Spiral Design Research Articles

Spiral Flow Phantom for Ultrasound Flow Imaging Experimentation.

As new ultrasound flow imaging methods are being developed, there is a growing need to devise appropriate flow phantoms that can holistically assess the accuracy of the derived flow estimates. In this paper, we present a novel spiral flow phantom design whose Archimedean spiral lumen naturally gives rise to multi-directional flow over all possible angles (i.e., from 0° to 360°). Developed using lost-core casting principles, the phantom geometry comprised a three-loop spiral (4-mm diameter and 5-mm pitch), and it was set to operate in steady flow mode (3 mL/s flow rate). After characterizing the flow pattern within the spiral vessel using computational fluid dynamics (CFD) simulations, the phantom was applied to evaluate the performance of color flow imaging (CFI) and high-frame-rate vector flow imaging. Significant spurious coloring artifacts were found when using CFI to visualize flow in the spiral phantom. In contrast, using vector flow imaging (least-squares multi-angle Doppler based on a three-transmit and three-receive configuration), we observed consistent depiction of flow velocity magnitude and direction within the spiral vessel lumen. The spiral flow phantom was also found to be a useful tool in facilitating demonstration of dynamic flow visualization based on vector projectile imaging. Overall, these results demonstrate the spiral flow phantom's practical value in analyzing the efficacy of ultrasound flow estimation methods.

Impact of cross-sectional geometry on mixing performance of spiral microfluidic channels characterized by swirling strength of Dean-vortices

Mixing in a microfluidic system is challenging due to dominant diffusion effects at a microscale (low Reynolds number). In this work, we report the improvement of mixing performance in spiral microchannels of varying cross-sectional geometry and hydraulic diameter. The formation of secondary flow interactions in spiral channels, known as Dean vortices, aid the primary diffusion process. The evolution of these Dean vortices was experimentally visualized along the length of the microchannel by confocal microscopy, and then compared to numerical studies. The cross-sectional geometries of the spiral channels, especially in the case of irregular shapes such as the semi-circular and trapezoidal profiles, were found to be an important factor in tuning the strength of Dean vortices, which in turn dictate the mixing performance, as opposed to diffusion which is more prominent at lower Re. This experiment-based finding has been validated via the evaluation of swirling strength of the working fluid, obtained using a numerical study. The results thus obtained show a mixing performance greater than 90% above a Reynolds number of 20 for most spiral channel designs, making this system suitable for high throughput operation with reduced pressure drop. This work is the first to experimentally and numerically demonstrate, within this operating range (20 < Re < 277), the impact on mixing performance in curved microchannels of varying cross-sectional geometries of constant cross-sectional area, and of varying hydraulic diameters for square shaped channels. The capability of these channels to operate at a moderately high Re with enhanced mixing performance and reduced pressure drop would be of great use in large-scale industrial operations, such as complex integrated micro-reactors wherein pressure drop plays a key role.

Carbon fiber composites with 2D microvascular networks for battery cooling

Electric vehicle (EV) batteries require both thermal regulation and crash protection. A novel battery packaging scheme is presented that uses microvascular composite panels with 2D channel networks to accomplish both objectives. Microvascular carbon fiber/epoxy composite panels are fabricated by vacuum assisted resin transfer molding, with the channel network formed by post-cure vaporization of an embedded polylactide channel template. Panel cooling performance is evaluated for parallel, bifurcating, serpentine, and spiral channel designs at different coolant flow rates and channel diameter. The spiral design provides the best thermal performance, but requires high pumping pressure (>100kPa) at the flow rates needed for adequate cooling (>30mLmin−1). The bifurcating design and a network obtained by computational optimization offer much lower pressure with slightly reduced thermal performance. Channel diameter has negligible effect on cooling performance, but strongly affects pumping pressure. Computational fluid dynamics (CFD) simulations are also performed and correlate well with the experimental data. Simulations confirm that microvascular composite panels can cool typical battery cells generating 500Wm−2 heat flux below the target temperature of 40°C.

