Cold reaction valleys in the radioactive decay of superheavy {286}^112, {292}^114 and {296}^116 nuclei

Cold reaction valleys in the radioactive decay of superheavy nuclei {286}^112, {292}^114 and {296}^116 are studied taking Coulomb and Proximity Potential as the interacting barrier. It is found that in addition to alpha particle, 8^Be, 14^C, 28^Mg, 34^Si, 50^Ca, etc. are optimal cases of cluster radioactivity since they lie in the cold valleys. Two other regions of deep minima centered on 208^Pb and 132^Sn are also found. Within our Coulomb and Proximity Potential Model half-life times and other characteristics such as barrier penetrability, decay constant for clusters ranging from alpha particle to 68^Ni are calculated. The computed alpha half-lives match with the values calculated using Viola--Seaborg--Sobiczewski systematics. The clusters 8^Be and 14^C are found to be most probable for emission with T_1/2 < 1030s. The alpha-decay chains of the three superheavy nuclei are also studied. The computed alpha decay half-lives are compared with the values predicted by Generalized Liquid Drop Model and they are found to match reasonably well.Comment: 21 pages, 6 figure

Polyhydroxyl fullerene can mitigate toxicity effects of cadmium on yeasts

With inception of nanotechnology, nanomaterials are currently in the prime-line of research. Polyhydroxyl fullerene is one of the widely commercialized nanomaterials and applied in electronics and biomedical fields. Unlike fullerene, polyhydroxyl fullerene is known to be biocompatible, and recent studies reported its antioxidant properties. On the other hand, cadmium toxicity has been often attributed to the ability of this metal to induce oxidative stress. To assess antioxidant properties of polyhydroxyl fullerene, the model yeast Saccharomyces cerevisiae was exposed to cadmium (≤ 5 ppm, 3 levels) in the presence or absence of polyhydroxyl fullerene (≤ 500 ppm, 3 levels) at different pH values (5.8, 6.3 and 6.8). The size distribution and dispersion of polyhydroxyl fullerene in the stock suspension were measured with DLS (z-average 143 nm, PdI 0.365). Yeast growth, plasma membrane integrity and accumulation of reactive oxygen species (ROS) were investigated in the presence or absence of Cd2+ and/or polyhydroxyl fullerene. Yeast growth was inhibited up to 34% by exposure to Cd2+, but was not affected by polyhydroxyl fullerene. At pH 5.8, the exposure to the highest concentration of Cd2+ (5 ppm) and polyhydroxyl fullerene (500 ppm) stimulated yeast growth by 59 and 61% at the exponential and late exponential growth phases, respectively. Growth increased even more when pH increased to 6.8. Severe plasma membrane disruption and ROS accumulation were observed after exposure to the highest concentration of Cd2+ in the absence of polyhydroxyl fullerene. Membrane disruption and ROS accumulation decreased with increasing concentration of polyhydroxyl fullerene and with the increase in pH to 6.8. Overall, results indicated that polyhydroxyl fullerene is not toxic to yeasts and may potentially trigger antioxidant defense mechanisms to mitigate metal-induced toxicity.Funding: FEDER-POFC-COMPETE and FCT supported this study (PEst-C/BIA/UI4050/2011, NANOECOTOX- PTDC/AAC-AMB/121650/2010) and A. Pradhan (SFRH/BD/45614/2008)

Impacts of CuO nanoparticles on aquatic detritus foodwebs

FEDER-POFC-COMPETE and the Portuguese Foundation for Science and Technology supported this study (PEst-C/BIA/UI4050/2011, NANOECOTOX-PTDC/AAC-AMB/121650/2010) and A. Pradhan was supported by FCT (SFRH/BD/45614/2008)

Nano copper oxide is a threat to an endemic shredder of the Iberian Peninsula

FEDER-POFC-COMPETE and the Portuguese Foundation for Science and Technology supported this study (PEst-C/BIA/UI4050/2011, NANOECOTOX-PTDC/AAC-AMB/121650/2010) and A. Pradhan was supported by the Portuguese Foundation for Science and Technology (SFRH/BD/45614/2008)

MATLAB based real time control implementation of DC servo motor using PCI card

The DC servo motor has applications in automotive market in applications ranging from heating and ventilation to power mirror positioning. It is also in use in Industrial and Consumer Markets for entertainment equipment, HVAC ventilation control and myriad number of other applications. In all these applications, either speed or position control of the DC servo motor is used. In this project, we have achieved MATLAB based real-time speed control implementation of DC servo motor using PCI-1716. For a more efficient speed control, closed loop control system of the servo motor is realized with the help of a tuned PID controller. Further, progress has also been made in remote control of DC servo motor. For this, a communication has been established between the local and the remote PC; and PID controlled closed loop system, with the controller at the remote PC was successfully achieved and checked for optimal performance. However, due to delays introduced in the communication system, the remote control using PID was not found to be as efficient as the local control and the speed output was found to lag behind the reference signal. To compensate for this delay, a Smith Predictor incorporated model has been made

