Quantum-Dot Cellular Automata

NASA Astrophysics Data System (ADS)

Snider, Gregory

2000-03-01

Quantum-dot Cellular Automata (QCA) [1] is a promising architecture which employs quantum dots for digital computation. It is a revolutionary approach that holds the promise of high device density and low power dissipation. A basic QCA cell consists of four quantum dots coupled capacitively and by tunnel barriers. The cell is biased to contain two excess electrons within the four dots, which are forced to opposite "corners" of the four-dot cell by mutual Coulomb repulsion. These two possible polarization states of the cell will represent logic "0" and "1". Properly arranged, arrays of these basic cells can implement Boolean logic functions. Experimental results from functional QCA devices built of nanoscale metal dots defined by tunnel barriers will be presented. The experimental devices to be presented consist of Al islands, which we will call quantum dots, interconnected by tunnel junctions and lithographically defined capacitors. Aluminum/ aluminum-oxide/aluminum tunnel junctions were fabricated using a standard e-beam lithography and shadow evaporation technique. The experiments were performed in a dilution refrigerator at a temperature of 70 mK. The operation of a cell is evaluated by direct measurements of the charge state of dots within a cell as the input voltage is changed. The experimental demonstration of a functioning cell will be presented. A line of three cells demonstrates that there are no metastable switching states in a line of cells. A QCA majority gate will also be presented, which is a programmable AND/OR gate and represents the basic building block of QCA systems. The results of recent experiments will be presented. 1. C.S. Lent, P.D. Tougaw, W. Porod, and G.H. Bernstein, Nanotechnology, 4, 49 (1993).

Decorating multi-walled carbon nanotubes with quantum dots for construction of multi-color fluorescent nanoprobes.

PubMed

Jia, Nengqin; Lian, Qiong; Tian, Zhong; Duan, Xin; Yin, Min; Jing, Lihong; Chen, Shouhui; Shen, Hebai; Gao, Mingyuan

2010-01-29

Novel multi-color fluorescent nanoprobes were prepared by electrostatically assembling differently sized CdTe quantum dots on polyethylenimine (PEI) functionalized multi-walled carbon nanotubes (MWNTs). The structural and optical properties of the nano-assemblies (MWNTs-PEI-CdTe) were characterized by transmission electron microscopy (TEM), electron diffraction spectra (EDS), Raman spectroscopy, confocal microscopy and photoluminescence spectroscopy (PL), respectively. Electrochemical impedance spectroscopy (EIS) was also applied to investigate the electrostatic assembling among oxidized MWNTs, PEI and CdTe. Furthermore, confocal fluorescence microscopy was used to monitor the nano-assemblies' delivery into tumor cells. It was found that the nano-assemblies exhibit efficient intracellular transporting and strong intracellular tracking. These properties would make this luminescent nano-assembly an excellent building block for the construction of intracellular nanoprobes, which could hold great promise for biomedical applications.

Characterizing and engineering tunable spin functionality inside indium arsenide/gallium arsenide quantum dot molecules

NASA Astrophysics Data System (ADS)

Liu, Weiwen

The continual downsizing of the basic functional units used in the electronics industry has motivated the study of the quantum computation and related topics. To overcome the limitations of classical physics and engineering, some unique quantum mechanical features, especially entanglement and superpositions have begun to be considered as important properties for future bits. Including these quantum mechanical features is attractive because the ability to utilize quantum mechanics can dramatically enhance computational power. Among the various ways of constructing the basic building blocks for quantum computation, we are particularly interested in using spins inside epitaxially grown InAs/GaAs quantum dot molecules as quantum bits (qubits). The ability to design and engineer nanostructures with tailored quantum properties is critical to engineering quantum computers and other novel electro-optical devices and is one of the key challenges for scaling up new ideas for device application. In this thesis, we will focus on how the structure and composition of quantum dot molecules can be used to control spin properties and charge interactions. Tunable spin and charge properties can enable new, more scalable, methods of initializing and manipulating quantum information. In this thesis, we demonstrate one method to enable electric-field tunability of Zeeman splitting for a single electron spin inside a quantum dot molecules by using heterostructure engineering techniques to modify the barrier that separates quantum dots. We describe how these structural changes to the quantum dot molecules also change charge interactions and propose ways to use this effect to enable accurate measurement of coulomb interactions and possibly charge occupancy inside these complicated quantum dot molecules.

Optimal and Local Connectivity Between Neuron and Synapse Array in the Quantum Dot/Silicon Brain

NASA Technical Reports Server (NTRS)

Duong, Tuan A.; Assad, Christopher; Thakoor, Anikumar P.

2010-01-01

This innovation is used to connect between synapse and neuron arrays using nanowire in quantum dot and metal in CMOS (complementary metal oxide semiconductor) technology to enable the density of a brain-like connection in hardware. The hardware implementation combines three technologies: 1. Quantum dot and nanowire-based compact synaptic cell (50x50 sq nm) with inherently low parasitic capacitance (hence, low dynamic power approx.l0(exp -11) watts/synapse), 2. Neuron and learning circuits implemented in 50-nm CMOS technology, to be integrated with quantum dot and nanowire synapse, and 3. 3D stacking approach to achieve the overall numbers of high density O(10(exp 12)) synapses and O(10(exp 8)) neurons in the overall system. In a 1-sq cm of quantum dot layer sitting on a 50-nm CMOS layer, innovators were able to pack a 10(exp 6)-neuron and 10(exp 10)-synapse array; however, the constraint for the connection scheme is that each neuron will receive a non-identical 10(exp 4)-synapse set, including itself, via its efficacy of the connection. This is not a fully connected system where the 100x100 synapse array only has a 100-input data bus and 100-output data bus. Due to the data bus sharing, it poses a great challenge to have a complete connected system, and its constraint within the quantum dot and silicon wafer layer. For an effective connection scheme, there are three conditions to be met: 1. Local connection. 2. The nanowire should be connected locally, not globally from which it helps to maximize the data flow by sharing the same wire space location. 3. Each synapse can have an alternate summation line if needed (this option is doable based on the simple mask creation). The 10(exp 3)x10(exp 3)-neuron array was partitioned into a 10-block, 10(exp 2)x10(exp 3)-neuron array. This building block can be completely mapped within itself (10,000 synapses to a neuron).

Experimental methods of post-growth tuning of the excitonic fine structure splitting in semiconductor quantum dots

PubMed Central

2012-01-01

Deterministic sources of polarization entangled photon pairs on demand are considered as important building blocks for quantum communication technology. It has been demonstrated that semiconductor quantum dots (QDs), which exhibit a sufficiently small excitonic fine structure splitting (FSS) can be used as triggered, on-chip sources of polarization entangled photon pairs. As-grown QDs usually do not have the required values of the FSS, making the availability of post-growth tuning techniques highly desired. This article reviews the effect of different post-growth treatments and external fields on the FSS such as thermal annealing, magnetic fields, the optical Stark effect, electric fields, and anisotropic stress. As a consequence of the tuning of the FSS, for some tuning techniques a rotation of the polarization of the emitted light is observed. The joint modification of polarization orientation and FSS can be described by an anticrossing of the bright excitonic states. PMID:22726724

The Self-Assembly of Nanogold for Optical Metamaterials

NASA Astrophysics Data System (ADS)

Nidetz, Robert A.

2011-12-01

Optical metamaterials are an emerging field that enables manipulation of light like never before. Producing optical metamaterials requires sub-wavelength building blocks. The focus here was to develop methods to produce building blocks for metamaterials from nanogold. Electron-beam lithography was used to define an aminosilane patterned chemical template in order to electrostatically self-assemble citrate-capped gold nanoparticles. Equilibrium self-assembly was achieved in 20 minutes by immersing chemical templates into gold nanoparticle solutions. The number of nanoparticles that self-assembled on an aminosilane dot was controlled by manipulating the diameters of the dots and nanoparticles. Adding salt to the nanoparticle solution enabled the nanoparticles to self-assemble in greater numbers on the same sized dot. However, the preparation of the nanoparticle solution containing salt was sensitive to spikes in the salt concentration which led to aggregation of the nanoparticles and non-specific deposition. Gold nanorods were also electrostatically self-assembled. Polyelectrolyte-coated gold nanorods were patterned with limited success. A polyelectrolyte chemical template also patterned gold nanorods, but the gold nanorods preferred to pattern on the edges of the pattern. Ligand-exchanged gold nanorods displayed the best self-assembly, but suffered from slow kinetics. Self-assembled gold nanoparticles were cross-linked with poly(diallyldimethylammonium chloride). The poly(diallyldimethylammonium chloride) allowed additional nanoparticles to pattern on top of the already patterned nanoparticles. Cross-linked nanoparticles were lifted-off of the substrate by sonication in a sodium hydroxide solution. The presence of van der Waals forces and/or amine bonding prevent the nanogold from lifting-off without sonication. A good-solvent evaporation process was used to self-assemble poly(styrene) coated gold nanoparticles into spherical microbead assemblies. The use of larger nanoparticles and larger poly(styrene) ligands resulted in larger and smaller assemblies, respectively. Stirring the solution resulted in a wider size distribution of microbead assemblies due to the stirring's shear forces. Two undeveloped methods to self-assemble nanogold were investigated. One method used block-copolymer thin films as chemical templates to direct the electrostatic self-assembly of nanogold. Another method used gold nanorods that are passivated with different ligands on different faces. The stability of an alkanethiol ligand in different acids and bases was investigated to determine which materials could be used to produce Janus nanorods.

49 CFR 41.110 - New DOT owned buildings and additions to buildings.

Code of Federal Regulations, 2011 CFR

2011-10-01

... architect's authenticated verifications of seismic design codes, standards, and practices used in the design... for the design and construction of new DOT Federally owned buildings will ensure that each building is designed and constructed in accord with the seismic design and construction standards set out in § 41.120...

49 CFR 41.119 - DOT regulated buildings.

Code of Federal Regulations, 2011 CFR

2011-10-01

... compliance may include the engineer's and architect's authenticated verification of seismic design codes... and additions to existing buildings will ensure that each DOT regulated building is designed and constructed in accord with seismic design and construction standards as provided by this part. (b) This...

49 CFR 41.119 - DOT regulated buildings.

Code of Federal Regulations, 2010 CFR

2010-10-01

...) Each DOT Operating Administration with responsibility for regulating the structural safety of buildings... section pertains to all new building projects for which development of detailed plans and specifications... regulating the structural safety must comply with the seismic design and construction standards in this part...

Discovery of S···C≡N Intramolecular Bonding in a Thiophenylcyanoacrylate-Based Dye: Realizing Charge Transfer Pathways and Dye···TiO 2 Anchoring Characteristics for Dye-Sensitized Solar Cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cole, Jacqueline M.; Blood-Forsythe, Martin A.; Lin, Tze-Chia

Donor-pi-acceptor dyes containing thiophenyl pi-conjugated units and cyanoacrylate acceptor groups are among the best-performing organic chromophores used in dye-sensitized solar cell (DSC) applications. Yet, the molecular origins of their high photovoltaic output have remained unclear until now. This synchrotron-based X-ray diffraction study elucidates these origins for the high-performance thiophenylcyanoacrylate-based dye MK-2 (7.7% DSC device efficiency) and its molecular building block, MK-44. The crystal structures of MK-2 and MK-44 are both determined, while a high-resolution charge-density mapping of the smaller molecule was also possible, enabling the nature of its bonding to be detailed. A strong S center dot center dot centermore » dot C equivalent to N intramolecular interaction is discovered, which bears a bond critical point, thus proving that this interaction should be formally classified as a chemical bond. A topological analysis of the pi-conjugated portion of MK-44 shows that this S center dot center dot center dot C equivalent to N bonding underpins the highly efficient intramolecular charge transfer(ICT) in thiophenylcyanoacrylate dyes. This manifests as two bipartite ICT pathways bearing carboxylate and nitrile end points. In turn, these pathways dictate a preferred COO/CN anchoring mode for the dye as it adsorbs onto TiO2 surfaces, to form the dye TiO2 interface that constitutes the DSC working electrode. These results corroborate a recent proposal that all cyanoacrylate groups anchor onto TiO2 in this COO/CN binding configuration. Conformational analysis of the MK-44 and MK-2 crystal structures reveals that this S center dot center dot center dot C equivalent to N bonding will persist in MK-2. Accordingly, this newly discovered bond affords a rational explanation for the attractive photovoltaic properties of,MK-2. More generally, this study provides the first unequivocal evidence for an S center dot center dot center dot C equivalent to N interaction, confirming previous speculative assignments of such interactions in other compounds.« less

Two-Dimensional Fluidization of Nanomaterials via Biomimetic Membranes towards Assisted Self Assembly

NASA Astrophysics Data System (ADS)

Kelly, Kathleen

Materials that take advantage of the exceptional properties of nano-meter sized aggregates of atoms are poised to play an important role in future technologies. Prime examples for such nano-materials that have an extremely large surface to volume ratio and thus are physically determined by surface related effects are quantum dots (qdots) and carbon nanotubes (CNTs). The production of such manmade nano-objects has by now become routine and even commercialized. However, the controlled assembly of individual nano-sized building blocks into larger structures of higher geometric and functional complexity has proven to be much more challenging. Yet, this is exactly what is required for many applications that have transformative potential for new technologies. If the tedious procedure to sequentially position individual nano-objects is to be forgone, the assembly of such objects into larger structures needs to be implicitly encoded and many ways to bestow such self-assembly abilities onto nano objects are being developed. Yet, as overall size and complexity of such self-assembled structures increases, kinetic and geometric frustration begin to prevent the system to achieve the desired configuration. In nature, this problem is solved by relying on guided or forced variants of the self-assembly approach. To translate such concepts into the realm of man-made nano-technology, ways to dynamically manipulate nano-materials need to be devised. Thus, in the first part of this work, I provide a proof of concept that supported lipid bilayers (SLBs) that exhibit free lateral diffusion of their constituents can be utilized as a two-dimensional platform for active nano-material manipulation. We used streptavidin coated quantum dots (Q-dots) as a model nano-building-block. Q-dots are 0-dimensional nanomaterials engineered to be fluorescent based solely on their diameter making visualization convenient. Biotinylated lipids were used to tether Q-dots to a SLB and we observed that the 2-dimensional fluidity of the bilayer was translated to the quantum dots as they freely diffused. The quantum dots were visualized using wide-field fluorescent microscopy and single particle tracking techniques were employed to analyze their dynamic behavior. Next, an electric field was applied to the system to induce electroosmotic flow (EOF) which creates a bulk flow of the buffer solution. The quantum dots were again tracked and ballistic motion was observed in the particle tracks due to the electroosmosis in the system. This proved that SLBs could be used as a two-dimensional fluid platform for nanomaterials and electroosmosis can be used to manipulate the motion of the Q-dots once they are tethered to the membrane. Next, we set out to employ the same technique to carbon nanotubes (CNTs), which are known for their highly versatile mechanical and electrical properties. However, carbon nanotubes are extremely hydrophobic and tend to aggregate in aqueous solutions which negatively impacts the viability of tethering the CNTs to the bilayer, fluorescently staining and then imaging them. First, we had to solubilize the CNTs such that they were monodisperse and characterize the CNT-detergent solutions. We were able to create monodisperse solutions of CNTs such that the detergent levels were low enough that the integrity of the bilayer was intact. We were also able to fluorescently label the CNTs in order to visualize them, and tether them to a SLB using a peptide sequence. Future directions of this project would include employing EOF to mobilize the CNTs and use a more sophisticated single particle tracking software to track individual CNTs and analyze their motion.

49 CFR 41.115 - New buildings to be leased for DOT occupancy.

Code of Federal Regulations, 2011 CFR

2011-10-01

... compliance may include the engineer's and architect's authenticated verifications of seismic design codes... design and construction of new buildings to be leased for DOT occupancy or use will ensure that each building is designed and constructed in accord with the seismic design and construction standards set out...

49 CFR 41.115 - New buildings to be leased for DOT occupancy.

Code of Federal Regulations, 2010 CFR

2010-10-01

... compliance may include the engineer's and architect's authenticated verifications of seismic design codes... design and construction of new buildings to be leased for DOT occupancy or use will ensure that each building is designed and constructed in accord with the seismic design and construction standards set out...

Method of holding optical elements without deformation during their fabrication

DOEpatents

Hed, P.P.

1997-04-29

An improved method for securing and removing an optical element to and from a blocking tool without causing deformation of the optical element is disclosed. A lens tissue is placed on the top surface of the blocking tool. Dots of UV cement are applied to the lens tissue without any of the dots contacting each other. An optical element is placed on top of the blocking tool with the lens tissue sandwiched therebetween. The UV cement is then cured. After subsequent fabrication steps, the bonded blocking tool, lens tissue, and optical element are placed in a debonding solution to soften the UV cement. The optical element is then removed from the blocking tool. 16 figs.

Method of holding optical elements without deformation during their fabrication

DOEpatents

Hed, P. Paul

1997-01-01

An improved method for securing and removing an optical element to and from a blocking tool without causing deformation of the optical element. A lens tissue is placed on the top surface of the blocking tool. Dots of UV cement are applied to the lens tissue without any of the dots contacting each other. An optical element is placed on top of the blocking tool with the lens tissue sandwiched therebetween. The UV cement is then cured. After subsequent fabrication steps, the bonded blocking tool, lens tissue, and optical element are placed in a debonding solution to soften the UV cement. The optical element is then removed from the blocking tool.

Quasi-classical modeling of molecular quantum-dot cellular automata multidriver gates

NASA Astrophysics Data System (ADS)

Rahimi, Ehsan; Nejad, Shahram Mohammad

2012-05-01

Molecular quantum-dot cellular automata (mQCA) has received considerable attention in nanoscience. Unlike the current-based molecular switches, where the digital data is represented by the on/off states of the switches, in mQCA devices, binary information is encoded in charge configuration within molecular redox centers. The mQCA paradigm allows high device density and ultra-low power consumption. Digital mQCA gates are the building blocks of circuits in this paradigm. Design and analysis of these gates require quantum chemical calculations, which are demanding in computer time and memory. Therefore, developing simple models to probe mQCA gates is of paramount importance. We derive a semi-classical model to study the steady-state output polarization of mQCA multidriver gates, directly from the two-state approximation in electron transfer theory. The accuracy and validity of this model are analyzed using full quantum chemistry calculations. A complete set of logic gates, including inverters and minority voters, are implemented to provide an appropriate test bench in the two-dot mQCA regime. We also briefly discuss how the QCADesigner tool could find its application in simulation of mQCA devices.

Green-noise halftoning with dot diffusion

NASA Astrophysics Data System (ADS)

Lippens, Stefaan; Philips, Wilfried

2007-02-01

Dot diffusion is a halftoning technique that is based on the traditional error diffusion concept, but offers a high degree of parallel processing by its block based approach. Traditional dot diffusion however suffers from periodicity artifacts. To limit the visibility of these artifacts, we propose grid diffusion, which applies different class matrices for different blocks. Furthermore, in this paper we will discuss two approaches in the dot diffusion framework to generate green-noise halftone patterns. The first approach is based on output dependent feedback (hysteresis), analogous to the standard green-noise error diffusion techniques. We observe that the resulting halftones are rather coarse and highly dependent on the used dot diffusion class matrices. In the second approach we don't limit the diffusion to the nearest neighbors. This leads to less coarse halftones, compared to the first approach. The drawback is that it can only cope with rather limited cluster sizes. We can reduce these drawbacks by combining the two approaches.

Use of CdS quantum dot-functionalized cellulose nanocrystal films for anti-counterfeiting applications

NASA Astrophysics Data System (ADS)

Chen, L.; Lai, C.; Marchewka, R.; Berry, R. M.; Tam, K. C.

2016-07-01

Structural colors and photoluminescence have been widely used for anti-counterfeiting and security applications. We report for the first time the use of CdS quantum dot (QD)-functionalized cellulose nanocrystals (CNCs) as building blocks to fabricate nanothin films via layer-by-layer (LBL) self-assembly for anti-counterfeiting applications. Both negatively- and positively-charged CNC/QD nanohybrids with a high colloidal stability and a narrow particle size distribution were prepared. The controllable LBL coating process was characterized by scanning electron microscopy and ellipsometry. The rigid structure of CNCs leads to nanoporous structured films on poly(ethylene terephthalate) (PET) substrates with high transmittance (above 70%) over the entire range of visible light and also resulted in increased hydrophilicity (contact angles of ~40 degrees). Nanothin films on PET substrates showed good flexibility and enhanced stability in both water and ethanol. The modified PET films with structural colors from thin-film interference and photoluminescence from QDs can be used in anti-counterfeiting applications.Structural colors and photoluminescence have been widely used for anti-counterfeiting and security applications. We report for the first time the use of CdS quantum dot (QD)-functionalized cellulose nanocrystals (CNCs) as building blocks to fabricate nanothin films via layer-by-layer (LBL) self-assembly for anti-counterfeiting applications. Both negatively- and positively-charged CNC/QD nanohybrids with a high colloidal stability and a narrow particle size distribution were prepared. The controllable LBL coating process was characterized by scanning electron microscopy and ellipsometry. The rigid structure of CNCs leads to nanoporous structured films on poly(ethylene terephthalate) (PET) substrates with high transmittance (above 70%) over the entire range of visible light and also resulted in increased hydrophilicity (contact angles of ~40 degrees). Nanothin films on PET substrates showed good flexibility and enhanced stability in both water and ethanol. The modified PET films with structural colors from thin-film interference and photoluminescence from QDs can be used in anti-counterfeiting applications. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr03039d

Nanodiamond-based nanostructures for coupling nitrogen-vacancy centres to metal nanoparticles and semiconductor quantum dots

DOE PAGES

Gong, Jianxiao; Steinsultz, Nat; Ouyang, Min

2016-06-08

The ability to control the interaction between nitrogen-vacancy centres in diamond and photonic and/or broadband plasmonic nanostructures is crucial for the development of solid-state quantum devices with optimum performance. However, existing methods typically employ top-down fabrication, which restrict scalable and feasible manipulation of nitrogen-vacancy centres. Here, we develop a general bottom-up approach to fabricate an emerging class of freestanding nanodiamond-based hybrid nanostructures with external functional units of either plasmonic nanoparticles or excitonic quantum dots. Precise control of the structural parameters ( including size, composition, coverage and spacing of the external functional units) is achieved, representing a pre-requisite for exploring themore » underlying physics. Fine tuning of the emission characteristics through structural regulation is demonstrated by performing single-particle optical studies. Lastly, this study opens a rich toolbox to tailor properties of quantum emitters, which can facilitate design guidelines for devices based on nitrogen vacancy centres that use these freestanding hybrid nanostructures as building blocks.« less

Crystal symmetry breaking and vacancies in colloidal lead chalcogenide quantum dots.

PubMed

Bertolotti, Federica; Dirin, Dmitry N; Ibáñez, Maria; Krumeich, Frank; Cervellino, Antonio; Frison, Ruggero; Voznyy, Oleksandr; Sargent, Edward H; Kovalenko, Maksym V; Guagliardi, Antonietta; Masciocchi, Norberto

2016-09-01

Size and shape tunability and low-cost solution processability make colloidal lead chalcogenide quantum dots (QDs) an emerging class of building blocks for innovative photovoltaic, thermoelectric and optoelectronic devices. Lead chalcogenide QDs are known to crystallize in the rock-salt structure, although with very different atomic order and stoichiometry in the core and surface regions; however, there exists no convincing prior identification of how extreme downsizing and surface-induced ligand effects influence structural distortion. Using forefront X-ray scattering techniques and density functional theory calculations, here we have identified that, at sizes below 8 nm, PbS and PbSe QDs undergo a lattice distortion with displacement of the Pb sublattice, driven by ligand-induced tensile strain. The resulting permanent electric dipoles may have implications on the oriented attachment of these QDs. Evidence is found for a Pb-deficient core and, in the as-synthesized QDs, for a rhombic dodecahedral shape with nonpolar {110} facets. On varying the nature of the surface ligands, differences in lattice strains are found.

Crystal symmetry breaking and vacancies in colloidal lead chalcogenide quantum dots

NASA Astrophysics Data System (ADS)

Bertolotti, Federica; Dirin, Dmitry N.; Ibáñez, Maria; Krumeich, Frank; Cervellino, Antonio; Frison, Ruggero; Voznyy, Oleksandr; Sargent, Edward H.; Kovalenko, Maksym V.; Guagliardi, Antonietta; Masciocchi, Norberto

2016-09-01

Size and shape tunability and low-cost solution processability make colloidal lead chalcogenide quantum dots (QDs) an emerging class of building blocks for innovative photovoltaic, thermoelectric and optoelectronic devices. Lead chalcogenide QDs are known to crystallize in the rock-salt structure, although with very different atomic order and stoichiometry in the core and surface regions; however, there exists no convincing prior identification of how extreme downsizing and surface-induced ligand effects influence structural distortion. Using forefront X-ray scattering techniques and density functional theory calculations, here we have identified that, at sizes below 8 nm, PbS and PbSe QDs undergo a lattice distortion with displacement of the Pb sublattice, driven by ligand-induced tensile strain. The resulting permanent electric dipoles may have implications on the oriented attachment of these QDs. Evidence is found for a Pb-deficient core and, in the as-synthesized QDs, for a rhombic dodecahedral shape with nonpolar {110} facets. On varying the nature of the surface ligands, differences in lattice strains are found.

Fluorescent nanosensors via photoinduced polymerization of hydrophobic inorganic quantum dots for the sensitive and selective detection of nitroaromatics.

PubMed

Bai, Min; Huang, Shuina; Xu, Suying; Hu, Gaofei; Wang, Leyu

2015-02-17

We developed an efficient one-pot strategy for the preparation of hydrophilic amine-functionalized nanocomposites by using hydrophobic fluorescence quantum dots ZnS:Mn(2+)@allyl mercaptan (QDs@AM) as building blocks through novel light-induced in situ polymerization. The average size of as-prepared hydrophilic nanocomposites was ∼50 nm, which could be further tuned by varying the concentrations of the monomers. Importantly, these nanocomposites were further utilized for the facile, highly sensitive, and selective detection of nitroaromatics. The linear ranges for 2,4,6-trinitrotoluene (TNT) and 2,4,6-trinitrophenol (TNP) lie in 0.01-0.5 μg/mL and 0.05-8.0 μg/mL, respectively, barely interfered with by other nitroaromatics such as 2,4-dinitrotoluene (DNT) and nitrobenzene (NB). Moreover, the novel surface modification method developed here offered a general strategy for fabricating hydrophobic nanocomposites with hydrophilic properties and indicated various potential applications including sensing and imaging.

Two-axis control of a singlet-triplet qubit with an integrated micromagnet.

DOE PAGES

Wu, Xian; Ward, D. R.; Prance, J. R.; ...

2014-08-04

The qubit is the fundamental building block of a quantum computer. We fabricate a qubit in a silicon double-quantum dot with an integrated micromagnet in which the qubit basis states are the singlet state and the spin-zero triplet state of two electrons. Because of the micromagnet, the magnetic field difference ΔB between the two sides of the double dot is large enough to enable the achievement of coherent rotation of the qubit’s Bloch vector around two different axes of the Bloch sphere. By measuring the decay of the quantum oscillations, the inhomogeneous spin coherence time T*2 is determined. By measuringmore » T*2 at many different values of the exchange coupling J and at two different values of ΔB, we provide evidence that the micromagnet does not limit decoherence, with the dominant limits on T*2 arising from charge noise and from coupling to nuclear spins.« less

A Pt-Co3O4-CD electrocatalyst with enhanced electrocatalytic performance and resistance to CO poisoning achieved by carbon dots and Co3O4 for direct methanol fuel cells.

PubMed

Sun, Yue; Zhou, Yunjie; Zhu, Cheng; Hu, Lulu; Han, Mumei; Wang, Aoqi; Huang, Hui; Liu, Yang; Kang, Zhenhui

2017-05-04

Highly efficient electrocatalysts remain huge challenges in direct methanol fuel cells (DMFCs). Here, a Pt-Co 3 O 4 -CDs/C composite was fabricated as an anode electrocatalyst with low Pt content (12 wt%) by using carbon dots (CDs) and Co 3 O 4 nanoparticles as building blocks. The Pt-Co 3 O 4 -CDs/C composite catalyst shows a significantly enhanced electrocatalytic activity (1393.3 mA mg -1 Pt), durability (over 4000 s) and CO-poisoning tolerance. The superior catalytic activity should be attributed to the synergistic effect of CDs, Pt and Co 3 O 4 . Furthermore, the Pt-Co 3 O 4 -CDs/C catalyst was integrated into a single cell, which exhibits a maximum power density of 45.6 mW cm -2 , 1.7 times the cell based on the commercial 20 wt% Pt/C catalyst.

Sandwiched confinement of quantum dots in graphene matrix for efficient electron transfer and photocurrent production

PubMed Central

Zhu, Nan; Zheng, Kaibo; Karki, Khadga J.; Abdellah, Mohamed; Zhu, Qiushi; Carlson, Stefan; Haase, Dörthe; Žídek, Karel; Ulstrup, Jens; Canton, Sophie E.; Pullerits, Tõnu; Chi, Qijin

2015-01-01

Quantum dots (QDs) and graphene are both promising materials for the development of new-generation optoelectronic devices. Towards this end, synergic assembly of these two building blocks is a key step but remains a challenge. Here, we show a one-step strategy for organizing QDs in a graphene matrix via interfacial self-assembly, leading to the formation of sandwiched hybrid QD-graphene nanofilms. We have explored structural features, electron transfer kinetics and photocurrent generation capacity of such hybrid nanofilms using a wide variety of advanced techniques. Graphene nanosheets interlink QDs and significantly improve electronic coupling, resulting in fast electron transfer from photoexcited QDs to graphene with a rate constant of 1.3 × 109 s−1. Efficient electron transfer dramatically enhances photocurrent generation in a liquid-junction QD-sensitized solar cell where the hybrid nanofilm acts as a photoanode. We thereby demonstrate a cost-effective method to construct large-area QD-graphene hybrid nanofilms with straightforward scale-up potential for optoelectronic applications. PMID:25996307

Nanodiamond-based nanostructures for coupling nitrogen-vacancy centres to metal nanoparticles and semiconductor quantum dots

NASA Astrophysics Data System (ADS)

Gong, Jianxiao; Steinsultz, Nat; Ouyang, Min

2016-06-01

The ability to control the interaction between nitrogen-vacancy centres in diamond and photonic and/or broadband plasmonic nanostructures is crucial for the development of solid-state quantum devices with optimum performance. However, existing methods typically employ top-down fabrication, which restrict scalable and feasible manipulation of nitrogen-vacancy centres. Here, we develop a general bottom-up approach to fabricate an emerging class of freestanding nanodiamond-based hybrid nanostructures with external functional units of either plasmonic nanoparticles or excitonic quantum dots. Precise control of the structural parameters (including size, composition, coverage and spacing of the external functional units) is achieved, representing a pre-requisite for exploring the underlying physics. Fine tuning of the emission characteristics through structural regulation is demonstrated by performing single-particle optical studies. This study opens a rich toolbox to tailor properties of quantum emitters, which can facilitate design guidelines for devices based on nitrogen-vacancy centres that use these freestanding hybrid nanostructures as building blocks.

Selective far-field addressing of coupled quantum dots in a plasmonic nanocavity.

PubMed

Tang, Jianwei; Xia, Juan; Fang, Maodong; Bao, Fanglin; Cao, Guanjun; Shen, Jianqi; Evans, Julian; He, Sailing

2018-04-27

Plasmon-emitter hybrid nanocavity systems exhibit strong plasmon-exciton interactions at the single-emitter level, showing great potential as testbeds and building blocks for quantum optics and informatics. However, reported experiments involve only one addressable emitting site, which limits their relevance for many fundamental questions and devices involving interactions among emitters. Here we open up this critical degree of freedom by demonstrating selective far-field excitation and detection of two coupled quantum dot emitters in a U-shaped gold nanostructure. The gold nanostructure functions as a nanocavity to enhance emitter interactions and a nanoantenna to make the emitters selectively excitable and detectable. When we selectively excite or detect either emitter, we observe photon emission predominantly from the target emitter with up to 132-fold Purcell-enhanced emission rate, indicating individual addressability and strong plasmon-exciton interactions. Our work represents a step towards a broad class of plasmonic devices that will enable faster, more compact optics, communication and computation.

Sandwiched confinement of quantum dots in graphene matrix for efficient electron transfer and photocurrent production

NASA Astrophysics Data System (ADS)

Zhu, Nan; Zheng, Kaibo; Karki, Khadga J.; Abdellah, Mohamed; Zhu, Qiushi; Carlson, Stefan; Haase, Dörthe; Žídek, Karel; Ulstrup, Jens; Canton, Sophie E.; Pullerits, Tõnu; Chi, Qijin

2015-05-01

Quantum dots (QDs) and graphene are both promising materials for the development of new-generation optoelectronic devices. Towards this end, synergic assembly of these two building blocks is a key step but remains a challenge. Here, we show a one-step strategy for organizing QDs in a graphene matrix via interfacial self-assembly, leading to the formation of sandwiched hybrid QD-graphene nanofilms. We have explored structural features, electron transfer kinetics and photocurrent generation capacity of such hybrid nanofilms using a wide variety of advanced techniques. Graphene nanosheets interlink QDs and significantly improve electronic coupling, resulting in fast electron transfer from photoexcited QDs to graphene with a rate constant of 1.3 × 109 s-1. Efficient electron transfer dramatically enhances photocurrent generation in a liquid-junction QD-sensitized solar cell where the hybrid nanofilm acts as a photoanode. We thereby demonstrate a cost-effective method to construct large-area QD-graphene hybrid nanofilms with straightforward scale-up potential for optoelectronic applications.

Use of CdS quantum dot-functionalized cellulose nanocrystal films for anti-counterfeiting applications.

PubMed

Chen, L; Lai, C; Marchewka, R; Berry, R M; Tam, K C

2016-07-21

Structural colors and photoluminescence have been widely used for anti-counterfeiting and security applications. We report for the first time the use of CdS quantum dot (QD)-functionalized cellulose nanocrystals (CNCs) as building blocks to fabricate nanothin films via layer-by-layer (LBL) self-assembly for anti-counterfeiting applications. Both negatively- and positively-charged CNC/QD nanohybrids with a high colloidal stability and a narrow particle size distribution were prepared. The controllable LBL coating process was characterized by scanning electron microscopy and ellipsometry. The rigid structure of CNCs leads to nanoporous structured films on poly(ethylene terephthalate) (PET) substrates with high transmittance (above 70%) over the entire range of visible light and also resulted in increased hydrophilicity (contact angles of ∼40 degrees). Nanothin films on PET substrates showed good flexibility and enhanced stability in both water and ethanol. The modified PET films with structural colors from thin-film interference and photoluminescence from QDs can be used in anti-counterfeiting applications.

The fabrication of highly ordered block copolymer micellar arrays: control of the separation distances of silicon oxide dots

NASA Astrophysics Data System (ADS)

Yoo, Hana; Park, Soojin

2010-06-01

We demonstrate the fabrication of highly ordered silicon oxide dotted arrays prepared from polydimethylsiloxane (PDMS) filled nanoporous block copolymer (BCP) films and the preparation of nanoporous, flexible Teflon or polyimide films. Polystyrene-block-poly(2-vinylpyridine) (PS-b-P2VP) films were annealed in toluene vapor to enhance the lateral order of micellar arrays and were subsequently immersed in alcohol to produce nano-sized pores, which can be used as templates for filling a thin layer of PDMS. When a thin layer of PDMS was spin-coated onto nanoporous BCP films and thermally annealed at a certain temperature, the PDMS was drawn into the pores by capillary action. PDMS filled BCP templates were exposed to oxygen plasma environments in order to fabricate silicon oxide dotted arrays. By addition of PS homopolymer to PS-b-P2VP copolymer, the separation distances of micellar arrays were tuned. As-prepared silicon oxide dotted arrays were used as a hard master for fabricating nanoporous Teflon or polyimide films by spin-coating polymer precursor solutions onto silicon patterns and peeling off. This simple process enables us to fabricate highly ordered nanoporous BCP templates, silicon oxide dots, and flexible nanoporous polymer patterns with feature size of sub-20 nm over 5 cm × 5 cm.

The fabrication of highly ordered block copolymer micellar arrays: control of the separation distances of silicon oxide dots.

PubMed

Yoo, Hana; Park, Soojin

2010-06-18

We demonstrate the fabrication of highly ordered silicon oxide dotted arrays prepared from polydimethylsiloxane (PDMS) filled nanoporous block copolymer (BCP) films and the preparation of nanoporous, flexible Teflon or polyimide films. Polystyrene-block-poly(2-vinylpyridine) (PS-b-P2VP) films were annealed in toluene vapor to enhance the lateral order of micellar arrays and were subsequently immersed in alcohol to produce nano-sized pores, which can be used as templates for filling a thin layer of PDMS. When a thin layer of PDMS was spin-coated onto nanoporous BCP films and thermally annealed at a certain temperature, the PDMS was drawn into the pores by capillary action. PDMS filled BCP templates were exposed to oxygen plasma environments in order to fabricate silicon oxide dotted arrays. By addition of PS homopolymer to PS-b-P2VP copolymer, the separation distances of micellar arrays were tuned. As-prepared silicon oxide dotted arrays were used as a hard master for fabricating nanoporous Teflon or polyimide films by spin-coating polymer precursor solutions onto silicon patterns and peeling off. This simple process enables us to fabricate highly ordered nanoporous BCP templates, silicon oxide dots, and flexible nanoporous polymer patterns with feature size of sub-20 nm over 5 cm x 5 cm.

Interface induced spin-orbit interaction in silicon quantum dots and prospects of scalability

NASA Astrophysics Data System (ADS)

Ferdous, Rifat; Wai, Kok; Veldhorst, Menno; Hwang, Jason; Yang, Henry; Klimeck, Gerhard; Dzurak, Andrew; Rahman, Rajib

A scalable quantum computing architecture requires reproducibility over key qubit properties, like resonance frequency, coherence time etc. Randomness in these properties would necessitate individual knowledge of each qubit in a quantum computer. Spin qubits hosted in Silicon (Si) quantum dots (QD) is promising as a potential building block for a large-scale quantum computer, because of their longer coherence times. The Stark shift of the electron g-factor in these QDs has been used to selectively address multiple qubits. From atomistic tight-binding studies we investigated the effect of interface non-ideality on the Stark shift of the g-factor in a Si QD. We find that based on the location of a monoatomic step at the interface with respect to the dot center both the sign and magnitude of the Stark shift change. Thus the presence of interface steps in these devices will cause variability in electron g-factor and its Stark shift based on the location of the qubit. This behavior will also cause varying sensitivity to charge noise from one qubit to another, which will randomize the dephasing times T2*. This predicted device-to-device variability is experimentally observed recently in three qubits fabricated at a Si/Si02 interface, which validates the issues discussed.

Circuit quantum electrodynamics with a spin qubit.

PubMed

Petersson, K D; McFaul, L W; Schroer, M D; Jung, M; Taylor, J M; Houck, A A; Petta, J R

2012-10-18

Electron spins trapped in quantum dots have been proposed as basic building blocks of a future quantum processor. Although fast, 180-picosecond, two-quantum-bit (two-qubit) operations can be realized using nearest-neighbour exchange coupling, a scalable, spin-based quantum computing architecture will almost certainly require long-range qubit interactions. Circuit quantum electrodynamics (cQED) allows spatially separated superconducting qubits to interact via a superconducting microwave cavity that acts as a 'quantum bus', making possible two-qubit entanglement and the implementation of simple quantum algorithms. Here we combine the cQED architecture with spin qubits by coupling an indium arsenide nanowire double quantum dot to a superconducting cavity. The architecture allows us to achieve a charge-cavity coupling rate of about 30 megahertz, consistent with coupling rates obtained in gallium arsenide quantum dots. Furthermore, the strong spin-orbit interaction of indium arsenide allows us to drive spin rotations electrically with a local gate electrode, and the charge-cavity interaction provides a measurement of the resulting spin dynamics. Our results demonstrate how the cQED architecture can be used as a sensitive probe of single-spin physics and that a spin-cavity coupling rate of about one megahertz is feasible, presenting the possibility of long-range spin coupling via superconducting microwave cavities.

Blocking-state influence on shot noise and conductance in quantum dots

NASA Astrophysics Data System (ADS)

Harabula, M.-C.; Ranjan, V.; Haller, R.; Fülöp, G.; Schönenberger, C.

2018-03-01

Quantum dots (QDs) investigated through electron transport measurements often exhibit varying, state-dependent tunnel couplings to the leads. Under specific conditions, weakly coupled states can result in a strong suppression of the electrical current, and they are correspondingly called blocking states. Using the combination of conductance and shot noise measurements, we investigate blocking states in carbon nanotube (CNT) QDs. We report negative differential conductance and super-Poissonian noise. The enhanced noise is the signature of electron bunching, which originates from random switches between the strongly and weakly conducting states of the QD. Negative differential conductance appears here when the blocking state is an excited state. In this case, at the threshold voltage where the blocking state becomes populated, the current is reduced. Using a master equation approach, we provide numerical simulations reproducing both the conductance and the shot noise pattern observed in our measurements.

Flux density calibration in diffuse optical tomographic systems.

PubMed

Biswas, Samir Kumar; Rajan, Kanhirodan; Vasu, Ram M

2013-02-01

The solution of the forward equation that models the transport of light through a highly scattering tissue material in diffuse optical tomography (DOT) using the finite element method gives flux density (Φ) at the nodal points of the mesh. The experimentally measured flux (Umeasured) on the boundary over a finite surface area in a DOT system has to be corrected to account for the system transfer functions (R) of various building blocks of the measurement system. We present two methods to compensate for the perturbations caused by R and estimate true flux density (Φ) from Umeasuredcal. In the first approach, the measurement data with a homogeneous phantom (Umeasuredhomo) is used to calibrate the measurement system. The second scheme estimates the homogeneous phantom measurement using only the measurement from a heterogeneous phantom, thereby eliminating the necessity of a homogeneous phantom. This is done by statistically averaging the data (Umeasuredhetero) and redistributing it to the corresponding detector positions. The experiments carried out on tissue mimicking phantom with single and multiple inhomogeneities, human hand, and a pork tissue phantom demonstrate the robustness of the approach.

Artificial Neuron Based on Integrated Semiconductor Quantum Dot Mode-Locked Lasers

NASA Astrophysics Data System (ADS)

Mesaritakis, Charis; Kapsalis, Alexandros; Bogris, Adonis; Syvridis, Dimitris

2016-12-01

Neuro-inspired implementations have attracted strong interest as a power efficient and robust alternative to the digital model of computation with a broad range of applications. Especially, neuro-mimetic systems able to produce and process spike-encoding schemes can offer merits like high noise-resiliency and increased computational efficiency. Towards this direction, integrated photonics can be an auspicious platform due to its multi-GHz bandwidth, its high wall-plug efficiency and the strong similarity of its dynamics under excitation with biological spiking neurons. Here, we propose an integrated all-optical neuron based on an InAs/InGaAs semiconductor quantum-dot passively mode-locked laser. The multi-band emission capabilities of these lasers allows, through waveband switching, the emulation of the excitation and inhibition modes of operation. Frequency-response effects, similar to biological neural circuits, are observed just as in a typical two-section excitable laser. The demonstrated optical building block can pave the way for high-speed photonic integrated systems able to address tasks ranging from pattern recognition to cognitive spectrum management and multi-sensory data processing.

Artificial Neuron Based on Integrated Semiconductor Quantum Dot Mode-Locked Lasers

PubMed Central

Mesaritakis, Charis; Kapsalis, Alexandros; Bogris, Adonis; Syvridis, Dimitris

2016-01-01

Neuro-inspired implementations have attracted strong interest as a power efficient and robust alternative to the digital model of computation with a broad range of applications. Especially, neuro-mimetic systems able to produce and process spike-encoding schemes can offer merits like high noise-resiliency and increased computational efficiency. Towards this direction, integrated photonics can be an auspicious platform due to its multi-GHz bandwidth, its high wall-plug efficiency and the strong similarity of its dynamics under excitation with biological spiking neurons. Here, we propose an integrated all-optical neuron based on an InAs/InGaAs semiconductor quantum-dot passively mode-locked laser. The multi-band emission capabilities of these lasers allows, through waveband switching, the emulation of the excitation and inhibition modes of operation. Frequency-response effects, similar to biological neural circuits, are observed just as in a typical two-section excitable laser. The demonstrated optical building block can pave the way for high-speed photonic integrated systems able to address tasks ranging from pattern recognition to cognitive spectrum management and multi-sensory data processing. PMID:27991574

Silica based hybrid materials for drug delivery and bioimaging.

PubMed

Bagheri, Elnaz; Ansari, Legha; Abnous, Khalil; Taghdisi, Seyed Mohammad; Charbgoo, Fahimeh; Ramezani, Mohammad; Alibolandi, Mona

2018-05-10

Silica hybrid materials play an important role in improvement of novel progressive functional nanomaterials. Study in silica hybrid functional materials is supported by growing interest in providing intelligent materials that combine best of the inorganic silica structure along with organic or biological realms. Hybrid silica materials do not only provide fantastic opportunities for the design of novel materials for research but their represented unique properties open versatile applications specifically in nanomedicine since it was recognized by US FDA as a safe material for human trials. By combining various materials with different characteristics along with silica NPs as building blocks, silica-based hybrid vehicles were developed. In this regard, silica-based hybrid materials have shown great capabilities as unique carriers for bioimaging and/or drug delivery purposes. In the aforementioned hybrid systems, silica was preferred as a main building block of the hybrid structure, which is easily functionalized with different materials, bio-molecules and targeting ligands while providing biocompatibility for the system. This review will cover a full description of different hybrids of silica nanoparticles including silica-polymer, silica-protein, silica-peptide, silica-nucleic acid, silica-gold, silica-quantum dot, and silica-magnetic nanoparticles and their applications as therapeutic or imaging systems. Copyright © 2018 Elsevier B.V. All rights reserved.

MASH test 3-10 on 31-inch w-beam guardrail with standard offset blocks

DOT National Transportation Integrated Search

2011-03-01

The Texas Department of Transportation (TxDOT) initiated a review of their guardrail standards : based on the outcome of recent crash test results and a Federal Highway Administration technical : memorandum pertaining to guardrail height. TxDOT expre...

Poster – 41: External marker block placement on the breast or chest wall for left-sided deep inspiration breath-hold radiotherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Conroy, Leigh; Guebert, Alexandra; Smith, Wendy

Purpose: We investigate DIBH breast radiotherapy using the Real-time Position Management (RPM) system with the marker-block placed on the target breast or chest wall. Methods: We measured surface dose for three different RPM marker-blocks using EBT3 Gafchromic film at 0° and 30° incidence. A registration study was performed to determine the breast surface position that best correlates with overall internal chest wall position. Surface and chest wall contours from MV images of the medial tangent field were extracted for 15 patients. Surface contours were divided into three potential marker-block positions on the breast: Superior, Middle, and Inferior. Translational registration wasmore » used to align the partial contours to the first-fraction contour. Each resultant transformation matrix was applied to the chest wall contour, and the minimum distance between the reference chest wall contour and the transformed chest wall contour was evaluated for each pixel. Results: The measured surface dose for the 2-dot, 6-dot, and 4-dot marker-blocks at 0° incidence were 74%, 71%, and 77% of dose to dmax respectively. At 30° beam incidence this increased to 76%, 72%, and 81%. The best external surface position was patient and fraction dependent, with no consistent best choice. Conclusions: The increase in surface dose directly under the RPM block is approximately equivalent to 3 mm of bolus. No marker-block position on the breast surface was found to be more representative of overall chest wall motion; therefore block positional stability and reproducibility can be used to determine optimal placement on the breast or chest wall.« less

77 FR 36039 - Federal Interagency Committee on Emergency Medical Services

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-15

... Traffic Safety Administration (NHTSA), DOT. ACTION: Meeting Notice--Federal Interagency Committee on...: The meeting will be held at the Department of Transportation (DOT) Headquarters Building at 1200 New..., Telephone number (202) 366-9966; Email [email protected]dot.gov . Required Registration Information: This meeting...

Graphene-based vertical-junction diodes and applications

NASA Astrophysics Data System (ADS)

Choi, Suk-Ho

2017-09-01

In the last decade, graphene has received extreme attention as an intriguing building block for electronic and photonic device applications. This paper provides an overview of recent progress in the study of vertical-junction diodes based on graphene and its hybrid systems by combination of graphene and other materials. The review is especially focused on tunnelling and Schottky diodes produced by chemical doping of graphene or combination of graphene with various semiconducting/ insulating materials such as hexagonal boron nitrides, Si-quantum-dots-embedded SiO2 multilayers, Si wafers, compound semiconductors, Si nanowires, and porous Si. The uniqueness of graphene enables the application of these convergence structures in high-efficient devices including photodetectors, solar cells, resonant tunnelling diodes, and molecular/DNA sensors.

Structural Color Patterns by Electrohydrodynamic Jet Printed Photonic Crystals.

PubMed

Ding, Haibo; Zhu, Cun; Tian, Lei; Liu, Cihui; Fu, Guangbin; Shang, Luoran; Gu, Zhongze

2017-04-05

In this work, we demonstrate the fabrication of photonic crystal patterns with controllable morphologies and structural colors utilizing electrohydrodynamic jet (E-jet) printing with colloidal crystal inks. The final shape of photonic crystal units is controlled by the applied voltage signal and wettability of the substrate. Optical properties of the structural color patterns are tuned by the self-assembly of the silica nanoparticle building blocks. Using this direct printing technique, it is feasible to print customized functional patterns composed of photonic crystal dots or photonic crystal lines according to relevant printing mode and predesigned tracks. This is the first report for E-jet printing with colloidal crystal inks. Our results exhibit promising applications in displays, biosensors, and other functional devices.

Flexible single-layer ionic organic-inorganic frameworks towards precise nano-size separation

NASA Astrophysics Data System (ADS)

Yue, Liang; Wang, Shan; Zhou, Ding; Zhang, Hao; Li, Bao; Wu, Lixin

2016-02-01

Consecutive two-dimensional frameworks comprised of molecular or cluster building blocks in large area represent ideal candidates for membranes sieving molecules and nano-objects, but challenges still remain in methodology and practical preparation. Here we exploit a new strategy to build soft single-layer ionic organic-inorganic frameworks via electrostatic interaction without preferential binding direction in water. Upon consideration of steric effect and additional interaction, polyanionic clusters as connection nodes and cationic pseudorotaxanes acting as bridging monomers connect with each other to form a single-layer ionic self-assembled framework with 1.4 nm layer thickness. Such soft supramolecular polymer frameworks possess uniform and adjustable ortho-tetragonal nanoporous structure in pore size of 3.4-4.1 nm and exhibit greatly convenient solution processability. The stable membranes maintaining uniform porous structure demonstrate precisely size-selective separation of semiconductor quantum dots within 0.1 nm of accuracy and may hold promise for practical applications in selective transport, molecular separation and dialysis systems.

Controlled Growth of CdS Quantum Dot in an Amphiphilic Diblock Copolymer Poly(2-Vinyl Pyridine)-b-Poly(n-Hexyl Isocyanate) Reversed Micelle Nanoreactor.

PubMed

Samal, Monica; Mohapatra, Priya Ranjan; Yun, Kyu Sik

2015-09-01

A diblock copolymer poly(2-vinyl pyridine)-b-poly(n-hexyl isocyanate) (P2VP-b-PHIC) is used for the present study. It has two blocks; a rod-shaped PHIC block that adopts a helical conformation, and a coil shaped P2VP block. In a polar solvent such as THF both PHIC and P2VP blocks are soluble. In mixtures of two solvents, such as THF and methanol, while the solubility of P2VP component is augmented that of PHIC is decreased leading to formation of reversed micelles. The pyridine nitrogen in P2VP block is a reactive site. It forms complexes with a suitable metal ion, such as Cd2+. The micelle is employed as a nanoreactor for synthesis of CdS quantum dot (QD). In this paper, the micellization behaviour of the copolymer and the use of the micelles for synthesis and controlled growth of CdS nanocrystals are demonstrated.

Biophotonic logic devices based on quantum dots and temporally-staggered Förster energy transfer relays

NASA Astrophysics Data System (ADS)

Claussen, Jonathan C.; Algar, W. Russ; Hildebrandt, Niko; Susumu, Kimihiro; Ancona, Mario G.; Medintz, Igor L.

2013-11-01

Integrating photonic inputs/outputs into unimolecular logic devices can provide significantly increased functional complexity and the ability to expand the repertoire of available operations. Here, we build upon a system previously utilized for biosensing to assemble and prototype several increasingly sophisticated biophotonic logic devices that function based upon multistep Förster resonance energy transfer (FRET) relays. The core system combines a central semiconductor quantum dot (QD) nanoplatform with a long-lifetime Tb complex FRET donor and a near-IR organic fluorophore acceptor; the latter acts as two unique inputs for the QD-based device. The Tb complex allows for a form of temporal memory by providing unique access to a time-delayed modality as an alternate output which significantly increases the inherent computing options. Altering the device by controlling the configuration parameters with biologically based self-assembly provides input control while monitoring changes in emission output of all participants, in both a spectral and temporal-dependent manner, gives rise to two input, single output Boolean Logic operations including OR, AND, INHIBIT, XOR, NOR, NAND, along with the possibility of gate transitions. Incorporation of an enzymatic cleavage step provides for a set-reset function that can be implemented repeatedly with the same building blocks and is demonstrated with single input, single output YES and NOT gates. Potential applications for these devices are discussed in the context of their constituent parts and the richness of available signal.

Biophotonic logic devices based on quantum dots and temporally-staggered Förster energy transfer relays.

PubMed

Claussen, Jonathan C; Algar, W Russ; Hildebrandt, Niko; Susumu, Kimihiro; Ancona, Mario G; Medintz, Igor L

2013-12-21

Integrating photonic inputs/outputs into unimolecular logic devices can provide significantly increased functional complexity and the ability to expand the repertoire of available operations. Here, we build upon a system previously utilized for biosensing to assemble and prototype several increasingly sophisticated biophotonic logic devices that function based upon multistep Förster resonance energy transfer (FRET) relays. The core system combines a central semiconductor quantum dot (QD) nanoplatform with a long-lifetime Tb complex FRET donor and a near-IR organic fluorophore acceptor; the latter acts as two unique inputs for the QD-based device. The Tb complex allows for a form of temporal memory by providing unique access to a time-delayed modality as an alternate output which significantly increases the inherent computing options. Altering the device by controlling the configuration parameters with biologically based self-assembly provides input control while monitoring changes in emission output of all participants, in both a spectral and temporal-dependent manner, gives rise to two input, single output Boolean Logic operations including OR, AND, INHIBIT, XOR, NOR, NAND, along with the possibility of gate transitions. Incorporation of an enzymatic cleavage step provides for a set-reset function that can be implemented repeatedly with the same building blocks and is demonstrated with single input, single output YES and NOT gates. Potential applications for these devices are discussed in the context of their constituent parts and the richness of available signal.

Selective directed self-assembly of coexisting morphologies using block copolymer blends

NASA Astrophysics Data System (ADS)

Stein, A.; Wright, G.; Yager, K. G.; Doerk, G. S.; Black, C. T.

2016-08-01

Directed self-assembly (DSA) of block copolymers is an emergent technique for nano-lithography, but is limited in the range of structures possible in a single fabrication step. Here we expand on traditional DSA chemical patterning. A blend of lamellar- and cylinder-forming block copolymers assembles on specially designed surface chemical line gratings, leading to the simultaneous formation of coexisting ordered morphologies in separate areas of the substrate. The competing energetics of polymer chain distortions and chemical mismatch with the substrate grating bias the system towards either line/space or dot array patterns, depending on the pitch and linewidth of the prepattern. This is in contrast to the typical DSA, wherein assembly of a single-component block copolymer on chemical templates generates patterns of either lines/spaces (lamellar) or hexagonal dot arrays (cylinders). In our approach, the chemical template encodes desired local spatial arrangements of coexisting design motifs, self-assembled from a single, sophisticated resist.

78 FR 27472 - Agency Information Collection Activities: Requests for Comments; Clearance of New Approval of...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-10

... Display to Industry (ASDI) Block Requests AGENCY: Federal Aviation Administration (FAA), DOT. ACTION... information will be used by the National Air Space Data Release Office to block aircraft flight data as... Display to Industry (ASDI) Block Requests. Form Numbers: There are no FAA forms associated with this...

Block QCA Fault-Tolerant Logic Gates

NASA Technical Reports Server (NTRS)

Firjany, Amir; Toomarian, Nikzad; Modarres, Katayoon

2003-01-01

Suitably patterned arrays (blocks) of quantum-dot cellular automata (QCA) have been proposed as fault-tolerant universal logic gates. These block QCA gates could be used to realize the potential of QCA for further miniaturization, reduction of power consumption, increase in switching speed, and increased degree of integration of very-large-scale integrated (VLSI) electronic circuits. The limitations of conventional VLSI circuitry, the basic principle of operation of QCA, and the potential advantages of QCA-based VLSI circuitry were described in several NASA Tech Briefs articles, namely Implementing Permutation Matrices by Use of Quantum Dots (NPO-20801), Vol. 25, No. 10 (October 2001), page 42; Compact Interconnection Networks Based on Quantum Dots (NPO-20855) Vol. 27, No. 1 (January 2003), page 32; Bit-Serial Adder Based on Quantum Dots (NPO-20869), Vol. 27, No. 1 (January 2003), page 35; and Hybrid VLSI/QCA Architecture for Computing FFTs (NPO-20923), which follows this article. To recapitulate the principle of operation (greatly oversimplified because of the limitation on space available for this article): A quantum-dot cellular automata contains four quantum dots positioned at or between the corners of a square cell. The cell contains two extra mobile electrons that can tunnel (in the quantummechanical sense) between neighboring dots within the cell. The Coulomb repulsion between the two electrons tends to make them occupy antipodal dots in the cell. For an isolated cell, there are two energetically equivalent arrangements (denoted polarization states) of the extra electrons. The cell polarization is used to encode binary information. Because the polarization of a nonisolated cell depends on Coulomb-repulsion interactions with neighboring cells, universal logic gates and binary wires could be constructed, in principle, by arraying QCA of suitable design in suitable patterns. Heretofore, researchers have recognized two major obstacles to realization of QCA-based logic gates: One is the need for (and the difficulty of attaining) operation of QCA circuitry at room temperature or, for that matter, at any temperature above a few Kelvins. It has been theorized that room-temperature operation could be made possible by constructing QCA as molecular-scale devices. However, in approaching the lower limit of miniaturization at the molecular level, it becomes increasingly imperative to overcome the second major obstacle, which is the need for (and the difficulty of attaining) high precision in the alignments of adjacent QCA in order to ensure the correct interactions among the quantum dots.

A Quick Assessment of Visuospatial Abilities in Adolescents Using the Design Organization Test (DOT).

PubMed

Burggraaf, Rudolf; Frens, Maarten A; Hooge, Ignace T C; van der Geest, Jos N

2016-01-01

Tests measuring visuospatial abilities have shown that these abilities increase during adolescence. Unfortunately, the Block Design test and other such tests are complicated and time-consuming to administer, making them unsuitable for use with large groups of restless adolescents. The results of the Design Organization Test (DOT), a quick pen-and-paper test, have been shown to correlate with those of the Block Design test. A group of 198 healthy adolescents (110 male and 88 female) aged 12 to 19 years old participated in this study. A slightly modified version of the DOT has been used in which we shortened the administration time to avoid a ceiling effect in the score. Scores show a linear increase with age (on average 2.0 points per year, r = .61) independent of sex. Scores did not differ between individual setting and group setting. Thus, the DOT is a simple and effective way to assess visuospatial ability in large groups, such as in schools, and it can be easily administered year after year to follow the development of students.

77 FR 34846 - Inspection, Repair, and Maintenance; Driver-Vehicle Inspection Report for Intermodal Equipment

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-12

... the IME. This responds to a joint petition for rulemaking from the Ocean Carrier Equipment Management... Management Facility, Room W12-140, DOT Building, 1200 New Jersey Avenue SE., Washington, DC. You may view the... Transportation's (DOT) Privacy Act system of records notice for the DOT Federal Docket Management System (FDMS...

