Ceramic applications in the advanced Stirling automotive engine

The ideal cycle, its application to a practical machine, and the specific advantages of high efficiency, low emissions, multi-fuel capability, and low noise of the stirling engine are discussed. Certain portions of the Stirling engine must operate continuously at high temperature. Ceramics offer the potential of cost reduction and efficiency improvement for advanced engine applications. Potential applications for ceramics in Stirling engines, and some of the special problems pertinent to using ceramics in the Stirling engine are described. The research and technology program in ceramics which is planned to support the development of advanced Stirling engines is outlined

Investigation of small-scale hydrazine- fluorine injectors

Performance tests of shower-head, triplet, and like-on-like liquid hydrazine-fluorine injectors in uncooled rocket engin

Experiments with hydrogen and oxygen in regenerative engines at chamber pressures from 100 to 300 pounds per square inch absolute

Design of lightweight regeneratively cooled hydrogen-oxygen thrust chambe

Assessment of alternative power sources for mobile mining machinery

Alternative mobile power sources for mining applications were assessed. A wide variety of heat engines and energy systems was examined as potential alternatives to presently used power systems. The present mobile power systems are electrical trailing cable, electrical battery, and diesel - with diesel being largely limited in the United States to noncoal mines. Each candidate power source was evaluated for the following requirements: (1) ability to achieve the duty cycle; (2) ability to meet Government regulations; (3) availability (production readiness); (4) market availability; and (5) packaging capability. Screening reduced the list of candidates to the following power sources: diesel, stirling, gas turbine, rankine (steam), advanced electric (batteries), mechanical energy storage (flywheel), and use of hydrogen evolved from metal hydrides. This list of candidates is divided into two classes of alternative power sources for mining applications, heat engines and energy storage systems

Is Structural Differentiation in Localities a Single or Multidimensional Phenomenon? Alternative Measures and Relation to Population

Several measures of structural differentiation for various institutionalized areas of county development are compared. Evidence regarding the hypotheses that differentiation is a system-wide, unidimensional phenomenon and that it is related to population are investigated. Scalable dimensions are found to exist among county administrative characteristics, medical special ties, commercial services, and educational institutions. Guttman scales formed from the complexity of such development are often used along with population size as operational measures of locality differentiation. The four scales and population size are analyzed together using the Guttman-Lingoes Multiple Scalogram Analysis for three different points in time. It is concluded that the alternative measures of differentiation cannot be used interchangeably as equal or nearly equal measures of the concept. Population size and the differentiation of comnercial services, however, are close parallels. Their reliability as correlates of differentiation is consistent for three different points in time as indicated by the Guttman-Lingoes Multiple Scalogram Analysis. Theoretical implications are that differentiation cannot be viewed as a single phenomenon. Future research should consider separately different levels of development and rates of change depending on the type of differentiation considered. This will make the task for explanatory theory more complicated than it would have been had all measures of structural complexity proven to be tautologically related

Desulfurization Effects on a Light-Duty Diesel Vehicle NOx Adsorber Exhaust Emission Control System

Analyzes the effects on gaseous emissions, before and after desulfurization, on a light-duty diesel vehicle with a NOx adsorber catalyst

Punica granatum (Pomegranate) juice provides an HIV-1 entry inhibitor and candidate topical microbicide

BACKGROUND: For ≈ 24 years the AIDS pandemic has claimed ≈ 30 million lives, causing ≈ 14,000 new HIV-1 infections daily worldwide in 2003. About 80% of infections occur by heterosexual transmission. In the absence of vaccines, topical microbicides, expected to block virus transmission, offer hope for controlling the pandemic. Antiretroviral chemotherapeutics have decreased AIDS mortality in industrialized countries, but only minimally in developing countries. To prevent an analogous dichotomy, microbicides should be: acceptable; accessible; affordable; and accelerative in transition from development to marketing. Already marketed pharmaceutical excipients or foods, with established safety records and adequate anti-HIV-1 activity, may provide this option. METHODS: Fruit juices were screened for inhibitory activity against HIV-1 IIIB using CD4 and CXCR4 as cell receptors. The best juice was tested for inhibition of: (1) infection by HIV-1 BaL, utilizing CCR5 as the cellular coreceptor; and (2) binding of gp120 IIIB and gp120 BaL, respectively, to CXCR4 and CCR5. To remove most colored juice components, the adsorption of the effective ingredient(s) to dispersible excipients and other foods was investigated. A selected complex was assayed for inhibition of infection by primary HIV-1 isolates. RESULTS: HIV-1 entry inhibitors from pomegranate juice adsorb onto corn starch. The resulting complex blocks virus binding to CD4 and CXCR4/CCR5 and inhibits infection by primary virus clades A to G and group O. CONCLUSION: These results suggest the possibility of producing an anti-HIV-1 microbicide from inexpensive, widely available sources, whose safety has been established throughout centuries, provided that its quality is adequately standardized and monitored

Comparison of DNA extraction methods to improve the molecular diagnosis of Cryptosporidium spp. from fecal samples of calves

