Search results for "lcsh:Chemical engineering"
showing 10 items of 107 documents
A Brief Review on the Resistance-in-Series Model in Membrane Bioreactors (MBRs)
2019
The cake layer deposited on the membrane modules of membrane bioreactors (MBRs), especially under a submerged configuration, represents a relevant and fundamental mechanism deeply influencing the development of membrane fouling. It negatively affects the total resistance to filtration, while exerting a positive effect as a “pre-filter„ promoting the “dynamic membrane„ that protects the physical membrane from internal fouling. These two opposite phenomena should be properly managed, where the submerged membranes are usually subjected to a periodical cake layer removal through ordinary (permeate backwashing and air scouring) and/or irregular cleaning actions (manual ph…
Light Scattering as an Easy Tool to Measure Vesicles Weight Concentration
2020
Over the last few decades, liposomes have emerged as promising drug delivery systems and effective membrane models for studying biophysical and biological processes. For all applications, knowing their concentration after preparation is crucial. Thus, the development of methods for easily controlling vesicles concentration would be of great utility. A new assay is presented here, based on a suitable analysis of light scattering intensity from liposome dispersions. The method, tested for extrusion preparations, is precise, easy, fast, non-destructive and uses a tiny amount of sample. Furthermore, the scattering intensity can be measured indifferently at different angles, or even by using the…
ADVANCED STATISTICAL ANALYSIS OF LOCAL BUBBLE SIZE DISTRIBUTIONS IN 2D GAS FLUIDIZED BEDS
2009
The principal difficulty in analysing fluidization quality and bubble dynamics is related to the possibility of measuring or predicting the physical and geometrical properties of gas bubbles rising in a granular medium. Even the development of detailed experimental correlations gives poor results, being necessary a fully statistical approach. On the above basis, the present work focuses on the statistical analysis of the behaviour of a 2-D fluidized bed operating under bubbling and slugging conditions, performing measurements of Local Bubble Size Distributions (BSD) along the bed. The analysis allowed to observe a characteristic bimodal shape of BSDs for different particles dimension and fl…
Case Studies of Macro-and Microplastics Pollution in Coastal Waters and Rivers: Is There a Solution With New Removal Technologies and Policy Actions?.
2020
This opinion paper on microplastics pollution has selected different aspects and case studies of micro and macro-plastic litter pollution in coastal waters, and rivers. We point out a discussion on this topic and ask ourselves if there is a solution to the global problem by developing new microplastics removal technologies as well as policy actions. The first two case studies are related with macroplastics marine litter in beaches, a third report describes a new simple sampling device for microplastics in coastal and nearshore areas, five case study assess microplastics pollution in worldwide coastal environments, sediments and catchments (India, Mexico, Australia, Europe and the Nordic Sea…
Case Study of Potential Production of Renewable Energy Sources (RES) from Livestock Wastes in Mediterranean Islands
2017
The aim of this work is to evaluate the potential production of Renewable Energy Sources (RES) from livestock wastes that are commonly found on Mediterranean islands, by using the island of Malta as a case study. Organic wastes in the form of livestock manure and slurry, as well as other by-products originating from the food transformation industry in the making of alcoholic beverages and the processing of olives, tomatoes and other streams, if mixed in such a way to achieve a correct C/N ratio, can be subjected to anaerobic co-digestion for the production of biogas and digestate. Biogas can be further transformed into biomethane, a fuel that can be used to power surface transportation and …
Pressure Retarded Osmosis: a Membrane Process for Environmental Sustainability
2016
Salinity Gradient Power (SGP) based on the controlled mixing between two solutions at different salinities is a viable alternative to produce power from renewable sources. Pressure Retarded Osmosis (PRO) is one of the most promising technologies proposed so far for the exploitation of such energy source. Apart from the typical source of salinity gradients, namely river water and seawater, more and more interest has been raised recently towards the use of non-conventional saline solutions. In this work, water originating from a sewage treatment plant is used as the dilute solution (feed solution), while brine exiting from a desalination plant is used as the concentrate (draw solution), thus …
Effects of Rapid Refrigeration and Modified Atmosphere Packaging on Litchi (Litchi chinensis Sonn.) Fruit Quality Traits
2017
Litchi (Litchi chinensis Sonn.) is a tropical fruit characterized by a rapid pericarp browning and dehydration during postharvest, resulting in an accelerated shelf life and in a loss of consumer appreciation and consequently of its market value. The aim of our study was to assess litchi fruit chemical-physical and sensory quality changes during postharvest and shelf life using rapid refrigeration (RR) and active modified atmosphere packaging (MAP). Litchi fruits were picked at commercial harvest and were divided in 4 groups: not treated fruit (CTR); rapid refrigerated fruit (RRF); modified atmosphere packed fruit (MAP); hydrogen peroxide treated and modified atmosphere packed fruit (MAP+).…
Consumer Assessment on Sensory Attributes of Fresh Table Grapes Cv 'Italia' and 'Red Globe' after Long Cold Storage Treatment
2017
The impact of research that is being carried out into the relationship between food and consumers is progressively reinforced by continuous findings in literature confirming that consumers choose foods basing on their functional cognition and sensory perception, especially when buying fruit and vegetables. Therefore, it is important for table grape producers to be aware of consumers' concerns and preferences both, during the purchasing stage and after, during consumption at home, when experiential attributes have more importance. In both cases, sensory attributes play an important role in determining consumers’ purchase behavior of table grape. Table grapes cv ‘Italia’ and ‘Red Globe’ are p…
High quality extra virgin olive oil from olives attacked by the olive fruit fly, Bactrocera oleae (Rossi) (Diptera Tephritidae): which is the tolerab…
2017
The infestation due to the olive fruit fly, Bactrocera oleae (Rossi), the key pest in most of world olive groves, has been monitored in six years, from 2004 to 2008 and in 2014, in eight coastal Sicilian olive groves consisting of ‘Cerasuola’ and ‘Nocellara del Belice’ cultivars. Infestation was recorded following the classical sampling method based on olive collection and dissection, in order to count live olive fruit fly instars (eggs, larvae and pupae) and exit holes. Four different infestation indexes, all of them calculated using data recorded at harvest, have been used to assess their relationship with the main three quality parameters of the olive oil obtained from the same olive sam…
Quality Changes of Tropical and Subtropical Fresh-Cut Fruits Mix in Modified Atmosphere Packaging
2017
Application of passive modified atmosphere packaging (MAP) for shelf life extension of mixed pineapple slices, mango pieces and orange segments, was evaluated. Fruits of Ananas cv ‘Gold’, Mango cv ‘Keitt’ and Orange cv ‘Washington Navel’ were washed, sanitized, peeled and cut. Minimal processed fruits were packed under 2 different atmospheres, passive (air) and active MAP (70% N2, 10 %O2, 20 %CO2), and stored at 10±1 °C with 85±5% RH for 12 days. Changes in package atmosphere composition, weight loss, color, texture, pH, soluble solids, sensory attributes, were evaluated after cutting and at three subsequent stages of storage (the 3 day, 6d, 9d, and the 12 day). Color parameters L* and b* s…