289 research outputs found
Paper Session I-B - Industrial Reflight of Eureca Platform in 1998
The reusable space platform Eureca was developed under the authority of the European Space Agency Esa and had its 11 months maiden flight in 1992/93. Launched and retrieved by the Shuttle the 4.5 ton-platform is capable of free-flying in a low earth orbit for a period of some 6-9 months and provides a stable high quality microgravity environment, good attitude accuracy and large payload resources. Together with the remote science operation capabilities, these features allow a wide range of scientific applications, i.e. astronomy, solar and atmospheric physics, earth observation, space technology, physical and life sciences under microgravity conditions. Based on Esa’s intention to foster the industrialization of space programmed, Esa intends to transfer the Eureca spacecraft and Esa’s core payloads to Daimler-Benz Aerospace AG (Dasa), which has been the prime contractor for this platform. By this transfer (entered into force since January 1st 1996), Dasa has the responsibility and risk for overall mission implementation and the freedom to assemble a payload in accordance with user demands. It is planned that this will be performed by an international team of aerospace companies headed by Dasa
Investigating the Causes of Delay in Construction of Urban Water Supply and Wastewater Project in Water and WasteWater Project in Tehran
It is obvious that providing drinking water in cities, especially in metropolises such as Tehran, as a political-social-economic center of the country is important. During the last decades, climatic changes, the decrease of raining, the increase of water harvesting from groundwater as well as the increase of population have intensified the importance of water in Tehran. Therefore, every change from water consumption to collecting, purifying and storing drinking water in the city reservoirs is highly critical. In the present study, the causes of delay in such projects have been determined based on experts' opinions about several concrete implemented reservoirs obtained by questionnaire and the related literature. Given to three classes pertained to such projects (employer, consultant and contractor), an initial questionnaire was provided to poll the experts' opinions and distributed among the sample of the study. In this regard, 45 Likert-scale questionnaires were equally distributed among three population; after gathering, the items with higher mean scores were selected for the main questionnaire (totally, 17 items). Using AHP method, the most important factors were identified and ranked through Expert choice Software. As the research findings revealed, failure of employer to pay to contractor timely, failure to obtaining the necessary permissions by employer before noticing to contactor to proceed, and uncertainty and buying project site by employer are the most important factors respectively
Proteomic Approaches to Dissect Host SUMOylation during Innate Antiviral Immune Responses
SUMOylation is a highly dynamic ubiquitin-like post-translational modification that is essential for cells to respond to and resolve various genotoxic and proteotoxic stresses. Virus infections also constitute a considerable stress scenario for cells, and recent research has started to uncover the diverse roles of SUMOylation in regulating virus replication, not least by impacting antiviral defenses. Here, we review some of the key findings of this virus-host interplay, and discuss the increasingly important contribution that large-scale, unbiased, proteomic methodologies are making to discoveries in this field. We highlight the latest proteomic technologies that have been specifically developed to understand SUMOylation dynamics in response to cellular stresses, and comment on how these techniques might be best applied to dissect the biology of SUMOylation during innate immunity. Furthermore, we showcase a selection of studies that have already used SUMO proteomics to reveal novel aspects of host innate defense against viruses, such as functional cross-talk between SUMO proteins and other ubiquitin-like modifiers, viral antagonism of SUMO-modified antiviral restriction factors, and an infection-triggered SUMO-switch that releases endogenous retroelement RNAs to stimulate antiviral interferon responses. Future research in this area has the potential to provide new and diverse mechanistic insights into host immune defenses
Comparison of seismic performance of steel frames equipped with diagonal and chevron viscous damper under near and far field earthquakes
A complete comparison of seismic behavior of the application of Diagonal and Chevron Viscous Damper in steel structures is presented in this paper. OpenSees software is used for the numerical modeling of structures. Fifteen numbers of earthquake records are applied to the structures and full nonlinear time history analysis is done. Force-displacement of chevron braces with and without a damper are compared and the results of IDA curves are also presented for different percentiles
Synthesis, Structure and Bonding Analysis of the Zwitterionic PPP-Pincer Complex (6-Ph2P-Ace-5-)2P(O)AuCl2
The reaction of (6-Ph2P-Ace-5-)2P(O)H with (tht)AuCl3proceeds via elimination oftetrahydrothiophene (tht) and HCl, providing the zwitterionic PPP-pincer complex (6-Ph2P-Ace-5-)2P(O)AuCl2(1) as yellow crystals. The molecular structure of1was established and studied by X-raycrystallography. The electronic structure was computationally analyzed using a comprehensiveset of real-space bonding indicators derived from electron and electron-pair densities, providinginsight into the relative contributions of covalent and non-covalent forces to the polar-covalent Au–Cl,Au–P, and P–O−bonds; the latter being one of the textbook cases for strongly polarized covalentinteractions. Partial spatial complementarity between both bonding aspects is suggested by theelectronic properties of the distinctively different Au–Cl bonds
Minimizing Electricity Cost through Smart Lighting Control for Indoor Plant Factories
Smart plant factories incorporate sensing technology, actuators and control
algorithms to automate processes, reducing the cost of production while
improving crop yield many times over that of traditional farms. This paper
investigates the growth of lettuce (Lactuca Sativa) in a smart farming setup
when exposed to red and blue light-emitting diode (LED) horticulture lighting.
