Eagle Wing Research Articles

Influence of bioinspired morphing on the flow field characteristics of UAV wings at low Reynolds number

The aerodynamic performance of unmanned aerial vehicles (UAV) can be improved by optimizing the surface flow characteristics over a wide range of angle of attack (AoA) through novel mechanisms. Recently, the bioinspired camber morphing concept has received greater attention because of the proven ability of nature species towards the retention of aerodynamic performance under different environmental conditions. In particular, birds like Eagles ( Accipitriformes) increase their wing camber in the course of flight to achieve maximum climbing altitude with good manoeuvring capability. The biomimetic designs such as the corrugated bone structure of Eel fish ( Anguilliformes) helps to achieve the wing camber morphing with optimal aerodynamic load distributions. The present work is focused on the bioinspired variable camber morphing (VCM) strategy to enhance the flow control behaviour and aerodynamic forces for a specific UAV wing configuration at various AoA. Here, NACA 4412 airfoil is used as a baseline wing configuration and the camber morphing mechanisms which are derived through Eel fish and Eagle are analysed. The model with Eagle wing morphing (EWM) mechanism is considered as a primary case of VCM and Eel fish’s corrugated structure is taken as a secondary case of VCM model. The coefficient of lift ( C L ), coefficient of drag ( C D), coefficient of pressure ( C p) and endurance factor are estimated for both morphed and baseline wing configurations through high fidelity numerical simulations. Interestingly, it is observed that the EWM wing configuration has excellent surface flow control characteristics than the CSM wing configuration and the results are presented with a detailed discussion.

Biomimetic polyaryl ether-based aerogels for efficient interfacial solar water vapor generation

There is an urgent need to design efficient photothermal layer, continuous water migration pathways, and stable insulation layer to simultaneously achieve ideal water and heat management in solar-powered interfacial evaporation systems. Here, we assemble into a biomimetic aerogel with down-feather-like shape by first introducing rigid polyaryl ether material of sulphonated poly (phthalazinone ether sulfone ketone) (SPPESK) for highly efficient and multifunctional solar interfacial evaporation drawing inspiration from the cavity structure and insulation strategy of the eagle wings. The biomimetic aerogel has an evaporation rate of 2.34 kg m−2h−1 at one solar irradiance, an energy efficiency of 91.7 %, and an output voltage of 316.7 mV when coated. The insights provided by this work into biomimetic structure displayed by chitosan/SPPESK/Mxene aerogels promise to translate photothermal conversion performance benefits measured in laboratories into real-world applications for continuous desalination and wastewater purification. We anticipate that our work is a starting point to utilize the full potential of photothermal properties of polyaryl ether-based materials.

Unsteady characteristic study on the flapping wing with the corrugated trailing edge and slotted wingtip

The geometric structure of birds' wings, especially edges and wingtips, plays an important role in improving flight conditions. In order to investigate the changes in flow physics caused by the corrugated trailing edge and wingtip slots, a three-dimensional numerical simulation of the eagle wing with corrugated trailing edge and flapping motion was carried out in forward flight. First, lift and drag forces were compared between numerical and experimental results, showing acceptable agreement. As key parameters, the lift force, thrust force, and lift-to-drag ratio were compared between the modified and the baseline wings. The results revealed that using the modified wing led to the improvement of the lift force by 14% on average compared to the baseline wing; with a maximum increase of 45%. Furthermore, the thrust force of the modified eagle wing was higher than that of the baseline wing by up to 21%. According to the analysis of the flow physics in the present simulation, the pressure difference between the upper and lower surface of the modified eagle wing was larger compared to the baseline wing, and the highest effect on the flow physics was exerted by wingtip slots. Also, the behavior of vortices at different sections across the wing length revealed that the interaction between the wingtip slots led to flow deviation in this region, an increase in the flow kinetic energy in the boundary layer, and a decrease in the flow separation and vortices separated from the wingtip. Further, it caused the separated vortices from the wingtip to change from the concentrated state to smaller vortices with less strength, which reduced the induced drag and enhanced aerodynamic coefficients.

