Performance and Flow Field of a Gravitation Vortex Type Water Turbine

A gravitation vortex type water turbine, which mainly comprises a runner and a tank, generates electricity by introducing a flow of water into the tank and using the gravitation vortex generated when the water drains from the bottom of the tank. This water turbine is capable of generating electricity using a low head and a low flow rate with relatively simple structure. However, because its flow field has a free surface, this water turbine is extremely complicated, and thus its relevance to performance for the generation of electricity has not been clarified. This study aims to clarify the performance and flow field of a gravitation vortex type water turbine. We conducted experiments and numerical analysis, taking the free surface into consideration. As a result, the experimental and computational values of the torque, turbine output, turbine efficiency, and effective head agreed with one another. The performance of this water turbine can be predicted by this analysis. It has been shown that when the rotational speed increases at the runner inlet, the forward flow area expands. However, when the air area decreases, the backward flow area also expands

RAISE-2 for Agile On-Orbit Demonstration of Innovative Satellite Technologies: Program Strategy, Mission Definition, and Preliminary Design

The Japan Aerospace Exploration Agency (JAXA) has provided the second demonstration opportunity of the Innovative Satellite Technology Demonstration Program. In this second mission, JAXA develops the Rapid Innovative Payload Demonstration Satellite-2 (RAISE-2) that carries six components and parts as on-orbit demonstration themes. This paper presents an overview of the RAISE-2’s demonstration themes, mission definition including standard platform specifications, results of Phase-A study and preliminary design

The Design Method of Axial Flow Runners Focusing on Axial Flow Velocity Uniformization and Its Application to an Ultra-Small Axial Flow Hydraulic Turbine

We proposed a portable and ultra-small axial flow hydraulic turbine that can generate electric power comparatively easily using the low head of open channels such as existing pipe conduits or small rivers. In addition, we proposed a simple design method for axial flow runners in combination with the conventional one-dimensional design method and the design method of axial flow velocity uniformization, with the support of three-dimensional flow analysis. Applying our design method to the runner of an ultra-small axial flow hydraulic turbine, the performance and internal flow of the designed runner were investigated using CFD analysis and experiment (performance test and PIV measurement). As a result, the runners designed with our design method were significantly improved in turbine efficiency compared to the original runner. Specifically, in the experiment, a new design of the runner achieved a turbine efficiency of 0.768. This reason was that the axial component of absolute velocity of the new design of the runner was relatively uniform at the runner outlet in comparison with that of the original runner, and as a result, the negative rotational flow was improved. Thus, the validity of our design method has been verified

Study on an Axial Flow Hydraulic Turbine with Collection Device

We propose a new type of portable hydraulic turbine that uses the kinetic energy of flow in open channels. The turbine comprises a runner with an appended collection device that includes a diffuser section in an attempt to improve the output by catching and accelerating the flow. With such turbines, the performance of the collection device, and a composite body comprising the runner and collection device were studied using numerical analysis. Among four stand-alone collection devices, the inlet velocity ratio was most improved by the collection device featuring an inlet nozzle and brim. The inlet velocity ratio of the composite body was significantly lower than that of the stand-alone collection device, owing to the resistance of the runner itself, the decreased diffuser pressure recovery coefficient, and the increased backpressure coefficient. However, at the maximum output tip speed ratio, the inlet velocity ratio and the loading coefficient were approximately 31% and 22% higher, respectively, for the composite body than for the isolated runner. In particular, the input power coefficient significantly increased (by approximately 2.76 times) owing to the increase in the inlet velocity ratio. Verification tests were also conducted in a real canal to establish the actual effectiveness of the turbine

Study on an Undershot Cross-Flow Water Turbine with Straight Blades

Small-scale hydroelectric power generation has recently attracted considerable attention. The authors previously proposed an undershot cross-flow water turbine with a very low head suitable for application to open channels. The water turbine was of a cross-flow type and could be used in open channels with the undershot method, remarkably simplifying its design by eliminating guide vanes and the casing. The water turbine was fitted with curved blades (such as the runners of a typical cross-flow water turbine) installed in tube channels. However, there was ambiguity as to how the blades’ shape influenced the turbine’s performance and flow field. To resolve this issue, the present study applies straight blades to an undershot cross-flow water turbine and examines the performance and flow field via experiments and numerical analyses. Results reveal that the output power and the turbine efficiency of the Straight Blades runner were greater than those of the Curved Blades runner regardless of the rotational speed. Compared with the Curved Blades runner, the output power and the turbine efficiency of the Straight Blades runner were improved by about 31.7% and about 67.1%, respectively

