Average Contribution Research Articles

Springtime HONO budget and its impact on the O3 production in Zibo, Shandong, China

Nitrous acid (HONO) is a vital source of OH radicals, nevertheless, the potential sources of HONO are still uncertain. To get an insight into the HONO sources and its role in atmospheric photochemistry, a comprehensive field campaign was conducted in Zibo City of the North China Plain in April 2021. A high average HONO concentration of 0.91 ppb was observed during spring. Direct emission was an important HONO source in Zibo City, with an average contribution of 32%. A calculated NO2 heterogeneous conversion efficiency of 0.37% h−1 indicated its limited contribution to the HONO formation. In addition, an unknown HONO source with an average production rate of 1.28 ppb h−1 was found through the daytime budget analysis, and the correlation analysis suggested that the photo-enhanced NO2 heterogeneous reaction on the ground surface and the nitrate (NO3−) photolysis might be the daytime HONO missing source. After incorporating the contributions of the two sources, 65% of the HONO unknown source could be explained, while there was still an unknown source with a production rate of 0.45 ppb h−1 that needed to be further explored. Furthermore, a 0-D box model was used to evaluate the role of HONO in O3 formation chemisry. The results showed that the absence of HONO led to an 83% underestimation of the OH production rate and a 45% underestimation of the net Ox production rate. This study strengthened the understanding of the HONO sources and its impact on atmospheric photochemistry in Zibo City of the North China Plain.

Tree-based ensemble machine learning model for nitrate reduction by zero-valent iron

The use of zero-valent iron (ZVI) for nitrate reduction has long been a topic of interest owing to its excellent reactivity compared to other inorganic electron donors. However, there is currently a lack of comprehensive and sophisticated models that can effectively integrate and analyze the dynamic data generated by this type of experiment. Such modeling is necessary to facilitate information mining and improve our understanding of the underlying mechanisms. Taking advantage of available published experimental data, a gradient-boosting decision tree and extreme gradient boosting were applied to 288 data points collected from peer-reviewed publications and compared with conventional non-tree-based models, i.e., artificial neural networks (ANN) and support vector regression (SVR). First, a predictive analysis was performed for the rate constant and the percentages of ammonium and nitrogen conversion using seven predictors related to ZVI properties, reactant concentration, and experimental parameters. Both tree-based models accurately predicted the target variables with comparable performance (R2 = 0.88–0.97) and outperformed ANN and SVR (R2 = 0.60–0.89). In addition, SHapley Additive exPlanations analysis revealed that ZVI properties (44 % average contribution) and experimental condition (68.5 % average contribution) were the key variables affecting the nitrate reduction rate constant and conversion product, respectively. Aerobic conditions were favorable for the conversion of nitrate to ammonium, with anoxic conditions being beneficial for the selectivity of nitrogen gas conversion. This study demonstrates a promising approach using machine learning with complex cross-system data for predicting the performance of water treatment and for mining valuable insights into the process by model interpretation. This method presents a new approach to revolutionize data analysis and modeling in water remediation, which can simplify the experimental operational burden.

A step towards a just transition in the EU: Conclusions of a regression-based energy inequality decomposition

The conceptual and regulatory framework of the European just transition does not consider inequality in household energy consumption. This study addresses the causes of this inequality across the 27 Member States of the European Union (EU) in the period 2010–2020 to contribute to its reduction. To identify these causes, the regression-based inequality decomposition approach is used. The results show that the variation in per capita gross domestic product (GDP), which contributes 38.76% to the inequality of household energy consumption, is the main cause of this inequality. Moreover, the average contribution of GDP per capita in the inequality of household energy consumption is almost negligible in the most developed states. In contrast, it is much higher in the least developed states, suggesting that decoupling between household energy consumption and economic development has not been achieved in all Member States. To promote a just transition to climate neutrality by 2050, the energy transition framework should therefore be broadened to help the least developed states achieve decoupling and align their energy consumption with that of the most developed states.

