Feeding Mechanism Research Articles

The rise of biting during the Cenozoic fueled reef fish body shape diversification

Diversity of feeding mechanisms is a hallmark of reef fishes, but the history of this variation is not fully understood. Here, we explore the emergence and proliferation of a biting mode of feeding, which enables fishes to feed on attached benthic prey. We find that feeding modes other than suction, including biting, ram biting, and an intermediate group that uses both biting and suction, were nearly absent among the lineages of teleost fishes inhabiting reefs prior to the end-Cretaceous mass extinction, but benthic biting has rapidly increased in frequency since then, accounting for about 40% of reef species today. Further, we measured the impact of feeding mode on body shape diversification in reef fishes. We fit a model of multivariate character evolution to a dataset comprising three-dimensional body shape of 1,530 species of teleost reef fishes across 111 families. Dedicated biters have accumulated over half of the body shape variation that suction feeders have in just 18% of the evolutionary time by evolving body shape ∼1.7 times faster than suction feeders. As a possible response to the ecological and functional diversity of attached prey, biters have dynamically evolved both into shapes that resemble suction feeders as well as novel body forms characterized by lateral compression and small jaws. The ascendance of species that use biting mechanisms to feed on attached prey reshaped modern reef fish assemblages and has been a major contributor to their ecological and phenotypic diversification.

A Novel Design and Development of a Strip-Fed Circularly Polarized Rectangular Dielectric Resonator Antenna for 5G NR Sub-6 GHz Band Applications.

In this article, a rectangular dielectric resonator antenna (RDRA) with circularly polarized (CP) response is presented for 5G NR (New Radio) Sub-6 GHz band applications. A uniquely shaped conformal metal feeding strip is proposed to excite the RDRA in higher-order mode for high gain utilization. By using the proposed feeding mechanism, the degenerate mode pair of the first higher-order, i.e., at 4.13 GHz and at 4.52 GHz is excited to achieve a circularly polarized response. A circular polarization over a bandwidth of ~10%, in conjunction with a wide impedance matching over a bandwidth of ~17%, were attained by the antenna. The CP antenna proposed offers a useful gain of ~6.2 dBic. The achieved CP bandwidth of the RDRA is good enough to cover the targeted 5G NR bands around 4.4–4.8 GHz, such as n79. The proposed antenna configuration is modelled and optimized using computer simulation technology (CST). A prototype was built to confirm (validate) the performance estimated through simulation. A good agreement was observed between simulated and measured results.

Long-Axis Rotation of Jaws of Bamboo Sharks (Chiloscyllium plagiosum) During Suction Feeding.

SynopsisLong-axis rotation (LAR) of the jaws may be an important component of vertebrate feeding mechanisms, as it has been hypothesized to occur during prey capture or food processing across diverse vertebrate groups including mammals, ray-finned fishes, and sharks and rays. LAR can affect tooth orientation as well as muscle fiber direction and therefore muscle power during feeding. However, to date only a handful of studies have demonstrated this LAR in vivo. Here, we use XROMM to document LAR of the upper and lower jaws in white-spotted bamboo sharks, Chiloscyllium plagiosum, during suction feeding. As the lower jaw begins to depress for suction expansion, both the upper jaw (palatoquadrate) and lower jaw (Meckel's cartilage) evert, such that their toothed surfaces move laterally, and then they invert with jaw closing. Eversion has been shown to tense the dental ligament and erect the teeth in some sharks, but it is not clear how this tooth erection would contribute to suction feeding in bamboo sharks. Two recent XROMM studies have shown LAR of the lower jaws during mastication in mammals and stingrays and our study extends LAR to suction feeding and confirms its presence in shark species. Examples of LAR of the jaws are becoming increasingly widespread across vertebrates with unfused mandibular symphyses. Unfused lower jaws are the plesiomorphic condition for most vertebrate lineages and therefore LAR may be a common component of jaw mechanics unless the mandibular symphysis is fused.

