90 research outputs found
The wall paintings of Xenos Digenis in the Myrtia monastery in Aetolia (1491)
No full textThe author examines the frescoes printed in 1491 by Xenos Digenis from Mouchli of Arcadia in the Catholics of the Myrtia Monastery, near Myrtia of Aetolia. These are the best-presented frescoes by Digenis, who also signed the frescoes in the churches of Aghioi Pateres at Apano Floria of Chania, Crete (1470) and the Dormition of the Virgin at Palaia Frastana (Kato Meropi) of Pogoni Epirus (1470, 1491). […]Αντικείμενο της εν λόγω διατριβής είναι η μελέτη των τοιχογραφιών που ζωγράφισε το 1491 ο Ξένος Διγενής από το Μουχλί της Αρκαδίας στο καθολικό της Μονής Μυρτιάς στην Αιτωλία. Ο ίδιο ζωγράφος είναι γνωστός και για τις ενυπόγραφες τοιχογραφίες του στους Αγίους Πατέρες στα Απάνω Φλώρια Σέλινου στο Νομό Χανίων της Κρήτης (1470) και στην Κοίμηση της Θεοτόκου στα Παλαιά Φραστανά, (σημερινή Κάτω Μερόπη) στο Πωγώνι της Ηπείρου (1470, 1491). […
Optimal Wideband LPDA Design for Efficient Multimedia Content Delivery over Emerging Mobile Computing Systems
No full textAn optimal synthesis of a wideband Log-Periodic
Dipole Array (LPDA) is introduced in the present study. The LPDA optimization is performed under several requirements concerning the standing wave ratio, the forward gain, the gain flatness, the front-to-back ratio and the side lobe level, over a
wide frequency range. The LPDA geometry that complies with the above requirements is suitable for efficient multimedia content delivery. The optimization process is accomplished by applying a recently introduced method called Invasive Weed Optimization (IWO). The method has already been compared to other evolutionary methods and has shown superiority in solving complex non-linear problems in telecommunications and electromagnetics. In the present study, the IWO method has been chosen to optimize an LPDA for operation in the frequency range
800-3300 MHz. Due to its excellent performance, the LPDA can effectively be used for multimedia content reception over future mobile computing systems
Detekcija otkaza kotrljajnih ležajeva primenom naprednih vremensko-frekvencijskih metoda analize signala vibracija
No full textRezime:
Od samih početaka industrijske revolucije pojavila se potreba za što
efikasnijom i pre svega jeftinijom proizvodnjom proizvoda koja će pri tom imati
željeni visok nivo kvaliteta. U tu svrhu, kreiraju se sve brže i snažnije mašine
i mehanizmi, koji postaju sve kompleksniji, a samim tim izloženiji višim
nivoima opterećenja. Kao rezultat toga mašine su sve više izložene
kompleksnijim tipovima oštećenja i/ili otkazima koji direktno utiču na njihovu
pouzdanost, raspoloživost i bezbednost pri korišćenju. Takvu opremu srećemo u
finansijski i tehnički posebno kritičnim oblastima kao što su: procesi obrade,
transportni sistemi, električna i elektronska oprema, elektroenergetski
sistemi, a u novije vreme su to sistemi za proizvodnju obnovljive energije.
Rotacione mašine spadaju u klasu najčešće korišćenih tehničkih sistema, za
koje se često zahteva kompletna i precizna dokumentacija o vibracionim
karakteristikama, uključujući merenja neophodna kako bi se izvršila analiza
vibracija vratila, kućišta i kotrljajnih ležajeva. Kotrljajni ležajevi,
reduktori i rotori su ključne i neizostavne komponente rotacionih mašina.
Samim tim, stanje ovih ključnih komponenata ujedno određuje i stanje same
rotacione mašine.
U disertaciji se proučava primena postprocesionih metoda izdvajanja spektra iz
signala vibracija, kako bi se detektovala oštećenja kotrljajnih ležajeva.
Kotrljajni ležajevi su osnovne komponente rotacionih mašina. Oštećenja
kotrljajnih ležajeva su odgovorna za značajan deo otkaza mašina. Samim tim
otkrivanje oštećenja kotrljajnih ležajeva je važno za poboljšanje pouzdanosti i
performansi mehaničkih sistema.
