Environmental Control Research Articles

Renewable energy supplying strategy for a greenhouse based on the water-energy-economy nexus

Nowadays, global population growth has raised issues regarding food production worldwide and greenhouses can play a critical role in addressing this issue. They increase agricultural productivity by creating controlled environmental conditions. In this research, a novel approach regarding optimizing greenhouse energy use in Iran, focusing on employing renewable energy sources is presented. It explores five cities of Tehran, Tabriz, Rasht, Bandar Abbas, and Yazd - to identify the most suitable location for a renewable-energy-driven greenhouse. The study integrates thermal modeling for environmental control within the greenhouse and calculates the required heating and cooling load which are supplied using renewable-energy driven components. The research assesses each location based on energy and water consumption, environmental impact, and cost by employing multi-criteria decision-making methods. The findings reveal Yazd, a city with hot and dry weather, as the most energy-efficient location, having 190.9 MW h of electricity consumption as well as the lowest amount of fuel consumption (18.32 Tons), while Bandar Abbas, having hot and humid weather, stands out for minimal water usage which is 2.76 m3. Therefore, it can be concluded that, this type of renewable-energy driven greenhouse would be much suitable for cities with hot and dry weather condition.

A novel method for gas mixing and distribution in multi-chamber embryo incubators.

High-quality control of the gas environment in incubators is crucial for in vitro embryo development, which requires high accuracy, fast recovery, and low gas consumption. In this study, we propose a novel gas mixing and distribution system and method as an alternative solution for multi-chamber embryo incubators. The system-based embryo incubator enables a controllable gas circulation process and a quantitative supply of CO2 and N2. To determine the optimal parameters for the mixing time and flow rate of the circulated gases, we conducted contrast experiments on the system-based incubator. To evaluate the performance of the gas system in the incubator, we conducted tests under four different initial conditions, simulating various practical application scenarios. Furthermore, we performed a mouse embryo assay to assess the system's effectiveness. The results show that the system achieved a gas concentration accuracy of ± 0.2% (volume fraction) after stabilization, a minimum recovery time of 5 minutes, an average consumption of 8.9 L/d for N2 and 0.83 L/d for CO2 during routine operation, and a blastocyst rate exceeding 90% observed after 96 hours of culture in the incubator. The system and method demonstrate a significant advantage in terms of low gas consumption compared to existing incubators, while still maintaining high accuracy and fast recovery.

Research on Optimization of University Classroom Lighting Environment Based on Computer Simulation

In order to improve the comfort of classroom users and improve the lighting environment of university classrooms, this paper puts forward different optimization schemes based on computer simulation. Dialux, a lighting environment design software, is used to numerically simulate the lighting environment of university classrooms. The classroom lighting scheme is optimized and different solutions are proposed. Through computer simulation, the effect of lighting is compared and analyzed, in order to find the most beneficial scheme for students’ mental health, which provides the basis for intelligent control of classroom lighting. The results show that the average illuminance decreases with the increase of suspension height, and the illuminance uniformity increases first and then decreases with the increase of suspension height. The solution of adjusting the projection direction and surface reflectivity of lamps is not suitable, and upgrading the type of lamps can solve the lighting environment problems and control glare. Increasing the number of lamps and adjusting the arrangement of lamps can improve the lighting environment, increase the average value but reduce the uniformity, but lead to a significant increase in energy consumption. Intelligent control based on computer simulation can solve the coordination problem of energy consumption and lighting effect. Through comparative analysis of the effects of different schemes on the classroom lighting environment in colleges and universities based on computer simulation, this paper provides data support for the selection of improved schemes, which is conducive to the selection of more suitable intelligent lighting control schemes, to ensure students’ mental health and work efficiency, and has certain reference significance for creating a healthy and comfortable classroom lighting environment.

