Energy inputs and crop yield relationship in greenhouse tomato production

This study examines energy use patterns and the relationship between energy inputs and yield for greenhouse tomato production in Antalya province of Turkey. The data used in this study were based on cross-sectional data collected from growers by using a face to face survey. The results revealed that diesel (34.35%), fertilizer (27.59%), electricity (16.01%), chemicals (10.19%) and human power (8.64%) consumed the bulk of energy. In the surveyed farms, average yield and energy consumption were calculated as around 160000 kg/ha and 106716.2 MJ/ha, respectively. The results also showed that output–input, specific energy and energy productivity were 1.2, 12380.3 MJ/t and 0.09 kg/MJ, respectively. The results implied that small size farms were more efficient than large ones in terms of output–input ratio. An econometric model was developed to estimate the impact of energy inputs on yield. Therefore, tomato yield, an endogenous variable was assumed to be a function of exogenous variables; fertilizer, chemicals, machinery, human, water for irrigation and seed energy. The empirical results indicated that all exogenous variables except seed energy were found statistically significant and contributed to yield. Among all statistically significant exogenous variables, human, fertilizer, water, chemicals and machinery were ranked in terms of elasticities. These results indicate that the Turkish greenhouse industry heavily depends on fossil fuels.     

Long-term adrenalectomy decreases NMDA receptors in rat hippocampus

The effect of long-term adrenalectomy on NMDA receptors in the rat hippocampus was studied. Hippocampal sections of control and adrenalectomized rats were incubated with [3H]MK-801, a radiolabeled non-competitive inhibitor of the NMDA receptor. Analysis by in vitro autoradiography showed a significant decrease in [3H]MK-801 binding in the dentate gyrus, CA1 and CA4 areas, as well as the temporal cortex. Results of this study suggest that glucocorticoids are vital for the regulation of the NMDA receptors.     

Power efficiency of user cooperation in multihop wireless networks

In this paper we analyze the power efficiency of a user cooperation scheme for multihop wireless networks. In this scheme, the signals are jointly transmitted by two mobile terminals (MTs), emulating transmit macro diversity. We derive the optimal transmit power assignments for the two transmitting MTs and quantify the power efficiency of the scheme. The results indicate that macro diversity by way of user cooperation can substantially reduce the total consumed power in multihop wireless networks for wide range of topologies of MTs and their distances.     

Mitigating jamming attacks in mobile cognitive networks through time hopping

5G wireless networks will support massive connectivity mainly due to device‐to‐device communications. An enabling technology for device‐to‐device links is the dynamical spectrum access. The devices, which are equipped with cognitive radios, are to be allowed to reuse spectrum occupied by cellular links. The dynamical spectrum availability makes cognitive users switch between channels. Switching leads to energy consumption, latency, and communication overhead in general. The performance degrades even more when the network is under jamming attack. This type of attack is one of the most detrimental attacks. Addressing jamming while maintaining a desired quality of service is a challenge. While existing anti‐jamming mechanisms assume stationary users, in this paper, we propose and evaluate countermeasures for mobile cognitive users. We propose two time‐based techniques, which, unlike other existing frequency‐based techniques, do not assume accessibility to multiple channels and hence do not rely on switching to countermeasure jamming. We achieve analytical solutions of jamming, switching, and error probabilities. Based on our findings, the proposed techniques out perform other existing frequency‐based techniques. Copyright © 2016 John Wiley & Sons, Ltd.     

Restructuring of Turkey’s electricity market and the share of hydropower energy: The case of the Eastern Black Sea Basin

This paper presents the historical development of Turkey’s electricity power sector, the efforts for introducing competition in the power industry in Turkey, and the concerns regarding restructuring in Turkey. The contribution of the hydropower energy potential in Turkey to the reconstruction of the electricity structure in Turkey is also investigated. Then, among the 25 hydrological basins in Turkey, the Eastern Black Sea Basin located in the northeast of Turkey, which has great advantages from the view point of small hydropower potential or hydropower potential without storage, is chosen as the case study to carry out some investigations concerning its potential and to analyze the contribution of the private sector (the corporate body) in regard to the development of hydro potential in this basin within the scope of the 4628 Electricity Market Law. With this law, concerning the restructuring of the electricity market, private sector investments in this segment have increased. In total, 1524 hydroelectric power projects with 22 360 MW installed capacity has been implemented until January 22nd, 2009 and this figure is continuously rising.     

Improvement of the Neutronic Performance of the PACER Fusion Concept Using Thorium Molten Salt with Reactor Grade Plutonium

In this study, the improvement of neutronic performance of a dual purpose modified PACER concept has been investigated. Flibe as the main constituent are fixed as 92% coolant. ThF₄ is mixed with increased mole-fractions of RG-PuF₄ starting by 0 mol % up to 1 mol %. TBR variations for all the investigated salts with respect to the RG-PuF₄ contents are computed. Tritium self-sufficiency is provided with the ThF₄ when the adding RG-PuF₄ content is higher than 0.75%. The energy multiplication of the blanket is increased as 70% with adding RG-PuF₄ contents to ThF₄. High quality fissile isotope ²³³U are produced with increasing RG-PuF₄. DPA and helium production increases with increased RG-PuF₄ content in molten salt. Radiation damage with dpa <1.7 and He <3.3 ppm after a plant operation period of 30 years will be well below the damage limit values.     

Modeling and forecasting of Turkey’s energy consumption using socio-economic and demographic variables

This study deals with the modeling of the energy consumption in Turkey in order to forecast future projections based on socio-economic and demographic variables (gross domestic product-GDP, population, import and export amounts, and employment) using artificial neural network (ANN) and regression analyses. For this purpose, four diverse models including different indicators were used in the analyses. As the result of the analyses, this research proposes Model 2 as a suitable ANN model (having four independent variables being GDP, population, the amount of import and export) to efficiently estimate the energy consumption for Turkey. The proposed model predicted the energy consumption better than the regression models and the other three ANN models. Thus, the future energy consumption of Turkey is calculated by means of this model under different scenarios. The predicted forecast results by ANN were compared with the official forecasts. Finally, it was concluded that all the scenarios that were analyzed gave lower estimates of the energy consumption than the MENR projections and these scenarios also showed that the future energy consumption of Turkey would vary between 117.0 and 175.4 Mtoe in 2014.     

Mechanical and dry sliding wear properties of silicon carbide particulate reinforced aluminium–copper alloy matrix composites produced by direct squeeze casting method

In this study, the microstructural features, mechanical properties and dry sliding wear characteristics of Al–4.5Cu–3Mg/15 vol.% SiCp matrix composites, manufactured by squeeze casting technique, were investigated. Wear tests were carried out at 0.5, 1 and 2.0 m/s sliding speeds under the loads of 5, 10, and 15 N for a 1000 m sliding distance versus AISI D2 steel disc. The results showed that, the composites have homogeneously distributed porosity free SiC particles. The failure in composites occurs in both matrix and particles simultaneously implying good bonding between matrix and particles. Friction coefficient of the composites decreased with an increase in the applied load and the sliding speed. In addition, the higher the applied load and the faster the sliding speed are, the higher the wear rate is. SEM analysis indicated that worn surfaces consisted of plastically deformed and oxidized particles removed by the micro-machining effects of the reinforcement phase.