Compressible Media for Water Treatment

Tertiary water treatment is used to remove total suspended solids (TSS) from wastewater. Suez uses compressible media for their tertiary water treatment. There have been supplier issues in the past such as unreliability, long lead-times, unknown manufacturing process, and chances of resale. The chance of resale is an important issue because the specifications may change from one supplier to another. The group was tasked to characterize different types of compressible media for water treatment, design a lab scale filtration unit, and design and manufacture a new media to be tested. In order to gain an operational expenditure advantage, Suez accomplishes media compression without the use of a mechanical device, which was taken into account when designing the filtration unit. The media characterization determined that the media’s fiber was crimped polyethylene terephthalate and the node was atactic polystyrene. The original media was tested on the lab scale filtration unit at concentrations of 10, 30, and 50 mg TSS/L. Due to the size of PVC column diameter (3 inches), channeling and wall-effects were observed, which allowed solids to pass through the media. Because of these effects, the 10 mg TSS/L run was the only acceptable test in terms of turbidity requirements (\u3c2 NTU). New media was designed and manufactured using uncrimped polyethylene terephthalate and hot melt adhesive. The team has future plans to test the new media on the filtration unit. It is expected that the media will be less successful because the fibers are uncrimped.https://scholarscompass.vcu.edu/capstone/1156/thumbnail.jp

In-plane magnetoelectric response in bilayer graphene

A graphene bilayer shows an unusual magnetoelectric response whose magnitude is controlled by the valley-isospin density, making it possible to link magnetoelectric behavior to valleytronics. Complementary to previous studies, we consider the effect of static homogeneous electric and magnetic fields that are oriented parallel to the bilayer's plane. Starting from a tight-binding description and using quasi-degenerate perturbation theory, the low-energy Hamiltonian is derived including all relevant magnetoelectric terms whose prefactors are expressed in terms of tight-binding parameters. We confirm the existence of an expected axion-type pseudoscalar term, which turns out to have the same sign and about twice the magnitude of the previously obtained out-of-plane counterpart. Additionally, small anisotropic corrections to the magnetoelectric tensor are found that are fundamentally related to the skew interlayer hopping parameter $\gamma_4$. We discuss possible ways to identify magnetoelectric effects by distinctive features in the optical conductivity.Comment: 14 pages, 7 figure

Weak (anti)localization in tubular semiconductor nanowires with spin-orbit coupling

We compute analytically the weak (anti)localization correction to the Drude conductivity for electrons in tubular semiconductor systems of zinc blende type. We include linear Rashba and Dresselhaus spin-orbit coupling (SOC) and compare wires of standard growth directions $\langle100\rangle$, $\langle111\rangle$, and $\langle110\rangle$. The motion on the quasi-two-dimensional surface is considered diffusive in both directions: transversal as well as along the cylinder axis. It is shown that Dresselhaus and Rashba SOC similarly affect the spin relaxation rates. For the $\langle110\rangle$ growth direction, the long-lived spin states are of helical nature. We detect a crossover from weak localization to weak anti-localization depending on spin-orbit coupling strength as well as dephasing and scattering rate. The theory is fitted to experimental data of an undoped $\langle111\rangle$ InAs nanowire device which exhibits a top-gate-controlled crossover from positive to negative magnetoconductivity. Thereby, we extract transport parameters where we quantify the distinct types of SOC individually.Comment: 17 pages, 9 figure

Cетевой мониторинг программного обеспечения в информационной инфраструктуре предприятия

The article is devoted to network monitoring software enterprises. The process of providing functional and technical state of the system are described the actual business needs of the company. The paper proposes a solution to the optimization of this process, based on the scope of activities of the enterprise

Identification of the Drosophila melanogaster homolog of the human spastin gene

The human SPG4 locus encodes the spastin gene, which is responsible for the most prevalent form of autosomal dominant hereditary spastic paraplegia (AD-HSP), a neurodegenerative disorder. Here we identify the predicted gene product CG5977 as the Drosophila homolog of the human spastin gene, with much higher sequence similarities than any other related AAA domain protein in the fly. Furthermore we report a new potential transmembrane domain in the N-terminus of the two homologous proteins. During embryogenesis, the expression pattern of Drosophila spastin becomes restricted primarily to the central nervous system, in contrast to the ubiquitous expression of the vertebrate spastin genes. Given this nervous system-specific expression, it will be important to determine if Drosophila spastin loss-of-function mutations also lead to neurodegeneratio