Design of a high sensitivity and wide range angular rate sensor based on exceptional surface

Abstract It is found that when the parity time symmetry phenomenon is introduced into the resonant optical gyro system and it works near the exceptional point, the sensitivity can be significantly amplified at low angular rate in theory. However, in fact, the exceptional point is easily disturbed by external environmental variables, which means that it depends on harsh experimental environment and strong control ability, so it is difficult to move towards practical application. Here, we propose a new angular rate sensor structure based on exceptional surface, which have the advantages of high sensitivity and high robustness. The system consists of two fiber-optic ring resonators and two optical loop mirrors, and one of resonators contains a variable ratio coupler and a variable optical attenuator. We theoretically analyzed the system response and the effects of phase and coupling ratio on the system response, respectively. Finally, compared with conventional resonant gyro, the sensitivity of this exceptional surface angular rate sensor can be improved by about 300 times at low speed. In addition, by changing the loss coefficient in the ring resonator, it can achieve a wide range of 600 rad/s. This scheme provides a new approach for the development of ultra-high sensitivity and wide range angular rate sensors in the future.

The heterogeneous air pollution response to shrunk socio-economic activities in 28 major northern cities of China

Heterogeneity in air quality response to implemented measures is apparent in many studies, yet the role of regional socio-economic features in the response mechanism remains unclear. This study uses empirical method to identify the direct impact of socio-economic factors on the response to interventions of economy. We constructed a counterfactual model using machine learning methods to quantitatively assess dynamic changes in air pollution based on multiple socio-economic drivers. We find that economy interventions have indeed had an apparent but temporary impact on air quality in northern China. NO2 concentrations decreased by 45.98%, 22.81%, and 0.2%, respectively, at different policy stages, while PM2.5 decreased by 38.66%, 21.63%, and 3.62%, respectively, on average. In contrast, O3 increased by 18.62% and then returned to normal levels. We also find the heterogeneous effect of air pollutants on human activity restrictions in cities with hierarchical socio-economic backgrounds. Highly industrialized cities face greater difficulties in reducing emissions, and cities with a higher urbanization rate may have a more urgent need to take action on O3 governance. Factors such as regional economic development level, industrial structure and urbanization should be considered as important indicators in the development of hierarchical environmental control policies. Our results shed light on the dynamic changes in air pollution due to reduced socio-economic activities, and the heterogeneity between cities should be taken into account when formulating future policies in response to major events and climate change.

Estimation-based model predictive control of an electrically-heated steam methane reforming process

The surge in demand for hydrogen (H2) across diverse sectors, including clean energy transportation and chemical synthesis, underscores the need for a thorough investigation into H2 production dynamics and the development of effective controllers for industrial applications. This paper focuses on an electrically heated steam methane reforming (SMR) process for H2 production, offering advantages such as enhanced environmental sustainability, compactness, efficiency, and controllability compared to conventional reforming methods. Electric heating of the entire system allows for adjustments in current to control reactor temperature, thereby impacting hydrogen production rates. However, accurately modeling hydrogen production dynamics presents a formidable challenge, as complex models with high precision are computationally unsuitable for real-time control integration. Considering these factors, an accurate and efficient first-principles-based lumped-parameter model is developed to provide a dependable estimation of hydrogen production in an electrically-heated steam methane reformer. This model is validated experimentally and then utilized in a model predictive controller (MPC). To obtain the necessary state estimate information for the MPC, an extended Luenberger observer (ELO) method is employed to estimate state variables from limited, infrequent and delayed measurements of gas-phase reactor outlet stream and frequent measurements of the reactor temperature. Simulation comparisons with a proportional-integral (PI) controller reveal a much faster response in achieving the desired H2 production rate under the estimation-based MPC. Additionally, the simulations demonstrate the robustness of the controller to process variability such as a decrease in catalyst activation energy, commonly encountered in the SMR process, highlighting its effectiveness in maintaining stable operation under varying process conditions.

Investigation on temperature control performance of an underground confined space under ventilation

The control of thermal environment in underground structures has always been a subject of great concern. In this paper, the influence of initial surrounding rock temperature (ISRT), ventilation temperature (VT) and ventilation volume (VV), as well as internal heat source intensity (HSI) on the temperature control of ventilation risk in underground closed space is explored by building a 50-person Mine refuge chamber (MRC) model with internal heat source. The model is verified according to the experimental data, and the relative deviation is less than 4.3 %. The simulation results show that the indoor temperature (IT) is proportional to the ISRT, HSI and VT, but inversely proportional to the VV. When there are 30 people in the MRC, the ISRT and the initial IT are 32 °C, the VT is 20 °C, and the VV should exceed 450 m3/h to meet the temperature control requirements of 96 h. Taking into account the comfort of personnel, it is recommended that the air volume of 900 m3/h is more appropriate for 30 people.

