Arrangement Of Islands Research Articles

Impact of pedestrian flows on traffic delays before roundabouts

The paper examines a roundabout located in a residential district of Lviv city. The area has many attraction points, so traffic and pedestrian flow volumes are large. All approaches to the roundabout have unsignalized pedestrian crosswalks, three of which lack safety islands. Field studies were conducted on peak and off-peak periods, collecting primary indicators of traffic and pedestrian flows. Traffic flow delays were determined on the approaches to the roundabout under existing traffic conditions with the help of the PTV VISSIM software. Three options were proposed for arranging pedestrian crosswalks on approaches to the roundabout. The first option was an arrangement of safety islands on all pedestrian crosswalks. The second option was an arrangement of underground pedestrian crosswalks. The third option was the implementation of adapting traffic light control with a call button for pedestrians. Traffic simulation was carried out for all three proposed options with the finding of the delay per vehicle and the values of the average and maximum length of the queue of vehicles on the approaches to the roundabout. All three options showed better results of traffic delay than existing conditions. However, there were delays caused by the traffic flow itself. These delays are seen in the results of the simulation of option two. Traffic delays are the smallest at this option. Option one showed the highest values of traffic delays in comparison with the other two options. The advantages and disadvantages of each option for arranging pedestrian crosswalks are determined. Recommendations are given regarding the feasibility of locating various types of pedestrian crosswalks on the approaches to the roundabout. Given the research results, the best option from the view of traffic and pedestrian flows, their delays and safety is the third one.

Condensation phases in a non-Hermitian optical lattices system

We explore the condensate phase of single-species bosons in an optical lattice through the use of dissipative Bose–Hubbard models. The ground state of system possesses a real-energy, which corresponds to non-Hermitian Hamiltonians with non-reciprocal hopping phase factors. Through the application of inhomogeneous dynamical Gutzwiller mean-field theory (DGMFT), we predict a fascinating phenomenon: the ground state displays a periodic arrangement of superfluid islands amidst a Mott insulator sea. Additionally, the number of superfluid islands is proportional to the spatial period squared.

Performance of staggered bit island spacing adjustment for a SRTR BPMR system

One of the key problems facing the designer of data storage devices is how to handle the exponential rise in demand for information storage. To enhance the storage capacity of bit-patterned magnetic recording (BPMR) that stores one data bit in a single magnetic island, the spacing among bit islands, i.e., bit period and track pitch, must be reduced. However, the interference effects from both the across- and along-track directions are unavoidably increased, which leads to performance degradation. This paper proposes to utilize the proper spacing arrangement of magnetic islands for a single-reader two-track reading scheme to increase the staggered BPMR system’s storage capacity. We also study how the system performs for different distances between magnetic islands when track misregistration and media noise are present. Simulation results reveal that the staggered BPMR system with an appropriate magnetic island spacing can provide better performance than the traditional island placement, where the spacing between bit islands in across- and along-track directions is same.

Magnetic field driven dynamics in twisted bilayer artificial spin ice at superlattice angles

Geometrical designs of interacting nanomagnets have been studied extensively in the form of two-dimensional arrays called artificial spin ice. These systems are usually designed to create geometrical frustration and are of interest for the unusual and often surprising phenomena that can emerge. Advanced lithographic and element growth techniques have enabled the realization of complex designs that can involve elements arranged in three dimensions. Using numerical simulations employing the dumbbell approximation, we examine possible magnetic behaviors for bilayer artificial spin ice, in which the individual layers are rotated with respect to one another. The goal is to understand how magnetization dynamics are affected by long-range dipolar coupling that can be modified by varying the layer separation and layer alignment through rotation. We consider bilayers where the layers are both either square or pinwheel arrangements of islands. Magnetic reversal processes are studied and discussed in terms of domain and domain wall configurations of the magnetic islands. Unusual magnetic ordering is predicted for special angles that define lateral spin superlattices for the bilayer systems.

