The Use of Magnetic Nanomaterials for the Retaining of Cu(II) Ions out of Residual Water

In the developed countries the removal of hard materials from residual waters using advanced technologies such as ionic change, precipitation, ultrafiltration or electrochemical deposits seems inconvenient from the economic point of view for the industry because its high costs. Therefore, it is necessary to introduce new technologies that imply low costs. By linking chitosan and magnetite particles (Fe3O4), a new magnetic adsorbent with 100-200 nm particles and of great efficiency to move off the metalic ions is obtained. That is why this study aims to obtain a new magnetic material with great efficiency to retain copper out of synthetic solutions, and then to compare it, from the retaining point of view, with simple synthesized magnetide (Fe3O4)

Advances in understanding and treating ADHD

Attention deficit hyperactivity disorder (ADHD) is a neurocognitive behavioral developmental disorder most commonly seen in childhood and adolescence, which often extends to the adult years. Relative to a decade ago, there has been extensive research into understanding the factors underlying ADHD, leading to far more treatment options available for both adolescents and adults with this disorder. Novel stimulant formulations have made it possible to tailor treatment to the duration of efficacy required by patients, and to help mitigate the potential for abuse, misuse and diversion. Several new non-stimulant options have also emerged in the past few years. Among these, cognitive behavioral interventions have proven popular in the treatment of adult ADHD, especially within the adult population who cannot or will not use medications, along with the many medication-treated patients who continue to show residual disability

The ATHENA X-ray Integral Field Unit (X-IFU)

The X-ray Integral Field Unit (X-IFU) is the high resolution X-ray spectrometer of the ESA Athena X-ray observatory. Over a field of view of 5' equivalent diameter, it will deliver X-ray spectra from 0.2 to 12 keV with a spectral resolution of 2.5 eV up to 7 keV on ∼ 5" pixels. The X-IFU is based on a large format array of super-conducting molybdenum-gold Transition Edge Sensors cooled at ∼ 90 mK, each coupled with an absorber made of gold and bismuth with a pitch of 249 μm. A cryogenic anti-coincidence detector located underneath the prime TES array enables the non X-ray background to be reduced. A bath temperature of ∼ 50 mK is obtained by a series of mechanical coolers combining 15K Pulse Tubes, 4K and 2K Joule-Thomson coolers which pre-cool a sub Kelvin cooler made of a 3He sorption cooler coupled with an Adiabatic Demagnetization Refrigerator. Frequency domain multiplexing enables to read out 40 pixels in one single channel. A photon interacting with an absorber leads to a current pulse, amplified by the readout electronics and whose shape is reconstructed on board to recover its energy with high accuracy. The defocusing capability offered by the Athena movable mirror assembly enables the X-IFU to observe the brightest X-ray sources of the sky (up to Crab-like intensities) by spreading the telescope point spread function over hundreds of pixels. Thus the X-IFU delivers low pile-up, high throughput (< 50%), and typically 10 eV spectral resolution at 1 Crab intensities, i.e. A factor of 10 or more better than Silicon based X-ray detectors. In this paper, the current X-IFU baseline is presented, together with an assessment of its anticipated performance in terms of spectral resolution, background, and count rate capability. The X-IFU baseline configuration will be subject to a preliminary requirement review that is scheduled at the end of 2018

Dendrimers - Fundamentals and Applications

Dendrimers are defined as nanoscale macromolecules having a particular architecture consisting of treelike arms or branches. They are characterized by special properties that make them promising candidates in medicine, biology, materials science, synthetic organic chemistry, biotechnology, environmental engineering, optics, electronics, catalysis, electrochemistry, photochemistry, and sensors and even for production of cosmetics and personal care products. The dendrimers research field is growing day by day, and scientists are exploring new synthesis and functionalization methods in order to improve and to determine new properties and thus new applications. The main purpose of this book is to highlight the issues regarding properties and applications of dendrimers in the field of biology, medicine, liquid crystal devices, electronics, quantum devices, and self-healing technology

Nanocrystals and Nanostructures

Nanocrystals and nanostructures attract a special attention in the recent years due to their various properties and a wide range of applications such as in electrical, optical, optoelectronic, catalytic, medicine, chemo- and biosensing, and environmental protection fields. Although extensive research has been done in the field of nanocrystals, it is considered one growing research field. The main goal of this book is to present the current research activities in the field of nanocrystals and nanostructures covering issues regarding new synthesis methods, self-assembly strategies, characterization techniques, properties, and applications. Interesting reports regarding biomimetic modeling of the biomineralization processes and theoretical models to describe mechanisms of deformation twinning in nanocrystalline and ultrafine-grained materials have been presented. By structuring, approaching, and content, the work may be useful for specialist in the field of nano-/materials science, PhD students, students, and all those interested in this topic of high relevance

Novel Magnetic Nanocomposites Based on Carboxyl-Functionalized SBA-15 Silica for Effective Dye Adsorption from Aqueous Solutions

In this study, three novel magnetic nanocomposites based on carboxyl-functionalized SBA-15 silica and magnetite nanoparticles were prepared through an effective and simple procedure and applied for methylene blue (MB) and malachite green G (MG) adsorption from single and binary solutions. Structure, composition, morphology, magnetic, and textural properties of the composites were thoroughly investigated. The influence of the amount of carboxyl functional groups on the physicochemical and adsorptive properties of the final materials was investigated. The capacity of the synthesized composites to adsorb MB and MG from single and binary solutions and the factors affecting the adsorption process, such as contact time, solution pH, and dye concentration, were assessed. Kinetic modelling showed that the dye adsorption mechanism followed the pseudo-second-order kinetic model, indicating that adsorption was a chemically controlled multilayer process. The adsorption rate was simultaneously controlled by external film diffusion and intraparticle diffusion. It was evidenced that the molecular geometry of the dye molecule plays a major role in the adsorption process, with the planar geometry of the MB molecule favoring adsorption. The analysis of equilibrium data revealed the best description of MB adsorption behavior by the Langmuir isotherm model, whereas the Freundlich model described better the MG adsorption

Din istoria presei româneşti : Republica Română : Paris, 1851 - Bruxelles, 1853

Bucureşti : Cartea Românească, 193