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2. Measurement of binding kinetics using quantum plasmonic resonance sensing applied to HIV-1

Author

Mpofu, K. T., Lee, C., Maguire, G. E. M., Kruger, H. G., and Tame, M. S.

Subjects
Quantum Physics
Abstract

The work done in this paper is an extension of the work done by Mpofu et al in [1]. The motivation for this paper is to show the potential of quantum bio-sensing techniques in applications to complex viruses like the human immunodeficiency virus (HIV) and to show it's potential in binding reactions where the signal is small and can potentially be buried in noise. In this paper we show theoretically that using quantum states of light such as the Fock state improves the precision in the estimation of kinetic parameters measured from the sensorgrams produced by the Kretschmann conguration. Though the Fock state is not the only quantum state in this study we look only at the Fock state because it has been shown to be the state which offers the best enhancement [1]. We show here that the Fock state allows us to measure the parameters more accurately in comparison to the classical (Coherent) state of light. We consider in this paper a binding reaction involving HIV type 1 (HIV-1). Specifically we look at the binding reaction between a variant of HIV-1 protease and nelnavir which is an inhibitor. Such a study is also offers value for drug discovery research as it points to the development of new technologies which can be applied to testing the efficacy of new drugs. Quantum technologies can prove to be useful in the fight against the HIV pandemic and assist in the continual research towards the development of treatments and a cure., Comment: We would like to retract because there was a bit of miscommunication on my part when I submitted the paper. I had assumed that I had the green light to submit but the other authors needed more time to review

Published
2022

3. Experimental measurement of kinetic parameters using quantum plasmonic sensing

Author

Mpofu, K. T., Lee, C., Maguire, G. E. M., Kruger, H. G., and Tame, M. S.

Subjects
Quantum Physics, Physics - Optics
Abstract

Kinetic models are essential for describing how molecules interact in a variety of biochemical processes. The estimation of a model's kinetic parameters by experiment enables researchers to understand how pathogens, such as viruses, interact with other entities like antibodies and trial drugs. In this work, we report a simple proof-of-principle experiment that uses quantum sensing techniques to give a more precise estimation of kinetic parameters than is possible with a classical approach. The interaction we study is that of bovine serum albumin (BSA) binding to gold via an electrostatic mechanism. BSA is an important protein in biochemical research as it can be conjugated with other proteins and peptides to create sensors with a wide range of specificity. We use single photons generated via parametric down-conversion to probe the BSA-gold interaction in a plasmonic resonance sensor. We find that sub-shot-noise level fluctuations in the sensor signal allow us to achieve an improvement in the precision of up to 31.8% for the values of the kinetic parameters. This enhancement can in principle be further increased in the setup. Our work highlights the potential use of quantum states of light for sensing in biochemical research., Comment: 10 pages, 5 figures

Published
2021
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4. Measuring kinetic parameters using quantum plasmonic sensing

Author

Mpofu, K. T., Lee, C., Maguire, G. E. M., Kruger, H. G., and Tame, M. S.

Subjects
Quantum Physics, Physics - Optics
Abstract

The measurement of parameters that describe kinetic processes is important in the study of molecular interactions. It enables a deeper understanding of the physical mechanisms underlying how different biological entities interact with each other, such as viruses with cells, vaccines with antibodies, or new drugs with specific diseases. In this work, we study theoretically the use of quantum sensing techniques for measuring the kinetic parameters of molecular interactions. The sensor we consider is a plasmonic resonance sensor -- a label-free photonic sensor that is one of the most widely used in research and industry. The first type of interaction we study is the antigen BSA interacting with antibody IgG1, which provides a large sensor response. The second type is the enzyme carbonic anhydrase interacting with the tumor growth inhibitor benzenesulfonamide, which produces a small sensor response. For both types of interaction we consider the use of two-mode Fock states, squeezed vacuum states and squeezed displaced states. We find that these quantum states offer an enhancement in the measurement precision of kinetic parameters when compared to that obtained with classical light. The results may help in the design of more precise quantum-based sensors for studying kinetics in the life sciences., Comment: 18 pages, 14 figures, appendix

Published
2021
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29. Experimental measurement of kinetic parameters using quantum plasmonic sensing.

Author

Mpofu, K. T., Lee, C., Maguire, G. E. M., Kruger, H. G., and Tame, M. S.

