819 research outputs found

    A GHG Metric Methodology to Assess Onsite Buildings Non-Potable Water System for Outdoor Landscape Use

    Get PDF
    This paper documents a water:energy greenhouse gas (GHG) metric methodology for a decentralized non-potable water system that was developed as part of a Professional Doctorate in Engineering (DEng) research project by the first author. The project identified the need to investigate the challenges in changing the use of potable water to recycled water for landscape irrigation (LI) and for water features (WFs) at a medical facility case study (MFCS) in Abu Dhabi (AD) (the capital city of the United Arab Emirates (UAE). The drivers for the research project were based on the need for AD to decrease desalinated potable water as well as reduce the environmental impact and operational costs associated with the processing and use of desalinated water. Thus, the aim of the research discussed and presented in this paper was to measure the impact of using recycled and onsite non-potable water sources at the MFCS to alleviate the use of desalinated potable water and reduce associated energy consumption, operational costs, and GHG emissions (latterly in terms of carbon dioxide equivalent (CO2e), for LI and WFs. The analysis of three case scenarios at the MFCS compared different approaches to alleviate energy use, costs, and GHG impacts for the use of recycled water in LI and WFs against a baseline. The findings led to a proposed sustainable water conservation and reuse (SWC) strategy, which helped save 50% desalinated potable water for LI use by soil improvement, building water system audits, and alternate non-potable water reuse. The recommendations for this paper are to develop a SWC strategy forming the basis for a water protocol by the competent authority for regional medical facilities including an assessment methodology for building decentralized non-potable water systems to measure their energy, GHG emissions and financial impact

    Quantification et modélisation du couplage plasticité endommagement dans les polymères semicristallins à morphologie sphérolitique

    Get PDF
    Le mécanisme de fragmentation des lamelles cristallines a conduit à l’hypothèse d’un couplage entre la plasticité et l’endommagement. Après identification de la contribution visqueuse, l’endommagement et la déformation plastique sont mesurés par des essais de traction charge/décharge. Ces mesures nous ont permis d’identifier une loi de couplage unique pour les matériaux de l’étude

    Water resource management in the context of a non-potable water reuse case study in arid climate

    Get PDF
    This study evaluates an existing non-potable water system serving outdoor services for a medical facility case study (MFCS) in Abu Dhabi (AD), United Arab Emirates, using mixed methods research to identify water demand and availability of non-potable water, and to optimize water reuse for reducing waste, energy consumption and greenhouse gas emissions (GHG). The MFCS footprint includes 50% landscaping. The water used for irrigation is from non-clinical/non-potable water, treated condensate water, a by-product of air conditioning. For 5 months per year, there is a predicted non-potable water deficit, so costly and non-sustainable desalinated potable water is required for irrigation. The findings include that there is a nonpotable water deficit due to an excessive consumption for landscape irrigation (LI) and water features (WF), and that 177,288 m3 of condensate and desalinated water was wasted (equivalent to 71 Olympic swimming pools). The contribution of this research is to demonstrate that water wastage, a contributor to GHG emissions, is due to inadequate field testing and verification, water tank storage problems and a lack of LI and WF water demand management. Strategies to address these issues are suggested and will be useful to building owners, operations and maintenance teams and facility managers to substantially decrease water consumption in any type of buildings with a non-potable water system, as well as helping AD to achieve its target of a 22% reduction in GHG emissions by 2030 (Environment AgencyAbu Dhabi (EAD 2017))

    Ubiquitylation activates a peptidase that promotes cleavage and destabilization of its activating E3 ligases and diverse growth regulatory proteins to limit cell proliferation in Arabidopsis

    Get PDF
    The characteristic shapes and sizes of organs are established by cell proliferation patterns and final cell sizes, but the underlying molecular mechanisms coordinating these are poorly understood. Here we characterize a ubiquitin-activated peptidase called DA1 that limits the duration of cell proliferation during organ growth in Arabidopsis thaliana. The peptidase is activated by two RING E3 ligases, Big Brother (BB) and DA2, which are subsequently cleaved by the activated peptidase and destabilized. In the case of BB, cleavage leads to destabilization by the RING E3 ligase PROTEOLYSIS 1 (PRT1) of the N-end rule pathway. DA1 peptidase activity also cleaves the deubiquitylase UBP15, which promotes cell proliferation, and the transcription factors TEOSINTE BRANCED 1/ CYCLOIDEA/PCF 15 (TCP15) and TCP22, which promote cell proliferation and repress endoreduplication. We propose that DA1 peptidase activity regulates the duration of cell proliferation and the transition to endoreduplication and differentiation during organ formation in plants by coordinating the destabilization of regulatory proteins

