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This paper evaluates the crashworthiness performance of concentric structures with different numbers of tubes (i.e. one to five) and cross-sectional shapes (i.e. hexagon, octagon, decagon and circle) under the multiple loadings of θ = 0, 10, 20 and 30°. An experimentally validated finite element model generated in LS-DYNA is employed to calculate the crashworthiness parameters including the specific energy absorption, maximum crush force and crush force efficiency. A total of 20 concentric structures are analyzed to explore the effects of number of tubes and cross-sectional shapes on the crushing performance. A multi-criteria decision-making method known as TOPSIS is also used to compare and rank the concentric structures in terms of crushing performance. Based on the results, the hexagonal structure including two tubes and octagonal, decagonal and circular structures including three tubes demonstrate the best results among their corresponding cross-sectional shapes. These structures show 9, 39, 38 and 39% higher specific energy absorption compared to their corresponding single tubal cases, respectively. However, in comparison to single tubal cases, they generate 4, 57, 57 and 58% higher maximum crush force, respectively. As such, the values for the improvement of the crush force efficiency are 3, 26, 25 and 21%, respectively. Furthermore, the decagonal structure including three tubes provides the highest energy absorbing characteristics as compared with all the other structures studied in this research. Meanwhile, taking into account all the multiple loading conditions, this structure shows 50% higher specific energy absorption than the hexagonal structure including single tube (as the weakest structure).

Climate variability will continue to impact the spatial and temporal variability of soil moisture in different landscapes across the world; and in turn the variability may affect crop production. Non-flood areas in the Namibian Kwalala Landscape of Zambezi (NKLOZ) region are generally relegated to second place, as somewhat marginal for the successful production of major crops such as maize (Zea mays L.). Even when flood water has receded, non-flooded areas which get affected during floods, are still avoided for crop production. This is because residual moisture following the rainy season, is suspected to fall far short of the longer growing duration of maize, to the extent that farmers are too apprehensive to grow maize in such areas. The objective of this study was to determine the effect of seasonal rainfall on spatial and temporal variability of soil moisture within the Namibian Kwalala Landscape of Zambezi (NKLOZ) ecology, and the extent to which soil moisture status and soil temperature patterns (STEPs) characterise soil type (STP) productive potential. Three sensors were setup up at 20, 40 and 60 cm landscape of the NKLOZ, after digging a one-metre trench at each site. Soil moisture and temperature data were retrieved and monitored using Decagon DataTrac 3 software. ANOVA multiple regressions were used to analyse the effects of soil depth, rainfall, and soil temperature on soil moisture. Seasonal rainfall in the NKLOZ during the growing period between October and April (2012-2015) significantly (P < 0.05) and positively affected soil moisture, both in time and space, in recharging soil moisture to sufficiently meet maize crop water requirements in the region. Although it appeared like high amounts of soil moisture sufficiency were as a result of the events of seasonal rainfall received during the growing period, anything received between mid-January and Mid-March was still below the historical minimum and maximum decadal; and in any case late for early planted maize crop. Average soil moisture data indicated for loamy soil (8.30), sandy loam (14.30) and sand at the respective sites suggested a large rainfall season-soil texture interaction. Such an interaction should inform the prudence of production of maize from the point of view of a smart or robust crop system growing planning and management. Key words: Decagon sensors, residual moisture, Zea mays

In this paper, crashworthiness performance of multi-cell conical tubes with new sectional configuration design (i.e. square, hexagonal, octagonal, decagon and circular) has been evaluated under axial and three different oblique loads. The same weight conical tubes were comparatively studied using an experimentally validated finite element model generated in LS-DYNA. Complex proportional assessment (COPRAS) method was then employed to select the most efficient tube using two conflicting criteria, namely peak collapse force (PCF) and energy absorption (EA). From the COPRAS calculations, the multi-cell conical tube with decagonal cross-section (MCDT) showed the best crashworthiness performance. Furthermore, the effects of possible number of inside ribs on the crashworthiness of the decagonal conical tubes were also evaluated, and the results displayed that the tubes performed better as the number of ribs increased. Finally, parameters (the cone angle, θ, and ratio of the internal tube size to the external one, S) of MCDT were optimized by adopting artificial neural networks (ANN) and genetic algorithm (GA) techniques. Based on the multi-objective optimization results, the optimum dimension parameters were found to be θ=7.9°, S=0.46 and θ=8°, S=0.74 from the minimum distance selection (MDS) and COPRAS methods, respectively.

To acquire accurate volumetric water content (VWC) measurements from horticultural substrates using dielectric sensors, a substrate-specific calibration is critical. Calibrations typically are conducted with a substrate without plants, but water in the root system may affect soil moisture sensor readings. We investigated the effect of root growth on the measured VWC. Lettuce seedlings (Lactuca sativa L. ‘Joek Chi Ma’) were grown in 10 cm round containers (440 mL) filled with soilless substrate. Four EC-5 soil moisture sensors (Decagon Devices Inc., Pullman, WA, USA) were used to determine the effect of root system size on sensor calibration over an eight week period. Both calibration coefficients (slope and intercept) decreased (P

A new description of Penrose tiling, based on parameterization of tiling rhombuses, has been obtained. A method making it possible to describe clusters and coordination environments in Penrose tiling in terms of parameters is developed. The parameters of all possible types of the first coordination environments in Penrose tiling are found. A new proof is obtained that the form of layer-by-layer growth of Penrose tiling is a regular decagon, and the vertices of this decagon are calculated.

