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High-acid liquid foods are a substrate in which foodborne pathogens can maintain their viability. In this research an experimental design was conducted to optimize the parameters for high pressure processing (HPP) of apple juice (pH 3.76).

Juice was inoculated with cocktails of Escherichia coli O157:H7, Salmonella enterica and Listeria monocytogenes. Pressures ranging from 139 to 561 MPa and dwell times between 39 and 181 s were challenged.

Pressures above 400 MPa achieved a greater than 5-log reduction in all pathogen cocktails regardless of the dwell time. L. monocytogenes was more sensitive to HPP at a pressure of 350 MPa and dwell times equal to or beyond 110 s. E. coli O157:H7 and S. enterica exhibited similar resistance; the number of log reductions in the central point (350 MPa/110 s) ranged from 2.2 to 3.7. The first-order mathematical model better fitted experimental data for E. coli O157:H7 and S. enterica. In regard to L. monocytogenes, the second-order model better fitted this pathogen's reduction.

Fruit juices are usually high pressure processed at approximately 600 MPa. For pathogenic reduction, the use of milder parameters may save energy and maintenance costs. The results herein exhibited could assist the apple juice industry with more effective applications of HPP.

The findings of this study demonstrate that relatively moderate pressures can be successfully used to assure the safety of apple juice.

High pressure processing (HPP) has been widely used for high-acid (pH<4.6) juices. The purpose of this study was to investigate optimal parameters aimed at achieving 5-log reduction of the pathogens of reference in Concord grape juice (pH 3.39).

Grape juice was inoculated with five strain cocktails of Escherichia coli O157:H7, Salmonella enterica and Listeria monocytogenes. In total, 11 trials were carried out based on a Central Composite Rotational Design (CCRD). The pressure (P), ranging from 319 to 531 MPa, and dwell time (t), from 35 to 205 s, were tested. The performance of the combinations (P × t) was evaluated by pathogen challenge microbiological assays.

E. coli O157:H7 was more resistant to HPP than S. enterica. L. monocytogenes did not grow in unprocessed juice (before HPP). Findings demonstrated that moderate pressures (~400 MPa) and short dwell times (~2 min) were effective in achieving a greater than 5-log reduction in the pathogens of reference.

Because the maintenance costs of equipment exponentially increase with pressure beyond 600 MPa, significant reductions in process pressure are highly desirable.

The results of this study can supplement the dearth of information on the applicability of high pressure as a Concord grape juice processing technology in terms of the pathogens inactivation. Furthermore, the use of a cocktail of five strains of pathogens inoculated in Concord grape juice to challenge different HPP parameters has not been reported.

With development of the modern electronic and mechanical devices, cooling requirement has become a serious challenge. Innovative heat transfer enhancement methods are generally accompanied by undesirable increase of pressure drop and consequently a pumping power penalty. The current study aims to present a novel and easy method to manufacture a mini heat sink using porous fins and magnetite nanofluid (Fe₃O₄/water) as the coolant for simultaneous heat transfer enhancement and pressure drop reduction.

A three-dimensional numerical study is carried out to evaluate the thermal and hydrodynamic performance of the mini heat sink at different volume fractions, porosities and Reynolds numbers, using finite volume method. The solver specifications for discretization of the domain involve the SIMPLE, second-order upwind and second order for pressure, momentum and energy, respectively.

Results show that porous fins have a favorable effect on both heat transfer and pressure drop compared to solid fins. Creation of a virtual velocity slip on the channel-fin interfaces similar to the micro scale conditions and the flow permeation into the porous fins are the main mechanisms of pressure drop reduction. On the other hand, the heat transfer enhancement is attributed to the increase of the solid-fluid contact area and the improvement of the flow mixing because of the flow permeation into the porous fins. An optimal porosity for maximum convective heat transfer enhancement is obtained as a function of Reynolds number. However, taking both pressure drop and heat transfer effects into account, the overall heat sink performance is shown to be improved at high of Reynolds numbers, volume fractions and fin porosities.

