Thermoelectric Generation Using Water Lenses

A solar light concentrator composed of water and plastic transparent film has been designed. This flexible lens design can trace the solar movement through control of the tensile stress and amount of water, and concentrate the solar energy onto the thermoelectric (TE) module surface. An experimental water lens was constructed, and the concentrated intensity was monitored by a photodiode as a function of x–z position; For example, when 3.0 kg water was filled and tension of 69.0 N/m was applied to the transparent vinyl sheet, the concentration ratio was evaluated as the maximum of 28.0 at a depth of 657 mm from the water lens bottom surface. TE generation was tested to show the validity of the water lens. The surface condition of the receiver was found to be critical.     

Development of a whole‐body haptic sensor with multiple supporting points and its application to a manipulator

This paper proposes a whole‐body haptic sensing system that has multiple supporting points between the body frame and the end‐effector. The system consists of an end‐effector and multiple force sensors. Using this mechanism, the position of a contact force on the surface can be calculated without any sensor array. A haptic sensing system with a single supporting point structure has previously been developed by the present authors. However, the system has drawbacks such as low stiffness and low strength. Therefore, in this study, a mechanism with multiple supporting points was proposed and its performance was verified. In this paper, the basic concept of the mechanism is first introduced. Next, an evaluation of the proposed method, performed by conducting some experiments, is presented. © 2012 Wiley Periodicals, Inc. Electr Eng Jpn, 182(1): 48‐56, 2013; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.22310     

Trends in research foci in life science fields over the last 30 years monitored by emerging topics

We report here a simple method to identify the ‘emerging topics’ in life sciences. First, the keywords selected from MeSH terms on PubMed by filtering the terms based on their increment rate of the appearance, and, then, were sorted into groups dealing with the same topics by ‘co-word’ analysis. These topics were defined as ‘emerging topics’. The survey of the emerging keywords with high increment rates of appearance between 1972 to 2006 showed that emerging topics changed dramatically year by year, and that the major shift of the topics occurred in the late 90s; the topics that cover technical and conceptual aspects in molecular biology to the more systematic ‘-omics’-related and nanoscience-related aspects. We further investigated trends in emerging topics within various sub-fields in the life sciences.     

Ex Vivo Expanded and Activated Natural Killer Cells Prolong the Overall Survival of Mice with Glioblastoma-like Cell-Derived Tumors

Glioblastoma (GBM) is the leading malignant intracranial tumor and is associated with a poor prognosis. Highly purified, activated natural killer (NK) cells, designated as genuine induced NK cells (GiNKs), represent a promising immunotherapy for GBM. We evaluated the anti-tumor effect of GiNKs in association with the programmed death 1(PD-1)/PD-ligand 1 (PD-L1) immune checkpoint pathway. We determined the level of PD-1 expression, a receptor known to down-regulate the immune response against malignancy, on GiNKs. PD-L1 expression on glioma cell lines (GBM-like cell line U87MG, and GBM cell line T98G) was also determined. To evaluate the anti-tumor activity of GiNKs in vivo, we used a xenograft model of subcutaneously implanted U87MG cells in immunocompromised NOG mice. The GiNKs expressed very low levels of PD-1. Although PD-L1 was expressed on U87MG and T98G cells, the expression levels were highly variable. Our xenograft model revealed that the retro-orbital administration of GiNKs and interleukin-2 (IL-2) prolonged the survival of NOG mice bearing subcutaneous U87MG-derived tumors. PD-1 blocking antibodies did not have an additive effect with GiNKs for prolonging survival. GiNKs may represent a promising cell-based immunotherapy for patients with GBM and are minimally affected by the PD-1/PD-L1 immune evasion axis in GBM.     

Multipoint cure monitoring of CFRP laminates using a flexible matrix sensor

Since a carbon fiber reinforced plastic (CFRP) structure is complicated in the adoption of integral molding, local molding faults such as under curing and dry spots are liable to occur. To solve this problem, the distribution of the degree of curing for the entire composite structure must be measured. In the present study, we propose a patch-type flexible matrix sensor based on permittivity measurements. Multiple electrodes and wirings are readily fabricated simultaneously using a photolithographic process. Moreover, the sensor has only m + n wirings for m × n sensors, and is thereby suitable for multipoint cure monitoring. We also constructed a method for estimating the degree of curing considering the effect of frequency dependence of the permittivity of resin and viscosity variation due to temperature change. Experiments of multipoint cure monitoring are carried out using a CFRP plate and an actual aircraft structure. As a result, we confirmed the effectiveness of this method by comparing with results using a conventional differential scanning calorimeter.     

Size distribution measurement and separation of ethanol cluster ion beams

The distributions of the number of molecules per cluster (cluster size) of ethanol cluster ion beams were measured by the time-of-flight method. The cluster sizes at the peak and minimum tail (minimum size) of the distribution increased with increase of the retarding voltage. A difference appeared between the measured minimum size and the calculated values using a formula based on the early measurements on the velocity distributions of gas clusters.     

A Hydrogen Management Method in Residential Distributed Generation Systems with Photovoltaic Cells and Hydrogen‐Storage Type Fuel Cells

Recently, renewable energy has been attracting attention as a result of global warming and the depletion of fossil fuels. Photovoltaic (PV) systems have spread rapidly around the world because they generate electric power quietly and can be installed in many places. The output power generated in a PV system fluctuates with changes in solar irradiance and panel temperature. The reverse flow of surplus power in output spikes may have a negative effect on electric power quality, such as on the frequency and voltage in a power system. A residential distributed generation (DG) system composed of a fuel cell (FC) unit, an electrolyzer (EL) unit, and a PV system has been proposed in order to resolve these problems. In order to operate this system without interruption, the hydrogen storage volume must be managed. This paper proposes a novel hydrogen management method for a residential DG system with PV cells and hydrogen‐storage type FCs. The hydrogen storage volume is maintained at the preset frequency by operating the FC unit and the EL unit. Models of the PV, FC, and EL were constructed for a simulation. In the simulation, we showed that the proposed management method is viable for a residential DG system with PV cells and hydrogen‐storage FCs.     

Posture Control for Personal Mobility Robot Using Feedback Compensation with Unstable Pole

This paper presents a novel posture control approach using feedback compensation with an unstable pole. For a narrow and small personal mobility robot (PMR), this is needed in order to control its posture for achieving quick turning and high acceleration. However, in the conventional control approach that uses the posture angle as a controlled variable, the zero moment point (ZMP) does not settle to the desired point in the following cases: an unknown disturbance force given to the PMR, a fluctuation in the center of gravity of the PMR, and a change in the conditions between the tires and the road surface. In this paper, a novel control method using feedback compensation with an unstable pole is proposed to achieve the desired ZMP in the steady state. The proposed controller changes the control input for the actuator of posture control to zero in order to achieve the desired posture angle. The effectiveness of the proposed approach is verified through experiments using a prototype of the PMR.