Specific structural repeat units can be used as quasi-unit cells of decagonal quasicrystals. So far, the most famous and almost exclusively employed one has been the Gummelt decagon. However, in an increasing number of cases Lück decagons have been found to be more appropriate without going into depth. The diversities and commonalities of these two basic decagonal clusters and of some more general ones are discussed. The importance of the type of underlying tiling for the correct classification of a quasi-unit cell is demonstrated.

Optimizing irrigation management requires increasing the accuracy of moisture monitoring in soils or substrates, especially when it depends on electronic sensor readings. Substrates are widely used in horticulture, for growing urban ornamental plants, as well as on green roofs. Due to the lack of information about the accuracy of soil water content sensors on substrates, this research was carried out to evaluate the accuracy of the 10HS sensor (Decagon Devices Inc., Pullman, WA) to estimate soil water content (SWC) in organic substrates and mineral soil. The study was carried out at the Hydrology Laboratory of the University of Palermo. The sensors were inserted into substrates or soil in conical vessels (4 dm3 volume), drilled at the base to measure the drained volume and covered with a transparent film to limit surface evaporation. For both the substrates (A and B) and the mineral soil (C), a known amount was placed in the vessel and compacted to a value of bulk density equal to 0.177 g cm-3, 0.471 g cm-3, 1.480 g cm-3, respectively. The sensors were connected to a CR1000 datalogger (Campbell Scientific Inc., Logan, UT), which allowed the data acquisition and storage. The tests were conducted by wetting the samples with the progressive addition of known volumes of water (about 40 cm3) that were evenly distributed over the sample surface. After the end of the redistribution process of water applied to the container, the sensor readings were acquired. SWC monitoring was performed until reaching the value corresponding to the field capacity. The calibration equation recommended by the sensor manufacturer systematically underestimated the values of SWC of about 5% or more when the substrate A and B were used. On the other hand, when evaluating the sensor performance in the mineral soil (C), it was observed that the errors associated with the manufacturer's equation resulted in ±5%. Therefore, for both substrates specific calibration is necessary to improve the sensor’s accuracy, even accounting for the bulk density; on the other hand, for the mineral soil, the manufacturer's equation can be considered suitable.

The technique that conceals secret message within a digital media file imperceptibly is known as data hiding and is generally applied in various secret communications between acknowledging sides. A good scheme of data hiding must provide good visual quality of the stego-image, high embedding capacity. Maximum existing methods have either low embedding capacity or low visual quality which leads to the distortion of the stego-image. In the proposed technique, a novel data concealing method based on decagon-shaped shells is discovered to get better visual quality of the stego-image with better embedding rate. In this paper, a secret digit is concealed into every pair of pixels of the original cover image with the help of a reference matrix based on decagon-shaped shells. The results of the experiments show that this technique of data embedding not only gives better flexibility in balancing the trade-off with embedding rate and visual quality of the stego-image, but also gives high data concealing rate.

We introduce twelve operators called fuzzy quantifier-based operators. They are proposed as a new tool to help to deepen the analysis of data in fuzzy formal concept analysis. Moreover, we employ them to construct a graded extension of Aristotle’s square, namely the graded decagon of opposition.

The project “Multi-Layer Inserts” (MLI) proposes a new design for inserts used in thin-walled CFRP structures. The proposed inserts consist of multiple thin metal sheets and is build up simultaneously with the laminate in an intrinsic hybridization process, eliminating time-consuming post-processing steps. Furthermore, at equal weight, such inserts greatly increase the bonding area between metal and CFRP in comparison to conventional inserts. This results in a significant increase of the loads that can be transmitted into the CFRP. The present work discusses how the shape of the metal sheets which the proposed inserts consist of influences the mechanical properties of the surrounding laminate. This influence is investigated by measuring the strain distribution during tensile tests by means of digital image correlation. The strain distributions around the following three different MLI design approaches are compared: An elliptical metal sheet, which is expected to be ideal in terms of mechanical performance of the overall structure; a cross-shape metal sheet representing a production-driven simplification which only requires the ability to perform cuts in individual tows perpendicular to the laying direction and can be performed by state-of-the-art AFP systems; and lastly, a compromise between manufacturability and achieved mechanical performance, a decagonal metal sheet design, which requires angled cuts of the fiber tows. It is shown, that the decagon is able to evenly spread the strain over a larger area and is therefore able to significantly reduce the maximum strain values compared to a cross-shape metal sheet, while still being automatable.

