90 research outputs found

    NEW TRENDS IN GIS AND BIM FOR FACILITY MANAGEMENT IN THE CZECH REPUBLIC

    Get PDF
    Most of the state bureaus and ministries in the Czech Republic are located in the capital city Prague. The buildings are situated mostly in historical part of the city, where are high demands on compliance with the cultural heritage laws. Currently, the buildings are in unsatisfactory building conditions, their maintenance is expensive and due to complicated legislation and political processes the buildings are in a state of “permanent repairs”. More than twenty years our company operates and co-develops GIS/BIM application for facility management of administrative buildings in the Czech Republic. The main topics of this contribution is to present our general experiences in GIS and BIM development which is based on our concrete cases dealt with Czech ministries, to present basic legislation requirements in Czech facility management and to evaluate current trends in the field of GIS and BIM for facility management in the Czech Republic in response to other official state registries

    USAGE OF PHOTOGRAMMETRIC PROCESSING OF THERMAL IMAGES FOR CIVIL ENGINEERS

    Get PDF
    In climate conditions of the Czech Republic is getting more important to carry out thermal inspection during documentation and inventory of buildings. Capturing and photogrammetric processing of thermal images requires special photogrammetric approaches especially because of low thermal image resolution. Part of this paper is focused on photogrammetric processing of thermal images using different methods with different 2D and 3D results which help civil engineers and architects better interpretation of thermal imaging. Those results are presented on chosen test objects. Photogrammetric results are also analysed in terms of geometric accuracy. The importance of integration of 2D and 3D results to GIS and BIM for facility management is discussed in final part of the paper

    Energetics and performance of a microscopic heat engine based on exact calculations of work and heat distributions

    Full text link
    We investigate a microscopic motor based on an externally controlled two-level system. One cycle of the motor operation consists of two strokes. Within each stroke, the two-level system is in contact with a given thermal bath and its energy levels are driven with a constant rate. The time evolution of the occupation probabilities of the two states are controlled by one rate equation and represent the system's response with respect to the external driving. We give the exact solution of the rate equation for the limit cycle and discuss the emerging thermodynamics: the work done on the environment, the heat exchanged with the baths, the entropy production, the motor's efficiency, and the power output. Furthermore we introduce an augmented stochastic process which reflects, at a given time, both the occupation probabilities for the two states and the time spent in the individual states during the previous evolution. The exact calculation of the evolution operator for the augmented process allows us to discuss in detail the probability density for the performed work during the limit cycle. In the strongly irreversible regime, the density exhibits important qualitative differences with respect to the more common Gaussian shape in the regime of weak irreversibility.Comment: 21 pages, 7 figure

    Increasing atmospheric temperature implicates increasing risk for acute type A dissection in hypertensive patients

    Full text link
    Background: Acute type A aortic dissection (AAAD) is a life-threatening condition with high mortality within 24 hours. We hypothesized if there is a correlation between seasonal weather changes and the occurrence of AAAD. The aim of the present study was to identify seasonal specific weather and patient characteristics predicting the occurrence of AAAD. Methods: This is a retrospective analysis of all consecutive patients of our department with AAAD between January 1st 2006 and December 31st 2016. The national meteorological department provided the data of temperature, humidity and air pressure during the study period. The occurrence of AAAD, preoperative neurological impairment and mortality were analyzed in correlation with the obtained daily weather data within the entire cohort and in patients with and without hypertension separately. Results: A total of 517 patients were included. Mean age was 63.4±13 years, 69.4% were male and 68.8% had documented hypertension. In-hospital mortality was 17.7%. In the whole cohort, the occurrence of AAAD was significantly increased in March, October, December (P=0.016). In hypertensive patients, the occurrence was increased 34% with rising temperature (0.1-9.6 °C, OR1.34, 95% CI: 1.06-1.69, P=0.015). There was no correlation between weather variables and preoperative neurological impairment or mortality. Conclusions: Our data suggests a relation between an increasing number of events of AAAD and certain months within our catchment area and a significantly increased occurrence with rising temperatures (independent from absolute temperature at time of the event) in hypertensive patients

    A minimal model of an autonomous thermal motor

    Full text link
    We consider a model of a Brownian motor composed of two coupled overdamped degrees of freedom moving in periodic potentials and driven by two heat reservoirs. This model exhibits a spontaneous breaking of symmetry and gives rise to directed transport in the case of a non- vanishing interparticle interaction strength. For strong coupling between the particles we derive an expression for the propagation velocity valid for arbitrary periodic potentials. In the limit of strong coupling the model is equivalent to the B\"uttiker-Landauer model [1-3] for a single particle diffusing in an environment with position dependent temperature. By using numerical calculations of the Fokker-Planck equation and simulations of the Langevin equations we study the model for arbitrary coupling, retrieving many features of the strong coupling limit. In particular, directed transport emerges even for symmetric potentials. For distinct heat reservoirs the heat currents are well-defined quantities allowing a study of the motor efficiency. We show that the optimal working regime occurs for moderate coupling. Finally, we introduce a model with discrete phase space which captures the essential features of the continuous model, can be solved in the limit of weak coupling, and exhibits a larger efficiency than the continuous counterpart.Comment: Revised version. Extended discussion on the discrete model. To appear in EP

