514 research outputs found
The Δρομοδείχτης της Ελλάδος of 1824 and Athanasios Stageirites (Τίτλος περίληψης)
No full textσ. [281]-290Κείμενο στα ελληνικά με περίληψη στα αγγλικά με τον τίτλο: The Δρομοδείχτης της Ελλάδος of 1824 and Athanasios StageiritesThe article first examines the close relationship between the publication “Δρομοδείχτης της Ελλάδος” [1824] and the publication “Ηπειρωτικά” (1819) by Athanasios Stageirites and then suggests that Athanasios Stageirites is the likeliest author of the “Δρομοδείχτης της Ελλάδος”.Δωδώνη: Τεύχος Πρώτο: επιστημονική επετηρίδα του Τμήματος Ιστορίας και Αρχαιολογίας της Φιλοσοφικής Σχολής του Πανεπιστημίου Ιωαννίνων; Τόμ. 43-44 (2014-2015
Biosystematic studies on the Muellerianella complex (Delphacidae Homoptera Auchenorrhyncha)
No full textThe genus Muellerianella comprises the species: M. farmairei, M. brevipennis, M. relicta and one pseudogamous all-female biotype M. fairmairei (3n). The bisexual species M. fairmairei and M. brevipennis as well as the unisexual M. fairmairei (3n) were investigated from a biosystematic point of view. The males of the two bisexual species are morphologically distinct but their females, the female hybrids of both way-crossings between the two bisexual species and the unisexual biotype are morphologically indistinguishable.The bisexual species M. fairmairei and M. brevipennis are diploid (2n = 28) and their sex determination system is XY. F1 hybrids also have 28 chromosomes. The pseudogamous unisexual biotype is triploid (3n = 41) reproducing apomictically, but it requires sperm derived from the males of the two bisexual species to initiate embryogenesis (pseudogamy).The host plants of the Muellerianella complex are Holcuslanatus or H.mollis for the bisexual and unisexual M. fairmairei, and Deschampsia caespitosa for M. brevipennis.The distributions of the two species and their host plants overlap widely in West and Central Europe. M. fairmairei and its host plant are distributed more to the south, while M. brevipennis and its host extend more to the north. There is evidence that the unisexual M. fairmairei (3n) occurs in the overlapping area of the two bisexual species, but is absent from the peripheral areas where one of the other species is also absent.In the area of Leersum-Langbroek (prov. of Utrecht) in Holland both species are common, and their respective host plants grow in reasonable numbers. In a few localities where the two hosts are closely intermixed both delphacid species occur syntopically.Samples of the two species were taken bij the sweep-net and suction methods. M. fairmairei is more frequent in wet biotopes of noncultivated meadows in West Europe. M. brevipennis is more frequent in the north of Europe and is a stenotopic species typical of fresh biotopes of wooded areas.In Northern Europe both species are univoltine while in West and Central Europe M. fairmairei has two distinct generations in contrast to M. brevipennis which has an incomplete second generation. However, there is no important seasonal isolation between the two species. In Southern Europe M. fairmairei is probably polyvoltine.Populations of M. fairmairei from regions where M. brevipennis does not occur (S. Greece, S. France?, Ireland) have a sex ratio of 1 : 1, while populations occurring sympatrically with M. brevipennis (England, France, Holland) have a high proportion of females, comprising a mixture of diploid and triploid individuals. In Holland M. brevipennis has a sex ratio of1 : 1, while populations of this species in Finland have a high proportion of females.Both diploid species maintained a 1:1 sex ratio in the laboratory rearings. Crossings between triploid females and males of M. fairmairei resulted in absolute all-female triploid progenies. Diploid and triploid females of M. fairmairei coexist in Holland. In one biotope (in Leersum), the proportion of the two female biotypes of M.fairmairei was 1:1, while in others triploid females were more numerous than the diploid ones. It is not clear, whether both female populations of M. fairmairei occupy exactly the same ecological niche.Regarding the wing form of the two bisexual species and the unisexual biotope, long photoperiod (L:D = 18:6) favors the development of the long wings, while short photoperiod (L:D = 10:14) completely suppresses it. Under long photoperiod the macropterous form of M. brevipennis was more common than that of M. fairmairei. Under long photoperiod, when the larval density was increased M. fairmairei (2n) had proportionately more macropterous adults than M. fairmairei (3n).Summer and winter eggs of the two species were parasitized by Anagrus sp. However, eggs of the second generation were more frequently parasitized (up to 40%) that those of the first.The higher population densities of M. fairmairei than of M. brevipennis in the field were interpreted from laboratory observations by the fact that M. fairmairei has higher egg production than M. brevipennis. The triploid females of M. fairmairei are assumed to be more prolific than the diploid ones. Also, the rate of egg production of M. fairmairei was higher than that of M. brevipennis. Females of M. fairmairei mated once produced a few unfertile eggs at the end of their oviposition period, in contrast to M. brevipennis which always produced fertile eggs. Males of M. fairmairei