Use Of Isolation Research Articles

Thick Film Crystal Growth of the Highly Bi-Substituted Garnet for Optical Isolator

We studied the melt composition to obtain pit-free, highly Bi-substituted (BiLu) 3 Fe 5 O 12 crystals by the LPE method. It was confirmed that adding B 2 O 3 to the melt increases the equilibrium segregation coefficient of Bi K 0(Bi) , and we found that a decrease in garnet composition ratio R 4 acts to increase the growth rate dependence of the normalized effective segregation coefficient of Bi K eff(Bi) / K 0(Bi) . It was also found that crystals with mirror-smooth surfaces could be obtained by adding Gd 2 O 3 to the melt. Using a melt with Gd 2 O 3 /Lu 2 O 3 ? 1, the pits which usually appear in LPE growth of (BiLu) 3 Fe 5 O 12 were eliminated, and pit-free, highly Bi-substituted (BiLuGd) 3 Fe 5 O 12 crystals were obtained. The optical properties of 250 ?m thick (BiLuGd) 3 Fe 5 O 12 crystals were measured in order to evaluate their applicability to optical isolators for use at 1.3 ?m. A sufficient Faraday rotation of ? F = ?1800 deg/cm and an extinction ratio of ?40 dB were obtained.

Nosocomial infection: Prevention by special cleanair, ultraviolet light, and barrier (isolator) techniques

Nosocomial infection: Prevention by special cleanair, ultraviolet light, and barrier (isolator) techniques

Single-mode optical isolator at 1.3 μm using all-fibre components

An optical isolator for use at 1.32 μm has been fabricated using standard communication-grade single-mode fibre as an optical rotator fitted with high-birefringence fibre pigtails containing an in-line tapered fibre polariser. A novel adjustment procedure ensures isolation levels are limited only by the polariser extinction ratio. Isolation levels in excess of 21 dB have been recorded with an insertion loss of less than 3 dB.

Use of the flexible film isolator as a single circuit hypoxic chamber for small animals.

PVC isolators are now widely used for housing animals and provide a readily available pretested air-tight chamber (Pendry, 1984; Trexler, 1984). We have adapted a flexible film isolator for use as a hypoxic chamber for small animals. The environment within the chamber can be easily and continuously monitored with indwelling probes, obviating the need for a separate circuit for gas analysis. This design has been used for long-term studies of chronic hypoxia.

A compact optical isolator

This report describes the design and performance of a compact optical isolator for use in the visible region of the spectrum. The device is simple and cheap to manufacture, providing a figure of merit of 37.6 dB with a typical 1 dB insertion loss.

Soy protein in feeding the elderly

AbstractProtein needs of the elderly may be moderately higher than those of younger adults when expressed as a percentage of total calories. Most experts recommend an intake of ca. 0.8 g protein/kg/day or ca. 12–15% of the total calories. Soya protein appears to be as good as animal protein in meeting the amino acid and protein needs of adult humans when consumed in adequate quantities. Attention must be given to the appropriate heat treatment and processing of soybeans to inactivate non‐nutritional factors. The mineral and vitamin content of the diet should be monitored, because some of these nutrients may be altered or removed in the preparation of soya protein fractions or isolates for use in food products. Further research is needed to fully identify the nutritional requirements of the elderly, especially as affected by disease, trauma and drugs. In addition, nutrient interaction and bioavailability should be studied in foods which are processed by new techniques.

Development and Use of a Microagglutination Test to Detect Antibodies to Alcaligenes faecalis in Turkeys

A neotetrazolium-chloride-stained Alcaligenes faecalis antigen was developed for use in the microagglutination (MA) test. The test was used to detect serum antibodies in naturally and experimentally infected turkeys. The highest titer observed in naturally infected birds was 1:320. In one commercial flock, antibodies were detected at 12 and 15 weeks after the initial disease outbreak. Four experiments were conducted to study the serologic responses of turkeys to A. faecalis. Antibodies were first detected at 2 weeks postexposure (PE) in poults that were exposed to the organism at 1 week of age. Peak antibody titers were detected at 3 weeks PE; isolations of the organism then declined. No antibodies were detected at 7 weeks PE in these birds. Birds infected at 5 weeks of age via various routes developed maximum antibody titers 2 weeks PE. Birds inoculated subcutaneously had the highest titers, whereas those inoculated intramuscularly had the lowest titers. Antibodies were still detected at 56 days PE in some birds. Hens vaccinated with an inactivated A. faecalis bacterin developed antibody titers. Titers not higher than 1:40 were detected at hatching in progeny of these hens. However, these poults were not protected from disease after challenge. There was some evidence that birds exposed to live or inactivated A. faecalis develop some protection against challenge. Antigens were prepared using 4 Ohio A. faecalis isolates (A, B, C, and D) and 1 North Carolina isolate for use in the MA test. The results indicated that the 5 isolates were antigenically similar. Antigens prepared using isolate B reacted best in the MA test.

A reliable Faraday rotator with solid state switching

A Faraday rotator isolator for use in laser systems is described. The rotator has a long extinction period, is easy to construct and operate and has solid state switching.

High-power isolator for the 10-μm region employing interband Faraday rotation in germanium

Interband Faraday rotation in intrinsic germanium has been employed to construct a room-temperature optical isolator for use in the intermediate infrared region. The device was tested at 9.55- and 10.59-μm wavelengths, and exhibited an isolation level of 41 dB at 106 W cm−2. The rotation is shown to be relatively insensitive to temperature at the two wavelengths and linear in magnetic field intensity up to 83 kG. The isolator figure of merit is about 60 deg per dB attenuation.

S-band ferrite isolator for use with a linear accelerator

S-band ferrite isolator for use with a linear accelerator