Realization of solid-state nanothermometer using Ge quantum-dot single-hole transistor in few-hole regime

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, I. H.; Lai, W. T.; Li, P. W., E-mail: pwli@ee.ncu.edu.tw

2014-06-16

Semiconductor Ge quantum-dot (QD) thermometry has been demonstrated based on extraordinary temperature-dependent oscillatory differential conductance (G{sub D}) characteristics of Ge-QD single-hole transistors (SHTs) in the few-hole regime. Full-voltage width-at-half-minimum, V{sub 1/2}, of G{sub D} valleys appears to be fairly linear in the charge number (n) and temperature within the QD in a relationship of eV{sub 1/2} ≅ (1 − 0.11n) × 5.15k{sub B}T, providing the primary thermometric quantity. The depth of G{sub D} valley is also proportional to charging energy (E{sub C}) and 1/T via ΔG{sub D} ≅ E{sub C}/9.18k{sub B}T, providing another thermometric quantity. This experimental demonstration suggests our Ge-QD SHT offering effective building blocks for nanothermometersmore » over a wide temperature range with a detection temperature as high as 155 K in a spatial resolution less than 10 nm and temperature accuracy of sub-kelvin.« less

Plasmon-Assisted Selective and Super-Resolving Excitation of Individual Quantum Emitters on a Metal Nanowire.

PubMed

Li, Qiang; Pan, Deng; Wei, Hong; Xu, Hongxing

2018-03-14

Hybrid systems composed of multiple quantum emitters coupled with plasmonic waveguides are promising building blocks for future integrated quantum nanophotonic circuits. The techniques that can super-resolve and selectively excite contiguous quantum emitters in a diffraction-limited area are of great importance for studying the plasmon-mediated interaction between quantum emitters and manipulating the single plasmon generation and propagation in plasmonic circuits. Here we show that multiple quantum dots coupled with a silver nanowire can be controllably excited by tuning the interference field of surface plasmons on the nanowire. Because of the period of the interference pattern is much smaller than the diffraction limit, we demonstrate the selective excitation of two quantum dots separated by a distance as short as 100 nm. We also numerically demonstrate a new kind of super-resolution imaging method that combines the tunable surface plasmon interference pattern on the NW with the structured illumination microscopy technique. Our work provides a novel high-resolution optical excitation and imaging method for the coupled systems of multiple quantum emitters and plasmonic waveguides, which adds a new tool for studying and manipulating single quantum emitters and single plasmons for quantum plasmonic circuitry applications.

Electron Spin Optical Orientation in Charged Quantum Dots

NASA Astrophysics Data System (ADS)

Shabaev, A.; Gershoni, D.; Korenev, V. L.

2005-03-01

We present a theory of nonresonant optical orientation of electron spins localized in quantum dots. This theory explains the negative circularly polarized photoluminescence of singlet trions localized in quantum dots previously observed in experiments where trion polarization changed to negative with time and where the degree of the negative polarization increased with intensity of pumping light. We have shown that this effect can be explained by the accumulation of dark excitons that occurs due to the spin blocking of the singlet trion formation - the major mechanism of dark exciton recombination. The accumulation of dark excitons results from a lack of electrons with a spin matching the exciton polarization. The electron spin lifetime is shortened by a transverse magnetic field or a temperature increase. This takes the block off the dark exciton recombination and restores the positive degree of trion polarization. The presented theory gives good agreement with experimental data.

Negative differential conductance in InAs wire based double quantum dot induced by a charged AFM tip

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhukov, A. A., E-mail: azhukov@issp.ac.ru; Volk, Ch.; Winden, A.

We investigate the conductance of an InAs nanowire in the nonlinear regime in the case of low electron density where the wire is split into quantum dots connected in series. The negative differential conductance in the wire is initiated by means of a charged atomic force microscope tip adjusting the transparency of the tunneling barrier between two adjoining quantum dots. We confirm that the negative differential conductance arises due to the resonant tunneling between these two adjoining quantum dots. The influence of the transparency of the blocking barriers and the relative position of energy states in the adjoining dots onmore » a decrease of the negative differential conductance is investigated in detail.« less

Wavelength-tunable entangled photons from silicon-integrated III-V quantum dots.

PubMed

Chen, Yan; Zhang, Jiaxiang; Zopf, Michael; Jung, Kyubong; Zhang, Yang; Keil, Robert; Ding, Fei; Schmidt, Oliver G

2016-01-27

Many of the quantum information applications rely on indistinguishable sources of polarization-entangled photons. Semiconductor quantum dots are among the leading candidates for a deterministic entangled photon source; however, due to their random growth nature, it is impossible to find different quantum dots emitting entangled photons with identical wavelengths. The wavelength tunability has therefore become a fundamental requirement for a number of envisioned applications, for example, nesting different dots via the entanglement swapping and interfacing dots with cavities/atoms. Here we report the generation of wavelength-tunable entangled photons from on-chip integrated InAs/GaAs quantum dots. With a novel anisotropic strain engineering technique based on PMN-PT/silicon micro-electromechanical system, we can recover the quantum dot electronic symmetry at different exciton emission wavelengths. Together with a footprint of several hundred microns, our device facilitates the scalable integration of indistinguishable entangled photon sources on-chip, and therefore removes a major stumbling block to the quantum-dot-based solid-state quantum information platforms.

2D/0D graphene hybrids for visible-blind flexible UV photodetectors.

PubMed

Tetsuka, Hiroyuki

2017-07-17

Nitrogen-functionalized graphene quantum dots (NGQDs) are attractive building blocks for optoelectronic devices because of their exceptional tunable optical absorption and fluorescence properties. Here, we developed a high-performance flexible NGQD/graphene field-effect transistor (NGQD@GFET) hybrid ultraviolet (UV) photodetector, using dimethylamine-functionalized GQDs (NMe 2 -GQDs) with a large bandgap of ca. 3.3 eV. The NMe 2 -GQD@GFET photodetector exhibits high photoresponsivity and detectivity of ca. 1.5 × 10 4  A W -1 and ca. 5.5 × 10 11 Jones, respectively, in the deep-UV region as short as 255 nm without application of a backgate voltage. The feasibility of these flexible UV photodetectors for practical application in flame alarms is also demonstrated.

Selective directed self-assembly of coexisting morphologies using block copolymer blends

PubMed Central

Stein, A.; Wright, G.; Yager, K. G.; Doerk, G. S.; Black, C. T.

2016-01-01

Directed self-assembly (DSA) of block copolymers is an emergent technique for nano-lithography, but is limited in the range of structures possible in a single fabrication step. Here we expand on traditional DSA chemical patterning. A blend of lamellar- and cylinder-forming block copolymers assembles on specially designed surface chemical line gratings, leading to the simultaneous formation of coexisting ordered morphologies in separate areas of the substrate. The competing energetics of polymer chain distortions and chemical mismatch with the substrate grating bias the system towards either line/space or dot array patterns, depending on the pitch and linewidth of the prepattern. This is in contrast to the typical DSA, wherein assembly of a single-component block copolymer on chemical templates generates patterns of either lines/spaces (lamellar) or hexagonal dot arrays (cylinders). In our approach, the chemical template encodes desired local spatial arrangements of coexisting design motifs, self-assembled from a single, sophisticated resist. PMID:27480327

Selective directed self-assembly of coexisting morphologies using block copolymer blends

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stein, A.; Wright, G.; Yager, K. G.

Directed self-assembly (DSA) of block copolymers is an emergent technique for nano-lithography, but is limited in the range of structures possible in a single fabrication step. We expand on traditional DSA chemical patterning. Moreover, a blend of lamellar- and cylinder-forming block copolymers assembles on specially designed surface chemical line gratings, leading to the simultaneous formation of coexisting ordered morphologies in separate areas of the substrate. The competing energetics of polymer chain distortions and chemical mismatch with the substrate grating bias the system towards either line/space or dot array patterns, depending on the pitch and linewidth of the prepattern. This contrastsmore » with typical DSA, wherein assembly of a single-component block copolymer on chemical templates generates patterns of either lines/spaces (lamellar) or hexagonal dot arrays (cylinders). In our approach, the chemical template encodes desired local spatial arrangements of coexisting design motifs, self-assembled from a single, sophisticated resist.« less

Selective directed self-assembly of coexisting morphologies using block copolymer blends

DOE PAGES

Stein, A.; Wright, G.; Yager, K. G.; ...

2016-08-02

Directed self-assembly (DSA) of block copolymers is an emergent technique for nano-lithography, but is limited in the range of structures possible in a single fabrication step. We expand on traditional DSA chemical patterning. Moreover, a blend of lamellar- and cylinder-forming block copolymers assembles on specially designed surface chemical line gratings, leading to the simultaneous formation of coexisting ordered morphologies in separate areas of the substrate. The competing energetics of polymer chain distortions and chemical mismatch with the substrate grating bias the system towards either line/space or dot array patterns, depending on the pitch and linewidth of the prepattern. This contrastsmore » with typical DSA, wherein assembly of a single-component block copolymer on chemical templates generates patterns of either lines/spaces (lamellar) or hexagonal dot arrays (cylinders). In our approach, the chemical template encodes desired local spatial arrangements of coexisting design motifs, self-assembled from a single, sophisticated resist.« less

Rethinking I-94: Minnesota DOT: A TPCB Peer Exchange

DOT National Transportation Integrated Search

2017-12-01

This report highlights key recommendations and noteworthy practices identified at Rethinking I-94: MnDOT Peer Exchange held on August 15-16, 2017 in St. Paul, Minnesota. This event was sponsored by the Transportation Planning Capacity Building ...

78 FR 46546 - Design-Build Contracting

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-01

...-0043] RIN 2125-AF58 Design-Build Contracting AGENCY: Federal Highway Administration (FHWA), DOT. ACTION... alternative technical concepts (ATC) in design-build project delivery of highway construction. The revisions... design-build proposers to submit ATCs in their technical and price proposals. The FHWA seeks comments on...

The One-Pot Directed Assembly of Cylinder-Forming Block Copolymer on Adjacent Chemical Patterns for Bimodal Patterning.

PubMed

Chang, Tzu-Hsuan; Xiong, Shisheng; Liu, Chi-Chun; Liu, Dong; Nealey, Paul F; Ma, Zhenqiang

2017-09-01

The direct self-assembly of cylinder-forming poly(styrene-block-methyl-methacrylate) (PS-b-PMMA) block copolymer is successfully assembled into two orientations, according to the underlying guiding pattern in different areas. Lying-down and perpendicular cylinders are formed, respectively, depending on the design of chemical pattern: sparse line/space pattern or hexagonal dot array. The first chemical pattern composed of prepatterned cross-linked polystyrene (XPS) line/space structure has a period (L S ) equal to twice the intercylinder period of the block copolymer (L 0 ). The PS-b-PMMA thin film on the prepared chemical template after thermal annealing forms a lying-down cylinder morphology when the width of the PS strips is less than the width of PS block in the PS-b-PMMA block copolymer. The morphology is only applicable at the discrete thickness of the PS-b-PMMA film. In addition to forming the lying-down cylinders directly on the XPS guiding pattern, the cylinder-forming block copolymer can also be assembled in a perpendicular way on the second guiding pattern (the hexagonal dot array). The block copolymer films are registered into two orientations in a single directed self-assembly process. The features of the assembled patterns are successfully transferred down to the silicon oxide substrate. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

SRA Real Math Building Blocks PreK. What Works Clearinghouse Intervention Report

ERIC Educational Resources Information Center

What Works Clearinghouse, 2007

2007-01-01

"SRA Real Math Building Blocks PreK" (also referred to as "Building Blocks for Math") is a supplemental mathematics curriculum designed to develop preschool children's early mathematical knowledge through various individual and small- and large-group activities. It uses "Building Blocks for Math PreK" software,…

Role for the Silencing Protein Dot1 in Meiotic Checkpoint Control

PubMed Central

San-Segundo, Pedro A.; Roeder, G. Shirleen

2000-01-01

During the meiotic cell cycle, a surveillance mechanism called the “pachytene checkpoint” ensures proper chromosome segregation by preventing meiotic progression when recombination and chromosome synapsis are defective. The silencing protein Dot1 (also known as Pch1) is required for checkpoint-mediated pachytene arrest of the zip1 and dmc1 mutants of Saccharomyces cerevisiae. In the absence of DOT1, the zip1 and dmc1 mutants inappropriately progress through meiosis, generating inviable meiotic products. Other components of the pachytene checkpoint include the nucleolar protein Pch2 and the heterochromatin component Sir2. In dot1, disruption of the checkpoint correlates with the loss of concentration of Pch2 and Sir2 in the nucleolus. In addition to its checkpoint function, Dot1 blocks the repair of meiotic double-strand breaks by a Rad54-dependent pathway of recombination between sister chromatids. In vegetative cells, mutation of DOT1 results in delocalization of Sir3 from telomeres, accounting for the impaired telomeric silencing in dot1. PMID:11029058

Partnering for transportation safety : human-centered systems : operator fatigue management conference

DOT National Transportation Integrated Search

2000-01-01

This Conference was intended to enlist support for, and participation in, a new multi-modal DOT safety initiative. This initiative builds on the modal agency programs within DOT to develop techniques that transportation operating companies can employ...

Digital Alchemy for Materials Design: Colloids and Beyond

NASA Astrophysics Data System (ADS)

van Anders, Greg; Klotsa, Daphne; Karas, Andrew; Dodd, Paul; Glotzer, Sharon

Starting with the early alchemists, a holy grail of science has been to make desired materials by manipulating basic building blocks. Building blocks that show promise for assembling new complex materials can be synthesized at the nanoscale with attributes that would astonish the ancient alchemists in their versatility. However, this versatility means that connecting building-block attributes to bulk structure is both necessary for rationally engineering materials and difficult because building block attributes can be altered in many ways. We show how to exploit the malleability of colloidal nanoparticle ``elements'' to quantitatively link building-block attributes to bulk structure through a statistical thermodynamic framework we term ``digital alchemy''. We use this framework to optimize building blocks for a given target structure and to determine which building-block attributes are most important to control for self-assembly, through a set of novel thermodynamic response functions. We thereby establish direct links between the attributes of colloidal building blocks and the bulk structures they form. Moreover, our results give concrete solutions to the more general conceptual challenge of optimizing emergent behaviors in nature and can be applied to other types of matter.

Gaussian curvature analysis allows for automatic block placement in multi-block hexahedral meshing.

PubMed

Ramme, Austin J; Shivanna, Kiran H; Magnotta, Vincent A; Grosland, Nicole M

2011-10-01

Musculoskeletal finite element analysis (FEA) has been essential to research in orthopaedic biomechanics. The generation of a volumetric mesh is often the most challenging step in a FEA. Hexahedral meshing tools that are based on a multi-block approach rely on the manual placement of building blocks for their mesh generation scheme. We hypothesise that Gaussian curvature analysis could be used to automatically develop a building block structure for multi-block hexahedral mesh generation. The Automated Building Block Algorithm incorporates principles from differential geometry, combinatorics, statistical analysis and computer science to automatically generate a building block structure to represent a given surface without prior information. We have applied this algorithm to 29 bones of varying geometries and successfully generated a usable mesh in all cases. This work represents a significant advancement in automating the definition of building blocks.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mauldin, J.K.; Kard, B.M.

Minimum retentions of disodium octaborate tetrahydrate (DOT) needed in slash pine, Pinus elliottii Engelm. variety elliottii, wood to provide maximum protection against 2 species of subterranean termites were determined in choice and no-choice laboratory tests. Efficacy criteria for DOT were greater or equal to 90% termite mortality and equal to or less than 5% loss in weight of treated wooden blocks. For termites fed only DOT-treated wood, 0.10 and 0.30% boric acid equivalent (BAE, percentage of boric acid based on dry weight of wood, assuming all boron is present as boric acid) protected wood from the eastern subterranean termite, Reticulitermesmore » flavipes (Kollar), and Formosan subterranean termite, Coptotermes formosanus Shiraki, respectively. When termites had a choice between treated or nontreated wooden blocks were not in contact with soil or exposed to rain, a BAE of 0.30% protected the wood from naturally occuring Reticulitermes sp. for 18 mo. In wooden structures under constant pressure from subterranean termites, concentrations greater than 0.54% BAE may be required to protect wood, especially against C. formosanus.« less

The design-build contracting methodology for transportation projects : a review of practice and evaluation for Connecticut applications.

DOT National Transportation Integrated Search

2010-06-10

Two primary contracting methods are used by most state transportation agencies to : design and build infrastructure: design-bid-build and design-build. The objective : of this study is to conduct a literature review to identify how ConnDOTs use of...

Water-Dispersible, Multifunctional, Magnetic, Luminescent Silica-Encapsulated Composite Nanotubes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sutter, E.; Wong, S.; Zhou, H.

2010-02-05

A multifunctional one-dimensional nanostructure incorporating both CdSe quantum dots (QDs) and Fe{sub 3}O{sub 4} nanoparticles (NPs) within a SiO{sub 2}-nanotube matrix is successfully synthesized based on the self-assembly of preformed functional NPs, allowing for control over the size and amount of NPs contained within the composite nanostructures. This specific nanostructure is distinctive because both the favorable photoluminescent and magnetic properties of QD and NP building blocks are incorporated and retained within the final silica-based composite, thus rendering it susceptible to both magnetic guidance and optical tracking. Moreover, the resulting hydrophilic nanocomposites are found to easily enter into the interiors ofmore » HeLa cells without damage, thereby highlighting their capability not only as fluorescent probes but also as possible drug-delivery vehicles of interest in nanobiotechnology.« less

Multi-shape memory polymers achieved by the spatio-assembly of 3D printable thermoplastic building blocks.

PubMed

Li, Hongze; Gao, Xiang; Luo, Yingwu

2016-04-07

Multi-shape memory polymers were prepared by the macroscale spatio-assembly of building blocks in this work. The building blocks were methyl acrylate-co-styrene (MA-co-St) copolymers, which have the St-block-(St-random-MA)-block-St tri-block chain sequence. This design ensures that their transition temperatures can be adjusted over a wide range by varying the composition of the middle block. The two St blocks at the chain ends can generate a crosslink network in the final device to achieve strong bonding force between building blocks and the shape memory capacity. Due to their thermoplastic properties, 3D printing was employed for the spatio-assembly to build devices. This method is capable of introducing many transition phases into one device and preparing complicated shapes via 3D printing. The device can perform a complex action via a series of shape changes. Besides, this method can avoid the difficult programing of a series of temporary shapes. The control of intermediate temporary shapes was realized via programing the shapes and locations of building blocks in the final device.

A novel power-efficient high-speed clock management unit using quantum-dot cellular automata

NASA Astrophysics Data System (ADS)

Abutaleb, M. M.

2017-04-01

Quantum-dot cellular automata (QCA) is one of the most attractive alternatives for complementary metal-oxide semiconductor technology. The QCA widely supports a new paradigm in the field of nanotechnology that has the potential for high density, low power, and high speed. The clock manager is an essential building block in the new microwave and radio frequency integrated circuits. This paper describes a novel QCA-based clock management unit (CMU) that provides innovative clocking capabilities. The proposed CMU is achieved by utilizing edge-triggered D-type flip-flops (D-FFs) in the design of frequency synthesizer and phase splitter. Edge-triggered D-FF structures proposed in this paper have the successful QCA implementation and simulation with the least complexity and power dissipation as compared to earlier structures. The frequency synthesizer is used to generate new clock frequencies from the reference clock frequency based on a combination of power-of-two frequency dividers. The phase splitter is integrated with the frequency synthesizer to generate four clock signals that are 90o out of phase with each other. This paper demonstrates that the proposed QCA CMU structure has a superior performance. Furthermore, the proposed CMU is straightforwardly scalable due to the use of modular component architecture.

Reliability Analysis and Standardization of Spacecraft Command Generation Processes

NASA Technical Reports Server (NTRS)

Meshkat, Leila; Grenander, Sven; Evensen, Ken

2011-01-01

center dot In order to reduce commanding errors that are caused by humans, we create an approach and corresponding artifacts for standardizing the command generation process and conducting risk management during the design and assurance of such processes. center dot The literature review conducted during the standardization process revealed that very few atomic level human activities are associated with even a broad set of missions. center dot Applicable human reliability metrics for performing these atomic level tasks are available. center dot The process for building a "Periodic Table" of Command and Control Functions as well as Probabilistic Risk Assessment (PRA) models is demonstrated. center dot The PRA models are executed using data from human reliability data banks. center dot The Periodic Table is related to the PRA models via Fault Links.

Data Policy Construction Set - Building Blocks from Childhood Constructions

NASA Astrophysics Data System (ADS)

Fleischer, Dirk; Paul-Stueve, Thilo; Jobmann, Alexandra; Farrenkopf, Stefan

2016-04-01

A complete construction set of building blocks usually comes with instructions and these instruction include building stages. The products of these building stages usually build from very general parts become highly specialized building parts for very unique features of the whole construction model. This sounds very much like the construction or organization of an interdisciplinary research project, institution or association, doesn't it! The creation process of an overarching data policy for a project group or institution is exactly the combination of individual interests with the common goal of a collaborative data policy and can be compared with the building stages of a construction set of building blocks and the building instructions. Keeping this in mind we created the data policy construction set of textual building blocks. This construction set is subdivided into several building stages or parts each containing multiple building blocks as text blocks. By combining building blocks of all subdivisions it is supposed to create a cascading data policy document. Cascading from the top level as a construction set provider for all further down existing levels such as project, themes, work packages or Universities, faculties, institutes down to the working level of working groups. The working groups are picking from the remaining building blocks in the provided construction set the suitable blocks for its working procedures to create a very specific policy from the available construction set provided by the top level community. Nevertheless, if a working group realized that there are missing building blocks or worse that there are missing building parts, then they have the chance to add the missing pieces to the construction set of direct an future use. This cascading approach enables project or institution wide application of the encoded rules from the textual level on access to data storage infrastructure. This structured approach is flexible enough to allow for the fact that interdisciplinary research projects always bring together very diverse amount of working habits, methods and requirements. All these need to be considered for the creation of the general document on data sharing and research data management. This approach focused on the recommendation of the RDA practical policy working group to implement practical policies derived from the textual level. Therefore it aims to move the data policy creation procedure and implementation towards the consortium or institutional formation with all the benefits of an existing data policy construction set already during the proposal creation and proposal review. Picking up the metaphor of real building blocks in context of data policies provides also the insight that existing building blocks and building parts can be reused as they are, but also can be redesigned with very little changes or a full overhaul.

I90/94 fiber backbone network and spurs build-out. Phase II

DOT National Transportation Integrated Search

2006-09-05

The Wisconsin Department of Transportation (WisDOT) received 36 strands of dark fiber located on I-94 right of way, running the entire length of the corridor in Wisconsin. This was the result of a right of way exchange WisDOT executed in 2000. Althou...

The Impact of Individual Differences, Types of Model and Social Settings on Block Building Performance among Chinese Preschoolers.

PubMed

Tian, Mi; Deng, Zhu; Meng, Zhaokun; Li, Rui; Zhang, Zhiyi; Qi, Wenhui; Wang, Rui; Yin, Tingting; Ji, Menghui

2018-01-01

Children's block building performances are used as indicators of other abilities in multiple domains. In the current study, we examined individual differences, types of model and social settings as influences on children's block building performance. Chinese preschoolers ( N = 180) participated in a block building activity in a natural setting, and performance was assessed with multiple measures in order to identify a range of specific skills. Using scores generated across these measures, three dependent variables were analyzed: block building skills, structural balance and structural features. An overall MANOVA showed that there were significant main effects of gender and grade level across most measures. Types of model showed no significant effect in children's block building. There was a significant main effect of social settings on structural features, with the best performance in the 5-member group, followed by individual and then the 10-member block building. These findings suggest that boys performed better than girls in block building activity. Block building performance increased significantly from 1st to 2nd year of preschool, but not from second to third. The preschoolers created more representational constructions when presented with a model made of wooden rather than with a picture. There was partial evidence that children performed better when working with peers in a small group than when working alone or working in a large group. It is suggested that future study should examine other modalities rather than the visual one, diversify the samples and adopt a longitudinal investigation.

Analog Building Blocks for Communications Modems.

DTIC Science & Technology

1977-01-01

x*—*- A0-A039 82b ELECTRONIC COMMUNICATIONS INC ST PETERSBURG FLA F/6 9/5 ANALOG BUILDING BLOCKS FOR COMMUNICATIONS MODEMS .(U) JAN 77 B BLACK...F33615-7<t-C-1120 UNCLASSIFIED AFAL-TR-76-29 NL ANALOG BUILDING BLOCKS FOR COMMUNICATIONS MODEMS ELECTRONIC COMMUNICATIONS INC. A SUBSIDIARY OF...Idantltr Or Mac* numb*,; Avionics Building-Block modules Frequency Synthesize* Costas Demodulator Amplifier Modem Frequency Multiplier ’ -^ « TRACT

Fault-tolerant computer study. [logic designs for building block circuits

NASA Technical Reports Server (NTRS)

Rennels, D. A.; Avizienis, A. A.; Ercegovac, M. D.

1981-01-01

A set of building block circuits is described which can be used with commercially available microprocessors and memories to implement fault tolerant distributed computer systems. Each building block circuit is intended for VLSI implementation as a single chip. Several building blocks and associated processor and memory chips form a self checking computer module with self contained input output and interfaces to redundant communications buses. Fault tolerance is achieved by connecting self checking computer modules into a redundant network in which backup buses and computer modules are provided to circumvent failures. The requirements and design methodology which led to the definition of the building block circuits are discussed.

Adolescent Boys' and Girls' Block Constructions Differ in Structural Balance: A Block-Building Characteristic Related to Math Achievement

ERIC Educational Resources Information Center

Casey, Beth M.; Pezaris, Elizabeth E.; Bassi, Julie

2012-01-01

Two studies were conducted on block building in adolescents, assessing middle school (Study 1) and high school students (Study 2). Students were asked to build something interesting with blocks. In both samples, the same pattern of gender differences were found; boys built taller structures than girls, and balanced a larger number of blocks on a…

Aerial Imagery and LIDAR Data Fusion for Unambiguous Extraction of Adjacent Level-Buildings Footprints

NASA Astrophysics Data System (ADS)

Mola Ebrahimi, S.; Arefi, H.; Rasti Veis, H.

2017-09-01

Our paper aims to present a new approach to identify and extract building footprints using aerial images and LiDAR data. Employing an edge detector algorithm, our method first extracts the outer boundary of buildings, and then by taking advantage of Hough transform and extracting the boundary of connected buildings in a building block, it extracts building footprints located in each block. The proposed method first recognizes the predominant leading orientation of a building block using Hough transform, and then rotates the block according to the inverted complement of the dominant line's angle. Therefore the block poses horizontally. Afterwards, by use of another Hough transform, vertical lines, which might be the building boundaries of interest, are extracted and the final building footprints within a block are obtained. The proposed algorithm is implemented and tested on the urban area of Zeebruges, Belgium(IEEE Contest,2015). The areas of extracted footprints are compared to the corresponding areas in the reference data and mean error is equal to 7.43 m2. Besides, qualitative and quantitative evaluations suggest that the proposed algorithm leads to acceptable results in automated precise extraction of building footprints.

Composition of clusters and building blocks in amylopectins from maize mutants deficient in starch synthase III.

PubMed

Zhu, Fan; Bertoft, Eric; Seetharaman, Koushik

2013-12-18

Branches in amylopectin are distributed along the backbone. Units of the branches are building blocks (smaller) and clusters (larger) based on the distance between branches. In this study, composition of clusters and building blocks of amylopectins from dull1 maize mutants deficient in starch synthase III (SSIII) with a common genetic background (W64A) were characterized and compared with the wild type. Clusters were produced from amylopectins by partial hydrolysis using α-amylase of Bacillus amyloliquefaciens and were subsequently treated with phosphorylase a and β-amylase to produce φ,β-limit dextrins. Clusters were further extensively hydrolyzed with the α-amylase to produce building blocks. Structures of clusters and building blocks were analyzed by diverse chromatographic techniques. The results showed that the dull1 mutation resulted in larger clusters with more singly branched building blocks. The average cluster contained ~5.4 blocks in dull1 mutants and ~4.2 blocks in the wild type. The results are compared with previous results from SSIII-deficient amo1 barley and suggest fundamental differences in the cluster structures.

Engineering the formation of secondary building blocks within hollow interiors.

PubMed

Li, Xiaobo; Liu, Xiao; Ma, Yi; Li, Mingrun; Zhao, Jiao; Xin, Hongchuan; Zhang, Lei; Yang, Yan; Li, Can; Yang, Qihua

2012-03-15

Secondary building blocks within the cavities of primary silica-architecture building blocks are successfully engineered. The immobilized surfactant directs the selective dissolution and reassembly of dissolved silicate species for the formation of secondary building blocks (hollow nanospheres/nanorods; see figure). Supported TiO(2) on nanostructures with multilevel interiors is shown to exhibit significantly enhanced activity in photocatalytic H(2) production. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

49 CFR 41.117 - Buildings built with Federal assistance.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 1 2010-10-01 2010-10-01 false Buildings built with Federal assistance. 41.117 Section 41.117 Transportation Office of the Secretary of Transportation SEISMIC SAFETY § 41.117 Buildings built with Federal assistance. (a) Each DOT Operating Administration assisting in the financing, through...

Collective fluorescence and decoherence of a few nearly identical quantum dots

NASA Astrophysics Data System (ADS)

Sitek, Anna; Machnikowski, Paweł

2007-01-01

We study the collective interaction of excitons in closely spaced artificial molecules and arrays of nearly identical quantum dots with the electromagnetic modes. We discuss how collective fluorescence builds up in the presence of a small mismatch of the transition energy. We show that a superradiant state of a single exciton in a molecule of two dots with realistic energy mismatch undergoes a two-rate decay. We also analyze the stability of subdecoherent states for nonidentical systems.

The Impact of Individual Differences, Types of Model and Social Settings on Block Building Performance among Chinese Preschoolers

PubMed Central

Tian, Mi; Deng, Zhu; Meng, Zhaokun; Li, Rui; Zhang, Zhiyi; Qi, Wenhui; Wang, Rui; Yin, Tingting; Ji, Menghui

2018-01-01

Children’s block building performances are used as indicators of other abilities in multiple domains. In the current study, we examined individual differences, types of model and social settings as influences on children’s block building performance. Chinese preschoolers (N = 180) participated in a block building activity in a natural setting, and performance was assessed with multiple measures in order to identify a range of specific skills. Using scores generated across these measures, three dependent variables were analyzed: block building skills, structural balance and structural features. An overall MANOVA showed that there were significant main effects of gender and grade level across most measures. Types of model showed no significant effect in children’s block building. There was a significant main effect of social settings on structural features, with the best performance in the 5-member group, followed by individual and then the 10-member block building. These findings suggest that boys performed better than girls in block building activity. Block building performance increased significantly from 1st to 2nd year of preschool, but not from second to third. The preschoolers created more representational constructions when presented with a model made of wooden rather than with a picture. There was partial evidence that children performed better when working with peers in a small group than when working alone or working in a large group. It is suggested that future study should examine other modalities rather than the visual one, diversify the samples and adopt a longitudinal investigation. PMID:29441031

Seebeck effect on a weak link between Fermi and non-Fermi liquids

NASA Astrophysics Data System (ADS)

Nguyen, T. K. T.; Kiselev, M. N.

2018-02-01

We propose a model describing Seebeck effect on a weak link between two quantum systems with fine-tunable ground states of Fermi and non-Fermi liquid origin. The experimental realization of the model can be achieved by utilizing the quantum devices operating in the integer quantum Hall regime [Z. Iftikhar et al., Nature (London) 526, 233 (2015), 10.1038/nature15384] designed for detection of macroscopic quantum charged states in multichannel Kondo systems. We present a theory of thermoelectric transport through hybrid quantum devices constructed from quantum-dot-quantum-point-contact building blocks. We discuss pronounced effects in the temperature and gate voltage dependence of thermoelectric power associated with a competition between Fermi and non-Fermi liquid behaviors. High controllability of the device allows to fine tune the system to different regimes described by multichannel and multi-impurity Kondo models.

Infrared retina

DOEpatents

Krishna, Sanjay [Albuquerque, NM; Hayat, Majeed M [Albuquerque, NM; Tyo, J Scott [Tucson, AZ; Jang, Woo-Yong [Albuquerque, NM

2011-12-06

Exemplary embodiments provide an infrared (IR) retinal system and method for making and using the IR retinal system. The IR retinal system can include adaptive sensor elements, whose properties including, e.g., spectral response, signal-to-noise ratio, polarization, or amplitude can be tailored at pixel level by changing the applied bias voltage across the detector. "Color" imagery can be obtained from the IR retinal system by using a single focal plane array. The IR sensor elements can be spectrally, spatially and temporally adaptive using quantum-confined transitions in nanoscale quantum dots. The IR sensor elements can be used as building blocks of an infrared retina, similar to cones of human retina, and can be designed to work in the long-wave infrared portion of the electromagnetic spectrum ranging from about 8 .mu.m to about 12 .mu.m as well as the mid-wave portion ranging from about 3 .mu.m to about 5 .mu.m.

Using the World Health Organization health system building blocks through survey of healthcare professionals to determine the performance of public healthcare facilities.

PubMed

Manyazewal, Tsegahun

2017-01-01

Acknowledging the health system strengthening agenda, the World Health Organization (WHO) has formulated a health systems framework that describes health systems in terms of six building blocks. This study aimed to determine the current status of the six WHO health system building blocks in public healthcare facilities in Ethiopia. A quantitative, cross-sectional study was conducted in five public hospitals in central Ethiopia which were in a post-reform period. A self-administered, structured questionnaire which covered the WHO's six health system building blocks was used to collect data on healthcare professionals who consented. Data was analyzed using IBM SPSS version 20. The overall performance of the public hospitals was 60% when weighed against the WHO building blocks which, in this procedure, needed a minimum of 80% score. For each building block, performance scores were: information 53%, health workforce 55%, medical products and technologies 58%, leadership and governance 61%, healthcare financing 62%, and service delivery 69%. There existed a significant difference in performance among the hospitals ( p  < .001). The study proved that the WHO's health system building blocks are useful for assessing the process of strengthening health systems in Ethiopia. The six blocks allow identifying different improvement opportunities in each one of the hospitals. There was no contradiction between the indicators of the WHO building blocks and the health sustainable development goal (SDG) objectives. However, such SDG objectives should not be a substitute for strategies to strengthen health systems.

NANOSTRUCTURED METAL OXIDE CATALYSTS VIA BUILDING BLOCK SYNTHESES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Craig E. Barnes

2013-03-05

A broadly applicable methodology has been developed to prepare new single site catalysts on silica supports. This methodology requires of three critical components: a rigid building block that will be the main structural and compositional component of the support matrix; a family of linking reagents that will be used to insert active metals into the matrix as well as cross link building blocks into a three dimensional matrix; and a clean coupling reaction that will connect building blocks and linking agents together in a controlled fashion. The final piece of conceptual strategy at the center of this methodology involves dosingmore » the building block with known amounts of linking agents so that the targeted connectivity of a linking center to surrounding building blocks is obtained. Achieving targeted connectivities around catalytically active metals in these building block matrices is a critical element of the strategy by which single site catalysts are obtained. This methodology has been demonstrated with a model system involving only silicon and then with two metal-containing systems (titanium and vanadium). The effect that connectivity has on the reactivity of atomically dispersed titanium sites in silica building block matrices has been investigated in the selective oxidation of phenols to benezoquinones. 2-connected titanium sites are found to be five times as active (i.e. initial turnover frequencies) than 4-connected titanium sites (i.e. framework titanium sites).« less

The Building Blocks of Geology.

ERIC Educational Resources Information Center

Gibson, Betty O.

2001-01-01

Discusses teaching techniques for teaching about rocks, minerals, and the differences between them. Presents a model-building activity that uses plastic building blocks to build crystal and rock models. (YDS)

Colloidal PbS nanocrystals integrated to Si-based photonics for applications at telecom wavelengths

NASA Astrophysics Data System (ADS)

Humer, M.; Guider, R.; Jantsch, W.; Fromherz, T.

2013-05-01

In the last decade, Si based photonics has made major advances in terms of design, fabrication, and device implementation. But due to Silicon's indirect bandgap, it still remains a challenge to create efficient Si-based light emitting devices. In order to overcome this problem, an approach is to develop hybrid systems integrating light-emitting materials into Si. A promising class of materials for this purpose is the class of semiconducting nanocrystal quantum dots (NCs) that are synthesized by colloidal chemistry. As their absorption and emission wavelength depends on the dot size, which can easily be controlled during synthesis, they are extremely attractive as building blocks for nanophotonic applications. For applications in telecom wavelength, Lead chalcogenide colloidal NCs are optimum materials due to their unique optical, electronic and nonlinear properties. In this work, we experimentally demonstrate the integration of PbS nanocrystals into Si-based photonic structures like slot waveguides and ring resonators as optically pumped emitters for room temperature applications. In order to create such hybrid structures, the NCs were dissolved into polymer resists and drop cast on top of the device. Upon optical pumping, intense photoluminescence emission from the resonating modes is recorded at the output of the waveguide with transmission quality factors up to 14000. The polymer host material was investigated with respect to its ability to stabilize the NC's photoluminescence emission against degradation under ambient conditions. The waveguide-ring coupling efficiency was also investigated as function of the NCs concentrations blended into the polymer matrix. The integration of colloidal quantum dots into Silicon photonic structures as demonstrated in this work is a very versatile technique and thus opens a large range of applications utilizing the linear and nonlinear optical properties of PbS NCs at telecom wavelengths.

Experimental Demonstration of Photon Efficient Coherent Temporal Combining for Data Rate Scaling

DTIC Science & Technology

2016-02-15

combining with pre-amplified Distribution A: Public Release. This work was sponsored by the Assistant Secretary of Defense for Research and Engineering...for -96 dBm signal with 211-1 points after block repeating and combining the waveform various number of block repeats (N). The blue dots and red...particular, Figure 5 shows constellation diagrams for the -96 dBm signal after temporal coherent combining of 4,000, 8,000, 16,000, 32,000, and 36,000 block

Functionalized Helical Building Blocks for Nanoelectronics.

PubMed

Khokhlov, Khrystofor; Schuster, Nathaniel J; Ng, Fay; Nuckolls, Colin

2018-04-06

Molecular building blocks are designed and created for the cis- and trans-dibrominated perylenediimides. The syntheses are simple and provide these useful materials on the gram scale. To demonstrate their synthetic versatility, these building blocks were used to create new dimeric perylenediimide helixes. Two of these helical dimers are twistacenes, and one is a helicene. Crucially, each possesses regiochemically defined functionality that allows the dimer helix to be elaborated into higher oligomers. It would be very difficult to prepare these helical PDI building blocks regioselectively without the methods described.

Determining the applicability of the Landauer nanoDot as a general public dosimeter in a research imaging facility.

PubMed

Charlton, Michael A; Thoreson, Kelly F; Cerecero, Jennifer A

2012-11-01

The Research Imaging Institute (RII) building at the University of Texas Health Science Center at San Antonio (UTHSCSA) houses two cyclotron particle accelerators, positron emission tomography (PET) machines, and a fluoroscopic unit. As part of the radiation protection program (RPP) and meeting the standard for achieving ALARA (as low as reasonably achievable), it is essential to minimize the ionizing radiation exposure to the general public through the use of controlled areas and area dose monitoring. Currently, thirty-four whole body Luxel+ dosimeters, manufactured by Landauer, are being used in various locations within the RII to monitor dose to the general public. The intent of this research was to determine if the nanoDot, a single point dosimeter, can be used as a general public dosimeter in a diagnostic facility. This was tested by first verifying characteristics of the nanoDot dosimeter including dose linearity, dose rate dependence, angular dependence, and energy dependence. Then, the response of the nanoDot dosimeter to the Luxel+ dosimeter when placed in a continuous, low dose environment was investigated. Finally, the nanoDot was checked for appropriate response in an acute, high dose environment. Based on the results, the current recommendation is that the nanoDot should not replace the Luxel+ dosimeter without further work to determine the energy spectra in the RII building and without considering the limitation of the microStar reader, portable on-site OSL reader, at doses below 0.1 mGy (10 mrad).

The 10 building blocks of high-performing primary care.

PubMed

Bodenheimer, Thomas; Ghorob, Amireh; Willard-Grace, Rachel; Grumbach, Kevin

2014-01-01

Our experiences studying exemplar primary care practices, and our work assisting other practices to become more patient centered, led to a formulation of the essential elements of primary care, which we call the 10 building blocks of high-performing primary care. The building blocks include 4 foundational elements-engaged leadership, data-driven improvement, empanelment, and team-based care-that assist the implementation of the other 6 building blocks-patient-team partnership, population management, continuity of care, prompt access to care, comprehensiveness and care coordination, and a template of the future. The building blocks, which represent a synthesis of the innovative thinking that is transforming primary care in the United States, are both a description of existing high-performing practices and a model for improvement.

Two innovative solutions based on fibre concrete blocks designed for building substructure

NASA Astrophysics Data System (ADS)

Pazderka, J.; Hájek, P.

2017-09-01

Using of fibers in a high-strength concrete allows reduction of the dimensions of small precast concrete elements, which opens up new ways of solution for traditional construction details in buildings. The paper presents two innovative technical solutions for building substructure: The special shaped plinth block from fibre concrete and the fibre concrete elements for new technical solution of ventilated floor. The main advantages of plinth block from fibre concrete blocks (compared with standard plinth solutions) is: easier and faster assembly, higher durability and thanks to the air cavity between the vertical part of the block, the building substructure reduced moisture level of structures under the waterproofing layer and a comprehensive solution to the final surface of building plinth as well as the surface of adjacent terrain. The ventilated floor based on fibre concrete precast blocks is an attractive structural alternative for tackling the problem of increased moisture in masonry in older buildings, lacking a functional waterproof layer in the substructure.

Development of Test Article Building Block (TABB) for deployable platform systems

NASA Technical Reports Server (NTRS)

Greenberg, H. S.; Barbour, R. T.

1984-01-01

The concept of a Test Article Building Block (TABB) is described. The TABB is a ground test article that is representative of a future building block that can be used to construct LEO and GEO deployable space platforms for communications and scientific payloads. This building block contains a main housing within which the entire structure, utilities, and deployment/retraction mechanism are stowed during launch. The end adapter secures the foregoing components to the housing during launch. The main housing and adapter provide the necessary building-block-to-building-block attachments for automatically deployable platforms. Removal from the shuttle cargo bay can be accomplished with the remote manipulator system (RMS) and/or the handling and positioning aid (HAPA). In this concept, all the electrical connections are in place prior to launch with automatic latches for payload attachment provided on either the end adapters or housings. The housings also can contain orbiter docking ports for payload installation and maintenance.

Efficient Risk Determination of Risk of Road Blocking by Means of MMS and Data of Buildings and Their Surrounding

NASA Astrophysics Data System (ADS)

Nose, Kazuhito; Hatake, Shuhei

2016-06-01

Massive earthquake named "Tonankai Massive earthquake" is predicted to occur in the near future and is feared to cause severe damage in Kinki District . "Hanshin-Awaji Massive Earthquake" in 1995 destroyed most of the buildings constructed before 1981 and not complying with the latest earthquake resistance standards. Collapsed buildings blocked roads, obstructed evacuation, rescue and firefighting operations and inflicted further damages.To alleviate the damages, it is important to predict the points where collapsed buildings are likely block the roads and to take precautions in advance. But big cities have an expanse of urban areas with densely-distributed buildings, and it requires time and cost to check each and every building whether or not it will block the road. In order to reduce blocked roads when a disaster strikes, we made a study and confirmed that the risk of road blocking can be determined easily by means of the latest technologies of survey and geographical information.

In sílico identification and characterization of putative Dot/Icm secreted virulence effectors in the fish pathogen Piscirickettsia salmonis.

PubMed

Labra, Álvaro; Arredondo-Zelada, Oscar; Flores-Herrera, Patricio; Marshall, Sergio H; Gómez, Fernando A

2016-03-01

Piscirickettsia salmonis seriously affects the Chilean salmon industry. The bacterium is phylogenetically related to Legionella pneumophila and Coxiella burnetii, sharing a Dot/Icm secretion system with them. Although it is well documented that L. pneumophila and C. burnetii secrete different virulence effectors via this Dot/Icm system in order to attenuate host cell responses, to date there have been no reported virulence effectors secreted by the Dot/Icm system of P. salmonis. Using several annotations of P. salmonis genome, here we report an in silico analyses of 4 putative Dot/Icm effectors. Three of them contain ankyrin repeat domains and the typical conserved 3D structures of this protein family. The fourth one is highly similar to one of the Dot/Icm-dependent effectors of L. pneumophila. Additionally, all the potential P. salmonis effectors contain a classical Dot/Icm secretion signal in their C-terminus, consisting of: an E-Block, a hydrophobic residue in -3 or -4 and an electronegative charge. Finally, qPCR analysis demonstrated that these proteins are overexpressed early in infection, perhaps contributing to the generation of a replicative vacuole, a key step in the neutralizing strategy proposed for the Dot/Icm system. In summary, this report identifies four Dot/Icm-dependent effectors in P. salmonis. Copyright © 2015 Elsevier Ltd. All rights reserved.

Autonomous quantum Maxwell's demon based on two exchange-coupled quantum dots

NASA Astrophysics Data System (ADS)

Ptaszyński, Krzysztof

2018-01-01

I study an autonomous quantum Maxwell's demon based on two exchange-coupled quantum dots attached to the spin-polarized leads. The principle of operation of the demon is based on the coherent oscillations between the spin states of the system which act as a quantum iSWAP gate. Due to the operation of the iSWAP gate, one of the dots acts as a feedback controller which blocks the transport with the bias in the other dot, thus inducing the electron pumping against the bias; this leads to the locally negative entropy production. Operation of the demon is associated with the information transfer between the dots, which is studied quantitatively by mapping the analyzed setup onto the thermodynamically equivalent auxiliary system. The calculated entropy production in a single subsystem and information flow between the subsystems are shown to obey a local form of the second law of thermodynamics, similar to the one previously derived for classical bipartite systems.

Towards zero-threshold optical gain using charged semiconductor quantum dots

DOE PAGES

Wu, Kaifeng; Park, Young -Shin; Lim, Jaehoon; ...

2017-10-16

Colloidal semiconductor quantum dots are attractive materials for the realization of solution-processable lasers. However, their applications as optical-gain media are complicated by a non-unity degeneracy of band-edge states, because of which multiexcitons are required to achieve the lasing regime. This increases the lasing thresholds and leads to very short optical gain lifetimes limited by nonradiative Auger recombination. Here, we show that these problems can be at least partially resolved by employing not neutral but negatively charged quantum dots. By applying photodoping to specially engineered quantum dots with impeded Auger decay, we demonstrate a considerable reduction of the optical gain thresholdmore » due to suppression of ground-state absorption by pre-existing carriers. Moreover, by injecting approximately one electron per dot on average, we achieve a more than twofold reduction in the amplified spontaneous emission threshold, bringing it to the sub-single-exciton level. Furthermore, these measurements indicate the feasibility of ‘zero-threshold’ gain achievable by completely blocking the band-edge state with two electrons.« less

Towards zero-threshold optical gain using charged semiconductor quantum dots

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, Kaifeng; Park, Young -Shin; Lim, Jaehoon

Colloidal semiconductor quantum dots are attractive materials for the realization of solution-processable lasers. However, their applications as optical-gain media are complicated by a non-unity degeneracy of band-edge states, because of which multiexcitons are required to achieve the lasing regime. This increases the lasing thresholds and leads to very short optical gain lifetimes limited by nonradiative Auger recombination. Here, we show that these problems can be at least partially resolved by employing not neutral but negatively charged quantum dots. By applying photodoping to specially engineered quantum dots with impeded Auger decay, we demonstrate a considerable reduction of the optical gain thresholdmore » due to suppression of ground-state absorption by pre-existing carriers. Moreover, by injecting approximately one electron per dot on average, we achieve a more than twofold reduction in the amplified spontaneous emission threshold, bringing it to the sub-single-exciton level. Furthermore, these measurements indicate the feasibility of ‘zero-threshold’ gain achievable by completely blocking the band-edge state with two electrons.« less

Bit-Serial Adder Based on Quantum Dots

NASA Technical Reports Server (NTRS)

Fijany, Amir; Toomarian, Nikzad; Modarress, Katayoon; Spotnitz, Mathew

2003-01-01

A proposed integrated circuit based on quantum-dot cellular automata (QCA) would function as a bit-serial adder. This circuit would serve as a prototype building block for demonstrating the feasibility of quantum-dots computing and for the further development of increasingly complex and increasingly capable quantum-dots computing circuits. QCA-based bit-serial adders would be especially useful in that they would enable the development of highly parallel and systolic processors for implementing fast Fourier, cosine, Hartley, and wavelet transforms. The proposed circuit would complement the QCA-based circuits described in "Implementing Permutation Matrices by Use of Quantum Dots" (NPO-20801), NASA Tech Briefs, Vol. 25, No. 10 (October 2001), page 42 and "Compact Interconnection Networks Based on Quantum Dots" (NPO-20855), which appears elsewhere in this issue. Those articles described the limitations of very-large-scale-integrated (VLSI) circuitry and the major potential advantage afforded by QCA. To recapitulate: In a VLSI circuit, signal paths that are required not to interact with each other must not cross in the same plane. In contrast, for reasons too complex to describe in the limited space available for this article, suitably designed and operated QCA-based signal paths that are required not to interact with each other can nevertheless be allowed to cross each other in the same plane without adverse effect. In principle, this characteristic could be exploited to design compact, coplanar, simple (relative to VLSI) QCA-based networks to implement complex, advanced interconnection schemes. To enable a meaningful description of the proposed bit-serial adder, it is necessary to further recapitulate the description of a quantum-dot cellular automation from the first-mentioned prior article: A quantum-dot cellular automaton contains four quantum dots positioned at the corners of a square cell. The cell contains two extra mobile electrons that can tunnel (in the quantum-mechanical sense) between neighboring dots within the cell. The Coulomb repulsion between the two electrons tends to make them occupy antipodal dots in the cell. For an isolated cell, there are two energetically equivalent arrangements (denoted polarization states) of the extra electrons. The cell polarization is used to encode binary information. Because the polarization of a nonisolated cell depends on Coulomb-repulsion interactions with neighboring cells, universal logic gates and binary wires could be constructed, in principle, by arraying QCA of suitable design in suitable patterns. Again, for reasons too complex to describe here, in order to ensure accuracy and timeliness of the output of a QCA array, it is necessary to resort to an adiabatic switching scheme in which the QCA array is divided into subarrays, each controlled by a different phase of a multiphase clock signal. In this scheme, each subarray is given time to perform its computation, then its state is frozen by raising its inter-dot potential barriers and its output is fed as the input to the successor subarray. The successor subarray is kept in an unpolarized state so it does not influence the calculation of preceding subarray. Such a clocking scheme is consistent with pipeline computation in the sense that each different subarray can perform a different part of an overall computation. In other words, QCA arrays are inherently suitable for pipeline and, moreover, systolic computations. This sequential or pipeline aspect of QCA would be utilized in the proposed bit-serial adders.

Fabrication of gold dot, ring, and corpuscle arrays from block copolymer templates via a simple modification of surface energy

NASA Astrophysics Data System (ADS)

Cho, Heesook; Choi, Sinho; Kim, Jin Young; Park, Soojin

2011-12-01

We demonstrate a simple method for tuning the morphologies of as-spun micellar thin films by modifying the surface energy of silicon substrates. When a polystyrene-block-poly(2-vinylpyridine) (PS-b-P2VP) copolymer dissolved in o-xylene was spin-coated onto a PS-modified surface, a dimple-type structure consisting of a thick PS shell and P2VP core was obtained. Subsequently, when the films were immersed in metal precursor solutions at certain periods of time and followed by plasma treatment, metal individual dots in a ring-shaped structure, metal nanoring, and metal corpuscle arrays were fabricated, depending on the loading amount of metal precursors. In contrast, when PS-b-P2VP films cast onto silicon substrates with a native oxide were used as templates, only metal dotted arrays were obtained. The combination of micellar thin film and surface energy modification offers an effective way to fabricate various nanostructured metal or metal oxide films.We demonstrate a simple method for tuning the morphologies of as-spun micellar thin films by modifying the surface energy of silicon substrates. When a polystyrene-block-poly(2-vinylpyridine) (PS-b-P2VP) copolymer dissolved in o-xylene was spin-coated onto a PS-modified surface, a dimple-type structure consisting of a thick PS shell and P2VP core was obtained. Subsequently, when the films were immersed in metal precursor solutions at certain periods of time and followed by plasma treatment, metal individual dots in a ring-shaped structure, metal nanoring, and metal corpuscle arrays were fabricated, depending on the loading amount of metal precursors. In contrast, when PS-b-P2VP films cast onto silicon substrates with a native oxide were used as templates, only metal dotted arrays were obtained. The combination of micellar thin film and surface energy modification offers an effective way to fabricate various nanostructured metal or metal oxide films. Electronic supplementary information (ESI) available: AFM images of Au nanorings prepared from a mixed solvent and characterization of PS-b-P2VP micellar films. See DOI: 10.1039/c1nr11075f

Quantum cellular automata

NASA Astrophysics Data System (ADS)

Porod, Wolfgang; Lent, Craig S.; Bernstein, Gary H.

1994-06-01

The Notre Dame group has developed a new paradigm for ultra-dense and ultra-fast information processing in nanoelectronic systems. These Quantum Cellular Automata (QCA's) are the first concrete proposal for a technology based on arrays of coupled quantum dots. The basic building block of these cellular arrays is the Notre Dame Logic Cell, as it has been called in the literature. The phenomenon of Coulomb exclusion, which is a synergistic interplay of quantum confinement and Coulomb interaction, leads to a bistable behavior of each cell which makes possible their use in large-scale cellular arrays. The physical interaction between neighboring cells has been exploited to implement logic functions. New functionality may be achieved in this fashion, and the Notre Dame group invented a versatile majority logic gate. In a series of papers, the feasibility of QCA wires, wire crossing, inverters, and Boolean logic gates was demonstrated. A major finding is that all logic functions may be integrated in a hierarchial fashion which allows the design of complicated QCA structures. The most complicated system which was simulated to date is a one-bit full adder consisting of some 200 cells. In addition to exploring these new concepts, efforts are under way to physically realize such structures both in semiconductor and metal systems. Extensive modeling work of semiconductor quantum dot structures has helped identify optimum design parameters for QCA experimental implementations.

In-situ immobilization of quantum dots in polysaccharide-based nanogels for integration of optical pH-sensing, tumor cell imaging, and drug delivery.

PubMed

Wu, Weitai; Aiello, Michael; Zhou, Ting; Berliner, Alexandra; Banerjee, Probal; Zhou, Shuiqin

2010-04-01

We report a class of polysaccharide-based hybrid nanogels that can integrate the functional building blocks for optical pH-sensing, cancer cell imaging, and controlled drug release into a single nanoparticle system, which can offer broad opportunities for combined diagnosis and therapy. The hybrid nanogels were prepared by in-situ immobilization of CdSe quantum dots (QDs) in the interior of the pH and temperature dual responsive hydroxypropylcellulose-poly(acrylic acid) (HPC-PAA) semi-interpenetrating polymer networks. The-OH groups of the HPC chains are designed to sequester the precursor Cd(2+) ions into the nanogels as well as stabilize the in-situ formed CdSe QDs. The pH-sensitive PAA network chains are designed to induce a pH-responsive volume phase transition of the hybrid nanogels. The developed HPC-PAA-CdSe hybrid nanogels combine a strong trap emission at 741nm for sensing physicochemical environment in a pH dependent manner and a visible excitonic emission at 592nm for mouse melanoma B16F10 cell imaging. The hybrid nanogels also provide excellent stability as a drug carrier, which cannot only provide a high drug loading capacity for a model anticancer drug temozolomide, but also offer a pH-triggered sustained-release of the drug molecules in the gel network. Copyright 2010 Elsevier Ltd. All rights reserved.

The Development of Spatial Skills through Interventions Involving Block Building Activities

ERIC Educational Resources Information Center

Casey, Beth M.; Andrews, Nicole; Schindler, Holly; Kersh, Joanne E.; Samper, Alexandra; Copley, Juanita

2008-01-01

This study investigated the use of block-building interventions to develop spatial-reasoning skills in kindergartners. Two intervention conditions and a control condition were included to determine, first, whether the block building activities themselves benefited children's spatial skills, and secondly, whether a story context further improved…

Incorporating GIS building data and census housing statistics for sub-block-level population estimation

USGS Publications Warehouse

Wu, S.-S.; Wang, L.; Qiu, X.

2008-01-01

This article presents a deterministic model for sub-block-level population estimation based on the total building volumes derived from geographic information system (GIS) building data and three census block-level housing statistics. To assess the model, we generated artificial blocks by aggregating census block areas and calculating the respective housing statistics. We then applied the model to estimate populations for sub-artificial-block areas and assessed the estimates with census populations of the areas. Our analyses indicate that the average percent error of population estimation for sub-artificial-block areas is comparable to those for sub-census-block areas of the same size relative to associated blocks. The smaller the sub-block-level areas, the higher the population estimation errors. For example, the average percent error for residential areas is approximately 0.11 percent for 100 percent block areas and 35 percent for 5 percent block areas.

Balancing the Electron and Hole Transfer for Efficient Quantum Dot Light-Emitting Diodes by Employing a Versatile Organic Electron-Blocking Layer.

PubMed

Jin, Xiao; Chang, Chun; Zhao, Weifeng; Huang, Shujuan; Gu, Xiaobing; Zhang, Qin; Li, Feng; Zhang, Yubao; Li, Qinghua

2018-05-09

The electron-blocking layer (EBL) is important to balance the charge carrier transfer and achieve highly efficient quantum dot light-emitting diodes (QLEDs). Here, we report the utilization of a soluble tert-butyldimethylsilyl chloride-modified poly( p-phenylene benzobisoxazole) (TBS-PBO) as an EBL for simultaneous good charge carrier transfer balance while maintaining a high current density. We show that the versatile TBS-PBO blocks excess electron injection into the quantum dots (QDs), thus leading to better charge carrier transfer balance. It also restricts the undesired QD-to-EBL electron-transfer process, which preserves the superior emission capabilities of the emitter. As a consequence, the TBS-PBO device delivers an external quantum efficiency (EQE) maximum of 16.7% along with a remarkable current density as high as 139 mA/cm 2 with a brightness of 5484 cd/m 2 . The current density of our device is higher than those of insulator EBL-based devices because of the higher conductivity of the TBS-PBO versus insulator EBL, thus helping achieve high luminance values ranging from 1414 to 20 000 cd/cm 2 with current densities ranging from 44 to 648 mA/cm 2 and EQE > 14%. We believe that these unconventional features of the present TBS-PBO-based QLEDs will expand the wide use of TBS-PBO as buffer layers in other advanced QLED applications.

Intelligent transportation systems Professional Capacity Building Program : framework and overview for establishing a professional capacity building program for transportation management and traveler information services in support of ITS deployment

DOT National Transportation Integrated Search

1997-09-30

This document has been prepared to describe how the U.S. Department of Transportations (US DOT) Five- Year Strategic Plan for Professional Capacity Building for ITS Transportation Management and Traveler Information Services is being implemented, ...

Highly efficient luminescent solar concentrators based on earth-abundant indirect-bandgap silicon quantum dots

NASA Astrophysics Data System (ADS)

Meinardi, Francesco; Ehrenberg, Samantha; Dhamo, Lorena; Carulli, Francesco; Mauri, Michele; Bruni, Francesco; Simonutti, Roberto; Kortshagen, Uwe; Brovelli, Sergio

2017-02-01

Building-integrated photovoltaics is gaining consensus as a renewable energy technology for producing electricity at the point of use. Luminescent solar concentrators (LSCs) could extend architectural integration to the urban environment by realizing electrode-less photovoltaic windows. Crucial for large-area LSCs is the suppression of reabsorption losses, which requires emitters with negligible overlap between their absorption and emission spectra. Here, we demonstrate the use of indirect-bandgap semiconductor nanostructures such as highly emissive silicon quantum dots. Silicon is non-toxic, low-cost and ultra-earth-abundant, which avoids the limitations to the industrial scaling of quantum dots composed of low-abundance elements. Suppressed reabsorption and scattering losses lead to nearly ideal LSCs with an optical efficiency of η = 2.85%, matching state-of-the-art semi-transparent LSCs. Monte Carlo simulations indicate that optimized silicon quantum dot LSCs have a clear path to η > 5% for 1 m2 devices. We are finally able to realize flexible LSCs with performances comparable to those of flat concentrators, which opens the way to a new design freedom for building-integrated photovoltaics elements.

