Amplitude Variability in Simulated Incoherent Seismic Ground Motions

This note compares in detail four commonly used schemes for the simulation of spatially variable ground motions. Emphasis is placed not only on the conformity of the simulations with the power and cross spectral density of the random field but, also, on the examination of the consistency of the simulations with the homogeneity condition, and the (Fourier) amplitude variability of the simulations. It is shown that, whereas three techniques that simulate ground motions in parallel satisfy the homogeneity requirement, produce simulations with random amplitudes, and amplitude and phase variability consistent with that of recorded data, one technique that simulates motions in sequence does not.     

Enumeration of bifidobacteria in dairy products

There is much interest in the potential role of bifidobacteria as dietary inclusions, but their isolation from dairy products, and subsequent identification, can cause problems. A range of selective and non-selective media were examined, and modified Rogosa agar was found to give the best recovery from yogurt-like products. A morphological examination of typical isolates suggested that only bifidobacteria had grown on the medium, but confirmation by means of biochemical tests proved inconclusive, and it seems that the genus/species definition merits further attention.     

Seismic loads predicted by spatial variability models

Seismic loads that result from different expressions describing the spatial variability of the seismic ground motions at the supports of lifelines are evaluated and compared in this study. The analysis considers two spatial variability models, that are commonly used in lifeline earthquake engineering, namely the ones developed by Harichandran and Vanmarcke (J. Eng. Mech., 112 (1986)) and by Luco and Wong (Earthquake Eng. Struct. Dyn., 14 (1986)). It is shown that the models produce significantly different seismic loads for the analysis of buried and above-ground lifelines.     

Seismic source mechanisms and ground motion models

A summary of the recently developed analytical models for the prediction of strong ground motions is presented in this paper. The models are classified into two groups: The first describes root mean square, peak values and Fourier spectra of ground accelerations and velocities, whereas the second develops power spectral densities, cross correlation coefficients and spatial variations of ground motions. Several source models used in the inverse problem, namely the problem of inferring source mechanisms from recorded data, are also discussed.     

Challenges in the Processing Line of Spanish Style cv. Chalkidiki Green Table Olives Spontaneously Fermented in Reduced NaCl Content Brines

In this work, the effect of different treatments using selected combinations of chloride salts (NaCl, KCl, CaCl_2, MgCl₂) in fermentation brine to assess the safety, quality, and nutritional value of the Spanish style cv. Chalkidiki green table olives spontaneously fermented is studied. Examination of safety parameters (bacteria/yeasts, pH, acidity) and changes in olive color and texture characteristics in brines during fermentation, and in mineral content of olives upon storage up to 12 months, is conducted using appropriate methods. Sensory evaluation takes place in certain cases. Among the tested salt combinations, those of 4.08% NaCl, 2.8% KCl, 1% CaCl₂, and 0.12% MgCl₂ (w/v) are found to be the most effective regarding safety, color, texture, and taste. Findings support that Spanish style cv. Chalkidiki green olives can be spontaneously fermented in reduced NaCl content brine. The 50% lower NaCl content of the fermented olives compared with that in traditionally fermented ones suggests that reformulation of cv. Chalkidiki green table olives by safe intervention is feasible. Practical Applications: cv. Chalkidiki green table olives are of high importance for the Greek economy. Traditionally they are spontaneously fermented in NaCl brine (8% w/v). Partial replacement of NaCl content with other salts in such a line results in a product acceptable in terms of safety and quality characteristics. The Greek table olive industry may profit from the findings in an attempt to remodel the traditional spontaneous fermentation in green olive processing according to international dietary guidelines.     

Bacterial species associated with sound and Botrytis-infected grapes from a Greek vineyard

Grape bacterial microbiota plays central roles in the quality of grapes and wine, yet its diversity remains poorly described. In the present study, bacterial species associated with sound and Botrytis-infected grapes of two cultivars originating from the same vineyard were assessed. Isolates were identified by PCR-Denaturing Gradient Gel Electrophoresis (PCR-DGGE) and sequence analysis of partial 16S rRNA gene. Comparable counts were recorded between Botrytis-infected and sound grape samples. In all cases, the majority of isolates belonged to different species of Enterobacteriaceae. The dominant species in the vineyard was Klebsiella oxytoca that was found in different combinations with Citrobacter freundii, Enterobacter spp., Erwinia sp., Pantoea dispersa, Tatumella ptyseos or other species. In fermenting musts, those populations declined while other species evolved, like Lactobacillus plantarum and Enterobacter ludwigii. Populations in botrytised samples persisted longer during spontaneous fermentations. Present study suggests that bacterial diversity on grapes may be wider than previously described.     

Approximate representation of the statistics for extreme responses of single degree-of-freedom system excited by non-stationary processes

The objective of this study is to estimate the statistics of the maximum response of a structural system excited by a non-stationary process. To provide basic information for the design of structures, the response of a single degree-of-freedom (SDOF) system subjected to a non-stationary Gaussian white noise is considered. For this purpose, we first derive the probabilistic properties of the maximum values of a non-stationary and zero-mean white noise, whose standard deviation varies temporally under some limited conditions. Then, using the obtained properties, we propose a method to estimate the stochastic properties of the maximum response of a given SDOF system excited by a non-stationary white noise whose time-varying standard deviation is known. The validity of the obtained results is confirmed through Monte Carlo simulation.     

Novel Phospholium-Type Cationic Surfactants: Synthesis,Aggregation Properties and Antimicrobial Activity

A series of novel phospholium amphiphilic compounds with straight alkyl chains with different numbers of carbon atoms (12, 14, 15, 16, 17, 18) were synthesized. The quaternary phosphorus, phosphonium cation, is incorporated into a five-membered heterocyclic ring. Their physicochemical properties were investigated by measurements of surface tension, conductivity and dynamic light scattering. The critical micelle concentration (c _M), the surface tension value at the c _M (γ _cmc), the surface area at the surface saturation per head group (A _cmc), the ionization degree of micelle (α), the free energy of micellization (ΔG° _mic), and hydrodynamic diameter (d _h) were determined. Antimicrobial activity was tested against bacteria and yeast. The structure–activity relationship was determined.