Energetic Behavior Research Articles

Intense Precipitation and Area of Risk: A Case Study of Mass Movement in the City of Natal, Brazil

This study aims to analyze the atmospheric conditions associated with an event of intense precipitation caused by Easterly Wave Disturbances (EWDs), as well as the environmental conditions related to the mass gravitational movement that occurred between 14th June and 15th June of 2014, in the district of Mãe Luiza, Natal/RN/Brazil. The synoptic conditions, the vertical integrated moisture flux and the energetic behavior in the EWD’s performance phases were analyzed. In addition to these factors, local environmental aspects were assessed, classifying the vulnerability to disaster events in the affected area. Over the days of the operation of the atmospheric system, the daily accumulation of precipitation was greater than 100 mm, with precipitation accumulated in 3 h in the order of 60 mm for the stages of maturation of the disturbance. The main synoptic conditions associated with EWDs were exhibited by the intense anomalies of wind speed and high humidity flux on the east coast of the Northeast, which intensified the influx of moisture into the continent over the period of the operation of the system. Conditions of high to very high vulnerability were identified in the area where the event took place and also in other expressive parts of the district.

Thermodynamics of strain-induced crystallization in filled natural rubber under uni- and biaxial loadings, Part I: Complete energetic characterization and crystallinity evaluation

The present paper provides the first full thermo-mechanical characterization of a crystallizing filled natural rubber under uniaxial and biaxial loadings. During the mechanical tests, the temperature was measured by using infrared thermography and processed by means of the heat diffusion equation for determining the corresponding heat power density. The intrinsic dissipation due to viscosity and stress softening are evaluated under cyclic loading by the energy balance. Energy contributions to the hysteresis loop converted into heat and stored in the material are distinguished. The heat power density is also used to evaluate the strain-induced crystallinity. This analysis provides new results on the energetic behavior of filled natural rubber. Accordingly, crystallization takes place under high biaxiality levels, close to the equibiaxial loading condition, while multiaxiality influences the crystallization onset. These experimental results are used in the second part of the present paper for a physically based modeling of the complex behavior of filled natural rubbers.

An Integrated Approach to Improve Seismic and Energetic Behaviour of RC Framed Buildings Using Timber Panels

In the present paper, an integrated intervention system applicable to concrete-framed buildings is presented. The purpose of the intervention is to improve both the seismic and the energetic behaviour of such buildings using cross-laminated timber (CLT) panels. Two alternative intervention configurations with different levels of invasiveness are described. Considering a double-wythe masonry-infilled frame, the most invasive configuration consists in the replacement of the external masonry wythe with the CLT panel, while the least invasive configuration consists in the arrangement of the CLT panel from the outside without removing the wythes. The technical details and implementation procedures were studied, considering functionality and disturbance to occupants. An isolated one-storey-one-bay frame was used as a reference for the seismic and thermal analyses. Subsequently, the two intervention configurations were applied to a case-study building by identifying two alternative intervention strategies. The obtained results showed that the proposed integrated intervention approach can significantly reduce both the seismic vulnerability and the energy consumption of concrete buildings.

