Concrete sewer pipe corrosion induced by sulphuric acid environment

Corrosion of concrete sewer pipes induced by sulphuric acid attack is a recognised problem worldwide, which is not only an attribute of countries with hot climate conditions as thought before. The significance of this problem is by far only realised when the pipe collapses causing surface flooding and other severe consequences. To change the existing post-reactive attitude of managing companies, easy to use and robust models are required to be developed which currently lack reliable data to be correctly calibrated. This paper focuses on laboratory experiments of establishing concrete pipe corrosion rate by submerging samples in to 0.5 pH sulphuric acid solution for 56 days under 10ºC, 20ºC and 30ºC temperature regimes. The result showed that at very early stage of the corrosion process the samples gained overall mass, at 30ºC the corrosion progressed quicker than for other temperature regimes, however with time the corrosion level for 10ºC and 20ºC regimes tended towards those at 30ºC. Overall, at these conditions the corrosion rates of 10 mm/year, 13,5 mm/year and 17 mm/year were observed

Growth of Big Food and Big Tobacco sales in developing countries: An example.

<p>Shaded blue line is developed countries, dashed grey line is developing countries. Source: Passport Global Market Information Database: EuroMonitor International, 2011 <a href="http://www.plosmedicine.org/article/info:doi/10.1371/journal.pmed.1001242#pmed.1001242-EuroMonitor1" target="_blank">[12]</a>.</p

Association between publication output (1996–2010) and gross national product per capita (2008), Africa.

<p>Association between publication output (1996–2010) and gross national product per capita (2008), Africa.</p

Countries and territories with the fewest publications in medicine (1996–2010) in absolute numbers.

<p>Note: The term “United States Minor Outlying Islands" encompasses a group of Pacific atolls with no permanent population. While featured in only six publications, it has a high proportion of scientists among the 300 or so temporary visitors, incidentally, making it the territory with the highest number of publications per head of population in the world.</p

Countries and territories with the fewest publications in medicine (1996–2010) per capita.

<p>Countries and territories with the fewest publications in medicine (1996–2010) per capita.</p

Association between publication output (1996–2010) and total health expenditure per capita (2008), Africa.

<p>Association between publication output (1996–2010) and total health expenditure per capita (2008), Africa.</p

Trade challenges raised against low- and lower-middle–income countries.

<p>Notes: node colour represents country income levels, grouped into quartiles from lowest to highest. Red = Q1, orange = Q2, blue = Q3, and green = Q4. Lines show challenges raised by and to each node. Node size corresponds with the number of challenges raised (min = 1; max = 12). The proximity of nodes to one another corresponds to the frequency of challenges raised against another node (min = 1; max = 5).</p

Food, tobacco, and beverage products that were regulated by measures later subject to trade challenges.

<p>Food, tobacco, and beverage products that were regulated by measures later subject to trade challenges.</p

Top 10 manufacturers of packaged foods.

<p>Top 10 manufacturers of packaged foods.</p

Model diagram.

<p>Health states are further divided into age-, gender- and location-specific (urban and rural) submodels. Deaths from non-cardiovascular events are calculated from each compartment of the model at each time point in the simulation (not drawn). The transition probabilities between health states in the model are detailed in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0044037#pone.0044037.s008" target="_blank">Tables S1</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0044037#pone.0044037.s009" target="_blank">S2</a> and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0044037#pone.0044037.s010" target="_blank">S3</a>. Dietary salt reduction in the model lowers the risk of incident and recurrent myocardial infarction and stroke events. MI: myocardial infarction.</p