Subjects
*PARAMETRIC downconversion, *PLASMONICS, *QUANTUM states, *PHOTONS, *PEPTIDES
Abstract

Kinetic models are essential for describing how molecules interact in a variety of biochemical processes. The estimation of a model's kinetic parameters by experiment enables researchers to understand how pathogens, such as viruses, interact with other entities like antibodies and trial drugs. In this work, we report a simple proof-of-principle experiment that uses quantum sensing techniques to give a more precise estimation of kinetic parameters than is possible with a classical approach. The interaction we study is that of bovine serum albumin (BSA) binding to gold via an electrostatic mechanism. BSA is an important protein in biochemical research as it can be conjugated with other proteins and peptides to create sensors with a wide range of specificity. We use single photons generated via parametric down-conversion to probe the BSA–gold interaction in a plasmonic resonance sensor. We find that sub-shot-noise-level fluctuations in the sensor signal allow us to achieve an improvement in the precision of up to 31.8% for the values of the kinetic parameters. This enhancement can, in principle, be further increased in the setup. Our work highlights the potential use of quantum states of light for sensing in biochemical research. [ABSTRACT FROM AUTHOR]

Published
2022
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37. Towards strategic management of drone application process and regulation in South Africa

Author

Mokoena, Q., Daniyan, I.A., Mpofu, K., and Abisuga, O.A.

Abstract

This paper discusses strategies to improve the application process for drones and Part 101 of the regulations for the approval of applications. Drones have the potential to transform the world by doing things differently and improving technology in the future. The use of drones is growing fast, and the need for control is important for reasons of safety and privacy. A qualitative method of data collection and analysis was used in this study, using the South African Civil Aviation Authority (SACAA) as a case study. Telephonic interviews were conducted to collect data from participants and to understand the issues affecting the drone application process. Drone operators were interviewed to collect data on the drone application process and the regulations. The researcher discovered that there were issues affecting the existing drone application and approval processes, such as restrictive regulations, the inclusion of manned aircraft requirements, slow issuing of Remotely Piloted Aircraft Systems operators' certificates, and the capital needed to enter the drone business. Recommendations are made to improve the drone application and approval processes. Hierdie artikel bespreek strategieë om die aansoekproses vir hommeltuie en art 101 van die regulasies vir die goedkeuring van aansoeke te verbeter. Hommeltuie het die potensiaal om die wêreld te transformeer deur dinge anders te doen en tegnologie in die toekoms te verbeter. Die gebruik van hommeltuie groei vinnig, en die behoefte aan beheer is belangrik vir redes van veiligheid en privaatheid. 'n Kwalitatiewe metode van data-insameling en -analise is in hierdie studie gebruik, met die Suid-Afrikaanse Burgerlugvaartowerheid (SABLO) as 'n gevallestudie. Telefoniese onderhoude is gevoer om data van deelnemers in te samel en om die kwessies rondom die hommeltuig-aansoekproses te verstaan. Hommeltuigoperateurs is onderhoude mee gevoer om data oor die hommeltuigaansoekproses en die regulasies in te samel. Die navorser het bevind dat daar kwessies was wat die bestaande hommeltuigaansoek- en -goedkeuringsprosesse beïnvloed, soos beperkende regulasies, die insluiting van bemande vliegtuigvereistes, die stadige uitreiking van RPAS-operateurssertifikate en die kapitaal wat nodig is om die hommeltuigbesigheid te betree. Aanbevelings word gemaak om die hommeltuigaansoek- en goedkeuringsprosesse te verbeter.

Published
2022

41. Assessing the sustainability of manufacturing processes in the manufacture of transport equipment, based on fuzzy grey relational analysis

Author

Olabanji, O.M and Mpofu, K.

Abstract

This paper presents a sustainability assessment of manufacturing processes for transport equipment, using fuzzy grey relational analysis. The metrics or sub-indicators for sustainability indicators and their relative applications in the manufacturing processes are used to create sustainability matrices, which are then compared with an ideal series in order to determine grades for the processes using the grey relational model. Grades in the form of values are determined for the performances of the manufacturing processes of four different kinds of transport equipment. The grades identified manufacturing processes in which the performance of the sustainability indicators could be improved. Hierdie artikel bied 'n volhoubaarheidsevaluering van vervaardigings-prosesse vir vervoertoerusting aan, deur gebruik te maak van wasige grys relasionele analise. Die maatstawwe of sub-aanwysers vir volhoubaarheidsaanwysers en hul relatiewe toepassings in die vervaardigingsprosesse word gebruik om volhoubaarheidsmatrikse te skep, wat dan met 'n ideale reeks vergelyk word ten einde grade vir die prosesse te bepaal deur die grys relasionele model te gebruik. Grade in die vorm van waardes word bepaal vir die prestasie van die vervaardigingsprosesse van vier verskillende soorte vervoertoerusting. Die grade het vervaardigingsprosesse geïdentifiseer waar die prestasie van die volhoubaarheidsaanwysers verbeter kan word.

