Fine structure and elemental composition of envelopes of 10 taxa of Trachelomonas and Strombomonas from natural freshwater bodies in China were studied and phylogeny of both genera were discussed. The results indicate...Fine structure and elemental composition of envelopes of 10 taxa of Trachelomonas and Strombomonas from natural freshwater bodies in China were studied and phylogeny of both genera were discussed. The results indicate that iron (Fe) and silicon (Si) are the primary mineral elements of the envelopes. Composition of mineral elements was uncorrelated with envelope color, however, it was highly correlated with the microarchitecture of the envelopes. Content of Si was higher than that of Fe in all species of Strombomonas and some species of Trachelomonas with rough surface. In most species of Trachelomonas, especially those with dense and smoothy surface, content of Fe was higher than that of Si. Based on the above results, we propose to assign those species of Strombomonas into Trachelomonas and consider them as a group of the latter. These species were the most primitive among the group with envelopes in Euglenaceae.展开更多
As in homology, the notion of injectivity is introduced in the category whose objects are Hilbert C * module over a C * algebra and whose morphism are bounded module operators. The definition of injective envelope...As in homology, the notion of injectivity is introduced in the category whose objects are Hilbert C * module over a C * algebra and whose morphism are bounded module operators. The definition of injective envelopes of an extension of a Hilbert C * modules over a C * algebra is introduced, and is characterized in terms of the injectivity and essence. It is shown that every Hilbert C * module has a unique (up to H isometrics) injective envelope if it exists. It is also shown that an extension of a Hilbert C * module is an injective envelope if and only if it is an injective and essential extension. Moreover, every Hilbert C * module over a W * algebra has a unique (up to H isometrics) injective envelope and the injective envelope of a Hilbert C * module H is maximal essential extension of H .展开更多
The integration of building with solar collector was studied. The theoretical model of integration of building envelopes and flat plate solar collectors was set up and the thermal performance of integration was studie...The integration of building with solar collector was studied. The theoretical model of integration of building envelopes and flat plate solar collectors was set up and the thermal performance of integration was studied in winter and summer,and compared to envelopes without solar collectors. The results show that the solar collection efficiency is raised in the integration of building envelopes and solar collectors with the air layer doors closed. This is true whether in winter or summer. The increment is higher as the inlet water temperature increases or the ambient temperature is low. In winter,the heat loss is significantly reduced through integration of the building envelopes and solar collectors with the closed air layer doors. The integration with the open air layer door is worse than that without collectors. In summer,the heat gains of the integration of envelopes and solar collectors are more obviously reduced than envelopes without collectors,the integration with the open air layer door is a little better than the closed one,but the difference is very small.展开更多
In order to better assess the performance of wireless communication systems,it is desirable to produce multiple Rayleigh fading envelopes with specified correlations.In this paper,we analyze theoretically a procedure ...In order to better assess the performance of wireless communication systems,it is desirable to produce multiple Rayleigh fading envelopes with specified correlations.In this paper,we analyze theoretically a procedure which generates correlated Gaussian random variables from independent Gaussian random variables and give a physical explanation for the limitation of this procedure.Then,based on some uncorrelated Rayleigh fading envelopes,a simple but efficient procedure for generating an arbitrary number of cross-correlated Rayleigh fading envelopes is proposed.Simulation results and computational complexity analysis are presented,which show that the proposed method has some advantages,such as high accuracy,low computational complexity and easy implementation,over the conventional simulation method.展开更多
The innovation of building envelopes is densely characterized, in the new design process, by new products of the building industry and intelligent robotic systems, making them efficient and dynamic in an eco-efficient...The innovation of building envelopes is densely characterized, in the new design process, by new products of the building industry and intelligent robotic systems, making them efficient and dynamic in an eco-efficient environmental context and spatial flexibility. The goal is that of energy efficiency and environmental sustainability that invest above all the building production sector, pushing towards a circular economy with the use of clean energy resources and new artificial intelligence systems. The intelligence is highlighted through the optimization of the performance of new lightweight envelopes, in the technological design and the new building process, through Lean planning and Lean construction, Mass customization, with application of criteria, methods and tools. So there are innovative technological solutions, for environmental comfort and energy saving, and typological solutions with high performance level, with the use of innovative, adaptive, advanced, light materials with nanoproducts, intelligent IT systems, etc. We highlight the effectiveness of design with natural passive use of renewable energy and energy efficiency of the envelope as “skin” and relative increase in performance levels, in the interaction with the internal environment and natural dynamic flows and in the conversion of thermal and electrical energy. The methodologies are aimed at the application of digital technologies and soft robotic systems for the management and quality of services with technological and constructive solutions for dynamic interactive envelope and intelligent systems of double or triple skin, curtain walls, etc. The challenge is new design models of dynamic enclosures, on criteria and methods that guide the new rules on energy efficiency in buildings, for environmental sustainability and housing quality with the integration of soft robots.展开更多
