ALBERT

Description: Transient pressure analysis is a crucial tool to forecast the production performance during the exploration and production process in gas reservoirs. Usually, a regular shaped outer boundary is assumed in previous studies for well-testing analysis, which is just a simplification of practical cases and cannot reflect the actual boundaries of reservoirs. In this paper, a mathematical model is established to analyze the transient pressure behaviors of a horizontal well in an arbitrarily shaped gas reservoir. Dimensionless treatment, Laplace transformation, and boundary element method are applied in solving the model, which is verified by comparing with the results from the source function method. Based on the Stehfest numerical inversion method, the models of single-porosity media and dual-porosity media are solved respectively. Then, the time-domain curves of pseudo pressure and its derivative are obtained, and the flow regimes are identified. Finally, the impacts of some critical parameters on pressure transient behaviors are analyzed, including storativity ratio, interporosity coefficient, well length, and well orientation. This paper presents an effective way to handle complex external boundary problems in gas reservoirs.

Description: Previous research suggests that meditation, a mindfulness exercise, could result in increased connectedness to nature and pro-environmental behavior. Exposure to nature also is associated with these outcomes. It was hypothesized that meditation alongside stimuli reminiscent of the natural environment would produce enhanced effects. Participants ( N = 97) were randomly assigned to complete a 4-week online meditation program consisting of a guided meditation paired with either nature sounds (“nature group”) or spa-like sounds (“control group”). Mindfulness, connectedness to nature, and pro-environmental behavior were assessed before and after the program. Meditation, in general, produced increases in mindfulness, connectedness to nature, and pro-environmental behavior. Additionally, the nature group had a greater rate of change in connectedness to nature when compared to the control group. The results extend previous cross-sectional research by demonstrating the beneficial effects of meditation on pro-environmental behavior and its theorized mechanisms, which may be informative for future research and interventions.

Description: William Whyte originally hypothesized that the presence of people in a public space would attract more people. Contemporary planners now refer to “sticky streets” as places where pedestrians are compelled to linger and enjoy vibrant public life. We test the hypothesis that adding users to a public space will attract more people using an experimental design with confederates to add pedestrian movement and staying activity in a residential street for 45 randomly selected hours. We observed staying behavior by gender with and without our intervention. We find that the addition of public users reduced the total number of people staying in our study area, especially among women. We find that women’s right to the city may be constrained by the mere presence of other individuals, even in safe spaces and during daylight hours. Our findings suggest that Whyte’s claim is not universal, but depends on the conditions of a particular site.

Description: Diffuse nutrient pollution from agriculture has been the concern of policymakers for several decades, and yet it remains a persistent environmental issue. The current approach to mitigating the problem is predominantly via command and control regulation within the Nitrates Directive and the Water Framework Directive. This article will set out how diffuse pollution can be considered a wicked policy problem which acts as an explanation of how it has eluded the current regulatory regime. It will further establish that the traditional planning process overlooked the complexity of the problem. Finally, it will illustrate the ineffectiveness of the current regulatory framework to mitigate the problem. This will be exemplified through the legal framework of Northern Ireland.

Description: This study analyzes the feasibility of satisfying the demand of three Football Stadiums for the 2022 FIFA World Cup in Qatar, using the wind’s kinetic energy. For all three selected locations (Lusail, Al Rayyan, and Al Wakrah), the wind potentiality is calculated through an environmental parameters study, from which the wind power density is obtained. Furthermore, a commercial wind turbine with proper characteristics is selected, and the same case study for each location is presented, to quantify the capacity that wind energy offers for satisfying the maximum energy demand of each associated stadium. In addition, the environmental benefits and the time required by each wind farm to satisfy the energy demand are computed. The results reveal that the conditions enable the use of wind energy for this purpose, based on a 5.06 m/s, 4.63 m/s, and 5.18 m/s velocity mean for Lusail, Al Rayyan, and Al Wakrah, respectively; from which values of 187.49 W/m2, 150.96 W/m2, and 187.29 W/m2 of wind power density are obtained. Also, the proposed wind farms could produce 69,952.56 MWh/year, 59,550.19 MWh/year, and 75,333.70 MWh/year, respectively. Moreover, the wind farms should produce energy for a period of 5.64 h, 4.41 h, and 5.23 h, to satisfy the maximum demand by a football match in its associated location. Additionally, to avoid the implementation of a storage system, the electricity obtained from the wind is connected to the power grid, decreasing the quota of fossil fuel power plants. In consequence, Qatar will eliminate the emissions of approximately 23.376 tons of CO2 in total per trio of matches held in these stadiums. Finally, a post 2022 FIFA World Cup scenario is analyzed, obtaining a positive outcome from both environmental and economic perspectives, in which an average of 14,675 tons of CO2 and 6.03 Million US$ can be saved annually.

Description: The mining area is the main place for the development and utilization of Coalbed Methane (CBM), and there are a series of systems for the development and utilization of CBM. However, owing to lack of a clear understanding of demand-side gas consumption rules and a reasonable resource allocation system, a large amount of CBM resources in the mining area are wasted. In order to predict the demand for CBM dynamically, the Seasonal Auto Regressive Integrated Moving Average (SARIMA) model, Additive Holt-Winters (AHW) model and Multiplicative Holt-Winters (MHW) model based on time series are used to predict the monthly demand for CBM in Yangquan Mine Area in 2020, respectively. Then the predicted results are evaluated by using the prediction model parameters combined with the characteristics of actual demand for CBM. Finally, a resource allocation system under different supply and demand conditions is built to reduce the waste of resources. In this paper, it is found that the information of the actual data is not sufficiently extracted in the MHW model while the SARIMA model can reflect the cyclical trend of monthly demand for CBM under ideal conditions. Furthermore, the AHW model can reasonably predict the demand for CBM under the influence of COVID-19, with a mean relative error of 0.099. The supply and demand distribution system built based on the proposed models can solve the problem of seasonal unevenness of CBM demand in mining areas and ensure the economic benefits of mining areas.

Description: The reservoir architecture analysis of braided rivers, especially falling-silt seam forms, has played a key role in predicting remaining oil distributions. However, no studies have used architecture analyses that document braided river outcrops and researched the tapping of the few remaining oil distributions based on outcrops in the Songliao basin, northeast China. In this paper, the architecture characteristics and remaining oil distribution of braided river reservoirs are studied using a combination of an outcrop, modern deposition and subsurface well data. The new 8–13 m thick Lower Cretaceous Quantou Formation outcrop of the Songliao basin is a braided fluvial succession arranged in one large fining-upward cycle. Eight facies (Gt, St, Sm, Sh, Sp, Sw, Fl and Fm), four architecture elements (CH, DA, LV, and FF), and three orders of bounding surfaces (third-, fourth-, and fifth-order) are recognized. A new distribution pattern of falling-silt seams and a braided river architecture model are presented according to the analysis of the outcrop. In the mid-channel bar, the falling-silt seams thin from the mid-bar to the bar tail following the flow direction. Each falling-silt seam is oriented tangentially to the basal surface of the mid-channel bar, and the upper falling-silt seam extends farther than the lower one. In a Daqing Oilfield exploitation block in the Songliao basin, while channels and bars are the main reservoir units, they have different remaining oil distribution patterns. For bars, water injection wells located at the mid-bar, zonal injection technology, the drilling of horizontal wells, and proper well patterns are proposed. Fourth-order bounding surfaces, single braided channels, stacking patterns, and the lateral blocking of levees and floodplains are the key factors affecting the remaining oil distribution in channels.

Description: Channel bars are common, striking fluvio-geomorphic depositional features of alluvial rivers. The study of this article has aimed to investigate the formation, migration, and morphodynamic alteration of channel bars (n = 50) in gravel braided alluvial rivers in Darjeeling Himalayan Piedmont zone. Dynamics of micro to meso bar deposition is mainly accomplished by the channel gradient, huge upstream landslide, and variation of discharge. Multi-criteria analysis method has been used to explain the variation of principal component analysis (PCA1, PCA2, and PCA3), both monsoon to post-monsoon. Bridge scouring, empirical aggradation, and degradation values are 0.1 to 1.05 m and [Formula: see text]. Migration, re-generation, and degradation of the micro bars with their optimum morphology show changes during the rainy season. In the upper ([Formula: see text]), middle ([Formula: see text]), and lower ([Formula: see text]) piedmont region, the bar dynamic area are 0.12 to 0.71, 0.12 to 2.83, and 0.10 to 5.43 km2, respectively. In total, 58% to 72% stability of the channel bars is observed in the upper piedmont region. The coefficient of determination ( R²) of channel bar area and width shows positive (0.63) relation.

Description: Restoring and enhancing riparian vegetation on private and communal lands in Mexico is important for biodiversity conservation given the ecological significance of these areas and the scarcity of public protected areas. To enhance riparian vegetation and wildlife habitats and train local people in restoration techniques, we implemented restoration and outreach efforts on private and communal lands in the Sky Islands region of northwest Mexico. We fenced 475 ha of riparian zones from livestock, erected erosion-control structures, planted trees, and developed management agreements for cool-season grazing with landowners on 10 ranches across 3 sites in 2012-2013, then repaired fences and renegotiated agreements in 2017-2019. To foster evaluation, we used a before-after/control-impact design to measure attributes of vegetation structure and bird communities and compared baselines from 2012 with post-treatment estimates from 2019. As predicted, understory vegetation volume generally increased in treatments relative to controls ( P = .09), especially when one treatment area with the lowest pre-treatment grazing impacts was censored ( P = .01). Although canopy cover also increased, there was little differential change in treatments relative to controls ( P ⩾ .23) due likely to longer time periods needed to realize responses. Densities of most focal bird populations varied across time periods in directions that typically matched observed changes in vegetation structure, but fewer species showed signs of differential positive change linked to treatments relative to controls. Densities of Yellow-breasted Chat, a key understory obligate and important focal species, increased in treatments relative to controls across sites, as did densities of Sinaloa Wren, which also use dense underbrush ( P ⩽ .05). Positive changes by other understory obligates (eg, Common Yellowthroat, Song Sparrow) were more local but sometimes of high magnitude (〉8-fold) also suggesting positive impacts of treatments. Despite mixed results over a limited time period, these patterns suggest restoration efforts drove localized recovery of understory vegetation and associated bird populations, but benefits varied widely with environmental and social factors linked to management. Greater ecological benefits to riparian areas on private and communal lands in this region can be fostered by further incentivizing construction, maintenance, and proper use of restoration infrastructure, through education, and by building relationships based on trust and credibility with landowners.

Description: Water scarcity has increased in the last century due to the effects of climate change and the over-exploitation of anthropic activities that deteriorate strategic ecosystems in watersheds. This study quantified the water consumption of anthropic activities according to the water footprint (WF) and the water supply available (WSA) using the GR2M hydrological simulation model in the Quenane-Quenanito basin in Colombia. The objective of this study was to analyze the dynamic supply–demand of water and identify potential conflicts associated with the use of water. The results of this study show that the WF of the basin was 17.01 million m3/year, 79.97% of which was the green WF and 20.03% of which was the blue WF, and that the WSA of the basin was 272.1 million m3/year. In addition, potential conflicts over the use of water were identified due to water scarcity in 11 sub-basins during the months of January to March. In conclusion, analyzing the demand and supply of water in basins and taking into account their spatiotemporal distribution allows us to measure the impacts of anthropic activities on water resources, which can prevent potential conflicts associated with the use of water between sectors or the involvement of ecological dynamics.

Description: Investment in conservation and ecological restoration depends on various socioeconomic factors and the social license for these activities. Our study demonstrates a method for targeting management of ecosystem services based on social values, identified by respondents through a collection of social survey data. We applied the Social Values for Ecosystem Services (SolVES) geographic information systems (GIS)-based tool in the Sonoita Creek watershed, Arizona, to map social values across the watershed. The survey focused on how respondents engage with the landscape, including through their ranking of 12 social values (eg, recreational, economic, or aesthetic value) and their placement of points on a map to identify their associations with the landscape. Additional information was elicited regarding how respondents engaged with water and various land uses, as well as their familiarity with restoration terminology. Results show how respondents perceive benefits from the natural environment. Specifically, maps of social values on the landscape show high social value along streamlines. Life-sustaining services, biological diversity, and aesthetics were the respondents’ highest rated social values. Land surrounding National Forest and private lands had lower values than conservation-based and state-owned areas, which we associate with landscape features. Results can inform watershed management by allowing managers to consider social values when prioritizing restoration or conservation investments.

Description: The slaughtering of animals and processing of meats for human consumption generates enormous wastes which are not properly managed in most developing nations including Nigeria. Majority of people in Akwa Ibom state in southern Nigeria depend on meat as their major source of protein, and abattoir wastes are applied in farms as organic manure by some farmers. This study examined the role of abattoir-related waste products in the physicochemical properties, total metal, and metal speciation of the soil. The data obtained were also subjected to some treatments using some environmental models to establish the degree of contamination by the parameters determined, studied locations, and the associated human health problems. Samples were collected from 5 designated abattoirs in Akwa Ibom state. Thirty composite samples were used for the research. Results obtained showed higher levels of pH, electrical conductivity, organic matter, and cation exchange capacity in the abattoir waste–impacted soils than in the control plot. Levels of pseudo total heavy metals were also higher in the studied soils than in the control plot. The mean values of the metals are below 400, 85, 140, 36, 100, and 35 mg/kg of recommended limits for Fe, Pb, Zn, Cu, Cr, and Ni, respectively by the Federal Environmental Protection Agency (FEPA) in Nigerian soil. The results also revealed that Fe and Cr existed mainly in residual fraction. However, Zn, Cu, and Ni existed principally in the form bound to organic matter/sulfide. In addition, we detected that Pb existed mainly in the reducible fraction. Disparities were also observed in the speciation results of the metals between the studied soils and the control plot. Principal component analysis (PCA) indentified that both the geogenic and anthropogenic factors contributed to the accumulation of metals determined in the studied soils. Variable relationships were also observed for the heavy metals determined in the studied soils. Fe showed a high-risk potential, and children were more vulnerable due to its toxicity. We conclude this study was able to expose the consequences of indiscriminate dumping of abattoir wastes on the quality of soil and the associated human health problems.

