Seasonal Load Research Articles

Challenges and perspectives for integral bridges in the UK: PLEXUS small-scale experiments

This study focuses on the investigation of the factors that have limited, so far, the development of a consistent design and assessment approach for integral bridges (IBs). This paper presents a review of previous research and current design practices for IBs, followed by an overview of monitoring studies in the laboratory and in the field. As part of the UK Collaboratorium for Research on Infrastructure and Cities–Priming Laboratory EXperiments on Infrastructure and Urban Systems experimental campaign, a small-scale 1 g physical experiment is described. The test aimed to simulate the soil–structure interaction arising from seasonal expansion and contraction of the bridge deck and assess the performance of different monitoring techniques. Pressure cells were used to measure the lateral stresses behind the abutment wall, particle image velocimetry was employed to monitor the soil behaviour behind the abutment and linear variable differential transformers were used to monitor the backfill surface movements. By combining the data from these instruments, a preliminary assessment of the soil–structure interaction behaviour of the idealised integral abutment under seasonal thermal loading has been obtained. These monitoring methods and the associated understanding of IB behaviour gained from the tests provide definitive evidence for the development of monitoring systems for larger-scale physical tests and field monitoring systems for IBs.

Novel predictors related to hysteresis and baseflow improve predictions of watershed nutrient loads: An example from Ontario's lower Great Lakes basin

Eutrophication has re-emerged in the lower Great Lakes basin resulting in critical water quality issues. Models that accurately predict nutrient loading from streams are needed to inform appropriate nutrient management decisions. Generalized additive models (GAMs) that use surrogate data from sensors to predict nutrient loads offer an alternative to commonly applied linear regression and may better handle relationship non-linearities and skewed water quality data. Five years (2015–2020) of water quantity and quality data from 11 agricultural watersheds in southern Ontario were used to develop GAMs to predict total phosphorus (TP) and nitrate (NO3−) loads. This study aimed to 1) use GAMs to predict nutrient loads using both common and novel predictors and 2) quantify and examine the variability in seasonal and annual nutrient loads. Along with routine surrogate model predictors (i.e., flow, turbidity, and seasonality), the addition of the baseflow proportion and the hydrograph position of flow observations improved model performance. Conversely, including the antecedent precipitation index minimally affected model performance, regardless of constituent. Seasonal and annual patterns in TP and NO3− load predictions mirrored that of the hydrologic regime. This study showed that parsimonious GAMs featuring novel model predictors can be used to predict nutrient loads while accounting for the partitioning of surface and subsurface flow paths and hysteresis between streamflow and water quality parameters that are frequently observed in a wide range of environments.

Analysis and Design Methodology of a Novel Integration Topology of Storageless Off-Grid PV Systems

In this manuscript, a novel topology is proposed to integrate on-grid and off-grid PV systems supplying the same load premises. The load side is investigated and analyzed, and critical and non-critical loads are separated in terms of power supply. Critical and seasonal loads usually place stress on the grid’s point of common coupling (PCC). In the proposed topology, they are supplied by a novel topology for an off-grid solar pump PV system that lacks energy storage integration. The lack of energy storage batteries requires a novel design and sizing scheme for the off-grid PV system, and a methodology is proposed in this manuscript. The on-grid PV system is conventionally designed and coupled with the storage-less off-grid PV system to maintain load supply. The proposed methodology minimizes the ratings of the PCC and hence relieves stress on congested grids with renewable energy penetration, especially in condensed urban areas. The proposed structure enables the operation of microgrids with high penetration levels of renewable energy resources and minimizes dependance on storage batteries for off-grid systems. A case study is presented and thoroughly analyzed with the proposed methodology. The outcomes of the design process are evaluated economically and were found to be feasible, as is detailed and supported with simulation results.

Seasonal Training Load Monitoring Among Elite Level Soccer Players: Perceived Exertion and Creatine Kinase Variations Between Microcycles.