Building Blocks: Enmeshing Technology and Creativity with Artistic Pedagogical Technologies

ERIC Educational Resources Information Center

Janzen, Katherine J.; Perry, Beth; Edwards, Margaret

2017-01-01

Using the analogy of children's building blocks, the reader is guided through the results of a research study that explored the use of three Artistic Pedagogical Technologies (APTs). "Building blocks" was the major theme that emerged from the data. Sub-themes included developing community, enhancing creativity, and risk taking. The…

Top Value Added Chemicals From Biomass: I. Results of Screening for Potential Candidates from Sugars and Synthesis Gas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Werpy, Todd A.; Holladay, John E.; White, James F.

2004-11-01

This report identifies twelve building block chemicals that can be produced from sugars via biological or chemical conversions. The twelve building blocks can be subsequently converted to a number of high-value bio-based chemicals or materials. Building block chemicals, as considered for this analysis, are molecules with multiple functional groups that possess the potential to be transformed into new families of useful molecules. The twelve sugar-based building blocks are 1,4-diacids (succinic, fumaric and malic), 2,5-furan dicarboxylic acid, 3-hydroxy propionic acid, aspartic acid, glucaric acid, glutamic acid, itaconic acid, levulinic acid, 3-hydroxybutyrolactone, glycerol, sorbitol, and xylitol/arabinitol. In addition to building blocks, themore » report outlines the central technical barriers that are preventing the widespread use of biomass for products and chemicals.« less

Intercultural Communication Activities in the Classroom: Turning Stumbling Blocks into Building Blocks.

ERIC Educational Resources Information Center

Dillon, Randy K.

This paper explores behavior patterns that inhibit effective communication in everyday, educational, and business cross-cultural settings. Opportunities to change these inhibiting patterns, metaphorically referred to as "stumbling blocks," into building blocks or tools for successful intercultural understandings are discussed in the…

Recommended guide for next generation of transportation design build procurement and contracting in the state of Georgia.

DOT National Transportation Integrated Search

2012-09-01

The overall objective of this research project is to develop a systematic approach that evaluates the appropriateness of Design Build Project Delivery System for a transportation project. State DOTs can benefit from this systematic assessment approac...

Interlocking Toy Building Blocks as Hands-On Learning Modules for Blind and Visually Impaired Chemistry Students

ERIC Educational Resources Information Center

Melaku, Samuel; Schreck, James O.; Griffin, Kameron; Dabke, Rajeev B.

2016-01-01

Interlocking toy building blocks (e.g., Lego) as chemistry learning modules for blind and visually impaired (BVI) students in high school and undergraduate introductory or general chemistry courses are presented. Building blocks were assembled on a baseplate to depict the relative changes in the periodic properties of elements. Modules depicting…

Long lifetime near-infrared-emitting quantum dots for time-gated in vivo imaging of rare circulating cells (Conference Presentation)

NASA Astrophysics Data System (ADS)

Fragola, Alexandra; Bouccara, Sophie; Pezet, Sophie; Lequeux, Nicolas; Loriette, Vincent; Pons, Thomas

2017-02-01

The in vivo detection of rare circulating cells using non invasive fluorescence imaging would provide a key tool to study migration of eg. tumoral or immunological cells. Fluorescence detection is however currently limited by a lack of contrast between the small emission of isolated, fast circulating cells and the strong autofluorescence background of the surrounding tissues. We present the development of near infrared emitting quantum dots (NIR-QDs) with long fluorescence lifetime for sensitive time-gated in vivo imaging of circulating cells. These QDs are composed of low toxicity ZnCuInSe/ZnS materials and made biocompatible using a novel multidentate imidazole zwitterionic block copolymer, ensuring their long term intracellular stability. Cells of interest can thus be labeled ex vivo with QDs, injected intravenously and imaged in the near infrared range. Excitation using a pulsed laser coupled to time-gated detection enables the efficient rejection of short lifetime (≈ ns) autofluorescence background and detection of long lifetime (≈ 150 ns) fluorescence from QD-labeled cells. We demonstrate efficient in vivo imaging of single fast-flowing cells, which opens opportunities for future biological studies. [1] M. Tasso et al, "Sulfobetaine-Vinylimidazole block copolymers: a robust quantum dot surface chemistry expanding bioimaging's horizons", ACS Nano, 9(11), 2015 [2] S. Bouccara et al, "Time-gated cell imaging using long lifetime near-infrared-emitting quantum dots for autofluorescence rejection", J Biomed Optc, 19(5), 2014

The Building Blocks of Life Move from Ground to Tree to Animal and Back to Ground

NASA Astrophysics Data System (ADS)

Davidson, E. A.

2015-12-01

I generally use combinations of big words to describe my science, such as biogeochemistry, ecosystem ecology, nutrient cycling, stoichiometry, tropical deforestation, land-use change, agricultural intensification, eutrophication, greenhouse gas emissions, and sustainable development. I didn't expect to use any of these words, but I was surprised that I couldn't use some others that seem simple enough to me, such as farm, plant, soil, and forest. I landed on "building blocks" as my metaphor for the forms of carbon, nitrogen, phosphorus, and other elements that I study as they cycle through and among ecosystems. I study what makes trees and other kinds of life grow. We all know that they need the sun and that they take up water from the ground, but what else do trees need from the ground? What do animals that eat leaves and wood get from the trees? Just as we need building blocks to grow our bodies, trees and animals also need building blocks for growing their bodies. Trees get part of their building blocks from the ground and animals get theirs from what they eat. When animals poop and when leaves fall, some of their building blocks return to the ground. When they die, their building blocks also go back to the ground. I also study what happens to the ground, the water, and the air when we cut down trees, kill or shoo away the animals, and make fields to grow our food. Can we grow enough food and still keep the ground, water, and air clean? I think the answer is yes, but it will take better understanding of how all of those building blocks fit together and move around, from ground to tree to animal and back to ground.

Building Curriculum during Block Play

ERIC Educational Resources Information Center

Andrews, Nicole

2015-01-01

Blocks are not just for play! In this article, Nicole Andrews describes observing the interactions of three young boys enthusiastically engaged in the kindergarten block center of their classroom, using blocks in a building project that displayed their ability to use critical thinking skills, physics exploration, and the development of language…

Peptide Coated Quantum Dots for Biological Applications

PubMed Central

Iyer, Gopal; Pinaud, Fabien; Tsay, James; Li, Jack J.; Bentolila, Laurent A.; Michalet, Xavier; Weiss, Shimon

2011-01-01

Quantum dots (QDOTs) have been widely recognized by the scientific community and the biotechnology industry, as witnessed by the exponential growth of this field in the past several years. We describe the synthesis and characterization of visible and near infrared QDots—a critical step for engineering organic molecules like proteins and peptides for building nanocomposite materials with multifunctional properties suitable for biological applications. PMID:17181021

The 10 Building Blocks of High-Performing Primary Care

PubMed Central

Bodenheimer, Thomas; Ghorob, Amireh; Willard-Grace, Rachel; Grumbach, Kevin

2014-01-01

Our experiences studying exemplar primary care practices, and our work assisting other practices to become more patient centered, led to a formulation of the essential elements of primary care, which we call the 10 building blocks of high-performing primary care. The building blocks include 4 foundational elements—engaged leadership, data-driven improvement, empanelment, and team-based care—that assist the implementation of the other 6 building blocks—patient-team partnership, population management, continuity of care, prompt access to care, comprehensiveness and care coordination, and a template of the future. The building blocks, which represent a synthesis of the innovative thinking that is transforming primary care in the United States, are both a description of existing high-performing practices and a model for improvement. PMID:24615313

Characteristics of Recycled Concrete Aggregates from Precast Slab Block Buildings

NASA Astrophysics Data System (ADS)

Venkrbec, Václav; Nováková, Iveta; Henková, Svatava

2017-10-01

Precast slab block buildings (PSBB) typically and frequently occur in Central and Eastern Europe, as well as elsewhere in the world. Some of these buildings are currently used beyond their service life capacity. The utilization of recycled materials from these buildings with regard to applying the principles of sustainable construction and using recycled materials will probably be significant in the following years. Documentation from the manufacturing processes of prefabricated blocks for precast slab block buildings is not available, and also it is difficult to declare technological discipline during the construction of these buildings. Therefore, properties of recycled concrete aggregates (RCA) produced from construction and demolition waste (C&DW) of precast slab block buildings build between 1950s to 1990s are not sufficiently known. The demolition of these buildings is very rare today, but it can be assumed an increase in demolitions of these buildings in the future. The use of RCA in new concrete requires verification/testing of the geometrical and physical properties of RCA according to the EN 12 620+A1 standard. The aim of the contribution is to present a case study of the demolition of slab block building with emphasis on RCA usage. The paper presents the results of the tests according to European standards for determining selected geometrical and physical properties of the RCA. The paper describes and evaluates tests such as determination of particle size distribution - Sieve Analysis, content of fine particles, determination of density and water absorption. The results of the properties testing of RCA are compared with the properties of natural aggregate. The general boundary conditions of RCA particular tests are presented.

Overview and Summary of Advanced UVOIR Mirror Technology Development (AMTD) Project

NASA Technical Reports Server (NTRS)

Stahl, H. Philip

2014-01-01

ASTRO2010 Decadal Survey stated that an advanced large-aperture ultraviolet, optical, near-infrared (UVOIR) telescope is required to enable the next generation of compelling astrophysics and exoplanet science; and, that present technology is not mature enough to affordably build and launch any potential UVOIR mission concept. AMTD is a multiyear effort to develop, demonstrate and mature critical technologies to TRL-6 by 2018 so that a viable flight mission can be proposed to the 2020 Decadal Review. AMTD builds on the state of art (SOA) defined by over 30 years of monolithic & segmented ground & space-telescope mirror technology to mature six key technologies: center dotLarge-Aperture, Low Areal Density, High Stiffness Mirror Substrates: Both (4 to 8 m) monolithic and (8 to 16 m) segmented telescopes require larger and stiffer mirrors. center dotSupport System: Large-aperture mirrors require large support systems to ensure that they survive launch, deploy on orbit, and maintain a stable, undistorted shape. center dotMid/High Spatial Frequency Figure Error: Very smooth mirror is critical for producing high-quality point spread function (PSF) for high contrast imaging. center dotSegment Edges: The quality of segment edges impacts PSF for high-contrast imaging applications, contributes to stray light noise, and affects total collecting aperture. center dotSegment to Segment Gap Phasing: Segment phasing is critical for producing high-quality temporally-stable PSF. center dotIntegrated Model Validation: On-orbit performance is driven by mechanical & thermal stability. Compliance cannot be 100% tested, but relies on modeling. Because we cannot predict the future, AMTD is pursuing multiple design paths to provide the science community with options to enable either large aperture monolithic or segmented mirrors with clear engineering metrics traceable to science requirements

INFERENCE BUILDING BLOCKS

DTIC Science & Technology

2018-02-15

address the problem that probabilistic inference algorithms are diÿcult and tedious to implement, by expressing them in terms of a small number of...building blocks, which are automatic transformations on probabilistic programs. On one hand, our curation of these building blocks reflects the way human...reasoning with low-level computational optimization, so the speed and accuracy of the generated solvers are competitive with state-of-the-art systems. 15

1. John C. Garner, Jr., Photographer 1967 PRINCIPAL (NORTH) SIDE, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

1. John C. Garner, Jr., Photographer 1967 PRINCIPAL (NORTH) SIDE, FROM NORTHWEST. THE RIGHT END OF THE BLOCK IS THE E.S. WOOD BUILDING; THE BUILDING WITH A FIRE ESCAPE IS THE ROSENFIELD BUILDING; THE T.W. HOUSE BUILDING IS TO THE LEFT OF THE PRECEDING BUILDING; JOHN BERLOCHER BUILDING IS AT THE LEFT END OF THE BLOCK. - Strand Historic District, Wood-Rosenfield-House-Berlocher Buildings, 2213-2223 Strand, Galveston, Galveston County, TX

Direct photonic coupling of a semiconductor quantum dot and a trapped ion.

PubMed

Meyer, H M; Stockill, R; Steiner, M; Le Gall, C; Matthiesen, C; Clarke, E; Ludwig, A; Reichel, J; Atatüre, M; Köhl, M

2015-03-27

Coupling individual quantum systems lies at the heart of building scalable quantum networks. Here, we report the first direct photonic coupling between a semiconductor quantum dot and a trapped ion and we demonstrate that single photons generated by a quantum dot controllably change the internal state of a Yb^{+} ion. We ameliorate the effect of the 60-fold mismatch of the radiative linewidths with coherent photon generation and a high-finesse fiber-based optical cavity enhancing the coupling between the single photon and the ion. The transfer of information presented here via the classical correlations between the σ_{z} projection of the quantum-dot spin and the internal state of the ion provides a promising step towards quantum-state transfer in a hybrid photonic network.

A Library of Rad Hard Mixed-Voltage/Mixed-Signal Building Blocks for Integration of Avionics Systems for Deep Space

NASA Technical Reports Server (NTRS)

Mojarradi, M. M.; Blaes, B.; Kolawa, E. A.; Blalock, B. J.; Li, H. W.; Buck, K.; Houge, D.

2001-01-01

To build the sensor intensive system-on-a-chip for the next generation spacecrafts for deep space, Center for Integration of Space Microsystems at JPL (CISM) takes advantage of the lower power rating and inherent radiation resistance of Silicon on Insulator technology (SOI). We are developing a suite of mixed-voltage and mixed-signal building blocks in Honeywell's SOI process that can enable the rapid integration of the next generation avionics systems with lower power rating, higher reliability, longer life, and enhanced radiation tolerance for spacecrafts such as the Europa Orbiter and Europa Lander. The mixed-voltage building blocks are predominantly for design of adaptive power management systems. Their design centers around an LDMOS structure that is being developed by Honeywell, Boeing Corp, and the University of Idaho. The mixed-signal building blocks are designed to meet the low power, extreme radiation requirement of deep space applications. These building blocks are predominantly used to interface analog sensors to the digital CPU of the next generation avionics system on a chip. Additional information is contained in the original extended abstract.

Solvent mediated hybrid 2D materials: black phosphorus - graphene heterostructured building blocks assembled for sodium ion batteries.

PubMed

Li, Mengya; Muralidharan, Nitin; Moyer, Kathleen; Pint, Cary L

2018-06-07

Here we demonstrate the broad capability to exploit interactions at different length scales in 2D materials to prepare macroscopic functional materials containing hybrid black phosphorus/graphene (BP/G) heterostructured building blocks. First, heterostructured 2D building blocks are self-assembled during co-exfoliation in the solution phase based on electrostatic attraction of different 2D materials. Second, electrophoretic deposition is used as a tool to assemble these building blocks into macroscopic films containing these self-assembled 2D heterostructures. Characterization of deposits formed using this technique elucidates the presence of stacked and sandwiched 2D heterostructures, and zeta potential measurements confirm the mechanistic interactions driving this assembly. Building on the exceptional sodium alloying capacity of BP, these materials were demonstrated as superior binder-free and additive-free anodes for sodium batteries with specific discharge capacity of 2365 mA h gP-1 and long stable cycling duration. This study demonstrates how controllable co-processing of 2D materials can enable material control for stacking and building block assembly relevant to broad future applications of 2D materials.

Printed photodetectors

NASA Astrophysics Data System (ADS)

Pace, Giuseppina; Grimoldi, Andrea; Sampietro, Marco; Natali, Dario; Caironi, Mario

2015-10-01

Photodetectors convert light pulses into electrical signals and are fundamental building blocks for any opto-electronic system adopting light as a probe or information carrier. They have widespread technological applications, from telecommunications to sensors in industrial, medical and civil environments. Further opportunities are plastic short-range communications systems, interactive large-area surfaces and light-weight, flexible, digital imagers. These applications would greatly benefit from the cost-effective fabrication processes enabled by printing technology. While organic semiconductors are the most investigated materials for printed photodetectors, and are the main focus of the present review, there are notable examples of other inorganic or hybrid printable semiconductors for opto-electronic systems, such as quantum-dots and nanowires. Here we propose an overview on printed photodetectors, including three-terminal phototransistors. We first give a brief account of the working mechanism of these light sensitive devices, and then we review the recent progress achieved with scalable printing techniques such as screen-printing, inkjet and other non-contact technologies in the development of all-printed or hybrid systems.

Complete tomography of a high-fidelity solid-state entangled spin-photon qubit pair.

PubMed

De Greve, Kristiaan; McMahon, Peter L; Yu, Leo; Pelc, Jason S; Jones, Cody; Natarajan, Chandra M; Kim, Na Young; Abe, Eisuke; Maier, Sebastian; Schneider, Christian; Kamp, Martin; Höfling, Sven; Hadfield, Robert H; Forchel, Alfred; Fejer, M M; Yamamoto, Yoshihisa

2013-01-01

Entanglement between stationary quantum memories and photonic qubits is crucial for future quantum communication networks. Although high-fidelity spin-photon entanglement was demonstrated in well-isolated atomic and ionic systems, in the solid-state, where massively parallel, scalable networks are most realistically conceivable, entanglement fidelities are typically limited due to intrinsic environmental interactions. Distilling high-fidelity entangled pairs from lower-fidelity precursors can act as a remedy, but the required overhead scales unfavourably with the initial entanglement fidelity. With spin-photon entanglement as a crucial building block for entangling quantum network nodes, obtaining high-fidelity entangled pairs becomes imperative for practical realization of such networks. Here we report the first results of complete state tomography of a solid-state spin-photon-polarization-entangled qubit pair, using a single electron-charged indium arsenide quantum dot. We demonstrate record-high fidelity in the solid-state of well over 90%, and the first (99.9%-confidence) achievement of a fidelity that will unambiguously allow for entanglement distribution in solid-state quantum repeater networks.

Overcoming correlation fluctuations in two-photon interference experiments with differently bright and independently blinking remote quantum emitters

NASA Astrophysics Data System (ADS)

Weber, Jonas H.; Kettler, Jan; Vural, Hüseyin; Müller, Markus; Maisch, Julian; Jetter, Michael; Portalupi, Simone L.; Michler, Peter

2018-05-01

As a fundamental building block for quantum computation and communication protocols, the correct verification of the two-photon interference (TPI) contrast between two independent quantum light sources is of utmost importance. Here, we experimentally demonstrate how frequently present blinking dynamics and changes in emitter brightness critically affect the Hong-Ou-Mandel-type (HOM) correlation histograms of remote TPI experiments measured via the commonly utilized setup configuration. We further exploit this qualitative and quantitative explanation of the observed correlation dynamics to establish an alternative interferometer configuration, which is overcoming the discussed temporal fluctuations, giving rise to an error-free determination of the remote TPI visibility. We prove full knowledge of the obtained correlation by reproducing the measured correlation statistics via Monte Carlo simulations. As an exemplary system, we make use of two pairs of remote semiconductor quantum dots; however, the same conclusions apply for TPI experiments with flying qubits from any kind of remote solid-state quantum emitters.

Approaching the resolution limit of W-C nano-gaps using focused ion beam chemical vapour deposition

NASA Astrophysics Data System (ADS)

Dai, Jun; Chang, Hui; Maeda, Etsuo; Warisawa, Shin'ichi; Kometani, Reo

2018-01-01

Nano-gaps are fundamental building blocks for nanochannels, plasmonic nanostructures and superconducting Josephson junctions. We present a systematic study on the formation mechanism and resolution limit of W-C nano-gaps fabricated using focused-ion-beam chemical vapour deposition (FIB-CVD). First, the deposition size of the nanostructures is evaluated. The size averaged over 100 dots is 32 nm at FWHM. Line and space are also fabricated with the smallest size, having a spacing of only 5 nm at FWHM. Then, a model is developed to study the formation mechanism and provides the design basis for W-C nano-gaps. Both experimental and simulation results reveal that the shrinkage of W-C nano-gaps is accelerated as the Gaussian parts of the nano-wire profiles overlap. A Nano-gap with a length of 5 nm and height difference as high as 42 nm is synthesized. We believe that FIB-CVD opens avenues for novel functional nanodevices that can be potentially used for biosensing, photodetecting, or quantum computing.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wei, Guohua; Czaplewski, David A.; Lenferink, Erik J.

Three-dimensional confinement allows semiconductor quantum dots to exhibit size-tunable electronic and optical properties that enable a wide range of opto-electronic applications from displays, solar cells and bio-medical imaging to single-electron devices. Additional modalities such as spin and valley properties in monolayer transition metal dichalcogenides provide further degrees of freedom requisite for information processing and spintronics. In nanostructures, however, spatial confinement can cause hybridization that inhibits the robustness of these emergent properties. Here in this paper, we show that laterally-confined excitons in monolayer MoS 2 nanodots can be created through top-down nanopatterning with controlled size tunability. Unlike chemically-exfoliated monolayer nanoparticles, themore » lithographically patterned monolayer semiconductor nanodots down to a radius of 15 nm exhibit the same valley polarization as in a continuous monolayer sheet. The inherited bulk spin and valley properties, the size dependence of excitonic energies, and the ability to fabricate MoS 2 nanostructures using semiconductor-compatible processing suggest that monolayer semiconductor nanodots have potential to be multimodal building blocks of integrated optoelectronics and spintronics systems« less

Time-to-digital converter card for multichannel time-resolved single-photon counting applications

NASA Astrophysics Data System (ADS)

Tamborini, Davide; Portaluppi, Davide; Tisa, Simone; Tosi, Alberto

2015-03-01

We present a high performance Time-to-Digital Converter (TDC) card that provides 10 ps timing resolution and 20 ps (rms) timing precision with a programmable full-scale-range from 160 ns to 10 μs. Differential Non-Linearity (DNL) is better than 1.3% LSB (rms) and Integral Non-Linearity (INL) is 5 ps rms. Thanks to the low power consumption (400 mW) and the compact size (78 mm x 28 mm x 10 mm), this card is the building block for developing compact multichannel time-resolved instrumentation for Time-Correlated Single-Photon Counting (TCSPC). The TDC-card outputs the time measurement results together with the rates of START and STOP signals and the number of valid TDC conversions. These additional information are needed by many TCSPC-based applications, such as: Fluorescence Lifetime Imaging (FLIM), Time-of-Flight (TOF) ranging measurements, time-resolved Positron Emission Tomography (PET), single-molecule spectroscopy, Fluorescence Correlation Spectroscopy (FCS), Diffuse Optical Tomography (DOT), Optical Time-Domain Reflectometry (OTDR), quantum optics, etc.

Nanoparticle Superlattices: The Roles of Soft Ligands

PubMed Central

Si, Kae Jye; Chen, Yi; Shi, Qianqian

2017-01-01

Abstract Nanoparticle superlattices are periodic arrays of nanoscale inorganic building blocks including metal nanoparticles, quantum dots and magnetic nanoparticles. Such assemblies can exhibit exciting new collective properties different from those of individual nanoparticle or corresponding bulk materials. However, fabrication of nanoparticle superlattices is nontrivial because nanoparticles are notoriously difficult to manipulate due to complex nanoscale forces among them. An effective way to manipulate these nanoscale forces is to use soft ligands, which can prevent nanoparticles from disordered aggregation, fine‐tune the interparticle potential as well as program lattice structures and interparticle distances – the two key parameters governing superlattice properties. This article aims to review the up‐to‐date advances of superlattices from the viewpoint of soft ligands. We first describe the theories and design principles of soft‐ligand‐based approach and then thoroughly cover experimental techniques developed from soft ligands such as molecules, polymer and DNA. Finally, we discuss the remaining challenges and future perspectives in nanoparticle superlattices. PMID:29375958

Wet etch methods for InAs nanowire patterning and self-aligned electrical contacts

NASA Astrophysics Data System (ADS)

Fülöp, G.; d'Hollosy, S.; Hofstetter, L.; Baumgartner, A.; Nygård, J.; Schönenberger, C.; Csonka, S.

2016-05-01

Advanced synthesis of semiconductor nanowires (NWs) enables their application in diverse fields, notably in chemical and electrical sensing, photovoltaics, or quantum electronic devices. In particular, indium arsenide (InAs) NWs are an ideal platform for quantum devices, e.g. they may host topological Majorana states. While the synthesis has been continously perfected, only a few techniques have been developed to tailor individual NWs after growth. Here we present three wet chemical etch methods for the post-growth morphological engineering of InAs NWs on the sub-100 nm scale. The first two methods allow the formation of self-aligned electrical contacts to etched NWs, while the third method results in conical shaped NW profiles ideal for creating smooth electrical potential gradients and shallow barriers. Low temperature experiments show that NWs with etched segments have stable transport characteristics and can serve as building blocks of quantum electronic devices. As an example we report the formation of a single electrically stable quantum dot between two etched NW segments.

Simultaneous Faraday filtering of the Mollow triplet sidebands with the Cs-D1 clock transition.

PubMed

Portalupi, Simone Luca; Widmann, Matthias; Nawrath, Cornelius; Jetter, Michael; Michler, Peter; Wrachtrup, Jörg; Gerhardt, Ilja

2016-11-25

Hybrid quantum systems integrating semiconductor quantum dots (QDs) and atomic vapours become important building blocks for scalable quantum networks due to the complementary strengths of individual parts. QDs provide on-demand single-photon emission with near-unity indistinguishability comprising unprecedented brightness-while atomic vapour systems provide ultra-precise frequency standards and promise long coherence times for the storage of qubits. Spectral filtering is one of the key components for the successful link between QD photons and atoms. Here we present a tailored Faraday anomalous dispersion optical filter based on the caesium-D 1 transition for interfacing it with a resonantly pumped QD. The presented Faraday filter enables a narrow-bandwidth (Δω=2π × 1 GHz) simultaneous filtering of both Mollow triplet sidebands. This result opens the way to use QDs as sources of single as well as cascaded photons in photonic quantum networks aligned to the primary frequency standard of the caesium clock transition.

Top Value Added Chemicals from Biomass - Volume I, Results of Screening for Potential Candidates from Sugars and Synthesis Gas

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

2004-08-01

This report identifies twelve building block chemicals that can be produced from sugars via biological or chemical conversions. The twelve building blocks can be subsequently converted to a number of high-value bio-based chemicals or materials. Building block chemicals, as considered for this analysis, are molecules with multiple functional groups that possess the potential to be transformed into new families of useful molecules. The twelve sugar-based building blocks are 1,4-diacids (succinic, fumaric and malic), 2,5-furan dicarboxylic acid, 3-hydroxy propionic acid, aspartic acid, glucaric acid, glutamic acid, itaconic acid, levulinic acid, 3-hydroxybutyrolactone, glycerol, sorbitol, and xylitol/arabinitol.

Top Value Added Chemicals from Biomass: Volume I -- Results of Screening for Potential Candidates from Sugars and Synthesis Gas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Werpy, T.; Petersen, G.

2004-08-01

This report identifies twelve building block chemicals that can be produced from sugars via biological or chemical conversions. The twelve building blocks can be subsequently converted to a number of high-value bio-based chemicals or materials. Building block chemicals, as considered for this analysis, are molecules with multiple functional groups that possess the potential to be transformed into new families of useful molecules. The twelve sugar-based building blocks are 1,4-diacids (succinic, fumaric and malic), 2,5-furan dicarboxylic acid, 3-hydroxy propionic acid, aspartic acid, glucaric acid, glutamic acid, itaconic acid, levulinic acid, 3-hydroxybutyrolactone, glycerol, sorbitol, and xylitol/arabinitol.

The influence of graphic display format on the interpretations of quantitative risk information among adults with lower education and literacy: a randomized experimental study.

PubMed

McCaffery, Kirsten J; Dixon, Ann; Hayen, Andrew; Jansen, Jesse; Smith, Sian; Simpson, Judy M

2012-01-01

To test optimal graphic risk communication formats for presenting small probabilities using graphics with a denominator of 1000 to adults with lower education and literacy. A randomized experimental study, which took place in adult basic education classes in Sydney, Australia. The participants were 120 adults with lower education and literacy. An experimental computer-based manipulation compared 1) pictographs in 2 forms, shaded "blocks" and unshaded "dots"; and 2) bar charts across different orientations (horizontal/vertical) and numerator size (small <100, medium 100-499, large 500-999). Accuracy (size of error) and ease of processing (reaction time) were assessed on a gist task (estimating the larger chance of survival) and a verbatim task (estimating the size of difference). Preferences for different graph types were also assessed. Accuracy on the gist task was very high across all conditions (>95%) and not tested further. For the verbatim task, optimal graph type depended on the numerator size. For small numerators, pictographs resulted in fewer errors than bar charts (blocks: odds ratio [OR] = 0.047, 95% confidence interval [CI] = 0.023-0.098; dots: OR = 0.049, 95% CI = 0.024-0.099). For medium and large numerators, bar charts were more accurate (e.g., medium dots: OR = 4.29, 95% CI = 2.9-6.35). Pictographs were generally processed faster for small numerators (e.g., blocks: 14.9 seconds v. bars: 16.2 seconds) and bar charts for medium or large numerators (e.g., large blocks: 41.6 seconds v. 26.7 seconds). Vertical formats were processed slightly faster than horizontal graphs with no difference in accuracy. Most participants preferred bar charts (64%); however, there was no relationship with performance. For adults with low education and literacy, pictographs are likely to be the best format to use when displaying small numerators (<100/1000) and bar charts for larger numerators (>100/1000).

Computational strategies for the automated design of RNA nanoscale structures from building blocks using NanoTiler.

PubMed

Bindewald, Eckart; Grunewald, Calvin; Boyle, Brett; O'Connor, Mary; Shapiro, Bruce A

2008-10-01

One approach to designing RNA nanoscale structures is to use known RNA structural motifs such as junctions, kissing loops or bulges and to construct a molecular model by connecting these building blocks with helical struts. We previously developed an algorithm for detecting internal loops, junctions and kissing loops in RNA structures. Here we present algorithms for automating or assisting many of the steps that are involved in creating RNA structures from building blocks: (1) assembling building blocks into nanostructures using either a combinatorial search or constraint satisfaction; (2) optimizing RNA 3D ring structures to improve ring closure; (3) sequence optimisation; (4) creating a unique non-degenerate RNA topology descriptor. This effectively creates a computational pipeline for generating molecular models of RNA nanostructures and more specifically RNA ring structures with optimized sequences from RNA building blocks. We show several examples of how the algorithms can be utilized to generate RNA tecto-shapes.

Computational strategies for the automated design of RNA nanoscale structures from building blocks using NanoTiler☆

PubMed Central

Bindewald, Eckart; Grunewald, Calvin; Boyle, Brett; O’Connor, Mary; Shapiro, Bruce A.

2013-01-01

One approach to designing RNA nanoscale structures is to use known RNA structural motifs such as junctions, kissing loops or bulges and to construct a molecular model by connecting these building blocks with helical struts. We previously developed an algorithm for detecting internal loops, junctions and kissing loops in RNA structures. Here we present algorithms for automating or assisting many of the steps that are involved in creating RNA structures from building blocks: (1) assembling building blocks into nanostructures using either a combinatorial search or constraint satisfaction; (2) optimizing RNA 3D ring structures to improve ring closure; (3) sequence optimisation; (4) creating a unique non-degenerate RNA topology descriptor. This effectively creates a computational pipeline for generating molecular models of RNA nanostructures and more specifically RNA ring structures with optimized sequences from RNA building blocks. We show several examples of how the algorithms can be utilized to generate RNA tecto-shapes. PMID:18838281

Synthesis of most polyene natural product motifs using just twelve building blocks and one coupling reaction

PubMed Central

Woerly, Eric M.; Roy, Jahnabi; Burke, Martin D.

2014-01-01

The inherent modularity of polypeptides, oligonucleotides, and oligosaccharides has been harnessed to achieve generalized building block-based synthesis platforms. Importantly, like these other targets, most small molecule natural products are biosynthesized via iterative coupling of bifunctional building blocks. This suggests that many small molecules also possess inherent modularity commensurate with systematic building block-based construction. Supporting this hypothesis, here we report that the polyene motifs found in >75% of all known polyene natural products can be synthesized using just 12 building blocks and one coupling reaction. Using the same general retrosynthetic algorithm and reaction conditions, this platform enabled the synthesis of a wide range of polyene frameworks covering all of this natural product chemical space, and first total syntheses of the polyene natural products asnipyrone B, physarigin A, and neurosporaxanthin β-D-glucopyranoside. Collectively, these results suggest the potential for a more generalized approach for making small molecules in the laboratory. PMID:24848233

COMPRESSOR BUILDING, TRA626. ELEVATIONS. WINDOWS. WALL SECTIONS. PUMICE BLOCK BUILDING ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

COMPRESSOR BUILDING, TRA-626. ELEVATIONS. WINDOWS. WALL SECTIONS. PUMICE BLOCK BUILDING HOUSED COMPRESSORS FOR AIRCRAFT NUCLEAR PROPULSION EXPERIMENTS. MTR-626-IDO-2S, 3/1952. INL INDEX NO. 531-0626-00-396-110535, REV. 2. - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

The design organization test: further demonstration of reliability and validity as a brief measure of visuospatial ability.

PubMed

Killgore, William D S; Gogel, Hannah

2014-01-01

Neuropsychological assessments are frequently time-consuming and fatiguing for patients. Brief screening evaluations may reduce test duration and allow more efficient use of time by permitting greater attention toward neuropsychological domains showing probable deficits. The Design Organization Test (DOT) was initially developed as a 2-min paper-and-pencil alternative for the Block Design (BD) subtest of the Wechsler scales. Although initially validated for clinical neurologic patients, we sought to further establish the reliability and validity of this test in a healthy, more diverse population. Two alternate versions of the DOT and the Wechsler Abbreviated Scale of Intelligence (WASI) were administered to 61 healthy adult participants. The DOT showed high alternate forms reliability (r = .90-.92), and the two versions yielded equivalent levels of performance. The DOT was highly correlated with BD (r = .76-.79) and was significantly correlated with all subscales of the WASI. The DOT proved useful when used in lieu of BD in the calculation of WASI IQ scores. Findings support the reliability and validity of the DOT as a measure of visuospatial ability and suggest its potential worth as an efficient estimate of intellectual functioning in situations where lengthier tests may be inappropriate or unfeasible.

Block-circulant matrices with circulant blocks, Weil sums, and mutually unbiased bases. II. The prime power case

DOE Office of Scientific and Technical Information (OSTI.GOV)

Combescure, Monique

2009-03-15

In our previous paper [Combescure, M., 'Circulant matrices, Gauss sums and the mutually unbiased bases. I. The prime number case', Cubo A Mathematical Journal (unpublished)] we have shown that the theory of circulant matrices allows to recover the result that there exists p+1 mutually unbiased bases in dimension p, p being an arbitrary prime number. Two orthonormal bases B, B{sup '} of C{sup d} are said mutually unbiased if for all b(set-membership sign)B, for all b{sup '}(set-membership sign)B{sup '} one has that |b{center_dot}b{sup '}|=1/{radical}(d) (b{center_dot}b{sup '} Hermitian scalar product in C{sup d}). In this paper we show that the theorymore » of block-circulant matrices with circulant blocks allows to show very simply the known result that if d=p{sup n} (p a prime number and n any integer) there exists d+1 mutually unbiased bases in C{sup d}. Our result relies heavily on an idea of Klimov et al. [''Geometrical approach to the discrete Wigner function,'' J. Phys. A 39, 14471 (2006)]. As a subproduct we recover properties of quadratic Weil sums for p{>=}3, which generalizes the fact that in the prime case the quadratic Gauss sum properties follow from our results.« less

Encapsulation of an interpenetrated diamondoid inorganic building block in a metal-organic framework.

PubMed

Zhang, Huabin; Lin, Ping; Chen, Erxia; Tan, Yanxi; Wen, Tian; Aldalbahi, Ali; Alshehri, Saad M; Yamauchi, Yusuke; Du, Shaowu; Zhang, Jian

2015-03-23

The first example of an inorganic-organic composite framework with an interpenetrated diamondoid inorganic building block, featuring unique {InNa}n helices and {In12 Na16 } nano-rings, has been constructed and structurally characterized. This framework also represents a unique example of encapsulation of an interpenetrated diamondoid inorganic building block in a metal-organic framework. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

23. The Stroud Building beard the 'Temme Springs' advertisement. Westfacing ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

23. The Stroud Building beard the 'Temme Springs' advertisement. West-facing windows of the entire block are protected from the afternoon sun by awnings. The north-facing windows of the second-story restaurant were later blocked by an adjacent two-story building. Circa 1914. Credit PPL. - Stroud Building, 31-33 North Central Avenue, Phoenix, Maricopa County, AZ

Polymer-based platform for microfluidic systems

DOEpatents

Benett, William [Livermore, CA; Krulevitch, Peter [Pleasanton, CA; Maghribi, Mariam [Livermore, CA; Hamilton, Julie [Tracy, CA; Rose, Klint [Boston, MA; Wang, Amy W [Oakland, CA

2009-10-13

A method of forming a polymer-based microfluidic system platform using network building blocks selected from a set of interconnectable network building blocks, such as wire, pins, blocks, and interconnects. The selected building blocks are interconnectably assembled and fixedly positioned in precise positions in a mold cavity of a mold frame to construct a three-dimensional model construction of a microfluidic flow path network preferably having meso-scale dimensions. A hardenable liquid, such as poly (dimethylsiloxane) is then introduced into the mold cavity and hardened to form a platform structure as well as to mold the microfluidic flow path network having channels, reservoirs and ports. Pre-fabricated elbows, T's and other joints are used to interconnect various building block elements together. After hardening the liquid the building blocks are removed from the platform structure to make available the channels, cavities and ports within the platform structure. Microdevices may be embedded within the cast polymer-based platform, or bonded to the platform structure subsequent to molding, to create an integrated microfluidic system. In this manner, the new microfluidic platform is versatile and capable of quickly generating prototype systems, and could easily be adapted to a manufacturing setting.

Modeling and simulation of floating gate nanocrystal FET devices and circuits

NASA Astrophysics Data System (ADS)

Hasaneen, El-Sayed A. M.

The nonvolatile memory market has been growing very fast during the last decade, especially for mobile communication systems. The Semiconductor Industry Association International Technology Roadmap for Semiconductors states that the difficult challenge for nonvolatile semiconductor memories is to achieve reliable, low power, low voltage performance and high-speed write/erase. This can be achieved by aggressive scaling of the nonvolatile memory cells. Unfortunately, scaling down of conventional nonvolatile memory will further degrade the retention time due to the charge loss between the floating gate and drain/source contacts and substrate which makes conventional nonvolatile memory unattractive. Using nanocrystals as charge storage sites reduces dramatically the charge leakage through oxide defects and drain/source contacts. Floating gate nanocrystal nonvolatile memory, FG-NCNVM, is a candidate for future memory because it is advantageous in terms of high-speed write/erase, small size, good scalability, low-voltage, low-power applications, and the capability to store multiple bits per cell. Many studies regarding FG-NCNVMs have been published. Most of them have dealt with fabrication improvements of the devices and device characterizations. Due to the promising FG-NCNVM applications in integrated circuits, there is a need for circuit a simulation model to simulate the electrical characteristics of the floating gate devices. In this thesis, a FG-NCNVM circuit simulation model has been proposed. It is based on the SPICE BSIM simulation model. This model simulates the cell behavior during normal operation. Model validation results have been presented. The SPICE model shows good agreement with experimental results. Current-voltage characteristics, transconductance and unity gain frequency (fT) have been studied showing the effect of the threshold voltage shift (DeltaVth) due to nanocrystal charge on the device characteristics. The threshold voltage shift due to nanocrystal charge has a strong effect on the memory characteristics. Also, the programming operation of the memory cell has been investigated. The tunneling rate from quantum well channel to quantum dot (nanocrystal) gate is calculated. The calculations include various memory parameters, wavefunctions, and energies of quantum well channel and quantum dot gate. The use of floating gate nanocrystal memory as a transistor with a programmable threshold voltage has been demonstrated. The incorporation of FG-NCFETs to design programmable integrated circuit building blocks has been discussed. This includes the design of programmable current and voltage reference circuits. Finally, we demonstrated the design of tunable gain op-amp incorporating FG-NCFETs. Programmable integrated circuit building blocks can be used in intelligent analog and digital systems.

Building Blocks for Sustainable Communities: Assistance from Grantees

EPA Pesticide Factsheets

EPA awarded Building Blocks for Sustainable Communities grants to four nonprofit organizations with extensive expertise in community sustainability. These organizations deliver technical assistance to communities.

Comparison of permeable pavement types : hydrology, design, installation, maintenance and cost.

DOT National Transportation Integrated Search

2012-01-13

"WisDOTs regional storm water engineer for the Southeast Region is interested in developing a park-and-ride with : porous pavement, possibly with the PaveDrain brand of permeable block. Research was needed to determine how : well permeable pavemen...

Boosting the efficiency of quantum dot sensitized solar cells through modulation of interfacial charge transfer.

PubMed

Kamat, Prashant V

2012-11-20

The demand for clean energy will require the design of nanostructure-based light-harvesting assemblies for the conversion of solar energy into chemical energy (solar fuels) and electrical energy (solar cells). Semiconductor nanocrystals serve as the building blocks for designing next generation solar cells, and metal chalcogenides (e.g., CdS, CdSe, PbS, and PbSe) are particularly useful for harnessing size-dependent optical and electronic properties in these nanostructures. This Account focuses on photoinduced electron transfer processes in quantum dot sensitized solar cells (QDSCs) and discusses strategies to overcome the limitations of various interfacial electron transfer processes. The heterojunction of two semiconductor nanocrystals with matched band energies (e.g., TiO(2) and CdSe) facilitates charge separation. The rate at which these separated charge carriers are driven toward opposing electrodes is a major factor that dictates the overall photocurrent generation efficiency. The hole transfer at the semiconductor remains a major bottleneck in QDSCs. For example, the rate constant for hole transfer is 2-3 orders of magnitude lower than the electron injection from excited CdSe into oxide (e.g., TiO(2)) semiconductor. Disparity between the electron and hole scavenging rate leads to further accumulation of holes within the CdSe QD and increases the rate of electron-hole recombination. To overcome the losses due to charge recombination processes at the interface, researchers need to accelerate electron and hole transport. The power conversion efficiency for liquid junction and solid state quantum dot solar cells, which is in the range of 5-6%, represents a significant advance toward effective utilization of nanomaterials for solar cells. The design of new semiconductor architectures could address many of the issues related to modulation of various charge transfer steps. With the resolution of those problems, the efficiencies of QDSCs could approach those of dye sensitized solar cells (DSSC) and organic photovoltaics.

Block Play and Mathematics Learning in Preschool: The Effects of Building Complexity, Peer and Teacher Interactions in the Block Area, and Replica Play Materials

ERIC Educational Resources Information Center

Trawick-Smith, Jeffrey; Swaminathan, Sudha; Baton, Brooke; Danieluk, Courtney; Marsh, Samantha; Szarwacki, Monika

2017-01-01

Block play has been included in early childhood classrooms for over a century, yet few studies have examined its effects on learning. Several previous investigations indicate that the complexity of block building is associated with math ability, but these studies were often conducted in adult-guided, laboratory settings. In the present…

DNA-Templated Polymerization of Side-Chain-Functionalized Peptide Nucleic Acid Aldehydes

PubMed Central

Kleiner, Ralph E.; Brudno, Yevgeny; Birnbaum, Michael E.; Liu, David R.

2009-01-01

The DNA-templated polymerization of synthetic building blocks provides a potential route to the laboratory evolution of sequence-defined polymers with structures and properties not necessarily limited to those of natural biopolymers. We previously reported the efficient and sequence-specific DNA-templated polymerization of peptide nucleic acid (PNA) aldehydes. Here, we report the enzyme-free, DNA-templated polymerization of side-chain-functionalized PNA tetramer and pentamer aldehydes. We observed that the polymerization of tetramer and pentamer PNA building blocks with a single lysine-based side chain at various positions in the building block could proceed efficiently and sequence-specifically. In addition, DNA-templated polymerization also proceeded efficiently and in a sequence-specific manner with pentamer PNA aldehydes containing two or three lysine side chains in a single building block to generate more densely functionalized polymers. To further our understanding of side-chain compatibility and expand the capabilities of this system, we also examined the polymerization efficiencies of 20 pentamer building blocks each containing one of five different side-chain groups and four different side-chain regio- and stereochemistries. Polymerization reactions were efficient for all five different side-chain groups and for three of the four combinations of side-chain regio- and stereochemistries. Differences in the efficiency and initial rate of polymerization correlate with the apparent melting temperature of each building block, which is dependent on side-chain regio- and stereochemistry, but relatively insensitive to side-chain structure among the substrates tested. Our findings represent a significant step towards the evolution of sequence-defined synthetic polymers and also demonstrate that enzyme-free nucleic acid-templated polymerization can occur efficiently using substrates with a wide range of side-chain structures, functionalization positions within each building block, and functionalization densities. PMID:18341334

Total synthesis of TMG-chitotriomycin based on an automated electrochemical assembly of a disaccharide building block.

PubMed

Isoda, Yuta; Sasaki, Norihiko; Kitamura, Kei; Takahashi, Shuji; Manmode, Sujit; Takeda-Okuda, Naoko; Tamura, Jun-Ichi; Nokami, Toshiki; Itoh, Toshiyuki

2017-01-01

The total synthesis of TMG-chitotriomycin using an automated electrochemical synthesizer for the assembly of carbohydrate building blocks is demonstrated. We have successfully prepared a precursor of TMG-chitotriomycin, which is a structurally-pure tetrasaccharide with typical protecting groups, through the methodology of automated electrochemical solution-phase synthesis developed by us. The synthesis of structurally well-defined TMG-chitotriomycin has been accomplished in 10-steps from a disaccharide building block.

Big Questions: The Ultimate Building Blocks of Matter

ScienceCinema

Lincoln, Don

2018-01-16

The Standard Model of particle physics treats quarks and leptons as having no size at all. Quarks are found inside protons and neutrons and the most familiar lepton is the electron. While the best measurements to date support that idea, there is circumstantial evidence that suggests that perhaps the these tiny particles might be composed of even smaller building blocks. This video explains this circumstantial evidence and introduces some very basic ideas of what those building blocks might be.

Building Blocks for Personal Brands

ERIC Educational Resources Information Center

Thomas, Lisa Carlucci

2011-01-01

In this article, the author discusses the four essential building blocks for personal brands: (1) name; (2) message; (3) channels; and (4) bridges. However, outstanding building materials can only take a person so far. The author emphasizes that vision, determination, faith, a sense of humor, and humility are also required.

The fabrication of nanopatterns with Au nanoparticles-embedded micelles via nanoimprint lithography.

PubMed

Lee, Jung-Pil; Kim, Eun-Uk; Koh, Haeng-Deog; Kang, Nam-Goo; Jung, Gun-Young; Lee, Jae-Suk

2009-09-09

We fabricated nanopatterns with Au nanoparticles-embedded micelles (Au-micelles) by self-assembly of block copolymers via nanoimprint lithography. The micelle structure prepared by self-assembled block copolymers was used as a template for the synthesis of Au nanoparticles (Au NPs). Au NPs were synthesized in situ inside the micelles of polystyrene-block-poly(2-vinylpyridine) (PS- b-P2VP). Au-micelles were arranged on the trenches of the polymer template, which was imprinted by nanoimprint lithography. The fabrication of line-type and dot-type nanopatterns was carried out by the combined method. In addition, multilayer nanopatterns of the Au-micelles were also proposed.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jiang, Zhenyu, E-mail: jiangzhenyu1201@hotmail.com, E-mail: jianxu@engr.psu.edu; Liu, Yan; Mo, Chen

In an attempt to suppress the dark current, the barrier layer engineer for solution-processed PbSe colloidal quantum-dot (CQD) photodetectors has been investigated in the present study. It was found that the dark current can be significantly suppressed by implementing two types of carrier blocking layers, namely, hole blocking layer and electron blocking layer, sandwiched in between two active PbSe CQD layers. Meanwhile no adverse impact has been observed for the photo current. Our study suggests that this improvement resides on the transport pathway created via carrier recombination at intermediate layer, which provides wide implications for the suppression of dark currentmore » for infrared photodetectors.« less

Shaping Crystal-Crystal Phase Transitions

NASA Astrophysics Data System (ADS)

Du, Xiyu; van Anders, Greg; Dshemuchadse, Julia; Glotzer, Sharon

Previous computational and experimental studies have shown self-assembled structure depends strongly on building block shape. New synthesis techniques have led to building blocks with reconfigurable shape and it has been demonstrated that building block reconfiguration can induce bulk structural reconfiguration. However, we do not understand systematically how this transition happens as a function of building block shape. Using a recently developed ``digital alchemy'' framework, we study the thermodynamics of shape-driven crystal-crystal transitions. We find examples of shape-driven bulk reconfiguration that are accompanied by first-order phase transitions, and bulk reconfiguration that occurs without any thermodynamic phase transition. Our results suggest that for well-chosen shapes and structures, there exist facile means of bulk reconfiguration, and that shape-driven bulk reconfiguration provides a viable mechanism for developing functional materials.

75 FR 71789 - The Future of Aviation Advisory Committee (FAAC); Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-24

... from 8:45 a.m. to 9:30 a.m. Please arrive early for parking, security clearance, and escort to meeting...-mail registration. There is no facility parking and parking at public parking lots is limited. Car... DOT Headquarters Building. There is no Internet access. Bringing computers into the building requires...

Automate Your Physical Plant Using the Building Block Approach.

ERIC Educational Resources Information Center

Michaelson, Matt

1998-01-01

Illustrates how Mount Saint Vincent University (Halifax), by upgrading the control and monitoring of one building or section of the school at a time, could produce savings in energy and operating costs and improve the environment. Explains a gradual, "building block" approach to facility automation that provides flexibility without a…

Building Numbers from Primes

ERIC Educational Resources Information Center

Burkhart, Jerry

2009-01-01

Prime numbers are often described as the "building blocks" of natural numbers. This article shows how the author and his students took this idea literally by using prime factorizations to build numbers with blocks. In this activity, students explore many concepts of number theory, including the relationship between greatest common factors and…

Influence of the quantum dot geometry on p -shell transitions in differently charged quantum dots

NASA Astrophysics Data System (ADS)

Holtkemper, M.; Reiter, D. E.; Kuhn, T.

2018-02-01

Absorption spectra of neutral, negatively, and positively charged semiconductor quantum dots are studied theoretically. We provide an overview of the main energetic structure around the p -shell transitions, including the influence of nearby nominally dark states. Based on the envelope function approximation, we treat the four-band Luttinger theory as well as the direct and short-range exchange Coulomb interactions within a configuration interaction approach. The quantum dot confinement is approximated by an anisotropic harmonic potential. We present a detailed investigation of state mixing and correlations mediated by the individual interactions. Differences and similarities between the differently charged quantum dots are highlighted. Especially large differences between negatively and positively charged quantum dots become evident. We present a visualization of energetic shifts and state mixtures due to changes in size, in-plane asymmetry, and aspect ratio. Thereby we provide a better understanding of the experimentally hard to access question of quantum dot geometry effects. Our findings show a method to determine the in-plane asymmetry from photoluminescence excitation spectra. Furthermore, we supply basic knowledge for tailoring the strength of certain state mixtures or the energetic order of particular excited states via changes of the shape of the quantum dot. Such knowledge builds the basis to find the optimal QD geometry for possible applications and experiments using excited states.

2. OBLIQUE VIEW LOOKING NORTHWEST FROM 21ST STREET VIADUCT TOWARDS ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

2. OBLIQUE VIEW LOOKING NORTHWEST FROM 21ST STREET VIADUCT TOWARDS 2000 BLOCK OF MORRIS AVENUE WITH HEAVIEST CORNER ON EARTH BUILDINGS (TOP LEFT) AND COMER BUILDING (TOP RIGHT) - Morris Avenue Warehouse District, 2000-2400 blocks of Morris Avenue & 2100-2500 blocks of First Avenue, North, Birmingham, Jefferson County, AL

Automated electrochemical assembly of the protected potential TMG-chitotriomycin precursor based on rational optimization of the carbohydrate building block.

PubMed

Nokami, Toshiki; Isoda, Yuta; Sasaki, Norihiko; Takaiso, Aki; Hayase, Shuichi; Itoh, Toshiyuki; Hayashi, Ryutaro; Shimizu, Akihiro; Yoshida, Jun-ichi

2015-03-20

The anomeric arylthio group and the hydroxyl-protecting groups of thioglycosides were optimized to construct carbohydrate building blocks for automated electrochemical solution-phase synthesis of oligoglucosamines having 1,4-β-glycosidic linkages. The optimization study included density functional theory calculations, measurements of the oxidation potentials, and the trial synthesis of the chitotriose trisaccharide. The automated synthesis of the protected potential N,N,N-trimethyl-d-glucosaminylchitotriomycin precursor was accomplished by using the optimized building block.

Total synthesis of TMG-chitotriomycin based on an automated electrochemical assembly of a disaccharide building block

PubMed Central

Isoda, Yuta; Sasaki, Norihiko; Kitamura, Kei; Takahashi, Shuji; Manmode, Sujit; Takeda-Okuda, Naoko; Tamura, Jun-ichi

2017-01-01

The total synthesis of TMG-chitotriomycin using an automated electrochemical synthesizer for the assembly of carbohydrate building blocks is demonstrated. We have successfully prepared a precursor of TMG-chitotriomycin, which is a structurally-pure tetrasaccharide with typical protecting groups, through the methodology of automated electrochemical solution-phase synthesis developed by us. The synthesis of structurally well-defined TMG-chitotriomycin has been accomplished in 10-steps from a disaccharide building block. PMID:28684973

Strategies for Controlled Placement of Nanoscale Building Blocks

PubMed Central

2007-01-01

The capability of placing individual nanoscale building blocks on exact substrate locations in a controlled manner is one of the key requirements to realize future electronic, optical, and magnetic devices and sensors that are composed of such blocks. This article reviews some important advances in the strategies for controlled placement of nanoscale building blocks. In particular, we will overview template assisted placement that utilizes physical, molecular, or electrostatic templates, DNA-programmed assembly, placement using dielectrophoresis, approaches for non-close-packed assembly of spherical particles, and recent development of focused placement schemes including electrostatic funneling, focused placement via molecular gradient patterns, electrodynamic focusing of charged aerosols, and others. PMID:21794185

Inquiring Minds

Science.gov Websites

and leptons seem to be the fundamental building blocks - but perhaps there is something even smaller properties of the fundamental building blocks of our universe, there are untold mysteries still to solve

Measuring health systems strength and its impact: experiences from the African Health Initiative.

PubMed

Sherr, Kenneth; Fernandes, Quinhas; Kanté, Almamy M; Bawah, Ayaga; Condo, Jeanine; Mutale, Wilbroad

2017-12-21

Health systems are essential platforms for accessible, quality health services, and population health improvements. Global health initiatives have dramatically increased health resources; however, funding to strengthen health systems has not increased commensurately, partially due to concerns about health system complexity and evidence gaps demonstrating health outcome improvements. In 2009, the African Health Initiative of the Doris Duke Charitable Foundation began supporting Population Health Implementation and Training Partnership projects in five sub-Saharan African countries (Ghana, Mozambique, Rwanda, Tanzania, and Zambia) to catalyze significant advances in strengthening health systems. This manuscript reflects on the experience of establishing an evaluation framework to measure health systems strength, and associate measures with health outcomes, as part of this Initiative. Using the World Health Organization's health systems building block framework, the Partnerships present novel approaches to measure health systems building blocks and summarize data across and within building blocks to facilitate analytic procedures. Three Partnerships developed summary measures spanning the building blocks using principal component analysis (Ghana and Tanzania) or the balanced scorecard (Zambia). Other Partnerships developed summary measures to simplify multiple indicators within individual building blocks, including health information systems (Mozambique), and service delivery (Rwanda). At the end of the project intervention period, one to two key informants from each Partnership's leadership team were asked to list - in rank order - the importance of the six building blocks in relation to their intervention. Though there were differences across Partnerships, service delivery and information systems were reported to be the most common focus of interventions, followed by health workforce and leadership and governance. Medical products, vaccines and technologies, and health financing, were the building blocks reported to be of lower focus. The African Health Initiative experience furthers the science of evaluation for health systems strengthening, highlighting areas for further methodological development - including the development of valid, feasible measures sensitive to interventions in multiple contexts (particularly in leadership and governance) and describing interactions across building blocks; in developing summary statistics to facilitate testing intervention effects on health systems and associations with health status; and designing appropriate analytic models for complex, multi-level open health systems.

Systems thinking in practice: the current status of the six WHO building blocks for health system strengthening in three BHOMA intervention districts of Zambia: a baseline qualitative study.

PubMed

Mutale, Wilbroad; Bond, Virginia; Mwanamwenge, Margaret Tembo; Mlewa, Susan; Balabanova, Dina; Spicer, Neil; Ayles, Helen

2013-08-01

The primary bottleneck to achieving the MDGs in low-income countries is health systems that are too fragile to deliver the volume and quality of services to those in need. Strong and effective health systems are increasingly considered a prerequisite to reducing the disease burden and to achieving the health MDGs. Zambia is one of the countries that are lagging behind in achieving millennium development targets. Several barriers have been identified as hindering the progress towards health related millennium development goals. Designing an intervention that addresses these barriers was crucial and so the Better Health Outcomes through Mentorship (BHOMA) project was designed to address the challenges in the Zambia's MOH using a system wide approach. We applied systems thinking approach to describe the baseline status of the Six WHO building blocks for health system strengthening. A qualitative study was conducted looking at the status of the Six WHO building blocks for health systems strengthening in three BHOMA districts. We conducted Focus group discussions with community members and In-depth Interviews with key informants. Data was analyzed using Nvivo version 9. The study showed that building block specific weaknesses had cross cutting effect in other health system building blocks which is an essential element of systems thinking. Challenges noted in service delivery were linked to human resources, medical supplies, information flow, governance and finance building blocks either directly or indirectly. Several barriers were identified as hindering access to health services by the local communities. These included supply side barriers: Shortage of qualified health workers, bad staff attitude, poor relationships between community and health staff, long waiting time, confidentiality and the gender of health workers. Demand side barriers: Long distance to health facility, cost of transport and cultural practices. Participating communities seemed to lack the capacity to hold health workers accountable for the drugs and services. The study has shown that building block specific weaknesses had cross cutting effect in other health system building blocks. These linkages emphasised the need to use system wide approaches in assessing the performance of health system strengthening interventions.

Rapid and annealing-free self-assembly of DNA building blocks for 3D hydrogel chaperoned by cationic comb-type copolymers.

PubMed

Zhang, Zheng; Wu, Yuyang; Yu, Feng; Niu, Chaoqun; Du, Zhi; Chen, Yong; Du, Jie

2017-10-01

The construction and self-assembly of DNA building blocks are the foundation of bottom-up development of three-dimensional DNA nanostructures or hydrogels. However, most self-assembly from DNA components is impeded by the mishybridized intermediates or the thermodynamic instability. To enable rapid production of complicated DNA objects with high yields no need for annealing process, herein different DNA building blocks (Y-shaped, L- and L'-shaped units) were assembled in presence of a cationic comb-type copolymer, poly (L-lysine)-graft-dextran (PLL-g-Dex), under physiological conditions. The results demonstrated that PLL-g-Dex not only significantly promoted the self-assembly of DNA blocks with high efficiency, but also stabilized the assembled multi-level structures especially for promoting the complicated 3D DNA hydrogel formation. This study develops a novel strategy for rapid and high-yield production of DNA hydrogel even derived from instable building blocks at relatively low DNA concentrations, which would endow DNA nanotechnology for more practical applications.

An Approach for On-Board Software Building Blocks Cooperation and Interfaces Definition

NASA Astrophysics Data System (ADS)

Pascucci, Dario; Campolo, Giovanni; Candia, Sante; Lisio, Giovanni

2010-08-01

This paper provides an insight on the Avionic SW architecture developed by Thales Alenia Space Italy (TAS-I) to achieve structuring of the OBSW as a set of self-standing and re-usable building blocks. It is initially described the underlying framework for building blocks cooperation, which is based on ECSSE-70 packets forwarding (for services request to a building block) and standard parameters exchange for data communication. Subsequently it is discussed the high level of flexibility and scalability of the resulting architecture, reporting as example an implementation of the Failure Detection, Isolation and Recovery (FDIR) function which exploits the proposed architecture. The presented approach evolves from avionic SW architecture developed in the scope of the project PRIMA (Mult-Purpose Italian Re-configurable Platform) and has been adopted for the Sentinel-1 Avionic Software (ASW).

