Variety Of Processes Research Articles

Enhancing Construction Management Digital Twins Through Process Mining of Progress Logs

Large-scale infrastructure projects involve numerous complex processes, and even small construction management (CM) deficiencies can lead to significant resource waste. Digital twins (DTs) offer a potential solution to the management side of the problem. The current DT models focus on real-time physical space mapping, which causes the fragmentation of process data in servers and limits lifecycle algorithm implementation. In this paper, we propose a DT framework that integrates process twins to achieve process discovery through process mining and that serves as a supplement to DTs. The proposed framework was validated in a highway project. Based on BIM, GIS, and UAV physical entity twins, construction logs were collected, and process discovery was performed on them using process mining techniques, achieving process mapping and conformance checking for the process twins. The main conclusions are as follows: (1) the process twins accurately reflect the actual construction process, addressing the lack of process information in CM DTs; (2) process variants can be used to analyze abnormal changes in construction methods and identify potential construction risks in advance; (3) sudden changes in construction nodes during activities can affect resource allocation across multiple subsequent stages; (4) process twins can be used to visualize construction schedule risks, such as lead and lag times. The significance of this paper lies in the construction of process twins to complement the existing DT framework, providing a solution to the lost process relationships in DTs, enabling better process reproduction, and facilitating prediction and optimization. In future work, we will concentrate on conducting more in-depth research on process twins, drawing from a wider range of data sources and advancing intelligent process prediction techniques.

Effective removal of host cell-derived nucleic acids bound to hepatitis B core antigen virus-like particles by heparin chromatography.

Virus-like particles (VLPs) show considerable potential for a wide array of therapeutic applications, spanning from vaccines targeting infectious diseases to applications in cancer immunotherapy and drug delivery. In the context of hepatitis B core antigen (HBcAg) VLPs, a promising candidate for gene delivery approaches, the naturally occurring nucleic acid (NA) binding region is commonly utilized for effective binding of various types of therapeutic nucleic acids (NAther). During formation of the HBcAg VLPs, host cell-derived nucleic acids (NAhc) might be associated to the NA binding region, and are thus encapsulated into the VLPs. Following a VLP harvest, the NAhc need to be removed effectively before loading the VLP with NAther. Various techniques reported in literature for this NAhc removal, including enzymatic treatments, alkaline treatment, and lithium chloride precipitation, lack quantitative evidence of sufficient NAhc removal accompanied by a subsequent high VLP protein recovery. In this study, we present a novel heparin chromatography-based process for effective NAhc removal from HBcAg VLPs. Six HBcAg VLP constructs with varying lengths of the NA binding region and diverse NAhc loadings were subjected to evaluation. Process performance was thoroughly examined through NAhc removal and VLP protein recovery analyses. Hereby, reversed phase chromatography combined with UV/Vis spectroscopy, as well as silica spin column-based chromatography coupled with dye-based fluorescence assay were employed. Additionally, alternative process variants, comprising sulfate chromatography and additional nuclease treatments, were investigated. Comparative analyses were conducted with LiCl precipitation and alkaline treatment procedures to ascertain the efficacy of the newly developed chromatography-based methods. Results revealed the superior performance of the heparin chromatography procedure in achieving high NAhc removal and concurrent VLP protein recovery. Furthermore, nuanced relationships between NA binding region length and NAhc removal efficiency were elucidated. Hereby, the construct Cp157 surpassed the other constructs in the heparin process by demonstrating high NAhc removal and VLP protein recovery. Among the other process variants minimal performance variations were observed for the selected constructs Cp157 and Cp183. However, the heparin chromatography-based process consistently outperformed other methods, underscoring its superiority in NAhc removal and VLP protein recovery.

Banked Primary Progenitor Cells for Allogeneic Intervertebral Disc (IVD) Therapy: Preclinical Qualification and Functional Optimization within a Cell Spheroid Formulation Process.