Hollow tubes are the most important part of any structure because of their load-bearing capacity, lightweight and inexpensive manufacturing cost. One of the methods for improving the performance under quasi-static loading is to vary the cross-sectional shapes. In the real case, structures are seldom subjected to pure axial or pure bending rather they are subjected to a combination of two load cases i.e. oblique loading. In this paper, the circular cross-section was combined with four different polygonal cross-sections namely tetragon, hexagon, octagon and decagon and a total of 13 geometries were obtained. The buckling behavior of each tube was investigated numerically at various angles of inclination. Each tube was modeled in SOLIDWORKS and then was analyzed in ANSYS. Linear buckling code was used for finding the critical load at various angles ranging from 0° to 14°. The overall result was then compared and it was found that the proposed geometry can be a good alternative over conventional circular tubes in terms of load-bearing capacity at angular load.

The performance of a low-cost soil water content sensor (5TE, Decagon Devices, Inc.) for monitoring volumetric soil water content in an agricultural field was investigated. Prior to the in-field measurements, calibration methods for the sensor to correct the influences on soil temperature and electrical conductivity (EC) of the soil water were established. Dried soil collected from the agricultural field, pure water, and an in-laboratory thermostatic reservoir were used. First, calibration formulas for the soil temperature and EC were obtained using a dataset of laboratory measurements. Second, the soil water content in the field was measured using the 5TE sensor with three different calibration curves, applying: (A) no correction of EC for curves at 20 °C, (B) temperature correction only, and (C) temperature and EC corrections. The differences between the sensor and actual measurements were (1) 2.5%, (2) 2.5%, and (3) 2.2% expressed as volumetric soil water content (m3 m 3). Higher accuracy was confirmed in the 5TE-sensor measurements under condition (3) at higher EC values. Finally, we demonstrated that the 5TE sensor with the proposed calibration method is useful for monitoring soil water content in agricultural fields.

The objective of this study was to assess, under laboratory and field conditions, the performance of the Decagon 5TE and GS3 soil water sensors in estimating the soil water content of saline-alkali...

The review briefly outlines the results of authors’ theoretical research into unique hyperkagome atomic and orbital order in geometrically frustrated iridium spinel-like structures. The structural mechanism of formation of the hyper-kagome atomic order is established. It is shown that closed loops of Ir—Ir bonds represent a fundamental feature of the iridium spinel-like structures. Each loop consists of ten atoms, thus being a decagon. We assume that decagons are responsible for abnormal chemical and physical properties of crystals. A prediction is made of structural types of crystals in which the hyper-kagome atomic order can exist.

In order to investigate the energy absorption characteristics of multi-cell polygonal tubes with different cross-sectional configurations, firstly, the theoretical formulae of the mean crushing force under axial load for four multi-cell polygonal tubes were derived by combining the Super Folding Element theory with Zhang’s research results. These formulae can be used to validate the numerical model and quickly evaluate the energy absorption ability of multi-cell polygonal tubes. Furthermore, a comparative study on the energy absorption performance of eight multi-cell polygonal tubes under axial and oblique loads was conducted. The results show that all tubes have a stable mixed deformation mode under axial load. The multi-cell decagon tube has better energy-absorption ability compared with other tubes. When θ is less than 10°, all the tubes maintain a stable deformation mode, and the multi-cell decagon tube also has the biggest crushing force efficiency and specific energy absorption among these eight tubes; meanwhile compared with the results at θ=0°, the specific energy absorption of all tubes decreases by about 8%–21%, while the crushing force efficiency increases by 20%–56%. However, at large angles 20° and 30°, all of the tubes collapse in bending modes and lose their effectiveness at energy absorption.

The objective of this effort was to evaluate current commercially-available sensor technology (three sonic ranging and two NDVI sensors) for use in a ground-based platform for plant phenotyping and crop management decisions. The Global Positioning System (GPS) receiver from Trimble provided a high level of accuracy during our tests. Normalized Difference Vegetation Index (NDVI) data collected using the GreenSeeker sensors were more consistent and presented less variability when compared to the Decagon SRS sensor. The consistency could be due to the GreenSeeker system averaging readings of more rows. The tests also indicated that although sonic ranging sensor technology may be employed to obtain average plant height estimates, the technology is still a limiting factor for high-accuracy measurements at the plant level.

An effective temperature correction method for dielectric sensors is important to ensure the accuracy of soil water content (SWC) measurements of local to regional-scale soil moisture monitoring networks. These networks are extensively using highly temperature sensitive dielectric sensors due to their low cost, ease of use and less power consumption. Yet there is no general temperature correction method for dielectric sensors, instead sensor or site dependent correction algorithms are employed. Such methods become ineffective at soil moisture monitoring networks with different sensor setups and those that cover diverse climatic conditions and soil types. This study attempted to develop a general temperature correction method for dielectric sensors which can be commonly used regardless of the differences in sensor type, climatic conditions and soil type without rainfall data. In this work an automated general temperature correction method was developed by adopting previously developed temperature correction algorithms using time domain reflectometry (TDR) measurements to ThetaProbe ML2X, Stevens Hydra probe II and Decagon Devices EC-TM sensor measurements. The rainy day effects removal procedure from SWC data was automated by incorporating a statistical inference technique with temperature correction algorithms. The temperature correction method was evaluated using 34 stations from the International Soil Moisture Monitoring Network and another nine stations from a local soil moisture monitoring network in Mongolia. Soil moisture monitoring networks used in this study cover four major climates and six major soil types. Results indicated that the automated temperature correction algorithms developed in this study can eliminate temperature effects from dielectric sensor measurements successfully even without on-site rainfall data. Furthermore, it has been found that actual daily average of SWC has been changed due to temperature effects of dielectric sensors with a significant error factor comparable to ±1% manufacturer’s accuracy.

