Heterogeneous Production Research Articles

Optimization of heterogeneous Catalyst-assisted fatty acid methyl esters biodiesel production from Soybean oil with different Machine learning methods

There is a growing attention to the bio and renewable energies due to fast depletion of fossil fuels as well as the global warming problem. Here, we developed a modeling and simulation method by means of artificial intelligence (AI) for prediction of the bioenergy production from vegetable bean oil. AI methods are well known for prediction of complex and nonlinear process. Three distinct Adaptive Boosted models including Huber regression, LASSO, and Support Vector Regression (SVR) as well as artificial neural network (ANN) were applied in this study to predict actual yield of Fatty acid methyl esters (FAME) production. All boosted utilizing the Adaptive boosting algorithm. The important influencing parameters on the biodiesel production such as the catalyst loading (CAO/Ag, wt%) and methanol to oil (Soybean oil) molar ratio were selected as the input variables of models while the yield of FAME production was selected as output. Model hyper-parameters were tuned to maintain generality while improving prediction accuracy. The models were evaluated using three distinct metrics Mean Absolute Error (MAE), Root Mean Square Error (RMSE), and R2. Error rates of 8.16780E-01, 4.43895E-01, 2.06692E + 00, and 3.92713 E-01 were obtained with the MAE metric for boosted Huber, SVR, LASSO and ANN models. On the other hand, the RMSE error of these models were about 1.092E-02, 1.015E-02, 2.669E-02, and 1.01174E-02, respectively. Finally, the R-square score were calculated for boosted Huber, boosted SVR, and boosted LASSO as 0.976, 0.990, 0.872, and 0.99702, respectively. Therefore, it can be concluded that although the boosted SVR and ANN models were better models for prediction of process efficiency in terms of error, but all algorithms had high accuracy. The optimum yield of 83.77% and 81.60% for biodiesel production were observed at optimum operating values from boosted SVR and ANN models, respectively.

Market heterogeneity and the relationship between competition and price dispersion: Evidence from the U.S. airline market

Previous studies agree that competition influences price dispersion, however there is disagreement on the direction of the effect. To explain this contradiction in findings we include a measure not typically considered in competitive analysis, the level of market heterogeneity. We find that the response of price dispersion to changes in competition is conditioned by differentiation. When products in a market are homogenous, increasing competition reduces price dispersion, while in a market with heterogeneous products, the same increase in competition increases price dispersion. We include an output attribute index as a control for market heterogeneity and test our method on 73,981 observations of airfare data from 2002 through 2016. The implication of our findings for policymakers is that the traditional measures of market concentration do not determine the level of competition alone. Decisions on allowing or disallowing mergers should consider market heterogeneity, not just concentration. The results of this work contribute toward extending knowledge on the effect of competition on price dispersion and introduce a method of measuring market differentiation.

Inter‐sectoral relative price, inflation and structural transformation

AbstractWhile the pattern of composition of sectoral output and consumption are well stylised during growth and structural transformation of an economy, the evidence on the movement of inter‐sectoral relative price is mixed across countries. This paper investigates how demand and supply side forces simultaneously shape structural transformation and the path of relative price in a two‐sector economy comprising an agricultural and a non‐agricultural sector. The model incorporates non‐homothetic preference, heterogeneous sectoral production functions with heterogeneous and exogenous total factor productivity growth. We further investigate how the equilibrium path of relative price contributes to inflation measured by proportionate changes in the aggregate price level which is an index of sectoral prices. We find that the equilibrium rate of inflation is always positive during structural transformation. The rate of inflation increases with increase in growth rate of the non‐agricultural sector and with a higher preference for agricultural goods, and reduces with an increase in the growth of the agricultural sector.

Chemical Triphosphorylation of Oligonucleotides.

