Angel Wing Research Articles

Design of an Improved Turbine Rim-Seal

Rim seals are fitted in gas turbines at the periphery of the wheel-space formed between rotor disks and their adjacent casings. These seals, also called platform overlap seals, reduce the ingress of hot gases which can limit the life of highly stressed components in the engine. This paper describes the development of a new, patented rim-seal concept showing improved performance relative to a reference engine design, using unsteady Reynolds-averaged Navier–Stokes (URANS) computations of a turbine stage at engine conditions. The computational fluid dynamics (CFD) study was limited to a small number of purge-flow rates due to computational time and cost, and the computations were validated experimentally at a lower rotational Reynolds number and in conditions under incompressible flow. The new rim seal features a stator-side angel wing and two buffer cavities between outer and inner seals: the angel-wing promotes a counter-rotating vortex to reduce the effect of the ingress on the stator; the two buffer cavities are shown to attenuate the circumferential pressure asymmetries of the fluid ingested from the mainstream annulus. Rotor disk pumping is exploited to reduce the sealing flow rate required to prevent ingress, with the rotor boundary layer also providing protective cooling. Measurements of gas concentration and swirl ratio, determined from static and total pressure, were used to assess the performance of the new seal concept relative to a benchmark generic seal. The radial variation of concentration through the seal was measured in the experiments and these data captured the improvements due to the intermediate buffer cavities predicted by the CFD. This successful design approach is a potent combination of insight provided by computation, and the flexibility and expedience provided by experiment.

Low-cost solid catalyst derived from waste Cyrtopleura costata (Angel Wing Shell) for biodiesel production using microalgae oil

In the present work, Cyrtopleura costata (Angel Wing Shell) is used for the first time to synthesis of CaO. The produced CaO was utilized as a catalyst for biodiesel production from microalgae Nannochloropsis oculata oil. The Angel Wing Shell (AWS) was calcined at 800°C and 900°C for 2h to convert CaCO3 to activate metal oxide phase. The synthesized catalysts were characterized by using Thermogravimetric analysis (TGA), X-ray diffraction (XRD), Temperature programmed desorption of CO2 (CO2-TPD), BET surface area and Scanning electron microscopy (SEM) analysis. The calcined Angel Wing Shell at 900°C (CAWS 900) was chosen as the best catalyst due to its high basicity and surface area. This also corresponded to optimization condition where, CAWS 900 showed highest FAME yield (84.11%) at oil to methanol molar ratio 1:150 and catalyst loading of 9wt.% in 1h reaction time. The CAWS 900 catalyst also can be reused more than three times with FAME yield greater than 65%. Overall, AWS appears to be an acceptable solid catalyst to convert microalgae oil to biodiesel.

Angel's wing appearance on chest radiograph – progressive massive fibrosis

A 55-year-old male presented with progressive dyspnoea for five years. He had worked in the marble industry for the past 20 years and was a stone crusher. Chest radiograph revealed bilateral radiodense masses in a parahilar location (Fig [1][1]). On CT, the soft tissue masses were of high

Vulvar and vaginal reconstruction using the “angel wing” perforator-based island flap

ObjectiveVulvar and vaginal reconstruction can be challenging for the reconstructive surgeon. The reconstructive goal is to provide wound healing, adequate function, and acceptable appearance. In the present study, we introduce a new design called the “angel wing” flap, which is a modification of a transposition flap and is based on the perforator concept for vulvar and vaginal reconstruction. MethodsFrom January 2002 to December 2013, 23 women underwent reconstruction of vulvar and vaginal defects. Causative factors were vulvar cancer in 14 patients, extramammary Paget's disease in 2, vulvar dysplasia in 5, and combined vulvar and vaginal cancer in 2 patients. ResultsA total of 41 flaps were applied. All patients underwent surgical reconstruction in a single step using the “angel wing” flap. Flap size ranged from 4×7 to 13×6cm2 and the operative duration for reconstructive surgery ranged from 30 to 100min. All the flaps survived with good coverage of the defect. Mean follow-up time after the procedure was 16.1months (range, 6–30months). ConclusionIn this article, we introduce a simple and easy reconstructive procedure of the “angel wing” flap. For restoring function, as well as for esthetic purposes, the flap was designed in accordance with the defect since the natural contour of the vulva and vagina is three-dimensional.