The data presented in this article are related to the research article entitled “RH-temperature phase diagrams of hydrate forming deliquescent crystalline ingredients” (Allan and Mauer, 2017) [1]. The data are water activity measurements of alcohol:water solutions (methanol:water and ethanol:water solutions at varying molar ratios) at different temperatures collected using the Tunable Diode Laser by Decagon Devices. The measured water activities of ethanol:water solutions were correlated to the initial volumetric ratios to produce polynomial equations that can be used to calculate the needed initial volumetric ratios for water activity controlled solutions. The data sets and polynomial equations are provided to enable extended analyses and applications of the data and calculations for generating and using controlled water activity solutions containing alcohol. An example application of these data is described in the research article mentioned above.

In this paper a decagon microstrip antenna for Ultra-Wide Band operation is proposed. A microstrip feed is used to feed the radiating patch. The ground plane of the antenna is defected with length below the patch. The proposed antenna is compact in size of 28 × 26 × 1.6 mm. This antenna is designed using FR4 substrate material that is readily available and cost effective. It’s reflection coefficient S11 < −10 dB 3–40 GHz. This proposed antenna operates from 3 GHz to 40 GHz covering UWB, Ku, K, Ka bands.

The positions of phosphorus in B-DNA have the remarkable property of occurring (in axial projection) at well defined points in the three-dimensional space of a projected five-dimensional decagonal lattice, subdividing according to the golden mean ratio τ:1:τ [with τ = (1+\sqrt {5})/2] the edges of an enclosing decagon. The corresponding planar integral indicesn1,n2,n3,n4(which are lattice point coordinates) are extended to include the axial indexn5as well, defined for each P position of the double helix with respect to the single decagonal lattice ΛP(aP,cP) withaP= 2.222 Å andcP= 0.676 Å. A finer decagonal lattice Λ(a,c), witha=aP/6 andc=cP, together with a selection of lattice points for each nucleotide with a given indexed P position (so as to define a discrete set in three dimensions) permits the indexing of the atomic positions of the B-DNA d(AGTCAGTCAG) derived by M. J. P. van Dongen. This is done for both DNA strands and the single lattice Λ. Considered first is the sugar–phosphate subsystem, and then each nucleobase guanine, adenine, cytosine and thymine. One gets in this way a digital modeling of d(AGTCAGTCAG) in a one-to-one correspondence between atomic and indexed positions and a maximal deviation of about 0.6 Å (for the value of the lattice parameters given above). It is shown how to get a digital modeling of the B-DNA double helix for any given code. Finally, a short discussion indicates how this procedure can be extended to derive coarse-grained B-DNA models. An example is given with a reduction factor of about 2 in the number of atomic positions. A few remarks about the wider interest of this investigation and possible future developments conclude the paper.

A Greenhouse has a different microclimate compared to the outside field. Climate parameters such as solar radiation and air temperature are important parameters that affect plant growth and productivity. This research aims to understand the relation of climate factors in the inside and outside Greenhouse, the effect of microclimate on evapotranspiration and to predict the amount og evapotranspiration inside the Greenhouse. Microclimate analysis was held in two stages, the firststage was from February 5 to March 21, 2018 and the second stage from March 19 to April 29, 2019 at the Department of Civil and Environmental Engineering, IPB University. Primary data was measured by the Decagon sensor. Solar radiation was collected using the Decagon PYR Pyranometer sensor and air temperature using the Decagon VP-4 sensor. Based on the result, the daily air temperature inside the Greenhouse was higher than that of the outside. The inside solar radiation was lower than that of outside the Greenhouse. The relative humidity fluctuated, and the air pressure was higher inside the Greenhouse. Evapotranspiration inside the Greenhouse was lower than outside and solar radiation was the most determining factor of evapotranspiration.

