Effects Of Local Conditions Research Articles

Mixed convection around two vertically aligned horizontal cylinders: A numerical, experimental, and modeling investigation on the effect of local conditions on heat transfer

Experimental and numerical studies were performed to assess the effects of buoyancy driven flows from lower cylinders in a tube array on the heat transfer of higher-elevation cylinders. First, PIV and LIF experiments were performed for a single 13.4 mm diameter cylinder submerged in water at atmospheric conditions to measure velocity and temperature fields. Then the effect of buoyancy from a lower heater was studied by arranging two horizontal cylinders at different vertical displacements from each other (P/D = 1.5, 2.15, 6.45). Wall temperatures were measured as a function of pitch and power. CFD analysis was performed for the same configurations using an LES model. Using a combination of CFD and experimental measurements, mechanistic models for velocity and temperature behaviour in the plume were developed. These models are used to determine the impact of buoyant plumes from cylinders at lower elevations on heat transfer from heated cylinders at higher elevations. Since the plumes from cylinders at lower elevation are imposed on the natural convection from higher-elevation cylinders there is a combined effect from the momentum and temperature of the lower plume as it interacts with the natural convection phenomena from the upper-elevation heater. A model to predict the NuD of the upper cylinder in the case of horizontal vertically aligned pair of tubes was developed based on superposition of the convection caused by the lower cylinder and the natural convection from the higher-elevation cylinder. This model was found to predict the cylinder NuD with an RMS error of 2.8 and an absolute deviation of 2.31 as compared to the experimental data obtained in this study. It was also found to agree well with independent data available in literature.

Data Assimilation Using WRFDA Over the Terminal Area of Rio de Janeiro

Abstract The impact of the data assimilation process of air temperature and relative humidity from surface meteorological stations and sounding at airports in the terminal area of Rio de Janeiro is evaluated using the Weather Research and Forecast Data Assimilation system. Synthetic data of temperature, relative humidity and wind are generated in the locations of airport sensors by applying a white-noise perturbation in the forecast data. Results show a positive overall impact of the assimilation process with the removal of part of the noise in the observation data but keeping the effect of local conditions in the later timesteps of the simulation. In addition, with the assimilation process there is a global reduction of the error between the analysis data and the observation data. In the future, a neural network will be trained to emulate the data assimilation process to speed-up the assimilation process in the WRF model.

Parametric Study of Air Infiltration in Residential Buildings—The Effect of Local Conditions on Energy Demand

Airtightness is nowadays one of the physical parameters which determine overall building energy performance. In a wide range of states, the upper limit for air change rate at a Pa (na), air permeability rate at a Pa (qa), or specific leakage rate at a Pa (wa) is determined by the formal regulations. It should be highlighted that airtightness requirements are mainly the same around the world, disregarding any site and climatic conditions. The main goal of the presented work was to reveal the effect of individual location and surrounding infiltration rate and heat demand. The analyses were done using numerical techniques and computational models of the three buildings developed and calibrated based on the blower door test results. The compared buildings characterize by a similar geometry but differ in the air change rate at 50 Pa (n50). Analyses done for different locations and levels of sheltering by surrounding elements allow the determination of the real effect of local conditions. The obtained differences in energy demand between two locations from the same climatic zone were from 70% to 90%, depending on the airtightness of the buildings. Considering different sheltered conditions, the differences for the same location can be even 200%. The obtained results allowed for the formulation of the general conclusion that building location and level of exposure could be considered in future airtightness regulations.

Sex-specific effects of reproductive season on bobcat space use, movement, and resource selection in the Appalachian Mountains of Virginia.