Graphene nanoparticles improve alfalfa (Medicago sativa L.) growth through multiple metabolic pathways under salinity-stressed environment

Graphene, one of the emerging carbon nanomaterials, has many advantages and applications. Salinity stress seriously affects ecology and agroforestry worldwide. The effects of graphene on alfalfa under salinity stress were investigated. The results indicated that graphene promoted alfalfa growth under non-salinity stress but caused some degree of damage to root cells and leaf parameters. Graphene used in salinity stress had a positive effect on growth parameters, chlorophyll, photosynthetic gas parameters, stomatal opening, ion balance, osmotic homeostasis, cell membrane integrity and antioxidant system, while it decreased Na+, lipid peroxidation and reactive oxygen species levels. Correlation analysis revealed that most of the parameters were significantly correlated; and principal component analysis indicated that the first two dimensions (78.1% and 4.1%) explained 82.2% of the total variability, and the majority of them exceeded the average contribution. Additionally, Gene Ontology functional enrichment analysis and Kyoto Encyclopedia of Genes and Genomes signaling pathway enrichment analysis showed that there were numerous differentially expressed genes and pathways to regulate alfalfa responding to salinity stress. Taken together, the findings reveal that graphene does not enter the plant, but improves the properties and adsorption of soil to enhance salt tolerance and seedling growth of alfalfa through morphological, physiological, biochemical, and transcriptomic aspects. Furthermore, this study provides a reference for the application of graphene to improve soil environment and agricultural production.

Evaluating the bias effects of rooting depth and cryogenic vacuum extraction to quantify root water uptake patterns in deep-rooted apple trees

Accurately assessing isotope information on water sources and mixtures is essential for determining root water uptake (RWU) patterns. This study investigates the impact of rooting depth and cryogenic vacuum extraction (CVE) on the isotopic composition of deep soil water and RWU patterns in a 19-year-old apple orchard on China’s Loess Plateau. We used a Bayesian mixing model (MixSIAR) to analyze corrected isotopic data from soil and xylem water samples collected at different depths, ranging from 3 m to 21.6 m. Our findings reveal a progressive decline in the isotopic composition of deep soil water by 0.63‰ m–1, which decreased deep soil water contributions to transpiration by 1–12% at different rooting depths. The xylem and soil water isotopes became more enriched after correction, with xylem water isotopes closer to the soil water isotope line and water isotopes enriched in the shallow soil layer. Consequently, the contributions of shallow soil water to transpiration increased after xylem water isotope correction but decreased after soil water isotope correction. Monthly averages of these ratios decreased by 12.8% or increased by 8.4%, respectively. After correcting for both soil and xylem water isotopes, the average contributions of shallow soil water increased by 7.4% each month, while those of deep soil water were not consistent. Our findings suggest that rooting depth and CVE have a greater impact on seasonal contribution ratios but a comparatively milder influence on seasonal patterns. This delineation is important for accurately quantifying plant water use strategies.

The study on morphological evolution process of gully headcut erosion in granite red soil hilly area based on an in situ scouring experiment

Gully headcut erosion (GHE) is a key process of gully erosion. However, there is a lack of effective monitoring of the spatiotemporal changes in gully head morphological characteristics that occur during the continuous GHE process. Through a continuous scouring experiment in the field, GHE morphological evolution characteristics were examined for different exposed soil layers (laterite layer and sandy layer), headcut heights (25, 50, 75, 100 and 125 cm) and flow discharge levels (60 and 120 L/min) in typical granite red soil hilly area. The results indicated that the width–depth ratio (WDR) of the erosion gullies decreased in the slope direction and that erosion gullies violently developed on the downslope when stable runoff was generated across the upstream surface. The GHE could be divided into three periods, namely, the gully formation period, active headcut period and stable erosion period, which were mainly reflected in the gully head (GH) and plunge pool erosion (PPE) below the gully bed. The gully headcut retreat (GHR) distance and headwall collapse (HC) range increased with increasing headcut height and flow discharge. PPE exhibited a disordered downward cutting pattern, and the degree of development fluctuated. The GHE degree was jointly affected by GHR, HC and PPE, and these three processes interacted. The gully headcut erosion amount (GHEA) of the laterite layer was smaller than that in the sandy layer, but the average headcut erosion contribution rate (HECR) was 58.51 %, which was higher than that of the sandy layer (48.53 %). The GHE was the main erosion path in the two soil layers, and the HECR was not affected by a single erosion process. The sandy layer was easily eroded, and the GH morphology changed markedly during scouring, while the gully erosion amount (GEA) ranged from 0.02 m3 to 0.21 m3. This was mainly affected by GH and PPE. In this study, niche-like caves may form in the sandy layer to intensify gully erosion. When the headcut height and flow discharge reached a certain degree, the GEA of the laterite layer with strong anti-erodibility will also reach a higher level, and the GEA varied between 0.01 and 0.17 m3. GHR and HC were the dominant gully erosion factors. GHE prevention should focus on the laterite layer, as an effective protective layer in granite red soil areas.

