Improve Process Performance Research Articles

Performance Comparison of Polymeric and Silica-Based Multi-Bed Pervaporation Membrane Reactors during Ethyl Levulinate Production.

A detailed numerical study of ethyl levulinate (EtLA) production with levulinic acid (LA) and ethanol (Et) in a multi-bed traditional reactor (MB-TR) and a silica-based and polymeric multi-bed pervaporation membrane reactors (MB-PVMR) was conducted and the efficiency of each design was studied under different operation conditions. Due to water production in the EtLA production process, water removal by a pervaporation system may improve process performance. Our results showed that MB-PVMR had higher performance compared with MB-TR. In addition, the silica membrane was more effective in water removal compared with the polymeric membrane. Therefore, higher LA conversion was achievable by a silica-based multi-bed pervaporation membrane reactor (SMB-PVMR). All the results were evaluated for percentage of water removal and LA conversion, based on variations in the Et/LA molar ratio, feed molar flow, reaction zone temperature, and catalyst loading. The results showed that water removal was higher than 95% and LA conversion of about 95% was attained by SMB-PVMR.

Novel Computer Tomography image enhancement deep neural networks for asphalt mixtures

• A method for enhancing CT images of asphalt mixtures. • Multiple image enhancement tasks are solved in one model. • The addition of semantic information can improve processing performance. • This study shows that semantic spaces have similarities. This paper aims to solve two significant problems observed in Computer Tomography(CT) asphalt mixture images, which are 1) low-quality CT image, and 2) low efficiency, by intelligent word embedding methods. The first model is called Asphalt Mixture CT Image Enhancement Network (AMCTEN), which is featured by ignoring the semantic loss, while the second model, AMCTEN+, is feature by considering semantic loss without requiring semantic information. Two models can be integrated to realize end-to-end real-application image enhancement. Experimental results show that peak signal to noise ratio of AMCTEN and AMCTEN + in the test set increased by 79.0 % and 66.4 %, structural similarity increased by 15.1 % and 13.3 %, and mean square error decreased by 97.5 % and 95.3 %, respectively. Analysis of semantic feature spaces generated by the two models indicate that word embedding can construct an effective semantic feature space, fusing the semantic features with image features can improve the image quality, and the proposed model has superiority in multiple image enhancement tasks.

A Decision Support System (DSS) for the Prediction and Selection of Optimum Operational Parameters in Pressure Die-Casting Processes.

A large number of material and process parameters affect both the part quality and the process performance in pressure die-casting (PDC) processes. The complex relations between most of these variables make PDC process optimisation a difficult issue which has been widely studied for many years. Although there are several analytical and numerical models to optimise certain process parameters, it is difficult to establish a specific operational configuration for PDC machines that ensures the joint optimisation of these variables. Therefore, in this study, some of these optimisation models have been implemented in a Decision Support System (DSS) that allows us to define an operational region that establishes a setup of machine parameters that ensures the manufacture of quality parts. By using this DSS, the user can set the values of the input variables related to the casting material, the die, or the casting machine. Then the corresponding calculations are made by the system and the results are expressed in terms of certain output variables such as the maximum filling time, maximum filling fraction, or the plunger velocity profile among others. The DSS allows the user to estimate the influence between input and output variables and find proper values for the input variables to achieve an optimum operational range. Consequently, improved process performance can be achieved taking into account productivity, part quality, and economic aspects.

A review of multistage membrane filtration approaches for enhanced efficiency during concentration and fractionation of milk and whey

This review considers the impact of combining discrete membrane filtration configurations in a multistage or sequential configuration to improve processing performance, energy efficiency and component selectivity in dairy processes. The review focuses on the impact of multistage membrane filtration on (i) concentration processes, through the examination of fouling accumulation and its impact on flux and energy efficiency, and (ii) fractionation processes, whereby the yield/purity of dairy components is assessed. Observations from single‐stage and batch microfiltration, ultrafiltration, nanofiltration and reverse osmosis processes reported in the literature are compared to the continuous multistage filtration processes common in commercial dairy installations.