Zeros of tree amplitudes at rest and symmetries of mechanical systems

We consider the tree amplitudes of production of $n_2$ scalar particles by $n_1$ particles of another kind, where both initial and final particles are at rest and on mass shell, in a model of two scalar fields with $O(2)$ symmetric interaction and unequal masses. We find that these amplitudes are zero except for the lowest possible $n_1$ and $n_2$, and that the cancellation of the corresponding Feynman graphs occurs due to a special symmetry of the classical mechanical counterpart of this theory. This feature is rather general and is inherent in various other scalar field theories.Comment: 11 pages Preprint INR-830/93, August 199

An ubiquitous perspective of the intraspecific diversity of the aquatic fungus articulospora tetracladia

The cosmopolitan Articulospora tetracladia is a dominant sporulating species on decomposing plant-litter in streams of Northwest Iberian Peninsula. In an attempt to elucidate the intraspecific genetic diversity of A. tetracladia of Iberian Peninsula, isolates were attained from various types of substrates from streams of North and Central Portugal and North Spain, between 2000 and 2010. Genetic diversity of these fungal populations was assessed by denaturing gradient gel electrophoresis (DGGE) fingerprints and by using ITS1-5.8S-ITS2 barcodes. The ITS1-5.8S-ITS2 barcodes published at the National Center for Biotechnology (NCBI) or National Institute of Technology and Evaluation Biological Resource Center (NBRC) were retrieved to probe into the genetic diversity of A. tetracladia isolated from Iberian Peninsula and other parts of the world (Central Europe, UK, Canada, Japan and Malaysia). The PCR-DGGE of ITS2 region of 50 Iberian fungal isolates distinguished 8 OTUs. The ITS sequences of 68 fungal isolates yielded nine OTUs, but 5 fungal isolates were not assigned to any of these OTUs. The A. tetracladia strains did not exhibit cohesiveness based on sampling date or substrate or geographic location. Overall results indicate that, apart Malaysian genotypes, A. tetracladia genotypes are geographically widespread irrespective of sampling time, sites or substrates. Moreover, PCR-DGGE appeared to be a rapid tool for assessing intraspecific diversity of aquatic hyphomycetes.FEDER-POFC-COMPETE and FCT supported this study (PEst-C/BIA/UI4050/2011 and PTDC/AAC-AMB/113746/2009) and SD (SFRH/BPD/47574/2008)

Does the riparian stand and age affect ecosystem functioning in streams?

In riparian restoration projects tree species are often planted in assemblages that diverge from patterns seen in natural communities. This restoration practice may have consequences on the aquatic ecosystem processes as streams obtain energy from leaf litter inputs in the riparian zones. Leaf litter decomposition in streams is a vital ecosystem-level process, which depends on the activity of microorganisms and invertebrates. In the current study we attempted to assess whether leaf age and type of different widespread tree species in the Northwest Portugal, namely oak (Quercus robur L.), alder (Alnus glutinosa (L.) Gaertn.) and eucalyptus (Eucalyptus globulus Labill.) affect ecosystem functioning in streams. Leaf mass loss and fungal biomass and invertebrate biomass and diversity were examined in five mixtures with varied percentage of juvenile and mature leaves of oak, alder and eucalyptus. Our results indicate that leaf age and type had a significant effect on leaf mass loss, fungal biomass, and invertebrate biomass, abundance and diversity. Age class showed a significant effect on the decomposition of alder leaves and the associated fungi and invertebrates, but effects were not evident for other leaf types. This study gives an insight into how changing the diversity and community of riparian forest stand through restoration practices influence the ecosystem process, and may have consequences for future management strategies.The European Regional Development Fund - Operational Competitiveness Program (FEDER-POFC-COMPETE

Recent Advances on Anilato-Based Molecular Materials with Magnetic and/or Conducting Properties

The aim of the present work is to highlight the unique role of anilato-ligands, derivatives of the 2,5-dioxy-1,4-benzoquinone framework containing various substituents at the 3 and 6 positions (X = H, Cl, Br, I, CN, etc.), in engineering a great variety of new materials showing peculiar magnetic and/or conducting properties. Homoleptic anilato-based molecular building blocks and related materials will be discussed. Selected examples of such materials, spanning from graphene-related layered magnetic materials to intercalated supramolecular arrays, ferromagnetic 3D monometallic lanthanoid assemblies, multifunctional materials with coexistence of magnetic/conducting properties and/or chirality and multifunctional metal-organic frameworks (MOFs) will be discussed herein. The influence of (i) the electronic nature of the X substituents and (ii) intermolecular interactions i.e., H-Bonding, Halogen-Bonding, π-π stacking and dipolar interactions, on the physical properties of the resulting material will be also highlighted. A combined structural/physical properties analysis will be reported to provide an effective tool for designing novel anilate-based supramolecular architectures showing improved and/or novel physical properties. The role of the molecular approach in this context is pointed out as well, since it enables the chemical design of the molecular building blocks being suitable for self-assembly to form supramolecular structures with the desired interactions and physical propertie