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Showing records 27811 to 27835 of 43292. [First] Page: 1 1110 1111 1112 1113 1114 1115 1116 1117 1118 Last
27811. LAPSE:2023.11323
Evaluation of the Processing of Multi-Crop Plants into Pelletized Biofuel and Its Use for Energy Conversion
February 27, 2023 (v1)
Subject: Energy Systems
Keywords: fibrous hemp, field bean, harmful emissions, intercropping, maize, pellets utilization, solid fuel
Multi-crop plants (fibrous hemp, maize, and faba bean) can potentially be an alternative to wood biomass pellets, but there is no detailed knowledge to support the suitability of this biomass for solid biofuel production. The aim of this study is to analyze and justify the suitability of multi-crop plant biomass for the production of biofuel pellets and to assess the environmental impact of burning them. This paper presents studies of physical-mechanical, thermal, and chemical characteristics of biofuel pellets from multi-crop plants and emissions during their combustion under laboratory conditions. The main parameters of the produced pellets were determined according to international standards, which are detailed in the methodology part. The length of the produced pellets ranged from 17.6 to 26.6 mm, and the diameter was about 6 mm. The density of wet pellets varied from 1077.67 to 1249.78 kg m−3. The amount of ash in the pellets varied from 5.75% to 8.02%. Determined lower calorific... [more]
27812. LAPSE:2023.11322
Rehydration Activity of High-Temperature Calcined Recycled Sand Autoclaved Aerated Concrete
February 27, 2023 (v1)
Subject: Materials
Keywords: autoclaved aerated concrete, calcined, electrical conductivity, hydration heat, rehydration activity, strength activity index
Autoclaved aerated concrete is an excellent thermal insulation wall material, but with a large amount of waste. This paper describes the high-temperature activation and rehydration activity of waste cement−lime−sand autoclaved aerated concrete (SAAC) and discusses the high-temperature phase transition of SAAC. SAAC calcined at 750 °C was confirmed to be a metastable and amorphous state, which could hydrolyze Ca2+ ions with reactivity in water. The conductivity curve demonstrates that the concentration of ions in the suspension decreases rapidly at 150−250 min, and the hydration reaction turns dominant at this time. The hydration heat curve also displays a hydration exothermic peak at 2.5 h. In addition, the conductivity measurement of suspension and the exothermic measurement of hydration reaction proves that SAAC calcined at 750 °C has a hydration activity and can rehydrate with SiO2 in the system. The rehydration activity was verified by replacing 30% cement in the standard test bloc... [more]
27813. LAPSE:2023.11321
Correlations of HTSD to TBP and Bulk Properties to Saturate Content of a Wide Variety of Crude Oils
February 27, 2023 (v1)
Subject: Materials
Keywords: characterization, correlation, crude oil, HTSD, intercriteria analysis, Petroleum, regression, SARA, TBP
Forty-eight crude oils with variations in specific gravity (0.782 ≤ SG ≤ 1.002), sulphur content (0.03 ≤ S ≤ 5.6 wt.%), saturate content (23.5 ≤ Sat. ≤ 92.9 wt.%), asphaltene content (0.1 ≤ As ≤ 22.2 wt.%), and vacuum residue content (1.4 ≤ VR ≤ 60.7 wt.%) were characterized with HTSD, TBP, and SARA analyses. A modified SARA analysis of petroleum that allows for the attainment of a mass balance ≥97 wt.% for light crude oils was proposed, a procedure for the simulation of petroleum TBP curves from HTSD data using nonlinear regression and Riazi’s distribution model was developed, and a new correlation to predict petroleum saturate content from specific gravity and pour point with an average absolute deviation of 2.5 wt.%, maximum absolute deviation of 6.6 wt.%, and bias of 0.01 wt.% was developed. Intercriteria analysis was employed to evaluate the presence of statistically meaningful relations between the different petroleum properties and to evaluate the extent of similarity between th... [more]
27814. LAPSE:2023.11320
Study on the Equivalence of Metallic-Cerium-Simulated Uranium-Aerosol Generation under Fire
February 27, 2023 (v1)
Subject: Materials
Keywords: equivalence, metallic cerium, particle size distribution, source term, uranium aerosols
Uranium aerosols are released from uranium-containing materials in high-temperature environments caused by nuclear accidents or other processes. Research on the generation characteristics of uranium aerosols under such conditions is an important part of nuclear-safety analysis. In this experiment, the similarity between metal cerium aerosols and uranium material aerosols was evaluated from the aspects of particle size distribution and source term. Combined with the experiment data, the effect of air flow rate and sampling time is discussed. The calculation result of the air release fraction (ARF) is 6.07 × 10−3−4.8 × 10−2, and the respirable fraction (RF) is 0.810−0.978, respectively, showing that the size distribution of particles and ARF of the cerium aerosol are different from the results of the uranium aerosols in the literature, while the RF is similar to the results obtained by using the uranium−niobium alloy in the literature.
