14,641 results on '"mud"'
Search Results
2. Aquifer characterization using the geoelectric method.
- Author
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Harimei, Bambang, Syamsuddin, Syamsuddin, Syahtrimulyani, Maria, Maria, and Makhrani, Makhrani
- Subjects
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MUD , *CLAY , *SOILS , *AQUIFERS - Abstract
The research has been carried out on aquifer characteristics using the geoelectric method. The results obtained are as follows; the aquifer at the study site is shallow and interconnected deep aquifers. Look at the 2D geoelectric cross section and the correlation between survey points in 3D space; there is an aquifer system. The aquifer is unconfined and confined. The depth of the unpressured aquifer ranges from 6.38 – 9.26 meters BMT (below the local soil surface) at the top or surface, dominated by clay, this mud covers most of the shallow aquifer layer. The unconfined aquifer is at depressed aquifer depth >12.4 meters BMT. The aquifer at the study site is at a depth from 1.25 meters to 9.26 meters (the deepest measurement penetration) and is a continuous aquifer from the surface and fills the inner aquifer. [ABSTRACT FROM AUTHOR]
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- 2024
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3. Ancient Babylon city site monitoring using PSInSAR.
- Author
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Jaafar, Hasan A.
- Subjects
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SYNTHETIC aperture radar , *TENSILE strength , *BRITTLENESS , *MUD , *DENSITY - Abstract
The Ancient Babylon City has been included in the World Heritage List during the (43) session of the World Heritage Committee (Baku / Azerbaijan) 2019. Babylon site suffers from the consequences of ground instability due to the unbaked mud brick's, employed to build the whole city, low tensile strength and brittleness particularly at the foundation level. Hence, it is suggested to employ Persistent Scatterers Interferometric Synthetic Aperture Radar (PSInSAR) as a monitoring method that can offer a survey for the whole site (1208.8 hectare) in order to conduct, in the second stage, an in-situ detailed monitoring survey. However, there are some limitations of applying PSInSAR in a limited area, a few square km such as the Ancient Babylon city, because it may produce a limited PS density or cannot give solutions at all. To overcome such issue, it is proposed, in this research, to separate processing for different years and summing the outcomes of the processing up mathematically. The results of the proposed method show improvement in the PS density and agree with the deformation locations compared to general PSInSAR. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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4. Effects of 2 wintering practices on behavioral and physiological indicators of welfare of nonlactating, pregnant dairy cattle in a pasture-based system.
- Author
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Schütz, K.E., Latimer, B., McDonald, N., Hunter, L.B., Huddart, F.J., Watson, T., Saunders, L.-R., Kells, N.J., Cox, N.R., and Monaghan, R.M.
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FREE fatty acids , *LEUCOCYTES , *ERYTHROCYTES , *ANIMAL welfare , *THERMAL comfort , *COLE crops , *PASTURE management - Abstract
The list of standard abbreviations for JDS is available at adsa.org/jds-abbreviations-24. Nonstandard abbreviations are available in the Notes. In countries with pasture-based dairy systems and relatively cold winters, such as New Zealand, it is common to manage pregnant, nonlactating cows on forage crop paddocks rather than pasture, due to slow pasture growth rates. Wintering dairy cattle on grazed crops can compromise welfare if wet and muddy underfoot conditions occur, which can reduce lying. This study investigated behavioral and physiological indicators of welfare of cows under 2 wintering practices: cows managed on and grazed kale crop (Brassica oleracea), and cows managed on pasture with baled hay. Following dry-off (d 0), 80 cows were randomly assigned to 1 of the 2 wintering practices (40 cows/practice) and monitored between d 4 and 32 (phase 1). During this period, lying and stepping behavior was continuously recorded using leg-based accelerometers. Blood samples were obtained at d 0 and 32 for measurements of thyroxine (T4), nonesterified fatty acids (NEFA), white blood cells (WBC), and red blood cells. All data for phase 1 were presented descriptively due to the lack of treatment replication. Daily mean air temperature during this period was 5.2°C (range: 0.0–10.7°C), and rainfall was 1.1 mm/d (range: 0–5.6mm/d). Between d 4 and 32, cows in both groups spent similar amounts of time lying (pasture with hay cows: 8.9 h/24 h ± 2.57, kale crop cows: 8.7 h/24 h ± 3.06, mean ± SEM). Both groups reduced their lying on wet and cold days, and there was evidence of rebound lying once unfavorable weather conditions stopped. Cows on kale crop had numerically higher NEFA and lower WBC compared with cows managed on pasture, although most physiological values were within normal ranges. In a second phase of the study (d 34 and 35), cows were managed under controlled, replicated conditions in the 2 wintering practices using typical on-farm stocking rates (2 or 4 cows per group in the pasture with hay and kale crop treatments, respectively; n = 10 groups/treatment). During this period, cow behavior, skin and surface temperatures, hygiene scores, feed intakes, and ground conditions were measured. Weather conditions during the 48-h exposure were mostly cold and dry (mean air temperature: 7.8°C, range: −2.2 to 20.5°C). Cows managed on pasture with hay spent more time lying down on the first day of exposure; however, this was likely due to less space being available to kale cows on this day. Cows managed on pasture with hay ruminated more than cows on kale crop on both days of observations (d 1: 37.9% vs. 30.9% of observations, d 2: 36.8% vs. 28.7% of observations for pasture with hay and kale crop groups, respectively) and were lying more often in postures indicative of greater thermal comfort. Cows managed on pasture with hay had higher skin and surface temperatures compared with cows on kale crop, whereas cows on kale crop had dirtier coats. Results suggest that opportunities for thermal comfort were greater for cows managed on pasture with hay bales, which may be due to increased rumination activities and more insulated lying areas. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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5. Levels of engagement among office‐based opioid treatment (OBOT) patients with concurrent methamphetamine use.
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Coules, Courtney L., Novotny, Clara B., McDonough, Margaret E., and Kopak, Albert M.
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OPIOID abuse , *MEDICAL offices , *METHAMPHETAMINE , *MUD , *REGRESSION analysis - Abstract
Background and Objectives: Recent increases in methamphetamine use among people seeking treatment for opioid use disorder (OUD) has created significant demand for effective approaches to support this clinical population. This study assessed the extent to which office‐based opioid treatment (OBOT) patients, who were diagnosed with methamphetamine use disorder (MUD), engaged with providers. Methods: A retrospective analysis was conducted of adult patients (n = 470) seeking treatment for OUD who attended at least one visit between March 2020 and March 2023 at a rural regional OBOT provider. Approximately one quarter (28.7%) of patients were diagnosed with MUD in addition to receiving an OUD diagnosis. Bivariate methods and multivariate negative binomial regression models were estimated to examine the associations between clinical measures and the numbers of office visits, peer visits, and telehealth visits. Results: Regression results indicated patients who met criteria for MUD in addition to OUD attended a higher rate of peer visits (incidence rate ratio [IRR] = 2.63, p =.036) when compared to patients who did not meet criteria for MUD. In contrast, patients with MUD and OUD diagnoses displayed significantly lower (IRR = 0.68, p <.001) engagement rates through fewer office visits relative to those who did not meet MUD criteria. Discussion and Conclusions: Patients seeking treatment for OUD who meet criteria for MUD are more likely to engage through peer support specialists rather than office visits. Scientific Significance: This study demonstrates the ways patients who meet criteria for OUD and MUD engage with providers to receive treatment. [ABSTRACT FROM AUTHOR]
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- 2024
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6. The Effect of Sediment Mud Content on Primary Production in Seagrass and Unvegetated Intertidal Flats.
- Author
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Flowers, Georgina J. L., Needham, Hazel R., Bulmer, Richard H., Lohrer, Andrew M., and Pilditch, Conrad A.
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MUD ,ESTUARINE sediments ,EFFECT of human beings on climate change ,SEAGRASSES ,PRODUCTION losses ,NUCLEAR power plants - Abstract
As a consequence of anthropogenic activities and climate change, accelerated terrestrial sediment runoff is causing the gradual mudification of soft sediment estuarine habitats worldwide. Increased sediment mud content (< 63 µm) has been recognised to alter seagrass morphology and cause declines in primary production in unvegetated habitats. However, the effect of increased mud content on primary production in seagrass meadows remains largely unknown. To address this, primary production in intertidal seagrass meadows (Zostera muelleri) and adjacent unvegetated habitats was measured in situ using benthic incubation chambers across an existing sedimentary gradient (nine sites spanning 5–33% mud content). An additional two unvegetated mudflat sites (39–49% mud content) were also sampled to expand the gradient. Seagrass net (NPP) and gross primary production (GPP) was greater than in the adjacent unvegetated habitat and did not vary with mud content, even after standardising GPP by photosynthesising biomass (i.e. photosynthetic efficiency). In contrast, in the adjacent unvegetated habitat, photosynthetic efficiency declined with increasing mud content. Inclusion of the additional mudflat sites negatively impacted NPP, GPP, and photosynthetic efficiency in the unvegetated habitat. Thus, while primary production in seagrass meadows may have some resilience to future increases in mud content (up to ~33%), further degradation and loss of seagrass habitats could result in the expansion of unvegetated habitats and ultimately lead to production losses, likely to be most acute in areas with high mud content (≥ 39%). [ABSTRACT FROM AUTHOR]
- Published
- 2024
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7. Enhanced mud retention as an autogenic mechanism for sustained delta growth: Insight from records of the Lafourche subdelta of the Mississippi River.
