Feeding Mechanism Research Articles

Performance Evaluation of Power Operated Chaff Cutter for Selected Fodder Crops

The study was conducted to evaluate the performance of power operated chaff cutter for three types of fodder crops, viz., jowar, maize, and sorghum, under load and no-load conditions during kharif (July to October, 2022) at Farm Machinery Testing Centre (FMTC), University of Agricultural Sciences, Raichur, Karnataka (16.2051°N,77.3303°E). The hardness of the blade was recorded to be 54 HRC, and the rate of wear of blades on a mass basis and a dimensional basis was recorded as 0.013% - 0.026% and 0.028% - 0.047% per hour, respectively. The power consumption of the chaff cutter at no load was recorded as 0.42 kWh. Similarly, the quantity of cut fodder received was measured as 621 - 623 kg h-1 and 1710 - 1816 kg h-1 for dry and wet fodder, respectively. The maximum specific energy consumption was recorded as 1123.21 - 2396.0 kg kWh-1 in dry and wet fodder, respectively. The quality of cut ranged from 0.38 - 0.42 and 0.41 - 0.43 in dry and wet fodder, respectively. The performance index of chaff cutters was recorded as 471.37 and 1006.34 for dry and wet fodder, respectively. The maximum efficiency was recorded as 96.62 - 97.87% and 97.50 - 98.10% for dry and wet fodder, respectively. The power-operated chaff cutter was operated for a long-run test (23.00 h) for cutting jowar (dry), maize, and sugarcane crops in both wet and dry conditions was done. No breakdown in the cutter head, feeding mechanism, transmission systems, body of the chaff cutter was noticed.

Marine community trophic structure of Malpelo Island, Colombia from stable isotopes approach

Expanding knowledge of the trophodynamic of ecosystems improves the understanding of energy flow and interactions formed in food webs; therefore, structural knowledge of food webs helps to understand the ecosystem dynamics. This study describes the marine trophic structure of the largest marine protected area (MPA) of the Colombian Pacific in Malpelo Island, using δ13C and δ15N. A total of 293 (38 groups/families) samples were collected and analyzed, being mostly represented by teleosts, followed by crustaceans, elasmobranchs, zooplankton, seabirds, and others functional groups. The marine isospace was between −21.5‰ and − 10.0‰ for δ13C and between 4.6‰ to 16.9‰ in δ15N. The Malpelo Island marine ecosystem showed a food web composed of five trophic levels (TLs): TL-I (primary producers), TL-II (herbivores), TL-III (primary carnivores), TL-IV (secondary carnivores), and TL-V (tertiary carnivores), along with three intermediate TLs (TLs II-III, III-IV, and IV-V). The isotopic diversity index showed global low values of uniqueness (IUni) (0–0.349), intermediate values of IRicGlobal, and IDisGlobal (0.350–0.640), and high values of IDivGlobal, and IEveGlobal (0.650–1). TLs reflected high trophic interaction indices as a result of multifunctionality (12 feeding mechanisms) and possible ontogenetic changes of organisms in this ecosystem. This study includes the first insights into the marine trophic structure of the Malpelo Island and indicate some functional aspects of the entities that inhabit this ecosystem. This study fill information gaps for the MPA and constitute an important tool to improve the elaboration of management and conservation measures based on the knowledge of the ecosystem function.

Deploy the proboscis!: Functional morphology and kinematics of a novel form of extreme jaw protrusion in the hingemouth, Phractolaemus ansorgii (Gonorynchiformes).

