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H‐301 tubes for thermal cracking heater were subjected to metallurgical analysis on 2nd October 2007. Results of this analysis indicate that these tubes are of ASTM A355P5 specification. A hard oxide layer formed on the outer surface that is exposed to high temperature and the hardness value on this surface was 250 HB30. The hardness value of other part of the metal was 128.5 HB30. The inner surface was deposited with by‐product of cracking process. The tube expanded in the direction of tube axis causing a little bend to this tube. The change in metal thickness was considered insignificant. Difference in hardness between exposed and new tube was only 10 HB30, which means that the difference in mechanical properties between these tubes were very small. According to the class of damage, the microstructure is still in the class between C and D. This means that only 2.5%—10% of life fraction the material has been consumed. Thus, the remaining life of the tube is about 90%. Based on these results, the tube still may be used for another 10 to 15 years if operating temperatures are in the recommended ranges (400–550°C).

The aim of this study is to characterize of soils using microwave radiation by the reflection techniques. The sample of soils was collected in Northern Peninsular of Malaysia. There are six types of soil have been indentified, which, sand, clay, loam, silty clay loam, silty loam and clay loam. We use the transmission of microwave using Gunn Diode Transmitter with frequency of 10.525 GHz and the pipette method. The result shows that, the soil type can be indentified using intensity values based on the percentages of the clay. The proposed technique also can be used to characterize soils using by microwave radiation.

Energy is essential for socio‐economic development. Any nation's standard of living is closely related to its access to energy. To put into perspective, the per capita electricity consumptions in developed countries of the Organisation for Economic Cooperation and Development (OECD) is currently estimated at 8600 kilowatts‐hour per year as compared to the consumption rates in Malaysia and some African countries of 3300 and 50 kilowatts‐hour per year, respectively. Energy is therefore an important pre‐requisite for achieving the Malaysian vision of becoming a developed nation by the year 2020, in that it is needed not only for industrialization programme but also in maintaining quality of life. In Malaysia, the main concern currently is still on the supply in term of adequacy, reliability and quality; and moving slowly but steadily towards security, sustainability, environmentally friendly and contribution to climate change. With this new dimension, nuclear power emerged as a good match to a possible alternative in the comprehensive national energy policy. Many studies presented the positive aspects of nuclear power while others indicated the bad sides and potential risks. This paper will highlight some of those pros and cons as well as the potential risks beside a discussion on relevant requirements for a nuclear power programme in particular those of interest to the professionals in the physical sciences.

The application of Infrared Thermography (IRT) as passive method is widely used and accepted by industry. However, IRT technology as transient or active method is considerably new for industry in term of measuring defect in Non‐Destructive Testing (NDT) activities. The primary objective of this paper is to present an experimental study of determination of artificial defect in material using active thermography, in particular to pulsed thermal NDT (TNDT). Both terminology and basic principles in TNDT will be discussed. It is shown that several factors may influences TNDT results. As a conclusion, this study has confirmed the ability and potential of TNDT as a technique for defect determination in material.

The corrosion inhibition of aluminum and its alloys is the subject of remarkable technological importance due to their increased industrial applications. This paper reports the results of the corrosion inhibition properties of AA6061 and AA6063 aluminum alloys in tropical seawater using sodium benzoate as an inhibitor. It was found that the corrosion inhibition occurred through the adsorption on the surfactant on the metal surface without modifying the mechanism of corrosion processes.

The catalytic behaviour of undoped NiO and doped Pr2O3‐NiO catalysts toward CO2/H2 methanation reaction has been performed. The result showed 100% conversion of CO2 to CH4 in the presence of H2 for doped 60Ni‐40Pr at 300 °C, while for undoped NiO, there was only 40% of CO2/H2 methanation at the same temperature. The result corresponds to the presence of higher specific surface area of 60Ni‐40Pr compared to undoped NiO catalyst. The XRD analysis showed that this catalyst has some degree of amorphous properties and the existence of individual phases of cubic NiO and cubic Pr2O3, which serves more active site for CO2/H2 methanation. In addition, complimentary results obtained from SEM showed the present of homogeneous smaller particle size, which support the good performance of 60Ni‐40Pr catalyst towards CO2/H2 methanation.

