The Design of Effective Maintenance Outsourcing Contracts

Recent developments in maintenance planning and management demonstrate that the establishment of optimized maintenance policies may drastically improve the performance and reduce the operating cost of facilities. However maintenance activities are typically outside of the core business of production facilities, hence enterprises often fail to catch the opportunities that may originate by properly optimized management strategies. A strategic maintenance management should hence encompass the possibility of outsourcing maintenance activities to ensure the necessary perfomance of production systems, while allowing enterprises to concentrate their resources on their core activities. In order to be effectively undertaken an outsourcing strategy must be supported by a proper performance oriented contract. The present paper aims to provide an adequate methodology to address such issues and to define a framework for the definition of the relevant contract variables such as availability levels, penalty policies, rewards and service cost. The methodology here proposed is based upon the evaluation of the expected profit function of both the outsourcer and the provider, by performing a trade-off analysis on the basis of the transaction costs

Influence of bundle porosity on shell-side hydrodynamics and mass transfer in regular fiber arrays: A computational study

CFD predictions of the effects of a fiber bundle porosity on shell-side hydrodynamics and mass transfer under conditions of steady laminar flow were obtained. Fluid was assumed to flow around regular hexag-onal or square arrays of cylindrical fibers of different pitch to diameter ratios, yielding bundle porosities ranging from the theoretical minimum up to similar to 1. A large number of axial, transverse and mixed flow combinations were simulated by letting the axial and transverse flow Reynolds numbers and the trans-verse flow attack angle vary. Both fully developed and developing conditions (entrance effects) were con-sidered. The continuity and momentum equations, along with a transport equation for the concentra-tion of a high-Schmidt number solute, were solved by a finite volume CFD code. Fully developed condi-tions were simulated by the well-established "unit cell" approach, in which the computational domain is two-dimensional and includes a single fiber with the associated fluid, periodic boundary conditions are imposed between all opposite sides and compensative terms are introduced to account for large-scale longitudinal or transversal gradients. Developing flow was studied by using a fully three-dimensional computational domain. Predictions were validated against experimental, computational and analytic liter-ature results. The simulations showed that lattices with different porosities exhibit a qualitatively similar behavior, but differ significantly in important quantities such as the Darcy permeability, the Sherwood number and the hydrodynamic and mass transfer development length

Economic Benefits of Waste Pickling Solution Valorization

An integrated hybrid membrane process, composed of a diffusion dialysis (DD), a membrane distillation (MD) and a reactive precipitation unit (CSTR), is proposed as a promising solution for the valorization and onsite recycling of pickling waste streams. An economic analysis was performed aiming to demonstrate the feasibility of the developed process with a NPV of about EUR 40,000 and a DPBP of 4 years. The investment and operating costs, as well as the avoided costs and the benefits for the company operating the plant, were analyzed with an extensive cost tracking exercise and through face-to-face contact with manufacturers and sector leaders. A mathematical model was implemented using the gPROMS modelling platform. It is able to simulate steady state operations and run optimization analysis of the process performance. The impact of key operating and design parameters, such as the set-point bath concentration and the DD and MD membrane areas, respectively, was investigated and the optimal arrangement was identified. Finally, operating variables and design parameters were optimized simultaneously in a nonlinear framework as a tradeoff between profitability and environmental impact. We show how the integration of new technologies into the traditional pickling industry could provide a significant benefit for the issues of process sustainability, which are currently pressing

Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)

In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. For example, a key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process versus those that measure fl ux through the autophagy pathway (i.e., the complete process including the amount and rate of cargo sequestered and degraded). In particular, a block in macroautophagy that results in autophagosome accumulation must be differentiated from stimuli that increase autophagic activity, defi ned as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (inmost higher eukaryotes and some protists such as Dictyostelium ) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the fi eld understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. It is worth emphasizing here that lysosomal digestion is a stage of autophagy and evaluating its competence is a crucial part of the evaluation of autophagic flux, or complete autophagy. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. Along these lines, because of the potential for pleiotropic effects due to blocking autophagy through genetic manipulation it is imperative to delete or knock down more than one autophagy-related gene. In addition, some individual Atg proteins, or groups of proteins, are involved in other cellular pathways so not all Atg proteins can be used as a specific marker for an autophagic process. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field

Project Management Information Systems (PMISs): A Statistical-Based Analysis for the Evaluation of Software Packages Features