Cyclic deformation response of annealed low-carbon steel: Insights from ratcheting and LCF experiments

Low cycle fatigue (LCF) and ratcheting experiments were carried out on annealed low-carbon steel at room temperature within a laboratory environment, utilising stress and strain control modes. The annealed low-carbon steel consistently demonstrates a cyclic softening response over its LCF lifespan, across all tested strain amplitudes. Notably, it was observed that ratcheting strain rises while ratcheting life declines with both rising mean stress and stress amplitude. Annealed low-carbon steel, being entirely ferritic and lacking precipitation or substitutional solid solution strengthening or hard phase strengthening, exhibits a restricted ability to withstand or alleviate the accumulation of ratcheting strain, particularly under very low mean stress conditions. In both LCF and ratcheting, significant substructure formation was detected. Nevertheless, there was no discernible difference in substructure formation between LCF and ratcheting when employing electron channelling contrast imaging techniques. The existing mean stress-based fatigue life prediction model has successfully forecasted ratcheting and LCF life within the 102–105 cycles range. A novel approach utilising modulus is introduced to characterise the cyclic hardening/softening behaviour of alloys in stress and strain-controlled experiments. The cyclic hardening model based on modulus effectively captures the responses observed in cyclic hardening/softening during LCF and ratcheting experiments.

Industrial environmental control of polycyclic aromatic hydrocarbons in organic fuel combustion product

RELEVANCE of this study lies in the computational justification of the choice of the installation location of a multipoint sampling probe in the measuring section of the flue of boiler plants of energy enterprises and thermal power plants that have a significant negative impact of emissions on the environment, in order to increase the reliability and representativeness ofinstrumental measurements during industrial environmental control (PEC) of polluting emissions (PE). PURPOSE. Improving the environmental safety of thermal power plants in the current conditions of the introduction of state principles of technological regulation of emissions is associated with the establishment of technological emission indicators for each source of atmospheric pollution at energy enterprises with a significant negative impact on the environment. In this regard, energy enterprises should carry out round-the-clock monitoring of PE, which requires reliable instrumental control of the content of marker substances in the combustion products of power boilers by determining a representative sampling point on the flue or chimney of an energy boiler installation. METHODS. The paper uses methods of computer simulation of gas dynamics to determine the local fields of concentration of PE and flow velocity and assess their unevenness in the flue of an energy boiler. RESULTS. Using the example of an operating energy boiler plant of a thermal power plant, a control section of the flue was determined to ensure industrial environmental control of marker substances in the combustion products of organic fuels. The average values of the concentration of PE and the flow rate of combustion products of local fields in the calculated sections and their values on the longitudinal axis of the boiler flue are determined, and their uneven distribution is estimated. CONCLUSION. The obtained research results can be used at energy enterprises and thermal power plants to justify the choice of a control representative measuring section for conducting a PEC, and to develop an environmental efficiency improvement program (EEIP).

The impact of environmental protection tax on corporate performance: A new insight from multi angles analysis

This study investigates the practical effects of adopting the environmental protection tax (EPT) policy on corporate performance in China. The analysis uses the Difference in Differences (DID) approach based on a quasi-natural experiment scenario. The findings indicate there is a negative impact of implementing the EPT policy on the financial performance of corporations, and the conclusion remains unchanged despite exhaustive robustness testing. The negative impact can be partly attributed to corporate technology innovation inputs. Meanwhile, enterprise property rights, pollution, and technical levels also substantially influence the implementation effect of the legislation. However, implementing this policy has improved corporations’ environmental performance and established its efficacy in enhancing their sustainable capabilities. This study comprehensively explores the impact of environmental control legislation on business performance, spanning financial, environmental, and social dimensions. Corresponding findings offer valuable insights into how firms react to environmental legislation and adjust to the external environment. Meanwhile, it also provides an objective reference for the comprehensive green transformation.