Building envelopes include facades and roof, which have the most interaction and exchange with outside and natural environment. In the future, meeting buildings various complicated needs with new technological advance...Building envelopes include facades and roof, which have the most interaction and exchange with outside and natural environment. In the future, meeting buildings various complicated needs with new technological advances necessitates a change and evolution in building envelopes. Controlling the energy consumption of the buildings is mostly through controlling the energy performance of the building envelopes. New technologies lead to the intelligent facades and envelopes. The envelope can be designed to be a part of the whole building＇s metabolism （energy production, storage and consumption） and morphology. The envelope would be a controlled part of the building which is managed through the central control system of the building, which connects it to other parts. It caused building envelope design to be changed fundamentally, so that there is a need to interact with engineering disciplines including computer engineering, mechanical engineering, material engineering and so on. All of these caused building envelope to get closer to biological and living systems. The physical restrictions which affect buildings system and living systems are the same. So they cause the same forces to shape the structure and form of the systems and the same rules to interact with the environment. The restrictions of material and energy resources caused living systems to be energy efficient and consuming less material. But the most important difference between living systems and building systems is in maximum use of different resources. As living systems use information maximally, the building system technology is based on using maximum energy. Now, there are many reasons and restrictions that building envelopes cannot act like living systems. But technological developments and contributing more disciplines in design and construction of building envelopes caused the future way of these envelopes get close to living systems for their energy efficiency. Some of living systems characteristics which the future building envelopes would have partially or benefit for the design process or construction are self-organization, evolution principles, hierarchical levels, processing energy, reaction to environmental stimuli and self-adjustment. Self-organization is achieved in some design software and in building material production for creating formal patterns. Evolution principles provide infrastructure for soft wares for optimization purposes and form creation. Hierarchical levels refer to giving hierarchical structure to the building envelopes through layering and designing different scales. Processing energy （metabolism） would be achieved through photovoltaic and solar collectors to produce energy and in passive systems for energy storage and distribution. Controlling solar radiation absorption and transmittance would help energy transfer from outside to building and vice versa. Reaction to environmental stimuli which is one of the most important characteristics of future building envelopes would use different types of active and passive sensors to create envelope mechanical reactions through material properties or collect data for processing in the control center to determine the right reaction. The reaction would be through different strategies such as changing properties and moving. Reaction could be passive or active. Self-adjustment can be achieved by control systems and processing units. All of these mean intelligent envelopes are essential parts of future buildings. Though it is now started with new design soft wares based on biological principles to optimize different parameters affecting the envelope function or to create the most efficient form.展开更多
For plane singly-connected domains with insulating boundary and four point-sized contacts, C<sub>0</sub> …C<sub>3</sub>, van der Pauw derived a famous equation relating the two trans-...For plane singly-connected domains with insulating boundary and four point-sized contacts, C<sub>0</sub> …C<sub>3</sub>, van der Pauw derived a famous equation relating the two trans-resistances R<sub>01,23</sub>, R<sub>12,30</sub> with the sheet resistance without any other parameters. If the domain has one hole van der Pauw’s equation becomes an inequality with upper and lower bounds, the envelopes. This was conjectured by Szymański et al. in 2013, and only recently it was proven by Miyoshi et al. with elaborate mathematical tools. The present article gives new proofs closer to physical intuition and partly with simpler mathematics. It relies heavily on conformal transformation and it expresses for the first time the trans-resistances and the lower envelope in terms of Jacobi functions, elliptic integrals, and the modular lambda elliptic function. New simple formulae for the asymptotic limit of a very large hole are also given.展开更多
Damage on surfaces often compromises the efficiency of some types of energy production, the safety and reliability of components, and ultimately increases costs. The environment can degrade the structural integrity of...Damage on surfaces often compromises the efficiency of some types of energy production, the safety and reliability of components, and ultimately increases costs. The environment can degrade the structural integrity of surfaces in service by the accumulation of large numbers of small destructive events, which based on the Central Limit Theorem leads to a Gaussian distribution of pit depth. In order to develop safety envelopes relating fracture loci with topological parameters of a brittle material, scatter plots were obtained and analyzed. Starting with an engineering surface, after 6 to 9 micrometers of average degradation depth, safety envelopes could be developed using average roughness and two other proposed parameters. Interestingly, maximum pit depth showed very low correlation with the location of fracture, at the early stage of degradation studied. This is attributed to relaxation of stress concentration at a given pit location due to the assuaging effect caused by neighboring pits. Additionally, energy at fracture was obtained, and a maximum relaxation region was observed. Analytical and experimental study of this region, as well as ductility effects are currently under research.展开更多
Helical anchor is a kind of novel foundation for floating offshore wind turbines,which should be subjected to combined tensile loading caused by wind,wave and current.However,the research about the capacity of helical...Helical anchor is a kind of novel foundation for floating offshore wind turbines,which should be subjected to combined tensile loading caused by wind,wave and current.However,the research about the capacity of helical anchor was mainly examined under uniaxial loading and scarcely explored under combined loading.In this study,three-dimensional finite element limit analysis is adopted to assess the bearing capacities of single-plate rigid helical anchors with different ratios of helix to shaft diameter,D_(H)/D_(S) and embedment ratios L/D_(S).Result shows that the vertical,horizontal and moment bearing capacities increase with increasing D_(H)/D_(S) and L/D_(S).The normalized V-H failure envelopes expands with increasing L/D_(S),while the normalized V-M failure envelopes tend to contract with the increase of D_(H)/D_(S).With increasing D_(H)/D_(S) or decreasing L/D_(S),the normalized H-M failure envelopes expand when the horizontal and moment loading act in the same direction and contract when they act in the opposite direction.The effect of D_(H)/D_(S) and L/D_(S) on the shape of H-M failure envelope become insignificant when L/D_(S)≥4.A series of failure mechanisms under different loading conditions were observed and can be used to explain the trend.Besides,a series of approximate expressions were proposed to fit the uniaxial bearing capacities and the failure envelopes.展开更多
