Horn Type Research Articles

Integration of $S$ /Ka/$D$ -Band Antennas in LTCC With a Cylindrical Radome for Triband Applications

This paper presents the integration of S /Ka/D -band antennas in a low-temperature cofired ceramic (LTCC) package. Three types of antennas, microstrip patch, grid array, and step-profiled horn, operating at different bands are compactly assembled in the same substrate. For electromagnetic isolation, a specific layout and extra-shielding structures, such as fences of metallic vias and air cavities, are designed to reduce the unwanted coupling between antennas. In addition to the antennas, a cylindrical radome is introduced closely attached to the surface of the LTCC substrate. Since radome acts as a dielectric superstrate, its influence on radiation performance is also taken into consideration, especially for D -band operation, where a ring-shaped cavity is introduced to suppress the detrimental propagation of surface waves inside radome and enhance the gain as a consequence of dielectric loading effect. Measured results agree well with simulation. Proposed triband antennas, working at three frequencies 3, 30.5, and 120 GHz, achieve broadside gains of 6.51, 9.74, and 13.36 dBi with -10 dB fractional impedance bandwidths of 15.3%, 6.1%, and 6.5%, respectively.

Design and experimental investigation on longitudinal-torsional composite horn considering the incident angle of ultrasonic wave

The composite vibration mode type of ultrasonic horn has been widely employed in ultrasonic vibration drilling. In order to explore the effect of the incident angle of the ultrasonic wave on longitudinal-torsional composite (LTC) horn, the reason for the mode-conversion and the vibrational characteristics of such horn firstly were analyzed on the basis of elastic wave-field theory. Then, a 3D model was developed with helical slots with different angle set in the conical section of the composite horn, and the vibration modal of the output end face of the horn was analyzed using the finite element analysis (FEA) method. It was found that the incident angle of ultrasonic wave exhibited a significant influence on the vibration modal at the output end face of the horn. The torsional vibration and the longitudinal vibration were changed significantly at the output end face of the horn when the incident angle was 47.6° and 67.2°, and the measured amplitude ratio of the torsional vibration to the longitudinal vibration in the former was improved by 4.9 times than that in the latter. Simultaneously, in both cases, the error of resonant frequency between the measurement and the simulation value reached 1.9% and 1.3%, respectively. It was observed from the ultrasonic vibration drilling test that the higher the amplitude ratio of the torsional vibration to the longitudinal vibration (AT/AL), the more the average drilling force was reduced and the better machined quality could be obtained. The results of this study should be well considered for further reference when designing longitudinal-torsional composite horn with different materials in ultrasonic vibration drilling.

Investigating vibration characteristics of magnetostrictive transducers for air-coupled ultrasonic NDT of composites

In this study, high-power ultrasonics has been used for non-contact nondestructive testing of composites. Air-coupled magnetostrictive ultrasonic transducers provide reasonable amplitudes of horn oscillations even if this type of ultrasonic stimulation is close to the idle mode. Four types of ultrasonic horns have been designed and manufactured in order to choose an optimal horn configuration. For each horn, the dependence of vibration amplitude on ultrasonic unit power has been found to exhibit a good match between the theoretical and experimental results. The resonance frequencies and amplitudes of oscillatory velocity were experimentally evaluated by using the technique of scanning laser vibrometry and modeled by means of the Autodesk Inventor software. An air-coupled magnetostrictive transducer, in conjunction with an optimized horn, has been used in the evaluation of impact damage in a graphite epoxy composite and detection of water and excessive epoxy adhesive in an aviation honeycomb panel. It is expected that the technique of air-coupled ultrasonics may be useful for inspecting thin, fragile and hydrophilic materials.

Microstructural refinement of 355 aluminium alloys by ultrasonic melt treatment (UST)

Chemical grain refining of high-silicon-content aluminium alloys, such as 355 alloy, is impaired by the high silicon content. One solution is the use of ultrasonic melt treatment (UST). This study sought to determine the duration of UST and type of horn (steel or Ti) required to achieve optimal grain refining in these alloys. Samples produced by conventional casting underwent UST for different times with steel and Ti horns and were compared with as-cast samples. For all the conditions studied, analysis of the samples showed that UST is an effective grain refining technique and yields satisfactory values of average grain size and primary and secondary dendrite arm spacing (λ1, λ2) as well as low porosity. The chemical composition of the samples was analysed by SEM–EDS mapping and point analysis to identify the intermetallic phases before and after UST. Best results were achieved after only 20 s of UST with a steel horn. UST for this length of time with a steel horn produced a homogeneous microstructure and possible homogeneous mechanical properties. Grain size was 160 µm; primary dendrite arm spacing, or dendrite cell size, was 130 µm; secondary arm spacing was approximately 18 µm; and Vickers hardness was approximately 95 HV.