- Author
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Kim, Minsik, Chun, Byongsuk, Chamberlain, Elizabeth, and Kim, Wonsuck
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RF values (Chromatography) , *MUD , *FLOODPLAINS , *COMPACTING , *PLAINS - Abstract
ABSTRACT Mud deposition is acknowledged as a significant contributor to delta architecture, yet its role is often oversimplified as a constant parameter in models of delta formation. A better understanding of mud retention on deltas would resolve remaining questions regarding delta growth. This study explores how spatiotemporally varied mud retention facilitates sustained delta growth in defiance of the concept of autoretreat, that is, the idea that shoreline progradation rates decline as a delta grows due to the expansion of subaqueous and subaerial delta surfaces. This research is inspired by prior field observations of the river‐dominated Mississippi Delta, USA, where the shoreline of a ca 6000 to 8000 km2 subdelta prograded at a constant rate for roughly a millennium, despite its expanding delta surface, compaction and sea‐level rise. For this, a laterally averaged one‐dimensional numerical model is leveraged to test hypotheses that enhanced mud retention with time in: (i) the delta bottomset; and (ii) the delta plain (floodplain) supports a constant rate of shoreline progradation in a maturing delta. Results demonstrate that enhanced mud retention in both the bottomset and delta plain facilitates sustained delta growth. Neither component by itself can replicate the case study. Yet, with these two integrated components, the model reproduces the cross‐section and linearly prograding pattern observed in the Mississippi Delta. The findings provide an autogenic mechanism for sustained delta growth and support the importance of mud as a fundamental building block of deltas that should be incorporated in delta‐growth models of engineered river diversions. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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- View/download PDF
8. Study on the strength characteristics and micro-mechanism of modified solidified red mud.
- Author
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Ziyi Ding, Yu Cheng, Lu Jin, Wentong Wang, and Shiying Yan
- Subjects
GARNET ,MUD ,GOETHITE ,FLY ash ,CALCIUM aluminate ,SOLID waste ,MICROSCOPY - Abstract
The residue generated during the production process of alumina, known as red mud, is a type of solid waste. The engineering properties of red mud can be significantly enhanced through the modification and solidification using inorganic materials. This study primarily utilized red mud as the raw material, supplemented with fly ash, lime, and clay, to conduct a solidification experiment of red mud. Orthogonal tests with three factors of two ash ratio (ratio of lime to fly ash), two ash content (total lime and fly ash), and red mud types were designed to study the changes of different ratios and maintenance conditions, etc., on the engineering properties of red mud. In addition, the micro-mechanisms of modified red mud were investigated by means of XRF, XRD, SEM and EDX. The results show that for optimum moisture content, red mud types are the most important influencing factor and for maximum dry density, two ash content is the most important influencing factor. For strength characteristics, the optimum two ash ratio was 1.5:1, the optimum two ash content was 50%, and the optimum red mud types were 70% CRM (red mud made of Chalco Shandong Co., Ltd) mixed with 30% clay. The addition of lime, fly ash, and clay improves the temperature shrinkage coefficient of the red mud. Through the analysis of microscopic composition and structure, it can be seen that goethite (α-FeO(OH)) and magnetite (γ-Fe
2 O3 ) in the red mud reacted with the modified materials to generate crystalline aluminosilicate and amorphous hydrated silicate gel, and these products together with the original calcium carbonate (CaCO3 ), tricalcium aluminate (Ca3 Al2 O6 ) and garnet (Ca3 TiFeSi3 O12 ) in the red mud which have certain strengths enhance the structural strength of the modified red mud. The optimum ratio obtained from the combined test results was lime: fly ash: CRM = 30:20:50. Therefore, using lime, fly ash and clay as modified materials can greatly enhance the engineering properties of red mud and realise the resourceful use of red mud. [ABSTRACT FROM AUTHOR]- Published
- 2024
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9. Laboratory and field experimental study on efficiency of vacuum preloading–flocculation–solidification combined method for slurry-like mud treatment.
- Author
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Xu, Zhi-Hao, Zhang, Rong-Jun, Zheng, Jun-Jie, and Liu, Si-Jie
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PHYSICAL distribution of goods , *FLOCCULATION , *PILOT projects , *SOLIDIFICATION , *MUD - Abstract
A new integrated method, i.e., vacuum preloading–flocculation–solidification combined method (VP-FSCM), has been developed for treatment and recycling of slurry-like mud (MS). However, due to the insufficient solidification caused by the decay of vacuum pressure among other factors, the superiority of VP-FSCM under various mixing conditions and the distribution of engineering properties of VP-FSCM-treated MS are not well understood especially at the field pilot scale. In this study, a series of laboratory experiments are performed first to identify the influence of equivalent initial water content (wei) and binder content (wc) on the superiority of VP-FSCM over the conventional pure cement solidification method (PCSM), and some field pilot experiments are then conducted to further demonstrate the solidification efficiency of VP-FSCM and characterize the spatial distribution of strength of VP-FSCM-treated MS. The results indicate that VP-FSCM outperforms PCSM in treatment and utilization of MS, with the strength of VP-FSCM-treated MS being approximately 2.24 times larger than that of PCSM treated MS under the equivalent circumstance at the field pilot scale. In addition, the strength of VP-FSCM-treated MS increases substantially with the decrease in distance away from the central axis of a prefabricated horizontal drain and tends to show higher spatial variability than that of PCSM treated MS. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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10. XBTs Provide First‐Order Characterization of Seabed Physical Properties.
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Hornbach, Matthew J., Wood, Warren T., Lee, Taylor R., Phrampus, Benjamin J., Abelev, Andrei, Herdic, Peter C., Woodford, Emma, Griffith, Samuel S., Dohner, Stephanie M., and Braithwaite, Edward F.
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OCEAN temperature , *HEAT flow (Oceanography) , *OCEANOGRAPHIC instruments , *COPPER wire , *SEAWATER , *OCEAN bottom , *MUD - Abstract
Expendable Bathythermographs (XBTs) are oceanographic instruments that fall through the ocean's water column and measure ocean temperature with depth. In many instances, however, XBTs continue to record temperature after they impact the seabed. Here we show evidence that XBTs produce unique temperature responses when they impact the seabed that depend directly on seabed physical properties. Specifically, standard‐use XBTs (e.g., T‐4s and T‐5s), when deployed above a mud‐rich seabed, require significant time (tens of minutes) to equilibrate to steady‐state seafloor temperatures after seabed impact. In contrast, XBTs deployed above sand‐rich sediments equilibrate to seabed temperatures rapidly (<5 min) after seafloor impact. One explanation for this difference in temperature response is that XBTs deployed above mud‐rich sediment penetrate into low permeability marine muds that jacket the XBT, where diffusive heat flow dominates. Both observations and numerical modeling results support the hypothesis that XBTs impacting muddy seafloors exhibit slow, diffusion‐dominated heat flow, while XBTs impacting harder, sand‐rich seabed sites exhibit rapid seafloor temperature equilibration, consistent with advection‐driven heat flow and little if any XBT seabed penetration. Given that >644k XBT measurements exist publicly (via the National Oceanographic and Atmospheric Administration website), and >74,000 XBTs record temperatures post seabed impact, we suggest that XBT data represents a large, low‐cost, and currently untapped data set for characterizing seabed physical properties globally. Plain Language Summary: Expendable Bathythermographs (XBTs) are hand‐deployable torpedo‐shaped single‐use thermistors that measure ocean temperature with depth by being dropped from a ship and transmitting temperature values along a thin copper wire that unspools from the XBT as it falls. When the XBT impacts the seabed, it often continues recording temperature, however, researchers focused on ocean temperature‐depth measurements typically ignore these data. Here, we take a first‐look at XBT temperature response after seabed impact for two different seabed settings: (a) a soft muddy seabed where XBTs may penetrate the seafloor, and (b) a hard, sandy seabed where the XBT likely fails to penetrate. We find that XBTs that impact a soft, muddy seabed show significantly slower rates of change in temperature after impact compared to XBTs that impact hard sandy sediment, consistent with numerical modeling temperature predictions for XBTs impacting and penetrating mud but failing to penetrate sand. XBT temperature response after seabed impact may therefore provide a crude but efficient tool for rapidly assessing seabed physical properties (such as seabed hardness). With more than 74,000 publicly available XBT seabed temperature measurements available in every ocean, XBTs may provide a useful tool for roughly characterizing seabed properties globally. Key Points: XBT temperature response after seabed impact varies depending on seabed physical propertiesXBT rates of temperature change after seabed impact are nearly an order of magnitude lower in mud versus sand due to XBT burial in mudXBTs may provide a crude but useful, rapid tool for assessing seabed physical properties globally [ABSTRACT FROM AUTHOR]
- Published
- 2024
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11. Characteristics of mud flocs in the subseabed methane hydrate reservoir and behaviours in flowing water.