Soil temperature plays an important role in understanding hydrological, ecological, meteorological, and land surface processes. However, studies related to soil temperature variability are very scarce in various parts of the world, especially in the Indian Himalayan Region (IHR). Thus, this study aims to analyze the spatio-temporal variability of soil temperature in two nested hillslopes of the lesser Himalaya and to check the efficiency of different machine learning algorithms to estimate soil temperature in the data-scarce region. To accomplish this goal, grassed (GA) and agro-forested (AgF) hillslopes were instrumented with Odyssey water level and decagon soil moisture and temperature sensors. The average soil temperature of the south aspect hillslope (i.e., GA hillslope) was higher than the north aspect hillslope (i.e., AgF hillslope). After analyzing 40 rainfall events from both hillslopes, it was observed that a rainfall duration of greater than 7.5 h or an event with an average rainfall intensity greater than 7.5 mm/h results in more than 2 &deg, C soil temperature drop. Further, a drop in soil temperature less than 1 &deg, C was also observed during very high-intensity rainfall which has a very short event duration. During the rainy season, the soil temperature drop of the GA hillslope is higher than the AgF hillslope as the former one infiltrates more water. This observation indicates the significant correlation between soil moisture rise and soil temperature drop. The potential of four machine learning algorithms was also explored in predicting soil temperature under data-scarce conditions. Among the four machine learning algorithms, an extreme gradient boosting system (XGBoost) performed better for both the hillslopes followed by random forests (RF), multilayer perceptron (MLP), and support vector machine (SVMs). The addition of rainfall to meteorological and meteorological + soil moisture datasets did not improve the models considerably. However, the addition of soil moisture to meteorological parameters improved the model significantly.

Density functional theory (DFT) and the bond order-length-strength mechanism are used to investigate the electronic, bonding, and magnetic behaviours of Sc atoms adsorbed on the surface of lithium (Li) (1 1 0). The results indicate that Sc atoms form two-dimensional (2D) geometric structures including larger decagon, trapezoid decagon, decagon, octagon, and quadrangle structures on the Li (1 1 0) surface. The total magnetic moments of these structures are respectively 4.75, 1.84, 3.44, 3.32, and −0.427 μB. Further, the residual spin spectrum (RSS) correlation clearly indicates that the quadrangle structure has anti-ferromagnetic property; this finding should open up a new study direction for the design of novel 2D magnetic materials.

The design and management of irrigation systems require knowledge of soil water movement. There are few studies on soil water dynamics of Moistube irrigation (MTI) since it is a relatively new type of subsurface irrigation technology. It was hypothesised that soil texture influences soil water distribution under MTI. We determined soil water distribution, experimentally and numerically, using HYDRUS 2D/3D model for two soil textures (loamy sand and sandy clay loam). The experiment consisted of a soil box filled with soil and Moistube, supplied with water under a constant pressure head of 60 kPa, placed at 20 cm below the soil surface. Soil water content (SWC) was measured using Decagon MPS-2 sensors installed at depths of 5 cm, 10 cm, 15 cm, 20 cm, 30 cm, 40 cm and 50 cm and laterally at 10 cm, 20 cm and 30 cm over a period of 72 h. Results showed that simulated SWC closely matched (R2 ≥ 0.70 and RMSE ≤ 0.045 cm3 cm−3) observed values for all depths considered for the two soil textures. The model slightly under- or over-estimated SWC ( 0.05) between the soil water distribution in lateral and downward direction for both sandy clay loam soil and loamy sand. However, the SWC upward of the Moistube placement depth was significantly (p

Pentagonal quasigroups are IM-quasigroups in which the additional identity of pentagonality holds. Motivated by the example C(q), where q is a solution of the equation \(q^4-3q^3+4q^2-2q+1=0\), some basic geometric concepts are defined in a general pentagonal quasigroup. Such concepts are parallelogram, midpoint of a segment, regular pentagon and regular decagon with their centres. The connection between pentagonal and, much better known, GS-quasigroups is mentioned. That connection enables introduction of more geometric concepts in pentagonal quasigroups. In this article some theorems of the Euclidean geometry which use all these concepts are stated and proved in pentagonal quasigroups.

Commentators observe that Poliphilo, describing a building, gives the verbal equivalent of an architect’s model, or rather design process, making it likely that he possessed complete drawings. Reconstruction is difficult — not that the descriptions are vague, but their odd details are fragmentary. Still they provide clues to hypothesize underlying conceptions thoroughly mathematical. Detailed plans, elevations, and sections are discoverable for all Poliphilo’s principal structures: presented here is only the layout of one building. The text mentions some whole and half numbers of feet, outlining dimensions obtainable geometrically. Regular decagon constructions derived from Alberti, Vitruvius, and Ptolemy generate a series of circumscribed and inscribed circles defining walls and arcades. Formulae for their radii involve irrationals like (√5-1)/2. But the radius of the whole building and that of its central domed space are precisely 2:1, and fixable at 20 and 10 feet. For other dimensions, rational conver...

This paper presents a monopole decagon fractal patch resonator with the defected ground plane for WLAN MIMO antenna. The fractal technique on the edge of the decagon patch is used for reducing the operating frequency of the antenna. Concurrently, the defected ground plane (DGP) with a rectangular shape can reduce the mutual coupling between the radiating patches due to the suppression of coupling current. The reflection coefficient and isolation of the proposed antenna are achieving higher than −10 dB and −15 dB, respectively, which are covering the entire WLAN frequency band of 2.40–2.485 GHz. Then, the radiation results clearly perform the behavior of spatial diversity with the contrary beams from two excitation ports of the MIMO antenna.