Spiral Gradient Coil Design for Use in Cylindrical MRI Systems

In magnetic resonance imaging, the stream function based method is commonly used in the design of gradient coils. However, this method can be prone to errors associated with the discretization of continuous current density and wire connections. In this paper, we propose a novel gradient coil design scheme that works directly in the wire space, avoiding the system errors that may appear in the stream function approaches. Specifically, the gradient coil pattern is described with dedicated spiral functions adjusted to allow the coil to produce the required field gradients in the imaging area, minimal stray field, and other engineering terms. The performance of a designed spiral gradient coil was compared with its stream-function counterpart. The numerical evaluation shows that when compared with the conventional solution, the inductance and resistance was reduced by 20.9 and 10.5%, respectively. The overall coil performance (evaluated by the figure of merit (FoM)) was improved up to 26.5% for the x -gradient coil design; for the z-gradient coil design, the inductance and resistance were reduced by 15.1 and 6.7% respectively, and the FoM was increased by 17.7%. In addition, by directly controlling the wire distributions, the spiral gradient coil design was much sparser than conventional coils.

REVIEW OF DESIGN STRATEGIES OF DUAL/TRI-BAND ANTENNAS FOR GPS AND IRNSS APPLICATIONS

In era of ever increasing demand of wireless communications, domain of antenna design has progressed rapidly and gained a lot of attention among researchers and academicians. Over past few decades, it has catered the needs of society and technocrats by proving itself as one of the main driving forces behind recent advancements in wireless communication. Especially in the GNSS applications, for civilian and military use, antenna design has played a vital role. Thus, a humble attempt is made in this article to provide a glance of globally used antenna for the GNSS applications. A spiral antenna. Various aspects of antenna characteristics have been described that gives insight of developments carried out in the field of spiral antenna design and important conclusions are drawn from the comparisons made for their future use. Comparative reviews between various aspects of antenna designs reveal the fact about promising performance of spiral based antenna in developing dual/tri band applications for GPS as well as IRNSS.

RF inductors with sputtered nanomagnetic films on glass substrates

Inductors utilize spiral or helical designs to enhance magnetic flux and inductance. Spiral inductors require large footprint while solenoid inductors require thick substrates to achieve adequate flux coupling. As such, both these designs impose trade offs in inductance density, Q, and frequency stability. Nanomagnetic films with stable and high permeability can enhance inductance density and correspondingly the Q factor. However, nanomagnetic films suffer from two disadvantages. They have high losses beyond 1.0 GHz. They are also sputter-deposited as thin films that are less than five microns. Therefore, the benefits of nanomagnetic films in RF inductors are not clear. Performance improvements and trade-offs in RF inductors with nanomagnetic films are analyzed through material and component-level modeling. In the first part of the paper, nanomagnetic films and properties are modeled. The inductance density and Q trade-offs with nanomagnetic films are simulated after imposing their constraints: frequency dependence and thickness of five microns. Both helical and spiral inductors are considered with and without the nanomagnetic films. The simulations show enhancement in inductance by 5× with mild degradation in Q for spiral inductors. However, the Q degraded more with solenoid inductors. Higher resistivity and ferromagnetic resonance frequency are critical to improve the performance of nanomagnetic film inductors.

Public facility design for sustainability: Participatory action research on household recycling in Hong Kong

While many researchers have pointed out that public design can increase users’ sustainable practices, how to achieve good public designs is challenging. To explore the current public design barriers and solutions to household recycling in Hong Kong, our research group, in collaboration with two Caritas Community Centres, adopted participatory action research, including questionnaires, interviews, non-participant observations, collaborative workshops and on-site iterative prototyping process, to carry out a research project. In this project, local residents, recyclers, property management officers and cleaners in five public rental housing estates were recruited to voice their views on public design for recycling. Through the results of the spiral design exploration conducted at Sai Wan Estate, this study demonstrates the validity of action research to promote the participatory design for recycling. The paper concludes with a discussion of some barriers to and experience with applying these methods to improve the practice in the context of high-rise living environments. It also provides experience and insights into action research in public design for designers, researchers and policy makers.

