Fly Off Research Articles

Towards diagnostics of aerospace structural defects using a novel physics-based post-processing scheme employing lock-in thermography

During its service life, an aircraft experiences various loadings that affect its structural performance. Thin sheet riveted joints are ubiquitous in aircraft and require thorough inspections to arrest any defects that may cause catastrophic failure. Subsequently once flown off, loose and/or cracked rivets may get stuck in critical areas such as flight controls or get ingested into the engine and become a source of Internal Object Damage (IoD). While several inspection schemes are employed in the aviation industry for rivets-related defect detection, most of them are subjective and skill-dependent. Towards the aim of developing an efficient rivet defects diagnostic technique, in this research work, a novel physics-based post-processing scheme employing lock-in thermography (LIT) is proposed for the detection of such defects. For this purpose, a hierarchical experimental thrust has been adopted, where in the beginning the scheme was developed on the lab experiments which was further extended/refined to detect defects on actual aircraft. Two different post-processing techniques have been used for the interpretation of LIT, namely the Fast Fourier Transform (FFT) technique and an indigenously developed temporal temperature gradient-based approach to capture defects whereby localized thermal emissivity variance at the defect location affects the local thermal conductivity and the surface temperature profile. The study considers two common defect i.e., looseness and sub-surface cracks in rivets. The results obtained from the novel post-processing technique provide empirical understanding, better quantification, and clearer comprehension of the two types of rivets-related defects by making it more objective as compared to the FFT technique. The proposed novel methodology in this work exhibits higher fidelity than conventional FFT by accurately identifying the rivet defects thereby providing a promising alternative to in-vogue visual inspections.

REDUCTION OF THE RISK OF DAMAGE AT PROJECTILE DEBRIS PROJECTILE EFFECT

Problem statement. The task of assessing the risk of damage to an oil storage facility by debris in the event of a drone explosion is considered. An analysis of the debris movement velocity and the effectiveness of the use of a protective barrier to stop the debris movement in the direction of the oil storage facility is carried out. The purpose of the article. Assessment of the risk of damage to the oil storage wall and the effectiveness of the use of a protective barrier against the throwing action of debris during a drone explosion. Methodology. A numerical model based on the integration of the equation of a material point motion and an empirical model is used to analyze the risk of damage to an oil storage facility when the debris of a drone flies off. The developed numerical model takes into account the initial velocity and size of the debris, the direction of the debris movement, and the height of the debris ejection. On the basis of this numerical model, a computer code was created for conducting a computational experiment. Scientific novelty. An effective mathematical model is developed for analyzing the risk of damage to an oil storage facility from the throwing action of debris generated by a drone explosion. The model makes it possible to determine the effectiveness of using an obstacle to protect an oil storage facility from the throwing action of debris. Practical value. A computer code is developed for calculating the dynamics of the debris movement in the air, which are formed during the explosion of a drone. The use of this code makes it possible to select the rational dimensions of the protective barrier at the industrial site to protect the oil storage from damage. Conclusions. An effective tool for analyzing the risk of damage to an oil storage facility from the throwing action of debris created by a drone explosion is developed. The results of computational experiments are presented.

Behavioural interactions between co‐habiting females and their impact on productivity and offspring sex ratios in the coffee berry borer, Hypothenemus hampei

Abstract The coffee berry borer (CBB) Hypothenemus hampei (Ferrari) (Coleoptera: Curculionidae: Scolytinae) has invaded all coffee‐producing regions of the world and causes substantial economic losses every year. A single female beetle typically infests one coffee berry, which her offspring consume over the course of development. Offspring then engage in sib‐mating before daughters fly off to infest new berries. We assessed infestation rates across different locations in Jamaica and found a strong positive correlation between double infestation and overall infestation rate, suggesting that females prefer to breed alone but will tolerate sharing a berry under resource constraints. Using an artificial habitat to study productivity and behaviour in the laboratory, we found that single females produced significantly more offspring per capita than two females, suggesting that co‐habitation is costly. Accordingly, co‐habiting females spent a significant proportion of their time engaged in antagonistic interactive behaviours such as pushing. When daughter beetles were given the opportunity to stay with their mothers or to infest a new berry, they tended to leave. In contrast to some related beetle species, which exhibit gregariousness and even cooperative behaviour, beneficial social interactions in the CBB appear to be limited to parental care.