Background/Objectives: Biological products are emerging as therapeutic management options for intervertebral disc (IVD) degenerative affections and lower back pain. Autologous and allogeneic cell therapy protocols have been clinically implemented for IVD repair. Therein, several manufacturing process design considerations were shown to significantly influence clinical outcomes. The primary objective of this study was to preclinically qualify (chondrogenic potential, safety, resistance to hypoxic and inflammatory stimuli) cryopreserved primary progenitor cells (clinical grade FE002-Disc cells) as a potential cell source in IVD repair/regeneration. The secondary objective of this study was to assess the cell source's delivery potential as cell spheroids (optimization of culture conditions, potential storage solutions). Methods/Results: Safety (soft agar transformation, β-galactosidase, telomerase activity) and functionality-related assays (hypoxic and inflammatory challenge) confirmed that the investigated cellular active substance was highly sustainable in defined cell banking workflows, despite possessing a finite in vitro lifespan. Functionality-related assays confirmed that the retained manufacturing process yielded strong collagen II and glycosaminoglycan (GAG) synthesis in the spheroids in 3-week chondrogenic induction. Then, the impacts of various process parameters (induction medium composition, hypoxic incubation, terminal spheroid lyophilization) were studied to gain insights on their criticality. Finally, an optimal set of technical specifications (use of 10 nM dexamethasone for chondrogenic induction, 2% O2 incubation of spheroids) was set forth, based on specific fine tuning of finished product critical functional attributes. Conclusions: Generally, this study qualified the considered FE002-Disc progenitor cell source for further preclinical investigation based on safety, quality, and functionality datasets. The novelty and significance of this study resided in the establishment of defined processes for preparing fresh, off-the-freezer, or off-the-shelf IVD spheroids using a preclinically qualified allogeneic human cell source. Overall, this study underscored the importance of using robust product components and optimal manufacturing process variants for maximization of finished cell-based formulation quality attributes.

Sliding and Adaptive Windows to Improve Change Mining in Process Variability

A configurable process Change Mining approach can detect changes from a collection of event logs and provide details on the unexpected behavior of all process variants of a configurable process. The strength of Change Mining lies in its ability to serve both conformance checking and enhancement purposes; users can simultaneously detect changes and ensure process conformance using a single, integrated framework. In prior research, a configurable process Change Mining algorithm has been introduced. Combined with our proposed preprocessing and change log generation methods, this algorithm forms a complete framework for detecting and recording changes in a collection of event logs. Testing the framework on synthetic data revealed limitations in detecting changes in different types of variable fragments. Consequently, it is recommended that the preprocessing approach be enhanced by applying a filtering algorithm based on sliding and adaptive windows. Our improved approach has been tested on various types of variable fragments to demonstrate its efficacy in enhancing Change Mining performance.

Submerged arc welding process: enhancement of production performance based on metallurgical observations

Welding processes are widely used technologies in the industrial context for creating permanent connections between mechanical components. This popularity is due to their versatility, which arises from the numerous available process variants and the multiple advantages they offer compared to other joining techniques. In the manufacturing context, where devices often operate in extreme conditions, the quality of welds becomes a critical factor in ensuring the safety and reliability of the manufactured products. Furthermore, a sound joint requires careful compliance with the increasingly stringent design specifications demanded by customers who require industry-standard conformity in order to achieve defect-free, robust, and durable welds. To address these needs and to define the optimal roadmap for the investigated process condition, an experimental investigation was conducted on the submerged arc welding process. The experimental trials involved butt joints of ASTM A516 Gr.70 carbon steel plates with different thicknesses in a flat position, utilizing a U-shaped chamfer and a multi-pass welding technique. For each weldment, the effects of the main process parameters on the qualitative characteristics of the manufactured products were evaluated from a metallurgical perspective. This evaluation included an in-depth metallographic analysis of the heat-affected zone of the carbon steel joint and involved both the measurement of the dimensions of these areas as well as the amount of ferrite and pearlite that resulted as the phases observed in the final microstructure of the steel joint following its solidification. Furthermore, the joint quality was assessed with regard to mechanical strength through hardness measurements. By analysing the experimental data, the paper provides a valuable contribution for increasing the productivity of the investigated welding process, while simultaneously meeting the specified industrial quality requirements for the products made of medium-thickness carbon steels.

