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ChatGPT is a versatile conversational Artificial Intelligence model that responds to user input prompts, with applications in academia and various sectors. However, crafting effective prompts can be challenging, leading to potentially inaccurate or contextually inappropriate responses, emphasizing the importance of prompt engineering in achieving accurate outcomes across different domains. This study aims to address this void by introducing a methodology for optimizing interactions with Artificial Intelligence language models, like ChatGPT, through prompts in the field of engineering. The approach is called GPEI and relies on the latest advancements in this area; and consists of four steps: define the objective, design the prompt, evaluate the response, and iterate. Our proposal involves two key aspects: data inclusion in prompt design for engineering applications and the integration of Explainable Artificial Intelligence principles to assess responses, enhancing transparency. It combines insights from various methodologies to address issues like hallucinations, emphasizing iterative prompt refinement techniques like posing opposing questions and using specific patterns for improvement. This methodology could improve prompt precision and utility in engineering. [ABSTRACT FROM AUTHOR]

The variability of potato cultivars and environments in the production area of Nariño-Colombia, demands the adjustment of agronomic recommendations for the improvement of crop management. Physiological behavior and yield of four short-cycle potato cultivars were evaluated: Solanum tuberosum Phureja groups (Mambera, Ratona Morada and Criolla Colombia) and Andigena (Morasurco), under three environments, characterized edaphoclimatically (AH1, AH2, and AH4) and three fertilization levels. The yield components did not present differences between these levels, except for AH2, where level 3 surpassed the others in yield, and AH3 for harvest index with differences between levels. Regarding the cultivars, there were statistical differences in all environments; the highest yield was obtained by Ratona Morada and Mambera in AH4, Criolla Colombia in AH1, and a homogeneous behavior for Morasurco in all environments. In AH1 and AH2 the physiological indexes were similar in proportion and occurrence, while in AH4 the behavior was variable, with higher values in Morasurco and Mambera. ANOVA and discriminant analysis of principal components (DAPC) differentiated Morasurco from Phureja cultivars and Criolla Colombia from Ratona and Mambera. The grouping of environments in the DAPC ratifies the classification of the environments. The nutritional requirements of the genotypes can be limited by elements different from those evaluated; the productivity was mainly influenced by the environments; Mambera and Ratona Morada are established as alternatives in the AH4 environment, and Criolla Colombia and Morasurco in the other environments. [ABSTRACT FROM AUTHOR]

Contextualization: In the coffee production system, the seedling stage is a determining factor in the success of the implementation and behavior of the crop. In this stage, the nutrition is a very relevant factor. Knowledge gap: The use of substrates with diverse origins for the implementation of seedbeds in coffee makes difficult a correct diagnosis of fertility. For this reason, the nutrition in this phase of the productive system is based on recommendations and generalized formulas, that do not consider the differential needs of the varieties used and their state at the time of transplantation. Purpose: The objective of this research was: evaluating the effect of Urea, DAP and KCl fertilizers and mixtures of these on the growth of coffee seedlings (variety Castillo) during the seedling stage. Methodology: The work was carried out in 2019, at the farm La Quinta, in the municipality of Consacá (Nariño-Colombia), at 1.650 meters above sea level, using a completely randomized design with eight treatments and eight repetitions distributed this way: 2.17g of Urea + 0.7g of DAP; 4.3g of DAP; 3.3g of KCl; 0.6g of Urea + 4.3g of DAP; 2.1g of Urea + 3.3g of KCL; 4.3g of DAP + 3.3g of KCl; 2.1g of Urea + 4.3g of DAP + 3.3g of KCl and a control without application. It was carried out an analysis of variance with these variables: height, number of leaves, dry and fresh weight of the seedlings, besides a functional growth analysis with biweekly evaluations. Results and conclusions: The treatment with DAP presented the highest height (20.65cm), greater fresh and dry weight of stem (3.86g; 1.43g), greater total dry weight (5.33g) greater leaf area (350.8cm2) and leaf area index (0.99). The Treatment with Urea + DAP showed better net assimilation rate (0.00029g cm d) and better crop growth rate (2.87e g cm d). The Treatment with DAP and KCl reached the highest value for relative growth rate (0.047g g d). In all cases, phosphorus became conclusive for the seedling stage, due to its presence was related to superior physiological behavior. [ABSTRACT FROM AUTHOR]

In this work we apply the lightcone bootstrap to a four-point function of scalars in two-dimensional conformal field theory. We include the entire Virasoro symmetry and consider non-rational theories with a gap in the spectrum from the vacuum and no conserved currents. For those theories, we compute the large dimension limit (h/c ≫ 1) of the OPE spectral decomposition of the Virasoro vacuum. We then propose a kernel ansatz that generalizes the spectral decomposition beyond h/c ≫ 1. Finally, we estimate the corrections to the OPE spectral densities from the inclusion of the lightest operator in the spectrum. [ABSTRACT FROM AUTHOR]

The commissioning of new plants is a fundamental part of the energy production process, the objective of this article is to present a methodology that allows Improving the Commissioning of wind and solar photovoltaic plants, for this the ISO 55000: 2014 and ISO 14224 standards were taken: 2016 and this results in a four-phase methodology: Phase 1: ISO 14224 Taxonomy Standard. Phase 2: ISO 31000 Standard Criticality. Phase 3: RCM (Reliability Centred Maintenance) Methodology. Phase 4: Contributions of the phases to the requirements of the ISO 55001 standard. It is concluded that by applying this methodology the commissioning of wind and solar photovoltaic plants is improved. [ABSTRACT FROM AUTHOR]