Thermal radiation and gravity effects are ignored, and thermal equilibrium is assumed between solid and fluid phases.

A maximum of 32 per cent increase of convective heat transfer is achieved along with a maximum of 33 per cent reduction in the pressure drop using porous fins and ferrofluid in heat sink.

This research aims to focus on developing a customized support surface using additive manufacturing (AM) for effective pressure relief for patients who are in bed or wheelchair suffering from pressure ulcers (PU).

A novel customized support surface is developed using AM technology incorporated with magnetic levitation and ball and socket mechanisms. Magnetic levitation provides cushioning effect for the developed cushion to users who are sitting in a wheelchair and increases the rate of healing. The ball and socket mechanism provides the user body's self-adaptive mechanism and reduces shear and friction forces between the surfaces of the additive manufactured cushion and the human buttocks.

From the results of ISO 16480-6 biomechanical standardized tests, the additive manufactured support surface performed better than, or on par with, the most widely available commercial cushions. It is evident that the developed cushion’s peak pressure values are lower when compared with other cushions. The overall efficiency of the developed cushion was qualitatively reported; 67% of people felt it was excellent and 22% of people responded as good and 11% were satisfactory. Henceforth, the overall effectiveness of the developed support surface provides a better experience to the end-user in the view of PU reduction.

A developed additive manufactured customized support surface will be an alternative approach for the reduction of PU, and it overcomes the drawbacks faced by the currently available cushions.

Shows how blood pressure increases with age in Western communities, where the amount of salt in the diet is relatively high. A reduction in salt consumption would lower blood pressure, which, in turn, would result in a substantial reduction in mortality due to stroke and to heart disease.

The main purpose of this research is to investigate distortion and duct total pressure loss at the duct exit (engine face) of a special S-shaped air intake at different simulated flight regimes with and without lip-screen installation. This air intake is supposed to be equipped with a micro jet engine.

Experimental investigations were performed by using a low subsonic close loop wind tunnel to simulate different flight regimes such as negative stall, cruise, shallow angle climb, steep angle climb and positive stall. In order to investigate flow behaviour along the duct length, static pressure changes were also measured. Test results were plotted in terms of total pressure contours and reduced results were tabulated. Static pressure results were also illustrated in different figures.

Results indicated that duct total pressure loss is within the acceptable range and is less than the 2 percent (allowable value) at various flight regimes, but installation of lip-screen has approximately reduced duct pressure recovery between 5 and 15 percent. Results also showed that mean distortion coefficient at duct exit is between 0.22 and 0.3, which is greater than the amount recommended by many jet engine producers.

It would be desirable to investigate the effects of flow control devices installed on this air intake in future researches.

It is highly recommended to practically examine any designed air intake to make sure it is geometrically optimized.

Current research developed an initial test bed for evaluation of the overall aerodynamic behavior of a previously designed special purpose S-shaped duct air intake. Obtained experimental results will help to analyze the internal flow characteristics of the current model as well as preparing data to compare with the future test results for improving its performance.

Recent studies suggest extensive use of environmental resources in agrofarming degrades ecosystem significantly. In this backdrop, this study aims at assessing ecoefficiency of paddy farming. Because ecoefficiency links up between economic performances and environmental resources supporting the provision of goods and services for the society, this study further investigates the effectiveness of attending Farmers' Field School (FFS), an agroenvironmental program, in conserving environmental resources through improving farm-level ecoefficiency.

In a dataset of 200 randomly selected paddy farmers from three districts of the southwestern Bangladesh, data envelopment analysis (DEA) is applied to compute both radial and pressure-specific (nutrient balance, energy balance, irrigation and pesticide lethal risk) ecoefficiency scores. Furthermore, propensity score matching (PSM) technique is applied to examine the impact of FFS program on farm-level ecoefficiency.

The DEA results suggest that paddy farmers are highly eco-inefficient. The computed radial eco-efficiency score is 0.40 implying farmers could reduce around 60% of environmental pressure equiproportionally even by maintaining the same level of value addition. In addition, the PSM results suggest farmers' participation in FFS program led to around 22.5% higher radial ecoefficiency and 7–25% higher environmental pressure-specific eco-efficiencies. Furthermore, simulation exercises reveal that FFS participation in interaction with farm size would lead to around 32–40% reduction of all environmental pressures.