Premaxillary protrusion and the performance advantages it confers are implicated in the success of diverse lineages of teleost fishes, such as Cypriniformes and Acanthomorpha. Although premaxillary protrusion has evolved independently at least five times within bony fishes, much of the functional work investigating this kinesis relates to mechanisms found only in these two clades. Few studies have characterized feeding mechanisms in less-diverse premaxilla-protruding lineages and fewer yet have investigated the distinctive anatomy underlying jaw kinesis in these lineages. Here, we integrated dissection, clearing and staining, histology, micro-CT, and high-speed videography to investigate an isolated and independent origin of jaw protrusion in the hingemouth, Phractolaemus ansorgii, which employs a complex arrangement of bones, musculature, and connective tissues to feed on benthic detritus via a deployable proboscis. Our goals were to provide an integrative account of the underlying architecture of P. ansorgii's feeding apparatus and to assess the functional consequences of this drastic deviation from the more typical teleost condition. Phractolaemus ansorgii's cranial anatomy is distinct from all other fishes in that its adducted lower jaw is caudally oriented, and it possesses a mouth at the terminal end of an elongated, tube-like proboscis that is unique in its lack of skeletal support from the oral jaws. Instead, its mouth is supported primarily by hyaline-cell cartilage and other rigid connective tissues, and features highly flexible lips that are covered in rows of keratinous unculi. Concomitant changes to the adductor musculature likely allow for the flexibility to protrude the mouth dorsally and ventrally as observed during different feeding behaviors, while the intrinsic compliance of the lips allows for more effective scraping of irregular surfaces. From our feeding videos, we find that P. ansorgii is capable of modulating the distance of protrusion, with maximum anterior protrusion exceeding 30% of head length. This represents a previously undescribed example of extreme jaw protrusion on par with many acanthomorph species. Protrusion is much slower in P. ansorgii-reaching an average speed of 2.74 cm/s-compared to acanthomorphs feeding on elusive prey or even benthivorous cypriniforms. However, this reorganization of cranial anatomy may reflect a greater need for dexterity to forage more precisely in multiple directions and on a wide variety of surface textures. Although this highly modified mechanism may have limited versatility over evolutionary timescales, it has persisted in solitude within Gonorynchiformes, representing a novel functional solution for benthic feeding in tropical West African rivers.

Descriptive anatomy and three-dimensional reconstruction of the skull of the tetrapod Eoherpeton watsoni Panchen, 1975 from the Carboniferous of Scotland

ABSTRACT The early tetrapod Eoherpeton watsoni is known from the mid- to late Carboniferous (late Viséan to Namurian, approximately 346–313 Ma) of Scotland. The holotype is made up of a nearly complete but crushed skull with postcranial fragments. The skull anatomy of Eoherpeton was first described over 40 years ago; however, many details are obscured due to deformation of the specimen, including internal bone surfaces, the palatal bones and dentition, and suture morphology. Most phylogenetic analyses place Eoherpeton as an embolomere/reptilomorph on the lineage leading to amniotes, making it a key taxon for understanding anatomical changes during the fish-tetrapod transition. In this paper, we scanned the holotype using micro-computed tomography and digitally prepared the specimen. Based on these data, we present a revised description of the skull, including sutural morphology, that supplements and amends previous descriptions. New anatomical findings include the presence of a previously unknown tooth-bearing vomer, additional information on the shape of the basipterygoid processes and jaw joint, the ability to visualise the full extent of the pterygoid, and confirmation of the arrangement of the coronoid series. We also note the size of the pterygoid flange, which is larger than previously described for Eoherpeton. The pterygoid flange is widely considered to be characteristic of amniotes and serves as the origin of the medial pterygoideus muscle. The differentiation of the adductor muscles and appearance of medial pterygoideus are thought to have permitted a static pressure bite in amniotes, potentially resulting in greater bite forces and increased dietary range. Thus, the presence and extent of the pterygoid flange in Eoherpeton suggests this feature (and associated changes in feeding mechanism) may have evolved earlier than previously thought. Finally, the skull was digitally repaired and retrodeformed to create a new, hypothetical three-dimensional reconstruction of the skull of Eoherpeton.

A review of the role played by cilia in medusozoan feeding mechanics.

