Process Flow Research Articles

Recovery of secondary resource rare earth bearing Indian beach placer garnet and value addition

ABSTRACT The garnets extracted from the coastal region belong to the almandine variety and are available in sizes exceeding + 80#. The size fraction below 80# is discarded at mineral separation plants, resulting in the accumulation of garnet piles, which contribute to air pollution affecting workers. Consequently, any initiative to utilize these finer garnets aligns with transforming waste into wealth. This study focuses on recovering and enhancing rejected-size garnets from the Ramchandi coast in Odisha, India. The extraction process from the beach sand employs wet and dry methods, followed by screening. The findings indicate that the optimal product achieved contains 99.1% garnet, with a recovery rate of 92.8% and a yield of 38.2%, utilizing a combination of spiral concentrators, wet high-intensity magnetic separators, and high-tension separators. The recovered garnets, being of the almandine variety, have a broad spectrum of industrial applications, including the extraction of rare earth elements and the production of industrial precipitated silica. This study aims to develop a process flow sheet for the value addition of waste-sized garnets, targeting the concurrent recovery of rare earth elements such as rare earth hydroxide concentrate, hydrated alumina, precipitated silica, and calcium carbonate. This process seeks to minimize the presence of iron, alumina, and other undesirable impurities in the fine-sized waste garnet, which can be utilized in various commercial applications, such as reinforcing agents in rubber manufacturing, cosmetics, toothpaste, and anti-caking agents in the food industry.

Radical Islam in Kyrgyzstan

In the last approximately 10–15 years or so, the tendencies towards radical Islamization of Kyrgyzstan have intensified, although it is not so much the Kyrgyz as the Uzbeks and Uighurs who are more susceptible to it. However, the process is gaining momentum among the Kyrgyz as well. There are several reasons for this: socio-economic problems, insufficient work with the population of traditional Islamic structures, the process of flow from the south to the north, in relation to Kyrgyzstan, expressed in the departure of the European population and the influx of visitors from more southern states, including carriers of radical Islam. Among the latter, immigrants from Pakistan are the most active, but missionaries from the Persian Gulf and Turkey are active too. Among other things, many political parties of Kyrgyzstan, some of which directly call for the abolition of the constitutional norm on the secular nature of the Kyrgyz state, have begun to actively cooperate with radical Islamists. Christian religious structures also do not work enough with the titular population of Kyrgyzstan, either because of unwillingness to work (Orthodox), or because of the negative attitude of the authorities (Protestants). In the latter case, it is necessary to point out some laws of Kyrgyzstan that do not strike at Islamic radicals, against whom they seem to be aimed, but just at those who could resist them. Nevertheless, the situation does not seem hopeless yet and can be corrected.

A quality improvement initiative to improve growth monitoring of children attending immunization clinic in an urban primary health centre in Delhi

BackgroundImmunization clinics present an opportunity for passive screening for malnutrition among young children through plotting of growth charts. Passive screening for malnutrition can enable timely interventions and improve morbidity and mortality of under-five children. Therefore, we aimed to increase the plotting of growth charts (weight-for-age) to 90%, among under-five children attending immunization clinics in an Urban Health Centre (UHC) in south Delhi over three months.MethodologyA Quality Improvement (QI) initiative was undertaken in the immunization clinic of an urban primary health centre in southern Delhi, from January to March 2024. A multi-faceted QI team was formed. The baseline coverage of weight-for-age growth chart plotting in the immunization clinic was 31%. The process flow was mapped, and critical gaps identified by root cause analysis (Fish Bone technique). Change ideas were discussed and prioritized using a prioritization matrix to implement these through sequential PDSA cycles. The main change ideas implemented were training of health workers, allotting regular supervisors for the session, and appending a stamp for quick identification of underweight children. Run chart was used to assess the changes over time. We considered the outcome achieved if the plotting coverage was more than 90% sustained for at least six consecutive immunization sessions.ResultsMultiple change ideas were implemented over a period of three months. The coverage of growth chart plotting increased to more than 90%. Lack of motivation among stakeholders was a challenge for some change ideas. Monitoring of immunization sessions for plotting of growth chart was continued post the implementation of all change ideas to assess sustainability which showed positive results. Post-implementation of the change ideas, a meeting was held with the members of the QI team to get feedback on this activity.ConclusionThere is potential for improving growth monitoring at immunization clinics, which can be beneficial in strengthening passive screening for malnutrition in primary care settings.Clinical trial numberNot applicable.