The 5'-triphosphate is an essential nucleic acid modification found throughout all life and increasingly used as a functional modification of oligonucleotides in biotechnology and synthetic biology. Oligonucleotide 5'-triphosphates have historically been prepared in vitro by enzymatic methods. However, these methods are limited to natural RNA oligonucleotides, have strong sequence preferences, and tend to produce heterogeneous products. New methods of chemical triphosphorylation complement both the reduced cost of automated oligonucleotide synthesis by phosphoramidite chemistry and the diverse range of nucleotide modifications now available. Thus, the synthesis of oligonucleotide triphosphates of arbitrary sequence and length, and optionally containing various nonnatural modifications, is now accessible. This paper presents the appropriate methods and techniques for chemical triphosphorylation of oligonucleotides using salicyl phosphorochloridite and pyrophosphate. This method uses commercially available reagents, is compatible with most oligonucleotides prepared by standard solid-phase synthesis methods, and can be completed in 2 h following oligonucleotide synthesis, before deprotection and purification. Two uses of chemically triphosphorylated oligonucleotides as substrates for catalytic RNA enzymes are demonstrated, including the synthesis of a mirror-image version of the hammerhead ribozyme from nonbiological L-RNA triphosphates.

Chemical Triphosphorylation of Oligonucleotides

The 5′-triphosphate is an essential nucleic acid modification found throughout all life and increasingly used as a functional modification of oligonucleotides in biotechnology and synthetic biology. Oligonucleotide 5′-triphosphates have historically been prepared in vitro by enzymatic methods. However, these methods are limited to natural RNA oligonucleotides, have strong sequence preferences, and tend to produce heterogeneous products. New methods of chemical triphosphorylation complement both the reduced cost of automated oligonucleotide synthesis by phosphoramidite chemistry and the diverse range of nucleotide modifications now available. Thus, the synthesis of oligonucleotide triphosphates of arbitrary sequence and length, and optionally containing various nonnatural modifications, is now accessible. This paper presents the appropriate methods and techniques for chemical triphosphorylation of oligonucleotides using salicyl phosphorochloridite and pyrophosphate. This method uses commercially available reagents, is compatible with most oligonucleotides prepared by standard solid-phase synthesis methods, and can be completed in 2 h following oligonucleotide synthesis, before deprotection and purification. Two uses of chemically triphosphorylated oligonucleotides as substrates for catalytic RNA enzymes are demonstrated, including the synthesis of a mirror-image version of the hammerhead ribozyme from nonbiological L-RNA triphosphates.

Development of multiple machine-learning computational techniques for optimization of heterogenous catalytic biodiesel production from waste vegetable oil

Multiple machine learning models were developed in this study to optimize biodiesel production from waste cooking oil in a heterogenous catalytic reaction mode. Several input parameters were considered for the model including reaction temperature, reaction time, catalyst loading, methanol/oil molar ratio, whereas the percent of biodiesel production yield was the only output. Three ensemble models were utilized in this study: Boosted Linear Regression, Boosted Multi-layer Perceptron, and Forest of Randomized Tree for optimization of the yield. We then found their optimized configurations for each model, namely hyper-parameters. This critical task is done by running more than 1000 combinations of hyper-parameters. Finally, The R2-Scores for Boosted Linear Regression, Boosted Multi-layer Perceptron, and Forest of Randomized Tree, respectively, were 0.926, 0.998, and 0.992. MAPE criterion revealed that the error rates for boosted linear regression, boosted multi-layer perceptron, and Forest of Randomized Tree was 5.68 × 10-2, 5.20 × 10-2, and 9.83 × 10-2, respectively. Furthermore, utilizing the input vector (X1 = 165, X2 = 5.72, X3 = 5.55, X4 = 13.0), the proposed technique produces an ideal output value of 96.7 % as the optimum yield in catalytic production of biodiesel from waste cooking oil.

How to regulate vaping products to advance cancer prevention: Evidence from online stores.