The monolayer of carbon atoms in a hexagonal lattice is called graphene. It is a monoatomic layer of graphite. The stacking of hexagons one over the other creates a variety of layers. We can stack in such a way that the hexagons of the first layer coincide with the hexagons of the next layer or they may be displaced. In this way we are able to make three types of layer stacks of graphene. These are called A, B and C types. We have found that a single layer of graphene shows a small gap of 27.212 meV. In the two layers of the AA type also the crossing is avoided. The energy from the apparent crossing point towards higher energies is not equal to that towards lower energies. The energy levels are not symmetric with respect to the apparent crossing point. In the AB type stacking for two layers the energy gap is 4.8 meV. The energy gap for a variety of stacking of layers has been obtained from the non‐relativistic Schrodinger theory.

Typically, most of the commercially available GaN‐based LEDs (Light Emitting Diodes) are grown on sapphire as their substrates. Due to the insulating substrate, lateral current injection is employed so that the anode and cathode contacts are in side‐by‐side configuration. During the etching process, the possibility of slanted mesa sidewall to form is higher. In this work, the influence of slanted mesa sidewall are studied while its light emitting area size and contacts position are maintained. The comparison for optical output power, current‐voltage, thermal dissipation and distribution characteristics of different angles of slanted mesa sidewall are performed. Angles of slanted mesa sidewall are varied from angle‐in and angle‐out with reference to 90° at mesa edge. The simulation results revealed that with the increment of slanted angle, the LEDs performed better due to improved overall emission intensity and uniform current distribution of the devices. The angled sidewalls efficiently deflect photons that are initially guided laterally within the GaN epilayer in the off‐surface direction. As such, devices showed better overall performance.

The transmission coefficient through a Coulomb barrier in nuclear reaction is obtained by using the WKB approximation. Hence, we can determine the exact tunneling probability from this method. This probability can be applied in calculating the astrophysical thermonuclear reaction rates. One of the most important aspects in calculating the reaction rates is the value of the most effective energy, E0 for the reaction to occur. The Gamow peak produces a nonlinear equation that is solved iteratively to produce E0.

The sea surface temperature, SST of Sabah coastal area under clear sky conditions was investigated. Automatic Picture Transmission, APT thermal infrared data from National Oceanic Atmospheric Administration, NOAA satellite of Advanced Very High Resolution Radiometer, AVHRR was used. The APT data was obtained in real-time mode at Ground Receiving Station, GRS in Universiti Malaysia Sabah, UMS. An image processing approach and Planck distribution function method were used to convert the grey-level digital numbers of the APT imagery into radiance values. These data were then converted to 10-bit digital number data of High Resolution Picture Transmission, HRPT images for calibration purposes. Geometric correction was applied with ground control point for APT data. A single channel method together with radiosonde data has been used for the atmospheric and emissivity corrections. The satellite sensor SST was compared with in-situ measurements taken from ships at sea. The results from the SST obtained from APT data give 2.6 degrees C to 2.7 degrees C lower than in-situ data.

1g chitosan was dissolved in l00 mL of 1% acetic acid solution to prepare a chitosan acetate solution. The solution was then mixed with oleic acid. This chitosan acetate‐oleic acid was then made into thin film by the solution cast technique. The conductivity of the samples was measured from ambient to elevated temperature. The highest conductivity of the chitosan‐salt with 10 wt % oleic acid (OA) at room temperature was 8.35×10−9 Scm−1. The addition of OA has increased the dielectric constant, which implies the increase of dissociation of the salt thereby producing more free ions for conducting and hence increases the ionic conductivity.

We illustrate the optimization of the growth of multi‐wall carbon nanotubes (MWCNTs) using thermal chemical vapor deposition (CVD). Palm‐based dihydrostearic acid (DHSA) which was never been reported as a precursor, was used as the precursor over iron/nickel/manganese, iron/nickel/magnesium and iron/nickel/chromium trimetallic catalysts for the growth of MWCNTs. These trimetallic catalysts were prepared by sol‐gel method. MWCNTs produced were characterized by using Field Emission Scanning Electron Microscope (FE‐SEM) to indicate the production of nanotubes growth from palm DHSA. The density of the yield of MWCNTs produced differs with changes of the catalyst used during the nucleation process of MWCNTs. The crystallinity of MWCNTs was studied by X‐Ray Diffraction (XRD). Fourier Transform Infrared (FTIR) study was also been done for the prepared MWCNTs to check on the bonding occur in the produced MWCNTs.

