Silicon nanowire and nanopore arrays promise to reduce manufacturing costs and increase the power conversion efficiency of photovoltaic devices. So far, however, photovoltaic cells based on ...nanostructured silicon exhibit lower power conversion efficiencies than conventional cells due to the enhanced photocarrier recombination associated with the nanostructures. Here, we identify and separately measure surface recombination and Auger recombination in wafer-based nanostructured silicon solar cells. By identifying the regimes of junction doping concentration in which each mechanism dominates, we were able to design and fabricate an independently confirmed 18.2%-efficient nanostructured 'black-silicon' cell that does not need the antireflection coating layer(s) normally required to reach a comparable performance level. Our results suggest design rules for efficient high-surface-area solar cells with nano- and microstructured semiconductor absorbers.
Light Detection and Ranging (LiDAR) technology has been widely used in forestry surveys in the form of airborne laser scanning (ALS), terrestrial laser scanning (TLS), and mobile laser scanning ...(MLS). The acquisition of important basic tree parameters (e.g., diameter at breast height and tree position) in forest inventory did not solve the problem of low measurement efficiency or weak GNSS signal under the canopy. A personal laser scanning (PLS) device combined with SLAM technology provides an effective solution for forest inventory under complex conditions with its light weight and flexible mobility. This study proposes a new method for calculating the volume of a cylinder using point cloud data obtained by a PLS device by fitting to a polygonal cylinder to calculate the diameter of the trunk. The point cloud data of tree trunks of different thickness were modeled using different fitting methods. The rate of correct tree trunk detection was 93.3% and the total deviation of the estimations of tree diameter at breast height (DBH) was -1.26 cm. The root mean square errors (RMSEs) of the estimations of the extracted DBH and the tree position were 1.58 cm and 26 cm, respectively. The survey efficiency of the personal laser scanning (PLS) device was 30m2/min for each investigator, compared with 0.91m2/min for the field survey. The test demonstrated that the PLS device combined with the SLAM algorithm provides an efficient and convenient solution for forest inventory.
The continuous increasing demand for energy and the diminishing tendency of petroleum resources has led to the search for alternative renewable and sustainable fuel. Biodiesel is best substitute for ...petro-diesel and also most advantageous over petro-diesel for its environmental friendliness. The quality of biodiesel fuel was found to be significant for its successful use on compression ignition engines and subsequent replacement of non-renewable fossil fuels. Conventional biodiesel separation and purification technologies were noticed to yield lower quality biodiesel fuel with resultant excessive energy and water consumptions. Membrane technology showed more potential for effective and efficient separation and purification of biodiesel. This technology need be explored for the attainment of better quality biodiesel fuels. This paper reviews the technologies used for the biodiesel separation and purification, biodiesel quality, and its effects on diesel engines. Biodiesel biodegradability, lubricity, stability, economic importance, and gaseous emissions have been discussed.
Rechargeable batteries are considered promising replacements for environmentally hazardous fossil fuel‐based energy technologies. High‐energy lithium‐metal batteries have received tremendous ...attention for use in portable electronic devices and electric vehicles. However, the low Coulombic efficiency, short life cycle, huge volume expansion, uncontrolled dendrite growth, and endless interfacial reactions of the metallic lithium anode are major obstacles in their commercialization. Extensive research efforts have been devoted to address these issues and significant progress has been made by tuning electrolyte chemistry, designing electrode frameworks, discovering nanotechnology‐based solutions, etc. This Review aims to provide a conceptual understanding of the current issues involved in using a lithium metal anode and to unveil its electrochemistry. The most recent advancements in lithium metal battery technology are outlined and suggestions for future research to develop a safe and stable lithium anode are presented.
Lithium (Li) metal anode is broadly recognized as an excellent candidate for nextgeneration energy storage devices owing to its high specific energy density. In this Review, a conceptual understanding about the key aspects of Li metal anode is provided, the most recent advancements in Li metal battery technology are outlined and suggestions for future research on Li anodes are presented.
