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We investigated changes in aquatic macrophyte communities over 25 years in Utonai-ko (42°42′N, 141°42′E) in northern Japan and determined the major change-producing factors using canonical correspondence analysis (CCA) of 21 measured hydrochemical variables with potential to influence the occurrence of communities. We then examined the corresponding changes in the 25-year fluctuation trends in the communities and measured variables. The most prominent changes were a decline in the Hippuris community and an increase in the Vallisneria and Myriophyllum communities. CCA revealed that the leading variable was significant wave height (SWH), followed by water depth (WD), total nitrogen (T-N), dissolved oxygen (DO), pH, chlorine ion (Cl−), transparency, mud thickness, and suspended solids (SS). The Hippuris community was positively correlated with T-N and Cl− and negatively with SWH, WD, DO, and pH. All of these variables were likewise correlated with the Vallisneria and Myriophyllum communities but in the reverse direction. SS and transparency exhibited no correlations. During the 25 years, WD and T-N increased, but annual maximum wind velocity and Cl− decreased. Fluctuation of DO was

To identify the causes of the rapid expansion of the semi-emergent Phalaris arundinacea L. community in a nutrient-loaded river, we investigated the factors that determine the distribution of the Phalaris and other aquatic macrophyte communities and the shoot growth of P. arundinacea. The Phalaris community was distributed through areas with high organic nitrogen (Org-N), total phosphorus (T-P), PO4-P and suspended solids (SS) concentrations and low dissolved oxygen (DO). P. arundinacea shoots grow better in deep mud and high SS and T-P, all of which were strongly correlated with slower stream currents. Accordingly, although the concentration of total nitrogen constantly increased from 1985 to 1998, the determining nutrient for the expansion of the Phalaris community and P. arundinacea shoot growth stimulation was phosphorus rather than nitrogen. The Phalaris community increased rapidly between 1991 and 1996, when brief but prominent loadings of phosphorus were observed. We concluded that the Phalaris community was restricted due to phosphorus deficiency under nitrogen excess until 1991 and subsequently rapidly expanded over the channel due to the temporary excess phosphorus present during this period. Thereafter, the rapid expansion of the Phalaris community was maintained by the clogging effect of the floating mats formed by shoots and their remains of P. arundinacea, which results in slower currents. A slower current resulted in low DO, the sedimentation of degraded plant remains (high Org-N), and the adsorption of phosphorus by suspended matter (high SS and T-P). The anaerobic conditions caused by low oxygen and the accumulation of decomposable organic matter ensure the continuous development of the Phalaris community through the release of soluble phosphorus from the sediment.

Civil engineers have to obtain the consensus of social opinions in order to produce the structures. As the result, the design of structures is reflected by the age and the social conditions.The level of a functional design, which has a social consensus, is defined as a design standard. The design standard indicates the top levels of technology in every age. A lot of matters are hidden behind the background of the standard. The history of the standard also shows the global tide of technology for an each structure. From a point of view, the history should be put on the trunk of civil engineering history in this sense. However there is no paper that analyze the history of design standards as aproblem of the civil engineering history.In this paper, as the civil engineering history generalize the authors the history of gate-valve design standards, for example, “Flood-Gate and Iron Pipe Standard” and “Dam and Weir Technical Standard”.

The air pollution caused by CO2 from fossil fuel origin was quantitatively studied by radiocarbon (14C) measurement on the samples of new leaves taken from roadside trees. In the area where concentration of CO2 (12CO2+13CO2) of fossil fuel origin was high, the count of β-ray radiation from 14C tended to be low. The relation between the concentration of sulfur dioxide (SO2) in the air and the count of β-ray radiation from the leaf samples could be represented by a linear regression, Y= (17.568/X) -67.385; r = -0.995Where Y is the SO2 concentration in ppb and X is the β-ray radiation count (Bq/g-carbon) .

