New research developments suggest that nuclear reactors using fusion may enter the market sooner than imagined even for mobile applications, like merchant ship propulsion and remote power generation. This article aims...New research developments suggest that nuclear reactors using fusion may enter the market sooner than imagined even for mobile applications, like merchant ship propulsion and remote power generation. This article aims at pointing such developments and how they could affect nuclear fusion. The method is enumerating the main nuclear reactors concepts, identifying new technological or theoretical developments useful to nuclear field, and analysing how new recombination could affect feasibility of nuclear fusion. New technologies or experimental results do not always work the way people imagine, being better or worse for intended effects or even bringing completely unforeseen effects. Results point the following designs could be successful, in descending order of potential: aneutronic nuclear reactions using lattice confinement, aneutronic nuclear reactions using inertial along magnetic confinement, hybrid fission-lattice confinement fusion, and fission reactions.展开更多
System behavior description using states faces problems like state explosion, lack of clear definition of state, state identification and coordination between multiple agents. The goals of this work are to ease design...System behavior description using states faces problems like state explosion, lack of clear definition of state, state identification and coordination between multiple agents. The goals of this work are to ease design activity, to reduce engineering efforts, and to mitigate project risks. The proposed way is to improve information flow during design by adding definitions and some protocols or rules for communicating a specification or design description. This work presented an objective definition of system status (way of interaction with the rest of the world) along other concepts. This work focused in definitions as mind entities and their importance to rationalize work and mitigate project risks during design. This article presented some simple examples to illustrate the advantages of each aspect of proposed definition of system status and discussed limits and exceptions for such definition. The key finding was the proposed definition which was the simplest while keeping completeness at a given product breakdown level. Such definition of status enforced formal segregation of needs and solutions, and eased the inclusion of behavior definition in specifications.展开更多
This study presents the results of the preliminary tests performed using a kerma-area product (KAP) meter in order to verify its usefulness as a monitor chamber in a clinical X ray system, which will be used in ioniza...This study presents the results of the preliminary tests performed using a kerma-area product (KAP) meter in order to verify its usefulness as a monitor chamber in a clinical X ray system, which will be used in ionization chambers’ quality control program. The tests performed were repeatability, surface measurement uniformity, linearity with tube current, measurement variation changing the distance and field size, KAP chamber radiation attenuation, and energy dependence. The KAP meter has presented a good repeatability (a maximum variation of 0.4%);its surface has a homogeneous response (a maximum variation of 1.0% among the different irradiated regions);the response is linear with the tube current and the variation of the PKA along the distance is less than 3.43%. On the other hand, the results obtained for chamber attenuation and energy dependence show that some corrections must be applied when the measurements are made. The results have shown a good performance of the KAP meter, confirming that it is possible to use this instrument as a monitor chamber. However, it is important to highlight that some correction factors for energy dependence and chamber radiation attenuation must be considered.展开更多
Constructal law explains the sense of evolution (morphing to get access to flows) of finite size systems, but paradoxes do exist as not all vegetables have a tree form. Also, nature does not improve all animals for di...Constructal law explains the sense of evolution (morphing to get access to flows) of finite size systems, but paradoxes do exist as not all vegetables have a tree form. Also, nature does not improve all animals for displacement. This work aims at creating a model to explain those paradoxes about constructal l<span style="letter-spacing:-0.05pt;">aw. It adopted the system engineering technique of segregation bet</span>ween functions (abstract goals) and solutions (physical entities). Further, this work introduced the assumptions of flow under external threats and imperfect channels (subject to leakages and suboptimal form). Results showed that there are always elements doing four functions in all types of channels: to reduce entropy, to protect channel, to retain integrity and to drive flow. Although the four functions are always present, natural systems typically privilege one function over others, depending on environmental demands. As a solution to improve flows, animal brains also fit in the model of four functions. Human <span style="letter-spacing:-0.05pt;">mind seems to have groups of instincts associated </span></span><span lang="EN-US" style="font-size:10pt;font-family:"letter-spacing:-0.05pt;">with</span><span lang="EN-US" style="font-size:10pt;font-family:"letter-spacing:-0.05pt;"> each of the fou</span><span lang="EN-US" style="font-size:10pt;font-family:"">r channel design functions, leading to four behavior phenotypes and four motivations (prominence, inclusiveness, negativity prevention and tradition). Finally, this</span><span lang="EN-US" style="font-size:10pt;font-family:""> </span><span lang="EN-US" style="font-size:10pt;font-family:"">model (channels need to</span><span lang="EN-US" style="font-size:10pt;font-family:""> </span><span lang="EN-US" style="font-size:10pt;font-family:"">meet four goals) unified physics and animal psychology and extended applications of Constructal law to the fields of systems engineering methods, management, and psychological science.展开更多
This work looked for a unifying theory between physical-biological domain and social sciences. Constructal law unified physical and biological domain by telling the general sense in which flow systems tend to evolve. ...This work looked for a unifying theory between physical-biological domain and social sciences. Constructal law unified physical and biological domain by telling the general sense in which flow systems tend to evolve. Management theory looks for relations between institutions and human agency. Although being state of mind entities, institutions follow constructal law. This work proposed the main organization flows are information and credit. Biologic instincts derived from Darwinian natural selection are the driving or blocking forces of such flows. Once biologic instincts systematically block information and credit flows in large numbers, this work proposed every human organization must have institutions to inhibit some behaviors. Those institutions need to be present, at least partially, in formal rules of social groups. This way it is possible to predict expansion or downfall of human groups using objective and quantifiable data. Therefore, further studies may employ classical history to confirm this theory. This work analyzed some case studies to show qualitatively the application of proposed theory. Concluding, this work gave physically-biologically grounded guidance for institutional changes.展开更多
文摘New research developments suggest that nuclear reactors using fusion may enter the market sooner than imagined even for mobile applications, like merchant ship propulsion and remote power generation. This article aims at pointing such developments and how they could affect nuclear fusion. The method is enumerating the main nuclear reactors concepts, identifying new technological or theoretical developments useful to nuclear field, and analysing how new recombination could affect feasibility of nuclear fusion. New technologies or experimental results do not always work the way people imagine, being better or worse for intended effects or even bringing completely unforeseen effects. Results point the following designs could be successful, in descending order of potential: aneutronic nuclear reactions using lattice confinement, aneutronic nuclear reactions using inertial along magnetic confinement, hybrid fission-lattice confinement fusion, and fission reactions.
