Finite Differences Time Domain, FDTD

We present a comprehensive theoretical framework for protein folding based on the Ducci Unied Spectral Theory (dust). This framework treats proteins as dynamical spectral systemscollections of coupled oscillators whose collective behavior emerges from the interplay between sequence-encoded spectral signatures, environmental spectral elds, and fundamental prime-periodic organizing principles. We demonstrate that the same amino acid sequence can manifest dierent spectral eigenstates corresponding to distinct conformational states, providing a unied explanation for phenomena including protein misfolding, prion diseases, intrinsically disordered proteins, allosteric regulation, and amyloid formation. The theory makes specic, testable predictions including: (1) discrete scale invariance in protein vibrational spectra with characteristic ratio λ ≈ 4.0-4.2, (2) enrichment of protein domain sizes at prime numbers, (3) cotranslational folding pathway dependence on translation speed, (4) picosecond-timescale allosteric communication via spectral mode coupling, and (5) prion conversion eciency correlating with spectral similarity between species. We develop the complete mathematical formalism, computational implementation strategies, and experimental validation protocols. This work unies quantum mechanics, statistical mechanics, structural biology, and evolutionary theory under a single spectral framework, oering new principles for protein engineering, drug design, and understanding biological self-organization.

This paper introduces a compact textile patch antenna fabricated on a single-layer felt fabric substrate. Initially, a novel structure called the Gear-Shaped Slot-Loaded (GS-SL) radiator with a U-shaped partial ground is designed and optimized using a state-of-the-art Machine Learning (ML) tool through various evaluation stages. The dominant operating frequency is observed at 3.5 GHz, with a realized gain of 1.14 dBi and radiation efficiency of 83%. Measurement results of the final GS-SL design show good agreement with simulations, with an operating bandwidth exceeding 436 MHz in free space (FS). Furthermore, the performance of the antenna is validated through on-body assessment when placed on the human chest. Ultimately, this research contributes to the development of an adaptive and data-driven design methodology that is not typically applied in similar flexible designs. Moreover, GS-SL design enables controlled current distribution and better coupling balance.

This paper introduces a compact textile patch antenna fabricated on a single-layer felt fabric substrate. Initially, a novel structure called the Gear-Shaped Slot-Loaded (GS-SL) radiator with a U-shaped partial ground is designed and optimized using a state-of-the-art Machine Learning (ML) tool through various evaluation stages. The dominant operating frequency is observed at 3.5 GHz, with a realized gain of 1.14 dBi and radiation efficiency of 83%. Measurement results of the final GS-SL design show good agreement with simulations, with an operating bandwidth exceeding 436 MHz in free space (FS). Furthermore, the performance of the antenna is validated through on-body assessment when placed on the human chest. Ultimately, this research contributes to the development of an adaptive and data-driven design methodology that is not typically applied in similar flexible designs. Moreover, GS-SL design enables controlled current distribution and better coupling balance.

This paper introduces a compact textile patch antenna fabricated on a single-layer felt fabric substrate. Initially, a novel structure called the Gear-Shaped Slot-Loaded (GS-SL) radiator with a U-shaped partial ground is designed and optimized using a state-of-the-art Machine Learning (ML) tool through various evaluation stages. The dominant operating frequency is observed at 3.5 GHz, with a realized gain of 1.14 dBi and radiation efficiency of 83%. Measurement results of the final GS-SL design show good agreement with simulations, with an operating bandwidth exceeding 436 MHz in free space (FS). Furthermore, the performance of the antenna is validated through on-body assessment when placed on the human chest. Ultimately, this research contributes to the development of an adaptive and data-driven design methodology that is not typically applied in similar flexible designs. Moreover, GS-SL design enables controlled current distribution and better coupling balance.