Abstract This paper addresses the techno-economic, energetic and environmental assessment of the indirect and direct production of bioenergy using Pinus patula (PP) as raw material. Ethanol and synthesis gas are evaluated as main products through biochemical (fermentation) and thermochemical (gasification) routes, respectively. The complete characterization of the raw material was performed aiming to determine the chemical, proximate and elemental composition of the PP that is used as starting point for the simulation procedure. Mass and energy balances were obtained from the simulation of both processes using the software Aspen Plus v9.0. Different economic criteria such as Net Present Value (NPV) and Payback Period (PBP) were used to determine the profitability of both processes. The overall energy efficiency was calculated considering the relation between the energy content of the products and the energy content of the inputs (raw materials and utilities). The environmental assessment involves an attributional life-cycle assessment (LCA) of different systems such as seedlings production, PP cultivation, harvesting and collection, and the evaluated processes using a cradle-to-gate approach. As a result, the production of ethanol evidenced a low production cost (0.549 USD/L), higher energy efficiency (45.1%) and higher CO 2 emissions (0.17 kg per MJ EtOH) in comparison to the biomass gasification. Highlights • Pinus Patula as a potential raw material for direct and indirect bioenergy production. • Steam explosion linked to SSF make the ethanol production a profitable process. • Clear energy policies are required to improve the feasibility of biomass gasification. • The conversion of syngas in electricity has a negative effect on the energy efficiency. • High energy needs in the biochemical route contribute to the high environmental impact. [ABSTRACT FROM AUTHOR]

Purpose: To determine the effectiveness and harms of bladder-preserving trimodal therapy (TMT) as a first-line treatment versus radical cystectomy (RC) plus radical pelvic lymphadenectomy in the treatment of muscle-invasive bladder cancer in terms of overall survival.Methods: We included parallel clinical trials and prospective and retrospective cohort studies that included patients older than 18 years old, diagnosed with muscle-invasive bladder cancer, who underwent TMT compared with RC. The planned comparison was TMT versus RC plus pelvic lymphadenectomy as first-line treatment. The primary outcome was overall survival (OS) and secondary outcomes were salvage cystectomy and cancer-specific survival and progression-free survival. A search strategy was designed for MEDLINE, CENTRAL, Embase, and LILACS. We saturated information with conference abstracts, in progress clinical trials, literature published in non-indexed journals, and other sources of gray literature. Standardized tools assessed the risk of bias independently. We performed the statistical analysis in R v3.4.1 and effect sizes were reported in terms of hazard ratios (HR) and the corresponding 95% confidence intervals (95%CI). Accordingly, we used a random effect model due to the statistical heterogeneity found in included studies.Results: We found 2682 records with the search strategies and, finally, 11 studies were included in the quantitative analysis. The summary HR for OS was 1.06 95%CI (0.85-1.31) I2 = 77%, showing no statistical difference. Regarding cancer-specific survival, the summary HR was 1.23 95%CI (1.04-1.46) I2 = 14%. On the other side, for the progression-free survival, the summary HR was 1.11 95%CI (0.63-1.95) I2 = 78%. Only one study described HR for adverse events (1.37 95%CI 1.16-1.59).Conclusion: We found no differences in overall survival and progression-free survival between these two interventions. Nonetheless, we found that cancer-specific survival favored patients who received radical cystectomy. [ABSTRACT FROM AUTHOR]

This reflection article is a product of the study titled "La narrativa museográfica basada en el guión curatorial" (INV-ING-2368) funded by the Research Vice-Chancellor's Office at Universidad Militar Nueva Granada (UMNG). Publications, comments, and interviews with experts related to the museum environment support this work. The article is organized as follows: The first section examines interactivity as a complement for interpretation and human mediation in museography from the standpoints of design and engineering. Such interactivity employs narratives as a structural component for the communication between the public and the exhibition. The second part analyzes museum disciplines and activities, as well as the roles of the staff that conduct them. Furthermore, it emphasizes the importance of curatorship and museography, the figure of the curator as a narrator, the museographer as the implementer of museum exhibitions, and the key role of the curatorial script for those endeavors. The conclusion is that interactive museographic narratives are developed by a combination of interdisciplinary knowledge that comes together in the curatorial statement created by the museum staff, and those narratives are structured as different discussion channels that promote interaction. [ABSTRACT FROM AUTHOR]