PASS-THROUGH PEAKLESS SABER CUTTER

"The disadvantage of the processing method on existing machines by traditional processing is the lack of a design of a pass-through lathe with a weak point – the top, which is a source of instability of the shape properties and surface quality of the shaft being processed. Finishing with a pass-through peakless reciprocating cutter on a machine with an inclined axis, provided by the use of a device for transmitting rotation to an intersecting axis, thereby achieving efficient high-performance processing of shaft-type workpieces with a reciprocating cutter. The result is achieved by adopting a special processing scheme with an axis tilt. During the grinding process on the proposed lathe, the contact point of the cutter and the workpiece is constantly moving along the cutting edge of the cutter, which reduces the roughness of the surface to be processed, reduces the heating of the cutter, increases the heat sink from the cutting zone. The proposed turning method and cutter will improve processing performance and tool durability. The use of finishing turning of workpieces of the «Shaft» type with an inclined axis is economically profitable in mass and large-scale production."

Two-dimensional multiphase batch process monitoring based on sparse canonical variate analysis

Most industrial batch processes involve inherent dynamic characteristics in both within-batch time direction and batch-wise direction. In order to ensure process safety and improve process performance, the two-dimensional dynamics should be analyzed during batch process monitoring. In this work, two-dimensional region of support (2D-ROS) is first constructed to select and preserve the relevant samples for the current measured sample by calculating autoregressive orders with Akaike information criterion (AIC) in time direction and measuring the similarity with the weighted Euclidean distance in batch-wise direction. Afterwards, sparse canonical variate analysis (SCVA) algorithm is performed to yield sparse canonical vectors, which is especially advantageous for eliminating the irrelevant variables and facilitating the interpretation of underlying relationships of process variables. Meanwhile, given most measurements are subject to the non-Gaussian distribution, the upper control limits (UCLs) in 2D-SCVA can be estimated using kernel density estimation (KDE). The achieved results obtained from a numerical dynamic example and the benchmark fed-batch penicillin fermentation process clearly verify that the proposed method performs well for detecting abnormal operation for the batch processes.

Comparison of Infectious Complications after Surgical Fixation versus Epidural Analgesia for Acute Rib Fractures.

Background: Surgical stabilization of rib fractures (SSRF) is associated with decreased mortality and respiratory complications. Patients who are not offered SSRF are often treated with epidural analgesia (EA) to reduce pain and improve pulmonary mechanics. We sought to compare infectious complications in patients undergoing either SSRF or EA. We hypothesized that infectious complications are equivalent between the two treatment groups. Patients and Methods: We performed a retrospective cohort study of adult trauma patients with acute rib fractures within the Trauma Quality Improvement Program (TQIP) 2017 dataset and used International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) codes to identify patients who underwent SSRF or EA. We excluded patients who received both treatments in the same admission. Our primary outcome was the development of sepsis. Secondary outcomes were specific infections including ventilator-associated pneumonia (VAP), catheter-associated urinary tract infection (CAUTI), and central line-associated blood stream infections (CLABSI). Multiple logistic regression analyses were used to adjust for age, injury severity score (ISS), chest Abbreviated Injury Scale (AIS), flail chest, traumatic brain injury (TBI), and comorbidities. Results: We identified 2,252 and 1,299 patients who underwent SSRF and EA, respectively. Patients with SSRF were younger with higher ISS and longer length of stay (LOS). There was no difference in mortality, however, SSRF had higher rate of sepsis (1.6% vs. 0.5%; p = 0.001), VAP (5.1% vs. 0.9%; p < 0.001), CAUTI (1.7% vs. 0.5%; p = 0.001), and CLABSI (0.2% vs. 0%; p = 0.05). On multiple regression, SSRF was associated with higher odds of sepsis (odds ratio [OR], 2.63; 95% confidence interval [CI], 1.04-6.63), CAUTI (OR, 2.96; 95% CI, 1.11-7.88), and VAP (OR, 3.24; 95% CI, 1.73-6.06). Among those who developed sepsis, there was no significant difference in mortality or LOS between groups. Conclusions: Despite no difference in mortality, SSRF was associated with increased risk of septic complications in patients with rib fractures compared to epidural analgesia. Identifying, and addressing, risk factors of sepsis in this patient population is a critical performance improvement process to optimize outcomes without increased adverse events.

