Dual Feed Research Articles

Effect of efficient structural tuning on the microstructure, corrosion resistance, and wear performance of AlCoCrFeNi/AT13 composite coatings

This study developed a rapid structure control technique for AlCoCrFeNi/AT13 (Al₂O₃–13 % TiO₂) composite coatings using plasma spraying and dual powder feeding. Four coatings were fabricated: pure HEA, HEA-D (dispersed), HEA-S1 (multilayer with outer HEA), and HEA-S2 (multilayer with outer AT13). The introduction of AT13 altered the internal stress distribution and enhanced corrosion resistance by lowering the electrochemical reaction rate. In layered coatings (HEA-S1, HEA-S2), the AT13 interlayer barrier reduced corrosion tendency. Additionally, pure HEA coatings exhibited adhesive wear. While HEA-D coatings experienced abrasive wear as AT13 particles improved plastic deformation and interface shearing. HEA-S1 reduced strain and wear via an internal AT13 layer. HEA-S2 achieved superior abrasion resistance through an outer AT13 layer, exhibiting typical abrasive wear mechanisms.

Evaluation of the Blood Feeding Preference of Aedes aegypti (Diptera: Culicidae) when Offered Diabetic and Non-Diabetic Blood.

Aedes aegypti (L.,1762) is a primary vector of arboviral infections like dengue, yellow fever, Zika. Female mosquitoes are influenced by various physical and chemical cues from host when blood feeding, e.g., they find some individuals with certain blood types or certain conditions more attractive than others. This study determined whether Ae. aegypti shows a preference when offered blood from a patient with diabetes mellitus (DM), an endocrine disorder associated with abnormal glucose metabolism, compared to healthy blood from non-DMs. In the dual feeding experiments, forty newly emerged female mosquitoes were provided with two blood feeding systems with blood from a non-diabetic (healthy) and diabetic patient using artificial feeders. Blood from 12 diabetic and 12 non-diabetic patients was matched by ABO blood type (e.g., diabetic type O blood was compared with non-diabetic type O blood). The number of mosquitoes that landed and fed from each membrane was counted every 2min for thirty minutes. Ae. aegypti species significantly preferred for blood from non-diabetic individuals (50-65% among the different blood type groups) compared to blood from diabetic individuals. Using multiplex allele-specific PCR it was also determined that, Ae. aegypti significantly preferred the O blood group regardless of blood sugar level compared to others. Ae. aegypti has less preference for diabetic blood to non-diabetics. Regardless people affected with this condition need to take preventive measures to reduce mosquito bites as they tend to have weaker immune systems and can experience more severe cases of dengue.

Active prediction compensation strategy: A new positioning compensation technique for improving the accuracy of the dual ball screw feed mechanism under load

The dual ball screw feed mechanism (DBSFM) is commonly employed in high-end machining applications. However, its accuracy is challenging to enhance due to variations in the axial stiffness of the dual actuators under load, making geometric error compensation (GEC) difficult. To address this, our research establishes a comprehensive error model that integrates geometric error and load-induced error (LIE) to improve feeding accuracy. The axial stiffness matrix of the DBSFM is identified using motor current information, and an active prediction error matrix is defined based on the geometric error model, milling force model, and axial stiffness matrix. We propose and analyze the active prediction compensation (APC) strategy as a new method to enhance accuracy under load. Experimental validation using a gantry-type machine tool demonstrates that the APC strategy can reduce the positioning error of the DBSFM to ±2 μm under load, representing significant improvements over the established GEC method. Specifically, the APC strategy achieves a 53.07% and 57.04% enhancement in accuracy along the two axes. This work illustrates the effectiveness of the APC strategy in reducing positioning errors and improving feeding accuracy in DBSFM machining processes.

Designing a Dual-Feed Circular Polarization Antenna

This paper describes a novel dual-feed circularly polarized antenna, and the dual feeding mode is realized by grooving on the antenna radiator. The antenna utilizes air dielectric material to meet the requirements of low weight and cost. Test results demonstrate that the antenna exhibits capacitive loading between the metal antenna patch and the ground floor, allowing for adjustment of the working frequency of the dual-feed circularly polarized microstrip antenna. Specifically, the original center frequency of 2.264 GHz was reduced to 1.582 GHz, facilitating antenna miniaturization and broad bandwidth. With a return loss (S11) below -10 dB, a bandwidth of 72 MHz (1.552-1.624 GHz) was obtained. Additionally, the dual-feed microstrip antenna incorporates a 90° bridge, resulting in circular polarization gains of 2.26 dBi at 1.561 GHz and 2.45 dBi at 1.575 GHz. Overall, the antenna design offers a large working bandwidth and excellent circular polarization characteristics, making it suitable for a wide range of applications in satellite navigation and positioning terminals.