The frequency domain analysis of systems is an important topic in control theory. Powerful graphical tools exist in classic control, such as the Nyquist plot, Bode plots, and Nichols chart. These methods have been wid...The frequency domain analysis of systems is an important topic in control theory. Powerful graphical tools exist in classic control, such as the Nyquist plot, Bode plots, and Nichols chart. These methods have been widely used to evaluate the frequency domain behavior of system. A literature survey shows that various approaches are available for the computation of the frequency response of control systems under different types of parametric dependencies, such as affine, multi-linear, polynomial, etc. However, there is a lack of tools in the literature to construct the Bode envelopes for the general nonlinear type of parametric dependencies. In this paper, we address the problem of computation of the envelope of Bode frequency response of a non-rational transfer function with nonlinear parametric uncertainties varying over a box. We propose two techniques to compute the Bode envelopes：first, based on the natural interval extensions （NIE） combined with uniform subdivision and second, based on the existing Taylor model combined with subdivision strategy. We also propose the algorithms to further speed up both methods through extrapolation techniques.展开更多
The integral of the pulse self-demodulation in acoustic parametric array can be calculated in light of the Fourier convolution theorem.Instead of a rectangular pulse with two discontinuous edges,two kinds of primary e...The integral of the pulse self-demodulation in acoustic parametric array can be calculated in light of the Fourier convolution theorem.Instead of a rectangular pulse with two discontinuous edges,two kinds of primary envelopes are used,the waveforms and their spectra are investigated.An optimal ratio of the primary duration has been found theoretically.Experimental results support this theory.展开更多
BACKGROUND Cardiovascular implantable electronic devices(CIEDs)are implanted in an increasing number of patients each year,which has led to an increase in the risk of CIED infection.Antibacterial CIED envelopes locall...BACKGROUND Cardiovascular implantable electronic devices(CIEDs)are implanted in an increasing number of patients each year,which has led to an increase in the risk of CIED infection.Antibacterial CIED envelopes locally deliver antibiotics to the implant site over a short-term period and have been shown to reduce the risk of implant site infection.These envelopes are derived from either biologic or nonbiologic materials.There is a paucity of data examining patient risk profiles and outcomes from using these envelope materials in the clinical setting and comparing these results to patients receiving no envelope with their CIED implantation.AIM To evaluate risk profiles and outcomes of patients who underwent CIED procedures with an antibacterial envelope or no envelope.METHODS After obtaining Internal Review Board approval,the records of consecutive patients who underwent a CIED implantation procedure by a single physician between March 2017 and December 2019 were retrospectively collected from our hospital.A total of 248 patients within this period were identified and reviewed through 12 mo of follow up.The CIED procedures used either no envelope(n=57),a biologic envelope(CanGaroo®,Aziyo Biologics)that was pre-hydrated by the physician with vancomycin and gentamicin(n=89),or a non-biologic envelope(Tyrx^(TM),Medtronic)that was coated with a resorbable polymer containing the drug substances rifampin and minocycline by the manufacturer(n=102).Patient selection for receiving either no envelope or an envelope(and which envelope to use)was determined by the treating physician.Statistical analyses were performed between the 3 groups(CanGaroo,Tyrx,and no envelope),and also between the No Envelope and Any Envelope groups by an independent,experienced biostatistician.RESULTS On average,patients who received any envelope(biologic or non-biologic)were younger(70.7±14.0 vs 74.9±10.6,P=0.017),had a greater number of infection risk factors(81.2%vs 49.1%,P<0.001),received more high-powered devices(37.2%vs 5.8%,P=0.004),and were undergoing more reoperative procedures(47.1%vs 0.0%,P<0.001)than patients who received no envelope.Between the two envelopes,biologic envelopes tended to be used more often in higher risk patients(84.3%vs 78.4%)and reoperative procedures(62.9%vs 33.3%)than non-biologic envelopes.The rate of CIED implant site pocket infection was low(any envelope 0.5%vs no envelope 0.0%)and was statistically equivalent between the two envelope groups.Other reported adverse events(lead dislodgement,lead or pocket revision,device migration or erosion,twiddler’s syndrome,and erythema/fever)were low and statistically equivalent between groups(biologic 2.2%,non-biologic 3.9%,no envelope 1.8%).CONCLUSION CIED infection rates for biologic and non-biologic antibacterial envelopes are similar.Antibacterial envelopes may benefit patients who are higher risk for infection,however additional studies are warranted to confirm this.展开更多
In this paper, for a sustainable building in a Mediterranean climate areas, the relation between envelope and energy is discussed. The relation between envelopes and energy has been considered in all the phases of the...In this paper, for a sustainable building in a Mediterranean climate areas, the relation between envelope and energy is discussed. The relation between envelopes and energy has been considered in all the phases of the life building （construction phase and during operation）. This has been made through global assessment of massive envelopes （with or without insulation） realized with blocks of different materials： natural stone, concrete and brick. For these types of envelope the thermal comfort of the rooms, the energy requirement for cooling and heating, economic and environmental aspects （costs and embodied energy） in the life cycle of the building have been studied.展开更多
