Inscribing diffraction grating inside silicon substrate using a subnanosecond laser in one photon absorption wavelength

Using focused subnanosecond laser pulses at 1.064μm wavelength, modification of silicon into opaque state was induced. While silicon exhibits one-photon absorption at this wavelength, the modification was induced inside 300μm-thick silicon substrate without damaging top or bottom surfaces. The depth range of the focus position was investigated where inside of the substrate can be modified without damaging the surfaces. Using this technique, diffraction gratings were inscribed inside silicon substrate. Diffraction from the gratings were observed, and the diffraction angle well agreed with the theoretical value. These results demonstrate that this technique could be used for fabricating infrared optical elements in silicon

Microfabrication of Three-Dimensional Structures in Polymer and Glass by Femtosecond Pulses

We report three-dimensional laser microfabrication, which enables microstructuring of materials on the scale of 0.2-1 micrometers. The two different types of microfabrication demonstrated and discussed in this work are based on holographic recording, and light-induced damage in transparent dielectric materials. Both techniques use nonlinear optical excitation of materials by ultrashort laser pulses (duration < 1 ps).Comment: This is a proceedings paper of bi-lateral Conf. (Republics of China & Lithuania) on Optoelectronics and Magnetic Materials, Taipei, May 25-26, 2002.

Mutual determination of Iron and Tropolone

It has been known that tropolone reacts with iron to give green and brownish red complexes. It was found that the green complex is formed in the presence of excess iron, while the latter, in the presence of excess tropolone. The green complex shows a broad absorption band with its maxima at 435 and 582 mμ. The maximal color develops over the acidity range from 0.05 to 1 N. The formation of the brownish red one is complete over the pH range from about 1.3 to 8.5 and it shows the absorption peaks at 425, 550 and 595 mμ. The composition of the green complex is 1 : 1. That of red one is considered to be 1 : 3. The formation constant of the green complex is evaluated to be 1.0×10^. These complexes are utilized in the mutual determination of iron and tropolone. Beer\u27s law is valid for both complexes at the wavelength of maximum absorbancy and iron and tropolone have been determined up to 0.07 γ/ml and 1.0×10^ M/1 respectively

Spectrophotometric Studies on Organometallic Complexes Used in Analytical Chemistry On the Germanium Complex with 3-hydroxytropolone

An investigation was made by the authors to find soluble colored complexes of germanium. As a series of the study, examinations were made of several tropolones. And it was found that germanium formed water soluble complexes with them suitable for the determination of germanium. The features of the absorption spectra of tropolones and its complexes with germanium are discussed. The composition and formation constant of 3-hydroxytropolone-germanium complex in aqueous solution were also evaluated. The composition of the complex was found to be 1 : 3

Determination of Microgram Quantities of Germanium with Quercetin

Various organic compounds form colored complexes with germanium. But nearly all of them are highly insoluble. Complex with phenylfluorone or hematoxylin, for example, which has been in practical use for the determination of germanium is difficultly soluble in water. The precipitate is, therefore, dispersed with gum arabic or gelatin. But growth or aggregation of the precipitates was observed on left standing and consequently transmittancy readings were changed with lapse of time. And thus reproducible results could hardly be obtained especially when concentration of germanium was high. Germanium complex with quercetin, on the other hand, is soluble. Accordingly satisfactory results were obtained. It obeied Beer\u27s law up to 0.54 γ/ml of germanium. Sensitivity is also enough

コウヒンシツ コロイド ケッショウ セイチョウ ギジュツ ノ カクリツ

To grow large and high-quality colloidal crystals, several techniques have been investigated. Apparatus for soap-free emulsion polymerization was built up. Synthesis of surfactant-free polystyrene microparticles colloidal dispersions with small diameter dispersion was achieved. Reduction of particle size polydispersity by crystallization, preceded by a thermodynamic consideration, was attempted and worked in few conditions. In-situ observation was found to be a fruitful method to obtain the information of crystallization process

ヒカリヘンカン ポリタイプ オ モチイタ ワイド バンド ギャップ

Femtosecond laser-induced structural transformations in wide band-gap semiconductors were studied for the development of the fabrication technique for three-dimensional electronic circuits. In particular, we will report the results on the femtosecond laser-induced periodic structures produced on wide band-gap materials. We also investigated the material properties of laser-irradiated spot by using confocal micro Raman spectroscopy and transmission electron microscopy. We will discuss the effect of femtosecond laser-irradiation on wide band-gap semiconductors

Intestinal Perforation by Ingested Foreign Bodies

Seven cases with intestinal perforation by ingested foreign bodies (IFBs) were surgically treated in our hospital between January 2000 and August 2009. We reviewed the preoperative mental conditions, awareness of ingestion, preoperative diagnosis, the type of foreign bodies, perforation site, treatment and morbidity for these patients. The ratio of males to females was 4 : 3, and patient age ranged from 27 years to 85 years. Three of 7 patients had an abnormal mental condition, including neurosis with medication in 1, severe mental retardation in 1 and dementia in 1. Six patients were not aware they had IFBs. Preoperative diagnoses were perforative peritonitis in 6 cases and ileus in 1 case. The ingested objects consisted of fish bones in 4 cases, toothpicks in 2 cases and a press-through package in 1 case. Computed tomography (CT) showed the ingested fish bones in all 4 cases, while plain abdominal radiography demonstrated fish bone in only one of these cases. Toothpicks and a press-through package were not detected on CT or by plain abdominal radiography. The perforation sites were the small intestine in 5 cases and the large intestine (transverse colon) in 2 cases. Treatments were intestinal resection with or without omentectomy in 5 cases, suture alone in 1 case and omentectomy alone in 1 case. Postoperative complications were seen in 2 patients, including hepatic failure and bleeding from gastroesophageal reflux disease in 1 case, and removal and reinsertion of a V-P shunt tube in 1 case. The mortality rate was 0%

Adult T-Cell Leukemia/Lymphoma with Gastric Lesion

A case of adult T-cell leukemia/lymphoma with a gastric tumor is presented. The patient was a 72-year-old woman who had been admitted to our hospital because of epigastric pain. Upper gastrointestinal endoscopy disclosed polypoid region in the antrum of the stomach. Specimens taken from this region revealed malignant lymphoma. Although the patient was serologically positive for human T-cell leukemia virus type I antibody. A chest X-ray, abdominal ultrasonography, and whole body computed tomography revealed no lymphadenopathy. We diagnosed her to have primary gastric malignant lymphoma and thus performed a total gastrectomy with regional lymph node excision and a splenectomy. Both histological and immunohistochemical studies of the resected specimen showed the lymphoma to be a diffuse pleomorphic type with a T cell phenotype. A radical surgical resection could be performed. At nine months postoperatively, she was again admitted to our hospital because of abdominal pain. Both ultrasonography and computed tomography revealed lymph node swelling around the surrounding the para aorta. She was treated with systematic chemotherapy. Unfortunately, she died at one year after the operation