MHD oxidant intermediate temperature ceramic heater study

The use of three types of directly fired ceramic heaters for preheating oxygen enriched air to an intermediate temperature of 1144K was investigated. The three types of ceramic heaters are: (1) a fixed bed, periodic flow ceramic brick regenerative heater; (2) a ceramic pebble regenerative heater. The heater design, performance and operating characteristics under conditions in which the particulate matter is not solidified are evaluated. A comparison and overall evaluation of the three types of ceramic heaters and temperature range determination at which the particulate matter in the MHD exhaust gas is estimated to be a dry powder are presented

Gel‐like Carbon Dots: Characterization and their Potential Applications

Highly photoluminescent gel‐like carbon dots (G‐CDs) were successfully synthesized for the first time by a rapid one‐step solvothermal synthesis approach with citric acid and 1,2‐ethylenediamine as the precursors. Their gel‐like nature was revealed by the Tyndall and coagulation effects, which were elucidated by a negative ζ potential value. The influences of temperature on the properties and sizes of these G‐CDs were analyzed, and the best method for a maximum quantum yield was identified. The resulting products emitted blue photoluminescence under UV light (λ=365 nm) and a gradient of color under regular light. In addition, the UV/Vis absorption and fluorescence emission spectra of the G‐CDs indicated that those synthesized at 160 °C exhibited the highest fluorescence quantum yield (33 %). Atomic force microscopy and transmission electron microscopy measurements were performed, and a higher temperature of formation resulted in smaller G‐CDs. Furthermore, band shifts in the UV/Vis and fluorescence spectra and sequential changes in the quantum yield values and ζ potentials in addition to elemental compositional changes as determined by X‐ray photoelectron spectroscopy were monitored throughout the formation process of the G‐CDs. As to applications, G‐CDs were prepared as an invisible ink for printers, which exhibited the applicability of G‐CDs in daily life and military activities. On the dot: Highly photoluminescent gel‐like carbon dots (G‐CDs) are synthesized and their gel network is confirmed by coagulation and Tyndall effects. To determine the effect of temperature on their formation, G‐CDs are synthesized at four different temperatures and then characterized by spectroscopy techniques. As to applications, an invisible ink is prepared from the G‐CDs for use in inkjet printers

Miopatias distais: análise clínica, laboratorial, eletromiográfica, histológico-histoquímica de oito casos

As miopatias distais são entidades raras e de difícil classificação. Descrevemos oito casos de miopatias distais, cinco do sexo masculino e três do feminino, em que, o início dos sintomas ocorreu aos 10 anos em cinco e aos 20 em três. O início dos sintomas se deu na musculatura distal dos membros inferiores e a seguir dos membros superiores, posteriormente afetando as porções proximais dos quatro membros. As enzimas séricas de origem muscular mostraram discreta elevação em cinco casos, moderada em um e importante em dois. As eletromiografias sugeriram miopatia primária em quatro, desinervação em dois e era de tipo neuromiopático em outro. As biópsias musculares revelaram sinais de envolvimento misto (miopatia e desinervação) em dois casos, miopatia crônica ativa em cinco e miopatia crônica em um. Quatro casos apresentavam vacúolos com conteúdo positivo na fosfatase ácida, em dois do tipo marginado. Seis casos mostraram importante aumento focal da fosfatase ácida, sugerindo patogenia com importante participação lisosomal. Dois dos casos foram classificados como miopatia distal autossômica recessiva variante de Welander; dois, como autossômica recessiva tipo Miyoshi; dois, como autossômica recessiva com vacúolos marginados (Myzuzawa e Nonaka); e dois, na classificação de miscelânea