Unsteady three-dimensional numerical study of mass transfer in PEM fuel cell with spiral flow field

Bipolar plate design and its flow field shape have an important effect on the fuel cell performance. In this work, a FORTRAN program has been developed to investigate the effects of the channel width, the number of turns of the spiral channel and the flow direction on the reactants consumption in a proton exchange membrane fuel cell (PEMFC) with a spiral flow field design. The governing equations are discretized using the finite volume method in cylindrical coordinates. The results show that the channel-rib width ratio influences the cell performance; the higher ratio, the more important contact area between the channel and the GDL, the more reactants quantity seeped to the GDL and more uniform reactants distribution is. The increasing the spiral channel turns number improves the reactants distribution uniformity. The channel spiral shape engenders a centrifugal force which enhances the cell performances in the case when the reactants are injected from the external side of the spiral channel and ejected from its internal one.

Simulation analysis of turbine blade in 3D printing aquarium

3D printing of the flexibility is the most admirable place, no matter when or where, as long as the machine can make the abstract design of finished products or difficult to process the finished product printed out as a sample. And in the product design, through the 3D print out the entity, to more specific observation of the advantages and disadvantages of finished products, which shorten the time of many creative research and development, but also relatively reduce the defective factors. As in recent years, 3D printing technology is progressing, material adhesion, precision and parts of the degree of cooperation has increased, coupled with many parts taking into account the cost, production and other issues, and then let a lot of light load small parts or special parts choose to use 3D to print the finished product to replace. This study focuses on the plastic turbine blades that drive water in the aquarium, but the 3D printing is done by stacking. However, the general stress analysis software can set the material to analyze the deformation results of the force, nor the 3D to analyze the software. Therefore, this study first analyzes the deformation of turbine blade by software, and then verifies the situation of 3D printing turbine blade, and then compares the actual results of software analysis and 3D printing. The results can provide the future of 3D product consider the strength factor. The study found that the spiral blade design allows the force points to be dispersed to avoid hard focus.

Recoil polarization measurements

Polarization observables in photon-induced meson production off nucleons have long been recognized to hold the promise of a detailed understanding of the excited states in the excitation spectrum of the nucleon. Photon beam and proton target polarization are routinely used at the ELSA facility in the Crystal Barrel/TAPS experiment and have yielded a wealth of data on contributing partial waves and nucleon resonances. A detector study on how to complement these ongoing studies by recoil polarization measurements that offer an orthogonal approach with otherwise unmeasurable observables in the field of non-strange meson photoproduction has been performed.Building on experience with silicon detectors operated in the photon beamline environment, first possible layouts of Si detector telescopes for recoil protons were developed. Various geometries, e.g. Archimedean spiral design of annular sensors, sector shapes and rectangular sensors were studied and have been used during test measurements. A prototype for the recoil polarimeter was built and subjected to performance tests in protonproton scattering at the COSY-accelerator in Julich.

3D bioprinting of urethra with PCL/PLCL blend and dual autologous cells in fibrin hydrogel: An in vitro evaluation of biomimetic mechanical property and cell growth environment.

Urethral stricture is a common condition seen after urethral injury. The currently available treatments are inadequate and there is a scarcity of substitute materials used for treatment of urethral stricture. The traditional tissue engineering of urethra involves scaffold design, fabrication and processing of multiple cell types. In this study, we have used 3D bioprinting technology to fabricate cell-laden urethra in vitro with different polymer types and structural characteristics. We hypothesized that use of PCL and PLCL polymers with a spiral scaffold design could mimic the structure and mechanical properties of natural urethra of rabbits, and cell-laden fibrin hydrogel could give a better microenvironment for cell growth. With using an integrated bioprinting system, tubular scaffold was formed with the biomaterials; meanwhile, urothelial cells (UCs) and smooth muscle cells (SMCs) were delivered evenly into inner and outer layers of the scaffold separately within the cell-laden hydrogel. The PCL/PLCL (50:50) spiral scaffold demonstrated mechanical properties equivalent to the native urethra in rabbit. Evaluation of the cell bioactivity in the bioprinted urethra revealed that UCs and SMCs maintained more than 80% viability even at 7days after printing. Both cell types also showed active proliferation and maintained the specific biomarkers in the cell-laden hydrogel. These results provided a foundation for further studies in 3D bioprinting of urethral constructs that mimic the natural urethral tissue in mechanical properties and cell bioactivity, as well a possibility of using the bioprinted construct for in vivo study of urethral implantation in animal model. The 3D bioprinting is a new technique to replace traditional tissue engineering. The present study is the first demonstration that it is feasible to create a urethral construct. Two kinds of biomaterials were used and achieved mechanical properties equivalent to that of native rabbit urethra. Bladder epithelial cells and smooth muscle cells were loaded in hydrogel and maintained sufficient viability and proliferation in the hydrogel. The highly porous scaffold could mimic a natural urethral base-membrane, and facilitate contacts between the printed epithelial cells and smooth muscle cells on both sides of the scaffold. These results provided a strong foundation for future studies on 3D bioprinted urethra.

