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• Experimental investigations on the solubility of Propylene and DME in PAG oil. • The form of NRTL and Heil interaction parameters was key to high model accuracy. • Two novel empirical correlations were proposed. • Single coefficient correlation: compact, explicit and robust to low amount of data. • DME most soluble refrigerant followed by Propylene and Propane. This work experimentally investigated the solubility of Propylene and Dimethyl Ether (DME) in polyalkylene glycol (PAG) oil. The solubility experimental data were used to fit different local composition models from the literature, the Wilson and Heil equations, and the Non-Random Two-Liquid (NRTL) model. Two new empirical correlations were proposed to decrease the deviation between experiments and the models. The first correlation used six fitting coefficients and resulted in an average deviation of 1.2 % for Propylene and 2.8 % for DME. The second empirical correlation was proposed with a single solubility coefficient (SSC) and a compact form, which allows solubility to be determined explicitly. The correlation resulted in average deviations from experimental data of 1.6 % for Propylene and 2.5 % for DME. Moreover, the SSC correlation showed performance robustness against the decrease of available data points. The correlation was used to compare the solubility of Propylene and DME with the solubility of Propane. At the same conditions, Propane showed the lowest solubility while DME resulted in the most soluble refrigerant. [ABSTRACT FROM AUTHOR]

Spiral blast freezing is a common unit operation used in food processing facilities for rapidly freezing a variety of foodstuffs. The purpose of a blast freezer is to generate high velocity, low temperature air flow over food products being conveyed within refrigerated enclosures to accomplish the freezing process. However, air flow patterns observed within field operating blast freezers are often suboptimal, resulting in diminished system performance. This paper applies a Monte Carlo simulation technique to a food product freezing simulation in order to identify velocity profiles that optimize the freezing process. A one-dimensional food product model is used to evaluate the interplay between the time variation in the magnitude of the air velocity over food products conveyed through the freezing system and the resulting dwell time needed to achieve a target product core temperature at the blast freezer exit. Temporal heat transfer coefficients derived from field measurements made in a newly installed spiral blast freezer serve as a basis to calibrate the one-dimensional product model. The results of the Monte Carlo analysis show freezing system performance is improved when high and stable air velocities over the product are achieved early in the freezing process dwell time. Air flow patterns within a freezing system that result in high air velocity later in the freezing process dwell time are suboptimal. Field-measured data on a newly installed spiral blast freezer showed this suboptimal air flow pattern and the use of baffling within the spiral enables improved airflow leading to an estimated 10 % increase in production throughput. [ABSTRACT FROM AUTHOR]

This paper analyzes the developing adiabatic two-phase flow after an expansion valve in an air conditioning system. R245fa and POE 32 mixture is used as the working fluid. The developing two-phase flow patterns are visualized in an 8 mm straight tube after the expansion valve from 15 to 595 mm. To explore the effect of fluid properties on the developing two-phase flow, the experimental results from previous research by the same authors are compared with those of R245fa in this paper. An image analysis technique and a one-dimensional developing two-phase flow model proposed in a previous paper by the same authors (Yao & Hrnjak, 2023c) are applied to both R134a and R245fa. The flow patterns near the expansion valve exhibit some similarities when comparing the two refrigerants. However, a significant contrast emerges in the presence of a greater number of droplets suspended within the vapor phase in the case of R245fa flow. This disparity is primarily attributed to R245fa's higher vapor velocity. Furthermore, R245fa exhibits a shorter developing length than R134a. For fully developed flow, R245fa showcases a more pronounced turbulent behavior, and the transition to annular flow happens at a lower vapor quality in comparison to R134a. All of these distinctions can be adequately accounted for by the proposed model. The developed flow patterns of both refrigerants are compared with some existing flow pattern maps. At last, a new flow pattern map is proposed based on the observed flow patterns in this research. [ABSTRACT FROM AUTHOR]

This paper applies an image analysis technique to quantify the two-phase flow videos after an expansion valve. This method first finds the liquid-vapor interface and then estimates the void fraction and velocity of each phase. This paper also proposes a one-dimensional developing two-phase flow model based on the force-momentum balance. The void fraction of the developing flow predicted by the model shows a similar trend to the quantified experiment data from image analysis: void fraction will decrease and then stabilize as flow develops along the tube. In essence, the change in void fraction and flow velocity is a result of unbalanced force in liquid and vapor phase. This model is also capable of estimating the distance to achieve fully developed flow after an expansion valve. The ability to predict two-phase flow behavior is not only important to the theoretical study of two-phase flow, but also critical to two-phase flow system design to optimize heat transfer and pressure drop. [ABSTRACT FROM AUTHOR]

• Precise predictive models for CO 2 frosting temperature were developed. • Machine learning algorithms of GPR and MLP were utilized for modeling. • The novel models showed excellent results for different natural gas mixtures. • The models provided excellent physical trends under different operating conditions. • The most effective operating factors on frosting temperature were identified. In this study, universal and precise predictive models for CO 2 frosting temperature in different natural gas mixtures were developed employing the machine learning algorithms of multilayer perceptron (MLP) and gaussian process regression (GPR). The models were verified by an extensive databank including 430 experimental samples collected from 7 published sources, enveloping a broad range of conditions in methane/CO 2 binary mixtures as well as the ternary mixtures of methane/CO 2 /ethane and methane/CO 2 /nitrogen. Both GPR and MLP models exhibited excellent predictions with total average absolute relative errors (AAREs) of 0.16% and 0.42%, and R2 values of 99.80% and 99.38%, respectively. The novel models use only 4 simple adjusted parameters, and they were found to be applicable for both binary and ternary mixtures with high precisions. In addition, the effects of each operating parameter on frosting temperature were studied, and the new models showed excellent physical trends. Subsequently, in order to provide more insight about the most effective factors on frosting temperature, a sensitivity analysis based on the present databank was performed. [ABSTRACT FROM AUTHOR]

The pandemic situation has forced teaching and learning practices around the world to reassess their systems and innovate in terms of ergonomics. Highly visible changes have overturned teaching and learning habits. Initially highly improvised, distance learning in Moroccan schools has taken its first steps through repeated trial and error until it has established itself as a possible educational tool. Teachers and decision-makers, in unison, are faced with the urgent need to reinvent education and combine it with technology. A plethora of formats and platforms are now part of the vocabulary of education. However, in addition to diligent health conditions, distance learning is required to break with the accidental nature of its advent and become an optional, alternative or even blended mode. This study looks at the forms of distance assessment that need to be implemented in order to capitalise on, verify and enhance learners' achievements. [ABSTRACT FROM AUTHOR]

