Comprehensive investigation of intact, vulnerable stalagmites to estimate an upper limit on prehistoric ground acceleration

Non-intrusive in situ measurements were carried out in caves in Hungary, Bulgaria and Slovakia in order to determine the fundamental frequencies (FF) and horizontal ground accelerations (HGA) resulting in failure of intact, slim, vulnerable stalagmites. Similar investigations are planned in Austria at the Eastern Alps. The main steps of investigation are: 1) FF of intact stalagmites were determined by in situ observation. 2) Density, Young’s modulus and tensile fa ilure stress of broken stalagmites ha ve been measured in mechanical laboratory. 3) The value of HGA resulting in failure and FF of stalagmite were assessed by theoretical calculations. 4) Age determination of co re-samples. The upper limit for HGA, a g , for slim stalagmites determined by theoretical calculations, can arise even for moderate-sized eart hquakes. The FF of the investigated stalagmites are low. The geological stru ctures close to the investigated caves did not excite paleoearthquakes in the determined time period, corresponding to HGA larger than the determined a g values

Preparation and Application of Copper Clad Laminate with Microwave Ceramic and resin for Microwave PCB

有机树脂的特殊结构使它兼具无机和有机化合物的特点，是一种具有优异综合性能的树脂。其具有较低的介电常数和较低的介质损耗因子，同时具有高的耐热性和低的吸水性，并且在宽广的温度和高频范围内介电性能稳定，可用作介电性能好、高频特性好、耐高温的印制电路板（PCB）基体树脂。为了实现更低介电常数和更低介质损耗因子的高速信息传输或者实现更高介电常数和低介质损耗因子的小体积微波电路，需要进行改性研究获得优良复合PCB材料。 首先，针对有机树脂力学强度较差的问题，本论文从成型温度和压力等热压工艺条件入手，探究了玻璃纤维增强树脂介质复合板的制备工艺并探讨了其介电和力学等性能。 其次，为了进一步降低有机树脂的介...reEn has both its inorganic and organic structural characteristics, so that it possesses excellent performance. reEn matrix compoEtes are ususally selected as high-frequency microwave circuit boards materials uEng in printed circuit board (PCB) for its low dielectric constant and low dielectric loss. New type of microwave PCB was developed in this paper, in order to achieve lower dielectric consta...学位：工学硕士院系专业：材料学院_材料学学号：2072010115010

Strong Intermediate-Depth Vrancea Earthquakes: Damage Capacity

Abstract The sustainable development of the society depends not only on a reasonable policy for economical growth but also on the reasonable management of natural risks. The regional earthquake danger due to the Vrancea intermediate-depth earthquakes dominates the hazard of NE Bulgaria. These quakes have particularly long-period and far-reaching effects, causing damages at large epicentral distances. Vrancea events energy attenuates considerably less rapidly than that of the wave field radiated by the seismically active zones in Bulgaria. The available strong motion records at Russe, NE Bulgaria, due to both Vrancea events - August 30, 1986 and May 30, 1990 show higher seismic response spectra amplitudes for periods up to 0.6 s for the horizontal components, compared to the values given in the Bulgarian Code and Eurocode 8. A neo-deterministic analytical procedure which models the wavefield generated by a realistic earthquake source, as it propagates through a laterally varying anelastic medium, is applied to obtain the seismic loading at Russe. After proper validation, using the few available data and parametric analyses, from the synthesized seismic signals damage capacity of selected scenario Vrancea quakes is estimated and compared with available capacity curves for some reinforced concrete and masonry structures, representative of the Balkan Region. The performed modelling has shown that the earthquake focal mechanisms control the seismic loading much more than the local geology, and that the site response should be analyzed by considering the whole thickness of sediments until the bedrock, and not only the topmost 30 m. 2 THE VRANCEA EARTHQUAKE HAZARD The Vrancea subduction seismogenic zone is a peculiar intermediate-depth source that, in case of large magnitude earthquake, strongly affects a significant part of the Bulgarian territory including major cities in NE Bulgaria, among which the biggest Bulgarian port on the Danube -the town of Russe. The impact of a major Vrancea intermediate-depth earthquake may produce strong direct damage, as well as indirect losses in other regions of the country, thus leading to a national disaster. when no seismic regulation were available). This fact, the lack of enough instrumental strong motion records and the peculiarity of the intermediate-depth Vrancea seismic source call our attention to the necessity of providing, by modelling, reliable seismic input that might be used for the purpose of retrofitting and urban planning. THE NEO-DETERMINISTIC GROUND MOTION MODELLING PROCEDURE: APPLICATION FOR THE CASE-STUDY OF RUSSE, NE BULGARIA A neo-deterministic analytical procedure has been applied to obtain the seismic input at Russe . The major advantage of the applied neo-deterministic procedure is the simultaneous treatment of the contribution of the seismic source and of the seismic wave propagation media to the strong motion at the target site/region, as required by basic physical principles. Generally, the computation model, describing the seismic wave propagation path from the seismic source to the target site consists of two structural models, bedrock, representing the travel path from the source to the site, and local model, representing the local engineering geological features of the site of interest. To model the seismic input at Russe the analytical neodeterministic approach based on mode coupling technique, is used Input data Seismic wave propagation path The structural model used in the computations consists of two horizontally layered half spaces in welded contact. The bedrock structure contains the source and the path from the Vrancea seismic sources to the target sites. The profile Vrancea-Russe passes through the Carpathians and the Moesian Platform, where Pliocene and significant Quaternary deposits are present. Details on the computation model and on the geological information used are published by Paskaleva et al. [2001]. In this study the target site of Russe is represented by three generalized local geological models corresponding to the soil classes A, B and C according to the Eurocode 8 (EC8) ground type classification. A summary of the local geological velocity models, constructed following the EC8 soil classification and used in this study, is given in Scenario earthquakes In accordance with the international experience, a reasonable choice of scenario earthquakes should take into account both historical earthquakes record and seismic hazard analysis. Simulation tests and results verification Following the models defined i

Pre-graduate internship of students from specialty `rehabilitation` - innovation and motivation for conducting

Practical training of students from Specialty `Rehabilitation` is performed in two directions: Practical activi- ties of students in specialized offices under the guidance of a teacher; Clinical practice and pre-graduate sum- mer internships in academic and practical bases under the supervision of a teacher and the active participation of a mentor. Pre-graduate internship of students from Medical College - Stara Zagora is in the sixth semester and it has an academic workload of 800 hours. It is held in certain clinics according to a curric- ulum and it is conducted at school - practical bases. In order to improve the criteria for evaluation and moni- toring of trainees a trainee record was introduced for a daily reporting of the activity and the work with different patients under a guidance of mentors