IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
Electromagnetic fields of time-dependent magnetic monopoleIOSR Journals
Dirac-Maxwell’s equations, retained for magnetic monopoles, are generalized by introducing
magnetic scale field. It allows the magnetic monopoles to be time-dependent and the potentials to be Lorentz
gauge free. The non-conserved part or the time-dependent part of the magnetic charge density is responsible to
produce the magnetic scalar field which further contributes to the magnetic and electric vector fields. This
contribution makes possible to create an ideal square wave magnetic field from an exponentially rising and
decaying magnetic charge.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
Electromagnetic fields of time-dependent magnetic monopoleIOSR Journals
Dirac-Maxwell’s equations, retained for magnetic monopoles, are generalized by introducing
magnetic scale field. It allows the magnetic monopoles to be time-dependent and the potentials to be Lorentz
gauge free. The non-conserved part or the time-dependent part of the magnetic charge density is responsible to
produce the magnetic scalar field which further contributes to the magnetic and electric vector fields. This
contribution makes possible to create an ideal square wave magnetic field from an exponentially rising and
decaying magnetic charge.
Comparison of Different Absorbing Boundary Conditions for GPR Simulation by t...IJMER
This paper compares three boundary conditions, i.e. transmitting boundary condition, Sarma
absorbing boundary condition and the uniaxial complete matched layerabsorbing boundary condition for
simulation of ground penetrating radar (GPR) by the time domain finite element (FEM) method. The
formulations of the three boundary conditions for the FEM method are described. Their effectiveness in
absorbing the incident electromagnetic waves are evaluated by the reflection coefficient on the boundary
of a simple GPR model.The results demonstrate that UPML boundary condition can yield a reflection
coefficient smaller than -50 dB, which is -20 dB smaller than other two boundary conditions.
Talk given at the workshop "Multiphase turbulent flows in the atmosphere and ocean", National Centre for Atmospheric REsearch, Boulder CO, August 15 2012
Localized Electrons with Wien2k
LDA+U, EECE, MLWF, DMFT
Elias Assmann
Vienna University of Technology, Institute for Solid State Physics
WIEN2013@PSU, Aug 14
Space Vector Pulse –Width Modulation for a Balanced Two Phase Induction Motor...IDES Editor
This paper deals with the mechanism of space –
vector pulse –width modulation (SVPWM) for a balanced two
–phase induction motor ,in detail .It explains how the waveforms
of the voltages applied to the two phases derive from the
SVPWM .
Comparison of Different Absorbing Boundary Conditions for GPR Simulation by t...IJMER
This paper compares three boundary conditions, i.e. transmitting boundary condition, Sarma
absorbing boundary condition and the uniaxial complete matched layerabsorbing boundary condition for
simulation of ground penetrating radar (GPR) by the time domain finite element (FEM) method. The
formulations of the three boundary conditions for the FEM method are described. Their effectiveness in
absorbing the incident electromagnetic waves are evaluated by the reflection coefficient on the boundary
of a simple GPR model.The results demonstrate that UPML boundary condition can yield a reflection
coefficient smaller than -50 dB, which is -20 dB smaller than other two boundary conditions.
Talk given at the workshop "Multiphase turbulent flows in the atmosphere and ocean", National Centre for Atmospheric REsearch, Boulder CO, August 15 2012
Localized Electrons with Wien2k
LDA+U, EECE, MLWF, DMFT
Elias Assmann
Vienna University of Technology, Institute for Solid State Physics
WIEN2013@PSU, Aug 14
Space Vector Pulse –Width Modulation for a Balanced Two Phase Induction Motor...IDES Editor
This paper deals with the mechanism of space –
vector pulse –width modulation (SVPWM) for a balanced two
–phase induction motor ,in detail .It explains how the waveforms
of the voltages applied to the two phases derive from the
SVPWM .
Introducing the lesser-known features of Drupal 7, the upcoming version of Drupal: Queues, Caches, Rendering cache, Document-oriented storage, File streaming, Intelligent session handling.
