Physics Engineering

This book is intended as a textbook for the students of engineering physics and science. As an experienced teacher of physics/engineering physics. I have tried to select and arrange the material in such a way that the students would not face any difficulty in following the book. This edition, the second has been thoroughly revised. Errors and misprints have been corrected and some diagrams have been modified and improved for proper representation of the theory. To fulfil the requirements of students (on the basis of all India Survey), some more topics have been included in the second edition. New topics including conductivity of metal and semiconductor. Hall effect, magnetic materials, polarisation, zone plate, electro-optic effect, photoelasticity, etc. have been added.

A superluminal quantum-vortex model of the electron and the positron is produced from a superluminal double-helix model of the photon during electron-positron pair production. The two oppositely-charged (with Q = ±e sqrt (2/α) = 16.6e) open-helix spin-½ half-photons compose the double-helix photon. These half-photons separate and curl up their separated superluminal single-helical trajectories to form an electrically-charged superluminal closed-helix spin-½ quantum-vortex electron model and a corresponding positron model. The helical radius and the Dirac equation's zitterbewegung angular frequency of the quantum vortex electron and positron models equal the helical radius and zitterbewegung angular frequency of the two spin-½ half-photons, each of energy E = mc^2 , that composed the double-helix photon model of energy E = 2mc^2 from which the electron and positron models were produced. The photon and electron models are also compatible when a photon of energy E > 2mc^2 produces a relativistic electron-positron pair. Implications of the quantum vortex electron model for electron stability are discussed.

Pengaplikasian teknologi komputer yang semakin banyak di tahun-tahun mendatang akan menjadikan peran komputer semakin penting dan bisa jadi krusial. Dari urusan mengolah dokumen, menonton film, memainkan game hingga urusan cuci – mencuci. Berbicara mengenai komputer dan teknologi yang berhubungan dengannya kita tentu tak mungkin melepaskan diri dari salah satu ilmu pokok, yaitu pemrograman. Karena peran manusia yang belajar dan mendalami ilmu  semua yang Anda maupun penulis nikmati saat ini menjadi kenyataan, seperti: iPad, android, instagram, dan lain sebagainya. Saat ini, menyebut nama Strawberry atau Blueberry, mungkin yang terlintas dipikiran Anda adalah buah-buah segar untuk dimakan. Bagaimana jika penulis menyebutkan Blackberry? tanpa berpikir panjang Anda dengan yakin mengetahuinya sebagai salah satu smartphone yang terkenal dengan fasilitas BBM-nya. Walaupun sebenarnya Blackberry pun adalah salah satu buah yang namanya berakhiran berry. Di dunia ada lebih dari sepuluh buah – buahan yang namanya berakhiran berry.

Piping dan Instrumentasi Diagram atau sering dikenal dengan P&ID adalah "schematic", digunakan dalam bidang instrumentasi dan kontrol (Automation). P&ID yang digunakan oleh para teknisi lapangan, insinyur, dan operator bertujuan untuk dapat lebih memahami proses dan bagaimana instrumentasi yang saling terhubung dalam sebuah industri-industri.

An analytical study of elastoviscoplastic fluid flow in tubes of non-circular cross section is presented. The constitutive structure of the fluid is described by a linear frame invariant combination of the Phan-Thien −Tanner model of viscoelastic fluids and the Bingham model of plastic fluids. Non-circular tube cross sections are modeled by the shape factor method a one-to-one mapping of the circular base contour into a wide spectrum family of arbitrary tube contours. Field variables are expanded into asymptotic series in terms of the elasticity measure, the Weissenberg number We , coupled with an asymptotic expansion in terms of the geometrical mapping parameter ε leading to a set of hierarchical momentum balance equations which are solved successively up to and including the third order in We when the secondary field appears for the first time. The computational algorithm developed is applied to the study of the non-rectilinear flow in tubes with triangular and square cross sections. We find that the presence of the yield stress dampens the intensity of the purely viscoelastic vortices, the higher the yield stress the lower the intensity of the vortices in the cross-section, and the further away the vortices are from the center of the cross section as compared to the purely viscoelastic vortices. The results also evidence that viscoelasticity increases the axial flow for given viscoplastic conditions and pressure drop, and consequently increases the rate of flow, a phenomenon that may find applications in optimizing material transportation.

