Free-reed organ pipes were introduced at the end of the 18 century and soon became popular across Europe, especially in Germany and Switzerland. As opposed to striking-reed pipes (boundor beating-reed pipes) the reed in free-reed pipes does not beat against the shallot, an orifice in the reed, when it is played. Instead it swings freely through a perforated rectangular plate of brass, like in r...

Buried pipes in the modern societies are considered as lifelines with a vital and essential role in the human life cycle. The performance of buried pipes is affected by many factors such as ground surface subsidence. In this paper, the effect of subsidence on pipelines is investigated using a three-dimensional numerical modeling developed in FLAC3D software for four types of most commonly used ...

In this article various pipes used for transporting of gas are introduced and pros and cons of each one are elucidated. The pipes are categorized in three different subgroups including metallic, polymeric and metallic-wire reinforced polymeric pipes. Metallic-wire reinforced polymeric pipes are nominated as the best option for usage in high pressure pipelines transporting natural gas. As a resu...

background: various chemicals are used to produce polymers ,leakage of polymer materials over the time , can cause health problems the aim of this research was to evaluate the leakage of heavy metals from the pvc and polypropylene pipes used in the water distribution system in isfahan. methods: four brands of pp pipes and two various types of pvc pipes were analyzed in this study. concentration...