27815. LAPSE:2023.11319
Dough Rheological Properties and Macronutrient Bioavailability of Cereal Products Fortified through Legume Proteins
February 27, 2023 (v1)
Subject: Materials
Keywords: cereal products, interactions between nutrients, legume protein, rheology
Cereal products are regarded as important protein providers, though they could feature poor nutritional quality due to their occasional imbalanced amino acid content. Cereal proteins are low in cysteine or tryptophan, and rich in methionine; however, while their combination with legume proteins makes them nutritionally more comprehensive, such a possibility must be addressed by the cereal processing industry. However, the incorporation of legume protein concentrates and isolates might also influence the functionality and bioavailability of some cereal constituents. Therefore, the objective of the present review is to gain insights into the effects of cereal products incorporated with legume protein isolates/concentrates, knowing that both the cereals and the protein extracts/isolates are complex structural matrices, and besides the final products acceptability they should efficiently promote the health condition of consumers. The combination of legume proteins with cereals will bring a... [more]
27816. LAPSE:2023.11318
Lithium in a Sustainable Circular Economy: A Comprehensive Review
February 27, 2023 (v1)
Subject: Environment
Keywords: chemical precipitation, circular economy, lithium, lithium recovery
Lithium is a vital raw material used for a wide range of applications, such as the fabrication of glass, ceramics, pharmaceuticals, and batteries for electric cars. The accelerating electrification transition and the global commitment to decarbonization have caused an increasing demand for lithium. The current supply derived from brines and hard rock ores is not enough to meet the global demand unless alternate resources and efficient techniques to recover this valuable metal are implemented. In the past few decades, several approaches have been studied to extract lithium from aqueous resources. Among those studied, chemical precipitation is considered the most efficient technology for the extraction of metals from wastewater. This paper outlines the current technology, its challenges, and its environmental impacts. Moreover, it reviews alternative approaches to recover lithium via chemical precipitation, and systematically studies the effects of different operating conditions on the l... [more]
27817. LAPSE:2023.11317
Assessment of Heavy Metal Pollution in Water Sediment and Study on Pollution Mechanism—Taking the Weihe River Basin in China as an Example
February 27, 2023 (v1)
Subject: Numerical Methods and Statistics
Keywords: APCS-MLR, heavy metals in sediments, risk assessment, source analysis, spatial distribution, Weihe River
To ensure the ecological security of the basin, data on the heavy metal content in the sediments of the Weihe River Basin were collected to analyze the spatial distribution characteristics of heavy metals based on descriptive statistics and geostatistics. The geoaccumulation index and potential ecological risk assessment were conducted, and the number of pollution sources and the contribution rate were determined by combining correlation analysis, principal component analysis, and APCS-MLR. The results showed that the mean values of As, Pb, Zn, Ni, Cr, Hg, Cu, and Cd were 15.42, 27.27, 88.05, 31.05, 75, 0.13, 29.47, and 1.05 mg·kg−1, respectively. Igeo is in the order of Cd > Hg > As > Cu > Pb > Zn > Cr > Ni. Cd had the highest potential ecological risk factor, followed by Hg with a critical risk proportion of 12.6%. The traceability analysis showed that the heavy metals come from mixed, industrial, and agricultural sources, among which Pb, Zn, Ni, Cr, and Cu are affected by soil-formi... [more]
27818. LAPSE:2023.11316
Design and Parametric Optimization of the Injection Molding Process Using Statistical Analysis and Numerical Simulation
February 27, 2023 (v1)
Subject: Numerical Methods and Statistics
Keywords: Minitab, PET preform, process parameter optimization, SolidWorks Plastics, Taguchi method, warpage
