An innovative priming system - emulsion-based booster     

AK Mishra  D. Bhattacharya 《Fragblast: International Journal for Blasting and Fragmentation》2005,9(1):47-59

The mineral industry is leading towards a technology driven optimization process. Drilling and blasting are such unit operations in a mine, which can alter the balance sheet of the mine if not planned properly. The development, improvement and utilization of innovative technologies in terms of blast monitoring instruments and explosives technology are important for cost effectiveness and safety of mineral industries.

The ever-growing demand for minerals has compelled the industry to adopt large opencast projects using heavy equipment. This has necessitated use of a few hundred tonnes of explosives in each blast. The bulk delivered fourth generation explosives have solved the problem of explosive loading to a large extent as it provides improved safety in manufacturing, transportation and handling. Bulk delivered emulsion is non-explosive until gasification is complete and a large quantity of explosive can be transported and loaded into blast holes efficiently and with safety. The priming of bulk delivered explosives in Indian mines uses the conventional PETN/TNT-based boosters. The conventional booster possesses safety problems in terms of handling and use, so Indian Explosives Ltd has developed an emulsion-based booster (Powergel Boost).

This paper explores the potential of an emulsion-based booster used as a primer to initiate bulk delivered emulsion explosives used in mines. An attempt has been made at a comparative study between the conventional booster and the emulsion-based booster in terms of the initiation process developed and their capability of developing and maintaining a stable detonation process in the column explosives. The study has been conducted using a continuous velocity of detonation (VOD) measuring instrument, the VODMate two channel system manufactured by Instantel Inc. of Canada. During this study three blasts were monitored. In each blast two holes were selected for study, the first hole was initiated using a conventional booster while the other one used an emulsion-based booster. The findings of the study advocates that the emulsion-based booster is capable of the efficient priming of bulk delivered column explosive with a stable detonation process in the column.  相似文献   

The “geo” of United States national strategy     

Bernie Grover  M. Baruch Bernard 《GeoJournal》1993,31(2):141-148

The paper discusses the geo dimensions of the new world order, with particular emphasis on the increasing role of geoeconomics, and its impact on US national strategy. While the paper uses the US experience to illustrate the growing importance of geoeconomic considerations, the issues raised have direct bearing on many other nations throughout the world.US post Cold War strategy is determined by its three geo challenges. The most important is the geoeconomic challenge caused by the tri-polar division of the world along trading bloc lines, instant global communication and other technologies overcoming the constraints of physical geography, transnational corporations (TNCS) that are becoming supranational in character, and the emergence of a well educated global labor force. The geopolitical challenge is characterized by America's declining relative economic power and its traditional military allies having become economic competitors, while religious, ethnic, and regional tensions threaten its global interests. The third challenge is the military geography issue of effectively projecting power over distance, within the constraints of greatly reduced budgets and loss of overseas bases.  相似文献   

Shrubland encroachment in southern New Mexico,U.S.A.: An analysis of desertification processes in the American southwest   总被引：1，自引：0，他引：1  

Herbert D. Grover  H. Brad Musick 《Climatic change》1990,17(2-3):305-330

The area dominated by the shrubs creosotebush (Larrea tridentata) and mesquite (Prosopis glandulosa) in the American southwest has increased several-fold over the last century, with a corresponding decrease in areal coverage of productive grasslands and increased surface soil erosion throughout the region. The factors thought to be responsible for this regional shift in vegetation are: (1) overgrazing by domestic livestock; (2) fire suppression; and (3) historical changes in climate. We examine the evidence concerning each of these factors and develop a synthetic model outlining the principles affecting shrubland encroachment, which focuses on life history characteristics of the dominant shrubs and a number of positive biotic and edaphic feedback mechanisms contributing to their establishment and persistence. We conclude that the expansion of shrub dominance that has occurred over the last century may have been triggered by extreme live-stock overgrazing at the end of the nineteenth century, which coincided with rainfall regimes that were unfavorable for perennial grass growth. Hence, the landscape we observe today may be a product of positive feedback mechanisms triggered over a century ago by management practices that were uninformed with regard to the importance of historical climate patterns and the life history characteristics of important rangeland species. Our consideration of these issues also addresses potential land surface - climate interactions that could occur as a result of regional alterations in vegetation dominance and physiognomy.  相似文献   

Marine regression along parts of the Indian Coast during the Quaternary — A study using satellite images     

AK Gupta 《Journal of the Indian Society of Remote Sensing》1989,17(4):45-53

Features of marine regression along the Indian Coast during the Quaternary have been studied using the Landsat Imagery for the possible causes and mechanisms of their formation. The occurrence of these features, specially cheniers, is very prominent along the Krishna — Godavari coast. Variations in the inland distances of the cheniers at different locations along the coast indicate differential regressions of the coast at different places. Progradation of the coast and local uplift are identified as the main factors for the same. The topography of the shelf before the regression has played an important role in the development of the regression surfaces of varying widths and the spatial arrangement of the regression features. Morphostructural factors have hindered the formation of deltas along the western coast and also the formation of regression features. Some of the gently sloping coasts without the regression features are the active zones of sediment erosion. The study points to the possibility that some of the coasts/deltas are tectonically active zones. The Krishna Godavari delta is undergoing uplift and the coasts/deltas of the Sundarbans, Mahanadi, Kerala and Saurasthtra are undergoing down-warping. This fact needs to be confirmed using data form deep drillings, geophysical tests and other sources. The confirmation of these phenomena will have a significant effect on the depth of sediment deposition, their maturity and finally on the formation, occurrence and migration of hydrocarbons.  相似文献   

The collection and analysis of seismological data to detect possible violations of a nuclear test ban treaty     

