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Search Results: 1 - 10 of 217 matches for " mould "
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The Impact of Microbiological Pollutants on School Indoor Air Quality  [PDF]
Peter Fsadni, Bezzina Frank, Claudia Fsadni, Stephen Montefort
Journal of Geoscience and Environment Protection (GEP) , 2017, DOI: 10.4236/gep.2017.55004
Abstract: Asthma is common in children with allergens and mould influencing the development of the disease. Since children spend most of their time outside their homes within the school environment, school indoor air quality can directly influence their respiratory health. This study aims to identify microbiological contaminants in Maltese schools. The association between contaminants, respiratory health and school characteristics has been analysed. Five primary schools were selected with 9 to 11 years old students participating. Standardised health questionnaires, lung function tests, and school characterisation were performed. Dust samples were analysed for fungi, bacteria and allergens were performed. Penicillium/Aspergillus/Paecilomyces/Variotii (PenAsp) group had the highest median indoor concentration followed by Mycobacterial and Streptomyces species. There was a significant negative correlation between PenAsp and Mycobacterium spp levels in all the participating schools (r = ?0.42; p = 0.03). Cat allergen in classroom dust correlated positively with the number of cat owners (r = 0.43; p = 0.041). High exposure to fungi, bacteria and allergens was significantly associated with upper and lower airway atopy. School/classroom characteristics and cleaning protocols were significantly associated with exposure to these pollutants. In conclusion, fungi, bacteria, endotoxin, cat and dog allergens have been found to have a direct influence on school indoor air quality in the Maltese Islands. A significant association was observed between these contaminants and upper and lower airway atopy. Specific school, classroom, cleaning and maintenance characteristics have been identified as having a direct impact on indoor air quality.
Review on Mould Contamination and Hygrothermal Effect in Indoor Environment  [PDF]
Yuyan He, Qinghai Luo, Peihong Ge, Guojie Chen, Hanqing Wang
Journal of Environmental Protection (JEP) , 2018, DOI: 10.4236/jep.2018.92008
Abstract: Mould is an important factor which affects building environment and indoor air quality. Firstly, a variety of damages of mould contamination to human and building are reviewed. Then, the crucial factors of mould growth are analyzed; temperature and humidity are key factors. After that, the indoor mould growth models were analyzed. Heat and moisture transfer in building envelope is a key factor which affects mould growth environment; wall is sensitive to reach the critical condition which leads to mould growth and reproduction, results in contamination.
Electroforming of a Complex Mould Using an Acid-Mediated Copper Sulphate Bath  [PDF]
R. T. Ojo, C. Edechuku, B. Aremo, M. O. Adeoye, O. S. Teniola
Open Journal of Metal (OJMetal) , 2014, DOI: 10.4236/ojmetal.2014.42002
Abstract:
This work reports a procedure for the fabrication of a complex mould using the technique of electroforming. This was with a view to finding a cheaper and less labour-intensive mould production route practicable locally. A Plaster of Paris electroforming mandrel in the shape of a water bottle was produced and made electrically conducting with a layer of copper conducting paint. Considerations for electroform removal were made by applying a thin, chloroform-dissolvable epoxy layer beneath the conducting copper paint. Uniformity of deposition on the mandrel was accomplished with the construction of a special deposition bath with multiple copper anodes around its perimeter. The electroforming was done in the galvanostatic electro deposition mode for about 240 hrs in a 1 M Cu2SO4 bath with the deposition of elemental copper on the mandrel. Incidences of rising bath pH were mediated with concentrated H2SO4. A free-standing electroform representing the mould cavity was formed in the deposition. The product so formed was a reproduction of the net-shape of the mandrel exhibiting smooth surface finish. The electroforming was cast with an aluminum backing layer to complete its transformation into a split mould. The finished mould was comparable in appearance to the imported moulds in terms of appearance and reproduction of intricate surface patterns. The simplicity and low cost of this method significantly reduced the requirements for expensive instrumentation and highly skilled labour for mould production.
Characterization of Mould in Masonry in Hospital Environment—Case Study  [PDF]
Washington Batista de Souza, Adalberto Matoski
Open Journal of Civil Engineering (OJCE) , 2016, DOI: 10.4236/ojce.2016.64050
Abstract: The objective of this study is the characterization of mould inside and in the surface wall of a hospital. The present research was made on the wall of the Clinical Hospital of the Federal University of Paraná, Brazil. For the methodology the samples were extracted from the surface, mortar and brick. The samples were spread on Petri plates containing Sabouraud dextrose agar and incubated at 25 for seven days. The results of the 90 samples collected showed growth of 39% of colonies with the following distribution of microorganisms: Aspergillus (present in 27% of samples), Cladosporium, Absidia, Rhizopus, Rhodotorula, Fusarium, Penicillium and Aspergillus flavus. Within the investigated substrate, three species of different fungi were identified: Aspergillus flavus, Aspergillus fumigatus and Aspergillus niger.