Iako su kotrljajni ležajevi detaljno proučavani tokom prethodnih decenija što
je prikazano u dostupnoj literaturi, u ovoj disertaciji je predstavljena
inovativna primena vremensko–frekvencijske metode za analizu, tzv. metode
kompletne ansambalske empirijske dekompozicije na modove sa adaptivnim
šumom (eng. Complete Ensemble Empirical Mode Decomposition with Adaptive Noise –
CEEMDAN) i Zao–Atlas–Markove raspodele (ZAMD). Pomenutim metodama se
prevazilaze poznata ograničenja metode razlaganja signala na funkcije (eng.
Empirical Mode Decomposition – EMD), u pogledu mešanja modova i izdvajanja
frekvencija. Glavni cilj disertacije je istraživanje sposobnosti ovih metoda za
otkrivanje oštećenja u početnoj fazi. Za procenu metoda, koriste se kotrljajni
ležajevi sa poznatim lokalizovanim oštećenjima, u cilju dobijanja skupa
podataka sa eksperimentalnog postrojenja koje simulira rotacionu mašinu. Isto
tako, upotrebljavaju se i podaci iz literature kao drugi test. Dobijeni rezultati
potvrđuju sposobnost metode za otkrivanje degradacije kotrljajnih ležajeva.Abstract:
Since the industrial revolution, a need for faster, better quality and especially cheaper to
produce, products has emerged. So special tools, quick and powerful machines and
mechanisms were created, and tend to become increasingly complex, thus subject to a
corresponding complex damage and / or failures affecting the reliability, availability and
safety of operation. Such equipment’s are found in particularly critical financial and
technical fields such as machining processes, production, transport systems, electrical and
electronic equipment and power systems (and, recently, renewable energy). Rotating
machinery is one of the most common classes of machines, often requires complete and
accurate documentation of vibration characteristics including measurements for shaft,
housing and rolling bearings vibration analysis. Rolling bearings, gears and rotors are the
common and key components in rotating machinery. The health condition of these key
components represents that of the machine itself.
The present dissertation introduces investigates the application of a post-processing
method of extracting spectra from vibration signals in order to detect faults of rollingelement
bearings. Rolling-element bearings are fundamental components of rotating
machinery. Faults of rolling-elements bearings are responsible for a substantial
proportion of machine failures and therefore fault detection is important for improving
the mechanical system reliability and performance. Although rolling bearings have been
investigated in detail in past studies, innovative applications of time-frequency analysis
method, called complete ensemble empirical mode decomposition with adaptive noise
(CEEMDAN) and Zhao Atlas Marks Distribution (ZAMD), that overcomes known
limitations concerning mode mixing and frequency separation of empirical mode
decomposition are presented. The main aim of the presented dissertation is to investigate
the ability of the methods to detect faults in early stage. To validate the methods, rollingelement
bearings with known and localized faults are used in order to acquire datasets
from an experimental rig that stimulates rotating machinery. Also datasets from literature
are used as second trial. The results verify the ability of the method to detect degradations
of rolling-element bearings.
The present dissertation consists of six experimental studies and one industrial case study,
where the first one was concerned with investigation and validation of the experimentalrig
in relation to its dimensions and construction accuracy and the second one concerned
the validation and selection of mounting pads in order to isolate the experimental-rig from
external stimulations and the calculation of their mechanical properties. The four
remaining experimental studies were concerned with investigation and validation of
advanced signal processing methodologies for their ability to detect external stimulations
and to detect faults in early stage in rolling- element bearings. At last an industrial case
study was conducted in order to validate the method in real working environment
Detekcija otkaza kotrljajnih ležajeva primenom naprednih vremensko-frekvencijskih metoda analize signala vibracija
No full textRezime:
Od samih početaka industrijske revolucije pojavila se potreba za što
efikasnijom i pre svega jeftinijom proizvodnjom proizvoda koja će pri tom imati
željeni visok nivo kvaliteta. U tu svrhu, kreiraju se sve brže i snažnije mašine
i mehanizmi, koji postaju sve kompleksniji, a samim tim izloženiji višim
nivoima opterećenja. Kao rezultat toga mašine su sve više izložene
kompleksnijim tipovima oštećenja i/ili otkazima koji direktno utiču na njihovu
pouzdanost, raspoloživost i bezbednost pri korišćenju. Takvu opremu srećemo u
finansijski i tehnički posebno kritičnim oblastima kao što su: procesi obrade,
transportni sistemi, električna i elektronska oprema, elektroenergetski
sistemi, a u novije vreme su to sistemi za proizvodnju obnovljive energije.
