Flower Shaped Research Articles

Split ring resonator geometry inspired crossed flower shaped fractal antenna for satellite and 5G communication applications

This work suggests a fractal antenna in the shape of a crossed flower with a split ring resonator geometry. This suggested antenna serves the Sub-6 GHz 5G and satellite repeater applications for wireless devices operating in the frequency range of 4.01–4.82 and 7.6–7.94 GHz, respectively. The suggested antenna's performance parameters have been empirically confirmed by creating a printed prototype. The antenna geometry is based on a lower-cost FR4 substrate and consists of a mix of crossed floral square-shaped split-ring resonators organized in a Minkowski fractal configuration. A thorough examination of both manufactured and simulated antennas is conducted to demonstrate the uniqueness and edge over traditional dual-band antennas. The suggested fractal antenna's overall physical dimensions measure 0.90λ x 0.96λ at a lower resonant frequency. The response of the unit cell antenna is recorded when Split Ring Resonators are grouped in a fractal antenna with a flower shape. The measured findings verify that the proposed and constructed antenna has an electrical impedance bandwidth of −10 dB at lower frequency band (18.80 %, 4.01–4.82 GHz) and upper frequency band (4.41 %, 7.6–7.94 GHz) of −10 dB. The simulated and fabricated prototypes exhibit good agreement with respect to the stable gain and radiation patterns. Because of its consistent radiation efficiency in the realized resonating bands, the suggested prototype is a strong contender for 5G Sub-6 GHz and X band satellite applications.

Negative Index Metamaterial Antenna Using Flower Shaped Patch for WLAN Application

Negative Index Metamaterial Antenna Using Flower Shaped Patch for WLAN Application

Design of a flower shaped compact printed antenna for ultra-wideband communication

AbstractIn this communication, a compact flower shaped printed antenna for ultra-wideband communication is proposed. The “flower-shaped” structure is capable of transmitting UWB-band signals. The designed antenna exhibits a return loss ranging from 2.3 to 11 GHz with an 8.7 GHz central frequency and has 130% relative bandwidth. The suggested design includes a patch in the shape of a flower with several slots fed by a microstrip line. Multiple slots have been designed for better resonances at lower modes. The antenna is constructed with an FR4 substrate, and a 50 Ω A-type connector feeds it. The optimum dimensions of the designed antenna are 12 × 16 × 1.6 cubic-millimeters and 0.092λ × .12λ × 0.012λ in lambda. The proposed structure also demonstrates stable radiation patterns across the operating bandwidth. The proposed radiator has a high gain of 2.67 dBi, and an efficiency of 85%. It is compact, lightweight, and easy to make. Therefore, it can be used for UWB applications.

Flower Shaped Oscillating Heat Pipe at the thermosyphon condition: Performance at different rotational speeds, filling ratios, and heat supplies

The performance of a very effective and innovative thermal device based on Pulsating Heat Pipes (PHP) in a rotating system is studied and analysed in the paper. The appliance called a Flower Shaped Oscillating Heat Pipe (FSOHP) is developed for use in industrial sectors and is arranged in the specific shape of a flower so as to obtain homogeneous heat reception from technological processes. The capillaries, with an inner diameter of 2.7mm, were filled and tested, with HFE−7000 as a working fluid. This fluid, according to a confinement criterion based on the Bond or Garimella numbers, places the device in the range of thermosyphon operation, the description and experimental verification of which is addressed in this paper. The influence of rotational speed (0–300rpm), heat input (300–450W), and filling ratio (40–90%) on the thermal performance has been studied as an experimental research. Current research shows that a low boiling point liquid such as HFE−7000 can be used as a working fluid in a rotating system, and the thermal resistance of the process is characterised by a value of almost 100% higher compared to water. The maximum value of the heat flux value achieved was equal to 22.1kW/m2 for HFE−7000, while for water it was more than four times higher and equal to 98.4kW/m2. It was also observed that by increasing the Filling Ratio (FR) by up to 80%, the thermal resistance decreases to the lowest value of 0.05K/W in speed conditions such as above 200rpm. Results have shown that with respect to dimensionless numbers, despite going beyond the scope of the confinement criterion, FSOHP achieves a low value of thermal resistance and temperature stabilisation with characteristics very similar to those that describe standard pulsating heat pipe solutions in a stationary system. Furthermore, in a rotating system, an increase in heating power improves the thermal efficiency of the device only for FR >70%, while in a stationary system, an increase in the power supply range studied is always associated with a decrease in thermal resistance, regardless of the FR.