ROUNDABOUTS AS AESTHETIC ROAD SOLUTIONS FOR ORGANIZING LANDSCAPES

In the transportation systems are different types of intersections. Among them, roundabouts are considered the safest solution. The application of roundabouts is conditioned by many factors. One of them borders on area development. Roundabouts, among others, are localized in important city places, thus serve as a landmark in the city or are localized on the boundaries of areas with different communication functions, thus constituting an organizational landscape feature. Sometimes, they diversify the space of a street or close the perspective of a monotonous street. Hence, beyond the basic functions, roundabouts with the appropriate central island arrangements can also play the function of organizing the architecture of the local area. The ways and possibilities of roundabout central island arrangements are presented in this article. An interesting central island arrangement shows that roundabouts play an esthetic and organizing landscaping role.

Marine environment numerical simulation of morphological planning of land reclamation

Based on the evaluation criteria of the impact of different types of reclamation design on the natural environment of coastal waters, the environmental fluid dynamics model was used to simulate the seawater environment in 13 scenarios from three aspects: the shape of the artificial island, the size of inner lake outlet and the layout of the artificial island. The hydrodynamic force and water exchange capacity of these islands were quantitatively compared, and the effects of different artificial islands on the Marine environment were summarized. The planning morphology design guidelines are summarized in four aspects: (1) reduce the serrated steep slope shoreline, avoid forming semi-closed water, and increase the simple and smooth shoreline; (2) reduce the width of the lake mouth to increase the length of the lake; (3) choose a simple alignment parallel to the shore; (4) the design mainly focuses on the morphology of shoreline, followed by consideration of the lake mouth and artificial island arrangement.

Field‐Driven Reversal Models in Artificial Spin Ice: Field‐Driven Reversal Models in Artificial Spin Ice (Adv. Theory Simul. 7/2021)

In article number 2100109, Gary W. Paterson, Gavin M. Macauley, and Rair Macêdo evaluate models for interactions between nanoscale ferromagnetic islands in artificial spin ice under field-driven processes. The work shows how the emergent properties of a continuum of island arrangements from ‘square’ to ‘pinwheel’ are influenced in different ways by the non-Ising nature of the islands, and how the efficient modeling of these and similar systems may be improved.

Qualitative Analysis of Pattern of Finger Print in Relation to Gender and Blood Group

Identification of a person means the determination of the individuality or recognition of that person. A fingerprint system also known as dactylography, is based on the principle that the skin of the balls of the fingers and thumb is covered with characteristics ridges and grooves, the pattern of which makes absolute identification possible. These pattern have major design which enables them to be placed in group for primary classification, and a considerable amount of final detail. of branching and coalescence of ridges, of island, core and delta arrangement permitting subgrouping, and an unlimited quantity of extremely fine pore details along individual ridges. In this study an attempt has been made to analyze their correlation with blood group and gender of individuals. This prospective study was carried out over a period of 6 months (May 2019.October 2019) among 100 medical students (50 male and 50 female) belonging to the age group of 21 .25 years of GSVM Medical College, Kanpur (U.P.) India, Results show that each fingerprint is unique; loops are the most commonly occurring finger print pattern while arches are the least common. Males have a higher incidence of whorls and females have a higher incidence of loops. Loops are predominant in blood group A while whorls are more common in blood group B individuals.

Coherent X-ray spectroscopy reveals the persistence of island arrangements during layer-by-layer growth

Understanding surface dynamics during epitaxial film growth is key to growing high quality materials with controllable properties. X-ray photon correlation spectroscopy (XPCS) using coherent x-rays opens new opportunities for in situ observation of atomic-scale fluctuation dynamics during crystal growth. Here, we present the first XPCS measurements of 2D island dynamics during homoepitaxial growth in the layer-by-layer mode. Analysis of the results using two-time correlations reveals a new phenomenon - a memory effect in island nucleation sites on successive crystal layers. Simulations indicate that this persistence in the island arrangements arises from communication between islands on different layers via adatoms. With the worldwide advent of new coherent x-ray sources, the XPCS methods pioneered here will be widely applicable to atomic-scale processes on surfaces.

