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New friction factor correlation for phase-change flow in plate heat exchangers
(Taylor and Francis, 2025) Mukkamala, Yagnavalkya; Dirker, Jaco
This article reports a new two-phase friction factor correlation for condensing and evaporating flows in plate heat exchangers. Over a thousand condensation pressure drop data compiled from seventeen articles were reduced to a two-phase friction factor correlation and successfully evaluated with data not used for correlation development. Similarly, over two thousand evaporation pressure drop data were collected from twenty-four articles and were empirically modeled to yield a two-phase friction factor, which was also successfully validated with independent data. The condensation friction factor correlation fit 72% of the data within ±50% and modeled 92% of the evaluation data within ±50%. Similarly, the evaporation friction factor correlation fit 64.9% of the data within ±50 and 89.8% of the evaluation data within ±50%. Pressure drop in condensers was predominantly due to convective condensation and buoyancy forces. Inertial forces and convective boiling were mainly responsible for the pressure drop in evaporators. As the Weber number was much <1, drop condensation and nucleate boiling were insignificant. Meta-analysis strongly recommended deploying plate heat exchangers as condensers for lowering the pressure drop and was inconclusive for evaporators.
Pilot of methadone for recently incarcerated people with human immunodeficiency virus and opioid use in South Africa
(Mary Ann Liebert, 2025) Bhoora, Urvisha; An, Yangxi; Owczarzak, Jill; Ndini, Pretty; Moyo, Derrick; Shelly, Shaun; Marcus, Tessa S.; Steiner, Laura; Corcoran, Peter C.; Pollock, Sarah; Lefoka, Moganki H.; Mabuto, Tonderai; Hugo, J.F.M. (Jannie); Hoffmann, Christopher J.
In South Africa, there is no provision of medication for opioid use disorder (MOUD) for people who are incarcerated or were recently incarcerated. This study aimed to describe MOUD uptake and barriers among people living with human immunodeficiency virus and using illicit opioids reentering the community from incarceration. A mixed-method exploratory study was conducted between September 2021 and September 2022 in South Africa, during which we offered low-barrier MOUD and harm reduction services. We followed 23 participants postrelease and observed a low uptake of MOUD after release (8 of 23, 35%). Reported barriers to MOUD included perceived ineffectiveness, a preference for residential withdrawal management, and delays in initiating MOUD. Innovation is needed in strategies to deliver MOUD and harm reduction in South Africa.
Higher genotyping performance of the applied biosystems TaqPath Seq HIV-1 genotyping kit against ViroSeq HIV-1 genotyping Kit in HIV protease, reverse transcriptase, and integrase regions
(Dove Press, 2025-04) Choga, Ontlametse Thato; Okafor, Obiageli; Lemogang, Goitseone Martha; Choga, Wonderful Tatenda; Muzanywa, Gaonyadiwe; Garcia, Andrea E.; Moyo, Sikhulile; Gaseitsiwe, Simani
PURPOSE : We assessed the performance of Applied Biosystems TaqPath Seq HIV-1 Genotyping Kit (CE-IVD) (TaqPath Kit) against the ViroSeq HIV-1 Genotyping Assays in genotyping HIV protease (PR), reverse transcriptase (RT), and integrase (INI) regions.
METHODS : The study included 43 HIV-1 plasma specimens: 20 from people living with HIV-1C and 23 well-characterized HIV-positive Virology Quality Assurance (VQA) samples with PR-, RT-, and INI mutations. VQA samples included HIV-1 subtypes A, B, C, D, F, G, CRFO2_AG and URF. HIV-1 RNA extracted from all specimens was tested with both genotyping assays. Known HIV drug resistance mutations (DRMs) were identified using the Stanford HIV drug resistance database. Sequencing success rates, nucleotide identity, and DRMs from the two commercial assays were compared.