Laguna del Maule Volcanic Complex (LMVC, Southern Andes of Chile) has been experiencing large rates (ca. 30 cm/yr) of surface uplift as detected since 2008 by satellite geodetic measurements. Previous works have modeled the source of this deformation as an inflating rectangular sub-horizontal sill underlying LMVC at 5 km depth, which is supposedly related to an active process of magmatic replenishment of a shallow silicic reservoir. However little is known about the tectonic context on which this activity is taking place, particularly its relation with crustal seismicity that could help understanding and monitoring the current deformation process. Here we present the first detailed characterization of the seismic activity taking place at LMVC and integrate it with structural data acquired in the field in order to illuminate the possible connection between the ongoing process of surface uplift and the activation of crustal faults. Our main finding is the recognition of repetitive volcano-tectonic (VT) seismic swarms that occur periodically between 2011 and 2014 near the SW corner of the sill modeled by InSAR studies. A cross-correlation analysis of the waveforms recorded for these VT events allows identifying three different seismic families. Families F1 and F3 share some common features in the stacked waveform and its locations, which markedly differ from those of family F2. Swarms belonging to this later family are more energetic and its energy was increasing since 2011 to a peak in January 2013, which coincide with maximum vertical velocities detected by local GPS stations. This points to a common process relating both phenomena. The location of VT seismic swarms roughly coincides with the intersection of a NE-SW lineament with a WNW-ESE lineament. The former shows clear field evidences of dextral strike-slip that are fully consistent with one nodal plane of focal mechanism for well-recorded F2 events. The conjugate nodal plane of these focal mechanisms could coincide with the WNW-ESE lineament, for which our field reconnaissance suggests a dominant normal motion. Events belonging to families F1 and F3 are also dominantly strike-slip but with some mixture with thrust and normal components. Our results, in conjunction with results of previous authors, suggest a complex mechanical interaction between the arrangement of crustal faults forming the structural framework on which the magmatic plumbing system of LMVC is emplaced and the inflating source at depth. [ABSTRACT FROM AUTHOR]

Objective. To determine the global incidence of penile cancer. Methods. A systematic review and meta-analysis of observational studies was performed, with no limits on their language of publication. Analyses were performed using Stata 13 statistical software. A random-effects model was used, according to the heterogeneity found in the studies. The main outcome was expressed in terms of age-standardized incidence. Results. A total of 23 studies were eligible, with 71 156 penile cancer patients in 86 countries. According to the review conducted, the estimated age-standardized incidence of penile cancer worldwide is 0.84 cases per 100 000 person-years (95% confidence interval: 0.79-0.89). Romania reported the highest incidence, 7.26 per 100 000 person-years, between 1983 and 1987; however, some countries in Latin America and Africa reported an incidence of between 2.0 and 5.7 per 100 000. Conclusions. Penile cancer is considered a rare malignancy due to its already-known, particularly low incidence rate. The estimated age-standardized incidence rate by the world standard population today is 0.84 cases per 100 000 person-years. There were no significant differences in the incidence rate of penile cancer with respect to the distribution by continent or the trend over time. [ABSTRACT FROM AUTHOR]

In this note, we explore the correspondence between four-dimensional flat space S-matrix and two-dimensional CFT proposed by Pasterski et al. We demonstrate that the factorisation singularities of an n-point cubic diagram reproduces the AdS Witten diagrams if mass conservation is imposed at each vertex. Such configuration arises naturally if we consider the 4-dimensional S-matrix as a compactified massless 5-dimensional theory. This identification allows us to rewrite the massless S-matrix in the CHY formulation, where the factorisation singularities are re-interpreted as factorisation limits of a Riemann sphere. In this light, the map is recast into a form of 2 d/2 d correspondence. [ABSTRACT FROM AUTHOR]

Purpose: To determine the efficacy of phosphodiesterase type 5 inhibitors (PDE5i) as medical expulsive therapy (MET) for the treatment of distal ureteral calculi. Materials and Methods: A search strategy was conducted in the MEDLINE, CENTRAL, and Embase databases. Searches were also conducted in other databases and unpublished literature. Clinical trials were included without language restrictions. The risk of bias was evaluated with the Cochrane Collaboration's tool. An analysis of random effects due to statistical heterogeneity was conducted. The primary outcome was the expulsion rate of the distal ureteral calculus in 28 days. The secondary outcomes were the time to expulsion, side effects of treatment, and amount (mg) of nonopioid analgesia. The measure of the effect was the risk difference (RD) with a 95% confidence interval (CI). The planned interventions were PDE5i vs. placebo, tadalafil vs. placebo, and tadalafil vs. tamsulosin. Results: Four articles were included in the qualitative and quantitative analysis. Records of 580 patients were found among the four studies. A low risk of bias was shown for the majority of the study items. The calculi expulsion rate had an RD of 0.26 (95% CI, 0.15-0.37) and a less prolonged expulsion as a secondary outcome with a mean difference of -4.39 days (95% CI, -6.69 to -2.09) in favor of PDE5i compared with the placebo. No significant difference was found for these outcomes when comparing tadalafil with tamsulosin. Conclusions: Compared with a placebo, PDE5i could be effective as MET for the treatment of distal ureter calculi. [ABSTRACT FROM AUTHOR]

This paper examines the methodology used by Kepler to discover a quantitative law of refraction. The aim is to argue that this methodology follows a heuristic method based on the following two Pythagorean principles: (1) sameness is made known by sameness, and (2) harmony arises from establishing a limit to what is unlimited. We will analyse some of the author's proposed analogies to find the aforementioned law and argue that the investigation's heuristic pursues such principles. [ABSTRACT FROM AUTHOR]

