Flame balls in mixing layers

We present a study of flame balls in a two-dimensional mixing layer with one objective being to derive an ignition criterion (for triple-flames) in such a non-homogeneous reactive mixture. The problem is formulated within a thermo-diffusive single-reaction model and leads for large values of the Zeldovich number β$\beta$ to a free boundary problem. The free boundary problem is then solved analytically in the asymptotic limit of large values of the Damköhler number, which represents a non-dimensional measure of the (square of the) mixing layer thickness. The explicit solution, which describes a non-spherical flame ball generalising the classical Zeldovich flame balls (ZFB) to a non-uniform mixture, is shown to exist only if centred at a single location. This location is found to be precisely that of the leading-edge of a triple-flame in the mixing layer, and typically differs from the location of the stoichiometric surface by an amount of order β^-1${\beta }^{-1}$ depending only on a normalised stoichiometric coefficient Δ$\Delta$.     

Influence of traditional brine washing of smear Taleggio cheese on the surface spreading of Listeria innocua

The influence of a traditional procedure of washing of smear Taleggio cheese on surface spreading of Listeria innocua was studied. This practice is carried out during ripening to remove molds, to select the surface microflora, and to control the ripening process. One cheese, both of 2 (i) and 4 (ii) weeks of ripening, was surface-inoculated with approximately 3 log CFU of L. innocua per entire cheese surface. The inoculated cheeses and others of the same age were weekly washed with brine solution. Listeria was spread both on the surface of the inoculated cheese and on the other cheeses, and it was also found in the brines and on the wooden boxes where the cheeses were ripened. The time of ripening when contamination occurs influenced the behavior of Listeria. At the moment of contamination, the smear surface microflora of (i) cheese was approximately 2 log CFU/g higher than of (ii) cheese. Listeria inoculated on 2-week-ripened cheese was able to colonize the entire surface of the cheese and to cross-contaminate the other cheeses. On the contrary, Listeria inoculated on a 4-week-ripened cheese was partially spread on the surface of the originally inoculated cheese, and the transfer of contamination by the washing procedure was restrained. Because a random distribution of Listeria on cheese surface was observed, the importance of the mode of sampling was discussed. Because of the lack of critical control points during ripening of Taleggio cheese, the Listeria hazard needs to be controlled by taking appropriate control measures to break off the contamination cycle (cheese --> brine --> wooden boxes --> cheese).     

Photon diffusion coefficient in scattering and absorbing media

We present a unified derivation of the photon diffusion coefficient for both steady-state and time-dependent transport in disordered absorbing media. The derivation is based on a modal analysis of the time-dependent radiative transfer equation. This approach confirms that the dynamic diffusion coefficient is given by the random-walk result D = cl(*)/3, where l(*) is the transport mean free path and c is the energy velocity, independent of the level of absorption. It also shows that the diffusion coefficient for steady-state transport, often used in biomedical optics, depends on absorption, in agreement with recent theoretical and experimental works. These two results resolve a recurrent controversy in light propagation and imaging in scattering media.     

Employing electricity-consumption monitoring systems and integrative time-series analysis models: A case study in Bogor,Indonesia

The Paris Agreement calls for maintaining a global temperature less than 2°C above the pre-industrial level and pursuing efforts to limit the temperature increase even further to 1.5°C. To realize this objective and promote a low-carbon society, and because energy production and use is the largest source of global greenhouse-gas (GHG) emissions, it is important to efficiently manage energy demand and supply systems. This, in turn, requires theoretical and practical research and innovation in smart energy monitoring technologies, the identification of appropriate methods for detailed time-series analysis, and the application of these technologies at urban and national scales. Further, because developing countries contribute increasing shares of domestic energy consumption, it is important to consider the application of such innovations in these areas. Motivated by the mandates set out in global agreements on climate change and low-carbon societies, this paper focuses on the development of a smart energy monitoring system (SEMS) and its deployment in households and public and commercial sectors in Bogor, Indonesia. An electricity demand prediction model is developed for each device using the Auto-Regression eXogenous model. The real-time SEMS data and time-series clustering to explore similarities in electricity consumption patterns between monitored units, such as residential, public, and commercial buildings, in Bogor is, then, used. These clusters are evaluated using peak demand and Ramadan term characteristics. The resulting energy-prediction models can be used for low-carbon planning.     

