Flange Formation Research Articles

Finding and analyzing of the energy and force parameters of the flange formation process by orbital stamping by rolling

The study was carried out based on the developed mathematical model of the discrete hydraulic actuator. The model is characterized by considering the nonlinear friction based on the LuGre model, the bidirectional motion of the asymmetric hydraulic cylinder, and the elastic properties of the fluid. A series of simulation experiments on the braking process of the hydraulic actuator in the discrete control mode were carried out. The quantitative relationship between the rod braking time, the maximum peak pressure in the hydraulic cylinder chambers, the value of the initial rod velocity and the inertial mass of the moving parts are determined. Based on the research results it is possible to predict the braking time of the rod and the maximum peak pressure in the hydraulic cylinder chambers under various operating conditions and inertial loads. These predictions can be used in the settings and design process of hydraulic actuators.

Numerical simulation and experimental study on electromagnetic punching-flanging process of 6061 aluminum alloy sheets

In order to shorten flanging process and improve manufacturing efficiency, an electromagnetic punching-flanging (EMPF) process was proposed in this work. The EMPF experiments were performed with 6061 aluminum alloy sheets and an electromagnetic-mechanical-fracture numerical simulation was established. The flange formation mechanism and relationships between die-fitting gaps/flange heights and discharge energies were analyzed. The thickness reductions of flanged parts were measured to characterize the flange forming quality. Results showed that sheet deformations during EMPF process mainly occurred in the flanging stage of sheets, and the relationship between flange heights and discharge energies could be represented by a quadratic function. The appropriate increase of discharge energies could reduce the die-fitting gaps. The die-fitting gap (0.506 mm) was minimum under the discharge energy of 7 kJ, which was an optimum discharge energy in this work. The thickness reduction gradually slowed down from this position to fillet positon. The maximum and average thickness reduction rates relative to sheet thickness were 13.6 % and 8.2 % for optimum discharge energy, respectively. Numerical simulation and experimental investigations illustrated that the electromagnetic punching-flanging process can be used for manufacturing flanged parts with high quality.

Finding and analyzing of the energy and force parameters of the flange formation process by orbital stamping by rolling

A characteristic feature of the details considered in the article is the increased diameter of the flange. At the Department of Aircraft Production Technology of the Scientific and Educational Mechanical and Mechanical Engineering Institute of the Kyiv Polytechnic Institute named after Igor Sikorskyi developed an original technological process for manufacturing products with a developed flange part using the positive effects of the progressive rolling stamping method. The method has energy-strength advantages over traditional methods of manufacturing parts with relatively thin structural elements. The center of application of such technologies is expanding more and more, but the basic technological calculations of process parameters have not yet been introduced widely enough into production practice. The proposed sequence of technological calculations and basic parameters of specialized installations for rolling stamping.

The Giardia ventrolateral flange is a lamellar membrane protrusion that supports attachment.

Attachment to the intestinal epithelium is critical to the lifestyle of the ubiquitous parasite Giardia lamblia. The ventrolateral flange is a sheet-like membrane protrusion at the interface between parasites and attached surfaces. This structure has been implicated in attachment, but its role has been poorly defined. Here, we identified a novel actin associated protein with putative WH2-like actin binding domains we named Flangin. Flangin complexes with Giardia actin (GlActin) and is enriched in the ventrolateral flange making it a valuable marker for studying the flanges’ role in Giardia biology. Live imaging revealed that the flange grows to around 1 μm in width after cytokinesis, then remains uniform in size during interphase, grows in mitosis, and is resorbed during cytokinesis. A flangin truncation mutant stabilizes the flange and blocks cytokinesis, indicating that flange disassembly is necessary for rapid myosin-independent cytokinesis in Giardia. Rho family GTPases are important regulators of membrane protrusions and GlRac, the sole Rho family GTPase in Giardia, was localized to the flange. Knockdown of Flangin, GlActin, and GlRac result in flange formation defects. This indicates a conserved role for GlRac and GlActin in forming membrane protrusions, despite the absence of canonical actin binding proteins that link Rho GTPase signaling to lamellipodia formation. Flangin-depleted parasites had reduced surface contact and when challenged with fluid shear force in flow chambers they had a reduced ability to remain attached, confirming a role for the flange in attachment. This secondary attachment mechanism complements the microtubule based adhesive ventral disc, a feature that may be particularly important during mitosis when the parental ventral disc disassembles in preparation for cytokinesis. This work supports the emerging view that Giardia’s unconventional actin cytoskeleton has an important role in supporting parasite attachment.