Two methods were employed to study the fast contrast reversal of magnetic domain images by a photoelastic modulator (PEM). A PEM combined with a quarter-wave plate acts as a polarization rotator, and enables domain observation with fast contrast reversal under exposure to pulsating light. Contrast reversal in as little as 10 ?s is possible. However, the PEM is driven sinusoidally, hence the domain contrast is modulated, resulting in a low average contrast. When a PEM was employed as a phase compensator with a garnet film polarization rotator, it could dynamically compensate for unwanted contributions from the ellipticity of the sample and the garnet rotator. This combination provided not only fast contrast reversal, but even higher contrast compared with that obtained in conventional methods involving the mechanical rotation of an analyzer. In the latter method, a domain image contrast of 0.82 was derived theoretically, and a contrast of 0.76 was obtained experimentally, for domains with ? k =0.19° and ? k =0.13°, whereas the contrast using the conventional mechanical method was 0.72.

The sensitivity of magnetooptical detection of small fields with multidomain materials under a coherent light is discussed. For fields below the saturation, a novel scheme is proposed to increase sensitivity. Separate detection of the undeflected zeroth-order beam and diffracted beams enables their opposing responses to be added. A garnet of theta /sub F/=60 degrees (where /sub F/ is the saturation Faraday rotation) yielded a high sensitivity of more than twice that in the conventional optical configuration while a material of theta /sub F/=90 degrees offers a theoretical improvement of a factor of four. >

Faraday loops traced with an extinction method and magnetization hysteresis loops were compared. When a material consists of a magnetic multidomain, the detected apparent Faraday rotation is not proportional to the net magnetization. In addition to this nonlinearity, light diffraction by domains results in loop deformation. The loop traced with a larger part of diffracted light has more nonlinearity than when it is traced using only the zeroth-order diffracted beam. An extreme case for the nonlinearity of Faraday loop tracing appears when the image of the domains of the material is formed on the photodetector. The nonlinearity increases for a material with a larger Faraday effect while the differential fixed analyzer method gives a loop without nonlinearity. It has been shown that the extinction method for identifying polarization is not helpful for examining the magnetization hysteresis instead of evaluating the magnetization loop itself. >

Few reports of open heart surgery being performed in patients with von Willebrand disease (vWD) have been documented. We describe, herein the case of a 5-year-old girl with a ventricular septal defect (VSD) and vWD who underwent patch closure under cardiopulmonary bypass (CPB). The hematological parameters relating to vWD, namely, factor VIII, von Willebrand factor, and factor VIII-related antigen were monitored perioperatively. These laboratory findings were elevated after the termination of CPB, and consistently maintained within the normal range for 4 months postoperatively. The operation was successfully completed without the administration of factor VIII concentrates or homologous blood products.

Spontaneous hemopneumothorax is a rare disorder, occurring in 1% to 12% of patients with spontaneous pneumothorax. We studied our previously treated patients to determine the nature of optimal operative management.This was a retrospective case study. From 1987 to 1994, of 428 cases of spontaneous pneumothorax that occurred in 234 patients treated at our institution, hemopneumothorax developed in 10 patients (2.3%). The clinical features of these patients were studied.The amount of bleeding ranged from 600 to 1,600 mL, and 3 patients exhibited symptoms of shock, such as sweating, nausea, and syncope. Six patients underwent operation within 7 days from the onset, and this involved resection of the bullae or pneumorrhaphy, or both. The source of bleeding was identified in 5 patients. Pathologic examination showed marked fibrosis with alcian blue-positive deposits of aberrant vessels. All 6 patients continue to be well postoperatively without recurrence or complications. Four patients did not undergo early thoracotomy. However, decortication was required in 3 of these patients because of a reactive fluid collection in the pleural space, which led to impaired lung expansion.Early surgical repair should be considered once diagnosis of a spontaneous hemopneumothorax is confirmed, because this provides better long-term results. Video-assisted thoracoscopic surgery as well as minithoracotomy should be considered as surgical options because of the improved quality of life they confer.

Gd-Co films which have uniaxial magnetic anisotropy perpendicular to the film plane are prepared by the rf-sputtering technique. The transverse Hall effect and the planar Hall effect are studied on these films. Results obtained show that the transverse Hall effect is much larger than the planar one in these films. It is also found that the extraordinary Hall effect plays a dominant role in the transverse Hall effect. At the compensation temperature the polarity of the Hall voltage is reversed. The hysteresis loop of the Hall characteristic corresponds to the M-H loop observed by the Kerr magneto-optic effect.