Microcosm study reveals the microbial and environmental effects on tributyltin degradation in an estuarine sediment

Tributyltin (TBT) is one of the most harmful contaminants ever released into the aquatic environment. Despite being banned, it is still present at many locations throughout the world. Its degradation in sediment mainly occurs through microbial biodegradation, a process that remains unclear. This study therefore aimed at better understanding TBT biodegradation in estuarine sediment and the microbial community associated with it. Microcosm experiments were set up, embracing a range of environmental control parameters. Major community shifts were recorded, mainly attributed to the change in oxygen status. The highest percentage of degradation (36,8%) occurred at 4 °C in anaerobic conditions. These results are encouraging for the in-situ bioremediation of TBT contaminated muddy sediment in temperate ports worldwide. However, with TBT able to persist in the coastal environment for decades when undisturbed in anoxic sediment, further research is needed to fully understand the mechanisms that triggered this biodegradation observed in the microcosms.

Environmental Monitoring and Control System of Green House with Microcontroller and GSM Using IoT Devices

Environmental Monitoring and Control System of Green House with Microcontroller and GSM Using IoT Devices

Modern environmental art design based on Artificial Intelligence technology and ecological civilization

This study delves into a novel approach for energy conservation and environmental pollution reduction through modern environmental art design, guided by the ecological civilization concept and powered by artificial intelligence (AI) technology. The environmental art framework, aligning with the ecological civilization paradigm, is intricately designed. The data acquisition layer employs diverse sensors to gather equipment status, environmental, and pollution data, transmitting it to the executive controller layer via internal WIFI connectivity. The collected data undergoes meticulous analysis and processing within the data layer before reaching the actuator control layer. Leveraging support vector machines in artificial intelligence, the executive controller layer amalgamates the analyzed equipment and environmental data to devise energy-saving equipment and environmental pollution control schemes. Real-time visualization of these outcomes is achieved through the display operation layer. Findings affirm the effectiveness of this method in acquiring pertinent data for modern environmental art design and managing equipment states. Implementation of this approach successfully diminishes power consumption, dust concentration, and formaldehyde levels in the modern environmental art design zone, showcasing its prowess in energy conservation and pollution control. The integration of AI within the ecological civilization framework highlights its potential in fostering sustainable and environmentally conscious practices in modern art creation.

SO2- and H2O-tolerant catalytic reduction of NOx at low temperatures through shielding ceria-based catalyst from poisoning: An efficient protection mechanism

Improving SO2/H2O resistance at low temperatures is a key challenge for industrial applications of NH3-SCR catalysts. Herein, a novel catalyst with remarkable low-temperature NH3-SCR activity and strong SO2/H2O resistance was designed by loading MoOx protective layer over porous kit-CeO2. The in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) coupled with basic characterization techniques were utilized to further elucidate the underlying mechanisms, and a dynamic balance between the deposition and decomposition of ammonia bisulfate was captured over porous kit-CeO2. Highly dispersed MoOx species pre-adsorbed with NH3 significantly curtailed the adsorption of NOx molecules, and the catalytic reaction over MoOx/kit-CeO2 primarily followed by the Eley-Rideal mechanism. At 250 °C, in the presence of SO2 and H2O, the Ce-O-Mo pairing site was almost unaffected and the super SO2- and H2O-tolerant property originated from the facilitated decomposition of ammonium bisulfate (ABS) and the shielding effect of Mo protective layer on SO2/H2O. This study provided an important guidance to the application of ceria-based catalysts for environmental control within low-temperature operations in non-power industries such as glass, steel, cement manufacturing, etc.

Impact of Heterogeneous Environmental Regulation on Ecological Industrialisation in the Upper Reaches of the Yangtze River in the Context of "Internet + Big Data"

The solution to the ecological and protection conundrum in the upper reaches of the Yangtze River lies in ecological industrialization, which is predicated on ecological preservation and has the capacity to convert local ecological advantages into economic advantages. Environmental regulations are essential to the ecological industrialization process since they help to solidify the base of resource endowment and guarantee the industrialization process's steady progression. There may be a relationship between environmental laws and eco-industrialization, according to the research. With the rapid development of new-generation information technology such as the Internet, big data, cloud computing and the Internet of Things, it is of great significance to strengthen the Internet and big data to empower eco-industrialisation development. Using a panel regression model, the influence and moderating function of environmental regulations on eco-industrialization were examined. The findings demonstrate that environmental rules with a focus on public engagement and command-and-control encourage area eco-industrialization. Nonetheless, the degree of regional eco-industrialization was lowered by the market incentive form of environmental control. It was also determined whether environmental laws had a moderating effect on eco-industrialization. The findings of the mediating impact demonstrate how, through the mediating function of upgrading the industrial structure, all three environmental regulations influence the evolution of eco-industrialization. In conclusion, this study makes the case that environmental legislation has a significant impact on eco-industrialization. Simultaneously, consideration needs to be given to how various forms of environmental control affect eco-industrialization. To this purpose, upgrading the eco-industrialization level of the upper reaches of the Yangtze River requires a reasonable regulation of the strength of environmental regulations. This justifies accelerating the industrial structure's upgrade.

