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Timekeeping is important at two levels: to time changes in physiology and behavior within each day and within each year. For the former, birds have a system of at least three independent circadian clocks present in the retina of the eyes, the pineal gland, and the hypothalamus. This differs from the situation in mammals in which the input, pacemaker, and output are localized in different structures. Each bird clock interacts with at least one other clock, and together, they appear to form a centralized clock system that keeps daily time. These clocks have a powerful endogenous component, and the daily light-dark cycle entrains them to 24 h. The timing and duration of life history stages that make up annual cycle of an individual must also be controlled by some form of timekeeping. However, evidence for the existence of an equivalent endogenous circannual clock is less clear. Environmental cues, particularly photoperiod, appear to have a more direct role than simply entraining the clock to calendar time. For example, the timing of migration is probably greatly influenced by photoperiod, but its manifestation each day, as Zugunruhe, appears to be under circadian control. Migration involves marked changes in physiology to cope with the energetic demands. There is still much that we do not know about how organisms' timekeeping systems respond to their natural environment, particularly how salient signals from the environment are perceived and then transduced into appropriately timed biological functions. However, given that changes in environmental input affects the clock, increasing human disturbance of the environment is likely to adversely affect these systems.

Head objective of the paper is to create and stimulate a Novel Dual Stator Sandwiched Rotor Hybrid Magnetic Pole Six-Phase PMSG (NDSSRHMPSP-PMSG) for harnessing wind power. Wind energy is the most optimized plan for innovation since it erases the need of water and is eco-accommodating and can be a superior option for expanded energy usage. A multiphase PMSG is a superior alternative for wind energy utilization. The two-fold rotor-stator setup upgrades the machine’s voltage regulation as well as its dependability and execution. The designed NDSSRHMPSPPMSG possesses novelty in terms of its magnet structure. A Hybrid Magnetic Pole (HMP) is inserted into the rotatory portions. The concept of HMP introduces the combination of V-Shaped Magnets (VSM) and Multi-Layer Embedded Magnets (MLEM). This remarkable combination of two different magnetic formation provides a higher flux density and contributes towards an efficient operation of the proposed system. To construct the generator optimally and for evaluation, magnetostatic and transient setups are used. Because of proper examination, it may be very well presumed that the proposed novel framework is legitimate and effective.

Often the several stakeholders involved in the agricultural sector place a greater emphasis on the negative externalities from farming production rather than on the solutions and approaches to mitigate, namely impacts from pollution. The scientific literature, in certain circumstances, follows this tendency leaving a vast chasm of enormous potential left to be explored. It is important to contribute towards the reduction of this gap, highlighting the best management practices implemented across the agricultural sector around the world, specifically to make them more visible and give incentive to the several agents in adopting and spreading their use. In this way, the main objective is to stress the best management practices presented by the global scientific literature from the farming sector. To achieve this objective methodology based on bibliometric analysis-factor-analysis-literature survey approach was considered, applied to 150 documents obtained from the Web of Science (core collection) related with the following topics: best management practice; agricultural economics; air, soil and water pollution. As main insights, it is worth referring the best management practices to deal with problems from agricultural production, such as, for example, the use of agricultural residues as feedstock for renewable energies. With regard to sustainable development in the agricultural sector, concepts such as "sustainable remediation" have their place. On the other hand, the agricultural and environmental policies and the agricultural costs associated with the several farming practices also play a determinant role here. Finally, only fraction of the scientific documents analysed (16 papers) belong to the group of studies related to policies, showing that there are potential subjects to be addressed here in future studies related with these topics. The same happens for cost-benefit analyses (24 documents).

Abstract In an increasingly decentralized energy market, micro gas turbines are seen with great potential due to their low emissions and fuel flexibility, which aligns with growing environmental concerns. Although presenting a relatively low efficiency, these machines could be improved by coupling it with an organic Rankine cycle. This manuscript covers the thermoeconomic design and optimization of such bottoming cycle for a 100 kWe micro gas turbine. The tool employed for such calculations is extensively described and was developed using solely open resources. The results shown that the saturation temperature at ambient pressure was an important variable when the minimum pressure is constrained above ambient and that a high degree of superheating was favored when the recuperated cycle is heated directly by the microturbine flue gases. Pentane was flagged as the best working fluid, generating 14.1 kWe of additional power and increasing the overall electric efficiency from 30 to 34.2%. The Authors show that at the current state of the art an efficiency of around 35% is the upper practical limit for such microturbine organic Rankine cycle combination.

