Analysis of squat shear wall with different dimensions and position of opening under different type of static loads

Shear walls are usually used in high-rise building or building on high frequency of wind area as the structural element to restrain lateral forces. Openings are created on the shear wall for the architecture, ventilation or mechanical and electrical purposes. With the existence of the opening, the strength of the wall is reduced by the reduction in concrete area and the discontinuity of the reinforcement due to opening which may lead to structural failure. The main objective is to study the effect of size and position of the opening towards the structural behavior of the shear wall under different type of static loads. The analysis is done using the software ANSYS12.0. The samples are SW1, SW2, SW3, SW4, SW5, SW6, SW7 and SW8 where SW1 is solid shear wall while SW2, SW3, SW4, SW5, SW6, SW7 and SW8 are shear walls with different size and position of opening. They are analyzed by using 2 different types of loads which are uniformly distributed axial load and uniformly lateral load. From the same magnitude of loads applied towards the shear walls, they are compared by the cracking pattern and the stress distribution. Under both axial and lateral loads, it shows a significance results that the shear wall with greater opening size shows less efficiency. The position of opening further from the support shows a more significance effect towards the strength of the wall from axial load but opposite from the lateral load. Besides, the closer the position of the shear wall to the load, the less efficient it is. As a conclusion from the results, the most suitable position of the opening on the shear wall is further from the support and the loads and it shows that there is a significance effect even from a smallest opening

High-Throughput Sequence Analyses of Bacterial Communities and Multi-Mycotoxin Profiling During Processing of Different Formulations of Kunu, a Traditional Fermented Beverage

Kunu is a traditional fermented single or mixed cereals-based beverage popularly consumed in many parts of West Africa. Presently, the bacterial community and mycotoxin contamination profiles during processing of various kunu formulations have never been comprehensively studied. This study, therefore, investigated the bacterial community and multi-mycotoxin dynamics during the processing of three kunu formulations using high-throughput sequence analysis of partial 16S rRNA gene (hypervariable V3-V4 region) and liquid chromatography tandem mass spectrometry (LC-MS/MS), respectively. A total of 2,303 operational taxonomic units (OTUs) were obtained across six processing stages in all three kunu formulations. Principal coordinate analysis biplots of the Bray-Curtis dissimilarity between bacterial communities revealed the combined influences of formulations and processing steps. Taxonomically, OTUs spanned 13 phyla and 486 genera. Firmicutes (phylum) dominated (relative abundance) most of the processing stages, while Proteobacteria dominated the rest of the stages. Lactobacillus (genus taxa level) dominated most processing stages and the final product (kunu) of two formulations, whereas Clostridium sensu stricto (cluster 1) dominated kunu of one formulation, constituting a novel observation. We further identified Acetobacter, Propionibacterium, Gluconacetobacter, and Gluconobacter previously not associated with kunu processing. Shared phylotypes between all communities were dominated by lactic acid bacteria including species of Lactobacillus, Lactococcus, Leuconostoc, Pediococcus, and Weissella. Other shared phylotypes included notable acetic acid bacteria and potential human enteric pathogens. Ten mycotoxins [3-Nitropropionic acid, aflatoxicol, aflatoxin B1 (AFB1), AFB2, AFM1, alternariol (AOH), alternariolmethylether (AME), beauvericin (BEAU), citrinin, and moniliformin] were quantified at varying concentrations in ingredients for kunu processing. Except for AOH, AME, and BEAU that were retained at minimal levels of < 2 μg/kg in the final product, most mycotoxins in the ingredients were not detectable after processing. In particular, mycotoxin levels were substantially reduced by fermentation, although simple dilution and sieving also contributed to mycotoxin reduction. This study reinforces the perception of kunu as a rich source of bacteria with beneficial attributes to consumer health, and provides in-depth understanding of the microbiology of kunu processing, as well as information on mycotoxin contamination and reduction during this process. These findings may aid the development of starter culture technology for safe and quality kunu production

Traditionally processed beverages in africa: a review of the mycotoxin occurrence patterns and exposure assessment

African traditional beverages are widely consumed food-grade liquids processed from single or mixed grains (mostly cereals) by simple food processing techniques, of which fermentation tops the list. These beverages are very diverse in composition and nutritional value and are specific to different cultures and countries. The grains from which home-processed traditional beverages are made across Africa are often heavily contaminated with multiple mycotoxins due to poor agricultural, handling, and storage practices that characterize the region. In the literature, there are many reports on the spectrum and quantities of mycotoxins in crops utilized in traditional beverage processing, however, few studies have analyzed mycotoxins in the beverages themselves. The available reports on mycotoxins in African traditional beverages are mainly centered on the finished products with little information on the process chain (raw material to final product), fate of the different mycotoxins during processing, and exposure estimates for consumers. Regulations targeting these local beverages are not in place despite the heavy occurrence of mycotoxins in their raw materials and the high consumption levels of the products in many homes. This paper therefore comprehensively discusses for the 1st time the available data on the wide variety of African traditional beverages, the mycotoxins that contaminate the beverages and their raw materials, exposure estimates, and possible consequent effects. Mycotoxin control options and future directions for mycotoxin research in beverage production are also highlighted