Vladimir S. Aslanov, Alexander S. Ledkov, Arun K. Misra, Anna D. Guerman
The 63rd International Astronautical Congress
The purposes this research are
+ development of the mathematical model for a space elevator taking into account the influence of the atmosphere;
+ study of dynamics of elevator's elements when its ribbon is cut;
+ analysis of the consequences of the rupture of the space elevator ribbon for satellites and objects on the ground.
Analytic Model of Wind Disturbance Torque on Servo Tracking AntennaIJMER
International Journal of Modern Engineering Research (IJMER) is Peer reviewed, online Journal. It serves as an international archival forum of scholarly research related to engineering and science education.
Periodic material-based vibration isolation for satellitesIJERA Editor
The vibration environment of a satellite is very severe during launch. Isolating the satellitevibrations during
launch will significantly enhance reliability and lifespan, and reduce the weight of satellite structure and
manufacturing cost. Guided by the recent advances in solid-state physics research, a new type of satellite
vibration isolator is proposed by usingperiodic material that is hence called periodic isolator. The periodic
isolator possesses a unique dynamic property, i.e., frequency band gaps. External vibrations with frequencies
falling in the frequency band gaps of the periodic isolator are to be isolated. Using the elastodynamics and the
Bloch-Floquet theorem, the frequency band gaps of periodic isolators are determined. A parametric study is
conducted to provide guidelines for the design of periodic isolators. Based on these analytical results, a finite
element model of a micro-satellite with a set of designed periodic isolators is built to show the feasibility of
vibration isolation. The periodic isolator is found to be a multi-directional isolator that provides vibration
isolation in the three directions.
Periodic material-based vibration isolation for satellitesIJERA Editor
The vibration environment of a satellite is very severe during launch. Isolating the satellitevibrations during
launch will significantly enhance reliability and lifespan, and reduce the weight of satellite structure and
manufacturing cost. Guided by the recent advances in solid-state physics research, a new type of satellite
vibration isolator is proposed by usingperiodic material that is hence called periodic isolator. The periodic
isolator possesses a unique dynamic property, i.e., frequency band gaps. External vibrations with frequencies
falling in the frequency band gaps of the periodic isolator are to be isolated. Using the elastodynamics and the
Bloch-Floquet theorem, the frequency band gaps of periodic isolators are determined. A parametric study is
conducted to provide guidelines for the design of periodic isolators. Based on these analytical results, a finite
element model of a micro-satellite with a set of designed periodic isolators is built to show the feasibility of
vibration isolation. The periodic isolator is found to be a multi-directional isolator that provides vibration
isolation in the three directions.
Numerical Simulation and Prediction for Steep Water Gravity Waves of Arbitrar...CSCJournals
Nonlinear permanent progressive wave is one of the most important applications in water waves. In this study, analytic formulation of the steep water gravity waves is presented. Abohadima and Isobe [1] showed that Cokelet solution [2] is the most accurate among many other solutions. Due to the nonlinearity of analytic equations, the need to numeric simulation is raised up. In the current paper, consequence numerical models, using one of the artificial intelligence techniques, are designed to simulate and then predict the non linear properties of permanent steep water waves. Artificial Neural Network (ANN), one of the artificial intelligence techniques, is introduced in the current paper to simulate and predict the wave celerity, momentum, energy and other wave integral properties for any permanent waves in water of arbitrary uniform depth. The ANN results presented in the current study showed that ANN technique, with less effort, is very efficiently capable of simulating and predicting the non linear properties of permanent steep water waves.
