Experimental study of the hydrodynamic behaviour of slug flow in a vertical riser

This paper presents an investigation of the hydrodynamics of slug flow in a vertical 67 mm internal diameter riser. The slug flow regime was generated using a multiphase air–silicone oil mixture over a range of gas (0.42<USG<1.35 m/s) and liquid (0.05<USL<0.38 m/s) superficial velocities. Electrical capacitance tomography (ECT) was used to determine: the velocities of the Taylor bubbles and liquid slugs, the slug frequencies, the lengths of Taylor bubbles and the liquid slugs, the void fractions within the Taylor bubbles and liquid slugs and the liquid film thicknesses. A differential pressure transducer was used to measure the pressure drops along the length of the riser. It was found that the translational velocity of a Taylor bubble (the structure velocity) was strongly dependent on the mixture superficial velocity. As the gas superficial velocity, was increased, the void fraction and the lengths of the liquid slugs and the Taylor bubbles were observed to increase. The increase in gas superficial velocity causes an increase in the frictional pressure drop within the pipe, whilst the total pressure drop (which is a sum of the hydrostatic and frictional pressure drop) along the length of the riser decreases. In addition, the frequencies of the liquid slugs were observed to increase as the liquid superficial velocity increases, but to be weakly dependant on the gas superficial velocity. The manual counting method for the determination of slug frequency was found to be in good agreement with the power spectral density (PSD) computed method

Health system barriers influencing timely breast cancer diagnosis and treatment among women in low and middle-income Asian countries: evidence from a mixed-methods systematic review.

Globally, breast cancer is the most common cancer type and the leading cause of cancer mortality among women in developing countries. A high prevalence of late breast cancer diagnosis and treatment has been reported predominantly in Low- and Middle-Income Countries (LMICs), including those in Asia. Thus, this study utilized a mixed-methods systematic review to synthesize the health system barriers influencing timely breast cancer diagnosis and treatment among women in Asian countries. We systematically searched five electronic databases for studies published in English from 2012 to 2022 on health system barriers that influence timely breast cancer diagnosis and treatment among women in Asian countries. The review was conducted per the methodology for systematic reviews and reported following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, while health system barriers were extracted and classified based on the World Health Organization (WHO)'s Health Systems Framework. The mixed-methods appraisal tool was used to assess the methodological quality of the included studies. Twenty-six studies were included in this review. Fifteen studies were quantitative, nine studies were qualitative, and two studies used a mixed-methods approach. These studies were conducted across ten countries in Asia. This review identified health systems barriers that influence timely breast cancer diagnosis and treatment. The factors were categorized under the following: (1) delivery of health services (2) health workforce (3) financing for health (4) health information system and (5) essential medicines and technology. Delivery of health care (low quality of health care) was the most occurring barrier followed by the health workforce (unavailability of physicians), whilst health information systems were identified as the least barrier. This study concluded that health system factors such as geographical accessibility to treatment, misdiagnosis, and long waiting times at health facilities were major barriers to early breast cancer diagnosis and treatment among Asian women in LMICs. Eliminating these barriers will require deliberate health system strengthening, such as improving training for the health workforce and establishing more healthcare facilities. [Abstract copyright: © 2022. The Author(s).

Logistic analysis of factors and perception of smallholder rubber farmers to intercrop: a case study involving rubber and plantain intercropping system in Ghana

Even though rubber tree (Hevea brasiliensis) is a major tree crop and is lucrative for small holder' farmers in Ghana, the 6 years waiting period to maturity constraints its establishment. Intercropping of rubber with food crops has been found to be a solution to this production constraint in most rubber producing countries. The objective of this study was to empirically assess farmers' perception on rubber/plantain intercropping and factors that directly affect rubber farmers' decision to intercrop rubber plantations with plantain. A multistage sampling technique was used to select 200 rubber farmers from the Central and Western regions of Ghana. Both descriptive and logistic regression models were used to analyze the data. About 83% of the rubber farmers were males. Based on the logit model analysis, gender, level of education, household size, farm size, member of association and experience in rubber farming were found to have significant influence on the adoption of rubber/plantain intercrop. Respondents see the potential adoption of rubber/plantain intercropping system as a means to improve food security, farmers' income and livelihood. Non-governmental organizations, Ghana Rubber Estates Limited (GREL) and Government should focus on strengthening its extension arm to develop more interpersonal contacts with potential rubber farmers. Policy makers, researchers and extension providers should closely work together with rubber farmers in identifying suitable rubber/plantain spacing and varieties on a case by case basis to ensure effective adoption and scaling out.Keywords: Food security, Ghana, GREL, Livelihood, Rubber and plantain intercroppin