Recent theoretical results of the standard model expectations on $\sin2\beta_{\rm eff}$ from penguin-dominated $b \to s$ decays are briefly reviewed.

In the current paper, we not only explain the fabrication and properties of an organic humidity sensitive field effect transistor using physical vapor deposition but also discuss the fabrication and properties of a photocapacitor made through spin‐coating technique. We also describe: (i) conduction mechanisms in organic semiconductors as hopping, band and/or tunneling one, and (ii) the possible ways to increase the mobility of charge carriers.

Quantum well width effect on threshold current density and optical performance of InGaN/GaN single quantum well (SQW) laser diode was determined and investigated. Various thickness (2–5 nm) of In0.13Ga0.87N wells and 12 nm GaN barriers were selected as an active region for Fabry‐Perot (FP) cavity waveguide edge emitting laser diode. The quantum confined Stark created a strong quantum well width dependence of threshold current density in the strained InGaN/GaN quantum well laser. Based on our simulation investigation, the exciton localization effect dominated the recombination emission in the thin quantum well structure; while the quantum confined stark effect (QCSE) dominated the recombination emission in the wide quantum well structure. Higher characteristic temperatures were obtained and significantly improved when the quantum well thickness was (2 to 3 nm).

Nanocrystalline anatase and amorphous Titanium Dioxide (TiO2) thin film have been prepared using sol‐gel method and deposited by spin coater technique. The influence of annealing temperature on the structural, surface morphology and electrical properties of the thin film is characterized by Scanning Electron Microscopy (SEM) and I‐V measurement. The result indicates that nanocrystalline anatase phase can be obtained at annealing temperature of 300 °C or above. Titanium dioxide thin films were deposited on silicon substrates. Annealing temperature at T = As deposited, 100 °C, 300 °C and 500 °C have been observed. As deposited substrates is also observed. The result indicated electrical properties of titanium dioxide thin films were changed with annealing temperatures. As the annealing temperature rises, the resistivity will be decreased. The SEM investigation showed that grain size of titanium oxide increased with higher annealing temperature. Furthermore, the SEM result indicated lattice matching between titanium dioxide and substrate is important to produce good quality titanium dioxide thin film after annealing process. The results suggest that surface porosity, electrical properties and surface morphology of titanium dioxide could be affected by changing annealing temperatures for electronic devices application.

Fundamental principles of the Einstein's Theory of Relativity (ETR) are the continuum space‐time axiom, the Mach principle and the constancy of the speed of light in a vacuo. It is shown by Whitehead (1922/2004) and Iqbal (1934/2004) that these axioms and other physical concepts involved are not independent of the German cosmological doctrine which are incompatible with the Christian‐English and Islamic cosmological doctrines. Similar to the method of evaluating the ETR done by Whitehead and Iqbal, we reevaluate the theory based on the Malay cosmological doctrine. It is shown that the present Einstein's and Whitehead's theory of space‐time is not fully consistent with the corresponding Islamic‐Malay cosmological doctrine. Views of Islamic scholars on the compatability of the Islamic cosmological doctrine with the Einstein's Theory are refuted. It is shown that the Islamic and Malay cosmological doctrines are potentially useful in proposing an innovative theory of relativity.

Vertical MOSFET has been introduced in the last few decades. As planar devices become smaller and smaller, vertical MOS transistor is one of the solutions for surpassing the short channel effects and pattern transfer. Thus, it is a promising approach to achieve channel lengths between 100 nm and 25 nm. In this work, we simulate sub‐100 nm single channel length vertical silicon MOSFET. The simulations are done with using ATHENA, DEVEDIT and ATLAS from SILVACO International. Input and output electrical characteristics of the vertical MOS transistors are investigated. The short channel effects of the vertical MOSFETs are explored. Due to the structure is not symmetry, source at top and bottom is also considered. The results also compared with experimental results from other researcher.

Solar models are important in our understanding of stars and stellar evolution. Solar models have been constructed using different methods. In this work, a solar model will be built using the fitting method. The model will incorporate the most recent input data. The model will be evolved to the current epoch starting from the zero‐age main sequence model.