In this research paper, we introduce an extension of the Gamma-Lindley distribution using a particular exponentiation of its cumulative distribution function, which offers a more flexible model for lifetime data. Another attractive feature of this extension is that it has several particular cases: Weibull, generalized Pareto, Lindley, exponential and Gamma-Lindley distributions. Different statistical properties of this distribution are explored, such as the density, failure rate and the rth moments. We attempt to prove that the extended Gamma-Lindley distribution is characterized by its truncated moment of order statistics. One of the main merits of this work lies in the fact that it provides the ability of this characterization to simulate the new distribution compared with the inverse transform sampling method. Estimation of the parameters using the tailed regression method is investigated. The COVID-19 real data evolution in Tunisia illustrates the performance of the EGL distribution compared with its special cases through some criteria such as the Kolmogorov-Smirnov test, Mean Squared error and Kullback-Leibler divergence. The predictive ability of the extended Gamma-Lindley distribution proved to provide a better fit to expect the number of deaths by Corona-virus in Tunisia in the future period. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the thermal behavior of water flows in a solar collector equipped with zig-zag tubes. To achieve this, a numerical simulation using CFD was conducted, which is a powerful tool for analyzing fluid-flow and heat transfer. The simulation employed the finite volume method to discretize the fluid domain and the SIMPLE algorithm to solve the pressure-velocity coupling. The simulation results indicated that the shape of the tubes significantly influenced the flow behavior and overall performance of the solar collector. Specifically, the temperature profiles at various times of the day showed that zig-zagshaped tubes enhanced the heat transfer coefficient, resulting in higher temperatures within the collector. Moreover, the zig-zag design increased the residence time of the fluid inside the collector, further improving its overall efficiency. These findings highlight the potential of utilizing zig-zag-shaped tubes to optimize the performance of solar water heating systems, which could have important implications for renewable energy applications. [ABSTRACT FROM AUTHOR]

In low-and middle-income countries, the cold chain that supports vaccine storage and distribution is vulnerable due to insufficient infrastructure and interoperable data. To bolster these networks, we developed a convolutional neural network-based fault detection method for vaccine refrigerators using datasets synthetically generated by thermodynamic modeling. We demonstrate that these thermodynamic models can be calibrated to real cooling systems in order to identify system-specific faults under a diverse range of operating conditions. If implemented on a large scale, this portable, flexible approach has the potential to increase the fidelity and lower the cost of vaccine distribution in remote communities. • Thermodynamic simulations can be used to generate datasets of refrigeration faults. • These time-series datasets can be used to train convolutional neural networks. • This approach can support the cold chain for vaccine distribution. [ABSTRACT FROM AUTHOR]

Despite advances in medical technology, mortality due to burn injuries remains significant. Scoring systems are aimed at allowing physicians to effectively and accurately predict the mortality of a given patient. Patients at a higher risk of death from burns include older patients over the age of 65, highseverity burn, presence of co-morbidities, and presence of inhalation injury. Constructing a burn prediction model also needs its own methodological standards. Hence, choosing a prediction model for predicting burn mortality requires careful analysis of its methodology. Attention towards mortality risk factors should be taken when treating burn patients. Tools such as burn prediction models prove helpful in aiding physicians to accurately and effectively predict a patient's mortality, stratify patient severity, and allocate resources appropriately, especially in settings where resources are scarce, such as natural disasters. Additionally, prediction models are used to monitor patient care and for research purposes. [ABSTRACT FROM AUTHOR]

In this third part on the "Transition from arithmetic to algebraic in the teaching of mathematics in high school" we reflect on the term modeling: modeling, in the sense that we use this word, can be based on a non-mathematical system as well as on a mathematical system. The didactic analysis of the curricular perspectives we have outlined reveals problems in the didactics of mathematics that underline the need for very close links, for a tenacious dialectic, which should be everyone's concern, between fundamental research in didactics and the development activities of the teaching system. In contrast, the present situation reveals the great superficiality of which the empirical and dogmatic tradition has made us unfortunate heirs. It is not enough to weaken, decide, and act to solve the problems we are and continue to be faced with. As in other fields, research is no longer that part of the dream in which high-growth societies could offer themselves as a bonus. It is up to it to explore on behalf of all, the avenues of the possible. [ABSTRACT FROM AUTHOR]

In Haiti, agricultural systems are highly vulnerable to climate change. This study aims to assess the relevance of a process of co-design of climate change adaptation strategies with producers in a highly vulnerable zone such as Haïti. Conducted in Saint Michel de l'Attalaye, the study was based on: (i) a diagnosis of the technical and economic performance of 24 farms representative of the three main types of adaptation strategies observed, and (ii) the co-design of innovative strategies with a smaller sample of 9 farmers. The results of the study show that the initial performances of the 24 farms in terms of covering family caloric needs, income, and greenhouse gas emissions are different for the three types of strategies. The diversification of agricultural production systems plays a crucial role in the performance measured. The strategies proposed by the 9 producers aim to increase this diversification while increasing sugar cane area in their production systems; however the changes thought out are incremental. More co-design loops could be considered to explore with farmers disruptive changes that would both favor an increase in production capacities of farms and climate change adaptation. This pilot study in Haïti could be replicated in other highly vulnerable areas to co-design innovative systems taking into account the specific constraints to which farmers are exposed. [ABSTRACT FROM AUTHOR]

• 3D moving-boundary model for water solidification in ice cubes is presented. • Experiments were performed in a purpose-built closed-loop wind-tunnel facility. • Ice cube of 145 ml with distilled, mineral, and filtered tap water was evaluated. • Ice cube was modeled as a pyramid trunk and Stefan's formulation was applied. • Deviations within a ± 10% error band were observed for all cases. The present work is aimed at putting forward a three-dimensional moving-boundary model to calculate the water solidification in ice trays subjected to operating conditions typically found in household appliances. To better understand the physical phenomena and validate the model, experiments were performed in a purpose-built closed-loop wind tunnel facility at -23 °C and air flow rate of 10 m³ h−1 using a single volume of 145 ml fed with distilled, mineral, and filtered tap water. The end of the solidification process was identified by monitoring the cooling curves with the aid of seven thermocouples placed within the ice cube. In the numerical front, the ice cube was modeled as a pyramid trunk and Stefan's formulation was applied to each of the domain boundaries so that the ice thickness could be calculated over time. Deviations within a ±10% error band were observed for all cases. A good agreement between the model predictions for the time evolution of the ice cube temperature and the experimental counterparts was also verified. In addition, literature data for the position of the solidification front and the remaining liquid fraction were fairly predicted by the model. [ABSTRACT FROM AUTHOR]

This study concerns to model the flow boiling heat transfer coefficient (HTC) in smooth helically coiled tubes. A dataset including 1035 samples was collected from 13 independent studies, enveloping a broad range of geometrical and operating conditions. The predictive capability of the earlier models was assessed for straight and coiled tubes by the analyzed database that they were not precise enough. Accordingly, a new empirical model based on the least square fitting method (LSFM) was constructed using seven input effective dimensionless factors. It was found that LSFM was not able to describe the complex and nonlinear nature of HTC in smooth helically coiled tubes. Furthermore, the intelligent method of genetic programming (GP) was utilized to obtain more accurate explicit correlation for HTC, which produced an acceptable average absolute relative error (AARE) of 17.35%. Finally, the machine learning approaches of multilayer perceptron (MLP), Gaussian process regression (GPR), radial basis function (RBF) was also implemented to model HTC in smooth coiled tubes. Although all intelligent based models provided excellent results, the GPR model outperformed the others with an average absolute relative error (AARE) of 5.93% for the tested dataset. In addition to the proposed models' performance, the most influential factors in controlling the boiling HTC in coiled tubes were also detected. [ABSTRACT FROM AUTHOR]