Spatial planning of small island to anticipating climate change effect (case study of Harapan and Kelapa Islands, Indonesia)

The vulnerability is a sequence of conditions that determine whether a hazard will lead to disaster or not. Small islands easily affected by climate change, which promotes extreme waves, sea level rise, rob floods, and other disasters. The limited area of the small islands requires integrated and sustainable management. Harapan and Kelapa Islands are some of the vulnerable islands that susceptible to climate change. The problem in this research is the lack of spatial arrangement of small islands region based on climate change adaptation. This study aims to create a model of land use for spatial arrangement of small islands, especially the land area in terms of changes in land use. The methods used in this study were analysis of land use change, analysis of climate change impacts on social, economic, and environmental conditions, and predict future land use scenarios using spatial modeling. The results showed that with increasing population growth, rising sea levels, rising temperatures and salinity, and erratic rainfall patterns, land requirements for settlements increased. The conclusion of this study is the additional area in Harapan and Kelapa islands should restrict, so the mitigation and adaptation due to the impact of climate change can be done well and the risk of disasters becomes small.

Island refuges: Conservation significance of the biodiversity patterns resulting from ‘natural’ fragmentation

The near-pristine continental-shelf islands along the remote and rugged Kimberley coast of north-western Australia are important natural refuges that have been isolated from many of the threatening processes affecting the adjacent mainland. Between 2007 and 2014, 27 of the largest of these islands were sampled for non-volant mammals, bats, reptiles, birds and vascular plants. Here, we evaluate the congruent patterns in species richness and composition among the taxonomic groups and relate these to island-wide attributes. We consider the conservation implications of the observed biodiversity patterns in the context of species replacement, nestedness and the minimum number of islands required to represent all species. While the species-area relationship was consistently supported, the effect of island isolation was observed for the non-volant mammals only. Environmental heterogeneity and spatial arrangement of islands strongly influenced species compositional patterns. We show that this pattern was largely due to species replacement among islands, rather than nestedness. These patterns reflect the greater diversity of regionally endemic species that are largely restricted to the more mesic and extensively rocky islands; whereas the drier islands typically support more widespread generalists. The combined measures of biodiversity patterns we observed indicate that all of the sampled islands have high conservation value. The conservation implications of the apparent lack of nestedness in this island system have relevance for other similar systems including fragmented landscapes.

Anisotropy Induced Switching Field Distribution in High-Density Patterned Media

We present here micromagnetic study of variation of switching field distribution (SFD) in a high-density patterned media as a function of magnetic anisotropy of the system. We consider the manifold effect of magnetic anisotropy in terms of its magnitude, tilt in anisotropy axis and random arrangements of magnetic islands with random anisotropy values. Our calculation shows that reduction in anisotropy causes linear decrease in coercivity because the anisotropy energy tries to align the spins along a preferred crystallographic direction. Tilt in anisotropy axis results in decrease in squareness of the hysteresis loop and hence facilitates switching. Finally, the experimental challenges like lithographic distribution of magnetic islands, their orientation, creation of defects, etc. demanded the distribution of anisotropy to be random along with random repetitions. We have explained that the range of anisotropy values and the number of bits with different anisotropy play a key role over SFD, whereas the position of the bits and their repetitions do not show a considerable contribution.

Investigation of writing error in staggered heated-dot magnetic recording systems

To achieve an ultra-high storage capacity, heated-dot magnetic recording (HDMR) has been proposed, which heats a bit-patterned medium before recording data. Generally, an error during the HDMR writing process comes from several sources; however, we only investigate the effects of staggered island arrangement, island size fluctuation caused by imperfect fabrication, and main pole position fluctuation. Simulation results demonstrate that a writing error can be minimized by using a staggered array (hexagonal lattice) instead of a square array. Under the effect of main pole position fluctuation, the writing error is higher than the system without main pole position fluctuation. Finally, we found that the error percentage can drop below 10% when the island size is 8.5 nm and the standard deviation of the island size is 1 nm in the absence of main pole jitter.

Growth and shape of indium islands on molybdenum at micro-roughened spots created by femtosecond laser pulses

Indium islands on molybdenum coated glass can be grown in ordered arrays by surface structuring using a femtosecond laser. The effect of varying the molybdenum coated glass substrate temperature and the indium deposition rate on island areal density, volume and geometry is investigated and evaluated in a physical vapor deposition (PVD) process. The joined impact of growth conditions and spacing of the femtosecond laser structured spots on the arrangement and morphology of indium islands is demonstrated. The results yield a deeper understanding of the island growth and its precise adjustment to industrial requirements, which is indispensable for a technological application of such structures at a high throughput, for instance as precursors for the preparation of Cu(In,Ga)Se2 micro concentrator solar cells.