There is an emerging need for high-sensitivity solar-blind deep ultraviolet (DUV) photodetectors with an ultra-fast response speed. Although nanoscale devices based on Ga
2
O
3
nanostructures have ...been developed, their practical applications are greatly limited by their slow response speed as well as low specific detectivity. Here, the successful fabrication of two-/three-dimensional (2D/3D) graphene (Gr)/PtSe
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/β-Ga
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O
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Schottky junction devices for high-sensitivity solar-blind DUV photodetectors is demonstrated. Benefitting from the high-quality 2D/3D Schottky junction, the vertically stacked structure, and the superior-quality transparent graphene electrode for effective carrier collection, the photodetector is highly sensitive to DUV light illumination and achieves a high responsivity of 76.2 mA/W, a large on/off current ratio of ~ 10
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, along with an ultra-high ultraviolet (UV)/visible rejection ratio of 1.8 × 10
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. More importantly, it has an ultra-fast response time of 12 µs and a remarkable specific detectivity of ~ 10
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Jones. Finally, an excellent DUV imaging capability has been identified based on the Gr/PtSe
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/β-Ga
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O
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Schottky junction photodetector, demonstrating its great potential application in DUV imaging systems.
An industrial sector uses more energy than any other end-use sectors and currently this sector is consuming about 37% of the world's total delivered energy. Energy is consumed in the industrial ...sector by a diverse group of industries including manufacturing, agriculture, mining, and construction and for a wide range of activities, such as processing and assembly, space conditioning, and lighting. This paper presents a comprehensive literature review about industrial energy saving by management, technologies and policies. Latest literatures in terms of thesis (MS and PhD), journal articles, conference proceedings, web materials, reports, books, handbooks on industrial energy management, policies and energy savings strategies have been compiled. Energy saving by management including energy audit, training programs and housekeeping beside some energy management practices in the world has been reviewed. Energy saving technologies, such as use of high efficiency motors (HEMs), variable speed drives (VSDs), economizers, leak prevention and reducing pressure drop has been reviewed. Based on energy saving technologies results, it has been found that in the industrial sectors, a sizeable amount of electric energy, emissions and utility bill can be saved using these technologies. Payback periods for different energy savings measures have been identified and found to be economically viable in most cases. Finally, various energy-saving policies for few selected countries were reviewed.
Despite the increase in scholarly attention paid to immersive technology, such as augmented reality and virtual reality, few studies have been conducted on the current state of immersive technology ...research, with no aggregation of findings and knowledge. To fill this gap, this study conducted a systematic literature review of immersive technology research in diverse settings, including education, marketing, business, and healthcare. The full range of SSCI journal articles that addressed issues related to immersive technology were searched. Based on rigorous inclusion and exclusion criteria, 54 articles were selected for the final analysis. This literature review analyzed the bibliometric data from the identified studies, their theoretical and methodological approaches, research themes, and contexts. Drawing on the stimulus–organism–response (S–O–R) framework, this study classifies and consolidates the factors associated with immersive technology use. Based on that classification, this study proposes a conceptual framework that accounts for the interplay between key elements associated with immersive technology use. The list of factors was then consolidated and mapped onto the S–O–R framework. As a result, this study identifies existing gaps in the current literature and suggests future research directions with specific research agendas.
•This study systematically reviews 54 research articles on immersive technology.•This study proposes a comprehensive framework for immersive technology use.•The use of immersive technology enhances user performance.•Cognitive and affective reactions to stimuli influence user performance.•The use of immersive technology can engender positive and negative consequences.
Thermal energy storage (TES) systems using phase change material (PCM) have been recognized as one of the most advanced energy technologies in enhancing the energy efficiency and sustainability of ...buildings. Now the research is focus on suitable method to incorporate PCMs with building. There are several methods to use phase change materials (PCMs) in thermal energy storage (TES) for different applications. Microencapsulation is one of the well known and advanced technologies for better utilization of PCMs with building parts, such as, wall, roof and floor besides, within the building materials. Phase change materials based microencapsulation for latent heat thermal storage (LHTS) systems for building application offers a challenging option to be employed as effective thermal energy storage and a retrieval device. Since the particular interest in using microencapsulation PCMs for concrete and wall/wallboards, the specific research efforts on both subjects are reviewed separately. This paper presents an overview of the previous research work on microencapsulation technology for thermal energy storage incorporating the phase change materials (PCMs) in the building applications, along with few useful conclusive remarks concluded from the available literature.
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