Magnetic thin films of Fe 1-x Cr x (x = 0.33 to 0.40) with perpendicular magnetization were obtained using the rf sputtering method for the first time. Fe 66 Cr 34 deposited onto an unheated substrate had K u = 6 × 105 erg/cm3, M s = 280 emu/cm3 and H c 1 = 700 Oe. Film composition and substrate temperature during film preparation were the most important factors inducing perpendicular anisotropy. X-ray diffraction studies showed that the induction of perpendicular anisotropy was always accompanied by growth of the crystalline phase (Cr-dominant bcc phase). FeCr films also exhibited high corrosion resistivity in an oxidizing environment. FeCr is a candidate material for use in perpendicular magnetic recording.

This paper describes a simple method for measuring the cubic anisotropy in garnet films. In (111)-oriented garnet films, the magnetization M is rotated from the film normal to the film plane by applying an in-plane field H//. The [111] component Mz of the magnetization M is measured magneto-optically. A plot of MzH// vs. Mz yields an approximately linear relation where the intercept of the line on the MzH// axis changes with the direction of H//, Thus, the cubic anisotropy K1 as well as the uniaxial anisotropy Ku can be estimated from the slope and the intercepts of the extrapolated straight lines for different directions of H//. This method is very simple and may be applied to films whose crystallographic axes in the film plane are unknown. With an adequate choice of the azimuth of the in-plane field, K1 has been estimated with an accuracy of 30%.

Temperature dependence of the electrical resistivity and the galvanomagnetic effect for amorphous rare earth-transition metal ferrimagnetic films between 1.5K and 700K has been studied. Thc absolute value of resistivity is about 270-400 μΩ·cm and the temperature coefficient of resistivity is negative and 10-4/K for Fe alloys and 10-5/K for Co alloys. The temperature characteristic of resistivity is divided into two regions. The logarithmic temperature dependence is dominant from 1.5K to 35K and the square dependence from 50K to 340K. The logarithmic temperature dependence disappears after annealing (1/2 hour at 700K). The square dependence is characterized by the resistivity minimum at about 340K.The transverse magnetoresistance effect decreases with increasing temperature and exhibits the minimum value near the compensation temperature. The electrical resistivity changes about 2.5% and the magnetoresistance effect about 0.01% over the range from 4.2K to 300K. This result shows that the number of domain walls makes very small contribution to the temperature dependence of

Measurement and imaging of medical information invisible directly to human eyes are indispensable to improved diagnoses and to the delivery of quality medical care. This paper discusses development of a multichannel Doppler flowmeter for noninvasive measurement of blood flow in the human heart and the use of a computing system for visual representation of the blood flow profile. Data acquisition from multiple sites of the human body has been greatly simplified by the use of multichannel data acquisition systems developed through research. Also, a new method for discriminating the direction of blood flow, which is far better suited to digital computer processing, is here proposed and methods for displaying the flow using a color/gray level displaying system and a graphic terminal as a data output device are discussed to represent the flow information in a three-dimensional and dynamic manner. Since it has been said in general that Doppler flowmetry is to some extent quantitatively inadequate the accuracy of the developed measuring method is determined by a simulated experiment. Although the data acquired from the measuring system are as yet processed off-line, real-time processing seems to be feasible if an arrow processor is employed.

Stripe domains and bubble domains are observed in Gd-Co sputtered films. The domain patterns are different from one another for different preparation conditions. In this paper, preparation conditions and some properties of Gd-Co films, namely the domain pattern observed by the polar Kerr magneto-optic effect and the M-H loops measured by the Kerr and the Hall effect, are reported. The temperature dependence of the M-H loop is studied about the compensation temperature. The properties of Gd-Co sputtered films are discussed not only for bubble domain but also for thermomagnetic application.