Systems Design on a Team Learning Process Model

Purpose: Team is a microcosm of organization. in turn, building a learning organization naturally requires how to manage team learning. in this context, the purpose of this article was to apply systems design on building a team learning process model. Method: In order to design the model, the research utilized the spiral system-design methodology, a revised version of Banathy’s systems-design process, which includes the major stages of developing a knowledge base, preparation, analysis, design, evaluation, and implementation. However, the implementation stage was not included in this study. Results: Experts' reviews on the initial team learning process model, were arrange into 'strengths' and 'improvements'. Based upon experts' reviews, the research provided a revised team learning process model in terms of input process, transformation process, output process, guidance process. Conclusion: Through the spiral system design method, the research created an ideal process centered team learning model. Based upon the outcome of the research, the following research agenda would be develop how to effectively facilitate team learning process.

Golden Spirals and Scalp Whorls: Nature's Own Design for Rapid Expansion.

This paper documents what began as an exercise in curiosity—logarithmic spiral designs abound in nature—in galaxies, flowers, even pinecones, and on human scalps as whorls. Why are humans the only primates to have whorls on the scalp? Is the formation of scalp whorls mechanical or genetic? A mechanical theory has long been postulated– the mechanical theory suggests that hair whorl patterning is determined by the tension on the epidermis during rapid expansion of the cranium while the hair follicle is growing downwards—however, this has never before, to the author's knowledge, been experimentally proven conclusively. We found, that under certain conditions, we were able to experimentally recreate spirals on the scalp to demonstrate that the basis of scalp whorls is indeed mechanical—and that logarithmic spirals may be nature’s own design for rapid expansion of organic tissues. Given our experiments only created whorls when certain conditions were satisfied (and not in others), they have given us great insight into the mechanical formation of skin whorls and the physiology of skin stretch. We believe that these findings will lead to many more advances in understanding skin dynamics and indeed the changes that occur in tissue when confronted by stretch.

Conceptual finite element study for comparison among superior, anterior, and spiral clavicle plate fixations for midshaft clavicle fracture

Open reduction internal fixation technique has been generally accepted for treatment of midshaft clavicle fractures. Both superior and anterior clavicle plates have been reported in clinical or biomechanical researches, while presently the spiral clavicle plate design has been introduced improved biomechanical behavior over conventional designs. In order to objectively realize the multi-directional biomechanical performances among the three geometries for clavicle plate designs, a current conceptual finite element study has been conducted with identical cross-sectional features for clavicle plates. The conceptual superior, anterior, and spiral clavicle plate models were constructed for virtual reduction and fixation to an OTA 15-B1.3 midshaft transverse fracture of clavicle. Mechanical load cases including cantilever bending, axial compression, inferior bending, and axial torsion have been applied for confirming the multi-directional structural stability and implant safety in biomechanical perspective. Results revealed that the anterior clavicle plate model represented lowest plate stress under all loading cases. The superior clavicle plate model showed greater axial compressive stiffness, while the anterior clavicle plate model performed greater rigidity under cantilever bending load. Three model represented similar structural stiffness under axial torsion. Played as a transition structure between superior and anterior clavicle plate, the spiral clavicle plate model revealed comparable results with acceptable multi-directional biomechanical behavior. The concept of spiral clavicle plate design is worth considering in practical application in clinics. Implant safety should be further investigated by evidences in future mechanical tests and clinical observations.

