Investigation of a new steel-concrete connection for composite bridges

Dimitrios Papastergiou,Jean-Paul Lebet 국제구조공학회 2014 Steel and Composite Structures, An International J Vol.17 No.5

A new type of connection for steel-concrete composite bridges was developed by the Steel Structures Laboratory of Ecole Poytechinque Fédérale de Lausanne. Resistance to longitudinal shear is based on the development of shear stresses in the confined interfaces which form the connection. Confinement is provided by the reinforced concrete slab which encloses the connection and restrains the uplift (lateral separation) of the interfaces by developing normal stresses. The experimental investigation of the interfaces, under static and cyclic loading, enabled the development of the laws describing the structural behaviour of each interface. Those laws were presented by the authors in previous papers. The current paper focuses on the continuity of the research. It presents the experimental investigation on the new connection by means of push-out tests on specimens submitted to static and cyclic shear loading. Investigation revealed that the damage in the connection, due to cyclic loading, is expressed by the accumulation of a residual slip. A safe fatigue failure criterion is proposed for the connection which enabled the verification of the connection for the fatigue limit state with respect to the limit of fatigue. A numerical model is developed which takes into account the laws describing the interface behaviour and the analytical expressions for the confinement effect, the latter obtained by performing finite element analysis. This numerical model predicts the shear resistance of the connection and enables to assess its fatigue limit which is necessary for the fatigue design proposed.

The Unclear Legal Framework as a Deterring Parameter Of Developing Cave Tourism in Greece

( Dimitrios Mylonopoulos ),( Polyxeni Moira ),( Nikolaou Eleni ) 한국문화관광학회 2016 문화관광연구 Vol.18 No.2

Cave tourism is a special form of tourism, part of the broader category of geotourism. In Greece, despite the vast speleological wealth, the special and alternative form of cave tourism has not been exploited properly.This essay has been based on thorough research of the legal framework and case law that refer directly or indirectly to the protection of caves and the development of cave tourism. In addition, using websites of both state and private institutions as well as of speleological institutions, operating caves and their management bodies have been recorded. It appears that the complicated and unclear legal framework regulating ownership and supervision of caves in Greece contributes to their non-exploitation. The essay proposes the conduction of a new research to complete recording in a single database the existing exploited caves of the country, the setup of a "registry of exploited tourist caves" and the creation of a clear legislative framework that shall promote and exploit them. Furthermore, the inclusion of caves in regional tourism policy plans in order to achieve rational development of cave tourism in Greece.

Isolation and Production of Micro-Nanofibrillated Cellulose by using Aqueous Counter Collision

Dimitrios Tsalagkas,Le Van Hai,Lindong Zhai,Jeong Woong Kim,Jin Mo Kang,Jaehwan Kim 한국펄프·종이공학회 2016 한국펄프·종이공학회 학술발표논문집 Vol.2016 No.10

A machine learning approach for the condition monitoring of rotating machinery†

Dimitrios Kateris,Dimitrios Moshou,Xanthoula-Eirini Pantazi,Ioannis Gravalos,Nader Sawalhi,Spiros Loutridis 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.1

Rotating machinery breakdowns are most commonly caused by failures in bearing subsystems. Consequently, condition monitoring ofsuch subsystems could increase reliability of machines that are carrying out field operations. Recently, research has focused on the implementationof vibration signals analysis for health status diagnosis in bearings systems considering the use of acceleration measurements. Informative features sensitive to specific bearing faults and fault locations were constructed by using advanced signal processingtechniques which enable the accurate discrimination of faults based on their location. In this paper, the architecture of a diagnostic systemfor extended faults in bearings based on neural networks is presented. The multilayer perceptron (MLP) with Bayesian automatic relevancedetermination has been applied in the classification of accelerometer data. New features like the line integral and feature basedsensor fusion are introduced which enhance the fault identification performance. Vibration feature selection based on Bayesian automaticrelevance determination is introduced for finding better feature combinations.

Legal Policy for Sports Law in the EU

Dimitrios P. Panagiotopoulos 한국스포츠엔터테인먼트법학회 2008 스포츠와 법 Vol.11 No.4

Sport has been transformed into a major human activity and plays a leading role at an economic and social level in addition to the benefits it brings to the health of persons involved in sport. Special efforts must be made to ensure access to sports venues, infrastructure and activities for people with disabilities, and to ensure that their specific needs are taken into account, including at school and education systems. These elements of Sports Policy in the European Union reflect the constitutional protection of sportsmen regarding the fundamental rights of developing their personality, ensuring equal treatment, access to sports education and activities, protecting their health and social welfare. These provisions of the Lisbon Treaty alongside with the various national sports policies of the member states constitute the framework of protection of people involved in sports and give the opportunity for a new Legal Policy for the Sport in the EU. Sport has been transformed into a major human activity and plays a leading role at an economic and social level in addition to the benefits it brings to the health of persons involved in sport. Special efforts must be made to ensure access to sports venues, infrastructure and activities for people with disabilities, and to ensure that their specific needs are taken into account, including at school and education systems. These elements of Sports Policy in the European Union reflect the constitutional protection of sportsmen regarding the fundamental rights of developing their personality, ensuring equal treatment, access to sports education and activities, protecting their health and social welfare. These provisions of the Lisbon Treaty alongside with the various national sports policies of the member states constitute the framework of protection of people involved in sports and give the opportunity for a new Legal Policy for the Sport in the EU.