The density functional theory is used to make models of clusters of atoms of arsenic and selenium. We are able to determine the bond lengths and angles for which the energy of the Schroedinger equation is minimum. The vibrational spectra of the optimized clusters are computed by using several different wave functions. It is found that the double zeta wave functions work the best. For the optimized clusters, we calculated the vibrational frequencies in each case by calculating the gradients of the first principles potential. We compare the calculated values with those measured experimentally from the Raman spectra of As‐Se glass. The calculations have been done for many clusters, for example, (i) AsSe (diatomic), (ii) As2Se (linear), (iii) As2Se (triangular), (iv) As3Se (triangular), (v) As4Se (square), (vi) AsSe3 (triangular), etc. From this study we identify that linear As–Se–As for which the calculated frequency is 27.6 cm−1 is in agreement with the experimental data.

Aluminum doped zinc oxide thin films were prepared through sol gel and spin coating technique from zinc acetate dihydrate and aluminum nitrate nanohydrate in alcoholic solution. The electrical properties and surface morphology study are investigated for the thin films annealed at 350∼500 °C. Zinc oxide thin films deposited on glass and silicon substrates were characterized using electron microscopy (SEM) and current‐voltage (I‐V) measurement scanning for surface morphology and electrical properties study respectively. The SEM investigation shows that zinc oxide thin films are denser at higher annealing temperature. The result indicates electrical properties of aluminum doped zinc oxide thin films are improved with annealing temperatures. The resistivity of aluminum doped zinc oxide thin films are decreased with annealing temperature up to 500 °C.

An explorative study was carried out to confirm Malaysian Physics teachers' perception that Archimedes' principle is a difficult topic for secondary level students. The interview method was used for data collection. The study sample was made of nine national secondary schools teachers from Miri, Sarawak. The data was analysed qualitatively using the Atlas‐ti version 5.2 software. The findings of the study showed that i) Archimedes' principle as compared to Bernoulli's and Pascal's is the most difficult principle of hydrodynamics for students, ii) more time was given in the teaching and learning (TL) of Archimedes principle compared to the other two principles, iii) the major TL problems include conceptual understanding, application of physics principles and ideas, and lack of mathematical skills. These findings implicate the need to develop corresponding instructional materials and learning kits that can assist students' understanding of Archimedes' principle.

The Cengal wood samples which are obtained from Tenaga National Berhad (TNB), is a raw material for heavy construction industry. The compression test is carried out by using an Instron Machine Series‐IX at different temperatures for the purpose of determining and understanding the mechanical properties of Cengal wood under fiber saturated point and as dried samples. Analysis is made from the results in the form of Young's modulus, E plotted against the temperature. From the test, the Cengal wood does not show a glass transition or softening when dried up to 140 °C because there is no significant decrease in the value of E during heating. For fiber saturated point, the glass transition temperature occurs at 40 °C when the E value is about 190 MPa while the second rapid drop occurs at 60 °C (155 MPa), which is due to the softening temperature of lignin. After the softening point, the wood becomes too soft and undergoes the process of decomposition due to small value of E.

The effects of immersion time and quantity of Erbium plated on Nanostructured Silicon (NSi) have been studied. Nanostructured Silicon was prepared by electrochemical method with an electrolyte composed of Hydrofluoric acid and Ethanol. The Erbium plating process was carried out by immersion technique with electrolyte composed of ErCl3 and Ethanol. The photoluminescence (PL) effect on NSi samples have been studied and shows a PL intensity is improves at certain immersion time and the PL peak shifts to the blue luminescence. The presence of Erbium conformed by X‐ray Photoelectron Spectroscopy (XPS). Fourier Transform Infrared Spectroscopy (FTIR) was also performed to study the chemical functional group changes after the plating process. The possible mechanism of the effects will be discussed in this paper.

This paper discusses the phase analysis of interference pattern from coherent light Nd:YAG 532 nm laser source. The Twyman‐Green Interferometer set‐up is used for generating the fringe pattern in the phase calibration. The piezoelectric transducer (PZT) is used to achieve the required phase shift of the fringe pattern. It was found that the system required 8.8 volts of out‐put DC voltage to shift 2π radians phase. The accuracy of optical phase measurement of the interference pattern is analyzed by wrapped phases of three‐phase stepping and four‐phase stepping procedures. Comparison of the experimental phase measurement data and the theoretical phase calculations are also highlighted.

