Narrow Grid Research Articles

Regulable crack patterns for the fabrication of high-performance transparent EMI shielding windows.

Crack pattern-based metal grid film is an ideal candidate material for transparent electromagnetic interference shielding optical windows. However, achieving crack patterns with narrow grid spacing, small wire width, and high connectivity remains challenging. Herein, an aqueous acrylic colloidal dispersion was developed as a crack precursor for preparing crack patterns. The ratio of hard monomers in the precursor, the coating thickness, and the drying mediation strategy were systematically varied to control the spacing and width of the crack patterns. The resulting dense and narrow crack patterns served as sacrificial templates for the fabrication of patterning metal grid films on transparent substrates, intended for optoelectronic applications. These films demonstrated excellent optoelectronic properties (82.7% transmission at 550nm visible light, sheet resistance 4.1Ω/sq) and strong EMI shielding effectiveness (average shielding effectiveness 33.6 dB at 1-18 GHz), showcasing their potential as a scalable and effective transparent EMI shielding solution.

Progress on the reduction of silver consumption in metallization of silicon heterojunction solar cells

In this work, we have demonstrated the possibility to reduce silver consumption for highly efficient SHJ cells by fine-line screen printing using low temperature paste with a variety of screens with different meshes and openings. The achieved grid fingers were characterized for the line resistance and the printed width. Extremely narrow grid fingers with 13 μm width were realized on the 520-mesh. Compared to a standard 380-mesh, finer 520-mesh produced fingers that are on average 4 μm narrower and 8% less resistive, leading to a 0.08%abs. higher efficiency whilst reducing the overall silver consumption by 15%. Complementary simulations have shown that module wire configuration is an important driver to reduce silver consumption. Integration of test samples in modules showed that 1.6 mg/W frontside paste laydown resulted in marginally lower performance than reference samples with laydown of 4–6 mg/W.

Structural development of a novel punctually supported timber building system for multi-storey construction

Though capable of allowing multi-directional spans, timber products such as cross-laminated timber are primarily utilized uni-directionally using linear supports like walls or beam elements. Recent building designs increasingly show punctual supports but with narrow column grid layouts. Support beams and narrow grids limit the design space for multi-storey timber buildings. To overcome these design limits, an integrative design concept for punctually supported timber slabs is being developed that allows for large spans and irregular column layouts. Therefore, engineering methods are integrated in the architectural design of the building components, such as plates, columns, and their connections. The developed slab system combines hardwood and softwood materials in a sandwich construction. The plates have a tailored internal topology considering the force flow in the slab. A plate-to-plate connection design is evaluated through mechanical tests, which also serve as calibration for the global structural model. The research findings are validated through the design and construction of a large scale demonstrator: the ITECH Campus Lab.

Application of Doubly Connected Dominating Sets to Safe Rectangular Smart Grids

Smart grids, together with the Internet of Things, are considered to be the future of the electric energy world. This is possible through a two-way communication between nodes of the grids and computer processing. It is necessary that the communication is easy and safe, and the distance between a point of demand and supply is short, to reduce the electricity loss. All these requirements should be met at the lowest possible cost. In this paper, we study a two-dimensional rectangular grid graph which is considered to be a model of a smart grid; nodes of the graph represent points and devices of the smart grid, while links represent possible ways of communication and energy transfer. We consider the problem of choosing the lowest possible number of locations (nodes, points) of the grid which could serve as energy sources (or a source of different resources) to other nodes in such a way that we ensure reduction in electricity loss and provide safe communication and resistance to failures and increases in energy demand.Therefore, we study minimum doubly connected dominating sets in grid graphs. We show that the proposed solutions are the best possible in terms of the number of source points for the case of narrow grid graphs and we give upper and lower bounds for the case of wide grid graphs.

Senescence as the main driver of iodide release from a diverse range of marine phytoplankton

