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Fulltext Strengthening of RC Beams Using Externally Bonded Reinforcement Combined with Near-Surface Mounted Technique

Darain KMU, Jumaat MZ, Shukri AA, Obaydullah M, Huda MN, Hosen MA, et al.

Polymers (Basel), 2016 Jul 19;8(7).
PMID: 30974542 DOI: 10.3390/polym8070261

This study investigates the flexural behaviour of reinforced concrete (RC) beams strengthened through the combined externally bonded and near-surface mounted (CEBNSM) technique. The externally bonded reinforcement (EBR) and near-surface mounted (NSM) techniques are popular strengthening solutions, although these methods often demonstrate premature debonding failure. The proposed CEBNSM technique increases the bond area of the concrete⁻carbon fibre reinforced polymer (CFRP) interface, which can delay the debonding failure. This technique is appropriate when any structure has a narrow cross-sectional width or is in need of additional flexural capacity that an individual technique or material cannot attain. An experimental test matrix was designed with one control and five strengthened RC beams to verify the performance of the proposed technique. The strengthening materials were CFRP bar as NSM reinforcement combined with CFRP fabric as EBR material. The test variables were the diameter of the NSM bars (8 and 10 mm), the thickness of the CFRP fabrics (one and two layers) and the U-wrap anchorage. The strengthened beams showed enhancement of ultimate load capacity, stiffness, cracking behaviour, and strain compatibility. The ultimate capacity of the CEBNSM-strengthened beams increased from 71% to 105% compared to that of the control beam. A simulation method based on the moment-rotation approach was also presented to predict the behaviour of CEBNSM-strengthened RC beams.
The presence of polycyclic aromatic hydrocarbons (PAHs) in air particles and estimation of the respiratory deposition flux

Najurudeen NANB, Khan MF, Suradi H, Mim UA, Raim INJ, Rashid SB, et al.

Sci Total Environ, 2023 Mar 29;878:163129.
PMID: 37001671 DOI: 10.1016/j.scitotenv.2023.163129

Polycyclic aromatic hydrocarbons (PAHs) in the atmospheric particles constitute a topic of growing health concern. This study aims to calculate PAH concentrations, identify the source, assess the health risk from exposure to carcinogenic PAHs, and the respiratory deposition flux. PM10 and PM2.5 were collected in September 2019 in the urban, semi-urban, and semi-urban-industrial areas of Kuala Lumpur, Batu Pahat, and Bukit Rambai, respectively. A total of 18 PAHs from PM10 and 17 PAHs from PM2.5 were extracted using dichloromethane and determined using gas chromatography coupled with a flame ionization detector (GC-FID). The health risk assessment (HRA) calculated included B[a]P equivalent (B[a]Peq), lifetime lung cancer risk (LLCR), incremental lifetime cancer risk (ILCR), and respiratory deposition dose (RDD). The results show PAHs in PM10 recorded in Kuala Lumpur (DBKL), Batu Pahat (UTHM), and Bukit Rambai are 9.91, 8.45, and 9.57 ng/m3, respectively. The average PAHs in PM2.5 at the three sampling sites are 11.65, 9.68, and 9.37 ng/m3, respectively. The major source of PAHs obtained from the DRs indicates pyrogenic activities for both particle sizes. For PM10, the total B[a]Peq in DBKL, UTHM, and Bukit Rambai were 1.97, 1.82, and 2.32 ng/m3, respectively. For PM2.5 samples, the total B[a]Peq in DBKL, UTHM, and Bukit Rambai were 2.80, 2.33, and 2.57 ng/m3, respectively. The LLCR and ILCR show low to moderate risk for all age groups. The RDD of adults and adolescents is highest in both PM10 and PM2.5, followed by children, toddlers, and infants. Overall, we perceive that adults and adolescents living in the urban area of Kuala Lumpur are at the highest risk for respiratory health problems because of prolonged exposure to PAHs in PM10 and PM2.5, followed by children, toddlers, and infants.
Odds of HIV among incarcerated drug users: a systematic review and meta-analysis of Asian countries

Hussain HU, Kumar KA, Rehan ST, Khan Z, Hashmi MR, Khabir Y, et al.

Ann Med Surg (Lond), 2023 Nov;85(11):5584-5592.
PMID: 37915701 DOI: 10.1097/MS9.0000000000001242

BACKGROUND: HIV makes up a large portion of infectious diseases globally. People injecting drugs in prisons are at high risk for contracting HIV infection. Prisons house ~10.2 million people globally, making them a high-risk setting for HIV transmission. This systematic review summarizes the available data on the odds of developing HIV infection among imprisoned people who inject drugs (PWIDs) in Asian regions.
METHODS: The authors electronically assessed published studies from January, 2000 to December, 2022, including studies that investigated the odds of HIV in imprisoned PWIDs. We extensively searched PubMed, ERIC, and Cochrane Central and Google Scholar with no constraints in language or time. All the observational studies evaluating the chances of HIV in Asian prisoners with an exposure group of PWIDs and a control group of non-injecting-drug users were included in our analysis.
RESULTS: The databases search yielded 254 potential studies, 10 observational studies of which having a total of 17 333 participants were included. A low or moderate risk of bias was reported in all the studies except one case-control. The pooled analysis showed a significant association between PWIDs and the chances of contracting HIV infection (Odds ratio=6.40; 95% CI=3.89-10.52; P<0.00001; I2=53%).
CONCLUSION: This study found a vital correlation between injecting-drug usage during imprisonment and HIV transmission speed. The results of this meta-analysis support the need to prevent HIV and conducting treatment programs in high-risk settings like prisons.

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