Research on the Dynamic Characteristics of a Dual Linear-Motor Differential-Drive Micro-Feed Servo System

(1) Objectives: This article presents a dual linear-motor differential drive micro-feed servo system, mainly through the optimization design of the transmission mechanism. Owing to the differential synthesis of the micro feed from the upper and under linear motors, the impact of friction nonlinearity during the ultra-low velocity micro feed is avoided, endowing the system with a lower stable feed speed to achieve precise micro-feed control. (2) Methods: Transmission components of the dual linear-motor differential-drive system are analyzed using the lumped parameter method, and a dynamic model of electromechanical coupling is created, which takes into account nonlinear friction. The motion relationship of the dual linear-motor differential-drive servo feed system is characterized using a transfer function block diagram. (3) Discussions: Through simulation, the differences in response between the linear-motor single-drive system and the dual linear-motor differential-drive system are examined under fixed or variable feeding velocities as well as the impact of varying velocity combinations of dual linear motors on the output speed of the differential drive system. (4) Results: Nonlinear friction factors exert an impact on the feed velocity of both linear-motor single-drive and dual linear-motor differential-drive systems during low-velocity micro feed. However, regardless of the constant or variable speed conditions, the dual linear-motor differential-drive servo system significantly outperforms the linear-motor single-drive system regarding low-velocity micro feed. Our simulation results are basically consistent with engineering practice, thus validating the rationality of the created system models, which paves the ground for the micro-feed control algorithms.

C-Slot Circular Polarized Antenna for Hybrid Energy Harvesting and Wireless Sensing

This paper presents a new hybrid energy harvesting on electromagnetic solar for wireless energy harvesting of ambient from sensors of low-power devices. The axial ratio (AR) requirements produce Left-Hand Circular Polarization (LHCP) and Right-Hand Circular Polarization (RHCP) and simultaneously produce a 90-degree phase difference during energy harvesting, adopting a new design in designing a dual-feed broadband circular polarized (CP) antenna. To get the frequency band 2.3–2.4 GHz, we propose a C-Slot antenna with a circular patch dual feed. To estimate the diversity of the phase and magnitude output of the feed configuration under AR value, we used a 50 Ohm feed network output of the characteristic analysis for a dual feed CP antenna. An Axial ratio frequency range of less than 3 dB is achieved using polarization analysis with different branch channel couplers. To produce a DC output voltage, a high-frequency rectifier circuit embedded with a thin-film solar cell on the antenna is then connected to two T-junction power divider rectifiers, resulting in a high-efficiency design. A complete system-level analysis will include multiple signal classification methods of powered ambient RF energy using a wireless energy harvesting array that proposes a compact structure and demonstrates optimal configuration. Reliable operation in typical indoor environments indicates a self-contained sensor Node. Therefore, it has significant implications for powering small electronics and wireless sensor applications independently of the IoT Network or real implementation telecommunications industry.

Design of a Reconfigurable Band-notched Wideband Antenna using EBG Structures

A compact WLAN band-notched reconfigurable wideband antenna using two mushroom-like electromagnetic band-gap (EBG) structures is proposed in this paper. It is designed based on a dual wideband microstrip feed patch antenna with operating frequency bands of 2.2-3.7 GHz and 4.8-6 GHz. One of the EBG cells is positioned alongside the feed line, while the other EBG cell is laid on the back of the substrate. The patch or ground of the two EBG units are fed with a stronger current through a ground slot and a parasitic stub respectively, and the connections between the EBG structures and the antenna are controlled by loading a PIN diode with two 56 pF DC blocking capacitors. The advantage of this proposed design is that the antenna and the EBG unit can be designed independently. The proposed antenna has an overall size of 35×46×1.6 mm3. When testing the S11 of the antenna, the influence of the bias circuit on the antenna is also considered. The measured results show that the proposed antenna can generate two notched bands of 2.3-2.49 GHz and 5.11-5.51 GHz of WLAN, and the realized gain in the notch bands can be reduced to -2.65 dBi and -4.55 dBi, respectively, demonstrating its anti-interference characteristics, and can be applied in band notch broadband communication systems or anti-interference communication equipments such as unmanned aerial vehicles and radars.