A-WINGS: an integrated genome database for Pleurocybella porrigens (Angel's wing oyster mushroom, Sugihiratake).

BackgroundThe angel’s wing oyster mushroom (Pleurocybella porrigens, Sugihiratake) is a well-known delicacy. However, its potential risk in acute encephalopathy was recently revealed by a food poisoning incident. To disclose the genes underlying the accident and provide mechanistic insight, we seek to develop an information infrastructure containing omics data. In our previous work, we sequenced the genome and transcriptome using next-generation sequencing techniques. The next step in achieving our goal is to develop a web database to facilitate the efficient mining of large-scale omics data and identification of genes specifically expressed in the mushroom.FindingsThis paper introduces a web database A-WINGS (http://bioinf.mind.meiji.ac.jp/a-wings/) that provides integrated genomic and transcriptomic information for the angel’s wing oyster mushroom. The database contains structure and functional annotations of transcripts and gene expressions. Functional annotations contain information on homologous sequences from NCBI nr and UniProt, Gene Ontology, and KEGG Orthology. Digital gene expression profiles were derived from RNA sequencing (RNA-seq) analysis in the fruiting bodies and mycelia. The omics information stored in the database is freely accessible through interactive and graphical interfaces by search functions that include ‘GO TREE VIEW’ browsing, keyword searches, and BLAST searches.ConclusionsThe A-WINGS database will accelerate omics studies on specific aspects of the angel’s wing oyster mushroom and the family Tricholomataceae.

Time-Averaged and Time-Accurate Aerodynamic Effects of Forward Rotor Cavity Purge Flow for a High-Pressure Turbine—Part I: Analytical and Experimental Comparisons

The effect of rotor purge flow on the unsteady aerodynamics of a high-pressure turbine stage operating at design corrected conditions has been investigated, both experimentally and computationally. The experimental configuration consisted of a single-stage high-pressure turbine with a modern film-cooling configuration on the vane airfoil and the inner and outer end wall surfaces. Purge flow was introduced into the cavity located between the high-pressure vane and the high-pressure disk. The high-pressure blades and the downstream low-pressure turbine nozzle row were not cooled. All of the hardware featured an aerodynamic design typical of a commercial high-pressure ratio turbine and the flow path geometry was representative of the actual engine hardware. In addition to instrumentation in the main flow path, the stationary and rotating seals of the purge flow cavity were instrumented with high frequency response flush-mounted pressure transducers and miniature thermocouples in order to measure the flow field parameters above and below the angel wing. Predictions of the time-dependent flow field in the turbine flow path were obtained using FINE/Turbo, a three-dimensional Reynolds-averaged Navier–Stokes computational fluid dynamics CFD code that had the capability to perform both a steady and unsteady analysis. The steady and unsteady flow fields throughout the turbine were predicted using a three blade-row computational model that incorporated the purge flow cavity between the high-pressure vane and disk. The predictions were performed in an effort to mimic the design process with no adjustment of boundary conditions to better match the experimental data. The time-accurate predictions were generated using the harmonic method. Part I of this paper concentrates on the comparison of the time-averaged and time-accurate predictions with measurements in and around the purge flow cavity. The degree of agreement between the measured and predicted parameters is described in detail, providing confidence in the predictions for the flow field analysis that will be provided in Part II.

Time-Averaged and Time-Accurate Aerodynamic Effects of Rotor Purge Flow for a Modern, One and One-Half Stage High-Pressure Turbine—Part II: Analytical Flow Field Analysis

