49 research outputs found
Japan's quest for energy security : risks and opportunities in a changing geopolitical landscape
For much of the 20th century, economic growth was fueled by cheap oil-based energy supply. Due to increasing resource constraints, however, the political and strategic importance of oil has become a significant part of energy and foreign policy making in East and Southeast Asian countries. In Japan, the rise of China’s economic and military power is a source of considerable concern. To enhance energy security, the Japanese government has recently amended its energy regulatory framework, which reveals high political awareness of risks resulting from the looming key resources shortage and competition over access. An essential understanding that national energy security is a politically and economically sensitive area with a clear international dimension affecting everyday life is critical in shaping a nation’s energy future
Japan\u27s Food Security Issues: A Geopolitical Challenge for Africa and East Asia?
Japan’s food self-sufficiency ratio is remarkably low compared to other industrialized nations. Growing world population, food, water, and energy shortages in combination with climate change and the rising competition for the world’s limited resources are the transnational dimensions of food and nutrition security related risks that are already affecting Japan. This paper analyzes the development and institutional context of Japanese policies related to its food security, particularly in relation to its commitments to support developing countries and to promote food security in Africa. One dimension of particular interest is the Japanese engagement in large-scale land investments in Africa. ProSAVANA, Japan’s most ambitious initiative in its development cooperation with African countries is introduced as a case study. The international context of examining Japan’s large-scale land investments highlights the fluctuation between its commitments to contribute to international development policies and the more narrow-minded pursuit of its national interests and intensified efforts to strengthen its position in international politics in relation to powerfully emerging China
HAEC-SIM: A Simulation Framework for Highly Adaptive Energy-Efficient Computing Platforms
This work presents a new trace-based parallel discrete event simulation framework designed for predicting the behavior of a novel computing platform running energy-aware parallel applications. Discrete event traces capture the runtime be- havior of parallel applications on existing systems and form the basis for the simulation. The simulation framework pro- cesses the events of the input trace by applying simulation models that modify event properties. Thus, the output are again event traces that describe the predicted application behavior on the simulated target platform. Both input and simulated traces can be visualized and analyzed with estab- lished tools. The modular design of the framework enables the simulation of different aspects such as temporal perfor- mance and energy efficiency by applying distinct simulation models e.g.: (i) A performance model for communication that allows to evaluate the target communication topology and link properties. (ii) An energy model for computations that is based on measurements of current hardware. We showcase the potential of this simulation by simulating the execution of benchmark applications to explore design al- ternatives of highly adaptive and energy-efficient computing applications and platforms
Hypericum perforatum L.-Mediated Green Synthesis of Silver Nanoparticles Exhibiting Antioxidant and Anticancer Activities
This contribution focuses on the green synthesis of silver nanoparticles (AgNPs) with a size < 100 nm for potential medical applications by using silver nitrate solution and Hypericum Perforatum L. (St John’s wort) aqueous extracts. Various synthesis methods were used and compared with regard to their yield and quality of obtained AgNPs. Monodisperse spherical nanoparticles were generated with a size of approximately 20 to 50 nm as elucidated by different techniques (SEM, TEM). XRD measurements showed that metallic silver was formed and the particles possess a face-centered cubic structure (fcc). SEM images and FTIR spectra revealed that the AgNPs are covered by a protective surface layer composed of organic components originating from the plant extract. Ultraviolet-visible spectroscopy, dynamic light scattering, and zeta potential were also measured for biologically synthesized AgNPs. A potential mechanism of reducing silver ions to silver metal and protecting it in the nanoscale form has been proposed based on the obtained results. Moreover, the AgNPs prepared in the present study have been shown to exhibit a high antioxidant activity for 2, 2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) radical cation, and super oxide anion radical and 2,2-diphenyl-1-picrylhydrazyl. Synthesized AgNPs showed high cytotoxicity by inhibiting cell viability for Hela, Hep G2, and A549 cells
Verification of Resilient Communication Models for the Simulation of a Highly Adaptive Energy-Efficient Computer
Delivering high performance in an energy-efficient manner is of great importance in conducting research in computational sciences and in daily use of technology. From a computing perspective, a novel concept (the HAEC Box) has been proposed that utilizes innovative ideas of optical and wireless chip-to-chip communication to allow a new level of runtime adaptivity for future computers, which is required to achieve high performance and energy efficiency. HAEC-SIM is an integrated simulation environment designed for the study of the performance and energy costs of the HAEC Box running communication-intensive applications. In this work, we conduct a verification of the implementation of three resilient communication models in HAEC-SIM. The verification involves two NAS Parallel Benchmarks and their simulated execution on a 3D torus system with 16x16x16 nodes with Infiniband links. The simulation results are consistent with those of an independent implementation. Thus, the