Description: Pollution caused by fungal contamination on building materials contributes to poor indoor air quality. Fungi are known to cause several health-related problems, such as acute toxicity, hypersensitivity, invasive mycoses, and respiratory problems. Thus, this study aimed to determine the load and diversity of airborne culturable fungi in the dormitory rooms. An institution-based cross-sectional study was conducted from March to June 2019 at the University of Gondar students’ dormitory rooms. Statistical analyses were carried out using Stata/SE 14.0. Spearman ranks correlation was used to assess the correlation of fungal load with indoor physical parameters. The median fungal loads were 250 CFU/m3 and 157 CFU/m3 in the morning and afternoon, respectively. Most commonly identified fungal genera/species were Aspergillus, Penicillium, Alternaria, Fusarium, Candida, Trichophyton, Piedraia, Microsporum, Geotrichum, Saccharomyces, Rhodotorula, Rhizopus, Exophiala, Arthroderma, Cladosporium, Gliocladium, and Botrytis. Formaldehyde ( r = −0.2859, P = .0031), temperature ( r = −0.2153, P = .0274), and CO2 ( r = −0.3785, P = .0001) were negatively correlated with airborne indoor fungal load in the morning and CO2 ( r = 0.3183, P = .0009) and temperature ( r = 0.2046, P = .0363) positively correlated with airborne indoor fungal load in the afternoon. As a conclusion, the airborne fungal load in the dormitory room was intermediate according to the European standard of nonindustrial premises. Substantial action should be taken to reduce the fungal contamination of indoor environments.

Description: In this work, we have reported a low-cost and environmentally friendly Fe3O4-modified activated kaolin (AK-Fe3O4) composite for efficient Fenton-like degradation of 4-nitrophenol (4-NP) and optimization of the degradation variables. The AK-Fe3O4 composites were characterized by Fourier transform infrared spectroscopy, powder x-ray diffraction, scanning electron microscopy (SEM), and vibrating sample magnetometer (VSM). X-ray diffraction confirms the syntheses of pure phases of Fe3O4 and AK-Fe3O4. The SEM image of the AK-Fe3O4 composite reveals the formation of a highly porous surface. The room temperature VSM analysis describes the superparamagnetic nature of AK-Fe3O4 composites with 25 emu/g magnetization values. Response surface methodology coupled with Box-Behnken design was used to optimize the 4-NP degradation (%) variables such as contact time (10-90 minutes), 4-NP concentration (10-30 mg/L), and pH (3-8). The high regression value ( R² = 0.9964 and adjusted R² = 0.9917) and analysis of variance ( P 

Description: Heavy metals are among the most critical environmental pollutants close to industrial areas. One example is the cultivated fields in the south of Alborz industrial city in Iran, which is irrigated by treated industrial wastewater. It is contaminated by heavy metals and irrigation with wastewater treatment plants effluent, which made it salty. In this study, the application of 2 amendments, biosolids and cow manure, in improving the heavy metal accumulation in the ornamental sunflower from these types of soils was investigated. A greenhouse experiment using a completely randomized design with 4 replications and applying cow manure and biosolids in 3 weight ratios (6%, 12%, 25%) was conducted to evaluate the efficiency of sunflower in removing Pb, Ni, and Zn from the soil. Adding the amendments increased the rate of germination by 50% to 176%. Although the simultaneous utilization of cow manure in high ratios with biosolids and cow manure with low biosolids decreased the sunflower survival, nonetheless, the simultaneous addition of these organic amendments could increase the survival rate in other treatments. Moreover, the plants’ biomass was increased by adding modifiers such as cow manure and biosolids. The results showed that in treatments with 2 modifiers, the remediation factor of Pb, Zn, and Ni has increased 83.7 to 95.5, 78.4 to 87.5, and 74.9 to 94.9, respectively, in comparison to the control one. Therefore, we conclude that adding biosolids and cow manure simultaneously could improve the ornamental sunflower ability to accumulate heavy metals.

Description: Soil and water loss in agricultural fields is a global problem. Although studies about soil erosion in croplands and vineyards exist, the direct comparison between these land uses is missing, especially under continental climates in Europe. Therefore, it is needed to find control measures to the impacts of these land-use management strategies on soil properties and hydrological response. The objective of this work is to estimate and compare the impacts of croplands and vineyards under conventional management croplands and vineyards on soil properties (water holding capacity—WHC; bulk density—BD; soil water content—SWC; water stable aggregates—WSA; mean weight diameter—MWD; soil organic matter—SOM; available phosphorus—AP; total nitrogen—TN) and hydrological response (runoff—Run; sediment content—SC; sediment loss—SL; carbon loss—C loss; phosphorus loss—P loss; nitrogen loss—N loss) in Eastern Croatia. To achieve these goals, a study was set up using rainfall simulation tests at 58 mm h−1 over 30 minutes on 2 locations (Zmajevac: 45°48′N; 18°46′E; Erdut: 45°30′N; 19°01′E). In total, 32 rainfall simulations were carried out, 8 repetitions in vineyards and 8 in cropland plots of 0.876 m2, per location. Bulk density was significantly higher in cropland plots compared with the vineyard. Soil water content was significantly higher in Zmajevac cropland compared with Erdut plots. Also, SWC was significantly lower in Zmajevac vineyard than in the cropland located in the same area. Water stable aggregates and MWD were significantly higher in vineyard plots than in the cropland. Also, SOM and TN were significantly lower in Zmajevac cropland compared with the vineyard located in the same area. Available phosphorus was significantly high in Zmajevac plots than in Erdut. The rainfall simulations showed that Run was significantly higher in Erdut vineyard (8.2 L m−2) compared with Zmajevac (3.8 L m−2). Also, the Run in Erdut Cropland was significantly lower than in the vineyard. Sediment content did not show significant differences among locations. In Erdut, vineyard plots had a significantly lower SL (28.0 g m−2) than the cropland ones (39.1 g m−2). C loss was significantly higher in Zmajevac cropland than in Erdut. Also, C loss was significantly lower in Zmajevac vineyard compared with the cropland. We did not observe significant differences in P loss, and N loss also did not show significant differences. The principal component analysis showed that SOM was associated with WSA, AP, and TN. These variables were negatively related to slope, SWC, and C loss (factor 1). Also, MWD was inversely related to SL, P, and N loss (factor 2). Bulk density and SC were negatively related to Run. Overall, we conclude that noninvertive tillage practices in vineyards preserve soil structure, enhance soil quality, and reduce the extent of soil degradation.

Description: Microplastics are a global ubiquitous problem, which is becoming a major issue of concern at scientific and political levels around the world. This study presents physical and chemical characterizations of microplastic debris and a comparison between the spatial distribution and anthropogenic activities in 4 Panamanian beaches located in both sides of the Isthmus. Two of them (Juan Diaz and San Carlos beaches) are located toward the Pacific Ocean, Panamá Province, whereas the others (Palenque and Punta Galeta beaches) are located at the Caribbean Sea, Colón Province. They were chosen to show different landscape management and environmental impacts: touristic and protected areas; coastal areas that receive pollutants and marine litter from urban rivers or are used for local fishing activities. Plastic debris samples were collected and visually analyzed following the protocol proposed by the Joint Group of Experts on the Scientific Aspects of Marine Environmental Protection (GESAMP). The physical characterization of the samples consisted in the determination of variables associated with the number of plastic particles, shape, color, and size. The characterization of the polymers was performed by the attenuated total reflectance-Fourier transform infrared spectroscopy technique. A high concentration of microplastics (353 items/m2) were found at the studied sites at the Caribbean coast, whereas a lesser concentration with a greater diversity of shapes and polymer categories were found at the Pacific Coast (187 items/m2). The results indicate that, in addition to anthropogenic activities, the proximity to Panama Canal installations, as well as seasonality, natural phenomena, winds, and ocean currents may be influencing the increase in microplastic contents and the types of polymers observed.

Description: Wind resource assessments are carried out for two sites in Tuvalu: Funafuti and Nukufetau. The wind speeds at 34 and 20 m above ground level were recorded for approximately 12 months and analyzed. The averages of each site are computed as the overall, daily, monthly, annual, and seasonal averages. The overall average wind speeds for Funafuti and Nukufetau at 34 m above ground level were estimated to be 6.19 and 5.36 m/s, respectively. The turbulence intensities at the two sites were also analyzed. The turbulence intensity is also computed for windy and low-wind days. Wind shear analysis was carried out and correlated with temperature variation. Ten different methods: median and quartiles method, the empirical method of Lysen, the empirical method of Justus, the moments method, the least squares method, the maximum likelihood method, the modified maximum likelihood method, the energy pattern factor method, method of multi-objective moments, and the wind atlas analysis and application program method were used to find the Weibull parameters. From these methods, the best method is used to determine the wind power density for the site. The wind power density for Funafuti is 228.18 W/m2 and for Nukufetau is 145.1 W/m2. The site maps were digitized and with the WAsP software, five potential locations were selected for each site from the wind resource map. The annual energy production for the sites was computed using wind atlas analysis and application program to be 2921.34 and 1848.49 MWh. The payback periods of installing the turbines for each site are calculated by performing an economic analysis, which showed payback periods of between 3.13 and 4.21 years for Funafuti and between 4.83 to 6.72 years for Nukufetau.

Description: Daily, a big extent of colored, partially treated textile effluents drained into the sanitation systems causing serious environmental concerns. Therefore, the decolorization treatment process of wastewater is crucial to improve effluent quality. In the present study, 3 different sorbent materials, nano zerovalent iron (nZVI), activated carbon (AC), and green-synthesized nano zerovalent iron (GT-nZVI), have been prepared for raw textile wastewater decolourization. The prepared nanomaterials were characterized via X-ray diffraction (XRD) spectroscopy, scanning electron microscopy (SEM), energy dispersive X-ray (EDX) analysis, and UV-Vis absorption spectroscopy. In addition, the effect of different operating parameters such as pH, contact time, and stirring rate on the color removal efficiency was extensively studied to identify the optimum removal conditions. The reaction temperature, adsorbent dose, and initial color concentration were fixed during the experiments at room temperature, 0.7 g/L, and 350 and 50 mg/L Pt/Co color unit, respectively. Moreover, adsorption and reaction kinetics were analyzed using different isotherms and models. For simulating the adsorption process, artificial neural network (ANN) data were compatible with the result of regression analysis derived from response surface methodology (RSM) optimization. Our results showed the higher ability of nZVI, AC, and GT-nZVI in textile wastewater color removal. At pH 5, contact time 50 minutes, and stirring rate 150 rpm, nZVI showed good color removal efficiency of about 71% and 99% for initial color concentrations of 350 and 50 mg/L Pt/Co color unit, respectively. While slightly higher color removal ability of about 72% and 100% was achieved by using AC at pH 8, contact time 70 minutes, and stirring rate 250 rpm. Finally, the largest ability of color removal about 85% and 100% was recorded for GT-nZVI at pH 7, contact time 40 minutes, and stirring rate 150 rpm. This work shows the enhanced color removal ability of GT-nZVI as a potential textile wastewater decolourization material, opening the way for many industrial and environmental applications.

Description: Although significant progress has been achieved in the field of environmental impact assessment in many engineering disciplines, the impact of wastewater treatment plants has not yet been well integrated. In light of this remarkable scientific progress, the outputs of the plants as treated water and clean sludge have become potential sources of irrigation and energy, not a waste. The aim of this study is to assess the environmental impacts of upgrading the wastewater treatment plants from primary to secondary treatment. The Lifecycle Assessment Framework (ISO 14040 and 14044) was applied using GaBi Software. Abu Rawash wastewater treatment plant (WWTP) has been taken as a case study. Two scenarios were studied, Scenario 1 is the current situation of the WWTP using the primary treatment units and Scenario 2 is upgrading the WWTP by adding secondary treatment units. The study highlighted the influence and cumulative impact of upgrading all the primary WWTPs in Egypt to secondary treatment. With the high amount of energy consumed in the aeration process, energy recovery methods were proposed to boost the circular economy concept in Abu Rawash WWTP in order to achieve optimal results from environmental and economic perspectives.

Description: The findings and recommendations of this article will redound to the benefit of society considering that climate change regulation plays an important role in the promotion of a sustainable environment. The greater demand for a clean and healthy environment justifies the need for more effective regulation of climate change, and this can be achieved through climate change impact assessments. In the High Court case of EarthLife Africa Johannesburg v Minister of Environmental Affairs and Others, the court considered what the impact of the Thabametsi Power Project on the global climate and the changing climate will be if it is operated to the expected year of 2060. This judgement highlights the significance, place, and principles of climate change impact assessments in South Africa’s environmental law that has its founding principles in the Constitution of the Republic of South Africa, 1996. The Thabametsi-case contributed to environmental litigation in the manner as to how equality and the rule of law have been addressed in the court. This paper will examine the advances for climate change regulation in a jurisdiction where the Environmental Impact Assessment (EIA) Regulations currently refer to climate change explicitly.