RESULTS : Of 43 samples, TaqPath Kit amplified 93.0% (40) for HIV PR/RT and 97.7% (42) for HIV INI regions, compared to ViroSeq Assays, which amplified 69.8% (30) and 72.1% (31) for PR/RT and INI, respectively. The TaqPath Kit successfully sequenced 90.0% (36/40) PR/RT and 97.6% (41/42) INI amplicons, while ViroSeq Assays sequenced 53.3% (16/30) PR/RT and 87.1% (27/31) INI amplicons. The mean nucleotide similarity was 98.8% (SD ± 1.30), 99.6% (SD ± 1.32) and 99.2% (SD ± 0.72) for paired RT, PR and INI sequences, respectively. The TaqPath Kit detected 97.2% (35/36) of DRMs identified by the ViroSeq Assays and an additional 83 mutations and polymorphisms in samples that failed genotyping with the ViroSeq Assays. Among these, 85.5% (71/83) were confirmed by the reference sequence, including 39 major DRMs.
CONCLUSION : The TaqPath Kit demonstrated higher genotyping performance compared to the ViroSeq assays. The TaqPath Kit was able to detect DRMs in the PR, RT and INI regions of various HIV-1 subtypes, offering a critical tool to identify and monitor HIV drug resistance to new and existing antiretroviral drugs targeting these regions.
Caregiver beliefs about childhood development and schooling outcomes : a qualitative study in Mahikeng, South Africa
(Wiley, 2025-03) Palmer, Tom; Jaoude, Gerard Abou; Granados, Rolando Leiva; Batura, Neha; Booysen, Frederik; Ebersohn, L. (Liesel); Gram, Lu; Prost, Audrey; Salustri, Francesco; Skordis, Jolene
Although the role of the home in supporting early childhood development, early learning and school outcomes is well established, the perspectives of caregivers on child development and schooling outcomes are comparatively underexplored. This qualitative study was conducted with caregivers of children aged 6–10 years in Mahikeng, South Africa and aimed to explore their beliefs related to the interconnected developmental continuum of ECD, school readiness and educational outcomes. A total of 18 caregivers participated in focus group discussions, including 2 males and 16 females. Qualitative data were analysed using reflexive thematic analysis. We developed four themes: being present; guiding children through school; influencing language and cognitive development and raising the next generation. Caregivers expressed beliefs that they played an important role in early language and cognitive development and in socioemotional development for older children. However, their behaviour was not necessarily motivated explicitly by child outcomes. Additionally, caregivers described many contextual factors, such as high levels of unemployment and crime, that may constrain the ability of households to support child development. Design of effective caregiving interventions must be informed by contextual understanding and help to overcome these barriers.
Migration narratives in the book of Genesis and Japa syndrome among Nigerian youths
(AOSIS, 2025-03) Chukwuma, Onyekachi G.; u05141517@tuks.co.za
The book of Genesis has copious narratives on migration. This article studies the migration stories of Abram’s and Jacob’s families vis-à-vis migration among Nigerian youths. A study of these biblical narratives reveals that severe famine precipitated the movement of these patriarchs and their families. Abram’s and Sarai’s migration to Egypt, according to Genesis 12:10, was a result of famine. Genesis 46 and 47 record that Jacob’s family migrated to Egypt due to the severe famine in Canaan. Similarly, many Nigerian youths migrate to other countries such as Canada, the United Kingdom, South Africa, Australia, Austria, Ireland, Germany, et cetera to escape financial hardship and pursue greener pastures. To this end, the slang ‘Japa’ has become a household term among Nigerian youths. Japa is a new word for leaving one’s country for better living conditions. With narrative and descriptive analysis, this article studies relevant texts in Genesis and the Japa phenomenon among Nigerian youths. A comparative study reveals that bad living conditions are hugely associated with migration in the Old Testament and contemporary times. The high rate of unemployment, underemployment, and a lack of opportunities faced by Nigerian youths are hugely responsible for the mass migration. The study recommends that the Nigerian government create an enabling environment that promotes the financial stability of youths through better job opportunities and career growth.
CONTRIBUTION : Migration is a long-standing human activity that is generally attributed to the quest for better living conditions. In the Old Testament, famine was hugely responsible for movement from one biblical residence to another. Nigerian society has witnessed a mass migration of its youths to other countries to escape the present economic situation in the country. A comparative study shows that many people migrate because of uncomfortable situations in their residence locations; there are challenges associated with migration, and migration usually leads to improved living conditions.