Design consideration and modelling studies of ultrasound and ultraviolet combined approach for shelf-life enhancement of pine apple juice

Although both ultraviolet (UV) radiation and ultrasound (US) treatment have their capabilities in microbial inactivation, applying any one method alone may require a high dose for complete inactivation, which may affect the sensory and nutritional properties of pineapple juice. Hence, this study was intended to analyse and optimise the effect of combined US and UV treatments on microbial inactivation without affecting the selected quality parameters of pineapple juice. US treatment (33 kHz) was done at three different time intervals, viz. 10 min, 20 min and 30 min., after which, juice samples were subjected to UV treatment for 10 min at three UV dosage levels, viz. 1 J/cm², 1.3 J/cm², and 1.6 J/cm². The samples were evaluated for total colour difference, pH, total soluble solids (TSS), titrable acidity (TA), and ascorbic acid content; total bacterial count and total yeast count; and the standardization of process parameters was done using Response Surface Methodology and Artificial Neural Network. The results showed that the individual, as well as combined treatments, did not significantly impact the physicochemical properties while retaining the quality characteristics. It was observed that combined treatment resulted in 5 log cycle reduction in bacterial and yeast populations while the individual treatment failed. From the optimization studies, it was found that combined US and UV treatments with 22.95 min and1.577 J/cm² ensured a microbiologically safe product while retaining organoleptic quality close to that of fresh juice.     

Measuring and validation for isothermal solubility data of solid 2-(3,4-Dimethoxyphenyl)-5,6,7,8-tetramethoxychromen-4-one (nobiletin) in supercritical carbon dioxide

Isothermal solubility of 2-(3,4-Dimethoxyphenyl)-5,6,7,8-tetramethoxychromen-4-one (nobiletin) in supercritical carbon dioxide at temperatures of (313, 323 and 333) K and pressures from (18 to 31) MPa was measured using an analytic-recirculation methodology, with direct determination of the molar composition of the carbon dioxide-rich phase by using high performance liquid chromatography. Results indicated that the range of the measured solubility of nobiletin was from 107 · 10⁻⁶ mol · mol⁻¹ at T = 333 K and 18.35 MPa to 182 · 10⁻⁶ mol · mol⁻¹ at T = 333 K and 31.40 MPa, with a temperature crossover around 18 MPa. The validation of the experimental solubility data was carried out by using three approaches, namely, estimation of combined expanded uncertainty for each solubility data point from experimental parameters values (⩽77 · 10⁻⁶ mol · mol⁻¹); thermodynamic consistency, verified utilizing a test adapted from tools based on Gibbs–Duhem equation and solubility modelling results; and, self-consistency, proved by correlating the solubility data with a semi-empirical model as a function of temperature, pressure and pure CO₂ density.     

A review on key aspects of wet granulation process for continuous pharmaceutical manufacturing of solid dosage oral formulations

Wet granulation process is a major unit operation in production of pharmaceuticals as solid dosage oral formulation. Indeed, granulation is used to improve the formulation properties such as flowability, compressibility, and so on for pharmaceutical manufacturing. Different types of granulations can be used in pharmaceutical manufacturing in which the selection of proper process depends on the operational conditions as well as formulation properties. In current decades, twin-screw wet granulation has been of paramount interest owing to its superior properties. Pharmaceutical manufacturing industry are trying to move towards continuous mode by which the efficiency can be improved compared to the batch mode. Therefore, development of continuous granulation process is of great importance. In this review article, various processing units applicable for wet granulation of pharmaceutical formulations for solid dosage forms are reviewed and discussed. The advantages and disadvantages of the processes are discussed and listed along with modeling approaches for simulation of process. The governing models and numerical schemes applicable for design of wet granulation are also critically discussed. The main focus is on wet granulation as this method has attracted much attention in pharmaceutical processing.     

A detailed insight into the optimization of plate and frame heat exchanger design by comparing old and new generation metaheuristics algorithms