• A method of inherent capacity modulation for a linear compressor is proposed. • Experimental validation has been conducted. • The modulation characteristics of a linear compressor using R134a were numerically studied. • The inherent capacity modulation can make the linear compressor meet the cooling load. Conventional refrigeration compressors sized for peak cooling load actually operate at partial load mostly which could cause excessive on-off cycling loss. Linear compressor could overcome this challenge by varying the compressor stroke in response to transient cooling load. The present work establishes a numerical model for the capacity modulation of linear compressor using R134a through changing the input voltage to meet the cooling load. The numerical model contains a linear compressor model (including three sub-models describing the in-cylinder thermodynamic process, the piston mechanical dynamic process and the electrical part behaviour, respectively) and an input voltage modulation loop. Experimental data are collected for the validation of the numerical model. The results show that the capacity modulation, aiming to meet the cooling load within the error of 5%, can be achieved through varying the input voltage while fixing temperatures of heat exchangers. An increased voltage brings increased compressor stroke and mass flow rate in a linear trend with the heat exchanger temperature unchanged. Lower input voltage leads to higher motor efficiency due to lower copper loss. At a fixed condenser temperature and cooling load, the inherent capacity modulation can save energy with evaporator temperature increasing as the power consumption decreases. At condenser temperature of 50 °C, 40 °C and 30 °C, the CoP only changes by 1.5%, 0.9% and 2.7% when the cooling load changes from 100 W to 200 W. The inherent capacity modulation will allow the linear compressor to maintain a high annual efficiency for refrigeration. [ABSTRACT FROM AUTHOR]

Le présent article questionne l'accompagnement des étudiants dans l'enseignement supérieur, en temps de crise. Il aborde le concept dans une complémentarité de la visée praxéologique liée à l'expérience et celle heuristique relative au savoir scientifique, selon une approche paradigmatique. Par la suite, l'apport issu de l'action et de la théorie sur l'accompagnement est mobilisé dans des pratiques sociales de terrain basées sur les démarches participatives au sein d'un contexte libanais frappé par une série de crises aigües. Au final, l'alliance du savoir et de l'expertise aboutit à une modélisation de l'écoaccompagnement qui s'inscrit dans un paradigme chronosystémique, construit autour de cinq logiques interdépendantes : l'épistémologique, la pragmatique, l'axiologique, l'institutionnelle et la stratégique, favorisant l'émancipation de la personne et de la collectivité, entraînant celle de l'institution. [ABSTRACT FROM AUTHOR]

This work aimed to study petiole palm tree wastes (PTW) efficiency in removing two basic dyes: Rhodamine B (RB) and Victoria blue B (VBB) from aqueous solutions in single and binary systems under various experimental conditions including the effect of contact time, pH, initial concentration, and temperature. The PTW characterization shows that the PTW is a lingo-cellulosic material. The experimental results indicate that the removal of both dyes was relatively fast, spontaneous, exothermic and occurred on monolayers. Moreover, the adsorption competition between these two dyes on the adsorbent particles surface was important since the Langmuir's adsorption capacities were evaluated to 260.1; 440.1; 168.0; and 417.4 mg/g for RB and VBB in single and binary systems, respectively. These adsorption capacities, even in binary systems, are interesting compared to other raw materials and prove that this abundant agricultural waste can be considered as a promising material for an efficient dyes removal from aqueous effluents. [ABSTRACT FROM AUTHOR]

• New VLE data for HFC/HFO with R1234yf. • VLE data measured by means of static synthetic method. • VLE data correlated with Peng Robinson EoS. • Azeotropic behaviour for R1234yf + R134a and R152a are observed. Isothermal vapour−liquid equilibrium (VLE) for four binary systems involving R1234yf (R1234yf + R134a, R1234yf + R152a, R1234yf + R1233zd(E) and R1234yf + R1233xf) were measured at temperatures from 278.15 to 348.15 K. The experiments were conducted by means of a "static−analytic" apparatus with phase analysis via gas chromatography, with resulting uncertainties of 0.6 K for temperature, 8 kPa for pressure and a maximum of 0.007 for vapour and liquid mole fractions. The main advantage of the equipment is that vapour and liquid samples are taken from vapour and liquid phases by two capillary samplers (ROLSI®). The Peng Robinson Equation of State is considered to represent the experimental data. If possible, comparison between the new experimental data and prediction with REFPROP 10.0 software are realized. [ABSTRACT FROM AUTHOR]

• The critical properties of R1243zf + R1234yf and R1243zf + R245cb are studied based on a novel method • The critical point is determined via modeling vapor-liquid coexistence points to the combined equations of the scaling law and rectilinear diameters law. • Experimental VLE measurement of R1243zf + R1234yf and R1243zf + R245cb by the static-synthetic method. • The R1243zf + R1234yf and R1243zf + R245cb exhibit near-azeotropic behavior within a temperature range of 293.15 to 353.15 K. • Good agreement is obtained between experimental critical points and predictions from the PR-MC-MHV2 EoS. This work studies two binary mixtures of R1243zf + R1234yf and R1243zf + R245cb which can be possibly used as a long-term alternative refrigerant for heat pumps. We present critical property (critical temperature, pressure, density) and vapor liquid equilibrium (VLE) of R1243zf + R1234yf and R1243zf + R245cb two binaries. The maximum extended uncertainties (k=2) are estimated as U(T) = 0.21 K, U(p) = 0.048 MPa, and U(ρ) = 6.4 kg/m3 for critical property measurement, and U(T) = 0.06 K and U(p) = 0.015 MPa for bubble point measurement. The uncertainty of liquid-phase mole fraction is estimated less than 1.8 × 10−4. The critical property is investigated by a novel method that determines the critical point via modeling vapor-liquid coexistence points to the combined equations of the scaling law and rectilinear diameters law. The VLE of R1243zf + R1234yf and R1243zf + R245cb binary mixtures in the range of 293.45 to 353.55 K are studied by the static-synthetic method which determines the bubble point via the variable volume cell technique. The experimental bubble points are correlated by the Peng-Robinson (PR) equation of state (EoS) with vdW and MHV2 mixing rules. The modeling results are in good agreement with the measured data. The high temperature VLE of the two binary systems is predicted up to the critical point line by PR-MC-MHV2 model with the optimal binary parameters. [Display omitted] [ABSTRACT FROM AUTHOR]

Epidemiologists, medical geographers, and public health experts have long focused on city‐centred data in the description of epidemic occurrences. While incidence is collected locally, it is typically aggregated to first a city and from there to a regional resolution. Urban researchers have long noted that interurban travel flow directly affects urban populations and thus models based on a stable urban entity. Some have proposed that a "megaregion," based on one or another urban exchange network, is a more appropriate vehicle for the study of dynamic disease events. In this preliminary study, megaregions based on American commuter flow are used to study the early spread of H1N1 Type‐A Influenza in 2009—from three principal cities to surrounding towns and cities. The question was, first, whether these catchments would adequately capture the incidence of viral expansion in a region. Second, the question was whether a "wave‐like" pattern of orderly disease progression would be observed. Key Messages: Some have suggested that the volume of travel across broad urban networks requires a redefinition of traditional urban places.Megaregions have been proposed as catchment systems based on flow networks to redefine urban geographies in a manner that may be applied to infectious disease.Megaregions and Metropolitan Service Areas are tested here as catchments for the introduction of H1N1 Type‐A Influenza in cities in the United States. [ABSTRACT FROM AUTHOR]

This work has focussed on the development of an accurate method for testing and modelling the reaction kinetics involved in ammonia-salt adsorption reactions, something not achieved consistently to date. A Large Temperature Jump (LTJ) test cell has been developed for testing ammonia-salt reactions in real machine conditions. A Large Temperature Jump (LTJ) test cell has been developed for testing ammonia-salt reactions in real machine conditions. This was used to validate a new approach to modelling the behaviour and simulate the performance of chemisorption machines. A derivation of the heat transfer and thermodynamic equations are presented, and a finite difference model described which has been validated for the adsorption and desorption reactions of ammonia into halide salts within a porous matrix. The model is implemented in a MATLAB® program. Large Temperature Jump (LTJ) tests have been conducted on manganese chloride and barium chloride to validate the model and to identify the physical parameters which characterise the dynamic performance of the sorbent. The manganese chloride and barium chloride were impregnated in expanded natural graphite (ENG) (SGL SIGRATHERM®) board. The ENG board gave rise to practicable samples (31.5 mm OD ø over ½" tube) undergoing a desorption reaction in under 250 seconds with the fluid temperature 15°C above the equilibrium temperature, an order of magnitude faster than observed elsewhere. A new test method has been developed enabling an accurate single heat of reaction to be identified due to reduced hysteresis, which is reported for barium and manganese chloride. The model has been validated using experimental data from LTJ tests of two geometric configurations in radial heat transfer: discs heated/cooled from the outside radius ('tube-side') and annuli heated from the inner radius ('shell-side'). The empirical data obtained is a milestone towards designed and optimised salt generators. [ABSTRACT FROM AUTHOR]

• A mechanistic model is developed to predict two-phase flow distribution in BPHEs. • Vapor distribution is predicted by the phase separation models of two flow stages. • Liquid distribution is predicted by the pressure balance. • The developed model is validated by the experimental results. This paper presents a mechanistic model that predicts two-phase refrigerant distribution in brazed plate heat exchangers. The modeling of two-phase distribution is based on the flow visualization in the inlet header, in which the flow regime is identified to be periodic and one cycle includes two or three flow stages, given a fully developed stratified/stratified-wavy flow is present at the heat exchanger entrance. To predict the vapor refrigerant distribution, this model considers two different flow stages in the inlet header: for the top corner vapor flow, the vapor refrigerant distribution is predicted by the balance between the suction force (radial pressure gradient) and the axial momentum of each phase; for the vapor jet flow, the vapor refrigerant is assumed to be distributed evenly among the channels. The time ratio of the two flow stages is estimated by assuming the irregular large-amplitude rolling waves in the feeding tube, which lead to the vapor jet flow in the header, to have the most dangerous wavelength and their traveling time can be related to the liquid slug frequency. The apparent vapor refrigerant distribution is the time average of the vapor distributions at the two stages. For the liquid refrigerant distribution, it is predicted by imposing an equal total pressure drop for each flow path. The proposed model is validated against the experimental results: quantified two-phase refrigerant distribution, heat exchanger capacities, pressure profiles in the headers, and surface temperature of the sidewalls. [ABSTRACT FROM AUTHOR]

• Thermal conductivity, specific heat and surface tension of PVE VG68 oil were measured. • Models of thermophysical properties of PVE oil and R32/PVE mixture were proposed. • Force balance analysis was performed on oil transport in suction line. • An oil retention correlation with satisfactory accuracy was proposed. Advanced PVE was developed as the coupled lubricant oil for the alternative refrigerant R32 and R32/PVE will be a potential working pair of R32 refrigeration systems. This paper presented modeling study of physical properties of PVE lubricant oil with viscosity grade 68 and R32/PVE mixture. Thermal conductivity, specific heat and surface tension of PVE oil were measured experimentally. New calculation models for properties of pure oil were developed based on the experimental data. Moreover, the solubility, miscibility and viscosity of R32/PVE mixture were also well correlated with the new correlations. Further, a parametric analysis was performed to study oil transport and retention characteristics in compressor suction line, based on the force balance method. A new consolidated database for oil retention was amassed from six existing literatures, including 187 data points. A new correlation for oil retention was established by incorporating influence factors derived from the parametric analysis. The validation result showed that the oil retention correlation exhibits satisfactory prediction accuracy, which achieved mean absolute error of 14.43% and 87.70% of data fell within ±30% error bands. The property models and oil retention correlation could serve as tools to accurately predict oil retention amount of suction line with R32/PVE mixture. [ABSTRACT FROM AUTHOR]

• Three different models were developed to predict the oil retention amount in suction line. • Double circle model was proposed to describe the interface behavior of stratified-wavy flow and annular flow. • New correlations of interfacial friction factor and void fraction were established. • The flow-pattern based method displayed MAE of 9.35% and captured 87.83% of data within ±20% deviation. • Two models were utilized to evaluate minimum refrigerant mass flux, which guarantee that oil can successfully return back to compressor. Modeling study for predictions of oil retention and critical refrigerant mass flux in compressor suction line was presented in the current work. Three approaches were developed for prediction of oil retention amount in suction line, namely, annular flow model, flow-pattern based method and empirical void fraction model. The annular flow model assumed that annular flow exists as the flow pattern, while the flow-pattern based method described the flow behavior of refrigerant/oil mixture by the flow pattern classifications and double circle model. Based on the proposed models, new correlations of interfacial friction factor and void fraction were established. The experimental data for R32 with coexistence oil PVE68 inside horizontal, vertical and inclined suction lines were used as the foundation and validation of the models. The results showed that all the models display satisfying prediction for oil retention. The flow-pattern based method exhibited the best results, which yielded the mean absolute deviation of 9.35% and captured 87.83% of the data within ±20% error bands. Moreover, two models for prediction of minimum refrigerant mass flux were recommended in order to ensure successful oil return. These models could serve as tools for operation optimization incorporating the lubricant oil effect. [ABSTRACT FROM AUTHOR]

In this article we propose an original approach designed by archaeologists and a computer scientist for knowledge creation in studies of movement. Using case studies, we analyze how researchers have identified, conceptualized, and linked the material traces describing various movement processes in a given region. Then, we explain how we construct ontologies that enable us to explicitly relate material elements, identified in the observed landscape, to the knowledge or theory that explains their role and relationships within the movement process. Combining formal pathway systems, so-called « Path framework systems » and informal movement systems, so-called « Pathway systems », through these case studies, we argue that these systems are not hierarchically integrated, but rather intertwined. We introduce a new heuristic tool, named the "track graph", that records observed material features in a thematically neutral form. The « track graph » can then be employed to reconstruct the trajectories ofjourneys which follow different movement logics. [ABSTRACT FROM AUTHOR]

• Non uniform temperature in tomato crates arranged in a pallet layer was observed. • Simplified thermal and aroma models were developed and linked together. • Statistical analysis on these models showed acceptable Root Mean Square Error. • Aroma losses when temperature < 12 °C and recovers partially when return to ambient. • Product temperature and aroma evolutions in supply chain scenarios were predicted. Convective cooling/heating experiments were carried out using a device representing a half-layer of a pallet with four crates of tomatoes (var. Cauralina, Solanum Lycopersicum). Air and product temperatures were measured at different positions in the crates, which were exposed to several different ambient conditions in order to study the influence of air velocity, warming/cooling regimes, hole opening area and filming. The experimental results show that the product and air temperatures vary with the distance from the air inlet position. Since airflow rate was varied and controlled using fans equipped with electrical power variation, a correlation between the air velocity and the convective heat transfer coefficient was established. A transient state heat transfer model was developed based on a zonal approach, which considers overall thermo-physical properties for each crate. An aroma model was developed based on three hypothetic first order kinetics. The model takes into account the observation reported in several studies that tomato aroma decreases when the product temperature is lower than 12 °C and the aroma is recovered, but only partially, when the product temperature is higher than 12 °C. Finally, the thermal model was linked with the aroma model to predict the product temperature and the aroma evolution in two examples of supply chain scenario from producer cold room to consumption point. These numerical results show that the tomato variety and the product time-temperature history in a supply chain exert a significant influence on the aroma evolution. [ABSTRACT FROM AUTHOR]

This work is concerned with the analysis of physical and chemical parameters and the adsorption capacity of activated coals from cocoa pod shells. These shells were crushed by a Retsch SK100 mill and sieved by a Retsch type sieve. Only particles with a diameter of between 0.5 and 1mm were retained. Pyrolysis was carried out at 450°C in a muffle furnace of the Nabatherm 30-3000°C type. The shells were previously impregnated with orthophosphoric acid in concentrations ranging from 5 to 25%. The results indicate pyrolysis yields of less than 50% for all coals. The ash content varies from 19.4% to 3.2%. These activated coals have good porosity with maximum iodine and methylene blue index values of 1472.09mg/g and 606.55mg/g respectively. These characteristics led to the choice of CA10 and 20 coals for adsorption tests with the Blue 16 and methyl red dyes. The equilibrium time obtained during the adsorption of the two dyes on the two types of activated carbons is 60 min. The adsorption kinetics of two dyes follow the pseudo second order model with correlation coefficients greater than 0.9. [ABSTRACT FROM AUTHOR]

• Four different refrigeration machine models are evaluated. • Implementation of the models in the optimization potential index (OPI) is shown. • Acceptable and adequate baseline values for the OPI scale are proposed. • Performance and optimization potential of refrigeration machines is revealed. • Application of the method is shown on a real field plant as a case study. To investigate and optimize a refrigeration system, the behavior at various operating conditions must be known or determined. The performance and improvement possibilities may then be inferred from measurement data and compared with corresponding performance key figures. These values are typically referred to normal conditions and it is usually unknown which ones represent an adequate operation. However, it is relevant for refrigeration plant operators to have reference values for a large range of operation conditions as a baseline for determining the obtainable improvements. The present work proposes the application of steady-state models of refrigeration machines for increasing the range of applicability of the exergy-based optimization potential index method. Four different modeling approaches are evaluated and discussed: equation-fit, physical lumped parameter, refrigeration cycle and artificial neural network based models. The practical usage of the improved evaluation method is shown for the subsystem refrigeration machine on a real field installation as a case study. With the introduced additional limits for the optimization potential index, the interpretability of the results is increased. The distinction between adequate (technical requirements exceeded), acceptable (technical requirements fulfilled) and inadequate (potential for improvement) operation according to the state of the art in technology is straightforward, which is important in practice. [ABSTRACT FROM AUTHOR]

• A linearized model provides insight into electrocaloric cooling thermodynamic cycles. • Derivations for Brayton, Carnot, and Otto cycles are provided. • Modeling results highlight the importance of efficient charge recovery. • Brayton and Otto cycles can be more efficient than Carnot cycles in practical systems. This paper introduces a linearized model of electrocaloric cooling. The model is derived for electrocaloric Brayton, Carnot, and Otto cycles, and a more practical hybrid constant voltage-charge (HCVC) variation of the Otto cycle. It is then parametrized for a benchmark terpolymer material. Model outputs are used to examine the system performance under each cycle as a function of temperature lift. The impact of electrical charge recovery efficiency on performance is then investigated to provide insight into system optimization requirements. Practical limitations of charge recovery circuits are discussed in the context of heat and work transfer in each cycle leg. Results indicate that electrical charge recovery efficiency greater than 95% is needed to achieve competitive system efficiency and that this is challenging with a Carnot cycle, despite its theoretical optimality. The Brayton and Otto cycles, in contrast, can achieve cooling efficiencies that approach the theoretical maximum. [ABSTRACT FROM AUTHOR]

The numerical geometrical configuration and cooling performances of parallel wire geometry have been investigated in one-dimensional active magnetic regenerator. Based on the actual regenerator, the wires in geometries were primarily arranged in square and triangular array, and worked in cross and parallel flow patterns. Regenerators containing wire bundles with three geometries were evaluated by varying utilization at fixed temperature spans between hot and cold reservoirs. The effects of geometrical parameters on heat transfer performance and friction factor of regenerator were firstly discussed here. Two materials, gadolinium and La(Fe,Mn,Si) 13 H y , have been used for simulating the cooling performance of wire geometry. The numerical results showed that the arrangement of wires did not have influence on the cooling power greatly and the wire geometry could provide a higher coefficient of performance in parallel flow. After optimization, the desirable parallel wire geometry had a porosity of 0.40 and wire diameter of 0.15 mm. When the frequency was 2 Hz and temperature span was 10 K, the maximum cooling power could reach 158.40 W and 100.3 W for Gd and La(Fe,Mn,Si) 13 H y wire geometries, whose coefficients of performance were as high as 13.46 and 14.96 respectively. Comparatively, the cooling powers of commonly used Gd and La(Fe,Mn,Si) 13 H y packed bed were one third lower than those of optimized wire geometriesand the coefficients of performance were lower half. [ABSTRACT FROM AUTHOR]