Isolation enhancement of distinct element dual polarized compact MIMO antenna for 5G/WLAN application

AbstractA novel‐shaped dual‐polarized low‐profile multiple‐input multiple‐output (MIMO) antenna with high isolation is proposed for 5G/WLAN application. An 8‐element MIMO antenna design comprises two unique planar radiators (chamfer, circular). Each radiator has dual feed and dual polarization characteristics. The prototype is fabricated with an FR‐4 dielectric substrate. A decoupling structure maintains desirable isolation for self‐isolated elements (−12 dB) using substrate integrated waveguide stubs between inter‐ports and high isolation among the adjacent radiating elements (−15 dB). The simulation was performed by using CST microwave studio. The simulated results of the proposed MIMO antenna are compared with the measurement results. Furthermore, ECC and DG are investigated.

Dual feed progressive cavity pump extrusion system for functionally graded direct ink write 3D printing

Material extrusion Additive Manufacturing (AM), is one of the most widely practiced methods of AM. Fused Filament Fabrication (FFF) is what most associate with AM, as it is relatively inexpensive, and highly accessible, involving feeding plastic filament into a hot-end that melts and extrudes from a nozzle as the toolhead moves along the toolpath. Direct Ink Write (DIW) 3D printing falls into this same category of AM, however is primarily practiced in laboratory settings to construct novel parts from flowable feedstock materials. DIW printers are relatively expensive and often depend on custom software to print a part, limiting user-specificity. There have been recent advancements in multi-material and functionally graded DIW, but the systems are highly custom and the methods used to achieve multi-material prints are openly available to the public. The following article outlines the construction and operation method of a DIW system that is capable of printing that can produce compositionally-graded components using a dual feed progressive cavity pump extruder equipped with a dynamic mixer. The extruder and its capabilities to vary material composition while printing are demonstrated using a Prusa i3 MK3S+ desktop fused filament fabrication printer as the gantry system. This provides users ease of operation, and the capability of further tailoring to specific needs.

A single feed circularly polarized dual band microstrip monopole antenna for wireless applications

AbstractThe paper proposes a circularly polarized dual band single feed microstrip monopole antenna. The proposed antenna consists of a radiating patch, a shrink ground plane, and a 50 Ω microstrip transmission line feed. The radiating patch is a combination of three modified metallic strips, a modified rectangular strip and a semicircular strip. The ground plane consists of two modified open ended slots. The substrate area of the antenna is only 40 mm × 42 mm × 1.6 mm. The antenna has been designed by HFSS simulation software and after getting simulated results the antenna has been fabricated to verify its results. The antenna provides measured bandwidths (−10 dB impedance bandwidth) of 600 MHz (2.2–2.8 GHz) in the lower band and 2.1 GHz (7.5–9.6 GHz) in the higher band. The measured results show its 3 dB axial ratio bandwidth of 120 MHz (2.2–2.32 GHz) for lower band and 1.4 GHz (7.2–8.6) GHz for the upper band. The high measured peak gain of 8 dBi has been obtained from the proposed antenna. The lower band is useful for WiMAX application and upper band is useful for C band application. The desired radiation patterns (RHCP and LHCP) have been obtained from the proposed antenna.

Bandwidth Enhancement of Microstrip Antenna Using Dual Feed Line with Array 2x1 element for Radar Applications

Radar communication systems are needed to predict weather and other military needs. One of the important parameters required for a radar communication system is an antenna with high performance and broad bandwidth that can improve the resolution. The research proposes a single patch microstrip antenna that is rectangular and has a 8 GHz resonance frequency for radar applications that have high bandwidth and performance. The antenna was developed with two dual feed lines connected to the peradiation element with the 2x1 element array technique aimed at increasing the bandwidth of the frequency. The antenna is designed using a FR-4 substrate with a tangent loss of 0.0265, a dielectric constant ( |r) = 4.3, a substrat thickness (h) = 1.6 mm. The dimensions of the rectangular single patch microstrip antenna substrata are 20x20 mm2 and 35x35 mm2 for the dual feed line antenna design. Simulation results from the antenna development showed a 159.62% increase in bandwidth compared to the original antenna design. The reflection coefficient also increased from the original design antenna, which was -16.36 dB, to -25.64 dB or an increase of 56.72%. This antenna is very suitable and recommended to be applied as a receiver antenna on radar communications systems

Strategies to combat heat stress in poultry production-A review.