It is now recognized that many geomaterials have nonlinear failure envelopes. This non-linearity is most marked at lower stress levels, the failure envelope being of quasi-parabolic shape. It is not easy to calibrate ...It is now recognized that many geomaterials have nonlinear failure envelopes. This non-linearity is most marked at lower stress levels, the failure envelope being of quasi-parabolic shape. It is not easy to calibrate these nonlinear failure envelopes from triaxial test data. Currently only the power-type failure envelope has been studied with an established formal procedure for its determination from triaxial test data. In this paper, a simplified procedure is evolved for the development of four different types of nonlinear envelopes. These are of invaluable assistance in the evaluation of true factors of safety in problems of slope stability and correct computation of lateral earth pressure and bearing capacity. The use of the Mohr-Coulomb failure envelopes leads to an overestimation of the factors of safety and other geotechnical quantities.展开更多
Two independent barrier envelopes are the usual requirement used in most well operations to avoid catastrophic accidents.These are classified as primary-concerning preventing the occurrence of a kick,and secondary-con...Two independent barrier envelopes are the usual requirement used in most well operations to avoid catastrophic accidents.These are classified as primary-concerning preventing the occurrence of a kick,and secondary-concerning controlling the kick to avoid a blowout.Barrier envelopes consist of barrier elements,thus verifying the quality of these elements is fundamental.Barrier elements may be either redundant or mandatory,and these relationships are what constitute the barrier envelopes.In this work,we present a methodology to evaluate well safety by identifying existing barrier elements and barrier envelopes and mapping their relationships through the usage of graphs technique.This technique explicitly states the relationship between barriers and between them and envelopes.It enables a simpler visualization for well designers and allows the development of computer programs to control the safety and integrity of wells,both in the design phase and during drilling.12 graphs are provided for a 4-phase well(conductor,surface,production,and drill-in),considering both the primary and secondary enve-lopes.Reasoning for constructing each graph is thoroughly provided.If these graphs are used,reliability values can then be assigned to each barrier element,which results in the reliability of entire barrier envelopes.This can be further extended to analyze the safety of each operation by applying the system to operational sequences and even comparing well designs.展开更多
Thermally activated building envelopes(TABEs)are multifunctional component that combines structural and energy properties.Based on re-examining the heat charging processes,an arc-shaped metal-fin-enhanced TABE(Arc-fin...Thermally activated building envelopes(TABEs)are multifunctional component that combines structural and energy properties.Based on re-examining the heat charging processes,an arc-shaped metal-fin-enhanced TABE(Arc-finTABE)with directional heat charging features is proposed to optimize the thermal barrier formation process.A comprehensive parameterized analysis is conducted based on a validated mathematical model to explore the influence of 5 fin-structure design parameters and the static insulation thickness.Results verified that the directional charging strengthening fins can improve transient thermal performances of Arc-finATBE and enlarge horizontal and vertical sizes of the thermal energy accumulation area surrounding the pipeline,while the maximum growth in extra heat loss is less than 3.17%.From the perspective of promoting heat injection into expected areas,the straight main fin configurations with the angle of main fins of 30°,shank length ratio of 0.4 and no leftward mounted fins are preferred in load-reduction mode,while the angle of main fins of 150°,shank length ratio of 0.8 and multiple fin designs,especially with one of the main fins horizontally toward the indoor side,are more favorable in auxiliary-heating mode.Besides,it is recommended to add one arc-shaped branch fin to each main fin to achieve a balance between performance improvement and material usage.Moreover,branch fins with larger arc angles are preferred in auxiliary-heating mode,while smaller arc angles are conducive to injecting heat into the wall along main fins in load-reduction mode and preventing the heat near the inner surface from being extracted.Under the direct influence of the strengthened invisible thermal barrier,Arc-finTABEs can reduce the amount of static insulation layer by 20%–80%while achieving equivalent thermal performances as conventional high-performance walls.展开更多
Dynamic operating envelopes(DOEs),as key enablers to facilitate distributed energy resource(DER)integration,have attracted increasing attention in the past years.However,uncertainties,which may come from load forecast...Dynamic operating envelopes(DOEs),as key enablers to facilitate distributed energy resource(DER)integration,have attracted increasing attention in the past years.However,uncertainties,which may come from load forecasting errors or inaccurate network parameters,have been rarely discussed in DOE calculation,leading to compromised quality of the hosting capacity allocation strategy.This letter studies how to calculate DOEs that are immune to such uncertainties based on a linearised unbalanced three-phase optimal power flow(UTOPF)model.With uncertain parameters constrained by norm balls,formulations for calculating robust DOEs(RDOEs)are presented along with discussions on their tractability.Two cases,including a 2-bus illustrative network and a representative Australian network,are tested to demonstrate the effectiveness and efficiency of the proposed approach.展开更多
The idea of envelope of a family of plane curves is an elementary notion in differential geometry. As such, its implementation in dynamic geometry environments is quite universal(Cabri,The Geometer's Sketchpad, Ci...The idea of envelope of a family of plane curves is an elementary notion in differential geometry. As such, its implementation in dynamic geometry environments is quite universal(Cabri,The Geometer's Sketchpad, Cinderella, Geo Gebra,...). Nevertheless, most of these programs return,when computing certain envelopes, both some spurious solutions and the curves that truly ?t in the intuitive de?nition of envelope. The precise distinction between spurious and genuine parts has not been made before: This paper proposes such distinction in an algorithmic way, ready for its implementation in interactive geometry systems, allowing a ?ner classi?cation of the different parts resulting from the current, advanced approach to envelope computation and, thus, yielding a more precise output, free from extraneous components.展开更多
In this paper, we prove the C^(1,1)-regularity of the plurisubharmonic envelope of a C^(1,1) function on a compact Hermitian manifold. We also present the examples to show this regularity is sharp.