Safety of ovarian preservation in premenopausal women with stage I uterine sarcoma

Dimitrios Nasioudis,Eloise Chapman-Davis,Melissa Frey,Kevin Holcomb 대한부인종양학회 2017 Journal of Gynecologic Oncology Vol.28 No.4

Objective: To evaluate the oncologic safety of ovarian preservation (OP) in premenopausalwomen diagnosed with the International Federation of Gynecology and Obstetrics (FIGO)stage I uterine sarcoma. Methods: The National Cancer Institute's Surveillance, Epidemiology, and End Resultsdatabase was accessed and a cohort of women aged ≤50 diagnosed between 1988–2013 witha sarcoma limited to the uterus was drawn. Based on site-specific surgery codes, womenwho underwent hysterectomy with or without oophorectomy and did not receive radiationtherapy were selected for further analysis. Overall (OS) and cancer-specific (CSS) survivalwere determined following generation of Kaplan-Meier curves; comparisons were made withthe log-rank test. A Cox-proportional hazard model was constructed to control for possibleconfounders. Results: A total of 1,482 women were included in the analysis; 800 (54.0%) were diagnosedwith leiomyosarcoma (LMS), 520 (35.1%) with low-grade endometrial stromal sarcoma(LG-ESS), and 162 (10.9%) with adenosarcoma (AS). The OP group included 418 women(28.2%). Differences in the rate of OP were noted based on histology (p=0.014), year ofdiagnosis (p=0.001), patient age (p<0.001) and race (p=0.012). There was no difference in OS(p=0.220) or CSS (p=0.210) between women who had OP and those who did not. Multivariateanalysis confirmed that OP was not associated with a worse mortality. Conclusion: In this population-based cohort of women with sarcoma limited to the uterus,OP was not associated with worse oncologic outcomes. OP could be considered for womenwith LMS, sparing them from the morbidity associated with iatrogenic menopause. Noconclusions could be made for those with LG-ESS or AS.

Dipeptidyl Peptidase-4 Inhibitors and COVID-19-Related Deaths among Patients with Type 2 Diabetes Mellitus: A Meta-Analysis of Observational Studies

Dimitrios Patoulias,Michael Doumas 대한내분비학회 2021 Endocrinology and metabolism Vol.36 No.4

The coronavirus disease 2019 (COVID-19) pandemic remains an unbeaten enemy. Unfortunately, no targeted treatment option isavailable. Patients with type 2 diabetes mellitus (T2DM) have increased odds for severe or fatal disease, as demonstrated in recentobservational studies. There is an ongoing discussion regarding the impact of different antidiabetic drug classes on outcomes of interest among affected subjects. Dipeptidyl peptidase-4 (DPP-4) inhibitors have been placed at the epicenter, since the DPP-4 enzymeseems to be implicated in the disease pathogenesis. Herein we present an updated meta-analysis of observational studies addressingthe risk of COVID-19 death among patients with T2DM on prior DPP-4 inhibitor treatment. We pooled data from 10 observationalstudies, showing that DPP-4 inhibitors produce a non-significant decrease in the risk for COVID-19-related death. However, whenadministered in the inpatient setting, DPP-4 inhibitors decrease the risk for COVID-19-related death by 50%. Ongoing randomizedcontrolled trials will shed further light.

Residents' Perceptions of the Socio-Cultural Impacts of Tourism in Kavala

Dimitrios Stylidis,Edith Szivas,Avital Biran 세계문화관광학회 2011 Conference Proceedings Vol.12 No.-

This paper investigates how residents of a tourist destination (Kavala) perceive the socio-cultural impacts of tourism on their community and examines whether factors tested in the past like residents' socio-demographic characteristics (age education and distance they live from the tourism zone) level of attachment to the community and their economic dependence on the tourism industry influence these perceptions. Although many studies in the past have examined residents' perceptions of the economic impacts of tourism the socio-cultural impacts have been less frequently studied especially in the context of an urban environment which is in the initial stages of tourism development. This paper filled this gap in the literature by collecting data from the city of Kavala in Greece. In the current study survey was selected as the most appropriate method for the primary data collection and a self-completed questionnaire was distributed to 500 adult residents of Kavala who were selected after a multi-stage cluster sampling technique was applied. The findings of the study revealed differences in residents' perceptions of tourism impacts due to factors like respondents' economic reliance on tourism and their level of attachment to Kavala. These results have important implications for the planning and development of tourism both in Kavala as well as in other destination with similar characteristics.

Co-infection with Influenza: Do Not Forget Aspergillus in the Immunosuppressed Neutropenic Host

Dimitrios P. Kontoyiannis,정동식 대한결핵및호흡기학회 2014 Tuberculosis and Respiratory Diseases Vol.76 No.5

Monitoring the failure mechanisms of a reinforced concrete beam strengthened by textile reinforced cement using acoustic emission and digital image correlation

Dimitrios G. Aggelis,Svetlana Verbruggen,Eleni Tsangouri,Tine Tysmans,Danny Van Hemelrijck 국제구조공학회 2016 Smart Structures and Systems, An International Jou Vol.17 No.1

One of the most commonly used techniques to strengthen steel reinforced concrete structures is the application of externally bonded patches in the form of carbon fiber reinforced polymers (CFRP) or recently, textile reinforced cements (TRC). These external patches undertake the tensile stress of bending constraining concrete cracking. Development of full-field inspection methodologies for fracture monitoring are important since the reinforcing layers are not transparent, hindering visual observation of the material condition underneath. In the present study acoustic emission (AE) and digital image correlation (DIC) are applied during four-point bending tests of large beams to follow the damage accumulation. AE helps to determine the onset of fracture as well as the different damage mechanisms through the registered shifts in AE rate, location of active sources and change in waveform parameters. The effect of wave propagation distance, which in large components and in-situ can well mask the original information as emitted by the fracture incidents is also discussed. Simultaneously, crucial information is supplied by DIC concerning the moments of stress release of the patches due to debonding, benchmarking the trends monitored by AE. From the point of view of mechanics, conclusions on the reinforcing contribution of the different repair methodologies are also drawn.