Low Profile Textile Flower Shaped Antenna for Ultra Wideband Applications

Low Profile Textile Flower Shaped Antenna for Ultra Wideband Applications

Fabrication of nitrogen doped and hierarchically porous carbon flowers for CO2 adsorption

Porous carbon with specifically designed structure as CO2 adsorbent is a very attractive and interesting research topic. In this study, we presented the synthesis and CO2 adsorption of flower shaped porous carbons. Flower-like hydrochar derived from the hydrothermal reaction of glucose, cobalt sulfate, and hexamethylenetetramine was used as the precursor, which was converted to carbon flower during CO2 activation. The flowers had hierarchically macro-meso-microporous structure. Interspaces and voids were formed by assembly of the petals, and the petals were distributed with pores of different scales. The formation mechanism of, and influences of various synthesis parameters on the flower shape were studied and analyzed. The carbon flowers exhibited surface area of 422−691 m2/g, and very high nitrogen content of 9.31–11.91 wt%. CO2 adsorption performances of the carbon flowers were also studied. Influences of the textural properties and doped nitrogen on the adsorption performances were investigated. The experiment results demonstrated that nitrogen doping showed positive effects on CO2 uptake at 1 bar, and had strong influence on the CO2/N2 selectivity.

Ion transfer channel network formed by flower and rod shape crystals of hair hydrolysate in poly(vinyl alcohol) matrix and its application as anion exchange membrane in fuel cells

Ion transfer phenomena occurring in nature are known to be most efficient. Many efforts have been made to mimic such phenomena, especially in the area of energy transfer. Proteins consisting of various amino acids are known to be the fundamental materials behind these phenomena. In the current study, an effort was made to extract proteinaceous material from human hair bio-waste by a green chemical-free thermal hydrolysis process. A simple heat treatment of the human hairs in presence of water led to the formation of a water soluble material, which was called hair hydrolysate (HH), contains 70 wt% proteinaceous material. It was utilized for the fabrication of poly(vinyl alcohol) (PVA) matrix-based anion exchange membrane (AEM). Presence of 27 wt% charged amino acids and 19 wt% polarizable amino acids in the HH provided effective charge transfer sites. 7 wt% arginine present in the HH, having continuous delocalized net positive charge helped the membrane to be stable in highly alkaline conditions, which was confirmed by an indirect analysis of alkaline stability. Formation of rod and flower shaped crystal morphology by the HH in glutaraldehyde crosslinked PVA matrix, created a continuous channel network at higher loadings, which provided a simple path for ion transfer, achieving OH− conductivity of 7.46 mS/cm at 70 °C. Swelling of the PVA matrix was minimized by annealing of the HH loaded sample, which resulted in reduction of ionic conductivity to 6.16 mS/cm (at 70 °C). At the same time, improvement in the properties like increase in thermal, mechanical and thermo-mechanical stability, reduction in water uptake, %swelling and methanol permeability was observed. The selectivity of the membrane was increased to almost a decimal place. Thus, the HH obtained from simple green thermal hydrolysis of human hair bio-waste is a cheap material, which is found to be suitable as ion conductive material for alkaline fuel cells.

A Flower Shaped Frequency Selective Surface for WLAN Screening Applications

This communication presents a single flower shaped resonator frequency selective surface (FSS) unit cell with stable oblique angles of incidence for both horizontal and vertical polarizations. The proposed FSS structure which can impede the frequencies from 3GHz to 6GHz at 3dB insertion loss is presented. The proposed FSS comprise an improved decagon to form a flower-shaped structure that exhibits single narrow stop band characteristics. The flower shaped FSS acts like a band-stop filter with center frequency of 4.8 GHz and notch band frequency ranging from 4.2GHz to 5.3GHz at 10dB insertion loss and 320MHz bandwidth at 20dB insertion loss. The designed FSS can use for shielding of public safety WLAN frequency. We present the equivalent circuit model and the surface current distribution to illustrate the resonance characteristics of the miniaturized FSS. To validate the design and simulation results, the proposed FSS is fabricated and tested in a semi-anechoic chamber

