Residual Recovery Research Articles

Resource recovery of sludge incineration residue in lightweight aggregate: Performance mechanism, and environmental safety analysis

In response to escalating global environmental concerns and the need for sustainable waste management, this study explores the transformative potential of high-temperature sintering in converting sludge incineration residues (SIR) into lightweight aggregates. The research investigates the influence of sintering temperature and time on the physical, mechanical, and environmental characteristics of the resulting aggregates. High-strength lightweight aggregates with optimal properties are achieved at 1085 ℃ and 10 minutes, exhibiting favorable freeze-thaw resistance. Microscopic analyses reveal the presence of glassy substances in the aggregates, with higher sintering temperatures leading to increased glassy content but also more substantial pores. Importantly, high-temperature sintering significantly reduces the leaching rate of heavy metal ions. This study contributes valuable insights into the micro-characteristics and environmental safety of SIR-sintered lightweight aggregates, providing a sustainable solution for waste utilization in the development of high-performance construction materials.

Comparative study of urea-15N fate in pure bamboo and bamboo-broadleaf mixed forests.

Bamboo is a globally significant plant with ecological, environmental, and economic bene-fits. Choosing suitable native tree species for mixed planting in bamboo forests is an effective measure for achieving both ecological and economic benefits of bamboo forests. However, little is currently known about the impact of bamboo forests on nitrogen cycling and utilization efficiency after mixing with other tree species. Therefore, our study aims to compare the nitrogen cycling in pure bamboo forests with that in mixed forests. Through field experiments, we investigated pure Qiongzhuea tumidinoda forests and Q. tumidinoda-Phellodendron chinense mixed forests, and utilized 15N tracing technology to explore the fertilization effects and fate of urea-15N in different forest stands. The results demonstrated the following: 1) in both forest stands, bamboo culms account for the highest biomass percentage (42.99%-51.86%), while the leaves exhibited the highest nitrogen concentration and total nitrogen uptake (39.25%-44.52%/29.51%-33.21%, respectively) Additionally, the average nitrogen uptake rate of one-year-old bamboo is higher (0.25 mg kg-1 a-1) compared to other age groups. 2) the urea-15N absorption in mixed forests (1066.51-1141.61 g ha-1, including 949.65-1000.07 g ha-1 for bamboo and 116.86-141.54 g ha-1 for trees) was significantly higher than that in pure forests (663.93-727.62 g ha-1, P<0.05). Additionally, the 15N recovery efficiency of culms, branches, leaves, stumps, and stump roots in mixed forests was significantly higher than that in pure forests, with increases of 43.14%, 69.09%, 36.84%, 51.63%, 69.18%, 34.60%, and 26.89%, respectively. 3) the recovery efficiency of urea-15N in mixed forests (45.81%, comprising 40.43% for bamboo and 5.38% for trees) and the residual urea-15N recovery rate in the 0-60 cm soil layer (23.46%) are significantly higher compared to those in pure forests (28.61%/18.89%). This could be attributed to the nitrogen losses in mixed forests (30.73%, including losses from ammonia volatilization, runoff, leaching, and nitrification-denitrification) being significantly lower than those in pure forests (52.50%). These findings suggest that compared to pure bamboo forests, bamboo in mixed forests exhibits higher nitrogen recovery efficiency, particularly with one-year-old bamboo playing a crucial role.

Computer-aided framework for the design of entrainer for palm process residue recovery

Oleochemical industry produced substantial palm process residue during hydrogenation process of fatty acid/methyl ester, containing medium- to long-chain fatty alcohols and alkanes with overlapping boiling points. Recovering fatty alcohols for sale and utilizing alkanes for jet fuel, lubricants, and gasoline is beneficial. However, separating them through conventional distillation (CD) is challenging and expensive due to the difficulty in achieving the necessary temperature differentials for phase changes, especially with high reflux ratio required. To address this challenge, extractive distillation (ED) with an entrainer, designed through computer-aided molecular design (CAMD), was employed. However, implementing ED with a high boiling entrainer is challenging due to the high boiling point of the target components. Therefore, the design of the entrainer focused on the relative volatilities (α) of involved components and associated utility costs. Then, Aspen HYSYS was employed to evaluate the performance of the designed entrainer through product purity and economic analysis. For the separation of C10OH and n-C12, octane and dimethylcyclohexane were generated as entrainers. Dimethylcyclohexane entrainer demonstrated superior separation and generated higher profit than octane entrainer. For the separation of C12OH and n-C14, n-C15 was generated as entrainer to replace the infeasible CD. Therefore, the study concluded that ED with tailored entrainer can effectively replace CD for separating fatty alcohols from alkanes, demonstrating significant industrial feasibility.

