In this research, a capacitance pressure sensor with graphene membrane and titanium substrate have been developed and studied as a potential robust substrate and a sensitive membrane material for micromachined devices. Mechanical lamination process combined with micromachining processes have been selected for the fabrication of the pressure sensor. Prior to the fabrication, capacitive pressure sensors based on a graphene diaphragm and titanium substrate have been designed. The fabricated pressure sensor uses a titanium substrate, a graphene film laminated with a floating movable plate, and a fixed surface micromachined back electrode of electroplated nickel. Finite element method is adopted to investigate the residual stresses formed in the process.Also, the out-of-plane strain is calculated under the pressure of the diaphragm. The sensitivity of devices manufactured using these techniques is 7.5 to 4 kPa-1, and the net capacitance change in the range of 0 to 180 kPa is 013 pF.
For the automotive application, graphene-glass composites were fabricated using E-glass fiber(GF) coated with various types of graphene nanosheets deposited by electrophoretic deposition. Graphene oxide(GO) was first synthesized using a modified Hummer’s method and its subsequent ultrasonic treatment in deionized water produced a stable stop of the GO. Glass fiber was immersed in water and GO suspension near the copper anode. The potential applied between the electrodes caused the GO to move toward the anode. In addition, the GO coated yarn was exposed to hydrazine hydrate at 100℃ to obtain a reduced graphene oxide(rGO) coating yarn. Both GO and rGO coated glass fiber yarns were used to fabricate unidirectional epoxy-based multi-scale composites by passive lay-up. The presence of a conductive rGO coating on glass fiber improves both the electrical conductivity and thermal conductivity of the composite. In addition, rGO-based epoxy-glass composites have been used to improve the dielectric constant, providing the option of using this structure for electromagnetic interference shielding.
First Mover Advantage is already well known. It is when a company gains a position in a certain market or industry, or when it establishes a strong entry barriers through a distribution channel or a monopoly of resources. It is a concept that has been attracting attention for a long time in marketing and strategy. However, although it is possible for the starter to enjoy these various benefits, it is also true that there is a corresponding price.
Therefore, the risks and costs that the starter may bear, and thus the relative benefits enjoyed by the latter, can be significant.
Late Mover Advantage and so on. The fact that latecomers can enjoy a variety of benefits as well as the profits of the starters is an important consideration that must be taken into account by many companies considering entry into the market.
In general, there is a very high risk of overinvestment in technology and market uncertainty. For example, China has skipped wired networks and went wireless, and many African countries have skipped wired communications and built infrastructure for wireless communications. In other words, companies that hastened to invest in fixed-line facilities in order to preoccupy the African telecom market are in a state of failure rather than expecting the interests of the starters.
Another thing is that the starter has to bear more risks and costs than the latter, such as the uncertainty of demand, the risk of changing consumer preferences, and the cost of training new consumers. Also, because imitation is generally less costly than development, a latecomer entering through imitation may be in a better position if patents or other technical defenses are not available. Especially, if latecomers have excellent management ability and financial power such as excellent marketing ability, it is relatively easy to catch up with the first candidate.
We investigate two abnormal CME-Storm pairs that occurred on 2014 September 10 - 12 and 2015 March 15 - 17, respectively. The first one was a moderate geomagnetic storm (Dstmin -75 nT) driven by the X1.6 high speed flare-associated CME (1267 km s−1) in AR 12158 (N14E02) near solar disk center. The other was a very intense geomagnetic storm (Dstmin -223 nT) caused by a CME with moderate speed (719 km s−1) and associated with a filament eruption accompanied by a weak flare (C9.1) in AR 12297 (S17W38). Both CMEs have large direction parameters facing the Earth and southward magnetic field orientation in their solar source region. In this study, we inspect the structure of Interplanetary Flux Ropes (IFRs) at the Earth estimated by using the torus fitting technique assuming self-similar expansion. As results, we find that the moderate storm on 2014 September 12 was caused by small-scale southward magnetic fields in the sheath region ahead of the IFR. The Earth traversed the portion of the IFR where only the northward fields are observed. Meanwhile, in case of the 2015 March 17 storm, our IFR analysis revealed that the Earth passed the very portion where only the southward magnetic fields are observed throughout the passage. The resultant southward magnetic field with long- duration is the main cause of the intense storm. We suggest that 3D magnetic field geometry of an IFR at the IFR-Earth encounter is important and the strength of a geomagnetic storm is strongly affected by the relative location of the Earth with respect to the IFR structure.