Culture media selection and feeding strategy for high titer production of a lentiviral vector by stable producer clones cultivated at high cell density

The growing interest in the use of lentiviral vectors (LVs) for various applications has created a strong demand for large quantities of vectors. To meet the increased demand, we developed a high cell density culture process for production of LV using stable producer clones generated from HEK293 cells, and improved volumetric LV productivity by up to fivefold, reaching a high titer of 8.2 × 107 TU/mL. However, culture media selection and feeding strategy development were not straightforward. The stable producer clone either did not grow or grow to lower cell density in majority of six commercial HEK293 media selected from four manufacturers, although its parental cell line, HEK293 cell, grows robustly in these media. In addition, the LV productivity was only improved up to 53% by increasing cell density from 1 × 106 and 3.8 × 106 cells/mL at induction in batch cultures using two identified top performance media, even these two media supported the clone growth to 5.7 × 106 and 8.1 × 106 cells/mL, respectively. A combination of media and feed from different companies was required to provide diverse nutrients and generate synergetic effect, which supported the clone growing to a higher cell density of 11 × 106 cells/mL and also increasing LV productivity by up to fivefold. This study illustrates that culture media selection and feeding strategy development for a new clone or cell line can be a complex process, due to variable nutritional requirements of a new clone. A combination of diversified culture media and feed provides a broader nutrients and could be used as one fast approach to dramatically improve process performance.

Efficient Heat Exchange Configuration for Sub-Cooling Cycle of Hydrogen Liquefaction Process

The hydrogen liquefaction process is highly energy-intensive owing to its cryogenic characteristics, and a large proportion of the total energy is consumed in the subcooling cycle. This study aimed to develop an efficient configuration for the subcooling cycle in the hydrogen liquefaction process. The He-Ne Brayton cycle is one of the most energy-efficient cycles of the various proposed hydrogen liquefaction processes, and it was selected as the base case configuration. To improve its efficiency and economic potential, two different process configurations were proposed: (configuration 1) a dual-pressure cycle that simplified the process configuration, and (configuration 2) a split triple-pressure cycle that decreased the flow rate of the medium- and high-pressure compressors. The ortho–para conversion heat of hydrogen is considered by using heat capacity data of equilibrium hydrogen. Genetic algorithm-based optimization was also conducted to minimize the energy consumption of each configuration, and the optimization results showed that the performance of configuration 1 was worse than that of the base case configuration. In this respect, although less equipment was used, the compression load on each compressor was very intensive, which increased the energy requirements and costs. Configuration 2 provided the best results with a specific energy consumption of 5.69 kWh/kg (3.2% lower than the base case configuration). The total expense of configuration 2 shows the lowest value which is USD 720 million. The process performance improvements were analyzed based on the association between the refrigerant composition and the heat exchange efficiency. The analysis demonstrated that energy efficiency and costs were both improved by dividing the pressure levels and splitting the refrigerant flow rate in configuration 2.

A method for assessing the performance of sorting unit operations in a material recovery facility based on waste characterizations

AbstractThe determination of the separation efficiencies of mechanical sorting equipment is essential to improve the performance of material recovery facilities (MRFs). However, it is often a challenge to obtain these efficiencies due to the high complexity of MRFs, which often comprise several recirculation streams. In this paper, a methodology to determine the equipment separation efficiencies of a complex MRF is described and applied to an actual sorting centre located in the province of Quebec, Canada. Transfer coefficients for every unit operation and several material types, together with all material flows within the facility, have been determined for an MRF processing a stream of commingled recyclable materials. This work also provides a rare dataset of separation efficiencies for several mechanical sorting unit operations. The methodology is validated by comparing experimental data and model predictions for the recovery and purity of all main output streams. The results contribute to identify several avenues for process performance improvement, like adding a magnetic separation at the beginning of the sorting sequence or improving the separation of the 2D‐type materials collected from the second ballistic separator by changing the operation conditions or adding a quality control step. Moreover, the results also provide valuable information about material recovery and purity to help managers improve the process performance. Finally, a scenario analysis demonstrates that the performance of a second ballistic separator has an important impact on the sorting process's global efficiency and that recirculating a fraction of the rejects output stream has a negligible impact on the global performance.

