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Litchi fruit is rich in water and nutritional value. Machine picking can greatly reduce production costs. But if mechanical damage occurs during picking, it will seriously affect subsequent storage and transportation. In order to ...
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Litchi fruit is rich in water and nutritional value. Machine picking can greatly reduce production costs. But if mechanical damage occurs during picking, it will seriously affect subsequent storage and transportation. In order to reduce the mechanical damage caused by excessive clamping force of the end effector on litchi, this study used the finite element model to analyze the mechanical damage caused by different clamping methods on the pericarp, sarcocarp and putamen of litchi under the basic clamping conditions. The results showed that the effect of clamping the fruit below the waist by double finger lifting was excellent. The maximum deformation of litchi was 42.06um, the average equivalent elastic strain was 3.90×10~4 and the maximum equivalent stress was 62857 Pa. This method effectively reduced the maximum stress and average strain in the process of grasping and reduced the mechanical damage caused by the end effector to the pericarp and sarcocarp. At the same time, it can provide some reference for the similar characteristics of fresh fruit picking, sorting, transportation and packaging.
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Different methods for free-form surface deformation have been developed in the last years to overcome difficulties in direct manipulation of surfaces. Even if these approaches are real improvements in the design workflow, they are...
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Different methods for free-form surface deformation have been developed in the last years to overcome difficulties in direct manipulation of surfaces. Even if these approaches are real improvements in the design workflow, they are still far from the stylists' requirements whose main target is the aesthetic shape. Feature-based approaches have been introduced to provide users with more intuitive tools improving interactivity without reducing their creativity. To couple the advantages of both approaches here we propose a hierarchical free-form features classification built on top of our surface deformation tool, where so-called Basic Shape Features and High Level Features form the two main classes on which basis a feature taxonomy is defined according to morphological and topological criteria.
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The selection of optimal positive end-expiratory pressure (PEEP) levels during ventilation therapy of patients with ARDS (acute respiratory distress syndrome) remains a problem for clinicians. A particular mooted strategy states t...
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The selection of optimal positive end-expiratory pressure (PEEP) levels during ventilation therapy of patients with ARDS (acute respiratory distress syndrome) remains a problem for clinicians. A particular mooted strategy states that minimizing the energy transferred to the lung during mechanical ventilation could potentially be used to determine the optimal, patient-specific PEEP levels. The dynamic elastance model of pulmonary mechanics could potentially be used to minimize the energy by localization of the patients' minimum dynamic elastance range. The sensitivity of the dynamic elastance model to variance in the airway resistance was analyzed. Subsequently, the airway resistance was determined using two alternate identification methods and was compared to the constant resistance obtained using the dynamic elastance model. Both identification methods showed similar decreasing trends of the resistance during inspiration. This declining trend is an apparent exponential decrease. Results showed that the constant airway resistance, presumed by the dynamic elastance model, has to be rechecked and investigated.
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This paper presents the experimental results of high-density PUR foam plastics for tensile and compressive loading at different strain-rates and temperatures. The elastic properties and yield stress of foam plastics is addressed a...
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This paper presents the experimental results of high-density PUR foam plastics for tensile and compressive loading at different strain-rates and temperatures. The elastic properties and yield stress of foam plastics is addressed at the same time. Theoretical formulae for moduli and strength of foam plastics are proposed, which agree well with the available experimental data.
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This paper presents the experimental results of high-density PUR foam plastics for tensile and compressive loading at different strain-rates and temperatures. The elastic properties and yield stress of foam plastics is addressed a...
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This paper presents the experimental results of high-density PUR foam plastics for tensile and compressive loading at different strain-rates and temperatures. The elastic properties and yield stress of foam plastics is addressed at the same time. Theoretical formulae for moduli and strength of foam plastics are proposed, which agree well with the available experimental data.
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This paper presents a study on the direct and inverse models for a class of hybrid parallel mechanisms with three independent chains. The first symbol, J in the structural formula 3(JRS), has the significance of a general mechanic...
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This paper presents a study on the direct and inverse models for a class of hybrid parallel mechanisms with three independent chains. The first symbol, J in the structural formula 3(JRS), has the significance of a general mechanical Joint with a certain number of freedom degrees. The author presents an analysis of the general case and then he develops two particular cases of this mechanism class. There are also presented numerical results obtained by a computer programme write by the author.
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This paper presents a study on the direct and inverse models for a class of hybrid parallel mechanisms with three independent chains. The first symbol, J in the structural formula 3(JRS), has the significance of a general mechanic...
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This paper presents a study on the direct and inverse models for a class of hybrid parallel mechanisms with three independent chains. The first symbol, J in the structural formula 3(JRS), has the significance of a general mechanical Joint with a certain number of freedom degrees. The author presents an analysis of the general case and then he develops two particular cases of this mechanism class. There are also presented numerical results obtained by a computer programme write by the author.
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Considering the concept as a mental mechanism, I propose a simple model of concept functionality. From this model, follow some criteria of the concept construction conditions. Using this model, I analyze different didactic possibi...
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Considering the concept as a mental mechanism, I propose a simple model of concept functionality. From this model, follow some criteria of the concept construction conditions. Using this model, I analyze different didactic possibilities of the development of the negative numbers understanding in school students. Then, I propose a physical science context that nicely meets discussed criteria. Some preliminary testing indicates that this context could possibly be used to start the negative numbers concept development as early as in primary school.
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Recent studies have documented a number of health benefitsassociated with the consumption of citrus, largely due to thenatural phytochemicals found in these fruits, such asflavonoids, limonoids, furocoumarins, and pectins. Interes...
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Recent studies have documented a number of health benefitsassociated with the consumption of citrus, largely due to thenatural phytochemicals found in these fruits, such asflavonoids, limonoids, furocoumarins, and pectins. Interest inthe chemopreventive properties of phytochemicals has led tomore detailed studies to determine the mechanisms of actionof these compounds in animal models and humans, to optimizethe levels of the phytochemicals in citrus based on agriculturaland processing factors, and to develop better analyticalmethods for identifying and quantifying phytochemicals incomplex mixtures. This chapter provides an overview of themany aspects of citrus and its health benefits that will bedescribed in more detail in chapters throughout this book.
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During mechanical ventilation(MV)of respiratory failure patients,clinicians require real time patient-specific lung condition to set MV treatment.Application of mathematical models to determine patient-specific condition in settin...
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During mechanical ventilation(MV)of respiratory failure patients,clinicians require real time patient-specific lung condition to set MV treatment.Application of mathematical models to determine patient-specific condition in setting MV is increasingly sought after amongst clinicians.However,when the patient is breathing spontaneously during controlled ventilation modes,estimation of respiratory mechanics becomes erroneous due to presence of patient inspiratory effort.Thus,there is a need to determine patient's respiratory mechanics during the presence of these efforts.This study presents a mathematical expression built on the single compartment model to determine patient respiratory mechanics.The model uses basis function and takes patient inspiratory effort into account.Inspiratory efforts of 1125 cases were simulated to determine the model performance and its stability.The study revealed that the model was capable of estimating asynchronous airway pressure.The model can be potentially useful to simulate any nonlinear airway pressure waveform with spontaneous effort.
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