On Realization of Cinema Hall Fire Simulation Using Fire Dynamics Simulator

Currently known fire models are capable to describe fire dynamics in complex environments incorporating a wide variety of fire-related physical and chemical phenomena and utilizing large computational power of contemporary computers. In this paper, some issues related to realization of the simulation of fire in a cinema hall with sloping floor and curved ceiling furnished by upholstered seats modelled by FDS (Fire Dynamics Simulator) are discussed. The paper concentrates particularly on the impact of a computational meshes choice on resolving flow field and turbulence in the simulation and indicates problems related to parallelization of the calculation illustrated comparing sequential and parallel MPI calculation using 6 CPU cores. Results of the simulation described and their discussion demonstrate the ability of FDS simulation to capture main tendencies of smoke spread and to forecast the related safety risks realistically

A Note on Mathematical Modelling of Elliptical Fire Propagation

Mathematical modelling of forest fire propagation in time plays a key role in existing fire propagation predicting systems. Such systems are capable of simulating the growth of fire front in time and space and predicting spatial and temporal fire behaviour. In our previous papers, we studied mathematical foundations of the elliptical fire propagation model implemented in several advanced simulation systems.The model is based on Huygens' principle applied on fire propagation assuming locally elliptical fire spread. However, in the literature various other mathematical representations of local fire propagation have been reported, such as double ellipse, lemniskata, oval shape, tear shape, and others. Such types of local fire propagation have been experimentally observed in certain conditions during laboratory and field fires. In this paper, we demonstrate several simple examples of fire propagation corresponding both to the elliptical and non-elliptical local fire propagation in homogeneous conditions

Parallel Computation of Smoke Movement During a Car Park Fire

In this paper the use of Fire Dynamics Simulator (FDS) for parallel computer simulation of the smoke movement during a fire of two passenger cars in an underground car park is investigated. The simulations were executed on a high-performance computer cluster. A specific problem of FDS parallel computation using Message-Passing Interface (MPI) is a separate solution of governing equations on computational subdomains causing a loss of accuracy. Therefore, the impact of parallelisation on simulation accuracy in the case of using a greater number of computational cores of the computer cluster is studied with the aim to increase the computational performance and enable practical application of such simulations for fire safety measures. The geometrical model and material properties of the cars used in the simulation have been verified by a full-scale fire experiment in open air. We describe the results of a series of simulations of several fire scenarios with different numbers of parked cars and ventilation configurations and determine times and locations at which conditions in the car park become untenable for human life. The simulation indicates that proper ventilation prolongs tenable conditions by several minutes

Computing Aspects of Simulation Based on Conservation Laws Conducted on HPC Cluster

The large amount of computing resources required for the simulation of complex natural processes demands a thorough analysis of the efficiency of the calculations and the conditions that influence it. This study investigates computing aspects of fire simulation conducted on a compute cluster. Current fire simulators based on principles of computational fluid dynamics are capable to realistically model majority of complex phenomena related to fire. Fire simulations are highly computationally demanding itself, however, they often lead to extensive parametrical studies requiring high performance computing systems. Smoke stratification and visibility during fire in a road tunnel with two emergency lay-bys are investigated by parametrical study comprising of 24 fire scenarios with the tunnel geometry modifications and various heat release rates and fire locations. Main tendencies of smoke spread in the downstream lay-by are identified and their mutual interactions are analysed. The simulation efficiency of particular simulations is analysed and the reasons of their varied elapsed times are investigated. The analysis indicates that the main reason of this variability are different jet fans velocities influenced by simulation scenario settings

Detection and characterisation of Plum pox virus (PPV) isolates from Eastern Slovakia revealed the presence of three main viral strains.

Plum pox virus (PPV), the agent responsible for Sharka disease, is the most important viral pathogen of stone fruit trees world-wide, having an endemic status in Slovakia. To increase knowledge of PPV diversity in Slovakia, a set of 11 isolates, originated from the eastern part of the country, was characterised. The isolates were chip-budded from their original Prunus hosts to the susceptible GF305 indicators, exhibiting the symptoms of variable severity. A genomic region encompassing the partial NIb and the hypervariable 5´terminal region of the CP gene was amplified from all 11 isolates in RT-PCR and directly sequenced. The phylogenetic analysis revealed the grouping of the 11 Slovak isolates into 3 distinct clusters, representing the PPV-M (2 isolates), D (7 isolates) and Rec strains (2 isolates). The strain affiliation of isolates was further confirmed by strain-specific RT-PCR, using which the presence of additional mixed infection by minor PPV variants was detected in 2 samples. The results further contribute to the understanding of PPV diversity in Slovakia and confirm the specificity and sensitivity of molecular approaches used for the virus strain determination

Biolistic transfection of plants by infectious cDNA clones of Plum pox virus

Plant biolistic transfection by two Plum pox virus (PPV) infectious cDNA clones (strains PPV-M and PPV-D) using the gene gun apparatus PDS 1000-He was optimized. Nicotiana benthamiana plants were germinated on Petri dishes with MS growth medium. At the age of four weeks the plants were subjected to biolistic transfection and three days later were transplanted into common soil substrate. The plant survival after transplantation was about 70 %, the transfection efficiency was over 80 % (compared to 6 – 10 % efficiency reached by mechanical plant inoculation). The plants showed typical PPV symptoms two weeks post transfection. The virus presence was confirmed by immunoblotting, RTPCR, as well as by successful transmission by sap to healthy plants. The co-transfection of N. benthamiana plants by PPV-M and PPV-D led to mixed infections with PPV-D strongly prevalent. We assumed the properties of cDNA constructs responsible for this behaviour.Keywords: gene gun, PPV strains, immunoblottin

Regulation of healthcare ethics committees in Europe

In this article, the question is discussed if and how Healthcare Ethics Committees (HECs) should be regulated. The paper consists of two parts. First, authors from eight EC member countries describe the status quo in their respective countries, and give reasons as to the form of regulation they consider most adequate. In the second part, the country reports are analysed. It is suggested that regulation of HECs should be central and weak. Central regulation is argued to be apt to improve HECs’ accountability, relevance and comparability. To facilitate biomedical citizenship and ethical reflection, regulation should at the same time be weak rather than strict. Independence of HECs to deliberate about ethical questions, and to give solicited and unsolicited advice, should be supported and only interfered with by way of exception. One exception is when circumstances become temporary adversarial to ethical deliberation in healthcare institutions. In view of European unification, steps should be taken to develop consistent policies for both Eastern and Western European countries

The impact of car park fire on concrete structure, Parallel computation

This study examines the influence of automobile fire in a car park on concrete parts of the structure. In 2009, a series of full-scale fire experiments in open air was conducted, including the fire in automobile interior and its influence onto a vehicle in its vicinity. We performed a set of simulations of this scenario, using the NIST FDS system, version 5.5.3. Comparison with experimental data confirmed the simulation reliability. In this paper, we use material properties of car interior materials established by our research to simulate a car fire in a small part of car park containing two burning cars and its influence on concrete ceiling and a pillar in the vicinity of the cars. We use here the calculation with 48 and more MPI processes to evaluate the ability of high performance computing to solve problems of structural fire safety