Structural and Electrical Properties of Sintered Zinc-titanate Ceramics

Poster presented at the ELECTROCERAMICS X, June 18-22, 2006, Toledo, Spai

Energy loss distributions of 7 TeV protons channeled in a bent silicon crystals

The energy loss distributions of relativistic protons axially channeled through the bent <100> Si crystals, with the constant curvature radius, R = 50 m, are studied here. The proton energy is 7 TeV and the thickness of the crystal is varied from 1 mm to 5 mm, which corresponds to the reduced crystal thickness, L, from 2.1 to 10.6, respectively. The proton energy was chosen in accordance with the large hadron collider project, at the European Organization for Nuclear Research, in Geneva, Switzerland. The energy loss distributions of the channeled protons were generated by the computer simulation method using the numerical solution of the proton equations of motion in the transverse plane. Dispersion of the proton scattering angle caused by its collisions with the crystal’s electrons was taken into account. [Projekat Ministarstva nauke Republike Srbije, br. III 45006

Quantum Rainbows in Positron Transmission through Carbon Nanotubes

Here we report the results of the theoretical investigation of the transmission of channeled positrons through various short chiral single walled carbon nanotubes (SWCNT). The main question answered by this study is “What are the manifestations of the rainbow effect in the channeling of quantum particles that happens during the channeling of classical particles?” To answer this question, the corresponding classical and quantum problems were solved in parallel, critically examined, and compared with each other. Positron energies were taken to be 1 MeV when the quantum approach was necessary. The continuum positron-nanotube potential was constructed from the thermally averaged Molière’s positron-carbon potential. In the classical approach, a positron beam is considered as an ensemble of noninteracting particles. In the quantum approach, it is considered as an ensemble of noninteracting wave packages. Distributions of transmitted positrons were constructed from the numerical solutions of Newton’s equation and the time-dependent Schrödinger equation. For the transmission of 1-MeV positrons through 200-nm long SWCNT (14; 4), in addition to the central maximum, the quantum angular distribution has a prominent peak pair (close to the classical rainbows) and two smaller peaks pairs. We have shown that even though the semiclassical approximation is not strictly applicable it is useful for explanation of the observed behavior. In vicinity of the most prominent peak, i.e., the primary rainbow peak, rays interfere constructively. On one of its sides, rays become complex, which explains the exponential decay of the probability density in that region. On the other side, the ray interference alternates between constructive and destructive, thus generating two observed supernumerary rainbow peaks. The developed model was then applied for the explanation of the angular distributions of 1-MeV positrons transmitting through 200 nm long (7, 3), (8, 5), (9, 7), (14, 4), (16, 5) and (17, 7) SWCNTs. It has been shown that this explains most but not all rainbow patterns. Therefore, a new method for the identification and classification of quantum rainbows was developed relying only on the morphological properties of the positron wave function amplitude and the phase function families. This led to a detailed explanation of the way the quantum rainbows are generated. All wave packets wrinkle due to their internal focusing in a mutually coordinated way and are concentrated near the position of the corresponding classical rainbow. This explanation is general and applicable to the investigations of quantum effects occurring in various other atomic collision processes

Zn/Au alloys formation by Zn electrodeposition from a deep eutectic system

The electrochemical deposition of Zn onto Au from a choline chloride/ethylene glycol deep eutectic system containing different ZnCl2 concentrations has been investigated. The voltammetric results demonstrated that Zn electrodeposition commences in the zinc underpotential deposition (UPD) and proceeds through to the zinc overpotential deposition (OPD) region. The results of X-ray diffraction analysis revealed that the deposit prepared at a relatively low Zn overpotential of – 0.050 V vs. Zn was composed of cubic AuZn alloy. The morphology of the deposit has been characterized by means of a scanning electron microscope and displays a relatively compact and dendrite-free Zn/Au alloy deposit formed

Beneficial effects of pomegranate peel extract on plasma lipid profile, fatty acids levels and blood pressure in patients with diabetes mellitus type-2: A randomized, double-blind, placebo-controlled study