The effects of heat stress (HS) caused by high temperatures continue to be a global concern in poultry production. Poultry birds are homoeothermic, however, modern-day chickens are highly susceptible to HSdue to their inefficiency in dissipating heat from their body due to the lack of sweat glands. During HS, the heat load is higher than the chickens'ability to regulate it. This can disturb normal physiological functioning, affect metabolismand cause behavioural changes, respiratory alkalosis and immune dysregulation in birds. These adverse effects cause gut dysbiosis and, therefore, reduce nutrient absorption and energy metabolism. Thisconsequentlyreduces production performances and causes economic losses. Several strategies have been explored to combat the effects of HS. These include environmentally controlled houses, provision of clean cold water, low stocking density, supplementation of appropriate feed additives, dual and restricted feeding regimes, early heat conditioningand genetic selection of poultry lines to produce heat-resistant birds. Despite all these efforts, HS still remains a challenge in the poultry sector. Therefore, there is a need to explore effective strategies to address this long-lasting problem. The most recent strategy to ameliorate HS in poultry is early perinatal programming using the in ovo technology. Such an approach seems particularly justified in broilers because chick embryo development (21 days) equals half of the chickens'posthatch lifespan (42 days). As such, this strategy is expected to be more efficient and cost-effective to mitigate the effects of HS on poultry and improve the performance and health of birds. Therefore, this review discusses the impact of HS on poultry, the advantages and limitations of the different strategies. Finally recommend a promising strategy that could be efficient in ameliorating the adverse effects of HS in poultry.

A Four Slot Dual Feed and Dual Band Reconfigurable Antenna for Fixed Satellite Service Applications

A dual feed and dual-band reconfigurable antenna is designed, analyzed, and prototyped in this work for fixed satellite service communication applications. The designed model occupies the compact dimension of 24X21X1.2 mm on FR4 substrate and provides an input impedance of 50 ohms at both ports. The proposed model offers additional circular polarization characteristics at both the resonating bands. The PIN diode-based switching conditions, and the frequency reconfigurability analysis in both simulation and measurement are almost match. The combination of dual-band resonance, frequency reconfigurable nature, and compact dimension makes this model an attractive candidate in the specified field with considerable gain (8.5 dB) and efficiency (80%).

Design and characterization of a circularly polarized microstrip-line-fed slot array antenna for S-band applications

A 2×2 slot array antenna fed by microstrip line for circular polarization operated in the S band frequency range is designed in this paper. Single cross slot with single port feed as well as dual port feed is taken into consideration for realizing circular polarization and combining these two processes, the slot array is designed with single feed for circular polarization. The antennas are designed on a Teflon glass fiber substrate of thickness 0.8 mm. The slot array dimension is 120×142×1.636 mm<sup>3</sup>. Smith chart of single cross slot antenna with single feed as well as dual feed has a dip at 2.69 and 2.53 GHz respectively indicate the capability of realizing circular polarization in the S band frequency range. The return loss of the slot array antenna is -58 dB shows good input impedance matching of the antenna. A dip in the smith chart of the slot array shows circular polarization near 2.4 GHz ensuring wireless applications as well. Axial ratio is found to be less than 1 dB in the resonance frequency. The impedance bandwidth percentage of the slot array antenna is 12.24%. The simulation is done by using keysight advanced design system (ADS) software.

Dual modality feeders: a group of human milk feeders with unique practices and needs.

Dual modality feeding (DMF) - feeding human milk interchangeably from the breast and from a bottle - comes with unique practical, emotional and relational challenges, as well as support needs. Yet, there is little research that explores the experiences of individuals who use DMF in the Canadian context. The aim of this study is to explore the practices, challenges, reasons and enablers of DMF. Repeat, semi-structured one-on-one interviews were conducted at 8 weeks and 22 weeks postpartum. Interview transcripts were thematically analysed using a critical feminist lens. Nova Scotia, Canada. Ten DMF mothers. DMF practices were influenced by a mix of social and material circumstances, including breast-feeding challenges, the involvement of support persons, finances and access to lactation support. Individuals who predominantly fed at the breast expressed milk strategically to mitigate transitory breast-feeding challenges, for convenience under specific circumstances, and to share feeding responsibilities with other caregivers for personal and practical reasons. Individuals who mainly bottle-fed did so due to long-term breast-feeding challenges or a need to return to employment. Enablers of successful DMF were consistent between the two groups and included practical, personal and relational aspects. DMF is a unique practice compared to feeding human milk solely from the breast or bottle. Despite the potential growing prevalence of DMF, it is currently understudied and inadequately addressed in existing support programmes in Nova Scotia. Tailored programming and public messaging are needed to support DMF families.

