Zonal Control Research Articles

Insights into the risk of COVID-19 infection in urban neighborhood and its environmental influence factors:A novel approach

Many studies have dealt with the relationship between the built environment and COVID-19 infection in isolation. However, the research approaches were often inadequate in accurately reflecting the risk of COVID-19 infection. Therefore, we aim to develop a novel approach to study the risk of COVID-19 infection and its Environmental Influence Factors (EIFs) at the neighborhood scale. We constructed a multi-agent model of the spatial environment of residential quarters, including models of behavior and COVID-19 infection dynamics, and established 24 experimental schemes based on the Prevention and Control Measures (PCMs) of zonal control, mask-wearing, and outing frequency to simulate and assess the infection risk. The results show that the areas of accessible wood, hard surfaces, and seating are high-risk sites for infection. Zonal control and mask-wearing are effective PCMs, and the EIFs we set all play significant roles in influencing infection risk. Our study provides insight into the effects of PCMs and EIFs related to COVID-19 infection and highlights that the novel approach not only reveals the levels of infection risk and its mechanisms but also detects the spatio-temporal characteristics of behaviors and infection. This novel approach, dealing with individuals, space, environment, behavior, PCMs, and COVID-19 infection dynamics in integration, overcomes the limitations of traditional methods that overlook the influences of the spatio-temporal dynamics of individual behaviors and their environmental factors. It offers theoretical support for designing healthy outdoor built environments and technical support for the PCMs of the epidemic.

Zonal control on Holocene precipitation in northwestern Madagascar based on a stalagmite from Anjohibe

The Malagasy Summer Monsoon is an important part of the larger Indian Ocean and tropical monsoon region. As the effects of global warming play out, changes to precipitation in Madagascar will have important ramifications for the Malagasy people. To help understand how precipitation responds to climate changes we present a long-term Holocene speleothem record from Anjohibe, part of the Andranoboka cave system in northwestern Madagascar. To date, it is the most complete Holocene record from this region and sheds light on the nature of millennial and centennial precipitation changes in this region. We find that over the Holocene, precipitation in northwestern Madagascar is actually in phase with the Northern Hemisphere Asian monsoon on multi-millennial scales, but that during some shorter centennial-scale events such as the 8.2 ka event, Anjohibe exhibits an antiphase precipitation signal to the Northern Hemisphere. The ultimate driver of precipitation changes across the Holocene does not appear to be the meridional migration of the monsoon. Instead, zonal sea surface temperature gradients in the Indian Ocean seem to play a primary role in precipitation changes in northwestern Madagascar.

Composite Spheroid-Laden Bilayer Hydrogel for Engineering Three-Dimensional Osteochondral Tissue.

A combination of hydrogels and stem cell spheroids has been used to engineer three-dimensional (3D) osteochondral tissue, but precise zonal control directing cell fate within the hydrogel remains a challenge. In this study, we developed a composite spheroid-laden bilayer hydrogel to imitate osteochondral tissue by spatially controlled differentiation of human adipose-derived stem cells. Meticulous optimization of the spheroid-size and mechanical strength of gelatin methacryloyl (GelMA) hydrogel enables the cells to homogeneously sprout within the hydrogel. Moreover, fibers immobilizing transforming growth factor beta-1 (TGF-β1) or bone morphogenetic protein-2 (BMP-2) were incorporated within the spheroids, which induced chondrogenic or osteogenic differentiation of cells in general media, respectively. The spheroids-filled GelMA solution was crosslinked to create the bilayer hydrogel, which demonstrated a strong interfacial adhesion between the two layers. The cell sprouting enhanced the adhesion of each hydrogel, demonstrated by increase in tensile strength from 4.8 ± 0.4 to 6.9 ± 1.2 MPa after 14 days of culture. Importantly, the spatially confined delivery of BMP-2 within the spheroids increased mineral deposition and more than threefold enhanced osteogenic genes of cells in the bone layer while the cells induced by TGF-β1 signals were apparently differentiated into chondrocytes within the cartilage layer. The results suggest that our composite spheroid-laden hydrogel could be used for the biofabrication of osteochondral tissue, which can be applied to engineer other complex tissues by delivery of appropriate biomolecules.