HOT CELL BUILDING, TRA632. CONTEXTUAL AERIAL VIEW OF HOT CELL ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

HOT CELL BUILDING, TRA-632. CONTEXTUAL AERIAL VIEW OF HOT CELL BUILDING, IN VIEW AT LEFT, AS YET WITHOUT ROOF. PLUG STORAGE BUILDING LIES BETWEEN IT AND THE SOUTH SIDE OF THE MTR BUILDING AND ITS WING. NOTE CONCRETE DRIVE BETWEEN ROLL-UP DOOR IN MTR BUILDING AND CHARGING FACE OF PLUG STORAGE. REACTOR SERVICES BUILDING (TRA-635) WILL COVER THIS DRIVE AND BUTT UP TO CHARGING FACE. DOTTED LINE IS ON ORIGINAL NEGATIVE. TRA PARKING LOT IN LEFT CORNER OF THE VIEW. CAMERA FACING NORTHWESTERLY. INL NEGATIVE NO. 8274. Unknown Photographer, 7/2/1953 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

15. WEST SIDE OF 1900 BLOCK, PACIFIC AVE. FROM RIGHT; ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

15. WEST SIDE OF 1900 BLOCK, PACIFIC AVE. FROM RIGHT; 1920-22 PACIFIC AVE., WIEGAL COMPANY CANDY FACTORY (1904); 1924-26 PACIFIC AVE., CAMPBELL BUILDING (DAVIS BUILDING) (1890); 1928-30 PACIFIC AVE., REESE-CRANDALL & REDMAN BUILDING, (1890); 1932-36 PACIFIC AVE., MC DONALD & SMITH BUILDING (1890); 1938-48 PACIFIC AVE., F.S. HARMON COMPANY WAREHOUSE (1908), DESIGNED BY CARL AUGUST DARMER. - Union Depot Area Study, Tacoma, Pierce County, WA

Application of soil block without burning process and calcium silicate panels as building wall in mountainous area

NASA Astrophysics Data System (ADS)

Noerwasito, Vincentius Totok; Nasution, Tanti Satriana Rosary

2017-11-01

Utilization of local building materials in a residential location in mountainous area is very important, considering local material as a low-energy building material because of low transport energy. The local building materials used in this study are walls made from soil blocks. The material was made by the surrounding community from compacted soil without burning process. To maximize the potential of soil block to the outdoor temperature in the mountains, it is necessary to add non-local building materials as an insulator from the influence of the outside air. The insulator was calcium silicate panel. The location of the research is Trawas sub-district, Mojokerto regency, which is a mountainous area. The research problem is on applying the composition of local materials and calcium silicate panels that it will be able to meet the requirements as a wall building material and finding to what extent the impact of the wall against indoor temperature. The result from this research was the application of soil block walls insulated by calcium silicate panels in a building model. Besides, because of the utilization of those materials, the building has a specific difference between indoor and outdoor temperature. Thus, this model can be applied in mountainous areas in Indonesia.

How Crossover Speeds up Building Block Assembly in Genetic Algorithms.

PubMed

Sudholt, Dirk

2017-01-01

We reinvestigate a fundamental question: How effective is crossover in genetic algorithms in combining building blocks of good solutions? Although this has been discussed controversially for decades, we are still lacking a rigorous and intuitive answer. We provide such answers for royal road functions and OneMax, where every bit is a building block. For the latter, we show that using crossover makes every ([Formula: see text]+[Formula: see text]) genetic algorithm at least twice as fast as the fastest evolutionary algorithm using only standard bit mutation, up to small-order terms and for moderate [Formula: see text] and [Formula: see text]. Crossover is beneficial because it can capitalize on mutations that have both beneficial and disruptive effects on building blocks: crossover is able to repair the disruptive effects of mutation in later generations. Compared to mutation-based evolutionary algorithms, this makes multibit mutations more useful. Introducing crossover changes the optimal mutation rate on OneMax from [Formula: see text] to [Formula: see text]. This holds both for uniform crossover and k-point crossover. Experiments and statistical tests confirm that our findings apply to a broad class of building block functions.

Silicene Flowers: A Dual Stabilized Silicon Building Block for High-Performance Lithium Battery Anodes.

PubMed

Zhang, Xinghao; Qiu, Xiongying; Kong, Debin; Zhou, Lu; Li, Zihao; Li, Xianglong; Zhi, Linjie

2017-07-25

Nanostructuring is a transformative way to improve the structure stability of high capacity silicon for lithium batteries. Yet, the interface instability issue remains and even propagates in the existing nanostructured silicon building blocks. Here we demonstrate an intrinsically dual stabilized silicon building block, namely silicene flowers, to simultaneously address the structure and interface stability issues. These original Si building blocks as lithium battery anodes exhibit extraordinary combined performance including high gravimetric capacity (2000 mAh g -1 at 800 mA g -1 ), high volumetric capacity (1799 mAh cm -3 ), remarkable rate capability (950 mAh g -1 at 8 A g -1 ), and excellent cycling stability (1100 mA h g -1 at 2000 mA g -1 over 600 cycles). Paired with a conventional cathode, the fabricated full cells deliver extraordinarily high specific energy and energy density (543 Wh kg ca -1 and 1257 Wh L ca -1 , respectively) based on the cathode and anode, which are 152% and 239% of their commercial counterparts using graphite anodes. Coupled with a simple, cost-effective, scalable synthesis approach, this silicon building block offers a horizon for the development of high-performance batteries.

Single molecule magnets from magnetic building blocks

NASA Astrophysics Data System (ADS)

Kroener, W.; Paretzki, A.; Cervetti, C.; Hohloch, S.; Rauschenbach, S.; Kern, K.; Dressel, M.; Bogani, L.; M&üLler, P.

2013-03-01

We provide a basic set of magnetic building blocks that can be rationally assembled, similar to magnetic LEGO bricks, in order to create a huge variety of magnetic behavior. Using rare-earth centers and multipyridine ligands, fine-tuning of intra and intermolecular exchange interaction is demonstrated. We have investigated a series of molecules with monomeric, dimeric and trimeric lanthanide centers using SQUID susceptometry and Hall bar magnetometry. A home-made micro-Hall-probe magnetometer was used to measure magnetic hysteresis loops at mK temperatures and fields up to 17 T. All compounds show hysteresis below blocking temperatures of 3 to 4 K. The correlation of the assembly of the building blocks with the magnetic properties will be discussed.

Embeddable Reconfigurable Neuroprocessors

NASA Technical Reports Server (NTRS)

Daud, Taher; Duong, Tuan; Langenbacher, Harry; Tran, Mua; Thakoor, Anil

1993-01-01

Reconfigurable and cascadable building block neural network chips, fabricated using analog VLSI design tools, are interfaced to a PC. The building block chip designs, the cascadability and the hardware-in-the-loop supervised learning aspects of these chips are described.

77 FR 42484 - Application(s) for Duty-Free Entry of Scientific Instruments

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-19

..., high-temperature metal alloys, evaporated metal films, silicon-germanium quantum dots, soils and... University, Department of Biological Sciences, 202 Life Sciences Building, Baton Rouge, LA 70803-1715...

Tops as building blocks for G 2 manifolds

NASA Astrophysics Data System (ADS)

Braun, Andreas P.

2017-10-01

A large number of examples of compact G 2 manifolds, relevant to supersymmetric compactifications of M-Theory to four dimensions, can be constructed by forming a twisted connected sum of two building blocks times a circle. These building blocks, which are appropriate K3-fibred threefolds, are shown to have a natural and elegant construction in terms of tops, which parallels the construction of Calabi-Yau manifolds via reflexive polytopes. In particular, this enables us to prove combinatorial formulas for the Hodge numbers and other relevant topological data.

Origami-inspired building block and parametric design for mechanical metamaterials

NASA Astrophysics Data System (ADS)

Jiang, Wei; Ma, Hua; Feng, Mingde; Yan, Leilei; Wang, Jiafu; Wang, Jun; Qu, Shaobo

2016-08-01

An origami-based building block of mechanical metamaterials is proposed and explained by introducing a mechanism model based on its geometry. According to our model, this origami mechanism supports response to uniaxial tension that depends on structure parameters. Hence, its mechanical properties can be tunable by adjusting the structure parameters. Experiments for poly lactic acid (PLA) samples were carried out, and the results are in good agreement with those of finite element analysis (FEA). This work may be useful for designing building blocks of mechanical metamaterials or other complex mechanical structures.

Large space erectable structures - building block structures study

NASA Technical Reports Server (NTRS)

Armstrong, W. H.; Skoumal, D. E.; Straayer, J. W.

1977-01-01

A modular planar truss structure and a long slender boom concept identified as building block approaches to construction of large spacecraft configurations are described. The concepts are compatible in weight and volume goals with the Space Transportation System, use standard structural units, and represent high on-orbit productivity in terms of structural area or beam length. Results of structural trade studies involving static and dynamic analyses of a single module and rigid body deployment analyses to assess kinetics and kinematics of automatic deployment of the building block modules are presented.

Probing charge transfer in a novel class of luminescent perovskite-based heterostructures composed of quantum dots bound to RE-activated CaTiO 3 phosphors

DOE PAGES

Crystal S. Lewis; Wong, Stanislaus S.; Liu, Haiqing; ...

2016-01-04

We report on the synthesis and structural characterization of novel semiconducting heterostructures composed of cadmium selenide (CdSe) quantum dots (QDs) attached onto the surfaces of novel high-surface area, porous rare-earth-ion doped alkaline earth titanate micron-scale spherical motifs, i.e. both Eu-doped and Pr-doped CaTiO 3, composed of constituent, component nanoparticles. These unique metal oxide perovskite building blocks were created by a multi-pronged synthetic strategy involving molten salt and hydrothermal protocols. Subsequently, optical characterization of these heterostructures indicated a clear behavioral dependence of charge transfer in these systems upon a number of parameters such as the nature of the dopant, the reactionmore » temperature, and particle size. Specifically, 2.7 nm diameter ligand-functionalized CdSe QDs were anchored onto sub-micron sized CaTiO 3-based spherical assemblies, prepared by molten salt protocols. We found that both the Pr- and Eu-doped CaTiO 3 displayed pronounced PL emissions, with maximum intensities observed using optimized lanthanide concentrations of 0.2 mol% and 6 mol%, respectively. Analogous experiments were performed on Eu-doped BaTiO 3 and SrTiO 3 motifs, but CaTiO 3 still performed as the most effective host material amongst the three perovskite systems tested. Furthermore, the ligand-capped CdSe QD-doped CaTiO 3 heterostructures exhibited effective charge transfer between the two individual constituent nanoscale components, an assertion corroborated by the corresponding quenching of their measured PL signals.« less

Probing the dependence of electron transfer on size and coverage in carbon nanotube-quantum dot heterostructures

DOE PAGES

Wang, Lei; Wong, Stanislaus S.; Han, Jinkyu; ...

2015-11-16

As a model system for understanding charge transfer in novel architectural designs for solar cells, double-walled carbon nanotube (DWNT)–CdSe quantum dot (QD) (QDs with average diameters of 2.3, 3.0, and 4.1 nm) heterostructures have been fabricated. The individual nanoscale building blocks were successfully attached and combined using a hole-trapping thiol linker molecule, i.e., 4-mercaptophenol (MTH), through a facile, noncovalent π–π stacking attachment strategy. Transmission electron microscopy confirmed the attachment of QDs onto the external surfaces of the DWNTs. We herein demonstrate a meaningful and unique combination of near-edge X-ray absorption fine structure (NEXAFS) and Raman spectroscopies bolstered by complementary electricalmore » transport measurements in order to elucidate the synergistic interactions between CdSe QDs and DWNTs, which are facilitated by the bridging MTH molecules that can scavenge photoinduced holes and potentially mediate electron redistribution between the conduction bands in CdSe QDs and the C 2p-derived states of the DWNTs. Specifically, we correlated evidence of charge transfer as manifested by (i) changes in the NEXAFS intensities of π* resonance in the C K-edge and Cd M3-edge spectra, (ii) a perceptible outer tube G-band downshift in frequency in Raman spectra, as well as (iii) alterations in the threshold characteristics present in transport data as a function of CdSe QD deposition onto the DWNT surface. Furthermore, the separate effects of (i) varying QD sizes and (ii) QD coverage densities on the electron transfer were independently studied.« less

Addressable single-spin control in multiple quantum dots coupled in series

NASA Astrophysics Data System (ADS)

Nakajima, Takashi

2015-03-01

Electron spin in semiconductor quantum dots (QDs) is promising building block of quantum computers for its controllability and potential scalability. Recent experiments on GaAs QDs have demonstrated necessary ingredients of universal quantum gate operations: single-spin rotations by electron spin resonance (ESR) which is virtually free from the effect of nuclear spin fluctuation, and pulsed control of two-spin entanglement. The scalability of this architecture, however, has remained to be demonstrated in the real world. In this talk, we will present our recent results on implementing single-spin-based qubits in triple, quadruple, and quintuple QDs based on a series coupled architecture defined by gate electrodes. Deterministic initialization of individual spin states and spin-state readout were performed by the pulse operation of detuning between two neighboring QDs. The spin state was coherently manipulated by ESR, where each spin in different QDs is addressed by the shift of the resonance frequency due to the inhomogeneous magnetic field induced by the micro magnet deposited on top of the QDs. Control of two-spin entanglement was also demonstrated. We will discuss key issues for implementing quantum algorithms based on three or more qubits, including the effect of a nuclear spin bath, single-shot readout fidelity, and tuning of multiple qubit devices. Our approaches to these issues will be also presented. This research is supported by Funding Program for World-Leading Innovative R&D on Science and Technology (FIRST) from JSPS, IARPA project ``Multi-Qubit Coherent Operations'' through Copenhagen University, and Grant-in-Aid for Scientific Research from JSPS.

Tunable Encapsulation Structure of Block Copolymer Coated Single-Walled Carbon Nanotubes in Aqueous Solution

DOE PAGES

Han, Youngkyu; Ahn, Suk-Kyun; Zhang, Zhe; ...

2015-05-15

The nano-sized and shape-tunable molecular building blocks can provide great opportunities for the fabrication of precisely controlled nanostructures. In this work, we have fabricated a molecular building block of single-walled carbon nanotubes (SWNTs) coated by PPO-PEO-PPO block copolymers whose encapsulation structure can be controlled via temperature or addition of small molecules. The structure and optical properties of SWNT-block copolymers have been investigated by small angle neutron scattering (SANS), ultraviolet-visible (UV-vis) spectroscopy, atomic force microscopy (AFM), and molecular dynamics (MD) simulation. The structure of the hydrated block copolymer layer surrounding SWNT can be controlled reversibly by varying temperature as well asmore » by irreversibly adding 5-methylsalicylic acid (5MS). Increasing hydrophobicity of the polymers with temperature and strong tendency of 5MS to interact with both block copolymers and orbitals of the SWNTs are likely to be responsible for the significant structural change of the block copolymer encapsulation layer, from loose corona shell to tightly encapsulating compact shell. These result shows an efficient and simple way to fabricate and manipulate carbon-based nano building blocks in aqueous systems with tunable structure.« less

View of the southwest guard tower, cell blocks seven and ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

View of the southwest guard tower, cell blocks seven and eight, administration building west tower, and Fairmount Avenue, looking from the administration building facing west - Eastern State Penitentiary, 2125 Fairmount Avenue, Philadelphia, Philadelphia County, PA

Lateral deflection contribution to settlement estimates : [summary].

DOT National Transportation Integrated Search

2014-12-01

The Wisconsin Department of Transportation (WisDOT) occasionally constructs : embankments and retaining walls over compressible materials using staged construction. : Staged construction is a technique used to build an embankment or retaining wall in...

Synthesis of most polyene natural product motifs using just 12 building blocks and one coupling reaction.

PubMed

Woerly, Eric M; Roy, Jahnabi; Burke, Martin D

2014-06-01

The inherent modularity of polypeptides, oligonucleotides and oligosaccharides has been harnessed to achieve generalized synthesis platforms. Importantly, like these other targets, most small-molecule natural products are biosynthesized via iterative coupling of bifunctional building blocks. This suggests that many small molecules also possess inherent modularity commensurate with systematic building block-based construction. Supporting this hypothesis, here we report that the polyene motifs found in >75% of all known polyene natural products can be synthesized using just 12 building blocks and one coupling reaction. Using the same general retrosynthetic algorithm and reaction conditions, this platform enabled both the synthesis of a wide range of polyene frameworks that covered all of this natural-product chemical space and the first total syntheses of the polyene natural products asnipyrone B, physarigin A and neurosporaxanthin b-D-glucopyranoside. Collectively, these results suggest the potential for a more generalized approach to making small molecules in the laboratory.

Synthesis of most polyene natural product motifs using just 12 building blocks and one coupling reaction

NASA Astrophysics Data System (ADS)

Woerly, Eric M.; Roy, Jahnabi; Burke, Martin D.

2014-06-01

The inherent modularity of polypeptides, oligonucleotides and oligosaccharides has been harnessed to achieve generalized synthesis platforms. Importantly, like these other targets, most small-molecule natural products are biosynthesized via iterative coupling of bifunctional building blocks. This suggests that many small molecules also possess inherent modularity commensurate with systematic building block-based construction. Supporting this hypothesis, here we report that the polyene motifs found in >75% of all known polyene natural products can be synthesized using just 12 building blocks and one coupling reaction. Using the same general retrosynthetic algorithm and reaction conditions, this platform enabled both the synthesis of a wide range of polyene frameworks that covered all of this natural-product chemical space and the first total syntheses of the polyene natural products asnipyrone B, physarigin A and neurosporaxanthin β-D-glucopyranoside. Collectively, these results suggest the potential for a more generalized approach to making small molecules in the laboratory.

Expanding the biomass derived chemical space

PubMed Central

Brun, Nicolas; Hesemann, Peter

2017-01-01

Biorefinery aims at the conversion of biomass and renewable feedstocks into fuels and platform chemicals, in analogy to conventional oil refinery. In the past years, the scientific community has defined a number of primary building blocks that can be obtained by direct biomass decomposition. However, the large potential of this “renewable chemical space” to contribute to the generation of value added bio-active compounds and materials still remains unexplored. In general, biomass derived building blocks feature a diverse range of chemical functionalities. In order to be integrated into value-added compounds, they require additional functionalization and/or covalent modification thereby generating secondary building blocks. The latter can be thus regarded as functional components of bio-active molecules or materials and represent an expansion of the renewable chemical space. This perspective highlights the most recent developments and opportunities for the synthesis of secondary biomass derived building blocks and their application to the preparation of value added products. PMID:28959397

A VLSI decomposition of the deBruijn graph

NASA Technical Reports Server (NTRS)

Collins, O.; Dolinar, S.; Mceliece, R.; Pollara, F.

1990-01-01

A new Viterbi decoder for convolutional codes with constraint lengths up to 15, called the Big Viterbi Decoder, is under development for the Deep Space Network. It will be demonstrated by decoding data from the Galileo spacecraft, which has a rate 1/4, constraint-length 15 convolutional encoder on board. Here, the mathematical theory underlying the design of the very-large-scale-integrated (VLSI) chips that are being used to build this decoder is explained. The deBruijn graph B sub n describes the topology of a fully parallel, rate 1/v, constraint length n+2 Viterbi decoder, and it is shown that B sub n can be built by appropriately wiring together (i.e., connecting together with extra edges) many isomorphic copies of a fixed graph called a B sub n building block. The efficiency of such a building block is defined as the fraction of the edges in B sub n that are present in the copies of the building block. It is shown, among other things, that for any alpha less than 1, there exists a graph G which is a B sub n building block of efficiency greater than alpha for all sufficiently large n. These results are illustrated by describing a special hierarchical family of deBruijn building blocks, which has led to the design of the gate-array chips being used in the Big Viterbi Decoder.

Method and device for producing a tactile display using an electrorheological fluid

NASA Technical Reports Server (NTRS)

Garner, H. Douglas (Inventor)

1996-01-01

A tactile display device utilizes an electrorheological fluid to activate a plurality of tactile dots. A voltage is selectively produced uniformly across an electrorheological fluid flowing between a common ground electrode and a plurality of conductive dot electrodes, thereby producing an increase in the fluid's viscosity to the extent that fluid flow between the two electrodes is restricted. The flow restriction produces a build-up of electrorheological fluid in a corresponding dot actuator chamber. The resulting pressure increase in the chamber displaces an elastic diaphragm fixed to a display surface to form a lump which can be perceived by the reader as one dot in a Braille character cell. A flow regulation system provides a continually pressurized flow system and provides for free flow of the electrorheological fluid through the plurality of dot actuator chambers when they are not activated. The device is adaptable to printed circuit techniques and can simultaneously display tactile dots representative of a full page of Braille characters stored on a medium such as a tape cassette or to display tactile dots representative of non-Braille data appearing on a computer monitor or contained on another data storage medium. In an alternate embodiment, the elastic diaphragm drives a plurality of spring-loaded pins provided with positive stops to maintain consistent displacements of the pins in both their actuated and nonactuated positions.

Tactile display device using an electrorheological fluid

NASA Technical Reports Server (NTRS)

Garner, H. Douglas (Inventor)

1994-01-01

A tactile display device utilizes an electrorheological fluid to activate a plurality of tactile dots. A voltage is selectively produced uniformly across an electrorheological fluid flowing between a common ground electrode and a plurality of conductive dot electrodes, thereby producing an increase in the fluid's viscosity to the extent that fluid flow between the two electrodes is restricted. The flow restriction produces a build-up of electrorheological fluid in a corresponding dot actuator chamber. The resulting pressure increase in the chamber displaces an elastic diaphragm fixed to a display surface to form a lump which can be perceived by the reader as one dot in a Braille character cell. A flow regulation system provides a continually pressurized flow system and provides for free flow of the electrorheological fluid through the plurality of dot actuator chambers when they are not activated. The device is adaptable to printed circuit techniques and can simultaneously display tactile dots representative of a full page of Braille characters stored on a medium such as a tape cassette or to display tactile dots representative of non-Braille data appearing on a computer monitor or contained on another data storage medium. In an alternate embodiment, the elastic diaphragm drives a plurality of spring-loaded pins provided with positive stops to maintain consistent displacements of the pins in both their actuated and nonactuated positions.

A Working Model of Protein Synthesis Using Lego(TM) Building Blocks.

ERIC Educational Resources Information Center

Templin, Mark A.; Fetters, Marcia K.

2002-01-01

Uses Lego building blocks to improve the effectiveness of teaching about protein synthesis. Provides diagrams and pictures for a 2-3 day student activity. Discusses mRNA, transfer RNA, and a protein synthesis model. (MVL)

Enantiopure heterobimetallic single-chain magnets from the chiral Ru(III) building block.

PubMed

Ru, Jing; Gao, Feng; Wu, Tao; Yao, Min-Xia; Li, Yi-Zhi; Zuo, Jing-Lin

2014-01-21

A pair of one-dimensional enantiomers based on the versatile chiral dicyanoruthenate(III) building block have been synthesized and they are chiral single-chain magnets with the effective spin-reversal barrier of 28.2 K.

Systems thinking in practice: the current status of the six WHO building blocks for health system strengthening in three BHOMA intervention districts of Zambia: a baseline qualitative study

PubMed Central

2013-01-01

Background The primary bottleneck to achieving the MDGs in low-income countries is health systems that are too fragile to deliver the volume and quality of services to those in need. Strong and effective health systems are increasingly considered a prerequisite to reducing the disease burden and to achieving the health MDGs. Zambia is one of the countries that are lagging behind in achieving millennium development targets. Several barriers have been identified as hindering the progress towards health related millennium development goals. Designing an intervention that addresses these barriers was crucial and so the Better Health Outcomes through Mentorship (BHOMA) project was designed to address the challenges in the Zambia’s MOH using a system wide approach. We applied systems thinking approach to describe the baseline status of the Six WHO building blocks for health system strengthening. Methods A qualitative study was conducted looking at the status of the Six WHO building blocks for health systems strengthening in three BHOMA districts. We conducted Focus group discussions with community members and In-depth Interviews with key informants. Data was analyzed using Nvivo version 9. Results The study showed that building block specific weaknesses had cross cutting effect in other health system building blocks which is an essential element of systems thinking. Challenges noted in service delivery were linked to human resources, medical supplies, information flow, governance and finance building blocks either directly or indirectly. Several barriers were identified as hindering access to health services by the local communities. These included supply side barriers: Shortage of qualified health workers, bad staff attitude, poor relationships between community and health staff, long waiting time, confidentiality and the gender of health workers. Demand side barriers: Long distance to health facility, cost of transport and cultural practices. Participating communities seemed to lack the capacity to hold health workers accountable for the drugs and services. Conclusion The study has shown that building block specific weaknesses had cross cutting effect in other health system building blocks. These linkages emphasised the need to use system wide approaches in assessing the performance of health system strengthening interventions. PMID:23902601

In-chip microstructures and photonic devices fabricated by nonlinear laser lithography deep inside silicon

PubMed Central

Makey, Ghaith; Elahi, Parviz; Çolakoğlu, Tahir; Ergeçen, Emre; Yavuz, Özgün; Hübner, René; Borra, Mona Zolfaghari; Pavlov, Ihor; Bek, Alpan; Turan, Raşit; Kesim, Denizhan Koray; Tozburun, Serhat; Ilday, Serim; Ilday, F. Ömer

2017-01-01

Silicon is an excellent material for microelectronics and integrated photonics1–3 with untapped potential for mid-IR optics4. Despite broad recognition of the importance of the third dimension5,6, current lithography methods do not allow fabrication of photonic devices and functional microelements directly inside silicon chips. Even relatively simple curved geometries cannot be realised with techniques like reactive ion etching. Embedded optical elements, like in glass7, electronic devices, and better electronic-photonic integration are lacking8. Here, we demonstrate laser-based fabrication of complex 3D structures deep inside silicon using 1 µm-sized dots and rod-like structures of adjustable length as basic building blocks. The laser-modified Si has a different optical index than unmodified parts, which enables numerous photonic devices. Optionally, these parts are chemically etched to produce desired 3D shapes. We exemplify a plethora of subsurface, i.e., “in-chip” microstructures for microfluidic cooling of chips, vias, MEMS, photovoltaic applications and photonic devices that match or surpass the corresponding state-of-the-art device performances. PMID:28983323

In-chip microstructures and photonic devices fabricated by nonlinear laser lithography deep inside silicon

NASA Astrophysics Data System (ADS)

Tokel, Onur; Turnalı, Ahmet; Makey, Ghaith; Elahi, Parviz; ćolakoǧlu, Tahir; Ergeçen, Emre; Yavuz, Ã.-zgün; Hübner, René; Zolfaghari Borra, Mona; Pavlov, Ihor; Bek, Alpan; Turan, Raşit; Kesim, Denizhan Koray; Tozburun, Serhat; Ilday, Serim; Ilday, F. Ã.-mer

2017-10-01

Silicon is an excellent material for microelectronics and integrated photonics1-3, with untapped potential for mid-infrared optics4. Despite broad recognition of the importance of the third dimension5,6, current lithography methods do not allow the fabrication of photonic devices and functional microelements directly inside silicon chips. Even relatively simple curved geometries cannot be realized with techniques like reactive ion etching. Embedded optical elements7, electronic devices and better electronic-photonic integration are lacking8. Here, we demonstrate laser-based fabrication of complex 3D structures deep inside silicon using 1-µm-sized dots and rod-like structures of adjustable length as basic building blocks. The laser-modified Si has an optical index different to that in unmodified parts, enabling the creation of numerous photonic devices. Optionally, these parts can be chemically etched to produce desired 3D shapes. We exemplify a plethora of subsurface—that is, `in-chip'—microstructures for microfluidic cooling of chips, vias, micro-electro-mechanical systems, photovoltaic applications and photonic devices that match or surpass corresponding state-of-the-art device performances.

Size-tunable Lateral Confinement in Monolayer Semiconductors

DOE PAGES

Wei, Guohua; Czaplewski, David A.; Lenferink, Erik J.; ...

2017-06-12

Three-dimensional confinement allows semiconductor quantum dots to exhibit size-tunable electronic and optical properties that enable a wide range of opto-electronic applications from displays, solar cells and bio-medical imaging to single-electron devices. Additional modalities such as spin and valley properties in monolayer transition metal dichalcogenides provide further degrees of freedom requisite for information processing and spintronics. In nanostructures, however, spatial confinement can cause hybridization that inhibits the robustness of these emergent properties. Here in this paper, we show that laterally-confined excitons in monolayer MoS 2 nanodots can be created through top-down nanopatterning with controlled size tunability. Unlike chemically-exfoliated monolayer nanoparticles, themore » lithographically patterned monolayer semiconductor nanodots down to a radius of 15 nm exhibit the same valley polarization as in a continuous monolayer sheet. The inherited bulk spin and valley properties, the size dependence of excitonic energies, and the ability to fabricate MoS 2 nanostructures using semiconductor-compatible processing suggest that monolayer semiconductor nanodots have potential to be multimodal building blocks of integrated optoelectronics and spintronics systems« less

Nanopatterned carbon films with engineered morphology by direct carbonization of UV-stabilized block copolymer films.

PubMed

Wang, Yong; Liu, Jinquan; Christiansen, Silke; Kim, Dong Ha; Gösele, Ulrich; Steinhart, Martin

2008-11-01

Nanopatterned thin carbon films were prepared by direct and expeditious carbonization of the block copolymer polystyrene- block-poly(2-vinylpyridine) (PS- b-P2VP) without the necessity of slow heating to the process temperature and of addition of further carbon precursors. Carbonaceous films having an ordered "dots-on-film" surface topology were obtained from reverse micelle monolayers. The regular nanoporous morphology of PS- b-P2VP films obtained by subjecting reverse micelle monolayers to swelling-induced surface reconstruction could likewise be transferred to carbon films thus characterized by ordered nanopit arrays. Stabilization of PS- b-P2VP by UV irradiation and the concurrent carbonization of both blocks were key to the conservation of the film topography. The approach reported here may enable the realization of a broad range of nanoscaled architectures for carbonaceous materials using a block copolymer ideally suited as a template because of the pronounced repulsion between its blocks and its capability to form highly ordered microdomain structures.

Highly Ordered Block Copolymer Templates for the Generation of Nanostructured Materials

NASA Astrophysics Data System (ADS)

Bhoje Gowd, E.; Nandan, Bhanu; Bigall, Nadja C.; Eychmuller, Alexander; Stamm, Manfred

2009-03-01

Among many different types of self-assembled materials, block copolymers have attracted immense interest for applications in nanotechnology. Block copolymer thin film can be used as a template for patterning of hard inorganic materials such as metal nanoparticles. In the present work, we demonstrate a new approach to fabricate highly ordered arrays of nanoscopic inorganic dots and wires using switchable block copolymer thin films. Various inorganic nanoparticles from a simple aqueous solution were directly deposited on the surface reconstructed block copolymer templates. The preferential interaction of the nanoparticles with one of the blocks is mainly responsible for the lateral distribution of the nanoparticles in addition to the capillary forces. Subsequent stabilization by UV-irradiation followed by pyrolysis in air at 450 ^oC removes the polymer to produce highly ordered metallic nanostructures. This method is highly versatile as the procedure used here is simple, eco-friendly and provides a facile approach to fabricate a broad range of nanoscaled architectures with tunable lateral spacing.

Trimble Use Case Information : A Presentation to DOT Adjacent Band Compatibility Workshop #2

DOT National Transportation Integrated Search

2014-12-04

Trimble Use Case Overview: Heavy Civil Construction - Planning, Designing, Building and Operating: Enhanced information, decision making and control across the entire project lifecycle, generating benefits including: - Faster Completion - Reduced Fue...

Analysis of public benefits for Pennsylvania rail freight funding

DOT National Transportation Integrated Search

2011-01-04

Building on best practices from other states and Pennsylvanias existing evaluation processes, this project developed an assessment tool to help the Pennsylvania Department of Transportation (PennDOT) analyze the public benefits resulting from the ...

Dendronized Metal Nanoparticles-Self-Organizing Building Blocks for the Design of New Functional Materials

DTIC Science & Technology

2016-04-01

characterization has just started.       The hybrids that we have synthesized are based on plasmonic gold and  silver   nanoparticles  (NPs) but  the concept  is...AFRL-AFOSR-UK-TR-2016-0010 Dendronized metal nanoparticles - self-organizing building blocks for the design of new functional materials Bertrand...2015 4. TITLE AND SUBTITLE Dendronized metal nanoparticles - self-organizing building blocks for the design of new functional materials 5a. CONTRACT

A mixed molecular building block strategy for the design of nested polyhedron metal-organic frameworks.

PubMed

Tian, Dan; Chen, Qiang; Li, Yue; Zhang, Ying-Hui; Chang, Ze; Bu, Xian-He

2014-01-13

A mixed molecular building block (MBB) strategy for the synthesis of double-walled cage-based porous metal-organic frameworks (MOFs) is presented. By means of this method, two isostructural porous MOFs built from unprecedented double-walled metal-organic octahedron were obtained by introducing two size-matching C3 -symmetric molecular building blocks with different rigidities. With their unique framework structures, these MOFs provide, to the best of our knowledge, the first examples of double-walled octahedron-based MOFs. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Three dimensional Origami-based metamaterial

NASA Astrophysics Data System (ADS)

Kamrava, Soroush; Mousanezhad, Davood; Ebrahimi, Hamid; Ghosh, Ranajay; Vaziri, Ashkan; High Performance Materials; Structures Labratory Team

We present a novel cellular metamaterial constructed from Origami building blocks based on Miura-ori fold. The proposed cellular metamaterial exhibits unusual properties some of which stemming from the inherent properties of its Origami building blocks, and others manifesting due to its unique geometrical construction and architecture. These properties include foldability with two fully-folded configurations, auxeticity (i.e., negative Poisson's ratio), bistability, and self-locking of Origami building blocks to construct load-bearing cellular metamaterials. The kinematics and force response of the cellular metamaterial during folding were studied to investigate the underlying mechanisms resulting in its unique properties using analytical modeling and experiments.

PERTS: A Prototyping Environment for Real-Time Systems

NASA Technical Reports Server (NTRS)

Liu, Jane W. S.; Lin, Kwei-Jay; Liu, C. L.

1991-01-01

We discuss an ongoing project to build a Prototyping Environment for Real-Time Systems, called PERTS. PERTS is a unique prototyping environment in that it has (1) tools and performance models for the analysis and evaluation of real-time prototype systems, (2) building blocks for flexible real-time programs and the support system software, (3) basic building blocks of distributed and intelligent real time applications, and (4) an execution environment. PERTS will make the recent and future theoretical advances in real-time system design and engineering readily usable to practitioners. In particular, it will provide an environment for the use and evaluation of new design approaches, for experimentation with alternative system building blocks and for the analysis and performance profiling of prototype real-time systems.

Transportable Payload Operations Control Center reusable software: Building blocks for quality ground data systems

NASA Technical Reports Server (NTRS)

Mahmot, Ron; Koslosky, John T.; Beach, Edward; Schwarz, Barbara

1994-01-01

The Mission Operations Division (MOD) at Goddard Space Flight Center builds Mission Operations Centers which are used by Flight Operations Teams to monitor and control satellites. Reducing system life cycle costs through software reuse has always been a priority of the MOD. The MOD's Transportable Payload Operations Control Center development team established an extensive library of 14 subsystems with over 100,000 delivered source instructions of reusable, generic software components. Nine TPOCC-based control centers to date support 11 satellites and achieved an average software reuse level of more than 75 percent. This paper shares experiences of how the TPOCC building blocks were developed and how building block developer's, mission development teams, and users are all part of the process.

Confinement properties of 2D porous molecular networks on metal surfaces

NASA Astrophysics Data System (ADS)

Müller, Kathrin; Enache, Mihaela; Stöhr, Meike

2016-04-01

Quantum effects that arise from confinement of electronic states have been extensively studied for the surface states of noble metals. Utilizing small artificial structures for confinement allows tailoring of the surface properties and offers unique opportunities for applications. So far, examples of surface state confinement include thin films, artificial nanoscale structures, vacancy and adatom islands, self-assembled 1D chains, vicinal surfaces, quantum dots and quantum corrals. In this review we summarize recent achievements in changing the electronic structure of surfaces by adsorption of nanoporous networks whose design principles are based on the concepts of supramolecular chemistry. Already in 1993, it was shown that quantum corrals made from Fe atoms on a Cu(1 1 1) surface using single atom manipulation with a scanning tunnelling microscope confine the Shockley surface state. However, since the atom manipulation technique for the construction of corral structures is a relatively time consuming process, the fabrication of periodic two-dimensional (2D) corral structures is practically impossible. On the other side, by using molecular self-assembly extended 2D porous structures can be achieved in a parallel process, i.e. all pores are formed at the same time. The molecular building blocks are usually held together by non-covalent interactions like hydrogen bonding, metal coordination or dipolar coupling. Due to the reversibility of the bond formation defect-free and long-range ordered networks can be achieved. However, recently also examples of porous networks formed by covalent coupling on the surface have been reported. By the choice of the molecular building blocks, the dimensions of the network (pore size and pore to pore distance) can be controlled. In this way, the confinement properties of the individual pores can be tuned. In addition, the effect of the confined state on the hosting properties of the pores will be discussed in this review article.

Confinement properties of 2D porous molecular networks on metal surfaces.

PubMed

Müller, Kathrin; Enache, Mihaela; Stöhr, Meike

2016-04-20

Quantum effects that arise from confinement of electronic states have been extensively studied for the surface states of noble metals. Utilizing small artificial structures for confinement allows tailoring of the surface properties and offers unique opportunities for applications. So far, examples of surface state confinement include thin films, artificial nanoscale structures, vacancy and adatom islands, self-assembled 1D chains, vicinal surfaces, quantum dots and quantum corrals. In this review we summarize recent achievements in changing the electronic structure of surfaces by adsorption of nanoporous networks whose design principles are based on the concepts of supramolecular chemistry. Already in 1993, it was shown that quantum corrals made from Fe atoms on a Cu(1 1 1) surface using single atom manipulation with a scanning tunnelling microscope confine the Shockley surface state. However, since the atom manipulation technique for the construction of corral structures is a relatively time consuming process, the fabrication of periodic two-dimensional (2D) corral structures is practically impossible. On the other side, by using molecular self-assembly extended 2D porous structures can be achieved in a parallel process, i.e. all pores are formed at the same time. The molecular building blocks are usually held together by non-covalent interactions like hydrogen bonding, metal coordination or dipolar coupling. Due to the reversibility of the bond formation defect-free and long-range ordered networks can be achieved. However, recently also examples of porous networks formed by covalent coupling on the surface have been reported. By the choice of the molecular building blocks, the dimensions of the network (pore size and pore to pore distance) can be controlled. In this way, the confinement properties of the individual pores can be tuned. In addition, the effect of the confined state on the hosting properties of the pores will be discussed in this review article.

Escape from Mars

NASA Image and Video Library

2017-07-10

This image from NASA's Mars Reconnaissance Orbiter shows one of millions of small (10s of meters in diameter) craters and their ejecta material that dot the Elysium Planitia region of Mars. The small craters were likely formed when high-speed blocks of rock were thrown out by a much larger impact (about 10-kilometers in diameter) and fell back to the ground. Some of these blocks may actually escape Mars, which is how we get samples in the form of meteorites that fall to Earth. Other ejected blocks have insufficient velocity, or the wrong trajectory, to escape the Red Planet. As such, when one of these high-speed blocks impacts the surface, it makes what is called a "secondary" crater. These secondaries can form dense "chains" or "rays," which are radial to the crater that formed them. https://photojournal.jpl.nasa.gov/catalog/PIA21769

Enhanced ultraviolet electroluminescence and spectral narrowing from ZnO quantum dots/GaN heterojunction diodes by using high-k HfO{sub 2} electron blocking layer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mo, Xiaoming; Long, Hao; Wang, Haoning

2014-08-11

We demonstrated the capability of realizing enhanced ZnO-related UV emissions by using the low-cost and solution-processable ZnO quantum dots (QDs) with the help of a high-k HfO{sub 2} electron blocking layer (EBL) for the ZnO QDs/p-GaN light-emitting diodes (LEDs). Full-width at half maximum of the LED devices was greatly decreased from ∼110 to ∼54 nm, and recombinations related to nonradiative centers were significantly suppressed with inserting HfO{sub 2} EBL. The electroluminescence of the ZnO QDs/HfO{sub 2}/p-GaN LEDs demonstrated an interesting spectral narrowing effect with increasing HfO{sub 2} thickness. The Gaussian fitting revealed that the great enhancement of the Zn{sub i}-related emissionmore » at ∼414 nm whereas the deep suppression of the interfacial recombination at ∼477 nm should be the main reason for the spectral narrowing effect.« less

Study on the blocking effect of a quantum-dot TiO2 compact layer in dye-sensitized solar cells with ionic liquid electrolyte under low-intensity illumination

NASA Astrophysics Data System (ADS)

Zhai, Peng; Lee, Hyeonseok; Huang, Yu-Ting; Wei, Tzu-Chien; Feng, Shien-Ping

2016-10-01

In this study, ultrasmall and ultrafine TiO2 quantum dots (QDs) were prepared and used as a high-performance compact layer (CL) in dye-sensitized solar cells (DSCs). We systematically investigated the performance of TiO2 CL under both low-intensity light and indoor fluorescent light illumination and found that the efficiency of DSCs with the insertion of optimal TiO2 QDs-CL was increased up to 18.3% under indoor T5 fluorescent light illumination (7000 lux). We clarified the controversy over the blocking effect of TiO2 CL for the efficiency increment and confirmed that the TiO2 QDs-CL performed significantly better under low-intensity illumination due to the efficient suppression of electron recombination at the FTO/electrolyte interface. We, for the first time, demonstrate this potential for the application of the DSCs with TiO2 QDs-CL in the low-intensity light and indoor fluorescent light illumination.

Optical properties of thin films of zinc oxide quantum dots and polydimethylsiloxane: UV-blocking and the effect of cross-linking.

PubMed

Eita, Mohamed; El Sayed, Ramy; Muhammed, Mamoun

2012-12-01

Thin films of polydimethylsiloxane (PDMS) and ZnO quantum dots (QDs) were built up as multilayers by spin-coating. The films are characterized by a UV-blocking ability that increases with increasing number of bilayers. Photoluminescence (PL) emission spectra of the thin films occur at 522 nm, which is the PL wavelength of the ZnO QDs dispersion, but with a lower intensity and a quantum yield (QY) less than 1% that of the dispersion. Cross-linking has introduced new features to the absorption spectra in that the absorption peak was absent. These changes were attributed to the morphological and structural changes revealed by transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR), respectively. TEM showed that the ZnO particle size in the film increased from 7 (±2.7) nm to 16 (±7.8) upon cross-linking. The FTIR spectra suggest that ZnO QDs are involved in the cross-linking of PDMS and that the surface of the ZnO QDs has been chemically modified. Copyright © 2012 Elsevier Inc. All rights reserved.

ECO-ITS : Intelligent Transportation System Applications to Improve Environmental Performance

DOT National Transportation Integrated Search

2012-05-01

This report describes recent research supported by the US DOTs AERIS program, building upon existing work through developing and improving data collection methods, developing new data fusion techniques to improve estimates, and applying appropriat...

76 FR 76811 - Stakeholders Meeting Regarding Ready Reserve Force (RRF) Ship Manager Contract Program

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-08

... for Cost Saving Methods in Program Management, Ship Costs, Green Initiatives. Limited Scope Ship... registration is recommended. The DOT building at 1200 New Jersey Ave. SE. has security entrance requirements...

Marine Safety Center briefing book

DOT National Transportation Integrated Search

1997-10-30

The U.S. Coast Guard Marine Safety Center was established in 1986 as a consolidation of district Merchant Marine Technical Offices. Our offices are located on the sixth floor of the DOT Headquarters building in Washington, DC. This document provides ...

Hydration effects on the electronic properties of eumelanin building blocks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Assis Oliveira, Leonardo Bruno; Departamento de Física - CEPAE, Universidade Federal de Goiás, 74690-900 Goiânia, GO; Escola de Ciências Exatas e da Computação, Pontifícia Universidade Católica de Goiás, 74605-010 Goiânia, GO

2016-08-28

Theoretical results for the electronic properties of eumelanin building blocks in the gas phase and water are presented. The building blocks presently investigated include the monomeric species DHI (5,6-dihydroxyindole) or hydroquinone (HQ), DHICA (5,6-dihydroxyindole-2-carboxylic acid), indolequinone (IQ), quinone methide (MQ), two covalently bonded dimers [HM ≡ HQ + MQ and IM ≡ IQ + MQ], and two tetramers [HMIM ≡ HQ + IM, IMIM ≡ IM + IM]. The electronic properties in water were determined by carrying out sequential Monte Carlo/time dependent density functional theory calculations. The results illustrate the role played by hydrogen bonding and electrostatic interactions in themore » electronic properties of eumelanin building blocks in a polar environment. In water, the dipole moments of monomeric species are significantly increased ([54–79]%) relative to their gas phase values. Recently, it has been proposed that the observed enhancement of the higher-energy absorption intensity in eumelanin can be explained by excitonic coupling among eumelanin protomolecules [C.-T. Chen et al., Nat. Commun. 5, 3859 (2014)]. Here, we are providing evidence that for DHICA, IQ, and HMIM, the electronic absorption toward the higher-energy end of the spectrum ([180–220] nm) is enhanced by long-range Coulombic interactions with the water environment. It was verified that by superposing the absorption spectra of different eumelanin building blocks corresponding to the monomers, dimers, and tetramers in liquid water, the behaviour of the experimental spectrum, which is characterised by a nearly monotonic decay from the ultraviolet to the infrared, is qualitatively reproduced. This result is in keeping with a “chemical disorder model,” where the broadband absorption of eumelanin pigments is determined by the superposition of the spectra associated with the monomeric and oligomeric building blocks.« less

Hydration effects on the electronic properties of eumelanin building blocks.

PubMed

Assis Oliveira, Leonardo Bruno; L Fonseca, Tertius; Costa Cabral, Benedito J; Coutinho, Kaline; Canuto, Sylvio

2016-08-28

Theoretical results for the electronic properties of eumelanin building blocks in the gas phase and water are presented. The building blocks presently investigated include the monomeric species DHI (5,6-dihydroxyindole) or hydroquinone (HQ), DHICA (5,6-dihydroxyindole-2-carboxylic acid), indolequinone (IQ), quinone methide (MQ), two covalently bonded dimers [HM ≡ HQ + MQ and IM ≡ IQ + MQ], and two tetramers [HMIM ≡ HQ + IM, IMIM ≡ IM + IM]. The electronic properties in water were determined by carrying out sequential Monte Carlo/time dependent density functional theory calculations. The results illustrate the role played by hydrogen bonding and electrostatic interactions in the electronic properties of eumelanin building blocks in a polar environment. In water, the dipole moments of monomeric species are significantly increased ([54-79]%) relative to their gas phase values. Recently, it has been proposed that the observed enhancement of the higher-energy absorption intensity in eumelanin can be explained by excitonic coupling among eumelanin protomolecules [C.-T. Chen et al., Nat. Commun. 5, 3859 (2014)]. Here, we are providing evidence that for DHICA, IQ, and HMIM, the electronic absorption toward the higher-energy end of the spectrum ([180-220] nm) is enhanced by long-range Coulombic interactions with the water environment. It was verified that by superposing the absorption spectra of different eumelanin building blocks corresponding to the monomers, dimers, and tetramers in liquid water, the behaviour of the experimental spectrum, which is characterised by a nearly monotonic decay from the ultraviolet to the infrared, is qualitatively reproduced. This result is in keeping with a "chemical disorder model," where the broadband absorption of eumelanin pigments is determined by the superposition of the spectra associated with the monomeric and oligomeric building blocks.

Hydration effects on the electronic properties of eumelanin building blocks

NASA Astrophysics Data System (ADS)

Assis Oliveira, Leonardo Bruno; L. Fonseca, Tertius; Costa Cabral, Benedito J.; Coutinho, Kaline; Canuto, Sylvio

2016-08-01

Theoretical results for the electronic properties of eumelanin building blocks in the gas phase and water are presented. The building blocks presently investigated include the monomeric species DHI (5,6-dihydroxyindole) or hydroquinone (HQ), DHICA (5,6-dihydroxyindole-2-carboxylic acid), indolequinone (IQ), quinone methide (MQ), two covalently bonded dimers [HM ≡ HQ + MQ and IM ≡ IQ + MQ], and two tetramers [HMIM ≡ HQ + IM, IMIM ≡ IM + IM]. The electronic properties in water were determined by carrying out sequential Monte Carlo/time dependent density functional theory calculations. The results illustrate the role played by hydrogen bonding and electrostatic interactions in the electronic properties of eumelanin building blocks in a polar environment. In water, the dipole moments of monomeric species are significantly increased ([54-79]%) relative to their gas phase values. Recently, it has been proposed that the observed enhancement of the higher-energy absorption intensity in eumelanin can be explained by excitonic coupling among eumelanin protomolecules [C.-T. Chen et al., Nat. Commun. 5, 3859 (2014)]. Here, we are providing evidence that for DHICA, IQ, and HMIM, the electronic absorption toward the higher-energy end of the spectrum ([180-220] nm) is enhanced by long-range Coulombic interactions with the water environment. It was verified that by superposing the absorption spectra of different eumelanin building blocks corresponding to the monomers, dimers, and tetramers in liquid water, the behaviour of the experimental spectrum, which is characterised by a nearly monotonic decay from the ultraviolet to the infrared, is qualitatively reproduced. This result is in keeping with a "chemical disorder model," where the broadband absorption of eumelanin pigments is determined by the superposition of the spectra associated with the monomeric and oligomeric building blocks.

Adults' Arithmetic Builds on Fast and Automatic Processing of Arabic Digits: Evidence from an Audiovisual Matching Paradigm

PubMed Central

Sasanguie, Delphine; Reynvoet, Bert

2014-01-01

Several studies have shown that performance on symbolic number tasks is related to individual differences in arithmetic. However, it is not clear which process is responsible for this association, i.e. fast, automatic processing of symbols per se or access to the underlying non-symbolic representation of the symbols. To dissociate between both options, adult participants performed an audiovisual matching paradigm. Auditory presented number words needed to be matched with either Arabic digits or dot patterns. The results revealed that a distance effect was present in the dots-number word matching task and absent in the digit-number word matching task. Crucially, only performance in the digit task contributed to the variance in arithmetical abilities. This led us to conclude that adults' arithmetic builds on the ability to quickly and automatically process Arabic digits, without the underlying non-symbolic magnitude representation being activated. PMID:24505308

Movement planning reflects skill level and age changes in toddlers

PubMed Central

Chen, Yu-ping; Keen, Rachel; Rosander, Kerstin; von Hofsten, Claes

2010-01-01

Kinematic measures of children’s reaching were found to reflect stable differences in skill level for planning for future actions. Thirty-five toddlers (18–21 months) were engaged in building block towers (precise task) and in placing blocks into an open container (imprecise task). Sixteen children were re-tested on the same tasks a year later. Longer deceleration as the hand approached the block for pickup was found in the tower task compared to the imprecise task, indicating planning for the second movement. More skillful toddlers who could build high towers had a longer deceleration phase when placing blocks on the tower than toddlers who built low towers. Kinematic differences between the groups remained a year later when all children could build high towers. PMID:21077868

Modeling of the whispering gallery mode in microdisk and microgear resonators using a Toeplitz matrix formalism for single-photon source

NASA Astrophysics Data System (ADS)

Attia, Moez; Gueddana, Amor; Chatta, Rihab; Morand, Alain

2013-09-01

The work presented in this paper develops a new formalism to design microdisks and microgears structures. The main objective is to study the optics and geometrics parameters influence on the microdisks and microgears structures resonance behavior. This study is conducted to choice a resonance structure with height quality factor Q to be associated with Quantum dot to form a single photon source. This new method aims to design resonant structures that are simpler and requires less computing performances than FDTD and Floquet Block methods. This formalism is based on simplifying Fourier transformed and using toeplitz matrix writing. This new writing allows designing all kind of resonance structures with any defect and any modification. In other study we have design a quantum dot emitting a photon at 1550 nm of the fundamental mode, but the quantum dot emits other photons at other wavelengths. The focus of the resonant structure and the quantum dot association is the resonance of the photon at 1550 nm and the elimination of all other photons with others energies. The quantum dot studied in [1] is an InAs/GaAs quantum dot, we design an GaAS microdisk and microgear and we compare the quality factor Q of this two structures and we conclude that the microgear is more appropriated to be associate to the quantum dot and increase the probability P1 to obtain a single photon source at 1550 nm and promotes the obtaining of single photon. The performance improving of the resonant structure is able to increase the success of quantum applications such as quantum gates based on single photon source.

Real World of Industrial Chemistry: Ethylene: The Organic Chemical Industry's Most Important Building Block.

ERIC Educational Resources Information Center

Fernelius, W. Conrad, Ed.; And Others

1979-01-01

The value of ethylene, as the organic chemical industry's most important building block, is discussed. The discussion focuses on the source of ethylene, its various forms and functions, and the ways in which the forms are made. (SA)

Two integrator loop quadrature oscillators: A review.

PubMed

Soliman, Ahmed M

2013-01-01

A review of the two integrator loop oscillator circuits providing two quadrature sinusoidal output voltages is given. All the circuits considered employ the minimum number of capacitors namely two except one circuit which uses three capacitors. The circuits considered are classified to four different classes. The first class includes floating capacitors and floating resistors and the active building blocks realizing these circuits are the Op Amp or the OTRA. The second class employs grounded capacitors and includes floating resistors and the active building blocks realizing these circuits are the DCVC or the unity gain cells or the CFOA. The third class employs grounded capacitors and grounded resistors and the active building blocks realizing these circuits are the CCII. The fourth class employs grounded capacitors and no resistors and the active building blocks realizing these circuits are the TA. Transformation methods showing the generation of different classes from each other is given in details and this is one of the main objectives of this paper.

Building Blocks of Psychology: on Remaking the Unkept Promises of Early Schools.

PubMed

Gozli, Davood G; Deng, Wei Sophia

2018-03-01

The appeal and popularity of "building blocks", i.e., simple and dissociable elements of behavior and experience, persists in psychological research. We begin our assessment of this research strategy with an historical review of structuralism (as espoused by E. B. Titchener) and behaviorism (espoused by J. B. Watson and B. F. Skinner), two movements that held the assumption in their attempts to provide a systematic and unified discipline. We point out the ways in which the elementism of the two schools selected, framed, and excluded topics of study. After the historical review, we turn to contemporary literature and highlight the persistence of research into building blocks and the associated framing and exclusions in psychological research. The assumption that complex categories of human psychology can be understood in terms of their elementary components and simplest forms seems indefensible. In specific cases, therefore, reliance on the assumption requires justification. Finally, we review alternative strategies that bypass the commitment to building blocks.

Toward Generalization of Iterative Small Molecule Synthesis

PubMed Central

Lehmann, Jonathan W.; Blair, Daniel J.; Burke, Martin D.

2018-01-01

Small molecules have extensive untapped potential to benefit society, but access to this potential is too often restricted by limitations inherent to the customized approach currently used to synthesize this class of chemical matter. In contrast, the “building block approach”, i.e., generalized iterative assembly of interchangeable parts, has now proven to be a highly efficient and flexible way to construct things ranging all the way from skyscrapers to macromolecules to artificial intelligence algorithms. The structural redundancy found in many small molecules suggests that they possess a similar capacity for generalized building block-based construction. It is also encouraging that many customized iterative synthesis methods have been developed that improve access to specific classes of small molecules. There has also been substantial recent progress toward the iterative assembly of many different types of small molecules, including complex natural products, pharmaceuticals, biological probes, and materials, using common building blocks and coupling chemistry. Collectively, these advances suggest that a generalized building block approach for small molecule synthesis may be within reach. PMID:29696152

Engineering multifunctional protein nanoparticles by in vitro disassembling and reassembling of heterologous building blocks

NASA Astrophysics Data System (ADS)

Unzueta, Ugutz; Serna, Naroa; Sánchez-García, Laura; Roldán, Mónica; Sánchez-Chardi, Alejandro; Mangues, Ramón; Villaverde, Antonio; Vázquez, Esther

2017-12-01

The engineering of protein self-assembling at the nanoscale allows the generation of functional and biocompatible materials, which can be produced by easy biological fabrication. The combination of cationic and histidine-rich stretches in fusion proteins promotes oligomerization as stable protein-only regular nanoparticles that are composed by a moderate number of building blocks. Among other applications, these materials are highly appealing as tools in targeted drug delivery once empowered with peptidic ligands of cell surface receptors. In this context, we have dissected here this simple technological platform regarding the controlled disassembling and reassembling of the composing building blocks. By applying high salt and imidazole in combination, nanoparticles are disassembled in a process that is fully reversible upon removal of the disrupting agents. By taking this approach, we accomplish here the in vitro generation of hybrid nanoparticles formed by heterologous building blocks. This fact demonstrates the capability to generate multifunctional and/or multiparatopic or multispecific materials usable in nanomedical applications.

Ligand-Asymmetric Janus Quantum Dots for Efficient Blue-Quantum Dot Light-Emitting Diodes.

PubMed

Cho, Ikjun; Jung, Heeyoung; Jeong, Byeong Guk; Hahm, Donghyo; Chang, Jun Hyuk; Lee, Taesoo; Char, Kookheon; Lee, Doh C; Lim, Jaehoon; Lee, Changhee; Cho, Jinhan; Bae, Wan Ki

2018-06-19

We present ligand-asymmetric Janus quantum dots (QDs) to improve the device performance of quantum dot light-emitting diodes (QLEDs). Specifically, we devise blue QLEDs incorporating blue QDs with asymmetrically modified ligands, in which the bottom ligand of QDs in contact with ZnO electron-transport layer serves as a robust adhesive layer and an effective electron-blocking layer and the top ligand ensures uniform deposition of organic hole transport layers with enhanced hole injection properties. Suppressed electron overflow by the bottom ligand and stimulated hole injection enabled by the top ligand contribute synergistically to boost the balance of charge injection in blue QDs and therefore the device performance of blue QLEDs. As an ultimate achievement, the blue QLED adopting ligand-asymmetric QDs displays 2-fold enhancement in peak external quantum efficiency (EQE = 3.23%) compared to the case of QDs with native ligands (oleic acid) (peak EQE = 1.49%). The present study demonstrates an integrated strategy to control over the charge injection properties into QDs via ligand engineering that enables enhancement of the device performance of blue QLEDs and thus promises successful realization of white light-emitting devices using QDs.

SU-E-T-87: The Effect of Bleaching Wavelengths on the Regeneration of the Optically Stimulated Luminescence Signal of NanoDot Dosimeters Pre-Exposed to High-Doses.

PubMed

Omotayo, A; Cygler, J; Sawakuchi, G

2012-06-01

To investigate the effect of bleaching wavelengths on the regeneration of optically stimulated luminescence (OSL) signals in Al 2 O 3 :C nanoDot dosimeters pre-exposed to high doses. Regeneration is the increase in the OSL signal during storage of a bleached nanoDot that was previously pre-exposed to a high dose. This phenomenon affects the accuracy of a calibration protocol proposed by Jursinic 2010 (Med. Phys. 37:102) in which pre-exposure of nanoDots to a high-dose was used to minimize changes in the sensitivity of the detector as a function of accumulated dose. Al 2 O 3 :C OSLDs of the type nanoDot were used throughout this study. Readout was performed using the microStar reader. Bleaching of the OSLDs was performed with four 26 W fluorescent light bulbs in two modes: (i) directly under the lamps; and (ii) with the aid of a long-pass optical filter placed over the nanoDots, partially blocking wavelengths below 495 nm. Eighteen nanoDots were pre-exposed to 1 kGy dose. Then the pre-exposed nanoDots were bleached in two sets of 9 to very low residual OSL signals using bleaching modes (i) and (ii) for 12 h and 45 h, respectively. The nanoDots were then stored in dark and readout after various time intervals to monitor the regeneration of the OSL signal. We fitted the regeneration of the OSL signal using a saturation function and obtained rise-time values of 563 h and 630 h, for bleaching modes (i) and (ii), respectively. At the saturation level, the equivalent doses were about 1.18 Gy and 0.38 Gy for modes (i) and (ii), respectively. The regeneration rates of nanoDot OSLDs pre-exposed to high doses depend on the bleaching light wavelength used to reset the detectors. A bleaching source that has a low component of wavelengths below 495 nm can minimize the regeneration of the OSL signal. Natural Sciences and Engineering Research Council of Canada. © 2012 American Association of Physicists in Medicine.

