Multivariate KPI for energy management of cooling system in food industry

Within EU, the food industry is currently ranked among the energy-intensive sectors, mainly as a consequence of the cooling system shareover the total energy demand. As such, the definition of appropriate key performance indicators (KPI) for ammonia chillers can play a strategic role for the efficient monitoring of the energy performance of the cooling systems. The goal of this paper is to develop an appropriate management approach, to account for energy inefficiency of the single compressors, and to identify the specific variables driving the performance outliers. To this end, a new KPI is proposed which correlates the energy consumption and the different process variables. The construction of the new indicator was carried out by means of multivariate statistical analysis, in particular using Kernel Partial Least Square (KPLS).This method is able to evaluate the maximum correlation between dataset and energy consumption employing nonlinear regression techniques. The validity of the new KPI is discussed on a case study relevant to the cooling system of a frozen ready meals industry. The assessment of the proposed metric is one against Specific Energy Consumption (SEC) like indicator, typically used in the context of the Energy Management Systems

A penetration efficiency model for the optimization of solid conical microneedles’ geometry

Microneedles (MNs) are promising alternatives to pills and traditional needles as drug delivery systems due to their fast, localized, and relatively less painful administration. Filling a knowledge gap, this study investigated and optimized the most influential geometrical factors determining the penetration efficiency of MNs. The effects of height, base diameter, and tip diameter were analyzed using the finite element method, with results showing that the most influencing factor was base diameter, followed by height. Moreover, the taper angle, which is dependent on all the geometrical factors, was found to directly affect the penetration efficiency at a fixed height. An additional model was developed to relate the height and taper angle to penetration efficiency, and the results were experimentally validated by compression testing of MN array prototypes printed using two-photon photolithography. The numerical model closely predicted the experimental results, with a root mean square error of 9.35. The results of our study have the potential to aid the design of high-penetration efficiency MNs for better functionality and applicability

Mechanical properties test and microstructure analysis of polyoxymethylene (POM) micro injection moulded standard parts

The tensile mechanical properties and the micro structure of micro injection moulded polyoxymethylene (POM) test parts were investigated in this paper. The effects of different injection moulding processing conditions on ultimate tensile stress and strain at break were analyzed. Additionally, the effects of miniaturization on the mechanical properties were investigated by executing injection moulding with both a standard tool designed according to ISO 527-2 and a miniaturized test part obtained from the standard design by a downscaling factor 10. The experiments have been performed according to factorial plans, in which the factors of interest were mould temperature, melt temperature and dimensional range of the specimen (i.e. macro and micro parts). Micro structure analysis was performed by means of plastography techniques and revealed that high mould and melt temperatures resulted on a thin skin layer and a larger spherulitic core, low value of ultimate tensile stress and high of elongation at break