EFFICIENCY OF PRE-SOWING APPLICATION OF COMPLEX FERTILIZERS IN TECHNOLOGY OF GROWS OF WINTER WHEAT SOFT

The article presents the results of research on theoretical substantiation and formation of yield and grain quality of winter wheat in the conditions of the Right Bank Forest Steppe of Ukraine, depending on the pre–sowing application of a new type of fertilizers with prolonged action in the technology of pre–sowing application of winter wheat. The purpose of the study was to establish the effectiveness of the use of new fertilizers in different formulations, which were applied during the sowing of winter wheat, compared to the absolute control and the option, which was chosen as a production control – with the introduction of nitroamophoska. The research was conducted during 2019/2020–2021/2022 in the scientific laboratories and stationary crop rotation of the department of plant breeding at the VP NUBiP of Ukraine "Agronomic Research Station", which is located in the Fastiv district, of the Kyiv region. In the experiments, a high–yielding, medium–early ripening winter wheat variety of MIP Valencia was sown. Sowing was carried out in the second decade of September, the sowing rate was 5 million similar seeds per 1 ha. The predecessor was soybean. The experiment was carried out in quadruplicate. The registered area of the site is 50 m2. To establish the effectiveness of the new types of DoraSOP fertilizers, a two–factor field experiment was conducted: factor A – the type of fertilizers (Actibion, Phos, Elite), factor B – the rate of fertilizer application (80; 100; 120 kg/ha physical weight). As a result of the conducted research, the parameters and regularity of the formation of elements of the crop structure were established. With the introduction of Actibion, Phos, Elite fertilizers in all the years of our research, a greater differentiation of grains in the ear was established compared to absolute control and zonal control. The number of grains in an ear when fertilizers were applied increased by 17–50% compared to the control variant. The mass of grain from an ear in the control version was 0.74 g. In the zonal control version, it was 0.97 g in Actibion 125 versions – 1.29 g; Phos – 1.05–1.11 g; Elite – 1.20 –1.22 g. The weight of 1,000 grains is influenced by the weather conditions of the year and the provision of moisture during the period of formation and pouring of grains. The highest indicators of the mass of 1000 grains were noted in the versions using Dorasop – Actibion fertilizers – 42.4–44.1 g.; Phos – 39.0 – 41.5 g; Elite – 42.5–43.0 g. The highest yield among the studied options was obtained in the options with Actibion application, and was 6.51–6.79; Elite – 6.24–6.58; Phos – 5.11–5.56 t/ha, yield in control – 3.17, production control – 4.88 t/ha. The use of fertilizers had a positive effect on the formation of quality indicators of wheat grain. The protein content in grain when Actibion fertilizers were used increased to 13.6–13.8%, in the control variant – 11.1%, and in the production control – 13.5%. The application of Elite provided a protein content of 13.5 to 13.7%. The maximum indicators of crude gluten content were noted in variants with the use of Actibion fertilizers of 23.6 – 24.6%, slightly lower indicators were formed when using Elite – 23.6 – 24%, production control formed indicators of crude gluten at the level of 24.3%, which corresponds to the 2nd quality class. Variants using Phos post–sowing fertilizer – 19.4 – 20.0%, respectively, 3rd quality class. Even lower indicators of the amount of gluten were in the control version without application of post–sowing fertilizer – 17.5%. Conducted complex studies of DoraSOP fertilizers on winter wheat crops, made it possible to draw conclusions about the high efficiency of fertilizers. Fertilizers have a prolonged effect, are characterized by a low rate of application, surpass the production control, which was significantly higher in terms of the total application of the active substance of macroelements. The effectiveness of all types of fertilizers depends significantly on weather conditions, in particular the amount of precipitation.

On the Rod Heating Problem by Sources on the Class of Zonal Controls Using the Current and Past State at Measurement Points

We study an optimal feedback control problem for the rod heating process by means of lumped sources. The control actions are the powers of the sources, the values of which are defined on the class of zonal controls. The values of the parameters of zonal control actions are determined by subsets of the state space, to which belong the values of the process state at the measurement points at the current and past time moments. The posed problem is reduced to a parametric optimal control problem on determining a finite-dimensional vector of values of the parameters of zonal control actions. We have obtained optimality conditions for the values of the parameters of zonal control actions. These conditions contain formulas for the gradient of the objective functional with respect to the optimizable parameters. They make it possible to solve the reduced problem numerically with the application of efficient first-order optimization methods.

