Optical Fiber Systems and Methods

One embodiment of the invention includes a method for forming an optical fiber. The method comprises providing a preform having a core material and a glass cladding material surrounding the core material. The method also comprises drawing the preform at a temperature that is greater than a melting temperature of the core material to form a drawn fiber. The method further comprises cooling the drawn fiber to form the optical fiber having a crystalline fiber core and a cladding that surrounds the crystalline fiber core and extends axially along a length of the crystalline fiber core

Carrier filtering effect for enhanced thermopower in a body-centered tetragonal ruthenate

Charged carriers in solids diffuse from hot to cold sides under temperature gradient to induce the thermoelectric voltage. Carrier filtering effect, which only passes either electrons or holes for the conduction process, is an efficient method to enhance such voltage, although it is challenging to experimentally realize it especially in conventional metals with weak energy dependence of the density of states near the Fermi level. Here we measure the in-plane and out-of-plane thermopower of the layered perovskite Sr$_2$RuO$_4$ single crystals above room temperature, and find that the out-of-plane thermopower is largely enhanced with increasing temperature, while the in-plane one seems to remain a temperature-independent constant value which is expected from the Heikes formula. The observed large out-of-plane thermopower may originate from the recently proposed intriguing hole filtering effect in the body-centered tetragonal system, in which the carrier hopping through the centered atom is essential. Thus, the present carrier filtering effect may be a universal property to be applicable in various materials belonging to such crystal system.Comment: 6 pages, 4 figure

脊損患者の膀胱機能回復 --急性期無菌間歇導尿管理法の違いによる尿路予後の検討--

1979年6月から1981年12月の間に総合脊損センターで急性期収容治療された外傷性脊髄麻痺90例につき, 急性期無菌間歇導尿管理法の違いによる膀胱の回復状況と治療効果を検討した.急性尿閉期に, 球海綿体筋反射と冷水テストを行なって膀胱回復の関係を調べたところ, 球海綿体筋反射が亢進または存在する例は, 膀胱を急伸展しない限り, 膀胱反射(冷水テスト陽性化)することが判明した.過伸展すると膀胱の回復が遅れる.膀胱反射(冷水テスト陽性化)の出現する時期に一致して, 尿失禁が発現する.過伸展により自己導尿管理がしやすくなる.自己導尿でも感染の危険は少ない.過伸展による水腎症, 膀胱尿管逆流等の合併症は認めなかった.以上の結果より, 将来反射性失禁排尿になる可能性が高い脊損完全麻痺(仙髄領域の知覚が無く, 球海綿体筋反射が亢進または存在する例)に限り, 尿失禁の少ない自己導尿向きの膀胱にする為, 過伸展で行なう急性期無菌歇導尿法も尿路管理法として意義があると考えるNinety patients with spinal cord injury were managed by aseptic intermittent catheterization program I (preventing the over-distension of the bladder) and program II (allowing overdistension) in which recovery of bladder function and the clinical effects were comparatively investigated. Using program I, cases with positive BCR restored the automaticity of the bladder on average 8 weeks after injury. When urinary incontinence first occurs during aseptic intermittent catheterization, urinary training may be commenced since the bladder has then recovered from spinal shock. Cases with no BCR do not restore automatic bladder contraction. Program II delayed or weakened the recovery of bladder function considerably. Patients with incomplete lesions and sacral sparing, particularly those with urinary sensation, should be managed by program I which does not impair recovery of the bladder. It is possible to prevent urinary incontinence and infection, if paraplegics with complete lesions are managed by program II. The percentage of urinary infection was 22.6 +/- 16.0% (N = 90) during aseptic intermittent catheterization (non-touch technic) among whom no statistically significant difference between those with trigger voiding (22.2 +/- 17.2%, N = 57) and those with self-catheterization (23.2 +/- 14.0%, N = 33) was found

Doppler Global Velocimetry: A New Way to Look at Velocity

A new laser velocimetry technique, Doppler global velocimetry, is described. This technique is capable of simultaneously measuring in real time the three components of velocity of an entire particle field illuminated by a laser light sheet. A prototype one-component velocimeter is described along with the signal processing electronics. The system was tested by measuring the velocity field from a rotating wheel and a small subsonic jet flow in the laboratory. The first wind tunnel test measured the vortical velocity field above a delta wing. The results are presented and compared with fringe-type laser velocimeter and five-hole probe data