e22502 Background: The use of electronic cigarettes has significantly increased in the past decade, and online stores are one of the most common outlets for e-cigarette users to purchase vaping products. The goal of this study is to examine the appeal of different e-liquid flavors to vapers, using a revealed preference method to estimate consumer demand. Methods: We collected data on e-liquid sales prices, volume (in ml), and a variety of product flavors, from online vaping stores using web data extraction. We standardized prices for e-liquid products and used the hedonic pricing model to assess the associations between standardized e-liquid prices and flavors, controlling for nicotine concentration (in mg) and product VG/PG ratio. In total, we collected data of 10,870 e-liquid products from four popular online vaping stores that sell nationwide across the U.S. Results: Higher e-liquid prices (standardized to $/ml) are associated with higher nicotine concentrations. E-liquid products with fruit tobacco flavors are associated with higher sales prices. E-liquid prices are higher when VG/PG ratio deviates from 70/30 except for 90/10: the prices of e-liquid products with a 90/10 VG/PG ratio are lower than the prices of products with a 70/30 ratio. All of the findings above are statistically significant at a 5% level. Conclusions: Higher nicotine concentration and fruit flavors are associated with higher e-liquid prices in national online vaping stores, suggesting that they are preferred attributes and are in greater demand among vapers in the market of heterogeneous e-liquid products.

Microfluidic screening and genomic mutation identification for enhancing cellulase production in Pichia pastoris

BackgroundPichia pastoris is a widely used host organism for heterologous production of industrial proteins, such as cellulases. Although great progress has been achieved in improving protein expression in P. pastoris, the potential of the P. pastoris expression system has not been fully explored due to unknown genomic impact factors. Recently, whole-cell directed evolution, employing iterative rounds of genome-wide diversity generation and high-throughput screening (HTS), has been considered to be a promising strategy in strain improvement at the genome level.ResultsIn this study, whole-cell directed evolution of P. pastoris, employing atmospheric and room temperature plasma (ARTP) mutagenesis and droplet-based microfluidic HTS, was developed to improve heterogenous cellulase production. The droplet-based microfluidic platform based on a cellulase-catalyzed reaction of releasing fluorescence was established to be suitable for methanol-grown P. pastoris. The validation experiment showed a positive sorting efficiency of 94.4% at a sorting rate of 300 droplets per second. After five rounds of iterative ARTP mutagenesis and microfluidic screening, the best mutant strain was obtained and exhibited the cellulase activity of 11,110 ± 523 U/mL, an approximately twofold increase compared to the starting strain. Whole-genome resequencing analysis further uncovered three accumulated genomic alterations in coding region. The effects of point mutations and mutant genes on cellulase production were verified using reconstruction of point mutations and gene deletions. Intriguingly, the point mutation Rsc1G22V was observed in all the top-performing producers selected from each round, and gene deletion analysis confirmed that Rsc1, a component of the RSC chromatin remodeling complex, might play an important role in cellulase production.ConclusionsWe established a droplet-based microfluidic HTS system, thereby facilitating whole-cell directed evolution of P. pastoris for enhancing cellulase production, and meanwhile identified genomic alterations by whole-genome resequencing and genetic validation. Our approaches and findings would provide guides to accelerate whole-cell directed evolution of host strains and enzymes of high industrial interest.

Categorically right? How firm-level distinctiveness affects performance across product categories

In their pursuit of “optimal distinctiveness,” firms need to simultaneously adhere to norms and stand out from the competition. Using longitudinal data from Amazon Launchpad, an online B2C marketplace for entrepreneurial products, we offer a multi-level perspective on optimal distinctiveness from a consumer goods market in which firms are active across different and heterogeneous product categories. Arguing along categorization, organizational identity, and the fit with audiences' theory of value, we challenge the assumption that firm-level distinctiveness, i.e., the distinctiveness of a firm's organizational identity and category claims, delivers equal benefits to all products it offers and showcase the decisive role of product category context. In product categories that share less overlap with other categories and thus occupy a more distinct position in the classification system, products offered by firms with high firm-level distinctiveness benefit, whereas in product categories that share frequent relations to other categories and thus occupy a non-distinct position, products do not benefit at all. This offers researchers and managers alike a new and more nuanced perspective on firm-level distinctiveness: It is not invariably efficient in addressing audiences once the “optimal” level is found, but requires careful consideration of both the firm-level appeal and the product category in which a firm seeks to operate. Firm-level distinctiveness provides firms with the means to increase the differentiation of their own products, yet this effect is most meaningful in product categories with an increasingly distinct position.