Electrochemical capacitance modulation in an interacting mesoscopic capacitor induced by internal charge transfer

NASA Astrophysics Data System (ADS)

Liu, Wei; He, Jianhong; Guo, Huazhong; Gao, Jie

2018-04-01

We report experiments on the dynamic response of an interacting mesoscopic capacitor consisting of a quantum dot with two confined spin-split levels of the lowest Landau level. In high magnetic fields, states inside the dot are regulated by a mixture of Coulomb interaction and Landau-level quantization, and electrons distribute on two spatially separated regions. Quantum point contact voltage and magnetic field are employed to manipulate the number and distribution of electrons inside the quantum dot. We find that the periodicity of the electrochemical capacitance oscillations is dominated by the charging energy, and their amplitudes, due to internal charge transfer and strong internal capacitive coupling, show rich variations of modulations. Magnetocapacitance displays a sawtoothlike manner and may differ in tooth directions for different voltages, which, we demonstrate, result from a sawtoothlike electrochemical potential change induced by internal charge transfer and field-sensitive electrostatic potential. We further build a charge stability diagram, which, together with all other capacitance properties, is consistently interpreted in terms of a double-dot model. The demonstrated technique is of interest as a tool for fast and sensitive charge state readout of a double-quantum-dot qubit in the gigahertz frequency quantum electronics.

Improving the Power Conversion Efficiency of Carbon Quantum Dot-Sensitized Solar Cells by Growing the Dots on a TiO₂ Photoanode In Situ.

PubMed

Zhang, Quanxin; Zhang, Geping; Sun, Xiaofeng; Yin, Keyang; Li, Hongguang

2017-05-31

Dye-sensitized solar cells (DSSCs) are highly promising since they can potentially solve global energy issues. The development of new photosensitizers is the key to fully realizing perspectives proposed to DSSCs. Being cheap and nontoxic, carbon quantum dots (CQDs) have emerged as attractive candidates for this purpose. However, current methodologies to build up CQD-sensitized solar cells (CQDSCs) result in an imperfect apparatus with extremely low power conversion efficiencies (PCEs). Herein, we present a simple strategy of growing carbon quantum dots (CQDs) onto TiO₂ surfaces in situ. The CQDs/TiO₂ hybridized photoanode was then used to construct solar cell with an improved PCE of 0.87%, which is higher than all of the reported CQDSCs adopting the simple post-adsorption method. This result indicates that an in situ growing strategy has great advantages in terms of optimizing the performance of CQDSCs. In addition, we have also found that the mechanisms dominating the performance of CQDSCs are different from those behind the solar cells using inorganic semiconductor quantum dots (ISQDs) as the photosensitizers, which re-confirms the conclusion that the characteristics of CQDs differ from those of ISQDs.

Micelle-templated, poly(lactic-co-glycolic acid) nanoparticles for hydrophobic drug delivery.

PubMed

Nabar, Gauri M; Mahajan, Kalpesh D; Calhoun, Mark A; Duong, Anthony D; Souva, Matthew S; Xu, Jihong; Czeisler, Catherine; Puduvalli, Vinay K; Otero, José Javier; Wyslouzil, Barbara E; Winter, Jessica O

2018-01-01

Poly(lactic- co -glycolic acid) (PLGA) is widely used for drug delivery because of its biocompatibility, ability to solubilize a wide variety of drugs, and tunable degradation. However, achieving sub-100 nm nanoparticles (NPs), as might be desired for delivery via the enhanced permeability and retention effect, is extremely difficult via typical top-down emulsion approaches. Here, we present a bottom-up synthesis method yielding PLGA/block copolymer hybrids (ie, "PolyDots"), consisting of hydrophobic PLGA chains entrapped within self-assembling poly(styrene- b -ethylene oxide) (PS- b -PEO) micelles. PolyDots exhibit average diameters <50 nm and lower polydispersity than conventional PLGA NPs. Drug encapsulation efficiencies of PolyDots match conventional PLGA NPs (ie, ~30%) and are greater than those obtained from PS- b -PEO micelles (ie, ~7%). Increasing the PLGA:PS- b -PEO weight ratio alters the drug release mechanism from chain relaxation to erosion controlled. PolyDots are taken up by model glioma cells via endocytotic mechanisms within 24 hours, providing a potential means for delivery to cytoplasm. PolyDots can be lyophilized with minimal change in morphology and encapsulant functionality, and can be produced at scale using electrospray. Encapsulation of PLGA within micelles provides a bottom-up route for the synthesis of sub-100 nm PLGA-based nanocarriers with enhanced stability and drug-loading capacity, and tunable drug release, suitable for potential clinical applications.

Building Quality Report Cards for Geriatric Care in The Netherlands: Using Concept Mapping to Identify the Appropriate "Building Blocks" from the Consumer's Perspective

ERIC Educational Resources Information Center

Groenewoud, A. Stef; van Exel, N. Job A.; Berg, Marc; Huijsman, Robbert

2008-01-01

Purpose: This article reports on a study to identify "building blocks" for quality report cards for geriatric care. Its aim is to present (a) the results of the study and (b) the innovative step-by-step approach that was developed to arrive at these results. Design and Methods: We used Concept Mapping/Structured Conceptualization to…

Building blocks for subleading helicity operators

DOE PAGES

Kolodrubetz, Daniel W.; Moult, Ian; Stewart, Iain W.

2016-05-24

On-shell helicity methods provide powerful tools for determining scattering amplitudes, which have a one-to-one correspondence with leading power helicity operators in the Soft-Collinear Effective Theory (SCET) away from singular regions of phase space. We show that helicity based operators are also useful for enumerating power suppressed SCET operators, which encode subleading amplitude information about singular limits. In particular, we present a complete set of scalar helicity building blocks that are valid for constructing operators at any order in the SCET power expansion. In conclusion, we also describe an interesting angular momentum selection rule that restricts how these building blocks canmore » be assembled.« less

Origami-based cellular metamaterial with auxetic, bistable, and self-locking properties

NASA Astrophysics Data System (ADS)

Kamrava, Soroush; Mousanezhad, Davood; Ebrahimi, Hamid; Ghosh, Ranajay; Vaziri, Ashkan

2017-04-01

We present a novel cellular metamaterial constructed from Origami building blocks based on Miura-ori fold. The proposed cellular metamaterial exhibits unusual properties some of which stemming from the inherent properties of its Origami building blocks, and others manifesting due to its unique geometrical construction and architecture. These properties include foldability with two fully-folded configurations, auxeticity (i.e., negative Poisson’s ratio), bistability, and self-locking of Origami building blocks to construct load-bearing cellular metamaterials. The kinematics and force response of the cellular metamaterial during folding were studied to investigate the underlying mechanisms resulting in its unique properties using analytical modeling and experiments.

Origami-based cellular metamaterial with auxetic, bistable, and self-locking properties

PubMed Central

Kamrava, Soroush; Mousanezhad, Davood; Ebrahimi, Hamid; Ghosh, Ranajay; Vaziri, Ashkan

2017-01-01

We present a novel cellular metamaterial constructed from Origami building blocks based on Miura-ori fold. The proposed cellular metamaterial exhibits unusual properties some of which stemming from the inherent properties of its Origami building blocks, and others manifesting due to its unique geometrical construction and architecture. These properties include foldability with two fully-folded configurations, auxeticity (i.e., negative Poisson’s ratio), bistability, and self-locking of Origami building blocks to construct load-bearing cellular metamaterials. The kinematics and force response of the cellular metamaterial during folding were studied to investigate the underlying mechanisms resulting in its unique properties using analytical modeling and experiments. PMID:28387345

Rapid formation of complexity in the total synthesis of natural products enabled by oxabicyclo[2.2.1]heptene building blocks.

PubMed

Schindler, Corinna S; Carreira, Erick M

2009-11-01

This critical review showcases examples of rapid formation of complexity in total syntheses starting from 7-oxabicyclo[2.2.1]hept-5-ene derivatives. An overview of methods allowing synthetic access to these building blocks is provided and their application in recently developed synthetic transformations to structurally complex systems is illustrated. In addition, the facile access to a novel oxabicyclo[2.2.1]heptene derived building block is presented which significantly enlarges the possibilities of previously known chemical transformations and is highlighted in the enantioselective route to the core of the banyaside and suomilide natural products (107 references).

Recent advances in synthesis of bacterial rare sugar building blocks and their applications.

PubMed

Emmadi, Madhu; Kulkarni, Suvarn S

2014-07-01

Covering: 1964 to 2013. Bacteria have unusual glycans on their surfaces which distinguish them from the host cells. These unique structures offer avenues for targeting bacteria with specific therapeutics and vaccine. However, these rare sugars are not accessible in acceptable purity and amounts by isolation from natural sources. Thus, procurement of orthogonally protected rare sugar building blocks through efficient chemical synthesis is regarded as a crucial step towards the development of glycoconjugate vaccines. This Highlight focuses on recent advances in the synthesis of the bacterial deoxy amino hexopyranoside building blocks and their application in constructing various biologically important bacterial O-glycans.

Ae2Sb2X4F2 (Ae = Sr, Ba): new members of the homologous series Ae2M(1+n)X(3+n)F2 designed from rock salt and fluorite 2D building blocks.

PubMed

Kabbour, Houria; Cario, Laurent

2006-03-20

We have designed new compounds within the homologous series Ae2F2M(1+n)X(3+n) (Ae = Sr, Ba; M = main group metal; n = integer) built up from the stacking of 2D building blocks of rock salt and fluorite types. By incrementally increasing the size of the rock salt 2D building blocks, we have obtained two new n = 1 members of this homologous series, namely, Sr2F2Sb2Se4 and Ba2F2Sb2Se4. We then succeeded in synthesizing these compounds using a high-temperature ceramic method. The structure refinements from the powder or single-crystal X-ray diffraction data confirmed presence of the expected alternating stacking of fluorite [Ae2F2] (Ae = Sr, Ba) and rock salt [Sb2Se4] 2D building blocks. However the Ba derivative shows a strong distortion of the [Sb2Se4] block and a concomitant change of the Sb atom coordination likely related to the lone-pair activity.

Long-wavelength infrared (LWIR) quantum-dot infrared photodetector (QDIP) focal plane array

NASA Astrophysics Data System (ADS)

Gunapala, S. D.; Bandara, S. V.; Hill, C. J.; Ting, D. Z.; Liu, J. K.; Rafol, S. B.; Blazejewski, E. R.; Mumolo, J. M.; Keo, S. A.; Krishna, S.; Chang, Y. C.; Shott, C. A.

2006-05-01

We have exploited the artificial atomlike properties of epitaxially self-assembled quantum dots for the development of high operating temperature long wavelength infrared (LWIR) focal plane arrays. Quantum dots are nanometer-scale islands that form spontaneously on a semiconductor substrate due to lattice mismatch. QDIPs are expected to outperform quantum well infrared detectors (QWIPs) and are expected to offer significant advantages over II-VI material based focal plane arrays. QDIPs are fabricated using robust wide bandgap III-V materials which are well suited to the production of highly uniform LWIR arrays. We have used molecular beam epitaxy (MBE) technology to grow multi-layer LWIR quantum dot structures based on the InAs/InGaAs/GaAs material system. JPL is building on its significant QWIP experience and is basically building a Dot-in-the-Well (DWELL) device design by embedding InAs quantum dots in a QWIP structure. This hybrid quantum dot/quantum well device offers additional control in wavelength tuning via control of dot-size and/or quantum well sizes. In addition the quantum wells can trap electrons and aide in ground state refilling. Recent measurements have shown a 10 times higher photoconductive gain than the typical QWIP device, which indirectly confirms the lower relaxation rate of excited electrons (photon bottleneck) in QDIPs. Subsequent material and device improvements have demonstrated an absorption quantum efficiency (QE) of ~ 3%. Dot-in-the-well (DWELL) QDIPs were also experimentally shown to absorb both 45o and normally incident light. Thus we have employed a reflection grating structure to further enhance the quantum efficiency. JPL has demonstrated wavelength control by progressively growing material and fabricating devices structures that have continuously increased in LWIR response. The most recent devices exhibit peak responsivity out to 8.1 microns. Peak detectivity of the 8.1μm devices has reached ~ 1 x 1010 Jones at 77 K. Furthermore, we have fabricated the first long-wavelength 640x512 pixels QDIP focal plane array. This QDIP focal plane array has produced excellent infrared imagery with noise equivalent temperature difference of 40 mK at 60K operating temperature. In addition, we have managed to increase the quantum efficiency of these devices from 0.1% (according to the data published in literature) to 20% in discrete devices. This is a factor of 200 increase in quantum efficiency. With these excellent results, for the first time QDIP performance has surpassed the QWIP performance. Our goal is to operate these long-wavelength detectors at much higher operating temperature than 77K, which can be passively achieved in space. This will be a huge leap in high performance infrared detectors specifically applicable to space science instruments.

Long-Wavelength Infrared (LWIR) Quantum Dot Infrared Photodetector (QDIP) Focal Plane Array

NASA Technical Reports Server (NTRS)

Gunapala, Sarath D.; Bandara, S. V.; Liu, J. K.; Hill, C. J.; Rafol, S. B.; Mumolo, J. M.; Shott, C. A.

2006-01-01

We have exploited the artificial atomlike properties of epitaxially self-assembled quantum dots for the development of high operating temperature long wavelength infrared (LWIR) focal plane arrays. Quantum dots are nanometer-scale islands that form spontaneously on a semiconductor substrate due to lattice mismatch. QDIPs are expected to outperform quantum well infrared detectors (QWIPs) and are expected to offer significant advantages over II-VI material based focal plane arrays. QDIPs are fabricated using robust wide bandgap III-V materials which are well suited to the production of highly uniform LWIR arrays. We have used molecular beam epitaxy (MBE) technology to grow multi-layer LWIR quantum dot structures based on the InAs/InGaAs/GaAs material system. JPL is building on its significant QWIP experience and is basically building a Dot-in-the-Well (DWELL) device design by embedding InAs quantum dots in a QWIP structure. This hybrid quantum dot/quantum well device offers additional control in wavelength tuning via control of dot-size and/or quantum well sizes. In addition the quantum wells can trap electrons and aide in ground state refilling. Recent measurements have shown a 10 times higher photoconductive gain than the typical QWIP device, which indirectly confirms the lower relaxation rate of excited electrons (photon bottleneck) in QDPs. Subsequent material and device improvements have demonstrated an absorption quantum efficiency (QE) of approx. 3%. Dot-in-the-well (DWELL) QDIPs were also experimentally shown to absorb both 45 deg. and normally incident light. Thus we have employed a reflection grating structure to further enhance the quantum efficiency. JPL has demonstrated wavelength control by progressively growing material and fabricating devices structures that have continuously increased in LWIR response. The most recent devices exhibit peak responsivity out to 8.1 microns. Peak detectivity of the 8.1 micrometer devices has reached approx. 1 x 10(exp 10) Jones at 77 K. Furthermore, we have fabricated the first long-wavelength 640x512 pixels QDP focal plane array. This QDIP focal plane may has produced excellent infrared imagery with noise equivalent temperature difference of 40 mK at 60K operating temperature. In addition, we have managed to increase the quantum efficiency of these devices from 0.1% (according to the data published in literature) to 20% in discrete devices. This is a factor of 200 increase in quantum efficiency. With these excellent results, for the first time QDIP performance has surpassed the QWIP performance. Our goal is to operate these long-wavelength detectors at much higher operating temperature than 77K which can be passively achieved in space. This will be a huge leap in high performance infrared detectors specifically applicable to space science instruments.

Total synthesis of a CD-ring: side-chain building block for preparing 17-epi-calcitriol derivatives from the Hajos-Parrish dione.

PubMed

Michalak, Karol; Wicha, Jerzy

2011-08-19

An efficient synthesis of the key building block for 17-epi-calctriol from the Hajos-Parrish dione involving a sequence of diastereoselective transformation of the azulene core and the side-chain construction is presented.

78 FR 30390 - Applications Delayed More Than 180 Days

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-22

... DEPARTMENT OF TRANSPORTATION Pipeline and Hazardous Materials Safety Administration Applications Delayed More Than 180 Days AGENCY: Pipeline and Hazardous Materials Safety Administration (PHMSA), DOT..., Pipeline and Hazardous Materials Safety Administration, U.S. Department of Transportation, East Building...

High-rate, roll-to-roll nanomanufacturing of flexible systems

NASA Astrophysics Data System (ADS)

Cooper, Khershed P.; Wachter, Ralph F.

2012-10-01

Since the National Nanotechnology Initiative was first announced in 2000, nanotechnology has developed an impressive catalog of nano-scale structures with building-blocks such as nanoparticles, nanotubes, nanorods, nanopillars, and quantum dots. Similarly, there are accompanying materials processes such as, atomic layer deposition, pulsed layer deposition, nanoprinting, nanoimprinting, transfer printing, nanolithography and nanopatterning. One of the challenges of nanomanufacturing is scaling up these processes reliably and affordably. Roll-to-roll manufacturing is a means for scaling up, for increasing throughput. It is high-speed production using a continuous, moving platform such as a web or a flexible substrate. The adoption of roll-to-roll to nanomanufacturing is novel. The goal is to build structures and devices with nano-scale features and specific functionality. The substrate could be a polymer, metal foil, silk, cloth or paper. The materials to build the structures and multi-level devices could be organic, inorganic or biological. Processing could be solution-based, e.g., ink-jet printing, or vacuum-based, e.g., chemical vapor deposition. Products could be electronics, optoelectronics, membranes, catalysts, microfluidics, lab-on-film, filters, etc. By this means, processing of large and conformal areas is achievable. High-throughput translates into low cost, which is the attraction of roll-to-roll nanomanufacturing. There are technical challenges requiring fundamental scientific advances in materials and process development and in manufacturing and system-integration where achieving nano-scale feature size, resolution and accuracy at high speeds can be major hurdles. We will give an overview of roll-to-roll nanomanufacturing with emphasis on the need to understand the material, process and system complexities, the need for instrumentation, measurement, and process control and describe the concept of cyber-enabled nanomanufacturing for reliable and predictable production.

Multiresonant Composite Optical Nanoantennas by Out-of-plane Plasmonic Engineering.

PubMed

Song, Junyeob; Zhou, Wei

2018-06-27

Optical nanoantennas can concentrate light and enhance light-matter interactions in subwavelength domain, which is useful for photodetection, light emission, optical biosensing, and spectroscopy. However, conventional optical nanoantennas operating at a single wavelength band are not suitable for multiband applications. Here, we propose and exploit an out-of-plane plasmonic engineering strategy to design and create composite optical nanoantennas that can support multiple nanolocalized modes at different resonant wavelengths. These multiresonant composite nanoantennas are composed of vertically stacked building blocks of metal-insulator-metal loop nanoantennas. Studies of multiresonant composite nanoantennas demonstrate that the number of supported modes depends on the number of vertically stacked building blocks and the resonant wavelengths of individual modes are tunable by controlling the out-of-plane geometries of their building blocks. In addition, numerical studies show that the resonant wavelengths of individual modes in composite nanoantennas can deviate from the optical response of building blocks due to hybridization of magnetic modes in neighboring building blocks. Using Au nanohole arrays as deposition masks to fabricate arrays of multilayered composite nanoantennas, we experimentally demonstrate their multiresonant optical properties in good agreement with theory predictions. These studies show that out-of-plane engineered multiresonant composite nanoantennas can provide new opportunities for fundamental nanophotonics research and practical applications involving optical multiband operations, such as multiphoton process, broadband solar energy conversion, and wavelength-multiplexed optical system.

Branching patterns in leaf starches from Arabidopsis mutants deficient in diverse starch synthases.

PubMed

Zhu, Fan; Bertoft, Eric; Szydlowski, Nicolas; d'Hulst, Christophe; Seetharaman, Koushik

2015-01-12

This is the first report on the cluster structure of transitory starch from Arabidopsis leaves. In addition to wild type, the molecular structures of leaf starch from mutants deficient in starch synthases (SS) including single enzyme mutants ss1-, ss2-, or ss3-, and also double mutants ss1-ss2- and ss1-ss3- were characterized. The mutations resulted in increased amylose content. Clusters from whole starch were isolated by partial hydrolysis using α-amylase of Bacillus amyloliquefaciens. The clusters were then further hydrolyzed with concentrated α-amylase of B. amyloliquefaciens to produce building blocks (α-limit dextrins). Structures of the clusters and their building blocks were characterized by chromatography of samples before and after debranching treatment. While the mutations increased the size of clusters, the reasons were different as reflected by the composition of their unit chains and building blocks. In general, all mutants contained more of a-chains that preferentially increased the number of small building blocks with only two chains. The clusters of the double mutant ss1-ss3- were very large and possessed also more of large building blocks with four or more chains. The results from transitory starch are compared with those from agriculturally important crops in the context that to what extent the Arabidopsis can be a true biotechnological reflection for starch modifications through genetic means. Copyright © 2014 Elsevier Ltd. All rights reserved.

Precise Two-Photon Photodynamic Therapy using an Efficient Photosensitizer with Aggregation-Induced Emission Characteristics.

PubMed

Gu, Bobo; Wu, Wenbo; Xu, Gaixia; Feng, Guangxue; Yin, Feng; Chong, Peter Han Joo; Qu, Junle; Yong, Ken-Tye; Liu, Bin

2017-07-01

Two-photon photodynamic therapy (PDT) is able to offer precise 3D manipulation of treatment volumes, providing a target level that is unattainable with current therapeutic techniques. The advancement of this technique is greatly hampered by the availability of photosensitizers with large two-photon absorption (TPA) cross section, high reactive-oxygen-species (ROS) generation efficiency, and bright two-photon fluorescence. Here, an effective photosensitizer with aggregation-induced emission (AIE) characteristics is synthesized, characterized, and encapsulated into an amphiphilic block copolymer to form organic dots for two-photon PDT applications. The AIE dots possess large TPA cross section, high ROS generation efficiency, and excellent photostability and biocompatibility, which overcomes the limitations of many conventional two-photon photosensitizers. Outstanding therapeutic performance of the AIE dots in two-photon PDT is demonstrated using in vitro cancer cell ablation and in vivo brain-blood-vessel closure as examples. This shows therapy precision up to 5 µm under two-photon excitation. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Roles of thioredoxin in nitric oxide-dependent preconditioning-induced tolerance against MPTP neurotoxin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chiueh, C.C.; Andoh, Tsugunobu; Chock, P. Boon

2005-09-01

Hormesis, a stress tolerance, can be induced by ischemic preconditioning stress. In addition to preconditioning, it may be induced by other means, such as gas anesthetics. Preconditioning mechanisms, which may be mediated by reprogramming survival genes and proteins, are obscure. A known neurotoxicant, 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), causes less neurotoxicity in the mice that are preconditioned. Pharmacological evidences suggest that the signaling pathway of {center_dot}NO-cGMP-PKG (protein kinase G) may mediate preconditioning phenomenon. We developed a human SH-SY5Y cell model for investigating {sup {center_dot}}NO-mediated signaling pathway, gene regulation, and protein expression following a sublethal preconditioning stress caused by a brief 2-h serum deprivation.more » Preconditioned human SH-SY5Y cells are more resistant against severe oxidative stress and apoptosis caused by lethal serum deprivation and 1-mehtyl-4-phenylpyridinium (MPP{sup +}). Both sublethal and lethal oxidative stress caused by serum withdrawal increased neuronal nitric oxide synthase (nNOS/NOS1) expression and {sup {center_dot}}NO levels to a similar extent. In addition to free radical scavengers, inhibition of nNOS, guanylyl cyclase, and PKG blocks hormesis induced by preconditioning. S-nitrosothiols and 6-Br-cGMP produce a cytoprotection mimicking the action of preconditioning tolerance. There are two distinct cGMP-mediated survival pathways: (i) the up-regulation of a redox protein thioredoxin (Trx) for elevating mitochondrial levels of antioxidant protein Mn superoxide dismutase (MnSOD) and antiapoptotic protein Bcl-2, and (ii) the activation of mitochondrial ATP-sensitive potassium channels [K(ATP)]. Preconditioning induction of Trx increased tolerance against MPP{sup +}, which was blocked by Trx mRNA antisense oligonucleotide and Trx reductase inhibitor. It is concluded that Trx plays a pivotal role in {sup {center_dot}}NO-dependent preconditioning hormesis against MPTP/MPP{sup +}.« less

Alq3 nanorods: promising building blocks for optical devices.

PubMed

Chen, Wei; Peng, Qing; Li, Yadong

2008-07-17

Monodisperse Alq3 nanorods with hexagonal-prism-like morphology are produced via a facile, emulsion based synthesis route. The photoluminescence of individual nanorods differs from the bulk material. These nanorods are promising building blocks for novel optical devices. Copyright © 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Long-range energy transfer in self-assembled quantum dot-DNA cascades

NASA Astrophysics Data System (ADS)

Goodman, Samuel M.; Siu, Albert; Singh, Vivek; Nagpal, Prashant

2015-11-01

The size-dependent energy bandgaps of semiconductor nanocrystals or quantum dots (QDs) can be utilized in converting broadband incident radiation efficiently into electric current by cascade energy transfer (ET) between layers of different sized quantum dots, followed by charge dissociation and transport in the bottom layer. Self-assembling such cascade structures with angstrom-scale spatial precision is important for building realistic devices, and DNA-based QD self-assembly can provide an important alternative. Here we show long-range Dexter energy transfer in QD-DNA self-assembled single constructs and ensemble devices. Using photoluminescence, scanning tunneling spectroscopy, current-sensing AFM measurements in single QD-DNA cascade constructs, and temperature-dependent ensemble devices using TiO2 nanotubes, we show that Dexter energy transfer, likely mediated by the exciton-shelves formed in these QD-DNA self-assembled structures, can be used for efficient transport of energy across QD-DNA thin films.The size-dependent energy bandgaps of semiconductor nanocrystals or quantum dots (QDs) can be utilized in converting broadband incident radiation efficiently into electric current by cascade energy transfer (ET) between layers of different sized quantum dots, followed by charge dissociation and transport in the bottom layer. Self-assembling such cascade structures with angstrom-scale spatial precision is important for building realistic devices, and DNA-based QD self-assembly can provide an important alternative. Here we show long-range Dexter energy transfer in QD-DNA self-assembled single constructs and ensemble devices. Using photoluminescence, scanning tunneling spectroscopy, current-sensing AFM measurements in single QD-DNA cascade constructs, and temperature-dependent ensemble devices using TiO2 nanotubes, we show that Dexter energy transfer, likely mediated by the exciton-shelves formed in these QD-DNA self-assembled structures, can be used for efficient transport of energy across QD-DNA thin films. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr04778a

Forecasting Maintenance Shortcomings of a Planned Equipment Density Listing in Support of Expeditionary Missions

DTIC Science & Technology

2017-06-01

importantly, it examines the methodology used to build the class IX block embarked on ship prior to deployment. The class IX block is defined as a repository...compared to historical data to evaluate model and simulation outputs. This thesis provides recommendations on improving the methodology implemented in...improving the level of organic support available to deployed units. More importantly, it examines the methodology used to build the class IX block

π-Extended Isoindigo-Based Derivative: A Promising Electron-Deficient Building Block for Polymer Semiconductors.

PubMed

Xu, Long; Zhao, Zhiyuan; Xiao, Mingchao; Yang, Jie; Xiao, Jian; Yi, Zhengran; Wang, Shuai; Liu, Yunqi

2017-11-22

The exploration of novel electron-deficient building blocks is a key task for developing high-performance polymer semiconductors in organic thin-film transistors. In view of the situation of the lack of strong electron-deficient building blocks, we designed two novel π-extended isoindigo-based electron-deficient building blocks, IVI and F 4 IVI. Owing to the strong electron-deficient nature and the extended π-conjugated system of the two acceptor units, their copolymers, PIVI2T and PF 4 IVI2T, containing 2,2'-bithiophene donor units, are endowed with deep-lying highest occupied molecular orbital (HOMO)/lowest unoccupied molecular orbital (LUMO) energy levels and strong intermolecular interactions. In comparison to PIVI2T, the fluorinated PF 4 IVI2T exhibits stronger intra- and intermolecular interactions, lower HOMO/LUMO energy levels up to -5.74/-4.17 eV, and more ordered molecular packing with a smaller π-π stacking distance of up to 3.53 Å, resulting in an excellent ambipolar transporting behavior and a promising application in logic circuits for PF 4 IVI2T in ambient with hole and electron mobilities of up to 1.03 and 1.82 cm 2 V -1 s -1 , respectively. The results reveal that F 4 IVI is a promising and strong electron-deficient building unit to construct high-performance semiconducting polymers, which provides an insight into the structure-property relationships for the exploration and molecular engineering of excellent electron-deficient building blocks in the field of organic electronics.

Letter of intent for KM3NeT 2.0

NASA Astrophysics Data System (ADS)

Adrián-Martínez, S.; Ageron, M.; Aharonian, F.; Aiello, S.; Albert, A.; Ameli, F.; Anassontzis, E.; Andre, M.; Androulakis, G.; Anghinolfi, M.; Anton, G.; Ardid, M.; Avgitas, T.; Barbarino, G.; Barbarito, E.; Baret, B.; Barrios-Martí, J.; Belhorma, B.; Belias, A.; Berbee, E.; van den Berg, A.; Bertin, V.; Beurthey, S.; van Beveren, V.; Beverini, N.; Biagi, S.; Biagioni, A.; Billault, M.; Bondì, M.; Bormuth, R.; Bouhadef, B.; Bourlis, G.; Bourret, S.; Boutonnet, C.; Bouwhuis, M.; Bozza, C.; Bruijn, R.; Brunner, J.; Buis, E.; Busto, J.; Cacopardo, G.; Caillat, L.; Calamai, M.; Calvo, D.; Capone, A.; Caramete, L.; Cecchini, S.; Celli, S.; Champion, C.; Cherkaoui El Moursli, R.; Cherubini, S.; Chiarusi, T.; Circella, M.; Classen, L.; Cocimano, R.; Coelho, J. A. B.; Coleiro, A.; Colonges, S.; Coniglione, R.; Cordelli, M.; Cosquer, A.; Coyle, P.; Creusot, A.; Cuttone, G.; D'Amico, A.; De Bonis, G.; De Rosa, G.; De Sio, C.; Di Capua, F.; Di Palma, I.; Díaz García, A. F.; Distefano, C.; Donzaud, C.; Dornic, D.; Dorosti-Hasankiadeh, Q.; Drakopoulou, E.; Drouhin, D.; Drury, L.; Durocher, M.; Eberl, T.; Eichie, S.; van Eijk, D.; El Bojaddaini, I.; El Khayati, N.; Elsaesser, D.; Enzenhöfer, A.; Fassi, F.; Favali, P.; Fermani, P.; Ferrara, G.; Filippidis, C.; Frascadore, G.; Fusco, L. A.; Gal, T.; Galatà, S.; Garufi, F.; Gay, P.; Gebyehu, M.; Giordano, V.; Gizani, N.; Gracia, R.; Graf, K.; Grégoire, T.; Grella, G.; Habel, R.; Hallmann, S.; van Haren, H.; Harissopulos, S.; Heid, T.; Heijboer, A.; Heine, E.; Henry, S.; Hernández-Rey, J. J.; Hevinga, M.; Hofestädt, J.; Hugon, C. M. F.; Illuminati, G.; James, C. W.; Jansweijer, P.; Jongen, M.; de Jong, M.; Kadler, M.; Kalekin, O.; Kappes, A.; Katz, U. F.; Keller, P.; Kieft, G.; Kießling, D.; Koffeman, E. N.; Kooijman, P.; Kouchner, A.; Kulikovskiy, V.; Lahmann, R.; Lamare, P.; Leisos, A.; Leonora, E.; Clark, M. Lindsey; Liolios, A.; Llorens Alvarez, C. D.; Lo Presti, D.; Löhner, H.; Lonardo, A.; Lotze, M.; Loucatos, S.; Maccioni, E.; Mannheim, K.; Margiotta, A.; Marinelli, A.; Mariş, O.; Markou, C.; Martínez-Mora, J. A.; Martini, A.; Mele, R.; Melis, K. W.; Michael, T.; Migliozzi, P.; Migneco, E.; Mijakowski, P.; Miraglia, A.; Mollo, C. M.; Mongelli, M.; Morganti, M.; Moussa, A.; Musico, P.; Musumeci, M.; Navas, S.; Nicolau, C. A.; Olcina, I.; Olivetto, C.; Orlando, A.; Papaikonomou, A.; Papaleo, R.; Păvălaş, G. E.; Peek, H.; Pellegrino, C.; Perrina, C.; Pfutzner, M.; Piattelli, P.; Pikounis, K.; Poma, G. E.; Popa, V.; Pradier, T.; Pratolongo, F.; Pühlhofer, G.; Pulvirenti, S.; Quinn, L.; Racca, C.; Raffaelli, F.; Randazzo, N.; Rapidis, P.; Razis, P.; Real, D.; Resvanis, L.; Reubelt, J.; Riccobene, G.; Rossi, C.; Rovelli, A.; Saldaña, M.; Salvadori, I.; Samtleben, D. F. E.; Sánchez García, A.; Sánchez Losa, A.; Sanguineti, M.; Santangelo, A.; Santonocito, D.; Sapienza, P.; Schimmel, F.; Schmelling, J.; Sciacca, V.; Sedita, M.; Seitz, T.; Sgura, I.; Simeone, F.; Siotis, I.; Sipala, V.; Spisso, B.; Spurio, M.; Stavropoulos, G.; Steijger, J.; Stellacci, S. M.; Stransky, D.; Taiuti, M.; Tayalati, Y.; Tézier, D.; Theraube, S.; Thompson, L.; Timmer, P.; Tönnis, C.; Trasatti, L.; Trovato, A.; Tsirigotis, A.; Tzamarias, S.; Tzamariudaki, E.; Vallage, B.; Van Elewyck, V.; Vermeulen, J.; Vicini, P.; Viola, S.; Vivolo, D.; Volkert, M.; Voulgaris, G.; Wiggers, L.; Wilms, J.; de Wolf, E.; Zachariadou, K.; Zornoza, J. D.; Zúñiga, J.

2016-08-01

The main objectives of the KM3NeT Collaboration are (i) the discovery and subsequent observation of high-energy neutrino sources in the Universe and (ii) the determination of the mass hierarchy of neutrinos. These objectives are strongly motivated by two recent important discoveries, namely: (1) the high-energy astrophysical neutrino signal reported by IceCube and (2) the sizable contribution of electron neutrinos to the third neutrino mass eigenstate as reported by Daya Bay, Reno and others. To meet these objectives, the KM3NeT Collaboration plans to build a new Research Infrastructure consisting of a network of deep-sea neutrino telescopes in the Mediterranean Sea. A phased and distributed implementation is pursued which maximises the access to regional funds, the availability of human resources and the synergistic opportunities for the Earth and sea sciences community. Three suitable deep-sea sites are selected, namely off-shore Toulon (France), Capo Passero (Sicily, Italy) and Pylos (Peloponnese, Greece). The infrastructure will consist of three so-called building blocks. A building block comprises 115 strings, each string comprises 18 optical modules and each optical module comprises 31 photo-multiplier tubes. Each building block thus constitutes a three-dimensional array of photo sensors that can be used to detect the Cherenkov light produced by relativistic particles emerging from neutrino interactions. Two building blocks will be sparsely configured to fully explore the IceCube signal with similar instrumented volume, different methodology, improved resolution and complementary field of view, including the galactic plane. One building block will be densely configured to precisely measure atmospheric neutrino oscillations.

October 2003 Maine DOT research peer exchange.

DOT National Transportation Integrated Search

2003-10-01

A theme or focus area for this exchange was to follow NCHRP Synthesis 280, Seven : Keys to Building a Robust Research Program. These keys are: : 1. Found it on trust Ensure a trusting relationship between research unit and : department. : 2. Mark...

Solar cells using quantum funnels.

PubMed

Kramer, Illan J; Levina, Larissa; Debnath, Ratan; Zhitomirsky, David; Sargent, Edward H

2011-09-14

Colloidal quantum dots offer broad tuning of semiconductor bandstructure via the quantum size effect. Devices involving a sequence of layers comprised of quantum dots selected to have different diameters, and therefore bandgaps, offer the possibility of funneling energy toward an acceptor. Here we report a quantum funnel that efficiently conveys photoelectrons from their point of generation toward an intended electron acceptor. Using this concept we build a solar cell that benefits from enhanced fill factor as a result of this quantum funnel. This concept addresses limitations on transport in soft condensed matter systems and leverages their advantages in large-area optoelectronic devices and systems.

Determining Possible Building Blocks of the Earth and Mars

NASA Technical Reports Server (NTRS)

Burbine, T. H.; OBrien, K. M.

2004-01-01

One of the fundamental questions concerning planetary formation is exactly what material did the planets form from? All the planets in our solar system are believed to have formed out of material from the solar nebula. Chondritic meteorites appear to sample this primitive material. Chondritic meteorites are generally classified into 13 major groups, which have a variety of compositions. Detailed studies of possible building blocks of the terrestrial planets require samples that can be used to estimate the bulk chemistry of these bodies. This study will focus on trying to determine possible building blocks of Earth and Mars since samples of these two planets can be studied in detail in the laboratory.

Surface functionalization of quantum dots with fine-structured pH-sensitive phospholipid polymer chains.

PubMed

Liu, Yihua; Inoue, Yuuki; Ishihara, Kazuhiko

2015-11-01

To add novel functionality to quantum dots (QDs), we synthesized water-soluble and pH-responsive block-type polymers by reversible addition-fragmentation chain transfer (RAFT) polymerization. The polymers were composed of cytocompatible 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer segments, which contain a small fraction of active ester groups and can be used to conjugate biologically active compounds to the polymer, and pH-responsive poly(2-(N,N-diethylamino) ethyl methacrylate (DEAEMA)) segments. One terminal of the polymer chain had a hydrophobic alkyl group that originated from the RAFT initiator. This hydrophobic group can bind to the hydrophobic layer on the QD surface. A fluorescent dye was conjugated to the polymer chains via the active ester group. The block-type polymers have an amphiphilic nature in aqueous medium. The polymers were thus easily bound to the QD surface upon evaporation of the solvent from a solution containing the block-type polymer and QDs, yielding QD/fluorescence dye-conjugated polymer hybrid nanoparticles. Fluorescence resonance energy transfer (FRET) between the QDs (donors) and the fluorescent dye molecules (acceptors) was used to obtain information on the conformational dynamics of the immobilized polymers. Higher FRET efficiency of the QD/fluorescent dye-conjugated polymer hybrid nanoparticles was observed at pH 7.4 as compared to pH 5.0 due to a stretching-shrinking conformational motion of the poly(DEAEMA) segments in response to changes in pH. We concluded that the block-type MPC polymer-modified nanoparticles could be used to evaluate the pH of cells via FRET fluorescence based on the cytocompatibility of the MPC polymer. Copyright © 2015 Elsevier B.V. All rights reserved.

Mode Engineering of Single Photons from Cavity Spontaneous Parametric Down-Conversion Source and Quantum Dots

NASA Astrophysics Data System (ADS)

Paudel, Uttam

Over the past decade, much effort has been made in identifying and characterizing systems that can form a building block of quantum networks, among which semiconductor quantum dots (QD) and spontaneous parametric down-conversion (SPDC) source are two of the most promising candidates. The work presented in this thesis will be centered on investigating and engineering the mentioned systems for generating customizable single photons. A type-II SPDC source can generate a highly flexible pair of entangled photons that can be used to interface disparate quantum systems. In this thesis, we have successfully implemented a cavity-SPDC source that emits polarization correlated photons at 942 nm with a lifetime of 950-1050ps that mode matches closely with InAs/GaAs QD photons. The source emits 80 photon pairs per second per mW pump power within the 150MHz bandwidth. Though the detection of idler photons, the source is capable of emitting heralded photons with g2?0.5 for up to 40 mW pump power. For a low pump power of 5 mW, the heralded g2 is 0.06, indicating that the system is an excellent heralded single photon source. By directly exciting a single QD with cavity-SPDC photons, we have demonstrated a heralded-absorption of SPDC photons by QD, resulting in the coupling of the two systems. Due to the large pump bandwidth, the emitted source is highly multimode in nature, requiring us to post-filter the downconverted field, resulting in a lower photon pair emission rate. We propose placing an intra-cavity etalon to suppress the multi-mode emissions and increase the photon count rate. Understanding and experimentally implementing two-photon interference (HOM) measurements will be crucial for building a scalable quantum network. A detailed theoretical description of HOM measurements is given and is experimentally demonstrated using photons emitted by QD. Through HOM measurements we demonstrated that the QD sample in the study is capable of emitting indistinguishable photons, with the visibility exceeding 95%. As an alternative approach to modifying the spectral mode of single photons, we performed phase modulation of photons emitted by a QD to generate additional sidebands that are separated by several GHz. By performing HOM measurements, we have shown that the central component and the sidebands are in the superposition states and the spectrally modified photons have a well-preserved indistinguishability. Such spectrally engineered photons can be used for phase-encoded cryptography applications. These experimental results should lay the foundations towards building a scalable hybrid quantum network.

Power spectra and auto correlation analysis of hyperfine-induced long period oscillations in the tunneling current of coupled quantum dots

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harack, B.; Leary, A.; Coish, W. A.

2013-12-04

We outline power spectra and auto correlation analysis performed on temporal oscillations in the tunneling current of coupled vertical quantum dots. The current is monitored for ∼2325 s blocks as the magnetic field is stepped through a high bias feature displaying hysteresis and switching: hallmarks of the hyperfine interaction. Quasi-periodic oscillations of ∼2 pA amplitude and of ∼100 s period are observed in the current inside the hysteretic feature. Compared to the baseline current outside the hysteretic feature the power spectral density is enhanced by up to three orders of magnitude and the auto correlation displays clear long lived oscillationsmore » about zero.« less

LEGO® Bricks as Building Blocks for Centimeter-Scale Biological Environments: The Case of Plants

PubMed Central

Lind, Kara R.; Sizmur, Tom; Benomar, Saida; Miller, Anthony; Cademartiri, Ludovico

2014-01-01

LEGO bricks are commercially available interlocking pieces of plastic that are conventionally used as toys. We describe their use to build engineered environments for cm-scale biological systems, in particular plant roots. Specifically, we take advantage of the unique modularity of these building blocks to create inexpensive, transparent, reconfigurable, and highly scalable environments for plant growth in which structural obstacles and chemical gradients can be precisely engineered to mimic soil. PMID:24963716

LEGO® bricks as building blocks for centimeter-scale biological environments: the case of plants.

PubMed

Lind, Kara R; Sizmur, Tom; Benomar, Saida; Miller, Anthony; Cademartiri, Ludovico

2014-01-01

LEGO bricks are commercially available interlocking pieces of plastic that are conventionally used as toys. We describe their use to build engineered environments for cm-scale biological systems, in particular plant roots. Specifically, we take advantage of the unique modularity of these building blocks to create inexpensive, transparent, reconfigurable, and highly scalable environments for plant growth in which structural obstacles and chemical gradients can be precisely engineered to mimic soil.

Building Blocks and Cognitive Building Blocks: Playing to Know the World Mathematically

ERIC Educational Resources Information Center

Sarama, Julie; Clements, Douglas H.

2009-01-01

The authors explore how children's play can support the development of the foundations of mathematics learning and how adults can support children's representation of--and thus the "mathematization" of--their play. The authors review research about the amount and nature of mathematics found in the free play of children. They briefly…

Trainer's Guide to Building Blocks for Teaching Preschoolers with Special Needs [CD-ROM

ERIC Educational Resources Information Center

Joseph, Gail E.; Sandall, Susan R.; Schwartz, Ilene S.

2010-01-01

An essential teaching companion for instructors of pre-K educators, this convenient CD-ROM is a vivid blueprint for effective inclusive education using the popular "Building Blocks" approach. Following the structure of the bestselling textbook, this comprehensive guide helps teacher educators provide effective instruction on the three types of…

1. NORTHWEST FRONT AND SOUTHWEST SIDE, SHOWING LOCATION OF BUILDING ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

1. NORTHWEST FRONT AND SOUTHWEST SIDE, SHOWING LOCATION OF BUILDING 0520 WEST OF FIRING CONTOL BLOCK HOUSE (BLDG. 0545), BETWEEN SLED TRACK AND CAMERA ACCESS ROAD. - Edwards Air Force Base, South Base Sled Track, Observation Block House, Station "O" area, east end of Sled Track, Lancaster, Los Angeles County, CA

Building an Early Childhood Parent-Teacher Resource Center.

ERIC Educational Resources Information Center

Holloway, Mary A.

This manual is a guidebook to the development of the Project Enlightenment Parent-Teacher Resource Center and serves as a reference for the replication of this type of center in other communities. The manual consists of three chapters that are conceptualized as building blocks, because they are sequential, incremental, and independent. Block A…

Effects of a Preschool Mathematics Curriculum: Summative Research on the "Building Blocks" Project

ERIC Educational Resources Information Center

Clements, Douglas H.; Sarama, Julie

2007-01-01

This study evaluated the efficacy of a preschool mathematics program based on a comprehensive model of developing research-based software and print curricula. Building Blocks, funded by the National Science Foundation, is a curriculum development project focused on creating research-based, technology-enhanced mathematics materials for pre-K…

PBF Reactor Building (PER620). Detail of arrangement of highdensity blocks ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

PBF Reactor Building (PER-620). Detail of arrangement of high-density blocks and other basement shielding. Date: February 1966. Ebasco Services 1205 PER/PBF 620-A-7. INEEL index no. 761-0620-00-205-123070 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

University Education in Ontario: Shared Goals & Building Blocks.

ERIC Educational Resources Information Center

Council of Ontario Universities, Toronto.

This brochure suggests five goals that are likely to be shared by the people of Ontario, their government, and the province's publicly funded universities for a strong university system, and identifies the building blocks and resource-related commitments that would enable Ontario universities to achieve these goals. The goals are: (1) all…

Stereoselective total synthesis of Oxylipin from open chain gluco-configured building block.

PubMed

Borkar, Santosh Ramdas; Aidhen, Indrapal Singh

2017-04-18

Total synthesis of naturally occurring Oxylipin has been achieved from open chain gluco-configured building block which is readily assembled from inexpensive and commercially available D-(+)-gluconolactone. Grignard reaction and Wittig olefination reactions are key steps for the requisite CC bond formation. Copyright © 2017. Published by Elsevier Ltd.

Patterning nonisometric origami in nematic elastomer sheets

NASA Astrophysics Data System (ADS)

Plucinsky, Paul; Kowalski, Benjamin A.; White, Timothy J.; Bhattacharya, Kaushik

Nematic elastomers dramatically change their shape in response to diverse stimuli including light and heat. In this paper, we provide a systematic framework for the design of complex three dimensional shapes through the actuation of heterogeneously patterned nematic elastomer sheets. These sheets are composed of \\textit{nonisometric origami} building blocks which, when appropriately linked together, can actuate into a diverse array of three dimensional faceted shapes. We demonstrate both theoretically and experimentally that: 1) the nonisometric origami building blocks actuate in the predicted manner, 2) the integration of multiple building blocks leads to complex multi-stable, yet predictable, shapes, 3) we can bias the actuation experimentally to obtain a desired complex shape amongst the multi-stable shapes. We then show that this experimentally realized functionality enables a rich possible design landscape for actuation using nematic elastomers. We highlight this landscape through theoretical examples, which utilize large arrays of these building blocks to realize a desired three dimensional origami shape. In combination, these results amount to an engineering design principle, which we hope will provide a template for the application of nematic elastomers to emerging technologies.

Structure of clusters and building blocks in amylopectin from African rice accessions.

PubMed

Gayin, Joseph; Abdel-Aal, El-Sayed M; Marcone, Massimo; Manful, John; Bertoft, Eric

2016-09-05

Enzymatic hydrolysis in combination with gel-permeation and anion-exchange chromatography techniques were employed to characterise the composition of clusters and building blocks of amylopectin from two African rice (Oryza glaberrima) accessions-IRGC 103759 and TOG 12440. The samples were compared with one Asian rice (Oryza sativa) sample (cv WITA 4) and one O. sativa×O. glaberrima cross (NERICA 4). The average DP of clusters from the African rice accessions (ARAs) was marginally larger (DP=83) than in WITA 4 (DP=81). However, regarding average number of chains, clusters from the ARAs represented both the smallest and largest clusters. Overall, the result suggested that the structure of clusters in TOG 12440 was dense with short chains and high degree of branching, whereas the situation was the opposite in NERICA 4. IRGC 103759 and WITA 4 possessed clusters with intermediate characteristics. The commonest type of building blocks in all samples was group 2 (single branched dextrins) representing 40.3-49.4% of the blocks, while groups 3-6 were found in successively lower numbers. The average number of building blocks in the clusters was significantly larger in NERICA 4 (5.8) and WITA 4 (5.7) than in IRGC 103759 and TOG 12440 (5.1 and 5.3, respectively). Copyright © 2016 Elsevier Ltd. All rights reserved.

An evaluation of Delaware's DelTrac program : building an integrated transportation management system

DOT National Transportation Integrated Search

2004-06-01

The DelTrac deployment experience included both successes and unmet challenges. Programmatically, the DelTrac approach to managing ITS has been successful at creating a great deal of integration and cooperation between organizations at DelDOT. Stakeh...

Tunable photonic cavity coupled to a voltage-biased double quantum dot system: Diagrammatic nonequilibrium Green's function approach

NASA Astrophysics Data System (ADS)

Agarwalla, Bijay Kumar; Kulkarni, Manas; Mukamel, Shaul; Segal, Dvira

2016-07-01

We investigate gain in microwave photonic cavities coupled to voltage-biased double quantum dot systems with an arbitrarily strong dot-lead coupling and with a Holstein-like light-matter interaction, by employing the diagrammatic Keldysh nonequilibrium Green's function approach. We compute out-of-equilibrium properties of the cavity: its transmission, phase response, mean photon number, power spectrum, and spectral function. We show that by the careful engineering of these hybrid light-matter systems, one can achieve a significant amplification of the optical signal with the voltage-biased electronic system serving as a gain medium. We also study the steady-state current across the device, identifying elastic and inelastic tunneling processes which involve the cavity mode. Our results show how recent advances in quantum electronics can be exploited to build hybrid light-matter systems that behave as microwave amplifiers and photon source devices. The diagrammatic Keldysh approach is primarily discussed for a cavity-coupled double quantum dot architecture, but it is generalizable to other hybrid light-matter systems.

ZnS/Al2S3 Layer as a Blocking Layer in Quantum Dot Sensitized Solar Cells

NASA Astrophysics Data System (ADS)

Vafapoor, Borzoo; Fathi, Davood; Eskandari, Mehdi

2017-12-01

In this research, the effect of treatment of the CdS/CdSe sensitized ZnO photoanode by ZnS, Al2S3, and ZnS/Al2S3 nanoparticles as a barrier layer on the performance of quantum dot sensitized solar cell is investigated. Current density-voltage (J-V) characteristics show that cell efficiency is enhanced from 3.62% to 4.82% with treatment of a CdS/CdSe/ZnS sensitized ZnO photoanode by Al2S3 nanoparticles. In addition, short- circuit current density (J sc) is increased from 11.5 mA/cm2 to 14.8 mA/cm2. The results extracted from electrochemical impedance spectroscopy indicate that charge transfer resistance (R ct) in photoanode/electrolyte interfaces decreases with deposition of Al2S3 nanoparticles on CdS/CdSe/ZnS sensitized ZnO photoanodes, while the chemical capacitance of photoanode (C μ ) and electron lifetime (t n) increase. Also, results revealed that cell performance is considerably decreased with the treatment of the AL2S3 blocking layer incorporated between ZnO nanorods and CdS/CdSe QDs.

ZnS/Al2S3 Layer as a Blocking Layer in Quantum Dot Sensitized Solar Cells

NASA Astrophysics Data System (ADS)

Vafapoor, Borzoo; Fathi, Davood; Eskandari, Mehdi

2018-03-01

In this research, the effect of treatment of the CdS/CdSe sensitized ZnO photoanode by ZnS, Al2S3, and ZnS/Al2S3 nanoparticles as a barrier layer on the performance of quantum dot sensitized solar cell is investigated. Current density-voltage ( J- V) characteristics show that cell efficiency is enhanced from 3.62% to 4.82% with treatment of a CdS/CdSe/ZnS sensitized ZnO photoanode by Al2S3 nanoparticles. In addition, short- circuit current density ( J sc) is increased from 11.5 mA/cm2 to 14.8 mA/cm2. The results extracted from electrochemical impedance spectroscopy indicate that charge transfer resistance ( R ct) in photoanode/electrolyte interfaces decreases with deposition of Al2S3 nanoparticles on CdS/CdSe/ZnS sensitized ZnO photoanodes, while the chemical capacitance of photoanode ( C μ ) and electron lifetime ( t n) increase. Also, results revealed that cell performance is considerably decreased with the treatment of the AL2S3 blocking layer incorporated between ZnO nanorods and CdS/CdSe QDs.

Effective Light Directed Assembly of Building Blocks with Microscale Control.

PubMed

Dinh, Ngoc-Duy; Luo, Rongcong; Christine, Maria Tankeh Asuncion; Lin, Weikang Nicholas; Shih, Wei-Chuan; Goh, James Cho-Hong; Chen, Chia-Hung

2017-06-01

Light-directed forces have been widely used to pattern micro/nanoscale objects with precise control, forming functional assemblies. However, a substantial laser intensity is required to generate sufficient optical gradient forces to move a small object in a certain direction, causing limited throughput for applications. A high-throughput light-directed assembly is demonstrated as a printing technology by introducing gold nanorods to induce thermal convection flows that move microparticles (diameter = 40 µm to several hundreds of micrometers) to specific light-guided locations, forming desired patterns. With the advantage of effective light-directed assembly, the microfluidic-fabricated monodispersed biocompatible microparticles are used as building blocks to construct a structured assembly (≈10 cm scale) in ≈2 min. The control with microscale precision is approached by changing the size of the laser light spot. After crosslinking assembly of building blocks, a novel soft material with wanted pattern is approached. To demonstrate its application, the mesenchymal stem-cell-seeded hydrogel microparticles are prepared as functional building blocks to construct scaffold-free tissues with desired structures. This light-directed fabrication method can be applied to integrate different building units, enabling the bottom-up formation of materials with precise control over their internal structure for bioprinting, tissue engineering, and advanced manufacturing. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

SynTrack: DNA Assembly Workflow Management (SynTrack) v2.0.1

DOE Office of Scientific and Technical Information (OSTI.GOV)

MENG, XIANWEI; SIMIRENKO, LISA

2016-12-01

SynTrack is a dynamic, workflow-driven data management system that tracks the DNA build process: Management of the hierarchical relationships of the DNA fragments; Monitoring of process tasks for the assembly of multiple DNA fragments into final constructs; Creations of vendor order forms with selectable building blocks. Organizing plate layouts barcodes for vendor/pcr/fusion/chewback/bioassay/glycerol/master plate maps (default/condensed); Creating or updating Pre-Assembly/Assembly process workflows with selected building blocks; Generating Echo pooling instructions based on plate maps; Tracking of building block orders, received and final assembled for delivering; Bulk updating of colony or PCR amplification information, fusion PCR and chewback results; Updating with QA/QCmore » outcome with .csv & .xlsx template files; Re-work assembly workflow enabled before and after sequencing validation; and Tracking of plate/well data changes and status updates and reporting of master plate status with QC outcomes.« less

Building Trades. Block II. Foundations.

ERIC Educational Resources Information Center

Texas A and M Univ., College Station. Vocational Instructional Services.

Twelve informational lessons and eleven manipulative lessons are provided on foundations as applied to the building trades. Informational lessons cover land measurements; blueprint reading; level instruments; building and site planning; building site preparation; laying out building lines; soil preparation and special evacuation; concrete forms;…

The Building Blocks of Digital Media Literacy: Socio-Material Participation and the Production of Media Knowledge

ERIC Educational Resources Information Center

Dezuanni, Michael

2015-01-01

This article outlines the knowledge and skills students develop when they engage in digital media production and analysis in school settings. The metaphor of "digital building blocks" is used to describe the material practices, conceptual understandings and production of knowledge that lead to the development of digital media literacy.…

Plumbing Specialist II & III, 3-22. Military Curriculum Materials for Vocational and Technical Education.

ERIC Educational Resources Information Center

Ohio State Univ., Columbus. National Center for Research in Vocational Education.

These military-developed curriculum materials consist of a course description, course chart, plan of instruction, lesson plans, study guides, and workbooks for use in training plumbing specialists II and III. Covered in the course blocks are building waste systems and exterior and interior supply systems. Course block II, on building waste…

Using Interlocking Toy Building Blocks to Assess Conceptual Understanding in Chemistry

ERIC Educational Resources Information Center

Geyer, Michael J.

2017-01-01

A current emphasis on teaching conceptual chemistry via the particulate nature of matter has led to the need for new, effective ways to assess students' conceptual understanding of this view of chemistry. This article provides a simple, inexpensive way to use interlocking toy building blocks (e.g., LEGOs) in both formative and summative…

Functionalized coronenes: synthesis, solid structure, and properties.

PubMed

Wu, Di; Zhang, Hua; Liang, Jinhua; Ge, Haojie; Chi, Chunyan; Wu, Jishan; Liu, Sheng Hua; Yin, Jun

2012-12-21

The construction of coronenes using simple building blocks is a challenging task. In this work, triphenylene was used as a building block to construct functionalized coronenes, and their solid structures and optoelectronic properties were investigated. The single crystal structures showed that coronenes have different packing motifs. Their good solubility and photostability make them potential solution-processable candidates for organic devices.

The Development of Logico-Mathematical Knowledge in a Block-Building Activity at Ages 1-4

ERIC Educational Resources Information Center

Kamii, Constance; Miyakawa, Yoko; Kato, Yasuhiko

2004-01-01

To study the developmental interrelationships among various aspects of logico-mathematical knowledge, 80 one- to 4-year-olds were individually asked to build "something tall" with 20 blocks. Percentages of new and significant behaviors increased with age and were analyzed in terms of the development of logico-mathematical relationships. It was…

Building Blocks of Contemporary HRD Research: A Citation Analysis on Human Resource Development Quarterly between 2007 and 2013

ERIC Educational Resources Information Center

Mehdiabadi, Amir Hedayati; Seo, Gaeun; Huang, Wenhao David; Han, Seung-hyun Caleb

2017-01-01

Human resource development is known to encapsulate a collection of social science disciplines including communications, psychology, and economics. Since these and other similar areas are the cornerstones of HRD, the changing nature of HRD demands constant reflections on the value and building blocks of contemporary HRD inquiries. This article…

Quantitative NMR Approach to Optimize the Formation of Chemical Building Blocks from Abundant Carbohydrates.

PubMed

Elliot, Samuel G; Tolborg, Søren; Sádaba, Irantzu; Taarning, Esben; Meier, Sebastian

2017-07-21

The future role of biomass-derived chemicals relies on the formation of diverse functional monomers in high yields from carbohydrates. Recently, it has become clear that a series of α-hydroxy acids, esters, and lactones can be formed from carbohydrates in alcohol and water solvents using tin-containing catalysts such as Sn-Beta. These compounds are potential building blocks for polyesters bearing additional olefin and alcohol functionalities. An NMR approach was used to identify, quantify, and optimize the formation of these building blocks in the Sn-Beta-catalyzed transformation of abundant carbohydrates. Record yields of the target molecules can be achieved by obstructing competing reactions through solvent selection. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Comprehensive assessment of the efficiency of high-rise construction projects in the form of urban blocks

NASA Astrophysics Data System (ADS)

Orlov, Alexandr; Chubarkina, Irina

2018-03-01

The paper is dedicated to main modern trends in the area of high-rise construction. The classification of buildings and structures by height is given. Functional distribution by the height of buildings is presented. A review of positive and negative aspects of high-rise construction from the economic point of view is given. On the basis of the data obtained, it is proposed to build up residential microdistricts in the form of urban blocks. A plan of microdistricts development is presented. It takes into account urban blocks and includes their main characteristics. An economic and mathematical model was developed to carry out a comprehensive assessment of the effectiveness of high-rise construction projects.