This paper reports the results of an experimental investigation to determine the climbing constants of viscoelastic liquids in the rotating rod geometry with two layers of viscoelastic liquids
and the results of an investigation which describes the effects of eccentricity on the free surface shape of a non-Newtonian liquid in motion between eccentric cylinders. The former set of results shows the rotating rod geometry with a layered medium of viscoelastic liquids may be used as a free surface viscometer yielding reliable and reproducible values for the sequentially determined climbing constants of those liquids. The latter set of results indicates that the concentric cylinder geometry is not
a good free surface viscometer. Very small eccentricities generate large circumferential pressure gradients which overwhelm small normal stress effects. There is good agreement between experimental and second order predictions for small eccentricities and rotational speeds and fluids which display large normal stress effects.

Undercooling is a natural extension in a levitation environment due to the elimination of container induced nucleation giving access to a metastable region of the phase diagram. It is important to solidification processes, and therefore, the knowledge of thermophysical properties in this region is crucial. The degree of undercooling determines the growth velocity, and is essential in selecting the metastable solid phase. The use of hydrogen gas reduces and removes heterogeneous nucleation catalysts (oxide and sulfide inclusions), and facilitates undercooling.

The steady free surface motion of a layered medium of viscoelastic fluids driven by a vertical rotating rod and the free surface motion of a viscoelastic fluid between vertical, eccentric, rotating cylinders is solved by means of domain perturbations. The flow field, the shape of the free surfaces and the interface and the climb at the rod are determined by expanding the stress in a series of Rivlin-Ericksen tensors and developing the theory as a perturbation of the rest state in powers of the angular frequency of the rod or of the cylinders. It is shown that rheometrical measurements in the rotating rod geometry are reliably reproducible whilst concentric cylinder geometry presents important practical problems in measuring rheological constants.

Türkiye Doğu Anadolu Bölgesi'nin ilk ve tek Fen Mühendislik ve Tasarım Dergisi / Turkey's first and only Science Engineering and Design Journal of the Eastern Anatolia Region.

Uluslararası Doğu Anadolu Fen Mühendislik ve Tasarım Dergisi'nin kapsamı, fen mühendislik ve tasarım ile ilgili tüm konulardaki orijinal araştırmalardan oluşur. Bilim ve teknolojinin çeşitli alanlarında orijinal araştırma sonuçları, bilimsel yorumlar ve kısa iletişim notları yayına kabul edilir. Dergi bilimsel ve hakemli bir dergi olup, Temmuz ve Aralık aylarında olmak üzere yılda 2 kez çevrimiçi ortamda yayımlanır. Derginin yayın dili Türkçe ve İngilizce'dir.

Makaleler en az iki hakem tarafından kör hakemlik uygulamasıyla değerlendirilmektedir.

https://dergipark.org.tr/ijeased (International Journal of Eastern Anatolia Science Engineering and Design) / International peer-reviewed free journal. We expect your shipments. ( Uluslararası Doğu Anadolu Fen Mühendislik ve Tasarım Dergisi / Uluslararası hakemli ücretsiz dergi. Gönderilerinizi bekleriz. )

Karakteristik pesawat aeromodeling merupakan suatu hal yang sangat penting dalam bidang ilmu aplikasi mekanika fluida, ditujukan untuk mendapatkan informasi dari suatu bentuk pesawat. Analisis pesawat aeromodeling ini dilakukan pada percobaan-percobaan. Dalam makalah ini, pesawat aeromodeling dilakukan dengan mengkaji aliran fluida di sepanjang kontur air foil sayap pesawat untuk mendapatkan distribusi kecepatan, tekanan, dan gaya-gaya yang terjadi di sekitar air foil.

We have investigated the effect of artificial grain boundaries on the electromagnetic properties of (1-x)La0.7Ca0.3MnO3 + xAl2O3 nanocomposites (x x= 0 x÷ 5wt%). Based upon a spin-polarized tunneling mechanism we have proposed a phenomenological model to explain the observed electrical transport behavior over the whole temperature range (70 ÷ 300K), especially the gradual drop of metal-insulator transition temperature (Tp) as a function of increasing Al2O3 content, while the feromagnetic-paramagnetic transition temperature (TC) remains almost constant (TC x= 250K). A large low-field magneto-resistance was observed for all the composite samples and the largest magnetoresistance ratio was recorded for a composition with x x=0.01.

Karakteristik pesawat aeromodeling merupakan suatu hal yang sangat penting dalam bidang ilmu aplikasi mekanika fluida, ditujukan untuk mendapatkan informasi dari suatu bentuk pesawat. Analisis pesawat aeromodeling ini dilakukan pada percobaan-percobaan. Dalam makalah ini, pesawat aeromodeling dilakukan dengan mengkaji aliran fluida di sepanjang kontur air foil sayap pesawat untuk mendapatkan distribusi kecepatan, tekanan, dan gaya-gaya yang terjadi di sekitar air foil.

