Tail Plate Research Articles

Design and analysis of a rear diffuser in a sedan car

The aerodynamic characteristics have a great influence on the fuel economics and the steering stability of a high-speed vehicle. Thus, this aerodynamics is considered as one of the main ergonomics of the vehicle. Aerodynamics consists of four forces which an object or material moves. The forces are lift, drag, weight, thrust. From these four forces lift and drag plays a major role in the vehicle which runs on the road surface. To maintain steady aerodynamics various add-on devices, help in maintaining the forces that act on the vehicle. The add-on devices are spoilers, rear wing, tail plates, vortex generator, and diffuser. From these add-on devices, we take a diffuser for our project and make a design and analyze and compare it with the existing diffuser. Usually, the diffuser is first implemented in the racing field then it gradually came to use in commercial vehicles. As time moves on the people and automotive industry focuses on the efficiency of the vehicle. The main aspect to provide the best efficiency is aerodynamics. So, the add-on devices are added to the vehicle to provide the best efficiency. A modified diffuser is designed based on the aspects of the car model. By modeling these three designs using CATIA we are going to analyze them using ANSYS. In that, using CFD (Computational Fluid Dynamics) which specializes in the flow of air and water. Analyze the drag and lift coefficient based on the velocity and the different diffusers. The expected outcome of the project work is to reduce the drag and lift coefficient compared to the existing diffuser. This project deals with the design and analysis of the car model without a diffuser, with an existing diffuser, and with a modified diffuser which results in the comparison of their values.

Ontogeny and potential function of poacher armor (Actinopterygii: Agonidae).

Many vertebrates are armored over all or part of their body. The armor may serve several functional roles including defense, offense, visual display, and signal of experience/capability. Different roles imply different tradeoffs; for example, defensive armor usually trades resistance to attack for maneuverability. The poachers (Agonidae), 47 species of scorpaeniform fishes, are a useful system for understanding the evolution and function of armor due to their variety and extent of armoring. Using publically available CT-scan data from 27 species in 16 of 21 genera of poachers we compared the armor to axial skeletal in the mid body region. The ratio of average armor density to average skeleton density ranged from 0.77 to 1.17. From a defensive point of view, the total investment in mineralization (volume * average density) is more interesting. There was 10 times the material invested in the armor as in the endoskeleton in some small, smooth plated species, like Aspidophoroides olrikii. At the low end, some visually arresting species like Percis japonica, had ratios as low as 2:1. We categorized the extent and type (impact vs. abrasion) in 34 Agonopsis vulsa across all 35+ plates in the eight rows along the body. The ventral rows show abrasive damage along the entire length of the fish that gets worse with age. Impact damage to head and tail plates gets more severe and occurs at higher rates with age. The observed damage rates and the large investment in mineralization of the armor suggest that it is not just for show, but is a functional defensive structure. We cannot say what the armor is defense against, but the abrasive damage on the ventrum implies their benthic lifestyle involves rubbing on the substrate. The impact damage could result from predatory attacks or from intraspecific combat.

Optimization of bio-inspired bi-directionally corrugated panel impact-resistance structures: Numerical simulation and selective laser melting process

The telson (tail plate) of Stomatopoda (mantis shrimp) shows excellent impact resistance properties, and its special structure is an ideal prototype to mimic. In this paper, a series of bi-directionally corrugated panel (DCP) structures inspired by the telson of mantis shrimp was designed. The crush simulation of DCP structures with different structural parameters, namely wavelength (λ) and amplitude (A), was carried out using ANSYS LS-DYNA. In order to verify the simulation results, AlSi10Mg components with DCP structures were fabricated by selective laser melting and the out-of-plane compression tests were conducted to investigate the compression performance. The numerical simulation results indicated that the influence of wavelength of DCP structure on the energy absorption (EA) and specific energy absorption (SEA) capability was greater than that of the amplitude, and the DCP structure with A = 8 mm and λ = 6 mm possessed the best impact resistance performance. The SLM-processed AlSi10Mg components with DCP structures showed high surface quality and good forming accuracy, and the relation between experimental compression behavior and the DCP structure parameter was in good agreement with the numerical results.