Description: Water sources are currently facing great challenges from rapid population growth and industrial developments. Investigations into how to remove algal organic matter (AOM) are thus of great importance from an environmental point of view because most lakes and reservoirs in South Korea suffer from algae problems, especially in the summer. Many efforts have been made to remove AOM from the aquatic environment in South Korea. In this study, we focus on development of a new AOM removal system, utilizing waste oyster shells and ferrihydrite as the media of the filtration system. Using this system, the removal rate of AOM was investigated regarding the concentrations of chlorophyll a, total phosphorus, and alginate. It was found that about 92% of the total phosphorus was removed through this system when raw oyster shell powders were heated at 900°C to convert them into calcium oxide powders. The use of a continuous system also led to a reduction of 94.2% in total phosphorus, 78.8% in chlorophyll a, and 43.6% in alginate.

Description: Soil influences human health in a variety of ways, with human health being linked to the health of the soil. Historically, emphasis has been placed on the negative impacts that soils have on human health, including exposures to toxins and pathogenic organisms or the problems created by growing crops in nutrient-deficient soils. However, there are a number of positive ways that soils enhance human health, from food production and nutrient supply to the supply of medications and enhancement of the immune system. It is increasingly recognized that the soil is an ecosystem with a myriad of interconnected parts, each influencing the other, and when all necessary parts are present and functioning (ie, the soil is healthy), human health also benefits. Despite the advances that have been made, there are still many areas that need additional investigation. We do not have a good understanding of how chemical mixtures in the environment influence human health, and chemical mixtures in soil are the rule, not the exception. We also have sparse information on how most chemicals react within the chemically and biologically active soil ecosystem, and what those reactions mean for human health. There is a need to better integrate soil ecology and agronomic crop production with human health, food/nutrition science, and genetics to enhance bacterial and fungal sequencing capabilities, metagenomics, and the subsequent analysis and interpretation. While considerable work has focused on soil microbiology, the macroorganisms have received much less attention regarding links to human health and need considerable attention. Finally, there is a pressing need to effectively communicate soil and human health connections to our broader society, as people cannot act on information they do not have. Multidisciplinary teams of researchers, including scientists, social scientists, and others, will be essential to move all these issues forward.

Description: The PM10 contributed in the e-waste dismantling community at Banmaichaiyaphot District, Buriram Province, was investigated due to the e-waste dismantling houses randomly located neighboring non-e-waste dismantling houses. The sampling was performed at non- and e-wastes dismantling houses and compared with the reference house in Daengyai subdistrict. The 24-hour average outdoor PM10 concentrations (81.957 ± 18.724 μg/m3) at e-waste dismantling sites were higher than those of the non-e-waste dismantling houses (80.943 ± 32.740 μg/m3) and control house (36.717 ± 19.516 μg/m3). The 24-hour average indoors PM10 concentrations of the e-waste dismantling houses (116.171 ± 64.635 μg/m3) showed higher concentrations than those of the non-e-waste dismantling (113.637 ± 64.641 μg/m3) and reference house (70.907 ± 22.464 μg/m3), but there were no statistically significant differences ( P 〉 .05). Both indoor and outdoor PM10 concentrations between non- and e-waste dismantling houses did not have significant differences, whereas those of non- and e-waste dismantling houses were significantly higher than that of the reference house locating approximately 5 km away. The positive correlation between indoor and outdoor concentrations of non- and e-waste dismantling houses was satisfactory significant with the r of .613 and .825, respectively. The results indicate that the existing indoor PM10 of either non- or e-waste dismantling houses could result from neighborhood e-waste dismantling.

Description: The development of coalbed methane not only ensures the supply of natural gas but also reduces the risks of coal mine accidents. The micropore structure of coalbed methane reservoir affects the seepage of coalbed methane; improvement of pore structure is one of the effective methods to enhance the efficiency of coalbed methane exploitation. In this study, low-pressure nitrogen gas adsorption, specific surface area analysis, nuclear magnetic resonance spectroscopy, and centrifugation experiment were used to evaluate the effect of ethanol on coal microscopic pore structure and fluid distribution during hydraulic fracturing. Seven coal samples were collected from the No. 3 coal seam in Zhaozhuang Mine, Qinshui Basin. The samples are mainly composed of micropores, transition pores, and mesopores. The experimental results show that ethanol can significantly change the pore structure by increasing the pore diameter. The average specific surface area, pore volume, and pore diameter of rock samples before ethanol immersion are 1.1270 m2/g, 0.0104 cm3/g, and 14.20 nm, respectively. The three parameters of rock samples after ethanol immersion are 0.5865 m2/g, 0.0025 cm3/g, and 29.37 nm. Ethanol improves the connectivity between micropores and mesopores. The average irreducible fluid saturation of samples saturated with formation water after centrifugation is 86%, and the average irreducible fluid saturation of samples soaked in three concentrations of ethanol solution decreases. It is considered that an ethanol solution of 0.4% concentration has the best effect on improving the pore structure and fluid distribution.

Description: The hydrogen energy system based on the multi-energy complementary of renewable energy can improve the consumption of renewable energy, reduce the adverse impact on the power grid system, and has the characteristics of green, low carbon, sustainable, etc., which is currently a global research hotspot. Based on the basic principles of hydrogen production technology, this paper introduces the current hydrogen energy system topology, and summarizes the technical advantages of renewable energy complementary hydrogen production and the complementary system energy coordination forms. The problems that have been solved or reached consensus are summarized, and the current status of hydrogen energy system research at home and abroad is introduced in detail. On this basis, the key technologies of multi-energy complementation of hydrogen energy system are elaborated, especially in-depth research and discussion on coordinated control strategies, energy storage and capacity allocation, energy management, and electrolysis water hydrogen production technology. The development trend of the multi-energy complementary system and the hydrogen energy industry chain is also presented, which provides a reference for the development of hydrogen production technology and hydrogen energy utilization of the renewable energy complementary system.

Description: Shale gas production after drill-in, completion, and hydraulic fracturing is strongly affected by formation damage. In order to determine the damage mechanisms for nonmarine shale reservoir, a series of assessments of sensitivity damage, water block damage, water-based drill-in fluids damage, and water damage to gas diffusion on 20 shale samples obtained from Chang 7 Formation were conducted and analyzed. Results indicate that, in the Chang 7 Formation shale, there is extremely strong stress sensitivity and moderately weak water sensitivity damage. Although the liquid phase invasion depth is shallow and the water block damage is limited, the liquid phase and solid particles would enter the microfractures in the reservoir.The P-1 water-based drill-in fluid is compatible with the Chang 7 Formation shale reservoir which can meet the requirement of Chang 7 Formation shale damage controlling, the effect of water-based drill-in fluid on wellbore stability should be paid more attention. The diffusion coefficient of the shale decreases with the presence of water.A systematic damage evaluation method of working fluid considering the multi-mechanism and multi-scale mass transfer process of shale gas is needed to establish.

Description: This study examines the impact of financial development on carbon dioxide emissions in Nigeria over the period 1971–2014. Income per capita, energy consumption, exchange rate and urbanization are incorporated in the analysis. The empirical analysis based on linear and nonlinear autoregressive distributed lag techniques provides evidence of long-run relationship among the variables in Nigeria. The results in general show that financial development has significant asymmetric effects on carbon dioxide emissions in Nigeria. Both short-run and long-run analyses show that the impact of positive changes in financial development on carbon dioxide emissions is significantly different from that of negative changes. The results suggest that in Nigeria positive shocks in financial development have significant reducing effect on carbon dioxide emissions, while negative shocks in financial development have significant increasing effect on carbon dioxide emissions. The empirical results also show that the response of carbon dioxide emissions to negative shocks in financial development is stronger. Based on these findings, this study concludes that mitigation policies would need to incorporate strategies to strengthen the depth of financial intermediation in the Nigerian economy.

Description: Application of Weibull distribution in a generalized way to estimate wind potential cannot always be advisable. The novelty of this work is to estimate wind potential using Normal probability density function. A comparison of five probability distributions namely Normal, Gamma, Chi-Squared, Weibull, and Rayleigh was done using three performance evaluation criteria. Four years (2015–2018) hourly wind data at 50 m height at five stations near the coastline of Pakistan was used. It was found that normal distribution gives the best fit at each of these stations and against each evaluation criterion followed by Weibull distribution while Rayleigh distribution gives the poorest fit. Further energy generation by fifteen turbine models was calculated and GE 45.7 was found the best in terms of amount of energy generation and capacity factors while Vestas V42 shows the worst. However, GE/1.5 SL is the most economical while Vestas V63 is the least. Among five locations, Shahbandar is the best potential site while Manora is the least.

Description: This paper presents the field validation of a method to estimate the local wind speed on different sectors of a turbine rotor disk. Each rotating blade is used as a scanning sensor that, traveling across the rotor disk, samples the inflow. From the local speed estimates, the method can reconstruct the vertical wind shear and detect the presence and location on an impinging wake shed by an upstream wind turbine. Shear and wake awareness have multiple uses, from turbine and farm control to monitoring and forecasting. This validation study is conducted with an experimental data set obtained with two multi-megawatt wind turbines and a hub-tall met mast. Practical and simple procedures are presented and demonstrated to correct for the possible miscalibration of sensors. Results indicate a very good correlation between the estimated vertical shear and the one measured by the met mast. Additionally, the proposed method exhibits a remarkable ability to locate and track the motion of an impinging wake on an affected rotor.

Description: Human beings face unprecedented Covid-19 pandemic outbreak since the beginning of 2020. This disease started to change economic, social, and individual conventional behaviors. Several economic activities have sharply declined, and demand for commodities is decreasing, such as oil. This commodity has also suffered from disagreement among Organization of Petroleum Exporting Countries (OPEC)+ members to deal with the amount of cutting oil production. This situation adds a supply-side problem into declining demand due to Covid-19. Turkey, as an emerging economy, highly depends on imported oil and suffers from this pandemic disease. This study aims to analyze the compensating role of falling oil prices for impacts of Covid-19 on non-recoverable sectors in Turkey, e.g. tourism, travel, and transportation. The main argument in the study, that is falling prices in oil can contribute to compensation for losing revenue from tourism, travel, and transport. Throughout the study, ORANI-G as a multisectoral computable general equilibrium model is employed. Three scenarios, namely Scenario-1, 2A, and 2B, are set to analyze the effects of falling oil prices as compensation for Covid-19 in the selected sectors. Results show that Covid-19 decreases gross domestic product by 1.16 but falling oil prices as 25 and 50% compensate for this decrease by 0.72 and 1.56% gross domestic product increases, respectively. It is concluded that through the falling oil prices, Turkey’s dependence on crude oil imports might provide a new reparation to overcome non-recoverable impacts. This study is scoped with selected sectors and falling oil prices. Other economic and social sectors need to be investigated in terms of challenges of Covid-19 and opportunities for declining crude oil prices. Besides, competitiveness based on the scale of firms and the ability to access business finance should be analyzed within the changing business model in the post-coronavirus period.

Description: This analysis explores new developments in judicial review of planning policy interpretation. It shows how the nature of policy, often contextual and judgment-dependent, has led the UK Supreme Court to rethink the standard of review applicable to this issue. By considering the recent decision in Samuel Smith as part of a trilogy of cases—including Tesco Stores and Hopkins Homes—this analysis reveals a change in judicial attitudes, away from the expansive judicial supervision upheld in Tesco Stores. Furthermore, this study reflects on how this change is related to two wider ideas. The first is the Court’s understanding of the law and policy divide in the planning field, whilst the second is to do with a pragmatic stance regarding the purpose of the planning system and the institutional role of the courts in it. Finally, this analysis shows how the new approach emphasises the distinctive character of policy in the planning context.

Description: Research in environmental psychology has found a positive relationship between place bonds and behaviors related to care and maintenance of place. Although this relationship has been analyzed in natural environments, it has been less frequently studied in urban environments and has yielded contradictory results. The aim of this study is to analyze behavior related to care and conservation of neighborhood and its possible relationship to place bonds, as well as to other variables that we think may be important in explaining this behavior. The participants were 407 residents from eight different neighborhoods with different sociodemographic characteristics in one Spanish city. The results indicate that the relationship between attachment and behavior is significant only in residents with higher socioeconomic levels. These findings may help to explain the contradictory results found in the literature. Other variables which are significant in explaining neighborhood care are social norms, residential satisfaction, and support for protection policies. Place identity was not found to be significantly correlated with neighborhood care.

Description: Coalbed methane as one type of clean energy has become an important gas resource recently. High-pressure water injection in coal seams is an effective approach for improving gas extraction efficiency, which is determined by the gas displacement characteristic and pore structure of coal. To investigate the gas displacement characteristics in coal and its pore response and influential factors, gas adsorption and water injection experiments were conducted under different conditions. The results show that the gas displacement caused by the water injection undergoes three stages: rapid increase, slow increase, and almost constant. The wetting process in water injection includes three processes: wetting, soaking, and spreading, and the wettability of coking coal is best, followed by lean coal and anthracite. The amount of gas driven by the water increases with increasing water injection pressure, and it is more favorable to increase the injection pressure to improve the gas displacement effect under the relatively low injection pressure. The lower the coal rank, the better the gas displacement effect due to the higher porosity of the coal, and the longer the early gas displacement stage. The high adsorption equilibrium pressure can improve the gas displacement effect; for the relatively high adsorption equilibrium pressure, the gas displacement effect is better. After water injection in coal, the large fractures and pores dramatically increase in size, especially for the low metamorphic coals coking coal, contributing to the majority of the increase in porosity. The results of this study can provide a theoretical foundation for the wide application of water injection technology for efficient gas drainage in coal mines.