PSMC5, a 19S Proteasomal ATPase, Regulates Cocaine Action in the Nucleus Accumbens

ΔFosB is a stable transcription factor which accumulates in the nucleus accumbens (NAc), a key part of the brain’s reward circuitry, in response to chronic exposure to cocaine or other drugs of abuse. While ΔFosB is known to heterodimerize with a Jun family member to form an active transcription factor complex, there has not to date been an open-ended exploration of other possible binding partners for ΔFosB in the brain. Here, by use of yeast two-hybrid assays, we identify PSMC5—also known as SUG1, an ATPase-containing subunit of the 19S proteasomal complex—as a novel interacting protein with ΔFosB. We verify such interactions between endogenous ΔFosB and PSMC5 in the NAc and demonstrate that both proteins also form complexes with other chromatin regulatory proteins associated with gene activation. We go on to show that chronic cocaine increases nuclear, but not cytoplasmic, levels of PSMC5 in the NAc and that overexpression of PSMC5 in this brain region promotes the locomotor responses to cocaine. Together, these findings describe a novel mechanism that contributes to the actions of ΔFosB and, for the first time, implicates PSMC5 in cocaine-induced molecular and behavioral plasticity.National Institutes of Health (U.S.)National Institute on Drug AbuseIshibashi FoundationJapan Society for the Promotion of Science (KAKENHI 24591735)Japan Society for the Promotion of Science (KAKENHI 26290064)Japan Society for the Promotion of Science (KAKENHI 25116010

¿De vuelta a Los ocho años? A propósito de La guerra de Figueres, de Guillermo Villegas Hoffmaister

El libro de Guillermo Villegas Hoffmeister, “La guerra de Figueres”, tiene sin duda el subtítulo exacto Crónica de ocho años, porque eso es lo que es. Basado en alguna documentación escrita, en sus propios recuerdos personales y en una revisión de los periodos de la década de 1940, la obra se presenta ante todo como un producto de entrevistas realizadas por el autor a distintos personajes de la época. El resultado final es una narrativa descriptiva y parcializada, que combina alguna información interesante con datos sin importancia y algunas notables inexactitudes históricas: por ejemplo, el autor afirma que ¡el partido republicano nacional fue fundado por Maximiliano Fernández en 1909!, y en lo que parece ser producto de un lamentable descuido de él y de la EUNED, fecha la batalla de tejar el 13 de marzo en vez del 13 de abril de 1948…UCR::Vicerrectoría de Investigación::Unidades de Investigación::Artes y Letras::Centro de Investigación en Identidad y Cultura Latinoamérica (CIICLA

Can sufficient preoperative information of intracranial aneurysms be obtained by using 320-row detector CT angiography alone?

Abstract Purpose To determine whether sufficient pre-surgical treatment information of unruptured intracranial aneurysms can be obtained by using 320-row detector CT angiography (CTA) alone. Materials and methods We enrolled 40 consecutive patients with unruptured intracranial aneurysms. All patients were prospectively conducted to perform 320-detector CTA as the only preoperative modality. Two blinded readers independently assessed CTA images. Interobserver agreement and the agreement between CTA and surgical findings were determined by calculating the j coefficient. The referring neurosurgeons judged the usefulness of the information provided by CTA for treatment decisions. Results All patients had surgery without intraarterial digital subtraction angiography. Agreement between CTA and surgical findings was excellent for the aneurysm location (j = 1.0) and good for the shape (j = 0.71), neck (j = 0.74) and its relationship with adjacent branches (j = 0.71). Information obtained with 320-detector CTA was highly useful for surgical treatment in 37 of 40 (93 %) patients, although small perforators deriving from the aneurysm in 2 cases were not fully visualized on CTA images. Conclusion In most patients with unruptured intracranial aneurysms, sufficient pre-surgical treatment information can be obtained by using 320-detector CTA alone