Do increasing prices affect food deprivation in the European Union?

The rise of prices of agricultural commodities in global markets during 2007-2012 was followed by increased consumer food prices around the world. More expensive food may have an impact on consumer food access and thus on their welfare, not only in developing countries but also amongst the most vulnerable in developed countries. Using a longitudinal database from the Statistics on Income and Living Conditions and population-averaged models, we tested whether increasing food prices had an impact on household food deprivation in 26 European Union (EU) member states. Results revealed a significant relationship between food deprivation and the consumer food price index and disposable income. Households in the lowest income quintile in the member states recently acceded to the EU were the most vulnerable to food deprivation. Results also showed that low-income households in densely populated areas were more vulnerable to food deprivation. This should be taken into account when evaluating food assistance programmes that focus on the segments of the population most at risk of food deprivation

Analysis of resolution in feedback signals for hardware-in-the-loop models of power converters

One of the main techniques for debugging power converters is hardware-in-the-loop (HIL), which is used for real-time emulation. Field programmable gate arrays (FPGA) are the most common design platforms due to their acceleration capability. In this case, the widths of the signals have to be carefully chosen to optimize the area and speed. For this purpose, fixed-point arithmetic is one of the best options because although the design time is high, it allows the personalization of the number of bits in every signal. The representation of state variables in power converters has been previously studied, however other signals, such as feedback signals, can also have a big influence because they transmit the value of one state variable to the rest, and vice versa. This paper presents an analysis of the number of bits in the feedback signals of a boost converter, but the conclusions can be extended to other power converters. The purpose of this work is to study how many bits are necessary in order to avoid the loss of information, but also without wasting bits. Errors of the state variables are obtained with di erent sizes of feedback signals. These show that the errors in each state variable have similar patterns. When the number of bits increases, the error decreases down to a certain number of bits, where an almost constant error appears. However, when the bits decrease, the error increases linearly. Furthermore, the results show that there is a direct relation between the number of bits in feedback signals and the inputs of the converter in the global error. Finally, a design criterion is given to choose the optimum width for each feedback signal, without wasting bit

LOCOFloat: A low-cost floating-point format for FPGAs.: Application to HIL simulators

One of the main decisions when making a digital design is which arithmetic is going to be used. The arithmetic determines the hardware resources needed and the latency of every operation. This is especially important in real-time applications like HIL (Hardware-in-the-loop), where a real-time simulation of a plant—power converter, mechanical system, or any other complex system—is accomplished. While a fixed-point gets optimal implementations, using considerably fewer resources and allowing smaller simulation steps, its use is very restricted to very specific applications, as its design effort is quite high. On the other side, IEEE-754 floating-point may have resolution problems in case of the 32-bit version, and excessive hardware usage in case of the 64-bit version. This paper presents LOCOFloat, a low-cost floating-point format designed for FPGA applications. Its key features are soft normalization of the results, using significand and exponent fields in two’s complement. This paper shows the implementation of addition, subtraction and multiplication of the proposed format. Both IEEE-754 versions and LOCOFloat are compared in this paper, implementing a HIL model of a buck converter. Although the application example is a HIL simulator, other applications could take benefit from the proposed format. Results show that LOCOFloat is as accurate as 64-bit floating-point, while reducing the use of DSPs blocks by 84%

Monitoring temperature on machining processes is enhanced using optical fibers

An IR fiber-optic pyrometer measures temperatures above 250 C close to rotating components where other sensing techniques are unsuitableThis work has been sponsored by the Spanish Ministry of Economy and Competitiveness under grant TEC2012-37983-C03-02.Publicad

AC mains synchronization loop for precalculated-based PFC converters using the output voltage measure

Common implementations of power factor correction include sensors for the input and output voltages and the input current. Many alternatives have been considered to reduce the number of sensors, especially the current sensor. One strategy is to precalculate the duty cycles that must be applied to every ac main, so the system only needs to synchronize them with the input voltage, and include a simple output voltage loop. The main problem with this approach is the sensibility to any synchronization error, because the input current is not measured, so its evolution is not continuously corrected. This paper shows how the synchronization error alters the current and the power factor, and it proposes several methods to detect and correct this error. All methods use the output voltage ADC, which is already used to control the output voltage, so the cost of the system is not increased. This technique can also be applied to any current sensorless PFC converter, because they are usually affected by leading or lagging currents, so the synchronization can be modified to reduce these effects. Results show that the implementation of this synchronization loop keeps a high-power factor under a wide synchronization error range, while the added logic is not significant.This research was funded by Spanish Ministerio de Economía y Competitividad grant number TEC2013-43017-R

Analyzing materials in the microscopes: From the Sorby thin sections up to the nondestructive large chambers

