Shocks in economic growth = shocking effects for food security?

The recent economic and financial turmoil raises the question on how global economic growth affects agricultural commodity markets and, hence, food security. To address this question, this paper assesses the potential impacts of faster economic growth in developed and emerging economies on the one hand and a replication of the recent economic downturn on the other hand. The empirical analysis uses AGLINK-COSIMO, a recursive-dynamic, partial equilibrium, supply–demand model. Simulation results demonstrate that higher economic growth influences demand more than supply, resulting in higher world market prices for agricultural commodities. Emerging economies tend to import more and to stock less in order to cover their demand needs, while the rest of the world increases its exports. The modelled faster economic growth also helps developing countries to improve their trade balance, but does not necessarily give them the incentive to address domestic food security concerns by boosting domestic consumption. A replication of an economic downturn leads to lower world prices, and while the magnitude of the effects decreases over time, markets do not regain their baseline levels within a 5-year period. Due to the lower world market prices, developing countries import more and increase their per capita food calorie intake. However, as developing countries become more import dependent, this also implies that they become more vulnerable to disruptions in agricultural world markets.     

Compressive and cyclic flexural response of double-hooked-end steel fiber reinforced concrete

Recent developments on high-performance double-hooked-end steel fibers have enhanced the wide applications of steel fiber reinforced concrete (SFRC). This study presents the compressive properties and the cyclic flexural performance of the SFRC that were experimentally examined. Three different double-hooked-end steel fibers at 0.25%, 0.5%, 0.75%, and 1% volume fractions were considered. All fiber types had similar length to diameter ratios, while the first two fiber types had similar anchorage mechanisms (4D) and tensile strength and the third type had different anchorage mechanism (5D) and a higher tensile strength. The increased volumetric ratio of the fibers increased the post-peak compressive strain (ductility), the tensile strength, and the cyclic flexural strength and cumulative energy dissipation characteristics of the SFRC. Among the 4D fibers, the mixtures with the larger steel fibers showed higher flexural strength and more energy dissipation compared to the SFRCs with smaller size fibers. For 1% steel fiber dosage, 4D and 5D specimens showed similar cyclic flexural responses. Finally, a 3D finite element model that can predict the monotonic and cyclic flexural responses of the double-hooked-end SFRC was developed. The calibration process considered the results obtained from the inverse analysis to determine the tensile behavior of the SFRC.     

A proposed enhanced scheme for the dynamic frequency hopping performance in the IEEE 802.22 standard

This paper presents an integrated scheme for the dynamic‐frequency‐hopping (DFH) technique provided in literature for the IEEE 802.22 standard supporting wireless regional area networks (WRANs). The performance of DFH is analyzed thoroughly for various channel models and for a multiple‐input multiple‐output systems. The core of this research is based on the coexistence of digital terrestrial TV broadcasting and the WRANs in the TV white space. The proposed technique aims at protecting the incumbent users from interfering with the cognitive broadband access in the TV spectrum. In order to achieve this, spectrum sensing is performed in the intended working channel in DFH while spectrum monitoring with an energy‐ratio (ER) algorithm is applied during the WRAN data transmission in the working channel. Hence, in the DFH‐ER algorithm, the reappearance of a digital terrestrial TV signal in a band occupied by the WRANs would be detected immediately. This will provide interference free performance for the licensed signal as well as reliable data transmission for the unlicensed ones. Both analyses and simulation results of the proposed DFH‐ER technique compared with the conventional DFH scenario exemplify the enhancement of the WRAN data transmission while protecting the digital terrestrial TV users. Copyright © 2016 John Wiley & Sons, Ltd.     

Decentralised Functional Signatures

Mobile Networks and Applications - With the rapid development of the Internet of Things (IoT) a lot of critical information is shared however without having guarantees about the origin and...     

