Bruno Camps-Raga

Germination rate studies of soybean under static and low-frequency magnetic fields

A Helmholtz coil was designed and characterized to study the effects of magnetic fields on the germination rate of soybeans. The coil provides a uniform field in a large area such that all the seeds are equally exposed to radiation. An in-house computer code was developed to study the field intensity, specifically the cross-sectional area of uniform field. Experimental results indicate that soybeans grown under static low intensity and super low frequency magnetic fields show improved growth and germination rates when compared to those in the control group. Soybean has potential applications as a renewable energy source for biofuels.

OPTIMIZED SIMULATION ALGORITHMS FOR FRACTAL GENERATION AND ANALYSIS

A set of algorithms, speciflcally developed to facilitate an efiective modeling of fractal-boundary microstrip antennas in the analysis of such structures through numerical electromagnetic (EM) solvers is presented in this paper. A fractal generator based on the implementation of an Iterated Function System (IFS) produces the geometry specifled in accordance with the user-deflned input parameters. The structure is created through a solver-speciflc interface and is thus applicable to a commercially available EM simulation suite. The generation of speciflc shapes through these algorithms provides a ∞exible method to study difierent geometries without the need to modify either the interface or the solver. Three structures based on the Minkowski fractal obtained through these techniques have been studied using two EM solvers for comparison. The frequency-domain results show good agreement between the two solvers, thus validating the algorithms implemented. Complex structures with higher iterations can be studied using these algorithms.

Effects of nanosecond pulsed electric fields on the human prostate cancer cell line LNCaP

The effects of nanosecond pulsed electric fields (nsPEF) on the human prostate cancer cell line LNCaP was investigated for changes in protein and DNA concentrations as well as for the 11beta hydroxysteroid dehydrogenase type 2 (11betaHSD2) enzyme activity. Electric fields with intensities of 32.5 kV/cm and pulse widths of 60 ns were applied to cancer cells in trains of 1, 5, and 10 pulses. Protein concentrations were determined through a Bio-Rad DC protein assay, while Hoechst 33258 was used to quantify DNA concentrations. The analyses showed that protein concentrations decreased by 18.77% and 19.04% for 1 and 10 pulses, respectively, while DNA concentrations decreased by 5.29%, 8.95%, and 18.36% for 1, 5, and 10 pulses, respectively, as compared to control groups. The 11betaHSD2 enzyme activity in LNCaP cells also decreased following exposure, thus supporting our initial hypothesis that ultrashort pulses affect intracellular structures; thus, a decrease in the enzyme activity could result in enhancing the anti-proliferative actions of glucocorticoids.

Optimization of soybeans as a biofuel resource through germination studies under electromagnetic fields

Soybean seeds codenamed Magellan that can be used as future resources of biofuels were separated into five groups and exposed with electromagnetic fields inside the test chamber with different intensity levels of power, frequency, and time. Seeds after exposure treatments were germinated according to the procedures established by the American Association of Seed Analysts. A hundred seeds from each group were germinated according to these procedures and the percent germination was recorded. Another ten seeds from each treatment, including controls, were manually crushed and placed in separate test tubes for fatty acid analyses. The processed results from the greenhouse confirm effects of electromagnetic fields on the soybean germination. In addition, it is possible that soybean lines with different genetic backgrounds may respond differently to electromagnetic fields in terms of percent seed germination.

Near-Field Microwave Imaging Techniques for Object Detection and Shape Reconstruction

A near Held, frequency-synthesized microwave pulse method for the detection, imaging and reconstruction of an object has been analyzed. The procedure describes a detection technique called the single-probe detection (SPD) method, where a single probe is used to reconstruct an objects shape and determine its location in two dimensions. For a complete image mapping and reconstruction, a cylindrical scan method involving a rotational and a planar scan is used. A planar scanning alone cannot provide image reconstruction.

A comparative study of numerical and experimental evaluation of RF-induced heating for an endovascular stent-graft at 1.5T and 3T

The radiofrequency (RF) electromagnetic (EM) environment generated in the bore of a magnetic resonance imaging (MRI) scanner may induce power deposition in the surroundings of metallic implants worn by patients. This heating, which may in turn lead to local increases in tissue temperature, is usually quantified in terms of a specific absorption rate (SAR). SAR values in the vicinity of an implant are, in fact, directly linked to high temperature increases at the object [1]. This effect is investigated in this work by comparing simulated SAR peak values near an endovascular stentgraft with experimental measurements of temperature rise. The study was performed at nominal static magnetic fields of 1.5 and 3 T, which correspond to operating frequencies of nominal 64 and 128 MHz, respectively.

Topological model for energy transmission through cells in a cuvette

Summary form only given as follows. Simulating a cells response to applied pulsed electromagnetic fields is difficult because of the great variations of the dimensions involved in the mesh generation process. The membrane thickness is in the nanometer range as compared to the cell dimension which is in microns. For successful simulation the number of mesh points and consequently the computational time is large since the mesh generated must conform to the lowest dimensions (sub-nanometer). Further, the simulations become more difficult and complex when a large number of cells are involved, such as those in a cuvette solution between two electrodes for pulsed application studies. In this presentation we discuss an alternative simulation method based on the electromagnetic topology (EMT) technique. This method integrates the multi-conductor transmission line network (MTLN) simulations (with experimental data at any junctions, if available) in a piecewise fashion. As a result the analysis of a system that has complex interaction paths, just like the number of cells suspended in a solution between electrodes can be performed easily. Here the given system is decomposed into manageable sizes of sub-volumes where each sub-volume is modeled by having hierarchical levels of electromagnetic shielding, determined by interactions through preferred paths. Finally, these interaction paths are integrated into a solution which produces very reasonable results. We demonstrate that the EMT method is also applicable in the microscopic regime.

Characterizing a Transverse Electromagnetic Cell with Nanosecond Pulsed Electric Fields for Biological Applications

The operating characteristics during a transient of a transverse electromagnetic (TEM) test cell coupled to a nanosecond electromagnetic pulse generator are described through experiment and simulations. The coupled system provides a uniform field in a large area for nanosecond pulsed electric fields (nsPEFs) effects studies on biological samples. Results show that the rise time and the fall time of the pulse during a transient are affected because of charging, discharging of the cell. The effects on rise and fall times are aggravated further due to the presence of samples in the cell.