Abstract. The reaction between ozone and iodide at the sea surface is now known to be an important part of atmospheric ozone cycling, causing ozone deposition and the release of ozone-depleting reactive iodine to the atmosphere. The importance of this reaction is reflected by its inclusion in chemical transport models (CTMs). Such models depend on accurate sea surface iodide fields, but measurements are spatially and temporally limited. Hence, the ability to predict current and future sea surface iodide fields, i.e. sea surface iodide concentration on a narrow global grid, requires the development of process-based models. These models require a thorough understanding of the key processes that control sea surface iodide. The aim of this study was to explore if there are common features of iodate-to-iodide reduction amongst diverse marine phytoplankton in order to develop models that focus on sea surface iodine and iodine release to the troposphere. In order to achieve this, rates and patterns of changes in inorganic iodine speciation were determined in 10 phytoplankton cultures grown at ambient iodate concentrations. Where possible these data were analysed alongside results from previous studies. Iodate loss and some iodide production were observed in all cultures studied, confirming that this is a widespread feature amongst marine phytoplankton. We found no significant difference in log-phase, cell-normalised iodide production rates between key phytoplankton groups (diatoms, prymnesiophytes including coccolithophores and phaeocystales), suggesting that a phytoplankton functional type (PFT) approach would not be appropriate for building an ocean iodine cycling model. Iodate loss was greater than iodide formation in the majority of the cultures studied, indicating the presence of an as-yet-unidentified “missing iodine” fraction. Iodide yield at the end of the experiment was significantly greater in cultures that had reached a later senescence stage. This suggests that models should incorporate a lag between peak phytoplankton biomass and maximum iodide production and that cell mortality terms in biogeochemical models could be used to parameterise iodide production.

Microphase separation patterns in diblock copolymers on curved surfaces using a nonlocal Cahn-Hilliard equation.

We investigate microphase separation patterns on curved surfaces in three-dimensional space by numerically solving a nonlocal Cahn-Hilliard equation for diblock copolymers. In our model, a curved surface is implicitly represented as the zero level set of a signed distance function. We employ a discrete narrow band grid that neighbors the curved surface. Using the closest point method, we apply a pseudo-Neumann boundary at the boundary of the computational domain. The boundary treatment allows us to replace the Laplace-Beltrami operator by the standard Laplacian operator. In particular, we can apply standard finite difference schemes in order to approximate the nonlocal Cahn-Hilliard equation in the discrete narrow band domain. We employ a type of unconditionally stable scheme, which was introduced by Eyre, and use the Jacobi iterative to solve the resulting implicit discrete system of equations. In addition, we use the minimum number of grid points for the discrete narrow band domain. Therefore, the algorithm is simple and fast. Numerous computational experiments are provided to study microphase separation patterns for diblock copolymers on curved surfaces in three-dimensional space.

Ultimate Capacity of Diagrid Systems for Tall Buildings in Nominal Configuration and Damaged State

One of the evocative structural design solutions for tall buildings is recently embraced by the diagrid (diagonal grid) structural system. Diagrid, with a perimeter structural configuration characterized by a narrow grid of diagonal members involved both in gravity and in lateral load resistance, requires less structural steel than a conventional steel frame, provides for a more sustainable structure and has emerged as a new design trend for tall-shaped complex structures due to aesthetics and structural performance. The purpose of this study is twofold. First, to assess the optimal structural design of a diagrid tall-building, also compared to a typical outrigger building, focusing on the sustainability (the use of structural steel) and the structural safety and serviceability. To this aim, dierent diagrid geometries are tested and compared. Second, to provide some insight on the residual strength of diagrid structures, also in the damaged state (modelled by the elimination of diagonal grids). Both goals are accomplished using FEM nonlinear analyses.

Mechanically modulated dewetting by atomic force microscope for micro- and nano- droplet array fabrication.

Organizing a material into well-defined patterns during the dewetting process provides an attractive micro-/nano-fabrication method without using a conventional lithographic process, and hence, offers potential applications in organic electronics, optics systems, and memory devices. We report here how the mechanical modification of polymer surface by an Atomic Force Microscope (AFM) can be used to guide thin film dewetting evolution and break the intrinsic spatial correlation of spontaneous instability. An AFM is used to implement the mechanical modification of progressively narrow grids to investigate the influence of pattern size on the modulation of ultrathin polystyrene films dewetting evolution. For films with different initial thicknesses, when grid size is close to or below the characteristic wavelength of instability, the spinodal dewetting is suppressed, and film rupture is restricted to the cutting trench. We will show in this paper it is possible to generate only one droplet per gridded area on a thin film subsequent to nucleation dominated dewetting on a non-patterned substrate. Furthermore, when the grid periodicity exceeds the spinodal length, the number of droplets in predefined areas gradually approaches that associated with unconfined dewetting.