In this paper, we present a method to incorporate the intraband and interband terms of the surface conductivity of graphene into the finite-difference time-domain (FDTD) method. The method is based on approximating the surface resistivity of graphene by a series of partial fractions in terms of real or complex conjugate pole-residue pairs. Then, a discrete time-domain surface boundary condition at the graphene sheet is generated, which is then incorporated within the FDTD method using the infinitesimally thin sheet formulation. Numerical examples are presented to validate and demonstrate the capabilities and advantages of the proposed approach.

We present a conditional shell-geometric selection mechanism for the fine-structure coupling α within the Relator framework on the paired spaces ℂ and ℝ³. Starting from the kinematical lock Rω = c, the construction fixes the minimal pinned electron branch, its matching-shell geometry, the scalar cavity--shell slowdown block 𝒟_C(α), the vector shell constant Λ_geom, and the universal single-log coefficient 𝒞_log = 1/3. The Alpha Lock Point then selects the coupling through the compatibility condition between the scalar shell law and the vector shell geometry. No measured value of α, no QED anomaly coefficient, and no fitted parameter enters this primary closure.
The resulting finite-rank realization places the emergent coupling in the immediate neighborhood of the accepted fine-structure benchmark, while keeping all benchmark comparisons external to the derivation. As a secondary consequence, the same scalar branch, lifted through the ALP map and the operational orbital slowdown map, generates a pure-photonic electron g−2 series. Its first benchmarked coefficients provide a stringent cross-check against the universal QED sequence, and its higher coefficients, beginning with the twelfth-order pure-photonic term A₁⁽¹²⁾, are falsifiable predictions of the specified no-free-parameter shell realization.

In last decades, plasmonics gives very high attention and closely involves in the main domains of nanophotonics which can control of optical fields at the nanodimension level. Its most striking property is to concentrate and enhance the electromagnetic field on the nanometer scale especially in solar cell. In plasmonic field, Nobel metals used as nanoparticle where density of electron gas which oscillates at surface plasmon frequency at the same time also improves absorption by scattering. So the use of plasmonic in solar cell gives better opportunity to enhance efficiency by absorption as the optical spectrum loss are most part of total loss in solar cell. In this paper, we investigate the effect of nanoparticle dimension for enhancement of extinction in terms of absorption and scattering by means of surface plasmon and also studied finite-difference time domain based proposed model which shows improvement in various simulated surface plasmonic fields components.

We investigate theoretically a semiconductor quantum wire under the effect of an intense offresonant cw laser. We show that in the regime of strong exciton-phonon coupling the light-dressed ground state of the wire reveals symmetry-breaking features, leading to local lattice deformations. Due to the off-resonant nature of the excitation, the deformations are reversible and controllable by the intensity and frequency of the laser. We calculate the light-induced strain forces on the lattice in the case of an organic quantum wire.

This study presents a new method for estimating the optimal impedance matching of the antenna based on the theory of characteristic mode (CMs). This method considering two models of the antenna represented in CPW-fed patch with and without ground plane. The point of intersection of the first two dominants modes indicates the frequency at which the impedance matching of the antenna equal or close 50 O. The characteristic mode analysis (CMA) of the models involves the analysis of antennas made of flexible materials without taking the effects of the substrate layer or excitation into account. In the design process, both CMA and the method of moments (MoM) are used with the same electromagnetic simulation software. Furthermore, this works examines the performance of a flexible monopole antenna developed for a wide frequency range in close proximity to the human body, particularly around swelling feet, chest, and arms of varied sizes. The antenna in this paper can be operates in wideband with several significant wireless frequency bands, including 2.45 GHz, 3.6 GHz, 5.5 GHz, and 5.8 GHz.

