Current trends and innovations affecting the potential for a widespread adoption of electric buses - A comparative case study of 22 cities in the Americas, Asia-Pacific and Europe

Electric buses have environmental, economic, and health benefits, which many cities want to achieve by transitioning their fleets. However, the actual worldwide electric bus adoption is geographically uneven and limited in scale, and few studies analyzed what factors can potentially shape a wider adoption. The paper is based on real world experiences, and applies a comparative multi-case study to 22 cities in 14 countries. A common framework is used for analysis, which includes non-reimbursable funds, investment capital, and legal arrangements. Results show that four key factors are shaping the widespread adoption of electric buses. Firstly, public and private grants, which, when dedicated to cleaning the fleet, appears as a strong factor underpinning existing clean bus systems. Secondly, less costly sources of financing can reduce financial risks and enable more adoption, and it is where innovation can happen. Also, innovative ways of structuring contractual implementation effectively connect stakeholders and involve third-party players, which leads to shared and mitigated risks, increased efficiency and improved performance. In addition, some other elements outside of the business model framework also prove to be enabling the adoption of electric buses

Mechanical properties of freely suspended semiconducting graphene-like layers based on MoS2

We fabricate freely suspended nanosheets of molybdenum disulphide (MoS2) which are characterized by quantitative optical microscopy and high-resolution friction force microscopy. We study the elastic deformation of freely suspended nanosheets of MoS2 using an atomic force microscope. The Young's modulus and the initial pre-tension of the nanosheets are determined by performing a nanoscopic version of a bending test experiment. MoS2 sheets show high elasticity and an extremely high Young's modulus (0.30 TPa, 50% larger than steel). These results make them a potential alternative to graphene in applications requiring flexible semiconductor materials

Elastic properties of freely suspended MoS2 nanosheets

We study the elastic deformation of few layers (5 to 25) thick freely suspended MoS2 nanosheets by means of a nanoscopic version of a bending test experiment, carried out with the tip of an atomic force microscope. The Young's modulus of these nanosheets is extremely high (E = 0.33 TPa), comparable to that of graphene oxide, and the deflections are reversible up to tens of nanometers.Comment: 11 pages, 7 figures (including supplementary information

Microseismic joint location and anisotropic velocity inversion for hydraulic fracturing in a tight Bakken reservoir

To improve the accuracy of microseismic event locations, we developed a new inversion method with double-difference constraints for determining the hypocenters and the anisotropic velocity model for unconventional reservoirs. We applied this method to a microseismic data set monitoring a Middle Bakken completion in the Beaver Lodge area of North Dakota. Geophone arrays in four observation wells improved the ray coverage for the velocity inversion. Using an accurate anisotropic velocity model is important to correctly assess the height growth of the hydraulically induced fractures in the Middle Bakken. Our results showed that (1) moderate-to-strong anisotropy exists in all studied sedimentary layers, especially in the Upper and Lower Bakken shale formations, where the Thomsen parameters (ϵ and γ) can be greater than 0.4, (2) all the events selected for high signal-to-noise ratio and used for the joint velocity inversion are located in the Bakken and overlying Lodgepole formations, i.e., no events are detected in the Three Forks formation below the Bakken, and (3) more than half of the strong events are in two clusters at approximately 100 and 150 m above the Middle Bakken. Reoccurrence of strong, closely clustered events suggested activation of natural fractures or faults in the Lodgepole formation. The sensitivity analysis for the inversion results showed that the relative uncertainty in parameter δ is larger than other anisotropy parameters. The microseismic event locations and the anisotropic velocity model are validated by comparing synthetic and observed seismic waveforms and by S-wave splitting.Shell Oil Compan

Environmental description

Environmental description is the description of general, physical, personal and social space and action, where visual, auditory and other sensory information is shared with the receiver in spoken, written or sign language, either vocally, i.e. producing sounds or in another form (pointing, touching, drawing). It can be divided into the expression of basic characteristics, basic description, precise and extended description, and it can be carried out physically on the spot (close description) or far away from the target (distant description). Description can be carried out spontaneously in real time, in joint action systematically i.e. pre-prepared description or it can be recorded beforehand as a text format, or as consecutive i.e. a postponed description after the event. The target group may be one person or a group. In addition to verbal description, environmental description can be produced with various sounds, such as vocalization without words or other sources of sounds e.g. musical instruments. Interaction in a situation between the describer and the receiver may be a one-way description or a dialogue. It can further be divided into functional dialogue, reciprocal description supporting sensory perceptions, telling and pointing in front of the target, reciprocal description by drawing or through movements and the exploration of objects. In detailed descriptions the main subjects are followed by details. Description can be classified according to the size of the space that is extensive, large, in a room or nearby

Mechanical properties of freely suspended atomically thin dielectric layers of mica

We have studied the elastic deformation of freely suspended atomically thin sheets of muscovite mica, a widely used electrical insulator in its bulk form. Using an atomic force microscope, we carried out bending test experiments to determine the Young's modulus and the initial pre-tension of mica nanosheets with thicknesses ranging from 14 layers down to just one bilayer. We found that their Young's modulus is high (190 GPa), in agreement with the bulk value, which indicates that the exfoliation procedure employed to fabricate these nanolayers does not introduce a noticeable amount of defects. Additionally, ultrathin mica shows low pre-strain and can withstand reversible deformations up to tens of nanometers without breaking. The low pre-tension and high Young's modulus and breaking force found in these ultrathin mica layers demonstrates their prospective use as a complement for graphene in applications requiring flexible insulating materials or as reinforcement in nanocomposites.Comment: 9 pages, 5 figures, selected as cover of Nano Research, Volume 5, Number 8 (2012