Proceedings of The Fifth Saudi International Meeting on Frontiers of Physics (SIMFP2016)One hundred and sixty five years ago, Henry Clifton Sorby developed a revolutionary technique to prepare thin and polished sections of rocks and minerals to be observed by transmission and reflectance in the optical polarized light microscopes. Nowadays, Sorby¿s methods are still employed for near all inorganic materials with scarce modifications. The optical microscopy subject is essential for rocks analysis; it is an irreplaceable technique for specific complex samples, such as twinned-exsolved feldspars and it must be preserved in the geosciences curriculum. However, for many valuable and common specimens we observe a strong growing of non-destructive techniques coupled to the large chambers of modern microscopes including new chemical, molecular, luminescent, metrical, imaging and structural probes. Suitable explanations for the thin sections decreasing in research laboratories could be: (i) the undesirable cutting of the specimen; (ii) the contamination of surfaces by abrasives and glues; (iii) the etching with dangerous acids; (iv) the slow and painful works of cutting, grinding and polishing specimens; (v) the necessary protection of valuable specimens, (vi) the need for immediate analytical results.Peer Reviewe

Validation of suspected somatic Single Nucleotide Variations in the brain of Alzheimer disease patients

Next-generation sequencing techniques and genome-wide association study analyses have provided a huge amount of data, thereby enabling the identification of DNA variations and mutations related to disease pathogenesis. New techniques and software tools have been developed to improve the accuracy and reliability of this identification. Most of these tools have been designed to discover and validate single nucleotide variants (SNVs). However, in addition to germ-line mutations, human tissues bear genomic mosaicism, which implies that somatic events are present only in low percentages of cells within a given tissue, thereby hindering the validation of these variations using standard genetic tools. Here we propose a new method to validate some of these somatic mutations. We combine a recently developed software with a method that cuts DNA by using restriction enzymes at the sites of the variation. The non-cleaved molecules, which bear the SNV, can then be amplified and sequenced using Sanger's technique. This procedure, which allows the detection of alternative alleles present in as few as 10% of cells, could be of value for the identification and validation of low frequency somatic events in a variety of tissues and diseases

Two-Color Pyrometer for Process Temperature Measurement During Machining

A fast fiber-optic two-color pyrometer operating on the optical communication bands is designed for temperature measurements in machining processes. Off-the-shelf low-loss fiber-optic demultiplexers and optoelectronics equipment are used in order to obtain a cost-effective sensing solution while reducing both the temperature measurement error and the minimum measurable temperature. The system is capable of measuring highly localized temperatures without using collimation lens. The designed pyrom-eter allows measuring temperature in the range from 300 to 650 °C, achieving a full-scale temperature error as low as 4%. Factors in-fluencing the temperature measurements are studied in order to identify the sensor limitations, such as a possible damage on the end of the optical fiber, the spectral loss attenuation and responsivity, or the distance between the fiber end and the target. Finally, this pyrometer is applied in a turning process, using a fiber-optic sensor embedded on a standard tool holder. Temperature measurements on the Inconel 718 are reported showing a good agreement with the simulations.This work was supported by the Spanish Ministry of Economía y Competitividad under Grants TEC2012-37983-C03-02, P2013/MIT-2790, and DPI2014-56137-C2-2-R.Publicad

Temperature Measurement and Numerical Prediction in Machining Inconel 718

Thermal issues are critical when machining Ni-based superalloy components designed for high temperature applications. The low thermal conductivity and extreme strain hardening of this family of materials results in elevated temperatures around the cutting area. This elevated temperature could lead to machining-induced damage such as phase changes and residual stresses, resulting in reduced service life of the component. Measurement of temperature during machining is crucial in order to control the cutting process, avoiding workpiece damage. On the other hand, the development of predictive tools based on numerical models helps in the definition of machining processes and the obtainment of difficult to measure parameters such as the penetration of the heated layer. However, the validation of numerical models strongly depends on the accurate measurement of physical parameters such as temperature, ensuring the calibration of the model. This paper focuses on the measurement and prediction of temperature during the machining of Ni-based superalloys. The temperature sensor was based on a fiber-optic two-color pyrometer developed for localized temperature measurements in turning of Inconel 718. The sensor is capable of measuring temperature in the range of 250 to 1200 °C. Temperature evolution is recorded in a lathe at different feed rates and cutting speeds. Measurements were used to calibrate a simplified numerical model for prediction of temperature fields during turning.This work was supported by the Spanish Ministry of Economy and Competitiveness and FEDER program under grants TEC2015-63826-C3-2-R and DPI2014-56137-C2-2-R, and from Comunidad de Madrid under grant S2013/MIT-2790