Search results

Sinusoidal gravity modulation fields imposed on two‐dimensional Rayleigh‐Benard convection flow are studied to understand the effects of periodic source (g‐jitter) on fluids system and heat transfer mechanism. The transient Navier‐Stokes and energy equations are solved by semi‐implicit operator splitting finite element method. Results include two sets. One is considered at normal terrestrial condition and the other one is related to low‐gravity condition. Under low‐gravity condition the research focuses on the effects of modulation frequency and direction in order to find out the critical frequency for heat transfer mechanism transferring from conduction to convection.

The effects of normal surface suction and blowing on the Strouhal frequencies in vortex shedding over porous square cylinders was analysed numerically. The general characteristics determined were (1) an initial increase followed by a decreasing behaviour in the Strouhal frequency with increasing suction velocity and (2) a decrease in the Strouhal frequency with increasing blowing velocity. The numerical results were compared to an existing preliminary model, yielding fairly close agreement.

In part I uses an iterative point successive over‐relaxation (PSOR) finite difference scheme to solve the coupled unsteady Navier‐Stokes and energy equations for incompressible, viscous and laminar flows in their primitive variable form. Presents the details concerning the derivation of the solution scheme, as well as details on its computer implementation. For validation purposes, includes the results of the two‐dimensional and three‐dimensional benchmark problem of natural convection in a cavity with differentially heated vertical walls. Benchmark computations have been performed for a Prandtl number of 0.71, and different values of the Rayleigh number ranging between 10³ and 10⁶ depending on the problem. By comparison with other approaches in the literature, the scheme has been found to be accurate even for large Rayleigh numbers.

In part I of this study, a three‐dimensional finite difference iterative solver capable of handling the coupled Navier‐Stokes and energy equations for incompressible viscous flows was described and validated with two‐ and three‐dimensional benchmarks. Part II describes the results of the computational study of two distinct complex geometries: 1) two‐dimensional and three‐dimensional natural convection in cavity whose surface is cooled while two internal blocks are heated; 2) two‐dimensional and three‐dimensional natural convection in the region defined by two interconnected cavities of different sizes which are differentially heated. All computations have been performed for a Prandtl number of 1.0, and different values of the Rayleigh number ranging between 10³ and 10⁶ depending on the problem. In the first problem, three‐dimensional effects in the top region of the cavity trap fluid in vortices near the top of the heated blocks adversely affecting heat transfer in the region while enhancing it in the region between the two heated blocks. In the second problem, the sudden expansion of fluid as it leaves the top cavity and enters the bottom one generates three‐dimensional wakes in the bottom cavity that enhance the convective heat transfer across the system walls near them. These studies tend to suggest that three‐dimensional effects play a very important role in the enhancement of convective heat transfer in complex geometries, especially at higher Rayleigh numbers.

Millets are ancient grains, following wheat, that have been a fundamental source of human sustenance. These are nutrient-rich small-seeded grains that have gained prominence and admiration globally due to their super resilience in diverse climates and significant nutritional benefits. As millets are renowned for their nutritional richness, the demand for millet-based products increases. Hence, this paper aims in identifying the growing need for innovative processing techniques that not only preserve their nutritional content but also extend their shelf life.

In traditional times, heat was the only means of cooking and processing of the foods, but the amount of damage they used to cause to the sensorial and nutritional properties was huge. Millets’ sensitivity toward heat poses a challenge, as their composition is susceptible to disruption during various heat treatments and manufacturing processes. To cater to this drawback while ensuring the prolonged shelf life and nutrient preservation, various innovative approaches such as cold plasma, infrared technology and high hydrostatic pressure (HPP) processing are being widely used. These new methodologies aim on inactivating the microorganisms that have been developed within the food, providing the unprocessed, raw and natural form of nutrients in food products.

Among these approaches, nonthermal technology has emerged as a key player that prioritizes brief treatment periods and avoids the use of high temperatures. Nonthermal techniques (cold plasma, infrared radiation, HPP processing, ultra-sonication and pulsed electric field) facilitate the conservation of millet’s nutritional integrity by minimizing the degradation of heat-sensitive nutrients like vitamins and antioxidants. Acknowledging the potential applications and processing efficiency of nonthermal techniques, the food industry has embarked on substantial investments in this technology. The present study provides an in-depth exploration of the array of nonthermal technologies used in the food industry and their effects on the physical and chemical composition of diverse millet varieties.

Nonthermal techniques, compared to conventional thermal methods, are environmentally sound processes that contribute to energy conservation. However, these conveniences are accompanied by challenges, and this review not only elucidates these challenges but also focuses on the future implications of nonthermal techniques.

Strategic innovation through the deployment of a sophisticated collection of information systems and technologies to help accomplish financial inclusion for the urban poor.

This case is suitable for graduate courses on strategic planning and innovation.

Janalakshmi Financial Services (JFS) is a microfinance company that seeks to serve the financial service needs of the urban poor, a market segment with huge growthpotential. This operation involves large numbers of cash transactions making effective control mechanisms necessary. However, small margins make an innovative strategy necessary. JFS states that information technology (IT) is its DNA. The way in which the leadership team used a variety of ITsolutions to create an integrated set of well managed operations provides a very useful lesson in managing the process of strategic innovation.

The primary learning objective is to help the student understand the impact of strategic innovation through the use of information systems and technologies. This is achieved by helping the student to: connect the abilities provided by information technology to the social objective of financial inclusion; understand what financial inclusion means to the urban poor and how this segment differs from other microfinance and banking segments; assess the approach (related to organizational design as well as systems) JFS has employed to accomplish the objective of financial inclusion among the urban poor in India; analyse the systems and processes JFS has used to deliver services to its target market while making processes more transparent and efficient at JFS; and assess the risks to which JFS is exposed throughits business activity as well as the use of information technology.

Teaching notes are available; please consult your librarian for access.