Electron beam lithography is one of the most promising of nanolithographic techniques. The setup is similar to a Scanning Electron Microscope (SEM) and often a scanning electron microscope is used. EBL is able to provide high resolution patterning. However, the effect of electron scattering in resist and substrate leads to an undesired influence in the regions adjacent to those exposed by the electron beam. This effect is called the proximity effect. In this paper, we investigated the effect of dose exposure in Electron beam lithography (EBL) and proximity effect. We also show the image for several of dose exposure.

The tRNA molecule takes suitable amino acids to the ribosome for the formation of peptide bonds. In starting the peptide chain, the first amino acid taken to the ribosome is methionine. We have carried out calculations on the methionine‐tRNA and alanine‐tRNA complexes using mixed quantum mechanics ab‐initio and molecular mechanics method. The total energies and dipole moments have also been calculated. The amino acids chosen for this study, alanine and methionine have almost the same hydropath index. It is important to understand the physical properties and the environmental conditions in which the dipeptides cause the tRNA to attach to a wrong amino acid. One of the properties studied is the dielectric environment in which the bonding occurs.

The project is carried out using a small Mather type plasma focus device powered by a 15 kV, 30 μF capacitor. The filling gas used is argon. The ion beam generated is investigated by both time resolved and time integrated methods. Investigation on the dynamic of the current sheath is also carried out in order to obtain an optimum condition for ion beam production. The angular distribution of the ion emission is measured at positions of 0° (end‐on), 45° and 90° (side‐on) by using CR‐39 nuclear track detectors. The divergence of the ion beam is also determined using these detectors. A biased ion collector is used for time resolved measurement of the ion beam. Time of flight technique is employed for the determination of the ion beam energy. Average ion beam energy obtained is about 180 keV. The ion beam produced can be used for applications such as material surface modification and ion implantation.

Laughlin's theory of fractional charges is worked out in detail for small charges from 1/3 till 1/101. There is a small deviation between computed values and those obtained from the closed form expression. The ground state energy crosses that of the charge‐density waves. We develop a theory of fractional charges by using the quantum mechanics of angular momentum. We find that fractional charges can be expressed in terms of spin and the values of charges 0, 1, 1/3, 2/3, 2/5, 3/5, …, are produced. The angular momenta eigen values when subjected to flux quantization, yield plateaus of energies which are independent of the magnetic field. In this way we are able to predict that charges of ±2e, ±6e, ±10e, ±14e, …, are produced. The higher order term in the flux quantization also produces quasiparticles of charges of ±4e. These calculated values of the charges are the same as those found in the experimental data of quantum Hall effect in graphene, which is a mono‐atomic layer of carbon. Since the charge of the ...

This paper describes the results of ultrasonic goniometry measurement in Aquilaria (gaharu) wood. Ultrasonic wave was transmitted into the surface of gaharu wood and the reflected amplitudes by corner reflection were measured. The measurements were performed on gaharu sample with dimension of about 3 mm×15 mm×25 mm by attaching to corner reflector goniometer made of mild steel. The measurement results are explained and discussed.

Oxygen sensing properties of Er123 ceramic material utilizing hot‐spot phenomenon have been investigated. Bulk Er123 ceramic with relative density of 72 % was synthesized using solid‐state method and single‐phase structure of the material was confirmed by X‐ray diffraction. The Er123 sensor was fabricated by cutting the bulk sample into a rectangular rod shape. I‐V characterizations of the sensor before and after appearance of the hot spot were conducted in a chamber with controlled flow rate and partial pressure of oxygen and nitrogen gases. After appearance of the hot spot, the output current strongly depended on oxygen partial pressure (pO2) at a particular selected voltage. The sensor showed good sensing properties with minimum required electric field of about 1.7 V/cm for 0.025% to 100% pO2. The sensor showed very good reproducibility and stability of output current. The oxygen sensing properties are explained in terms of absorption of oxygen gas by the hot spot before dissociating into oxide ions an...

This paper describes the construction and testing at room temperature of a resonant photoacoustic cell which may be used to carry out photoacoustic measurements of opaque samples at various temperatures from 77 K to 300 K. It has the shape of the Helmholtz resonator with a microphone separated from the sample by a long narrow tube. An optical fiber leads the laser light to the sample. The photoacoustic cell was tested by measuring thermal diffusivity of various solid samples at room temperature. The testing shows that the photoacoustic cell is successful in measuring thermal diffusivities of various opaque samples.