文摘Fine structure and elemental composition of envelopes of 10 taxa of Trachelomonas and Strombomonas from natural freshwater bodies in China were studied and phylogeny of both genera were discussed. The results indicate that iron (Fe) and silicon (Si) are the primary mineral elements of the envelopes. Composition of mineral elements was uncorrelated with envelope color, however, it was highly correlated with the microarchitecture of the envelopes. Content of Si was higher than that of Fe in all species of Strombomonas and some species of Trachelomonas with rough surface. In most species of Trachelomonas, especially those with dense and smoothy surface, content of Fe was higher than that of Si. Based on the above results, we propose to assign those species of Strombomonas into Trachelomonas and consider them as a group of the latter. These species were the most primitive among the group with envelopes in Euglenaceae.
文摘As in homology, the notion of injectivity is introduced in the category whose objects are Hilbert C * module over a C * algebra and whose morphism are bounded module operators. The definition of injective envelopes of an extension of a Hilbert C * modules over a C * algebra is introduced, and is characterized in terms of the injectivity and essence. It is shown that every Hilbert C * module has a unique (up to H isometrics) injective envelope if it exists. It is also shown that an extension of a Hilbert C * module is an injective envelope if and only if it is an injective and essential extension. Moreover, every Hilbert C * module over a W * algebra has a unique (up to H isometrics) injective envelope and the injective envelope of a Hilbert C * module H is maximal essential extension of H .
基金Project(2006BAJ01A12-10-03) supported by the National Natural Science Foundation of ChinaProject(J50502) supported by the Leading Discipline of Shanghai Education Commission,China
文摘The integration of building with solar collector was studied. The theoretical model of integration of building envelopes and flat plate solar collectors was set up and the thermal performance of integration was studied in winter and summer,and compared to envelopes without solar collectors. The results show that the solar collection efficiency is raised in the integration of building envelopes and solar collectors with the air layer doors closed. This is true whether in winter or summer. The increment is higher as the inlet water temperature increases or the ambient temperature is low. In winter,the heat loss is significantly reduced through integration of the building envelopes and solar collectors with the closed air layer doors. The integration with the open air layer door is worse than that without collectors. In summer,the heat gains of the integration of envelopes and solar collectors are more obviously reduced than envelopes without collectors,the integration with the open air layer door is a little better than the closed one,but the difference is very small.
基金the National Natural Science Foundation of China (No.60572130)Jiangsu Provincial Natural Science Foundation (BK2006235)
文摘In order to better assess the performance of wireless communication systems,it is desirable to produce multiple Rayleigh fading envelopes with specified correlations.In this paper,we analyze theoretically a procedure which generates correlated Gaussian random variables from independent Gaussian random variables and give a physical explanation for the limitation of this procedure.Then,based on some uncorrelated Rayleigh fading envelopes,a simple but efficient procedure for generating an arbitrary number of cross-correlated Rayleigh fading envelopes is proposed.Simulation results and computational complexity analysis are presented,which show that the proposed method has some advantages,such as high accuracy,low computational complexity and easy implementation,over the conventional simulation method.
文摘The innovation of building envelopes is densely characterized, in the new design process, by new products of the building industry and intelligent robotic systems, making them efficient and dynamic in an eco-efficient environmental context and spatial flexibility. The goal is that of energy efficiency and environmental sustainability that invest above all the building production sector, pushing towards a circular economy with the use of clean energy resources and new artificial intelligence systems. The intelligence is highlighted through the optimization of the performance of new lightweight envelopes, in the technological design and the new building process, through Lean planning and Lean construction, Mass customization, with application of criteria, methods and tools. So there are innovative technological solutions, for environmental comfort and energy saving, and typological solutions with high performance level, with the use of innovative, adaptive, advanced, light materials with nanoproducts, intelligent IT systems, etc. We highlight the effectiveness of design with natural passive use of renewable energy and energy efficiency of the envelope as “skin” and relative increase in performance levels, in the interaction with the internal environment and natural dynamic flows and in the conversion of thermal and electrical energy. The methodologies are aimed at the application of digital technologies and soft robotic systems for the management and quality of services with technological and constructive solutions for dynamic interactive envelope and intelligent systems of double or triple skin, curtain walls, etc. The challenge is new design models of dynamic enclosures, on criteria and methods that guide the new rules on energy efficiency in buildings, for environmental sustainability and housing quality with the integration of soft robots.
