SOLUBILIZATION OF P-ALKYLPHENOLS IN PLURONICS F-68 AND F-127 MICELLES: PARTITION COEFFICIENTS AND EFFECT OF SOLUTE ON THE AGGREGATE STRUCTURE

Indexación: Web of Science; Scielo.The partition of a series of substituted phenols between water and polymer micelles formed by Pluronic F-68 and F-127 has been studied. The formation of micelles by these block copolymers has been evidenced by steady-state fluorescence and dynamic light scattering. The data show that micelles and larger aggregates are formed above the critical micelle concentration. In presence of p-alkylphenols a micelle rearrangement occurs that leads to the formation of just one and large aggregate. This effect depends both on polymer and phenols structures. The partition coefficients and the standard free energies of transfer from the aqueous to the micellar phases were determined. The incremental free energy for a methylene group are 2.88 kJ mol-1 and 1.65 kJ mol-1 for F-127 and F-68, respectively. This difference is explained in terms of the core sizes that are determined by the length of the PPO block.http://ref.scielo.org/xfqmx

An Empirical Analysis of the Impact of Home Foreclosure on the Crime Rate: Evidence in Atlanta, GA

Over the past 28 years the United States has seen its share of prosperity and hard times. At times there have been significant increases in the number of subprime mortgages issued in the United States. Studies have shown that the number of foreclosures is highly correlated to the number of subprime loans issued. Another main issue that seems to occur with the abundance of loans and the spike in foreclosures is that crime rates tend to also increase during these times. The two major crimes that will be taken into account are violent crime and property crimes. I use foreclosure, income, and crime data from various databases from 1980 to 2008. The purpose of this paper is to determine the relationship between United States foreclosure rates and crime rates. Results from simple regression models suggest that the increase in foreclosures is significantly related to crime level increases across the United States. I conclude with the discussion of implementing social and educational programs to help the less fortunate that are on the verge of losing their homes

A novel approach to reduce fire exposure and promote nature conservation in Mediterranean ecosystems: the case study of Reserva Natural da Serra da Malcata, Portugal

Mestrado Mediterranean Forestry and Natural Resources Management - Instituto Superior de Agronomia - ULIn Portugal, wildfires represent a major concern that yearly produces numerous economic and environmental losses. Currently, there is a continuous increase of biomass accumulation which increases wildfire risk into Mediterranean protected areas due to lack of management. An example is the protected area of Serra da Malcata, where prescribed burning has been implemented. However, fuel treatments implementation within preserved areas remains quasi forbidden in the major cases. The main objective is to develop and asses a novel approach to reduce fire exposure and simultaneously promote conservation habitat within Natura 2000 Habitats of Reserva Natural da Serra Malcata. For this aim, fire exposure assessment of three different fuel management scenarios: current situation, planned treatments and low intense treatments within Habitat Natura 2000 promoting conservation goals, were done by using burn probability modelling under extreme conditions for 24h burn period. Results showed similar performance of conservation enhancement scenario if compare with planned treatment scenario. Nevertheless, biggest fire exposure reductions were observed within Natura 2000 network. Limitations and assumptions derived from input parameters, model validation or fire simulator could affect fire exposure results. However, results open the debate to include fuel treatments within protected areas for achieving medium- and long-term fire risk reductio

Efficient and Accurate hybrid GO-Spectral Algorithm to Design Conformal Serrated-Edge Reflectors Operating as Collimators in Millimeter Wave Compact Ranges

This paper presents a hybrid analysis algorithm, which is used at Radiation Group (UPM) to carry out the design of a conformal serrated-edge reflector for the mm-Wave compact range UPM facility. Main features of this algorithm involve its capability of handling conformal serrated rim parabolic reflectors, accuracy and computational efficiency

Antenna Measurement System at 300 GHz for the Terasense Project

The aim of this paper is to introduce the design techniques used to develop the antenna measurement system for the Terasense Project. This project, funded by the Spanish Government, involves millimetre-wave systems design. One of these systems is an antenna measurement facility. The antenna measurement system operates in a banded range of frequency. The lower frequencies deal between 75–110 GHz (WR10 operation range) and the upper frequencies are set between 220–325 GHz (WR03). Among the different possible configurations, the reflector-based compact range is chosen. The quiet zone is generated by a serrated-edge reflector, fed by a low gain horn. In this paper we will focus on the reflector design. A serrations study is carried out and quiet zone acquisition results are obtained

Opportunities and benefits for increasing transmission capacity between the US eastern and western interconnections

