Hydraulic forces caused by annular pressure seals in centrifugal pumps

The hydraulic forces caused by annular pressure seals were investigated. The measured inlet and exit loss coefficients of the flow through the seals were much smaller than the conventional values. The results indicate that the damping coefficient and the inertia coefficient of the fluid film in the seal are not affected much by the rotational speed or the eccentricity of the rotor, though the stiffness coefficient seemed to be influenced by the eccentricity

Developing Asia's Competitive Advantage in Green Products: Learning from the Japanese Experience

Right now, governments around the world are spending record amounts of money to kick-start their economies in response to the financial crisis. Fortunately, a great opportunity exists for this fiscal stimulus to be directed towards "green" economic growth, which can not only provide the new markets and jobs needed immediately for alleviating poverty, but also address the challenges of global warming. Working models already exist, proving that sustainable growth is possible. To achieve this will require social, technical and structural changes, as well as appropriate policies conducive to eco-innovation. For developing countries, there are lessons that can be learned from countries that have already gone through that process. The aim of this paper is to show what lessons can be learnt from the Japanese case. As the world's second largest economy, Japan is not only one of the most energy-efficient economies in the world; it also produces some of the world's leading green technologies. This paper focuses on current trends in the green product market and consumer behavior in Japan, which have been influenced by recent government policies, particularly the ¥15.4 trillion (more than US$100 billion) stimulus package. The aim of this paper is to provide some insight on, and present a repository of selected government policies promoting sustainable development. The scope of this paper will cover areas such as hybrid vehicles, renewable energy, energy efficient home appliances, and green certification schemes. It also provides a brief discussion on the environmental policies of the new Japanese government that came into power on 16 September 2009. The paper attempts to use the most recent data, from June to August 2009, however given the quickly-evolving global environment, these statistics may change drastically by the time this paper is presented.japanese government environmental policies; sustainable development; vehicle pollution policies

Detecting signals of weakly first-order phase transitions in two-dimensional Potts models

We investigate the first-order phase transitions of the $q$-state Potts models with $q = 5, 6, 7$, and $8$ on the two-dimensional square lattice, using Monte Carlo simulations. At the very weakly first-order transition of the $q=5$ system, the standard data-collapse procedure for the order parameter, carried out with results for a broad range of system sizes, works deceptively well and produces non-trivial critical exponents different from the trivial values expected for first-order transitions. However, a more systematic study reveals significant drifts in the `pseudo-critical' exponents as a function of the system size. For this purpose, we employ two methods of analysis: the data-collapse procedure with narrow range of the system size, and the Binder-cumulant crossing technique for pairs of system sizes. In both methods, the estimates start to drift toward the trivial values as the system size used in the analysis exceeds a certain `cross-over' length scale. This length scale is remarkably smaller than the correlation length at the transition point for weakly first-order transitions, e.g., less than one tenth for $q=5$, in contrast to the naive expectation that the system size has to be comparable to or larger than the correlation length to observe the correct behavior. The results overall show that proper care is indispensable to diagnose the nature of a phase transition with limited system sizes.Comment: 10 pages, 7 figures. One figure has been replaced to make our claim cleare

Finding the right policy to limit farms’ carbon emissions: the case of Brazil and Argentina

Over 80 per cent of our food’s emissions are generated inside the farm, mostly due to land clearing and emissions such as methane released by cattle. However, most governments don’t levy carbon taxes on their farmers, and much less so in developing economies. Tomás Domínguez Iino evaluates how effective such environmental tariffs are at reducing emissions, as well as their distributional impact across farmers in the context of Brazilian and Argentinian agricultural supply chains

Image analysis of characteristics of fluctuations of thermal mannequin's surface temperature distributions using time series infrared images

The final goal of this study was to propose a visualization method of heat transfer distributions over the human body in the indoor environment under cross ventilation conditions. Distributions of thermal mannequin's surface temperature fluctuations were visualized by image processing on infrared animations recorded at 30Hz sampling rate, and their characteristics were analyzed, as the first step of this study. At first, the influence of air velocity fluctuations on surface temperature fluctuations of thermal mannequin was visualized in the experimental room under cross ventilated cases and under air conditioned cases. An image processing method to transfer the infrared animations to power spectrum images was proposed in order to clarify the frequency of surface temperature fluctuations. And the distributions of sensible heat on thermal mannequin's surfaces were also visualized by classifying the pixels of power spectrum images by the cluster analysis and calculating the correction coefficient that was defined on each cluster for multiplying to roughly estimated value of sensible heat using the mean heat transfer coefficient

Muscarinic M2 acetylcholine receptor distribution in the guinea-pig gastrointestinal tract

In the enteric nervous system, acetylcholine is the most common neurotransmitter to induce gastrointestinal smooth muscle contractions. Cholinergic signaling is mediated by muscarinic acetylcholine receptors on the surface of smooth muscle cells. Five different muscarinic receptor subtypes (M1–M5) have been identified and characterized, all of which belong to the superfamily of the G-protein-coupled receptor. The muscarinic M2 acetylcholine receptor is the major muscarinic receptor subtype expressed by smooth muscle tissues in the gastrointestinal tract, where it is coexpressed with a smaller population of M3 receptor. In this study, we examined the immunohistochemical distribution of the M2 receptor using a specific antibody in the guinea-pig gastrointestinal tract. M2 receptor-like immunoreactivity was mainly observed as associated with smooth muscle cells in the gastrointestinal tract. M2 receptor-like immunoreactivity in smooth muscle cells was distributed throughout the cell membrane associated with caveolae. In the proximal colon, M2 receptor-like immunoreactivity in the smooth muscle cells was weak. In the small intestine, interstitial cells of Cajal that possessed neurokinin 1 receptor-like immunoreactivity had intense M2 receptor-like immunoreactivity. In the proximal colon, intramuscular and myenteric interstitial cells of Cajal exhibited M2 receptor-like immunoreactivity. These findings indicate that, in the gastrointestinal musculature, M2 receptors are distributed both in the smooth muscle cells and interstitial cells of Cajal, suggesting that the M2 receptor elicits smooth muscle cell contraction and the interstitial cells of Cajal are the sites of innervation by enteric cholinergic neurons