Dielectrically Monitored Flow Synthesis of Functional Vaccine Adjuvant Mixtures via Microwave-Assisted Catalytic Chain Transfer Processing

A novel flow process to produce low-molecular-weight (Mwt) methacrylate oligomer mixtures that have potential as vaccine adjuvants and chain transfer agents (CTAs) is reported. The chemistry and process were designed to significantly reduce the number of stages required to manufacture methyl methacrylate oligomer-in-monomer mixtures with an oligomer Mwt range of dimers to pentamers and >50% conversion. Combining rapid in-flow, in situ catalytic chain transfer polymerization catalyst synthesis and volumetric microwave heating of the reaction medium resulted in catalyst flow synthesis being completed in <4 min, removing the need to pre-synthesize it. The steady-state operation was then successfully maintained with very low levels of external energy, as the process utilized the reaction exotherm. The microwave process outperformed a comparative conventionally heated system by delivering a 20% increase in process throughput with no change in final product quality or conversion. Additionally, combining flow and in situ catalyst processing enabled the use of a more oxidatively unstable catalyst. This allowed for in situ catalyst deactivation post-generation of the oligomers, such that residual catalyst did not need to be removed prior to preparing subsequent vaccine adjuvant or CTA screening formulations. Finally, dielectric property measurements were able to monitor the onset of reaction and steady-state operation.

Dynamic Simulation of Photothermal Environment in Solar Greenhouse Based on COMSOL Multiple Physical Fields

Solar greenhouses are essential facilities for agricultural production in northern China, where uneven internal environments pose significant challenges. This study established a numerical model of photothermal conditions in solar greenhouses. Utilizing COMSOL MultiphysicsTM, we established a microclimate model that encompasses the greenhouse exterior and the soil directly below it, without considering the crops. This model coupled multiphysical fields with fluid flow and heat transfer processes. The boundary conditions and initial values of the external environment and soil were derived from meteorological data and an efficient interpolation function method, with the time step updated every 1h. The results demonstrate that the simulated values were in good agreement with the measured values. Our findings reveal the temporal dynamics of radiation and temperature changes, as well as spatial heterogeneity, within solar greenhouses under different winter weather conditions. Additionally, the potential of integrating with other real-time monitoring and control models was discussed. This study provides a theoretical foundation for developing microclimate models and predicting photothermal environments in greenhouses.

Tracing metal sources and groundwater flow paths in the Upper Animas River watershed using rare earth elements and stable isotopes

Groundwater flow paths and processes that govern metal mobility and transport are difficult to characterize in mountainous bedrock watersheds. Despite the difficulty in holistic characterization, conceptual understanding of subsurface hydrologic and geochemical processes is key to developing remediation plans for locations affected by acid mine drainage, such as the Upper Animas River watershed in southwestern Colorado, USA. Stable isotopes of water and rare earth elements were utilized to evaluate groundwater flow and metal sources within this complex catchment. Stable isotope samples collected from draining mine adits and springs display systematic spatial variation wherein sample sites at higher elevations have greater seasonal variability than sites at lower elevations. The Upper Cement Creek watershed, where multiple draining mines are present, displays the lowest seasonal variation in stable isotopic signatures, potentially indicating the presence of a large, well-mixed volume of groundwater storage or interbasin groundwater flow. Rare earth elements display statistically significant variation between different alteration styles in the catchment. Overprinting of regional propylitic alteration is evident based on enrichment of middle rare earth elements in acidic springs and mines that are not spatially associated with surficial exposures of acid generating alteration styles. Europium anomaly and middle rare earth enrichment signatures from two flooded mine tunnels on opposite sides of a watershed divide indicate connections to the same subsurface flooded mine workings.

Developing a cost-effective and efficient safety case management solution for data coordinating center projects.

A centralized safety function can support multiple clinical trials and provide efficient, standardized processes for the management of serious adverse events. From 2017 to 2022, the centralized safety desk used pharmacovigilance software compliant with FDA regulations, including 21 CFR Part 11. This software assisted with processing safety cases for regulated clinical trials, including allowing capture of event data, and provided process flow management, documentation storage, and transmission of safety reports to FDA. During the software's tenure, we experienced incompatibilities with other clinical research software resulting in unanticipated inefficiencies. Furthermore, the small number of periodic and suspected unexpected serious adverse reaction (SUSAR) cases rendered the annual license fee not cost-effective. An internal analysis of our workflow, systems, and processes revealed that developing a cost-effective and efficient customized solution for our existing data coordinating center (DCC) projects was feasible. The customized solution mimics the key functionality and workflow of the prior software. It utilizes existing electronic data capture systems and document management solutions, ensuring 21 CFR Part 11 compliance without incurring additional expenses. The proposed process received internal approval and launched in December 2022. The process outlined in this paper is particularly advantageous for DCCs or academic clinical research sites that must meet regulatory reporting requirements without depending on specialized pharmacovigilance software. Additionally, it is a cost-effective option for organizations with a low volume of SUSAR events. In this paper, we present the process of developing and implementing a customized safety case management solution and the lessons learned pre and post implementation.