Monitoring multiple quality attributes of a complex Fc-fusion protein during cell culture production processes by mD-LC-MS peptide mapping

Fc-fusion proteins represent a successful class of biopharmaceutical products. They are considered highly heterogeneous products due to the common degradation of amino acids that occurs during their production in upstream and downstream processes (e.g., oxidation and deamidation) and, above all, their complex glycosylation profile. Multi-dimensional liquid chromatography-mass spectrometry (mD-LC-MS) has recently gained much interest for process analytical technology, enabling the integration of this analytical technology in production and purification environments. In this study, an online mD-LC-MS/MS peptide mapping method was developed for monitoring multiple quality attributes, including the N-glycosylation state of a complex Fc-fusion protein, which is made by combining two heavily glycosylated cytokines with an Fc domain. This fully automated workflow includes sample purification, reduction, digestion, peptide mapping, and subsequent mass spectrometric analysis. Two immobilized enzyme cartridges based on trypsin and Lys-C protease were employed to generate a detailed glycosylation mapping, as trypsin allowed the identification of only one of four glycosylation sites, while Lys-C was more informative for two other sites. Site-specific glycosylation information such as antennarity, sialyation, and core fucosylation state was also determined. In addition to glycans, other post-translational modifications could be monitored simultaneously during the cell culture production processes by the mD-LC-MS/MS approach. In summary, the generated data demonstrate the applicability of mD-LC-MS for the monitoring and trending of multiple attributes for complex antibody formats over production processes in an automated and fast manner, compared to the complex and time-consuming traditional offline assays.

Order beyond Equilibrium: Ludwig Lachmann's Bridging of Seemingly Irreconcilable Traditions

Abstract Throughout his career, Ludwig M. Lachmann theorized about how economies and societies achieve order in an uncertain world full of heterogeneous agents, heterogeneous production factors, and multilayered subjectivity. This article traces how he began his research agenda by expanding the conventional equilibrium framework of the 1930s to include (potentially diverging) expectations but gradually abandoned price coordination as the sole source of order in an economy. Instead, he set out to formulate an institutional theory of socially embedded plan coordination, which transcended the traditional division between commerce and community. This article illustrates this shift in Lachmann's focus by using two of his neglected German publications. Additionally, it lays out how Lachmann's effort in the “thinking in orders” tradition was principally rooted in his dissatisfaction with approaches to economics that reduced it to a “pure logic of choice.” Lachmann instead conceived of his discipline as being something closer to Max Weber's “socioeconomics,” and in this he was strongly influenced by the German historical school. This article explains how, ironically, this tradition, which historically positioned itself in stark opposition to the Austrian school, has—through the mediation of Lachmann—had considerable influence on the recent history of the Austrian school in the United States.

Multi-approach LC-MS methods for the characterization of species-specific attributes of monoclonal antibodies from plants

In this work, an analytical platform based on the use of chromatography and mass spectrometry (MS), has been applied to the characterization of Rituximab (RTX) obtained from two plant expression systems (rice and tobacco) in comparison to the mammalian cell-derived reference monoclonal antibody (mAb). Different chromatographic approaches, hyphenated to high resolution MS (HRMS), were applied to RTX structural investigation both at middle- and peptide level. In particular, cation exchange chromatography (CEX), size exclusion chromatography (SEC), reversed phase (RPLC) and hydrophilic interaction liquid chromatographic (HILIC) methods were developed and applied on intact mAbs, IdeS-, and trypsin digests in order to address critical attributes such as primary structure, glycan composition, species-related heterogeneity, glycosylation degree, charge variants, aggregation tendency and enzymatic stability. All the collected data highlight the features and criticalities of each production approach. Production in rice results in a heterogeneous but stable product over time, suggesting the absence of proteases in seeds; while tobacco expression system leads to more homogeneous glycosylation, but protein stability seems to be a critical issue probably due to the presence of proteases. This analytical strategy represents a robust support to scientists in the selection and optimization of the best plant expression system to produce recombinant humanized mAbs.