Unsteady aerodynamics of flapping bionic eagle wings in forward flight: An experimental and numerical study

The aerodynamic performance of fabricated eagle wing with the corrugated trailing edge was investigated experimentally and numerically in this study. In this respect, wings were designed by imitating the bionic eagle wing and fabricated using a 3D printer. Tests on the wings were performed in a wind tunnel for different bending deflection angles, flapping frequencies, angles of attack, and forward flight velocities. As the key parameters, lift and thrust forces, lift-to-drag and input power were compared between eagle wing and simplified wing. The results revealed that the eagle wing with the corrugated trailing edge led the lift force to be improved by 14% on average compared to the simplified wing, with the largest improvement of 45%. Further, the thrust force of a eagle wing was greater than that of the simplified wing (up to 21%). Also, the input power of the simplified wing mechanism was greater than that of the eagle wing. Numerical simulations were performed to study flow physics. After validating the numerical results against the experimental results, the lift and thrust force, lift-to-drag, pressure contours and vortex were compared between the eagle and simplified wings. The results of the numerical simulation revealed that lift-to-drag increased with for eagle wing with the corrugated trailing edge of eagle wing. the pressure difference between the upper and lower surfaces of the eagle wing was larger than that of the simplified wing; therefore, the lift force produced by the eagle wing was larger than that of the simplified wing.

Design Analysis of Vertical Axis Wind Turbine Blade Using Biomimicry

Performance and efficiency of a Vertical Axis Wind Turbine improved by using a modified turbine blade, derived from biological features, by harness more wind energy. The detailed simulations were carried in Q-blade’s X-foil, Java foil and Sim Scale software at low wind speed with bio-mimicable cambered foil add-ons to different biostructure blades such as Maple seed leaf, Eagle wing. Among these simulations, the Corrugated Dragonfly vein FX 63-137 foil shows improved performance over cambered foils and FX 63-37 itself. The Maple-Wing combined blade structure showed an improved lift-drag ratio with a high coefficient of power.

Unsteady characteristic research on aerodynamic interaction of slotted wingtip in flapping kinematics

The slotted wingtip structure of birds is considered to be the product of improving flight efficiency in the process of evolution. It can change the vortex structure of wingtip and improve aerodynamic efficiency. This paper reports a numerical investigation of slotted wing configuration undergoing bio-inspired flapping kinematics (consisting of plunging and in-line movement) extracted from a free-flying bald eagle wing. The aim is to eluci-date the collective mechanism of the flow generated by slotted tips and the lift contribution of each tip. Specifi-cally, the objective of the study is to determine how changes in the wing spacing affect the resulting aerodynamic interaction between the slotted tips and how that affects the force generation and efficiency. Changes in the phase angle between the flapping motions of slotted tips, as well as the spacings among them, can affect the resulting vortex inter-actions. The rear tips often operates in the wake of the frontal tips and, meanwhile, the vortex generated by the movement of the rear tips promote the frontal tips. The interaction of vortices in time and space leads to wing-wing interference and the flow around slotted tips becomes complicated and unstable. The innovative study of wingtip slot in unsteady state leads us to find that the aerodynamic interaction among slotted tips makes the overall lift characteristic better than that of the unslotted wings. The slotted wing configuration can efficiently convert more energy into lift. As the flapping frequency increases, the collective feature of slotted wing with constantly changing gaps can be more advantageous to enhance lift-generation performance.

Experiencing Grace and Graceful Moments: In-Between Spaces in Teaching and Learning

Abstract: Teacher education’s dominant narrative is often one that accentuates sure-fire methods in the attainment of curriculum goals and objectives. We offer grace as an orientation that could serve to accentuate the profoundly relational generative space of teaching and learning, and to afford opportunities for taking time and making space in the classroom for inquiry into the living disciplines as a means to further understandings of self, other and curriculum matter. In this paper we explore and interpret Richard Wagamese’s essay “On the wings of eagles” as a portrayal of moments of grace and put it into conversation with our own experiences in teacher education and curriculum theory. Although it is not in the nature of this project to conclude or profess definitive results or methods, our aim is to keep open questions of what it means to be graceful, and to act gracefully in relation to our students and to subject matters. We believe that grace is a way to be in the world that could be transformational for current pedagogical practices.