Across taxa, sex-specific demands vary temporally in accordance with reproductive investments. In solitary carnivores, females must provision and protect young independently while meeting increased energetic demands. Males seek to monopolize access to females by maintaining large territories and defending them from other males. For many species, it is poorly understood how these demands relate to broad-scale animal movements. To investigate predictions surrounding the reproductive strategies of solitary carnivores and effects of local conditions on bobcat (Lynx rufus) spatial ecology, we examined the effects of sex and reproductive season on home range size, movement rate, and resource selection of bobcats in the central Appalachian Mountains. Male seasonal home ranges were approximately 3 times larger than those of females (33.9 ± 2.6 vs. 12.1 ± 2.4 km2, x±SE), and male movement rates were 1.4 times greater than females (212.6 ± 3.6 vs. 155 ± 8.2 m/hr), likely reflecting male efforts to maximize access to females. Both sexes appear to maintain relatively stable seasonal home ranges despite temporally varying reproductive investments, instead adjusting movements within home ranges. Males increased movements during the dispersal period, potentially reflecting increased territoriality prior to breeding. Females increased movements during the kitten-rearing period, when foraging more intensively, and frequently returning to den sites. Both sexes selected home ranges at higher elevations. However, females selected deciduous forest and avoided fields, whereas males selected fields and avoided deciduous forest, perhaps explained by male pressure to access multiple females across several mountain ridges and higher risk tolerance. Seasonal changes in home range selection likely reflect changes in home range shape. Increased female avoidance of fields during kitten rearing may indicate female avoidance of presumably resource rich, yet risky, fields at the time when kittens are most vulnerable. Our results indicate that while reproductive chronology influences the spatial ecology of solitary carnivores, effects may be constrained by territoriality.

Effects of local conditions on the multi-variable and multi-objective energy optimization of residential buildings using genetic algorithms

The energy requalification of existing buildings entails the fulfillment of different, often conflicting, criteria, such as the reduction of the specific annual energy demand, the containment of the construction costs, the decrease in the annual energy operating cost and the reduction of climate-change gas emissions. Therefore, optimization methods based on the application of computational algorithms are essential to determine solutions that meet multi-objective criteria and so highly optimized to be on the Pareto frontier. In this work, a procedure for the optimization of existing buildings using genetic algorithms is presented. Building energy simulations conducted in the dynamic regime using EnergyPlus are coupled with an Active Archive Non-dominated Sorting Genetic Algorithm (aNSGA-II type). Using a residential building as a benchmark, this procedure is employed to evaluate the best retrofitting interventions for 19 European cities with different climates. The criteria taken into account in the optimization procedure are: the reduction in the annual specific energy demand, the decrease in the construction and installation costs, the reduction in the annual energy operating costs and the reduction in the greenhouse gas emissions. The results show the most advantageous energy retrofitting interventions fulfilling the criteria for the different geographical sites.

Effect of Radiation Intensity, Water Temperature and Support-Base Materials on the Inactivation Efficiency of Solar Water Disinfection (SODIS)

Solar water disinfection (SODIS) harnesses energy from the sun to kill pathogenic microorganism in drinking water, thus making it safe for consumption. The effects of local conditions and materials on the efficiency of SODIS were investigated in this study for a period of five months. Waste polyethylene terephthalate (PET) bottles with varying optical properties were used as SODIS reactors. Water samples from deep well, shallow well, rainfall and spring were used for the study. SODIS reactors were exposed to sunlight for a period of 8 h under varying conditions of temperature and solar radiation. The study revealed that solar radiation intensity of 500–650 W/m2 and water temperature of 45–55 °C, were effective in destroying pathogens. Analysis of variance (ANOVA) confirmed statistically significant difference (p < 0.000) in water temperature of the reactors and support base materials used. However, this did not translate to significant difference in microbial population after 8 h of exposure to sunlight. Over 3 Log reduction in faecal coliform was recorded at a temperature of 55.5 °C within 3 h of exposure. At temperatures below 45 °C, 3 log inactivation of bacteria was not attained even after 8 h of exposure to sunlight. Hence, SODIS can be employed to address the immediate water quality needs of the most disadvantaged communities of Nigeria.