Enhanced secondary organic aerosol formation during dust episodes by photochemical reactions in the winter in Wuhan

To investigate the effect of frequently occurring mineral dust on the formation of secondary organic aerosol (SOA), 106 volatile organic compounds (VOCs), trace gas pollutants and chemical components of PM2.5 were measured continuously in January 2021 in Wuhan, Central China. The observation period was divided into two stages that included a haze period and a following dust period, based on the ratio of PM2.5 and PM10 concentrations. The average ratio of secondary organic carbon (SOC) to elemental carbon (EC) was 1.98 during the dust period, which was higher than that during the haze period (0.69). The contribution of SOA to PM2.5 also increased from 2.75% to 8.64%. The analysis of the relationships between the SOA and relative humidity (RH) and the odd oxygen (e.g., OX = O3 + NO2) levels suggested that photochemical reactions played a more important role in the enhancement of SOA production during the dust period than the aqueous-phase reactions. The heterogeneous photochemical production of OH radicals in the presence of metal oxides during the dust period was believed to be enhanced. Meanwhile, the ratios of trans-2-butene to cis-2-butene and m-/p-xylene to ethylbenzene (X/E) dropped significantly, confirming that stronger photochemical reactions occurred and SOA precursors formed efficiently. These results verified the laboratory findings that metal oxides in mineral dust could catalyse the oxidation of VOCs and induce higher SOA production.

Effects of linking national carbon markets on international macroeconomics: An open-economy E-DSGE model

Linking carbon markets in different economies has become an important form of international climate cooperation. However, the complex socioeconomic effects of linking carbon markets need to be fully assessed. This article develops an open-economy environmental dynamic stochastic general equilibrium (E-DSGE) model that incorporates international trade, asymmetric economies, and heterogeneous production sectors. Based on the example of the linkage between EU and China carbon markets, we analyze the international macroeconomic effects of linking standalone national carbon markets. The main findings are as follows: 1) The linked carbon market improved total social welfare of China and the EU, but led to an uneven distribution of social welfare across regions. 2) China and the EU had better economic performances under a linked carbon market than under two separate carbon markets; moreover, the linked carbon market amplified expansionary effects and mitigated negative cross-border spillover effects. 3) Both separate and linked carbon markets functioned as automatic stabilizers of the economy; the linked carbon markets reduced economic fluctuations in the face of supply-side shocks, while the separate carbon markets reduced economic fluctuations in the face of demand-side shocks.

The Resilience of FDI to Natural Disasters Through Industrial Linkages

When do multinationals show resilience during natural disasters? To answer this, we develop a simple model in which foreign multinationals and local firms in the host country are interacted through input-output linkages. When natural disasters seriously hit local firms and thus increase the cost of sourcing local intermediate inputs, most multinationals may leave the host country. However, they are likely to stay if they are tightly linked with local suppliers and face low trade costs of importing foreign intermediates. We further provide a number of extensions of the basic model to incorporate, for example, multinationals with heterogeneous productivity and disaster reconstruction.

Crop minimum support price versus cost subsidy: Farmer and consumer welfare

Besides using earmark budget to support farmer cost subsidies, governments in many developing countries use minimum support price (MSP) as an alternative subsidy scheme to (i) safeguard farmers' incomes against vagaries in crop price and (ii) ensure sufficient crop production. Among different MSP schemes, we focus on the credit‐based MSP scheme under which a government will not take any possession of a crop; instead, it will credit farmers if the prevailing market price is below the prespecified MSP. In this paper, we consider a market consisting of infinitesimally small, rational, and strategic farmers (with heterogeneous production costs) who face market and yield uncertainties. Our equilibrium analysis reveals that (i) although both cost subsidy and MSP induce more production, cost subsidy leads to a higher crop production than MSP; (ii) MSP improves farmer's and consumer's surpluses; however, cost subsidy improves consumer's surplus but it can decrease farmer's surplus, which is unexpected; (iii) although both programs achieve the same optimal net value (i.e., sum of farmer's and consumer's surpluses minus shortage cost and expenditure), MSP always offers higher farmer's surplus than cost subsidy; and (iv) it is beneficial to invest only in cost subsidy, in both cost subsidy and MSP, and only in MSP, when the budget availability is low, moderate, and high, respectively, so that the net surplus (i.e., sum of farmer's and consumer's surpluses less the shortage cost) is also maximized along with the net value generated being maximized.