Fine line metallization by coextrusion technology for next generation solar cells

This paper introduces the application of a coextrusion printing as a contact and mask-free fine line metallization technology for direct printing of narrow grid lines with a strongly enhanced aspect ratio. Coextrusion printed grid lines enhance short circuit current and lower series resistance through a higher number of filigree fingers. The silver and sacrificial paste that merge inside the nozzle are simultaneously extruded onto the wafer and form a silver paste structure smaller than every design feature inside the nozzle. After contact firing the grid lines become as narrow as 35µm with an aspect ratio up to 0.7. A further shrinkage potential down to 23.7µm width with an aspect ratio up to 0.62 has been demonstrated. Coextrusion printed grid lines outperform screen printed grid lines in a whole slew of geometrical and optical properties. As for example grid line width and height variation is as low as ±0.5µm and the optical effective finger width is far smaller than the screen printed effective finger width. Due to these low effective finger widths the absolute effective shading of 96 coextrusion printed grid lines is less than half of the 80 screen printed grid lines. The calculated short circuit current gain, due to the lower effective shading was experimentally confirmed accordingly. Furthermore a benchmark test in a production like environment was performed. Hereby an absolute cell efficiency gain of +0.25% over screen printed metallization was confirmed and a cell efficiency gain of over +0.35% to +0.4% abs. can be assumed to be achieved by using a direct contacting coextrusion silver paste, which is comparable to state of the art screen printing pastes.

Epiphytic lichens as indicator of land-use pattern and forest harvesting in a community forest in west Nepal

Human inhabitance and agriculture have fundamentally altered global pattern of biodiversity and ecosystem processes. Therefore, integration of community-based approach is an effective conservation strategy. Community forestry is an important community-based approach, which can help in conserving local ecological assets in a sustainable manner. Lichens are known to be more sensitive indicators of ecosystem functions and disturbances than any other cryptogam and vascular plant community. Present study reports a preliminary assessment of epiphytic lichens in a community forest in Dadeldhura district, west Nepal, in order to identify potential indicator of forest health and land-use pattern. Epiphytic (corticolous) lichens were sampled from ten land-use units (LUU), using narrow frequency grids of 10 cm × 50 cm, each divided into five sampling units of 10 cm × 10 cm, on the bark of selected tree species. Quercus leucotrichophora was the dominant phorophyte followed by Pinus roxburghii, Rhododendron arboreum and Myrica esculenta. Foliose parmeloid (Parmotrema spp., Heterodermia spp., Hypotrachyna spp., Bulbothrix spp., Canoparmelia spp., Canomaculina spp.) was the most abundant lichen group, found inhabiting all the phorophytes followed by crustose, fruticose and dimorphic growth forms. Maximum diversity of parmeloid lichens was recorded on older stand of Quercus while younger stands usually harbored crustose lichens (e.g., Lecanora spp., Basidia spp.). Though the lichen diversity increased from outer fringes of the forest to the core, the vegetation stand age was not distributed in any consistent pattern suggesting unconstrained harvesting of the forest. Lichen diversity was found constrained by phorophyte determinants (stand age, aspect, and bark properties) and community harvesting of the forest.doi: http://dx.doi.org/10.3126/botor.v8i0.5555 Botanica Orientalis – Journal of Plant Science (2011) 8: 24-32

Effect of age entering feedlot and implant regimen on finishing system profitability

ABSTRACT The objective of this economic analysis was to determine the effect of lifetime implant regimen of cattle entering the feedlot as calves or yearlings on economic net returns in 2 feed price scenarios (low feed prices during 2005 vs. high feed prices during 2008) and 3 carcass grid-pricing scenarios [wide ($23/45.4 kg of HCW), typical ($8/45.4 kg of HCW), and narrow ($1/45.4 kg of HCW) Choice-Select price spreads]. Cattle in Exp. 1 were primarily Angus in a spring calving season; cattle in Exp. 2 were predominantly Beefmaster in a fall calving season. Fifty percent of the calves were sent to finishing after preconditioning (CLF), and the other 50% were placed on pasture for 133 d before finishing (YRLNG). One-half of each feeding group received an aggressive implant regimen (AGG), whereas implantation of the remaining calves was delayed until the mid-point of the finishing period (DLY). Finishing cattle as YRLNG increased net return compared with CLF in Exp. 1 with narrow and typical grids at low feed prices (P ≤ 0.03) and across grid-price scenarios (P ≤ 0.03) at high feed prices. Net return of AGG was increased (P ≤ 0.02) compared with that of DLY at both the narrow and the typical Choice-Select spreads in Exp. 1. Largely because of the lack of differences in carcass characteristics in Exp. 2, there was no effect (P ≥ 0.16) of finishing age or implant protocol on net return. Regardless of effects on carcass QG, management that increased HCW led to increased net returns at all but the widest Choice-Select spreads.

