Jumat, 28 Desember 2018

Minggu, 02 Desember 2018

Sabtu, 24 November 2018

Senin, 17 September 2018

Ceiling Track Lighting as Modern Lamps in Futuristic Interior Design

  /   Tidak ada komentar   
There are some awesome ceiling track lighting ideas which can increase the room performance. They are applied in the some rooms like kitchen, living room, dining room and etc. Usually, this lamp style is applied into the kitchen. Now we will show you the appearance of the kitchens and the billiard room which apply this lamp design. There are many lamp styles here. If you love this lamp design, you can see them through these pictures here.

Here are the pictures of the rooms which apply this lamp model. See the kitchen. This kitchen applies kitchen ceiling track lighting. These are created with silver lampshade with stainless stick. Under this lamp is the black cabinet with glossy countertop. There are some colorful cafe chairs next to the cabinet. It is modern kitchen. They stand on the oak flooring. See the next kitchen. The lamp is designed with white lampshade. The cabinet is designed with black countertop. There are sink and faucet on this cabinet.
Then, the next kitchen is designed in simple concept. The wooden storage and wooden cabinet are applied in this kitchen. The cabinet is designed with white marble countertop. This cabinet is designed with double bowl sink and stainless faucet. In the drawer, you can put the books in that cabinet. These are standing above the oak flooring. Above the cabinet are the lamps. They are orange lampshades.
The next room is the billiard room. The billiard is designed with some furniture designs. The wooden billiard room stands in the middle of the room. Above the billiard are the glass lamp bulbs. There are some brown armchairs around this billiard. In front of the armchairs is the wooden table. There is fireplace in this room. This is designed by glass fireplace screen. This is one of drop ceiling track lighting models with great inspiration design.


Umbrella Table with Patio Furniture for Modern Outdoor Living Space

  /   Tidak ada komentar   
This time, we will give special performance of umbrella table. There are kind of special furniture designs. They can create lovely rooms. They can be applied into interior and exterior home performances. Do you want to see these lovely rooms to increase your room performance? If the answer is yes, you can see these pictures here. They are very beautiful rooms. Absolutely, they are so cheerful and wonderful. Please take a look for these pictures to get more detail.

These are the pictures which we are talking about. See, the room is designed in the living room. This room has blue bed. There are some blue pillows on this bed. It is comfortable bed for kids. This room has glass windows. This room is decorated with white wall and oak flooring. This room has one of beautiful umbrella table decorations in the world. See the bedroom then. The bed is created with white bed, flower pattern, pattern pillows and white headboard.
See the performance of the lovely living room. This is designed with white armchairs with white pillows. In front of them are the wooden tables. In the corner of the room is small table. There are beautiful flowers on the glass vase. In front of them is the white storage. In the middle of the storage is television screen. This room is designed with oak ceiling. This room has unique lampshade with candles in the inside.
Let’s see the performance of the share bedroom. The white beds stand in the corner of the room. These beds are designed with flower pattern blanket. There are some cute pattern pillows. Then, this room is designed with flower wallpaper. Then, the next room is living for the girl. The pink corner sofa stands on the super soft white feather carpet. This room is decorated with blue wall. The last picture shows umbrella table stands with natural sensation.