HAEC-SIM based simulations are accurate in this regard. Delivering high performance in an energy-efficient manner is of great importance in conducting research in computational sciences and in daily use of technology. From a computing perspective, a novel concept (the HAEC Box) has been proposed that utilizes innovative ideas of optical and wireless chip-to-chip communication to allow a new level of runtime adaptivity for future computers, which is required to achieve high performance and energy efficiency. HAEC-SIM is an integrated simulation environment designed for the study of the performance and energy costs of the HAEC Box running communication-intensive applications.In this work, we conduct a verification of the implementation of three resilient communication models in HAEC-SIM. The verification involves two NAS Parallel Benchmarks and their simulated execution on a 3D torus system with 16x16x16 nodes with Infiniband links. The simulation results are consistent with those of an independent implementation.Thus, the HAEC-SIM based simulations are accurate in this regard
Nanoporous silica coatings on implant surfaces: characterization, stability, biocompatibility and drug release properties
Nanoporous silica coatings for drug release purposes were prepared on medical implants. As substrate, we chose Bioverit® II, which is a commercial available glass-mica ceramic implant material. The coating was prepared by a dip-coating technique in which long-chain organic molecules act as placeholders for the pores. Characterization of the coatings by scanning transmission electron microscopy and X-ray diffraction showed a disordered nanoporous system with a layer thickness of 30–150 nm. The nanoporous structure was stable for about 12 h in a typical cell culture medium and rearranged to a packing of silica nanoparticles. The coating allowed cell attachment and showed excellent biocompatibility in cell culture tests independently of the particular cell type examined. In vivo, implant-tissue interactions were examined in the middle ear in a novel mouse model. Whole genome expression profiling showed no persisting inflammatory response in the presence of the implants. Release profiles of the antibiotic ciprofloxacin demonstrated that the coating is suitable for a local drug delivery. The drug loading capacity could be drastically increased after sulfonic acid modification of the Bioverit® II surface
Rapid, energy-efficient synthesis of the layered carbide, Al<sub>4</sub>C<sub>3</sub>
The phase-pure binary aluminium carbide, Al4C3 can be synthesised in vacuo from the elements in 30 minutes via microwave heating in a multimode cavity reactor. The success of the reaction is dependent on the use of finely divided aluminium and graphite starting materials, both of which couple effectively to the microwave field. The yellow-brown powder product was characterised by powder X-ray diffraction, scanning electron microscopy/energy dispersive X-ray spectroscopy thermogravimetric-differential thermal analysis and Raman spectroscopy. Powders were composed of hexagonal single crystallites tens of microns in diameter (rhombohedral space group R[3 with combining macron]m; Z = 3; a = 3.33813(5) Å, c = 25.0021(4) Å) and were stable to 1000 °C in air, argon and nitrogen. Equivalent microwave reactions of the elements in air led to the formation of the oxycarbide phases Al2OC and Al4O4C
Green Synthesis of Silver Nanoparticles Using Hypericum perforatum L. Aqueous Extract with the Evaluation of Its Antibacterial Activity against Clinical and Food Pathogens
The rapid development of nanotechnology and its applications in medicine has provided the perfect solution against a wide range of different microbes, especially antibiotic-resistant ones. In this study, a one-step approach was used in preparing silver nanoparticles (AgNPs) by mixing silver nitrate with hot Hypericum perforatum (St. John’s wort) aqueous extract under high stirring to prevent agglomeration. The formation of silver nanoparticles was monitored by continuous measurement of the surface plasma resonance spectra (UV-VIS). The effect of St. John’s wort aqueous extract on the formation of silver nanoparticles was evaluated and fully characterized by using different physicochemical techniques. The obtained silver nanoparticles were spherical, monodisperse, face-centered cubic (fcc) crystal structures, and the size ranges between 20 to 40 nm. They were covered with a capping layer of organic compounds considered as a nano dimension protective layer that prevents agglomeration and sedimentation. AgNPs revealed antibacterial activity against both tested Gram-positive and Gram-negative bacterial strains causing the formation of 13–32 mm inhibition zones with MIC 6.25–12.5 µg/mL; Escherichia coli strains were resistant to tested AgNPs. The specific growth rate of S. aureus was significantly reduced due to tested AgNPs at concentrations ≥½ MIC. AgNPs did not affect wound migration in fibroblast cell lines compared to control. Our results highlighted the potential use of AgNPs capped with plant extracts in the pharmaceutical and food industries to control bacterial pathogens’ growth; however, further studies are required to confirm their wound healing capability and their health impact must be critically evaluate
HICFD – Highly Efficient Implementation of CFD Codes for HPC Many-Core Architectures
The objective of the German BMBF research project Highly Efficient Implementation
of CFD Codes for HPC Many-Core Architectures (HICFD) is to develop
new methods and tools for the analysis and optimization of the performance
of parallel computational fluid dynamics (CFD) codes on high performance computer
systems with many-core processors. In the work packages of the project it
is investigated how the performance of parallel CFD codes written in C can be increased
by the optimal use of all parallelism levels. On the highest level MPI is
utilized. Furthermore, on the level of the many-core architecture, highly scaling,
hybrid OpenMP/MPI methods are implemented. On the level of the processor cores
the parallel SIMD units provided by modern CPUs are exploited