A continuous conversion technology from top coal caving into multi-slice mining for thick bifurcated coal seams

This paper presents a mining technology that enables the continuous conversion from top coal caving (TCC) to multi-slice mining (MSM). The technology helps operations overcome challenges with mining thick bifurcated coal seams, particularly the challenge of rock-parting seams affecting the caving of TCC mining methods. Findings show that the relationship between the rock-parting thickness and the caveability of top coal can be divided into 3 phases, including a complete caving phase, a transition phase, and a stable phase. This continuous conversion technology was applied in the Zhongwei Coal Mine in which TCC was used to extract the initial 260 m of the study area where the rock-parting seam was relatively thin before a transition to MSM was made due to the rock-parting seam becoming significantly thicker. The continuous conversion to MSM involved the working face advancing upward at an angle of 10 degrees until the rock-parting seam could serve as the immediate floor for the upper slice of the coal seam. The rock-parting seam floor also acted as the immediate roof for the working face of the subsequently mined lower slice. The application of this continuous conversion mining technology obtained good application results.

Rupture and Migration Law of Disturbed Overburden during Slicing Mining of Steeply Dipping Thick Coal Seam

Steeply inclined and thick coal seams in Huainan Panbei Coal Mine in Anhui Province, China, were analyzed by physical analog modeling, acoustic emission (AE), and distributed fiber sensing (DBS). The secondary deformation breakage law, sound, and light response characteristics in the rock mass deformation process induced by lower slice mining of steeply inclined coal seams were determined. The results show that the mutation of the hinged rock beam structure in the lower region and the cantilever beam structure in the upper region of the lower slice disturbed overburden is the main cause of the rupture of the workface roof. Based on the AE energy and distributed fiber strain response characteristics, the six stages of disturbed overburden instability in the lower slice and cyclic patterns of steeply inclined coal seams were revealed. The key prevention and control areas of the workface were found to be related to the disturbed high-level immediate roof rupture during the lower slice mining process, rupture of the disturbed main roof, and sliding of disturbed overburden. The three-stage AE positioning morphological characteristics and DBS response stepped jump patterns were analyzed in detail. The research results are considered instrumental in the combined AE and DBS monitoring of deformation and damage of rock and soil structures.

Effects of Ultrasound Treatments on Tenderness and In Vitro Protein Digestibility of New Zealand Abalone, Haliotis iris

Canned pāua, Haliotis iris, is a premium New Zealand product that is exported to Asia. The objective of this research was to investigate the effects of ultrasound treatments on pāua texture, microstructure and in vitro protein digestibility. Whole pāua meat was ultrasound-treated (20 kHz, 464 ± 9 W) for 5 min in water (with or without subsequent soaking in water at 4 °C for 24 h) or ultrasound-treated in 1% actinidin enzyme solution. Post-treatment cooking of canned pāua was done in a water retort at 116 °C for 30 min. All ultrasound-treated cooked pāua yielded lower slice shear force values (SSFV) than untreated canned and cooked samples. The lowest SSFV was attained when ultrasound treatment in water was followed by soaking at 4 °C for 24 h. The increased tenderness of ultrasound-treated pāua could be linked to disintegration of myofibers and formation of gaps between myofibers, as observed through histological analysis and transmission electron microscopy. Collagenous fragmentation was also observed, particularly in pāua ultrasonicated in enzyme solution. Raw pāua was found to be more digestible in terms of free amino N released during in vitro digestion than all cooked samples. However, cooked ultrasound pre-treated pāua was more digestible than the control cooked sample.

Ergonomic Analysis of An Affordance Tool for Modern Kitchen Knives

The focus of this study was on how different knife characteristics affect the consumer’s ability to slice vegetables. There are many variables to a knife and there are beliefs about what makes a better knife. There are two common multipurpose knives used for slicing vegetables: the chef knife and the santoku knife. For this study, an affordance tool was designed, manufactured and tested. This tool was designed to be placed on the knife to create an affordance for users to hold the knife in a pinch grip. This grip aligns the wrist and forearm and decreases fatigue and increases stability and control while cutting. The tool was tested with 16 participants to ensure it did not require more muscle activation, time, discomfort, or cause lower slice performance. Ultimately, the designed affordance tool provided an affordance without negatively effecting a cutting task compared to using a knife without the affordance tool.

Transport of intense beams with current-dependent initial conditions in linearly tapered solenoid channels

In electron beams where space charge plays an important role in the beam transport, the beams’ transverse and longitudinal properties will become coupled. One example of this is the transverse–longitudinal correlation produced in a current-modulated beam generated in a DC electron gun, formed through the competition between the time-dependent radial space charge force and the time-independent radial focusing force. This correlation will cause both the slice radius and divergence of the beam extracted from the gun to depend on the slice current. Here we consider the transport of such a beam in a linearly tapered solenoid focusing channel. Transport performance was generally improved with longer taper lengths, minimal initial correlation between slice divergence and slice current, and moderate degrees of initial correlation between initial slice radius and slice current. Performance was also generally improved with lower slice emittances, although surprisingly transport was improved by slightly increasing the assumed slice emittance in certain limited circumstances.

Study on Top Slice Irregular Destroyed Areas of Spatial Exploration Location and Mining Method

Slice mining, when mining lower slice need to consider on the effect of current face from top slice, especially when on top slice mining space irregular, it will make mining more difficult. Hair is drainage of these characteristics the lao keng kou mine by Geophysical means, take advantage of the characteristics of the water content in the mined-out area and media mutation specific master distribution of the residual top delamination, geophysical no damage proved an effective means of underground space structure and highly targeted research stoping methods, based on the conclusions formulated to ensure the safety and production measures in place to provide the necessary reference.

Geology and U–Pb geochronology of the Kipawa Syenite Complex — a thrust related alkaline pluton — and adjacent rocks in the Grenville Province of western Quebec

The Kipawa Syenite Complex, a thin, folded sheet of amphibole syenite, quartz syenite and minor nepheline syenite, lies along a west-vergent thrust separating a lower slice comprising the Kikwissi granodiorite and biotite tonalite dated at 2717 +15–11 Ma, and unconformably overlying metasedimentary rocks from an overlying slice containing the Red Pine Chute orthogneiss, an alkali granite gneiss, and the Mattawa Quartzite. The syenite complex, dated at 1033 ± 3 Ma, lies within the lower slice but has metasomatically altered the overlying slice. Texturally guided U–Pb spot analyses on partially metasomatised zircons from the alkali granite gneiss yield a cluster of 207Pb/206Pb ages at 1389 ± 8 Ma, interpreted as the time of igneous crystallization and four ages overlapping the time of syenite emplacement, interpreted as in situ, metasomatic growth. The highest structural slice comprises garnet amphibolite separated from lower slices by the Allochthon Boundary Thrust. Metamorphic grade increases upward from greenschist grade in the biotite tonalite to amphibolite grade (690 °C, 9 kbar (1 kbar = 100 MPa)) at the lower boundary of the alkali granite. Emplacement of the Kipawa Syenite Complex took place after assembly of the thrust stack had begun and after emplacement of the allochthon or hot slab responsible for the inverted metamorphic gradient. Origin of the syenite is tentatively ascribed to anatexis of material metasomatized by flow of alkaline solutions along a major shear surface. Crystallization of new zircon in the margins of the syenite shows that metasomatism continued from ca. 1035 to 990 Ma, redistributing alkalies, fluorine, rare-earth elements and zirconium.