Molds

The International Standard Organization (ISO) has recommended the use of Dichloran 18% glycerol agar (DG-18) to enumerate yeast and mold in food (ISO 21527-2:2008) with reduced water activity (aw) ≤ 0.95. This ISO method uses the Surface Spread technique (SS-t). According to the ISO standard procedure, pour plate method is allowed to perform after a proper validation of results using the same medium.  The objective of this study was to compare the Pour Plate technique (PP-t) and spread plate technique using DG18 agar medium to enumerate yeast & mold in tea and herbs (e.g. lemongrass). The DG 18 agar medium was also compared with Yeast extract Dextrose Chloramphenicol (YDC) agar to enumerate these microorganisms.

The tea samples and the herbs obtained from tea industry were used as the matrices for this study because these components have a water activity a less than 0.95. The sample preparation and the test were performed according to the ISO 21527-2:2008 standard procedures. Total of 20 samples of herbs and tea were used in this microbiological testing programme and the results were statistically analyzed using Paired- T test with Minitab-14. The DG-18 medium gave average yeast and mold counts in tea samples as 2.90±0.57 cfu (log)/g in SS-technique whereas PP technique gave 2.58±0.42  cfu (log)/g.  The fungal burden in herbs was 2.69 ±0.54 cfu (log)/g (SS-t) and 2.17 ±0.89  cfu (log)/g for PP-t. The YDC medium using pour plate technique gave average yeast and mold counts for tea and herb samples as 2.48 ±0.48 cfu (log)/g and 2.88 ±1.98 cfu (log)/g respectively.  The DG-18 agar medium with the same technique gave 2.58±0.42 cfu (log)/g and 2.17±0.89 cfu (log)/g for tea and herb samples respectively. The statistical analysis indicated that the results obtained either using two different media or using two different techniques with DG 18 medium were not significantly different

Mucegaiuri Mucegaiurile sunt fungii filamentoși, deci EK, care se reproduc prin spori sexuați și asexuați. Răspândire: • În sol până la 30 cm, în straturile superficiale, unde participă alături de bacterii la circuitul elementar chimic din natură. • Au un sistem enzimatic complex care le permite degradarea compușilor macromoleculari, substanțe ce pot fi transportate prin învelișurile celulare. • În combinație cu rădăcinile plantelor formează asociații numite micorize. • În aer, în special ca spori purtați de curenți. • În ape, în special în apele cu materie organică mai multă. • Se găsesc pe suprafața plantelor și pot produce boli (mucegaiuri fitopatogene) Importanța mucegaiurilor:

Amaranth is a highly nutritious grain whose consumption has increased over the last twenty years, mainly in North America and Europe, which is why in several Central and South American countries were conducted soil studies and production performance for evaluation these parameters. There are currently Bolivian companies engaged in the export of grain amaranth to different countries, though sometimes the burden is rejected due to violation of rules establishing the allowed amount of mold and aflatoxin in the grain, why aflatoxins become important subject of study.

Aspergillus flavus and Aspergillus parasiticus are fungi that are present in the environment and usually are associated with amaranth grain during storage. These fungi are producers of different types of aflatoxin, and the conditions of grain storage are factors that directly affect their production. For verification of the presence of these molds was performed by an analysis of the sample plate count with a mean result of 496.8 CFU / g of amaranth.

Grain moisture is one factor that can be controlled by the producer during drying, as the temperature during the storage time, which is why the study of the effect of these factors in the production of aflatoxin. For this purpose, stored grain amaranth to 7.5%, 12% and 20% humidity and 18°C, 35°C and 45°C, according to the factorial design carried out, the incubation period was three days.

The results showed that at a temperature of 18°C and a grain moisture of 7.5% and 12% have no aflatoxin production and similarly at 35°C and 7.5% moisture. In conducting the logistic regression results demonstrated that both factors are crucial in the production of the toxin, proving the hypothesis.

The flow of melted plastic in microparts is an interesting area to discover. Many studies have being conducted to understand the phenomena of polymer flow in microplastic parts. One type of study is the visualization of melted polymer flow. This work focuses on the observation of the micro-flow of melted Polypropylene (PP) using transparent polymethyl methacrylate (PMMA) mold. A PMMA mold with 0.5, 0.8, and 1.0mm diameter channels were fabricated and injected with melted PP using a custom made vertical plastic injection molding machine. The flow of the melted PP can be clearly seen through the PMMA transparent mold. The result of the experimental are compared with a result from finite element analysis (FEA) software, MoldFlow Part Advisor. The result shows a good agreement for 1.0 and 0.8mm channels, but not for the 0.5mm. It can be concluded that, the analysis software is not capable of predicting the flow for 0.5mm channel and less. Copyright © Taylor & Francis Group, LLC.

http://www.tandfonline.com/doi/pdf/10.1080/10426914.2010.480996

... Quadrini , F. ; Santo , L. ; Trovalusci , F. Direct molding of thermoplastic micro-parts . ... In the current state, the proposed experimental mold is suitable for rapid microparts production ... flow also gradually decreases as the pressure decreases and reaches the atmospheric pressure, if ...

... Quadrini , F. ; Santo , L. ; Trovalusci , F. Direct molding of thermoplastic micro-parts . ... In the current state, the proposed experimental mold is suitable for rapid microparts production ... flow also gradually decreases as the pressure decreases and reaches the atmospheric pressure, if ...

Mold infestations in buildings can be quite a dangerous and costly problem, especially when it involves the toxic black mold. Scientifically referred to as Stachybotrys chartarum, black mold has been linked with various health effects when ingested or inhaled. The health effects and symptoms of exposure to S.chartarum cover a significant range of health issues. As such, having a substantial knowledge of these health indicators is essential. The most common health effects and symptoms of S.chartarum are linked with the respiratory system. They include chronic sneezing, coughing, and irritation of the mucous membrane in the throat and the nose. Prolonged exposure usually leads to more severe health effects including vomiting, nausea, and bleeding in the lungs. In light of this, this paper highlights how exposure to black mold affects the lungs.

Abstract High temperature nanoimprinting of viscous polymers which are glassy at room temperature is usually performed using brittle and expensive molds made of inorganic materials. As a replacement, soft molds made of plastics or elastomers have been used because of their low cost and ease of fabrication. However, the deformation of polymer molds under pressure remains a major issue which limits their resolution in high temperature nanoimprinting. Moreover, the replicated structures are often broken or lack ...