Applied Physics Publications

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Application of Remote Sensing and Geographical Information Systems in Determining the Groundwater Potential in the Crystalline Basement of Bulawayo Metropolitan Area, Zimbabwe
(Scientific Research, 2013) Chuma, Constant; Hlatywayo, Dumisani J.; Orimoogunje, Oluwagbenga O.I.; Akinyede, Joseph O.
This study is concerned with the identification and delineation of aquiferous zones for potential groundwater development across Bulawayo Metropolitan from remotely sensed data and geological inference. Attempts have been made to review literatures on groundwater exploitation in the study area and the constraints to effective and sustainable management of underground water in the study area. Remote Sensing and Geographical Information Systems (GIS) is useful in the recognition and delineation of aquiferous zones for potential groundwater in crystalline basement aquifers. LANDSAT ETM+ image, SRTM data, aeromagnetic data and other ancillary data sets were utilized to extract information on the groundwater storing controlling features of this study area. Six thematic maps were produced from remote sensing data and other ancillary data - Land use/landcover, drainage density, slope map, contact density, lithology and lineament density. GIS modeling technique of the index overlay method was used to produce the groundwater potential map. The study revealed that the regional lineaments correlate with faults, fracture zones, and lithological contrasts along fold belts in the crystalline basement rocks, while the main direction of faulting and jointing is north-north-west to north with several faults oriented, to the north-north-east, parallel to the Great Dyke. Proximity to lineaments is the highest zone of increased porosity and permeability which in turn have a greater chance of accumulating groundwater. The results have shown massive spatial variability of ground water potential ranging from very good to poor. The variability closely followed variations in the structures, geology, topography/slope, drainage density and land use/land cover in the project area. This work is a reconnaissance which needs to be validated by the use of high-resolution terrain data and satellite imagery and the quantitative analysis should be done using geophysical and hydrogeological surveys.
Apsidal Precession of the Outer Solar Planetary Orbits due to the Pioneer Anomaly
(Elsevier, 2017-01) Nyambuya, G. G.
Despite the now common position that the Pioneer anomaly is not a real gravitational effect but an effect due to the on-board thermal recoil forces – for curiosity’s sake, we here take the suggestion of Nyambuya (2015) where it has been assumed that the Pioneer anomaly – can, in-principle, be attributed to a gravitational effect due to these spacecrafts accreting some material from a rarefied Interplanetary Medium (IPM) in the domain where the Pioneer anomaly has manifested [20AU . r . 70AU]. If this assumption is correct, then, the expected Pioneer acceleration of these spacecrafts maybe much smaller than the Pioneer acceleration to cause as noticeable apsidal precession of the outer Solar planets Uranus, Neptune and Pluto, thus making it difficult to ruleout a gravitational origin of the Pioneer anomaly.
Are Flyby Anomalies an ASTG Phenomenon? (ASTGII)
(arXiv, 2010-05-10) Nyambuya, G. G.
This reading expounds with expediency on the recently proposed Azimuthally Symmetric Theory of Gravitation(ASTG) set-up earlier. At its inspection,it was demonstrated that the ASTG is capable (among others solar anomalies) of explaining the precession of the perihelion of solar planets. In the present, we show that the ASTG is capable of explaining the puzzling observation of ﬂyby anomalies, i.e. the anomalous asymptotic speed increases of the osculating hyperbolic speed excess. It is shown that these ﬂyby anomalies occur naturally in the ASTG. We derive the empirical formula proposed by Andersonet al. in 2008,which up to now has no physical or foundational basis except that experience suggest it. If the ASTG model is correct,then for the ﬁrst time the Andersonet al.formula is given a physical meaning.
Are Photons Massless or Massive?
(Scientific Research, 2014) Nyambuya, G. G.
Prevailing and conventional wisdom as drawn from both Professor Albert Einstein’s Special Theory of Relativity (STR) and our palatable experience, holds that photons are massless particles and that, every particle that travels at the speed of light must – accordingly, be massless. Amongst other important but now resolved problems in physics, this assumption led to the Neutrino Mass Problem – namely, “Do neutrinos have mass?” Neutrinos appear very strongly to travel at the speed of light and according to the afore-stated, they must be massless. Massless neutrinos have a problem in that one is unable to explain the phenomenon of neutrino oscillations because this requires massive neutrinos. Experiments appear to strongly suggest that indeed, neutrinos most certainly are massive particles. While this solves the problem of neutrino oscillation, it directly leads to another problem, namely that of ‘‘How can a massive particle travel at the speed of light? Is not this speed a preserve and prerogative of only massless particles?” We argue herein that in principle, it is possible for massive particles to travel at the speed of light. In presenting the present letter, our hope is that this may aid or contribute significantly in solving the said problem of “How can massive particles travel at the speed of light?”
