Optimisation of a combined Stirling cycle–organic Rankine cycle using a genetic algorithm

In a Stirling cycle a huge amount of energy is wasted due to the losses. This wasted energy may be utilised as a heat source for the boiler of an organic Rankine cycle (ORC). Combination of these two cycles leads to an increased cycle efficiency compared to a single Stirling cycle and the analysis and optimisation of the integrated system is carried out. Optimisation is performed using the genetic algorithm and considering three decision variables: the temperature of the cold tank of the Stirling cycle, the pressure ratio and the temperature of the ORC condenser. In optimisation, the efficiency is considered as the objective function and the highest value is achieved by adjusting the decision variables. Using this method, the efficiency of the overall combined cycle was improved in which the highest efficiency was obtained to be 41.5%.     

High triplet energy Al complex as a host material for blue phosphorescent organic light-emitting diodes

An Al complex, tris((2-(pyrazol-1-yl)pyridin-3-yl)oxy)aluminum (Al(pypy)₃), was synthesized as a high triplet energy host material for blue phosphorescent organic light-emitting diodes. A high triplet energy ligand, 2-(1H-pyrazol-1-yl)pyridin-3-ol, was coordinated to the Al to develop the high triplet energy host material derived from Al. The Al(pypy)₃ host showed a high triplet energy of 2.86 eV for efficient energy transfer to blue triplet emitter. A maximum quantum efficiency of 20.5% was achieved in blue device using the Al(pypy)₃ host material.     

Spring Maize Yield Estimation based on Radiation Use Efficiency and Multi-temporal Remotely Sensed Data

In order to develop highly accurate model for crop yield estimation,an approach of retrieving regional crop yield was studied by Radiation Use Efficiency (RUE) and remote sensing data,the Jifangzha irrigation is of Hetao irrigation district of Inner Mongolia Autonomous Region was selected as a research case.Based on this model,the difference of the Dry Matter Accumulation (DMA) between the maize’s different growing stages is made and a comparative analysis of the measured yields,and the predicted results based on this model.The results show that the DMA of the maize’s jointing stage is maximal,about 40% of total amount.The measured yield and the predicted ones based on the model has a greater correlation,the Correlation Coefficient was 0.853 and passed the reliability of 0.01.The difference of the DMA in different growing stages showed that the sensitive degree was displayed between main growing stages and yield,and that were some key aspects:the main limiting factor in growing stages and raising yield.These results indicate the model for spring maize yield estimation is feasible and effective based on the RUE and multi-temporal remotely sensing data.     

Coumarin based sensitizers with ortho-halides substituted phenylene spacer for dye sensitized solar cells

The performance of DSSCs (dye sensitized solar cells) with a new series of dyes having different halide groups (i.e. F, Cl and Br) on o-position substituted phenyl spacers with same coumarin donor moieties have been reported. Optical, electrochemical, molecular orbital and photovoltaic properties were studied by varying the halide groups using these dyes. The replacement of halide atoms in same coumarin based dye had a significant effect on the short circuit current density (J_sc), open circuit voltage (V_oc), and photo conversion efficiency (PCE). The J_sc and PCE of dye CD-1 (fluorine substituted) are 10.3 mA/cm² and 5.2% respectively, which is higher than CD-2 (chlorine substituted) and CD-3 (bromine substituted) dyes (having PCE 4.1% and 3.5% respectively) devices. The optimized geometry calculation of o-halide phenyl π-spacer dyes were ascertained by density functional theory (DFT) using the B3LYP/6-31G(d,p) basis set. Moreover, we have checked the effect of various substituents in the same dye structure by DFT analysis.     

A novel energy-driven computing paradigm for e-health scenarios

A first-rate e-Health system saves lives, provides better patient care, allows complex but useful epidemiologic analysis and saves money. However, there may also be concerns about the costs and complexities associated with e-health implementation, and the need to solve issues about the energy footprint of the high-demanding computing facilities. This paper proposes a novel and evolved computing paradigm that: (i) provides the required computing and sensing resources; (ii) allows the population-wide diffusion; (iii) exploits the storage, communication and computing services provided by the Cloud; (iv) tackles the energy-optimization issue as a first-class requirement, taking it into account during the whole development cycle. The novel computing concept and the multi-layer top-down energy-optimization methodology obtain promising results in a realistic scenario for cardiovascular tracking and analysis, making the Home Assisted Living a reality.     

Experimental Verification for Practical Application of Inductive Power Transfer System for Railway

Inductive Power Transfer systems (IPT systems) for moving Electrical Vehicles (EVs) are often discussed. However, an IPT system for moving railway vehicles has not been sufficiently examined. In order to employ the IPT system for railway vehicles, this paper examines the characteristics of railway IPT systems, such as efficiency, temperature rise, and durability. Because the required characteristics of the IPT system for railway are different from those of EV, one example of a railway IPT system is proposed, and the verification items for practical use are examined. Moreover, we manufactured test equipment that can imitate the field environment in order to verify these items before practical use in the field. The test procedure and test results demonstrate the possibility of practical use of a railway IPT system.     

