Compact effector optics for processing in limited physical access situations

A major advantage of fiber-optic beam delivery in laser materials processing is the ability to guide the laser power to the location where it is needed, leaving the laser itself remote and protected from the process. This is of special importance if the processing is to be performed in a hazardous environment. Particular problems are faced by the nuclear industry where weld repair and surface treatment work are required inside radioactive installations. By use of fiber beam delivery, only part of the delivery system and effector optics become contaminated, but the expensive laser system does not. However, in many cases the region where repair is required is not only radioactive but has only limited physical access, e.g., inside tubes or into corners, which prevents use of standard effector optics. We present a new design to deal with such constraints of a 2-mm outer diameter employing a hollow waveguide and gas shielding. This design is optically characterized and its performance assessed in welding and surface treatment applications. The potential of this compact effector optics in limited physical access situations is clearly demonstrated.     

Beam homogenizer for hollow-fiber delivery system of excimer laser light

A beam homogenizer for a hollow-fiber-based, UV laser delivery system is proposed. A rectangular glass waveguide with an inner aluminum coating that has a 1-mm square cross section is attached at the output end of the circular-core hollow fiber with a 1-mm inner diameter. The rectangular waveguide generates a number of higher-order modes and results in a uniform top-hat profile. The configuration of the waveguide is designed by a ray-tracing technique so that both the low transmission loss and the high uniformity in the output beam are obtained. The fabricated waveguide shows a low loss of 0.4 dB, and the intensity variation coefficient is 7%. The output beam from the rectangular waveguide is expanded by a lens to the size larger than 10-mm square. It is also shown that the profile does not change with the bending condition.     

Successful treatment of bilateral deep femoral aneurysms and multiple iliac aneurysms associated with severe aortic valve disease: report of a case

We report herein the case of a patient in whom aneurysms of the bilateral deep femoral arteries (DFA) and multiple iliac aneurysms associated with severe aortic valve disease were successfully treated by a two-staged operation. The patient was a 74-year-old man who had dense calcification of the ascending aorta and aortic arch. Prior to aortic valve replacement (AVR), the aneurysms of the DFA and internal iliac arteries were resected. The terminal end of the abdominal aorta and bilateral common iliac arteries were then reconstructed with a Y graft to be used as a possible alternative arterial input route in place of the ascending aorta for extracorporeal circulation during the AVR. The inferior mesenteric artery (IMA) was well developed, and the external iliac arteries and their branches were preserved at aneurysmectomy. Postoperatively, there was no ischemia of the pelvic organs or the hip muscles. The AVR was subsequently performed 5 weeks after the first operation, and the patient was discharged after an uneventful postoperative course.     

The activities of uroporphyrinogen synthetase and cosynthetase in congenital erythropoietic porphyria (CEP)

Normal or increased amounts of series III porphyrins with greater amounts of series I were observed on incubation of PBG in hemolysates of congenital erythropoietic porphyria vs. normal erythrocytes, human or bovine. Correlation with reticulocyte percentage was poor, in the aggregate a general trend toward increased values of both isomers I and III was noted with increasing reticulocytes. When the percent of type III was low the net amount was increased as compared with normal. Hemolysates of non-porphyric, reticulocyte-rich red cells (hemolytic or posthemorrhagic anemia) formed only minute amounts of type I porphyrin but at the same time no more, or even less type III than the porphyric hemolysates, although representing red cells of greater reticulocyte content. No evidence of deficient heme synthesis was observed in porphyric hemolysates incubayed with [14C]-porphobilinogen or 59Fe. Other studies of porphyric hemolysates incubated with and without added mouse spleen synthetase failed to reveal evidence of an absolute UPG-III cosynthetase (Co-S) deficiency. The large increases of type I porphyrin with normal or increased formation of type III, both in the disease and in the hemolysates, are believed due to a primary increase of ALA-S or UPG-S activity rather than a decrease of Co-S. Possible mutations which might be responsible for this increase are considered.     

Membrane process for emulsified waste containing mineral oils and nonionic surfactants (alkylphenolethoxylate)

Using membrane processes we studied the improvement of the treatment of waste emulsified by mineral oils and alkylphenolethoxylate (APE) and investigated diatomaceous earth processing for comparison. A quantitative analysis of the mineral oils and APE using column chromatography was applied to assess these processes. Despite substantial rejection of the turbidity values of emulsified model waste, the percentages of mineral oil and APE rejections using microfiltration (MF) processes were 39-61% and 16-19%, respectively. In contrast, the ultrafiltration (UF) process could reject 97% for the mineral oils and 90% for APE. The diatomaceous earth adsorption processes reduced the mineral oils 40-49% and the APE, 8-14%, and therefore were inferior to the UF process for waste treatment. The average fluxes of both the MF and UF membranes until the volume reduction factor (VRF) reached a value of 5 were almost the same in the range of 8 x 10(-6)-14 x 10(-6) m3 m-2 s-1. For commercial application, decrease in the permeate flux by fouling needs to be resolved.     