Polonium is the only element with a simple cubic (sc) crystal structure. Atoms in solid polonium sit at the corners of a simple cubic unit cell and no where else. Polonium has a valence electron configuration 6s26p4 (Z = 84). The low temperature α‐phase transforms into the rhombohedral (trigonal) β structure at ∼348 K. The sc α‐Po unit cell constant is a = 3.345 A. The beta form of polonium (β‐Po) has the lattice parameters, aR = 3.359 A and a rhombohedral angle 98°13′. We have performed an ab initio electronic structure calculation by using the density functional theory. We have performed the calculation with and without spin‐orbit (SO) coupling by using both the LDA and the GGA for the exchange‐correlations. The k‐points in a simple cubic BZ are determined by R (0.5, 0.5, 0.5), Γ (0, 0, 0), X (0.5, 0, 0), M (0.5, 0.5, 0) and Γ (0, 0, 0). Other directions of k‐points are Γ (0, 0, 0), X (0.5, 0, 0), R (0.5, 0.5, 0.5) and Γ (0, 0, 0). The SO splittings of p states at the Γ point in the GGA+SO scheme for α‐...

Photoluminescence and morphology studies of Zinc Oxide (ZnO) thin films prepared by using Thermal Chemical Vapor Deposition (Thermal‐CVD) were investigated. The ZnO compound was synthesized from zinc acetate dehydrate which act as a starting material to form the ZnO thin films. It was deposited on silicon with low deposition temperature ranging from 400–600 °C with Au as a catalyst assisted. Surface morphology of the samples was examined by Scanning Electron Microscope and photoluminescence properties were studied using Photoluminescence Spectrometer. The surface morphologies of the ZnO nano‐flower structure was obviously obtained at deposition temperature of 400 °C. The individual nano‐rods diameter of nano‐flower is about 100–350 nm, but the end of nano‐rods are very sharp which is the size is less than 50 nm. Possible growth mechanism of ZnO nano‐flower also discussed. Room temperature PL spectra from the ZnO nano‐flower revealed a strong UV emission and broad green emission. This result is very useful...

Porous GaP have studied fabricated by using an argon‐ion laser beam (LIE) of energy 2.41 eV. We have studied the surface morphology of porous layers obtained using a Scanning Electron Microscope (SEM). The morphology of porous GaP layers changes rapidly with laser power densities and irradiation times. This advanced fabrication method have been used for synthesis porous silicon (p‐Si). The optical characteristic was used to illustrate changes in surface morphology and the intensity of emission of porous form as a function of etching conditions. The surface morphology studies have demonstrated the characterization of porous silicon. As well as both the size and shape of the structure depend on the nature concentration of etchant solution. The different size of pores form at different area of GaN shows that the etching rate is not uniform through out the whole surface of GaN. The porous GaN generated by electrochemical etching technique does not always produce similar surface morphology. However, the averag...

lead sulfide nanostructured thin film was prepared from colloidal lead sulfide nanoparticles with natural deposition technique. The size of PbS nanoparticles has been determined in the base of optical absorption spectrum. The influence of preparation method on the film surface morphology was studied by atomic force microscopy, and x‐ray diffraction. Experimental results have shown that the thin film uniformity has been improved when the number of deposited layer increased. Double layered PbS nanothin film has a self assembly morphology and can be used for surface plasmon applications.

Granular filter is widely used in removing suspended substance from treating water. Its reliability is well accepted and has been modified into different modes of operation and media combination, etc., in order to accommodate its different purposes of usage. A more conventional method in supplying adequate volume of potable water with minimum expenses involve, gravity flow of rapid filtration is normally used. Conventionally, engineer refers to filter design criteria in tabulated form of table before designing filtration unit. A slight different from conventional design parameters would normally require time for re‐calculation. The current studies have been conducted to develop a simulation model with user interface that is governed by some well accepted equations, such as, Carmen‐Kozeny and Ives‐Gregory models. This work is done to ease the work of engineers in making design decision. The simulated results are the total amount of water produced, time required in reaching particular head‐loss, amount of particulate mass accumulated within the filter, and the designated total head‐loss. Overall, the developed simulation model could be effectively implemented for filter design purpose, after some verification through laboratory experimentation or compilation of past experiments.