Https://www.bakumathj.org/archive/Vol2No2/j.bmj.033.pdf

In the paper, we consider an approach for numerical solution to the optimal feedback control problem for an object with distributed parameters on the basis of observation of the object’s phase state at its specific locations by the example of the rod heating process. The control actions are the power of the heat source, the values of which are defined on the class of “zonal” controls. The values of the parameters of zonal control actions are determined by subsets of the state space, to which belong the values of the process state at the measurement points at the current moment of time. The problem of determining zonal controls is reduced to a parametric optimal control problem on determining a finite-dimensional vector of values of the parameters of zonal control actions. We derive optimality conditions for the values of the parameters of zonal control actions. These conditions contain formulas for the gradient of the objective functional with respect to the optimizable parameters of zonal controls. They make it possible to solve the stated problem numerically with the application of efficient first-order optimization methods.

Reconstructing reflector images at the boundary between base metal and deposited metal using Plane Wave Imaging technology

The article suggests using Plane Wave Imaging (PWI) technology for ultrasonic inspection of welded joints with narrow cutting to detect cracks at the interface of the fusion of the base and deposited metal. In comparison with the digital image focusing (CFA) method, the proposed method allows you to restore images of reflectors with a higher signal-to-noise ratio, with greater speed, both recording echo signals and restoring the image of discontinuities according to different acoustic schemes, taking into account the transformation of the wave type when reflected from the edges of the object of control. Numerical and model experiments have confirmed the effectiveness of using PWI technology to increase the speed of zonal control. The application of the coherent factor increased the signal-to-noise ratio of the crack model images, both for the FMC mode and for the PWI mode.

Some problems of the organization of zonal control over the activities of subordinate investigative units

Some problems of the organization of zonal control over the activities of subordinate investigative units

A voltage coordination control strategy based on the reactive power-active network loss partitioned aggregation domain

As the scale of the power system continues to expand, it becomes more difficult to regulate the voltage of large grids in a unified manner by traditional control methods. In this paper, based on the theory of modularity function model in complex networks, a voltage coordination control method of partitioning the aggregated domain of reactive-voltage sensitivity weights and active network loss-voltage sensitivity weights of power systems is proposed. Firstly, the system is partitioned according to the modularity function model and the concept of aggregation domain is proposed. Secondly, the reasonableness of the aggregation domain is judged by using the proposed reactive power support capability index, and the partitioned voltage control strategy is proposed to realize the optimal and reasonable control of the voltage crossing point. Finally, the simulation experiment compares the voltage regulation results of the centralized control method and the zonal control method. The zoned control method provides a relative voltage improvement of 3.27% over the centralized control method, the active network loss of the zoned control method is 3.30% less than that of the centralized control method, and a relative reduction in time of use of 90.70%. The simulation results show that the proposed method can effectively reduce the search range of reactive power compensation devices, reduce the number of nodes for coordinated control, reduce the active network loss of the system due to voltage regulation, and ensure the control capability of reactive power compensation devices within the partition.

Artificial Intelligence-Based Control and Coordination of Multiple PV Inverters for Reactive Power/Voltage Control of Power Distribution Networks

The integration of Renewable Energy Resources (RERs) into Power Distribution Networks (PDN) has great significance in addressing power deficiency, economics and environmental concerns. Photovoltaic (PV) technology is one of the most popular RERs, because it is simple to install and has a lot of potential. Moreover, the realization of net metering concepts further attracted consumers to benefit from PVs; however, due to ineffective coordination and control of multiple PV systems, power distribution networks face large voltage deviation. To highlight real-time control, decentralized and distributed control schemes are exploited. In the decentralized scheme, each zone (having multiple PVs) is considered an agent. These agents have zonal control and inter-zonal coordination among them. For the distributed scheme, each PV inverter is viewed as an agent. Each agent coordinates individually with other agents to control the reactive power of the system. Multi-agent actor-critic (MAAC) based framework is used for real-time coordination and control between agents. In the MAAC, an action is created by the actor network, and its value is evaluated by the critic network. The proposed scheme minimizes power losses while controlling the reactive power of PVs. The proposed scheme also maintains the voltage in a certain range of ±5%. MAAC framework is applied to the PV integrated IEEE-33 test bus system. Results are examined in light of seasonal variation in PV output and time-changing loads. The results clearly indicate that a controllable voltage ratio of 0.6850 and 0.6508 is achieved for the decentralized and distributed control schemes, respectively. As a result, voltage out of control ratio is reduced to 0.0275 for the decentralized scheme and 0.0523 for the distributed control scheme.