This study proposes a novel phononic-crystal acoustic wave device (AWD). A graphene atomic structure was adopted as the main research subject, and a graphene-like structure was designed using piezoelectric material ZnO and its periodic boundary conditions were defined using the finite element method (FEM). The study conducts acoustic-wave propagation analysis in the frequency domain on the 2D graphene-like structure according to Bloch theory to understand the band gap effects generated by its natural vibration. The effects of shape transformation from a hexagonal honeycomb structure into a regular polygon were also investigated regarding the band gap phenomenon. Thus, this study compared and analyzed numerous 2D polygonal graphene-like structures with a fixed bond diameter (d = 2R =0.7 mm), bonding stick width (0.2 mm), and side length (1 mm), and observed the trends of the band gap changes under natural vibration for designing an optimal AWD; the studied 2D polygonal models were a square, and a regular hexagon, octagon, and decagon.

Establishing the soil water retention curve, SWRC or the soil water characteristic curve, SWCC, is very useful for determination of unsaturated properties of soils. However, it has been observed that SWRC of a soil is not unique and depends on various factors such as the initial moisture content, density of soil, method of compaction, soil fabric and the path (drying or wetting) adopted for establishing it. In this context, many techniques and instruments have been employed by earlier researchers for determination of the SWRC of soils. However, these techniques entail weighing of the samples during prolonged testing, manually, and hence yield discrete data points. In this situation, AquaSorp® Isotherm Generator (manufactured by Decagon Devices Inc., USA) has been found to be quite useful for continuous determination of the drying-path SWRC of fine-grained soils. This device has been primarily employed for food products, powders and amorphous materials. Hence, demonstration of the utility and limitations o...

The article expands the traditional system of concepts used in deontic logic, in order to allow the inclusion of supererogatory behaviour. This requires the development of a deontic decagon. In addition, it is shown how this decagon can be used to interpret deontic terms, e.g. in Islamic Law.

We consider a set of n identical charged pendulums and hang them from a common pivot. The electrostatic repulsive charge-charge interaction between the pairs repels the pendulums apart. The weight and the tension of the pendulums balance the coulombian repulsion stabilizing the setup to final static equilibrium. The final configuration is a horizontal n-gon inscribed in a circle of radius, R. It is the objective of our investigation to measure R as a function of mass, length and charge, {m,?,q}, of the pendulum for a number of pendulums, n, within the range of 2?n

The AC transport current loss in a YBCO polygonal arranged assembled conductor depends on its arrangement. The azimuthal magnetic field produced by the currents in neighboring tapes affects the current distribution in each tape, and it is anticipated that the AC loss reduction effect is greatest with a round form. To clarify the AC loss characteristics in a polygonal arranged YBCO assembled conductor, we investigated the influence of tape distances and the angle number in the polygon. To evaluate distance, we measured the AC losses in a YBCO hexagonally assembled conductor which was arranged with distances ranging from 0.2 mm-4.0 mm. To evaluate polygonal shapes, we compared YBCO polygonal assembled conductors which were arranged as a square, pentagon, hexagon, octagon or decagon at a distance of 0.5 mm. The experimental results show that the AC loss reduction effect is greatest when the polygon is arranged as a round shape.

A fivefold symmetric quasilattice is constructed by the self-similar transformation on Gummelt two-color decagon and a single electron tight-binding model is proposed. We reduce the Hamiltonian to five identical subsets and analyze the spectral properties. By numerical calculation, three kinds of wave functions are found, which correspond to extended, localized and intermediate states, respectively.

Despite the fact that chogakpos are part of our wonderful Kyubang(the women`s quarters in the Chosun Dynasty) culture with their own unique beauty and artistic values, there has been no scientific and objective proof of their aesthetic values. Once they are proved for their beauty through scientific analysis, they will be recognized worldwide along with our unique culture. The methodology included a review of related literature and theses along with magazines, periodicals, and Internet books. The analysis of lines parting, the dimensions of chogakpos were carried out over 108 pieces introduced in Old Pojagis by Heo Dong-hwa. As for line parting, the dimensions of chogakpos were measured to see if the golden and Geumgang ratio could be applied and to discover their unique partition ratio. As a result, there was the presence of the golden ratio applied to them with the golden curves from golden triangles and rectangles also found therein. The Yeoijumunbo confirmed that there was the golden ratio between the radius of a circle and a side of a regular decagon inscribed in the circle. The common line ratio among the squares, isosceles triangles, wanes, and overlapping rectangles was around 1:1.31, which means that there was a unique line ratio in the traditional chogakpos. Furthermore, the ratio of 1:1.31 was close to the Geumgang ratio commonly used in the traditional buildings of Korea.

