Poling boards

Private Use Polymer A1 a subway under construction site. Polystyrene Foam used as poling board for reclaimed surface, ignited due to welding spark... 

Puncheon or prop (this is often placed against the poling boards or sheeting)... 

Poling boards are sheeting (1m by 5 m) which supports the sides of the trench. When poling boards are... 

Walings are horizontal beams used to support sheeting or poling boards against pressure from the trench walls. 

Fig. 1. Trench excavation in conjunction with support by poling boards and walings...

Poling boards dropped in or runners driven after frame placed in trench. Extra struts... 

Free water, the essential precondition for life as we know it, has recently been detected on Mars images taken by the high resolution stereo camera (HRSC) on board ESA s Mars Express spacecraft show a patch of water ice on the floor of an unnamed crater near the Martian north pole. Geomorphic studies indicate that the surface of Mars can be divided into two types (Jaumann et al 2002) ... 

The extensive layered sediments at the south pole, which contain water ice, will provide information on climatic variations. The subsurface sounding radar instrument SHARAD (Shallow Radar) on board the Mars Reconnaissance Orbiter carried out a detailed cartographic study of the subsurface at the Martian south pole. The data indicate that the sediments there have been subjected to considerable erosion (R. Seu et al 2007). The density of the material deposited at the Martian south pole was calculated by M. T. Zuber and co-workers by combining data from the gravitational field with those from various instruments on board the Mars Orbiter, they obtained a value of 1,200 kg/m3. This value corresponds to that calculated for water ice containing about 15% dust (Zuber et al 2007). 

The layers of sediment at the Martian south pole do not consist of pure ice they are interspersed by layers of dust. The latest data were obtained by the Mars Advanced Radar for Subsurface and Ionospheric Sounding apparatus (MARSIS) on board the Mars Express Orbiter. The radar waves from the instrument pass through the ice layers until they reach the base layer, which can be at a depth of up to 3.7 km. The distribution of the ice at the south pole is asymmetric, and its total volume has been estimated to be 1.6 x 106km3 this corresponds to an amount of water which would cover the whole planet with a layer 11 metres deep (Plaut et al., 2007). 

The north polar region of Mars consists of variously layered sediments, the upper layer consisting of water ice and thus having a high albedo. More detailed pictures ( 30 cm per pixel) were obtained from the High Resolution Imaging Science Experiment (HiRISE) on board the Mars Reconnaissance Orbiter (MRO). The sediment layers in this region are only about 10 cm thick but seem to be covered with a layer of dust. A detailed analysis of the HiRISE pictures of the north pole deposits indicate that complex, multi-step processes must have occurred at the polar icecaps (Herkenhoff et al., 2007). 

Carbon and carbon-glass composites are being used to make advanced-material fishing rods, bicycle frames, golf clubs, baseball bats, racquets, skis and ski poles, basketball back-boards, etc. These come in one color—black—because the carbon fibers are black. Even so, they can be coated with about any color desired. 

A most effective way to extend the Nation s timber supply is to use wood so that its service life is increased. The service life of wood in hazardous use conditions can be increased severalfold by the proper use of wood preservatives. It is estimated that the preservative treatment of railway ties results in an annual savings of 2.4 billion board feet of lumber and that, if utility poles were not treated, an additional 20 million mature trees of pole-stock quality softwoods would be needed each year simply as replacements for those destroyed by decay and termites. 

ASSERCULI or PALI — Small Planks, or Poles, on which miners sit for working the mine. ASSERES — Boards joined by their sides. 

The ensign itself is constructed of red, white and blue ribbed-weave silk, with a pole sleeve of white, plain-weave cotton it is approximately 211 X 117 cm in size (Figure 12). It was nailed to a wooden board, framed and glazed. 

Where possible the control of lighting fittings should be from a non-hazardous area, i.e. one adjacent to the hazardous area, using double pole switches. The supply neutral should be switchable. In rare situations this may not be practical in which case a switchboard or distribution board suitable for the hazardous area and the environmental conditions will need to be installed e.g. Zone 1, 1P55 or 56, with a suitable gas group and temperature class, see Chapter 10. 

Repeated flicking of centrifuge tubes with the finger tip is, at times, quite painful. To avoid repeated discomfort, a simple flicking device can be constructed with a shaded pole a.c. phonograph motor (cost about 3.00). The motor is screwed onto a wooden board and a cork stopper, bored slightly off-center, is fitted to the motor shaft. When in operation,... 

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