유인드론용 생체모사 익형의 공력 및 소음특성에 대한 연구

In this paper, the experimental and numerical research on the aerodynamic and noise characteristics of a biomimetic airfoil is reported for the purpose of manned drone propeller design. Through the CFD analysis the aerodynamic performances for four types of airfoil are compared in order to search for the most desirable airfoil platform for the manned drone, and the experiment for the fore-mentioned airfoils were performed to verify their aerodynamic and noise characteristics. The CFD and the experiments show that the eagle wing mimetic airfoil has the maximum lift coefficient of 25 % higher than the other standard airfoil. In the manned drone propeller model test, the eagle model results in the thrust performance of 28.3 % higher than the other standard model. The comparison of sound pressure levels at the same thrust condition shows that the eagle model produces the noise level of 1.9 dB<SUB>A</SUB>lower than that of the conventional NACA-based model. The biomimetic eagle-wing airfoil can be effectively applied to the manned drone system which requires both the high payload and the reliability.

A Retrospective Imaging Evaluation of Presynaptic Dopaminergic Degeneration in Multiple System Atrophy with Levodopa Induced Dyskinesia

Background:Multiple system atrophy (MSA) may develop levodopa-induced dyskinesia, which is dystonic and predominant in the orofacial region. We aimed to characterize the patterns of presynaptic dopaminergic degeneration in patients with MSA and dyskinesia using 123I-N-x-fluoropropyl-2b-carbo-methoxy-3b-(4-iodophenyl) nortropan single-photon emission computed tomography (123I-FP-CIT SPECT).Methods:A single center cross-sectional retrospective study was conducted using consecutive chart review of patients with probable MSA who underwent 123I-FP-CIT SPECT. The degeneration patterns were compared between the groups with and without dyskinesia via visual assessment of 123I-FP-CIT SPECT images.Results:Twenty-five patients with probable MSA who had undergone dopamine transporter imaging were identified (age [mean ± standard error], 62.5 ± 1.7 years; disease duration, 48.8 ± 7.0 months). Four of them presented dyskinesia and 21 of patients did not. Twenty-five patients with MSA were visually classified into five grades: one Grade 1 (normal), two Grade 2 (eagle wing), three Grade 3 (mixed), nine Grade 4 (egg shape), and ten Grade 5 (burst striatum). All patients with MSA and dyskinesia were classified into Grade 5. Visual grading significantly correlated with disease duration and levodopa responsiveness.Conclusions:Severe presynaptic dopaminergic dysfunction in 123I-FP-CIT SPECT images, higher doses of dopaminergic medication, and longer disease durations were associated with occurrence of levodopa-induced dyskinesia, even in MSA.

Bald eagles and the Thunderbird myth: Birds in pre-contact ceremonialism on Martha's Vineyard, USA

Ceremonialism is an integral part of human life but difficult to recover from archaeological remains. Among Native groups in Eastern North America, skins and feathers of birds were commonly used as part of ritual feast ceremonies, including those of the Thunderbird, a mythological creature associated with thunder, lightning, and the upper world. Physical evidence for the Thunderbird has been limited to ceramic, lithic, copper, and petroglyphic artifacts, but the recent discovery of a series of Bald eagle (Haliaeetus leucocephalus) wing bones from the Frisby Butler site may present the first faunal evidence for the myth in Native North America. Patterns of skeletal part representation within the assemblage and across the site suggest that the deposit is the remains of a ritual feast and the presence of multiple wings indicates intentional curation of eagles. If so, this is the earliest known Thunderbird association on the island of Martha's Vineyard, showing the spread of extant Algonquin cosmology to this area by at least 2,000 BP.

Experiencing Grace and Graceful Moments: In-Between Spaces in Teaching and Learning

Abstract: Teacher education’s dominant narrative is often one that accentuates sure-fire methods in the attainment of curriculum goals and objectives. We offer grace as an orientation that could serve to accentuate the profoundly relational generative space of teaching and learning, and to afford opportunities for taking time and making space in the classroom for inquiry into the living disciplines as a means to further understandings of self, other and curriculum matter. In this paper we explore and interpret Richard Wagamese’s essay “On the wings of eagles” as a portrayal of moments of grace and put it into conversation with our own experiences in teacher education and curriculum theory. Although it is not in the nature of this project to conclude or profess definitive results or methods, our aim is to keep open questions of what it means to be graceful, and to act gracefully in relation to our students and to subject matters. We believe that grace is a way to be in the world that could be transformational for current pedagogical practices.