A new type of laser beam deflector using LPE garnet films is presented. The operation is based on the fact that diffraction angle of laser beam is varied by controlling the spacing of parallel stripe domains under the application of a magnetic field. Two methods are proposed to control the domain spacing, namely application of the in-plane field and perpendicular magnetic fields accompanied with anhysteretic high frequency magnetic field. The ratio of maximum to minimum domain spacing is 1.1-1.8, the diffraction efficiency is 0.002-0.08%, and the deflection angle is controlled over a range 3.3-2.2 deg.

Amorphous magnetic thin films with perpendicular magnetization (GdFe, GdCo, TbFe etc.) are successfully prepared by a sputtering or evaporation technique. The magnetic compensation temperature of these films, which is estimated from M-H curves by Kerr or Hall effect and is a meaningful parameter to study the film properties and devices application, is investigated on preparation condition, temperature and thermal treatment after deposition. Several other studies are involved on electrical properties, magnetic wall microscopic observation and its dynamics. Magneto-optic applications utilizing temperature dependence of coercivity are proposed such as thermomagnetic writing in high density thin film memory.

Amorphous magnetic films have unusually large Hall coefficients. We prepared Sm-Co amorphous films with planar or perpendicular magnetization, and studied the galvanomagnetic effect in these films. In this paper, we report on the Sm content dependence of the electrical resistivity ?, the Hall resistivity ?H, the Hall sensitivity S and the Hall voltage V HP-P . We found that ?H is large because of the large saturation magnetization M s and electrical resistivity ?. The maximum value of ?H is 9.0 ??-cm, occuring at 15 at% Sm. We also studied the magnetoresistance of these films.

This paper describes a new type of digital reactor period meter utilizing integrated circuits. The period is calculated from the number of counts N 2 during t 2 at t=τ, where t 2 is equal to t 1 which is the interval required for N 1=104 at t=0. Its output is the digital inverse period signal. The statistical error is delimited by fixing the number of counts instead of the counting interval. The absolute error is about 0.015 sec−1 in the case of a delay time of τ = 1 sec. For τ≧2 sec, it becomes smaller than 0.008 sec−1. The delay time τ is set to a value chosen among 1, 2, 4, 8, 16 and 32 sec, depending upon the count rate. The period meter contains about 250 integrated circuits, of which approximately 80 circuits are used for display and auxiliary functions not directly related to the primary purpose of period calculation.

Successful resection of an ascending aortic aneurysm under cardiopulmonary bypass associated with auxiliary carotid and coronary perfusion is reported. The advantages of the cardiopulmonary bypass such as the present method in surgery of aneurysms of the ascending aorta and aortic arch are discussed.

Recently, magnetic devices utilizing a partial switching have been used in many fields. From a point of core design, a flux distribution must be known. It is possible to calculate them under some assumptions, but it is difficult to measure them experimentally. This paper describes a technique of determining a flux distribution in toroidal and multiaperture ferrite cores. The patterns of flux distribution are expressed by a flux of local zone. The flux level is determined by measuring a second-harmonic voltages induced in a pick up coil under an application of a small ac magnetic field (10 kHz) orthogonal to the plane of core. Small holes for sensing are drilled through the core, and the pick up coil encloses cross-sectional areas between each of the holes. It was found that a flux reversal boundary in a toroidal core travels from inner edge to outer edge when it is switched partially by a dc field, but a pulse field switching produces a complex flux distribution, and that in both cases, the flux reversal boundary is not sharp. By a similar method, the flux distribution in the transfluxor is shown for the "unblocked" and "blocked" state before and after the interrogation. The transfluxor in the unblocked state after the interrogration showed a "kidney shaped" pattern. Readout characteristics obtained from the measured flux distributions agree with those obtained by ordinary induced voltage methods. The accuracy of the readout flux is about 8.7 percent.

A method of optimizing neutron flux distribution to obtain maximum power generation from a given core is presented. Constraining conditions governing maximum heat flux and control rod absorption are taken into consideration. It is shown that the problem is reduced to that of optimal control. In the case of one group model the phase plane technique is effective for an intuitive analysis of the problem. It is verified that the solution so obtained satisfies Pontry-agin's principle. The solution is one of “bang-pang type”. The result is extended to the case of two group model, assuming that the solution will again be of bang-pang type. A comparison is made between the one group and the two group models.