A binary phase field crystal study for liquid phase heteroepitaxial growth

The liquid phase heteroepitaxial growth on predefined crystalline substrate is studied with binary phase field crystal (PFC) model. The purpose of this paper focuses on changes of the morphology of epitaxial films, influences of substrate vicinal angles on epitaxial growth, characteristics of islands growth on both sides of the substrate as well. It is found that the morphology of epitaxial films undergoes the following transitions: layer-by-layer growth, islands formation, mismatch dislocations nucleation and climb towards the film-substrate interface. Meanwhile, the density of steps and islands has obviously direct ratio relations with the vicinal angles. Also, preferential regions are found when islands grow on both sides of the substrate. For thinner substrate, the arrangement of islands is more orderly and the appearance of preferential growth is more obvious than that of thicker substrate. Also, the existing of preferential regions is much more valid for small substrate vicinal angles in contrast for big substrate vicinal angles.

Late Quaternary climate change shapes island biodiversity.

Island biogeographical models consider islands either as geologically static with biodiversity resulting from ecologically neutral immigration-extinction dynamics, or as geologically dynamic with biodiversity resulting from immigration-speciation-extinction dynamics influenced by changes in island characteristics over millions of years. Present climate and spatial arrangement of islands, however, are rather exceptional compared to most of the Late Quaternary, which is characterized by recurrent cooler and drier glacial periods. These climatic oscillations over short geological timescales strongly affected sea levels and caused massive changes in island area, isolation and connectivity, orders of magnitude faster than the geological processes of island formation, subsidence and erosion considered in island theory. Consequences of these oscillations for present biodiversity remain unassessed. Here we analyse the effects of present and Last Glacial Maximum (LGM) island area, isolation, elevation and climate on key components of angiosperm diversity on islands worldwide. We find that post-LGM changes in island characteristics, especially in area, have left a strong imprint on present diversity of endemic species. Specifically, the number and proportion of endemic species today is significantly higher on islands that were larger during the LGM. Native species richness, in turn, is mostly determined by present island characteristics. We conclude that an appreciation of Late Quaternary environmental change is essential to understand patterns of island endemism and its underlying evolutionary dynamics.

ICD Well History and Future Use in a Giant Oil Field Offshore Abu Dhabi

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 171836, “ICD Well History and Future Use in Giant Offshore Field, Abu Dhabi,” by Graham Edmonstone, Curtis Kofoed, Alfred Jackson, Shardul Parihar, Adriana Alvarez, Saad Mumtaz, and Ghassan Abdouche, Zakum Development Company, and Chris Shuchart, Christian Mayer, and Andrey Troshko, ExxonMobil, prepared for the 2014 Abu Dhabi International Petroleum Exhibition and Conference, Abu Dhabi, 10–13 November. The paper has not been peer reviewed. As part of a project that involves the use of four artificial islands to drill and complete more than 300 extended-reach-drilling (ERD) wells in a giant offshore oil field, several completion designs have been piloted for brownfield development. One well design incorporated the use of inflow-control devices (ICDs) and swell packers, which was the operator’s first use of such technology in a production well. The technology was installed in the pilot well to test inflow control and to manage future water production. Introduction The giant 1200-km2 offshore oil field is located 84 km northwest off Abu Dhabi Island and consists of a layered carbonate formation that was discovered in 1963. It has still only produced a small percentage of original oil in place, with water cut (WC) less than 15%. There have been almost 500 wells drilled in the field since field discovery. Development was based on pattern producer/injector wells, with each well using a dry tree on a wellhead platform tower. To achieve the strategic goal of increasing the production rate by approximately 40% and maintaining a plateau for up to 25 years, a brownfield development plan (UZ-750) has been generated that will use four artificial islands (Fig. 1) with large 3,000-hp land drilling rigs. The aforementioned island arrangement will allow the drilling of approximately 360 wells that will use ERD to drill horizontal laterals approximately 10,000 ft in length at measured depths up to 35,000 ft. The brownfield development plan calls for a parallel line drive for producer/injector-well pairs, to provide optimum sweep of the reservoir. The well-completion type is determined by geologically defined areas, which are differentiated by High- and low-permeability regions Faulted and fractured regions Transition regions Current (predicted) oil-water-saturation profiles The well-design process takes these into account along with sector modeling to determine well-completion design for the life of the well. Typically, wells in the crest of the field will have an ICD liner, in the near west of the field will have a predrilled liner, and in the west/ far northwest of the field will have a stimulation liner.