Style of Pottery Products of Ban Tao Hai in Phitsanulok Province

&lt;p&gt;The objective of this research was to investigate the history and analyze the style of pottery products of Ban Tao Hai in Phitsanulok province. The research procedure took on documentary study appeared with the stories of pottery products of Ban Tao Hai, and explore pottery products of Ban Tao Hai in the museums and those discovered in Phitsanulok province. Data analysis focused on the history, styles, decorative patterns, and marks or symbols observed. Research result demonstrated that the pottery products of Ban Tao Hai were located in the ancient kiln sites at Ban Tao Hai currently situated in the area of Ta Pakao Hai temple and Ta Pakao Hai school at Hua Raw sub-district, Amphur Muang, Phitsanulok province. It is a cluster of large kilns stacked up and lined up along the Nan River, the kilns with high-technology. The products were either earthenware or large stoneware such as jars, jugs, basins, and bowls. According to the survey and excavation on 2 April 1984 by the regional Office of Fine Arts of Sukhothai and Phitsanulok, a stack of 2 kilns was discovered, i.e. the brick-built crossdraft kilns in similar sizes called Phitsanulok Kiln 1 (PK.1) and Phitsanulok Kiln 2 (PK.2). Ban Tao Hai pottery products that the researcher found were kept in the museum and in the community, altogether 80 pieces. Most of them were not in perfect condition, and only some with perfect condition were in good storage. These 80 pieces were in 6 categories: 1) wide-mouth jar, 16 pieces; 2) flaring-mouth jar, 17 pieces; 3) basin, 2 pieces; 4) round-bottom pot, 3 pieces; 5) jarlet, 33 pieces; and 6) mortar, 9 pieces. Among them, 17 pieces were decorated with applied spiral design (Lai Kod Hoi) so called “Lai Ou”, 27 pieces with excised and impressed designs, and another 36 pieces were undecorated. They comprised 26 glazed and 54 unglazed pieces. One of the unique features of Ban Tao Hai pottery was the marks or symbols made by the potters on the body of workpieces. The study revealed 22 marked and 54 unmarked pieces of pottery.&lt;/p&gt;

DESAIN TARI PIRING LENGGOK SI ANAK DAGANG KOREOGRAFER ISKANDAR MUDA

Trade sianak plate swing dance is one dance originating from the Minangkabauthat developed in the city of Medan. The purpose of this study is to discuss theswing sianak Plate Dance Choreographers Trade Iskandar Muda views fromForm, Top Design, Design Floor.In the discussion of this study used the theories related to the topic of study suchas the Theory of Forms of Sal Murgiyanto Dance, Top of the Design Theory andDesign Theory Sudarsono floor of La MeriWhen the study to discuss Plate Dance Dance Choreographer swing sianak TradeIskandar Muda was conducted for two months. Place of research conducted at theStudio Dance Medan State University Faculty of Language and Art jl. IskandarWilliam. Data collection techniques including observation, interviews, literaturestudies and doumentasi, which is then analyzed by qualitative descriptive method.Based on the results of research conducted showed that dance Lenggo plate sianakthis trade is a dance that takes the movements of the Minang community activitiesare generally farmers, and developed into a new creation dance. There aremovements born / inspired by the movements of the flora, fauna and koreomatik.Form of motion which is divided into three energy intensity (weak, medium,strong), space (small and large), and time (slow medium, fast). There are 8 designon frequent / dominant in this dance that Spiral design, symmetrical,asymmetrical, curved, delayed, flat, low, and advanced. There are two designs onthe dance floor that occurred of which this is the floor design of straight lines andcurved lines flooring design. This dance had several times shown by the studiowidatra overseas parts of Asia and Europe, namely: Performance CompetitionCultural North Sumatra on "44" in Debrecen Flower Carnival in on Hungary andBelgrade Serbia Central Europe, and IMT-GT Prince of Songkla University ofThailand, performances which was attended by three countries, namely Malaysia,Thailand and Indonesia Hence dance swing plate sianak this trade very existencein the city of Medan. There are designs and forms of motion which draw heavilyon swing dance sianak Trade Plates Choreographer's Iskandar Muda.