Cluster Partition-Based Zonal Voltage Control for Distribution Networks With High Penetrated PVs

With the high penetrated photovoltaics (PVs) accessing distribution networks (DNs) in the future, the overvoltage of distribution network will be more serious, and the voltage control will be more complex. To solve this problem, a cluster partition-based zonal voltage control method for DN is proposed in this study. First, a cluster partition method using a comprehensive performance index is proposed: in terms of DN structure, a global density quality function index is introduced to measure the coupling degree of nodes in clusters. In terms of cluster function, the inconsistency coefficient index is presented to reflect the PV output characteristics, and a node membership function index is presented to limit the scale of the cluster. Then, the DN cluster partition is carried out under the fast Newman (FN) algorithm. Second, a second-order cone programming (SOCP) model of voltage control is established to maximize the PV consumption in each cluster. To achieve the coordinated optimization of clusters, an iterative optimization strategy among clusters is proposed. Finally, the effectiveness and rationality of the proposed method are verified in a 10 kV actual feeder system in Zhejiang Province, China.

Experimental investigation of urea injection strategy for close-coupled SCR aftertreatment system to meet ultra-low NO emission regulation

• The tailpipe NOx and PM emission satisfy CARB ultra-low emission regulation under FTP cycle. • The effect of temperature and space velocity on NO x conversion is investigated. • A high NO x conversion efficiency is observed on ccSCR with air-assisted urea nozzle. • A zonal control strategy for dual urea injection is adopted to reduce tailpipe NOx emission. • The supplemental urea injection strategy is effective to reduce tailpipe NOx emission. Worldwide automotive emission regulations for heavy-duty diesel engines are increasingly stringent, especially for nitrogen oxide (NO x ) and particulate matter (PM). The development of high-efficiency aftertreatment technologies and the optimization of the urea injection strategies are key factors for the diesel engines to meet the future regulations. In this paper, the effects of temperature and space velocity on close coupled selective catalyst reduction (ccSCR) and SCR are investigated firstly. The highest NO x conversion efficiency of ccSCR and main SCR is observed at 350 °C, and an increase of space velocity leads to a more significant decrease on NO x conversion efficiency of ccSCR than that of SCR. Then three phases of urea injection state for both nozzles are determined according to the catalyst inlet temperature in the Federal Test Procedure (FTP) cycle. Urea injection strategy is optimized by urea injection ratio calibration and urea injection strategy updating based on the characteristic of three phases, as well as NH 3 sensor feedback. Finally, the composite tailpipe NO x emission under FTP cycle is reduced below 0.027 g/kW·h, satisfying California air resources board (CARB) ultra-low NO x emission regulation with a penalty of slight increase in CO 2 emissions. However, adopting a high reactivity gasoline can improve the efficiency while maintaining the low level of NO x emissions.

Energy savings from domestic zonal heating controls: Robust evidence from a controlled field trial

Domestic zonal heating controls enable hydronic systems to heat rooms to different temperatures at different times. The first credible evidence known to the authors, of the in-use energy savings of such controls, is reported. The results and research methods are globally relevant.The energy demands and room temperatures in 68, gas-heated, owner-occupied, semi-detached homes, in the English Midlands were monitored for a year before zonal controls were fitted in 37 of the homes prior to the second year of monitoring. The other homes retained the existing heating controls and so provided a matched (control) group. Surveys and questionnaires characterised the dwellings, heating systems and households.In two thirds of the homes with zonal controls the annual gas demand decreased, in one third it increased. Overall, the mean gas demand decreased by 3.5% relative to the homes that retained their existing controls. Savings were achieved primarily by reducing bedroom temperatures, especially in the evenings.Wireless, digital zonal controls are unlikely to provide an acceptable payback through reductions in energy bills at today’s prices, but they offer households the flexibility to react to time-of-use energy pricing.A matched (control) group is essential for the reliable calculation of energy demand changes arising from interventions in occupied homes.