Are retirement planning tools substitutes or complements to financial capability?

We conduct a randomized controlled trial to understand how a web-based retirement saving calculator affects workers' retirement-savings decisions. In both the treatment and active control conditions, the calculator projects workers' retirement income goal. In the treatment condition only, it also projects retirement income based on defined-contribution savings, prominently displays the gap between projected goal and actual retirement income, and allows users to interactively explore how alternative, future contribution choices would affect the gap. The treatment increased average annual retirement contributions by $174 (2.3 percent). However, effects were larger for those with higher measures of financial knowledge, suggesting this type of tool complements, rather than substitutes for, underlying financial capability.

Efektivitas Dan Kontribusi Pajak Reklame Terhadap Pendapatan Asli Daerah (PAD) di Kota Medan

The purpose of the study was to determine the effectiveness of billboard tax revenue on the Regional Original Revenue of Medan City in 2019-2021 and to find out how much the contribution of billboard tax to the Original Revenue of Medan City in 2019-2021. The research uses qualitative methods that are descriptive. The types and sources of data used are primary data and secondary data. Data analysis techniques are summarizing data, presenting data, analyzing data, and preliminary conclusions that are temporary. The results showed that the effectiveness rate in 2019-2021 achieved every year was not significant, namely 44.26% for 2019; 16.69% for 2020; and 100% for 2021. The average effectiveness of billboard tax revenue on Local Original Revenue for 3 years is 53.77% or can be categorized as "ineffective". The contribution of billboard tax to Regional Original Revenue in 2019-2021 always increases but is still categorized as "undercontributing", namely 1.03% in 2019, 1.03% in 2020, and 2.01% in 2021 with an average contribution of Regional Original Revenue for 3 years of 1.38%.

Effect of Terminal Levy Contribution on Local Original Revenue

The study aims to find out: the contribution of the Wamengkoli Wara terminal levy to regional revenue. Quantitative research is the chosen research methodology. Both secondary and primary data are used. Contribution analysis is used in data analysis. The sampling method uses saturated samples over a period of 5 years, or from 2018 to 2022. All data needed to collect data based on research in the form of concepts, definitions, or theories that can be applied to explain the problem to be discussed through this research. The Regional Revenue Office, the Transportation Office, and in this case customers are secondary data sources. The study findings show that: The average contribution of the wamengkoli wara terminal levy to Regional Original Revenue during 2018-2022 is 1.63% This shows that the contribution of the terminal levy is still considered insufficient due to several things such as the COVID-19 pandemic and inter-district rental car/motorbike bus users prefer to raise and drop off passengers outside the terminal. In general, passengers who travel back and forth have private vehicles that are not collectible to the terminal Central Buton Regency is still a new pemekaran area, so the volume of terminal service users is still lacking.

Temporal and spatial changes of water quality in intensively developed urban rivers and water environment improvement: a case study of the Longgang River in Shenzhen, China.