Untangling the Gordian knot\u2014further resolving the super-species complex of 300-million-year-old xiphosurids by reconstructing their ontogeny

The group Xiphosurida (horseshoe “crabs”) is today only represented by four species. However, in the fossil record, several dozen species have been described, especially from the Carboniferous (about 300 million years ago). Several species have been interpreted as representatives of Euproops or Belinurus, but there is ongoing discussion which of these species are valid and how they can be differentiated. Recent studies suggested that differences in the timing of individual development could provide information for species distinction, exemplified by studies on Euproops danae (Mazon Creek, USA) and Euproops sp. (“Piesproops”; Piesberg, Germany). For this study, we reinvestigated all Carboniferous xiphosurids from the British Coal Measures stored in the collections of the Natural History Museum London. Size comparisons of the specimens revealed nine size groups; the smaller specimens were originally labelled as Belinurus, the larger ones as Euproops. The nine size groups exhibit five different morphotypes differing in structures surrounding the posterior shield (= thoracetron): spines of different lengths and, in larger specimens, a more or less developed flange. Two of these morphotypes show significantly longer spines than the remaining specimens and could be conspecific as E. anthrax. The remaining specimens are interpreted as growth series of another species, presumably of E. rotundatus. An ontogenetic flange formation is also known from E. danae and the “Piesproops”, but the timing differs between all three species. In E. rotundatus, the flange develops rather late, but then comparably abruptly, which makes this development more metamorphic in relation to development in the other species.

Flange formation in aluminium alloy EN AW 6060 tubes by radial extrusion with the use of a limit ring

The paper presents the results of tube flange forming by radial extrusion. The process was carried out according to two variants: with and without the use of a limit ring. The objective of the study reported in this paper was to determine the effect of the die corner radius and the gap height on the course of the radial extrusion process, determine the limit diameter of the flange and effect of limit ring dimensions on the radial extrusion process performed with the use of this ring. The research was performed in cold working conditions with the use of tubular billet made of 6060 aluminium alloy. The analyses were based on experimental tests using a testing machine and numerical calculations based on FEM. Obtained results demonstrate that the use of a limit ring has a positive effect on the state of stress in the extruded flange, which – in turn – allows to produce flanges with relatively big diameters. Such flanges are also characterised by lower thickening than those produced by radial extrusion process without ring.

Evaluation of Parametric Significance in Friction Welding Process of AA1100 and Zr705 Alloy using Finite Element Analysis

The purpose of this work was to assess friction welding of AA1100 and Zr705 alloy. Finite element analysis was adopted to analyze the friction welding process. The process parameters were frictional time, frictional pressure, rotational speed and forging pressure. The joints were evaluated for their strength, bulk deformation, penetration and flange formation. The heat affected zone and metal flow across the weld joints were also studied. For friction welding of AA1100 and Zr705 alloy, the forging pressure should be 1.25 times of the frictional pressure.

Mouthparts and stylet penetration of the lac insect Kerria lacca (Kerr) (Hemiptera:Tachardiidae)

Hitherto less known aspects on mouthpart morphology and penetration mechanism of the lac insect Kerria lacca have been explored. Unique details of the mouthparts, i.e. morphology of labium and stylets and salivary sheath have been brought out. The gross morphology of the mouthparts though resembled other plant sucking homopterans; a two-segmented labium with symmetrically distributed six pairs of contact-chemoreceptors on its surface was distinct; the mandibular stylets had serrations on its extreme apical region, while the maxillary stylets had their external surface smooth with parallel longitudinal grooves on their inner surface. Formation of flanges, salivary sheath and penetration pathway observed along with probing and penetration of the stylets intracellularly up to the phloem cells, as illustrated herein, are the addition to the existing knowledge on the structural details of the mouthparts and the feeding behavior thereupon.

Lateral Load Tests on a Two-Story Unreinforced Masonry Building

A full-scale two-story unreinforced masonry (URM) building was tested in a quasistatic fashion to investigate the nonlinear properties of existing URM structures and to assess the efficiency of several common retrofit techniques. This paper presents the main experimental findings associated with the nonlinear properties of the original URM structure. The test structure exhibited large initial stiffness and its damage was characterized by large, discrete cracks that developed in masonry walls. Significant global behavior such as global rocking of an entire wall, and local responses such as rocking and sliding of each individual pier were observed in the masonry walls with different configurations. In addition, formation of flanges in perpendicular walls and overturning moments had significant effects on the behavior of the test structure. A comparison between the experimental observations and the predictions of FEMA 356 provisions shows that major improvements are needed for this latter methodology.