Some Research Notes on developing a Hybrid UAV for space industrialization. Goal is to develop profitable routes, infrastructure and vehicles to harvest power from Venus, Mercury and Sun and transmit power to interests
P-Wave Onset Point Detection for Seismic Signal Using Bhattacharyya DistanceCSCJournals
In seismology Primary p-wave arrival identification is a fundamental problem for the geologist worldwide. Several numbers of algorithms that deal with p-wave onset detection and identification have already been proposed. Accurate p- wave picking is required for earthquake early warning system and determination of epicenter location etc. In this paper we have proposed a novel algorithm for p-wave detection using Bhattacharyya distance for seismic signals. In our study we have taken 50 numbers of real seismic signals (generated by earthquake) recorded by K-NET (Kyoshin network), Japan. Our results show maximum standard deviation of 1.76 sample from true picks which gives better accuracy with respect to ratio test method.
Macroeconomics- Movie Location
This will be used as part of your Personal Professional Portfolio once graded.
Objective:
Prepare a presentation or a paper using research, basic comparative analysis, data organization and application of economic information. You will make an informed assessment of an economic climate outside of the United States to accomplish an entertainment industry objective.
The simplified electron and muon model, Oscillating Spacetime: The Foundation...RitikBhardwaj56
Discover the Simplified Electron and Muon Model: A New Wave-Based Approach to Understanding Particles delves into a groundbreaking theory that presents electrons and muons as rotating soliton waves within oscillating spacetime. Geared towards students, researchers, and science buffs, this book breaks down complex ideas into simple explanations. It covers topics such as electron waves, temporal dynamics, and the implications of this model on particle physics. With clear illustrations and easy-to-follow explanations, readers will gain a new outlook on the universe's fundamental nature.
Introduction to AI for Nonprofits with Tapp NetworkTechSoup
Dive into the world of AI! Experts Jon Hill and Tareq Monaur will guide you through AI's role in enhancing nonprofit websites and basic marketing strategies, making it easy to understand and apply.
Unit 8 - Information and Communication Technology (Paper I).pdfThiyagu K
This slides describes the basic concepts of ICT, basics of Email, Emerging Technology and Digital Initiatives in Education. This presentations aligns with the UGC Paper I syllabus.
This slide is special for master students (MIBS & MIFB) in UUM. Also useful for readers who are interested in the topic of contemporary Islamic banking.
Executive Directors Chat Leveraging AI for Diversity, Equity, and InclusionTechSoup
Let’s explore the intersection of technology and equity in the final session of our DEI series. Discover how AI tools, like ChatGPT, can be used to support and enhance your nonprofit's DEI initiatives. Participants will gain insights into practical AI applications and get tips for leveraging technology to advance their DEI goals.
Thinking of getting a dog? Be aware that breeds like Pit Bulls, Rottweilers, and German Shepherds can be loyal and dangerous. Proper training and socialization are crucial to preventing aggressive behaviors. Ensure safety by understanding their needs and always supervising interactions. Stay safe, and enjoy your furry friends!
Normal Labour/ Stages of Labour/ Mechanism of LabourWasim Ak
Normal labor is also termed spontaneous labor, defined as the natural physiological process through which the fetus, placenta, and membranes are expelled from the uterus through the birth canal at term (37 to 42 weeks
2. P. A. Karkantzakos / Journal of Engineering Science and Technology Review 2(1) (2009) 76-81
Let χ (t), ψ (t) be the coordinates of the projectile as func- (10)
tions of time.
From the second equation of Eqs.9, with the help of Lemma 3.1,
The initial conditions may be stated as we find
(1)
(11)
where , .
The projectile moves under the influence of the gravitational Briefly we have
force
(2) (12)
and the retarding force
Lemma 3.2 enables us to show
(3)
(13)
From Newton’s Second Law the equations of motion are
and then to derive that Τ(σ) is a continuous and strictly monotonic
(4)
decreasing function over its domain of definition and that its range
is the interval (α,2α].
(5)
In Fig.2 we have chosen (1+σα) as independent variable
The solutions of the above Linear Differential Equations are and Τ (σ) / α as dependent in order to show the properties of the
curve without assigning any value to parameter α.