Rotacione mašine spadaju u klasu najčešće korišćenih tehničkih sistema, za
koje se često zahteva kompletna i precizna dokumentacija o vibracionim
karakteristikama, uključujući merenja neophodna kako bi se izvršila analiza
vibracija vratila, kućišta i kotrljajnih ležajeva. Kotrljajni ležajevi,
reduktori i rotori su ključne i neizostavne komponente rotacionih mašina.
Samim tim, stanje ovih ključnih komponenata ujedno određuje i stanje same
rotacione mašine.
U disertaciji se proučava primena postprocesionih metoda izdvajanja spektra iz
signala vibracija, kako bi se detektovala oštećenja kotrljajnih ležajeva.
Kotrljajni ležajevi su osnovne komponente rotacionih mašina. Oštećenja
kotrljajnih ležajeva su odgovorna za značajan deo otkaza mašina. Samim tim
otkrivanje oštećenja kotrljajnih ležajeva je važno za poboljšanje pouzdanosti i
performansi mehaničkih sistema.
Iako su kotrljajni ležajevi detaljno proučavani tokom prethodnih decenija što
je prikazano u dostupnoj literaturi, u ovoj disertaciji je predstavljena
inovativna primena vremensko–frekvencijske metode za analizu, tzv. metode
kompletne ansambalske empirijske dekompozicije na modove sa adaptivnim
šumom (eng. Complete Ensemble Empirical Mode Decomposition with Adaptive Noise –
CEEMDAN) i Zao–Atlas–Markove raspodele (ZAMD). Pomenutim metodama se
prevazilaze poznata ograničenja metode razlaganja signala na funkcije (eng.
Empirical Mode Decomposition – EMD), u pogledu mešanja modova i izdvajanja
frekvencija. Glavni cilj disertacije je istraživanje sposobnosti ovih metoda za
otkrivanje oštećenja u početnoj fazi. Za procenu metoda, koriste se kotrljajni
ležajevi sa poznatim lokalizovanim oštećenjima, u cilju dobijanja skupa
podataka sa eksperimentalnog postrojenja koje simulira rotacionu mašinu. Isto
tako, upotrebljavaju se i podaci iz literature kao drugi test. Dobijeni rezultati
potvrđuju sposobnost metode za otkrivanje degradacije kotrljajnih ležajeva.Abstract:
Since the industrial revolution, a need for faster, better quality and especially cheaper to
produce, products has emerged. So special tools, quick and powerful machines and
mechanisms were created, and tend to become increasingly complex, thus subject to a
corresponding complex damage and / or failures affecting the reliability, availability and
safety of operation. Such equipment’s are found in particularly critical financial and
technical fields such as machining processes, production, transport systems, electrical and
electronic equipment and power systems (and, recently, renewable energy). Rotating
machinery is one of the most common classes of machines, often requires complete and
accurate documentation of vibration characteristics including measurements for shaft,
housing and rolling bearings vibration analysis. Rolling bearings, gears and rotors are the
common and key components in rotating machinery. The health condition of these key
components represents that of the machine itself.
The present dissertation introduces investigates the application of a post-processing
method of extracting spectra from vibration signals in order to detect faults of rollingelement
bearings. Rolling-element bearings are fundamental components of rotating
machinery. Faults of rolling-elements bearings are responsible for a substantial
proportion of machine failures and therefore fault detection is important for improving
the mechanical system reliability and performance. Although rolling bearings have been
investigated in detail in past studies, innovative applications of time-frequency analysis
method, called complete ensemble empirical mode decomposition with adaptive noise
(CEEMDAN) and Zhao Atlas Marks Distribution (ZAMD), that overcomes known
limitations concerning mode mixing and frequency separation of empirical mode
decomposition are presented. The main aim of the presented dissertation is to investigate
the ability of the methods to detect faults in early stage. To validate the methods, rollingelement
bearings with known and localized faults are used in order to acquire datasets
from an experimental rig that stimulates rotating machinery. Also datasets from literature
are used as second trial. The results verify the ability of the method to detect degradations
of rolling-element bearings.