Study of biphasic calcium phosphate (BCP) ceramics of tilapia fish bones by age

Biphasic calcium phosphate (BCP), consisting of bioceramics such as HAp + β-TCP and Ca10(PO4)6(OH)2 + Ca3(PO4)2, is a popular choice for optimizing performance due to its superior biological reabsorption and osseointegration. In this study, BCP was produced by calcining the bones of tilapia fish (Oreochromis niloticus) reared in net cages and slaughtered at an age ranging from 15 to 420 days. The bones were cleaned and dried, calcined at 900 °C for 8 h, and then subjected to high-energy grinding for 3 h to produce BCP powders. After the calcination process, the crystalline phase’s hydroxyapatite (HAp) and/or beta-tricalcium phosphate (β-TCP) were present in the composition of the bioceramic. The age-dependent variation in phase composition was confirmed by complementary vibrational spectroscopy techniques, revealing characteristic peaks and bands of the bioceramic. This variation was marked by an increase in HAp phase and a decrease in β-TCP phase. Thermogravimetric Analysis (TGA) and Differential Thermal Analysis (DTA) from 25 to 1400 °C showed the characteristic mass losses of the material, with a greater loss observed for younger fish, indicating the complete removal of organic components at temperatures above 600 °C. Comparison of the results obtained by X-Ray Diffraction (XRD) and Rietveld refinement with Raman spectroscopy showed excellent agreement. These results showed that with temperature and environment control and adequate fish feeding, it is possible to achieve the desired amounts of each phase by choosing the ideal age of the fish. This bioceramic enables precise measurement of HAp and β-TCP concentrations and Ca/P molar ratio, suitable for medical orthopedics and dentistry.

Adaptive positioning method for ball head based on impedance control

PurposeComponent positioning is an important part of aircraft assembly, aiming at the problem that it is difficult to accurately fall into the corresponding ball socket for the ball head connected with aircraft component. This study aims to propose a ball head adaptive positioning method based on impedance control.Design/methodology/approachFirst, a target impedance model for ball head positioning is constructed, and a reference positioning trajectory is generated online based on the contact force between the ball head and the ball socket. Second, the target impedance parameters were optimized based on the artificial fish swarm algorithm. Third, to improve the robustness of the impedance controller in unknown environments, a controller is designed based on model reference adaptive control (MRAC) theory and an adaptive impedance control model is built in the Simulink environment. Finally, a series of ball head positioning experiments are carried out.FindingsDuring the positioning of the ball head, the contact force between the ball head and the ball socket is maintained at a low level. After the positioning, the horizontal contact force between the ball head and the socket is less than 2 N. When the position of the contact environment has the same change during ball head positioning, the contact force between the ball head and the ball socket under standard impedance control will increase to 44 N, while the contact force of the ball head and the ball socket under adaptive impedance control will only increase to 19 N.Originality/valueIn this paper, impedance control is used to decouple the force-position relationship of the ball head during positioning, which makes the entire process of ball head positioning complete under low stress conditions. At the same time, by constructing an adaptive impedance controller based on MRAC, the robustness of the positioning system under changes in the contact environment position is greatly improved.