Quality control is considered a critical aspect of plastic materials in the injection molding process. Two types of deformations occur during the injection molding process, namely, volumetric shrinkage and warpage. This study aims to optimize the warpage of the polyethylene terephthalate preform (PET) used for the packing of carbonated drinks. PET warpage results in an uneven distribution of material over the wall surface of the preform and causes variation in wall thickness. During the filling operation of carbonated drinks, the preforms are subjected to high pressure at the points where the wall thickness is at a minimum, which induces a high-stress concentration. Under high pressure, the preforms are ruptured at the points where the warpage is at a maximum (stress concentration area), causing wastage of the beverage as well as the preform. In this study, the Taguchi method and analysis of variance (ANOVA) are used to determine the most significant parameters to induce warpage during... [more]
27819. LAPSE:2023.11315
Toward the Transition of Agricultural Anaerobic Digesters into Multiproduct Biorefineries
February 27, 2023 (v1)
Subject: Biosystems
Keywords: agricultural waste, anaerobic digestion, biobased products, biogas, nutrients, polyhydroxyalkanoates, proteins, volatile fatty acids
Anaerobic digestion allows for the proper management of agro-waste, including manure. Currently, more than 18,000 anaerobic digestion plants are under operation in EU, 80% of which are employed in the rural context. Tariff schemes for power generation from biogas produced during anaerobic digestion of agricultural feedstocks in Germany, Italy and Austria are coming to an end and new approaches are needed to exploit the existing infrastructures. Digesters in the rural context can be implemented and modified to be transformed into sustainable multi-feedstock and multi-purpose biorefineries for the production of energy, nutrients, proteins, bio-chemicals such as carboxylic acids, polyesters and proteins. This paper describes how the transition of agricultural anaerobic digesters into multi-products biorefineries can be achieved and what are the potential benefits originating from the application of a pilot scale platform able to treat cow manure and other crop residues while producing vol... [more]
27820. LAPSE:2023.11314
Mechanical Properties and Water Resistance of Magnesium Oxychloride Cement−Solidified Residual Sludge
February 27, 2023 (v1)
Subject: Materials
Keywords: magnesium oxychloride cement, residual sludge, solidification, unconfined compression strength
As a solid waste, the amount of residual sludge produced by the municipal wastewater treatment process is escalating. How to dispose it properly is attracting much attention in society. Herein, solidifying residual sludge using magnesium oxychloride cement (MOC) is promising for converting it into building materials. Various factors of mass ratio (RW/S) of liquid to solid, molar ratio (Rn) of MgO to MgCl2 in MOC, mass ratio (Rm) of residual sludge to MOC, the mass concentration of Na2SiO3 (DNa2SiO3), and dosage of fly ash (DF) influenced the unconfined compression strength (RC) of the as−obtained MOC−solidified residual sludge, and it was characterized using SEM and XRD analysis. The results show that the value of RC for MOC−residual sludge solidified blocks increased initially and then decreased as Rn and Rm increased, respectively, for 60−day curing. At 10−day curing, equilibrium RC was reached at all RW/S values except 1.38, and at 60−day curing, RC decreased with RW/S increasing. T... [more]
27821. LAPSE:2023.11313
Comparison of Scenarios for the Mexican Electricity System for 2050 Energy Transition Law Objectives—Pre COVID-19 Analysis
February 27, 2023 (v1)
Subject: Energy Systems
Keywords: climate change, electricity sector, energy model, low emission analysis platform (LEAP), renewable energies
In recent years, the reports presented on climate change and its consequences highlight the need to create public policy agendas that address the problem of adaptation and mitigation of anthropogenic greenhouse gas (GHG) emissions. Globally, the energy sector is responsible for a significant percentage of GHG emissions, while it is one of the most important sector for economic growth. In particular, the electricity sector in Mexico relies heavily on fossil fuels for electricity generation. This problem has made it essential to design plans and policies that contribute to GHG mitigation. The General Law on Climate Change, whose objective is to determine the guidelines towards a low-carbon economy, has established a goal of reducing emissions by 50% by 2050 concerning the baseline from the year 2000 and proposes to produce 50% of electricity with clean energy by 2050 following the Mexican Energy Transition Law. For this reason, the challenge is to design and develop an environmentally su... [more]