Expert networks as science-policy interlocutors in the implementation of a monitoring reporting and verification (MRV) system

The Paris Agreement, which entered into effect in 2016, emphasizes a definite timeline for communicating and maintaining successive nationally determined contributions (NDCs) that it plans to achieve in addressing climate change. This calls for the development of a measurement, reporting and verification (MRV) system and a Capacity-building Initiative for Transparency (CBIT). Though such actions are universally accepted by the Parties to the Paris Agreement, earlier studies have shown that there remain technological, social, political and financial constrains which will affect the development and deployment of such a system. In this paper, using a case study on MRV implementation in Bogor City in Indonesia, how the above-mentioned challenges can be overcome is outlined through a technological and policy innovation process where scientists and technologists (collectively referred as expert networks) can join hands with local governments and national policy makers in designing, development and implementation of an MRV system that meets the local, national and global requirements. Through the case study it is further observed that expert networks can act as interactive knowledge generators and policy interlocutors in bridging technology with policy. To be specific, first, a brief history of the international context of MRV and CBIT is outlined. Next, the theoretical underpinning of the study is contextualized within the existing theories related to public policy and international relations. Finally, the case study is outlined and investigated where the engagement of an expert-network and policy makers in the design, development and implementation of an MRV tool is showcased.     

Molecular profiling of native and matrix-coated tissue slices from rat brain by infrared and ultraviolet laser desorption/ionization orthogonal time-of-flight mass spectrometry

Phospho- and glycolipids contained in the plasma membrane of neuronal tissue were profiled by direct infrared laser desorption/ionization orthogonal time-of-flight mass spectrometry (IR-LDI-o-TOF-MS), performed on cryosected native slices generated from rat brain. About 100 different detected lipid species are putatively assigned based on their molecular weight. Spraying of potassium acetate onto the slices was found to facilitate data interpretation in positive ion mode by reducing residual sodium adduct ion intensities. Coating the slices with matrix and using an ultraviolet laser for UV-MALDI-o-TOF-MS extends the analysis to peptides and small proteins but induces analyte diffusion. Peptides and partially cleaved proteins derived from proteolytic digests were recorded after incubation of native sections with trypsin and subsequent coating of the slices with MALDI matrix.     

Selection of Lactobacillus plantarum strains to use as starters in fermented table olives: Oleuropeinase activity and phage sensitivity

Fermented table olives (Olea europaea L.) are largely diffused in the Mediterranean area. Olives are picked at different stages of maturity and after harvesting, processed to eliminate the characteristic bitterness caused by the presence of the oleuropein glucoside and to become suitable for human consumption. The spontaneous fermentation of table olives mainly depends on lactic acid bacteria (LAB), and in particular on Lactobacillus plantarum which plays an important role in the degradation of oleuropein. The hydrolysis of oleuropein is attributed to the β-glucosidase and esterase activities of the indigenous LAB microflora. This study investigated the potential of L. plantarum strains isolated from dairy products and olives to be used as starters for fermented table olives. Forty-nine strains were typed by RAPD-PCR and investigated for the presence of the β-glucosidase (bglH) gene. The full sequence of the bglH gene was carried out. All the 49 L. plantarum strains were also tested for phage resistance. A total of six strains were selected on the basis of genotypic polymorphism, bglH gene sequence analysis, and phage resistance profile. These strains were further characterized to assess the acidifying capability, the growth at different temperatures, the tolerance to different NaCl concentrations, and the oleuropeinolytic activity. Although further characterizations are required, especially concerning the influence on sensory properties, L. plantarum proved to have the potential to be used as a debittering and fermentative agent in starter culture for fermented table olives.