Green Beds Research Articles

Citizens' preferences and valuation of urban nature: Insights from two choice experiments

Urban nature increases the liveability of cities and can improve their resilience to climate change. However, the value of urban nature often remains unknown, which results in its omission from urban planning decisions. Particularly the valuation of small-sized urban nature remains understudied. This study therefore employs a stated preference methodology to estimate the economic value of seven types of small urban nature and four associated ecosystem services. We perform two choice experiments: one with urban parks, urban forest and green corridors and another one with even smaller urban nature types (green roofs, green walls, street trees and green beds). The results of the choice analysis show that urban residents are willing to pay more for the former types of urban nature but not for the latter types. Urban parks are valued the most, followed by urban forests and green corridors. Within the category of the smallest urban nature types, street trees are valued most followed by green beds, whereas green walls and green roofs are least valued. We discuss opportunities and barriers to implementing economic valuation results in urban planning practices. Several policy and future research recommendations are proposed.

Particle classification of iron ore sinter green bed mixtures by 3D X-ray microcomputed tomography and machine learning

Particle classification of iron ore sinter green bed mixtures by 3D X-ray microcomputed tomography and machine learning

Surveying soil-borne disease development on wild rocket salad crop by proximal sensing based on high-resolution hyperspectral features

Wild rocket (Diplotaxis tenuifolia, Brassicaceae) is a baby-leaf vegetable crop of high economic interest, used in ready-to-eat minimally processed salads, with an appreciated taste and nutraceutical features. Disease management is key to achieving the sustainability of the entire production chain in intensive systems, where synthetic fungicides are limited or not permitted. In this context, soil-borne pathologies, much feared by growers, are becoming a real emergency. Digital screening of green beds can be implemented in order to optimize the use of sustainable means. The current study used a high-resolution hyperspectral array (spectroscopy at 350–2500 nm) to attempt to follow the progression of symptoms of Rhizoctonia, Sclerotinia, and Sclerotium disease across four different severity levels. A Random Forest machine learning model reduced dimensions of the training big dataset allowing to compute de novo vegetation indices specifically informative about canopy decay caused by all basal pathogenic attacks. Their transferability was also tested on the canopy dataset, which was useful for assessing the health status of wild rocket plants. Indeed, the progression of symptoms associated with soil-borne pathogens is closely related to the reduction of leaf absorbance of the canopy in certain ranges of visible and shortwave infrared spectral regions sensitive to reduction of chlorophyll and other pigments as well as to modifications of water content and turgor.

Mineralogy, geochemistry, and genesis of glauconite mineral from paleotsunami deposit in Lebak, Banten, Indonesia

Bagedur coast in Lebak regency, Banten province, Indonesia is part of lowland-swampy swale area that consist of various sediment deposit. Based on its sediment characteristics and geomorphology profile, Bagedur coast is assumed as depositional environment of paleotsunami deposit. Hand Auger drilling method is used to collecting loose sediment sample from eight observation stations. The depth of hand drilling in BG 01 station to BG 08 station is consecutively as follows: 115 cm, 100 cm, 80 cm, 700 cm, 400 cm, 450 cm, 160 cm, and 143 cm. This research is carried out to understand the diagenetic process of glauconite mineral in presumption paleotsunami deposit. The diagenetic process of glauconite mineral is identified based on its mineralogical and geochemical characteristics by petrography and X-Ray Fluorescence (XRF) methods. Observation samples is taken from green sand sediment bed in hand drilling core. Petrographic analysis under polarized microscope shows various glauconite mineral which recognized as matrix, oval pellets, replacement of precursor mineral, and bioclastic shell infillings. XRF analysis result show that glauconite in observation site are classified as glauconitic-illite type. The diagenetic stage is interpreted as early stage of diagenetic (nascent) which characterized by low Fe2O3 and K2O content relative to Al2O3 content.

Experimental investigation on the effect of granulation moisture on the flame front propagation and pore structure in the high-temperature zone of the sinter bed

The pore structure in the high-temperature zone plays a leading role in the permeability of the sinter bed. However, few studies on the bed structure in the high-temperature zone of sintering are due to the difficulty of sampling. Pilot-scale sinter pot tests were conducted to investigate the flame front propagation properties and pore evolution characteristics under different granulation moisture in this paper. Liquid nitrogen was injected to quench the sintering bed. We use X-ray computed tomography to reconstruct the high-temperature zone sinter structures. Results show that the higher porosity of green bed under higher granulation moisture results in faster flame front and more likely channels formation. The porosity of the high-temperature zone increases from 48.40% to 51.50% and 55.68% with moisture increasing from 5.30% to 6.35% and 6.91%. However, the mean length of pores decreases from 1.60 mm to 1.38 mm caused by inadequate coalesce under high moisture conditions.