Cilia are widely present in metazoans and have various sensory and motor functions, including collection of particles through feeding currents in suspensivorous animals. Suspended particles occur at low densities and are too small to be captured individually, and therefore must be concentrated. Animals that feed on these particles have developed different mechanisms to encounter and capture their food. These mechanisms occur in three phases: (i) encounter; (ii) capture; and (iii) particle handling, which occurs by means of a cilia-generated current or the movement of capturing structures (e.g. tentacles) that transport the particle to the mouth. Cilia may be involved in any of these phases. Some cnidarians, as do other suspensivorous animals, utilise cilia in their feeding mechanisms. However, few studies have considered ciliary flow when examining the biomechanics of cnidarian feeding. Anthozoans (sessile cnidarians) are known to possess flow-promoting cilia, but these are absent in medusae. The traditional view is that jellyfish capture prey only by means of nematocysts (stinging structures) and mucus, and do not possess cilia that collect suspended particles. Herein, we first provide an overview of suspension feeding in invertebrates, and then critically analyse the presence, distribution, and function of cilia in the Cnidaria (mainly Medusozoa), with a focus on particle collection (suspension feeding). We analyse the different mechanisms of suspension feeding and sort them according to our proposed classification framework. We present a scheme for the phases of pelagic jellyfish suspension feeding based on this classification. There is evidence that cilia create currents but act only in phases 1 and 3 of suspension feeding in medusozoans. Research suggests that some scyphomedusae must exploit other nutritional sources besides prey captured by nematocysts and mucus, since the resources provided by this diet alone are insufficient to meet their energy requirements. Therefore, smaller particles and prey may be captured through other phase-2 mechanisms that could involve ciliary currents. We hypothesise that medusae, besides capturing prey by nematocysts (present in the tentacles and oral arms), also capture small particles with their cilia, therefore expanding their trophic niche and suggesting reinterpretation of the trophic role of medusoid cnidarians as exclusively plankton predators. We suggest further study of particle collection by ciliary action and its influence on the biomechanics of jellyfishes, to expand our understanding of the ecology of this group.

Multilayer circular substrate-integrated waveguide cavity band-pass filters with ultrawide stopband characteristics

AbstractThis paper presents a methodology to design band-pass filters having ultrawide stopband characteristics using multilayer circular substrate-integrated waveguide (SIW) cavities. The orthogonal microstrip feedlines are used as input and output ports that are present at the top and bottom layers, while the middle layers are used to couple the SIW cavities. Higher-order spurious modes of the circular SIW cavity are suppressed by using orthogonal feeding mechanism and properly adjusting the arc-shaped slots between the cavities. To validate the present approach, two filters (second- and fourth-order) have been designed and fabricated and their characteristics are measured. The second-order filter exhibits a stopband rejection below 25 dB up to nearly 5.07f0, while the fourth-order filter has a stopband characteristic of nearly 5.05f0 with 20 dB rejection. The filters allow only TM010 mode propagation and attenuate the higher-order spurious modes of the cavity.

Comparative histological and ultrastructural features of the tongue of the mallard domestic duck, Anas platyrhynchos f. domestica, Anatidae (Linnaeus, 1758) in different two age stages (post-hatching [P2] and adult female) captured from Egypt.

