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

Wholesaler characteristics and business practices.

<p>IQR: inter-quartile range; CI: confidence interval; N: number of wholesalers contributing to calculation of indicator.</p

Regulatory characteristics of wholesalers.

<p>CI: confidence interval; N: number of wholesalers contributing to calculation of indicator. 1: DRC pharmaceutical wholesale or retail licences do not possess expiration dates; but these licenses must be maintained on the business premises. 2 Health qualifications common across all countries include pharmacists, pharmacy technicians, pharmacy assistants, nurses, midwives, medical doctors, but some countries may include other categories. Note: 95% confidence intervals are derived using the standard Wald method and confidence limits that have been restricted to the lower limit of 0% and upper limit of 100% are marked with *.</p

Median number of AETDs of antimalarials sold during the week preceding the survey.

<p>N: number of wholesalers included in the sales volume analysis; ACT: artemisinin-based combination therapy; AMT: artemisinin monotherapy; nAT: non-artemisinin therapy; IQR: inter-quartile range. 1 The values for median number of AETDs sold reported for ‘all’ formulations include all dosage forms (tablets, suppositories, oral liquids, injectables and granules); however because so few wholesalers stocked suppositories or granules, and so few of these product types were observed during the audit, these dosage forms have been excluded from the tables here. 2 Notes on imputation: The number of wholesalers included in N whose sales volumes were set to zero as they did not stock antimalarials at the time of the survey but did at some point during the 3 months preceding the survey was 2 in Benin, 5 in Cambodia, 2 in the DRC, 2 in Nigeria, 1 in Uganda and 0 in Zambia. The number of wholesalers identified during the study for whom sales volumes were excluded or set to missing because they did not meet inclusion criteria or for various other reasons (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0093763#pone-0093763-t002" target="_blank">Table 2</a>) was 17 in Benin, 9 in Cambodia, 24 in the DRC, 68 in Nigeria, 14 in Uganda and 17 in Zambia. The percentage of audited antimalarial products that had missing sales volumes data which was imputed using the mi impute pmm command in Stata was 23.7% in Benin, 3.9% in Cambodia, 9.0% in the DRC, 35.7% in Nigeria, 3.4% in Uganda and 13.3% in Zambia.</p

Key characteristics of malaria epidemiology, treatment policy and pharmaceutical licensing by country.

<p>P: Plasmodium; ACT: artemisinin-based combination therapy; AL: artemether-lumefantrine; ASAQ: artesunate-amodiaquine; ASMQ: artesunate-mefloquine; CQ: chloroquine; DHA-PP-PQ: dihydroartemisinin-piperaquine-primaquine; DHA-PP: dihydroartemisinin-piperaquine; OTC: over-the-counter; PPMV: Proprietary Patent Medicine Vendors. * As part of the programme to contain the spread of artemisinin resistance, Cambodia’s treatment guidelines until early-2011 recommended the use of DHA-PP in the highest risk areas (combined with PQ where safe use has been demonstrated) and ASMQ everywhere else to treat P falciparum malaria, and DHA-PP for the treatment of P vivax malaria since 2011 (CQ was used previously). Since early-2011, Cambodia’s treatment guidelines have recommended the use of DHA-PP (combined with PQ where safe use has been demonstrated) for both P falciparum and P vivax malaria. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0093763#pone.0093763-Global1" target="_blank">[22]</a>.</p

Representation of the antimalarial distribution chain illustrating the types of supplier interactions documented by country.

<p>N: number of wholesalers with documented supplier interactions; WS: wholesaler; INT: intermediate. The shaded boxes represent the different levels of the distribution chain at which wholesalers operate, and the size of each box gives an impression of the proportion of wholesalers operating at each level. The dots represent mutually exclusive groups of wholesalers that are defined by the specific levels each wholesaler group serves. This is reflected in the array of arrows emanating from each dot, which illustrates that some wholesaler groups supply several distribution chain levels and others supply only one level. The percentages attached to each dot give the relative size of each wholesaler group. The dashed line from manufacturer to retailer indicates that while some retailers purchased antimalarials directly from manufacturers, it was an uncommon practice. Note that these schematics were constructed using information about the top two antimalarial supply sources mentioned by respondents, and therefore reflect the most important supplier interactions occurring within the antimalarial distribution chain, rather than all possible interactions or the volumes of antimalarials flowing through the chain.</p

František Palacký and Czech politics in the end of the last century

Timing of data collection in each country. (PDF 14 kb

Additional file 8: Figure S2. of Wealth and cardiovascular health: a cross-sectional study of wealth-related inequalities in the awareness, treatment and control of hypertension in high-, middle- and low-income countries

Adjusted prevalence of hypertension awareness, treatment and control with 95% confidence intervals within PURE cohorts, by wealth quintile and country (ordered by 2006 GDP). (PDF 26 kb