Are Photons Massless or Massive?
(Scientific Research, 2014) Nyambuya, G. G.
Prevailing and conventional wisdom as drawn from both Professor Albert Einstein’s Special Theory of Relativity(STR) and our palatable experience, holds that photons are massless particles and that, every particle that travels at the speed of light must – accordingly, be massless. Amongst other important but now resolved problems in physics, this assumption led to the Neutrino Mass Problem – namely, “Do neutrinos have mass?” Neutrinos appear very strongly to travel at the speed of light and according to the afore-stated, they must be massless. Massless neutrinos have a problem in that one is unable to explain the phenomenon of neutrino oscillations because this requires massive neutrinos. Experiments appear to strongly suggest that indeed, neutrinos most certainly are massive particles. While this solves the problem of neutrino oscillation, it directly leads to another problem, namely that of ‘‘How can a massive particle travel at the speed of light? Is not this speed a preserve and prerogative of only massless particles?” We argue herein that in principle, it is possible for massive particles to travel at the speed of light. In presenting the present letter, our hope is that this may aid or contribute significantly in solving the said problem of “How can massive particles travel at the speed of light?”
Avoiding Negative Probabilities in Relativistic Quantum Mechanics.
(SciRes, 2013-03-21) Nyambuya, G. G.
As currently understood since its discovery, the bare Klein-Gordon theory consists of negative quantum probabilities which are considered to be physically meaningless if not outright obsolete. Despite this annoying setback, these negative probabilities are what led the great Paul Dirac in 1928 to the esoteric discovery of the Dirac equation. The Dirac equation led to one of the greatest advances in our understanding of the physical World. In this reading, we ask the seemingly senseless question, “Do negative probabilities exist in quantum mechanics?” In an effort to answer this question, we arrive at the conclusion that depending on the choice one makes of the quantum probability current, one will obtain negative probabilities. We thus propose a new quantum probability current of the Klein-Gordon theory. This quantum probability current leads directly to positive definite quantum probabilities. Because these negative probabilities are in the bare Klein-Gordon theory, intrinsically a result of negative energies, the fact that we-here arrive at a theory with positive probabilities, means that negative energy particles are not to be considered problematic as is the case in the bare Klein-Gordon theory. From an abstract-objective stand-point; in comparison with positive energy particles, the corollary is that negative energy particles should have equal chances to exist. As to why these negative energy particles do not exist, this is analogous to asking why is it that Dirac’s antimatter does not exist in equal proportions with matter. This problem of why negative energy particles do not exist in equal proportions with positive energy particles is a problem that needs to be solved by a future theory.
Azimuthally SymmetricTheory of Gravitation (I) On the Perihelion Precession of Planetary Orbits
(arXiv, 2009-12-15) Nyambuya, G. G.
From a purely none-general relativistic standpoint,we solve the empty space Poisson equation(∇2Φ=0) for an azimuthally symmetric setting, i.e., for a spinning gravitational system like the Sun. We seek the general solution of the formΦ = Φ(r,θ). This general solution is constrained such that in the zeroth order approximation it reduces to Newton’swell known inverse square law of gravitation. For this general solution, it is seen that it has implications on the orbits of test bodies in the gravitational ﬁeld of this spinning body. We show that to second order approximation,this azimuthally symmetric gravitational ﬁeld is capable of explaining at least two things (1) the observed perihelion shift of solar planets (2) that the mean Earth-Sun distance must be increasing–this resonates with the observations of two independent groups of astronomers(Krasinsky&Brumberg 2004; Standish 2005) who have measured that the mean Earth-Sun distance must be increasing at a rate of about7.0±0.2m/cy (Standish 2005) to 15.0±0.3m/cy (Krasinsky&Brumberg 2004).In-principle,we are able to explain this result as a consequence of loss of orbit alangular momentum–this loss of orbit alangular momentum is a direct prediction of the theory.Further,we show that the theory is able to explain at a satisfactory level the observed secular increase Earth Year (1.70±0.05ms/yr; Miuraet al. 2009). Furthermore, we show that the theory makes a signiﬁcant and testable prediction to the effect that the period of the solar spin must be decreasing at a rate of at least8.00±2.00s/cy.