A Closer Look at the Design of Cutterheads for Hard Rock Tunnel-Boring Machines

The success of a tunnel-boring machine (TBM) in a given project depends on the functionality of all components of the system, from the cutters to the backup system, and on the entire rolling stock. However, no part of the machine plays a more crucial role in the efficient operation of the machine than its cutterhead. The design of the cutterhead impacts the efficiency of cutting, the balance of the head, the life of the cutters, the maintenance of the main bearing/gearbox, and the effectiveness of the mucking along with its effects on the wear of the face and gage cutters/muck buckets. Overall, cutterhead design heavily impacts the rate of penetration (ROP), rate of machine utilization (U), and daily advance rate (AR). Although there has been some discussion in commonly available publications regarding disk cutters, cutting forces, and some design features of the head, there is limited literature on this subject because the design of cutterheads is mainly handled by machine manufacturers. Most of the design process involves proprietary algorithms by the manufacturers, and despite recent attention on the subject, the design of rock TBMs has been somewhat of a mystery to most end-users. This paper is an attempt to demystify the basic concepts in design. Although it may not be sufficient for a full-fledged design by the readers, this paper allows engineers and contractors to understand the thought process in the design steps, what to look for in a proper design, and the implications of the head design on machine operation and life cycle.     

Eco-Physic: Eco-Physical design initiative for very large databases

In the Big Data Era, the management of energy consumption by servers and data centers has become a challenging issue for companies, institutions, and countries. In data-centric applications, Database Management Systems are one of the major energy consumers when executing complex queries involving very large databases. Several initiatives have been proposed to deal with this issue, covering both the hardware and software dimensions. They can be classified in two main approaches assuming that either (a) the database is already deployed on a given platform, or (b) it is not yet deployed. In this study, we focus on the first set of initiatives with a particular interest in physical design, where optimization structures (e.g., indexes, materialized views) are selected to satisfy a given set of non-functional requirements such as query performance for a given workload. In this paper, we first propose an initiative, called Eco-Physic, which integrates the energy dimension into the physical design when selecting materialized views, one of the redundant optimization structures. Secondly, we provide a multi-objective formalization of the materialized view selection problem, considering two non-functional requirements: query performance and energy consumption while executing a given workload. Thirdly, an evolutionary algorithm is developed to solve the problem. This algorithm differs from the existing ones by being interactive, so that database administrators can adjust some energy sensitive parameters at the final stage of the algorithm execution according to their specifications. Finally, intensive experiments are conducted using our mathematical cost model and a real device for energy measurements. Results underscore the value of our approach as an effective way to save energy while optimizing queries through materialized views structures.     

An overview of utilizing water-in-diesel emulsion fuel in diesel engine and its potential research study

The need for more efficient energy usage and a less polluted environment are the prominent research areas that are currently being investigated by many researchers worldwide. Water-in-diesel emulsion fuel (W/D) is a promising alternative fuel that could fulfills such requests in that it can improve the combustion efficiency of a diesel engine and reduce harmful exhaust emission, especially nitrogen oxides (NO_x) and particulate matter (PM). To date, there have been many W/D emulsion fuel studies, especially regarding performance, emissions and micro-explosion phenomena. This review paper gathers and discusses the recent advances in emulsion fuel studies in respect of the impact of W/D emulsion fuel on the performance and emission of diesel engines, micro-explosion phenomena especially the factors that affecting the onset and strength of micro-explosion process, and proposed potential research area in W/D emulsion fuel study. There is an inconsistency in the results reported from previous studies especially for the thermal efficiency, brake power, torque and specific fuel consumption. However, it is agreed by most of the studies that W/D does result in an improvement in these measurements when the total amount of diesel fuel in the emulsion is compared with that of the neat diesel fuel. NO_x and PM exhaust gas emissions are greatly reduced by using the W/D emulsion fuel. Unburnt hydrocarbon (UHC) and carbon monoxide (CO) exhaust emissions are found to be increased by using the W/D emulsion fuel. The inconsistency of the experimental result can be related to the effects of the onset and the strength of the micro-explosion process. The factors that affect these measurements consist of the size of the dispersed water particle, droplet size of the emulsion, water-content in the emulsion, ambient temperature, ambient pressure, type and percentage of surfactant, type of diesel engine and engine operating conditions. Durability testing and developing the fuel production device that requires no/less surfactant are the potential research area that can be explored in future.     

Participatory system dynamics modelling for housing,energy and wellbeing interactions

The built environment is a key target of decarbonization policies. However, such policies often have a narrow objective and narrow focus, resulting in ‘policy-resistance’ and unintended consequences. The literature attributes these unintended consequences to a narrow financial focus, adverse incentives, and inadequate handling of knowledge, skills, communication and feedback gaps, but it provides little advice on how these complex interactions can be captured. This paper illustrates the development and application of an integrated approach to address these complex interactions with regard to housing performance, energy, communal spaces and wellbeing. In particular, it explores the dynamics created by these relationships with simulation modelling in participatory settings, and with a diverse group of stakeholders. The simulation results suggest that monitoring is key to improve the performance of the housing stock besides energy efficiency; and investments in communal spaces positively affect the adoption of energy-efficiency measures and the wellbeing of residents. The evaluation results for participatory workshops show this approach was found useful by the stakeholders for supporting more integrated decision-making about housing. In future research, this approach can be implemented for policy problems in specific contexts.