The detailed mechanisms of purge flow interaction with the hot-gas flow path were investigated using both unsteady computationally fluid dynamics (CFD) and measurements for a turbine operating at design corrected conditions. This turbine consisted of a single-stage high-pressure turbine and the downstream, low-pressure turbine nozzle row with an aerodynamic design equivalent to actual engine hardware and typical of a commercial, high-pressure ratio, transonic turbine. The high-pressure vane airfoils and inner and outer end walls incorporated state-of-the-art film cooling, and purge flow was introduced into the cavity located between the high-pressure vane and disk. The flow field above and below the blade angel wing was characterized by both temperature and pressure measurements. Predictions of the time-dependent flow field were obtained using a three-dimensional, Reynolds-averaged Navier–Stokes CFD code and a computational model incorporating the three blade rows and the purge flow cavity. The predictions were performed to evaluate the accuracy obtained by a design style application of the code, and no adjustment of boundary conditions was made to better match the experimental data. Part I of this paper compared the predictions to the measurements in and around the purge flow cavity and demonstrated good correlation. Part II of this paper concentrates on the analytical results, looking at the primary gas path ingestion mechanism into the cavity as well as the effects of the rotor purge on the upstream vane and downstream rotor aerodynamics and thermodynamics. Ingestion into the cavity is driven by high static pressure regions downstream of the vane, high-velocity flow coming off the pressure side of the vane, and the blade bow waves. The introduction of the purge flow is seen to have an effect on the static pressure of the vane trailing edge in the lower 5% of span. In addition, the purge flow is weak enough that upon exiting the cavity, it is swept into the mainstream flow and provides no additional cooling benefits on the platform of the rotating blade.

The Effects of a Parametric Variation of the Rim Seal Geometry on the Interaction Between Hub Leakage and Mainstream Flows in High Pressure Turbines

The objective of this work was to assess and understand the effects of a parametric variation performed on a typical overlapping rim seal geometry. The datum geometry has been the focus of a detailed experimental investigation employing a large-scale linear cascade subjected to a range of the mass flow rates and swirl velocities of the leakage air. The parametric variations described in this paper were examined using validated computational fluid dynamics (CFD). As a part of the parametric studies, both the axial and the radial seal clearance between the rotor fin (angel wing) and stator platform were varied as well as the length of the overlap between stator and rotor platforms. In addition, the effects of forward and backward facing annulus steps were also investigated. It has been found that a backward-facing annulus step was detrimental for all conditions considered, while a forward-facing step offered improvements for smaller step heights and/or lower leakage fractions. Tightening of the seal clearances closer to the annulus line improved the sealing effectiveness but often at the expense of increased losses. On the other hand, increasing the overlap length led to improvements in the sealing effectiveness with very small effects on the overall losses. Moving the rim seal away from the blade-leading edges reduced the pressure asymmetry at the rim seal and increased the flow uniformity of the leakage air. However, this led to an increased cross-passage flow (more negative skew) and higher losses at all but lowest leakage fractions. The results presented in this paper highlight the fact that there may not be an optimum rim seal solution that would offer an improvement for the full range of leakage fractions and that, for different rim sealing flows, there may be a different optimum geometry. In addition, rotor disk movements in radial and axial directions at various off-design conditions should be considered as a part of the design process. Based on the presented results, it may be of a benefit to the turbine designer to consider rotor disk designs that would be more biased towards the upstream and outward disk movements, which would result in tightening of the seal clearances and avoidance of a backward-facing annulus step.

Angel Wing Sign in a Neonate with Pneumomediastinum

Angel Wing Sign in a Neonate with Pneumomediastinum

Incidence of Wing Deformities (‘Angel Wing’) Among Masked Boobies at Clipperton Island: Life History Consequences and Insight into Etiology

Abstract ‘Angel wing’ is a developmental wing deformity among birds that can cause flightlessness; it is mostly known from domestic birds, especially waterfowl, and has only rarely been reported among wild bird populations. We estimated that 460 (4.4%) Masked Booby (Sula dactylatra) chicks on Clipperton Island (10° 18′ N, 109° 13′ W) in the eastern tropical Pacific Ocean exhibited angel wing during March 2005. Both hatching-year birds and after-hatching-year birds exhibited the condition; the latter included seven flightless birds in adult plumage (i.e., minimum 2 yrs of age) which were still being fed by their presumed parents. The angel wing outbreak coincided in time with high nestling mortality, apparently related to food shortage, and we speculate on causal linkages.