Skin-friction topology on tail plate for tractor—trailer truck drag reduction

A simple base device called tail plate (TP) is described, which is installed behind a generic tractor—trailer truck model to reduce the pressure drag. The effect of the backward-facing step height between the top surface of the trailer and the TP on the drag reduction is studied. The drag reduction is achieved for all the tested TP configurations in a range of the Reynolds numbers. Emphasis is placed on elucidating the physical mechanism behind the drag reduction by the TP based on global luminescent oil-film (GLOF) skin-friction diagnostics. The topological structures on the TP reveal that the drag reduction results from the highly three-dimensional flow reattachment on the TP.

Research on Lightweight Optimization for Clamping Molding Tail Plate of Large Scale Die Casting Machine

In this paper the clamping moulding tail plate of a large die casting machine, which is the key component of clamping mechanism, was studied through variable density topology method based on SIMP to achieve weight reduction. Virtual prototype of the clamping mechanism was firstly developed. The actual load on the tail plate was simulated through multibody dynamic and the strength of the original structure was calculated and verified using Finite Element Analysis. Together with the consideration of actual manufacturing issues two optimization models were built up. Two topology optimizations of the models were carried out by setting optimized parameters and based on the cell density contours the final optimized structural models were designed. After the optimization, the weight was reduced by 4.42 tones with the ratio of 17.9%. Results showed that the new designs were significantly improved regarding economic and manufacturability and it is a guideline for lightweight design of other equipment.

Influence of background gas on two-dimensional metal evaporation

The spatial distributions of macroscopic parameters such as density, bulk velocity and temperature of the metal vapor have influences on the photo ionization yield of target isotope and the utilization ratio of material, which is related to the separation efficiency and the cost of atomic vapor laser isotope separation. To study this problem more practically, a system of binary gas Bhatnagar-Gross-Krook (BGK) model equations, which describe both the metal vapor and the background gas, is established. The physical characteristics are dealt with by dimensionless method for simplifying the calculations. The model equations are discretized by one-order upwind difference and then are solved by iteration method for obtaining stable results. The computational grids are adjusted to the flow field in order to acquire modest computational cost and accurate result simultaneously. Non-uniform grids in the phase space and in the velocity space are constructed to match the macroscopic parameter gradient and the form of the velocity distribution, respectively. The macroscopic parameters in the cases of different background gas densities, temperatures of tail plate and absorptivities are obtained for studying the influence of the background gas. The results show that with the increase of density of the background gas, the density and temperature of the metal vapor increase, the bulk velocities in the x and z$ direction decrease obviously in the domain far from the evaporation source, while the macroscopic parameters that are close to the evaporation source hardly change. As a result, the evaporation rate is not affected. Meanwhile, a circulation of the background gas is driven by the metal vapor, which in turn affects the diffusion of the metal vapor. Besides, as the temperature of tailing plate rises, the influence of the background gas on the macroscopic parameters of the metal vapor weakens. However, the rise of the temperature of tail plate leads the absorptivity of metal vapor to decrease, which enlarges the influence of the background gas. Therefore, it is appropriate to adjust the temperature of the tail plate based on the relationship between the absorptivity of metal vapor and the temperature. The results of theoretical calculation can serve as a reference for designing the vacuum and laser spot of the separation device.

Organ specific gene expression in the regenerating tail of Macrostomum lignano

Temporal and spatial characterization of gene expression is a prerequisite for the understanding of cell-, tissue-, and organ-differentiation. In a multifaceted approach to investigate gene expression in the tail plate of the free-living marine flatworm Macrostomum lignano, we performed a posterior-region-specific in situ hybridization screen, RNA sequencing (RNA-seq) of regenerating animals, and functional analyses of selected tail-specific genes. The in situ screen revealed transcripts expressed in the antrum, cement glands, adhesive organs, prostate glands, rhabdite glands, and other tissues. Next we used RNA-seq to characterize temporal expression in the regenerating tail plate revealing a time restricted onset of both adhesive organs and copulatory apparatus regeneration. In addition, we identified three novel previously unannotated genes solely expressed in the regenerating stylet. RNA interference showed that these genes are required for the formation of not only the stylet but the whole male copulatory apparatus. RNAi treated animals lacked the stylet, vesicula granulorum, seminal vesicle, false seminal vesicle, and prostate glands, while the other tissues of the tail plate, such as adhesive organs regenerated normally. In summary, our findings provide a large resource of expression data during homeostasis and regeneration of the morphologically complex tail regeneration and pave the way for a better understanding of organogenesis in M. lignano.

Adhesive organ regeneration in Macrostomum lignano.