In Situ High-Temperature EBSD and 3D Phase Field Studies of the Austenite-Ferrite Transformation in a Medium Mn Steel.

In this research, in situ high-temperature electron backscattered diffraction (EBSD) mapping is applied to record and analyze the migration of the α/γ interfaces during cyclic austenite-ferrite phase transformations in a medium manganese steel. The experimental study is supplemented with related 3D phase field (PF) simulations to better understand the 2D EBSD observations in the context of the 3D transformation events taking place below the surface. The in situ EBSD observations and PF simulations show an overall transformation behavior qualitatively similar to that measured in dilatometry. The behavior and kinetics of individual austenite-ferrite interfaces during the transformation is found to have a wide scatter around the average interface behavior deduced on the basis of the dilatometric measurements. The trajectories of selected characteristic interfaces are analyzed in detail and yield insight into the effect of local conditions in the vicinity of interfaces on their motion, as well as the misguiding effects of 2D observations of processes taking place in 3D.

Do artificial structures affect the feed of Patella caerulea limpets?

Do artificial structures affect the feed of Patella caerulea limpets?

Quantifying life cycle inventories of agricultural field operations by considering different operational parameters

The ability to estimate fuel and lubricant consumption as well as depreciated weight of agricultural machinery used for field operations is very useful for energy and environmental analyses. In this study, life cycle inventory data of agricultural field operations were established by considering different parameters of such operations. Agricultural operations considered in this study include tillage, cultivation, planting, harvesting and post-harvest operations. For these operations, the fuel and lubricant consumption as well as depreciated weight of tractors, combine harvesters and agricultural implements was estimated by considering different operational parameters such as tractor power, field condition, depth of operation, soil condition, tractor type, operational capacity of machine, width of operation and speed. Technical standards were used to estimate different types of power required for most agricultural operations (drawbar power, rotary power and motion power). The standards were then used to evaluate the variability of the fuel and lubricant consumption as well as depreciated weight of the implements by varying the aforementioned parameters. The results were compared to those that can be calculated with other approaches for life cycle inventory analysis of agricultural operations. Such comparison indicates that by using different parameters, representing the diverse local conditions of different field operations, a great variability of the results is obtained. For instance, diesel fuel consumption of tillage operations ranges from 12.6 to 76.0 L ha−1, with an average of 34.15 L ha−1 and standard deviation of 11.7 L ha−1. Such representativeness of the different conditions of each field operation cannot be modelled with other tools or via the use of standard LCI datasheets. The final result of this study is a novel approach for the life cycle inventory analysis of agricultural operations, in terms of fuel and lubricant consumption and of depreciated weight of the machines, which are estimated by simply selecting the operational parameters which best represent the effect of local conditions.

Morphometric relationships and seasonal variation in size, weight, and a condition index of post-settlement stages of the Caribbean spiny lobster.

Spiny lobsters have a protracted pelagic, oceanic larval phase. The final larval stage metamorphoses into a non-feeding postlarva (puerulus) that actively swims towards the coast to settle in shallow habitats and does not resume feeding until after the molt into the first-stage juvenile. Therefore, the body dimensions and nutritional condition of both settled pueruli and first juveniles are likely to vary over time, potentially playing a crucial role in the recruitment to the benthic population. We compared carapace length (CL), height (CH), and width (CW); total length (TL), and body weight (W) between pueruli and first juveniles of the Caribbean spiny lobster, Panulirus argus, as well as morphometric relationships between both developmental stages. Except for CL, all other dimensions were larger in first juveniles, but more markedly CH and W. The slopes of the CH vs CL, CW vs CL, and W vs CL regressions differed significantly between stages, and all log-transformed relationships showed isometry in both stages, except for the CH vs CL relationship, which showed positive allometry. These results reflect a morphological change from the flatter, more streamlined body of the puerulus, to the heavier, more cylindrical body of the juvenile. We also analyzed seasonal variations in CL, W, the W/CL index (a morphometric condition index), and a modified W/CL index (i.e. after controlling for a significant effect of CL) of both stages using individuals monthly collected over 12 consecutive seasons (Autumn 2010–Summer 2013). In both stages, all three variables exhibited significant seasonal variation. For pueruli, the modified W/CL index differed from average in only two seasons, winter 2011 (higher) and summer 2013 (lower), but showed great within-season variation (larger coefficients of variation, CV), potentially reflecting variability in nutritional condition of larvae prior to metamorphosis and in the distances swum by individual pueruli to the settlement habitats. For first juveniles, the modified W/CL index was higher than average in winter and spring 2011, and lower in autumn 2011 and winter 2012, but showed less within season variation (smaller CVs), suggesting a combination of carry-over effects of puerulus condition and effects of local conditions (e.g., food availability and predation risk). These findings warrant further investigation into factors potentially decoupling settlement from recruitment processes.