Pulmonary perfusion defects or residual vascular obstruction and persistent symptoms after pulmonary embolism: a systematic review and meta-analysis.

Up to 50% of pulmonary embolism (PE) patients have perfusion defects or residual vascular obstruction during follow-up despite adequate anticoagulant treatment, and a similar percentage experience chronic functional limitations and/or dyspnoea post-PE. We aimed to evaluate the association between pulmonary perfusion defects or residual vascular obstruction and functional recovery after PE. We performed a systematic review and meta-analysis including studies assessing both the presence of perfusion defects or residual vascular obstruction and functional recovery (i.e. persistent symptoms, quality of life, exercise endurance). An odds ratio was pooled for perfusion defects or residual vascular obstruction and persistent symptoms using a random-effect model. 12 studies were included totalling 1888 PE patients; at a median of 6 months after PE (range 2-72 months), 34% had perfusion defects or residual vascular obstruction and 37% reported persistent symptoms. Among patients with perfusion defects or residual vascular obstruction, 48% (95% CI 37-60%, I2=82%) remained symptomatic during follow-up, compared to 34% (95% CI 20-51%, I2=96%) of patients without such defects. Presence of perfusion defects or residual vascular obstruction was associated with persistent symptoms (OR 2.15, 95% CI 1.66-2.78; I2=0%, τ=0). Notably, there was no association between these defects and quality of life or cardiopulmonary exercise test parameters. While the odds of having persistent symptoms was higher in patients with perfusion defects or residual vascular obstruction after acute PE, a significant proportion of these patients reported no limitations. A possible causality between perfusion defects or residual vascular obstruction and residual functional limitation therefore remains to be proven.

Stroke Recovery-Related Changes in Cortical Reactivity Based on Modulation of Intracortical Inhibition.

Cortical excitation/inhibition dynamics have been suggested as a key mechanism occurring after stroke. Their supportive or maladaptive role in the course of recovery is still not completely understood. Here, we used transcranial magnetic stimulation (TMS)-electroencephalography coupling to study cortical reactivity and intracortical GABAergic inhibition, as well as their relationship to residual motor function and recovery longitudinally in patients with stroke. Electroencephalography responses evoked by TMS applied to the ipsilesional motor cortex were acquired in patients with stroke with upper limb motor deficit in the acute (1 week), early (3 weeks), and late subacute (3 months) stages. Readouts of cortical reactivity, intracortical inhibition, and complexity of the evoked dynamics were drawn from TMS-evoked potentials induced by single-pulse and paired-pulse TMS (short-interval intracortical inhibition). Residual motor function was quantified through a detailed motor evaluation. From 76 patients enrolled, 66 were included (68.2±13.2 years old, 18 females), with a Fugl-Meyer score of the upper extremity of 46.8±19. The comparison with TMS-evoked potentials of healthy older revealed that most affected patients exhibited larger and simpler brain reactivity patterns (Pcluster<0.05). Bayesian ANCOVA statistical evidence for a link between abnormally high motor cortical excitability and impairment level. A decrease in excitability in the following months was significantly correlated with better motor recovery in the whole cohort and the subgroup of recovering patients. Investigation of the intracortical GABAergic inhibitory system revealed the presence of beneficial disinhibition in the acute stage, followed by a normalization of inhibitory activity. This was supported by significant correlations between motor scores and the contrast of local mean field power and readouts of signal dynamics. The present results revealed an abnormal motor cortical reactivity in patients with stroke, which was driven by perturbations and longitudinal changes within the intracortical inhibition system. They support the view that disinhibition in the ipsilesional motor cortex during the first-week poststroke is beneficial and promotes neuronal plasticity and recovery.