appeared to have greater longevity than the females.During the first generation and in colonies under long photoperiod M. fairmairei oviposits in its food plant H. lanatus, while during the second generation and in colonies under short photoperiod in Juncus effusus. M. brevipennis was found to oviposit in the field only in its food plant, namely D. caespitosa, but in the laboratory it also oviposited in J. effusus. The egg-group size of both species depends upon the oviposition substrate.Embryonic development of both species is continuous during the first generation and in colonies under long photoperiod, but embryonic diapause (arrest of development before blastokinesis) takes place during the second generation and in laboratory rearings under short photoperiod. The intensity of diapause is higher in M. brevipennis as compared to M. fairmairei. Continuous rearings of the unisexual and bisexual M. fairmairei were possible under short photoperiod.The rate of larval development of both species under long photoperiod at 20- 25°C was approximately the same. Under short photoperiod the duration of the last instar larva of females is longer than that under long photoperiod. Temperature, humidity and crowding had an influence upon the rate of larval development.In laboratory experiments, development and reproduction of M. fairmairei occurred on several grass species, in contrast to M. brevipennis which appeared to be monophagous. Mature grasses were more suitable as food plants than seedlings.Some unmated females of M. fairmairei (2n) placed in cages containing H. lanatus and D. caespitosa, and males of M. brevipennis ultimately produced a few male and female hybrids. The reciprocal cross resulted in more female hybrids than males. Egg-fertility of these crosses was variable (0-100%) during the course of the oviposition period. Hybrid larvae can develop on both grass species, but they prefer D. caespitosa to H. lanatus. Males were sterile but females were often fertile and some of them crossed back with M. fairmairei produced a triploid pseudogamous biotype very similar to that collected in the field. The all-female progeny of the triploid M. fairmairei was greater when it was crossed with M. fairmairei males than with M. brevipennis males. Hybrids were obtained even when unmated females (2n + 3n) of both species together were caged with males of one species.In conformity with these results it is proposed that the two bisexual species should be called 'allomorphic-related species' instead of 'sibling species'. Allopatric speciation is considered as the most probable cause of divergence between both species. It is suggested that M. brevipennis originated from an isolated population of M. fairmairei during a period of glaciation and has survived on D. caespitosa.It is proposed to call the unisexual biotype M.2 fairmairei-brevipennis, following the nomenclatorial system of hybrids. In this context, it has been demonstrated that in insects hybridization may lead to unisexuality followed by polyploidy.<br/
Dataset in support of the Southampton doctoral thesis 'The boatbuilding tradition of the Aegean during the Late Neolithic – Early Bronze Age periods. Typological classification, digital reconstruction and seakeeping assessment'
No full textDataset in support of the Southampton doctoral thesis 'The boatbuilding tradition of the Aegean during the Late Neolithic – Early Bronze Age periods. Typological classification, digital reconstruction and seakeeping assessment' Appendix D - Resistance data and Appendix C - Stability data.
This dataset is focused on two appendices:
Appendix D - Resistance data. D.1 Resistance data produced by the author via MAXSURF Resistance for this thesis.
Appendix C - Stability data
C1. Stability data – STIX and ISO criteria, produced by the author via MAXSURF Stability software for his thesis
This research was funded by Southampton Marine and Maritime Institute (SMMI), Vice-Chancellor's Scholarship, Greek Archaeological Committee UK (GACUK)
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Peak power reduction algorithms in asymmetric digital subscriber line modems
No full textThesis (M.Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2000.Includes bibliographical references (leaves 94-96).This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.This thesis investigates peak-to-average ratio (PAR) reduction techniques for multicarrier modulation systems, such as discrete multitone (DMT) modems and orthogonal frequency-division multiplexed (OFDM) terrestrial broadcast transmitters. Through simulation and test implementation on a state-of-the-art programmable ADSL development platform, this thesis pursues a suitable solution for minimizing PAR given the resources of a programmable platform. This solution is integrated as a prototype implementation into a fully-functional ADSL modem and optimized for maximum PAR reduction performance within modem complexity constraints.by Athanasios Dimitri Dousis.M.Eng
Homophobic Statements, a Bishop, and the Limits of Freedom of Expression. An In-Depth Commentary on ECtHR 31.08.2023, Amvrosios-Athanasios Lenis v. Greece, no. 47833/20
No full textDichiarazioni omofobe, un vescovo e i limiti della libertà di espressione. Un commento approfondito su CEDU 31.08.2023, Amvrosios-Athanasios Lenis v. Greece, no. 47833/20.
