Giant thermoelectric effect in graphene-based topological insulators with nanopores

Designing thermoelectric materials with high figure of merit $ZT=S^2 G T/\kappa$ requires fulfilling three often irreconcilable conditions, i.e., the high electrical conductance $G$, small thermal conductance $\kappa$ and high Seebeck coefficient $S$. Nanostructuring is one of the promising ways to achieve this goal as it can substantially suppress lattice contribution to $\kappa$. However, it may also unfavorably influence the electronic transport in an uncontrollable way. Here we theoretically demonstrate that this issue can be ideally solved by fabricating graphene nanoribbons with heavy adatoms and nanopores. These systems, acting as a two-dimensional topological insulator with robust helical edge states carrying electrical current, yield a highly optimized power factor $S^2G$ per helical conducting channel. Concurrently, their array of nanopores impedes the lattice thermal conduction through the bulk. Using quantum transport simulations coupled with first-principles electronic and phononic band structure calculations, the thermoelectric figure of merit is found to reach its maximum $ZT \simeq 3$ at $T \simeq 40$ K. This paves a way to design high-$ZT$ materials by exploiting the nontrivial topology of electronic states through nanostructuring.Comment: 7 pages, 4 figures; PDFLaTe

THE EFFECTS OF KINESIO TAPING ON RATE OF FORCE DEVELOPMENT IN SQUAT JUMP AND COUNTER MOVEMENT JUMP

Kinesio tape (KT) has been widely used to prevent muscle pain and to improve strength and sports performance. Therefore, the aim of this study was to investigate the effect of KT in rate of force development (RFD). To compare with KT or non-KT in squat jump (SJ) and counter movement jump (CMJ). The RFD was improved or not improved by using KT. Six healthy female was recruited in this study. The kistler force plate was used to measure the RFD. There is no significant improve in SJ and CMJ. The results showed that KT did not affect RFD

THE EFFECTS OF QUADRICEPS TAPING AND NOWTAPING APPROCHES ON COUNTERMOVEMENT JUMP PERFORMANCE

Kinesio is one of the most common adhesive therapeutic tapes. Expect for clinical applications, kinesio claims to be able to enhance muscle activity performance. The purpose of this study was to investigate the effect of kinesio taping on quadriceps during a maximal counter-movement jump. Six healthy men was recruited in this study (Height: 173.8 k 4.2 em; Weight: 68.8 k 7.3 kg; Age: 22.9 k 2.3 yrs ). The kistler force plate was used to measure the jump height, takeoff force and landing force. No significant differences between two groups. The results showed that kinesio tape did not affect muscle activity and ground recreation force, jumping height and landing force

Improving The Performance of Inventory Control – Taking W Company as an Example

The W company is facing a problem that their demand is intermittent. Because intermittent demand is difficult to predict, there are some models being created to deal with it. Using these models, such as Bootstrapping, Croston’s method, and Discreteauto-regressive-moving-average model, to predict and compare with the current one if any of them outperforms