Description: This study employed the bottom-up life cycle assessment method, examining the life cycle carbon emissions of three dwellings constructed at different times with different techniques in Yinchuan City, China, i.e. traditional earth brick dwelling (Case 1), brick–straw bale dwelling (Case 2), wood–straw solar energy dwelling (Case 3). The study aimed to find the methods of reducing carbon emissions, so as to slow down the global warming. The results showed that (1) with excellent thermal insulation properties, straw bale was remarkably effective in reducing carbon emissions from heating at the use stage; (2) 15 kWp solar photovoltaic panels contributed to offsetting the carbon emission of the dwelling; (3) straw bales and logs could store the carbon in building envelope, which partly offset the carbon emissions. The findings of this study have proved that ecological building materials and solar photovoltaic system have great potential in reducing carbon emissions of buildings, and can provide a basis for the design and material selection of future dwellings in order to promote the development of green dwellings.

Description: This paper analyzes the strain stability during mining, which often causes a water inrush. Mining couses costant stress on the fault zone, which is a loading process on the system composed of fault material and surrounding medium. A cusp catastrophe model is presented and the necessary and sufficient conditions leading to fault systems are discussed. The fault zone is assumed to be planar and is a combination of two media: medium-1 is elastic-brittle or strain-hardening and medium-2 is strain-softening. The shear stress-strain constitutive model for the strain-softening medium is described by the Weibull’s distribution law. It was found that the instability of a fault system mainly relies on the ratio between the stiffness of medium1 to the post-peak stiffness of the strain-softening medium, and the homogeneity index of strain-softening medium and the bifurcation point, k ≤ 1, which is the turning point of the fault system from stability to potential instability. One can judge the occurrence of fault instability from this feature and regard the index D as a parameter, which reflects the precursory abnormality of a fault.

Description: The electricity production via these sources of energy, offers a bigger safety of supply to the consumers while respecting the environment. For that reason, the principal objective of this paper is to study and control the photovoltaic lighting energy storage system. We presented the study of the whole PV system such as solar panels, DC chopper, batteries with account of all conditions of the sites of installation (period of sunshine and temperature). This study analyzed the integration of a photovoltaic power plant, super capacitor energy storage system, and lightning system. Our approach of sizing is based on the modeling of various components describing the functioning of every part of the installation among others. We can mention the production, the consumption and the storage of energy through solar battery.

Description: Typical dolomite reservoirs exist in the upper assemblage of the Ordovician Majiagou Formation in the southeastern Sulige gas field, Ordos Basin, however, the current understanding of dolomite genesis needs to be clarified. This study confirms the dolomitization characteristics, diagenetic environment, and genesis of dolomite through the use of core observations, thin section identification, and geochemical data (carbon and oxygen stable isotopes, strontium isotopes, and major and trace element contents). The results showed that dolomite samples from the study area includes micritic dolomite, powder crystal dolomite, and micrite to powder crystal dolomite, in which the main reservoir space consisted of intergranular pores, intercrystalline pores and various dissolved pores. The δ13C value of the dolomite samples ranged from −7.26‰ to1.28‰ with an average of −0.45‰, which is equivalent to that of seawater during the Ordovician. The δ18O value ranged from −9.94‰ to −6.32‰ with an average of −7.86‰, which is clearly more negative than that of the Ordovician seawater. The 87Sr/86Sr ratio varied from 0.70867 to 0.71033 with an average of 0.70946, which is significantly more positive than that of Ordovician seawater. The Mg/Ca ratio was lower than that of the seawater and close to 1:1. Overall, all of the samples were characterized by high Fe and Mn contents, while low Sr and Na contents. These results clearly indicate that the dolomitized fluid was closely related to seawater or a sea-source fluid. Furthermore, the restored paleosalinity, paleotemperature, and paleodepth also indicate that the dolomite was formed in a marine reducing environment. Combined with the petrological characteristics and geochemical indicators, two dolomitization models (mixed water dolomitization and burial dolomitization) were established for the upper assemblage of the Ordovician Majiagou Formation in southeastern Sulige gas field. We infer that mixed water dolomitization was dominant before the Carboniferous, whereas burial dolomitization was dominant after the Early Permian.

Description: The physical properties of thick coal seams show strong vertical heterogeneity; thus, an accurate characterization of their pore structure is essential for coalbed methane (CBM) exploration and production. A total of 18 coal samples, collected from a thick coal seam in the Yili Basin of NW China, were tested by a series of laboratory experiments to investigate the peat mire evolution and pore structure characteristics. The results show that the No. 4 coal seam has undergone multiple stages of evolution in the peatification stage, and was divided into four water-transgression/water-regression cycles according to the regular cyclic changes of the vitrinite/inertinite ratio, structure preservation index, gelification index, vegetation index, trace element ratios, and stable carbon isotopes of organic matter. The changes of pore structure characteristics with the changes of coal deposition cycles are also analyzed. It is concluded that pore structure characteristics of the four cycles are quite different. In each water-transgression cycle, the vitrinite gradually increased and the inertinite gradually decreased, resulting in a decrease of the porosity, pore volume, specific surface area, and fractal dimension. While in each water-regression cycle, the vitrinite gradually decreased and the inertinite gradually increased, leading to an increase of the porosity, pore volume, specific surface area, and fractal dimension. A strong relationship exists between the porosity, pore volume, specific surface area, fractal dimension, and submacerals, with fusinite and semifusinite which contained more pores having a positive correlation, desmocollinite and corpovitrinite which contained few pores having a negative correlation.

Description: The study of benzothiophene hydrodesulfurization reaction path contribute to clarifying the mechanism of hydrodesulfurization (HDS) of heavy oil. In this work, experiments and simulations were combined to study the reaction pathway of benzothiophene hydrodesulfurization catalyzed by Ni2P. In experimental part, Ni2P catalyst was prepared and characterized. Then, the catalytic property of the catalyst for benzothiophene hydrodesulfurization was evaluated. The substance types and contents in the liquid phase products were detected to verify the accuracy of the simulation results. Dmol3 module of the Materials Studio (MS) simulation software was used to simulate the adsorption and hydrodesulfurization of benzothiophene on the surface of Ni2P catalyst and explore the most probable reaction path. The results showed that the most stable adsorption configuration of benzothiophene on the surface of Ni2P was Ni-hcp. In addition, indirect desulfurization of benzothiophene was more advantageous than direct desulfurization. The most possible path for indirect desulfurization was Benzothiophene (BT) – Dihydrobenzothiophene (DHBT) – C8H9S2 – 2-phenylethyl mercaptan (PET) – Ethylbenzene (EB), while that of direct desulfurization was Benzothiophene (BT) – C8H7S2 – Styrene thiol (CMT) – Styrene (ST) – Ethylbenzene (EB).

Description: This article discusses the regulation of ‘substances of concern’ in the circular economy (CE) in the European Union (EU). It analyses the tensions and obstacles that the present sectoral separation of waste, product and chemicals legislation sets for the development of the CE. We argue that in a longer term perspective the aim should be to erase the border between waste and chemicals regulation and create a single regime for the regulation of materials and their flow. However, the eventual aim of such non-toxic material circulation can be achieved only via precautious transitional measures that outweigh the costs and benefits of each material flow and set restrictions for the particular substances of concern. Regulatory actions addressing the risks posed by the substances of concern in the waste-based material flows are urgently needed. New measures are necessary to protect human health and the environment and to support the development of the markets for the secondary materials.

Description: Intelligent surveillance is an important management method for the construction and operation of power stations such as wind power and solar power. The identification and detection of equipment, facilities, personnel, and behaviors of personnel are the key technology for the ubiquitous electricity The Internet of Things. This paper proposes a video solution based on support vector machine and histogram of oriented gradient (HOG) methods for pedestrian safety problems that are common in night driving. First, a series of image preprocessing methods are used to optimize night images and detect lane lines. Second, an image is divided into intelligent regions to be adapted to different road environments. Finally, the HOG and support vector machine methods are used to optimize the pedestrian image on a Linux system, which reduces the number of false alarms in pedestrian detection and the workload of the pedestrian detection algorithm. The test results show that the system can successfully detect pedestrians at night. With image preprocessing optimization, the correct rate of nighttime pedestrian detection can be significantly improved, and the correct rate of detection can reach 92.4%. After the division area is optimized, the number of false alarms decreases significantly, and the average frame rate of the optimized video reaches 28 frames per second.

Description: Staged fracturing horizontal well technology is an important means of improving tight reservoir development efficiency. Taking a typical tight oil block in the Oilfield A as the studied area, the vertical well–horizontal well joint arrangement pattern is adopted in this study. The energy supplementary development effects of multiple permeability scales, different arrangement spacing, and different media (H2O, CO2) are discussed through the numerical simulation method. Combined with the principles of petroleum technology economics, the economic evaluation model for staged fracturing horizontal wells in tight oil reservoir development is proposed, thereby determining the technical boundary and economic boundary of supplementary energy development with different media. Studies indicate that the technical boundary and economic boundary of water-flooding development in the Oilfield A are 0.4 and 0.8 mD, respectively, and the technical boundary and economic boundary of CO2-flooding development are 0.1 and 0.4 mD, respectively. This study provides theoretical support for field operation of Oilfield A and guidance for selection of development mode for tight oil reservoirs.

Description: This paper discusses the volcanic influence on the mineralogical and elemental geochemistry of No. 6 coal from Nanyangpo Mine in the Datong coalfield, north China. Sixteen samples (14 coal and 2 partings) were analyzed by different geochemical methods. The results revealed that the No. 6 coal is a medium–high volatility, highly calorific, bituminous coal with a low-ash and medium-sulfur content. The minerals mainly consisted of kaolinite, calcite, dolomite, and pyrite. In addition, traces of apatite, sphalerite, and anatase were also found. Calcite, dolomite, and pyrite in the coal samples were mainly derived from epigenetic hydrothermal solutions, whereas kaolinite and apatite originated from volcanic ash. Harmful trace elements including Pb, Cu, Mo, Tl, and Hg in the No. 6 coal samples were higher than those of common global coals. These harmful elements mainly occurred in sulfide minerals, which were probably influenced by hydrothermal inputs.

Description: The inherent structural features of environmental problems cause environmental law to be written in a particular way and have led to the creation of novel adjudicative institutions, such as specialist environment courts and tribunals. But they also force us to view core constitutional principles, such as the rule of law and separation of powers, from different perspectives. By placing greater weight on certain components of these principles and lessening the force of others, solving environmental problems through law is rebalancing legal thought. Using New Zealand as a case study, this article explores how the legal infrastructure might respond to this contextual force by ensuring decision-making institutions operate with integrity and reflect public reasoned thoughtfulness, so fostering the rule of law within this unusual legal landscape.

Description: Turbulence velocity spectra are of high importance for the estimation of loads on wind turbines and other built structures, as well as for fitting measured turbulence values to turbulence models. Spectra generated from reconstructed wind vectors of Doppler beam swinging (DBS) wind lidars differ from spectra based on one-point measurements. Profiling wind lidars have several characteristics that cause these deviations, namely cross-contamination between the three velocity components, averaging along the lines of sight and the limited sampling frequency. This study focuses on analyzing the cross-contamination effect. We sample wind data in a computer-generated turbulence box to predict lidar-derived turbulence spectra for three wind directions and four measurement heights. The data are then processed with the conventional method and with the method of squeezing that reduces the longitudinal separation distances between the measurement locations of the different lidar beams by introducing a time lag into the data processing. The results are analyzed and compared to turbulence velocity spectra from field measurements with a Windcube V2 wind lidar and ultrasonic anemometers as reference. We successfully predict lidar-derived spectra for all test cases and found that their shape is dependent on the angle between the wind direction and the lidar beams. With conventional processing, cross-contamination affects all spectra of the horizontal wind velocity components. The method of squeezing improves the spectra to an acceptable level only for the case of the longitudinal wind velocity component and when the wind blows parallel to one of the lines of sight. The analysis of the simulated spectra described here improves our understanding of the limitations of turbulence measurements with DBS profiling wind lidar.

Description: Aero-servo-elastic analyses are required to determine the wind turbine loading for a wide range of load cases as specified in certification standards. The floating reference frame (FRF) formulation can be used to model the structural response of long and flexible wind turbine blades. Increasing the number of bodies in the FRF formulation of the blade increases both the fidelity of the structural model and the size of the problem. However, the turbine load analysis is a coupled aero-servo-elastic analysis, and computation cost not only depends on the size of the structural model, but also depends on the aerodynamic solver and the number of iterations between the solvers. This study presents an investigation of the performance of the different fidelity levels as measured by the computational cost and the turbine response (e.g., blade loads, tip clearance, tower-top accelerations). The analysis is based on aeroelastic simulations for normal operation in turbulent inflow load cases as defined in a design standard. Two 10 MW reference turbines are used. The results show that the turbine response quickly approaches the results of the highest-fidelity model as the number of bodies increases. The increase in computational costs to account for more bodies can almost entirely be compensated for by changing the type of the matrix solver from dense to sparse.