Stage-Dependent DSP Operation Range Clipping-Induced Bit Resolution Reductions of Full Parallel 64-Point FFTs Incorporated in FPGA-Based Optical OFDM Receivers

The fast Fourier transform (FFT) is the fundamental algorithm at the heart of an optical OFDM (OOFDM) transceiver. The high digital signal processing (DSP) complexity has become one of the most significant obstacles to experimentally demonstrating real-time high-capacity OOFDM transceivers. In this paper, stage-dependent clipping of FFT DSP operation dynamic range is proposed and extensively explored, for the first time, based on which an improved stage-dependent minimum bit resolution map is numerically identified by taking into account the DSP operation dynamic range-clipping and precision of FFT DSP operations. The validity and high accuracy of the identified minimum bit resolution map is experimentally verified in 25 km SSMF OOFDM transmission systems based on intensity modulation and direct detection. Experimental results show that, compared to a previously reported FFT stage-dependent bit resolution map including the FFT DSP operation precision only, the improved minimum bit resolution map offers significant bit resolution reductions of up to 3-bits for full-parallel pipelined 64-point FFT architectures. As a direct result, an approximately 30% reduction in FPGA logic resource usage is achievable compared to the spiral FPGA design.

Dispenser printed capacitive proximity sensor on fabric for applications in the creative industries

This paper reports a planar capacitive proximity sensor fully dispenser printed on a standard polyester woven fabric using conductive ink. Dispenser printing is a new digital printing technique offering the advantages of complete geometric design flexibility and the ability to direct write multilayer devices without requiring bespoke tooling. A dispenser printer is also capable of printing a wide range of ink viscosities encompassing those of inkjet and screen printable inks. Previous research has demonstrated the principle of using proximity sensors for human interaction but none of them are fabricated directly on fabric. In this research, the proximity sensor is dispenser printed directly onto the fabric with an optimised loop electrode design which uses 76% less conductive ink while still offering 90% of the detection range when compared with a standard filled electrode design. The loop design also has the highest detection coefficient (maximum detection distance versus the conductive area of the sensor) of 0.23 compared with 0.06 and 0.1 for the investigated filled and spiral designs, respectively. In addition, the ratio of the track width to the width of the entire sensor is investigated showing 1/16 as being the most suitable ratio for the proximity sensor printed on fabric. Proximity sensors with loop widths ranging from 10mm to 400mm are evaluated. The maximum detection distance is 400mm when the largest sensor is used and the linearity of the sensing circuit is 0.79.

Multi‐layer archimedean spiral antenna fabricated using polymer extrusion 3D printing

This work describes the design, fabrication, and testing of an Archimedean spiral or spiral antenna using polymer extrusion 3D printing of polycarbonate base material. The spiral antenna design was simulated using CST Microwave Studio®, and the resulting 3D printed antenna characterized in terms of return loss, directivity, and polarization. The antenna design was embedded into a 3D printed structure using a unique ultrasonic method while a ground plane was inserted through a thermal embedding process. These fabrication methods provide process flexibility, which allows multiple conductive antenna layers to be additively constructed in a single build sequence. The method described can be used to create unique electromagnetic structures such as waveguides directly in a 3D printed dielectric part. The spiral antenna was tested with three variations of microstrip feed line used to match 50Ω impedance and introduce a 180° phase shift between the two arms of the spiral. These include a Duroid balun attached to feed of the antenna after fabrication, a Duroid balun embedded into the polycarbonate during fabrication, and the same microstrip design fabricated out of copper mesh and embedded into the structure using the polycarbonate as a dielectric substrate. The results of these three approaches will be discussed. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:1662–1666, 2016

Spiral-shaped reactor for water disinfection

Chlorine-based processes are still widely used for water disinfection. The disinfection process for municipal water consumption is usually carried out in large tanks, specifically designed to verify several hydraulic and disinfection criteria. The hydrodynamic behavior of contact tanks of different shapes, each with an approximate total volume of 50,000 m3, was analyzed by solving turbulent momentum transport equations with a computational fluid dynamics code, namely ANSYS fluent. Numerical experiments of a tracer pulse were performed for each design to generate flow through curves and investigate species residence time distribution for different inlet flow rates, ranging from 3 to 12 m3 s−1. A new nature-inspired Conch tank design whose shape follows an Archimedean spiral was then developed. The spiral design is shown to strongly outperform the other tanks’ designs for all the selected plug flow criteria with an enhancement in efficiency, less short circuiting, and an order of magnitude improvement in mixing and dispersion. Moreover, following the intensification philosophy, after 50% reduction in its size, the new design retains its properties and still gives far better results than the classical shapes.