Bipolar Outﬂows as a Repulsive Gravitational Phenomenon –Azimuthally SymmetricTheory of Gravitation (II)
(arXiv, 2010-10-18) Nyambuya, G. G.
This reading is part in a series on the Azimuthally Symmetric Theory of Gravitation (ASTG) set-out in Nyambuya (2010a). This theory is built on Laplace- Poisson’s well known equation and it has been shown therein (Nyambuya 2010a) that the ASTG is capable of explaining – from a purely classical physics standpoint; the precession of the perihelion of solar planets as being a consequence of the azimuthal symmetry emerging from the spin of the Sun. This symmetry has and must have an influence on the emergent gravitational field. We show herein that the emergent equations from the ASTG – under some critical conditions determined by the spin – do possess repulsive gravitational fields in the polar regions of the gravitating body in question. This places the ASTG on an interesting pedal to infer the origins of outflows as a repulsive gravitational phenomena. Outflows are an ubiquitous phenomena found in star forming systems and their true origins is a question yet to be settled. Given the current thinking on their origins, the direction that the present reading takes is nothing short of an asymptotic break from conventional wisdom; at the very least, it is a complete paradigm shift as gravitation is not at all associated; let alone considered to have anything to do with the out-pour of matter but is thought to be an all-attractive force that tries only to squash matter together into a single point. Additionally, we show that the emergent Azimuthally Symmetric Gravitational Field from the ASTG strongly suggests a solution to the supposed Radiation Problem that is thought to be faced by massive stars in their process of formation. That is, at 8 - 10M , radiation from the nascent star is expected to halt the accretion of matter onto the nascent star. We show that in-falling material will fall onto the equatorial disk and from there, this material will be channelled onto the forming star via the equatorial plane thus accretion of mass continues well past the curtain value of 8-10M albeit via the disk. Along the equatorial plane, the net force (with the radiation force included) on any material there-on right up-till the surface of the star, is directed toward the forming star, hence accretion of mass by the nascent star is un-hampered.
Case of the Symmetrically Accelerated Twins
(QuantumDream, Inc., 2014-11) Nyambuya, G. G.
This is the second instalment in a four part series, the aim of the work being to introduce absolute motion into Einstein’s Special Theory of Relativity (STR). Herein, we depart from the traditional case where one twin stays put while the other rockets into space, we consider the case of identically accelerated twins. Both twins depart at uniform relativistic speeds in opposite directions for a round trip from the Earth on their 21th birthday destined into space to some distant constellation that is a distance L0 in the rest frame of the Earth. A proper application of Einstein’s STR tells us that the Earth bound observers will conclude that on the day of reunion, both twins must both have aged the same albeit their clocks (which where initially synchronized with that of the Earth bound observers) will have registered a duration less than that registered by the Earth bound observers. In the traditional twin paradox, it is argued that the stay at home twin will have aged more than the travelling twin and the asymmetry is attributed to the fact that the travelling twin’s frame of reference is not an inertial reference frame during the periods of acceleration and deceleration making it “illegal” for the travelling twin to use the STR in their frame, thus “resolving” the paradox. This same argument does not hold in the case considered here as both twins will undergo identical experiences where each twin sees the other as the one that is in motion. This means, each twin must conclude that the other twin is the one that is younger. They will conclude that their ages must be numerically different, thus disagreeing with the Earth bound observers that their ages are the same. This leads us to a true paradox that throws Einstein’s Philosophy of Relativity into complete disarray.
A comparison of crystalline basement aquifers and Kalahari aquifers in exploration of groundwater occurrence in Zimbabwe
(2016-07) Chuma, Constant; Hlatywayo, Dumisani J.; Midzi, Vunganai; Gumbo, Mervyn; Muchingami, Innocent; Mashingaidze, Robin T
Exploration of groundwater occurrence becomes complex if there is inadequate information to explain the its dynamics. The paper compares the major aquifers found in Zimbabwe in order to maximise the exploration of groundwater in the semi-arid regions. Geophysical and geospatial tools have proved to be useful tools in divining for groundwater in different geological settings. Crystalline basement aquifers are characterised by impervious rock which confines water in the upper layers whilst Kalahari sands provide high yielding unconsolidated aquifers. Transmissivity and conductivity decreases with depth in crystalline whilst the reverse is true for Kalahari sands.
