Search results for "CKC"

C.K.C Newsletter, special issue, spring 1982

1982

De Outreau a Mahoma: La comunicación, entre el rumor y la provocación

2006

Developing a framework for designing humanitarian blockchain projects

2021

International audience; Blockchain technology promises to improve the efficiency, transparency, and accountability of humanitarian operations. Yet at the same time, especially the humanitarian context with its characteristic volatility poses unique challenges to any technology. Most prominent are the humanitarian principles that are fundamental to humanitarian operations. These ethical principles are set to protect the most vulnerable populations. Designing blockchain projects in the humanitarian context therefore requires a systematic framework that helps humanitarians make critical choices.While some design instructions can be found for commercial applications, the humanitarian context re…

Characterization of Food Packaging Films with Blackcurrant Fruit Waste as a Source of Antioxidant and Color Sensing Intelligent Material

2021

Chitosan and pectin films were enriched with blackcurrant pomace powder (10 and 20% (w/w)), as bio-based material, to minimize food production losses and to increase the functional properties of produced films aimed at food coatings and wrappers. Water vapor permeability of active films increased up to 25%, moisture content for 27% in pectin-based ones, but water solubility was not significantly modified. Mechanical properties (tensile strength, elongation at break and Young’s modulus) were mainly decreased due to the residual insoluble particles present in blackcurrant waste. FTIR analysis showed no significant changes between the film samples. The degradation temperatures, determined by D…

Enzyme-assisted extraction of anthocyanins and other phenolic compounds from blackcurrant (Ribes nigrum L.) press cake: From processing to bioactivit…

2022

The effects of commercial enzymes (pectinases, cellulases, beta-1-3-glucanases, and pectin lyases) on the recovery of anthocyanins and polyphenols from blackcurrant press cake were studied considering two solid:solvent ratios (1:10 and 1:4 w/v). β-glucanase enabled the recovery of the highest total phenolic content – 1142 mg/100 g, and the extraction of anthocyanins was similar using all enzymes (∼400 mg/100 g). The use of cellulases and pectinases enhanced the extraction of antioxidants (DPPH − 1080 mg/100 g; CUPRAC – 3697 mg/100 g). The freeze-dried extracts presented antioxidant potential (CUPRAC, DPPH), which was associated with their biological effects in different systems: antiviral a…

Genetic basis of speed of development in Senecio vulgaris L var. vulgaris, S. vulgaris ssp. denticulatus (O.F. Muell.) P.D. Sell, and Senecio vernali…

1996

The genetic basis of differences in speed of development from germination to first bud formation was investigated in Senecio vulgaris var. vulgaris and S. vulgaris ssp. denticulatus, and also in S. vernalis sampled from Israel and Germany. In the case of S. vulgaris, F2 segregation analysis and the recovery of very late and very early lines from extreme F2 phenotypes showed that differences can be explained by a single major gene model, whereas segregation data from F2 and backcross progenies in S. vernalis are not incompatible with a digenic model of inheritance. Senecio vernalis from Israel and S. vulgaris var. vulgaris reached the different developmental stages in a substantially shorter…

A System-based View of Blockchain Governance

2023

Abstract CONTEXT Governance is crucial in achieving the success and sustainability of blockchain systems. However, blockchain governance is multi-faceted, complex, dynamic, and challenging due to its decentralized nature and automatically enforced rules and mechanisms. OBJECTIVES This study aims to advance the theory of blockchain governance and support practitioners to deepen the researchers’ and practitioners’ understanding of blockchain governance. METHODS The study is a systematic literature review of 75 articles that applies systems theory to conceptualize blockchain governance as a system and parsimoniously organize its interrelated elements into a conceptual model. RESULTS The paper …

New techs, new threats: sfide e opportunità della rivoluzione blockchain

2021

Considering the current diffusion of blockchain technology in the most different fields, ranging from public governance to economics, from contractual applications to health, the contribution addresses the issue of the legal regulation of this new technology, precisely because of its vast applications. From the comparison between the European model and the American one, the approach of the European legislator ‒ despite the delay with which the institutions have addressed the issue, seems to show, as already happened in other areas, a more 'social oriented' perspective and based on a sort of 'democratization' of data compared to the American approach, more ‘business oriented’, where the scho…

DLT, BLOCKCHAIN E SMART CONTRACT

2020

La tecnologia blockchain nasce nel 2008 con l’annuncio di BitCoin [1], una delle più diffuse criptovalute. Il ruolo fondamentale della blockchain nell’ambito delle criptovalute è quello di garantire l’impossibilità di spendere due volte lo stesso valore in transazioni successive, fattispecie che viene indicata nel mondo anglosassone come double spending. Il problema del double spending è di difficile soluzione quando l’informazione di un valore è espressa in formato digitale, il quale ben si presta alla riproduzione di copie identiche consentendo quindi di spendere quel valore più volte. Il problema è superabile in presenza di una entità centralizzata fidata, quale ad esempio una banca, ma …

Nonlinear Feedback Control and Stability Analysis of a Proof-of-Work Blockchain

2017

In this paper a novel feedback controller and stability analysis of a blockchain implementation is developed by using a control engineering perspective. The controller output equals the difficulty adjustment in the mining process while the feedback variable is the average block time over a certain time period. The computational power (hash rate) of the miners is considered a disturbance in the model. The developed controller is tested against a simulation model with constant disturbance, step and ramp responses as well as with a high-frequency sinusoidal disturbance. Stability and a fast response is demonstrated in all these cases with a controller which adjusts it's output at every new blo…