Repurposing Blu-ray movie discs as quasi-random nanoimprinting templates for photon management.

Quasi-random nanostructures have attracted significant interests for photon management purposes. To optimize such patterns, typically very expensive fabrication processes are needed to create the pre-designed, subwavelength nanostructures. While quasi-random photonic nanostructures are abundant in nature (for example, in structural coloration), interestingly, they also exist in Blu-ray movie discs, an already mass-produced consumer product. Here we uncover that Blu-ray disc patterns are surprisingly well suited for light-trapping applications. While the algorithms in the Blu-ray industrial standard were developed with the intention of optimizing data compression and error tolerance, they have also created quasi-random arrangement of islands and pits on the final media discs that are nearly optimized for photon management over the solar spectrum, regardless of the information stored on the discs. As a proof-of-concept, imprinting polymer solar cells with the Blu-ray patterns indeed increases their efficiencies. Simulation suggests that Blu-ray patterns could be broadly applied for solar cells made of other materials.

The complete genome sequence of Escherichia coli EC958: a high quality reference sequence for the globally disseminated multidrug resistant E. coli O25b:H4-ST131 clone.

Escherichia coli ST131 is now recognised as a leading contributor to urinary tract and bloodstream infections in both community and clinical settings. Here we present the complete, annotated genome of E. coli EC958, which was isolated from the urine of a patient presenting with a urinary tract infection in the Northwest region of England and represents the most well characterised ST131 strain. Sequencing was carried out using the Pacific Biosciences platform, which provided sufficient depth and read-length to produce a complete genome without the need for other technologies. The discovery of spurious contigs within the assembly that correspond to site-specific inversions in the tail fibre regions of prophages demonstrates the potential for this technology to reveal dynamic evolutionary mechanisms. E. coli EC958 belongs to the major subgroup of ST131 strains that produce the CTX-M-15 extended spectrum β-lactamase, are fluoroquinolone resistant and encode the fimH30 type 1 fimbrial adhesin. This subgroup includes the Indian strain NA114 and the North American strain JJ1886. A comparison of the genomes of EC958, JJ1886 and NA114 revealed that differences in the arrangement of genomic islands, prophages and other repetitive elements in the NA114 genome are not biologically relevant and are due to misassembly. The availability of a high quality uropathogenic E. coli ST131 genome provides a reference for understanding this multidrug resistant pathogen and will facilitate novel functional, comparative and clinical studies of the E. coli ST131 clonal lineage.

Biogeographic, climatic and spatial drivers differentially affect α-, β- and γ-diversities on oceanic archipelagos.

Island biogeographic studies traditionally treat single islands as units of analysis. This ignores the fact that most islands are spatially nested within archipelagos. Here, we took a fundamentally different approach and focused on entire archipelagos using species richness of vascular plants on 23 archipelagos worldwide and their 174 constituent islands. We assessed differential effects of biogeographic factors (area, isolation, age, elevation), current and past climate (temperature, precipitation, seasonality, climate change velocity) and intra-archipelagic spatial structure (archipelago area, number of islands, area range, connectivity, environmental volume, inter-island distance) on plant diversity. Species diversity of each archipelago (γ) was additively partitioned into α, β, nestedness and replacement β-components to investigate the relative importance of environmental and spatial drivers. Multiple regressions revealed strong effects of biogeography and climate on α and γ, whereas spatial factors, particularly number of islands, inter-island distance and area range, were key to explain β. Structural equation models additionally suggested that γ is predominantly determined by indirect abiotic effects via its components, particularly β. This highlights that β and the spatial arrangement of islands are essential to understand insular ecology and evolution. Our methodological framework can be applied more widely to other taxa and archipelago-like systems, allowing new insights into biodiversity origin and maintenance.