A comparison of dosimetric properties of three solid state dosimetry systems for dosimetry audit in radiotherapy.
(International Atomic Energy Agency (IAEA), 2014-12) Azangwe, Godfrey
The purpose of this study is to investigate and compare characteristics of three solid state dosimetry systems in order to determine working parameters and corrections needed for remote dosimetry audits of high energy photon and electron beams. The following systems were investigated: a thermo luminescent dosimetry (TLD) system (TLD-100, PCL3 reader), an optically stimulated luminescent dosimetry (OSLD) system (nanoDots, microStar reader) and a radiophoto luminescent dosimetry (RPLD) system (GD 302M, FGD-1000 reader).
Detector to detector corrections: A comprehensive experimental study of detector specific correction factors for beam output measurements for small radiotherapy beams.
(Medical Physics, 2014-07) Azangwe, Godfrey
Purpose: The aim of the present study is to provide a comprehensive set of detector specific correction factors for beam output measurements for small beams, for a wide range of real time and passive detectors. The detector specific correction factors determined in this study may be potentially useful as a reference data set for small beam dosimetry measurements. Methods: Dose response of passive and real time detectors was investigated for small field sizes shaped with a micromultileaf collimator ranging from 0.6 × 0.6 cm2 to 4.2 × 4.2 cm2 and the measurements were extended to larger fields of up to 10 × 10 cm2. Measurements were performed at 5 cm depth, in a 6 MV photon beam. Detectors used included alanine, thermoluminescent dosimeters (TLDs), stereotactic diode, electron diode, photon diode, radiophotoluminescent dosimeters (RPLDs), radioluminescence detector based on carbon-doped aluminium oxide (Al2O3:C), organic plastic scintillators, diamond detectors, liquid filled ion chamber, and a range of small volume air filled ionization chambers (volumes ranging from 0.002 cm3 to 0.3 cm3). All detector measurements were corrected for volume averaging effect and compared with dose ratios determined from alanine to derive a detector correction factors that account for beam perturbation related to nonwater equivalence of the detector materials. Results: For the detectors used in this study, volume averaging corrections ranged from unity for the smallest detectors such as the diodes, 1.148 for the 0.14 cm3 air filled ionization chamber and were as high as 1.924 for the 0.3 cm3 ionization chamber. After applying volume averaging corrections, the detector readings were consistent among themselves and with alanine measurements for several small detectors but they differed for larger detectors, in particular for some small ionization chambers with volumes larger than 0.1 cm3.
Dielectric barrier discharge CO2 TEA laser operated at frequencies up to 400 Hz
(SA Institute of Physics, 2011) Baricholo, Peter; Stehmann, Timo; Rohwer, Erich G.; Collier, M.; Hlatywayo, Dumisani J.; Von Bergmann, Hubertus M.
A dielectric barrier discharge CO2 TEA laser excited by a thyratron driven power supply has been developed and characterized. Laser output was observed at frequencies up to 25 Hz for an electrode separation of 10 mm with 1.8 mm suprasil glass covering the electrodes. At this gap separation, pulsed power output of about 9 W was detected for gas pressures between 100 and 400 mbar. The laser has a pulse duration was about 0.3 flS with a risetime of ~100 ns. Changing the electrode separation to 5 mm and using 1.4 mm suprasil glass dielectric increased the output power to 23 Wand enabled laser output to be observed at gas pressures up to 700 mbar and maximum pulse excitation frequencies of up to 400 Hz. The developed laser does not require water cooling since the system operates in burst pulse mode.
Dirac Equation for General Spin Particles Including Bosons
(National University of Science & Technology, 2009) Nyambuya, G. G.
We demonstrate (show) that the Dirac equation – which is universally assumed to represent only spin 1/2 particles; can be ma- nipulated using legal mathematical operations – starting from the Dirac equation – so that it describes any general spin particle. If our approach is acceptable and is what Nature employs, then, as currently obtaining, one will not need a unique and separate equation to describe particles of different spins, but only one equation is what is needed – the Gen- eral Spin Dirac Equation. This approach is more economic and very much in the spirit of unification – i.e., the tie-ing together into a single unified garment – a number of phenomenon (or facets of physical and natural reality) using a single principle, which, in the present case is the bunching together into one theory (equation), all spin particles into the General Spin Dirac Equation.