Surface plasmon resonance (SPR) sensors are proficient at detecting minute changes in refractive index, making them ideal for biomolecule detection. Traditional prism-based SPR sensors encounter miniaturization challenges, encouraging exploration of alternatives like fiber optic-based SPR (FO-SPR) sensors. This study comprehensively investigates the effects of material and geometrical parameters on the performance of single-mode FO-SPR sensors using Maxwell's equation solver software based on the finite-difference time-domain (FDTD) method. The findings highlight the influence of plasmonic thin film materials and thickness on SPR spectrum profiles and sensitivity. Silver (Ag) demonstrates superior performance compared to copper (Cu) and gold (Au) in transmission type, achieving a sensitivity of up to 2 × 103 nm/RIU, while the sensitivities of Cu and Au are lower. Probe length and core diameter impact spectrum profiles, specifically resonance depth, without affecting sensitivity. Furthermore, variations in core refractive index influence both spectrum profiles and sensitivity. Probe types significantly affect both spectrum profiles and sensitivity, with the reflection type surpassing the transmission type. These results provide suggestions for optimizing FO-SPR sensors in biotechnological applications

In this article, we developed and implemented the convolutional perfectly matched layer (CPML) for the hybrid implicit explicit finite‐difference time‐domain (HIE‐FDTD) method. The method is validated against the conventional FDTD‐PML method and is found promising. The development of CPML is able to extend the HIE‐FDTD to open surface problems, which works at higher CFL numbers in comparing to the conventional FDTD method. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 3106–3109, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22962

Microstrip patch antennas are considered more important in these days. This is due to their characteristics in terms of possible geometries that make them convenient for different applications, so the simplicity in their structures, the suitable size, and bandwidth improvement are becoming the significant design for the practical application of antennas. In this paper, circular microstrip patch antenna is designed. With the proposed concept, high bandwidth is achieved up to 40.95% (17.21-11.36) GHz at 29.18 dB return loss and 1.07 VSWR. On the other hand, the maximum peak gain is maintained 15 dB at some frequencies in the band. All the simulation results are discussed and presented. The structure of the proposed antenna consists of patch plane and the ground plane, while the substrate layer with dielectric constant of 2.2 is placed as a sandwich between them. FEKO software simulator version 7.0 based on the method of moment (MOM) is used for the simulation process. Microstrip line with the edge port is adapted to feeding the antenna.

In this program, 2-D FDTD source code was introduced with references for beginners so that a progressive series of simulations including model creation, source code modification, compilation, results output on display while introducing some of the specific analysis cases such as wire and reflector antenna, waveguide, diffraction, scattering, shielding, and cavity could be experienced. With this, it has become possible to introduce specialized content at the same level of researchers of about 20 years ago to the current lab's student experiments level. In the future, this educational training will lead to the development of a free electromagnetic field and wave simulator that is suitable for practical use.

We consider the nonlinear optical response of a GaAs layer excited by an ultrafast laser pulse consisting of only a few cycles. The third harmonic component of the transmitted pulse is calculated and compared with experimental results. We use a reduced set of the semiconductor Bloch equations as a model of the electronhole system. To describe the propagation of the ultrashort pulse we apply the integral equation method, which explicitly follows time and space evolution without the slowly varying envelope approximation. We use a procedure that efficiently includes the background refractive index, which is very important in the interpretation of the experimental results.

We consider the nonlinear optical response of a GaAs layer excited by an ultrafast laser pulse consisting of only a few cycles. The third harmonic component of the transmitted pulse is calculated and compared with experimental results. We use a reduced set of the semiconductor Bloch equations as a model of the electron‐hole system. To describe the propagation of the ultrashort pulse we apply the integral equation method, which explicitly follows time and space evolution without the slowly varying envelope approximation. We use a procedure that efficiently includes the background refractive index, which is very important in the interpretation of the experimental results.

Structural and mechanical properties of ternary CdZnTe nanowires have been investigated by performing molecular dynamics simulations using an atomistic potential. The simulation procedures are carried out as uniaxial stretching and compression at 1 K and 300 K. The results demonstrate that the mechanical properties of CdZnTe ternary nanowires show significantly a dependence on size and temperature under uniaxial stretching and compression.