“Sometimes Things Get Worse Before They Get Better”: A Counter-Narrative of White Suburban School Leadership for Racial Equity

ABSTRACTElizabeth is a middle-class white woman and principal of Eagle Wings High School, a large, well-resourced, high-performing suburban high school. This manuscript uses a Critical Race Theory composite counterstory to analyze Elizabeth’s experiences of racial conflict that resulted after she enacted equity reforms to address her school’s history of racial inequity. We examine the manner in which Elizabeth’s decision-making for students of color related to her racial meaning-making and identities and how the resistance Elizabeth faced was not merely from teachers or white parents, but also from within herself.

Songs of Sorrow: Bardic Women in Girodet, Ossian, and Staël

Songs of Sorrow:Bardic Women in Girodet, Ossian, and Staël Tili Boon Cuillé (bio) As we look at Anne-Louis Girodet's Apothéose des héros français morts pour la patrie pendant la guerre de la liberté displayed in the Salon of 1802, commissioned by Napoleon for Malmaison, and inspired by the epics attributed to his favorite poet Ossian, our eye is drawn toward the Scots bard and the French general at the canvas's center (Figure 1). The dove of peace betwixt Odin's eagle and the French cockerel above and the vessels raised in a toast below intensify our focus. We are also vividly aware of the contrast between the Romantic style of Fingal's troops on the left and the Neoclassical style of Napoleon's on the right.1 If we wrest our eyes from the vertical line that divides the painting, however, they are drawn to the winged victory flying down from above and the myriads of maidens surging up from below. In his gloss of the painting on the occasion of its return to Malmaison after a century's sojourn in Germany, Jean Bourguignon considers these maidens evocative of the Valkyries, on the one hand, and mythological painting, on the other.2 We may, accordingly, be inclined to view them as nereids or muses. Yet they also caught the eye of Girodet's pupil Hyacinthe Louis Aubry-Lecomte, for they are featured in a disproportionate number of the lithographs in his Collection de têtes d'étude of 1822, where he identifies them by name. What becomes apparent in these studies is that the maidens bear instruments (Figures 2–3). Who are these women and what was their role? Women appear in interpolated love stories throughout Ossian's poetry. Some die for men, others die at men's hands, still others take their own lives or simply fade away. Whether female warriors or hapless victims, they are uniformly of melancholy disposition. Yet beyond their fierce loyalty, moral fortitude, and tragic fates, these women are also [End Page 159] bards.3 Cómala—whose face is concealed by the eagle's wing in Girodet's painting but whose Celtic rebec is clearly visible—was betrothed to Fingal when he fell in battle. While all that is left of Fingal is a vision, what remains of Cómala is a voice.4 Malvina, betrothed to Ossian's son Oscar, likewise did not survive him. Leith Davis describes her as "the addressee of many of Ossian's poems and, more importantly, a bard in her own right."5 Girodet depicts Malvina alongside Ossian's wife Evirallin, both playing citheras.6 Evirallin was also a bard in her own right, for Ossian and Carril recall the days when they blended voices and she "touched the harp of music."7 While Ossian, Carril, and Ullin sing the tales that comprise Fingal, the epic nevertheless resonates with women's "songs of grief." Fingal's narrative structure embeds Brassolis's song of Grudar within Carril's song of Brassolis within Ossian's song of Carril. The metadiegetic bard is a woman.8 Girodet's painting, depicting women armed with instruments rather than weapons, recalls their status not as warriors or mourners but rather as musicians. Click for larger view View full resolution Figure 1. Anne-Louis Girodet de Roussy-Trioson, Apothéose des héros français morts pour la patrie pendant la guerre de la liberté [The Apotheosis of French Heroes Who Died for Their Country During the War of Liberty], 1802. Chateau de Malmaison et Bois-Preau. (Photo: Erich Lessing/Art Resource, NY) [End Page 160] Click for larger view View full resolution Figure 2. Hyacinthe Louis Victor Jean-Baptiste Aubry-Lecomte, Comala, Plate 8 from Collection de têtes d'étude, 1821–1822. Chateau de Malmaison et Bois-Preau. (Photo: RMN-Grand Palais/Art Resource, NY) Click for larger view View full resolution Figure 3. Hyacinthe Louis Victor Jean-Baptiste Aubry-Lecomte, Evirallina, Malvina, Plate 15 from Collection de têtes d'étude, 1821–1822. Chateau de Malmaison et Bois-Preau. (Photo: RMN-Grand Palais/Art Resource, NY) [End Page 161] Germaine de Staël heralded...