Low geometry a counting and α-particle/γ-ray coincidence counting were made to determine the absolute disintegration rate of an 241 Am source. Alpha particles were counted by silicon junction detectors and γ-rays by an Nal(Tl) crystalphotomultiplier system. The half life of the 60 keV level of 237Np was measured to check the effect of the coincidence resolving time in the absolute measurement of the americium source by α-γ coincidence counting; the half life measured was 6.3 × 10-s sec. The mean value of the absolute disintegration rate of a typical 241Am source measured by coincidence counting was 1.696 ×104 dps and the 90% confidence interval for the mean value was [1.679 ×104dps, 1.713×104dps]. Accurate absolute measurements by low geometry a particle counting are very difficult especially for very small semiconductor detectors because of the difficulty of measuring the accurate geometries.

In this paper, a zero power reactor simulator and thermodynamic-hydrodynamic coolant loops were used to investigate BWR dynamics. The instability which appeared in thermodynamic and hydrodynamic loops in natural circulation condition is the most noticeable phenomenon. To investigate the instability, we operated the boiling loops only as the first step.Combining the zero power reactor simulator and thermodynamic-hydrodynamic loops in a closed form by use of an electric capacitor type of void fraction detecting device, we obtained satisfactory results in BWR simulation. Effects of void coefficient of reactivity on the whole BWR dynamics were investigated, also the influences of the coolant circulation condition were investigated.From these experimental results, it was concluded that the properties of power-void feedback transfer function have the predominant effects on the overall reactor dynamics. So, we investigated further the power-void transfer function and compared it with the theoretical transfer function. We proceeded further the theoretical approaches to understand the interesting tendencies which appeared in experimental power-void transfer function.

A new type of reactor period meter utilizing multi-pulse magnetic counter as a neutron level comparator is described. The counter, which is initially counted for a unit interval at any time, is subtracted by one count for each input pulse after a fixed time-lag. The time required to empty the counter may be converted to reactor period by usage of a logic matrix. Ring ferrite cores are used as high speed shaping element and high speed pental counting element, and Deltamax core (50 Ni-Fe alloy) as decimal counting one. These pental and decimal counting circuits are originated from dividing the total magnetic flux amount (from negative to positive saturation) into 5 and 10 steps, respectively, and changing the flux level in the magnetic core stepwise corresponding to each input pulse. The period meter construction with magnetic cores results in increasing simplicity and reliability, and is much superior to the conventional circuit with a logarithmic amplifier and a differential circuit.

In order to make plans for corrosion control of underground metallic structures it is necessary to survey the sheath current and potential against the ground. A current and voltage recording instrument which was designed for making an electrolysis survey is described and field tests results are reported. The instrument consists of a push-pull self-saturation type magnetic amplifier and a conventional electrical recording voltmeter. It was found to perform as follows:For obtaining 0.6 volt (this corresponds to the full scale 50 mm in the recording meter used), input voltage of the amplifier with Mo-Permalloy cores was 0.48 millivolt for sheath current measurement and 740 millivolts for cable to ground potential measurement in case of the power source of 90 cps with rectangular wave form.Response time was 7 cycles for current measurement and 4.5 cycles for voltage measurement.When the source was supplied from the power line (60 cps), the amplification factors decreased about 10 to 35 percent. The device had good stability, negligible drift and rugged construction. Therefore it is clear that this device is suitable for field test. 4.5.3

For studies of two phase flow, it is very important to measure a void fraction; the fraction of air in water flow. Many methods for the void fraction measurement have been developed hitherto. They are, however, insufficient in respect of their accuracy, response, handling and so forth. This paper reports a void detecting method which is based on a change of the equivalent dielectric constant. By this method, the instantaneous void and the local void can be measured with a fast response.Preliminary experiments are carried out with both the simulated void in the form of glass tubes and the real void in air-water mixture. It is shown that the linearity of this device is good.The basic principle of this void measuring method is discussed, comparing the real void with equivalent circuits which consist of capacitances and resistances.Experimental results of this device applied to a thermodynamic-hydrodynamic loop which simulates the nuclear reactor are shown.