Bifunctional low molecular weight polyacrylic acid as aqueous binder and coating agent enables high performance LiMn2O4 cathode for lithium-ion batteries

LiMn2O4 is considered to be a promising cathode material for lithium-ion batteries due to its decent energy density, low price and environmental benignity. However, the problems of Mn dissolution, migration and deposition during the cycle, seriously affect its lifespan, especially at high temperature. In this study, we developed a strategy by which we killed two birds with one stone. A low molecular weight polyacrylic acid (PAA) mixed with sodium carboxymethyl cellulose (CMC) is applied as binder and coating agent for cathode particles at the same time. The conventional and environmental unfriendly polyvinylidene difluoride (PVDF)-N-methylpyrrolidone (NMP) system is replaced by the cheap and green aqueous binder with improved adhesive effect. Furthermore, the binder-based surface coating layer not only alleviates the side reaction between the electrolyte and the cathode particles, but also chelates the dissolved Mn2+ by the large amount of carboxyl groups in PAA molecules and so prevents the following migration and deposition of Mn2+. In the button half-cell with low molecular weight PAA based binder, the capacity retention reaches 94.1 % after 1000 cycles at room temperature and 92.0 % after 200 cycles at 60 degrees centigrade. Meanwhile, 18650-type cylindrical cells were prepared with this binder, which shows a great high temperature storage performance. After the cell was held at 60 degrees centigrade for 25 days at full charged state, the internal resistance increased by only 1.25mΩ, the voltage decreased by only 0.1 V, the residual capacity retention and recovery capacity retention reaches 85.6 % and 92.2 %. This work shows the great potential of the aqueous binder in dealing with the problem of Mn dissolution during the cycling of manganese-based cathode materials for lithium-ion batteries.

Study on harmless treatment and valuable elements recovery of neutralization residue from acid wastewater of copper mine

Recently, the common practice for treating metallurgical acidic wastewater involves neutralization with lime emulsion, resulting in residue that is typically landfilled or stockpiled. This contributes to long-term land occupation and environmental pollution. In this study, neutralization residue from a mine underwent comprehensive analysis using XRD, XRF, SEM-EDS, and other techniques. Utilizing acidic wastewater from the local mine as a leaching agent, the leaching characteristics of the residue were systematically investigated, and subsequent toxicity testing was conducted. Copper and iron, enriched in the leachate, were recovered employing the “pre-iron removal – sulfurization – pH compliance” process. Leaching experiments revealed the feasibility of mitigating toxicity by adjusting the pH of local mine wastewater (pH 1.5) with sulfuric acid and reacting with the residue at a ratio of 3:1 (mL/g), under conditions of 25 °C for 120 min. Under these optimized conditions, the recovery rates for Cu, Fe, As, Zn, and Ni reached 99.42%, 96.71%, 88.89%, 99.23%, and 98.21%, respectively. Toxicity testing classified the leaching residue as non-hazardous general solid waste for discharge. Recovery experiments demonstrated optimal conditions for the process, including pre-iron removal at pH 4, H2O2 10 mL/L 30 min, 25 °C, sulfurization with NaHS at 2 g/L, 20 min, 25 °C, and an emission process at pH 7.5, 60 min and 25 °C. The pre-iron removal residue (grade 45.54%) is conducive to entry into the iron plants for refinement processes aimed at enhancing its grade before entering the market, while the sulfide residue, with a copper grade of 57%, hold commercial potential. The remaining liquid adhere to established discharge standards. This process is characterized by a waste-to-waste and waste-to-treasure paradigm, demonstrating robust process stability.

New solutions for mechanized small diameter shaft sinking for residual oil production

The huge losses of oil in the subsurface necessitated the search for ways to extract residual oil, which led to the idea of combined use of the practice of mining and oil production. This involves drilling two vertical wellbores in the side rocks on the lying side of the oil reservoir, which are connected by two inter-hole joints. From the upper joint, a full series of wells pass along the entire strike of the formation at a certain interval with depth into the formation, into which steam supply pipes are placed with plugged ends at the bottom of the wells and lateral dispersed holes along their entire length. At the wellhead, these pipes are connected to individual high-pressure pulsating electric steam generators, and the wells themselves at the wellhead and the steam supply pipes are plugged. The electric steam generators are operated in line with a preset program. The most labor-intensive and costly in the idea of combined use of mining and oil production technologies is the sinking of vertical mine shafts, which requires new solutions in mine development technologies. In this regard, it is planned to reduce the cost of mining operations with the purpose of their use in oil production by means of non-explosive continuous mechanical-hydraulic pulse breaking of rocks of any strength and abrasiveness. Keywords: hydraulic pulse breaking of rocks; residual oil recovery technology; minimum diameter shaft sinking; two-jaw grab.