Project Managers (PMs) working in competitive markets are finding Project Management Information Systems (PMISs) useful for planning, organizing and controlling projects of varying complexity. A wide variety of PMIS software is available, suitable for projects differing in scope and user needs. This paper identifies the most useful features found in PMISs. An extensive literature review and analysis of commercial software is made to identify the main features of PMISs. Afterwards, the list is reduced by a panel of project management experts, and a statistical analysis is performed on data acquired by means of two different surveys. The relative importance of listed features is properly computed, and the interactions between the respondent’s profiles and PMIS features are also investigated by cluster and respondents’ analyses. The paper provides information for researchers and practitioners interested in PMISs packages and their applications. Furthermore, the analyses may help practitioners when choosing a PMIS, and also for developers of PMISs software in understanding user needs

Selection of a Sustainable Functional Pasta Enriched with Opuntia Using ELECTRE III Methodology

In the last decade, the nutritional and health benefits of Opuntia (Opuntia ficus-indica (L.) Mill.) were discussed by academic scientists and private companies. In particular, the introduction of this substance in frequently consumed foods, like, for example, pasta and bakery products, could have a wide diffusion due to its rich composition in polyphenols, vitamins, polyunsaturated fatty acids, and amino acids. The identified natural cactus compounds are responsible for biologically relevant activities including anti-inflammatory, antioxidant, hypoglycemic, antimicrobial, and neuro-protective properties. The aim of this paper is the evaluation of the best combination of Opuntia quantity and process parameters (recipe) for the production of sustainable functional pasta. The results obtained show that the new functional pasta guarantees the presence of the Opuntia quantity necessary to be considered a healthy food without altering the organoleptic and physical properties of the final product. An important indicator of a sustainable food product is its capacity to contribute to public health while maintaining a high quality of the final product. The selection of the optimal recipe was carried out by means of a multi-criteria decision-making procedure, ELECTRE III. Finally, a sensitivity analysis was conducted to assess the stability of the obtained solutions varying the ELECTRE III thresholds, showing that the results obtained are stable under uncertain conditions. Food productions are often affected by qualitative judgments in terms of physical and organoleptic properties of the final product, making the ELECTRE III particularly suitable in an industrial application in which different points of view are involved

Shelf life-based inventory management policy for RF monitored warehouse

Post-harvest losses of perishable products strongly depend on inefficiencies of the entire supply chain. In particular, these inefficiencies can be reduced by optimizing the warehouse management, taking into account the remaining shelf life of the product, and matching it to the requirements of the subsequent part of the handling chain. The replacement of First In First Out picking rule with Last Shelf Life First Out policy has been proved to improve the overall performance of the supply chain. The practicability of such approach is related to the possibility of monitoring the deterioration rate of the products and of predicting the residual shelf-life, that is mainly influenced by harvesting conditions. Shelf-life based inventory management policies are seldom employed, generally due to the difficulties in the assessment of the environmental conditions. Such problem can be overcome by means of an automatic system able to acquire the volatile organic compound emitted by the product and of a communication tool that allows sending the information to be processed. RF technologies can be efficiently employed to reach this purpose in order to establish a shelf-life based prediction model. The present paper reports the technical/economic analysis related to the employment of an RF warehouse management system in an agro-industrial supply chain based upon an experimental campaign performed in a real case study

Damage to Strawberries Caused by Simulated Transport

The quality and condition of perishable products delivered to the market and their subsequent selling prices are directly affected by the care taken during harvesting and handling. Mechanical injury, in fact, occurs at all stages, from pre-harvest operations through post-harvest handling, packing and transport to the market. The main implications of this damage are the reduction of the product’s quality and economical losses related to the shelf life diminution. For most perishable products, the shelf life is relatively short and it is typically dictated by microbial growth related to the application of dynamic and static loads during transportation. This paper presents the correlation between vibration levels and microbiological growth on strawberries and woodland strawberries and detects the presence of volatile organic compounds (VOC) in order to develop an intelligent logistic unit capable of monitoring VOCs using a specific sensor system. Fresh fruits were exposed to vibrations by means of a vibrating table in a temperature-controlled environment. Microbiological analyses were conducted on samples, taken at different positions along the column of the crates. The values obtained were compared with control samples not exposed to vibrations and the results show that different positions along the column influence the development of bacteria, yeasts and filamentous fungi