A Unified Model of Natural Evolution and the Crises in Particle Physics and Cosmology

A unified model of the evolution of the universe is presented. The model consists of four stages: Planckian, Einsteinian, Darwinian, and Intellectual. The evolution of the universe is described as a single flow of information processing that begins at the Planckian stage and continues into the emergence of the most complex information processor: the human brain and the technologically developed human civilization. Each stage has its own structural and functional unit, carriers of evolutionary information, and driving evolving objects. The Planckian stage is described as a system of quantum-mechanically entangled PlanckITs: an entity that represents existence in a randomized space and randomized time. The space-time continuum is presented as a collection of addressable PlanckYTEs. APlanckYTE contains a fixed number of PlanckITs. In the Einsteinianstage, the leptons and quarks of the latest appeared generation carry the information that define the conditions for the transition to the Darwinian stage. Leptons and quarks code a set of parameters that define the conditions for the origin of life and its subsequent evolution. The following expression: ME = (9ℏc3)/(2αGkTE) is one of the results that supports this fact. The Darwinian stage describes biological evolution. The intellectual stage uses the concepts of life symmetry and intellectual fields to describes the intellectual or cultural evolution of social systems. This paper is the first of three papers: ”A Unified Model of Natural Evolution and the Crises in Particle Physics and Cosmology”; ”Space and Time at Planck’s Scale, Carriers of the Evolutionary Information, and the Evolution of the Universe”; ”Evolutionary Anthropodynamics: The Evolution of Intellectual Systems”. Some calculations are done to support the unified model of natural evolution.

Multi-source Semi-supervised Condition Constrained Domain Adaptation for Process Fault Classification

Abstract To address inconsistent feature distributions caused by multiple working conditions in industrial processes and the lack of fault type labels, this paper proposes a Multi-source semi-supervised conditional constraint domain adaptation (MSSCCDA) fault classification method. Data from multiple working conditions are divided into multiple source domains and a target domain. A Convolutional neural network (CNN) extracts features from the multi-source domain data, and a triplet loss method reduces the feature distance between the same categories in different source domains. A semi-supervised conditional constraint domain adaptation method is proposed, which combines adversarial domain adaptation with a limited amount of labeled target domain data to pre-train the feature extractor. During adversarial training, center loss regularization is introduced as a conditional constraint for class feature alignment. The process of optimizing the feature extractor involves jointly leveraging adversarial loss to reduce inter-domain discrepancies between the source and target domains and minimizing class differences within target domain. Experiments conducted on the Tennessee-Eisman (TE) process and industrial three-phase flow (TFF) show that the average accuracy improves to 93% and 93%, respectively. The effectiveness of the proposed method is further validated through a comparison with two traditional domain adaptation approaches and five multi-source domain adaptation techniques.

Theoretical Calculation of Heat and Material Balance for Oil Sludge Pyrolysis Process by Solid Heat Carrier Method

In this study, oil sludge from Jilin Petrochemical of China was selected to carry out the Fischer assay and proximate analysis. According to the properties of the Jilin oil sludge and its pyrolysates, the material and heat balance of the pyrolysis process was deduced theoretically based on 1000 kg of received base oil sludge. The results show that the solid heat carrier method can be used in the pyrolysis of oil sludge, and a new process flow is proposed. According to the heat required and heat provided in the rotary reactor and in the fluidized bed, 5940 kg of ash was needed as a solid heat carrier, and 25 kg of liquefied petroleum gas was needed as a supplementary fuel besides the semi-coke and retorting gas. The total input heat and output heat were 13.65 GJ and 10.04 GJ. The loss was 3.61 GJ and the thermal efficiency was 73.6%.

Effects of Machining Parameters on Abrasive Flow Machining of Single Crystal γ-TiAl Alloy Based on Molecular Dynamics.