27822. LAPSE:2023.11312
Experimental Investigation of the Characteristics and Transformation Mechanism of Jimsar Oil Shale and Derived Shale Oil
February 27, 2023 (v1)
Subject: Energy Systems
Keywords: heating rate, Jimsar oil shale, pyrolysis mechanism, shale oil, spent shale
An experimental investigation of the characteristics and transformation mechanism of Jimsar oil shale and derived shale oil was conducted using a solid-state nuclear magnetic resonance spectrometer (13C NMR), Fourier transform infrared spectroscopy (FT-IR), liquid 1H NMR, and gas chromatography-mass spectrometry (GC-MS) techniques. The carbon skeleton structure of Jimsar oil shale is mainly composed of aliphatic carbons (70.5%), mostly containing straight-chain methylene (CH2), and aromatic carbon (29.31%). Derived shale oil is primarily made of aliphatic compounds that are dominated by n-alkanes and alkenes (comprising more than 70%). The nature of the conversion of oil shale to shale oil is the decomposition of aliphatic groups dominated by methylene structures in organic matter. Additionally, as the heating rate is increased, the secondary cracking reactions in shale oil could increase the contents of short-chain alkanes and alkenes, which could then enhance the secondary polymeriza... [more]
27823. LAPSE:2023.11311
Alkali Etching Hydrochar-Based Adsorbent Preparation Using Chinese Medicine Industry Waste and Its Application in Efficient Removal of Multiple Pollutants
February 27, 2023 (v1)
Subject: Environment
Keywords: alkali etching, chinese medicine industry waste, hydrothermal carbonization, multi-pollutant adsorbent, treating waste with waste
The annual discharge (6−7 million tons per year) of Chinese medicine industry waste (CMIW) is large and harmful. CMIW with a high moisture content can be effectively treated by hydrothermal carbonization (HTC) technology. Compared with CMIW, the volume and number of pores of the prepared hydrochar increased significantly after alkali etching (AE), and they had abundant oxygen-containing functional groups. These properties provide physical and chemical adsorption sites, improving the adsorbent activity of the alkaline etching of Chinese medicine industry waste hydrochar (AE-CMIW hydrochar). However, few studies have investigated the adsorption of organic dyes and heavy metals in mixed solutions. This study proposed a method of coupling HTC with AE to treat CMIW and explored the potential of AE-CMIW hydrochar to remove metal ions and organic dyes from mixed solution. We analyzed the removal rates of metal ions and organic dyes by the adsorbents and investigated their differences. The res... [more]
27824. LAPSE:2023.11310
Study on Demulsification Technology of Heavy Oil Blended in Xinjiang Oilfield
February 27, 2023 (v1)
Subject: Optimization
Keywords: demulsification, heave oil blended, process optimization, temperature
HYW (Hong Yi Wu line) heavy oil emulsion in Xinjiang Oilfield (Karamay, China) is a kind of heavy oil with high viscosity and high emulsification. Its viscosity reaches 120,000 mPa·s at 40 °C. The emulsion has no demulsification. Even if the demulsification temperature reaches 90 degrees, the concentration of demulsifier reaches 260 mg/L. In this paper, a new process of thermochemical demulsification of heavy oil after blending is studied. First, SE low-viscosity oil with viscosity of 640 mPa·s and water cut of 90% was selected as blended oil. Study the viscosity of SE line and HYW line at different temperatures after fully blended. The results show that the heavy oil blended model conforms to Bingham model. When the temperature is 40 °C and the content of SE line is 30%, the viscosity is less than 10,000 mPa·s. With the increase of temperature, the viscosity continues to decline. When the temperature exceeds 80 °C, the viscosity is less than 1000 mPa·s. The final design SE line conten... [more]
27825. LAPSE:2023.11309
Thermal Treatment and High-Intensity Ultrasound Processing to Evaluate the Chemical Profile and Antioxidant Activity of Amazon Fig Juices
February 27, 2023 (v1)
Subject: Food & Agricultural Processes
Keywords: antioxidant activity, Ficus subapiculata (Miq.) Miq., high-intensity ultrasound, thermal treatment, unconventional food plant