Relationship between striatal 123I-FP-CIT uptake and cognitive functions in Parkinson's disease

We studied whether 123I-FP-CIT uptake in the striatum correlates with cognitive performance in patients with Parkinson's disease (PD). Sixty-nine patients with PD (24 men and 45 women, average age = 71.3 years, disease duration = 5.2 years) underwent 123I-FP-CIT SPECT and neuropsychiatric measurements. Cognitive performance was assessed using the MMSE (Mini-mental state examination), TMT (Trail making test), MoCA-J (Japanese version of Montreal cognitive assessment), FAB (Frontal assessment battery), ACE-R (Addenbrooke's cognitive examination revised), BDI-II (Beck depression inventory-II), and RBMT (Rivermead behavioural memory test) in the ON state. The average specific binding ratio (SBR) and AI (Asymmetry index) of striatal 123I-FP-CIT uptake were semi-quantitatively measured using DaTView software. Clinical data and SBR were compared. In addition, participants were divided into four groups according to the visibility of the striatum on 123I-FP-CIT SPECT images, and results of the Eagle Wing (EW) group and the Egg shape (ES) group were compared. SBR was negatively correlated with age (P < 0.001), disease duration (P < 0.001), H-Y stage (P < 0.001), levodopa equivalent dose (P = 0.004), TMT-A (P = 0.001), and TMT-B (P < 0.001), and positively correlated with MMSE (P = 0.021) and FAB (P = 0.029), MoCA-J (P = 0.012)，RBMT (P = 0.021). Multiple regression analysis confirmed that age (P = 0.016) and FAB (P = 0.035) were independent predictors for SBR. Furthermore, in the ES group, Movement Disorder Society - Unified Parkinson's disease rating scale part III scores were significantly higher (P = 0.013) and the AI was lower (P < 0.001) than those in the EW group. Conversely, there were no differences in the findings of neuropsychiatric measures between the two groups. Our study results demonstrate that imaging with 123I-FP-CIT SPECT is sensitive for detecting dopaminergic deficits associated with frontal lobe functions in patients with PD.