Observing the intricate microstructure changes in abrasive flow machining with traditional experimental methods is difficult. Molecular dynamics simulations are used to look at the process of abrasive flow processing from a microscopic scale in this work. A molecular dynamics model for micro-cutting a single crystal γ-TiAl alloy with a rough surface in a fluid medium environment is constructed, which is more realistic. The evolution of material removal, cutting force, temperature, energy, and dislocation during micro-cutting are analyzed. The impact of cutting depth, abrasive particle sizes, and abrasive material on the micro-cutting process are analyzed. The analysis shows that the smaller cutting depth and abrasive particle sizes are beneficial to obtain a better machining surface, and the cubic boron nitride (CBN) abrasive is an effective substitute material for diamonds. The purpose of this study is to provide unique insights for improving the material removal rate and subsurface quality by adjusting machining parameters in actual abrasive flow precision machining.

Characteristics of water distribution and preferential flow processes and nutrient response on dolomite slopes in the southwestern karst region

Understanding the characteristics of the soil water content and preferential flow is critical for a thorough comprehension of soil nutrient loss in Karst slopes/ecosystems. We monitored the soil water content and soil temperature at 0–20, 20–40, and 40–60 cm depths on a typical Karst dolomite slope at a high frequency to determine the water distribution characteristics and confirm the occurrence of preferential flow from 2018 to 2021. The soil properties and nutrients in different soil layers during the rainy and dry seasons were determined along the slope (from upper to lower slope positions, with a total of 9 sampling sites). The results revealed that the saturated hydraulic conductivity of the soil at the upper slope position was significantly (p < 0.05) greater than that at the middle and lower slope positions. The soil water content at the down slope position was greater than that at the middle and upper slope positions, further more, coupling monitoring of the soil water content and temperature revealed obvious preferential flow in the Karst dolomite slope. In addition to the spatial variability in the water content, the soil nutrients exhibited regular spatial variations. The dissolved organic carbon (DOC), dissolved organic nitrogen (DON), total nitrogen (TN), total phosphorus (TP) and total potassium (TK) contents were the lowest at the upper slope position and the highest at the down slope position, whereas the difference in nutrients between the rainy and dry seasons was the greatest at the upper slope position. Our results demonstrated that the patterns of the soil water content and surface nutrient loss are consistent along the Karst dolomite slope and are related to the occurrence of preferential flow. Furthermore, the results suggested that, compared with those in previous studies, which focused only on soil properties in the Karst regions of Southwest China, the variation in the soil water content and occurrence of preferential flow may be more important than previously assumed.

Study on physical clogging process and practical application of horizontal subsurface flow constructed wetland

In view of the urgent concerns pertaining to the proliferation of rural wastewater discharges and the imperative for decentralized treatment, this article examines the phenomenon of physical clogging in a small-scale horizontal submerged flow artificial wetland system. Through a combination of experimental analysis and CFD-EDM numerical simulations, the impact of clogging on the hydraulic efficiency of the system was subjected to rigorous examination. Based on these findings, an innovative design strategy was proposed, namely the addition of vertical baffles. The experimental results demonstrate that this strategy can markedly prolong the duration of complete clogging of the system by up to 15% and enhance the hydraulic efficiency by 21%. Based on this, a small-scale horizontal submerged artificial wetland wastewater treatment system was designed for rural areas and successfully implemented in Fanrong Village, Rui’an City. This resulted in an enhanced wastewater treatment effect and an improved rural landscape. The findings of this study contribute to the development of a more rational and effective sewage treatment solution for rural areas.

Vector-Time-Resolved In-plume Plasma Current Density Flux Measurement in a Pulsed Plasma Thruster

Plasma plumes are the end products ejected from electric propulsion after complex ionization and acceleration processes. The physics behind the plasma plumes has attracted significant interest due to their interactions with the critical components of satellites and an increased understanding of the relevant processes. Recently, in the front view from a pulsed plasma thruster (PPT), we observed an unclosed vortex structure in the plasma plume, which led us to reconsider the propagation process and the current flux directions inside a plasma plume. To study this plume structure in depth, a highly sensitive Rogowski coil is used here to obtain the current density of the plume over the operating period of a PPT in 3 perpendicular directions. Vector-time-resolved current flux maps were obtained through experimental measurements and the peak current densities were found to reach 50000 mA/cm2 to 250000 mA/cm2. From successive 3-D current flux maps, the complete process of current flow inside a transient plasma plume is observed. The vortex plume structure was found to form during the initial discharge period. The plasma in-plume current is shown to be involved by discharge circuit. After the main discharge is completed, the plasma plume tends to circuit-independent and in self-equilibrium.

Modeling the composite fuel’s flow and combustion process in a combined burner device

Modeling the composite fuel’s flow and combustion process in a combined burner device

Clustering time-evolving networks using the spatiotemporal graph Laplacian.

