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Abstract Hydro transport is characterized by the combined movement of liquid and solid particles, which in a mixture form two-phase or multiphase flows with different physical and mechanical properties. One of the main tasks of hydraulic transport is to study the throughput of pipelines, where taking into account the distribution of sediment concentration over the cross section of the pipeline formed under the influence of gravitational force is of great importance in describing the nature of the two-phase flow. Pressure-bearing suspended flows in hydro transport systems are usually characterized by high volumetric concentrations and a wide range of sizes and densities of solid particles that are part of hydraulic mixtures. The flows under consideration are more complex in their structure than turbulent flows of homogeneous liquids in pipes. Therefore, the methods for calculating these flows are much more complicated than the usual methods of hydraulics of pressure flows of homogeneous liquids. To develop scientif-ically based methods for calculating the parameters of the movement of hydraulic mixtures in pipes, widely used the averaged equations of the weighted flow and experimental data. When moving slurries through pipes, gravity plays a significant role. The article discusses the influence of gravity on the throughput of pressure systems with different slopes and obtains new dependences of the flow rate of turbid flow on the slope of the pressure pipe.

This paper is concerned with the risk management practices of an electricity retailer motivated by the Dutch electricity market. We examine the effectiveness of the existing base- and peak-load futures contracts as a risk management tool for the electricity retailers. We analytically characterize the retailer’s optimal hedging policy as a function of the serial correlation of the prices and the demand profiles of its customers. We find that the retailer typically over-hedges in the futures market, and the over-hedging amount increases when both base- and peak-load contracts are used. Our findings indicate that although the existing contracts in the futures market are quite efficient to replicate the exposure from profiled customers, when industrial consumers and renewable generation are included to the retailer’s portfolio, the effectiveness of such contracts decreases substantially. In our motivating example, hedging the risk of the profiled customers with base-load contracts, the firm may reduce the variance of its cash flows by 85.9%. In addition to the base-load contracts, including peak-load contracts into the hedging portfolio of the retailer increases the efficiency of hedging to 89.3%. However, when we consider the aggregate portfolio of the retailer including profiled customers, industrial consumers and renewable contracts, the efficiency of hedging through the existing futures contracts goes down as low as 32.8% during certain periods. © 2022, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.

Sürdürülebilir Kalkınma Amaçları (SKA’lar), dünyanın karşı karşıya kaldığı çevresel, ekonomik ve sosyal sorunlarla mücadele edilmesine yardımcı olmak üzere Birleşmiş Milletler (BM) tarafından 2015 yılında kabul edilen amaç ve hedeflerden oluşmaktadır. Yüksek denetim kurumları (YDK’lar), sürdürülebilir kalkınma için etkili, hesap verebilir, şeffaf, etkin ve kapsayıcı kurumların merkezinde yer almakta olup bireysel yetki ve görevleri çerçevesinde SKA’ları takip eder ve gözden geçirirler. Sürdürülebilir kalkınmanın öneminin artması ile YDK’lar, çevreye ve çevre politikasına karşı rol ve sorumluluklarının farkına varmış ve çevre denetimi, YDK’ların denetim faaliyetlerinin önemli bir parçası haline dönüşmüştür. Çalışma YDK’ların çevre denetimini SKA’lar çerçevesinde ele almayı amaçlamakta olup çevre denetiminin SKA’lara nasıl katkıda bulunabileceğini incelemektedir. Bu kapsamda sürdürülebilir kalkınma ve YDK’lar arasındaki ilişkiye ilişkin literatürden, Çevre Denetimi Çalışma Grubu (Working Group of Environmental Auditing - WGEA) tarafından yayımlanan anket bulgularından ve YDK’ların denetim raporlarından yararlanarak konuya ilişkin yeni değerlendirmelerde bulunulmuştur. Çalışmada çevre denetiminin SKA’lara ulaşılmasına olumlu katkı yapabileceği, YDK’ların gözetim işlevlerini kullanarak SKA’ların uygulanması konusunda mali kaynakların etkin, etkili ve şeffaf harcanmasını teşvik edebileceği ve bu anlamda hükümetleri sorumlu tutabileceği ve bağımsız bilgiler sağlayabileceği belirlenmiştir.

With the increasing need for energy in the world, the demand for renewable energy sources is increasing day by day. This increase in energy need directs governments and private sector investors to renewable energy sources. Wind energy is one of the most important renewable energy resources on earth. In recent years, the share of wind energy in the amount of energy produced by renewable energy sources has been increasing. Wind energy emerges as a sustainable energy source due to its environmental friendliness and ability to renew itself. These features of wind energy have a great effect on the increase of its share in the energy sector. In order to get the highest efficiency from wind energy, the correct positioning of wind farms, that is, the concept of site selection is very important. One of the most important parameters in site selection of wind farms is the wind energy source and the wind speed accordingly. In order to create wind speed maps, wind speed data obtained from a certain number of stations should be interpolated for the study area. In this study, wind speed data obtained from 32 meteorology stations in Balikesir province were used. With the help of these data, wind velocity maps were created with five different interpolation methods, namely IDW, Kriging, Natural Neighbor, Spline and Trend, within the borders of Balikesir province. Finally, the results obtained by these five methods were compared with the real wind speed values according to root mean square error and evaluations were made.