Cutaneous Rhinosporidiosis Presenting as Cutaneous Horn and Verrucous Plaque.

Sir, A 52-year-old male presented with a growth over the right little finger and the left popliteal fossa since 1 year. He gave a recurrent history of nasal stuffiness, difficulty in breathing, and change in voice. He was diagnosed and operated for nasal rhinosporidiosis four times within the last 3 years. He had a habit of regular pond bathing. Dermatological examination showed a verrucous plaque measuring 3 × 4 cm2 covering the entire palmar and medial aspect of the right little finger along with a horn-like projection over the right popliteal fossa. Examination of nasal mucosa revealed a polypoidal, grape-like growth with a red shiny surface covering the medial aspect of right anterior nare [Figure 1a–d]. His blood counts, erythrocyte sedimentation rate (ESR), blood sugar, liver, and renal function tests were within normal limits. Serology for human immunodeficiency virus (HIV) was negative. Systemic examination was unremarkable. Chest X-ray and ultrasound abdomen and pelvis were normal. Histopathology from lesions over finger and growth over right popliteal fossa showed multiple thick-walled mature sporangia-releasing endospores, with surrounding areas showing marked inflammatory reaction suggestive of cutaneous rhinosporidiosis [Figure 2a and b]. Patient was started on tablet dapsone 100mg/day and tablet cotrimoxazole double strength twice daily. However, there was minimal improvement in skin lesions despite 2 months of treatment.Figure 1: (a) Polypoidal growth inside the right anterior nare. (b) Verrucous plaque on the palmar aspect ofright little finger . (c) Verrucous plaque on the dorsal aspect of right little finger. (d) Cutaneous horn in the popliteal fossaFigure 2: (a) Hematoxylin and eosin; 100×: multiple sporangia in various stages of maturation. (b) Hematoxylin and eosin; 400×: sporangia-containing endosporesDiscussion Rhinosporidiosis is a chronic granulomatous infection caused by Rhinosporidium seeberi.[1] It commonly affects mucosa with nasopharynx (70%) being the most common site involved followed by ocular (15%), oral, and genital mucous membranes. Four forms of rhinosporiosis have been described – nasal, ocular, cutaneous, and disseminated. Cutaneous lesions are generally associated with mucosal lesions. Based upon the modes of spread, three morphological presentations of cutaneous rhinosporidiosis have been described i.e., (1) satellite lesions, in the skin adjacent to the nasal rhinosporidiosis; (2) generalized cutaneous type, occurring via hematogenous dissemination; and (3) primary cutaneous type without any visceral involvement associated with direct inoculation of organisms on the skin. Cutaneous lesions are usually in the form of friable warty growths.[2] Other presentations such as verrucous plaques, polypoidal growths, subcutaneous nodules, furuncle, ecthyma, and friable nodules have been reported.[34] Because of varied clinical presentations, it can be easily confused with tuberculosis verrucosa cutis, warts, cutaneous leishmaniasis, bacillary angiomatosis, granuloma pyogenicum, Kaposi's sarcoma, and deep mycoses such as cryptococcosis. Clinical diagnosis is usually confirmed by fineneedle aspiration cytology and histopathological examination of the resected tissue. However, definitive diagnosis is made by histopathology which shows sporangia at various stages of maturation consisting of large, thick-walled spherical structures, and smaller daughter cells termed endospores, which can be seen with fungal and routine hematoxylin and eosin staining.[4] Though definitive treatment remains surgical excision with cauterization, recurrence rate is still high due to incomplete excision and accidental spillage of sporangia to the adjacent tissue. Among medical treatments, dapsone has been found to be somewhat effective which arrests the maturation of the sporangia, inducing stromal fibrosis and accelerating its degenerative changes.[5] Our case had nasal rhinosporidiosis and skin lesions were on the right little finger and left popliteal fossa possibly due to autoinoculation. The presence of nasal rhinosporidiosis which was previously proven by histopathology and culture led to the suspicion of cutaneous involvement, which was further supported by histopathology from the skin lesion. The patient was started on dapsone and cotrimoxazole (double dose) without appreciable improvement after 2 months, which was expected. Among various presentations, verrucous plaque-like morphology has been reported by many authors.[34] However, cutaneous horn-like presentation of rhinosporidiosis has been reported by few.[4] Our patient had two types of morphologies, verrucous plaque and cutaneous horn, and we believe it will add to the pool of evidences of atypical presentations of cutaneous rhinosporidiosis. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest. Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Plantain diversity in the Democratic Republic of Congo and future prospects