Optimized Design for Vibration Reduction in a Residual Film Recovery Machine Frame Based on Modal Analysis

The technology of plastic film mulching is widely applied in Xinjiang, but it also brings about serious issues of residual film pollution. Currently, the 1MSF-2.0 residual film recovery machine can effectively address the problem. However, it faces challenges such as high overall machine weight and noticeable frame vibrations, which affect the stability of the entire machine operation. The frame, as the installation foundation, needs to bear loads and impact. Therefore, the reliability of the frame is crucial for the stability of the entire machine. Improving the frame’s vibration is of great importance. In response to the significant vibration issues during the operation of the 1MSF-2.0 residual film recovery machine, this paper utilized Workbench 2020 R2 to establish a finite element model of the machine frame and conducted static analysis to obtain strength information, thereby initially understanding the optimization space of the frame. Building upon this, Mechanical was employed to solve the first 14 natural frequencies and mode shapes of the frame, and the accuracy of the theoretical analysis was verified through modal testing. After analyzing the frequency characteristics of external excitation forces, it was found that the fourth-order natural frequency of the frame fell within the frequency range of the excitation force of the shaft of the straw grinder, causing resonance in the frame and necessitating structural optimization. The optimal results indicated that the optimized frame increased in mass by 4.41%, reduced the maximum stress value by 2.56 MPa, and increased the fourth-order natural frequency to 22.7 Hz, avoiding the frequency range of the excitation force of the shaft of the straw grinder, thus improving the resonance issue. This paper provides a reference for optimizing the design of the frame of the residual film recovery machine.

Spectral exponent assessment and neurofilament light chain: a comprehensive approach to describe recovery patterns in stroke.

Understanding the residual recovery potential in stroke patients is crucial for tailoring effective neurorehabilitation programs. We propose using EEG and plasmatic Neurofilament light chain (NfL) levels as a model to depict longitudinal patterns of stroke recovery. We enrolled 13 patients (4 female, mean age 74.7 ± 8.8) who underwent stroke in the previous month and were hospitalized for 2-months rehabilitation. Patients underwent blood withdrawal, clinical evaluation and high-definition EEG at T1 (first week of rehabilitation) and at T2 (53 ± 10 days after). We assessed the levels of NfL and we analyzed the EEG signal extracting Spectral Exponent (SE) values. We compared our variables between the two timepoint and between cortical and non-cortical strokes. We found a significant difference in the symmetry of SE values between cortical and non-cortical stroke at both T1 (p = 0.005) and T2 (p = 0.01). SE in the affected hemisphere showed significantly steeper values at T1 when compared with T2 (p = 0.001). EEG measures were consistently related to clinical scores, while NfL at T1 was related to the volume of ischemic lesions (r = 0.75; p = 0.003). Additionally, the combined use of NfL and SE indicated varying trends in longitudinal clinical recovery. We present proof of concept of a promising approach for the characterization of different recovery patterns in stroke patients.

Computation and Communication Efficient Federated Learning With Adaptive Model Pruning

Federated learning (FL) has emerged as a promising distributed learning paradigm that enables a large number of mobile devices to cooperatively train a model without sharing their raw data. The iterative training process of FL incurs considerable computation and communication overhead. The workers participating in FL are usually heterogeneous and the workers with poor capabilities may become the bottleneck of model training. To address the challenges of resource overhead and system heterogeneity, this paper proposes an efficient FL framework, called FedMP, that improves both computation and communication efficiency over heterogeneous workers through adaptive model pruning. We theoretically analyze the impact of pruning ratio on training performance, and employ a Multi-Armed Bandit based online learning algorithm to adaptively determine different pruning ratios for heterogeneous workers, even without any prior knowledge of their capabilities. As a result, each worker in FedMP can train and transmit the sub-model that fits its own capabilities, accelerating the training process without hurting model accuracy. To prevent the diverse structures of pruned models from affecting the training convergence, we further present a new parameter synchronization scheme, called Residual Recovery Synchronous Parallel (R2SP). Besides, our proposed framework can be extended to the peer-to-peer (P2P) setting. Extensive experiments on physical devices demonstrate that FedMP is effective for different heterogeneous scenarios and data distributions, and can provide up to 4.1× speedup compared to the existing FL methods.