BackgroundFlatworms possess pluripotent stem cells that can give rise to all cell types, which allows them to restore lost body parts after injury or amputation. This makes flatworms excellent model systems for studying regeneration. In this study, we present the adhesive organs of a marine flatworm as a simple model system for organ regeneration. Macrostomum lignano has approximately 130 adhesive organs at the ventral side of its tail plate. One adhesive organ consists of three interacting cells: one adhesive gland cell, one releasing gland cell, and one modified epidermal cell, called an anchor cell. However, no specific markers for these cell types were available to study the regeneration of adhesive organs.ResultsWe tested 15 commercially available lectins for their ability to label adhesive organs and found one lectin (peanut agglutinin) to be specific to adhesive gland cells. We visualized the morphology of regenerating adhesive organs using lectin- and antibody staining as well as transmission electron microscopy. Our findings indicate that the two gland cells differentiate earlier than the connected anchor cells. Using EdU/lectin staining of partially amputated adhesive organs, we showed that their regeneration can proceed in two ways. First, adhesive gland cell bodies are able to survive partial amputation and reconnect with newly formed anchor cells. Second, adhesive gland cell bodies are cleared away, and the entire adhesive organ is build anew.ConclusionOur results provide the first insights into adhesive organ regeneration and describe ten new markers for differentiated cells and tissues in M. lignano. The position of adhesive organ cells within the blastema and their chronological differentiation have been shown for the first time. M. lignano can regenerate adhesive organs de novo but also replace individual anchor cells in an injured organ. Our findings contribute to a better understanding of organogenesis in flatworms and enable further molecular investigations of cell-fate decisions during regeneration.Electronic supplementary materialThe online version of this article (doi:10.1186/s12861-016-0121-1) contains supplementary material, which is available to authorized users.

Cellular dynamics during regeneration of the flatworm Monocelis sp. (Proseriata, Platyhelminthes).

BackgroundProseriates (Proseriata, Platyhelminthes) are free-living, mostly marine, flatworms measuring at most a few millimetres. In common with many flatworms, they are known to be capable of regeneration; however, few studies have been done on the details of regeneration in proseriates, and none cover cellular dynamics. We have tested the regeneration capacity of the proseriate Monocelis sp. by pre-pharyngeal amputation and provide the first comprehensive picture of the F-actin musculature, serotonergic nervous system and proliferating cells (S-phase in pulse and pulse-chase experiments and mitoses) in control animals and in regenerates.ResultsF-actin staining revealed a strong body wall, pharynx and dorsoventral musculature, while labelling of the serotonergic nervous system showed an orthogonal pattern and a well developed subepidermal plexus. Proliferating cells were distributed in two broad lateral bands along the anteroposterior axis and their anterior extension was delimited by the brain. No proliferating cells were detected in the pharynx or epidermis.Monocelis sp. was able to regenerate the pharynx and adhesive organs at the tip of the tail plate within 2 or 3 days of amputation, and genital organs within 8 to 10 days. Posterior pieces were not able to regenerate a head.The posterior regeneration blastema was found to be a centre of cell proliferation, whereas within the pharynx primordium, little or no proliferation was detected. The pharynx regenerated outside of the blastema and was largely, but not solely formed by cells that were proliferating at the time of amputation.ConclusionsOur findings suggest that proliferating cells or their offspring migrated to the place of organ differentiation and then stopped proliferating at that site. This mode of rebuilding organs resembles the mode of regeneration of the genital organs in another flatworm, Macrostomum lignano. Pharynx regeneration resembles embryonic development in Monocelis fusca and hints at the vertically directed pharynx being plesiomorphic in proseriates.Proliferation within the regeneration blastema has been detected in anterior and posterior blastemas of other flatworms, but is notably missing in triclads. The phylogenetic relationships of the flatworms studied indicate that proliferation within the blastema is the plesiomorphic condition in Platyhelminthes.Electronic supplementary materialThe online version of this article (doi:10.1186/2041-9139-5-37) contains supplementary material, which is available to authorized users.

