Assessing the carbon footprint across the supply chain: Cow milk vs soy drink.

Since livestock product consumption could have a significant effect on tackling climate change, in the few last years, there has been an increasing consumer demand for non-dairy alternatives. Despite plant-based beverages being considered crucial to foster the transition towards sustainable diet models, no studies have yet compared the level of emissions of plant-based beverages with animal-based ones. The present study aims at computing the carbon footprint of cow milk and that of soy drink and evaluating the carbon footprint results in the light of the substitutability of cow's milk with soy drink, analyzing the potential environmental, economic and nutritional trade-offs between the two products. Results highlight that, considering the environmental perspective, soy drink could be a valid substitute of cow milk: its production has a lower carbon footprint, allowing for the achievement of food security objectives. However, focusing on the economic and nutritional perspectives, the high average consumer price of soy drink is associated with an overall lower nutritional level. In order to reach the same nutritional value as 1 L of cow milk in terms of protein intake, the consumption of soy drink should be increased by 13%. Furthermore, soy drink consumption implies paying 66% more than for cow milk, when considering the same protein content.

Photoelectron emission from yttrium thin films prepared by pulsed laser deposition.

We present the results of our investigation of metallic films as suitable materials for the production of intense electron beams. Thin films of Y prepared for the first time by pulsed laser deposition on Si substrates have been tested as photocathodes in an ultra high vacuum photodiode chamber at 10(-6) Pa. High quantum efficiencies have been obtained for the deposited films, comparable to those of corresponding bulks. The role of the adsorbed gases on the emission performance has been studied. Systematic laser cleaning treatments improved the quantum efficiency (QE) from 10(-6) to 4.5 10(-4). The samples could stay for several months in open air before being tested in a photodiode cell. The deposition process and testing results are presented.