文摘Building envelopes include facades and roof, which have the most interaction and exchange with outside and natural environment. In the future, meeting buildings various complicated needs with new technological advances necessitates a change and evolution in building envelopes. Controlling the energy consumption of the buildings is mostly through controlling the energy performance of the building envelopes. New technologies lead to the intelligent facades and envelopes. The envelope can be designed to be a part of the whole building＇s metabolism （energy production, storage and consumption） and morphology. The envelope would be a controlled part of the building which is managed through the central control system of the building, which connects it to other parts. It caused building envelope design to be changed fundamentally, so that there is a need to interact with engineering disciplines including computer engineering, mechanical engineering, material engineering and so on. All of these caused building envelope to get closer to biological and living systems. The physical restrictions which affect buildings system and living systems are the same. So they cause the same forces to shape the structure and form of the systems and the same rules to interact with the environment. The restrictions of material and energy resources caused living systems to be energy efficient and consuming less material. But the most important difference between living systems and building systems is in maximum use of different resources. As living systems use information maximally, the building system technology is based on using maximum energy. Now, there are many reasons and restrictions that building envelopes cannot act like living systems. But technological developments and contributing more disciplines in design and construction of building envelopes caused the future way of these envelopes get close to living systems for their energy efficiency. Some of living systems characteristics which the future building envelopes would have partially or benefit for the design process or construction are self-organization, evolution principles, hierarchical levels, processing energy, reaction to environmental stimuli and self-adjustment. Self-organization is achieved in some design software and in building material production for creating formal patterns. Evolution principles provide infrastructure for soft wares for optimization purposes and form creation. Hierarchical levels refer to giving hierarchical structure to the building envelopes through layering and designing different scales. Processing energy （metabolism） would be achieved through photovoltaic and solar collectors to produce energy and in passive systems for energy storage and distribution. Controlling solar radiation absorption and transmittance would help energy transfer from outside to building and vice versa. Reaction to environmental stimuli which is one of the most important characteristics of future building envelopes would use different types of active and passive sensors to create envelope mechanical reactions through material properties or collect data for processing in the control center to determine the right reaction. The reaction would be through different strategies such as changing properties and moving. Reaction could be passive or active. Self-adjustment can be achieved by control systems and processing units. All of these mean intelligent envelopes are essential parts of future buildings. Though it is now started with new design soft wares based on biological principles to optimize different parameters affecting the envelope function or to create the most efficient form.
文摘For plane singly-connected domains with insulating boundary and four point-sized contacts, C<sub>0</sub> …C<sub>3</sub>, van der Pauw derived a famous equation relating the two trans-resistances R<sub>01,23</sub>, R<sub>12,30</sub> with the sheet resistance without any other parameters. If the domain has one hole van der Pauw’s equation becomes an inequality with upper and lower bounds, the envelopes. This was conjectured by Szymański et al. in 2013, and only recently it was proven by Miyoshi et al. with elaborate mathematical tools. The present article gives new proofs closer to physical intuition and partly with simpler mathematics. It relies heavily on conformal transformation and it expresses for the first time the trans-resistances and the lower envelope in terms of Jacobi functions, elliptic integrals, and the modular lambda elliptic function. New simple formulae for the asymptotic limit of a very large hole are also given.
文摘Damage on surfaces often compromises the efficiency of some types of energy production, the safety and reliability of components, and ultimately increases costs. The environment can degrade the structural integrity of surfaces in service by the accumulation of large numbers of small destructive events, which based on the Central Limit Theorem leads to a Gaussian distribution of pit depth. In order to develop safety envelopes relating fracture loci with topological parameters of a brittle material, scatter plots were obtained and analyzed. Starting with an engineering surface, after 6 to 9 micrometers of average degradation depth, safety envelopes could be developed using average roughness and two other proposed parameters. Interestingly, maximum pit depth showed very low correlation with the location of fracture, at the early stage of degradation studied. This is attributed to relaxation of stress concentration at a given pit location due to the assuaging effect caused by neighboring pits. Additionally, energy at fracture was obtained, and a maximum relaxation region was observed. Analytical and experimental study of this region, as well as ductility effects are currently under research.
基金financially supported by the National Natural Science Foundation of China (Grant Nos.51890913 and 51879183)the China Harbour Engineering Company (Grant No.2018-ZJKJ-01)+2 种基金the China Scholarship Councilthe State Key Laboratory of Hydraulic Engineering Simulation and Safety,Tianjin University (Grant No.HESS-2019)the State Key Laboratory of Coastal and Offshore Engineering,Dalian University of Technology (Grant No.LP2120)。
文摘Helical anchor is a kind of novel foundation for floating offshore wind turbines,which should be subjected to combined tensile loading caused by wind,wave and current.However,the research about the capacity of helical anchor was mainly examined under uniaxial loading and scarcely explored under combined loading.In this study,three-dimensional finite element limit analysis is adopted to assess the bearing capacities of single-plate rigid helical anchors with different ratios of helix to shaft diameter,D_(H)/D_(S) and embedment ratios L/D_(S).Result shows that the vertical,horizontal and moment bearing capacities increase with increasing D_(H)/D_(S) and L/D_(S).The normalized V-H failure envelopes expands with increasing L/D_(S),while the normalized V-M failure envelopes tend to contract with the increase of D_(H)/D_(S).With increasing D_(H)/D_(S) or decreasing L/D_(S),the normalized H-M failure envelopes expand when the horizontal and moment loading act in the same direction and contract when they act in the opposite direction.The effect of D_(H)/D_(S) and L/D_(S) on the shape of H-M failure envelope become insignificant when L/D_(S)≥4.A series of failure mechanisms under different loading conditions were observed and can be used to explain the trend.Besides,a series of approximate expressions were proposed to fit the uniaxial bearing capacities and the failure envelopes.
文摘The frequency domain analysis of systems is an important topic in control theory. Powerful graphical tools exist in classic control, such as the Nyquist plot, Bode plots, and Nichols chart. These methods have been widely used to evaluate the frequency domain behavior of system. A literature survey shows that various approaches are available for the computation of the frequency response of control systems under different types of parametric dependencies, such as affine, multi-linear, polynomial, etc. However, there is a lack of tools in the literature to construct the Bode envelopes for the general nonlinear type of parametric dependencies. In this paper, we address the problem of computation of the envelope of Bode frequency response of a non-rational transfer function with nonlinear parametric uncertainties varying over a box. We propose two techniques to compute the Bode envelopes：first, based on the natural interval extensions （NIE） combined with uniform subdivision and second, based on the existing Taylor model combined with subdivision strategy. We also propose the algorithms to further speed up both methods through extrapolation techniques.
文摘The integral of the pulse self-demodulation in acoustic parametric array can be calculated in light of the Fourier convolution theorem.Instead of a rectangular pulse with two discontinuous edges,two kinds of primary envelopes are used,the waveforms and their spectra are investigated.An optimal ratio of the primary duration has been found theoretically.Experimental results support this theory.
文摘BACKGROUND Cardiovascular implantable electronic devices(CIEDs)are implanted in an increasing number of patients each year,which has led to an increase in the risk of CIED infection.Antibacterial CIED envelopes locally deliver antibiotics to the implant site over a short-term period and have been shown to reduce the risk of implant site infection.These envelopes are derived from either biologic or nonbiologic materials.There is a paucity of data examining patient risk profiles and outcomes from using these envelope materials in the clinical setting and comparing these results to patients receiving no envelope with their CIED implantation.AIM To evaluate risk profiles and outcomes of patients who underwent CIED procedures with an antibacterial envelope or no envelope.METHODS After obtaining Internal Review Board approval,the records of consecutive patients who underwent a CIED implantation procedure by a single physician between March 2017 and December 2019 were retrospectively collected from our hospital.A total of 248 patients within this period were identified and reviewed through 12 mo of follow up.The CIED procedures used either no envelope(n=57),a biologic envelope(CanGaroo®,Aziyo Biologics)that was pre-hydrated by the physician with vancomycin and gentamicin(n=89),or a non-biologic envelope(Tyrx^(TM),Medtronic)that was coated with a resorbable polymer containing the drug substances rifampin and minocycline by the manufacturer(n=102).Patient selection for receiving either no envelope or an envelope(and which envelope to use)was determined by the treating physician.Statistical analyses were performed between the 3 groups(CanGaroo,Tyrx,and no envelope),and also between the No Envelope and Any Envelope groups by an independent,experienced biostatistician.RESULTS On average,patients who received any envelope(biologic or non-biologic)were younger(70.7±14.0 vs 74.9±10.6,P=0.017),had a greater number of infection risk factors(81.2%vs 49.1%,P<0.001),received more high-powered devices(37.2%vs 5.8%,P=0.004),and were undergoing more reoperative procedures(47.1%vs 0.0%,P<0.001)than patients who received no envelope.Between the two envelopes,biologic envelopes tended to be used more often in higher risk patients(84.3%vs 78.4%)and reoperative procedures(62.9%vs 33.3%)than non-biologic envelopes.The rate of CIED implant site pocket infection was low(any envelope 0.5%vs no envelope 0.0%)and was statistically equivalent between the two envelope groups.Other reported adverse events(lead dislodgement,lead or pocket revision,device migration or erosion,twiddler’s syndrome,and erythema/fever)were low and statistically equivalent between groups(biologic 2.2%,non-biologic 3.9%,no envelope 1.8%).CONCLUSION CIED infection rates for biologic and non-biologic antibacterial envelopes are similar.Antibacterial envelopes may benefit patients who are higher risk for infection,however additional studies are warranted to confirm this.
文摘In this paper, for a sustainable building in a Mediterranean climate areas, the relation between envelope and energy is discussed. The relation between envelopes and energy has been considered in all the phases of the life building （construction phase and during operation）. This has been made through global assessment of massive envelopes （with or without insulation） realized with blocks of different materials： natural stone, concrete and brick. For these types of envelope the thermal comfort of the rooms, the energy requirement for cooling and heating, economic and environmental aspects （costs and embodied energy） in the life cycle of the building have been studied.
文摘It is now recognized that many geomaterials have nonlinear failure envelopes. This non-linearity is most marked at lower stress levels, the failure envelope being of quasi-parabolic shape. It is not easy to calibrate these nonlinear failure envelopes from triaxial test data. Currently only the power-type failure envelope has been studied with an established formal procedure for its determination from triaxial test data. In this paper, a simplified procedure is evolved for the development of four different types of nonlinear envelopes. These are of invaluable assistance in the evaluation of true factors of safety in problems of slope stability and correct computation of lateral earth pressure and bearing capacity. The use of the Mohr-Coulomb failure envelopes leads to an overestimation of the factors of safety and other geotechnical quantities.
