The Phenomenon of Unidirectional Circulating Flow in an Oscillating Heat Pipe

The phenomena of two different types of unidirectional circulating flow pattern in a copper oscillating heat pipe (OHP) were firstly discovered and investigated. The OHP has six turns and three sections: evaporator, condenser and adiabatic sections with lengths of 40 mm, 64 mm, and 51 mm, respectively. R152a was used as the working fluid, the effects of the tilt angle from 0° to 90° and the heat input on the flow and heat transfer of the working fluid in OHP was studied. The experimental results showed that (1) the OHP charged with R152a can form a unidirectional circulating flow at any tilt angle under certain heat input, and the unidirectional circulating flow become steady as the heat input increases; (2) another type of circulating flow was found in the same OHP as the heat input increased to a relative high level, the difference between the two types of circulating flow is that the liquid slugs move forward with or without back forward oscillating movement; (3) the unidirectional circulating flow of the working fluid without back forward oscillating movement in the OHP significantly enhance the heat transfer of OHP.

The Relationship between Economics Growth and Energy Consumption in China-A Empirical Analysis Based on Energy Kuznets Curve

These paper investigated the relationship between economics development and energy demands based on Energy Kuznets Curve (EFC) in China. The results show that, the prospects of economics and energy demand in China in further will undergo three important stages to 2050.The peak of energy demand maybe around 2035 and the corresponding total energy demand maybe amount 5.7 billion tce. In 2035, the GDP per capital maybe about 17000 (2005 US$) and the urbanization will reach a relative high level. It is urgent for China to take actions to curb the increasing total energy consumption.

A vállalati logisztikai költségek a magyarországi kis- és középvállalkozások körében végzett felmérés tükrében (Corporate logistics costs of the Hungarian small- and medium-sized enterprises)

A cikk a magyarországi kis- és középvállalkozások logisztikai költségeit vizsgálja a nemzetközi kutatások tükrében és a 2009-es közel kétezer hazai KKV-re kiterjedő „Vállalkozások helyzetének felmérése” alapján. A hazai logisztikai költségeket leginkább a vállalatméret és az ágazat befolyásolja. A magyarországi kis- és középvállalkozások ki nem szervezett szállítási és raktározási tevékenységei a hazai fuvarozóknak és raktárszolgáltatóknak jelentős piacbővülést jelenthetnének. Ez azonban csak látens piacbővülés, mivel a hazai KKV-k nem tervezik, hogy szállítási és raktározási tevékenységeiket nagyobb arányban szervezzék ki. Ez részben azzal magyarázható, hogy a feldolgozóipari, mezőgazdasági és kereskedő kis- és középvállalkozások viszonylag nagy arányban tekintik a logisztikát alapvető képességnek. Nemzetközi viszonylatban a magyarországi KKV-k magas logisztikai költségszintekkel szembesülnek, melynek mérséklésével az adminisztrációs terhek csökkentéséhez hasonló megtakarítást lehetne elérni. ____ This article examines total logistics costs and its components of the Hungarian small- and medium-sized enterprises in the light of international researches. It shows that company-size and its sector are the most important drivers of logistics costs and its components according to „Survey of position of enterprises”, which covered nearly 2000 Hungarian SMEs in 2009. It also proves that transport and warehousing demand of the Hungarian SMEs means a significant market growth for national carriers and warehouse providers. It is only a latent growth, because the Hungarian SMEs do not plan to outsource their transport and warehouse activities in a greater extent. The relative high level of logistics as a core competence among processing industry, agriculture and trade SMEs can be a partial explanation to this. The Hungarian small- and medium-sized enterprises face with high logistics costs in international comparison. Its reduction may bring similar savings as reduction of administrative burdens.