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Oyama, Hiroyuki, Ogino, Tomoya, Sato, Toru, Yasuda, Hisato, Nagao, Jiro, and Tenma, Norio
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METHANE hydrates , *MUD , *DISTILLED water , *GREENHOUSE gas mitigation , *PARTICULATE matter , *GAS seepage , *TURBIDITES - Abstract
Recently, it was found that mud flocculates, or flocs, coexist with methane hydrate within turbidite layers off the Japanese coast. There is a concern that mud flocs may be broken down by the flow of pure water generated from the dissociation of methane hydrate, causing sand troubles in the production wells. To clarify the characteristics of the flocs, in this study, the samples of mud flocs collected from natural cores having contained methane hydrate were observed before and after sonication in a pure-water ultrasonic bath. Then, these flocs were placed in distilled water flow to investigate their mechanical stability. As a result, it was confirmed that the flocs mainly consist of silt together with a little clay and fine sand. In addition, these flocs were found to be stable for flow rates on the order of magnitude of 10−3 m/s, which is expected inside the strata during gas production from methane hydrate. However, it was also found that, after the distilled water flow experiments, the flocs were decomposed into silt and clay particles when pressed with a handheld needle in the air, suggesting that the floc might be a source of the fine particles as underground stress conditions change, although not many flocs are likely to be immersed in pure water alone. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
12. High-Performance Fe-Al Double Hydroxide Prepared by Red Mud for Arsenic Removal.
- Author
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Liu, Haonan, Tang, Xincun, Tang, Zanlang, and Xiao, Zeyu
- Subjects
IRON metallurgy ,HYDROXIDES ,MUD ,ADSORPTION capacity ,ION exchange (Chemistry) ,RAW materials - Abstract
A novel Fe-Al double hydroxides adsorbent (DHs-FeAl) was synthesized utilizing red mud (RM), and then the arsenic(As)V adsorption characteristics of DHs-FeAl were evaluated. The iron-containing acid leaching residue (Fe = 63.55%) generated during the production of DHs-FeAl can be used directly as a raw material for iron metallurgy. Optimized conditions for As(V) adsorption were observed to be pH = 4.0–9.0, 1.0 g/L adsorbent dosage, 50 mg/L initial As(V) concentration, 720 min, and ambient temperature. The adsorption capacity of DH-FeAl for As(V) was up to 117.73 mg/g, as determined by fitting adsorption equilibrium data using the Langmuir–Freundlich isothermal model (R
2 > 99%). According to the adsorption thermodynamic and kinetic results, the As(V) adsorption process, controlled by coupled external and internal diffusion, was dominated by physisorption and supplemented by inner-sphere complexation and hydroxide ion exchange. When the DHs-FeAl was regenerated with an NaOH-NaCl binary solution after adsorbing As(V), the adsorbent still had a good adsorption capacity for the first three cycles. Based on the results, it was possible and efficient to adsorb As(V) using DHs-FeAl. The research complied with the notions of reusing resources and treating waste with waste. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
13. Red Mud: From Industrial Waste to a Flux for Manufacturing Sustainable Iron/Steel.
- Author
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Kannan, Rangasayee, Stevens, Adam G., and Nandwana, Peeyush
- Subjects
SUSTAINABILITY ,INDUSTRIAL wastes ,MUD ,IRON ,STEEL ,WASTE products - Abstract
This study highlights the potential of red mud/bauxite residue, an industrial waste product generated during alumina extraction as a flux for iron and steelmaking. The thermodynamic feasibility of using red mud as a flux in the presence of different reducing agents is evaluated. Potential approaches to decarbonize iron and steel production while utilizing red mud as a flux, as well as the benefits of red mud remnant after iron extraction, are discussed. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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14. Study on the Reuse of Shield Mud from Clay Stratum in Synchronous Grouting Slurry.
- Author
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Fan, Ying, Gao, Yang, Tao, Weilong, and Huang, Sihong
- Subjects
FLY ash ,METHYLCELLULOSE ,COMPRESSIVE strength ,GROUTING ,MUD ,SLURRY - Abstract
The purpose of this study is to investigate the feasibility of replacing the fly ash in synchronous grouting material by reusing the shield mud produced in the clay stratum during the shield construction of Wuhan Rail Transit Line 11. The test utilizes the shield mud from the clay stratum to replace the fly ash material in synchronous grouting at percentages of 20%, 40%, 60%, 80%, and 100%, and research and analyses are conducted on the fluidity, stability, strength, and resistance to water dispersion of the slurry after the replacement; at the same time, improvements in the undesirable phenomenon produced by the synchronous grouting slurry are also examined after the replacement. The results show that, when the fly ash is replaced by shield mud at 80%, the mortar still has good stability and strength performance, but, at the same time, the initial value of consistency and the phenomenon of flow time loss is too large. Through the adjustment of the water–binder ratio and the addition of an appropriate amount of a polycarboxylate superplasticizer agent, the adverse phenomenon of the slurry is effectively improved, and the compressive strength and ease of the slurry are also improved. At the same time, when adding an appropriate amount of hydroxyethyl methyl cellulose (HEMC), the slurry has good water dispersion resistance, but, with the gradual increase in HEMC, the fluidity of the slurry deteriorates and the compressive strength decreases. The test proves that the shield mud in the clay stratum can be used to replace most of the fly ash in an appropriate proportion, which not only solves the problem of the shield mud being difficult to work with, but also provides more valuable insights for tunneling projects. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
15. Investigation of co-combustion characteristics of distillery sludge and sugar mill waste: kinetics, synergy, and ash characterization.
- Author
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Singh, Vikash, Park, Seon Yeong, Lee, Eun Seo, Choi, Jun Ho, Kim, Chang Gyun, and Srivastava, Vimal Chandra
- Subjects
SUGAR factories ,COMBUSTION ,ACTIVATION energy ,DISTILLERIES ,MUD ,COMBUSTION kinetics - Abstract
The co-combustion characteristics and synergy of distillery effluent sludge (DES) and sugar mill waste (SMW) were studied by thermogravimetric (TG) analysis. TG data were used to evaluate the combustion indices, synergy, kinetic parameters, and heterogeneous reaction mechanisms. The blend D1S3 (25% DES and 75% SMW) exhibited optimal combustion parameters (C
i = 2.69 × 10−4 % min−3 , Cb = 1.34 × 10−6 % min−4 , and CCI = 13.02 × 10−7 %2 °C−3 min−2 ). Mixing DES with SMW resulted in a positive synergy that facilitated effective combustion owing to the presence of Fe, Ca, and Mg in DES, which served as catalysts during combustion. For D1S3, the apparent activation energy (* Ea ) calculated using FWO, KAS, and ST iso-conversional methods were 173.3, 172.4, and 172.7 kJ mol−1 , respectively. The master plots revealed that the combustion process was governed by the D1, D3, F2, and F3 solid-state kinetic models in different conversion (α) ranges for the wastes and their blends. Finally, the presence of alkaline and alkaline-earth elements (Na, K, Mg, and Ca) was confirmed through ash characterization. Thus, the ash can be considered a possible supplementary cementing material for end-use applications. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
16. Anticipating the winds of change: A baseline assessment of Northeastern US continental shelf surficial substrates.
- Author
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Stokesbury, Kevin D. E., Bethoney, N. David, Restrepo, Felipe, and Harris, Bradley P.
- Subjects
- *
CONTINENTAL shelf , *WIND power industry , *GEOLOGY databases , *BIG data , *WIND power , *ENERGY development - Abstract
The introduction of thousands of wind turbines along the North American Atlantic continental shelf over the next decade will constitute the largest regional change in marine substrates since the retreat of the Laurentide Ice Sheet over 14,000 years ago. Here, two large data sets, SMAST drop camera survey (242,949 samples, 2003 to 2019) and the US Geological Survey databases (27,784 samples, 1966 to 2011), are combined to derive sea floor surficial substrate probability maps for the Northeastern US continental shelf from Virginia Beach to the Gulf of Maine to 300 m depth (218,571 km2). Geostatistical models were used to estimate the probability of five geologic and one biogenic substrate types being present at a 250 m resolution, and the proportional contribution of each substrate type to the seabed composition at a 500 m resolution. By providing the first synoptic maps depicting the probability of a particular substrate or combination of substrates occurring at any location on the Northeastern US continental shelf, including planned wind energy sites, we aim to (1) provide insights regarding how substrates in the areas selected for wind energy development compare with other locations, (2) motivate the development of a priori expectations for ecosystem changes to inform monitoring and research efforts going forward, and (3) to provide a baseline characterization of the Northeastern US continental shelf surficial substrates to support robust examination of the future changes observed in areas impacted by wind energy installations. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
17. Reducing Torque and Drag in Extended-Reach Wells Using Thermoplastic Polymers for Protective Sliding Rings.
- Author
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El Sabeh, Karim, Pašić, Borivoje, Mijić, Petar, and Medved, Igor
- Subjects
MECHANICAL wear testing ,MECHANICAL wear ,LUBRICANT additives ,FRICTION ,MUD - Abstract
Extended-reach drilling represents an advanced way of drilling and accessing reservoirs that were previously economically not feasible to drain, impossible to reach or in an environmentally sensitive area. One of the main issues that appears while drilling such wells is caused by the high values of friction factor which cause high values of torque and drag. One of the suggested solutions is to use a protective sliding ring made from materials such as POM, Teflon and PA6 in combination with lubricants added to a polymer mud system. First, measurements were conducted on a lubricity tester to choose the best material and, after finishing, a mechanical wear test was conducted on a specially designed device to measure mechanical wear. Results showed that Teflon showed lower values of friction factor in comparison to steel and the mechanical wear was minimal. The lowest value of friction force was recorded for blocks made from Teflon in tested mud systems. It is also noticeable that, in polymer mud with weighting additives and lubricant, the value of the friction force is higher than in polymer mud with lubricant only. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