Diversity and distribution of terricolous lichens as indicator of habitat heterogeneity and grazing induced trampling in a temperate-alpine shrub and meadow

Lichens are among the most sensitive biomonitors of ecosystem health and human induced disturbances. Terricolous lichens of Chopta–Tungnath (Garhwal, western Himalaya, India) were analysed for their ability to indicate habitat variability and disturbances induced by livestock grazing. Terricolous lichens were sampled from 12 sites, distributed across the three macrohabitats between 2,700 and 4,001 m, using 50 × 10 cm narrow frequency grids having five 10 × 10 cm sampling units. The terricolous lichen community of the area constituted, 20 species belonging to 10 genera, five families and four growth forms. Altitude and relative humidity were the major habitat factors found influencing the terricolous lichen community of the landscape. Fruticose and compound soil lichen growth forms were found indicative of habitat disturbance largely caused by grazing induced trampling. Terricolous lichen diversity of the area was delimited by grazing pressure at mid-altitudes (3,000–3,400 m) and by decreasing soil cover at higher altitudes (>3,400 m).

Exceptional Points in a Microwave Billiard with Time-Reversal Invariance Violation

We report on the experimental study of an exceptional point (EP) in a dissipative microwave billiard with induced time-reversal invariance (T) violation. The associated two-state Hamiltonian is non-Hermitian and nonsymmetric. It is determined experimentally on a narrow grid in a parameter plane around the EP. At the EP the size of T violation is given by the relative phase of the eigenvector components. The eigenvectors are adiabatically transported around the EP, whereupon they gather geometric phases and in addition geometric amplitudes different from unity.

Predicting supercontinuum pulse collisions with simulations exhibiting temporal aliasing

Interactions between supercontinuum (SC) light pulses, produced by the propagation of rapidly sequenced picosecond pump laser pulses along a photonic crystal fiber, result in spectral broadening, which we attribute to interpulse soliton collisions. This phenomenon was measured experimentally, following our observation of spectral broadening in numerical simulations that exhibit so-called "pulse wraparound" or "temporal aliasing." This occurs in simulations with narrow time grids: as early parts of the SC pulse leave the computational time domain, they "reenter" at the beginning and so interact with later parts of the evolving SC pulse. We show that this provides an effective model to predict the experimentally observed spectral changes.

Improved data structures for the orthogonal range successor problem

Let P be a set of n points that lie on an n × n grid. The well-known orthogonal range reporting problem is to preprocess P so that for any query rectangle R, we can report all points in P ∩ R efficiently. In many applications driven by the information retrieval or the bioinformatics communities, we do not need all the points in P ∩ R , but need only just the point that has the smallest y-coordinate; this motivates the study of a variation called the orthogonal range successor problem. If space is the major concern, the best-known result is by Mäkinen and Navarro, which requires an optimal index space of n + o ( n ) words and supports each query in O ( log n ) time. In contrast, if query time is the major concern, the best-known result is by Crochemore et al., which supports each query in O ( 1 ) time with O ( n 1 + ε ) index space. In this paper, we first propose another optimal-space index with a faster O ( log n / loglog n ) query time. The improvement stems from the design of an index with O ( 1 ) query time when the points are restricted to lie on a narrow grid, and the subsequent application of the wavelet tree technique to support the desired query. Based on the proposed index, we directly obtain improved results for the successive indexing problem and the position-restricted pattern matching problem in the literature. We next propose an O ( n 1 + ε ) -word index that supports each query in O ( 1 ) time. When compared with the result by Crochemore et al., our scheme is conceptually simpler and easier for construction. In addition, our scheme can be easily extended to work for high-dimensional cases.

The Dynamics of Risk-Neutral Implied Moments: Evidence from Individual Options

We study the estimation, the dynamics, and the predictability of option-implied risk-neutral moments (variance, skewness, and kurtosis) for individual stocks from various perspectives. We first show that it is in the estimation of the higher moments essential to use an interpolation with a narrow grid as well as a wide interval. We show that implied moments are well explained cross-sectionally by a number of firm characteristics. We use the characteristics that have been shown to exhibit correlation with expected returns (like size and the market-to-book ratio of equity). In a next step, we investigate the joint dynamics of the three moments in a vector autoregressive model. We find that the moments are significantly linked to each other over time. Finally, adding exogenous variables to the vector autoregression improves the explanatory power of our model even further. Granger causality tests show significant differences between the three implied moments.