Parametric optimisation and performance evaluation of gasifier-CI engine on dual fuel and dual feed material gasification

Gasification-based energy derived is one of the appealing resources for producing heat and power generation. The objective of this paper is to conduct an experimental study on downdraft air co-gasification of Madhuca longifolia wood and Indian low-grade coal (50:50 wt %) to generate producer gas and its application in dual-fuelled mode CI engine. Besides, the optimisation using the response surface methodology (RSM) has been applied to Gasifier-Engine to determine the best engine performance and emission response by optimising the input variables, i.e. gasifier equivalence ratio, engine compression ratio, and engine load. The RSM-based analysis predicted that optimum input operating parameters could be attained for co-gasification for Equivalence ratio (ER), compression ratio (CR), and engine load (EL) at 0.43, 16, and 100%, respectively. Based on optimal input variables, the performance response values of the gasifier-engine are 29.52% Brake thermal efficiency (BTE), 3.30 kW Brake power (BP), 0.3851 kg/kWh Brake specific fuel consumption (BSFC), 0.0186 vol% CO, 0.958 ppm UHC, 0.9768 vol % CO2, and 109.415 ppm NOx. The results show that the projected regression model has a high accuracy of R2 > 90% and a high correlation coefficient of 0.8927.

Improvised dual lumen nasojejunal feeding tube with gastric decompression.

Video 1Improvisation of the nasojejunal tube for gastric outlet obstruction.

Feasibility of double wire arc additive technology for production of Fe3Al net shaped parts: Wear and high temperature properties characterization

In this work, double wire arc addictive manufacturing (WAAM) of Fe3Al parts was implemented and high-temperature properties of produced structures were studied. In-situ fabrication of several wall-shaped intermetallic structures was performed using a dual wire feeding system, designed for unsymmetrical transfer of Fe- and Al-based wires. Mechanical properties, such as strength and ductility, as well as phase composition and microstructure of produced material were studied. Enhanced ductility at room temperatures and superplastic behavior at high temperatures were revealed by tensile tests. Furthermore, anomaly in temperature dependance of ultimate tensile strength has been revealed and discussed. Wear properties analysis demonstrated higher friction coefficient with lower wear rate for Fe3Al than for stainless steel.

Dual-Stable-Isotope-Probed Raman microspectroscopy reveals the metabolic dynamic of Streptococcus mutans

Streptococcus mutans (S. mutans) is regarded as a cariogenic pathogen with the ability to metabolize sugars and form organic acids. However, its actual timely level of glucose consumption and cellular vitality in a polymicrobial culture system remains largely unknown. To tackle this challenge, we employed the S. mutans UA159 as a model and developed a dual-stable-isotope-probed Raman microspectroscopy method (Dual SIP-Raman) to simultaneously profile the general metabolic activity and glucose assimilative activity in situ. (i) Mono-SIP substrate feeding revealed that 0.5% 13C-glucose and 30% D2O were proper doses in the medium to obtain prominent and quantitative band shifts along with the 13C or D2O incorporation. In addition, the intensity of the 13C peak of phenylalanine (Phe) is proposed as a Raman-based biomarker for glucose utilization in a cell. (ii) The state of dual SIP substrate incorporation of 13C-glucose and D2O could be visualized by the corresponding spectral “red shifts” of Raman-scattered emissions; moreover, we also demonstrated that 13C/12C analysis was closely correlated with the C-D ratio. (iii) The application of the dual 13C-glucose and D2O feeding approach on a mock microbiota of S. mutans UA159 and C. albicans ATCC14053 revealed a stimulatory effect of fungus on both the glucose intake rate and general metabolic vitality of S. mutans UA159 (p < 0.05). Therefore, the 13C-glucose and D2O dual-feeding Raman Microspectroscopy approach is a valuable new tool for evaluating the glucose intake rate and general metabolic levels in situ, tracing the changing trend of the above metabolic activities, which is helpful to clarify the changes in the cariogenicity of oral microorganisms caused by the external environment at the single-cell level.

Design and research of feed switching system for 40m radio telescope

For a large-aperture radio telescope, the working frequency of the feed and receiver determines its working range and capability. Many telescopes are designed with relatively few feed sources. With the development of deep space explorations and astronomical technologies, the existing feed of the antenna cannot meet the needs of observation tasks. To further adapt to the needs of the lunar exploration project, deep space explorations, and other astronomical observations, the feed of the 40 m antenna was upgraded with multiple feeds and feed switching systems. Based on not changing the existing antenna structure, the original S/X dual band feed is removed, a new S/X dual band feed is installed, C band and Ku band feeds are added, and rapid electrical switching of three feeds was realized. This paper gives a detailed design scheme and an implementation scheme of the feed-switching system. After being upgraded, the performance indexes of the antenna meet requirements, and the 40m telescope has multi-band reception capability, which lays a foundation for making the best of the telescope and making more scientific research outputs.