Química i Sostenibilitat

Quan es va decidir proclamar 2011 com l'Any Internacional de la Química, el aleshores Director General d'UNESCO va assenyalar que "Sensibilitzar al públic de la importància de les ciències químiques és una tasca de gran rellevància, pels reptes que ha d'afrontar el desenvolupament sostenible. És indubtable que la Química jugarà un paper molt important en el desenvolupament de fonts alternatives d'energia i l'alimentació de la creixent població mundial". Segons el president en aquests moments de l'IUPAC, amb aquesta celebració esperaven augmentar l'apreciació pública i la comprensió de la Química, augmentar l' interès dels joves per la ciència i generar entusiasme per un futur de creativitat relacionada amb la Química

A Semi-Distributed Electric Demand-Side Management System with PV Generation for Self-Consumption Enhancement

This paper presents the operation of an Electrical Demand-Side Management (EDSM) system in a real solar house. The use of EDSM is one of the most important action lines to improve the grid electrical efficiency. The combination between the EDSM and the PV generation performs a new control level in the local electric behavior and allows new energy possibilities. The solar house used as test-bed for the EDSM system owns a PV generator, a lead-acid battery storage system and a grid connection. The electrical appliances are controllable from an embedded computer. The EDSM is implemented by a control system which schedules the tasks commanded by the user. By using the control system, we define the house energy policy and improve the energy behavior with regard to a selected energy criterion, self-consumption. The EDSM system favors self-consumption with regard to a standard user behavior and reduces the energy load from the grid

Body image and self-esteem in children according to their nutritional status and frequency of physical activity

Indexación: Scopus; Scielo.La actividad física juega un papel importante en el desarrollo de los niños. El propósito de este estudio fue comparar según estado nutricional y frecuencia de actividad física la imagen corporal, autoestima, riesgo cardio-metabólico y rendimiento físico de niños. Se estudió 208 niños de 11,9±1,2 años de edad, 115 hombres y 93 mujeres. Quedaron divididos según frecuencia de actividad física a la semana: El Grupo 1 (n= 87) no realizan; Grupo 2 (n= 64) realizan 1 o 2 veces/semana; Grupo 3 (n= 57), realizan 3 o 4 veces/semana. Se observó que 51 niños presentaron sobrepeso y 40 de ellos obesidad. Los niños que realizan 3 o 4 veces actividad física/semana, presentaron menor preocupación por su imagen corporal y puntajes superiores en autoestima, ambas con significancia estadística (p<0,05), además reportaron menor riesgo cardio-metabólico y mejor rendimiento físico. Se concluye que los niños con mayor frecuencia de actividad física/semana, evidencian beneficios en su desarrollo integral.Physical activity plays an important role in child development. The purpose of this study was to compare body image, self-esteem, cardio-metabolic risk and physical performance of children by nutritional status and frequency of physical activity. We studied 208 children (115 men and 93 women) 11.9±1.2 years of age. Participants were divided by frequency of physical activity per week: Group 1 (n= 87) was not physically active; Group 2 (n= 64) was physically active 1 or 2 times per week; Group 3 (n= 57) was physically active 3 or 4 times a week. We observed that 51 children were overweight and 40 obese. Children who were physically active 3 or 4 times per week, were less concerned about their body image and had higher self-esteem scores (both p <0.05). These children also reported lower cardio-metabolic risk and better physical performance. We conclude that there are overall developmental benefits for children who are more physically active.http://ref.scielo.org/d2ddf

Comparative study of PCR-sexing procedures using bovine embryos fertilized with sex-sorted spermatozoa

Sex determination in bovine embryos is a useful tool in reproductive biotechnology. This work compares two techniques of embryo sexing by polymerase chain reaction (PCR. Embryos were produced in vitro with sex-sorted sperm and two techniques of DNA lysis were tested (proteinase K versus heat shock). Subsequently, halves of each lysed sample was amplified both by amelogenin and BRY4a/SAT1 primers. Male embryos treated by both digestion methods and amplified by BRY4a/SAT1 gave higher rates of false negatives. Amelogenin amplification failed with embryos previously digested by proteinase K. In contrast, the lysis method allowed obtaining the best accuracy in terms of sex verification when using amelogenin amplification

III Seminario Ibérico CTS en la Enseñanza de las Ciencias

Reseñ

Structure of superheavy hydrogen 7H

The properties of nuclei with extreme neutron–to–proton ratios reveal the limitations of state-ofthe-art nuclear models and are key to understand nuclear forces. 7H, with six neutrons and a single proton, is the nuclear system with the most unbalanced neutron–to–proton ratio ever known, but its sheer existence and properties are still a challenge for experimental efforts and theoretical models. We report here the first measurement of the basic characteristics and structure of the ground state of 7H; they depict a system with a triton core surrounded by an extended four-neutron halo, built by neutron pairing, that decays through a unique four–neutron emission with a relatively long half-life. These properties are a prime example of new phenomena occurring in almost pure-neutron nuclear matter, beyond the binding limits of the nuclear landscape, that are yet to be described within our current models