Advances in metabolic pathway and strain engineering paving the way for sustainable production of chemical building blocks.

PubMed

Chen, Yun; Nielsen, Jens

2013-12-01

Bio-based production of chemical building blocks from renewable resources is an attractive alternative to petroleum-based platform chemicals. Metabolic pathway and strain engineering is the key element in constructing robust microbial chemical factories within the constraints of cost effective production. Here we discuss how the development of computational algorithms, novel modules and methods, omics-based techniques combined with modeling refinement are enabling reduction in development time and thus advance the field of industrial biotechnology. We further discuss how recent technological developments contribute to the development of novel cell factories for the production of the building block chemicals: adipic acid, succinic acid and 3-hydroxypropionic acid. Copyright © 2013 Elsevier Ltd. All rights reserved.

An Ap-Structure with Finslerian Flavor I:. the Principal Idea

NASA Astrophysics Data System (ADS)

Wanas, M. I.

A geometric structure (FAP-structure), having both absolute parallelism and Finsler properties, is constructed. The building blocks of this structure are assumed to be functions of position and direction. A nonlinear connection emerges naturally and is defined in terms of the building blocks of the structure. Two linear connections, one of Berwald type and the other of the Cartan type, are defined using the nonlinear connection of the FAP. Both linear connections are nonsymmetric and consequently admit torsion. A metric tensor is defined in terms of the building blocks of the structure. The condition for this metric to be a Finslerian one is obtained. Also, the condition for an FAP-space to be an AP-one is given.

High-Performance CuInS 2 Quantum Dot Laminated Glass Luminescent Solar Concentrators for Windows

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bergren, Matthew R.; Makarov, Nikolay S.; Ramasamy, Karthik

Building-integrated sunlight harvesting utilizing laminated glass luminescent solar concentrators (LSCs) is proposed. By incorporating high quantum yield (>90%), NIR-emitting CuInS2/ZnS quantum dots into the polymer interlayer between two sheets of low-iron float glass, a record optical efficiency of 8.1% is demonstrated for a 10 cm x 10 cm device that transmits ~44% visible light. After completing prototypes by attaching silicon solar cells along the perimeter of the device, the electrical power conversion efficiency was certified at 2.2% with a black background and at 2.9% using a reflective substrate. This 'drop-in' LSC solution is particularly attractive because it fits within themore » existing glazing industry value chain with only modest changes to typical glazing products. Performance modeling predicts >1 GWh annual electricity production for a typical urban skyscraper in most major U.S. cities, enabling significant energy cost savings and potentially 'net-zero' buildings.« less

Simplified Perovskite Solar Cell with 4.1% Efficiency Employing Inorganic CsPbBr3 as Light Absorber.

PubMed

Duan, Jialong; Zhao, Yuanyuan; He, Benlin; Tang, Qunwei

2018-05-01

Perovskite solar cells with cost-effectiveness, high power conversion efficiency, and improved stability are promising solutions to the energy crisis and environmental pollution. However, a wide-bandgap inorganic-semiconductor electron-transporting layer such as TiO 2 can harvest ultraviolet light to photodegrade perovskite halides, and the high cost of a state-of-the-art hole-transporting layer is an economic burden for commercialization. Here, the building of a simplified cesium lead bromide (CsPbBr 3 ) perovskite solar cell with fluorine-doped tin oxide (FTO)/CsPbBr 3 /carbon architecture by a multistep solution-processed deposition technology is demonstrated, achieving an efficiency as high as 4.1% and improved stability upon interfacial modification by graphene quantum dots and CsPbBrI 2 quantum dots. This work provides new opportunities of building next-generation solar cells with significantly simplified processes and reduced production costs. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Deliberate Design of TiO2 Nanostructures towards Superior Photovoltaic Cells.

PubMed

Sun, Ziqi; Liao, Ting; Sheng, Liyuan; Kou, Liangzhi; Kim, Jung Ho; Dou, Shi Xue

2016-08-01

TiO2 nanostructures are being sought after as flexibly utilizable building blocks for the fabrication of the mesoporous thin-film photoelectrodes that are the heart of the third-generation photovoltaic devices, such as dye-sensitized solar cells (DSSCs), quantum-dot-sensitized solar cells (QDSSCs), and the recently promoted perovskite-type solar cells. Here, we report deliberate tailoring of TiO2 nanostructures for superior photovoltaic cells. Morphology engineering of TiO2 nanostructures is realized by designing synthetic protocols in which the precursor hydrolysis, crystal growth, and oligomer self-organization are precisely controlled. TiO2 nanostructures in forms varying from isolated nanocubes, nanorods, and cross-linked nanorods to complex hierarchical structures and shape-defined mesoporous micro-/nanostructures were successfully synthesized. The photoanodes made from the shape-defined mesoporous TiO2 microspheres and nanospindles presented superior performances, owing to the well-defined overall shapes and the inner ordered nanochannels, which allow not only a high amount of dye uptake, but also improved visible-light absorption. This study provides a new way to seek an optimal synthetic protocol to meet the required functionality of the nanomaterials. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Blockbusters: Ideas for the Block Center.

ERIC Educational Resources Information Center

Adams, Polly K.; Nesmith, Jaynie

1996-01-01

Goals of block building in early childhood classrooms focus on physical, social, cognitive, and emotional development. Reports survey results of the value teachers place on block play. Offers illustrations of task cards to use with blocks in math, language arts, social studies, and science. Discusses guidelines and suggests idea cards and sentence…

From empower to Green Dot : successful strategies and lessons learned in developing comprehensive sexual violence primary prevention programming.

PubMed

Cook-Craig, Patricia G; Millspaugh, Phyllis H; Recktenwald, Eileen A; Kelly, Natalie C; Hegge, Lea M; Coker, Ann L; Pletcher, Tisha S

2014-10-01

This case study describes Kentucky's partnership with the Centers for Disease Control and Prevention (CDC) EMPOWER (Enhancing and Making Programs Work to End Rape) program to enhance the mission and services of existing rape crisis centers to include comprehensive primary prevention programming to reduce rates of sexual violence perpetration. The planning process and the successful implementation of a statewide, 5-year, randomized control trial study of a bystander prevention program (Green Dot), and its evaluation are described. Lessons learned in generating new questions, seeking funding, building relationships and capacity, and disseminating knowledge are presented. © The Author(s) 2014.

Molecular Building Block-Based Electronic Charges for High-Throughput Screening of Metal-Organic Frameworks for Adsorption Applications.

PubMed

Argueta, Edwin; Shaji, Jeena; Gopalan, Arun; Liao, Peilin; Snurr, Randall Q; Gómez-Gualdrón, Diego A

2018-01-09

Metal-organic frameworks (MOFs) are porous crystalline materials with attractive properties for gas separation and storage. Their remarkable tunability makes it possible to create millions of MOF variations but creates the need for fast material screening to identify promising structures. Computational high-throughput screening (HTS) is a possible solution, but its usefulness is tied to accurate predictions of MOF adsorption properties. Accurate adsorption simulations often require an accurate description of electrostatic interactions, which depend on the electronic charges of the MOF atoms. HTS-compatible methods to assign charges to MOF atoms need to accurately reproduce electrostatic potentials (ESPs) and be computationally affordable, but current methods present an unsatisfactory trade-off between computational cost and accuracy. We illustrate a method to assign charges to MOF atoms based on ab initio calculations on MOF molecular building blocks. A library of building blocks with built-in charges is thus created and used by an automated MOF construction code to create hundreds of MOFs with charges "inherited" from the constituent building blocks. The molecular building block-based (MBBB) charges are similar to REPEAT charges-which are charges that reproduce ESPs obtained from ab initio calculations on crystallographic unit cells of nanoporous crystals-and thus similar predictions of adsorption loadings, heats of adsorption, and Henry's constants are obtained with either method. The presented results indicate that the MBBB method to assign charges to MOF atoms is suitable for use in computational high-throughput screening of MOFs for applications that involve adsorption of molecules such as carbon dioxide.

Statistical analysis of atmospheric turbulence about a simulated block building

NASA Technical Reports Server (NTRS)

Steely, S. L., Jr.

1981-01-01

An array of towers instrumented to measure the three components of wind speed was used to study atmospheric flow about a simulated block building. Two-point spacetime correlations of the longitudinal velocity component were computed along with two-point spatial correlations. These correlations are in good agreement with fundamental concepts of fluid mechanics. The two-point spatial correlations computed directly were compared with correlations predicted by Taylor's hypothesis and excellent agreement was obtained at the higher levels which were out of the building influence. The correlations fall off significantly in the building wake but recover beyond the wake to essentially the same values in the undisturbed, higher regions.

76 FR 70042 - Airworthiness Directives; Pacific Aerospace Limited Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-10

... DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. FAA-2011...), Department of Transportation (DOT). ACTION: Final rule. SUMMARY: We are adopting a new airworthiness... Facility, U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12...

78 FR 78506 - Research and Development; Public Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-26

... considered for inclusion in its future work. Information Regarding the Research and Development Public... DOT Headquarters, West Building, Oklahoma Conference Room, and 1200 New Jersey Avenue SE., Washington... information to the docket of this proceeding (PHMSA- 2013-0261) by any of the following methods: Federal e...

"Looking through the Eyes of the Learner": Implementation of Building Blocks for Student Engagement

ERIC Educational Resources Information Center

D'Annolfo, Suzanne Cordier; Schumann, Jeffrey A.

2012-01-01

The Building Blocks for Student Engagement (BBSE) protocol was designed to provide a consistent framework of common language and a visual point of reference shared among students, teachers and school leaders to keep a laser-like focus on the instructional core and student engagement. Grounded in brain-based learning and implemented in urban,…

Oligomers and Polymers Based on Pentacene Building Blocks

PubMed Central

Lehnherr, Dan; Tykwinski, Rik R.

2010-01-01

Functionalized pentacene derivatives continue to provide unique materials for organic semiconductor applications. Although oligomers and polymers based on pentacene building blocks remain quite rare, recent synthetic achievements have provided a number of examples with varied structural motifs. This review highlights recent work in this area and, when possible, contrasts the properties of defined-length pentacene oligomers to those of mono- and polymeric systems.

Public Opinion on Youth, Crime and Race: A Guide for Advocates. Building Blocks for Youth.

ERIC Educational Resources Information Center

Soler, Mark

This guide summarizes public opinion research on youth and juvenile justice issues from the Building Blocks for Youth focus groups and various national polls. Overall, the public is less fearful about crime than in the past but believes juvenile crime is increasing. There is serious public concern about the effectiveness of the juvenile justice…

C–H arylation of unsubstituted furan and thiophene with acceptor bromides: access to donor–acceptor–donor-type building blocks for organic electronics.

PubMed

Matsidik, Rukiya; Martin, Johannes; Schmidt, Simon; Obermayer, Johannes; Lombeck, Florian; Nübling, Fritz; Komber, Hartmut; Fazzi, Daniele; Sommer, Michael

2015-01-16

Pd-catalyzed direct arylation (DA) reaction conditions have been established for unsubstituted furan (Fu) and thiophene (Th) with three popular acceptor building blocks to be used in materials for organic electronics, namely 4,7-dibromo-2,1,3-benzothiadiazole (BTBr2), N,N′-dialkylated 2,6-dibromonaphthalene-1,4,5,8-bis(dicarboximide) (NDIBr2), and 1,4-dibromotetrafluorobenzene (F4Br2). Reactions with BTBr2, F4Br2, and NDIBr2 require different solvents to obtain high yields. The use of dimethylacetamide (DMAc) is essential for the successful coupling of BTBr2 and F4Br2, but detrimental for NDIBr2, as the electron-deficient NDI core is prone to nucleophilic core substitution in DMAc as solvent but not in toluene. NDIFu2 is much more planar compared to NDITh2, resulting in an enhanced charge-transfer character, which makes it an interesting building block for conjugated systems designed for organic electronics. This study highlights direct arylation as a simple and inexpensive method to construct a series of important donor–acceptor–donor building blocks to be further used for the preparation of a variety of conjugated materials.

A “fullerene-carbon nanotube” structure with tunable mechanical properties

NASA Astrophysics Data System (ADS)

Ji, W. M.; Zhang, L. W.; Liew, K. M.

2018-03-01

Carbon-based nanostructures have drawn tremendous research interest and become promising building blocks for the new generation of smart sensors and devices. Utilizing a bottom-up strategy, the chemical interconnecting sp 3 covalent bond between carbon building blocks is an efficient way to enhance its Young's modulus and ductility. The formation of sp 3 covalent bond, however, inevitably degrades its ultimate tensile strength caused by stress concentration at the junction. By performing a molecular dynamics simulation of tensile deformation for a fullerene-carbon nanotube (FCNT) structure, we propose a tunable strategy in which fullerenes with various angle energy absorption capacities are utilized as building blocks to tune their ductile behavior, while still maintaining a good ultimate tensile strength of the carbon building blocks. A higher ultimate tensile strength is revealed with the reduction of stress concentration at the junction. A brittle-to-ductile transition during the tensile deformation is detected through the structural modification. The development of ductile behavior is attributed to the improvement of energy propagation ability during the fracture initiation, in which the released energy from bonds fracture is mitigated properly, leading to the further development of mechanical properties.

De novo design of molecular architectures by evolutionary assembly of drug-derived building blocks.

PubMed

Schneider, G; Lee, M L; Stahl, M; Schneider, P

2000-07-01

An evolutionary algorithm was developed for fragment-based de novo design of molecules (TOPAS, TOPology-Assigning System). This stochastic method aims at generating a novel molecular structure mimicking a template structure. A set of approximately 25,000 fragment structures serves as the building block supply, which were obtained by a straightforward fragmentation procedure applied to 36,000 known drugs. Eleven reaction schemes were implemented for both fragmentation and building block assembly. This combination of drug-derived building blocks and a restricted set of reaction schemes proved to be a key for the automatic development of novel, synthetically tractable structures. In a cyclic optimization process, molecular architectures were generated from a parent structure by virtual synthesis, and the best structure of a generation was selected as the parent for the subsequent TOPAS cycle. Similarity measures were used to define 'fitness', based on 2D-structural similarity or topological pharmacophore distance between the template molecule and the variants. The concept of varying library 'diversity' during a design process was consequently implemented by using adaptive variant distributions. The efficiency of the design algorithm was demonstrated for the de novo construction of potential thrombin inhibitors mimicking peptide and non-peptide template structures.

Versatile plasmid-based expression systems for Gram-negative bacteria--General essentials exemplified with the bacterium Ralstonia eutropha H16.

PubMed

Gruber, Steffen; Schwab, Helmut; Koefinger, Petra

2015-12-25

The Gram-negative bacterium Escherichia coli is currently the most efficient and widely used prokaryotic host for recombinant protein and metabolite production. However, due to some limitations and to various interesting features of other Gram-negative bacteria efficient vector systems applicable to a broad range are desired. Basic building blocks for plasmid-based vectors include besides the need for a suitable selection marker in the first line a proper replication and maintenance system. In addition to these basic requirements, further elements are needed for Gram-negative bacteria beyond E. coli, such as Pseudomonas pudita, Ralstonia eutropha, Burkholderia glumae or Acinetobacter sp.. Established building blocks have to be adapted and new building blocks providing the desired functions need to be identified and exploited. This minireview addresses so far described and used genetic elements for broad host range replication, efficient plasmid maintenance, and conjugative plasmid transfer as well as expression elements and protein secretion signals. The industrially important bacterium R. eutropha H16 was chosen as a model organism to provide specific data on the effectivity and utility of building blocks based on such genetic elements. Copyright © 2015 Elsevier B.V. All rights reserved.

Geospatial-enabled Data Exploration and Computation through Data Infrastructure Building Blocks

NASA Astrophysics Data System (ADS)

Song, C. X.; Biehl, L. L.; Merwade, V.; Villoria, N.

2015-12-01

Geospatial data are present everywhere today with the proliferation of location-aware computing devices and sensors. This is especially true in the scientific community where large amounts of data are driving research and education activities in many domains. Collaboration over geospatial data, for example, in modeling, data analysis and visualization, must still overcome the barriers of specialized software and expertise among other challenges. The GABBs project aims at enabling broader access to geospatial data exploration and computation by developing spatial data infrastructure building blocks that leverage capabilities of end-to-end application service and virtualized computing framework in HUBzero. Funded by NSF Data Infrastructure Building Blocks (DIBBS) initiative, GABBs provides a geospatial data architecture that integrates spatial data management, mapping and visualization and will make it available as open source. The outcome of the project will enable users to rapidly create tools and share geospatial data and tools on the web for interactive exploration of data without requiring significant software development skills, GIS expertise or IT administrative privileges. This presentation will describe the development of geospatial data infrastructure building blocks and the scientific use cases that help drive the software development, as well as seek feedback from the user communities.

Molecular profiling of single cancer cells and clinical tissue specimens with semiconductor quantum dots

PubMed Central

Xing, Yun; Smith, Andrew M; Agrawal, Amit; Ruan, Gang; Nie, Shuming

2006-01-01

Semiconductor quantum dots (QDs) are a new class of fluorescent labels with broad applications in biomedical imaging, disease diagnostics, and molecular and cell biology. In comparison with organic dyes and fluorescent proteins, quantum dots have unique optical and electronic properties such as size-tunable light emission, improved signal brightness, resistance against photobleaching, and simultaneous excitation of multiple fluorescence colors. Recent advances have led to multifunctional nanoparticle probes that are highly bright and stable under complex in vitro and in vivo conditions. New designs involve encapsulating luminescent QDs with amphiphilic block copolymers, and linking the polymer coating to tumor-targeting ligands and drug-delivery functionalities. These improved QDs have opened new possibilities for real-time imaging and tracking of molecular targets in living cells, for multiplexed analysis of biomolecular markers in clinical tissue specimens, and for ultrasensitive imaging of malignant tumors in living animal models. In this article, we briefly discuss recent developments in bioaffinity QD probes and their applications in molecular profiling of individual cancer cells and clinical tissue specimens. PMID:17722280

Two-photon photoemission study of competing Auger and surface-mediated relaxation of hot electrons in CdSe quantum dot solids.

PubMed

Sippel, Philipp; Albrecht, Wiebke; Mitoraj, Dariusz; Eichberger, Rainer; Hannappel, Thomas; Vanmaekelbergh, Daniel

2013-04-10

Solids composed of colloidal quantum dots hold promise for third generation highly efficient thin-film photovoltaic cells. The presence of well-separated conduction electron states opens the possibility for an energy-selective collection of hot and equilibrated carriers, pushing the efficiency above the one-band gap limit. However, in order to reach this goal the decay of hot carriers within a band must be better understood and prevented, eventually. Here, we present a two-photon photoemission study of the 1Pe→1Se intraband relaxation dynamics in a CdSe quantum dot solid that mimics the active layer in a photovoltaic cell. We observe fast hot electron relaxation from the 1Pe to the 1Se state on a femtosecond-scale by Auger-type energy donation to the hole. However, if the oleic acid capping is exchanged for hexanedithiol capping, fast deep hole trapping competes efficiently with this relaxation pathway, blocking the Auger-type electron-hole energy exchange. A slower decay becomes then visible; we provide evidence that this is a multistep process involving the surface.

Quantum dots encoded Au coated polystyrene bead arranged micro-channel for multiplex arrays.

PubMed

Cao, Yuan-Cheng; Wang, Zhan; Yang, Runyu; Zou, Linling; Zhou, Zhen; Mi, Tie; Shi, Hong

2016-01-01

This paper describes a promising micro-channel multiplex immunoassay method based on the quantum dots encoded beads which requires micro-volume sample. Briefly, Au nanoparticles coated polystyrene (PS) beads were prepared and Quantum dots (QDs) were employed to encode 4 types of the PS beads by different emission wavelength QDs and various intensities. Different coding types of the beads were immobilized with different antibodies on the surface and BSA was used to block the unsatisfied sites. The antibody linked beads were then arranged in the 150 µm diameter optical capillary where the specific reactions took place before the detections. Results showed that the antibody on the Au coated surface maintains the bioactivity for the immunoreactions. Using this system, the fluorescent intensity was linear with analyte concentration in the range of 1×10(-7)-1×10(-5) mg/mL (RSD<5%, 4 repeats) and the lower detection limit reached 5×10(-8) mg/mL. It was proved to be a promising approach for the future miniaturization analytical devices. Copyright © 2015 Elsevier B.V. All rights reserved.

InAs/GaAs p-type quantum dot infrared photodetector with higher efficiency

NASA Astrophysics Data System (ADS)

Lao, Yan-Feng; Wolde, Seyoum; Unil Perera, A. G.; Zhang, Y. H.; Wang, T. M.; Liu, H. C.; Kim, J. O.; Schuler-Sandy, Ted; Tian, Zhao-Bing; Krishna, S. S.

2013-12-01

An InAs/GaAs quantum dot infrared photodetector (QDIP) based on p-type valence-band intersublevel hole transitions as opposed to conventional electron transitions is reported. Two response bands observed at 1.5-3 and 3-10 μm are due to transitions from the heavy-hole to spin-orbit split-off QD level and from the heavy-hole to heavy-hole level, respectively. Without employing optimized structures (e.g., the dark current blocking layer), the demonstrated QDIP displays promising characteristics, including a specific detectivity of 1.8×109 cm.Hz1/2/W and a quantum efficiency of 17%, which is about 5% higher than that of present n-type QDIPs. This study shows the promise of utilizing hole transitions for developing QDIPs.

Ag-Decorated Localized Surface Plasmon-Enhanced Ultraviolet Electroluminescence from ZnO Quantum Dot-Based/GaN Heterojunction Diodes by Optimizing MgO Interlayer Thickness.

PubMed

Chen, Cheng; Chen, Jingwen; Zhang, Jun; Wang, Shuai; Zhang, Wei; Liang, Renli; Dai, Jiangnan; Chen, Changqing

2016-12-01

We demonstrate the fabrication and characterization of localized surface plasmon (LSP)-enhanced n-ZnO quantum dot (QD)/MgO/p-GaN heterojunction light-emitting diodes (LEDs) by embedding Ag nanoparticles (Ag-NPs) into the ZnO/MgO interface. The maximum enhancement ration of the Ag-NP-decorated LEDs in electroluminescence (EL) is 4.3-fold by optimizing MgO electron-blocking layer thickness. The EL origination was investigated qualitatively in terms of photoluminescence (PL) results. Through analysis of the energy band structure of device and carrier transport mechanisms, it suggests that the EL enhancement is attributed to the increased rate of spontaneous emission and improved internal quantum efficiency induced by exciton-LSP coupling.

Ag-Decorated Localized Surface Plasmon-Enhanced Ultraviolet Electroluminescence from ZnO Quantum Dot-Based/GaN Heterojunction Diodes by Optimizing MgO Interlayer Thickness

NASA Astrophysics Data System (ADS)

Chen, Cheng; Chen, Jingwen; Zhang, Jun; Wang, Shuai; Zhang, Wei; Liang, Renli; Dai, Jiangnan; Chen, Changqing

2016-10-01

We demonstrate the fabrication and characterization of localized surface plasmon (LSP)-enhanced n-ZnO quantum dot (QD)/MgO/p-GaN heterojunction light-emitting diodes (LEDs) by embedding Ag nanoparticles (Ag-NPs) into the ZnO/MgO interface. The maximum enhancement ration of the Ag-NP-decorated LEDs in electroluminescence (EL) is 4.3-fold by optimizing MgO electron-blocking layer thickness. The EL origination was investigated qualitatively in terms of photoluminescence (PL) results. Through analysis of the energy band structure of device and carrier transport mechanisms, it suggests that the EL enhancement is attributed to the increased rate of spontaneous emission and improved internal quantum efficiency induced by exciton-LSP coupling.

13. A southeastward view of buildings #3 (on the right), ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

13. A southeastward view of buildings #3 (on the right), building #5 ( to the immediate left of building #3), and buildings #6-B (low building on the far left) and #6 ( to the immediate rear of #6-B). - American Chain & Cable Company, East Princess Street (400 Block), York, York County, PA

1. Historic American Buildings Survey E. W. Russell, Photographer, October ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

1. Historic American Buildings Survey E. W. Russell, Photographer, October 17, 1935 51-69 Government St. BLOCK OF BUILDINGS ON GOVERNMENT ST. (S. SIDE) BETWEEN WATER AND ROYAL STREETS - 51-69 Government Street (Commercial Building), Mobile, Mobile County, AL

Computational Design of Self-Assembling Protein Nanomaterials with Atomic Level Accuracy

DOE Office of Scientific and Technical Information (OSTI.GOV)

King, Neil P.; Sheffler, William; Sawaya, Michael R.

2015-09-17

We describe a general computational method for designing proteins that self-assemble to a desired symmetric architecture. Protein building blocks are docked together symmetrically to identify complementary packing arrangements, and low-energy protein-protein interfaces are then designed between the building blocks in order to drive self-assembly. We used trimeric protein building blocks to design a 24-subunit, 13-nm diameter complex with octahedral symmetry and a 12-subunit, 11-nm diameter complex with tetrahedral symmetry. The designed proteins assembled to the desired oligomeric states in solution, and the crystal structures of the complexes revealed that the resulting materials closely match the design models. The method canmore » be used to design a wide variety of self-assembling protein nanomaterials.« less

Expressivism, Relativism, and the Analytic Equivalence Test

PubMed Central

Frápolli, Maria J.; Villanueva, Neftalí

2015-01-01

The purpose of this paper is to show that, pace (Field, 2009), MacFarlane’s assessment relativism and expressivism should be sharply distinguished. We do so by arguing that relativism and expressivism exemplify two very different approaches to context-dependence. Relativism, on the one hand, shares with other contemporary approaches a bottom–up, building block, model, while expressivism is part of a different tradition, one that might include Lewis’ epistemic contextualism and Frege’s content individuation, with which it shares an organic model to deal with context-dependence. The building-block model and the organic model, and thus relativism and expressivism, are set apart with the aid of a particular test: only the building-block model is compatible with the idea that there might be analytically equivalent, and yet different, propositions. PMID:26635690

Fast and Facile Synthesis of 4-Nitrophenyl 2-Azidoethylcarbamate Derivatives from N-Fmoc-Protected α-Amino Acids as Activated Building Blocks for Urea Moiety-Containing Compound Library.

PubMed

Chen, Ying-Ying; Chang, Li-Te; Chen, Hung-Wei; Yang, Chia-Ying; Hsin, Ling-Wei

2017-03-13

A fast and facile synthesis of a series of 4-nitrophenyl 2-azidoethylcarbamate derivatives as activated urea building blocks was developed. The N-Fmoc-protected 2-aminoethyl mesylates derived from various commercially available N-Fmoc-protected α-amino acids, including those having functionalized side chains with acid-labile protective groups, were directly transformed into 4-nitrophenyl 2-azidoethylcarbamate derivatives in 1 h via a one-pot two-step reaction. These urea building blocks were utilized for the preparation of a series of urea moiety-containing mitoxantrone-amino acid conjugates in 75-92% yields and parallel solution-phase synthesis of a urea compound library consisted of 30 members in 38-70% total yields.

Mission building blocks for outer solar system exploration.

NASA Technical Reports Server (NTRS)

Herman, D.; Tarver, P.; Moore, J.

1973-01-01

Description of the technological building blocks required for exploring the outer planets with maximum scientific yields under stringent resource constraints. Two generic spacecraft types are considered: the Mariner and the Pioneer. Following a discussion of the outer planet mission constraints, the evolutionary development of spacecraft, probes, and propulsion building blocks is presented. Then, program genealogies are shown for Pioneer and Mariner missions and advanced propulsion systems to illustrate the soundness of a program based on spacecraft modification rather than on the development of new spacecraft for each mission. It is argued that, for minimum costs, technological advancement should occur in an evolutionary manner from mission to mission. While this strategy is likely to result in compromises on specific missions, the realization of the overall objectives calls for an advance commitment to the entire mission series.

2. EXTERIOR VIEW OF BUILDING 25B (TEST CHAMBER BUILDING) AND ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

2. EXTERIOR VIEW OF BUILDING 25B (TEST CHAMBER BUILDING) AND WIND TUNNEL, LOOKING NORTHWEST (1991). - Wright-Patterson Air Force Base, Area B, Buildings 25 & 24,10-foot & 20-foot Wind Tunnel Complex, Northeast side of block bounded by K, G, Third, & Fifth Streets, Dayton, Montgomery County, OH

Block Play: Practical Suggestions for Common Dilemmas

ERIC Educational Resources Information Center

Tunks, Karyn Wellhousen

2009-01-01

Learning materials and teaching methods used in early childhood classrooms have fluctuated greatly over the past century. However, one learning tool has stood the test of time: Wood building blocks, often called unit blocks, continue to be a source of pleasure and learning for young children at play. Wood blocks have the unique capacity to engage…

Air & Space Power Journal. Volume 21, Number 4, Winter 2007

DTIC Science & Technology

2007-01-01

all very well laid out, with buildings dotted neatly with trees and flowers . The people we met, whether the commandant, a sergeant, or a student...quick, precise employment; and solid as­ sessment of the enemy and population will produce positive, tangible results. Since the “ banana wars” of

75 FR 42481 - Requested Administrative Waiver of the Coastwise Trade Laws

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-21

... Administrative Waiver of the Coastwise Trade Laws AGENCY: Maritime Administration, DOT. ACTION: Invitation for public comments on a requested administrative waiver of the Coastwise Trade Laws for the vessel SEAFLYER... Administration (MARAD), is authorized to grant waivers of the U.S.-build requirement of the coastwise laws under...

76 FR 27237 - Airworthiness Directives; Empresa Brasileira de Aeronautica S.A. (EMBRAER) Model ERJ 170...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-11

... DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. FAA-2011... IGW Airplanes AGENCY: Federal Aviation Administration (FAA), Department of Transportation (DOT... person at the U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor...

75 FR 224 - Airworthiness Directives; Bombardier, Inc. (Type Certificate Previously Held by de Havilland, Inc...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-05

... DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. FAA-2009...-400 Series Airplanes AGENCY: Federal Aviation Administration (FAA), Department of Transportation (DOT....regulations.gov or in person at the U.S. Department of Transportation, Docket Operations, M-30, West Building...

75 FR 78937 - Airworthiness Directives; Honeywell International LTS101 Series Turboshaft Engines and LTP101...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-17

... Management Facility, U.S. Department of Transportation, 1200 New Jersey Avenue, SE., West Building Ground..., Aerospace Engineer, Los Angeles Aircraft Certification Office, FAA, Transport Airplane Directorate, 3960... an association, business, labor union, etc.). You may review the DOT's complete Privacy Act Statement...

77 FR 16914 - Airworthiness Directives; Airbus Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-23

... Transportation (DOT). ACTION: Final rule; request for comments. SUMMARY: We are adopting a new airworthiness... repetitive inspections for cracking at the fastener hole area just above stringer 28, of both left- and right... Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE...

78 FR 32353 - Airworthiness Directives; Bombardier, Inc. Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-30

... of Transportation (DOT). ACTION: Final Rule; Request for Comments. SUMMARY: We are adopting a new...) airplanes. This AD requires repetitive detailed inspections for cracking of the left-hand (LH) and right... Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE., Washington, DC 20590...

77 FR 24351 - Airworthiness Directives; Bombardier, Inc. Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-24

... of Transportation (DOT). ACTION: Final rule. SUMMARY: We are adopting a new airworthiness directive... and damage of the retract port flexible hose on the left and right MLG retraction actuator and... Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE...

77 FR 46937 - Airworthiness Directives; Airbus Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-07

... Transportation (DOT). ACTION: Final rule. SUMMARY: We are adopting a new airworthiness directive (AD) for certain... bearing attachment. This AD requires repetitive inspections for cracking of the left-hand (LH) and right... Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE., Washington, DC. FOR...

78 FR 78699 - Airworthiness Directives; Bell Helicopter Textron Canada Limited Helicopters

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-27

... Administration (FAA), DOT. ACTION: Final rule. SUMMARY: We are adopting a new airworthiness directive (AD) for...-4 helicopters with a certain tailboom upper left attachment fitting (fitting). This AD requires..., West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE., Washington, DC 20590. FOR FURTHER...

Understanding and controlling morphology formation in Langmuir-Blodgett block copolymer films using PS-P4VP and PS-P4VP/PDP.

PubMed

Perepichka, Iryna I; Lu, Qing; Badia, Antonella; Bazuin, C Geraldine

2013-04-09

This contribution offers a comprehensive understanding of the factors that govern the morphologies of Langmuir-Blodgett (LB) monolayers of amphiphilic diblock copolymers (BCs). This is achieved by a detailed investigation of a wide range of polystyrene-poly(4-vinyl pyridine) (PS-P4VP) block copolymers, in contrast to much more limited ranges in previous studies. Parameters that are varied include the block ratios (mainly for similar total molecular weights, occasionally other total molecular weights), the presence or not of 3-n-pentadecylphenol (PDP, usually equimolar with VP, with which it hydrogen bonds), the spreading solution concentration ("low" and "high"), and the LB technique (standard vs "solvent-assisted"). Our observations are compared with previously published results on other amphiphilic diblock copolymers, which had given rise to contradictory interpretations of morphology formation. Based on the accumulated results, we re-establish early literature conclusions that three main categories of LB block copolymer morphologies are obtained depending on the block ratio, termed planar, strand, and dot regimes. The block composition boundaries in terms of mol % block content are shown to be similar for all BCs having alkyl chain substituents on the hydrophilic block (such as PS-P4VP/PDP) and are shifted to higher values for BCs with no alkyl chain substituents (such as PS-P4VP). This is attributed to the higher surface area per repeat unit of the hydrophilic block monolayer on the water surface for the former, as supported by the onset and limiting areas of the Langmuir isotherms for the BCs in the dot regime. 2D phase diagrams are discussed in terms of relative effective surface areas of the two blocks. We identify and discuss how kinetic effects on morphology formation, which have been highlighted in more recent literature, are superposed on the compositional effects. The kinetic effects are shown to depend on the morphology regime, most strongly influencing the strand and, especially, planar regimes, where they give rise to a diversity of specific structures. Besides film dewetting mechanisms, which are different when occurring in structured versus unstructured films (the latter previously discussed in the literature), kinetic influences are discussed in terms of chain association dynamics leading to depletion effects that impact on growing aggregates. These depletion effects particularly manifest themselves in more dilute spreading solutions, with higher molecular weight polymers, and in composition regimes characterized by equilibrium degrees of aggregation that are effectively infinite. It is by understanding these various kinetic influences that the diversity of structures can be classified by the three main composition-dependent regimes.

Molecular docking sites designed for the generation of highly crystalline covalent organic frameworks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ascherl, Laura; Sick, Torben; Margraf, Johannes

Covalent organic frameworks (COFs) formed by connecting multidentate organic building blocks through covalent bonds provide a platform for designing multifunctional porous materials with atomic precision. As they are promising materials for applications in optoelectronics, they would benefit from a maximum degree of long-range order within the framework, which has remained a major challenge. We have developed a synthetic concept to allow consecutive COF sheets to lock in position during crystal growth, and thus minimize the occurrence of stacking faults and dislocations. Hereby, the three-dimensional conformation of propeller-shaped molecular building units was used to generate well-defined periodic docking sites, which guidedmore » the attachment of successive building blocks that, in turn, promoted long-range order during COF formation. This approach enables us to achieve a very high crystallinity for a series of COFs that comprise tri- and tetradentate central building blocks. We expect this strategy to be transferable to a broad range of customized COFs.« less

Emergent mechanics of biological structures

PubMed Central

Dumont, Sophie; Prakash, Manu

2014-01-01

Mechanical force organizes life at all scales, from molecules to cells and tissues. Although we have made remarkable progress unraveling the mechanics of life's individual building blocks, our understanding of how they give rise to the mechanics of larger-scale biological structures is still poor. Unlike the engineered macroscopic structures that we commonly build, biological structures are dynamic and self-organize: they sculpt themselves and change their own architecture, and they have structural building blocks that generate force and constantly come on and off. A description of such structures defies current traditional mechanical frameworks. It requires approaches that account for active force-generating parts and for the formation of spatial and temporal patterns utilizing a diverse array of building blocks. In this Perspective, we term this framework “emergent mechanics.” Through examples at molecular, cellular, and tissue scales, we highlight challenges and opportunities in quantitatively understanding the emergent mechanics of biological structures and the need for new conceptual frameworks and experimental tools on the way ahead. PMID:25368421

Molecular docking sites designed for the generation of highly crystalline covalent organic frameworks

NASA Astrophysics Data System (ADS)

Ascherl, Laura; Sick, Torben; Margraf, Johannes T.; Lapidus, Saul H.; Calik, Mona; Hettstedt, Christina; Karaghiosoff, Konstantin; Döblinger, Markus; Clark, Timothy; Chapman, Karena W.; Auras, Florian; Bein, Thomas

2016-04-01

Covalent organic frameworks (COFs) formed by connecting multidentate organic building blocks through covalent bonds provide a platform for designing multifunctional porous materials with atomic precision. As they are promising materials for applications in optoelectronics, they would benefit from a maximum degree of long-range order within the framework, which has remained a major challenge. We have developed a synthetic concept to allow consecutive COF sheets to lock in position during crystal growth, and thus minimize the occurrence of stacking faults and dislocations. Hereby, the three-dimensional conformation of propeller-shaped molecular building units was used to generate well-defined periodic docking sites, which guided the attachment of successive building blocks that, in turn, promoted long-range order during COF formation. This approach enables us to achieve a very high crystallinity for a series of COFs that comprise tri- and tetradentate central building blocks. We expect this strategy to be transferable to a broad range of customized COFs.

Elfin: An algorithm for the computational design of custom three-dimensional structures from modular repeat protein building blocks.

PubMed

Yeh, Chun-Ting; Brunette, T J; Baker, David; McIntosh-Smith, Simon; Parmeggiani, Fabio

2018-02-01

Computational protein design methods have enabled the design of novel protein structures, but they are often still limited to small proteins and symmetric systems. To expand the size of designable proteins while controlling the overall structure, we developed Elfin, a genetic algorithm for the design of novel proteins with custom shapes using structural building blocks derived from experimentally verified repeat proteins. By combining building blocks with compatible interfaces, it is possible to rapidly build non-symmetric large structures (>1000 amino acids) that match three-dimensional geometric descriptions provided by the user. A run time of about 20min on a laptop computer for a 3000 amino acid structure makes Elfin accessible to users with limited computational resources. Protein structures with controlled geometry will allow the systematic study of the effect of spatial arrangement of enzymes and signaling molecules, and provide new scaffolds for functional nanomaterials. Copyright © 2017 Elsevier Inc. All rights reserved.

The Influence of Building Block Play on Mathematics Achievement and Logical and Divergent Thinking in Italian Primary School Mathematics Classes

ERIC Educational Resources Information Center

Pirrone, Concetta; Tienken, Christopher H.; Pagano, Tatiana; Di Nuovo, Santo

2018-01-01

In an experimental study to explain the effect of structured Building Block Play with LEGO™ bricks on 6-year-old student mathematics achievement and in the areas of logical thinking, divergent thinking, nonverbal reasoning, and mental imagery, students in the experimental group scored significantly higher (p = 0.05) in mathematics achievement and…

Novel single photon sources for new generation of quantum communications

DTIC Science & Technology

2017-06-13

be used as building blocks for quantum cryptography and quantum key distribution There were numerous important achievements for the projects in the...single photon sources that will be used as build- ing blocks for quantum cryptography and quantum key distribution There were numerous im- portant...and enable absolutely secured information transfer between distant nodes – key prerequisite for quantum cryptography . Experiment: the experimental

Building Blocks for Transport-Class Hybrid and Turboelectric Vehicles

NASA Technical Reports Server (NTRS)

Jankovsky, Amy; Bowman, Cheryl; Jansen, Ralph

2016-01-01

NASA has been investing in research efforts to define potential vehicles that use hybrid and turboelectric propulsion to enable savings in fuel burn and carbon usage. This paper overviews the fundamental building blocks that have been derived from those studies and details what key performance parameters have been defined, what key ground and flight tests need to occur, and highlights progress toward each.

2016 Summer Series - Kenneth Cheung: Building Blocks for Aerospace Structures

NASA Image and Video Library

2016-06-16

Strong, ultra-lightweight materials are expected to play a key role in the design of future aircraft and space vehicles. Lower structural mass leads to improved performance, maneuverability, efficiency, range and payload capacity. Dr. Kenneth Cheung is developing cellular composite building blocks, or digital materials, to create transformable aerostructures. In his presentation, Dr. Cheung will discuss the implications of the digital materials and morphing structures.

Supramolecular Lego assembly towards three-dimensional multi-responsive hydrogels.

PubMed

Ma, Chunxin; Li, Tiefeng; Zhao, Qian; Yang, Xuxu; Wu, Jingjun; Luo, Yingwu; Xie, Tao

2014-08-27

Inspired by the assembly of Lego toys, hydrogel building blocks with heterogeneous responsiveness are assembled utilizing macroscopic supramolecular recognition as the adhesion force. The Lego hydrogel provides 3D transformation upon pH variation. After disassembly of the building blocks by changing the oxidation state, they can be re-assembled into a completely new shape. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

[Damage of modern building materials by microscopic fungi].

PubMed

Chuenko, A I; Karpenko, Iu V

2011-01-01

Resistance of three materials, produced on the basis of concrete compounds to the action of microscopic fungi, isolated from damaged living buildings, has been first investigated. It has been shown that samples of froth-block and thermoeffective block had low fungal resistance, in contrast to samples of cellular polystyrene concrete, which were resistant to fungal action, that can be associated with peculiarities of their component composition.

Building Blocks for Father Involvement: Building Block 1--Appreciating How Fathers Give Children a Head Start

ERIC Educational Resources Information Center

US Department of Health and Human Services, Head Start Bureau, 2004

2004-01-01

Nearly 30 years ago, leading child psychologist Michael E. Lamb reminded us that fathers are the "forgotten contributors to child development." Since then, much work has been done to explore the ways fathers uniquely contribute to the healthy development of their children. Scholars now know that boys and girls who grow up with an involved father,…

Highly crystalline covalent organic frameworks from flexible building blocks.

PubMed

Xu, Liqian; Ding, San-Yuan; Liu, Junmin; Sun, Junliang; Wang, Wei; Zheng, Qi-Yu

2016-03-28

Two novel 2D covalent organic frameworks (TPT-COF-1 and TPT-COF-2) were synthesized from the flexible 2,4,6-triaryloxy-1,3,5-triazine building blocks on a gram scale, which show high crystallinity and large surface area. The controllable formation of highly ordered frameworks is mainly attributed to the self-assembly Piedfort unit of 2,4,6-triaryloxy-1,3,5-triazine.

Functional Perfluoroalkyl Polyhedral Oligomeric Silsesquioxane (F-POSS): Building Blocks for Low Surface Energy Materials

DTIC Science & Technology

2010-10-21

Technical Paper 3. DATES COVERED (From - To) 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Functional Perfluoroalkyl Polyhedral Oligomeric Silsesquioxane (F...long chain fluorinated alkyl groups ranging from 6-12 carbon atoms in length. Herein, a disilanol perfluoroalkyl polyhedral oligomeric...FUNCTIONAL PERFLUOROALKYL POLYHEDRAL OLIGOMERIC SILSESQUIOXANES (F-POSS): BUILDING BLOCKS FOR LOW SURFACE ENERGY MATERIA LS Sean M Rami,.e:, Yvonne Dia

Cellular interaction influenced by surface modification strategies of gelatin-based nanoparticles.

PubMed

Tse, Wai Hei; Gyenis, Laszlo; Litchfield, David W; Zhang, Jin

2017-02-01

Theranostic applications of gelatin nanospheres require two major components, a method of detection and good biocompatibility. We characterized the response of UTA-6 human osteosarcoma cells to the introduction of functionalized 90 bloom-based gelatin nanospheres (158 ± 49 nm) modified with three elements in different order: (a) hybridization with cadmium-based quantum dots for optical detection, (b) bioconjugation with anti-human IgG FAB (anti-IgG) for cell targeting, with/without (c) capping with polyethylene glycol on the surface for enhanced biocompatibility. A one-pot process is developed for incorporating quantum dots and antibody with gelatin nanospheres. Path A of modifying gelatin nanospheres with quantum dots first followed by anti-IgG resulted in a significantly greater cellular viability than Path B with anti-IgG first followed by quantum dots. Capping with polyethylene glycol as the final step in modification yielded significantly opposing results with decreases in Path A and increases in Path B. Three-dimensional z-stacking fluorescent images of hybrid gelatin nanospheres with anti-IgG is observed to have an increase in cellular association. The observed results suggest the modification order for building hybrid nanospheres may have an impact on cellular response.

Expansion and improvements of the FORMA system for response and load analysis. Volume 1: Programming manual

NASA Technical Reports Server (NTRS)

Wohlen, R. L.

1976-01-01

Techniques are presented for the solution of structural dynamic systems on an electronic digital computer using FORMA (FORTRAN Matrix Analysis). FORMA is a library of subroutines coded in FORTRAN 4 for the efficient solution of structural dynamics problems. These subroutines are in the form of building blocks that can be put together to solve a large variety of structural dynamics problems. The obvious advantage of the building block approach is that programming and checkout time are limited to that required for putting the blocks together in the proper order.

Dual-mode MOS SOI nanoscale transistor serving as a building block for optical communication between blocks

NASA Astrophysics Data System (ADS)

Bendayan, Michael; Sabo, Roi; Zolberg, Roee; Mandelbaum, Yaakov; Chelly, Avraham; Karsenty, Avi

2017-02-01

We developed a new type of silicon MOSFET Quantum Well transistor, coupling both electronic and optical properties which should overcome the indirect silicon bandgap constraint, and serve as a future light emitting device in the range 0.8-2μm, as part of a new building block in integrated circuits allowing ultra-high speed processors. Such Quantum Well structure enables discrete energy levels for light recombination. Model and simulations of both optical and electric properties are presented pointing out the influence of the channel thickness and the drain voltage on the optical emission spectrum.

Micelle-templated, poly(lactic-co-glycolic acid) nanoparticles for hydrophobic drug delivery

PubMed Central

Nabar, Gauri M; Mahajan, Kalpesh D; Calhoun, Mark A; Duong, Anthony D; Souva, Matthew S; Xu, Jihong; Czeisler, Catherine; Puduvalli, Vinay K; Otero, José Javier; Wyslouzil, Barbara E; Winter, Jessica O

2018-01-01

Purpose Poly(lactic-co-glycolic acid) (PLGA) is widely used for drug delivery because of its biocompatibility, ability to solubilize a wide variety of drugs, and tunable degradation. However, achieving sub-100 nm nanoparticles (NPs), as might be desired for delivery via the enhanced permeability and retention effect, is extremely difficult via typical top-down emulsion approaches. Methods Here, we present a bottom-up synthesis method yielding PLGA/block copolymer hybrids (ie, “PolyDots”), consisting of hydrophobic PLGA chains entrapped within self-assembling poly(styrene-b-ethylene oxide) (PS-b-PEO) micelles. Results PolyDots exhibit average diameters <50 nm and lower polydispersity than conventional PLGA NPs. Drug encapsulation efficiencies of PolyDots match conventional PLGA NPs (ie, ~30%) and are greater than those obtained from PS-b-PEO micelles (ie, ~7%). Increasing the PLGA:PS-b-PEO weight ratio alters the drug release mechanism from chain relaxation to erosion controlled. PolyDots are taken up by model glioma cells via endocytotic mechanisms within 24 hours, providing a potential means for delivery to cytoplasm. PolyDots can be lyophilized with minimal change in morphology and encapsulant functionality, and can be produced at scale using electrospray. Conclusion Encapsulation of PLGA within micelles provides a bottom-up route for the synthesis of sub-100 nm PLGA-based nanocarriers with enhanced stability and drug-loading capacity, and tunable drug release, suitable for potential clinical applications. PMID:29391794

Photoresponsive liquid crystalline epoxy networks with shape memory behavior and dynamic ester bonds

DOE PAGES

Rios, Orlando; Chen, Jihua; Li, Yuzhan; ...

2016-06-01

Functional polymers are intelligent materials that can respond to a variety of external stimuli. However, these materials have not yet found widespread real world applications because of the difficulties in fabrication and the limited number of functional building blocks that can be incorporated into a material. Here, we demonstrate a simple route to incorporate three functional building blocks (azobenzene chromophores, liquid crystals, and dynamic covalent bonds) into an epoxy-based liquid crystalline network (LCN), in which an azobenzene-based epoxy monomer is polymerized with an aliphatic dicarboxylic acid to create exchangeable ester bonds that can be thermally activated. Lastly, all three functionalmore » building blocks exhibited good compatibility, and the resulting materials exhibits various photomechanical, shape memory, and self-healing properties because of the azobenzene molecules, liquid crystals, and dynamic ester bonds, respectively.« less

General synthesis of inorganic single-walled nanotubes

PubMed Central

Ni, Bing; Liu, Huiling; Wang, Peng-peng; He, Jie; Wang, Xun

2015-01-01

The single-walled nanotube (SWNT) is an interesting nanostructure for fundamental research and potential applications. However, very few inorganic SWNTs are available to date due to the lack of efficient fabrication methods. Here we synthesize four types of SWNT: sulfide; hydroxide; phosphate; and polyoxometalate. Each type of SWNT possesses essentially uniform diameters. Detailed studies illustrate that the formation of SWNTs is initiated by the self-coiling of the corresponding ultrathin nanostructure embryo/building blocks on the base of weak interactions between them, which is not limited to specific compounds or crystal structures. The interactions between building blocks can be modulated by varying the solvents used, thus multi-walled tubes can also be obtained. Our results reveal that the generalized synthesis of inorganic SWNTs can be achieved by the self-coiling of ultrathin building blocks under the proper weak interactions. PMID:26510862

In vitro imaging of cells using peptide-conjugated quantum dots

NASA Astrophysics Data System (ADS)

Ishikawa, Mitsuru; Biju, Vasudevan

2010-02-01

Efficient intracellular delivery of quantum dots (QDs) in living cells and elucidating the mechanism of the delivery are essential for advancing the applications of QDs to in vivo imaging and in vivo photodynamic therapy. Here, we demonstrate that clathrin-mediated endocytosis is the most dominant pathway for the delivery of peptide-conjugated QDs. We selected an insect neuropeptide, allatostatin (AST1), conjugated with CdSe-ZnS QDs, and investigated the delivery of the conjugate in living cells. We evaluated the contributions of clathrin-mediated endocytosis, receptormediated endocytosis, and charge-based cell penetration to the delivery of QD605-AST1 conjugates by flow cytometry and fluorescence video microscopy. The delivery was suppressed by ~57% in inhibiting phosphoinositide 3-kinase with wortmannin, which blocks the formation of clathrin-coated vesicles, and by ~45% in incubating the cells at 4°C. Also, we identified clathrin-mediated endocytosis by two-color experiment to find colocalization of QD560-labeled clathrin heavy-chain antibody and QD605-AST1. We further observed reduction of the galanin receptor-mediated delivery of QD605-AST1 by ~8% in blocking the cells with a galanin antagonist, and reduction of charge-based cell penetration delivery by ~30% in removing the positive charge in the peptide from arginine and suppressing the cell-surface negative charge from glycosaminoglycan.

Hierarchically Ordered Nanopatterns for Spatial Control of Biomolecules

PubMed Central

2015-01-01

The development and study of a benchtop, high-throughput, and inexpensive fabrication strategy to obtain hierarchical patterns of biomolecules with sub-50 nm resolution is presented. A diblock copolymer of polystyrene-b-poly(ethylene oxide), PS-b-PEO, is synthesized with biotin capping the PEO block and 4-bromostyrene copolymerized within the polystyrene block at 5 wt %. These two handles allow thin films of the block copolymer to be postfunctionalized with biotinylated biomolecules of interest and to obtain micropatterns of nanoscale-ordered films via photolithography. The design of this single polymer further allows access to two distinct superficial nanopatterns (lines and dots), where the PEO cylinders are oriented parallel or perpendicular to the substrate. Moreover, we present a strategy to obtain hierarchical mixed morphologies: a thin-film coating of cylinders both parallel and perpendicular to the substrate can be obtained by tuning the solvent annealing and irradiation conditions. PMID:25363506

Hierarchically Ordered Nanopatterns for Spatial Control of Biomolecules

DOE PAGES

Tran, Helen; Ronaldson, Kacey; Bailey, Nevette A.; ...

2014-11-04

We present the development and study of a benchtop, high-throughput, and inexpensive fabrication strategy to obtain hierarchical patterns of biomolecules with sub-50 nm resolution. A diblock copolymer of polystyrene-b-poly(ethylene oxide), PS-b-PEO, is synthesized with biotin capping the PEO block and 4-bromostyrene copolymerized within the polystyrene block at 5 wt %. These two handles allow thin films of the block copolymer to be postfunctionalized with biotinylated biomolecules of interest and to obtain micropatterns of nanoscale-ordered films via photolithography. The design of this single polymer further allows access to two distinct superficial nanopatterns (lines and dots), where the PEO cylinders are orientedmore » parallel or perpendicular to the substrate. Moreover, we present a strategy to obtain hierarchical mixed morphologies: a thin-film coating of cylinders both parallel and perpendicular to the substrate can be obtained by tuning the solvent annealing and irradiation conditions.« less

Incorporating residual temperature and specific humidity in predicting weather-dependent warm-season electricity consumption

NASA Astrophysics Data System (ADS)

Guan, Huade; Beecham, Simon; Xu, Hanqiu; Ingleton, Greg

2017-02-01

Climate warming and increasing variability challenges the electricity supply in warm seasons. A good quantitative representation of the relationship between warm-season electricity consumption and weather condition provides necessary information for long-term electricity planning and short-term electricity management. In this study, an extended version of cooling degree days (ECDD) is proposed for better characterisation of this relationship. The ECDD includes temperature, residual temperature and specific humidity effects. The residual temperature is introduced for the first time to reflect the building thermal inertia effect on electricity consumption. The study is based on the electricity consumption data of four multiple-street city blocks and three office buildings. It is found that the residual temperature effect is about 20% of the current-day temperature effect at the block scale, and increases with a large variation at the building scale. Investigation of this residual temperature effect provides insight to the influence of building designs and structures on electricity consumption. The specific humidity effect appears to be more important at the building scale than at the block scale. A building with high energy performance does not necessarily have low specific humidity dependence. The new ECDD better reflects the weather dependence of electricity consumption than the conventional CDD method.

7. Historic American Buildings Survey Verlin Berry, Photographer November 10, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

7. Historic American Buildings Survey Verlin Berry, Photographer November 10, 1977 FIRST FLOOR, VIEW OF PRESSED TIN CEILING WITH WOOD BLOCKING AT CROWN MOLDING - 111 West First Street (Commercial Building), Mishawaka, St. Joseph County, IN

Main-chain supramolecular block copolymers.

PubMed

Yang, Si Kyung; Ambade, Ashootosh V; Weck, Marcus

2011-01-01

Block copolymers are key building blocks for a variety of applications ranging from electronic devices to drug delivery. The material properties of block copolymers can be tuned and potentially improved by introducing noncovalent interactions in place of covalent linkages between polymeric blocks resulting in the formation of supramolecular block copolymers. Such materials combine the microphase separation behavior inherent to block copolymers with the responsiveness of supramolecular materials thereby affording dynamic and reversible materials. This tutorial review covers recent advances in main-chain supramolecular block copolymers and describes the design principles, synthetic approaches, advantages, and potential applications.

GENERAL VIEW OF TYPE HB54s (BUILDINGS T1088 TO T1093) & ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

GENERAL VIEW OF TYPE HB-54s (BUILDINGS T-1088 TO T-1093) & CONVERTED TYPE HB-54S (BUILDINGS T-1094 TO T-1096), LOOKING SOUTHWEST; BUILDING T-1088 AT LEFT, BUILDING T-1096 AT RIGHT - Fort McCoy, Building No. T-1096, South side of South Ninth Avenue, Block 10, Sparta, Monroe County, WI

Flexible Fabrication of Shape-Controlled Collagen Building Blocks for Self-Assembly of 3D Microtissues.

PubMed

Zhang, Xu; Meng, Zhaoxu; Ma, Jingyun; Shi, Yang; Xu, Hui; Lykkemark, Simon; Qin, Jianhua

2015-08-12

Creating artificial tissue-like structures that possess the functionality, specificity, and architecture of native tissues remains a big challenge. A new and straightforward strategy for generating shape-controlled collagen building blocks with a well-defined architecture is presented, which can be used for self-assembly of complex 3D microtissues. Collagen blocks with tunable geometries are controllably produced and released via a membrane-templated microdevice. The formation of functional microtissues by embedding tissue-specific cells into collagen blocks with expression of specific proteins is described. The spontaneous self-assembly of cell-laden collagen blocks into organized tissue constructs with predetermined configurations is demonstrated, which are largely driven by the synergistic effects of cell-cell and cell-matrix interactions. This new strategy would open up new avenues for the study of tissue/organ morphogenesis, and tissue engineering applications. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

An easy access to 2-Amino-5,6-dihydro-3H-pyrimidin-4-one building blocks: the reaction under conventional and microwave conditions.

PubMed

Ostras, Konstantin S; Gorobets, Nikolay Yu; Desenko, Sergey M; Musatov, Vladimir I

2006-08-01

A new one-stage fast multicomponent synthesis of title compounds leads to products in 21-55% isolated yields under both conventional and microwave conditions. The primary amino group in the building blocks can be easily acylated by various usual electophilic agents that can be utilized in the synthesis of diverse heterocylic compounds libraries.

[Spatial distribution characteristics of urban potential population in Shenyang City based on QuickBird image and GIS].

PubMed

Li, Jun-Ying; Hu, Yuan-Man; Chen, Wei; Liu, Miao; Hu, Jian-Bo; Zhong, Qiao-Lin; Lu, Ning

2012-06-01

Population is the most active factor affecting city development. To understand the distribution characteristics of urban population is of significance for making city policy decisions and for optimizing the layout of various urban infrastructures. In this paper, the information of the residential buildings in Shenyang urban area was extracted from the QuickBird remote sensing images, and the spatial distribution characteristics of the population within the Third-Ring Road of the City were analyzed, according to the social and economic statistics data. In 2010, the population density in different types of residential buildings within the Third-Ring Road of the City decreased in the order of high-storey block, mixed block, mixed garden, old multi-storey building, high-storey garden, multi-storey block, multi-storey garden, villa block, shanty, and villa garden. The vacancy rate of the buildings within the Third-Ring Road was more than 30%, meaning that the real estate market was seriously overstocked. Among the five Districts of Shenyang City, Shenhe District had the highest potential population density, while Tiexi District and Dadong District had a lower one. The gravity center of the City and its five Districts was also analyzed, which could provide basic information for locating commercial facilities and planning city infrastructure.

Wrapping cytochrome c around single-wall carbon nanotube: engineered nanohybrid building blocks for infrared detection at high quantum efficiency

PubMed Central

Gong, Youpin; Liu, Qingfeng; Wilt, Jamie Samantha; Gong, Maogang; Ren, Shenqiang; Wu, Judy

2015-01-01

Biomolecule cytochrome c (Cty c), a small molecule of a chain of amino acids with extraordinary electron transport, was helically wrapped around a semiconductive single-wall carbon nanotube (s-SWCNT) to form a molecular building block for uncooled infrared detection with two uniquely designed functionalities: exciton dissociation to free charge carriers at the heterojunction formed on the s-SWCNT/Cty c interface and charge transport along the electron conducting chain of Cty c (acceptor) and hole conducting channel through s-SWCNT (donor). Such a design aims at addressing the long-standing challenges in exciton dissociation and charge transport in an SWCNT network, which have bottlenecked development of photonic SWCNT-based infrared detectors. Using these building blocks, uncooled s-SWCNT/Cyt c thin film infrared detectors were synthesized and shown to have extraordinary photoresponsivity up to 0.77 A W−1 due to a high external quantum efficiency (EQE) in exceeding 90%, which represents a more than two orders of magnitude enhancement than the best previously reported on CNT-based infrared detectors with EQE of only 1.72%. From a broad perspective, this work on novel s-SWCNT/Cyt c nanohybrid infrared detectors has developed a successful platform of engineered carbon nanotube/biomolecule building blocks with superior properties for optoelectronic applications. PMID:26066737

Wrapping cytochrome c around single-wall carbon nanotube: engineered nanohybrid building blocks for infrared detection at high quantum efficiency.