Metabolic and behavior responses of lactating goats under heat stress

Heat stress (HS) negatively affects animal performance, but little is known about energetic metabolism and behavior changes in dairy goats under HS conditions. Eight multiparous Murciano-Granadina dairy goats (43.3 ± 1.6 kg BW; 2 ± 0.04 L milk/d; 81 ± 3 days of lactation) were kept in metabolism cages and randomly assigned to two treatments varying in the temperature humidity index (THI). The design was crossover (two 28-d periods), and treatments were: 1) thermal neutral (TN; 15–20C, 40–45% humidity, THI = 59–65), and 2) heat stress (HS, 12 h/d at 37°C and 40%, and 12 h/d at 30°C and 40%, THI = 86 and 77, respectively). Jugular silicon catheters were fitted, and glucose tolerance test (0.25 g/kg BW), insulin tolerance test (4.6 μg/kg BW) and epinephrine challenge (2 μg/kg BW) were conducted. Before and after each metabolite administration, blood samples were collected for the analysis of insulin, glucose, and nonesterified fatty acids (NEFA). Also, behavior variables (position changes, duration of remaining standing, as well as eating and drinking bouts and duration) were observed at day 3 of each period by video cameras. Heat stress reduced (P < 0.01) feed intake (−29%), milk yield (−10%), milk fat (–12%), milk protein (–14%), and milk casein (–13%). Goats in both groups had similar blood NEFA after insulin administration, but NEFA values were greater (P < 0.05) in TN than HS goats after epinephrine infusion. The HS goats secreted lower (P < 0.05) amounts of insulin than TN goats in response to the glucose tolerance test. Additionally, TN and HS goats had similar number of eating bouts, but the duration of each bout was shorter in HS than in TN. Also, HS had greater number of drinking bouts with no differences in drinking bout durations between groups. In conclusion, body lipid tissue of HS goats became more resistant to lipolysis, making them unable to mobilize body fat reserves despite the negative energy balance. In addition, the reduction in feed intake by HS was because of the shorter time of eating bouts, whereas the greater water consumption was related to the increase in drinking bouts.

Applications of thermodynamics to study the physical phenomenon of heat conduction

Thermodynamics can be understood as the discipline of the physical sciences, that studies theoretically and practically the different manifestations of energy. The study of thermodynamics is important in relation to the understanding of thermal systems in industry, as well as, supporting energetic processes in living organisms. In relation to the study of energy processes in the context of heat transfer, concepts from thermodynamics are relevant. In the present investigation, the process of heat conduction in a metal bar is analyzed by applying the heat equation and the concept of entropy variation. The first part of the research proposes a numerical method to solve the heat equation in addition to a set of finite difference equations describing the energetic behavior of the system. The numerical solution of the heat equation and the thermodynamic behavior of the system are studied by programming to demonstrate the fit of the results with the theoretical models. Finally, applications of the achieved results in engineering contexts are discussed.

Timber Based Integrated Techniques to Improve Energy Efficiency and Seismic Behaviour of Existing Masonry Buildings

The retrofit solutions studied herein aim to improve the seismic and energetic behaviours of existing masonry buildings to guarantee safety and the preservation of the building heritage. The retrofit consists of timber-based products (panels and strong-backs) fixed to the masonry walls using mechanical point-to-point connections; the durability and the hygrothermal performance of the solutions are guaranteed by insulation layers and membranes. The thermophysical properties of the retrofitted walls were evaluated by means of analytical and numerical analyses, considering the heat transmission in both steady and unsteady state conditions and the thermal bridge in correspondence with the corner of the wall. The in-plane seismic behaviour of the retrofitted walls was numerically investigated through nonlinear analyses. The influence of various parameters (such as masonry and insulation properties) on the performance of the retrofit solutions was analysed via parametric simulations.

Comprehensive analysis of the variables influencing the techno-economic optimization of medium temperature linear Fresnel collectors

A Linear Fresnel Collector (LFC) is a solar concentrating technology with high potential for improvements and therefore significant cost reduction. However, LFC optimization studies found in literature show little agreement regarding optimal geometry. In this article, a study is presented to evaluate the trends of the main geometrical parameters in an optimization process of medium temperature linear Fresnel collectors (LFCs) with trapezoidal receiver. For this, a comprehensive LFC design model was developed. It includes an optical, a thermal, an annual integration of the collected energy and an economic sub-models coded in a hard-link way. This model was used to investigate the influence of the main LFC geometrical parameters and inputs on the levelized cost of heat (LCOH) produced. The geometrical parameters investigated were the number of mirrors, the width of mirrors, the gap between mirrors, the trapezoidal angle and the trapezoidal height of the receiver, while the inputs investigated were the location (Quito-Ecuador and Targassone-France), DNI data (TMY data and clear sky model) and the time frame of simulation (representative days or the whole year). Results show that the optimal LFC geometry depends mainly on the azimuthal movement of the Sun. Consequently, the trends of the energetic behavior of an LFC, when the geometrical parameters vary, are similar without regard of the latitude, DNI data or the time frame used for simulations. Reductions until 20% on the LCOH may be achieved by optimizing the geometry of such LFC.

