RESUMO
Development of smaller, faster, and more powerful electronic devices requires effective cooling strategies to efficiently remove ever-greater heat. Phase-change heat transfer such as boiling and evaporation has been widely exploited in various water-energy industries owing to its efficient heat transfer mode. Despite extensive progress, it remains challenging to achieve the physical limit of flow boiling due to highly transitional and chaotic nature of multiphase flows as well as unfavorable boundary layer structures. Herein, a new strategy that promises to approach the physical limit of flow boiling heat transfer is reported. The flow boiling device with multiple channels is characterized with the design of micropinfin fences, which fundamentally transforms the boundary layer structures and imparts significantly higher heat transfer coefficient even at high heat flux conditions, in which boiling heat transfer is usually deteriorated due to the development of dryout starting from outlet regions and severe two-phase flow instabilities. Moreover, the approaching of physical limit is achieved without elevating pressure drop.
RESUMO
Severe palmoplantar hyperhidrosis affects about 1.5-2.8% of the general population. Plantar hyperhidrosis (PHH) is related to foot odor, cold feet, skin lesions and infections, and even instability when walking. Endoscopic Lumbar Sympathectomy (ELS) is the treatment of choice for this condition. However, few surgeons have used this technique over the past 20 years because of its technical difficulty. Two and 3 mm instruments, rather than the standard 5 mm instruments, have been used to improve the results of several standard laparoscopic procedures. Use of these minilaparoscopic instruments to perform ELS so far has not yet been published. We describe a technique for ELS using minilaparocopic instruments, which we have used for our last 70 cases and has become our standard technique. The aim of this study is to demonstrate the feasibility of this technique and its advantages compared to the conventional technique.
A hiperidrose palmoplantar grave afeta cerca de 1,5-2,8% da população geral. A hiperidrose plantar está relacionada a odor dos pés, pés frios, lesões cutâneas, infecções, e até instabilidade da marcha. A simpatectomia lombar endoscópica (endoscopic lumbar sympathectomy, ELS) é o tratamento de escolha para essa condição; entretanto, tem sido utilizada por poucos cirurgiões nos últimos 20 anos, devido à sua dificuldade técnica. Instrumentos de 2 e 3 mm em vez de 5 mm vêm sendo utilizados para melhorar os resultados de vários procedimentos laparoscópicos padrão. O uso desses instrumentos para realizar ELS ainda não foi descrito. Descrevemos a técnica para ELS usando microinstrumentos, a qual vem sendo usada para os nossos últimos 70 casos, pois passou a ser nosso procedimento padrão. O objetivo deste estudo é apresentar a experiência com essa modificação técnica, assinalando as vantagens em relação à técnica tradicional.
RESUMO
Abstract Severe palmoplantar hyperhidrosis affects about 1.5-2.8% of the general population. Plantar hyperhidrosis (PHH) is related to foot odor, cold feet, skin lesions and infections, and even instability when walking. Endoscopic Lumbar Sympathectomy (ELS) is the treatment of choice for this condition. However, few surgeons have used this technique over the past 20 years because of its technical difficulty. Two and 3 mm instruments, rather than the standard 5 mm instruments, have been used to improve the results of several standard laparoscopic procedures. Use of these minilaparoscopic instruments to perform ELS so far has not yet been published. We describe a technique for ELS using minilaparocopic instruments, which we have used for our last 70 cases and has become our standard technique. The aim of this study is to demonstrate the feasibility of this technique and its advantages compared to the conventional technique.
Resumo A hiperidrose palmoplantar grave afeta cerca de 1,5-2,8% da população geral. A hiperidrose plantar está relacionada a odor dos pés, pés frios, lesões cutâneas, infecções, e até instabilidade da marcha. A simpatectomia lombar endoscópica (endoscopic lumbar sympathectomy, ELS) é o tratamento de escolha para essa condição; entretanto, tem sido utilizada por poucos cirurgiões nos últimos 20 anos, devido à sua dificuldade técnica. Instrumentos de 2 e 3 mm em vez de 5 mm vêm sendo utilizados para melhorar os resultados de vários procedimentos laparoscópicos padrão. O uso desses instrumentos para realizar ELS ainda não foi descrito. Descrevemos a técnica para ELS usando microinstrumentos, a qual vem sendo usada para os nossos últimos 70 casos, pois passou a ser nosso procedimento padrão. O objetivo deste estudo é apresentar a experiência com essa modificação técnica, assinalando as vantagens em relação à técnica tradicional.
