Technological advances of membrane seawater desalination have propelled its worldwide use. Despite the two-fold reduction of its power demand over the past 20years, seawater desalination remains the ...most energy intensive alternative for production of fresh drinking water at present. This article provides an overview of the current status of energy use for seawater desalination, discusses the minimum energy demand for production of fresh water and presents key factors that influence the desalination plant energy demand for the site specific conditions of a given desalination project. The article describes key benefits and challenges associated with the implementation of energy-saving technologies and equipment such as: collocation of desalination and power plants; alternative RO system configurations proven to yield significant energy savings such as; low-recovery plant design; use of split permeate two-pass RO system configuration; three-center RO system design; and use of high productivity/low energy membrane elements, hybrid RO membrane vessel configurations, large-size high efficiency pumps and pressure-exchanger based energy recovery systems. The article also discusses emerging desalination technologies with high-energy reduction potential and provides a forecast of the potential impact of future technologies on energy use for membrane desalination.
This study extends the Marshallian demand framework to investigate the effects of TI (technological innovation) on energy use in Malaysia. This extended theoretical frameworks predicts that TI, an ...exogenous element in the energy demand function, increases energy efficiency and, correspondingly, reduces energy consumption at a given level of economic output. Using an ARDL (autoregressive distributed lag) bounds testing approach for the sample period 1985–2012, this study confirms both short- and log-run theoretical predictions. However, controlling for the effect of TI, this study finds that increasing GDP per capita and trade openness produce a rebound effect of TI on energy use.
•Technological innovation increases energy efficiency in the long run.•GDP per capita intensifies the energy use in the short run and long run.•Trade openness augments energy use in the long run.
In this Letter we study a system consisting of two nearly degenerate mechanical modes that couple to a single mode of an optical cavity. We show that this coupling leads to nearly complete (99.5%) ...hybridization of the two mechanical modes into a bright mode that experiences strong optomechanical interactions and a dark mode that experiences almost no optomechanical interactions. We use this hybridization to transfer energy between the mechanical modes with 40% efficiency.
The operation of hydrogen fuel cell electric vehicles (HFCEVs) is more efficient than that of gasoline conventional internal combustion engine vehicles (ICEVs), and produces zero tailpipe pollutant ...emissions. However, the production, transportation, and refueling of hydrogen are more energy- and emissions-intensive compared to gasoline. A well-to-wheels (WTW) energy use and emissions analysis was conducted to compare a HFCEV (Toyota Mirai) with a gasoline conventional ICEV (Mazda 3). Two sets of specific fuel consumption data were used for each vehicle: (1) fuel consumption derived from the U.S. Environmental Protection Agency's (EPA's) window-sticker fuel economy figure, and (2) weight-averaged fuel consumption based on physical vehicle testing with a chassis dynamometer on EPA's five standard driving cycles. The WTW results show that a HFCEV, even fueled by hydrogen from a fossil-based production pathway (via steam methane reforming of natural gas), uses 5%–33% less WTW fossil energy and has 15%–45% lower WTW greenhouse gas emissions compared to a gasoline conventional ICEV. The WTW results are sensitive to the source of electricity used for hydrogen compression or liquefaction.
•Conducted well-to-wheels (WTW) analysis of H2 fuel cell electric vehicle (HFCEV).•Compared WTW result to that of gasoline internal combustion engine vehicle (ICEV).•Incorporated both lab testing and window sticker fuel consumption data.•HFCEV produces 15–45% less WTW greenhouse gas emissions compared to gasoline ICEV.•WTW result is sensitive to electricity source for H2 compression or liquefaction.
•Review state-of-the-art research on occupant energy behaviors in buildings.•Discuss current obstacles, future needs and directions in occupant behavior simulation.•4 key areas: data collection, ...model development, evaluation and integration with tools.•Propose new research areas to advance occupant behavior modeling and simulation.
Occupant behavior is now widely recognized as a major contributing factor to uncertainty of building performance. While a surge of research on the topic has occurred over the past four decades, and particularly the past few years, there are many gaps in knowledge and limitations to current methodologies. This paper outlines the state-of-the-art research, current obstacles and future needs and directions for the following four-step iterative process: (1) occupant monitoring and data collection, (2) model development, (3) model evaluation, and (4) model implementation into building simulation tools. Major themes include the need for greater rigor in experimental methodologies; detailed, honest, and candid reporting of methods and results; and development of an efficient means to implement occupant behavior models and integrate them into building energy modeling programs.
Ultrahigh energy neutrinos are interesting messenger particles since, if detected, they can transmit exclusive information about ultrahigh energy processes in the Universe. These particles, with ...energies above 10 super(16)eV , interact very rarely. Therefore, detectors that instrument several gigatons of matter are needed to discover them. The ARA detector is currently being constructed at the South Pole. It is designed to use the Askaryan effect, the emission of radio waves from neutrino-induced cascades in the South Pole ice, to detect neutrino interactions at very high energies. With antennas distributed among 37 widely separated stations in the ice, such interactions can be observed in a volume of several hundred cubic kilometers. Currently three deep ARA stations are deployed in the ice, of which two have been taking data since the beginning of 2013. In this article, the ARA detector "as built" and calibrations are described. Data reduction methods used to distinguish the rare radio signals from overwhelming backgrounds of thermal and anthropogenic origin are presented. Using data from only two stations over a short exposure time of 10 months, a neutrino flux limit of 1.5x10 super(-6)GeV/cm super(2)/s/sr is calculated for a particle energy of 10 super(18)eV , which offers promise for the full ARA detector.
Engineered wettability is a traditional, yet key issue in surface science and attracts tremendous interest in solving large‐scale practical problems. Recently, different super‐wettability systems ...have been discovered in both nature and experiments. In this Review we present three types of super‐wettability, including the three‐dimensional, two‐dimensional, and one‐dimensional material surfaces. By combining different super‐wettabilities, novel interfacial functional systems could be generated and integrated into devices for use in tackling current and the future problems including resources, energy, environment, and health.
Wet, wet, wet: Surfaces with super‐wettability, including three‐dimensional, two‐dimensional, and one‐dimensional materials surfaces can be prepared. By combining different super‐wettability properties, novel functional solid/liquid interfacial systems can be generated and integrated into devices for tackling many different problems.
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