A Compact Flower‐Shaped Printed Monopole MIMO Antenna for Wideband Applications

AbstractThis paper presents a 2 × 1 flower‐shaped (FS) multiple‐input multiple‐output (MIMO) monopole antenna with enhanced bandwidth and compact dimensions for modern wireless wideband applications. The proposed FS‐MIMO antenna is formed by merging multiple ellipses, each of which has a different value of semimajor axis length and eccentricity. These ellipses are used to obtain resonances at different frequencies, which cumulatively give a wideband behavior. The antenna characteristics such as reflection coefficient (S11), peak gain, surface current distribution at different resonating frequencies, and 2‐D radiation patterns are investigated. The measured impedance bandwidth (for S11 below—10 dB) of the implemented antenna is around 126% (2.52–11.12 GHz). The measured peak gain varies from 2.16 to 6.57 dB in the entire impedance bandwidth. Furthermore, the measured values of diversity performance parameters such as envelope correlation coefficient, diversity gain, total active reflection coefficient, and mutual coupling (S21) are found within their acceptable limit. The more compact dimensions of 22 × 24 mm2 (or about 0.15λ0 × 0.16 λ0) as compared to the latest state‐of‐art along with the good diversity performance makes the proposed antenna a capable contender for antenna structures supporting wide impedance bandwidth wireless applications. The proposed antenna shows the good matching characteristics under various scenarios such as an extended ground plane, USB connector, and device housing (both vertical and horizontal).

Isolation Improvement of MIMO Antenna Using a Novel Flower Shaped Metamaterial Absorber at 5.5 GHz WiMAX Band

This brief demonstrates the use of metamaterial absorber (MA) to achieve high isolation between two patch antennas in a 2-element multiple-input–multiple-output (MIMO) system operating at 5.5 GHz resonant frequency useful for WiMAX application. The proposed flower shaped MA, designed on a $9\times 9$ mm2 FR-4 substrate with 1 mm thickness, exhibits near unity normalized impedance at 5.5 GHz with an absorptivity of 98.7%. A four element array of the MA is arranged in the form of a line in the middle of the two radiating patches in order to suppress the propagation of surface current between them at the operating frequency. Using the proposed flower shaped MA, an isolation of nearly 35 dB is achieved. The MIMO structure is studied in terms of return loss, isolation, overall gain, radiation pattern, envelope correlation coefficient (ECC), diversity gain (DG), total active reflection co-efficient (TARC), etc. The structure is finally fabricated and measured to show good agreement with the simulated results.

Flower Shaped Gold Nanoparticles: Biogenic Synthesis Strategies and Characterization.

Microbes can serve as mediators for the fabrication of complicated nano-structures, obviating the tedious and time-consuming methods of synthesis. The shape of a nanoparticle has a very prominent role in defining the functionality in prospective arenas. So, the flower shaped nanoparticles are in focus nowadays due to their enhanced electrocatalytic and optical properties as compared to the spherical ones. We present the biosynthesis of flower shaped gold nanoparticles by Bacillus subtilis RSB64 and process parameters optimization using central composite design. The two well-separated scattering spectra showing absorption peaks at 540nm and 750nm indicate the presence of anisotropic gold nanoparticles and the results were corroborated by transmission electron microscopy analysis. The presence of gold nanoparticles was further confirmed by energy dispersive X-ray studies. The functional groups responsible for the stability of gold nanoparticles were predicted by Fourier transform infrared spectroscopy. The gold nanoparticles biosynthesis were collective effects of three experimental process parameters viz pH, temperature and precursor concentration. These three parameters were statistically optimized wherein pH 11.0, substrate concentration 1:1 (v/v) and temperature of 50°C resulted in the synthesis of stable flower shaped gold nanoparticles of 50nm size. The results indicated the tailored biosynthesis of gold nanoparticles with a flower like morphology by multi process parameter analysis to finalize robust conditions for the synthesis using B. subtilis RSB64. These gold nanoflowers demonstrate increased surface area efficiency/reactivity and could be employed for sustained and controlled delivery of drugs.

Fabrication and Characterization of Dye-Sensitized Solar Cells Based on Flower Shaped ZnO Nanostructures.

