Silver Nanoprismas Production Optimization by Using Fatorial Design
Rodrigues, J.F.B.*, Pinto, Maria Roberta de Oliveira., Fook, M.V.L., Barbosa, R.C., Santos, K.O,, Silva, R.N.A., Barreto, G.B.C.,Soares, C.R.D.M.
Abstract: The science and technology in nanoscale have attracted considerable attention in the last years; the expected impact of thenanostructured materials can improve the quality of life. The nanoparticles are thermodynamically unstable and have a natural tendency to aggregate and growth. Therefore, the great current challenge consists precisely in the preparation of stable and monodisperse nanomaterials, with regard to both size and the form of particles, which can be manipulated, scattered, deposited upon substrates without losing their characteristics. So they can be efficiently used in technology and biomedical applications, the nanostructured materials with the Silver nanoparticles (AgNp’s), should be able to remain stable for long periods, without loss of its properties, or structural modifications. This way, the search for new synthesis methods or functionalization focused on increasing the chemistry stability of nanoparticles it has become an important subject of research and study. The lack of planning it is often the cause of failure of an investigation; however, rare are the researchers who apply the statistic before making their experiments. This requires a set of observations and planning of experiments it is therefore, essential to indicate the design in which the verified hypothesis. The hypotheses are verified with the use of statistical analysis methods that depend on the manner in which the observations were obtained. Therefore, design factorial and analysis of results are linked closely and should be used in sequence in the scientific research of different areas of knowledge. Before that, the objective of this work is to perform the AgNp’s synthesis applying factorial design to set a trend and control of wavelength.
Keywords: Factorial design, silver nanoprismas, Nanotechnology.
Pages: 279 – 287 | Full PDF Paper
Detection of non O157:H7 Shiga toxin-producing Escherichia coli (STEC) serogroups O26, O45, O103, O111, O121 and O145 from beef trim in Namibia
Molini, U., Khaiseb, S. and Kamwi, J.
Abstract: Many different serotypes of Shiga toxin-producing Escherichia coli (STEC) that cause disease in humans have been described. Illnesses range from mild diarrhea to bloody diarrhea to hemorrhagic colitis (HC) and hemolytic uremic syndrome (HUS). E. coli O157:H7 is the STEC strain most often associated with the most severe forms of disease. However, numerous non-O157 STEC isolates have also been linked to illnesses and outbreaks of disease. Several studies showed that majority of non O157:H7 STEC infections are caused by strains from one of six major serogroups, including O26, O45, O103, O111, O121 and O145. 771 Beef trim obtained from a local abattoir in Windhoek were tested for the presence of the top 6 non-O157 STEC serogroups using commercial BAX® System assays. All samples were screened for the presence of Shiga toxin (stx1 and stx2) and intimin (eae) virulence genes, which were both present in 136 (17.64%) out of 771 samples. Of the 136 positive samples for both stx and eae virulence genes, nine were positive for O26, one for O45, thirty-three for O103, one for O111, five for O121 and three for O145. There were also thirty-five samples positive for more than one STEC serogroup.The presence of virulent STEC in beef trim is a public health concern. The use of polymerase chain reaction assay should aid quick detection of this virulent serotypes and help to prevent severe epidemic of human diseases associated with STEC infections.
Keywords: E.coli, Beef, PCR, STEC.
Pages: 288 – 294 | Full PDF Paper
Analysis Of Eucalyptus Oil Distillates Traditionally
Diana Julaidy Patty, Grace Loupatty
Abstract: Eucalyptus oil refinery in Namlea using water distillation (direct distillation method) where distillers process is the same as the desalination process for clove leaf. In this study, the raw material used eucalyptus leaves as much as 250 kg, without any treatment of the raw material. Calor average to heat the boilers on the first day and the second day 1371.69 Kcal and1499.54 Kcal. Results of laboratory analysis showed the quality of eucalyptus oil for refining and processing plant traditionally are quite popular among the public is used to show a significant difference. Distilling eucalyptus leaves (Melaleuca Cajuputi) produces eucalyptus essential oil, eucalyptus oil quality standards in Indonesia used SNI 06-3954-2006. For sample I (traditional) sineol content of 67.569%, the refractive index of 1.464, optical rotation 1.850, and a the specific gravity 0.849. For samples II (factory-made) Sineol Content 60, 186%, a refractive index of 1.467, -2.550 optical rotation, and a specific gravity of 0.845.
Keywords: eucalyptus oil, heat, SNI, Sineol content.
Pages: 295 – 302 | Full PDF Paper