Influence of quick lime on pore characteristics of high-temperature zone in iron ore sinter based on XCT technology

The pore structure of the bed has an important influence on the heat transfer and permeability characteristics in the iron ore sintering process. In this study, liquid nitrogen was applied to quench the high-temperature zone sinter to reproduce the original porous structure to the maximum extent. The effect of quick lime on pore characteristics of the high-temperature zone in the iron ore sinter was studied. XCT technology was applied to scan the sinter, and the model of solid phase, pore, and closed pore was reconstructed. The equivalent spherical diameter of the pore and its distribution frequency, volume fraction, sphericity, and surface porosity were statistically analyzed. The results indicate that the addition of quick lime increases the permeability of the green bed and shortens the sintering time. Meanwhile, it promotes the flow of the molten liquid phase, resulting in the bubble aggregation more fully. With the increase of the addition of quick lime, the porosity of the sinter decreases gradually. Finally, the pore skeleton model was established, and the pore skeleton parameters were statistically analyzed. With the increase of quick lime, the total pore volume and total pore length, the number of pore segments, branching nodes and terminal nodes all decrease.

Energy-saving rating of green Bed and Breakfast based on the fuzzy comprehensive evaluation

Formulating a reasonable energy-saving strategy for Bed and Breakfast (B&B) can effectively reduce the operating costs, increase the revenue and achieve sustainable development. Given this background, a fuzzy evaluation-based energy-saving rating method for B&B is proposed in this paper. Four energy-saving indexes are determined for different loads of B&B. Then the weighting method of the indexes based on deviation degree is presented. Finally, the energy-saving rating method of B&B based on the principle of maximum membership is proposed. A case study of B&B in Anji, China is employed to demonstrate the proposed rating method. This case analyzes and determines the overall energy-saving grade and weakness of the B&B. The result shows that the rating method proposed is more theoretical and the rating result is more reasonable and comprehensive.

Evaluation of granule structure and strength properties of green packed beds in iron ore sintering using high-resolution X-ray tomography and uniaxial compression testing

The strength properties of green sinter beds, including the Young’s modulus and maximum bed strain, were evaluated using uniaxial compression tests. The green-sinter-bed samples were scanned using X-ray computed tomography (XCT), and the geometry characteristics of the granules were quantified by XCT image analysis. The orthogonal array method was applied to determine the concomitant effects of the moisture, hydrated lime, and concentrate contents on the bed strength characteristics. Less bed strain was observed when the granules had a thin adhering layer and increased interlock contacts, which had a great capacity to resist the applied load collectively. The optimal combination for decreasing the bed maximum strain was 5.8% moisture, 2% hydrated lime, and 0% concentrate. The moisture and concentrate contents were the most significant factors determining the green bed strength. Increasing the moisture and concentrate contents produced granules with a thicker and more deformable adhering layer, resulting in a more compact bed. The addition of hydrated lime inhibited rearrangement, deformation, and fracture of the granules in green sinter bed during compression.

Flame front propagation and sinter strength properties of permeable sintering bed prepared via enhanced granulation with hydrated lime

AbstractThis paper is focused on investigating the influences of enhanced granulation with hydrated lime on the propagation of flame front and strength properties of the produced sinter in iron ore sintering. Pilot‐scale sinter pot experiments were performed at three hydrated lime levels, and the porous structures of sinter were reconstructed by high resolution X‐ray tomography. When hydrated lime increased from 0% to 2%, more permeable green bed with enlarged granule mean size and narrowed granule size distribution could be obtained, and sinter productivity increased from 37.3 to 40.7 t/m2/d while tumbler index of sinter decreased from 62.7% to 55.0%. Both the bed temperature and pressure profiles verified that hydrated lime addition fasten sintering by reduction of heat accumulation and acceleration of flame front speed in sintering bed. The three‐dimensional stress analysis based on the actual microstructures showed that more irregular sinter particles with higher porosity are obtained with higher hydrated lime due to the insufficient melt formation and coalescence during sintering. Sinter with 2% hydrated lime was much more compliant under the fixed compression, exhibiting larger potential to be deformed in locations including bridges with the small cross sections and notches with the small fillet radius.