The main objective of this study is to investigate the influences of mechanical strain on optical properties of ZnO nanowire (NW) before and after embedding ZnS nanowire into the ZnO nanowire, respectively. For this work, commercial finite element modeling (FEM) software package ABAQUS and three-dimensional (3D) finite-difference time-domain (FDTD) methods were utilized to analyze the nonlinear mechanical behavior and optical properties of the sample, respectively. Likewise, in this structure a single focused Gaussian beam with wavelength of 633 nm was used as source. The dimensions of ZnO nanowire were defined to be 12280 nm in length and 103.2 nm in diameter with hexagonal cross-section. In order to investigate mechanical properties, three-point bending technique was adopted so that both ends of the model were clamped with mid-span under loading condition and then the physical deformation model was imported into FDTD solutions to study optical properties of ZnO nanowire under mech...

We develop summation-by-parts operators with minimal dispersion errors both near and far from boundaries and interfaces. Such operators are superior to classical stencils for problems involving high frequency waves or multi-frequency solutions over long time intervals with a relatively coarse spatial mesh. This is demonstrated by solving the Taylor-Green vortex flow with optimised and classical operators both in a purely periodic setting as well as in the presence of numerical interfaces.

A quantum theory of quantum well polaritons in semiconductor microcavities is developed. The model takes into account the coupling between the exciton level and the structured continuum of electromagnetic modes relative to the particular geometry of the microcavity. A general equation for the polariton dispersion is obtained as a function of the cavity and exciton parameters. The equation is valid in both weak and strong coupling regimes and reproduces the existing measurements of microcavity polariton dispersion. A model for the polariton luminescence is then derived from the theory. It is possible to define a polariton decay rate only when the resonances in the polariton density of states can be considered as quasimodes. The two limiting cases of very weak and very strong coupling regimes are consequently identified. In these cases the polariton radiative probabilities are derived for light emitted on the left and right sides of the microcavity separately. The influence of the microcavity structure on the polariton dispersion and radiative rates is discussed and in particular the role of the microcavity leaky modes is described in detail. A discussion of the luminescence mechanism in the intermediate coupling case is also presented.

This study investigated the absorption efficiency of GaAs/In 0.2 Ga 0.8 As cylindrical coreeshell nanowire (NW) solar cells with a circular cross-section for normal incident light. Numerical results obtained through finite-difference timeedomain simulation showed that NW dimensions influenced the absorption efficiency of the solar cells. The band structure of the wires was also investigated.

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Silicon (Si)-based integrated photonics is considered to play a pivotal role in multiple emerging technologies, including telecommunications, quantum computing, and lab-chip systems. Diverse functionalities are either implemented on the wafer surface ("on-chip") or recently within the wafer ("in-chip") using laser lithography. However, the emerging depth degree of freedom has been exploited only for single-level devices in Si. Thus, monolithic and multilevel discrete functionality is missing within the bulk. Here, we report the creation of multilevel, high-efficiency diffraction gratings in Si using three-dimensional (3D) nonlinear laser lithography. To boost device performance within a given volume, we introduce the concept of effective field enhancement at half the Talbot distance, which exploits self-imaging onto discrete levels over an optical lattice. The novel approach enables multilevel gratings in Si with a record efficiency of 53%, measured at 1550 nm. Furthermore, we predict a diffraction efficiency approaching 100%, simply by increasing the number of levels. Such volumetric Si-photonic devices represent a significant advance toward 3D-integrated monolithic photonic chips.

This paper provides a simple hybrid design and numerical analysis of the graphene-coated fiber-optic surface plasmon resonance (SPR) biosensor for breast cancer gene-1 early onset (BRCA1) and breast cancer gene-2 early onset (BRCA2) genetic breast cancer detection. Two specific mutations named 916delTT and 6174delT in the BRCA1 and BRCA2 are selected for numerical detection of breast cancer. This sensor is based on the technique of the attenuated total reflection (ATR) method to detect deoxyribonucleic acid (DNA) hybridization along with individual point mutations in BRCA1 and BRCA2 genes. We have numerically shown that momentous changes present in the SPR angle (minimum: 135 % more) and surface resonance frequency (SRF) (minimum: 136 % more) for probe DNA with various concentrations of target DNA corresponding to a mutation of the BRCA1 and BRCA2 genes. The variation of the SPR angle and SRF for mismatched DNA strands is quite negligible, whereas that for complementary DNA strands is considerable, which is essential for proper detection of genetic biomarkers (916delTT and 6174delT) for early breast cancer. At last, the effect of electric field distribution in inserting graphene layer is analyzed incorporating the finite difference time domain (FDTD) technique by using Lumerical FDTD solution commercial software. To the best of our knowledge, this is the first demonstration of such a highly efficient biosensor for detecting BRCA1 and BRCA2 breast cancer. Therefore, the proposed biosensor opens a new window toward the detection of breast cancers.