The water quality status, spatial and temporal change processes, and water environment improvement process of urban rivers are valuable lessons to be learned under the sustainable development strategy. This study aims to reveal the water environment improvement process of intensively developed urban rivers, elucidate the spatial and temporal distribution characteristics of major pollutants, and provide recommendations for their water environment management. Water quality data from eight monitoring sites (2007-2020) in the Longgang River basin in Shenzhen, China, and comprehensive pollution index method (CPI), modified comprehensive pollution index method (M-CPI), and Pearson correlation analysis method were used for comprehensive analysis. The study shows that TN, TP, NH3-N, and COD have the greatest influence on the water quality of Longgang River, with the average pollution contribution of 53.39%, 14.49%, 11.66%, and 4.92%, in order. In 2015-2020, the water quality of the main stream of the Longgang River in the wet season was worse than that in the dry season, while the water quality of the tributaries Dingshan River and the Huangsha River in the dry season was worse than the wet season. The spatial distribution characteristics based on M-CPI indicate that the water quality of the lower reaches of Longgang River, the tributaries Dingshan River and Huangsha River, is relatively poor. In addition, the water environment improvement process of Longgang River can be divided into 3 stages: engineering stage (2007-2013, rating changed from heavily polluted to basically qualified), bottleneck stage (2013-2017, rating fluctuated slightly above and below basically qualified), and ecological restoration stage (2017-2020, rating reached qualified in 2019).

Pollution characteristics, sources, and photochemical roles of ambient carbonyl compounds in summer of Beijing, China

Ambient carbonyls are important precursors of radicals and ground-level ozone (O3). In this study, sources, precursors, and impacts on radicals and O3 of carbonyls were investigated based on online observations of volatile organic compounds (VOCs) at an urban site in Beijing during June 2021. Carbonyls accounted for 36% and 42% of mixing ratios and OH reactivity for total measured VOCs, respectively. Formaldehyde was the most abundant carbonyl, with the mean level of 4.13 ± 2.28 ppb. Source apportionment results based on the multi linear regression (MLR) method suggested that secondary production contributed 41%, 25%, 36%, and 30% of formaldehyde, acetaldehyde, propanal, and acetone, respectively. Key precursors of carbonyls were then identified based on the calculation of their production rates. It was found that alkenes contributed 59%–80% of aldehydes production. Impacts of carbonyls on HOx radicals (OH and HO2) and O3 production were explored using a box model based on observations (OBM). Photolysis of HONO, formaldehyde, and O3 were the dominant primary sources of HOx radicals during daytime of O3 pollution days, with average relative contributions of 52%, 28%, and 19% to the total primary production rate of HOx, respectively. Aldehydes accounted for 32% (20% from formaldehyde) of average HOx removal rates. The relative incremental reactivity (RIR) values of NOx determined by the OBM were negative, suggesting that the O3–VOCs-NOx sensitivity was in the VOCs-limited regime. Using the observed concentrations of carbonyls as constraints of OBM, the absolute values of RIR for NOx tended to increase but those for anthropogenic VOCs tended to decrease. Formaldehyde showed the largest RIR value for anthropogenic VOCs during O3 pollution days. These findings indicated the important impacts of carbonyls on O3 production and O3–VOCs-NOx sensitivity.

Spatiotemporal Nutrient Patterns, Stoichiometry, and Eutrophication Assessment in the Tieshan Bay Coastal Water, China

Land-source inputs into coastal water have increased remarkably in recent years, resulting in the deterioration of water quality, eutrophication, and algae blooms. However, we have limited understanding of spatiotemporal nutrient patterns, stoichiometry, and eutrophication assessment in Tieshan Bay coastal water at present. To investigate the rapid development of the coastal areas in Tieshan Bay in the South China Sea, nutrients and other physicochemical parameters were observed in Tieshan Bay during the normal season (April), wet season (July), and dry season (October) in 2021. The results showed that the average concentrations of dissolved inorganic nitrogen (DIN), dissolved inorganic phosphorus (DIP), and chemical oxygen demand (COD) in Tieshan Bay are 0.071 ± 0.115 mg/L, 0.008 ± 0.013 mg/L, and 0.71 ± 0.219 mg/L, respectively. DIN/DIP ratio ranges from 9.1–69.3, with an average value of 19.9 ± 19.2, which exceeds the Redfield value, behaving P limitations. In addition, the mean eutrophication index (EI) was low in Tieshan Bay, with an average value of 0.5 ± 1.5. Moreover, the hotspot coastal water with high DIN, DIP, and COD concentrations was located in the upper half of Tieshan Bay in all seasons. In addition to the DIN, DIP, and COD contributions to EI, the average contribution rates of DIN, DIP, and COD are 26.6%, 8.8%, and 64.6%, respectively, which leads to the largest contribution of COD to EI. Furthermore, the average comprehensive index (CI) of organic pollution in Tieshan Bay surface seawater ranged from −1 to 5.6. The seawater near Hepu in S8 station has organic pollution in wet and dry seasons, and Tieshan Bay’s middle region also has slight organic pollution. Additionally, the DIN, DIP, and COD had significant relationships with salinity (p < 0.05), suggesting that coastal water quality is affected by land-based sources input. To achieve the seawater quality target and mitigate regional eutrophication, it is critical to implement land-based source management across the river-bay-coastal water continuum.