The Democratic Republic of Congo (DR Congo) is the largest centre of diversity for plantain (Musa AAB subgroup). In the the 1940s and 1950s descriptions of a collection of 56 accessions at Yangambi (INERA ex INEAC) were published. Between 2005 and 2015, new collection missions covering 306 villages of DR Congo gave morphological descriptors of 107 cultivars, which were established in two fields at the University of Kisangani (UNIKIS). Ninety-seven of these cultivars are completely characterized and grouped into French (64 accessions), False Horn (23 accessions) and Horn (10 accessions) types. Three plant size categories were distinct in the French plantain accessions (24 giant, 22 medium and 12 small) but less obvious within the False Horn and Horn accessions. A similar proportion between the three bunch types was found for dwarfism. The dominant bunch orientation was pendulous (71% of all accessions). Different colours of pseudostem (green, dark green, mottled red and black) and of immature fruit peel (brown, dark green, green, red and yellow) were recorded, green being predominant. The collected cultivars will be further characterized for their agronomic and postharvest performance, used in breeding and characterized at the molecular level.

Rhinoceros beetle horn development reveals deep parallels with dung beetles.

Beetle horns are attractive models for studying the evolution of novel traits, as they display diverse shapes, sizes, and numbers among closely related species within the family Scarabaeidae. Horns radiated prolifically and independently in two distant subfamilies of scarabs, the dung beetles (Scarabaeinae), and the rhinoceros beetles (Dynastinae). However, current knowledge of the mechanisms underlying horn diversification remains limited to a single genus of dung beetles, Onthophagus. Here we unveil 11 horn formation genes in a rhinoceros beetle, Trypoxylus dichotomus. These 11 genes are mostly categorized as larval head- and appendage-patterning genes that also are involved in Onthophagus horn formation, suggesting the same suite of genes was recruited in each lineage during horn evolution. Although our RNAi analyses reveal interesting differences in the functions of a few of these genes, the overwhelming conclusion is that both head and thoracic horns develop similarly in Trypoxylus and Onthophagus, originating in the same developmental regions and deploying similar portions of appendage patterning networks during their growth. Our findings highlight deep parallels in the development of rhinoceros and dung beetle horns, suggesting either that both horn types arose in the common ancestor of all scarabs, a surprising reconstruction of horn evolution that would mean the majority of scarab species (~35,000) actively repress horn growth, or that parallel origins of these extravagant structures resulted from repeated co-option of the same underlying developmental processes.

Influence of gear parameters on dynamic characteristics of an ultrasonic vibration system

A spiral bevel gear is subject to a special load in ultrasonic lapping, which is not only a processing object but also a processing tool, it is necessary to study dynamic characteristics of an ultrasonic vibration system. First, the spiral bevel gear is reasonably simplified to a frustum, which is then combined with a horn to form a new type of composite horn. Based on the theory of plane longitudinal wave propagation, the resonance mathematical model of the gear’s ultrasonic vibration system is established, and the frequency equation of the vibration system with gear characteristic parameters is obtained. Second, the frequency and displacement characteristics of an ultrasonic vibration system are analyzed by means of design examples, and the influence of the law of gear characteristic parameters on dynamic characteristics of the vibration system is studied. Finally, ultrasonic lapping and vibration measurement experiments are carried out using two pairs of different hypoid gears. The results show that the change in dynamic characteristics of an ultrasonic vibration system has a large influence on the finished machining quality of the gear. Therefore, it is necessary to consider the gear characteristic parameters when ultrasonic vibration system is designed. The research results provide an accurate theoretical basis for the detailed design of an ultrasonic lapping vibration system.