Drag Reduction of Passenger Car Using Add-On Devices

This work proposes an effective numerical model using the Computational Fluid Dynamics (CFD) to obtain the flow structure around a passenger car with different add-on devices. The computational/numerical model of the passenger car and mesh was constructed using ANSYS Fluent which is the CFD solver and employed in the present work. In this study, numerical iterations are completed, and then aerodynamic data and detailed complicated flow structure are visualized. In the present work, a model of generic passenger car was developed using solidworks, generated the wind tunnel, and applied the boundary conditions in ANSYS workbench platform, and then testing and simulation have been performed for the evaluation of drag coefficient for passenger car. In another case, the aerodynamics of the most suitable design of vortex generator, spoiler, tail plates, and spoiler with VGs are introduced and analysed for the evaluation of drag coefficient for passenger car. The addition of these add-on devices are reduces the drag-coefficient and lift coefficient in head-on wind. Rounding the edges partially reduces drag in head-on wind but does not bring about the significant improvements in the aerodynamic efficiency of the passenger car with add-on devices, and it can be obtained. Hence, the drag force can be reduced by using add-on devices on vehicle and fuel economy, stability of a passenger car can be improved.

Biological adhesion of the flatworm Macrostomum lignano relies on a duo-gland system and is mediated by a cell type-specific intermediate filament protein

BackgroundFree-living flatworms, in both marine and freshwater environments, are able to adhere to and release from a substrate several times within a second. This reversible adhesion relies on adhesive organs comprised of three cell types: an adhesive gland cell, a releasing gland cell, and an anchor cell, which is a modified epidermal cell responsible for structural support. However, nothing is currently known about the molecules that are involved in this adhesion process.ResultsIn this study we present the detailed morphology of the adhesive organs of the free-living marine flatworm Macrostomum lignano. About 130 adhesive organs are located in a horse-shoe-shaped arc along the ventral side of the tail plate. Each organ consists of exactly three cells, an adhesive gland cell, a releasing gland cell, and an anchor cell. The necks of the two gland cells penetrate the anchor cell through a common pore. Modified microvilli of the anchor cell form a collar surrounding the necks of the adhesive- and releasing glands, jointly forming the papilla, the outer visible part of the adhesive organs. Next, we identified an intermediate filament (IF) gene, macif1, which is expressed in the anchor cells. RNA interference mediated knock-down resulted in the first experimentally induced non-adhesion phenotype in any marine animal. Specifically, the absence of intermediate filaments in the anchor cells led to papillae with open tips, a reduction of the cytoskeleton network, a decline in hemidesmosomal connections, and to shortened microvilli containing less actin.ConclusionOur findings reveal an elaborate biological adhesion system in a free-living flatworm, which permits impressively rapid temporary adhesion-release performance in the marine environment. We demonstrate that the structural integrity of the supportive cell, the anchor cell, is essential for this adhesion process: the knock-down of the anchor cell-specific intermediate filament gene resulted in the inability of the animals to adhere. The RNAi mediated changes of the anchor cell morphology are comparable to situations observed in human gut epithelia. Therefore, our current findings and future investigations using this powerful flatworm model system might contribute to a better understanding of the function of intermediate filaments and their associated human diseases.

CFD Simulation for Flow over Passenger Car Using Tail Plates for Aerodynamic Drag Reduction

This work proposes an effective numerical model based on the Computational Fluid Dynamics (CFD) approach to obtain the flow structure around a passenger car with Tail Plates. The experimental work of the test vehicle and grid system is constructed by ANSYS-14.0. FLUENT which is the CFD solver & employed in the present work. In this study, numerical iterations are completed, then after aerodynamic data and detailed complicated flow structure are visualized. In the present work, model of generic passenger car has been developed in solid works-10 and generated the wind tunnel and applied the boundary conditions in ANSYS workbench 14.0 platform then after testing and simulation has been performed for the evaluation of drag coefficient for passenger car. In another case, the aerodynamics of the most suitable design of tail plate is introduced and analysedfor the evaluation of drag coefficient for passenger car. The addition of tail plates results in a reduction of the drag-coefficient 3.87% and lift coefficient 16.62% in head-on wind. Rounding the edges partially reduces drag in head-on wind but does not bring about the significant improvements in the aerodynamic efficiency of the passenger car with tail plates, it can be obtained. Hence, the drag force can be reduced by using add on devices on vehicle and fuel economy, stability of a passenger car can be improved.

