Marcos, martial law and memory: The past in our future in the Philippines: Adrian E. Cristobal Lecture

I was a martial law baby. My generation grew up watching the unending spectacle of Ferdinand and Imelda Marcos. Remember this was the 20th Century, long before YouTube and Netflix. I would have preferred to watch  Zombie Apocalypse but that wasn’t an option. There were only five TV channels and three newspapers, all owned by Marcos cronies.  We didn’t call it 'fake news' then but it was vintage 1970s propaganda—obvious and crude. I was in first grade when Marcos was first elected president. I studied across the street from Malacañang, in a school for girls run by the Sisters of the Holy Ghost. I remember that in the 1960s,  the streets around the presidential mansion were busy, filled with traffic and commerce. On Thursdays, hundreds  flocked to the church nearby to pray to St. Jude, patron of hopeless causes. I was barely in my teens when martial law was declared. Suddenly the streets were silenced. The palace gates were shuttered. Barbed wire barricades kept people away. The neighborhood—the entire country—was hushed. Marcos was still president when I finished high school. He continued to issue decrees from his barricaded palace while I went off to college, graduated, and got my first job. My generation had reached adulthood with no memory of any other president.&nbsp

Measuring Consumer Acceptance and Willingness-To-Pay for Specialty Tomatoes: Impact of Product, Taste, and Health Features

The increasing public health awareness and the promotion given to healthy eating habits as a measure to prevent obesity and chronic diseases have pushed consumer’s attention towards differentiated products. Many of the differentiated products, such as those with environmental, local, and other health and quality claims, are categorized as credence goods. Credence attributes, such as nutritional characteristics, are unobserved by consumers even after consumption, making the use of information crucial for marketing the benefits of such products. While there have been numerous studies examining the potential impacts of these attributes on consumer demand, few studies combine consumer valuation of credence attributes with sensory analysis of products and information treatments. This study attempts to shed more light on this area by considering both the impact of various attributes on consumer demand and the consistency in consumer valuation under different information treatments. The information treatments refer to tasting, health information, and the location of origin and production system of the products. A non-hypothetical second-price Vickrey auction was conducted in the Bryan-College Station area of Texas in order to collect the data. Several econometric models were developed to estimate consumers’ willingness-to-pay (WTP); however, special attention was paid to the random parameters tobit model as it accounts for unobserved individual heterogeneity as well as bid-censoring. Results show that knowledge of location of origin of tomatoes does have an impact on consumer valuation. The same holds true for the taste attribute (experience) and the health attribute (credence). Each information treatment was applied to several products and some treatments had contradictory results between products which prevented generalizing the effects of that treatment. In addition, estimates indicate there exists unobserved heterogeneity in valuations across individuals. Finally, using a Latent Class Analysis, consumers were segmented based on health-related behaviors, and the differences in the valuation of products and information treatments among those classes were measured using random parameters tobit models. Two latent classes were found and characterized as: “Health Conscious”, and “Health Redeemers”. The findings indicate that the classes differed significantly in terms of their preferences, willingness to pay, socio-economic profile, and health-driven motivations

Classification of air masses that affect the south of Santa Fe, their trajectories and the relationship between them to the the daily precipitation in January

El objetivo del trabajo es identificar las masas de aire que afectan el sur de Santa Fe durante los eneros de 1998-2006 y relacionarlas con la precipitación diaria, tomando como estación representativa a Zavalla (33º01´S, 60º53´O). La información diaria analizada es: temperaturas media, máxima y mínima, humedad relativa, heliofanía efectiva, presión atmosférica, precipitación y dirección de viento a las 8 y 14 horas local, campos de altura geopotencial en 1000 y 500 hPa, de temperatura en 1000 hPa y de humedad específica en 850 hPa del NCEP. Se aplica el algoritmo K-means y se identifican cuatro tipos de masas de aire: Cálida Seca (mCS): muy cálida; Cálida Húmeda (mCH): aumenta significativamente la humedad y la nubosidad respecto a mCS; Templada Seca (mTS): menores temperaturas mínimas; Templada Húmeda (mTH): muy húmeda, y bajas amplitudes térmicas diarias, asociada a condiciones previas al pasaje de frentes fríos. El 50% de días lluviosos ocurren durante mCH y el 32% con mTH, y el 93% de las más intensas acontecen durante el predominio de dichas masas. Las mTH tienen mayor eficiencia en la ocurrencia de precipitación pues en el 50% de los casos precipita, y para las mCH solo en el 27%.The aim of this work is to identify the air masses that affect the south of Santa Fe in January during 1998-2006 and to relate it to the daily precipitation, in Zavalla (33º01´S, 60º53´O). The analyzed daily information is: mean, maximum and minimum temperature, relative humidity, effective insolation, atmospheric pressure, precipitation and wind direction of the 8 and 14 hours. The fields of circulation and temperature in 1000 and 500 hPa, and specific humidity in 850 hPa, are calculated using NCEP Reanálisis data. Analysis of cluster k-means is applied and it determines four types of air masses: Warm Drought: a very warm air mass; Warm Humid: it increases the humidity and cloudiness, Moderate Dry: air mass with the smallest minimum temperatures; Moderate Humid: very humid air mass, daily losses thermal amplitude, associated to the previous conditions to the passage of cold fronts. The 50% of the precipitation days happen during Warm Humid masses and the 32% with Moderate Humid, and 93% of the most intense occurs during these masses. Moderate Humid have major efficiency in the precipitation occurrence because in 50% of the cases precipitates, and for Warm Humid only in 27%.Fil: Coronel, Alejandra S.. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias; ArgentinaFil: Castañeda, Maria Elizabeth. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ciencias de la Atmósfera y los Océanos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Flame burning speeds and combustion characteristics of undiluted and nitrogen-diluted hydrogen-nitrous oxide mixtures

