237 research outputs found
Public Participation and the Governance of Mineral Resources in Zimbabwe
Public participation in policy issues by the locals is a crucial ingredient that guarantees the success of any policy decision, national project and public programme. Public participation should permeate every sphere of governance. In this vein, Zimbabwe is endowed with numerous mineral resources. The indigenous Zimbabwean are statutorily deemed as the owners of the mineral resources hence their participation in policy processes and spaces that relate to the governance of natural resources is pertinent. However, it was noted that the Zimbabwean population is not fully benefiting from the extraction of these mineral resources. The paper therefore explores the magnitude and essence of public participation in the governance of mineral resources in Zimbabwe. In achieving this, the paper is informed by Arnstein’s ladder of participation as the theoretical framework. In addition, data was gathered from documentary review and in-depth interviews with key informants. The study observed that public participation in respect of mineral governance can be undertaken through public hearing meetings, national budget consultative meetings and alternative mining indabas. However, the current level of participation is within the range of non-participation and lower tokenism. In addition, there is also lack of feedback and information flows in one direction from the Government officials to the citizens. The Government does not really take seriously the contributions from the public. The study therefore proffered some recommendations to enhance the levels of knowledge and participation by the public in the governance of mineral resources in Zimbabwe
Method for obtaining ingots of the A34 solder based on an investigation into the relation between the structure and properties of liquid and solid metals
A comparative analysis of the influence of the modifying method on the structure and phase composition of the ingots of the A34 solder is performed. Modification is performed by force of heating the melt to 1000°C and introducing the fine-crystalline remelt in an amount of 5% of the charge amount into the melt. The investigation is performed using DTA and metallographic analysis. The structure of the ingot of the A34 solder is additionally investigated at elevated temperatures (150 and 300°C) by the sc-AFM method using the NTEGRA Therma probe nanolaboratory, and recommendations are given to optimize the modes of casting and thermal treatment. © 2013 Allerton Press, Inc
Integrating Learning and Business Process Management
Recent research activities in the field of TEL have created a new awareness for intelligent learning infrastructures. To foster the usage of innovative TEL in the workplace, it must be integrated into organizational business operations and aligned with their learning requirements. Being the semantic interface of organizational ICT infrastructure, business processes represent the potential linkage between learning and business IS. Today, most organizations and their supporting ICT systems have incorporated processes as central objects of control. They manage their businesses along their processes, starting with process design over process execution up to process control and monitoring that feed back into improved business process design. As this process lifecycle has become the central instrument of BPM, it lends to be the vehicle for a businessintegrated learning management. This paper aims to position the thesis of a reciprocal relationship between business and learning processes being the prerequisite for prospective integrated workplace learning
Measurement of young's modulus and hardness of Al-50 wt % Sn alloy phases using nanoindentation
The nanoindentation method was used to measure the Young's modulus and hardness of the phases of the alloy Al-50 wt % Sn: α-aluminum and eutectic. Samples are obtained in different ways, i.e., traditionally via the transition of the melt into a homogeneous structural state by heating to a certain temperature, followed by cooling using the cooling rate greater by the order than that of the traditional method and via the addition of 0.06 wt % Ti and 1 wt % Zr to the binary alloy. It has been found that the most significant effect of the Al-50 wt % Sn phases on the Young's modulus is the transition of the melt into a homogeneous structural state and the introduction of Zr into the melt. As part of the mathematical theory of elasticity, a numerical evaluation of the interfacial pressure that arises due to the difference between Young's modulus of α aluminum and eutectic has been performed. The calculation has showed that the extra pressure is nine times less for the alloy formed through the transition of the melt into a homogeneous structural state than for the alloy produced via a traditional way. © 2013 Pleiades Publishing, Ltd
Viscosity and separation of Fe-Cu melts
A viscosimetric study of Fe-Cu melts is performed on heating and subsequent cooling of samples. The results of measurements in the above-liquidus part of the phase diagram are used to construct the boundaries of colloid-scale microheterogeneities in a melt. © 2013 Pleiades Publishing, Ltd
Viscosity and electrical resistivity of liquid cunial, cunialco, cunialcofe alloys of equiatomic compositions