Cyanobacterial populations in biological soil crusts of the northwest Negev Desert, Israel-effects of local conditions and disturbance.

Biological soil crusts (BSCs) fulfil numerous ecological functions in arid and semiarid areas. Cyanobacteria are important BSC organisms, which are responsible for carbon fixation, N2 fixation and binding of soil via extracellular polysaccharides. The cyanobacterial populations were characterised in different sampling plots established in three experimental stations along a rainfall gradient within NW Negev Desert, Israel. Cyanobacterial crust thickness and osmolyte accumulation therein decreased in plots with lower moisture. The cyanobacterial population structure also changed in different plots. We observed an increase of subsection III cyanobacteria such as Microcoleus spp. and Leptolyngbya spp. and a decreasing proportion of strains belonging to subsections I and IV in drier areas on the rainfall gradient. This population shift was also observed in the sampling plots, which were situated at various relief positions within the sand dune experimental sites. We also characterised the cyanobacterial populations within mechanically disturbed plots. After 4 years, they reached between 80% and 50% of the control populations in the northernmost and southern stations, respectively. Our results suggest that the cyanobacterial population is sensitive not only to macroscale factors but may also be subject to local climate variations and that 4 years was insufficient for complete recovery of the cyanobacterial population.

Education Reform in China: Toward Classroom Communities

ABSTRACTFocusing on China’s current education reform, this article critically discusses how contextual factors, specifically sociocultural factors and resources, assist and constrain Chinese educators in their attempt to develop dynamic and inviting classroom communities. Three main findings are highlighted in this article, the first being that the creation of classroom communities is perceived by Chinese educators to be beneficial to the students. Secondly, Chinese educators judiciously rely on existing professional learning communities to experiment with and launch classroom communities. The third finding foregrounds two key challenges faced by educators. The first challenge is the difficulty with fostering classroom communities in the poorer parts of China where schools perennially struggle with huge class size and inadequate educational support. The second key challenge is a predominantly exam-centric culture that inhibits the flourishing of classroom communities for effective teaching and learning. The experience in China illustrates the moderating effects of local conditions in shaping the evolving concept and practice of classroom community.

Effect of local conditions and machinery characteristics on the environmental impacts of primary soil tillage