PV self-consumption optimization with storage and Active DSM for the residential sector

With the rising prices of the retail electricity and the decreasing cost of the PV technology, grid parity with commercial electricity will soon become a reality in Europe. This fact, together with less attractive PV feed-in-tariffs in the near future and incentives to promote self-consumption suggest, that new operation modes for the PV Distributed Generation should be explored; differently from the traditional approach which is only based on maximizing the exported electricity to the grid. The smart metering is experiencing a growth in Europe and the United States but the possibilities of its use are still uncertain, in our system we propose their use to manage the storage and to allow the user to know their electrical power and energy balances. The ADSM has many benefits studied previously but also it has important challenges, in this paper we can observe and ADSM implementation example where we propose a solution to these challenges. In this paper we study the effects of the Active Demand-Side Management (ADSM) and storage systems in the amount of consumed local electrical energy. It has been developed on a prototype of a self-sufficient solar house called “MagicBox” equipped with grid connection, PV generation, lead–acid batteries, controllable appliances and smart metering. We carried out simulations for long-time experiments (yearly studies) and real measures for short and mid-time experiments (daily and weekly studies). Results show the relationship between the electricity flows and the storage capacity, which is not linear and becomes an important design criterion

Application Domain Study of Evolutionary Algorithms in Optimization Problems

ABSTRACT This paper deals with the problem of comparing and testing evolutionary algorithms, that is, the benchmarking problem, from an analysis point of view. A practical study of the application domain of four representative evolutionary algorithms is carried out using a relevant set of real-parameter function optimization benchmarks. The four selected algorithms are the Covariance Matrix Adaptation Evolution Strategy (CMA-ES) and the Differential Evolution (DE), due to their successful results in recent studies, a Genetic Algorithm with real parameter operators, used here as a reference approach because it is probably the most familiar to researchers, and the Macroevolutionary algorithm (MA), which is not widely known but it shows a very remarkable behavior in some problems. The algorithms have been compared running several tests over the benchmark function set to analyze their capabilities from a practical point of view, in other words, in terms of their usability. The characterization of the algorithms is based on accuracy, stability and time consumption parameters thus establishing their operational scope and the type of optimization problems they are more suitable for

Experimental investigation of ground-state properties of 7H with transfer reactions

The properties of nuclei with extreme neutron–to–proton ratios, far from those naturally occurring on Earth, are key to understand nuclear forces and how nucleons hold together to form nuclei. 7H, with six neutrons and a single proton, is the nuclear system with the most unbalanced neutron–to–proton ratio known so far. However, its sheer existence and properties are still a challenge for experimental efforts and theoretical models. Here we report experimental evidences on the formation of 7H as a resonance, detected with independent observables, and the first measurement of the structure of its ground state. The resonance is found at ∼0.7 MeV above the 3H+4n mass, with a narrow width of ∼0.2 MeV and a spin and parity. These data are consistent with a 7H as a 3H core surrounded by an extended four-neutron halo, with a unique four-neutron decay and a relatively long half-life thanks to neutron pairing; a prime example of new phenomena occurring in what would be the most pure-neutron nuclear matter we can access in the laboratory.Spanish Ministerio de Economía y Competitividad under contracts FPA2009–14604–C02–01 and FPA2012–39404–C02–01

Identification of new transitions and mass assignments of levels in 143−153^{143-153}Pr

The previously reported levels assigned to 151,152,153Pr have recently been called into question regarding their mass assignment. The above questioned level assignments are clarified by measuring g-transitions tagged with A and Z in an in-beam experiment in addition to the measurements from 252Cf spontaneous fission (SF) and establish new spectroscopic information from $N=84$ to $N=94$ in the Pr isotopic chain. The isotopic chain 143-153Pr has been studied from the spontaneous fission of 252Cf by using Gammasphere and also from the measurement of the prompt g-rays in coincidence with isotopically-identified fission fragments using VAMOS++ and EXOGAM at GANIL. The latter were produced using 238U beams on a 9Be target at energies around the Coulomb barrier. The g-g-g-g data from 252Cf (SF) and those from the GANIL in-beam A- and Z-gated spectra were combined to unambiguously assign the various transitions and levels in 151,152,153Pr and other isotopes. New transitions and bands in 145,147,148,149,150Pr were identified by using g-g-g and g-g-g-g coincidences and A and Z gated g-g spectra. The transitions and levels previously assigned to 151,153Pr have been confirmed by the (A,Z) gated spectra. The transitions previously assigned to 152Pr are now assigned to 151Pr on the basis of the (A,Z) gated spectra. Two new bands with 20 new transitions in 152Pr and one new band with 7 new transitions in 153Pr are identified from the g-g-g-g coincidence spectra and the (A,Z) gated spectrum. In addition, new g-rays are also reported in 143-146Pr. New levels of 145,147-153Pr have been established, reliable mass assignments of the levels in 151,152,153Pr have been reported and new transitions have been identified in 143-146Pr showing the new avenues that are opened by combining the two experimental approaches.Comment: Accepted in Phys. Rev.