Banana-plantain fibers (BPFs) were treated with acetic anhydride (AA), epichlorohydrin (EP), and an acetic anhydride-epichlorohydrin blend (AA_EP). Natural fiber-polyester composites (PCs) were fabricated using untreated and treated BPF by the hand lay-up technique. Modified BPF Raman and Infrared spectroscopy (ATR-FTIR) analysis revealed losses of lignin and hemicelluloses and new chemical bonds that confirmed the replacement of part of the raw fiber hydroxyl groups, which gave rise to a degree of hydrophobicity in the treated fibers. This change altered their water sorption isotherms, swelling behavior in water, impedance spectroscopy, and XRD analysis. Assays of water absorption and tensile resistance for untreated BPF (U) and modified BPF polyester composites demonstrated a remarkable reduction in water intake, whereas tensile strength was maintained ( P < 0.05) for the modified BPF polyester composites. POLYM. COMPOS., 37:2960-2973, 2016. © 2015 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

One limitation of livestock farming in the Colombian Caribbean is the decline in production and quality of forage in times of drought or rain. The aim of this study was to evaluate forage production and nutritional quality of three varieties of cassava (SM 2546-40, SM 1511-6 and SM 2081-34) under three planting densities (40,000, 55,000 and 70,000 plants ha-1) and three harvest ages (75, 90 and 105 days). The experiment was conducted at the Research Center Turipaná-Corpoica, in 2011, under a split-split-plot design with three replications. Green fodder production (GFP), dry matter production (DMP), crude protein production (CPP), crude protein content (CPC), neutral detergent fiber (NDF), acid detergent fiber (ADF) and ash were evaluated. In the wet season (May-August), the GFP and DMP was 150% higher than in the dry season (January to April) and the protein 100% higher. Cassava variety SM 2081-34 produced greater GFP and DMP, and lower content of ADF. In the three planting densities, GFP and DMP were similar, but with 55,000 and 700,000 plants / ha, the CPP was higher. After 105 days, the highest GFP, DMP and CPP were obtained, whereas at 75 days, the forage had lower contents of NDF and ADF, and higher protein content (CPB). After 105 days, the ash content was higher. SM 2081-34 variety produced more dry matter and protein at 105 days with 55,000 ha-1 plants. [ABSTRACT FROM AUTHOR]

In the this paper, we show a methodological summary to simulate and understand the complex behavior of energy market models. The goal of this work is to propose the business approach of system dynamics, with the dynamical systems and its mathematical point of view. Additionally we present two ways to perform sensitivity analysis on models based on system dynamics. The first one is numerical sensitivity analysis, and the second one is using Poincaré maps. Finally, we conclude that there is complementarity between the mathematical framework and the business applications for the market. This will allow us to achieve greater exploitation for our models. [ABSTRACT FROM AUTHOR]

We use the elimination theory to explicitly construct the ( n − 3 ) ! order polynomial in one of the variables of the scattering equations. The answer can be given either in terms of a determinant of Sylvester type of dimension ( n − 3 ) ! or a determinant of Bézout type of dimension ( n − 4 ) ! . We present a recursive formula for the Sylvester determinant. Expansion of the determinants yields expressions in terms of Plücker coordinates. Elimination of the rest of the variables of the scattering equations is also presented. [ABSTRACT FROM AUTHOR]

This study investigates the technical, economic and environmental performances for producing ethanol and furfural from Pinus patula bark, on a biorefinery concept. This was done through experimental, techno-economic and environmental assessments. The experimental analysis considered the physicochemical characterization of the raw material and three pre-treatment methods: (i) dilute acid, (ii) alkali, and (iii) liquid hot water. The alkali method showed the highest yield (50%) and the pentose rich hydrolysate was used to produce furfural (yield 91%). The solid from the pre-treatment stage was enzymatically hydrolyzed (max. concentration 63 g/l), and the hexose rich solution was used as substrate for producing ethanol (0.42 g ethanol/g sugars). The obtained experimental yields were used as the basis to build a process model to generate mass and energy balances, from which the techno-economic and environmental assessments are derived. Based on different levels of heat integration, three scenarios were assessed: (Sc.1) non-integrated, (Sc.2) fully energy integrated and (Sc.3) fully integrated plus cogeneration scheme. Results revealed that by increasing the level of energy integration, the biorefinery system can be profitable with a positive net present value (Sc.3: 184.54 M.USD/y) and a payout period within the project׳s life-time (Sc.3: 2.22 y). The annualized production costs can be decreased up to 84% and 66% for scenario 3 in comparison with scenarios 1 and 2, respectively. From the environmental point of view, the biorefinery system is positively affected by increasing the level of energy integration. The potential environmental impact can be reduced up to 74% and 66% for scenario 3, in comparison with scenarios 1 and 2, respectively. [ABSTRACT FROM AUTHOR]

The comparison between the structured and unstructured models was performed in order to determine the mathematical approach that best fit the biological synthesis of anthocyanins from plant cell cultures. A structured model was used for the production of secondary metabolites using cell cultures of strawberry (Fragaria ananassa) taking into account the cell viability of pigmented and non-pigmented cells. Moreover, growth and anthocyanin production of cell suspensions of grape (Vitis vinifera) were evaluated by an unstructured model. Both models adequately described the growth of plant cells and substrate uptake. However, anthocyanin production is intrinsically related to cell growth, especially degradation thereof; therefore the structured model was selected to describe the production of this secondary metabolite. [ABSTRACT FROM AUTHOR]