文摘Two independent barrier envelopes are the usual requirement used in most well operations to avoid catastrophic accidents.These are classified as primary-concerning preventing the occurrence of a kick,and secondary-concerning controlling the kick to avoid a blowout.Barrier envelopes consist of barrier elements,thus verifying the quality of these elements is fundamental.Barrier elements may be either redundant or mandatory,and these relationships are what constitute the barrier envelopes.In this work,we present a methodology to evaluate well safety by identifying existing barrier elements and barrier envelopes and mapping their relationships through the usage of graphs technique.This technique explicitly states the relationship between barriers and between them and envelopes.It enables a simpler visualization for well designers and allows the development of computer programs to control the safety and integrity of wells,both in the design phase and during drilling.12 graphs are provided for a 4-phase well(conductor,surface,production,and drill-in),considering both the primary and secondary enve-lopes.Reasoning for constructing each graph is thoroughly provided.If these graphs are used,reliability values can then be assigned to each barrier element,which results in the reliability of entire barrier envelopes.This can be further extended to analyze the safety of each operation by applying the system to operational sequences and even comparing well designs.
基金co-sponsored by the National Natural Science Foundation of China(No.52208103)Fundamental Research Funds for the Central Universities(No.JZ2024HGTB0229)+2 种基金Opening Fund of Anhui Province Key Laboratory of Intelligent Building&Building Energy Saving(No.IBES2024KF05,IBES2024ZR03)Anhui Province University Outstanding Scientific Research and Innovation Team(No.2022AH010021)Scientific Research and Cultivation Project of Anhui Jianzhu University(No.2021XMK04).
文摘Thermally activated building envelopes(TABEs)are multifunctional component that combines structural and energy properties.Based on re-examining the heat charging processes,an arc-shaped metal-fin-enhanced TABE(Arc-finTABE)with directional heat charging features is proposed to optimize the thermal barrier formation process.A comprehensive parameterized analysis is conducted based on a validated mathematical model to explore the influence of 5 fin-structure design parameters and the static insulation thickness.Results verified that the directional charging strengthening fins can improve transient thermal performances of Arc-finATBE and enlarge horizontal and vertical sizes of the thermal energy accumulation area surrounding the pipeline,while the maximum growth in extra heat loss is less than 3.17%.From the perspective of promoting heat injection into expected areas,the straight main fin configurations with the angle of main fins of 30°,shank length ratio of 0.4 and no leftward mounted fins are preferred in load-reduction mode,while the angle of main fins of 150°,shank length ratio of 0.8 and multiple fin designs,especially with one of the main fins horizontally toward the indoor side,are more favorable in auxiliary-heating mode.Besides,it is recommended to add one arc-shaped branch fin to each main fin to achieve a balance between performance improvement and material usage.Moreover,branch fins with larger arc angles are preferred in auxiliary-heating mode,while smaller arc angles are conducive to injecting heat into the wall along main fins in load-reduction mode and preventing the heat near the inner surface from being extracted.Under the direct influence of the strengthened invisible thermal barrier,Arc-finTABEs can reduce the amount of static insulation layer by 20%–80%while achieving equivalent thermal performances as conventional high-performance walls.
基金supported by the CSIRO Strategic Project on Network Optimisation&Decarbonisation(No.OD-107890).
文摘Dynamic operating envelopes(DOEs),as key enablers to facilitate distributed energy resource(DER)integration,have attracted increasing attention in the past years.However,uncertainties,which may come from load forecasting errors or inaccurate network parameters,have been rarely discussed in DOE calculation,leading to compromised quality of the hosting capacity allocation strategy.This letter studies how to calculate DOEs that are immune to such uncertainties based on a linearised unbalanced three-phase optimal power flow(UTOPF)model.With uncertain parameters constrained by norm balls,formulations for calculating robust DOEs(RDOEs)are presented along with discussions on their tractability.Two cases,including a 2-bus illustrative network and a representative Australian network,are tested to demonstrate the effectiveness and efficiency of the proposed approach.
基金supported by the Spanish Ministerio de Economía y Competitividadthe European Regional Development Fund(ERDF)under Grant No.MTM2017-88796-P
文摘The idea of envelope of a family of plane curves is an elementary notion in differential geometry. As such, its implementation in dynamic geometry environments is quite universal(Cabri,The Geometer's Sketchpad, Cinderella, Geo Gebra,...). Nevertheless, most of these programs return,when computing certain envelopes, both some spurious solutions and the curves that truly ?t in the intuitive de?nition of envelope. The precise distinction between spurious and genuine parts has not been made before: This paper proposes such distinction in an algorithmic way, ready for its implementation in interactive geometry systems, allowing a ?ner classi?cation of the different parts resulting from the current, advanced approach to envelope computation and, thus, yielding a more precise output, free from extraneous components.
基金supported by National Natural Science Foundation of China (Grant Nos. 11571018 and 11331001)
文摘In this paper, we prove the C^(1,1)-regularity of the plurisubharmonic envelope of a C^(1,1) function on a compact Hermitian manifold. We also present the examples to show this regularity is sharp.