A Review on Novel Microstrip Patch Antenna Designs and Feeding Techniques

Mobile technology is rapidly advancing nowadays due to its high impact in our day-to-day lives. As a result, there is an increasing need to study the advancement of antenna systems, which are regarded as fundamental equipment for wireless connectivity. Compared to the traditional large size antennas, microstrip patch antennas are now widely used in different applications such as smart phones, military, smart wearable devices etc. due to its unique characteristics such as lighter weight, reconfigurable structure, foldability, ease of fabrication, multi-frequency operations, and compactness. This research study presents a review on various microstrip patch antenna designs and the different antenna feed mechanisms available for 5G applications.

Broadband Circularly Polarized Antennas with Compact Radiator Using Characteristic Mode Analysis

In this paper, a general design procedure of simple four steps for wideband circularly polarized (CP) antenna based on characteristic mode analysis (CMA) is proposed. CMA is performed to investigate the CP generation principle of the proposed radiator. Modal currents and their corresponding radiation patterns are studied for mode selection and feeding placement to achieve CP operation. Then, two feeding mechanisms are introduced to constitute two CP antenna prototypes, which are further analyzed and optimized by CMA. With the physical insight into radiation characteristics of the prototypes, two antennas employing coplanar waveguide (CPW) as feed are designed and optimized by full-wave simulation. To validate the design procedure, both antennas with the same dimension (35 × 40 × 1.6 mm 3 ) are fabricated and measured. The experimental results show that both of the antennas have good CP radiation performance with a peak gain of 4.0 dBic and 2.5 dBic and axial ratio bandwidth (ARBW) of 48.3% and 44%, respectively. In addition, the experimental results are in good agreement with the radiation information provided by CMA.

Mouthpart structure of the adult Bicaubittacus appendiculatus ( ) (Mecoptera: Bittacidae)

The structure and functional morphology of the mouthparts were investigated in adult hangingfly Bicaubittacus appendiculatus (Esben-Petersen, 1927) by scanning electron microscopy and histological serial sections. The mandibulate mouthparts consist of a labrum-epipharynx, paired mandibles and maxillae, and unpaired labium and hypopharynx. The labrum is elongated and tapered toward the apex. The epipharynx is furnished with numerous sensilla. The mandibles are sword-shaped, with an outer sharp tooth curved mesad and an inner blunt corner. The basal region of each mandible processes a conical projection. The maxillae are well-developed, each consisting of a sclerotized cardo, an elongated stipes, which bears an inner lacinia, an outer galea, and laterally a five-segmented maxillary palp. The labium is formed by a postmentum, a prementum and a pair of two-segmented labial palps. The hypopharynx is concave inward on the anterior side, with numerous microtrichia on the posterior surface. Seven types of sensilla were found on the mouthparts: sensilla basiconica on the epipharynx, and maxillary and labial palps; sensilla chaetica on the epipharynx; sensilla palmata, sensilla placoidea and sensilla trichodea on the epipharynx and maxillary palp; sensilla campaniformia and hair plates on the basal joints of palps. The sensillar function and the feeding mechanism of mouthparts in bittacids are briefly discussed.

Regulation of Homeostasis by Neuropeptide Y: Involvement in Food Intake.

Obesity leads to several metabolic disorders and, unfortunately, current pharmacological treatments for obesity are not very effective. In feeding mechanisms, the hypothalamus and some neuropeptides play an important role. Many data show that neuropeptide Y (NPY) is involved in these mechanisms. The aim of this review is to update the physiological actions mediated by the orexigenic peptide NPY, via its receptors, in the control of food intake and to review its involvement in food intake disorders. The relationships between NPY and other substances involved in food intake mechanisms, hypothalamic and extra-hypothalamic pathways involved in feeding and the potential pharmacological strategies to treat obesity will be discussed. Some research lines, focused on NPY, to be developed in the future are suggested. Neuropeptide systems are associated with redundancy and then therapies directed against a single target are generally ineffective. For this reason, other targets for the treatment of obesity are mentioned. It seems that combination therapies are the best option for successful anti-obesity treatments: new and more specific NPY receptor antagonists must be tested as anti-obesity drugs alone and in combination therapies.