The present paper evaluated the influence of heat treatment (HT) and high-intensity ultrasound (HIUS) on the chemical profile of the Amazon fig (Ficus subapiculata, Moraceae) juices. Antioxidant activity, quantification of carotenoids, total phenolic compounds (TPC), pH, titratable acidity, soluble solids, color and chemical profile (NMR) were evaluated. Treatments did not change the pH (3.4−3.5), titratable acidity (0.044−0.048%) and soluble solids (2.3−2.4 °Brix). The highest antioxidant activity (DPPH, ABTS) and TPC were presented by the HT-treated juice, which was equivalent to 1235 ± 11 µM TE, 1440 ± 13 µM TE and 312 ± 5 mg GAE mL−1, respectively. The treatments influenced the color luminosity according to the L* and a* parameters, while the b* parameter showed no significant change. The L* parameter was elevated in all treated samples compared to the control sample. Analyzing the parameter a* f, it was verified that the sample with thermal treatment (HT) was different from the co... [more]
27826. LAPSE:2023.11308
Tail Prediction for Heterogeneous Data Center Clusters
February 27, 2023 (v1)
Subject: Environment
Keywords: heterogeneous fork-join queuing networks, inhomogeneous nodes, tail prediction
Service providers need to meet their service level objectives (SLOs) to ensure better client experiences. Predicting tail sojourn times of applications is an essential step to combat long tail latency. Therefore, as an attempt to further unravel the power of our prediction model, new study scenarios for heterogeneous environments will be introduced in this research by using either of two methods: white- or black-box solutions. This research presents several techniques for modeling clusters of inhomogeneous nodes. Those techniques are recognized as heterogeneous fork-join queuing networks (HFJQNs). Moreover, included in the research is a nested-event-based simulation model, borrowing help from multi-core technologies. This model adopts the multiprocessing technique to take part in its design to enable different architectural designs for all computing nodes. This novel implementation of the simulation model is believed to be the next logical step for research studies targeting heterogene... [more]
27827. LAPSE:2023.11307
The Effect of Organic Fillers on the Mechanical Strength of the Joint in the Adhesive Bonding
February 27, 2023 (v1)
Subject: Materials
Keywords: adhesive bonding, mechanical strength, organic filler, the single lap joint, waste material
The most important advantages of adding additives to adhesives are increasing the bonding strength and reducing the adhesive cost. The desire to reduce costs as well as the need for environmentally friendly and health-friendly products have paved the way for the recycling of waste materials and the use of cheaper natural materials as additives. In this study, mussel, olive pomace, and walnut powders in different ratios (5%, 15%, and 30% by weight) and in different sizes (38 and 45 µm) were added to an epoxy adhesive. The steel materials were joined in the form of single-lap joints by using the obtained adhesives with additives. These joints were subjected to the tensile test and the strengths of these joints were examined. SEM images of the bonding interface were taken, and the distribution of the powders was examined. When the powder size was 45 µm, bond strengths increased in all additive ratios compared to the pure adhesive, while for 38 µm powders, the strength value increased only... [more]
27828. LAPSE:2023.11306
Investigations on Microstructure and Mechanical Properties of AZ91 Alloy Processed by Single Pass Rolling with Varied Rolling Reductions
February 27, 2023 (v1)
Subject: Materials
Keywords: mechanical properties, metals and alloys, microstructure, rolling reduction, single pass rolling (SPR)
In this study, single pass rolling (SPR) with varied rolling reductions was conducted on pre-homogenized AZ91 alloys (H alloys) and ECAP-processed AZ91 alloys (HE alloys). The effects of rolling reduction on the microstructures and mechanical properties of HR alloys (pre-homogenized and rolled) and HER alloys (ECAP-processed and rolled) were investigated. The results showed that the HER alloys possessed much finer microstructures and superior mechanical properties than the HR alloys, which were significantly influenced by the rolling reduction. The microstructures of the HER alloys became bimodal, and the strength and elongation markedly improved with the increase in the rolling reduction. When the rolling reduction reached 70%, the HER alloys acquired a typical bimodal structure, contributing to their excellent comprehensive mechanical properties.