The interest in environmental assessments about agricultural processes is high and asks for tools for accurate impact evaluations. The methodology commonly used in these studies is the Life Cycle Assessment (LCA), of which the inventory phase (Life Cycle Inventory – LCI) is the essential and most complex step to fulfil, for agricultural productions in particular. The reason is that taking into account local variables such as soil texture and mechanical operative solutions for the agro-mechanical operations is difficult.The aim of this study was to perform a case study to quantify the environmental impacts through LCA of alternative ploughing solutions and to quantify the differences that occur when an analysis is fulfilled with inventories completed with two different tools. First, when a database furnishes average data (Ecoinvent) and, secondly, when the inventory is completed with a tool that considers local variables. In particular, the used new tool is ENVIAM (ENVironmental Inventory of Agricultural Machinery operations), which was developed to take into account local variables. Finally, a subsequent goal was to quantify the environmental impacts through LCA of alternative ploughing solutions. Using ENVIAM, mouldboard ploughs were compared with slatted ploughs and variables such as the number of ploughshares, the field shape ratio (i.e. the ratio of field length and width considering regular quadrangles) and soil texture differed. Fuel consumption and exhaust gases emissions were calculated as function of working time, engine load and European Standard Emissive Stage. The functional unit was “1 ha tilled in a primary soil tillage operation appropriately and completely carried out” and the International Reference Life Cycle Data System (ILCD) characterization method was used for the impact assessment. The most common implement present in Northern Italy, the 3 ploughshares mouldboard plough, was considered as baseline scenario. When working on medium texture soils, discrepancies with Ecoinvent were not negligible (less than 9% for Climate Change and Ozone Depletion). However, they resulted even 2–3 times higher for Particulate Matter and Mineral and Fossil Resources Depletion. Instead, when soil texture differed, dissimilarities were considerably higher. For example, Climate Change impact category ranged between −46.2% and +108.1% of the identified baseline case (with sandy and clay soils, respectively).

Contrasting factors drive within-lake bacterial community composition and functional traits in a large shallow subtropical lake

Lakes are considered as “islands” for assessing microbial biogeography, but bacterial community composition (BCC) and function may vary significantly within lakes, with the roles of scale and connectivity still unclear. This study investigated the spatial and temporal heterogeneity of the BCC (automated ribosomal intergenic spacer analysis) and functional traits (FT, carbon-source utilization), and the contribution of: (i) environmental variables, (ii) phytoplankton, (iii) season, and (iv) space, through variance partitioning in the large and well-mixed Lake Mangueira. The BCC and FT differed in time and space, with BCC being explained by environmental variables and phytoplankton, whereas FT was explained only by space. The smallest scale of variability detected by the BCC and FT (~49 km) was larger than scales found in the other studies, suggesting an effect of lake size (fetch and connectivity). Our results indicate that barriers to bacterial dispersal due to long distances are overcome by high connectivity, reinforcing the role of species sorting for BCC. FT were probably driven by gene dispersal and/or the effects of local conditions on migrant bacterial taxa and resuspended bacteria. Our results highlight the role of within-lake heterogeneity for ecosystem functioning and the implications for the appropriate scale to use in sampling bacterial communities.

How Durable are Social Norms? Immigrant Trust and Generosity in 132 Countries

This paper estimates the global prevalence of social trust and generosity among immigrants. We combine individual and national level data from immigrants and nativeborn respondents in more than 130 countries, using seven waves of the Gallup World Poll (2005–2012). We find that migrants tend to make social trust assessments that mainly reflect conditions in the country where they now live, but they also reveal a significant influence from their countries of origin. The latter effect is one-third as important as the effect of local conditions. We also find that the altruistic behavior of migrants, as measured by the frequency of their donations in their new countries, is strongly determined by social norms in their new countries, while also retaining some effect of the levels of generosity found in their birth countries. To show that the durability of social norms is not simply due to a failure to recognize new circumstances, we demonstrate that there are no footprint effects for immigrants’ confidence in political institutions. Taken together, these findings support the notion that social norms are deeply rooted in long-standing cultures, yet are nonetheless subject to adaptation when there are major changes in the surrounding circumstances and environment.