PubMed

Gong, Youpin; Liu, Qingfeng; Wilt, Jamie Samantha; Gong, Maogang; Ren, Shenqiang; Wu, Judy

2015-06-11

Biomolecule cytochrome c (Cty c), a small molecule of a chain of amino acids with extraordinary electron transport, was helically wrapped around a semiconductive single-wall carbon nanotube (s-SWCNT) to form a molecular building block for uncooled infrared detection with two uniquely designed functionalities: exciton dissociation to free charge carriers at the heterojunction formed on the s-SWCNT/Cty c interface and charge transport along the electron conducting chain of Cty c (acceptor) and hole conducting channel through s-SWCNT (donor). Such a design aims at addressing the long-standing challenges in exciton dissociation and charge transport in an SWCNT network, which have bottlenecked development of photonic SWCNT-based infrared detectors. Using these building blocks, uncooled s-SWCNT/Cyt c thin film infrared detectors were synthesized and shown to have extraordinary photoresponsivity up to 0.77 A W(-1) due to a high external quantum efficiency (EQE) in exceeding 90%, which represents a more than two orders of magnitude enhancement than the best previously reported on CNT-based infrared detectors with EQE of only 1.72%. From a broad perspective, this work on novel s-SWCNT/Cyt c nanohybrid infrared detectors has developed a successful platform of engineered carbon nanotube/biomolecule building blocks with superior properties for optoelectronic applications.

Intrinsic Folding Proclivities in Cyclic β-Peptide Building Blocks: Configuration and Heteroatom Effects Analyzed by Conformer-Selective Spectroscopy and Quantum Chemistry.

PubMed

Alauddin, Mohammad; Gloaguen, Eric; Brenner, Valérie; Tardivel, Benjamin; Mons, Michel; Zehnacker-Rentien, Anne; Declerck, Valérie; Aitken, David J

2015-11-09

This work describes the use of conformer-selective laser spectroscopy following supersonic expansion to probe the local folding proclivities of four-membered ring cyclic β-amino acid building blocks. Emphasis is placed on stereochemical effects as well as on the structural changes induced by the replacement of a carbon atom of the cycle by a nitrogen atom. The amide A IR spectra are obtained and interpreted with the help of quantum chemistry structure calculations. Results provide evidence that the building block with a trans-substituted cyclobutane ring has a predilection to form strong C8 hydrogen bonds. Nitrogen-atom substitution in the ring induces the formation of the hydrazino turn, with a related but distinct hydrogen-bonding network: the structure is best viewed as a bifurcated C8/C5 bond with the N heteroatom lone electron pair playing a significant acceptor role, which supports recent observations on the hydrazino turn structure in solution. Surprisingly, this study shows that the cis-substituted cyclobutane ring derivative also gives rise predominantly to a C8 hydrogen bond, although weaker than in the two former cases, a feature that is not often encountered for this building block. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Microzonation of seismic risk in a low-rise Latin American city based on the macroseismic evaluation of the vulnerability of residential buildings: Colima city, México

NASA Astrophysics Data System (ADS)

Zobin, V. M.; Cruz-Bravo, A. A.; Ventura-Ramírez, F.

2010-06-01

A macroseismic methodology of seismic risk microzonation in a low-rise city based on the vulnerability of residential buildings is proposed and applied to Colima city, Mexico. The seismic risk microzonation for Colima consists of two elements: the mapping of residential blocks according to their vulnerability level and the calculation of an expert-opinion based damage probability matrix (DPM) for a given level of earthquake intensity and a given type of residential block. A specified exposure time to the seismic risk for this zonation is equal to the interval between two destructive earthquakes. The damage probability matrices were calculated for three types of urban buildings and five types of residential blocks in Colima. It was shown that only 9% of 1409 residential blocks are able to resist to the Modify Mercalli (MM) intensity VII and VIII earthquakes without significant damage. The proposed DPM-2007 is in good accordance with the experimental damage curves based on the macroseismic evaluation of 3332 residential buildings in Colima that was carried out after the 21 January 2003 intensity MM VII earthquake. This methodology and the calculated PDM-2007 curves may be applied also to seismic risk microzonation for many low-rise cities in Latin America, Asia, and Africa.

Advanced space system concepts and their orbital support needs (1980 - 2000). Volume 4: Detailed data. Part 2: Program plans and common support needs (a study of the commonality of space vehicle applications to future national needs

NASA Technical Reports Server (NTRS)

Bekey, I.; Mayer, H. L.; Wolfe, M. G.

1976-01-01

The methodology of alternate world future scenarios is utilized for selecting a plausible, though not advocated, set of future scenarios each of which results in a program plan appropriate for the respective environment. Each such program plan gives rise to different building block and technology requirements, which are analyzed for common need between the NASA and the DoD for each of the alternate world scenarios. An essentially invariant set of system, building block, and technology development plans is presented at the conclusion, intended to allow protection of most of the options for system concepts regardless of what the actual future world environment turns out to be. Thus, building block and technology needs are derived which support: (1) each specific world scenario; (2) all the world scenarios identified in this study; or (3) generalized scenarios applicable to almost any future environment. The output included in this volume consists of the building blocks, i.e.: transportation vehicles, orbital support vehicles, and orbital support facilities; the technology required to support the program plans; identification of their features which could support the DoD and NASA in common; and a complete discussion of the planning methodology.

Making Your Own Hollow Blocks. What We Make. Science and Technology Education in Philippine Society.

ERIC Educational Resources Information Center

Philippines Univ., Quezon City. Inst. for Science and Mathematics Education Development.

The procedures needed to make hollow blocks from palay hull, sawdust, soil, or sand are outlined in this module. Also outlined are the procedures needed to construct the wooden molds used to make the blocks. The hollow blocks can be used in building a one story house where the roof does not rest on the hollow block wall, an additional room to the…

Statistical interpretation of transient current power-law decay in colloidal quantum dot arrays

NASA Astrophysics Data System (ADS)

Sibatov, R. T.

2011-08-01

A new statistical model of the charge transport in colloidal quantum dot arrays is proposed. It takes into account Coulomb blockade forbidding multiple occupancy of nanocrystals and the influence of energetic disorder of interdot space. The model explains power-law current transients and the presence of the memory effect. The fractional differential analogue of the Ohm law is found phenomenologically for nanocrystal arrays. The model combines ideas that were considered as conflicting by other authors: the Scher-Montroll idea about the power-law distribution of waiting times in localized states for disordered semiconductors is applied taking into account Coulomb blockade; Novikov's condition about the asymptotic power-law distribution of time intervals between successful current pulses in conduction channels is fulfilled; and the carrier injection blocking predicted by Ginger and Greenham (2000 J. Appl. Phys. 87 1361) takes place.

An Optimized Three-Level Design of Decoder Based on Nanoscale Quantum-Dot Cellular Automata

NASA Astrophysics Data System (ADS)

Seyedi, Saeid; Navimipour, Nima Jafari

2018-03-01

Quantum-dot Cellular Automata (QCA) has been potentially considered as a supersede to Complementary Metal-Oxide-Semiconductor (CMOS) because of its inherent advantages. Many QCA-based logic circuits with smaller feature size, improved operating frequency, and lower power consumption than CMOS have been offered. This technology works based on electron relations inside quantum-dots. Due to the importance of designing an optimized decoder in any digital circuit, in this paper, we design, implement and simulate a new 2-to-4 decoder based on QCA with low delay, area, and complexity. The logic functionality of the 2-to-4 decoder is verified using the QCADesigner tool. The results have shown that the proposed QCA-based decoder has high performance in terms of a number of cells, covered area, and time delay. Due to the lower clock pulse frequency, the proposed 2-to-4 decoder is helpful for building QCA-based sequential digital circuits with high performance.

Mapping from Space - Ontology Based Map Production Using Satellite Imageries

NASA Astrophysics Data System (ADS)

Asefpour Vakilian, A.; Momeni, M.

2013-09-01

Determination of the maximum ability for feature extraction from satellite imageries based on ontology procedure using cartographic feature determination is the main objective of this research. Therefore, a special ontology has been developed to extract maximum volume of information available in different high resolution satellite imageries and compare them to the map information layers required in each specific scale due to unified specification for surveying and mapping. ontology seeks to provide an explicit and comprehensive classification of entities in all sphere of being. This study proposes a new method for automatic maximum map feature extraction and reconstruction of high resolution satellite images. For example, in order to extract building blocks to produce 1 : 5000 scale and smaller maps, the road networks located around the building blocks should be determined. Thus, a new building index has been developed based on concepts obtained from ontology. Building blocks have been extracted with completeness about 83%. Then, road networks have been extracted and reconstructed to create a uniform network with less discontinuity on it. In this case, building blocks have been extracted with proper performance and the false positive value from confusion matrix was reduced by about 7%. Results showed that vegetation cover and water features have been extracted completely (100%) and about 71% of limits have been extracted. Also, the proposed method in this article had the ability to produce a map with largest scale possible from any multi spectral high resolution satellite imagery equal to or smaller than 1 : 5000.

Mapping from Space - Ontology Based Map Production Using Satellite Imageries

NASA Astrophysics Data System (ADS)

Asefpour Vakilian, A.; Momeni, M.

2013-09-01

Determination of the maximum ability for feature extraction from satellite imageries based on ontology procedure using cartographic feature determination is the main objective of this research. Therefore, a special ontology has been developed to extract maximum volume of information available in different high resolution satellite imageries and compare them to the map information layers required in each specific scale due to unified specification for surveying and mapping. ontology seeks to provide an explicit and comprehensive classification of entities in all sphere of being. This study proposes a new method for automatic maximum map feature extraction and reconstruction of high resolution satellite images. For example, in order to extract building blocks to produce 1 : 5000 scale and smaller maps, the road networks located around the building blocks should be determined. Thus, a new building index has been developed based on concepts obtained from ontology. Building blocks have been extracted with completeness about 83 %. Then, road networks have been extracted and reconstructed to create a uniform network with less discontinuity on it. In this case, building blocks have been extracted with proper performance and the false positive value from confusion matrix was reduced by about 7 %. Results showed that vegetation cover and water features have been extracted completely (100 %) and about 71 % of limits have been extracted. Also, the proposed method in this article had the ability to produce a map with largest scale possible from any multi spectral high resolution satellite imagery equal to or smaller than 1 : 5000.

Automatic Generation of Issue Maps: Structured, Interactive Outputs for Complex Information Needs

DTIC Science & Technology

2012-09-01

much can result in behaviour similar to the shortest-path chains. 24 Ronald Goldman Neil Lewis Judge Lance Ito 1 1 1 1 1 0 0 0 1 1 1 1 1 1 1 jury...Connecting the Dots has also been explored in non-textual domains. The authors of [ Heath et al., 2010] propose building graphs, called Image Webs, to...could imagine a metro map summarizing a dataset of medical records. 2. Images: In [ Heath et al., 2010], Heath et al build graphs called Image Webs to rep

Intelligent transportation systems Professional Capacity Building Program : ITS training & education needs assessment baseline : a review and synthesis of thirteen prior studies, field interviews, and a summary assessment of ITS needs

DOT National Transportation Integrated Search

1997-12-01

Successful deployment, operation, and management of Intelligent Transportation Systems (ITS) requires a new breed of transportation professionals, according to research, extensive outreach, and information gathered to date. The U.S. DOT has responded...

Effective utilization of disadvantaged business enterprises (DBE) in alternative delivery projects: strategies and resources to support the achievement of DBE goals : Georgia DOT research project 14-42 : final report.

DOT National Transportation Integrated Search

2016-04-01

This synthesis is a comprehensive review of the best knowledge and practices for stimulating effective : utilization of Disadvantaged Business Enterprises (DBE) in the procurement and execution of : transportation projects, using design-build and oth...

75 FR 7949 - Airworthiness Directives; Extra Flugzeugproduktions- und Vertriebs- GmbH Models EA-300/200 and EA...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-23

... DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. FAA-2009... Airplanes AGENCY: Federal Aviation Administration (FAA), Department of Transportation (DOT). ACTION: Final... Facility, U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12...

77 FR 3382 - Airworthiness Directives; Agusta S.p.A. Helicopters

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-24

... Transportation (DOT). ACTION: Final rule; request for comments. SUMMARY: We are adopting a new airworthiness... fatigue crack found in the left elevator assembly along the riveting of the upper skin to the fourth rib... Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE...

76 FR 8607 - Airworthiness Directives; The Cessna Aircraft Company Model 750 Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-15

... Administration (FAA), DOT. ACTION: Final rule. SUMMARY: We are adopting a new airworthiness directive (AD) for... auxiliary power unit (APU) generator and the left and right engine direct current (DC) generators, and... Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590. FOR FURTHER...

17. A southward view of buildings #6B and #6 in ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

17. A southward view of buildings #6-B and #6 in the left background and buildings #5 (center) and #3 (right of center). - American Chain & Cable Company, East Princess Street (400 Block), York, York County, PA

Streambank Protection Guidelines,

DTIC Science & Technology

1983-10-01

the types of rubble suitable for dumping on an eroding bank include broken pavement, bricks, building blocks , slag , and quarry waste. Large flat slabs...not provide any long-termn protection. blocks , and house brick. I rfbiae omrilgbo akt Completed gabion revetment made from prefabricated baskets...prevent pressure buildup that could cause revetment failure. BLOCKS . Precast cellular blocks can be ypi i .,, p no- , ,,, ,hag ,.,.,,,,t

Rockfall vulnerability assessment for masonry buildings

NASA Astrophysics Data System (ADS)

Mavrouli, Olga

2015-04-01

The methodologies for the quantitative risk assessment vary in function of the application scale and the available data. For fragmental rockfalls, risk calculation requires data for the expected damage of the exposed elements due to potential rock block impacts with a range of trajectories, magnitudes and intensities. Although the procedures for the quantification of the rock block characteristics in terms of magnitude-frequency relationships are well established, there are few methodologies for the calculation of the vulnerability, and these are usually empirical or judgmental. The response of buildings to rock block impacts using analytical methods has been mainly realised so far for reinforced concrete buildings, and some fragility curves have been calculated with the results, indicating the potential damage for a range of rock block characteristics. Masonry buildings, as a common structural typology in mountainous areas, are in many cases impacted by rock blocks during rockfalls. Their response presents some peculiarities in comparison with reinforced-concrete structures given the non-homogeneity and variability of the compound materials (blocks and mortar), their orthotropy, low strength in tension, the statically indeterminate load-bearing system and the non-monolithic connections. To this purpose, analytical procedures which are specifically adapted to masonry structures should be used for the evaluation of the expected damage due to rock impacts. In this contribution we discuss the application of the analytical approach for the assessment of the expected damage in rockfall prone areas and the simulation assumptions that can be made concerning the materials, geometry, loading and the relevant simplifications. The amount of uncertainties introduced during their analytical simulation is high due to the dispersion of the data for material mechanical properties and the construction techniques and quality and thus a probabilistic assessment is suggested. The random nature of the rockfall as far as it concerns the magnitude and the intensity of the rock blocks can also be introduced using parametric analyses.

Design and synthesis of unnatural heparosan and chondroitin building blocks

PubMed Central

Bera, Smritilekha; Linhardt, Robert J.

2011-01-01

Triazole linked heparosan and chondroitin disaccharide and tetrasaccharide building blocks were synthesized in a stereoselective manner by applying a very efficient Copper Catalyzed Azide-Alkyne Cycloadditions (CuAAC) reaction of appropriately substituted azido-glucuronic acid and propargyluted N-acetyl glucosamine and N-acetyl galactosamine derivative respectively. The resulting suitably substituted tetrasaccharide analogs can be easily converted into azide and alkyne unit for further synthesis of higher oligosaccharide analogs. PMID:21438620

PBF Reactor Building (PER620). After lowering reactor vessel onto blocks, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

PBF Reactor Building (PER-620). After lowering reactor vessel onto blocks, it is rolled on logs into PBF. Metal framework under vessel is handling device. Various penetrations in reactor bottom were for instrumentation, poison injection, drains. Large one, below center "manhole" was for primary coolant. Photographer: Larry Page. Date: February 13, 1970. INEEL negative no. 70-736 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

11. VIEW OF INTERIOR OF BUILDING 220 FIRST FLOOR, CELL ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

11. VIEW OF INTERIOR OF BUILDING 220 FIRST FLOOR, CELL BLOCK 'A' (SOLITARY CONFINEMENT CELL BLOCK), TYPICAL SOLITARY CONFINEMENT CELL. THE CELL SHOWN IN CENTER OF PHOTO, HAS A 2-1/2' THICK STEEL DOOR. THE CELL SHOWN IN THE LEFT OF PHOTO, HAS A 3/4' DIAMETER IRON GRILLE DOOR. - U.S. Naval Base, Pearl Harbor, Brig, Neville Way near Ninth Street at Marine Barracks, Pearl City, Honolulu County, HI

Advanced information processing system: Local system services

NASA Technical Reports Server (NTRS)

Burkhardt, Laura; Alger, Linda; Whittredge, Roy; Stasiowski, Peter

1989-01-01

The Advanced Information Processing System (AIPS) is a multi-computer architecture composed of hardware and software building blocks that can be configured to meet a broad range of application requirements. The hardware building blocks are fault-tolerant, general-purpose computers, fault-and damage-tolerant networks (both computer and input/output), and interfaces between the networks and the computers. The software building blocks are the major software functions: local system services, input/output, system services, inter-computer system services, and the system manager. The foundation of the local system services is an operating system with the functions required for a traditional real-time multi-tasking computer, such as task scheduling, inter-task communication, memory management, interrupt handling, and time maintenance. Resting on this foundation are the redundancy management functions necessary in a redundant computer and the status reporting functions required for an operator interface. The functional requirements, functional design and detailed specifications for all the local system services are documented.

Effector-Triggered Self-Replication in Coupled Subsystems.

PubMed

Komáromy, Dávid; Tezcan, Meniz; Schaeffer, Gaël; Marić, Ivana; Otto, Sijbren

2017-11-13

In living systems processes like genome duplication and cell division are carefully synchronized through subsystem coupling. If we are to create life de novo, similar control over essential processes such as self-replication need to be developed. Here we report that coupling two dynamic combinatorial subsystems, featuring two separate building blocks, enables effector-mediated control over self-replication. The subsystem based on the first building block shows only self-replication, whereas that based on the second one is solely responsive toward a specific external effector molecule. Mixing the subsystems arrests replication until the effector molecule is added, resulting in the formation of a host-effector complex and the liberation of the building block that subsequently engages in self-replication. The onset, rate and extent of self-replication is controlled by the amount of effector present. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Laboratory testing of a building envelope segment based on cellular concrete

NASA Astrophysics Data System (ADS)

Fořt, Jan; Pavlík, Zbyšek; Černý, Robert

2016-07-01

Hygrothermal performance of a building envelope based on cellular concrete blocks is studied in the paper. Simultaneously, the strain fields induced by the heat and moisture changes are monitored. The studied wall is exposed to the climatic load corresponding to the winter climatic conditions of the moderate year for Prague. The winter climatic exposure is chosen in order to simulate the critical conditions of the building structure from the point of view of material performance and temperature and humidity loading. The evaluation of hygrothermal performance of a researched wall is done on the basis of relative humidity and temperature profiles measured along the cross section of the cellular concrete blocks. Strain gauges are fixed on the wall surface in expected orientation of the blocks expansion. The obtained results show a good hygrothermal function of the analyzed cellular concrete wall and its insignificant strain.

Synthesis of Triamino Acid Building Blocks with Different Lipophilicities

PubMed Central

Maity, Jyotirmoy; Honcharenko, Dmytro; Strömberg, Roger

2015-01-01

To obtain different amino acids with varying lipophilicity and that can carry up to three positive charges we have developed a number of new triamino acid building blocks. One set of building blocks was achieved by aminoethyl extension, via reductive amination, of the side chain of ortnithine, diaminopropanoic and diaminobutanoic acid. A second set of triamino acids with the aminoethyl extension having hydrocarbon side chains was synthesized from diaminobutanoic acid. The aldehydes needed for the extension by reductive amination were synthesized from the corresponding Fmoc-L-2-amino fatty acids in two steps. Reductive amination of these compounds with Boc-L-Dab-OH gave the C4-C8 alkyl-branched triamino acids. All triamino acids were subsequently Boc-protected at the formed secondary amine to make the monomers appropriate for the N-terminus position when performing Fmoc-based solid-phase peptide synthesis. PMID:25876040

SU-F-T-517: Determining the Tissue Equivalence of a Brass Mesh Bolus in a Reconstructed Chest Wall Irradiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shekel, E; Epstein, D; Levin, D

2016-06-15

Purpose: To determine the tissue equivalence of a brass mesh bolus (RPD) in the setting of a reconstructed chest wall irradiation Methods: We measured breast skin dose delivered by a tangential field plan on an anthropomorphic phantom using Mosfet and nanoDot (Landauer) dosimeters in five different locations on the breast. We also measured skin dose using no bolus, 5mm and 10 mm superflab bolus. In the Eclipse treatment planning system (Varian, Palo Alto, CA) we calculated skin dose for different bolus thicknesses, ranging from 0 to 10 mm, in order to evaluate which calculation best matches the brass mesh measurements,more » as the brass mesh cannot be simulated due to artefacts.Finally, we measured depth dose behavior with the brass mesh bolus to verify that the bolus does not affect the dose to the breast itself beyond the build-up region. Results: Mosfet and nanoDot measurements were consistent with each other.As expected, skin dose measurements with no bolus had the least agreement with Eclipse calculation, while measurements for 5 and 10 mm agreed well with the calculation despite the difficulty in conforming superflab bolus to the breast contour. For the brass mesh the best agreement was for 3 mm bolus Eclipse calculation. For Mosfets, the average measurement was 90.8% of the expected dose, and for nanoDots 88.33% compared to 83.34%, 88.64% and 93.94% (2,3 and 5 mm bolus calculation respectively).The brass mesh bolus increased skin dose by approximately 25% but there was no dose increase beyond the build-up region. Conclusion: Brass mesh bolus is most equivalent to a 3 mm bolus, and does not affect the dose beyond the build-up region. The brass mesh cannot be directly calculated in Eclipse, hence a 3mm bolus calculation is a good reflection of the dose response to the brass mesh bolus.« less

Tandem Repeat Proteins Inspired By Squid Ring Teeth

NASA Astrophysics Data System (ADS)

Pena-Francesch, Abdon

Proteins are large biomolecules consisting of long chains of amino acids that hierarchically assemble into complex structures, and provide a variety of building blocks for biological materials. The repetition of structural building blocks is a natural evolutionary strategy for increasing the complexity and stability of protein structures. However, the relationship between amino acid sequence, structure, and material properties of protein systems remains unclear due to the lack of control over the protein sequence and the intricacies of the assembly process. In order to investigate the repetition of protein building blocks, a recently discovered protein from squids is examined as an ideal protein system. Squid ring teeth are predatory appendages located inside the suction cups that provide a strong grasp of prey, and are solely composed of a group of proteins with tandem repetition of building blocks. The objective of this thesis is the understanding of sequence, structure and property relationship in repetitive protein materials inspired in squid ring teeth for the first time. Specifically, this work focuses on squid-inspired structural proteins with tandem repeat units in their sequence (i.e., repetition of alternating building blocks) that are physically cross-linked via beta-sheet structures. The research work presented here tests the hypothesis that, in these systems, increasing the number of building blocks in the polypeptide chain decreases the protein network defects and improves the material properties. Hence, the sequence, nanostructure, and properties (thermal, mechanical, and conducting) of tandem repeat squid-inspired protein materials are examined. Spectroscopic structural analysis, advanced materials characterization, and entropic elasticity theory are combined to elucidate the structure and material properties of these repetitive proteins. This approach is applied not only to native squid proteins but also to squid-inspired synthetic polypeptides that allow for a fine control of the sequence and network morphology. The results provided in this work establish a clear dependence between the repetitive building blocks, the network morphology, and the properties of squid-inspired repetitive protein materials. Increasing the number of tandem repeat units in SRT-inspired proteins led to more effective protein networks with superior properties. Through increasing tandem repetition and optimization of network morphology, highly efficient protein materials capable of withstanding deformations up to 400% of their original length, with MPa-GPa modulus, high energy absorption (50 MJ m-3), peak proton conductivity of 3.7 mS cm-1 (at pH 7, highest reported to date for biological materials), and peak thermal conductivity of 1.4 W m-1 K -1 (which exceeds that of most polymer materials) were developed. These findings introduce new design rules in the engineering of proteins based on tandem repetition and morphology control, and provide a novel framework for tailoring and optimizing the properties of protein-based materials.

Molecular Clusters: Nanoscale Building Blocks for Solid-State Materials.

PubMed

Pinkard, Andrew; Champsaur, Anouck M; Roy, Xavier

2018-04-17

The programmed assembly of nanoscale building blocks into multicomponent hierarchical structures is a powerful strategy for the bottom-up construction of functional materials. To develop this concept, our team has explored the use of molecular clusters as superatomic building blocks to fabricate new classes of materials. The library of molecular clusters is rich with exciting properties, including diverse functionalization, redox activity, and magnetic ordering, so the resulting cluster-assembled solids, which we term superatomic crystals (SACs), hold the promise of high tunability, atomic precision, and robust architectures among a diverse range of other material properties. Molecular clusters have only seldom been used as precursors for functional materials. Our team has been at the forefront of new developments in this exciting research area, and this Account focuses on our progress toward designing materials from cluster-based precursors. In particular, this Account discusses (1) the design and synthesis of molecular cluster superatomic building blocks, (2) their self-assembly into SACs, and (3) their resulting collective properties. The set of molecular clusters discussed herein is diverse, with different cluster cores and ligand arrangements to create an impressive array of solids. The cluster cores include octahedral M 6 E 8 and cubane M 4 E 4 (M = metal; E = chalcogen), which are typically passivated by a shell of supporting ligands, a feature upon which we have expanded upon by designing and synthesizing more exotic ligands that can be used to direct solid-state assembly. Building from this library, we have designed whole families of binary SACs where the building blocks are held together through electrostatic, covalent, or van der Waals interactions. Using single-crystal X-ray diffraction (SCXRD) to determine the atomic structure, a remarkable range of compositional variability is accessible. We can also use this technique, in tandem with vibrational spectroscopy, to ascertain features about the constituent superatomic building blocks, such as the charge of the cluster cores, by analysis of bond distances from the SCXRD data. The combination of atomic precision and intercluster interactions in these SACs produces novel collective properties, including tunable electrical transport, crystalline thermal conductivity, and ferromagnetism. In addition, we have developed a synthetic strategy to insert redox-active guests into the superstructure of SACs via single-crystal-to-single-crystal intercalation. This intercalation process allows us to tune the optical and electrical transport properties of the superatomic crystal host. These properties are explored using a host of techniques, including Raman spectroscopy, SQUID magnetometry, electrical transport measurements, electronic absorption spectroscopy, differential scanning calorimetry, and frequency-domain thermoreflectance. Superatomic crystals have proven to be both robust and tunable, representing a new method of materials design and architecture. This Account demonstrates how precisely controlling the structure and properties of nanoscale building blocks is key in developing the next generation of functional materials; several examples are discussed and detailed herein.

Building a Case for Blocks as Kindergarten Mathematics Learning Tools

ERIC Educational Resources Information Center

Kinzer, Cathy; Gerhardt, Kacie; Coca, Nicole

2016-01-01

Kindergarteners need access to blocks as thinking tools to develop, model, test, and articulate their mathematical ideas. In the current educational landscape, resources such as blocks are being pushed to the side and being replaced by procedural worksheets and academic "seat time" in order to address standards. Mathematics research…

Revisit Pattern Blocks to Develop Rational Number Sense

ERIC Educational Resources Information Center

Champion, Joe; Wheeler, Ann

2014-01-01

Pattern blocks are inexpensive wooden, foam, or plastic manipulatives developed in the 1960s to help students build an understanding of shapes, proportions, equivalence, and fractions (EDC 1968). The colorful collection of basic shapes in classic pattern block kits affords opportunities for amazing puzzle-like problem-solving tasks and for…

Atlas-guided volumetric diffuse optical tomography enhanced by generalized linear model analysis to image risk decision-making responses in young adults.

PubMed

Lin, Zi-Jing; Li, Lin; Cazzell, Mary; Liu, Hanli

2014-08-01

Diffuse optical tomography (DOT) is a variant of functional near infrared spectroscopy and has the capability of mapping or reconstructing three dimensional (3D) hemodynamic changes due to brain activity. Common methods used in DOT image analysis to define brain activation have limitations because the selection of activation period is relatively subjective. General linear model (GLM)-based analysis can overcome this limitation. In this study, we combine the atlas-guided 3D DOT image reconstruction with GLM-based analysis (i.e., voxel-wise GLM analysis) to investigate the brain activity that is associated with risk decision-making processes. Risk decision-making is an important cognitive process and thus is an essential topic in the field of neuroscience. The Balloon Analog Risk Task (BART) is a valid experimental model and has been commonly used to assess human risk-taking actions and tendencies while facing risks. We have used the BART paradigm with a blocked design to investigate brain activations in the prefrontal and frontal cortical areas during decision-making from 37 human participants (22 males and 15 females). Voxel-wise GLM analysis was performed after a human brain atlas template and a depth compensation algorithm were combined to form atlas-guided DOT images. In this work, we wish to demonstrate the excellence of using voxel-wise GLM analysis with DOT to image and study cognitive functions in response to risk decision-making. Results have shown significant hemodynamic changes in the dorsal lateral prefrontal cortex (DLPFC) during the active-choice mode and a different activation pattern between genders; these findings correlate well with published literature in functional magnetic resonance imaging (fMRI) and fNIRS studies. Copyright © 2014 The Authors. Human Brain Mapping Published by Wiley Periodicals, Inc.

Magneto-conductance fingerprints of purely quantum states in the open quantum dot limit

NASA Astrophysics Data System (ADS)

Mendoza, Michel; Ujevic, Sebastian

2012-06-01

We present quantum magneto-conductance simulations, at the quantum low energy condition, to study the open quantum dot limit. The longitudinal conductance G(E,B) of spinless and non-interacting electrons is mapped as a function of the magnetic field B and the energy E of the electrons. The quantum dot linked to the semi-infinite leads is tuned by quantum point contacts of variable width w. We analyze the transition from a quantum wire to an open quantum dot and then to an effective closed system. The transition, as a function of w, occurs in the following sequence: evolution of quasi-Landau levels to Fano resonances and quasi-bound states between the quasi-Landau levels, followed by the formation of crossings that evolve to anti-crossings inside the quasi-Landau level region. After that, Fano resonances are created between the quasi-Landau states with the final generation of resonant tunneling peaks. By comparing the G(E,B) maps, we identify the closed and open-like limits of the system as a function of the applied magnetic field. These results were used to build quantum openness diagrams G(w,B). Also, these maps allow us to determine the w-limit value from which we can qualitatively relate the closed system properties to the open one. The above analysis can be used to identify single spinless particle effects in experimental measurements of the open quantum dot limit.

Two new hybrid molybdenum arsenate derivative constructed from [As2Mo6O26]6- building: Synthesis, structural characterization and photocatalysis property

NASA Astrophysics Data System (ADS)

Zhang, Xiao; Luo, Xuan; Duan, Yuanling; Huang, Yanping; Zhang, Nanxi; Zhao, Liyan; Wu, Jie

2017-08-01

Two new inorganic-organic hybrid materials [Cu(enMe)2]2{(As2Mo6O26) [Cu(enMe)2]}·4H2O (1) and [As2Mo6(OH)2O24][Cu(H2O)2(phen)]2 (2) (enMe = 1,2'-propanediamine, phen = 1,10'-phenanthroline) based on [As2Mo6O26]6- building blocks, denoted as [As2Mo6], have been obtained by hydrothermal methods. 1 shows a 1-D straight chain structure constructed form [As2Mo6] building blocks and [Cu(enMe)2] complexes, and then extended to 3-D supramolecular network by lattice water via hydrogen bonds interactions. 2 exhibits a new 1-D covalent ribbon with large rectangular grids formed from [As2Mo6] building blocks connected by [Cu(H2O)2(phen)] complexes, then extended into 3-D supramolecular network via hydrogen bonds and π···π interactions. In additional, the photocatalytic activity for methylene blue degradation under visible-light irradiation of 2 was investigated.

Mechanisms of optical orientation of an individual Mn2+ ion spin in a II-VI quantum dot

NASA Astrophysics Data System (ADS)

Smoleński, T.; Cywiński, Ł.; Kossacki, P.

2018-02-01

We provide a theoretical description of the optical orientation of a single Mn2+ ion spin under quasi-resonant excitation demonstrated experimentally by Goryca et al (2009 Phys. Rev. Lett. 103 087401). We build and analyze a hierarchy of models by starting with the simplest assumptions (transfer of perfectly spin-polarized excitons from Mn-free dot to the other dot containing a single Mn2+ spin, followed by radiative recombination) and subsequently adding more features, such as spin relaxation of electrons and holes. Particular attention is paid to the role of the influx of the dark excitons and the process of biexciton formation, which are shown to contribute significantly to the orientation process in the quasi-resonant excitation case. Analyzed scenarios show how multiple features of the excitonic complexes in magnetically-doped quantum dots, such as the values of exchange integrals, spin relaxation times, etc, lead to a plethora of optical orientation processes, characterized by distinct dependencies on light polarization and laser intensity, and occurring on distinct timescales. Comparison with experimental data shows that the correct description of the optical orientation mechanism requires taking into account Mn2+ spin-flip processes occurring not only when the exciton is already in the orbital ground state of the light-emitting dot, but also those that happen during the exciton transfer from high-energy states to the ground state. Inspired by the experimental results on energy relaxation of electrons and holes in nonmagnetic dots, we focus on the process of biexciton creation allowed by mutual spin-flip of an electron and the Mn2+ spin, and we show that by including it in the model, we obtain good qualitative and quantitative agreement with the experimental data on quasi-resonantly driven Mn2+ spin orientation.

Self-assembly: Misfits unite

NASA Astrophysics Data System (ADS)

Grason, Gregory M.

2017-12-01

The spontaneous assembly of particulate or molecular 'building blocks' into larger architectures underlies structure formation in many biological and synthetic materials. Shape frustration of ill-fitting blocks holds a surprising key to more regular assemblies.

Door in west wall of the center block, positioned near ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Door in west wall of the center block, positioned near the detached kitchen/bake house building. - Lazaretto Quarantine Station, Wanamaker Avenue and East Second Street, Essington, Delaware County, PA

Thomas Leps Internship Abstract

NASA Technical Reports Server (NTRS)

Leps, Thomas

2016-01-01

An optical navigation system is being flown as the backup system to the primary Deep Space Network telemetry for navigation and guidance purposes on Orion. This is required to ensure Orion can recover from a loss of communication, which would simultaneously cause a loss of DSN telemetry. Images taken of the Moon and Earth are used to give range and position information to the navigation computer for trajectory calculations and maneuver execution. To get telemetry data from these images, the size and location of the moon need to be calculated with high accuracy and precision. The reentry envelope for the Orion EM-1 mission requires the centroid and radius of the moon images to be determined within 1/3 of a pixel 3 sigma. In order to ensure this accuracy and precision can be attained, I was tasked with building precise dot grid images for camera calibration as well as building a hardware in the loop test stand for flight software and hardware proofing. To calibrate the Op-Nav camera a dot grid is imaged with the camera, the error between the image dot location and the actual dot location can be used to build a distortion map of the camera and lens system so that images can be fixed to display truth locations. To build the dot grid images I used the Electro Optics Lab optical bench Bright Object Simulator System, and gimbal. The gimbal was slewed to a series of elevations and azimuths. An image of the collimated single point light source was then taken at each position. After a series of 99 images were taken at different locations the single light spots were extracted from each image and added to a composite image containing all 99 points. During the development of these grids it was noticed that an intermittent error in the artificial "star" locations occurred. Prior to the summer this error was attributed to the gimbal having glitches in it's pointing direction and was going to be replaced, however after further examining the issue I determined it to be a software issue. I have since narrowed the likely source of the error down to a Software Development Kit released by the camera supplier PixeLink. I have since developed a workaround in order to build star grids for calibration until the software bug can be isolated and fixed. I was also tasked with building a Hardware in the Loop test stand in order to test the full Op-Nav system. A 4k screen displays simulated Lunar and Terrestrial images from a possible Orion trajectory. These images are then projected through a collimator and then captured with an Op-Nav camera controlled by an Intel NUC computer running flight software. The flight software then analyzes the images to determine attitude and position, this data is then reconstructed into a trajectory and matched to the simulated trajectory in order to determine the accuracy of the attitude and position estimates. In order for the system to work it needs to be precisely and accurately aligned. I developed an alignment procedure that allows the screen, collimator and camera to be squared, centered and collinear with each other within a micron spatially and 5 arcseconds in rotation. I also designed a rigid mount for the screen that was machined on site in Building 10 by another intern. While I was working in the EOL we received a $500k Orion startracker for alignment procedure testing. Due to my prior experience in electronics development, as an ancillary duty, I was tasked with building the cables required to operate and power the startracker. If any errors are made building these cables the startracker would be destroyed, I was honored that the director of the lab entrusted such a critical component with me. This internship has cemented my view on public space exploration. I always preferred public sector to privatization because, as a scientist, the most interesting aspects of space for me are not necessarily the most profitable. I was concerned that the public sector was faltering however, and that in order to improve human space exploration I would be forced into private sector. I now know that, at least at JSC, human spaceflight is still progressing, and exciting work is still being done. I am now actively seeking employment at JSC after I complete my Ph.D and have met with my branch chiefs and mentor to discuss transitioning to a grad Co-op position.

A crown-like heterometallic unit as the building block for a 3D In-Ge-S framework.

PubMed

Han, Xiaohui; Wang, Zhenqing; Xu, Jin; Liu, Dan; Wang, Cheng

2015-12-14

Supertetrahedral clusters are the most common building blocks in constructing Group 13/14/16 microporous metal chalcogenide materials while other types of clusters are yet scarcely explored. Herein, a new crown-like building unit [In3Ge3S16] has been obtained. The units assemble into a 3D framework [C6H14NO]4[In6Ge3S17]·1.5H2O (1) via a dual-connection mode and a SrSi2 (srs)-type topology could be achieved by treating each unit as a tri-connected node.

Self-assembled InAs/InP quantum dots and quantum dashes: Material structures and devices

NASA Astrophysics Data System (ADS)

Khan, Mohammed Zahed Mustafa; Ng, Tien Khee; Ooi, Boon S.

2014-11-01

The advances in lasers, electronic and photonic integrated circuits (EPIC), optical interconnects as well as the modulation techniques allow the present day society to embrace the convenience of broadband, high speed internet and mobile network connectivity. However, the steep increase in energy demand and bandwidth requirement calls for further innovation in ultra-compact EPIC technologies. In the optical domain, advancement in the laser technologies beyond the current quantum well (Qwell) based laser technologies are already taking place and presenting very promising results. Homogeneously grown quantum dot (Qdot) lasers and optical amplifiers, can serve in the future energy saving information and communication technologies (ICT) as the work-horse for transmitting and amplifying information through optical fiber. The encouraging results in the zero-dimensional (0D) structures emitting at 980 nm, in the form of vertical cavity surface emitting laser (VCSEL), are already operational at low threshold current density and capable of 40 Gbps error-free transmission at 108 fJ/bit. Subsequent achievements for lasers and amplifiers operating in the O-, C-, L-, U-bands, and beyond will eventually lay the foundation for green ICT. On the hand, the inhomogeneously grown quasi 0D quantum dash (Qdash) lasers are brilliant solutions for potential broadband connectivity in server farms or access network. A single broadband Qdash laser operating in the stimulated emission mode can replace tens of discrete narrow-band lasers in dense wavelength division multiplexing (DWDM) transmission thereby further saving energy, cost and footprint. We herein reviewed the1 progress of both Qdots and Qdash devices, based on the InAs/InGaAlAs/InP and InAs/InGaAsP/InP material systems, from the angles of growth and device performance. In particular, we discussed the progress in lasers, semiconductor optical amplifiers (SOA), mode locked lasers, and superluminescent diodes, which are the building blocks of EPIC and ICT. Alternatively, these optical sources are potential candidates for other multi-disciplinary field applications.

Factors influencing epitaxial growth of three-dimensional Ge quantum dot crystals on pit-patterned Si substrate.

PubMed

Ma, Y J; Zhong, Z; Yang, X J; Fan, Y L; Jiang, Z M

2013-01-11

We investigated the molecular beam epitaxy growth of three-dimensional (3D) Ge quantum dot crystals (QDCs) on periodically pit-patterned Si substrates. A series of factors influencing the growth of QDCs were investigated in detail and the optimized growth conditions were found. The growth of the Si buffer layer and the first quantum dot (QD) layer play a key role in the growth of QDCs. The pit facet inclination angle decreased with increasing buffer layer thickness, and its optimized value was found to be around 21°, ensuring that all the QDs in the first layer nucleate within the pits. A large Ge deposition amount in the first QD layer favors strain build-up by QDs, size uniformity of QDs and hence periodicity of the strain distribution; a thin Si spacer layer favors strain correlation along the growth direction; both effects contribute to the vertical ordering of the QDCs. Results obtained by atomic force microscopy and cross-sectional transmission electron microscopy showed that 3D ordering was achieved in the Ge QDCs with the highest ever areal dot density of 1.2 × 10(10) cm(-2), and that the lateral and the vertical interdot spacing were ~10 and ~2.5 nm, respectively.

Coherent manipulation of a Si/SiGe-based singlet-triplet qubit

NASA Astrophysics Data System (ADS)

Gyure, Mark

2012-02-01

Electrically defined silicon-based qubits are expected to show improved quantum memory characteristics in comparison to GaAs-based devices due to reduced hyperfine interactions with nuclear spins. Silicon-based qubit devices have proved more challenging to build than their GaAs-based counterparts, but recently several groups have reported substantial progress in single-qubit initialization, measurement, and coherent operation. We report [1] coherent control of electron spins in two coupled quantum dots in an undoped Si/SiGe heterostructure, forming two levels of a singlet-triplet qubit. We measure a nuclei-induced T2^* of 360 ns, an increase over similar measurements in GaAs-based quantum dots by nearly two orders of magnitude. We also describe the results from detailed modeling of our materials and devices that show this value for T2^* is consistent with theoretical expectations for our estimated dot sizes and a natural abundance of ^29Si. The views and conclusions contained in this document are those of the authors and should not be interpreted as representing the official policies, either expressly or implied, of the United States Department of Defense or the U.S. Government. Approved for public release, distribution unlimited.[4pt] [1] B. M. Maune et al., ``Coherent Singlet-Triplet Oscillations in a Silicon-based Double Quantum Dot,'' accepted by Nature.

PERTS: A Prototyping Environment for Real-Time Systems

NASA Technical Reports Server (NTRS)

Liu, Jane W. S.; Lin, Kwei-Jay; Liu, C. L.

1993-01-01

PERTS is a prototyping environment for real-time systems. It is being built incrementally and will contain basic building blocks of operating systems for time-critical applications, tools, and performance models for the analysis, evaluation and measurement of real-time systems and a simulation/emulation environment. It is designed to support the use and evaluation of new design approaches, experimentations with alternative system building blocks, and the analysis and performance profiling of prototype real-time systems.

VLSI architecture for a Reed-Solomon decoder

NASA Technical Reports Server (NTRS)

Hsu, In-Shek (Inventor); Truong, Trieu-Kie (Inventor)

1992-01-01

A basic single-chip building block for a Reed-Solomon (RS) decoder system is partitioned into a plurality of sections, the first of which consists of a plurality of syndrome subcells each of which contains identical standard-basis finite-field multipliers that are programmable between 10 and 8 bit operation. A desired number of basic building blocks may be assembled to provide a RS decoder of any syndrome subcell size that is programmable between 10 and 8 bit operation.

Exploring endoperoxides as a new entry for the synthesis of branched azasugars

PubMed Central

Domeyer, Svenja; Bjerregaard, Mark; Johansson, Henrik

2017-01-01

A new class of nitrogen-containing endoperoxides were synthesised by a photochemical [4 + 2]-cycloaddition between a diene and singlet oxygen. The endoperoxides were dihydroxylated and protected to provide a series of endoperoxide building blocks for organic synthesis, with potential use as precursors for the synthesis of branched azasugars. Preliminary exploration of the chemistry of these building blocks provided access to a variety of derivatives including tetrahydrofurans, epoxides and protected amino-tetraols. PMID:28487758

Cascaded VLSI neural network architecture for on-line learning

NASA Technical Reports Server (NTRS)

Thakoor, Anilkumar P. (Inventor); Duong, Tuan A. (Inventor); Daud, Taher (Inventor)

1992-01-01

High-speed, analog, fully-parallel, and asynchronous building blocks are cascaded for larger sizes and enhanced resolution. A hardware compatible algorithm permits hardware-in-the-loop learning despite limited weight resolution. A computation intensive feature classification application was demonstrated with this flexible hardware and new algorithm at high speed. This result indicates that these building block chips can be embedded as an application specific coprocessor for solving real world problems at extremely high data rates.

Spontaneous self-assembly of a giant spherical metal-oxide Keplerate: addition of one building block induces "immediate" formation of the complementary one from a constitutional dynamic library.

PubMed

Schäffer, Christian; Todea, Ana Maria; Gouzerh, Pierre; Müller, Achim

2012-01-11

The addition of dinuclear {Mo(2)} units to a dynamic library containing molybdates results in the spontaneous self-assembly of a giant spherical metal-oxide species of the type {(Mo)Mo(5)}(12){Mo(2)}(30) while the required pentagonal {(Mo)Mo(5)} building blocks are "immediately" formed. This journal is © The Royal Society of Chemistry 2012

Fluorescence enhancement through the formation of a single-layer two-dimensional supramolecular organic framework and its application in highly selective recognition of picric acid.

PubMed

Zhang, Ying; Zhan, Tian-Guang; Zhou, Tian-You; Qi, Qiao-Yan; Xu, Xiao-Na; Zhao, Xin

2016-06-18

A two-dimensional (2D) supramolecular organic framework (SOF) has been constructed through the co-assembly of a triphenylamine-based building block and cucurbit[8]uril (CB[8]). Fluorescence turn-on of the non-emissive building block was observed upon the formation of the 2D SOF, which displayed highly selective and sensitive recognition of picric acid over a variety of nitroaromatics.

Cascaded VLSI neural network architecture for on-line learning

NASA Technical Reports Server (NTRS)

Duong, Tuan A. (Inventor); Daud, Taher (Inventor); Thakoor, Anilkumar P. (Inventor)

1995-01-01

High-speed, analog, fully-parallel and asynchronous building blocks are cascaded for larger sizes and enhanced resolution. A hardware-compatible algorithm permits hardware-in-the-loop learning despite limited weight resolution. A comparison-intensive feature classification application has been demonstrated with this flexible hardware and new algorithm at high speed. This result indicates that these building block chips can be embedded as application-specific-coprocessors for solving real-world problems at extremely high data rates.

Building blocks for the development of an interface for high-throughput thin layer chromatography/ambient mass spectrometric analysis: a green methodology.

PubMed

Cheng, Sy-Chyi; Huang, Min-Zong; Wu, Li-Chieh; Chou, Chih-Chiang; Cheng, Chu-Nian; Jhang, Siou-Sian; Shiea, Jentaie

2012-07-17

Interfacing thin layer chromatography (TLC) with ambient mass spectrometry (AMS) has been an important area of analytical chemistry because of its capability to rapidly separate and characterize the chemical compounds. In this study, we have developed a high-throughput TLC-AMS system using building blocks to deal, deliver, and collect the TLC plate through an electrospray-assisted laser desorption ionization (ELDI) source. This is the first demonstration of the use of building blocks to construct and test the TLC-MS interfacing system. With the advantages of being readily available, cheap, reusable, and extremely easy to modify without consuming any material or reagent, the use of building blocks to develop the TLC-AMS interface is undoubtedly a green methodology. The TLC plate delivery system consists of a storage box, plate dealing component, conveyer, light sensor, and plate collecting box. During a TLC-AMS analysis, the TLC plate was sent to the conveyer from a stack of TLC plates placed in the storage box. As the TLC plate passed through the ELDI source, the chemical compounds separated on the plate would be desorbed by laser desorption and subsequently postionized by electrospray ionization. The samples, including a mixture of synthetic dyes and extracts of pharmaceutical drugs, were analyzed to demonstrate the capability of this TLC-ELDI/MS system for high-throughput analysis.

Mussel-inspired nano-building block assemblies for mimicking extracellular matrix microenvironments with multiple functions.

PubMed

Wang, Zhenming; Jia, Zhanrong; Jiang, Yanan; Li, Pengfei; Han, Lu; Lu, Xiong; Ren, Fuzeng; Wang, Kefeng; Yuan, Huiping

2017-08-03

The assembly of nano-building blocks is an effective way to produce artificial extracellular matrix microenvironments with hierarchical micro/nano structures. However, it is hard to assemble different types of nano-building blocks, to form composite coatings with multiple functions, by traditional layer-by-layer (LbL) self-assembly methods. Inspired by the mussel adhesion mechanism, we developed polydopamine (PDA)-decorated bovine serum albumin microspheres (BSA-MS) and nano-hydroxyapatite (nano-HA), and assembled them to form bioactive coatings with micro/nano structures encapsulating bone morphogenetic protein-2 (BMP-2). First, PDA-decorated nano-HA (nano-pHA) was obtained by oxidative polymerization of dopamine on nano-HA. Second, BMP-2-encapsulated BSA microspheres were prepared through desolvation, and then were also decorated by PDA (pBSA-MS). Finally, the nano-pHA and pBSA-MS were assembled using the adhesive properties of PDA. Bone marrow stromal cell cultures and in vivo implantation, showed that the pHA/pBSA (BMP-2) coatings can promote cell adhesion, proliferation, and benefited for osteoinductivity. PDA decoration was also applied to assemble various functional nanoparticles, such as nano-HA, polystyrene, and Fe 3 O 4 nanoparticles. In summary, this study provides a novel strategy for the assembly of biofunctional nano-building blocks, which surpasses traditional LbL self-assembly of polyelectrolytes, and can find broad applications in bioactive agents delivery or multi-functional coatings.

Key Topics for High-Lift Research: A Joint Wind Tunnel/Flight Test Approach

NASA Technical Reports Server (NTRS)

Fisher, David; Thomas, Flint O.; Nelson, Robert C.

1996-01-01

Future high-lift systems must achieve improved aerodynamic performance with simpler designs that involve fewer elements and reduced maintenance costs. To expeditiously achieve this, reliable CFD design tools are required. The development of useful CFD-based design tools for high lift systems requires increased attention to unresolved flow physics issues. The complex flow field over any multi-element airfoil may be broken down into certain generic component flows which are termed high-lift building block flows. In this report a broad spectrum of key flow field physics issues relevant to the design of improved high lift systems are considered. It is demonstrated that in-flight experiments utilizing the NASA Dryden Flight Test Fixture (which is essentially an instrumented ventral fin) carried on an F-15B support aircraft can provide a novel and cost effective method by which both Reynolds and Mach number effects associated with specific high lift building block flows can be investigated. These in-flight high lift building block flow experiments are most effective when performed in conjunction with coordinated ground based wind tunnel experiments in low speed facilities. For illustrative purposes three specific examples of in-flight high lift building block flow experiments capable of yielding a high payoff are described. The report concludes with a description of a joint wind tunnel/flight test approach to high lift aerodynamics research.

Single-trabecula building block for large-scale finite element models of cancellous bone.

PubMed

Dagan, D; Be'ery, M; Gefen, A

2004-07-01

Recent development of high-resolution imaging of cancellous bone allows finite element (FE) analysis of bone tissue stresses and strains in individual trabeculae. However, specimen-specific stress/strain analyses can include effects of anatomical variations and local damage that can bias the interpretation of the results from individual specimens with respect to large populations. This study developed a standard (generic) 'building-block' of a trabecula for large-scale FE models. Being parametric and based on statistics of dimensions of ovine trabeculae, this building block can be scaled for trabecular thickness and length and be used in commercial or custom-made FE codes to construct generic, large-scale FE models of bone, using less computer power than that currently required to reproduce the accurate micro-architecture of trabecular bone. Orthogonal lattices constructed with this building block, after it was scaled to trabeculae of the human proximal femur, provided apparent elastic moduli of approximately 150 MPa, in good agreement with experimental data for the stiffness of cancellous bone from this site. Likewise, lattices with thinner, osteoporotic-like trabeculae could predict a reduction of approximately 30% in the apparent elastic modulus, as reported in experimental studies of osteoporotic femora. Based on these comparisons, it is concluded that the single-trabecula element developed in the present study is well-suited for representing cancellous bone in large-scale generic FE simulations.

Monitoring Thermal Performance of Hollow Bricks with Different Cavity Fillers in Difference Climate Conditions

NASA Astrophysics Data System (ADS)

Pavlík, Zbyšek; Jerman, Miloš; Fořt, Jan; Černý, Robert

2015-03-01

Hollow brick blocks have found widespread use in the building industry during the last decades. The increasing requirements to the thermal insulation properties of building envelopes given by the national standards in Europe led the brick producers to reduce the production of common solid bricks. Brick blocks with more or less complex systems of internal cavities replaced the traditional bricks and became dominant on the building ceramics market. However, contrary to the solid bricks where the thermal conductivity can easily be measured by standard methods, the complex geometry of hollow brick blocks makes the application of common techniques impossible. In this paper, a steady-state technique utilizing a system of two climatic chambers separated by a connecting tunnel for sample positioning is used for the determination of the thermal conductivity, thermal resistance, and thermal transmittance ( U value) of hollow bricks with the cavities filled by air, two different types of mineral wool, polystyrene balls, and foam polyurethane. The particular brick block is provided with the necessary temperature- and heat-flux sensors and thermally insulated in the tunnel. In the climatic chambers, different temperatures are set. After steady-state conditions are established in the measuring system, the effective thermal properties of the brick block are calculated using the measured data. Experimental results show that the best results are achieved with hydrophilic mineral wool as a cavity filler; the worst performance exhibits the brick block with air-filled cavities.

78 FR 64179 - Hours of Service of Drivers; Amendment of the 30-Minute Rest Break Requirement

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-28

... Flexibility, Small Business, and Job Creation (76 FR 3827). As explained above, promulgation of this final..., Room W12-140, DOT Building, 1200 New Jersey Avenue SE., Washington, DC 20590. You may view the docket..., Federal Motor Carrier Safety Administration, U.S. Department of Transportation, 1200 New Jersey Avenue SE...

75 FR 75878 - Airworthiness Directives; Airbus Model A318-111 and A318-112 Airplanes and Model A319, A320, and...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-07

... DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. FAA-2008... Airplanes AGENCY: Federal Aviation Administration (FAA), Department of Transportation (DOT). ACTION: Final... Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE...

75 FR 8465 - Airworthiness Directives; McDonnell Douglas Corporation Model MD-90-30 Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-25

... Administration (FAA), DOT. ACTION: Final rule. SUMMARY: We are adopting a new airworthiness directive (AD) for... frames at stations 883, 902, 924, 943, and 962, left and right sides, and corrective actions if necessary.... Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New...

Fluorometric immunoassay for human serum albumin based on its inhibitory effect on the immunoaggregation of quantum dots with silver nanoparticles

NASA Astrophysics Data System (ADS)

Marukhyan, Seda S.; Gasparyan, Vardan K.

2017-02-01

Quantitative determination of HSA was conducted by competitive immunoassay. Inhibition of aggregation of antibody conjugated quantum dots (QD) with albumin conjugated silver nanoparticles (AgNPs) in the presence of HSA was conducted. If antibody-loaded CdSe QDs aggregate with HSA-coated silver nanoparticles the distance between the two kinds of nanoparticles will be reduced enough to cause fluorescence resonance energy transfer (FRET). In this case the yellow fluorescence of the Ab-QDs is quenched. However if HSA (antigen) is added to the Ab-QDs their surface will be blocked and they cannot aggregate any longer with the HSA-AgNPs. Hence, fluorescence will not be quenched. The drop of the intensity of fluorescence (peaking at 570 nm) is inversely correlated with the concentration of HSA in the sample. The method allows to determine HSA in the 30-600 ng·mL-1 concentration range.

Full counting statistics and shot noise of cotunneling in quantum dots and single-molecule transistors

NASA Astrophysics Data System (ADS)

Kaasbjerg, Kristen; Belzig, Wolfgang

2015-06-01

We develop a conceptually simple scheme based on a master-equation approach to evaluate the full-counting statistics (FCS) of elastic and inelastic off-resonant tunneling (cotunneling) in quantum dots (QDs) and molecules. We demonstrate the method by showing that it reproduces known results for the FCS and shot noise in the cotunneling regime. For a QD with an excited state, we obtain an analytic expression for the cumulant generating function (CGF) taking into account elastic and inelastic cotunneling. From the CGF we find that the shot noise above the inelastic threshold in the cotunneling regime is inherently super-Poissonian when external relaxation is weak. Furthermore, a complete picture of the shot noise across the different transport regimes is given. In the case where the excited state is a blocking state, strongly enhanced shot noise is predicted both in the resonant and cotunneling regimes.

Pure ultraviolet emission from ZnO quantum dots-based/GaN heterojunction diodes by MgO interlayer

NASA Astrophysics Data System (ADS)

Chen, Cheng; Liang, Renli; Chen, Jingwen; Zhang, Jun; Wang, Shuai; Zhao, Chong; Zhang, Wei; Dai, Jiangnan; Chen, Changqing

2017-07-01

We demonstrate the fabrication and characterization of ZnO/GaN-based heterojunction light-emitting diodes (LEDs) by using air-stable and solution-processable ZnO quantum dots (QDs) with a thin MgO interlayer acting as an electron blocking layer (EBL). The ZnO QDs/MgO/ p-GaN heterojunction can only display electroluminescence (EL) characteristic in reverse bias regime. Under sufficient reverse bias, a fairly pure ultraviolet EL emission located at 370 nm deriving from near band edge of ZnO with a full width at half maximum (FWHM) of 8.3 nm had been obtained, while the deep-level emission had been almost totally suppressed. The EL origination and corresponding carrier transport mechanisms were investigated qualitatively in terms of photoluminescence (PL) results and energy band diagram.[Figure not available: see fulltext.

Colloidal polymers with controlled sequence and branching constructed from magnetic field assembled nanoparticles.

PubMed

Bannwarth, Markus B; Utech, Stefanie; Ebert, Sandro; Weitz, David A; Crespy, Daniel; Landfester, Katharina

2015-03-24

The assembly of nanoparticles into polymer-like architectures is challenging and usually requires highly defined colloidal building blocks. Here, we show that the broad size-distribution of a simple dispersion of magnetic nanocolloids can be exploited to obtain various polymer-like architectures. The particles are assembled under an external magnetic field and permanently linked by thermal sintering. The remarkable variety of polymer-analogue architectures that arises from this simple process ranges from statistical and block copolymer-like sequencing to branched chains and networks. This library of architectures can be realized by controlling the sequencing of the particles and the junction points via a size-dependent self-assembly of the single building blocks.