Aerodynamics and Heat Transfer for a Cooled One and One-Half Stage High-Pressure Turbine–Part II: Influence of Inlet Temperature Profile on Blade Row and Shroud

Heat flux measurements are presented for the uncooled blades of a one and one-half stage turbine operating at design corrected conditions with a fully cooled upstream vane row and with rotor disk cavity purge flow. This paper highlights the differences in blade heat flux and temperature caused by uniform, radial, and hot streak inlet temperature profiles. A general discussion of temperature profile migration is provided in Part I, and Part III presents data for hot streak magnitudes and alignments. The heat flux and fluid temperature measurements for the blade airfoil, platform, angel wing (near the root), and tip as well as for the stationary outer shroud are influenced by the vane inlet temperature profile. The inlet temperature profile shape can be clearly observed in the blade Stanton number measurements, with the radial and hot streak profiles showing a greater redistribution of energy than the uniform case due to secondary flows. Hot-gas segregation is observed to increase with the strength of the temperature distortion. Measurements for the hot streak profile show a segregation of higher temperature fluid to the pressure surface when compared with a uniform profile. The introduction of vane and purge cooling is found to further accentuate the flow segregation due to coolant migration to the suction surface.

Feasting on Famine in Linda Hogan’s <i>Solar Storms</i>

In 1899 H. B. Cushman observed that when a Chickasaw died, tribal lamentations would last for several days and would con clude with a feast (410). Nearly one hundred years later in 1997, in the prologue to her novel Solar Storms, Chickasaw Linda Hogan recounts a feast.1 But in her presentation, Hogan changes several mourning-feast customs, the most salient of which requires that the mourned be deceased. The alteration of the tradi tional mourning feast serves not merely as a signpost for changing Native American rituals. Rather, the transformed mourning feast in Solar Storms indicts white culture for causing Native American famine, both physical and emotional. But in blurring some demar cations of culpability and in providing a role model in the form of the character offering the feast, Hogan points to ways in which the Native American community might respond to the emotional, bodily, and cultural starvation inflicted through postcolonialism.2 In this manner Hogan eschews what David L. Moore deems con struction of reductionist binaries concerning colonization.3 Hogan's Solar Storms recounts the story of Angela (Angel) Wing, a beleaguered seventeen-year-old whose disfigured face bears the scars of an unremembered trauma. Angela's deranged mother Hannah Wing necessitated Angela's placement in foster homes, from which Angela has fled for years. In a court record Angela dis covers the name of Agnes Iron, whom she contacts, believing her to be a relative. Agnes, Angela's great-grandmother, immediately sends money for Angela to join her in Adam's Rib, an economically

Experimental Precipitation of Barite (BaSO4) Among Streamers of Sulfur-Oxidizing Bacteria

Abstract Barite precipitation was induced by mixing sulfate and barium solutions to investigate conditions under which barite is most likely to be localized on microbial substrates, and hence most likely to preserve biogenic textures. Addition of sulfate solution to barium solution resulted in precipitation of intergrown platy, dendritic angel wing, and microgranular barite in solution. Bacterial streamers and extracellular polymeric substances (EPS) collected from a cold sulfur spring acted as loci for precipitation of euhedral bowtie, intergrown platy, and intergrown tabular barite crystals, and scalloped platy barite crystals when sulfate solution was added to barium solutions in which they were immersed. Desiccation of bacterial streamers previously exposed to barium solution also produced subhedral platy and elongate anhedral barite crystals on extracellular surfaces and EPS. Immersion of barium-exposed streamers in sulfate solution produced scalloped platy barite crystals distributed through EPS and forming radial strings around bacterial filaments. Accidental exposure of streamers to iron produced amorphous iron oxides, as well as novel single and intergrown mixed-oxygenation-state barite/FeS sandwiches. Distinct barite crystal habits and textures were observed in experiments conducted with and without bacterial streamers, suggesting that microbes have potential to influence the petrography of barite precipitated in sulfate-limited microbially colonized environments.

Acute encephalopathy associated with ingestion of a mushroom, Pleurocybella porrigens (angel's wing), in a patient with chronic renal failure

The authors report an autopsy case of acute encephalopathy in which generalized convulsion and coma occurred after ingestion of Pleurocybella porrigens (angel's wing mushroom). The patient was a 65-year-old man who had undergone hemodialysis for 3 months due to chronic renal failure. Pathologic examination of the brain revealed extensive postinfarction-like cystic necrosis in the bilateral putamens and multiple spotty necroses in the deep cerebral and cerebellar cortices. In 2004, similar acute encephalopathy related to ingestion of the mushroom was endemic in Japan, the pathogenesis of which remains to be elucidated.