An image segmentation method based on K-means clustering is used to identify
the size of the plant at each stage of growth, and the growth of the plant
modelled in a feed forward network. Finally, an optimization algorithm based on
the plant growth model is proposed to find the optimal lighting schedule for
growing lettuce with respect to dynamic electricity pricing. Genetic algorithm
was utilized to find solutions to the optimization problem. When compared to a
baseline in a simulation setting, the schedules proposed by the genetic
algorithm can achieved between 40-52% savings in energy costs, and up to a 6%
increase in leaf area.Comment: IEEE IECON 202
Kinetic Stabilization of Heavier Bis(m-terphenyl)pnictogen Phosphaethynolates
Kinetic stabilization using bulky m-terphenyl substituents is the key to the isolation of the diarylantimony and diarylbismuth phosphaethynolates (2,6-Mes2C6H3)2EPCO and the related N-heterocyclic carbene complexes (2,6-Mes2C6H3)2EP(O)C(IMe4) (E=Sb, Bi; IMe4=1,3,4,5-tetramethylimidazol-2-ylidene), which have been fully characterized crystallographically and spectroscopically. The experimental characterization was augmented by a DFT based real space bond indicator analysis of the electron density, including AIM, NCI, and ELI-D methods
Silyl Cations Stabilized by Pincer Type Ligands with Adjustable Donor Atoms
Novel E,C,E'-pincer supported silyl cations (E, E' = O, S, Se, Au) were prepared in three steps starting from 2,6-F2C6H3SiMe2H (1a) and 2,6-Br2C6H3SiMe2H (1b), which were first converted in two complementary ways into 2,6-(Ph2P)(2)C6H3SiMe2H (2). The oxidation of 2 with H2O2 center dot urea, S-8, and Se-8 afforded 2,6-(Ph2PE)(2)C6H3SiMe2H (3a, E = O; 3b, E = S; 3c, E = Se) and 2-(Ph2PE)-6-(Ph2P)-C6H3SiMe2H (4b, E = S; 4c, E = Se), which were reacted to the E,C,E-supported silyl cations [2,6-(Ph2PE)(2)C6H3SiMe2](+) (5a, E = O, counterion Br-3(-); 5b, E = S, counterion B(C6F5)(4)(-); 5c, E = Se, counterion B(C6F5)(4)(-)), the E,C-supported silyl cations [2-(Ph2PE)-6-(Ph2P)C6H3SiMe2](+) (6b, E = S, not isolated; 6c, E = Se, not isolated), the O,C,S-supported silyl cation [2-(Ph2PS)-6-(Ph2PO)C6H3SiMe2](+) (7, counterion B(C6F5)(4)(-)) as well as the E,C,Au-supported silyl cations [2-(Ph2PAuC6F5)-6-(Ph2PE)C6H3SiMe2](+) (8b, E = S, counterion [B{3,5-(CF3)(2)C6H3}(4)](-); 8c, E = Se, [B{3,5-(CF3)(2)C6H3}(4)](-)) using Br-2, O-2, S-8, (tht)AuC6F5, Ph3C[B(C6F5)(4)] and Ph3C[B{3,5-(CF3)(2)C6H3}(4)]. All compounds were characterized by multinuclear (H-1, C-13, F-19, Si-29, P-31, Se-77) NMR spectroscopy, ESI MS spectrometry and X-ray crystallography (2, 3a center dot H2O, 3b, 3c, 4b, 5a, 5c, 7, 8b, 8c). The gas phase structures of 2, 3a-c, 5a-c (fully optimized) and 8b, 8c (single-point calculations) were studied at the B3PW91/6-311+G(2df,p) level of theory. A set of real-space bonding indicators (RSBIs) derived from the theoretically calculated electron and pair densities were analyzed utilizing the atoms-in molecules (AIM) and electron-localizability indicator (ELI-D) space partitioning schemes
Conformational trimorphism of bis(2,6-dimesitylphenyl)ditelluride
Besides the previously known α-form (monoclinic, P21/c, Z=4) of bis(2,6-dimesitylphenyl)ditelluride, two new polymorphic modifications, namely the β-form (monoclinic, P21/c, Z=8) and the γ-form (triclinic, P1̅, Z=2), were obtained serendipitously during chemical reactions. In all three modifications, the individual molecules possess significantly different conformations and bond parameters, such as Te–Te bond lengths, C–Te–Te bond angles, C–Te–Te–C torsion angles and intramolecular Menshutkin interactions, which is also reflected in their non-covalent interactions with adjacent molecules in the crystal lattice via London dispersion and electrostatic forces. The interplay between intermolecular and intramolecular forces in these conformational polymorphs was investigated using quantum chemical calculations, which reveal that the β-form should be thermodynamically stable at absolute zero. In contrast, crystallization experiments and thermoanalytical investigations indicate that the α-form is stable at high temperatures and therefore, both forms might be related by enantiotropis
Bis(6-diphenylphosphino-acenaphth-5-yl)sulfoxide. A New Ligand for Late Transition Metal Complexes
The synthesis of the new ligand bis(6-diphenylphosphinoacenaphth-5-yl)sulfoxide, [6-(Ph2P)-5-Ace-6](2)-SO (1), is presented along with six transition metal complexes thereof, namely,1 center dot MCl (M = Rh, Cu, Ag, Au) and1 center dot MCl2(M = Ni, Pd). Within these novel complexes, close metal-sulfur distances are observed and the nature of the M-S coordination, as well as the response of the(+)S-O(-)bond, are investigated in detail with a set of spectroscopic, crystallographic and real-space bonding indicators
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