The primary aim of the investigation was to determine the daily load variations between the microcycles of an entire season of an elite group of professional soccer players. The second aim of this study was to determine the relationships between Foster’s rating of perceived exertion (RPE), the Hooper index (HI) and CK levels over the weekly microcycles of the season. Thirty-five male professional soccer players participated in this study (3 goalkeepers, 6 wide defenders, 4 central defenders, 9 midfielders, 8 wide midfielders and 4 forwards) (25.7 ± 5.0 years, 182.3 ± 6.4 cm; 79.1 ± 7.0 kg). Significant differences between months in the variables of HI (p = 0.001; ES = 0.052), minT (p = 0.001; ES = 0.066), IL (p = 0.001; ES = 0.052, minimum effect) and CK (p = 0.002; ES = 0.031) were found. Comparison of the HI (p = 0.044; ES = 0.002), minT (p = 0.001; ES = 0.045), and IL (p = 0.001; ES = 0.045) revealed significant differences between microcycles. No significant differences were found in CK (p = 0.710; ES = 0.001) across the period. A significantly higher internal training load and fatigue perception in microcycles with only one official match was found. The greater load occurred 3 to 4 days before the game. In addition, it can be concluded that the first quarter of the season seemed to induce a greater physical demand on elite professional players.

Upper troposphere dust belt formation processes vary seasonally and spatially in the Northern Hemisphere

Dust aerosols impact global energy balance substantially by acting as efficient ice nuclei to alter cold cloud properties. However, the estimate of dust indirect effect remains uncertain due to simulating dust distributions poorly and lacking reliable dust observations, especially in the upper-troposphere. Here, we characterize and understand upper-troposphere dust sources and transport with an improved dust dataset derived from A-train satellite lidar and radar measurements and an air parcel trajectory model. The distinct upper-troposphere dust belt over the northern hemisphere has seasonally varying base and top heights of 3.65 ± 2.84 and 8.35 ± 1.50 km above mean sea level and its column loading is strongest during spring (March-April-May). The out-of-phase annual cycles of mid-level dust concentration and westerly wind over source regions control the seasonal upper-tropospheric dust loading variations. African deserts contribute the most (46.3%) to the upper-troposphere dust belt in spring and the synoptic trough is the leading (49%) dust lifting mechanism.

Long term influence of groundwater preservation policy on stubble burning and air pollution over North-West India

Stubble burning (SB) has been a major source of seasonal aerosol loading and pollution over northern India. The aftereffects of groundwater preservation act i.e., post 2010 era (2011–2020) has seen delay in crop harvesting thereby shifting the peak SB to May (Wheat SB) and to November (Paddy SB) by 8–10 and 10–12 days compared to pre-2010. Groundwater storage depletion rate of 29.2 mm yr−1 was observed over the region. Post 2010 era shows an increase of 1.4% in wheat SB and 21% in Paddy SB fires over Punjab and Haryana with 70% of PM2.5 air mass clusters (high probability > 0.8) advecting to the downwind regions leading to 23–26% increase in PM2.5 and 4–6% in aerosol loading over National Capital Region (NCR). Although the objective of water conservation policy was supposed to preserve the groundwater by delaying the paddy transplantation and sowing, on the contrary the implementation of this policy has seen groundwater storage after 2013 depleting at a rate of 29.2 mmyr−1 over these regions. Post policy implementation has led to shift and shrinking of harvest window with increased occurrences in SB fires which also increase associated particulate matter pollution over North India.

Energy management and control system for microgrid based wind-PV-battery using multi-agent systems

Energy generation is currently evolving into a smart distribution system that incorporates several green energy resources at a distributed level, ensuring that clean energy is generated without releasing harmful gases, that operational procedures are consistent, and that energy management and supervision arrangements are improved. This paper proposes a multi-agent system-based microgrid energy management and proper control in distributed systems. For the complexity of energy management in distributed systems, a multi-agent system-based decentralized control architecture was developed. The proposed technique is based on several smart agents, each agent is based on the microgrid data for energy management and frequency control. The proposed energy management system based on the multi-agent system was tested by simulation under renewable resource fluctuations and seasonal load demand. The simulation results show that the proposed energy management system proved to be more resilient and high-performance controls than conventional centralized energy control systems.

Seasonal watershed-scale influences on nitrogen concentrations across the Upper Mississippi River basin

ABSTRACT In the Upper Mississippi River basin, after spring fertilizer application, total nitrogen concentration [TN] in streams drops by ~73% from June to September, consistent with effects of seasonal nutrient loading. We hypothesized that this seasonal variability might be affected by land cover (e.g. wetland, cultivated area extent). To test this hypothesis, we adopted a linear mixed-effects modeling approach including periodic functions. However, inclusion of wetland area was not indicated, suggesting that increased model complexity associated with inclusion of contemporary wetland extent was unjustified. While consideration of cultivated extent in relation to mean annual [TN] was shown to improve performance, no evidence was observed that cultivated extent could enhance explanation of intra-annual [TN]. Improved understanding of cause and effect will require improved spatiotemporal data on nitrogen sources and additional critical field experimentation, which in turn is expected to set the stage for advancement in physically- or process-based modeling of nutrient concentrations.

