Search results for " ingegneria"
showing 10 items of 796 documents
Greenhouse gas emissions from membrane bioreactors: analysis of a two-year survey on MBRs
2017
The study aims at evaluating the nitrous oxide (N2O) emission from membrane bioreactors (MBRs) for wastewater treatment. With this regards two-years of experimental activities were performed. More specifically, the study investigates the N2O emissions considering multiple influential factors: i. configurations (i.e., sequential batch- SB-MBR; pre-denitrification - DN-MBR; University Cape Town, UCT-MBR and UCT moving bed biofilm reactor, UCT-MB-MBR); ii. wastewater composition (municipal or industrial); iii. Plant operational conditions (i.e., sludge retention time, SRT, carbon-to-nitrogen ratio, C/N, hydraulic retention time, HRT); iv. and membrane modules. Among the overall analysed config…
Removal of carbon and nutrients from wastewater in a moving bed membrane biofilm reactor: the influence of the sludge retention time
2016
A University of Cape Town (UCT) pilot plant combining both membrane bioreactor (MBR) and moving bed biofilm reactor (MBBR) technology was monitored. Three experimental Phases were carried out by varying the mixed liquor sludge retention time (SRT) (indefinite, 30 and 15 days, respectively). The system performance has been investigated during experiments in terms of: organic carbon, nitrogen and phosphorus removal, biokinetic/stoichiometric constants, membrane fouling tendency and sludge dewaterability. The observed results showed that by decreasing the SRT the UCT pilot plant was able to maintain very high total COD removal efficiencies, whilst the biological COD removal efficiency showed a…
High salinity slops treatment through a biofilm-MBR inoculated with halophilic bacteria
2010
Oily wastewater generated, in amounts of millions of tons per year, by ships mainly in engine-rooms (bilge waters) and by washing oil tanks (slops) create a major disposal problem throughout the world because of the persistence and accumulation of xenobiotic compounds in the environment. The high salinity levels (up to 25.000 p.p.m.) and the pollutants concentration limit the chances of discharge into the sewer systems and address the disposal to the sea. This situation severely lowers the discharge limits for most of the “sensible” parameters, such both COD and hydrocarbons. Slops are usually treated by ASP with pretreatment of oil/water separation. There are limited investigations on the …
Improving Of The Productivity And The Quality Of A Manufacturing Robotized Cell For Mig/Mag Welding
2007
During the last years, globalization and the necessity to reduce production costs have pushed industry to employ more and more manufacturing robotized cells. This trend has been assimilated by arc welding too. The use of robotic systems allows to increase the performance of productive systems by means of reduction in lead-time, reproducibility of processes and increase in quality. However, process automation needs pre-scheduling of manufacturing cell movements and also a setup of different welding parameters, such as power provided by the welding generator, arc length and robot speed, all of which allows to get a joint without defects. An online scheduling of robotic systems brings certainl…
Networking strategy for competitive advantage
2011
This paper explores the potential of networking strategy as a source of competitive advantage by integrating market- based and resource-based logics. It contributes to operations management literature by considering not just supply chain structures but also others kinds of network that can emerge from horizontal agreements (i.e. alliances, partnerships, joint ventures, etc.). The paper reviews the literature and develops propositions regarding how make/buy/make together decisions, governance mechanisms and network-base structures allow firms both to pursue operations performance objectives and obtain/create valuable resources. A case study supports the propositions and shows a practical app…
Functional Activation of Osteoclast Commitment in Chronic Lymphocytic Leukaemia: A Possible Role for RANK/RANKL Pathway
2017
AbstractSkeletal erosion has been found to represent an independent prognostic indicator in patients with advanced stages of chronic lymphocytic leukaemia (CLL). Whether this phenomenon also occurs in early CLL phases and its underlying mechanisms have yet to be fully elucidated. In this study, we prospectively enrolled 36 consecutive treatment-naïve patients to analyse skeletal structure and bone marrow distribution using a computational approach to PET/CT images. This evaluation was combined with the analysis of RANK/RANKL loop activation in the leukemic clone, given recent reports on its role in CLL progression. Bone erosion was particularly evident in long bone shafts, progressively inc…
Human nasoseptal chondrocytes maintain their differentiated phenotype on PLLA scaffolds produced by thermally induced phase separation and supplement…
2018
Damage of hyaline cartilage such as nasoseptal cartilage requires proper reconstruction, which remains challenging due to its low intrinsic repair capacity. Implantation of autologous chondrocytes in combination with a biomimetic biomaterial represents a promising strategy to support cartilage repair. Despite so far mostly tested for bone tissue engineering, bioactive glass (BG) could exert stimulatory effects on chondrogenesis. The aim of this work was to produce and characterize composite porous poly(L-lactide) (PLLA)/1393BG scaffolds via thermally induced phase separation (TIPS) technique and assess their effects on chondrogenesis of nasoseptal chondrocytes. The PLLA scaffolds without or…
Heterogeneous photocatalytic aqueous succinic acid formation from maleic acid reduction
2022
This study reports the anaerobic reduction of maleic acid to succinic acid in aqueous dispersion of different TiO2 based photocatalysts. Some home prepared and commercial solids containing different polymorphic phases of TiO2 and loaded with Pt and Ru were compared at different acidic pHs. The aim of the work was to verify the feasibility of the process and to determine the best samples and the optimal experimental conditions of the reaction. The best selectivity towards succinic acid was 23.2 % at 70 % of maleic acid conversion. Fumaric acid was also formed as another high added value compound, and its quantity was related to the experimental conditions and the photocatalyst used.
How does brand-related user-generated content differ across social media? Evidence reloaded
2019
Abstract In light of the relevant changes in the social media environment in recent years, this paper extends the theoretical framework of user-generated content (UGC) dimensions and updates evidence on how brand-related UGC characteristics vary across social media. Using content analysis and statistical analysis of frequencies, we compare how different social media (Facebook, Twitter, and YouTube) shape twelve important UGC dimensions. Our findings suggest that, by flattening the differences on visual and richer content, the recent trends have made Facebook and Twitter more similar to YouTube on certain brand-related UGC dimensions (e.g., self-presentation, brand centrality, brand recommen…
Generic Advertising, Brand Advertising and Price Competition: An Analysis of Free-Riding Effects and Coordination Mechanisms
2010
The main purpose of generic advertising is to enlarge the total market demand rather than capturing further slices from competitors. Several studies point out emergence of free-riding behavior under independent contribution and suggest use of coordination mechanism. However, existing literature does not shed light on the conditions under which generic advertising can be detrimental (beneficial) to stronger firms weakening (strengthening) their competitive advantage. Also, under a setting including both price and brand advertising competition, coordination in generic advertising has not been unraveled. In order to deal with such issues, we consider a one-stage duopoly game in which two firms…