For territories subject to strong anthropogenic pressures, such as urban peripheries of major cities, modelling and simulating changes is an important issue to understand the effects of today’s actions on the territories of tomorrow. This article aims at modelling the dynamics of land cover and their effects around the protected areas of the northern zone of Libreville, using an approach combining quantification and spatialization of remote sensing data. The paper also proposes a projective analysis of these dynamics for 2020 and 2028. The results show that, between 2000 and 2014, the land cover classes most affected by regressive dynamics were the low-density forest, dense forest and mangrove. These classes were mostly converted to artificial areas. Vegetation formations (forests and mangroves) had the strongest conversion factors between 2000 and 2014, with 57.58% for low-density forest, 21.17% for dense forest and 17.68% for mangrove. The transition probability matrix indicate that the probability of the built environment occupying low-density forests ranges from 33% to 41% for 2020 to 2028, while its probability of colonizing dense forest ranges from 0.72% to 7.76% for the same years. The simulations carried out show that the future of the protected zone will undergo a significant reduction of its forest surfaces, despite some areas of forest regeneration. [ABSTRACT FROM AUTHOR]

Fire disasters are one of the most common technological disasters in Iran. These disasters have killed many people and resulted in significant economic loss. The "Plasco" building fire in 2017 is one example of these catastrophic disasters, when most of Iran was affected by its tragic news. Regarding the increasing number of risk factors for fire disasters, we aimed to study future scenarios for such disasters in the country. The present study is a futuristic study with an exploratory approach that uses an intuitive logic scenario development approach. We used document analysis, semi-structured interviews, and the Delphi technique to identify driving forces and develop scenario stories, and finally those scenario stories were validated. In the document analysis phase, 22 documents were identified and analysed. After collecting information related to documents and analysing ten interviews, 41 of the driving forces were identified. By drawing the scenario matrix, four alternative scenarios for the future of fire disasters were developed. Two dimensions for scenario development were the correct application of fire prevention laws and access to driving technologies. Policymakers can concentrate on these key factors for best planning in the mitigation of fire disasters. In addition, studying scenarios can help managers and officials to better develop strategic plans for disaster risk reduction. [ABSTRACT FROM AUTHOR]

High pressure miniature air compressor plays an irreplaceable role in some areas such as refrigeration and pneumatic ejection in the fighter. But, as a lot of heat is produced during compression, the cooling system consumes relatively more energy and its volume and weight even exceeds the compressor itself. So, how to design cooling system becomes the key factor. A novel self-air-cooling reciprocating compressor (SACRC) is first proposed in this paper, which can continuously cool the compressor through ingenious structural design without any auxiliary equipment. The SACRC's model is established considering of thermal dynamics and heat exchange characteristics of all the units, which regards the spiral groove in the cooling system as a chamber with compressibility and heat exchange. The characteristics of SACRC are studied by comparative simulation and experiment validation with traditional reciprocating compressor (TRC). The research results showed that the volumetric efficiency and temperature characteristics of SACRC are both improved significantly especially at high output pressure and long working time, which is pioneering significance to further improve the miniaturization of high pressure compressor. [ABSTRACT FROM AUTHOR]

• A mathematical method is developed to simulate the processes of an adsorption chiller. • The simulated outlet temperatures are within ± 0.5 °C of experimental data. • The variations of uptake and bed temperature throughout the cycle are investigated. • Optimum mass and heat recovery durations for different operating temperatures are determined. • A nominal mass recovery may be sufficient for low generation temperature lift. A typical commercial two-bed adsorption chiller using silica gel as adsorbent and water as adsorbate is simulated in the current study. Each of the two beds goes through four processes in one cycle, namely, adsorption, mass recovery, heat recovery, and desorption. A transient lumped analytical model is developed, and the governing equations are solved using the MATLAB® platform. The thermophysical properties of the refrigerant are collected from REFPROP®, which is integrated within the MATLAB® codes. The simulation model is validated with the test results of a commercial chiller manufactured by Bry-Air (Asia) Pvt. Ltd. The cooling capacity of the chiller is 40 ton of refrigeration, and in this study, the simulation results are in good agreement with the test results provided by the manufacturer. The simulation model is then utilized in the present investigation to predict the performance of a typical commercial chiller under various working conditions. The recovery times, the temperatures of hot water, cooling water, and chilled water are varied, and their impacts on the cooling capacity and COP of the chiller are analyzed. The optimum recovery durations are reported for different temperatures, and their effects on the bed uptakes are investigated. The model can be used as an effective means to determine the optimal cycle time with necessary recovery durations for a specific cooling load, with a view to providing the maximum efficiency under specified operating conditions. [ABSTRACT FROM AUTHOR]

Sorption compressors are thermally driven, and unlike mechanical compressors, they do not have moving parts, and therefore do not emit vibrations and are highly reliable. There exist different sorption compressor configurations for different operating conditions and various gases. The current research presents a dynamic numerical model of multi-stage sorption compressors, where each compression stage may consist of several sorption cells, which are connected in parallel. The model is based on a single sorption cell model, which determines the fluid pressure and temperature as a function of the cell's operating conditions and design (configuration, dimensions, and materials). The model is suitable for describing sorption cells with various heating and cooling methods, and for any adsorbent-adsorbate pair. An experimental validation of the model is presented, with three experiments at different operating conditions. Then, a numerical investigation of two different sorption cell configurations, and with several compressor structures is demonstrated, to show the capabilities of the model. The main difference between the configurations is their cooling method: one is internally cooled by a heat transfer fluid, and the other is externally cooled through its envelope. The presented model is suitable for developing sorption compressors for different fluids and applications. [ABSTRACT FROM AUTHOR]

Can we understand how plant cell metabolism really works? An integrated large-scale modelling of plant metabolism predictive model would make possible to analyse the impact of disturbances in environmental conditions on cellular functioning and diversity of plant-made molecules of interest. ChloroKB, a Web application initially developed for exploration of Arabidopsis chloroplast metabolic network now covers Arabidopsis mesophyll cell metabolism. Interconnected metabolic maps show subcellular compartments, metabolites, proteins, complexes, reactions, and transport. Data in ChloroKB have been structured to allow for mathematical modelling and will be used as a reference for modelling work dedicated to a particular issue. [ABSTRACT FROM AUTHOR]

Our interest is in the development of modeling activities that link knowledge in various mathematical fields and other scientific disciplines. Looking at mathematics education, research we highlight the benefits and limitations of "problem-solving" and of approaches that involve translation between the real world and mathematics. Science education seldom takes mathematics into account. Its contribution is the conception of an "empirical referent". Using epistemological studies, we highlight examples of modeling situations supported by a plurality of models and an organization of work that allows students to engage with them. To do this we adopt the theoretical framework of connected working spaces. A case study shows how students create linkages between the workspaces and the benefits of the connections on their understanding of concepts at stake. [ABSTRACT FROM AUTHOR]

This paper discusses the interface between schools, museums and other locales of scientific and technical culture. Our goal is to define the terms for a partnership aimed at nurturing science education. After we analyze the literature and research results derived from the areas of "education for," we examine the possibility of utilizing the concepts of "boundary objects" and "islands of rationality" to explain and model the complexity of the crossroads of innovation between formal and non-formal education. [ABSTRACT FROM AUTHOR]