The kinematic viscosity and electrical resistivity of equiatomic liquid alloys CuNiAl, CuNiAlCo, CuNiAlCoFe has measured during heating of the sample to 2070 K and subsequent cooling. We consider CuNiAl, CuNiAlCo, CuNiAlCoFe alloys of equiatomic compositions as the multi-principal element alloys (MPEAs), the complex concentrated alloys (CCAs), the high-entropy alloys (HEAs). The measuring results of the vickosity and the resistivity are discussed on base the available microgeterogenity concept. We searched the temperatureT*of the heating a melt for destroy of microheterogeneity. T* is the temperature of the beginning of the matching portion of the temperature dependence of the viscosity and resistivity which is obtained by heating and cooling. All the investigated melts demonstrated different temperature dependence of viscosity for heating and cooling. The temperature T*=1800 K were determined only for liquid alloy CuNiAl of equiatomic composition. For alloys CuNiAlCo, CuNiAlCoFe the coinciding part of the temperature dependences of the viscosity which are obtained by heating and cooling is absent. The results of viscosity are discussed within the theory of absolute reaction rates. Entropy of activation of viscous flow and free activation energy of viscous flow were determined by analyzing the temperature dependences of kinematic viscosity. The increasing of components quantity in the alloy leads to the increasing of the free activation energy of viscous flow and the volume per structural unit of the melt (ion, atom, or cluster). The measuring results of resistivity were interpreted using the Nagel-Tauc model. The temperature coefficient of resistivity (characteristic of the structural state of the melt) was determined. The temperature dependences of the CuNiAl liquid alloy resistivity measured upon heating to 2070 K and subsequent cooling do not coincide.The value of T*temperature for alloy CuNiAl of equiatomic composition is 1850 K. For CuNiAlCo, CuNiAlCoFe alloys the temperature dependences of the resistivity which are obtained by heating and cooling are coinciding. This means that destroy of microheterogeneity for melts after heating up to 2070K did not occur. The temperature coefficient of resistivity of the CuNiA liquid alloy irreversibly decreases when it heated to a temperature of 1850 K.This is evidence of the destruction of microheterogeneity with the formation of a homogeneous solution at the atomic level. The increasing of components quantityin the alloy leads to a decreasingof thetemperature coefficient of the resistivity (in cooling moda). According to the ideas of Nagel and Tauk, an irreversible decrease of the temperature coefficient of the specific resistance of the melt indicates an increase in the volume per structural unit of the melt (ion, atom, or cluster). © 2019, Technical University of Kosice. All rights reserved.Authors are grateful for the support of experimental works by Act 211 Government Russian Federation, contract 02.A03.21.0006
Influence of copper additives on the viscosity and stratification of iron melt
Viscosimetric data are obtained for Fe-Cu melts in heating and subsequent cooling of samples with 0-10 wt % Cu. Above the liquidus in the resulting phase diagram, the boundaries of the region where microheterogeneities of colloidal scale exist in the melt are found. © 2013 Allerton Press, Inc
The Leu22Pro tumor-associated variant of DNA polymerase beta is dRP lyase deficient
Approximately 30% of human tumors characterized to date express DNA polymerase beta (pol β) variant proteins. Two of the polymerase beta cancer-associated variants are sequence-specific mutators, and one of them binds to DNA but has no polymerase activity. The Leu22Pro (L22P) DNA polymerase beta variant was identified in a gastric carcinoma. Leu22 resides within the 8 kDa amino terminal domain of DNA polymerase beta, which exhibits dRP lyase activity. This domain catalyzes the removal of deoxyribose phosphate during short patch base excision repair. We show that this cancer-associated variant has very little dRP lyase activity but retains its polymerase activity. Although residue 22 has no direct contact with the DNA, we report here that the L22P variant has reduced DNA-binding affinity. The L22P variant protein is deficient in base excision repair. Molecular dynamics calculations suggest that alteration of Leu22 to Pro changes the local packing, the loop connecting helices 1 and 2 and the overall juxtaposition of the helices within the N-terminal domain. This in turn affects the shape of the binding pocket that is required for efficient dRP lyase catalysis
Influence of defects on the ductility of liquid 9X2MΦ and 75X3MΦ steel
Viscosimetric data on liquid 9X2MΦ and 75X3MΦ steel taken from working rollers of a reversible rolling mill with different ultrasonic behavior illustrate the influence of defects recorded in ultrasound monitoring on the temperature and time dependence of the liquid steel's kinematic viscosity. A Krautkremer ultrasonic defectoscope is employed in monitoring. The viscosity of the liquid steel is measured by means of damping torsional oscillations of a crucible with melt in heating and subsequent cooling in the range 1500-1580°C. © 2013 Allerton Press, Inc
Examining the structure of mill rolls made of 9X2MΦ and 8X3CΓΦ steels using the ultrasonic method for quality control
The microstructure of specimens of 9X2MΦ and 8X3CΓΦ steels taken from working rolls of a reversing mill was examined. A correlation between characteristics of the crystal structure of the metal and the intensified attenuation of ultrasonic waves was found. Ultrasonic inspection was carried out using an ultrasonic flaw detector (Krautkramer Co.). The microstructure was examined by means of traditional metallographic analysis methods, which were implemented using a scanning electron microscope; X-ray spectral microanalysis and electron backscatter diffraction were used. The morphology and elemental composition of discontinuity flaws were studied; as well, phase maps, crystallite misorientation histograms, and Taylor factor maps were plotted for specimens taken from the defect zone of a 9X2MΦ steel working roll. © 2013 Pleiades Publishing, Ltd
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