Search results for "Miniaturization"
showing 10 items of 44 documents
New prototypes for the isolation of the anodic chambers in microbial fuel cells
2016
This work has been focused on the assessment of new prototypes of MFC in which a more strict separation of the anode and cathode compartments is looked for, in order to attain strict anaerobic conditions in the anode chamber and hence, avoid lack of efficiency due to the prevalence of non-electrogenic competing microorganisms and to optimize composition of the anolyte and catholyte. A cylinder reactor with an inner chamber with graphite bars acting as anodes and the outer one with a stainless steel tube acting as cathode was used in three different configurations and results obtained during lifetests are compared in terms of electricity production, cathode oxygen consumption and anode COD d…
Porous organic cage compounds as highly potent affinity materials for sensing by quartz crystal microbalances.
2012
Porosity makes powerful affinity materials for quartz crystal microbalances. The shape-persistent organic cages and pores create superior affinity systems to existing ones for direct tracing of aromatic solvent vapors. A shape and size selectivity for the analytes is observed. These organic cages can be processed to thin films with highly reproducible sensing properties.
Imaging the Magnetic Reversal of Isolated and Organized Molecular-Based Nanoparticles using Magnetic Force Microscopy
2015
In the race towards miniaturization in nanoelectronics, magnetic nanoparticles (MNPs) have emerged as potential candidates for their integration in ultrahigh-density recording media. Molecular-based materials open the possibility to design new tailor-made MNPs with variable composition and sizes, which benefit from the intrinsic properties of these materials. Before their implementation in real devices is reached, a precise organization on surfaces and a reliable characterization and manipulation of their individual magnetic behavior are required. In this paper, it is demonstrated how molecular-based MNPs are accurately organized on surfaces and how the magnetic properties of the individual…
Nanowires: A route to efficient thermoelectric devices
2019
Miniaturization of electronic devices aims at manufacturing ever smaller products, from mesoscopic to nanoscopic sizes. This trend is challenging because the increased levels of dissipated power demands a better understanding of heat transport in small volumes. A significant amount of the consumed energy in electronics is transformed into heat and dissipated to the environment. Thermoelectric materials offer the possibility to harness dissipated energy and make devices less energy-demanding. Heat-to-electricity conversion requires materials with a strongly suppressed thermal conductivity but still high electronic conduction. Nanowires can meet nicely these two requirements because enhanced …
Development of a module of stacks of air-breathing microbial fuel cells to light-up a strip of LEDs
2018
Abstract This work focuses on scaling-up of the microbial fuel cells technology according to the principle of miniaturization and multiplication. Seven stacks of 16 mini-MFCs (electrodic area of 0.866 cm2) were built up leading to a big module of 112 MFCs. The electrical connection among the MFCs in the stacks and among the stacks into the modules was optimized in order to implement this technology. Results show that 1 MFC generates 1.22 mW while the optimization of the electric connection in order to achieve the maximum power results in 6.62 mW compared to the theoretical 182 mW, indicating the existence of large energy losses in the system. However, to light a LED there is not a threshold…
On the staking of miniaturized air-breathing microbial fuel cells
2018
Abstract This work focuses on the scale-up of the MFCs by miniaturization and multiplication strategy. Performances of five stacks containing 1, 2, 5, 8 and 16 MFCs were compared. Each stack was evaluated under individual, parallel and series electrical connection as well as for cascade or individual hydraulic connection. Cascade feeding mode with a tank per stack favours the COD removal when the number of MFCs in the stack increases. However, despite operating without COD limitations, the energy production was disadvantaged. By changing the feeding system of a tank per stack into an individual tank per MFC, the performance of the whole stack enhances considerably. Stacking in series can in…
Comparison of two portable solid state detectors with an improved collimation and alignment device for mammographic x-ray spectroscopy.
2006
We describe a portable system for mammographic x-ray spectroscopy, based on a 2 X 2 X 1 mm3 cadmium telluride (CdTe) solid state detector, that is greatly improved over a similar system based on a 3 X 3 X 2 mm3 cadmium zinc telluride (CZT) solid state detector evaluated in an earlier work. The CdTe system utilized new pinhole collimators and an alignment device that facilitated measurement of mammographic x-ray spectra. Mammographic x-ray spectra acquired by each system were comparable. Half value layer measurements obtained using an ion chamber agreed closely with those derived from the x-ray spectra measured by either detector. The faster electronics and other features of the CdTe detecto…
Particle packed columns and monolithic columns in high-performance liquid chromatography-comparison and critical appraisal
2007
The review highlights the fundamentals and the most prominent achievements in the field of high-performance liquid chromatography (HPLC) column development over a period of nearly 50 years. After a short introduction on the structure and function of HPLC columns, the first part treats the major steps and processes in the manufacture of a particle packed column: synthesis and control of particle morphology, sizing and size analysis, packing procedures and performance characterization. The next section is devoted to three subjects, which reflect the recent development and the main future directions of packed columns: minimum particle size of packing, totally porous vs. core/shell particles an…
Miniaturization of rectangular microstrip patches using genetic algorithms
2002
This paper presents a new procedure for the miniaturization of rectangular microstrip patches based on genetic algorithms. The shape of a typical rectangular patch is modified in order to reduce its resonance frequency keeping the physical volume of the antenna constant. As an example, the resonance frequency of a square microstrip patch is reduced from 3 to 1.8 GHz. The patch is divided in 9/spl times/9 square cells. The genetic algorithm optimization procedure is subsequently used to remove some of the metallic cells. To validate the procedure an antenna prototype has been fabricated and tested. Good agreement is obtained between theoretical and experimental results.
Assessment of Tumor Development and Wound Healing Using Endoscopic Techniques in Mice
2010
Mouse models of intestinal inflammation and colon cancer are valuable tools to gain insights into the pathogenesis of the corresponding human diseases. Recently, in vivo mouse endoscopy has been developed, allowing not only the high-resolution monitoring and scoring of experimental disease development, but also enables the investigator to perform manipulations, including local injection of reagents or the taking of biopsies for molecular and histopathologic analyses. Chromoendoscopic staining with methylene blue enables visualization of the crypt structure and allows discrimination between inflammatory and neoplastic changes. The development of endoscopic techniques in live mice opened new …