• A new DX-SAHP system with subcooling control is formed by adding two components. • A quasi-dynamic mathematical model of the new DX-SAHP system has been developed. • The simulated results are compared with experimental data of the original system. • The maximum heating COP of the new system occurs with degree of subcooling at 4 K. • The system has better performance with degree of subcooling in range of 2–5 K. As an essential operation parameter of a direct-expansion solar-assisted heat pump (DX-SAHP) system, the degree of subcooling has influence on the thermal performance of the system. Based on the original experimental setup, a throttling valve and a liquid receiver are added at the outlet of the condenser to control degree of subcooling, forming a new system. A quasi-dynamic mathematical model of the new system has been developed to analyze the effect of subcooling on the system performance, and the iterative criterions for the model convergence are degree of superheat and degree of subcooling. The simulation results show that, the heating capacity per unit refrigerant mass is sensitive to the variation of degree of subcooling at the lower degree of subcooling, while the compressor power per unit refrigerant mass is sensitive to that at the higher degree of subcooling. The maximum heating coefficient of performance (COP) of the new system occurs when the degree of subcooling remains constant at 4 K. In the four typical days, the heating COP values of the new system with a constant degree of subcooling of 4 K are 9.13%, 14.35%, 9.42% and 5.73% higher than that of the original system, respectively. Moreover, the parametric study shows that the DX-SAHP system can achieve better performance in term of heating COP by controlling the degree of subcooling in the range of 2–5 K. [ABSTRACT FROM AUTHOR]

• Experimental measurement of VLE data for R1243zf + R1234ze(E) by a static analytical method. • The R1243zf + R1234ze(E) system is a zeotropic system within 283.15 to 323.14 K. • Experimental data show good agreement with the predicted results of PR-MC-vdW and PR-MC-MHV2 models. The environmental performance becomes the critical factor of the selection of refrigerant. 3,3,3-trifluoropropene (R1243zf) and trans-1,3,3,3-tetrafluoropropene (R1234ze(E)) are environmental friendly candidates to replace R134a. Whereas, in the consideration of environmental factor, safety, and energetic efficiency at the same time, none of the pure refrigerants has been proved to be a suitable solution. Mixed refrigerants provide an approach to this problem because the characteristics of refrigerant blends can be optimized for particular applications in the way pure component refrigerant alone cannot be. The purpose of this work is to explore an R1243zf/R1234ze(E) blend which can be possibly used as a long-term alternative to replace hydrofluorocarbons (HFCs) and hydrochlorofluorocarbons (HCFCs). We report the measurements of saturated vapor pressures of R1234ze(E) and R1243zf ranging from 273.17 to 353.13 K, and isothermal vapor-liquid equilibrium of R1243zf + R1234ze(E) systems from 283.15 to 323.14 K. The measurements are performed by static-analytic type apparatus coupled with two electromagnetic capillary samplers (ROLSI®, patent of Armines). The experimental data are correlated by the Peng-Robinson (PR) equation of state (EoS) associated with Mathias-Copeman (MC) alpha function and classical mixing rules. For the comparison of conventional mixing rules and excess free energy (GE) mixing rules models, classic van der Waals one fluid mixing rules and modified Huron-Vidal second-order (MHV2) mixing rules are employed respectively to the correlation of experimental VLE data. The modeling results are in good agreement with the measured data, while the PRMC-MHV2 model exhibits better performance in VLE prediction. [ABSTRACT FROM AUTHOR]

• A parametric convective heat transfer term is used to assess t span & cooling power. • Four major magnetocaloric materials are screened. • Optimal fluid velocity depends on the magnetic transition temperature. A 2-dimensional numerical model of a room temperature operating Active Magnetic Regenerator (AMR) that comprises of a regenerator, hot and cold heat exchangers, heat transfer fluid is developed. The regenerator is made of a magnetocaloric material (MCM) which heats up upon applying a magnetic field, H, and cools down when the field is removed; thus, making it the most essential part of an AMR. The model takes experimentally measured ∆T ad (H,T) and the C p (H,T) data as input and provides quantitative performance metrics of the magnetic cooling system, such as ∆T span and the cooling load, as output. With this model, it is possible to assess a wide range of MCMs in an AMR. 4 different MCMs were investigated using this model in terms of their ∆T span and the cooling loads—LaFe 10.96 Co 0.97 Si 1.07 , MnFeP (1-x) As (x) and AlFe 2 B 2 and Gd. During the screening of MCMs, all the important operating conditions of the device were fixed such as the fluid flow rate, ambient temperature, cycle duration, magnetic field strength. Our results indicate that Gd exhibits the maximum ∆T span with respectable cooling load, while AlFe 2 B 2 generates the lowest ∆T span. Even though LaFeCoSi compound did not perform as well as Gd, it could be the MCM choice for the realization of magnetic refrigeration on a global scale due to its much lower cost. [ABSTRACT FROM AUTHOR]

A recurring problem in longitudinal research on human activity is the lack of articulation between qualitative analytical models and quantitative synthetic models of the dynamic evolution. This absence creates difficulties in justifying the choices of analysis and synthesis and prevents a deductive approach to longitudinal dynamics. Within the framework of a 3-year longitudinal empirical and technological research on appropriation, this paper discusses the conditions of production and the usefulness of a quantitative synthetic model of the longitudinal complexity of individual activity, in conjunction with a qualitative analytical method. More than the mobilization of a single, pre-data model, the modeling work involves an active articulation between analytical model-methods (classical in activity analysis) and synthetic model-methods. We discuss the contributions and limits of this work with respect to activity analysis in Frenchlanguage ergonomics and the complexity sciences more often mobilized in human factors. [ABSTRACT FROM AUTHOR]

• Generalized method presented to predict heat transfer rate and refrigerant temperature of transcritical gas coolers. • Based on the moving-boundary approach to separate supercritical and supercritical liquid regions. • New method shows higher accuracy in the predictions with extremely low computational efforts. • New model presents improved predictions for micro-channel type gas coolers compared to fin-and tube ones. • Source code of the method is provided in Python programming language as an appendix. This paper presents the development of a CO 2 gas cooler model using the moving-boundary (MB) method. The model aims to separate the gas cooler into two regions, supercritical and supercritical liquid, to predict the steady-state thermal heat transfer rate for air-type CO 2 heat exchanger. The model uses the latest correlations for refrigerant and air-side heat transfer coefficients and pressure drops. The experimental results of fin-and-tube type and micro-channel type gas coolers were used for model validation. The mean absolute error (MAE) of the gas cooler heating capacity predictions was approximately 4%, while the predictions of the outlet temperature of the refrigerant side were within ± 3 K. The present MB model also showed an improved computational time of up to 10 times faster compared to a discretized model, which can reduce the overall computational effort in the simulation of detailed transcritical cycle model. [ABSTRACT FROM AUTHOR]

One recurring problem in longitudinal research on human activity is the lack of articulation between qualitative analytical models and quantitative synthetic models of the dynamic evolution. This absence makes it difficult to justify analysis and synthesis choices and prevents a deductive approach to longitudinal dynamics. Within the framework of a 3-year longitudinal empirical and technological research on appropriation, this article discusses the conditions of production and the usefulness of a quantitative synthetic model of the longitudinal complexity of individual activity, in conjunction with a qualitative analytical method. More than the mobilization of a single, pre-data model, the modelling work involves an active articulation between analytical model-methods (classical in activity analysis) and synthetic model-methods. This linkage offers prospects for improving longitudinal studies centred on human activity and provides useful visual support for design projects. We discuss the contributions and limits of this work with respect to activity analysis in French-language ergonomics and the complexity sciences most often mobilized in human factors. [ABSTRACT FROM AUTHOR]