(6)
and
(7)
We intend to write time of flight as a function of σ; let
be the corresponding function. The time of flight
may be found by noticing that ψ=0 at the end of
the trajectory, hence
(8)
By combining Eq.7 and Eq.8 we find
Figure 2. The variation of Τ (σ) / α with (1+σα)
(9) Ιn &2.2 we shall seek a way in order to comprehend deeper
the limiting behaviour of the curve in Fig.2.
2.2 For , let us express the time of fall of the pro-
where jectile as a function of σ and let us prove that it is greater than
the time of rise with the exception of the case of zero constant of
resistance where we have equality.
77
3. P. A. Karkantzakos / Journal of Engineering Science and Technology Review 2(1) (2009) 76-81
Solution inequality
We intend to write time of rise as a function of σ; let
be the corresponding function. (22)
By solving Eq.5 for we find
The proof of inequality (19) is now complete.
(14) Finally the variation of Τf (σ) / α with (1+σα) is shown in
Fig.3 and Fig.4.
The time of rise may be found by noticing that
at the highest point of the trajectory, hence
(15)
By solving the last equation for Τr we find
(16)
From Eq.16, we may derive that Τr (σ) is a continuous and
strictly monotonic decreasing function over its domain of defini-
tion and that its range is the interval
Figure 3. The variation of Τf (σ) / α with (1+σα)
We intend to obtain the time of fall as a function of σ; let
be the corresponding function. Then we have
(17)
By combining the last equation with Eq.12 and Eq.16 we
find
(18)
Let us now try to prove the inequality
(19)
By combining Eq.16 and Eq.18 we find
Figure 4. The variation of Τf (σ) / α with (1+σα)
(20)
We notice from Fig.3 and Fig.4 that, as (1+σα) increases,
(21) the function Τf (σ) / α initially decreases reaching the absolute
minimum (absolute - min (Τf (σ) / α) → 0.838274 when
where, for the determination of the sign of the logarithm in Eq.21 (1+σα) → 5.54791) and then increases approaching the limit-
we use Lemma 3.3 by putting χ = b-1 (1+ασ) and proving the ing value 1.
78
4. P. A. Karkantzakos / Journal of Engineering Science and Technology Review 2(1) (2009) 76-81
For a deeper comprehending of the limiting behaviour of the lowing relation holds
curve in Fig.4 we will try to develop an approximate treatment of
(29)
the fall of the projectile, in the vertical sense, for σ ? α -1.
By putting in Eq.6 t = Τ (σ) and expressing Τ (σ) through
From Eq.13 and Lemma 3.2 we find
Eq.12 we find
(23)
(30)
From Eq.16 we obtain
-1
(24) We notice that, for the function b of Lemma 3.1, it holds,
Then,
(25)
(31)
By combining Eq.7 and Eq.16 we obtain
By combining Eq.30 and Eq.31 we find, for the range,
(26) 2υ0 χ a, σ=0
(32)
R( σ ) = b −1 (1 + σa )
-υ0 χ σ −1 , σ ∈ (0,+∞ ),
where stands for the maximum 1 + σa
height reached by the projectile.
From Εqs.(24), (25), (26) we finally get which yields the relation we seek, in its simplest form.
By combining Eq.12 with Eq.32 we find the important relation,
(27)
(33)
where
(28) From Eq.33, we may derive that R (σ) is a continuous and
strictly monotonic decreasing function over its domain of defini-
stands for the magnitude of the terminal velocity of the projectile tion and that its range is the interval
[1].
Eq.27 permits us to approximate the motion of the projectile Finally the variation of R (σ) / αυοχ with (1+σα), for
during its fall for σ ? α -1, in the vertical sense, as uniform with , is shown in Fig.5.
speed equal to uter and may be comprehended as follows.
During projectile’s fall, because of the large value of σ
compared to α -1, the vertical component of the retarding force
becomes so big that it almost cancels the force of gravity in a
negligible amount of time in comparison with the time of fall;
consequently the projectile approaches its terminal velocity ap-
proximately from the highest point of its trajectory.