Oh No, The Aunts Are Here by Adam Rex

Reviewed by: Oh No, The Aunts Are Here by Adam Rex Kate Quealy-Gainer Rex, Adam Oh No, The Aunts Are Here; illus. by Lian Cho. Chronicle, 2023 [40p] Trade ed. ISBN 9781797207940 $16.99 Reviewed from digital galleys R 5-8 yrs Our young protagonist's quiet breakfast becomes decidedly less so with the arrival of her four aunts, who are armed with fanny packs, hand sanitizers, and an overwhelming lack of physical boundaries. After enduring a predictable (but not at all enjoyable) round of hugging, pinching, and poking, the bewildered young girl is then grilled on nearly every life topic as they drive to the (not at all) exciting Quilt Museum. That evening, the aunts take over the girl's bedroom, and the next morning, they've co-opted bathrooms, showers, and the breakfast tables—but wait, there's one more aunt than last night, and she's particularly hairy and fearsome looking. "It's a wolf. A wolf 's come to eat you," but the aunts quickly dispatch of the fearsome canine and then promptly turn into colorful birds, chatting away as they fly off. The dip into the absurd wolf storyline is an odd but wise authorial choice, rescuing the aunts' image as much as it (literally) rescues the girl: the four relentlessly annoying women come to her aid when needed, making a sweet allegory for finding support among family, even when that family is especially chaotic. The narrative's direct address enhances the potential for relatability here, and plenty of kids will find kinship with the girl beleaguered by ruthlessly interfering relatives. Loose linework calls up Patricia Polacco's styling with an added dash of vibrant cartoonishness, and the aunts move through the pages with vim and vigor, dominating the spreads as much as they dominate their niece's current situation. While she appreciates the aunts' dealing with the wolf, the little girl clearly is happy to see them gone . . . until more relatives show up in the last page. Copyright © 2023 The Board of Trustees of the University of Illinois

Development of all new structure of Dicing Die Attach Film (DDAF) for Stealth Dicing and Cool Expansion processes

Mobile devices, including smart phones and tablets, are increasing in complexity and require ever greater amounts of memory storage. In the past the challenge of higher memory densities and increase functionality has been met through miniaturization of device features, but as we reach the physical limits of feature size, packaging is being relied on more and more to achieve the necessary higher densities in memory and additional device functionality. Thin dies reduce overall package height, however, to achieve high memory densities in low profile packages the die attach material must have an even, thin bond line thickness. DAF (Die Attach Film) is an excellent solution. LINTEC developed an all new DDAF (Dicing Die Attach Film) with thinner DAF for CE (Cool Expansion) process. Conventional tape has a large area of exposed DAF surface which creates the risk of wafer and / or equipment contamination if DAF flies off during the CE process. We developed an all-new tape structure which is compatible with the SD (Stealth Dicing) and CE processes. The structure consists of DAF, IB (Intermediate Basefilm), and dicing tape. The diameter of the DAF and IB is close to the wafer diameter size to significantly reduce the risk of DAF separation and ejection during CE. We considered IB to improve DAF separation and it was found that a thinner IB layer is a good approach to separate DAF effectively. We can adjust adhesion between the DAF and the IB by changing the material properties of the IB, as an effective means to control die-fly and pick-up.

I Am a GREAT Friend! by Lauren Stohler

Reviewed by: I Am a GREAT Friend! by Lauren Stohler Kate Quealy-Gainer, Editor Stohler, Lauren I Am a GREAT Friend!; written and illus. by Lauren Stohler. Atheneum, 2023 [48p] Trade ed. ISBN 9781665918336 $18.99 E-book ed. ISBN 9781665918343 $10.99 Reviewed from digital galleys R 4-7 yrs A group of capybaras grazing at the edge of a pond are so chill that birds settle upon their still bodies to hang out. Unfortunately, Baby Capybara is not at all chill but doesn’t understand why he has no avian pals for himself: “I am FUN! I am FASCINATING! I AM A GREAT FRIEND!” When he follows the calming guidance of his mother to be still and gentle, he does indeed get a flock of friends, but they soon fly off as he gallops away, climbing rocks, jumping the pond, etc. Despairing, he goes to mope alone in the water where he finds a little caiman who finds Baby Capybara’s antics delightful, and the two become fast friends. This is a joyful celebration of finding your people—er, reptiles—and it balances the idea of respecting others’ preferences while still honoring your own. Capybara’s frustration with his fellow capybaras and his subsequent dejection at their dismissal will be keenly felt by any kid who hasn’t found a pal who shares their interests, while the enthusiastic, quirky caiman is simply a hoot. The digital illustrations with cool sky blues and lush greens make a visually appealing setting for the rotund, gleeful Baby Capybara to run amok through, and varying compositions convey the early serenity of the pond and its resting capybaras with the energized chaos of the two new friends. This makes an obvious pair to Frost’s Capybara is Friends with Everyone (BCCB 02/22) for a hilarious storytime centered around this adorable, portly rodent. Copyright © 2023 The Board of Trustees of the University of Illinois