Promoting FFS programs among paddy farmers could be an effective policy option to improve eco-efficiency through environment-friendly farming paradigm.

This study is probably the maiden effort that has examined the impact of attending the FFS program on ecoefficiency improvement in Bangladesh. This study contributes to both the concern literature by adding useful information and the policymakers by providing new insights about the reduction of environmental resource usage with maintaining the same value addition from agrofarming.

The purpose of this paper is to present a full 3D Computational Fluid Dynamics (CFD) analysis of the flow field through hydraulic directional proportional valves, in order to accurately predict the flow forces acting on the spool and to overcome the limitations of two-dimensional (2D) and simplified three-dimensional (3D) models.

A full 3D CAD representation is proposed as a general approach to reproduce the geometry of an existing valve in full detail; then, unstructured computational grids, which identify peculiar positions of the spool travel, are generated by means of the mesh generation tool Gambit. The computational grids are imported into the commercial CFD code Fluent, where the flow equations are solved assuming that the flow is steady and incompressible. To validate the proposed computational procedure, the predicted flow rates and flow forces are compared with the corresponding experimental data.

The superposition between numerical and experimental curves demonstrates that the proposed full 3D numerical analysis is more effective than the simplified 3D flow model that was previously proposed by the same authors.

The presented full 3D fluid dynamic analysis can be employed for the fluid-dynamic design optimization of the sliding spool and, more generally, of the internal profiles of the valve, with the objective of reducing the flow forces and thus the required control force.

The paper proposes a new computational strategy that is capable of recognizing all 3D geometrical details of a hydraulic directional proportional valve and that provides a significant improvement with respect to 2D and partially 3D approaches.

To review, analyze and present the effects of the contact‐fluid interfacial shear strength and contact‐fluid interfacial slippage and the critical importance of these effects in elastohydrodynamic lubrication (EHL).

The experimental and theoretical research results of the contact‐fluid interfacial shear strength and its caused contact‐fluid interfacial slippage in hydrodynamic lubrication and especially in EHL obtained in the past decades and progressed in recent years by the present author and by others are reviewed. Analysis and presentation are made on both the contact‐fluid interfacial shear strength versus fluid pressure curve for a given bulk fluid temperature in an isothermal EHL and the influence of the bulk fluid temperature on this curve.

It is very clearly and well understood from the present paper that the value of the contact‐fluid interfacial shear strength in the inlet zone in an EHL contact, i.e. at low EHL fluid film pressures is usually low and usually has rather a weak dependence on the EHL fluid film pressure. This proves the correctness of the EHL theories previously developed by the author based on the assumption of this low value and dependence on the EHL fluid film pressure of the contact‐fluid interfacial shear strength. It is also very clearly understood that the bulk fluid temperature usually has a strong influence on the value of the contact‐fluid interfacial shear strength in EHL and the increase of this temperature usually significantly reduces the value of the contact‐fluid interfacial shear strength in EHL.

A very useful material for the engineers who are engaged in the design of EHL on gears, cams and roller bearings, and for the tribology scientists who thrust efforts in studying EHL and mixed EHL both by theoretical modeling and by experiments.

A new and generalized mode of mixed EHL is originally proposed by incorporating the finding of a more realistic mode of the contact regimes in a practical mixed EHL based on the contact‐fluid interfacial shear strength and contact‐fluid interfacial slippage effects. This mode of mixed EHL should become the direction of the theoretical research of mixed EHL in the future.

DESPITE the quite extensive literature on foam, the mechanism of its formation and decay does not appear to be widely appreciated. Most fundamental research has been orientated towards maximum foam in aqueous solutions, whereas the desire in aircraft engines is for minimum foam in oil ‘solutions’. Further, the numerical results obtained experimentally depend on the details of experimental procedure, which makes correlation of existing data very uncertain.