The above approximate treatment of the fall of the projectile
also helps us to comprehend in a deeper way the limiting behav-
iour of the curve in Fig.2, since Tr (σ ? α -1) is negligible com-
pared to Tf (σ ? α -1).
2.3 For , let us express the range of the projectile as
a function of σ.
Solution
Let be the corresponding function, then the fol- Figure 5. The variation of R (σ) / αυοχ with (1+σα), for
79
5. P. A. Karkantzakos / Journal of Engineering Science and Technology Review 2(1) (2009) 76-81
For the limiting behaviour of the curve in Fig.5, by combin- 2.4 For , let us express the constant of resistance per
ing Eq.23 and Eq.33, we obtain the approximate expression unit mass of the projectile as a function of the time of flight and
range of the motion.
(34)
Solution
From Eq.33, by solving for σ we find
Finally, we shall try to develop an approximate treatment of
the trajectory of the projectile, for σ ? α -1.
(39)
Let be the displacement of the
projectile, along the horizontal axis, during its rise. By combining
Eq.6 and Eq.16 we get Obviously Eq.39 gives the relation we seek.
3. Appendix
(35)
3.1 Lemma
The inverse function for
Let be the displacement of
the projectile, along the horizontal axis, during its fall. By com-
bining Eq.33 and Eq.35 we obtain (40)
Is
(36)
(41)
Finally from Eq.23 and Eq.36 we get (For the proof of Lemma 3.1 see Ref.[2].)
(37) 3.2 Lemma
The function
The above approximate relationship permits us to consider
that for σ ? α -1 the trajectory of the projectile during its fall ap- (42)
proximates closely to the vertical line that passes from the highest
point reached by it.
By combining both results concerning the fall, the one above
and the one in &2.2, we conclude that the motion of the projectile (where b-1(ω) is the function whose definition has been given in
during its fall, for σ ? α -1, can be regarded with good approxi- Lemma 3.1),
mation, as uniform along the vertical line which passes from the is a continuous and strictly monotonic decreasing function over its
highest point reached by it, with speed equal to its terminal veloc- domain of definition and its range is the interval (1,2].
ity.
From Eqs.(10), (24), (26), (35) we obtain
Proof
By using elementary calculus we may derive that h (ω) is a con-
(38) tinuous function on its domain of definition. In order to determine
the sign of the first derivative of h (ω) we consider the composite
function
The above relationship permits us to consider that the trajec-
(43)
tory of the projectile during its rise, for σ ? α -1, approximates
closely to the line along witch it was launched.
80
6. P. A. Karkantzakos / Journal of Engineering Science and Technology Review 2(1) (2009) 76-81
(where b ( χ ) is the function whose definition has been given in 3.3 Lemma
Lemma 3.1) and then calculate its first derivative For the function b ( χ ) of Lemma 3.1 it holds
(44) (48)
For the first derivative of b ( χ ) it holds
Proof
We notice
(45)
(49)
For the first derivative of the composite function
it holds where the last inequality can be easily proved by using elementary
calculus.
(46)
4. Conclusions
In this paper we examined the motion of a projectile in a constant
By combining the last equation with Eq.44 and Eq.45 we
gravitational field under the influence of a retarding force propor-
find tional to the velocity and developed an exact method to express
time of flight, time of fall and range of the projectile, as functions
(47) of the constant of resistance per unit mass of the projectile for
all its possible values. Then we expressed the constant of resist-
ance per unit mass of the projectile as a function of the time of
Hence h (ω) is a continuous and strictly monotonic decreas- flight and range of the motion. Mathematically the above method
ing function over its domain of definition and its range is the inter- is based on the inversion of the function
val
References
1. Jerry B. Marion, Classical Dynamics of particles and systems, Academic 2. Panagiotis A. Karkantzakos, “When the inverse function is not simple”,
Press New York and London, p.64-73, (1965). Records of 24 Conference of Hellenic Mathematical Society, p.135-140,
(2007).
81