Intelligent residual film recovery machine monitoring and control system

Domestic residue recovery machines in China still follow the traditional towed mechanical model, lacking automation and intelligent features. Under the key R&D project of Xinjiang Autonomous Region, our team has developed integrated intelligent agricultural machinery for cotton straw crushing and residue recovery. This research covers the monitoring and control system, including PLC control and communication, working parameter monitoring and adjustment, algorithmic control of electro-hydraulic actuators, and human-machine interface display. Compared to traditional models, this machine replaces the conventional chain-driven mechanical structure and diesel tractor traction power with a fully hydraulic integrated suspension drive and power system. Sensors, PLC, and a touch screen are utilized for real-time monitoring and display of parameters. Hardware components like electromagnetic switch valves, electro-hydraulic proportional valves, hydraulic cylinders, and software elements such as PLC programs and intelligent control algorithms are employed for electro-hydraulic switching and proportional control of certain working parameters and mechanisms. All parameter information is consolidated in the PLC host and expansion modules and displayed and controlled on the human-machine interface. The system was installed on the first-generation machine for indoor testing, revealing that the monitoring and control system used on the first-generation machine achieves parameter detection and adjustment of the actuating mechanisms. It incorporates more advanced functions compared to traditional residue recovery machines. However, there is still ample room for improvement in the overall intelligence of the machine. The control system’s structure requires adjustment, and certain functionalities of the overall mechanical structure and working components need optimization or upgrading. Detailed enhancements to the entire system will be made in the next-generation machine.

Design and research of residual film pollution monitoring system based on UAV

To evaluate residual film recovery quality and rapidly monitor residual film pollution in agricultural fields, a residual film pollution monitoring system based on UAV, ground station, and cloud server was proposed in this research. It integrated a random sampling point generation (RSPG) algorithm and a key-lock pairing (KLP) algorithm for fast planning of flight paths, and used the U-Net model to rapidly segment residual films from images and calculate residual film coverage. The results showed that the average deviation between the actual distance and the ideal distance of the randomly generated sampling points using the RSPG algorithm was 0.0733 m, and the average deviation of the azimuth angles was 0.2°. The KLP algorithm significantly reduced path planning time, while maintaining a high shortest path rate and reducing memory consumption. The U-Net model achieved an optimal mean intersection over union (MIOU) of 85.63 % on the test set. The simulation and field verification of the system found that automatic UAV path planning and rapid residual film image segmentation were achieved. The coefficient of determination (R2) between the predicted values and the manually labelled values was 0.966, and the root-mean-square error (RMSE) was 0.1173 %. The average relative error between the predicted residual film coverage and the manually labelled coverage was 11.55 %, and the average detection time of the monitoring system was 422.6 s. Therefore, the UAV-based residual film pollution monitoring system can realize integrated automatic sampling and rapid residual film pollution assessment. This study provides technical support for accurate assessment and control of residual film pollution.

Recycling primary lithium batteries using a coordination chemistry approach: recovery of lithium and manganese residues in the form of industrially important materials.

In this study, we have investigated the potential use of post-consumer primary lithium metal batteries (LMBs) commonly used in portable electronic devices to recover lithium and manganese in the form of industrially important materials. A direct reaction of lithium-containing electronic waste with a naturally sourced ester, methyl salicylate, combined with a wide range of aliphatic alcohols has been used as a general method for recovering lithium in the form of lithium aryloxides of different nuclearities [Li(OAr)(HOMe)2] (1), [Li(OAr)(HOAr)] (2), [Li(OAr)(HOEt)]2 (3), [Li(OAr)(H2O)]2 (4), [Li4(OAr)4(EGME)2] (5), [Li6(OAr)6] (6-8) for ArOH = methyl salicylate (1, 2, 4, 6), ethyl salicylate (3, 7), 2-methoxyethyl salicylate (5, 8), and EGME = 2-methoxyethanol. The hydrolysis of 7 was then used to synthesize lithium salicylate [Li(Sal)(H2O)]n (10), which is an important antioxidant in the production of oils and grease. The discharged cathode material of Li-MnO2 batteries was investigated as a source from which LiClO4, Li2CO3, LiMn2O4, and Mn2O3 can be recovered by means of water-alcohol extraction or calcination. Particular emphasis was placed on the detailed characterization of all battery components and their decomposition products. LMBs were completely recycled for the first time, and materials were recovered from the cathode and the anode.