For decagonal Al—Co—Ni quasicrystals, coverings based on a single decagonally shaped columnar 20 Å-cluster as well as tilings of so-called hexagon-, boat- and star-tiles are used to model the atomic structure. We introduce geometrically defined local transformation rules which enable us to replace a covering of overlapping congruent decagons by an equivalent HBS-tiling at the same scale and vice versa. Starting from an obvious one-to-one correspondence in case of idealized, perfect Penrose order, we show that there is a very similar relation also for random decagon coverings with slightly relaxed structure. The proofs given here complete our statements announced in previous work.

The structure of type I and type II modifications of Al–Co–Ni decagonal quasicrystals was studied by using the high-angle annular detector dark-field scanning transmission electron microscopy (HAADF-STEM) technique. It was found that the quasi-unit-cell should be selected as columnar decagon of 3.2 nm in diameter and 0.82 nm in height, and its center consists of a bright circle with 0.76 nm of the outer diameter, indicating that atomic distribution in the quasi-unit-cell is disordered. Lattices obtained by connecting the centers of the atom clusters in HAADF images reveal that the lattice of the type I modification is rhombic Penrose tiling and the lattice of the type II is a mixture of the rhombic and pentagonal tilings. Namely, the lattice of the type II modification is a mixture of the lattices of the type I and S1 modifications.

This paper is the last of a series of three articles presenting a classification of Vornoi and Delone tilings determined by point sets ?(?) ('quasicrystals'), built by the standard projection of the root lattice of type A4 to a two-dimensional plane spanned by the roots of the Coxeter group H2 (dihedral group of order 10). The acceptance window ? for ?(?) in the present paper is a regular decagon of any radius 0 < r < ?. There are 14 distinct VT sets of Voronoi tiles and 6 sets DT of Delone tiles, up to a uniform scaling by the factor and . The number of Voronoi tiles in different quasicrystal tilings varies between 3 and 12. Similarly, the number of Delone tiles is varying between 4 and 6. There are 7 VT sets of the 'generic' type and 7 of the 'singular' type. The latter occur for seven precise values of the radius of the acceptance window. Quasicrystals with acceptance windows with radii in between these values have constant VT sets, only the relative densities and arrangement of the tiles in the tilings change. Similarly, we distinguish singular and generic sets DT of Delone tiles.

Retrievals of LAI from inversion of canopy radiometric measurements, using the Li-Cor LAI-2000 Plant Canopy Analyzer and the Decagon AccuPar Ceptometer (a linear quantum probe) were analyzed and compared. Field data were collected from 34 sites in the boreal forest of interior Alaska, and sensitivity tests were conducted to estimate the effect of a variety of measurement conditions on the LAI retrievals. We also tested the response of estimated LAI to different values of the theoretical parameters in the retrieval algorithms. Uncertainty in the incident radiation level was magnified by the LAI retrieval, meaning that even small errors in this measurement significantly affected the LAI estimates. Changes in solar zenith angle over long data acquisition times also contributed to the errors. The most important quality control factors for accurate retrieval of LAI from field measurements were the incident radiation and solar zenith angle. A series of sensitivity tests showed that extreme values of leaf angle distribution could change LAI estimates, but our multi-angle measurements produced results consistent with a spherical leaf angle distribution. Alternative methods taken from the literature for post-processing of the data from the two instruments produced similar results for the LAI-2000, but widely different results for the Decagon AccuPar. Retrievals from the two instruments had an overall correlation coefficient r = 0.88 ,( P

The unit-cluster approach describing quasicrystalline structures by a single unit with possible ‘fat’ overlaps has mainly been worked out for the ideal case of perfect order. A general concept for corresponding random covering ensembles is still missing. As a natural framework, we introduce an ‘overlap-version’ of the well-known random tiling model in terms of relaxed cluster matching rules. We illustrate our method by a relaxed decagon determining a covering ensemble with positive configurational entropy. We characterize this coverings using equivalent underlying Penrose-type tilings, which form Hexagon-Boat-Star (HBS)-supertilings. Given an HBS-supertiling, we describe the effect of so-called bow-tie flips on corresponding decagon coverings.

The spatial variation of the coordination number on the Penrose tiling leads to suppression of the formation of macroscopic vortex configuration, usual to soft ferromagnetic films on periodic lattices, in favor of microscopic decagonal pattern. That state represents a new class of frustrated systems where the structure is aperiodic and consists of two parts: ordered, stable decagon chains and an unstable, spin-glass phase inside of the decagons. Virgin magnetizing is a two-step process in that system.

The structures of decagonal quasicrystals have been described as periodic stacks of decagonal quasicrystalline planes. Decagonal covering and Penrose tiling have been used to model the lattice structure of the quasicrystalline plane. We compare quasi-unit-cell models (decagon covering with decorated decagon) to Penrose-tile models (Penrose tiling with decorated rhombus tiles) and show that a quasi-unit-cell model can be interpreted as a Penrose-tile model with inflated rhombus tiles. For any given decagonal quasi-unit-cell model, there is a systematic way to generate the equivalent rhombus decorations of Penrose tiling. In general, the edge of the unit rhombus tiles in an equivalent Penrose decoration is shown to be τ4 times longer than the edge of the quasi-unit decagon. This equivalence can be used in computing atomic densities of quasi-unit-cell models.