In this work, a biorefinery system including castor bean seeds and microalgae is used as a case study to evaluate the integration of second and third generation biorefineries. A biorefinery concept was applied for the combined production of polyol, ethylene-glycol, omega-3 acid, biodiesel, methanol and heat and power from castor bean and microalgae. Castor bean cake and microalgae paste were used to feed a biomass-fired system (BIGCC), where part of CO 2 produced in flue gas is captured and employed as substrate for microalgae growth. To evaluate the performance of this biorefinery concept three scenarios based on different levels of mass and energy integration were modeled and assessed from techno-economic and environmental points of view. The scenario with the best economic and environmental performances was the one including full mass integration, full heat integration, and cogeneration scheme. [ABSTRACT FROM AUTHOR]

The energy "Trilemma" seeks to develop an electricity market which simultaneously ensures environmental quality, security of supply, and economic sustainability. The objective of this paper is to present the "Trilemma" energy as the latest trend in the design of energy policy. For this, a theoretical framework is presented in sections 2 and 3, in section 4 and 5 the importance of security of supply and economic sustainability are discussed, respectively. In section 6 the energy "trilemma" is presented, in section 7 a brief state of the art is showed. Finally in section 8, it is approached three different electricity markets. It is concluded that the regulator has passed in recent years from encouraging a liberalized market scheme, to promote a scheme based on intervention through policies that affect the market competitiveness but allow achieving its environmental goals. [ABSTRACT FROM AUTHOR]

Following the work in [1], where the massive ABJM model in 2 +1dimensions was shown to have an abelian reduction to the relativistic Landau-Ginzburg, and motivated by the implications for condensed matter through AdS/CFT, weshow that a FI deformation of N = 4SYM in 3 +1 dimensions with a mass term can also be reduced to a relativistic Landau-Ginzburg model, with the possibility of coupling it to a real scalar, whereas the simply mass deformed N = 4SYM reduces only to a massive φ4model (scalar QED) coupled to a real scalar. Westudy the classical solutions of the model, inparticular vortex solutions. [ABSTRACT FROM AUTHOR]

We propose a state from the two-dimensional conformal field theory on the orbifold ( T 4 ) N / S ( N ) as a dual description for a pulsating string moving in AdS 3 . We show that, up to first order in the deforming parameter, the energy in both descriptions has the same dependence on the mode number, but with a non-trivial function of the coupling. [ABSTRACT FROM AUTHOR]

Polyhydroxybutyrate is a type of biopolymer that can be produced from hydrolyzed polysaccharide materials and could eventually replace polypropylene and polyethylene, being biodegradable, biocompatible and produced from renewable carbon sources. However, polyhydroxybutyrate is not still competitive compared to petrochemical polymers due to their high production costs. The improvement of the production processes requires a search for new alternative raw materials, design of the pretreatment technique and improvement in the fermentation and separation steps. In addition, if the polyhydroxybutyrate production is coupled into a multiproduct biorefinery it could increase the economic and environmental availability of the process through energy and mass integration strategies. In this work alternatives of energy and mass integrations for the production of polyhydroxybutyrate into a biorefinery from residual banana (an agro-industrial waste) were analyzed. The results show that the energetic integration can reduce up to 30.6% the global energy requirements of the process and the mass integration allows a 35% in water savings. Thus, this work demonstrates that energy and mass integration in a biorefinery is a very important way for the optimal use of energy and water resources hence decreasing the production cost and the negative environmental impacts. [ABSTRACT FROM AUTHOR]

In the Aufbau, Carnap mentioned the possibility of carrying out a logical construction of emotions in a way completely analogous to the construction of the sensory qualities. This task, however, was never accomplished. I intend to show that the logical construction suggested by Carnap requires significant changes in the construction protocols in the Aufbau. In particular, amendments which allow to recognize the genuine duration of emotions. I also suggest protocols of recognition for the direction and the expression of emotions. [ABSTRACT FROM AUTHOR]

One of the most important uses of artificial neural networks is to forecast non-linear time series, although model-building issues, such as input selection, model complexity and parameters estimation, remain without a satisfactory solution. More of research efforts are devoted to solve these issues. However, other models emerged from statistics would be more appropriated than neural networks for forecasting, in the sense that the process of model specification is based entirely on statistical criteria. Multivariate adaptive regression splines (MARS) is a statistical model commonly used for solving nonlinear regression problems, and it is possible to use it for forecasting time series. Nonetheless, there is a lack of studies comparing the results obtained using MARS and neural network models, with the aim of determinate which model is better. In this paper, we forecast four nonlinear time series using MARS and we compare the obtained results against the reported results in the technical literature when artificial neural networks and the ARIMA approach are used. The main finding in this research, it is that for all considered cases, the forecasts obtained with MARS are lower in accuracy in relation to the other approaches. [ABSTRACT FROM AUTHOR]

Abstract: We discuss the relation between correlation functions of twist-two large spin operators and expectation values of Wilson loops along light-like trajectories. After presenting some heuristic field theoretical arguments suggesting this relation, we compute the divergent part of the correlator in the limit of large ʼt Hooft coupling and large spins, using a semi-classical world-sheet which asymptotically looks like a GKP rotating string. We show this diverges as expected from the expectation value of a null Wilson loop, namely, as , μ being a cut-off of the theory. [Copyright &y& Elsevier]