The voluminous utilization and application of plate and frame heat exchangers (PFHE) in many industries has accelerated the consumer and designer both to optimize exchanger total cost. Over the last few years, several old and new generation algorithms were employed and exploited to optimize PFHE cost. This study explores the application and performance of three new-generation algorithms Big Bang-Big Crunch (BBBC), Grey Wolf Optimizer (GWO), and Water Evaporation Optimization (WEO) in designing optimally PFHE. Besides, this study also compares the performance of three well-established old generations algorithms namely genetic algorithm (genetics and natural selection), particle swarm optimization (animals behaviour), and differential evolution (population-based) with the above three new algorithms in the optimization of PFHE.Seven design factors are chosen for PFHE optimization: exchanger length on hot and cold sides, height and thickness of fin, length of the fin-strip, fin frequency, and the number of hot side layers. The applicability of the suggested algorithms is assessed using a case study based on published research. Though DE performs the best in this study of design optimization concerning total cost and computational time, the three new-generation meta-heuristic algorithms BBBC, GWO, and WEO also provide the novel scope of application in heat exchanger design optimization and successfully finding the cost of the heat exchanger. According to this study, capital costs increase by 19.5% for BBBC, 24% for GWO, and 7.6% for GWO, but operational costs fall by 9.5% for BBBC and GWO when compared to the best performing algorithm (DE). On the other hand, WEO shows an increase of 32.6% in operational costs. Aside from that, a full analysis of the computing time for each algorithm is also provided. The DE has the quickest run time of 0.09 ?s, while the PSO takes the longest at 33.97 ?s. The rest of the algorithms have nearly identical values. As a result, a good comparison is established in this study, offering an excellent platform for designers and customers to make selections. Additionally, the three new generations algorithms mentioned here were not used earlier for optimization of PFHE and the comparative study illustrates that each of them possesses eat potential for cost optimization and also solving other complex problems.     

Slipping zone location in squeeze flow

In squeeze flow rheometry, the main problem is the boundary condition between the squeezed material and the plates. Therefore, the crucial assumption is to know the location and the shape of the sample part where wall slip may or may not occur. This question is investigated from experimental results. For this, squeeze flow experiments are carried out to visualize the flow pattern at the walls. Influence of boundary conditions is particularly studied using different plate surface condition. As a result, with wall slipping conditions, we propose a flow modelling divided into two zones: a circular central zone of the sample sticks on the plates and, beyond that zone, the sample slips at the plates with friction.     

Generalized layerwise mechanics for the static and modal response of delaminated composite beams with active piezoelectric sensors

A coupled linear layerwise laminate theory and a beam FE are formulated for analyzing delaminated composite beams with piezoactuators and sensors. The model assumes zig-zag fields for the axial displacements and the electric potential and it treats the discontinuities in the displacement fields due to the delaminations as additional degrees of freedom. The formulation naturally includes the excitation of piezoelectric actuators, their interactions with the composite laminate, and the effect of delamination on the predicted sensory voltage. The quasistatic and modal response of laminated composite Gr/Epoxy beams with active or sensory layers having various delamination sizes is predicted. The numerical results illustrate the strong effect of delamination on the sensor voltage, on through the thickness displacement and on the stress fields. Finally, the effect of delamination on modal frequencies and shapes are predicted and compared with previously obtained experimental results.     

Flexible Wiper System Dynamic Instabilities: Modelling and Experimental Validation

The optimization of wiper systems under various conditions and the creation of a product which is as robust as possible are the main objectives for an equipment supplier. However, in certain conditions, instabilities can appear and generate wiping defects due to the rubber-glass contact. To improve wiping quality and to reduce the number of test stages for design, this study proposes a wiper system modeling method. The wiper system is represented by a rigid blade holder on which a rubber blade is fitted. This rigid blade system is used on a flat test bench at constant wiping velocity. The model is based on modal synthesis methods and will be validated through comparison with experimental tests under various conditions. The right correlation obtained allows the same modelling method to be applied to the new generation of flexible wiper blades which take account of the degree of freedom of the wiper blade flexions. So, a new computation tool will be developed and validated through experimentation on a specific test bench.     

Comparison of different zero-slip definitions and a proposal to standardize tire traction performance

The traction properties of agricultural tires are of special importance because the tractive efficiency varies in a wide range to a maximum in the order of 75%. Different single wheel testing equipment is used to investigate tire performance and different mathematical methods are used to process the measured data. The different zero-slip definitions complicate a comparison between the measured data. In the paper the consequences of these differences are shown. For traction prediction it is necessary to make different measured and calculated data comparable so that all these data can be used for modelling tire behaviour. Therefore in this paper an effort to standardize tire traction performance is made.     

A Non-Linear SGS Model Based On The Spatial Velocity Increment

A new subgrid scale (SGS) modelling concept for large-eddy simulation (LES) of incompressible flow is proposed based on the three-dimensional spatial velocity increment δ u _i . The new model is inspired by the structure function formulation developed by Métais and Lesieur [39] and applied in the context of the scale similarity type formulation. First, the similarity between the SGS stress tensor τ _ij and the velocity increment tensor Q _ij = δ u _i δ u _j is analyzed analytically and numerically using a priori tests of fully developed pipe flow at Re _τ = 180. Both forward and backward energy transfers between resolved and unresolved scales of the flow are well predicted with a SGS model based on Q _ij . Secondly, a posteriori tests are performed for two families of turbulent shear flows. LES of fully developed pipe flow up to Re _τ = 520 and LES of round turbulent jet at Re _D = 25000 carried out with a dynamic version of the model provide promising results that confirm the power of this approach for wall-bounded and free shear flows.