Point of Departure

"Point of Departure" features a speaker who sees a car's hood fly off on her drive over a viaduct, which triggers a memory about a miscarriage.

Nipple Day

Nipple Day

Þrymskviða, Þrymlur, and Tord af Havsgaard—a Case of Early Antiquarianism?

<i>Þrymskviða</i>, <i>Þrymlur</i>, and <i>Tord af Havsgaard</i>—a Case of Early Antiquarianism?

The Hairy Ape

The Hairy Ape

The Work of Community in Raposa's Theosemiotic

The Work of Community in Raposa's Theosemiotic

Optimization Methods Applied to Motion Planning of Unmanned Aerial Vehicles: A Review

A system that can fly off and touches down to execute particular tasks is a flying robot. Nowadays, these flying robots are capable of flying without human control and make decisions according to the situation with the help of onboard sensors and controllers. Among flying robots, Unmanned Aerial Vehicles (UAVs) are highly attractive and applicable for military and civilian purposes. These applications require motion planning of UAVs along with collision avoidance protocols to get better robustness and a faster convergence rate to meet the target. Further, the optimization algorithm improves the performance of the system and minimizes the convergence error. In this survey, diverse scholarly articles were gathered to highlight the motion planning for UAVs that use bio-inspired algorithms. This study will assist researchers in understanding the latest work done in the motion planning of UAVs through various optimization techniques. Moreover, this review presents the contributions and limitations of every article to show the effectiveness of the proposed work.

Honeybee clusters seethe to keep cool as air temperatures rise

Packing up to relocate is always daunting, but imagine uprooting an entire community and setting forth with no final destination in mind. This is the prospect faced by swarming honeybees as they depart in search of pastures new. Having located a nearby tree, the swarm settles while scouts venture off in search of a new home, yet the cluster continually seethes and churns to maintain a stable temperature within. However, no one had detailed the precise changes that a swarm makes as air temperatures rise and fall. To learn more, Jacob Peters and L. Mahadevan from Harvard University, USA, with Orit Peleg from the University of Colorado, USA, secured a box containing a queen bee to an inverted weighing scale and encouraged the colony to swarm around her, to find out how they adapted as the temperature rose and fell.However, the team quickly found that they were best conducting their experiments at night. ‘On warm sunny days the bees would fly off as if to a new nest site’, recalls Peters. So he and Peleg warmed the clusters from 15°C to 30°C at different rates before keeping the insects warm for 5 h. During that time, the duo took 360 deg snapshots of the clusters every 4 min by swinging a camera around the cluster, taking a picture every 9 deg, to build a 3D profile. Then the duo cooled the air around each cluster at the same rate, to find out how the bees reacted. In addition, James MacArthur from Harvard University designed a bespoke temperature sensor for the bees to cluster around that recorded the temperatures experienced within the colony as it churned in response to the changing air temperatures.Reconstructing time-lapse movies of the clusters, the team could see them become longer and broader as the temperature rose, almost doubling their volume at the highest temperature. ‘A quick look at the time lapse showed dramatic and predictable changes’, says Peters. However, even after 5 h at 30°C, the swarm never achieved a stable structure, continuing to ripple and pulse until Peters and Peleg turned the thermostat down. Yet, the time-lapse movies of the cooling colonies appearing to deflate weren't simple rewinds of the warming expansions. ‘The cluster shrinks quickly in response to cooling but expands sluggishly to its original size as it warms back up’, says Peters.The team also noticed that at one point during the heating process the cluster stopped lengthening and began shortening instead, even though the base continued to broaden, probably because there is a stage when the honeybees within are at full stretch and can no longer cling on to each other if the cluster continues growing longer to avoid overheating. ‘This [manoeuvre] allows them to increase their surface area without a dramatic decrease in density’, says Peters. And, when the temperature around the colony fell, the colony shortened more rapidly than it narrowed, probably because it is easier for bees to climb up and down chains of their sisters than it is for the insects to move inward carrying their colony mates suspended below. The colonies’ pulsating manoeuvres also successfully maintained relatively warm temperatures within (30–36°C), while remaining cooler at the periphery.So, honeybees are able to regulate the temperature within a cluster by spreading apart as air temperatures rise, but they can only go so far before the swarm is in danger of disintegrating. Peters also warns that if environmental temperatures continue to rise, the forces within expanding clusters may be too great for resting swarms to withstand shattering as they attempt to avoid overheating.