Classroom Space and Creative Student Engagement: A Focus on the Sri Lankan Drama Classroom

Effective drama teaching and learning needs physical space: space for performance, expression, interaction and exploration. However, the Sri Lankan classroom environment remains largely unexplored in terms of investigating the relationship between the physical classroom environment and the teaching and learning of drama when process drama is the method of instruction. This article is based on the findings of a non-randomised control group intervention study, which involved forty classroom observations in secondary schools in Sri Lanka. The observations showed that students who were able to use the school’s open-air theatre for the entire intervention period engaged in far more collaborative, energetic, performative and creative behaviours than other classes who were in a confined classroom space with desks and chairs crammed closely together. Implications for the teaching of drama by different methods are discussed in the Sri Lankan context.

A Review of Smart and Responsive Building Technologies and their Classifications

The high impact of the building sector on global greenhouse gases (GHG) emissions, has focused the attention on the energetic behaviour of the built environment. Starting from the second half of 20th century an increasing attention on the insulation of building envelopes has been paid trying to maximize the indoor-outdoor disconnection. Nowadays, one of the main deficiencies of traditional buildings lies in the rivalry between their static behaviour and the dynamic external environment. The increasing awareness that responsive buildings can provide significant improvements in energy efficiency and internal comfort has recently led to a quick spread of innovative technologies, tools, and research topics. The aim of this review is to provide a broad overview of the available and most promising responsive technologies applied to highly performant buildings with a particular focus on building envelopes. Firstly, an introduction of the energy context and of the spread of adaptive technology is presented. Then, an analysis of the existing nomenclature and classification systems is provided to introduce the detailed review of the technologies.

Spectroscopic characterization and binding interaction of heavy metal onto the surface receptor of the azobenzene: DFT and experimental approach

The azobenzene 1-arylazo-2-naphthol has been synthesized and characterized by elemental analysis, 1H NMR, IR and UV–Vis spectroscopies using both experimental and theoretical methods. The MEP, NPA and FMOs have also been performed at the DFT/B3LYP-D3 level with different solvents in order to investigate the solvent's effect. The energetic behavior of the compound has been examined in the gas phase and in solvent media using the integral equation formalism polarizable continuum model (IEF-PCM). Solvents had sligth significant effect on NPA values whereas both molecules hardness and stability decrease along with increasing of the solvent's polarity. Vibrational and absorption analysis showed no significant azo±hydrazone tautomerism. Theorically, the title molecule calculated in Acetonitrile solvent is the most reactive. The observed red shifts are explained by the large extension of the π conjugated system and the blue shifts confirm the appearance of several tautomeric forms of the studied azo-benzene which lead to a marked improvement in photochemical stability. The cation binding properties of azo benzene as absorption sensor for Cu2+, Mg2+, Ni2+ and Zn2+ cations were reported. The highest adsorption energy in both gas and liquid phase corresponds to the complexes Azoic/Ni2+ then in Azoic/Cu2+ and somewhat in Azoic/Zn2+complex. The lowest adsorption energy is given to Azoic/Mg2+ complex. After cations chemisorption on azoic molecule a bathochromic shift is observed in the optical spectra, particularly for Azoic/Ni2+ complex, which is the proof of interaction between azoic compound and mentioned cations. The electronic proprieties and the vibrational spectra can therefore be used to detect the presence of different cations and the azobenzene shows appropriate properties to constitute good cations (Ni2+ and Cu2+) sensors.