    Nicotine-induced phosphorylation of ERK in mouse primary cortical neurons: evidence for involvement of glutamatergic signaling and CaMKII.

    Get PDF
    Extracellular signal-regulated kinase (ERK) is activated in vivo in a number of brain areas by nicotine and other drugs of abuse. Here we show that nicotine stimulation of cultured mouse cortical neurons leads to a robust induction of ERK phosphorylation that is dependent on nicotine concentration and duration of exposure. Calcium/calmodulin-dependent protein kinase II activity is necessary for nicotine-induced ERK phosphorylation and neither cAMP-dependent protein kinase or protein kinase C appear to be involved. Activity of glutamate receptors, L-type voltage-gated calcium channels, and voltage-gated sodium channels are also required for nicotine-induced ERK phosphorylation. Nicotine-induced ERK phosphorylation was inhibited by high concentrations of mecamylamine, however it was not blocked by other broad nicotinic acetylcholine receptor (nAChR) inhibitors (including hexamethonium and chlorisondamine) or nAChR subtype selective inhibitors (such as methyllycaconitine, alpha-bungarotoxin, dihydro-beta-erythroidine, and α-conotoxin Au1B). In accord with these pharmacological results, nicotine-induced ERK phosphorylation was normal in primary cultures made from β2 or α7 nAChR subunit knockout mice. The α3/beta4 nAChR agonist cytisine did not induce ERK phosphorylation suggesting that α3/β4 nAChRs were not involved in this process. Taken together, these data define a necessary role for glutamatergic signaling and calcium/calmodulin-dependent protein kinase II in nicotine-induced ERK phosphorylation in cortical neurons and do not provide evidence for the involvement of classical nAChRs

    Evaluation of a Landscape Irrigation Management Strategy to Support Abu Dhabi Update Its Water-Related Standards

    Get PDF
    This chapter discusses an landscape irrigation (LI) strategy to enable 100% non-potable water reuse through soil improvement, thereby reducing the environmental impacts. The case study site is a medical facility including 33,257 m2 of landscaping in Abu Dhabi (AD), the capital of the United Arab Emirates. The aim of this research is to increase net-carbon sinks, a pillar of decarbonization, as the basis for a proposed protocol to implement soil improvement techniques for the landscape architecture/agriculture industries. The interventions, based on AD soil and water recycling standards, included three different soil additives in 2016 and 2017, together with the calculation and implementation of a suitable irrigation rate to establish LI demand and reduce a five-month shortfall in air-conditioning condensate water supply. The intervention results show the case study irrigation rate was 50% less after soil improvement than the AD Municipality irrigation standard and that the LI condensate water deficit decreased by 8046 m3, a 42% reduction. The research demonstrates that carbon sinks can be increased through improved soil management; this highlights the need to update AD’s water-related standards to help the city achieve its 2030 target of a 22% reduction in greenhouse gas emissions

    The effect of annealing on the nonlinear viscoelastic response of isotactic polypropylene