Resonance-like phenomena in axisymmetric Poiseuille flows of viscoelastic fluids are studied. It is shown that instantaneous flow velocities of the upper convected Maxwell fluid with a spectrum of relaxation times drastically increase at certain frequencies of the oscillating pressure gradient. This effect becomes more pronounced as the tube radius gets smaller. Non-linear constitutive structures are also considered to show that the most effective mean flow rate enhancement for pulsating flows can be reached at the resonance frequencies.

In this paper the Graetz problem is addressed for the case of steady laminar flow of Newtonian fluids in tubes of arbitrary cross-section. The method herein presented models the velocity field in a general way so that the non-slip boundary condition is met by a wide variety of cross-section contours. The energy equation is next solved for the temperature field, which is also mathematically modeled so that the thermal condition at the wall is met, for all cases, in the corresponding tube contours. Main results are the temperature distribution for different tube geometries that include the triangular and square cases.

The lubrication of a non-Newtonian liquid by a Newtonian fluid in the concentrically stratified laminar flow of two immiscible fluids in a horizontal tube has been investigated experimentally by an opto-mechanical method. Data for the interfacial velocity and the total volume flow rate for two zero shear rate viscosity ratio are presented. The results of this investigation are useful in solving high wax content crude oil transportation problems and in the design of lubricated pipelines.

Flow enhancement effects due to different waveforms in the tube flow of rheologically complex fluids driven by a pulsating pressure gradient are investigated. It is found that the squarer the waveform the larger the enhancement. In each case the enhancement is strongly dependent on the viscosity function, but the elastic properties also play an important role. We determine that considerable energy savings may be obtained in the transport of viscoelastic liquids if an oscillatory gradient is superposed on a mean gradient. The closer the oscillation to the square wave the larger the energy savings.

Analytical solutions for the velocity and temperature fields in a viscous fluid flowing over a non-linearly stretching sheet are obtained via Galerkin–Legendre spectral method. The application of spectral methods to this problem is novel as well as the concept of the non-uniqueness of the solution and the efficient algorithms developed in this paper. The governing partial differential equations are converted into a non-linear ordinary differential equation for the velocity field f and a variable coefficient linear ordinary differential equation for the temperature field θ by a similarity transformation in the semi-infinite physical domain. A coordinate transformation is introduced to map the physical state space into a bounded computational domain. It is shown that Galerkin–Legendre spectral method is the most efficient among spectral methods that lead to the analytical solution of the governing set of non-linear differential equations in the computational domain. Computationally efficient algorithms are constructed for the velocity gradient and temperature profile computations and two distinct solutions of the field equations are presented.

Free surface flow of a layered medium of simple fluids driven by a torsionally oscillating, cylindrical rod is investigated. The stress, expressed as a series of multiple integrals of polynomials in the strain histories, is expanded into a Fréchet series in terms of the amplitude of the oscillation of the rod. A domain perturbation method is used to perturb the rest state. The mean shapes and deviations from flatness at the rod of the interfaces between layers are determined together with the flow field up to and including second order in the amplitude of the oscillation.

ABSTRACT: Flow of Giesekus fluids in straight, arbitrary but axially-symmetric non-circular tubes is investigated. The cross-sectional shapes are obtained through a one-to-one continuous mapping of the circular base contour. The primary longitudinal and the secondary fields are elucidated up to and including the third order in the Weissenberg number Wi.

Flow of a viscoelastic liquid in a cylindrical cavity, driven by rotating finite disks is investigated. The cylindrical sidewall is fixed and the covers rotate with different angular velocities either in the same or in opposite directions. A regular perturbation in terms of the angular velocity of the caps is used. The flow field is resolved into a primary azimuthal stratified viscometric field and a weaker secondary meridional field. Results are presented for a range of cylinder aspect and cap rotation ratios and viscoelastic parameters. Interesting instabilities of the fluid of second grade are discussed. The controversy surrounding the sign of the first Rivlin-Ericksen constant is completely irrelevant to the discussion. It is shown qualitatively that loss of stability occurs repeatedly and bifurcating flows exist for critical values of an elasticity parameter at fixed aspect and cap rotation ratio. Branching flows also occur at a fixed value of the elasticity parameter for critical values of the cap rotation ratio, when the aspect ratio is fixed.