The domestic duck is classified as a specialist filter-feeder bird living in the water. These birds also use grazing and pecking as terrestrial feeding methods. The tongues of domestic ducks, similar to those of other Anseriformes, exhibit numerous types and shapes of mechanical papillae that serve a number of purposes when collecting food. The current study attempts to describe the morphological characteristics of the tongue as well as the mechanical papillae's development. In addition, the study aims to determine whether the papillae observed post-hatching (P2) exhibit similar morphology to those found in adult female avian species, as well as to investigate the readiness of the tongue to fulfill its feeding function following hatching. The comprehensive examination of lingual mucosa is examined about the structural modifications necessary for this variety of feeding activities. In this study, the tongues of nine young (P2) and adult female were used. The tongue had three distinct parts: the apex, which had a lingual nail on its ventral surface; the body, which exhibits numerous small and large conical papillae on its lateral sides and a lingual prominence in the caudal region; and the root, which is covered with numerous conical papillae of varying sizes. Conical, filiform, and hair-like mechanical papillae, the three types of food filtration apparatus, are present in both stages. The intraoral transfer involves several structures, including the median groove, lingual combs, and the rostral border of the lingual prominence. The rostral border of the lingual prominence is characterized by distinct rows of conical papillae. The histological analysis demonstrated the presence of both keratinized and nonkeratinized epithelium on different tongue regions. The lingual salivary glands in the rostral and caudal lingual salivary glands exhibit a pronounced periodic acid-Schiff-positive reaction. Additionally, the yellow adipose tissue and sensory receptors, namely the Grandry and Herbst corpuscles, which collectively form the bill-tongue organ that monitors the movement of food. These results conclude the presence of microstructural species-specific alterations in specific tongue areas of domestic ducks' lingual mucosa. These modifications are formed by the filtering mechanism and terrestrial feeding mechanisms, such as grazing or pecking. Following hatching, the tongue of the domestic duck undergoes significant development, primarily in preparation for grazing activities. The anatomical and histological structure of the young (P2) tongue exhibited similarities to that of the adult female domestic duck while also displaying certain variations that could potentially be attributed to the bird's habitat and mode of feeding. RESEARCH HIGHLIGHTS: The results of this study concluded that the domestic duck exhibit a complex tongue structure characterized by the arrangement and morphology of its mechanical papillae, the presence of the lingual prominence with distinctive shape and the lingual comb. These features are believed to be adaptations that enable the duck to actively and efficiently filter food particles from water, serving as its primary feeding mechanism. Additionally, the tongue of domestic ducks is specifically adapted to facilitate various terrestrial activities, such as grazing and pecking. This adaptation is achieved through the presence of conical papillae and a lingual nail. These investigations facilitate our comprehension of both the anatomical and histological characteristics of the domestic duck tongue, as well as enhance our understanding of bird adaptations to various feeding mechanisms.

Multi-material additive manufacturing via fused deposition modeling 3D printing: A systematic review on the material feeding mechanism

The rapid advancements in fused deposition modeling (FDM) 3D printing methods have unlocked new opportunities in multi-material additive manufacturing (AM). This technique offers a viable solution for creating high-performance, multi-functional graded materials, parts, and tooling. Despite the extensive efforts invested in exploring the potential of the FDM-type multi-material additive approach, there is a noticeable lack of discussion specifically centered around the material feeding mechanism of this extrusion-based 3D printing method. This work provides a systematic review on the current studies related to the multi-material FDM 3D printing. It is found that the interlayer adhesion quality of different feedstock materials is a first and foremost feature in determining the strength of the entire print. To this end, we particularly focus on analyzing the feeding system of multiple materials and the strategy for material alternation. From our analytical evaluations, it is noticed that the single-nozzle/multi-feed and multi-nozzle/multi-feed FDM printers present unique pros. and cons., respectively. Inspired by multi-material applications of direct ink writing extrusion-based 3D printing, we also suggest to choose a suitable method based on the material rheology and thermal properties of the constituent materials. This can be a chance to gain further benefits from the multi-material AM.

CIQBCP-MIMO-DRA: CSRR inspired quad band circularly polarized MIMO-DRA for W-LAN, Wi-Max, Wi-Fi (6E) and X-band applications

Abstract This paper emphasizes on amalgamation of MIMO antenna with DRA structures; explicitly useful to wireless applications. The feeding mechanism is accomplished by the symmetrically positioned tapered Y-shape lines. The design also encompasses a CSRR geometry along with two metallic reflectors. The incorporation of CSRR introduces novel investigation into traditional designs, resulting in improved isolation performance of the MIMO design. In order to demonstrate the effectiveness of the mentioned antenna, we performed a simulation using ANSYS-HFSS. Subsequently, a physical model was developed and tested. It confirms four different resonating points as 2.56, 4.08, 5.76, and 9.12 GHz with isolations of 36, 47.3, 33.9, and 33 dB respectively. In addition, a few other important parameters relevant to MIMO have been considered and presented in the form of ECC, MEG, DG, CCL, and TARC which claim the dominancy of the stated antenna under the MIMO diversity scenario. In summary, we have presented a model that demonstrates a strong correlation between the simulated and measured outcomes.