Evaluating the permeability properties of green bed in iron ore sintering using high resolution X-ray computed tomography and orthogonal array tests

This study reconstructed porous structure and numerically evaluated permeability properties over several green sinter bed samples by applying X-ray computed tomography (XCT) and orthogonal array tests together. Contributions of three factors including moisture, hydrated lime and magnetite concentrate on experimental Japanese Permeability Units value and XCT-simulated absolute permeability coefficient were analyzed and compared. Results portray that pore network model is helpful to extract the pore distribution and topology in green sinter bed, the observed increase in green bed permeability is attributed to the increase of pore radius, throat radius and throat length, rather than tortuosity. The optimum combination for improving green bed permeability is 7.8% moisture, 4% hydrated lime and 0% concentrate. Moisture and hydrated lime factors are the more effective parameters on bed permeability while concentrate factor is insignificant, since those binders have different mechanisms in determining the outcome granule size distribution and strength, resulting in various pore properties.

Harmless treatment of waste selective catalytic reduction catalysts during iron ore sintering process

A substantial quantity of waste selective catalytic reduction (SCR) catalysts is produced as hazardous wastes owing to the ultra-low emission reform of coal-fired power plants. This study aims to propose a new method for large-scale harmless treatment of waste SCR catalysts for utilization during iron ore sintering process. The effects of adding waste SCR catalysts on green bed permeability, flame front propagation, mineral phase, microstructure, and sinter indexes were evaluated. Results showed that the addition of waste SCR catalysts decreased the concentrated distribution degree of granules and deteriorated green bed permeability, thereby leading to slower propagation of flame front and lower sintering bed temperature. Results of mineral phase and microstructural analysis revealed that less calcium ferrite and more skeletal hematite formed, and porosity decreased from 39.64% to 24.62% when the level of waste SCR catalysts added was increased from 0 to 10%. All sinter indexes, including flame front speed, productivity, yield, and tumbler index, decreased with the increase in the level of waste SCR catalysts added. A comprehensive index was adopted to systematically evaluate the influence of adding waste SCR catalysts. This index decreased from 100.0 to 2.9 as the level of waste SCR catalysts added was increased from 0 to 10%. Finally, the addition of 2% waste SCR catalysts is recommended to achieve high sinter quality.

Improvement in the permeability of sintering beds by drying treatment after granulating sinter raw materials containing concentrates

The permeability of the sinter green beds will remarkably deteriorate when magnetite concentrate powder is introduced into the raw blend. To address this problem, a technique of drying after high-moisture granulation is proposed. Using this technique, the permeability can be raised from 40.45 JPU to 46.05 JPU at 7.7 wt% granulation moisture. At the same time, the results show that drying may cause the degradation of granules when the granulation moisture is excessive. Therefore, the final permeability of the stacked bed depends on the combined effect of increasing the bed stiffness and decreasing the average particle size. Fortunately, the addition of hydrated lime (HL) can significantly inhibit granule degradation and improve granulation efficiency, which can further improve the bed permeability to 61.41 JPU with a 2% HL addition level (at 7.7 wt% granulation moisture). Finally, an optimized process is proposed that uses low-grade waste heat during sinter cooling to dry the wet granules. This optimization not only meets the energy needs of drying but also facilitates the grade recovery and cascade utilization of waste heat during the sintering process.

DEM study on size segregation and voidage distribution in green bed formed on iron ore sinter strand

The size segregation and voidage distribution down a green bed formed on an iron ore sinter strand were investigated experimentally and using Discrete Element Method (DEM). The simulated and experimental results showed that an increase in feed rate (from 6 kg/s/m to 18 kg/s/m) significantly decreased the level of vertical size segregation and the granule packing voidage of each bed sub-layer. With the increase in rill plate angle (from 45° to 65°), the level of vertical size segregation first decreased and, then, remained relatively constant. Furthermore, the results indicated that the voidage of each bed sub-layer generally increased with the increase in λ. In conclusion, enhancing the vertical size segregation down the green bed can generally improve the voidage of the green bed and thus increase the bed permeability.