Effect of operating pressure on the performance of ultrasound-assisted oxidative desulfurization (UAOD) using a horn type sonicator: Experimental investigation and CFD simulation

In the present work, experimental and simulation investigations have been conducted on the pressurized ultrasound-assisted oxidative desulfurization (UAOD) of kerosene using a direct probe sonicator system. The effects of various operating parameters including pressure, ultrasonic power, and sonication time on the performance of UAOD process have been examined. The Box– Behnken design as a subset of the response surface methodology (RSM) has been employed to find the optimum conditions and to analyze the effects of different operating parameters on the performance of UAOD process. 96% sulfur removal of kerosene was achieved using operating pressure of 0.03 barg, ultrasound power of 390 W, and sonication time of 22 min followed by liquid–liquid extraction. In addition, calorimetric tests have been carried out to determine the acoustic pressure amplitude at the tip of the probe. Pressure distribution and velocity magnitude of the system obtained by computational fluid dynamic (CFD) was in agreement with the calorimetric and experimental analysis results.

Comments on the recent changes in taxonomy of pygmy unicorns, with description of a new species of Metopomystrum from Brazil (Insecta, Tetrigidae, Cleostratini, Miriatrini).

The tribe Cleostratini Bolívar, 1887 sensu Storozhenko, 2016 does not represent a monophyletic taxon because it gathers various Tetrigidae genera with various types of horn and prolongation of frons or vertex. Prolongation of these structures is present in morphologically and biogeographically distant groups. We do not regard Miriatrini Cadena-Castañeda & Cardona, 2015 synonymous with Cleostratini because the genus Miriatra Bolívar, 1906 belongs to a group of genera distant from Cleostratus Stål, 1877. There is no adequate diagnosis for proposed groups of genera forming tribes Cleostratini or Miriatrini. Miriatrini stat. resurr. are monotypic and include only Miriatra, Cleostratini are monotypic as well. Apteromystrum Storozhenko, 2016 syn. n. is regarded synonymous with Metopomystrum, M. apterum comb. resurr., M. amazoniensis comb. resurr. and Miriatra brevifastigiata (Cadena-Castañeda & Cardona, 2015), comb. n. are not Metopomystrum member. Herein a new species of pygmy unicorn, Metopomystrum muriciense Silva & Skejo, sp. n., is described from Atlantic Forest remnants in northeast of Brazil, collected on the Estação Serra do Ouro (municipality of Murici, Alagoas state). Distribution data, morphological characterization, and an identification key to Metopomystrum species are also presented.

Proceedings of the First Workshop on Coalgebra, Horn Clause Logic Programming and Types

Proceedings of the First Workshop on Coalgebra, Horn Clause Logic Programming and Types

Proceedings of the First Workshop on Coalgebra, Horn Clause Logic Programming and Types

Proceedings of the First Workshop on Coalgebra, Horn Clause Logic Programming and Types

Proceedings of the First Workshop on Coalgebra, Horn Clause Logic Programming and Types

Proceedings of the First Workshop on Coalgebra, Horn Clause Logic Programming and Types

Proceedings of the First Workshop on Coalgebra, Horn Clause Logic Programming and Types

Proceedings of the First Workshop on Coalgebra, Horn Clause Logic Programming and Types

Proceedings of the First Workshop on Coalgebra, Horn Clause Logic Programming and Types

Proceedings of the First Workshop on Coalgebra, Horn Clause Logic Programming and Types

Müllerian anomaly in a woman with Hirschsprung's disease

Müllerian anomalies are usually isolated or found in association with abnormalities of the renal tract. Rarely, they are encountered with coexisting Ggastrointestinal anomalies. Similarly, Hirschsprung's disease may coexist with additional...

Experimental and numerical studies on ultrasonic welding of dissimilar metals

Ultrasonic metal welding (USMW) is gaining popularity for joining thin and dissimilar metal sheets and foils. In the present study, a new type of booster and horn is proposed and modeled with adequate precision. The modal analysis module of finite element method (FEM) is used to analyze the effects of different step lengths and fillet radius on its natural frequency. The dynamic analysis has also been performed to find out the stress distribution in both parts under cyclic loading conditions. It enables to locate the highly stressed nodal regions (hot areas), and the relevant temperature field is consequently determined. A 0.02 and 0.008% errors have been noticed for horn and booster while comparing FEM results with the experimental values respectively. The experiments are conducted on the 0.3Al-0.3Cu specimens with the designed parts to study the effects of various controllable process parameters like vibration amplitude, weld pressure, and weld time on the tensile shear and T-peel strengths. Intermetallic compound of Al2Cu with a layer of 1.5-μm thickness has been formed for the good weld samples, and it is very much sensitive towards the parameter combinations. This paper provides an insight not only to produce high-quality welds but also to solve many industrial issues by explaining the comprehensive background theories on fatigue and vibro-thermographic analyses of the booster and horn along with detailed microscopic analyses of fractured surface.