Antenna-on-Display Concept on an Extremely Thin Substrate for Sub-6 GHz Wireless Applications

This communication presents a concept of a sub-6 GHz antenna-on-display (AoD) that can eventually be integrated into the transparent area of a display panel of various wireless devices for the first time in the literature. The transparency of the proposed microwave AoD is realized using metal mesh conductive film and features optical transparency, which is compatible with high-resolution liquid crystal display (LCD)/organic light-emitting diode (OLED) display panel requirements. To maximize the radiation efficiency despite the extremely thin substrate ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.0048\lambda _{0}$ </tex-math></inline-formula> ), a traveling-wave antenna topology is inspired and further modified to incorporate the inherent structural limitations of modern-day high-resolution display panels. Eventually designed to operate in a leaky-wave mode, a novella dedicated feeding mechanism is introduced to minimize undesired coupling between the antenna structure and the display panel. The composite right-/left-handed (CRLH) unit cell employs a single shunt inductor topology to maximize the radiation efficiency. The measured 6 dB impedance bandwidth of the proposed microwave AoD is from 2.36 to 6.17 GHz, which is consistent with the fast wave region of the proposed unit cell. The measured realized gain of the microwave AoD consisting of 13 unit cells is 2.68 dBi at 5.5 GHz with a radiation efficiency of 62.5%. This is the first demonstration to ascertain that an AoD topology can be applicable at microwave applications while reducing the antenna-to-ground distance by approximately a factor of 20 compared to previous studies.

Design and experiment of a control system for sweet potato seedling feeding and planting device based on pretreatment seedling belt

Although existing sweet potato transplanters require automatic seedling feeding instead of manual seedling feeding, this causes seedling leakage and low efficiency. In this work, a control system for automatic seedling feeding of sweet potatoes was designed based on a pretreatment seedling belt. The system uses STM32 as the main controller and obtains the running speed of the machine through the encoder. The speed of the planting motor can be adjusted in real-time according to the running speed to keep the planting distance stable. The speed control model and linkage control strategy of seedling feeding and planting motors are investigated to keep the system feeding frequency and planting frequency consistent under running speed change. In order to verify the performance of this control system, a test bench was built, and some experiments were conducted. The test results show that the average error of seedling feeding motor speed is 4.04%, and that of planting motor speed is 3.28%. At medium and low operating speed levels, the stability of the seedling feeding mechanism is good, and the relative errors of automatic seedling feeding operation are 7.8% and 5.1%, respectively. The variation coefficients of plant spacing were 9.34% and 7.42%, respectively, indicating that the system could meet the seedling feeding and planting device control requirements based on the seedling belt and realize continuous automatic seedling feeding in the process of sweet potato seedling transplanting.

THE STUDY OF THE PECULIARITIES OF THE MECHANIZED ELECTRIC ARC CLADDING WITH PERIODIC VARIATION OF THE MODES OF THE PROCESS

Purpose. Research of the influence of modulation of arc processes on characteristics of clad metal with revealing the dependences of chemical composition and geometrical dimensions of the clad metal on the modulation parameters, as well as the development of mathematical models of these dependences with the purpose of predicting the results of modulation to improve the quality of deposited layers.&#x0D; Methods of research. Well-known methods of surfacing metal research were used:&#x0D; spectral analysis of metal composition, metallographic analysis of the obtained samples of cross-sections of the cladding rolls. Special computerized programs were used to measure geometric dimensions of the roll. Methods of regression analysis were used in order to obtain generalized mathematical models of dependencies of chemical elements and geometrical dimensions on modulation parameters.&#x0D; Results. In the process of research with electric-arc cladding of electrode flux-cored self-shielded wire, generalized results of dependences of carbon, chromium and boron content, width, amplification and penetration of cross-sectional area on the frequency and modulation duty cycle of electric-arc process parameters were obtained. Method of mathematical description of modulation effect on chemical composition and shape of the weld bead was developed.&#x0D; Scientific novelty. It was suggested to carry out estimation of the results by applying mathematical models when carrying out the electric arc process with periodic change of power parameters of current surfacing due to controlling the electric drive of the electrode wire feeding mechanism and also with change of voltage when controlling the output voltage of the welding current source. &#x0D; Practical value. A set of studies concerning the effects of modulation of power parameters of the welding process using an original development of the modulator allows, based on relatively simple systems of automatic and mechanized equipmen makes it possible, to obtain a controlled process of influence on the characteristics of the fused metal with their improvement for the implementation in industrial production.