Historically, the primary justification for building wide-area transmission lines in the US and around the world has been based on reliability and economic criteria. Today, the influence of renewable portfolio standards (RPS), Environmental Protection Agency (EPA) regulations, transmission needs, load diversity, and grid flexibility requirements drives interest in high capacity wide-area transmission. By making use of an optimization model to perform long-term (15 years) co-optimized generation and transmission expansion planning, this work explored the benefits of increasing transmission capacity between the US Eastern and Western Interconnections under different policy and futures assumptions. The model assessed tradeoffs between investments in cross-interconnection HVDC transmission, AC transmission needs within each interconnection, generation investment costs, and operational costs, while satisfying different policy compliance constraints. Operational costs were broken down into the following market products: energy, up-/down regulation reserve, and contingency reserve. In addition, the system operating flexibility requirements were modeled as a function of net-load variability so that the flexibility of the non-wind/non-solar resources increases with increased wind and solar investment. In addition, planning reserve constraints are imposed under the condition that they be deliverable to the load. Thus, the model allows existing and candidate generation resources for both operating reserves and deliverable planning reserves to be shared throughout the interconnections, a feature which significantly drives identification of least-cost investments. This model is used with a 169-bus representation of the North American power grid to design four different high-capacity wide-area transmission infrastructures. Results from this analysis suggest that, under policy that imposes a high-renewable future, the benefits of high capacity transmission between the Eastern and Western Interconnections outweigh its cost. A sensitivity analysis is included to test the robustness of each design under different future assumptions and approximate upper and lower bounds for cross-seam transmission between the Eastern and Western Interconnections

Environment Chamber for Shape-Memory Alloy Testing

The purpose of this project is to design, test, and build a temperature-controlled environment chamber to enable tensile testing of shape memory alloy (SMA) wire specimens at a temperatures ranging from 80-200°C. The most important design specifications were a maximum exterior wall temperature of 40°C and a maximum temperature variation along the specimen length of ±5°C, with end users\u27 ease- of-use considered. Hand calculations and iterative finite element analysis (FEA) simulations in SolidWorks were used to verify design choices before proceeding with sourcing parts and materials, and assembly. Real-world implementation of the system showed a heat-up time of roughly 25 minutes to 200°C (maximum operating temperature), with a maximum power consumption of 800 W, and with a wall temperature exceeding the safe threshold of 40°C only after 2 hours of continuous operation. The environment chamber and its accompanying hardware can be installed on a tensile testing machine and set up for use in under 10 minutes. Future work should entail heating wire specimens within the chamber and measuring the temperature variation along the specimen length, with the goal of achieving a maximum variation of ±5°C. If this criterion is met, then the environment chamber can be used to proceed with tensile testing of the SMA specimens

Numerical study of cullet glass subjected to microwave heating and SiC susceptor effects. Part II: Exergy transfer analysis

The mathematical model of exergy transfer in cullet glass heated by microwave inside of a cubical cavity with the aid of a susceptor is presented. Part I of this paper presented a numerical combined electromagnetic and heat transfer model by applying both transient Maxwell’s equations and heat transfer equations. Then, the electromagnetic and temperature fields were used to obtain the exergy transfer analysis in the oven. Exergy transfer analysis informs us about the efficiency of energy transformations taking place during the heating process, since it explains how the quality of the energy behaves along the heating process. The rate of internal exergy, exergy flowing and destroyed exergy were obtained and presented for this transient process. Part I showed that the susceptor location could change the temperature fields of cullet glass. So, an exergy analysis is important to understand the irreversibilities produced by a susceptor during preheating (microwaves activation) and heating process of the cullet glass, and how they could be minimized. Exergy transfer analysis shows how both, electromagnetic and heat transfer, are responsible of the irreversibilities generated in the heating process

Balanço energético e hídrico do aterro sanitário de Foz do Iguaçu

Anais do VI Encontro de Iniciação Científica e II Encontro Anual de Iniciação ao Desenvolvimento Tecnológico e Inovação – EICTI 2017 - 04 a 06 de outubro de 2017 - temática EngenhariaO Brasil apresenta um quadro agravante quanto à infraestrutura de serviços de saneamento, especialmente urbanos na utilização de sistemas adequados para a disposição final dos resíduos sólidos. Apenas do ano de 2010, institui-se a Lei Política Nacional de Resíduos Sólidos (PNRS), após ficar quase 21 anos tramitando no Congresso Nacional, sendo sua principal meta substituir os lixões a céu aberto por aterros sanitários como medida de proteção ambiental. Do ponto de vista de engenharia, os aterros sanitários são considerados como um local que permite o confinamento seguro dos resíduos sólidos, porém durante o processo de decomposição dos resíduos há a liberação de biogás, composto princi- palmente dióxido de carbono e gás metano que se liberados à atmosfera podem vir a contribuir para o agravamento do efeito estufaUniversidade Federal da Integração Latino-Americana (Unila); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Fundação Araucária; Parque Tecnológico Itaipu (PTI) e Companhia de Saneamento do Paraná (SANEPAR