Description: Wind farm control strategies are being developed to mitigate wake losses in wind farms, increasing energy production. Wake steering is a type of wind farm control in which a wind turbine's yaw position is misaligned from the wind direction, causing its wake to deflect away from downstream turbines. Current modeling tools used to optimize and estimate energy gains from wake steering are designed to represent wakes for fixed wind directions. However, wake steering controllers must operate in dynamic wind conditions and a turbine's yaw position cannot perfectly track changing wind directions. Research has been conducted on robust wake steering control optimized for variable wind directions. In this paper, the design and analysis of a wake steering controller with wind direction variability is presented for a two-turbine array using the FLOw Redirection and Induction in Steady State (FLORIS) control-oriented wake model. First, the authors propose a method for modeling the turbulent and low-frequency components of the wind direction, where the slowly varying wind direction serves as the relevant input to the wake model. Next, we explain a procedure for finding optimal yaw offsets for dynamic wind conditions considering both wind direction and yaw position uncertainty. We then performed simulations with the optimal yaw offsets applied using a realistic yaw offset controller in conjunction with a baseline yaw controller, showing good agreement with the predicted energy gain using the probabilistic model. Using the Gaussian wake model in FLORIS as an example, we compared the performance of yaw offset controllers optimized for static and dynamic wind conditions for different turbine spacings and turbulence intensity values, assuming uniformly distributed wind directions. For a spacing of five rotor diameters and a turbulence intensity of 10 %, robust yaw offsets optimized for variable wind directions yielded an energy gain equivalent to 3.24 % of wake losses recovered, compared to 1.42 % of wake losses recovered with yaw offsets optimized for static wind directions. In general, accounting for wind direction variability in the yaw offset optimization process was found to improve energy production more as the separation distance increased, whereas the relative improvement remained roughly the same for the range of turbulence intensity values considered.

Description: To study the influence of coal mining on the porosity of shallow sandy loam under conditions of shallow seam mining in thick, loose layers in north-west China, a typical surface sandy loam stratum in Shaanxi Province was taken as the study area, and experiments were performed to test the variation of soil porosity at different depths of 0–10 m in strata before, during and after mining therein. The experimental results demonstrate that the overall average porosities in the disc-shaped edge area, the disc-shaped edge area to the disc-shaped basin bottom area and the disc-shaped subsidence centre area of shallow sandy loam in mining increased by (23.51, 18.07 and 22.61%) respectively compared with that before mining. Mining meant that the soil porosity in the period of stable subsidence after mining changed significantly in the disc-shaped edge area and the disc-shaped edge to the disc-shaped basin bottom area. The disc-shaped edge area shows a trend of slowly rising porosity with the increase of depth, and the disc-shaped edge area to the disc-shaped basin bottom area shows a trend of gradually increasing first and then gradually becoming stable. Although the porosity in the central area of disc-shaped subsidence increased before mining, its trend was similar to that before mining. Although the change in soil porosity in the period of post-mining settlement stability is greater than that before mining, it is best fitted by a quintic polynomial. In general, the rate of change of soil porosity in the study area shows similar trends with depth. It showed a U-shaped variation that first decreased, stabilised for a distance and then gradually increased. This study provides theoretical support for surface soil remediation and ecological environment restoration in coal mining areas.

Description: The stability of underground water-sealed oil storage caverns is of great importance for safe excavation and operation. To analyze the scope of the failure zone and underground cavern stability accurately, a new method was developed that integrates the rock tunneling quality index Q-system and stability graph method with 3D laser scanning and numerical simulation. The point cloud data were obtained by 3D laser scanning, and the cavern model was built by using DIMINE software, which directly shows the 3D shape of the cavern. The rock mass physical and mechanical parameters and the corresponding stability coefficients were obtained based on Q-system and stability graph method. The plastic zone distribution and deformation characteristics of surrounding rock were analyzed through numerical simulation. Then, the corresponding relationship between caving zone and plastic zone was determined by comparing the numerical simulation results with the 3D laser scanning contour. The new method provides a reliable way to analyze the stability of the underground water-sealed oil storage cavern and also will helpful to design or optimize the subsequent support.

Description: Aerodynamic loads need to be known for planning and defining test loads beforehand for wind turbine blades that are tested for fatigue certifications. It is known that the aerodynamic forces, especially drag, are different for tests and operation, due to the entirely different flow conditions. In test facilities, a vibrating blade will move in and out of its own wake, increasing the drag forces on the blade. This is not the case in operation. To study this special aerodynamic condition present during experimental tests, numerical simulations of a wind turbine blade during pull–release tests were conducted. High-fidelity three-dimensional computational fluid dynamics methods were used throughout the simulations. In this way, the fluid mechanisms and their impact on the moving blade are clarified, and through the coupling with a structural solver, the fluid–structure interaction is studied. Results are compared to actual measurements from experimental tests, verifying the approach. It is found that the blade experiences a high drag due to its motion towards its own whirling wake, resulting in an effective drag coefficient of approximately 5.3 for the 90∘ angle of attack. This large drag coefficient was implemented in a fatigue test load simulation, resulting in a significant decrease in bending moment along the blade, leading to less load being applied than intended. The confinement from the test facility did not impact this specific test setup, but simulations with longer blades could possibly yield different conclusions. To the knowledge of the authors, this investigation, including three-dimensional effects, structural coupling and confinement, is the first of its kind.

Description: The electrical test and assessment of wind turbines go hand in hand with standards and network connection requirements. In this paper, the generic structure of advanced electrical test benches, including grid emulator or controllable grid interface, wind torque emulator, and device under test, is proposed to harmonize state-of-the-art test sites. On the other hand, modern wind turbines are under development towards new features, concerning grid-forming, black-start, and frequency support capabilities as well as harmonic stability and control interaction considerations, to secure the robustness and stability of renewable-energy-based power systems. Therefore, it is necessary to develop new and revised test standards and methodologies to address the new features of wind turbines. This paper proposes a generic test structure within two main groups, including open-loop and closed-loop tests. The open-loop tests include the IEC 61400-21-1 standard tests as well as the additional proposed test options for the new capabilities of wind turbines, which replicate grid connection compliance tests using open-loop references for the grid emulator. In addition, the closed-loop tests evaluate the device under test as part of a virtual wind power plant and perform real-time simulations considering the grid dynamics. The closed-loop tests concern grid connection topologies consisting of AC and HVDC, as well as different electrical characteristics, including impedance, short-circuit ratio, inertia, and background harmonics. The proposed tests can be implemented using available advanced test benches by adjusting their control systems. The characteristics of a real power system can be emulated by a grid emulator coupled with real-time digital simulator systems through a high-bandwidth power-hardware-in-the-loop interface.

Description: With the continuous production of oil wells, the reservoir properties, such as permeability and porosity, are changing accordingly, and the reservoir heterogeneity is also enhanced. This development is vulnerable to the problem of the one-way advance of injected water and low efficiency of water flooding. The interwell connectivity between injection and production wells controls the flow capacity of the subsurface fluid. Therefore, the analysis of interwell connectivity helps to identify the flow direction of injected water, which is of great significance for guiding the profile control and water plugging in the later stage of the oilfield. In this study, based on the principle of mass conservation, a capacitance model considering the bottom-hole flowing pressure was established and solved by using the production dynamic data of injection–production wells. Then, the validity of the capacitance model was verified by numerical simulation, and the influences of well spacing, compression coefficient, frequent switching wells, injection speed, and bottom-hole flowing pressure on interwell connectivity were eliminated. Finally, a practical mine technique for inversion of connectivity between wells using dynamic data was developed. The advantage of this model is that the production dynamic data used in the modeling process are easy to obtain. It overcomes the shortcomings of previous models and has a wider range of applications. It can provide a theoretical basis for the formulation of profile control and water-plugging schemes in the high-water-cut period.

Description: Coalbed methane wells in the Shizhuangnan Block exhibit significant productivity differences. The reasons were determined based on the impact analysis of geological factors and drainage strategies on production capacity at 82 wells. Grey relational analysis was further utilized to quantitatively analyze the correlation degree of geological parameters to production characteristics. It is found that the main reason for wells with high water production is the ingress of external water, i.e. connecting adjacent aquifer by natural faults or artificial fractures. And aquifer characteristics, especially thickness of aquifer has the greatest influence on the water production, followed by pore connectivity, porosity, and shale content. For the wells that have not been affected by external water, the gas productivity differences are mainly affected by reservoir conditions and drainage strategies. Finally, an analytical process was proposed to provide theoretical support for rational production of coalbed methane wells.

Description: Dynamic stall phenomena carry the risk of negative damping and instability in wind turbine blades. It is crucial to model these phenomena accurately to reduce inaccuracies in predicting design driving (fatigue and extreme) loads. Some of the inaccuracies in current dynamic stall models may be due to the fact that they are not properly designed for high angles of attack and that they do not specifically describe vortex shedding behaviour. The Snel second-order dynamic stall model attempts to explicitly model unsteady vortex shedding. This model could therefore be a valuable addition to a turbine design software such as Bladed. In this paper the model has been validated with oscillating aerofoil experiments, and improvements have been proposed for reducing inaccuracies. The proposed changes led to an overall reduction in error between the model and experimental data. Furthermore the vibration frequency prediction improved significantly. The improved model has been implemented in Bladed and tested against small-scale turbine experiments at parked conditions. At high angles of attack the model looks promising for reducing mismatches between predicted and measured (fatigue and extreme) loading, leading to possible lower safety factors for design and more cost-efficient designs for future wind turbines.

Description: To achieve zero-energy building target, both China and the US have planned pathway by formulating guidelines and standards. China has published National China technical standard for nearly zero energy building (CTS-NZEB), which defines detailed principles of zero-energy building. The US LEED zero energy evaluation system has been released based on LEED rating system. Defined target and scope have been introduced in this evaluation system; however, there are no technical and detailed approaches in the rating system. To support future projects achieving the LEED Zero Energy certification in China, accessible applications have been analyzed in perspectives of technology and economy in this article. The comparison and analysis results show that the strategies and technical index of CTS-NZEB can be adopted comprehensively in LEED Zero Energy rating system for Chinese buildings except for renewable energy resources because air source or ground source heat pump system, which are extensively used in China but not acceptable in LEED Zero Energy rating system. High-performance strategies, including low U-value envelope, exterior shading devices, high air tightness envelope, high-efficiency heating, ventilation, and air-conditioning system, and low thermal bridge impact, can be applied to pursue LEED Zero Energy rating system. The incremental costs of NZEBs in China are also supported by government through market and financial policies. This would make significant impacts on Chinese buildings to achieve the LEED Zero Energy target.

Description: Current work focusses on the wind potential assessment in South Punjab. Eleven locations from South Punjab have been analyzed using two-parameter Weibull model (with Energy Pattern Factor Method to estimate Weibull parameters) and five years (2014–2018) hourly wind data measured at 50 m height and collected from Pakistan Meteorological Department. Techno-economic analysis of energy production using six different turbine models was carried out with the purpose of presenting a clear picture about the importance of turbine selection at particular location. The analysis showed that Rahim Yar Khan carries the highest wind speed, highest wind power density, and wind energy density with values 4.40 ms−1, 77.2 W/m2 and 677.76 kWh/m2/year, respectively. On the other extreme, Bahawalnagar observes the least wind speed i.e. 3.60 ms−1 while Layyah observes the minimum wind power density and wind energy density as 38.96 W/m2 and 352.24 kWh/m2/year, respectively. According to National Renewable Energy Laboratory standards, wind potential ranging from 0 to 200 W/m2 is considered poor. Economic assessment was carried out to find feasibility of the location for energy harvesting. Finally, Polar diagrams drawn to show the optimum wind blowing directions shows that optimum wind direction in the region is southwest.

Description: The adjustment and control of the water injection rate is a commonly used method for increasing the cumulative oil production of waterflooded reservoirs. This article studies the production optimization problem under the condition of a fixed total water injection rate. The production process is divided into several segments. Considering the correlation between the segment’s time intervals and the well’s injection rate distribution, a simultaneous optimization of both segmented time and injection rate is proposed for enhancing net present value. Both empirical simulations and field application demonstrate that the suggested methods produce the highest increase in net present value – of approximately 13% and 10%, respectively – and significantly improve water flooding efficiency compared to other conventional schemes, such as segmented oil production optimization, cumulative oil production optimization and Bang-Bang control. The proposed methods under a 2-segment division increase oil production efficiency and greatly reduce adjustment costs.

Description: Lithium battery is a new energy equipment. Because of its long service life and high energy density, it is widely used in various industries. However, as the number of uses increases, the life of the energy battery gradually decreases. Aging of battery will bring security risks to energy storage system. Through the life prediction of energy lithium battery, the health status of energy battery is assessed, so as to improve the safety of energy storage system. Therefore, a hybrid model is proposed to predict the life of the energy lithium battery. The lithium-ion battery capacity data are always divided into two scales, which are predicted by extreme learning machine and support vector machine model. The energy lithium-ion battery capacity attenuation data were obtained through experiments. The original signal is decomposed into five layers by using the wavelet basis function to denoise the signal. Finally, the denoised signal is synthesized. The noise reduction effect of each wavelet was analyzed. The analysis results show that the mean square error value of the Haar wavelet is 5.31e-28, which indicates that the Haar wavelet has the best noise reduction effect. Finally, the combined model was tested by using two sets of experiments. The prediction results of the combined model are compared with those of the single model. The test results show that the prediction results of the combined model are better than the single model for either experiment 1 or experiment 2. Experiment 1 indicated the root mean square error values are 29.58 and 79.68% smaller than the root mean square error values of extreme learning machine and support vector machine. The model proposed in this study has positive significance for the safety improvement of energy storage system and can promote the development and utilization of energy resources.