Ontogeny of the skull of the blind snakeAmerotyphlops brongersmianus(Serpentes: Typhlopidae) brings new insights on snake cranial evolution

AbstractBlind snakes represent the most basal group of extant snakes and include fossorial species with unusual skeletal traits. Despite their known phylogenetic position, little is known about their ontogeny and what it might reveal about the origin of their skull anatomy. Here we describe for the first time the ontogenetic transformations of the skull of a blind snake, the typhlopid Amerotyphlops brongersmianus, including embryos and postnatal individuals. Furthermore, we provide data on the size changes relative to skull growth of the main elements of the gnathic complex. We observed that the skull of this blind snake undergoes considerable morphological change during late ontogeny. Additionally, we detected delayed development of some traits (closure of the skull roof, opisthotic-exoccipital suture, ossification of the posterior trabeculae) simultaneously with clearly peramorphic traits (development of the crista circumfenestralis, growth of the pterygoid bar). Our analysis suggests that the unique skull anatomy of blind snakes displays plesiomorphic and highly autapomorphic features, as an outcome of heterochronic processes and miniaturization, and is shaped by functional constraints related to a highly specialized feeding mechanism under the selective pressures of a fossorial lifestyle.

RANCANG BANGUN DAN KARAKTERISASI FEEDING MECHANISM SILIKONE BERBASIS SYRINGE PUMP PADA 3D PRINTER

Additive Manufacturing as one of the methods used on a 3D Printer can be applied with silicone as its material by designing a feeding mechanism based on a syringe pump which considers its mass flow rate. The purpose of this experiment is to produce the design of a feeding mechanism and to know the correlation between stepper motor torque (Tsm) and CNC travel feed rate (VCNC) with mass flow rate. The geometry which will be reviewed is a line. Those parameters will be characterized by measuring the width of the line (x) on the desired nine measured points. The most stable mass flow rate on stepper motor torque is determined by the smallest difference between average line width, while the most stable mass flow rate on CNC travel feed rate is determined by the smallest deviation standard between each measured points. The characterization results show that the smallest stepper motor torque value has the smallest difference between the average line width, which is 1,92 mm; while the highest stepper motor torque value has the highest difference between average line width, which is 3,66 mm and the highest CNC travel feed rate has the smallest deviation standard, which is 0,91; while the smallest CNC travel feed rate has the highest deviation standard, which is 2,14. Both of the statements imply that a smaller amount of the stepper motor torque and a higher amount of CNC travel feed rate will induce a more stable mass flow rate, it also works the other way around.

Design and Test of an Automatic Husking and Peeling Machine for Fresh Lotus Seeds

There are regional differences, variety differences and maturity differences in fresh lotus seeds. The parameters of husking and peeling machine working parts need to be adjusted in real time according to the processing effect. In response to the problems with the machine on the market including complicated transmission, difficult interconnectedness and adjustment of various working parts, etc., an automatic husking and peeling machine for fresh lotus seeds with the husking module and peeling module as the core devices has been designed. On the basis of the kinematic analysis of fresh lotus seed circulation process, a grooved wheel feeding mechanism and an arc track have been designed to realize the feeding and circulation of fresh lotus seeds. Experimental research has been conducted on the influence of working parameters on the film removal effect and the interaction between working parameters using the response surface method. In addition, the correctness of the above analysis has been verified by husking and peeling experiments. According to the experiment results, processing qualification rate and damage rate processing efficiency of this machine can meet the use requirements of lotus farmers. This research can provide a theoretical basis for the structural design and parameter optimization of related equipment.

