galvanostatic accelerated corrosion stability test. The morphology and electrochemical characteristics of the ternary coating are compared to that of a sol-gel-prepared binary Ti0.6Ru0.4O2 coating. The activity of the ternary coating was similar to that of the binary Ti0.6Ru0.4O2 coating in the investigated solutions. However, the stability in seawater is found to be considerably greater for the ternary coating.Karakteristike trojne oksidne prevlake na titanu, koja se sastoji od TiO2, RuO2 i IrO2 u molskom odnosu 0.6:0.3:0.1 računato na atom metala, ispitivane su sa ciljem potencijalne primene za katodnu zaštitu u morskoj vodi. Oksidna prevlaka na titanu formirana je sol-gel postupkom iz smeše neorganskih oksidnih solova, koji su dobijeni forsiranom hidrolizom hlorida metala. Morfologija prevlake je ispitivana skenirajućom elektronskom mikroskopijom, dok su elektrohemijska svojstva aktiviranih titankih anoda ispitivana metodom ciklične voltametrije i polarizacionim merenjima u rastvorima H2SO4, NaCl i u realnim uslovima, u morskoj vodi uzorkovanoj iz Jadranskog mora (Tivat, Crna Gora). Stabilnost anode tokom rada u morskoj vodi ispitivana je galvanostatski, ubrzanim testom stabilnosti. Dobijene prevlake upoređene su sa dvojnom Ti0,6Ru0,4O2 prevlakom, u pogledu morfologije i elektrohemiskih karakteristika. Pokazano je da su trojna i dvojna prevlaka slične aktivnosti u ispitivanim rastvorima. Međutim, u morskoj vodi stabilnost trojne prevlake je znatno veća

Titanske anode aktivirane oksidnom prevlakom dobijenom sol-gel postupkom

The properties of activated titanium anodes, RuO2-TiO2/Ti and RuO2--TiO2-IrO2/Ti, prepared from oxide sols by the sol-gel procedure, are reviewed. RuO2 and TiO2 sols were synthesized by forced hydrolysis of the corresponding chlorides in acid medium. The morphology of the prepared sols was investigated by transmission electron microscopy. The chemical composition of the RuO2 sol was determined by X-ray diffraction and thermogravimetric analysis. The loss of electrocatalytic activity of a RuO2-TiO2/Ti anode during an accelerated stability test was investigated by examination of the changes in the electrochemical characteristics in the potential region of the chlorine and oxygen evolution reaction, as well as on the open circuit potential. These electrochemical characteristics were investigated by cyclic voltammetry, electrochemical impedance spectroscopy and polarization measurements. The changes in electrochemical characteristics of the anode prepared by the sol-gel procedure were compared to the changes registered for an anode prepared by the traditional thermal decomposition of metal chlorides. The comparison indicated that the main cause for the activity loss of the sol-gel prepared anode was the electrochemical dissolution of RuO2, while in the case of thermally prepared anode the loss was mainly caused by the formation of an insulating TiO2 layer in the coating/Ti substrate interphase. The results of an accelerated stability test on RuO2-TiO2/Ti and RuO2--TiO2-IrO2/Ti anodes showed that the ternary coating is considerably more stable than the binary one, which is the consequence of the greater stability of IrO2 in comparison to RuO2.U radu je dat je pregled svojstava aktiviranih titanskih anoda, RuO2-TiO2/Ti i RuO2--TiO2-IrO2/Ti, dobijenih sol-gel postupkom od neorganskih oksidnih solova. RuO2 i TiO2 solovi dobijeni su forsiranom hidrolizom odgovarajućih hlorida metala u kiseloj sredini. Morfologija dobijenih solova ispitivana je transmisionom elektronskom mikroskopijom. Hemijski sastav RuO2 sola ispitivan je difrakcijom x-zraka i termogravimetrijskom analizom. Mehanizam gubitka elektrokatalitičke aktivnosti RuO2-TiO2/Ti anoda ispitivan je praćenjem promena elektrohemijskih svojstava anode u reakcijama izdvajanja hlora i kiseonika, kao i na potencijalu otvorenog kola, tokom degradacije anode. Ove elektro-hemijske karakteristike anode ispitivane su metodama ciklične voltametrije, spektroskopije elektrohemijske impedancije i polarizacionim merenjima. Promene u elektrohemijskim svojstvima anode dobijene sol-gel postupkom poređene su sa promenama koje su registrovane za RuO2-TiO2/Ti anodu dobijenu tradicionalnim postupkom termičke razgradnje hlorida metala. Na osnovu ovih ispitivanja proizilazi da je osnovni uzrok gubitka elektrokatalitičke aktivnosti anode dobijene sol-gel postupkom elektrohemijsko rastvaranje RuO2, dok je uzrok degradacije anode dobijene termičkom razgradnjom rast neprovodnog TiO2 sloja u međufazi prevlaka/titanska podloga. Rezultati ubrzanog testa stabilnosti RuO2-TiO2/Ti i RuO2-TiO2-IrO2/Ti anode pokazuju da je trojna prevlaka znatno stabilnija od dvojne, zbog veće stabilnosti oksida iridijuma u poređenju sa oksidom rutenijuma

Photoelectrochemical properties of sol–gel obtained titanium oxide

The photoelectrochemical properties of a sol–gel prepared titanium oxide coating applied onto a Ti substrate were investigated. The oxide coating was formed from an inorganic sol thermally treated in air at 350 °C. The coating consisted of agglomerates of narrow size distribution around 100 nm. The photoelectrochemical characteristics were evaluated by investigating the changes in the open circuit potential, current transients and impedance characteristics of a Ti/TiO2 electrode upon illumination by UV light in H2SO4 solution and in the oxidation of benzyl alcohol. The electrode was found to be active for photoelectrochemical reactions in the investigated solutions

