109 research outputs found
A Review of Socio-Economic Consequences, Losses and Human Casualties of the 1977 Vrancea, Romania Earthquake
Although its socio-economic disaster pattern was obvious, the March 4, 1977 Vrancea, Romania earthquake was studied mainly in seismological and earthquake engineering terms. In 1977, the loss data released in Romania, referred to 32,900 collapsed or heavily damaged dwellings, 35,000 homeless families, thousands of damaged buildings, many other damages and destructions in industry and economy, 1,578 people killed, 11,321 people injured (with 90% of the killed and 67% of the injured being in the city of Bucharest). The Romanian government reported the economic losses from this event in December 1977, as being US$ 2 billion. For a long time, the evaluation of human casualties vs. collapse pattern of buildings in 1977 was not addressed and we still miss integral data. The recovery and reevaluation of economic and social impacts of the 1977 disaster was a concern of the authors, with the intent to better understand its consequences and prepare a new strategy of seismic risk reduction in view of future earthquakes in Romania, and in order to fill that gap the authors recovered many unpublished and obscure data
Teorija rezonancija i primjena na reakcije elektronskog prijenosa u fotosintetičkim reakcijskim središtima
A detailed theoretical description of the "resonance treatment" based on Bloch equations is presented for a dissipative two-state system, in the limit of weak coupling between a microscopic subsystem and its environment, using the framework of the "spin-boson" model. For an Ohmic spectral density function, the dynamics of the transition probability for an overdamped regime is applied in the case of the primary electron transfer reaction in a bacterial photosynthetic reaction center.Opisuje se podrobno teorija “rezonantnog postupka” zasnovana na Blochovim jednadžbama za disipativan sustav s dva stanja, u granici slabog vezanja mikroskopskog sustava s njegovom okolinom, u okviru “spin-bozon” modela. Uz pretpostavku omske spektralne funkcije gustoće, primjenjuje se dinamika prijelazne vjerojatnosti u natkritično- gušenim uvjetima u slučaju prvotne reakcije elektronskog prijenosa u bakterijskom fotosintetičkom reakcijskom središtu
Enhancement of seismic resistance of buildings
The objectives of the paper are both seismic instrumentation for damage assessment and enhancing of seismic resistance of buildings. In according with seismic design codes in force the buildings are designed to resist at seismic actions. Due to the time evolution of these design provisions, there are buildings that were designed decades ago, under the less stringent provisions. The conceptual conformation is nowadays provided in all Codes of seismic design. According to the Code of seismic design P100-1:2006 the asymmetric structures do not have an appropriate seismic configuration; they have disadvantageous distribution of volumes, mass and stiffness. Using results of temporary seismic instrumentation the safety condition of the building may be assessed in different phases of work. Based on this method, the strengthening solutions may be identified and the need of seismic joints may be emphasised. All the aforementioned ideas are illustrated through a case study. Therefore it will be analysed the dynamic parameter evolution of an educational building obtained in different periods. Also, structural intervention scenarios to enhance seismic resistance will be presented
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