18. Red mud treated with KOH: synthesis of sustainable materials from waste for water treatment.
- Author
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Belviso, Claudia, Mancinelli, Maura, Abdolrahimi, Maryam, Sturini, Michela, Cavalcante, Francesco, Lettino, Antonio, and Peddis, Davide
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WATER purification ,WASTE treatment ,SEWAGE ,MUD ,SOLID waste - Abstract
Solid waste resulting from bauxite ore (red mud) was converted into useful products consisting in hydrogarnet together with zeolite. Red mud (RM) transformation from disposal material into new source was carried out using potassium hydroxide as an activator and hydrothermal process (HY) or vapor phase crystallization (VPC) approach. HY process was performed at 60, 90, and 130 °C whereas during the VPC method, red mud was contacted only with vapor from the distilled water heated at 60 and 90 °C. The results indicate the formation of katoite and zeolite L (LTL topology) with both approaches. All the synthetic products display magnetic properties. In addition, a preliminary investigation on arsenic removal from drinking water (from 59 to 86%), makes the synthetic materials appealing for environmental applications. Finally, the synthesis of a large amount of very useful newly-formed phases using vapor molecules confirms the efficiency of the innovative and green VPC process in waste material transformation. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
19. Pile Penetration Analysis and Suggestions of Jacket Platform Skirt Pile Sinking.
- Author
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Liu, Xinyu, Yu, Faling, Zhang, Xiulin, Gao, Bingzhen, Tang, Jing, Zhang, Yanming, and Hu, Li
- Subjects
- *
BUILDING foundations , *PILES & pile driving , *ENERGY conservation , *MUD , *STEEL - Abstract
When the pile driving operation of the jacket platform is carried out, the depth of the steel pile into the mud is not enough or the maximum penetration depth of the steel pile is not the expected bearing layer, which will make the bearing capacity of the platform pile foundation insufficient, cause the platform to be unstable and cause safety accidents. In this paper, the energy conservation relationship in the process of pile sinking is analyzed and discussed from the calculation theory of hammering work and internal force work. Combined with the soil data of field engineering, the penetration of pile sinking of jacket platform is calculated and theoretically demonstrated. Through the above in-depth calculation and analysis, the variation law of penetration with formation depth is obtained. Finally, the control suggestions of pile sinking operation of jacket platform are obtained, in order to provide reference for engineering operation. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
20. Numerical Simulation Investigation of Vertical Bearing Characteristics of Deep Water Expandable Surface Conductor.
- Author
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Liu, Shujie, Chen, Haodong, Luo, Ming, Zhang, Xun, Jiang, Donglei, Wu, Yanhui, Yang, Yupeng, and Wan, Hongyu
- Subjects
- *
UNDERWATER drilling , *MECHANICAL models , *SURFACE structure , *COMPUTER simulation , *MUD - Abstract
Deep water areas with soft subsea soils, conventional surface conductor into the mud depth is too deep, long waiting time for resting, prone to surface conductor sinking and submerged wellhead instability. In this paper, based on the basic principles of mechanics and the understanding of the structure of the surface conductor, a mechanical model of the bearing capacity of the surface conductor is established. Three types of expandable surface conductors were designed by changing the distribution of the expansion material, in contrast to conventional surface conductors. The bearing characteristics of different structural surface conductors are also investigated by changing the soil parameters from the strength of the submarine soil. The study has obtained: the load-bearing capacity comparison graph between conventional surface conductor and expandable surface conductor; the load-bearing capacity change of expandable surface conductor under the change of soil parameters and the change of expansion material section; and the load-bearing capacity improvement effect of the three expandable surface conductors designed in the paper compared with conventional surface conductors, using stress as the evaluation criterion. This paper provides technical support for the design of expandable surface conductors and provides a basis for numerical simulation of surface well construction. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
21. Preparation and Immobilization Mechanism of Red Mud/Steel Slag-Based Geopolymers for Solidifying/Stabilizing Pb-Contaminated Soil.
- Author
-
Wang, Xinyang and Xue, Yongjie
- Subjects
- *
CALCIUM silicate hydrate , *MUD , *HEAVY metal toxicology , *FOURIER transform spectrometers , *X-ray photoelectron spectroscopy - Abstract
Pb-contaminated soil poses serious hazards to humans and ecosystems and is in urgent need of remediation. However, the extensive use of traditional curing materials such as ordinary Portland cement (OPC) has negatively impacted global ecology and the climate, so there is a need to explore low-carbon and efficient green cementitious materials for the immobilization of Pb-contaminated soils. A red mud/steel slag-based (RM/SS) geopolymer was designed and the potential use of solidifying/stabilizing heavy metal Pb pollution was studied. The Box–Behnken design (BBD) model was used to design the response surface, and the optimal preparation conditions of RM/SS geopolymer (RSGP) were predicted by software of Design-Expert 8.0.6.1. The microstructure and phase composition of RSGP were studied by X-ray diffractometer, Fourier transform infrared spectrometer, scanning electron microscopy and X-ray photoelectron spectroscopy, and the immobilization mechanism of RSGP to Pb was revealed. The results showed that when the liquid–solid ratio is 0.76, the mass fraction of RM is 79.82% and the modulus of alkali activator is 1.21, the maximum unconfined compressive strength (UCS) of the solidified soil sample is 3.42 MPa and the immobilization efficiency of Pb is 71.95%. The main hydration products of RSGP are calcium aluminum silicate hydrate, calcium silicate hydrate and nekoite, which can fill the cracks in the soil, form dense structures and enhance the UCS of the solidified soil. Pb is mainly removed by lattice immobilization, that is, Pb participates in geopolymerization by replacing Na and Ca to form Si-O-Pb or Al-O-Pb. The remaining part of Pb is physically wrapped in geopolymer and forms Pb(OH)2 precipitate in a high-alkali environment. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
22. TOXICITY EVALUATION OF SINGLE AND MULTIPLE MIXTURES OF SOME FACIAL COSMETICS ON MUD CATFISH (Clarias gariepinus) FINGERLINGS.
- Author
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OSUALA, F. I., OLUMIDE, H. F., ABIODUN, OLUSHOLA, A., IGWO-EZIKPE, M. N., and OVIAHON, O. B.
- Subjects
- *
CLARIAS gariepinus , *TOXICITY testing , *CATFISHES , *COSMETICS , *MUD , *BINARY mixtures - Abstract
Astronomical discharge of facial cosmetic products into the aquatic environments exposes aquatic organisms to these pollutants. Eight facial cosmetic products such as Milani Powder, Ponds Primer, Zikel Powder, Zaron concealer, Glam gal's foundation, Maybelline foundation, L.A Girl concealer and Milk of Magnesia were evaluated for relative acute toxicity (single and joint action) against Clarias gariepinus in static laboratory bioassays. Single action toxicity data were statistically analysed based on Probit, while the Synergistic Ratio and Concentration - Addition analysed joint action. Results of acute toxicity (single action) based on 96hrLC50 values showed that Milani Powder (184.14 mg/l) was the most toxic, followed by Ponds Primer (230.95 mg/l), Zikel powder (233.58 mg/l), Aaron concealer (384.47 mg/l), Glam Gals' foundation (421.83 mg/l), Maybelline foundation (565.32 mg/l), L, A Girl concealer (587.75 mg/l) and Milk of Magnesia (2218 mg/l) in descending order of toxicity. Joint action toxicity evaluation of the binary, trinary and quaternary mixtures subjected to the Synergistic Ratio and Concentration showed that binary mixtures tended towards synergism and antagonism in varied ratios and combinations. The ratio of toxicity units for all mixtures interaction tended to synergism and could be dangerous to the biota. Therefore, strict regulation standards should be enforced to protect the environment and make eco-friendly alternative ingredients that can be incorporated into these products. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
23. The effect of substrate type composition on the growth of the seaweed Gracilaria verrucosa in controlled containers.
- Author
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Muchdar, Fatma, Irfan, Muhammad, Andriani, Rovina, Yuliana, and Jolo, Nurbaya
- Subjects
- *
SUBSTRATES (Materials science) , *MARINE algae , *RESEARCH implementation , *CORALS , *MUD - Abstract
Naturally, seaweed Gracilaria lives on various aquatic substrates including sandy, mud, coral and coral fragments, but scientific information that reveals the extent to which substrates influence the growth of this type of seaweed in cultivation has not been widely studied. The aim of this research is to determine the type of substrate that influences the growth of seaweed G. verrucosa, and to determine the best substrate for seaweed G. verrucosa. Collecting samples of seaweed G. verrucosa in the waters of Kalumata Ternate for 5 days. The cultivation process in a controlled container was carried out at the Unkhair Integrated Laboratory UPT, Sasa Village for 45 days. The overall research implementation time is 50 days from May-July 2022. The results of the research showed that the composition of the substrate type had a very significant effect on the absolute weight growth and relative growth of the seaweed G. verrucosa. The type of coral fragment substrate had the best influence on absolute weight growth with an average value of 57.33 grams, followed by sandy substrate at 37 grams, and the lowest was muddy substrate at 30.66 grams. The coral fragment substrate also had the best influence on relative growth at around 8.991%, and the lowest was found on the muddy substrate at around 7.593%. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