Description: Central air conditioning is the main energy-consuming equipment in modern large-scale commercial buildings. Its energy consumption generally accounts for more than 60% of the electricity load of an entire building, and there is a rising trend. Focusing on reducing central air conditioning energy consumption is a first priority to achieve energy savings in modern large-scale commercial buildings. To study the main influencing factors of central air conditioning energy consumption in large shopping malls, in-depth collection and analysis of energy consumption data of Shenzhen Tian-hong shopping mall were considered, and the impact of factors such as the basic composition of central air conditioning, time, and Shenzhen weather on the energy consumption of shopping malls was considered. The most representative Buji Rainbow store of the Rainbow Group is used as the research object. The influencing factors of central air conditioning on its energy consumption are divided into air conditioning pumps, host 1–1, host 1–2, host 2–1, and host 2–2. The power consumption of the freezer and the eight impact indicators of time and weather in Shenzhen were constructed using Pearson correlation coefficients and a long short-term memory neural network method to construct a regression model of the energy consumption prediction of the mall building. The average relative deviation between the predicted energy consumption values and the measured energy consumption values is less than 10%, which indicates that the main influencing factors selected in this paper can better explain the energy consumption of the mall, and the obtained energy consumption prediction model has high accuracy.

Description: In order to study the distributions of the biomarker of the continental source rocks in the Sichuan Basin, 71 source rock samples were collected from the Upper Triassic-Lower Jurassic strata in different regions. The n-alkanes, isoprenoids, terpane, sterane, sesquiterpenes, caranes and aromatics in the extracts were analyzed in detail. GC-MS analysis has been conducted to analyze the biomarker of the continental source rocks. The results of GC-MS analysis indicate that the Upper Triassic source rocks are high in the content of extended tricyclic terpanes, pristane, phytane, gammacerane, C28 regular sterane and carotene. However, they are low in content of rearranged compounds. The ratio of Pr/Ph is less than 1, with the characteristics of tricyclic terpane C21 〉 C23. The Lower Jurassic source rocks are extremely low in content (even zero) of extended tricyclic terpanes, pristane, phytane, gammacerane, C28 regular sterane and carotene, and high in content of rearranged compounds. The ratio of Pr/Ph is more than 1, with tricyclic terpane C21 〉 C23. These characteristics are still preserved after maturation. Moreover, during the sedimentation of the source rocks of T3x2–T3x3 members, the supply of continental plants was low (TAR  C29, 1-MP/9-MP  C29, 1-MP/9-MP 

Description: The geochemical feature and evolutionary history of hydrocarbons from the deep Cretaceous Bashijiqike (K1 bs) Formation tight sandstone reservoir in the Dabei Gas Field, Kuqa Depression were investigated using gas chromatography, gas chromatography–mass spectrometry, inclusions petrography and micro-thermometry, laser Raman spectroscopy, and quantitative grain fluorescence. The result indicates that natural gases from the deep sandstone reservoir are mainly composed of alkanes and belong to dry gases, of which methane accounts for 94.30–97.20% (avg. 95.64%), and ethane is 1.23–2.45% (avg. 1.95%). The stable carbon isotopic value of methane and ethane is −31.9‰ to −29.3‰ (avg. −30.3‰) and −24.2‰ to −19.4‰ (avg. −21.7‰), respectively, and this reflects the features of high-mature coal-derived gases. In addition, natural gases in the Dabei Gas Field have characteristics of coal-derived gases which were sourced from Jurassic coal measures. Oils in the Dabei Gas Field predominately originated from Triassic Huangshanjie (T3 h) Formation mudstones with some contributions from Jurassic coaly rocks. Petrological and micro-thermometry results of fluid inclusions suggest that the K1 bs Formation tight sandstone reservoirs have experienced two phases of hydrocarbons charge histories, namely “early oil and later gas.” The quantitative grain fluorescence analysis indicated that sandstone samples with quantitative grain fluorescence index value 〉5 and quantitative grain fluorescence-extraction intensity 〉40 pc in Wells DB101 and DB2 can be used as indicators for the paleo oil layers or the migration channels of later charged natural gas. The aforementioned analyses and burial and thermal histories of K1 bs sandstone reservoir demonstrated that oil charged at 10 Ma and natural gas charged at approximately 3 Ma in the study area. Furthermore, paleo-tectonic evolution enabled source rocks to mature and expel hydrocarbons, and the structurally related faults and traps provided pathways and places for hydrocarbon migration and accumulation.

Description: Secondary recovery methods such as waterflooding are often applied to depleted reservoirs for enhancing oil and gas production. Given that a large number of discretized elements are required in the numerical simulations of heterogeneous reservoirs, it is not feasible to run multiple full-physics simulations. In this regard, we propose a data-driven modeling approach to efficiently predict the hydrocarbon production and greatly reduce the computational and observation cost in such problems. We predict the fluid productions as a function of heterogeneity and injection well placement by applying artificial neural network with small number of training dataset, which are obtained with full-physics simulation models. To improve the accuracy of predictions, we utilize well data at producer and injector to achieve economic and efficient prediction without requiring any geological information on reservoir. The suggested artificial neural network modeling approach only utilizing well data enables the efficient decision making with reduced computational and observation cost.

Description: Reservoir rock contains many multi-scale, unevenly distributed pores, and the pore structures of shale in different reservoirs and geological environments vary greatly. Because the seepage velocity and pressure field are related to the pore spatial variations, the inhomogeneity of the seepage is superimposed on the anisotropy of the rock’s physical properties, which will affect the distribution of the induced cracks. A method for calculating the pore size in the bonded particle model, based on Delaunay triangulation, is proposed. A modeling approach capable of simulating the multi-scale pore distribution of actual rock is presented based on the proposed method. To understand how microcracks connect micropores in the process of fracturing, several bonded particle model samples with different pore structures were established, and numerical experiments were conducted based on the coupling calculation of the discrete seepage algorithm and discrete element method. The focus of this study was on the interactions between the distribution characteristics of multi-scale pores, the specific physical properties of the fracturing fluid, and the distribution differences of the induced cracks caused by the special seepage characteristics when using different fracturing fluids. The numerical results showed that the advantages of supercritical CO2 fracturing are maximized in deep reservoirs (high in-situ stress) and that a suitable in-situ stress condition is required (i.e. a stress ratio close to 1).

Description: Motivation has long been implicated as an antecedent to place attachment among recreationists. Research has framed this association around expectancy theory, suggesting that the realization of preferred modes of experience leads to a positive evaluation of a setting (i.e., attachment). In this study, we tested an alternative hypothesis rooted in self-determination theory, which purported that place attachment arises from the realization of human needs for autonomy, relatedness, and competence. We tested this hypothesis using structural equation modeling with data from a study of visitors to wilderness areas in the southeastern United States. Results support the proposition that perceptions of a landscape supporting autonomy, relatedness, and competence are associated with identification, dependence, and emotional connection with that landscape. Reframing the association between motivation and place attachment around psychological needs furthers the generalizability of results and highlights the importance of wilderness as a context for self-determined thought and behavior.

Description: Organic-rich marine-continental transitional shale is widely developed in the Permian Shanxi Formation in the Southern North China Basin. In this study, shale samples from the southern and northern wells of the basin were characterized by X-ray diffraction, high-pressure mercury intrusion porosimetry, low-pressure gas adsorption (N2 and CO2) and argon ion polishing-field emissions scanning electron microscopy. The pore types and structures of shale micropores, mesopores and macropores are qualitatively described; their pore size distribution and volume are quantitatively characterized; and the influencing factors of the pore volume are analyzed. The results show that the marine-continental transitional shale pores exhibit an unbalanced multimodal distribution with four peaks at 0.4–0.8 nm, 2–4 nm, 10–50 nm, and 〉10 µm. The mesopore volume is dominant, accounting for 40–70% of pores. The mesopores of the samples are slit-shaped pores and ink bottle-shaped pores. Since there is a desorption hysteresis loop on the N2 adsorption-desorption curve, most of them belong to the H4 type, and ye23-8 belongs to the mixed H2 and H4 type according to the IUPAC classification scheme. The slit-shaped pores are mainly interlayer pores and interparticle pores in clays, and the ink bottle-shaped pores are tiny dissolved pores and organic matter pores. Ro has negative correlation with the volumes of the mesopores and macropores, but it does not affect the volume of micropores. TOC has a positive correlation with the macropore and micropore volumes, and it has a negative correlation with mesopore volume. The relative contents of kaolinite and I/S have a positive correlation with the mesopore and macropore volumes. The relative content of illite has a negative correlation with the mesopore and macropore volumes. The relative content of chlorite has a negative correlation with the mesopore volume.

Description: For the first time an analytical solution for the quantification of the spatial variance of the second-order moment of correlated wind speeds was developed in this work. The spatial variance is defined as random differences in the sample variance of wind speed between different points in space. The approach is successfully verified using simulation and field data. The impact of the spatial variance on three selected applications relevant to the wind energy sector is then investigated including mitigation measures. First, the difference of the second-order moment between front-row wind turbines of Lillgrund wind farm is investigated. The variance of the difference ranges between 25 % and 48 % for turbulence intensities ranging from 7 % to 10 % and a sampling period of 10 min. It is thus suggested to use the second-order moment measured at each individual turbine as input to flow models of wind farm controllers in order to mitigate random error. Second, the impact of the spatial variance of the measured second-order moment on the verification of wind turbine performance is investigated. Misalignment between the mean wind direction and the line connecting the meteorological mast and wind turbine is observed to result in an additional random error in the observed second-order moment of wind speed. In the investigated conditions the random error was up to 34 %. Such a random error adds uncertainty to the turbulence intensity-based classification of the fatigue loads and power output of a wind turbine. To mitigate the random error, it is suggested to either filter the measured data for low angles of misalignment or quantify wind turbine performance using the ensemble-averaged measurements of the same wind conditions. Third, the verification of sensors in wind farms was investigated with respect to the impact of distant reference measurements. In the case of a misalignment between the wind direction and the line connecting sensor and reference, an increased random error will hamper the comparison of the measured second-order moments. The suggested mitigation measures are equivalent to those for the verification of turbine performance.

Description: This paper describes a method to improve and correct an engineering wind farm flow model by using operational data. Wind farm models represent an approximation of reality and therefore often lack accuracy and suffer from unmodeled physical effects. It is shown here that, by surgically inserting error terms in the model equations and learning the associated parameters from operational data, the performance of a baseline model can be improved significantly. Compared to a purely data-driven approach, the resulting model encapsulates prior knowledge beyond that contained in the training data set, which has a number of advantages. To assure a wide applicability of the method – also including existing assets – learning here is purely driven by standard operational (SCADA) data. The proposed method is demonstrated first using a cluster of three scaled wind turbines operated in a boundary layer wind tunnel. Given that inflow, wakes, and operational conditions can be precisely measured in the repeatable and controllable environment of the wind tunnel, this first application serves the purpose of showing that the correct error terms can indeed be identified. Next, the method is applied to a real wind farm situated in a complex terrain environment. Here again learning from operational data is shown to improve the prediction capabilities of the baseline model.

Description: This paper outlines a novel segment test methodology for wind turbine rotor blades. The segment test mainly aims at improving the efficiency of the fatigue test as a future test method at Fraunhofer Institute for Wind Energy Systems (IWES). While resulting in reduced testing times, target fatigue bending moments over the intended test area have to be matched within an acceptable range of overload. The numerical simulation reveals that the proposed segment testing has a significant time savings of up to 43 % and 52 % for 60 and 90 m blades. When compared to the experimental data of a 60 m full-length blade fatigue test, the proposed methodology also shows better test quality over the intended area and better certifiable regions over the outboard area.

Description: The high computational demand of large-eddy simulations (LESs) remains the biggest obstacle for a wider applicability of the method in the field of wind energy. Recent progress of GPU-based (graphics processing unit) lattice Boltzmann frameworks provides significant performance gains alleviating such constraints. The presented work investigates the potential of LES of wind turbine wakes using the cumulant lattice Boltzmann method (CLBM). The wind turbine is represented by the actuator line model (ALM). The implementation is validated and discussed by means of a code-to-code comparison to an established finite-volume Navier–Stokes solver. To this end, the ALM is subjected to both laminar and turbulent inflow while a standard Smagorinsky sub-grid-scale model is employed in the two numerical approaches. The resulting wake characteristics are discussed in terms of the first- and second-order statistics as well the spectra of the turbulence kinetic energy. The near-wake characteristics in laminar inflow are shown to match closely with differences of less than 3 % in the wake deficit. Larger discrepancies are found in the far wake and relate to differences in the point of the laminar-turbulent transition of the wake. In line with other studies, these differences can be attributed to the different orders of accuracy of the two methods. Consistently better agreement is found in turbulent inflow due to the lower impact of the numerical scheme on the wake transition. In summary, the study outlines the feasibility of wind turbine simulations using the CLBM and further validates the presented set-up. Furthermore, it highlights the computational potential of GPU-based LBM implementations for wind energy applications. For the presented cases, near-real-time performance was achieved using a single, off-the-shelf GPU on a local workstation.

Description: This paper investigates the uncertainties resulting from different measure–correlate–predict (MCP) methods to project the power and energy yield from a wind farm. The analysis is based on a case study that utilises short-term data acquired from a lidar wind measurement system deployed at a coastal site in the northern part of the island of Malta and long-term measurements from the island's international airport. The wind speed at the candidate site is measured by means of a lidar system. The predicted power output for a hypothetical offshore wind farm from the various MCP methodologies is compared to the actual power output obtained directly from the input of lidar data to establish which MCP methodology best predicts the power generated. The power output from the wind farm is predicted by inputting wind speed and direction derived from the different MCP methods into windPRO® (https://www.emd.dk/windpro, last access: 8 May 2020). The predicted power is compared to the power output generated from the actual wind and direction data by using the normalised mean absolute error (NMAE) and the normalised mean-squared error (NMSE). This methodology will establish which combination of MCP methodology and wind farm configuration will have the least prediction error. The best MCP methodology which combines prediction of wind speed and wind direction, together with the topology of the wind farm, is that using multiple linear regression (MLR). However, the study concludes that the other MCP methodologies cannot be discarded as it is always best to compare different combinations of MCP methodologies for wind speed and wind direction, together with different wake models and wind farm topologies.