In the present study, five systems of samples have been prepared by the solution casting technique. Polymethylmethacrylate (PMMA) is used as a based polymer. Ethylene carbonate (EC) and propylene carbonate (PC) as plasticizers. The salt that was selected for this study is lithium triflate (LiCF3SO3). The pure PMMA sample is taken as a reference. The five systems are the (PMMA–EC) system, the (PMMA–PC) system, the (PMMA‐LiCF3SO3) system, the ([PMMA‐EC]‐LiCF3SO3) system and the ([PMMA–PC]‐LiCF3SO3) system. The conductivity for each system is characterized using impedance spectroscopy. The conductivity of the pure PMMA, the (PMMA–EC) system and the (PMMA–PC) system at room temperature is 2.37×10−9 Scm−1, 3.63×10−8 Scm−1 and 4.18×10−8 Scm−1 respectively. On addition of salt in the (PMMA–LiCF3SO3) system, the conductivity is increased by two orders of magnitude. The conductivity for the ([PMMA–EC]‐LiCF3SO3) system and the ([PMMA–PC]‐LiCF3SO3) system is 3.54×10−5 Scm−1 and 2.06×10−5 Scm−1 respectively. The cond...

Aluminium and zinc target were co—sputtered on silicon (111) substrates using DC magnetron sputtering in the pure argon atmosphere. These films were then underwent the thermal annealing in different ratios of nitrogen and oxygen for 1 hour to form thin oxide films. P—type conduction in ZnO thin films have been realized by the Al—N codoping method, whereby the lowest resistivity of 3.41×10−3 Ω⋅cm and the highest carrier concentration of 1.54×1022 cm−3 was achieved for sample prepared at annealed temperature of 300 °C.

In this work the technique of laser‐induced breakdown spectroscopy (LIBS) has been used for the elemental analysis of cigarettes. For this purpose emission spectra have been measured of eleven different kinds of cigarette brands sold and/or produced in Pakistan. Analysis of the spectral peaks observed shows that Na, Mg, Al, K, Ca, Cr, Fe, Sr and Ba are contained in all brands. Exhibiting the LIBS results, the powerful potential of this method for the identification of the elemental content of cigarettes is demonstrated.

The codoped ZnO thin film were deposited by DC magnetron sputtering on silicon (111) followed by annealing treatment at 200 °C to 600 °C for 1 hour in nitrogen and oxygen gas mixture. P—type conduction of Al—N codoped ZnO thin films were obtained at 300 °C with the lowest resistivity of 3.412×10−3 Ω⋅cm and highest carrier concentration of 1.54×1022 cm−3. Structural investigation was carried out by atomic force microscope (AFM) and X—ray diffraction (XRD). Results showed that heat treatment had influenced the structure of the films.

This paper describes the characteristics of the multihole collimator gamma camera that is simulated using the combination of the Monte Carlo N‐Particles Code (MCNP) version 5 and in‐house software. The model is constructed based on the GCA‐7100A Toshiba Gamma Camera at the Royal Surrey County Hospital, Guildford, Surrey, UK. The characteristics are analyzed based on the spatial resolution of the images detected by the Sodium Iodide (NaI) detector. The result is recorded in a list‐mode file referred to as a PTRAC file within MCNP5. All pertinent nuclear reaction mechanisms, such as Compton and Rayleigh scattering and photoelectric absorption are undertaken by MCNP5 for all materials encountered by each photon. The experiments were conducted on Tl‐201, Co‐57, Tc‐99 m and Cr‐51 radio nuclides. The comparison of full width half maximum value of each datasets obtained from experimental work, simulation and literature are also reported in this paper. The relationship of the simulated data is in agreement with the experimental results and data obtained in the literature. A careful inspection at each of the data points of the spatial resolution of Tc‐99 m shows a slight discrepancy between these sets. However, the difference is very insignificant, i.e. less than 3 mm only, which corresponds to a size of less than 1 pixel only (of the segmented detector).

We review experiments colliding electrons(/positrons) on protons at high energies at HERA, focussing on the ZEUS experiment. We describe the ZEUS detector, including its data acquisition system, and look at a specific part, namely the electronic system for its calorimeter readout control, in more detail. Data analysis is described, and results pertaining the proton structure is given. It is found that the naive quark model cannot explain the results obtained at small fractional momentum, and this requires quantum chromodynamics. Also it is found that diffractive reactions, with large rapidity gaps, contribute substantially; efforts are being carried out to understand them.