Study of organic acids, volatile fraction and caseins of a new Halloumi-type cheese during ripening in whey brine

Organic acids, fat hydrolysis, volatile compounds and sensory characteristics of a new brine cheese which combines characteristics of Halloumi and Feta cheeses during its ripening in whey brine (100g NaCl L⁻¹) were studied. Thermotolerant protease of Mucor miehei as a coagulant enzyme and a mixture of thermotolerant starter cultures Enterococcus faecium 0165 (0.5% w/w) and Lactobacillus casei 80 10D were used. Good quality new Halloumi-type cheese was produced with higher proteolysis than traditional Halloumi cheese kept in whey brine. The volatile compounds identified comprised alcohols, aldehydes, ketones, acids, esters, hydrocarbons and sulphur compounds. Ethanol was the dominant volatile compound determined. Lactic acid was the dominant acid produced; its concentration increased during ripening, reaching a maximum value of 9929 mg kg⁻¹ at day 30. Acetic acid was also found in high amounts, which increased during cheese ripening. Lipolysis of cheese was not intense. The most abundant acids of the mature cheese were palmitic, oleic and acetic acid. The Halloumi-type cheese scored higher in the sensory analysis when fresh than did the mature cheese.     

LC–DAD–MS (ESI+) analysis of the phenolic content of Sorbus domestica fruits in relation to their maturity stage

The aim of this study was the detailed qualitative and quantitative analysis of the phenolic content of several extracts and fractions of Sorbus domestica fruits. The analysis was realized by LC–DAD–MS (ESI+). Twenty-four different extracts and fractions of five different maturity stages of the fruit were analyzed for comparison reasons in order to determine the most beneficial for health type of consuming. Sixty-two different phenolics were identified. There were significant qualitative and quantitative differentiations in the phenolic content among the different types of the fruits. All categories were rich in benzoic, phenylpropanoic and cinnamoylquinic acids and derivatives. Unripe fruit categories were also rich in flavonoids, while well matured fruit categories had a low content of flavonoids. Fruit pulp, which was proved to be a strong antioxidant according to previous research work, contained very low amounts of both acids and flavonoids, but its phenolic content was highly qualitatively differentiated from the other categories.     

Theoretical and experimental analysis of the thermal behaviour of a green roof system installed in two residential buildings in Athens,Greece

Measurements of the thermal behaviour of two residential buildings equipped with a green roof system have been performed in Athens, Greece. Experimental data have been used to calibrate detailed simulation tools and the specific energy and environmental performance of the planted roofs system has been estimated in detail. Simulations have been performed for free‐floating and thermostatically controlled conditions. The expected energy benefits as well as the possible improvements of the indoor thermal comfort have been assessed. It is found that green roofs have a limited contribution to the heating demand of insulated buildings operating under the Mediterranean climate. On the contrary, the green roof system is found to contribute highly to reduce the cooling load of thermostatically controlled buildings. For the considered residential buildings, a cooling load decrease of about 11% has been calculated. In parallel, it is found that green roofs contribute to improve thermal comfort in free‐floating buildings during the summer period. The expected maximum decrease of the indoor air and roof surface temperatures is close to 0.6°C. Such a decrease contributes to reduce by 0.1 the summer absolute Predicted Mean Vote Comfort Index levels in the building. Copyright © 2009 John Wiley & Sons, Ltd.     

Dissolved and particulate trace metal levels in the Saronikos Gulf, Greece, in 2004. The impact of the primary Wastewater Treatment Plant of Psittalia

The present study examines the concentrations of Cd, Cu, Mn, Ni, Pb and Zn in 2004 in the Saronikos Gulf, an embayment affected by anthropogenic inputs from the nearby metropolitan area of Athens. We investigated in particular the impact of the operation for a decade of the primary Wastewater Treatment Plant of Athens, which is located at Psittalia Island, on the levels of these metals in the marine environment of the gulf, few months before the inauguration of the secondary treatment. Therefore, the present work represents the needed baseline for any future comparisons and assessment of the impact of the secondary treatment. For two samplings carried out in May and September 2004 in a grid of fifteen stations, dissolved and particulate metal concentrations are, respectively, in the range 5.0–63 and 0.22–3.6 ng/L for Cd, 0.03–0.72 and 0.03–0.23 μg/L for Cu, 0.11–1.2 and 0.02–0.55 μg/L for Mn, 0.19–1.5 and 0.01–0.11 μg/L for Ni, 0.05–0.60 and 0.02–0.59 μg/L for Pb and 0.13–5.8 and 0.06–1.0 μg/L for Zn. The concentrations of the majority of the studied metals obtained in 2004 are comparable to those of the year 2000 and among the lowest detected in the Saronikos Gulf ever since the beginning of the MED-POL program twenty years ago. This stabilization is attributed to the operation of the wastewater treatment plant and offers an indication that the levels of trace metal pollution of the marine environment of the gulf are possibly reaching a steady state.