Bipedal Locomotion of Bonnet Macaques after Spinal Cord Injury

Experimental studies concerning the analysis of locomotor behavior in spinal cord injury research are widely performed in rodent models. The purpose of this study was to quantitatively evaluate the degree of functional recovery in reflex components and bipedal locomotor behavior of bonnet macaques (Macaca radiata) after spinal contusive injury. Six monkeys were tested for various reflex components (grasping, righting, hopping, extension withdrawal) and were trained preoperatively to walk in bipedal fashion on the simple and complex locomotor runways (narrow beam, grid, inclined plane, treadmill) of this investigation. The overall performance of the animals'motor behavior and the functional status of limb movements during bipedal locomotion were graded by the Combined Behavioral Score (CBS) system. Using the simple Allen weight-drop technique, a contusive injury was produced by dropping a 13-g weight from a height of 30 cm to the exposed spinal cord at the T12-L1 vertebral level of the trained monkeys. All the monkeys showed significant impairments in every reflex activity and in walking behavior during the early part of the postoperative period. In subsequent periods, the animals displayed mild alterations in certain reflex responses, such as grasping, extension withdrawal, and placing reflexes, which persisted through a 1-year follow-up. The contused animals traversed locomotor runways--narrow beam, incline plane, and grid runways--with more steps and few errors, as evaluated with the CBS system. Eventually, the behavioral performance of all spinal-contused monkeys recovered to near-preoperative level by the fifth postoperative month. The findings of this study reveal the recovery time course of various reflex components and bipedal locomotor behavior of spinal-contused macaques on runways for a postoperative period of up to 1 year. Our spinal cord research in primates is advantageous in understanding the characteristics of hind limb functions only, which possibly mimic the human motor behavior. This study may be also useful in detecting the beneficial effect of various donor tissue-neuroprotective drugs on the repair of impaired functions in a bipedal primate model of spinal injury.

Advanced Manufacturing Concepts for Crystalline Silicon Solar Cells: Phosphorous Doping and Contact Opening Process

In this work, we report on the last investigation of POP (selective Phosphorous doping and contact Opening Process) in crystalline silicon solar cells. For the industrial solar cells, it must be very highly doped to decrease the high-contact resistance and not very shallow so that it is not perforated during paste firing, which would short-circuit the junction. We made improvement involves making separate diffusions for the different regions since the requirements are so different: a heavily doped and thick region under the contacts, a thin and lowly doped region under the passivating layer. Furthermore we opened the metal contact area to make a narrow grid lines simultaneously. As a result we could increase fill factor and reduce contact resistance by industrial process.

Le “Disposizioni anticipate di trattamento” / The advance treatment directives

Non disponibile / Not available

Four-dimensional quantum study on exothermic complex-forming reactions: Cl−+CH3Br→ClCH3+Br−

The exothermic gas-phase bimolecular nucleophilic substitution (S(N)2) reaction Cl(-)+CH(3)Br (upsilon1',upsilon2',upsilon3')-->ClCH(3) (upsilon1,upsilon2,upsilon3)+Br- and the corresponding endothermic reverse reaction have been studied by time-independent quantum scattering calculations in hyperspherical coordinates on a coupled-cluster potential-energy surface. The dimensionality-reduced model takes four degrees of freedom into account [Cl-C and C-Br stretching modes (quantum numbers upsilon3' and upsilon3); totally symmetric modes of the methyl group, i.e., C-H stretching (upsilon1' and upsilon1) and umbrella bending vibrations (upsilon2' and upsilon2)]. Diagonalization of the Hamiltonian was performed employing the Lanczos algorithm with a variation of partial reorthogonalization. A narrow grid in the total energy was employed so that long-living resonance states could be resolved and extracted. While excitation of the reactant umbrella bending mode already leads to a considerable enhancement of the reaction probability, its combination with vibrational excitation of the broken C-Br bond, (0, 1, 1), results in a strong synergic effect that can be rationalized by the similarity with the classical transitional normal mode. Exciting the C-H stretch has a non-negligible effect on the reaction probability, while for larger translational energies this mode follows the expected spectatorlike behavior. Combination of C-Br stretch and symmetric C-H, (1,0,1), stretch does not show a cooperative effect. Contrary to the spectator mode concept, energy originally stored in the C-H stretching mode is by no means conserved, but almost completely released in other modes of the reaction products. Products are most likely formed in states with a high degree of excitation in the new C-Cl bond, while the internal modes of the methyl group are less important. Reactants with combined umbrella/C-Br stretch excitation, (0, 1, 1), may yield products with two quanta in the umbrella mode.