Cryptosporidium sp. es un parásito, protozoo que infecta a una gran variedad de hospedadores vertebrados. Entre las más de 30 especies validadas en el género, la especie zoonótica Cryptosporidium parvum es la principal causante de la criptosporidiosis bovina y representa una de las mayores causas de diarrea neonatal bovina. La vía de transmisión esfecal-oral, siendo el ooquiste, eliminado con las heces, el elemento infectante. La extracción de ADN genómico del parásito a partir de materia fecal es esencial para la determinación de la especie o de la subgenotipificación de Cryptosporidium spp. y uno de los desafíos actuales es mejorar la sensibilidad de los métodos moleculares de diagnóstico. En este trabajo evaluamos diferentes combinaciones de métodos de lisis de ooquistes y de extracción de ADN específico con el fin de aumentar la sensibilidad de su detección en aplicaciones downstream como por ejemplo la PCR diagnóstica, basada en la amplificación del gen ARN ribosomal 18S. Tanto la combinación de lisis alcalina y extracción con fenol-cloroformoalcohol isoamílico seguida de un kit comercial, como la aplicación directa del kit comercial -sin pasos previos- resultaron efectivas cuando utilizamos materia fecal como punto de partida. Posteriormente, comparamos la detección de ADN de Cryptosporidium spp. a partir de materia fecal versus ooquistes enriquecidos, resultando esta última más sensible ya que se incrementa el volumen de muestra procesable. Finalmente, a partir de ooquistes enriquecidos de Cryptosporidium spp. comparamos dos métodos para su ruptura y dos de extracción de ADN. Esto incluyó combinaciones de lisis alcalina vs. congelado-descongelado en nitrógeno líquido para la ruptura de ooquistes y la comparación de dos kits comerciales para la extracción de ADN. La combinación de dos pasos de lisis previos a la utilización del kit comercial no mejora la obtención de ADN específico. De esta manera el método más sensible y adecuado consiste en un paso de enriquecimiento de ooquistes yla aplicación directa del kit comercial. En conclusión, este protocolo optimizado logró mejorar la sensibilidad del diagnóstico molecular de Cryptosporidium sp. notablemente, lo cual posibilitará la detección del parásito en muestras con bajo número de ooquistes.Cryptosporidium sp. is a parasitic protozoa that infects a wide range of vertebrates. Among the 30 valid species, the zoonotic species Cryptosporidium parvum is the etiological agent of bovine cryptosporidiosis, representing one of the most important causes of neonatal diarrhea of bovines. The transmission route is fecal-oral and the oocyst, excreted with the feces, is the infective stage. Extraction of genomic DNA from oocysts starting from feces is essential for species determination and/or subgenotipification of Cryptosporidium spp. A current challenge is the improvement of the sensitivity of molecular diagnostic methods. In order to increase the quantity of isolated DNA and the sensitivity of its detection, we evaluated in this study the efficiency of different lysis and DNA extraction methods for posterior detection by diagnostic PCR, which is based on the amplification of the 18S rRNA gene. The combination of alkaline lysis and extraction by phenol-chloroform followed by the use of a commercial kit as well as the exclusive use of a commercial kit resulted effective when applied to fecal samples directly. On the other hand, the addition of a freeze-thaw step after alkaline lysis did not increase the efficiency of parasite DNA detection in this type of sample. Later, we compared the detection of DNA of Cryptosporidium spp. from oocyst-contaminated feces and partially purified oocyst suspensions, showing the latter higher sensitivity as the volume of processable sample is increased. Finally, two protocols for oocyst disruption and two for DNA isolation were compared from purified oocysts. These included combinations of alkaline lysis and freezethaw. The combination of two lysis methods did not improved the extraction of specific DNA. Thus, the most sensitive and adequate method consists of an oocyst enrichment step followed by the direct application of the commercial kit. In summary this optimized protocol significantly improved the sensitivity of C. parvum molecular diagnosis which could allow parasite detection in samples contaminated with low numbers of oocysts.Fil: Toledo, Jonathan. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Patobiología; ArgentinaFil: Lombardelli, Joaquín Andrés. Universidad Nacional de Río Cuarto. Facultad de Agronomía y Veterinaria. Departamento de Patología Animal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Galarza, Roxana. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe. Estación Experimental Agropecuaria Rafaela; ArgentinaFil: Tiranti, Karina Ivana. Universidad Nacional de Río Cuarto. Facultad de Agronomía y Veterinaria. Departamento de Patología Animal; ArgentinaFil: Garro, Carlos J.. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Patobiología; ArgentinaFil: Florin Christensen, Mónica. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Patobiología; ArgentinaFil: Schnittger, Leonhard. Universidad de Morón; Argentina. Instituto Nacional de Tecnologia Agropecuaria. Centro de Investigacion En Ciencias Veterinarias y Agronomicas. Instituto de Patobiologia Veterinaria. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Pque. Centenario. Instituto de Patobiologia Veterinaria.; Argentina. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Tomazic, Mariela Luján. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Patobiología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin