Energy harvesting from human foot motion is attractive for the electrical power source of wearable sensors. For human foot motion, three types of energies are available: bending in the sole, heel ...strike and swing motion. In this study, the magnitudes of these energies were analyzed by dynamic measurements using various sensors. Then, appropriate piezoelectrics and device structure for the energy harvesting were discussed for each energy. From these results, it was concluded that utilizing bending in the sole and organic piezoelectrics such as PVDF is the best way for the energy harvesting from walking.
We have proposed that BiFeO3 films are suitable for piezoelectric vibration energy harvesting applications, because of the low dielectric permittivity and excellent ferroelectricity. In this paper, ...the improvement of the piezoelectric properties of the domain-engineered BiFeO3 films was discussed. The (100) epitaxial films were prepared at growth temperatures between 500 and 650°C on Nb-doped (100) SrRuO3 single crystals. The combinatorial sputtering method was employed in order to prevent Bi defects during high-temperature deposition. The domain structure and e31,f piezoelectric coefficients of the films were characterized by a piezoelectric force microscopy and direct piezoelectric response, respectively. The highest e31,f coefficient of -4.3 C/m2 and figures of merit of 14 GPa were obtained in the film deposited at 600°C, which has the highest domain wall density. This suggests that the introduction of the domain walls is effective to enhance the piezoelectric properties of BiFeO3 films.
Disrupted in schizophrenia 1 (DISC1), a genetic risk factor for multiple serious psychiatric diseases including schizophrenia, bipolar disorder and autism, is a key regulator of multiple neuronal ...functions linked to both normal development and disease processes. As these diseases are thought to share a common deficit in synaptic function and architecture, we have analyzed the role of DISC1 using an approach that focuses on understanding the protein-protein interactions of DISC1 specifically at synapses. We identify the Traf2 and Nck-interacting kinase (TNIK), an emerging risk factor itself for disease, as a key synaptic partner for DISC1, and provide evidence that the DISC1-TNIK interaction regulates synaptic composition and activity by stabilizing the levels of key postsynaptic density proteins. Understanding the novel DISC1-TNIK interaction is likely to provide insights into the etiology and underlying synaptic deficits found in major psychiatric diseases.
With huge developments of science and engineering especially information and communication technology, loop heat pipe (LHP), a passive two-phase cooling device, can be considered one of the promising ...heat transfer devices with effective thermal conductivity. In this study, a new evaporator structure is fabricated and experiments are carried out horizontal and gravity assisted operating condition. Water is selected as working fluid while sintered stainless steel wick is installed as capillary structure of LHP. The Results show that, gravity assisted LHP has higher performance compared to horizontal LHP and it can keep stable operating state at heat load 520 W without dry out phenomenon.
Environmental vibrations include random oscillations of different frequencies and amplitudes. Energy harvesters recover the energy associated with these vibrations. Properties of the vibrations and ...output power are characterized for cantilever-type piezoelectric vibration energy harvesters using (100)-orientated BiFeO3 films subject to both ideal and random oscillations. The displacement and output power under random oscillations were smaller than those under ideal oscillations. This decrease originates with the decreasing acceleration of the fundamental wave with the spurious component having little influence on the resonance response.
Little is known about the specific signaling roles of Rap2, a Ras family small GTP-binding protein. In a search for novel Rap2-interacting proteins by the yeast two-hybrid system, we isolated isoform ...3 of the human mitogen-activated protein kinase kinase kinase kinase 4 (MAP4K4), a previously described but uncharacterized isoform. Other isoforms of MAP4K4 in humans and mice are known as hematopoietic progenitor kinase (HPK)/germinal center kinase (GCK)-like kinase and Nck-interacting kinase, respectively. MAP4K4 belongs to the STE20 group of protein kinases and regulates c-Jun N-terminal kinase (JNK). MAP4K4 interacted with Rap2 through its C-terminal citron homology domain but did not interact with Rap1 or Ras. Interaction with Rap2 required the intact effector region of Rap2. MAP4K4 interacted preferentially with GTP-bound Rap2 over GDP-bound Rap2 in vitro. In cultured cells, MAP4K4 colocalized with Rap2, while a mutant MAP4K4 lacking the citron homology domain failed to do so. Furthermore, Rap2 enhanced MAP4K4-induced activation of JNK. These results suggest that MAP4K4 is a putative effector of Rap2 mediating the activation of JNK by Rap2.
Japan is a mountainous country comprising several islands, in which mountains occupy 70% of the entire land. Therefore, numerous transmission line towers have been constructed in the shallow space of ...steep mountainous areas. In such construction, monorails and/or cableways are generally used to transport materials and equipment to the construction site instead of using a construction road, as the former method is more economically viable. However, with this method, drill rigs or vertical shaft sinking machines cannot be transported to the site. Four small-diameter vertical shafts of 2.5 or 3.0 m as the foundation for high-voltage transmission line towers in mountainous areas are traditionally constructed manually in Japan. Over the past two decades, however, dangerous and poor environmental conditions for workers regarding the manual construction of these small-diameter vertical shafts have become a major problem. Meanwhile, owing to the poor environmental conditions of small-diameter vertical shafts to be constructed in the shallow space of steep mountainous areas, a decrease has occurred in the number of young workers entering these projects. Namely, the construction of transmission line towers with using the manually traditional small-diameter vertical shafts is becoming difficult in Japan from abovementioned problems. Hence development of a new technology to solve the problems is necessary for Japan’s economic growth. With this knowledge, the authors have developed a new small-diameter vertical shaft construction system, in which workers do not have to enter the vertical shaft during construction, as machines are used instead. The applicability of the proposed system was confirmed by means of the construction of three actual vertical shafts at two construction sites, as well as in factory and field tests. The applicability and details of the final proposed system are summarized in this paper.
Piezoelectric vibration energy harvesters (VEHs) with unimorph structure have been developed using Si micro-electrical mechanical systems (MEMS) technology. Since we revealed that (100) epitaxial ...BiFeO3 (BFO) piezoelectric films have high figure-of-merit on energy conversion, (100)-oriented BFO films have been prepared on (100)-oriented LaNiO3 bottom electrodes by the sol-gel method. We fabricated the piezoelectric VEHs using BFO films with resonance frequencies of ~100 Hz. The maximum output power density of these VEHs was determined to be 10.5 μWmm−3G−2 (G=9.8 ms−2) at a load resistance of 1 MΩ, which exceeds or is comparable to those of the best-performing VEHs using other piezoelectric films.
Tuning the carrier concentration is essential for semiconducting materials to apply optoelectronic devices. Molybdenum disulfide (MoS2) is a semiconducting material composed of atomically thin (∼0.7 ...nm thickness) layers. To dope thin MoS2, instead of using conventional atom/ion injection processes, a surface charge transfer method was successfully applied. In this study, we report a simple preparation method of a molecular dopant applicable to the doping process. The method follows a previous report for producing a molecular dopant, benzyl viologen (BV) which shows electron doping to MoS2. To prepare dopant BV molecules, a reduction process with a commercially available divalent BV by sodium borohydride (NaBH4) is required; however, the reaction requires a large consumption of NaBH4. NaBH4 drastically reacts with the solvent water itself. We found a reaction process of BV in an organic solvent, N,N’-dimethylformamide (DMF), by adding a small amount of water dissolving the divalent BV. The reaction is mild (at room temperature) and is autonomous once DMF comes into contact with the divalent BV aqueous solution. The reaction can be monitored with a UV-Vis spectrometer, and kinetic analysis indicates two reaction steps between divalent/monovalent/neutral viologen isomers. The product was soluble in toluene and did not dissolve in water, indicating it is similar to the reported dopant BV. The synthesized molecule was found to act as a dopant for MoS2 by applying a metal-oxide-semiconductor field-effect-transistor (MOSFET) structure. The process is a general method and applicable to other viologen-related dopants to tune the electronic structure of 2D materials to facilitate generating atomically thin devices.
Mental health has suffered considerably as a result of advancing time and technological developments. Poor quality of sleep affects people of all ages, and non-pharmacological remedies are becoming ...increasingly important. Nearly 60% of all undergraduate students are reported to have a poor quality of sleep, with 7.7% fitting the criteria for insomnia. Sleep deprivation is found to affect the immune function, brain maturation, development of the body, metabolic process, and cognition, as well as maintaining normal homeostasis of the body. Sleep quality and quantity have a severe influence on learning and memory and thus a major influence on students’ quality of life. Brain gym exercises are a formidable contender in this race. Still, further study is required before a solid conclusion can be formed on its value as an intervention, so to evaluate the effect of brain gym exercises as a non-pharmacological measure, this study was conducted with a total of 65 participants based on the inclusion and exclusion criteria with the duration of practice as five days in a week with a session of 25 minutes with adequate intervals. An insomnia rating scale (IRS) is used to get the desired population for giving the intervention, along with the Pittsburgh Sleep Quality Index (PSQI). This study was conducted at the Physiotherapy College of Wardha. The results were given by statistical analysis using descriptive and inferential statistics. The data analysis depicted that after the brain gym activity intervention, there was a marked reduction in the score of PSQI, suggesting significant improvement in their sleep quality, and it can be used as non-pharmacological management for mild to moderate insomnia students.
PDF