Herein, we report a facile synthesis, characterization and dye sensitized solar cell (DSSC) application of flower-shaped ZnO nanostructures. The flower-shaped ZnO nanostructures were synthesized by low-temperature hydrothermal process and characterized in detail by several techniques. The detailed morphological studies confirmed that the flower-shaped structures are formed by the accumulation of several nanoneedles which are axially arranged through their bases in a special fashion that they made flower-like morphologies. The compositional, structural and optical characterizations revealed that the synthesized flowers possess high purity, well-crystallinity with the wurtzite hexagonal phase and good optical properties. The synthesized flower-shaped ZnO nanostructures were used as photoanode to fabricate DSSC which attained a reasonable solar to electrical conversion efficiency of ~1.1%, open-circuit current (VOC) of 0.611 V, short circuit current (JSC) of 3.53 mA/cm2 and fill factor (FF) of 0.51.

A Novel Electrochemical Sensor Based on Flower Shaped Zinc Oxide Nanoparticles for the Efficient Detection of Dopamine

A Novel Electrochemical Sensor Based on Flower Shaped Zinc Oxide Nanoparticles for the Efficient Detection of Dopamine

A surface expressed alkaline phosphatase biosensor modified with flower shaped ZnO for the detection of chlorpyrifos

Abstract A simple and rapid Chlorella sp. surface expressed alkaline phosphatase (AP-algae) biosensor modified with flower shaped ZnO nanoparticles for the determination of chlorpyrifos in an aqueous medium was developed. The detection principle was based on the inhibition of AP-algae in presence of chlorpyrifos. Enzyme would dephosphorylate the phosphate monoester of substrate 2-phospho- l -ascorbic acid to release l -ascorbic acid, which was monitored using voltammetric and ISFET techniques. The presence of pesticide would inhibit AP-algae enzyme activity and hence the current magnitude decreases. The decrease in current is quantitative in nature and used for determination of concentration of the pesticide. Flower shape ZnO nanoparticles not only provide surface for adsorption of AP-algae for better immobilization but also increases electron-transfer kinetics and sensitivity of the biosensor. The voltammetric and ISFET methods could measure chlorpyrifos in the linear concentration range from 10−9 M to 10−1 M and 10−10 M to 10−3 M, respectively, with nil interference from triazophos, malathion, acephate and some metal ions. Application aspects of the proposed biosensor were demonstrated using extracted soil samples and showed excellent reproducibility and reliability.

Design and analysis of a novel tri-band flower-shaped planar antenna for GPS and WiMAX applications

This paper presents the design of a tri-band flower-shaped planar monopole antenna operating at three frequencies i.e. 1.576 (GPS), 2.668, and 3.636 GHz (Mobile WiMAX). The radiating element of the antenna is backed by a 1.6 mm thicker FR-4 substrate having a dielectric constant of 4.3. The substrate is backed by a truncated ground plane. The antenna is fed through a 50 Ω microstrip line. The flower shape of the radiating element is derived from the basic circular shape by introducing in it rounded slots of various radii. The upper part of the antenna is flower shaped while the lower part comprises a microstrip feed line and two branches, each having two “leaves” at the end. The leaves and branches contribute in the impedance matching of the lower (1.576 GHz) and middle (2.668 GHz) frequency bands. The antenna gives an acceptable simulated efficiency >70% in the three frequency bands. Suitable gains of 1.63, 2.59, and 3.23 dB are obtained at 1.576, 2.668, and 3.636 GHz, respectively. The antenna matched with a VSWR < 1.2 in the three frequency bands. The prototype of the antenna is fabricated and tested in the laboratory, and good agreement in simulated and measured results is achieved. The proposed design is a visually appealing and may find uses as an external antenna in GPS and WiMAX applications.