Frequent Anomalies in Larvae of Common and Moor Frogs in Moscow area and in the Suburbs of Moscow, Russia

We studied influence of anthropogenic pollution of spawning ponds on embryogenesis of the common and the moor frogs ( Rana temporaria Linnaeus 1758, and Rana arvalis Nilsson 1852) from the natural population of the urban and the suburban territories of Moscow. Counts of larvae with anomalies in samples, fixed at different stages, indicated that in Moscow city and in the suburban territory the anomalies occur with approximately equal frequency. Spinal curvature, bradygenesis and skin damage were the most common anomalies. Edema (hydropsy), anomalies in gills, pigmentation disorders and complete malformation were also observed. In both species at all sites, most of the larvae had only one kind of anomaly, but some of them had two or more. Morphometric analysis of the spinal curvature showed that in abnormal tadpoles the angle between the body planes and tail plates was significantly less than in normal tadpoles, and is observed the underdevelopment of the tail. This anomaly is lethal because such embryos are not able to swim normally at later stages of development. Histological studies showed that the causes of spinal curvature in dorso-ventral direction is usually caused by somitogenesis defects or incomplete rotation of somites. Differences between species were observed in frequency of the less common anomalies. For Rana temporaria , edema, as well as a combination of complete malformation and skin defects were typical, while for Rana arvalis — a combination of edema and slow time of development was most common. No significant differences in frequency and nature of the anomalies were found between these species. However, inter-annual variability was remarkable. This suggests that frequency of occurrence of anomalies depends on the annual environmental situation.

Proliferative response of the stem cell system during regeneration of the rostrum in Macrostomum lignano (Platyhelminthes)

Macrostomum lignano (Platyhelminthes) possesses pluripotent stem cells, also called neoblasts, which power its extraordinary regeneration capacity. We have examined the cellular dynamics of neoblasts during regeneration of the rostrum in M. lignano. First, using live squeeze observations, the growth curve of the rostrum was determined. Second, neoblasts were labelled with 5-bromo-2'-deoxyuridine (BrdU) and an anti-phospho-histone H3 mitosis marker (anti-phos-H3) to analyze their proliferative response to amputation. During the regeneration process, both S- and M-phase cells were present anterior to the eyes, a region that is devoid of proliferating cells during homeostasis. Furthermore, BrdU pulse experiments revealed a biphasic S-phase pattern, different from the pattern known to occur during regeneration of the tail plate in M. lignano. During a first systemic phase, S-phase numbers significantly increased, both in the region adjacent to the wound (the anterior segment) and the region far from the wound (the posterior segment). During the second, spatially restricted phase, S-phase numbers in the anterior segment rose to a peak at 3 to 5 days post-amputation (p-a), while in the posterior segment, S-phase activity approached control values again. A blastema, characterized as a build-up of S- and M-phase cells, was formed 1 day p-a. Altogether, our data present new insights into the cellular response of the neoblast system upon amputation, clearly demonstrating important differences from the situation known to occur during regeneration of the tail plate. Furthermore, the presence of proliferating cells in the region anterior to the eyes shows a clear alteration in stem cell regulation during regeneration.

The caudal regeneration blastema is an accumulation of rapidly proliferating stem cells in the flatworm Macrostomum lignano

BackgroundMacrostomum lignano is a small free-living flatworm capable of regenerating all body parts posterior of the pharynx and anterior to the brain. We quantified the cellular composition of the caudal-most body region, the tail plate, and investigated regeneration of the tail plate in vivo and in semithin sections labeled with bromodeoxyuridine, a marker for stem cells (neoblasts) in S-phase.ResultsThe tail plate accomodates the male genital apparatus and consists of about 3,100 cells, about half of which are epidermal cells. A distinct regeneration blastema, characterized by a local accumulation of rapidly proliferating neoblasts and consisting of about 420 cells (excluding epidermal cells), was formed 24 hours after amputation. Differentiated cells in the blastema were observed two days after amputation (with about 920 blastema cells), while the male genital apparatus required four to five days for full differentiation. At all time points, mitoses were found within the blastema. At the place of organ differentiation, neoblasts did not replicate or divide. After three days, the blastema was made of about 1420 cells and gradually transformed into organ primordia, while the proliferation rate decreased. The cell number of the tail plate, including about 960 epidermal cells, was restored to 75% at this time point.ConclusionRegeneration after artificial amputation of the tail plate of adult specimens of Macrostomum lignano involves wound healing and the formation of a regeneration blastema. Neoblasts undergo extensive proliferation within the blastema. Proliferation patterns of S-phase neoblasts indicate that neoblasts are either determined to follow a specific cell fate not before, but after going through S-phase, or that they can be redetermined after S-phase. In pulse-chase experiments, dispersed distribution of label suggests that S-phase labeled progenitor cells of the male genital apparatus undergo further proliferation before differentiation, in contrast to progenitor cells of epidermal cells. Mitotic activity and proliferation within the blastema is a feature of M. lignano shared with many other regenerating animals.