Overburden strata failure due to mining

  /   Tidak ada komentar   
China has developed some specific methods of coal mining and experimental techniques under aquifers and surface water. Over the last 40 years, about 1000 longwall faces were extracted under surface and ground water, liberating millions of tons of coal reserves without disastrous consequences. Since coal extraction enhances hydraulic conductivity, it is desirable to determine accurately pre- and post-mining hydraulic conductivities in the overburden strata. To measure these conductivities, boreholes are drilled pre- and post-mining either on the surface or in underground observing roadways. The flow rate or circulation loss along the borehole during drilling is measured by pumping drilling mud into the borehole. Well logs are also applicable for the determination of mining induced fractures and permeability changes (Peng et al. 2002a).
In general, two failure zones that affect strata hydraulic conductivity are formed overlying the mined area: a caved zone and a water-conducting fractured zone (Liu et al. 1981, Zhang and Shen 2004). For mining under aquifers, the water-conducting fractured zone is more interesting, since it provides access for water inflow into the mine workings because of hydraulic conductivity enhancement in this zone. From in-situ testing of borehole flow rate, the water-conducting fractured zone can be divided into the following three subzones (Fig. 9.1):
(1) Slightly fractured subzone. Only little fractures are induced in the strata. Compared to the original strata, hydraulic conductivity in this zone increases slightly. The fluid circulation loss rates in the observing borehole are less than 0.1 l/s m;
(2) Moderately fractured subzone. The strata only have partial bed separations and fractures. Hydraulic conductivity in the strata increases moderately. The circulation loss rates are between 0.1 and 1.0 l/s m;
(3) Severely fractured subzone. Most of the strata have been fractured, and the fractures are interconnected. Hydraulic conductivity in the strata increases dramatically. The circulation loss rates are greater than 1.0 l/s m.
Field observations by circulation loss measurements in boreholes while drilling have shown that the strata failure characteristics differ considerably for different inclinations of the extracted seams. For flat or slightly inclined coal seams (the dip angle, D < 30q), the profile of the water-conducting fractured zone is broad in section with extended lobes over the headgate and tailgate, as shown in Fig. 9.2. For strong rocks, the failure zone has a different characteristic, as shown in Fig. 9.3, which is that the failure zones are much higher in the vertical direction and narrower in section.
For inclined coal seams (30q
A considerable number of in-situ observations have shown that heights of strata caved and fractured zones in the overburden formation depend primarily on the lithology and strength of the overlying strata, as well as the inclination of the extracted seam. The following formulae have been obtained according to in-situ observations in thousands of longwall faces (Liu et al. 1981, Bai and Elsworth 1990, Zhang and Shen 2004).
For mining under aquifers, it is desirable to avoid the extra expense of strata dewatering. This can only be achieved when aquifers are located outside the water-conducting fractured zone. In this case, water inflow into the mine workings does not increase. When an aquifer lies within the fractured zone, but outside the caved zone, excessive groundwater discharge to the mine occurs (according to the mining experiences in China); however, the sand in the unconsolidated aquifer does not flow into the mining area. When an unconsolidated aquifer is situated within the caved zone, both water and sand can rush into the mining area, and this may even cause disastrous consequences, if the aquifer is very permeable and strongly waterbearing.
The Daliuta coal mine, affiliated with the Shenhua Group, is located in ShenFu Coalfield, Northern Shaanxi Province and on the southwestern bank of the Yellow River, Northern China (Fig. 9.7). It is one of the major coal mines in China. This coalfield consists of nearly flat-lying beds of Jurassic coal measure. The thickness of the primary coal seam, No. 2, is approximately 4 m with the roof consisting of medium-grained sandstones. The overlying coal measures are 19 to 65 m in thickness, comprising weak, weathered strata in the uppermost reaches. The bedrock is overlain by unconsolidated alluvium comprising mixed impermeable clay layers with water-bearing sands and gravels. The alluvium is generally 38 to 43.4 m in thickness, in which one aquifer underlies lowermost in the unconsolidated overburden. The total depth of cover for seam No. 2 ranges approximately from 20 to 100 m. Comprehensive mechanized longwall mining with full caving is used in the coal extraction.
The coalfield has a very dry temperate climate and is situated in the southeastern border of the Maowusu Desert. Most of the surface is covered by sand, in which little vegetation exists. The water resource is very precious in this region. Only one perched aquifer in the Quaternary alluvium overlies directly on the coal measure. Therefore, the protection of the water resource and mining safety from groundwater hazards are common concerns of both the mine operator and government.