Studies on the Internal Ballistics of Composite Solid Rocket Propellants Incorporating Nano-Structured Catalysts

This paper deals with the analysis of burn rate using various catalysts of Iron Oxide and determining which gives the higher burn rate with low pressure variation. The Ammonium Perchlorate (AP) was obtained and ground into fine powder with the particle size ranging from 63 to 125 μm. The propellant strands were prepared with proportions by mixing AP with the binder (Hydroxyl Terminated Polybutadiene), the catalyst (Iron Oxide), curing agent (Isophorone diisocyanate) and the plasticizer (Dioctyladipate). The prepared propellant mixture was cured at around 63 deg C to get various propellant strands. The first strand was prepared with the absence of a catalyst to set an initial base of comparison with other Iron Oxide catalysts, namely, Flower Shaped, Micro and Nano, based on the size of the particles. The combustion process was carried out in a strand burner, which was in turn connected to a data acquisition system. The obtained output was analysed in the form of graphs. The burn rate was achieved by calculating the slope of the graph i.e . by calculating the difference between the highest and the lowest peak of the graph and dividing the total time by the answer. The experiment was repeated with the different catalyst types, as mentioned above, at different pressures. It was observed that the Nano shaped Iron Oxide exhibits better burning characteristics when compared to the rest with the pressure index of 0.792. In this paper, the various experiments carried out along with their procedures are explained in detail. The results obtained and the techniques used are also elaborately described in this paper.

Colloidal Assembly of Hierarchically Structured Porous Supraparticles from Flower-Shaped Protein-Inorganic Hybrid Nanoparticles.

Mimicry of biomineralization is an attractive strategy to fabricate nanostructured hybrid materials. While biomineralization involves processes that organize hybrid clusters into complex structures with hierarchy, arrangement of artificial components in biomimetic approaches has been challenging. Here, we demonstrate self-assembly of hierarchically structured porous supraparticles from protein-inorganic hybrid flower-shaped (FS) nanoparticle building blocks. In our strategy, the FS nanoparticles self-assemble via high valency interactions in combination with interfacial adsorption and compression. The flower-like shape directed robust assembly of the FS nanoparticles into chain-like clusters in solution, which were further assembled into spherical supraparticles during rotation of FS nanoparticle solution. Continuously expanding and contracting the air-water interface during rotation catalyzed assembly of FS nanoparticle clusters, indicating that adsorption and compression of the building blocks at the interface were critical. The resulting supraparticles contain hierarchical pores which are translated from the structural characteristics of individual FS nanoparticle building blocks. The protein-inorganic supraparticles are protein-compatible, have large surface area, and provide specific affinity recognition for robust protein immobilization. A variety of functional proteins could be immobilized to the porous supraparticles, making it a general platform that could provide benefits for many applications.

Flower Shaped Geminated Maxillary Nolar – Report of A Typical Case

Gemination and Fusion are irregularities in tooth development. Gemination is the attempted formation of two teeth from a single enamel organ, it has an incidence of 0.47% without sex predilection1, and it is a rare anomaly that arises when the tooth bud of a single tooth attempts to divide. Geminations more frequently affect the primary teeth, but it may occur in both dentitions, usually in the incisor region. This article reports a typical case of geminated maxillary molar giving appearance of flower radiographically.

Nonenzymatic glucose sensor based on flower-shaped Au@Pd core–shell nanoparticles–ionic liquids composite film modified glassy carbon electrodes

A novel nonenzymatic glucose sensor based on flower-shaped (FS) Au@Pd core–shell nanoparticles–ionic liquids (ILs i.e., trihexyltetradecylphosphonium bis(trifluoromethylsulfonyl) imide, [P(C 6) 3C 14][Tf 2N]) composite film modified glassy carbon electrodes (GCE) was reported. The Au@Pd nanocatalysts were prepared by seed-mediated growth method, forming the three-dimensional FS nanoparticles, where tens of small Pd nanoparticles (∼3 nm) aggregated on gold seeds (∼20 nm). The FS Au@Pd nanoparticle was a good candidate for the catalytic efficiency of nanometallic surfaces because of its flower-shaped nature, which has greater adsorption capacity. XPS analysis and zeta potential indicated that the surface of Pd atoms is positively charged, profiting the oxidation process of glucose. And ILs acted as bridge connecting Au@Pd one another and bucky gel as platform within the whole nanocomposite. So the modified electrode has higher sensitivity and selectivity owing to intrinsic synergistic effects of this nanocomposite. Amperometric measurements allow observation of the electrochemical oxidation of glucose at 0.0 V (vs. Ag/AgCl), the glucose oxidation current is linear to its concentration in the range of 5 nM–0.5 μM, and the detection limit was found to be 1.0 nM (S/N = 3). The as-prepared nonenzyme glucose sensor exhibited excellent stability, repeatability, and selectivity.