Summoning the Ghost Bear

Summoning the Ghost Bear Kim Todd (bio) Click for larger view View full resolution [End Page 72] Reports of a large, gray grizzly gathered thick as mist in the North Cascades of Washington State in the 1940s. A hunter after deer near White Chuck Cinder Cone glimpsed a silvery mother and cub. Near Fire Mountain, not far from the town of Darrington, a grizzly with long gray fur and two cubs ran at a man on the trail. She chased him up a tree, raking through his boot to his foot with roughly three-inch claws. After an hour and a half in the branches, he was rescued, carried out on a horse. Roughly a year later, the bear—or a similar one with gray fur that fluttered "like a flying squirrel," an observer reported—charged at a family of six who were admiring the view from Fire Mountain. The husband shot the bear, who stopped, veered off toward Fire Creek, and then disappeared. At the time, grizzlies like these were [End Page 73] common enough that no one was surprised, but rare enough to make the newspapers. Their longtime presence in this sodden landscape along the Canadian border—characterized by sharp peaks, silver fir forests, and riotous rivers draining them—was memorialized in hunting accounts of the Salish peoples and, later, fur trading records of the Hudson Bay Company. Accounts of bears from white settlers moving in and claiming land during the late nineteenth century carried a whiff of the fable and violence of Davy Crockett tall tales. In 1888, one grizzly was shot with seven bullets, finally dying just a few moments before reaching the hunter. In 1924, an animal referred to as "a monster grizzly bear, whose footprints are as large as an ordinary hat" plundered campsites for bacon. They ravaged sheep, killed cows, and, wounded, left long, bloody trails into the bushes. Not long after the silver sow abandoned Fire Mountain, though, grizzlies became increasingly scarce. And as scientists tried to puzzle out reasons for the decline, they collected these stories, attempting to turn them into data points. Paul Sullivan, the author of a 1983 report tallying grizzly bear sightings in the North Cascades, commented on the challenge of this documentation: witnesses had died; others offered conflicting reports; still others were known to be serial exaggerators. Many white colonists' early reports of bear encounters seemed like mythological battles. But the mythologizing resulted from the nature of the observations, the glory, the dread. Sullivan wrote: "I am keenly aware that encounters with wildlife species as majestic or fearsome as the grizzly bear are privileged moments in the life of any observer." Grizzlies, like other large, fierce animals, generate legends. The introduction to my middle school short-story anthology outlined the three kinds of conflict: man versus man, man versus nature, man versus himself. "You will like these stories," the preface concluded, which I thought a bit presumptuous. But it is true that humans versus nature, particularly nature in the form of a beast, is one of Western culture's oldest forms. Hercules stalking the hydra to its swampy lair, holding his breath against the poisonous scent of the monster. Or Odysseus, slipping his ship past the hungry mouth of Scylla, lurking in her cave with her triple row of fangs, or Beowulf, challenging ravenous Grendel, who consumes men entirely, drinking their blood and eating even their hands and feet. Part of the terror of the beast is its unknowability. The heat of its breath, the sharpness of claws that might remind you of those that raked an arm as you lifted the cat off the kitchen table, though, much, much larger. Who knows what the beast is thinking, how its mind is organized, how its bizarre body—all those necks, or a lion torso topped by eagle wings—works? A theory I love proposes that dragons and other early monsters were based on dinosaur bones, unearthed and dressed in the papier-mâché of assumptions, with imagination offering the breath of life. But what happens when these beast stories take as their subject actual animals? When the werewolf is real a wolf? [End Page 74] Or a...

Usefulness Differs Between the Visual Assessment and Specific Binding Ratio of 123I-Ioflupane SPECT in Assessing Clinical Symptoms of Drug-Naïve Parkinson's Disease Patients.

Background: In clinical practice, assessment of the striatal accumulation in 123I-ioflupane single photon emission computed tomography (SPECT) is commonly performed calculating the specific binding ratio (SBR) for the whole striatum. On the other hand, visual assessment of striatal accumulation in the SPECT was recently established. However, correlations of visual assessment with motor and cognitive functions in Parkinson’s disease (PD) have rarely been examined. Differences in the usefulness of these assessments at clinics are uncertain.Objective: We performed this study to compare correlations of cognitive and motor functions in drug-naive PD between the SBR and visual assessment using 123I-ioflupane SPECT.Methods: Cognitive and motor assessments and 123I-ioflupane SPECT were performed in 47 drug-naïve PD patients with Mini-mental State Examination scores of ≥25. Cognitive function was assessed using the total score and 6 subscores of the Montreal Cognitive Assessment (MoCA) and 10 separate subtests of the Neurobehavioral Cognitive Status Examination (COGNISTAT). Motor function was assessed using the Hoehn and Yahr scale and Unified Parkinson’s Disease Rating Scale. Accumulation of 123I-ioflupane was determined by visual assessment based on five grades: 1, burst striatum; 2, egg-shaped; 3, mixed type; 4, eagle wing; 5, normal striatum; and by calculating SBR averaged for the bilateral striatum using the DaTView computer software commonly used in clinical practice. Each SPECT assessment was compared with each subscore for cognitive and motor assessments.Results: Spearman correlation analysis showed SBR was significantly correlated with the MoCA subscores of visuospatial function and attention, and with COGNISTAT subtests of attention. Visual assessment showed significant negative correlation with the Hoehn and Yahr scale. Mean score of postural instability in patients with visual grade of 1 was significantly higher than those in patients with visual grades of 2 and 3.Conclusion: Clinical symptoms reflected by 123I-ioflupane SPECT differ between the SBR and visual assessment. SBR reflects some cognitive functions, whereas a visual assessment grade of 1, which signifies decreased uptake of 123I-Ioflupane in the caudate nucleus, reflects postural instability. Thus, the caudate nucleus may play an important role in posture maintenance. Our results suggest that performing both assessments is of value.