Thraustochytrids as novel parasitic protists of marine free-living flatworms: Thraustochytrium caudivorum sp. nov. parasitizes Macrostomum lignano

The Labyrinthulomycota are a relatively poorly studied group of heterotrophic unicellular eukaryotes. They comprise three lineages, labyrinthulids, thraustochytrids, and aplanochytrids, which are all primarily marine organisms and considered to be important components of marine microbial communities. Recently a number of Labyrinthulomycota have been implicated as parasites of marine (but also terrestrial) plants and marine molluscs. Here we describe a new species of thraustochytrid, Thraustochytrium caudivorum sp. nov. that we have isolated from laboratory cultures of Macrostomum lignano (Rhabditophora, Macrostomorpha), a marine free-living flatworm. In these worms T. caudivorum can cause lesions, which start at the tip of the tail plate and which can lead to the dissolution of the posterior part of the animal. Although the worms can frequently cure these lesions and regenerate the lost parts, the lesions can also result in the complete dissolution of the animal. We describe this thraustochytrid based on pure agar cultures and infestations in the worm cultures. Moreover, we describe its pathological effects on the worms and its morphology using both light and electron microscopy. In addition, we report a phylogenetic analysis using a partial 18S rDNA sequence that allows us to place this new species within the thraustochytrids. Finally, we outline a protocol that allows to permanently remove the parasites from infested worm cultures. We conclude that thraustochytrids represent a novel group of parasites of free-living flatworms.

ECHINOCHITON DUFOEI: A NEW SPINY ORDOVICIAN CHITON

Abstract Echinochiton dufoei new genus and species is described from the Ordovician age Forreston Member, Grand Detour Formation (Blackriveran) near Beloit, Wisconsin. For a variety of reasons, we regard E. dufoei as a chiton; the species is known from four articulated or partially articulated specimens, one of which has eight plates and two of which have a mucro on the tail plate. Echinochiton dufoei differs from other chitons in having large hollow spines that project from each of the known plates. In plate shape and position, E. dufoei is much like the Upper Cambrian species Matthevia variabilis Walcott, 1885, and the Lower Ordovician species Chelodes whitehousei Runnegar, Pojeta, Taylor, and Collins (1979).

Echinochiton dufoei: A New Spiny Ordovician chiton

Echinochiton dufoei new genus and species is described from the Ordovician age Forreston Member, Grand Detour Formation (Blackriveran) near Beloit, Wisconsin. For a variety of reasons, we regard E. dufoei as a chiton; the species is known from four articulated or partially articulated specimens, one of which has eight plates and two of which have a mucro on the tail plate. Echinochiton dufoei differs from other chitons in having large hollow spines that project from each of the known plates. In plate shape and position, E. dufoei is much like the Upper Cambrian species Matthevia variabilis Walcott, 1885, and the Lower Ordovician species Chelodes whitehousei Runnegar, Pojeta, Taylor, and Collins (1979).

A new approach in free air ball formation process parameters analysis

The shape and size of gold wire ball formation deeply affects the quality of wire bonding. It not only affects the bond-ability of the first bond (ball bond), but also affects the possibility of processing low loop height bonding for thin packaging [such as thin small outline package (TSOP) and thin quad flat package (TQFP)] and high input/output (I/O) fine pitch packaging such as ball grid array. The parameters which affect the gold wire ball formation include: 1) tail length left after second bond; 2) type and shape of capillaries used; 3) material characteristics of gold wire; 4) supplied voltage, current, and time of electrical flame-off (EFO) unit; 5) gap between tail and electrode plate; and 6) relative position between capillary and electrode plate. In this paper, experiments were conducted to find the effect of these parameters on ball formation. Taguchi method together with neural network is applied in this research to find the best parameters setting for gold wire ball formation. It can then be used for wire bonding process parameter adjustment and process monitoring. It can also be used as reference for the development of wire bonders.

Structure and function of a novel coliphage-associated sialidase

A coliphage named 63D, isolated previously, associated sialidase as a component of phage particles. In order to localize the enzyme in phage particles, phages were partially destroyed by sonication, and the disrupted particles were size fractionated using a sucrose density gradient. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis, enzyme assay and electron micrography of the fractions revealed the enzyme to be composed of four identical subunits with a molecular mass of 90 kDa, and the subunits were cross-linked by disulfide bonds. Electron micrographic observation indicated that six enzyme molecules were localized in a phage tail plate as a hexagonal array.