Support and Reinforcement in the Mining Cycle

  /   Tidak ada komentar   
The most commonly used mesh is probably welded mesh made of approximately 5 mm thick steel wire and having 100 mm square openings. The steel wire may be galvanised or not. The alternative has been an interwoven mesh known as chain link mesh. The disadvantage of traditional chain link mesh compared with weld mesh has been the difficulty of applying shotcrete successfully through the smaller openings available. This difficulty has now been overcome in a high strength, light weight chain link mesh with 100 mm openings which is easy to handle and can be made to conform to uneven rock surfaces more readily than weld mesh.
A feature of this mesh is the fact that the intersections of the wires making up the squares in the mesh are twisted rather than simply linked or welded. Roth et al. (2004) describe static and dynamic tests on this mesh. Mesh of this type is being used successfully at the Neves Corvo Mine, Portugal, where it has been particularly successful in rehabilitating damaged excavations. Li et al. (2004) report that this mesh is being trialled by St Ives Gold, Western Australia. Tyler & Werner (2004) refer to recent trials in sublevel cross-cuts at the Perseverence Mine, Western Australia, using what a similar Australian made high strength chain link mesh. It is understood that completely satisfactory mechanised installation methods have yet to be developed.
In this symposium, Hadjigeorgiou et al. (2004) and Van Heerden (2004) discuss the use of cementitious liners to support, protect and improve the operational performance of ore passes in metalliferous mines. One of the benefits of cementitious liners is the corrosion protection that they provide to the reinforcing elements. Both papers emphasise the need to consider the support and reinforcement of ore passes on a cost-effectiveness basis taking into account the need to rehabilitate or replace failed passes. The author has had the experience of having to recommend the filling with concrete and re-boring of critical ore passes that had collapsed over parts of their lengths.
Although their use was referred to at the 1999 symposium, there have been significant developments in the use of thin, non-cementitous, spray-on liners (TSLs) since that time (e.g. Spearing & Hague 2003). These polymer-based products are applied in layers of typically 6 mm or less in thickness, largely as a replacement for mesh or shotcrete. Stacey & Yu (2004) explore the rock support mechanisms provided by sprayed liners.
The author’s experience at the Neves Corvo Mine, Portugal, is that TSLs are useful in providing immediate support to prevent rock mass deterioration and unravelling in special circumstances (Figure 2), but that they do not yet provide a cost-effective replacement for shotcrete in most mainstream support applications. In some circumstances, they can be applied more quickly than shotcrete and may be used to provide effective immediate support when a fast rate of advance is required. Recently, Archibald & Katsabanis (2004) have reported the effectiveness of TSLs under simulated rockburst conditions.
Overcoming the limitations and costs associated with the cyclic nature of underground metalliferous mining operations has long been one of the dreams of miners. More closely continuous mining can be achieved in civil engineering tunnelling and in longwall coal mining than in underground hard rock mining. Current development of more continuous underground metalliferous mining systems is associated mainly, but not only, with caving and other mass mining methods (Brown 2004, Paraszczak & Planeta 2004).
Several papers to this symposium describe developments that, while not obviating the need for cyclic drill-blast-scale-support-load operations, will improve the ability to scale and provide immediate support and reinforcement to the newly blasted rock. Jenkins et al. (2004) describe mine-wide trials with hydro-scaling and in-cycle shotcreting to replace conventional jumbo scaling, meshing and bolting at Agnew Gold Mining Company’s Waroonga mine, Western Australia. Neindorf (2004) also refers to the possibility of combining hydro-scaling with shotcreting to develop a new approach to continuous ground support in the development cycle at Mount Isa. These developments form part of the continuous improvement evident in support and reinforcement practice in underground mining.
As was noted at the 1999 symposium, although backfill has been used to control displacements around and above underground mining excavations for more than 100 years, the great impetus for the development of fill technology came with the emergence of the “cut-and-fill era” in the 1950s and 60s (Brown 1999a). It was also noted that fill did not figure prominently in the papers presented to that symposium. A few years earlier, paste fill made from mill tailings and cement and/or other binders, had been developed in Canada (Landriault 2001). Since that time, the use and understanding of paste fill have increased dramatically, so much so that Belem et al. (2004b) suggest that it is “becoming standard practice in the mining industry throughut the world”.
Cemented paste fill is now used with a range of mining methods including sublevel open stoping, cut-and-fill and bench-and-fill. In some applications, it is necessary that unsupported vertical paste fill walls of primary stopes remain stable while secondary stoping is completed. In common with Landriault (2001) and Belem et al. (2004a), the author has had success using the design method proposed by Mitchell (1983). A particular requirement in some applications is to include enough cement to prevent liquefaction of the paste after placement (Been et al. 2002).
In two papers to this symposium, Belem et al. (2004a, b) discuss a range of fundamental and applied aspects of the use of cemented paste fill in cut-and-fill mining generally, and in longhole open stoping at La Mine Doyen, Canada. Varden & Henderson (2004) discuss the use of the more traditional cemented rock fill to fill old underground mining voids at the Sons of Gwalia Mine, Western Australia.