Reconstructing a complex early Neoproterozoic eukaryote, Wynniatt Formation, arctic Canada

Flanged filamentous microfossils from two geographically separated assemblages in the early Neoproterozoic Wynniatt Formation, arctic Canada, co-occur with flanged Clavitrichoides -type filaments, flanged Osculosphaera-type vesicles and wrinkled, bi-layered vesicles assigned to a new acritarch form-taxon Plicatosphaeridium impostor n. gen., n. sp. Marked similarities in morphological and microstructural detail identify most, if not all, of these forms as components of a single, relatively complex, multicellular eukaryote, Cheilofilum hysteriopsis n. gen., n. sp. The filamentous, occasionally branched thallus was composed of large cylindrical cells, and extended via rupture of cell termini. Filaments originated from Clavitrichoides -type or Osculosphaera -type vesicles via a similar process of rupture, flange formation and apical extension. Presence of a distinctively mottled wall texture supports the ontogenetic relationship of Wynniatt Cheilofilum, ‘Clavitrichoides’ and ‘Osculosphaera,’ and provides circumstantial evidence for including a Plicatosphaeridium phase. Despite superficial similarities, Cheilofilum cannot be interpreted as a filamentous cyanobacterium, strobilating scyphozoan or polychaete worm tube. The distinctive cytokinesis of the filamentous component has close analogues among the annellophores and/or phialides (conidiophores) of various hyphomycetous fungi, though its large size and absence of an associated mycelium argue against its placement within the Fungi. Unambiguous fungal synapomorphies are expressed in co-occurring Tappania, however, and both Cheilofilum and Tappania include a closely comparable Clavitrichoides -type phase in their life cycle.

Elongational flow processing of ceramics

Extrusion and injection moulding are well-established procedures for shaping ceramics and they rely principally on the shear flow of crowded (50–60 vol%) suspensions of powder in molten waxes or polymers. Recently a number of simpler shaping operations have become available in which it is the elongational flow of such suspensions which confers shape. These have emerged against the prevailing expectation that crowded suspensions could not sustain high elongational strains and the intuitive belief that where thermoplastic polymers are used, the shape would collapse on subsequent reheating to expel the organic vehicle. This review describes some of the processes, namely, vacuum forming, blow moulding, film blowing, melt spinning, the formation of flanges and the manufacture of foams. The manufacturing operation is completed, in each case, by removing the organic vehicle and sintering the powder assembly.

Isolation and Characterization of Thermococcus barossii, sp. nov., a Hyperthermophilic Archaeon Isolated from a Hydrothermal Vent Flange Formation

A new hyperthermophilic microorganism, Thermococcus barossii, was isolated from rock fragments of a hydrothermal vent flange formation, located along the East Pacific Rise of the Juan de Fuca Ridge. This organism is obligately anaerobic and grows over a temperature range of at least 60-92 degrees C in artificial seawater-based media, containing elemental sulfur, tryptone and yeast extract. The addition of a maltooligosaccharide mixture and tungsten to this medium improved growth to some extent. At the Topt for growth (82.5 degrees C), cell densities as high as 4 x 10(8) cells/ml could be obtained in 18-liter batch fermentations, with a doubling time of approximately 40 minutes, if culture access to elemental sulfur was sufficient. In continuous culture at the same temperature, comparable cell densities could be obtained but only at slower growth rates. Morphologically, T. barossii is coccoid-shaped, forming irregularly-shaped spheres; under optimal conditions, these coccoids become more regular and smaller, a characteristic of other hyperthermophilic archaea. Negatively-stained preparations showed no pili or flagella associated with the cell surface. 16S rRNA sequencing reveals that T. barossii is most similar to Thermococcus celer (99.7%). Yet, further comparisons with T. celer showed that T. barossii is a new Thermococcus species: different growth temperature optimum (82.5 degrees C vs. 88 degrees C), obligate requirement for sulfur, higher G + C content (60% vs. 56.7%) and 47.7% DNA-DNA hybridization. The nucleotide and translated amino acid sequence for the gene encoding a DNA polymerase from T. barossii was compared to sequences of related genes from other Thermacoccales. The polymerase phylogenies were congruent with those obtained from the 16S rRNA phylogenetic analyses. Based on the high degree of similarity among members of the genus Termococcus for the criteria used thus far, aspects of enzymology may be an important mechanism of differenting one species from another.

