Hybrid Satellite-Terrestrial Communication Networks for the Maritime Internet of Things: Key Technologies, Opportunities, and Challenges

With the rapid development of marine activities, there has been an increasing number of maritime mobile terminals, as well as a growing demand for high-speed and ultra-reliable maritime communications to keep them connected. Traditionally, the maritime Internet of Things (IoT) is enabled by maritime satellites. However, satellites are seriously restricted by their high latency and relatively low data rate. As an alternative, shore & island-based base stations (BSs) can be built to extend the coverage of terrestrial networks using fourth-generation (4G), fifth-generation (5G), and beyond 5G services. Unmanned aerial vehicles can also be exploited to serve as aerial maritime BSs. Despite of all these approaches, there are still open issues for an efficient maritime communication network (MCN). For example, due to the complicated electromagnetic propagation environment, the limited geometrically available BS sites, and rigorous service demands from mission-critical applications, conventional communication and networking theories and methods should be tailored for maritime scenarios. Towards this end, we provide a survey on the demand for maritime communications, the state-of-the-art MCNs, and key technologies for enhancing transmission efficiency, extending network coverage, and provisioning maritime-specific services. Future challenges in developing an environment-aware, service-driven, and integrated satellite-air-ground MCN to be smart enough to utilize external auxiliary information, e.g., sea state and atmosphere conditions, are also discussed

On-site Energy Management by Integrating Campus Buildings and Optimizing Local Energy Systems ‒ Case Study of the Campus in Finland

This research describes the potential study on the impact of energy improvements of existing campus buildings by on-site energy management and operational strategies. The focus buildings in the campus were mainly built in the 1960s, and therefore it is time to carry out renovation work. In conjunction with the renovations, the aim is to improve the energy efficiency of the buildings, and to develop the functionality of the properties to meet the current requirements. Thus, in this study, the potentials of on-site energy generation and sharing in the cluster of campus buildings in Finland were studied. By means of optimisation method, the optimal combined heat and power systems capacity distribution and operation mode for minimizing annual primary energy consumption were simulated. The results show that the integration of buildings has an advantage of 23% of primary energy reduction for on-site energy management as compared with the present situation. Consequently, integrating buildings and optimizing on-site energy management can be one of effective strategies for minimizing primary energy consumption. Furthermore, the study to improve operation strategies of building service systems considering current space use in the buildings clarified that up to 13% of total energy use reduction is expected. The research work also proposes a way of providing environmental information to increase awareness of building energy usage in the campus

Sustainable use and production of energy in the 21st century

It is foreseen that oil and gas will continue to be the key energy sources in the 21st century. Therefore, it is important that oil and gas be produced in a sustainable way during the next decades. This requires technology development to ensure that the environmental impact and pollution from these activities are minimal. The following aspects are being highlighted in this paper: • Development of projects with the minimum of impact on the environment and problems for local populations. • Sustainable drilling without the use of oil-based mud, and collection of all drilling waste during offshore drilling operations in the most environmentally sensitive areas. • Treatment of produced water, sand and minerals from the well stream to avoid pollution. • Limitation of flaring to be performed only when required for safety reasons. • Continuous checking of pipelines to ensure that gas pipelines are run within their actual pressure capacity and that oil pipelines are not leaking into rivers and lakes. • Provision of sufficient storage capacity for gas to ensure timely delivery of gas during high demand peaks. • Injection of CO2 into sealed underground formations where large quantities are produced, such as at LNG factories. • Optimization of production from existing fields to avoid huge amounts of oil and gas being left in place, following a ‘hit and run’ recovery plan. Furthermore, all primary energy sources need to be converted into end-user energy services known as mechanical work, electricity, heating and cooling. In the process of conversion, only a portion of the primary energy is transformed into the new form, while the rest remains unaltered and is lost. The various forms of energy services produced represent different values or qualities, e.g. heat holds an energy quality ranging from 0 and upwards, depending on the temperature difference which is utilized, as defined by the second law of thermodynamics. Energy efficiency in this context may also be defined as the ratio between energy quality output and input. Practically, all fossil fuels are converted into energy services via combustion and heat, i.e. the conversion efficiency is solely determined by temperatures, meaning that high-energy efficiency can only be obtained at large temperature differences, such as in power generation, while ordinary domestic heating will yield a very low efficiency. Given that some 30–40 % of all fossil fuels today are used for domestic heating, representing an end-user energy quality of (say) 1/10 of what is obtained in modern power generation, there is a large potential globally for energy efficiency improvements, not to mention the associated emission reductions. The obvious solution is to pay more attention to the second law of thermodynamics, i.e. to shift from direct combustion heating to thermodynamic principles, e.g. by the use of electrical-driven heat pumps and/or combined heat and power as another alternative. The objectives of this paper are to highlight how energy production could become more effective, thus leading to a reduction in pollution to land, sea and atmosphere and also to identify how energy production should be carried out to minimize the polluting effects. The goal is to provide a reminder that much can be gained with respect to the reduction of pollution by focusing on cleaner energy production

Aerospace medicine and biology: A continuing bibliography with indexes (supplement 355)

This bibliography lists 147 reports, articles and other documents introduced into the NASA Scientific and Technical Information System during October, 1991. Subject coverage includes: aerospace medicine and psychology, life support systems and controlled environments, safety equipment, exobiology and extraterrestrial life, and flight crew behavior and performance