F.H. Grover 《Physics of the Earth and Planetary Interiors》1979,18(2):135-142

In an experimental study of requirements for the operational monitoring of nuclear tests, seismological data collected by a small but globally distributed network of array stations are transmitted to Blacknest Data Analysis Centre.Important features of the experiment have been the improvement of data communications links with the cooperating agencies which operate the overseas arrays and with other national data centres, together with the creation of a data-base on computer files linked to the ARPANETWORK and accessible to collaborating organisations.A brief summary is given of some results of event analyses using data mainly from single recording points at the array stations. These are preliminary results from the network, preceding an eventual improvement in detection capability of the array stations which will ensue when the installation of on-line processing systems is completed.  相似文献   

A numerical determination of the effect of electric fields and charges on the efficiency with which cloud drops and small raindrops collide with aerosol particles     

S. N. Grover 《Pure and Applied Geophysics》1976,114(4):509-520

Summary Numerical calculations were carried out to determine the effect of a vertical electric field on the efficiency with which electrically charged or uncharged cloud drops and small raindrops of diameters ranging from 84 m to 1.248 mm collide with electrically charged or uncharged particles of density 2 gm/cm³ and diameters between 1 and 20 m. For this purpose, numerical flow fields about spheres of Reynolds numbers ranging from 1 to 400 were used to integrate the trajectory of the particle relative to the drop, and the force between two conducting spheres was used to represent the electrostatic force on the particle. The effect of thunderstorm strength electric charges and field on the collision efficiency was found to be highly significant for the smaller collector drops, and declined to insignificance for the largest collector drop.  相似文献   

A TECHNIQUE FOR PREPARING A POLISHED THIN SECTION FROM A DIAMOND-CONTAINING METEORITE     

Grover Moreland  Richard Johnson 《Meteoritics & planetary science》1977,12(4):397-398

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Minor inheritance inhibits the calibration of the 10Be production rate from the AD 1717 Val Ferret rock avalanche,European Alps          下载免费PDF全文

NAKI AKÇAR  SUSAN IVY‐OCHS  PHILIP DELINE  VASILY ALFIMOV  PETER W. KUBIK  MARCUS CHRISTL  CHRISTIAN SCHLÜCHTER 《第四纪科学杂志》2014,29(4):318-328

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Isolated Archosaur teeth from the green sandstone capping the Coralline Limestone (Bagh Group) of the Narmada valley: Evidence for the presence of pre‐Late to Late Maastrichtian abelisaurids in India          下载免费PDF全文

Guntupalli V.R. Prasad  Vishal Verma  Pooja Grover  Rajkumari Priyadarshini  Ashok Sahni  Ranjit S. Lourembam 《Island Arc》2016,25(6):410-420

Recent field prospecting in the Cretaceous sequences of the lower Narmada valley has led to the discovery of three isolated archosaur teeth from the upper part of marine Cretaceous rocks of the Bagh Group. The specimens were recovered by surface prospecting from an oyster‐bearing green sandstone bed occurring at the top of the Coralline Limestone (Coniacian) from a site near Phutibawri village, Dhar District, Madhya Pradesh, India. Of the three teeth recovered from this horizon, two are identified with abelisaurid dinosaurs and the third one with an indeterminate crocodile. The abelisaurid teeth conform to the premaxillary and maxillary tooth morphology of Majungasaurus and Indosuchus. Earlier reports of abelisaurid dinosaurs from India are from the Upper Cretaceous (Maastrichtian) Lameta Group of Jabalpur, Pisdura (Central India) and Balasinor (Western India) and Upper Cretaceous (Late Maastrichtian) Kallamedu Formation (South India). As no associated age diagnostic fossils are found, the specimens described here are considered to represent pre‐Late to Late Maastrichtian age based on the known ages of the underlying and overlying formations. The new finds, therefore, document stratigraphically the oldest occurrence of abelisaurid dinosaurs known from the Indian subcontinent.  相似文献   

Petrogenesis of the ü?kap?l? Granitoid and its Mafic Enclaves in Elmal? Area (Ni?de, Central Anatolia, Turkey)     

Hüseyin KURT  Kerim KO?AK  Kür?ad ASAN  Mustafa KARAKA? 《《地质学报》英文版》2013,87(3):738-748

The Late Cretaceous ükapili Granitoid including mafic microgranular enclaves intruded into metapelitic and metabasic rocks, and overlain unconformably by Neogene ignimbrites in the Ni de area of Turkey. It is mostly granite and minor granodiorite in composition, whereas its enclaves are dominantly gabbro with a few diorites in composition. The ükapili Granitoid is composed mainly of quartz, K-feldspar, plagioclase, biotite, muscovite and minor amphibole while its enclaves contain mostly plagioclase, amphibole, minor pyroxene and biotite. The ükapili Granitoid has calcalkaline and peraluminous (A/CNK= 1.0-1.3) geochemical characteristics. It is characterized by high LILE/HFSE and LREE/HREE ratios ((La/Lu) N = 3-33), and has negative Ba, Ta, Nb and Eu anomalies, resembling those of collision granitoids. The ükapili Granitoid has relatively high 87Sr/86Sr (i) ratios (0.711189-0.716061) and low εNd (t) values (-5.13 to -7.13), confirming crustal melting. In contrast, the enclaves are tholeiitic and metaluminous, and slightly enriched in LILEs (K, Rb) and Th, and have negative Ta, Nb and Ti anomalies; propose that they were derived from a subduction-modified mantle source. Based on mineral and whole rock chemistry data, the ükapili granitoid is H-(hybrid) type, post-collision granitoid developed by mixing/mingling processes between crustal melts and mantle-derived mafic magmas.  相似文献