Empirical validation of a multizone building model coupled with an air flow network under complex realistic situations

Building energy simulation (BES) assesses the energetic and thermal behaviour of buildings and can be used for the evaluation of energy conservation measures (ECMs). However, building modelling under realistic conditions can be challenging for simulation programs. The aim of this work is to test whether a multizone building model developed with a simulation tool can handle the complex situations of an in-use building. Monitoring data from the Twin Houses empirical validation experiment of the International Energy Agency, Energy in Buildings and Communities (IEA EBC) Annex 71 is used for that purpose. The multizone building model is developed with the energy simulation software TRNSYS coupled with an air flow network in TRNFLOW. The innovative aspect of this work lies in the validation of a combined multizone building model under stochastic occupancy gains, taking into account room-wise heating profiles, ventilation, and interior air flow currents due to window and door operation. The results of a coheating test showed that the errors in the simulated heating power for the whole house are a coefficient of variation of the root mean square error (CV(RMSE)) of 12.72% and a normalised mean bias error (NMBE) of −8.35%. Nevertheless, more difficulties were found in separately predicting the heating power of each individual room. However, the combined multizone air flow model was able to predict indoor temperatures in all rooms with root mean square error (RMSE) and mean absolute error (MAE) values of<1 °C.

Energetic particle behavior in near-Sun magnetic field switchbacks from PSP

Context. The observation of numerous magnetic switchbacks and associated plasma jets in Parker Solar Probe (PSP) during its first five orbits, particularly near the Sun, has attracted considerable attention. Switchbacks have been found to be systematically associated with correlated reversals in the direction of the propagation of Alfvénic fluctuations, as well as similar reversals of the electron strahl. Aims. Here we aim to see whether the energetic particles change direction at the magnetic field switchbacks. Methods. We use magnetic field data from the MAG suite’s fluxgate magnetometer instrument to identify switchback regions. We examine the radial anisotropy of the energetic particles measured by the EPI-Lo instrument of the IS⊙IS suite. Results. We find that energetic particles measured by EPI-Lo generally do not preferentially change their directionality from that of the background magnetic field to that of the switchbacks. Conclusions. A reasonable hypothesis is that particles with smaller gyroradii, such as strahl electrons, can reverse direction by following the magnetic field in switchbacks, but that larger gyroradii particles cannot. This provides the possibility of setting a constraint on the radius of the curvature of the magnetic field in switchbacks, a property not otherwise observed by PSP. We expect that particles at higher energies than those detectable by EPI-Lo will also not respond to switchbacks. The observed reversals of radial energetic particle flux are separate phenomena, likely associated with source locations or other propagation effects occurring at greater radial distances.

Effect of the wavy tank wall on the characteristics of mechanical agitation in the presence of a Al2O3-water nanofluid

The enhancement of the heat transfer in the stirred tank is a much-desired objective for accelerating certain physical and chemical parameters in the industrial field. From this basis, an attempt is made in this paper to investigate the effect of the wavy wall of a stirred tank on the hydrodynamic, thermal, and energetic behavior of an Al2O3-Water nanofluid. The stirred tank has a flat bottom, and it is equipped with an anchor stirrer. A hot temperature has been imposed on the tank wall, and the agitator has been assumed adiabatic, where the nanofluid has a cold temperature at the initial instant. The laminar flow was governed by the equations that describe the forced convection, and it was solved by the finite element method. The numerical simulation results showed a considerable acceleration in the heat transfer inside the stirred tank by increasing the amplitude of the wavy wall and increasing the nanoparticle concentration. However, there has been a remarkable increase in the stirring power number. This contribution aims to increase thermal efficiency, especially in the chemical and petrochemical fields, to obtain a better yield of certain chemical reactions and mass transfer depending on the heat.