Structural, chemical and magnetic properties of secondary phases in Co-doped ZnO

We have utilized a comprehensive set of experimental techniques such as transmission electron microscopy (TEM) and synchrotron-based x-ray absorption spectroscopy (XAS) and the respective x-ray linear dichroism and x-ray magnetic circular dichroism to characterize the correlation of structural, chemical and magnetic properties of Co-doped ZnO samples. It can be established on a quantitative basis that the superparamagnetic (SPM) behavior observed by integral superconducting quantum interference device magnetometry is not an intrinsic property of the material but stems from precipitations of metallic Co. Their presence is revealed by TEM as well as XAS. Annealing procedures for these SPM samples were also studied, and the observed changes in the magnetic properties found to be due to a chemical reduction or oxidation of the metallic Co species

The role of maternal emotional availability and attachment in child emotion regulation

Emotions are an essential aspect of human life. They help us to evaluate the importance of an event, to act quickly in a variety of situations, and to communicate with others in social interactions. However, the intensity or duration of emotional responses may not always be adaptive in a given situation or social context. Thus, the ability to regulate emotions is crucial for ones’ well-being, mental health, and socio-emotional functioning. A vast body of literature has emphasized the role of the social environment in children’s development of emotion regulation. Theoretical accounts have emphasized the significance of experiences within caregiving relationships that contribute considerably to the development of (mal-) adaptive emotion regulation (Cassidy, 1994; Kopp, 1989; Sroufe, 1996a). The current thesis focused on attachment security (Ainsworth et al., 1974; Bowlby, 1969/82; Cassidy, 1994) and maternal emotional availability (Biringen, 2008; Biringen et al., 2014) as two key aspects of caregiver–child relationship quality that support children’s development of adaptive emotion regulation. Despite a large body of research on child emotion regulation, not all stages of emotion regulation have been addressed equally in young children. The stage of attentional regulation is particularly interesting as attentional distraction is one of the earliest regulation strategies that emerge. Yet, only few studies have investigated young children’s attentional regulation in response to facial expressions. Furthermore, the stage of behavioral regulation is particularly important in difficult social interactions with others. However, young children’s behavioral regulation in frustrating situations has so far not been researched in cooperative interactions with others. Considering the importance of the domain of emotional development for later developmental outcomes, the current thesis focused on the role of attachment and maternal emotional availability for young children’s attentional and behavioral regulation. For that purpose, three studies were conducted, focusing on two age groups, that is, preschool and toddler period. The first study investigated the relation of attachment security and attentional regulation in preschoolers. In particular, the study examined the relation between preschoolers’ attachment security and their visual attention to facial emotional expressions. To this end, 5-year-olds’ generalized attachment representations and their attention duration to pictures of negative and positive facial expressions were assessed. Results revealed that secure attachment was related to prolonged attention to fearful, sad, and neutral facial expressions. The study supports the notion that attachment security plays a significant role in young children’s attention to emotional information. The second study investigated the relation of maternal emotional availability and attentional regulation in toddlers. In particular, the study examined the reciprocal relations of maternal sensitivity and non-intrusiveness and children’s visual attention to emotional facial expressions. To this end, mothers’ behavior was observed in play interactions and children’s attention to negative and positive facial expressions were assessed at 12 and 24 months. Cross-lagged panel analyses revealed that more sensitive behavior at 12 months predicted prolonged attention to sad and happy expressions at 24 months, while less intrusive caregiving at 12 months predicted prolonged attention to sad expressions at 24 months. Concurrent maternal emotional availability had no effect on toddlers’ attentional regulation. The study supports the notion that maternal sensitive behavior plays a significant role in young children’s attention to emotional information. The third study investigated the relation of maternal emotional availability and behavioral regulation in toddlers. In particular, the study examined whether maternal sensitivity and non-intrusiveness contribute to children’s behavior in difficult cooperative interactions beyond child cognitive skills and temperament. To this end, mothers’ sensitivity and non-intrusiveness were observed in play interactions and children’s behavior to interruptions in two difficult cooperative interactions was assessed at 24 months. Results revealed that maternal intrusiveness was related to child disengagement from the task and approach to the mother. Yet, active help seeking was predicted only by toddler cognitive skills, while reengagement of the experimenter was predicted neither by maternal nor by child characteristics. The study supports the notion that maternal behavior plays a significant role in young children’s use of specific behavioral strategies in frustrating situations. Overall, the current thesis supports specific relations of caregiver–child relationship aspects and young children’s attentional and behavioral regulation. In the preschool period and the toddler period, attachment security (Study 1) and maternal emotional availability (Study 2) are related to children’s attention to emotional facial expressions. Yet, effects are more pronounced in relation to negative emotions and for influences of attachment security and sensitivity. Furthermore, in the toddler period, dimensions of maternal emotional availability contribute differently to the development of attentional and behavioral regulation strategies. While sensitive caregiving is an important factor in toddlers’ attention to positive and negative emotions, intrusive caregiving plays a crucial role for toddlers’ attentional avoidance of negative emotions and for their behavioral disengagement form difficult interactions. In conclusion, the current thesis contributes to a better understanding of the role of caregiver–child relationship quality in young children’s emotion regulation and provides implications for research on child socioemotional development