Over the course of this study, we analyze the problem-solving schemes proposed for two sequences of estimation problems. In the first sequence, the problems ask for estimates directly, whereas in the second, each estimate is asked for based on a contextualized situation. The first objective is to identify, statistically, if there is a link between the problem-solving strategy and the characteristics of the context within which the estimation task occurs. The second objective is to analyze the impact that the structure of the word problem has on students' success. To these ends, we analyzed the written answers of N=224 and N=87 university students who are in teacher training. The results show that there is a significant relationship (independent of the sequence) between the variables of the problems based on context and the proposed problem-solving strategy. Moreover, we observe that modifying the structure of the word problem makes the development of a problem-solving scheme more difficult only when the required estimate is not asked for directly. The results allow us to make conclusions about the potential use of these sequences to promote flexibility in approaches to problem solving. [ABSTRACT FROM AUTHOR]

Many researchers accept that working on covariation helps to construct the notion of functions and promotes comprehension of concepts in differential calculus. However, no study has yet defined the characteristics of the situations that allow this work to take place. We therefore propose a reflection on these characteristics with the assistance of applied covariational reasoning. Based on the Covariation Framework generated by Carlson and her colleagues (Carlson et al., 2001, 2002, 2003, 2015), we describe 13 units of reasoning, a priori, that are applied during functional modeling situations in real learning contexts. Through the creation of four situations and an analysis of data collected during a study among students aged 15 to 18 years, we have refined the descriptions of the units of reasoning and identified the actual reasoning skills used by students in each situation. In this article, we present some of the results—particularly how these units of reasoning manifest in the students' descriptions of the behaviours of quantities and their growth. We also show the effects that a situation's written and induced forms of questioning have on the dynamic of reasoning. [ABSTRACT FROM AUTHOR]

Radiomics are a set of methods used to leverage medical imaging and extract quantitative features that can characterize a patient's phenotype. All modalities can be used with several different software packages. Specific informatics methods can then be used to create meaningful predictive models. In this review, we will explain the major steps of a radiomics analysis pipeline and then present the studies published in the context of radiation therapy. A literature review was performed on Medline using the search engine PubMed. The search strategy included the search terms "radiotherapy", "radiation oncology" and "radiomics". The search was conducted in July 2019 and reference lists of selected articles were hand searched for relevance to this review. A typical radiomics workflow always includes five steps: imaging and segmenting, data curation and preparation, feature extraction, exploration and selection and finally modeling. In radiation oncology, radiomics studies have been published to explore different clinical outcome in lung (n = 5), head and neck (n = 5), esophageal (n = 3), rectal (n = 3), pancreatic (n = 2) cancer and brain metastases (n = 2). The quality of these retrospective studies is heterogeneous and their results have not been translated to the clinic. Radiomics has a great potential to predict clinical outcome and better personalize treatment. But the field is still young and constantly evolving. Improvement in bias reduction techniques and multicenter studies will hopefully allow more robust and generalizable models. [ABSTRACT FROM AUTHOR]

• New VLE data for 5 binary mixtures of hydrocarbons, HFCs and HFOs. • VLE data measured by means of a static analytic method. • VLE data correlated with a Peng-Robinson EoS with Mathias–Copeman α function and classical mixing rules. • Both temperature dependent and independent kij were used. Performances of systems using refrigerants are highly dependent on the selection of the working fluids. In order to guide this choice, the thermophysical properties of these fluids need to be correctly correlated. Experimental data are required for models to work; The knowledge of thermophysical properties of working fluids is required for designing ORC and High Pump (HP) systems. Isothermal vapor-liquid equilibrium (VLE) data for the HFO-1336mzz(E) (trans-1,1,1,4,4,4-hexafluoro-2-butene) binary mixture with HFC-290 (Propane), HFC-134a (1,1,1,2-tetrafluoroethane), HFC-152a (1,1-difluoroethane), HFC-227ea (1,1,1,2,3,3,3-heptafluoropropane) and HFO-1234ze(E) (trans-1,3,3,3-tetrafluoropropene) were measured at 313 K, 333 K and 353 K. The experimental technique used is based on static analytic methods. All of the data (P-x-y) were well correlated with the Peng-Robinson equation of state, associated with a Mathias-Copeman alpha function and classical mixing rules. The results of such modeling are in good agreement with the measured data. [ABSTRACT FROM AUTHOR]

An improved internal structure is proposed to improve the distribution of cooling capacity in refrigerated container. Firstly, a computational fluid dynamics model was established and the fruit stacks was simplified to be porous medium. The flow resistance coefficient was obtained by combining theory and numerical simulation and then verified. Secondly, three baffles were added to reduce the loss of cold airflow by blocking the airflow through air-gaps. The velocity and temperature of the previous refrigerated container and the improved refrigerated container were obtained and compared. The cold airflow distribution in the improved refrigerated container is more uniform. The improvement of vertical velocity in all stacks is in the range of 5.24% – 425.04%. The cooling performance of the two refrigerated containers were also obtained. The variation of temperature distribution is within ±1 °C and the cooling time is also reduced by at least 22.9% in the improved refrigerated container. Finally, the proposed structure showed good applicability for different fruits and vegetables. For all produce tested, the decrease ratio of temperature rise in the improved refrigerated container relative to the previous refrigerated container ranges from 34.0% to 59.5%. [ABSTRACT FROM AUTHOR]

• Adsorption beds made by finned tube heat exchangers packed by silica-gel grains. • Heat and mass recovery cycles were combined with the system. • A lumped analysis for coupled heat and mass transfer model is carried out. • The effect of various fin configurations on the chiller performance is investigated. Adsorption refrigeration systems are commercially matured due to the need of decreasing electrical power consumption and usage of non-environmental refrigerants, which are the main problems of the conventional refrigeration systems. This paper presents an investigation on the performance of small-scale two-bed adsorption chiller combined with heat and mass recovery cycles with the aid of a lumped analytical simulation technique. This model is applied to analyze the effect of fin design parameters on the heat transfer inside the bed and system performance. The working pair used in the simulations is RD silica gel–water. Defining a base-case for the fin design parameters, fin thickness, fin radius, and fin spacing are changed and the performances of four fin configurations are demonstrated. Decreasing the fin spacing enhances the heat transfer significantly. For optimum operation condition, specific cooling capacity is improved by an average value up to 147.6% by decreasing fin spacing from 4 mm to 2 mm, while increasing the fin radius decreases temperatures of the adsorbent. Specific cooling capacity is improved by an average value up to 44% by decreasing fin radius from 16 mm to 8 mm. The fin thickness has a minor effect on heat transfer in the bed. [ABSTRACT FROM AUTHOR]