Feeding and trophic interactions of plankton Crustaceans in the pelagic zone of the Azabachye Lake

Characteristics of feeding mechanisms, forage composition and methods of analysis of the diet of plankton crustacean are demonstrated based on reviewed and author’s data. Preferable forage species for the mass plankton crustaceans Cyclops scutifer and Daphnia galeata in the lake Azabachye were figured out using methods of population ecology. It is revealed, that reproduction of the cyclops and daphnia populations prospers due to Aulacoseira subarctica. In the periods of poor vegetation of the diatom the cyclops have been feeding on shell-less rotifers, and in particular years – on the diatoms of the genera Stephanodiscus. In the years of vigorous bloom of Bacillariophyta the daphnias filter small cells of diatom (S. minutulus) or blue-green (Gloeocapsa sp.) algae. In case of suggested similarity in the forage organisms between small numbered Eurytemora kurenkovi and abundant C. scutifer, there was no competition observed between the copepods. The main forage component for predator Leptodora kindti was juvenile D. galeata. It is concluded based on the analysis, that intense competition between plankton crustaceans does not raise in the Azabachye Lake.

The anatomy and feeding mechanism of the Japanese giant salamander (Andrias japonicus).

The fully aquatic Japanese giant salamander (Andrias japonicus) is a member of the Cryptobranchidae, and is currently distributed in western Japan, with other members of this group restricted to China and North America. Their feeding behaviour is characterized by a form of suction feeding that includes asymmetric movements of the jaw and hyobranchial apparatus. Previous studies on the North American species, Cryptobranchus alleganiensis, have suggested that this specialized jaw movement is produced by a flexible quadrate-articular joint combined with a loosely connected lower jaw symphysis including two small fibrocartilaginous pads. However, little is known about this feeding behaviour in the Asian species, nor have the three-dimensional asymmetric jaw movements been fully investigated in any member of Cryptobranchidae. In this study, we explore the asymmetric jaw movements in A. japonicus using three methods: (1) dissection of musculoskeletal structures; (2) filming of feeding behaviour to understand in which situations asymmetric feeding is used; (3) analysis of 3D movement of jaws and skull. In the third component, fresh (from frozen) specimens of A. japonicus were manipulated to replicate asymmetric and symmetric jaw movements, with the specimens CT scanned after each step to obtain the 3D morphology of the jaws at different positions. These positions were combined and their Euler angles from resting (closed) jaw position were calculated for asymmetric or symmetric jaw positions. Our filming revealed that asymmetric jaw movements are linked to the position of the prey in relation to the snout, with the jaw closest to the prey opening asymmetrically. Moreover, this action allows the salamander to simultaneously grasp prey in one side of the mouth while ejecting water on the other side, if the first suction attempt fails. The asymmetric jaw movements are performed mainly by rotation of the mandible about its long axis, with very limited lateral jaw movements. During asymmetric and symmetric jaw movements, the posterior ends of the maxilla and quadrate move slightly. The asymmetric jaw movements are permitted by a mobile quadrate-articular joint formed by wide, round cartilages, and by two small fibrocartilage pads within the jaw symphysis that act as cushions during jaw rotation. Some of these soft tissue structures leave traces on the jaws and skull, allowing feeding mode to be reconstructed in fossil taxa. Understanding cryptobranchid asymmetric jaw movement thus requires a comprehensive assessment of not only the symphysial morphology but also that of other cranial and hyobranchial elements.

Comparative transcriptomic analysis of salivary glands between the zoophytophagous Cyrtorhinus lividipennis and the phytozoophagous Apolygus lucorum