Time-evolving graphs arise frequently when modeling complex dynamical systems such as social networks, traffic flow, and biological processes. Developing techniques to identify and analyze communities in these time-varying graph structures is an important challenge. In this work, we generalize existing spectral clustering algorithms from static to dynamic graphs using canonical correlation analysis to capture the temporal evolution of clusters. Based on this extended canonical correlation framework, we define the spatiotemporal graph Laplacian and investigate its spectral properties. We connect these concepts to dynamical systems theory via transfer operators and illustrate the advantages of our method on benchmark graphs by comparison with existing methods. We show that the spatiotemporal graph Laplacian allows for a clear interpretation of cluster structure evolution over time for directed and undirected graphs.

A universal framework for design and manufacture of deterministic lateral displacement chips.

Despite being a high-resolution separation technique, deterministic lateral displacement (DLD) technology is facing multiple challenges with regard to design, manufacture, and operation of pertinent devices. This work specifically aims at alleviating difficulties associated with design and manufacture of DLD chips. The process of design and production of computer-aided design (CAD) mask layout files that are typically required for computational modeling analysis, optimization, as well as for manufacturing DLD-based micro/nanofluidic chips is complex, time-consuming, and often necessitates a high level of expertise in the field. Herein, we report a universal framework to automate the process of designing DLD and producing layout CAD files for various systems spanning from simply a single DLD unit to complex parallelized DLD structures with/without additional upstream/downstream components, e.g., inlet filter, preload, collection channels, and through-wafer vias. In addition, to the best of our knowledge, for the first time, we adopt imprint lithography (IL) into fabrication process flow to define fine features of parallelized DLD arrays, while avoiding problems in connection with accessibility and cost of advanced photolithography tools. With regard to parallelized DLD architectures, we also report a new fabrication process flow aiming at mitigating the problems related to creating through-silicon vias at high yield. We demonstrate some use cases of our developed design and manufacture framework by designing and fabricating multiple devices to separate microspheres (0.6 μm and 1.3 μm) from aqueous media. We believe that our design automation package offers a user-friendly workflow, significantly alleviating the hurdles associated with design and optimization of DLD structures, while our fabrication process flow can provide an accessible solution to manufacturing micron- and submicron-scale DLD chips. These innovations should enable a larger community to adopt the DLD technology into their research, particularly for lab-on-a-chip applications.

Production of calcined eggshell: Process description and economic analysis

Adsorbents derived from eggshell (ES) have been proven to be effective for a variety of pollutants including organic and inorganic pollutants from different types of wastewater. Calcined eggshell (CES) had demonstrated a significant performance in which are on par with or even exceeds the commercially available adsorbents for phosphorus removal or recovery. This study aims to develop the process flow diagram for large scale production of CES with an overall economic analysis. A process flow diagram was developed starting from the transportation to storage of final product, CES. Calculation of process parameters were based on 1,000kg ES/day with 50% yield after the calcination process, generating about 475 kg CES/day. The total production cost was RM542,809.82 for producing 148, 675 kg of CES per annum. Based on these values, the cost of CES production per kg was estimated as RM3.58 or 0.76 USD. There is a great potential for CES in the future for the remediation of water and air pollutants.

Depolymerisation of poly(lactide) under continuous flow conditions.

Poly(l-lactic acid) (PLLA) is commercially successful bio-based plastic, where end-of-life materials can undergo industrial composting. To create a circular economy, a desirable alternative to composting is chemical recycling to monomer (CRM), where direct depolymerisation to l-lactide can be achieved. CRM of PLLA is typically impeded by thermal decomposition and side reactions, due to the high ceiling temperate (T c) of PLLA in bulk (>600 °C), which preclude implementation on a large scale, and has led to the development of catalytic strategies, under vacuum or high dilution in high boiling point solvents conditions. In this study, a commercially available Sn(ii) catalyst and low boiling point solvents, at a range of temperatures and concentrations, were explored for the CRM of PLLA in a continuous flow process. The solvent THF was found to produce the best results, where up to 92% conversion of lactide could be achieved, with 92-97% selectivity for l-lactide formation at temperatures 150-170 °C. Further, inline monitoring of monomer and polymer concentrations in flow were used to determine the depolymerisation rate coefficient k depo and the activation energy of k depo was determined to be 129.4 kJ mol-1.

Metal-free [2+2]-photocycloaddition of unactivated alkenes enabled by continuous flow processing.

We report a continuous flow approach generating bicyclic cyclobutanes from unactivated alkenes in a metal-free manner that is inspired by the Kochi-Salomon reaction. A filtered Hg-lamp in combination with a simple flow set-up and acetone as UV light-absorbing co-solvent are crucial for this method thus showcasing attractive features for further exploitations.