The aim of this paper is to derive "aggravation factors " (AGFs) quantifying the difference between 2D site response and the corresponding 1D estimate for numerous quantities of engineering interest such as response spectra and ten scalar ground motion intensity parameters (GMIPs). The raw results are a huge collection of AGFs derived by numerical simulation for a total 154692 receivers located at the surface of 894 valleys exhibiting a trapezoidal (131) or triangular (18) shape, with six different velocity contrasts. A simple statistical analysis first allows to identify the respective order of magnitude of these AGFs for each GMIP. In a second step, a neural network approach is used to provide a set of analytical relationships quantifying the coupled effects of a limited number of geometrical and mechanical parameters for all the considered GMIPs, and different positions within the valley. The AGFs are found to be component dependent, with larger values for out-of-plane ...

vides a quadrature phase for 2.4 GHz and an octal phase for 5.2 GHz to generate an IQ signal for the sub-harmonic mixer. Figure 3 shows the sub-harmonic mixer schematic [3]. This mixer can also be used as a traditional Gilbert mixer if LO_0 port is connected to LO_180 port; and the LO_90 port is connected to LO_270 port simultaneously. Therefore, the circuit design can be simplified. There is an additional function of this mixer, which is a band selector. Depending on the receiving RF signal strength, a band-selecting control signal coming from the baseband can be used to control the on/off of this mixer. Because of this mechanism, we can easily select which band we chose before the bandpass filter. A 10 MHz center frequency and 20 MHz bandwidth polyphase band-pass filter is designed to provide the image rejection and filtering out the unwanted high frequency signal. To save power consumption and chip area, gm-C cell is implemented for this polyphase band-pass filter. 3. MEASUREMENT RESULT This concurrent compact dual-band receiver is implemented using HHNEC 0.18-m CMOS 1P6M technology. For a 1.8 V power supply, the overall power consumptions is simulated to be 66.1 mW. Table 1 summarizes all the measurement results. The proposed dual-band receiver has a fairly good performance as compared with the conventional receivers of individual receiving paths (as shown in Table 2). For noise issue, differential design concept is introduced. In addition, we not only use double guard ring layout style (N-well and P-substrate) to surround each individual block, but also individual power supply is used for each block. Another layout consideration is the RF signal penetrating through substrate issue; therefore, a metal1-shielding layer is added to form an ideal ground plate. Figure 4 shows the die photo of the proposed RF front-end chip with a die size of 2450 ϫ 1700 m 2. Figure 5 shows the dual-band receiver and Figure 6 shows the measured results. 4. CONCLUSION A low-cost and low-power IEEE 802.11a/b/g compact dual-band radio receiver for wireless LAN applications has been designed in a standard 0.18-m CMOS 1P6M technology. To save chip area, sub-harmonic mixer is used so that only one multi-modulus synthesizer is needed for this compact dual-band receiver design. The receiver has a simulated 2.8 dB and 4.3 dB receiver chain noise figure at 2.45 GHz and 5.25 GHz, respectively. For a 1.8 V power supply, the overall power consumption was only 66.1 mW.

