Effects of beam focusing on the efficiency of planar waveguide grating couplers

Results of a theoretical and experimental study into the variation of coupling efficiency with a grating angle are presented for various beam focusing conditions for an integrated optical grating coupler. The study shows that the acceptance angle of the grating coupler can be broadened within a relatively large range and with a relatively small loss of coupling efficiency, by focusing the incident laser beam

Studies on the stabilities of some metal selenite sulphide, and selenide complexes in solution

Montréal Trigonix inc. 201

Hydatid Cyst of Thoracic Spine: A Rare Cause of Paraplegia

Primary spinal hydatid cysts are uncommon and extradural involvement is rare. We report an unusual case of Paraplegia due to hydatid disease of primary site of infection extra spinal muscles in thoracic region from T5 to T8 level extending into a daughter cyst at T9 level, is main cause of acute Paraplegia. Magnetic resonance imaging (MRI) showed an extradural round cystic lesion in the spinal canal filling the posterior and left postero-lateral expect at T9 level, markedly compressing the cord. The cyst was removed after laminectomy and opening of the dural sac, with excision of extraspinal mass in left paravertebral region from T5 to T8 level. Histopathological examination confirmed a diagnosis of hydatid cyst. Early decompression surgery of the spine with chemotherapy is the treatment of choice for the disease

Purification, Biotinylation, and Testing of a Monoclonal Antibody to Identify B Cells in Trachemys Scripta, the Red-Eared Slider Turtle

There is a shortage of research in reptile immunity which is further hampered by lack of reptile-specific reagents. Evidence suggests there are important differences between reptile and mammalian immune strategies and our laboratory is interested in reptile B cell development and function. Our undergraduate research project involved the preparation of a previously developed monoclonal antibody (HL673) that recognizes turtle light chain protein. To begin, culture supernatant from the HL673 mAb murine cell line was received and was applied to a protein A affinity column. Unbound proteins were then washed away, and the bound proteins were removed from the column using low pH glycine-HCl buffer. The purified antibody proteins were collected in fractions, OD at 280nm measured, then positive fractions were pooled and dialyzed. The concentration of the purified antibodies was determined, and reactivity tested using an ELISA plate coated with dilute turtle serum. Dilutions of the purified HL673 were detected by anti-mouse IgG-horseradish peroxidase (HRP). Furthermore, some of the antibody preparation was conjugated to biotin. After dialysis, the HL673-biotin was tested by ELISA with dilute turtle serum and detected by streptavidin-HRP. The newly biotinylated antibody was incubated with blood and spleen samples from both adult and hatchling red- eared slider turtles. Bound antibodies were detected using streptavidin-fluorochrome and B cell populations identified using flow cytometry. Our results showed successful detection of turtle B cells using the labeled mAb in both hatchling and adult turtle cell samples. Future studies will use this reagent to investigate the distribution and function of B cells in reptile gut immunity. This work was supported by NSF 1725199 and NIH 1R15AI140118 – 01.https://ir.library.illinoisstate.edu/urs2021bio/1007/thumbnail.jp

Monitoring and assessment of changes in Glaciers, Snow, and Glacio-hydrology in the Hindu Kush – Himalaya

Mr. Pradeep Mool, Centre for Integrated Mountain Development, Nepal, at the NRF 6th open Assembly in Hveragerði, Iceland. September 2011

Systems and Methods of Laser Texturing of Material Surfaces and Their Applications

The surface of a material is textured and by exposing the surface to pulses from an ultrafast laser. The laser treatment causes pillars to form on the treated surface. These pillars provide for greater light absorption. Texturing and crystallization can be carried out as a single step process. The crystallization of the material provides for higher electric conductivity and changes in optical and electronic properties of the material. The method may be performed in vacuum or a gaseous environment. The gaseous environment may aid in texturing and/or modifying physical and chemical properties of the surfaces. This method may be used on various material surfaces, such as semiconductors, metals and their alloys, ceramics, polymers, glasses, composites, as well as crystalline, nanocrystalline, polycrystalline, microcrystalline, and amorphous phases

Microwave Nondestructive Evaluation of Dielectric Materials with a Metamaterial Lens

A novel microwave Nondestructive Evaluation (NDE) sensor was developed in an attempt to increase the sensitivity of the microwave NDE method for detection of defects small relative to a wavelength. The sensor was designed on the basis of a negative index material (NIM) lens. Characterization of the lens was performed to determine its resonant frequency, index of refraction, focus spot size, and optimal focusing length (for proper sample location). A sub-wavelength spot size (3 dB) of 0.48 lambda was obtained. The proof of concept for the sensor was achieved when a fiberglass sample with a 3 mm diameter through hole (perpendicular to the propagation direction of the wave) was tested. The hole was successfully detected with an 8.2 cm wavelength electromagnetic wave. This method is able to detect a defect that is 0.037 lambda. This method has certain advantages over other far field and near field microwave NDE methods currently in use

Plume and Nanoparticle Formation During Laser Ablation

The processes that lead to material ejection when a solid sample is irradiated near and above the pulsed laser ablation threshold are discussed. Emphasis is placed on the thermal and mechanical mechanisms that occur during pulsed laser irradiation of metals and semiconductors. Distinctions are drawn between ultrafast-pulsed irradiation, which occurs under stress confinement, and shortpulsed irradiation, in which stress is released during the laser pulse. Similarly, the distinctions between the spallation and phase explosion regimes are discussed. Spallation is only possible when the time of the laser heating is shorter than the time needed for mechanical equilibration of the heated volume, while phase explosion can occur for pulses shorter than tens of ns. Nanoparticle formation can occur directly in the plume as the result of the decomposition of ejected liquid layers or a porous foam created by the phase explosion, as well as through condensation of vaporized atoms (enhanced by the presence of an ambient gas)