Comparative morphology of the compound rhamphotheca of tubenosed seabirds (order Procellariiformes)

Compound rhamphothecae are characteristically present in the order Procellariiformes, but other birds also show this feature: ostriches, tinamous, cormorants, pelicans, herons. In Procellariiformes the shape, size and features of the rhamphotheca are not related to feeding mechanisms and/or displays (as in most birds) but with their nasal gland excretions and highly developed olfactory organ. The compound rhamphothecae are composed by several plates: the dorsal culminicorn, naricorn forming the tubes, the laterals latericorn, and premaxillary nail (upper jaw); the ramicorn and the mandibular nail (lower jaw). A nasolabial groove is present between the culminicorn and the latericorn, and caudally to the premaxillary nail. The mentolabial groove is between the ramicorn and the mandibular nail. Diomedeidae present a pseudomental fold and groove in the ventral part of the mandibular nail, the fold varies in its caudal extension. The ramicorn in Procellariidae is divided longitudinally into ventral and dorsal ramicorn by a suture. This feature is not found in other Procellariiformes except in Phoebetria palpebrata (Diomedeidae). The development and fusion of the tubes in Procellariidae vary as: a single tube, a partially fused tube, or completely separated tubes. Its extension is variable, reaching its greatest length in Macronectes giganteus. In Diomedeidae the configuration of the incurrent and excurrent apertures within or outside the tubes vary, and they present the shortest tubes. The grooves in Procellariidae vary in their development: the nasolabial groove sometimes is well marked with sutures, the ramicorn groove is always a sulcus (except for Fulmarus glacialoides) and expands cranially and/or caudally forming a triangle-shape depending on the species. In Diomedeidae the culminolabial groove presents variation at the dorsal branch, it can be: well developed, less developed or brief. Oceanitidae and Hydrobatidae present less variation. Phylogenetically, beaks of Oceanitidae and Hydrobatidae are the most basal, whereas Diomedeidae beaks derived from Procellariidae.

Passive acoustics suggest two different feeding mechanisms in the Atlantic walrus (Odobenus rosmarus rosmarus)

Passive acoustics suggest two different feeding mechanisms in the Atlantic walrus (Odobenus rosmarus rosmarus)

Low-Profile Wideband Dual-Circularly Polarized Metasurface Antenna Based on Traveling-Wave Sequential Feeding Mechanism

A novel low-profile wideband dual-circularly polarized metasurface antenna based on a traveling-wave sequential feeding mechanism is proposed. It consists of 4 × 4 rectangle metasurface cells and is excited by a simple two-port traveling-wave feeding network, which includes four rotated Z-shaped slots etched on the ground and a ring feeding line, to provide stable sequential phases of 0°, 90°, 180°, 270° for realizing dual-circular polarizations. By changing the width of four Z-shaped slots, the equal amplitude of two orthogonal electric fields can be achieved and good right- and left-handed circular polarization (RHCP, LHCP) can be realized accordingly in a wideband. Moreover, a metasurface is utilized as a radiator to improve the impedance bandwidth (IMBW) as well as radiation performance. For demonstration, one prototype with an overall size of 0.88λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> × 0.88λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> × 0.06λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> centered at 5.3 GHz is fabricated and measured. The measured results show that the proposed low-profile antenna realizes a large 10-dB IMBW of 38.4% (4.33–6.39 GHz) and 46.6% (6.17–6.70 GHz), 3-dB axial-ratio bandwidth of 38.4% and 39.3%, respectively, for RHCP and LHCP states. In addition, the polarization isolation is over 12 dB in the entire band of interest.

Royal knifefish generate powerful suction feeding through large neurocranial elevation and high epaxial muscle power.