Data collected for the manuscript titled "Sustainability in Street Food: Elaboration Likelihood Model (ELM) and Image Theory Perspective". Data collected for the manuscript titled "Sustainability in Street Food: Elaboration Likelihood Model (ELM) and Image Theory Perspective".

Bioenergy is considered a sustainable substitute to fossil-fuel resources and the development of a prudent combination of renewable and innovative conversion technologies are essential for the valorization and effective conversion of biowaste to value-added commodities. Here, a negative pressure-induced carbonization process was proposed for the valorization of lignin-enriched biowaste precursor to bio-oil and environmental materials (biochar) at various temperatures. The high heating values (HHV) of the as-prepared biochars from the lignin enriched precursor under negative pressure (low-medium vacuum) were within 25.9-31.5 MJ/kg, which matched satisfactorily to the commercial charcoal. Whereas, the bio-oils produced from the lignin enriched precursor under vacuum conditions was a blend of complex aromatic and straight-chain hydro-carbons, including aldehyde, ketone, phenol, and furans, exhibiting ability as potential heating-oil with HHV within 21.2-28.2 MJ/kg. Moreover, the biochars produced under vacuum environments at higher temperature showed greater stability (22.5-35.9%) than those produced under N2 atmosphere.

Abstract To obtain more photosensitive S-diodes, silicon should be compensated for by impurities, which increase the photosensitivity of the original crystals. Diffusion of vanadium in silicon was carried out in evacuated or open quartz ampoules at a temperature of 900-1250 °C for 2-20 hours. Silicon wafers 0.5-1.0 mm thick and an alloying element of vanadium were placed in the ampoule. Usually used n-Si with ρ ~ 5 ÷ 200 Ω·sm and with a thickness of 0.2-0.5 mm. The concentration of deep levels introduced during diffusion was 1014 cm-3. The resistivity of silicon after diffusion increased to 103-104 Ω·sm at 300 K, and the diffusion length Ld decreased to 10-30 μm. S-diodes were made in a vacuum by melting aluminum and Au + 0.1% Sb alloy at 700 °C for 1 min. The contact area (S) is approximately 0.2 mm2, the base thickness d = 0.2-1.0 mm. Attitude d/Ld≈10 ÷ 100. Iincline ~ 1/tinclusion in a wide range of currents is linear, where Iincline> Ibre. Determined by the slope Iincline ~ 1/tinclusion the charge is Qcr = 3.52·10-9C. In this case, the average concentration of injected current carriers in the base is n = 5.44·1013 cm-3, which is in good agreement with the concentration of electroactive atoms V in Si, determined by capacitive methods. The dependence 1 V t − 1 V ∞ for S-diodes from n-Si <V> has a complex form at each temperature and is approximated by two exponents. The obtained experimental results, their analysis and conclusions on S-diodes from Si <V> can be used as a temperature relay, photo relay, switches and photodetectors controlled by the sensitivity current.

In this study, a non-analog Monte Carlo method is developed to simulate the albedo and transmission factor of an infinite non-multiplying slab media subjected to a direction-dependent one-speed neutron beam on the left side. In order to obtain more precise results different variance reduction techniques such as forced collision, implicit capture, and Russian-Roulette are taken into consideration. For different incident directions of the neutrons and in the case of both isotropic and linear anisotropic scatterings, the albedo and transmission factor are estimated from the Monte Carlo and compared with the results obtained from the H_(N=7) deterministic method. It is seen that in most cases, the results of both Monte Carlo and H_(N=7) methods are comparable with each other. In some cases, it is also observed that the deterministic method falls short in predicting the albedo and transmission factor, whereas, in contrast, the results of the Monte Carlo are physically meaningful.

Abstract In this article, an attempt is made to better understand the contribution of hydropower in meeting electric energy needs of Turkey. Thus, a comparison between Turkey and other countries, which have some similarities with Turkey or which are more developed nations compared to Turkey, for evaluating from different aspects the contribution of hydropower in meeting electric energy needs is performed. The producers of electricity and hydroelectricity in the world, and the electric sectors of all the selected countries are firstly examined. Thereafter, Turkey's water resources and its potential, hydropower potential, and current status of hydropower in Turkey are investigated in detail. A detailed discussion regarding economic and energy indicators, hydroelectricity versus thermal electricity, the contributions of hydroelectricity to the total and renewable electricity generation, and the usage status of hydro potential of each selected nation is also made. Finally, it is found that hydropower is the second largest contributor in meeting Turkey's electric energy needs after thermal, mainly natural gas. It is also estimated that the contribution of hydropower will continue because a vast amount of its economically feasible hydro potential (about 64%) is undeveloped. Besides, it is determined that the contribution of hydropower in the total electricity generation in Turkey is greater than that of China and India, but it is lower than that of Norway, Brazil, and Canada.