A system for measuring liquid level in multiple tanks using optical fibe technology has been developed. Oil fiel service industry or any sector requiring liquid level measurements in flammabl atmospheres can be benefite from this intrinsically safe technology. The device used a single lens for the emitting and receiving fibe and it is based on amplitude variations as a function of the liquid distance and not in time of fligh or phase detection. Being the firs fiber-opti liquid level sensor with those characteristics for long ranges (>200 cm). A simple model to describe their behavior has been derived and tested on two prototypes. A Monte-Carlo method is used to fi the experimental data and obtain the model parameters. High accuracy between experimental data and fitte curve is obtained. The prototypes have a good linearity, better than 1.5% FS (full scale). Sensor heads are made of plastic optical fiber (POF) that are easy to handle, fl xible and economical. They are excited by 650 nm lasers, housed in ST-connectors to obtain compact and rough prototypes. Optical multiplexing is used to increase the measuring safety area. Frequency division multiplexing is used to address each sensor head. A discussion about the influenc of tilts and aberrations is also included.

Abstract-The device is based on a loop mirror in a ring resonator. The loop mirror allows tuning by changing the coupling coefficient of a directional coupler. The loop mirror is implemented using a Sagnac configuration to have the same optical path between the signals to be interfered (copropagating and counterpropagating ones). The filter structure allows optical integration for having higher free-spectral ranges. Simple design equations for the filter parameters and the tuning are reported. Measurements on a passive optical fiber tunable filter are presented. There is a good agreement between measurements and theory.

Abstract-General filter architecture using co-and counterpropagation signals are studied. A specific configuration based on a Sagnac loop within a ring resonator is analyzed. Novel tuning, apart from conventional tuning, is achieved by changing the coupling ratio of a coupler through the adjustment of the equivalent loop length. Full equations describing the filter behavior in passive and active configurations, and simple closed-form formulas to compute the tuning, tolerance, and full-width at half-maximum are reported. The performance of these devices is discussed for their application as selective or channel-dropping ultra-narrowband filters. The effect of losses and their dispersion properties are also discussed. These devices can be conveniently implemented, using silicon-or InP-integrated optic technology, for they have high free spectral ranges.

Background: in recent years Latin American countries have increasingly rejected the traditional prohibitionist paradigm of drug policy, reflecting its failure to reduce either consumption or trafficking. The extent to which these policy trends currently command pubic support is unclear, however. This article goes some way to filling this gap, providing a snapshot of public attitudes towards drug policies in nine Latin American countries. Methods: the 2014 Annual Survey of the Observatory of Drug Policies and Public Opinion, which has representative population samples, was used to measure public opinion. Country comparisons are made using descriptive and inferential statistics. Results: countries fall into three groups: Peru, Bolivia and El Salvador are the most conservative countries on drug policy and perceptions of risks of cannabis use; they also score lowest on Human Development Index. On the other hand, the public in Chile and Uruguay are more likely to support drug policy reform. The remaining four countries (Argentina, Colombia, Mexico and Peru) tend to occupy the middle ground between these extremes. In addition, cannabis legalization is explained by its recreational use, being this the main meaning attached to cannabis policy among Latin American citizens. Conclusion: There is a significant heterogeneity in attitudes towards drug policies in Latin American countries, which suggests that people are questioning the policies that set the norm in Latin America without achieving any consensus regarding future measures for each country.

In this study, we analyzed the association between public religiosity, private religiosity, and life satisfaction in a representative sample of the Chilean population. Religiosity was associated with low income and low socioeconomic status and with being older and female. These variables were negatively associated with satisfaction with life. However, attendance at collective religious rituals was associated with life satisfaction, while private religiosity was unrelated. These results support the view that it is the social aspect of religion that benefits well-being. Controlling for gender, age, and socioeconomic variables, public religiosity predicts life satisfaction. Participation in religious rituals was associated with high social support and affect balance (low negative and high positive affect). Mediational analyses that included all variables related to public religiosity (main predictor) and to life satisfaction (dependent variable) showed that attendance to religious rituals had a direct effect on well-being, and also a significant indirect effect on well-being through high social support and low negative affect. Results are discussed with respect to the role of public rituals in the Chilean collectivistic culture.