Development of novel rare earth doped fluoride and oxide scintillators for two-dimensional imaging

Two topics were focused.The first one was about the gamma-ray scintillator,Pr3+:Lu3Al5O12(LuAG) .The second one was about neutron scintillator,Ce3+:6LiCaAlF6 and Eu2+:6LiCaAlF6(6LiCAF) .Those scintillators have been developed very recently for modern imaging appli-cations in the medical and homeland security fields.In both cases,the rare earth ions are playing the crucial role as emission centers.Pr3+ in LuAG provided fast 5d→4f transition providing noticeably shorter decay time than that of Ce3+.Among several candidate hosts,LuAG showed the best performance.Bulk crystal growth,basic scintillation properties,two-dimensional gamma-ray imaging and positron emission mammography(PEM) application were demonstrated.Due to the international situation,the homeland security was compromized by illicit traffic of explosives,drugs,nuclear materials,etc.and the ways to its improvement became an important R&D topic.For this purpose the Ce and Eu doped LiCAF ap-peared competitive candidates.Especially,when substitution of 3He neutron detectors was considered,the discrimination ability of gamma-ray from alpha-ray was important.Bulk crystal growth,basic scintillation properties and two-dimensional neutron imaging were demonstrated.     

试验室利用工业废渣制硅酸钙板的影响因素

在试验室利用工业废渣制绿色环保硅酸钙板的过程中,主要影响因素有:原料的种类和来源、理化性质、配合比添料种类与含量原料的混合工艺,预养时间及方法,蒸养制度和去压方法。不断进行制硅酸钙板的科学试验研究,提升硅酸钙板的综合性能,有利于完善试验室制硅酸钙板的工艺制度,指导硅酸钙板的工业生产,进而推进工业废渣制硅酸钙板绿色环保产业的可持续发展。     

Searching for noble Ni–Nb–Zr thin film amorphous alloys for optical glass device molding die materials

This paper presents a search for Ni–Nb–Zr thin film amorphous alloys for use as optical glass device molding die materials. To efficiently search for candidate materials, we used a combinatorial method to evaluate thermal stability. First, compositionally spread Ni–Nb–Zr libraries were fabricated by combinatorial arc plasma deposition (CAPD). To evaluate thermal stability, the Ni–Nb–Zr amorphous CAPD samples in the libraries were annealed in vacuum at 723 K, representing the molding temperature for glass devices, for various time periods. The phases of the annealed CAPD samples were identified using X-ray diffractometry (XRD). From XRD identification, candidate amorphous compositions with high thermal stabilities were screened. Sputter-deposited samples with the same candidate amorphous compositions were subsequently fabricated. Other desired properties for optical glass device molding die materials, including mechanical strength, linear expansion coefficient, oxidation resistance, machinability and anti-sticking properties to molten glass, were evaluated. The investigation revealed Ni₃₆Nb₃₉Zr₂₅ to be a suitable composition for a new glass lens molding die material. This material exhibited a high fracture stress, σ_f, of 1.3 GPa, good heat resistance, good oxidation resistance, similar linear expansion coefficient as glass, good machinability, and excellent anti-sticking properties to molten glass.     

Biofunctional calcium titanate coating on titanium by simple chemical treatment process using calcium-hydroxide slurry—Effects of the heating temperatures

The present study investigates the effect of the heating temperature on the characteristics of the surface layer in a simple treatment process using calcium-hydroxide slurry. Furthermore, biofunctions of the treated titanium surfaces, such as bioactivity in a simulated body fluid and corrosion resistance under a bio-environment, are also investigated. Our treatment process using calcium-hydroxide slurry is as follows: a titanium substrate is buried in calcium hydroxide slurry, and the slurry is then heated in air. The calcium hydroxide slurry was prepared by mixing of calcium hydroxide powder and water. When treated at heating temperature beyond 873 K, a crystallized calcium titanate coating is formed on a titanium substrate and further, the thickness increases with the increase of heating temperature. On the crystallized calcium titanate coating, calcium phosphate is precipitated in a simulated body fluid; therefore, the treated titanium surface has bioactivity. Furthermore, anodic current density of the treated surface is 10–10³ times lower than that of the non-treated surface.