Organic signatures in Pleistocene cherts from Lake Magadi (Kenya) – implications for early Earth hydrothermal deposits

Abstract. Organic matter in Archean hydrothermal cherts may provide an important archive for molecular traces of the earliest life on Earth. The geobiological interpretation of this archive, however, requires a sound understanding of organic matter preservation and alteration in hydrothermal systems. Here we report on organic matter (including molecular biosignatures) enclosed in hydrothermally influenced cherts of the Pleistocene Lake Magadi (Kenya; High Magadi Beds and Green Beds). The Magadi cherts contain low organic carbon (< 0.4 wt %) that occurs in the form of finely dispersed clots, layers, or encapsulated within microscopic carbonate rhombs. Both extractable (bitumen) and non-extractable organic matter (kerogen) were analyzed. The bitumens contain immature “biolipids” like glycerol mono- and diethers (e.g., archaeol and extended archaeol), fatty acids, and alcohols indicative for, inter alia, thermophilic cyanobacteria, sulfate reducers, and haloarchaea. However, co-occurring “geolipids” such as n-alkanes, hopanes, and polycyclic aromatic hydrocarbons (PAHs) indicate that a fraction of the bitumen has been thermally altered to early or peak oil window maturity. This more mature fraction likely originated from defunctionalization of dissolved organic matter and/or hydrothermal petroleum formation at places of higher thermal flux. Like the bitumens, the kerogens also show variations in thermal maturities, which can partly be explained by admixture of thermally pre-altered macromolecules. However, findings of archaea-derived isoprenoid moieties (C20 and C25 chains) in kerogen pyrolysates indicate rapid sequestration of some archaeal lipids into kerogen while hydrothermal alteration was active. We posit that such early sequestration may enhance the resistance of molecular biosignatures against in situ hydrothermal and post-depositional alteration. Furthermore, the co-occurrence of organic matter with different thermal maturities in the Lake Magadi cherts suggests that similar findings in Archean hydrothermal deposits could partly reflect original environmental conditions and not exclusively post-depositional overprint or contamination. Our results support the view that kerogen in Archean hydrothermal cherts may contain important information on early life. Our study also highlights the suitability of Lake Magadi as an analog system for hydrothermal chert environments on the Archean Earth.

Prediction of breakthrough curves in packed-bed column as tool for lysozyme isolation using a green bed

Fil: Brassesco, Maria Emilia. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Rosario. Instituto de Procesos Biotecnologicos y Quimicos Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquimicas y Farmaceuticas. Instituto de Procesos Biotecnologicos y Quimicos Rosario; Argentina

LOWER TRIASSIC (INDUAN TO OLENEKIAN) CONODONTS, FORAMINIFERA AND BIVALVES FROM THE AL MAMALIH AREA, DEAD SEA, JORDAN: CONSTRAINTS ON THE P-T BOUNDARY

Upper Permian to Lower Triassic successions exposed in the Al Mamalih area, east of the Dead Sea, Jordan record the transition between the alluvial Umm Irna Formation (Upper Permian) and the overlying shallow marine Ma’in Formation (Lower Triassic). The Permian-Triassic boundary is constrained either within a hiatus represented by a sequence boundary between these formations or within ca 15 m of shallow marine beds overlying the boundary. Above the sequence boundary reddened, shallow-marine beds (Himara Member) mark the initial Triassic (presumed early Induan) marine transgression (Himara Member). Absence of both body fossils and vertical infaunal burrows indicates low-diversity, ecosystems following the Permian-Triassic extinction event. A gradational upward increase in grey, green and yellow siltstones beds (Nimra Member), accompanied by a concomitant increase in bioturbation (surface traces and infaunal vertical burrows), bivalves and brachiopods, stromatolites, conchostracans and lingulids in the lower part of the Nimra Member indicates colonisation of the substrate under shallow marine conditions during the recovery phase. Shallow-water carbonates in the Nimra Member yielded an abundant, low diversity assemblage of conodonts (e.g. Hd. aequabilis and H. agordina) and a foraminifera assemblage (Postcladella gr. kalhori-Earlandia spp.-Ammodiscus jordanensis n. sp.) that are interpreted as euryhaline recovery taxa that characterise the the mid-late Induan. Abundant new material has allowed revision of the conodont apparatus and the foraminifera include a new species Ammodiscus jordanensis n. sp. of Induan age. The discovery of the bivalves Claraia bittneri (C. aurita group) and Eumorphotis multiformis is worthy to note. Upper Permian alluvial lithofacies (Jordan) pass basinwards, about 50 km to the northwest, to coeval shallow marine siliciclastic and carbonates in the Negev and Mediterranean coast of Israel.