BackgroundSaliva plays a crucial role in shaping the feeding behavior of insects, involving processes such as food digestion and the regulation of interactions between insects and their hosts. Cyrtorhinus lividipennis serves as a predominant natural enemy of rice pests, while Apolygus lucorum, exhibiting phytozoophagous feeding behavior, is a destructive agricultural pest. In this study, a comparative transcriptome analysis, incorporating the published genomes of C.lividipennis and A.lucorum, was conducted to reveal the role of salivary secretion in host adaptation.ResultsIn contrast to A.lucorum, C.lividipennis is a zoophytophagous insect. A de novo genome analysis of C.lividipennis yielded 19,706 unigenes, including 16,217 annotated ones. On the other hand, A.lucorum had altogether 20,111 annotated genes, as obtained from the published official gene set (20,353 unigenes). Functional analysis of the top 1,000 salivary gland (SG)-abundant genes in both insects revealed that the SG was a dynamically active tissue engaged in protein synthesis and secretion. Predictions of other tissues and signal peptides were compared. As a result, 94 and 157 salivary proteins were identified in C.lividipennis and A.lucorum, respectively, and were categorized into 68 and 81 orthogroups. Among them, 26 orthogroups were shared, potentially playing common roles in digestion and detoxification, including several venom serine proteases. Furthermore, 42 and 55 orthogroups were exclusive in C.lividipennis and A.lucorum, respectively, which were exemplified by a hyaluronidase in C.lividipennis that was associated with predation, while polygalacturonases in A.lucorum were involved in mesophyll-feeding patterns.ConclusionsFindings in this study provide a comprehensive insight into saliva secretions in C.lividipennis and A.lucorum via a transcriptome approach, reflecting the intricate connections between saliva secretions and feeding behaviors. It is found that conserved salivary secretions are involved in shaping the overlapping feeding patterns, while a plethora of unique salivary secretions may drive the evolution of specific feeding behaviors crucial for their survival. These results enhance our understanding of the feeding mechanisms in different insects from the perspective of saliva and contribute to future environmentally friendly pest control by utilizing predatory insects.

Role Reversals in a Tri-Trophic Prey–Predator Interaction System: A Model-Based Study Using Deterministic and Stochastic Approaches

It is frequently observed that adult members of prey species sometimes use their predation mechanism on juvenile members of predator species. Ecological literature describes this phenomenon as prey–predator role reversal dynamics.Numerous authors have observed and described the biological development behind this feeding behaviour. However, the dynamics of this role reversal have hardly been illustrated in the literature in a precise way. In this regard, we formulated an ecological model using the standard prey–predator interactions, allowing for a reverse feeding mechanism. The mathematical model consisted of a three-species food-web structure comprising the common prey, intermediate predator, and top predator. Note that a role-reversal mechanism was observed between the intermediate and top predators based on the scarcity of the prey population. However, we observed the most critical parameters had a significant effect on this reverse feeding behaviour. The bifurcation analysis is the primary criterion for this identification. The proposed deterministic model is then extended to its stochastic analogue by allowing for environmental influences on the tri-trophic food web structure. The conditional moment approach is applied to obtain the equilibrium distribution of populations and their conditional moments in the system. The stochastic setup analysis also supports the stability of this food chain structure, with some restricted conditions. Finally, to facilitate the interpretation of our mathematical results, we investigated it using numerical simulations.

The Microscopic Morphology of Mouthparts and Their Sensilla in the Mycophagous Ladybeetle Illeis chinensis (Coleoptera: Coccinellidae).

The morphological diversity of insect mouthparts is closely related to changes in food sources and diets. Research into the structures of insect mouthparts may help to establish a fundamental basis for a better understanding of insect feeding mechanisms. In this study, we examined the fine morphology of the mouthparts of Illeis chinensis using scanning electron microscopy. We paid particular attention to the types, quantities, and distribution of sensilla on the mouthparts. Our results showed that the basic components of the mouthparts of I. chinensis are the same as those in other lady beetles, i.e., the labrum, mandible, maxillae, labium, and hypopharynx. We also found structural specialization indicating adaptation to fungal feeding. On the mouthparts, there are eight kinds of sensilla and two kinds of glandular structures, including sensilla chaetica, sensilla basiconica, sensilla styloconica, sensilla coeloconica, sensilla campaniformia, sensilla placodea, sensilla digitiformia, Böhm bristles, perforated plates, and cuticular pores. This is the first time that sensilla digitiformia has been reported in ladybirds. Finally, variations in mouthparts among ladybirds with differing diets, as well as the putative functions of each of the mouthparts and sensilla, were discussed. This research can provide a reference for understanding the functions of the mouthparts in ladybird feeding behavior and thereby contribute to the development of precise insect behavior regulation and management strategies.