Forensic Analysis of Recrystallized Inorganic Oxidizing Salts Used in Pyrotechnic-Based Improvised Explosive Devices Using Light Microscopy and Micro-Raman Spectroscopy

This study aimed to evaluate the advantages and challenges of analyzing post-blast pyrotechnic pipe bombs using a combination of light microscopy and micro-Raman spectroscopy. Two simulated improvised explosive devices (IEDs) were constructed and exploded using pyrotechnics as the main charge and consisted of several different components to simulate common materials that might be found in authentic bombing scenarios. In order to develop a rapid explosives residue recovery technique, a wet and dry swabbing process was compared to determine the most efficient swabbing method of recovery for inorganic oxidizers in post-blast debris. Samples were recrystallized using a water recrystallization method followed by in situ analysis using polarized light microscopy (PLM) and micro-Raman spectroscopy, targeting euhedral and subhedral crystals. While the water recrystallization had effects on the resulting Raman spectrum, such as peak intensity reduction, ultimately, the final salt identifications were not affected. The detection of several inorganic oxidizers post-blast included the identification of potassium perchlorate (KClO4), potassium nitrate (KNO3), and barium nitrate (Ba(NO3)2). The detection of KNO3 using microscopy alone was more challenging due to its relatively low abundance compared to KClO4 but was achieved with micro-Raman spectroscopy. Additionally, the mixing of inorganic oxidizers within single crystals was also observed. The results indicated that the combined approach of microscopy and micro-Raman spectroscopy enabled the successful detection of inorganic oxidizing salts in a post-blast scenario, as well as describing the advantages and limitations of this combination of techniques.

Recovery of Crop Residues in the Feed of N'Dama Dairy Cows in Periods of Last Food in Modiya Urban Commune of Faranah

In order to evaluate the effects of supplementation of N'Dama dairy cows through potato vines (V1 = 366 kg) and rice straw (V2 = 366 kg) in times of scarcity, a trial was set up in Modiya, from March 3 to April 28, 2023 with 18 dairy cows from the 4th and 5th lactation divided into three (3) variants (V0; V1 = supplemented with potato vines; V2 = supplemented with straw rice) with (3) repetitions (R1, R2, R3) in a random block with simple classification. Each animal received its supplementary ration once a day after milking. A weekly milk sample for eight (8) weeks provided the average production: V0 = 13.67; V1 = 16.20 and V2 = 18.44 liters. A chemical analysis of the milk gave the protein and fat levels which are respectively for V0: 4.48 and 3.20%; V1: 7.10 and 3.90%; V2: 5.60 and 3.89 %. The results show that in Modiya supplementation increased the quantity and quality of the milk of the cows which received the supplement compared to the control group.

Organic residue analysis in archaeological pottery. Heating markers in non-cooking vessels from Etruscan Tarquinia (Italy): A sampling problem?

The organic residues in the material of a series of pottery vessels from a votive deposit (3rd − 2nd century BCE) in the excavations of the Etruscan city of Tarquinia (Italy) were analyzed by gas chromatography – mass spectrometry (GC–MS). Long-chain (31, 33 and 35 carbon atoms) ketones were initially detected in the lipid extracts of all the ceramic samples examined, irrespectively of the characteristics of the vessels in terms of shape and texture and of the possibility they had been used for cooking, recognized in several studies as the main cause of the formation of these compounds. Considering that some cases have also been reported in the literature in which the presence of these ketones seemed unexpected for a given ceramic container, it was decided to examine the possible correlation of their occurrence, for the set of vessels examined in the present work, with the sampling mode used to obtain the ceramic powder before extraction with solvents for the recovery of the organic residue. It was thus possible to demonstrate that the use of a drill for sampling, a modality not unusual in this kind of study, can give rise to the formation of these compounds in an archaeological ceramic material in which fatty acids are absorbed, particularly if it contains calcium carbonate, as demonstrated by X-ray diffraction (XRD) analysis of the examined pottery fragments. A laboratory experiment based on a fragment of modern pottery in which palmitic and stearic acids were absorbed from a solution, and from which powder samples were then obtained both by drilling and by manual scraping of the pottery surface, allowed to validate the hypothesis above. It was therefore possible to highlight the importance of careful consideration also of the sampling phase in interpreting the results of the analysis of organic residues in archaeological pottery.