Published
2022

44. Development and performance evaluation of a web-based feature extraction and recognition system for sheet metal bending process planning operations

Author

Murena, E., Mpofu, K., Ncube, A. T., Makinde, O., Trimble, J. A., Wang, Xi Vincent, Murena, E., Mpofu, K., Ncube, A. T., Makinde, O., Trimble, J. A., and Wang, Xi Vincent

Abstract

Sheet metal bending manufacturing companies require changeable and adaptable process planning systems to shorten the production cycle time and reduce operations costs. This is due to globalisation and the rapid change in market demands for sheet metal products. In light of this, this paper proposes a web-based feature extraction and recognition system. The system would ensure automated planning of various processes used by a bending machine to produce varieties of sheet metal products. The algorithms were implemented using C++ to produce the geometric and feature models used to extract, and recognise the bending features in various CAD files acquired from literature. Five (5) CAD files of various sheet metals were utilised to test the functionality of this system. The results from the feature recognition process have proven to be precisely what the user has designed and saved in the model file. Bend radius and bend angle. Finally, the developed system is able to transform a STEP file into a feature model and display the 3D CAD model within the least time. It is a cost-efficient standalone system that provides data storage, allows collaboration and data sharing. can be used anywhere where there is internet access., QC 20220308

Published
2021
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45. A distributive approach for position control of clamps in a reconfigurable assembly fixture

Author

Olabanji, O., Mpofu, K., Battaïa, Olga, and KEDGE, Connect Academ

Subjects
EHS, ComputerApplications_COMPUTERSINOTHERSYSTEMS, RAF, [SHS] Humanities and Social Sciences, hydraulic actuator, position control, reconfigurable assembly fixture, fuzzy-PID controller, electrohydraulic system, distributive modelling
Abstract

Hydraulic actuator is a type of clamp used in a reconfigurable assembly fixture for exact positioning and effective immobilisation of workpiece during the assembly process. However, due to their nonlinearity, there is a need to design a control system for their effective performance. This study presents a distributive approach to mathematical modelling and position control of multiple hydraulic actuators used as a clamping system in a reconfigurable assembly fixture. The electrohydraulic system is verified experimentally in order to observe the synchronisation of the hydraulic actuators. The mathematical model of the system is developed in the Simulink environment. A Simulink model of the system is developed from the mathematical model and simulated with a fuzzy-PID controller in order to obtain the response of all the actuators and other operating characteristics of the system. Simulation results are shown graphically in order to verify the theoretical development.

Published
2020

47. ASSESSING THE SUSTAINABILITY OF MANUFACTURING PROCESSES IN THE MANUFACTURE OF TRANSPORT EQUIPMENT, BASED ON FUZZY GREY RELATIONAL ANALYSIS.

Author

M Olabanji, O. and Mpofu, K.

Subjects
*GREY relational analysis, *SUSTAINABILITY
Abstract

This paper presents a sustainability assessment of manufacturing processes for transport equipment, using fuzzy grey relational analysis. The metrics or sub-indicators for sustainability indicators and their relative applications in the manufacturing processes are used to create sustainability matrices, which are then compared with an ideal series in order to determine grades for the processes using the grey relational model. Grades in the form of values are determined for the performances of the manufacturing processes of four different kinds of transport equipment. The grades identified manufacturing processes in which the performance of the sustainability indicators could be improved. [ABSTRACT FROM AUTHOR]

Published
2022
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48. Web-based process planning system concept selection using Weighted Decision Matrix and Analytical Hierarchy Process : A case study of sheet metal bending operations

Author

Eriyeti, M., Mpofu, K., Makinde, O., Trimble, J., Wang, Xi Vincent, Eriyeti, M., Mpofu, K., Makinde, O., Trimble, J., and Wang, Xi Vincent

Abstract

The demand for sheet metal bending products has pushed the sheet metal industry to adopt new process planning approaches that can transform the existing systems in order to improve efficiency and reduce costs during product design and manufacture. Sheet metal industries are still using traditional system planning methods, which have limited capacity to respond to rapid changes in market requirements. In light of this, this paper proposes a suitable web-based process planning system that can be used to effectively bend varieties of sheet metal products using various bending press machines. Three web-based process planning system concepts were formulated in this study and evaluated using various criteria. The result of the Weighted Decision Matrix (WDM) and the Analytical Hierarchy Process (AHP) analyses revealed that web-based process planning system concept Y with a cumulative assessment score of 1.90 and a priority assessment score of 0.637 is the suitable web-based process planning system that could be used to effectively bend varieties of sheet metals. This evaluation approach serves as a useful information for system designers in other manufacturing sectors, to select suitable systems capable of effectively carrying out their operations., QC 20200910

Published
2019
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