‘A problem to be faced about history’: Marion Milner on holiday

‘A problem to be faced about history’: Marion Milner on holiday

Проблемы локализации внутриглазного вколоченного инородного тела. Клинический случай

The article describes a clinical case of an eye injury with presence an intraocular foreign body (IFB), the localization of which was problematic. Patient T was 28 years old, was admitted with complaints of lack of vision, redness and lacrimation from the left eye. From the anamnesis – while working, he hit metal with a hammer, and the scale flew off into the left eye. In addition to the standard ophthalmologic examination, electrophysiological examination, B-scan and UBM were performed. According to the B-scan data, high optical density IFB was detected in the shells 9 mm from the upper border of the optic disc, in the 1-hour meridian, approximately 3.5 mm long. According to the X-ray data of the orbit in 2 projections, an X-ray contrast shadow, metal density, up to 3.0 mm in size was revealed. Radiography of Baltin–Comberg was not performed due to the lack of technical capability. During a standard three-port vitrectomy in the area of possible foreign body occurrence, the retina was damaged, there was a local detachment, but the foreign body itself was not visualized. In addition, during a thorough, detailed examination using a sclerocompressor, no visible defects of the sclera were found transvitreally. In the early postoperative period, the patient was performed with a computed tomogram, where the presence of a foreign body was confirmed, which was adjacent to the posterior wall of the eyeball for 1 hour with clear contours, measuring 3х3 mm. Taking into account the non-standard situation, the absence of a foreign body in the vitreous cavity, it was decided to re-search and remove the foreign body by using of the diascleral method. For a clearer contrast, diaphanoscopy was used, which made it possible to visualize and accurately localize a foreign body in the layers of the sclera. Conclusion. In the presence of IFB for search and precise localization, it is first of all necessary to perform the radiological Baltin-Comberg method. In cases when FB is not visualized intraoperatively, is impaled into the layers of the eye and the radiological Baltin-Comberg method has not been performed, diaphanoscopy of the eye is the optimal auxiliary method for searching for «hidden» foreign bodies. Key words: intraocular foreign body, radiological method of Baltin-Comberg, diaphanoscopy of the eye.

A World without Echoes

A World without Echoes

Three Afrikaans Poems

POETRY Ilse van Staden is a writer, artist, and veterinarian. Though most of her published work (poetry, short stories, and a novel) is in her home language, Afrikaans, she has now also published two novels in English. Peter Constantine’s recent translations include works by Augustine, Rousseau, Machiavelli, and Tolstoy; he is a Guggenheim Fellow and winner of the PEN Translation Prize as well as a National Translation Award. He is professor of translation studies at the University of Connecticut. Visit worldlit.org to read Peter Constantine’s interview with Ilse van Staden. Three Afrikaans Poems by Ilse van Staden return oh, that fish could swim through my garden again! Stately as whale sharks, speckled pacifists, or goldfish freed from small glass domes like marigolds between creepers maybe a coelacanth or two— millennia back there was a lake here, a sea, if one believes the history of the rocks rock, house, origin, everything goes back an eternity I gaze like the old, old philosophers forward into the past and over my back break waves of tomorrow, the day after tomorrow, some year, amid the earthworms gathered there among the skeletons of leviathans, serpents, and bones of other obsolete animals, finally mine too. door you who are holding the hammer in one hand say you blatantly and unashamedly say that this opening should be achieved with caution no bullets through churches open sesame is good enough because wood like trees still understands words softly spoken the magic of a word of doubt without ax or chisel. traveling by house toward death as the orchestra apparently continued to play, it is fitting I share with Mozart the moment when the house suddenly raises anchor and pulls away from the rock the chains break birds fly off indignantly worms go tumbling through clumps of earth and carefully the house points its bow past shed and rock garden through the portholes I can see the old karee willow meekly fluttering its eyelashes at our once-in-a-lifetime maiden voyage. Translations from the Afrikaans By Peter Constantine WORLDLIT.ORG 37 PHOTO BY SEAN THOMAS / UNSPLASH ...