Enhancing flotation recovery of residual carbon from gasification waste by mixing hydrophobic powder with diesel as collector

Coal gasification fine slag (CGFS) is a solid waste containing residual carbon and ash generated during the coal gasification process, and the separation of the two components is the essential way to realize its environmental pollution reduction and resource value increase. Froth flotation is the preferred method for separating CGFS, but there is a barrier of low carbon recovery in this process due to the extensive adsorption of collector by the well-developed pores on residual carbon. In this study, a sufficiently simple yet innovative collector, a mixture of hydrophobic powder and diesel, was proposed in an attempt to break the bottleneck. Flotation experiments with common diesel and this novel collector were performed respectively, and FTIR, XPS, and SEM-EDX were employed to analyze the collector action mechanism. Flotation results revealed that the novel collector could significantly improve the residual carbon recovery; test results demonstrated that the novel collector could increase the hydrophobic functional group content on the fine slag surface, and the hydrophobic powders in this novel collector mainly appeared at the pore openings of the flotation concentrate. The essence of the mechanism is that the hydrophobic powders play a dual role of blocking pores and providing adsorption sites, thus facilitating the spreading of diesel on the carbon surface and promoting its floatability. The study can provide creative ideas for the efficient disposal of coal gasification waste.

Numerical Simulation Study on Parameter Optimization of In-depth Fluid Diversion in Low-permeability Fractured Reservoir

Daqing Chaoyanggou Oil Field is a low-permeability fractured oil reservoir that has entered into the middle and high water-cut periods of waterflooding extraction. Now, the moisture content is 74.88% and the injected water flows along fractures. The moisture content of oil wells increases quickly, accompanied with relatively serious invalid waterflooding. The in-depth fluid diversion can be used to exploit residual oil in substrate effectively and thereby increase recovery efficiency of the low-permeability fractured oil reservoir. In this study, parameters of in-depth fluid diversion in low-permeability fractured reservoirs can be optimized by numerical simulation method. According to geologic characteristics and fracture development situations in the study area, a geologic model of the study area was constructed. A historical fitting of exploitation indexes was carried out to optimize the dosage, injection rate and injection time of control-displacement agent during in-depth fluid diversion. Results demonstrated that the optimal dosage, the optimal injection rate and the optimal injection time of the control-displacement agent were 0.1 ∼ 0.15PV, 0.03 ∼ 0.04PV/a and about 70% of comprehensive moisture content, respectively. This study can provide reference to residual oil recovery in low-permeability fractured reservoirs during middle and high water-cut periods.

Data-driven interpretable analysis for polysaccharide yield prediction

Cornstalks show promise as a raw material for polysaccharide production through xylanase. Rapid and accurate prediction of polysaccharide yield can facilitate process optimization, eliminating the need for extensive experimentation in actual production to refine reaction conditions, thereby saving time and costs. However, the intricate interplay of enzymatic factors poses challenges in predicting and optimizing polysaccharide yield accurately. Here, we introduce an innovative data-driven approach leveraging multiple artificial intelligence techniques to enhance polysaccharide production. We propose a machine learning framework to identify highly accurate polysaccharide yield prediction modeling methods and uncover optimal enzymatic parameter combinations. Notably, Random Forest (RF) and eXtreme Gradient Boost (XGB) demonstrate robust performance, achieving prediction accuracies of 93.0% and 95.6%, respectively, while an independently developed deep neural network (DNN) model achieves 91.1% accuracy. A feature importance analysis of XGB reveals the enzyme solution volume's dominant role (43.7%), followed by time (20.7%), substrate concentration (15%), temperature (15%), and pH (5.6%). Further interpretability analysis unveils complex parameter interactions and potential optimization strategies. This data-driven approach, incorporating machine learning, deep learning, and interpretable analysis, offers a viable pathway for polysaccharide yield prediction and the potential recovery of various agricultural residues.