    Twenty-five year experience with aortic valve-sparing root replacement in a single teaching center

    Get PDF
    OBJECTIVES Aortic valve-sparing root replacement (AVSRR) is a technically demanding procedure. In experienced centers it offers excellent short- and long-term results, making the procedure an attractive alternative for aortic root replacement especially in young patients. The aim of this study was to analyze long-term results of AVSRR using the David operation in our institution over the last 25 years. METHODS This is a single-center retrospective analysis of outcomes of David operations performed in a teaching institution not running a large AVSRR-program. Pre-, intra- and postoperative data were collected from the institutional electronic medical record system. Follow-up data were collected through direct contact of the patients and their cardiologists/primary care physicians. RESULTS Between 02/1996 and 11/2019, 131 patients underwent David operation in our institution by a total of 17 different surgeons. Median age was 48 (33-59), 18% were female. Elective surgery was performed in 89% of the cases, 11% were operated as emergency in the setting of an acute aortic dissection. Connective tissue disease was present in 24% and 26% had a bicuspid aortic valve. At hospital admission 61% had aortic regurgitation grade ≥3, 12% were in functional NYHA-class ≥III. 30-day mortality was 2%, 97% of the patients were discharged with aortic regurgitation ≤2. In 10-year follow-up, 15 (12%) patients had to be re-operated because of root-related complications. Seven patients (47%) received a transcatheter aortic valve implantation, 8 (53%) required surgical replacement of the aortic valve or a Bentall-De Bono operation. Estimated reoperation-free survival at 5 and 10 years was 93.5% ± 2.4% and 87.0% ± 3.5%, respectively. Subgroup analysis showed no differences in reoperation-free survival for patients presenting with a bicuspid valve or preoperative aortic regurgitation ≥3. However a preoperative left ventricular end diastolic diameter of ≥5.5 cm was associated with worse outcome. CONCLUSION David operations can be performed with excellent perioperative and 10-year follow-up outcomes in centers not running large AVSRR-programs

    Welwitindolinone C synthetic studies. Construction of the welwitindolinone carbon skeleton via a transannular nitrone cycloaddition

    Get PDF
    Described is the construction of the N-methylwelwitindolinone C core via an efficient strategy that employs a sequential rhodium carbenoid-mediated O–H insertion, Claisen rearrangement and transannular [3+2] nitrone cycloaddition

    Analysis of landrace cultivation in Europe: A means to support in situ conservation of crop diversity

    Get PDF
    During the last century, the progressive substitution of landraces with modern, high yielding varieties, led to a dramatic reduction of in situ conserved crop diversity in Europe. Nowadays there is limited and scattered information on where landraces are cultivated. To fill this gap and lay the groundwork for a regional landrace in situ conservation strategy, information on more than 19,335 geo-referenced landrace cultivation sites were collated from 14 European countries. According to collected data, landraces of 141 herbaceous and 48 tree species are cultivated across Europe: Italy (107 species), Greece (93), Portugal (45) and Spain (44) hold the highest numbers. Common bean, onion, tomato, potato and apple are the species of main interest in the covered countries. As from collected data, about 19.8% of landrace cultivation sites are in protected areas of the Natura 2000 network. We also got evidence that 16.7% and 19.3% of conservation varieties of agricultural species and vegetables are currently cultivated, respectively. Results of the GIS analysis allowed the identification of 1261 cells (25 km Ă— 25 km) including all the cultivation sites, distributed across all European biogeographical regions. Data of this study constitute the largest ever produced database of in situ-maintained landraces and the first attempt to create an inventory for the entire Europe. The availability of such resource will serve for better planning of actions and development of policies to protect landraces and foster their use

    Conformal mappings versus other power series methods for solving ordinary differential equations: illustration on anharmonic oscillators

    Full text link
    The simplicity and the efficiency of a quasi-analytical method for solving nonlinear ordinary differential equations (ODE), is illustrated on the study of anharmonic oscillators (AO) with a potential V(x)=βx2+x2mV(x) =\beta x^{2}+x^{2m} (m>0m>0). The method [Nucl. Phys. B801, 296 (2008)], applies a priori to any ODE with two-point boundaries (one being located at infinity), the solution of which has singularities in the complex plane of the independent variable xx. A conformal mapping of a suitably chosen angular sector of the complex plane of xx upon the unit disc centered at the origin makes convergent the transformed Taylor series of the generic solution so that the boundary condition at infinity can be easily imposed. In principle, this constraint, when applied on the logarithmic-derivative of the wave function, determines the eigenvalues to an arbitrary level of accuracy. In practice, for β≥0\beta \geq 0 or slightly negative, the accuracy of the results obtained is astonishingly large with regards to the modest computing power used. It is explained why the efficiency of the method decreases as β\beta is more and more negative. Various aspects of the method and comparisons with some seemingly similar methods, based also on expressing the solution as a Taylor series, are shortly reviewed, presented and discussed.Comment: 32 pages, 7 figures, 8 table
    • …
    corecore