Switching sides: The struggle between national identity and globalized pedagogy in the development of an early literacy programme in Cambodia

Abstract In 2006 a bi-lateral donor working with the Ministry of Education, Youth and Sport (MoEYS) in Cambodia identified the need for improving the quality of literacy. The bilateral donor outsourced the contract to a team of British consultants to design and lead an early literacy project working alongside Khmer national consultants. This article begins by discussing and analysing how globalized perceptions of teaching, learning and national identity were enshrined in the development of training and classroom materials for both teacher and pupils. It uses the example of the place of phonics in the teaching of reading to explore the contradictions in practice between donor and low income countries. By examining the perceptions and assumptions made by all parties and analysing the discourse that took place in the development process it is possible to identify how national education and perceptions of identity and citizenship come into conflict with what was identified as a ‘global pedagogy’. As more agencies become involved and agendas change, the conflict between issues of national identity, citizenship and global pedagogy become increasingly blurred leaving the authors the task of unpacking the relative importance of these concepts on the impact of the project. We conclude that in educational project design there is a need to strike a balance between the influences exerted through international practice and priorities against the effects of local conditions, culture and context.

Procedures for Multiaxial Creep-Fatigue Verifications of Nuclear Components

Nuclear high heat flux components (HHFCs) experience large thermal gradients and high heat flux variations, which induce severe thermal cyclic loadings. The most critical design issue for these components is their endurance strength under the required number of thermal cycles.The aim of this work is to provide procedures to perform the multiaxial creep-fatigue life assessment of HHFCs. Since the existing design codes present limitations due to simplifying assumptions concerning procedures for the multiaxial fatigue verification considering interactive effects of creep-fatigue and local stress and temperature conditions, better accurate verification methods and rules are developed starting from the available scientific literature and experimental data. The new verification methods identify the shape of the most damaging hysteresis loop considering plasticity and creep strains in both tensile and compressive conditions.The developed procedures are used to post-process the thermomechanical results of finite element (FE) analyses. They foresee the calculation of the creep-fatigue damage in each node and for each cyclic loading of the analyzed FE model by using the fatigue curve corresponding to the shape of the local hysteresis loop. Furthermore, the most fatigued elements are bounded and the causes of damage are identified to improve the local design. The fatigue damage is evaluated considering the effects of local conditions: temperature, multiaxial stress-strain state, strain intensity range, effect of local mean stresses, material shakedown, accumulated damage for multiple cyclic loads, combined effect of creep-fatigue, hold periods, and neutron flux.The developed procedures are successfully verified by comparing the results with experimental data for different levels of mean stress.This paper presents a description of the procedures and design rules focusing on the innovative aspects. The new procedures have been developed in the framework of the activities for the design, manufacturing, and procurement of the ITER neutral beam injector, and they are applied for creep-fatigue verifications of the in-vessel HHFCs.

The Effect of Local Conditions on Tree-Ring Growth Dynamics of Gmelin Larch in the North of Central Siberia

The Effect of Local Conditions on Tree-Ring Growth Dynamics of Gmelin Larch in the North of Central Siberia

A Simple Formula for Complementing FE Analyses in the Estimation of the Effects of Local Conditions in Circular Cylindrical Shells

A Simple Formula for Complementing FE Analyses in the Estimation of the Effects of Local Conditions in Circular Cylindrical Shells

Genetic and morphological patterns show variation in frequency of hybrids between Ipomopsis (Polemoniaceae) zones of sympatry

Variation in rates of hybridization among zones of sympatry between a pair of species provides a useful window into the effect of local conditions on the evolution of reproductive isolation. We employed floral morphological traits and neutral genetic markers to quantify the frequency of individuals intermediate to the two parental species in two zones of sympatry between Ipomopsis aggregata and I. tenuituba, using clustering methods that make no a priori assumptions about population structure. The sites differed not only in the frequency of intermediate individuals, but also in climate, pollinator abundance and behavior and spatial structure of plant populations. Both floral traits, which are likely to be under natural selection and molecular markers, which are quasi-neutral, indicated more population structure at one site than the other, the pattern being more pronounced for floral morphology. One likely explanation for this difference between sites is that local ecological conditions, particularly pollinator choice of flowers, have promoted different rates of hybridization between these species. Hence, the evolution of reproductive isolation might depend in part on local conditions, and thus differ among populations of the same pair of species.