Description: While many cancer centers suggest treating pain with medication and nondrug treatment, few include the use of virtual reality (VR) as an alternative for stress and pain relief therapy. The purpose of this research was to determine whether a nature-inspired VR simulation reduced stress and pain levels among patients in a cancer treatment center. Using a repeated measures design, 50 patients attending their regularly scheduled chemotherapy infusion were measured for pain and stress during their intravenous (IV)/port access. At the patient’s second visit, they viewed a nature-inspired VR simulation while receiving their IV/port access and were measured for pain and stress again. The paired, one-tailed t tests found significant increases in relaxation, feelings of peace, and positive distractions. While patients felt significantly less frustrated, measures for stress and pain were not significant. Future research should include additional stress and pain measures to determine the viability of VR for chemotherapy infusions.

Description: The extrapolation of wind speeds measured at a meteorological mast to wind turbine rotor heights is a key component in a bankable wind farm energy assessment and a significant source of uncertainty. Industry-standard methods for extrapolation include the power-law and logarithmic profiles. The emergence of machine-learning applications in wind energy has led to several studies demonstrating substantial improvements in vertical extrapolation accuracy in machine-learning methods over these conventional power-law and logarithmic profile methods. In all cases, these studies assess relative model performance at a measurement site where, critically, the machine-learning algorithm requires knowledge of the rotor-height wind speeds in order to train the model. This prior knowledge provides fundamental advantages to the site-specific machine-learning model over the power-law and log profiles, which, by contrast, are not highly tuned to rotor-height measurements but rather can generalize to any site. Furthermore, there is no practical benefit in applying a machine-learning model at a site where winds at the heights relevant for wind energy production are known; rather, its performance at nearby locations (i.e., across a wind farm site) without rotor-height measurements is of most practical interest. To more fairly and practically compare machine-learning-based extrapolation to standard approaches, we implemented a round-robin extrapolation model comparison, in which a random-forest machine-learning model is trained and evaluated at different sites and then compared against the power-law and logarithmic profiles. We consider 20 months of lidar and sonic anemometer data collected at four sites between 50 and 100 km apart in the central United States. We find that the random forest outperforms the standard extrapolation approaches, especially when incorporating surface measurements as inputs to include the influence of atmospheric stability. When compared at a single site (the traditional comparison approach), the machine-learning improvement in mean absolute error was 28 % and 23 % over the power-law and logarithmic profiles, respectively. Using the round-robin approach proposed here, this improvement drops to 20 % and 14 %, respectively. These latter values better represent practical model performance, and we conclude that round-robin validation should be the standard for machine-learning-based wind speed extrapolation methods.

Description: Recent research promotes implementing next-generation wind plant control methods to mitigate turbine-to-turbine wake effects. Numerical simulation and wind tunnel experiments have previously demonstrated the potential benefit of wind plant control for wind plant optimization, but full-scale validation of the wake-mitigating control strategies remains limited. As part of this study, the yaw and blade pitch of a utility-scale wind turbine were strategically modified for a limited time period to examine wind turbine wake response to first-order turbine control changes. Wind turbine wake response was measured using Texas Tech University's Ka-band Doppler radars and dual-Doppler scanning strategies. Results highlight some of the complexities associated with executing and analyzing wind plant control at full scale using brief experimental control periods. Some difficulties include (1) the ability to accurately implement the desired control changes, (2) identifying reliable data sources and methods to allow these control changes to be accurately quantified, and (3) attributing variations in wake structure to turbine control changes rather than a response to the underlying atmospheric conditions (e.g., boundary layer streak orientation, atmospheric stability). To better understand wake sensitivity to the underlying atmospheric conditions, wake evolution within the early-evening transition was also examined using a single-Doppler data collection approach. Analysis of both wake length and meandering during this period of transitioning atmospheric stability indicates the potential benefit and feasibility of wind plant control should be enhanced when the atmosphere is stable.

Description: Coastal flooding risks are becoming increasingly important because of the increasing vulnerability of coastal territories and the rise of ocean levels in relation to climate change. Studying the adaptation to these phenomena requires taking into account the coping strategies (problem-focused or emotional-focused coping) implemented by the inhabitants of the exposed territories. A theoretical model of situational and dispositional factors determining these strategies has been proposed and tested empirically with 583 inhabitants of the island of Guadeloupe, which is exposed to said coastal flooding risk. The fit index confirms the adequacy of the model. The results indicate that coastal flooding risk perception, difficulties to regulate emotions, and place attachment predict avoidance coping. Vigilant coping is only predicted by perceived action efficiency. The roles of duration of residence and distance from the sea have been highlighted.

Description: Currently, steam generation using solar energy mostly relies on optical concentration, which is a costly system, to generate the high temperature needed for water evaporation. Here, the development of a low-cost and scalable approach based on thermal concentration for solar steam generation is reported. The system was demonstrated to be capable of generating 100–120°C steam under ambient air conditions without optical concentration. A solar thermal efficiency could be achieved up to 13% at an average solar irradiance of only 670 W m−2. The new solar steam generation system, with its simple structure, great effectiveness, and low cost, holds the promise of significantly expanding the application domain of solar thermal systems.

Description: Hydraulic fracturing has been widely used in low permeability coalbed methane reservoirs to enhance gas production. To better evaluate the hydraulic fracturing curve and its effect on gas productivity, geological and engineering data of 265 development coalbed methane wells and 14 appraisal coalbed methane wells in the Zhengzhuang block were investigated. Based on the regional geologic research and statistical analysis, the microseismic monitoring results, in-situ stress parameters, and gas productivity were synthetically evaluated. The results show that hydraulic fracturing curves can be divided into four types (descending type, stable type, wavy type, and ascending type) according to the fracturing pressure and fracture morphology, and the distributions of different type curves have direct relationship with geological structure. The vertical in-situ stress is greater than the closure stress in the Zhengzhuang block, but there is anomaly in the aggregation areas of the wavy and ascending fracturing curves, which is the main reason for the development of multi-directional propagated fractures. The fracture azimuth is consistent with the regional maximum principle in-situ stress direction (NE–NEE direction). Furthermore, the 265 fracturing curves indicate that the coalbed methane wells owned descending, and stable-type fracturing curves possibly have better fracturing effect considering the propagation pressure gradient (FP) and instantaneous shut-in pressure (PISI). Two fracturing-productivity patterns are summarized according to 61 continuous production wells with different fracturing type and their plane distribution, which indicates that the fracturing effect of different fracturing curve follows the pattern: descending type 〉 stable type 〉 wavy type 〉 ascending type.

Description: The pore structure is an essential factor that influences the isothermal characteristics of methane adsorption of coal, and the pore structure is altered after methane adsorption. In this study, a high-rank coal sample was investigated via methane adsorption isothermal measurement, and changes in the pore structure were studied using low-pressure N2 adsorption and low-pressure CO2 adsorption before and after the methane adsorption. The excess adsorption capacity exhibits a rapid increase at low pressure, reaching a maximum when the test pressure is approximately 8 MPa. Following that, the excess adsorption capacity of the high-rank coal tends to decrease. After the methane adsorption, the pore volume and specific surface area of the micro-, meso-, and macropores increase as compared to those before the methane adsorption, especially for micropores with apertures greater than 0.8 nm and mesopores with apertures below 10 nm. This is mainly caused by high pressure in the methane adsorption, indicating a pressure effect on the pore structure after the methane adsorption. After the methane adsorption, the ratio of pores with various sizes in the high-rank coal is enhanced, but the connectivity for meso- and macropores presents a slight decrease.

Description: The pore-throat size determines the oil and gas occurrence and storage properties of sandstones and is a vital parameter to evaluate reservoir quality. Casting thin sections, field emission scanning electron microscopy, high-pressure mercury injection and rate-controlled mercury injection are used to qualitatively and quantitatively investigate the pore-throat structure characteristics of tight sandstone reservoirs of Xiaoheba Formation in the southeastern Sichuan Basin. The results show that the pore types include intergranular pores, intragranular dissolved pores, matrix pores, intercrystalline pores in clay minerals, and microfractures, and the pore-throat sizes range from the nanoscale to the microscale. The high-pressure mercury injection testing indicates that the pore-throat radius is in range of 0.004–11.017 µm, and the pore-throats with a radius 〉1 µm account for less than 15%. The rate-controlled mercury injection technique reveals that the tight sandstones with different physical properties have a similar pore size distribution (80–220 µm), but the throat radius and pore throat radius ratio distribution curves exhibit remarkable differences separately. The combination of the high-pressure mercury injection and rate-controlled mercury injection testing used in this work effectively reveals the total pore-throat size distribution in the Xiaoheba sandstones (0.004–260 µm). Moreover, the radius of the pore and the throat is respectively in range of 50–260 µm and 0.004–50 µm. The permeability of the tight sandstones is mostly affected by the small fraction (0.1 mD), the larger micropores and mesopores exert a great influence on the permeability. In contrast, the permeability is mainly influenced by the larger nanopores. Furthermore, the proportion of narrow pore-throats in tight sandstones increases with reducing permeability. Although the large number of narrow pore-throat (

Description: This analysis maps the key challenges posed by de-extinction to nature conservation law. The aim is to start a conversation about how such challenges should be framed and addressed if ongoing de-extinction projects in the United States of America (US) and the European Union (EU), the two jurisdictions examined, are successful. The analysis commences by providing a brief overview of existing debates in the conservation literature on the legal and ethical issues posed by de-extinction within the animal context. The article then proceeds to highlight two challenges animals created via de-extinction (de-extinctees) will likely pose for nature conservation law, namely: (1) to what extent taxonomies or definitions of ‘species’, and the methods for classifying these species under existing conservation frameworks, will be challenged by de-extinction; and (2) how existing conservation law frameworks in the US and the EU would likely apply to de-extinctees, and whether de-extinctees would be protected under these frameworks. It concludes by posing the broader question of whether and to what extent the law should facilitate de-extinction attempts in the same way that it has done for nature conservation.

Description: The full-scale fatigue test of rotor blades is an important and complex part of the development of new wind turbines. It is often done for certification according to the current IEC (2014) and DNV GL AS (2015) standards. Typically, a new blade design is tested by separate uniaxial fatigue tests in both main directions of the blade, i.e. flapwise and lead lag. These tests are time-consuming and rather expensive due to the high number of load cycles required, up to 5 million. Therefore, it is important to run the test as efficiently as possible. During fatigue testing, the rotor blade is excited at or near its resonant frequency. The trend for new rotor blade designs is toward longer blades, leading to a significant drop in their natural frequencies and a corresponding increase in test time. To reduce the total test time, a novel test method aims to combine the two consecutive uniaxial fatigue tests into one biaxial test. The biaxial test excites the blade in both directions at the same time and at the same frequency, resulting in an elliptical deflection path of the blade axis. Using elliptical loading, the counting of damage equivalent load cycles is simplified in comparison to biaxial tests with multiple frequencies. In addition, the maximum loads in both main directions remain separated, while off-axis loading is introduced. To achieve such a test, specific load elements need to be arranged so as to equalize the natural frequencies of the test setup for both test directions. This is accomplished by adding stiffness or inertial effects in a specific direction. This work describes a new method to design suitable test setups. A parameterized finite element (FE) model of the test with beam elements for the blade represents the test setup. A harmonic analysis on the FE model can identify the load distribution and the test conditions of a specific test setup within seconds. An optimization algorithm that varies parameters of the model and searches for the optimal setup is then applied to the analysis. This approach allows the efficient determination of a test setup, suited to the predefined requirements. The method is validated by applying it to three different test scenarios for a modern rotor blade: (a) state-of-the-art uniaxial setups, (b) uniaxial setups including springs and (c) a biaxial setup. In conclusion, the resulting setups are evaluated in terms of test quality and efficiency.

Description: Hydraulic fracture initiation and propagation are extremely important on deciding the production capacity and are crucial for oil and gas exploration and development. Based on a self-designed system, multi-perforation cluster-staged fracturing in thick tight sandstone reservoir was simulated in the laboratory. Moreover, the technology of staged fracturing during casing completion was achieved by using a preformed perforated wellbore. Three hydraulic fracturing methods, including single-perforation cluster fracturing, multi-perforation cluster conventional fracturing and multi-perforation cluster staged fracturing, were applied and studied, respectively. The results clearly indicate that the hydraulic fractures resulting from single-perforation cluster fracturing are relatively simple, which is difficult to form fracture network. In contrast, multi-perforation cluster-staged fracturing has more probability to produce complex fractures including major fracture and its branched fractures, especially in heterogeneous samples. Furthermore, the propagation direction of hydraulic fractures tends to change in heterogeneous samples, which is more likely to form a multi-directional hydraulic fracture network. The fracture area is greatly increased when the perforation cluster density increases in multi-perforation cluster conventional fracturing and multi-perforation cluster-staged fracturing. Moreover, higher perforation cluster densities and larger stage numbers are beneficial to hydraulic fracture initiation. The breakdown pressure in homogeneous samples is much higher than that in heterogeneous samples during hydraulic fracturing. In addition, the time of first fracture initiation has the trend that the shorter the initiation time is, the higher the breakdown pressure is. The results of this study provide meaningful suggestions for enhancing the production mechanism of multi-perforation cluster staged fracturing.