Synthesis and Characterization of Geminal Diazido Derivatives Based on Diethyl Malonate

AbstractNew geminal diazide derivatives based on diethyl 2,2‐diazidomalonate (1) are presented. 2,2‐Diazidomalonic acid (2) as well as four alkaline and nitrogen rich salts of 2,2‐diazidomalonate (3–6) were synthesized and extensively characterized e. g. by low temperature X‐ray diffraction. All compounds, which represent promising starting materials for further nitrogen‐rich materials, were analyzed by 1H and 13C NMR spectroscopy, elemental analysis, differential thermal analysis (DTA) and regarding their sensitivity towards impact, friction, and electrostatic discharge according to BAM standard techniques. In addition, all synthesized compounds were evaluated regarding their energetic behavior using the EXPLO5 code and compared to TNT in order to provide a comparison to a well‐known energetic material. In addition, two selected compounds were investigated towards their aquatic toxicity, using the bioluminescent bacteria vibrio fischeri.

Investigation of structural and energetic behavior of 55-atom Pt–Ag–Au ternary nanoalloys

A systematic theoretical investigation of structural and energetic behaviors of 55-atom Pt–Ag–Au ternary nanoalloys has been performed in two different composition systems. We have performed Gupta and Density Functional Theory (DFT) approaches on chosen systems. The Basin-Hopping algorithm is used for structural optimizations of PtnAg[Formula: see text]Au[Formula: see text] ([Formula: see text]–13) and PtnAu[Formula: see text]Ag[Formula: see text] ([Formula: see text]–13) ternary nanoalloys with Gupta many-body potential to model interatomic interactions. Local optimization results show that while the tendency of Au atoms to be located varies according to the composition system, the tendency of Pt and Ag atoms to be located does not change in both. For all compositions of Pt–Ag–Au nanoalloys, the structures with the best chemical ordering were then reoptimized by DFT relaxations and the mixing energies of the Gupta and DFT levels were compared. Our mixing energy analysis showed that PtnAg[Formula: see text]Au[Formula: see text] ([Formula: see text]–13) nanoalloys are not energetically suitable for mixing at both Gupta and DFT level. Also, mixing energy variations of PtnAu[Formula: see text]Ag[Formula: see text] ([Formula: see text]–13) nanoalloys obtained at Gupta level does not agree with the one obtained at DFT level. In addition, it has been found that the minimization energy changes when an atom in the central site is exchanging by an atom in the second shell and surface.

Energetic Behavior Study in Phase Transformations of High Temperature Cu–Al–X (X: Mn, Te, Sn, Hf) Shape Memory Alloys

Shape memory alloys (SMAs) are increasingly used in a wide range of thermomechanical and thermoelectric applications that are of a macro-, micro- and nano-scale. Though the use of commercial Ni–Ti (NiTiNOL) SMAs is preferred in most of these applications, there is an ever-increasing demand for cost-effective and easy-to-produce alternatives to NiTiNOL. In terms of functional properties, copper-based SMAs are comparable to Ni–Ti SMAs. Moreover, Cu-based SMAs are cheaper and easier to produce and process. In order to improve the functional properties of binary Cu-based SMAs (Cu–Al, Cu–Zn and Cu–Sn), ternary elements are added in small quantities. This is also one of the most common methods that is used to improve the functional properties of NiTi- and Fe-based SMAs. In this work, Cu–Al-based alloys containing ternary elements, Mn, Sn, Te and Hf, were produced by arc melting technique. Thermal (DSC, DTA) and microstructural (XRD, metallography) analyses were then carried out on the alloys prepared so as to characterize them for their thermal and microstructural characteristics. The results demonstrate improved shape memory properties for these alloys. The transformation temperatures of the binary Cu–Al alloys determined showed higher values (Af > 100 °C). Among the ternary alloys, the highest transformation temperatures were found for alloys with Hf addition, followed by those with Te addition. But on the other hand, the most intense peaks corresponding to the martensitic transformation were observed for Sn addition. The microstructural investigations revealed the presence of martensite in the alloys which was consistent with the results of thermal analysis.