The Study of Optimal Performance Improvement Method for Aircraft of Various Variants within the Same Type

In this paper, we studied the optimal method of improving performance for aircraft having various variants within the same type. The study defined configuration of an entire fleet of aircraft being subject to a performance improvement program. And selected the most complicated aircraft configuration among them as a Standard Aircraft for modification by according to the proposed Aircraft Selection Process for developing an optimal Aircraft Performance Improvement Process. Based on the selected the Standard Aircraft, drew a system integration design result and carried out Evaluation Test and obtained Airworthiness Certification. Created the database with the design data of the Standard Aircraft, Evaluation Test, and Airworthiness Certification results, and applied it to variants of aircraft to complete the performance improvement program with optimized schedules and costs. By applying the proposed method to IFF performance improvement program, drew optimal system integration design and completed the program with minimized schedule.

Optimization of multi flow rate loading strategy for process intensification of Protein A chromatography

Monoclonal antibody (mAb) is a widely used therapeutic modality that is being used for treatment of chronic diseases like cancer, psoriasis, and other auto immune diseases. The affordability of these therapeutics is presently low because of their high manufacturing cost. Protein A chromatography step is a major contributor to the cost of manufacturing of mAbs. The proposed study is an attempt to improve process performance of the protein A chromatography step using multi-flow loading strategy. Although continuous chromatography is an efficient tool to improve resin utilization and process productivity, implementation of continuous chromatography warrants additional capital investment. Use of dual flow rate or multi flow rate offers the potential of attaining similar benefit without this additional investment. For optimization of multi flow rate loading strategy, it is necessary to understand the range of operating flow rate, switch time for changing flow rate to next flow rate and the delta change in the flow rate. In the current study, an alternate, industrially feasible and scalable multi flow rate strategy has been developed, which optimizes the switch time for a given set of flow rates. The algorithm uses LDF (linear driving force) model to predict the breakthrough curve. Further, the method optimizes flow trajectory based on simulated breakthrough curves using estimated diffusion coefficients at specific residence times and suggests a switch time strategy leading to a multi-step loading of increasing residence times. It was observed that by operating the process at multiple flow rates, a near maxima of both adsorbent capacity and the productivity can be achieved. Although variable flow rate approaches have been proposed in literature in recent times, our method for multi-step loading is simpler, practical and has been demonstrated both at lab and pilot scales. The results showed that this simple multi-flow loading approach increased loading capacities by ∼20% and resin utilization by ∼15% as compared to regular batch process; with new generation protein A resin, mAb Select PrismATM, as capture chromatography. Approximately 60% reduction in $COGS/g has been demonstrated when compared to constant flow batch process, similar to the benefits obtained with multi-column continuous chromatography.

Active cooling performance of a PCM-based thermoelectric device: Dynamic characteristics and parametric investigations

Phase change materials (PCM) are widely seen as a cooling medium in thermoelectric systems capable of effectively reducing the hot end temperature of thermoelectric device and improving energy conversion efficiency. In this study, a comprehensive numerical model is developed to investigate the active cooling performance of a PCM-based thermoelectric device where the phase-change dynamics and thermoelectric conversion physics take place simultaneously. The dynamic changes of key parameters, such as hot and cold end temperatures of thermoelectric device, liquid fraction of PCM over time under typical operating conditions are simulated to better understand the dynamic characteristics of the PCM-based thermoelectric device. The thermoelectric operating current, cooling load, component height ratio and PCM melting temperature have been parametrically swept to evaluate their effects on the system's cooling performance. And then a comparison analysis on active cooling potential of thermoelectric device with and without PCM is performed in terms of the energy and exergy efficiencies. Furthermore, temperature distribution and cooling region of PCM-based thermoelectric device are sensitively determined to better reveal their dynamic matching mechanism. Numerical results demonstrated that the cooling time of the PCM-based thermoelectric device has been obviously extended due to the constant maintenance in the cold end temperature of thermoelectric device during phase change period. The energy and exergy efficiencies of the PCM-based thermoelectric device are found to be 30.08%, 402.08% greater, respectively, than that of the thermoelectric device without PCM when the time is 20 s. Present research could be beneficial for cooling performance improvement of the thermoelectric-phase change coupling processes.

Kinetic evaluation of petroleum refinery wastewater biodegradation in an activated sludge process

Experimental assessment of process kinetic is essential for process modelling and can serve as a useful tool to improve process performance. In this study, kinetic evaluation of petroleum refinery wastewater (PRWW) biodegradation in an activated sludge process (ASP) was carried out in a 25 L ASP reactor which was operated within the conventional aeration mode of 2-10 hours, hydraulic retention time (HRT), effluents from the secondary sedimentation tank were analyzed at various HRT for biochemical oxygen demand (BOD) and biomass growth. The data obtained were analyzed and fitted to different related kinetic models which show that the biodegradation of PRWW in ASP follows the Modified Monod Kinetic Model, amongst the related models evaluated, with 0.9745 correlations with the experimental data. Physicochemical characterization of the PRWW used for the study was carried out using the Standard Methods for the Examination of Water and Wastewater; which gave a biodegradability index of 0.3333.

Efficiency of using ozone for extraction of metals from mineral raw materials

The paper summarizes the results of studies on the use of ozone for the extraction of non-ferrous, rare and noble metals from ores, beneficiation concentrates and technogenic raw materials identified from world scientific publications and in patent literature since the early 20th century. Ozone is a strong oxidizing agent with an oxidizing potential 1.5 times higher than the potential of chlorine in an acidic environment. Even refractory metals and minerals dissolve with ozone. Metal extraction from mineral raw materials using ozone does not contaminate processed products or generate any hazardous waste. The paper presents a significant number of studies on the use of ozone to dissolve gold and other noble metals in mineral acids showing an increase in the extraction of metals into the solution. The cyanide and thiourea leaching of gold from mineral raw materials with the replacement of oxygen with ozone was investigated. The paper provides the results of the vat and heap leaching of non-ferrous and noble metals using ozone obtained by air or oxygen irradiation with ultraviolet light, in particular with the use of photoelectrochemical treatment. These results were used as a basis for patenting new technologies. The effectiveness of ozone used in the flotation concentration of mineral raw materials, purification and detoxification of solutions and solid products of metallurgical processing, regeneration of other oxidants, metal extraction from process solutions was evaluated. The results of studies on using ozone for the vat leaching of metals from refractory sulfide ores and sulfide beneficiation concentrates in an acid solution, and the study of the ozone-assisted oxidation kinetics of copper, iron, zinc, and molybdenum sulfide minerals are summarized. The paper provides and analyzes the results of using ozone in a combination with other oxidants – hydrogen peroxide and iron (III) ions – for metal extraction from sulfide mineral raw materials in a sulfuric acid. According to the results of most of the studies carried out, it can be concluded that the use of ozone is effective for metal extraction from mineral raw materials as it improves process performance (metal extraction into the solution, selectivity of metal extraction from complex raw materials), and reduces processing time.

Disparity in Transport of Critically Injured Patients to Trauma Centers: Analysis of the National Emergency Medical Services Information System (NEMSIS).

Patient morbidity and mortality decrease when injured patients meeting CDC Field Triage Criteria (FTC) are transported by emergency medical services (EMS) directly to designated trauma centers (TCs). This study aimed to identify potential disparities in the transport of critically injured patients to TCs by EMS. We identified all patients in the National EMS Information System (NEMSIS) database in the National Association of EMS State Officials East region from January 1, 2018, to December 31, 2019, with a final prehospital acuity of critical or emergent by EMS. The cohort was stratified into patients transported to TCs or non-TCs. Analyses consisted of descriptive epidemiology, comparisons, and multivariable logistic regression analysis to measure the association of demographic features, vital signs, and CDC FTC designation by EMS with transport to a TC. A total of 670,264 patients were identified as sustaining an injury, of which 94,250 (14%) were critically injured. Of those 94,250 critically injured, 56.0% (52,747) were transported to TCs. Among all critically injured women (n = 41,522), 50.4% were transported to TCs compared with 60.4% of critically injured men (n = 52,728, p < 0.001). In a multivariable logistic regression model, critically injured women were 19% less likely to be taken to a TC compared with critically injured men (OR 0.81, 95% CI 0.71-0.93, p = 0.003). Critically injured female patients are less likely to be transported to TCs when compared with their male counterparts. Performance improvement processes that assess EMS compliance with field triage guidelines should explicitly evaluate for sex-based disparities. Further studies are warranted.