ABSTRACT: The decision of the ECtHR of 31.08.2023, Amvrosios-Athanasios Lenis v. Greece (no. 47833/20), is a further step toward an increasingly dense jurisprudence on “hate speech” and the limits of freedom of expression. The public proclamation of religious doctrines that are in conflict with the values of the contracting States enshrined in the ECHR is protected to a certain extent by the fundamental right of freedom of religion and belief. However, the qualification of a statement as religious does not justify “hate speech.” The AUTHOR shows the tension between freedom of religion, freedom of expression, and protection against discrimination, and analyzes the decision against the backdrop of Article 17 of the ECHR (prohibition of abuse of rights).
SOMMARIO: 1. Preliminary Remarks - 2. The Concept of Hate Speech - 3. The Facts of the Case - 4. The Procedure and Reasoning of the Court - 4.1 The ECtHR’s Preliminary Considerations on Fundamental Rights - 4.2 Legal assessment - 4.3 Some Remarks on (the Non-Invoked) Article 9 of the ECHR - 5. Concluding Remarks
La tomba III di Haghios Athanasios e il valore semantico dell'incarnato
No full textThe tomb III at Haghios Athanasios stands out among the Macedonian tombs for the exceptional painted decoration of the temple-like façade. Excavated in the '90s by M. Tsimbidou-Avloniti it has been published by the scholar in full detail and the iconographic program of the monument has been the object of many publications. This article re-examines the different ways of reproducing the skin color (το ανδρείκελον) in the figures of the miniature frieze and in the megalographic figures beside the door. The realistic rendering of the megalographic figures of armed men in Macedonian attire, showing their sorrow for the lost of an etairos, is contrasting with the pale color of the participants to the symposion in the frieze above the door, a scene whose illusionistic overtone has been yet perceived by the critics. This symposion is articulated in three scenes and it can be interpeted as a necrodeipnon, but in the same time as a celebration of the Macedonian banquet style, centered on the royal court. The author suggests that the first figure on the right of the frieze, related to the group of armed men looking towards the banqueters feasting in the center of the frieze, can be read as the dead himself, for the particular rendering of his ανδρείκελον, showing the typical ochròtes or necròdes face color, according to the contemporary medical lexicon. The pathetic stance assumed by the same figure, the sole in the group which is not bearing arms, seems to confirm his role in the context of the scene
Computational Modelling of Compaction in Asphaltic Mixtures and Geomaterials
No full textAsphaltic mixtures are heterogeneous composite materials consisting of aggregates coated and bound by asphalt binder. The long term performance of asphaltic pavements is highly dependent on the mechanical behaviour of the asphaltic mixture during construction (mixing and compaction) and operation; inadequate mixture compaction leads to faster moisture and oxygen diffusion, ravelling, rutting and poor fatigue life
Moisture damage susceptibility of asphalt mixtures: Experimental characterization and modelling
No full textA well-functioning, long-lasting and safe highway infrastructure network ensures the mobility of people and facilitates the transport of goods, promoting thus environmental, economic, and social sustainability. The development of sustainable highway infrastructure requires, among other activities, the construction of pavement systems with enhanced durability. Moisture damage in asphalt pavements is associated with inferior performance, unexpected failures and reduced service life. All of these contribute to the increase of operational and maintenance costs in order to fulfill the intended service life of the pavement system. Moreover, global warming and climate change events such as temperature extremes, high mean precipitation and rainfall intensity may further increase the probability and rate of pavement deterioration. This dissertation aims to obtain an advanced understanding of the influence of moisture on pavement durability by developing a set of tools, i.e. experimental methods and computational models, which will provide insight into the fundamental moisture damage processes and on their impact on pavement systems. Based on this knowledge, researchers and practitioners will be able not only to design pavements with increased resiliency, thereby providing reliable services to road users, but also to minimize the risks in the face of changing climate conditions.Moisture diffusion is well-known to degrade the mechanical properties of asphalt mortars, namely bitumen, filler and sand, thus increasing the propensity of pavements to cracking. To determine the changes in the cohesion properties of the mortar, uniaxial tension tests were performed. Mortar samples were prepared and then subjected to five combinations of moisture and thermal conditioning, in an attempt to reproduce the various conditioning states that pavements undergo in the field, before being tested. Tensile strength and fracture energy were used to evaluate the changes in mechanical properties due to the various conditioning protocols. To post-process the experimental data, a new