The unintended consequences of meritocratic government hiring

In an attempt to mitigate the negative effects of partisan hiring, many governments around the world have adopted meritocratic hiring of public employees. This paper shows that meritocratic government hiring can have unintended negative consequences on macroeconomic aggregates. In many countries, public employees enjoy considerable job security and generous compensation schemes; as a result, many talented workers choose to work for the public sector, which deprives the private sector of productive potential employees. This, in turn, reduces firms’ incentives to create jobs, increases unemployment, and lowers GDP. To quantify the effects of this novel channel, we extend the standard Diamond–Mortensen–Pissarides model to incorporate workers of heterogeneous productivity and a government that fills public sector jobs based on merit. We calibrate the model to aggregate data from Greece and perform a series of counterfactual exercises. We find that the adverse effects of meritocratic hiring on TFP, GDP, and unemployment are sizeable.

Detection and attribution of changes in cultivated land use ecological efficiency: A case study on Yangtze River Economic Belt, China

Improving the cultivated land use ecological efficiency (CLUE) to obtain greater agricultural output at a lower environmental cost, is an important part of effective management of land resources and sustainable intensification (SI). However, when evaluating CLUE, the existing research ignores the heterogeneity of the production environment of different agricultural production units, which leads to a “distortion effect”. To address this, this study focuses on the Yangtze River Economic Belt (YREB) in China as the study area and uses a three-stage super-efficiency slacks-based measure-undesirable (three-stage super-efficiency SBM-U) model to evaluate CLUE after excluding the interference of a heterogeneous agricultural production environment. In addition, we constructed ordinary least squares (OLS) and geographically weighted regression (GWR) models to analyze the driving mechanism of CLUE. The results indicate that environmental factors have a significant impact on the evaluation results of CLUE. Ignoring environmental factors leads to an overestimation of CLUE in areas with better environmental conditions, and vice versa. Second, due to the difference in input–output structure and the varied difficulty in production factor substitution, the driving mechanism of CLUE is spatiotemporal non-stationarity. During the study period, gross domestic product per capita, and farmland management scale had a positive effect on CLUE, while industrialization level had a negative effect. The impact of fiscal support for agriculture changed from insignificant to significant, in terms of improving CLUE in the western YREB. The influence direction of the multiple cropping index and agricultural planting structure changes from positive to negative and is concentrated in the east of the YREB. As a result, a series of measures are proposed to promote the improvement of CLUE and realize SI.

Application Research of Soft Computing Based on Machine Learning Production Scheduling

An efficient and flexible production system can contribute to production solutions. These advantages of flexibility and efficiency are a benefit for small series productions or for individual articles. The aim of this research was to produce a genetic production system schedule similar to the sustainable production scheduling problem of a discrete product assembly plant, with more heterogeneous production lines, and controlled by one-time orders. First, we present a detailed mathematical model of the system under investigation. Then, we present the IT for a solution based on a soft calculation method. In connection with this model, a computer application was created that analyzed various versions of the model with several practical problems. The applicability of the method was analyzed with software specifically developed for this algorithm and was demonstrated on a practical example. The model handles the different products within an order, as well as their different versions. These were also considered in the solution. The solution of this model is applicable in practice, and offers solutions to better optimize production and reduce the costs of production and logistics. The developed software can not only be used for flexible production lines, but also for other problems in the supply chain that can be employed more widely (such as the problem of delivery scheduling) to which the elements of this model can be applied.

Scale-Up of a Heterogeneous Photocatalytic Degradation Using a Photochemical Rotor-Stator Spinning Disk Reactor.

Many chemical reactions contain heterogeneous reagents, products, byproducts, or catalysts, making their transposition from batch to continuous-flow processing challenging. Herein, we report the use of a photochemical rotor–stator spinning disk reactor (pRS-SDR) that can handle and scale solid-containing photochemical reaction conditions in flow. Its ability to handle slurries was showcased for the TiO2-mediated aerobic photodegradation of aqueous methylene blue. The use of a fast rotating disk imposes high shear forces on the multiphase reaction mixture, ensuring its homogenization, increasing the mass transfer, and improving the irradiation profile of the reaction mixture. The pRS-SDR performance was also compared to other lab-scale reactors in terms of water treated per reactor volume and light power input.