A comprehensive study of tantalum powder preparation for additive manufacturing

In this study, sodium reduced tantalum (Ta) powders were processed by fluidization, jet milling and plasma spheroidization respectively to improve processing performance for additive manufacturing (AM). The morphologies, flowability, chemical compositions, and microstructural evolution of as-processed Ta powders were systematically studied. The flowability of raw Ta powder can be significantly improved by both jet milling (JMed) and plasma spheroidization (PSed). The impurities contents of powders in each process did not significantly change. The homogeneous oxide film and bimodal particle size distribution of PSed powder led to a higher laser absorption and wide printing parameters range as compared to JMed powder. The as-printed Ta components exhibited a good part precision and low hardness due to low oxygen content of both JMed and PSed powders.

ANALYSIS, PRACTICAL APPLICATION AND POSSIBLE INTERCONNECTION OF INDUSTRIAL ENGINEERING METHODS AND KEY PERFORMANCE INDICATORS

In connection with applying the principles of Industry 4.0, the industrial practice also requires the consistent application of industrial engineering methods to improve process performance. The transformation of society into digital affects almost all areas of industry, public administration, healthcare and all walks of life. The implementation of Industry 4.0 is very important in the automotive, engineering and electrical engineering industries. It is the move towards Industry 4.0, the collection of large amounts of data and the decision-making based on the data obtained that provide the ideal basis for using more complex industrial engineering methods and better process evaluation. The paper's main goal is to analyse and identify the use of industrial engineering methods and key performance indicators of companies in industrial practice in Slovakia, where practice shows a lower acquaintance with these methods, especially among medium-sized companies. The paper deals with the issue of industrial engineering methods aimed at improving process performance in the context of key performance indicators. The paper contains some results of a questionnaire survey aimed at gathering information on improvement methods and identifying the use of key performance indicators in industrial practice. Which results will bring us closer to which types of methods are most used in Slovak practice and why?

Enhancing Energy Efficiency of Sram through Optimization of Sram Array Structures

Reliability is a major concern in the microprocessor industry. In terms of power consumption, SRAM plays a key role in improving processing performance. Improving SRAM efficiency requires changes to the array structure. A general method in which the SRAM array has more rows than columns.The above techniques are proposed to improve efficiency by 10% for 8kbit and 40% for 64kbit at the same SRAM byte density and supply voltage. Implement suggested deep submicron technology for better reliability. Many proposed designs focus on low power consumption, often with reduced response times.As the technology scales, the power consumption of on-chain system devices with gate leakage, subthreshold current, and tunneling increases significantly. Small SRAM capabilities are important.This task demonstrates the potential of using larger SRAM array structures to achieve better SRAM energy efficiency, especially when the number of rows is less than the number of low-power columns. Compared to traditional 8T SRAM, the proposed 10T cell uses less power, has a different temperature and better performance.

Application of lean Six Sigma methodology using DMAIC approach for the improvement of bogie assembly process in the railcar industry

The quest for waste reduction, quality improvement and operational efficiency during the assembly process of the railcar bogie necessitates this study. Using a case study approach, this study employs the Lean Six Sigma (LSS) approach for process improvement of the railcar bogie assembly process. Primary data relating to the assembly process such as the labour and material flow, up and down times were collected at every stage of the assembly operation. The improvement process of the assembly process featured the use of some Lean tools such as the Kaizen, Value Stream Mapping, Pareto chart, Single-Minute Exchange of Die (SMED) and 5S. The investigation of the current assembly process with the use of the LSS technique indicates that the process efficiency is low due to waste generation. The results obtained showed significant improvement in the process cycle efficiency (PCE) by 46.8%, via the implementation of the Kaizen continuous process improvement approach, 27.9% reduction in the lead-time, 59.3% increase in the value added time and 71.9% reduction in the non-value added time after the implementation of the LSS approach. The findings of this work demonstrated the feasibility of the LSS approach for waste minimisation and process performance improvement in a bid to achieve operational excellence in a manufacturing organisation.