ETR BUILDING, TRA642. SOUTH SIDE VIEW INCLUDES SOUTH SIDES OF ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

ETR BUILDING, TRA-642. SOUTH SIDE VIEW INCLUDES SOUTH SIDES OF ETR BUILDING (HIGH ROOF LINE); ELECTRICAL BUILDING (ONE-STORY, MADE OF PUMICE BLOCKS), TRA-648; AND HEAT EXCHANGER BUILDING (WITH BUILDING NUMBERS), TRA-644. NOTE PROJECTION OF ELECTRICAL BUILDING AT LEFT EDGE OF VIEW. CAMERA FACES NORTH. INL NEGATIVE NO. HD46-37-3. Mike Crane, Photographer, 4/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

Microfibres and macroscopic films from the coordination-driven hierarchical self-assembly of cylindrical micelles

PubMed Central

Lunn, David J.; Gould, Oliver E. C.; Whittell, George R.; Armstrong, Daniel P.; Mineart, Kenneth P.; Winnik, Mitchell A.; Spontak, Richard J.; Pringle, Paul G.; Manners, Ian

2016-01-01

Anisotropic nanoparticles prepared from block copolymers are of growing importance as building blocks for the creation of synthetic hierarchical materials. However, the assembly of these structural units is generally limited to the use of amphiphilic interactions. Here we report a simple, reversible coordination-driven hierarchical self-assembly strategy for the preparation of micron-scale fibres and macroscopic films based on monodisperse cylindrical block copolymer micelles. Coordination of Pd(0) metal centres to phosphine ligands immobilized within the soluble coronas of block copolymer micelles is found to induce intermicelle crosslinking, affording stable linear fibres comprised of micelle subunits in a staggered arrangement. The mean length of the fibres can be varied by altering the micelle concentration, reaction stoichiometry or aspect ratio of the micelle building blocks. Furthermore, the fibres aggregate on drying to form robust, self-supporting macroscopic micelle-based thin films with useful mechanical properties that are analogous to crosslinked polymer networks, but on a longer length scale. PMID:27538877

Electrophoretic deposition of fluorescent Cu and Au sheets for light-emitting diodes

NASA Astrophysics Data System (ADS)

Liu, Jiale; Wu, Zhennan; Li, Tingting; Zhou, Ding; Zhang, Kai; Sheng, Yu; Cui, Jianli; Zhang, Hao; Yang, Bai

2015-12-01

Electrophoretic deposition (EPD) is a conventional method for fabricating film materials from nanometer-sized building blocks, and exhibits the advantages of low-cost, high-efficiency, wide-range thickness adjustment, and uniform deposition. Inspired by the interest in the application of two-dimensional (2D) nanomaterials, the EPD technique has been recently extended to building blocks with 2D features. However, the studies are mainly focused on simplex building blocks. The utilization of multiplex building blocks is rarely reported. In this work, we demonstrate a controlled EPD of Cu and Au sheets, which are 2D assemblies of luminescent Cu and Au nanoclusters. Systematic investigations reveal that both the deposition efficiency and the thickness are determined by the lateral size of the sheets. For Cu sheets with a large lateral size, a high ζ-potential and strong face-to-face van der Waals interactions facilitate the deposition with high efficiency. However, for Au sheets, the small lateral size and ζ-potential limit the formation of a thick film. To solve this problem, the deposition dynamics are controlled by increasing the concentration of the Au sheets and adding acetone. This understanding permits the fabrication of a binary EPD film by the stepwise deposition of Cu and Au sheets, thus producing a luminescent film with both Cu green emission and Au red emission. A white light-emitting diode prototype with color coordinates (x, y) = (0.31, 0.36) is fabricated by employing the EPD film as a color conversion layer on a 365 nm GaN clip and further tuning the amount of deposited Cu and Au sheets.Electrophoretic deposition (EPD) is a conventional method for fabricating film materials from nanometer-sized building blocks, and exhibits the advantages of low-cost, high-efficiency, wide-range thickness adjustment, and uniform deposition. Inspired by the interest in the application of two-dimensional (2D) nanomaterials, the EPD technique has been recently extended to building blocks with 2D features. However, the studies are mainly focused on simplex building blocks. The utilization of multiplex building blocks is rarely reported. In this work, we demonstrate a controlled EPD of Cu and Au sheets, which are 2D assemblies of luminescent Cu and Au nanoclusters. Systematic investigations reveal that both the deposition efficiency and the thickness are determined by the lateral size of the sheets. For Cu sheets with a large lateral size, a high ζ-potential and strong face-to-face van der Waals interactions facilitate the deposition with high efficiency. However, for Au sheets, the small lateral size and ζ-potential limit the formation of a thick film. To solve this problem, the deposition dynamics are controlled by increasing the concentration of the Au sheets and adding acetone. This understanding permits the fabrication of a binary EPD film by the stepwise deposition of Cu and Au sheets, thus producing a luminescent film with both Cu green emission and Au red emission. A white light-emitting diode prototype with color coordinates (x, y) = (0.31, 0.36) is fabricated by employing the EPD film as a color conversion layer on a 365 nm GaN clip and further tuning the amount of deposited Cu and Au sheets. Electronic supplementary information (ESI) available: Additional experimental information, and SEM images of Cu EPD films. See DOI: 10.1039/c5nr06599b

Streambank Protection Guidelines for Landowners and Local Governments,

DTIC Science & Technology

1983-10-01

building blocks , slag , and quarry waste. UNCHE SON / / Large flat slabs should be broken up into /smaller pieces. Garbage, vegetation, scrap lumber...concrete blocks , and house brick. but will not provide any long-term protection. Preabrfirated commercial gabion basket. Completed gabion revetment made...prevent pressure buildup that could cause revetment failure. BLOCKS . Precast cellular blocks can be *,-’e : Typi.tal sa.d- e, .t bag r ’etment

44. RAILROAD TRACKS, WITH BISHOP'S BLOCK, MCFADDEN COFFEE AND SPICE ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

44. RAILROAD TRACKS, WITH BISHOP'S BLOCK, MCFADDEN COFFEE AND SPICE COMPANY FACTORY AND WAREHOUSE AND DUBUQUE SEED COMPANY WAREHOUSE IN BACKGROUND. VIEW TO SOUTHWEST. - Dubuque Commercial & Industrial Buildings, Dubuque, Dubuque County, IA

43. RAILROAD TRACKS, WITH BISHOP'S BLOCK, MCFADDEN COFFEE AND SPICE ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

43. RAILROAD TRACKS, WITH BISHOP'S BLOCK, MCFADDEN COFFEE AND SPICE COMPANY FACTORY AND WAREHOUSE AND DUBUQUE SEED COMPANY WAREHOUSE IN BACKGROUND. VIEW TO SOUTHWEST. - Dubuque Commercial & Industrial Buildings, Dubuque, Dubuque County, IA

42. RAILROAD TRACKS, WITH BISHOP'S BLOCK, MCFADDEN COFFEE AND SPICE ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

42. RAILROAD TRACKS, WITH BISHOP'S BLOCK, MCFADDEN COFFEE AND SPICE COMPANY FACTORY AND WAREHOUSE AND DUBUQUE SEED COMPANY WAREHOUSE IN BACKGROUND. VIEW TO SOUTHWEST. - Dubuque Commercial & Industrial Buildings, Dubuque, Dubuque County, IA

Analysis of Remote Site Energy Storage and Generation Systems

DTIC Science & Technology

1979-07-01

Identify by block numIber) Wind Turbines Solar Energy Energy Wheels Solar Cells Wind Energy Hydrogen Energy Storage The rmion ics Energy Storage...using two separate nominal eight kilowatt wind turbine modules in con- * DD JAN 73 1473 UNCLASSIFIED41 SECURITY CLASSIFICATION OF THIS PAGE (When Dot...2. 1.3 Advanced Wind Energy Converters 28 2. 1. 3. 1 Cyclogyro 28 2. 1.3.2 Diffuser Augmented Wind Turbine (DAWT) 28 2.1.3.3 Vortex Augmenter Wind

Directed Block Copolymer Assembly versus Electron Beam Lithography for Bit-Patterned Media with Areal Density of 1 Terabit/inch(2) and Beyond.

PubMed

Yang, Xiaomin; Wan, Lei; Xiao, Shuaigang; Xu, Yuan; Weller, Dieter K

2009-07-28

The directed self-assembly of block copolymer (BCP) offers a new route to perfect nanolithographic patterning at sub-50 nm length scale with molecular scale precision. We have explored the feasibility of using the BCP approach versus the conventional electron beam (e-beam) lithography to create highly dense dot patterns for bit-patterned media (BPM) applications. Cylinder-forming poly(styrene-b-methyl methacrylate) (PS-b-PMMA) directly self-assembled on a chemically prepatterned substrate. The nearly perfect hexagonal arrays of perpendicularly oriented cylindrical pores at a density of approximately 1 Terabit per square inch (Tb/in.(2)) are achieved over an arbitrarily large area. Considerable gains in the BCP process are observed relative to the conventional e-beam lithography in terms of the dot size variation, the placement accuracy, the pattern uniformity, and the exposure latitude. The maximum dimensional latitude in the cylinder-forming BCP patterns and the maximum skew angle that the BCP can tolerate have been investigated for the first time. The dimensional latitude restricts the formation of more than one lattice configuration in certain ranges. More defects in BCP patterns are observed when using low molecular weight BCP materials or on non-hexagonal prepatterns due to the dimensional latitude restriction. Finally, the limitations and challenges in the BCP approach that are associated with BPM applications will be briefly discussed.

12. SOUTHWEST VIEW OF BUILDING 25C (SUBSONIC AERODYNAMICS TEST FACILITY) ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

12. SOUTHWEST VIEW OF BUILDING 25C (SUBSONIC AERODYNAMICS TEST FACILITY) (1992). - Wright-Patterson Air Force Base, Area B, Buildings 25 & 24,10-foot & 20-foot Wind Tunnel Complex, Northeast side of block bounded by K, G, Third, & Fifth Streets, Dayton, Montgomery County, OH

Photogrammetric Recording and Reconstruction of Town Scale Models - the Case of the Plan-Relief of Strasbourg

NASA Astrophysics Data System (ADS)

Macher, H.; Grussenmeyer, P.; Landes, T.; Halin, G.; Chevrier, C.; Huyghe, O.

2017-08-01

The French collection of Plan-Reliefs, scale models of fortified towns, constitutes a precious testimony of the history of France. The aim of the URBANIA project is the valorisation and the diffusion of this Heritage through the creation of virtual models. The town scale model of Strasbourg at 1/600 currently exhibited in the Historical Museum of Strasbourg was selected as a case study. In this paper, the photogrammetric recording of this scale model is first presented. The acquisition protocol as well as the data post-processing are detailed. Then, the modelling of the city and more specially building blocks is investigated. Based on point clouds of the scale model, the extraction of roof elements is considered. It deals first with the segmentation of the point cloud into building blocks. Then, for each block, points belonging to roofs are identified and the extraction of chimney point clouds as well as roof ridges and roof planes is performed. Finally, the 3D parametric modelling of the building blocks is studied by considering roof polygons and polylines describing chimneys as input. In a future works section, the semantically enrichment and the potential usage scenarios of the scale model are envisaged.

School's Out, Let's Eat: FRAC's Guide to Using the Child and Adult Care Food Program (CACFP) to Expand Afterschool Opportunities for Children. The Building Blocks Project. Promoting Education and Child Development with Nutrition Resources.

ERIC Educational Resources Information Center

Wierwille, Jennifer; Parker, Lynn; Henchy, Geraldine; Driscoll, Christin M.; Tingling-Clemmons, Michele

The provision of quality before- and after-school child care is a major challenge facing educators. This guide from the Food Research and Action Center's Building Blocks Project provides information to providers of before and after school programs on using the federal Child and Adult Care Food Program (CACFP) to provide snacks and meals. Following…

Molecularly Defined Nanostructures Based on a Novel AAA-DDD Triple Hydrogen-Bonding Motif.

PubMed

Papmeyer, Marcus; Vuilleumier, Clément A; Pavan, Giovanni M; Zhurov, Konstantin O; Severin, Kay

2016-01-26

A facile and flexible method for the synthesis of a new AAA-DDD triple hydrogen-bonding motif is described. Polytopic supramolecular building blocks with precisely oriented AAA and DDD groups are thus accessible in few steps. These building blocks were used for the assembly of large macrocycles featuring four AAA-DDD interactions and a macrobicyclic complex with a total of six AAA-DDD interactions. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Enantioselective Copper-Catalyzed Oxy-Alkynylation of Diazo Compounds.

PubMed

Hari, Durga Prasad; Waser, Jerome

2017-06-28

Enantioselective catalytic methods allowing the addition of both a nucleophile and an electrophile onto diazo compounds give a fast access into important building blocks. Herein, we report the highly enantioselective oxyalkynylation of diazo compounds using ethynylbenziodoxol-(on)e reagents and a simple copper bisoxazoline catalyst. The obtained α-benzoyloxy propargylic esters are useful building blocks, which are difficult to synthesize in enantiopure form using other methods. The obtained products could be efficiently transformed into vicinal diols and α-hydroxy propargylic esters without loss in enantiopurity.

Single crystalline Ge(1-x)Mn(x) nanowires as building blocks for nanoelectronics.

PubMed

van der Meulen, Machteld I; Petkov, Nikolay; Morris, Michael A; Kazakova, Olga; Han, Xinhai; Wang, Kang L; Jacob, Ajey P; Holmes, Justin D

2009-01-01

Magnetically doped Si and Ge nanowires have potential application in future nanowire spin-based devices. Here, we report a supercritical fluid method for producing single crystalline Mn-doped Ge nanowires with a Mn-doping concentration of between 0.5-1.0 atomic % that display ferromagnetism above 300 K and a superior performance with respect to the hole mobility of around 340 cm(2)/Vs, demonstrating the potential of using these nanowires as building blocks for electronic devices.

4. Historic American Buildings Survey Nathaniel R. Ewan, Photographer January ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

4. Historic American Buildings Survey Nathaniel R. Ewan, Photographer January 6, 1939 INTERIOR - END CARRIAGE 'BLOCK AND DOGS' - McMurtry's Saw Mill, Hardscrabble Road, Basking Ridge, Somerset County, NJ

Historic American Buildings Survey PHOTOCOPY OF MEASURED DRAWING BY DIETER ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Historic American Buildings Survey PHOTOCOPY OF MEASURED DRAWING BY DIETER SENGLER, 1964 CROSS SECTION AND ORIGINAL JACKSON BOULEVARD ELEVATION - Monadnock Block, 53 West Jackson Boulevard, Chicago, Cook County, IL

Modular Assembly of Hierarchically Structured Polymers

NASA Astrophysics Data System (ADS)

Leophairatana, Porakrit

The synthesis of macromolecules with complex yet highly controlled molecular architectures has attracted significant attention in the past few decades due to the growing demand for specialty polymers that possess novel properties. Despite recent efforts, current synthetic routes lack the ability to control several important architectural variables while maintaining low polydispersity index. This dissertation explores a new synthetic scheme for the modular assembly of hierarchically structured polymers (MAHP) that allows virtually any complex polymer to be assembled from a few basic molecular building blocks using a single common coupling chemistry. Complex polymer structures can be assembled from a molecular toolkit consisting of (1) copper-catalyzed azide-alkyne cycloaddition (CuAAC), (2) linear heterobifunctional macromonomers, (3) a branching heterotrifunctional molecule, (4) a protection/deprotection strategy, (5) "click" functional solid substrates, and (6) functional and responsive polymers. This work addresses the different challenges that emerged during the development of this synthetic scheme, and presents strategies to overcome those challenges. Chapter 3 investigates the alkyne-alkyne (i.e. Glaser) coupling side reactions associated with the atom transfer radical polymerization (ATRP) synthesis of alkyne-functional macromonomers, as well as with the CuAAC reaction of alkyne functional building blocks. In typical ATRP synthesis of unprotected alkyne functional polymers, Glaser coupling reactions can significantly compromise the polymer functionality and undermine the success of subsequent click reactions in which the polymers are used. Two strategies are reported that effectively eliminate these coupling reactions: (1) maintaining low temperature post-ATRP upon exposure to air, followed by immediate removal of copper catalyst; and (2) adding excess reducing agents post-ATRP, which prevents the oxidation of Cu(I) catalyst required by the Glaser coupling mechanism. Post-ATRP Glaser coupling was also influenced by the ATRP synthesis ligand used. The order of ligand activity for catalyzing Glaser coupling was: linear bidentate > tridentate > tetradentate. Glaser coupling can also occur for alkynes held under CuAAC reaction conditions but again can be eliminated by adding appropriate reducing agents. With the strategy presented in Chapter 3, alkyne-terminated polymers of high-functionality were produced without the need for alkyne protecting groups. These "click" functional building blocks were employed to investigate the overall efficiency of the CuAAC "click" coupling reactions between alkyne- and azide-terminated macromonomers as discussed in Chapter 4. Quantitative convolution modeling of the entire molecular weight distribution post-CuAAC indicates a CuAAC efficiency of about 94% and an azide substitution efficiency of >99%. However, incomplete functionality of the azide-terminated macromonomer (˜92%) proves to be the largest factor compromising the overall efficacy of the coupling reactions, and is attributed primarily to the loss of bromine functionality during synthesis by ATRP. To address this issue, we discuss in Chapter 6 the development of a new set of molecular building blocks consisting of alkyne functional substrates and heterobifunctional degradable linkers that allow the growth and subsequent detachment of polymers from the solid substrate. Complex polymeric structures are created by progressive cycles of CuAAC and deprotection reactions that add building blocks to the growing polymer chain ends. We demonstrate that these building blocks were completely stable under both CuAAC and deprotection reaction conditions. Since the desired product is covalently bound to the solid surface, the unreacted monomers/macromonomers and by-products (i.e. non-functional building blocks) can be easily separated from the product via removal of the polymer-tethered solid substrate in one step. Chapter 5 discusses how MAHP was employed to prepare a variety of hierarchically structured polymers and copolymers with controlled branching architectures. alpha-azido,o-TIPS-alkyne-heterobifunctional and heterotrifunctional building blocks were first prepared via ATRP and organic synthesis. Preliminary NMR and SEC studies demonstrated that these building blocks all satisfied the criteria necessary for MAHP: (1) the TIPS protecting group is stable during ATRP and CuAAC, (2) the "click" functionality is completely regenerated during the deprotection step, and (3) the CuAAC reaction of branching macromonomers is quantitative (>94%). To demonstrate the concept, poly(n-butyl acrylate)-b-dipolystyrene- b-dipoly(tert-butyl acrylate) penta-block branching copolymacromer was prepared via MAHP and quantitively characterized with SEC and NMR. (Abstract shortened by ProQuest.).

Development of volume deposition on cast iron by additive manufacturing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sridharan, Niyanth; Dehoff, Ryan R.; Jordan, Brian H.

2016-11-10

ORNL partnered with Cummins to demonstrate the feasibility of using additive manufacturing techniques to help develop repair techniques for refurbished cast iron engine blocks. Cummins is interested in the refurbished engine business due to the increased cost savings and reduced emissions. It is expected that by refurbishing engines could help reduce the green house gas emissions by as much as 85%. Though such repair techniques are possible in principle there has been no major industry in the automotive sector that has deployed this technology. Therefore phase-1 would seek to evaluate the feasibility of using the laser directed energy deposition techniquemore » to repair cast iron engine blocks. The objective of the phase-1 would be to explore various strategies and understand the challenges involved. During phase-1 deposits were made using Inconel-718, Nickel, Nr-Cr-B braze filler. Inconel 718 builds showed significant cracking in the heat-affected zone in the cast iron. Nickel was used to reduce the cracking in the cast iron substrate, however the Ni builds did not wet the substrate sufficiently resulting in poor dimensional tolerance. In order to increase wetting the Ni was alloyed with the Ni-Cr-B braze to decrease the surface tension of Ni. This however resulted in significant cracks in the build due to shrinkage stresses associated with multiple thermal cycling. Hence to reduce the residual stresses in the builds the DMD-103D equipment was modified and the cast iron block was pre heated using cartridge heaters. Inconel-718 alloyed with Ni was deposited on the engine block. The pre-heated deposits showed a reduced susceptibility to cracking. If awarded the phase-2 of the project would aim to develop process parameters to achieve a crack free deposit engine block.« less

Where are lifesaving automated external defibrillators located and how hard is it to find them in a large urban city?

PubMed Central

Leung, Alison C.; Asch, David A.; Lozada, Kirkland N.; Saynisch, Olivia B.; Asch, Jeremy M.; Becker, Nora; Griffis, Heather M.; Shofer, Frances; Hershey, John C.; Hill, Shawndra; Branas, Charles C.; Nichol, Graham; Becker, Lance B.; Merchant, Raina M.

2013-01-01

Objectives Automated external defibrillators (AEDs) are lifesaving, but little is known about where they are located or how to find them. We sought to locate AEDs in high employment areas of Philadelphia and characterize the process of door-to-door surveying to identify these devices. Methods Block groups representing approximately the top 3rd of total primary jobs in Philadelphia were identified using the US Census Local Employment Dynamics database. All buildings within these block groups were surveyed during regular working hours over six weeks during July-August 2011. Buildings were characterized as publically accessible or inaccessible. For accessible buildings, address, location type, and AED presence were collected. Total devices, location description and prior use were gathered in locations with AEDs. Process information (total people contacted, survey duration) was collected for all buildings. Results Of 1420 buildings in 17 block groups, 949 (67%) were accessible, but most 834 (88%) did not have an AED. 283 AEDs were reported in 115 buildings (12%). 81 (29%) were validated through visualization and 68 (24%) through photo because employees often refused access. In buildings with AEDs, several employees (median 2; range 1–8) were contacted to ascertain information, which required several minutes (mean 4; range 1–55). Conclusions Door-to-door surveying is a feasible, but time-consuming method for identifying AEDs in high employment areas. Few buildings reported having AEDs and few permitted visualization, which raises concerns about AED access. To improve cardiac arrest outcomes, efforts are needed to improve the availability of AEDs, awareness of their location and access to them. PMID:23357702

Where are lifesaving automated external defibrillators located and how hard is it to find them in a large urban city?

PubMed

Leung, Alison C; Asch, David A; Lozada, Kirkland N; Saynisch, Olivia B; Asch, Jeremy M; Becker, Nora; Griffis, Heather M; Shofer, Frances; Hershey, John C; Hill, Shawndra; Branas, Charles C; Nichol, Graham; Becker, Lance B; Merchant, Raina M

2013-07-01

Automated external defibrillators (AEDs) are lifesaving, but little is known about where they are located or how to find them. We sought to locate AEDs in high employment areas of Philadelphia and characterize the process of door-to-door surveying to identify these devices. Block groups representing approximately the top 3rd of total primary jobs in Philadelphia were identified using the US Census Local Employment Dynamics database. All buildings within these block groups were surveyed during regular working hours over six weeks during July-August 2011. Buildings were characterized as publically accessible or inaccessible. For accessible buildings, address, location type, and AED presence were collected. Total devices, location description and prior use were gathered in locations with AEDs. Process information (total people contacted, survey duration) was collected for all buildings. Of 1420 buildings in 17 block groups, 949 (67%) were accessible, but most 834 (88%) did not have an AED. 283 AEDs were reported in 115 buildings (12%). 81 (29%) were validated through visualization and 68 (24%) through photo because employees often refused access. In buildings with AEDs, several employees (median 2; range 1-8) were contacted to ascertain information, which required several minutes (mean 4; range 1-55). Door-to-door surveying is a feasible, but time-consuming method for identifying AEDs in high employment areas. Few buildings reported having AEDs and few permitted visualization, which raises concerns about AED access. To improve cardiac arrest outcomes, efforts are needed to improve the availability of AEDs, awareness of their location and access to them. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Properties of Clay for Ceramics with Rock Waste for Production Structural Block by Pressing and Firing

NASA Astrophysics Data System (ADS)

Cerqueira, N. A.; Choe, D.; Alexandre, J.; Azevedo, A. R. G.; Xavier, C. G.; Souza, V. B.

Building work requires optimization of materials and labor, so that the execution of its subsystems contribute to the quality, reduce costs, decrease waste in buildings, productivity, practicality and especially agility. Thus, the fitting blocks can contribute in this direction. This work therefore consists of physical characterization (determination of fitness levels, grain size and bulk density), chemical (EDX) and thermal (DTA and TGA) sample clay Campos dos Goytacazes-RJ and waste rock ornamental Cachoeiro de Itapemirim-ES, to verify potential for producing red ceramic blocks, pressed and burned, male and female type. The output of block will be with different pe rcentages of incorporation of residues of ornamental rocks (0%, 5% and 10%). With the results obtained, it was found that the raw materials under consideration has the potential for application in the production of ceramic articles.

From dots to doughnuts: Two-dimensionally confined deposition of polyelectrolytes on block copolymer templates

DOE PAGES

Oded, Meirav; Kelly, Stephen T.; Gilles, Mary K.; ...

2016-07-05

The combination of block copolymer templating with electrostatic self-assembly provides a simple and robust method for creating nano-patterned polyelectrolyte multilayers over large areas. The deposition of the first polyelectrolyte layer provides important insights on the initial stages of multilayer buildup. Here, we focus on two-dimensionally confined “dots” patterns afforded by block copolymer films featuring hexagonally-packed cylinders that are oriented normal to the substrate. Rendering the cylinder caps positively charged enables the selective deposition of negatively charged polyelectrolytes on them under salt-free conditions. The initially formed polyelectrolyte nanostructures adopt a toroidal (“doughnut”) shape, which results from retraction of dangling polyelectrolyte segmentsmore » into the “dots” upon drying. With increasing exposure time to the polyelectrolyte solution, the final shape of the deposited polyelectrolyte transitions from a doughnut to a hemisphere. In conclusion, these insights would enable the creation of patterned polyelectrolyte multilayers with increased control over adsorption selectivity of the additional incoming polyelectrolytes.« less

From dots to doughnuts: Two-dimensionally confined deposition of polyelectrolytes on block copolymer templates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oded, Meirav; Kelly, Stephen T.; Gilles, Mary K.

The combination of block copolymer templating with electrostatic self-assembly provides a simple and robust method for creating nano-patterned polyelectrolyte multilayers over large areas. The deposition of the first polyelectrolyte layer provides important insights on the initial stages of multilayer buildup. Here, we focus on two-dimensionally confined “dots” patterns afforded by block copolymer films featuring hexagonally-packed cylinders that are oriented normal to the substrate. Rendering the cylinder caps positively charged enables the selective deposition of negatively charged polyelectrolytes on them under salt-free conditions. The initially formed polyelectrolyte nanostructures adopt a toroidal (“doughnut”) shape, which results from retraction of dangling polyelectrolyte segmentsmore » into the “dots” upon drying. With increasing exposure time to the polyelectrolyte solution, the final shape of the deposited polyelectrolyte transitions from a doughnut to a hemisphere. In conclusion, these insights would enable the creation of patterned polyelectrolyte multilayers with increased control over adsorption selectivity of the additional incoming polyelectrolytes.« less

Evaluation of Sunshine Duration around a Building in an Urban Area

NASA Astrophysics Data System (ADS)

Kang, J. E.; Kim, J.

2017-12-01

In this study, sunshine duration around a building in a building-congested district in Busan, Korea was analyzed using a numerical model. This model considers sunshine duration blocking caused by topography and buildings and it is properly applicable to evaluation of sunshine duration environment in urban areas. The 2 km Í 2 km area where the building with 45-m height was located at the center was selected as a target area. We selected the target period from December 21 to December 23, 2015, considering the winter solstice (December 22, 2015) when it is expected to have the largest effect of sunshine blocking due to buildings. We validated the calculated solar altitude and azimuth angles against those provided by Korea astronomy and space science institute (KASI) and the calculated results gave very good agreement with those provided by KASI. Topography and buildings used as the input data of the model were constructed using a geographic information system (GIS) data. In order to analyze, in detail, the change in sunshine duration caused by the construction of the building, the sunshine duration on the roof and walls (eastern, western, southern, northern side) were investigated before and after the construction.

Synthetic fermentation of bioactive non-ribosomal peptides without organisms, enzymes or reagents

NASA Astrophysics Data System (ADS)

Huang, Yi-Lin; Bode, Jeffrey W.

2014-10-01

Microbial fermentation can rapidly provide potent compounds that can be easily screened for biological activity, and the active components can be isolated. Its success in drug discovery has inspired extensive efforts to modulate and control the products. In this Article, we document a ‘synthetic fermentation’ of bioactive, unnatural peptides ‘grown’ from small building blocks in water using amide-forming ligations. No organisms, enzymes or reagents are needed. The sequences, structures and compositions of the products can be modulated by adjusting the building blocks and conditions. No specialized knowledge of organic chemistry or handling of toxic material is required to produce complex organic molecules. The ‘fermentations’ can be conducted in arrays and screened for biological activity without isolation or workup. As a proof-of-concept, about 6,000 unnatural peptides were produced from just 23 building blocks, from which a hepatitis C virus NS3/4A protease inhibitor with a half-maximum inhibitory concentration of 1.0 μM was identified and characterized.

A triaxial supramolecular weave

NASA Astrophysics Data System (ADS)

Lewandowska, Urszula; Zajaczkowski, Wojciech; Corra, Stefano; Tanabe, Junki; Borrmann, Ruediger; Benetti, Edmondo M.; Stappert, Sebastian; Watanabe, Kohei; Ochs, Nellie A. K.; Schaeublin, Robin; Li, Chen; Yashima, Eiji; Pisula, Wojciech; Müllen, Klaus; Wennemers, Helma

2017-11-01

Despite recent advances in the synthesis of increasingly complex topologies at the molecular level, nano- and microscopic weaves have remained difficult to achieve. Only a few diaxial molecular weaves exist—these were achieved by templation with metals. Here, we present an extended triaxial supramolecular weave that consists of self-assembled organic threads. Each thread is formed by the self-assembly of a building block comprising a rigid oligoproline segment with two perylene-monoimide chromophores spaced at 18 Å. Upon π stacking of the chromophores, threads form that feature alternating up- and down-facing voids at regular distances. These voids accommodate incoming building blocks and establish crossing points through CH-π interactions on further assembly of the threads into a triaxial woven superstructure. The resulting micrometre-scale supramolecular weave proved to be more robust than non-woven self-assemblies of the same building block. The uniform hexagonal pores of the interwoven network were able to host iridium nanoparticles, which may be of interest for practical applications.

Morphology-Controlled Synthesis and Metalation of Porphyrin Nanoparticles with Enhanced Photocatalytic Performance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Jiefei; Zhong, Yong; Wang, Liang

The design and engineering of the size, shape, and chemistry of photoactive building blocks enables the fabrication of functional nanoparticles for applications in light harvesting, photocatalytic synthesis, water splitting, phototherapy, and photodegradation. Here, we report the synthesis of such nanoparticles through a surfactant-assisted interfacial self-assembly process using optically active porphyrin as a functional building block. The self-assembly process relies on specific interactions such as π–π stacking and metalation (metal atoms and ligand coordination) between individual porphyrin building blocks. Depending on the kinetic conditions and type of surfactants, resulting structures exhibit well-defined one- to three-dimensional morphologies such as nanowires, nanooctahedra, andmore » hierarchically ordered internal architectures. Specifically, electron microscopy and X-ray diffraction results indicate that these nanoparticles exhibit stable single-crystalline and nanoporous frameworks. In conclusion, due to the hierarchical ordering of the porphyrins, the nanoparticles exhibit collective optical properties resulted from coupling of molecular porphyrins and photocatalytic activities such as photodegradation of methyl orange (MO) pollutants and hydrogen production.« less

Plasmid Vectors and Molecular Building Blocks for the Development of Genetic Manipulation Tools for Trypanosoma cruzi

PubMed Central

Bouvier, León A.; Cámara, María de los Milagros; Canepa, Gaspar E.; Miranda, Mariana R.; Pereira, Claudio A.

2013-01-01

The post genomic era revealed the need for developing better performing, easier to use and more sophisticated genetic manipulation tools for the study of Trypanosoma cruzi, the etiological agent of Chagas disease. In this work a series of plasmids that allow genetic manipulation of this protozoan parasite were developed. First of all we focused on useful tools to establish selection strategies for different strains and which can be employed as expression vectors. On the other hand molecular building blocks in the form of diverse selectable markers, modifiable fluorescent protein and epitope-tag coding sequences were produced. Both types of modules were harboured in backbone molecules conceived to offer multiple construction and sub-cloning strategies. These can be used to confer new properties to already available genetic manipulation tools or as starting points for whole novel designs. The performance of each plasmid and building block was determined independently. For illustration purposes, some simple direct practical applications were conducted. PMID:24205392

Robust excitons inhabit soft supramolecular nanotubes

PubMed Central

Eisele, Dörthe M.; Arias, Dylan H.; Fu, Xiaofeng; Bloemsma, Erik A.; Steiner, Colby P.; Jensen, Russell A.; Rebentrost, Patrick; Eisele, Holger; Tokmakoff, Andrei; Lloyd, Seth; Nelson, Keith A.; Nicastro, Daniela; Knoester, Jasper; Bawendi, Moungi G.

2014-01-01

Nature's highly efficient light-harvesting antennae, such as those found in green sulfur bacteria, consist of supramolecular building blocks that self-assemble into a hierarchy of close-packed structures. In an effort to mimic the fundamental processes that govern nature’s efficient systems, it is important to elucidate the role of each level of hierarchy: from molecule, to supramolecular building block, to close-packed building blocks. Here, we study the impact of hierarchical structure. We present a model system that mirrors nature’s complexity: cylinders self-assembled from cyanine-dye molecules. Our work reveals that even though close-packing may alter the cylinders’ soft mesoscopic structure, robust delocalized excitons are retained: Internal order and strong excitation-transfer interactions—prerequisites for efficient energy transport—are both maintained. Our results suggest that the cylindrical geometry strongly favors robust excitons; it presents a rational design that is potentially key to nature’s high efficiency, allowing construction of efficient light-harvesting devices even from soft, supramolecular materials. PMID:25092336

Biomimetic, Strong, Tough, and Self-Healing Composites Using Universal Sealant-Loaded, Porous Building Blocks.

PubMed

Hwang, Sung Hoon; Miller, Joseph B; Shahsavari, Rouzbeh

2017-10-25

Many natural materials, such as nacre and dentin, exhibit multifunctional mechanical properties via structural interplay between compliant and stiff constituents arranged in a particular architecture. Herein, we present, for the first time, the bottom-up synthesis and design of strong, tough, and self-healing composite using simple but universal spherical building blocks. Our composite system is composed of calcium silicate porous nanoparticles with unprecedented monodispersity over particle size, particle shape, and pore size, which facilitate effective loading and unloading with organic sealants, resulting in 258% and 307% increases in the indentation hardness and elastic modulus of the compacted composite. Furthermore, heating the damaged composite triggers the controlled release of the nanoconfined sealant into the surrounding area, enabling moderate recovery in strength and toughness. This work paves the path towards fabricating a novel class of biomimetic composites using low-cost spherical building blocks, potentially impacting bone-tissue engineering, insulation, refractory and constructions materials, and ceramic matrix composites.

Morphology-Controlled Synthesis and Metalation of Porphyrin Nanoparticles with Enhanced Photocatalytic Performance

DOE PAGES

Wang, Jiefei; Zhong, Yong; Wang, Liang; ...

2016-09-12

The design and engineering of the size, shape, and chemistry of photoactive building blocks enables the fabrication of functional nanoparticles for applications in light harvesting, photocatalytic synthesis, water splitting, phototherapy, and photodegradation. Here, we report the synthesis of such nanoparticles through a surfactant-assisted interfacial self-assembly process using optically active porphyrin as a functional building block. The self-assembly process relies on specific interactions such as π–π stacking and metalation (metal atoms and ligand coordination) between individual porphyrin building blocks. Depending on the kinetic conditions and type of surfactants, resulting structures exhibit well-defined one- to three-dimensional morphologies such as nanowires, nanooctahedra, andmore » hierarchically ordered internal architectures. Specifically, electron microscopy and X-ray diffraction results indicate that these nanoparticles exhibit stable single-crystalline and nanoporous frameworks. In conclusion, due to the hierarchical ordering of the porphyrins, the nanoparticles exhibit collective optical properties resulted from coupling of molecular porphyrins and photocatalytic activities such as photodegradation of methyl orange (MO) pollutants and hydrogen production.« less

Templated Assembly of a Functional Ordered Protein Macromolecular Framework from P22 Virus-like Particles.

PubMed

McCoy, Kimberly; Uchida, Masaki; Lee, Byeongdu; Douglas, Trevor

2018-04-24

Bottom-up construction of mesoscale materials using biologically derived nanoscale building blocks enables engineering of desired physical properties using green production methods. Virus-like particles (VLPs) are exceptional building blocks due to their monodispersed sizes, geometric shapes, production ease, proteinaceous composition, and our ability to independently functionalize the interior and exterior interfaces. Here a VLP, derived from bacteriophage P22, is used as a building block for the fabrication of a protein macromolecular framework (PMF), a tightly linked 3D network of functional protein cages that exhibit long-range order and catalytic activity. Assembly of PMFs was electrostatically templated, using amine-terminated dendrimers, then locked into place with a ditopic cementing protein that binds to P22. Long-range order is preserved on removal of the dendrimer, leaving a framework material composed completely of protein. Encapsulation of β-glucosidase enzymes inside of P22 VLPs results in formation of stable, condensed-phase materials with high local concentration of enzymes generating catalytically active PMFs.

Designed synthesis of double-stage two-dimensional covalent organic frameworks

PubMed Central

Chen, Xiong; Addicoat, Matthew; Jin, Enquan; Xu, Hong; Hayashi, Taku; Xu, Fei; Huang, Ning; Irle, Stephan; Jiang, Donglin

2015-01-01

Covalent organic frameworks (COFs) are an emerging class of crystalline porous polymers in which organic building blocks are covalently and topologically linked to form extended crystalline polygon structures, constituting a new platform for designing π-electronic porous materials. However, COFs are currently synthesised by a few chemical reactions, limiting the access to and exploration of new structures and properties. The development of new reaction systems that avoid such limitations to expand structural diversity is highly desired. Here we report that COFs can be synthesised via a double-stage connection that polymerises various different building blocks into crystalline polygon architectures, leading to the development of a new type of COFs with enhanced structural complexity and diversity. We show that the double-stage approach not only controls the sequence of building blocks but also allows fine engineering of pore size and shape. This strategy is widely applicable to different polymerisation systems to yield hexagonal, tetragonal and rhombus COFs with predesigned pores and π-arrays. PMID:26456081

Engineering cell factories for producing building block chemicals for bio-polymer synthesis.

PubMed

Tsuge, Yota; Kawaguchi, Hideo; Sasaki, Kengo; Kondo, Akihiko

2016-01-21

Synthetic polymers are widely used in daily life. Due to increasing environmental concerns related to global warming and the depletion of oil reserves, the development of microbial-based fermentation processes for the production of polymer building block chemicals from renewable resources is desirable to replace current petroleum-based methods. To this end, strains that efficiently produce the target chemicals at high yields and productivity are needed. Recent advances in metabolic engineering have enabled the biosynthesis of polymer compounds at high yield and productivities by governing the carbon flux towards the target chemicals. Using these methods, microbial strains have been engineered to produce monomer chemicals for replacing traditional petroleum-derived aliphatic polymers. These developments also raise the possibility of microbial production of aromatic chemicals for synthesizing high-performance polymers with desirable properties, such as ultraviolet absorbance, high thermal resistance, and mechanical strength. In the present review, we summarize recent progress in metabolic engineering approaches to optimize microbial strains for producing building blocks to synthesize aliphatic and high-performance aromatic polymers.

Recurrence of 49-base decamers, nonomers, and octamers within mouse C mu gene of Ig heavy chain and its primordial building block.

PubMed Central

Yazaki, A; Ohno, S

1983-01-01

Within the published 2,168-base-long mouse C mu gene of Ig heavy chain consisting of four coding and four noncoding segments, 2 base decamers, 8 nonomers, and 39 octamers recurred. Recurring base heptamers (about 100) and hexamers (about 350) were simply too numerous to merit individual identification. In spite of extensive overlaps between these recurring base decamers to hexamers, they occupied nearly the entire length of mouse Ig C mu gene. As with other genes of the beta-sheet-forming beta 2-microglobulin family, the Ig C mu gene (flanking and intervening noncoding sequences included) is not a unique sequence but rather it is degenerate repeats of the 45-base-long primordial building-block sequence uniquely its own. This primordial building block must originally have specified the 15-amino-acid-residue-long primordial arm of beta-sheet-forming loops, the characteristics of the beta 2-microglobulin family of polypeptides. PMID:6403948

Exploring the building blocks of social cognition: spontaneous agency perception and visual perspective taking in autism.

PubMed

Zwickel, Jan; White, Sarah J; Coniston, Devorah; Senju, Atsushi; Frith, Uta

2011-10-01

Individuals with autism spectrum disorders have highly characteristic impairments in social interaction and this is true also for those with high functioning autism or Asperger syndrome (AS). These social cognitive impairments are far from global and it seems likely that some of the building blocks of social cognition are intact. In our first experiment, we investigated whether high functioning adults who also had a diagnosis of AS would be similar to control participants in terms of their eye movements when watching animated triangles in short movies that normally evoke mentalizing. They were. Our second experiment using the same movies, tested whether both groups would spontaneously adopt the visuo-spatial perspective of a triangle protagonist. They did. At the same time autistic participants differed in their verbal accounts of the story line underlying the movies, confirming their specific difficulties in on-line mentalizing. In spite of this difficulty, two basic building blocks of social cognition appear to be intact: spontaneous agency perception and spontaneous visual perspective taking.

Fuel-Mediated Transient Clustering of Colloidal Building Blocks.

PubMed

van Ravensteijn, Bas G P; Hendriksen, Wouter E; Eelkema, Rienk; van Esch, Jan H; Kegel, Willem K

2017-07-26

Fuel-driven assembly operates under the continuous influx of energy and results in superstructures that exist out of equilibrium. Such dissipative processes provide a route toward structures and transient behavior unreachable by conventional equilibrium self-assembly. Although perfected in biological systems like microtubules, this class of assembly is only sparsely used in synthetic or colloidal analogues. Here, we present a novel colloidal system that shows transient clustering driven by a chemical fuel. Addition of fuel causes an increase in hydrophobicity of the building blocks by actively removing surface charges, thereby driving their aggregation. Depletion of fuel causes reappearance of the charged moieties and leads to disassembly of the formed clusters. This reassures that the system returns to its initial, equilibrium state. By taking advantage of the cyclic nature of our system, we show that clustering can be induced several times by simple injection of new fuel. The fuel-mediated assembly of colloidal building blocks presented here opens new avenues to the complex landscape of nonequilibrium colloidal structures, guided by biological design principles.

Appendices for the Space Applications program, 1974

NASA Technical Reports Server (NTRS)

1974-01-01

To achieve truly low cost system design with direct evolution for inorbit shuttle resupply, a modular building block approach has been adopted. The heart of the modular building block concept lies in the ability to use a common set of nonoptimized subsystems in such a way that a wide variety of missions can be flown with no detrimental impact on performance. By standardizing the mechanical configurations and electrical interfaces of the subsystem modules, and by designing each of them to be structurally and thermally independent entities, it is possible to cluster these building blocks or modules about an instrument system so as to adequately perform the mission without the need for subsystem redevelopments for each mission. This system concept offers the following capabilities: (1) the ability to launch and orbit the observatory by either the Delta, the Titan, or the space shuttle. (2) the ability to completely reconfigure the spacecraft subsystems for different launch vehicles, and (3) the ability to perform in-orbit resupply and/or emergency retrieval of the observatory.

Elasticity-dependent fast underwater adhesion demonstrated by macroscopic supramolecular assembly.

PubMed

Ju, Guannan; Cheng, Mengjiao; Guo, Fengli; Zhang, Qian; Shi, Feng

2018-05-30

Macroscopic supramolecular assembly (MSA) is a recent progress in supramolecular chemistry to associate visible building blocks through non-covalent interactions in a multivalent manner. Although various substrates (e. g. hydrogels, rigid materials) have been used, a general design rule of building blocks in MSA systems and interpretation of the assembly mechanism are still lacking and urgently in demand. Here we design three model systems with varied modulus and correlated the MSA probability with the elasticity. Based on the effects of substrate deformability on multivalency, we have proposed an elastic-modulus-dependent rule that building blocks below a critical modulus of 2.5 MPa can achieve MSA for the used host/guest system. Moreover, this MSA rule applies well to the design of materials applicable for fast underwater adhesion: Soft substrates (0.5 MPa) can achieve underwater adhesion within 10 s with one magnitude higher strength than that of rigid substrates (2.5 MPa). © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

High-flexibility combinatorial peptide synthesis with laser-based transfer of monomers in solid matrix material.

PubMed

Loeffler, Felix F; Foertsch, Tobias C; Popov, Roman; Mattes, Daniela S; Schlageter, Martin; Sedlmayr, Martyna; Ridder, Barbara; Dang, Florian-Xuan; von Bojničić-Kninski, Clemens; Weber, Laura K; Fischer, Andrea; Greifenstein, Juliane; Bykovskaya, Valentina; Buliev, Ivan; Bischoff, F Ralf; Hahn, Lothar; Meier, Michael A R; Bräse, Stefan; Powell, Annie K; Balaban, Teodor Silviu; Breitling, Frank; Nesterov-Mueller, Alexander

2016-06-14

Laser writing is used to structure surfaces in many different ways in materials and life sciences. However, combinatorial patterning applications are still limited. Here we present a method for cost-efficient combinatorial synthesis of very-high-density peptide arrays with natural and synthetic monomers. A laser automatically transfers nanometre-thin solid material spots from different donor slides to an acceptor. Each donor bears a thin polymer film, embedding one type of monomer. Coupling occurs in a separate heating step, where the matrix becomes viscous and building blocks diffuse and couple to the acceptor surface. Furthermore, we can consecutively deposit two material layers of activation reagents and amino acids. Subsequent heat-induced mixing facilitates an in situ activation and coupling of the monomers. This allows us to incorporate building blocks with click chemistry compatibility or a large variety of commercially available non-activated, for example, posttranslationally modified building blocks into the array's peptides with >17,000 spots per cm(2).

Designed synthesis of double-stage two-dimensional covalent organic frameworks

NASA Astrophysics Data System (ADS)

Chen, Xiong; Addicoat, Matthew; Jin, Enquan; Xu, Hong; Hayashi, Taku; Xu, Fei; Huang, Ning; Irle, Stephan; Jiang, Donglin

2015-10-01

Covalent organic frameworks (COFs) are an emerging class of crystalline porous polymers in which organic building blocks are covalently and topologically linked to form extended crystalline polygon structures, constituting a new platform for designing π-electronic porous materials. However, COFs are currently synthesised by a few chemical reactions, limiting the access to and exploration of new structures and properties. The development of new reaction systems that avoid such limitations to expand structural diversity is highly desired. Here we report that COFs can be synthesised via a double-stage connection that polymerises various different building blocks into crystalline polygon architectures, leading to the development of a new type of COFs with enhanced structural complexity and diversity. We show that the double-stage approach not only controls the sequence of building blocks but also allows fine engineering of pore size and shape. This strategy is widely applicable to different polymerisation systems to yield hexagonal, tetragonal and rhombus COFs with predesigned pores and π-arrays.

The Freeman School: Building Prairie Communities. Teaching with Historic Places.

ERIC Educational Resources Information Center

Lange-Daggs, Lorna

The Freeman School, originally called the Red-Brick School House, served the community of Blakely Township, Nebraska from 1872 to 1967. It is representative of the one-room schools that once dotted the western landscape of the United States. The Freeman School served not only as an educational center but also as the church, a meeting hall, the…

Arts Integration: A Strategy to Improve Teaching and Learning, Promote Personal Competencies, and Turn Around Low-Performing Schools

ERIC Educational Resources Information Center

Biscoe, Belinda; Wilson, Kirk

2015-01-01

This paper connects the dots between arts integration, students' personal competencies, and school turnaround. Its thesis is that by intertwining art forms and methods with content in all subject areas, students learn more about art and the other subjects and build their personal competencies for learning. The paper includes the story of an…

Correlating the magic numbers of inorganic nanomolecular assemblies with a {Pd84} molecular-ring Rosetta Stone

PubMed Central

Xu, Feng; Miras, Haralampos N.; Scullion, Rachel A.; Long, De-Liang; Thiel, Johannes; Cronin, Leroy

2012-01-01

Molecular self-assembly has often been suggested as the ultimate route for the bottom-up construction of building blocks atom-by-atom for functional nanotechnology, yet structural design or prediction of nanomolecular assemblies is still far from reach. Whereas nature uses complex machinery such as the ribosome, chemists use painstakingly engineered step-by-step approaches to build complex molecules but the size and complexity of such molecules, not to mention the accessible yields, can be limited. Herein we present the discovery of a palladium oxometalate {Pd84}-ring cluster 3.3 nm in diameter; [Pd84O42(OAc)28(PO4)42]70- ({Pd84} ≡ {Pd12}7) that is formed in water just by mixing two reagents at room temperature, giving crystals of the compound in just a few days. The structure of the {Pd84}-ring has sevenfold symmetry, comprises 196 building blocks, and we also show, using mass spectrometry, that a large library of other related nanostructures is present in solution. Finally, by analysis of the symmetry and the building block library that construct the {Pd84} we show that the correlation of the symmetry, subunit number, and overall cluster nuclearity can be used as a “Rosetta Stone” to rationalize the “magic numbers” defining a number of other systems. This is because the discovery of {Pd84} allows the relationship between seemingly unrelated families of molecular inorganic nanosystems to be decoded from the overall cluster magic-number nuclearity, to the symmetry and building blocks that define such structures allowing the prediction of other members of these nanocluster families. PMID:22753516

Hydrophilic interaction chromatography-multiple reaction monitoring mass spectrometry method for basic building block analysis of low molecular weight heparins prepared through nitrous acid depolymerization.

PubMed

Sun, Xiaojun; Guo, Zhimou; Yu, Mengqi; Lin, Chao; Sheng, Anran; Wang, Zhiyu; Linhardt, Robert J; Chi, Lianli

2017-01-06

Low molecular weight heparins (LMWHs) are important anticoagulant drugs that are prepared through depolymerization of unfractionated heparin. Based on the types of processing reactions and the structures of the products, LMWHs can be divided into different classifications. Enoxaparin is prepared by benzyl esterification and alkaline depolymerization, while dalteparin and nadroparin are prepared through nitrous acid depolymerization followed by borohydride reduction. Compositional analysis of their basic building blocks is an effective way to provide structural information on heparin and LMWHs. However, most current compositional analysis methods have been limited to heparin and enoxaparin. A sensitive and comprehensive approach is needed for detailed investigation of the structure of LMWHs prepared through nitrous acid depolymerization, especially their characteristic saturated non-reducing end (NRE) and 2,5-anhydro-d-mannitol reducing end (RE). A maltose modified hydrophilic interaction column offers improved separation of complicated mixtures of acidic disaccharides and oligosaccharides. A total of 36 basic building blocks were unambiguously identified by high-resolution tandem mass spectrometry (MS). Multiple reaction monitoring (MRM) MS/MS quantification was developed and validated in the analysis of dalteparin and nadroparin samples. Each group of building blocks revealed different aspects of the properties of LMWHs, such as functional motifs required for anticoagulant activity, the structure of heparin starting materials, cleavage sites in the depolymerization reaction, and undesired structural modifications resulting from side reactions. Copyright © 2016 Elsevier B.V. All rights reserved.

Modular and Orthogonal Synthesis of Hybrid Polymers and Networks

PubMed Central

Liu, Shuang; Dicker, Kevin T.; Jia, Xinqiao

2015-01-01

Biomaterials scientists strive to develop polymeric materials with distinct chemical make-up, complex molecular architectures, robust mechanical properties and defined biological functions by drawing inspirations from biological systems. Salient features of biological designs include (1) repetitive presentation of basic motifs; and (2) efficient integration of diverse building blocks. Thus, an appealing approach to biomaterials synthesis is to combine synthetic and natural building blocks in a modular fashion employing novel chemical methods. Over the past decade, orthogonal chemistries have become powerful enabling tools for the modular synthesis of advanced biomaterials. These reactions require building blocks with complementary functionalities, occur under mild conditions in the presence of biological molecules and living cells and proceed with high yield and exceptional selectivity. These chemistries have facilitated the construction of complex polymers and networks in a step-growth fashion, allowing facile modulation of materials properties by simple variations of the building blocks. In this review, we first summarize features of several types of orthogonal chemistries. We then discuss recent progress in the synthesis of step growth linear polymers, dendrimers and networks that find application in drug delivery, 3D cell culture and tissue engineering. Overall, orthogonal reactions and modulular synthesis have not only minimized the steps needed for the desired chemical transformations but also maximized the diversity and functionality of the final products. The modular nature of the design, combined with the potential synergistic effect of the hybrid system, will likely result in novel hydrogel matrices with robust structures and defined functions. PMID:25572255

Layer-by-layer assembly of two-dimensional materials into wafer-scale heterostructures

NASA Astrophysics Data System (ADS)

Kang, Kibum; Lee, Kan-Heng; Han, Yimo; Gao, Hui; Xie, Saien; Muller, David A.; Park, Jiwoong

2017-10-01

High-performance semiconductor films with vertical compositions that are designed to atomic-scale precision provide the foundation for modern integrated circuitry and novel materials discovery. One approach to realizing such films is sequential layer-by-layer assembly, whereby atomically thin two-dimensional building blocks are vertically stacked, and held together by van der Waals interactions. With this approach, graphene and transition-metal dichalcogenides--which represent one- and three-atom-thick two-dimensional building blocks, respectively--have been used to realize previously inaccessible heterostructures with interesting physical properties. However, no large-scale assembly method exists at present that maintains the intrinsic properties of these two-dimensional building blocks while producing pristine interlayer interfaces, thus limiting the layer-by-layer assembly method to small-scale proof-of-concept demonstrations. Here we report the generation of wafer-scale semiconductor films with a very high level of spatial uniformity and pristine interfaces. The vertical composition and properties of these films are designed at the atomic scale using layer-by-layer assembly of two-dimensional building blocks under vacuum. We fabricate several large-scale, high-quality heterostructure films and devices, including superlattice films with vertical compositions designed layer-by-layer, batch-fabricated tunnel device arrays with resistances that can be tuned over four orders of magnitude, band-engineered heterostructure tunnel diodes, and millimetre-scale ultrathin membranes and windows. The stacked films are detachable, suspendable and compatible with water or plastic surfaces, which will enable their integration with advanced optical and mechanical systems.

Layer-by-layer assembly of two-dimensional materials into wafer-scale heterostructures.

PubMed

Kang, Kibum; Lee, Kan-Heng; Han, Yimo; Gao, Hui; Xie, Saien; Muller, David A; Park, Jiwoong

2017-10-12

High-performance semiconductor films with vertical compositions that are designed to atomic-scale precision provide the foundation for modern integrated circuitry and novel materials discovery. One approach to realizing such films is sequential layer-by-layer assembly, whereby atomically thin two-dimensional building blocks are vertically stacked, and held together by van der Waals interactions. With this approach, graphene and transition-metal dichalcogenides-which represent one- and three-atom-thick two-dimensional building blocks, respectively-have been used to realize previously inaccessible heterostructures with interesting physical properties. However, no large-scale assembly method exists at present that maintains the intrinsic properties of these two-dimensional building blocks while producing pristine interlayer interfaces, thus limiting the layer-by-layer assembly method to small-scale proof-of-concept demonstrations. Here we report the generation of wafer-scale semiconductor films with a very high level of spatial uniformity and pristine interfaces. The vertical composition and properties of these films are designed at the atomic scale using layer-by-layer assembly of two-dimensional building blocks under vacuum. We fabricate several large-scale, high-quality heterostructure films and devices, including superlattice films with vertical compositions designed layer-by-layer, batch-fabricated tunnel device arrays with resistances that can be tuned over four orders of magnitude, band-engineered heterostructure tunnel diodes, and millimetre-scale ultrathin membranes and windows. The stacked films are detachable, suspendable and compatible with water or plastic surfaces, which will enable their integration with advanced optical and mechanical systems.

To Know, or Not to Know - Why it is Important to Understand Both What we Know, and What We Don't Know, When Studying Our Air and Sky

NASA Astrophysics Data System (ADS)

Brown-Steiner, B.

2017-12-01

I study the air and the sky, which can get really, really confusing. When you cup your hands and catch some air, you are holding many hundreds of hundreds of hundreds (do this about ten more times) of really tiny building blocks that keep hitting (and changing) one another every second of every day. We need some of these tiny building blocks to live and breathe, but there are many tiny building blocks that can hurt us - or even kill us. Right now, the way we live - how we make power, how we make food, how we get from place to place - adds a lot of bad building blocks to our air and our sky, and is changing our world in ways we do not really understand. As we learn more about the air and the sky, we get better at knowing how things are changing, but it is also really important to think about the things we do not know, and the things we do not understand. I study our air and our sky by thinking hard not only about the things that we know, but also about the things we do not know, and I try to use what I learn to help us make more sense out of the really confusing stuff. I want to share some of what I have learned with you.

Mononuclear, trinuclear, and hetero-trinuclear supramolecular complexes containing a new tri-sulfonate ligand and cobalt(II)/copper(II)-(1,10-phenanthroline) 2 building blocks

NASA Astrophysics Data System (ADS)

Yu, Yunfang; Wei, Yongqin; Broer, Ria; Sa, Rongjian; Wu, Kechen

2008-03-01

Novel mononuclear, trinuclear, and hetero-trinuclear supermolecular complexes, [Co(phen) 2(H 2O)(HTST)]·2H 2O ( 1), [Co 3(phen) 6(H 2O) 2(TST) 2]·7H 2O ( 2), and [Co 2Cu(phen) 6(H 2O) 2(TST) 2]·10H 2O ( 3), have been synthesized by the reactions of a new tri-sulfonate ligand (2,4,6-tris(4-sulfophenylamino)-1,3,5-triazine, H 3TST) with the M2+ ( M=Co, Cu) and the second ligand 1,10-phenanthroline (phen). Complex 1 contains a cis-Co(II)(phen) 2 building block and an HTST as monodentate ligand; complex 2 consists of two TST as bidentate ligands connecting one trans- and two cis-Co(II)(phen) 2 building blocks; complex 3 is formed by replacing the trans-Co(II)(phen) 2 in 2 with a trans-Cu(II)(phen) 2, which is the first reported hetero-trinuclear supramolecular complex containing both the Co(II)(phen) 2 and Cu(II)(phen) 2 as building blocks. The study shows the flexible multifunctional self-assembly capability of the H 3TST ligands presenting in these supramolecular complexes through coordinative, H-bonding and even π- π stacking interactions. The photoluminescent optical properties of these complexes are also investigated and discussed as well as the second-order nonlinear optical properties of 1.

The Building Blocks for JWST I and T (Integrations and Test) to Operations - From Simulator to Flight Units

NASA Technical Reports Server (NTRS)

Fatig, Curtis; Ochs, William; Johns, Alan; Seaton, Bonita; Adams, Cynthia; Wasiak, Francis; Jones, Ronald; Jackson, Wallace

2012-01-01

The James Webb Space Telescope (JWST) Project has an extended integration and test (I&T) phase due to long procurement and development times of various components as well as recent launch delays. The JWST Ground Segment and Operations group has developed a roadmap of the various ground and flight elements and their use in the various JWST I&T test programs. The JWST Project s building block approach to the eventual operational systems, while not new, is complex and challenging; a large-scale mission like JWST involves international partners, many vendors across the United States, and competing needs for the same systems. One of the challenges is resource balancing so simulators and flight products for various elements congeal into integrated systems used for I&T and flight operations activities. This building block approach to an incremental buildup provides for early problem identification with simulators and exercises the flight operations systems, products, and interfaces during the JWST I&T test programs. The JWST Project has completed some early I&T with the simulators, engineering models and some components of the operational ground system. The JWST Project is testing the various flight units as they are delivered and will continue to do so for the entire flight and operational system. The JWST Project has already and will continue to reap the value of the building block approach on the road to launch and flight operations.

Renaissance architecture for Ground Data Systems

NASA Technical Reports Server (NTRS)

Perkins, Dorothy C.; Zeigenfuss, Lawrence B.

1994-01-01

The Mission Operations and Data Systems Directorate (MO&DSD) has embarked on a new approach for developing and operating Ground Data Systems (GDS) for flight mission support. This approach is driven by the goals of minimizing cost and maximizing customer satisfaction. Achievement of these goals is realized through the use of a standard set of capabilities which can be modified to meet specific user needs. This approach, which is called the Renaissance architecture, stresses the engineering of integrated systems, based upon workstation/local area network (LAN)/fileserver technology and reusable hardware and software components called 'building blocks.' These building blocks are integrated with mission specific capabilities to build the GDS for each individual mission. The building block approach is key to the reduction of development costs and schedules. Also, the Renaissance approach allows the integration of GDS functions that were previously provided via separate multi-mission facilities. With the Renaissance architecture, the GDS can be developed by the MO&DSD or all, or part, of the GDS can be operated by the user at their facility. Flexibility in operation configuration allows both selection of a cost-effective operations approach and the capability for customizing operations to user needs. Thus the focus of the MO&DSD is shifted from operating systems that we have built to building systems and, optionally, operations as separate services. Renaissance is actually a continuous process. Both the building blocks and the system architecture will evolve as user needs and technology change. Providing GDS on a per user basis enables this continuous refinement of the development process and product and allows the MO&DSD to remain a customer-focused organization. This paper will present the activities and results of the MO&DSD initial efforts toward the establishment of the Renaissance approach for the development of GDS, with a particular focus on both the technical and process implications posed by Renaissance to the MO&DSD.