Dirac equation for the proton (I) -- Why three quarks for muster mark?
(2016-03) Nyambuya, G. G.
The present reading is the first in a series where we suggest a Dirac equation for the Proton. Despite its great success in explaining the physical world as we know it, in its bare form, not only is the Dirac equation at loss but fails to account e.g. for the following: (1)Why inside hadrons (Proton in this case) there are three, not four or five quarks; (2) Why quarks have fractional electronic charges; (3) Why the gyromagnetic ratio of the Proton is not equal to two as the Dirac equation requires. In the present reading, we make an attempt to answer the first question of why inside the proton, there are three, not four or five quarks.
Dirac equation for the proton (II) -- Why fractional charges for Muster Mark's Quarks?
(2016-03) Nyambuya, G. G.
The present reading is the second in a series where we suggest a Dirac equation for the Proton. Despite its great success in explaining the physical world as we know it, in its bare form, not only is the Dirac equation at loss but fails to account e.g. for the following: (1) Why inside hadrons there are three, not four or five quarks; (2)Why quarks have fractional charges; (3) Why the gyromagnetic ratio of the Proton is not equal to two as the Dirac equation requires. In the present reading, we make an attempt to answer the second question of why quarks have fractional charges. We actually calculate the exact values of the charges of these quarks.
Dirac Wavefunction as a 4 × 4 Component Function.
(2016-04) Nyambuya, G. G.
Since it was discovered some 84 years ago, the Dirac equation is understood to admit 4 × 1 com- ponent wavefunctions. We demonstrate here that this same equation does admit 4 × 4 component wavefunctions as-well.
Effect of land use on water quality and phytoplankton community in the tropical Khami River in semi-arid southwest Zimbabwe
(NISC, 2017-01) Dzinomwa, T; Ndagurwa, Hilton G.T.
The water quality and phytoplankton community assemblage of the Khami River, a tropical river sub catchment in semi-arid southwest Zimbabwe impacted by agriculture and urban land use, were examined in March 2015. Conductivity, sulphates, total dissolved solids and salinity were higher at urban sampling points than at agricultural sampling points. In contrast, agricultural sampling points were more turbid, and had a greater content of nitrates than urban sampling points. The phytoplankton community was dominated by Cyanobacteria, mainly Microcystis aeruginosa, with densities of up to 20 times higher at urban than at agricultural sampling points. There was an increasing dominance of Cyanobacteria (M. aerugionosa and Merismopedia glauca) and Chlorophyta (Eudorina elegans, Spirogyra sp. and Pediastrum duplex) and a decreasing importance of Bacillariophyta along the agriculture-to-urban gradient. Given the increasing scarcity of water in southern Africa, not only do our findings confirm the importance of land use types as drivers of water quality and phytoplankton community composition and structure. However, they also show that Cyanobacteria, Chlorophyta and Bacillariophyta can be indicators of changes in water quality, factors that will prove pertinent to management for effective water quality management using phytoplankton composition as bioindicators.
Effect of the Darkforce on the Extra-Anomalous Apsidal Precession of Solar Planets
(2018-05) Nyambuya, G. G.
We demonstrate that, while the proposed Gravitational Dark-force Theory (of Nyambuya 2018a, hereafter Paper I) predicts an extra-anomalous apsidal precession for Solar planets due to the gravitational dark-force on the orbits of these planets, the predicted extra-anomalous apsidal precession is so small — so much that — it can not account for the observed extra-anomalous apsidal precession of Solar planets. This null result is important in that it informs us that whatever may be the cause of the extraanomalous apsidal precession, it is not the proposed gravitational dark-force.
Equivalent dirac equation in 24 irreducible representations with symmetry violations Including CPT-Symmetry violation.
(2015-10) Nyambuya, G. G.
We demonstrate that if one adheres to a method akin to Dirac’s method of arriving at the Dirac equation – then, the Dirac equation is not the only equation that one can generate but that there is a whole new twenty four equations that Dirac left out. Off these new equations – interesting is that; some of them violate C, P, T, CT, CP, PT and CPT-Symmetry. If these equations are acceptable on the basis of them flowing from the widely – if not universally accepted Dirac prescription, then, the great riddle of why the preponderance of matter over antimatter might find a solution.

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