The Loop Coverage Comparison Between TCM and Echo Canceller Under Various Noise Considerations

This paper describes loop coverage evaluations of two-wire digital subscriber transmission systems to support the CCITT recommended 1-430 interface. Several range-limiting factors are discussed and a cable utility design for two representative two-wire digital subscriber transmission systems is presented. The two transmission systems are time compression multiplexing (TCM) and echo canceller (EC), utilizing the AMI line code and full cosine rolloff line equalization for both systems. A new impulse noise evaluation is applied to cable utility design, because impulse noise is one of the most stringent range-limiting factors, especially for TCM in utilizing existing subscriber loops. Comparison of TCM with EC is also carried out according to various range-limiting factors. As a result, it is noted that the 320 kbit/s line bit rate TCM is more applicable in NTT's exchange area coverage than the 160 kbit/s EC to achieve the2B + Dbasic interface transmission.     

A method for dispersing dry nano-sized particles in a liquid using carrier particles

A method for dispersing dry particles in a liquid is described. The method involves coating large carrier particles with fine particles. When two types of particles having different sizes are mixed in dry conditions, the particles adhere to one another, and the large particles become coated with small particles. When the large core particles are coated with a mono-layer of small particles, further agglomeration is inhibited. Because the single small particles generated by the disruption adhere to the core particles, we presumed that, if the small particles that are adhered to large particles could be separated from the large particles by a sonication in a liquid, the dry fine particles could be dispersed in a liquid.The dispersion experiments conducted using spherical silica particles having a count median diameter D_p50 of 74 nm as small particles and spherical glass beads as large particles. In this situation, the large particles carry the small particles from a dry condition into a liquid. We refer to the large particles as carrier particles. The experiments revealed that the proposed dispersion procedure results in a superior product, compared to sonication only. The effect of carrier size on dispersion performance is also investigated. The findings indicate and an optimum carrier size exists. Observations of the carrier particle surfaces after dry mixing indicate that the optimum condition is the condition at which a mono-layer of Silica particles is formed.     

Development of a variable quench pressure relief valve for superconducting magnet system

A new variable quench pressure relief valve (VQRV) for a superconducting magnet system has been developed at the High Energy Accelerator Research Organization (KEK). The VQRV is designed that the setting of the blowout pressure can be freely controlled and be maintenance-free for long-term operation.A prototype VQRV was tested under a high radiation environment up to 2.5 MGy. The heat load of 1.5 W at 4.2 K and a seat leakage rate of 4.5 × 10⁻⁷ kg/s at 4.2 K of the VQRV were confirmed. It has enough performances for the cryogenic system operation in the Japan Proton Accelerator Research Complex (J-PARC) neutrino beam line.The design and test results of the VQRV are described in this technical note.     

Modeling of Nonlinear Magnetizing Characteristics of Pole Transformer for Analyzing Islanding Prevention of Photovoltaic System

With increasing penetration of distributed generators such as photovoltaic (PV) systems in distribution systems, it is very important to quickly detect islanding caused by power system faults in order to assure electrical safety. We have developed a nonlinear magnetizing characteristics model of pole transformers for use in analyzing islanding prevention in PV systems. Basic experiments on the islanding detection were performed for verification of the proposed model. Analytical results obtained by the proposed model agreed well with experimental results.     

How do biologists respond to low-intensity armed conflicts? The case of Bangladesh (1961–2011)

Armed conflict affects the biological diversity and biological research regime of a country. This paper takes a low-intensity armed conflict in the biologically and ethnically diverse Chittagong Hill Tracts (CHT) of Bangladesh, as an example, and assesses the response of biologists to this conflict. The study spans the last 50 years dividing it into three periods: pre-conflict (1961?1974), conflict (1975–1997) and post-conflict (1998–2011). Interactions with selected researchers and a literature survey showed that sporadic, intermittent biological research was conducted in this region even during the conflict. The number of research initiatives substantially increased and became more diverse over the last decade. Research opportunity has increased mainly because of improved security and accessibility. Nevertheless, despite the research capacity and a positive attitude among the researchers, some fundamental issues still limit long-term research in this area. The continuing volatile situation due to slow implementation of the 1997 Peace Accord and the tension between rebel factions and indigenous and settler communities in some areas continue to be serious concerns for studying and conserving the biodiversity of this region. Innovative research approaches and the full implementation of the peace agreement are vital to improving the situation for biological research in the CHT. The paper underlines the importance of a biologist’s self-motivation to respond to low-intensity armed conflicts.     

A Study of Hydroxyethyl Starch. Part II. Degradation-Sites of Hydroxyethyl Starch by Pig Pancreas α-Amylase

The degradation sites of hydroxyethyl starch (HES) by pig pancreas α-amylase were determined by gas liquid chromatography. As a result, it was confirmed that HES could be hydrolyzed by α-amylase only at the glucosidic bond of unsubstituted glucose residues, but not at the bond of 2-0-, 3-0-, and 6-0-hydroxyethylglucose residues. Furthermore, it was suggested that the enzymic degradation rate of HES could be well determined by measuring the reducing power.     

A Study of Hydroxyethyl Starch. Long Pursuit of Hydroxyethyl Starch after Consecutive Infusions into Rabbits

The prolonged metabolism of ¹⁴C-HES (¹⁴C-hydroxyethyl starch) was pursued in rabbits, into which it was consecutively infused. 1) ¹⁴C-HES showed such a prolonged persistence that 17.1 and 13.8% of it remained in rabbits, respectively on the 60th and 120th day. 2) A slower apparent elimination rate of ¹⁴C-HES was obtained in tissues or organs, as compared with that in the blood. 3) ¹⁴C-HES was subjected to urinary and fecal excretion even on the 120th day at a rate of about 10mg/day. 4) ¹⁴C-HES showed almost the same metabolism after a single and consecutive infusions.     

Study on the fabrication of a SU-8 cantilever vertically-allocated in a closed fluidic microchannel

Microsystem Technologies - This paper describes the fabrication of a vertically-allocated SU-8 cantilever in a closed fluidic channel. The difficulties to fabricate the vertically-allocated SU-8...     

Changes in myocardial hemodynamics and contractile function in patients under surgical treatment for prostatic adenoma

Hemodynamics and left ventricular myocardial contractility in 170 patients who underwent surgery of prostatic adenoma were examined in preoperative period and 16 days after single-stage transvesical adenomectomy. The age of the patients varied from 52 to 85 years. Echocardiography and the dilution method were used for the evaluation. The increase of end-diastolic and end-systolic volumes, stroke volume, cardiac index, was registered. The combined pharmacological treatment made it possible to decrease the number of operative and postoperative cardiovascular complications.