Influence of Anthropogenic Sulfuric Acid on Different Lithological Carbonate Weathering and the Related Carbon Sink Budget: Examples from Southwest China

Accurate estimate of carbonate weathering and the related carbon sink flux induced by anthropogenic H2SO4 is of great significance for improving understanding of the hydrogeochemical evolution and the global carbon cycle. Here, to quantitatively evaluate the influence of anthropogenic H2SO4 on different lithological carbonate weathering and the related carbon sink budget, karst spring water in the typical limestone and mixed limestone–dolomite catchments in Yaji and Beidiping affected by acid precipitation in southwest China were sampled monthly for the analysis of hydrochemical and δ13CDIC characteristics. Results show for the period of sampling (August 2013 to December 2014) that the average contribution rates of atmospheric inputs and carbonate weathering to total dissolved cations are 2.24% and 97.8%, and 3.09% and 96.9% in Yaji and Beidiping, respectively. The δ13CDIC values (−17.0% to −14.7‰) and the [Ca2+ + Mg2+]/[HCO3−] (0.98 to 1.25) and [Ca2+ + Mg2+]/[HCO3− + SO42−] (approximately 1) equivalent ratios of samples prove that H2CO3 and H2SO4 simultaneously participate in carbonate weathering. The contribution rates of H2SO4 to [Ca2+ + Mg2+] and [HCO3−] produced by carbonate weathering in Yaji and Beidiping are 0–30% and 0–18%, and 0–37% and 0–23%, with average values of 14% and 7%, and 19% and 11%, respectively, suggesting that the influence of H2SO4 on different lithological carbonate weathering is different. H2SO4 precipitation participating in carbonate weathering increases the weathering rate by 14–19%, whereas it decreases the flux of karst carbon sink by 7–11% in Southwest China. Therefore, anthropogenic acids have influenced the global carbon cycle and climate change by carbonate weathering due to the large karst areas in the world, and their influences on different lithological carbonate weathering should not be ignored in the regional and global carbon cycles in future studies.

The impact of fireworks burning on air quality and their health effects in China during Spring Festivals of 2015–2022

Ambient monitoring online data of six criteria air pollutants (PM2.5, PM10, SO2, NO2, O3 and CO) in 31 provincial capital cities in China during Spring Festivals from 2015 to 2022 were analyzed to estimate contributions of fireworks burning to PM2.5 and their health effects. It shows that daily average concentrations of PM2.5, PM10, SO2, NO2, and CO during Spring Festivals of 2015-2022 dropped remarkably by 36.5%, 48.9%, 70.6%, 29.7%, and 36.8%, respectively, while 8h O3 concentrations increased significantly by 21.6%. Average contributions of fireworks burning to PM2.5 during intensive fireworks burning periods from 2015 to 2022 were 44.8 ± 14.7 %, 56.2 ± 16.9 %, 50.1 ± 16.2 %, 46.0 ± 16.8 %, 44.3 ± 14.9 %, 33.2 ± 20.7 %, 44.5 ± 15.5 % and 35.2 ± 23.3 %, respectively. The total excess health risk (ERtotal) based on Chinese Ambient Air Quality Standards (CAAQS) and World Health Organization (WHO) air quality guidelines, and health-risk based air quality index values (HAQI) were estimated. Annual average values of ERtotal based on the WHO standard were 1.5–4.7 times as many as those estimated by CAAQS standards and annual average values of HAQI based on CAAQS Grade Ⅰ standard were higher than those based on CAAQS Grade Ⅱ standard. Main health risk factors were different under different air quality standards. It is necessary to further improve air quality to protect human health during Spring Festivals in China in the future.

