Bioenergy production and food security in Africa

Food and energy insecurities are the two greatest problems in Africa. Per capita energy consumption in Africa is less than 10% of that of United States of America while 18 out of 23 countries where starvation and malnutrition are most severe in the world are in Africa. Although various African governments have been making efforts to boast agricultural productivity, crop yields remain very low. Most governments do not even have accurate statistics on the number, location and types of crops produced by smallholder farmers that produce more than 80% of foods in Africa. This makes it very difficult to plan and implement any government support to the farmers. Sub-Saharan African countries have very high potential for production of different forms of bioenergy because the climatic conditions favour production of many energy crops. The big question has always been whether to produce bioenergy from food crops, especially in Africa with high acute food shortages. Large scale production of bioenergy may lead to competition with food crops for land, labour and other agricultural inputs. However, data from various sources indicate that Africa has abundant and underutilized arable land which can be effectively used for mass production of energy crops. Furthermore, shortage of labour cannot be a problem given the present very high rate of unemployment in most African countries. The benefits of bioenergy production in Africa outweigh the possible adverse effects on food security. Bioenergy production will create demand for, and stabilize the prices for crops, thereby increasing the earning of the farmers. This will in turn, facilitate industrialization in other sectors of economy through provision of affordable, renewable and clean energy. In order to minimize possible negative effects of bioenergy production on food security, land allocation for energy crop production can be regulated. Energy security cannot be separated from food security and the two should be seen as complimentary rather than as competitors.Key words: Bioenergy production, food security, energy

ナノバブルによるプロトプラスト機能の活性化と有用物質の高速度生産システムの開発

科学研究費助成事業 研究成果報告書：基盤研究(B)2015-2017課題番号 : 15H0456

Examination of High-Torque Sandwich-Type Spherical Ultrasonic Motor Using with High-Power Multimode Annular Vibrating Stator

Spherical ultrasonic motors (SUSMs) that can operate with multiple degrees of freedom (MDOF) using only a single stator have high holding torque and high torque at low speed, which makes reduction gearing unnecessary. The simple structure of MDOF-SUSMs makes them useful as compact actuators, but their development is still insufficient for applications such as joints of humanoid robots and other systems that require MDOF and high torque. To increase the torque of a sandwich-type MDOF-SUSM, we have not only made the vibrating stator and spherical rotor larger but also improved the structure using three design concepts: (1) increasing the strength of all three vibration modes using multilayered piezoelectric actuators (MPAs) embedded in the stator, (2) enhancing the rigidity of the friction driving portion of the stator for transmitting more vibration force to the friction-driven rotor surface, and (3) making the support mechanism more stable. An MDOF-SUSM prototype was tested, and the maximum torques of rotation around the X(Y)-axis and Z-axis were measured as 1.48 N?m and 2.05 N?m, respectively. Moreover, the values for torque per unit weight of the stator were obtained as 0.87 N?m/kg for the X(Y)-axis and 1.20 N?m/kg for the Z-axis. These are larger than values reported for any other sandwich-type MDOF-SUSM of which we are aware. Hence, the new design concepts were shown to be effective for increasing torque. In addition, we measured the transient response and calculated the load characteristics of rotation around the rotor’s three orthogonal axes

Development of electromagnetic and piezoelectric hybrid actuator system

An ordinal force-feedback device typically uses an electromagnetic motor (EMM), which provides an excellent expression of elasticity. However, it is not easy to express the sense of hardness and roughness because the response of the current is delayed due to the inductance of the armature winding. On the contrary, a piezoelectric actuator, which has a rapid response, is good at expressing the sense of hardness and roughness. Thus, if different types of actuators are used in the same actuator system (AS), the weaknesses of each type can be compensated for. In this study, as an ideal force-feedback device, a hybrid actuator system combining an EMM with an ultrasonic motor (USM) and a piezoelectric clutch/brake (piezo-clutch/brake) is proposed and examined. This AS can expand the range of representable feelings. This paper describes the construction of a hybrid AS and some experimental results of a force-feedback display. In this experiment, the feelings of roughness, friction, and elasticity were represented. The feeling of roughness was represented by the on-off control of the piezo-brake at defined positions. The feeling of friction was represented by the PID control of braking using the piezo-clutch. The feeling of elasticity was represented by two methods: the use of the EMM and brake and the use of a combination of the USM, clutch, and brake. As a result, the hardness feeling was realistically represented by the piezo-brake, and the elastic feeling was represented by either the EMM or the USM

Development of a circulation direct sampling and monitoring system for O2 and CO2 concentrations in the gas–liquid phases of shake-flask systems during microbial cell culture