文摘System behavior description using states faces problems like state explosion, lack of clear definition of state, state identification and coordination between multiple agents. The goals of this work are to ease design activity, to reduce engineering efforts, and to mitigate project risks. The proposed way is to improve information flow during design by adding definitions and some protocols or rules for communicating a specification or design description. This work presented an objective definition of system status (way of interaction with the rest of the world) along other concepts. This work focused in definitions as mind entities and their importance to rationalize work and mitigate project risks during design. This article presented some simple examples to illustrate the advantages of each aspect of proposed definition of system status and discussed limits and exceptions for such definition. The key finding was the proposed definition which was the simplest while keeping completeness at a given product breakdown level. Such definition of status enforced formal segregation of needs and solutions, and eased the inclusion of behavior definition in specifications.
文摘This study presents the results of the preliminary tests performed using a kerma-area product (KAP) meter in order to verify its usefulness as a monitor chamber in a clinical X ray system, which will be used in ionization chambers’ quality control program. The tests performed were repeatability, surface measurement uniformity, linearity with tube current, measurement variation changing the distance and field size, KAP chamber radiation attenuation, and energy dependence. The KAP meter has presented a good repeatability (a maximum variation of 0.4%);its surface has a homogeneous response (a maximum variation of 1.0% among the different irradiated regions);the response is linear with the tube current and the variation of the PKA along the distance is less than 3.43%. On the other hand, the results obtained for chamber attenuation and energy dependence show that some corrections must be applied when the measurements are made. The results have shown a good performance of the KAP meter, confirming that it is possible to use this instrument as a monitor chamber. However, it is important to highlight that some correction factors for energy dependence and chamber radiation attenuation must be considered.
文摘Constructal law explains the sense of evolution (morphing to get access to flows) of finite size systems, but paradoxes do exist as not all vegetables have a tree form. Also, nature does not improve all animals for displacement. This work aims at creating a model to explain those paradoxes about constructal l<span style="letter-spacing:-0.05pt;">aw. It adopted the system engineering technique of segregation bet</span>ween functions (abstract goals) and solutions (physical entities). Further, this work introduced the assumptions of flow under external threats and imperfect channels (subject to leakages and suboptimal form). Results showed that there are always elements doing four functions in all types of channels: to reduce entropy, to protect channel, to retain integrity and to drive flow. Although the four functions are always present, natural systems typically privilege one function over others, depending on environmental demands. As a solution to improve flows, animal brains also fit in the model of four functions. Human <span style="letter-spacing:-0.05pt;">mind seems to have groups of instincts associated </span></span><span lang="EN-US" style="font-size:10pt;font-family:"letter-spacing:-0.05pt;">with</span><span lang="EN-US" style="font-size:10pt;font-family:"letter-spacing:-0.05pt;"> each of the fou</span><span lang="EN-US" style="font-size:10pt;font-family:"">r channel design functions, leading to four behavior phenotypes and four motivations (prominence, inclusiveness, negativity prevention and tradition). Finally, this</span><span lang="EN-US" style="font-size:10pt;font-family:""> </span><span lang="EN-US" style="font-size:10pt;font-family:"">model (channels need to</span><span lang="EN-US" style="font-size:10pt;font-family:""> </span><span lang="EN-US" style="font-size:10pt;font-family:"">meet four goals) unified physics and animal psychology and extended applications of Constructal law to the fields of systems engineering methods, management, and psychological science.
文摘This work looked for a unifying theory between physical-biological domain and social sciences. Constructal law unified physical and biological domain by telling the general sense in which flow systems tend to evolve. Management theory looks for relations between institutions and human agency. Although being state of mind entities, institutions follow constructal law. This work proposed the main organization flows are information and credit. Biologic instincts derived from Darwinian natural selection are the driving or blocking forces of such flows. Once biologic instincts systematically block information and credit flows in large numbers, this work proposed every human organization must have institutions to inhibit some behaviors. Those institutions need to be present, at least partially, in formal rules of social groups. This way it is possible to predict expansion or downfall of human groups using objective and quantifiable data. Therefore, further studies may employ classical history to confirm this theory. This work analyzed some case studies to show qualitatively the application of proposed theory. Concluding, this work gave physically-biologically grounded guidance for institutional changes.