27829. LAPSE:2023.11305
Diagnosis of Osteoarthritis at an Early Stage via Infrared Spectroscopy Combined Chemometrics in Human Serum: A Pilot Study
February 27, 2023 (v1)
Subject: Materials
Keywords: ATR-FTIR, biomarkers, blood testing, chemometrics, infrared spectroscopy, osteoarthritis, serum diagnostics
Methods applied for early diagnosis of osteoarthritis (OA) are limited. Early prevention and treatment can effectively reduce the pain of OA patients and save costs. The present study aimed to develop a rapid non-destructive detection method for early diagnosis of OA by evaluating infrared (IR) spectroscopy combined chemometrics. Our cohort consisted of (a) 15 patients with osteoarthritis (OA) and (b) 10 without clinical signs of the disease and they were used as controls. Attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy was used to investigate serum samples (50 µL) collected from these patients. A supervised classification algorithm namely discriminant analysis (DA) was applied to evaluate the diagnostic accuracy spectral processing and chemometrics analysis allowed for detecting spectral biomarkers that discriminated the two cohorts. About 250 infrared spectra were statistically important for separating the groups. Peaks at 1000 cm−1 in OA serum were ass... [more]
27830. LAPSE:2023.11304
Methods and Advances in the Design, Testing and Development of In Vitro Diagnostic Instruments
February 27, 2023 (v1)
Subject: Energy Systems
Keywords: design, in vitro diagnostic instruments, market trends, system engineering, testing and development methods
With the continuous improvement of medical testing and instrumentation engineering technologies, the design, testing and development methods of in vitro diagnostic instruments are developing rapidly. In vitro diagnostic instruments are also gradually developing into a class of typical high-end medical equipment. The design of in vitro diagnostic instruments involves a variety of medical diagnostic methods and biochemical, physical and other related technologies, and its development process involves complex system engineering. This paper systematically organizes and summarizes the design, testing and development methods of in vitro diagnostic instruments and their development in recent years, focusing on summarizing the related technologies and core aspects of the R&D process, and analyzes the development trend of the in vitro diagnostic instrument market.
27831. LAPSE:2023.11303
Industrial Application of Data-Driven Process Monitoring with an Automatic Selection Strategy for Modeling Data
February 27, 2023 (v1)
Subject: Process Monitoring
Keywords: autoencoder, fault detection and diagnosis, industrial process safety, information entropy, real-time industrial application of process monitoring method
The increasing scale of industrial processes has significantly motivated the development of data-driven fault detection and diagnosis techniques. The selection of representative fault-free modeling data from operation history is an important prerequisite to establishing a long-term effective process monitoring model. However, industrial data are characterized by a high dimension and multimode, and are also contaminated with both outliers and frequent random disturbances, making automatic modeling data selection a great challenge in industrial applications. In this work, an information entropy-based automatic selection strategy for modeling data is proposed, based on which a general real-time process monitoring framework is developed for a large-scale industrial methanol to olefin unit with multiple operating conditions. Modeling data representing normal operating conditions are automatically selected with only a few manually defined normal samples. A long-term effective process monitor... [more]
27832. LAPSE:2023.11302
Optimum Volume Fraction and Inlet Temperature of an Ideal Nanoparticle for Enhanced Oil Recovery by Nanofluid Flooding in a Porous Medium
February 27, 2023 (v1)
Subject: Energy Systems
Keywords: enhanced oil recovery, flooding, mathematical model, optimum volume fraction, porous media, temperature inlet