    Full text link
    Three series of tensile relaxation tests are performed on isotactic polypropylene at room temperature in the vicinity of the yield point. In the first series of experiments, injection-molded samples are used without thermal pre-treatment. In the second and third series, prior to testing the specimens are annealed at 130 C for 4 and 24 hours, respectively. Constitutive equations are derived for the time-dependent response of semicrystalline polymers at isothermal loading. A polymer is treated as an equivalent temporary network of macromolecules bridged by junctions (physical cross-links, entanglements and crystalline lamellae). Under loading, junctions slip with respect to their positions in the bulk material (which reflects the viscoplastic behavior), whereas chains separate from their junctions and merge with new ones at random times (which reflects the viscoelastic response). The network is thought of as an ensemble of meso-regions (MR) with various activation energies for detachment of chains from temporary nodes. Adjustable parameters in the stress-strain relations are found by fitting observations. Experimental data demonstrate that the shape of the relaxation spectrum (characterized by the distribution of MRs with various potential energies) is independent of mechanical factors, but is altered at annealing. For specimens not subjected to thermal treatment, the growth of longitudinal strain does not affect the volume fraction of active MRs and the attempt rate for detachment of chains from their junctons. For annealed samples, the concentration of active MRs increases and the attempt rate decreases with strain. These changes in the time-dependent response are attributed to broadening of the distribution of strengths of crystalline lamellae at annealing.Comment: 30 pages, 13 figure

    A novel α-conotoxin, PeIA, cloned from Conus pergrandis, discriminates between Rat α9α10 and α7 nicotinic cholinergic receptors

    Get PDF
    The α9 and α10 nicotinic cholinergic subunits assemble to form the receptor believed to mediate synaptic transmission between efferent olivocochlear fibers and hair cells of the cochlea, one of the few examples of postsynaptic function for a non-muscle nicotinic acetylcholine receptor (nAChR). However, it has been suggested that the expression profile of α9 and α10 overlaps with that of α7 in the cochlea and in sites such as dorsal root ganglion neurons, peripheral blood lymphocytes, developing thymocytes, and skin. We now report the cloning, total synthesis, and characterization of a novel toxin α-conotoxin PeIA that discriminates between α9α10 and α7 nAChRs. This is the first toxin to be identified from Conus pergrandis, a species found in deep waters of the Western Pacific. α-Conotoxin PeIA displayed a 260-fold higher selectivity for α-bungarotoxin-sensitive α9α10 nAChRs compared with α-bungarotoxin-sensitive α7 receptors. The IC50 of the toxin was 6.9 ± 0.5 nM and 4.4 ± 0.5 nM for recombinant α9α10 and wild-type hair cell nAChRs, respectively. α-Conotoxin PeIA bears high resemblance to α-conotoxins MII and GIC isolated from Conus magus and Conus geographus, respectively. However, neither α-conotoxin MII nor α-conotoxin GIC at concentrations of 10 μM blocked acetylcholine responses elicited in Xenopus oocytes injected with the α9 and α10 subunits. Among neuronal non-α-bungarotoxin- sensitive receptors, α-conotoxin PeIA was also active at α3β2 receptors and chimeric α6/α3β2β3 receptors. α-Conotoxin PeIA represents a novel probe to differentiate responses mediated either through α9α10 or α7 nAChRs in those tissues where both receptors are expressed.Fil: McIntosh, J. Michael. University of Utah; Estados UnidosFil: Plazas, Paola Viviana. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Watkins, Maren. University of Utah; Estados UnidosFil: Gomez Casati, Maria Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Olivera, Baldomero M.. University of Utah; Estados UnidosFil: Elgoyhen, Ana Belen. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentin

    The effect of annealing on the elastoplastic and viscoelastic responses of isotactic polypropylene

    Full text link
    Observations are reported on isotactic polypropylene (i) in a series of tensile tests with a constant strain rate on specimens annealed for 24 h at various temperatures in the range from 110 to 150 C and (ii) in two series of creep tests in the sub-yield region of deformation on samples not subjected to thermal treatment and on specimens annealed at 140 C. A model is developed for the elastoplastic and nonlinear viscoelastic responses of semicrystalline polymers. A polymer is treated an equivalent transient network of macromolecules bridged by junctions (physical cross-links, entanglements and lamellar blocks). The network is assumed to be highly heterogeneous, and it is thought of as an ensemble of meso-regions with different activation energies for separation of strands from temporary nodes. The elastoplastic behavior is modelled as sliding of meso-domains with respect to each other driven by mechanical factors. The viscoelastic response is attributed to detachment of active strands from temporary junctions and attachment of dangling chains to the network. Constitutive equations for isothermal uniaxial deformation are derived by using the laws of thermodynamics. Adjustable parameters in the stress-strain relations are found by fitting the experimental data.Comment: 29 pages, 14 figure
    • …
    corecore