Because of the metaphysical shift in the technological era, the world is witnessing machine to machine (M2M) communication. Sensors are omnipresent, owing to which wireless sensor networks (WSNs) are developing as a key enabling technology for the Internet of Things (IoT). M2M interaction poses a severe threat to the lifetime of the network. Clustering plays an essential role in elevating the energy efficiency of the WSN. Particularly, uniform distribution of cluster heads (CHs) is crucial for achieving better network lifetime and uninterrupted sensing from the area under observation. For this, we propose an efficient two-fold clustering algorithm, namely second-fold clustering (SFC). In the first phase, the selection of CH is made based on zonal residual energy and zonal degree of connectivity. In the second phase, the leftover nodes known as isolated nodes are clumped. CH is selected based on the zonal degree of connectivity to ensure that energy is disbursed (almost) uniformly by all the nodes. This uniformity makes it suitable for integration with the IoT. To find out the efficacy of SFC, carried rigorous experimental study out where it is compared to two existing clustering algorithms. The simulation results show that SFC outperforms its counterparts. The results showed that SFC improved network lifetime by approximately 9.6% and 10.2% compared to regional energy-aware clustering scheme and Residual-Low Energy Adaptive Clustering Hierarchy (R-LEACH), respectively.

Abstract The environmental impacts of brine disposal from seawater desalination plants and wastewater treatment plants represent a subject of growing concern; thus, determining the potential applicability of zero liquid discharge (ZLD) for water treatment is crucial. Membrane-based technologies are a potentially attractive strategy that can be used to reach this goal. Recent studies have highlighted that integrating a series of membrane processes is a viable approach to achieving ZLD for industrial use. However, a relatively limited number of reports have been published on the challenging problems encountered with ZLD approaches. Here, we provide a review of membrane processes that may be used in ZLD approaches and describe their problems as well as potential solutions and innovative technologies for improving their performance. Furthermore, the energy consumption of the different approaches is calculated and analyzed because it represents a major contributor to the total cost, and investments in innovative technologies are discussed. Finally, the prospects for membrane-based ZLD and further research are highlighted.

Abstract The generation of RES electricity in urban areas is regarded as a key element in achieving the 20% emission reduction target by 2020, in line with the strategy adopted by the European Union (EU). To understand the actual role of renewable energy planning in cities, as well as the adequacy of the strategies adopted, the authors considered statistics officially reported by the Joint Research Centre of the EU which regard the totality of submitted SEAPs and ten Sustainable Energy Action Plans (SEAPs) as sample cities. The double survey has a dual goal: one, the collection of overall statistics to have a general framework of all cities that submitted their SEAPs and to verify their inclusion of renewables, and two, the analysis of urban planning processes and climatic features through a sample of representative cities to try to determine direct connections between the implementation of renewables and real source potentials (an aspect not present in the JRC reports). Making comparisons between SEAPs submitted by European cities, the authors report in the final discussion the merits and drawbacks of the planning and usage of renewable sources in urban areas, thereby highlighting some relevant critical points and possible directions for future research efforts.

In this paper an attempt has been made to derive the analytical expressions for N hybrid photovoltaic/thermal (PV/T) air collectors connected in series. The performance of collectors is evaluated by considering the two different cases, namely, Case I (air collector is fully covered by PV module (glass to glass) and air flows above the absorber plate) and Case II (air collector is fully covered by PV module (glass to glass) and air flows below the absorber plate). This paper shows the detailed analysis of energy, exergy and electrical energy by varying the number of collectors and air velocity considering four weather conditions (a, b, c and d type) and five different cities (New Delhi, Bangalore, Mumbai, Srinagar, and Jodhpur) of India. It is found that the collectors fully covered by PV module and air flows below the absorber plate gives better results in terms of thermal energy, electrical energy and exergy gain. Physical implementation of BIPV system has also been evaluated. If this type of system is installed on roof of building or integrated with building envelope will simultaneously fulfill the electricity generation for lighting purpose and hot air can be used for space heating or drying.

The paper reports the findings of a two-year pilot scale experimental trial for the mesophilic (35°C), thermophilic (55°C) and temperature phased (65+55°C) anaerobic digestion of waste activated sludge. During the mesophilic and thermophilic runs, the reactor operated at an organic loading rate of 2.2 kgVS/m(3)d and a hydraulic retention time of 20 days. In the temperature phased run, the first reactor operated at an organic loading rate of 15 kgVS/m(3)d and a hydraulic retention time of 2 days while the second reactor operated at an organic loading rate of 2.2 kgVS/m(3)d and a hydraulic retention time of 18 days (20 days for the whole temperature phased system). The performance of the reactor improved with increases in temperature. The COD removal increased from 35% in mesophilic conditions, to 45% in thermophilic conditions, and 55% in the two stage temperature phased system. As a consequence, the specific biogas production increased from 0.33 to 0.45 and to 0.49 m(3)/kgVS(fed) at 35, 55, and 65+55°C, respectively. The extreme thermophilic reactor working at 65°C showed a high hydrolytic capability and a specific yield of 0.33 g COD (soluble) per gVS(fed). The effluent of the extreme thermophilic reactor showed an average concentration of soluble COD and volatile fatty acids of 20 and 9 g/l, respectively. Acetic and propionic acids were the main compounds found in the acids mixture. Because of the improved digestion efficiency, organic nitrogen and phosphorus were solubilised in the bulk. Their concentration, however, did not increase as expected because of the formation of salts of hydroxyapatite and struvite inside the reactor.