Description: Load calculations play a key role in determining the design loads of different wind turbine components. To obtain the aerodynamic loads for these calculations, the industry relies heavily on the Blade Element Momentum (BEM) theory. BEM methods use several engineering correction models to capture the aerodynamic phenomena present in Design Load Cases (DLCs) with turbulent wind. Because of this, BEM methods can overestimate aerodynamic loads under challenging conditions when compared to higher-order aerodynamic methods – such as the Lifting-Line Free Vortex Wake (LLFVW) method – leading to unnecessarily high design loads and component costs. In this paper, we give a quantitative answer to the question of load overestimation of a particular BEM implementation by comparing the results of aeroelastic load calculations done with the BEM-based OpenFAST code and the QBlade code, which uses a particular implementation of the LLFVW method. We compare extreme and fatigue load predictions from both codes using sixty-six 10 min load simulations of the Danish Technical University (DTU) 10 MW Reference Wind Turbine according to the IEC 61400-1 power production DLC group. Results from both codes show differences in fatigue and extreme load estimations for the considered sensors of the turbine. LLFVW simulations predict 9 % lower lifetime damage equivalent loads (DELs) for the out-of-plane blade root and the tower base fore–aft bending moments compared to BEM simulations. The results also show that lifetime DELs for the yaw-bearing tilt and yaw moments are 3 % and 4 % lower when calculated with the LLFVW code. An ultimate state analysis shows that extreme loads of the blade root out-of-plane bending moment predicted by the LLFVW simulations are 3 % lower than the moments predicted by BEM simulations. For the maximum tower base fore–aft bending moment, the LLFVW simulations predict an increase of 2 %. Further analysis reveals that there are two main contributors to these load differences. The first is the different way both codes treat the effect of the nonuniform wind field on the local blade aerodynamics. The second is the higher average aerodynamic torque in the LLFVW simulations. It influences the transition between operating modes of the controller and changes the aeroelastic behavior of the turbine, thus affecting the loads.

Description: In this study, the adsorption of Ni(II) and Cu(II) ions from aqueous solutions by powdered Delonix regia pods and leaves was investigated using batch adsorption techniques. The effects of operating conditions such as pH, contact time, adsorbent dosage, metal ion concentration and the presence of sodium ions interfering with the sorption process were investigated. The results obtained showed that equilibrium sorption was attained within 30 min of interaction, and an increase in the initial concentration of the adsorbate, pH and adsorbent dosage led to an increase in the amount of Ni(II) and Cu(II) ions adsorbed. The adsorption process followed the pseudo-second-order kinetic model for all metal ions' sorption. The equilibrium data fitted well with both the Langmuir and Freundlich isotherms; the monolayer adsorption capacity (Q0 mg g−1) of the Delonix regia pods and leaves was 5.88 and 5.77 mg g−1 for Ni(II) ions respectively and 9.12 and 9.01 mg g−1 for Cu(II) ions respectively. The efficiency of the powdered pods and leaves of Delonix regia with respect to the removal of Ni(II) and Cu(II) ions was greater than 80 %, except for the sorption of Ni(II) ions onto the leaves. The desorption study revealed that the percentage of metal ions recovered from the pods was higher than that recovered from the leaves at various nitric acid concentrations. This study proves that Delonix regia biomass, an agricultural waste product (“agro-waste”), could be used to remove Ni(II) and Cu(II) ions from aqueous solution.

Description: Scientific and industrial development has given rise to a rapidly increasing energy demand. Alternative and augmented energy resources are expected everywhere due to scarcity and depletion of other non-renewable resources. During recent years wind and solar had emerged as a promising cleaner energy source to offer a favourable solution with better efficiency. Hence, the attention has now diverted towards scaling up of hybrid system of energy generation. Numerous attempts have been taken to demonstrate the technological development concerning the requirement of the region. Whilst some research has already started to evaluate the working of the prototype, insignificant attention has been paid towards it. The current work also focuses on the simulation with hybrid urban renewable energy systems for techno-economic feasibility analysis. There were earlier attempts to report the advancement occurred in the technological, scientific and industrial sector due to hybrid renewable energy system. In some regard, it was an attempt to showcase the modelling of a typical urban requirement in an hourly load profile to identify in the energy potentials of the urban region. These will help to summarize the past, present and future trends of the hybrid energy system design, development and implementation for the urban region, which can be later on replicated to other parts of the world.

Description: Coordinated wind farm control takes the interaction between turbines into account and improves the performance of the overall wind farm. Accurate surrogate models are the key to model-based wind farm control. In this article a modifier adaptation approach is proposed to improve surrogate models. The approach exploits plant measurements to estimate and correct the mismatch between the surrogate model and the actual plant. Gaussian process regression, which is a probabilistic nonparametric modeling technique, is used in the identification of the plant–model mismatch. The efficacy of the approach is illustrated in several numerical case studies. Moreover, challenges in applying the approach to a real wind farm with a truly dynamic environment are discussed.

Description: Zeolites are important diagenetic minerals in petroleum reservoirs and have complex impacts on reservoir quality. To highlight this critical and challenging issue, we conduct a case study in the Middle Permian Lower-Wuerhe Formation in the Mahu Sag, Junggar Basin, China. Formation mechanism of zeolites and their impacts on the reservoir quality. Our results show that there are five types of zeolite minerals (i.e. laumontite, heulandite, analcime, stilbite, and clinoptilolite) in the Lower-Wuerhe Formation reservoir, with laumontite and heulandite being the main types. Petrographic and geochemical data suggested that laumontites developed in the Lower-Wuerhe Formation were mainly precipitated from pore water, whereas heulandites were formed associated with alteration of volcanic materials. In addition, the distribution of different type of zeolite minerals is generally controlled by sedimentary facies. The heulandite–laumontite zone developed mainly in the front of fan-delta plain, and the laumontite zone developed mainly in fan-delta front. The distal part of fan-delta front is dominated by albite. The zeolite mineral assemblages are generally controlled by geochemical composition of volcanic lithic fragments. The high content of intermediate-basic volcanic lithic fragments in the eastern Mahu Slope sediments is responsible for authigenic minerals such as heulandite, chlorite, and laumontite. However, the content of intermediate-basic volcanic lithic fragments in the western Mahu Slope sediments is low which results in the cement in this region is dominated by laumontite and mixed-layer illite/smectite. In general, conglomerates deposited in fan-delta front are favorable for the formation of early laumontite and late dissolution of laumontite due to resistance to compaction by coarse fraction and accumulation of acidic fluids in structural highs, which resulted in the formation of a high-quality reservoir. Our results have general implications for hydrocarbon exploration of the zeolite-bearing conglomerate reservoirs in non-marine petroliferous basins.

Description: The potential lifetime of wind turbine components is usually not fully utilized as the site conditions are less severe than assumed in the turbine design. Operators of wind farms can make use of the excess fatigue budget to increase the energy yield and thus decrease the levelized cost of energy (LCoE). To achieve this, the lifetime of the turbine can be extended until the fatigue budget is exhausted. Alternatively, a rotor blade extension (RBE) is an option to increase the energy yield of a wind turbine. An RBE increases the blade length and thus the swept area and the energy yield. An RBE also increases the loads on the turbine, however. Higher fatigue loads in turn reduce the fatigue budget of a turbine. This study investigates whether the use of an RBE is advantageous compared with a sole lifetime extension (LTE). As the use case, a commercial 1.5 MW turbine located in northern Germany was investigated. Aeroservoelastic multibody load simulations and simplified static load simulations were verified with each other. These simulations revealed the loads to determine the fatigue budget of the turbine components. Since the blade became the critical component when a certain RBE length was exceeded, the blade was subjected to a structural fatigue analysis. The fatigue analysis focused on the trailing-edge bond line which became critical when lead–lag loads increased with blade length. Finally, the energy production gains due to LTE and RBE were assessed. For the use case turbine, this study revealed an LTE of 8.7 years after a design life of 20 years with an additional energy yield of 43.5 %. Moreover, the extension of the 34 m blade with an RBE length of 0.8 m further increased the yield by 2.3 %.

Description: This paper deals with a new concept for the conversion of far-offshore wind energy into sustainable fuel. It relies on autonomously sailing energy ships and manned support tankers. Energy ships are wind-propelled. They generate electricity using water turbines attached underneath their hull. Since energy ships are not grid-connected, they include onboard power-to-X plants for storage of the produced energy. In the present work, the energy vector is methanol. The aim of the paper is to propose an energy ship design and to provide an estimate for its energy performance as function of the wind conditions. The energy performance assessment is based on a numerical model which is described in the paper. Results show that the wind energy-to-methanol (chemical energy) conversion efficiency is 24 % and that such an energy ship deployed in the North Atlantic Ocean could produce approximately 5 GWh per annum of chemical energy (900 t of methanol per annum).

Description: Coal fines produced during drainage of coalbed methane reservoirs can affect the permeability of the coal reservoir and damage production facilities such as downhole pumps, shafts, and valves. Thus, to clarify the mechanism of coal fines output is very important to high production of coalbed methane. The characteristics of coal fines can be used to identify the sources of the coal fines and to develop reasonable means of controlling coal fines output. In this study, different coal fines characteristics were investigated to reveal the output mechanism of coal fines. The coal fines samples were collected from 16 coalbed methane wells, which located in Eastern Ordos Basin of China. And the wells are in different drainage stages. The coal fines samples were analyzed by using transmission light microscopy, reflection polarized optical microscopy, laser particle size analysis, X-ray diffraction, and scanning electron microscopy with energy dispersive X. The results show that the concentration of coal fines is in the range of 3–8% (volume percent). The sizes of the coal fine particles tended to be below 200 µm. The main components of pulverized coal are vitrinite and inorganic minerals and the average content of inorganic minerals account for 50.56% and the standard deviation is 0.0685. The morphology analysis results show that the shape of coal fines is different in different parts of the coalbed methane wells. The coal fines concentration increases with the increase in the thickness of the deformed coal, and decreases with the increase in the burial depth. The concentration of coal fines becomes higher with the increase of casing pressure and coal fines concentration increases with the increase of the variation of bottom hole pressure.

Description: The real exchange rate is a key indicator of a country’s trade competitiveness in the world. This paper investigates the interaction between oil price and real exchange rates in Saudi Arabia during the period January 1986 -March 2019, using monthly data. This study uses the autoregressive distributed lag model and the error correction model in order to investigate the existence of a long-run equilibrium relationship between the variables. The evidence reveals that there is a strong long-run cointegration. The robustness of the autoregressive distributed lag bounds test cointegration was confirmed using the newly developed combined cointegration, which also provided the same evidence for a strong long-run relationship. In the short term, the results confirm the existence of a unidirectional causal relationship ranging from the oil price to the exchange rate. In the long term, however, the causal relationship is bidirectional between these two variables. An appreciation of the Saudi exchange rate generates an increase in the relative demand for oil, which in turn creates upward pressure on its price. For policy purposes, such evidence suggests that Saudi Arabia should be careful not to put too much weight on the benefits of higher revenue due to higher oil price.

Description: The first version of the actuator disc momentum theory is more than 100 years old. The extension towards very low rotational speeds with high torque for discs with a constant circulation became available only recently. This theory gives the performance data like the power coefficient and average velocity at the disc. Potential flow calculations have added flow properties like the distribution of this velocity. The present paper addresses the comparison of actuator discs representing propellers and wind turbines, with emphasis on the velocity at the disc. At a low rotational speed, propeller discs have an expanding wake while still energy is put into the wake. The high angular momentum of the wake, due to the high torque, creates a pressure deficit which is supplemented by the pressure added by the disc thrust. This results in a positive energy balance while the wake axial velocity has lowered. In the propeller and wind turbine flow regime the velocity at the disc is 0 for a certain minimum but non-zero rotational speed. At the disc, the distribution of the axial velocity component is non-uniform in all actuator disc flows. However, the distribution of the velocity in the plane containing the axis, the meridian plane, is practically uniform (deviation 5, almost uniform (deviation ≈2 %) for wind turbine disc flows with λ=1 and propeller flows with advance ratio J=π, and non-uniform (deviation 5 %) for the propeller disc flow with wake expansion at J=2π. These differences in uniformity are caused by the different strengths of the singularity in the wake boundary vorticity strength at its leading edge.

Description: The ventilator of the heating tower and the circulating pump of the anti-freeze solution are the main electrical equipment of a heating tower heat pump system, besides the compressor. By controlling the working frequencies of the ventilator of the heating tower and circulating pump of the anti-freeze solution, the effects of the operation parameters of a closed-type heating tower on its heat absorption and the performance of heating tower heat pump system were investigated under winter heat conditions. The results indicated that reducing the frequency of the circulating pump for the anti-freeze solution leads to a decrease in the temperature of the outlet evaporator of the anti-freezing solution and an increased temperature difference between the anti-freeze solution flowing into and out of the heating tower; meanwhile, excessively high and low anti-freeze flow rates lead to reduced heat absorption of the closed-type heating tower. The coefficient of performance fluctuates slightly if the frequency of circulating pump is above 20 Hz, but a slight drop in coefficient of performance is observed when the frequency is less than 15 Hz. The system energy efficiency ratio tends to increase as the frequency of circulating pump is reduced, although a substantial reduction occurs at 10 Hz. Furthermore, a reduced ventilator frequency decreases the temperatures of the anti-freeze solution at the inlet and outlet of the heating tower and the temperature difference, hindering the heat absorption of the heating tower. With reductions in the ventilator frequency, the coefficient of performance exhibits an initial increase followed by subsequent decreases, while the system energy efficiency ratio showed continual increases until the ventilator frequency dropped to 10 Hz. When the ventilator frequency or circulating pump frequency drops to 15 Hz and 10 Hz, the evaporation temperature of the heat pump unit decreases, resulting in an excessively exhaust temperature, which is not favorable for the safe operation of the system.