Techno-economic analysis of cleaner alternatives for recovering ammonium chloride from wastewater generated by polyvinyl chloride thermal stabilizer plants

The current conventional process for recovering NH4Cl from wastewater generated by organotin mercaptide-based polyvinyl chloride thermal stabilizer plants through evaporative crystallization is energy intensive and has not yet been discussed. Three energy-saving process variants, namely mechanical vapor recompression (MVR), double-effect evaporation (DEE), and thermal vapor recompression (TVR) processes, have been proposed and evaluated in terms of both technical and economic feasibility, treating the case as a cost-cutting project aimed to avoid off-site wastewater treatment costs. Comparative evaluation has also been carried out with the conventional (CON) process used as a reference. Under the studied conditions, the MVR, DEE, and TVR processes provided energy savings in the ranges of 60%–76%, 35%–43%, and 26%–37%, respectively, confirming that applying the three alternative processes for recovering NH4Cl results in a significantly cleaner and more sustainable recovery process. Under typical conditions and with a plant capacity of 5000 kg/h, the MVR, DEE, and TVR processes required an additional investment of 2.3, 1.0, and 0.2 million USD, respectively, compared to the CON process. The revenue was primarily driven by cost savings due to the elimination of off-site wastewater treatment, which accounted for 86.9% of the total revenue. Sensitivity analysis showed that the off-site wastewater treatment cost was found to be the most influential factor on economic feasibility. When economic targets can be traded off, MVR process is highly recommended as an alternative to the conventional energy-intensive process. If economic feasibility comparable to the conventional process is still targeted, DEE and TVR are recommended. The results of this study dismiss concerns that cleaner processes would have a negative economic impact.

Ultrasonic vibration-assisted single point incremental forming of hemispherical shaped component using AA3003 material

ABSTRACT Ultrasonic vibration-assisted single point incremental forming is a recent hybrid process variant of the single point incremental forming process. In this process, longitudinal ultrasonic vibration is used as an assistance in the conventional forming process. In this paper, the effect of amplitude of vibration in the ultrasonic vibration assisted single point incremental forming process have been researched. For the same, experimental work has been carried out by forming the hemispherical shaped components using multistage forming strategy. Moreover, numerical simulation work has been carried out using the LSDYNA solver and the results have been discussed in the light of depth of forming and strain distribution. The experimental fracture forming line is also developed for the AA3003 material for single point incremental forming process. High amplitude of vibration of 12 micron with 20 kHz frequency leads to poor formability; however, the lower amplitude of vibration of 8 micron with 30 kHz frequency leads to good formability.

Comparative Analysis of Microabrasive Film Finishing Effects across Various Process Variants.

The paper investigates various methods of microfinishing and arrives at the best technique to produce a very smooth surface. Various setups, with and without oscillation, were developed, together with a microfinishing attachment used on conventional lathes and milling machines. The workpiece material used was an amorphous nickel-phosphorus Ni-P alloy. The surface roughness parameters, such as Sa, Sv, and Sp, were measured with the TalySurf CCI6000 instrument. For the measurement of the surface protrusions, an "analysis of islands" technique was used at various levels of cut-off. The 2BA method-machining below the workpiece axis with oscillation-turned out to be the most effective method applied because it had the highest density of protrusions while having the smallest value of surface roughness. Non-oscillation with the machining zone below the axis also becomes effective, indicating that repositioning can compensate for a lack of oscillation. Already, the very compact surface structure achieved with minimized depths in the valleys by the 2BA method supported the improvement in tribological performance and increase in load-carrying capacity, together with lubricant retention enhancement. These results show that the microfinishing process can be optimized by parameter tuning, and also, non-oscillating methods could come to be a practical alternative, probably reducing the complexity of equipment and cutting costs. Further studies need to be aimed at the scalability of these methods and their application to other materials and fields.

Process integration and techno-economic assessment of crystallization techniques for Na2SO4 and NaCl recovery from saline effluents

Saline effluents containing primarily sodium chloride (NaCl) and sodium sulfate (Na2SO4) are generated from common salt production, tannery CETPs, textiles industries, desalination rejects, etc. In this work, experimental studies have been conducted for parametric evaluation of crystallization techniques for selective isolation of Na2SO4 and NaCl from saline effluent. Three crystallization approaches, i.e., evaporation-crystallization, cooling-crystallization, and antisolvent-crystallization, are assessed through parametric studies. A representative saline solution generated from a salt refinery unit is considered for the study. Lab-scale experiments were performed to determine the optimum process conditions for each crystallization process, and their performance was evaluated by estimating the separation efficiency. Chemical, P-XRD, and TGA analyses were performed to characterize the product composition, purity, and hydration state. For selective Na2SO4 recovery, cooling crystallization, and antisolvent crystallization were found suitable over evaporation crystallization. Subsequently, integrated process variants for cooling crystallization and antisolvent crystallization-based separation were developed. A techno-economic assessment (TEA) was performed to compare integrated process variants for the recovery of salts (Na2SO4 and NaCl) and establish the prospective towards commercialization. The parametric evaluation and TEA shows that the combined crystallization technologies can be potential approach to recover added-value products from saline effluents promoting waste to wealth notion.