Optimization of the parameters of the pneumatic feed mechanism for precise clustered sowing

The article is devoted to the description of one of the ways to improve the mechanization of sowing, namely, precise sowing in a clustered way. It is analyzed that precise sowing provides a given placement of plants over the area and makes it possible increase productivity, to reduce labor costs for thinning plants, seed consumption and operating costs of the aggregates. Data are presented on the mechanization of sowing row crops in Uzbekistan, on the main advantages and disadvantages of the applied mechanical and pneumatic planters. It is noted that industrial pneumatic feed mechanisms do not meet the increased quality requirements for clustered sowing of cotton seeds in Uzbekistan and are one of the factors limiting the widespread introduction of intensive technology. An analysis is given of the need to develop a pneumatic feed mechanism for precise sowing of row crops in a clustered way for the soil and climatic conditions of Uzbekistan and the justification of its parameters. The data on the study of the technological process of sowing and the refinement of the parameters obtained in analytical calculations are presented. According to the results of experimental studies and tests, the correctness of the theoretical premises and the performance of the experimental feed mechanism were checked. The optimization of the main parameters and operating mode of the feed mechanism for precise sowing in a clustered way has been carried out. The data obtained in the experiments were processed using the PLANEXР program developed for the Personal Computer and regression equations were obtained that adequately describe the evaluation criteria. Therefore, to ensure maximum accuracy of sowing cotton seeds and perform the required quality of work at aggregate operating speeds of 1.66-2.24 m / s, the number of revolutions of the sowing disc should be 23.87-27.62 rpm, and the installation height of the feed mechanism should be within 9.02-9.24 cm. With these values of the factors, criterion Y1, i.e. the number of seeds in the cluster is 3.03-3.28 pieces, criterion Y2, i.e. the distance between the clusters is 14.00-15.57 cm, and criterion Y3, i.e., the length of the clusters is in the range of 0.95-1.12 cm, which meets the agro technical requirements.

Energy Dense Feeding in Premature Infants and Its’ Associated Outcomes

COVID-19 infection in pregnant mothers is associated with higher risk of intrauterine growth retardation and premature births. Very low birth weight infants are more susceptible to neurodevelopmental and chronic respiratory problems. An infant delivered at 33 weeks via caesarean section to a COVID-19 Stage 5A positive mother, weighing 1.43kg at birth. She was kept nil by mouth with parenteral nutrition (PN) support since day five of life until referred to dietitian on day 22 of life for enteral nutrition (EN) establishment. Feeding was administered intermittently via oro-gastric Ryle’s Tube. She was kept under non-invasive ventilation (NIV) mode and had difficulty in weaning from ventilation, leading to slow feeding progress. Initially, enteral trophic feeding was administered using premature infant formula fortified with modular products. In the later stage of feeding, modular products were tapered off and the formula was concentrated. Frequency of bowel output when using fortified formula is lesser compared to when using concentrated and supplemented formula. There is no significant difference in renal profile observed in both stages of feeding. Increasing energy intake using easily digestible sources is preferable as opposed to concentrating feeds even further due to concerns about osmolality and excess administration of other solutes. Intermittent bolus feeding mode may have an effect on dependency on oxygen since intermittent feeds can decrease tidal volume, minute ventilation and dynamic compliance. Additional research is necessary to establish optimal caloric density and nutritional compositions of feedings, feeding mechanisms and its’ effect on feeding tolerance.