Predatory arthropod community composition in apple orchards: Orchard management, landscape structure and sampling method

AbstractStudies on predatory arthropods in agricultural areas seldom include Diptera other than hoverflies, partly because common sampling methods are less effective for capturing species that easily fly off when disturbed. To study the effect from this bias when describing the predator community, we compared traditional beat sampling of branches and suction sampling for describing the community of predatory arthropods in Swedish apple orchards, both organic orchards and orchards using integrated pest management (IPM). Our results indicate that the proportion of both predatory dipterans and parasitic hymenopterans increase dramatically when using suction sampling (Diptera: 32% vs. 20%, Hymenoptera: 25% vs. 7%). In fact, predatory dipterans were the most abundant predatory group when using suction sampling, in contrast to beat sampling where spiders were the most abundant group. One group of predatory flies that was particularly rich in both species and individuals in the surveyed apple orchards was dance flies in the family Hybotidae. Even though the bias of sampling method was evident, it was encouraging that the method choice did not affect the conclusions concerning management on predatory arthropod communities. With both methods, dipteran and coleopteran predators were more abundant in organic apple orchards whereas opilionids were more abundant in orchards managed according to IPM. The inclusion of landscape variables further indicated effects of landscape diversity and of deciduous forest cover, but the response varied in sign between predatory groups. Whereas both Coleoptera and Heteroptera were more abundant in orchards surrounded by more complex landscapes (high landscape diversity and/or high deciduous forest cover), spiders, opilionids and dipterans were rather less abundant in these orchards. To conclude, our study points to the potential importance of predatory dipterans in apple orchards, and we highly recommend future studies of arthropod predators in apple and other crops to actively include predatory Diptera.

Stay-at-home tech's star turn: Even technophobes rely on consumer tech now

Remember March, when stay-at-home orders and advisories first went into effect in many U.S. states and other places around the world? That month is generally not a big time for consumer electronics sales; gadgets may fly off shelves during the December holiday season, but then there's a bit of a lull.

HIGH TEMPERATURES AND THEIR EFFECTS ON PLANTS AND BEES

The analysis of the effect of high ambient temperatures on entomophilous plants and honey bees is carried out. The research of the species composition of entomophilous plants, the timing of their flowering, of the temperature peaks during the summer was conducted in accordance with the conditions of the Fergana region, Uzbekistan. The ethological behavior of bees at high temperatures was carried out at Holosiivska educational and research apiary of NULES of Ukraine. Trere were used generally accepted methods at experiments. According to the research results, the maximum ambient temperatures for Fergana, Uzbekistan were determined. It is established that according to conditions of the Fergana region of Uzbekistan, honey plants and bees are most exposed to high temperatures during the second half of summer. It was analyzed the species variety of entomophilous plants of the Fergana Valley. The most common species of plants by areas of their dissemination have been identified. Plants are grouped in each zone, subject to influence of high temperatures during their flowering period. The effects of heat on the flight activity of worker bees and their behavior are determined. During the day, under the influence of high temperatures, the bees of the families did not show the same activity to flying. They actively fly off in the morning. As the temperature increased, the number of departures was decreased. This often happened from 11 a.m. to 6 p.m. During this period, the aggressiveness of bees in the colonies increased. They more often visited drinking bowls and brought water. In addition, bees actively ventilated the nests. Some of them opened the nest and hung on the walls of the hive.Under prolonged exposure of high temperatures, worker bees hung in bunches on the walls of the hive even at night. This behavior of bees lasted until the temperature dropped to 28 C and below. Given to the negative impact of global warming on flora and fauna, it is increase the importance of honey bees as part of the biocenosis of wildlife, the likelihood of extinction of many species of plants and animals. It is concluded that it is necessary to improve the ecology, to deep research related to the effects of high temperatures on honey bees and entomophytic plants.