Bilateral Valgus Deformity of the Distal Wings (Angel Wing) in a Northern Goshawk (Accipiter gentilis)

Abstract A 4-week-old female Northern goshawk (Accipiter gentilis) presented with a valgus deformity of both wings resulting in dorsolateral rotation of the primary flight feathers. The condition resolved in 2 weeks after the wings were bandaged and physical therapy was performed. This type of valgus deformity is also known as angel wing. It has been frequently described in waterfowl and has been reported in bustard chicks as well as psittacine birds (budgerigars, macaws, and conures). To the best of the authors' knowledge, this is the first report in a peer-reviewed publication describing angel wing and its treatment in a raptor.

Sugihiratake Mushroom (Angel's Wing Mushroom)-Induced Cryptogenic Encephalopathy may Involve Vitamin D Analogues

In autumn 2004, many Japanese patients with renal failure developed cryptogenic encephalopathy by consuming sugihiratake mushroom, a Japanese delicacy. To elucidate the relationship between the cryptogenic cases and this mushroom, we conducted a multivariate analysis of metabolites in 'Probably Toxic' sugihiratake collected from the area of encephalopathy outbreaks, and 'Probably Safe' sugihiratake collected from unaffected areas using UPLC/ToF MS. The results indicate that the presence of milligram quantities of vitamin D-like compounds per 10 g of dried sugihiratake from the areas of encephalopathy outbreaks. Two hypotheses to induce the encephalopathy are proposed: the found metabolites are (1) vitamin D agonists, which induce acute and severe hypercalcemia and/or hyperammonemia and/or vitamin D toxicity, or (2) vitamin D antagonists, which induce acute and severe hypocalcemia.

MRT-Sicherheitsaspekte und -Artefakte von Vorhofseptum-Okkludersystemen bei 1,5 Tesla: eine Phantomstudie

To investigate the magnetic resonance safety and magnetic resonance artifact intensities of patent foramen ovale and atrial septal occluders in a phantom study. Seven different commercial occluder models (Amplatzer ASD, Angel Wing ASD, Helex Septal Occluder, Cardia PFO-Star Generation I & III, Sideris Buttoned Device, Starflex ASD) were tested in a 1.5 Tesla whole-body MR scanner. Following a deflection test, the non-magnetic devices were imaged using different MRI pulse sequences including conventional spin echo, spoiled gradient echo as well as fast refocused steady-state pulse sequences (trueFISP) commonly used for cardiac MRI. Additionally, device temperatures were measured in the MR scanner during two imaging protocols (trueFISP, HASTE) with an MR-compatible fiber-optical thermometer. One ferromagnetic device (Sideris Buttoned Device) did not pass the deflection test and was excluded from further experiments. For typical cardiac imaging protocols, the remaining non-ferromagnetic devices showed only minor image artifacts with artifact sizes not exceeding 2 mm next to a strut. Heating was not observed in the devices. Non-ferromagnetic occluder models used in this study can safely be imaged with typical cardiac MRI protocols at 1.5 Tesla. The device artifact sizes are small enough to allow anatomical and functional MRI even in the immediate vicinity of the occluders.

Origin of platy calcite crystals in hot-spring deposits in the Kenya Rift valley

ABSTRACT Platy calcite crystals, which have their c axis parallel to their shortest length axis, are common components of travertine deposits found around some hot springs in the Kenya Rift Valley. They are composite formed of numerous paper-thin subcrystals. Individual plates allowed to grow without obstruction develop a hexagonal motif. The Kenyan typically form in hot (> 75°C) waters that have a low Ca content (-1), a high CO2 content, and a high rate of CO2 degassing. At Chemurkeu, aggregates of numerous small platy collectively form crystals that superficially resemble ray The walls of the lattice are formed of large platy that have their long and intermediate length axes aligned parallel to the plane of the long axis of the lattice crystal. Internally, the lattice are formed of small platy calcite arranged in a box-like pattern that creates the appearance of a lattice when viewed in thin section. Lattice are highly porous, with each pore being enclosed by platy crystals. At Lorusio, travertines are mainly formed of that are constructed by numerous small platy attached to a main stem which is a large platy crystal that commonly curves along its long axis. The pseudodentrites are the main construction blocks in ledges and lilypads that form in the vent pool and spring outflow channels, where the water is too hot for microbes other than hyperthermophiles. The platy calcite in the Kenyan travertines are morphologically similar to platy calcite that form as scale in pipes in the geothermal fields of New Zealand and hydrothermal angel wing calcite from the La Fe mine in Mexico. Comparison of the Kenyan and New Zealand indicates that platy calcite form from waters with a low Ca2+ content and a high CO3/Ca ratio due to rapid rates of CO2 degassing.