Advances in genome-wide association studies for important traits in sheep and goats.

Genome-wide association study (GWAS), an effective strategy to identify genetic variants associated with complex traits, has been used to study candidate genes of economical traits in animals. With the recent completion of sheep and goat genomes, single nucleotide polymorphism (SNP) chips of different densities are developed and commercialized. All these advances have enlarged the collection of molecular markers and also shed new light on the genetics of traits of interest in sheep and goats. In this review, we focus on the adoption of GWAS for important traits in sheep and goats, such as horn types, wool, dairy, growth and meat, reproduction and disease types, etc., and summarize the populations, major statistical methods and results of the GWAS analysis. Moreover, we also discuss the current state of GWAS, aiming to provide a reference for further studies on the genetic background of the important traits of sheep and goats by GWAS.

Modelling of a High Power Microwave (HPM) Source using 300 KV Marx Generator and Horn Type Antenna

Objectives: To analyse a High Power Microwave (HPM) source connected to a horn antenna by a mathematical model and feeding it with various pulse shapes to find its response. To estimate the E far-field produced and compare it with experimental measurements. Methods/Statistical analysis: A HPM source is built using spark gap switch and Marx generator. Efforts are made to reduce the rise time of the radiated pulse by experimentally varying the spark gap distance and using different gases as di-electric medium. A peaking switch was then designed that could achieve a rise time of 1 nS. The energy discharged at the spark gap (peaking switch) is radiated using a horn type antenna. Findings: In the numerous simulations it was found that a sharp rising edge of the radiated pulse can be achieved if we could minimize the peaking stage inductance. A sharp rising edge gives high peak radiated power resulting in higher E far-field intensity, which is useful for the intended applications of HPM systems. Experimental results to measure the E far-field were coherent with the mathematical model; however, in order to make the mathematical model more accurate with the practical results, a scaling factor was empirically derived. Application/Improvements: During the experiments a range field product (r.Efar-field ) of more than 200 kV was achieved. Although this compares well with some of the contemporary systems. It is much less than 7.2 MV reported elsewhere. To achieve it, some improvements are required to further reduce the rise time of radiated pulse. This can be done by better impedance matching of the radiating antenna with the peaking stage and improvement in the Marx generator switching stages . Keywords: HPM, Pulser, PFN (Pulse Forming Network), Spark-Gap

Unveiling genomic regions that underlie differences between Afec-Assaf sheep and its parental Awassi breed

BackgroundSheep production in Israel has improved by crossing the fat-tailed local Awassi breed with the East Friesian and later, with the Booroola Merino breed, which led to the formation of the highly prolific Afec-Assaf strain. This strain differs from its parental Awassi breed in morphological traits such as tail and horn size, coat pigmentation and wool characteristics, as well as in production, reproductive and health traits. To identify major genes associated with the formation of the Afec-Assaf strain, we genotyped 41 Awassi and 141 Afec-Assaf sheep using the Illumina Ovine SNP50 BeadChip array, and analyzed the results with PLINK and EMMAX software. The detected variable genomic regions that differed between Awassi and Afec-Assaf sheep (variable genomic regions; VGR) were compared to selection signatures that were reported in 48 published genome-wide association studies in sheep. Because the Afec-Assaf strain, but not the Awassi breed, carries the Booroola mutation, association analysis of BMPR1B used as the test gene was performed to evaluate the ability of this study to identify a VGR that includes such a major gene.ResultsOf the 20 detected VGR, 12 were novel to this study. A ~7-Mb VGR was identified on Ovies aries chromosome OAR6 where the Booroola mutation is located. Similar to other studies, the most significant VGR was detected on OAR10, in a region that contains candidate genes affecting horn type (RXFP2), climate adaptation (ALOX5AP), fiber diameter (KATNAl1), coat pigmentation (FRY) and genes associated with fat distribution. The VGR on OAR2 included BNC2, which is also involved in controlling coat pigmentation in sheep. Six other VGR contained genes that were shown to be involved in coat pigmentation by analyzing their mammalian orthologues. Genes associated with fat distribution in humans, including GRB14 and COBLL1, were located in additional VGR. Sequencing DNA from Awassi and Afec-Assaf individuals revealed non-synonymous mutations in some of these candidate genes.ConclusionsOur results highlight VGR that differentiate the Awassi breed from the Afec-Assaf strain, some of which may include genes that confer an advantage to Afec-Assaf and Assaf over Awassi sheep with respect to intensive sheep production under Mediterranean conditions.