Influence of wax addition on feedstock processing behavior in additive manufacturing of metals by material extrusion

The additive manufacturing of metals by material extrusion in a multi-step process (MEX-MSt/M) represents a special process variant of the commonly used material extrusion (MEX) and is based on the processing of highly filled polymer filaments. This technology uses the geometrical freedom and fast processing given by MEX to create individual metal parts after a debinding and sintering process in a cost and time-efficient way. The filaments for MEX-MSt/M are made by incorporating metal powders, such as aluminum, stainless steel, or bronze into a polymer matrix. Due to the challenges that are assigned to the processing of highly filled polymers, like the increased viscosity of the material or clogging of the nozzle, the binder materials have to meet several requirements. Therefore, waxes are often used to enable a better extrusion behavior for MEX; however, the addition of wax also affects other crucial processing properties of the filaments. In this work, the interactions of different types and amounts of waxes on thermal, mechanical, and rheological properties were investigated to create a better understanding of the alternating effects of wax addition into highly filled filaments for processing via MEX. The study demonstrated that an increase in wax contents resulted in both a significant decrease in ductility and an overall improvement in melt flowability. The choice of waxes also affected the particle–matrix interactions, partly leading to an improved wetting of the filler particles.

The Effect of Refined Coherent Grain Boundaries on High-Temperature Oxidation Behavior of TiAl-Based Alloys through Cyclic Heat Treatment

The grain size of the full lamellae TiAl-based alloy changes from ~400 μm to ~40 μm through the precipitation of metastable structures by cyclic heat treatment. Based on this, two kinds of variant selection processes—coherent metastable γ variants precipitated during the air-cooling process and αs variants precipitated during the holding at a single α phase region process—are identified to promote the formation of refined Type I and Type II coherent grain boundaries. The oxidation tests at 1000 °C for 100 h show that the formation of refined coherent grain boundaries can greatly improve oxidation resistance by inducing the continuous multi-layer protective barrier consisting of (Ti, (Nb, Ta))O2, TiN, and Al(Nb,Ta)2. This protective barrier inhibits the inward diffusion of oxygen and nitrogen.

On Solute Recovery and Productivity in Chiral Resolution through Solid-State Deracemization by Temperature Cycling.

Temperature cycling represents an effective means for the deracemization of chiral compounds that crystallize as conglomerates and racemize in solution. In such a process, a suspension enriched in the desired enantiomer is converted into an enantiopure one through periodic cycles of crystal dissolution and crystal growth. We show that performing temperature cycling at higher temperatures leads to faster deracemization and, consequently, higher productivity. However, this comes at the cost of lower recovery, as the solution contains potentially relevant amounts of solute due to the higher solubility at an elevated temperature. In this work, we introduce and compare two process variants that mitigate this issue. The first involves temperature cycling, followed by linear cooling, whereas the second is based on merging the temperature cycles and cooling crystallization. Experiments carried out with the chiral compound N-(2-methylbenzylidene)-phenylglycine amide show that the former variant is faster than the latter, and it is easier to design and implement. In this process, the choice of an appropriate cooling rate is essential to avoid nucleation of the undesired enantiomer.

