Control of key technological and benchmark flows of polymer fluids poses a number of challenges. Some of them are nowadays under active investigation and rather far from complete under­stan­ding. This review considers such phenomena as both practically important and governed by funda­mental laws of rheology and non-linear fluid mechanics. We observe, shear bands in polymeric and other complex structured fluids (like wormlike micellar solutions or soft glassy materials), birefrigerent strands, peculiarities of stress and pressure losses in fluids moving through com­plex shape domains. These and other processes involve in­ho­mo­geneity, in­stabilities and tran­sient modes creeping in flow fields. In practical aspect this is of interest in such industrial process as polymer flooding for Enhanced Oil Recovery (EOR), where a flow inhomogeneity affects a poly­mer solution injectivity and residual oil saturation. The value of viscoelasticity in the polymer flooding is estimated. The obser­va­tion is con­clu­ded by some new results on relation between polymer concentration in solutions and viscoelastic traits of benchmark flows.

There are several factors that generate postharvest losses of Citrus sinensis, but none have been focused on the central jungle of the Junín region of Peru. The objective of this research was to evaluate postharvest losses of Citrus sinensis in the province of Satipo, Junín region of Peru, considering the stages of the production chain. The methodology was applied to descriptive and cross-sectional design. A sample of 10 orange trees, 3 transport intermediaries and 5 traders selected for compliance with minimum volume and quality requirements were used. The °Brix, pH and acidity characteristics of the fruit were determined. Subsequently, absolute and percentage losses were quantified through direct observation, surveys and interviews. The main postharvest losses of Citrus sinensis were 1.50% in harvesting and detaching, 1.75% in transport to the collection center, 2.23% in storage and transport by intermediaries, and 2.90% in storage and sale by retailers. The overall loss was 8.12% throughout the production chain and US$5.75 per MT of C. sinensis harvested. The main damages found were mechanical and biological, caused by poor harvesting and packaging techniques, precarious storage and careless transport of the merchandise.

This paper examines the impact of the COVID-19 pandemic on financial inclusion in China, a country with a significant agricultural sector and an evolving digital landscape. The pandemic has accelerated the shift towards digital financial services, underscoring disparities in access. This study explores the pre- and post-pandemic scenarios of financial inclusion in China, evaluates the economic and social impacts of the pandemic, and assesses the role of digital transformation in the financial sector. It also investigates the changing roles of commercial banks and microfinance institutions, the integration of technology in finance, and the development of rural-urban economic linkages. The paper aims to propose strategies to enhance financial inclusion, ensuring it reaches the most vulnerable, and concludes with recommendations for creating a more equitable and robust economic system.