The unsteady non-viscometric motion of a memory integral fluid of order three in a rigid, circular, straight tube has been investigated. The motion is driven by a constant longitudinal pressure gradient and a periodic forcing from the boundary made up of superposed sinusoidal, rotational boundary waves. A regular perturbation is used to study the time-periodic longitudinal field for a range of viscoelastic liquids and driving parameters. Qualitative results obtained are independent of the explicit forms of the constitutive functions, the kernels of the memory integral fluid of order three, which are needed only for quantitative predictions. It is shown that anomalous steady longitudinal viscometric flows may exist due to frequency cancellation. The elastic and shear rate dependent viscosity characteristics of the fluid play important parts in setting up the oscillatory velocity field. In particular, shear-thinning in periodic shear is the dominant mechanism in smoothing out the effects of elasticity, and in increasing the velocities. A parametric study of the longitudinal oscillatory velocity field is presented for a range of liquids and driving conditions. The integral fluid shows drastic longitudinal steady velocity increases due to the interaction of the oscillatory, zero mean time average, transversal shear field with the longitudinal simple steady shear. A parametric study of the change in mass transport is also presented for a range of liquids to show that contrary to what is sometimes assumed, both elasticity and shear-thinning in oscillatory shear play important roles in defining the enhancement. In particular, nonlinear-elastic properties of the integral fluid of order three act to decrease the enhancement driven by orthogonal waves.

The flow of a viscoelastic liquid driven by the steadily rotating bottom cover of a cylindrical cup is investigated. The flow field and the shape of the free surface are determined at the lowest significant orders of the regular domain perturbation in terms of the angular velocity of the bottom cap. The meridional field superposed on a primary azimuthal field shows a structure of multiple cells. The velocity field and the shape of the free surface are strongly effected by the cylinder aspect ratio and the elasticity of the liquid. The use of this flow configuration as a free surface rheometer to determine the first two Rivlin-Ericksen constants is shown to be promising.

Undercooling is a natural extension in a levitation environment due to the elimination of container induced nucleation giving access to a metastableregion of the phase diagram. It is important to solidification processes, and therefore, the knowledge of thermophysical properties in this region is crucial. The degree of undercooling determines the growth velocity, and is essential in selecting the metastable solid phase. The use of hydrogen gas reduces and removes heterogeneous nucleation catalysts (oxide and sulfide inclusions), and facilitates undercooling. EML has the following advantages compared to other levitation methods: • Contactless melting of the sample; elimination of container walls is important in studies of flow dynamics, glass formation, preparation of pure substances, undercooling and solidification. • Molten sample can be protected from oxidation by a vacuum or an inert gas. • It is feasible to solidify the sample in levitated position. • Electromagnetic stirring oc...

Start-up thin film flow of fluids of grade three over a vertical longitudinally oscillating solid wall in a porous medium is investigated. The governing non-linear partial differential equation representing the momentum balance is solved by the Fourier-Galerkin approximation. The effect of the porosity, material constants as well as oscillations on the drainage rate and flow enhancement is explored and clarified.

The shape of the free surface and the flow field of a simple fluid driven by the steadily rotating bottom cap of a c y l i n d r i c a l cup is investigated. A regular domain perturbation in terms of the angular velocity of the bottom cap is used. The velocity field is a superposition of a strong primary, azimuthal field and a weaker secondary meridional f i e l d. The effect of the aspect ratio and viscoelasticity of the fluid results in multiple cell structures in the meridional plane. The free surface shape determined at the lowest significant order in the perturbation algorithm, is similarly affected by the same factors. Both the flow field and the interface shape are determined for a wide range of aspect ratios and viscoelastic parameters.

Poiseuille flaw of an elastico-viscous liquid in a straight, circular pipe driven by a pressure gradient oscillating about a non-zero mean is investigated. The simple fluid of the multiple integral type presents a flow enhancement which depends on the frequency and amplitude of the oscillation, magnitude of the mean pressure gradient and the material functions of the fluid. A closed form expression for the flow rate alteration, independent of any explicit representations for the material functions, is developed at the lowest order in the perturbation algorithm where nonlinear effects appear. Asymptotic analyses of the flow rate enhancement at small and large frequencies are presented.

The spread of an infectious disease is a random process, and a stochastic approach to the problem is justified. The susceptible-infectious-recovered model (SIR) describes the evolution of three types of individuals (in a small community) which undergo an infection and recovery mechanism. The model (and its variations) predicts the number of infected individuals over a certain period of time, gives an estimate of the maximum possible number of infected people, and predicts how long the disease will be threat to the examined community. Using a quantum mechanical approach, we investigate four variations of the original SIR model and compare our analytical findings with the computer simulation results. We also calculate correlations between infected and recovered individuals, and find a good agreement between theory and computer simulations.

POST #1, POST #2 & POST #3 were recently uploaded to this site; Post #1 gave a general introduction and view of the electron. Post #2 gave a mathematical derivation of such electron. Post #3 explained how the electron charge worked. In this short post, comments are made to clarify what the electron’s electric field is. Related comments on EM waves are also included.