Circularly-Polarized Ring Slot Antenna Fed by a V-Shaped Coupling Strip

A design for circularly-polarized (CP) ring slot antennas is described. The antenna is fed by a V-shaped coupling strip loaded with a resistor. For the slot antenna with a thin slot width, the proposed feeding mechanism can directly generate good CP radiation and fine tuning of antenna parameters is unnecessary. When the slot width is increased, CP radiation with low axial ratio can also be obtained as long as the included angle of the V-shaped coupling strip is properly adjusted. Numerical analyses of the key parameters of the V-shaped coupling strip are provided. A number of the CP prototypes with various slot widths are fabricated. Experimental results demonstrate that the feeding mechanism can give good CP performances for the case that the slot width is varied from 0.008 to 0.09 e0, and the antenna gain is not significantly degraded when the loading resistance is small enough.

AN X/Ku DUAL-BAND SHARED APERTURE UNIFORM LINEAR ANTENNA ARRAY FOR AIRBORNE SYNTHETIC APERTURE RADAR APPLICATIONS

An amplitude distribution of shared aperture antenna array for airborne SAR applications using a dual-band (X/Ku-band) synthesis is presented in this research. It is utilizing a linear arrangement with 1 × 8 antenna elements and a series feeding mechanism to operate in the X/Ku bands. The proposed shared aperture antenna array has eight elements providing a uniform array in the X and Ku bands. To realize the proposed scanning array, the X/Ku-band antenna array takes an inter-element spacing of 0.7 λ, which provides a scanning angle of ± 25°. When the space between adjacent antenna arrays is effectively used to reduce the influence of mutual coupling, the synthesis array's X-band and Ku-band antenna arrays can perform well in isolation. The uniform linear array exhibits Side Lobe Level (SLL) of -23.9 dB in X-Band and -24.7 dB in Ku-Band, with maximum realized gains of 14.2 dBi in X-Band and 15.7 dBi in Ku-Band. The isolation between bands and ports exceeds 25 dB. The uniform amplitude distribution shared aperture antenna (UAD SAA) has accepted an SLL performance of -13.5 dB. Additionally, it displays a uniform (X/Ku-band 200/144 MHz) impendence bandwidth that is relatively wide.

Development of technical solutions for modernization of the rotary feed mechanism of a quarry drilling rig

This article substantiates and describes the design and operating principle of an electrohydromechanical rotator, presents the results of experimental studies of a prototype, shows ways to reduce dynamic loads and recommendations for improving the rotary-feeding mechanism of a drilling rig of the SBSh-250MNA-32 type. An improved kinematic and hydraulic diagram of an electrohydromechanical rotary-feeding mechanism and installation of a feed pump with a drive electric motor in the machine room of a drilling rig are presented. A design has also been developed for the electrohydromechanical rotary-feeding mechanism of the drilling rig, which can significantly reduce transmission vibrations, increase durability, and, as a result, the productivity of the machine.

ЭФФЕКТИВНОСТЬ ПРИМЕНЕНИЯ КРИВОШИПНО-ПОЛЗУННОГО ПРИВОДА ДЛЯ ФРЕЗЕРОВАНИЯ ВАФЕЛЬНОГО ФОНА

The paper presents the design of an experimental cutting tool feed drive based on a slider-crank mechanism. A feature of the technology of milling a regular waffle background pattern is the need for regular repetition of cells, usually rectangular shape. This requires the development of a tool feed mechanism that provides а high processing speed and a significant reduction in cutting forces to prevent deformation of the cell shape. The drive design presented in the work provides feed rate up to 43 m/min with cutting speed up to 942 m/min. This eliminates the exit of the mechanism out of the cell dimensions, as well as provides a significant reduction of cutting forces up to 10 N and removes the problem of using coolant (dry machining). This is a feature of the high-speed milling mode, when the feed rate and cutting speed are significantly higher than traditional ones, and the cutting depth does not exceed 1 mm. The productivity of this milling process is much higher than traditional milling modes and, in addition, it causes less heating of the part, as almost all the heat escapes with the chips. The practical significance of the development is the increase of productivity of the equipment for waffle background milling in fuel tanks from aluminium alloys due to the application of the high-speed drive based on the slider-crank mechanism. The authors offered to mount it instead of the standard spindle on large-sized milling gantry-type machines. This makes it possible to use the high-speed milling modes at cutting forces of several newtons for reducing the weight of the power and moving parts of the drive and increasing the feed rate.