data analysis procedure was suggested in order to obtain a more accurate calculation of fracture energy. The procedure uses nonlinear finite element analysis to specify the unloading response outside the fracture zone, and then utilizes this information to compute the fracture energy of the binders. This methodology yields a framework for the calculation of fracture energy when only force-displacement data are available and therefore the estimation of the true stress-strain curve is not feasible.The experimental investigation revealed the deteriorating impact of moisture on the fracture characteristics of asphalt mortars, especially as regards to their low temperature properties. These effects were not reversible upon drying. On the contrary, the application of a drying cycle caused embrittlement of the mortars and indicated that continuous wet and drying cycles in the field may result in materials with poor performance characteristics. Also, the application of freeze-thaw cycles was shown to increase the susceptibility of mortars to low temperature cracking. Nevertheless, on the whole, the effect of freeze-thaw on fracture properties was observed to depend on the conditioning state (dry or wet) and composition of the mortars. The use of additives, such as hydrated lime filler and SBS modifiers, were found to improve the wet strength and fracture energy of the mortars. On the basis of moisture uptake measurements, it was confirmed that the chemical composition influences significantly the diffusivity characteristics of the mortars. Also, the maximum moisture uptake was found to be the main parameter that dictates the intensity of mortar damage. In addition, moisture susceptibility was studied at mixture level. At this level, besides moisture diffusion, excess pore pressure can contribute to the degradation of mixture performance depending on the mixture type, the traffic loading and the environmental conditions. Hence, a moisture conditioning protocol that comprises two conditioning types, namely bath immersion and pore pressure application, was proposed for evaluating susceptibility of asphalt mixtures to moisture. Also, evidence was collected of the effect that dynamic pore pressure has on mixture degradation by means of X-ray computed tomography and image analysis techniques. The two damage mechanisms were found to be relatively independent from each other, suggesting that an asphalt mixture can be more prone to one damage mode than the other, depending on its composition. The proposed protocol captures both processes that occur when water interacts with a pavement and can provide more reliable conclusions with regard to mixture sensitivity.In order to improve our perception of the influence of material microstructures on moisture sensitivity of the asphalt composite, an energy-based elasto-visco-plastic model with softening was implemented to model damage due to the coupled effects of moisture diffusion and mechanical loading. The model consists of a generalized Maxwell model, with hyperelastic springs and viscous time-dependent components, in series with an inelastic component that accounts for the irreversible processes within the microstructure of the material. Then, a computational scheme was proposed by means of a staggered approach: first a three-dimensional diffusion model was applied to obtain information on the accumulation of moisture within the mixtures and then the elasto-visco-plastic model was used to quantify mortar damage due to moisture diffusion. This method was successfully applied to study the influence of mixture morphology on moisture sensitivity. The results demonstrated that moisture content in a mixture strongly depends on its morphology, whereas the interconnectivity of the voids network controls the rate of damage development. Also, the analysis revealed the positive effect of using binders with high resistivity against moisture and quantified the benefits that would arise due to this choice, especially when designing porous mixtures that have an intrinsic sensitivity to moisture due to their morphological characteristics.More broadly, frost damage can be classified as part of the moisture damage related mechanisms. In the field, frost damage can be mainly attributed to the expansion of water accumulated in the pores of the pavement at sub-zero temperatures that causes additional stresses to the pavement structure. A numerical scheme to simulate frost damage was proposed. This scheme comprises a model that simulates the volume expansion of water during the water-to-ice phase-change, a thermal conduction model to simulate temperature distribution in the pavement, and the elasto-visco-plastic model to determine critical areas with a propensity to cracking on the basis of the pavement stresses.In conclusion, this thesis contributes to establishing a relationship of the physico-mechanical properties of the constituent materials and mixture morphology with the moisture susceptibility of pavement structures. The proposed experimental methods and computational models can serve as tools to investigate a great variety of parameters before a pavement structure is actually built. This allows for new materials and mixture designs to be investigated and the risks involved with their use to be minimized.<br/
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