Influence of classified pore contents on the dynamic strength of the welded joint in gas metal arc welding with different process variants made of galvanized and uncoated complex-phase (CP) steel

Influence of classified pore contents on the dynamic strength of the welded joint in gas metal arc welding with different process variants made of galvanized and uncoated complex-phase (CP) steel

Thermal decomposition of polyolefins under different oxygen content. Composition of products and thermal effects

The thermal decomposition of polyethylene and polypropylene was studied under conditions of different oxygen contents in the carrier gas in the temperature range of 200–600 °C. The effect of adding an oxidizing agent to the carrier gas was studied at (O2/N2)mol ratios of 0/100; 1/99; 2/98; 4/96; 6/94; 10/90; 21/79. Combined TG-FTIR and TG-DSC techniques were used in the studies. Based on FTIR spectra, a quantitative and qualitative analysis of the process gaseous products was performed. The study showed that the thermal degradation of polyolefins can lead to mixtures of saturated and unsaturated hydrocarbons, which are an attractive substitute for natural gas for hydrogen production. The molar ratio of saturated/unsaturated hydrocarbons for PE and PP is 3/2. The composition of the gas product mixture as well as the heat balance of the process can be controlled by adjusting the oxygen concentration in the carrier gas. With a content of 3%O2 in the carrier gas for PE and 4%O2 for PP, autothermal conditions of the thermal processing of polyolefins are achieved. The addition of oxygen accelerates the transformation of polyolefins and thus lowers the optimal process temperature. The CxHyO and CO mixture, coexisting with the hydrocarbon mixture in some process variants, can be converted by the water shift reaction into a mixture of H2 and CO2.

Advances in Parylene Adhesive Bonding for the Realization of Biocompatible Microsystems

Wafer to wafer and chip to wafer bonding technologies are a key enabling processes for the fabrication of microsystems. The presented paper focuses on the latest research results of Parylene adhesive bonding. Given the established wafer bonding processes based on Parylene C in vacuum, research on how the bonding process alters the Parylene material was performed using x-ray diffraction. Doing so, a significant increase of the crystalline fraction of Parylene was observed. In order to further develop the Parylene bonding beyond its state of the art, new process variants were successfully established with advanced features: Wafer bonding using Parylene C at increased pressure; Wafer bonding using Parylene N and Parylene F, respectively, to address a different bonding temperature range; as well as chip bonding using Parylene C in air.

Residual Stress Engineering for Wire Drawing of Austenitic Stainless Steel X5CrNi18-10 by Variation in Die Geometries-Effect of Drawing Speed and Process Temperature.

As a result of conventional wire-forming processes, the residual stress distribution in wires is frequently unfavorable for subsequent forming processes such as bending operations. High tensile residual stresses typically occur in the near-surface region of the wires and can limit further application and processability of the semi-finished products. This paper presents an approach for tailoring the residual stress distribution by modifying the forming process, especially with regard to the die geometry and the influence of the drawing velocity as well as the wire temperature. The aim is to mitigate the near-surface tensile residual stresses induced by the drawing process. Preliminary studies have shown that modifications in the forming zone of the dies have a significant impact on the plastic strain and deformation direction, and the approach can be applied to effectively reduce the process-induced near-surface residual stress distributions without affecting the diameter of the product geometry. In this first approach, the process variant using three different drawing die geometries was established for the metastable austenitic stainless steel X5CrNi18-10 (1.4301) using slow (20 mm/s) and fast (2000 mm/s) drawing velocities. The residual stress depth distributions were determined by means of incremental hole drilling. Complementary X-ray stress analysis was carried out to analyze the phase-specific residual stresses since strain-induced martensitic transformations occurred close to the surface as a consequence of the shear deformation and the frictional loading. This paper describes the setup of the drawing tools as well as the results of the experimental tests.

Prototype measurement results in a 65 nm technology and TCAD simulations towards more radiation tolerant monolithic pixel sensors

Early measurements on monolithic pixel sensor prototypes in the TPSCo 65 nm technology indicate a different response and radiation tolerance (up to5×1015 1 MeV neq cm) for different sensor layout and process variants, illustrating the importance of layout and process in the path towards increased sensor radiation tolerance. Using these measurement results, TCAD simulations provide more insight to link the macroscopic behaviour of specific sensor variants to the details of its structure. With this insight we can propose a new variant combining the advantages of several measured variants as a path to even better radiation tolerance for the next iteration.