24. Density‐dependent trophic consequences of invasive mrigal carp on native mud carp in Chinese fresh waters.
- Author
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Zhang, Yingqiu, Li, Jie, Chen, Fangcan, Li, Yuefei, Dai, Shouhui, and Britton, J. Robert
- Subjects
- *
FRESH water , *NATIVE fishes , *SIZE of fishes , *MUD , *CARP , *ECOLOGICAL impact , *PLANT invasions , *BIOLOGICAL invasions - Abstract
Understanding the strength, direction and consequences of the trophic impacts of invasive fish on functionally analogous native fishes is important in invasion impact assessment and for informing management programmes. As functionally analogous native and invasive fishes can share prey resources, there is high potential for competitive interactions, which could affect trophic niche sizes and positions.The highly invasive mrigal carp Cirrhinus mrigala and native mud carp Cirrhinus molitorella now co‐exist in many freshwaters in southern China, raising concern on the consequences for mud carp. The trophic interactions of the two species and their consequences (for growth rates and trophic niche sizes as the isotopic niche, calculated using δ13C and δ15N) were tested in a pond enclosure experiment based on additive and substitutive treatments using fish in allopatric and sympatric contexts, with results compared with invaded wild communities.In the experiment, specific growth rates decreased significantly as fish abundance in treatments increased. These density‐dependent effects were observed in both species and were independent of whether the treatment was allopatric or sympatric. In allopatric treatments, isotopic niches of mud carp increased in size with fish number. Conversely, in sympatric treatments, mud carp isotopic niche size decreased with increased mrigal carp number. For mrigal carp, isotopic niche sizes decreased as fish number increased in both allopatric and sympatric treatments.In sympatric experiment treatments, the isotopic niches of mud carp and mrigal carp were always divergent. This was, however, in contrast to four invaded wild communities, where the isotopic niches of the two fishes always had some overlap.Experimental and field data suggest that although native mud carp could be impacted by mrigal carp, these impacts might only manifest when the species are at very high abundances and inter‐specific competitive interactions could be intense. These results also suggest the two species have mechanisms that reduce their inter‐specific interactions to minimise their competitive interactions, thus any ecological impacts from mrigal carp might manifest more from indirect than direct processes. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
25. Mudding the playing field. Fiscal contributions to municipalities as a political construction.
- Author
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Clerici, Paula, Demeco, Lucía, Galeano, Franco, and Negri, Juan
- Subjects
- *
ATHLETIC fields , *CITIES & towns , *EMPLOYEE loyalty , *MUD , *MAYORS , *GOVERNORS - Abstract
In federal presidential democracies, discretionary transfers are often mentioned as a tool used by the national executive to build and strengthen subnational support, typically governors. Funds to local mayors, however, have been much less studied. With original data, in this study we analyze the distribution of a particular discretionary transfer (ATN) to the Argentine municipalities during two periods: 1997–2000 and 2016–2019. We show that the main driver for transfers is the mayor's political alignment. Indeed, the president is more likely to reward loyal mayors, but especially when both the latter and the President oppose the provincial governor. By this token, we highlight a nested political game, in which the President considers the loyalty of both mayors and governors combined to decide when to reward (or when not to reward) municipalities. Furthermore, we find that the Executive provides aid to smaller municipalities to circumvent the possibility of funding mayors from larger cities who may pose a threat as political rivals in the future. Since this pattern is more evident in localities with aligned mayors, we can infer that the President's strategy is aimed at preventing future challengers from within their own coalition. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
26. Preparation of red mud/waste bacterial residue magnetic biochar and removal of norfloxacin in water.
- Author
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ZHAO Jin, LI Hongyan, ZHANG Feng, DONG Yinghong, GUI Jiali, and WANG Fang
- Subjects
- *
EDIBLE coatings , *BIOCHAR , *BODIES of water , *MUD , *NORFLOXACIN , *HYDROGEN bonding interactions - Abstract
Using red mud from alumina industry waste and edible fungus industry waste fungus rod as raw materials, red mud/waste fungus magnetic biochar (RMMBC) was prepared by co-pyrolysis method, and its morphological characteristics, pore structure and surface functional group changes were analyzed, its adsorption effect on norfloxacin(NOR) in water was explored, and its adsorption mechanism was explored by adsorption kinetics and isothermal adsorption characteristics, and tested in actual wastewater. The results showed that the optimal preparation conditions were raw material ratio (red mud, waste bacterial residue, urea) 1: 2.5: 0.5, calcination time 1 h, calcination temperature 700 °C. The maximum removal rate of NOR was 96.3% when a NOR concentration was 10 mg/L and 0.25 g RMMBC was added. The results showed that RMMBC had a large specific surface area(59.295 m²/g), pore volume (20.157 cm³/g) and saturation magnetic susceptibility(16.735 emu/g). The quasi-secondary kinetics of RMMBC and the Fre- undlich isothermal model can accurately describe the adsorption process of NOR on RMMBC, indicating that chemisorption may be the main mechanism of NOR adsorption on RMMBC, mainly including IT-IT interaction, surface complexation, hydrophobicity, hydrogen bonding and electrostatic interaction. The use of red mud and waste bacterial residue to prepare magnetic biochar adsorption effect is remarkable, which has the advantage of easy separation from the water body to avoid secondary pollution to the environment, which not only provides new ideas for low-cost treatment of antibiotic wastewater, but also helps to realize the stability, harmlessness and resource utilization of red mud and waste bacterial residue, and achieves the environmental protection goal of "waste treatment". [ABSTRACT FROM AUTHOR]
- Published
- 2024
27. Multi‐factor analysis of the quality of cellar mud of Luzhou‐flavor liquor in Yibin production area.
- Author
-
Han, Baolin, Zhou, Weitao, Chen, Rangfang, Tian, Shulin, Gong, Hucheng, Wang, Yu, Xu, Qiang, and Bian, Minghong
- Subjects
- *
FLAVOR , *BASEMENTS , *GAS chromatography/Mass spectrometry (GC-MS) , *MUD , *BACTERIAL communities , *LIQUORS - Abstract
The aim of this study was to conduct a thorough scientific investigation into the similarities and differences in the quality of the cellars of different Luzhou‐flavor liquor wineries in Yibin production area and the reasons for them. This study analyzed cellar mud samples from five wineries in Yibin production area. The analysis of volatile flavor compounds was carried out using headspace solid‐phase microextraction and gas chromatography–mass spectrometry. The bacterial and archaeal community structures and their correlations were analyzed by high‐throughput sequencing. The study indicates that the Distillery A had the highest levels of ammonium nitrogen and effective phosphorus, Distillery F had the highest humus levels, and Distillery I had the highest pH levels. The community structure of the principal bacterial and archaeal communities in the five subterranean clays exhibited similarity, and all samples were dominated by Firmicutes as the primary bacterial group. However, there was variation in bacterial abundance. The cellar mud also has obvious regional differences, and there are three genera of differentially dominant archaea in the archaea. In summary, significant differences were observed in the physicochemical indexes of bacterial and archaeal abundance across all five samples. These differences led to variations in both the content and composition of volatile constituents. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
28. Influence of red mud as a catalyst in the thermocatalytic reforming process.
- Author
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Onyishi, Hillary O., Neidel, Johannes, Daschner, Robert, Apfelbacher, Andreas, and Hornung, Andreas
- Subjects
- *
CATALYST supports , *MUD , *CATALYTIC reforming , *CATALYSTS , *BIOCHAR , *BIOMASS conversion , *BIOMASS liquefaction , *BIOMASS gasification , *BIOGAS - Abstract
This work studies red mud, a residue from the processing of bauxite, as a support catalyst in the thermocatalytic reforming (TCR) process, using wood, digestate, and straw as case studies. Thermocatalytic reforming is a thermochemical process for the conversion of biomass into biofuels, combining intermediate pyrolysis and catalytic reforming and resulting in high‐quality biofuels. The quantity and quality of the catalyst in the postreformer is vital as it influences the reactions taking place in it. Normally, nonreactive components of the char produced in the process act as the catalyst in the postreformer but adding a support catalyst may improve the products. In this work, red mud is introduced in the process by mixing it with the feedstock in a ratio of 1:3. The results, in comparison with normal TCR experiments on the same feedstock materials, show that the introduction of red mud into the process generally reduces the biochar yield and generally increases the biogas and product water yields, and the bio‐oil yield remains constant. Its introduction also increases the hydrogen fraction of the gas and tends to reduce the nitrogen and sulfur content of the products, thus improving their quality. These observations are consistent across feedstock materials and postreformer temperatures. The results therefore suggest that red mud is a good support catalyst for increasing the gas yield, increasing the hydrogen fraction of the gas, and improving the quality of the products from the TCR process. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
29. 考虑非达西渗流的泥浆离心脱水分析.
- Author
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刘忠玉, 刘朝凡, 杨宸宇, and 汪良强
- Abstract
Copyright of Journal of Harbin Institute of Technology. Social Sciences Edition / Haerbin Gongye Daxue Xuebao. Shehui Kexue Ban is the property of Harbin Institute of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2024
- Full Text
- View/download PDF
30. Primer registro de Chalybion californicum (Hymenoptera: Sphecidae) en Chile.
- Author
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Barrera-Medina, Roberto and Delpiano, Rafael
- Subjects
BROOD parasitism ,WASPS ,MUD ,SPIDERS ,SPECIES - Abstract
Copyright of Acta Zoologica Lilloana is the property of Fundacion Miguel Lillo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2024
- Full Text
- View/download PDF
31. Automatic mud diapir detection using ANFIS expert systems algorithm; a case study in the Gorgan plain, Iran.
- Author
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Hedayat, Bahareh, Soleimani Monfared, Mehrdad, and Losada, Luis Somoza
- Subjects
EXPERT systems ,DIAPIRS ,MUD ,PETROLEUM reserves ,HYDROCARBON reservoirs ,GEOPHYSICAL prospecting ,SYSTEMS design - Abstract
Automatic seismic data interpretation is a significant method in the exploration of geophysics. Complexities of the subsurface structures and the subsurface wave propagation media, make the decision-making process difficult in seismic data interpretation. Nevertheless, the extent of related knowledge and using the expert system method in seismic data interpretation can mitigate this problem. An expert system is a knowledge-based system that applies its knowledge in a complex and specific area and acts as an expert end-user consultant. This study investigates the design of an ANFIS expert system for mud diapirs detection with seismic data analysis in Gorgan plain. This method was applied to seismic attributes from a complex geological mud diapir bearing structure from south of the Caspian Sea. The south of the Caspian Sea is one of the richest area as petroleum reserves, and the Gorgan plain has various mud diapirs, which act as indicators of hydrocarbon reservoirs. The expert system design process to identify mud diapirs on seismic sections was modeled in two approaches including manual and automatic seismic data interpretation. In the first approach, the experience of the expert was collected by manual interpretation of training data and used to create a knowledge base and inference of the expert system in the second approach. The validation verified the accuracy of this method with an average accuracy of 90.1% according to using minimum knowledge to develop a knowledge base of the designed ANFIS expert system. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
32. Activation Behavior and Mechanism of Sodium Sulfate for Iron Recovery from Red Mud through Magnetization Roasting–Magnetic Separation.