A Novel Analytical Solution of Borehole Heat Exchangers with Seasonal Heat Load

A Novel Analytical Solution of Borehole Heat Exchangers with Seasonal Heat Load

Sanitary-microbiological characteristics of the coastal zone of Lake Baikal during the seasonal change in the lake level in 2022

Abstract. The paper presents the results of the study of water quality by sanitary-microbiological characteristics in the littoral zone of Lake Baikal and its tributaries in July and September 2022. It was found that the number of studied bacteria does not correlate with the level of the lake, but is caused by the seasonal anthropogenic load. Exceedances of the standards in the summer period were detected in the area of Kultuk settlement, Baikalsk town, Listvyanka settlement, Bolshie Koty settlement, in the bays of Maloe More, Chivyrkuisky and Barguzinsky bays, and in the rivers Medlyanka, Pokhabikha, Pereyomnaya, Kuchelga, Turka, Barguzin, and in the hydrotherm of Zmeinaya Bay. In autumn, the quality of the surface water did not meet the norm near the settlement of Bolshoe Goloustnoe, in Aya Bay, in the bays Zagli and Chivyrkuisky, and in the mouths of the rivers Medlyanka, Pokhabikha, Slyudyanka, and Mysovka. In the tributaries where wastewater is discharged (Medlyanka, Pokhabikha and Mysovka), the number of sanitary-indicatory bacteria remains high both in the summer and autumn seasons.

Ways to reduce carbon dioxide emissions from arable machinery and tractor units

The article is devoted to the search for ways to reduce carbon dioxide emissions in the technological operation of plowing. Ways to reduce CO2 emissions were determined on the basis of computational experiments conducted using a mathematical model of an arable unit compiled according to the efficiency criterion - the minimum integral emission of carbon dioxide. Integral CO2 emission, in addition to direct and indirect CO2 emissions over the life cycle of the arable unit, includes CO2, which could be absorbed from the atmosphere by the crop lost due to the influence of the parameters of the unit. The influence of the parameters of the tractor and the unit on the emission of carbon dioxide during its manufacture, technical and production operation is analyzed. Computational experiments were conducted to identify the influence of some external factors (field area, seasonal load volume, etc.) on the efficiency of the arable unit.

Study of the influence of various factors on the emission of carbon dioxide by the aggregate during direct sowing of grain crops

The article deals with issues related to the reduction of carbon dioxide emissions into the atmosphere during the operation of sowing machine and tractor units. To identify ways to reduce CO2 emissions, computational experiments were conducted using a mathematical model of sowing units compiled according to the efficiency indicator. This is the integral emission of carbon dioxide as the sum of CO2 in the manufacture, maintenance, repair, control of the unit, when burning fuel and the amount of CO2 not absorbed from the atmosphere during the formation of the grain crop due to its losses from improperly selected equipment and its parameters. The influence of a number of factors on the integral emission of CO2 is investigated. These are the area of the treated area or field, the specific resistance of the planter, the volume of seasonal load on the unit, the annual load of the tractor in hours, the physical and mechanical properties of the soil, the pressure in the tires of the wheel propulsion engines, etc. Effective values of factors for reducing the emission of carbon dioxide by the sowing unit are revealed. The use of the totality of all the recommendations received will reduce the emission of carbon dioxide into the atmosphere by the aggregate during the technological operation of direct sowing of grain crops by 600-650 kg/ha.

Time-Series Quasi-Dynamic Load Flow Analysis with Seasonal Load Variation to Resolve Energy Nexus for a Practical Distribution Network in Puducherry Smart Grid System Incorporating Harmonic Analysis and Mitigation

Time-Series Quasi-Dynamic Load Flow Analysis with Seasonal Load Variation to Resolve Energy Nexus for a Practical Distribution Network in Puducherry Smart Grid System Incorporating Harmonic Analysis and Mitigation

