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

Cross-sectional survey data.

The COVID-19 pandemic directly increased mortality and morbidity globally. In addition, it has had extensive indirect ill effects on healthcare service delivery across health systems worldwide. We aimed to describe how patient access to diabetes care was affected by the pandemic in Manila, the Philippines. We used an explanatory, sequential mixed method approach including a cross-sectional survey (n = 150) and in-depth interviews of patients (n = 19), focus group discussions of healthcare workers (n = 22), and key informant interviews of health facility administrators (n = 3) from October 2021 to January 2022. Larger proportions of patients reported absence of livelihood (67.3%), being in the lowest average monthly household income group (17.3%), and disruptions in diabetes care (54.0%) during the pandemic. They identified the imposition of lockdowns, covidization of the healthcare system, and financial instability as contributors to the reduced availability, accessibility, and affordability of diabetes-related consultations, medications, and diagnostics. At least a quarter of the patients experienced catastrophic health expenditures across all areas of diabetes care during the pandemic. Most healthcare workers and administrators identified telemedicine as a potential but incomplete tool for reaching more patients, especially those deemed lost to follow-up. In the Philippines, the pandemic negatively impacted access to essential diabetes care.</div

Likert scales used in the quantitative component of the mixed method study.

Likert scales used in the quantitative component of the mixed method study.</p

Patient socioeconomic status before and during the pandemic.

Patient socioeconomic status before and during the pandemic.</p

Summary of codes from the qualitative thematic analysis.

Summary of codes from the qualitative thematic analysis.</p

Study participant flow.

CHW–community health worker, DM–diabetes mellitus, IM–Internal Medicine, PGH–Philippine General Hospital, PURE–Prospective Urban and Rural Epidemiological Study; d–number of focus group discussions conducted, n–number of individual study participants included.</p

Patient-reported challenges in accessing diabetes care.

The proportion of patients reporting challenges, defined as being problematic on categorization of Likert scales, in the respective component of diabetes care and domain of access is represented by the y-axis. Asterisks (*) indicate statistically significant differences (p < 0.05) between time periods. There was no correction for multiple comparisons.</p

Demographic and clinical characteristics of study participants.

Demographic and clinical characteristics of study participants.</p

Interview and focus group discussion guides used in the qualitative component of the mixed method study.

Interview and focus group discussion guides used in the qualitative component of the mixed method study.</p

Standard for Reporting Qualitative Research (SRQR) checklist of items that should be included in reports of qualitative studies.

Standard for Reporting Qualitative Research (SRQR) checklist of items that should be included in reports of qualitative studies.</p