- Author
-
Liu, Mingxia, Yao, Zhaohui, Hu, Chaojie, Xu, Kang, Wang, Ruixu, and Zhang, Hanquan
- Subjects
WASTE recycling ,MUD ,MAGNETIZATION ,SOLID waste ,CARBON monoxide - Abstract
It is a hot topic to recover iron from red mud in the research field of solid waste comprehensive utilization, but high-quality iron concentrate is always difficult to be obtained unless by high-temperature reduction roasting–magnetic separation. In this study, low-temperature magnetization roasting–magnetic separation has been conducted to recover iron from red mud, with carbon monoxide as the reducing agent, and the effect of Na
2 SO4 as an additive and corresponding activation mechanism has been investigated, confirming that Na2 SO4 can significantly improve the quality of the iron concentrate. Under the optimum conditions, an iron concentrate with a total iron grade of 60.65% and a recovery of 94.01% could be obtained, increased by 3.46% and 2.76%, respectively, compared with that in the absence of Na2 SO4 . This verified that weak-magnetic hematite was transformed into strong-magnetic magnetite by reductive roasting. The iron content in the magnetite was raised from 0.93% in red mud to 80% and 82%, respectively, for the roasted briquettes in the absence and presence of Na2 SO4 . As Na2 SO4 contributed to not only the reduction and enrichment of iron minerals but also to the decomposition of iron-containing complex oxides, the separation of the iron and the magnetic property intensity of iron concentrate was enhanced. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
33. 白酒人工窖泥培養方法研究進展.
- Author
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靳喜慶, 馮亮, 張無疾, 黃祖雙, 曹滿堂, 黃彪, 諶松強, 向宗府, 劉飄洋, and 李亞平
- Subjects
QUALITY control ,SCIENTIFIC method ,MUD ,RAW materials ,SALT - Abstract
Copyright of China Brewing is the property of China Brewing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2024
- Full Text
- View/download PDF
34. Study on Stability and Deformation Characteristics of Ultra-Deep Diaphragm Wall during Trench Excavation.
- Author
-
Ma, Jianhua, Hu, Gang, Rui, Rui, Ding, Ruiheng, and Sun, Tianjian
- Subjects
DIAPHRAGM walls ,SAFETY factor in engineering ,NUMERICAL analysis ,TRENCHES ,MUD - Abstract
The stability and deformation during trenching of ultra-deep diaphragm walls have a greater impact on the construction of diaphragm walls. The conventional limit equilibrium method, known as the vertical slices method, assumes homogeneity within the rock and soil mass, making it challenging to account for their stratification. Based on the limit equilibrium method, the horizontal strip method takes into account the stratification of the foundation soil. Based on the actual project, considering the different mud unit weights and heights, the horizontal strip method was used to analyze the stability of the groove trench and analyze the deformation law of the groove trench by the finite element method. The results indicate the following: The horizontal strip method can effectively assess the influence law of mud weight and height on the safety coefficient of groove trench stabilization. The higher the unit weight and level of slurry, the greater the wall safety coefficient. Moreover, the mud unit weight obtained by the horizontal strip method is about 12.70~12.64 kN/m
3 , which is close to the actual maximum mud weight of 12.5 kN/m3 . The estimated mud unit weight aligns more closely with actual conditions. Additionally, through finite element analysis, the deformation law of the groove trench of ultra-deep diaphragm walls has been analyzed and summarized. The soil around the groove trench does not move inward, which shows three different deformation modes with different depths. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
35. Environment Assessment of Modified Red Mud Utilized in Roadbed.
- Author
-
Cheng, Yu, Jiang, Na, Wang, Wentong, Jin, Lu, and Yan, Shiying
- Subjects
ACUTE toxicity testing ,GERMINATION ,MUD ,RISK assessment ,POLLUTANTS - Abstract
Utilization of red mud in road projects is an effective way to consume large amounts of red mud on a large scale. In order to meet the requirements for road performance, a modified material, Heinchem, has been developed on the basis of extensive experiments, and the long-term environmental risks of red mud modified by this material have been investigated. By collecting and modifying original red mud samples, a series of continuous leaching tank experiments are carried out based on the exposure scenario analysis. According to the leaching content of pollution in the original and modified red mud, the characteristic pollutants are identified. The release mechanism of these characteristic pollutants in the modified red mud is revealed, and the long-term release amount is predicted. Furthermore, in light of the actual road use scenario of the modified red mud, a risk assessment model is established and used to simulate the release, migration, and transformation of characteristic pollutants during the use of modified red mud as roadbed material. The groundwater environmental risk is then assessed. Finally, an acute toxicity test of earthworms and a seed germination test are conducted to investigate the impact of the modified red mud on the farmlands. The results showed that the proposed red mud modified materials have obvious curing effects on V, As, Se, Mo, and F. When the leaching contents of V, Cr
6+ , Cr3+ , As3+ , Se4+ , Se6+ , Mo, and F in the modified red mud were lower than 0.15 mg/L, 0.1 mg/L, 0.2 mg/L, 0.012 mg/L, 0.012 mg/L, 0.012 mg/L, 0.075 mg/L, and 1.2 mg/L, respectively, the environmental risk of modified red mud during long-term road use is acceptable. This study provides a new way for the resource utilization of red mud. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
36. Robust fracture intensity estimation from petrophysical logs and mud loss data: a multi-level ensemble modeling approach.
- Author
-
Azadivash, Ahmad, Soleymani, Hosseinali, Seifirad, Atrina, Sandani, Amirali, Yahyaee, Farshid, and Kadkhodaie, Ali
- Subjects
MULTILEVEL models ,DATA logging ,MACHINE learning ,HYDROCARBON reservoirs ,MUD ,RANDOM forest algorithms - Abstract
This study presents a pioneering machine learning approach to continuously model fracture intensity in hydrocarbon reservoirs using solely conventional well logs and mud loss data. While machine learning has previously been applied to predict discrete fracture properties, this is among the first attempts to leverage well logs for continuous fracture intensity modeling leveraging advanced ensemble techniques. A multi-level stacked ensemble methodology systematically combines the strengths of diverse algorithms like gradient boosting, random forest and XGBoost through a tiered approach, enhancing predictive performance beyond individual models. Nine base machine learning algorithms generate initial fracture intensity predictions which are combined through linear regression meta-models and further stacked using ridge regression into an integrated super-learner model. This approach achieves significant improvements over individual base models, with the super-learner attaining a mean absolute error of 0.083 and R^2 of 0.980 on test data. By quantifying the crucial fracture intensity parameter continuously as a function of depth, this data-driven methodology enables more accurate reservoir characterization compared to traditional methods. The ability to forecast fracture intensity solely from conventional well logs opens new opportunities for rapid, low-cost quantification of this parameter along new wells without requiring advanced logging tools. When incorporated into reservoir simulators, these machine learning fracture intensity models can help optimize production strategies and recovery management. This systematic stacked ensemble framework advances continuous fracture intensity modeling exclusively from well logs, overcoming limitations of prior techniques. Novel insights gained via rigorous model evaluation deepen the understanding of naturally fractured reservoirs. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
37. 土石围堰防渗墙快速施工时泥浆渗透特性 及渗透系数反演方法研究.
- Author
-
徐世濠, 赵银超, 吴都督, and 苏凯
- Abstract
Copyright of China Rural Water & Hydropower is the property of China Rural Water & Hydropower Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2024
- Full Text
- View/download PDF
38. Characterization of phosphate modified red mud–based composite materials and study on heavy metal adsorption.
- Author
-
Jin, Wenlou, Yang, Yanzhi, Jin, Jiacheng, Xu, Mingchen, Zhang, Zhipeng, Dong, Fan, Shao, Min, and Wan, Yushan
- Subjects
HEAVY metals ,ADSORPTION capacity ,PH effect ,COMPOSITE materials ,MUD ,CARBONIZATION ,PHOSPHATES - Abstract
In this paper, Bayer red mud (RM) and lotus leaf powder (LL) were used as the main materials, and KH
2 PO4 was added to modify the material. Under the condition of high-temperature carbonization, RMLL was prepared and phosphate modified red mud matrix composite (PRMLL) was prepared based on KH2 PO4 modification, which can effectively remove Pb2+ from water. The optimum preparation and application conditions were determined through orthogonal experiment: dosage 0.1g, ratio 1:1, and temperature 600 °C. The effects of pH, dosage, and initial concentration on the adsorption of Pb2+ were studied. The pseudo-first-order, pseudo-second-order, and Elovich kinetic models were fitted to the experimental data. It was found that RMLL and PRMLL were more consistent with the pseudo-second-order kinetic model and chemisorption. Langmuir, Freundlich, Timkin, and Dubinin-Radushkevich isothermal adsorption models were used to fit the experimental data. It was found that RMLL and PRMLL were more consistent with Langmuir model. In addition, the maximum adsorption capacity of RMLL and PRMLL was 188.1 mg/g and 213.4 mg/g, respectively. It is larger than the adsorption capacity of their monomers. Therefore, the use of RMLL and PRMLL as the removal of Pb2+ from water is a potential application material. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
39. Study on the effect of sodium removal from citric acid pretreated red mud on the physical properties of red mud.
- Author
-
Cai, Tingya, Yang, Min, and Pan, Rongxiang
- Subjects
CITRIC acid ,MUD ,CALCIUM oxalate ,SODIUM ,MAGNESIUM hydroxide ,SOLID waste - Abstract
Red mud is a highly alkaline solid waste discharged from the alumina industry, and its high sodium content is the key factor limiting its wide utilization. Therefore, effective control of the "frosting" phenomenon during the application of red mud has received significant attention. In this study, the changes of particle size, phase, morphology, and pore size of red mud after sodium removal with different amounts of citric acid pretreatment were investigated. The single-factor experiment shows that the Na
+ leaching rate is 86.33% under a citric acid dosage of 15%, liquid-to-solid ratio of 7 mL/g, leaching temperature of 80 °C, stirring speed of 300 rpm, and leaching time of 10 min. The leachate is characterized through X-ray diffraction (XRD), scanning electron microscopy (SEM), and Brunauer–Emmett–Teller (BET) surface area analysis. The results reveal that Na+ mainly exists in a combined state in the form of cancrinite. With the increase of citric acid dosage, red mud agglomerates, calcite, and cancrinite are dissolved, and new phases such as calcium oxalate and magnesium aluminum hydroxide are formed. The specific surface area, pore volume, and pore diameter show irregular changes with the increase in the citric acid dosage. Citric acid pretreatment can effectively reduce the sodium content in red mud, the treatment cost of leaching solution is low, and the leaching residue is neutral, which is helpful to promote the practical application of red mud. [ABSTRACT FROM AUTHOR]- Published
- 2024
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40. Effects of 2 wintering practices on behavioral and physiological indicators of welfare of nonlactating, pregnant dairy cattle in a pasture-based system
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K.E. Schütz, B. Latimer, N. McDonald, L.B. Hunter, F.J. Huddart, T. Watson, L.-R. Saunders, N.J. Kells, N.R. Cox, and R.M. Monaghan
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animal welfare ,mud ,thermoregulation ,wintering ,Dairy processing. Dairy products ,SF250.5-275 ,Dairying ,SF221-250 - Abstract
ABSTRACT: In countries with pasture-based dairy systems and relatively cold winters, such as New Zealand, it is common to manage pregnant, nonlactating cows on forage crop paddocks rather than pasture, due to slow pasture growth rates. Wintering dairy cattle on grazed crops can compromise welfare if wet and muddy underfoot conditions occur, which can reduce lying. This study investigated behavioral and physiological indicators of welfare of cows under 2 wintering practices: cows managed on and grazed kale crop (Brassica oleracea), and cows managed on pasture with baled hay. Following dry-off (d 0), 80 cows were randomly assigned to 1 of the 2 wintering practices (40 cows/practice) and monitored between d 4 and 32 (phase 1). During this period, lying and stepping behavior was continuously recorded using leg-based accelerometers. Blood samples were obtained at d 0 and 32 for measurements of thyroxine (T4), nonesterified fatty acids (NEFA), white blood cells (WBC), and red blood cells. All data for phase 1 were presented descriptively due to the lack of treatment replication. Daily mean air temperature during this period was 5.2°C (range: 0.0–10.7°C), and rainfall was 1.1 mm/d (range: 0–5.6mm/d). Between d 4 and 32, cows in both groups spent similar amounts of time lying (pasture with hay cows: 8.9 h/24 h ± 2.57, kale crop cows: 8.7 h/24 h ± 3.06, mean ± SEM). Both groups reduced their lying on wet and cold days, and there was evidence of rebound lying once unfavorable weather conditions stopped. Cows on kale crop had numerically higher NEFA and lower WBC compared with cows managed on pasture, although most physiological values were within normal ranges. In a second phase of the study (d 34 and 35), cows were managed under controlled, replicated conditions in the 2 wintering practices using typical on-farm stocking rates (2 or 4 cows per group in the pasture with hay and kale crop treatments, respectively; n = 10 groups/treatment). During this period, cow behavior, skin and surface temperatures, hygiene scores, feed intakes, and ground conditions were measured. Weather conditions during the 48-h exposure were mostly cold and dry (mean air temperature: 7.8°C, range: −2.2 to 20.5°C). Cows managed on pasture with hay spent more time lying down on the first day of exposure; however, this was likely due to less space being available to kale cows on this day. Cows managed on pasture with hay ruminated more than cows on kale crop on both days of observations (d 1: 37.9% vs. 30.9% of observations, d 2: 36.8% vs. 28.7% of observations for pasture with hay and kale crop groups, respectively) and were lying more often in postures indicative of greater thermal comfort. Cows managed on pasture with hay had higher skin and surface temperatures compared with cows on kale crop, whereas cows on kale crop had dirtier coats. Results suggest that opportunities for thermal comfort were greater for cows managed on pasture with hay bales, which may be due to increased rumination activities and more insulated lying areas.
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- 2024
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41. The study of Na+, K+, Ca2+, Mg2+ ions behavior in potassium extraction from Bledug Kuwu Mud, Grobongan, Indonesia as raw materials of potassium fertilizer.
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Lalasari, Latifa Hanum, Prihadiyono, Fauzan I., Marliyana, Soerya D., Irawan, Januar, Setiawan, Iwan, Arini, Tri, Andriyah, Lia, Sulistiyono, Eko, Natasha, Nadia C., Yunita, Fariza E., Suharyanto, Ariyo, Rohmah, Miftakhur, and Firdiyono, F.
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- *
POTASSIUM fertilizers , *POTASSIUM ions , *MUD , *RAW materials , *PRECIPITATION (Chemistry) , *POTASSIUM , *LIMESTONE - Abstract
Bledug Kuwu, Grobogan, Central Java is rich in salts in the form of Na+, K+, Ca2+, Mg2+. This natural potential can be used as an alternative material for making potassium fertilizer needed for plants. This research tries to extract potassium from Kuwu Bledug mud using a process of aquadest leaching, partial evaporation and selective dissolution. The stages of the study were as follows: Kuwu bledug mud was leached using aquadest at a ratio (g/ml) of 1: 2, a temperature of 40 °C, stirring speed of 200 rpm for 4 hours. The process was followed by partial evaporation up to 50% by volume and chemical precipitation using chemical reagents such as limestone and CaSO4 which was varied by 2, 4, 6 grams at 60 oC for 60 minutes. The results showed that the Bledug Kuwu mud could be used as a source of potassium fertilizer as had a potassium content of 58.08 ppm. Potassium levels increased to 220.52 ppm by partial evaporation. Potassium levels were reduced from 220.52 to 123.23 ppm with the addition of limestone. This indicates potassium precipitated into a solid K2O. Potassium levels increased from 123.23 to 589.14 ppm with the addition of 2 grams of CaSO4. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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42. Comparison of electricity generation from river soil with mud soil using sediment microbial fuel cell.
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Vishnupriya, Rajaram, Akash, S., and Ethiraj, Baranitharan
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MICROBIAL fuel cells , *ELECTRIC power production , *MUD , *SOILS , *POWER density , *SEDIMENTS - Abstract
The major aim of this study is to compare the power generation of river soil and mud soil using sediment microbial fuel cells (SMFC). Soil samples collected from river (N=60) and mud (N=60) were used to construct the SMFC and were operated for 20 hours (G power 80%). Multimeter was used to measure voltage, and current and power density was calculated for both the groups. The power generation was higher in river soil (63.8 mW/m2) as compared to mud soil (48.01 mW/m2). Independent sample T-Test showed that river soil power generation (P=0.004) was significantly higher compared with the mud soil. The study shows that higher power generation is possible with river soil compared to mud soil. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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43. Experimental Study on the Transmission Law of Ultrasonic in Mud
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Zhang, Shuo, Gao, Wen-kai, Teng, Xin-miao, Ding, Hua-hua, Liu, Ke, Yu, De-zhou, Wu, Wei, Series Editor, and Lin, Jia'en, editor
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- 2024
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44. The Soil of New Culture Studios: A Spring for African Architecture
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Brume, Jite, Perez, Alvaro Velasco, Nwoko, Demas, Thomsen, Mette Ramsgaard, editor, Ratti, Carlo, editor, and Tamke, Martin, editor
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- 2024
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45. Mud Acoustics.
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Holland, Charles W., Dosso, Stan E., and Chaytor, Jason D.
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- *
SPEED of sound , *ACOUSTIC wave propagation , *MARINE sediments , *ACOUSTICS , *BULK modulus , *MUD , *WEATHERING , *RAYLEIGH waves - Abstract
This article explores the significance of understanding mud acoustics for studying and operating in the ocean. Mud, a common sediment on the seabed, plays a crucial role in sound propagation in marine environments. The article discusses the various methods used to measure and infer the geoacoustic properties of mud, such as sound speed and density, through direct and remote sensing techniques. It also delves into the frequency and depth dependencies of mud acoustics and the challenges and limitations associated with measuring and modeling these properties. The authors emphasize the importance of comprehending mud's geoacoustic properties to gain a better understanding of the Earth's oceans. [Extracted from the article]
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- 2024
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46. In-situ wet carbonation activation of red mud waste for sustainable grout materials.