Monitoring the environmental factors during shake-flask culture of microorganisms can help to optimise the initialsteps of bioprocess development. Herein, we developed a circulation direct monitoring and sampling system(CDMSS) that can monitor the behaviour of CO2and O2in the gas–liquid phases and obtain a sample without interruptingthe shaking of the culture in Erlenmeyer flasks capped with breathable culture plugs. Shake-flask culturing ofEscherichia coli using this set-up indicated that a high concentration of CO2accumulated not only in the headspace(maximum ~100 mg/L) but also in the culture broth (maximum ~85 mg/L) during the logarithmic phase (4.5–9.0 h).By packing a CO2absorbent in the gas circulation unit of CDMSS, a specialised shake-flask culture was developed toremove CO2from the headspace. It was posited that removing CO2from the headspace would suppress increasesin the dissolved CO2concentration in the culture broth (maximum ~15 mg/L). Furthermore, the logarithmic growthphase (4.5–12.0 h) was extended, the U.O.D.580 and pH value increased, and acetic acid concentration was reduced,compared with the control. To our knowledge, this is the first report of a method aimed at improving the growth of E.coli cells without changing the composition of the medium, temperature, and shaking conditions

Biosynthesis of Silver Nanoparticles Mediated by Extracellular Pigment from Talaromyces purpurogenus and Their Biomedical Applications

In recent years, green syntheses have been researched comprehensively to develop inexpensive and eco-friendly approaches for the generation of nanoparticles. In this context, plant and microbial sources are being examined to discover potential reducing agents. This study aims to utilize an extracellular pigment produced by Talaromyces purpurogenus as a prospective reducing agent to synthesize silver nanoparticles (AgNPs). Biosynthesized AgNPs were characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS), electron probe micro analyser (EPMA), and zeta potential. The pigment functional groups involved in the generation of AgNPs were investigated using Fourier transform infrared spectroscopy. TEM images showed that the generated nanoparticles were spherical, hexagonal, rod-shaped, and triangular-shaped with a particle size distribution from 4 to 41 nm and exhibited a surface plasmon resonance at around 410 nm. DLS and zeta potential studies revealed that the particles were polydispersed and stable (−24.8 mV). EPMA confirmed the presence of elemental silver in the samples. Biosynthesized AgNPs exhibited minimum inhibitory concentrations of 32 and 4 μg/mL against E. coli and S. epidermidis, respectively. Further, cytotoxicity of the AgNPs was investigated against human cervical cancer (HeLa), human liver cancer (HepG2), and human embryonic kidney (HEK-293) cell lines using 5-fluorouracil as a positive control. A significant activity was recorded against HepG2 cell line with a half-maximal inhibitory concentration of 11.1 μg/m

Inter-application communication during LHD consecutive short pulse discharge experiment

LHD short pulse experiments are executed every three minutes. After the end of the discharge, the scientists must collect, analyze, visualize the last acquired data of the discharge, and prepare for the next discharge. From the beginning, the computer environment of the LHD (Large Helical Device) experiment has been built as a network distributed system, and various computers have been used for data acquisition or physical analysis. When one program is finished on one computer, that computer must send the results in order to the other computers to run programs. Smooth communication is required in order to finish all the tasks before the next discharge. To exchange the information among the applications running on the different computers, the authors have tried various methods, such as a commercial software to share the memory over the network, simple network file sharing method, IP multicast, web interfaces, and others. The purpose of this paper is to share our experiences of trial and error to build the network distributed systems for the consecutive plasma discharge experiments

A single centre retrospective analysis of AECG classification criteria for primary Sjogren\u27s syndrome based on 112 minor salivary gland biopsies in a Japanese population.

OBJECTIVE: To assess the usefulness and performance of the American European Consensus Group (AECG) criteria based on minor salivary gland biopsy (MSGB) in Japanese patients with primary SS. METHODS: Among 208 MSGB cases, we retrospectively selected 112 subjects who satisfied the complete set of AECG classification criteria. Of the 112 subjects studied, 63 primary SS patients and 49 non-SS group subjects were classified according to the AECG criteria. The contribution of subjective and objective components was statistically analysed. RESULTS: Sex, dry eye, Saxon test, Schirmer\u27s test, anti-SSA/Ro antibody, MSGB grading and sialography statistically contributed to the diagnosis. Multiple logistic regression analysis showed that positive MSGB [odds ratio (OR) 105; 95% CI 13, 849), positive anti-SSA/Ro antibody (OR 96; 95% CI 10, 923), a positive Saxon test (OR 46; 95% CI, 6, 340) and the existence of dry eye (OR 8, 95% CI 2, 43) were associated with the diagnosis of primary SS. Among the components of the AECG criteria, MSGB and anti-SSA/Ro antibody were very strong contributors. Furthermore, the abnormal-finding positive rate in sialography significantly correlated with MSGB grading (P-value for trend = 0.0006), although other subjective and objective components were not associated with MSGB grading. CONCLUSION: The usefulness of the AECG criteria for Japanese primary SS patients was confirmed