Solar orbiter: mission to study the sun [Space innovation

Designing a spacecraft that can image the Sun as closely as possible without melting the delicate instruments has been a challenge. But scientists' luck could be about to change.LAUNCHED IN February 2020 from Cape Canaveral, a 1.7-tonne spacecraft called the Solar Orbiter aims to get up-close images of the Sun from 42 million kilometres away, while measuring its energetic behaviour in real-time. The suite of 10 on-board instruments will enable it to uniquely marry the study of events in the Sun's gaseous corona, measure its magnetic fields, and sample the solar wind as it flows past the spacecraft as a stream of energetic particles.

Evolved changes in maternal care in high-altitude native deer mice.

At high altitude (HA), unremitting low oxygen and persistent cold push small mammals close to their metabolic ceilings, leaving limited scope for aerobically demanding activities. However, HA breeding seasons are relatively short and endemic rodents compensate with larger litters than low altitude (LA) conspecifics. Rodent mothers are the sole source of heat and nutrition for altricial offspring and lactation is energetically costly. Thus, it is unclear how HA females balance energy allocation during the nursing period. We hypothesized that HA female rodents invest heavily in each litter to ensure postnatal survival. We measured maternal energetic output and behaviour in nursing deer mice (Peromyscus maniculatus) native to LA (400 m a.s.l.) and HA (4350 m a.s.l.) under control (24°C, 760 mmHg) and cold hypoxia conditions, simulating HA (5°C, 430 mmHg). Strikingly, resting metabolic rates of lactating HA and LA females under cold hypoxia were 70-85% of their maximum aerobic capacity. In cold hypoxia, LA mothers increased both nursing time and milk fat content, however their pups were leaner and severely growth restricted at weaning. HA mothers also increased nursing in cold hypoxia but for far less time than LA mothers. Despite receiving less care, HA pups in cold hypoxia only experienced small growth restrictions at weaning and maintained body composition. As adults, HA mice raised in cold hypoxia had increased aerobic capacity compared to controls. These data suggest that HA mothers prioritize their own maintenance costs over investing heavily in their offspring. Pups compensate for this lack of care, likely by reducing their own metabolic costs during development.

Emissions and energy consumption of a plug-in hybrid passenger car in Real Driving Emission (RDE) test

In the next years, the number of circulating plug-in hybrid electric vehicles was expected to increase worldwide. Hybrid electric/gasoline powertrain is considered a promising solution to meet the future goals of greenhouse gas emission reduction by road transport sector. This paper investigates the emissive and energetic behaviour of a plug-in hybrid electric passenger car over on road testing. Measurements of CO, CO2, NOx exhaust emissions and of main electric motor parameters were carried out by using portable emission measurement system over urban, rural and motorway routes in Naples (Italy). Routes were selected for complying with European Real Driving Emission (RDE) legislation. Moreover, an additional urban route, characterised by strong road grade and non-RDE compliant, was investigated. RDE test allowed to assess the influence of the battery state of charge, hybrid mode (charge sustaining and charge depleting), road grade and vehicle air conditioning on the exhaust emission and energy consumption. An overall advantage of charged battery and charge depleting mode was observed in terms of CO2 emissions and fuel consumption. CO and NOx emissions are strongly influenced by driving when the vehicle's internal combustion engine starts. When it occurs in motorway patterns, CO and NOx peak emissions are observed at tailpipe. Pure electric driving, with consequent zero emissions, are guaranteed over urban strong uphill when battery is full charged.

Energy Component Analysis of Electric Field-Induced Shape Change in Water Nanodroplets

We present a comprehensive classical molecular dynamics study of water nanodroplets under the influence of an externally applied electric field. Our simulations cover a wide range of droplet sizes and electric field strengths, which allows for a thorough exploration of the structural and energetic behavior of nanodroplets in the presence of an external electric field. Our analysis reveals the molecular-level mechanism behind the shape extension of a nanodroplet from a spheroid to a highly prolate ellipsoid as the propensity of the water dipoles to align with the electric field while simultaneously restructuring to minimize the dipole–dipole interaction energy. We also develop a quantitative theory that describes the energetic landscape for the nanodroplet shape extension process and allows predictions of the nanodroplet behavior based on its initial size and the strength of the applied field.