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Lu, Jian, Shen, Yuanyuan, Wang, Yuli, Zhang, Haibo, Guan, Xuemao, Zhu, Jianping, and Liu, Songhui
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CARBONATION (Chemistry) ,GROUTING ,MUD ,HYDRATION kinetics ,CARBON dioxide ,PORTLAND cement ,CONCRETE additives ,SILICA fume - Abstract
[Display omitted] • In-situ wet carbonation with CO 2 enhanced the chemical reactivity of RRM by altering its composition and microstructure. • CRM formed nano-CaCO 3 , amorphous silica/silica-alumina gels, increasing surface area and pozzolanic reactivity. • Using 30% CRM as cement replacement increased the 28-day compressive strength of the grout. • The study establishes the reuse of red mud waste in grouting enabled by CO 2 activation. The low reactivity and high alkalinity of raw red mud (RRM) limit its utilization as supplementary cementitious materials (SCMs) in Portland cement-based grouts. This work develops an in-situ wet carbonation technique to improve the chemical reactivity of RRM using flue gas CO 2. Systematic investigation of the RRM before and after carbonation revealed transformed composition and microstructure. The minerals and morphology changed significantly, with nano-CaCO 3 and amorphous silica/silica-alumina gels formation. This enhanced the pozzolanic reactivity of RRM. Detailed evaluation of the effects of carbonated red mud (CRM) as SCMs on the properties of Portland cement-based grouts showed accelerated hydration kinetics and refined pore structure. Replacement of 30% cement by the CRM increased the 28 d compressive strength of the grout. The underlying mechanisms were analyzed via XRF, XRD, TGA, FT-IR,
29 Si NMR, SEM, and N 2 adsorption–desorption testing. The nano-CaCO 3 and silica/silica-alumina gels from CRM participated in additional hydration and microstructure densification. This integrated approach enables the improved performance of grouting materials through CO 2 mineralization and industrial waste recycling. [ABSTRACT FROM AUTHOR]- Published
- 2024
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47. Hydrolysis of HFC-134a using a red mud catalyst to reuse an industrial waste.
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Kwak, In-Heon, Lee, Eun-Han, Kim, Jung-Bae, Nam, Sung-Chan, and Ryi, Shin-Kun
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INDUSTRIAL wastes ,WASTE recycling ,MUD ,CALCIUM aluminate ,CATALYTIC activity ,TRIGENERATION (Energy) - Abstract
• Red mud, an industrial waste, exhibits good catalytic activity in HFC-134a decomposition. • Red mud has superior durability in HFC-134a hydrolysis, and no AlF 3 or carbon is formed. • Tricalcium aluminate and gehlenite formed during heat treatment for long-term stability test enhanced the catalytic activity. Red mud obtained from industrial waste generated during the Bayer process was evaluated as a catalyst for the decomposition of hydrofluorocarbon-134a (HFC-134a), a greenhouse gas. The durability of the catalyst was evaluated through continuous operation for 66 h at 650 °C. The conversion of HFC-134a increased concurrently during the stability test, reaching ∼ 99 % after 50 h. After long-term testing, HFC-134a conversion over the red mud catalyst was evaluated as a function of temperature; an increase in the catalytic activity was observed over all temperature ranges. X-ray diffraction analysis revealed that tricalcium aluminate and gehlenite were formed during the long-term test, and the increase in the catalytic activity of the red mud could be attributed to the formation of a crystalline structure. Scanning electron microscopy/energy-disperse X-ray spectroscopy analysis confirmed that AlF 3 and carbon were not generated during the durability tests with high HFC-134a decomposition yield. Based on the HFC-134a decomposition tests and catalyst analysis, we conclude that the red mud catalyst has good catalytic activity and durability when used in HFC-134a decomposition. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
48. Extraction of Fe and Al from red mud using carbothermic reduction followed by water leaching.
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Cheema, Humma Akram, Ilyas, Sadia, Farhan, Muhammad, Yang, Ji-hye, and Kim, Hyunjung
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ALUMINUM oxide ,LEACHING ,MUD ,INDUSTRIAL metals ,FERRIC oxide ,IRON oxides - Abstract
[Display omitted] • A novel integrated process for maximum utilization of red mud was proposed. • Fe and Al were recovered by carbothermic reduction followed by water leaching. • The addition of Na 2 CO 3 helps improve magnetic yields and leaching efficiencies. • 92.5% Fe and 98.5% Al were recovered by recycling red mud. • Industrial metals were recovered and waste volume decreased by up to 32.6%. Red mud, a solid byproduct from bauxite ore processing for Al 2 O 3 production, encompasses valuable industrial metals, including Fe and Al. The objective of the present study was to investigate the feasibility of an integrated route for the efficient use of red mud for the multistep extraction of Fe and Al. Carbothermic roasting was performed in the presence of Na 2 CO 3 to reduce iron oxide to metallic iron. Optimal roasting conditions (reductant dosage: 1 g, temperature: 900 °C, time: 120 min, and charge ratio 10:5:1) yielded a 95.6 % recovery of the magnetic fraction. Applying a magnetic gradient of 0.1 T resulted in a 92.5 % recovery of metallic iron. Subsequent water leaching, performed under optimal conditions (time: 120 min, temperature: 70 °C, pulp density: 10 %), achieved a 98.5 % leaching efficiency of Al from a nonmagnetic fraction, with and without sodium carbonate, demonstrating 26 % efficiency. Incorporating sodium salt during carbothermic roasting facilitated the reduction of iron oxide to metallic iron and activated alumina for leaching. Finally, a value-added Al product, AlPO 4 , was precipitated from the leachate. This approach primarily attempts to contribute to a more circular economy, reducing waste and minimizing the environmental impact. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
49. Process and mechanism for synergistic treatment of spent carbon cathode and red mud by hydrothermal acid-leaching.
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Yang, Kai, Zhu, Xinye, Li, Hang, Zhang, Lele, Li, Jie, and Fang, Zhao
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LEACHING ,CHEMICAL process control ,CATHODES ,MUD ,ALUMINUM industry ,CHEMICAL reactions ,COORDINATION polymers ,ACTIVATION energy - Abstract
[Display omitted] • SCC and RM are synergistic treated by hydrothermal acid-leaching. • Thermodynamic calculation reveals the synergistic leaching mechanism. • The leaching rates of Fe and Al increased by 7.01 % and 8.66 %, respectively, compare with that of RM alone. • The activation energies of Al and Fe are 21.52 kJ/mol and 2.82 kJ/mol, respectively. Spent carbon cathode (SCC) and red mud (RM) are two kinds of solid wastes that are harmful to the environment and rich in valuable components from the aluminum industry. In this study, the valuable components of SCC and RM are co-treated by the hydrothermal acid-leaching. The synergistic treatment process is analyzed by phase characterization, thermodynamic calculation, single factor experiment, orthogonal experiment and kinetic study. The results show that the leaching of impurities by the synergistic treatment is better than that of hydrothermal acid-leaching alone. Under the optimal leaching conditions (liquid–solid ratio of 25 mL/g, temperature of 453 K, time of 270 min and acid concentration of 4 mol/L), the leaching efficiency of aluminum and iron reaches 89.70 % and 87.91 %, respectively. For aluminum, the time is the key factor affecting its leaching, the activation energy is 21.52 kJ/mol, and the leaching process is controlled by chemical reaction and solid product layer diffusion. For iron, the acid concentration is the key factor affecting its leaching, the activation energy is 2.82 kJ/mol, and the leaching process is controlled by the solid product layer diffusion. The leaching residue obtain by synergistic hydrothermal acid-leaching is C and SiO 2. This process provides a new solution for the treatment and recovery of SCC and RM. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
50. Growth and Development of Rhizophora spp. Seedlings on Different Substrates and Insertion Level in the Wouri Estuary Mangrove (Douala, Cameroon)
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Boubakary Boubakary, Essomè Koum Guillaume Léopold, Kottè Mapoko Ernest Flavien, Ngo-Massou Vanessa Maxemilie, Nyamsi Moussian Laurant, Konango Samè Alphonse, Emanè Jean Michel, and Ndongo Din
- Subjects
rehabilitation ,substrate ,sand ,propagules ,mud ,wouri estuary ,Environmental technology. Sanitary engineering ,TD1-1066 ,Environmental sciences ,GE1-350 - Abstract
Mangroves are threatened with extinction worldwide. Many mangrove reforestation projects have been developed, but very few have achieved their restoration objectives. With the ambitions to contribute for rehabilitation of mangrove ecosystems, the aim of this study was to assess the effects of substrate composition and level of insertion on the growth and development of Rhizophora seedlings in nurseries. The experiment was conducted in a semi-lighted nursery set up in situ. Rhizophora propagules were reared on three types of mangrove substrates (type 1:75% of mud and 25% of sand; type 2: 50% of mud and 50% of sand, and type 3: 25% of mud and 75% of sand) with different levels of insertion (at ¼; ½ and ¾). Seedling heights and diameters were recorded, as well as the time of appearance of the first leaves and the variation of number of leaves. The greatest average height (40.2 ± 7.48 cm) and the highest mean diameter (1.2 ± 0.01 cm) were obtained for the substrate composed of 75% mud and 25% sand. The best growth and development of seedlings were recorded on the substrate type 1 with an insertion at ¼. Seedling production at ¼ insertion of substrate type 1 appeared the most effective combination. The production of Rhizophora seedlings on the substrate combining 25% Sand and 75% Mud with an insertion level at 1/4 seems to be the best method for the complete restoration and rehabilitation of the mangrove ecosystem of the Wouri estuary.
- Published
- 2024
- Full Text
- View/download PDF
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