Environmental regulation, outward foreign direct investment, and China’s green total factor productivity

AbstractIncreasing green total factor productivity (GTFP) is currently the primary goal of sustainable development worldwide. GTFP not only reflects the efficiency of economic expansion but also encompasses resource consumption and pollution. This research enhances the current understanding of GTFP by indicating that aside from reverse technology spillovers, labor mobility, and changes in industrial structure, additional factors, such as environmental regulations, exert a dynamic function in shaping the influence of outward foreign direct investment (OFDI) on the GTFP of the home nation. The empirical findings indicate that OFDI has a single threshold effect on GTFP, and the negative effect increases with the reinforcing of environmental control. The main impact comes from home country’s changes in green technology (GTC) rather than changes in green efficiency. Additionally, environmental regulation has a positive moderating effect on OFDI, the moderating effect of environmental regulation in western regions is more pronounced in promoting the home country’s GTC. It is imperative to take into account regional variations and devise distinct policies for eastern, central, and western regions.

Environmental control of interannual and seasonal variability in dinoflagellate cyst export flux over 18 years in the Cape Blanc upwelling region (Mauritania)

The increasing threat of anthropogenic environment and climate change amplifies the urgency to investigate the effect of these changes on marine ecosystems. We provide information about the export flux of organic-walled dinoflagellate cysts between 2003 and 2020 in the upwelling ecosystem off Cape Blanc (Mauritania), one of the world’s most productive regions. We compared the cyst export flux with variability in environmental parameters, such as wind speed, wind direction, dust emission, sea surface temperature (SST), SST difference between trap location and open ocean (SSTa), and chlorophyll-a concentration. This information is valuable to determine the ecological signal of dinoflagellate cysts that could be applied in recent and paleo records. The total export production of dinoflagellate cysts fluctuated between 0 - 1.18 x 105 cysts m-2 d-1 for the heterotrophs and 0 - 1.06 x 104 cysts m-2 d-1 for the photo-/mixotrophs. The export productions of both groups were in line with changes in upwelling intensity, which in most years, intensified in spring - summer. Dinoflagellate cyst association was dominated by heterotrophic taxa that formed an average of 94% of the association throughout the sediment trap record. A strong interannual variation in the cyst export fluxes, as well as the association composition was observed in the record. We identified five groups that showed comparable variability in export production with changes in environmental conditions: (1) maximal upwelling; Echinidinium delicatum/granulatum, E. transparantum/zonneveldiae, Echinidinium spp., Trinovantedinium spp., and Protoperidinium latidorsale, (2) combined maximal upwelling and dust input; Archaeperidinium spp., P. americanum, P. stellatum, and P. subinerme, (3) upwelling relaxation; Gymnodinium spp. and L. polyedra, (4) warm surface waters; Bitectatodinium spongium and Protoceratium reticulatum, (5) species with no specific relationship to the studied environmental variables; Brigantedinium spp., E. aculeatum, Impagidinium aculeatum, P. conicum, P. monospinum, Pentapharsodinium dalei, and Spiniferites spp. The sediment trap record documented a gradual shift in the cyst taxa association that co-occurred with the gradual increase of Saharan dust input to the region, notably after 2008. The cyst association contained five photo-/mixotrophic taxa that were formed by potentially toxic dinoflagellates. The latter could cause threats to the socio-economy of coastal communities.

Environmental Policy Overlays and Urban Pollution and Carbon Reduction—Evidence from China

The in-depth promotion of environmental pollution prevention and control is a must for China to move towards green development, and the effectiveness of urban environmental pollution control largely depends on the selection of these environmental policies and the synergistic application of these policies. This paper empirically tests three environmental policies’ mixed and synergistic effects using Chinese urban data from 2000 to 2017. This study found that (1) the three environmental policies significantly curb urban environmental pollution and show synergistic effects. (2) The three types of environmental policies can have a superimposing effect by strengthening financial inputs and increasing environmental concern, as well as a complementary effect by improving the efficiency of environmental protection enforcement and the institutional environment. The synergy between the central environmental protection inspection policy and the environmental information disclosure policy is more of a superposition effect than a complementary effect due to the similarity of the policy objectives. (3) The synergistic effect of environmental policies is affected by factors such as the age of the principal officials and financial pressure. The younger the age of the principal officials and the cities with less financial pressure are more capable of utilizing the synergistic effect of environmental policies to form a situation where the market, the government, the public, and the enterprises work together to govern the city. This paper provides new ideas for exploring the synergies and mechanisms of environmental policies and theoretical references for the design, implementation, and effects of environmental policy portfolios in the 14th Five-Year Plan period.