Pomegranate peel contains high levels of various phytochemicals. We evaluated the effects of pomegranate peel extract (PoPEx) consumption on plasma lipid profile, fatty acids (FA) level and blood pressure (BP) in patients with diabetes mellitus type 2 (DMT2). Thirty-seven subjects were recruited in this double blind, placebo controlled randomized trial. The study group (n = 19) received over 8 week's capsules containing PoPEx twice a daily, while the placebo group received placebo. Treatment with PoPEx induced a significant lowering of both systolic and diastolic BP. The plasma levels of triglycerides, low-density lipoprotein cholesterol/high-density lipoprotein cholesterol ratio (LDL-C/HDL-C), and HbA1c were significantly decreased, while the level of HDL-C was significantly increased, compared with placebo intake. Moreover, the PoPEX treatment significantly improved the plasma lipids fatty acids content. It is concluded that consumption of PoPEx in DMT2 subject had favourable effects on some metabolic parameters, BP, lipid profile and plasma lipid FA composition

Structural, Mechanical, and Barrier Properties of the Polyvinylidene Fluoride-Bacterial Nanocellulose-Based Hybrid Composite

This study presents an analysis of films which consist of two layers; one layer is PVDF as the matrix, along with fillers BaTiO3 (BT), and the second is one bacterial nanocellulose (BNC) filled with Fe3O4. The mass fraction of BT in PVDF was 5%, and the samples were differentiated based on the duration of the mechanical activation of BT. This innovative PVDF laminate polymer with environmentally friendly fillers aligns with the concept of circular usage, resulting in a reduction in plastic content and potential improvement of the piezoelectric properties of the entire composite. This work presents new, multifunctional “green” packaging materials that potentially could be a good alternative to specific popular materials used for this purpose. The synthesis of the films was carried out using the hot press method. Tensile tests, water vapor permeability examination, and structural analyses using SEM-EDS and FTIR have been conducted. The sample PVDF/BT20/BNC/Fe3O4 exhibited the best barrier properties (impermeability to water vapor), while the highest tensile strength and toughness were exhibited by the PVDF/BT5/BNC/Fe3O4 sample

Survey of the approaches to authoritarianism and similar phenomena

The concept of authoritarianism remains vital through the time. It could be affected by the political context. Vitality of this concept has been enhanced by the demonstration of its relevance in many diverse areas. This paper present many approaches in better understanding this phenomenon. A number of different approaches of authoritarianism and similar concepts has been developed. Wilson, Ray and McCloskey connected authoritarianism with conservativism. Tomkins in his polarity theory connected affects and ideology. He claims that humanistic or left-wing personality scripts are related to liberal or low-authoritarian personal tendencies, which is connected with children raising. Gerda Lederer conducted cross-cultural investigation where she has developed New General Authoritarianism scale. Jos Meloen conducted many meta-analysis confirming validity of authoritarianism scales. Some other authors primary considered authoritarianism as a group phenomenon. Only through careful conducted investigations on many social and scientific levels, we might be in opportunity to completely understand dynamics of antidemocracy and totalitarism, and therefore be able to prevent it

Crystal rainbows

This review is devoted to ion transmission through axial channels of thin crystals. In this process the rainbows occur. The effect is called the crystal rainbow effect. We shall describe its origin and present the experiments in which it has been observed. We shall explain also how the crystal rainbows can be classified using catastrophe theory. This classification has resulted in a universal, simple and accurate approximation to the continuum potential in the channels. Besides, the periodicity of the angular distributions of transmitted ions with the reduced crystal thickness will be considered. It will be introduced via the effect of zero-degree focusing of channeled ions. In addition, we shall mention the doughnut effect in ion channeling, which has proven to be the rainbow effect with tilted crystals. All these considerations will demonstrate clearly the usefulness of the theory of crystal rainbows, which is the proper theory of ion channeling in thin crystals. (C) 2003 Elsevier Science B.V. All rights reserved.22nd Werner Brandt Workshop, Jun, 2002, Namur, Belgiu

Rainbows with Crystals and Nanotubes

This review paper is devoted to the crystal rainbow effect, which occurs in ion channeling in crystals and nanotubes. We begin with a description of crystal rainbows. Then, we analyze the evolution of the angular distribution of channeled ions with the crystal thickness. The analysis includes the rainbow cycles, and the effects of spatial focusing and angular focusing of channeled ions. This leads us to the theory of crystal rainbows. It is shown that it is the proper theory of ion channeling. After that, we describe how the effect of spatial focusing of channeled ions can be used for a subatomic microscopy. Further, the rainbow effect occurring with carbon nanotubes is considered. Finally, we demonstrate how an ion beam can be guided by a bent carbon nanotube