N.Georgescu-Roegen's production model for EROI evaluation. Case study: Electrolytic H2 production using solar energy

Nowadays there is a considerable interest in studying the direct and indirect energies involved in products and services. This is particularly critical when novel energy resources are exploited by complex technological chains and to determine if they can indeed guarantee an useful energy societal supply. Unfortunately, there is no universally accepted procedure for doing this. The present paper aims to suggest a new procedure to evaluate the EROI of technologies producing energy carriers based on the stocks/flows-funds/services production model of N.G. Roegen. The suggested method can uniquely identify the energy flows involved in the technology consistent with biophysical and anthropological boundaries. This analytical formulation can be used either for single technologies or combination of them in series or parallel using different energy resources. Specific recommendations in the use of the Cumulative Energy Demand and Global Energy Requirements in the Net Energy Analysis, as well as in the evaluation of both for an electrical system are reported. The approach is here applied to the analysis of electrolytic H2 production using electricity produced by a photovoltaic panel ("green hydrogen"). The resulting EROI = 0.97 means that the technology is not sustainable, requiring 3% energy from the anthropological sphere to support it. The paper is organized as follows: providing a narrative model for EROI evaluation consistent with anthropological and biophysical spheres; covering the definition of stocks/flows-funds/services model for EROI evaluation; analysing and suggesting uses of the model for energy technologies scoring and selection based on sustainability and presenting a numerical case study

Social media exploration for understanding food product attributes perception: the case of coffee and health with Twitter data

Purpose: Food companies and consumers are increasingly interested in healthy food and beverages. Coffee is one of the most commonly consumed beverages worldwide. There is increasing consensus that coffee consumption can have beneficial effects on human body. This paper aims at exploring Twitter messages' content and sentiment towards health attributes of coffee. Design/methodology/approach: The research adopted a utilitarian and hedonic consumer behaviour perspective to analyse online community messages. A sample of 13,000 tweets, from around 4,800 users, that mentions keywords coffee and health was collected on a daily basis for a month in mid-2017. The tweets were categorized with a term frequency analysis, keyword-in-context analysis and sentiment analysis. Findings: Results showed that the majority of tweets are neutral or slightly positive towards coffee’s effects on health. Media and consumers are dynamic Twitter users. Findings support that coffee consumption brings favourable emotions, wellness, energy, positive state of mind and an enjoyable and trendy lifestyle. Many tweets have a positive perception of coffee health benefits, especially relating to mental and physical well-being. Research limitations/implications: The high number of users and tweets analysed compensates the limited amount of time of data collection, Twitter messages' restricted number of characters and quantitative software analysis limitations. Practical implications: The research provides valuable suggestions for food and beverage industry managers. Originality/value: This work adds value to the literature by expanding scholars' research on food product attributes perception analysis by using social media as a source of information. Moreover, it provides valuable information on marketable coffee attributes

Tyrosine kinase inhibitors for the therapy of anaplastic thyroid cancer

Anaplastic thyroid cancer (ATC) is often incurable so new therapeutic approaches are needed. Tyrosine kinases inhibitors (such as imanitib, sunitinib or sorafenib) are under evaluation for the treatment of ATC. Other vascular disrupting agents, such as combretastatin A4 phosphate, and antiangiogenic agents, such as aplidin, PTK787/ZK222584 and human VEGF monoclonal antibodies (bevacizumab, cetuximab), have been evaluated. Small-molecule adenosine triphosphate competitive inhibitors directed intracellularly at EGFRs tyrosine kinase, such as erlotinib or gefitinib, are also studied. Furthermore, new molecules have been shown to be active against ATC, such as CLM94 and CLM3. However, more research is needed to finally identify therapies able to control and to cure this disease

Towards the Assessment of an Ecological Index for Quantifying Sustainability of Day Life. A Case Study of the Environmental Consequences of Dietary and Transport in a Standard Workday

e-Conferenc

Why the lowest Landau level approximation works in strongly type II superconductors

Higher than the lowest Landau level contributions to magnetization and specific heat of superconductors are calculated using Ginzburg - Landau equations approach. Corrections to the excitation spectrum around solution of these equations (treated perturbatively) are found. Due to symmetries of the problem leading to numerous cancellations the range of validity of the LLL approximation in mean field is much wider then a naive range and extends all the way down to $H = {H_{c2}(T)}/13$. Moreover the contribution of higher Landau levels is significantly smaller compared to LLL than expected naively. We show that like the LLL part the lattice excitation spectrum at small quasimomenta is softer than that of usual acoustic phonons. This enhanses the effect of fluctuations. The mean field calculation extends to third order, while the fluctuation contribution due to HLL is to one loop. This complements the earlier calculation of the LLL part to two loop order.Comment: 20 pages, Latex file, three figure

Hong-Ou-Mandel interference between independent III-V on silicon waveguide integrated lasers

The versatility of silicon photonic integrated circuits has led to a widespread usage of this platform for quantum information based applications, including Quantum Key Distribution (QKD). However, the integration of simple high repetition rate photon sources is yet to be achieved. The use of weak-coherent pulses (WCPs) could represent a viable solution. For example, Measurement Device Independent QKD (MDI-QKD) envisions the use of WCPs to distill a secret key immune to detector side channel attacks at large distances. Thus, the integration of III-V lasers on silicon waveguides is an interesting prospect for quantum photonics. Here, we report the experimental observation of Hong-Ou-Mandel interference with 46\pm 2% visibility between WCPs generated by two independent III-V on silicon waveguide integrated lasers. This quantum interference effect is at the heart of many applications, including MDI-QKD. Our work represents a substantial first step towards an implementation of MDI-QKD fully integrated in silicon, and could be beneficial for other applications such as standard QKD and novel quantum communication protocols.Comment: 5 pages, 3 figure

Continuous two-step anaerobic digestion (TSAD) of organic market waste: rationalising process parameters

Experimental tests on continuous two-stage anaerobic digestion (TSAD) were conducted, to assess its energetic performance, using organic market waste as a substrate. The systems were tested to ascertain the effects of external stressors, which allow the separation into two different microorganism consortia, that is, hydrogen-producing bacteria and hydrogen-consuming bacteria, to be maintained. Two bioreactors were run in series under different operational conditions, including pH, mixing rate, and initial inoculum, and three different decreasing hydraulic retention times were considered, with a fixed ratio of 1:10 in volume between the first bioreactor (hydrogen) and the second one (methane). The performance of the whole system was assessed over > 140 days to monitor the stability of the process, in terms of the reduction of the volatile solids and the energy productivity for each step. Each tested condition was scored using two parameters: efficiency and efficacy. The first corresponds to the fraction of recovered energy of the available (η) and the second (ξ) was used to compare the energy produced by the TSAD with that of one-step anaerobic digestion. The efficiency resulted to be (24–32)%, while the efficacy proved to be around 1.20. The share of energy, under the form of hydrogen, compared to the total energy recovery, was in the (8–12) % range. Finally, the oscillation behaviour of the quasi-steady-state condition was analysed in terms of the Fano factor to establish the most stable conditions