Acoustic modeling provides useful synthetic data for evaluating seismic processing and imaging in complex geological settings. High order finite difference (FD) and finite elements (FE) was implemented and evaluated in homogeneous and heterogeneousmodel. The FD algorithm are extended to 2,5-D for variable density models. Seismic modeling of oil reservoirs targets somewhat similar to those occoring at Paleozoic Basins in the Amazon are presented. Long period multiples produced between the free-surface and the Cretaceous- Paleozoic interface, the low resolution of the seismic waves near the reservoir and the week reflections at the interface between the reservoir rocks and the cap rock are the main features of the synthetics which presents a challenge to seismic imaging.

Electromagnetic radiation produce by mobile phone and the relationship with the human's health is not a new issue nowadays. Since the used of mobile phone had increased rapidly over the past few years, people are becoming more concern with their health when dealing with the so-called electromagnetic radiation. This type of radiation would leads to heating of body tissue at specific rate called the thermal radiation. Thermal radiation depends on the frequency of the energy, the power density of the radio frequency field that strikes the body and the polarization of wave. This paper will discuss on the result collected from the thermal radiation generated by handheld mobile phone with frequency of 900 MHz towards adult human head. The analysis is conducted in a laboratory with average of 45 minutes talking hour with two different types of mobile phone, internal and external antenna. The results show an increased of heat especially at the place near the ear skull after 45 minutes of operation. When comparing both different types of mobile phone, mobile phone with external antenna produce more heat compared to mobile phone with internal antenna.

Realization of the BoseEinstein condensate can provide a way for creation of an inversion-free coherent light emitter with ultra-low threshold power. The currently considered solutions provide polaritonic emitters in a spectral range far below 1 µm limiting their application potential. Hereby, we present optical studies of InGaAs/ GaAs based quantum well in a cavity structure exhibiting polaritonic eigenmodes from 5 to 160 K at a record wavelength exceeding 1 µm. The obtained Rabi splitting of 7 meV was almost constant with temperature, and the resulting coupling constant is close to the calculated QW exciton binding energy. This indicates the very strong coupling conditions explaining the observation of polaritons at temperatures where the exciton dissociation is already expected, and allows predicting that room temperature polaritons could still be formed in this kind of a system.

Realization of the BoseEinstein condensate can provide a way for creation of an inversion-free coherent light emitter with ultra-low threshold power. The currently considered solutions provide polaritonic emitters in a spectral range far below 1 µm limiting their application potential. Hereby, we present optical studies of InGaAs/ GaAs based quantum well in a cavity structure exhibiting polaritonic eigenmodes from 5 to 160 K at a record wavelength exceeding 1 µm. The obtained Rabi splitting of 7 meV was almost constant with temperature, and the resulting coupling constant is close to the calculated QW exciton binding energy. This indicates the very strong coupling conditions explaining the observation of polaritons at temperatures where the exciton dissociation is already expected, and allows predicting that room temperature polaritons could still be formed in this kind of a system.

Realization of the BoseEinstein condensate can provide a way for creation of an inversion-free coherent light emitter with ultra-low threshold power. The currently considered solutions provide polaritonic emitters in a spectral range far below 1 µm limiting their application potential. Hereby, we present optical studies of InGaAs/ GaAs based quantum well in a cavity structure exhibiting polaritonic eigenmodes from 5 to 160 K at a record wavelength exceeding 1 µm. The obtained Rabi splitting of 7 meV was almost constant with temperature, and the resulting coupling constant is close to the calculated QW exciton binding energy. This indicates the very strong coupling conditions explaining the observation of polaritons at temperatures where the exciton dissociation is already expected, and allows predicting that room temperature polaritons could still be formed in this kind of a system.

Realization of the BoseEinstein condensate can provide a way for creation of an inversion-free coherent light emitter with ultra-low threshold power. The currently considered solutions provide polaritonic emitters in a spectral range far below 1 µm limiting their application potential. Hereby, we present optical studies of InGaAs/ GaAs based quantum well in a cavity structure exhibiting polaritonic eigenmodes from 5 to 160 K at a record wavelength exceeding 1 µm. The obtained Rabi splitting of 7 meV was almost constant with temperature, and the resulting coupling constant is close to the calculated QW exciton binding energy. This indicates the very strong coupling conditions explaining the observation of polaritons at temperatures where the exciton dissociation is already expected, and allows predicting that room temperature polaritons could still be formed in this kind of a system.