Per-catheter ASD closure.

Per-catheter devices for atrial septal defect (ASD) closure have been evolving since 1974. The four major devices available for use on a limited basis in early 1997 are reviewed. These include (in alphabetical order) the Angel Wing device, the ASDOS device, the Buttoned device, and the CardioSeal device (successor to the Clamshell). Sufficient data have been collected to indicate that transcatheter ASD closure is a viable alternative to surgery in selected patients. The advantages of the concept of per-catheter closure over surgical closure should lead to the continued development of devices and techniques for per-catheter treatment of ASD and other septal defects in the years to come.

Solar Storms by Linda Hogan

Reviews 301 book, Caught Inside, initially seems merely a re-visioning of his first: we’re still in California, only now we’re at the beach, and instead of climbing, we’re surfing. To the economist, he’s simply substituted one nonproductive avocation for another. For the reader of literature, he’s evolved significantly as a writer: he’s retained all the charm of the memoir (and Lighting Out was nothing if not charming) and combined it with a carefully studied sense of natural history and an even more astutely observed sense of cultural history. Its subtitle announces his strategy: a surfer’s year on the California coast. But his first sentence more precisely stakes out his territory: “Unless you’re a strolling natural­ ist by nature, or a farmer or commercial fisherman or ranger, you need a medium, a game, a pleasure principle that turns knowing your home into passionate scholarship.” The neat trick that Duane has accomplished here is that his “passionate scholarship” is more passionate than scholarly, more natural than a mere excuse for writing a book. In a sense, Duane is ever the novitiate, learning to read the design of his tools (surf­ boards) and the shores of the Pacific, its swells and fauna, the physics of its waves, and the social mores of its inhabitants. But here Duane is not so self-absorbed as a simple memoirist. Sure, he’s a participant, and that ties him nicely to the world he describes. But he also accomplishes what all great writers do: he connects both himself and the reader to the larger world. We learn the history of surfing, its peculiar (to most of us) migration to the continent from the East, its historical context, and, finally, why it mat­ ters. In the great white shark the surfer understands the unknowable wildness of the primeval, natural world. In the swell of the waves is the unchartable, unmapped West of the pioneer. Near the end of the book Duane notes: “It’s unsettling to discover how hard-won is real understanding of place, how much it demands stillness and time; real time, daily visitations.” This epiphanic moment is not in the least tinged with a sense of accom­ plishment or success; rather it’s an admission of humility in the face of nature, a reminder that few of us truly know our homes. We should be grateful to Duane for performing so well the writer’s task, for so elo­ quently reporting to those of us on the outside his hard-earned view from the “inside,” this view of Californiafrom the west, from off the shores of the Pacific. D av id S te v e n s o n W ester n Illin o is Un ive rsity Solar Storms. By Linda Hogan. (New York: Scribner, 1995. 351 pages, $22.00.) Like Linda Hogan’s first novel, Mean Spirit, Solar Storms is a compelling story about material dispossession, the struggle for cultural continuity, and the wisdom and strength of women. Hogan’s long-awaited second novel is informed by her poetic sensibility and her spiritual connection to the earth. The native world of Solar Storms is “a dense soup of love,” where fish talk and spiders listen to thoughts. Entering that ancient and alien world is a tough-talking ward of the state, Angel Wing. A survivor of sexual, physical, and emotional abuse, Angel longs for family connection and for fusion with nature, a state she knows is ultimately unattainable: “What I really wanted none of us would ever have. I wanted an unbroken line between me and the past.” 302 Western American Literature Seeking to recover a part of that lost past, she travels north by canoe with three newly discovered maternal ancestors—Bush, Agnes Iron, and Dora Rouge—whom she locates in a tribal community in the Boundary Waters canoe area of northern Minnesota. Eventually, she succeeds in finding her birth mother and tribal home, the land of the Fat Eaters, only to find both mother and motherland as scarred by abuse as her own face. Angel hopes to recover her tribal self through the painful reconstruction of her per­ sonal past but instead...