We show in this paper that by applying size-effect distortions to a perfect Penrose tiling, on the basis that rhomb-edges which connect different types of vertices assume different lengths, we can obtain a diffraction pattern which shows remarkable similarity to the zero-level (h5 =0) section observed in decagonal Al71Co13Ni16. In particular a central clearly delineated decagon is observed, on the inside of which there is reduced intensity, and on the outside of which there is enhanced intensity. Such a transfer of intensity is characteristic of size-effect distortions in crystals but for these systems it is necessary to have disorder involving (at least) two types of atoms. In the present case the effect is observed with all vertices occupied by a single scatterer and the system remains topologically equivalent to the Penrose pattern with long range quasicrystallinity.

Capacitance sensors such as Decagon 10HS and 5TE are increasingly used for soil water content (θ) estimation. However, their reliability and limitations in clayey soils irrigated with saline waters have not been completely characterized under field conditions. Four levels of soil water content were combined with six levels of soil salinity in twenty-four pots to assess the performance of both sensors in a wide range of soil salinities. A simplified power-law dielectric mixing model was calibrated in the laboratory to estimate the θ of a clay loam soil from the measurements of apparent dielectric permittivity (e{open}b) performed with both sensors. The calibrated equation was subsequently validated for the estimation of θ at two depths in six irrigated salt-threatened soils with clayey textures in SE Spain. The 10HS sensor provides higher estimations of e{open}b than the 5TE. Besides, the 5TE sensor was more sensitive to soil salinity. Consequently, a different calibration was carried out for each sensor. When all the soil salinity treatments were included in the calibrations, the results were poor. However, for soil apparent electrical conductivities below 1.7dSm-1 the 5TE sensor could be calibrated with low prediction errors, and with the calibration parameters b0 and b1 very close to their characteristic values in clayey and mineral soils. In field testing, the 5TE sensors calibrated with the obtained equation provided average correct estimations with an error of ±0.05m3m-3. On the contrary, the 10HS sensor overestimated the soil water content by 0.07m3m-3 on average. The proposed simple calibration equation for the 5TE sensor can be reliably used under field conditions to estimate θ of irrigated clayey soils up to an apparent electrical conductivity of 1.7dSm-1. © 2013 Elsevier B.V., The funding for this work was provided by the Spanish Ministerio de Ciencia e Innovación through projects CGL2009-14592-C02-01 and CGL2009-14592-C02-02, and program “Juan de la Cierva” (F. Visconti) and scholarship BES-2010-036515 (D. Martínez), and Generalitat Valenciana through program Val i+d (F. Visconti). We thank the two anonymous reviewers and joint editor-in-chief for their constructive comments that improved the article.

Cluster density maximization and (maximal) cluster covering have emerged as ordering principles for quasicrystalline structures. The concepts behind these ordering principles are reviewed and illustrated with several examples. For two examples, Gummelt’s aperiodic decagon model and a cluster model for octagonal Mn–Si–Al quasicrystals, these ordering principles can enforce perfectly ordered, quasiperiodic structures. For a further example, the Tubingen triangle tiling (TTT), the cluster covering principle fails to enforce quasiperiodicity, which sheds some light on the limitations of this approach.

Field measurement of shrubland ecological properties is important for both site monitoring and validation of remote sensing information. During the May 1997 NASA Earth Observing System Jornada Prototype Validation Exercise, we calculated plot-level plant area index, leaf area index, total fractional cover, and green fractional cover with data from four instruments: (1) a Dycam Agricultural Digital Camera (ADC), (2) a LI-COR LAI-2000 plant canopy analyzer, (3) a Decagon sunfleck Ceptometer, and (4) a laser altimeter. Estimates from the LAI-2000 and Ceptometer were very similar (plant area index 0.3, leaf area index 0.22, total fractional cover 0.19, green fractional cover 0.14), while the ADC produced values 5% to 10% higher. Laser altimeter values, depending on the height cutoff used to establish total fractional cover, were either higher or lower than the other instruments' values: a 10-cm cutoff produced values

By means of high resolution electron microscopy (HREM), the orthorhombic (2/1, 1/1) approximant (a = 2.04 nm, b = 1.25 nm and c = 1.48 nm) of the decagonal quasicrystal in Ga-Mn and Ga-Fe-Cu-Si alloys was found to consist of a B-centred rectangular tessellation of the 'crown' or 'concave octagon' subunit, a binary tile composed of one thin and three fat Penrose rhombi with an edge length of 0.66 nm. Based on the atomic decoration of these Penrose rhombi, a structural model of the crown subunit and that of the Ga-Mn (2/1, 1/1) approximant have been put forward. Simulated electron diffraction patterns and HREM images compared favourably with the experimental results. Various periodic tilings of the crown subunit, either alone or intermixed with other binary tiles (hexagon, 72 degrees pentagonal star and/or decagon) were discussed and compared with a number of approximants found experimentally by HREM.