In this paper, a simple finite difference time domain (FDTD) approach is presented for the analysis and design of graphene based optical devices. Here, Maxwell's curl equations are expressed in normalized flux density. Then, the FDTD method is incorporated with that expression. As the flux density is considered, graphene conductivity which depends on frequency is easily incorporated with the method. The proposed method is used to investigate properties of single and multilayer graphene sheets. To probe the transmission, reflection and surface plasmon polariton (SPP) mode characteristics of graphene in terahertz and far infared frequency regime, numerical examples are demonstrated. Validation of the method has been demonostrated comparing with existing methods and results available in the literature. The accuracy, stability and benefits of proposed method are also presented.

A numerical illustration of a hybrid design and numerical analysis of graphene-coated fiber-optic surface plasmon resonance (SPR) biosensor for BRCA-1 and BRCA-2 genetic breast cancer detection is provided. Two specific mutations named 916delTT in BRCA-1 gene and 6174delT in BRCA-2 gene are being selected for detection of breast cancer numerically. This sensor is based on attenuated total reflection (ATR) method to detect individual point mutations in BRCA-1 and BRCA-2 genes. Based on the numerically obtained results, a momentous change is present in the SPR angle (minimum 35% more) and surface resonance frequency (SRF) (minimum 36% more) for probe DNA with various concentrations of target DNA corresponding to the mutation of the BRCA-1 and BRCA-2 genes. The variation of the SPR angle and SRF for mismatched DNA strands in BRCA-1 and BRCA-2 genes is quite negligible, whereas that for complementary DNA strands is considerable. This considerable change is essential for proper detection of genetic biomarkers (916delTT and 6174delT) for early breast cancer. To the best of our knowledge, this is the first demonstration of such an adept biosensor for detecting BRCA1 and BRCA2 genetic breast cancer. Here, we used graphene as bimolecular acknowledgement element for improving sensor performance. At the end of the article, the performance in terms of sensitivity is analyzed. Therefore, the proposed biosensor opens a window toward detection of early detection of BRCA-1 and BRCA-2 genetic breast cancers.

This paper reflects on the design and optimization of patch antennas. Two different methods were conducted. First, optimization was carried out over the whole antenna extension. Second, half antenna was optimized, and the final design was obtaining by reflection. The optimization process was conducted using genetic algorithm, return loss was obtained with full wave finite-differences time-domain, and the initial configuration (design) was obtained with line transmission and cavite method. All methods implemented in-house software. The antennas were designed to operate in Ku band with the center frequency at 16 GHz. Antenna with return greater than 22 dB and bandwidth between 2-5 GHz were obtained. The effectiveness of the proposed designs was confirmed through proper simulation results. Such optimization would aim to make a communication system more robust to electronic warfare attacks.

Self-assembled nanowires are posed to be viable alternatives to conventional planar structures, including the nitride epitaxy for optoelectronic, electronic and nano-energy applications. In many cases, current injection and extraction at the nanoscopic scale are essential for marked improvement at the macroscopic scale. In this investigation, we study the mechanism of nanoscale current injection and the origin of improvement of the flow of charged carriers at the group-III nitride semiconductor surface and metal-semiconductor interfaces. Conductive atomic force microscopy (c-AFM) and Kelvin probe force microscopy (KPFM) enable a rapid analysis of the electrical and morphological properties of single and ensemble nanostructures. The surface potential and current injection of AlGaN nanowirebased LEDs are spatially mapped before and after surface treatment with KOH solution. Treated-nanowires showed an improved current spreading and increased current injection by nearly 10×, reduced sub-turn-on voltage (as low as 5 V), and smaller series resistance. The reduced contact potential confirms the lower semiconductor/metal barrier, thus enabling larger carriers flow, and correlates with the 15% increase in injection efficiency in macroscopic LEDs. The improvement leads to the normalization of nanoscale electrical conducting properties of UV AlGaN-based nanowire-LEDs and lays the foundation for the realization of practical nanowire-based device applications.