Microbiological Profile of Some Ghanaian Herbal Preparations—Safety Issues and Implications for the Health Professions  [PDF]
Joseph A. Ampofo, Anthonia Andoh, Wilhermina Tetteh, Mohammed Bello
Open Journal of Medical Microbiology (OJMM) , 2012, DOI: 10.4236/ojmm.2012.23018
Abstract: Thirty-one herbal preparations produced and sold on the Ghanaian market were randomly purchased from sales outlets and analyzed for their microbiological quality by testing for the presence of total coliform bacteria, faecal coliform bac- teria, and total heterotrophic bacteria count. Also tested for was detection of pathogenic bacteria such as the Salmonella spp. and Clostridium spp. Opportunistic bacterial pathogens (Aeromonas spp., Enterococcus spp. and Pseudomonas spp.) and mould were also tested for. The herbal preparations tested came from different processing companies and in- cluded those labeled as suitable for treating arthritis, asthma, anaemia, diabetes mellitus, epilepsy, cough, hypertension, dysmenorrhoea, malaria, urine retention and loss of appetite. Aliquots of the various herbal products were cultured on various selective media. Eight (8) of the products showed the presence of all microorganism analyzed for including the pathogenic ones and are recommended not be used. Five (5) of the products did not have any microorganism present. Eleven (11) products showed the presence of only total heterotrophic bacteria and the values ranged from 1 to 94 cfu per ml. These two groups of total of sixteen (16) products can be used without any microbiological risk. Another three (3) products showed presence of only total heterotrophic bacteria but the values ranged from 118 to 1648 cfu per ml. Majority of the herbal preparations showed the presence of pathogenic bacteria. These three products may pose danger to the user can be used with caution. None of the herbal products recorded the presence of Enterococcus spp.
Numerical Experiments on Indoor Air Quality Considering Infiltration of Mould from Crawl Space  [PDF]
Motoya Hayashi, Haruki Osawa, Kenichi Hasegawa, Yoshinori Honma
Journal of Environmental Protection (JEP) , 2014, DOI: 10.4236/jep.2014.510086
Abstract:

How the air quality of crawl space influences the indoor air quality is investigated using a simulation program “Fresh 2010”, air leakage network models, and the measurement results on the mould concentrations in crawl spaces of detached houses. The annual changes of indoor mould concentrations were calculated using building models (a common wooden post-and-beam structure, improved wooden post-and-beam structure, wooden stud structure). In every structure, the concentrations in the case of exhaust ventilation system are higher than those of exhaust and supply ventilation system. The results show that it is necessary to control the air quality of crawl spaces and the infiltration from crawl spaces in order to keep indoor air quality good.

Characterization of Phosphide Platelets in Eutectic Sand Cast Cu-Sn-P Alloy  [PDF]
L. O. Mudashiru, T. M. Azeez, S. O. Afolabi, I. A. Babatunde
International Journal of Nonferrous Metallurgy (IJNM) , 2015, DOI: 10.4236/ijnm.2015.43004
Abstract: A procedure for evaluating the degree of spheroidization of phosphide platelets in cast Cu-4%Sn- 5%P alloys using fractal analysis was investigated. The specimens were obtained by melting copper and tin in an improvised clay mould raised to a temperature of 1850°C ± 20°C, holding for a period of 10 minutes to 1 hour to modify the aspect ratio of the phosphide platelets. It was found that these platelets have the tendency to change their shape from being spherical to more Euclidian shapes as time elapses. It was found that the inter-platelets distances are approximately equal with time. This effect was more pronounced in samples with high holding time.
Determination of Fungi Associated with Tomatoes (Lycopersicum esculentum M.) and Tomato Pastes
Fatih Kalyoncu,A. ?same Tamer,Mustafa Oskay
Plant Pathology Journal , 2005,
Abstract: Many plant pathogenic fungi are the subject of intense study because they cause disease symptoms that have a severe negative effect on the yield or quality of tomatoes (Lycopersicum esculentum M.) and its products. The common fungi associated with tomatoes and tomato pastes were determined and compared to get information on whether the mould content of the tomato pastes originate entirely from the tomato or from the soil. Eighteen species which belong to 7 fungal genera (Alternaria, Aspergillus, Fusarium, Mucor, Penicillium, Rhizopus and Trichoderma) among 250 mould isolates were determined of tomatoes and home-made tomato pastes collected from Manisa Province and its surrounding (Turkey). Alternaria alternata was the most prevalent fungal species. Members of Aspergillus niger group represent 1/6th of all the identified species. Seven of the species are the types of species that may potentially produce mycotoxins.
Investigation of the Yeast and Mould Floras in Some Ground Spices
Ayd?n Vural,Neval Berrin Arserim Kaya,Mahmut Mete
Dicle Medical Journal , 2004,
Abstract: In this study, yeast and mould floras of 60 spices samples that werecollected from different places of Diyarbak r have been investigated. Theyeast spices as Aspergillus flavus, A. fumigatus and A. niger and mouldspices as Candida tropicalis and C. albicans have been commonly isolatedfrom the spices samples.The ratios of yeast contamination in the samples of black pepper,cumin, allspice, ground hot red pepper, flaked pepper (red) and flakedpepper (black), investigated in this study, have been found as % 70, % 80,% 90, % 90, % 60 and % 30 respectively. As a result of high amount ofyeast contamination in spices samples, it is thought that there is a high riskof aflatoxin presence.Using the good and hygienically producing techniques at the stages ofharvest, production, processing, storage and selling with decontaminationapplications as sterilization, microwave and irradiation become effectiveeither in to prove the microbiological quality of the spices and eliminatingof the probable aflatoxin risk due to highly yeast contamination.
Erosion phenomena in sand moulds
A. Chojecki,J. Mocek
Archives of Foundry Engineering , 2008,
Abstract: Authors studicd the erosion phcnorncna in sand moulds pured with cast iron. Thc study comprises an evaluation of erosionresistance of thc three sands: grccn sand. sand bondcd with inorganic or organic bindcr. It was concluded that thc most resistant is [heclassic green sand with thc addition of 5 B coal dust. Resistance of the sand with organic binder is generally weak and dcvnds onkind of used raisin. Spccinl nztcntion was paid to the sands with no organic bindcr watcr glass and phospha~c. It was Sound that thcirrcsistance depends on dehydratation conditions. When the mould is stored in law humidity of atmosphcrc the very strong crosion canbe expected. It rcsul ts hrn thc micro fractures in the bridges of binders, joining the grains of the sable. This phcnomcna facilitates thetearing away of fragments of sand [tom the surface
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