The prediction of thermodynamic properties can be considered as the first stage of the mitigation processes proposals. In this paper, the influence of phase equilibrium calculations over separation performance was analyzed, using Greenhouse Gases (GHG) mixtures. Eleven GHG mixtures (CO2-CO-N2O-SO2) were analyzed through the Peng-Robinson, Predictive Soave-Redlich-Kwong and Perturbed Chain - Statistical Associating Fluid Theory thermodynamic models. After, topologic thermodynamics tool and conceptual design were used to predict the results of distillation separation. The thermodynamic analysis was completed with the calculations of binary and ternary phase equilibrium. The results showed the carbon monoxide concentration as issue in simulation procedure and, therefore, it affected separation calculations. [ABSTRACT FROM AUTHOR]

Abstract: In this paper a techno-economic analysis for bioethanol production in Africa for Tanzania case is presented. It is shown conversion pathways from sugar cane juice and molasses, at three levels of technological schemes, where the first one includes a selection of widely conventional technologies, the second level with a more sophisticated fermentation technology and the third level using a different broth and solid treatment for ethanol production. A simulation procedure was taking into account in order to evaluate the conversion pathways schemes using different scenarios of raw material pretreatment, using Aspen Plus software, that include productivity analysis and energy requirements for each process configuration. Also an economical evaluation of each technology level and each scenario is shown. A comparison and discussions for each technological level and each scenario for bioethanol production in Tanzania is presented. These results served as the basis to draw recommendations on technological and economic feasibility aspects for the implementation of a national biofuel production programme in Africa. The study helped to identify the best technological schemes for producing fuel-grade alcohol from the various raw materials analysed. [Copyright &y& Elsevier]

In the processes of production and purification of thermally unstable products, the design plays an important role since it determines the costs and quality of the obtained product. In this work, we present a mathematical model for a falling-film molecular distiller based on the equations of balance of heat, material and momentum for a multicomponent mixture, which is applied to the concentration of Lippia citrodora essential oil. The model consisted of coupled differential equations that were solved using the Crank-Nicholson method for obtaining the profiles of temperature and molar fractions of the components in the evaporation and condensation surfaces. The essential oil is obtained with concentrations from 47.79% to 89.21% of citral in the bottoms and 41.62% to 72.23% of limonene in the top. [ABSTRACT FROM AUTHOR]

Five technological schemes for propionic acid production from raw glycerol were designed, simulated, and economically assessed. Fermentative scenarios considered two different qualities of glycerol: 88 and 98 wt % with concentrations in the fermentation media from 20 to 50 g/L. Raw glycerol (60 wt %) was considered as the feedstock feeding the production process in all cases; then a purification process of raw glycerol up to the required quality was used. Simulation processes were carried out using Aspen Plus, while economic assessments were performed using Aspen Icarus Process Evaluator. Propionic acid recovery and purification processes were based on reactive–extraction with tri-n-octylamine using ethyl acetate as extractant agent. This technology results in energy-intensive processes with total energy consumption ranging from 120.4 to 138.9 MJ/kg. However, further significant improvements could be obtained using energy integration techniques. On the other hand, it was found that the production costs are directly related to the fermentation stage and decrease as follows: (i) increasing the glycerol concentration, (ii) decreasing the glycerol purity, and (iii) increasing the glycerol consumption. [ABSTRACT FROM AUTHOR]

Abstract: In this work, the hierarchical decomposition methodology was used to conceptually design the production of fuel ethanol from sugarcane. The decomposition of the process into six levels of analysis was carried out. Several options of technological configurations were assessed in each level considering economic and environmental criteria. The most promising alternatives were chosen rejecting the ones with a least favorable performance. Aspen Plus was employed for simulation of each one of the technological configurations studied. Aspen Icarus was used for economic evaluation of each configuration, and WAR algorithm was utilized for calculation of the environmental criterion. The results obtained showed that the most suitable synthesized flowsheet involves the continuous cultivation of Zymomonas mobilis with cane juice as substrate and including cell recycling and the ethanol dehydration by molecular sieves. The proposed strategy demonstrated to be a powerful tool for conceptual design of biotechnological processes considering both techno-economic and environmental indicators. [Copyright &y& Elsevier]

Recently, Ghiassi, Saidane and Zimbra [Int J Forecasting, vol. 21, 2005, pp. 341-362] presented a dynamic-architecture neural network for time series prediction which performs significantly better than traditional artificial neural networks and the ARIMA methodology. The main objective of this article is to prove that the original DAN2 model can be rewritten as an additive model. We show that our formulation has several advantages: First, it reduces the total number of parameters to estimate; second, it allows estimating all the linear parameters by using ordinary least squares or ridge regression; and, finally, it improves the search for the global minimum of the error function used to estimate the model parameters. To assess the effectiveness of our approach, we estimate two models for one of the time series used as a benchmark when the original DAN2 model was proposed. The results indicate that our approach is able to find models with similar or better accuracy than the original DAN2. [ABSTRACT FROM AUTHOR]

Background: The burnout syndrome is defined as an inadequate response to chronic job stressors. In the last years the burnout syndrome has acquired importance. Materials and methods: A cross-sectional study was designed to evaluate the prevalence and psychosocial factors associated with the burnout syndrome in family doctors and specialists which work in several institutions in Manizales, Caldas, and Virginia, Risaralda. The questionnaire evaluated demographic factors, prevalence of burnout syndrome, family functioning and personal relationships. Results: 227 physicians were evaluated, (132 family and 95 specialists). A burnout frequency was found of 17.6%, 26.4% with high exhaustion, 26.1% presented depersonalization and 7.2% of low personal fulfillment. A significant relationship between burnout and extra work activity was found (p = 0.039), observing that the burnout syndrome occurs in 25.8% of physicians who do not perform any activity outside work during the week and in 14.3% of the physicians who engaged activities outside work. A significant relation (p = 0.009) was also found with family functioning, observing that 37.5% of the physicians who have moderate dysfunction tend to present burnout syndrome. Conclusions: The burnout syndrome is common in this population, and is related to family functioning and the number of hours dedicated to activities outside work. [ABSTRACT FROM AUTHOR]

Fuel ethanol production has become one of the most studied processes in the last two decades because of the need to decrease its production cost and improve its energetic performance. The most promising raw material is lignocellulosic biomass because of its negligible cost and high availability. On the other hand, most research has focused on single steps and has not considered the whole process design. Aspen Plus allowed designing this kind of process while considering relevant aspects such as raw material composition and kinetic models of chemical and biological transformation. In this study fuel ethanol from rice hulls has been simulated considering the kinetic parameters for acid pretreatment, detoxification, and fermentation with the aim of assessing the energy performance of the process. In addition, the economic evaluation was accomplished using Aspen Process Economic Analyzer with the objective of calculating the production cost. It was found that the dilute acid pretreatment had a higher ethanol yield (347.25 L/t) and lower energy consumption (86.75 MJ/L) than liquid hot water pretreatment. However, the latter pretreatment had a lower production cost (US$0.4367/L); although when energy cogeneration and electricity sales were included in the analysis, dilute acid pretreatment became the most economic technology with a lower production cost (US$0.1918/L). [ABSTRACT FROM AUTHOR]

Abstract: Ordered mesoporous silicas MCM-41, HMS, SBA-15 (hexagonal), and MCM-48 (cubic) have been synthesized and functionalized with propylsulfonic acid groups by post-oxidation method. Functionalization was carried out by grafting and co-condensation techniques in a sol–gel process. This process required TEOS, MPTS and an appropriate surfactant as structure-directing agent. Synthesis methods were modified and adapted specifically from literature for each case. The materials were characterized by XRD, TGA, FT-IR, and SEM. The catalytic activity was tested over the esterification reaction to produce 1-butylacetate. The effects of mesophase and functionalization technique were related to the catalytic performance. The higher functionalization was reached by co-condensation technique, and the best ratio between catalytic performance and functionalization degree was exhibited by SBA-15, followed by MCM-41, HMS and MCM-48 in decreasing order. Substantial differences in catalytic activity were found for materials with hexagonal and cubic mesophase. [Copyright &y& Elsevier]

Abstract: In this work the vapor–liquid equilibria for nine binary mixtures (methanol+acetic acid, methanol+methyl acetate, methanol+water, methyl acetate+acetic acid, water+acetic acid, ethyl acetate+acetic acid, ethanol+acetic acid, ethanol+ethyl acetate and ethanol+water) at subatmospherical pressure (580mmHg) is presented. Peng–Robinson Stryjek–Vera equation of state coupled with the Wong–Sandler mixing rules were used for predicting phase equilibria of these mixtures. The measurements were developed using an apparatus with recirculation that can also be employed for liquid–vapor equilibrium with chemical reaction. [Copyright &y& Elsevier]

This article reports the results seen from adjusting a model of non-observable components to the monthly electrical power demand in Colombia from 1995:8 to 2006:1 in order to separate the underlying tendency of the periodical component associated with the annual cycle and study its behavior. Findings show that the periodical component has a stochastic behavior but such behavior does not broaden with an increased level in the series; likewise, the model indicates that the monthly growth in demand has a linear deterministic component, approximately constant during recent years, whose rises and falls have coincided with the rises and falls seen in the GDP. [ABSTRACT FROM AUTHOR]

Present work deals with the biotechnological production of fuel ethanol from different raw materials. The different technologies for producing fuel ethanol from sucrose-containing feedstocks (mainly sugar cane), starchy materials and lignocellulosic biomass are described along with the major research trends for improving them. The complexity of the biomass processing is recognized through the analysis of the different stages involved in the conversion of lignocellulosic complex into fermentable sugars. The features of fermentation processes for the three groups of studied feedstocks are discussed. Comparative indexes for the three major types of feedstocks for fuel ethanol production are presented. Finally, some concluding considerations on current research and future tendencies in the production of fuel ethanol regarding the pretreatment and biological conversion of the feedstocks are presented. [Copyright &y& Elsevier]

Abstract: Current fuel ethanol research and development deals with process engineering trends for improving biotechnological production of ethanol. In this work, the key role that process design plays during the development of cost-effective technologies is recognized through the analysis of major trends in process synthesis, modeling, simulation and optimization related to ethanol production. Main directions in techno-economical evaluation of fuel ethanol processes are described as well as some prospecting configurations. The most promising alternatives for compensating ethanol production costs by the generation of valuable co-products are analyzed. Opportunities for integration of fuel ethanol production processes and their implications are underlined. Main ways of process intensification through reaction–reaction, reaction–separation and separation–separation processes are analyzed in the case of bioethanol production. Some examples of energy integration during ethanol production are also highlighted. Finally, some concluding considerations on current and future research tendencies in fuel ethanol production regarding process design and integration are presented. [Copyright &y& Elsevier]

Abstract: Phase equilibrium for carbon dioxide+ n-alkanes (from methane to n-decane) asymmetric binary systems was calculated using Peng–Robinson Stryjek–Vera equation of state coupled with Wong–Sandler mixing rules. NRTL model was utilized for predicting the excess Helmholtz free energy. The second virial coefficient binary interaction parameter k 12 and NRTL model parameters τ 12 and τ 21 for carbon dioxide+ n-alkanes binary systems were optimized trough minimization of two different objective functions: one based on the calculation of the distribution coefficients, and the other one based on the determination of bubble point pressures. Generalized correlations for mixing rule parameters as a function of the n-alkane acentric factor and the equilibrium temperature were obtained from optimal parameters determined by the first objective function. Obtained results using both objective functions were satisfactory, but the estimation of the parameters calculated by the second objective function provided a better accuracy in vapor–liquid equilibrium prediction. [Copyright &y& Elsevier]

The theoretical principles of the simultaneous reaction-separation processes are presented. The simultaneous chemical and phase equilibria for multi-component mixtures are analysed, with presentation of phase diagrams for three and/or four components. These diagrams are the basis for the thermodynamic-topological analysis applied in the preliminary design of the extractive reaction/fermentation processes. It is developed in more detail in part two of this article. [ABSTRACT FROM AUTHOR]

In this paper, we analyze Virasoro conformal blocks in the limit when the operator exchange dimension is taking to be large in comparison with the other parameters dependence of the block. We do this by using Zamolodchikov's recursion relations. We found a dramatically simplified solution at leading order in an inverse power expansion in large exchange conformal dimension in terms of a quasi-modular form in an Eisenstein series representation. We compare this solution with existing results obtained previously by using AGT correspondence. [ABSTRACT FROM AUTHOR]

This study exposes the assessment of a piezo-actuated sensor for monitoring elastic variations (change in Young's modulus) of a host structure in which it is attached. The host structure is monitored through a coupling interface connected to the piezo-actuated device. Two coupling interfaces were considered (an aluminum cone and a human tooth) for the experimental tests. Three different materials (aluminum, bronze and steel) were prepared to emulate the elastic changes in the support, keeping the geometry as a fixed parameter. The piezo device was characterized from velocity frequency response functions in pursuance to understand how vibration modes stimulate the electrical resistance through electrical resonance peaks of the sensor. An impedance-based analysis (1–20 kHz) was performed to correlate elastic variations with indexes based on root mean square deviation (RMSD) for two observation windows (9.3 to 9.7 kHz and 11.1 to 11.5 kHz). Results show that imposed elastic variations were detected and quantified with the electrical resistance measurements. Moreover, it was demonstrated that the sensitivity of the device was influenced by the type of coupling interface since the cone was more sensitive than the tooth in both observation windows. As a final consideration, results suggest that bio-structures (fruits and bone, among others) could be studied since these can modify naturally its elastic properties. [ABSTRACT FROM AUTHOR]

Cassava (Manihot esculenta) is a woody bush extensively cultivated as an annual crop in tropical and subtropical regions for its edible starchy tuberous root, a major source of carbohydrates. The main residue from its cultivation is the cassava stalk, which is normally used as soil fertilizer or in culture propagation. The main goal of this paper is to evaluate two routes (biochemical and thermochemical) for bioenergy production (ethanol and synthesis gas—electricity) using cassava stalk as raw material. A detailed techno-economic and energy assessment is carried out based on the simulation approach of both conversion routes to determine the production costs of main products and the overall energy efficiency of the processes. The electricity production costs vary from 0.008 to 0.037 USD/MJ, whereas the ethanol production costs range from 1.11 to 2.02 USD/L (including subsidies). The change in the production costs was observed due to the assumptions of the model, e.g., cassava stalk, transportation, and enzyme costs. The overall energy efficiency of the gasification and ethanol fermentation was 68.7 and 25.1%, respectively. [ABSTRACT FROM AUTHOR]

Highlights • Lactic acid is produced from xylose and glucose using a genetically modified strain. • The modified strain presents yields very close to the theoretical. • The process was simulated to develop a technical and economic analysis. • The scale of production has great influence on the distribution of costs. • The industrial implementation of the strain is possible due to its versatility. Abstract In this work, d -lactic acid production was evaluated from a simulated hydrolysate of corn stover (32 g/L xylose, 42 g/L glucose) with the metabolically engineered Escherichia coli strain JU15. Based on the experimental results, a technical and economic analysis of the entire process was performed using the Aspen Plus software. As a result, it was possible to show that the strain can efficiently produce lactic acid from both sugars, reaching a final concentration of 40 g/L and a yield of 0.6 g lactic acid/g sugars. The process is economically viable at higher scales of 1000 tons/day. The cost distribution is influenced by the scale of the process; on a larger scale, the cost of raw materials represents a higher percentage of total cost than it does on smaller scales. The use of a metabolically engineered strain allows a better use of the sugars obtained from agroindustrial residues. [ABSTRACT FROM AUTHOR]