We use a scattering-matrix based numerical method to model the optical properties and quasiguided eigenmodes in polaritonic crystal slab, i.e. a finite-thickness photonic crystal with polariton pole in dielectric susceptibility of some constituent materials. Particularly, we focus our attention on the dips in the transmission spectra, appearing due to excitation of quasi-guided (or leaky) modes of polaritonic crystal slab. We show that the polaritonic effect in the strong coupling regime of exciton-photon interaction significantly changes the energy and linewidth of these modes. Thus, it can be used to control such important parameters of photonic crystal slabs as stop-band widths and their overlap in different polarizations.

This letter presents numerical characteristics of recently developed the envelope FDTD based on the alternating direction implicit scheme (envelope ADI-FDTD). Through numerical simulations, it is shown that the envelope ADI-FDTD is unconditionally stable and we can get better dispersion accuracy than the traditional ADI-FDTD by analyzing the envelope of the signal. This fact gives the opportunity to extend the temporal step size to the Nyquist limit in certain cases. Numerical results show that the envelope ADI-FDTD can be used as an efficient electromagnetic analysis tool especially in the single frequency or band limited systems.

This study investigated the absorption efficiency of GaAs/In 0.2 Ga 0.8 As cylindrical coreeshell nanowire (NW) solar cells with a circular cross-section for normal incident light. Numerical results obtained through finite-difference timeedomain simulation showed that NW dimensions influenced the absorption efficiency of the solar cells. The band structure of the wires was also investigated.

This paper provides a simple hybrid design and numerical analysis of the graphene-coated fiber-optic surface plasmon resonance (SPR) biosensor for breast cancer gene-1 early onset (BRCA1) and breast cancer gene-2 early onset (BRCA2) genetic breast cancer detection. Two specific mutations named 916delTT and 6174delT in the BRCA1 and BRCA2 are selected for numerical detection of breast cancer. This sensor is based on the technique of the attenuated total reflection (ATR) method to detect deoxyribonucleic acid (DNA) hybridization along with individual point mutations in BRCA1 and BRCA2 genes. We have numerically shown that momentous changes present in the SPR angle (minimum: 135 % more) and surface resonance frequency (SRF) (minimum: 136 % more) for probe DNA with various concentrations of target DNA corresponding to a mutation of the BRCA1 and BRCA2 genes. The variation of the SPR angle and SRF for mismatched DNA strands is quite negligible, whereas that for complementary DNA strands is considerable, which is essential for proper detection of genetic biomarkers (916delTT and 6174delT) for early breast cancer. At last, the effect of electric field distribution in inserting graphene layer is analyzed incorporating the finite difference time domain (FDTD) technique by using Lumerical FDTD solution commercial software. To the best of our knowledge, this is the first demonstration of such a highly efficient biosensor for detecting BRCA1 and BRCA2 breast cancer. Therefore, the proposed biosensor opens a new window toward the detection of breast cancers.

This article illustrates a design and finite difference time domain (FDTD) method based on analysis of fiber optic surface plasmon resonance (SPR) biosensor for biomedical application especially for DNA-DNA hybridization. The fiber cladding at the middle portion is constructed with the proposed hybrid of gold (Au), graphene, and a sensing medium. This sensor can be recognized adsorption of DNA biomolecules onto sensing medium of PBS saline using attenuated total reflection (ATR) technique. The refractive index (RI) is varied owing to the adsorption of different concentration of biomolecules.  Result states that the sensitivity with a monolayer of graphene will be improved up to 40% than bare graphene layer. Owing to increased adsorption capability of DNA molecules on graphene, sensitivity increases compared to the conventional gold thin film SPR biosensor. Numerical analysis shows that the variation of the SPR angle for mismatched DNA strands is quite negligible, whereas that for co...