Analisis Laju Pertumbuhan Dan Kontribusi Penerimaan Pajak Reklame Terhadap Pendapatan Pajak Daerah (Studi Kasus Pada Kantor Badan Pendapatan Daerah Kabupaten Sikka)

The purpose of this study was to determine and analyze the Growth Rate and Contribution of Advertising Tax Revenue to Sikka District Regional Tax Revenue. The type of research used is descriptive-quantitative. Quantitative-descriptive is a method that aims to create an objective picture or description of a situation using numbers starting from data collection, interpretation of the data as well as the appearance and results. The data analysis technique in this study uses the growth rate analysis formula and the contribution formula. The results of this study show that the average growth rate of advertisement tax revenue for 2017-2021 reaches 72% and the growth rate of local tax revenue reaches 49%. The average contribution of advertisement tax revenue to regional taxes in 2017-2021 reached 1.07% with very low criteria. Efforts made by BAPENDA of Sikka Regency to increase advertisement tax revenue through intensification and extensification.

Analisis Efektivitas dan Kontribusi Penerimaan Pajak Hotel dan Pajak Reklame PAD Kota Bogor

This study aims to find out whether the realization of hotel taxes and advertisement taxes has been effective and whether these two taxes have a high contribution to the local revenue of Bogor City. This research method uses a qualitative descriptive analysis method. The research data used is secondary data, which consists of target data and realization of hotel tax revenue, advertisement tax, and PAD from 2018 to 2022. Then the data is processed using effectiveness and contribution analysis. The average level of effectiveness during 2018–2022 for hotel taxes is 121.28%, and 111.42% of advertisement taxes are considered effective. This shows that the Bogor City government has succeeded in achieving the targets of these two taxes. The average contribution rate for hotel tax is 7.89%, and hotel tax is 1.08%, which means that the proportion of hotel tax and advertisement tax makes a small or very small contribution to Bogor City's PAD revenue.

Stable isotopes reveal the surface water-groundwater interaction and variation in young water fraction in an urbanized river zone

Based on 30 sampling campaigns on precipitation, river water and groundwater in Qingbaijiang urban catchment, southwest China, this study reports the spatio-temporal evolution of water isotopes under the impacts of human activities. The seasonal variation of groundwater-surface water interaction is quantitatively evaluated by isotope-aid hydrograph separation, and the young water fraction (Fyw) in river water at different spatial locations is estimated based on the seasonal periodicity of isotopes. The results show that the stable isotopes in river water and groundwater in Qingbaijiang urban catchment grow enriched from upstream to downstream, reflecting the transformation of the dominant water source from plateau river water to local precipitation and the influence of evaporation. The operation of water conservancy projects and construction of impervious surface in urban areas increase the evaporation intensity of river water. The results of the end-member mixing analysis (EMMA) demonstrates that the average annual contributions of river water to near-bank groundwater are 60.17%, 23.55% and 24.90% in the upper, middle and lower parts, respectively. The periodic storage and release of water led by the water conservancy projects enhances the groundwater recharge in the upstream river, while the water exchanges between river water and groundwater in the middle and lower parts of the catchment are reduced. The Fyw at 8 river sections of Qingbaijiang River estimated by the isotopic amplitude ratio method ranges from 0.067 to 0.194, with an overall increasing trend from upstream to downstream. The young water fraction is negatively correlated with mean elevation, mean slope and vegetation coverage, while positively correlated with the proportion of anthropogenic land use and the proportion of low-permeable soil. The construction of impervious surfaces and drainage systems in urban and rural areas is an important driver for the elevated young water fraction.

Estimating the effectiveness of control actions on African swine fever transmission in commercial swine populations in the United States.