The present dissertation consists of six experimental studies and one industrial case study,
where the first one was concerned with investigation and validation of the experimentalrig
in relation to its dimensions and construction accuracy and the second one concerned
the validation and selection of mounting pads in order to isolate the experimental-rig from
external stimulations and the calculation of their mechanical properties. The four
remaining experimental studies were concerned with investigation and validation of
advanced signal processing methodologies for their ability to detect external stimulations
and to detect faults in early stage in rolling- element bearings. At last an industrial case
study was conducted in order to validate the method in real working environment
DOPPLER SHIFT INVESTIGATION OF AN IONOSPHERIC F2-LAYER RADIOWAVE
No full textTHE PURPOSE OF THIS INVESTIGATION WAS THE EXPERIMENTAL EVALUATION OF THE DOPPLER SHIFTS OF AN IONOSPHERIC F2-LAYER RADIO-LINK. THE RESULTS OBTAINED FROM THIS EXPERIMENTAL EVALUATION WERE: (I) THE DOPPLER SHIFTS VARY BETWEEN 0.2-0.8HZ (II) THE STRONGEST COMPONENT OF A MULTI-MODE SPECTRUM IS THE ONE THAT CORRESPONDS TO 1F2 (III) THE ANALYSIS OF THE DOPPLER SHIFT TIME SERIES HAS SHOWN TWO MAIN SPECTRAL COMPONENTS WITH PERIODS 180 AND 70 MIN RESP. (IV) THE PERIOD OF THE LARGE PERIOD COMPONENT HAS A MAXIMUM IN SUMMER AND A MINIMUM IN WINTER, WHILE THE SMALL PERIOD COMPONENT IS ALMOST ALWAYS CONSTANT (V) THE AMPLITUDES OF BOTH COMPONENTS SHOW A MAXIMUM IN WINTER AND A MINIMUM IN SUMMER; THEAMPLITUDE OF THE SMALL PERIOD COMPONENT IS ALWAYS -3DB WITH RESPECT TO THE AMPLITUDE OF THE LARGE PERIOD COMPONENT (VI) THESE IONOSPHERIC OSCILLATIONS ARE CONSIDERED AS GRAVITY WAVE PROPAGATION EFFECT ON THE IONOSPHERIC HEIGHTS. FINALLY A SIMULATION WAS ATTEMPTED SUCCESSFULLY.ΣΚΟΠΟΣ ΤΗΣ ΕΡΓΑΣΙΑΣ ΑΥΤΗΣ ΗΤΑΝ Η ΠΕΙΡΑΜΑΤΙΚΗ ΑΞΙΟΛΟΓΗΣΗ ΤΩΝ ΜΕΤΑΤΟΠΙΣΕΩΝ DOPPLER ΡΑΔΙΟΚΥΜΑΤΟΣ, ΤΟ ΟΠΟΙΟ ΔΙΑΔΙΔΕΤΑΙ ΔΙΑ ΤΟΥ ΙΟΝΟΣΦΑΙΡΙΚΟΥ ΣΤΡΩΜΑΤΟΣ F2 ΣΤΗ ΡΑΔΙΟΖΕΥΞΗ BIRMINGHAM-ΘΕΣ/ΝΙΚΗΣ. ΤΑ ΣΗΜΑΝΤΙΚΟΤΕΡΑ ΣΥΜΠΕΡΑΣΜΑΤΑ ΤΟΥ ΠΕΙΡΑΜΑΤΙΚΟΥ ΤΜΗΜΑΤΟΣ ΤΗΣ ΕΡΕΥΝΑΣ ΗΤΑΝ: (I) ΟΙ ΜΕΤΑΤΟΠΙΣΕΙΣ DOPPLER ΕΙΝΑΙ ΣΤΗΝ ΠΕΡΙΟΧΗ 0.2:0.8HZ (II) ΣΕ ΦΑΣΜΑ ΜΕ ΠΟΛΛΟΥΣ ΡΥΘΜΟΥΣ ΔΙΑΔΟΣΗΣ Η ΙΣΧΥΡΟΤΕΡΗ ΦΑΣΜΑΤΙΚΗ ΣΥΝΙΣΤΩΣΑ ΑΝΤΙΣΤΟΙΧΕΙ ΣΤΟΝ 1F2 (III) Η ΑΝΑΛΥΣΗ ΤΩΝ ΧΡΟΝΟΣΕΙΡΩΝ ΤΩΝ Μ.D. ΑΝΕΔΕΙΞΕ ΔΥΟ ΚΥΡΙΕΣ ΣΥΝΙΣΤΩΣΕΣ ΜΕ ΜΕΣΕΣ ΕΤΗΣΙΕΣ ΠΕΡΙΟΔΟΥΣ 180 MIN ΚΑΙ 70 MIN (IV) Η ΠΕΡΙΟΔΟΣ ΤΗΣ ΜΕΓΑΛΗΣ ΠΕΡΙΟΔΟΥ ΠΑΡΟΥΣΙΑΖΕΙ ΜΕΓΙΣΤΟ ΤΟ ΚΑΛΟΚΑΙΡΙ ΚΑΙ ΕΛΑΧΙΣΤΟ ΤΟ ΧΕΙΜΩΝΑ, ΕΝΩ Η ΑΝΤΙΣΤΟΙΧΗ ΤΗΣ ΜΙΚΡΗΣ ΕΙΝΑΙ ΣΧΕΔΟΝ ΣΤΑΘΕΡΗ (V) ΤΑ ΑΝΤΙΣΤΟΙΧΑ ΠΛΑΤΗ ΜΕΓΙΣΤΟΠΟΙΟΥΝΤΑΙ ΤΟ ΧΕΙΜΩΝΑ ΚΑΙ ΕΛΑΧΙΣΤΟΠΟΙΟΥΝΤΑΙ ΤΟ ΚΑΛΟΚΑΙΡΙ, ΕΝΩ ΤΟ ΠΛΑΤΟΣ ΤΗΣ ΣΥΝ. ΜΙΚΡΗΣ ΠΕΡΙΟΔΟΥ ΕΙΝΑΙ ΠΑΝΤΑ -3DB ΣΕ ΣΧΕΣΗ ΜΕ ΤΗΣ ΜΕΓΑΛΗΣ (VI) ΟΙ ΙΟΝΟΣΦΑΙΡΙΚΕΣ ΑΥΤΕΣ ΤΑΛΑΝΤΩΣΕΙΣ ΘΕΩΡΕΙΤΑΙ ΟΤΙ ΕΙΝΑΙ ΑΠΟΤΕΛΕΣΜΑΤΑ ΔΙΑΔΟΣΕΩΣ ΚΥΜΑΤΩΝ ΒΑΡΥΤΗΤΑΣ ΣΕ ΙΟΝΟΣΦΑΙΡΙΚΑ ΥΨΗ. ΤΕΛΟΣ ΕΓΙΝΕ ΚΑΙ ΠΡΟΣΠΑΘΕΙΑ ΠΡΟΣΟΜΟΙΩΣΗΣ ΜΕ ΑΡΚΕΤΗ ΕΠΙΤΥΧΙΑ
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The World Is Plural: Democratic Contributions Of Hannah Arendt
No full textDrawing on seminal texts and lesser known works, this dissertation brings the political theory of Hannah Arendt into the company of several key debates in democratic theory. Though she is most renowned for her theory of political action, it is my contention that Arendt's concept of World can productively change the very terms by which democratic politics is most often understood and questioned. World, in this case, refers to physical and symbolic matters of commonality that are constructed by and for humans. This project begins with a genealogy of that traces its development of World through Arendt's own biography including her experience as a female philosopher decades before the feminist movement, German Jewish refugee, and immigrant living in the United States. The following chapter explores the shortcomings of Arendt's concept of political action, arguing in particular that it limits and forecloses democratic political possibilities. The third chapter brings World to bear on the question of whether unity or difference is necessary for the consolidation of the demos, a well-mined debate in democratic theory that the conceptual terms of World can alter and amend. The final section uses the concept of World to contest the popular depiction of globalization that Thomas Friedman champions in his well known works. This is in service of an argument that World can offer a productive critique of the destructive aspects of globalization, particularly the narrative of capitalist inevitability that often undergirds them.Political ScienceDoctor of Philosophy (Ph.D.