Development of Advanced Smart Ventilation Controls for Residential Applications

This study examined the use of zoned ventilation systems using a coupled CONTAM/EnergyPlus model for new California dwellings. Several smart control strategies were developed with a target of halving ventilation-related energy use, largely through reducing dwelling ventilation rates based on zone occupancy. The controls were evaluated based on the annual energy consumption relative to continuously operating non-zoned, code-compliant mechanical ventilation systems. The systems were also evaluated from an indoor air quality perspective using the equivalency approach, where the annual personal concentration of a contaminant for a control strategy is compared to the personal concentration that would have occurred using a continuously operating, non-zoned system. Individual occupant personal concentrations were calculated for the following contaminants of concern: moisture, CO2, particles, and a generic contaminant. Zonal controls that saved energy by reducing outside airflow achieved typical reductions in ventilation-related energy of 10% to 30%, compared to the 7% savings from the unzoned control. However, this was at the expense of increased personal concentrations for some contaminants in most cases. In addition, care is required in the design and evaluation of zonal controls, because control strategies may reduce exposure to some contaminants, while increasing exposure to others.

Improving energy efficiency of HVAC systems in buildings: a review of best practices

PurposeHeating, ventilation and air-conditioning (HVAC) systems account for approximately half of all energy usage in the operational phase of a building's lifecycle. The disproportionate amount of energy usage in HVAC systems against other utilities within buildings has proved a huge cause for alarm, as this practice contributes significantly to global warming and climate change. This paper reviews the status and current trends of energy consumption associated with HVAC systems with the aim of interrogating energy efficiency practices for improving HVAC systems' consumption in buildings in the context of developing countries.Design/methodology/approachThe study relied predominantly on secondary data by analysing the relevant body of literature and proposing conceptual insights regarding best practices for improving the energy efficiency of HVAC systems in buildings. The systematic review of the literature (SLR) was aided by the PRISMA guiding principle. Content analysis technique was adopted to examine germane scholarly articles and finally grouped them into themes.FindingsBased on the SLR, measures for enhancing the energy efficiency of HVAC systems in buildings were classified based on economic considerations ranging from low-cost measures such as the cost of tuning the system, installing zonal control systems, adopting building integrated greenery systems and passive solar designs to major approaches such as HVAC smart technologies for energy management which have multi-year pay-back periods. Further, it was established that practices to improve energy efficiency in buildings range from integrated greening system into buildings to HVAC system which are human-centred and controlled to meet human modalities.Practical implicationsThere is a need to incorporate these energy efficiency practices into building regulations or codes so that built environment professionals would have a framework within which to design their buildings to be energy efficient. This energy efficient solution may serve as a prerequisite for newly constructed buildings.Originality/valueTo this end, the authors develop an integrated optimization conceptual framework mimicking energy efficiency options that may complement HVAC systems operations in buildings.

Mechanism of Support Optimization and Confined Blasting of Thick and Hard Rock with a Wedge-Structure Immediate Roof: A Case Study

Based on the occurrence conditions of a thick and hard main roof and wedge-structure immediate roof in the Zhuxianzhuang Coal Mine, the fracture characteristics and instability migration law of a thick and hard roof (THR) were examined via physical simulations. Mining zones were divided with respect to the strata behaviors and roof control difficulty levels, and the principles and methods of zonal control under THR were put forward. This study proposed a coordinated control strategy of using confined blasting in water-filled deep holes, and reasonable support optimization, which could effectively reduce the roof fracture size, increases the supporting intensity and eliminate roof-control disasters. The length of confined blasting blocks and supporting intensity were calculated using a mechanical model for roof control in the strong strata behavior zone and less-strong strata behavior zone. These key parameters were determined as 20–25 m and 1.15–1.28 MPa, respectively, and the mining strategy was successfully applied in working face 880, performing high security and reasonable economical efficiency.