Thermomagnetic writing in amorphous Tb-Fe films prepared by thermal evaporation or rf-sputtering is described. These films have a low Curie temperature (75°C) and large values of coercive force over the wide range of temperature. Spots are thermomagnetically written and erased by using a He-Ne laser in conjunction with external magnetic field, and 1 ∼ 2 micron spots are written stably with low laser power. At this writing, a new property was found, that is, the Kerr contrast of the spots gradually varies with a value of the external magnetic field. Temperature dependences of coercive force and magnetization, spot diameter as a function of writing laser power and the Kerr contrast of spots as a function of external magnetic field are reported.

Ferrimagnetic amorphous Tb-Fe films prepared by rf sputtering or thermal evaporation have a perpendicular anisotropy, a low Curie point (Tc) and large values of coercivity (Hc) over a wide range of temperature. This paper describes the effect of thermal annealing and the contact printing method by Curie point writing for visual display of magnetic information recorded on magnetic tapes or discs. The values of Hc, Tc and the room temperature magnetization (Ms) are reduced by thermal annealing. Thermomagnetic contact printing in an amorphous Tb-Fe film has been tried. It is accomplished by putting the film on the recorded magnetic tape or disc and then heating up the film by photoflash light. The information is observed by means of the polar Kerr effect. In this printing method high resolution printing is realized and analog printing is possible.

Sm x Co 100-x ( 20 \leq x \leq 30 ) films deposited on glass substrate and Sm 37.8 Co 62.2 films deposited on silicon substrate with perpendicular magnetization have been prepared by a magnetron rf sputtering. The influence of sputtering conditions, i.e. bias voltage; substrate temperature; composition and perpendicular magnetic field on perpendicular anisotropy are reported in detail.

Domain wall motion and flux patterns in vacuum-deposited thin film cores were observed under dc and pulsed magnetic fields by using the Kerr magnetooptic effect. Two of the thin film cores have a uniaxial magnetic anisotropy around the circumference, and the other is magnetically isotropic. The domain configuration with current through the center of the hole is circular, and expands radially. Domain wall position was quantitatively measured as a function of dc and pulse current. Circular multi-domain walls like an onion slice appear by switching the polarity of the current, and are moved by the pulse field. By exciting the thin film cores with a drive winding, a notched domain appears without continuity of magnetic flux, but the thin film coated on the permalloy bulk core has a circular domain with continuity of flux. From these results, it is confirmed that the thin film has the domain configuration which depends on the distribution of applied magnetic field, and that the thin film coat transcribes the domain wall motion in the bulk core.

A model for thermomagnetic writing in Gd-Co sputtered films at its compensation temperature is described. In the vicinity of the compensation temperature, the films have rectangular hysteresis loops with large values of coercive force. Spots are thermomagnetically written and erased by using a He-Ne laser in conjunction with an external magnetic field, and a diameter approximately of 1.5 \sim 2 \mu m is achieved. Photographs of spots written thermomagnetically are shown. The written domains are circular and clear in shape, and are stable. Temperature dependences of coercive force in Gd-Co sputtered films, and characters of spot diameter as a function of applied magnetic field and writing laser power are reported.

Magnetic properties of substituted iron garnet films can be changed locally by laser irradiation (annealing and quenching ). We have investigated laser annealing with furnace back-up heating in O 2 , N 2 and Ar gas over a wide range of temperature. In air, laser annealing with high temperature back-up heating above 700°C resulted in domain width reduction with both M s and K u increased differing from other reports. In inert gas, laser annealing with rather low temperature back-up heating is expected to vary magnetic properties locally which is different from that produced by high temperature heating since produced oxygen vacancies lower the activation energy and the relaxation time for cation migration. Only with back-up heating below 650°C, we succeeded high quality annealing in inert gas. Our re-annealing experiment of this film showed that low temperature laser annealing might have lowered the saturation magnetization which is not performed in air. We have found wide temperature range of reversible laser annealing.