Xenos: Uma análise de Xenofeminismo e de Xenogenesis
No full text“Xeno” is a prefix that means strange or foreign and was used by the xenofeminists in order to think a futuristic feminism that stood for a radical alienation, for becoming an Other. Constructing liberty would only happen by accepting this natural condition of alien[ation] and reinforcing it, becoming alien[ated] before the world. For this reason, the movement incorporates some principles, amongst which we may consider the fundamental: tecnomaterialism, antinaturalism, and gender abolitionism. This work has the objective of allying the xenofeminist proposal with science-fiction author Octavia Butler’s ideas, in order to discuss the similarities the feminist project has with the Xenogenesis work by the American author. Xenogenisis means “generation from the strange/alien”, and this sci-fi brings to light, current discussions about reproduction and its technologies, gender issues and racism. It is intended not only to show the book’s symbolic but also literal alien influence on the Cuboniks’ colective movement, and also to debate the issues that Butler’s work raises and that may be incorporated to the xenofeminist discussion.O prefixo “xeno” que significa estranho ou estrangeiro foi utilizado pelas xenofeministas para pensar um feminismo para o futuro em defesa da alienação radical, do tornar-se Outro. Construir a liberdade se daria apenas aceitando essa condição natural de alien[ação] e reforçando-a, tornando-se alien[ado] perante o mundo. Por esse motivo, o movimento incorpora alguns princípios, dentre os quais podemos considerar os principais: o tecnomaterialismo, antinaturalismo e o abolicionismo de gênero. Este trabalho tem como objetivo aliar a proposta do xenofeminismo com as ideias da autora de ficção científica Octavia Butler, para discutir as similaridades que o projeto feminista possui com a obra Xenogenesis da autora americana. Xenogenesis significa “geração a partir do estranho/alien”, e, esse livro de sci-fi traz à tona, de maneira atual, discussões sobre reprodução e suas tecnologias, questões de gênero e racismo. Pretende-se não só mostrar a influência que o livro sobre alienígenas produziu simbólica e literalmente no movimento do coletivo Cuboniks, mas também debater pontos que Butler suscita em sua obra que podem ainda ser incorporados à discussão do xenofeminismo
Distribution of Four Vole Species through the Barn Owl Tyto alba Diet Spectrum: Pattern Responses to Environmental Gradients in Intensive Agroecosystems of Central Greece
No full textVoles are the most common vertebrate pests in European agriculture. Identifying their distribution and abundance patterns provides valuable information for future management. Barn Owl diet analysis is one of the optimum methods used to record small mammal distribution patterns on large spatial scales. From 2003 to 2005, a total of 10,065 Barn Owl pellets were collected and analyzed from 31 breeding sites in the largest agroecosystem in Greece, the Thessaly plains. A total of 29,061 prey items were identified, offering deep insight into small mammal distribution, specifically voles. Four discrete vole species (Harting’s vole Microtus hartingi, East European vole Microtus levis, Thomas’s pine vole Microtus thomasi, and Grey dwarf hamster Cricetulus migratorius) comprised 40.5% (11,770 vole prey items) of the total Barn Owl prey intake. The presence and abundance of the voles varied according to underlying environmental gradients, with soil texture and type playing a major role. M. levis showed no significant attachments to gradients, other than a mild increase in Mollisol soils. It was syntopic in all sites with M. hartingi, which was the dominant and most abundant small mammal species, preferring non-arable cultivated land, natural grasslands, set-aside fields, and fallow land. M. thomasi was strictly present in western Thessaly and strongly associated with a sandy-clay soil texture and Alfisol soils. C. migratorius was the least represented vole (162 items), exclusively present in eastern Thessaly and demonstrating a stronger association with cereals, Mollisol soils, and an argillaceous-clay soil texture. This is the first study in Greece at such a large spatial scale, offering insights for pest rodents’ distribution in intensive agroecosystems and their response to environmental gradients including soil parameters
Have female twisted-wing parasites (Insecta: Strepsiptera) evolved tolerance traits as response to traumatic penetration?
No full textTraumatic insemination describes an unusual form of mating during which a male penetrates the body wall of its female partner to inject sperm. Females unable to prevent traumatic insemination have been predicted to develop either traits of tolerance or of resistance, both reducing the fitness costs associated with the male-inflicted injury. The evolution of tolerance traits has previously been suggested for the bed bug. Here we present data suggesting that tolerance traits also evolved in females of the twisted-wing parasite species Stylops ovinae and Xenos vesparum. Using micro-indentation experiments and confocal laser scanning microscopy, we found that females of both investigated species possess a uniform resilin-rich integument that is notably thicker at penetration sites than at control sites. As the thickened cuticle does not seem to hamper penetration by males, we hypothesise that thickening of the cuticle resulted in reduced penetration damage and loss of haemolymph and in improved wound sealing. To evaluate the evolutionary relevance of the Stylops-specific paragenital organ and penis shape variation in the context of inter- and intraspecific competition, we conducted attraction and interspecific mating experiments, as well as a geometric-morphometric analysis of S. ovinae and X. vesparum penises. We found that S. ovinae females indeed attract sympatrically distributed congeneric males. However, only conspecific males were able to mate. In contrast, we did not observe any heterospecific male attraction by Xenos females. We therefore hypothesise that the paragenital organ in the genus Stylops represents a prezygotic mating barrier that prevents heterospecific matings
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