Review Article
Defect Assessment with DAC and DAM Methods; Measurement Accuracy Problems
Tranca Theodor*,
Tranca Mircea,
Cucuzel Cătălin Vasile
Issue:
Volume 10, Issue 4, December 2025
Pages:
89-95
Received:
26 May 2025
Accepted:
7 July 2025
Published:
9 October 2025
Abstract: Conventional pulse-echo ultrasonic inspection uses the ratio of the signal from a crack-like defect to the signal from a reference reflector as one factor which determines whether the flaw merits reporting, further sizing, and, possibly, removal. As these defects are smooth, on the scale of an ultrasonic wavelength, and generally flat, and also large relative to the wavelength, they can be successfully modelled using the geometrical theory of diffraction (GTD). GTD is a rapid method for evaluating the ultrasonic signal from a defect. The signal from the reference reflector is easy to calculate if the reflector is a side-drilled hole whose axis is normal to the ultrasonic beam axis and provided it is in the far field of the transducer. If the reference reflector is a flat-bottomed hole then prediction of the signal for non-normal angles of incidence is more difficult since the signal arises from the curved edge at the intersection of the flat bottom of the hole and its cylindrical side face.
Abstract: Conventional pulse-echo ultrasonic inspection uses the ratio of the signal from a crack-like defect to the signal from a reference reflector as one factor which determines whether the flaw merits reporting, further sizing, and, possibly, removal. As these defects are smooth, on the scale of an ultrasonic wavelength, and generally flat, and also lar...
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Research Article
The Establishment, Designation, and Management of an Artisanal and Small-Scale Gold Mining Cluster Zone: Case Study of the Odo Shakiso District, Oromia, Ethiopia
Misganu Kabeta*
,
Gera Techane,
Adisu Misgana
Issue:
Volume 10, Issue 4, December 2025
Pages:
96-109
Received:
28 August 2025
Accepted:
16 September 2025
Published:
17 October 2025
DOI:
10.11648/j.ijmpem.20251004.12
Downloads:
Views:
Abstract: Artisanal and small-scale mining (ASM) encompasses informal or formal operational mining activities that primarily use traditional tools and simple methods and techniques for resources of earth extraction, transportation and processing. ASM generally, requires minimal operational capital investment and is typically characterized by low capital, intensive labor worker and comprises an individual’s working as private or in family groups, as well as in partnerships, or as members of cooperatives in legal associations and enterprises. Ethiopia is one of a developing country, endowed with different mineral resources, where ASM was the most common practice among the people who live in rural parts of the country next to agriculture. Despite the ASM methods being traditional, mining activity practices were wasteful nature and abounding with so many obstacles and miners were making effort to continue their work of extract minerals primarily focuses on mining precious metals like gold, platinum, tantalum, lithium, copper, gemstones and semiprecious gemstones like opal, emerald, sapphire, aquamarine, amazonite, and other semiprecious type of gemstone, industrial minerals like clay, crushed stone, diatomite, gypsum, salt, sand, silica sand. A huge number of ASM’s in Ethiopia still face significant obstacles/challenges including a lack of the best mining and processing practices, low degree of capitalization and mechanization, limited financial access, lack of training on capacity building to increase production and productivity, inadequate environmental impact reduction measures, and limited access to marketing opportunities. Ethiopia is now implementing several initiatives/ measures which support the growth of ASM industry sector to revitalize the ASM with its main goal. To fully benefit from ASM, the government must work on ASM formalization through the novel idea of cluster and manage. To gradually transform/turn ASM into ASSM support them by suiting conditions on how to get equipments through rent approach, link with technology manufacturing industry and additionally provide training on sustainable mining and processing technology in the process of ASM transformation.
Abstract: Artisanal and small-scale mining (ASM) encompasses informal or formal operational mining activities that primarily use traditional tools and simple methods and techniques for resources of earth extraction, transportation and processing. ASM generally, requires minimal operational capital investment and is typically characterized by low capital, int...
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