Ferromagnetism and colossal magnetic moment in Gd-focused ion-beam-implanted GaN

The structural and the magnetic properties of Gd-focused ion-beam-implanted GaN layers are studied. Gd^(3+) ions were uniformly implanted in molecular beam epitaxy rown GaN layers at room temperature with an energy of 300 keV at doses ranging from 2.4x10^(11) to 1.0x10^(15) cm^(-2) which corresponds to an average Gd concentration range of 2.4x10^(16)-1.0x10^(20) cm^(-3). The implanted samples were not subjected to any annealing treatment. No secondary phase related to Gd was detected by x-ray diffraction in these layers. Magnetic characterization with superconducting quantum interference device reveals a colossal magnetic moment of Gd and ferromagnetism with an order temperature above room temperature similar to that found in epitaxially grown Gd-doped GaN layers. The effective magnetic moment per Gd atom in these samples is, however, found to be an order of magnitude larger than that found in epitaxially grown layers for a given Gd concentration which indicates that the defects play an important role in giving rise to this effect

Surface clustering of metabotropic glutamate receptor 1 induced by long Homer proteins

BACKGROUND: Metabotropic glutamate receptors (mGluRs) regulate neuronal excitability and synaptic strength. The group I mGluRs, mGluR1 and 5, are widespread in the brain and localize to post-synaptic sites. The Homer protein family regulates group I mGluR function and distribution. Constitutively expressed 'long' Homer proteins (Homer 1b, 1c, 2 and 3) induce dendritic localization of group I mGluRs and receptor clustering, either internally or on the plasma membrane. Short Homer proteins (Homer 1a, Ania-3) exhibit regulated expression and act as dominant negatives, producing effects on mGluR distribution and function that oppose those of the long Homer proteins. There remains some controversy over whether long Homer proteins induce receptor internalization by inducing retention in the endoplasmic reticulum, or induce mGluR clustering on the plasma membrane. Further, an exhaustive study of the effects of each long Homer isoform on mGluR distribution has not been published. RESULTS: The distribution of a GFP-tagged group I mGluR, mGluR1-GFP, was examined in the absence of Homer proteins and in the presence of several Homer isoforms expressed in sympathetic neurons from the rat superior cervical ganglion (SCG) using total internal reflection fluorescence (TIRF-M) and confocal microscopy. Quantitative analysis of mGluR1-GFP fluorescence using TIRF-M revealed that expression of each long Homer isoform tested (Homer 1b, 1c, 2b and 3) induced a significant degree of surface clustering. Using confocal imaging, Homer-induced mGluR clusters were observed intra-cellularly as well as on the plasma membrane. Further, in approximately 40% of neurons co-expressing mGluR1-GFP and Homer 1b, intracellular inclusions were observed, but plasma membrane clusters were also documented in some Homer 1b coexpressing cells. CONCLUSION: All long Homer proteins examined (Homer 1b, 1c, 2b and 3) induced a significant degree of mGluR1-GFP clustering on the plasma membrane compared to cells expressing mGluR1-GFP alone. Clusters induced by long Homers appeared on the plasma membrane and intracellularly, suggesting that clusters form prior to plasma membrane insertion and/or persist after internalization. Finally, while Homer 1b induced surface clustering of mGluR1 in some cells, under some conditions intracellular retention may occur