Electrocatalytic properties and stability of titanium anodes activated by the inorganic sol–gel procedure

The properties of activated titanium anodes, RuO2–TiO2/Ti and RuO2–TiO2–IrO2/Ti, prepared from oxide sols by the sol–gel procedure, are reviewed. RuO2 and TiO2 sols were synthesized by forced hydrolysis of the corresponding chlorides in acid medium. The morphology of the prepared sols was investigated by transmission electron microscopy. The chemical composition of the RuO2 sol was determined by X-ray diffraction and thermogravimetric analysis. The loss of electrocatalytic activity of a RuO2–TiO2/Ti anode during an accelerated stability test was investigated by examination of the changes in the electrochemical characteristics in the potential region of the chlorine and oxygen evolution reaction, as well as on the open circuit potential. These electrochemical characteristics were investigated by cyclic voltammetry, electrochemical impedance spectroscopy and polarization measurements. The changes in electrochemical characteristics of the anode prepared by the sol–gel procedure were compared to the changes registered for an anode prepared by the traditional thermal decomposition of metal chlorides. The comparison indicated that the main cause for the activity loss of the sol–gel prepared anode was the electrochemical dissolution of RuO2, while in the case of thermally prepared anode the loss was mainly caused by the formation of an insulating TiO2 layer in the coating/Ti substrate interphase. The results of an accelerated stability test on RuO2–TiO2/Ti and RuO2–TiO2–IrO2/Ti anodes showed that the ternary coating is considerably more stable than the binary one, which is the consequence of the greater stability of IrO2 in comparison to RuO2

Intrinsic Potential-Dependent Performances of a Sol-Gel-Prepared Electrocatalytic IrO2-TiO2 Coating of Dimensionally Stable Anodes

The electrochemical properties of a sol-gel-prepared IrO2-TiO2 coating on Ti were investigated from the standpoint of the charging/discharging behavior in 1.0A degrees mol dm(-3) H2SO4 and in 0.50A degrees mol dm(-3) NaCl, pH 2. The potential-dependent changes from low oxidation states of Ir, with low activity, to those of higher activity (enhanced pseudocapacitive performances) were analyzed at different charging/discharging rates by cyclic voltammetry and electrochemical impedance spectroscopy. The results showed the distribution of Ir oxidation states through the coating, with lower ones being placed largely in the internal, hardly accessible, parts of the coating. The transition to higher oxidation states appears as crucial for the full development of pseudocapacitive performances. This transition occurs much easier in the NaCl than in the H2SO4 solution, since the potentials of redox transitions of Ir are much closer due to lower hydrogen ion concentration in NaCl solution. As a consequence, a unique overall coating capacitance was registered in both solutions

The electro-oxidation of the mixture of formaldehyde and 2-propanol on gold (100) and (111) single crystal planes in alkaline medium

The effect of formaldehyde on the oxidation of 2-propanol and vice versa on gold single crystal planes (100 and 111) was studied. An activating effect in the reaction of the simultaneous oxidation of 2-propanol and formaldehyde was obtained on a gold (100) plane. In the case of a gold (111) electrode, the activation effect was not obtained. It was concluded that the adsorption of formaldehyde on the electrode surface prevents the adsorption of poisoning species formed during the electro-oxidation of 2-propanol on the Au(100) plane, while this is not the case on the Au(111) plane. The different behaviour is caused by the difference in the symmetry of the surface atoms of these two Au single-crystal planes

The Significance of COVID-19 Diseases in Lipid Metabolism Pregnancy Women and Newborns

Coronavirus disease (COVID-19) is an infectious disease caused by SARS-CoV-2. Elderly people, people with immunodeficiency, autoimmune and malignant diseases, as well as people with chronic diseases have a higher risk of developing more severe forms of the disease. Pregnant women and children can becomesick, although more often they are only the carriers of the virus. Recent studies have indicated that infants can also be infected by SARS-CoV-2 and develop a severe form of the disease with a fatal outcome. Acute Respiratory Distress Syndrome (ARDS) ina pregnant woman can affect the supply of oxygen to the fetus and initiate the mechanism of metabolic disorders of the fetus and newborn caused by asphyxia. The initial metabolic response of the newborn to the lack of oxygen in the tissues is the activation of anaerobic glycolysis in the tissues and an increase in the concentration of lactate and ketones. Lipid peroxidation, especially in nerve cells, is catalyzed by iron released from hemoglobin, transferrin and ferritin, whose release is induced by tissue acidosis and free oxygen radicals. Ferroptosis-inducing factors can directly or indirectly affect glutathione peroxidase through various pathways, resulting in a decrease in the antioxidant capacity and accumulation of lipid reactive oxygen species (ROS) in the cells, ultimately leading to oxidative cell stress, and finally, death. Conclusion: damage to the mitochondria as a result of lipid peroxidation caused by the COVID-19 disease can cause the death of a newborn and pregnant women as well as short time and long-time sequelae

Multi-strange baryon production in pp collisions at √s=7 TeV with ALICE

A measurement of the multi-strange Ξ− and Ω− baryons and their antiparticles by the ALICE experiment at the CERN Large Hadron Collider (LHC) is presented for inelastic proton–proton collisions at a centre-of-mass energy of 7 TeV. The transverse momentum (pT) distributions were studied at mid-rapidity (|y|6.0 GeV/c. We also illustrate the difference between the experimental data and model by comparing the corresponding ratios of (Ω−+Ω¯+)/(Ξ−+Ξ¯+) as a function of transverse mass