An innovative pulsed current arc welding technology for armor steel: Processes, microstructure, and mechanical properties

This study presents a novel pulsed current arc welding technology, specifically pulsed current gas tungsten arc welding (PC-GTAW), single and double pulse gas metal arc welding (SP/DP-GMAW), and dual process welding (D-process). This study aims to investigate the effectiveness of these welding techniques for armor steel weldments. This research focused on investigating the welding processes, resulting microstructures, and mechanical properties of welded joints. Based on the macrography analysis, it was determined that the weldments exhibit no signs of porosity, inclusions, or inadequate penetration. This finding substantiates the optimum settings for the weldment production process. The weldment optical microstructure, fusion, and heat-affected zone were examined in the weld interface. The microstructural properties of the FZ include δ-ferrite, austenite, bainite, and acicular martensite. The HAZ has a bainite-untempered martensite microstructure. The chemical composition and variations across the weldment (base, weld and HAZ) were identified. The grain borders contained greater quantities of Cr, Ni, Mn, Si, and Mo than those of the grain cores. EBSD revealed average weld zone grain sizes of 17.7 µm, 32.6 µm, 30.8 µm, and 24.6 µm for PC-GTAW, SP-GMAW, DP-GMAW, and D-Process, respectively.Furthermore, the hardness measurements showed a progressive transition across different regions. Additionally, the D-Process-fabricated material exhibited a maximum ultimate tensile strength of 872 MPa and an elongation of 4%. The mechanical properties exhibited by this new process variant exceed those of other weldments, indicating its potential for fabricating armor steel. The impact toughness demonstrated superior performance in all the weldments. Within this context, the new use of pulsed current advanced welding methods has shown the ability to generate welded parts of exceptional quality.

Role of Exergy‐Based Process Evolution for Sustainable Steel Making: Rotary Hearth Furnace with Electric Arc Furnace Smelting

In conjunction with an electric arc furnace (EAF) process, a rotary hearth furnace (RHF) has emerged as a supplementary ironmaking unit to produce extra iron from iron‐bearing solid wastes from an integrated steel plant. Additionally, such units offer fuel‐switching options to low‐carbon input fuels. Exergy analysis is carried out for two variants of RHF, producing iron nuggets (ironmaking technology mark 3 process) or direct reduced iron (DRI; FASTMET process), involving cold/hot charging of DRI and scrap use in EAF. Process sustainability as characterized by higher exergy efficiency and lower CO2 emission has been analyzed for two variants of RHF‐EAF steelmaking systems, blast furnace‐basic oxygen furnace (BOF), scrap‐EAF, and COREX‐BOF process. Model‐based information for these parameters for RHF‐EAF process has been compared with other major steelmaking routes based on literature information. The RHF‐EAF process variants with some modification in process flow display better sustainability with relatively higher exergy efficiencies and low CO2 emissions as compared to other steelmaking processes and reasonably meet sustainable steelmaking process evolution criterion.

Process mining and customer journey mapping in healthcare: Enhancing patient-centred care in stroke rehabilitation.

Patient-centred care and enhancing patient experience is a priority across Australia. Stroke rehabilitation has multiple consumer touchpoints that would benefit from a better understanding of customer journeys, subsequently impacting better patient-centred care, and contributing to process improvements and better patient outcomes. Customer journey mapping through process mining extracts process data from event logs in existing information systems discovering patient journeys, which can be utilized to monitor guideline compliance and uncover nonconformance. Utilizing process mining and variant analysis, customer journey maps were developed for 130 stroke rehabilitation patients from referral to discharge. In total, 168 cases from the Australasian Rehabilitation Outcomes Centre dataset were matched with 6291 cases from inpatient stroke data. Variants were explored for age, gender, outcome measures, length of stay and functional independence measure (FIM) change. The study illustrated the process, process variants and patient journey map in stroke rehabilitation. Process characteristics of stroke rehabilitation patients were extracted and represented utilizing process mining and results highlighted process variation, attributes, touchpoints and timestamps across stroke rehabilitation patient journeys categorized by patient demographics and outcome variables. Patients demonstrated a mean and median duration of 49.5 days and 44 days, respectively, across the patient journeys. Nine variants were discovered, with 78.46% (n = 102) of patients following the expected sequence of activities in their stroke rehabilitation patient journey. Relationships involving age, gender, length of stay and FIM change along the patient journeys were evident, with four cases experiencing stroke rehabilitation journeys of more than 100 days, warranting further investigation. Process mining can be utilized to visualize and analyse patient journeys and identify gaps in service quality, thus contributing to better patient-centred care and improved patient outcomes and experiences in stroke rehabilitation.