Optimization of flapping wing mechanism of bionic eagle

The present study is focused on optimization of a double-crank-rocker flapping wing mechanism to imitate the motion of eagle wing divided into inner and outer wing with flapping, folding and twist degree of freedom, and structural flexibility. Considering the multibar dimensions of the flapping mechanism as design variables, combinatorial optimization method was applied to maximize the aerodynamic efficiency. Based on the optimization results, a bionic eagle model of 1.5 m wing span was manufactured to perform flight tests. The study results show that the optimized kinematic of motion can be achieved by using the multibar flapping mechanism; the inner wing plays the key role of producing lift while the outer wing producing thrust; as a result of the optimization, the lift was increased by 2.8% from 3.85 N up to 3.96 N and the thrust increased by 12.5% from 0.16 N up to 0.18 N, which was verified by the flight tests. The flight test also demonstrated a sustainable level flight of the bionic eagle model at a flapping frequency of 2 Hz.

Srpski Nemanjićki grbovni simboli - orlovo krilo u grbu hrvatskoga bana Pavla i Bribirskog

Pavao Bribirski the First was one of the most important rulers in Croatian history of all times. He had in his title, it was found out about this based on charts, currency and seal, several names, starting from 'Potestatis Traguriensis' (1272-1273) the head of Trogir, 'Comes Spalatensis' of the Prince of Split, 'Banus Maritimus' of Maritime Ban, 'Banus Sclavinie' Ban of Slavonia that is, Croatia, 'Banus Croatorum' et Dominus of Bosna' Ban of Croatia and master of Bosnia, 'Banus Paulus Chroatorum Bosneque Dominis' Ban Pavao the master of Croatia and Bosnia, 'Dominus Dalmatie' the master of Dalmatia, until 'Duh Dalmatie' the head (prince) of Dalmatia and Croatia and some other titles. There has been preserved until now two seals of Pavao Bribirski, issued in Solin in 1300, and Knin in 1307. Nevertheless, in 1961 the seal of Pavao Bribirski was found in Zadar during an archaeological excavation. Pavao's coat of arms of the twig jaundice and eagle's wing is visible on the seal. It was raised the thesis that eagle's wing on the seal represented the symbol of the house of the Serbian family of Nemanjić's. Namely, Pavao had for his wife Ursa, the daughter of the Serbian king Dragutin. During the marriage, Ursa made the connection of her coat of arms (eagle) - eagle's wing with the one of her husband - twig jaundice. So, the coat of arms of Pavao Bribirski appeared. The fact that none of Croatian rulers from the medieval period had coat of arms of the eagle, and Serbian Nemanjići had two-headed eagle, and that one of the basic rules of heraldic with marriage meant coat of arms of woman was added to the one of husband where it took up central place, spoke on behalf of our opinion.

On the Wings of Eagles.

On the Wings of Eagles.

Dorsal Approach Rhinoplasty

ABSTRACTDirect dorsal excision of skin and subcutaneous tissue is employed in rhinoplasty cases characterized by thick rigid skin to achieve satisfactory esthetic results, in which attempted repair by more conventional means would most likely frustrate both surgeon and patient.This historical review reminds us of the lesson: ‘History repeats itself.’ Built on a foundation of reconstructive rhinoplasty, modern cosmetic and corrective rhinoplasty have seen the parallel development of both open and closed techniques as ‘new’ methods are introduced and reintroduced again. It is from the perspective of constant evolution in the art of rhinoplasty surgery that the author presents, in Part II, his unique ‘eagle wing’ chevron incision technique of dorsal approach rhinoplasty, to overcome the problems posed by the rigid skin nose.