Latest Articles
Original Research Article
ABSTRACT
The effects of the inlet gas oil temperature and catalyst-to-oil weight ratio on the catalytic cracking behaviors and the distribution of the product and the yield of the riser outlet main products as unconverted gas oil, gasoline, and coke were investigated on a real industrial FCC Riser reactor with a model LRC-99 catalyst and atmospheric residue derived from Niger’s crude oil of Agadem bloc was used as the feedstock. A four-lumped kinetic mathematical model is developed to predict the feedstock conversion and the product distribution by using the deactivation function coke-on- catalyst approach. The model was validated with a good agreement against real industrial fluidized bed riser reactor plant data from Niger and industrial riser data from literature sources. The results show that the inlet gas oil temperature and catalyst-to-oil weight ratio obviously affect the cracking reactions behavior and govern the reaction rates.
ABSTRACT
Pólya thinks the major goal of teaching is to teach students how to ponder. It means that we need not only to give them the knowledge but also to help them improve their ability of using the knowledge and to help them form a good habit of thinking and a good mental state. He also thinks that what the teacher says in class is very important and what is more important is to learn what the students are thinking about. From this standpoint, he presents the three Learning Principles, which is also known as 3 Teaching Principles. These principles are quite practical and are worth practicing and improving in teaching. This article introduces how to use the principles, taking Interpolation Method for example.
ABSTRACT
The Lorentz transformation (LT) makes three predictions which are not consistent with one another: Lorentz-FitzGerald length contraction (FLC), time dilation (TD) and light-speed equality for observers in relative motion to one another. The LT also stands in violation of the Law of Causality because it fails to recognize that inertial clocks can never change their rate spontaneously. Einstein’s light-speed postulate (LSP) is shown to be unviable by considering a case in which a light source passes by a stationary observer at the same time that it emits a light pulse in the same direction. It is found that, in contradiction to the LSP, that the classical velocity (Galilean) transformation (GVT) is applicable when two observers in relative motion deduce the speed of a light wave. The Newton-Voigt transformation (NVT) is consistent with the Law of Causality because it assumes space and time do not mix. The NVT is nonetheless consistent with the relativistic velocity transformation (RVT) and also with Einstein’s mass-energy equivalence relation E=mc2. The ratio Q of clock rates for two inertial rest frames S and S’ is required input for the NVT. Experimental data obey the Universal Time-dilation Law (UTDL) which states that the measured time Δt obtained by a inertial clock for a given event is inversely proportional to γ(v)= (1-v2c-2)-0.5v, where v is the speed of the clock relative to a specific rest frame referred to as the objective rest frame ORS. The value of Q when the clock of the observer in at rest in S while that of another observer is at rest in the object’s rest frame S’ is obtained from the UTDL as the ratio γ(v’)/γ(v). The Uniform Scaling method considers Q to be a conversion factor between the units of time in the two rest frames. It is found that the conversion factors for all other physical properties are integral multiples of Q. Kinetic scaling of the properties insures that the laws of physics are the same in each inertial frame, as required .........
ABSTRACT
The performance analysis of various empirical radio propagation models or harvesters used in wireless cellular networks is presented in this paper. In particular, second generation (2G) through fifth generation (5G) cellular networks route loss and cell coverage areas is researched. Planning any wireless communication system requires precise path loss and coverage area forecasting. The Hata model, the Stanford University Interim (SUI) model, and modified SUI models are contrasted in light of the urban terrain. The investigation is carried out at 28 GHz as inspiration for new wave (mm- wave) cellular systems, or for 5G communication. When -75 dBm is used as the desired minimum received power, it is shown that 2G communications (using the Hata model at 900 MHz) has the lowest route loss and thus the widest coverage area. Future mm-wave systems with the smallest coverage area are found to have the highest path loss (at 28 GHz using a modified SUI model).
Original Research Article
ABSTRACT
Assessment of pavement performance is essential in determining the serviceability and structural state of the pavement structure. Pavement failure and deterioration always commence immediately after the road has been opened to traffic. Several factors contributing to pavement failure and damage include traffic load, soil, environmental, economic, and stress distribution factor. Therefore, flexible pavement failure and deterioration are well-defined by alligator cracks, concentrated potholes, ruts, settlement, and localised depression. Pavement evaluation determines highway sections' functional and structural conditions for frequent monitoring or planning for maintenance. Kampi ya Moto-Eldama Ravine- Kamwasor (B77) road is a Kenya National Highways, Authority (KeNHA) class B road constructed in 2008. The length of the road is approximately 79.5 Km. However, the pavement had numerous distress features which developed even before the design life of the pavement was attained. The study, therefore, concentrated on evaluating the performance of the pavement to identify the type and level of severity of pavement distress; to establish a surface condition by measuring the level of roughness and rut depth and to perform a visual evaluation survey of the existing flexible pavement distresses; to identify the reason of structural and functional failures on Eldama Ravine-Kamwosor, and finally, to establish the residual structural strength of the existing flexible pavement and suggests the most viable maintenance intervention measures.
ABSTRACT
A well-known prediction of the Lorentz transformation (LT) of Einstein’s theory of Special Relativity (SR) is that when two observers exchange light signals, they will both measure a red shift (lowering in frequency). An experiment with gamma rays was reported by Hay et al., in 1960 in which an absorber is mounted at the rim of a high- speed centrifuge while the source is located near the rotor axis. There is general agreement that because of its acceleration, the clock attached to the absorber must be retarded relative to the gamma ray source. Despite the claim that this result is a confirmation of the Symmetry Principle, the fact remains that the slowing down of the absorber clock means that the frequency of the signals it receives from the source will be greater than the standard value, i.e. a blue shift will be observed because more waves are counted per second by virtue of the absorber clock’s reduced rate. This experience therefore stands in direct contradiction of the Symmetry Principle. In addition, it is pointed out that the three space-time predictions of the LT (equal speeds of light, time dilation and FitzGerald length contraction) are incompatible with one another. An alternate theory is presented (Uniform Scaling method) which is in full agreement with the results of the ultra-centrifuge experiment and also avoids any incompatibility with regard to it space-time predictions.
ABSTRACT
Einstein’s light speed postulate (LSP) is reviewed. It claims that the speed of light is independent of both the state of motion of the light source and that of the observer. An example is considered in which a light source is initially stationary in the rest frame of the observer. The light source then moves away with constant speed v relative to the observer. At the same time a light pulse is emitted in the same direction. According to the LSP, the speed of the light pulse is equal to c relative to both the stationary observer and the light source. It is shown that the LSP is unable to justify what happens after time T has elapsed, however, namely that the distance separating the light pulse from the observer is the same (cT) as it is for the light source. This is impossible since the observer and light source are no longer located at the same position in space. This procedure is referred to as “distance reframing.” It can also be used to prove that the above example is satisfactorily described by applying the Galilean velocity transformation (GVT). It leads to the conclusion that the speed of the light pulse relative to the stationary observer is c+v. i.e. greater than c, in direct contradiction to the longstanding claim of Einstein’s Special Relativity Theory (SR). One of the consequences of this development is that Einstein’s famous example of lightning strikes on a passing train is shown to be incorrectly interpreted as proving that the strikes do not occur simultaneously for a rider on the train and an observer on the station platform.