Experimental investigation on the flame front resistance of gas channel growth with melt formation in iron ore sinter beds

The resistance of the flame front within the solid bed constitutes a fundamental and crucial area in porous bed combustion as the flame front propagation is highly related to the productivity and product quality. This paper focuses on the iron ore sintering, a thermal agglomeration process in steel mills. The results from a detailed experimental study of the pilot-scale pot tests under the conditions of a wide range of fuel rate are presented. The primary objective is to provide better understanding of the growth of gas channels relating to melt formation in the flame front and its resistance to flow. The sintering bed was divided into several zones based on the temperature profile and component distribution. Even though there is a continuous one-to-one replacement of humidified zone with porous sintered zone, a constant air flow rate during sintering could be obtained, indicating the ∼100 mm high-temperature zone has a controlling effect on sintering bed permeability. The specific pressure drop value in high-temperature zone increases from ∼3 kPa in upper bed to ∼7 kPa in bottom bed, which varies with the bed temperature and structure properties. Both the green bed and sintered bed were scanned by X-ray computed tomography, the reconstruction and image analysis showed that the sintered bed has large gas channels and many more closed pores due to solid-melt-gas coalescence. More melt is generated when the heat is accumulated along the bed or input higher coke content, showing a propensity to suppress the gas channel growth and amplify the mismatch of gas transportation along the bed. Higher coke rate leads to a higher resistance in flame front, resulting in a slower flame front speed. These results are aimed to provide quantitative validation for improvements of a numerical sintering model in a future work.

Evaluation of compressive strength and shear strength of the adhering layer of granules in iron ore sintering

A thorough understanding of the mechanical properties of the adhering layer of iron ore granules is necessary to optimize green bed permeability and improve sinter plant productivity. With this in mind, tablets simulating the granule adhering layer were manufactured using proportions of components in each size range based on Litster’s granulation model. Uniaxial compression tests and direct shear tests were performed to characterize the compression and shear strength of the simulated tablets respectively. A variety of granulation conditions including moisture levels, hydrated lime addition levels as well as magnetite concentrate substitution levels were tested. The results of compression tests show that the granule adhering layer becomes more compliant and weaker with the increase of concentrate substitution level due to the increased spread in the size distribution of the embedded particles. In direct shear tests, hydrated lime addition could improve the cohesion constant from ~1kPa to ~3kPa for the base blend, but the extent of this improvement decreased when more concentrate was added to the blend. When micro-particles such as hydrated lime and concentrate particles are introduced into the blend, the mechanical response of the granule adhering layer becomes much more complex. The hydrated lime could act as solid binder and increase the strength of granule adhering layer while the concentrate plays an opposite role and deteriorates the adhering layer strength. The internal friction angle of the adhering layer in direct shear tests ranges from 30°to 38°and could somehow represents the resistance to deformation during packing. Combining the friction angle data with the previous granulation and packing results, a more mechanistic model of green bed voidage ε=ε0+tanϕΔdp1−ε0exp−R−n was proposed, in which the term representing the extent of deformation in the adhering layer was given a more reasonable physical explanation.

Towards green experiential loyalty

PurposeThis paper aims to test the relationships among the experiential quality dimensions, the green relationship quality dimensions, environmental friendliness, green support, green desire and green experiential loyalty in a green bed & breakfast (B&B) context.Design/methodology/approachThe data used in this study are based on a sample of 517 customers staying at one green B&B in Yilan County of Taiwan. The predicted relationship is tested using structural equation modeling.FindingsThe empirical findings reveal the following: five dimensions (peer-to-peer quality, physical environment quality, outcome quality, venue quality and administration quality) constitute a multidimensional model to conceptualize and measure perceived experiential quality that can achieve green experiential satisfaction in addition to environmental friendliness; environmental friendliness has a direct influence on green trust and green experiential satisfaction, which has a positive significant influence on green support and green desire; and green trust, green experiential satisfaction and green support contribute to green experiential loyalty.Practical implicationsTo increase the perceptions of experiential quality dimensions, green relationship quality dimensions, environmental friendliness, green support, green desire and green experiential loyalty, the findings of this study will help green B&B management develop and implement market-orientated service strategies.Originality/valueThis paper provides data that result in a better understanding of the relationships among experiential quality dimensions, green relationship quality dimensions, environmental friendliness, green support, green desire and green experiential loyalty in a green B&B setting.

198Red and Green Bed Day Patient Flow System in an Acute Geriatric Medicine Unit

198Red and Green Bed Day Patient Flow System in an Acute Geriatric Medicine Unit