Nowadays, oil companies employ nanofluid flooding to increase oil production from oil reservoirs. Herein the present work, a multiphase flow in porous media was used to simulate oil extraction from a three-dimensional porous medium filled with oil. Interestingly, the finite element method was used to solve the nonlinear partial differential equations of continuity, energy, Darcy’s law, and the transport of nanoparticles (NPs). The proposed model used nanofluids (NFs) empirical formulas for density and viscosity on NF and oil relative permeabilities and NP transport equations. The NPs thermophysical properties have been investigated and compared with their oil recovery factor (ORF) to determine the highest ORF. Different NPs (SiO2, CuO, and Al2O3) were used as the first parameter, keeping all parameters constant. The simulation was run three times for the injected fluid using the various NPs to compare the effects on enhanced oil recovery. The second parameter, volume fraction (VF), has... [more]
27833. LAPSE:2023.11301
Thermodynamic Nature of SiO2 and FeO in Flux O Potential Control Subject to Submerged Arc Welding Process
February 27, 2023 (v1)
Subject: Process Control
Keywords: Calphad, flux, oxides, slag, submerged arc welding
SiO2 and MnO are the essential components dictating flux O potential subject to submerged arc welding. Due to the lack of thermodynamic data on the flux properties in early trials, the roles of SiO2 and FeO in the determination of the flux O potential remain nebulous, and conclusions are often conflicting with each other. Within this framework, through the analysis of the fluxes of 23 formulas at the full coverage of acid and basic fluxes with a basicity index spanning from 0.5 to 5.6, attempts are made to obtain a better understanding of the thermodynamic interconnection between oxides (SiO2 and FeO) and the flux O potential, and to clarify the controversial conclusions raised by different investigators. In particular, a thermodynamic approach has been proposed to simulate the equilibrium FeO activity, during which no measurement of the slag composition is needed. It is revealed that the simulated equilibrium FeO activity is feasible to evaluate the flux potential for both acid and ba... [more]
27834. LAPSE:2023.11300
Improving Process Efficiency at Pediatric Hospital Emergency Department Using an Integrated Six-Sigma Simulation Methodology
February 27, 2023 (v1)
Subject: Energy Systems
Keywords: DMAIC, healthcare engineering, healthcare improvements, Lean Six Sigma, simulation applications
Inadequate staffing and long waiting times in hospital emergency rooms are key concerns that can have a negative impact on patient safety and health, as well as the hospital’s overall performance. The purpose of this paper is to investigate the scope of combining the DMAIC (define, measure, analyze, improve, and control) methodology with discrete event simulation and to explore its successful deployment in the Jordanian healthcare sector. The study discussed in this paper is based on a case study conducted utilizing the DMAIC and simulation technique and its application in reducing waiting time and enhancing overall system efficiency in Jordan’s Princess Rahma hospital’s pediatric emergency department. The study shows improvements in the performance of the process and thus productivity in the emergency department through adapting the combined Six Sigma DES methodology. The cycle time of the process was reduced by 73% of the present value, while simultaneously enhancing the total perfor... [more]
27835. LAPSE:2023.11299
The Safety and Efficacy of the Protease Inhibitors Lopinavir/Ritonavir as Monotherapy or Combined with Interferon in COVID-19 Patients
February 27, 2023 (v1)
Subject: Numerical Methods and Statistics
Keywords: COVID-19, interferon, lopinavir, meta-analysis, ritonavir
Enzyme inhibitors are frequently used to treat viral illnesses. Protease inhibitors are a promising class for combating novel and life-threatening viral infections. This research aimed to evaluate the efficacy and safety of lopinavir/ritonavir monotherapy or lopinavir/ritonavir plus interferon for the treatment of COVID-19. The PubMed, Scopus, Web of Science, and Cochrane Library databases were searched for English articles with full texts available online. ReviewManager software was used to conduct a meta-analysis, subgroup analysis, and sensitivity analysis. Following the creation of the protocol, the collected sources were sorted into categories and evaluated for quality. Risk and hazard ratios and the random effects model were implemented, with statistical heterogeneity assigned using the Higgins I2 statistic. Lopinavir/ritonavir, with or without interferon, was associated with a nonsignificant higher mortality rate (odds ratio [OR] 1.29; 95% confidence interval [CI] 0.95 to 1.761;... [more]
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