Suction feeding in ray-finned fishes involves powerful buccal cavity expansion to accelerate water and food into the mouth. Previous XROMM studies in largemouth bass (Micropterus salmoides), bluegill sunfish (Lepomis macrochirus) and channel catfish (Ictalurus punctatus) have shown that more than 90% of suction power in high performance strikes comes from the axial musculature. Thus, the shape of the axial muscles and skeleton may affect suction feeding mechanics. Royal knifefish (Chitala blanci) have an unusual postcranial morphology, with a ventrally flexed vertebral column and relatively large mass of epaxial muscle. Based on their body shape, we hypothesized that royal knifefish would generate high power strikes by utilizing large neurocranial elevation, vertebral column extension and epaxial shortening. As predicted, C. blanci generated high suction expansion power compared with the other three species studied to date (up to 160 W), which was achieved by increasing both the rate of volume change and the intraoral subambient pressure. The large epaxial muscle (25% of body mass) shortened at high velocities to produce large neurocranial elevation and vertebral extension (up to 41deg, combined), as well as high muscle mass-specific power (up to 800 W kg-1). For the highest power strikes, axial muscles generated 95% of the power, and 64% of the axial muscle mass consisted of the epaxial muscles. The epaxial-dominated suction expansion of royal knifefish supports our hypothesis that postcranial morphology may be a strong predictor of suction feeding biomechanics.

Design and Fabrication of Automatic Coe Feeding Machine

Abstract: Conventionally the feeding of the cattle is manual which is time consuming. In this project, an automatic cattle feeding system is introduced where food feeder follows the path through a predetermined distance and places the feed to the cattle by the side of the feed fence. The prototype is developed using Arduino circuit for the operation of feed mechanism with certain time space. The motors are interfaced to operate in either direction. A rail bogie is operated by a DC motor to feed the cattle at certain time space. This mechanism is basically controlled by pulling mechanism by winding the rope around the motor operated shaft.

Aluminium Assisted Nickel Alloying in Submerged Arc Welding of Carbon Steel: Application of Unconstrained Metal Powders

Nickel alloying of carbon steel is used to enhance steel strength and toughness. Nickel alloying of the weld metal via solid weld wire presents several difficulties as highlighted previously, such as work hardening of the solid weld wire in manufacturing and feeding through the SAW wire feeding mechanism, and expensive and time consuming manufacturing of multiple weld wire formulations. The application of nickel and aluminium powders in unconstrained format, meaning not as fluxed cored wire or as metal cored wire, is used to simplify weld metal alloying. Al powder is used to control the oxygen potential at the weld pool-molten flux interface. The results presented here show that the addition of Al powder to the weld metal enhances Ni yield to the weld metal, at 85%, compared to pre-alloyed powder Ni yields of 57–78% as applied in previous work. Carbon steel was alloyed to 6.9% Ni and 3.7% Al. Thermodynamic analysis is applied to elucidate the chemical interaction between Ni and Al, and its effects on Ni yield in the weld pool. Overall process productivity gains stem from weld metal alloying from unconstrained metal powders because the expensive and time consuming step of manufacturing alloyed wire and alloyed powder is eliminated.

Design and Simulation of Small-Scale Waste Separation and Sorting Equipment

Environmental pollution is currently a major concern globally owing to increase in the world population and advances in industrialization. An automatic waste separation and sorting equipment for small-scale waste sorting systems was constructed in this paper. A two-DoF (two-degree-of-freedom) parallel sorting mechanism as well as a belt waste separation and feeding mechanism were designed, and 3D models of the mechanism were established. Finite element analysis (FEA) was conducted for the sorting mechanism, and kinematic and dynamic analysis and numerical simulation were performed for the waste and sorting mechanism. The simulation results demonstrated that the spherical waste did not roll out of the platform after leaving the slideway. The waste was stabilized at the center of the platform within a short duration with movement of the collecting mechanism of the platform. The system was optimized to reduce waste separation and sorting time. Stability of the waste motion in the equipment as well as efficiency of the system were significantly improved after optimization. The results showed that the designed equipment can complete separation and sorting of waste materials at lower output power.