Eruption cycles of Mount Etna triggered by seasonal climatic rainfall

The ability to mitigate and predict volcanic risk is a long-standing question in the Geosciences’ community, while the extent of volcanic activity may be regulated by a predictable and periodic external excitation induced by seasonal rainfall, hydrological loading, or Moon-Sun gravitational force. Moreover, the complex stress-triggering, hydro-mechanical coupling in response to seasonal rainfall, and associated feedback mechanism with deep magmatic process remains enigmatic and indeed deserves more attention in view of recent climate change scenario. In this letter, a compelling scenario of seasonal rainfall-triggered eruption cycles of Mount Etna (Italy) is found and presented on the eastern coast of Sicily which continuously erupting since last 200 kyr. Results show that the seasonal rainfall significantly weakened the Mount Etna edifice and initiated mechanical tensile failure in the complex magmatic plumbing system and adjacent flank surface by changing the pore pressure build-up, probably promoting dyke intrusion and eventual triggering of eruptive cycle. Further, the possibility of seasonal hydrological loading on the Mount Etna volcano and adjacent flank region, hydrological load-induced sliding along the impermeable outer ‘shell’ of the flank are discussed, and the effect of tidal stress perturbations on the eruptions cycle cannot be ruled out completely.

The impacts of electric vehicles and heat pumps load profiles on low voltage distribution networks in Great Britain by 2050

The impacts of uptake and electricity load profiles of Electric Vehicles (EVs) and Heat Pumps (HPs) on the low voltage (LV) distribution networks were analyzed. The United Kingdom (UK) has a legally mandated policy concerning reduction of greenhouse gasses (GHGs) emissions. Therefore, the integration of low carbon technologies (LCTs) especially EVs and HPs at the LV networks is expected to increase in the drive to reducing the GHGs emissions. Future uptake scenarios, adapted from the National Grid studies, of EVs and HPs were developed for a real and typical urban LV distribution network in Great Britain (GB). Gridlab-D, an agent-based power system simulation software, was used to model the LV distribution network. The model was run for four different scenarios considering seasonal load profiles and projected EVs and HPs uptakes for each of the year 2020, 2030, 2040 and 2050 respectively. The results were analyzed in terms of transformer loading, voltage profiles of the feeders, and the ampacity loading of the cables for the different scenarios of the years.

Analysis of Unbalanced Radial Distribution System with SVR and Impact of Phase Shifter Angle considering Time Varying Loads

ABSTRACT Distribution network experiences unbalancing due to random switching of loads, low voltage profile, high R/X ratio, and unequal loading in the different phases, which inturn causes more losses compared to transmission line. The voltage profiles, active, and reactive power in each phase are distinct due to unbalancing. In the present work, the authors analyzed unbalanced distribution network in presence of Series Voltage Regulator (SVR) considering the reduction in the losses and improvement in the voltage profile. The main highlights of the paper are: (i) placement and analysis of unbalance radial network with SVR at various phase angles; (ii) reduction in active, reactive power loss of the network and improvement in voltage profile; (iii) saving in cost of energy loss at different phase angle of SVR; and (iv) impact analysis of seasonal time varying load model. The placement of SVR at candidate node by considering real, reactive power loss reduction, and percentage rate of under voltage mitigated problem. Before and after SVR placements, the forward and backward sweep algorithm is used for the load flow calculation for analysis. The analysis is carried out on IEEE 25-bus radial distribution network with SVR phase shifter considering time varying seasonal load variations.

Quantifying Training and Game Demands of a National Basketball Association Season.

Purpose: There are currently no data describing combined practice and game load demands throughout a National Basketball Association (NBA) season. The primary objective of this study was to integrate external load data garnered from all on-court activity throughout an NBA season, according to different activity and player characteristics.Methods: Data from 14 professional male basketball players (mean ± SD; age, 27.3 ± 4.8 years; height, 201.0 ± 7.2 cm; body mass, 104.9 ± 10.6 kg) playing for the same club during the 2017–2018 NBA season were retrospectively analyzed. Game and training data were integrated to create a consolidated external load measure, which was termed integrated load. Players were categorized by years of NBA experience (1-2y, 3-5y, 6-9y, and 10 + y), position (frontcourt and backcourt), and playing rotation status (starter, rotation, and bench).Results: Total weekly duration was significantly different (p < 0.001) between years of NBA playing experience, with duration highest in 3–5 year players, compared with 6–9 (d = 0.46) and 10+ (d = 0.78) year players. Starters experienced the highest integrated load, compared with bench (d = 0.77) players. There were no significant differences in integrated load or duration between positions.Conclusion: This is the first study to describe the seasonal training loads of NBA players for an entire season and shows that a most training load is accumulated in non-game activities. This study highlights the need for integrated and unobtrusive training load monitoring, with engagement of all stakeholders to develop well-informed individualized training prescription to optimize preparation of NBA players.