Observations on Leafhopper Ingestion-Egestion Behavior: Its Likely Role in the Transmission of Noncirculative Viruses and Other Plant Pathogens12

Descriptions of two membrane-feeding systems for direct observation of leafhopper probing and feeding behavior are presented. One system is for use with modified compound microscopes, the other with standard stereomicroscopes. Basically, leaf-hoppers within an insect chamber are allowed to probe through a parafilm membrane into a feeding chamber containing diet comprised of distilled water with 5% sucrose to stimulate ingestion, methylene blue to stain the salivary sheath, and India ink particles to indicate flow of solution into or out of the maxillary food canal of the stylet bundle. Preprobing activities, flange formation, stylet penetration, sheath formation, ingestion, and egestion are reported as they were observed at high magnification from the diet side of the membrane. Detailed observations of the membrane feeding behavior of leafhoppers, especially the aster leafhopper, Macrosteles fascifrons (Stal), revealed that these insects usually egest material from the foregut (maxillary food canal, cibarial sucking pump, pharynx, and esophagus) one or more times during feeding. Initial periods of egestion are nearly always preceded by periods of prolonged ingestion. Periods of intermittent egestion sometimes lasted for as long as 10 min, and insects often egested shortly before terminating probes. When egestion occurs, materials flow out of the stylet food canal in the same steady manner in which they enter it during ingestion, indicating that the sucking pump is able to function normally in either direction. At times, egestion obviously served to free the sheath and food canal openings of blocking particles. Evidence of leafhopper egestion, along with very recent electron microscopical observations of virus retention sites in the foreguts of leafhopper vectors, is interpreted as confirming the previously proposed hypothesis that leafhoppers transmit semipersistent viruses, such as maize chlorotic dwarf virus and rice tungro virus(es), and other noncirculative plant pathogenic pathogens via an ingestion-egestion mechanism.

Hole flanging and punching of circular plates with conically headed cylindrical punches

To investigate the mechanics of the hole-flanging process, the quasi-static drifting and punching of thin circular plates with conically headed cylindrical punches was carried out for different materials. The deformation modes of the defected plates and the loads associated with them at different stages of punch penetration were obtained and the results are analysed by use of an elementary theory. The neck characteristics in the flange formation, which are of basic types—lip, petal and plug—were found to be dependent on punch semi-angle, material, and size of the initial hole in the plate. The change-over from lip to petal mode and the stage at which fracture occurs were studied. A simple analysis that predicts some features of neck formation, the onset of plugging and features of fracture development is also given and results obtained by its use are compared with experimental results.

Modes of union and interaction between parasite and host in the Loranthaceae. VII. Some Australian Loranthoideae with exceptional features

Specimens received from Australia during 1961 and 1962 included types of attachment additional to those described in part VI (Thoday 1961). In particular Diplatia maideni from the Northern Territory, on species of Acacia , had formed longitudinally running haustorial strands in the outer phloem of the host. From these parallel strands, slender branches penetrated radially, with further ramifications, reaching the host cambium in many places and forming ‘sinkers’ grafted into the wood. On some hosts the parasite had formed strands upwards as well as downwards. Another species of Diplatia , D. grandibractea , had formed on Eucalyptus microtheca a large attachment bearing a group of shoots. The parasite extended downwards as a haustorial strand longitudinally against the host wood. Between the dark surface tissues of the parasite and the smooth pale bark of the Eucalyptus was a zone marked by transverse fissures and ridges where host and parasite tissues were interlocked, the parasite having formed marginal tongues growing out actively into the host, with some response on the part of the host. In the strands of D. maideni , groups of stone cells and xylem are differentiated and the prominent xylem strands increase radially by an external meristematic layer. Parenchy­matous rays are formed in the process and in them stone-cell masses are differentiated, supplementing the larger masses formed in the rest of the strands. These strands together form a tangential zone in the outer part of the host, which with the xylem becomes increasingly prominent, so that the surface becomes ribbed and in parts fissured by the resulting tension. Some additional examples of longitudinal strands against the host wood were also included among the specimens, as well as of tangential flange formation. Specimens of Amyema sp. increased the range of attachment structure in that genus. A. pendula had longitudinal strands against the host wood. A. gibberula in particular was noteworthy as comparable with Diplatia maideni , but with coarser strands in Grevillea striata . Longitudinal strands against the wood were also found in A. congener on Alphitonia excelsa , Acacia cunninghamii , Acacia fasciculifera , Casuarina littoralis and Geijera parviflora , but not on Acacia melanoxylon or Flindersia australis ; also, less regularly, in A. lucasii on Flindersia sp. and sometimes in A. quandang , on Acacia harpophylla and Acacia kempeana . Other specimens of A. pendula had formed them on Eucalyptus melliodora , E. propulnea , hemiphloia and haemastoma , but not on E. Stuartiana or Acacia dealbata .