Given the proximity of African swine fever (ASF) to the U.S., there is an urgent need to better understand the possible dissemination pathways of the virus within the U.S. swine industry and to evaluate mitigation strategies. Here, we extended PigSpread, a farm-level spatially-explicit stochastic compartmental transmission model incorporating six transmission routes including between-farm swine movements, vehicle movements, and local spread, to model the dissemination of ASF. We then examined the effectiveness of control actions similar to the ASF national response plan. The average number of secondary infections during the first 60 days of the outbreak was 49 finisher farms, 17 nursery farms, 5 sow farms, and less than one farm in other production types. The between-farm movements of swine were the predominant route of ASF transmission with an average contribution of 71.1%, while local spread and movement of vehicles were less critical with average contributions of 14.6% and 14.4%. We demonstrated that the combination of quarantine, depopulation, movement restrictions, contact tracing, and enhanced surveillance, was the most effective mitigation strategy, resulting in an average reduction of 79.0% of secondary cases by day 140 of the outbreak. Implementing these control actions led to a median of 495,619 depopulated animals, 357,789 diagnostic tests, and 54,522 movement permits. Our results suggest that the successful elimination of an ASF outbreak is likely to require the deployment of all control actions listed in the ASF national response plan for more than 140 days, as well as estimating the resources needed for depopulation, testing, and movement permits under these controls.

Evolution and optimization of a brushless doubly‐fed machine with an asymmetrical reluctance and magductance rotor

AbstractThe brushless doubly‐fed machine (BDFM) utilizes an asymmetric composite rotor featuring salient pole reluctance and magductance to effectively compensate for the phase shift in space, as well as enhance magnetic field modulation effects, and is therefore used as a modulator. This paper evaluates the modulation capability of the modulator from the perspective of the magnetic field conversion mechanism. The theoretical evolutions of the average magnetic field conversion factors and torque contributions of various airgap field harmonics are accomplished. Additionally, multi‐objective optimization is conducted for better performance, using stratified sensitivity analysis on typical 4/2 pole pair BDFMs featuring symmetrical and asymmetric composite rotors. As a result, further improved modulation of the air gap magnetic field is expected, the cross‐coupling efficiency of the rotor is improved, and a lower output torque ripple is also achieved compared to the conventional symmetrical counterpart. Theoretical investigation of the optimized BDFM, including its effectiveness in enhancing performance metrics such as coupling factor, airgap flux density, and phase shift mechanism, is verified through 2D finite element analysis. Furthermore, a proof‐of‐concept prototype for experimentation was manufactured, which achieved good agreement with the theoretical predictions.

Environmental impact of organic and conventional wine grape production, a case study from Wuwei wine region, Gansu Province, China

The City of Wuwei was the first place in Gansu province to cultivate grapes for wine production and is representative of wine grape growing in arid areas across China. In the interest of advancing green agricultural development and in order to cope with a changing climate, viticulture in China is experiencing a shift towards greener production methods. In order to do this, a better understanding of the environmental impacts associated with production at the farm level is needed. This study assessed three different wine grape production chains (one organic and two conventional) using life cycle assessment (LCA) in the Wuwei wine region of Gansu Province. Results show that non-renewable energy (NR) consumption is higher at the pre-farm stage compared to on-farm consumption. In addition, nitrogen fertilizer (N) and electricity production, account for 32.5% and 30% respectively in conventional production, whilst in organic farming, electricity generation and pesticide production account for 62% and 22% respectively. Pre-farm activities were found to have a higher impact on global warming potential (GWP) than on-farm operations. The average contribution of N and electricity production was 36% and 32% respectively in conventional production during the pre-farm stage, while in organic farming, the contribution of electricity generation dominated at 68%. Organic fertilizer, N and electricity production are the major contributors to acidification potential (AP) and pesticide production contributes the most to eutrophication potential (EP) in the pre-farm phase·NH3 and NO3--N emissions are dominant contributors to on-farm AP and EP respectively. N2O, NH3, and NO3--N emissions are the top 3 contributors to GWP, AP and EP in the on-farm stage are mainly caused by overuse of N. In general, organic production has a lower environmental impact index than conventional farming. Options for minimizing environmental burdens include: the use of biotic materials in vineyard infrastructure; soil testing-based fertilization; deficit irrigation, policy innovation and strengthening the enabling environment for laws and regulations.