In the present study, some explosive properties of undiluted and nitrogen-diluted H_2–N_2O mixtures were characterized. Laminar burning speeds and the explosion-induced pressure rises were determined experimentally for a range of mixture equivalence ratios (ϕ=0.15−1.0), dilutions (0-55%N_2) and initial pressures (20-80kPa). The measured burning speeds were used to validate laminar burning speed computations using a detailed chemical kinetic mechanism. The computations were then used to estimate burning speeds at high initial pressure and low dilution conditions that could not be measured experimentally. The results demonstrate that hydrogen–nitrous oxide mixtures exhibit laminar burning speeds as large as 350 cm/s and pressure rise coefficients (K_g) as large as 35 MPa m/s. Also, flames in lean mixtures are shown to be highly unstable which can lead to flame acceleration and possible deflagration-to-detonation transition

Dynamic scaling approach to study time series fluctuations

We propose a new approach for properly analyzing stochastic time series by mapping the dynamics of time series fluctuations onto a suitable nonequilibrium surface-growth problem. In this framework, the fluctuation sampling time interval plays the role of time variable, whereas the physical time is treated as the analog of spatial variable. In this way we found that the fluctuations of many real-world time series satisfy the analog of the Family-Viscek dynamic scaling ansatz. This finding permits to use the powerful tools of kinetic roughening theory to classify, model, and forecast the fluctuations of real-world time series.Comment: 25 pages, 7 figures, 1 tabl

Dynamics of ignition of stoichiometric hydrogen-air mixtures by moving heated particles

Studying thermal ignition mechanisms is a key step for evaluating many ignition hazards. In the present work, two-dimensional simulations with detailed chemistry are used to study the reaction pathways of the transient flow and ignition of a stoichiometric hydrogen/air mixture by moving hot spheres. For temperatures above the ignition threshold, ignition takes place after a short time between the front stagnation point and separation location depending upon the sphere's surface temperature. Closer to the threshold, the volume of gas adjacent to the separation region ignites homogeneously after a longer time. These results demonstrate the importance of boundary layer development and flow separation in the ignition process

Effects of differential diffusion on ignition of stoichiometric hydrogen-air by moving hot spheres

Studying thermal ignition mechanisms is a key step for evaluating many ignition hazards. In the present work, two-dimensional simulations with detailed chemistry are used to study the effect of differential diffusion on the prediction of ignition thresholds of a stoichiometric hydrogen-air mixture by moving hot spheres. Numerical experiments showed an increase of 40 K in the minimum ignition temperature required for ignition when diffusion of species at different rates is taken into account. Detailed analysis of the species profiles at the ignition location and a sensitivity study of the system to the diffusivity of H_2 and H revealed the key role played by the diffusion of H atoms in preventing ignition to take place at temperatures below 1000 K

Dynamics of ignition of stoichiometric hydrogen-air mixtures by moving heated particles

Studying thermal ignition mechanisms is a key step for evaluating many ignition hazards. In the present work, two-dimensional simulations with detailed chemistry are used to study the reaction pathways of the transient flow and ignition of a stoichiometric hydrogen/air mixture by moving hot spheres. For temperatures above the ignition threshold, ignition takes place after a short time between the front stagnation point and separation location depending upon the sphere's surface temperature. Closer to the threshold, the volume of gas adjacent to the separation region ignites homogeneously after a longer time. These results demonstrate the importance of boundary layer development and flow separation in the ignition process

Effects of differential diffusion on ignition of stoichiometric hydrogen-air by moving hot spheres

Studying thermal ignition mechanisms is a key step for evaluating many ignition hazards. In the present work, two-dimensional simulations with detailed chemistry are used to study the effect of differential diffusion on the prediction of ignition thresholds of a stoichiometric hydrogen-air mixture by moving hot spheres. Numerical experiments showed an increase of 40 K in the minimum ignition temperature required for ignition when diffusion of species at different rates is taken into account. Detailed analysis of the species profiles at the ignition location and a sensitivity study of the system to the diffusivity of H_2 and H revealed the key role played by the diffusion of H atoms in preventing ignition to take place at temperatures below 1000 K

Experimental investigation of spark ignition energy in kerosene, hexane, and hydrogen

Quantifying the risk of accidental ignition of flammable mixtures is extremely important in industry and aviation safety. The concept of a minimum ignition energy (MIE), obtained using a capacitive spark discharge ignition source, has traditionally formed the basis for determining the hazard posed by fuels. While extensive tabulations of historical MIE data exist, there has been little work done on ignition of realistic industrial and aviation fuels, such as gasoline or kerosene. In the current work, spark ignition tests are performed in a gaseous kerosene–air mixture with a liquid fuel temperature of 60°C and a fixed spark gap of 3.3 mm. The required ignition energy was examined, and a range of spark energies over which there is a probability of ignition is identified and compared with previous test results in Jet A (aviation kerosene). The kerosene results are also compared with ignition test results obtained in previous work for traditional hydrogen-based surrogate mixtures used in safety testing as well as two hexane–air mixtures. Additionally, the statistical nature of spark ignition is discussed