Annual Cost and Loss Minimization in a Radial Distribution Network by Capacitor Allocation Using PSO

Increasing power demand from passive distribution networks has led to deteriorated voltage profiles and increased line flows. This has increased the annual operations and installation costs due to unavoidable reinforcement equipment. This work proposes the reduction in annual costs by optimal placement of capacitors used to alleviate power loss in radial distribution networks (RDNs). The optimization objective function is formulated for the reduction in operation costs by (i) reducing the active and reactive power losses, and (ii) the cost and installation of capacitors, necessary to provide the reactive power support and maintain the voltage profile. Initially, the network buses are ranked according to two loss sensitivity indices (LSIs), i.e., active loss sensitivity with respect to node voltage (LSI1) and reactive power injection (LSI2). The sorted bus list is then fed to the particle swarm optimization (PSO) for solving the objective function. The efficacy of the proposed work is tested on different IEEE standard networks (34 and 85 nodes) for different use cases and load conditions. In use case 1, the values finalized by the algorithm are selected without considering their market availability, whereas in use case 2, market-available capacitor sizes close to the optimal solution are selected. Furthermore, the static and seasonal load profiles are considered. The results are compared with recent methods and have shown significant improvement in terms of annual cost, losses and line flows reduction, and voltage profile.

The influence of initial shaft resistance mobilisation in the response of seasonally, thermally-activated pile foundations in granular media

The thermal-activation of pile foundations for use within shallow geothermal energy systems has received much attention and the results from various studies have allowed the development of a broad understanding of the thermo-mechanical behaviour of thermally-activated (TA) pile foundations. One area that requires further attention is the clarification of the foundation response under seasonal cyclic thermal loading. This study systematically assesses the impact of balanced cyclic thermal loading in relation to the initial mechanical loading, for isolated floating piles and pile groups in a frictional soil medium. The pile thermal response was evaluated for differing levels of mobilisation of the shaft resistance with respect to the initial mechanical loading and for piles at varying spacing based on a unit cell approach. Isolated piles with high shaft mobilisation were found to develop significant irrecoverable settlement during thermal cycling however the maximum thermal stress was similar irrespective of the initial shaft mobilisation. These results are remarkably similar to those reported in small scale tests of TA piles in sand, confirming that the behaviour reported in these is likely to be due to the result of low shaft restraint, rather than thermally-induced loss of resistance on the pile–soil interface. On the other hand, piles in close proximity were found to behave quasi thermo-elastically at the same initial mechanical load, which is attributed to an alteration in mobilised pile resistance due to pile–soil–pile interference under the initial mechanical loading and, to a lesser extent, thermal activation of the ground between the piles both of which reduce the relative movement between the pile and the soil. This pile group thermal effect has major beneficial implications for the geotechnical and structural design of TA pile foundations.

Seasonal Seismicity in the Lake Biwa Region of Central Japan Moderately Modulated by Lake Water Storage Changes

AbstractSeasonal seismicity in Japan has been observed and attributed to variations induced by hydrological loading, as well as atmospheric and pore‐fluid pressure. We examine the seasonal variations of crustal (&lt;15 km depth) and low magnitude (M &lt; 4.5) earthquakes in central Japan near the Biwako‐Seigan Fault Zone (BSFZ), and analyze their correlation with the annual hydrological cycle of nearby Lake Biwa, the largest freshwater lake in Japan. The 2002–2018 lake water storage is estimated using water‐level gauge and satellite altimetry data. Regional surface mass loading from soil moisture and snow predicted by the Global Land Data Assimilation System is used to augment the lake mass variation. We compute the stress and stressing‐rate changes induced by the surface mass loading from lake storage, snow, and soil moisture at seismogenic depth (10 km) along the BSFZ using a finite element model incorporating a 3D Earth structure. The results show that seasonal surface mass loading generates 1–5 kPa peak‐to‐peak Coulomb stress change and 2.5–15 kPa/year stressing‐rate variations on the fault segments along the BSFZ. Two of the four fault segments present significant correlation between local seismicity rate and loading‐derived stress and/or stressing rate changes. Among the hydrological load components, lake water, snow, and soil moisture exhibit different annual phases, and the lake water storage dominates the total annual stress changes. Our analysis indicates that seasonal surface hydrological loads, especially lake water variations, modulate the seismicity rate along the BSFZ in central Japan.