Theoretical Minimum Thermal Load in Buildings

Summary Building cooling and heating accounts for a large portion of total global energy use and requires commensurate amounts of resources, which contribute significantly to global warming. Traditionally, addressing this issue has meant improving the efficiency of equipment supplying the thermal energy, reducing envelope heat transfer, and reducing air infiltration. However, this approach is already reaching practical limits. In this perspective, we explore (1) how to reduce thermal load in buildings theoretically and (2) how to achieve that reduction and dramatically lower the energy required to support building loads practically. First, we discuss our framework developed for calculating the theoretical minimum thermal load (TMTL) in buildings. Our analysis shows that current thermal loads in buildings are more than an order of magnitude higher than the TMTL. We also introduce an approximate formula to calculate energy savings from zonal control of thermal load, which shows that the majority of zonal control benefits can be achieved with fewer than 10 zones. Then, we discuss pros and cons of various approaches and strategies to achieve the TMTL. We conclude our perspective with some longer-term R&D ideas, such as thermally adaptive clothing and thermal storage to help approach the TMTL, while providing the additional benefit of interacting with the renewable grid of the future.

SYNTHESIS OF ZONAL CONTROL OF LUMPED SOURCES FOR THE HEAT CONDUCTION PROCESS

The paper studies the problem of synthesis of control of lumped sources for an object with distributed parameters based on discrete observation of the phase state at specific object points. We propose an approach in which the whole phase space at the observed points is preliminarily divided in some way into given subsets (zones). The synthesized controls are selected from the class of piecewise-constant functions, and their current values are determined by a subset of the phase space containing the population of current states of the object at the observed points, at which controls take constant values. Such synthesized controls are called zonal. We give a numerical technique for obtaining optimal values of zonal controls using efficient first-order optimization methods. To this purpose, we derive formulas for the gradient of the objective function in the space of zonal controls.

Multiple Spatiotemporal Characteristics-Based Zonal Voltage Control for High Penetrated PVs in Active Distribution Networks

The penetration of photovoltaic (PV) outputs brings great challenges to optimal operation of active distribution networks (ADNs), especially leading to more serious overvoltage problems. This study proposes a zonal voltage control scheme based on multiple spatiotemporal characteristics for highly penetrated PVs in ADNs. In the spatial domain, a community detection algorithm using a reactive/ active power quality function was introduced to partition an ADN into sub-networks. In the time domain, short-term zonal scheduling (SZS) with 1 h granularity was drawn up based on a cluster. The objective was to minimize the supported reactive power and the curtailed active power in reactive and active power sub-networks. Additionally, a real-time zonal voltage control scheme (RZVC) with 1 min granularity was proposed to correct the SZS rapidly by choosing and controlling the key PV inverter to regulate the supported reactive power and the curtailed active power of the inverters to prevent the overvoltage in each sub-network. With the time domain cooperation, the proposed method could achieve economic control and avoid overvoltage caused by errors in the forecast data of the PVs. For the spatial domain, zonal scheduling and zonal voltage control were carried out in each cluster, and the short-term scheduling and voltage controlling problem of the ADN could then be decomposed into several sub-problems. This could simplify the optimization and control which can reduce the computing time. Finally, an actual 10kV, 103-node network in Zhejiang Province of China is employed to verify the effectiveness and feasibility of the proposed approach.

The Golden Eagle, Peregrine and Solitaire fields, Blocks 14/26a and 20/01, UK North Sea

Abstract The Golden Eagle Field is located 18 km north of the Buzzard Field in the Moray Firth, and consists of oil accumulations in the Lower Cretaceous Punt and Upper Jurassic Burns Sandstone members. The development area comprises three fields, Golden Eagle, Peregrine and Solitaire, but up to 90% of the oil-in-place and ultimate recovery are in Golden Eagle. The two satellite fields are primarily structural closures, while the Golden Eagle Field reservoirs have a major element of stratigraphic pinchout. Production commenced in October 2014 and approximately 140 MMbbl of recoverable oil is anticipated over its field life from the 19 development wells (14 producers and 5 injectors) that form the initial development phase. Production performance to date has exceeded expectations, aided through the use of completions that provide zonal control of the reservoir units which has successfully supported reservoir management and improved sweep efficiency. A number of significant lessons have been learned during the early stages of the field life from the integration of dynamic data (real-time downhole fibre-optic reservoir monitoring instruments, inter- and intra-well tracers, and well interference tests) and seismic data improvements (post-start-up acquisition of high-density ocean-bottom node seismic and depth-conversion improvements).