This paper presents the influence of polysilicon depletion effect (PDE) on the potential drop across polysilicon gate. The effect of the gate doping and oxide thickness variations on the PDE has been investigated using MINIMOS 6.1 respectively. These parameter variations have been shown to be the factors that contribute to the polysilicon‐gate depletion effect that lead to the increase of the potential drop and degradation in device performance. Besides that, polysilicon depletion effect can be improved by reducing the oxide thickness (tox) and gate doping concentration (Np).

This paper describes a method to verify the overall design of our electron accelerator. It is free from corona or spark discharge phenomenon. This locally designed electron accelerator facility is located at Nuclear Malaysia Complex, Bangi, Selangor. In this study, we describe the geometry of the pressure vessel filled with SF6 gas at 2 atm to enclose the high voltage area of the accelerating tube. The Poisson's equation is used to calculate the contours of the electric field that is created between the cathode of −160 kV maximum and the wall of the vessel. The nearest sharp edge between the cathode and the pressure wall is 163 mm apart. The calculation is based on finite element method (FEM) for electrostatic charges in order to obtain an electric field contour in two‐dimensional plane. We found that the surface charge density of the cathode is 1.1×10−5 C/m2 for the corona glowing seen at −90 kV. Moreover, the highest electric field near to (about 5 mm from) the sharp edge is about 2.7 MV/m, which is les...

In articular cartilage, Ca, P, K and S are among some of the well known co‐factors of the metalloproteinases enzymatic family, the latter playing a pivotal role in the growth and degeneration of the collagenous bone‐cartilage interface of articulating joints. Current study forms part of a larger investigation concerning the distribution of these and other key elements in such media. For the purpose of evaluating these low atomic number elements (Z⩽20), use was made of the capabilities of the LUCIA Station, located at the synchrotron facility of the Paul Scherrer Institute (PSI). Using an incident radiation energy of 4.06 keV, a synchrotron radiation micro x‐ray fluorescence (SR‐μXRF) technique was applied in examining the distribution of the essential elements Ca, P, K and S in the bone‐cartilage interface of both healthy and diseased (osteoarthritic) areas of an equine metacarpophalangeal joint. The SR‐μXRF mappings and line profile patterns have revealed remarkable changes in both the pattern and absolu...

We find that the predictions of the Dirac equation agree with the idea of fractional charges. We have introduced the combination of spin and orbital quantum numbers, including the negative sign for spin, in such a way that there occur fractional charges through the Bohr magneton. This leads to doubling of eigen values so that we define an additional matrix the properties of which are important when magnetic field is present. There is a spin‐charge coupling so that spin 12 particle can have the zero or one charge. The Dirac equation can accommodate not only charges of 0 and ±e but also fractional values such as 1/3 and 2/3. For spin 12 there are two eigen values, ±(1/2)gμBH but when two different g values are taken into account, there are four eigen values, ±(1/2)g±μBH, which are fractionally charged. The Hall resistivity becomes spin dependent. The spin 12 particle with zero orbital angular momentum, has two values of resistivity, 3h/e2 and 3h/(2e2) which means that when magnetic field is varied the resis...

Simulation of a neutron radiography system was performed to investigate the spatial resolution properties of the system. A cadmium plate was imaged by neutrons using a plane radiographic detector placed behind the plate. The detector was evoked by the radiographic tally facility of the MCNP codes. Radiograph of the cadmium plate was obtained and the edge spread function data were extracted from it. Modulation transfer functions which give the spatial resolution properties were calculated from the edge spread function data.

Multi‐wall carbon nanotubes (MWCNTs) were synthesized by thermal chemical vapor deposition (CVD) and were intercalated with iodine at several different temperatures. Iodine doping was achieved by immersing the nanotubes in molten iodine. The sample produced was characterized by means of infrared IR as a point to the presence of covalent C‐I bonds in the sample with retention of the sp2‐hybridizated carbon atoms. For all samples doped at different temperatures, the C‐I bonding happen to occur based on IR spectra which was indicated by peaks around 600–650 cm−1. X‐ray diffraction (XRD) characterization was used to study on the crystallinity of the undoped and iodine‐doped MWCNTs. It was shown that, iodine‐doping of the MWCNTs gives significant changes in the XRD spectra compared to the undoped MWCNTs. With various doping temperature, the XRD spectra shows the different crystallinity.